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1. 180 TCP IP User s Manual This is the form that is generated aoard ACME Thermostat Settings Name Value Description ieh Temp Maximum in temperature range 60 90 F Current Temp 72 Current temperature in F Low Temp 65 Minimum in temperature range 50 80 F Failure Action Page Action to take in case of air conditioning failure Humidity Target humidity between 0 0 and 1 0 Hap Chapter 4 HTTP Server 181 4 6 HTTP File Upload This section describes the HTTP file upload feature available starting with Dynamic C 8 50 The enhanced CGI capabilities of this version of Dynamic C allow files of unlimited size to be uploaded using a web interface It has always been possible to upload files using FTP however it is usually more convenient to use a browser based upload 4 6 1 What is a CGI Function and Why is It Useful The HTTP library provided with Dynamic C allows the association of C functions with web page URLs When the user via their web browser retrieves a specified resource the C function may be called from the HTTP server Such a function is called a Common Gateway Interface CGI func tion and it is responsible for generating a response to the user s request The advantage of using a CGI is that it can generate web page content on the fly and cause the browser to display or do anything that it is capable of In addition the CGI is
2. All error handling has been pared out of the above code For full details please refer to the sample program samples tcpip http upld fat c Chapter 4 HTTP Server 201 4 7 API Functions for HTTP Servers cgi continue int cgi continue HttpState state char localurl DESCRIPTION Called from a CGI function after processing any data submitted This function contin ues creating a response as if from a normal GET request to the specified local URL NOTE the CGI function must NOT have sent any data to the socket PARAMETERS state A pointer to the HTTP server state structure localurl The URL string which must be a URL defined in the server spec table otherwise the browser will see a not found message RETURN VALUE The return value from this function should be used as the return value from the CGI handler function that calls it LIBRARY HTTP LIB 202 TCP IP User s Manual cgi _redirectto void cgi redirectto HttpState state char url DESCRIPTION This utility function may be called in a CGI function to redirect the user to another page It sends a user to the URL stored in url You should immediately issue a return 0 after calling this function The CGI is considered finished when you call this and will be in an undefined state The http samples work correctly with cgi_redirectto because they use macro constants to define the URL parameter If you manipulate the url string please be a
3. Chapter 3 Server Utility Library 45 sauth adduser int sauth adduser char username char password word servermask DESCRIPTION This function adds a user to the user table It fills in the fields of the ServerAuth structure associated with this user Three of the field are specified by the parameters passed into the function Two other fields one for the user group mask and the other for the write access mask are given default values The default for the user group mask is the assigned index number 0 to SAUTH_MAXNAME 1 as a bit number that is 1 lt lt index This effectively creates each user in a unique single group Since this does not offer any real control over the assigned group mask it is recommended to use sauth_setusermask after this to assign the correct access masks The default for the write access mask is the user has no write access to any server To assign this permission call the function sauth_setwriteaccess with the user table index returned by sauth_adduser PARAMETERS username Name of the user a character string up to SAUTH_ MAXNAME characters password Password for the user another character string up to SAUTH_MAXNAME characters servermask Bitmask representing valid servers e g SERVER _HTTP SERVER_FTP RETURN VALUE 1 Failure 20 Success index into user table id passed to sauth_getusername LIBRARY ZSERVER LIB SEE ALSO sauth_authenticate sauth_getwriteacce
4. 0 seeeeeeeeeeeseeees sauth_setusermask seii 56 SSPCC_TCMOVE seeeeseeeceseeeeenteeeeenee 123 Sauth_SetwriteacceSs s 57 SSPEC_TEMOVETULIE eeeeereeeeeeees 124 SSPCC_ACCESS oo eee a t e 58 SSPEC_TEMOVEUSET 0eeseeseeeseeeeeees 125 sspec_addCGI Coesen ties ss teedoceleogt ao detlaees 59 sspec_resizerootfile u 126 3 SSPCC_TOSCOLC ecseeceeseeeeseeeeeseeeeeseees 127 TCP IP User s Manual iii SSPOC_IMAIL ooo eee eeeeeeeeeeeeees 128 http_getCond oo eee eee 217 SSPEC SAVE sis ai 129 http_getContentDisposition 218 Speci seek sicyegc cans ves heer a 130 http_getContentLength 0 219 sspec_setformepilog eee 131 http_getContentType 220 sspec_setformfunction 132 http_getcontext eee 221 sspec_setformprolog ee 133 http_getContext occas 222 sspec_setformtitle eee 134 http_getData oo eee eee 223 sspec_setfvcheck eesse 135 http_getDataLength 224 sspec_setfydesc oe eee eee 136 http_getField ee eee eee 225 sspec_setfventrytype s s s 137 http_getHTTPMethod 226 sspec_setfvfloatrange eee 138 http_getHTTP Version 227 sspec_Setfvlen sisenes 139 http_getRemainingLength 228 sspec_SetfvnamMe eee 140 http_getSocket eee eee 229 sspec_setfvoptlist cee eeeeeseeeeeee 141 http_getState eee 230 sspec_SetfVrange s s s 142 http_getTransferEncoding 231 sspec_setfvreado
5. word flags See below long mdtm Date time SEC_TIMER format long length Current file size long maxlength Max allowable file size ServerPermissions perm See below SSpecStat The flags field can be one of the following e SSPEC_ATTR_MDTM Modification date time SSPEC_ATTR_LENGTH Current length e SSPEC_ATTR_WRITE File is writable SSPEC_ATTR_EXEC File is executable SSPEC ATTR HIDDEN Hidden attribute bit SSPEC_ATTR_SYSTEM System attribute bit SSPEC_ATTR_ARCHIVE Archive attribute bit SSPEC_ATTR_DIR This is directory name SSPEC ATTR COMPRESSED Compressed format e SPEC _ATTR_MAXLENGTH Have maximum length SSPEC ATTR_SEEKABLE Randomly accessible SSPEC ATTR_ EXTENSIBLE File may be expanded at end Chapter 3 Server Utility Library 149 The ServerPermissions structure is defined as follows typedef struct word readgroups word writegroups word servermask char realm char method ServerPermissions Read or write permission is granted for readgroups or writegroups if current ServerAuth mask ie userid entry group mask matches in at least one bit position Bit is setin servermask field for each server that can access the resource Realm string of the resource only used by HTTP server but can be used for other purposes Authentication method s allowed combination of SERVER_AUTH bits RETURN VALUE 20 Success T
6. Chapter 4 HTTP Server 187 Content Disposition form data name submit This is form field data in this case the submit button itself upload 3VAL1QsFOUg2GsY3p 6n3YQ The boundary terminates the previous form field Since this is the last boundary it also has a trailing When writing the CGI you do not have to worry about parsing the headers and boundary separa tors This is already done by the HTTP server However you do need to be aware of the stream oriented nature of the incoming data The HTTP server separates out the parts and parses the headers As it does this it calls the defined CGI with the data for each section Action Codes Received by a CGI Function The CGI is called in a number of different contexts It determines the context by calling the http _getAction function The return value of http _getAction indicates the rea son that the CGI is being called by the HTTP server For a given upload the CGI is called with a typical sequence of action codes The first code is CGI_START for the start of a new part CGI_DATA for each chunk of data in that part then CGI_END for the end of the part Thus the typical sequence for a single part is CGI _ START CGI DATA CGI DATA CGI DATA CGI_END Finally at the end of all the parts the action code is set to CGI_EOF Most CGIs should also handle a special action code called CGI_ ABORT This code only occurs if the upload is terminated early by a net
7. int wrFree int read int write VSerialSpec For each serial port A B C and D there is a pre defined macro in VSERIAL LIB define VSERIAL PORTA id id serAopen serAclose NULL serArdUsed serAwrFree serAread serAwrite The parameter passed to VSERIAL PORTA is the unique gateway identifier mentioned earlier This value is chosen by the developer when entries are made to the array of type VSerialSpec also known as the spec table Dynamic C 9 21 includes support for serial ports E and F on all Rabbit 3000 based boards Chapter 10 Telnet 333 10 1 1 2 Configuration Macros VSERIAL DEBUG Turns on debug messages VSERIAL NUM GATEWAYS The number of telnet sessions must be defined and must match the number of entries in the spec table 10 1 2 API Functions Dynamic C 7 05 and later The following functions compose the latest telnet API A sample program demonstrating their use is available at Samples tcpip telnet vserial c vserial close int vserial close int id DESCRIPTION Closes the specified gateway This will not only terminate any network activity but will also close the serial port PARAMETERS id ID of the gateway to change as specified in the spec table RETURN VALUE 0 Success 1 Failure LIBRARY VSERIAL LIB vserial init int vserial init void DESCRIPTION Initializes the daemon and parses the spec table RETURN VALUE 0 Success 1
8. number body and size are the same as before to has the e mail address of who this e mail was sent to from has the e mail address of who sent this e mail subject has the subject line of the e mail These new fields should be used only the first time your call back is called with a new number field In subsequent calls these fields are not guaranteed to have accurate information See parse extra c in Section 9 5 for an example of this type of call back 326 TCP IP User s Manual 9 4 API Functions pops init int pop3 init int storemail DESCRIPTION This function must be called before any other POP3 function is called It will set the call back function where the incoming e mail will be passed to This probably should only be called once PARAMETERS storemail A function pointer to the call back function RETURN VALUE 0 Success 1 Failure LIBRARY POP3 LIB Chapter 9 POP3 Client 327 pop3 getmail int pop3 getmail char username char password long server DESCRIPTION This function will initiate receiving e mail a POP3 request to a remote e mail server IMPORTANT NOTE the buffers forusername and password must NOT change until pop3_tick returns something besides POP_ PENDING These values are not saved internally and depend on the buffers not changing PARAMETERS username The username of the account to access password The password of the account to access server The IP addres
9. RETURN VALUE Length of part data LIBRARY HTTP LIB SEE ALSO http _getAction Chapter 4 HTTP Server 219 http getContentType char http getContentType HttpState state DESCRIPTION Return the current content type of the data which is being provided by the client This is a MIME type string e g text html or image jpeg The CGI might need to look at this to determine the appropriate way to process the data Normal form fields will usually contain text plain however uploaded files may con tain any type of data It is only valid to call this when the action code is CGI_START CGI_DATA or CGI_END NOTE This is implemented as a macro PARAMETER state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE Null terminated string containing the MIME type name LIBRARY HTTP LIB SEE ALSO http _getAction 220 TCP IP User s Manual http getcontext ServerContext http getcontext int servno DESCRIPTION Return the ServerContext struct for the specified HTTP server instance NOTE This structure should not be modified by the application PARAMETER servno Server instance number 0 HTTP_MAXSERVERS 1 RETURN VALUE NULL invalid server instance Otherwise pointer to this server s ServerContext LIBRARY HTTP LIB Chapter 4 HTTP Server 221 http getContext ServerContext http getContext HttpState state DESCRIPTION Return the curr
10. 0 on success non zero if resulting string plus its null terminator could not fit in the provided buffer LIBRARY HTTP LIB SEE ALSO http handler Chapter 4 HTTP Server 239 http scanpost int http scanpost char tag char buffer char dest int maxlen DESCRIPTION This function allows you to scan a buffer with a POST response for the key value pairs This function is reentrant PARAMETERS tag Buffer holding the tag name buffer Buffer to read data from dest Buffer to store value to maxlen Size of destination buffer RETURN VALUE 0 Successful 0 Not successful LIBRARY HTTP LIB 240 TCP IP User s Manual http set anonymous int http set anonymous int uid DESCRIPTION Set the anonymous user ID This is the assumed user ID when no credentials are pro vided by the client browser A typical use of this function would be int anon anon sauth adduser anonymous SERVER_FTP SERVER_HTTP sauth_setusermask uid WORLD GROUP NULL http set anonymous uid ftp set anonymous uid if using FTP too which defines an anonymous login for the HTTP and optionally the FTP servers Since FTP also requires an anon user you can use the same user ID for both FTP and HTTP When a web browser initially requests a resource it may not pass any user credentials i e user name and password The HTTP server will assume that the user is anony mous and apply the ac
11. RETURN VALUE 1 Failure 20 Success return location of alias i e new index LIBRARY ZSERVER LIB SEE ALSO sspec_addform sspec_addfsfile sspec_addfunction sspec_addrootfile sspec_addvariable sspec_addxmemfile Chapter 3 Server Utility Library 71 sspec automount int sspec automount word which void fatstuff void fs2stuff void reserved DESCRIPTION This function automatically initializes and mounts the specified filesystem s for use by Zserver Mounting a filesystem creates an entry point to that filesystem for the server You must use the appropriate filesystem library for example FS2 LIB otherwise the filesystem will not be mountable If using the FAT library you must include one or more driver libraries such as sflash_ fat 1lib before use fat 1ib Only the default device from the first driver library will be initialized and used by this routine If you need to use any other devices you will need to initialize them individually and call the sspec_fatregister function SSPEC_MAX FATDRIVES will also need to be increased from its default value of one For the FAT library this routine calls fat_Init and mounts the first available FAT partition on that drive if any If the first available partition is the first partition on the drive then it will be mounted at mount point A If it is the second partition it will be mounted at B etc Up to four partitio
12. const char const fail _options Wama IL BAGET Email and page Nothing i These lines initialize the form variables temphi 80 tempnow 72 templo 65 Rumiane 39 strcpy fail Page The next line adds a form to the dynamic resource table The first parameter gives the name of the form When a browser requests the page myform htm1 the HTML form is generated and pre sented to the browser The second parameter gives the developer declared array in which form information will be saved The third parameter gives the number of entries in the my form array this number should match the one given in the my form declaration above The fourth parameter indicates that this form should only be accessible to the HTTP server and not the FTP server SERVER_HTTP should always be given for HTML forms The return value is the index of the newly created form in the dynamic resource table form sspec_addform myform html myform 5 SERVER HTTP Chapter 4 HTTP Server 177 This line sets the title of the form The first parameter is the form index the return value of sspec_addform and the second parameter is the form title This title will be displayed as the title of the HTML page and as a large heading in the HTML page sspec setformtitle form ACME Thermostat Settings The following line adds a variable to the resource table It must be added to this t
13. pop3_init storemsg set up call back printf Resolving name n address resolve POP HOST printf Calling pop3 getmail n pop3 getmail POP USER POP PASS address Request to server primei maceria D093 ieacle e o 5 while ret pop3 tick POP PENDING continue if ret POP_SUCCESS printf POP was successful n it Wee POP TIME printf POP timed out n it HSE s POP ERROR printf POP returned a general error n print All done n 330 TCP IP User s Manual 9 5 1 Sample Conversation The following is an example POP3 session from the specification in RFC1939 For more informa tion see http www rfc editor org rfc std std53 txt In the following example lines starting with S are from the server and lines starting with C are from the client n n ANANANNNHNHANAQANNANANNNNAA HANAN A lt wait for connection on TCP port 110 gt lt open connections OK POP3 server ready lt 1896 697170952 dbc mtview ca us gt APOP mrose c4c9334bac560ecc979e58001b3e22 b OK mrose s maildrop has 2 messages 320 octets STAT OK 2 320 LIST OK 2 messages 320 octets 1 120 2 200 RETR 1 OK 120 octets lt the POP3 server sends message 1 gt DELE 1 OK message 1 deleted RETR 2 OK 200 octets lt the POP3 server sends message 2 gt DELE 2 OK message 2 deleted QUIT OK dewey POP3 server signing off maildrop empty lt clos
14. since it writes to flash memory 11 7 1 Data Structure for Backup System The developer must define an array called console backup of ConsoleBackup struc tures typedef struct void data int len void postload void presave ConsoleBackup data This is a pointer to the data to be backed up len This is how many bytes of data need to be backed up postload This is a function pointer to a function that is called after configuration data is loaded in case the developer needs to do something with the newly loaded configuration data presave This is a function pointer that is called just before the configuration data is saved so that the devel oper can fill in the data structure to be saved The functions referenced by postload and presave should have the following prototype void my _preload void dataptr The dataptr parameter is the address of the configuration data the same as the data pointer in the ConsoleBackup structure 368 TCP IP User s Manual 11 7 2 Array Definition for Backup System const ConsoleBackup console backup CONSOLE BASIC BACKUP echo state baud rate port number CONSOLE _TCPIP BACKUP CONSOLE TCP MULTI BACKUP CONSOLE HTTP BACKUP CONSOLE _SMTP_BACKUP CONSOLE BACKUP LOGIN my_data my_data_len my preload my_presave CONSOLE BASIC BACKUP Causes backup of the echo state on or off baud rate and port number information CONSOLE TCPIP
15. some of the above fields may be set to non NULL in order to indicate to sspec_ automount that the application has already initialized some or all of the FAT Chapter 3 Server Utility Library 37 3 1 9 FormVar Structure An array of FormVar structures represent the variables in an HTML form The developer will declare an array of these structures with the size needed to hold all variables for a particular form The FormVar structure contains e Aserver_spec index that references the variable to be modified This is the location of the form variable in the server spec list e An integrity checking function pointer that ensures that the variables are set to valid values e High and low values for numerical types e Length for the string type and for the maximum length of the string representations of values e A Pointer to an array of values for when the value must be one of a specific and probably short list The developer can specify whether the variable is set through a text entry field or a pull down menu and if the variable should be considered read only This FormVar array is placed ina ServerSpec structure using the function sspec_addform ServerSpec entries that represent variables will be added to the FormVar array using sspec_addfv Properties for these FormVar entries for example the integrity checking properties can be set with various other functions Hence there is a level of indirection between the var
16. Normally this value will be zero when the action code is CGI_ EOF If the value is neg ative then the client might not have indicated the total data length or might not have set the right value NOTE This is implemented as a macro PARAMETER state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE Length of remaining data or negative if not known LIBRARY HTTP LIB SEE ALSO http _getAction 228 TCP IP User s Manual http getSocket tcp Socket http getSocket HttpState state DESCRIPTION Return the current HTTP server socket The socket may be written read however this is inadvisable since it may interfere with the server s use of it NOTE This is implemented as a macro PARAMETER state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE Pointer to the HTTP server s TCP socket structure LIBRARY HTTP LIB SEE ALSO http _getAction Chapter 4 HTTP Server 229 http getState int http getState HttpState state DESCRIPTION Return the current primary HTTP CGI state variable Use of this state variable is entirely up to the application however it is initialized by the HTTP server to zero before calling the CGI for the first time NOTE This is implemented as a macro PARAMETER state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE Value of primary state var
17. 1 Run Dynamic C 7 05 or later 2 Open a terminal emulator Windows HyperTerminal comes with Windows It does not work with binary files only ASCII Tera Term can handle both ASCII and binary It is available for free download at http hp vector co jp authors VA002416 teraterm html 3 Configure the terminal emulator as follows COM port 1 or 2 to which 3 wire serial cable is connected Baud Rate 57 600 bps Data Bits 8 Parity None Stop Bits 1 Flow Control None The terminal emulator should now accept Zconsole commands To avoid losing a lt LF gt at the beginning of a file when using the con_put command function select Setup gt Terminal from the Tera Term menu and set the Transmit option to CR LF This option might be located elsewhere if you are using a different terminal emulator Chapter 11 General Purpose Console 367 11 7 Backup System Zconsole can save configuration parameters to the file system or starting with Dynamic C 7 30 to the User block The configuration is then available across power cycles The backup process is done by con_backup Unlike the other Zconsole command functions con_backup does not take a parameter and it returns 0 if the backup was successful and 1 if it was not This function is called by several of the Zconsole command functions that change configuration param eters or that add or delete files or variables from the file system Caution is advised when calling con_backup
18. LIBRARY zconsole lib SEE ALSO con_backup_reserve 360 TCP IP User s Manual con backup reserve void con backup reserve void DESCRIPTION Reserves space for the configuration information in the file system For more information on the file system see the Dynamic C User s Manual LIBRARY zconsole lib SEE ALSO con_backup con_load_backup con_backup_bytes con chk timeout int con chk timeout unsigned long timeout DESCRIPTION Checks whether the given timeout value has passed RETURN VALUE 0 Timeout has not passed 0 Timeout has passed LIBRARY zconsole lib SEE ALSO con_set_timeout Chapter 11 General Purpose Console 361 con load backup int con load backup void DESCRIPTION Loads the configuration from the file system RETURN VALUE 0 Success 1 No configuration information found lt 0 Failure 1 error reading 1st set of information 2 error reading 2nd set of information and so on LIBRARY zconsole lib SEE ALSO con_backup con_backup_reserve con reset io void con reset io void DESCRIPTION Resets all I O methods by calling close and open on each of them LIBRARY zconsole lib 362 TCP IP User s Manual con set backup 1x void con _ set backup 1x FSLXnum backup1x DESCRIPTION Sets the logical extent LX that will be used to store the backup configuration data For more information on the file system see the Dynamic C
19. SEE ALSO sspec_ addfsfile sspec_addxmemfile sspec_addxmemvar sspec_addvariable sspec_addfunction sspec_addform sspec_aliasspec sspec_resizerootfile 64 TCP IP User s Manual sspec addrule int sspec addrule char pfx char realm word readgroups word writegroups word servermask word method MIMETypeMap mimetype DESCRIPTION Add a rule to the dynamic resource rule table Resource rules are used to associate ac cess information with resource names matching the specified prefix string The most specific that is the longest matching string is used Normally the rule table is consulted only for resource names that belong in a file sys tem FS2 or FAT You can also cause the rule table to be consulted for flash or RAM table entries if you leave the realm field as NULL in the entry If the realm field is not NULL then the rule table is not consulted for that entry If the realm field was NULL and there was no applicable entry in the rule table then the resource table per missions are used with NULL realm Do not attempt to use a very large number of rule table entries since the table must be searched exhaustively for each initial resource access There should be no need for a large number of entries provided that the resource name hierarchy is organized in a rea sonably efficient manner For example keep the resources for a particular user or realm in one directory and just add an entry for that directory
20. Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_getfventrytype Chapter 3 Server Utility Library 137 sspec setfvfloatrange int sspec setfvfloatrange int form int var float low float high DESCRIPTION Sets the range of a float variable PARAMETERS form spec index of the form var Index into the FormVar array of the variable low Minimum value of the variable high Maximum value of the variable RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_setfvrange sspec_setfvoptlist 138 TCP IP User s Manual sspec setfvlen int sspec setfvlen int form int var int len DESCRIPTION Sets the length of a form variable the maximum length of the string representation of the variable Note that for string variables 1en should not include the NULL termi nator PARAMETERS form spec index of the form var Index into the FormVar array of the variable len Length of the variable RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_getfvlen Chapter 3 Server Utility Library 139 sspec setfvname int sspec setfvname int form int var char name DESCRIPTION Sets the name of a variable that is displayed in the HTML form PARAMETERS form spec index of the form var Index into the FormVar array of the variable name Display name of the variable RETURN VALUE 0 Success 1 Failure LIBRARY
21. espe cially when they are doing something non trivial They are described in Section 4 6 HTTP File Upload Connection Abort Condition There are two fields in the HttpState structure that allow a CGI function to appropriately respond to a connection abort condition The user may set the field abort notify to a non zero value in a CGI function to request that the CGI function be called one more time with the cancel field set to one if a connection abort occurs Chapter 4 HTTP Server 169 4 5 3 Web Pages With HTML Forms With a web browser HTML forms enable users to input values With a CGI program those values can be sent back to the server and processed The FORM and INPUT tags are used to create forms in HTML The FORM tag specifies which elements constitute a single form and what CGI program to call when the form is submitted The FORM tag has an option called ACTION This option defines what CGI program is called when the form is submitted when the Submit button is pressed The FORM tag also has an option called METHOD that defines the method used to return the form information to the web server In Section 4 5 3 1 Sample HTML Page on page 171 the POST method is used which will be described later All of the HTML between the lt FORM gt and lt FORM gt tags define what is contained within a form Starting with Dynamic C 8 50 you can also use the enctype option inside the FORM tag This specifies a return enc
22. handle The following statement ensures that the handle is set back to 1 when we know it is closed http setCond s COND HANDLE 1 break case CGI_ EOF http switchcCGI s index html break case CGI ABORT handle http _getCond s COND HANDLE The following test is added so we don t try to close the handle if it is already closed if handle gt 0 sspec_close handle break return 0 Chapter 4 HTTP Server 193 What Happens if the Write Fails There is still one point to cover That is the sspec_write call is not guaranteed to swallow all of the data that it was told to write In fact sspec_write may completely fail for exam ple if the file system runs out of space First let s handle the case where sspec_write returns an error that is its return code is negative In this case we probably want to return an error indication to the client This can be done using the http switchCGI orcgi_redirectto functions A special page will need to be created for this purpose If this page is called upld_err htm1 then the following code could be used case CGI DATA handle http _getCond s COND HANDLE if sspec_write handle http getData s http getDataLength s lt 0 sspec_close handle http_switchCGI s upld_err htm1 break In the case of an error the handle is closed then the HTTP server presents the upld_err html page to the client
23. is how to access the file Currently this value is ignored If the anonymous user ID has been set then files it owns are globally accessible Returns whether the user can access it Owner permission or if access is because there is an anonymous user world permission NOTE This routine only determines accessibility of a name not whether the user can read and or write the contents PARAMETERS spec Handle to SSPEC file item options How to access O_RDONLY O_WRONLY or O_RDWR Currently this value is ignored uid The userID to access as RETURN VALUE 0 No access 1 uid only access 2 anonymous access user anonymous has been set SEE ALSO sspec_checkaccess Chapter 6 FTP Server 291 ftp init void ftp init FTPhandlers handlers DESCRIPTION Initializes the FTP server You can optionally specify a set of handlers for controlling what the server presents to the client This is done with function pointers in the FTPhandlers structure All FTP server instances share the same list of handlers The FTPhandlers structure is defined as typedef struct int open char name int options int uid int cwd int read int fd char buf long offset int len int write int fd char buf long offset int len close int fd long getfilesize int fd int int dirlist int item char line int listing int uid int cwd int cd int cwd char dir int uid int pwd
24. lt INPUT TYPE FILE NAME fs2 ext1 new htm SIZE 50 gt lt TD gt lt TR gt lt TABLE gt lt INPUT TYPE SUBMIT VALUE Upload gt lt FORM gt lt BODY gt lt HTML gt The first change is the substitution of the new server parsed tags with SSI tags The next change is the absence of any error checking Without RabbitWeb it is difficult to achieve this same function ality The CGI responsible for the processing the variable update would need to do it Which brings us to the next change in this HTML page the need for a second CGI function The ACTION attribute in the FORM tag identifies the new CGI by name update cgi The FORM tag also has a parameter for the encoding type When no encoding type is specified it defaults to URL encoded All new style CGIs must set the encoding type in the FORM tag to multipart form data as shown above The other change on this page is the NAME attribute in the first INPUT tag of the second form When uploading to an FS2 partition the mount point fs2 must be prepended to the filename The ext1 part is also prepended to the filename and refers to the second flash The default CGI function can now store an uploaded file in a valid FS2 partition Chapter 2 Web Enabling Your Application 29 30 TCP IP User s Manual 3 Server Utility Library This chapter is intended to be a detailed description of the resource manager Zserver and how it interfaces to other libraries s
25. oooenieeessessseseeserrereessressseee 40 SSPEC_MAXRULES recreen 40 SSPEC MAXSPEC sererai eneit 40 SSPEC_USERSPERRESOURCE 05 41 SSPEC_XMEMVARLEN cceeeeseeeeeeteeeeeee 41 stack free space for TFTP functions 0 0 00 304 Static resource table cccccceccsssseccecesseteceeeeees 43 Static WED pages oo ee ceesectecsteeteeeseeeeeeeeees 163 telNet se nnie ETTA 333 342 TELNET _ COOKED 0000 ecececceeeeceeeeeeeseeceeeeeeees 339 TETP client aoti cial hii ices 303 309 CHIME ZONE ooo cccceccceecececesesessesessseeeseeeseeess 162 TIMEZONE teree a r eE tE 159 1 H EREE E EE tel NEE AEA 161 U URL encoded data soceeeeeeeeeeseseseseserererererere 173 USEr table neen ts BAR aie eee eS 16 SETS LSE silica ceeds dovcecec todocdevtesiedlovieeedetvooveccdedveveeess 35 V VSERIAL_DEBUG uuu cic ce cececeeecececeeseseeseseeeeees 334 VSERIAL_NUM_GATEWAYS ooeec 334 Ww web browser control cceeeeeeeeeeeeeeseeeeeeeees 3 29 well known ports ETP servei ennnen a e nie 277 VET SEV ET a u e Gertat aa a iR k 158 POPA a E e 325 SMTP sefy kenn enn a E 311 Z Zconsole einen bi is serdeeceheaisseis 343 376 backup System ooo eee ee eeseeeeeeeeeeeeeeeeee 368 circular buffers oo ec enose 358 commands o eeeeeeeeccccscscscscscsecesecececeseseseseeseees 344 custom commands 0 0 0 ecccececeseseeeeeeeeeee 352 ETLOLMNESSALES ierre iie E counts oungsess 353 T O interfaces nenien rre 356 IMACTOS h a cn ie 370 372
26. overall write access using for example sauth_setwriteaccess uid SERVER_HTTP Be aware that rogue clients could easily change the resource name to something other than the one that was intended in the original form This is why resource protection is important Having done these three things the HTTP server is now set up to automatically place uploaded files in the filesystem Note that this CGI is limited to placing files into fixed resource locations as specified by the field name of the INPUT element If you need more sophisticated control you may wish to write your own CGI function using the code of this one as a starting point This CGI also presents a default status web page back to the client This page indicates whether the upload was successful the number of bytes uploaded and a link to test out the new file assuming it is something the browser will understand such as an HTML document or GIF image You can use this function as a starting point for generating your own content PARAMETERS state HTTP state pointer provided by HTTP server to all CGIs newURL The resource name to present to the client This may be another CGI or any other type of resource that could be presented to the client in response to an HTTP GET or POST request The resource must exist in the flash or ram spec table or in a filesystem RETURN VALUE See documentation for writing a data handler CGI LIBRARY HTTP LIB SEE ALSO http
27. the HTTP or SMTP related commands are included in the console commands array above then the backup information must be included in this array The entries below are macros that expand to the appropriate entry for each set of functionality Users can also add their own information to be backed up here by adding more ConsoleBackup structures const ConsoleBackup console backup CONSOLE BASIC BACKUP CONSOLE TCP BACKUP CONSOLE HTTP BACKUP CONSOLE SMTP BACKUP Jen Chapter 11 General Purpose Console 375 The following code defines the MIME types that the web server will handle const HttpType http types ahem text html shtml _ handler ssi hrm rex mem NO html gif image gif NULL Jpg Timage Jpegt NULUY jpeg image jpeg NULL UP pet Veeze plarm p Nou ANON oO T aan We The function for the custom command is defined here and the main program finishes up the pro gram To see the complete sample look in Samples zconsole tcpipconsole c This is a custom command Custom commands always take a ConsoleState as an argument a pointer to the state structure for the given I O stream and return an int The return value should be 0 when the command wishes to be called again on the next console tick 1 when the command has successfully finished processing or 1 when the command has finished due to an error OF OF int hello world ConsoleState state state g
28. tion and no limitations on the form layout See the document titled RabbitWeb To Web Enable Embedded Applications for more information on this enhanced HTTP server Zserver supports the concept of a virtual file system This is modeled on the Unix directory struc ture 3 1 Data Structures for Zserver lib There are several data structures in this library that servers with Zserver functionality must use and may need to be manipulated or initialized by the application program e MIMETypeMap e ServerSpec e ServerAuth e ServerPermissions e RuleEntry Use of the following structures is considered advanced e ServerContext e SSpecStat e sspec fatinfo Chapter 3 Server Utility Library 31 The following structures are documented for historical reasons e FormVar e SSpecFileHandle 3 1 1 MIMETypeMap Structure This structure organized into a table associates a file extension with a MIME type Multipurpose Internet Mail Extension and a function that handles the MIME type Users can override HTTP _MAXNAME defaults to 20 characters in their source file If the function pointer given is NULL then the default handler which sends the content verbatim is used typedef struct char extension 10 char type HTTP _MAXNAME int fptr HttpState MIMETypeMap For example to create an HTTP server that can serve files with html or gif extensions the follow ing declaration is required in th
29. value when RabbitWeb is not available to do it Note that they are word values each with a unique bit position set Next the first entry in the MIME table was changed Recall that the entry and requests with out an extension are dealt with by the handler in the first entry of the MIME table In this example if a browser points to the Rabbit board s IP address the page is processed by shtml_handler a handler that will understand the SSI tags that we are about to add to the HTML file The ximport statement did not technically need to change The extension used for the file was changed from zhtm1 to shtml These file extensions are only a convention The important thing is that the HTML file is touched by the correct handler function As a matter of fact in this example our HTML page is not recognized by the server as ending with either zhtml or shtml but by htm1 The name known to the server is determined by the name parameter of the file s resource table entry index html The next change is a new entry in the static resource table This reflects the shift in how the vari able io _state becomes known to the HTTP server Previously it was done using the web statement of RabbitWeb A second new entry in the resource table is for a CGI function that will handle the processing when io state is updated When using RabbitWeb this same form submission did not require a CGI The enhanced HTTP server took care of a
30. 8 50 it was sometimes necessary for CGI functions to access directly the fields of this structure New programs should not directly access the fields since it reduces the chance of upward compatibility There is a new suite of macros see http _getAction and related macros that should be used instead Where applicable the equivalent macro is documented with the field Some fields do not have an equivalent macro such as the cookie field for now use read only access to such fields A pointer to Ht tpState is the first and only parameter to all CGI functions Most of the time this pointer should be passed on to other HTTP library functions Note that the HttpState structure is only valid within a CGI function that has been called from the HTTP server Outside of this for example in your main function none of the fields are guaranteed to be meaningful or consistent 4 1 1 1 HttpState Fields The fields discussed here are available for developers to use in their CGI functions s This is the socket associated with the given HTTP server A devel oper can use this in a CGI function to output dynamic data although there are better safer ways of doing this see the section on Writing a CGI Function Any of the TCP functions can be used however you should not use any functions that may wait for long periods or may change the state or mode of the socket since the HTTP server depends on it being a normal ASCII mode TCP socket
31. ASCII mode usage put lt filename gt The file is then sent terminating with a D or Z 0x04 or 0x1A e BINARY mode usage put lt filename gt lt size in bytes gt The file is then sent and must be exactly the specified number of bytes in length Note that ASCII mode is only useful for text files since the console will ignore non displayable characters In binary mode the put command will time out after CON_ TIMEOUT seconds of inac tivity 60 by default con_putv This function updates the value of a variable A command that uses this function takes two param eters the name of the variable and the new value for the variable con_reset_files This function removes all web files con_reset_variables This function removes all web variables con_set_dhcp This function turns DHCP configuration for an interface on or off Currently this command only works with the default interface After DHCP has been turned on ZConsole will undertake reacquiring the lease should it be dropped For example a lease might be dropped if the DHCP server is unavailable for an extended period of time con_set_gateway This function changes the gateway of the board A command that uses this function takes one parameter the new gateway in dotted quad notation e g 192 168 1 1 con_set_icmp_config This function configures an interface to use directed ICMP echo request ping packets for config uration A command that uses th
32. Backup System 368 Array Definition for Backup System 369 11 8 Zoonsole Macros s es 370 11 9 Sample Program eee eee 373 Notice to Users 377 dek isn ns wee Beh iets 379 vi TCP IP User s Manual 1 Introduction The TCP IP User s Manual is intended for embedded system designers and support professionals who are using a Rabbit based controller board Most of the information contained here is meant for use with Ethernet enabled boards but using only serial communication is also an option Knowledge of networks and TCP IP Transmission Control Protocol Internet Protocol is assumed For an overview of these two topics a separate manual is provided An Introduction to TCP IP A basic understanding of HTML HyperText Markup Language is also assumed For information on this subject there are numerous sources on the Web and in any major book store The Dynamic C implementation of TCP IP comprises several libraries The main library is DCRTCP LIB As of Dynamic C 7 05 this library is a light wrapper around DNS LIB IP LIB NET LIB TCP LIB and UDP LIB These libraries implement DNS Domain Name Server IP TCP and UDP User Datagram Protocol This along with the libraries ARP LIB ICMP LIB IGMP LIB and PPP LIB are the transport and network layers of the TCP IP pro tocol stack The Dynamic C libraries e BOOTP LIB e FTP SERVER LIB e FTP CLIENT LIB e HTTP LIB e POP3 LIB e SMNP LIB e SMTP LIB e TFTP LIB
33. Dynamic C Function Reference Manual All of these documents are available on our website at www zworld com 44 TCP IP User s Manual 3 4 HTML Forms This facility is oriented towards the HTTP server however it is Zserver that actually handles the form data as a special resource type in the dynamic resource table only Defining FORM_ERROR_BUF is required to use the HTML form functionality in ZSERVER LIB The value assigned to this macro is the number of bytes to reserve in root memory for the buffer used for form processing This buffer must be large enough to hold the name and value for each variable plus four bytes for each variable An array of type FormVar must be declared to hold information about the form variables Be sure to allocate enough entries in the array to hold all of the variables that will go in the form If more forms are needed then more of these arrays can be allocated Please see Section 4 5 4 on page 176 for an example program Starting with Dynamic C 8 50 a more flexible way of supporting form generation is available with the Dynamic C RabbitWeb Module For more information on this enhanced HTTP server see the document RabbitWeb To Web Enable Embedded Applications available at www zworld com products dc DC8 docs shtml 3 5 API Functions The resource manager API functions are described in this section These functions give servers a consistent interface to files variables and client information
34. END This sequence of macros is used to define static rules See the documentation with the sspec_addrule function for more information You must define SSPEC_FLASHRULES to use these macros Chapter 3 Server Utility Library 41 3 2 5 2 Static MIME Type Table This table maps file extensions and MIME types You only need such a table if using a server that requires MIME types Currently only the HTTP server needs this SSPEC MIMETABLE START SSPEC MIME extension type SSPEC MIME FUNC extension type function SSPEC MIMETABLE END This sequence sets up the MIME type mapping table Currently only a static MIME ta ble is supported Though you cannot dynamically add new MIME types to this table it is possible to allocate new MIMETypeMap structures in RAM and assign them to spe cific resources using sspec_addrule or sspec_setpermissions Such entries will not be accessed using the default resource name extension method 42 TCP IP User s Manual 3 2 5 3 Static Resource Table The static resource table associates the names of web server resources files functions and vari ables to references to memory objects HTTP NO FLASHSPEC Define if there is to be NO static resource table that is all resources are in the dynamic RAM table or in the filesystem s If you define this then there is no point in using the SSPEC_RESOURCE_ series of macros below SSPEC RESOURCETABLE START SSPEC RESOURCE ROOTFILE name addr le
35. It is recommended that you use the http getSocket macro instead of directly accessing this field substate subsubstate Intended for holding the current state of a state machine for a CGI function That is if a CGI function relinquishes control back to the HTTP server then the values in these variables will be preserved for the next http handler call in which the CGI function will be called again These variables are initialized to 0 before the CGI function is called for the first time Hence the first state of a state machine using substate should be 0 It is recommended that you use the macros http_getState andhttp_setState to manipulate the substate field in stead of directly accessing it subsubstate is not accessible via these macros but there are better alternatives 154 TCP IP User s Manual timeout main timeout buffer P method url version This value can be used by the CGI function to implement an internal time out This value holds the timeout that is used by the web server The web server checks against this timeout on every call of http handler When the web server changes states it resets main timeout When it has stayed in one state for too long it cancels the current processing for the server and goes back to the ini tial state Hence a CGI function may want to reset this timeout if it needs more processing time but care should be taken to make sure that the server is not l
36. LIB 338 TCP IP User s Manual 10 2 Telnet pre Dynamic C 7 05 The API available for telnet changed with Dynamic C version 7 05 This is the old API 10 2 1 Configuration Macros SERIAL PORT SPEED The baud rate of the serial port Defaults to 115 200 bps TELNET COOKED define this to have telnet control codes stripped out of the data stream This is useful if you are actually telneting to the device from another box It should not be defined if you are using two devices as a transparent bridge over the Ethernet 10 2 2 API Functions telnet init int telnet init int which longword addy int port DESCRIPTION Initializes the connection This function must not be called by an application program starting with Dynamic C 7 05 PARAMETERS which Is one of the following TELNET _LISTEN Listens on a port for incoming connections TELNET _RECONNECT Connects to a remote host and recon nects if the connection dies TELNET _CONNECT Connects to a remote host and terminates if the connection dies addy IP address of the remote host or 0 if we are listening port Port to bind to if we are listening or the port of the remote host to connect to RETURN VALUE 0 Success 1 Failure LIBRARY VSERIAL LIB Chapter 10 Telnet 339 telnet tick int telnet tick void DESCRIPTION Must be called periodically to run the daemon RETURN VALUE 0 Success call it again 1 Failure TELNET CONNECT died or a fat
37. Physical address of buffer word buf len Length of buffer word buf _ used Amount Tx or Rx from to buffer word next blk Next expected block or next to Tx word my tid UDP port number used by this host udp Socket sock UDP socket to use longword rem_ip IP address of remote host longword timeout ms timer value for next timeout char retry retransmit retry counter char flags miscellaneous flags see below Following fields not used after initial request has been acknowledged char mode Translation mode see below char file 129 File name on remote host TFTP server NULL terminated This field will be overwritten with a NULL term error message from the server if an error occurs ba The following macros are valid for tftp_state gt mode define TFTP MODE NETASCII 0 ASCI text define TFTP_MODE OCTET 1 8 bit binary define TFTP MODE MAIL 2 Mail remote file name is email address e g user host blob org 7 3 API Functions Any of the following functions will require approximately 600 800 bytes of free stack The data buffer for the file to put or to get is always allocated in xram see xalloc TFTP Session A session can be either a single download get or upload put The functions ending with x are versions that use a data structure allocated in extended memory for applications that are con strained in their use of root data memory 304 TCP IP U
38. Return formatted directory listing line To use this function call it with item 0 the first time then keep calling it with i tem lt previous return value gt until it returns neg ative This allows you to iterate through all entries in a directory The ServerContext structure contains the current user ID server and the name of the directory to list Note For a given directory you should call this function with item 0 followed by more calls until it returns 1 If you want to terminate the directory listing without iter ating through every entry pass the SSPEC_LIST_END option flag see below This allows Zserver to release any temporary resources acquired for the purpose of iterating through the directory This is especially important for FAT filesystem listings After this function returns negative you must start the next directory listing from the top that is item 0 If you do not complete the listing then your application may not be able to perform fur ther listings owing to internal resource leakage This is similar to the need to close file resources that are opened See the second example below Pass the same ServerContext structure for the entire directory list sequence since Zserver keeps track of state information in this structure EXAMPLE To iterate through all resources under A ServerContext ctx int item char buf 80 word opts word n etx rootdir ctx server SERVER FTP ctx u
39. TCP IP servers object list LIBRARY ZSERVER LIB SEE ALSO sspec_addform sspec_addfsfile sspec_addrootfile sspec_addvariable sspec_addxmemvar sspec_addxmemfile sspec_aliasspec 62 TCP IP User s Manual sspec addfv int sspec addfv int form int var DESCRIPTION Adds a variable to a form PARAMETERS form spec index of the form previously returned by sspec_addform var spec index of the variable to add which must have been previous ly created using sspec_addvariable RETURN VALUE 1 Failure 20 Success next available index into the FormVar array LIBRARY ZSERVER LIB SEE ALSO sspec_addform Chapter 3 Server Utility Library 63 sspec addrootfile int sspec addrootfile char name char fileloc int len word servermask DESCRIPTION Adds a file that is located in root memory to the dynamic resource table Make sure that SSPEC_MAXSPEC is large enough to hold this new entry PARAMETERS name Name of the new file This must be unique but this function does not check The name should not conflict with the virtual filesystem hierarchy That is it should not start with s2 A B etc fileloc Pointer to the beginning of the file len Length of the file in bytes servermask Bitmask representing servers for which this entry will be valid e g SERVER HTTP SERVER_FTP RETURN VALUE 1 Failure 20 Success file index into the resource list LIBRARY ZSERVER LIB
40. The current CGI is abandoned including any pending data that is still incoming This is why the handle is explicitly closed since upld_err html probably doesn t know any thing about it Naturally upld_err html is a web page that tells the user that something went wrong In practice this would usually be an SSI rather than a static web page since you would probably want to give the user different feedback depending on the exact type of error The final consideration is what to do if sspec_write can only write some or perhaps none of the data it was given The normal course of action is to just retry later with the data that was not written You could just sit in a loop in the CGI function waiting for the data to be written This may be satisfactory in some cases but often this will unnecessarily reduce system performance since nothing else will get a chance to run except interrupts It is preferable to return to the HTTP server which in turn can return to the application before coming back into the CGI CGI Return Codes This is where the CGI return code becomes important Up to now the return code has always been zero which means continue as usual However some of the APIs such as http _abortCGI override this There are several other legitimate values for the return code e CGI_MORE Call back again when free space in transmit buffer e CGI_DONE CGI has finished writing data to the client e CGI_SEND Send the data
41. Time Run Time Main Application CGI Initialization Initialization Loop Specifics I Q_ _ Functions web Variables a Metadata Resources Requests MIMEJ Context 1 Table N Zserver gt Rule Resource Manager Table Static Dynamic i Resource Resource i Table Table ALETE AN Storage Serial Flash Figure 2 4 Minimal components of a web enabled application with dynamic content and access control The main difference between this and the previous diagram is that the Rule Table and User Table blocks have been activated Chapter 2 Web Enabling Your Application 17 The sample program is now expanded to add access control As before the changes are in bold face define TCPCONFIG 1 define USE RABBITWEB 1 define USE HTTP BASIC AUTHENTICATION 1 use dcrtcp lib use http 1lib web groups monitor group admin group ximport my _app zhtml my_app zhtml SSPEC MIMETABLE START SSPEC MIME FUNC html text html zhtml_handler SSPEC MIMETABLE END SSPEC RESOURCETABLE START SSPEC RESOURCE XMEMFILE index html my_app zhtm1 SSPEC RESOURCETABLE END int io state web io state auth basic groups monitor group ro admin group void my_io_polling void void main sspec addrule index html Pet admin group monitor group 0 SERVER HTTP SERVER AUTH BASIC NULL sauth setusermask sauth_adduser admin dog SERVER ANY admin group NULL sauth setusermask saut
42. _getAction http_skipCGI http _switchCGI http finishcCGI http write 210 TCP IP User s Manual http delfile int http delfile char name DESCRIPTION Deletes a file from the RAM spec table PARAMETERS name Name of the file as passed to http_addfile RETURN VALUE 0 Success 1 Failure not found LIBRARY HTTP LIB SEE ALSO http_addfile Chapter 4 HTTP Server 211 http finderrbuf char http finderrbuf char name DESCRIPTION Finds the occurrence of the given variable in the HTML form error buffer and returns its location PARAMETERS name Name of the variable RETURN VALUE NULL Failure I NULL Success location of the variable in the error buffer LIBRARY HTTP LIB 212 TCP IP User s Manual http findname int http findname char name DESCRIPTION Finds a spec entry searching first in RAM then in flash This function is deprecated as of Dynamic C 8 50 Use sspec_ findname PARAMETERS name Name in text of the spec to find RETURN VALUE The spec entry LIBRARY HTTP LIB Chapter 4 HTTP Server 213 http finishcGI int http finishCGI HttpState state DESCRIPTION Indicate to the HTTP server that this CGI has finished processing data from this multi part data stream The server reads and discards data to the end of the entire stream in cluding epilog The next call to the CGI function will have an action code of CGI_EOF or poss
43. a raw dump of the incoming e mail This includes all of the header information that is sent with the e mail which while some times useful may be more information than is needed The second method provides a parsed ver sion of the e mail with the sender recipient subject line and body text separated out In both methods each line of e mail has CRLF stripped from it and 0 appended to it 9 1 Configuration The POP3 client can be configured through the following macros POP BUFFER SIZE This will set the buffer size for POP_PARSE EXTRA in bytes These are the buffers that hold the sender recipient and subject of the e mail POP_BUFFER_SIZE defaults to 64 bytes POP DEBUG This will turn on debug information It will show the actual conversation between the de vice and the remote mail server as well as other useful information POP NODELETE This will stop the POP3 library from removing messages from the remote server as they are read By default the messages are deleted to save storage space on the remote mail server POP PARSE EXTRA This will enable the second mode creating a parsed version of the e mail as mentioned above The POP3 library parses the incoming mail more fully to provide the Sender Re cipient Subject and Body fields as separate items to the call back function Chapter 9 POP3 Client 325 9 2 Steps to Receive E mail l pop3_ init is called to provide the POP3 library with a call back fun
44. able to read data that was sent by the browser Previous to this release of Dynamic C the CGI was limited to handling relatively small amounts of data sent from the browser This is satisfactory for processing simple forms but does not allow large data sets to be uploaded This release of Dynamic C supports upload of one or more files from the browser The files can be of unlimited size In conjunction with the latest Zserver resource manager enhancements available in Dynamic C 8 50 the uploaded files may be stored in the FS2 or FAT file systems or even processed dynamically The new CGI file upload facility enables a range of convenient firmware features Possibilities include e Remote firmware updates e Web page content updates i e publishing e Executable interpreter scripts Remote hardware updates if using an FPGA or other configurable logic device e Firmware configuration NOTE Throughout this document the FAT file system is the destination for the uploaded file The FAT uses onboard serial flash and is available as a module which may be purchased separately See www zworld com 182 TCP IP User s Manual 4 6 2 How Do I Use the New CGI Facility There are a number of steps some of which will be familiar to users of CGIs in previous releases They are listed here and described in more detail in the following pages The steps if coding from scratch are 1 use dcrtcp lib and specify networ
45. and any given user can belong to one or more of these 16 groups There are two additional masks in each user table entry The first is a write access mask that indicates which server s allow the user to write modify its resources The second mask indicates the server s that can recognize the user The Rule Table The rule table is a list of information associated with each resource name generally called per missions Each resource has the following information e The realm string that may be used by certain servers including HTTP e The group mask of the user groups that are allowed read only access e The group mask of the user groups that are allowed modify write access e The server s that are allowed any access to this resource e The authentication method that is recommended e The MIME type of the resource Resources in the static and dynamic resource tables may be set up to have their own specific per missions independent of the rule table itself Resources in a filesystem may be very numerous hence a simple one to one table would waste a lot of storage To solve this problem the rule table uses a name prefix matching algorithm Using this technique entire directories of resources need only have one rule table entry provided that all resources therein use the same permissions 16 TCP IP User s Manual The following diagram shows the application components when access control is added Application Compile
46. applications to determine if there is data waiting on the socket associated with a particular HTTP server PARAMETERS state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE 1 no bytes waiting to be read 0 in ASCII mode a blank line is waiting to be read or for UDP an empty datagram is waiting to be read gt 0 number of bytes waiting to be read LIBRARY HTTP LIB Chapter 4 HTTP Server 249 http sock fastread int http sock fastread HttpState state byte dp int len DESCRIPTION HTTP wrapper function for sock_fastread that is for non blocking reads root This function can be used to read data from a socket associated with a particular HTTP server This function is intended for use in CGI applications PARAMETERS state HTTP state pointer as provided in the first parameter to the CGI function dp Pointer to return buffer len Maximum size of return buffer RETURN VALUE gt 0 the number of bytes read 1 error LIBRARY HTTP LIB 250 TCP IP User s Manual http sock fastwrite int http sock fastwrite HttpState state byte dp int len DESCRIPTION HTTP wrapper function for sock_ fastwrite that is for non blocking writes This function can be used to write data from a root buffer to a socket associated with a particular HTTP server This function is intended for use in CGI applications PARAMETERS state HTTP state pointer as provided in the fir
47. can be HITP_VER_09 HTTP _VER_10 orHTTP_VER_11 for 0 9 1 0 or 1 1 requests respectively Use http _getHTTPVersion for new code Chapter 4 HTTP Server 155 content typel This should be treated as read only This buffer holds the value from the Content Type header sent by the client Use http _getContentType for new code content length This should be treated as read only This variable holds the length of the content sent by the client It matches the value of the Con tent Length header sent by the client Use http _getContentLength for new code has form This should be treated as read only If the value is 1 there is a GET style form after the 0 byte in url abort notify Set to 0 in user defined formprolog function to indicate that the formepilog function needs to be called on an abort condition If the epilog function is reached normally this field must be set to zero This prevents the formepilog function from be ing called one more time on a connection abort cancel This should be treated as read only It is intended for when the user defined functions which may be called before and after an HTML form is submitted are used for locking resources If the formprolog function was called and then the connection is aborted before the formepilog function can be called cancel is set to 1 and the formepilog function is called exactly once If the epilog function was already called but returned zer
48. example We have introduced the concept of dynamic content which is required for embedded type applications One thing that has been glossed over is how and even whether the variable can be updated from the browser rather than just within the application Yes all web variables may be updated via the browser This requires use of HTML forms which is a subject covered in the detailed documenta tion for RabbitWeb and in the HTTP library chapter We will not go over this again here however the possibility of remote updating introduces us to the topic of the next section access control Chapter 2 Web Enabling Your Application 15 2 6 Adding Access Controls If your application allows updating of the controller state via remote access and the network con nection allows access from locations that are not always under control then it is important to add some access controls or security The most common way of doing this is to define a set of users plus a method of authenticating those users and attaching a set of permissions to each resource The Dynamic C libraries allow you to do this fairly easily via two tables The relevant tables are The User Table The user table contains a list of user IDs short strings and authentication information currently a password string Each user table entry also contains a group mask The group mask indicates the user groups to which this user belongs Up to 16 groups can be defined
49. head gt This HTTP Upload Form gets displayed at the top of the browser window You can change this to whatever is appropriate for describing the overall purpose of this page lt body gt Introduce the main content of this page lt FORM ACTION upload cgi METHOD POST enctype multipart form data gt Start a form definition The parameters are action upload cgi this refers to the CGI function that will process the results of the form submis sion This is a URL name which is mapped to a C function on the server method post this is required since a post type request must be sent to the server enctype multipart form data this is also required and is the part that is different from the old Style of processing The old style did not specify an encoding type thus the default of URL encoded was used lt TABLE BORDER 0 CELLSPACING 2 CELLPADDING 1 gt For neatness of screen layout we put everything in an HTML table The following lt TR gt lt TR gt sections delimit each row of the table and the data for each cell is delimited by lt TD gt lt TD gt lt TR gt lt TD WIDTH 130 ALIGN RIGHT gt lt B gt Name lt B gt lt TD gt lt TD WIDTH 500 gt lt INPUT TYPE TEXT NAME user name SIZE 50 gt lt TD gt This is the first input field It is not a file to upload but it is information that the server may never theless be interested in This shows that not every form field needs to be a fil
50. http date str char http date str char buf DESCRIPTION Print the date time zone adjusted into the given buffer This assumes there is room PARAMETERS buf The buffer to write the date into This requires at least 30 bytes in the destination buffer RETURN VALUE A pointer to the string LIBRARY HTTP LIB SEE ALSO http_handler 208 TCP IP User s Manual http defaultCGI int http defaultCGI HttpState state DESCRIPTION This function should not be called directly by the application It is intended to be used as a new style CGI for handling file uploads See samples tcpip http upld_fat c for an example of using this function This CGI function accepts POST requests from the client browser which may contain one or more files that are being uploaded It looks at the field name of the form data in the request If the field name starts with it is assumed to be the name of a resource which is to be created if it does not already exist and overwritten with the uploaded file contents There are three steps required to use this CGI 1 Define a CGI resource in the flash or ram spec table If using flashspec for example there would be an entry like SSPEC RESOURCETABLE START SSPEC RESOURCE XMEMFILE index html index html SSPEC RESOURCE CGI upload cgi http defaultcCGI SSPEC RESOURCETABLE END There may be other resources but at least two are normally required One resource is a web
51. http handler void DESCRIPTION This is the basic control function for the HTTP server a tick function to run the HTTP daemon It must be called periodically for the daemon to work It parses the requests and passes control to the other handlers eitherhtml_ handler shtml_ handler or to the developer defined CGI handler based on the request s extension LIBRARY HTTP LIB SEE ALSO http init 234 TCP IP User s Manual http idle int http idle void DESCRIPTION Query to see if any HTTP servers are active RETURN VALUE 0 at least one HTTP server is active 1 all HTTP servers are idle LIBRARY HTTP LIB SEE ALSO http_handler Chapter 4 HTTP Server 235 http init int http init void DESCRIPTION Initializes the HTTP daemon This must be called after sock_init and before calling http handler ina loop This sets the root directory to and sets the default file name to index html You can change these defaults by calling http set path after this function You can override these defaults at compile time by defining the macros define HTTP HOMEDIR define HTTP DFLTFILE index html to be something other than these defaults If you do this then there is no need to invoke the http_set_path function RETURN VALUE 0 Success LIBRARY HTTP LIB SEE ALSO http_handler http shutdown http status http _set_path 236 TCP IP User s Manual http nextfverr void
52. http nextfverr char start char name char value int error char next DESCRIPTION Gets the information for the next variable in the HTML form error buffer If any of the last four parameters in the function call are NULL then those parameters will not have a value returned This is useful if you are only interested in certain variable information PARAMETERS start Pointer to the variable in the buffer for which we want to get infor mation name Return location for the name of the variable value Return location for the value of the variable error Return location for whether or not the variable is in error 0 if it is not 1 if it is next Return location for a pointer to the variable after this one RETURN VALUE None although information is returned in the last four parameters LIBRARY HTTP LIB Chapter 4 HTTP Server 237 http parseform int http parseform int form HttpState state DESCRIPTION Parses the returned form information It expects a POST submission This function is useful for a developer who only wants the parsing functionality and wishes to generate forms herself Note that the developer must still build the array of FormVars and use the server_ spec table This function will not however automatically display the form when used by itself If all variables satisfy all integrity checks then the variables values are updated If any variables fail then none of the values are updated an
53. http_SetcOOKie 0 0 eee eeeeeeseeceneeceeeeeneeeeees 244 SSpec_getfVdese oo eee eee eeeeeeeeeeeeeees 92 Data Conversion sspec_getfventrytyPe 0 eee eee eeeeeeeeee 93 http_contentencode eee eee eeeere eee 207 sspec_getfVlen oo eee oeeie sasi e 94 Http sdatecStr cove csecceavee sien sethsceecaeeesteeieas 208 sspec_getfvname eeeeeeeceeseeeereeseeceneeeeees 95 http_urldecode 0 0 eee eee eseeeeeceteeeees 260 SSpec_GetfVNUM 0 eee eee eeeeeeeeeeeeeees 96 Directory Navigation SSPCC_BEtEVOPE ssccsescssiss jeessteassieestesecsdecteessgss 97 SSPOC LC io cei a e E 74 sspec_getfvoptlistlen oo eee eeee 98 SSPOC diriS sssi essiri res 79 sspec_getfvreadonly seseeseeeeeereerseeeeeees 99 SSPE PWA retain e a 119 SSpEC_gEtfVSpec ssssssseeeeseeerrrrerrereerrreeee 100 Dynamic RAM Resource Table sspec_getpreformfunction ee 105 sspec_addform oo eee eee eee eseeeeeneeeaee 60 sspec_setformepilog 0 eee eects 131 sspec_addfsfile nnne na 61 sspec_setformfunction sseeeeeeeseereereeee 132 sspec_addfunction essseeeseeseereesrrereeeee 62 sspec_setformprolog eee 133 sspec_addrootfile 00 eee eeeeeseceeeeseeceneeeeee 64 sspec_setformtitle 0 0 ee ceeeeeseeeneeeeeeees 134 sspec_addvariable cc eeceececeeeesseceeeeeees 68 sspec_SsetfVCheCK 0 eeeeeeeeeseeeereeeteeeneeees 135 sspec_addxmemfile ee eeeeeeeeeeeeceneeeeee 69 SSPEC_SetfVAESC irn iai 136 sspec_addxMemvar sseeseseeseeeeerserersee
54. in the lt form action gt parameter of the initial web page The other parameter is the function pointer to the CGI that will process the upload If you do not wish to write a CGI just for handling file uploads you could specify http defaultCGI as the CGI function 198 TCP IP User s Manual Step 8 Create List of Content Type Mappings The HTTP server needs to recognize different file formats This is done using file extensions and MIME types The server shares this information with the browser in its header In this way the browser knows how to handle the file The following code creates a table that maps file extensions to the appropriate MIME type SSPEC MIMETABLE START SSPEC MIME htm text html SSPEC MIME html text html SSPEC MIME gif image gif SSPEC_MIME cgi SSPEC MIMETABLE END This method of creating the MIME type mapping table is new with Dynamic C version 8 5 Step 9 Rule Creation There must be rules to limit the upload facility to select user groups This access control adds security to the system by disallowing unauthorized tampering This is done be assigning a unique user or user group the privilege of uploading new files All other users will be permitted only read access To do this there are several things that need to be coordinated First the user s need to be created and assigned the correct group bit which defines the upload privilege Then the CGI and the f
55. init Initializes the TCP IP stack METO imale z Initializes the web server tcp _reserveport 80 while 1 http_handler Chapter 4 HTTP Server 163 The program serves the static html file and the rabbit1 gif file to any user contacting the controller If you want to change the file that is served by the controller find and modify this line in Static c ximport samples tcpip http pages static html index html Replace static html with the name of the file you want the controller to serve 4 5 1 1 Adding Files to Display Adding additional files to the controller to serve as web pages is slightly more complicated First add an ximport line with the filename as the first parameter and a symbol that references it in Dynamic C as the second parameter ximport samples tcpip http pages static html index html ximport samples tcpip http pages newfile html newfile html Next find these lines in Static c SSPEC RESOURCETABLE START SSPEC_ RESOURCE XMEMFILE index html index html SSPEC RESOURCE XMEMFILE rabbitl gif rabbitl1_ gif SSPEC RESOURCETABLE END Insert the name of your new file preceded by into this structure using the same format as the other lines SSPEC RESOURCETABLE START SSPEC RESOURCE XMEMFILE index html index html SSPEC RESOURCE XMEMFILE newfile html newfile html SSPEC RESOURCE XMEMFILE rabbitl gif rabbi
56. instead of an entry for each re source This works because the full path name is always used for matching and the di rectory will always be a prefix string of the files that reside in that directory As an alternative to this function you can statically initialize a rule table using the fol lowing macros define SSPEC FLASHRULES Required use zserver lib this lib SSPEC RULETABLE START SSPEC RULE prefix realm rg wg sm SSPEC RULE prefix realm rg wg sm SSPEC MM RULE prefix realm rg wg sm meth mime SSPEC MM RULE prefix realm rg wg sm meth mime SSPEC_RULETABLE_END The SSPEC_MM RULE macro parameters are basically the same parameters as would be passed to this function These macros define and initialize a constant rule table named f rule table SSPEC_RULE just omits the rarely used method and mimetype fields When using a static rule table the dynamically added entries are searched before the static ones Chapter 3 Server Utility Library 65 PARAMETER pfx realm readgroups writegroups servermask method mimetype RETURN VALUE 20 OK Prefix of resource name This must include the initial charac ter since all matching is done using absolute path names If this prefix string exactly matches an existing entry in the table that en try is replaced Otherwise a new entry is created if possible This string is not copied only the pointer is stored Thus
57. object list and server authorization list along with some user speci fied data if set up with sspec_setsavedata to the file system This does not save the actual files and variables but only the structures that reference them If the files are stored in flash then the references will still be valid Files in volatile RAM and vari ables must be rebuilt through other means RETURN VALUE 0 Successfully save the server_spec and server_auth tables 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_restore sspec_setsavedata Chapter 3 Server Utility Library 129 sspec seek int sspec seek int sspec long offset int whence DESCRIPTION Seek to specified offset in the file resource The next sspec_read or sspec_write call will start at this position Note that offsets that are not in the file are clamped to the start or end of the file as ap propriate Clamp is terminology meaning that a value past the end is set to the end or a value be fore the beginning is set to the beginning For example if a file is actually 10 bytes then seek to position 20 is actually a seek to position 10 Likewise seek to 20 is set to po sition 0 PARAMETERS sspec Open file handle This must be a handle that was returned by sspec_open offset Byte offset whence Reference point for seek One of the following constants SEEK_ SET start of file offset should be non negative SEEK CUR current position in file
58. of 192 characters Currently only one recipient is supported String containing the e mail address of the source Maximum of 192 characters for a return address If no return should be sent by receiv er then pass an empty string String containing the subject of the message This may be NULL in which case no subject line will be sent This string may also contain embedded r n sequences so that additional mail header lines may be inserted The length of this string is unlimited String containing the message This string must not contain the byte sequence r n r n CRLF CRLP as this is used to mark the end of the e mail and will be appended to the e mail automatically This message must be null terminated and is only allowed to con tain 7 bit characters You can pass NULL if a data handler is to be used to generate the message smtp status smtp_sendmailxmem Chapter 8 SMTP Mail Client 319 smtp sendmailxmem void smtp sendmailxmem char to char from char subject long message long messagelen DESCRIPTION Start an e mail being sent This is intended for moderately long fixed messages that are stored in extended memory e g via ximport ed file See smtp sendmail for more details PARAMETERS to String containing the e mail address of the destination from String containing the e mail address of the source subject String containing the subject of the message message Physical address in
59. of parameters 158 TCP IP User s Manual HTTP PORT This macro allows the user to override the default port of 80 HTTP IFACE This macro allows the user to override the default listening network interface The de fault is IF_ANY meaning that the HTTP server s will listen for incoming network connections on all interfaces which are up You can restrict the HTTP servers to a single interface by overriding this macro to the specific interface number for example IF ETHO HTTP TIMEOUT Defines the number of seconds of no activity that can elapse before the HTTP server closes a connection The default is 16 seconds HTTP USERDATA SIZE This macro causes char userdata to be added to the Ht tpState structure Define your structure before the statement Huse HTTP LIB struct UserStateData char name 50 int floor int model define HTTP USERDATA SIZE sizeof struct UserStateData use http lib In your own CGI function code access it using mystate struct UserStateData http getUserData state USE HTTP DIGEST AUTHENTICATION Set to 1 to enable digest authentication 0 to disable digest authentication Set to 0 by default USE HTTP BASIC AUTHENTICATION Set to 1 to enable basic authentication 0 to disable basic authentication Set to 1 by de fault 4 2 1 Sending Customized HTTP Headers to the Client The callback macro HITP_CUSTOM_ HEADERS will be called whenever HTTP headers are being sent It must be defin
60. or NULL If NULL the MIME type will be derived from the file name using the MIMETypeMap table called http types If not found in that table the first entry in that table will be used for backward compatibility Historical note Prior to Dynamic C 8 50 HttpRealm was used in place of ServerPermissions If you have used HttpRealm for password protection in existing Chapter 3 Server Utility Library 35 code and are upgrading to Dynamic C 8 50 or later you must rewrite any code that used this old structure For an example of the new way to password protect an entity see the sample program samples tcpip http authentication c 3 1 5 RuleEntry Structure This structure associates a resource name prefix with a ServerPermissions structure The rule table is an array of these structures prefix Prefix of resource name s which are associated with this rule table entry If there are multiple entries which match a resource name then the rule with the longest matching prefix is used perm ServerPermissions to use for this entry 3 1 6 ServerContext Structure Starting with Dynamic C 8 50 context information must be maintained by each server that wants Zserver functionality Therefore servers must provide a ServerContext struct when required The fields of ServerContext are userid This field identifies the current user server This field identifies the server for example SERVER_HTTP This is one of the few cases where only a single se
61. out the human readable page The symptom is that the browser appears to time out This timing problem may be masked when a proxy server is used Set MAX_TCP_ SOCKET BUFFERS and HTTP _MAXSERVERS to a value more than one to prevent this problem Chapter 4 HTTP Server 203 PARAMETERS state Current server struct as received by the CGI function url Fully qualified URL to redirect to RETURN VALUE None sets the state so the CGI must immediately return with a value of 0 LIBRARY HTTP LIB SEE ALSO cgi_sendstring cgi sendstring void cgi _sendstring HttpState state char str DESCRIPTION Sends a string to the user You should immediately issue a return 0 after calling this function The CGI is considered finished when you call this and will be in an un defined state This function greatly simplifies a CGI handler because it allows you to generate your page in a buffer and then let the library handle writing it to the network PARAMETERS state Current server struct as received by the CGI function str String to send RETURN VALUE None sets the state so the CGI must immediately return with a value of 0 LIBRARY HTTP LIB SEE ALSO cgi _redirectto 204 TCP IP User s Manual http abortCGI int http _abortCGI HttpState state DESCRIPTION Terminate this CGI request The client will receive an error message indicating the con nection was closed The CGI should not make any fu
62. p x must point to static storage that is a string constant or a global variable Initial characters other than are reserved for future use If not NULL is an arbitrary null terminated string that may be used by the server For HTTP this is used as the realm of the re source This string is not copied only the pointer is stored Thus the parameter must point to static storage A word with a bit set for each group that can access this resource for reading A maximum of 16 different user groups can exist A word with a bit set for each group that can access this resource for writing The user must also be given write permission to re sources in the userid table entry for the appropriate server s The server s that are allowed to access this resource Servers have predefined bits This parameter should be a combination of SERVER_HTTP web server SERVER_FTP file transfer protocol server SERVER_SMTP email SERVER_HTTPS secure web server SERVER_SNMP SNMP agent e SERVER_USER user defined server SERVER_ANY for all servers Allowable authentication method s to be used when accessing this resource If zero then the resource has no particular authenti cation method requirements This is a bitwise combination of SERVER_AUTH_ BASIC plaintext userid password SERVER AUTH DIGEST challenge response protocol SERVER _AUTH_PK public key such as SSL TLS An appropriate MIME type
63. physical connection eee eee eeeeeeeee 358 terminal emulator 0 0 0 eccccceceseseseeeeseees 367 using TCP IP inie ees 358 382 TCP IP User s Manual
64. processing to a different CGI function or resource The CGI is responsible for generating the correct HTTP response header s using http write etc If this function is used to pass control to a different CGI then both CGIs must coordinate so that only one header is written You can use the HTTP state variable http setState andhttp_ getState and or http _getUserState to achieve the necessary coordination If newURL refers to a file or SSI resource not a CGI then the CGI function must NOT have already written the HTTP response header s the headers will be generated when the new resource is opened If newURL refers to a new style CGI that is a CGI resource added using SSPEC_CGI not SSPEC_ FUNCTION then that CGI is presented with the remaining content of the current request data stream If newURL refers to an old style CGI that is a CGI added using SSPEC_ FUNCTION or HTTPSPEC FUNCTION then the HTTP server abandons parsing of the request data stream since old style CGIs are expected to read the HTTP socket themselves Rather than calling http_switchCGI it is often more convenient to call cegi_redirectto which tells the client to retrieve the next resource rather than the resource being provided in the current connection Using redirect is less efficient however PARAMETERS state HTTP state pointer as provided in the first parameter to the CGI function newURL The resource name to present to the client This ma
65. shutdown int bGraceful DESCRIPTION Close and cancel all FTP connections If the server is connected to a client forces the QUIT state If the application has called tcp_reserveport then it must call tcp _clearreserve Fora graceful shutdown the application must call tcp _tick afew more times After the FTP sockets close the application must call ftp init to again start the server running PARAMETER bGraceful boolean zero to immediately abort all open connections or non zero to simulate the QUIT command RETURN VALUE None LIBRARY FTP SERVER LIB SEE ALSO ftp init 296 TCP IP User s Manual ftp tick void ftp tick void DESCRIPTION Once ftp_init has been called ftp tick must be called periodically to run the server This function is non blocking LIBRARY FTP SERVER LIB SEE ALSO ftp init Chapter 6 FTP Server 297 6 4 Sample FTP Server This code demonstrates a simple FTP server using the ftp library The user anonymous may download the file rabbitA gif but not rabbitF gif The user foo with password bar may download rabbitF gif but also rabbitA gif since files owned by the anonymous user are world readable File Name Samples tcpip ftp server c define TCPCONFIG 101 define SSPEC NO STATIC Required for DC 8 50 or later memmap xmem puse dorccp alo use ftp server lib ximport samples tcpip http pages rabbit1 gif rabbitl gif main i
66. string If this starts with it is merely appended to the context gt rootdir string Otherwise it is appended to the current directory in context gt cwd Directory components are separated by characters A trailing slash is optional A directory component means no change to this level and a component of means up one level towards the root context Server context structure Two fields in this are of interest rootdir points to a virtual root directory for this server For ex ample if the FTP server is only allowed to access files under the A directory then root dir points to a string A If the user entered a directory name of ftpfiles the full directory would be A ftpfiles The other field that is updated by this function is cwd This is an array of characters of length SSPEC_MAXNAME It contains the absolute path of the current directory with leading and trailing slash including the rootdir part if any check If TRUE check the resulting directory name to see if it exists Oth erwise no check is made RETURN VALUE 0 OK Any other negative values indicate an error E2BIG Resulting directory name too long EACCES Attempt to change above root directory ENOENT 3rd parameter was TRUE and the directory did not exist SEE ALSO sspec_pwd 74 TCP IP User s Manual sspec checkaccess int sspec checkaccess int sspec int userid DESCR
67. that will be used for form processing This buffer must be large enough to hold the name and value for each variable plus four bytes for each variable Since we are building a small form 256 bytes is sufficient define FORM ERROR _BUF 256 Since we will not be using the static resource table we can define the following macro to remove some code for handling this table from Zserver define HTTP NO FLASHSPEC These lines are part of the standard TCP IP and MIME table configuration memmap xmem tuse dertep lib use http lib SSPEC MIMETABLE START SSPEC MIME html text html SSPEC MIMETABLE END These are the declarations of the variables that will be included in the form int temphi int tempnow int templo float humidity Char fail 21 176 TCP IP User s Manual void main void An array of type FormVar must be declared to hold information about the form variables Be sure to allocate enough entries in the array to hold all of the variables that will go in the form If more forms are needed then more of these arrays can be allocated FormVar myform 5 These variables will hold the indices in the TCP IP servers object list for the form and the form variables int var TE EON This array holds the possible values for the fail variable The fail variable will be used to make a pulldown menu in the HTML form
68. the buffer provided by the http_getData call Alternatively the CGI can simply redirect back to another local or even remote web page and not bother writing anything itself If the CGI wants to generate the response itself then this has the advantage of being slightly more efficient but the disadvantage of requiring more code in the CGI Usually the application already has some sort of web page that can display the necessary results This is often an SSI page that is dynamically generated using a specialized function or may be just a static page for example index htm1 Action Code CGI_EOF Since referring to another web page is easiest it is shown first case CGI_ EOF egi_redirectto s index html break The cgi _redirectto function tells the HTTP server to stop calling this CGI function and tell the client to retrieve its next web page from the specified location in this case the index html page on the current server The onus is on the client browser to go and get that page It will come straight back to this server but the CGI does not have to worry about it Easy Chapter 4 HTTP Server 191 In a similar vein you can use the http _switchCGI function Again the current CGI does not have to generate a response The difference is that the HTTP server goes straight to the speci fied web page and presents it to the client on the same connection rather than requiring the client to come back to
69. the advantage of requiring very little footprint in the client host 7 1 BOOTP DHCP In conjunction with DHCP BOOTP and appropriate server configuration TFTP is often used to download a kernel image to a diskless host The target TCP IP board does not currently support loading the BIOS in this way since the BIOS and application program are written to non volatile flash memory However the downloaded file does not have to be a binary executable it can be any reasonably small file such as an application configuration file TFTP and DHCP BOOTP can thus be used to administer the configuration of multiple targets from a central server Using TFTP with BOOTP DHCP requires minimal additional effort for the programmer Just define the symbol DHCP_USE_ TFTP to an integer representing the maximum allowable boot file size 1 65535 See the description of the variables bootpsize bootpdata and _bootperror in volume 1 of the TCP IP User s Manual for further details Chapter 7 TFTP Client 303 7 2 Data Structure for TFTP This data structure is used to send and receive The t tp_state structure which is required for many of the API functions in TFTP LIB may be allocated either in root data memory or in extended memory This structure is approximately 155 bytes long typedef struct tftp state 4 byte state Current state LSB indicates read 0 or write 1 Other bits determine state within this see below long buf addr
70. the server with a new request http switchCGI can transfer control to any local web page as if the client had directly requested that resource If the resource happens to be another new style CGI like the one we are describing then it gets control with the current action code which will usually be CGI_ EOF Otherwise the resource is processed as if it was directly retrieved by the client by name Note the current CGI must not have written anything back to the client otherwise the data wil not be intelligible to the client Here is an example case CGI_ EOF http switchcGI s index html break As you can see it is very similar to the cgi_ redirectto case Action Code CGIl_ABORT The conventions for having the CGI generate its own response back to the client are covered in the next section titled Writing Responses to the Client from a CGI Function First we look at the proper handling of a CGI_ ABORT action code This code means that the connection has been lost and there is no point in handling any more incoming data or generating any response Thus pro cessing of CGI_ ABORT is necessarily limited to cleaning up any open files or other resources case CGI ABORT handle http _getCond s COND HANDLE sspec_close handle break In this example we simply close the handle possibly leaving the file with partially written con tents It is important to do this since if the handle is left open then that hand
71. to accept a connection from anybody Option flags for this gateway Currently the only valid bit flags are VSERIAL COOKED to strip out telnet control codes or 0 to leave it a raw data link 336 TCP IP User s Manual vserial open int vserial open int id long baud int port long remote host int flags long retry DESCRIPTION Opens a connection to a remote host and maintains it starting the gateway process PARAMETERS id baud port remote host flags retry RETURN VALUE 0 Success 1 Failure LIBRARY VSERIAL LIB ID of the gateway to change as specified in the spec table The parameter to send to the open serial port command it s usu ally the baud rate The TCP port on the remote host to connect to The remote host to connect to Option flags for this gateway Currently the only valid bit flags are VSERIAL COOKED to strip out telnet control codes or 0 to leave it a raw data link The retry time out in seconds When a connection fails or if the connection was refused we will wait this number of seconds before retrying Chapter 10 Telnet 337 vserial tick int vserial tick void DESCRIPTION Runs the telnet daemon must be called periodically RETURN VALUE 0 Success 1 Failure But call it periodically no matter the return value An error message can be seen when 1 is returned if you define VSERIAL DEBUG at the top of your program LIBRARY VSERIAL
72. to use If NULL then the default table called http types will be consulted 1 Error For example out of space in rule table increase SSPEC_MAXRULES SEE ALSO sspec_removerule sspec_getMIMEtype 66 TCP IP User s Manual sspec adduser int sspec adduser int sspec int userid DESCRIPTION Add to the read permission mask for the given resource The groups that userid is a member of are ORed into the existing permission mask for the resource The write permissions are not modified NOTE This is not used to create new userids For that see sauth_adduser Adds a user to the list of users that have access to the given spec entry Up to SSPEC_USERSPERRESOURCE users can be added Any more than that will result in this function returning 1 This function is deprecated as of Dynamic C 8 50 Use the more general sspec_setpermissions function instead PARAMETERS sspec Spec index userid User index RETURN VALUE 20 Success index of userid added for given spec entry 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_setuser sspec_getusername sspec_getuserid sspec_removeuser sspec_setpermissions Chapter 3 Server Utility Library 67 sspec addvariable int sspec addvariable char name void variable word type char format word servermask DESCRIPTION Adds a variable to the dynamic resource table aka the RAM resource list Make sure that SSPEC_MAXSPEC is large enough to hold thi
73. up a resource called A admin index htm If it is not a directory then the default name is not used PARAMETERS rootdir Root directory name to use This must be a null terminated string and MUST start and end with a forward slash character If this function is not called the root directory name is set to by http init dfltname Default file name to use This is appended to the directory part of the URL if the URL actually refers to a directory If this function is not called the default file name is set to index html by http_init If this parameter is NULL there will be no default name A request for a directory will generally return a 404 error not found to the client If it is not NULL this parameter must be a null terminated string It must not start or end with a character RETURN VALUE 0 OK E2BIG rootdir was too long It should be limited to less than about 12 characters but you can increase the value of SSPEC_MAXNAME if necessary EINVAL rootdir was NULL or did not start and end with a forward slash character LIBRARY HTTP LIB SEE ALSO http handler http_init Chapter 4 HTTP Server 245 http setState int http setState HttpState state int val DESCRIPTION Set the current primary HTTP CGI state variable Use of this state variable is entirely up to the application however it is initialized by the HTTP server to zero before calling the CGI for the first time NOTE
74. userid not valid 50 TCP IP User s Manual sauth getusername char sauth getusername int userid DESCRIPTION Returns the name of the user a character string from the ServerAuth structure asso ciated with userid PARAMETERS userid The user s id that is the index into the user table RETURN VALUE NULL Failure NULL Success pointer to the user s name string LIBRARY ZSERVER LIB SEE ALSO sspec_getusername Chapter 3 Server Utility Library 51 sauth getwriteaccess int sauth_getwriteaccess int sauth DESCRIPTION Checks whether or not a user has write access to any server s resources This is an in principle test Each resource is individually protected from write access this is not checked In other words this function may return TRUE even when none of the re sources are writable to this user PARAMETERS sauth Index into the user table RETURN VALUE 0 User does not have write access 1 User has write access 1 Failure LIBRARY ZSERVER LIB SEE ALSO sauth_setwriteaccess 52 TCP IP User s Manual sauth removeuser int sauth removeuser int userid DESCRIPTION Remove the given user from the user list IMPORTANT Any associations of the given user with web pages should be changed Otherwise no one will have access to the un changed web pages Authentication can be turned off for a page with sspec setrealm sspec PARAMETERS user
75. xmem containing the message The message must NOT contain the byte sequence r n r n CRLE CRLF as this is used to mark the end of the e mail and will be appended to the e mail automatically messagelen Length of the message in xmem RETURN VALUE None LIBRARY SMTP LIB SEE ALSO smtp _mailtick smtp _status smtp_sendmail 320 TCP IP User s Manual smtp setauth int smtp setauth char username char password DESCRIPTION Sets the username and password to use for SMTP AUTH Authentication You must define USE SMTP AUTH in your program if you want to use SMTP AUTH on your outbound connections To disable SMTP authentication set both username and 609 password to empty strings PARAMETERS username This is copied into the SMTP state structure Note that some SMTP servers require a full email address while others just want a user name password This is copied into the SMTP state structure RETURN VALUE SMTP_OK server name was set successfully SMTP_USERNAMETOOLONG the username was too long SMTP_PASSWORDTOOLONG the username was too long SEE ALSO smtp sendmail smtp_mailtick Chapter 8 SMTP Mail Client 321 smtp setserver int smtp setserver char server DESCRIPTION Sets the SMTP server This value overrides SMTP_ SERVER and the results of any pre vious call to smtp_setserver_ip PARAMETER server Server name string This is copied into the SMTP state structure This
76. your C language objects to be turned into HTML fragments for presentation by the browser The small block named web Variables between the Application block and the RabbitWeb cir cle indicates that the web variables are the means of communication between your application and the server Since web variables are really just ordinary C variables arrays or structures they are extremely easy to manipulate by your application Since they also have the property of being registered with the web server the server has easy access too Registering an object with the web server is discussed in the document titled RabbitWeb available on our website The second circle in the HTTP server block represents the classic way of generating dynamic con tent SSI Server Side Includes is also a scripting language It is not nearly as easy to use SSI as it is to use RabbitWeb however an SSI can generate the same content as an RabbitWeb script It is just that you will need to write CGI functions and such functions can get large and complicated fairly quickly In fact SSI has the ability to invoke CGI functions whereas RabbitWeb does not In addition SSIs have the ability to include other resources directly in the primary returned resource much like how include works in ANSI C The server also communicates with lower layers in the diagram On the right hand side is the TCP IP block This is the pipeline to the outside world i e the browser Us
77. APPICANON S u sspec_checkaccess ccecsesecseeeee 75 2 5 A Simple but Realistic Application 13 sspec_checkpermissions 00 76 2 6 Adding Access Controls eeeceeeeeeeee 16 alae bereetereeeeseeeresrereererreeeerereeeet SANS SSPEC delete siirsin 2 7 A Full Featured Application 22 SSPeC_Cirlist rescence 719 2 8 Living Without RabbitWeb and FAT 26 sspec_fatregister s 82 oe sspec_fatregistered ccccceeeeeseeeeees 83 3 Server Utility Library 31 ae cadtt EE ee ee 84 3 1 Data Structures for Zserver lib 31 sspec_findname seeeeeeeteeeeees 85 MIMETypeMap Structure 32 sspec_findfsname rected ceed vavnvensbecdsatiavs 86 sspec_findnextfile ee eeeeeeeeeeeeeee 87 ServerSpec Structure 33 sspec_getfilelOc oo eects 88 ServerAuth Structure 35 sspec_getfiletype 0 eeeseeeseeseneees 89 ServerPermissions Structure 35 sspec_getformtitle ceeeees 90 RuleEntry Structure 36 sspec_getfunction ee eeeeeeeeeneeeeee gt ServerContext Structure 36 T D A a SSpecStat Structure 37 Sspec_gelfVIEM eaa 94 sspec_fatinfo Structure 37 SSpeC_SetfVNAME ceeeeeeeeeeeeeteees 95 FormVar Structure 38 sspec_getfVNUM eee eeeeeeeee 96 SSpecFileHandle Structure 38 peer le ae P EPN PE ieee 3 2 Constants Used in Zserver lib 38 a aa ae ServerSpec Type Field 38 SSPeC_VetfVSPEC oo eects 100 ServerSpec Vartype Field 39 sspec_getlength e
78. BACKUP Causes backup of the IP addresses of the controller board and the IP address of its net mask gateway and name server Note that only one of the CONSOLE TCP __ structures should be used CONSOLE TCP MULTI BACKUP Using this structure causes if config to save and restore network configuration In addition to the information saved by CONSOLE_TCP_BACKUP multiple name servers DHCP configuration ICMP Ping configuration and multiple interface configuration are all saved by CONSOLE TCP MULTI_BACKUP Some built in console functions are for use with CONSOLE TCP MULTI BACKUP In general except for backwards compatibility issues CONSOLE _TCP_ MULTI BACKUP should be used instead of CONSOLE _TCP_BACKUP Note that only one of the CONSOLE TCP __ structures should be used CONSOLE HTTP BACKUP Causes backup of the files and variables visible to the HTTP server CONSOLE SMTP_BACKUP Causes backup of the mail configuration CONSOLE BACKUP LOGIN Causes backup of the ConsoleLogin structure which stores the login name and pass word strings Chapter 11 General Purpose Console 369 11 8 Zconsole Macros Many macros are available to change the behavior of Zconsole They are all listed here Starting with Dynamic C 7 30 additional macros are available to support saving configuration information to the User block DHCP ping configuration and multiple interfaces CON BACKUP FILE1 The file number used for the first backup file For F
79. CGI In general the CGI should pass this code CGI_ MORE back to the HTTP server When the server calls the CGI next time it will set the action code to CGI_ CONTINUE which will be a cue to the CGI to try retransmitting the previous data When CGI_ CONTINUE is provided the contents in the http _getData buffer will not have been altered LIBRARY HTTP LIB SEE ALSO http _getAction http_skipCGI http _switchCGI http finishCGI http_abortCGI http _defaultCGI 262 TCP IP User s Manual shtml addfunction int shtml addfunction char name void fptr DESCRIPTION Adds a CGI SSI exec function for making dynamic web pages to the RAM resource ta ble PARAMETERS name Name of the function e g foo cgi fptr Function pointer to the handler that must take HttpState as an argument This function should return an int 0 while still pending 1 when finished RETURN VALUE 0 Success 1 Failure no room LIBRARY HTTP LIB SEE ALSO shtml _delfunction Chapter 4 HTTP Server 263 shtml addvariable int shtml addvariable char name void variable word type char format DESCRIPTION This function adds a variable so it can be recognized by shtml_handler PARAMETERS name Name of the variable variable Pointer to the variable type Type of variable The following types are supported INT8 INT16 INT32 PTR16 FLOAT32 format Standard printf format string e g d RETURN VALUE 0 Succes
80. CGI which processes the file as it is uploaded in which case you do not need to store it permanently and thus you do not need to include a file system the following dis cussion assumes that you are using a file system Chapter 4 HTTP Server 183 Steps 2 3 and 4 Specify File system and Web Server You need to include the file system library or libraries before including http 1ib This is because the HTTP library needs to know about the filesystem s it is going to support In addition you need to tell the HTTP library to use the upload facility For example if you want to use the FAT file system then you would write the following define TCPCONFIG 1 use dertcp lib use fat lib Step 2 the filesystem define USE HTTP UPLOAD Step 3 enable upload feature use http lib Step 4 HTTP server code The order of the above statements is important A possible exception is that the order of dertcp lib and fat 1ib may be interchanged since these libraries are independent How ever it is recommended you use the given ordering since future releases of the FAT may be able to use networking services Step 5 Create a Web Page When using HTTP upload there needs to be a way to prompt the user web browser to enter a file name to upload This is done by using an HTML form The form specifies input fields that may be filled out by the user and one or more submit buttons that the user presses to start the upl
81. Client 307 tftp tickx int tftp tickx long ts addr DESCRIPTION This function is a wrapper for calling tftp tick where the structure is possibly stored somewhere other than in the root data space See that function description for de tails PARAMETERS ts addr Physical address of TFTP state struct tftp state RETURN VALUE 1 OK transfer not yet complete 0 OK transfer complete 1 Error from remote side transfer terminated In this case the ts_addr gt file field will be overwritten with a NULL terminated error message from the server 2 Error could not contact remote host or lost contact 3 Timed out transfer terminated 4 not used 5 Transfer complete but truncated buffer too small to receive the complete file LIBRARY TFTP LIB 308 TCP IP User s Manual tfitp exec int tftp exec char put long buf addr word len int mode char host char hostfile udp Socket sock DESCRIPTION Prepare and execute a complete TFTP session blocking until complete This function is a wrapper fortftp_init andtftp_tick It does not return until the complete file is transferred or an error occurs Note that approximately 750 bytes of free stack will be required by this function PARAMETERS put 0 get file from remote host 1 put file to host buf addr Physical address of data buffer len Length of data buffer This is both an input and a return parameter It should be initialized to the bu
82. DHCP BOOTP See BOOTP DHCP p_ge e 10 ee the RAD BA ae http_getHTTPVersion 000 eeeeeeeeeeneees 227 directory listing ee ceeeeeseceseeceseeeneeeeeeesseeeeeeees 79 e S dynamic webpages 165 http_getRemainingLength oe 228 ay gis one Gop lee http_getSocket cccccssseseeseeeeseseteessenes 229 E http_getState oo seret eriei 230 http_getTransferEncoding 0 0 231 e mail http getURL async 232 POPS Cheni Metssoecsssetdectedtecteweseueoeeiwe sche 325 331 http_getUserState a hire onde Bano a sonra 233 SMTP client 224R8 cae nets 311 323 http_setCond sc heen din oh pes 243 entries in directory es seseeeeeeserseeesreesersressresees 79 http_setState ssssssesssssssesssssesseressseesseeee 246 TCP IP User s Manual 379 http_skipCGI oe ee eeeeecreeeeeeeee 248 smtp_sendmailxmem eee 320 http_sock_bytesready cs ceeeeeeeeseeeeeee 249 SMtp statUS ine a 323 http_sock_fastread 0 eee eee eee 250 File System Specifics Http SOCK Pets ice ssscessessseesceeesiscesssszsonsese s 252 SSPCC_AULOMOUNL 00 ee eeeeeeeeseeceseeeeneeeeees 72 http_sock_Mode eee ceeeeesseceeeeeeeeeeeeeeee 253 Sspec_fatregister cee eeeeeseceeeeeseeeeeeeeee 82 http_sock_tbleft 0 eee eeseceeeeeseeeeeeeeeee 254 sspec_fatregistered 0 eee eeeeeeeeeeeceneeeeee 83 http_sock_write oo eee eee ceeeeeneeeeeeeeeee 255 FTP Client http_sock_xfastread 0 00 eeceeceeeeeeeneeeeeee 256 ftp chent filesize snide 270 http_sock_xfast
83. EOUT The default is 16 the number of seconds to wait for FTP commands from the remote host before terminating the connection In a high latency network this value may need to be increased to avoid premature closures FTP USE FS2 HANDLERS Define this to enable the full use of FS2 in the default FTP handler functions Defining this macro will automatically define FTP_WRITABLE FILES to 1 as well FTP USERBLOCK OFFSET This macro should be defined to a number that specifies the offset into the User block at which the list of filenames will be saved This list correlates the filenames with the locations of the files in the filesystem FS2 This macro defaults to 0 If the user is putting other information in the User block this offset may need to be adjusted to pre vent clobbering the other data FTP WRITABLE FILES The defaults is 0 Define to 1 to provide support in ftp df1lt open for authen ticating a user for write access before a file is opened This also provides support in the file listing function ftp _df1t_list to show the write permission for writable files NOTE The user will need to override both the write and close default file handlers to provide full support for writing a file SSPEC NO STATIC This macro must be defined in any FTP server application compiled with Dynamic C 8 50 or later Chapter 6 FTP Server 279 6 2 File Handlers Default file handlers are provided The defaults access the server spec
84. ETURN VALUE NULL Failure or no user has read access to this resource NULL Success pointer to username LIBRARY ZSERVER LIB SEE ALSO Sauth_adduser sspec_setuser sauth_getuserid sauth_getusername 110 TCP IP User s Manual sspec getvaraddr void sspec getvaraddr int sspec DESCRIPTION Returns a pointer to the requested variable in the resource list PARAMETERS sspec spec index RETURN VALUE NULL Failure NULL Success pointer to variable LIBRARY ZSERVER LIB SEE ALSO sspec_readvariable Chapter 3 Server Utility Library 111 sspec getvarkind word sspec getvarkind int sspec DESCRIPTION Returns the kind of variable represented by sspec PARAMETERS sspec spec index RETURN VALUE 0 Failure On success returns one of e INTS8 single character e INT16 2 byte integer e PTR16 string in root memory e INT32 4 byte long integer e FLOAT32 floating point variable LIBRARY ZSERVER LIB SEE ALSO sspec_getvaraddr sspec_getvartype sspec_gettype 112 TCP IP User s Manual sspec getvartype word sspec getvartype int sspec DESCRIPTION Gets the type of variable represented by the spec index PARAMETERS sspec spec index RETURN VALUE SSPEC_ERROR Failure SSPEC_ROOTVAR or SSPEC_XMEMVAR Success LIBRARY ZSERVER LIB SEE ALSO sspec_getvaraddr sspec_getvarkind sspec_gettype sspec getxvaraddr long sspec getxvaraddr int s
85. Failure LIBRARY VSERIAL LIB 334 TCP IP User s Manual vserial keepalive int vserial keepalive int id long timeout DESCRIPTION This function sets the keepalive timer to generate TCP keepalives after timeout pe riods of inactivity This helps detect if the connection has gone bad Keepalives should be used at the application level but if that is not possible then timeout should be set so as to not overload the network The standard timeout is two hours and should be set sooner than that only for a Very Good Reason PARAMETERS id Unique gateway identifier timeout Number of seconds of inactivity allowed before a TCP keepalive is sent A value of 0 shuts off keepalives RETURN VALUE 0 Success 1 Failure LIBRARY VSERIAL LIB Chapter 10 Telnet 335 int vserial listen int id remote host DESCRIPTION vserial listen long baud int port int flags long Listens on the specified port for a telnet connection The gateway process is started when a connection request is received On disconnect re listen happens automatically PARAMETERS id baud port remote host flags RETURN VALUE 0 Success 1 Failure LIBRARY VSERIAL LIB The local TCP port to listen on ID of the gateway to change as specified in the spec table The parameter to send to the open serial port command it s usu ally the baud rate The remote host from whom to accept connections or 0
86. Firewall If a client is behind a firewall it is incumbent upon the client to request that the server do a passive open on its data port instead of the normal active open This is so that the client can then do an active open using the passively opened data port of the server thus getting through the firewall Typically the server would not be behind a firewall 6 6 FTP Server Commands The following commands are recognized by the FTP server The reply codes sent in response to these commands are detailed in Section 6 7 on page 301 They are noted here to associate them with the commands that may cause them to be sent Table 6 2 Recognized FTP Server Commands es Possible Command Description Reply Codes Aen The current data transfer completes before the abort command is 226 read by the server CDUP A special case of CWD Change Working Directory the parent of 250 431 the working directory is changed to be the working directory CWD Changes working directory 250 431 DELE Delete the specified file 250 450 550 LIST Displays list of files requested by its argument in ls 1 format This 150 226 425 gives extra information about the file Tann ane A PEREA 213 250 MDTM Shows the last modification time of the specified file 450 550 HODE Confirms the mode of data transmission Only stream mode is 200 504 supported Displays list of files requested by its argument with names only MST This a
87. HF X This array defines the commands that are available in the console The first parameter for the ConsoleCommand structure is the command specification i e how the console recognizes acommand The second parameter is the function to call when the command is recognized The third parameter is the location of the ximport ed help file for the command Note that the second parameter can be NULL which is useful if help information is needed for something that is not a command like for the SET command below the help file for SET contains a list of all of the set commands Also note the entry for the command which is used to set up the help text that is displayed when the help command is used by itself that is with no parameters const ConsoleCommand console commands HELLO WORLD hello world 0 MECHOM COU sIechoy He hon echowert ty HELPYs con help Help helo txt Ces NU melag ese Yy wemi a NUN aello ser ese Jy SET PARAM con set param help set_param txt m mrm Sateen mermar This array sets up the error messages that can be generated CON STANDARD ERRORS is a macro that expands to the standard errors used by the built in commands in zconsole lib Users can define their own errors here as well const ConsoleError console errors CON STANDARD ERRORS Ve This array defines the information such as configuration that will be saved to the file system Note that if for example
88. HTTP HEADERS END_HTTP_HEADERS is simply a macro NULL that indicates the end of the structure These headers will be saved in an internal buffer of a user specified size define HTTP_CUSTOM_HEADERS_SIZE 1024 By default HTTP_CUSTOM_HEADERS_SIZE is undefined which disables the custom header functionality since in most cases it will not need to be used This buffer will be located in xmem and there will be one per HTTP server A define will also be provided to limit the maxi mum size of a single header to keep one very long header from monopolizing all of the buffer space define HTTP_CUSTOM_HEADER_MAX_SIZE 128 By default this is undefined and there is no limit The user will also need functions that look up the data int http getheader HttpState state char header char dest int destlen int http xgetheader HttpState state char header long destptr The first function requires the user to provide a root buffer to place the header The HttpState state structure must be passed so that the server knows which set of headers to access The header parameter is of course the name of the header the user wants to retrieve dest is a pointer to the destination buffer destlen is the length of the destination buffer provided by the user The function returns 1 on error and the number of bytes in the header on success 160 TCP IP User s Manual The second function http _xgetheader simply returns a long pointer i
89. ION Returns the most recent message code sent by the FTP server RFC959 describes the codes in detail This function is most useful for error diagnosis in the case that an FTP transfer failed RETURN VALUE Error code a number between 0 and 999 Codes less than 100 indicate that an internal error occurred e g the server was never contacted LIBRARY FTP CLIENT LIB SEE ALSO ftp_client_setup ftp client _tick 274 TCP IP User s Manual 5 3 Sample FTP Transfer Program Name Samples tcpip ftp ftp_client c detine MY IP ADDRESS 10 10 6 105 define MY NETMASK 255 255 255 0 define TCPCONFIG 1 memmap xmem ose derteep lib use ftp client 1lib define REMOTE HOST 10 10 6 19 define REMOTE PORT 0 main char buf 2048 Wie TEE ah J A oree Meene Goes ate 4 VaT sock init Set up the ftp transfer This is to the host defined above with a normal anonymous e mail password login info A get of the file bar is requested which will be stored in buf printf Calling ftp client setup n if ftp client setup resolve REMOTE HOST REMOTE PORT anonymous anon anon com FTP MODE DOWNLOAD bar NULL buf sizeof buf pramet Vigil sSicwie iam Ile in exit 0 printer Ykeopiine om ito Celicne tiek a 5 while HSE reo Clligme cick continue if l vee yf printf FTP completed successfully n ftp client fil
90. IPTION This function checks whether or not the specified user has permission to access the specified resource in the resource table Only read access is checked This function is deprecated as of Dynamic C 8 50 Use the function sspec_checkpermissions instead PARAMETERS sspec spec index userid user index RETURN VALUE 0 User does not have access 1 User has access 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec needsauthentication sspec_checkpermissions Chapter 3 Server Utility Library 75 sspec checkpermissions int sspec checkpermissions int sspec ServerContext context DESCRIPTION Returns the access permissions for the given server and user for the given resource sspec_access performs the same function except that a resource name can be given rather than an open resource handle PARAMETERS sspec spec index context Server context The relevant fields are context gt server the current server SERVER _HTTP etc context gt userid current user or 1 for testing the server in general When testing the server in general both O_READ and O WRITE will be returned RETURN VALUE 20 Bitwise combination of e O READ resource is readable e O WRITE resource has write permission This does NOT necessarily mean that the resource can actually be written only that the permission bits allow it lt 0 Error For example no permissions can be located or the sspec handle is inval
91. If this is less than len an error occurred 1 Error 284 TCP IP User s Manual ftp dflt close int ftp dflt_close int fd DESCRIPTION The default close handler does nothing but return zero The handler may close the specified file and free up any temporary resources associated with the transfer PARAMETERS fd The file descriptor returned when the file was opened RETURN VALUE 0 Chapter 6 FTP Server 285 ftp dflt list int ftp dflt list int item char line int listing int uid int cwd DESCRIPTION Returns the next file for the FTP server to list The file name is formatted as a string PARAMETERS item line listing uid cwd RETURN VALUE Index number starting at zero for the first function call Subsequent calls should be one plus the return value from the previous call Pointer to location to put the formatted string Boolean variable to control string form 0 print file name permissions date etc 1 print file name only The currently logged in user The current working directory 20 File descriptor for last file listed 1 Error 286 TCP IP User s Manual ftp dflt cd int ftp dflt_cd int cwd char dir int uid DESCRIPTION Change to new directory This is called when the client issues aC WD command The FTP server itself has no concept of what a directory is this is meaningful only to the handler PARAMETERS cwd Integer repres
92. It is unwise to make direct calls to TCP IP functions especially functions that may not return for a long time such as sock_read 186 TCP IP User s Manual How to Transfer Form Submission Data To understand how to write a CGI function it is necessary to have some understanding of the pro tocol used to transfer the form submission data Since the data can consist of one or more files and or form fields there needs to be a way of separating them within the one sequential stream of data that is sent by the client The way this is done is that the client specifies a unique string that separates each item of data The following text is a dump of the actual data sent by a client with some irrelevant details omitted and with comments added in italics POST upload cgi HTTP 1 1 This indicates that it is POSTed form data and the target handler is upload cgi Content length 277 This gives the total number of bytes of data following the initial header Content Type multipart form data boundary 3vAL1QsFOUg2GsY3p6n3YQ The multipart form data type indicates that this is a multipart form data submission The boundary parameter specifies a unique character sequence that separates each part The boundary is deliber ately chosen as a long random string of characters so that it is unlikely to be confused with the actual data content The above blank line is significant it indicates the end of the initial header lines and the start of da
93. L it receives and generates a nice visual rendition of the contents Chapter 2 Web Enabling Your Application 5 2 3 Web Server Architecture Before describing a real application it is useful to know how such an application is organized The following diagram shows all of the relevant components of a web enabled application There may seem to be a large number of components however keep in mind that not all components need to be used by your application Application Compile Time Run Time Main Application CGI Initialization Initialization Loop Specifics I O Functions Variables MS i i Requests MIME Resources Context i Table Zserver TCP IP H z Resource Manager nerens Virtual File System 3 Metadata ener File Systems Static Dynamic i Resource Resource FAT i Table Table l Storage Serial Flash i cos s Program Second Flash Flash Figure 2 1 Components in a web enabled application TCP IP User s Manual 2 3 1 Application Block At the top of this diagram is a block called Application consisting of five sub blocks The Application block represents the code that you have to create Everything below this is provided by the libraries although you will need to specify some parts of the interface to these components This will be described in detail in the following sections The application block is subdivided into 5 parts 1 Compile time initialization Thi
94. MOVEUSET cece cecceceeeeeeeeeseeesens 53 basic authentication ccccceeeeeeseseeeseseseeeseeees 161 sauth_setpassword eecsceesssesssseesssseesseeesees 54 BOOTP DHCP sauth_Ssetserver cceceeececcececscseeceseesesecesens 55 used With TETP a aiins eissioes 303 sauth_setusermask ccccccccccsccssssessecsecseseesseeee 56 C sauth_setwriteaccess escsesesesrererererereeseee 57 CGI callbacks CEL COMUNE irea en iaeio neei 202 FTP data transfers c ccccccecsscseseseseeeseeee 272 Cgi redirectto aaier A ae 203 sending HTTP headers arenscrsanioranre 159 Cr SONASTING irssi es 204 COT E A ate oe 154 169 http_abortCGI occ cece ceeeceeneeeees 205 console serial based ccccccesceeseseeees 343 376 http_defaultCG oo eee sinen 209 http_finishCGI oe eee eee eeeseeteeteeeees 214 D Http SetA CHOON nan ninnisin 215 Jaemons http_getCond ssssseeesseeesseesresrsrrersrrerssre 217 FTP client 269 http_getContentDisposition oe 218 eae AEA Ee PER ALOE SENT EE EEE htp sei Contenthensthy moienn 219 FTPserver uien neee E 297 HTTP server 234 http_getContentType ec eeceeeeseeeneees 220 BOBS clet T 329 http_getContext 00 ceccceceeeseeeeeeseeeeees 222 ic ene SRR TUNE Writ SEN 340 http_getData eruere reee areno eN nE 223 a Ee ieee hie eee coi tet E E oan eat c ed lip PeDe enet ta eae cet hea 224 PoS AEn aE E eE http_getField ssscsssssscsessssssssssssssssssseseees 225 ZCONSOIE i n athe om 359 htt t HTTPMethod 226
95. Manual sspec setfvcheck int sspec setfvcheck int form int var int varcheck DESCRIPTION Sets a function that can be used to check the integrity of a variable The function should return 0 if there is no error or 0 if there is an error PARAMETERS form spec index of the form var Index into the FormVar array of the variable varcheck Pointer to integrity checking function RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_setfvfloatrange sspec_setfvoptlist sspec_setfvrange Chapter 3 Server Utility Library 135 sspec setfvdesc int sspec setfvdesc int form int var char desc DESCRIPTION Sets the description of a variable that is displayed in the HTML form table PARAMETERS form server spec index of the form var Index into the FormVar array of the variable desc Description of the variable This text will display on the HTML page RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_getfvdesc 136 TCP IP User s Manual sspec setfventrytype int sspec setfventrytype int form int var int entrytype DESCRIPTION Sets the type of form entry element that should be used for the given variable PARAMETERS form spec index of the form var Index into the FormVar array of the variable entrytype HTML FORM TEXT for a text box HTML FORM PULLDOWN for a pull down menu The default is HTML FORM_TEXT RETURN VALUE 0
96. PARAMETERS spec index spec index of the item new size New size to assign to item RETURN VALUE 20 Successfully adjust size of item 1 Failed to adjust size LIBRARY ZSERVER LIB SEE ALSO sspec_addrootfile 126 TCP IP User s Manual sspec restore int sspec restore void DESCRIPTION Restores the TCP IP servers object list and the TCP IP users list and some user spec ified data if set up with sspec_setsavedata from the file system This does not restore the actual files and variables but only the structures that reference them If the files are stored in flash then the references will still be valid Files in volatile RAM and variables must be rebuilt through other means RETURN VALUE 0 Successfully restored the server_spec and server_auth tables 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_ save sspec_setsavedata Chapter 3 Server Utility Library 127 sspec rmdir int sspec rmdir char name ServerContext context DESCRIPTION Delete a named directory in the FAT filesystem PARAMETERS name Name of directory to delete context Current server context RETURN VALUE 0 OK EPERM Not a filesystem that supports deletion of directories EACCES Not authorized Any other negative values indicate an error SEE ALSO sspec_ delete sspec_mkdir sspec_open 128 TCP IP User s Manual sspec save int sspec_save void DESCRIPTION Saves the servers
97. P_ INLINE the content is to be displayed inline MIME DISP ATTACHMENT the content is only to be displayed if there is some action by the user MIME DISP_FORMDATA the content is form field data or an uploaded file Of these only NONE and FORMDATA are really relevant to HTTP It is only valid to call this when the action code is CGI_ START CGI_DATAor CGI_ END NOTE This is implemented as a macro PARAMETER state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE Content disposition code as documented above LIBRARY HTTP LIB SEE ALSO http _getAction 218 TCP IP User s Manual http getContentLength long http getContentLength HttpState state DESCRIPTION Return the length of data in the current part of a multi part data stream The return value is interpreted differently depending on the action code It is only valid to call this when the action code is CGI_ START CGI_DATA or CGI_END When CGI_ START this returns the value of the ContentLength header for this part or 1 if there was no such header When CGI_DATAor CGI_END it is the total number of bytes that have actually been read and presented to the CGI This increases for each CGI_ DATA call until it repre sents the total content length when action is CGI_ END NOTE This is implemented as a macro PARAMETER state HTTP state pointer as provided in the first parameter to the CGI function
98. P_USERDATA_STZE is defined It is an optional user data area The area is cleared to zero when the structure is initialized otherwise it is not touched Its size must be greater than zero New code should use the htt p_getUserData macro to ob tain a pointer to user defined storage in this structure 4 2 Configuration Macros The following macros are specified in HTTP LIB Unless otherwise noted you can override the default values by defining the macro same name different value before you use http lib HTTP HOMEDIR Specify the home directory for the server This is the root directory to which all URLs are appended The default is which means that all resources are accessible If this is set to say htdocs then an incoming URL of foo bar html gets turned into ht docs foo bar html You can use this to restrict the HTTP server s access to all but a spe cific branch of resources Note the string value for this macro must start and end with a character HTTP DFLTFILE HTTP Specify the default file name to append to the URL if the URL refers to a directory This is only applicable if the URL is or is in a filesystem not the static or dynamic re source tables The default setting is index html The value must not start or end with a character SOCK BUF SIZE This macro is not defined by default If you define it then it specifies the am
99. Password Retype new Password Password Accepted OK If no identifier is stored for the password a lt CR gt must be sent in response to the prompt for the old password NOTE A login name must be stored by a command using con_loginname for a login password to be applicable i e if a password has been stored but no login name new con sole sessions will not prompt for the password or a login name If a login name is applica ble but there is no password new console sessions will prompt for the login name and grant access after a valid name is entered without prompting for a password con_logout This function exits the current console session and begins a new session by entering the initializa tion state of Zconsole A command that uses this function takes no parameters con_mail This function sends e mail to the server specified by con_mail server with the return address specified by set_mail_from A command that uses this function takes one parame ter the destination e mail address If the command is named mail the usage is mail destination where com The first line of the message will be used as the subject and the other lines are the body The body is terminated with a D or Z 0x04 or Ox1A Chapter 11 General Purpose Console 349 con_put This function creates a new file in the file system for use with the HTTP server It works in the fol lowing fashion if the command is called PUT e
100. R LIB SEE ALSO sspec_findname sspec_gettype Chapter 3 Server Utility Library 87 sspec getfileloc long sspec getfileloc int sspec DESCRIPTION Gets the location in memory or in the file system of a file represented by a ServerSpec structure The location of the file is returned as a long even if the file location should be represented by a char for a root file or a FileNum for the file system The return value should be cast to the appropriate type by the user sspec_getfiletype can be used to find the file type PARAMETERS sspec spec index of the file in the resource list RETURN VALUE 20 Success location of the file 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec _getfiletype sspec_getlength 88 TCP IP User s Manual sspec getfiletype word sspec getfiletype int sspec DESCRIPTION Get the type of a file represented by the given spec index PARAMETERS sspec spec index of the file in the resource list that is the index into the array of ServerSpec structures RETURN VALUE SSPEC_ROOTFILE root memory data SSPEC_XMEMFILE xmem data SSPEC_ZMEMFILE compressed xmem data SSPEC_FSFILE FS2 file SSPEC_ERROR failure not a file or invalid handle LIBRARY ZSERVER LIB SEE ALSO sspec_getfileloc sspec_gettype Chapter 3 Server Utility Library 89 sspec getformtitle char sspec getformtitle int form DESCRIPTION Gets the title for an automatically gener
101. RARY ZSERVER LIB SEE ALSO sspec_setrealm 106 TCP IP User s Manual sspec getservermask int sspec getservermask int sspec word servermask DESCRIPTION Gets the server mask for the given spec entry This is the bitmask passed in when the entry is created with the sspec_add functions This function only works for RAM and flash table entries PARAMETERS sspec spec index of the variable servermask Address in which the servermask will be returned RETURN VALUE 0 Success 1 Failure Chapter 3 Server Utility Library 107 sspec gettype word sspec gettype int sspec DESCRIPTION Returns the type SSPEC FILE SSPEC_ VARIABLE etc of the spec entry repre sented by sspec This is a generic type in that SSPEC_FILE is returned for any type SSPEC_ROOTFILE SSPEC_FSFILE etc that has file properties and SSPEC_ VARIABLE is returned for SSPEC_ROOTVAR or SSPEC_XMEMVAR Other types are returned without translation PARAMETERS sspec spec index RETURN VALUE SSPEC_ ERROR Failure SSPEC_ ERROR Success type as described above LIBRARY ZSERVER LIB SEE ALSO sspec_getfiletype sspec_getvartype 108 TCP IP User s Manual sspec getuserid int sspec getuserid int sspec int index DESCRIPTION Returns a userid for the given sspec resource Since a resource can have multiple use rids associated with it index indicates which userid should be returned Note that index sho
102. RY ZSERVER LIB SEE ALSO sspec_setfventrytype Chapter 3 Server Utility Library 93 sspec getfvlen int sspec getfvlen int form int var DESCRIPTION Gets the length of a form variable the maximum length of the string representation of the variable PARAMETERS form spec index of the form var Index into the FormVar array of the variable RETURN VALUE 1 Failure 20 Success length of the variable LIBRARY ZSERVER LIB SEE ALSO sspec_setfvlen 94 TCP IP User s Manual sspec getfvname char sspec getfvname int form int var DESCRIPTION Gets the name of a variable that is displayed in the HTML form table PARAMETERS form spec index of the form var Index into the array of FormVar structures of the variable RETURN VALUE NULL Failure NULL name of the form variable LIBRARY ZSERVER LIB SEE ALSO sspec_setfvname Chapter 3 Server Utility Library 95 sspec getfvnum int sspec getfvnum int form DESCRIPTION Gets the number of variables in a form PARAMETERS form spec index of the form RETURN VALUE 1 Failure 20 Success number of form variables LIBRARY ZSERVER LIB 96 TCP IP User s Manual sspec getfvopt char sspec getfvopt int form int var int option DESCRIPTION Gets the numbered option starting from 0 of the form variable This function is only valid if the form variable has the option list set PARAME
103. S1 this number must be in the range 128 143 so thats reserve blocks can be used to guarantee free space for the backup files Defaults to 128 for FS1 Defaults to 254 for FS2 CON BACKUP FILE2 Same as above except this is for the second backup file Two files are used so that con figuration information is preserved even if the power cycles while configuration data is being saved For FS1 this number must be in the range 128 143 Defaults to 129 for FS1 Defaults to 255 for FS2 CON BACKUP USER BLOCK Defaults to not defined If this is defined then configuration information for the console will be saved to the User block instead of to the flash file system Note that the configu ration is only safe in the case of power failures with a version 3 or higher System ID block CON BUF SIZE Changes the size of the data buffer that is allocated for each I O method If the baud rate or transfer speed is too great for the console to keep up then increasing this value may help avoid dropped characters It is allocated in root data space It defaults to 1024 bytes CON CMD SIZE Changes the size of the command buffer that is allocated for each I O method This limits the length of a command line It is allocated in root data space Defaults to 128 bytes CON CMD DATA SIZE Default is 16 Adjusts the size of the user data area within the state structure so that user commands may preserve arbitrary information across calls The user data area is al
104. SERVER LIB SEE ALSO sspec_getfvreadonly Chapter 3 Server Utility Library 143 sspec setpermissions int sspec setpermissions int sspec char realm word readgroups word writegroups word servermask word method MIMETypeMap mimetype DESCRIPTION Set the permission access control attributes of a resource This only works for RAM table entries For entries in a filesystem use sspec_addrule PARAMETERS sspec spec index realm Realm string or NULL readgroups Mask of user groups who have read access writegroups Mask of user groups who have write access servermask Servers that can access this resource or SERVER_ ANY for all servers method Required authentication method 0 SERVER_AUTH_ BASIC etc mimetype MIME table entry or NULL RETURN VALUE 0 Success lt 0 Failure For example not a RAM spec handle SEE ALSO sspec_checkpermissions sspec_getpermissions sspec_access 144 TCP IP User s Manual sspec setpreformfunction int sspec setpreformfunction int form void fptr DESCRIPTION Sets a user function that will be called just before form generation The user function is not called when the form is being generated because of errors in the form input The user function must have the following prototype void userfunction int form The function may not use the form parameter but it is useful if the same user function is used for multiple forms PARAMETERS form spec in
105. TERS form spec index of the form var Index into the array of FormVar structures of the variable option Index of the form variable option RETURN VALUE NULL Failure NULL Success form variable option LIBRARY ZSERVER LIB SEE ALSO sspec_setfvoptlist sspec_getfvoptlistlen Chapter 3 Server Utility Library 97 sspec getfvoptlistlen int sspec getfvoptlistlen int form int var DESCRIPTION Gets the length of the options list of the form variable This function is only valid if the form variable has the option list set PARAMETERS form spec index of the form var Index into the FormVar array of the variable RETURN VALUE 1 Failure gt 0 Success length of the options list LIBRARY ZSERVER LIB SEE ALSO sspec_getfvopt sspec_setfvoptlist 98 TCP IP User s Manual sspec getfvreadonly int sspec getfvreadonly int form int var DESCRIPTION Checks if a form variable is read only PARAMETERS form spec index of the form var Index into the FormVar array of the variable RETURN VALUE 0 Not read only 1 Read only 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_setfvreadonly Chapter 3 Server Utility Library 99 sspec getfvspec int sspec getfvspec int form int var DESCRIPTION Gets the server_spec index of a variable in a form PARAMETERS form server spec index of the form var Index into the array of FormVar structures of the varia
106. This is described in detail in the Dynamic C Module document titled RabbitWeb Web Enabling Your Application for the purposes of this section please just remember that it is easy to do Chapter 2 Web Enabling Your Application 21 2 7 A Full Featured Application The previous examples have relied on ximport to store files in the program flash This is limit ing in terms of storage capacity and does not allow for dynamic file updates Adding the ability to store files in a filesystem that is located somewhere besides the program flash is of high value because it adds storage capacity and allows for dynamic updates Application Compile Time Run Time Main Application CGI Initialization Initialization Loop Specifics I O _ Functions web Variables Metadata Requests Context Zserver TCP IP i z Resource Manager E Virtual File System Resources Static Dynamic Resource Resource Table Table PEE S ses sone Battery a Fregan Backed RAM Figure 2 5 Components of a full featured web enabled application As mentioned previously Zserver implements a virtual filesystem that can be used by an applica tion for a clean consistent interface to the various available methods of resource organization An application can also bypass the resource manager and access a filesystem directly Note that there is no arrow in the diagram showing this line of communication 22 TCP IP
107. This is implemented as a macro PARAMETER state HTTP state pointer as provided in the first parameter to the CGI function val New value for the primary state variable RETURN VALUE Returns the new value that is val LIBRARY HTTP LIB SEE ALSO http _getAction 246 TCP IP User s Manual http shutdown int http shutdown int graceful DESCRIPTION Shut down the http daemon Use http_init to restart PARAMETER If non zero current connections are allowed to terminate normally Otherwise any open connections are reset RETURN VALUE 0 LIBRARY HTTP LIB SEE ALSO http_handler http_init http_status Chapter 4 HTTP Server 247 http skipCGI int http skipCGI HttpState state DESCRIPTION Indicate to the HTTP server that the CGI has finished processing this part of a multi part data stream The server reads and discards data from the stream until the next part is found or the epilog When the next part is found the server continues calling the CGI function as before PARAMETERS state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE 0 LIBRARY HTTP LIB SEE ALSO http _getAction http _abortCGI http _switchcGI http _finishCGI http_write 248 TCP IP User s Manual http sock bytesready int http sock bytesready HttpState state DESCRIPTION HTTP wrapper function for sock_bytesready This function may be used by CGI
108. User s Manual Looking at the bottom of the diagram in Figure 2 5 you can see that there are some additional hardware requirements when using FAT or FS2 The FAT needs a serial flash and FS2 needs a sec ond flash or battery backed RAM The sample program is now expanded to use a FAT filesystem and has the ability to upload files to it As before the changes are in boldface define FAT USE FORWARDSLASH define FAT BLOCK define USE HTTP UPLOAD define TCPCONFIG 1 define USE RABBITWEB 1 define USE HTTP BASIC AUTHENTICATION 1 use Sflash fat 1lib use fat 1lib use dcrtcp lib use http 1lib web groups monitor group admin group ximport my _app zhtml my_app zhtml SSPEC MIMETABLE START SSPEC MIME FUNC html text html zhtml_handler SSPEC MIME cgi SSPEC MIMETABLE END SSPEC RESOURCETABLE START SSPEC_ RESOURCE XMEMFILE index html my_app_zhtml SSPEC RESOURCE CGI upload cgi http defaultCGI SSPEC RESOURCETABLE END int io state web io state auth basic groups monitor group ro admin_ group void my_io polling void void main int rc sspec addrule index html Pet admin _group monitor group 0 SERVER_HTTP SERVER AUTH BASIC NULL sauth_ setusermask sauth_ adduser admin dog SERVER ANY admin group NULL sauth setusermask sauth_adduser monitor cat SERVER ANY monitor group NULL re sspec automount SSPEC MOUNT ANY NULL NULL NULL if rc printf Failed
109. User s Manual This is only useful in conjunc tion with FS2 LIB This should be called once before console _init Care should be taken that enough space is available in this logical extent for the configuration files See con_backup_bytes for more information PARAMETER backup1x LX number to use for backup LIBRARY zconsole lib SEE ALSO con_set_files_ 1x con_backup_bytes con set files 1x void con set files 1x FSLXnum fileslx DESCRIPTION Sets the logical extent LX that will be used to store files For more information on the file system see the Dynamic C User s Manual This is only useful in conjunction with FS2 L1B This should be called once before console init PARAMETER fileslx LX number to use for files LIBRARY zconsole lib SEE ALSO con_set_backup_1x Chapter 11 General Purpose Console 363 con set user idle void con_set_user idle void funcptr DESCRIPTION Sets a user defined function that will be called when the console for a particular I O channel is idle The user defined function should take an argument of type ConsoleState LIBRARY zconsole lib SEE ALSO con_set_user_ timeout con set timeout unsigned long con set timeout unsigned int seconds DESCRIPTION Returns the value that MS_TIMER should have when the number of seconds given have elapsed LIBRARY zconsole lib SEE ALSO con_chk_timeout 364 TCP IP User s Manual c
110. Y admin group NULL This is a nested function call sauth_adduser is called first to add a user called admin with password dog This user is visible to all servers SERVER_ANY The result of this function call is a userID handle which is the first parameter to sauth_setusermask This function explicitly assigns a group mask to the user You can omit this call however the default method of assigning group masks is designed to be backward compatible with old versions of the library and may not be what you want when using new fea tures You should always use the sauth_setusermask function for each user ID In this example we have added access control to the code We do not need to change the ZHTML script although in reality you would probably want to Using the script unchanged when the user tries to retrieve index htm1 the browser will prompt for a userid and password If one of the valid users is entered then the page will be displayed Otherwise the browser will print an error message saying that access was denied 20 TCP IP User s Manual Unfortunately as written above the sample will not allow us to test the distinction between the two users regarding the ability to modify the web variable We have shown how to add access control but not how to actually specify a web form that allows the user to update the variable It turns out that adding a form is not difficult A modified script file is shown bel
111. Z WWORLD Dynamic C TCP IP User s Manual Volume 2 050223 019 0144 B This manual or an even more up to date revision is available for free download at the Z World website www zworld com Dynamic C TCP IP User s Manual Volume 2 Part Number 019 0144 B Printed in U S A 2005 Z World Inc All rights reserved Z World reserves the right to make changes and improvements to its products without providing notice Trademarks Dynamic C is a registered trademark of Z World Inc Windows is a registered trademark of Microsoft Corporation Z World Inc 2900 Spafford Street Davis California 95616 6800 USA Telephone 530 757 3737 Fax 530 757 3792 or 530 753 5141 www zworld com ii Dynamic C TCP IP User s Manual Table of Contents 1 SnireductiOn cce eee ee oe eek 1 sspec_addform cesses 60 r D sspes addis iie raene 6l 2 Web Enabling Your Application 3 sspec_addfunction c seseceeeceeseees 62 2 1 Designing Your Application 3 nae TA SS IRAT OE EESE ORS SUE A 2 2 The Smallest Web Server in the WWW 4 sspec_addrule NE 65 2 3 Web Server Architecture eee 6 sspec_adduser ssesssesesseeeresseeeenees Application Block 7 E E EAE a HTTP Block 8 ee leot a Ee Poem o sspec_addxmMemVar seese HTTP Block Subcomponents 9 SSPOC_AliASSPEC 0 eeeeeeeeeeeteeeeteeeeeeees 71 Zserver Block 10 SSPEC_AULOMOUNL sssr 72 ERE SS pec Cder einir S 74 Ar rA Toget or a Tey
112. ZSERVER LIB SEE ALSO sspec_getfvname 140 TCP IP User s Manual sspec setfvoptlist int sspec setfvoptlist int form int var char list int listlen DESCRIPTION Sets an enumerated list of possible values for a string variable PARAMETERS form spec index of the form var Index into the FormVar array of the variable list Atray of string values that the variable can assume listlen Length of the array RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_getfvopt sspec_getfvoptlistlen sspec_setfvfloatrange sspec_setfvrange Chapter 3 Server Utility Library 141 sspec setfvrange int sspec setfvrange int form int var long low long high DESCRIPTION Sets the range of an integer variable PARAMETERS form spec index of the form var Index into the FormVar array of the variable low Minimum value of the variable high Maximum value of the variable RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_setfvfloatrange sspec_setfvoptlist 142 TCP IP User s Manual sspec setfvreadonly int sspec setfvreadonly int form int var int readonly DESCRIPTION Sets the form variable to be read only PARAMETERS form spec index of the form var Index into the FormVar array of the variable readonly O for read write this is the default 1 for read only RETURN VALUE 0 Success 1 Failure LIBRARY Z
113. Zserver lib Starting with Dynamic C 8 50 enhanced support is provided for HTML forms with the purchase of the Dynamic C RabbitWeb Module This module provides an easy to develop web interface for your embedded device and allows for complete flexibility in form layout See the document titled RabbitWeb To Web Enable Embedded Applications for more information on this enhanced HTTP server In older versions of Dynamic C it was necessary to explicitly create the static resource table by doing something like this const HttpSpec http flashspec in your main application code filling in the entries of course Starting with Dynamic C 8 50 there is new recommended syntax for creating these resources using the SSPEC_RESOURCETABLE series of macros This new method is recommended for maintain ing future compatibility For more information see Section 3 2 5 3 Static Resource Table Chapter 3 Server Utility Library 33 3 1 2 1 ServerSpec Fields The fields in each resource table static or dynamic are usually manipulated via Zserver functions or by using the SSPEC_RESOURCE macros The field descriptions below are for reference only type This field tells the server if the entry is a file variable or function SSPEC_ FILE SSPEC VARIABLE SSPEC_ FUNCTION etc name This field contains the resource name as a null terminated string data Location of data when FILE is the type of data or maximum number of variables
114. a FORMSpec 0 value 0 0 FORMSpec 1 value 0 0 state gt p state gt buffer state gt substate break 174 TCP IP User s Manual case 3 parse the POST information if parse post state sprintf state gt buffer lt p gt Username s lt p gt r n lt p gt Email s lt p gt r n FORMSpec 0 value FORMSpec 1 value state gt length strlen state gt buffer state gt substate break case 4 strcpy state gt buffer lt p gt Go lt a href gt shome lt a gt lt body gt lt html gt r n state gt length strlen state gt buffer state gt substate break default state gt substate 0 return 1 return o0 Chapter 4 HTTP Server 175 4 5 4 HTML Forms Using Zserver lib In this section we will step through a sample program Samples tcpip http forml c that uses HTML forms Through this step by step explanation the method of using the functions in zserver lib will become clear As of Dynamic C 8 50 you have the option of using the RabbitWeb server with its easier to use interface and completely flexible ZHTML page layout capabilities For more information see the document titled RabbitWeb To Web Enable Embed ded Applications available on our website Defining FORM_ERROR_BUF is required in order to use the HTML form functionality in Zserver 1ib The value represents the number of bytes that will be reserved in root memory for the buffer
115. abbitWeb is available as a Dynamic C add on module starting with Dynamic C 8 50 If you do not have RabbitWeb you can use SSI instead which is described in Section 4 5 2 1 SSI Feature This example illustrated in Figure 2 3 assumes that you have Rab bitWeb Chapter 2 Web Enabling Your Application 13 The document titled RabbitWeb To Web Enable Embedded Applications describes RabbitWeb and the scripting language ZHTML in detail The following example is a simplification of the web c sample program in Samples tcpip rabbitweb define TCPCONFIG 1 define USE RABBITWEB 1 use dcrtcp lib use http 1lib ximport my app zhtml my app zhtml SSPEC MIMETABLE START SSPEC MIME FUNC html text html zhtml_handler SSPEC MIMETABLE END SSPEC RESOURCETABLE START SSPEC RESOURCE XMEMFILE index html my app zhtm1 SSPEC RESOURCETABLE END int io state web io state void my io polling void void main sock_init http_init for my io polling http handler void my io polling The differences between the above code and the toy example in the previous section are in bold face All the differences relate to the use of RabbitWeb The first addition is a define of USE _RABBITWEB This is necessary in order to include the necessary library code io state read that _ io device Next there is a modification to the MIME table The SSPEC_MIME_FUNC macro defines a
116. able before being added to the form The first parameter is the name to be given to the variable the second is the address of the variable the third is the type of variable this can be INT8 INT16 INT32 FLOAT32 or PTR16 the fourth is a printf style format specifier that indicates how the variable should be printed and the fifth is the server for which this variable is accessible The return value is the handle of the variable in the resource table var sspec addvariable temphi amp temphi INT16 d SERVER HTTP Ng The following line adds a variable to a form The first parameter is the index of the form to add the variable to the return value of sspec_addform and the second parameter is the index of the variable the return value of sspec_addvariable The return value is the index of the variable within the developer declared FormVar array myform var sspec_addfv form var This function sets the name of a form variable that will be displayed in the first column of the form table If this name is not set it defaults to the name for the variable in the resource table temphi in this case The first parameter is the form in which the variable is located the second parameter is the variable index within the form and the third parameter is the name for the form variable sspec_setfvname form var High Temp This function sets the description of the form variable wh
117. ables provided that a filesystem FAT or FS2 is used However it is convenient to have at least a few entries in the dynamic table and it is mandatory to have entries in either or both the static and dynamic tables if CGI functions are used When using the HTTP upload facility you will need at least one CGI function to be defined and probably another entry for the initial form The resource table may be defined as follows SSPEC RESOURCETABLE START SSPEC RESOURCE XMEMFILE index html index html SSPEC RESOURCE CGI upload cgi my CGT SSPEC RESOURCETABLE END This defines a static resource table with two entries The first is a static web page for the form index html and the second points to the CGI that will be used to process the uploaded data Important use SSPEC_RESOURCE_ CGI not SSPEC_RESOURCE_ FUNCTION this defines the CGI as new style SSPEC_RESOURCE XMEMFILE specifies a file that has been imported in the server s flash memory using the ximport directive For example ximport samples tcpip http pages upload html index html index html isa placeholder a long int for the start of the file This is mentioned in the resource table entry so that the server knows where to get it The second entry above specifies a new style CGI function which has been the subject of the preceding sections You must use the SSPEC_ RESOURCE CGI macro to specify this type of CGI The URL string parameter is whatever is mentioned
118. al error occurred LIBRARY VSERIAL LIB telnet close void telnet close void DESCRIPTION Terminates any connections currently open and shuts down the daemon LIBRARY VSERIAL LIB 340 TCP IP User s Manual 10 2 3 An Example Telnet Server The following code implements a telnet server It listens on well known port 23 for a connection request Data is passed transparently via serial port C define MY_IP ADDRESS 10 10 6 105 define MY NETMASK 255 255 255 0 define MY GATEWAY 10 10 6 19 define MY NAMESERVER 10 10 6 19 define SERIAL PORT SPEED 115200 Setserial port speed undef TELNET COOKED This is a raw data port memmap xmem tuse Ydertep lib use vserial lib define SERVER_PORT 0 Defaults to port 23 main sock init Initialize stack telnet _init TELNET LISTEN 0 SERVER_PORT Initialize server while telnet tick Run server this is non blocking continue telnet close Error close telnet connection Chapter 10 Telnet 341 10 2 4 An Example Telnet Client This sample code implements a client that can connect to the above telnet server define MY_IP ADDRESS 10 10 6 106 define MY NETMASK 255 255 255 0 define MY GATEWAY 10 10 6 19 define MY NAMESERVER 10 10 6 19 define SERIAL PORT SPEED 115200 Must match server undef TELNET COOKED memmap xmem tuse MGlewieCjo iip use vserial lib define SERVER_PORT 0 Defaults to p
119. ally when sequential access is all that is required This function will NOT work for compressed xmem files or DOS FAT files PARAMETERS sspec spec index buffer The buffer to put the file contents into offset The offset from the start of the file in bytes at which copying should begin len The number of bytes to copy RETURN VALUE 1 Failure 20 Success number of bytes copied LIBRARY ZSERVER LIB SEE ALSO sspec_getlength sspec_getfileloc Chapter 3 Server Utility Library 121 sspec readvariable int sspec readvariable int sspec char buffer DESCRIPTION Formats the variable associated with the specified ServerSpec structure and puts a NULL terminated string representation of it in buffer The macro SSPEC_ XMEMVARLEN default is 20 defines the size of the stack allocated buffer when reading a variable in xmem PARAMETERS sspec spec index buffer The buffer in which to put the variable RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_getvaraddr 122 TCP IP User s Manual sspec remove int sspec remove int sspec DESCRIPTION Removes a spec entry by marking it unused In the case of files note that this function does not actually remove the file only the reference to the file in the spec structure This only works for RAM table entries PARAMETERS sspec spec index RETURN VALUE 0 Success 1 Failure i e the index is already unus
120. ameter ETHO ETH1 PPPO PPP1 PPP2 etc to display the interface spe cific configuration for the specified interface If the optional parameter is missing the current con sole configuration for all valid interfaces is displayed Chapter 11 General Purpose Console 351 11 4 1 2 Custom Zconsole Commands Developers are not limited to the default commands A custom command is easy to add to Zcon sole simply create an entry for itin console commands The three fields of this entry were described in Section 11 3 1 The first field is the name of the command The second field is the function that implements the command This function must follow this prototype int function_name ConsoleState state j The parameter passed to the function is a structure of type ConsoleState Some of the fields in this structure must be manipulated by your custom command function other fields are used by Zconsole 1ib and must not be changed by the your program typedef struct int console number ConsoleIO conio int state int laststate char command CON CMD SIZE char cmdptr char buffer CON BUF SIZE Use for reading in data char bufferend Use for reading in data ConsoleCommand cmdspec int sawcr int sawesc int echo Check if echo is enabled or change it int substate unsigned int error int numparams Number of parameters on command line int commandparams Number of commands issued on cmd line cha
121. ameter to all these macros is the resource name This usually starts with a for files but not for variables The string length should be less than or equal to SSPEC MAXNAME Chapter 3 Server Utility Library 43 The other parameters depend on the resource type being created ROOTFILE addr root memory address of first byte of file Len length of file 0 32767 XMEMFILE addr longword physical address of the length word of the file The length word 4 bytes is followed by the first byte of data ZMEMFILE as for XMEMF ILE except the file is compressed and imported using Zimport instead of ximport FSFILE fnum FS2 file number of file 1 255 ROOTVAR addr root memory address of data type type of data as documented with sspec_addvariable format char format as used by printf For example d for a decimal number XMEMVAR as for ROOTVAR except the address is a longword physical address FUNCTION or CGI addr address of C function Note that a maximum of 511 static resource table entries can be defined 3 3 File Compression Support Dynamic C 8 50 introduces file compression support The sample program samples tcpip http zimport c demonstrates how to use this functionality This sam ple is oriented towards the HTTP server however under the covers HTTP is relying on Zserver to perform the compressed file handling In the sample program notice that the statement us
122. amic C 8 50 this is easier than it used to be If there is no serial flash the FAT filesystem isn t available but if there is a second flash or some battery backed RAM FS2 is The following diagram shows the components that are used in this case Note that even though both the second flash and the battery backed RAM are high lighted an application can use either or both Application Compile Time Run Time Main Application CGI Initialization Initialization Loop Specifics I Q _ Functions e Variables Sa HTTP Requests Resources Context Zserver TCP IP Resource Manager _ Metadata Ree es Virtual File Virtual File System Dynamic Resource Figure 2 6 Components of a full featured web enabled application 26 TCP IP User s Manual The sample program is now modified to use the FS2 filesystem It still has the ability to upload files to the filesystem As before the changes are in boldface define USE_HTTP_ UPLOAD define TCPCONFIG 1 define USE HTTP BASIC AUTHENTICATION 1 use fs2 1ib define admin group 0x0001 define monitor group 0x0002 use dcrtcp lib use http lib ximport my app shtml my app shtml SSPEC MIMETABLE START SSPEC MIME FUNC ssi text html shtml handler SSPEC MIME cgi eat SSPEC MIMETABLE END int io state SSPEC RESOURCETABLE START SSPEC RESOURCE ROOTVAR io state amp io state INT16 SSPEC_ RESOURCE XMEMFILE index htm
123. andler 268 TCP IP User s Manual ftp client tick int ftp client tick void DESCRIPTION Tick function to run the FTP daemon Must be called periodically The return codes are not very specific You can call ftp last code to get the integer value of the last FTP message received from the server See RFC959 for details For example code 530 means that the client was not logged in to the server RETURN VALUE FTPC AGAIN 0 still pending call again FTPC OK 1 success file transfer complete FTPC_ERROR 2 failure call ftp _last_code for more details FTPC NOHOST 3 failure Couldn t connect to remote host FTPC NOBUF 4 failure no buffer or data handler FTPC TIMEOUT 5 warning Timed out on close data may or may not be OK FTPC_DHERROR 6 error Data handler error in FTPDH_END operation FTPC CANCELLED 7 FTP control socket was aborted reset by the server LIBRARY FTP CLIENT LIB SEE ALSO ftp client setup ftp client filesize ftp client xfer ftp_last_code Chapter 5 FTP Client 269 ftp client filesize int ftp client filesize void DESCRIPTION Returns the byte count of data transferred This function is deprecated in favor of ftp_client_xfer which returns a long value If the number of bytes transferred was over 32767 then this function returns 32767 which may be misleading RETURN VALUE Size in bytes LIBRARY FTP CLIENT LIB SEE ALSO ftp client se
124. arameter for write access CGIs themselves do not have the concept of writability that would imply the ability to change the CGI function so this is always zero for a CGI SERVER_HTTP this specifies the server that can use the CGI function CGIs are currently only usable by the HTTP server thus there is no other sensible choice for this parameter SERVER_AUTH_ BASIC this specifies the required minimum authentication method BASIC means that a simple plain text userid and password will be required A better choice is SERVER_AUTH_ DIGEST since that does not reveal the password to anyone listening in on the conversation however older web browsers do not support this Next the file system needs to be protected Usually you do not want the entire file system to be writable even to the privileged group members To establish this sort of protection you need to set up a rule based access control This is done using the SSPEC_RULETABLE method or equiva lent runtime control define SSPEC FLASHRULES use http lib SSPEC_RULETABLE START SSPEC_MM RULE A new newPages OxXFFFF ADMIN GROUP SERVER_HTTP SERVER AUTH NONE NULL SSPEC_RULETABLE END The SSPEC_FLASHRULES macro must be defined before you use http lib The rule table has one entry in this example The parameters to this entry are e A new this is the string prefix of all file names to which this rule applies In this example everyth
125. associated socket to BINARY RETURN VALUE None LIBRARY HTTP LIB Chapter 4 HTTP Server 253 http sock tbleft long http sock tbleft HttpState state DESCRIPTION HTTP wrapper function for sock_tbleft This function may be used by CGI ap plications to determine how much space is left in the HTTP socket s transmit buffer PARAMETERS state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE Number of bytes of free space remaining in the transmit buffer LIBRARY HTTP LIB 254 TCP IP User s Manual http _ sock write int http sock write HttpState state byte dp int len DESCRIPTION HTTP wrapper function for blocking writes This function can be used to write data from a root buffer to a socket associated with a particular HTTP server This function is intended for use in CGI applications PARAMETERS state HTTP state pointer as provided in the first parameter to the CGI function dp pointer to buffer containing data to be written len maximum number of bytes to write to the socket RETURN VALUE Number of bytes of written or 1 if there was an error LIBRARY HTTP LIB Chapter 4 HTTP Server 255 http sock xfastread int http sock xfastread HttpState state long dp long len DESCRIPTION HTTP wrapper function for sock_fastxread that is for non blocking reads xmem This function can be used to read data from a socket associated with a part
126. ast 180 bytes for CGI functionality HTTP MAX COND Support for conditional SSI error feedback etc It defaults to 4 This is the maximum number of state variables that may be accessed using the http_getCond or http setCond macros HTTP MAX NONCES This macro is used when USE_HTTP_ DIGEST AUTHENTICATION is set to one Defined to 5 by default it specifies the number of nonces the HTTP server will allow as valid at any one time This value should be somewhat larger than the maximum num ber of clients expected to be accessing the server simultaneously Otherwise perfor mance could suffer as clients are forced to retry authorization in order to acquire a fresh nonce HTTP MAXSERVERS This is the maximum number of HTTP servers listening on port 80 The default is 2 You may increase this value to the maximum number of independent entities on your page For example for a Web page with four pictures two of which are the same set HTTP _MAXSERVERS to 4 one for the page one for the duplicate images and one for each of the other two images By default each server takes 2500 bytes of RAM This RAM usage can be changed by the macro SOCK BUF SIZE or tcp _MaxBufSize which is deprecated as of Dynamic C ver 6 57 Another option is to use the tcp _reserveport function and a smaller number of sockets HTTP MAXURL This macro defines the maximum incoming URL This could be important if someone is allowing GET requests with a large number
127. ated form PARAMETERS form server spec index of the form RETURN VALUE NULL Failure NULL Success title string LIBRARY ZSERVER LIB SEE ALSO sspec_setformtitle 90 TCP IP User s Manual sspec getfunction void sspec getfunction int sspec DESCRIPTION Returns a pointer to the function represented by the sspec index The entry must have been created asa SSPEC_ FUNCTION or asa SSPEC_CGI PARAMETERS sspec spec index RETURN VALUE NULL Failure NULL Success pointer to requested function LIBRARY ZSERVER LIB SEE ALSO sspec_addfunction Chapter 3 Server Utility Library 91 sspec getfvdesc char sspec getfvdesc int form int var DESCRIPTION Gets the description of a variable that is displayed in the HTML form table PARAMETERS form spec index of the form var Index into the FormVar array of the variable RETURN VALUE NULL Failure NULL Success description string LIBRARY ZSERVER LIB SEE ALSO sspec_setfvdesc 92 TCP IP User s Manual sspec getfventrytype int sspec getfventrytype int form int var DESCRIPTION Gets the type of form entry element that should be used for the given variable PARAMETERS form spec index of the form var Index into the FormVar array of the variable RETURN VALUE 1 Failure Type of form entry element on success HTML_FORM_TEXT is a text box HTML_FORM_PULLDOWN is a pull down menu LIBRA
128. ble RETURN VALUE 1 Failure 20 Success index of the form variable in the resource list LIBRARY ZSERVER LIB SEE ALSO sspec_addfv 100 TCP IP User s Manual sspec getlength long sspec getlength int sspec DESCRIPTION Gets the length of the file associated with the specified ServerSpec structure Get the length of the file specified by the sspec index Note that compressed files zimport return 1 because their expanded length is not known until they are pro cessed PARAMETERS sspec spec index of file in resource list RETURN VALUE 1 Failure compressed file or other type whose effective length is not known 20 Success length of the file in bytes LIBRARY ZSERVER LIB SEE ALSO sspec_readfile sspec_getfileloc Chapter 3 Server Utility Library 101 sspec getMIMEtype MIMETypeMap sspec getMIMEtype char name ServerContext context DESCRIPTION Return the MIME type information for a specified resource name in the given server context Note that the available MIME types are set up by defining a global variable or con stant table using the definition for example const MIMETypeMap http types Html text html NULL gif image gif NULL The name http_types is required for backward compatibility even though servers other than HTTP can make use of MIME types When searching for the appropriate type the rule table is consulted first On
129. ble web server It does nothing but show Hello WWW on the browser There are two files needed for this The first is the Dynamic C code to be loaded to the target board which must support TCP IP The second is the web page content itself written in a syntax known as HTML HyperText Markup Language The second file is effectively included in the program using the ximport directive toy_http c define TCPCONFIG 1 use dcrtcp 1lib use http 1lib ximport hellowww html hellowww_html SSPEC MIMETABLE START SSPEC MIME html text html SSPEC MIMETABLE END SSPEC RESOURCETABLE START SSPEC_ RESOURCE XMEMFILE hellowww html hellowww_htm1 SSPEC RESOURCETABLE END void main sock init http init for http handler The second file named he 1 lowww html is coded as follows lt HTML gt lt HEAD gt lt TITLE gt Hello WWW lt TITLE gt lt HEAD gt lt BODY gt lt H1 gt Hello WWW lt H1 gt lt BODY gt lt HTML gt 4 TCP IP User s Manual That s all there is to it However there is actually a lot of activity going on beneath the covers For a Start the use dcrtcp lib directive and the TCPCONFIG macro definition bring in the TCP IP networking suite and configure it Unless you have a private test network you probably have to modify the default setting how to do that is beyond the scope of this chapter it is described in volume 1 of the manual The use
130. c and Post2 cinthe Samples Tcpip Http folder show how to do this The HTTP POST command can put any kind of data onto the network There are many encoding schemes currently used but we will only look at URL encoded data in this document Other encoding schemes can be handled in a similar manner 172 TCP IP User s Manual 4 5 3 3 URL Encoded Data URL encoded data is of the form namel valuel amp name2 value2 and is similar to the CGI form submission type passed in normal URLs This has to be parsed to name value pairs The rest of this section details an extensible way to do this This initializes two possible HTML form entries to be received and a place to store the results define MAX FORMSIZE 64 typedef struct char name char value MAX FORMSIZE FORMType FORMType FORMSpec 2 void init_forms void FORMSpec 0 name user_name FORMSpec 1 name user email Reading amp Storing URL encoded Data parse_post is called from the CGI function submit to read URL encoded data off the network It calls http_scanpost to store the data in FORMSpec These code snip pets are from Samples tcpip http post c int parse post HttpState state auto int retval auto int i retval sock aread amp state gt s state gt p state gt content length lt HTTP MAXBUFFER 1 int state gt content length HTTP MAXBUFFER 1 if retval lt 0 return 1 state gt s
131. c_ save sspec_ restore Chapter 3 Server Utility Library 147 sspec setuser int sspec setuser int sspec int userid DESCRIPTION Set the read permission mask of a spec entry usually a file The permissions for this resource are set to readable only by the group s which this user is a member of Write access is set to none This function is deprecated in Dynamic C 8 50 Use sspec_setpermissions instead PARAMETERS sspec spec index this must refer to a RAM resource userid user index RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO sauth_adduser sspec_getusername sspec_setpermissions 148 TCP IP User s Manual sspec stat int sspec stat char name ServerContext context SSpecStat s DESCRIPTION Get information about a resource by name The name may refer to a flash or ram spec entry or may be the name of a file in a filesystem See sspec_open fora more detailed description of the name and context parameters PARAMETERS name Resource name as a null terminated string This name is assumed to be relative to context gt cwd if it does not begin with a character Otherwise the name is assumed to be relative to context gt rootdir context Additional context information The ServerContext structure is set up by the caller s Returned data This is a pointer to the following structure which will be filled in on return typedef struct
132. ccess control The next two ques tions relate to the HTTP upload facility The last two questions concern the overall design of your application in particular a large application may necessitate more storage than is usually available for a given Z World product and may require a sophisticated filesystem to manage the large num ber of resources Since the terms small medium and large are rather vague we shall define them by example A small application would be limited to less than 10 different web pages and up to about 30 different controls buttons to press dials to twiddle options to select etc A large application may have upwards of 100 pages and more than 10KB of configurable data A medium application sits as you might expect near the middle of these Note that we are not considering the size of the application other than the web interface part For example you may have a sophisticated G code interpreter and motion control system where the web interface is limited to simply enabling disabling the actuators and showing an error log to maintenance personnel For the purposes of our discussion this would be a small application The next section describes a smaller than small application that is a toy which we use to show the bare essentials of a web enabled application 2 2 The Smallest Web Server in the WWW Before moving on to real applications the following sample code shows how to create the sim plest possi
133. cess permissions tests on that basis If access is denied then the browser will prompt the user for a real user name and password and the request will be re tried You do not always need to define an anonymous user to HTTP But it is required if you have some resource which is say protected for write access but you want any user to be able to retrieve the resource without requiring a user name password NOTE This function is non reentrant It sets a global variable which is accessed by all HTTP server instances For this reason you should call this function once only before starting to call http handler PARAMETER uid The userID to use as the anonymous user This should have been defined using sauth_adduser Pass 1 to set no anony mous user In this case only resources which are completely free of any access controls will be accessible to users who do not pro vide credentials RETURN VALUE Same as the uid parameter except 1 if uid invalid LIBRARY HTTP LIB SEE ALSO sauth_adduser ftp set _anonymous sauth_setusermask Chapter 4 HTTP Server 241 http setauthentication int http setauthentication int auth DESCRIPTION Sets the type of authentication to be used globally by the HTTP server By default this is set to the strongest available type of authentication available in order of weakest to strongest HTTP NO AUTH HTTP BASIC AUTH HTTP DIGEST AUTH This function returns the type of authentication tha
134. character We are using the convention that if the field starts with a slash it is the name of a local file to be overwritten with the following data Note that the field names are controlled by the server via the NAMEZ parameters in the INPUT fields We can choose any naming convention desired in this case using an initial slash seems to make sense for file destinations Now let s fill in what happens when there is a file to save In most cases when writing or reading a file it is necessary to open the file When a file is open it can be read and or written Finally it is closed All this implies that some sort of state needs to be maintained so that we can refer to the correct open file It would be very easy if all the data was presented at once to the CGI so that it could open write and close the file in one fell swoop Unfortunately that cannot happen since the data is not yet available on the CGI_ START call The CGI has no choice than to return to the HTTP server after doing whatever it can in the CGI_START state The solution to this problem is that the CGI opens the file on the CGI_ START call and stores the open file handle somewhere where it can be retrieved on the next CGI_DATA or CGI_ END call The recommended method for accomplishing this is to save the handle back with the server You can use the http _setCond and http getCond functions to do this The HTTP server maintains a set of so called cond variable
135. check the cond variable just set to make sure it has a valid value The else clause is added so that if the part is not a file to upload the rest of the data for this part is ignored This is convenient since we don t want to get called with CGI_ DATA or CGI_ END if this is not a file Ifhttp skipCGI is called then the next action code will be either CGI_START if there is another part or CGI_ EOF if there were none Note that we are also calling http _skipCGI in the case that the file could not be opened Action Code CGI_DATA Let s now turn to saving the data For this we make use of the CGI_ DATA action code int handle case CGI DATA handle http _getCond s COND HANDLE sspec write handle http getData s http getDataLength s j break First the open file handle is retrieved from the cond variable This works because the HTTP server does not touch these variables between calls The only time the server changes the cond variables is at the start of a completely new form submission in which case they are usually set to zero But don t depend on them being zero since a form submission can sometimes contain syntax that sets them to non default values You can rely on http_getState returning zero on the very first call thereafter it is not touched but can be manipulated by the CGI calling the function http _setState 190 TCP IP User s Manual Having retrieved the open file handle you didn t sa
136. client indicating whether or not the submission was acceptable If you start reading the following and start feeling somewhat overwhelmed please be aware that there is a default CGI function in the HTTP library that is very useful The default CGI called http defaultCGI automatically saves uploaded files into the filesystem If that is all you need to do then you do not need to fully comprehend this section on first reading Note that all of this section is describing new style CGIs Old style CGIs are covered in Section 4 5 3 CGI Syntax All CGI functions are C functions with the following prototype int my CGI HttpState s The HttpState parameter is a pointer to the internal state variables of the HTTP server instance that is handling the current request You can have one or more server instances If there is more than one the same CGI may be invoked at the same time for more than one client if both happen to press the submit button at about the same time Thus it is important to write the CGI function so that it is re entrant This basically means that the function should not update global or static variables The CGI should not attempt to modify directly any of the fields in the HttpState structure otherwise the server may become inoperable API Functions The HTTP library provides a set of API functions that can be called safely from the CGI The list of safe functions is in the index under Function Reference CGI
137. ction This call back will be used to provide you the incoming data This function is usually called once 2 pop3_getmail is called to start the e mail being received and to provide the library with e mail account information 3 pop3_tick is called as long as it returns POP_ PENDING to actually run the library The library will call the function you provided pop3_ init several times to give you the e mail 9 3 Call Back Function There are two types of call back functions which are described here 9 3 1 Normal call back When not using POP_PARSE_ EXTRA you need to provide a function with the following proto type int storemail int number char buf int size The parameter number is the number of the e mail being transferred usually 1 for the first 2 for the second but not necessarily The numbers are only guaranteed to be unique between all e mails transferred The buf parameter is the text buffer containing one line of the incoming e mail This must be copied out immediately as the buffer will be different when the next line comes in and your call back is called again size is the number of bytes in buf The sample program Samples tcpip pop3 pop c provides an example of this style of call back 9 3 2 POP_PARSE_EXTRA call back If POP_ PARSE EXTRA is defined you need to provide a call back function with the following prototype int storemail int number char to char from char subject char body int size
138. d error information is written into the error buffer If this function is used directly the developer must process errors PARAMETERS form server_spec index of the form i e location in TCP IP serv ers object list state The HTTP server with which to parse the POSTed data RETURN VALUE 0 There is more processing to do 1 Form processing has been completed LIBRARY HTTP LIB 238 TCP IP User s Manual http safe int http safe char to char from int tolen int fromlen DESCRIPTION Convert a http unsafe string in from length fromlen into a properly escaped string For example the string hello amp goodbye lt gt would be changed to hello amp amp goodbye amp lt amp gt Returns non zero if result could not fit in tolen 1 bytes A null is always added thus tolen should account for this Double quotes are escaped since the result may itself be quoted Newline characters are turned into HTML line break lt BR gt markup Control charac ters codes less than 32 are turned into amp xx where xx is the hexadecimal control char value The source string can contain null character s which is why its length is passed in the parameter fromlen PARAMETERS to Destination buffer for escaped string from Source buffer for string to convert tolen Length of destination buffer must be at least equal to fromlen since string is never smaller than source string fromlen Length of source buffer RETURN VALUE
139. d in buf is not automatically sent to the web client It is the caller s responsibility to send the header in buf along with any other HTTP headers to the client When a page is requested from the client and the cookie is already set the text of the cookie will be stored in state gt cookie This isa char and if no cookie was available state gt cookie 0 will equal 0 PARAMETERS buf Buffer to store cookie generation header that is the name of the cookie value Text to store in cookie generation header that is the value of the cookie LIBRARY HTTP LIB 244 TCP IP User s Manual http set path int http set path char rootdir char dfltname DESCRIPTION Set the default root directory and resource name for all HTTP server instances In gen eral this function should be called once only after http init but before http handler The root directory is the base directory and is used as a prefix for all resource requests from clients For example if the root directory is set to A then a client request for http lt hostname gt foo htm will look up the resource called A foo htm on this server The default resource name is used if the client s URL requests a directory For example if df ltname is set to index htm and rootdir is A then a client request for http lt hostname gt admin will look up the resource called A admin If that resource is actually a directory then it will look
140. d in the application program and named console io This structure holds handlers for common I O functions for the I O method typedef struct long param Baud for serial port for telnet etc int open void close int tick int puts int rdUsed int wrUsed int wrFree int read int write ConsoleIO 11 5 1 How to Include an I O Method Each supported I O method is determined at compile time i e each supported I O method must have an entry in console iof 11 5 2 Predefined I O Methods Several predefined I O methods are in Zconsole 1ib They will be included by entering their respective macros in console io const ConsoleIO console io CONSOLE IO SERA baud rate CONSOLE IO SERB baud rate CONSOLE IO SERC baud rate CONSOLE IO SERD baud rate CONSOLE IO SP channel number CONSOLE IO TELNET port number The macros expand to the appropriate set of pre defined handler functions e g define CONSOLE IO SERA param param serAopen serAclose NULL conio serAputs serArdUsed serAwrUsed serAwrFree serAread serAwrite 11 5 2 1 Serial Ports There are predefined I O methods for all four of the serial ports on a Rabbit board The baud rate is set by passing it to the macro See above 11 5 2 2 Telnet Zconsole runs a telnet server The port number is passed to the macro CONSOLE IO TELNET The user telnets to the controller that is running
141. d server DESCRIPTION Find the server spec entry for ilenum The entry must be of type SSPEC_FSFILE and be allowed with the specified server PARAMETERS filenum File to search for This value is the number passed in as the 2nd parm to fcreate or the return value from fcreate_ unused server The server making the request e g SERVER HTTP RETURN VALUE 1 Failure 20 Success index into resource list LIBRARY ZSERVER LIB SEE ALSO sspec_findname 86 TCP IP User s Manual sspec findnextfile int sspec findnextfile int start word servermask j DESCRIPTION Find the first spec file entry at or following the start spec that is accessible by the given server When the end of the RAM entries is reached the flash entries are searched Virtual filesystem entries are not considered Only entries for which sspec_gettype would return SSPEC_ FILE are considered If you are using this function to iterate through the available resources then the caller is responsible for incrementing the starting point To do this you can call the function sspec_nexthandle which will return the next valid handle after the given one or 1 if no more handles PARAMETERS start The array index at which to begin the search 1 starts searching the RAM entries servermask The server making the request e g SERVER HTTP RETURN VALUE 1 Failure 20 Success index of requested ServerSpec structure LIBRARY ZSERVE
142. dex of the form fptr Pointer to user function to be called just before form generation RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_getpreformfunction Chapter 3 Server Utility Library 145 sspec setrealm int sspec setrealm int sspec char realm DESCRIPTION Sets the realm field of a ServerSpec structure for HTTP authentication purposes Setting this field enables authentication for the given spec entry Authentication can be turned off again by passing as the realm parameter to this function Note realm must NOT point to an auto variable since only the pointer is stored The string is NOT copied PARAMETERS sspec spec index this must refer to the RAM resource table realm Name of the realm RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_getrealm 146 TCP IP User s Manual sspec setsavedata int sspec setsavedata char data unsigned long len void fptr DESCRIPTION Sets user supplied data that will be saved in addition to the spec and user authentication tables when sspec_ save is called PARAMETERS data Pointer to location of user supplied data len Length of the user supplied data in bytes fptr Pointer to a function that will be called when the user supplied data has been restored RETURN VALUE 0 Successfully set up the user supplied data 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspe
143. ds on the Dynamic C networking suite which is included in your program by writing use dertcp lib Setting up the network subsystem is a necessary pre requisite for use of HTTP This is described in volume 1 of the manual However it can be quite simple for test applications and samples to ini tialize the network subsystem In the file tcp_config lib are predefined configurations that may be accessed by a define of the macro TCPCONFIG For instructions on how to set up differ ent configurations please see volume 1 of the manual or look in the file LIB TCPIP TCP CONFIG LIB HTTP makes use of the Zserver library to manage resources and access control The previous chapter discusses Zserver When reading this chapter it will help if you are familiar with Zserver its interfaces and capabilities Much of this chapter contains material that could be considered advanced usage There is also some material of a historical nature with relevant sections marked as such Chapter 4 HTTP Server 153 4 1 HTTP Server Data Structures The single data structure in HTTP LIB of interest to developers of CGI functions is discussed in this section 4 1 1 HttpState Use of the Ht tpState structure is necessary for CGI functions whether or not they were writ ten prior to Dynamic C 8 50 Some of the fields are off limits to developers The field that are available for use are described in the next section Historical note prior to Dynamic C
144. ds to be performed Since the user ID table cannot be statically initialized i e at compile time this is a necessary step The rule table can be statically initialized but in this example we choose to do it at runtime First the rule table entry sspec addrule index html Pet admin_group monitor_group 0 SERVER_HTTP SERVER AUTH BASIC NULL The first parameter specifies the name of the resource to which this rule applies or rather the first characters in the resource name For clarity the sample shows the full name In practice since there is only one resource it would be acceptable to use just instead of index html The second parameter Pet is an arbitrary string called the realm This is presented to the browser s user when prompted for the password as shown here Enter Network Password 21x gt Please type your user name and password Site 10 10 4 22 Realm Pet User Name Password I Save this password in your password list Cancel The third and fourth parameters indicate the group s that have read and write access to the resource Both groups are allowed read access and none write 0 Note that the resource in this case is the index html page not the variables which may or may not be displayed on it Since this web page actually a ZHTML script is in program flash it is obviously not modifiable The SERVER_HTTP parameter indicates that this resource is only v
145. e located in Samples Tcpip Http Pages gives an example of dynamically changing a variable on a web page using echo var img SRCS 2el Hacho wee leci s sls In an shtml file the lt echo var led1 gt is replaced by the value of the variable led1 from the static resource table SSPEC RESOURCETABLE START o SSPEC RESOURCE ROOTVAR SSPEC RESOURCE ROOTVAR SSPEC RESOURCE ROOTVAR SSPEC RESOURCE ROOTVAR vledi i redi PERLE 1 WALA Aleyol PIRES T vedot Lees PIRIC led4 led4 PTR16 E EN oA o o SSPEC RESOURCETABLE END shtml_handler which is the built in script processor for SSI looks up 1ed1 and replaces it with the text output from primet We laeite edine The led1 variable is either ledon gif or ledoff gif When the browser loads the page it replaces kale SRCS lt 2l Haclo wee leci s sls with lt img SRC ledon gif gt 1 This is just a convention If you add a MIMETypeMap entry SSPEC_MIME_FUNC shtml text html shtml_handler then you are following this convention 168 TCP IP User s Manual or lt img SRC ledoff gif gt This causes the browser to load the appropriate image file SSI string variables are only appropriate for relatively short strings In the above example the SSI string variables are ledon gif and ledoff gif The size that can be output is li
146. e VSERIAL LIB implement application layer protocols Except for BOOTP which is described in volume 1 of the manual these protocols are described in volume 2 All user callable functions are listed and described in their appropriate chapter Example programs throughout both volumes of the manual illustrate the use of all the different protocols The sample code also provides templates for creating servers and clients of various types To address embedded system design needs additional functionality has been included in Dynamic C s implementation of TCP IP There are step by step instructions on how to create HTML forms allowing remote access and manipulation of information There is also a serial based console that can be used with TCP IP to open up legacy systems for additional control and monitoring The console may also be used for configuration when a serial port is available The console and HTML forms are discussed in volume 2 Multiple interfaces are supported starting with Dynamic C version 7 30 Introduction 1 TCP IP User s Manual 2 Web Enabling Your Application This chapter and the next two describe how to add web browser control to your application Web enabling is a logical and appealing choice for adding a user interface to your application since the necessary hardware an Ethernet or serial port is available on all Z World core modules and SBCs Most users of your application will be familiar with at least
147. e application code SSPEC MIMETABLE START SSPEC MIME html text html SSPEC MIME gif image gif SSPEC MIMETABLE END Use of the above macros is the recommended method for maintaining forward compatibility For more information see Section 3 2 5 2 Static MIME Type Table All these macros are doing is generating the correct C syntax for a static constant initializer Note that servers that do not implement MIME such as FTP do not require a MIME table to be defined Currently this table is required only for HTTP 32 TCP IP User s Manual 3 1 2 ServerSpec Structure This structure is used for both the static and dynamic resource tables The only difference between these two tables is that one is a constant initialized at compile time and the other is created at runtime in RAM and thus modifiable Historical note The HttpSpec data structure in HTTP 1ib used prior to Dynamic C 8 50 is now synonymous with this structure ServerSpec typedef struct word type char name SSPEC MAXNAME long data void addr word vartype char format ServerPermissions perm ifdef FORM ERROR BUF endif ServerSpec The structure fields are described below The ifdef expression adds some fields to the ServerSpec structure if the HTML form functionality provided by Zserver is included by the web server application These fields are not described below For more details Section 4 5 4 HTML Forms Using
148. e connection gt lt wait for next connection gt For debugging purposes you can observe this conversation by defining POP_ DEBUG at the top of your program Chapter 9 POP3 Client 331 332 TCP IP User s Manual 10 Telnet The library Vserial 1ib implements the telecommunications network interface known as tel net The implementation is a telnet to serial and serial to telnet gateway This chapter is divided into two parts The first part describes the library from Dynamic C version 7 05 and later The sec ond part describes the library prior to 7 05 10 1 Telnet Dynamic C 7 05 and later This implementation is more general than the previous one Any of the four serial ports can be used and other I O streams can be added Multiple connections are supported by the use of unique gateway identifiers 10 1 1 Setup To use a serial port the circular buffers must be initialized For instance if serial port A is used by an application then the following macros must be defined in the program define AINBUFSIZE 31 define AOUTBUFSIZE 31 It might be necessary to have bigger buffers for some applications 10 1 1 1 Low Level Serial Routines A table to hold the low level I O routines must be defined as type VSerialSpec typedef struct int id unique ID to match with calls to listen open int open serial port routines or int close serial port compatible routines int tick int rdUsed
149. e following lt HTML gt lt HEAD gt lt TITLE gt ACME Thermostat Settings lt TITLE gt lt HEAD gt lt BODY gt lt H1 gt ACME Thermostat Settings lt H1 gt lt FORM ACTION myform html METHOD POST gt lt TABLE BORDER gt lt TR gt lt TD gt Name lt TD gt lt TD gt Value lt TD gt lt TD gt Description lt TD gt lt TR gt lt TR gt lt TD gt High Temp lt TD gt lt TD gt lt INPUT TYPE text NAME temphi VALUE 80 SIZE 5 gt lt TD gt lt TD gt Maximum in temperature range amp deg F lt TD gt lt TR gt lt TR gt lt TD gt Low Temp lt TD gt lt TD gt lt INPUT TYPE text NAME templo VALUE 65 SIZE 5 gt lt TD gt lt TD gt Minimum in temperature range amp deg F lt TD gt lt TR gt lt TABLE gt lt P gt lt INPUT TYPE Submit VALUE Submit gt lt INPUT TYPE reset Value Reset gt s lt FORM gt lt BODY gt lt HTML gt The form might display as fol ACME Thermostat Settings Netscape Of x lows File Edit View Go Communicator Help 7 Back Forwerd Reload Home Search Netscape Print sy cE Bookmarks Location file CI myform html a What s Related ACME Thermostat Settings Name Value Description High Temp ao Maximum in temperature range F Low Temp es Minimum in temperature range F Submit Reset BEE Domen Done zg w3 AD A ve 7 Chapter 4 HTTP Server 171 When the form is displayed by a browser the u
150. e g when writing to an underlying filesystem that streams data to a peer 1 1en The specified number of characters has been copied from the supplied buffer and the current file position has been advanced by that many bytes Possibly less than len bytes may be written in which case the server should attempt to write the remain ing data later The following return values are negatives of the values defined in errno lib EINVAL len parameter was lt 0 EBADF The specified handle was not open or invalid ENOSPC There is insufficient space in the underlying filesystem or the file cannot be extended EPERM The file resource does not support writing e g xmem files or a read only filesystem Any other negative values indicate an error SEE ALSO sspec_close sspec_read sspec_seek sspec_tell sspec_open 152 TCP IP User s Manual 4 HTTP Server This chapter is intended to be a detailed description of the HTTP server and how it interfaces to other libraries such as Zserver and TCP IP For an overview of how these libraries interface with one another and with your application please see Chapter 2 Web Enabling Your Application An HTTP Hypertext Transfer Protocol server makes HTML Hypertext Markup Language pages and other resources available to clients that is web browsers HTTP is implemented by HTTP LIB thus you need to write use http 1lib near the top of your program HTTP depen
151. e my_io polling function is shown updating the web variable but we don t specify the actual I O reading function since that is too well applica tion specific Now you may be wondering what this scripting language ZHTML looks like The following code shows the contents of the my _app zhtml file lt HTML gt lt HEAD gt lt TITLE gt Web Variables lt TITLE gt lt HEAD gt lt BODY gt lt H1 gt Web Variables lt H1 gt lt P gt The current value of io state is lt z echo S io state gt lt P gt lt BODY gt lt HTML gt This looks like plain HTML and it is The only difference is the existence of special commands flanked by lt z and gt In this case the command simply echos the current value of the web variable that was registered The value binary in the global variable is converted to ASCII text by a default printf conversion in this case d because the variable is an integer When the browser gets the results returned by the HTTP server it will see lt HTML gt lt HEAD gt lt TITLE gt Web Variables lt TITLE gt lt HEAD gt lt BODY gt lt H1 gt Web Variables lt H1 gt lt P gt The current value of io state is 50 lt P gt lt BODY gt lt HTML gt Where the 50 represents the current variable value of course it may be any decimal value that an integer variable could take 32768 through 32767 This is still a trivial example but it is infinitely more real world than the toy
152. e next call when the CGI returns CGI_ MORE Writing Responses to the Client from a CGI Function A CGI function is able to generate all or part of the response to the client To do this it has to fol low the HTTP specification That is it must write the response headers plus the HTML content The HTTP headers must be the first thing written At a minimum the header lines look like the following HTTP 1 0 200 OK Date Sun 20 Jan 1980 23 27 10 GMT Content Type text html NOTE Each line must be terminated with a CRLF that is r n and there must be a blank line after the last header The date string can be constructed using the http _date_str function You can create the headers in one hit using the following code char date 30 sprintf http getData s HTTP 1 0 200 OK r nDate s r nContent Type text html r n r n http date _str date Then send it to the client by returning CGI_SEND straight away CGI_ SEND tells the HTTP server that the CGI function has put a null terminated string inthe http _getData buffer and that the server should not call the CGI again until the string has been sent This is the most convenient way of sending relatively small amounts of data at a time It relies on the fact that the CGI is allowed to write to the buffer returned by http_getData Since http _getData is used to pass incoming data to the CGI it is important to ensure that the incoming data has been fully processed be
153. e return value is the minimum sized buffer that should be passed on the next call Note this sort of return is not currently implemented by any of the file systems however servers should be coded to handle this case for future anticipated systems which have record level access rather than byte lev el The following return values are negatives of the values defined in errno 1lib e EINVA len parameter was lt 0 e EBADF The specified handle was not open or invalid e Any other negative values indicate an error SEE ALSO sspec_close sspec_write sspec_seek sspec_tell sspec_open 120 TCP IP User s Manual sspec readfile int sspec readfile int sspec char buffer long offset int len DESCRIPTION Read a file represented by the sspec index into buffer starting at offset and only copying len bytes For xmem files this function automatically skips the first 4 bytes Hence an offset of 0 marks the beginning of the file contents not the file length This function is intended for file types that do not require explicit open or close calls that is root or xmem files It can also be called for FS2 files but this is not recommend ed since each call requires the file to be opened seeked read then closed Instead use sspec_open sspec_read and sspec_close calls which are the most efficient sspec_ readfile has the advantage of being stateless but the price to pay is great loss of efficiency especi
154. e structure is 200 504 supported a continuous stream of data bytes SYST Sends the string RABBIT2000 215 TYPE Confirms the transfer type The types IMAGE binary ASCII and 200 504 Local with 8 bit bytes are all supported and are treated the same i USER User name to use for authentication 331 530 300 TCP IP User s Manual 6 7 Reply Codes to FTP Commands The FTP server replies to all of the commands that it receives The reply consists of a 3 digit num ber followed by a space and then a text string explaining the reply All reply codes sent from the FTP server are listed here Table 6 3 Reply Code Reply Text 150 File status okay about to open data connection 200 Command okay 202 Command not implemented superfluous at this site 211 System status or system help reply 213 File status 214 Help message On how to use the server or the meaning of a particular non standard command This reply is useful only to the human user 215 System type 220 Service ready for new user 221 Service closing connection 226 Closing data connection Requested file action successful for example file transfer or file abort 227 Entering Passive Mode h1 h2 h3 h4 p1 p2 230 User logged in proceed 250 Requested file action okay completed 257 PATHNAME created 331 User name okay need password 425 Can t open data connection 450 R
155. e to upload The order is important Browsers will send back the form fields in the same order that they are defined in the HTML however it is probably best not to rely on this if you can help it lt TR gt lt TR gt lt TD ALIGN RIGHT gt lt B gt File to upload lt BR gt to A new htm lt B gt lt TD gt lt TD gt lt INPUT TYPE FILE NAME A new htm SIZE 50 gt lt TD gt This is the file to upload input field The browser displays this as a text input field with an addi tional browse button so that the user can easily navigate his local filesystem to find the appropri ate file The critical distinction is that it contains a type file parameter as opposed to for example type text in the previous field The name A new htm parameter specifies the name of the input field not the name of the file on the user s system As it happens this looks like a file name and indeed the server may use it as the name of a local file but this is a convention only The size 50 parameter specifies the number of characters that the browser will display for file name selection lt TR gt lt TABLE gt lt INPUT TYPE SUBMIT VALUE Upload gt It is necessary to supply a type submit form element The user presses this button to start to post upload process Note that this is another input field however if you leave out the name parameter as in this example then the browser will not send the value of this button back with the
156. e zimport 1lib comes before the statement use http 1ib in the code This is required to have file compression support in Zserver and the web server The next thing to notice is the use of the compiler directive Zimport instead of ximport zimport performs a standard ximport but com presses the file by invoking a compression utility before emitting the file to the target When adding a compressed file to the static resource table use the macro SSPEC RESOURCE ZMEMFILE instead of SSPEC_ RESOURCE XMEMFILE When you add a compressed file to the dynamic resource table using the sspec_addxmemfile function it will be recognized as a compressed file automatically sspec_addxmemfile is thus used for both compressed and uncompressed imported files Each instance of a server will use a buffer for decompression this is necessary since multiple server instances can be decompressing files at the same time Make sure that the buffer macro INPUT _COMPRESSION_ BUFFERS is at least as large as the number of servers which may need concurrently to decompress a compressed resource The buffer macro describes the number of 4KB xmem RAM buffers used for decompression This definition is used by the zimport 1lib library For details on compression ratios memory usage and performance please see Technical Note 234 File Compression For more information on using zimport and the support libraries please see the Dynamic C User s Manual and the
157. eams 357 8 5 API Functions 0 cece cccccesseesseeeeeeees 316 11 6 Zconsole Execution cccccccccccseccescceee 358 smtp_data_handler ETT 316 File System Initialization 358 ance dal sie sheen ETETE ETE E avons 3 Serial Buffers 358 smtp_sendmailxmem R EA 320 Using TCP IP 358 smtp_setauth soctislscorcacscoaccedotenaes 321 Required Zconsole Functions 359 SMUP_SCtSCTVET eeeeeeeeeeeeceneeeeeeees 322 CONSOLE _INt eee eeeeeeeeeeeeeee eee 359 SMtp_SEtserver_ip eeeeeeeeeseeeeeeees 322 CONSOLE HCR niokeen 359 SMUP_StatUs 0 eeeeeseeeeeseeeeseeeeeees 323 Useful Zconsole Function 360 Conzbackup wiisoowted ccmoeieentatls 360 9 POP Client wssnsnssennnnnnee 325 a a 9 1 Configuration E E E T A 325 con_backup_reserve iia Hele ae oe ee Bes aes 361 9 2 Steps to Receive E mail ccee 326 es Settee eeeeeeeteeeteeeeneees oe con_load_backup eeeeeeeeeseeeeeee 9 3 Call Back Function ccccceeeeeseeeeeeees 326 GOH TESE EIO o a n eai 362 Normal call back 326 con_set_backup_1x eesse 363 POP_PARSE_EXTRA call back 326 con_set_files_1x ecese 363 9 4 API Functions 327 con_set_user_idle eee eee 364 i A gi nee ee 27 CON_S t_tiMEOUL cece eeeeeeees 364 POPS itsenne a a 3 con set user timeout 365 TCP IP User s Manual v console_disable cccceeeeeeeeeeeee 365 console_enable cceceeeeeeeeeeeee 366 Zconsole Execution Choices 367 11 7 Backup System eee eee 368 Data Structure for
158. ecessary for SSI and RabbitWeb scripts described later 4 5 2 Dynamic Web Pages Without HTML Forms Serving a dynamic web page without the use of HTML forms is done by sample program ssi c This program displays four lights and four buttons to toggle them Users can browse to the device and change the status of the lights The sample code follows but it has been edited for brevity Open ssi c in Dynamic C to see the fully commented source define TCPCONFIG 1 define HTTP MAXSERVERS 1 define MAX TCP SOCKET BUFFERS 1 define REDIRECTHOST _PRIMARY STATIC IP define REDIRECTTO http REDIRECTHOST index shtml1 memmap xmem muse d rtop Lib use http lib ximport samples tcpip http pages ssi shtml index html ximport samples tcpip http pages rabbitl gif rabbitl gif ximport samples tcpip http pages ledon gif ledon gif ximport samples tcpip http pages ledoff gif ledoff gif ximport samples tcpip http pages button gif button gif ximport samples tcpip http pages showsre shtml showsre shtml ximport samples tcpip http ssi c ssi_c SSPEC MIMETABLE START SSPEC MIME FUNC shtml text html shtml handler SSPEC MIME html text html SSPEC MIME gif image gif SSPEC MIME Gus cgi nN SSPEC MIMETABLE END Chapter 4 HTTP Server 165 E char led1 15 char led2 15 char led3 15 char led4 15 int ledltoggle HttpState state if strcmp led1 ledon g
159. ed LIBRARY ZSERVER LIB Chapter 3 Server Utility Library 123 sspec removerule int sspec removerule char pfx DESCRIPTION Remove a rule from the dynamic resource rule table PARAMETER pix Prefix of resource name This must be an exact match to one of the rules previously added using sspec_addrule RETURN VALUE 20 OK 1 Error For example the rule was not found or maybe the rule was in the flash table f rule table SEE ALSO sspec_addrule 124 TCP IP User s Manual sspec removeuser int sspec removeuser int sspec int userid DESCRIPTION Removes the user group s that userid belongs to from the read and write access masks for the specified resource This will deny access to other users who have the same group s as the current user This function is deprecated as of Dynamic C 8 50 Use the more general sspec_setpermissions function instead PARAMETERS sspec spec index userid user index RETURN VALUE 0 Success user was removed 1 Failure no such userid found LIBRARY ZSERVER LIB SEE ALSO sspec_setuser sspec_adduser sspec_getusername sspec_getuserid sspec_setpermissions Chapter 3 Server Utility Library 125 sspec resizerootfile int sspec resizerootfile int spec index int new size DESCRIPTION Change the byte size of a SSPEC item stored in root memory Item must be a ROOTFILE thus the item must have been created with sspec_addrootfile
160. ed as a function with the following prototype void my_headers HttpState state char buffer int bytes state Pointer to the state structure for the calling web server buffer The buffer in which the header s can be written bytes The number of bytes available in the buffer Typically the macro would be defined by the user before the use http 1lib statement like in the following define HTTP CUSTOM HEADERS state buffer bytes my headers state buffer bytes Chapter 4 HTTP Server 159 Then for the above to work my headers must be defined by the user like so void my_ headers HttpState state char buffer int bytes strcpy buffer Fake Header Hello Z World r n printf bytes d n bytes In the real world the user may need to check the number of bytes available to be sure they don t overwrite the buffer The buffer must end with r n and be NULL terminated 4 2 2 Saving Custom Headers from the Client Customers may want to save some specific headers that a web client sends to the server as part of a request One possibility for this is to check the browser version of the client and display a differ ent page depending on that value This is mostly useful for CGI functions The user can create a structure like the following to indicate to the web server that it should save the specified tags const HttpHeader http headers Host e Content Length User Agent END _
161. ed to the browser Unless the application only returns information and does not allow any updates such as a data logger you will probably need to lay out some forms Forms in web parlance allow the browser s user to fill in some infor mation then submit it to the server The server your application then performs the requested actions and sends a confirmation back to the browser This is the most common means for imple menting control of the server as opposed to merely querying it There are several other things to consider Answers to the following list of questions will deter mine the pieces of software that need to be gathered into your application and how they link together e Does access to some or all resources need to be limited to a select set of users e Ifso how confident does your application need to be that the user s credentials are valid e Do you need to be able to upload large amounts of data over say 250 bytes e Do you want to be able to update the web pages themselves or maybe even the entire appli cation firmware e Is the application small medium or large e Do you want to use this same web interface to configure all aspects of the application including for example the network settings In other words is the web interface going to be the only interface once the unit leaves the factory Chapter 2 Web Enabling Your Application 3 The first and second questions relate to user authentication and a
162. edoff gif strcpy led4 ledon gif Pe ee SoCs aae 7 Heep init CepEresSorvepontiNoONE while 1 http handler When you compile and run ssi c you see the LNK light on the board come on Point your browser at the controller e g http 10 10 6 100 The ACT light will flash a couple of times and your browser will display the page This program displays pictures of LEDs Their state is toggled by pressing the image of a button This program uses Server Side Includes SSI and the old style of CGI SSPEC_ RESOURCE FUNCTION Use of SSI is explained in greater detail below Chapter 4 HTTP Server 167 4 5 2 1 SSI Feature SSI commands are an extension of the HTML comment command lt This is a comment gt They allow dynamic changes to HTML files and are resolved at the server side so the client never sees them HTML files that need to be parsed because they contain SSI commands are conven tionally recognized by the HTTP server by the resource name extension shtml The supported SSI commands are e echo var e exec cmd e include file They are used by inserting the command into an HTML file lt include file anyfile gt The server replaces the command include file with the contents of anyfile exec cmd executes a command i e and old style CGI and replaces the SSI command with the output Dynamically Changing the Display of a Variable on a Web Page The Ssi shtml fil
163. ee 101 ServerPermissions Servermask Field 39 sspec_getMIMEtype eM OSG esse ood NIECE 102 Configuration Macros 39 ne A EEEE a Miser Coen Data alist sspec_getpreformfunction u 105 sspec_getrealM ee eeeeeeeee 106 3 3 File Compression Support 44 poet ered ees seeteeeeeeseseeeeeees T SSpeEC_geEttype ssesesseseeeeeereesreeeersesees 3 4 HTML ForS an iensisenstnsonneisen 45 sspec_getuserid E AE he ET Pie if 109 3 5 API Functions s eseseeeeeeeeeeeeresessrrrrereees 45 sspec_getusermaMe eee 110 sauth_adduset ccccecceseseeseeeeereeeeees 46 sspec_getvaraddr seseeeeeeeeees 111 sauth_authenticate ccccceeeeeeee 47 sspec_getvarkind seeeeees 112 sauth_getpassword cseeseeseeeeees 48 SSPEC_QETVALLYPC seereeereeeeeereeeeees 113 Sauth_getserver cee eeteeeeeeeeees 48 sspec_getxvaraddr u 113 sauth_getuserid 00 eeeeeeeees 49 sspec_mkdir peepeeeeereereeereere 114 sauth_getusermask ecsecseeeees 50 sspec_needsauthentication 115 sauth_getusername TEAPA EEE IEE 51 SSpeEecC_Open sesseseresesreerereeseereereseeeee 116 sauth_getwriteaccess 0 00 52 e brtererereereereeereereeereersereeeneene oe SaUth_LEMOVEUSET cceceeeeeseseeeseeees 53 SSPEC_TCA sssceseeseeseeseseeeseeseeeeeees sauth_setpasswot eseceeseeeeeeeee 54 pete at oe Steen eeeeeee eee eeeteeseneeees is SAUth_SetSCrveL cccccecssccscscecesseeees 55 SSPEC_TCAAVALIADIC
164. ee ceeeeseeeeeees 242 SSPC SAVE eiieeii iaer eis ees 129 http_shutdown ssssesseeeeesesreersessesrsersesseee 247 sspec_setsavedata eeceeeceeecereeesceeneees 147 httpestatUS oiin epei ariari 258 SSpec SetUSEL rrisin inesspses ressats ivers 148 MIME Types Telnet sspec_getMIMEtype 00 eee 102 telnet cl set 340 Resource Access Control telet Init BAA Ah eA 339 SSPEC ACCESS sn sicescsscsistesoscnscesnsscvnsensesssedavens 58 telnet_tick oo ececececeessssssssssssscseseseseeees 340 sspec_checkpermissiONs ceeeceeeseeeeees 76 VSettal CLOSE snc ccc ce pep eas 334 SSPEC_QEtPETMISSIONS ceeeeeeeeseeeeeeee 104 Vserial It wcscsee esceass essieesebbessedesstseveness 334 sspec_getrealm oo eects cseeeeteeee 106 vserial_keepalive n se 335 SSpecC_setpermissions eeeeeeeeeeseceeeeees 144 yserial JSteN sssini iiis nesies 336 SSPec_SetrealM inasre eenei enei 146 yserial open ririmerii 337 Resource Location and Information yserial_tick eeeeseseeeeeeeeerereessseresererererere 338 sspec_findfsname cceesceeeceeeeeneeeeees 86 TFTP Client sspec_findname sssirissisisicteeosesisriesiissrses 85 Aa EEFE hesteneti ees 309 sspec_findnextfile sseeseeeeeeeeeereereeeeeeeee 87 AAA on E o AAEE ET 305 sspec ge tfileloC snit 88 HEtP INIX ascsvesseiscesssschisnenesiabiany eers 306 sspec_getfiletype sseeeeseeeeereeerrererrereeesee 89 CHOP MICK sees Sa its aes Ba eat eeh betes 307 Sspec_getfUNCtiON ee eee eeee
165. eeee tees 91 CEE TICK Sibson cases sedstess subs sideedasguasbionseted 308 sspec_getlength oo eee eseeeeceeeee 101 SSPCC_QEtNAME Tenir uiris 103 H sspec_getservermask ssssssssrertrersererserer 107 FUT ML forms ooon 45 170 181 SSPECUBEUY PO a hee ie ai 108 HTTP configuration Macros scssssceseseesseeee 157 sspec_getvaraddr sesee reese l1 HTTP server snene 153 266 sspec_getvarkind s sssssssesstsrtseesersrserstsrers US HapState nassir 154 sspec_getvartype oo ee eee cee estate eens 113 sspec_getxvaraddr seese 113 L Resource Retrieval and Update BSCE S estates Uieita Site tetea attache ata 77 listing directory entries s seseeseseeesesseeseesseeere 79 SSpec delete soinnin a e S ai a 78 M SSPOC MAKI mres ihe aeaii 114 oloo D11 a SE 116 macros sspec_readvariable cceeeeeeteeeeeees 122 FIP SOR VOR enne a eaaa HAR 278 SSpeC IMAI o ooe een N 128 HTTP servete aaa ee 157 S TE svnicenceesbta seas eeeeeaets 130 serial ports for telnet ccceceeeseeseeeeeteeees 333 SSPEC STALE co cc ee eres edd oes A is 149 SMTP client sneep 314 SSPCC telleren anaa 151 telnet 7 05 and later wo cece ceeeeeeeeeeees 334 SSPECX E E E Sein eae 152 telnet pre 7 05 ccccccssssesssessscccssessscesseeesees 339 Server Resource Management ZGONS OLE Gk weds as feessevoes e ines geese ste 370 Nt add Giles scsnwiensanianapeapaeaes 206 MIME ty pes s cc cutis nates 32 164 http 2delfile nrnna 211 shtml_addfunction cccsssssssssse
166. enge gt where lt challenge gt is a unique Base64 encoded challenge string for example lt 4994 1088035610 zworld com gt The client generates a digest using the following MD5 hashing algorithm where pass word is null padded to a length of 64 bytes ipad is 0x36 repeated 64 times and opad is Ox5C repeated 64 times digest MD5 password XOR opad MD5 password XOR ipad challenge The client responds with the string lt username gt lt response gt Base64 encoded lt user name gt is in plaintext and lt response gt is the 16 byte digest in hex form This method is the most secure since someone sniffing the connection would be unable to determine the cleartext password used to authenticate 312 TCP IP User s Manual 8 3 Sample Sending of an E mail This program smtp c sends an e mail To have the client query the server for authentication define the macro USE_SMTP_AUTH and call smtp_setauth before calling smtp sendmail orsmtp sendmailxmem If the mail server does not support authentication either do not define USE SMTP AUTH or pass empty strings as the parameters tosmtp_setauth Program Name Samples tcpip smtp smtp c define TCPCONFIG 1 pick network configuration define FROM myaddress mydomain com define TO myaddress mydomain com define SUBJECT You ve got mail define BODY Visit the Rabbit Semiconductor web site r n SMTP_SERVER identifies the ma
167. ength http_getContentType http_getContentDisposition http_getTransferEncoding http_getData http_getDataLength CGI_END http_getField http_getContentLength http_getContentType http_getContentDisposition http_getTransferEncoding CGI_HEADER CGI_ PROLOG CGI_EPILOG CGI_EOF http_getData http_getDataLength CGI_CONTINUE Depends on previous action code at time of returning CGI_MORE however http _getData will NOT be valid Chapter 4 HTTP Server 215 Table 4 1 Valid Functions per Action Code CGI Action Code Valid Functions Macros Should only do resource cleanup http_getContext http_getURL http_getState CGI ABORT http_getCond http_getUserState http_getHTTPVersion http_getHTTPMethod PARAMETER state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE Action code One of the following values e CGI START start of a part in a multi part transfer e CGI DATA binary data for this part e CGI_END end ofa part CGI_HEADER header line of a part CGI PROLOG binary data before the first part CGI EPILOG line of data after the last part e CGI EOF normal end of all parts and epilog e CGI ABORT abnormal termination CGI should recover and or close any open resources CGI CONTINUE being called from the HTTP server after the CGI previously returned CGI_ MORE LIBRARY HTTP LIB SEE ALSO functions me
168. ent the http _switchCGI function takes care of most needs If this function is used then the CGI is responsible for generating the correct HTTP response including head ers and http_switchCGI and similar functions should NOT be called Use of this function can often be avoided Instead the CGI can copy a string to the pointer provided by http _getData thenreturn CGI_ SEND This will cause the server to send out the null terminated string in the buffer and not call the CGI until the string is sent to the client See the source to http_defaultCGI for an exam ple of this method PARAMETERS state HTTP state pointer as provided to the CGI function data Pointer to first char to transmit It is OK to make this the same pointer that was returned by http _getData since that buff er can be used for output as well as input In any case the CGI must ensure that it has processed any incoming data before writing new data to that buffer length Length of data to transmit There is a limit to the amount of data thathttp write can write on any given call This limit is set by the HTTP server socket transmit buffer size This buffer size is given by TCP_BUF_SIZE 2 The transmit buffer is usually at least 1024 bytes If you try exceeding that limit http write will never succeed Chapter 4 HTTP Server 261 RETURN VALUE 0 data written or buffered successfully CGI_MORE data not written try again on next call to the
169. ent HTTP server context The context pointer is required by many zserv er resource handler functions NOTE This is implemented as a macro PARAMETER state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE Pointer to the HTTP server s context structure See zserver documentation LIBRARY HTTP LIB SEE ALSO http getAction 222 TCP IP User s Manual http getData char http getData HttpState state DESCRIPTION Return a pointer to the data that is available It is only valid to call this if the action code is one of CGI_ DATA CGI_ PROLOG CGI_EPILOG CGI HEADER or CGI_ EOF When CGI_ DATA this is the next chunk of data received as the content of the current part of a multi part transfer The data arrives in arbitrary amounts CRLF boundaries if any are not respected and the data may contain NULLs and other binary values THE CGI MUST CONSUME ALL DATA PROVIDED since the data will not be presented again on the next call When CGI_ PROLOG this is data that occurs before the first boundary part but after the main HTTP headers This data like that for CGI DATA is not line oriented When CGI_EPILOG CGI_HEADER or CGI_ EOF the data will be a complete line of input with the terminating CRLF stripped off The returned string will also be null terminated When CGI_EOF the data if any is technically part of the epilog Prolog data is lines of input that were provided before t
170. enting the current directory dir String that indicates the new directory that will become the current directory The interpretation of this string is entirely up to the han dler The dir string will be passed as to move up one level uid The currently logged in user RETURN VALUE 0 No such directory exists 1 Root directory gt 0 Anything that is meaningful to the handler Chapter 6 FTP Server 287 ftp dflt pwd int ftp dflt pwd int cwd char buf DESCRIPTION Print the current directory passed as cwad as a string The result is placed in buf whose length may be assumed to be at least FTP_MAXLINE 6 The return value is ignored PARAMETERS cwd The current directory buf Pointer to buffer to put the string RETURN VALUE The return value is ignored 288 TCP IP User s Manual ftp dflt mdtm unsigned long ftp dflt mdtm int fd DESCRIPTION This handler function is called when the server receives the FTP command MDTM The return value of this handler function is the number of seconds that have passed since January 1 1980 A return value of zero will cause the reply code 213 followed by a space and then the value 19800101000000 yyyymmddhhmmss to be sent by the serv er The FTP server assumes that this return value is in UTC Coordinated Universal Time If SEC_ TIMER is running in local time the handler should make the necessary time zone adjustment so that the return value is expressed
171. equested file action not taken File unavailable e g file busy 452 Requested action not taken Insufficient storage space in system 502 Command not implemented 504 Command not implemented for that parameter 530 Not logged in 550 Requested action not taken File unavailable e g file not found no access The text used for the reply codes may be slightly different than what is shown here It will be con text specific Chapter 6 FTP Server 301 302 TCP IP User s Manual 7 TFTP Client TFTP LIB implements the Trivial File Transfer Protocol TFTP This standard protocol inter net RFC783 is a lightweight protocol typically used to transfer bootstrap or configuration files from a server to a client host such as a diskless workstation TFTP allows data to be sent in either direction between client and server using UDP as the underlying transport This library fully implements TFTP but as a client only Compared with more capable protocols such as FTP TFTP e has no security or authentication is not as fast because of the step by step protocol e uses fewer machine resources Because of the lack of authentication most TFTP servers restrict the set of accessible files to a small number of configuration files in a single directory For uploading files servers are usually configured to accept only certain file names that are writable by any user If these restrictions are acceptable TFTP has
172. er of seconds that pass before a time out occurs Chapter 5 FTP Client 267 5 2 API Functions ftp client setup int ftp client setup long host int port char username char password int mode char filename char dir char buffer int length DESCRIPTION Sets up a FTP transfer It is called first then ftp client _tick is called until it returns non zero Failure can occur if the host address is zero if length is negative or if the internal control socket to the FTP server cannot be opened e g because of lack of socket buffers PARAMETERS host Host IP address of FTP server port Port of FTP server 0 for default username Username of account on FTP server password Password of account on FTP server mode Mode of transfer FTP_MODE UPLOAD or FTP MODE DOWNLOAD You may also OR in the value FTP _MODE_ PASSIVE to use passive mode transfer important if you are behind a firewall filename Filename to get put dir Directory file is in NULL for default directory buffer Buffer to get put the file from to Must be NULL if a data handler function will be used See ftp_data_handler for more details length On upload length of file on download size of buffer This pa rameter limits the transfer size to a maximum of 32767 bytes For larger transfers it will be necessary to use a data handler func tion RETURN VALUE 0 Success 1 Failure LIBRARY FTP CLIENT LIB SEE ALSO ftp _client_tick ftp _data_h
173. erver Utility Library 115 int sspec open char name ServerContext context word mode sspec open DESCRIPTION Open a file resource by name The name may refer to a flash or RAM spec entry or may be the name of a file in a filesystem The resource namespace is specified as a directory hierarchy similar to a Unix like file system The root directory is the base for all named resources If s2 1ib is included then files stored in the FS2 filesystem are accessible under a mount point called s2 FS2 files do not have native names Instead each file is numbered from 1 to 255 Zserver assigns names to FS2 files by appending the file num ber in decimal to the string file For example FS2 file number 99 has a complete resource name of fs2 file99 If fat 1ib is included then all DOS FAT files are mounted under a drive letter The first partition of the first DOS FAT filesystem is called A and the second partition if any is called B etc For example if the FAT filesystem has a file called system ad min htm then the complete resource name will be A system admin htm NOTE Forward slashes are required Do not use backslashes as is customary with DOS filesystems If the resource name does not begin with fs2 or A etc then the resource is located in the static resource table flashspec that is the http _flashspec global table or in the dyna
174. es one parameter the IP address of the SMTP server con_set_nameserver This function changes the name server for the board A command that uses this function takes one parameter the IP address of the new name server in dotted quad notation e g 192 168 1 1 con_set_netmask This function changes the netmask of the board A command that uses this function takes one parameter the new netmask in dotted quad notation e g 255 255 255 0 con_set_tcpip_debug This function is intended to aid in development and debugging A command that uses this function takes one parameter the numerical level of debugging messages The higher the number the more verbose the TCP IP debugging messages will be con_show This function displays the current configuration of the board IP address netmask and gateway If the developer s application has configuration options she would like to show other than the IP address netmask and gateway she will probably want to implement her own version of the show command The new show command can be modelled after con_show inZConsole lib A command that uses this function takes no parameters con_show_multi Like the con_show function this function shows the current console configuration This com mand will however show more network configuration than is available via con_show Interface specific configuration information is separated out A command that uses this function takes an optional par
175. esize returns transfer size since we asked for download buf ftp_client_filesize 0 permer Uara gt Se N a oE i else pemer Vise ieeiilecls Sireicus Scl m ete 5 Chapter 5 FTP Client 275 276 TCP IP User s Manual 6 FTP Server This chapter documents the FTP server The following information is included e configuration macros the default file handlers e how to assign replacement file handlers e what to do when there is a firewall e API functions e commands accepted by the server e reply codes generated by the server e sample code demonstrating a working FTP server The library FTP _SERVER LIB implements the File Transfer Protocol for the server side of a connection FTP uses two TCP connections to transfer a file The FTP server does a passive open on well known port 21 and then listens for a client This is the command connection The server receives commands through this port and sends reply codes The second TCP connection is for the actual data transfer Anonymous FTP is supported Most FTP servers on the Internet use the identifier anonymous So since FTP clients expect it this is the identifier that is recommended But any string with a maximum length of HTTP_NO_FLASHSPEC SSPEC_NO_ STATIC may be used Dynamic C 8 includes some enhancements that basically let the FTP server act as a full FTP server where you can create read and delete files at will To use these enha
176. et to 1 to test access by the server in general RETURN VALUE 20 Success The return value is a bitmask of the following values O READ user server has read access O WRITE user server has write access e 0 zero no access The following return values are negatives of the values defined in errno 1lib ENOENT The resource was not found e EINVAL The resource name was malformed e g too long or context was NULL or the resource was not a file type SEE ALSO sspec_read sspec_write sspec_seek sspec_tell sspec_close sspec_checkpermissions 58 TCP IP User s Manual sspec addcCGI int sspec addCGI char name void fptr word servermask DESCRIPTION Add a CGI function to the RAM resource list This function is currently only useful for the HTTP server in which case the function is registered as a CGI processor Make sure that SSPEC_MAXSPEC is large enough to hold this new entry PARAMETERS name URL name of the new function for example myCGI cgi fptr Pointer to the function The prototype for this function is int fptr HttpState state There is a specific documented interface that must be used when specifying this type of CGI handler function See the manual for details servermask Bitmask representing valid servers currently only useful with SERVER_HTTP RETURN VALUE 20 Successfully added spec index 1 Failed to add function LIBRARY ZSERVER LIB SEE ALSO sspec_addfs
177. fer size is given by TCP BUF_SIZE 2 The transmit buffer is usually at least 1024 bytes which is considerably larger than the limitation when using the CGI_ SEND return code typically 255 bytes If you try exceeding that limit http _write will never succeed Chapter 4 HTTP Server 197 Step 7 Creating the Resource Tables Web browsers use URLs which are specially formatted strings to refer to resources web pages on the server For example a user may enter http rabbit server admin upload htm1 to retrieve the admin upload html resource from the HTTP server on rabbit_server When the server receives such a request it needs to look up the name open the resource that it refers to and send the contents back to the client CGI functions are no different from other resources as far as the client is concerned The server of course does entirely different things The server needs to have a lookup table defined which translates URLs into the appropriate local type of resource This is the function of the resource table which is also known as the flashspec or ramspec table in Dynamic C parlance The static resource table is a statically defined constant table The dynamic resource table is gen erated at runtime Both types can be used in the same program with dynamic entries overriding static entries with the same URL With this release of Dynamic C there is no need to put anything in either of these t
178. ffer length On return it will be set to the actual length received for a get or unchanged for a put mode Data representation O NETASCI 1 OCTET binary 2 MAIL host Remote host name or NULL to use default BOOTP host hostfile Name of file on remote host or e mail address for mail sock UDP socket to use or NULL to re use BOOTP socket if available RETURN VALUE 0 OK transfer complete 1 Error from remote side transfer terminated In this case ts_addr gt file will be overwritten with a NULL terminated error message from the server 2 Error could not contact remote host or lost contact 3 Timed out transfer terminated 4 sock parameter was NULL but BOOTP socket was unavailable LIBRARY TFTP LIB Chapter 7 TFTP Client 309 310 TCP IP User s Manual 8 SMTP Mail Client SMTP Simple Mail Transfer Protocol is one of the most common ways of sending e mail SMTP is a simple text conversation across a TCP IP connection The SMTP server usually resides on TCP port 25 waiting for clients to connect Define SMTP_ PORT to override the default port num ber Sending mail with the Dynamic C SMTP client library is a simple process demonstrated in the sample program shown in Section 8 3 Dynamic C 9 introduced SMTP authentication described below in Section 8 2 8 1 Sample Conversation The following is a typical listing of mail from the controller me somewhere com to someone somewhereelse com The mail ser
179. file sspec_addfunction sspec_addrootfile sspec_ addvariable sspec_addxmemvar sspec_addxmemfile sspec_aliasspec sspec_addform Chapter 3 Server Utility Library 59 sspec addform int sspec addform char name FormVar form int formsize word servermask DESCRIPTION Adds a form set of modifiable variables to the TCP IP servers object list Make sure that SSPEC_MAXSPEC is large enough to hold this new entry This function is current ly only useful for the HTTP server PARAMETERS name Name of the new form form Pointer to the form array This is a user defined array to hold infor mation about form variables formsize Size of the form array servermask Bitmask representing valid servers currently only useful with SERVER_HTTP RETURN VALUE 20 Success location of form in server spec list 1 Failed to add form LIBRARY ZSERVER LIB SEE ALSO sspec_addfsfile sspec_addfunction sspec_addrootfile sspec_addvariable sspec_addxmemvar sspec_addxmemfile sspec_aliasspec sspec_addfv 60 TCP IP User s Manual sspec addfsfile int sspec addfsfile char name byte filenum word servermask DESCRIPTION Adds a file located in the FS2 filesystem to the RAM resource list Make sure that SSPEC_MAXSPEC is large enough to hold this new entry This function associates a name with the file This creates an alias entry for fs2 file lt n gt Note that all FS2 files are automatically accessible There is
180. fore writing over that buffer In addition the buffer s length is HTTP_MAXBUFFER which limits the size of the string including the null terminator The CGI can return CGI_ SEND for any action code except CGI_ ABORT When the action code is CGI_ EOF there is no more incoming data so strings can be written back to the client indefi nitely the server keeps calling the CGI at CGI_ EOF When the CGI has finished generating all the content it must return CGI_DONE When the server gets the CGI_ DONE return code it closes the client connection normally and ceases calling the CGI 196 TCP IP User s Manual If the CGI has one more thing to write before it is done it can return CGI_SEND_ DONE which combines the CGI_ SEND and CGI_ DONE return codes This can simplify the CGI if it does not have to do much when it first gets the CGI_ EOF action code Using CGI_ SEND return code has some limitations In particular only a limited size of string may be sent to the client on any one call Also a null character cannot be sent to the client because the null is interpreted as the end of the string The null character problem is not usually important since nulls are rarely if ever sent in an HTML document The length limitation is more impor tant since some HTML constructs can be very verbose The http_write function is designed to overcome these limitations http_write writes data from an arbitrary buffer with a higher length li
181. form sub mission If there is only one submit button then there is no need to name it lt FORM gt lt body gt lt html gt Close and complete the form body and entire page Chapter 4 HTTP Server 185 If you have an existing application you can take out the relevant parts of the above and insert them in your existing web page The relevant parts are the enctype multipart form data parame ter in the lt FORM gt element and the lt INPUT type file gt element If you have an existing application that processes the form data submission you will need to rewrite the CGI function that handles the submitted data This is because the enct ype parameter changes the syntax that the browser uses to encode the data In short you will need to rewrite the CGI as a new style CGI as described in Step 6 Writing a CGI Function Having created the HTML file with the upload form it is necessary to import it into your main program so that the HTTP server can present it to the user This can be done using ximport or you can write it directly to the filesystem although initially at least this presents a chicken and egg type problem since you might not have established an upload procedure in the first place 4 6 2 1 Step 6 Writing a CGI Function The CGI function is responsible for processing the form submission data as it comes in from the client browser In addition it generally needs to write some sort of response back to the
182. gi NOTE This is implemented as a macro PARAMETER state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE Null terminated string containing the URL Note that GET style form parameters will be stripped off for example the URL foo cgi A 99 amp D 45 will be returned as foo cgi The GET parameters are available using http _getCond LIBRARY HTTP LIB SEE ALSO http _getAction 232 TCP IP User s Manual http getUserState void http getUserState HttpState state DESCRIPTION Get the user state area of the HTTP server structure This is an area of memory that can be used by the CGI to keep track of its internal state from call to call The size of this areais HITP_USERDATA_ SIZE If that macro is not defined it de faults to zero so use of the http_getUserState macro will result in a compile time error NOTE This is implemented as a macro Example typedef struct myCGIdata define HTTP _USERDATA SIZE sizeof myCGIdata use http 1lib int myCGI HttpState s myCGIdata d d myCGIdata http_getUserState state PARAMETERS state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE Returns the address of the first byte of the user area This should be cast to the appro priate structure type LIBRARY HTTP LIB SEE ALSO http _getAction Chapter 4 HTTP Server 233 http handler void
183. h adduser monitor cat SERVER ANY monitor group NULL sock _init http init for 34 my_io polling http handler void my_io_ polling The first change is the definition of USE_HTTP_BASIC_ AUTHENTICATION This sets up the HTTP server to be able to process this form of authentication If not defined then the server is unable to do this there is little point in setting up any other access controls if the user cannot be verified io state read that _io device Next the user groups are defined In this case we are defining an admin and a monitor group Presumably the admin group has ability to alter the state of the controller but the monitor group can only read its current state The names admin _group and monitor_group are actually defined to be unsigned integer constants with just one bit set out of 16 18 TCP IP User s Manual The web registration of the io_state variable is augmented with some access controls web variables are not strictly resources they are included as parts of other resources however they can be assigned some access controls of their own In this example access to the variable is being set to require basic authentication and the allowable user groups are both of the defined groups with the proviso that the monitor group is to be allowed read only access The last major change is in the main function where some runtime initialization nee
184. h entry can take up a fairly large amount of root storage depending on the mix of filesystems in use Unless you are anticipating a very busy server 4 should be enough If you increase the default value of HITP_MAXSERVERS from 4 you may experience 404 or 503 messages The solution is to increase SSPEC_MAX OPEN Ideally this val ue should be HTTP_MAXSERVERS FTP _MAXSERVERS any special use of zserver 1ib that you create SSPEC XMEMVARLEN Defines the size of the stack allocated buffer used by sspec_readvariable when reading a variable in xmem It defaults to 20 3 2 5 Macros for Control Data Initialization As of Dynamic C 8 50 the following macros are available for building the static tables used by the servers 3 2 5 1 Static Rule Table Resource rules are used to associate access information with resource names The following mac ros define and initialize a static rule table If using a static rule table the dynamically added entries will be searched before the static ones SSPEC FLASHRULES Define this if your application is using static rules You must define this if you want to use the macro SSPEC_RULETABLE START If you define SSPEC_FLASHRULES and you do not need dynamic rules you can define the macro SSPEC_MAXRULES to zero to recover the root memory that would be wasted otherwise SSPEC RULETABLE START SSPEC RULE prefix realm rg wg sm SSPEC MM RULE prefix realm rg wg sm method mimetype SSPEC RULETABLE
185. have been visually emphasized This diagram is essentially the toy application that was described at the start of this chapter It shows the mandatory components for all web enabled applications Later we introduce the other elements of the diagram to show how a fully featured application is built up Application Compile Time Run Time Main Application CGI Initialization Initialization Loop Specifics I O Functions web Variables SS Requests Resources Context Metadata Zserver Resource Manager 1 Static Dynamic gt Resource Resource Table Table s Program Flash Figure 2 2 Minimum components for a web enabled application Chapter 2 Web Enabling Your Application 11 Let us work again from left to right in the Application block To reiterate the Application block represents the coding that you have to do First there is the compile time initialization Taking the super simple example illustrated in Figure 2 2 Dynamic C code is given with the relevant part highlighted in boldface define TCPCONFIG 1 use dcrtcp lib use http 1lib ximport hellowww html hellowww_html SSPEC MIMETABLE START SSPEC MIME html text html SSPEC MIMETABLE END SSPEC RESOURCETABLE START SSPEC RESOURCE XMEMFILE hellowww html hellowww html SSPEC RESOURCETABLE END void main sock anit http_init for http handler The first boldface line is the ximport direct
186. he first official part of the multi part data Most HTTP clients will not provide any prolog data Epilog data is lines of data after the last official part Again HTTP clients do not usually generate it It is always safe to ignore prolog and epilog data since it is usually provided only for non MIME compliant servers Data provided when the action is CGI HEADER isa line of header data provided at the start of each part of the multi part data It is safe for the CGI to ignore header lines since the HTTP server also processes the ones that it needs The CGI is given these header lines so that it can extract useful or customized information if desired The length of the data may be obtained using http _getDataLength The CGI is allowed to overwrite data at the returned area provided that it writes no more than HTTP_MAXBUFFER bytes NOTE This is implemented as a macro PARAMETER state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE Pointer to the first character of data SEE ALSO http getAction Chapter 4 HTTP Server 223 http getDataLength word http getDataLength HttpState state DESCRIPTION Return the length of data that is available It is only valid to call this if it is valid to call http_getData That is if the action code is one of CGI_ DATA CGI_ PROLOG CGI_EPILOG CGI HEADER or CGI_ EOF NOTE This is implemented as a macro PARAMETER state HTTP state p
187. he following return values are negatives of the values defined in errno 1lib ENOENT The resource was not found e EINVAL The resource name was malformed for example too long or con text was NULL or the resource was not a file type SEE ALSO sspec_open sspec_ delete sspec_close 150 TCP IP User s Manual sspec tell long sspec tell int sspec DESCRIPTION Return the current read write offset in the file resource This will be a non negative val ue unless there was an error PARAMETER sspec Open file handle This must be a handle that was returned by sspec_ open RETURN VALUE 20 Offset in the file resource The following return value is a negative of the value defined in errno lib Any oth er negative values indicate an error EBADF The specified handle was not open or invalid SEE ALSO sspec_ close sspec_write sspec_read sspec_tell sspec_open Chapter 3 Server Utility Library 151 sspec write int sspec write int sspec char buf int len DESCRIPTION Write byte s to the given file resource The data is written to the current position then the current position is advanced by the number of bytes written PARAMETERS sspec Open file handle This must be a handle that was returned by sspec_ open buf Buffer from which data is copied len Length of the above buffer RETURN VALUE 0 No data was written because len was zero or because a local buffer is full
188. heck The name should not conflict with the virtual filesystem hierarchy That is it should not start with f s2 A B etc fileloc Location of the beginning of the file The first 4 bytes of the file must represent the length of the file ximport does this auto matically servermask Bitmask representing servers for which this entry will be valid e g SERVER HTTP SERVER_FTP RETURN VALUE 1 Failure 20 Success the location of the file in the dynamic resource list LIBRARY ZSERVER LIB SEE ALSO sspec_ addfsfile sspec_addrootfile sspec_addvariable sspec_addxmemvar sspec_addfunction sspec_addform sspec_aliasspec Chapter 3 Server Utility Library 69 sspec addxmemvar int sspec addxmemvar char name long variable word type char format word servermask DESCRIPTION Add a variable located in extended memory to the RAM resource list Make sure that SSPEC_MAXSPEC is large enough to hold this new entry Currently this function is useful only for the HTTP server PARAMETERS name Name of the new variable This must be unique but this function does not check The name should not conflict with the virtual file system hierarchy That is it should not start with fs2 A B etc Variables appear in directory listing of the root directory however they cannot be opened using sspec_open variable Address of the variable in extended memory type Variable type one of e INTS8 single charac
189. hich when displayed by the browser allows a file to be uploaded to a FAT filesystem mp PORM tag Web Variables Mozilla Build ID 2001090111 EBX includes the Eile Edit View Search Go Bookmarks Tasks Help METHOD attribute which Web Variables is the same as that of the first The current value of io_state is 50 form The Enter anew value if you dare ACTION attribute has po Submit Reset changed to spec ify the CGI File to upload TT AD that to jabbew tin _Browse _ was added to the Upload server s static resource table this is the default CGI provided by the server When the Upload button is clicked http defaultCGI will be called by the server A new attribute is included that specifies the MIME type used to sub mit the form to the server enctype multipart form data This is the MIME type required when the returned document includes files Note that the two forms are being submitted and processed separately Could they be processed as one form Yes but from a modular design perspective it makes sense to keep the form submis sions separate when the purpose of each form is entirely separate You may have noticed that no security was added to protect the filesystem anyone can upload a file that passed the initial user and password protection that limits access to the web page This is probably not the ideal situation Typically there needs to be some limit placed on who is able to write t
190. http lib statement is required in order to bring in the web server The next lines down to the start of the main function are setting up tables that are con sulted by the HTTP server and other libraries in order to do the right thing Finally the main function calls the necessary runtime initialization of the network and the HTTP server It then calls the HTTP server in an endless loop which drives the entire system into motion The html file is ASCII text in HTML syntax which is transferred back to the browser when it is requested Apart from the server adding some header lines the html file is transferred verbatim This markup is merely telling the browser to display Hello WWW as a 1st level heading i e big bold text This is specified by the second line The first line adds a title to the page which most browsers display in the window bar To see this web page on screen the user needs to tell their browser what to get If doing it manu ally they would need to enter something like http 10 10 6 100 hellowww html in the browser s URL entry field The browser strips off the http 10 10 6 100 part of it and sends the rest to the specified host address 10 10 6 100 using a TCP connection to port 80 interpreted from the http part The server gets the hellowww html part which it knows about since it has a page of that name and returns the contents of that file as a response The browser interprets the HTM
191. iable LIBRARY HTTP LIB SEE ALSO http _getAction 230 TCP IP User s Manual http getTransferEncoding char http getTransferEncoding HttpState state DESCRIPTION Return the current encoding of the data which is being provided by the client This is one of the following enumerated values CTE BINARY The default e CTE _7BIT 7 bit safe ASCII e CTE 8BIT 8 bit ASCII e CTE QP Quoted printable e CTE BASE64 Base 64 Of these the CGI is only likely to see CTE_ BINARY since HTTP is an 8 bit protocol and most clients browsers will not bother to encode the data Encoding is only an issue for internet mail which sometimes has to cross interfaces that do not support full 8 bit binary transfers If the CGI detects a transfer encoding that requires non null operation that is CTE QP or CTE _BASE64 then it should either reject the transfer or decode the data as it comes in It is only valid to call this when the action code is CGI_ START CGI_ DATA or CGI_END NOTE This is implemented as a macro PARAMETER state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE Transfer encoding code as documented above LIBRARY HTTP LIB SEE ALSO http _getAction Chapter 4 HTTP Server 231 http getURL char http getURL HttpState state DESCRIPTION Return the URL of the current HTTP client request In a CGI this will usually be some thing like foo c
192. iables in the forms and the actual variables themselves This allows the same variable to be included in multiple forms with different ranges for each form and perhaps be read only in one form and modifiable in another 3 1 10 SSpecFileHandle Structure This structure is used internally by Zserver and is only of interest to developers of new filesys tems which may be incorporated into Zserver 3 2 Constants Used in Zserver lib The constants in this section are values assigned to the fields of the structures ServerSpec and ServerAuth They are used in the functions described in Section 3 5 some as function parame ters and some as return values 3 2 1 ServerSpec Type Field This field describes the resource in the server spec list The possible values are SSPEC_XMEMFILE The data resides in xmem SSPEC_ZMEMFILE The data resides in xmem and is compressed SSPEC_ROOTFILE The data resides in root memory SSPEC_FSFILE The data resides in an FS2 file SSPEC_FATFILE The data resides in a DOS FAT file SSPEC_ FILE The data resides ina file generic type returned by sspec_gettype SSPEC ROOTVAR The data is a variable in root memory for HTTP SSPEC XMEMVAR The data is a variable in xmem for HTTP 38 TCP IP User s Manual SSPEC VARIABLE The data is a variable for HTTP generic type returned by sspec gettype SSPEC_ FUNCTION The data is a function for HTTP SSPEC_FORM A set
193. ibly CGI_ ABORT if there was a stream error PARAMETERS state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE 0 LIBRARY HTTP LIB SEE ALSO http getAction http _skipCGI http _abortCGI http switchcCGI http_write 214 TCP IP User s Manual http getAction char http getAction HttpState state DESCRIPTION Return the current CGI action This should be called only from a CGI function regis tered asa SSPEC_CGI resource in the zserver resource table NOTE This is implemented as a macro You must define the macro USE HTTP UPLOAD if using this macro otherwise you will get a compile time error http _getAction should be called at the top of the CGI function Other http_get functions macros may or may not be valid depending on the action code The following table shows which functions are applicable Table 4 1 Valid Functions per Action Code CGI Action Code Valid Functions Macros Any action code except CGI_ ABORT http_getContext http_getURL http_getState http_setState http_getCond http_setCond http_getUserState http_getSocket http_write http_abortCGI http_skipCGI http_finishCGI http_switchCGI http_getHTTP Version http_getHTTPMethod http_getRemainingLength CGI_START http_getField http_getContentLength http_getContentType http_getContentDisposition http_getTransferEncoding CGI_DATA http_getField http_getContentL
194. ibrary Lib tcpip smtp lib smtp data handler void smtp data _handler int dhnd void dhnd data word opts DESCRIPTION Sets a data handler for generating mail message content This function should be called after calling smtp sendmail etc It overrides any message parameter set by the smtp sendmail call since the message is generated dynamically by the callback function Note you can use the same data handler as used for the FTP library see the ftp data handler description The flags values are numerically equivalent to those of the same meaning for ftp_data_handler The SMTP data handler is only used to generate data not receive it The handler is a function that must be coded according to the following prototype int my_handler char data int len longword offset int flags void dhnd_ data The data handler function must be called with the following parameters data Pointer to a data buffer len The length of the above data buffer This parameter is set to SMTP_MAX DATALEN 256 by default You can override that macro to allow larger chunks offset The byte number relative to the first byte of the entire message stream This is useful for data handler functions that do not wish to keep track of the current state of the data source flags Contains an indicator of the current operation SMTPDH_OUT data is to be filled with the next data to send to the mail server The max imum allowable chun
195. ic ular HTTP server This function is intended for use in CGI applications PARAMETERS state HTTP state pointer as provided in the first parameter to the CGI function dp Pointer to return xmem buffer len Maximum length of the return xmem buffer RETURN VALUE Number of bytes of read or 1 if there was an error LIBRARY HTTP LIB 256 TCP IP User s Manual http sock xfastwrite int http sock xfastwrite HttpState state long dp long len DESCRIPTION HTTP wrapper function for sock_xfastwrite that is for non blocking writes This function can be used to write the contents of an xmem buffer to a socket associated with a particular HTTP server PARAMETERS state HTTP state pointer as provided in the first parameter to the CGI function dp Buffer containing data to be written as an xmem address obtained from for example xalloc len Maximum number of bytes to write to the socket RETURN VALUE Number of bytes of written or 1 if there was an error LIBRARY HTTP LIB Chapter 4 HTTP Server 257 http status int http _status void DESCRIPTION Determine whether the HTTP server is allowing connections RETURN VALUE 0 server is currently disabled non zero server is enabled LIBRARY HTTP LIB SEE ALSO http_handler http_init http shutdown 258 TCP IP User s Manual http switchcGI int http switchCGI HttpState state char newURL DESCRIPTION Tell the HTTP server to switch
196. ic user server mask bit of the server who is performing the listing cwd set to the directory to list The sspec_cd func tion can be used to set this field correctly This struct must be the same instance for all calls in a single direc tory listing sequence 80 TCP IP User s Manual options Listing options This is a bit field that should have a combination of the following flags SSPEC LIST LONG Long format listing else just names SSPEC_LIST_END Close the current directory listing For the long format the template is lt permissions gt 1 lt user gt lt group gt lt length gt lt date gt lt name gt Where permissions is a string of 10 characters in 3 sets of 3 plus one Each set of 3 indicates read write or execute permis sions for the user group and world respectively The 1st char is q if the entry is a directory or otherwise Since Zserver does not really support file owners or groups or execute permissions the 3 sets will be either rw or r or sometimes w The user bits are set according to the current user s access The group bits are set if any other user has access and the world bits are set if any other server has access e 1 is a constant for Unix compatibility e user is the username who owns the file resource Since Zserver does not have the concept of resource own ership this is set to the user ID of the conte
197. ich is displayed in the third column of the form table sspec_setfvdesc form var Maximum in temperature range 60 90 amp deg F This function sets the length of the string representation of the form variable In this case the text box for the form variable in the HTML form will be 5 characters long If the user enters a value longer than 5 characters the extra characters will be ignored sspec setfvlen form var 5 This function sets the range of values for the given form variable The variable must be within the range of 60 to 90 inclusive or an error will be generated when the form is submitted 178 TCP IP User s Manual SEPSC_ pert vrenge Torm ver GO 90 This concludes setting up the first variable The next five lines set up the second variable which represents the current temperature var sspec_addvariable tempnow amp tempnow INT16 d SERVER_HTTP var sspec _addfv form var SSPSC_ SeScinvmeme cem were WCurmeemc Memo 5 sspec setivdesc form var Current temperature in amp deg F sspec setfivlen form var 5 Since the value of the second variable should not be modifiable via the HTML form by default variables are modifiable the following line is necessary and makes the given form variable read only when the third parameter is 1 The variable will be displayed in the form table but can not be modified within the form sspec setfvread
198. id SEE ALSO sspec_setpermissions sspec_getpermissions sspec_ access 76 TCP IP User s Manual sspec close int sspec close int sspec DESCRIPTION Close a file resource This function must be called by servers when they have completed operations on the file otherwise there will be a resource leak and future open calls will fail PARAMETER sspec Open file handle This must be a handle that was returned by sspec_open RETURN VALUE 20 Success The following return values are negatives of the values defined in errno 1lib e EBADF The specified handle was not open or invalid e Other negative values indicate an error in closing the file resource SEE ALSO sspec_read sspec_ write sspec_seek sspec_tell sspec_open Chapter 3 Server Utility Library 77 sspec delete int sspec delete char name ServerContext context DESCRIPTION Delete a resource by name See sspec_open for a detailed description of param eters PARAMETERS name Name of resource context Current server context RETURN VALUE 0 OK The following return value is a negative of the values defined in errno 1lib Any other negative values indicate an error ENOENT The specified resource did not exist SEE ALSO sspec_ mkdir sspec_rmdir sspec_open 78 TCP IP User s Manual sspec dirlist int sspec dirlist int item char line int linelen ServerContext context word options DESCRIPTION
199. id Index in user table RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO sauth_adduser Chapter 3 Server Utility Library 53 sauth setpassword int sauth setpassword int userid char password DESCRIPTION Sets the password for a user PARAMETERS userid Index of user in user table password User s new password RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO sauth_getpassword 54 TCP IP User s Manual sauth setserver int sauth setserver int sauth int server DESCRIPTION Sets whether a user is visible to the specified server s PARAMETERS sauth User index server Server bitmask with bit set to 1 to make this user known to the server If this parameter is zero then the user is visible to ALL servers however it is recommended to pass the value SERVER_ANY in this case RETURN VALUE 0 Success 1 Failure SEE ALSO sauth_getserver Chapter 3 Server Utility Library 55 sauth setusermask int sauth setusermask int userid word userid void authdata DESCRIPTION Set the group access bit s and authorization data for a given user ID PARAMETERS userid User index userid Bitmask of group s of which this user is a member This should be non zero otherwise the user will not have access to any re sources authdata Arbitrary data that can be used by specific servers RETURN VALUE 0 OK 1 Failed userid not
200. if 0 strcepy led1 ledoff gif else strcepy led1 ledon gif cgi redirectto state REDIRECTTO return 0 LA int led2toggle HttpState state Entirely analogous to ledltoggle int led3toggle HttpState state Entirely analogous to ledltoggle int led4toggle HttpState state Entirely analogous to ledltoggle SSPEC RESOURCETABLE START SSPEC_ RESOURCE XMEMFILE index html SSPEC RESOURCE XMEMFILE index shtml index html SSPEC RESOURCE XMEMFILE showsre shtml showsrce shtml SSPEC RESOURCE XMEMFI SSPEC_ RESOURCE XM Ss ty ILE ledon gif ledon gif SSPEC RESOURCE XMEMFILE ledoff gif ledoff gif SSPEC_ RESOURCE XMEMFILE button gif button gif SSPEC_ RESOURCE XMEMFILE ssi c ssi_c SSPEC RESOURCE ROOTVAR ledi led1 PTR16 SSPEC RESOURCE ROOTVAR led2 led2 PTR16 SSPEC RESOURCE ROOTVAR led3 led3 PTR16 SSPEC RESOURCE ROOTVAR led4 led4 PTR16 SSPEC RESOURCE FUNCTION ledltog cgi ledltoggle SSPEC RESOURCE FUNCTION led2tog cgi led2toggle les Jes esl fesl K ty is U L Gali weloloaieil GLE ie SSPEC RESOURCE FUNCTION led3tog cgi led3toggle SSPEC RESOURCE FUNCTION led4tog cgi led4toggle SSPEC RESOURCETABLE END 166 TCP IP User s Manual void main strcpy led1 ledon gif strcpy led2 ledon gif strcepy led3 l
201. il server This can be name or IP address define SMTP SERVER mymailserver mydomain com define USE_SMTP_ AUTH memmap xmem use dcrtcp lib use smtp lib main SOC lt aliastie 5 while ifpending IF DEFAULT IF COMING UP tcp tick NULL ifdef USE SMTP AUTH smtp setauth myusername mypassword endif smtp sendmail TO FROM SUBJECT BODY while smtp mailtick SMTP_PENDING continue if smtp status SMTP SUCCESS printf Message sent n else printf Error sending message n Chapter 8 SMTP Mail Client 313 8 4 Configuration Macros The SMTP client is configured by using compiler macros SMTP AUTH FAIL IF NO AUTH Defaults to undefined This macro was introduced in Dynamic C 9 21 If it is defined the login will fail if authentication fails Otherwise the library will fall back on an unauthen ticated login if authentication fails Prior to Dynamic C 9 21 the login failed if authenti cation failed so the macro is restoring that behavior SMTP DEBUG This macro tells the SMTP code to log events to the STDIO window in Dynamic C This provides a convenient way of troubleshooting an e mail problem SMTP DOMAIN This macro defines the text to be sent with the HELO client command Many mail servers ignore the information supplied with the HELO but some e mail servers require the fully qualified name in this field i e somemachine somedomain com If you ha
202. ile system need to be protected so that only the privi leged group can use the CGI and only the privileged group can write to a defined subset of the file system Let s take this step by step In the main program define a group bit to represent the privileged user s define ADMIN GROUP 0x0002 Groups are assigned one bit out of 16 In this case we select bit 1 Bit 0 or 0x0001 will be used for all other users Next augment the resource table so that the CGI is accessible only to users in ADMIN_ GROUP SSPEC RESOURCETABLE START SSPEC RESOURCE XMEMFILE index html index html SSPEC_ RESOURCE P CGI upload cgi my_CGI newPages ADMIN GROUP 0x0000 SERVER_HTTP SERVER AUTH BASIC SSPEC RESOURCETABLE END The SSPEC_RESOURCE_ P_ CGI is a macro that allows specification of access control parame ters After the usual URL string and function pointer the next parameters are e newPages this is the so called realm of the CGI resource This is not particularly signifi cant except that it notifies the client that this is a restricted resource and that a userid password will be required The user sees this string when prompted for his or her credentials ADMIN GROUP this was the group defined above In this context it applies to the read access rights To read this resource that is to use the CGI the user needs to be in this group Chapter 4 HTTP Server 199 e 0x0000 this is also a group bit p
203. in UTC The handler is only recognized if FTP_ EXTENSIONS is defined PARAMETERS fd File descriptor for the currently opened file RETURN VALUE The number of seconds that have passed since January 1 1980 The default handler al ways returns zero The number of seconds will be converted to a date and time value of the form yyyymmddhhmmss Chapter 6 FTP Server 289 ftp dflt delete int ftp dflt delete char name int uid int cwd DESCRIPTION The default handler does not support the delete command It simply returns the error code for an unauthorized user The delete handler is only recognized by the server if FTP_ EXTENSIONS is defined It is called when the DELE command is received The given file name possibly relative to cwd should be deleted PARAMETERS name Pointer to the name of a file uid The currently logged in user cwd The current directory RETURN VALUE 0 File was successfully deleted FTP ERR_NOTFOUND File not found FTP ERR _NOTAUTH Unauthorized user FTP _ERR_BADMODE Requested option 2nd parameter is not supported FTP ERR_UNAVALL Resource temporarily unavailable 290 TCP IP User s Manual 6 3 API Functions The API functions described here initialize and run the FTP server ftp dflt is auth int ftp dflt_is auth int spec int options int uid DESCRIPTION Determine amount of access to a file If the FTP anonymous user has been set then also checks that options
204. in a form when SSPEC_ FORM is the type of data addr Address of function or variable when SSPEC_ FUNCTION SSPEC CGI orSSPEC VARIABLE is the type of data Address of form struct for SSPEC_ FORM vartype Type of variable when SSPEC_ VARIABLE is the type of data or length of data when FILE is the type of data and the length is needed e g a root file For SSPEC_HARDLINK contains the sspec index number ofahttp flashspecorserver_ spec entry format sprintf format for a variable or form title for a form or base address for SSPEC_ROOTFILE For SSPEC_LINK points toa string containing the linked to resource name perm Permissions associated with this resource If realm subfield is NULL then the permissions table is consulted as for filesystem re sources Note this field used to be char for the realm string only Programs that used this feature need to be modified This structure is detailed under ServerPermissions There are some other fields that are conditionally included if HTTP forms are in use These are not generally relevant See the library source for details 34 TCP IP User s Manual 3 1 3 ServerAuth Structure This structure defines a global array that is a list of user name password pairs ServerAuth server_auth SAUTH_MAXUSERS Throughout this manual this array is called the user table The fields in the ServerAuth struct are manipulated using the sauth_ functions The description below is for
205. ined by default only if no filesystem libraries have been used Even if a filesystem library has been used this can still be explicitly defined by the user When this is defined then the console will not save configuration information to the filesystem and no filesystem function calls will be included CON SP _RDBUF SIZE Size of the slave port read buffer Defaults to 255 CON SP _WRBUF SIZE Size of the slave port write buffer Defaults to 255 CON TIMEOUT Adjusts the number of seconds that the console will wait before cancelling the current command The timeout can be adjusted in user code in the following manner state gt timeout con _set timeout CON TIMEOUT This is useful for custom user commands so that they can indicate when something meaningful has happened on the console such as some data being successfully trans ferred Chapter 11 General Purpose Console 371 CON VAR BUF SIZE Adjusts the size of the variable buffer in which values of variables can be stored for use with the HTTP server It is allocated in xmem space Defaults to 1024 bytes CON VERSION MESSAGE This defines the version message to display when the HELP command is issued with no parameters It is not defined by default so has no default value 372 TCP IP User s Manual 11 9 Sample Program The sample program Samples zconsole tcpipconsole c demonstrates many of the features of zconsole 1lib Among the features this application suppo
206. ing assuming that a FAT partition already exists on the serial flash How to create the initial filesystem is discussed in the Dynamic C Module document titled Compact FAT File system The application now supports uploading files to the FAT but we have yet to give the user any way to actually do it That involves changing the HTML page lt HTML gt lt HEAD gt lt TITLE gt Web Variables lt TITLE gt lt HEAD gt lt BODY gt lt H1 gt Web Variables lt H1 gt lt P gt The current value of io state is lt z echo io_ state gt lt P gt lt z if error io state gt lt P gt Sorry you were not authorized to perform an update lt P gt lt z gt lt FORM ACTION index html METHOD POST gt lt P gt Enter a new value if you dare lt P gt lt INPUT TYPE text NAME io0 state SIZE 5 VALUE lt z echo Sio state gt gt lt INPUT TYPE submit VALUE Submit gt lt INPUT TYPE reset VALUE Reset gt lt FORM gt lt BR gt lt FORM ACTION upload cgi METHOD POST enctype multipart form data gt lt TABLE BORDER 0 CELLSPACING 2 CELLPADDING 1 gt lt TR gt lt TD ALIGN RIGHT gt File to upload lt BR gt to A new htm lt TD gt lt TD gt lt INPUT TYPE FILE NAME A new htm SIZE 50 gt lt TD gt lt TR gt lt TABLE gt lt INPUT TYPE SUBMIT VALUE Upload gt lt FORM gt lt BODY gt lt HTML gt 24 TCP IP User s Manual The text in boldface is the description of a new form w
207. ing in the first FAT partition A with a filename starting with new is protected according to the remaining parameters This includes any file in the root directory whose name starts with new or any file in any subdirectory of the root directory where the subdirectory name starts with new newPages this is the realm string assigned to these files This is the same as the CGI realm but need not be e OxFFFF this is the user groups who are allowed read access In this case everyone is allowed ADMIN GROUP this is the writable group only the one defined for the CGI is allowed SERVER_HTTP only the HTTP server can access SERVER AUTH NONE this is only relevant when the resource is being read directly by the client When the file is written via the CGI the CGI has already authenticated the user in its own way and doesn t need to re authenticate In this example no authentication is required for retrieval read only of the file e NULL this is an additional parameter that is not relevant to this discussion By default every other file in the filesystem s that is not covered by this rule is denied write access In general a rule is only required when it is desired to permit write access not deny it 200 TCP IP User s Manual Step 10 Create Set of User IDs The last step is to actually define the users This must be done at runtime using the sauth_ functions The following c
208. int cwd char buf long mdtm int fd int delete char name int uid int cwd FTPhandlers If you always provide all your own handlers then you can define FTP NODEFAULTHANDLER to eliminate the code for the default handlers The han dlers must be written to the specification described in Section 6 2 2 To use a default handler leave the field NULL If you pass a NULL handlers pointer then the all default handlers will be used The defaults access the server spec list which is set up using the zserver functions sspec_addxmemfile sauth_adduser etc PARAMETERS handlers NULL means use default internal file handlers Otherwise you must supply a struct of pointers to the various file handlers open read write close getfilesize list To not override a particular handler leave it NULL in the structure LIBRARY FTP SERVER LIB SEE ALSO ftp tick 292 TCP IP User s Manual ftp load filenames int ftp load filenames void DESCRIPTION This function is used in conjunction with the FTP_USE_FS2 HANDLERS macro It loads the data structure i e the server spec list that keeps track of the association of filenames to file locations in the file system The information is loaded from the User block from the offset given in FTP _USERBLOCK_ OFFSET The function removes any entries from the server spec list that are not FS2 files RETURN VALUE 0 Success 1 Failure possibly due to the filenames ha
209. ion should be passed to this function Up to SSPEC_ MAX PARTITIONS can be registered This number can be changed indirect ly by defining SSPEC_ MAX FATDRIVES before use zserver 1ib This de faults to one drive and the number of partitions is set to 4 times this number hence the default allows up to four partitions NOTE It is NOT necessary to call this function if you called sspec_ automount SSPEC MOUNT FAT since that function does all the necessary initializations for a single drive PARAMETERS partno Partition number to register This starts at 0 corresponding to the 7 2 mount point 1 for B etc pt Pointer to fat_part data structure returned by fat MountPartition etc To unregister a partition pass NULL for this parameter Note attempted access to an unregis tered partition generally results in an error code of ENXIO RETURN VALUE 20 Success ENXIO partno outside the allowable range of 0 SSPEC_MAX PARTITIONS 1 LIBRARY ZSERVER LIB SEE ALSO fat _EnumDrive fat _EnumPartition fat_MountPartition sspec_automount sspec_fatregistered 82 TCP IP User s Manual sspec fatregistered fat part sspec fatregistered int partno DESCRIPTION Test whether a FAT partition has been registered with Zserver PARAMETER partno Partition number to test This starts at 0 corresponding to the A mount point 1 for B etc RETURN VALUE NULL Not registered Otherwise Reg
210. ion that will be called to generate all the necessary response Note that a complete response requires a small amount of header informa tion to be prefixed to the actual resource The HTTP server usually takes care of this however CGIs sometimes need to generate the header themselves 1 This is a necessary optimization There may be hundreds of individual users however the majority of these would be considered to be in a single class with that class giving equal access to all its members Considering the class i e group as the entity that is requesting a resource reduces the amount of information that needs to be stored TCP IP User s Manual Referring to the diagram in Figure 2 1 you can see that there are several arrows leading in and out of the HTTP server block These represent lines of communication and the arrow heads indicate the usual direction of data flow or for function calls who calls whom 2 3 3 HTTP Block Subcomponents The inner circles represent subcomponents of the server The first of these RabbitWeb is a new add on module available starting with Dynamic C 8 50 RabbitWeb is an extension to C language syntax to simplify presentation of C language objects variables structures to a browser Rabbit Web allows you to write web pages in a special scripting language The script makes it easy to generate HTTP which is the format expected by the browser In addition the script allows the contents of
211. is HTML FORM_TEXT which is a standard text entry box This line sets the type to HTML FORM _PULLDOWN which is a pull down menu sspec setfventrytype form var HTML FORM PULLDOWN Finally this code sets up the last variable Note that it is a float so FLOAT3 2 is given in the sspec_addvariable call The last function call is sspec_setfvfloatrange instead of sspec_setfvrange since this is a floating point variable var sspec addvariable humidity amp humidity FLOAT32 aie SERVER HTTP j var sspec _addfv form var sspec_setfvname form var Humidity sspec setfvdesc form var Target humidity between 0 0 and 1 0 sspec setfvlen form var 8 sspec_setfvfloatrange form var 0 0 1 0 ole These calls create aliases in the dynamic resource table for the HTML form That is the same form can now be generated by requesting index htm1 or Note that sspec_aliasspec should be called after the form has already been set up The aliasing is done by creating a new entry in the resource table and copying the original entry into the new entry Note that aliasing can also be done for files and other types of server objects sspec_aliasspec form index html p sspec aliasspec form These lines complete the sample program They initialize the TCP IP stack and web server and run the web server sock init weto dmat A while 1 http handler
212. is function takes two parameters The first is on or off to turn this feature on or off The second parameter is optional and specifies the intended interface ETHO or ETH1 Only non PPPoE Ethernet may be used for ping configuration con_set_icmp_config_reset Normally when an interface has been configured via a directed ping packet further configuration via a directed ping packet is disabled until the next power cycle This function allows the inter face to be configured via a ping packet again A command that uses this function takes an optional interface argument ETHO or ETH1 con_set_ip This function changes the IP address of the board A command that uses this function takes one parameter the new IP address in dotted quad notation e g 192 168 1 112 350 TCP IP User s Manual con_set_param This function sets the parameter for the current I O device Depending on the I O device this value could be a baud rate a port number or a channel number A command that uses this function takes one parameter the value for the I O device parameter con_set_mail_from This function sets the return address for all e mail messages This address will be added to the out going e mail and should be valid in case the e mail needs to be returned A command that uses this function takes one parameter the return address con_set_mail_server This functions identifies the SMTP server to use A command that uses this function tak
213. is returned SEE ALSO sspec_cd Chapter 3 Server Utility Library 119 sspec read int sspec read int sspec char buf int len DESCRIPTION Read the next byte s from the given file resource PARAMETERS sspec Open file handle This must be a handle that was returned by sspec_open buf Buffer into which data is copied len Length of the above buffer If len is zero then the return value will be the minimum number of characters that could be read at the current position which is usually at least 1 except at EOF 0 Thus this function can be used to test for end of file EOF that is if sspec_read sspec NULL 0 0 is TRUE then EOF has been reached in the file identified by sspec RETURN VALUE 0 No data is currently available If the 1en parameter was zero then a return value of zero definitely means end of file has been reached If len gt 0 there may be data avail able in the future e g because the underlying filesystem is socket based and this host has read all available data but the socket is still open to receive more data 1 1en the specified number of characters has been copied to the supplied buffer and the current file position has been advanced by that many bytes Possibly less than len bytes may be read in which case the server should test for EOF gt len no data was copied because the underlying filesystem is unable to return a par tial record and maintain its current position Th
214. isible from the HTTP server This would be more relevant is there was another server such as FTP running concurrently 1 In this example we also choose to use a rule table This is not strictly necessary since no filesys tem is in use The alternative is to use a different form of initializing the static resource table namely by using the SSPEC_RESOURCE_P_XMEMFILE macro which allows permission information to be stored in the static table instead of in the rule table See Section 3 2 5 3 Chapter 2 Web Enabling Your Application 19 SERVER_AUTH_BASTIC indicates that the server should use basic authentication when the browser calls for this resource Note that Zserver does not enforce the method of authentication it only stores the recommended method in the rule table Any enforcement of authentication requires the co operation of the server since each different type of server may have widely differ ent means of implementing the same type of authentication Rest assured that the HTTP server and other servers provided with Dynamic C always enforce the suggested authentication method The final NULL parameter allows some arbitrary data to be stored in the rule table entry This data is available to the server It is not currently used by any of the servers in Dynamic C but it may be useful if you implement your own server Now let s turn to the user ID initialization sauth_setusermask sauth_adduser admin dog SERVER AN
215. isible to all servers gt 0 Visible to select servers One bit is set for each server that knows about this user 1 Failure for example sauth is an invalid index into the user table SEE ALSO sauth_setserver 48 TCP IP User s Manual sauth getuserid int sauth getuserid char username word server DESCRIPTION Gets the user index for a user PARAMETERS username User s name If this name is not found then the list is re scanned looking for an entry with an empty user name and a password that matches username The second pass is only done for servers that allow password only matching Such servers must be speci fied by defining a symbol SERVER_PASSWORD_ ONLY to bea bitmask of such servers server Server s for which we are looking up Use SERVER_ ANY if not concerned with the server mask RETURN VALUE 20 Success index of user in the user table 1 Failure LIBRARY ZSERVER LIB Chapter 3 Server Utility Library 49 sauth getusermask int sauth getusermask int userid word groupbits void authdata DESCRIPTION Get the group access bit s and or authorization data for a given user ID PARAMETERS userid User index groupbits Pointer to bitmask that will be set to group s of which this user is a member If NULL this information is not retrieved authdata Pointer to void that is set to arbitrary server data If NULL this information is not retrieved RETURN VALUE 0 OK 1 Failed
216. istered and this is the fat_ part pointer SEE ALSO fat _EnumDrive fat _EnumPartition fat_MountPartition sspec_ automount sspec_fatregister Chapter 3 Server Utility Library 83 sspec findfv int sspec findfv int form char varname DESCRIPTION Finds the index of a form variable in a given form PARAMETERS form spec index of the form in which to search varname Name of the variable to find RETURN VALUE 1 Failure 20 Success the index of the form variable in the array of type FormVar LIBRARY ZSERVER LIB SEE ALSO sspec_addfv 84 TCP IP User s Manual sspec findname int sspec findname char name word server DESCRIPTION Find the spec entry with a name field that matches the given name and is allowed with the specified server s Note that a leading slash in the given name and or in the re source name is ignored for backwards compatibility PARAMETERS name Name to search for in the resource list server The server making the request e g SERVER HTTP RETURN VALUE 1 Failure 20 Success spec index The special value SSPEC_ VIRTUAL is returned if the name refers to part of the virtual filesystem hierarchy In this case the server mask is not con sulted SSPEC_VIRTUAL is not a valid handle for other functions LIBRARY ZSERVER LIB SEE ALSO sspec_ findnextfile 85 Chapter 3 Server Utility Library sspec findfsname int sspec findfsname byte filenum wor
217. ive This tells the compiler to include the specified file in the program flash and make it accessible via the he 1lowww_htm1 constant In the dia gram the arrow from compile time initialization to program flash represents this inclusion In most cases you would be including more than just one file The three lines starting with SSPEC_MIMETABLE START are initialization statements for the MIME table In this case there is a single mapping from resources that end with html to a MIME type of text html All MIME types are registered with the relevant standards body and must be entered correctly so that the browser does not get confused text html is the registered MIME type for HTML The next three lines starting with SSPEC_RESOURCETABLE START set up the static resource table Again this contains a single entry that associates the resource name hellowww html with the file that was ximported on the first line Note that the resource name suffix html matches the first parameter of the SSPEC_ MIME entry Although not directly indicated on the diagram the other compile time initialization that is always required is the use of the appropriate libraries In this case the first three lines create a default TCP IP configuration TCPCONFIG 1 and bring in the networking and HTTP libraries Note that http 1ib automatically includes zserver 1ib Back in the Application block of the diagram we move right and consider the ru
218. k configuration options 2 use lt filesystem s of choice gt and specify the file system configuration 3 define USE_HTTP_UPLOAD 4 use http lib 5 Create an initial web page with a form asking for the file s to be uploaded The main require ment is that you specify enctype multipart form data inside the lt FORM gt tag s 6 Write a CGI function if not using the default one provided 7 Create an initial resource table containing at least an entry for each of the above two resources the web page and the CGI 8 Create a list of content type mappings i e the MIME table 9 Create rules which limit the upload facility to select user groups 10 Create a set of user IDs 11 In the main program call http handler ina loop Step 1 Specify Network Configuration To make use of HTTP upload you need to perform the usual inclusion and configuration of the networking library dcrtcp 1lib At its simplest it is two lines of code at the top of your main program define TCPCONFIG 1 use dertcp lib This specifies that the default TCP networking configuration is to be used If you want to change the default networking configuration first read the comments at the top of tcp _config 1lib HTTP upload usually requires at least two additional libraries to be included a file system library and http 1ib itself A file system is required otherwise the uploaded file has nowhere to go although you can write a
219. k of data is specified by len The data must not contain the sequence lt CRLF gt lt CRLF gt since that will confuse the process SMTPDH_ABORT end of data error encountered dur ing SMTP operation The mail was probably not delivered dhnd data The pointer that was passed to ftp_data_handler 316 TCP IP User s Manual PARAMETERS dhnd Pointer to data handler function or NULL to remove the current data handler dhnd data A pointer that is passed to the data handler function This may be used to point to any further data required by the data handler such as an open file descriptor opts Options word currently reserved set to zero RETURN VALUE The return value from this function should be the actual number of bytes placed in the data buffer or 1 to abort If 0 is returned then this is considered to be the end of data You can write up to and including len bytes into the buffer but at least one byte must be written otherwise it is assumed that no more data is following For SMTPDH_ ABORT the return code is ignored SEE ALSO smtp sendmail smtp _sendmailxmem smtp_mailtick EXAMPLE The program Samples tcpip smtp smtp_dh c makes use of this function Chapter 8 SMTP Mail Client 317 smtp mailtick int smtp mailtick void DESCRIPTION Repetitively call this function until e mail is completely sent RETURN VALUE SMTP_SUCCESS e mail sent SMTP_PENDING e mail not sent yet call smt
220. l my_app shtml SSPEC RESOURCE CGI upload cgi http defaultCGI SSPEC RESOURCE CGI update cgi VarUpdateCGI SSPEC RESOURCETABLE END void my_io polling void void main int rc io state 42 sspec addrule index html Pet admin_group monitor_group 0 SERVER_HTTP SERVER AUTH BASIC NULL sauth_setusermask sauth_ adduser admin dog SERVER ANY admin group NULL sauth_ setusermask sauth_ adduser monitor cat SERVER ANY monitor group NULL qa rc sspec_automount SSPEC_MOUNT_ANY NULL NULL NULL if rc printf Failed to initialize rc d n Proceeding anyway n rc sock_init http_init for ee f my_io polling http handler Chapter 2 Web Enabling Your Application 27 The first change is the removal of the macros we added for FAT and also the removal of use statements for the FAT library and the associated serial flash driver library As with the sample in the last section this code assumes that a valid filesystem partition exists on the target board in this case it s an FS2 partition In the simplest case which is one FS2 partition on the secondary flash bringing in s2 1ib and then mounting the filesystem with a call to sspec_automount is all that is required For more information on FS2 refer to the Dynamic C User s Manual The next change is the define of the user groups Each user group has to be explicitly given a
221. le is lost forever or until the next reboot The CGI_ABORT code can happen at any time so the CGI must handle it if it ever uses leakable resources If you are alert you noticed that CGI_ ABORT may be called when there is no open handle We must guard against the possibility of trying to close an invalid handle since it may happen to belong to another active CGI We can do this by ensuring the value in the cond variable is 1 if the handle is not open 192 TCP IP User s Manual Minimum Required Functionality of CGI All the above code is pulled together with the proper tests and comments on the additional code define COND HANDLE 0 cond variable for storing the handle int my_CGI HttpState s int handle Following block ensures that the first time http_getState is zero we set the handle to 1 if http _getState s 0 http setState s 1 http setCond s COND HANDLE 1 switch http getAction s case CGI START if http _getField s 0 printf Found a file to upload n http setCond s COND HANDLE sspec open http getField s http getContext s O WRITE O CREAT O TRUNC 0 if http _getCond s COND HANDLE lt 0 http skipCGI else http skipCGI s break case CGI DATA handle http _getCond s COND HANDLE sspec write handle http getData s http getDataLength s break case CGI END handle http _getCond s COND HANDLE sspec_close
222. le system and their file sizes A command that uses this func tion takes no parameters con_list_variables This function displays the names and types of all variables A command that uses this function takes no parameters con_loginname This function stores an identifier that will be remembered across power cycles with battery backed RAM The existence of the identifier will be used to prompt the user of a new console ses sion Before console access to the controller is allowed a valid identifier must be entered in response to the prompt A command that uses this function takes one parameter an identifier that will be used as the login name 348 TCP IP User s Manual con_loginpassword This function stores an identifier that will be remembered across power cycles with battery backed RAM The existence of the identifier will be used to prompt the user for a password after a login name has been entered Before console access to the controller is allowed a valid identifier must be entered in response to the prompt A command that uses this function takes no parameters on the command line but requires a series of user inputs in response to prompts In the following screen shot the command is named login password and is typed in by the user All other screen text shown here was printed by Zconsole Tera Term COM2 YT Me x File Edit Setup Control Window Help BasicConsole Version 1 60 ogin passwor password ew
223. letely different device and filesystem The term for such directory entries is mount point Note the distinction between this naming convention and the one used by PC DOS and similar operating systems In DOS you have to explicitly indicate the device by prefixing the file name For example C index htm and A index htm are different files on different devices On Unix you create two mount points in the root directory backup and production for example Then the above mentioned files are known as backup index htm and production index htm This may seem like a fine distinction however it matches better with the naming convention used by HTTP i e the URL It also offers greater flexibility with regards to naming devices Zserver does not currently allow arbitrary mount point names like Unix Instead there is an estab lished convention for each filesystem If FS2 is in use then there is a mount point called fs2 If the FAT filesystem is in use then one or more mount points called A B C etc are cre ated Since Zserver is the resource manager it takes responsibility for mapping the various filesystems and resource types into a single unified API This API not only takes care of the detailed differ ences between the various filesystem APIs but also allows some functions to be emulated that are not natively supported by the underlying filesystem In addition to the resource storage and filesystem the reso
224. list which is set up using sspec_addxmemfile sauth_adduser etc The default file handlers are used when NULL is passed to the initialization function ftp_init 6 2 1 Replacing the Default Handlers The FTPhandlers structure contains function pointers to the file handlers This structure may be passed to ftp init to selectively replace the default file handlers You may provide a NULL pointer for handlers that you do not wish to override If you have defined FTP EXTENSIONS then there are an additional two function pointers that should be initialized typedef struct int open int read int write int close long getfilesize int dirlist int cd int pwd ifdef FTP EXTENSIONS long mdtm int delete endif FTPhandlers Starting with Dynamic C 7 30 all FTP server instances share the same set of data handlers Before this release there was a separate copy of the handler pointers for each instance of the server This change does not affect your existing application except to slightly reduce memory usage This change does add flexibility because it gives any file handler the ability to call any other file handler In particular ftp _df1t_list may now call ftp dflt_getfilesize to get the file s size 6 2 2 File Handlers Specification Function descriptions for the default handlers are detailed in this section Additional information is provided in these desc
225. ll the details for us Without RabbitWeb we have to do the work ourselves Fortunately the new style CGIs make this job easier A detailed descrip tion of writing a new style CGI is given in Section 4 6 HTTP File Upload As we saw in Section 2 7 there is a CGI in http lib that processes file uploads to a filesystem If you study and understand Section 4 6 and the code in http_defaultCGI you will be able to write a new style CGI that will process the form that is submitted when io_state is changed 28 TCP IP User s Manual Since we are not using RabbitWeb and have changed from using FAT to FS2 the HTML page must be changed As before all changes are in boldface lt HTML gt lt HEAD gt lt TITLE gt Web Variables lt TITLE gt lt HEAD gt lt BODY gt lt H1 gt Web Variables lt H1 gt lt P gt The current value of io state is lt echo var io state gt lt P gt lt FORM ACTION update cgi METHOD POST enctype multipart form data gt lt P gt Enter a new value if you dare lt P gt lt INPUT TYPE text NAME io state SIZE 5 VALUE lt echo var io state gt gt lt INPUT TYPE sSubmit VALUE Submit gt lt INPUT TYPE reset VALUE Reset gt lt FORM gt lt BR gt lt FORM ACTION upload cgi METHOD POST enctype multipart form data gt lt TABLE BORDER 0 CELLSPACING 2 CELLPADDING 1 gt lt TR gt lt TD ALIGN RIGHT gt File to upload lt BR gt to A new htm lt TD gt lt TD gt
226. llows an application to further process the files 1S0 20 42 Specifies no action except that the server send an OK reply It does NOOP 200 not affect any parameters or previously entered commands Chapter 6 FTP Server 299 Table 6 2 Recognized FTP Server Commands ae Possible Command Description Reply Codes Password for the user name sent in clear text It is accepted only Hers after USER returns code 331 240 330 Requests a passive open on a port that is not the default data port PASV The server responds with the host and port address on which itis 227 452 listening Changes the data port from the default port to the port specified in PORT the command s argument The argument is the concatenation ofa 200 32 bit internet host address and a 16 bit TCP port address PWD Prints the working directory name 257 Closes the control connection If a data transfer is in progress the GUI connection will not be closed until it has completed A RETR Transfers a copy of the file specified in the pathname argument 150 226 from the server to the client 425 550 213 250 SIZE Returns the size of the specified file 450 550 Stores a file from the client onto the server The file will be 150 226 250 STOR overwritten if it already exists at the specified pathname or it will 425 450 be created if it does not exist 452 550 STRU Confirms the supported structure of a file Only fil
227. locat ed in root data space CON DHCP ACQUIRE RETRY TIMEOUT Defaults to 120 seconds If DHCP is enabled then Zconsole will maintain the DHCP lease This macro specifies the number of seconds after which a DHCP lease has been dropped that the board will attempt to reacquire the lease Note that in the normal course of operation a lease will never be dropped Generally that will only happen if the DHCP server is inoperable for an extended period of time subject to the lengths of the leases that the DHCP server issues 370 TCP IP User s Manual CON HELP VERSION This macro should be defined if the developer wants a version message to be displayed when the HELP command is issued with no parameters If this macro is defined then the macro CON VERSION MESSAGE must also be defined CON INIT MESSAGE Defines the message that is displayed on all Zconsole I O methods upon startup Defaults to Console Ready r n CON MAIL BUF SIZE Maximum length of a mail message Defaults to 1024 CON MAIL FROM SIZE Maximum length of mail from address to NULL terminator Default to 51 CON MAIL SERV SIZE Maximum length of mail server name and NULL terminator Defaults to 51 CON MAX NAME Default is 10 maximum number of characters for a login name This value must be equal to or less than CON_CMD_DATA_ SIZE CON MAX PASSWORD Default is 10 maximum number of characters for a login password CON NO FS SUPPORT This macro is def
228. ly if this results in a NULL MIME type pointer is the http_types table consulted See sspec_open for a detailed description of the parameters PARAMETER name Name of the resource context Current server context RETURN VALUE Pointer to the appropriate table entry MIMETypeMap is defined as typedef struct char extension 10 File extension or suffix char type SSPEC MAXNAME MIME type e g text html int fptr Server specific processing e g SSI MIMETypeMap A valid pointer is always returned If the appropriate table entry cannot be located by the resource s extension or using a rule see sspec_addrule then the first table entry is returned SEE ALSO sspec_addrule 102 TCP IP User s Manual sspec getname char sspec getname int sspec DESCRIPTION Returns the name of the spec entry represented by the sspec index This only works for RAM and flash table entries PARAMETERS sspec spec index RETURN VALUE NULL Failure NULL Success pointer to name string LIBRARY ZSERVER LIB Chapter 3 Server Utility Library 103 sspec getpermissions int sspec getpermissions int sspec char realm word readgroups word writegroups word servermask word method MIMETypeMap mimetype DESCRIPTION Get the permission access control attributes of a resource Except for sspec all parameters are pointers to variables that will be set to the appro priate re
229. match CON _ERR_CANCELRESET Reset cancelled CON _ERR_BADVARTYPE Bad variable type CON_ERR_BADVARVALUE Bad variable value CON_ERR_NOVARSPACE Out of variable space CON_ERR_VARNOTFOUND Variable not found CON_ERR_STRINGTOOLONG String too long CON_ERR_NOTAFILE Not a file CON _ERR_NOTAVAR Not a variable CON_ERR_COMMANDTOOLONG Command too long CON _ERR_BADIPADDRESS Bad IP address CON_ERR_INVALIDPASSWORD Invalid Password CON_ERR_BADIFACE Bad interface name CON_ERR_BADNETWORKPARAM Error setting network parameter 11 4 2 2 Custom Error Messages Developers can create their own error messages by following the format of the default error mes sages The error code numbers should be greater than 1 000 to save room for expansion of built in error messages define NEW ERROR 1001 const ConsoleError console errors CON STANDARD ERRORS includes all default error messages NEW ERROR Any error message I want The default error messages should be included in console errors along with any custom error messages that are used since the commands that come with Zconsole 1ib each expect their own particular error message Chapter 11 General Purpose Console 355 11 5 Zconsole I O Interface Multiple I O methods are supported as well as the ability to add custom I O methods An array of ConsolelIO structures must be define
230. mic RAM table To access the file resource the return value from this function must be passed to other functions such as sspec_read A few functions do not work with resources opened with this function These cases are documented with the function NOTE When the application has finished accessing the resource it must be closed using sspec_close This must be done because there is a limited amount of stor age for maintaining the necessary file handles PARAMETERS name Resource name as a NULL terminated string This name is as sumed to be relative to context gt cwd if it does not begin with a character Otherwise the name is assumed to be relative to context gt rootdir Note that the name string can contain e 99 and directory components These will be interpreted as same directory and one level up as is customary If com ponents are included the resulting name cannot be above or out side the root directory specified in context gt rootdir 116 TCP IP User s Manual context Additional context information The ServerContext structure is set up by the caller It has the following fields typedef struct int userid word server User ID of the current user or 1 if not applicable Server id e g SERVER_HTTP char rootdir Root directory Usually if the whole namespace is to be accessible Otherwise may be e g A to re
231. mit on any one call and returns either zero meaning that all data was successfully queued or it may return CGI_MORE if it could not write the data Either all or none of the data will be written respectively In the case that none was written the CGI returns the CGI_MORE return code to the HTTP server The CGI will then be called back with an action code of CGI_ CONTINUE where it should retry the failed http write call Ifhttp write returns zero it can be called again immediately with more data or the CGI can return zero to the HTTP server Otherwise the CGI function will generally need to remember what it was up to and retry the http write on the next call The following code illustrates use of http_write static const char a very long html fragment 512 bytes case CGI_ END return http write s a_very_long html fragment strlen a_very long html fragment case CGI CONTINUE if was writing that _long fragment return http _write s a_very long html fragment strlen a_very long html fragment break The details of determining which write was in progress have been glossed over Basically you would have to use a cond variable to keep track of which http_write was in progress if there is more than one possibility There is a limit to the amount of data that http _write can possibly write on any given call This limit is set by the HTTP server socket transmit buffer size This buf
232. mited to the size HTTP MAXBUFFER If you need larger strings you should either increase HTTP _MAXBUFFER which will use more root RAM or switch to using a CGI function 4 5 2 2 CGI Feature Ssi c also demonstrates the Common Gateway Interface CGI is a standard for interfacing exter nal applications with HTTP servers Each time a client requests an URL corresponding to a CGI program the server will execute the CGI program in real time For increased flexibility a CGI function is responsible for outputting its own HTTP headers Information about HTTP headers can be found at http deesse univ lemans fr 8003 Connected RFC 1945 and many other web sites and books In the Ssi shtml file this line creates the clickable button viewable from the browser lt TD gt lt A HREF ledltog cgi gt lt img SRC button gif gt lt A gt lt TD gt When the user clicks on the button the browser will request the led1ltog cgi entity This causes the HTTP server to examine the contents of the http _flashspec structure looking for ledltog cgi It finds it and notices that ledltoggle needs to be called The led1ltoggle function changes the value of the 1ed1 variable then redirects the browser back to the original page When the original page is reloaded by the browser the LED image will have changed states to reflect the user s action This sample demonstrates the so called old style CGI New style CGIs are easier to write
233. most always need to be a few ximport files but this can be limited to a few kilobytes total 2 Runtime initialization Your main function needs to call some specific library functions once only when it starts e sock init This is always mandatory It initializes the TCP IP networking system sspec_ automount This is optional It initializes the available filesystems FS2 and or FAT for use by the resource manager Zserver e http _init This is mandatory It initializes the HTTP server e Various functions for setting up a user ID table the rule table and or the dynamic resource table These are optional but would be used in the majority of applications The user ID table can only be initialized at run time unlike the other tables that may at least partially be initialized at compile time 3 Main loop The final code in the main function continuously calls http handler and possibly other functions This is mandatory since it allows the HTTP server to process requests from the network Other functions may be specific to your application For example you may need to poll an I O device in order to obtain best performance Chapter 2 Web Enabling Your Application 7 4 Application specifics and I O This is really your part of the application or if you like the back end to the HTTP server There are a number of ways that your application can commu nicate with the HTTP server These are not all
234. most of the work is done by the slave making minimal changes necessary to the code on the master 11 5 2 4 Custom I O Methods To define a custom I O method you must add a structure of type ConsoleTIo to console_io This structure holds the common handler functions for the I O method The tick function may have a NULL pointer but the rest of the function pointers must be valid pointers to functions 11 5 3 Multiple I O Streams Each I O method has its own state machine in Zconsole That means that each I O method is inde pendent of the others and they can all be used simultaneously This imposes the important restric tion that all command handlers be able to run simultaneously on different I O streams or support proper locking for functions that cannot be performed simultaneously Chapter 11 General Purpose Console 357 11 6 Zconsole Execution Normally Zconsole will communicate over a serial link The physical connection will differ slightly from board to board Basically you will need a 3 wire GND RXD TXD serial cable Several initialization steps must be taken at the beginning of an application program to execute the console 11 6 1 File System Initialization Prior to Dynamic C 7 30 Zconsole depended on the flash file system included with Dynamic C There are actually two file systems FS1 was the first Dynamic C file system The second one FS2 introduced with Dynamic C 7 05 is an improved file system Besides defini
235. mplex and more simple The complexity lies in the added support for multiple interfaces Luckily for us the sim plicity is in the interface to this more intricate implementation In the file tcp config 1lib are predefined configurations that may be accessed by a define of the macro TCPCONFIG For instructions on how to set the configuration please see volume 1 of the manual or LIB TCPIP TCP CONFIG LIB 4 5 1 Serving Static Web Pages The sample program Static c initializes HTTP LIB and then sets up a basic static web page It is assumed you are on the same subnet as the controller The code for Static c is explained in the following pages From Dynamic C compile and run the program You will see the LNK light on the board come on after a couple of seconds Point your internet browser at the controller e g http 10 10 6 100 The ACT light will flash a couple of times and your browser will display the page Program Name Static c tdefine TCPCONFIG 1 define TIMEZONE 8 memmap xmem use dertcep lib Huse http lib ximport samples tcpip http pages static html index html ximport samples tcpip http pages rabbitl gif rabbitl gif SSPEC MIMETABLE START SSPEC MIME html text html SSPEC MIME gif image gif SSPEC MIMETABLE END SSPEC RESOURCETABLE START SSPEC_ RESOURCE XMEMFILE index html index html SSPEC RESOURCE XMEMFILE rabbitl gif wWelloloalic il Gali SSPEC RESOURCETABLE END main sock
236. ms are in use Historical note the name of HTTP_NO_FLASHSPEC implies HTTP however it actually applies to Zserver as a whole not any specific server Dy namic C 8 50 introduces SSPEC_NO_STATIC an alias for HTTP NO_FLASHSPEC SAUTH MAXNAME Maximum length of the name and password strings in the ServerAuth structure De fault is 20 Strings must include a NULL character so with its default value of 20 strings in this structure may be at most 19 characters long Chapter 3 Server Utility Library 39 SAUTH MAXUSERS Define the maximum number of unique users Defaults to 4 This determines the size of the userid table Each table entry takes up 2 SAUTH_MAXNAME 8 bytes of root storage SERVER PASSWORD ONLY This is set to a bitmask of the server mask bits for each server that supports the concept of a password only user that is no user name Defaults to zero since currently no serv ers are implemented that use this facility SSPEC DEFAULT READGROUPS SSPEC DEFAULT WRITEGROUPS SSPEC DEFAULT SERVERMASK SSPEC DEFAULT REALM SSPEC DEFAULT METHOD This group of macros establishes global default permissions for resources that do not have arule associated SSPEC_DEFAULT_READGROUPS is OxFFFF which means all users For writegroups this is 0 meaning no users The servermask defaults to SERVER_ ANY all servers can access realm defaults to that is an empty string or no realm SSPEC_DEFAULT_METHOD default
237. n SSPEC RESOURCE XMEMFILE name addr SSPEC RESOURCE ZMEMFILE name addr SSPEC RESOURCE FSFILE name fnum SSPEC RESOURCE ROOTVAR name addr type format SSPEC RESOURCE XMEMVAR name addr type format SSPEC RESOURCE FUNCTION name addr SSPEC RESOURCE CGI name addr SSPEC RESOURCE P ROOTFILE name addr len realm rg wg sm meth SSPEC RESOURCE P XMEMFILE name addr realm rg wg sm meth SSPEC RESOURCE P ZMEMFILE name addr realm rg wg sm meth SSPEC RESOURCE P FSFILE name fnum realm rg wg sm meth SSPEC RESOURCE P ROOTVAR name addr type format realm rg wg sm meth SSPEC RESOURCE P XMEMVAR name addr type format realm rg wg sm meth SSPEC RESOURCE P_ FUNCTION name addr realm rg wg sm meth SSPEC RESOURCE P CGI name addr realm rg wg sm meth SSPEC RESOURCETABLE END These macros are used to initialize the static resource table Prior to Dynamic C 8 50 this had to be done by explicitly using C language initialization of a table declared as const HttpSpec http spec These macros perform the same function It is recommended to use them instead of stat ic initializers in order to maintain forward compatibility The macros with P_ inthe name are the same as the others except that they explicitly allow all the server permissions information except for the MIME type mapping to be initialized See sspec_addrule for more information on the parameters The name par
238. n are always returned by Zconsole whether the command completed successfully or not 11 3 1 Zconsole Command Data Structure The command system is set up at compile time with an array of ConsoleCommand structures There is one array entry for each command recognized by Zconsole typedef struct char command int cmdfunc long helptext ConsoleCommand command This field is a string like the following SET MAIL FROM That is each word of the command is separated by a space The case of the command does not matter Entering this string is how the command is invoked emdfunc This field is a function pointer to the function that implements the command The func tions that come with Zconsole are listed in Section 11 4 1 1 on page 347 helptext This field points to a text file The text file contains help information for the associated command When HELP COMMAND is entered this text file the help information for COMMAND will be printed to Zconsole The help text comes from ximported text files 344 TCP IP User s Manual 11 3 1 1 Help Text for General Cases There are two cases in Zconsole 1ib where help text is needed but is not associated with a particular command It is still necessary to allocate a ConsoleCommand structure to access the help text The first case is the help overview given when HELP is entered by itself The command field should be and the cmdfunc field should be NULL NULL help t
239. n entry that says that if the resource name ends with html then the MIME type is text html as before and there is a special scripting function that must be run by the HTTP server This script ing function is called zhtml_handler it is provided by the HTTP library ZHTML is the unique embedded scripting language that converts script files into ordinary HTML so the browser can understand it 1 Most applications will want to use a different resource suffix to distinguish between ordinary HTML files and script files The samples provided with dynamic C use zhtml for script files and html for plain HTML In this sample we only have script files so it is convenient to retain the html suffix The other reason for this relates to the way the HTTP server handles requests for a directory If given a URL of the HTTP server will append index html to determine the actual resource We take advantage of this default behavior so that this sample would work as expected 14 TCP IP User s Manual The int io state and web statements define and register a web variable Such a variable is an ordinary global variable as far as your C program is concerned In addition the script is able to access it my io polling isa function that is part of the Application Specifics sub block As the name suggests it is called regularly to poll some external device so as to keep the web variable up to date The implementation of th
240. name is not resolved to an IP address until you start calling smtp _mailtick RETURN VALUE SMTP_OK Server name was set successfully SMTP_NAMETOOLONG The server name was too long SEE ALSO smtp sendmail smtp_setserver_ip smtp _mailtick smtp setserver ip int smtp setserver ip longword server DESCRIPTION Sets the SMTP server This value overrides the value set by smtp_setserver and is used when the IP address of the mail server is known PARAMETER server Server IP address RETURN VALUE SMTP_OK server IP was set successfully SEE ALSO smtp sendmail smtp_setserver smtp _mailtick 322 TCP IP User s Manual smtp status int smtp_status void DESCRIPTION Return the status of the last e mail processed RETURN VALUE SMTP_SUCCESS e mail sent SMTP_ PENDING e mail not sent yet call smtp_mailtick again SMTP_TIME e mail not sent within SMTP_ TIMEOUT seconds SMTP_UNEXPECTED received an invalid response from SMTP server LIBRARY SMTP LIB Chapter 8 SMTP Mail Client 323 324 TCP IP User s Manual 9 POPS Client Post Office Protocol version 3 POP3 is probably the most common way of retrieving e mail from a remote server Most e mail programs such as Eudora MS Outlook and Netscape s e mail client use POP3 The protocol is a fairly simple text based chat across a TCP socket normally using TCP port 110 There are two ways of using POP3 LIB The first method provides
241. ncements the configu ration macro FTP_USE_FS2 HANDLERS must be defined to enable FS2 support in the default file handler functions The structure that holds the association of filenames and FS2 file locations is the server spec list the global array defined in zserver 1ib It is stored in the User block and the API functions ftp_save_ filenames and ftp _load_filenames are used for support of this NOTE For a demonstration of the enhanced FTP server see the sample program SAMPLES TCPIP FTP FTP_SERVER_FULL C Chapter 6 FTP Server 277 6 1 Configuration Macros The configuration macros control various conditions of the server s operation Read through them to understand the default conditions Any changes to these macros may be made in the server application with define statements before inclusion of FTPSERVER LIB FTP CMDPORT This macro defaults to 21 which is the well known FTP server port number You can override this to cause the server to listen on a non standard port number FTP CREATE MASK This macro specifies the mask that is passed into the servermask parameter in sspec_addfsfile calls when a new file is created In particular this defines which servers will be allowed to access this file By default it is defined to SERVER_FTP SERVER _WRITABLE FTP DTPTIMEOUT The default is 16 the same as FTP_ TIMEOUT This applies to the data transfer port instead of the command port The data transfer port is involved wi
242. ng or context was NULL or the resource was not a file type or O CREAT O_TRUNC or O_ APPEND were specified without O WRITE ENOMEM Insufficient storage for handle or buffers Increase definition of SSPEC MAX OPEN EPERM Operation not permitted for example opening an xmem file for writing SEE ALSO sspec_read sspec_ write sspec_seek sspec_tell sspec_close 118 TCP IP User s Manual sspec pwd char sspec pwd ServerContext context char buf DESCRIPTION Print the current working directory in the ServerContext structure to the specified buffer The context gt cwd field contains the CWD This function removes the root directory component context gt rootdir and copies the result This makes rootdir invisible to the end user The leading slash is included but the trailing slash is omitted from the result unless the result is just For example if context gt rootdir points to A and context gt cwd contains A ftpfiles ftpfiles will be the result returned in buf PARAMETERS context Server context structure Two fields in this are of interest rootdir points to a virtual root directory for this server and cwd is a character array containing the CWD buf Points to buffer that is filled with resulting string This buffer is as sumed to be dimensioned at least SSPEC_MAXNAME chars long and it will be null terminated on return RETURN VALUE The buf parameter
243. ng the macro that directs the file system to EEPROM memory and including the appropriate library i e define FS FLASH use filesystem 1lib If using the improved file system available with Dynamic C 7 05 substitute fs2 lib for filesystem lib the application program must initialize the file system with a call to fs init Starting with Dynamic C 7 30 none of this is necessary because Zconsole saves configuration information to the User block See the Rabbit 2000 Microprocessor User s Manual or the Rabbit 3000 Microproces sor User s Manual for more information about the User block 11 6 2 Serial Buffers If the pre defined serial I O methods are used the circular buffers used for I O data can be resized from their default values of 31 bytes by using macros For example if CONSOLE _IO SERIALC is included in console _io then lines similar to the following can be in the application pro gram define CINBUFSIZE 1023 define COUTBUFSIZE 255 In general these buffers can be smaller for slower baud rates but must be larger for faster baud rates 11 6 3 Using TCP IP To use the TCP IP functionality of Zconsole you must have the following line in your application program use dcrtcp lib If you are serving web pages you must also include http lib and if you are sending e mail you must include smtp 1ib 358 TCP IP User s Manual 11 6 4 Required Zconsole Functions To run the console the following
244. nimal buffering Starting with Dynamic C 7 20 you can specify passive mode transfers This is most important for clients which are inside a firewall Passive mode is specified by passing the FTP MODE PASSIVE option to ftp client setup When passive mode is specified the client will actively open the data transfer port to the server rather than the other way around This avoids the need for the server to penetrate the firewall with an active connection from the out side which is most often blocked by the firewall For this reason it is recommended that your FTP client application uses passive mode by default unless overridden by an end user 5 1 Configuration Macros The following macros may be defined in a define statement before the inclusion of FTP CLIENT LIB in an application program Note that strings must contain the NULL byte so if a maximum string length is 16 the maximum number of characters is 15 FTP MAX DIRLEN The default is 64 which is the maximum string length of a directory name FTP MAX FNLEN The default is 16 which is the maximum string length of a file name FIP MAX NAMELEN The default is 16 which is the maximum string length of usernames and passwords FTP MAXLINE The default is 256 which is both the maximum command line length and data chunk size that can be passed between the FTP data transfer socket and the data handler if any defined FIP TIMEOUT The default is 16 which is the numb
245. nly 0 0 eee 143 http_getURL eee eee 232 sspec_SetpermMissiONs eee 144 http_getUserState oo eee 233 sspec_setpreformfunction 145 http_handler 0 eee eeeee eee 234 sspec_setrealM 0 eee eee 146 Hitt pte oiriin 235 sspec_Setsavedata ceeeeeeeeseeeee 147 At PAN eed csee n erei eies 236 SSPCC_SELUSET nien n 148 http_nextfverr seser 237 SSPEC stat i enan ni nase 149 http_parseform 0 0 eee eee 238 sspec tellin eien eii 151 httpxsale vice siete ieee lek 239 SSPOC WEE sioro pe atete etter 152 http SCanposts s c s ccsece seesseeessteseweoss 240 http_set_anonyMOub cece 241 Ae HTTP Setv r innia iis 153 EE A E E 342 4 1 HTTP Server Data Structures 154 http setCond ensisi e 243 HttpState 154 http_SetcOOKie 0 0 eeeeeeeeeeeeeeeeeeee 244 4 2 Configuration Macros ssssssssessee 157 TE an Se Sending Customized HTTP Headers to http_shutdown ccccccccssecsecseeseeeseeee 247 the Client 159 http_skipCGl eee eeeee 248 Saving Custom Headers from the Client http_sock_bytesready 249 160 http_sock_fastread 0 0 ee eeeeeeeeeee 250 ae http_sock_fastwrite 0 251 4 3 Authentication Methods 00000 161 http Sock set8 sce ivesieacaieseessavscnveuscs 252 4 4 Setting the Time Zone c ccccccee 162 ae erener ri keene is a tP_SOCK_UDleIt eee ee eee 4 5 Sample Programs eeseeeeeeseeceeeees 163 Kfar ock_write SE aan 255 Ser
246. no need to call this function unless it is desired to assign a name to an FS2 file other than the default which is filel file2 etc For more information regarding the FS2 filesystem please see the Dynamic C User s Manual PARAMETERS name Name of the new file filenum Number of the file in the file system 1 255 This is the number passed in as the second parameter to fcreate or the return value from fcreate_ unused servermask Bitmask representing servers for which this entry will be valid e g SERVER HTTP SERVER_FTP RETURN VALUE 1 Failure 20 Success location of file in TCP IP servers object list LIBRARY ZSERVER LIB SEE ALSO sspec_addrootfile sspec_addfunction sspec_addvariable sspec_addxmemfile sspec_addform sspec_aliasspec Chapter 3 Server Utility Library 61 sspec addfunction int sspec addfunction char name void fptr word servermask DESCRIPTION Adds a function to the RAM resource list Make sure that SSPEC_MAXSPEC is large enough to hold this new entry This function is currently only useful for HTTP servers NOTE If using HTTP upload facility and or the new CGI interface use sspec_addCGI instead PARAMETERS name Name of the function tpr Pointer to the function servermask Bitmask representing servers for which this function will be valid currently only useful with SERVER _HTTP RETURN VALUE 1 Failure 20 Success location of the function in the
247. ns are scanned If none are found or none are FAT12 or FAT 16 partitions then an error is returned For FS2 all logical extents will be initialized via the fs_ init function PARAMETERS which The filesystem s to mount This is a bitwise OR of the following constants SSPEC MOUNT _ FS FS or FS2 flash filesystem SSPEC MOUNT_ FAT FAT filesystem 1st drive You can also pass SSPEC_MOUNT_ANY to mount all known file systems 72 TCP IP User s Manual fatstuff Either NULL no info return or must point to a struct of type sspec_fatinfo This structure defined in zserver 1lib consists of the following fields typedef struct dos ctrl ctrl mbr drive drive fat part part 4 sspec_fatinfo When calling this function you should NULL out all these point ers using memset 0 You can then optionally set some of the pointers to valid non NULL values in order to override the defaults supplied by this function If you set the ctrl pointer then it is assumed by this function that you have already called the controller initialization function If the pointer is NULL on entry then this function will call the default controller initial ization via the DOS_CONTROLLER_INIT macro On return pointers that were NULL on entry may be changed to point to valid default information In particular the ctrl and drive fields will point to defaults One and only one of the NULL part pointers may be set to a defaul
248. nt file user Set up the first file and user file sspec_addxmemfile rabbitA gif rabbitl gif SERVER FTP user sauth_adduser anonymous SERVER FTP ftp set anonymous user sspec_setuser file user sspec_ setuser sspec addxmemfile test1 rabbitl1 gif SERVER FTP user sspec setuser sspec addxmemfile test2 rabbitl1 gif SERVER FTP user Set up the second file and user file sspec_addxmemfile rabbitF gif rabbitl1 gif SERVER FTP user sauth adduser foo bar SERVER FTP sspec setuser file user sspec setuser sspec addxmemfile test3 rabbitl1 gif SERVER FTP user sspec_ setuser sspec addxmemfile test4 rabbitl1 gif SERVER FTP user SOCK iiie Oy Eeo maie TO y use default handlers tcp reserveport FTP_CMDPORT Port 21 while 1 ftp tick 298 TCP IP User s Manual Each user may execute the dir or Is command to see a listing of the available files The listing shows only the files that the logged in user can access Notice the definition for TCP_CONFIG When the value for this macro exceeds 100 a special configuration file is pulled in that will not be overridden by future updates of Dynamic C In the file CUSTOM CONFIG LIB you may specify any network configuration that suits your pur poses Please see LIB TCPIP TCP_ CONFIG LIB for examples of setting up a library of con figuration options 6 5 Getting Through a
249. ntime initializa tion block This is contained in the main function sock_init comes first to initialize the TCP IP network library and bring up the necessary interface s http init resets the HTTP library to a known state The last statement embodies the Main Loop sub block This is always required Typically only http handler needs to be called however your application can insert calls to its own poll ing and event handling code Since this is such a simple example there is not even any applica tion specific code 12 TCP IP User s Manual 2 5 A Simple but Realistic Application To turn the above toy example into something more realistic we need to add some application specifics and the ability to customize the resource returned to the browser depending on the rele vant state of the application The following diagram shows the necessary parts Application Compile Time Run Time Main Application CGI Initialization Initialization Loop Specifics Q_ _ Functions web Variables Metadata Requests MIME Resources Context Table N Zserver TCP IP Resource Manager Table File Systems Static Dynamic f Resource Resource FS2 FAT i Table Table i AEE DEE AO REN ETE AE Storage Figure 2 3 Minimum components for a web enabled application with dynamic content The easiest way to introduce dynamic content is to use the RabbitWeb module and the associated scripting language R
250. ntioned above http defaultCGI 216 TCP IP User s Manual http getCond int http getCond HttpState state int idx DESCRIPTION Return the current HTTP condition state variable aka cond variable There are HTTP MAX _ COND of these integer state variables thus idx must be between 0 and HTTP MAX COND 1 inclusive Use of cond variables is entirely up to the application however they are initialized by the HTTP server under certain conditions By default they are set to zero at the start of each request from the client If the client request includes URL GET type parameters of the form http host resource html A 1 amp B 2 amp C 3 etc then cond state 0 is set to the value for A cond state 1 is set to the value for B etc The values must be integers which are coerced into 16 bit signed integers NOTE This is implemented as a macro PARAMETERS state HTTP state pointer as provided in the first parameter to the CGI function idx Index of cond variable 0 HTTP_MAX COND 1 Validity is not checked RETURN VALUE Value of cond variable idx LIBRARY HTTP LIB SEE ALSO http _getAction http _setCond Chapter 4 HTTP Server 217 http getContentDisposition char http getContentDisposition HttpState state DESCRIPTION Return the current disposition of the data which is being provided by the client This is one of the following enumerated values MIME DISP_ NONE unspecified disposition MIME DIS
251. nto the internal header buffer for the given header It returns 1 on error and the number of bytes in the header on success Note that some headers are saved by the HTTP server by default into the HTTP state structure such as Content Length We will also begin saving the Host header which is useful in per forming CGI redirection Hence we can change the semantics of the cgi_redirectto function int cgi _redirectto HttpState state char url such that the url parameter no longer needs to be an absolute URL 4 3 Authentication Methods HTTP 1 0 Basic Authentication is used by default This scheme is not a secure method of user authentication across an insecure network e g the Internet HTTP 1 0 does not however pre vent additional authentication schemes and encryption mechanisms from being employed to increase security Starting with Dynamic C version 8 01 HTTP Digest Authentication as specified in RFC 2617 is supported Instead of sending the password in cleartext as is done using Basic Authentication MDS is used to perform a cryptographic hash To use HTTP Digest Authentication define USE _HTTP_ DIGEST AUTHENTICATION as 1 When this USE_ macro is defined the mac ros HTTP_MAX NONCES and HTTP DIGEST NONCE_ TIMEOUT are available they affect negotiation time between server and client For more details see Section 4 2 Configuration Mac ros In either case basic and or digest you will need to add the app
252. null term string in the main buffer CGI_SEND_DONE combination of the above two 194 TCP IP User s Manual Action Code CGI_CONTINUE In the case we are discussing the CGI_ MORE return code is used This tells the server that the CGI function is busy trying to do something but it could not complete the task It wants to be called back again but without any new incoming data Thus if the CGI function returns CGI_MORE the HTTP server will eventually come back with a special action code which has not been mentioned yet called CGI_ CONTINUE The CGI needs to respond to this code so that it can continue doing what it was trying before This implies that the CGI will need to remember at least a bit of information like how many bytes of the total it suc cessfully wrote For this it can use the state and cond variables The following code shows the relevant sections for following this protocol int len newlen define COND LEN 1 case CGI DATA handle http getCond s COND HANDLE len sspec_write handle http getData s http getDataLength s j if len lt 0 permanent error sspec_close handle http_switchCGI s upld_err html else if len lt http getDataLength s no error but not all written http _setCond s COND LEN len save place in file return CGI MORE tell server we re not done break case CGI CONTINUE CGI_MORE returned last time handle http ge
253. o not finished yet then it is called again if the connection is aborted except if egi_redirectto has been called from the epilog function In that case the epilog function is not called after an abort username Read only buffer has username of the user making the request if authentication took place Note New code should use the http_getContext macro then use the results to look up the user details using the sauth_ functions See the documentation for the ServerContext Structure in the previous chapter password Read only buffer has password of the user making the request if authentication took place See the above note cookie Read only buffer contains the value of the cookie DCRABBIT see http_setcookie for more information 156 TCP IP User s Manual headerlen headeroff These variables can be used together to cause the web server to flush data from the buffer array in the HttpState struc ture headerlen should be set to the amount of data in buffer and headeroff should be set to 0 to indicate the offset into the array The next time the CGI function is called the data in buffer will be flushed to the socket For new code consider writing a new style CGI function which obviates the need to manipulate these fields cond Support for conditional SSI error feedback etc New code should use the macros http_getCond and http _setCond userdata This field is included if HITT
254. o the filesystem When considering security there are three possible things to protect e The web page that contains the form Give read access only to those users who could con ceivably upload the files specified therein e The CGI itself Protect the same as the web page e The uploaded resource You should set up a rule allowing write access only to the intended user s When defining user IDs that can use the upload don t forget to give those users overall write access using e g sauth_setwriteaccess uid SERVER HTTP Another way to design this application is to have a separate HTML file that contains the form for the file upload then instead of having the form for the file upload on the current HTML page you put a link to the new page and then apply a permission to allow the new page to be displayed such as sspec addrule newpage html Pet admin _group admin_group SERVER_HTTP SERVER AUTH BASIC NULL Chapter 2 Web Enabling Your Application 25 That way the only people who see the Upload button are those authorized to use it Design deci sions such as these are guided by the needs of the application The point here is that these design decisions are not limited by the underlying tools you are using to accomplish your goal 2 8 Living Without RabbitWeb and FAT Without the use of RabbitWeb we are back to SSI tags in the HTML page and writing a CGI to process them With the new style CGIs introduced in Dyn
255. oad process If you have an existing web based application to which you want to add a file upload facility you probably already have a web page with a form on it in this case you can add an extra input field to an existing form on that page or create a new form on the same page You may already have a CGI function that processes the results of the form submission This will need to be rewritten to process data that is not URL encoded If you are creating a new application you need to construct an initial page to contain the necessary form elements As a starting point you can use the sample page in samples tcpip http pages upload html Click on upload html and the browser will display something like this a HTTP Upload Form Microsoft Internet Explorer Oy x File Edit View Favorites Tools Help gt Cut Copy Paste Back Rorverd Stop Refresh Home Search Favorites Address fe E DCinProg Samples tcpip http pages UPLOAD HTML gt I Links gt File to upload _ to A new him Browse File to upload to A new2 hbm Browse Upload g a i 3 My Computer The construction of this page is outlined below but it has been simplified and reformatted slightly A blow by blow description of each line is added in italics 184 TCP IP User s Manual lt html gt This introduces the page as an HTML document lt head gt lt title gt HTTP Upload Form lt title gt lt
256. ocked up forever This can be achieved like this state gt main_timeout set_ timeout HTTP_TIMEOUT HTTP_TIMEOUT is the number of seconds until the web server will time out It is 16 seconds by default A buffer that the developer can use to put data to be transmitted over the socket It is of size HTTP_ MAXBUFFER defaults to 256 bytes Note It is not recommended to directly access buffer or p be low Use the new style CGI functions and the http_write http _getData andhttp getDataLength functions instead These create a much easier to use and safer method of read ing writing data to the client Pointer into the buffer given above See above note This should be treated as read only It holds the method by which the web request was submitted The value is either HTTP METHOD GETorHTTP_ METHOD POST for the GET and POST request methods respectively Use http _getHTTPMethod for new code This should be treated as read only It holds the URL by which the current web request was submitted If there is GET style form in formation then that information will follow the first NULL byte in the url array The form information will itself be NULL terminated If the information in the url array is truncated to HTTP_MAXURL bytes the truncated information is also NULL terminated Use http _getURL for new code This should be treated as read only This holds the version of the HTTP request that was made It
257. ode illustrates int uid uid sauth_adduser admin upload SERVER HTTP sauth_setusermask uid ADMIN GROUP NULL sauth_ setwriteaccess uid SERVER HTTP This sets up a single user with userid admin and password upload The user is only known to the HTTP server sauth_setusermask is required when a userid is created since the default may not be satisfactory It makes sure the user is placed into the correct group s in this case the ADMIN GROUP that we defined above Finally each user must be individually granted write access using the sauth_setwriteaccess function If this is not done the user will not be able to write the file in spite of passing other tests Step 11 Tying It All Together After performing the above steps the actual running of the HTTP server and CGI is almost trivial The main C function should have a loop in it which calls http_handler void main int uid sock init Initialize the network Mount the FAT filesystem sspec automount SSPEC MOUNT ANY NULL NULL NULL Create the authorized user as described in the previous section uid sauth_adduser admin upload SERVER _HTTP sauth_setusermask uid ADMIN GROUP NULL sauth_ setwriteaccess uid SERVER HTTP http init Initialize the HTTP server tcp reserveport 80 Enable smooth handling of multiple HTTP requests for http _handler The big loop Drives everything
258. oding type for the form s information If you did not specify this option then you can use old style CGIs as described in this section If you specify enctype multipart form data then you should specify a new style CGI instead See Section 4 6 describing the HTTP upload feature for more details on writing a new style CGI The INPUT tag defines a specific form element the individual input fields in a form For example a text box in which the user may type in a value or a pull down menu from which the user may choose an item The TYPE parameter defines what type of input field is being used In the follow ing example in the first two cases it is the text input field which is a single line text entry box The NAME parameter defines what the name of that particular input variable is so that when the information is returned to the server then the server can associate it with a particular variable The VALUE parameter defines the current value of the parameter The SIZE parameter defines how long the text entry box is in characters At the end of the HTML page in our example the Submit and Reset buttons are defined with the INPUT tag These use the special types submit and reset since these buttons have special pur poses When the submit button is pressed the form is submitted by calling the CGI program myform 170 TCP IP User s Manual 4 5 3 1 Sample HTML Page An HTML page that includes a form may look like th
259. of modifiable variables SSPEC_ CGI The data is a CGI function for HTTP new style CGIs with better interface SSPEC_ LINK Symbolic link alias to another resource name SSPEC HARDLINK Symbolic link alias to another resource table entry 3 2 2 ServerSpec Vartype Field If the object is a variable then this field will tell you what type of variable it is INTS8 INT16 INT32 PTR16 FLOAT32 3 2 3 ServerPermissions Servermask Field The type of server HTTP and or FTP that has access to a particular resource is determined by the servermask field in the ServerPermissions structure SERVER_HTTP Web server SERVER_FTP File transfer server SERVER_SMTP Mail server SERVER_HTTPS Secure web server SERVER_SNMP SNMP agent SERVER_USER Placeholder for first user defined server SERVER_USER2 Placeholder for second user defined server etc grow down SERVER ANY Any server May be passed in most cases when any server will do 3 2 4 Configuration Macros There are several configuration macros that may be set up by the application to control the mem ory usage and behavior of Zserver These should be defined before use Zserver 1lib unless otherwise noted HTTP NO FLASHSPEC SSPEC NO STATIC When defined these macros saves space by not compiling in code that supports a static resource table Presumably the application is using only the dynamic resource table or filesyste
260. offset may be nega tive zero or positive SEEK END end of file offset should be non positive to stay within the file RETURN VALUE 0 OK The following return values are negatives of the values defined in errno 1lib EINVAL whence parameter was invalid EBADF The specified handle was not open or invalid EPERM Operation not permitted on this file resource This is usually because the resource is not seekable such as a compressed file Any other negative values indicate an error SEE ALSO sspec_close sspec_write sspec_read sspec_tell sspec_open 130 TCP IP User s Manual sspec setformepilog int sspec setformepilog int form int function DESCRIPTION Sets the user specified function that will be called when the form has been successfully submitted This function can for example execute a cgi_redirectto to redirect to a specific page It should accept HttpState stateas an argument return 0 when it is not finished and 1 when it is finished 1 e behave like a normal CGI func tion PARAMETERS form spec index of the form function spec index of the function to call when the specified form has been successfully submitted This is the return value of the function sspec_addfunction RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_setformprolog Chapter 3 Server Utility Library 131 sspec setformfunction int sspec setformfunction int fo
261. ointer as provided in the first parameter to the CGI function RETURN VALUE Length of available data This will range from 0 to HTTP_ MAXBUFFER 0 will only be returned for PROLOG and EPILOG when a blank line is read LIBRARY HTTP LIB SEE ALSO http getAction 224 TCP IP User s Manual http getField char http getField HttpState state DESCRIPTION Return the current form field name This function should only be called when the action code is CGI_ START CGI_DATAor CGI_ END NOTE This is implemented as a macro PARAMETER state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE Null terminated string containing the current field name The field name is the name of a form element specified using for example lt INPUT TYPE TEXT NAME srv_file gt in the HTML where srv_ file is the field name If there was no name parameter in the returned form data this will be an empty string zero length not NULL LIBRARY HTTP LIB SEE ALSO http _getAction Chapter 4 HTTP Server 225 http getHTTPMethod char http getHTTPMethod HttpState state DESCRIPTION Return the HTTP request method of the current request protocol The CGI might need to look at this to generate the correct response headers NOTE This is implemented as a macro PARAMETER state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE One of
262. omplete initialization of the TFTP state structure where the structure is possibly stored somewhere other than in the root data space This is a wrapper function for tftp _init See that function description for details PARAMETERS ts addr Physical address of TFTP state struct t tp_state RETURN VALUE 0 OK 1 Error default socket in use LIBRARY TFTP LIB 306 TCP IP User s Manual tftp tick int tftp tick struct tftp state ts DESCRIPTION This function is called periodically in order to take the next step in a TFTP process Ap propriate use of this function allows single or multiple transfers to occur without block ing For multiple concurrent transfers there must be a unique tftp_ state structure and a unique UDP socket for each transfer in progress This function calls sock tick PARAMETERS ts Pointer to TFTP state This must have been set up using tftp _init and must be passed to each call of tftp _tick without alteration RETURN VALUE 1 OK transfer not yet complete 0 OK transfer complete 1 Error from remote side transfer terminated In this case the ts_addr gt file field will be overwritten with a NULL terminated error message from the server 2 Error could not contact remote host or lost contact 3 Timed out transfer terminated 4 not used 5 Transfer complete but truncated buffer too small to receive the complete file LIBRARY TFTP LIB Chapter 7 TFTP
263. on set user timeout void con _set_user timeout void funcptr DESCRIPTION Sets a user defined function that will be called when a timeout event has occurred The user defined function should take an argument of type ConsoleState LIBRARY zconsole lib SEE ALSO con_set_user_idle console disable void console disable int which DESCRIPTION Disable processing for the designated console in the console _io array This func tion along with console enable allows the sharing of the Zconsole port with some other processing PARAMETER which The console to disable LIBRARY zconsole lib SEE ALSO console init console enable Chapter 11 General Purpose Console 365 console enable void console enable int which DESCRIPTION Enable processing for the designated console in the console _io array This func tion along with console disable allows the sharing of the Zconsole port with some other processing PARAMETER which The console to enable LIBRARY zconsole lib SEE ALSO console init console disable 366 TCP IP User s Manual 11 6 6 Zconsole Execution Choices Zconsole can be used interactively with a terminal emulator or by sending commands from a pro gram running on a device connected to the controller that is running the console 11 6 6 1 Terminal Emulator To manually enter Zconsole commands from a keyboard and view results in the Stdio window you must
264. one web browser Netscape Mozilla Internet Explorer Opera with its graphical user interface so they will be ready to start controlling your application with minimal training This chapter provides an overview of the steps you will need to take to web enable an application Knowledge of browsers and something of their capability is assumed With this knowledge you can understand the concepts described in this chapter The following chapters go into more detail about the specific libraries but for simple programs you may be able to use just the information in this chapter along with the sample code to write a working application Dynamic C provides libraries that implement most of the functions required to implement a web server more formally known as an HTTP HyperText Transfer Protocol server The browser is formally called an HTTP client You only need to write code specific to your application such as dealing with I Os and the Rabbit peripheral devices and possibly some code to help the HTTP server generate the appropriate responses back to the user s web browser In addition there is a small amount of boilerplate that needs to be written to include and configure the HTTP server and any ancillary libraries such as the TCP IP suite and filesystems 2 1 Designing Your Application Should you decide to web enable your application you probably already have some idea of the format and layout of the web pages that will be present
265. only form var 1 These lines set up the low temperature variable It is set up in much the same way as the high tem perature variable Var sspec addvariable templo amp templo INT16 sd SERVER HTTP IS var sspec_addfv form var sspec_setfvname form var Low Temp sspec_setfvdesc form var Minimum in temperature range 50 80 amp deg F sspec_setfvlen form var 5 SES peri vrenge Torn ver SO 80 This code begins setting up the string variable that specifies what to do in case of air conditioning failure Note that the variable is of type PTR16 and that the address of the variable is not given to sspec_addvariable since the variable fail already represents an address Var sspec addvariable failure fail PTR16 ss SERVER_HTTP var sspec addfv form var sspec setfvname form var Failure Action sspec_setfvdesc form var Action to take in case of air conditioning failure SSOSe_SSiciwileia torm wee 20 z Chapter 4 HTTP Server 179 This line associates an option list with a form variable The third parameter gives the developer defined option array and the fourth parameter gives the length of the array The form variable can now only take on values listed in the option list sspec setfvoptlist form var fail options 4 This function sets the type of form element that is used to represent the variable The default
266. or more than FTP_MAXLINE bytes PARAMETERS fd The file descriptor returned when the file was opened buf Pointer to the buffer to place the file contents offset Offset in the file at which copying should begin len The number of bytes to read RETURN VALUE 0 EOF gt 0 The number of bytes read into buf 1 Error transfer aborted Chapter 6 FTP Server 283 ftp dflt write int ftp dflt write int fd char buf long offset int len DESCRIPTION The default write handler does nothing but return zero The specification states that the handler may write the file identified by d buf con tains data of length len which is to be written to the file at the given offset within the file The return value must be equal to len or a negative number if an error occurs such as out of space The FTP server does not handle partial writes the given data must be completely writ ten or not at all If the return code is less than 1 en an error is assumed to have occurred Note that it is up to the handler to ensure that another FTP server is not accessing a file which is opened for write The open call for the other server should return FTP _ERR_UNAVALIL if the current server is writing to a file PARAMETERS fd The file descriptor returned when the file was opened buf Pointer to the data to be written offset Offset in the file at which to start len The number of bytes to write RETURN VALUE 20 The number of bytes written
267. or occurs define define define define define define define define define define define define define define define define define define define define define define define define define CON_ERR_TIMEOUT CON_ERR_BADCOMMAND CON ERR _BADPARAMETER CON_ERR_NAMETOOLONG CON_ERR_DUPLICATE CON_ERR_BADFILESIZE CON_ERR_SAVINGFILE CON_ERR_READINGFILE CON_ERR_FILENOTFOUND CON_ERR_MSGTOOLONG CON_ERR_SMTPERROR CON_ERR_BADPASSPHRASE CON_ERR_CANCELRESET CON_ERR_BADVARTYPE CON_ERR_BADVARVALUE CON_ERR_NOVARSPACE CON_ERR_VARNOTFOUND CON_ERR_STRINGTOOLONG CON_ERR_NOTAFILE CON_ERR_NOTAVAR CON_ERR_COMMANDTOOLONG CON_ERR_BADIPADDRESS CON_ERR_INVALIDPASSWORD CON_ERR_BADIFACE CON_ERR_BADNETWORKPARAM AN AHO FP WN HP NNNNNNKRPRPHPHPHP PPE PB OARWNHPOWUDAYUHDUOAKRWNHEO LO 354 TCP IP User s Manual define CON STANDARD ERRORS CON _ERR_TIMEOUT Timed out CON_ERR_BADCOMMAND Unknown command CON_ERR_BADPARAMETER Bad or missing parameter PN CON_ERR_NAMETOOLONG Filename too long CON_ERR_DUPLICATE Duplicate object found CON_ERR_BADFILESIZE Bad file size CON _ERR_SAVINGFILE Error saving file CON _ERR_READINGFILE Error reading file CON_ERR_FILENOTFOUND File not found CON_ERR_MSGTOOLONG Mail message too long CON_ERR_SMTPERROR SMTP server error CON_ERR_BADPASSPHRASE Passphrases do not
268. ort 23 must match server define REM HOST 10 10 6 19 Remote IP to connect to main SOCK aiasie Initialize the stack Tell the server to connect and reconnect if the connection is lost telnet init TELNET RECONNECT resolve REM_HOST 7 SERVER_PORT a while telnet_tick Run client this is non blocking continue telnet close Error close telnet connection 342 TCP IP User s Manual 11 General Purpose Console The library zconsole 1lib implements a serial based console that we call Zconsole It can be used to e Configure a board e Upload and download web pages e Change web page variables without re uploading the page e Send e mail e Calls subsystem initialization for ARP TCP UDP and DNS if applicable 11 1 Zconsole Features Recognizing that embedded control systems are wide ranging in their requirements zcon sole 1lib was designed with flexibility and extensibility in mind Designers can choose the available functionality they want and leave the rest alone Zconsole includes e Login name and password protection e Default and custom Zconsole commands Default and custom error messages e Help text for Zconsole commands including custom commands e Multiple I O streams that can be used simultaneously e A fail safe backup system for configuration data 11 1 1 File System Requirement Prior to Dynamic C 7 30 an application program using Zconsole must include the line
269. ount of extended memory to allocate xalloc for each HTTP server instance If you do not define it then socket buffers are allocated from the usual pool See tcp _extopen for more details Chapter 4 HTTP Server 157 HTTP DIGEST NONCE TIMEOUT This macro is used when USE_HTTP DIGEST AUTHENTICATION is set to one Nonces that are generated by the server are valid for this many seconds 900 by de fault If set to 0 nonces are good forever Setting this to a smaller value can possibly result in higher security although internal use of the nonce count facility offsets this Setting it to a larger value reduces the negotiation between the browser and the server since when a nonce times out the browser must be told that it is using a stale nonce value and provided with a new one Since Mozilla and Netscape ignore the stale param eter the user must reenter the username and password when a nonce times out Internet Explorer and Opera respect the stale parameter so they automatically try the username and password with the new nonce without asking the user HTTP MAXBUFFER This is the size of the buffer accessible through the Ht tpSpec structure It defaults to 256 bytes The size of this buffer affects the speed of the HTTP server the larger the buffer up to a point the faster the server will run The buffer size is also important for use in CGI functions because it is a work space the programmer can use HTTP MAXBUFFER must be at le
270. ow There is quite a lot to HTML forms so most of the details are documented elsewhere There are many good HTML reference books available lt HTML gt lt HEAD gt lt TITLE gt Web Variables lt TITLE gt lt HEAD gt lt BODY gt lt H1 gt Web Variables lt H1 gt lt P gt The current value of io state is lt z echo S io state gt lt P gt lt z if error io state gt lt P gt Sorry you were not authorized to perform an update lt P gt lt z gt lt FORM ACTION index html METHOD POST gt lt P gt Enter a new value if you dare lt P gt lt INPUT TYPE text NAME io state SIZE 5 VALUE lt z echo S io state gt gt lt INPUT TYPE submit VALUE Submit gt lt INPUT TYPE reset VALUE Reset gt lt FORM gt lt BODY gt lt HTML gt If you run the above sample with this script then the user will be able to attempt an update to the web variable io state If the user was monitor that is not able to make an update then the Sorry message will be printed Recall that the access to io state was set up when the variable was registered with web You may be asking how the application notices when the web variable is updated by the browser not just in the my_io polling function This is a good question since the HTTP server updates the variable just like a normal C variable The solution to this requires that you specify an update callback function in the web variable registration
271. p_mailtick again SMTP_TIME e mail not sent within SMTP_ TIMEOUT seconds SMTP_UNEXPECTED received an invalid response from SMTP server SMTP_DNSERROR cannot resolve server name SMTP ABORTED transaction aborted by data handler If using SMTP AUTH the following values are also possible SMTP_AUTH_ UNAVAILABLE unable to attempt authentication SMTP_AUTH_ FAILED attempts to authenticate failed LIBRARY SMTP LIB SEE ALSO smtp sendmail smtp_status 318 TCP IP User s Manual smtp sendmail void smtp sendmail char to char from char subject char message DESCRIPTION Start an e mail being sent This function is intended to be used for short messages that are entirely constructed prior to being sent If you have previously installed a data handler via smtp _data_handler then you must call smtp_data_handler with a NULL data handler otherwise this message will not get sent NOTE The strings pointed to by the parameters must not be changed until the entire process is completed Also if the first character of any line of the message is a period then this character will be deleted as part of normal mail processing Thus to actu ally send a line starting with you must start the line with i e double up an initial period PARAMETERS to from subject message RETURN VALUE None SEE ALSO smtp _mailtick String containing the e mail address of the destination Maximum
272. page see below that contains a form the user can fill in with the name of the file to upload The other resource CGI is a reference to this function giving ita URL name that identifies it to the browser 2 Create a web page which contains a form like the following skeleton exam ple lt FORM ACTION upload cgi METHOD POST enctype multipart form data gt lt INPUT TYPE FILE NAME A incoming new htm gt lt INPUT TYPE SUBMIT VALUE Upload gt lt FORM gt in the lt FORM gt element the ACTION parameter specifies the URL assigned to this CGI In the lt INPUT TYPE FILE gt element the NAME parameter specifies the resource name used to contain the uploaded file con tents In this example the resource is called A incoming new htm which will work if you are using the FAT filesystem If uploading to a subdirectory incoming in the above example the subdi rectory must already exist If not the upload will fail Chapter 4 HTTP Server 209 3 To add user authentication and other facilities there are three possible things to protect e The web page containing the form Give read access only to those users who could conceivably upload the files specified therein e The CGI itself this function Protect as for a e The uploaded resource You should set up a rule allowing write access only to the intended user s When defining user IDs which can use the upload do not forget to give those users
273. r cmddata CON CMD DATA SIZE ifndef CON_NO FS SUPPORT File processing not needed with DC 7 30 FileNumber filenum Use for file processing File file Use for file processing endif int spec Use for working with Zserver entities long timeout Use for extending the time out ConsoleState endif To accomplish its tasks the function should use state gt substate for its state machine which is initialized to zero before dispatching the command handler and state gt command to read out the command buffer to get other parameters to the command for instance In case of error the function should set state gt error to the appropriate value The buffer at state gt cmddata is available for the command to preserve data across invoca tions of the command s state machine The size of the buffer is adjustable via the CON_CMD_ DATA SIZE macro set to 16 bytes by default Generally this buffer area will be cast into a data structure appropriate for the given command state machine 352 TCP IP User s Manual Both state gt numparams and state gt commandparams are read only The latter was introduced in Dynamic C 7 30 It indicates the number of arguments in the command line that are NOT part of the command name itself For instance for the command SET IP 10 10 6 112 ETHO state gt commandparams would be 2 but state gt numparams would be 4 This distinc tion is made to allow the commands in Zconsole to be insensi
274. r of the opened file FTP ERR _NOTFOUND File not found FTP ERR _NOTAUTH Unauthorized user FTP ERR _BADMODE Requested option 2nd parameter is not supported FTP _ERR_UNAVALIL Resource temporarily unavailable In the first case the returned value is passed to subsequent handler routines to identify the particular file or resource as the fd parameter If necessary you can use this num ber to index an array of any other state information needed to communicate with the other handlers The number returned should be unique with respect to all other open resource instances so that your handler does not get confused if multiple FTP data transfers are active simultaneously Note that the given file name may be an absolute or relative path if the handler supports the concept of directories then it should handle the path name as appropriate and not just assume that the file is in the current directory If the filename is relative then the cwd parameter indicates the current directory Chapter 6 FTP Server 281 ftp dflt getfilesize long ftp dflt getfilesize int fd DESCRIPTION Return the length of the specified file This is called immediately after open for a read file If the file is of a known constant length the correct length should be returned If the resource length is not known perhaps it is generated on the fly then return 1 For write operations the maximum permissible length should be returned or 1 if not kno
275. ree 70 sspec_setfventrytype 0 eects 137 SSPOC_A lASSPEC oi iiei a 71 sspec_setfvfloatrange oes 138 sspec_resizerootfile ee eeeeeeeeseeceeeees 126 SSPeC_SetfVIEN 00 eeeeeeecseceeeceseeeseeceeeees 139 Dynamic Rule Table SSpec_SetfVNAME o eee eee et eeeeeeeeee 140 sspec_addrule oo eee ee eeeeeeseeseeereeneeeaee 65 sspec_SetfVvoptlist 0 eects ceeeeees 141 sspec_removerule 0 eeeeeeeeeeeeceeeeeteceeeees 124 SSPCC_SCtfVFANGE peirar ii 142 E mail sspec_setfyreadonly eseseeeseeerereerreeeee 143 POp3 Petal oo scceccsse cs pessssisss eseeeaioepesees 328 sspec_setpreformfunction ee 145 POP3Z AMIE s 28 7A Sass ean SAS 327 HTTP Server POPBiAICK oss ssssscsveesssteses sssescsvesssteasssetteteaces 329 http findname es ssseecs hese cesses theses is 213 smtp_mailtick oo eee cseeeeceteeeees 318 http_getcontext occ ceteeees 221 smtp_Sendmail ec eeeeesceeeeceseeeneceenees 319 http_handler 0 eee eeeeeesseceeeeceeeeesseeenees 234 380 TCP IP User s Manual http idle cis etsvins cascusnee cb e ch cnceeeoeucnes 235 sspec_needsauthentication 0 0 0 eee 115 Atip ANTE eoria E E EE 236 sspec TEAC S narenn aeeseseoentans 121 http Sale cali aintien ei acct 239 Spec remove isisisi eierens ei 123 http_set_aMONyMOUS 1 0 eee ceeeeeeeeeeeeeeee 241 SSPEC_TEMOVEUSET ee eeeecesseeceseeeeeeeeees 125 http Set path arein a cists 245 SSPECATESLOLE ceio oe teed wei Es cess 127 http_setauthentication 0 0
276. reference only username password mask writeaccess servermask data Name of user or Password or Group mask Which servers this user has write access to Which servers this user is visible to Arbitrary data application dependent 3 1 4 ServerPermissions Structure This data structure holds access permissions for a resource or a group of resources An instance of ServerPermissions is contained in each ServerSpec structure as well as within each rule table entry The fields for the ServerPermissions struct are realm readgroups writegroups servermask method mimetype Pointer to realm string of the resource It is only used by HTTP serv ers but can be used for other purposes Read permission is granted if the current ServerAuth mask value matches in at least one bit position Write permissions is granted if the current ServerAuth mask value matches in at least one bit position and ServerAuth writeaccess is set A 16 bit mask with a bit set for each server that can access this re source NB for backwards compatibility if this is set to zero then all servers are allowed Authentication method s allowed combination of SERVER_AUTH_ bits Note that Zserver lib does not di rectly support anything other than basic authentication that is SERVER_AUTH_ BASIC however the required information is stored here so that servers can access it as needed in a consistent manner MIME type for this resource
277. riptions when the default handler does not cover the entire function specifi cation The default file handlers are in FTPSERVER LIB 280 TCP IP User s Manual ftp dflt open int ftp dflt open char name int options int uid int cwd DESCRIPTION Opens a file If a file is successfully opened the returned value is passed to subsequent handler routines to identify the particular file or resource as the fd parameter If nec essary you can use this number to index an array of any other state information needed to communicate with the other handlers The number returned should be unique with respect to all other open resource instances so that your handler does not get confused if multiple FTP data transfers are active simultaneously Note that the specified file to open may be an absolute or relative path if the handler supports the concept of directories then it should handle the path name appropriately and not just assume that the file is in the current directory If the filename is relative then the cwd parameter indicates the current directory PARAMETERS name The file to open options File access options O RDONLY marks file as read only O WRONLY not currently supported by the default handler O_RDWR not used since it s not supported by the FTP protocol uid The userid of the currently logged in user cwd Current directory not currently supported by the default handler RETURN VALUE 20 File descripto
278. rm void fptr DESCRIPTION Sets the function that will generate the form PARAMETERS form spec index of the form fptr Form generation function NULL for the default function RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB 132 TCP IP User s Manual sspec setformprolog int sspec setformprolog int form int function DESCRIPTION Allows a user specified function to be called just before form variables are updated This is useful for implementing locking on the form variables which can then be un locked in the epilog function so that other code will not update the variables during form processing The user specified function should accept HttpState stateas an argument return 0 when it is not finished and 1 when it is finished i e behave like a normal CGI function PARAMETERS form spec index of the form function spec index of the function This is the return value of sspec_addfunction RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_setformepilog Chapter 3 Server Utility Library 133 sspec setformtitle int sspec setformtitle int form char title DESCRIPTION Sets the title for an automatically generated form PARAMETERS form spec index of the form title Pointer to the title of the HTML page RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO sspec_getformtitle 134 TCP IP User s
279. rmation about the file resource The flags field can be any number of the following SSPEC_ATTR_MDTM have modification date time SSPEC_ATTR_LENGTH have current length SSPEC_ATTR_ WRITE file is writable SSPEC_ATTR_EXEC file is executable SSPEC ATTR_ HIDDEN Hidden attribute bit SSPEC ATTR_ SYSTEM System attribute bit SSPEC_ATTR_ ARCHIVE Archive attribute bit SSPEC_ATTR_DIR directory name SSPEC_ATTR COMPRESSED stored in compressed format SSPEC_ATTR_MAXLENGTH have maximum length SSPEC_ATTR_SEEKABLE resource is randomly accessible SSPEC_ATTR_ EXTENSIBLE File may be expanded at end mdtm Modification date time SEC_TIMER format this field is only val idif SSPEC_ATTR_MDTM is set length The current file size this field is only valid if SSPEC ATTR_ LENGTH is set maxlength The maximum allowable file size this field is only valid if SSPEC_ ATTR_MAXLENGTH is set perm Pointer to ServerPermissions struct This structure is de scribed above 3 1 8 sspec_fatinfo Structure This structure is only relevant if you are using the FAT filesystem It allows the sspec_ automount function to return some FAT related information to your application The fields in this structure are ctrl Pointer to dos_ctr1 controller structure drive Pointer to mbr_ drive structure part 4 4 pointers to fat_part partition structures Only the mounted partitions are returned Note that when used with sspec_automount
280. ropriate rules and or permissions to the appropriate tables See the previous chapter for details on protecting resources The HTTP server applies the strongest applicable authentication mechanism depending on the information it retrieves from the resource manager Typically in addition to defining user IDs and groups you also need to associate an authentication mechanism with the resource using e g the SSPEC_MM_RULE macro or the sspec_setpermissions function Starting with Dynamic C 8 50 Secure Socket Layer SSL as specified in RFC 2818 is supported It is also known by its newer official name TLS Transport Layer Security To use SSL you must create a secure HTTP server known as an HTTPS server To do this you must define some macros and import the SSL certificate define USE HTTP SSL define HTTP_SSL SOCKETS 1 ximport cert mycert dcc SSL CERTIFICATE For complete documentation on the Dynamic C implementation of SSL see the Dynamic C Module document Secure Sockets Layer SSL Protocol Another good source of information are the sample programs that demonstrate using SSL They are located in the Samples tcpip ssl1 folder that will be created when the Dynamic C Module for SSL is installed Chapter 4 HTTP Server 161 4 4 Setting the Time Zone The HTTP specification requires the server to indicate its current clock time in the response to any request The HTTP implementation performs this function by consulting the
281. rtc_ timezone library function in RTCLOCK LIB The server uses the returned time zone to adjust the local real time clock RTC value so that it is always returned to the client in UTC Co ordinated Universal Time There are several macros which you can set to define TIMEZONE The local timezone offset from UTC RTC_IS_UTC Whether the RTC is already running on UTC The local timezone offset may be defined using the TIMEZONE macro or it may be obtained automatically from a DHCP server if you are using DHCP to configure the network interface Failing that it defaults to zero If the RTC is already set to UTC not local time then you must define the macro RTC_IS_UTC in which case the local timezone offset will be ignored For many reasons including the fact that daylight savings transitions are more manageable it is better to set the RTC to UTC however some users prefer the clock to run in local time See the documentation for rtc_timezone for more details To do this use the function lookup feature in Dynamic C or refer to the Dynamic C Function Reference Manual 162 TCP IP User s Manual 4 5 Sample Programs Sample programs demonstrating HTTP are in the Samples Tcpip Http directory There is a configuration block at the beginning of each sample program The macros in this block need to be changed to reflect your network settings Starting with Dynamic C 7 30 setting up the network addresses is both more co
282. rther HTTP calls after calling this function It should clean up any resources that it opened since no further calls are made to this CGI for this request PARAMETERS state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE 0 LIBRARY HTTP LIB SEE ALSO http _getAction http_skipCGI http _switchCGI http finishCGI http_write Chapter 4 HTTP Server 205 http addfile int http addfile char name long location DESCRIPTION Adds a file to the dynamic resource table PARAMETERS name Name of the file for example index htm1 location Address of the file data Return value from ximport RETURN VALUE 0 Success 1 Failure LIBRARY HTTP LIB SEE ALSO http _delfile 206 TCP IP User s Manual http contentencode char http contentencode char dest const char src int len DESCRIPTION Converts a string to include HTTP transfer coding tokens such as amp 64 decimal for at sign where appropriate Encodes these characters lt gt amp Source string is NULL byte terminated Destination buffer is bounded by len This function is reentrant PARAMETERS dest Buffer where encoded string is stored sre Buffer holding original string not changed len Size of destination buffer RETURN VALUE dest There was room for all conversions NULL Not enough room LIBRARY HTTP LIB SEE ALSO http_urldecode Chapter 4 HTTP Server 207
283. rts is network configura tion uploading web pages changing variables for use with web pages sending mail and access to the console through a telnet client Please note that all libraries needed by zconsole 1ib must be included with use statements before the use statement for the Zconsole library The following code is taken from tcpipconsole c Size of the buffers for serial port C If you want to use another serial port you should change the buffer macros below appropriately and change the console_io array below sie define CINBUFSIZE 1023 define COUTBUFSIZE 255 Maximum number of connections to the web server This indicates the number of sockets that the web server will use 7 define HTTP MAXSERVERS 2 Maximum number of sockets this program can use The web server is taking two sockets the mail client uses one socket and the telnet interface uses the other socket E define MAX SOCKETS 4 All web server content is dynamic so we do not need http flashspec y define HTTP NO FLASHSPEC The file system that the console uses should be located in flash define FS FLASH The function prototype for a custom command must be declared before the console command array S ime hello world ComsoqileSitace ssrtate p Chapter 11 General Purpose Console 373 The following code is for Zconsole configuration ji The number of console I O streams that this program
284. rver bit should be set rootdir This field is a pointer to the root directory This is usually if the whole namespace is tobe accessible Otherwise it may be for ex ample A to restrict access to just the first DOS FAT partition The first and last character must be cwd This field is an array containing the current working directory This would normally contain the root directory as a prefix The first and last character must be dfltname This field points to a file name to be used as a resource name suffix when the first parameter refers to a directory name The ServerContext structure helps support more powerful resource access control It is needed by several of the new API functions that deal with resource retrieval and control as well as functions that perform directory navigation There are two functions that return a ServerContext struct http getcontext and http _getContext The latter is for use in CGI functions These functions can be used with other API functions that need the context structure For example sspec open MyFile http getcontext servno O READ 0 will open MyFile for reading for the server instance identified by servno 36 TCP IP User s Manual 3 1 7 SSpecStat Structure This structure holds status information about a file resource It is filled in by the function sspec_stat The fields of SSpecStat are flags A 16 bit mask that passes info
285. s use filesystem 1lib If using the improved file system available with Dynamic C 7 05 substitute fs2 lib for filesystem lib use zconsole 1lib Using the file system is no longer necessary 11 1 2 TCP IP and Zconsole Dynamic C TCP IP functionality may be used by a Zconsole application program by including the statement use dcrtcp lib in the program Other TCP IP protocols may be added with use statements of the appropriate libraries Chapter 11 General Purpose Console 343 11 2 Login Name and Password There is a sample program Samples tcpip LOGINCONSOLE C that demonstrates the use of the login name password functionality for Zconsole Zconsole command functions con_loginname con_loginpassword and con_logout are described in Section 11 4 1 1 starting on page 347 The structure that saves the name and password information can be backed up using the backup macro CONSOLE BACKUP LOGIN Please see Section 11 7 starting on page 368 for details on the backup system 11 3 Zconsole Commands and Messages Zconsole is a command driven application A command is issued either at the keyboard using a terminal emulator or a command is generated and sent from an attached machine Zconsole carries out the command and either the message OK r n is returned or an error is returned in the form of ERROR XXXX This is an error message r n Note that the carriage return and new line characters r
286. s 1 Failure no room LIBRARY HTTP LIB SEE ALSO shtml delvariable 264 TCP IP User s Manual shtml delfunction int shtml delfunction char name DESCRIPTION Deletes a function from the RAM resource table PARAMETERS name Name of the function as given to shtml_addfunction RETURN VALUE 0 Success 1 Failure not found LIBRARY HTTP LIB SEE ALSO shtml _addfunction Chapter 4 HTTP Server 265 shtml delvariable int shtml delvariable char name DESCRIPTION Deletes a variable from the RAM resource table PARAMETERS name Name of the variable as given to shtml_addvariable RETURN VALUE 0 Success 1 Failure not found LIBRARY HTTP LIB SEE ALSO shtml addvariable 266 TCP IP User s Manual 5 FTP Client The library FTP_CLIENT LIB implements the File Transfer Protocol FTP for the client side of the connection This library supports a single FTP session at any one time since the session state is maintained in a single global structure in root memory You can upload and download files to either a static buffer in root data memory for simple appli cations or starting with Dynamic C version 7 20 you can have the data passed to or generated by a data handler callback function that you specify The data handler function can implement large file transfers in extended memory buffers or it can be used to generate or process data on the fly with mi
287. s 296 Configuration Macros 339 ftp_tick DIFENNET ERONEN RODERES veliece singe voli ee tine 297 API Functions 339 6 4 Sample FTP Server sess 298 telnet Tt ssc ocasonvadeinocsemectivcnoenseeese 339 6 5 Getting Through a Firewall 299 ae E ER ore rer weet eR ai telnet_ClOSE cccesecceceseeseeevceveeeee 6 6 FTP Server Commands 299 An Example Telnet Server 341 6 7 Reply Codes to FTP Commands 301 An Example Telnet Client 342 T s TFTP Client sined i eeeeeeeee 303 11 General Purpose Console 343 7 1 BOOTP DHCP pinen ese 303 11 1 Zconsole Features cece cesses 343 7 2 Data Structure for TFTP 00 0 0006 304 File System Requirement 343 7 3 API PUNCHONS Aca ciccerca tities deeds 304 TCP IP and Zconsole 343 CHOP AMIE sess seesistscsselittsscue seasons 305 11 2 Login Name and Password 344 ee a Sia wis ties ess dee te oobsodeteoees lmureeees ae 11 3 Zconsole Commands and Messages 344 i ee 308 Zconsole Command Data Structure 344 tftp_exec Lakh i elas 309 11 4 Zconsole Command Array 0 346 8 SMTP Mail Client 311 Zconsole Commands 346 8 1 Sample Conversation eeeeeeceerees 311 Us Rent eres Stes 5 Zconsole nterface eeceeeeeeeeee 8 2 SMTP AMENN CAH ON ste EN 312 How to Include an T O Method 356 8 3 Sample Sending of an E mail 313 Predefined I O Methods 356 8 4 Configuration MacroS ceseeeeeeneees 314 Multiple I O Str
288. s for each CGI instance Your appli cation decides how many cond variables there are by defining the HTTP MAX COND macro which defaults to 4 Each cond variable is a 16 bit integer There is also a single integer variable accessed using http _getState and http _setState Chapter 4 HTTP Server 189 Expanding on the above let s add opening of the file define COND HANDLE 0 cond variable for storing the handle case CGI START if http getField s 0 printf Found a file to upload n http setCond s COND HANDLE sspec open http getField s http getContext s O WRITE O CREAT O TRUNC 0 if http _getCond s COND HANDLE lt 0 http skipCGI else http skipCGI s break The sspec_open function opens the file whose name is in the field name with write access The http _getcontext function returns a server context structure which is required for the sspec_open call The context structure contains some details such as the current user ID but the details are usually not relevant to the CGI function itself The file is created if it does not exist and it is initially truncated if it already exists The return value from sspec_open is stored in the cond variable COND_ HANDLE which is a macro we defined to zero so we wouldn t have to remember hard coded numbers The return value is either negative if there was an error or not negative in which case it is a valid file handle We
289. s function adds a name server to the list of name servers unlike con_set_nameserver that clears the list of name servers and adds one name server A command that use this function takes one parameter the IP address of the name server in dotted quad notation con_createv This function creates a variable that can be used with SSI commands in SHTML files Certain SSI commands can be replaced by the value of this variable so that a web page can be dynamically altered without re uploading the entire page Note however that the value of the variable is not preserved across power cycles although the variable entry is still preserved That is the value of the variable may change after a power cycle It can be changed again though with a putv com mand It works in the following fashion if the command is called CREATEV usage createv lt varname gt lt vartype gt lt format gt lt value gt strlen A web variable that can be referenced within web files is created lt varname gt is the name of the variable lt vartype gt is the type of the variable INT8 INT16 INT32 FLOAT32 or STRING lt format gt is the printf style format specifier for outputting the variable such as d lt value is the value to assign the variable strlen is only used if the variable is of type STRING It is used to give the maximum length of the string con_delete This function deletes a file from the file system A command that uses thi
290. s function takes one parameter the name of the file to delete con_echo This function turns on or off the echoing of characters on a particular I O stream That is it does not affect echoing globally but only for the I O stream on which it is issued A command that uses this function takes one parameter ON OFF Chapter 11 General Purpose Console 347 con_get This function displays a file from the file system It works in the following fashion if the com mand is called GET e ASCII mode usage get lt filename gt The file is then sent followed by the usual OK message e BINARY mode usage get lt filename gt lt size in bytes gt The message LENGTH lt len gt will be sent indicating length of the file to be sent and then the file will be sent but not more than lt size in bytes gt bytes con_getv This function displays the value of the given variable The variable is displayed using the printf style format specifier given in the createv command A command that uses this function takes one parameter the name of the variable con_help This function implements the help system for Zconsole A command that uses this function takes one parameter the name of another command Zconsole outputs the associated help text for the requested command The help text is the text file referenced in the third field of the Console Command structure con_list_files This function lists the files in the fi
291. s includes things like selection of the appropriate library mod ules initialization of static constant data structures and tables selecting default network con figuration and inclusion of static resources external files via the ximport or zZimport directives The arrows leading from the Compile Time Initialization sub block indicate the tables that may be set up at compile time namely e The MIME type mapping table This mandatory table indicates to the browser how the content is to be presented to the user This is necessary for the browser and needs to be specified by the server however the server does not need to be particularly aware of the details The rule table This is only necessary if a filesystem is in use It is used by the resource manager to apply access permissions to the resources contained in a filesystem This is necessary because not all filesystems can associate file ownership and access rights with individual files The static resource table This is the classic method of defining resources in Dynamic C This table is optional since all necessary resources may be loaded in a filesystem or in the dynamic resource table Most applications will contain at least a few static resources as an initial default or fallback or for data that will never change such as a logo image e Program flash This really represents the loading of resource files into program memory via the ximport directive There will al
292. s new spec entry This function is currently only useful for the HTTP server PARAMETERS name Name of the new variable This must be unique but this function does not check The name should not conflict with the virtual file system hierarchy That is it should not start with fs2 A B etc Variables appear in a directory listing of the root directo ry however they cannot be opened using sspec_open variable Address of actual variable type Variable type one of e INTS8 single character e INT16 2 byte integer e PTR16 string in root memory e INT32 4 byte long integer e FLOAT32 floating point variable format Output format of the variable as a printf conversion specifi er e g d servermask Bitmask representing servers for which this function will be valid currently only useful with SERVER HTTP RETURN VALUE 1 Failure 20 Success the index of the variable in the resource list LIBRARY ZSERVER LIB SEE ALSO sspec_addfsfile sspec_addrootfile sspec_addxmemfile sspec_addxmemvar sspec_addfunction sspec_addform sspec_aliasspec 68 TCP IP User s Manual sspec addxmemfile int sspec addxmemfile char name long fileloc word servermask DESCRIPTION Adds a file located in extended memory to the RAM resource list Make sure that SSPEC_MAXSPEC is large enough to hold this new entry PARAMETERS name Name of the new file This must be unique but this function does not c
293. s of the server to connect to as returned from resolve RETURN VALUE 0 Success 1 Failure LIBRARY POP3 LIB 328 TCP IP User s Manual pop3 tick int pop3 tick void DESCRIPTION A standard tick function to run the daemon Continue to call it as long as it returns POP PENDING RETURN VALUE POP PENDING Transfer is not done call pop3_ tick again POP SUCCESS All e mails were received successfully POP_ERROR Unknown error occurred POP TIME Session timed out Try again or use POP_ TIMEOUT to increase the time out length LIBRARY POP3 LIB Chapter 9 POP3 Client 329 9 5 Sample Receiving of E mail This program connects to a POP3 server and downloads e mail from it Program Name Samples tcpip pop3 parse_extra c define TCPCONFIG 1 define POP HOST mail domain com Name of your POP3 server define POP USER myname Username for POP3 account define POP PASS secret Password for POP3 account define POP PARSE EXTRA memmap xmem fuae dortop lib use pop3 lib SLiaye p int storemsg int num char to char from char subject char body int len GLOBAL INIT n 1 iea ls mom i n num printf RECEIVING MESSAGE lt d gt n n print tFrom s n from prime VA cros Sea TO print tSubject s n subject print MSG UDATAS ee ml body wie wen 0 main static long address SISEE IC wine Iie 4 Soek iane p
294. s to no authentication method re quired SSPEC MAX FATDRIVES Determine the maximum number of independent FAT filesystem drives Defaults to 1 Each drive takes 8 bytes of root storage plus whatever is required by the filesystem itself Each drive can have up to 4 partitions This macro is only relevant if you use the FAT library SSPEC MAXNAME Define the maximum name length of each dynamic or static resource Defaults to 20 You can minimize memory usage by choosing short names for all resources and reduc ing the value of this macro SSPEC MAXRULES Define the maximum number of dynamically added rules Defaults to 10 but you can explicitly define it to zero if all the rule table entries are static see SSPEC RULETABLE macros Each rule takes up 13 bytes of root storage plus whatever storage is required for the realm and prefix strings which must be null termi nated and in static storage since pointers to these are stored in the rule table SSPEC MAXSPEC Define to the number of dynamic RAM resource table entries to allocate for the global array server spec Each entry takes SSPEC_MAXNAME 23 bytes of root mem ory or SSPEC_MAXNAME 33 if FORM_ERROR_ BUF is defined Defaults to 10 entries approximately 530 bytes Do not set higher than 511 40 TCP IP User s Manual SSPEC MAX OPEN Determine the maximum number of simultaneously open resources Defaults to 4 Choose this number carefully since eac
295. seeseeeeen 263 P shtml_addvariable cccccccceseseseeeee 264 Stal delRGRGHORY csc 2h oc ean ot ces 265 passive P a e N EEE E P shtml_delvariable ccccssssssesssssssseseseen 266 i paa i a Spee Se OUNCE e tees E E E aise or PE EEE E oct 40 Spec OnE CR ACCESS i oG a iam erat T3 POP_BUFFER_SIZE iiini 325 Spec Be URE ncaa Rene gi FOZ POP DEBUG iniinis 325 Spec a ae a H POP NODE ETE Men ccc ower rs cn 325 TCP IP User s Manual 381 POP_PARSE_EXTRA caeca e 325 POP3 client configuration essseeessesessesreerrreersreererrseesersese 325 POST command 0 cccccsesccccesessesececeeenenteeeees 172 R resources ACCESS controls ooo eeeeeseecceceeessececeeesensceeeeeeeneee 16 mule ta blestsetetts nissccieitesscbebit estes es 16 S sample programs FTP Serye reren n R s 298 POP3 Chente neet ea 330 SMTP client nains ereire 313 telnetehent pirrer eein E as 342 t l et SEVER rennen A n a i 341 WAIN S PAEO OE POEET EREE 373 SAUTH_MAXNAME uc eccecceeseeeeteeeeeeee 39 SAUTH_MAXUSERS cee eceescesseeeeeteeeeeees 40 SOCUPLY oin A Ag ee ieee 161 SERIAL_PORT_SPEED eee eeeteeees 339 Server SPEC list eee esses an anei 33 36 SERVER_PASSWORD_ONLY uu eee 40 SMTP client 0 cc6c hic a 311 323 SMTP configuration Macros 0 0 eee eee eee 314 SSI inden ela aidan ais 158 168 SOL ch Secgechive thine eee ne aes 161 SSPEC_MAX_FATDRIVES cceeeseeeeee 40 SSPEC_MAX_OPEN ehe erui in 41 SSPEC_MAXNAME
296. ser s Manual tftp init int tftp init struct tftp state ts DESCRIPTION This function prepares for a TFTP session and is called to complete initialization of the TFTP state structure Before calling this function some fields in the structure tftp state must be set up as follows ts gt state lt 0 for read 1 for write gt ts gt buf_addr lt physical address of xmem buffer gt ts gt buf len lt length of physical buffer 0 65535 gt ts gt my tid lt UDP port number Set 0 for default gt ts gt sock lt address of UDP socket udp Socket or NULL to use DHCP BOOTP sockets lt IP address of TFTP server host or zero to use default BOOTP host gt ts gt mode lt one of the following constants TFTP MODE NETASCII ASCII text TFTP MODE OCTET 8 bit binary TFTP MODE MAIL Mail gt strcpy ts gt file lt remote filename or mail address gt ts gt rem_ip Note that mail mode can only be used to write mail to the TFTP server and the file name is the e mail address of the recipient The e mail message must be ASCII encoded and formatted with RFC822 headers Sending e mail via TFTP is deprecated Use SMTP in stead since TFTP servers may not implement mail PARAMETERS ts Pointer totftp state RETURN VALUE 0 OK 4 Error default socket in use LIBRARY TFTP LIB Chapter 7 TFTP Client 305 tftp initx int tftp initx long ts_addr DESCRIPTION This function is called to c
297. ser can change values in the form But how does this changed data get back to the HTTP server By using the HTTP POST command When the user presses the Submit button the browser connects to the HTTP server and makes the follow ing request POST myform HTTP 1 0 some header information Content Length 19 where myform is the CGI program that was specified in the ACTION attribute of the FORM tag and POST is the METHOD attribute of the FORM tag Content Length defines how many bytes of information are being sent to the server not including the request line and the headers Then the browser sends a blank line followed by the form information in the following manner temphi 80 amp templo 65 That is it sends back name and value pairs separated by the amp character There can be some further encoding done here to represent special characters but we will ignore that in this explana tion The server must read in the information decode it parse it and then handle it in some fash ion It will examine the new values and assign them to the appropriate C variables if they are valid 4 5 3 2 POST Style Form Submission If an HTML file specifies a POST style form submission that is METHOD POST the form will still be waiting on the socket when the old style CGI handler is called Therefore it is the job of the CGI handler to read this data off the socket and parse it in a meaningful way The sample files Post
298. serid sauth_ getuserid foo SERVER FTP sspec_cd A amp ctx for item 0 item gt 0 item sspec dirlist item buf sizeof buf amp ctx SSPEC_LIST_ LONG if item gt 0 printf buf finished now can re use ctx Chapter 3 Server Utility Library 79 To iterate through the first 5 resources only opts SSPEC LIST LONG for item 0 n 0 item gt 0 4n if n gt 4 opts SSPEC_LIST_END item sspec dirlist item buf sizeof buf amp ctx opts if item gt 0 printf buf PARAMETERS item Directory entry to list If zero this always returns the first entry in the directory Thereafter pass the return value from the previous call to this function to get the next item s NOTE the return value does not necessarily count up 1 2 3 etc Apart from 0 the only values you should pass in this parameter are previous return val ues otherwise the results will be undefined line Points to buffer that is filled with resulting string The string will be terminated with r n CRLF then a NULL linelen Length of the above buffer If it is not long enough then the line will be truncated however it will still have the terminating CRLF null The minimum reasonable value is about 15 for format 0 and 80 for format 1 context Server context This structure will have the following fields initial ized userid current user who is doing the listing or 1 if no spe cif
299. set_txt SET GATEWAY con_set_gateway help set_txt SET NAMESERVER con_set_ nameserver help set_txt SET MAIL NULL help set_mail_txt SET MAIL SERVER con_set_mail_server help _set_mail_server_ txt SET MAIL FROM con_set_mail_ from help set_mail_from_txt SHOW con_show help show txt PUT con put help put_txt GET con_get help get txt DELETE con_delete help delete txt LIST NULL help list _txt LIST FILES con_list files help list_txt LIST VARIABLES con_list_variables help list _txt CREATEV con_createv help createv_txt PUTV con_putv help putv_txt GETV con_getv help getv_txt MAIL con mail help mail _txt RESET FILES con_reset files 0 RESET VARIABLES con reset variables help reset variables ODD ON ON ON OO OO OO OO OO OO om Oo oo oo oo oo ee oo oo a 346 TCP IP User s Manual 11 4 1 1 Default Command Functions The following functions are provided in Zconsole 1ib Each one takes a pointer to a Con soleState structure as its only parameter following the prototype for custom functions described in Section 11 4 1 2 on page 352 Each of these functions return 0 when it has more pro cessing to do and thus will be called again 1 for successful completion of its task and 1 to report an error Parameters needed by the commands using these functions are passed on the command line con_add_nameserver Thi
300. shown on the diagram since it would add need less complexity Your application can directly call functions in the HTTP server in the resource manager Zserver in TCP IP and just about anywhere else One very clean and pow erful interface is provided via web variables This is a new add on module in Dynamic C 8 50 CGI functions CGI stands for Common Gateway Interface however this acronym has a more specific use in Dynamic C it refers to a C function that is called by the HTTP server to generate some dynamic content for the browser This is the only truly optional block Many applications can be written without resorting to CGI functions however there are some cases where the power and flexibility of a CGI will be required Prior to Dynamic C 8 50 writing a robust CGI was the most difficult part of the entire process From 8 50 there is a new style of CGI writing that simplifies the process and reduces the chances of error The old style of CGI is still supported for backwards compatibility 2 3 2 HTTP Block Let us now progress to the HTTP server itself In the diagram this is the block with two circles inside The server is responsible for fielding requests from the outside world Each request is ana lyzed to determine the resource that is being requested the user who is making the request and whether the user is authorized to obtain that resource If the resource is available the user is known and has the proper permi
301. sk oe 2 211 Sere pert aSpa A http_finderrbuf s scodeseasthecs tsetse ace 212 FTP Sefv fe nuerai 277 cco a oy 6 1 Configuration Macros s ssssssssseseeeees 278 http_getAction eee eeeeeeees 215 6 2 File Handlers eee ein 280 iv TCP IP User s Manual Replacing the Default Handlers 280 pop3_getmail eee 328 File Handlers Specification 280 POPS2UICK nnrir isese 329 ftp_dflt_open x sin keshet scala teccuaeetuesst 281 9 5 Sample Receiving of E mail 330 ftp_dflt_getfilesize eee 282 Sample Conversation 331 ftp_dflt_read eee eeeeeeseeeneeeeeee 283 ftp_dflt_Write oo 284 10 Telhet n a A 333 ftp_dflt_close EEA A EET 285 10 1 Telnet Dynamic C 7 05 and later 333 ftp dft Stinen eani 286 Setup 333 ftpodflt ca e aa 287 API F D ic C 7 05 and ftp dft pwd oionn 288 unctions Dynamic C 7 05 an Hip dilemma this 5342 seceeeuens ata 289 later 334 ftp_dflt_delete ee eee eeseeeneeeeeee 290 vserial_ClOSE ecececeeeseeesesereeeeeeees 334 6 3 API Punictionss s 0iacnuee caensiate 291 yserial_init scisesu cterpontesseoctvnest arate 334 ftp_dflt_is_auth 291 vserial_keepalive oe eee eee 335 e veri listen nenene 336 ftp_load_filenames ae eee sees 293 se aa Bs achat crtas Mates ESA 337 ftp_save_filenames csssssssseeeseeeee 294 vserial_tick cssssrreeeeeeseeeenesnannes 338 ftp_set_anonyMOUS cceeeeeee 295 10 2 Telnet pre Dynamic C 7 05 339 ftp_Shutdown ee ceeeeceeeeesteeeeeeee
302. spec DESCRIPTION Returns a pointer to the variable in xmem represented by the sspec index PARAMETER sspec spec index RETURN VALUE 2 0 Variable pointer 1 Failure SEE ALSO sspec_readvariable Chapter 3 Server Utility Library 113 sspec mkdir int sspec mkdir char name ServerContext context DESCRIPTION Create a named directory in the FAT filesystem PARAMETERS name Name of new directory context Current server context RETURN VALUE 0 OK EPERM Not a filesystem that supports creation of new directories EACCES Not authorized Any other negative values indicate an error SEE ALSO sspec delete sspec_rmdir sspec_open 114 TCP IP User s Manual sspec needsauthentication int sspec needsauthentication int sspec DESCRIPTION Checks if the item represented by the spec entry needs authentication for access This is defined by having a non NULL realm string for the resource This function is deprecated starting with Dynamic C 8 50 in favor of sspec_checkpermissions It is retained for cases where the permissions structure for a resource contains an authentication method of SERVER _AUTH_ DEFAULT PARAMETERS sspec spec index RETURN VALUE 0 Does NOT need authentication 1 Does need authentication 1 Failure no permissions struct assigned or invalid sspec handle LIBRARY ZSERVER LIB SEE ALSO sspec_getrealm sspec_checkpermissions Chapter 3 S
303. sponsibility of the system designer to incorporate redun dant protective mechanisms appropriate to the risk involved The Dynamic C TCP IP software is designed for use only with Rabbit Semiconductor chips Index Symbols F Fecho VAP ves 5 sep cei es icone n a RE 168 file extensions cccccececssseceeceeseseceeeeesenees 32 164 HEX CC CMA n a e ei n E ER 168 file Handlers srein anA earnen 280 P include fessonia a 168 filesize n ee E E TAS 270 PS CraNSlEk an ennnen ea 268 A firewalla e as ERE SR 299 anonymous login ssssssssessesessessssssseessssseesesteetee 277 flow control AE EACAN TETIT TENESTE ENE 367 application protocols FIP ehenta kh ies 267 275 FTP client cx cease ee oc ene ae 267 FTP Server seeesseeseeeeeeeererereerrerereerrien 277 301 FTP SeTVer acd es catatedatiasuicveroaoseans 277 FTP server commands sussiste 299 300 HTTP 153 Function Reference POP3 client 325 Authentication and Identification SMTP client aanren 311 sauth adder rnc 46 ARS NA E eR Sh ss BaD 333 sauth_authenticate essences 47 TFTP clichbay an wcnncniakvesmnnones 303 Sauth_getpassword ersrssesssseseesesseeenserseeee a6 Authentication sauth_getserver E E EEEE EESE 48 HRPA a ae Once eee 161 sauth_getuserid ssesevsrerssssseressererensseee 49 NTE AAE E Mas 312 sauth_getusermask esssersssssereseeeerersseee 50 sauth_getusername sseeseeseseeeeeseeseeeeee 51 B sauth_getwriteaccess sssseseseeseeseesseeeeee 52 a SaUth_LE
304. ss sauth_setusermask sauth_setwriteaccess sauth_removeuser 46 TCP IP User s Manual sauth authenticate int sauth authenticate char username char password word server DESCRIPTION Authenticate user and return the user index representing the authenticated user that is the user table index This performs only a plaintext comparison of the userid and pass word Servers probably will have their own more sophisticated checks Ifusername is NULL or empty string then password only matching is attempted for servers who allow this type of authentication as defined by the SERVER PASSWORD ONLY macro PARAMETERS username Name of user password Password for the user server The server for which this function is authenticating e g SERVER _HTTP SERVER_FTP RETURN VALUE 1 Failure or user not authorized 20 Success array index of the ServerAuth structure for authenticated user LIBRARY ZSERVER LIB SEE ALSO sauth_adduser Chapter 3 Server Utility Library 47 sauth getpassword sauth getpassword int userid DESCRIPTION Get the password for a user PARAMETER userid user index RETURN VALUE NULL password string NULL Failure LIBRARY ZSERVER LIB SEE ALSO sauth_setpassword sauth getserver int sauth getserver int sauth DESCRIPTION Returns whether or not a user is visible to particular server s PARAMETER sauth user index RETURN VALUE 0 This user is v
305. ssions then the resource is transmitted back to the browser Following the above steps in more detail we have l Analyze the request obtain the resource name Part of the information provided by the browser is a request header that contains a URL Uniform Resource Locator The URL is simply the name of the resource to retrieve URLs typically look like a file name in a Unix style filesys tem that is component directory and file names separated by slash characters Obtain the user ID The browser has the option of sending the username and password of its user If it does not do this then the userid is anonymous If this is not good enough then the browser can always try again when it is denied a protected resource On receipt of user creden tials name and password the HTTP server consults the resource manager which in turn looks up the rule table to see if the user s credentials are OK If they are then the resource manager also determines the group s of which this user is a member Thereafter all access and permis sion checking is based on the group not the individual user Return the resource Having verified the group access rights if necessary the resource is transmitted back to the user The resource may be an HTML or image file obtained from pro gram memory or a filesystem or it may be a script file that is processed on the fly to generate markup language It may even represent a CGI funct
306. st parameter to the CGI function dp Pointer to buffer containing data to be written len Maximum number of bytes to write to the socket RETURN VALUE gt 0 the number of bytes written 1 error LIBRARY HTTP LIB Chapter 4 HTTP Server 251 http sock gets int http sock gets HttpState state byte dp int len DESCRIPTION HTTP wrapper function for sock_ gets This function can be used by CGI appli cations to retrieve a string waiting on an ASCII mode socket associated with a partic ular HTTP server PARAMETERS state HTTP state pointer as provided in the first parameter to the CGI function dp Pointer to return buffer len Maximum size of return buffer RETURN VALUE 0 if buffer is empty or if no r or n is read but buffer had room and the connection can get more data gt 0 is the length of the string 1 error LIBRARY HTTP LIB SEE ALSO http_sock_mode 252 TCP IP User s Manual http sock mode void http sock mode HttpState state http sock mode t mode DESCRIPTION HTTP socket wrapper function for socket mode This function can be used by CGI ap plications to set the mode of a socket associated with a particular HTTP server PARAMETERS state HTTP state pointer as provided in the first parameter to the CGI function mode HTTP mode to use for the socket Valid values for mode are e HTTP MODE ASCTI Sets the associated socket to ASCII mode HTTP MODE BINARY Sets the
307. strict access to just first DOS FAT partition First and last char must be char cwd char dfltname ServerContext Current working directory Normally includes rootdir as a prefix First and last char must be A file name to be used as a resource name suffix in the case that the first parameter refers to a directory name mode Resource opening mode Bitwise OR of the following macros O READ open for reading O WRITE open for writing implies reading as well e O CREAT with O WRITE if file does not exist then cre ate it with zero length and allocation O TRUNC with O WRITE if file already exists truncate it to zero length O APPEND with O_WRITE if file already exists posi tion at end of file so as to append new data You can later seek to the existing portion of the file Chapter 3 Server Utility Library 117 RETURN VALUE 20 Success The returned value should be passed to other functions that require a general handle such as sspec_read sspec_seek sspec_write sspec tell andsspec_close The following return values are negatives of the values defined in errno 1lib ENOENT The resource was not found when it was expected to exist EACCES The context gt userid field was not 1 and the specified user is not allowed to access the resource using the specified mode EINVAL The resource name was malformed e g too lo
308. supports Since we are supporting serial port C and telnet there are two I O streams ay define NUM CONSOLES 2 If this macro is defined then the version message will be shown with the help command when the help command has no parameters a define CON HELP VERSION Defines the version message that will be displayed in the help command if CON HELP VERSION is defined a7 define CON VERSION MESSAGE TCP IP Console Version 1 0 r n jf Defines the message that is displayed on all I O channels when the console starts Sy define CON_INIT_MESSAGE CON VERSION MESSAGE The ximport directives include the help texts for the console commands Having the help text in xmem helps save root code space sy ximport samples zconsole tcpipconsole_help help txt help txt The rest of the ximport statements may be seen in tcpipconsole c 374 TCP IP User s Manual The following code sets up all the data structures needed by the console The console will be available to the I O streams given in the following array The I O streams are defined through macros as documented in Section 11 5 2 The parameter for the first macro represents the initial baud rate for serial port C The second macro is passed the port number for telnet If you change the number of I O streams update NUM_CONSOLES above const ConsoleIO console iol CONSOLE IO SERC 57600 CONSOLE IO TELNET 23 N w E E
309. t this marks the end of data and gives the function an opportunity to e g close the file Called after either in or out process ing e FTPDH_ ABORT end of data error encountered during FTP operation Similar to END except the transfer did not complete Can use this to e g delete a partially written file The return value from this function depends on the in out flag For FTPDH_IN the function should return len if the data was processed successfully and download should continue 1 if an error has occurred and the transfer should be aborted For FTPDH_ OUT the function should return the actual number of bytes placed in the data buffer or 1 to abort If zero is returned then the upload is terminated normally For FTPDH_END the return code should be zero for success or 1 for error If an error is flagged then this is used as the return code for ftp_client_tick For FTPDH_ABORT the return code is ignored 272 TCP IP User s Manual ftp data _ handler continued PARAMETERS dhnd Pointer to data handler function or NULL to remove the current data handler dhnd data A pointer which is passed to the data handler function This may be used to point to any further data required by the data handler such as an open file descriptor opts Options word currently reserved set to zero LIBRARY FTP CLIENT LIB SEE ALSO ftp client setup Chapter 5 FTP Client 273 ftp last code int ftp last _code void DESCRIPT
310. t conio gt puts Hello World r n return ils void main void Initialize TCP IP clients servers and I O prior to using any console functions sock init tcp reserveport 80 Start a listen queue and disable the 2MSL wait meco iaie g wi iis imie OQ 64 printf Filesystem not present n it congole imic l 0 1 primen Console did not initialize n fs format 0 64 1 After the file system has been initialized or formatted space must be reserved in the file system for the backup information con backup reserve con_backup Save the backup information to the console wile aaa 4 console tick http handler 376 TCP IP User s Manual Notice to Users Z WORLD PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYS TEMS UNLESS A SPECIFIC WRITTEN AGREEMENT REGARD ING SUCH INTENDED USE IS ENTERED INTO BETWEEN THE CUSTOMER AND Z WORLD PRIOR TO USE Life support devices or systems are devices or systems intended for surgical implantation into the body or to sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling and user s manual can be reasonably expected to result in significant injury No complex software or hardware system is perfect Bugs are always present in a system of any size In order to prevent danger to life or prop erty it is the re
311. t partition structure if a default partition could be located on the drive If fat 1ib is not included the above structure is still defined but contains 6 void pointers This is just to avoid compilation problems since no information will be used or returned fs2stuff This parameter is currently reserved for returning FS2 informa tion For now pass as NULL reserved Reserved for other filesystems For now pass as NULL RETURN VALUE 0 OK Otherwise if a filesystem fails to mount the return code is the bitwise OR of the SSPEC_MOUNT_ constants of those filesystem s that failed to initialize SEE ALSO sspec _fatregister sspec_ fatregistered Chapter 3 Server Utility Library 73 sspec cd int sspec cd char path ServerContext context int check DESCRIPTION Change the current working directory in the ServerContext structure This func tion may be used by servers that support the concept of a current directory suchas FTP but not HTTP Standard Unix like path names are used including support for and directory components The resulting directory name is not allowed to be closer to the root directory than context gt rootdir If there is any specification error then the current directory is not changed The resulting absolute directory name cannot be longer than SSPEC_MAXNAME including a leading and trailing character PARAMETERS path New directory path string as a null terminated
312. t was actually configured If the type of authentication that you ask for was not compiled in at compile time then the type of authentication will not be changed NOTE this function only sets the default authentication method for resources who have their authentication method set to SERVER_AUTH_DEFAULT or none speci fied PARAMETERS auth Type of authentication Choices are e HTTP _NO AUTH e HTTP BASIC AUTH e HTTP DIGEST AUTH RETURN VALUE Actual resulting type of authentication LIBRARY HTTP LIB 242 TCP IP User s Manual http setCond int http setCond HttpState state int idx int val DESCRIPTION Set the value of an HTTP condition state variable aka cond variable There are HTTP _MAX_ COND of these integer state variables thus idx must be between 0 and HTTP MAX COND 1 inclusive NOTE This is implemented as a macro PARAMETERS state HTTP state pointer as provided in the first parameter to the CGI function idx Index of cond variable 0 HTTP_MAX COND 1 Validity is not checked val New value RETURN VALUE Returns the new value of the cond variable i e val LIBRARY HTTP LIB SEE ALSO http _getAction http _getCond Chapter 4 HTTP Server 243 http setcookie void http setcookie char buf char value DESCRIPTION This utility generates a cookie on the client This will store the text in value into a cookie generation header that will be written to buf The header place
313. tCond s COND HANDLE get file handle len http getCond s COND LEN get place in file Try writing the part that wasn t written newlen sspec_write handle http getData s len http _getDataLength s len if newlen lt 0 permanent error when retrying sspec_close handle http_switchCGI s upld_err html else sum the total written count len newlen if len lt http_getDataLength s still haven t written all http_setCond s COND LEN len save new place return CGI_MORE tell server we re not done break Chapter 4 HTTP Server 195 The important point is that when CGI_ CONTINUE is the action code the CGI retries the failed part of the previous operation then tests whether it is complete On completion the usual 0 return code is returned otherwise the CGI keeps returning CGI_ MORE until the operation either completes or permanently fails The above code does not show the CGI returning zero Look at the code in the default handler http defaultCGI to see this being done You may notice the repetition of parts of this code for example the calls to http switch CGI This is for clarity you can condense some of this by factoring out the common parts The CGI remembers where it was up to by using another cond variable COND_ LEN This is all that is required since the contents of http_getData and its length are guaranteed not to be changed on th
314. ta 3vAL1Q0sFOUg2GsSY3p6n3YQO This is the first boundary Boundary strings are always prefixed by an additional sequence The following lines are header lines for the individual part The actual data follows the first empty line Content Disposition form data name A new htm filename test txt The Content Disposition header indicates the presentation of the data The only type which is rele vant is form data The name parameter indicates the field name which was originally part of the name parameter of the lt input gt element The filename parameter is only set if this is an uploaded file It gives the name of the file on the remote client side This is not usually relevant to the server The name of the file as it is stored on the server is not specified since the browser does not know it or have control over where the file is stored We are using the convention that the field name indicates the local file name but this is just a convention Content Type text plain Content Type indicates the type of information The default is plain i e ascii text however it could also be set to image gif for a GIF file text html for HTML etc The following blank line indicates the end of headers for this part test file contents first line This is the actual file or form field content 3vAL1QsFOUg2GsY3p6n3YQ The boundary string terminates the data for the previous part Headers for the next part immediately follow
315. ter e INT16 2 byte integer e PTR16 string in root memory e INT32 4 byte long integer e FLOAT32 floating point variable format Output format of the variable as a printf conversion specifi er e g Jd servermask Bitmask representing valid servers currently only useful with SERVER HTTP RETURN VALUE 1 Failure 20 Success the index of the variable in the resource list LIBRARY ZSERVER LIB SEE ALSO sspec_addfsfile sspec_addrootfile sspec_addvariable sspec_addfunction sspec_addform sspec_addxmemfile sspec_aliasspec 70 TCP IP User s Manual sspec aliasspec int sspec aliasspec int sspec char name DESCRIPTION Creates an alias to an existing ServerSpec structure Make sure that SSPEC_MAXSPEC is large enough to hold this new entry This is NOT a deep copy That is any file variable or form that the alias the new spec entry references will be the same copy of the file variable or form that already exists in the old spec entry This should be called only when the original entry has been com pletely set up NOTE do not attempt to alias a sspec handle that was returned by sspec_open because the handle may be dynamically allocated In such a case the alias will not work once the original handle is closed You can test whether such a virtual handle has been returned using the macro SSPEC_IS VIRT sspec PARAMETERS sspec sspec index that this function will alias name Alias name
316. th get store com mands as well as directory listings FTP EXTENSIONS The macro is not defined by default Define it to allow the server to recognize the DELE SIZE and MDTM commands If this macro is defined then the FTP handler structure FTPhandlers is augmented with pointers to mdtm and delete handlers FTP INTERFACE This macro defaults to IF_DEFAULT i e the single default interface Define to IF ANY if FTP sessions can be accepted on any active interface or a specific interface number e g F_ETHO to allow sessions on that interface only Note that you are cur rently limited to a single interface or all interfaces This macro is only relevant starting with Dynamic C version 7 30 FTP MAXLINE The default is 256 the number of bytes of the working buffer in each server This is also the maximum size of each network read write The default value of 256 is the min imum value that allows the server to function properly FTP MAXSERVERS The default is 1 the number of simultaneous connections the FTP server can support Each server requires a significant amount of RAM 4096 bytes by default though this can change through SOCK_BUF_SIZEor tcp_MaxBufSize deprecated FTP NODEFAULTHANDLERS This macro is undefined Define it to eliminate the code for the default file handlers You must then provide your own file handlers This macro is no longer needed starting with Dynamic C version 7 20 278 TCP IP User s Manual FTP TIM
317. the console 356 TCP IP User s Manual 11 5 2 3 Slave Port The Rabbit slave port is an 8 bit bidirectional data port Zconsole runs on the slave processor Two drivers are needed 11 5 2 3 1 Slave Port Driver The slave port driver is implemented by SLAVE_ PORT LIB For an application to use the slave port e The driver must be installed by including the library in the program e Acall to SPinit mode must be made to initialize the driver e A function to process Zconsole commands sent to the slave port must be provided The slave port has 256 channels separate port addresses that are independent of one another A handler function for each channel that is used must be provided For details on how to do this please see the Dynamic C User s Manual A stream based handler SPShandler to process Zconsole commands for the slave is pro vided in SP_STREAM LIB The handler is set up automatically by the console when the slave port I O method is included The macro CONSOLE _IO_SP expands to the I O functions defined in SP_STREAM LIB 11 5 2 3 2 Master Connected to Rabbit Slave Port The master controller board can be another Rabbit processor or something else The master also needs a driver for its end of the slave port connection An example of the software needed on the master is given in MASTER_SERIAL LIB The software on the master controller is of course specific to the task at hand In the example driver provided
318. the following codes e HTTP METHOD GET GET i e normal retrieval without making any per manent state update e HTTP METHOD POST POST i e uploading some information to be stored or making some permanent state change This is the normal method for invoking CGIs e HTTP METHOD HEAD HEAD i e the client only wants the headers not the actual content e g it might be trying to determine the most recent modifica tion date Other codes may be returned in the future LIBRARY HTTP LIB SEE ALSO http _getAction 226 TCP IP User s Manual http getHTTPVersion char http getHTTPVersion HttpState state DESCRIPTION Return the HTTP version number of the current request protocol The CGI might need to look at this in order to generate the correct response headers NOTE This is implemented as a macro PARAMETER state HTTP state pointer as provided in the first parameter to the CGI function RETURN VALUE One of the following codes e HTTP VER_09 version 0 9 e HTTP VER_10 version 1 0 e HTTP VER_11 version 1 1 Other codes may be returned in the future LIBRARY HTTP LIB SEE ALSO http _getAction Chapter 4 HTTP Server 227 http getRemainingLength long http getRemainingLength HttpState state DESCRIPTION Return the remaining length of the incoming data stream This length includes all parts not just the current part and also includes the boundary separators and epilog data
319. tive to the number of words that make up the name of the command itself but still maintain backwards compatibility with custom commands that use state gt numparams The function that implements the custom command should return 0 when it has more processing to do and thus will be called again 1 for successful completion of its task and 1 to report an error The third and final field of the console commands entry is the physical address of the help text file for the custom command in question This file must be ximported along with all of the default command function help files that are being used IMPORTANT The fields discussed in the previous paragraph and the fields that have comments in the structure definition are the only ones that an application program should change The other fields must not be changed 11 4 2 Zconsole Error Messages ZCONSOLE LIB provides a list of default error messages for the default Zconsole commands An application program must define an array for these error messages as well as for any custom error messages that are desired To include only the default error messages the following array is suffi cient const ConsoleError console errors CON_STANDARD_ ERRORS includes all default error messages Chapter 11 General Purpose Console 353 11 4 2 1 Default Error Messages These are the error codes for the default error messages and the text that will be displayed by the console if the err
320. tl gif SSPEC RESOURCETABLE END Compile and run the program Open up your browser to the new page for example http 10 10 6 100 newfile html and your new page will be displayed by the browser 4 5 1 2 Adding Files with Different Extensions If you are adding a file with an extension that is not html or gif you need to use the appropriate macros to make an entry in the MIMETypeMap structure for the new extension The first field is the extension and the second field describes the MIME type for that extension You can find a list of MIME types at ftp ftp isi edu in notes iana assignments media types media types In the media types document located there the text in the type column would precede the and the subtype column would directly follow Find the type subtype entry that matches your extension and add it to the http_types table 164 TCP IP User s Manual SSPEC MIMETABLE START SSPEC MIME html Wieescie Maewll SSPEC MIME pdf application pdf added this one SSPEC MIME gif image gif SSPEC MIMETABLE END 4 5 1 3 Handling of Files With No Extension The entry and files without an extension are dealt with by the handler specified in the first entry in the MIME table If you use the SSPEC_ MIME macro the default handler is used It passes the information verbatim You can also use the macro SSPEC_MIME_ FUNC to specify a non default text processor this is n
321. to initialize rce d n Proceeding anyway n rc sock init http init for se my_io_polling http_handler Chapter 2 Web Enabling Your Application 23 The first change is the addition of FAT _USE_FORWARDSLASH and FAT_BLOCK These are needed by Zserver to work with the FAT filesystem The definition of USE_HTTP_UPLOAD is needed for Zserver to use the file upload feature Next the libraries for the FAT fat 1ib and for the serial flash driver sflash_fat 1ib are brought in with use statements The MIME type mapping for CGIs is added to the MIME table with SSPEC_ RESOURCE CGI An empty string is the registered type for CGIs This makes sense since CGIs are not displayed by the browser Next we want to give the server access to the CGI function by creating an entry for it in the static resource table with SSPEC_RESOURCE_CGI The first parameter is a string that must match the string used in the FORM ACTION tag in the HTML code The second parameter identifies the CGI function that will be called when the form is submitted http defaultCGI isa CGI that is provided with the HTTP server It uploads files to a FAT filesystem shows a status page to the browser after the upload and allows the user to click back to the server s home page For a detailed description of the file upload feature see Section 4 6 Finally the FAT filesystem must be readied for use The call to sspec_ automount takes care of everyth
322. tup ftp _data_handler ftp client _xfer 270 TCP IP User s Manual ftp client xfer longword ftp client xfer void DESCRIPTION Returns the byte count of data transferred Transfers of over 232 bytes about 4GB are not reported correctly RETURN VALUE Size in bytes LIBRARY FTP_CLIENT LIB SEE ALSO ftp_client_setup ftp_data_handler ftp_client_filesize Chapter 5 FTP Client 271 ftp data handler void ftp data handler int dhnd void dhnd data word opts DESCRIPTION Sets a data handler for further FTP data transfer s This handler is only used if the buffer parameter to ftp client setup is passed as NULL The handler is a function which must be coded according to the following prototype int my_handler char data int len longword offset int flags void dhnd_ data This function is called with data pointing to a data buffer and 1en containing the length of that buffer of f set is the byte number relative to the first byte of the entire FTP stream This is useful for data handler functions that do not wish to keep track of the current state of the data source dhnd_ data is the pointer that was passed to ftp data_handler flags contains an indicator of the current operation e FTPDH_IN data is to be stored on this host obtained from an FTP download e FTPDH_OUT data is to be filled with the next data to upload to the FTP server e FTPDH_ END data and len are irrelevan
323. turn value If the parameter is NULL then that information is not retrieved NOTE The data at realm and mimetype should not be altered by the caller The data is read only PARAMETERS sspec spec index realm Pointer to pointer to realm string readgroups Pointer to mask of user groups who have read access writegroups Pointer to mask of user groups who have write access servermask Pointer to servers allowed to access this resource method Pointer to required authentication method mimetype Pointer to pointer to MIME table entry RETURN VALUE 0 Success lt 0 Failure For example an invalid sspec handle SEE ALSO sspec_setpermissions sspec_checkpermissions sspec_access 104 TCP IP User s Manual sspec getpreformfunction void sspec getpreformfunction int form DESCRIPTION Gets the user function that will be called just before HTML form generation This func tion is useful mainly for custom form generation functions PARAMETERS form spec index of the form RETURN VALUE NULL No user function NULL Pointer to user function LIBRARY ZSERVER LIB SEE ALSO sspec_setpreformfunction sspec_setformfunction Chapter 3 Server Utility Library 105 sspec getrealm char sspec getrealm int sspec DESCRIPTION Returns the realm of the spec entry represented by sspec PARAMETERS sspec spec index RETURN VALUE NULL Failure NULL Success pointer to the realm string LIB
324. two functions are required console init int console init void DESCRIPTION This function will initialize Zconsole data structures It must be called before console tick is called for the first time This function also loads the configura tion information from the file system RETURN VALUE 0 Success 1 No configuration information found lt 0 Indicates an error loading the configuration data 1 indicates an error reading the 1st set of information 2 the 2nd set and so on LIBRARY zconsole lib console tick void console tick void DESCRIPTION This function needs to be called periodically in an application program to allow Zconsole time for processing LIBRARY zconsole lib Chapter 11 General Purpose Console 359 11 6 5 Useful Zconsole Function Most of the following functions are only useful for creating custom commands con backup int con_backup void DESCRIPTION This function backs up the current configuration RETURN VALUE 0 Success 1 Failure LIBRARY zconsole lib SEE ALSO con_backup_reserve con_load_backup con backup bytes long con backup bytes void DESCRIPTION Returns the number of bytes necessary for each backup configuration file Note that enough space for two of these files needs to be reserved This function is most useful when ZCONSOLE LIB is being used with FS2 LIB RETURN VALUE Number of bytes needed for a backup configuration file
325. ually only the server needs to talk directly to TCP IP via a TCP socket Prior to Dynamic C 8 50 it was often neces sary for the application s CGI functions to call TCP IP functions This is no longer recommended Instead there are functions in the HTTP server that should be called to mediate all networking calls Chapter 2 Web Enabling Your Application 9 2 3 4 Zserver Block Directly under the HTTP server block is the Zserver or resource manager block This is the cen tral telephone exchange of the entire application It controls access to many of the other blocks in the diagram In spite of its importance and central placing you do not usually need to be aware of its inner workings Zserver has applicability to other types of servers such as FTP because it pro vides a consistent interface to the various different types of resource As indicated in the diagram Zserver is architected as a resource manager and a virtual filesystem The virtual filesystem is basically a notational convenience for accessing all resources using a uniform naming scheme The external appearance of the virtual filesystem is modelled on the Unix approach In Unix all storage devices and the filesystems contained therein are accessed from a single starting point known as the root directory written as a single slash character Under the root directory may be any number of files and directories Some of these directories may actually refer to a comp
326. ubsubstate retval if state gt subsubstate gt state gt content length state gt buffer int state gt content length 0 for i 0 i lt sizeof FORMSpec sizeof FORMType i http scanpost FORMSpec i name state gt buffer FORMSpec i value MAX FORMSIZE return 1 return 0 Chapter 4 HTTP Server 173 4 5 3 4 Sample of a CGI Handler This next function is the CGI handler that calls parse post Itis a state machine based han dler that generates the page It calls parse post and references the structure that is now filled with the parsed data we wanted This function is from Samples tcpip http post c int submit HttpState state auto int i if state gt length buffer to write out if state gt offset lt state gt length state gt offset sock fastwrite amp state gt s state gt buffer int state gt offset int state slength int state soffset else state soffset state gt length 0 0 else switch state gt substate case 0 strepy state gt buffer HTTP 1 0 200 OK r n r n state gt length strlen state gt buffer state soffset 0 state gt substate break case 1 strcpy state gt buffer lt html gt lt head gt lt title gt Results lt title gt lt head gt lt body gt r n state gt length strlen state gt buffer state gt substate break case 2 initialize the FORMSpec dat
327. uch as servers HTTP FTP etc and filesystems FS2 FAT For an overview please see Chapter 2 Web Enabling Your Application The resource manager Zserver lib contains the structures functions and constants to allow HTTP Hypertext Transfer Protocol and FTP File Transfer Protocol servers to share data and user authentication information while running concurrently In general you do not need to know some of the details of Zserver described in this chapter if you are using the server libraries provided with Dynamic C Such sections are marked as advanced and you may skip them unless you are writing a server or filesystem Some sections are marked historical They are included to describe how previous versions of the library worked These may be skipped for new code The basic facility provided by Zserver is the ability to translate resource names URLs in the case of HTTP into references to filesystem and memory objects The term resource refers to the objects files functions and variables that are manipulated by the Zserver library on behalf of the server A file resource refers specifically to a resource of type file as opposed to the actual file that is manipulated by an underlying filesystem which may not be a resource as such Support for HTML forms is also included in Zserver lib Starting with Dynamic C 8 50 an enhanced HTTP server RabbitWeb is available that has an easy to use interface for form genera
328. uld follow the relation 0 lt index lt SSPEC_USERSPERRESOURCE If there is no userid for a given index 1 will be returned If 1 is returned for an index then 1 will also be returned for all higher indices This function may be used to iterate through all users that have read access to a particular resource This only works for RAM and flash table entries Starting with Dynamic C 8 50 access control is done by user groups rather than indi vidual users therefore sspec_getuserid may not work as expected PARAMETERS sspec spec index index index of userid for this sspec resource to return 0 1 2 RETURN VALUE 1 Error or no such userid 0 Success userid is returned LIBRARY ZSERVER LIB SEE ALSO sspec_getusername sauth_getusername Chapter 3 Server Utility Library 109 sspec getusername char sspec getusername int sspec DESCRIPTION Gets the username field of the first user in the user table that has read access to the resource indexed by sspec If multiple users are associated with this resource the first user s username will be returned See sspec_getuserid to get all userids for a resource and sauth_getusername to convert the userids to usernames Starting with Dynamic C 8 50 access control is done by groups rather than individual users therefore sspec_getusername may not work as expected This only works for RAM and flash table entries PARAMETERS sspec spec index R
329. urce manager needs to be able to associ ate other data with each resource This other data is divided into two categories which are listed in the blocks on the left of the diagram The two categories are metadata and authorization Metadata consists of two tables the MIME table and the Rule table The authorization data is currently just a single table of userids The reason for the split into two categories is this the metadata is logically associated with indi vidual resources whereas the authorization data is a mapping from external entities users to the unit in which authorization is performed namely user groups The Rule table has some over lap since it associates groups with individual resource permissions The lowest blocks in the diagram are divided into two groups with a dashed outline The upper group is labelled filesystems and the lower storage Both of these groups are indefinitely extensible meaning that new classes of storage and their organization filesystems may be added in future releases of Dynamic C or by you The arrows between these groups are indicative of the most common patterns of communication others may be defined 10 TCP IP User s Manual 2 4 Architecture of a Toy Application Using the diagram of the previous section as a basis we now focus on writing a simple web enabled application The following diagram is the same as the one above except that the relevant parts
330. valid 56 TCP IP User s Manual sauth setwriteaccess int sauth setwriteaccess int sauth int writeaccess DESCRIPTION Set whether or not a user has write access with the specified server s PARAMETERS sauth Index of the user in the user table writeaccess Server bitmask with bit set to 1 for write access 0 for no write access This is a bitwise OR of the server macros SERVER_HTTP etc that you want the user to have write ac cess to RETURN VALUE 0 Success 1 Failure LIBRARY ZSERVER LIB SEE ALSO Ssauth_getwriteaccess Chapter 3 Server Utility Library 57 sspec access int sspec access char name ServerContext context DESCRIPTION Test access to a given resource by a specified user The userid is set in context gt userid or 1 for testing access by the server in general NOTE sspec_checkpermissions performs a similar function except on a resource handle rather than a resource name PARAMETERS name Resource name as a null terminated string This name is assumed to be relative to context gt cwd if it does not begin with a character Otherwise the name is assumed to be relative to context gt rootdir context Additional context information The ServerContext structure is set up by the caller See sspec_open for documentation on this structure For this function context gt userid should be set to the current user whose access is being tested or may be s
331. ve it in a static variable did you it is used in the sspec_write call http getData returns the available data and http _getDataLength returns its length in bytes The maximum length that http getDataLength will return is HTTP MAXBUFFER which is a macro controlled by the application defaulting to 256 Often the available data length will be less than this even in the middle of a long file Note that the return code from sspec_write is not checked This is a shortcoming that we fix later since the solution can be slightly complex For now we just hope that it works Action Code CGI_END The next thing to consider is closing the file when the upload is complete For this we make use of the CGI_ END action code case CGI END handle http _getCond s COND HANDLE sspec_close handle break This is quite simple We simply retrieve the handle and close it Response to the Client Redirection Finally we have to consider what to do at the end of all parts CGI_EOF or if the connection was cancelled CGI_ABORT You may recall that the CGI has two responsibilities one is to pro cess the incoming data and the other is to write some results back to the client We have already done the former it is only left to do the latter Writing results to the client means we have to generate the proper HTTP response including all the necessary headers and web page content The CGI can do this itself by putting strings in
332. ve problems with e mail being rejected by the server turn on SMITP_DEBUG If it is giving an error message after the HELO line talk to the administer of the machine for the appropriate value to place in SMTP_ DOMAIN If you do not define this macro it will default to MY IP ADDRESS define SMTP DOMAIN somemachine somedomain com SMTP MAX DATALEN Defaults to 256 Maximum buffer size for server responses and short client requests SMTP MAX PASSWORDLEN Defaults to 16 Maximum length of the password used in authentication SMTP MAX USERNAMELEN Defaults to 64 Maximum length of the user name used in authentication SMTP MAX SERVERLEN Defaults to MAX_ STRING which defaults to 50 Maximum length of mail server name SMTP SERVER This macro defines the mail server that will relay the controller s mail This server must be configured to relay mail for your controller You can either place a fully qualified do main name or an IP address in this field define SMTP SERVER mail mydomain com or define SMTP SERVER 10 10 6 19 314 TCP IP User s Manual SMTP TIMEOUT This macro tells the SMTP code how long in seconds to try to send the e mail before tim ing out It defaults to 20 seconds define SMTP TIMEOUT 10 USE _SMTP_AUTH Define this macro to enable SMTP authentication Chapter 8 SMTP Mail Client 315 8 5 API Functions The user callable functions described in this section are found in the Dynamic C l
333. ver that the controller is talking to is mail somehost com The lines that begin with a numeric value are coming from the mail server The other lines were sent by the controller More information on the exact specification of SMTP and the meanings of the commands and responses can be found in RFC821 at http www ietf org 220 mail somehost com ESMTP Service WorldMail 1 3 122 ready HELO 10 10 6 100 250 mail somewhere com MAIL FROM lt me somewhere com gt 250 MAIL FROM lt me somewhere com gt OK RCPT TO lt someone somewhereelse com gt 250 RCPT TO lt someone somewhereelse com gt OK DATA 354 Start mail input end with lt CRLF gt lt CRLF gt From lt me somewhere com gt To lt someone somewhereelse com gt Subject test mail test mail 250 Mail accepted QUIT 221 mail somehost com QUIT You can see a listing of the conversation between your controller and the mail server by defining the SMTP_DEBUG macro at the top of your program Note that there must be a blank line after the line Subject test mail Chapter 8 SMTP Mail Client 311 8 2 SMTP Authentication In most situations Internet access is provided by an Internet Service Provider ISP Usually the ISP runs an email server that will accept emails without authentication from customers that are within their network Users outside of their network are not allowed to send email through their servers because the mail server would quickl
334. ving Static Web Pages 163 http_sock_xfastread 0 0 0 256 Dynamic Web Pages Without HTML http_sock_xfastwrite ee 257 Forms 165 http_status oes eeceeeseceeeees 258 Web Pages With HTML Forms 170 http_switchCGI Ustindivescousedeseeeeesssesees 259 f http_urldecode ceeeeeeesseeeeeees 260 HTML Forms Using Zserver lib 176 http Write oo iriri iseis 261 4 6 HTTP File Upload eee eeeeeeeeeeees 182 shtm _addfunction cc0 eceeeecees 263 What is a CGI Function and Why is It ee ee LEA E R AF Useful 182 shtmi_de unc TOD ois sess csditscesvescots svete How Do I Use the New CGI Facility sini ce Naaable OEE E R 266 183 3 FTP CHENG o sscstarcdacaatuccuvesicsanesestes 267 4 7 API Functions for HTTP Servers 202 5 1 Configuration Macros seeeeeeeeeeeeeeee 267 COI CONUDUE spepersi 202 5 2 API Functions s ssseseseseeeeeeeereeeerreeen 268 cgi_redirectto ssessessessseesesseeseserens 203 ftp_client_setup cceeeeeeeeeeees 268 Cg _SeEndstring csc iontciehenmiecutinsons 204 ftp_client_tick ciene hse eoctsventsets 269 http_abortCGT sess seseeeeeseees 205 ftp_client_filesize cccceccecseeeeeee 270 http_addfile ob EAEE TT TAN 206 ftp_client_xfer wth Ma cit aadd Pacea ton a 271 http_contentencode ss sssssstt1resee 207 ftp_data_handlet csscccsscessssesseee 272 ila ete ee TE Tapene SERER a fip last Code descictean actus 274 p_defaultCGI oe ee eeeees http delfiles beng we
335. ving not yet been saved SEE ALSO ftp _save_ filenames Chapter 6 FTP Server 293 ftp save filenames int ftp save filenames void DESCRIPTION This function is used in conjunction with the FTP_USE_FS2 HANDLERS macro This function saves the data structure i e the server spec list that keeps track of the association of filenames to file locations in the file system The information is saved to the User block at the offset given in FTP_USERBLOCK_ OFFSET RETURN VALUE 0 Success 1 Failure the information could not be saved due to a write error SEE ALSO ftp _load_filenames 294 TCP IP User s Manual ftp set anonymous int ftp set anonymous int uid DESCRIPTION Set the anonymous user ID Resources belonging to this userID may be accessed by any user A typical use of this function would be ftp set anonymous sauth_adduser anonymous SERVER FTP which defines an anonymous login for the FTP server This only applies to the FTP server The username anonymous is recommended since most FTP clients use this for hosts that have no account for the user PARAMETER uid The user ID to use as the anonymous user This should have been defined using sauth_adduser Pass 1 to set no anonymous user RETURN VALUE Same as the uid parameter except 1 if uid is invalid LIBRARY FTP SERVER LIB SEE ALSO sauth_adduser Chapter 6 FTP Server 295 ftp shutdown void ftp
336. ware of the following issues e The library function sets a pointer to the 2nd parameter url The calling routine is responsible for ensuring that the location represented by the pointer remains valid after the call This is because the URL string will not be processed until after the CGI function is finished e Ifthe application has MAX TCP SOCKET BUFFERS and HTTP_MAXSERVERS set to more than one it is possible that the CGI function will be called successively with different server states serving different client requests In these circumstances it is necessary to ensure that the pointer to the url is valid for each of the server states e After the cgi function has called cgi_redirecto and returns 0 the http_handler then causes the server response to be sent to the browser The infor mation is sent as follows 1 HTTP header response containing the redirection information response code 302 2 A human readable redirection html page telling the user that redirection has taken place and to click here to go to the new URL This is for browsers that do not recognize the redirection 302 command in the header This may cause a problem for browsers which do recognize the 302 redirection command Some browsers immediately issue a GET request to the new location while still reading in the human readable page If MAX_TCP SOCKET BUFFERS and HITP_MAXSERVERS are set to one the server will not receive the GET request because it is busy sending
337. wn PARAMETERS fd The file descriptor returned when the file was opened RETURN VALUE 20 The size of the file in bytes 1 The length of the file is not known 282 TCP IP User s Manual ftp dflt read int ftp dflt read int fd char buf long offset int len DESCRIPTION Read file identified by fd The file contents at the specified offset should be stored into buf up to a maximum length of len The return value should be the actual number of bytes transferred which may be less than len If the return value is zero this indicates normal end of file If the return value is negative then the transfer is aborted Each suc cessive call to this handler will have an increasing offset If the getfilesize handler re turns a non negative length then the read handler will only be called for data up to that length there is no need for such read handlers to check for EOF since the server will assume that only the specified amount of data is available The return value can also be greater than len This is interpreted as I have not put any thing in buf Call me back when you the server can accept at least Len bytes of da ta This is useful for read handlers that find it inconvenient to retrieve data from arbitrary offsets for example a log reader that can only access whole log records If the returned value is greater than the server can ever offer then the server aborts the data transfer The handler should never ask f
338. work problem or by the user pressing the browser s cancel or stop button Let s examine a simple CGI that handles these five action codes This is the minimum require ment however there are some additional codes that may be used by more advanced CGIs The switch statement ignores action codes that are not listed This is deliberate since any other action codes may be safely ignored int my _CGI HttpState s switch http getAction s case CGI START break case CGI DATA break case CGI END break case CGI_ EOF break case CGI ABORT break return 0 188 TCP IP User s Manual The above code is a skeleton that does nothing In other words all incoming data is sent to the bit bucket It is ready to fill out with more useful actions To avoid repeating the code we just take each case condition and fill in the details Action Code CGI_START When the action code CGI_ START is received all of the part headers have been read so the server knows everything relevant about the data that follows The CGI can access this information using several of the HTTP API functions The most important information is the field name on the form from the lt INPUT NAME fieldname gt element in the HTML form case CGI START if http getField s 0 printf Found a file to upload n break http _getField looks at the first character of the field name to see if it is a slash
339. write oc eeeeeseeeeeeeeee 257 ftp_client_Setup ec eeeeeeeeeeseceeeeeeeeenees 268 http_switchCGI 0 eee eeeeeeeeeeseceeeeeseeenees 259 ftp chent CK npr an 269 http Vite e e a A EEEE 261 ftp ehent fef paiaina 271 Console ftp_data_handler 00 0 ee eesceeeeseeeneeeeeee 272 con backup rneer ana e ext 360 ftp ast code sza E 274 con_backup_bytes eeseeseeeeeeeeeeesresersesees 360 FTP Server con_backup_reserve es seeeeeeeererrseeee 361 FDIM iii e toes a a T Ai 292 con_chk_timeout sesesesesesesererererrrrrrrese 361 ftp_Set_ANONYMOUS ee eeeeeeeeeseeeeneeeeeee 295 CON_load_backuPp 0 0 eee esseceeeeeeeeeeneeeeeee 362 ftp_shutdown 20 0 ee eeeceeeeceeseceeeeeceeeeeneeeeees 296 G N Kho IO moseri ian ar Ese 362 fp Hek r EE a 297 con_set_backup_IX eeeesreeesresreresee 363 HTML Forms con_set_files_IX eeeeeesesesesererererererrere 363 http_finderrbuf ee ee eeeceeeeceeeeeeneeeeees 212 CON_Set_tiIMCOUL eee eeeeeeeeseeeeeeee aeons 364 Http NEXthVEEN seiniin eien 237 con_set_user_idle oo eeeeeeeeseseeeeeeeeeeees 364 http_parsefOrm ces eeeeeseceeeeceseeeeneeeeees 238 CON_Set_USEL_tIMCOUT eesse 365 http_scanpost eeeceeeeeeeceseeceeeeceeeeeeeeeees 240 CONSO E_ANIt ooo eececeeeeeseesesessseseeeeees 359 Sspec addiy sesh shecis aa A TEE aae EEA 63 console tick oo ececececeeeeseeesessssseseeenees 359 sspec findfy eenei a ai 84 Cookie sspec_getformtitle eeseseeeeseeeeeeereersreeeees 90
340. xt The second case is HELP SET This is an overview of the family of SET commands i e com mands that set configuration values For HELP SET the command field should be SET and the cmdfunc field should be NULL SET NULL help set txt This second case illustrates the general case of displaying help for a family of commands The family name can not be the name of a command Chapter 11 General Purpose Console 345 11 4 Zconsole Command Array An array of ConsoleCommand structures must be defined in an application program as a con stant global variable named console commands All commands available at the console those provided in Zconsole 1ib and custom commands must have an entry in this array 11 4 1 Zconsole Commands The following is an example of a list of commands that may be defined in a Zconsole application When the command name i e the string in the command field is received by the console the function pointed to in the cmdfunc field is executed When the console receives the command HELP lt command name gt the text file located at physical address he lptext will be displayed const ConsoleCommand console _commands HELLO WORLD hello world 0 ECHO con_echo help echo txt HELP con_help help help txt NULL help txt SET NULL help set_txt SET PARAM con _set_ param 0 SET IP con_set_ip help _set_txt SET NETMASK con_set_netmask help
341. xt gt userid field If context gt userid is 1 this is set to anon e group is the resource group name Zserver does not support this Unix concept either so this field is set to the realm of the file resource if it has one otherwise it is set to anon e length is set to the current length of the file resource or 0 if not known e date is set to the modification date of the file resource in Mon dd yyyy format name is the name of the file resource in this directory Example dr r r 1 foo admin 0 Jan 1 1980 ftpfiles rw rw rw 1 foo admin 1250 Mar 6 2003 index htm RETURN VALUE EEOF there were no more entries in this directory Any other negative value parameter or I O error Otherwise non negative the return value should be passed back to this function as the item parameter value to retrieve the next entry SEE ALSO sspec_cd Chapter 3 Server Utility Library 81 sspec fatregister int sspec fatregister int partno fat part pt DESCRIPTION This function must be used to register all FAT partitions that will be accessible to Zserver 1ib Partitions are numbered consecutively from 0 and they correspond to mount points A B C etc It is assumed that by the time this function is called the required drives and partitions have been mounted For example call fat_EnumDrive followed by as many fat MountPartition calls as required The fat part pointer returned by fat MountPartit
342. y be another CGI or any other type of resource that could be presented to the client in response to an HTTP GET or POST request The resource must exist in the flash or ram spec table or in a filesystem RETURN VALUE 0 LIBRARY HTTP LIB SEE ALSO http _getAction http _skipCGI http _abortCGI http finishCGI http write Chapter 4 HTTP Server 259 http urldecode char http urldecode char dest const char src int len DESCRIPTION Converts a string with URL escaped tokens such as 20 hex for space into actual values Changes into a space String can be NULL terminated it is also bounded by a specified string length This function is reentrant PARAMETERS dest Buffer where decoded string is stored sre Buffer holding original string not changed len Maximum size of string NULL terminated strings can be shorter RETURN VALUE dest if all conversion was good NULL if some conversion had trouble LIBRARY HTTP LIB SEE ALSO http_contentencode 260 TCP IP User s Manual http write int http write HttpState state char data word length DESCRIPTION Write data back to the client This function either sends all of the given data or none of it If the data cannot be sent for example because the socket transmit buffer is already full then a special return code indicates that the CGI should try again on the next call Often the CGI itself will not need to write anything to the cli
343. y become a gateway for spam With more people on the go with laptops SMTP authentication allows them to send email through a trusted server with out being directly on the network An informative tutorial on SMTP authentication is available at www fehcom de qmail smtpauth html Default behavior prior to Dynamic C 9 21 was for the login to fail if authentication failed With Dynamic C 9 21 the SMTP library will fall back on unauthenticated login if authentication fails To restore the old behavior when using Dynamic C 9 21 define the macro SMTP AUTH FAIL IF NO AUTH Three methods of authentication are recognized by the implementation of an SMTP client AUTH PLAIN The client sends AUTH PLAIN lt token gt where lt token gt is the Base64 encoded string username Ousername Opassword that will look something like AUTH PLAIN dGVzdABOZXNOAHRIc3RWYXNz The server responds with a message indicating whether authentication was successful AUTH LOGIN Client sends AUTH LOGIN command server responds with 334 VXNlcm5hbWU6 Base64 encoded Username client responds with its Base64 encoded username server responds with 334 UGFzc3dvcemQ6 client responds with its Base64 encoded password At this point the server should respond with a message indicating whether au thentication was successful This method is only slightly more complex than AUTH PLAIN AUTH CRAM MD5 Client sends AUTH CRAM MDS server responds with 334 lt chall

Dynamic C TCP/IP

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