net/http.h File Reference

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Detailed Description

HTTP Module for Modtronix TCP/IP Stack.

Author:

Modtronix Engineering

Dependencies:

none

Compiler:

MPLAB C18 v2.10 or higher
HITECH PICC-18 V8.35PL3 or higher

Description

Contains the HTTP Server code.
For a detailed description, see the HTTP Server section of this document - in [Modules] [HTTP Server].

Configuration

The following defines are used to configure this module, and should be placed in the projdefs.h (or similar) file. For details, see Project Configuration. To configure the module, the required defines should be uncommended, and the rest commented out.

 //*********************************************************************
 //--------------------   Configuration --------------------
 //*********************************************************************
 //Define the port used for the HTTP server, default is 80
 #define HTTP_PORT   (80)

 //Comment this line if you do NOT want HTML files to be parsed (replace %xnn tags)
 #define HTTP_PARSE_FILETYPE_HTML

 //Comment this line if you do NOT want JavaScript files to be parsed (replace %xnn tags)
 #define HTTP_PARSE_FILETYPE_JS

#include "net\ip.h"
#include "net\tcp.h"
#include "net\fsee.h"
#include "net\security.h"

Data Structures
struct	_HTTP_INFO
struct	_HTTP_USER
Defines
#define	HTTP_END_OF_VAR   (0xFFFF)
#define	HTTP_MAX_RESOURCE_NAME_LEN   (12)
#define	HTTP_PORT   (80)
#define	HTTP_START_OF_VAR   (0x0000)
Typedefs
typedef _HTTP_INFO	HTTP_INFO
typedef _HTTP_USER	HTTP_USER
typedef enum _SM_HTTP	SM_HTTP
typedef enum _SM_HTTP_GET	SM_HTTP_GET
typedef enum _SM_HTTP_POST	SM_HTTP_POST
Enumerations
enum	_SM_HTTP {   SM_HTTP_IDLE, SM_HTTP_GET_TX_HDR, SM_HTTP_GET_TX_BODY, SM_HTTP_POST_RX_HDR,   SM_HTTP_POST_RX_BODY, SM_HTTP_NOT_FOUND, SM_HTTP_DISCONNECT, SM_HTTP_DISCONNECT_WAIT }
enum	_SM_HTTP_GET {   SM_HTTP_GET_READ, SM_HTTP_GET_VAR_GRP, SM_HTTP_GET_VAR_VALMSB, SM_HTTP_GET_VAR_VALLSB,   SM_HTTP_GET_VAR }
enum	_SM_HTTP_POST { SM_HTTP_POST_IMAGE }
Functions
void	HTTPExecGetCmd (HTTP_INFO *httpInfo, BYTE *rqstRes)
BYTE	HTTPGetParam (TCP_SOCKET s, BYTE *param, BYTE *paramLen)
WORD	HTTPGetVar (HTTP_INFO *httpInfo, BYTE *val)
void	HTTPInit (void)
void	HTTPServer (void)

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Define Documentation

#define HTTP_END_OF_VAR   (0xFFFF)

Examples: ex_httpgetvar.c, and ex_httpgetvar2.c.

#define HTTP_MAX_RESOURCE_NAME_LEN   (12)

Maximum length of a requested resource via HTTP = 8 + 3.

#define HTTP_PORT   (80)

#define HTTP_START_OF_VAR   (0x0000)

Examples: ex_httpgetvar.c.

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Typedef Documentation

typedef struct _HTTP_INFO HTTP_INFO

typedef struct _HTTP_USER HTTP_USER

typedef enum _SM_HTTP SM_HTTP

typedef enum _SM_HTTP_GET SM_HTTP_GET

typedef enum _SM_HTTP_POST SM_HTTP_POST

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Enumeration Type Documentation

enum _SM_HTTP

Enumerator: SM_HTTP_IDLE  SM_HTTP_GET_TX_HDR  SM_HTTP_GET_TX_BODY  SM_HTTP_POST_RX_HDR  SM_HTTP_POST_RX_BODY  SM_HTTP_NOT_FOUND  SM_HTTP_DISCONNECT  SM_HTTP_DISCONNECT_WAIT

enum _SM_HTTP_GET

Enumerator: SM_HTTP_GET_READ  SM_HTTP_GET_VAR_GRP  SM_HTTP_GET_VAR_VALMSB  SM_HTTP_GET_VAR_VALLSB  SM_HTTP_GET_VAR

enum _SM_HTTP_POST

Enumerator: SM_HTTP_POST_IMAGE

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Function Documentation

void HTTPExecGetCmd (  HTTP_INFO *  httpInfo, BYTE *  rqstRes )

This function is a "callback" from HTTPServer task. Whenever a remote node performs interactive GET task on page that was served, HTTPServer calls this functions. Use HTTPGetParam() to get all name-value parameters. Parameters: httpInfo  Socket that is currently receiving this HTTP command rqstRes  Name of the Requested resource - GET command's action. All characters are in uppercase! Examples: ex_httpexecgetcmd.c.

BYTE HTTPGetParam (  TCP_SOCKET  s, BYTE *  param, BYTE *  paramLen )

Writes the name and value string to given param buffer. Both strings are NULL terminated. On return name ane value string can be accessed as follows: Pointer to Name parameter = &param[0] Pointer to Value parameter = &param[paramLen] Pre-Condition: HTTPGetRqstRes() must have already be called. Parameters: s  TCP Socket from which to read the next name-value parameter (if any) param  Will hold name and value strings when returning paramLen  On entry into routine holds lengh of param buffer. Will hold Index of value string on return, or 0 if there were none. Returns: 1 if there are parameters to follow, else 0 Examples: ex_httpexecgetcmd.c.

WORD HTTPGetVar (  HTTP_INFO *  httpInfo, BYTE *  val )

This is a callback function from the HTTPServer() to the main application. This function must be implemented by the user somewhere in the code. Whenever a variable substitution is required (the parsed web pages contains a "\%nxx" tag) on any *.cgi pages, HTTPServer calls this function. This function is responsible for replacing this variable ("\%nxx" tag") with a user defined string. For example, the user might want to replace any "\%a00" tag found on a web page with the value of channel 0 of the analog input. When the "\%a00" is found on a web page, the HTTPServer will call this function, and the user can then return a string representing the value of channel 0 of the analog input. The given HTTP_INFO structure contains a 8-bit variable reference (httpInfo->VarRef), a 8-bit variable group (httpInfo->var.get.tagGroup) and a 16-bit variable value (httpInfo->var.get.tagVal). The variable reference indicates whether this is a first call or not. The variable group and variable value give the group and value of the tag found on the web page. Applications should return one character at a time as a variable value. If there are no more characters, or the requeseted variable is not found, this function must set val to NULL. Since this function only allows one character to be returned at a time as part of the variable value, HTTPServer() calls this function multiple times until the user application indicates that there are no more values left for this variable. On begining, HTTPGetVar() is called with the variable reference (httpInfo->var.get.varRef) = HTTP_START_OF_VAR to indicate that this is a first call. Applications should use this reference to start the variable value extraction and return updated reference. If there are no more values left for this variable the application should send HTTP_END_OF_VAR and set var to NULL. If there are any bytes left to be sent, the application should return a value other than HTTP_START_OF_VAR or HTTP_END_OF_VAR. Pre-Condition: HTTPInit() must already be called. Parameters: httpInfo  HTTP_INFO structure of HTTP connection requesting this Variable. val  Buffer for value storage. Returns: Variable reference as required by application. Examples: ex_httpgetvar.c, and ex_httpgetvar2.c.

void HTTPInit (  void   )

Set all HTTP connections to Listening state. Initialize FSM for each connection. This function is called only one during lifetime of the application. Modifies HTTP FSM and connections are initialized Pre-Condition: TCP must already be initialized.

void HTTPServer (  void   )

Itterate through all connections and let it handle its connection. If a connection is not finished, do not process next connections. This must be done, all connections use some static variables that are common. This function acts as a task (similar to one in RTOS). This function performs its task in co-operative manner. Main application must call this function repeatdly to ensure all open or new connections are served on time. Pre-Condition: HTTPInit() must already be called.

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