Single instance HTTP Server using WiFly Interface.

Dependents:   WiFlyHTTPServerSample MultiThreadingHTTPServer

This is my implementation for a HTTP Server using the WiFly Interface. Please note that this is still under development.

It may still contain several bugs. I have tested it using a 1768 on an application board plus RN-XV board.

Currently there is only a FileSystem implemented. Also it is limited to GET request.

I try to extend it further so it will be more useful.

Btw, it does NOT work with RTOS, which seems not to be the Problem of my library.

Do not Forget to Import the WiFly Interface into your Project when using this library.

Change History:

REV5: - added support for basic RPC GET request functionality.

REV4: - added argument parsing from the request uri. - documentation extended and updated.

HTTPConnection.cpp

Committer:
leihen
Date:
2013-05-26
Revision:
1:6b7472d5e9ee
Parent:
0:7a2421e63e74
Child:
2:8653bbcf7e58

File content as of revision 1:6b7472d5e9ee:

/* HTTPConnection.cpp */

#include "mbed.h"
#include "HTTPConnection.h"

#include <vector>
using std::vector;

using std::string;

#if (0 && !defined(TARGET_LPC11U24))
#define INFO(x, ...) std::printf("[HttpConnection : INFO]"x"\r\n", ##__VA_ARGS__);
#define WARN(x, ...) std::printf("[HttpConnection : WARN]"x"\r\n", ##__VA_ARGS__);
#define ERR(x, ...) std::printf("[HttpConnection : ERR]"x"\r\n", ##__VA_ARGS__);
#else
#define INFO(x, ...)
#define WARN(x, ...)
#define ERR(x, ...)
#endif




HTTPConnection::HTTPConnection()
{
}


HTTPConnection::~HTTPConnection()
{
    close();
}

void HTTPConnection::close()
{
    m_Msg.headers.clear();
}

int HTTPConnection::poll()
{
    static char buffer[256] = {};
    static char echoHeader[256] = {};

    
    int rcvd= 0;
    INFO("[HTTPConnection]Waiting for new data in connection");
    //  Try receiving request line
    rcvd = receiveLine(buffer, 255, 3000); 
    if (rcvd == -1) {
        //  there was an error, probably the connection was closed, so close this connection as well
        INFO("No more data available. Will close this connection now.");
        close();
        return -1;
    }

    //  The Request has not yet been received so try it
    rcvd = parse(buffer);
    if (rcvd == -1) {
        //  Invalid content received, so close the connection
        INFO("Invalid message received, so sending negative response and closing connection !");
        sprintf(echoHeader,"HTTP/1.1 400 NOK\n\rContent-Length: %d\n\rContent-Type: text\n\rConnection: Close\n\r\n\r",strlen(buffer));
        m_Tcp.set_blocking(true, 1500);
        m_Tcp.send(echoHeader,strlen(echoHeader));
        m_Tcp.send(buffer,strlen(buffer));
        close();
        rcvd = -1;
        return -1;
    }
    //  The request has been received, try receive the body
    while(rcvd > 0) {
        rcvd = receiveLine((char*)buffer, 255, 3000); 
        //  First check if we received an empty line. This would indicate the end of the message or message body.
        if (rcvd < 0) {
            //  there was an empty line, so we can start with performing the request
            INFO("Request Header was received completely. Performing request.");
            rcvd = 0;
            break;
        }
        else {
            //  add message body
            if (parseHeader(buffer) == 0) {
            }
            else {
                WARN("Invalid message header received !");
            }
        }
    }             
    if (rcvd == 0) {
//        sprintf(echoHeader,"HTTP/1.1 200 OK\n\rContent-Length: %d\n\rContent-Type: text\n\rConnection: Close\n\r\n\r",strlen(buffer));
//        m_Tcp.set_blocking(true);
//        m_Tcp.send_all(echoHeader,strlen(echoHeader));
//        m_Tcp.send_all(buffer,strlen(buffer));
        
        /// INSERT PRCESSING OF REQUESST HERE
        /// END OF PROCESSING REQUEST
        
        //  Do not close the connection, it may be reused
    }
    INFO("Leaving poll function!");
    return rcvd;
}

int HTTPConnection::receiveLine(char* szLine, int nMaxLen, int nTimeout, char cLineTerm)
{
    if ((szLine == NULL) || (nMaxLen == 0))
        return -1;
    
    m_Tcp.set_blocking(false);
    
    Timer tm;
    int i;
    
    //  Try to receive up to the max number of characters
    for (i = 0 ; i < nMaxLen-1 ; i++) {
        int c;
        c = m_Tcp.receive_all( szLine + i, 1 );
        //  Check that - if no character was currently received - the timeout period is reached.
        if ((c == 0) || (c==-1)) {
            //  no character was read, so check if operation timed out
            if (tm.read_ms() > nTimeout) {
                //  Operation timed out
                INFO("Timeout occured in function 'receiveLine'.");
                return -1;
            }
        }
        
        //  Check if line terminating character was received
        if (szLine[i] == cLineTerm)
            break;
    }
    //  Terminate with \0
    szLine[i] = 0;

    //  Trim for '\r' linefeed at the end
    if( (i >0) && (szLine[i-1] == '\r')) {
        i--;
        szLine[i] = 0;
    }
    INFO("receiveLine : \"%s\".", szLine);
    
    //  return number of characters received in the line or return -2 if an empty line was received
    if ((i == 0) || ((i==1) &&(szLine[0] == '\r')))
    {
        //  empty line received, so return -2
        return -2;
    }
    return i;    
}

int HTTPConnection::parse(const char* buffer)
{
    if ((buffer == NULL) || (strlen(buffer) < 4)) {
        ERR("Buffer content is invalid or too short.");
        return -1;
    }
    
    vector<std::string> args;
    args.clear();
    
    //  decompose string into a list of arguments
    char s = 0; // current starting char
    static char buff[255] = {};
    for (int i = 0 ; i < strlen(buffer)+1 ; i++) {
        if ((buffer[i] == ' ') || (buffer[i] == '\n') || (buffer[i] == 0)) {
            // new arg found
            strncpy(buff, &buffer[s], i-s);
            buff[i-s] = 0;
            INFO("Found argument \"%s\"", buff);
            args.push_back(std::string(buff));
            s = i+1;
        }
    }
        
    if (args.at(0) == "GET") {
        m_Msg.request = HTTP_RT_GET;
        m_Msg.uri = args[1];
        m_Msg.version = args[2];    
    }
    else {
        if (args.at(0) == "POST") {
            m_Msg.request = HTTP_RT_GET;
            m_Msg.uri = args[1];
            m_Msg.version = args[2];    
        }
        else {
            INFO("unhandled message.");
        }
    }
    args.clear();
    
    return 1;
}


int HTTPConnection::parseHeader(const char *buffer)
{
    if ((strlen(buffer) <3) || (buffer == NULL))
        return -1;
        
    //  decompose string into a touple of <field name> : <field value>
    static char fieldname[256] = {};
    static char fieldvalue[256] = {};
    for (int i = 0 ; i < strlen(buffer)+1 ; i++) {
        if (buffer[i] == ':') {
            //  touple found
            strncpy(fieldname, buffer, i);
            fieldname[i] = 0;
            strcpy(fieldvalue, &buffer[i+1]);
    
//            m_Msg.headers[fieldname] = fieldvalue;
            
            INFO("Header name=\"%s\" : value=\"%s\".", fieldname, fieldvalue);            
            return 0;
        }
    }
    
    ERR("Did not recieve a valid header : \"%s\".", buffer);
    return -1;
}