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:
2013-05-28
Revision:
4:d065642c32cc
Parent:
3:d6224049b3bf
Child:
6:fe661fa9d18a

File content as of revision 4:d065642c32cc:

/* HTTPConnection.cpp */

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

#include <vector>
using std::vector;

using std::string;

#if (1 && !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



const struct HTTPRequestConfig {
    const char* request_string;
    HTTPRequestType request_type;
} g_requestConfig[] = {
    { "GET",    HTTP_RT_GET },
    { "POST",   HTTP_RT_POST},
    { "PUT",    HTTP_RT_PUT},
    { "OPTIONS",HTTP_RT_OPTIONS},
    { "HEAD",   HTTP_RT_HEAD},
    { "DELETE", HTTP_RT_DELETE},
    { "TRACE",  HTTP_RT_TRACE},
    { "CONNECT",HTTP_RT_CONNECT}
};


HTTPConnection::HTTPConnection()
{
}


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

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

int HTTPConnection::poll()
{
    static char buffer[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(buffer,"HTTP/1.1 400 NOK\n\rContent-Length: %d\n\rContent-Type: text\n\rConnection: Close\n\r\n\r",0);
        m_Tcp.set_blocking(true, 1500);
        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 !");
            }
        }
    }             
    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(char* buffer)
{
    //  Check if buffer is invalid or its content not long enough.
    if ((buffer == NULL) || (strlen(buffer) < 4)) {
        ERR("Buffer content is invalid or too short.");
        return -1;
    }
    
    std::vector<std::string> args;
    args.clear();
    
    int argno = 0;
    //  decompose string into a list of arguments
    char s = 0; // current starting char
    int nLen = strlen(buffer)+1;
    for (int i = 0 ; i < nLen ; i++) {
        if ((buffer[i] == ' ') || (buffer[i] == '\n') || (buffer[i] == 0)) {
            // new arg found
            buffer[i] = 0;
            if (argno++ == 1) {
                //  its the uri
                // parse the uri args
                parseUriArgs(&buffer[s], m_Msg.args);
            }
            INFO("Found argument \"%s\"", &buffer[s]);
            args.push_back(&buffer[s]);
            s = i+1;
        }
    }
    
    // store the uri and the HTTP version
    m_Msg.uri = args[1];
    m_Msg.version = args[2];    
    
    //  Find matching request type
    for (int i = 0 ; i < sizeof(g_requestConfig)/sizeof(struct HTTPRequestConfig) ; i++) {
        if (args.at(0) == g_requestConfig[i].request_string) {
            m_Msg.request = g_requestConfig[i].request_type;
        }
    }
    args.clear();
    
    return 1;
}


int HTTPConnection::parseHeader(char *buffer)
{
    //  Check if the buffer is invalid or if the content is too short to be meaningful
    if ((strlen(buffer) <3) || (buffer == NULL))
        return -1;
        
    //  decompose string into a touple of <field name> : <field value>
    int value_start = 0;
    int buflen = strlen(buffer)+1;
    for (int i = 0 ; i < buflen ; i++) {
        if (buffer[i] == ':') {
            //  touple found
            buffer[i] = 0;
            value_start = i+1;    
            m_Msg.headers[buffer] = &buffer[value_start];
            
            INFO("Header name=\"%s\" : value=\"%s\".", buffer, &buffer[value_start]);            
            return 0;
        }
    }
    
    ERR("Did not recieve a valid header : \"%s\".", buffer);
    return -1;
}

int HTTPConnection::parseUriArgs(char *buffer, map<string,string>&args)
{
    // Check if the buffer is invalid or if the content is too short to be meaningful
    if ((strlen(buffer) <3) || (buffer == NULL))
        return -1;
        
    int args_start = -1;
    int value_start = -1;
    int buflen = strlen(buffer) +1;
    const char* argname = NULL;
    const char* valuename = NULL;
    for (int i = 0; i < buflen ; i++) {
        if (args_start == -1) {  // args section not yet found
            if (buffer[i] == '?') {  // starts with a question mark, so got it
                buffer[i] = 0;
                args_start = i; //  set the start of the args section
                INFO("Argument section found !");
            }
        }
        else {                  // search arg-value touples
            if (argname == NULL) {    //  arg-name found ?
                if (buffer[i] == '=') {
                    //  yes, separate the arg-name
                    buffer[i] = 0;
                    argname = &buffer[args_start];
                    value_start = i+1;
                    INFO("Argument name %s", argname);
                }
            }
            else { // search for end of value
                if ((buffer[i] == '&') || (buffer[i] == 0) || (buffer[i] == '\r') || (buffer[i] == '\n')) {
                    buffer[i] = 0;
                    valuename = &buffer[value_start];
                    INFO("Argument value %s", valuename);
                    args[argname] = valuename;
                    //  reset all indicators
                    argname = NULL;
                    valuename = NULL;
                }
            }
        }
    }
    
    return 0;
}