libUDPTCPNetwork/webutils.cc

#include "UDPTCPNetwork.h"

#include <pthread.h>
#include <unistd.h>
#include <time.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <list>


WebRequestBuffer::WebRequestBuffer () {
    buffer_pos_data = -1;
    buffer_size = 0;
    buffer_ptr = NULL;
    buffer_len = 0;
}


WebRequestBuffer::~WebRequestBuffer () {
    if (buffer_ptr) {
        free (buffer_ptr);
        buffer_ptr = NULL;
        buffer_size = 0;
        buffer_len = 0;
        buffer_pos_data = -1;
    }
}


/// @brief add text to buffer
/// @param buffer
/// @param len
/// @return 0 on error, 1 on success
int WebRequestBuffer::AddBuffer (char *buffer, int len) {
    //
    // if needed allocate enought buffer, to the next kB
    if (buffer_ptr == NULL || buffer_size <= buffer_len+len) {
        buffer_size = 1024 * (1 + ((buffer_len + len) / 1024));
        if (buffer_ptr == NULL) buffer_ptr = (char*) malloc (buffer_size);
        else                    buffer_ptr = (char*) realloc (buffer_ptr, buffer_size);
    }

    if (buffer_ptr == NULL || buffer_size < buffer_len+len) {
        fprintf (stderr, "%s:%d could not allocate enought memory. buffer_size:%d buffer_len+len:%d \n",
                 __FILE__, __LINE__, buffer_size, buffer_len + len);
        return 0;
    }

    memcpy (buffer_ptr + buffer_len, buffer, len);
    buffer_len += len;
    buffer_ptr[buffer_len] = 0;

    // debug("buffer:'%s'\n", buffer_ptr);

    return 1;
};


/// @brief copy the current buffer to the destination, resize destination if needed
/// @param dstptr pointer to the destination pointer, in case of a reallocation 
/// @param max    pointer to current allocated size of the pointer
/// @return > 0 - len in bytes of the buffer, = -1 error occured
int WebRequestBuffer::GetBuffer (char **dstptr, int *max) {
    // check: valid pointers
    if (dstptr == NULL || max == NULL) {
        fprintf (stderr, "%s:%d not pointer to buffer or not pointer to a lenght set\n",
                 __FILE__, __LINE__);
        return -1;
    }      

    // check: size and reallocate
    if (*max < buffer_len || *max < 0) {
        char *tb = (char*) realloc (*dstptr, buffer_len);
        *dstptr = tb;
        *max = buffer_size;
    }

    // check: could alloc memory
    if (*dstptr == NULL) {
        fprintf (stderr, "%s:%d no destination pointer set\n",
                 __FILE__, __LINE__);
        return -1;
    }

    memcpy (*dstptr, buffer_ptr, buffer_len);
    return buffer_len;
};


/// @brief Check if the Request is Complete. In this case the request_type and the request can
/// @brief be read with GetRequest and GetType(). For a new request Clear() must be called.
/// @return 0 . not complete, 1 . request complete
bool WebRequestBuffer::RequestComplete() {
    int i = 0;
    int element = 0;         // 0. Parameter 1. Value 2. Value n
    int line = 0;
    WebHeaderLine hl;

    request = "";
    protocol_version = "HTTP/1.0";
    request_type = WEB_REQUEST_UNSUPPORTED;
    buffer_pos_data = -1;

    if (buffer_ptr == NULL) return false;

    hl.Clear();
    for (i = 0, element = 0; i < buffer_len; i++) {
        //
        // check if line is complete
        if (buffer_ptr[i] == '\n') { 
            if (hl.value.length() == 0 && hl.parameter.length() == 0) {
                buffer_pos_data = i+1;      // save position of first data byte
                return true;
            }

            // the first line holds the request type and the location/path.
            if (line == 0) {
                hl.parameter = string_to_upper(hl.parameter);
                if (hl.parameter.compare("GET") == 0) request_type = WEB_REQUEST_GET;
                if (hl.parameter.compare("POST") == 0) request_type = WEB_REQUEST_POST;
                request = string_to_lower(hl.value);
            }

            headerlines.push_back(hl);
            hl.Clear();
            element = 0;
            line++;
            continue;
        }

        // ignore some elements   -> maybe it is not needed
        else if (strchr ("\t ", buffer_ptr[i]) != NULL) {
            element++;
            if (element > 1) hl.value += buffer_ptr[i];
        }

        // ignore last CR
        else if (buffer_ptr[i] != '\r') {
            if (element == 0) hl.parameter += buffer_ptr[i];
            // first line ignore protocol version
            else if (line > 0 || element == 1) hl.value += buffer_ptr[i];
        }
    }

    return false;
}


/// @brief get some information about the complete request
/// @param cmd propably get or set command
/// @param obj object related with this command
/// @param jp some json data
/// @return 
int WebRequestBuffer::GetRequestCmdObj(std::string *cmd, std::string *obj, JSONParse *jp) {
    std::string rq = GetRequest();
    int secslash = 0;

    if (cmd == NULL || obj == NULL || jp == NULL)
        errorexit ("Fatal Error cmd:%p obj:%p jp:%p none of these should be NULL\n",
            cmd, obj, jp);

    secslash = rq.find ('/', 1);
    *cmd = rq.substr(1, secslash-1);
    *obj = rq.substr(secslash+1, std::string::npos);
    if (buffer_pos_data > 0)    (*jp).Set(buffer_ptr+buffer_pos_data);
    else                        (*jp).Clear();

    return 1;
}


std::string WebRequestBuffer::GetRequest() {
    std::string rq = "";
    char lastc = 0;
    char c = 0;

    //
    // filter out /.  .. ./
    for (int i = 0; i < request.length(); i++) {
        c = request[i];
        if (((c >= '0' && c <= '9') || (c >= 'a' && c <= 'z') || 
             (c >= 'A' && c <= 'Z') || c == '/' || c == '.' || c == '-' ) &&
            (!((c == '.' || c == '/' ) && (lastc == '/' || lastc == '.')))) {
                rq += c;
                lastc = c;
        }
    }

    return rq;
}


std::string WebRequestBuffer::GetCookie(std::string name) {
    std::list<WebHeaderLine>::iterator il;
    std::size_t i;

    for (il = headerlines.begin(); il != headerlines.end(); il++) {
        if (string_to_lower(il->parameter).compare("cookie:") == 0) {
            i = il->value.find('=');
            if (i == std::string::npos) continue;
            if (il->value.substr(0, i).compare(name) == 0) 
                return il->value.substr(i+1, std::string::npos);
        }
    }
    return "";
};