libcurl_tunnel.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <sys/select.h>
   4 #include <curl/curl.h>
   5
   6 #define _FILE_OFFSET_BITS 64 /* for curl_off_t magic */
   7 #define SIZE 655536
   8
   9 int fd_read(int fd, void *buf, size_t len)
  10 {
  11   int bytes_read;
  12   bytes_read = read(fd,buf,len);
  13   return bytes_read;
  14 }
  15
  16 int fd_write(int fd, void *buf, size_t len)
  17 {
  18   int bytes_written;
  19   bytes_written = write(fd,buf,len);
  20   return bytes_written;
  21 }
  22
  23 int fdcopy(int fdin, int fdout)
  24 {
  25   char buf[SIZE];
  26   int n;
  27
  28   if((n=fd_read(fdin,buf,SIZE))<0)
  29   {
  30     fprintf(stderr,"Read Error\n");
  31     exit(1);
  32   }
  33
  34   if(n==0)
  35     return 1;
  36
  37   if(fd_write(fdout,buf,n)!=n)
  38   {
  39     fprintf(stderr,"Write Error\n");
  40     exit(1);
  41   }
  42
  43   return 0;
  44 }
  45
  46 void wait_and_act(int sockfd)
  47 {
  48   struct timeval timeout;
  49   int rc; /* select() return code */
  50   long timeout_ms = 1000;
  51
  52   fd_set fdread;
  53   fd_set fdwrite;
  54   fd_set fdexcep;
  55   int maxfd=sockfd;
  56
  57   while(1==1)
  58   {
  59     FD_ZERO(&fdread);
  60     FD_ZERO(&fdwrite);
  61     FD_ZERO(&fdexcep);
  62
  63     /* set timeout to wait */
  64     timeout.tv_sec = timeout_ms/1000;
  65     timeout.tv_usec = (timeout_ms%1000)*1000;
  66
  67     FD_SET(fileno(stdin), &fdread);
  68     FD_SET(sockfd, &fdread);
  69     /* FD_SET(sockfd, &fdwrite); */
  70
  71     rc = select(maxfd+1,
  72           (fd_set *)&fdread,
  73           (fd_set *)&fdwrite,
  74           (fd_set *)&fdexcep, &timeout);
  75
  76     if(rc==-1) {
  77       /* select error */
  78       fprintf(stderr,"select() error\n");
  79       break;
  80     }
  81     if(rc==0){
  82       /* timeout! */
  83       /* fprintf(stderr,"Timeout\n"); */
  84     }
  85     /* use FD_ISSET() to check what happened, then read/write accordingly */
  86     if (FD_ISSET(fileno(stdin), &fdread))
  87     {
  88       if(fdcopy(fileno(stdin),sockfd))
  89         break;
  90     }
  91     if (FD_ISSET(sockfd,&fdread))
  92     {
  93       if(fdcopy(sockfd,fileno(stdout)))
  94         break;
  95     }
  96   }
  97 }
  98
  99 int main(int argc, char *argv[])
 100 {
 101   CURLcode ret;
 102   long sckt;
 103   CURL *hnd = curl_easy_init();
 104
 105   /* Hard coded for convenience currently. Obviously we'll change this to
 106      read from the command line at some point */
 107   curl_easy_setopt(hnd, CURLOPT_URL, "http://godeater.dyndns.org:443/");
 108   curl_easy_setopt(hnd, CURLOPT_PROXY, "10.1.23.219:8080");
 109   curl_easy_setopt(hnd, CURLOPT_PROXYUSERPWD, "gbchlb:X344ekl25");
 110   curl_easy_setopt(hnd, CURLOPT_USERAGENT, "curl/7.16.4 (i686-pc-linux-gnu) libcurl/7.16.4 GnuTLS/1.4.4 zlib/1.2.3 c-ares/1.4.0");
 111   curl_easy_setopt(hnd, CURLOPT_HTTPPROXYTUNNEL, 1);
 112   curl_easy_setopt(hnd, CURLOPT_CONNECT_ONLY, 1);
 113   curl_easy_setopt(hnd, CURLOPT_VERBOSE, 1);
 114   ret = curl_easy_perform(hnd);
 115
 116   if(ret == CURLE_OK)
 117   {
 118     /* Extract socket, and select() */
 119     ret = curl_easy_getinfo(hnd, CURLINFO_LASTSOCKET, &sckt);
 120     if((sckt==-1) || ret){
 121       fprintf(stderr,"[ERR] Couldn't get socket");
 122       return(-1);
 123     }
 124   }
 125
 126   wait_and_act((int)sckt);
 127
 128
 129   curl_easy_cleanup(hnd);
 130 }