client/src/tunnel.c

   1 /*
   2  *  tunnel6
   3  *  Copyright (C) 2010  Tomas 'ZeXx86' Jedrzejek (zexx86@zexos.org)
   4  *
   5  *  This program is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19
  20 #ifndef __WIN32__
  21 # include <sys/socket.h>
  22 # include <sys/types.h>
  23 # include <netinet/in.h>
  24 # include <arpa/inet.h>
  25 # include <fcntl.h>
  26 # include <unistd.h>
  27 # include <string.h>
  28 # include <stdlib.h>
  29 # include <netdb.h>
  30 #else
  31 # include <windows.h>
  32 #endif
  33 #include <stdio.h>
  34 #include "ipv6.h"
  35 #include "proto.h"
  36 #include "packet.h"
  37 #include "defaults.h"
  38
  39 #ifndef __WIN32__
  40 static int fd;                          /* File descriptor of the current session */
  41 extern int fd_udp;                      /* Polling socket */
  42 #else
  43 static SOCKET fd;                       /* File descriptor of the current session */
  44 extern SOCKET fd_udp;                   /* Polling socket */
  45 #endif
  46 static struct sockaddr_in sockname;     /* Session information */
  47 static char data[DEFAULT_MTU+1];        /* Receiver data buffer */
  48
  49 /* receive data from tunnel server */
  50 int tunnel_recv ()
  51 {
  52         int ret = recv (fd, data, DEFAULT_MTU, 0);
  53
  54         if (ret < 1) {
  55                 //printf ("ERROR -> recvfrom ()\n");
  56                 return 0;
  57         }
  58
  59         data[ret] = '\0';
  60
  61         return ret;
  62 }
  63
  64 /* check for new data from tunnel server */
  65 int tunnel_poll ()
  66 {
  67         int ret = tunnel_recv ();
  68
  69         if (!ret)
  70                 return 0;
  71
  72         /* parse received data */
  73         return proto_parse (data, ret);
  74 }
  75
  76 /* send data to tunnel server */
  77 int tunnel_send (char *packet, unsigned len)
  78 {
  79         if (send (fd, packet, len, 0) == -1) {
  80                 printf ("ERROR -> send ()\n");
  81                 return -1;
  82         }
  83
  84         return 0;
  85 }
  86
  87 /* try to connect to tunnel server and log in */
  88 int tunnel_init (char *addr, unsigned short port, char *name, char *pwd)
  89 {
  90         struct hostent *host;
  91 #ifdef __WIN32__
  92         /* initialize WinSock
  93            version of WinSock API (should be supported from W. XP) */
  94         WORD wVersionRequested = MAKEWORD (2, 2);
  95         WSADATA wsadata;
  96
  97         if (WSAStartup (wVersionRequested, &wsadata)) {
  98             return -1;
  99         }
 100 #endif
 101         /* create UDP socket */
 102         if ((fd = socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
 103                 printf ("ERROR -> socket ()\n");
 104                 goto err;
 105         }
 106
 107         /* check IPv4 from given addr */
 108         if (!(host = gethostbyname (addr))) {
 109                 printf ("ERROR -> Address '%s' does'nt exist\n", addr);
 110                 goto err;
 111         }
 112
 113         /* setup connection */
 114         sockname.sin_family = AF_INET;
 115         sockname.sin_port = htons (port);
 116         memcpy (&sockname.sin_addr, host->h_addr, host->h_length);
 117
 118         /* connect to tunnel server */
 119         if (connect (fd, (struct sockaddr *) &sockname, sizeof (sockname)) == -1) {
 120                 printf ("ERROR -> Unable to connect to '%s'\n", addr);
 121
 122                 goto err;
 123         }
 124
 125         /* send login request to server */
 126         if (proto_login (data, name, pwd) == -1)
 127                 goto err;
 128
 129         /* save polling socket */
 130         fd_udp = fd;
 131
 132         return 0;
 133
 134 err:    /* error */
 135 #ifdef __WIN32__
 136         WSACleanup();
 137 #endif
 138
 139         return -1;
 140 }