src/http.c

   1 /*
   2  * viking -- GPS Data and Topo Analyzer, Explorer, and Manager
   3  *
   4  * Copyright (C) 2003-2005, Evan Battaglia <gtoevan@gmx.net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  */
  21
  22 #include <stdio.h>
  23 #include <gtk/gtk.h>
  24 #include <string.h>
  25 #include <errno.h>
  26 #include <sys/stat.h>
  27 #include <sys/types.h>
  28
  29
  30 #ifdef WINDOWS
  31
  32 #include <io.h>
  33 #include <winsock.h>
  34 #define access(a,b) _access(a,b)
  35 #define close(a) closesocket(a)
  36
  37 char *dirname ( char * dir )
  38 {
  39   char *tmp = dir + strlen(dir) - 1;
  40   while ( tmp != dir && *tmp != '\\' )
  41     tmp--;
  42   *tmp = '\0';
  43   return dir;
  44 }
  45
  46 #else
  47
  48 #include <unistd.h>
  49 #include <sys/types.h>
  50 #include <sys/socket.h>
  51 #include <netinet/in.h>
  52 #include <netdb.h>
  53
  54 /* dirname */
  55 #include <libgen.h>
  56
  57 #endif
  58
  59 #include "http.h"
  60
  61 int http_connect(const char *hostname, int port)
  62 {
  63   int sock;
  64   struct sockaddr_in server;
  65   struct hostent *host_addr;
  66
  67   /* create a socket of type AF_INET, and SOCK_STREAM (TCP) */
  68   sock = socket(AF_INET, SOCK_STREAM, 0);
  69
  70   /* get an IP from a domain name -- essential */
  71   host_addr = gethostbyname(hostname);
  72   if (host_addr == NULL)
  73     return(-1);
  74
  75   server.sin_family = AF_INET;
  76   /* 110 is the standard POP port. Host TO Network order. */
  77   server.sin_port = htons(port);
  78   /* get the IP address.                                  */
  79   server.sin_addr = *((struct in_addr *) host_addr->h_addr);
  80   /* padding unused in sockaddr_in                        */
  81 #ifndef WINDOWS
  82   bzero(&(server.sin_zero), 8);
  83 #endif
  84
  85   if ((connect(sock, (struct sockaddr *) &server, sizeof(struct sockaddr))) == -1)
  86     return(-2);
  87
  88   return(sock);
  89 }
  90
  91 int http_get_line(int sock, char *buf, int len)
  92 {
  93   static char lilbuf;
  94   int size, count;
  95
  96   count = 1;
  97   size = 1;
  98   lilbuf = 'a';
  99   while (size != 0 && lilbuf != '\n' && count < len)
 100   {
 101     size = recv(sock, &lilbuf, 1, 0);
 102     if (size == 0 && count == 1 )
 103       return 0;
 104
 105     if (size > 0)
 106       *buf++ = lilbuf;
 107     count++;
 108   }
 109   *buf = '\0';
 110
 111   return 1;
 112 }
 113
 114 /* makes directory if neccessary */
 115 int http_download_get_url ( const char *hostname, const char *uri, const char *fn, int already_redirected, int sendhostname )
 116 {
 117   static char input_buffer[1024];
 118   int sock;
 119   int len;
 120   FILE *f, *tmp_f;
 121   /* int hnlen = strlen ( hostname ); */
 122
 123   if ( access ( fn, F_OK ) == 0 )
 124   {
 125     return -3;
 126   } else {
 127     if ( errno == ENOENT)
 128     {
 129       char *tmp = g_strdup ( fn );
 130 #ifdef WINDOWS
 131       mkdir( dirname ( dirname ( tmp ) ) );
 132       g_free ( tmp ); tmp = g_strdup ( fn );
 133       mkdir( dirname ( tmp ) );
 134 #else
 135       mkdir( dirname ( dirname ( tmp ) ), 0777 );
 136       g_free ( tmp ); tmp = g_strdup ( fn );
 137       mkdir( dirname ( tmp ), 0777 );
 138 #endif
 139       g_free ( tmp );
 140     }
 141     if ( ! (f = fopen ( fn, "w+b" )) ) /* immediately open file so other threads won't -- prevents race condition */
 142       return -4;
 143   }
 144 #ifdef WINDOWS
 145   WSADATA usadata;
 146   WSAStartup ( MAKEWORD(2,2), &usadata );
 147 #endif
 148
 149   sock = http_connect ( hostname, 80 );
 150   if (sock < 0)
 151   {
 152     fclose ( f );
 153     remove ( fn );
 154     return -1;
 155   }
 156
 157
 158   if ( sendhostname ) {
 159     send ( sock, "GET http://", 11, 0);
 160     send ( sock, hostname, strlen(hostname), 0 );
 161     send ( sock, uri, strlen ( uri ), 0 );
 162     send ( sock, " HTTP/1.0\r\n\r\n", 13, 0 );
 163   } else {
 164     send ( sock, "GET ", 4, 0 );
 165     send ( sock, uri, strlen ( uri ), 0 );
 166     send ( sock, "\r\n\r\n", 4, 0 );
 167   }
 168
 169   /* next, skip through all headers EXCEPT content length.,
 170      that is, if it begins with "Content-Length: " (strncasecmp),
 171      atoi that line from +16 (+17 ?), read that many bytes directly
 172      into file (IF we can open it, else return error) and we're done.
 173   */
 174
 175   /* "HTTP/1.x 200 OK" check */
 176   if ( recv ( sock, input_buffer, 12, 0 ) < 12 || input_buffer[9] != '2' || input_buffer[10] != '0' || input_buffer[11] != '0' )
 177   {
 178     /* maybe it's a redirect */
 179     if ( ! already_redirected )
 180     do
 181     {
 182       if ( http_get_line ( sock, input_buffer, 1024 ) == 0 )
 183         break;
 184
 185       /* Location: http://abc.def/bla */
 186       if ( strncmp(input_buffer, "Location: ", 10) == 0 && strlen(input_buffer) > 17 )
 187       {
 188         char *uri_start;
 189
 190         int rv;
 191         uri_start = strchr(input_buffer+17,'/');
 192
 193         if ( uri_start )
 194         {
 195           char *newhost = g_strndup ( input_buffer + 17, uri_start - input_buffer - 17 );
 196           char *newuri = strdup ( uri_start );
 197           fclose ( f );
 198           remove ( fn );
 199           close ( sock );
 200
 201           rv = http_download_get_url ( newhost, newuri, fn, 1, sendhostname );
 202
 203           free ( newhost );
 204           free ( newuri );
 205           return rv;
 206         }
 207       }
 208     } while (input_buffer[0] != '\r' );
 209
 210     fclose ( f );
 211     remove ( fn );
 212     return 1;
 213   }
 214
 215   do
 216   {
 217     if ( http_get_line ( sock, input_buffer, 1024 ) == 0 )
 218     {
 219       fclose ( f );
 220       remove ( fn );
 221       close ( sock );
 222       return -2;
 223     }
 224   } while (input_buffer[0] != '\r' );
 225
 226   tmp_f = tmpfile();
 227
 228   do {
 229     len = recv ( sock, input_buffer, 1024, 0 );
 230     if ( len > 0 )
 231       fwrite ( input_buffer, 1, len, tmp_f );
 232   } while ( len > 0 );
 233
 234   rewind(tmp_f);
 235
 236   while ( ! feof(tmp_f) )
 237   {
 238     len = fread ( input_buffer, 1, 1024, tmp_f );
 239     fwrite ( input_buffer, 1, len, f);
 240   }
 241   fclose ( tmp_f );
 242   fclose ( f );
 243
 244   close ( sock );
 245 #ifdef WINDOWS
 246     WSACleanup(); /* they sure make winsock programming easy. */
 247 #endif
 248   return 0;
 249 }
 250
 251 /* success = 0, -1 = couldn't connect, -2 HTTP error, -3 file exists, -4 couldn't write to file... */
 252 /* uri: like "/uri.html?whatever" */
 253 /* only reason for the "wrapper" is so we can do redirects. */
 254 int a_http_download_get_url ( const char *hostname, const char *uri, const char *fn )
 255 {
 256   return http_download_get_url ( hostname, uri, fn, 0, 1 );
 257 }
 258
 259 int a_http_download_get_url_nohostname ( const char *hostname, const char *uri, const char *fn )
 260 {
 261   return http_download_get_url ( hostname, uri, fn, 0, 0 );
 262 }