src/download.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 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25
  26 #include <stdio.h>
  27 #include <errno.h>
  28 #include <ctype.h>
  29 #include <string.h>
  30 #include <strings.h>
  31 #include <gtk/gtk.h>
  32 #include <sys/stat.h>
  33 #include <sys/types.h>
  34
  35 #include "download.h"
  36
  37 #include "curl_download.h"
  38
  39 #ifdef WINDOWS
  40
  41 #include <io.h>
  42 #define access(a,b) _access(a,b)
  43 #define close(a) closesocket(a)
  44
  45 char *dirname ( char * dir )
  46 {
  47   char *tmp = dir + strlen(dir) - 1;
  48   while ( tmp != dir && *tmp != '\\' )
  49     tmp--;
  50   *tmp = '\0';
  51   return dir;
  52 }
  53
  54 #else
  55
  56 #include <unistd.h>
  57 #include <sys/types.h>
  58
  59 /* dirname */
  60 #include <libgen.h>
  61
  62 #endif
  63
  64 static int check_map_file(FILE* f)
  65 {
  66   char **s;
  67   char *bp;
  68   int res = 0;  /* good */
  69   fpos_t pos;
  70   char buf[33];
  71   size_t nr;
  72   char * html_str[] = {
  73     "<html",
  74     "<!DOCTYPE html",
  75     "<head",
  76     "<title",
  77     NULL
  78   };
  79
  80
  81   bzero(buf, sizeof(buf));
  82   fgetpos(f, &pos);
  83   rewind(f);
  84   nr = fread(buf, 1, sizeof(buf) - 1, f);
  85   fsetpos(f, &pos);
  86   for (bp = buf; (bp < (buf + sizeof(buf) - 1)) && (nr > (bp - buf)); bp++) {
  87     if (!(isspace(*bp)))
  88       break;
  89   }
  90   if ((bp >= (buf + sizeof(buf) -1)) || ((bp - buf) >= nr))
  91     return(res);
  92   for (s = html_str; *s; s++) {
  93     if (strncmp(*s, bp, strlen(*s)) == 0)
  94       return(-1);
  95   }
  96   return(res);
  97 }
  98
  99 static int download( const char *hostname, const char *uri, const char *fn, DownloadOptions *options)
 100 {
 101   FILE *f;
 102   int ret;
 103   char *tmpfilename;
 104
 105   /* Check file */
 106   if ( access ( fn, F_OK ) == 0 )
 107   {
 108     /* File exists: return */
 109     return -3;
 110   } else {
 111     if ( errno == ENOENT)
 112     {
 113       char *tmp = g_strdup ( fn );
 114 #ifdef WINDOWS
 115       mkdir( dirname ( dirname ( tmp ) ) );
 116       g_free ( tmp ); tmp = g_strdup ( fn );
 117       mkdir( dirname ( tmp ) );
 118 #else
 119       mkdir( dirname ( dirname ( tmp ) ), 0777 );
 120       g_free ( tmp ); tmp = g_strdup ( fn );
 121       mkdir( dirname ( tmp ), 0777 );
 122 #endif
 123       g_free ( tmp );
 124     }
 125     /* create placeholder file */
 126     if ( ! (f = fopen ( fn, "w+b" )) ) /* immediately open file so other threads won't -- prevents race condition */
 127       return -4;
 128     fclose ( f );
 129   }
 130
 131   tmpfilename = g_strdup_printf("%s.tmp", fn);
 132   f = fopen ( tmpfilename, "w+b" );
 133   if ( ! f ) {
 134     g_free ( tmpfilename );
 135     remove ( fn ); /* couldn't create temporary. delete 0-byte file. */
 136     return -4;
 137   }
 138
 139   /* Call the backend function */
 140   ret = curl_download_get_url ( hostname, uri, f, options );
 141
 142   if (ret == -1 || ret == 1 || ret == -2 || check_map_file(f))
 143   {
 144     g_warning("Download error: %s\n", fn);
 145     fclose ( f );
 146     remove ( tmpfilename );
 147     g_free ( tmpfilename );
 148     remove ( fn ); /* couldn't create temporary. delete 0-byte file. */
 149     return -1;
 150   }
 151
 152   fclose ( f );
 153   rename ( tmpfilename, fn ); /* move completely-downloaded file to permanent location */
 154   g_free ( tmpfilename );
 155   return ret;
 156 }
 157
 158 /* success = 0, -1 = couldn't connect, -2 HTTP error, -3 file exists, -4 couldn't write to file... */
 159 /* uri: like "/uri.html?whatever" */
 160 /* only reason for the "wrapper" is so we can do redirects. */
 161 int a_http_download_get_url ( const char *hostname, const char *uri, const char *fn, DownloadOptions *opt )
 162 {
 163   return download ( hostname, uri, fn, opt );
 164 }