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 <ctype.h>
  28 #include <string.h>
  29 #include <glib.h>
  30 #include <glib/gstdio.h>
  31 #include <glib/gi18n.h>
  32
  33 #include "download.h"
  34
  35 #include "curl_download.h"
  36
  37 gboolean a_check_html_file(FILE* f)
  38 {
  39   gchar **s;
  40   gchar *bp;
  41   fpos_t pos;
  42   gchar buf[33];
  43   size_t nr;
  44   gchar * html_str[] = {
  45     "<html",
  46     "<!DOCTYPE html",
  47     "<head",
  48     "<title",
  49     NULL
  50   };
  51
  52   memset(buf, 0, sizeof(buf));
  53   fgetpos(f, &pos);
  54   rewind(f);
  55   nr = fread(buf, 1, sizeof(buf) - 1, f);
  56   fsetpos(f, &pos);
  57   for (bp = buf; (bp < (buf + sizeof(buf) - 1)) && (nr > (bp - buf)); bp++) {
  58     if (!(isspace(*bp)))
  59       break;
  60   }
  61   if ((bp >= (buf + sizeof(buf) -1)) || ((bp - buf) >= nr))
  62     return FALSE;
  63   for (s = html_str; *s; s++) {
  64     if (strncasecmp(*s, bp, strlen(*s)) == 0)
  65       return TRUE;
  66   }
  67   return FALSE;
  68 }
  69
  70 gboolean a_check_map_file(FILE* f)
  71 {
  72   return !a_check_html_file(f);
  73 }
  74
  75 static int download( const char *hostname, const char *uri, const char *fn, DownloadOptions *options, gboolean ftp)
  76 {
  77   FILE *f;
  78   int ret;
  79   gchar *tmpfilename;
  80   gboolean failure = FALSE;
  81
  82   /* Check file */
  83   if ( g_file_test ( fn, G_FILE_TEST_EXISTS ) == TRUE )
  84   {
  85     /* File exists: return */
  86     return -3;
  87   } else {
  88     gchar *dir = g_path_get_dirname ( fn );
  89     g_mkdir_with_parents ( dir , 0777 );
  90     g_free ( dir );
  91
  92     /* create placeholder file */
  93     if ( ! (f = g_fopen ( fn, "w+b" )) ) /* immediately open file so other threads won't -- prevents race condition */
  94       return -4;
  95     fclose ( f );
  96     f = NULL;
  97   }
  98
  99   tmpfilename = g_strdup_printf("%s.tmp", fn);
 100   f = g_fopen ( tmpfilename, "w+b" );
 101   if ( ! f ) {
 102     g_free ( tmpfilename );
 103     g_remove ( fn ); /* couldn't create temporary. delete 0-byte file. */
 104     return -4;
 105   }
 106
 107   /* Call the backend function */
 108   ret = curl_download_get_url ( hostname, uri, f, options, ftp );
 109   if (ret == -1 || ret == 1 || ret == -2) {
 110     g_debug("%s: download failed: curl_download_get_url=%d", __FUNCTION__, ret);
 111     failure = TRUE;
 112   }
 113
 114   if (!failure && options != NULL && options->check_file != NULL && ! options->check_file(f)) {
 115     g_debug("%s: file content checking failed", __FUNCTION__);
 116     failure = TRUE;
 117   }
 118
 119   if (failure)
 120   {
 121     g_warning(_("Download error: %s"), fn);
 122     fclose ( f );
 123     f = NULL;
 124     g_remove ( tmpfilename );
 125     g_free ( tmpfilename );
 126     g_remove ( fn ); /* couldn't create temporary. delete 0-byte file. */
 127     return -1;
 128   }
 129
 130   fclose ( f );
 131   f = NULL;
 132   g_rename ( tmpfilename, fn ); /* move completely-downloaded file to permanent location */
 133   g_free ( tmpfilename );
 134   return ret;
 135 }
 136
 137 /* success = 0, -1 = couldn't connect, -2 HTTP error, -3 file exists, -4 couldn't write to file... */
 138 /* uri: like "/uri.html?whatever" */
 139 /* only reason for the "wrapper" is so we can do redirects. */
 140 int a_http_download_get_url ( const char *hostname, const char *uri, const char *fn, DownloadOptions *opt )
 141 {
 142   return download ( hostname, uri, fn, opt, FALSE );
 143 }
 144
 145 int a_ftp_download_get_url ( const char *hostname, const char *uri, const char *fn, DownloadOptions *opt )
 146 {
 147   return download ( hostname, uri, fn, opt, TRUE );
 148 }