src/download.c

/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 4; tab-width: 4 -*- */
/*
 * viking -- GPS Data and Topo Analyzer, Explorer, and Manager
 *
 * Copyright (C) 2003-2005, Evan Battaglia <gtoevan@gmx.net>
 * Copyright (C) 2007, Guilhem Bonnefille <guilhem.bonnefille@gmail.com>
 * Copyright (C) 2013, Rob Norris <rw_norris@hotmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include <string.h>
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_UTIME_H
#include <utime.h>
#endif
#include <glib.h>
#include <glib/gstdio.h>
#include <glib/gi18n.h>

#include "file_magic.h"
#include "compression.h"
#include "download.h"

#include "curl_download.h"
#include "preferences.h"
#include "globals.h"
#include "vik_compat.h"

static gboolean check_file_first_line(FILE* f, gchar *patterns[])
{
  gchar **s;
  gchar *bp;
  fpos_t pos;
  gchar buf[33];
  size_t nr;

  memset(buf, 0, sizeof(buf));
  if ( !fgetpos(f, &pos) )
    return FALSE;
  rewind(f);
  nr = fread(buf, 1, sizeof(buf) - 1, f);
  if ( !fgetpos(f, &pos) )
    return FALSE;
  for (bp = buf; (bp < (buf + sizeof(buf) - 1)) && (nr > (bp - buf)); bp++) {
    if (!(isspace(*bp)))
      break;
  }
  if ((bp >= (buf + sizeof(buf) -1)) || ((bp - buf) >= nr))
    return FALSE;
  for (s = patterns; *s; s++) {
    if (strncasecmp(*s, bp, strlen(*s)) == 0)
      return TRUE;
  }
  return FALSE;
}

gboolean a_check_html_file(FILE* f)
{
  gchar * html_str[] = {
    "<html",
    "<!DOCTYPE html",
    "<head",
    "<title",
    NULL
  };

  return check_file_first_line(f, html_str);
}

gboolean a_check_map_file(FILE* f)
{
  /* FIXME no more true since a_check_kml_file */
  return !a_check_html_file(f);
}

gboolean a_check_kml_file(FILE* f)
{
  gchar * kml_str[] = {
    "<?xml",
    NULL
  };

  return check_file_first_line(f, kml_str);
}

static GList *file_list = NULL;
static GMutex *file_list_mutex = NULL;

/* spin button scales */
static VikLayerParamScale params_scales[] = {
  {1, 365, 1, 0},		/* download_tile_age */
};

static VikLayerParamData convert_to_display ( VikLayerParamData value )
{
  // From seconds into days
  return VIK_LPD_UINT ( value.u / 86400 );
}

static VikLayerParamData convert_to_internal ( VikLayerParamData value )
{
  // From days into seconds
  return VIK_LPD_UINT ( 86400 * value.u );
}

static VikLayerParam prefs[] = {
  { VIK_LAYER_NUM_TYPES, VIKING_PREFERENCES_NAMESPACE "download_tile_age", VIK_LAYER_PARAM_UINT, VIK_LAYER_GROUP_NONE, N_("Tile age (days):"), VIK_LAYER_WIDGET_SPINBUTTON, &params_scales[0], NULL, NULL, NULL, convert_to_display, convert_to_internal },
};

void a_download_init (void)
{
	VikLayerParamData tmp;
	tmp.u = VIK_CONFIG_DEFAULT_TILE_AGE / 86400; // Now in days
	a_preferences_register(prefs, tmp, VIKING_PREFERENCES_GROUP_KEY);
	file_list_mutex = vik_mutex_new();
}

void a_download_uninit (void)
{
	vik_mutex_free(file_list_mutex);
}

static gboolean lock_file(const char *fn)
{
	gboolean locked = FALSE;
	g_mutex_lock(file_list_mutex);
	if (g_list_find_custom(file_list, fn, (GCompareFunc)g_strcmp0) == NULL)
	{
		// The filename is not yet locked
		file_list = g_list_append(file_list, (gpointer)fn),
		locked = TRUE;
	}
	g_mutex_unlock(file_list_mutex);
	return locked;
}

static void unlock_file(const char *fn)
{
	g_mutex_lock(file_list_mutex);
	file_list = g_list_remove(file_list, (gconstpointer)fn);
	g_mutex_unlock(file_list_mutex);
}

/**
 * Unzip a file - replacing the file with the unzipped contents of the self
 */
static void uncompress_zip ( gchar *name )
{
	GError *error = NULL;
	GMappedFile *mf;

	if ((mf = g_mapped_file_new ( name, FALSE, &error )) == NULL) {
		g_critical(_("Couldn't map file %s: %s"), name, error->message);
		g_error_free(error);
		return;
	}
	gchar *file_contents = g_mapped_file_get_contents ( mf );

	void *unzip_mem = NULL;
	gulong ucsize;

	if ((unzip_mem = unzip_file (file_contents, &ucsize)) == NULL) {
		g_mapped_file_unref ( mf );
		return;
	}

	// This overwrites any previous file contents
	if ( ! g_file_set_contents ( name, unzip_mem, ucsize, &error ) ) {
		g_critical ( "Couldn't write file '%s', because of %s", name, error->message );
		g_error_free ( error );
	}
}

/**
 * a_try_decompress_file:
 * @name:  The potentially compressed filename
 *
 * Perform magic to decide how which type of decompression to attempt
 */
void a_try_decompress_file (gchar *name)
{
	if ( file_magic_check (name, "application/zip", ".zip") ) {
		uncompress_zip ( name );
	}
	else if ( file_magic_check (name, "application/x-bzip2", ".bz2") ) {
		gchar* bz2_name = uncompress_bzip2 ( name );
		if ( bz2_name ) {
			if ( g_remove ( name ) )
				g_critical ("%s: remove file failed [%s]", __FUNCTION__, name );
			if ( g_rename (bz2_name, name) )
				g_critical ("%s: file rename failed [%s] to [%s]", __FUNCTION__, bz2_name, name );
		}
	}
}

#define VIKING_ETAG_XATTR "xattr::viking.etag"

static gboolean get_etag_xattr(const char *fn, CurlDownloadOptions *cdo)
{
  gboolean result = FALSE;
  GFileInfo *fileinfo;
  GFile *file;

  file = g_file_new_for_path(fn);
  fileinfo = g_file_query_info(file, VIKING_ETAG_XATTR, G_FILE_QUERY_INFO_NONE, NULL, NULL);
  if (fileinfo) {
    const char *etag = g_file_info_get_attribute_string(fileinfo, VIKING_ETAG_XATTR);
    if (etag) {
      cdo->etag = g_strdup(etag);
      result = !!cdo->etag;
    }
    g_object_unref(fileinfo);
  }
  g_object_unref(file);

  if (result)
    g_debug("%s: Get etag (xattr) from %s: %s", __FUNCTION__, fn, cdo->etag);

  return result;
}

static gboolean get_etag_file(const char *fn, CurlDownloadOptions *cdo)
{
  gboolean result = FALSE;
  gchar *etag_filename;

  etag_filename = g_strdup_printf("%s.etag", fn);
  if (etag_filename) {
    result = g_file_get_contents(etag_filename, &cdo->etag, NULL, NULL);
    g_free(etag_filename);
  }

  if (result)
    g_debug("%s: Get etag (file) from %s: %s", __FUNCTION__, fn, cdo->etag);

  return result;
}

static void get_etag(const char *fn, CurlDownloadOptions *cdo)
{
  /* first try to get etag from xattr, then fall back to plain file  */
  if (!get_etag_xattr(fn, cdo) && !get_etag_file(fn, cdo)) {
    g_debug("%s: Failed to get etag from %s", __FUNCTION__, fn);
    return;
  }

  /* check if etag is short enough */
  if (strlen(cdo->etag) > 100) {
    g_free(cdo->etag);
    cdo->etag = NULL;
  }

  /* TODO: should check that etag is a valid string */
}

static gboolean set_etag_xattr(const char *fn, CurlDownloadOptions *cdo)
{
  gboolean result = FALSE;
  GFile *file;

  file = g_file_new_for_path(fn);
  result = g_file_set_attribute_string(file, VIKING_ETAG_XATTR, cdo->new_etag, G_FILE_QUERY_INFO_NONE, NULL, NULL);
  g_object_unref(file);

  if (result)
    g_debug("%s: Set etag (xattr) on %s: %s", __FUNCTION__, fn, cdo->new_etag);

  return result;
}

static gboolean set_etag_file(const char *fn, CurlDownloadOptions *cdo)
{
  gboolean result = FALSE;
  gchar *etag_filename;

  etag_filename = g_strdup_printf("%s.etag", fn);
  if (etag_filename) {
    result = g_file_set_contents(etag_filename, cdo->new_etag, -1, NULL);
    g_free(etag_filename);
  }

  if (result)
    g_debug("%s: Set etag (file) on %s: %s", __FUNCTION__, fn, cdo->new_etag);

  return result;
}

static void set_etag(const char *fn, const char *fntmp, CurlDownloadOptions *cdo)
{
  /* first try to store etag in extended attribute, then fall back to plain file */
  if (!set_etag_xattr(fntmp, cdo) && !set_etag_file(fn, cdo)) {
    g_debug("%s: Failed to set etag on %s", __FUNCTION__, fn);
  }
}

static DownloadResult_t download( const char *hostname, const char *uri, const char *fn, DownloadFileOptions *options, gboolean ftp, void *handle)
{
  FILE *f;
  gchar *tmpfilename;
  gboolean failure = FALSE;
  CurlDownloadOptions cdo = {0, NULL, NULL};

  /* Check file */
  if ( g_file_test ( fn, G_FILE_TEST_EXISTS ) == TRUE )
  {
    if (options == NULL || (!options->check_file_server_time &&
                            !options->use_etag)) {
      /* Nothing to do as file already exists and we don't want to check server */
      return DOWNLOAD_NOT_REQUIRED;
    }

    time_t tile_age = a_preferences_get(VIKING_PREFERENCES_NAMESPACE "download_tile_age")->u;
    /* Get the modified time of this file */
    GStatBuf buf;
    (void)g_stat ( fn, &buf );
    time_t file_time = buf.st_mtime;
    if ( (time(NULL) - file_time) < tile_age ) {
      /* File cache is too recent, so return */
      return DOWNLOAD_NOT_REQUIRED;
    }

    if (options != NULL && options->check_file_server_time) {
      cdo.time_condition = file_time;
    }
    if (options != NULL && options->use_etag) {
      get_etag(fn, &cdo);
    }

  } else {
    gchar *dir = g_path_get_dirname ( fn );
    if ( g_mkdir_with_parents ( dir , 0777 ) != 0)
      g_warning ("%s: Failed to mkdir %s", __FUNCTION__, dir );
    g_free ( dir );
  }

  // Early test for valid hostname & uri to avoid unnecessary tmp file
  if ( !hostname && !uri ) {
    g_warning ( "%s: Parameter error - neither hostname nor uri defined", __FUNCTION__ );
    return DOWNLOAD_PARAMETERS_ERROR;
  }

  tmpfilename = g_strdup_printf("%s.tmp", fn);
  if (!lock_file ( tmpfilename ) )
  {
    g_debug("%s: Couldn't take lock on temporary file \"%s\"\n", __FUNCTION__, tmpfilename);
    g_free ( tmpfilename );
    if (options->use_etag)
      g_free ( cdo.etag );
    return DOWNLOAD_FILE_WRITE_ERROR;
  }
  f = g_fopen ( tmpfilename, "w+b" );  /* truncate file and open it */
  if ( ! f ) {
    g_warning("Couldn't open temporary file \"%s\": %s", tmpfilename, g_strerror(errno));
    g_free ( tmpfilename );
    if (options->use_etag)
      g_free ( cdo.etag );
    return DOWNLOAD_FILE_WRITE_ERROR;
  }

  /* Call the backend function */
  CURL_download_t ret = curl_download_get_url ( hostname, uri, f, options, ftp, &cdo, handle );

  DownloadResult_t result = DOWNLOAD_SUCCESS;

  if (ret != CURL_DOWNLOAD_NO_ERROR && ret != CURL_DOWNLOAD_NO_NEWER_FILE) {
    g_debug("%s: download failed: curl_download_get_url=%d", __FUNCTION__, ret);
    failure = TRUE;
    result = DOWNLOAD_HTTP_ERROR;
  }

  if (!failure && options != NULL && options->check_file != NULL && ! options->check_file(f)) {
    g_debug("%s: file content checking failed", __FUNCTION__);
    failure = TRUE;
    result = DOWNLOAD_CONTENT_ERROR;
  }

  fclose ( f );
  f = NULL;

  if (failure)
  {
    g_warning(_("Download error: %s"), fn);
    if ( g_remove ( tmpfilename ) != 0 )
      g_warning( ("Failed to remove: %s"), tmpfilename);
    unlock_file ( tmpfilename );
    g_free ( tmpfilename );
    if ( options != NULL && options->use_etag ) {
      g_free ( cdo.etag );
      g_free ( cdo.new_etag );
    }
    return result;
  }

  if (ret == CURL_DOWNLOAD_NO_NEWER_FILE)  {
    (void)g_remove ( tmpfilename );
     // update mtime of local copy
     // Not security critical, thus potential Time of Check Time of Use race condition is not bad
     // coverity[toctou]
     if ( g_utime ( fn, NULL ) != 0 )
       g_warning ( "%s couldn't set time on: %s", __FUNCTION__, fn );
  } else {
    if ( options != NULL && options->convert_file )
      options->convert_file ( tmpfilename );

    if ( options != NULL && options->use_etag ) {
      if ( cdo.new_etag ) {
        /* server returned an etag value */
        set_etag(fn, tmpfilename, &cdo);
      }
    }

     /* move completely-downloaded file to permanent location */
     if ( g_rename ( tmpfilename, fn ) )
        g_warning ("%s: file rename failed [%s] to [%s]", __FUNCTION__, tmpfilename, fn );
  }
  unlock_file ( tmpfilename );
  g_free ( tmpfilename );

  if ( options != NULL && options->use_etag ) {
    g_free ( cdo.etag );
    g_free ( cdo.new_etag );
  }
  return DOWNLOAD_SUCCESS;
}

/**
 * uri: like "/uri.html?whatever"
 * only reason for the "wrapper" is so we can do redirects.
 */
DownloadResult_t a_http_download_get_url ( const char *hostname, const char *uri, const char *fn, DownloadFileOptions *opt, void *handle )
{
  return download ( hostname, uri, fn, opt, FALSE, handle );
}

DownloadResult_t a_ftp_download_get_url ( const char *hostname, const char *uri, const char *fn, DownloadFileOptions *opt, void *handle )
{
  return download ( hostname, uri, fn, opt, TRUE, handle );
}

void * a_download_handle_init ()
{
  return curl_download_handle_init ();
}

void a_download_handle_cleanup ( void *handle )
{
  curl_download_handle_cleanup ( handle );
}

/**
 * a_download_url_to_tmp_file:
 * @uri:         The URI (Uniform Resource Identifier)
 * @options:     Download options (maybe NULL)
 *
 * returns name of the temporary file created - NULL if unsuccessful
 *  this string needs to be freed once used
 *  the file needs to be removed once used
 */
gchar *a_download_uri_to_tmp_file ( const gchar *uri, DownloadFileOptions *options )
{
  FILE *tmp_file;
  int tmp_fd;
  gchar *tmpname;

  if ( (tmp_fd = g_file_open_tmp ("viking-download.XXXXXX", &tmpname, NULL)) == -1 ) {
    g_critical (_("couldn't open temp file"));
    return NULL;
  }

  tmp_file = fdopen(tmp_fd, "r+");
  if ( !tmp_file )
    return NULL;

  if ( curl_download_uri ( uri, tmp_file, options, NULL, NULL ) ) {
    // error
    fclose ( tmp_file );
    (void)g_remove ( tmpname );
    g_free ( tmpname );
    return NULL;
  }
  fclose ( tmp_file );

  return tmpname;
}
Commit	Line	Data
	1	/* -- Mode: C; indent-tabs-mode: t; c-basic-offset: 4; tab-width: 4 -- */
	2	/*
	3	* viking -- GPS Data and Topo Analyzer, Explorer, and Manager
	4	*
	5	* Copyright (C) 2003-2005, Evan Battaglia <gtoevan@gmx.net>
	6	* Copyright (C) 2007, Guilhem Bonnefille <guilhem.bonnefille@gmail.com>
	7	* Copyright (C) 2013, Rob Norris <rw_norris@hotmail.com>
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License as published by
	11	* the Free Software Foundation; either version 2 of the License, or
	12	* (at your option) any later version.
	13	*
	14	* This program is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	* GNU General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU General Public License
	20	* along with this program; if not, write to the Free Software
	21	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	22	*
	23	*/
	24
	25	#ifdef HAVE_CONFIG_H
	26	#include "config.h"
	27	#endif
	28
	29	#include <stdio.h>
	30	#include <ctype.h>
	31	#include <errno.h>
	32	#include <string.h>
	33	#ifdef HAVE_SYS_TYPES_H
	34	#include <sys/types.h>
	35	#endif
	36	#ifdef HAVE_UTIME_H
	37	#include <utime.h>
	38	#endif
	39	#include <glib.h>
	40	#include <glib/gstdio.h>
	41	#include <glib/gi18n.h>
	42
	43	#include "file_magic.h"
	44	#include "compression.h"
	45	#include "download.h"
	46
	47	#include "curl_download.h"
	48	#include "preferences.h"
	49	#include "globals.h"
	50	#include "vik_compat.h"
	51
	52	static gboolean check_file_first_line(FILE* f, gchar *patterns[])
	53	{
	54	gchar **s;
	55	gchar *bp;
	56	fpos_t pos;
	57	gchar buf[33];
	58	size_t nr;
	59
	60	memset(buf, 0, sizeof(buf));
	61	if ( !fgetpos(f, &pos) )
	62	return FALSE;
	63	rewind(f);
	64	nr = fread(buf, 1, sizeof(buf) - 1, f);
	65	if ( !fgetpos(f, &pos) )
	66	return FALSE;
	67	for (bp = buf; (bp < (buf + sizeof(buf) - 1)) && (nr > (bp - buf)); bp++) {
	68	if (!(isspace(*bp)))
	69	break;
	70	}
	71	if ((bp >= (buf + sizeof(buf) -1)) \|\| ((bp - buf) >= nr))
	72	return FALSE;
	73	for (s = patterns; *s; s++) {
	74	if (strncasecmp(s, bp, strlen(s)) == 0)
	75	return TRUE;
	76	}
	77	return FALSE;
	78	}
	79
	80	gboolean a_check_html_file(FILE* f)
	81	{
	82	gchar * html_str[] = {
	83	"<html",
	84	"<!DOCTYPE html",
	85	"<head",
	86	"<title",
	87	NULL
	88	};
	89
	90	return check_file_first_line(f, html_str);
	91	}
	92
	93	gboolean a_check_map_file(FILE* f)
	94	{
	95	/* FIXME no more true since a_check_kml_file */
	96	return !a_check_html_file(f);
	97	}
	98
	99	gboolean a_check_kml_file(FILE* f)
	100	{
	101	gchar * kml_str[] = {
	102	"<?xml",
	103	NULL
	104	};
	105
	106	return check_file_first_line(f, kml_str);
	107	}
	108
	109	static GList *file_list = NULL;
	110	static GMutex *file_list_mutex = NULL;
	111
	112	/* spin button scales */
	113	static VikLayerParamScale params_scales[] = {
	114	{1, 365, 1, 0}, /* download_tile_age */
	115	};
	116
	117	static VikLayerParamData convert_to_display ( VikLayerParamData value )
	118	{
	119	// From seconds into days
	120	return VIK_LPD_UINT ( value.u / 86400 );
	121	}
	122
	123	static VikLayerParamData convert_to_internal ( VikLayerParamData value )
	124	{
	125	// From days into seconds
	126	return VIK_LPD_UINT ( 86400 * value.u );
	127	}
	128
	129	static VikLayerParam prefs[] = {
	130	{ VIK_LAYER_NUM_TYPES, VIKING_PREFERENCES_NAMESPACE "download_tile_age", VIK_LAYER_PARAM_UINT, VIK_LAYER_GROUP_NONE, N_("Tile age (days):"), VIK_LAYER_WIDGET_SPINBUTTON, &params_scales[0], NULL, NULL, NULL, convert_to_display, convert_to_internal },
	131	};
	132
	133	void a_download_init (void)
	134	{
	135	VikLayerParamData tmp;
	136	tmp.u = VIK_CONFIG_DEFAULT_TILE_AGE / 86400; // Now in days
	137	a_preferences_register(prefs, tmp, VIKING_PREFERENCES_GROUP_KEY);
	138	file_list_mutex = vik_mutex_new();
	139	}
	140
	141	void a_download_uninit (void)
	142	{
	143	vik_mutex_free(file_list_mutex);
	144	}
	145
	146	static gboolean lock_file(const char *fn)
	147	{
	148	gboolean locked = FALSE;
	149	g_mutex_lock(file_list_mutex);
	150	if (g_list_find_custom(file_list, fn, (GCompareFunc)g_strcmp0) == NULL)
	151	{
	152	// The filename is not yet locked
	153	file_list = g_list_append(file_list, (gpointer)fn),
	154	locked = TRUE;
	155	}
	156	g_mutex_unlock(file_list_mutex);
	157	return locked;
	158	}
	159
	160	static void unlock_file(const char *fn)
	161	{
	162	g_mutex_lock(file_list_mutex);
	163	file_list = g_list_remove(file_list, (gconstpointer)fn);
	164	g_mutex_unlock(file_list_mutex);
	165	}
	166
	167	/**
	168	* Unzip a file - replacing the file with the unzipped contents of the self
	169	*/
	170	static void uncompress_zip ( gchar *name )
	171	{
	172	GError *error = NULL;
	173	GMappedFile *mf;
	174
	175	if ((mf = g_mapped_file_new ( name, FALSE, &error )) == NULL) {
	176	g_critical(_("Couldn't map file %s: %s"), name, error->message);
	177	g_error_free(error);
	178	return;
	179	}
	180	gchar *file_contents = g_mapped_file_get_contents ( mf );
	181
	182	void *unzip_mem = NULL;
	183	gulong ucsize;
	184
	185	if ((unzip_mem = unzip_file (file_contents, &ucsize)) == NULL) {
	186	g_mapped_file_unref ( mf );
	187	return;
	188	}
	189
	190	// This overwrites any previous file contents
	191	if ( ! g_file_set_contents ( name, unzip_mem, ucsize, &error ) ) {
	192	g_critical ( "Couldn't write file '%s', because of %s", name, error->message );
	193	g_error_free ( error );
	194	}
	195	}
	196
	197	/**
	198	* a_try_decompress_file:
	199	* @name: The potentially compressed filename
	200	*
	201	* Perform magic to decide how which type of decompression to attempt
	202	*/
	203	void a_try_decompress_file (gchar *name)
	204	{
	205	if ( file_magic_check (name, "application/zip", ".zip") ) {
	206	uncompress_zip ( name );
	207	}
	208	else if ( file_magic_check (name, "application/x-bzip2", ".bz2") ) {
	209	gchar* bz2_name = uncompress_bzip2 ( name );
	210	if ( bz2_name ) {
	211	if ( g_remove ( name ) )
	212	g_critical ("%s: remove file failed [%s]", __FUNCTION__, name );
	213	if ( g_rename (bz2_name, name) )
	214	g_critical ("%s: file rename failed [%s] to [%s]", __FUNCTION__, bz2_name, name );
	215	}
	216	}
	217	}
	218
	219	#define VIKING_ETAG_XATTR "xattr::viking.etag"
	220
	221	static gboolean get_etag_xattr(const char fn, CurlDownloadOptions cdo)
	222	{
	223	gboolean result = FALSE;
	224	GFileInfo *fileinfo;
	225	GFile *file;
	226
	227	file = g_file_new_for_path(fn);
	228	fileinfo = g_file_query_info(file, VIKING_ETAG_XATTR, G_FILE_QUERY_INFO_NONE, NULL, NULL);
	229	if (fileinfo) {
	230	const char *etag = g_file_info_get_attribute_string(fileinfo, VIKING_ETAG_XATTR);
	231	if (etag) {
	232	cdo->etag = g_strdup(etag);
	233	result = !!cdo->etag;
	234	}
	235	g_object_unref(fileinfo);
	236	}
	237	g_object_unref(file);
	238
	239	if (result)
	240	g_debug("%s: Get etag (xattr) from %s: %s", __FUNCTION__, fn, cdo->etag);
	241
	242	return result;
	243	}
	244
	245	static gboolean get_etag_file(const char fn, CurlDownloadOptions cdo)
	246	{
	247	gboolean result = FALSE;
	248	gchar *etag_filename;
	249
	250	etag_filename = g_strdup_printf("%s.etag", fn);
	251	if (etag_filename) {
	252	result = g_file_get_contents(etag_filename, &cdo->etag, NULL, NULL);
	253	g_free(etag_filename);
	254	}
	255
	256	if (result)
	257	g_debug("%s: Get etag (file) from %s: %s", __FUNCTION__, fn, cdo->etag);
	258
	259	return result;
	260	}
	261
	262	static void get_etag(const char fn, CurlDownloadOptions cdo)
	263	{
	264	/* first try to get etag from xattr, then fall back to plain file */
	265	if (!get_etag_xattr(fn, cdo) && !get_etag_file(fn, cdo)) {
	266	g_debug("%s: Failed to get etag from %s", __FUNCTION__, fn);
	267	return;
	268	}
	269
	270	/* check if etag is short enough */
	271	if (strlen(cdo->etag) > 100) {
	272	g_free(cdo->etag);
	273	cdo->etag = NULL;
	274	}
	275
	276	/* TODO: should check that etag is a valid string */
	277	}
	278
	279	static gboolean set_etag_xattr(const char fn, CurlDownloadOptions cdo)
	280	{
	281	gboolean result = FALSE;
	282	GFile *file;
	283
	284	file = g_file_new_for_path(fn);
	285	result = g_file_set_attribute_string(file, VIKING_ETAG_XATTR, cdo->new_etag, G_FILE_QUERY_INFO_NONE, NULL, NULL);
	286	g_object_unref(file);
	287
	288	if (result)
	289	g_debug("%s: Set etag (xattr) on %s: %s", __FUNCTION__, fn, cdo->new_etag);
	290
	291	return result;
	292	}
	293
	294	static gboolean set_etag_file(const char fn, CurlDownloadOptions cdo)
	295	{
	296	gboolean result = FALSE;
	297	gchar *etag_filename;
	298
	299	etag_filename = g_strdup_printf("%s.etag", fn);
	300	if (etag_filename) {
	301	result = g_file_set_contents(etag_filename, cdo->new_etag, -1, NULL);
	302	g_free(etag_filename);
	303	}
	304
	305	if (result)
	306	g_debug("%s: Set etag (file) on %s: %s", __FUNCTION__, fn, cdo->new_etag);
	307
	308	return result;
	309	}
	310
	311	static void set_etag(const char fn, const char fntmp, CurlDownloadOptions *cdo)
	312	{
	313	/* first try to store etag in extended attribute, then fall back to plain file */
	314	if (!set_etag_xattr(fntmp, cdo) && !set_etag_file(fn, cdo)) {
	315	g_debug("%s: Failed to set etag on %s", __FUNCTION__, fn);
	316	}
	317	}
	318
	319	static DownloadResult_t download( const char hostname, const char uri, const char fn, DownloadFileOptions options, gboolean ftp, void *handle)
	320	{
	321	FILE *f;
	322	gchar *tmpfilename;
	323	gboolean failure = FALSE;
	324	CurlDownloadOptions cdo = {0, NULL, NULL};
	325
	326	/* Check file */
	327	if ( g_file_test ( fn, G_FILE_TEST_EXISTS ) == TRUE )
	328	{
	329	if (options == NULL \|\| (!options->check_file_server_time &&
	330	!options->use_etag)) {
	331	/* Nothing to do as file already exists and we don't want to check server */
	332	return DOWNLOAD_NOT_REQUIRED;
	333	}
	334
	335	time_t tile_age = a_preferences_get(VIKING_PREFERENCES_NAMESPACE "download_tile_age")->u;
	336	/* Get the modified time of this file */
	337	GStatBuf buf;
	338	(void)g_stat ( fn, &buf );
	339	time_t file_time = buf.st_mtime;
	340	if ( (time(NULL) - file_time) < tile_age ) {
	341	/* File cache is too recent, so return */
	342	return DOWNLOAD_NOT_REQUIRED;
	343	}
	344
	345	if (options != NULL && options->check_file_server_time) {
	346	cdo.time_condition = file_time;
	347	}
	348	if (options != NULL && options->use_etag) {
	349	get_etag(fn, &cdo);
	350	}
	351
	352	} else {
	353	gchar *dir = g_path_get_dirname ( fn );
	354	if ( g_mkdir_with_parents ( dir , 0777 ) != 0)
	355	g_warning ("%s: Failed to mkdir %s", __FUNCTION__, dir );
	356	g_free ( dir );
	357	}
	358
	359	// Early test for valid hostname & uri to avoid unnecessary tmp file
	360	if ( !hostname && !uri ) {
	361	g_warning ( "%s: Parameter error - neither hostname nor uri defined", __FUNCTION__ );
	362	return DOWNLOAD_PARAMETERS_ERROR;
	363	}
	364
	365	tmpfilename = g_strdup_printf("%s.tmp", fn);
	366	if (!lock_file ( tmpfilename ) )
	367	{
	368	g_debug("%s: Couldn't take lock on temporary file \"%s\"\n", __FUNCTION__, tmpfilename);
	369	g_free ( tmpfilename );
	370	if (options->use_etag)
	371	g_free ( cdo.etag );
	372	return DOWNLOAD_FILE_WRITE_ERROR;
	373	}
	374	f = g_fopen ( tmpfilename, "w+b" ); /* truncate file and open it */
	375	if ( ! f ) {
	376	g_warning("Couldn't open temporary file \"%s\": %s", tmpfilename, g_strerror(errno));
	377	g_free ( tmpfilename );
	378	if (options->use_etag)
	379	g_free ( cdo.etag );
	380	return DOWNLOAD_FILE_WRITE_ERROR;
	381	}
	382
	383	/* Call the backend function */
	384	CURL_download_t ret = curl_download_get_url ( hostname, uri, f, options, ftp, &cdo, handle );
	385
	386	DownloadResult_t result = DOWNLOAD_SUCCESS;
	387
	388	if (ret != CURL_DOWNLOAD_NO_ERROR && ret != CURL_DOWNLOAD_NO_NEWER_FILE) {
	389	g_debug("%s: download failed: curl_download_get_url=%d", __FUNCTION__, ret);
	390	failure = TRUE;
	391	result = DOWNLOAD_HTTP_ERROR;
	392	}
	393
	394	if (!failure && options != NULL && options->check_file != NULL && ! options->check_file(f)) {
	395	g_debug("%s: file content checking failed", __FUNCTION__);
	396	failure = TRUE;
	397	result = DOWNLOAD_CONTENT_ERROR;
	398	}
	399
	400	fclose ( f );
	401	f = NULL;
	402
	403	if (failure)
	404	{
	405	g_warning(_("Download error: %s"), fn);
	406	if ( g_remove ( tmpfilename ) != 0 )
	407	g_warning( ("Failed to remove: %s"), tmpfilename);
	408	unlock_file ( tmpfilename );
	409	g_free ( tmpfilename );
	410	if ( options != NULL && options->use_etag ) {
	411	g_free ( cdo.etag );
	412	g_free ( cdo.new_etag );
	413	}
	414	return result;
	415	}
	416
	417	if (ret == CURL_DOWNLOAD_NO_NEWER_FILE) {
	418	(void)g_remove ( tmpfilename );
	419	// update mtime of local copy
	420	// Not security critical, thus potential Time of Check Time of Use race condition is not bad
	421	// coverity[toctou]
	422	if ( g_utime ( fn, NULL ) != 0 )
	423	g_warning ( "%s couldn't set time on: %s", __FUNCTION__, fn );
	424	} else {
	425	if ( options != NULL && options->convert_file )
	426	options->convert_file ( tmpfilename );
	427
	428	if ( options != NULL && options->use_etag ) {
	429	if ( cdo.new_etag ) {
	430	/* server returned an etag value */
	431	set_etag(fn, tmpfilename, &cdo);
	432	}
	433	}
	434
	435	/* move completely-downloaded file to permanent location */
	436	if ( g_rename ( tmpfilename, fn ) )
	437	g_warning ("%s: file rename failed [%s] to [%s]", __FUNCTION__, tmpfilename, fn );
	438	}
	439	unlock_file ( tmpfilename );
	440	g_free ( tmpfilename );
	441
	442	if ( options != NULL && options->use_etag ) {
	443	g_free ( cdo.etag );
	444	g_free ( cdo.new_etag );
	445	}
	446	return DOWNLOAD_SUCCESS;
	447	}
	448
	449	/**
	450	* uri: like "/uri.html?whatever"
	451	* only reason for the "wrapper" is so we can do redirects.
	452	*/
	453	DownloadResult_t a_http_download_get_url ( const char hostname, const char uri, const char fn, DownloadFileOptions opt, void *handle )
	454	{
	455	return download ( hostname, uri, fn, opt, FALSE, handle );
	456	}
	457
	458	DownloadResult_t a_ftp_download_get_url ( const char hostname, const char uri, const char fn, DownloadFileOptions opt, void *handle )
	459	{
	460	return download ( hostname, uri, fn, opt, TRUE, handle );
	461	}
	462
	463	void * a_download_handle_init ()
	464	{
	465	return curl_download_handle_init ();
	466	}
	467
	468	void a_download_handle_cleanup ( void *handle )
	469	{
	470	curl_download_handle_cleanup ( handle );
	471	}
	472
	473	/**
	474	* a_download_url_to_tmp_file:
	475	* @uri: The URI (Uniform Resource Identifier)
	476	* @options: Download options (maybe NULL)
	477	*
	478	* returns name of the temporary file created - NULL if unsuccessful
	479	* this string needs to be freed once used
	480	* the file needs to be removed once used
	481	*/
	482	gchar a_download_uri_to_tmp_file ( const gchar uri, DownloadFileOptions *options )
	483	{
	484	FILE *tmp_file;
	485	int tmp_fd;
	486	gchar *tmpname;
	487
	488	if ( (tmp_fd = g_file_open_tmp ("viking-download.XXXXXX", &tmpname, NULL)) == -1 ) {
	489	g_critical (_("couldn't open temp file"));
	490	return NULL;
	491	}
	492
	493	tmp_file = fdopen(tmp_fd, "r+");
	494	if ( !tmp_file )
	495	return NULL;
	496
	497	if ( curl_download_uri ( uri, tmp_file, options, NULL, NULL ) ) {
	498	// error
	499	fclose ( tmp_file );
	500	(void)g_remove ( tmpname );
	501	g_free ( tmpname );
	502	return NULL;
	503	}
	504	fclose ( tmp_file );
	505
	506	return tmpname;
	507	}