1 files changed, 1047 insertions, 0 deletions
diff --git a/plugins/datetime/system-timezone.c b/plugins/datetime/system-timezone.c
new file mode 100644
index 0000000..43add01
--- /dev/null
+++ b/plugins/datetime/system-timezone.c
@@ -0,0 +1,1047 @@
+/* System timezone handling
+ *
+ * Copyright (C) 2008 Novell, Inc.
+ *
+ * Authors: Vincent Untz <[email protected]>
+ * 
+ * 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.
+ * 
+ * Some code is based on previous code in clock-location.c and on code from
+ * tz.c (shipped with version <= 2.22.0). Those files were under the same
+ * license, with those authors and copyrights:
+ * 
+ * clock-location.c:
+ * ================
+ * No header, but most of the work was done (AFAIK) by
+ * Federico Mena Quintero <[email protected]>
+ * Matthias Clasen <[email protected]>
+ *
+ * tz.c:
+ * ====
+ * Copyright (C) 2000-2001 Ximian, Inc.
+ * Copyright (C) 2004 Sun Microsystems, Inc.
+ *
+ * Authors: Hans Petter Jansson <[email protected]>
+ * additional functions by Erwann Chenede <[email protected]>
+ * reworked by Vincent Untz <[email protected]>
+ * 
+ * Largely based on Michael Fulbright's work on Anaconda.
+ */
+
+/* FIXME: it'd be nice to filter out the timezones that we might get when
+ * parsing config files that are not in zone.tab. Note that it's also wrong
+ * in some cases: eg, in tzdata2008b, Asia/Calcutta got renamed to
+ * Asia/Kolkata and the old name is not in zone.tab. */
+
+#include <string.h>
+#include <unistd.h>
+
+#include <glib.h>
+#include <glib/gstdio.h>
+#include <gio/gio.h>
+
+#include "system-timezone.h"
+
+/* Files that we look at and that should be monitored */
+#define CHECK_NB 5
+#define ETC_TIMEZONE "/etc/timezone"
+#define ETC_TIMEZONE_MAJ "/etc/TIMEZONE"
+#define ETC_RC_CONF "/etc/rc.conf"
+#define ETC_SYSCONFIG_CLOCK "/etc/sysconfig/clock"
+#define ETC_CONF_D_CLOCK "/etc/conf.d/clock"
+#define ETC_LOCALTIME "/etc/localtime"
+
+/* The first 4 characters in a timezone file, from tzfile.h */
+#define TZ_MAGIC "TZif"
+
+static char *files_to_check[CHECK_NB] = {
+ ETC_TIMEZONE,
+ ETC_TIMEZONE_MAJ,
+ ETC_SYSCONFIG_CLOCK,
+ ETC_CONF_D_CLOCK,
+ ETC_LOCALTIME
+};
+
+static GObject *systz_singleton = NULL;
+
+G_DEFINE_TYPE (SystemTimezone, system_timezone, G_TYPE_OBJECT)
+
+typedef struct {
+ char *tz;
+ char *env_tz;
+ GFileMonitor *monitors[CHECK_NB];
+} SystemTimezonePrivate;
+
+enum {
+ CHANGED,
+ LAST_SIGNAL
+};
+
+static guint system_timezone_signals[LAST_SIGNAL] = { 0 };
+
+static GObject *system_timezone_constructor (GType type,
+ guint n_construct_properties,
+ GObjectConstructParam *construct_properties);
+static void system_timezone_finalize (GObject *obj);
+
+static void system_timezone_monitor_changed (GFileMonitor *handle,
+ GFile *file,
+ GFile *other_file,
+ GFileMonitorEvent event,
+ gpointer user_data);
+
+#define PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), SYSTEM_TIMEZONE_TYPE, SystemTimezonePrivate))
+
+SystemTimezone *
+system_timezone_new (void)
+{
+ return g_object_new (SYSTEM_TIMEZONE_TYPE, NULL);
+}
+
+const char *
+system_timezone_get (SystemTimezone *systz)
+{
+ SystemTimezonePrivate *priv;
+
+ g_return_val_if_fail (IS_SYSTEM_TIMEZONE (systz), NULL);
+
+ priv = PRIVATE (systz);
+ return priv->tz;
+}
+
+const char *
+system_timezone_get_env (SystemTimezone *systz)
+{
+ SystemTimezonePrivate *priv;
+
+ g_return_val_if_fail (IS_SYSTEM_TIMEZONE (systz), NULL);
+
+ priv = PRIVATE (systz);
+ return priv->env_tz;
+}
+
+static void
+system_timezone_class_init (SystemTimezoneClass *class)
+{
+ GObjectClass *g_obj_class = G_OBJECT_CLASS (class);
+
+ g_obj_class->constructor = system_timezone_constructor;
+ g_obj_class->finalize = system_timezone_finalize;
+
+ system_timezone_signals[CHANGED] =
+ g_signal_new ("changed",
+ G_OBJECT_CLASS_TYPE (g_obj_class),
+ G_SIGNAL_RUN_FIRST,
+ G_STRUCT_OFFSET (SystemTimezoneClass, changed),
+ NULL, NULL,
+ g_cclosure_marshal_VOID__STRING,
+ G_TYPE_NONE, 1, G_TYPE_STRING);
+
+ g_type_class_add_private (class, sizeof (SystemTimezonePrivate));
+}
+
+static void
+system_timezone_init (SystemTimezone *systz)
+{
+ int i;
+ SystemTimezonePrivate *priv = PRIVATE (systz);
+
+ priv->tz = NULL;
+ priv->env_tz = NULL;
+ for (i = 0; i < CHECK_NB; i++) 
+ priv->monitors[i] = NULL;
+}
+
+static GObject *
+system_timezone_constructor (GType type,
+ guint n_construct_properties,
+ GObjectConstructParam *construct_properties)
+{
+ GObject *obj;
+ SystemTimezonePrivate *priv;
+ int i;
+
+ /* This is a singleton, we don't need to have it per-applet */
+ if (systz_singleton)
+ return g_object_ref (systz_singleton);
+
+ obj = G_OBJECT_CLASS (system_timezone_parent_class)->constructor (
+ type,
+ n_construct_properties,
+ construct_properties);
+
+ priv = PRIVATE (obj);
+
+ priv->tz = system_timezone_find ();
+
+ priv->env_tz = g_strdup (g_getenv ("TZ"));
+
+ for (i = 0; i < CHECK_NB; i++) {
+ GFile *file;
+ GFile *parent;
+ GFileType parent_type;
+
+ file = g_file_new_for_path (files_to_check[i]);
+
+ parent = g_file_get_parent (file);
+ parent_type = g_file_query_file_type (parent, G_FILE_QUERY_INFO_NONE, NULL);
+ g_object_unref (parent);
+
+ /* We don't try to monitor the file if the parent directory
+ * doesn't exist: this means we're on a system where this file
+ * is not useful to determine the system timezone.
+ * Since gio does not monitor file in non-existing directories
+ * in a clever way (as of gio 2.22, it just polls every other
+ * seconds to see if the directory now exists), this avoids
+ * unnecessary wakeups. */
+ if (parent_type == G_FILE_TYPE_DIRECTORY)
+ priv->monitors[i] = g_file_monitor_file (file,
+ G_FILE_MONITOR_NONE,
+ NULL, NULL);
+ g_object_unref (file);
+
+ if (priv->monitors[i])
+ g_signal_connect (G_OBJECT (priv->monitors[i]),
+ "changed", 
+ G_CALLBACK (system_timezone_monitor_changed),
+ obj);
+ }
+
+ systz_singleton = obj;
+
+ return systz_singleton;
+}
+
+static void
+system_timezone_finalize (GObject *obj)
+{
+ int i;
+ SystemTimezonePrivate *priv = PRIVATE (obj);
+
+ if (priv->tz) {
+ g_free (priv->tz);
+ priv->tz = NULL;
+ }
+
+ if (priv->env_tz) {
+ g_free (priv->env_tz);
+ priv->env_tz = NULL;
+ }
+
+ for (i = 0; i < CHECK_NB; i++) {
+ if (priv->monitors[i])
+ g_object_unref (priv->monitors[i]);
+ priv->monitors[i] = NULL;
+ }
+
+ G_OBJECT_CLASS (system_timezone_parent_class)->finalize (obj);
+
+ g_assert (obj == systz_singleton);
+
+ systz_singleton = NULL;
+}
+
+static void
+system_timezone_monitor_changed (GFileMonitor *handle,
+ GFile *file,
+ GFile *other_file,
+ GFileMonitorEvent event,
+ gpointer user_data)
+{
+ SystemTimezonePrivate *priv = PRIVATE (user_data);
+ char *new_tz;
+
+ if (event != G_FILE_MONITOR_EVENT_CHANGED &&
+ event != G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT &&
+ event != G_FILE_MONITOR_EVENT_DELETED &&
+ event != G_FILE_MONITOR_EVENT_CREATED)
+ return;
+
+ new_tz = system_timezone_find ();
+
+ g_assert (priv->tz != NULL && new_tz != NULL);
+
+ if (strcmp (priv->tz, new_tz) != 0) {
+ g_free (priv->tz);
+ priv->tz = new_tz;
+
+ g_signal_emit (G_OBJECT (user_data),
+ system_timezone_signals[CHANGED],
+ 0, priv->tz);
+ } else
+ g_free (new_tz);
+}
+
+
+/*
+ * Code to deal with the system timezone on all distros.
+ * There's no dependency on the SystemTimezone GObject here.
+ *
+ * Here's what we know:
+ *
+ * + /etc/localtime contains the binary data of the timezone.
+ * It can be a symlink to the actual data file, a hard link to the data
+ * file, or just a copy. So we can determine the timezone with this
+ * (reading the symlink, comparing inodes, or comparing content).
+ *
+ * + However, most distributions also have the timezone setting
+ * configured somewhere else. This might be better to read it from there.
+ *
+ * Debian/Ubuntu/Gentoo (new): content of /etc/timezone
+ * Fedora/Mandriva: the ZONE key in /etc/sysconfig/clock
+ * openSUSE: the TIMEZONE key in /etc/sysconfig/clock
+ * Solaris/OpenSolaris: the TZ key in /etc/TIMEZONE
+ * Arch Linux: the TIMEZONE key in /etc/rc.conf
+ * Gentoo (old): the ZONE key in /etc/conf.d/clock
+ *
+ * FIXME: reading the system-tools-backends, it seems there's this too:
+ * Solaris: the TZ key in /etc/default/init
+ * /etc/TIMEZONE seems to be a link to /etc/default/init
+ *
+ * First, some functions to handle those system config files.
+ *
+ */
+
+/* This works for Debian and derivatives (including Ubuntu), and new Gentoo */
+static char *
+system_timezone_read_etc_timezone (void)
+{
+ FILE *etc_timezone;
+ GString *reading;
+ int c;
+
+ etc_timezone = g_fopen (ETC_TIMEZONE, "r");
+ if (!etc_timezone)
+ return NULL;
+
+ reading = g_string_new ("");
+
+ c = fgetc (etc_timezone);
+ /* only get the first line, we'll validate the value later */
+ while (c != EOF && !g_ascii_isspace (c)) {
+ reading = g_string_append_c (reading, c);
+ c = fgetc (etc_timezone);
+ }
+
+ fclose (etc_timezone);
+
+ if (reading->str && reading->str[0] != '\0')
+ return g_string_free (reading, FALSE);
+ else
+ g_string_free (reading, TRUE);
+
+ return NULL;
+}
+
+static gboolean
+system_timezone_write_etc_timezone (const char *tz,
+ GError **error)
+{
+ char *content;
+ GError *our_error;
+ gboolean retval;
+
+ if (!g_file_test (ETC_TIMEZONE, G_FILE_TEST_IS_REGULAR))
+ return TRUE;
+
+ content = g_strdup_printf ("%s\n", tz);
+
+ our_error = NULL;
+ retval = g_file_set_contents (ETC_TIMEZONE, content, -1, &our_error);
+ g_free (content);
+
+ if (!retval) {
+ g_set_error (error, SYSTEM_TIMEZONE_ERROR,
+ SYSTEM_TIMEZONE_ERROR_GENERAL,
+ ETC_TIMEZONE" cannot be overwritten: %s",
+ our_error->message);
+ g_error_free (our_error);
+ }
+
+ return retval;
+}
+
+
+/* Read a file that looks like a key-file (but there's no need for groups)
+ * and get the last value for a specific key */
+static char *
+system_timezone_read_key_file (const char *filename,
+ const char *key)
+{
+ GIOChannel *channel;
+ char *key_eq;
+ char *line;
+ char *retval;
+
+ if (!g_file_test (filename, G_FILE_TEST_IS_REGULAR))
+ return NULL;
+
+ channel = g_io_channel_new_file (filename, "r", NULL);
+ if (!channel)
+ return NULL;
+
+ key_eq = g_strdup_printf ("%s=", key);
+ retval = NULL;
+
+ while (g_io_channel_read_line (channel, &line, NULL,
+ NULL, NULL) == G_IO_STATUS_NORMAL) {
+ if (g_str_has_prefix (line, key_eq)) {
+ char *value;
+ int len;
+
+ value = line + strlen (key_eq);
+ g_strstrip (value);
+
+ len = strlen (value);
+
+ if (value[0] == '\"') {
+ if (value[len - 1] == '\"') {
+ if (retval)
+ g_free (retval);
+
+ retval = g_strndup (value + 1,
+ len - 2);
+ }
+ } else {
+ if (retval)
+ g_free (retval);
+
+ retval = g_strdup (line + strlen (key_eq));
+ }
+
+ g_strstrip (retval);
+ }
+
+ g_free (line);
+ }
+
+ g_free (key_eq);
+ g_io_channel_unref (channel);
+
+ return retval;
+}
+
+static gboolean
+system_timezone_write_key_file (const char *filename,
+ const char *key,
+ const char *value,
+ GError **error)
+{
+ GError *our_error;
+ char *content;
+ gsize len;
+ char *key_eq;
+ char **lines;
+ gboolean replaced;
+ gboolean retval;
+ int n;
+ 
+ if (!g_file_test (filename, G_FILE_TEST_IS_REGULAR))
+ return TRUE;
+
+ our_error = NULL;
+
+ if (!g_file_get_contents (filename, &content, &len, &our_error)) {
+ g_set_error (error, SYSTEM_TIMEZONE_ERROR,
+ SYSTEM_TIMEZONE_ERROR_GENERAL,
+ "%s cannot be read: %s",
+ filename, our_error->message);
+ g_error_free (our_error);
+ return FALSE;
+ }
+
+ lines = g_strsplit (content, "\n", 0);
+ g_free (content);
+
+ key_eq = g_strdup_printf ("%s=", key);
+ replaced = FALSE;
+
+ for (n = 0; lines[n] != NULL; n++) {
+ if (g_str_has_prefix (lines[n], key_eq)) {
+ char *old_value;
+ gboolean use_quotes;
+
+ old_value = lines[n] + strlen (key_eq);
+ g_strstrip (old_value);
+ use_quotes = old_value[0] == '\"';
+
+ g_free (lines[n]);
+
+ if (use_quotes)
+ lines[n] = g_strdup_printf ("%s\"%s\"",
+ key_eq, value);
+ else
+ lines[n] = g_strdup_printf ("%s%s",
+ key_eq, value);
+
+ replaced = TRUE;
+ }
+ }
+
+ g_free (key_eq);
+
+ if (!replaced) {
+ g_strfreev (lines);
+ return TRUE;
+ }
+
+ content = g_strjoinv ("\n", lines);
+ g_strfreev (lines);
+
+ retval = g_file_set_contents (filename, content, -1, &our_error);
+ g_free (content);
+
+ if (!retval) {
+ g_set_error (error, SYSTEM_TIMEZONE_ERROR,
+ SYSTEM_TIMEZONE_ERROR_GENERAL,
+ "%s cannot be overwritten: %s",
+ filename, our_error->message);
+ g_error_free (our_error);
+ }
+
+ return retval;
+}
+
+/* This works for Solaris/OpenSolaris */
+static char *
+system_timezone_read_etc_TIMEZONE (void)
+{
+ return system_timezone_read_key_file (ETC_TIMEZONE_MAJ,
+ "TZ");
+}
+
+static gboolean
+system_timezone_write_etc_TIMEZONE (const char *tz,
+ GError **error)
+{
+ return system_timezone_write_key_file (ETC_TIMEZONE_MAJ,
+ "TZ", tz, error);
+}
+
+/* This works for Fedora and Mandriva */
+static char *
+system_timezone_read_etc_sysconfig_clock (void)
+{
+ return system_timezone_read_key_file (ETC_SYSCONFIG_CLOCK,
+ "ZONE");
+}
+
+static gboolean
+system_timezone_write_etc_sysconfig_clock (const char *tz,
+ GError **error)
+{
+ return system_timezone_write_key_file (ETC_SYSCONFIG_CLOCK,
+ "ZONE", tz, error);
+}
+
+/* This works for openSUSE */
+static char *
+system_timezone_read_etc_sysconfig_clock_alt (void)
+{
+ return system_timezone_read_key_file (ETC_SYSCONFIG_CLOCK,
+ "TIMEZONE");
+}
+
+static gboolean
+system_timezone_write_etc_sysconfig_clock_alt (const char *tz,
+ GError **error)
+{
+ return system_timezone_write_key_file (ETC_SYSCONFIG_CLOCK,
+ "TIMEZONE", tz, error);
+}
+
+/* This works for old Gentoo */
+static char *
+system_timezone_read_etc_conf_d_clock (void)
+{
+ return system_timezone_read_key_file (ETC_CONF_D_CLOCK,
+ "TIMEZONE");
+}
+
+static gboolean
+system_timezone_write_etc_conf_d_clock (const char *tz,
+ GError **error)
+{
+ return system_timezone_write_key_file (ETC_CONF_D_CLOCK,
+ "TIMEZONE", tz, error);
+}
+
+/* This works for Arch Linux */
+static char *
+system_timezone_read_etc_rc_conf (void)
+{
+ return system_timezone_read_key_file (ETC_RC_CONF,
+ "TIMEZONE");
+}
+
+static gboolean
+system_timezone_write_etc_rc_conf (const char *tz,
+ GError **error)
+{
+ return system_timezone_write_key_file (ETC_RC_CONF,
+ "TIMEZONE", tz, error);
+}
+
+/*
+ *
+ * First, getting the timezone.
+ *
+ */
+
+static char *
+system_timezone_strip_path_if_valid (const char *filename)
+{
+ int skip;
+
+ if (!filename || !g_str_has_prefix (filename, SYSTEM_ZONEINFODIR"/"))
+ return NULL;
+
+ /* Timezone data files also live under posix/ and right/ for some
+ * reason.
+ * FIXME: make sure accepting those files is valid. I think "posix" is
+ * okay, not sure about "right" */
+ if (g_str_has_prefix (filename, SYSTEM_ZONEINFODIR"/posix/"))
+ skip = strlen (SYSTEM_ZONEINFODIR"/posix/");
+ else if (g_str_has_prefix (filename, SYSTEM_ZONEINFODIR"/right/"))
+ skip = strlen (SYSTEM_ZONEINFODIR"/right/");
+ else
+ skip = strlen (SYSTEM_ZONEINFODIR"/");
+
+ return g_strdup (filename + skip);
+}
+
+/* Read the soft symlink from /etc/localtime */
+static char *
+system_timezone_read_etc_localtime_softlink (void)
+{
+ char *file;
+ char *tz;
+
+ if (!g_file_test (ETC_LOCALTIME, G_FILE_TEST_IS_SYMLINK))
+ return NULL;
+
+ file = g_file_read_link (ETC_LOCALTIME, NULL);
+ tz = system_timezone_strip_path_if_valid (file);
+ g_free (file);
+
+ return tz;
+}
+
+typedef gboolean (*CompareFiles) (struct stat *a_stat,
+ struct stat *b_stat,
+ const char *a_content,
+ gsize a_content_len,
+ const char *b_filename);
+
+static char *
+recursive_compare (struct stat *localtime_stat,
+ const char *localtime_content,
+ gsize localtime_content_len,
+ char *file,
+ CompareFiles compare_func)
+{
+ struct stat file_stat;
+
+ if (g_stat (file, &file_stat) != 0)
+ return NULL;
+
+ if (S_ISREG (file_stat.st_mode)) {
+ if (compare_func (localtime_stat,
+ &file_stat,
+ localtime_content,
+ localtime_content_len,
+ file))
+ return system_timezone_strip_path_if_valid (file);
+ else
+ return NULL;
+ } else if (S_ISDIR (file_stat.st_mode)) {
+ GDir *dir = NULL;
+ char *ret = NULL;
+ const char *subfile = NULL;
+ char *subpath = NULL;
+
+ dir = g_dir_open (file, 0, NULL);
+ if (dir == NULL)
+ return NULL;
+
+ while ((subfile = g_dir_read_name (dir)) != NULL) {
+ subpath = g_build_filename (file, subfile, NULL);
+
+ ret = recursive_compare (localtime_stat,
+ localtime_content,
+ localtime_content_len,
+ subpath,
+ compare_func);
+
+ g_free (subpath);
+
+ if (ret != NULL)
+ break;
+ }
+
+ g_dir_close (dir);
+
+ return ret;
+ }
+
+ return NULL;
+}
+
+
+static gboolean
+files_are_identical_inode (struct stat *a_stat,
+ struct stat *b_stat,
+ const char *a_content,
+ gsize a_content_len,
+ const char *b_filename)
+{
+ return (a_stat->st_ino == b_stat->st_ino);
+}
+
+
+/* Determine if /etc/localtime is a hard link to some file, by looking at
+ * the inodes */
+static char *
+system_timezone_read_etc_localtime_hardlink (void)
+{
+ struct stat stat_localtime;
+
+ if (g_stat (ETC_LOCALTIME, &stat_localtime) != 0)
+ return NULL;
+
+ if (!S_ISREG (stat_localtime.st_mode))
+ return NULL;
+
+ return recursive_compare (&stat_localtime,
+ NULL,
+ 0,
+ SYSTEM_ZONEINFODIR,
+ files_are_identical_inode);
+}
+
+static gboolean
+files_are_identical_content (struct stat *a_stat,
+ struct stat *b_stat,
+ const char *a_content,
+ gsize a_content_len,
+ const char *b_filename)
+{
+ char *b_content = NULL;
+ gsize b_content_len = -1;
+ int cmp;
+
+ if (a_stat->st_size != b_stat->st_size)
+ return FALSE;
+
+ if (!g_file_get_contents (b_filename,
+ &b_content, &b_content_len, NULL))
+ return FALSE;
+
+ if (a_content_len != b_content_len) {
+ g_free (b_content);
+ return FALSE;
+ }
+
+ cmp = memcmp (a_content, b_content, a_content_len);
+ g_free (b_content);
+
+ return (cmp == 0);
+}
+
+/* Determine if /etc/localtime is a copy of a timezone file */
+static char *
+system_timezone_read_etc_localtime_content (void)
+{
+ struct stat stat_localtime;
+ char *localtime_content = NULL;
+ gsize localtime_content_len = -1;
+ char *retval;
+
+ if (g_stat (ETC_LOCALTIME, &stat_localtime) != 0)
+ return NULL;
+
+ if (!S_ISREG (stat_localtime.st_mode))
+ return NULL;
+
+ if (!g_file_get_contents (ETC_LOCALTIME,
+ &localtime_content,
+ &localtime_content_len,
+ NULL))
+ return NULL;
+
+ retval = recursive_compare (&stat_localtime,
+ localtime_content,
+ localtime_content_len,
+ SYSTEM_ZONEINFODIR,
+ files_are_identical_content);
+
+ g_free (localtime_content);
+
+ return retval;
+}
+
+typedef char * (*GetSystemTimezone) (void);
+/* The order of the functions here define the priority of the methods used
+ * to find the timezone. First method has higher priority. */
+static GetSystemTimezone get_system_timezone_methods[] = {
+ /* cheap and "more correct" than data from a config file */
+ system_timezone_read_etc_localtime_softlink,
+ /* reading various config files */
+ system_timezone_read_etc_timezone,
+ system_timezone_read_etc_sysconfig_clock,
+ system_timezone_read_etc_sysconfig_clock_alt,
+ system_timezone_read_etc_TIMEZONE,
+ system_timezone_read_etc_rc_conf,
+ /* reading deprecated config files */
+ system_timezone_read_etc_conf_d_clock,
+ /* reading /etc/timezone directly. Expensive since we have to stat
+ * many files */
+ system_timezone_read_etc_localtime_hardlink,
+ system_timezone_read_etc_localtime_content,
+ NULL
+};
+
+static gboolean
+system_timezone_is_valid (const char *tz)
+{
+ const char *c;
+
+ if (!tz)
+ return FALSE;
+
+ for (c = tz; *c != '\0'; c++) {
+ if (!(g_ascii_isalnum (*c) ||
+ *c == '/' || *c == '-' || *c == '_'))
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+char *
+system_timezone_find (void)
+{
+ char *tz;
+ int i;
+
+ for (i = 0; get_system_timezone_methods[i] != NULL; i++) {
+ tz = get_system_timezone_methods[i] ();
+
+ if (system_timezone_is_valid (tz))
+ return tz;
+
+ g_free (tz);
+ }
+
+ return g_strdup ("UTC");
+}
+
+/*
+ *
+ * Now, setting the timezone.
+ *
+ */
+
+static gboolean
+system_timezone_is_zone_file_valid (const char *zone_file,
+ GError **error)
+{
+ GError *our_error;
+ GIOChannel *channel;
+ GIOStatus status;
+ char buffer[strlen (TZ_MAGIC)];
+ gsize read;
+
+ /* First, check the zone_file is properly rooted */
+ if (!g_str_has_prefix (zone_file, SYSTEM_ZONEINFODIR"/")) {
+ g_set_error (error, SYSTEM_TIMEZONE_ERROR,
+ SYSTEM_TIMEZONE_ERROR_INVALID_TIMEZONE_FILE,
+ "Timezone file needs to be under "SYSTEM_ZONEINFODIR);
+ return FALSE;
+ }
+
+ /* Second, check it's a regular file that exists */
+ if (!g_file_test (zone_file, G_FILE_TEST_IS_REGULAR)) {
+ g_set_error (error, SYSTEM_TIMEZONE_ERROR,
+ SYSTEM_TIMEZONE_ERROR_INVALID_TIMEZONE_FILE,
+ "No such timezone file %s", zone_file);
+ return FALSE;
+ }
+
+ /* Third, check that it's a tzfile (see tzfile(5)). The file has a 4
+ * bytes header which is TZ_MAGIC.
+ *
+ * TODO: is there glibc API for this? */
+ our_error = NULL;
+ channel = g_io_channel_new_file (zone_file, "r", &our_error);
+ if (!our_error)
+ status = g_io_channel_read_chars (channel,
+ buffer, strlen (TZ_MAGIC),
+ &read, &our_error);
+ if (channel)
+ g_io_channel_unref (channel);
+
+ if (our_error) {
+ g_set_error (error, SYSTEM_TIMEZONE_ERROR,
+ SYSTEM_TIMEZONE_ERROR_INVALID_TIMEZONE_FILE,
+ "Timezone file %s cannot be read: %s",
+ zone_file, our_error->message);
+ g_error_free (our_error);
+ return FALSE;
+ }
+
+ if (read != strlen (TZ_MAGIC) || strncmp (buffer, TZ_MAGIC, strlen (TZ_MAGIC)) != 0) {
+ g_set_error (error, SYSTEM_TIMEZONE_ERROR,
+ SYSTEM_TIMEZONE_ERROR_INVALID_TIMEZONE_FILE,
+ "%s is not a timezone file",
+ zone_file);
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+static gboolean
+system_timezone_set_etc_timezone (const char *zone_file,
+ GError **error)
+{
+ GError *our_error;
+ char *content;
+ gsize len;
+
+ if (!system_timezone_is_zone_file_valid (zone_file, error))
+ return FALSE;
+
+ /* If /etc/localtime is a symlink, write a symlink */
+ if (g_file_test (ETC_LOCALTIME, G_FILE_TEST_IS_SYMLINK)) {
+ if (g_unlink (ETC_LOCALTIME) == 0 &&
+ symlink (zone_file, ETC_LOCALTIME) == 0)
+ return TRUE;
+
+ /* If we couldn't symlink the file, we'll just fallback on
+ * copying it */
+ }
+
+ /* Else copy the file to /etc/localtime. We explicitly avoid doing
+ * hard links since they break with different partitions */
+ our_error = NULL;
+ if (!g_file_get_contents (zone_file, &content, &len, &our_error)) {
+ g_set_error (error, SYSTEM_TIMEZONE_ERROR,
+ SYSTEM_TIMEZONE_ERROR_GENERAL,
+ "Timezone file %s cannot be read: %s",
+ zone_file, our_error->message);
+ g_error_free (our_error);
+ return FALSE;
+ }
+
+ if (!g_file_set_contents (ETC_LOCALTIME, content, len, &our_error)) {
+ g_set_error (error, SYSTEM_TIMEZONE_ERROR,
+ SYSTEM_TIMEZONE_ERROR_GENERAL,
+ ETC_LOCALTIME" cannot be overwritten: %s",
+ our_error->message);
+ g_error_free (our_error);
+ g_free (content);
+ return FALSE;
+ }
+
+ g_free (content);
+
+ return TRUE;
+}
+
+typedef gboolean (*SetSystemTimezone) (const char *tz,
+ GError **error);
+/* The order here does not matter too much: we'll try to change all files
+ * that already have a timezone configured. It matters in case of error,
+ * since the process will be stopped and the last methods won't be called.
+ * So we use the same order as in get_system_timezone_methods */
+static SetSystemTimezone set_system_timezone_methods[] = {
+ /* writing various config files if they exist and have the
+ * setting already present */
+ system_timezone_write_etc_timezone,
+ system_timezone_write_etc_sysconfig_clock,
+ system_timezone_write_etc_sysconfig_clock_alt,
+ system_timezone_write_etc_TIMEZONE,
+ system_timezone_write_etc_rc_conf,
+ /* writing deprecated config files if they exist and have the
+ * setting already present */
+ system_timezone_write_etc_conf_d_clock,
+ NULL
+};
+
+static gboolean
+system_timezone_update_config (const char *tz,
+ GError **error)
+{
+ int i;
+
+ for (i = 0; set_system_timezone_methods[i] != NULL; i++) {
+ if (!set_system_timezone_methods[i] (tz, error))
+ return FALSE;
+ /* FIXME: maybe continue to change all config files if
+ * possible? */
+ }
+
+ return TRUE;
+}
+
+gboolean
+system_timezone_set_from_file (const char *zone_file,
+ GError **error)
+{
+ const char *tz;
+
+ g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
+
+ tz = zone_file + strlen (SYSTEM_ZONEINFODIR"/");
+
+ /* FIXME: is it right to return FALSE even when /etc/localtime was
+ * changed but not the config files? */
+ return (system_timezone_set_etc_timezone (zone_file, error) &&
+ system_timezone_update_config (tz, error));
+}
+
+gboolean
+system_timezone_set (const char *tz,
+ GError **error)
+{
+ char *zone_file;
+ gboolean retval;
+
+ g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
+
+ zone_file = g_build_filename (SYSTEM_ZONEINFODIR, tz, NULL);
+
+ /* FIXME: is it right to return FALSE even when /etc/localtime was
+ * changed but not the config files? */
+ retval = system_timezone_set_etc_timezone (zone_file, error) &&
+ system_timezone_update_config (tz, error);
+
+ g_free (zone_file);
+
+ return retval;
+}
+
+GQuark
+system_timezone_error_quark (void)
+{
+ static GQuark ret = 0;
+
+ if (ret == 0) {
+ ret = g_quark_from_static_string ("system-timezone-error");
+ }
+
+ return ret;
+}