If we are running under systemd, the ProtectSystem key in our .service file prevents us from writing to /etc/localtime. Instead, set the timezone by using org.freedesktop.timedate1 over D-Bus, if it is available. If it is not available, fall back to /etc/localtime. Signed-off-by: Philip Withnall <philip.withnall(a)collabora.co.uk&gt; ---  src/timezone.c | 213 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-  1 file changed, 210 insertions(+), 3 deletions(-) diff --git a/src/timezone.c b/src/timezone.c index e346b11..c74bfdd 100644 --- a/src/timezone.c +++ b/src/timezone.c @@ -38,11 +38,46 @@  #include <glib.h>    #include "connman.h" +#include "gdbus.h"    #define ETC_LOCALTIME "/etc/localtime"  #define ETC_SYSCONFIG_CLOCK "/etc/sysconfig/clock"  #define USR_SHARE_ZONEINFO "/usr/share/zoneinfo"   +/* See https://www.freedesktop.org/wiki/Software/systemd/timedated/ for + * reference. */ +#define TIMEDATED_SERVICE "org.freedesktop.timedate1" +#define TIMEDATED_INTERFACE TIMEDATED_SERVICE +#define TIMEDATED_PATH "/org/freedesktop/timedate1" + +static GDBusClient *timedated_client = NULL; +static GDBusProxy *timedated_proxy = NULL; +static gchar *timedated_timezone = NULL; + +static void timedate_property_changed(GDBusProxy *proxy, const char *name, + DBusMessageIter *iter, void *user_data) +{ + DBG("Property %s", name); + + if (g_str_equal(name, "Timezone")) { + const char *str; + + if (!iter) { + g_dbus_proxy_refresh_property(proxy, name); + return; + } + + if (dbus_message_iter_get_arg_type(iter) != DBUS_TYPE_STRING) + return; + + dbus_message_iter_get_basic(iter, &str); + g_free(timedated_timezone); + timedated_timezone = g_strdup(str); + + DBG("Timezone set to %s", timedated_timezone); + } +} +  static char *read_key_file(const char *pathname, const char *key)  {   struct stat st; @@ -226,7 +261,36 @@ static char *find_origin(void *src_map, struct stat *src_st,   return NULL;  }   -char *__connman_timezone_lookup(void) +/* Query the timezone from org.freedesktop.timedate1. */ +static char *__connman_timezone_lookup_dbus(void) +{ + DBusMessageIter iter; + const char *str; + + DBG(""); + + /* If timedated_timezone is set, we have been notified of the timezone +  * previously. */ + if (timedated_proxy && timedated_timezone) + return timedated_timezone; + + /* Not connected to the D-Bus service? */ + if (!timedated_proxy) + return NULL; + + /* Query D-Bus and update the cache. */ + if (!g_dbus_proxy_get_property(timedated_proxy, "Timezone", &iter)) + return NULL; + dbus_message_iter_get_basic(&iter, &str); + + g_free(timedated_timezone); + timedated_timezone = g_strdup(str); + + return g_strdup(timedated_timezone); +} + +/* Look up the timezone from /etc/sysconfig/clock or /etc/localtime. */ +static char *__connman_timezone_lookup_filesystem(void)  {   struct stat st;   void *map; @@ -284,6 +348,20 @@ done:   return zone;  }   +char *__connman_timezone_lookup(void) +{ + char *timezone; + + DBG(""); + + /* Try D-Bus first; then fall back to the filesystem. */ + timezone = __connman_timezone_lookup_dbus(); + if (timezone) + return timezone; + + return __connman_timezone_lookup_filesystem(); +} +  static int write_file(void *src_map, struct stat *src_st, const char *pathname)  {   struct stat st; @@ -311,7 +389,53 @@ static int write_file(void *src_map, struct stat *src_st, const char *pathname)   return 0;  }   -int __connman_timezone_change(const char *zone) +static void timezone_change_dbus_cb(DBusMessage *message, void *user_data) +{ + const char *zone = user_data; + + if (dbus_message_get_type(message) == DBUS_MESSAGE_TYPE_ERROR) { + const char *dbus_error = dbus_message_get_error_name(message); + + DBG("zone %s %s", zone, dbus_error); + } else { + DBG("zone %s success", zone); + } +} + +static void timezone_change_dbus_append(DBusMessageIter *iter, + void *user_data) +{ + const char *zone = user_data; + dbus_bool_t user_interaction = FALSE; + + /* The second parameter is user_interaction — whether polkit should ask +  * for credentials interactively if necessary. We do not want that. +  * +  * The polkit action controlling this is: +  * org.freedesktop.timedate1.set-timezone. */ + dbus_message_iter_append_basic(iter, DBUS_TYPE_STRING, &zone); + dbus_message_iter_append_basic(iter, DBUS_TYPE_BOOLEAN, &user_interaction); +} + +/* Set the timezone using org.freedesktop.timedate1. */ +static int __connman_timezone_change_dbus(const char *zone) +{ + /* Are we connected to the D-Bus service? */ + if (!timedated_proxy) + return -ENOENT; + + DBG("zone %s", zone); + + if (!g_dbus_proxy_method_call(timedated_proxy, "SetTimezone", + timezone_change_dbus_append, timezone_change_dbus_cb, + g_strdup(zone), g_free)) + return -EIO; + + return -EINPROGRESS; +} + +/* Set the timezone by overwriting /etc/localtime. */ +static int __connman_timezone_change_filesystem(const char *zone)  {   struct stat st;   char *map, pathname[PATH_MAX]; @@ -345,6 +469,23 @@ int __connman_timezone_change(const char *zone)   return err;  }   +int __connman_timezone_change(const char *zone) +{ + int err; + + DBG(""); + + /* Try D-Bus first; then fall back to the filesystem. This order is +  * important, as if we are running under systemd, /etc will be mounted +  * read-only (due to the ProtectSystem key in our .service file), and +  * hence only org.freedesktop.timedate1 can be used. */ + err = __connman_timezone_change_dbus(zone); + if (err >= 0 || err == -EINPROGRESS) + return 0; + + return __connman_timezone_change_filesystem(zone); +} +  static guint inotify_watch = 0;    static gboolean inotify_data(GIOChannel *channel, GIOCondition cond, @@ -402,7 +543,45 @@ static gboolean inotify_data(GIOChannel *channel, GIOCondition cond,   return TRUE;  }   -int __connman_timezone_init(void) +static int __connman_timezone_init_dbus(void) +{ + DBusConnection *connection; + int err = -EIO; + + DBG(""); + + /* Try connecting to org.freedesktop.timedate1 first. If that fails, +  * try /etc/localtime as a fallback. */ + connection = connman_dbus_get_connection(); + + timedated_client = g_dbus_client_new(connection, TIMEDATED_SERVICE, + TIMEDATED_PATH); + if (!timedated_client) + goto error; + + timedated_proxy = g_dbus_proxy_new(timedated_client, TIMEDATED_PATH, + TIMEDATED_INTERFACE); + if (!timedated_proxy) + goto error; + + g_dbus_proxy_set_property_watch(timedated_proxy, + timedate_property_changed, NULL); + + dbus_connection_unref(connection); + + return 0; +error: + if (timedated_client) { + g_dbus_client_unref(timedated_client); + timedated_client = NULL; + } + + dbus_connection_unref(connection); + + return err; +} + +static int __connman_timezone_init_filesystem(void)  {   GIOChannel *channel;   char *dirname; @@ -443,6 +622,21 @@ int __connman_timezone_init(void)   return 0;  }   +int __connman_timezone_init(void) +{ + int err; + + DBG(""); + + /* Try connecting to org.freedesktop.timedate1 first. If that fails, +  * try /etc/localtime as a fallback. */ + err = __connman_timezone_init_dbus(); + if (err >= 0) + return err; + + return __connman_timezone_init_filesystem(); +} +  void __connman_timezone_cleanup(void)  {   DBG(""); @@ -451,4 +645,17 @@ void __connman_timezone_cleanup(void)   g_source_remove(inotify_watch);   inotify_watch = 0;   } + + if (timedated_proxy) { + g_dbus_proxy_unref(timedated_proxy); + timedated_proxy = NULL; + } + + if (timedated_client) { + g_dbus_client_unref(timedated_client); + timedated_client = NULL; + } + + g_free(timedated_timezone); + timedated_timezone = NULL;  } --  2.7.4