timeserver: Create timeserver list

Create a timeserver list for NTP query. This list consists of
timeserver provided via DHCP and the ones set by user in that
order. We recreate this list everytime the default service changes
or one of the timeserver values change.

Use getaddrinfo to determine if the timeserver is a domain name or
a IP address.

2 files changed, 119 insertions, 83 deletions

diff --git a/src/connman.h b/src/connman.h
index 49a1586a..463b3b77 100644
--- a/src/connman.h
+++ b/src/connman.h
@@ -371,7 +371,6 @@ char **__connman_timeserver_system_get();
 
 int __connman_timeserver_sync(struct connman_service *service);
 void __connman_timeserver_sync_next();
-void __connman_timeserver_stop();
 
 typedef void (* dhcp_cb) (struct connman_network *network,
 				connman_bool_t success);
diff --git a/src/timeserver.c b/src/timeserver.c
index 8622431e..cfa4a82f 100644
--- a/src/timeserver.c
+++ b/src/timeserver.c
@@ -28,15 +28,14 @@
 #include <glib.h>
 #include <stdlib.h>
 #include <gweb/gresolv.h>
+#include <netdb.h>
 
 #include "connman.h"
 
-static char **system_timeservers = NULL;
-static char **timeservers = NULL;
+static GSList *ts_list = NULL;
 
 static GResolv *resolv = NULL;
 static int resolv_id = 0;
-static volatile int count;
 
 static void resolv_debug(const char *str, void *data)
 {
@@ -85,48 +84,12 @@ static char **load_timeservers()
 	return servers;
 }
 
-/* Restart NTP procedure */
-static void connman_timeserver_restart()
-{
-	/* If service timeservers are in use, dont restart ntp */
-	if (timeservers != NULL)
-		return;
-
-	if (resolv == NULL) {
-		DBG("No online service.");
-		return;
-	}
-
-	/* Cancel current lookup */
-	if(resolv_id > 0)
-		g_resolv_cancel_lookup(resolv, resolv_id);
-
-	/* Reload system timeserver list */
-	if (system_timeservers != NULL) {
-		g_strfreev(system_timeservers);
-		system_timeservers = NULL;
-	}
-
-	system_timeservers = load_timeservers();
-
-	if (system_timeservers == NULL)
-		return;
-
-	__connman_ntp_stop();
-
-	count = 0;
-
-	__connman_timeserver_sync_next();
-}
-
 static void resolv_result(GResolvResultStatus status, char **results, gpointer user_data)
 {
 	int i;
 
 	DBG("status %d", status);
 
-	__sync_fetch_and_add(&count, 1);
-
 	if (status == G_RESOLV_RESULT_STATUS_SUCCESS) {
 		if (results != NULL) {
 			for (i = 0; results[i]; i++)
@@ -138,27 +101,74 @@ static void resolv_result(GResolvResultStatus status, char **results, gpointer u
 		}
 	}
 
+	/* If resolving fails, move to the next server */
 	__connman_timeserver_sync_next();
 }
 
+/*
+ * Once the timeserver list (ts_list) is created, we start querying the
+ * servers one by one. If resolving fails on one of them, we move to the
+ * next one. The user can enter either an IP address or a URL for the
+ * timeserver. We only resolve the urls. Once we have a IP for the NTP
+ * server, we start querying it for time corrections.
+ */
 void __connman_timeserver_sync_next()
 {
-	if (system_timeservers == NULL ||
-	system_timeservers[count] == NULL)
+	char *server;
+	int ret;
+	struct addrinfo hints;
+	struct addrinfo *addr;
+
+	__connman_ntp_stop();
+
+	/* Get the 1st server in the list */
+	if (ts_list == NULL)
+		return;
+
+	server = ts_list->data;
+
+	ts_list = g_slist_delete_link(ts_list, ts_list);
+
+	memset(&hints, 0, sizeof(struct addrinfo));
+	hints.ai_flags = AI_NUMERICHOST;
+	addr = NULL;
+
+	ret = getaddrinfo(server, NULL, &hints, &addr);
+	freeaddrinfo(addr);
+
+	/* if its a IP , directly query it. */
+	if (ret == 0) {
+		DBG("Using timeservers %s", server);
+
+		__connman_ntp_start(server);
+
+		g_free(server);
 		return;
+	}
 
-	DBG("Trying timeserver %s", system_timeservers[count]);
+	DBG("Resolving server %s", server);
 
-	if (resolv)
-		resolv_id = g_resolv_lookup_hostname(resolv,
-			system_timeservers[count], resolv_result,
-						NULL);
+	resolv_id = g_resolv_lookup_hostname(resolv, server,
+						resolv_result, NULL);
+
+	g_free(server);
+
+	return;
 }
 
+
+/*
+ * __connman_timeserver_sync function recreates the timeserver
+ * list which will be used to determine NTP server for time corrections.
+ * It must be called everytime the default service changes, the service
+ * timeserver(s) changes or the global timeserver(s) changes.The service
+ * settings take priority over the global timeservers.
+ */
 int __connman_timeserver_sync(struct connman_service *default_service)
 {
 	struct connman_service *service;
-	char **nameservers;
+	char **timeservers;
+	char **service_ts;
 	int i;
 
 	if (default_service != NULL)
@@ -169,6 +179,50 @@ int __connman_timeserver_sync(struct connman_service *default_service)
 	if (service == NULL)
 		return -EINVAL;
 
+	if (resolv == NULL)
+		return 0;
+	/*
+	 * Before be start creating the new timeserver list we must stop
+	 * any ongoing ntp query and server resolution.
+	 */
+
+	__connman_ntp_stop();
+
+	if (resolv_id > 0)
+		g_resolv_cancel_lookup(resolv, resolv_id);
+
+	if (ts_list != NULL) {
+		g_slist_free_full(ts_list, g_free);
+		ts_list = NULL;
+	}
+
+	service_ts = connman_service_get_timeservers(service);
+
+	for (i=0; service_ts != NULL && service_ts[i] != NULL; i++)
+		ts_list = g_slist_prepend(ts_list, g_strdup(service_ts[i]));
+
+	timeservers = load_timeservers();
+
+	for (i=0; timeservers != NULL && timeservers[i] != NULL; i++)
+		ts_list = g_slist_prepend(ts_list, g_strdup(timeservers[i]));
+
+	if (ts_list == NULL) {
+		DBG("No timeservers set.");
+		return 0;
+	}
+
+	ts_list = g_slist_reverse(ts_list);
+
+        __connman_timeserver_sync_next();
+
+	return 0;
+}
+
+static int timeserver_start(struct connman_service *service)
+{
+	char **nameservers;
+	int i;
+
 	DBG("service %p", service);
 
 	i = __connman_service_get_index(service);
@@ -179,6 +233,16 @@ int __connman_timeserver_sync(struct connman_service *default_service)
 	if (nameservers == NULL)
 		return -EINVAL;
 
+	/* Stop an already ongoing resolution, if there is one */
+	if (resolv_id > 0)
+		g_resolv_cancel_lookup(resolv, resolv_id);
+
+	/* get rid of the old resolver */
+	if (resolv != NULL) {
+		g_resolv_unref(resolv);
+		resolv = NULL;
+	}
+
 	resolv = g_resolv_new(i);
 	if (resolv == NULL)
 		return -ENOMEM;
@@ -189,31 +253,10 @@ int __connman_timeserver_sync(struct connman_service *default_service)
 	for (i = 0; nameservers[i] != NULL; i++)
 		g_resolv_add_nameserver(resolv, nameservers[i], 53, 0);
 
-	count = 0;
-
-	system_timeservers = load_timeservers();
-
-	timeservers = connman_service_get_timeservers(service);
-
-	if (timeservers != NULL && timeservers[0] != NULL) {
-		DBG("Using service tiemservers");
-		__connman_ntp_start(timeservers[0]);
-		return 0;
-	}
-
-	if (system_timeservers == NULL || system_timeservers[count] == NULL) {
-		DBG("No timeservers set.");
-		return 0;
-	}
-
-	DBG("Trying server %s", system_timeservers[count]);
-
-	resolv_id = g_resolv_lookup_hostname(resolv, system_timeservers[count],
-						resolv_result, NULL);
-	return 0;
+	return __connman_timeserver_sync(service);
 }
 
-void __connman_timeserver_stop()
+static void timeserver_stop()
 {
 	DBG(" ");
 
@@ -222,14 +265,10 @@ void __connman_timeserver_stop()
 		resolv = NULL;
 	}
 
-	if (system_timeservers != NULL) {
-		g_strfreev(system_timeservers);
-		system_timeservers = NULL;
-	}
-
-	timeservers = NULL;
+	if (ts_list != NULL)
+		g_slist_free_full(ts_list, g_free);
 
-	count = 0;
+	ts_list = NULL;
 
 	__connman_ntp_stop();
 }
@@ -238,7 +277,7 @@ int __connman_timeserver_system_set(char **servers)
 {
 	save_timeservers(servers);
 
-	connman_timeserver_restart();
+	__connman_timeserver_sync(NULL);
 
 	return 0;
 }
@@ -253,12 +292,10 @@ char **__connman_timeserver_system_get()
 
 static void default_changed(struct connman_service *default_service)
 {
-	DBG("");
-
 	if (default_service != NULL)
-		__connman_timeserver_sync(default_service);
+		timeserver_start(default_service);
 	else
-		__connman_timeserver_stop();
+		timeserver_stop();
 }
 
 static struct connman_notifier timeserver_notifier = {