dns: replace the FAILED and CHILD_QUIT signals with a STATE property

When we'll supporting multiple DNS plugins, we'll need to know whether a
particular plugin is in a workable state instead of just reacting to state
change events.

6 files changed, 127 insertions, 61 deletions

diff --git a/src/dns/nm-dns-dnsmasq.c b/src/dns/nm-dns-dnsmasq.c
index df3ca11120..91a42a6e61 100644
--- a/src/dns/nm-dns-dnsmasq.c
+++ b/src/dns/nm-dns-dnsmasq.c
@@ -430,8 +430,10 @@ name_owner_changed (GObject    *object,
 	} else {
 		_LOGI ("dnsmasq disappeared");
 		priv->running = FALSE;
-		g_signal_emit_by_name (self, NM_DNS_PLUGIN_FAILED);
 	}
+
+	nm_dns_plugin_set_state (NM_DNS_PLUGIN (self),
+	                         priv->running ? NM_DNS_PLUGIN_STATE_RUNNING : NM_DNS_PLUGIN_STATE_FAILED);
 }
 
 static void
@@ -452,7 +454,7 @@ dnsmasq_proxy_cb (GObject *source, GAsyncResult *res, gpointer user_data)
 
 	if (!proxy) {
 		_LOGW ("failed to connect to dnsmasq via DBus: %s", error->message);
-		g_signal_emit_by_name (self, NM_DNS_PLUGIN_FAILED);
+		nm_dns_plugin_set_state (NM_DNS_PLUGIN (self), NM_DNS_PLUGIN_STATE_FAILED);
 		return;
 	}
 
diff --git a/src/dns/nm-dns-manager.c b/src/dns/nm-dns-manager.c
index f5776d13a7..e048f9bc78 100644
--- a/src/dns/nm-dns-manager.c
+++ b/src/dns/nm-dns-manager.c
@@ -147,6 +147,8 @@ G_DEFINE_TYPE (NMDnsManager, nm_dns_manager, NM_TYPE_EXPORTED_OBJECT)
 
 #define NM_DNS_MANAGER_GET_PRIVATE(self) _NM_GET_PRIVATE(self, NMDnsManager, NM_IS_DNS_MANAGER)
 
+static void plugin_state_changed (NMDnsPlugin *plugin, GParamSpec *pspec, gpointer user_data);
+
 static gboolean
 domain_is_valid (const gchar *domain)
 {
@@ -1132,6 +1134,7 @@ update_dns (NMDnsManager *self,
 		caching = TRUE;
 
 		_LOGD ("update-dns: updating plugin %s", plugin_name);
+		g_signal_handlers_block_by_func (plugin, plugin_state_changed, self);
 		if (!nm_dns_plugin_update (plugin,
 		                           priv->configs,
 		                           global_config,
@@ -1143,6 +1146,7 @@ update_dns (NMDnsManager *self,
 			 */
 			caching = FALSE;
 		}
+		g_signal_handlers_unblock_by_func (plugin, plugin_state_changed, self);
 
 	skip:
 		;
@@ -1204,28 +1208,29 @@ update_dns (NMDnsManager *self,
 }
 
 static void
-plugin_failed (NMDnsPlugin *plugin, gpointer user_data)
-{
-	NMDnsManager *self = NM_DNS_MANAGER (user_data);
-	GError *error = NULL;
-
-	/* Disable caching until the next DNS update */
-	if (!update_dns (self, TRUE, &error)) {
-		_LOGW ("could not commit DNS changes: %s", error->message);
-		g_clear_error (&error);
-	}
-}
-
-static void
-plugin_child_quit (NMDnsPlugin *plugin, gpointer user_data)
+plugin_state_changed (NMDnsPlugin *plugin, GParamSpec *pspec, gpointer user_data)
 {
 	NMDnsManager *self = NM_DNS_MANAGER (user_data);
 	GError *error = NULL;
+	const char *plugin_name = nm_dns_plugin_get_name (plugin);
 
-	/* Let the plugin try to spawn the child again */
-	if (!update_dns (self, FALSE, &error)) {
-		_LOGW ("could not commit DNS changes: %s", error->message);
-		g_clear_error (&error);
+	switch (nm_dns_plugin_get_state (plugin)) {
+	case NM_DNS_PLUGIN_STATE_STOPPED:
+		_LOGI ("dns: plugin %s stopped, restarting it", plugin_name);
+		if (!update_dns (self, FALSE, &error)) {
+			_LOGW ("could not commit DNS changes: %s", error->message);
+			g_clear_error (&error);
+		}
+		break;
+	case NM_DNS_PLUGIN_STATE_FAILED:
+		_LOGW ("dns: plugin %s failed", plugin_name);
+		if (!update_dns (self, TRUE, &error)) {
+			_LOGW ("could not commit DNS changes: %s", error->message);
+			g_clear_error (&error);
+		}
+		break;
+	default:
+		return;
 	}
 }
 
@@ -1524,8 +1529,7 @@ _clear_plugin (NMDnsManager *self)
 	NMDnsManagerPrivate *priv = NM_DNS_MANAGER_GET_PRIVATE (self);
 
 	if (priv->plugin) {
-		g_signal_handlers_disconnect_by_func (priv->plugin, plugin_failed, self);
-		g_signal_handlers_disconnect_by_func (priv->plugin, plugin_child_quit, self);
+		g_signal_handlers_disconnect_by_func (priv->plugin, plugin_state_changed, self);
 		nm_dns_plugin_stop (priv->plugin);
 		g_clear_object (&priv->plugin);
 		return TRUE;
@@ -1725,10 +1729,8 @@ again:
 			plugin_changed = TRUE;
 	}
 
-	if (plugin_changed && priv->plugin) {
-		g_signal_connect (priv->plugin, NM_DNS_PLUGIN_FAILED, G_CALLBACK (plugin_failed), self);
-		g_signal_connect (priv->plugin, NM_DNS_PLUGIN_CHILD_QUIT, G_CALLBACK (plugin_child_quit), self);
-	}
+	if (plugin_changed && priv->plugin)
+		g_signal_connect (priv->plugin, "notify::" NM_DNS_PLUGIN_STATE, G_CALLBACK (plugin_state_changed), self);
 
 	g_object_freeze_notify (G_OBJECT (self));
 
diff --git a/src/dns/nm-dns-plugin.c b/src/dns/nm-dns-plugin.c
index 6d65913d51..a998da5807 100644
--- a/src/dns/nm-dns-plugin.c
+++ b/src/dns/nm-dns-plugin.c
@@ -36,19 +36,16 @@
 #define PLUGIN_RATELIMIT_BURST       5
 #define PLUGIN_RATELIMIT_DELAY       300
 
-enum {
-	FAILED,
-	CHILD_QUIT,
-	LAST_SIGNAL,
-};
-
-static guint signals[LAST_SIGNAL] = { 0 };
+NM_GOBJECT_PROPERTIES_DEFINE (NMDnsPlugin,
+	PROP_STATE,
+);
 
 typedef struct _NMDnsPluginPrivate {
 	GPid pid;
 	guint watch_id;
 	char *progname;
 	char *pidfile;
+	NMDnsPluginState state;
 
 	struct {
 		guint64 ts;
@@ -173,7 +170,7 @@ emit_ratelimited_child_quit (gpointer user_data)
 {
 	NMDnsPlugin *self = NM_DNS_PLUGIN (user_data);
 
-	g_signal_emit (self, signals[CHILD_QUIT], 0);
+	nm_dns_plugin_set_state (self, NM_DNS_PLUGIN_STATE_STOPPED);
 
 	return G_SOURCE_REMOVE;
 }
@@ -213,9 +210,9 @@ watch_cb (GPid pid, gint status, gpointer user_data)
 	}
 
 	if (failed)
-		g_signal_emit (self, signals[FAILED], 0);
+		nm_dns_plugin_set_state (self, NM_DNS_PLUGIN_STATE_FAILED);
 	else
-		g_signal_emit (self, signals[CHILD_QUIT], 0);
+		nm_dns_plugin_set_state (self, NM_DNS_PLUGIN_STATE_STOPPED);
 }
 
 /*****************************************************************************/
@@ -307,6 +304,64 @@ nm_dns_plugin_stop (NMDnsPlugin *self)
 
 /*****************************************************************************/
 
+NMDnsPluginState
+nm_dns_plugin_get_state (NMDnsPlugin *self)
+{
+	NMDnsPluginPrivate *priv = NM_DNS_PLUGIN_GET_PRIVATE (self);
+
+	return priv->state;
+}
+
+void
+nm_dns_plugin_set_state (NMDnsPlugin *self, NMDnsPluginState state)
+{
+	NMDnsPluginPrivate *priv = NM_DNS_PLUGIN_GET_PRIVATE (self);
+
+	if (priv->state == state)
+		return;
+
+	priv->state = state;
+	_notify (self, PROP_STATE);
+}
+
+/*****************************************************************************/
+
+static void
+get_property (GObject *object, guint prop_id,
+              GValue *value, GParamSpec *pspec)
+{
+	NMDnsPlugin *self = NM_DNS_PLUGIN (object);
+	NMDnsPluginPrivate *priv = NM_DNS_PLUGIN_GET_PRIVATE (self);
+
+	switch (prop_id) {
+	case PROP_STATE:
+		g_value_set_uint (value, priv->state);
+		break;
+	default:
+		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+		break;
+	}
+}
+
+static void
+set_property (GObject *object, guint prop_id,
+              const GValue *value, GParamSpec *pspec)
+{
+	NMDnsPlugin *self = NM_DNS_PLUGIN (object);
+	NMDnsPluginPrivate *priv = NM_DNS_PLUGIN_GET_PRIVATE (self);
+
+	switch (prop_id) {
+	case PROP_STATE:
+		priv->state = g_value_get_uint (value);
+		break;
+	default:
+		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+		break;
+	}
+}
+
+/*****************************************************************************/
+
 static void
 nm_dns_plugin_init (NMDnsPlugin *self)
 {
@@ -330,26 +385,17 @@ nm_dns_plugin_class_init (NMDnsPluginClass *plugin_class)
 
 	g_type_class_add_private (plugin_class, sizeof (NMDnsPluginPrivate));
 
+	object_class->get_property = get_property;
+	object_class->set_property = set_property;
 	object_class->dispose = dispose;
 
-	/* Emitted by the plugin and consumed by NMDnsManager when
-	 * some error happens with the nameserver subprocess.  Causes NM to fall
-	 * back to writing out a non-local-caching resolv.conf until the next
-	 * DNS update.
-	 */
-	signals[FAILED] =
-	    g_signal_new (NM_DNS_PLUGIN_FAILED,
-	                  G_OBJECT_CLASS_TYPE (object_class),
-	                  G_SIGNAL_RUN_FIRST,
-	                  0, NULL, NULL,
-	                  g_cclosure_marshal_VOID__VOID,
-	                  G_TYPE_NONE, 0);
-
-	signals[CHILD_QUIT] =
-	    g_signal_new (NM_DNS_PLUGIN_CHILD_QUIT,
-	                  G_OBJECT_CLASS_TYPE (object_class),
-	                  G_SIGNAL_RUN_FIRST,
-	                  0, NULL, NULL,
-	                  g_cclosure_marshal_VOID__VOID,
-	                  G_TYPE_NONE, 0);
+	obj_properties[PROP_STATE] =
+	    g_param_spec_uint (NM_DNS_PLUGIN_STATE, "", "",
+	                       NM_DNS_PLUGIN_STATE_STOPPED,
+	                       NM_DNS_PLUGIN_STATE_FAILED,
+	                       NM_DNS_PLUGIN_STATE_STOPPED,
+	                       G_PARAM_READABLE
+	                         | G_PARAM_STATIC_STRINGS);
+
+	g_object_class_install_properties (object_class, _PROPERTY_ENUMS_LAST, obj_properties);
 }
diff --git a/src/dns/nm-dns-plugin.h b/src/dns/nm-dns-plugin.h
index c37c657e01..e4a6cd40fa 100644
--- a/src/dns/nm-dns-plugin.h
+++ b/src/dns/nm-dns-plugin.h
@@ -29,8 +29,7 @@
 #define NM_IS_DNS_PLUGIN_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), NM_TYPE_DNS_PLUGIN))
 #define NM_DNS_PLUGIN_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), NM_TYPE_DNS_PLUGIN, NMDnsPluginClass))
 
-#define NM_DNS_PLUGIN_FAILED "failed"
-#define NM_DNS_PLUGIN_CHILD_QUIT "child-quit"
+#define NM_DNS_PLUGIN_STATE "state"
 
 struct _NMDnsPluginPrivate;
 
@@ -64,10 +63,19 @@ typedef struct {
 	gboolean (*child_quit) (NMDnsPlugin *self, gint status);
 } NMDnsPluginClass;
 
+typedef enum {
+	NM_DNS_PLUGIN_STATE_STOPPED,
+	NM_DNS_PLUGIN_STATE_RUNNING,
+	NM_DNS_PLUGIN_STATE_FAILED,
+} NMDnsPluginState;
+
 GType nm_dns_plugin_get_type (void);
 
 const char *nm_dns_plugin_get_name (NMDnsPlugin *self);
 
+NMDnsPluginState nm_dns_plugin_get_state (NMDnsPlugin *self);
+void             nm_dns_plugin_set_state (NMDnsPlugin *self, NMDnsPluginState state);
+
 gboolean nm_dns_plugin_update (NMDnsPlugin *self,
                                const GPtrArray *configs,
                                const NMGlobalDnsConfig *global_config,
diff --git a/src/dns/nm-dns-systemd-resolved.c b/src/dns/nm-dns-systemd-resolved.c
index d090de3f80..a48f78d259 100644
--- a/src/dns/nm-dns-systemd-resolved.c
+++ b/src/dns/nm-dns-systemd-resolved.c
@@ -353,10 +353,11 @@ resolved_proxy_created (GObject *source, GAsyncResult *r, gpointer user_data)
 	g_clear_object (&priv->init_cancellable);
 	if (!resolve) {
 		_LOGW ("failed to connect to resolved via DBus: %s", error->message);
-		g_signal_emit_by_name (self, NM_DNS_PLUGIN_FAILED);
+		nm_dns_plugin_set_state (NM_DNS_PLUGIN (self), NM_DNS_PLUGIN_STATE_FAILED);
 		return;
 	}
 
+	nm_dns_plugin_set_state (NM_DNS_PLUGIN (self), NM_DNS_PLUGIN_STATE_RUNNING);
 	priv->resolve = resolve;
 	send_updates (self);
 }
diff --git a/src/dns/nm-dns-unbound.c b/src/dns/nm-dns-unbound.c
index 0d2dc0adb2..e86e51e08a 100644
--- a/src/dns/nm-dns-unbound.c
+++ b/src/dns/nm-dns-unbound.c
@@ -45,6 +45,7 @@ update (NMDnsPlugin *plugin,
 {
 	char *argv[] = { DNSSEC_TRIGGER_SCRIPT, "--async", "--update", NULL };
 	int status;
+	gboolean success;
 
 	/* TODO: We currently call a script installed with the dnssec-trigger
 	 * package that queries all information itself. Later, the dependency
@@ -56,8 +57,14 @@ update (NMDnsPlugin *plugin,
 	 * may be eventually merged into NetworkManager.
 	 */
 	if (!g_spawn_sync ("/", argv, NULL, 0, NULL, NULL, NULL, NULL, &status, NULL))
-		return FALSE;
-	return (status == 0);
+		success = FALSE;
+	else
+		success = (status == 0);
+
+	nm_dns_plugin_set_state (plugin,
+	                         success ? NM_DNS_PLUGIN_STATE_RUNNING : NM_DNS_PLUGIN_STATE_FAILED);
+
+	return success;
 }
 
 static const char *