device/ndisc: add nm_ndisc_stop() method

It is bad style to rely on the last unref of an object for stopping
the operation. With a ref-counted object you should never rely on
anybody else still having (or not having) a reference. Hence, you
should not rely on stopping the ND during the last unref.

Add an explicit nm_ndisc_stop() function.

src/ndisc/nm-fake-ndisc.c

@@ -337,6 +337,14 @@ start (NMNDisc *ndisc)
 	priv->receive_ra_id = g_timeout_add_seconds (ra->when, receive_ra, ndisc);
 }
 
+static void
+stop (NMNDisc *ndisc)
+{
+	NMFakeNDiscPrivate *priv = NM_FAKE_NDISC_GET_PRIVATE (ndisc);
+
+	nm_clear_g_source (&priv->receive_ra_id);
+}
+
 void
 nm_fake_ndisc_emit_new_ras (NMFakeNDisc *self)
 {
@@ -388,7 +396,8 @@ nm_fake_ndisc_class_init (NMFakeNDiscClass *klass)
 
 	object_class->dispose = dispose;
 
-	ndisc_class->start = start;
+	ndisc_class->start   = start;
+	ndisc_class->stop    = stop;
 	ndisc_class->send_rs = send_rs;
 
 	signals[RS_SENT] =

src/ndisc/nm-lndp-ndisc.c

@@ -535,6 +535,36 @@ start (NMNDisc *ndisc)
 	}
 }
 
+static void
+_cleanup (NMNDisc *ndisc)
+{
+	NMLndpNDiscPrivate *priv = NM_LNDP_NDISC_GET_PRIVATE (ndisc);
+
+	nm_clear_g_source_inst (&priv->event_source);
+
+	if (priv->ndp) {
+		switch (nm_ndisc_get_node_type (ndisc)) {
+		case NM_NDISC_NODE_TYPE_HOST:
+			ndp_msgrcv_handler_unregister (priv->ndp, receive_ra, NDP_MSG_RA, nm_ndisc_get_ifindex (ndisc), ndisc);
+			break;
+		case NM_NDISC_NODE_TYPE_ROUTER:
+			ndp_msgrcv_handler_unregister (priv->ndp, receive_rs, NDP_MSG_RS, nm_ndisc_get_ifindex (ndisc), ndisc);
+			break;
+		default:
+			nm_assert_not_reached ();
+			break;
+		}
+		ndp_close (priv->ndp);
+		priv->ndp = NULL;
+	}
+}
+
+static void
+stop (NMNDisc *ndisc)
+{
+	_cleanup (ndisc);
+}
+
 /*****************************************************************************/
 
 static int
@@ -659,24 +689,8 @@ static void
 dispose (GObject *object)
 {
 	NMNDisc *ndisc = NM_NDISC (object);
-	NMLndpNDiscPrivate *priv = NM_LNDP_NDISC_GET_PRIVATE (ndisc);
 
-	nm_clear_g_source_inst (&priv->event_source);
+	_cleanup (ndisc);
-
-	if (priv->ndp) {
-		switch (nm_ndisc_get_node_type (ndisc)) {
-		case NM_NDISC_NODE_TYPE_HOST:
-			ndp_msgrcv_handler_unregister (priv->ndp, receive_ra, NDP_MSG_RA, nm_ndisc_get_ifindex (ndisc), ndisc);
-			break;
-		case NM_NDISC_NODE_TYPE_ROUTER:
-			ndp_msgrcv_handler_unregister (priv->ndp, receive_rs, NDP_MSG_RS, nm_ndisc_get_ifindex (ndisc), ndisc);
-			break;
-		default:
-			g_assert_not_reached ();
-		}
-		ndp_close (priv->ndp);
-		priv->ndp = NULL;
-	}
 
 	G_OBJECT_CLASS (nm_lndp_ndisc_parent_class)->dispose (object);
 }
@@ -688,7 +702,8 @@ nm_lndp_ndisc_class_init (NMLndpNDiscClass *klass)
 	NMNDiscClass *ndisc_class = NM_NDISC_CLASS (klass);
 
 	object_class->dispose = dispose;
-	ndisc_class->start = start;
+	ndisc_class->start    = start;
-	ndisc_class->send_rs = send_rs;
+	ndisc_class->stop     = stop;
-	ndisc_class->send_ra = send_ra;
+	ndisc_class->send_rs  = send_rs;
+	ndisc_class->send_ra  = send_ra;
 }

src/ndisc/nm-ndisc.c

@@ -960,6 +960,53 @@ nm_ndisc_start (NMNDisc *ndisc)
 	announce_router_initial (ndisc);
 }
 
+void
+nm_ndisc_stop (NMNDisc *ndisc)
+{
+	nm_auto_pop_netns NMPNetns *netns = NULL;
+	NMNDiscDataInternal *rdata;
+	NMNDiscPrivate *priv;
+
+	g_return_if_fail (NM_IS_NDISC (ndisc));
+
+	priv = NM_NDISC_GET_PRIVATE (ndisc);
+
+	nm_assert (NM_NDISC_GET_CLASS (ndisc)->stop);
+
+	_LOGD ("stopping neighbor discovery for ifindex %d",
+	       priv->ifindex);
+
+	if (!nm_ndisc_netns_push (ndisc, &netns))
+		return;
+
+	NM_NDISC_GET_CLASS (ndisc)->stop (ndisc);
+
+	rdata = &priv->rdata;
+
+	g_array_set_size (rdata->gateways, 0);
+	g_array_set_size (rdata->addresses, 0);
+	g_array_set_size (rdata->routes, 0);
+	g_array_set_size (rdata->dns_servers, 0);
+	g_array_set_size (rdata->dns_domains, 0);
+	priv->rdata.public.hop_limit = 64;
+
+	/* Start at very low number so that last_rs - router_solicitation_interval
+	 * is much lower than nm_utils_get_monotonic_timestamp_sec() at startup.
+	 */
+	priv->last_rs = G_MININT32;
+	nm_clear_g_source_inst (&priv->ra_timeout_source);
+	nm_clear_g_source (&priv->send_rs_id);
+	nm_clear_g_source (&priv->send_ra_id);
+	nm_clear_g_free (&priv->last_error);
+	nm_clear_g_source (&priv->timeout_id);
+
+	priv->solicitations_left = 0;
+	priv->announcements_left = 0;
+
+	priv->last_rs = G_MININT32;
+	priv->last_ra = G_MININT32;
+}
+
 NMNDiscConfigMap
 nm_ndisc_dad_failed (NMNDisc *ndisc, const struct in6_addr *address, gboolean emit_changed_signal)
 {

src/ndisc/nm-ndisc.h

@@ -163,6 +163,7 @@ typedef struct {
 	GObjectClass parent;
 
 	void (*start) (NMNDisc *ndisc);
+	void (*stop) (NMNDisc *ndisc);
 	gboolean (*send_rs) (NMNDisc *ndisc, GError **error);
 	gboolean (*send_ra) (NMNDisc *ndisc, GError **error);
 } NMNDiscClass;
@@ -177,6 +178,7 @@ NMNDiscNodeType nm_ndisc_get_node_type (NMNDisc *self);
 
 gboolean nm_ndisc_set_iid (NMNDisc *ndisc, const NMUtilsIPv6IfaceId iid);
 void nm_ndisc_start (NMNDisc *ndisc);
+void nm_ndisc_stop (NMNDisc *ndisc);
 NMNDiscConfigMap nm_ndisc_dad_failed (NMNDisc *ndisc,
                                       const struct in6_addr *address,
                                       gboolean emit_changed_signal);