Handle carrier changes by bond devicesbg/pr/18

This batch changes the way carrier changes are handled by bond
devices. With this patch:
* Pulling cable out of one of the slaves brings slave into disconnected state.
* Reconnecting cable reconnects slave automatically.
* Pulling out cables of all slaves brings down bond interface - removing its IP configuration.
* Reconnecting cable to one of the slaves makes bond interface reistablish its IP configuration.

With this patch bond interface is made to work like any other interface supporting carrier.
This patch has also been tested with bond interface having one ethernet and one wifi device - and it works as expected.

This patch allows one to have bond interface between wifi and ethernet and stil be able to connect to other wifi networks and not have ip config or routing clashes.

Signed-off-by: Nikolay Martynov <mar.kolya@gmail.com>

2 files changed, 38 insertions, 40 deletions

diff --git a/src/devices/nm-device-bond.c b/src/devices/nm-device-bond.c
index 3325c9485e..d2b7b2f15b 100644
--- a/src/devices/nm-device-bond.c
+++ b/src/devices/nm-device-bond.c
@@ -58,24 +58,6 @@ get_generic_capabilities (NMDevice *dev)
 }
 
 static gboolean
-is_available (NMDevice *dev, NMDeviceCheckDevAvailableFlags flags)
-{
-	return TRUE;
-}
-
-static gboolean
-check_connection_available (NMDevice *device,
-                            NMConnection *connection,
-                            NMDeviceCheckConAvailableFlags flags,
-                            const char *specific_object)
-{
-	/* Connections are always available because the carrier state is determined
-	 * by the slave carrier states, not the bonds's state.
-	 */
-	return TRUE;
-}
-
-static gboolean
 check_connection_compatible (NMDevice *device, NMConnection *connection)
 {
 	NMSettingBond *s_bond;
@@ -623,9 +605,7 @@ nm_device_bond_class_init (NMDeviceBondClass *klass)
 	NM_DEVICE_CLASS_DECLARE_TYPES (klass, NM_SETTING_BOND_SETTING_NAME, NM_LINK_TYPE_BOND)
 
 	parent_class->get_generic_capabilities = get_generic_capabilities;
-	parent_class->is_available = is_available;
 	parent_class->check_connection_compatible = check_connection_compatible;
-	parent_class->check_connection_available = check_connection_available;
 	parent_class->complete_connection = complete_connection;
 
 	parent_class->update_connection = update_connection;
diff --git a/src/devices/nm-device.c b/src/devices/nm-device.c
index 2fccf50c75..b520178369 100644
--- a/src/devices/nm-device.c
+++ b/src/devices/nm-device.c
@@ -2195,24 +2195,33 @@ carrier_changed (NMDevice *self, gboolean carrier)
 		return;
 
 	if (priv->is_master) {
-		/* Bridge/bond/team carrier does not affect its own activation,
-		 * but when carrier comes on, if there are slaves waiting,
-		 * it will restart them.
-		 */
-		if (!carrier)
-			return;
-
-		if (nm_device_activate_ip4_state_in_wait (self))
-			nm_device_activate_stage3_ip4_start (self);
-		if (nm_device_activate_ip6_state_in_wait (self))
-			nm_device_activate_stage3_ip6_start (self);
-
-		return;
-	} else if (priv->is_enslaved && !carrier) {
-		/* Slaves don't deactivate when they lose carrier; for
-		 * bonds/teams in particular that would be actively
-		 * counterproductive.
-		 */
+		if (carrier) {
+			/* Force master to retry getting ip addresses when carrier
+			 * is restored.
+			 */
+			if (priv->state == NM_DEVICE_STATE_ACTIVATED) {
+				nm_device_update_dynamic_ip_setup (self);
+			} else {
+				if (nm_device_activate_ip4_state_in_wait (self))
+					nm_device_activate_stage3_ip4_start (self);
+				if (nm_device_activate_ip6_state_in_wait (self))
+					nm_device_activate_stage3_ip6_start (self);
+			}
+		} else {
+			/* Put master device into DISCONNECTED state if there is
+			 * no carrier. This would mean that all slaves are still
+			 * enslaved. This is nessesary to be able to reconnect
+			 * when carrier appears.
+			 */
+			if (priv->state == NM_DEVICE_STATE_DISCONNECTED) {
+				if (   priv->queued_state.id
+					&& priv->queued_state.state >= NM_DEVICE_STATE_PREPARE)
+					queued_state_clear (self);
+			} else {
+				nm_device_queue_state (self, NM_DEVICE_STATE_DISCONNECTED,
+									   NM_DEVICE_STATE_REASON_CARRIER);
+			}
+		}
 		return;
 	}
 
@@ -3693,7 +3702,12 @@ is_available (NMDevice *self, NMDeviceCheckDevAvailableFlags flags)
 {
 	NMDevicePrivate *priv = NM_DEVICE_GET_PRIVATE (self);
 
-	if (priv->carrier || priv->ignore_carrier)
+	/* Device is available if:
+     * - carrier is present, or
+     * - carrier is ignored, or
+     * - device is master - master devices are always avaulable.
+	 */
+	if (priv->carrier || priv->ignore_carrier || priv->is_master)
 		return TRUE;
 
 	if (NM_FLAGS_HAS (flags, _NM_DEVICE_CHECK_DEV_AVAILABLE_IGNORE_CARRIER))
@@ -11590,9 +11604,13 @@ check_connection_available (NMDevice *self,
 
 	/* Connections which require a network connection are not available when
 	 * the device has no carrier, even with ignore-carrer=TRUE.
+	 * If this is master connection we assume it is available even if it
+	 * doesn't have carrier. Making connection non-available would for
+	 * NM to un-enslave slaves which is not desired.
 	 */
 	if (   priv->carrier
-	    || !connection_requires_carrier (connection))
+		|| priv->is_master
+		|| !connection_requires_carrier (connection))
 		return TRUE;
 
 	if (   NM_FLAGS_HAS (flags, _NM_DEVICE_CHECK_CON_AVAILABLE_FOR_USER_REQUEST_WAITING_CARRIER)