From 17612d182004af4045b7e55654f231114e311f12 Mon Sep 17 00:00:00 2001

From: Beniamino Galvani <bgalvani@redhat.com>

Date: Thu, 21 Feb 2019 16:18:48 +0100

Subject: [PATCH] device: do ARP announcements only after masters have a slave

Delay ARP announcements for masters until the first interfaces gets

enslaved. There is no point in doing it before as the ARP packets

would be dropped in most cases; also, if the first slave is added when

we already started announcing, the MAC of the master is going to

change and so the remaining ARPs will have a wrong "sender mac

address" field.

https://bugzilla.redhat.com/show_bug.cgi?id=1678796

https://github.com/NetworkManager/NetworkManager/pull/301

(cherry picked from commit de1022285a6c09763d878cf60ef7e200343ae373)

---

 src/devices/nm-device.c | 38 +++++++++++++++++++++++++++++++++++---

 1 file changed, 35 insertions(+), 3 deletions(-)

diff --git a/src/devices/nm-device.c b/src/devices/nm-device.c

index a81541c87..a150442d3 100644

--- a/src/devices/nm-device.c

+++ b/src/devices/nm-device.c

@@ -2849,6 +2849,7 @@ find_slave_info (NMDevice *self, NMDevice *slave)

 static gboolean

 nm_device_master_enslave_slave (NMDevice *self, NMDevice *slave, NMConnection *connection)

 {

+	NMDevicePrivate *priv;

 	SlaveInfo *info;

 	gboolean success = FALSE;

 	gboolean configure;

@@ -2857,6 +2858,7 @@ nm_device_master_enslave_slave (NMDevice *self, NMDevice *slave, NMConnection *c

 	g_return_val_if_fail (slave != NULL, FALSE);

 	g_return_val_if_fail (NM_DEVICE_GET_CLASS (self)->enslave_slave != NULL, FALSE);

+	priv = NM_DEVICE_GET_PRIVATE (self);

 	info = find_slave_info (self, slave);

 	if (!info)

 		return FALSE;

@@ -2879,15 +2881,20 @@ nm_device_master_enslave_slave (NMDevice *self, NMDevice *slave, NMConnection *c

 	 */

 	nm_device_update_hw_address (self);

+	/* Send ARP announcements if did not yet and have addresses. */

+	if (   priv->ip4_state == IP_DONE

+	    && !priv->acd.announcing)

+		nm_device_arp_announce (self);

+

 	/* Restart IP configuration if we're waiting for slaves.  Do this

 	 * after updating the hardware address as IP config may need the

 	 * new address.

 	 */

 	if (success) {

-		if (NM_DEVICE_GET_PRIVATE (self)->ip4_state == IP_WAIT)

+		if (priv->ip4_state == IP_WAIT)

 			nm_device_activate_stage3_ip4_start (self);

-		if (NM_DEVICE_GET_PRIVATE (self)->ip6_state == IP_WAIT)

+		if (priv->ip6_state == IP_WAIT)

 			nm_device_activate_stage3_ip6_start (self);

 	}

@@ -9795,6 +9802,7 @@ activate_stage5_ip4_config_result (NMDevice *self)

 	const char *method;

 	NMConnection *connection;

 	int ip_ifindex;

+	gboolean do_announce = FALSE;

 	req = nm_device_get_act_request (self);

 	g_assert (req);

@@ -9840,7 +9848,31 @@ activate_stage5_ip4_config_result (NMDevice *self)

 		                           NULL, NULL, NULL);

 	}

-	nm_device_arp_announce (self);

+	/* Send ARP announcements */

+

+	if (nm_device_is_master (self)) {

+		CList *iter;

+		SlaveInfo *info;

+

+		/* Skip announcement if there are no device enslaved, for two reasons:

+		 * 1) the master has a temporary MAC address until the first slave comes

+		 * 2) announcements are going to be dropped anyway without slaves

+		 */

+		do_announce = FALSE;

+

+		c_list_for_each (iter, &priv->slaves) {

+			info = c_list_entry (iter, SlaveInfo, lst_slave);

+			if (info->slave_is_enslaved) {

+				do_announce = TRUE;

+				break;

+			}

+		}

+	} else

+		do_announce = TRUE;

+

+	if (do_announce)

+		nm_device_arp_announce (self);

+

 	nm_device_remove_pending_action (self, NM_PENDING_ACTION_DHCP4, FALSE);

 	/* Enter the IP_CHECK state if this is the first method to complete */

-- 

2.20.1