bonding: Send ALB learning packets using the right source

ALB learning packets are currentlyalways sent using the slave mac
address for all vlans configured on top of bond.   This is not always
correct, as vlans may change their mac address.
This patch introduced a concept of strict matching where the
source of learning packets can either strictly match the address
passed in, or it can determine a more correct address to use.

There are 3 casese to consider:
  1) Switchover.  In this case, we have a new active slave and we need
     tell the switch about all addresses available on the slave.
  2) Monitor.  We'll periodically refresh learning info for all slaves.
     In this case, we refresh all addresses for current active, and just
     the slave address for other slaves.
  3) Teaching of disabled adddress.  This happens as part of the
     failover and in this case, we alwyas to use just the address
     provided.

CC: Jay Vosburgh <j.vosburgh@gmail.com>
CC: Veaceslav Falico <vfalico@gmail.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_alb.c

@@ -82,7 +82,8 @@ static inline struct arp_pkt *arp_pkt(const struct sk_buff *skb)
 }
 
 /* Forward declaration */
-static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[]);
+static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[],
+				      bool strict_match);
 static void rlb_purge_src_ip(struct bonding *bond, struct arp_pkt *arp);
 static void rlb_src_unlink(struct bonding *bond, u32 index);
 static void rlb_src_link(struct bonding *bond, u32 ip_src_hash,
@@ -459,7 +460,7 @@ static void rlb_teach_disabled_mac_on_primary(struct bonding *bond, u8 addr[])
 
 	bond->alb_info.rlb_promisc_timeout_counter = 0;
 
-	alb_send_learning_packets(bond->curr_active_slave, addr);
+	alb_send_learning_packets(bond->curr_active_slave, addr, true);
 }
 
 /* slave being removed should not be active at this point
@@ -1032,8 +1033,8 @@ static void alb_send_lp_vid(struct slave *slave, u8 mac_addr[],
 	dev_queue_xmit(skb);
 }
 
-
-static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[])
+static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[],
+				      bool strict_match)
 {
 	struct bonding *bond = bond_get_bond_by_slave(slave);
 	struct net_device *upper;
@@ -1045,10 +1046,19 @@ static void alb_send_learning_packets(struct slave *slave, u8 mac_addr[])
 	/* loop through vlans and send one packet for each */
 	rcu_read_lock();
 	netdev_for_each_all_upper_dev_rcu(bond->dev, upper, iter) {
-		if (is_vlan_dev(upper) && vlan_get_encap_level(upper) == 0)
-			alb_send_lp_vid(slave, mac_addr,
-					vlan_dev_vlan_proto(upper),
-					vlan_dev_vlan_id(upper));
+		if (is_vlan_dev(upper) && vlan_get_encap_level(upper) == 0) {
+			if (strict_match &&
+			    ether_addr_equal_64bits(mac_addr,
+						    upper->dev_addr)) {
+				alb_send_lp_vid(slave, mac_addr,
+						vlan_dev_vlan_proto(upper),
+						vlan_dev_vlan_id(upper));
+			} else if (!strict_match) {
+				alb_send_lp_vid(slave, upper->dev_addr,
+						vlan_dev_vlan_proto(upper),
+						vlan_dev_vlan_id(upper));
+			}
+		}
 	}
 	rcu_read_unlock();
 }
@@ -1108,7 +1118,7 @@ static void alb_fasten_mac_swap(struct bonding *bond, struct slave *slave1,
 
 	/* fasten the change in the switch */
 	if (SLAVE_IS_OK(slave1)) {
-		alb_send_learning_packets(slave1, slave1->dev->dev_addr);
+		alb_send_learning_packets(slave1, slave1->dev->dev_addr, false);
 		if (bond->alb_info.rlb_enabled) {
 			/* inform the clients that the mac address
 			 * has changed
@@ -1120,7 +1130,7 @@ static void alb_fasten_mac_swap(struct bonding *bond, struct slave *slave1,
 	}
 
 	if (SLAVE_IS_OK(slave2)) {
-		alb_send_learning_packets(slave2, slave2->dev->dev_addr);
+		alb_send_learning_packets(slave2, slave2->dev->dev_addr, false);
 		if (bond->alb_info.rlb_enabled) {
 			/* inform the clients that the mac address
 			 * has changed
@@ -1491,15 +1501,24 @@ void bond_alb_monitor(struct work_struct *work)
 
 	/* send learning packets */
 	if (bond_info->lp_counter >= BOND_ALB_LP_TICKS(bond)) {
+		bool strict_match;
+
 		/* change of curr_active_slave involves swapping of mac addresses.
 		 * in order to avoid this swapping from happening while
 		 * sending the learning packets, the curr_slave_lock must be held for
 		 * read.
 		 */
 		read_lock(&bond->curr_slave_lock);
 
-		bond_for_each_slave_rcu(bond, slave, iter)
-			alb_send_learning_packets(slave, slave->dev->dev_addr);
+		bond_for_each_slave_rcu(bond, slave, iter) {
+			/* If updating current_active, use all currently
+			 * user mac addreses (!strict_match).  Otherwise, only
+			 * use mac of the slave device.
+			 */
+			strict_match = (slave != bond->curr_active_slave);
+			alb_send_learning_packets(slave, slave->dev->dev_addr,
+						  strict_match);
+		}
 
 		read_unlock(&bond->curr_slave_lock);
 
@@ -1722,7 +1741,8 @@ void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave
 	} else {
 		/* set the new_slave to the bond mac address */
 		alb_set_slave_mac_addr(new_slave, bond->dev->dev_addr);
-		alb_send_learning_packets(new_slave, bond->dev->dev_addr);
+		alb_send_learning_packets(new_slave, bond->dev->dev_addr,
+					  false);
 	}
 
 	write_lock_bh(&bond->curr_slave_lock);
@@ -1765,7 +1785,8 @@ int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
 		alb_set_slave_mac_addr(bond->curr_active_slave, bond_dev->dev_addr);
 
 		read_lock(&bond->lock);
-		alb_send_learning_packets(bond->curr_active_slave, bond_dev->dev_addr);
+		alb_send_learning_packets(bond->curr_active_slave,
+					  bond_dev->dev_addr, false);
 		if (bond->alb_info.rlb_enabled) {
 			/* inform clients mac address has changed */
 			rlb_req_update_slave_clients(bond, bond->curr_active_slave);