bonding: send learning packets for vlans on slave

There was a regression at some point from the intended functionality of
commit f60c3704 ("bonding: Fix alb mode to only use first level
vlans.")

Given the return value vlan_get_encap_level() we need to store the nest
level of the bond device, and then compare the vlan's encap level to
this. Without this, this check always fails and learning packets are
never sent.

In addition, this same commit caused a regression in the behavior of
balance_alb, which requires learning packets be sent for all interfaces
using the slave's mac in order to load balance properly. For vlan's
that have not set a user mac, we can send after checking one bit.
Otherwise we need send the set mac, albeit defeating rx load balancing
for that vlan.
Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_alb.c

@@ -943,6 +943,10 @@ static void alb_send_lp_vid(struct slave *slave, u8 mac_addr[],
 	skb->priority = TC_PRIO_CONTROL;
 	skb->dev = slave->dev;
 
+	netdev_dbg(slave->bond->dev,
+		   "Send learning packet: dev %s mac %pM vlan %d\n",
+		   slave->dev->name, mac_addr, vid);
+
 	if (vid)
 		__vlan_hwaccel_put_tag(skb, vlan_proto, vid);
 
@@ -965,14 +969,13 @@ static int alb_upper_dev_walk(struct net_device *upper, void *_data)
 	u8 *mac_addr = data->mac_addr;
 	struct bond_vlan_tag *tags;
 
-	if (is_vlan_dev(upper) && vlan_get_encap_level(upper) == 0) {
-		if (strict_match &&
-		    ether_addr_equal_64bits(mac_addr,
-					    upper->dev_addr)) {
+	if (is_vlan_dev(upper) &&
+	    bond->nest_level == vlan_get_encap_level(upper) - 1) {
+		if (upper->addr_assign_type == NET_ADDR_STOLEN) {
 			alb_send_lp_vid(slave, mac_addr,
 					vlan_dev_vlan_proto(upper),
 					vlan_dev_vlan_id(upper));
-		} else if (!strict_match) {
+		} else {
 			alb_send_lp_vid(slave, upper->dev_addr,
 					vlan_dev_vlan_proto(upper),
 					vlan_dev_vlan_id(upper));

drivers/net/bonding/bond_main.c

@@ -1738,6 +1738,8 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev,
 	if (bond_mode_uses_xmit_hash(bond))
 		bond_update_slave_arr(bond, NULL);
 
+	bond->nest_level = dev_get_nest_level(bond_dev);
+
 	netdev_info(bond_dev, "Enslaving %s as %s interface with %s link\n",
 		    slave_dev->name,
 		    bond_is_active_slave(new_slave) ? "an active" : "a backup",

include/net/bonding.h

@@ -198,6 +198,7 @@ struct bonding {
 	struct   slave __rcu *primary_slave;
 	struct   bond_up_slave __rcu *slave_arr; /* Array of usable slaves */
 	bool     force_primary;
+	u32      nest_level;
 	s32      slave_cnt; /* never change this value outside the attach/detach wrappers */
 	int     (*recv_probe)(const struct sk_buff *, struct bonding *,
 			      struct slave *);