[PATCH v2] net:bonding:support balance-alb interface with vlan to bridge

[Sun Shouxin <sunshouxin@chinatelecom.cn>]

In my test, balance-alb bonding with two slaves eth0 and eth1,
and then Bond0.150 is created with vlan id attached bond0.
After adding bond0.150 into one linux bridge, I noted that Bond0,
bond0.150 and  bridge were assigned to the same MAC as eth0.
Once bond0.150 receives a packet whose dest IP is bridge's
and dest MAC is eth1's, the linux bridge will not match
eth1's MAC entry in FDB, and not handle it as expected.
The patch fix the issue, and diagram as below:

eth1(mac:eth1_mac)--bond0(balance-alb,mac:eth0_mac)--eth0(mac:eth0_mac)
                      |
                   bond0.150(mac:eth0_mac)
                      |
                   bridge(ip:br_ip, mac:eth0_mac)--other port

Suggested-by: Hu Yadi <huyd12@chinatelecom.cn>
Signed-off-by: Sun Shouxin <sunshouxin@chinatelecom.cn>
---

changelog:
v1->v2:
  -declare variabls in reverse xmas tree order
  -delete {}
  -add explanation in commit message
---
 drivers/net/bonding/bond_alb.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index 007d43e46dcb..60cb9a0225aa 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -653,6 +653,7 @@ static struct slave *rlb_choose_channel(struct sk_buff *skb,
 static struct slave *rlb_arp_xmit(struct sk_buff *skb, struct bonding *bond)
 {
 	struct slave *tx_slave = NULL;
+	struct net_device *dev;
 	struct arp_pkt *arp;
 
 	if (!pskb_network_may_pull(skb, sizeof(*arp)))
@@ -665,6 +666,12 @@ static struct slave *rlb_arp_xmit(struct sk_buff *skb, struct bonding *bond)
 	if (!bond_slave_has_mac_rx(bond, arp->mac_src))
 		return NULL;
 
+	dev = ip_dev_find(dev_net(bond->dev), arp->ip_src);
+	if (dev) {
+		if (netif_is_bridge_master(dev))
+			return NULL;
+	}
+
 	if (arp->op_code == htons(ARPOP_REPLY)) {
 		/* the arp must be sent on the selected rx channel */
 		tx_slave = rlb_choose_channel(skb, bond, arp);
-- 
2.27.0