bonding: allow arp_ip_targets on separate vlans to use arp validation

This allows a bond device to specify an arp_ip_target as a host that is
not on the same vlan as the base bond device and still use arp
validation.  A configuration like this, now works:

BONDING_OPTS="mode=active-backup arp_interval=1000 arp_ip_target=10.0.100.1 arp_validate=3"

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth1: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 qlen 1000
    link/ether 00:13:21:be:33:e9 brd ff:ff:ff:ff:ff:ff
3: eth0: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 qlen 1000
    link/ether 00:13:21:be:33:e9 brd ff:ff:ff:ff:ff:ff
8: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue
    link/ether 00:13:21:be:33:e9 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::213:21ff:febe:33e9/64 scope link
       valid_lft forever preferred_lft forever
9: bond0.100@bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue
    link/ether 00:13:21:be:33:e9 brd ff:ff:ff:ff:ff:ff
    inet 10.0.100.2/24 brd 10.0.100.255 scope global bond0.100
    inet6 fe80::213:21ff:febe:33e9/64 scope link
       valid_lft forever preferred_lft forever

Ethernet Channel Bonding Driver: v3.6.0 (September 26, 2009)

Bonding Mode: fault-tolerance (active-backup)
Primary Slave: None
Currently Active Slave: eth1
MII Status: up
MII Polling Interval (ms): 0
Up Delay (ms): 0
Down Delay (ms): 0
ARP Polling Interval (ms): 1000
ARP IP target/s (n.n.n.n form): 10.0.100.1

Slave Interface: eth1
MII Status: up
Link Failure Count: 1
Permanent HW addr: 00:40:05:30:ff:30

Slave Interface: eth0
MII Status: up
Link Failure Count: 0
Permanent HW addr: 00:13:21:be:33:e9
Signed-off-by: NAndy Gospodarek <andy@greyhouse.net>
Signed-off-by: NJay Vosburgh <fubar@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_main.c

@@ -2615,6 +2615,17 @@ static int bond_arp_rcv(struct sk_buff *skb, struct net_device *dev, struct pack
 	unsigned char *arp_ptr;
 	__be32 sip, tip;
 
+	if (dev->priv_flags & IFF_802_1Q_VLAN) {
+		/*
+		 * When using VLANS and bonding, dev and oriv_dev may be
+		 * incorrect if the physical interface supports VLAN
+		 * acceleration.  With this change ARP validation now
+		 * works for hosts only reachable on the VLAN interface.
+		 */
+		dev = vlan_dev_real_dev(dev);
+		orig_dev = dev_get_by_index_rcu(dev_net(skb->dev),skb->skb_iif);
+	}
+
 	if (!(dev->priv_flags & IFF_BONDING) || !(dev->flags & IFF_MASTER))
 		goto out;
 

net/8021q/vlan_core.c

@@ -14,6 +14,7 @@ int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 	if (skb_bond_should_drop(skb))
 		goto drop;
 
+	skb->skb_iif = skb->dev->ifindex;
 	__vlan_hwaccel_put_tag(skb, vlan_tci);
 	skb->dev = vlan_group_get_device(grp, vlan_tci & VLAN_VID_MASK);
 
@@ -85,6 +86,7 @@ vlan_gro_common(struct napi_struct *napi, struct vlan_group *grp,
 	if (skb_bond_should_drop(skb))
 		goto drop;
 
+	skb->skb_iif = skb->dev->ifindex;
 	__vlan_hwaccel_put_tag(skb, vlan_tci);
 	skb->dev = vlan_group_get_device(grp, vlan_tci & VLAN_VID_MASK);
 

net/core/dev.c

@@ -2495,12 +2495,26 @@ int netif_receive_skb(struct sk_buff *skb)
 	if (!skb)
 		goto out;
 
+	/*
+	 * Make sure frames received on VLAN interfaces stacked on
+	 * bonding interfaces still make their way to any base bonding
+	 * device that may have registered for a specific ptype.  The
+	 * handler may have to adjust skb->dev and orig_dev.
+	 *
+	 * null_or_orig can be overloaded since it will not be set when
+	 * using VLANs on top of bonding.  Putting it here prevents
+	 * disturbing the ptype_all handlers above.
+	 */
+	if ((skb->dev->priv_flags & IFF_802_1Q_VLAN) &&
+	    (vlan_dev_real_dev(skb->dev)->priv_flags & IFF_BONDING)) {
+		null_or_orig = vlan_dev_real_dev(skb->dev);
+	}
+
 	type = skb->protocol;
 	list_for_each_entry_rcu(ptype,
 			&ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
-		if (ptype->type == type &&
-		    (ptype->dev == null_or_orig || ptype->dev == skb->dev ||
-		     ptype->dev == orig_dev)) {
+		if (ptype->type == type && (ptype->dev == null_or_orig ||
+		     ptype->dev == skb->dev || ptype->dev == orig_dev)) {
 			if (pt_prev)
 				ret = deliver_skb(skb, pt_prev, orig_dev);
 			pt_prev = ptype;