bonding: make bond_arp_send_all use upper device list

Currently, bond_arp_send_all() is aware only of vlans, which breaks
configurations like bond <- bridge (or any other 'upper' device) with IP
(which is quite a common scenario for virt setups).

To fix this we convert the bond_arp_send_all() to first verify if the rt
device is the bond itself, and if not - to go through its list of upper
vlans and their respectiv upper devices (if the vlan's upper device matches
- tag the packet), if still not found - go through all of our upper list
devices to see if any of them match the route device for the target. If the
match is a vlan device - we also save its vlan_id and tag it in
bond_arp_send().

Also, clean the function a bit to be more readable.

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

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 7407e65f5d96c8012ca439c67e0ab7f9492a6d8b..28f4ad0dffbacf67e2418a53e82865eec215f021 100644 (file)
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2444,30 +2444,16 @@ static void bond_arp_send(struct net_device *slave_dev, int arp_op, __be32 dest_
 
 static void bond_arp_send_all(struct bonding *bond, struct slave *slave)
 {
-       int i, vlan_id;
-       __be32 *targets = bond->params.arp_targets;
-       struct vlan_entry *vlan;
-       struct net_device *vlan_dev = NULL;
+       struct net_device *upper, *vlan_upper;
+       struct list_head *iter, *vlan_iter;
        struct rtable *rt;
+       __be32 *targets = bond->params.arp_targets, addr;
+       int i, vlan_id;
 
-       for (i = 0; (i < BOND_MAX_ARP_TARGETS); i++) {
-               __be32 addr;
-               if (!targets[i])
-                       break;
+       for (i = 0; i < BOND_MAX_ARP_TARGETS && targets[i]; i++) {
                pr_debug("basa: target %pI4\n", &targets[i]);
-               if (!bond_vlan_used(bond)) {
-                       pr_debug("basa: empty vlan: arp_send\n");
-                       addr = bond_confirm_addr(bond->dev, targets[i], 0);
-                       bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
-                                     addr, 0);
-                       continue;
-               }
 
-               /*
-                * If VLANs are configured, we do a route lookup to
-                * determine which VLAN interface would be used, so we
-                * can tag the ARP with the proper VLAN tag.
-                */
+               /* Find out through which dev should the packet go */
                rt = ip_route_output(dev_net(bond->dev), targets[i], 0,
                                     RTO_ONLINK, 0);
                if (IS_ERR(rt)) {
@@ -2478,47 +2464,61 @@ static void bond_arp_send_all(struct bonding *bond, struct slave *slave)
                        continue;
                }
 
-               /*
-                * This target is not on a VLAN
-                */
-               if (rt->dst.dev == bond->dev) {
-                       ip_rt_put(rt);
-                       pr_debug("basa: rtdev == bond->dev: arp_send\n");
-                       addr = bond_confirm_addr(bond->dev, targets[i], 0);
-                       bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
-                                     addr, 0);
-                       continue;
-               }
-
                vlan_id = 0;
-               list_for_each_entry(vlan, &bond->vlan_list, vlan_list) {
-                       rcu_read_lock();
-                       vlan_dev = __vlan_find_dev_deep(bond->dev,
-                                                       htons(ETH_P_8021Q),
-                                                       vlan->vlan_id);
-                       rcu_read_unlock();
-                       if (vlan_dev == rt->dst.dev) {
-                               vlan_id = vlan->vlan_id;
-                               pr_debug("basa: vlan match on %s %d\n",
-                                      vlan_dev->name, vlan_id);
-                               break;
+
+               /* bond device itself */
+               if (rt->dst.dev == bond->dev)
+                       goto found;
+
+               rcu_read_lock();
+               /* first we search only for vlan devices. for every vlan
+                * found we verify its upper dev list, searching for the
+                * rt->dst.dev. If found we save the tag of the vlan and
+                * proceed to send the packet.
+                *
+                * TODO: QinQ?
+                */
+               netdev_for_each_upper_dev_rcu(bond->dev, vlan_upper, vlan_iter) {
+                       if (!is_vlan_dev(vlan_upper))
+                               continue;
+                       netdev_for_each_upper_dev_rcu(vlan_upper, upper, iter) {
+                               if (upper == rt->dst.dev) {
+                                       vlan_id = vlan_dev_vlan_id(vlan_upper);
+                                       rcu_read_unlock();
+                                       goto found;
+                               }
                        }
                }
 
-               if (vlan_id && vlan_dev) {
-                       ip_rt_put(rt);
-                       addr = bond_confirm_addr(vlan_dev, targets[i], 0);
-                       bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
-                                     addr, vlan_id);
-                       continue;
+               /* if the device we're looking for is not on top of any of
+                * our upper vlans, then just search for any dev that
+                * matches, and in case it's a vlan - save the id
+                */
+               netdev_for_each_upper_dev_rcu(bond->dev, upper, iter) {
+                       if (upper == rt->dst.dev) {
+                               /* if it's a vlan - get its VID */
+                               if (is_vlan_dev(upper))
+                                       vlan_id = vlan_dev_vlan_id(upper);
+
+                               rcu_read_unlock();
+                               goto found;
+                       }
                }
+               rcu_read_unlock();
 
-               if (net_ratelimit()) {
+               /* Not our device - skip */
+               if (net_ratelimit())
                        pr_warning("%s: no path to arp_ip_target %pI4 via rt.dev %s\n",
                                   bond->dev->name, &targets[i],
                                   rt->dst.dev ? rt->dst.dev->name : "NULL");
-               }
                ip_rt_put(rt);
+               continue;
+
+found:
+               addr = bond_confirm_addr(rt->dst.dev, targets[i], 0);
+               ip_rt_put(rt);
+               bond_arp_send(slave->dev, ARPOP_REQUEST, targets[i],
+                             addr, vlan_id);
        }
 }