bond: Only drop packets that indicate moves on SLB bonds.

SLB bonds, for important reasons, drop most incoming packets that indicate
that a MAC has moved to the bond from another port.  These reasons do not
apply to other types of bonds, but until now OVS has still dropped them.

This fixes the problem.  It changes behavior of active-backup bonds and
stable bonds, neither of which has the same problem as SLB.  Behavior of
SLB bonds and TCP bonds in SLB fallback mode is unaffected.

Bug #7928.

diff --git a/lib/bond.c b/lib/bond.c
index 2b99b9acc5eb0c1a1f27503ceb33af62781324c8..90498f63b35d12991a59b8b7daba42cc10e873f1 100644 (file)
--- a/lib/bond.c
+++ b/lib/bond.c
@@ -575,9 +575,10 @@ bond_check_admissibility(struct bond *bond, const void *slave_,
         }
     }
 
-    /* Drop all packets which arrive on backup slaves.  This is similar to how
-     * Linux bonding handles active-backup bonds. */
-    if (bond->balance == BM_AB) {
+    switch (bond->balance) {
+    case BM_AB:
+        /* Drop all packets which arrive on backup slaves.  This is similar to
+         * how Linux bonding handles active-backup bonds. */
         *tags |= bond_get_active_slave_tag(bond);
         if (bond->active_slave != slave) {
             static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
@@ -587,14 +588,27 @@ bond_check_admissibility(struct bond *bond, const void *slave_,
                         slave->name, ETH_ADDR_ARGS(eth_dst));
             return BV_DROP;
         }
+        return BV_ACCEPT;
+
+    case BM_TCP:
+        /* TCP balancing has degraded to SLB (otherwise the
+         * bond->lacp_negotiated check above would have processed this).
+         *
+         * Fall through. */
+    case BM_SLB:
+        /* Drop all packets for which we have learned a different input port,
+         * because we probably sent the packet on one slave and got it back on
+         * the other.  Gratuitous ARP packets are an exception to this rule:
+         * the host has moved to another switch.  The exception to the
+         * exception is if we locked the learning table to avoid reflections on
+         * bond slaves. */
+        return BV_DROP_IF_MOVED;
+
+    case BM_STABLE:
+        return BV_ACCEPT;
     }
 
-    /* Drop all packets for which we have learned a different input port,
-     * because we probably sent the packet on one slave and got it back on the
-     * other.  Gratuitous ARP packets are an exception to this rule: the host
-     * has moved to another switch.  The exception to the exception is if we
-     * locked the learning table to avoid reflections on bond slaves. */
-    return BV_DROP_IF_MOVED;
+    NOT_REACHED();
 }
 
 /* Returns the slave (registered on 'bond' by bond_slave_register()) to which