X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=vswitchd%2Fbridge.c;h=61813bb4cb41e33b84f0c704d25ed3dd0eeb5038;hb=5d0ae1387c968859b390dba9768ce44ac788405b;hp=8314c5392bd2b73c8e332bc1aab336ac551c045d;hpb=9d82ec478d52edfddd215dff1b0659ed7508b365;p=openvswitch

diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c
index 8314c539..61813bb4 100644
--- a/vswitchd/bridge.c
+++ b/vswitchd/bridge.c
@@ -2269,12 +2269,17 @@ update_learning_table(struct bridge *br, const flow_t *flow, int vlan,
     }
 }
 
+/* A VM broadcasts a gratuitous ARP to indicate that it has resumed after
+ * migration.  Older Citrix-patched Linux DomU used gratuitous ARP replies to
+ * indicate this; newer upstream kernels use gratuitous ARP requests. */
 static bool
-is_bcast_arp_reply(const flow_t *flow)
+is_gratuitous_arp(const flow_t *flow)
 {
     return (flow->dl_type == htons(ETH_TYPE_ARP)
-            && flow->nw_proto == ARP_OP_REPLY
-            && eth_addr_is_broadcast(flow->dl_dst));
+            && eth_addr_is_broadcast(flow->dl_dst)
+            && (flow->nw_proto == ARP_OP_REPLY
+                || (flow->nw_proto == ARP_OP_REQUEST
+                    && flow->nw_src == flow->nw_dst)));
 }
 
 /* Determines whether packets in 'flow' within 'br' should be forwarded or
@@ -2366,11 +2371,11 @@ is_admissible(struct bridge *br, const flow_t *flow, bool have_packet,
 
         /* 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.  Broadcast ARP replies are an exception
+         * it back on the other.  Gratuitous ARP packets are an exception
          * to this rule: the host has moved to another switch. */
         src_idx = mac_learning_lookup(br->ml, flow->dl_src, vlan);
         if (src_idx != -1 && src_idx != in_port->port_idx &&
-            !is_bcast_arp_reply(flow)) {
+            !is_gratuitous_arp(flow)) {
                 return false;
         }
     }