mcast-snooping: Flush flood and report ports when deleting interfaces.

When a configuration change triggers an interface destruction/creation
(like for example, setting ofport_request), a port object may still be
referenced as a fport or a rport in the mdb.

Before the fix, when flooding multicast traffic:
bridge("br0")
-------------
 0. priority 32768
    NORMAL
     -> forwarding to mcast group port
     >> mcast flood port is unknown, dropping
     -> mcast flood port is input port, dropping
     -> forwarding to mcast flood port

Before the fix, when flooding igmp report traffic:
bridge("br0")
-------------
 0. priority 32768
    NORMAL
     >> mcast port is unknown, dropping the report
     -> forwarding report to mcast flagged port
     -> mcast port is input port, dropping the Report
     -> forwarding report to mcast flagged port

Add relevant cleanup and update unit tests.

Fixes: 4fbbf86 ("mcast-snooping: Flush ports mdb when VLAN configuration changed.")
Acked-by: Paolo Valerio <pvalerio@redhat.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Simon Horman <horms@ovn.org>

lib/mcast-snooping.c

@@ -946,8 +946,9 @@ mcast_snooping_wait(struct mcast_snooping *ms)
 void
 mcast_snooping_flush_bundle(struct mcast_snooping *ms, void *port)
 {
-    struct mcast_group *g;
     struct mcast_mrouter_bundle *m;
+    struct mcast_port_bundle *p;
+    struct mcast_group *g;
 
     if (!mcast_snooping_enabled(ms)) {
         return;
@@ -971,5 +972,19 @@ mcast_snooping_flush_bundle(struct mcast_snooping *ms, void *port)
         }
     }
 
+    LIST_FOR_EACH_SAFE (p, node, &ms->fport_list) {
+        if (p->port == port) {
+            mcast_snooping_flush_port(p);
+            ms->need_revalidate = true;
+        }
+    }
+
+    LIST_FOR_EACH_SAFE (p, node, &ms->rport_list) {
+        if (p->port == port) {
+            mcast_snooping_flush_port(p);
+            ms->need_revalidate = true;
+        }
+    }
+
     ovs_rwlock_unlock(&ms->rwlock);
 }

tests/mcast-snooping.at

@@ -207,6 +207,26 @@ Megaflow: recirc_id=0,eth,udp,in_port=3,dl_src=aa:55:aa:55:00:ff,dl_dst=01:00:5e
 Datapath actions: 1,2
 ])
 
+# Change p2 ofport to force a ofbundle change and check that the mdb contains
+# no stale port.
+AT_CHECK([ovs-vsctl set interface p2 ofport_request=4])
+
+AT_CHECK([ovs-appctl ofproto/trace "in_port(3),eth(src=aa:55:aa:55:00:ff,dst=01:00:5e:01:01:01),eth_type(0x0800),ipv4(src=10.0.0.1,dst=224.1.1.1,proto=17,tos=0,ttl=64,frag=no),udp(src=0,dst=8000)"], [0], [dnl
+Flow: udp,in_port=3,vlan_tci=0x0000,dl_src=aa:55:aa:55:00:ff,dl_dst=01:00:5e:01:01:01,nw_src=10.0.0.1,nw_dst=224.1.1.1,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=0,tp_dst=8000
+
+bridge("br0")
+-------------
+ 0. priority 32768
+    NORMAL
+     -> forwarding to mcast group port
+     -> mcast flood port is input port, dropping
+     -> forwarding to mcast flood port
+
+Final flow: unchanged
+Megaflow: recirc_id=0,eth,udp,in_port=3,dl_src=aa:55:aa:55:00:ff,dl_dst=01:00:5e:01:01:01,nw_dst=224.1.1.1,nw_frag=no
+Datapath actions: 1,2
+])
+
 OVS_VSWITCHD_STOP
 AT_CLEANUP
 
@@ -381,6 +401,28 @@ This flow is handled by the userspace slow path because it:
   - Uses action(s) not supported by datapath.
 ])
 
+# Change p2 ofport to force a ofbundle change and check that the mdb contains
+# no stale port.
+AT_CHECK([ovs-vsctl set interface p3 ofport_request=4])
+
+AT_CHECK([ovs-appctl ofproto/trace "in_port(1)" '01005E010101000C29A027A108004500001C000100004002CBAEAC10221EE001010112140CE9E0010101'], [0], [dnl
+Flow: ip,in_port=1,vlan_tci=0x0000,dl_src=00:0c:29:a0:27:a1,dl_dst=01:00:5e:01:01:01,nw_src=172.16.34.30,nw_dst=224.1.1.1,nw_proto=2,nw_tos=0,nw_ecn=0,nw_ttl=64,nw_frag=no,tp_src=18,tp_dst=20
+
+bridge("br0")
+-------------
+ 0. priority 32768
+    NORMAL
+     -> forwarding report to mcast flagged port
+     -> mcast port is input port, dropping the Report
+     -> forwarding report to mcast flagged port
+
+Final flow: unchanged
+Megaflow: recirc_id=0,eth,ip,in_port=1,dl_src=00:0c:29:a0:27:a1,dl_dst=01:00:5e:01:01:01,nw_proto=2,nw_frag=no
+Datapath actions: 2,3
+This flow is handled by the userspace slow path because it:
+  - Uses action(s) not supported by datapath.
+])
+
 OVS_VSWITCHD_STOP
 AT_CLEANUP