mcast-snoop: Add support to control Reports forwarding

The RFC4541 section 2.1.1 item 1 allows the snooping switch
to provide an administrative control to allow Report messages
to be flooded to ports not connected to multicast routers.

Signed-off-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>

2 files changed, 42 insertions, 1 deletions

diff --git a/lib/mcast-snooping.c b/lib/mcast-snooping.c
index 87b6b0c6d..6fe3890c7 100644
--- a/lib/mcast-snooping.c
+++ b/lib/mcast-snooping.c
@@ -160,6 +160,7 @@ mcast_snooping_create(void)
     list_init(&ms->group_lru);
     list_init(&ms->mrouter_lru);
     list_init(&ms->fport_list);
+    list_init(&ms->rport_list);
     ms->secret = random_uint32();
     ms->idle_time = MCAST_ENTRY_DEFAULT_IDLE_TIME;
     ms->max_entries = MCAST_DEFAULT_MAX_ENTRIES;
@@ -423,6 +424,13 @@ mcast_snooping_leave_group(struct mcast_snooping *ms, ovs_be32 ip4,
 {
     struct mcast_group *grp;
 
+    /* Ports flagged to forward Reports usually have more
+     * than one host behind it, so don't leave the group
+     * on the first message and just let it expire */
+    if (mcast_snooping_port_lookup(&ms->rport_list, port)) {
+        return false;
+    }
+
     grp = mcast_snooping_lookup(ms, ip4, vlan);
     if (grp && mcast_group_delete_bundle(ms, grp, port)) {
         ms->need_revalidate = true;
@@ -589,6 +597,25 @@ mcast_snooping_set_port_flood(struct mcast_snooping *ms, void *port,
     }
 }
 
+/* Flood Reports ports. */
+
+void
+mcast_snooping_set_port_flood_reports(struct mcast_snooping *ms, void *port,
+                                      bool flood)
+    OVS_REQ_WRLOCK(ms->rwlock)
+{
+    struct mcast_port_bundle *pbundle;
+
+    pbundle = mcast_snooping_port_lookup(&ms->rport_list, port);
+    if (flood && !pbundle) {
+        mcast_snooping_add_port(&ms->rport_list, port);
+        ms->need_revalidate = true;
+    } else if (!flood && pbundle) {
+        mcast_snooping_flush_port(pbundle);
+        ms->need_revalidate = true;
+    }
+}
+
 /* Run and flush. */
 
 static void
@@ -636,13 +663,20 @@ mcast_snooping_flush__(struct mcast_snooping *ms)
 
     hmap_shrink(&ms->table);
 
+    /* flush multicast routers */
     while (mrouter_get_lru(ms, &mrouter)) {
         mcast_snooping_flush_mrouter(mrouter);
     }
 
+    /* flush flood ports */
     while (mcast_snooping_port_get(&ms->fport_list, &pbundle)) {
         mcast_snooping_flush_port(pbundle);
     }
+
+    /* flush flood report ports */
+    while (mcast_snooping_port_get(&ms->rport_list, &pbundle)) {
+        mcast_snooping_flush_port(pbundle);
+    }
 }
 
 void
diff --git a/lib/mcast-snooping.h b/lib/mcast-snooping.h
index c23ed6be9..979b2aa60 100644
--- a/lib/mcast-snooping.h
+++ b/lib/mcast-snooping.h
@@ -87,7 +87,7 @@ struct mcast_mrouter_bundle {
     void *port OVS_GUARDED;
 };
 
-/* The bundle to send multicast traffic.
+/* The bundle to send multicast traffic or Reports.
  * Guarded by owning 'mcast_snooping''s rwlock */
 struct mcast_port_bundle {
     /* Node in parent struct mcast_snooping. */
@@ -117,6 +117,10 @@ struct mcast_snooping {
      * packets in no special order. */
     struct ovs_list fport_list OVS_GUARDED;
 
+    /* Contains struct mcast_port_bundle to forward Reports in
+     * no special order. */
+    struct ovs_list rport_list OVS_GUARDED;
+
     /* Secret for randomizing hash table. */
     uint32_t secret;
 
@@ -163,6 +167,9 @@ mcast_snooping_set_flood_unreg(struct mcast_snooping *ms, bool enable)
 void mcast_snooping_set_port_flood(struct mcast_snooping *ms, void *port,
                                    bool flood)
     OVS_REQ_WRLOCK(ms->rwlock);
+void mcast_snooping_set_port_flood_reports(struct mcast_snooping *ms,
+                                           void *port, bool flood)
+    OVS_REQ_WRLOCK(ms->rwlock);
 
 /* Lookup. */
 struct mcast_group *