From 9f00b2e7cf241fa389733d41b615efdaa2cb0f5b Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Tue, 21 May 2013 21:52:55 +0000 Subject: [PATCH] bridge: only expire the mdb entry when query is received Currently we arm the expire timer when the mdb entry is added, however, this causes problem when there is no querier sent out after that. So we should only arm the timer when a corresponding query is received, as suggested by Herbert. And he also mentioned "if there is no querier then group subscriptions shouldn't expire. There has to be at least one querier in the network for this thing to work. Otherwise it just degenerates into a non-snooping switch, which is OK." Cc: Herbert Xu Cc: Stephen Hemminger Cc: "David S. Miller" Cc: Adam Baker Signed-off-by: Cong Wang Acked-by: Herbert Xu Signed-off-by: David S. Miller --- net/bridge/br_multicast.c | 39 ++++++++++++--------------------------- net/bridge/br_private.h | 1 + 2 files changed, 13 insertions(+), 27 deletions(-) diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 247514793101..40bda804fbd9 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -617,8 +617,6 @@ struct net_bridge_mdb_entry *br_multicast_new_group(struct net_bridge *br, mp->br = br; mp->addr = *group; - setup_timer(&mp->timer, br_multicast_group_expired, - (unsigned long)mp); hlist_add_head_rcu(&mp->hlist[mdb->ver], &mdb->mhash[hash]); mdb->size++; @@ -656,7 +654,6 @@ static int br_multicast_add_group(struct net_bridge *br, struct net_bridge_mdb_entry *mp; struct net_bridge_port_group *p; struct net_bridge_port_group __rcu **pp; - unsigned long now = jiffies; int err; spin_lock(&br->multicast_lock); @@ -671,7 +668,6 @@ static int br_multicast_add_group(struct net_bridge *br, if (!port) { mp->mglist = true; - mod_timer(&mp->timer, now + br->multicast_membership_interval); goto out; } @@ -679,7 +675,7 @@ static int br_multicast_add_group(struct net_bridge *br, (p = mlock_dereference(*pp, br)) != NULL; pp = &p->next) { if (p->port == port) - goto found; + goto out; if ((unsigned long)p->port < (unsigned long)port) break; } @@ -690,8 +686,6 @@ static int br_multicast_add_group(struct net_bridge *br, rcu_assign_pointer(*pp, p); br_mdb_notify(br->dev, port, group, RTM_NEWMDB); -found: - mod_timer(&p->timer, now + br->multicast_membership_interval); out: err = 0; @@ -1131,6 +1125,10 @@ static int br_ip4_multicast_query(struct net_bridge *br, if (!mp) goto out; + setup_timer(&mp->timer, br_multicast_group_expired, (unsigned long)mp); + mod_timer(&mp->timer, now + br->multicast_membership_interval); + mp->timer_armed = true; + max_delay *= br->multicast_last_member_count; if (mp->mglist && @@ -1205,6 +1203,10 @@ static int br_ip6_multicast_query(struct net_bridge *br, if (!mp) goto out; + setup_timer(&mp->timer, br_multicast_group_expired, (unsigned long)mp); + mod_timer(&mp->timer, now + br->multicast_membership_interval); + mp->timer_armed = true; + max_delay *= br->multicast_last_member_count; if (mp->mglist && (timer_pending(&mp->timer) ? @@ -1263,7 +1265,7 @@ static void br_multicast_leave_group(struct net_bridge *br, call_rcu_bh(&p->rcu, br_multicast_free_pg); br_mdb_notify(br->dev, port, group, RTM_DELMDB); - if (!mp->ports && !mp->mglist && + if (!mp->ports && !mp->mglist && mp->timer_armed && netif_running(br->dev)) mod_timer(&mp->timer, jiffies); } @@ -1275,30 +1277,12 @@ static void br_multicast_leave_group(struct net_bridge *br, br->multicast_last_member_interval; if (!port) { - if (mp->mglist && + if (mp->mglist && mp->timer_armed && (timer_pending(&mp->timer) ? time_after(mp->timer.expires, time) : try_to_del_timer_sync(&mp->timer) >= 0)) { mod_timer(&mp->timer, time); } - - goto out; - } - - for (p = mlock_dereference(mp->ports, br); - p != NULL; - p = mlock_dereference(p->next, br)) { - if (p->port != port) - continue; - - if (!hlist_unhashed(&p->mglist) && - (timer_pending(&p->timer) ? - time_after(p->timer.expires, time) : - try_to_del_timer_sync(&p->timer) >= 0)) { - mod_timer(&p->timer, time); - } - - break; } out: @@ -1674,6 +1658,7 @@ void br_multicast_stop(struct net_bridge *br) hlist_for_each_entry_safe(mp, n, &mdb->mhash[i], hlist[ver]) { del_timer(&mp->timer); + mp->timer_armed = false; call_rcu_bh(&mp->rcu, br_multicast_free_group); } } diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index e260710a01d4..1b0ac95a5c37 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -112,6 +112,7 @@ struct net_bridge_mdb_entry struct timer_list timer; struct br_ip addr; bool mglist; + bool timer_armed; }; struct net_bridge_mdb_htable