From b00589af3b04736376f24625ab0b394642e89e29 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Linus=20L=C3=BCssing?= Date: Thu, 1 Aug 2013 01:06:20 +0200 Subject: bridge: disable snooping if there is no querier MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If there is no querier on a link then we won't get periodic reports and therefore won't be able to learn about multicast listeners behind ports, potentially leading to lost multicast packets, especially for multicast listeners that joined before the creation of the bridge. These lost multicast packets can appear since c5c23260594 ("bridge: Add multicast_querier toggle and disable queries by default") in particular. With this patch we are flooding multicast packets if our querier is disabled and if we didn't detect any other querier. A grace period of the Maximum Response Delay of the querier is added to give multicast responses enough time to arrive and to be learned from before disabling the flooding behaviour again. Signed-off-by: Linus Lüssing Signed-off-by: David S. Miller --- net/bridge/br_multicast.c | 39 ++++++++++++++++++++++++++++++--------- 1 file changed, 30 insertions(+), 9 deletions(-) (limited to 'net/bridge/br_multicast.c') diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 4b99c9a27044..61c5e819380e 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1014,6 +1014,16 @@ static int br_ip6_multicast_mld2_report(struct net_bridge *br, } #endif +static void br_multicast_update_querier_timer(struct net_bridge *br, + unsigned long max_delay) +{ + if (!timer_pending(&br->multicast_querier_timer)) + br->multicast_querier_delay_time = jiffies + max_delay; + + mod_timer(&br->multicast_querier_timer, + jiffies + br->multicast_querier_interval); +} + /* * Add port to router_list * list is maintained ordered by pointer value @@ -1064,11 +1074,11 @@ timer: static void br_multicast_query_received(struct net_bridge *br, struct net_bridge_port *port, - int saddr) + int saddr, + unsigned long max_delay) { if (saddr) - mod_timer(&br->multicast_querier_timer, - jiffies + br->multicast_querier_interval); + br_multicast_update_querier_timer(br, max_delay); else if (timer_pending(&br->multicast_querier_timer)) return; @@ -1096,8 +1106,6 @@ static int br_ip4_multicast_query(struct net_bridge *br, (port && port->state == BR_STATE_DISABLED)) goto out; - br_multicast_query_received(br, port, !!iph->saddr); - group = ih->group; if (skb->len == sizeof(*ih)) { @@ -1121,6 +1129,8 @@ static int br_ip4_multicast_query(struct net_bridge *br, IGMPV3_MRC(ih3->code) * (HZ / IGMP_TIMER_SCALE) : 1; } + br_multicast_query_received(br, port, !!iph->saddr, max_delay); + if (!group) goto out; @@ -1176,8 +1186,6 @@ static int br_ip6_multicast_query(struct net_bridge *br, (port && port->state == BR_STATE_DISABLED)) goto out; - br_multicast_query_received(br, port, !ipv6_addr_any(&ip6h->saddr)); - if (skb->len == sizeof(*mld)) { if (!pskb_may_pull(skb, sizeof(*mld))) { err = -EINVAL; @@ -1198,6 +1206,9 @@ static int br_ip6_multicast_query(struct net_bridge *br, max_delay = mld2q->mld2q_mrc ? MLDV2_MRC(ntohs(mld2q->mld2q_mrc)) : 1; } + br_multicast_query_received(br, port, !ipv6_addr_any(&ip6h->saddr), + max_delay); + if (!group) goto out; @@ -1643,6 +1654,8 @@ void br_multicast_init(struct net_bridge *br) br->multicast_querier_interval = 255 * HZ; br->multicast_membership_interval = 260 * HZ; + br->multicast_querier_delay_time = 0; + spin_lock_init(&br->multicast_lock); setup_timer(&br->multicast_router_timer, br_multicast_local_router_expired, 0); @@ -1831,6 +1844,8 @@ unlock: int br_multicast_set_querier(struct net_bridge *br, unsigned long val) { + unsigned long max_delay; + val = !!val; spin_lock_bh(&br->multicast_lock); @@ -1838,8 +1853,14 @@ int br_multicast_set_querier(struct net_bridge *br, unsigned long val) goto unlock; br->multicast_querier = val; - if (val) - br_multicast_start_querier(br); + if (!val) + goto unlock; + + max_delay = br->multicast_query_response_interval; + if (!timer_pending(&br->multicast_querier_timer)) + br->multicast_querier_delay_time = jiffies + max_delay; + + br_multicast_start_querier(br); unlock: spin_unlock_bh(&br->multicast_lock); -- cgit v1.2.3