From 4effd28c1245303dce7fd290c501ac2c11052114 Mon Sep 17 00:00:00 2001 From: Linus Lüssing Date: Mon, 21 Jan 2019 07:26:27 +0100 Subject: bridge: join all-snoopers multicast address MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Next to snooping IGMP/MLD queries RFC4541, section 2.1.1.a) recommends to snoop multicast router advertisements to detect multicast routers. Multicast router advertisements are sent to an "all-snoopers" multicast address. To be able to receive them reliably, we need to join this group. Otherwise other snooping switches might refrain from forwarding these advertisements to us. Signed-off-by: Linus Lüssing Signed-off-by: David S. Miller --- net/bridge/br_multicast.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 71 insertions(+), 1 deletion(-) (limited to 'net/bridge') diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 156c4905639e..2366f4a2780e 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1780,6 +1780,68 @@ void br_multicast_init(struct net_bridge *br) INIT_HLIST_HEAD(&br->mdb_list); } +static void br_ip4_multicast_join_snoopers(struct net_bridge *br) +{ + struct in_device *in_dev = in_dev_get(br->dev); + + if (!in_dev) + return; + + ip_mc_inc_group(in_dev, htonl(INADDR_ALLSNOOPERS_GROUP)); + in_dev_put(in_dev); +} + +#if IS_ENABLED(CONFIG_IPV6) +static void br_ip6_multicast_join_snoopers(struct net_bridge *br) +{ + struct in6_addr addr; + + ipv6_addr_set(&addr, htonl(0xff020000), 0, 0, htonl(0x6a)); + ipv6_dev_mc_inc(br->dev, &addr); +} +#else +static inline void br_ip6_multicast_join_snoopers(struct net_bridge *br) +{ +} +#endif + +static void br_multicast_join_snoopers(struct net_bridge *br) +{ + br_ip4_multicast_join_snoopers(br); + br_ip6_multicast_join_snoopers(br); +} + +static void br_ip4_multicast_leave_snoopers(struct net_bridge *br) +{ + struct in_device *in_dev = in_dev_get(br->dev); + + if (WARN_ON(!in_dev)) + return; + + ip_mc_dec_group(in_dev, htonl(INADDR_ALLSNOOPERS_GROUP)); + in_dev_put(in_dev); +} + +#if IS_ENABLED(CONFIG_IPV6) +static void br_ip6_multicast_leave_snoopers(struct net_bridge *br) +{ + struct in6_addr addr; + + ipv6_addr_set(&addr, htonl(0xff020000), 0, 0, htonl(0x6a)); + ipv6_dev_mc_dec(br->dev, &addr); +} +#else +static inline void br_ip6_multicast_leave_snoopers(struct net_bridge *br) +{ +} +#endif + +static void br_multicast_leave_snoopers(struct net_bridge *br) +{ + br_ip4_multicast_leave_snoopers(br); + br_ip6_multicast_leave_snoopers(br); +} + static void __br_multicast_open(struct net_bridge *br, struct bridge_mcast_own_query *query) { @@ -1793,6 +1855,9 @@ static void __br_multicast_open(struct net_bridge *br, void br_multicast_open(struct net_bridge *br) { + if (br_opt_get(br, BROPT_MULTICAST_ENABLED)) + br_multicast_join_snoopers(br); + __br_multicast_open(br, &br->ip4_own_query); #if IS_ENABLED(CONFIG_IPV6) __br_multicast_open(br, &br->ip6_own_query); @@ -1808,6 +1873,9 @@ void br_multicast_stop(struct net_bridge *br) del_timer_sync(&br->ip6_other_query.timer); del_timer_sync(&br->ip6_own_query.timer); #endif + + if (br_opt_get(br, BROPT_MULTICAST_ENABLED)) + br_multicast_leave_snoopers(br); } void br_multicast_dev_del(struct net_bridge *br) @@ -1943,8 +2011,10 @@ int br_multicast_toggle(struct net_bridge *br, unsigned long val) br_mc_disabled_update(br->dev, val); br_opt_toggle(br, BROPT_MULTICAST_ENABLED, !!val); - if (!br_opt_get(br, BROPT_MULTICAST_ENABLED)) + if (!br_opt_get(br, BROPT_MULTICAST_ENABLED)) { + br_multicast_leave_snoopers(br); goto unlock; + } if (!netif_running(br->dev)) goto unlock; -- cgit 1.4.1