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authorLinus Lüssing <linus.luessing@c0d3.blue>2019-01-21 07:26:27 +0100
committerDavid S. Miller <davem@davemloft.net>2019-01-22 17:18:08 -0800
commit4effd28c1245303dce7fd290c501ac2c11052114 (patch)
tree93942c9d3f41fc3e58de6ce99fbc03319ddaa17e /net/bridge
parenta2e2ca3bebe273055a212d754ffe4e0264192d74 (diff)
bridge: join all-snoopers multicast address
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 <linus.luessing@c0d3.blue> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/bridge')
-rw-r--r--net/bridge/br_multicast.c72
1 files changed, 71 insertions, 1 deletions
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;