bridge: disable snooping if there is no querier
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 <linus.luessing@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 3be89b3..2f7da41 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -267,6 +267,7 @@
unsigned long multicast_query_interval;
unsigned long multicast_query_response_interval;
unsigned long multicast_startup_query_interval;
+ unsigned long multicast_querier_delay_time;
spinlock_t multicast_lock;
struct net_bridge_mdb_htable __rcu *mdb;
@@ -501,6 +502,13 @@
(br->multicast_router == 1 &&
timer_pending(&br->multicast_router_timer));
}
+
+static inline bool br_multicast_querier_exists(struct net_bridge *br)
+{
+ return time_is_before_jiffies(br->multicast_querier_delay_time) &&
+ (br->multicast_querier ||
+ timer_pending(&br->multicast_querier_timer));
+}
#else
static inline int br_multicast_rcv(struct net_bridge *br,
struct net_bridge_port *port,
@@ -557,6 +565,10 @@
{
return 0;
}
+static inline bool br_multicast_querier_exists(struct net_bridge *br)
+{
+ return false;
+}
static inline void br_mdb_init(void)
{
}