bridge: separate querier and query timer into IGMP/IPv4 and MLD/IPv6 ones

Currently we would still potentially suffer multicast packet loss if there
is just either an IGMP or an MLD querier: For the former case, we would
possibly drop IPv6 multicast packets, for the latter IPv4 ones. This is
because we are currently assuming that if either an IGMP or MLD querier
is present that the other one is present, too.

This patch makes the behaviour and fix added in
"bridge: disable snooping if there is no querier" (b00589af3b04)
to also work if there is either just an IGMP or an MLD querier on the
link: It refines the deactivation of the snooping to be protocol
specific by using separate timers for the snooped IGMP and MLD queries
as well as separate timers for our internal IGMP and MLD queriers.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 46 insertions, 11 deletions

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 2f7da41851bf..263ba9034468 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -66,6 +66,20 @@ struct br_ip
         __u16           vid;
 };
 
+#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
+/* our own querier */
+struct bridge_mcast_query {
+        struct timer_list       timer;
+        u32                     startup_sent;
+};
+
+/* other querier */
+struct bridge_mcast_querier {
+        struct timer_list               timer;
+        unsigned long                   delay_time;
+};
+#endif
+
 struct net_port_vlans {
         u16                             port_idx;
         u16                             pvid;
@@ -162,10 +176,12 @@ struct net_bridge_port
 #define BR_FLOOD                0x00000040
 
 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
-        u32                             multicast_startup_queries_sent;
+        struct bridge_mcast_query       ip4_query;
+#if IS_ENABLED(CONFIG_IPV6)
+        struct bridge_mcast_query       ip6_query;
+#endif /* IS_ENABLED(CONFIG_IPV6) */
         unsigned char                   multicast_router;
         struct timer_list               multicast_router_timer;
-        struct timer_list               multicast_query_timer;
         struct hlist_head               mglist;
         struct hlist_node               rlist;
 #endif
@@ -258,7 +274,6 @@ struct net_bridge
         u32                             hash_max;
 
         u32                             multicast_last_member_count;
-        u32                             multicast_startup_queries_sent;
         u32                             multicast_startup_query_count;
 
         unsigned long                   multicast_last_member_interval;
@@ -267,15 +282,18 @@ struct net_bridge
         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;
         struct hlist_head               router_list;
 
         struct timer_list               multicast_router_timer;
-        struct timer_list               multicast_querier_timer;
-        struct timer_list               multicast_query_timer;
+        struct bridge_mcast_querier     ip4_querier;
+        struct bridge_mcast_query       ip4_query;
+#if IS_ENABLED(CONFIG_IPV6)
+        struct bridge_mcast_querier     ip6_querier;
+        struct bridge_mcast_query       ip6_query;
+#endif /* IS_ENABLED(CONFIG_IPV6) */
 #endif
 
         struct timer_list               hello_timer;
@@ -503,11 +521,27 @@ static inline bool br_multicast_is_router(struct net_bridge *br)
                 timer_pending(&br->multicast_router_timer));
 }
 
-static inline bool br_multicast_querier_exists(struct net_bridge *br)
+static inline bool
+__br_multicast_querier_exists(struct net_bridge *br,
+                              struct bridge_mcast_querier *querier)
+{
+        return time_is_before_jiffies(querier->delay_time) &&
+               (br->multicast_querier || timer_pending(&querier->timer));
+}
+
+static inline bool br_multicast_querier_exists(struct net_bridge *br,
+                                               struct ethhdr *eth)
 {
-        return time_is_before_jiffies(br->multicast_querier_delay_time) &&
-               (br->multicast_querier ||
-                timer_pending(&br->multicast_querier_timer));
+        switch (eth->h_proto) {
+        case (htons(ETH_P_IP)):
+                return __br_multicast_querier_exists(br, &br->ip4_querier);
+#if IS_ENABLED(CONFIG_IPV6)
+        case (htons(ETH_P_IPV6)):
+                return __br_multicast_querier_exists(br, &br->ip6_querier);
+#endif
+        default:
+                return false;
+        }
 }
 #else
 static inline int br_multicast_rcv(struct net_bridge *br,
@@ -565,7 +599,8 @@ static inline bool br_multicast_is_router(struct net_bridge *br)
 {
         return 0;
 }
-static inline bool br_multicast_querier_exists(struct net_bridge *br)
+static inline bool br_multicast_querier_exists(struct net_bridge *br,
+                                               struct ethhdr *eth)
 {
         return false;
 }