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, 183 insertions, 75 deletions

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 08e576ada0b..9d1d0e66c35 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -33,7 +33,8 @@
 
 #include "br_private.h"
 
-static void br_multicast_start_querier(struct net_bridge *br);
+static void br_multicast_start_querier(struct net_bridge *br,
+				       struct bridge_mcast_query *query);
 unsigned int br_mdb_rehash_seq;
 
 static inline int br_ip_equal(const struct br_ip *a, const struct br_ip *b)
@@ -755,20 +756,35 @@ static void br_multicast_local_router_expired(unsigned long data)
 {
 }
 
-static void br_multicast_querier_expired(unsigned long data)
+static void br_multicast_querier_expired(struct net_bridge *br,
+					 struct bridge_mcast_query *query)
 {
-	struct net_bridge *br = (void *)data;
-
 	spin_lock(&br->multicast_lock);
 	if (!netif_running(br->dev) || br->multicast_disabled)
 		goto out;
 
-	br_multicast_start_querier(br);
+	br_multicast_start_querier(br, query);
 
 out:
 	spin_unlock(&br->multicast_lock);
 }
 
+static void br_ip4_multicast_querier_expired(unsigned long data)
+{
+	struct net_bridge *br = (void *)data;
+
+	br_multicast_querier_expired(br, &br->ip4_query);
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static void br_ip6_multicast_querier_expired(unsigned long data)
+{
+	struct net_bridge *br = (void *)data;
+
+	br_multicast_querier_expired(br, &br->ip6_query);
+}
+#endif
+
 static void __br_multicast_send_query(struct net_bridge *br,
 				      struct net_bridge_port *port,
 				      struct br_ip *ip)
@@ -789,37 +805,45 @@ static void __br_multicast_send_query(struct net_bridge *br,
 }
 
 static void br_multicast_send_query(struct net_bridge *br,
-				    struct net_bridge_port *port, u32 sent)
+				    struct net_bridge_port *port,
+				    struct bridge_mcast_query *query)
 {
 	unsigned long time;
 	struct br_ip br_group;
+	struct bridge_mcast_querier *querier = NULL;
 
 	if (!netif_running(br->dev) || br->multicast_disabled ||
-	    !br->multicast_querier ||
-	    timer_pending(&br->multicast_querier_timer))
+	    !br->multicast_querier)
 		return;
 
 	memset(&br_group.u, 0, sizeof(br_group.u));
 
-	br_group.proto = htons(ETH_P_IP);
-	__br_multicast_send_query(br, port, &br_group);
-
+	if (port ? (query == &port->ip4_query) :
+		   (query == &br->ip4_query)) {
+		querier = &br->ip4_querier;
+		br_group.proto = htons(ETH_P_IP);
 #if IS_ENABLED(CONFIG_IPV6)
-	br_group.proto = htons(ETH_P_IPV6);
-	__br_multicast_send_query(br, port, &br_group);
+	} else {
+		querier = &br->ip6_querier;
+		br_group.proto = htons(ETH_P_IPV6);
 #endif
+	}
+
+	if (!querier || timer_pending(&querier->timer))
+		return;
+
+	__br_multicast_send_query(br, port, &br_group);
 
 	time = jiffies;
-	time += sent < br->multicast_startup_query_count ?
+	time += query->startup_sent < br->multicast_startup_query_count ?
 		br->multicast_startup_query_interval :
 		br->multicast_query_interval;
-	mod_timer(port ? &port->multicast_query_timer :
-			 &br->multicast_query_timer, time);
+	mod_timer(&query->timer, time);
 }
 
-static void br_multicast_port_query_expired(unsigned long data)
+static void br_multicast_port_query_expired(struct net_bridge_port *port,
+					    struct bridge_mcast_query *query)
 {
-	struct net_bridge_port *port = (void *)data;
 	struct net_bridge *br = port->br;
 
 	spin_lock(&br->multicast_lock);
@@ -827,25 +851,43 @@ static void br_multicast_port_query_expired(unsigned long data)
 	    port->state == BR_STATE_BLOCKING)
 		goto out;
 
-	if (port->multicast_startup_queries_sent <
-	    br->multicast_startup_query_count)
-		port->multicast_startup_queries_sent++;
+	if (query->startup_sent < br->multicast_startup_query_count)
+		query->startup_sent++;
 
-	br_multicast_send_query(port->br, port,
-				port->multicast_startup_queries_sent);
+	br_multicast_send_query(port->br, port, query);
 
 out:
 	spin_unlock(&br->multicast_lock);
 }
 
+static void br_ip4_multicast_port_query_expired(unsigned long data)
+{
+	struct net_bridge_port *port = (void *)data;
+
+	br_multicast_port_query_expired(port, &port->ip4_query);
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static void br_ip6_multicast_port_query_expired(unsigned long data)
+{
+	struct net_bridge_port *port = (void *)data;
+
+	br_multicast_port_query_expired(port, &port->ip6_query);
+}
+#endif
+
 void br_multicast_add_port(struct net_bridge_port *port)
 {
 	port->multicast_router = 1;
 
 	setup_timer(&port->multicast_router_timer, br_multicast_router_expired,
 		    (unsigned long)port);
-	setup_timer(&port->multicast_query_timer,
-		    br_multicast_port_query_expired, (unsigned long)port);
+	setup_timer(&port->ip4_query.timer, br_ip4_multicast_port_query_expired,
+		    (unsigned long)port);
+#if IS_ENABLED(CONFIG_IPV6)
+	setup_timer(&port->ip6_query.timer, br_ip6_multicast_port_query_expired,
+		    (unsigned long)port);
+#endif
 }
 
 void br_multicast_del_port(struct net_bridge_port *port)
@@ -853,13 +895,13 @@ void br_multicast_del_port(struct net_bridge_port *port)
 	del_timer_sync(&port->multicast_router_timer);
 }
 
-static void __br_multicast_enable_port(struct net_bridge_port *port)
+static void br_multicast_enable(struct bridge_mcast_query *query)
 {
-	port->multicast_startup_queries_sent = 0;
+	query->startup_sent = 0;
 
-	if (try_to_del_timer_sync(&port->multicast_query_timer) >= 0 ||
-	    del_timer(&port->multicast_query_timer))
-		mod_timer(&port->multicast_query_timer, jiffies);
+	if (try_to_del_timer_sync(&query->timer) >= 0 ||
+	    del_timer(&query->timer))
+		mod_timer(&query->timer, jiffies);
 }
 
 void br_multicast_enable_port(struct net_bridge_port *port)
@@ -870,7 +912,10 @@ void br_multicast_enable_port(struct net_bridge_port *port)
 	if (br->multicast_disabled || !netif_running(br->dev))
 		goto out;
 
-	__br_multicast_enable_port(port);
+	br_multicast_enable(&port->ip4_query);
+#if IS_ENABLED(CONFIG_IPV6)
+	br_multicast_enable(&port->ip6_query);
+#endif
 
 out:
 	spin_unlock(&br->multicast_lock);
@@ -889,7 +934,10 @@ void br_multicast_disable_port(struct net_bridge_port *port)
 	if (!hlist_unhashed(&port->rlist))
 		hlist_del_init_rcu(&port->rlist);
 	del_timer(&port->multicast_router_timer);
-	del_timer(&port->multicast_query_timer);
+	del_timer(&port->ip4_query.timer);
+#if IS_ENABLED(CONFIG_IPV6)
+	del_timer(&port->ip6_query.timer);
+#endif
 	spin_unlock(&br->multicast_lock);
 }
 
@@ -1014,14 +1062,15 @@ 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)
+static void
+br_multicast_update_querier_timer(struct net_bridge *br,
+				  struct bridge_mcast_querier *querier,
+				  unsigned long max_delay)
 {
-	if (!timer_pending(&br->multicast_querier_timer))
-		br->multicast_querier_delay_time = jiffies + max_delay;
+	if (!timer_pending(&querier->timer))
+		querier->delay_time = jiffies + max_delay;
 
-	mod_timer(&br->multicast_querier_timer,
-		  jiffies + br->multicast_querier_interval);
+	mod_timer(&querier->timer, jiffies + br->multicast_querier_interval);
 }
 
 /*
@@ -1074,12 +1123,13 @@ timer:
 
 static void br_multicast_query_received(struct net_bridge *br,
 					struct net_bridge_port *port,
+					struct bridge_mcast_querier *querier,
 					int saddr,
 					unsigned long max_delay)
 {
 	if (saddr)
-		br_multicast_update_querier_timer(br, max_delay);
-	else if (timer_pending(&br->multicast_querier_timer))
+		br_multicast_update_querier_timer(br, querier, max_delay);
+	else if (timer_pending(&querier->timer))
 		return;
 
 	br_multicast_mark_router(br, port);
@@ -1129,7 +1179,8 @@ 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);
+	br_multicast_query_received(br, port, &br->ip4_querier, !!iph->saddr,
+				    max_delay);
 
 	if (!group)
 		goto out;
@@ -1206,8 +1257,8 @@ 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);
+	br_multicast_query_received(br, port, &br->ip6_querier,
+				    !ipv6_addr_any(&ip6h->saddr), max_delay);
 
 	if (!group)
 		goto out;
@@ -1244,7 +1295,9 @@ out:
 
 static void br_multicast_leave_group(struct net_bridge *br,
 				     struct net_bridge_port *port,
-				     struct br_ip *group)
+				     struct br_ip *group,
+				     struct bridge_mcast_querier *querier,
+				     struct bridge_mcast_query *query)
 {
 	struct net_bridge_mdb_htable *mdb;
 	struct net_bridge_mdb_entry *mp;
@@ -1255,7 +1308,7 @@ static void br_multicast_leave_group(struct net_bridge *br,
 	spin_lock(&br->multicast_lock);
 	if (!netif_running(br->dev) ||
 	    (port && port->state == BR_STATE_DISABLED) ||
-	    timer_pending(&br->multicast_querier_timer))
+	    timer_pending(&querier->timer))
 		goto out;
 
 	mdb = mlock_dereference(br->mdb, br);
@@ -1263,14 +1316,13 @@ static void br_multicast_leave_group(struct net_bridge *br,
 	if (!mp)
 		goto out;
 
-	if (br->multicast_querier &&
-	    !timer_pending(&br->multicast_querier_timer)) {
+	if (br->multicast_querier) {
 		__br_multicast_send_query(br, port, &mp->addr);
 
 		time = jiffies + br->multicast_last_member_count *
 				 br->multicast_last_member_interval;
-		mod_timer(port ? &port->multicast_query_timer :
-				 &br->multicast_query_timer, time);
+
+		mod_timer(&query->timer, time);
 
 		for (p = mlock_dereference(mp->ports, br);
 		     p != NULL;
@@ -1323,7 +1375,6 @@ static void br_multicast_leave_group(struct net_bridge *br,
 			mod_timer(&mp->timer, time);
 		}
 	}
-
 out:
 	spin_unlock(&br->multicast_lock);
 }
@@ -1334,6 +1385,8 @@ static void br_ip4_multicast_leave_group(struct net_bridge *br,
 					 __u16 vid)
 {
 	struct br_ip br_group;
+	struct bridge_mcast_query *query = port ? &port->ip4_query :
+						  &br->ip4_query;
 
 	if (ipv4_is_local_multicast(group))
 		return;
@@ -1342,7 +1395,7 @@ static void br_ip4_multicast_leave_group(struct net_bridge *br,
 	br_group.proto = htons(ETH_P_IP);
 	br_group.vid = vid;
 
-	br_multicast_leave_group(br, port, &br_group);
+	br_multicast_leave_group(br, port, &br_group, &br->ip4_querier, query);
 }
 
 #if IS_ENABLED(CONFIG_IPV6)
@@ -1352,6 +1405,9 @@ static void br_ip6_multicast_leave_group(struct net_bridge *br,
 					 __u16 vid)
 {
 	struct br_ip br_group;
+	struct bridge_mcast_query *query = port ? &port->ip6_query :
+						  &br->ip6_query;
+
 
 	if (!ipv6_is_transient_multicast(group))
 		return;
@@ -1360,7 +1416,7 @@ static void br_ip6_multicast_leave_group(struct net_bridge *br,
 	br_group.proto = htons(ETH_P_IPV6);
 	br_group.vid = vid;
 
-	br_multicast_leave_group(br, port, &br_group);
+	br_multicast_leave_group(br, port, &br_group, &br->ip6_querier, query);
 }
 #endif
 
@@ -1622,19 +1678,32 @@ int br_multicast_rcv(struct net_bridge *br, struct net_bridge_port *port,
 	return 0;
 }
 
-static void br_multicast_query_expired(unsigned long data)
+static void br_multicast_query_expired(struct net_bridge *br,
+				       struct bridge_mcast_query *query)
+{
+	spin_lock(&br->multicast_lock);
+	if (query->startup_sent < br->multicast_startup_query_count)
+		query->startup_sent++;
+
+	br_multicast_send_query(br, NULL, query);
+	spin_unlock(&br->multicast_lock);
+}
+
+static void br_ip4_multicast_query_expired(unsigned long data)
 {
 	struct net_bridge *br = (void *)data;
 
-	spin_lock(&br->multicast_lock);
-	if (br->multicast_startup_queries_sent <
-	    br->multicast_startup_query_count)
-		br->multicast_startup_queries_sent++;
+	br_multicast_query_expired(br, &br->ip4_query);
+}
 
-	br_multicast_send_query(br, NULL, br->multicast_startup_queries_sent);
+#if IS_ENABLED(CONFIG_IPV6)
+static void br_ip6_multicast_query_expired(unsigned long data)
+{
+	struct net_bridge *br = (void *)data;
 
-	spin_unlock(&br->multicast_lock);
+	br_multicast_query_expired(br, &br->ip6_query);
 }
+#endif
 
 void br_multicast_init(struct net_bridge *br)
 {
@@ -1654,25 +1723,43 @@ 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;
+	br->ip4_querier.delay_time = 0;
+#if IS_ENABLED(CONFIG_IPV6)
+	br->ip6_querier.delay_time = 0;
+#endif
 
 	spin_lock_init(&br->multicast_lock);
 	setup_timer(&br->multicast_router_timer,
 		    br_multicast_local_router_expired, 0);
-	setup_timer(&br->multicast_querier_timer,
-		    br_multicast_querier_expired, (unsigned long)br);
-	setup_timer(&br->multicast_query_timer, br_multicast_query_expired,
+	setup_timer(&br->ip4_querier.timer, br_ip4_multicast_querier_expired,
+		    (unsigned long)br);
+	setup_timer(&br->ip4_query.timer, br_ip4_multicast_query_expired,
 		    (unsigned long)br);
+#if IS_ENABLED(CONFIG_IPV6)
+	setup_timer(&br->ip6_querier.timer, br_ip6_multicast_querier_expired,
+		    (unsigned long)br);
+	setup_timer(&br->ip6_query.timer, br_ip6_multicast_query_expired,
+		    (unsigned long)br);
+#endif
 }
 
-void br_multicast_open(struct net_bridge *br)
+static void __br_multicast_open(struct net_bridge *br,
+				struct bridge_mcast_query *query)
 {
-	br->multicast_startup_queries_sent = 0;
+	query->startup_sent = 0;
 
 	if (br->multicast_disabled)
 		return;
 
-	mod_timer(&br->multicast_query_timer, jiffies);
+	mod_timer(&query->timer, jiffies);
+}
+
+void br_multicast_open(struct net_bridge *br)
+{
+	__br_multicast_open(br, &br->ip4_query);
+#if IS_ENABLED(CONFIG_IPV6)
+	__br_multicast_open(br, &br->ip6_query);
+#endif
 }
 
 void br_multicast_stop(struct net_bridge *br)
@@ -1684,8 +1771,12 @@ void br_multicast_stop(struct net_bridge *br)
 	int i;
 
 	del_timer_sync(&br->multicast_router_timer);
-	del_timer_sync(&br->multicast_querier_timer);
-	del_timer_sync(&br->multicast_query_timer);
+	del_timer_sync(&br->ip4_querier.timer);
+	del_timer_sync(&br->ip4_query.timer);
+#if IS_ENABLED(CONFIG_IPV6)
+	del_timer_sync(&br->ip6_querier.timer);
+	del_timer_sync(&br->ip6_query.timer);
+#endif
 
 	spin_lock_bh(&br->multicast_lock);
 	mdb = mlock_dereference(br->mdb, br);
@@ -1788,18 +1879,24 @@ unlock:
 	return err;
 }
 
-static void br_multicast_start_querier(struct net_bridge *br)
+static void br_multicast_start_querier(struct net_bridge *br,
+				       struct bridge_mcast_query *query)
 {
 	struct net_bridge_port *port;
 
-	br_multicast_open(br);
+	__br_multicast_open(br, query);
 
 	list_for_each_entry(port, &br->port_list, list) {
 		if (port->state == BR_STATE_DISABLED ||
 		    port->state == BR_STATE_BLOCKING)
 			continue;
 
-		__br_multicast_enable_port(port);
+		if (query == &br->ip4_query)
+			br_multicast_enable(&port->ip4_query);
+#if IS_ENABLED(CONFIG_IPV6)
+		else
+			br_multicast_enable(&port->ip6_query);
+#endif
 	}
 }
 
@@ -1834,7 +1931,10 @@ rollback:
 			goto rollback;
 	}
 
-	br_multicast_start_querier(br);
+	br_multicast_start_querier(br, &br->ip4_query);
+#if IS_ENABLED(CONFIG_IPV6)
+	br_multicast_start_querier(br, &br->ip6_query);
+#endif
 
 unlock:
 	spin_unlock_bh(&br->multicast_lock);
@@ -1857,10 +1957,18 @@ int br_multicast_set_querier(struct net_bridge *br, unsigned long 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);
+	if (!timer_pending(&br->ip4_querier.timer))
+		br->ip4_querier.delay_time = jiffies + max_delay;
+
+	br_multicast_start_querier(br, &br->ip4_query);
+
+#if IS_ENABLED(CONFIG_IPV6)
+	if (!timer_pending(&br->ip6_querier.timer))
+		br->ip6_querier.delay_time = jiffies + max_delay;
+
+	br_multicast_start_querier(br, &br->ip6_query);
+#endif
 
 unlock:
 	spin_unlock_bh(&br->multicast_lock);