[PATCH net-next 0/2] net: bridge: split IPv4/v6 mc router state and export for batman-adv

[PATCH net-next 0/2] net: bridge: split IPv4/v6 mc router state and export for batman-adv

[Linus Lüssing]

Hi,

The following are two patches for the Linux bridge regarding multicast
routers. They are rebased on top of the following fix:
"net: bridge: mcast: fix broken length + header check for MRDv6 Adv." [0]
And should be applied afterwards.

The first one splits the so far combined multicast router state into two
ones, one for IPv4 and one for IPv6, for a more fine-grained detection of
multicast routers. This avoids sending IPv4 multicast packets to an
IPv6-only multicast router and avoids sending IPv6 multicast packets to
an IPv4-only multicast router. This is also in preparation for the
second patch:

The second patch exports this now per protocol family multicast router
state so that batman-adv can then later make full use of the
Multicast Router Discovery (MRD) support in the Linux bridge. The
batman-adv protocol format currently expects separate multicast router
states for IPv4 and IPv6, therefore it depends on the first patch.
batman-adv will then make use of this newly exported functions like
this[1].

Regards, Linus

[0]: https://patchwork.kernel.org/project/netdevbpf/patch/20210425152736.8421-1-linus.luessing@c0d3.blue/
[1]: https://git.open-mesh.org/batman-adv.git/shortlog/refs/heads/linus/multicast-routeable-mrd
     -> https://git.open-mesh.org/batman-adv.git/commit/d4bed3a92427445708baeb1f2d1841c5fb816fd4

[PATCH net-next 1/2] net: bridge: mcast: split multicast router state for IPv4 and IPv6

[Linus Lüssing]

A multicast router for IPv4 does not imply that the same host also is a
multicast router for IPv6 and vice versa.

To reduce multicast traffic when a host is only a multicast router for
one of these two protocol families, keep router state for IPv4 and IPv6
separately. Similar to how querier state is kept separately.

For backwards compatibility for netlink and switchdev notifications
these two will still only notify if a port switched from either no
IPv4/IPv6 multicast router to any IPv4/IPv6 multicast router or the
other way round. However a full netlink MDB router dump will now also
include a multicast router timeout for both IPv4 and IPv6.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
---
 include/uapi/linux/if_bridge.h |   2 +
 net/bridge/br_forward.c        |  22 ++-
 net/bridge/br_input.c          |   2 +-
 net/bridge/br_mdb.c            |  38 +++-
 net/bridge/br_multicast.c      | 341 +++++++++++++++++++++++++--------
 net/bridge/br_private.h        |  48 ++++-
 6 files changed, 352 insertions(+), 101 deletions(-)

diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
index 13d59c51ef5b..6b56a7549531 100644
--- a/include/uapi/linux/if_bridge.h
+++ b/include/uapi/linux/if_bridge.h
@@ -627,6 +627,8 @@ enum {
 	MDBA_ROUTER_PATTR_UNSPEC,
 	MDBA_ROUTER_PATTR_TIMER,
 	MDBA_ROUTER_PATTR_TYPE,
+	MDBA_ROUTER_PATTR_INET_TIMER,
+	MDBA_ROUTER_PATTR_INET6_TIMER,
 	__MDBA_ROUTER_PATTR_MAX
 };
 #define MDBA_ROUTER_PATTR_MAX (__MDBA_ROUTER_PATTR_MAX - 1)
diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index 6e9b049ae521..897fafc83cd0 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -275,8 +275,19 @@ void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
 	struct net_bridge_port_group *p;
 	bool allow_mode_include = true;
 	struct hlist_node *rp;
+#if IS_ENABLED(CONFIG_IPV6)
+	bool is_ipv6 = false;
+
+	if (skb->protocol == htons(ETH_P_IPV6)) {
+		is_ipv6 = true;
+		rp = rcu_dereference(hlist_first_rcu(&br->ip6_mc_router_list));
+	} else {
+#else
+	if (1) {
+#endif
+		rp = rcu_dereference(hlist_first_rcu(&br->ip4_mc_router_list));
+	}
 
-	rp = rcu_dereference(hlist_first_rcu(&br->router_list));
 	if (mdst) {
 		p = rcu_dereference(mdst->ports);
 		if (br_multicast_should_handle_mode(br, mdst->addr.proto) &&
@@ -290,7 +301,14 @@ void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
 		struct net_bridge_port *port, *lport, *rport;
 
 		lport = p ? p->key.port : NULL;
-		rport = hlist_entry_safe(rp, struct net_bridge_port, rlist);
+#if IS_ENABLED(CONFIG_IPV6)
+		if (is_ipv6)
+			rport = hlist_entry_safe(rp, struct net_bridge_port,
+						 ip6_rlist);
+		else
+#endif
+			rport = hlist_entry_safe(rp, struct net_bridge_port,
+						 ip4_rlist);
 
 		if ((unsigned long)lport > (unsigned long)rport) {
 			port = lport;
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 8875e953ac53..1f506309efa8 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -132,7 +132,7 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
 		if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
 		    br_multicast_querier_exists(br, eth_hdr(skb), mdst)) {
 			if ((mdst && mdst->host_joined) ||
-			    br_multicast_is_router(br)) {
+			    br_multicast_is_router(br, skb)) {
 				local_rcv = true;
 				br->dev->stats.multicast++;
 			}
diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c
index 95fa4af0e8dd..2fce1a895a70 100644
--- a/net/bridge/br_mdb.c
+++ b/net/bridge/br_mdb.c
@@ -22,25 +22,53 @@ static int br_rports_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
 	struct net_bridge *br = netdev_priv(dev);
 	struct net_bridge_port *p;
 	struct nlattr *nest, *port_nest;
+	bool have_ip4_mc_rtr, have_ip6_mc_rtr = false;
+	unsigned long ip4_timer, ip6_timer = 0;
 
-	if (!br->multicast_router || hlist_empty(&br->router_list))
+	if (!br->multicast_router)
 		return 0;
 
+#if IS_ENABLED(CONFIG_IPV6)
+	if (hlist_empty(&br->ip4_mc_router_list) &&
+	    hlist_empty(&br->ip6_mc_router_list))
+		return 0;
+#else
+	if (hlist_empty(&br->ip4_mc_router_list))
+		return 0;
+#endif
+
 	nest = nla_nest_start_noflag(skb, MDBA_ROUTER);
 	if (nest == NULL)
 		return -EMSGSIZE;
 
-	hlist_for_each_entry_rcu(p, &br->router_list, rlist) {
-		if (!p)
+	list_for_each_entry_rcu(p, &br->port_list, list) {
+		have_ip4_mc_rtr = !hlist_unhashed(&p->ip4_rlist);
+		ip4_timer = br_timer_value(&p->ip4_mc_router_timer);
+#if IS_ENABLED(CONFIG_IPV6)
+		have_ip6_mc_rtr = !hlist_unhashed(&p->ip6_rlist);
+		ip6_timer = br_timer_value(&p->ip6_mc_router_timer);
+#endif
+
+		if (!have_ip4_mc_rtr && !have_ip6_mc_rtr)
 			continue;
+
 		port_nest = nla_nest_start_noflag(skb, MDBA_ROUTER_PORT);
 		if (!port_nest)
 			goto fail;
+
 		if (nla_put_nohdr(skb, sizeof(u32), &p->dev->ifindex) ||
 		    nla_put_u32(skb, MDBA_ROUTER_PATTR_TIMER,
-				br_timer_value(&p->multicast_router_timer)) ||
+				max(ip4_timer, ip6_timer)) ||
 		    nla_put_u8(skb, MDBA_ROUTER_PATTR_TYPE,
-			       p->multicast_router)) {
+			       p->multicast_router) ||
+		#if IS_ENABLED(CONFIG_IPV6)
+		    (have_ip6_mc_rtr &&
+		     nla_put_u32(skb, MDBA_ROUTER_PATTR_INET6_TIMER,
+				 ip6_timer)) ||
+		#endif
+		    (have_ip4_mc_rtr &&
+		     nla_put_u32(skb, MDBA_ROUTER_PATTR_INET_TIMER,
+				 ip4_timer))) {
 			nla_nest_cancel(skb, port_nest);
 			goto fail;
 		}
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 226bb05c3b42..0ebdbf09f44c 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -51,8 +51,8 @@ static const struct rhashtable_params br_sg_port_rht_params = {
 
 static void br_multicast_start_querier(struct net_bridge *br,
 				       struct bridge_mcast_own_query *query);
-static void br_multicast_add_router(struct net_bridge *br,
-				    struct net_bridge_port *port);
+static void br_ip4_multicast_add_router(struct net_bridge *br,
+					struct net_bridge_port *port);
 static void br_ip4_multicast_leave_group(struct net_bridge *br,
 					 struct net_bridge_port *port,
 					 __be32 group,
@@ -60,8 +60,12 @@ static void br_ip4_multicast_leave_group(struct net_bridge *br,
 					 const unsigned char *src);
 static void br_multicast_port_group_rexmit(struct timer_list *t);
 
-static void __del_port_router(struct net_bridge_port *p);
+static void br_multicast_rport_del(struct net_bridge_port *p,
+				   struct hlist_node *rlist);
+static void br_multicast_rport_del_notify(struct net_bridge_port *p);
 #if IS_ENABLED(CONFIG_IPV6)
+static void br_ip6_multicast_add_router(struct net_bridge *br,
+					struct net_bridge_port *port);
 static void br_ip6_multicast_leave_group(struct net_bridge *br,
 					 struct net_bridge_port *port,
 					 const struct in6_addr *group,
@@ -1354,23 +1358,40 @@ static int br_ip6_multicast_add_group(struct net_bridge *br,
 }
 #endif
 
-static void br_multicast_router_expired(struct timer_list *t)
+static void br_multicast_router_expired(struct net_bridge_port *port,
+					struct timer_list *t,
+					struct hlist_node *rlist)
 {
-	struct net_bridge_port *port =
-			from_timer(port, t, multicast_router_timer);
 	struct net_bridge *br = port->br;
 
 	spin_lock(&br->multicast_lock);
 	if (port->multicast_router == MDB_RTR_TYPE_DISABLED ||
 	    port->multicast_router == MDB_RTR_TYPE_PERM ||
-	    timer_pending(&port->multicast_router_timer))
+	    timer_pending(t))
 		goto out;
 
-	__del_port_router(port);
+	br_multicast_rport_del(port, rlist);
+	br_multicast_rport_del_notify(port);
 out:
 	spin_unlock(&br->multicast_lock);
 }
 
+static void br_ip4_multicast_router_expired(struct timer_list *t)
+{
+	struct net_bridge_port *port = from_timer(port, t, ip4_mc_router_timer);
+
+	br_multicast_router_expired(port, t, &port->ip4_rlist);
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static void br_ip6_multicast_router_expired(struct timer_list *t)
+{
+	struct net_bridge_port *port = from_timer(port, t, ip6_mc_router_timer);
+
+	br_multicast_router_expired(port, t, &port->ip6_rlist);
+}
+#endif
+
 static void br_mc_router_state_change(struct net_bridge *p,
 				      bool is_mc_router)
 {
@@ -1384,14 +1405,14 @@ static void br_mc_router_state_change(struct net_bridge *p,
 	switchdev_port_attr_set(p->dev, &attr, NULL);
 }
 
-static void br_multicast_local_router_expired(struct timer_list *t)
+static void br_multicast_local_router_expired(struct net_bridge *br,
+					      struct timer_list *timer)
 {
-	struct net_bridge *br = from_timer(br, t, multicast_router_timer);
-
 	spin_lock(&br->multicast_lock);
 	if (br->multicast_router == MDB_RTR_TYPE_DISABLED ||
 	    br->multicast_router == MDB_RTR_TYPE_PERM ||
-	    timer_pending(&br->multicast_router_timer))
+	    br_ip4_multicast_is_router(br) ||
+	    br_ip6_multicast_is_router(br))
 		goto out;
 
 	br_mc_router_state_change(br, false);
@@ -1399,6 +1420,22 @@ static void br_multicast_local_router_expired(struct timer_list *t)
 	spin_unlock(&br->multicast_lock);
 }
 
+static inline void br_ip4_multicast_local_router_expired(struct timer_list *t)
+{
+	struct net_bridge *br = from_timer(br, t, ip4_mc_router_timer);
+
+	br_multicast_local_router_expired(br, t);
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static inline void br_ip6_multicast_local_router_expired(struct timer_list *t)
+{
+	struct net_bridge *br = from_timer(br, t, ip6_mc_router_timer);
+
+	br_multicast_local_router_expired(br, t);
+}
+#endif
+
 static void br_multicast_querier_expired(struct net_bridge *br,
 					 struct bridge_mcast_own_query *query)
 {
@@ -1613,11 +1650,13 @@ int br_multicast_add_port(struct net_bridge_port *port)
 	port->multicast_router = MDB_RTR_TYPE_TEMP_QUERY;
 	port->multicast_eht_hosts_limit = BR_MCAST_DEFAULT_EHT_HOSTS_LIMIT;
 
-	timer_setup(&port->multicast_router_timer,
-		    br_multicast_router_expired, 0);
+	timer_setup(&port->ip4_mc_router_timer,
+		    br_ip4_multicast_router_expired, 0);
 	timer_setup(&port->ip4_own_query.timer,
 		    br_ip4_multicast_port_query_expired, 0);
 #if IS_ENABLED(CONFIG_IPV6)
+	timer_setup(&port->ip6_mc_router_timer,
+		    br_ip6_multicast_router_expired, 0);
 	timer_setup(&port->ip6_own_query.timer,
 		    br_ip6_multicast_port_query_expired, 0);
 #endif
@@ -1649,7 +1688,10 @@ void br_multicast_del_port(struct net_bridge_port *port)
 	hlist_move_list(&br->mcast_gc_list, &deleted_head);
 	spin_unlock_bh(&br->multicast_lock);
 	br_multicast_gc(&deleted_head);
-	del_timer_sync(&port->multicast_router_timer);
+	del_timer_sync(&port->ip4_mc_router_timer);
+#if IS_ENABLED(CONFIG_IPV6)
+	del_timer_sync(&port->ip6_mc_router_timer);
+#endif
 	free_percpu(port->mcast_stats);
 }
 
@@ -1673,9 +1715,14 @@ static void __br_multicast_enable_port(struct net_bridge_port *port)
 #if IS_ENABLED(CONFIG_IPV6)
 	br_multicast_enable(&port->ip6_own_query);
 #endif
-	if (port->multicast_router == MDB_RTR_TYPE_PERM &&
-	    hlist_unhashed(&port->rlist))
-		br_multicast_add_router(br, port);
+	if (port->multicast_router == MDB_RTR_TYPE_PERM) {
+		if (hlist_unhashed(&port->ip4_rlist))
+			br_ip4_multicast_add_router(br, port);
+#if IS_ENABLED(CONFIG_IPV6)
+		if (hlist_unhashed(&port->ip6_rlist))
+			br_ip6_multicast_add_router(br, port);
+#endif
+	}
 }
 
 void br_multicast_enable_port(struct net_bridge_port *port)
@@ -1698,13 +1745,15 @@ void br_multicast_disable_port(struct net_bridge_port *port)
 		if (!(pg->flags & MDB_PG_FLAGS_PERMANENT))
 			br_multicast_find_del_pg(br, pg);
 
-	__del_port_router(port);
-
-	del_timer(&port->multicast_router_timer);
+	br_multicast_rport_del(port, &port->ip4_rlist);
+	del_timer(&port->ip4_mc_router_timer);
 	del_timer(&port->ip4_own_query.timer);
 #if IS_ENABLED(CONFIG_IPV6)
+	br_multicast_rport_del(port, &port->ip6_rlist);
+	del_timer(&port->ip6_mc_router_timer);
 	del_timer(&port->ip6_own_query.timer);
 #endif
+	br_multicast_rport_del_notify(port);
 	spin_unlock(&br->multicast_lock);
 }
 
@@ -2615,22 +2664,6 @@ static bool br_ip6_multicast_select_querier(struct net_bridge *br,
 }
 #endif
 
-static bool br_multicast_select_querier(struct net_bridge *br,
-					struct net_bridge_port *port,
-					struct br_ip *saddr)
-{
-	switch (saddr->proto) {
-	case htons(ETH_P_IP):
-		return br_ip4_multicast_select_querier(br, port, saddr->src.ip4);
-#if IS_ENABLED(CONFIG_IPV6)
-	case htons(ETH_P_IPV6):
-		return br_ip6_multicast_select_querier(br, port, &saddr->src.ip6);
-#endif
-	}
-
-	return false;
-}
-
 static void
 br_multicast_update_query_timer(struct net_bridge *br,
 				struct bridge_mcast_other_query *query,
@@ -2655,44 +2688,95 @@ static void br_port_mc_router_state_change(struct net_bridge_port *p,
 	switchdev_port_attr_set(p->dev, &attr, NULL);
 }
 
-/*
- * Add port to router_list
+/* Add port to router_list
  *  list is maintained ordered by pointer value
  *  and locked by br->multicast_lock and RCU
  */
-static void br_multicast_add_router(struct net_bridge *br,
-				    struct net_bridge_port *port)
+static void br_ip4_multicast_add_router(struct net_bridge *br,
+					struct net_bridge_port *port)
 {
 	struct net_bridge_port *p;
 	struct hlist_node *slot = NULL;
 
-	if (!hlist_unhashed(&port->rlist))
+	if (!hlist_unhashed(&port->ip4_rlist))
 		return;
 
-	hlist_for_each_entry(p, &br->router_list, rlist) {
-		if ((unsigned long) port >= (unsigned long) p)
+	hlist_for_each_entry(p, &br->ip4_mc_router_list, ip4_rlist) {
+		if ((unsigned long)port >= (unsigned long)p)
 			break;
-		slot = &p->rlist;
+		slot = &p->ip4_rlist;
 	}
 
 	if (slot)
-		hlist_add_behind_rcu(&port->rlist, slot);
+		hlist_add_behind_rcu(&port->ip4_rlist, slot);
 	else
-		hlist_add_head_rcu(&port->rlist, &br->router_list);
-	br_rtr_notify(br->dev, port, RTM_NEWMDB);
-	br_port_mc_router_state_change(port, true);
+		hlist_add_head_rcu(&port->ip4_rlist, &br->ip4_mc_router_list);
+
+	/* For backwards compatibility for now, only notify if we
+	 * switched from no IPv4/IPv6 multicast router to a new
+	 * IPv4 or IPv6 multicast router.
+	 */
+#if IS_ENABLED(CONFIG_IPV6)
+	if (hlist_unhashed(&port->ip6_rlist)) {
+#else
+	if (1) {
+#endif
+		br_rtr_notify(br->dev, port, RTM_NEWMDB);
+		br_port_mc_router_state_change(port, true);
+	}
 }
 
-static void br_multicast_mark_router(struct net_bridge *br,
-				     struct net_bridge_port *port)
+#if IS_ENABLED(CONFIG_IPV6)
+/* Add port to router_list
+ *  list is maintained ordered by pointer value
+ *  and locked by br->multicast_lock and RCU
+ */
+static void br_ip6_multicast_add_router(struct net_bridge *br,
+					struct net_bridge_port *port)
+{
+	struct net_bridge_port *p;
+	struct hlist_node *slot = NULL;
+
+	if (!hlist_unhashed(&port->ip6_rlist))
+		return;
+
+	hlist_for_each_entry(p, &br->ip6_mc_router_list, ip6_rlist) {
+		if ((unsigned long)port >= (unsigned long)p)
+			break;
+		slot = &p->ip6_rlist;
+	}
+
+	if (slot)
+		hlist_add_behind_rcu(&port->ip6_rlist, slot);
+	else
+		hlist_add_head_rcu(&port->ip6_rlist, &br->ip6_mc_router_list);
+
+	/* For backwards compatibility for now, only notify if we
+	 * switched from no IPv4/IPv6 multicast router to a new
+	 * IPv4 or IPv6 multicast router.
+	 */
+	if (hlist_unhashed(&port->ip4_rlist)) {
+		br_rtr_notify(br->dev, port, RTM_NEWMDB);
+		br_port_mc_router_state_change(port, true);
+	}
+}
+#endif
+
+static void br_ip4_multicast_mark_router(struct net_bridge *br,
+					 struct net_bridge_port *port)
 {
 	unsigned long now = jiffies;
 
 	if (!port) {
 		if (br->multicast_router == MDB_RTR_TYPE_TEMP_QUERY) {
-			if (!timer_pending(&br->multicast_router_timer))
+#if IS_ENABLED(CONFIG_IPV6)
+			if (!timer_pending(&br->ip4_mc_router_timer) &&
+			    !timer_pending(&br->ip6_mc_router_timer))
+#else
+			if (!timer_pending(&br->ip4_mc_router_timer))
+#endif
 				br_mc_router_state_change(br, true);
-			mod_timer(&br->multicast_router_timer,
+			mod_timer(&br->ip4_mc_router_timer,
 				  now + br->multicast_querier_interval);
 		}
 		return;
@@ -2702,24 +2786,69 @@ static void br_multicast_mark_router(struct net_bridge *br,
 	    port->multicast_router == MDB_RTR_TYPE_PERM)
 		return;
 
-	br_multicast_add_router(br, port);
+	br_ip4_multicast_add_router(br, port);
 
-	mod_timer(&port->multicast_router_timer,
+	mod_timer(&port->ip4_mc_router_timer,
 		  now + br->multicast_querier_interval);
 }
 
-static void br_multicast_query_received(struct net_bridge *br,
-					struct net_bridge_port *port,
-					struct bridge_mcast_other_query *query,
-					struct br_ip *saddr,
-					unsigned long max_delay)
+#if IS_ENABLED(CONFIG_IPV6)
+static void br_ip6_multicast_mark_router(struct net_bridge *br,
+					 struct net_bridge_port *port)
+{
+	unsigned long now = jiffies;
+
+	if (!port) {
+		if (br->multicast_router == MDB_RTR_TYPE_TEMP_QUERY) {
+			if (!timer_pending(&br->ip4_mc_router_timer) &&
+			    !timer_pending(&br->ip6_mc_router_timer))
+				br_mc_router_state_change(br, true);
+			mod_timer(&br->ip6_mc_router_timer,
+				  now + br->multicast_querier_interval);
+		}
+		return;
+	}
+
+	if (port->multicast_router == MDB_RTR_TYPE_DISABLED ||
+	    port->multicast_router == MDB_RTR_TYPE_PERM)
+		return;
+
+	br_ip6_multicast_add_router(br, port);
+
+	mod_timer(&port->ip6_mc_router_timer,
+		  now + br->multicast_querier_interval);
+}
+#endif
+
+static void
+br_ip4_multicast_query_received(struct net_bridge *br,
+				struct net_bridge_port *port,
+				struct bridge_mcast_other_query *query,
+				struct br_ip *saddr,
+				unsigned long max_delay)
+{
+	if (!br_ip4_multicast_select_querier(br, port, saddr->src.ip4))
+		return;
+
+	br_multicast_update_query_timer(br, query, max_delay);
+	br_ip4_multicast_mark_router(br, port);
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static void
+br_ip6_multicast_query_received(struct net_bridge *br,
+				struct net_bridge_port *port,
+				struct bridge_mcast_other_query *query,
+				struct br_ip *saddr,
+				unsigned long max_delay)
 {
-	if (!br_multicast_select_querier(br, port, saddr))
+	if (!br_ip6_multicast_select_querier(br, port, &saddr->src.ip6))
 		return;
 
 	br_multicast_update_query_timer(br, query, max_delay);
-	br_multicast_mark_router(br, port);
+	br_ip6_multicast_mark_router(br, port);
 }
+#endif
 
 static void br_ip4_multicast_query(struct net_bridge *br,
 				   struct net_bridge_port *port,
@@ -2768,8 +2897,8 @@ static void br_ip4_multicast_query(struct net_bridge *br,
 		saddr.proto = htons(ETH_P_IP);
 		saddr.src.ip4 = iph->saddr;
 
-		br_multicast_query_received(br, port, &br->ip4_other_query,
-					    &saddr, max_delay);
+		br_ip4_multicast_query_received(br, port, &br->ip4_other_query,
+						&saddr, max_delay);
 		goto out;
 	}
 
@@ -2856,8 +2985,8 @@ static int br_ip6_multicast_query(struct net_bridge *br,
 		saddr.proto = htons(ETH_P_IPV6);
 		saddr.src.ip6 = ipv6_hdr(skb)->saddr;
 
-		br_multicast_query_received(br, port, &br->ip6_other_query,
-					    &saddr, max_delay);
+		br_ip6_multicast_query_received(br, port, &br->ip6_other_query,
+						&saddr, max_delay);
 		goto out;
 	} else if (!group) {
 		goto out;
@@ -3087,7 +3216,7 @@ static void br_multicast_pim(struct net_bridge *br,
 	    pim_hdr_type(pimhdr) != PIM_TYPE_HELLO)
 		return;
 
-	br_multicast_mark_router(br, port);
+	br_ip4_multicast_mark_router(br, port);
 }
 
 static int br_ip4_multicast_mrd_rcv(struct net_bridge *br,
@@ -3098,7 +3227,7 @@ static int br_ip4_multicast_mrd_rcv(struct net_bridge *br,
 	    igmp_hdr(skb)->type != IGMP_MRDISC_ADV)
 		return -ENOMSG;
 
-	br_multicast_mark_router(br, port);
+	br_ip4_multicast_mark_router(br, port);
 
 	return 0;
 }
@@ -3166,7 +3295,7 @@ static void br_ip6_multicast_mrd_rcv(struct net_bridge *br,
 	if (icmp6_hdr(skb)->icmp6_type != ICMPV6_MRDISC_ADV)
 		return;
 
-	br_multicast_mark_router(br, port);
+	br_ip6_multicast_mark_router(br, port);
 }
 
 static int br_multicast_ipv6_rcv(struct net_bridge *br,
@@ -3316,13 +3445,15 @@ void br_multicast_init(struct net_bridge *br)
 	br_opt_toggle(br, BROPT_HAS_IPV6_ADDR, true);
 
 	spin_lock_init(&br->multicast_lock);
-	timer_setup(&br->multicast_router_timer,
-		    br_multicast_local_router_expired, 0);
+	timer_setup(&br->ip4_mc_router_timer,
+		    br_ip4_multicast_local_router_expired, 0);
 	timer_setup(&br->ip4_other_query.timer,
 		    br_ip4_multicast_querier_expired, 0);
 	timer_setup(&br->ip4_own_query.timer,
 		    br_ip4_multicast_query_expired, 0);
 #if IS_ENABLED(CONFIG_IPV6)
+	timer_setup(&br->ip6_mc_router_timer,
+		    br_ip6_multicast_local_router_expired, 0);
 	timer_setup(&br->ip6_other_query.timer,
 		    br_ip6_multicast_querier_expired, 0);
 	timer_setup(&br->ip6_own_query.timer,
@@ -3416,10 +3547,11 @@ void br_multicast_open(struct net_bridge *br)
 
 void br_multicast_stop(struct net_bridge *br)
 {
-	del_timer_sync(&br->multicast_router_timer);
+	del_timer_sync(&br->ip4_mc_router_timer);
 	del_timer_sync(&br->ip4_other_query.timer);
 	del_timer_sync(&br->ip4_own_query.timer);
 #if IS_ENABLED(CONFIG_IPV6)
+	del_timer_sync(&br->ip6_mc_router_timer);
 	del_timer_sync(&br->ip6_other_query.timer);
 	del_timer_sync(&br->ip6_own_query.timer);
 #endif
@@ -3453,7 +3585,10 @@ int br_multicast_set_router(struct net_bridge *br, unsigned long val)
 	case MDB_RTR_TYPE_DISABLED:
 	case MDB_RTR_TYPE_PERM:
 		br_mc_router_state_change(br, val == MDB_RTR_TYPE_PERM);
-		del_timer(&br->multicast_router_timer);
+		del_timer(&br->ip4_mc_router_timer);
+#if IS_ENABLED(CONFIG_IPV6)
+		del_timer(&br->ip6_mc_router_timer);
+#endif
 		br->multicast_router = val;
 		err = 0;
 		break;
@@ -3470,11 +3605,26 @@ int br_multicast_set_router(struct net_bridge *br, unsigned long val)
 	return err;
 }
 
-static void __del_port_router(struct net_bridge_port *p)
+static void br_multicast_rport_del(struct net_bridge_port *p,
+				   struct hlist_node *rlist)
 {
-	if (hlist_unhashed(&p->rlist))
+	if (hlist_unhashed(rlist))
 		return;
-	hlist_del_init_rcu(&p->rlist);
+	hlist_del_init_rcu(rlist);
+}
+
+static void br_multicast_rport_del_notify(struct net_bridge_port *p)
+{
+	/* For backwards compatibility for now, only notify if there is
+	 * no multicast router anymore for both IPv4 and IPv6.
+	 */
+	if (!hlist_unhashed(&p->ip4_rlist))
+		return;
+#if IS_ENABLED(CONFIG_IPV6)
+	if (!hlist_unhashed(&p->ip6_rlist))
+		return;
+#endif
+
 	br_rtr_notify(p->br->dev, p, RTM_DELMDB);
 	br_port_mc_router_state_change(p, false);
 
@@ -3492,30 +3642,51 @@ int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
 	spin_lock(&br->multicast_lock);
 	if (p->multicast_router == val) {
 		/* Refresh the temp router port timer */
-		if (p->multicast_router == MDB_RTR_TYPE_TEMP)
-			mod_timer(&p->multicast_router_timer,
+		if (p->multicast_router == MDB_RTR_TYPE_TEMP) {
+			mod_timer(&p->ip4_mc_router_timer,
 				  now + br->multicast_querier_interval);
+#if IS_ENABLED(CONFIG_IPV6)
+			mod_timer(&p->ip6_mc_router_timer,
+				  now + br->multicast_querier_interval);
+#endif
+		}
 		err = 0;
 		goto unlock;
 	}
 	switch (val) {
 	case MDB_RTR_TYPE_DISABLED:
 		p->multicast_router = MDB_RTR_TYPE_DISABLED;
-		__del_port_router(p);
-		del_timer(&p->multicast_router_timer);
+		br_multicast_rport_del(p, &p->ip4_rlist);
+		del_timer(&p->ip4_mc_router_timer);
+#if IS_ENABLED(CONFIG_IPV6)
+		br_multicast_rport_del(p, &p->ip6_rlist);
+		del_timer(&p->ip6_mc_router_timer);
+#endif
+		br_multicast_rport_del_notify(p);
 		break;
 	case MDB_RTR_TYPE_TEMP_QUERY:
 		p->multicast_router = MDB_RTR_TYPE_TEMP_QUERY;
-		__del_port_router(p);
+		br_multicast_rport_del(p, &p->ip4_rlist);
+#if IS_ENABLED(CONFIG_IPV6)
+		br_multicast_rport_del(p, &p->ip6_rlist);
+#endif
+		br_multicast_rport_del_notify(p);
 		break;
 	case MDB_RTR_TYPE_PERM:
 		p->multicast_router = MDB_RTR_TYPE_PERM;
-		del_timer(&p->multicast_router_timer);
-		br_multicast_add_router(br, p);
+		del_timer(&p->ip4_mc_router_timer);
+		br_ip4_multicast_add_router(br, p);
+#if IS_ENABLED(CONFIG_IPV6)
+		del_timer(&p->ip6_mc_router_timer);
+		br_ip6_multicast_add_router(br, p);
+#endif
 		break;
 	case MDB_RTR_TYPE_TEMP:
 		p->multicast_router = MDB_RTR_TYPE_TEMP;
-		br_multicast_mark_router(br, p);
+		br_ip4_multicast_mark_router(br, p);
+#if IS_ENABLED(CONFIG_IPV6)
+		br_ip6_multicast_mark_router(br, p);
+#endif
 		break;
 	default:
 		goto unlock;
@@ -3621,7 +3792,7 @@ bool br_multicast_router(const struct net_device *dev)
 	bool is_router;
 
 	spin_lock_bh(&br->multicast_lock);
-	is_router = br_multicast_is_router(br);
+	is_router = br_multicast_is_router(br, NULL);
 	spin_unlock_bh(&br->multicast_lock);
 	return is_router;
 }
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 7ce8a77cc6b6..203f64e4d4a2 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -307,16 +307,18 @@ struct net_bridge_port {
 
 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
 	struct bridge_mcast_own_query	ip4_own_query;
+	struct timer_list		ip4_mc_router_timer;
+	struct hlist_node		ip4_rlist;
 #if IS_ENABLED(CONFIG_IPV6)
 	struct bridge_mcast_own_query	ip6_own_query;
+	struct timer_list		ip6_mc_router_timer;
+	struct hlist_node		ip6_rlist;
 #endif /* IS_ENABLED(CONFIG_IPV6) */
 	u32				multicast_eht_hosts_limit;
 	u32				multicast_eht_hosts_cnt;
 	unsigned char			multicast_router;
 	struct bridge_mcast_stats	__percpu *mcast_stats;
-	struct timer_list		multicast_router_timer;
 	struct hlist_head		mglist;
-	struct hlist_node		rlist;
 #endif
 
 #ifdef CONFIG_SYSFS
@@ -449,14 +451,16 @@ struct net_bridge {
 
 	struct hlist_head		mcast_gc_list;
 	struct hlist_head		mdb_list;
-	struct hlist_head		router_list;
 
-	struct timer_list		multicast_router_timer;
+	struct hlist_head		ip4_mc_router_list;
+	struct timer_list		ip4_mc_router_timer;
 	struct bridge_mcast_other_query	ip4_other_query;
 	struct bridge_mcast_own_query	ip4_own_query;
 	struct bridge_mcast_querier	ip4_querier;
 	struct bridge_mcast_stats	__percpu *mcast_stats;
 #if IS_ENABLED(CONFIG_IPV6)
+	struct hlist_head		ip6_mc_router_list;
+	struct timer_list		ip6_mc_router_timer;
 	struct bridge_mcast_other_query	ip6_other_query;
 	struct bridge_mcast_own_query	ip6_own_query;
 	struct bridge_mcast_querier	ip6_querier;
@@ -864,11 +868,39 @@ static inline bool br_group_is_l2(const struct br_ip *group)
 #define mlock_dereference(X, br) \
 	rcu_dereference_protected(X, lockdep_is_held(&br->multicast_lock))
 
-static inline bool br_multicast_is_router(struct net_bridge *br)
+static inline bool br_ip4_multicast_is_router(struct net_bridge *br)
 {
-	return br->multicast_router == 2 ||
-	       (br->multicast_router == 1 &&
-		timer_pending(&br->multicast_router_timer));
+	return timer_pending(&br->ip4_mc_router_timer);
+}
+
+static inline bool br_ip6_multicast_is_router(struct net_bridge *br)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+	return timer_pending(&br->ip6_mc_router_timer);
+#else
+	return false;
+#endif
+}
+
+static inline bool
+br_multicast_is_router(struct net_bridge *br, struct sk_buff *skb)
+{
+	if (br->multicast_router == 2)
+		return true;
+
+	if (br->multicast_router == 1) {
+		if (skb) {
+			if (skb->protocol == htons(ETH_P_IP))
+				return br_ip4_multicast_is_router(br);
+			else if (skb->protocol == htons(ETH_P_IPV6))
+				return br_ip6_multicast_is_router(br);
+		} else {
+			return br_ip4_multicast_is_router(br) ||
+			       br_ip6_multicast_is_router(br);
+		}
+	}
+
+	return false;
 }
 
 static inline bool
-- 
2.31.0

[PATCH net-next 2/2] net: bridge: mcast: export multicast router presence adjacent to a port

[Linus Lüssing]

To properly support routable multicast addresses in batman-adv in a
group-aware way, a batman-adv node needs to know if it serves multicast
routers.

This adds a function to the bridge to export this so that batman-adv
can then make full use of the Multicast Router Discovery capability of
the bridge.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
---
 include/linux/if_bridge.h |  8 ++++++
 net/bridge/br_multicast.c | 58 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h
index 2cc35038a8ca..12e9a32dbca0 100644
--- a/include/linux/if_bridge.h
+++ b/include/linux/if_bridge.h
@@ -67,6 +67,7 @@ int br_multicast_list_adjacent(struct net_device *dev,
 			       struct list_head *br_ip_list);
 bool br_multicast_has_querier_anywhere(struct net_device *dev, int proto);
 bool br_multicast_has_querier_adjacent(struct net_device *dev, int proto);
+bool br_multicast_has_router_adjacent(struct net_device *dev, int proto);
 bool br_multicast_enabled(const struct net_device *dev);
 bool br_multicast_router(const struct net_device *dev);
 int br_mdb_replay(struct net_device *br_dev, struct net_device *dev,
@@ -87,6 +88,13 @@ static inline bool br_multicast_has_querier_adjacent(struct net_device *dev,
 {
 	return false;
 }
+
+static inline bool br_multicast_has_router_adjacent(struct net_device *dev,
+						    int proto)
+{
+	return true;
+}
+
 static inline bool br_multicast_enabled(const struct net_device *dev)
 {
 	return false;
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 0ebdbf09f44c..4afaf011f171 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -4013,6 +4013,64 @@ bool br_multicast_has_querier_adjacent(struct net_device *dev, int proto)
 }
 EXPORT_SYMBOL_GPL(br_multicast_has_querier_adjacent);
 
+/**
+ * br_multicast_has_router_adjacent - Checks for a router behind a bridge port
+ * @dev: The bridge port adjacent to which to check for a multicast router
+ * @proto: The protocol family to check for: IGMP -> ETH_P_IP, MLD -> ETH_P_IPV6
+ *
+ * Checks whether the given interface has a bridge on top and if so returns
+ * true if a multicast router is behind one of the other ports of this
+ * bridge. Otherwise returns false.
+ */
+bool br_multicast_has_router_adjacent(struct net_device *dev, int proto)
+{
+	struct net_bridge_port *port, *p;
+	bool ret = false;
+
+	rcu_read_lock();
+	if (!netif_is_bridge_port(dev))
+		goto unlock;
+
+	port = br_port_get_rcu(dev);
+	if (!port || !port->br)
+		goto unlock;
+
+	switch (proto) {
+	case ETH_P_IP:
+		hlist_for_each_entry_rcu(p, &port->br->ip4_mc_router_list,
+					 ip4_rlist) {
+			if (p == port)
+				continue;
+
+			ret = true;
+			goto unlock;
+		}
+		break;
+#if IS_ENABLED(CONFIG_IPV6)
+	case ETH_P_IPV6:
+		hlist_for_each_entry_rcu(p, &port->br->ip6_mc_router_list,
+					 ip6_rlist) {
+			if (p == port)
+				continue;
+
+			ret = true;
+			goto unlock;
+		}
+		break;
+#endif
+	default:
+		/* when compiled without IPv6 support, be conservative and
+		 * always assume presence of an IPv6 multicast router
+		 */
+		ret = true;
+	}
+
+unlock:
+	rcu_read_unlock();
+	return ret;
+}
+EXPORT_SYMBOL_GPL(br_multicast_has_router_adjacent);
+
 static void br_mcast_stats_add(struct bridge_mcast_stats __percpu *stats,
 			       const struct sk_buff *skb, u8 type, u8 dir)
 {
-- 
2.31.0

Re: [PATCH net-next 1/2] net: bridge: mcast: split multicast router state for IPv4 and IPv6

[Nikolay Aleksandrov]

On 25/04/2021 19:00, Linus Lüssing wrote:
> A multicast router for IPv4 does not imply that the same host also is a
> multicast router for IPv6 and vice versa.
> 
> To reduce multicast traffic when a host is only a multicast router for
> one of these two protocol families, keep router state for IPv4 and IPv6
> separately. Similar to how querier state is kept separately.
> 
> For backwards compatibility for netlink and switchdev notifications
> these two will still only notify if a port switched from either no
> IPv4/IPv6 multicast router to any IPv4/IPv6 multicast router or the
> other way round. However a full netlink MDB router dump will now also
> include a multicast router timeout for both IPv4 and IPv6.
> 
> Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
> ---
>  include/uapi/linux/if_bridge.h |   2 +
>  net/bridge/br_forward.c        |  22 ++-
>  net/bridge/br_input.c          |   2 +-
>  net/bridge/br_mdb.c            |  38 +++-
>  net/bridge/br_multicast.c      | 341 +++++++++++++++++++++++++--------
>  net/bridge/br_private.h        |  48 ++++-
>  6 files changed, 352 insertions(+), 101 deletions(-)
> 

Hi Linus,
A few comments below, in general I like the change.
I'd really like it if this patch could be broken up, up to you I'll review it either way. :)
 
> diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
> index 13d59c51ef5b..6b56a7549531 100644
> --- a/include/uapi/linux/if_bridge.h
> +++ b/include/uapi/linux/if_bridge.h
> @@ -627,6 +627,8 @@ enum {
>  	MDBA_ROUTER_PATTR_UNSPEC,
>  	MDBA_ROUTER_PATTR_TIMER,
>  	MDBA_ROUTER_PATTR_TYPE,
> +	MDBA_ROUTER_PATTR_INET_TIMER,
> +	MDBA_ROUTER_PATTR_INET6_TIMER,
>  	__MDBA_ROUTER_PATTR_MAX
>  };
>  #define MDBA_ROUTER_PATTR_MAX (__MDBA_ROUTER_PATTR_MAX - 1)
> diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
> index 6e9b049ae521..897fafc83cd0 100644
> --- a/net/bridge/br_forward.c
> +++ b/net/bridge/br_forward.c
> @@ -275,8 +275,19 @@ void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
>  	struct net_bridge_port_group *p;
>  	bool allow_mode_include = true;
>  	struct hlist_node *rp;
> +#if IS_ENABLED(CONFIG_IPV6)
> +	bool is_ipv6 = false;
> +
> +	if (skb->protocol == htons(ETH_P_IPV6)) {
> +		is_ipv6 = true;
> +		rp = rcu_dereference(hlist_first_rcu(&br->ip6_mc_router_list));
> +	} else {
> +#else
> +	if (1) {
> +#endif
> +		rp = rcu_dereference(hlist_first_rcu(&br->ip4_mc_router_list));
> +	}
>  
> -	rp = rcu_dereference(hlist_first_rcu(&br->router_list));
>  	if (mdst) {
>  		p = rcu_dereference(mdst->ports);
>  		if (br_multicast_should_handle_mode(br, mdst->addr.proto) &&
> @@ -290,7 +301,14 @@ void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
>  		struct net_bridge_port *port, *lport, *rport;
>  
>  		lport = p ? p->key.port : NULL;
> -		rport = hlist_entry_safe(rp, struct net_bridge_port, rlist);
> +#if IS_ENABLED(CONFIG_IPV6)
> +		if (is_ipv6)
> +			rport = hlist_entry_safe(rp, struct net_bridge_port,
> +						 ip6_rlist);
> +		else
> +#endif
> +			rport = hlist_entry_safe(rp, struct net_bridge_port,
> +						 ip4_rlist);
>  

Please add a pointer to the proper list and retrieve it before this, preferrably also
add a helper to do that.

>  		if ((unsigned long)lport > (unsigned long)rport) {
>  			port = lport;
> diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
> index 8875e953ac53..1f506309efa8 100644
> --- a/net/bridge/br_input.c
> +++ b/net/bridge/br_input.c
> @@ -132,7 +132,7 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
>  		if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
>  		    br_multicast_querier_exists(br, eth_hdr(skb), mdst)) {
>  			if ((mdst && mdst->host_joined) ||
> -			    br_multicast_is_router(br)) {
> +			    br_multicast_is_router(br, skb)) {
>  				local_rcv = true;
>  				br->dev->stats.multicast++;
>  			}
> diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c
> index 95fa4af0e8dd..2fce1a895a70 100644
> --- a/net/bridge/br_mdb.c
> +++ b/net/bridge/br_mdb.c
> @@ -22,25 +22,53 @@ static int br_rports_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
>  	struct net_bridge *br = netdev_priv(dev);
>  	struct net_bridge_port *p;
>  	struct nlattr *nest, *port_nest;
> +	bool have_ip4_mc_rtr, have_ip6_mc_rtr = false;
> +	unsigned long ip4_timer, ip6_timer = 0;
>  

Reverse xmas tree, feel free to fix the current ones as well. :)

> -	if (!br->multicast_router || hlist_empty(&br->router_list))
> +	if (!br->multicast_router)
>  		return 0;
>  
> +#if IS_ENABLED(CONFIG_IPV6)
> +	if (hlist_empty(&br->ip4_mc_router_list) &&
> +	    hlist_empty(&br->ip6_mc_router_list))
> +		return 0;
> +#else
> +	if (hlist_empty(&br->ip4_mc_router_list))
> +		return 0;
> +#endif
> +
>  	nest = nla_nest_start_noflag(skb, MDBA_ROUTER);
>  	if (nest == NULL)
>  		return -EMSGSIZE;
>  
> -	hlist_for_each_entry_rcu(p, &br->router_list, rlist) {
> -		if (!p)
> +	list_for_each_entry_rcu(p, &br->port_list, list) {
> +		have_ip4_mc_rtr = !hlist_unhashed(&p->ip4_rlist);
> +		ip4_timer = br_timer_value(&p->ip4_mc_router_timer);
> +#if IS_ENABLED(CONFIG_IPV6)
> +		have_ip6_mc_rtr = !hlist_unhashed(&p->ip6_rlist);
> +		ip6_timer = br_timer_value(&p->ip6_mc_router_timer);
> +#endif
> +
> +		if (!have_ip4_mc_rtr && !have_ip6_mc_rtr)
>  			continue;
> +
>  		port_nest = nla_nest_start_noflag(skb, MDBA_ROUTER_PORT);
>  		if (!port_nest)
>  			goto fail;
> +
>  		if (nla_put_nohdr(skb, sizeof(u32), &p->dev->ifindex) ||
>  		    nla_put_u32(skb, MDBA_ROUTER_PATTR_TIMER,
> -				br_timer_value(&p->multicast_router_timer)) ||
> +				max(ip4_timer, ip6_timer)) ||
>  		    nla_put_u8(skb, MDBA_ROUTER_PATTR_TYPE,
> -			       p->multicast_router)) {
> +			       p->multicast_router) ||
> +		#if IS_ENABLED(CONFIG_IPV6)
> +		    (have_ip6_mc_rtr &&
> +		     nla_put_u32(skb, MDBA_ROUTER_PATTR_INET6_TIMER,
> +				 ip6_timer)) ||
> +		#endif
> +		    (have_ip4_mc_rtr &&
> +		     nla_put_u32(skb, MDBA_ROUTER_PATTR_INET_TIMER,
> +				 ip4_timer))) {
>  			nla_nest_cancel(skb, port_nest);
>  			goto fail;
>  		}
> diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
> index 226bb05c3b42..0ebdbf09f44c 100644
> --- a/net/bridge/br_multicast.c
> +++ b/net/bridge/br_multicast.c
> @@ -51,8 +51,8 @@ static const struct rhashtable_params br_sg_port_rht_params = {
>  
>  static void br_multicast_start_querier(struct net_bridge *br,
>  				       struct bridge_mcast_own_query *query);
> -static void br_multicast_add_router(struct net_bridge *br,
> -				    struct net_bridge_port *port);
> +static void br_ip4_multicast_add_router(struct net_bridge *br,
> +					struct net_bridge_port *port);
>  static void br_ip4_multicast_leave_group(struct net_bridge *br,
>  					 struct net_bridge_port *port,
>  					 __be32 group,
> @@ -60,8 +60,12 @@ static void br_ip4_multicast_leave_group(struct net_bridge *br,
>  					 const unsigned char *src);
>  static void br_multicast_port_group_rexmit(struct timer_list *t);
>  
> -static void __del_port_router(struct net_bridge_port *p);
> +static void br_multicast_rport_del(struct net_bridge_port *p,
> +				   struct hlist_node *rlist);
> +static void br_multicast_rport_del_notify(struct net_bridge_port *p);
>  #if IS_ENABLED(CONFIG_IPV6)
> +static void br_ip6_multicast_add_router(struct net_bridge *br,
> +					struct net_bridge_port *port);
>  static void br_ip6_multicast_leave_group(struct net_bridge *br,
>  					 struct net_bridge_port *port,
>  					 const struct in6_addr *group,
> @@ -1354,23 +1358,40 @@ static int br_ip6_multicast_add_group(struct net_bridge *br,
>  }
>  #endif
>  
> -static void br_multicast_router_expired(struct timer_list *t)
> +static void br_multicast_router_expired(struct net_bridge_port *port,
> +					struct timer_list *t,
> +					struct hlist_node *rlist)
>  {
> -	struct net_bridge_port *port =
> -			from_timer(port, t, multicast_router_timer);
>  	struct net_bridge *br = port->br;
>  
>  	spin_lock(&br->multicast_lock);
>  	if (port->multicast_router == MDB_RTR_TYPE_DISABLED ||
>  	    port->multicast_router == MDB_RTR_TYPE_PERM ||
> -	    timer_pending(&port->multicast_router_timer))
> +	    timer_pending(t))
>  		goto out;
>  
> -	__del_port_router(port);
> +	br_multicast_rport_del(port, rlist);
> +	br_multicast_rport_del_notify(port);
>  out:
>  	spin_unlock(&br->multicast_lock);
>  }
>  
> +static void br_ip4_multicast_router_expired(struct timer_list *t)
> +{
> +	struct net_bridge_port *port = from_timer(port, t, ip4_mc_router_timer);
> +
> +	br_multicast_router_expired(port, t, &port->ip4_rlist);
> +}
> +
> +#if IS_ENABLED(CONFIG_IPV6)
> +static void br_ip6_multicast_router_expired(struct timer_list *t)
> +{
> +	struct net_bridge_port *port = from_timer(port, t, ip6_mc_router_timer);
> +
> +	br_multicast_router_expired(port, t, &port->ip6_rlist);
> +}
> +#endif
> +
>  static void br_mc_router_state_change(struct net_bridge *p,
>  				      bool is_mc_router)
>  {
> @@ -1384,14 +1405,14 @@ static void br_mc_router_state_change(struct net_bridge *p,
>  	switchdev_port_attr_set(p->dev, &attr, NULL);
>  }
>  
> -static void br_multicast_local_router_expired(struct timer_list *t)
> +static void br_multicast_local_router_expired(struct net_bridge *br,
> +					      struct timer_list *timer)
>  {
> -	struct net_bridge *br = from_timer(br, t, multicast_router_timer);
> -
>  	spin_lock(&br->multicast_lock);
>  	if (br->multicast_router == MDB_RTR_TYPE_DISABLED ||
>  	    br->multicast_router == MDB_RTR_TYPE_PERM ||
> -	    timer_pending(&br->multicast_router_timer))
> +	    br_ip4_multicast_is_router(br) ||
> +	    br_ip6_multicast_is_router(br))
>  		goto out;
>  
>  	br_mc_router_state_change(br, false);
> @@ -1399,6 +1420,22 @@ static void br_multicast_local_router_expired(struct timer_list *t)
>  	spin_unlock(&br->multicast_lock);
>  }
>  
> +static inline void br_ip4_multicast_local_router_expired(struct timer_list *t)
> +{
> +	struct net_bridge *br = from_timer(br, t, ip4_mc_router_timer);
> +
> +	br_multicast_local_router_expired(br, t);
> +}
> +
> +#if IS_ENABLED(CONFIG_IPV6)
> +static inline void br_ip6_multicast_local_router_expired(struct timer_list *t)
> +{
> +	struct net_bridge *br = from_timer(br, t, ip6_mc_router_timer);
> +
> +	br_multicast_local_router_expired(br, t);
> +}
> +#endif
> +
>  static void br_multicast_querier_expired(struct net_bridge *br,
>  					 struct bridge_mcast_own_query *query)
>  {
> @@ -1613,11 +1650,13 @@ int br_multicast_add_port(struct net_bridge_port *port)
>  	port->multicast_router = MDB_RTR_TYPE_TEMP_QUERY;
>  	port->multicast_eht_hosts_limit = BR_MCAST_DEFAULT_EHT_HOSTS_LIMIT;
>  
> -	timer_setup(&port->multicast_router_timer,
> -		    br_multicast_router_expired, 0);
> +	timer_setup(&port->ip4_mc_router_timer,
> +		    br_ip4_multicast_router_expired, 0);
>  	timer_setup(&port->ip4_own_query.timer,
>  		    br_ip4_multicast_port_query_expired, 0);
>  #if IS_ENABLED(CONFIG_IPV6)
> +	timer_setup(&port->ip6_mc_router_timer,
> +		    br_ip6_multicast_router_expired, 0);
>  	timer_setup(&port->ip6_own_query.timer,
>  		    br_ip6_multicast_port_query_expired, 0);
>  #endif
> @@ -1649,7 +1688,10 @@ void br_multicast_del_port(struct net_bridge_port *port)
>  	hlist_move_list(&br->mcast_gc_list, &deleted_head);
>  	spin_unlock_bh(&br->multicast_lock);
>  	br_multicast_gc(&deleted_head);
> -	del_timer_sync(&port->multicast_router_timer);
> +	del_timer_sync(&port->ip4_mc_router_timer);
> +#if IS_ENABLED(CONFIG_IPV6)
> +	del_timer_sync(&port->ip6_mc_router_timer);
> +#endif
>  	free_percpu(port->mcast_stats);
>  }
>  
> @@ -1673,9 +1715,14 @@ static void __br_multicast_enable_port(struct net_bridge_port *port)
>  #if IS_ENABLED(CONFIG_IPV6)
>  	br_multicast_enable(&port->ip6_own_query);
>  #endif
> -	if (port->multicast_router == MDB_RTR_TYPE_PERM &&
> -	    hlist_unhashed(&port->rlist))
> -		br_multicast_add_router(br, port);
> +	if (port->multicast_router == MDB_RTR_TYPE_PERM) {
> +		if (hlist_unhashed(&port->ip4_rlist))
> +			br_ip4_multicast_add_router(br, port);
> +#if IS_ENABLED(CONFIG_IPV6)
> +		if (hlist_unhashed(&port->ip6_rlist))
> +			br_ip6_multicast_add_router(br, port);
> +#endif
> +	}
>  }
>  
>  void br_multicast_enable_port(struct net_bridge_port *port)
> @@ -1698,13 +1745,15 @@ void br_multicast_disable_port(struct net_bridge_port *port)
>  		if (!(pg->flags & MDB_PG_FLAGS_PERMANENT))
>  			br_multicast_find_del_pg(br, pg);
>  
> -	__del_port_router(port);
> -
> -	del_timer(&port->multicast_router_timer);
> +	br_multicast_rport_del(port, &port->ip4_rlist);
> +	del_timer(&port->ip4_mc_router_timer);
>  	del_timer(&port->ip4_own_query.timer);
>  #if IS_ENABLED(CONFIG_IPV6)
> +	br_multicast_rport_del(port, &port->ip6_rlist);
> +	del_timer(&port->ip6_mc_router_timer);
>  	del_timer(&port->ip6_own_query.timer);
>  #endif
> +	br_multicast_rport_del_notify(port);
>  	spin_unlock(&br->multicast_lock);
>  }
>  
> @@ -2615,22 +2664,6 @@ static bool br_ip6_multicast_select_querier(struct net_bridge *br,
>  }
>  #endif
>  
> -static bool br_multicast_select_querier(struct net_bridge *br,
> -					struct net_bridge_port *port,
> -					struct br_ip *saddr)
> -{
> -	switch (saddr->proto) {
> -	case htons(ETH_P_IP):
> -		return br_ip4_multicast_select_querier(br, port, saddr->src.ip4);
> -#if IS_ENABLED(CONFIG_IPV6)
> -	case htons(ETH_P_IPV6):
> -		return br_ip6_multicast_select_querier(br, port, &saddr->src.ip6);
> -#endif
> -	}
> -
> -	return false;
> -}
> -
>  static void
>  br_multicast_update_query_timer(struct net_bridge *br,
>  				struct bridge_mcast_other_query *query,
> @@ -2655,44 +2688,95 @@ static void br_port_mc_router_state_change(struct net_bridge_port *p,
>  	switchdev_port_attr_set(p->dev, &attr, NULL);
>  }
>  
> -/*
> - * Add port to router_list
> +/* Add port to router_list
>   *  list is maintained ordered by pointer value
>   *  and locked by br->multicast_lock and RCU
>   */
> -static void br_multicast_add_router(struct net_bridge *br,
> -				    struct net_bridge_port *port)
> +static void br_ip4_multicast_add_router(struct net_bridge *br,
> +					struct net_bridge_port *port)
>  {
>  	struct net_bridge_port *p;
>  	struct hlist_node *slot = NULL;
>  
> -	if (!hlist_unhashed(&port->rlist))
> +	if (!hlist_unhashed(&port->ip4_rlist))
>  		return;
>  
> -	hlist_for_each_entry(p, &br->router_list, rlist) {
> -		if ((unsigned long) port >= (unsigned long) p)
> +	hlist_for_each_entry(p, &br->ip4_mc_router_list, ip4_rlist) {
> +		if ((unsigned long)port >= (unsigned long)p)
>  			break;
> -		slot = &p->rlist;
> +		slot = &p->ip4_rlist;
>  	}
>  
>  	if (slot)
> -		hlist_add_behind_rcu(&port->rlist, slot);
> +		hlist_add_behind_rcu(&port->ip4_rlist, slot);
>  	else
> -		hlist_add_head_rcu(&port->rlist, &br->router_list);
> -	br_rtr_notify(br->dev, port, RTM_NEWMDB);
> -	br_port_mc_router_state_change(port, true);
> +		hlist_add_head_rcu(&port->ip4_rlist, &br->ip4_mc_router_list);
> +
> +	/* For backwards compatibility for now, only notify if we
> +	 * switched from no IPv4/IPv6 multicast router to a new
> +	 * IPv4 or IPv6 multicast router.
> +	 */
> +#if IS_ENABLED(CONFIG_IPV6)
> +	if (hlist_unhashed(&port->ip6_rlist)) {
> +#else
> +	if (1) {
> +#endif
> +		br_rtr_notify(br->dev, port, RTM_NEWMDB);
> +		br_port_mc_router_state_change(port, true);
> +	}
>  }
>  
> -static void br_multicast_mark_router(struct net_bridge *br,
> -				     struct net_bridge_port *port)
> +#if IS_ENABLED(CONFIG_IPV6)
> +/* Add port to router_list
> + *  list is maintained ordered by pointer value
> + *  and locked by br->multicast_lock and RCU
> + */
> +static void br_ip6_multicast_add_router(struct net_bridge *br,
> +					struct net_bridge_port *port)
> +{
> +	struct net_bridge_port *p;
> +	struct hlist_node *slot = NULL;
> +

Reverse xmas tree order.

> +	if (!hlist_unhashed(&port->ip6_rlist))
> +		return;
> +
> +	hlist_for_each_entry(p, &br->ip6_mc_router_list, ip6_rlist) {
> +		if ((unsigned long)port >= (unsigned long)p)
> +			break;
> +		slot = &p->ip6_rlist;
> +	}
> +
> +	if (slot)
> +		hlist_add_behind_rcu(&port->ip6_rlist, slot);
> +	else
> +		hlist_add_head_rcu(&port->ip6_rlist, &br->ip6_mc_router_list);
> +
> +	/* For backwards compatibility for now, only notify if we
> +	 * switched from no IPv4/IPv6 multicast router to a new
> +	 * IPv4 or IPv6 multicast router.
> +	 */
> +	if (hlist_unhashed(&port->ip4_rlist)) {
> +		br_rtr_notify(br->dev, port, RTM_NEWMDB);
> +		br_port_mc_router_state_change(port, true);
> +	}
> +}
> +#endif

The add router functions are almost identical, perhaps they can share the common code.

> +
> +static void br_ip4_multicast_mark_router(struct net_bridge *br,
> +					 struct net_bridge_port *port)
>  {
>  	unsigned long now = jiffies;
>  
>  	if (!port) {
>  		if (br->multicast_router == MDB_RTR_TYPE_TEMP_QUERY) {
> -			if (!timer_pending(&br->multicast_router_timer))
> +#if IS_ENABLED(CONFIG_IPV6)
> +			if (!timer_pending(&br->ip4_mc_router_timer) &&
> +			    !timer_pending(&br->ip6_mc_router_timer))
> +#else
> +			if (!timer_pending(&br->ip4_mc_router_timer))
> +#endif
>  				br_mc_router_state_change(br, true);
> -			mod_timer(&br->multicast_router_timer,
> +			mod_timer(&br->ip4_mc_router_timer,
>  				  now + br->multicast_querier_interval);
>  		}
>  		return;
> @@ -2702,24 +2786,69 @@ static void br_multicast_mark_router(struct net_bridge *br,
>  	    port->multicast_router == MDB_RTR_TYPE_PERM)
>  		return;
>  
> -	br_multicast_add_router(br, port);
> +	br_ip4_multicast_add_router(br, port);
>  
> -	mod_timer(&port->multicast_router_timer,
> +	mod_timer(&port->ip4_mc_router_timer,
>  		  now + br->multicast_querier_interval);
>  }
>  
> -static void br_multicast_query_received(struct net_bridge *br,
> -					struct net_bridge_port *port,
> -					struct bridge_mcast_other_query *query,
> -					struct br_ip *saddr,
> -					unsigned long max_delay)
> +#if IS_ENABLED(CONFIG_IPV6)
> +static void br_ip6_multicast_mark_router(struct net_bridge *br,
> +					 struct net_bridge_port *port)
> +{
> +	unsigned long now = jiffies;
> +
> +	if (!port) {
> +		if (br->multicast_router == MDB_RTR_TYPE_TEMP_QUERY) {
> +			if (!timer_pending(&br->ip4_mc_router_timer) &&
> +			    !timer_pending(&br->ip6_mc_router_timer))
> +				br_mc_router_state_change(br, true);
> +			mod_timer(&br->ip6_mc_router_timer,
> +				  now + br->multicast_querier_interval);
> +		}
> +		return;
> +	}
> +
> +	if (port->multicast_router == MDB_RTR_TYPE_DISABLED ||
> +	    port->multicast_router == MDB_RTR_TYPE_PERM)
> +		return;
> +
> +	br_ip6_multicast_add_router(br, port);
> +
> +	mod_timer(&port->ip6_mc_router_timer,
> +		  now + br->multicast_querier_interval);
> +}
> +#endif
> +
> +static void
> +br_ip4_multicast_query_received(struct net_bridge *br,
> +				struct net_bridge_port *port,
> +				struct bridge_mcast_other_query *query,
> +				struct br_ip *saddr,
> +				unsigned long max_delay)
> +{
> +	if (!br_ip4_multicast_select_querier(br, port, saddr->src.ip4))
> +		return;
> +
> +	br_multicast_update_query_timer(br, query, max_delay);
> +	br_ip4_multicast_mark_router(br, port);
> +}
> +
> +#if IS_ENABLED(CONFIG_IPV6)
> +static void
> +br_ip6_multicast_query_received(struct net_bridge *br,
> +				struct net_bridge_port *port,
> +				struct bridge_mcast_other_query *query,
> +				struct br_ip *saddr,
> +				unsigned long max_delay)
>  {
> -	if (!br_multicast_select_querier(br, port, saddr))
> +	if (!br_ip6_multicast_select_querier(br, port, &saddr->src.ip6))
>  		return;
>  
>  	br_multicast_update_query_timer(br, query, max_delay);
> -	br_multicast_mark_router(br, port);
> +	br_ip6_multicast_mark_router(br, port);
>  }
> +#endif
>  
>  static void br_ip4_multicast_query(struct net_bridge *br,
>  				   struct net_bridge_port *port,
> @@ -2768,8 +2897,8 @@ static void br_ip4_multicast_query(struct net_bridge *br,
>  		saddr.proto = htons(ETH_P_IP);
>  		saddr.src.ip4 = iph->saddr;
>  
> -		br_multicast_query_received(br, port, &br->ip4_other_query,
> -					    &saddr, max_delay);
> +		br_ip4_multicast_query_received(br, port, &br->ip4_other_query,
> +						&saddr, max_delay);
>  		goto out;
>  	}
>  
> @@ -2856,8 +2985,8 @@ static int br_ip6_multicast_query(struct net_bridge *br,
>  		saddr.proto = htons(ETH_P_IPV6);
>  		saddr.src.ip6 = ipv6_hdr(skb)->saddr;
>  
> -		br_multicast_query_received(br, port, &br->ip6_other_query,
> -					    &saddr, max_delay);
> +		br_ip6_multicast_query_received(br, port, &br->ip6_other_query,
> +						&saddr, max_delay);
>  		goto out;
>  	} else if (!group) {
>  		goto out;
> @@ -3087,7 +3216,7 @@ static void br_multicast_pim(struct net_bridge *br,
>  	    pim_hdr_type(pimhdr) != PIM_TYPE_HELLO)
>  		return;
>  
> -	br_multicast_mark_router(br, port);
> +	br_ip4_multicast_mark_router(br, port);
>  }
>  
>  static int br_ip4_multicast_mrd_rcv(struct net_bridge *br,
> @@ -3098,7 +3227,7 @@ static int br_ip4_multicast_mrd_rcv(struct net_bridge *br,
>  	    igmp_hdr(skb)->type != IGMP_MRDISC_ADV)
>  		return -ENOMSG;
>  
> -	br_multicast_mark_router(br, port);
> +	br_ip4_multicast_mark_router(br, port);
>  
>  	return 0;
>  }
> @@ -3166,7 +3295,7 @@ static void br_ip6_multicast_mrd_rcv(struct net_bridge *br,
>  	if (icmp6_hdr(skb)->icmp6_type != ICMPV6_MRDISC_ADV)
>  		return;
>  
> -	br_multicast_mark_router(br, port);
> +	br_ip6_multicast_mark_router(br, port);
>  }
>  
>  static int br_multicast_ipv6_rcv(struct net_bridge *br,
> @@ -3316,13 +3445,15 @@ void br_multicast_init(struct net_bridge *br)
>  	br_opt_toggle(br, BROPT_HAS_IPV6_ADDR, true);
>  
>  	spin_lock_init(&br->multicast_lock);
> -	timer_setup(&br->multicast_router_timer,
> -		    br_multicast_local_router_expired, 0);
> +	timer_setup(&br->ip4_mc_router_timer,
> +		    br_ip4_multicast_local_router_expired, 0);
>  	timer_setup(&br->ip4_other_query.timer,
>  		    br_ip4_multicast_querier_expired, 0);
>  	timer_setup(&br->ip4_own_query.timer,
>  		    br_ip4_multicast_query_expired, 0);
>  #if IS_ENABLED(CONFIG_IPV6)
> +	timer_setup(&br->ip6_mc_router_timer,
> +		    br_ip6_multicast_local_router_expired, 0);
>  	timer_setup(&br->ip6_other_query.timer,
>  		    br_ip6_multicast_querier_expired, 0);
>  	timer_setup(&br->ip6_own_query.timer,
> @@ -3416,10 +3547,11 @@ void br_multicast_open(struct net_bridge *br)
>  
>  void br_multicast_stop(struct net_bridge *br)
>  {
> -	del_timer_sync(&br->multicast_router_timer);
> +	del_timer_sync(&br->ip4_mc_router_timer);
>  	del_timer_sync(&br->ip4_other_query.timer);
>  	del_timer_sync(&br->ip4_own_query.timer);
>  #if IS_ENABLED(CONFIG_IPV6)
> +	del_timer_sync(&br->ip6_mc_router_timer);
>  	del_timer_sync(&br->ip6_other_query.timer);
>  	del_timer_sync(&br->ip6_own_query.timer);
>  #endif
> @@ -3453,7 +3585,10 @@ int br_multicast_set_router(struct net_bridge *br, unsigned long val)
>  	case MDB_RTR_TYPE_DISABLED:
>  	case MDB_RTR_TYPE_PERM:
>  		br_mc_router_state_change(br, val == MDB_RTR_TYPE_PERM);
> -		del_timer(&br->multicast_router_timer);
> +		del_timer(&br->ip4_mc_router_timer);
> +#if IS_ENABLED(CONFIG_IPV6)
> +		del_timer(&br->ip6_mc_router_timer);
> +#endif
>  		br->multicast_router = val;
>  		err = 0;
>  		break;
> @@ -3470,11 +3605,26 @@ int br_multicast_set_router(struct net_bridge *br, unsigned long val)
>  	return err;
>  }
>  
> -static void __del_port_router(struct net_bridge_port *p)
> +static void br_multicast_rport_del(struct net_bridge_port *p,
> +				   struct hlist_node *rlist)
>  {
> -	if (hlist_unhashed(&p->rlist))
> +	if (hlist_unhashed(rlist))
>  		return;
> -	hlist_del_init_rcu(&p->rlist);
> +	hlist_del_init_rcu(rlist);
> +}
> +
> +static void br_multicast_rport_del_notify(struct net_bridge_port *p)
> +{
> +	/* For backwards compatibility for now, only notify if there is
> +	 * no multicast router anymore for both IPv4 and IPv6.
> +	 */
> +	if (!hlist_unhashed(&p->ip4_rlist))
> +		return;
> +#if IS_ENABLED(CONFIG_IPV6)
> +	if (!hlist_unhashed(&p->ip6_rlist))
> +		return;
> +#endif
> +
>  	br_rtr_notify(p->br->dev, p, RTM_DELMDB);
>  	br_port_mc_router_state_change(p, false);
>  
> @@ -3492,30 +3642,51 @@ int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
>  	spin_lock(&br->multicast_lock);
>  	if (p->multicast_router == val) {
>  		/* Refresh the temp router port timer */
> -		if (p->multicast_router == MDB_RTR_TYPE_TEMP)
> -			mod_timer(&p->multicast_router_timer,
> +		if (p->multicast_router == MDB_RTR_TYPE_TEMP) {
> +			mod_timer(&p->ip4_mc_router_timer,
>  				  now + br->multicast_querier_interval);
> +#if IS_ENABLED(CONFIG_IPV6)
> +			mod_timer(&p->ip6_mc_router_timer,
> +				  now + br->multicast_querier_interval);
> +#endif
> +		}
>  		err = 0;
>  		goto unlock;
>  	}
>  	switch (val) {
>  	case MDB_RTR_TYPE_DISABLED:
>  		p->multicast_router = MDB_RTR_TYPE_DISABLED;
> -		__del_port_router(p);
> -		del_timer(&p->multicast_router_timer);
> +		br_multicast_rport_del(p, &p->ip4_rlist);
> +		del_timer(&p->ip4_mc_router_timer);
> +#if IS_ENABLED(CONFIG_IPV6)
> +		br_multicast_rport_del(p, &p->ip6_rlist);
> +		del_timer(&p->ip6_mc_router_timer);
> +#endif
> +		br_multicast_rport_del_notify(p);
>  		break;
>  	case MDB_RTR_TYPE_TEMP_QUERY:
>  		p->multicast_router = MDB_RTR_TYPE_TEMP_QUERY;
> -		__del_port_router(p);
> +		br_multicast_rport_del(p, &p->ip4_rlist);
> +#if IS_ENABLED(CONFIG_IPV6)
> +		br_multicast_rport_del(p, &p->ip6_rlist);
> +#endif
> +		br_multicast_rport_del_notify(p);
>  		break;
>  	case MDB_RTR_TYPE_PERM:
>  		p->multicast_router = MDB_RTR_TYPE_PERM;
> -		del_timer(&p->multicast_router_timer);
> -		br_multicast_add_router(br, p);
> +		del_timer(&p->ip4_mc_router_timer);
> +		br_ip4_multicast_add_router(br, p);
> +#if IS_ENABLED(CONFIG_IPV6)
> +		del_timer(&p->ip6_mc_router_timer);
> +		br_ip6_multicast_add_router(br, p);
> +#endif
>  		break;
>  	case MDB_RTR_TYPE_TEMP:
>  		p->multicast_router = MDB_RTR_TYPE_TEMP;
> -		br_multicast_mark_router(br, p);
> +		br_ip4_multicast_mark_router(br, p);
> +#if IS_ENABLED(CONFIG_IPV6)
> +		br_ip6_multicast_mark_router(br, p);
> +#endif
>  		break;
>  	default:
>  		goto unlock;
> @@ -3621,7 +3792,7 @@ bool br_multicast_router(const struct net_device *dev)
>  	bool is_router;
>  
>  	spin_lock_bh(&br->multicast_lock);
> -	is_router = br_multicast_is_router(br);
> +	is_router = br_multicast_is_router(br, NULL);
>  	spin_unlock_bh(&br->multicast_lock);
>  	return is_router;
>  }
> diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
> index 7ce8a77cc6b6..203f64e4d4a2 100644
> --- a/net/bridge/br_private.h
> +++ b/net/bridge/br_private.h
> @@ -307,16 +307,18 @@ struct net_bridge_port {
>  
>  #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
>  	struct bridge_mcast_own_query	ip4_own_query;
> +	struct timer_list		ip4_mc_router_timer;
> +	struct hlist_node		ip4_rlist;
>  #if IS_ENABLED(CONFIG_IPV6)
>  	struct bridge_mcast_own_query	ip6_own_query;
> +	struct timer_list		ip6_mc_router_timer;
> +	struct hlist_node		ip6_rlist;
>  #endif /* IS_ENABLED(CONFIG_IPV6) */
>  	u32				multicast_eht_hosts_limit;
>  	u32				multicast_eht_hosts_cnt;
>  	unsigned char			multicast_router;
>  	struct bridge_mcast_stats	__percpu *mcast_stats;
> -	struct timer_list		multicast_router_timer;
>  	struct hlist_head		mglist;
> -	struct hlist_node		rlist;
>  #endif
>  
>  #ifdef CONFIG_SYSFS
> @@ -449,14 +451,16 @@ struct net_bridge {
>  
>  	struct hlist_head		mcast_gc_list;
>  	struct hlist_head		mdb_list;
> -	struct hlist_head		router_list;
>  
> -	struct timer_list		multicast_router_timer;
> +	struct hlist_head		ip4_mc_router_list;
> +	struct timer_list		ip4_mc_router_timer;
>  	struct bridge_mcast_other_query	ip4_other_query;
>  	struct bridge_mcast_own_query	ip4_own_query;
>  	struct bridge_mcast_querier	ip4_querier;
>  	struct bridge_mcast_stats	__percpu *mcast_stats;
>  #if IS_ENABLED(CONFIG_IPV6)
> +	struct hlist_head		ip6_mc_router_list;
> +	struct timer_list		ip6_mc_router_timer;
>  	struct bridge_mcast_other_query	ip6_other_query;
>  	struct bridge_mcast_own_query	ip6_own_query;
>  	struct bridge_mcast_querier	ip6_querier;
> @@ -864,11 +868,39 @@ static inline bool br_group_is_l2(const struct br_ip *group)
>  #define mlock_dereference(X, br) \
>  	rcu_dereference_protected(X, lockdep_is_held(&br->multicast_lock))
>  
> -static inline bool br_multicast_is_router(struct net_bridge *br)
> +static inline bool br_ip4_multicast_is_router(struct net_bridge *br)
>  {
> -	return br->multicast_router == 2 ||
> -	       (br->multicast_router == 1 &&
> -		timer_pending(&br->multicast_router_timer));
> +	return timer_pending(&br->ip4_mc_router_timer);
> +}
> +
> +static inline bool br_ip6_multicast_is_router(struct net_bridge *br)
> +{
> +#if IS_ENABLED(CONFIG_IPV6)
> +	return timer_pending(&br->ip6_mc_router_timer);
> +#else
> +	return false;
> +#endif
> +}
> +
> +static inline bool
> +br_multicast_is_router(struct net_bridge *br, struct sk_buff *skb)
> +{
> +	if (br->multicast_router == 2)
> +		return true;
> +
> +	if (br->multicast_router == 1) {
> +		if (skb) {
> +			if (skb->protocol == htons(ETH_P_IP))
> +				return br_ip4_multicast_is_router(br);
> +			else if (skb->protocol == htons(ETH_P_IPV6))
> +				return br_ip6_multicast_is_router(br);
> +		} else {
> +			return br_ip4_multicast_is_router(br) ||
> +			       br_ip6_multicast_is_router(br);
> +		}
> +	}
> +
> +	return false;
>  }

Please use names instead of values for the router types.

>  
>  static inline bool
> 

Thanks,
 Nik

[PATCH net-next 0/2] net: bridge: split IPv4/v6 mc router state and export for batman-adv

[Linus Lüssing]

Hi,

The following are two patches for the Linux bridge regarding multicast
routers. They are rebased on top of the following fix:
"net: bridge: mcast: fix broken length + header check for MRDv6 Adv." [0]
And should be applied afterwards.

The first one splits the so far combined multicast router state into two
ones, one for IPv4 and one for IPv6, for a more fine-grained detection of
multicast routers. This avoids sending IPv4 multicast packets to an
IPv6-only multicast router and avoids sending IPv6 multicast packets to
an IPv4-only multicast router. This is also in preparation for the
second patch:

The second patch exports this now per protocol family multicast router
state so that batman-adv can then later make full use of the
Multicast Router Discovery (MRD) support in the Linux bridge. The
batman-adv protocol format currently expects separate multicast router
states for IPv4 and IPv6, therefore it depends on the first patch.
batman-adv will then make use of this newly exported functions like
this[1].

Regards, Linus

[0]: https://patchwork.kernel.org/project/netdevbpf/patch/20210425152736.8421-1-linus.luessing@c0d3.blue/
[1]: https://git.open-mesh.org/batman-adv.git/shortlog/refs/heads/linus/multicast-routeable-mrd
     -> https://git.open-mesh.org/batman-adv.git/commit/d4bed3a92427445708baeb1f2d1841c5fb816fd4