net: bridge: add vlan mcast snooping knob

Add a global knob that controls if vlan multicast snooping is enabled.
The proper contexts (vlan or bridge-wide) will be chosen based on the knob
when processing packets and changing bridge device state. Note that
vlans have their individual mcast snooping enabled by default, but this
knob is needed to turn on bridge vlan snooping. It is disabled by
default. To enable the knob vlan filtering must also be enabled, it
doesn't make sense to have vlan mcast snooping without vlan filtering
since that would lead to inconsistencies. Disabling vlan filtering will
also automatically disable vlan mcast snooping.

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 112 insertions, 31 deletions

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index ef4e7de3f18d..b71772828b23 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -1797,9 +1797,9 @@ void br_multicast_enable_port(struct net_bridge_port *port)
 {
 	struct net_bridge *br = port->br;
 
-	spin_lock(&br->multicast_lock);
+	spin_lock_bh(&br->multicast_lock);
 	__br_multicast_enable_port_ctx(&port->multicast_ctx);
-	spin_unlock(&br->multicast_lock);
+	spin_unlock_bh(&br->multicast_lock);
 }
 
 static void __br_multicast_disable_port_ctx(struct net_bridge_mcast_port *pmctx)
@@ -1827,9 +1827,9 @@ static void __br_multicast_disable_port_ctx(struct net_bridge_mcast_port *pmctx)
 
 void br_multicast_disable_port(struct net_bridge_port *port)
 {
-	spin_lock(&port->br->multicast_lock);
+	spin_lock_bh(&port->br->multicast_lock);
 	__br_multicast_disable_port_ctx(&port->multicast_ctx);
-	spin_unlock(&port->br->multicast_lock);
+	spin_unlock_bh(&port->br->multicast_lock);
 }
 
 static int __grp_src_delete_marked(struct net_bridge_port_group *pg)
@@ -3510,8 +3510,9 @@ static int br_multicast_ipv6_rcv(struct net_bridge_mcast *brmctx,
 }
 #endif
 
-int br_multicast_rcv(struct net_bridge_mcast *brmctx,
-		     struct net_bridge_mcast_port *pmctx,
+int br_multicast_rcv(struct net_bridge_mcast **brmctx,
+		     struct net_bridge_mcast_port **pmctx,
+		     struct net_bridge_vlan *vlan,
 		     struct sk_buff *skb, u16 vid)
 {
 	int ret = 0;
@@ -3519,16 +3520,36 @@ int br_multicast_rcv(struct net_bridge_mcast *brmctx,
 	BR_INPUT_SKB_CB(skb)->igmp = 0;
 	BR_INPUT_SKB_CB(skb)->mrouters_only = 0;
 
-	if (!br_opt_get(brmctx->br, BROPT_MULTICAST_ENABLED))
+	if (!br_opt_get((*brmctx)->br, BROPT_MULTICAST_ENABLED))
 		return 0;
 
+	if (br_opt_get((*brmctx)->br, BROPT_MCAST_VLAN_SNOOPING_ENABLED) && vlan) {
+		const struct net_bridge_vlan *masterv;
+
+		/* the vlan has the master flag set only when transmitting
+		 * through the bridge device
+		 */
+		if (br_vlan_is_master(vlan)) {
+			masterv = vlan;
+			*brmctx = &vlan->br_mcast_ctx;
+			*pmctx = NULL;
+		} else {
+			masterv = vlan->brvlan;
+			*brmctx = &vlan->brvlan->br_mcast_ctx;
+			*pmctx = &vlan->port_mcast_ctx;
+		}
+
+		if (!(masterv->priv_flags & BR_VLFLAG_GLOBAL_MCAST_ENABLED))
+			return 0;
+	}
+
 	switch (skb->protocol) {
 	case htons(ETH_P_IP):
-		ret = br_multicast_ipv4_rcv(brmctx, pmctx, skb, vid);
+		ret = br_multicast_ipv4_rcv(*brmctx, *pmctx, skb, vid);
 		break;
 #if IS_ENABLED(CONFIG_IPV6)
 	case htons(ETH_P_IPV6):
-		ret = br_multicast_ipv6_rcv(brmctx, pmctx, skb, vid);
+		ret = br_multicast_ipv6_rcv(*brmctx, *pmctx, skb, vid);
 		break;
 #endif
 	}
@@ -3727,20 +3748,22 @@ static void __br_multicast_open(struct net_bridge_mcast *brmctx)
 
 void br_multicast_open(struct net_bridge *br)
 {
-	struct net_bridge_vlan_group *vg;
-	struct net_bridge_vlan *vlan;
-
 	ASSERT_RTNL();
 
-	vg = br_vlan_group(br);
-	if (vg) {
-		list_for_each_entry(vlan, &vg->vlan_list, vlist) {
-			struct net_bridge_mcast *brmctx;
-
-			brmctx = &vlan->br_mcast_ctx;
-			if (br_vlan_is_brentry(vlan) &&
-			    !br_multicast_ctx_vlan_disabled(brmctx))
-				__br_multicast_open(&vlan->br_mcast_ctx);
+	if (br_opt_get(br, BROPT_MCAST_VLAN_SNOOPING_ENABLED)) {
+		struct net_bridge_vlan_group *vg;
+		struct net_bridge_vlan *vlan;
+
+		vg = br_vlan_group(br);
+		if (vg) {
+			list_for_each_entry(vlan, &vg->vlan_list, vlist) {
+				struct net_bridge_mcast *brmctx;
+
+				brmctx = &vlan->br_mcast_ctx;
+				if (br_vlan_is_brentry(vlan) &&
+				    !br_multicast_ctx_vlan_disabled(brmctx))
+					__br_multicast_open(&vlan->br_mcast_ctx);
+			}
 		}
 	}
 
@@ -3804,22 +3827,80 @@ void br_multicast_toggle_one_vlan(struct net_bridge_vlan *vlan, bool on)
 	}
 }
 
-void br_multicast_stop(struct net_bridge *br)
+void br_multicast_toggle_vlan(struct net_bridge_vlan *vlan, bool on)
+{
+	struct net_bridge_port *p;
+
+	if (WARN_ON_ONCE(!br_vlan_is_master(vlan)))
+		return;
+
+	list_for_each_entry(p, &vlan->br->port_list, list) {
+		struct net_bridge_vlan *vport;
+
+		vport = br_vlan_find(nbp_vlan_group(p), vlan->vid);
+		if (!vport)
+			continue;
+		br_multicast_toggle_one_vlan(vport, on);
+	}
+}
+
+int br_multicast_toggle_vlan_snooping(struct net_bridge *br, bool on,
+				      struct netlink_ext_ack *extack)
 {
 	struct net_bridge_vlan_group *vg;
 	struct net_bridge_vlan *vlan;
+	struct net_bridge_port *p;
 
-	ASSERT_RTNL();
+	if (br_opt_get(br, BROPT_MCAST_VLAN_SNOOPING_ENABLED) == on)
+		return 0;
+
+	if (on && !br_opt_get(br, BROPT_VLAN_ENABLED)) {
+		NL_SET_ERR_MSG_MOD(extack, "Cannot enable multicast vlan snooping with vlan filtering disabled");
+		return -EINVAL;
+	}
 
 	vg = br_vlan_group(br);
-	if (vg) {
-		list_for_each_entry(vlan, &vg->vlan_list, vlist) {
-			struct net_bridge_mcast *brmctx;
-
-			brmctx = &vlan->br_mcast_ctx;
-			if (br_vlan_is_brentry(vlan) &&
-			    !br_multicast_ctx_vlan_disabled(brmctx))
-				__br_multicast_stop(&vlan->br_mcast_ctx);
+	if (!vg)
+		return 0;
+
+	br_opt_toggle(br, BROPT_MCAST_VLAN_SNOOPING_ENABLED, on);
+
+	/* disable/enable non-vlan mcast contexts based on vlan snooping */
+	if (on)
+		__br_multicast_stop(&br->multicast_ctx);
+	else
+		__br_multicast_open(&br->multicast_ctx);
+	list_for_each_entry(p, &br->port_list, list) {
+		if (on)
+			br_multicast_disable_port(p);
+		else
+			br_multicast_enable_port(p);
+	}
+
+	list_for_each_entry(vlan, &vg->vlan_list, vlist)
+		br_multicast_toggle_vlan(vlan, on);
+
+	return 0;
+}
+
+void br_multicast_stop(struct net_bridge *br)
+{
+	ASSERT_RTNL();
+
+	if (br_opt_get(br, BROPT_MCAST_VLAN_SNOOPING_ENABLED)) {
+		struct net_bridge_vlan_group *vg;
+		struct net_bridge_vlan *vlan;
+
+		vg = br_vlan_group(br);
+		if (vg) {
+			list_for_each_entry(vlan, &vg->vlan_list, vlist) {
+				struct net_bridge_mcast *brmctx;
+
+				brmctx = &vlan->br_mcast_ctx;
+				if (br_vlan_is_brentry(vlan) &&
+				    !br_multicast_ctx_vlan_disabled(brmctx))
+					__br_multicast_stop(&vlan->br_mcast_ctx);
+			}
 		}
 	}