net: bridge: Add extack to br_multicast_new_port_group()

Make it possible to set an extack in br_multicast_new_port_group().
Eventually, this function will check for per-port and per-port-vlan
MDB maximums, and will use the extack to communicate the reason for
the bounce.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_mdb.c

@@ -849,7 +849,7 @@ static int br_mdb_add_group_sg(const struct br_mdb_config *cfg,
 	}
 
 	p = br_multicast_new_port_group(cfg->p, &cfg->group, *pp, flags, NULL,
-					MCAST_INCLUDE, cfg->rt_protocol);
+					MCAST_INCLUDE, cfg->rt_protocol, extack);
 	if (unlikely(!p)) {
 		NL_SET_ERR_MSG_MOD(extack, "Couldn't allocate new (S, G) port group");
 		return -ENOMEM;
@@ -1075,7 +1075,8 @@ static int br_mdb_add_group_star_g(const struct br_mdb_config *cfg,
 	}
 
 	p = br_multicast_new_port_group(cfg->p, &cfg->group, *pp, flags, NULL,
-					cfg->filter_mode, cfg->rt_protocol);
+					cfg->filter_mode, cfg->rt_protocol,
+					extack);
 	if (unlikely(!p)) {
 		NL_SET_ERR_MSG_MOD(extack, "Couldn't allocate new (*, G) port group");
 		return -ENOMEM;

net/bridge/br_multicast.c

@@ -1284,7 +1284,8 @@ struct net_bridge_port_group *br_multicast_new_port_group(
 			unsigned char flags,
 			const unsigned char *src,
 			u8 filter_mode,
-			u8 rt_protocol)
+			u8 rt_protocol,
+			struct netlink_ext_ack *extack)
 {
 	struct net_bridge_port_group *p;
 
@@ -1387,7 +1388,7 @@ __br_multicast_add_group(struct net_bridge_mcast *brmctx,
 	}
 
 	p = br_multicast_new_port_group(pmctx->port, group, *pp, 0, src,
-					filter_mode, RTPROT_KERNEL);
+					filter_mode, RTPROT_KERNEL, NULL);
 	if (unlikely(!p)) {
 		p = ERR_PTR(-ENOMEM);
 		goto out;

net/bridge/br_private.h

@@ -956,7 +956,8 @@ br_multicast_new_port_group(struct net_bridge_port *port,
 			    const struct br_ip *group,
 			    struct net_bridge_port_group __rcu *next,
 			    unsigned char flags, const unsigned char *src,
-			    u8 filter_mode, u8 rt_protocol);
+			    u8 filter_mode, u8 rt_protocol,
+			    struct netlink_ext_ack *extack);
 int br_mdb_hash_init(struct net_bridge *br);
 void br_mdb_hash_fini(struct net_bridge *br);
 void br_mdb_notify(struct net_device *dev, struct net_bridge_mdb_entry *mp,