net: bridge: vlan: add support for mcast last member count global option

Add support to change and retrieve global vlan multicast last member
count option.
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/if_bridge.h

@@ -551,6 +551,7 @@ enum {
 	BRIDGE_VLANDB_GOPTS_MCAST_SNOOPING,
 	BRIDGE_VLANDB_GOPTS_MCAST_IGMP_VERSION,
 	BRIDGE_VLANDB_GOPTS_MCAST_MLD_VERSION,
+	BRIDGE_VLANDB_GOPTS_MCAST_LAST_MEMBER_CNT,
 	__BRIDGE_VLANDB_GOPTS_MAX
 };
 #define BRIDGE_VLANDB_GOPTS_MAX (__BRIDGE_VLANDB_GOPTS_MAX - 1)

net/bridge/br_private.h

@@ -1174,6 +1174,8 @@ br_multicast_ctx_options_equal(const struct net_bridge_mcast *brmctx1,
 {
 	return brmctx1->multicast_igmp_version ==
 	       brmctx2->multicast_igmp_version &&
+	       brmctx1->multicast_last_member_count ==
+	       brmctx2->multicast_last_member_count &&
 #if IS_ENABLED(CONFIG_IPV6)
 	       brmctx1->multicast_mld_version ==
 	       brmctx2->multicast_mld_version &&

net/bridge/br_vlan_options.c

@@ -289,7 +289,9 @@ bool br_vlan_global_opts_fill(struct sk_buff *skb, u16 vid, u16 vid_range,
 	if (nla_put_u8(skb, BRIDGE_VLANDB_GOPTS_MCAST_SNOOPING,
 		       !!(v_opts->priv_flags & BR_VLFLAG_GLOBAL_MCAST_ENABLED)) ||
 	    nla_put_u8(skb, BRIDGE_VLANDB_GOPTS_MCAST_IGMP_VERSION,
-		       v_opts->br_mcast_ctx.multicast_igmp_version))
+		       v_opts->br_mcast_ctx.multicast_igmp_version) ||
+	    nla_put_u32(skb, BRIDGE_VLANDB_GOPTS_MCAST_LAST_MEMBER_CNT,
+			v_opts->br_mcast_ctx.multicast_last_member_count))
 		goto out_err;
 
 #if IS_ENABLED(CONFIG_IPV6)
@@ -317,6 +319,7 @@ static size_t rtnl_vlan_global_opts_nlmsg_size(void)
 		+ nla_total_size(sizeof(u8)) /* BRIDGE_VLANDB_GOPTS_MCAST_SNOOPING */
 		+ nla_total_size(sizeof(u8)) /* BRIDGE_VLANDB_GOPTS_MCAST_IGMP_VERSION */
 		+ nla_total_size(sizeof(u8)) /* BRIDGE_VLANDB_GOPTS_MCAST_MLD_VERSION */
+		+ nla_total_size(sizeof(u32)) /* BRIDGE_VLANDB_GOPTS_MCAST_LAST_MEMBER_CNT */
 #endif
 		+ nla_total_size(sizeof(u16)); /* BRIDGE_VLANDB_GOPTS_RANGE */
 }
@@ -391,6 +394,13 @@ static int br_vlan_process_global_one_opts(const struct net_bridge *br,
 			return err;
 		*changed = true;
 	}
+	if (tb[BRIDGE_VLANDB_GOPTS_MCAST_LAST_MEMBER_CNT]) {
+		u32 cnt;
+
+		cnt = nla_get_u32(tb[BRIDGE_VLANDB_GOPTS_MCAST_LAST_MEMBER_CNT]);
+		v->br_mcast_ctx.multicast_last_member_count = cnt;
+		*changed = true;
+	}
 #if IS_ENABLED(CONFIG_IPV6)
 	if (tb[BRIDGE_VLANDB_GOPTS_MCAST_MLD_VERSION]) {
 		u8 ver;
@@ -413,6 +423,7 @@ static const struct nla_policy br_vlan_db_gpol[BRIDGE_VLANDB_GOPTS_MAX + 1] = {
 	[BRIDGE_VLANDB_GOPTS_MCAST_SNOOPING]	= { .type = NLA_U8 },
 	[BRIDGE_VLANDB_GOPTS_MCAST_MLD_VERSION]	= { .type = NLA_U8 },
 	[BRIDGE_VLANDB_GOPTS_MCAST_IGMP_VERSION]	= { .type = NLA_U8 },
+	[BRIDGE_VLANDB_GOPTS_MCAST_LAST_MEMBER_CNT]	= { .type = NLA_U32 },
 };
 
 int br_vlan_rtm_process_global_options(struct net_device *dev,