net: bridge: multicast: make tracked EHT hosts limit configurable

Add two new port attributes which make EHT hosts limit configurable and
export the current number of tracked EHT hosts:
 - IFLA_BRPORT_MCAST_EHT_HOSTS_LIMIT: configure/retrieve current limit
 - IFLA_BRPORT_MCAST_EHT_HOSTS_CNT: current number of tracked hosts
Setting IFLA_BRPORT_MCAST_EHT_HOSTS_LIMIT to 0 is currently not allowed.

Note that we have to increase RTNL_SLAVE_MAX_TYPE to 38 minimum, I've
increased it to 40 to have space for two more future entries.

v2: move br_multicast_eht_set_hosts_limit() to br_multicast_eht.c,
    no functional change

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/net/bridge/br_multicast_eht.c b/net/bridge/br_multicast_eht.c
index 445768c8495f..fea38b9a7268 100644
--- a/net/bridge/br_multicast_eht.c
+++ b/net/bridge/br_multicast_eht.c
@@ -861,3 +861,18 @@ bool br_multicast_eht_handle(struct net_bridge_port_group *pg,
 out:
 	return changed;
 }
+
+int br_multicast_eht_set_hosts_limit(struct net_bridge_port *p,
+				     u32 eht_hosts_limit)
+{
+	struct net_bridge *br = p->br;
+
+	if (!eht_hosts_limit)
+		return -EINVAL;
+
+	spin_lock_bh(&br->multicast_lock);
+	p->multicast_eht_hosts_limit = eht_hosts_limit;
+	spin_unlock_bh(&br->multicast_lock);
+
+	return 0;
+}