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>

include/uapi/linux/if_link.h

@@ -525,6 +525,8 @@ enum {
 	IFLA_BRPORT_BACKUP_PORT,
 	IFLA_BRPORT_MRP_RING_OPEN,
 	IFLA_BRPORT_MRP_IN_OPEN,
+	IFLA_BRPORT_MCAST_EHT_HOSTS_LIMIT,
+	IFLA_BRPORT_MCAST_EHT_HOSTS_CNT,
 	__IFLA_BRPORT_MAX
 };
 #define IFLA_BRPORT_MAX (__IFLA_BRPORT_MAX - 1)

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;
+}

net/bridge/br_netlink.c

@@ -18,6 +18,7 @@
 #include "br_private_stp.h"
 #include "br_private_cfm.h"
 #include "br_private_tunnel.h"
+#include "br_private_mcast_eht.h"
 
 static int __get_num_vlan_infos(struct net_bridge_vlan_group *vg,
 				u32 filter_mask)
@@ -199,6 +200,8 @@ static inline size_t br_port_info_size(void)
 		+ nla_total_size(sizeof(u16))	/* IFLA_BRPORT_GROUP_FWD_MASK */
 		+ nla_total_size(sizeof(u8))	/* IFLA_BRPORT_MRP_RING_OPEN */
 		+ nla_total_size(sizeof(u8))	/* IFLA_BRPORT_MRP_IN_OPEN */
+		+ nla_total_size(sizeof(u32))	/* IFLA_BRPORT_MCAST_EHT_HOSTS_LIMIT */
+		+ nla_total_size(sizeof(u32))	/* IFLA_BRPORT_MCAST_EHT_HOSTS_CNT */
 		+ 0;
 }
 
@@ -283,7 +286,11 @@ static int br_port_fill_attrs(struct sk_buff *skb,
 
 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
 	if (nla_put_u8(skb, IFLA_BRPORT_MULTICAST_ROUTER,
-		       p->multicast_router))
+		       p->multicast_router) ||
+	    nla_put_u32(skb, IFLA_BRPORT_MCAST_EHT_HOSTS_LIMIT,
+			p->multicast_eht_hosts_limit) ||
+	    nla_put_u32(skb, IFLA_BRPORT_MCAST_EHT_HOSTS_CNT,
+			p->multicast_eht_hosts_cnt))
 		return -EMSGSIZE;
 #endif
 
@@ -820,6 +827,7 @@ static const struct nla_policy br_port_policy[IFLA_BRPORT_MAX + 1] = {
 	[IFLA_BRPORT_NEIGH_SUPPRESS] = { .type = NLA_U8 },
 	[IFLA_BRPORT_ISOLATED]	= { .type = NLA_U8 },
 	[IFLA_BRPORT_BACKUP_PORT] = { .type = NLA_U32 },
+	[IFLA_BRPORT_MCAST_EHT_HOSTS_LIMIT] = { .type = NLA_U32 },
 };
 
 /* Change the state of the port and notify spanning tree */
@@ -955,6 +963,15 @@ static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
 		if (err)
 			return err;
 	}
+
+	if (tb[IFLA_BRPORT_MCAST_EHT_HOSTS_LIMIT]) {
+		u32 hlimit;
+
+		hlimit = nla_get_u32(tb[IFLA_BRPORT_MCAST_EHT_HOSTS_LIMIT]);
+		err = br_multicast_eht_set_hosts_limit(p, hlimit);
+		if (err)
+			return err;
+	}
 #endif
 
 	if (tb[IFLA_BRPORT_GROUP_FWD_MASK]) {

net/bridge/br_private_mcast_eht.h

@@ -57,6 +57,8 @@ bool br_multicast_eht_handle(struct net_bridge_port_group *pg,
 			     u32 nsrcs,
 			     size_t addr_size,
 			     int grec_type);
+int br_multicast_eht_set_hosts_limit(struct net_bridge_port *p,
+				     u32 eht_hosts_limit);
 
 static inline bool
 br_multicast_eht_should_del_pg(const struct net_bridge_port_group *pg)

net/bridge/br_sysfs_if.c

@@ -16,6 +16,7 @@
 #include <linux/sched/signal.h>
 
 #include "br_private.h"
+#include "br_private_mcast_eht.h"
 
 struct brport_attribute {
 	struct attribute	attr;
@@ -245,6 +246,29 @@ static int store_multicast_router(struct net_bridge_port *p,
 static BRPORT_ATTR(multicast_router, 0644, show_multicast_router,
 		   store_multicast_router);
 
+static ssize_t show_multicast_eht_hosts_limit(struct net_bridge_port *p,
+					      char *buf)
+{
+	return sprintf(buf, "%u\n", p->multicast_eht_hosts_limit);
+}
+
+static int store_multicast_eht_hosts_limit(struct net_bridge_port *p,
+					   unsigned long v)
+{
+	return br_multicast_eht_set_hosts_limit(p, v);
+}
+static BRPORT_ATTR(multicast_eht_hosts_limit, 0644,
+		   show_multicast_eht_hosts_limit,
+		   store_multicast_eht_hosts_limit);
+
+static ssize_t show_multicast_eht_hosts_cnt(struct net_bridge_port *p,
+					    char *buf)
+{
+	return sprintf(buf, "%u\n", p->multicast_eht_hosts_cnt);
+}
+static BRPORT_ATTR(multicast_eht_hosts_cnt, 0444, show_multicast_eht_hosts_cnt,
+		   NULL);
+
 BRPORT_ATTR_FLAG(multicast_fast_leave, BR_MULTICAST_FAST_LEAVE);
 BRPORT_ATTR_FLAG(multicast_to_unicast, BR_MULTICAST_TO_UNICAST);
 #endif
@@ -274,6 +298,8 @@ static const struct brport_attribute *brport_attrs[] = {
 	&brport_attr_multicast_router,
 	&brport_attr_multicast_fast_leave,
 	&brport_attr_multicast_to_unicast,
+	&brport_attr_multicast_eht_hosts_limit,
+	&brport_attr_multicast_eht_hosts_cnt,
 #endif
 	&brport_attr_proxyarp,
 	&brport_attr_proxyarp_wifi,

net/core/rtnetlink.c

@@ -55,7 +55,7 @@
 #include <net/net_namespace.h>
 
 #define RTNL_MAX_TYPE		50
-#define RTNL_SLAVE_MAX_TYPE	36
+#define RTNL_SLAVE_MAX_TYPE	40
 
 struct rtnl_link {
 	rtnl_doit_func		doit;