bridge: vlan: Allow setting VLAN neighbor suppression state

Add a new VLAN attribute that allows user space to set the neighbor
suppression state of the port VLAN. Example:

# bridge -d -j -p vlan show dev swp1 vid 10 | jq '.[]["vlans"][]["neigh_suppress"]'
false
# bridge vlan set vid 10 dev swp1 neigh_suppress on
# bridge -d -j -p vlan show dev swp1 vid 10 | jq '.[]["vlans"][]["neigh_suppress"]'
true
# bridge vlan set vid 10 dev swp1 neigh_suppress off
# bridge -d -j -p vlan show dev swp1 vid 10 | jq '.[]["vlans"][]["neigh_suppress"]'
false

# bridge vlan set vid 10 dev br0 neigh_suppress on
Error: bridge: Can't set neigh_suppress for non-port vlans.

Signed-off-by: Ido Schimmel <[e-mail]>
Acked-by: Nikolay Aleksandrov <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/uapi/linux/if_bridge.h

···
 	BRIDGE_VLANDB_ENTRY_MCAST_ROUTER,
 	BRIDGE_VLANDB_ENTRY_MCAST_N_GROUPS,
 	BRIDGE_VLANDB_ENTRY_MCAST_MAX_GROUPS,
+	BRIDGE_VLANDB_ENTRY_NEIGH_SUPPRESS,
 	__BRIDGE_VLANDB_ENTRY_MAX,
 };
 #define BRIDGE_VLANDB_ENTRY_MAX (__BRIDGE_VLANDB_ENTRY_MAX - 1)

net/bridge/br_vlan.c

···
 	[BRIDGE_VLANDB_ENTRY_MCAST_ROUTER]	= { .type = NLA_U8 },
 	[BRIDGE_VLANDB_ENTRY_MCAST_N_GROUPS]	= { .type = NLA_REJECT },
 	[BRIDGE_VLANDB_ENTRY_MCAST_MAX_GROUPS]	= { .type = NLA_U32 },
+	[BRIDGE_VLANDB_ENTRY_NEIGH_SUPPRESS]	= NLA_POLICY_MAX(NLA_U8, 1),
 };
 
 static int br_vlan_rtm_process_one(struct net_device *dev,

net/bridge/br_vlan_options.c

···
 		       const struct net_bridge_port *p)
 {
 	if (nla_put_u8(skb, BRIDGE_VLANDB_ENTRY_STATE, br_vlan_get_state(v)) ||
-	    !__vlan_tun_put(skb, v))
+	    !__vlan_tun_put(skb, v) ||
+	    nla_put_u8(skb, BRIDGE_VLANDB_ENTRY_NEIGH_SUPPRESS,
+		       !!(v->priv_flags & BR_VLFLAG_NEIGH_SUPPRESS_ENABLED)))
 		return false;
 
 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
···
 	       + nla_total_size(sizeof(u32)) /* BRIDGE_VLANDB_ENTRY_MCAST_N_GROUPS */
 	       + nla_total_size(sizeof(u32)) /* BRIDGE_VLANDB_ENTRY_MCAST_MAX_GROUPS */
 #endif
+	       + nla_total_size(sizeof(u8)) /* BRIDGE_VLANDB_ENTRY_NEIGH_SUPPRESS */
 	       + 0;
 }
 
···
 		*changed = true;
 	}
 #endif
+
+	if (tb[BRIDGE_VLANDB_ENTRY_NEIGH_SUPPRESS]) {
+		bool enabled = v->priv_flags & BR_VLFLAG_NEIGH_SUPPRESS_ENABLED;
+		bool val = nla_get_u8(tb[BRIDGE_VLANDB_ENTRY_NEIGH_SUPPRESS]);
+
+		if (!p) {
+			NL_SET_ERR_MSG_MOD(extack, "Can't set neigh_suppress for non-port vlans");
+			return -EINVAL;
+		}
+
+		if (val != enabled) {
+			v->priv_flags ^= BR_VLFLAG_NEIGH_SUPPRESS_ENABLED;
+			*changed = true;
+		}
+	}
 
 	return 0;
 }