net: bridge: mst: Support setting and reporting MST port states

Make it possible to change the port state in a given MSTI by extending
the bridge port netlink interface (RTM_SETLINK on PF_BRIDGE).The
proposed iproute2 interface would be:

    bridge mst set dev <PORT> msti <MSTI> state <STATE>

Current states in all applicable MSTIs can also be dumped via a
corresponding RTM_GETLINK. The proposed iproute interface looks like
this:

$ bridge mst
port              msti
vb1               0
		    state forwarding
		  100
		    state disabled
vb2               0
		    state forwarding
		  100
		    state forwarding

The preexisting per-VLAN states are still valid in the MST
mode (although they are read-only), and can be queried as usual if one
is interested in knowing a particular VLAN's state without having to
care about the VID to MSTI mapping (in this example VLAN 20 and 30 are
bound to MSTI 100):

$ bridge -d vlan
port              vlan-id
vb1               10
		    state forwarding mcast_router 1
		  20
		    state disabled mcast_router 1
		  30
		    state disabled mcast_router 1
		  40
		    state forwarding mcast_router 1
vb2               10
		    state forwarding mcast_router 1
		  20
		    state forwarding mcast_router 1
		  30
		    state forwarding mcast_router 1
		  40
		    state forwarding mcast_router 1

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 3978e1d9ffb5..18ccc3d5d296 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -1784,6 +1784,11 @@ int br_mst_vlan_set_msti(struct net_bridge_vlan *v, u16 msti);
 void br_mst_vlan_init_state(struct net_bridge_vlan *v);
 int br_mst_set_enabled(struct net_bridge *br, bool on,
 		       struct netlink_ext_ack *extack);
+size_t br_mst_info_size(const struct net_bridge_vlan_group *vg);
+int br_mst_fill_info(struct sk_buff *skb,
+		     const struct net_bridge_vlan_group *vg);
+int br_mst_process(struct net_bridge_port *p, const struct nlattr *mst_attr,
+		   struct netlink_ext_ack *extack);
 #else
 static inline bool br_mst_is_enabled(struct net_bridge *br)
 {
@@ -1801,6 +1806,24 @@ static inline int br_mst_set_enabled(struct net_bridge *br, bool on,
 {
 	return -EOPNOTSUPP;
 }
+
+static inline size_t br_mst_info_size(const struct net_bridge_vlan_group *vg)
+{
+	return 0;
+}
+
+static inline int br_mst_fill_info(struct sk_buff *skb,
+				   const struct net_bridge_vlan_group *vg)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int br_mst_process(struct net_bridge_port *p,
+				 const struct nlattr *mst_attr,
+				 struct netlink_ext_ack *extack)
+{
+	return -EOPNOTSUPP;
+}
 #endif
 
 struct nf_br_ops {