net: Add MDB net device operations

Add MDB net device operations that will be invoked by rtnetlink code in
response to received RTM_{NEW,DEL,GET}MDB messages. Subsequent patches
will implement these operations in the bridge and VXLAN drivers.

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

include/linux/netdevice.h

···
  *	Used to add FDB entries to dump requests. Implementers should add
  *	entries to skb and update idx with the number of entries.
  *
+ * int (*ndo_mdb_add)(struct net_device *dev, struct nlattr *tb[],
+ *		      u16 nlmsg_flags, struct netlink_ext_ack *extack);
+ *	Adds an MDB entry to dev.
+ * int (*ndo_mdb_del)(struct net_device *dev, struct nlattr *tb[],
+ *		      struct netlink_ext_ack *extack);
+ *	Deletes the MDB entry from dev.
+ * int (*ndo_mdb_dump)(struct net_device *dev, struct sk_buff *skb,
+ *		       struct netlink_callback *cb);
+ *	Dumps MDB entries from dev. The first argument (marker) in the netlink
+ *	callback is used by core rtnetlink code.
+ *
  * int (*ndo_bridge_setlink)(struct net_device *dev, struct nlmsghdr *nlh,
  *			     u16 flags, struct netlink_ext_ack *extack)
  * int (*ndo_bridge_getlink)(struct sk_buff *skb, u32 pid, u32 seq,
···
 					       const unsigned char *addr,
 					       u16 vid, u32 portid, u32 seq,
 					       struct netlink_ext_ack *extack);
+	int			(*ndo_mdb_add)(struct net_device *dev,
+					       struct nlattr *tb[],
+					       u16 nlmsg_flags,
+					       struct netlink_ext_ack *extack);
+	int			(*ndo_mdb_del)(struct net_device *dev,
+					       struct nlattr *tb[],
+					       struct netlink_ext_ack *extack);
+	int			(*ndo_mdb_dump)(struct net_device *dev,
+						struct sk_buff *skb,
+						struct netlink_callback *cb);
 	int			(*ndo_bridge_setlink)(struct net_device *dev,
 						      struct nlmsghdr *nlh,
 						      u16 flags,