[RTNETLINK]: Link creation API

Add rtnetlink API for creating, changing and deleting software devices.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/if_link.h

@@ -76,6 +76,8 @@ enum
 #define IFLA_WEIGHT IFLA_WEIGHT
 	IFLA_OPERSTATE,
 	IFLA_LINKMODE,
+	IFLA_LINKINFO,
+#define IFLA_LINKINFO IFLA_LINKINFO
 	__IFLA_MAX
 };
 
@@ -140,4 +142,15 @@ struct ifla_cacheinfo
 	__u32	retrans_time;
 };
 
+enum
+{
+	IFLA_INFO_UNSPEC,
+	IFLA_INFO_KIND,
+	IFLA_INFO_DATA,
+	IFLA_INFO_XSTATS,
+	__IFLA_INFO_MAX,
+};
+
+#define IFLA_INFO_MAX	(__IFLA_INFO_MAX - 1)
+
 #endif /* _LINUX_IF_LINK_H */

include/linux/netdevice.h

@@ -540,6 +540,9 @@ struct net_device
 	struct device		dev;
 	/* space for optional statistics and wireless sysfs groups */
 	struct attribute_group  *sysfs_groups[3];
+
+	/* rtnetlink link ops */
+	const struct rtnl_link_ops *rtnl_link_ops;
 };
 #define to_net_dev(d) container_of(d, struct net_device, dev)
 

include/net/rtnetlink.h

@@ -22,4 +22,62 @@ static inline int rtnl_msg_family(struct nlmsghdr *nlh)
 		return AF_UNSPEC;
 }
 
+/**
+ *	struct rtnl_link_ops - rtnetlink link operations
+ *
+ *	@list: Used internally
+ *	@kind: Identifier
+ *	@maxtype: Highest device specific netlink attribute number
+ *	@policy: Netlink policy for device specific attribute validation
+ *	@validate: Optional validation function for netlink/changelink parameters
+ *	@priv_size: sizeof net_device private space
+ *	@setup: net_device setup function
+ *	@newlink: Function for configuring and registering a new device
+ *	@changelink: Function for changing parameters of an existing device
+ *	@dellink: Function to remove a device
+ *	@get_size: Function to calculate required room for dumping device
+ *		   specific netlink attributes
+ *	@fill_info: Function to dump device specific netlink attributes
+ *	@get_xstats_size: Function to calculate required room for dumping devic
+ *			  specific statistics
+ *	@fill_xstats: Function to dump device specific statistics
+ */
+struct rtnl_link_ops {
+	struct list_head	list;
+
+	const char		*kind;
+
+	size_t			priv_size;
+	void			(*setup)(struct net_device *dev);
+
+	int			maxtype;
+	const struct nla_policy	*policy;
+	int			(*validate)(struct nlattr *tb[],
+					    struct nlattr *data[]);
+
+	int			(*newlink)(struct net_device *dev,
+					   struct nlattr *tb[],
+					   struct nlattr *data[]);
+	int			(*changelink)(struct net_device *dev,
+					      struct nlattr *tb[],
+					      struct nlattr *data[]);
+	void			(*dellink)(struct net_device *dev);
+
+	size_t			(*get_size)(const struct net_device *dev);
+	int			(*fill_info)(struct sk_buff *skb,
+					     const struct net_device *dev);
+
+	size_t			(*get_xstats_size)(const struct net_device *dev);
+	int			(*fill_xstats)(struct sk_buff *skb,
+					       const struct net_device *dev);
+};
+
+extern int	__rtnl_link_register(struct rtnl_link_ops *ops);
+extern void	__rtnl_link_unregister(struct rtnl_link_ops *ops);
+
+extern int	rtnl_link_register(struct rtnl_link_ops *ops);
+extern void	rtnl_link_unregister(struct rtnl_link_ops *ops);
+
+#define MODULE_ALIAS_RTNL_LINK(kind) MODULE_ALIAS("rtnl-link-" kind)
+
 #endif