rtnetlink: Link address family API
Each net_device contains address family specific data such as
per device settings and statistics. We already expose this data
via procfs/sysfs and partially netlink.
The netlink method requires the requester to send one RTM_GETLINK
request for each address family it wishes to receive data of
and then merge this data itself.
This patch implements a new API which combines all address family
specific link data in a new netlink attribute IFLA_AF_SPEC.
IFLA_AF_SPEC contains a sequence of nested attributes, one for each
address family which in turn defines the structure of its own
attribute. Example:
[IFLA_AF_SPEC] = {
[AF_INET] = {
[IFLA_INET_CONF] = ...,
},
[AF_INET6] = {
[IFLA_INET6_FLAGS] = ...,
[IFLA_INET6_CONF] = ...,
}
}
The API also allows for address families to implement a function
which parses the IFLA_AF_SPEC attribute sent by userspace to
implement address family specific link options.
Signed-off-by: Thomas Graf <tgraf@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index e013c68..35be0bb 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -83,6 +83,37 @@
extern int rtnl_link_register(struct rtnl_link_ops *ops);
extern void rtnl_link_unregister(struct rtnl_link_ops *ops);
+/**
+ * struct rtnl_af_ops - rtnetlink address family operations
+ *
+ * @list: Used internally
+ * @family: Address family
+ * @fill_link_af: Function to fill IFLA_AF_SPEC with address family
+ * specific netlink attributes.
+ * @get_link_af_size: Function to calculate size of address family specific
+ * netlink attributes exlusive the container attribute.
+ * @parse_link_af: Function to parse a IFLA_AF_SPEC attribute and modify
+ * net_device accordingly.
+ */
+struct rtnl_af_ops {
+ struct list_head list;
+ int family;
+
+ int (*fill_link_af)(struct sk_buff *skb,
+ const struct net_device *dev);
+ size_t (*get_link_af_size)(const struct net_device *dev);
+
+ int (*parse_link_af)(struct net_device *dev,
+ const struct nlattr *attr);
+};
+
+extern int __rtnl_af_register(struct rtnl_af_ops *ops);
+extern void __rtnl_af_unregister(struct rtnl_af_ops *ops);
+
+extern int rtnl_af_register(struct rtnl_af_ops *ops);
+extern void rtnl_af_unregister(struct rtnl_af_ops *ops);
+
+
extern struct net *rtnl_link_get_net(struct net *src_net, struct nlattr *tb[]);
extern struct net_device *rtnl_create_link(struct net *src_net, struct net *net,
char *ifname, const struct rtnl_link_ops *ops, struct nlattr *tb[]);