[NET]: Implement the per network namespace sysctl infrastructure

The user interface is: register_net_sysctl_table and
unregister_net_sysctl_table.  Very much like the current
interface except there is a network namespace parameter.

With this any sysctl registered with register_net_sysctl_table
will only show up to tasks in the same network namespace.

All other sysctls continue to be globally visible.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Daniel Lezcano <dlezcano@fr.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 4d0d6349aa7e..235214c4c231 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -25,6 +25,8 @@ struct net {
         struct proc_dir_entry   *proc_net_stat;
         struct proc_dir_entry   *proc_net_root;
 
+        struct list_head        sysctl_table_headers;
+
         struct net_device       *loopback_dev;          /* The loopback */
 
         struct list_head        dev_base_head;
@@ -144,4 +146,11 @@ extern void unregister_pernet_subsys(struct pernet_operations *);
 extern int register_pernet_device(struct pernet_operations *);
 extern void unregister_pernet_device(struct pernet_operations *);
 
+struct ctl_path;
+struct ctl_table;
+struct ctl_table_header;
+extern struct ctl_table_header *register_net_sysctl_table(struct net *net,
+        const struct ctl_path *path, struct ctl_table *table);
+extern void unregister_net_sysctl_table(struct ctl_table_header *header);
+
 #endif /* __NET_NET_NAMESPACE_H */