net: add an ioctl to get a socket network namespace
Each socket operates in a network namespace where it has been created,
so if we want to dump and restore a socket, we have to know its network
namespace.
We have a socket_diag to get information about sockets, it doesn't
report sockets which are not bound or connected.
This patch introduces a new socket ioctl, which is called SIOCGSKNS
and used to get a file descriptor for a socket network namespace.
A task must have CAP_NET_ADMIN in a target network namespace to
use this ioctl.
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index b97bf2e..368c7ad 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -82,4 +82,8 @@ static inline struct proc_dir_entry *proc_net_mkdir(
return proc_mkdir_data(name, 0, parent, net);
}
+struct ns_common;
+int open_related_ns(struct ns_common *ns,
+ struct ns_common *(*get_ns)(struct ns_common *ns));
+
#endif /* _LINUX_PROC_FS_H */
diff --git a/include/uapi/linux/sockios.h b/include/uapi/linux/sockios.h
index 8e7890b..83cc54c 100644
--- a/include/uapi/linux/sockios.h
+++ b/include/uapi/linux/sockios.h
@@ -84,6 +84,7 @@
#define SIOCWANDEV 0x894A /* get/set netdev parameters */
#define SIOCOUTQNSD 0x894B /* output queue size (not sent only) */
+#define SIOCGSKNS 0x894C /* get socket network namespace */
/* ARP cache control calls. */
/* 0x8950 - 0x8952 * obsolete calls, don't re-use */