tipc: introduce ioctl for fetching node identity

After the introduction of a 128-bit node identity it may be difficult
for a user to correlate between this identity and the generated node
hash address.

We now try to make this easier by introducing a new ioctl() call for
fetching a node identity by using the hash value as key. This will
be particularly useful when we extend some of the commands in the
'tipc' tool, but we also expect regular user applications to need
this feature.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/uapi/linux/tipc.h b/include/uapi/linux/tipc.h
index bf6d286..6b2fd4d 100644
--- a/include/uapi/linux/tipc.h
+++ b/include/uapi/linux/tipc.h
@@ -209,16 +209,16 @@ struct tipc_group_req {
  * The string formatting for each name element is:
  * media: media
  * interface: media:interface name
- * link: Z.C.N:interface-Z.C.N:interface
- *
+ * link: node:interface-node:interface
  */
-
+#define TIPC_NODEID_LEN         16
 #define TIPC_MAX_MEDIA_NAME	16
 #define TIPC_MAX_IF_NAME	16
 #define TIPC_MAX_BEARER_NAME	32
 #define TIPC_MAX_LINK_NAME	68
 
-#define SIOCGETLINKNAME		SIOCPROTOPRIVATE
+#define SIOCGETLINKNAME        SIOCPROTOPRIVATE
+#define SIOCGETNODEID          (SIOCPROTOPRIVATE + 1)
 
 struct tipc_sioc_ln_req {
 	__u32 peer;
@@ -226,6 +226,10 @@ struct tipc_sioc_ln_req {
 	char linkname[TIPC_MAX_LINK_NAME];
 };
 
+struct tipc_sioc_nodeid_req {
+	__u32 peer;
+	char node_id[TIPC_NODEID_LEN];
+};
 
 /* The macros and functions below are deprecated:
  */