diag: warn about missing first netlink attribute

The first netlink attribute (value 0) must always be defined as none/unspec.
This is correctly done in inet_diag.h, but other diag interfaces are wrong.

Because we cannot change an existing API, I add a comment to point the mistake
and avoid to propagate it in a new diag API in the future.

CC: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 3 insertions, 0 deletions

diff --git a/include/uapi/linux/netlink_diag.h b/include/uapi/linux/netlink_diag.h
index 4e31db4eea41..f2159d30d1f5 100644
--- a/include/uapi/linux/netlink_diag.h
+++ b/include/uapi/linux/netlink_diag.h
@@ -33,6 +33,7 @@ struct netlink_diag_ring {
 };
 
 enum {
+        /* NETLINK_DIAG_NONE, standard nl API requires this attribute!  */
         NETLINK_DIAG_MEMINFO,
         NETLINK_DIAG_GROUPS,
         NETLINK_DIAG_RX_RING,
diff --git a/include/uapi/linux/packet_diag.h b/include/uapi/linux/packet_diag.h
index b2cc0cd9c4d9..d08c63f3dd6f 100644
--- a/include/uapi/linux/packet_diag.h
+++ b/include/uapi/linux/packet_diag.h
@@ -29,6 +29,7 @@ struct packet_diag_msg {
 };
 
 enum {
+        /* PACKET_DIAG_NONE, standard nl API requires this attribute!  */
         PACKET_DIAG_INFO,
         PACKET_DIAG_MCLIST,
         PACKET_DIAG_RX_RING,
diff --git a/include/uapi/linux/unix_diag.h b/include/uapi/linux/unix_diag.h
index b9e2a6a7446f..1eb0b8dd1830 100644
--- a/include/uapi/linux/unix_diag.h
+++ b/include/uapi/linux/unix_diag.h
@@ -31,6 +31,7 @@ struct unix_diag_msg {
 };
 
 enum {
+        /* UNIX_DIAG_NONE, standard nl API requires this attribute!  */
         UNIX_DIAG_NAME,
         UNIX_DIAG_VFS,
         UNIX_DIAG_PEER,