ethtool: add and use message type for tunnel info reply

Tunnel offload info code uses ETHTOOL_MSG_TUNNEL_INFO_GET message type (cmd field in genetlink header) for replies to tunnel info netlink request, i.e. the same value as the request have. This is a problem because we are using two separate enums for userspace to kernel and kernel to userspace message types so that this ETHTOOL_MSG_TUNNEL_INFO_GET (28) collides with ETHTOOL_MSG_CABLE_TEST_TDR_NTF which is what message type 28 means for kernel to userspace messages. As the tunnel info request reached mainline in 5.9 merge window, we should still be able to fix the reply message type without breaking backward compatibility. Fixes: c7d759e ("ethtool: add tunnel info interface") Signed-off-by: Michal Kubecek <[email protected]> Reviewed-by: Jakub Kicinski <[email protected]> Signed-off-by: David S. Miller <[email protected]>
zandrey · Sep 17, 2020 · 19a83d3 · 19a83d3
1 parent 9fb030a
commit 19a83d3
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Showing 3 changed files with 6 additions and 2 deletions.
diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
@@ -206,6 +206,7 @@ Userspace to kernel:
   ``ETHTOOL_MSG_TSINFO_GET``		get timestamping info
   ``ETHTOOL_MSG_CABLE_TEST_ACT``        action start cable test
   ``ETHTOOL_MSG_CABLE_TEST_TDR_ACT``    action start raw TDR cable test
+  ``ETHTOOL_MSG_TUNNEL_INFO_GET``       get tunnel offload info
   ===================================== ================================
 
 Kernel to userspace:
@@ -239,6 +240,7 @@ Kernel to userspace:
   ``ETHTOOL_MSG_TSINFO_GET_REPLY``	timestamping info
   ``ETHTOOL_MSG_CABLE_TEST_NTF``        Cable test results
   ``ETHTOOL_MSG_CABLE_TEST_TDR_NTF``    Cable test TDR results
+  ``ETHTOOL_MSG_TUNNEL_INFO_GET_REPLY`` tunnel offload info
   ===================================== =================================
 
 ``GET`` requests are sent by userspace applications to retrieve device
@@ -1363,4 +1365,5 @@ are netlink only.
   ``ETHTOOL_SFECPARAM``               n/a
   n/a                                 ''ETHTOOL_MSG_CABLE_TEST_ACT''
   n/a                                 ''ETHTOOL_MSG_CABLE_TEST_TDR_ACT''
+  n/a                                 ``ETHTOOL_MSG_TUNNEL_INFO_GET``
   =================================== =====================================
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
@@ -79,6 +79,7 @@ enum {
 	ETHTOOL_MSG_TSINFO_GET_REPLY,
 	ETHTOOL_MSG_CABLE_TEST_NTF,
 	ETHTOOL_MSG_CABLE_TEST_TDR_NTF,
+	ETHTOOL_MSG_TUNNEL_INFO_GET_REPLY,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_KERNEL_CNT,

diff --git a/net/ethtool/tunnels.c b/net/ethtool/tunnels.c
@@ -200,7 +200,7 @@ int ethnl_tunnel_info_doit(struct sk_buff *skb, struct genl_info *info)
 	reply_len = ret + ethnl_reply_header_size();
 
 	rskb = ethnl_reply_init(reply_len, req_info.dev,
-				ETHTOOL_MSG_TUNNEL_INFO_GET,
+				ETHTOOL_MSG_TUNNEL_INFO_GET_REPLY,
 				ETHTOOL_A_TUNNEL_INFO_HEADER,
 				info, &reply_payload);
 	if (!rskb) {
@@ -273,7 +273,7 @@ int ethnl_tunnel_info_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 				goto cont;
 
 			ehdr = ethnl_dump_put(skb, cb,
-					      ETHTOOL_MSG_TUNNEL_INFO_GET);
+					      ETHTOOL_MSG_TUNNEL_INFO_GET_REPLY);
 			if (!ehdr) {
 				ret = -EMSGSIZE;
 				goto out;