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Date:   Wed, 16 Sep 2020 17:36:49 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Michal Kubecek <mkubecek@suse.cz>
Cc:     David Miller <davem@davemloft.net>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH net] ethtool: add and use message type for tunnel info
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On Thu, 17 Sep 2020 01:04:10 +0200 (CEST) Michal Kubecek wrote:
> 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: c7d759eb7b12 ("ethtool: add tunnel info interface")
> Signed-off-by: Michal Kubecek <mkubecek@suse.cz>

Ouch, sorry & thanks!

Reviewed-by: Jakub Kicinski <kuba@kernel.org>