From: Ido Schimmel <idosch@nvidia.com>
To: Eric Dumazet <edumazet@google.com>
Cc: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Simon Horman <horms@kernel.org>, David Ahern <dsahern@kernel.org>,
netdev@vger.kernel.org, eric.dumazet@gmail.com
Subject: Re: [PATCH net] ip6_tunnel: do not use dst6_mtu() in ip4ip6_err() and ip6erspan_tunnel_xmit()
Date: Thu, 11 Jun 2026 09:27:39 +0300 [thread overview]
Message-ID: <20260611062739.GC836457@shredder> (raw)
In-Reply-To: <20260609091337.2672441-1-edumazet@google.com>
On Tue, Jun 09, 2026 at 09:13:37AM +0000, Eric Dumazet wrote:
> This is a minor performance / conceptual fix.
>
> 1) ip6erspan_tunnel_xmit()
>
> ERSPAN tunnel can mirror both IPv4 and IPv6 traffic, skb
> (the packet being mirrored) can be an IPv4 packet,
> and thus dst can be an IPv4 destination entry
>
> Use dst_mtu() which contains generic logic for both families.
>
> 2) ip4ip6_err()
>
> skb2 has been prepared as an IPv4 packet, and its destination
> is an IPv4 route.
>
> dst6_mtu() is optimized for IPv6 destinations and uses INDIRECT_CALL_1
> to call ip6_mtu() directly if the ops match.
>
> We should use dst4_mtu() instead.
>
> Fixes: b40f0130a23b ("ipv6: use dst6_mtu() instead of dst_mtu()")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
prev parent reply other threads:[~2026-06-11 6:27 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-09 9:13 [PATCH net] ip6_tunnel: do not use dst6_mtu() in ip4ip6_err() and ip6erspan_tunnel_xmit() Eric Dumazet
2026-06-11 6:27 ` Ido Schimmel [this message]
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