Subject: Re: [PATCH] ipv6: sit: update mtu check to take care of gso packets

From: Michal Schmidt <[email-masked]>
Date: Tue, 17 Dec 2013 15:22:37 +0100

On 12/16/2013 03:31 PM, Eric Dumazet wrote:
> From: Eric Dumazet <[email-masked]>
> 
> While testing my changes for TSO support in SIT devices,
> I was using sit0 tunnel which appears to include nopmtudisc flag.
> 
> But using :
> 
> ip tun add sittun mode sit remote $REMOTE_IPV4 local $LOCAL_IPV4 \
>    dev $IFACE
> 
> We get a tunnel which rejects too long packets because of the mtu check
> which is not yet GSO aware.
> 
> erd:~# ip tunnel
> sittun: ipv6/ip  remote 10.246.17.84  local 10.246.17.83  ttl inherit  6rd-prefix 2002::/16 
> sit0: ipv6/ip  remote any  local any  ttl 64  nopmtudisc 6rd-prefix 2002::/16 
> 
> This patch is based on an excellent report from
> Michal Shmidt.
> 
> In the future, we probably want to extend the MTU check to do the
> right thing for GSO packets...
> 
> Fixes: ("61c1db7fae21 ipv6: sit: add GSO/TSO support")
> Reported-by: Michal Schmidt <[email-masked]>
> Signed-off-by: Eric Dumazet <[email-masked]>

Tested-by: Michal Schmidt <[email-masked]>

It works fine now. Thanks.
Michal