Re: [PATCH] ipv6: ip6mr: Recalc UDP checksum before forwarding

From: Eric Dumazet
Date: Wed Dec 13 2017 - 12:52:52 EST


On Wed, 2017-12-13 at 22:20 +1100, Brendan McGrath wrote:
> Currently, when forwarding from a Virtual Interface to a Physical
> Interface, ip_summed is set to a value of CHECKSUM_UNNECESSARY and
> the UDP checksum has not been calculated.
>

This seems a bug then ?
CHECKSUM_UNNECESSARY means checksum has been validated.
Not that we want it being computed later in the stack.

If we force a checksum here, what guarantee do we have packet was not
corrupted before we do this ?