On Wed, 8 May 2019 at 15:11, Paul Wouters <paul@xxxxxxxxx> wrote:
On Wed, 8 May 2019, Dave Cridland wrote:
> Sure about that?
>
> From RFC 760:
>
> That is, it should be careful to send well-formed datagrams, but should accept any datagram that it can interpret (e.g., not object to technical errors where
> the meaning is still clear).
>
> The parenthetical example is explicitly stating that a datagram with a technical error should still be accepted.
Many UDP encapsulations of IP packets do not recalculate the outer UDP
checksum. It's a good thing we accept these datagrams with technical
errors.
There's two observations to be made here, if I understand correctly:
a) The lack of properly checking the outer UDP checksum means that implementations could avoid recalculating it.
b) We could not enforce such checking now, because of such implementations.
I appreciate what you're saying, but it's unclear if either is a good thing.
Dave.
