[MPTCP] Re: [PATCH net-next v3] mptcp: fix length of MP_PRIO suboption

[Matthieu Baerts <matthieu.baerts at tessares.net>]

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Hi Davide, Mat,

On 28/01/2021 18:34, Davide Caratti wrote:
> With version 0 of the protocol it was legal to encode the 'Subflow Id' in
> the MP_PRIO suboption, to specify which subflow would change its 'Backup'
> flag. This has been removed from v1 specification: thus, according to RFC
> 8684 §3.3.8, the resulting 'Length' for MP_PRIO changed from 4 to 3 byte.
> 
> Current Linux generates / parses MP_PRIO according to the old spec, using
> 'Length' equal to 4, and hardcoding 1 as 'Subflow Id'; RFC compliance can
> improve if we change 'Length' in other to become 3, leaving a 'Nop' after
> the MP_PRIO suboption. In this way the kernel will emit and accept *only*
> MP_PRIO suboptions that are compliant to version 1 of the MPTCP protocol.

Thank you for this new version!

Just added in our tree, at the bottom, with Mat and my RvB tag.

- 91384be37ad9 mptcp: fix length of MP_PRIO suboption

Tests + export have been almost a success! Simult Flow selftest with a 
debug kernel was unstable but it is not new, see:

   https://github.com/multipath-tcp/mptcp_net-next/issues/137

So feel free to send this patch to netdev when you have the opportunity  ;-)
It doesn't conflict with other pending patches from Geliang that have 
been recently sent by Mat.

Cheers,
Matt
-- 
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