Re: [PATCH net 4/4] mptcp: sockopt: increase seq in mptcp_setsockopt_all_sf

Matthieu Baerts
2026-05-04T18:08:26Z

Hello,

On 01/05/2026 21:35, Matthieu Baerts (NGI0) wrote:
> mptcp_setsockopt_all_sf() was missing a call to sockopt_seq_inc(). This
> is required not to cause missing synchronization for newer subflows
> created later on.
>
> This helper is called each time a socket option is set on subflows, and
> future ones will need to inherit this option after their creation.

Regarding Sashiko's review, I think this can be ignored: the comments
are about existing code / architecture. In short, for the moment, most
places in sockopt.c assumes that if there is an error to set a socket
option with one subflow, the error will be visible when setting this
option on all of them. Maybe (not sure) this could be changed, but then
this can be done later, when modifying all the other places. Here I
think it is better to keep the same logic as what is done with the other
options.

https://sashiko.dev/#/patchset/20260501-net-mptcp-misc-fixes-7-1-rc3-v1-0-b70118df778e%40kernel.org

Cheers,
Matt
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