Re: [PATCH v4 0/2] mptcp: per-event MIB counters for MPTCP_RST_EMPTCP

[Matthieu Baerts <matttbe@kernel.org>]

Hi Shardul,

On 11/06/2026 22:32, Shardul Bankar wrote:
> MPTCP_RST_EMPTCP (reset reason 1) is currently used as a catch-all for
> several distinct conditions across subflow setup, authentication, and
> data-path validation.  This series adds per-event MIB counters at each
> of those use sites and validates them from mptcp_join.sh.
> 
> Patch 1 adds seven counters (MD5SigReset, MPJoinSynAckNoMPJoin,
> MPJoinAckNoMPJoin, MPJoinAckNoCtx, MPJoinNoIdFound, DssReset,
> MPJoinNotEstablished) and increments them in mib.c/mib.h, subflow.c and
> protocol.c.
> 
> Patch 2 adds named env-var expectations for each counter: the
> JOIN-related ones in chk_join_nr() and the two reset ones in
> chk_rst_nr(), both on fixed namespaces.  It also adds one test inside
> signal_address_tests that triggers MPJoinSynAckNoMPJoin from the
> existing ns1/ns2 setup.
> 
> v4 (this version):
>   patch 1: add MPJoinNoIdFound for an MP_JOIN that carries a valid token
>            but for which the path manager returns no local id; it
>            reaches the same MPTCP_RST_EMPTCP that MPJoinNoTokenFound
>            only counts the no-token half of (Matt).
>   patch 2: move the MPJoin* checks into chk_join_nr() with fixed
>            namespaces, leaving only MD5SigReset and DssReset in
>            chk_rst_nr() (Matt); rename the env vars (join_* / rst_md5sig
>            / rst_dss); the new test uses mptcp_lib_wait_local_port_listen()
>            and asserts with chk_join_nr().
Thank you for the v4, and sorry for the exceptionally long delay!

The new version looks good to me:

Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>


New patches for t/upstream:
- 4ef5be975394: mptcp: add per-event MIB counters for MPTCP_RST_EMPTCP
resets
- 69359746fd42: selftests: mptcp: check per-event MPTCP_RST_EMPTCP counters
- Results: b67053e5e63b..25452f1bb469 (export)

Tests are now in progress:

- export:
https://github.com/multipath-tcp/mptcp_net-next/commit/d53994ceed37c0dd4cd6c780d5f0a108c7f5bab2/checks

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.