MPTCP_RST_EMPTCP (reset reason 1) is used as a catch-all for several
distinct error conditions across subflow setup, authentication, and
data-path validation. The existing MPRstTx/MPRstRx counters only
track aggregate reset volume, making it difficult to diagnose which
code path is triggering subflow resets in production.
Add per-event MIB counters covering each MPTCP_RST_EMPTCP use site
that is not already covered by an existing counter, named after the
underlying event or condition rather than the reset action:
MD5SigReset MD5SIG enabled on listener (incompatible)
MPJoinSynAckNoMPJoin SYN/ACK missing MP_JOIN option
MPJoinAckNoMPJoin server-side ACK missing MP_JOIN option
(fallback path, MPJoin required)
MPJoinAckNoCtx server-side ACK with no subflow context
MPJoinNoIdFound MP_JOIN with a valid token but no PM local ID
DssReset data mapping invalid (also fires on
MAPPING_NODSS / EMIDDLEBOX path)
MPJoinNotEstablished JOIN attempted on a not-fully-established msk
MPJoinNoIdFound covers the second half of the no-msk MP_JOIN reset:
the existing MPJoinNoTokenFound (MPTCP_MIB_JOINNOTOKEN) only counts the
missing-token case in subflow_token_join_request(), while a JOIN that
carries a valid token but for which the path manager returns no local
id reaches the same MPTCP_RST_EMPTCP in subflow_check_req() uncounted.
The aggregate MPRstTx/MPRstRx counters are unchanged.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/511
Signed-off-by: Shardul Bankar <shardul.b@mpiricsoftware.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260812-net-next-mptcp-misc-feat-7-3-v1-5-1905a818f6cb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
3420c0fd7e