selftests: mptcp: check per-event MPTCP_RST_EMPTCP counters

Add named env-var expectations for each per-event MPTCP_RST_EMPTCP
counter, matching the pattern used by the existing JOIN/RST checks.
Each defaults to 0 and is checked silently on success; a mismatch prints
a check line and fails the test.  Counters absent from the running
kernel are skipped silently so older kernels do not false-fail.

The JOIN-related counters (MPJoinSynAckNoMPJoin, MPJoinAckNoMPJoin,
MPJoinAckNoCtx, MPJoinNotEstablished, MPJoinNoIdFound) are checked in
chk_join_nr() on fixed namespaces; the two remaining reset counters
(MD5SigReset, DssReset) stay in chk_rst_nr().

Add a test at the end of signal_address_tests that triggers
MPJoinSynAckNoMPJoin: ns1 signals an address that is already bound on
the client (ns2), where a TCP-only mptcp_connect listener is started.
The client's MP_JOIN routes locally to the TCP listener, which responds
with a plain SYN/ACK without the MP_JOIN option, and the new counter
increments on the client side.

Other per-event counters (MD5SigReset, MPJoinAckNoMPJoin, MPJoinAckNoCtx,
DssReset, MPJoinNotEstablished, MPJoinNoIdFound) are not currently
reachable from mptcp_join.sh; the env-var hooks are in place for future
tests to set expectations explicitly.

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-v1-6-1905a818f6cb@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions