Recently, a few issues have been discovered around the creation of
additional subflows. Without these counters, it was difficult to point
out the reason why some subflows were not created as expected.

All error paths from __mptcp_subflow_connect() are covered.

These new counters are also verified in the MPTCP Join selftest.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
Matthieu Baerts (NGI0) (2):
      mptcp: MIB counters for sent MP_JOIN
      selftests: mptcp: join: validate MPJ SYN TX MIB counters

 net/mptcp/mib.c                                 |  5 ++
 net/mptcp/mib.h                                 |  5 ++
 net/mptcp/subflow.c                             | 24 ++++++++--
 tools/testing/selftests/net/mptcp/mptcp_join.sh | 63 +++++++++++++++++++++++++
 4 files changed, 93 insertions(+), 4 deletions(-)
---
base-commit: a9a9b3b154d187864b73eb0e86a0ff737d79a10a
change-id: 20240724-mptcp-join-tx-mib-84e21ea4b236

Best regards,
-- 
Matthieu Baerts (NGI0) <matttbe@kernel.org>

Hi Matthieu,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal: Success! ✅
- KVM Validation: debug: Success! ✅
- KVM Validation: btf (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/10115560325

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/6a77ba3f17f2
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=874150


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-normal

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)