The initial intension was to increase the limits, but some fixes were
needed, then when looking at the code around, other fixes had to be
added too. So now I ended up with 11 fixes (including one early exit
while at it), followed by 4 patches increasing limits, 3 to validate the
modifications, one small improvement in the selftests, and some
renaming.

The patches with a Fixes tag are for -net, the rest for net-next.

The last patch contains multiple renaming: please tell me what you
think before I start splitting in smaller commits.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
Changes in v4:
- patch 5: reset timer_done when the timer is reset.
- patch 10: new: selftests: correctly catch error in 'check output'.
- patch 16: add example with init_shapers to silence AI reviews
- Patch 18: clearer way to check errors (without buggy '&&')
- Link to v3: https://patch.msgid.link/20260413-mptcp-inc-limits-v3-0-dd36c9360432@kernel.org

Changes in v3:
- patch 1: new: retransmit ADD_ADDR for ID 0 with right ID.
- patch 5: moved below + support calling sk_free().
- patch 13: new: allow flushing more than 8 endpoints.
- patch 12: clarify single batch of 8 subflows as known limit.
- patch 16: fix typo in comment.
- Link to v2: https://patch.msgid.link/20260410-mptcp-inc-limits-v2-0-5402209f05d3@kernel.org

Changes in v2:
- patch 2: new: fix potential data-race.
- re-order patches 1 to 5 and use shorter prefix (ADD_ADDR rtx).
- patch 6: restore accidentally deleted icsk->icsk_rto > max check.
- patch 16: fix already present checkpatch warning.
- Link to v1: https://patch.msgid.link/20260409-mptcp-inc-limits-v1-0-0e45fa30d914@kernel.org

---
Matthieu Baerts (NGI0) (20):
      mptcp: pm: kernel: correctly retransmit ADD_ADDR ID 0
      mptcp: pm: ADD_ADDR rtx: fix potential data-race
      mptcp: pm: ADD_ADDR rtx: allow ID 0
      mptcp: pm: ADD_ADDR rtx: always decrease sk refcount
      mptcp: pm: ADD_ADDR rtx: free sk if last
      mptcp: pm: ADD_ADDR rtx: resched blocked ADD_ADDR quicker
      mptcp: pm: ADD_ADDR rtx: skip inactive subflows
      mptcp: pm: retrans ADD_ADDR: return early if no retrans
      mptcp: pm: prio: skip closed subflows
      selftests: mptcp: check output: catch cmd errors
      selftests: mptcp: pm: restrict 'unknown' check to pm_nl_ctl
      mptcp: pm: in-kernel: explicitly limit batches to array size
      mptcp: pm: in-kernel: increase all limits to 64
      mptcp: pm: kernel: allow flushing more than 8 endpoints
      mptcp: pm: in-kernel: increase endpoints limit
      selftests: mptcp: join: allow changing ifaces nr per test
      selftests: mptcp: join: validate 8x8 subflows
      selftests: mptcp: pm: validate new limits
      selftests: mptcp: pm: use simpler send/recv forms
      mptcp: pm: clearer ADD_ADDR related helpers names

 net/mptcp/options.c                             |   2 +-
 net/mptcp/pm.c                                  | 184 +++++++++++++-----------
 net/mptcp/pm_kernel.c                           | 106 +++++++++-----
 net/mptcp/pm_userspace.c                        |   6 +-
 net/mptcp/protocol.h                            |  19 +--
 net/mptcp/subflow.c                             |   4 +-
 tools/testing/selftests/net/mptcp/mptcp_join.sh |  33 ++++-
 tools/testing/selftests/net/mptcp/mptcp_lib.sh  |   8 +-
 tools/testing/selftests/net/mptcp/pm_netlink.sh |  74 ++++++----
 tools/testing/selftests/net/mptcp/pm_nl_ctl.c   |   8 +-
 10 files changed, 272 insertions(+), 172 deletions(-)
---
base-commit: b5a5b4d1643659280a5566b761679182ef7a8b25
change-id: 20260403-mptcp-inc-limits-ce9811024066

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 (except selftest_mptcp_join): Success! ✅
- KVM Validation: normal (only selftest_mptcp_join): Success! ✅
- KVM Validation: debug (except selftest_mptcp_join): Unstable: 2 failed test(s): packetdrill_dss packetdrill_mp_capable ⚠️ 
- KVM Validation: debug (only selftest_mptcp_join): Success! ✅
- KVM Validation: btf-normal (only bpftest_all): Success! ✅
- KVM Validation: btf-debug (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/24403127637

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/015a75cc8e81
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=1081148


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)