From: Geliang Tang <tanggeliang@kylinos.cn>

This series introduces the msk_is_mptcp() helper function to check
whether a socket is an MPTCP parent socket (IPPROTO_MPTCP on SOCK_STREAM).

This helper is useful for adding MPTCP support in various subsystems,
such as MPTCP sockmap support [1] and landlock MPTCP access rights [2].

Naming rationale:
- Initially considered "sk_is_msk", but as Günther pointed out, "msk"
  is already used as an abbreviation in net/mctp, which could cause
  confusion
- "sk_is_mptcp()" is already taken and used to check whether a socket
  is an MPTCP subflow (tcp_sk(sk)->is_mptcp)
- Following the convention of rsk_is_mptcp(), settled on msk_is_mptcp()
  to clearly distinguish MPTCP parent socket checks from subflow checks

[1] mptcp: add sk_is_msk() helper and use it in sockmap
https://patchwork.kernel.org/project/mptcp/patch/29ec7b3fc7febc1c8946add34f859c8253d9714f.1789294365.git.tanggeliang@kylinos.cn/
[2] landlock: Add MPTCP bind and connect access rights
https://patchwork.kernel.org/project/mptcp/patch/20260830201650.67050-4-gnoack3000@gmail.com/

Geliang Tang (2):
  mptcp: add msk_is_mptcp() helper
  Squash to "bpf: Add mptcp_subflow bpf_iter"

 include/net/mptcp.h | 12 ++++++++++++
 net/mptcp/bpf.c     |  9 +--------
 2 files changed, 13 insertions(+), 8 deletions(-)

-- 
2.55.0

Hi Geliang,

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): Success! ✅
- KVM Validation: debug (only selftest_mptcp_join): Success! ✅
- KVM Validation: btf-normal (only bpftest_all): Success! ✅
- KVM Validation: btf-debug (only bpftest_all): Success! ✅
- Perf: Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/38361897543

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/b39a692c5e0f
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=1184430


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)