[PATCH mptcp-next v6 0/7] mptcp: TCP_MD5SIG support

[Geliang Tang <geliang@kernel.org>]

From: Geliang Tang <tanggeliang@kylinos.cn>

v6:
 - update selftests.
 - move "tcp: md5: remove redundant l3flag variable" into this set.

v5:
 - new selftests for MD5.
Link: https://patchwork.kernel.org/project/mptcp/cover/cover.1754837808.git.tanggeliang@kylinos.cn/

v4:
 - drop CONFIG_TCP_MD5SIG check.
 - drop sk_state check.
 - use WARN_ON_ONCE for __mptcp_try_fallback().

v3:
 - limit the use of these options for listened and closed state.
 - check the return value of __mptcp_try_fallback().

v2:
 - trigger fallback to TCP.
 - check CONFIG_TCP_MD5SIG.
 - update MD5 comment.
 - drop selftests, packetdrill tests will be added later.

This series introduces support for TCP_MD5SIG socket options in MPTCP along
with code improvements:

Patch 1: Refactors TCP_MAXSEG getsockopt handling to improve code
consistency
Patch 2: Adds setsockopt support for TCP_MD5SIG/TCP_MD5SIG_EXT (first
subflow only)

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/575

Geliang Tang (7):
  tcp: md5: remove redundant l3flag variable
  mptcp: handle TCP_MAXSEG getsockopt in common case
  mptcp: setsockopt support for TCP_MD5SIG
  selftests: mptcp: sockopt: add md5 argument
  selftests: mptcp: sockopt: implement TCP_MD5SIG support
  selftests: mptcp: sockopt: skip getsockopt for MD5 tests
  selftests: mptcp: sockopt: add TCP_MD5SIG test cases

 net/ipv4/tcp_ipv4.c                           |  7 +-
 net/ipv6/tcp_ipv6.c                           |  9 +-
 net/mptcp/sockopt.c                           | 18 ++--
 net/mptcp/subflow.c                           |  3 +
 tools/testing/selftests/net/mptcp/config      |  3 +
 .../selftests/net/mptcp/mptcp_sockopt.c       | 86 ++++++++++++++++---
 .../selftests/net/mptcp/mptcp_sockopt.sh      | 51 +++++++++++
 7 files changed, 147 insertions(+), 30 deletions(-)

-- 
2.43.0