netdev - [PATCH net-next v2 0/4] mptcp: add TCP

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250719-net-next-mptcp-tcp_maxseg-v2-0-8c910fbc5307@kernel.org>
Date: Sat, 19 Jul 2025 00:06:55 +0200
From: "Matthieu Baerts (NGI0)" <matttbe@...nel.org>
To: mptcp@...ts.linux.dev, Mat Martineau <martineau@...nel.org>, 
 Geliang Tang <geliang@...nel.org>, "David S. Miller" <davem@...emloft.net>, 
 Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, 
 Paolo Abeni <pabeni@...hat.com>, Simon Horman <horms@...nel.org>, 
 Neal Cardwell <ncardwell@...gle.com>, Kuniyuki Iwashima <kuniyu@...gle.com>, 
 David Ahern <dsahern@...nel.org>
Cc: netdev@...r.kernel.org, linux-kernel@...r.kernel.org, 
 "Matthieu Baerts (NGI0)" <matttbe@...nel.org>, 
 moyuanhao <moyuanhao3676@....com>, Geliang Tang <geliang@...nel.org>
Subject: [PATCH net-next v2 0/4] mptcp: add TCP_MAXSEG sockopt support

The TCP_MAXSEG socket option was not supported by MPTCP, mainly because
it has never been requested before. But there are still valid use-cases,
e.g. with HAProxy.

- Patch 1 is a small cleanup patch in the MPTCP sockopt file.

- Patch 2 expose some code from TCP, to avoid duplicating it in MPTCP.

- Patch 3 adds TCP_MAXSEG sockopt support in MPTCP.

- Patch 4 is not related to the others, it fixes a typo in a comment.

Note that the new TCP_MAXSEG sockopt support has been validated by a new
packetdrill script on the MPTCP CI:

  https://github.com/multipath-tcp/packetdrill/pull/161

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@...nel.org>
---
Changes in v2:
- Patch 2: Set the return value of tcp_sock_set_maxseg() to err.
- Patch 3: make mptcp_setsockopt_all_sf() returns only once.
- Link to v1: https://lore.kernel.org/r/20250716-net-next-mptcp-tcp_maxseg-v1-0-548d3a5666f6@kernel.org

---
Geliang Tang (3):
      mptcp: sockopt: drop redundant tcp_getsockopt
      tcp: add tcp_sock_set_maxseg
      mptcp: add TCP_MAXSEG sockopt support

moyuanhao (1):
      mptcp: fix typo in a comment

 include/linux/tcp.h  |  1 +
 net/ipv4/tcp.c       | 23 ++++++++++++++---------
 net/mptcp/protocol.c |  2 +-
 net/mptcp/protocol.h |  1 +
 net/mptcp/sockopt.c  | 33 +++++++++++++++++++++++++++++----
 5 files changed, 46 insertions(+), 14 deletions(-)
---
base-commit: d61f6cb6f6ef3c70d2ccc0d9c85c508cb8017da9
change-id: 20250716-net-next-mptcp-tcp_maxseg-e7702891080d

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