From nobody Sun Dec 14 02:18:19 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 080A41E32D7 for ; Wed, 30 Apr 2025 05:49:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745992194; cv=none; b=nNRuLEaX1RgvjELWqPTmgXy0g4xaCntdceO1wOusqPWTcpoe3KuqXTwLv0RqVxgMdv2ThIKmZnfBi2TCPwK3v8sE7vwqmY8HhvY9UkHx4eREr8y9VffOweJ8kxFoWqw2jG60n+0eUUcXVp+E3L5YwVr9zenOtTbTATEJsQ3g/U8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745992194; c=relaxed/simple; bh=R89UzM8Nl2S0Dk+t/6mqljP1CoB32z2e10z66oqIp7o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AC/ArvHMvZuLQL2girRdEcu3a9CPQRQkjc3D29KbbbvZXENsslaonyYciv55x8bqfDmkCyG1lHJPlJxUYNZwxxpLb5+zhYyqHRRAYsV7vvQaUjyWeHELWLuUqPLoW6I0KIo0Jp6WqAfateZbxgO3AsTiQiWLOUFM6iZfdkD4GmE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lwOPK8Qh; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lwOPK8Qh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 003F0C4CEEA; Wed, 30 Apr 2025 05:49:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745992193; bh=R89UzM8Nl2S0Dk+t/6mqljP1CoB32z2e10z66oqIp7o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lwOPK8Qh+aYW+cuhN0mw5ml3VFoJJ3TiPzddrrgmU6nzthaQcPx1s1Jt7RmfsU9mP DJ6diVvfUxy+K1/ejo+Ul2FfUXB0xY0uKu6nqfkKk0zvniqa4T6J5rc3HULJhcG62k V+fe5SmzP9X1wQx47X6dZgsTvu0ygaikw8Z6BM5ZcpKvzHgnFlwQ+QHD8CR3kO0f4Z tZzIAN9PimCjifqxztk0Pp6YQZQpCgL54uqFOj+ZP5l3dxV4RYsj9z4zRrfid3Amit cbD0O1heEQhbqtI6+uAKKG4C7YiOBEAwuMm2fKi4FFxD7/AEY7y4BKHD1wCDa5EamS ua4eNmSH1ykoQ== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang , Matthieu Baerts Subject: [PATCH mptcp-next v3 1/2] tcp: add tcp_sock_set_maxseg Date: Wed, 30 Apr 2025 13:49:44 +0800 Message-ID: <65512e0b126b894d029cad693f8d6b44f70ec311.1745991978.git.geliang@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Geliang Tang Add a helper tcp_sock_set_maxseg() to directly set the TCP_MAXSEG sockopt from kernel space. This new helper will be used in the following patch. Acked-by: Matthieu Baerts (NGI0) Signed-off-by: Geliang Tang --- include/linux/tcp.h | 1 + net/ipv4/tcp.c | 23 ++++++++++++++--------- 2 files changed, 15 insertions(+), 9 deletions(-) diff --git a/include/linux/tcp.h b/include/linux/tcp.h index a8af71623ba7..41206c3f289f 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -624,6 +624,7 @@ void tcp_sock_set_nodelay(struct sock *sk); void tcp_sock_set_quickack(struct sock *sk, int val); int tcp_sock_set_syncnt(struct sock *sk, int val); int tcp_sock_set_user_timeout(struct sock *sk, int val); +int tcp_sock_set_maxseg(struct sock *sk, int val); =20 static inline bool dst_tcp_usec_ts(const struct dst_entry *dst) { diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index e1bbb070e734..e1f00faed760 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3726,6 +3726,19 @@ int tcp_set_window_clamp(struct sock *sk, int val) return 0; } =20 +int tcp_sock_set_maxseg(struct sock *sk, int val) +{ + /* Values greater than interface MTU won't take effect. However + * at the point when this call is done we typically don't yet + * know which interface is going to be used + */ + if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) + return -EINVAL; + + tcp_sk(sk)->rx_opt.user_mss =3D val; + return 0; +} + /* * Socket option code for TCP. */ @@ -3858,15 +3871,7 @@ int do_tcp_setsockopt(struct sock *sk, int level, in= t optname, =20 switch (optname) { case TCP_MAXSEG: - /* Values greater than interface MTU won't take effect. However - * at the point when this call is done we typically don't yet - * know which interface is going to be used - */ - if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) { - err =3D -EINVAL; - break; - } - tp->rx_opt.user_mss =3D val; + tcp_sock_set_maxseg(sk, val); break; =20 case TCP_NODELAY: --=20 2.43.0 From nobody Sun Dec 14 02:18:19 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C67BB1E32D3 for ; Wed, 30 Apr 2025 05:49:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745992195; cv=none; b=Htgt8c1L+sykAXuMQHVCRObn+3rEvGf17/cC/2Ip70HiG+ywRejlWf0fuSlvIlDq8W8dA4bSBesK33HeJyb/3UUo5Mo6PRpBze4r2xilGHOub7/O6Fxkd2YUdc/kUSM2d4tFQS/0Lej4DMKRJEM0JOdJK1jr9gHRTF6xNrsdr0w= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745992195; c=relaxed/simple; bh=3VYPnAy6jQfXdvjrxqQcao6d89NaXnZKASEGyczSm3A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=T7os6jSpHGl2PnJ8MXN9TNqiMDRw3W6BeTZSz8czj8OnAFkyPyh0QGJa8vFQqrpB64u6gOlc5zvbon+foSCcCQ3gIOpiqTqasggnhyGNMsNJ6CyR3OK/ped1L9KEoVUm9MsAL8pJDJYdKxGBZoTkIDehdxIinoma7W9NZbBoJGI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gyibBAEr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gyibBAEr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 24BC0C4CEEC; Wed, 30 Apr 2025 05:49:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745992195; bh=3VYPnAy6jQfXdvjrxqQcao6d89NaXnZKASEGyczSm3A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gyibBAErQFcbVIIFgj/OuOXME3jaHPABHhralkm9W+q90exdKI0qFZqMIdiKZlnkH 9Jrk581qcyMMuUWxUeLTr5C9wfdo2989rak+0XRrjkz8XpOJmUaY5FDuDJTrzFhZTf bfUBiAKo8+zws2rm4lc6pNyNNQ5EjjQMDUggES0mI0eNa302G0sfUv742Y1H7FeTab Ohi5Dl25zROQEWJp4Q3rLmvnSmWIK9X0cyaOX/EmRXEEX+naD/OA1v/o25mXVysJY1 OZSoh8YsrplqiOZu+LUvFz9ziugIdgGkkN0CVZsegNF9LTFEHUNUtc+bjH9Pc2+8pJ 9CFeSgvPv+wLw== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang Subject: [PATCH mptcp-next v3 2/2] mptcp: add TCP_MAXSEG sockopt support Date: Wed, 30 Apr 2025 13:49:45 +0800 Message-ID: X-Mailer: git-send-email 2.43.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Geliang Tang The TCP_MAXSEG socket option is currently not supported by MPTCP, mainly because it has never been requested before. But there are still valid use-cases, e.g. with HAProxy. This patch adds its support in MPTCP by propagating the value to all subflows. Similar to mptcp_setsockopt_first_sf_only(), a generic helper mptcp_setsockopt_all_subflows() is added to set sockopt for each subflows of the mptcp socket. Add a new member for struct mptcp_sock to store the TCP_MAXSEG value, and return this value in getsockopt. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/515 Signed-off-by: Geliang Tang Reviewed-by: Matthieu Baerts (NGI0) --- net/mptcp/protocol.h | 1 + net/mptcp/sockopt.c | 25 +++++++++++++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 64aa091cb685..91aaed17fe56 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -327,6 +327,7 @@ struct mptcp_sock { int keepalive_cnt; int keepalive_idle; int keepalive_intvl; + int maxseg; struct work_struct work; struct sk_buff *ooo_last_skb; struct rb_root out_of_order_queue; diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index afa54fba51e2..5a002dd05cc9 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -798,6 +798,22 @@ static int mptcp_setsockopt_first_sf_only(struct mptcp= _sock *msk, int level, int return ret; } =20 +static int mptcp_setsockopt_all_subflows(struct mptcp_sock *msk, int level= , int optname, + sockptr_t optval, unsigned int optlen) +{ + struct mptcp_subflow_context *subflow; + + mptcp_for_each_subflow(msk, subflow) { + struct sock *ssk =3D mptcp_subflow_tcp_sock(subflow); + int ret =3D 0; + + ret =3D tcp_setsockopt(ssk, level, optname, optval, optlen); + if (ret) + return ret; + } + return 0; +} + static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname, sockptr_t optval, unsigned int optlen) { @@ -859,6 +875,11 @@ static int mptcp_setsockopt_sol_tcp(struct mptcp_sock = *msk, int optname, &msk->keepalive_cnt, val); break; + case TCP_MAXSEG: + msk->maxseg =3D val; + ret =3D mptcp_setsockopt_all_subflows(msk, SOL_TCP, optname, + optval, optlen); + break; default: ret =3D -ENOPROTOOPT; } @@ -1406,6 +1427,9 @@ static int mptcp_getsockopt_sol_tcp(struct mptcp_sock= *msk, int optname, return mptcp_put_int_option(msk, optval, optlen, msk->notsent_lowat); case TCP_IS_MPTCP: return mptcp_put_int_option(msk, optval, optlen, 1); + case TCP_MAXSEG: + return mptcp_getsockopt_first_sf_only(msk, SOL_TCP, optname, + optval, optlen); } return -EOPNOTSUPP; } @@ -1552,6 +1576,7 @@ static void sync_socket_options(struct mptcp_sock *ms= k, struct sock *ssk) tcp_sock_set_keepidle_locked(ssk, msk->keepalive_idle); tcp_sock_set_keepintvl(ssk, msk->keepalive_intvl); tcp_sock_set_keepcnt(ssk, msk->keepalive_cnt); + tcp_sock_set_maxseg(ssk, msk->maxseg); =20 inet_assign_bit(TRANSPARENT, ssk, inet_test_bit(TRANSPARENT, sk)); inet_assign_bit(FREEBIND, ssk, inet_test_bit(FREEBIND, sk)); --=20 2.43.0 From nobody Sun Dec 14 02:18:19 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9B7802F5B for ; Wed, 30 Apr 2025 05:49:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745992197; cv=none; b=H0YUHiH5061eJZfhMpYylphq6JGd2fUzW+idMzwiWya8TDRjvIHKoOZ24lH0o61AA+his3mbn8waNuWykp745fcwE4BVts2QNDv7+xc6j/f2AvqTrORHdeGcn2HLzQsbYC3g35eeIggYXWuotKPq+Me98UwNLkfOBTjhoa61+60= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745992197; c=relaxed/simple; bh=igiezey9IHpi5LcP8v/etVFyBzpmKtLj4SdEiY/jDyI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=f9bllIqyJF44xDkbcRuWAfHdBvUGQlVBbZ/8so/dX7p/LniuREFMQAqaoxwlxwYC6wd7pFcmkqVuEZP6RdVtZ9oOwlx9YruHZCJFE2+At4LsFE9PUdNgot+DQnJkRA/oiNeFwHHSKS6CAeEKXHX38mtOQRx2hl8l8KfN15eBHfg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qtz/rEQy; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qtz/rEQy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F2044C4CEE9; Wed, 30 Apr 2025 05:49:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745992197; bh=igiezey9IHpi5LcP8v/etVFyBzpmKtLj4SdEiY/jDyI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qtz/rEQyWEhOEPSjbSk+b4ocIY55PflzRdtjxo+aGtEzbll7JlSDOCexkMBnGqIjA ZWsBT6Iu9AGvTMeMAvloNDM/BRLojhad/E3ven2dOQaqM0YJA9Rp+xtzcPp3j2G3k1 vzkYePqAyOlLm4bvq/F/vLc8iR0z8798ZP9IPk4p0B3I49u676AaxMIQWWQWGvaAlt /C45nY6XYEAWlgEsUUzK5/V6+LPLhR5b+gnFGZLKjjP6WntwB9mjyymB3KSfCHSSpl vGBVCacrHnc2GrnhF9HYhNwiF25No+f9s5nsEPlZrvo34LrkWTmZGJclE8eF0G2hAV NGCOV9JjuJWNQ== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang Subject: [PATCH mptcp-next] mptcp: validate maxseg sockopt Date: Wed, 30 Apr 2025 13:49:46 +0800 Message-ID: X-Mailer: git-send-email 2.43.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" This patch validates the newly added TCP_MAXSEG sockopt. Signed-off-by: Geliang Tang --- gtests/net/mptcp/sockopts/sockopt_maxseg.pkt | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) create mode 100644 gtests/net/mptcp/sockopts/sockopt_maxseg.pkt diff --git a/gtests/net/mptcp/sockopts/sockopt_maxseg.pkt b/gtests/net/mptc= p/sockopts/sockopt_maxseg.pkt new file mode 100644 index 0000000..62492db --- /dev/null +++ b/gtests/net/mptcp/sockopts/sockopt_maxseg.pkt @@ -0,0 +1,20 @@ +--tolerance_usecs=3D100000 +`../common/defaults.sh` + +0.0 socket(..., SOCK_STREAM, IPPROTO_MPTCP) =3D 3 + ++0 bind(3, ..., ...) =3D 0 ++0 listen(3, 1) =3D 0 + ++0 setsockopt(3, SOL_TCP, TCP_MAXSEG, [1000], 4) =3D 0 ++0 getsockopt(3, SOL_TCP, TCP_MAXSEG, [1000], [4]) =3D 0 + ++0 < S 0:0(0) win 8000 ++0 > S. 0:0(0) ack 1 ++0.01 < . 1:1(0) ack 1 win 8000 = ++0 accept(3, ..., ...) =3D 4 + ++0 write(4, ..., 100) =3D 100 + ++0 > P. 1:101(100) ack 1 ++0.01 < . 1:1(0) ack 101 win 256 --=20 2.43.0