From nobody Mon Feb 9 06:58:08 2026 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 31082881E for ; Thu, 17 Jul 2025 23:15:34 +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=1752794135; cv=none; b=qGLKqvkx1AA53h3IMx59qdTwNDuS1g9KTHsdYryFze5Dm7DJ2G8qLlkVoB6A21Xt9F3rput4yJdK6w2VrcjpWx5McZkTJ6qhsY8VROYi9wvzwogltHBpz/g37p6VLElenOLhrB8NMB1Jba8mWvO/iSARZTwFd/bGudM6YPC5L4w= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752794135; c=relaxed/simple; bh=BoMel4jkyIBF7CvhxYA2kXkr1dN59q9WaLnOQAVtL5c=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=gEpXAyjnndazVqIFrH9uz0/MEW31YqFqgA0kCvmjLFtydT7ZaoiMJ/Pvpu0AUR26FUJ2mg+HhqlvVnILNqPXB/aSKEBYMNqd2jmeZx0SHU/wu5jUmUryOwYRkqFNbNBaV9R28/cV4e5LoqSTv2niQFNUITeg1gCOZwI3WFrHAbw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LXFyzebz; 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="LXFyzebz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D97EC4CEE3; Thu, 17 Jul 2025 23:15:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752794134; bh=BoMel4jkyIBF7CvhxYA2kXkr1dN59q9WaLnOQAVtL5c=; h=From:Date:Subject:To:Cc:From; b=LXFyzebzg/eU4CSYdyjVETl1QuBNRxvhVV4Y/Cu5RCN9LEUY2dxPy6dJ1KhXU+Vf0 fLZ3z2gljDzHYDsQOCl4/ooeB2P606IihjD9sfMs8ZilZK7V6qIkTw5l7n8+LPvjWt /CzcDekjupgen60NcLeTtX7pYHo/lSLB2CArfMsHEUiMKIdKDBCe2g+FymmUHsaai1 AuWN9gAyiB69NPLnOYqG0bNChlGOsL5DBm2w+c0IKpzjQ9caF+3xNa7ons2vJiNg31 N2Qm8nJed9mWYpUmQVbqIMTxHcwhEx0MjJQ58TP3nrP7XNAG3u0V9mAXAlY32ZK0D9 ZmzoC7sLGvGew== From: "Matthieu Baerts (NGI0)" Date: Fri, 18 Jul 2025 01:15:28 +0200 Subject: [PATCH mptcp-next] mptcp: set ADD_ADDR retrans timeout to 1sec Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250718-mptcp-add_addr_timeout_1-v1-1-58749cbe8b87@kernel.org> X-B4-Tracking: v=1; b=H4sIAA+EeWgC/yWMQQqAIBAAvxJ7TkijjL4SIaVr7SETtQiivyd1m MMcZm6IGAgj9MUNAU+KtLssvCxAr5NbkJHJDqISTSV5xzaftGeTMSoTVKIN9yMpzsTcSClabWt tIec+oKXrWw/wVw6vBOPzvCaaY6N2AAAA X-Change-ID: 20250718-mptcp-add_addr_timeout_1-2b57726cf3cf To: mptcp@lists.linux.dev Cc: "Matthieu Baerts (NGI0)" X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=4061; i=matttbe@kernel.org; h=from:subject:message-id; bh=BoMel4jkyIBF7CvhxYA2kXkr1dN59q9WaLnOQAVtL5c=; b=owGbwMvMwCVWo/Th0Gd3rumMp9WSGDIqW0RVyhiTxfTtvUWW3Xi18ZRK6JWPBTU/18Q/S5nRx Th11YYjHaUsDGJcDLJiiizSbZH5M59X8ZZ4+VnAzGFlAhnCwMUpABOZ84WR4enZ28ezu/a6h79e UnHrzhZvTkWuj1fzjvhc5zOZvnzqqo8M/+x/nYmxFL3G122ZvvX6GlVh5v5f0+11ItrE57mxSu3 /ywkA X-Developer-Key: i=matttbe@kernel.org; a=openpgp; fpr=E8CB85F76877057A6E27F77AF6B7824F4269A073 It doesn't really make sense to wait 2 minutes -- the previous default value -- to retransmit the ADD_ADDR if the echo has not been received in between: that's way too long to react. Switching to 1 second by default, which seems like a good default value, and can be increased for particular cases. Later on, we could eventually use a timeout based on the sRTT, with an exponential backoff, which would be more reactive [1]. Note: the documentation has been updated accordingly, and the selftests are keeping the previous timeout when using a broadcast IP not to have retransmissions in this case, which would cause troubles with the different counters depending on how fast the test will run. Link: https://github.com/multipath-tcp/mptcp_net-next/issues/576 [1] Signed-off-by: Matthieu Baerts (NGI0) --- Documentation/networking/mptcp-sysctl.rst | 5 ++--- net/mptcp/ctrl.c | 2 +- tools/testing/selftests/net/mptcp/mptcp_join.sh | 3 +++ 3 files changed, 6 insertions(+), 4 deletions(-) diff --git a/Documentation/networking/mptcp-sysctl.rst b/Documentation/netw= orking/mptcp-sysctl.rst index 5bfab01eff5a9db89e1484787953241c16e147cf..14059d2cac1b3467d6a8c9c4362= f5a0b427b726d 100644 --- a/Documentation/networking/mptcp-sysctl.rst +++ b/Documentation/networking/mptcp-sysctl.rst @@ -12,10 +12,9 @@ add_addr_timeout - INTEGER (seconds) resent to an MPTCP peer that has not acknowledged a previous ADD_ADDR message. =20 - The default value matches TCP_RTO_MAX. This is a per-namespace - sysctl. + This is a per-namespace sysctl. =20 - Default: 120 + Default: 1 =20 allow_join_initial_addr_port - BOOLEAN Allow peers to send join requests to the IP address and port number used diff --git a/net/mptcp/ctrl.c b/net/mptcp/ctrl.c index fed40dae5583a35914da2cb1c52f37830d72705e..92873457c47ea6b04137cece020= 0317a94b13e0d 100644 --- a/net/mptcp/ctrl.c +++ b/net/mptcp/ctrl.c @@ -97,7 +97,7 @@ const char *mptcp_get_scheduler(const struct net *net) static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet) { pernet->mptcp_enabled =3D 1; - pernet->add_addr_timeout =3D TCP_RTO_MAX; + pernet->add_addr_timeout =3D HZ; /* 1 second */ pernet->blackhole_timeout =3D 3600; pernet->syn_retrans_before_tcp_fallback =3D 2; atomic_set(&pernet->active_disable_times, 0); diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testin= g/selftests/net/mptcp/mptcp_join.sh index b8af65373b3ada96472347171924ad3a6cf14777..87a9d022d31160a8ff6185b3a11= 7a73841512f9a 100755 --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh @@ -2429,6 +2429,7 @@ remove_tests() pm_nl_set_limits $ns1 3 3 pm_nl_add_endpoint $ns1 10.0.12.1 flags signal # broadcast IP: no packet for this address will be received on ns1 + ip netns exec ${ns1} sysctl -q net.mptcp.add_addr_timeout=3D120 pm_nl_add_endpoint $ns1 224.0.0.1 flags signal pm_nl_add_endpoint $ns1 10.0.3.1 flags signal pm_nl_set_limits $ns2 2 2 @@ -3846,6 +3847,7 @@ endpoint_tests() pm_nl_set_limits $ns2 3 3 pm_nl_add_endpoint $ns1 10.0.2.1 id 1 flags signal # broadcast IP: no packet for this address will be received on ns1 + ip netns exec ${ns1} sysctl -q net.mptcp.add_addr_timeout=3D120 pm_nl_add_endpoint $ns1 224.0.0.1 id 2 flags signal pm_nl_add_endpoint $ns1 10.0.1.1 id 42 flags signal { test_linkfail=3D4 speed=3D5 \ @@ -3919,6 +3921,7 @@ endpoint_tests() pm_nl_set_limits $ns1 0 2 pm_nl_set_limits $ns2 1 2 # broadcast IP: no packet for this address will be received on ns1 + ip netns exec ${ns1} sysctl -q net.mptcp.add_addr_timeout=3D120 pm_nl_add_endpoint $ns1 224.0.0.1 id 2 flags signal pm_nl_add_endpoint $ns2 10.0.3.2 id 3 flags subflow { test_linkfail=3D4 speed=3D20 \ --- base-commit: d196b09457190bc11ffca2867d5c12beb5a4759e change-id: 20250718-mptcp-add_addr_timeout_1-2b57726cf3cf Best regards, --=20 Matthieu Baerts (NGI0)