From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=pass header.oldest-pass=0 smtp.remote-ip=100.103.45.18 ARC-Seal: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=pass; t=1794148795; b=jXL5jHfIpcQuF6HIMbWwIkwwc0GndEg9UPqlzNJFtJXSVe94x3YLzN4c2Az0MSvR79yy vakcSRoBpyNZJGt+3RZSEFmTr351Er9QMxZRgb0O8kHy+K0Dkk1DfLbxjDOA4BV5EQUxZ RCcNtuTWc+avx8m23jWqppMarSvPnyMsQihGdaWWx6nKRH073BOiltlIjHMF4oJZwQu3f mLDzACVEMOr230EOrRxyIbS5703fSZwrXdcrE80tBMm1v4wnTMfwNEieQXJ2sDcitp50t tu/TDT8riawP0YN/91sm/YvrWpMNklNaDRF4Mf0xPuPC/qk+dfPNbw0Wu+fTtC4EBcA== ARC-Message-Signature: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794148795; h=Received:DKIM-Signature:Received:From:Date:Subject:MIME-Version: Content-Type:Message-Id:References:In-Reply-To:To:Cc:X-Mailer: X-Developer-Signature:X-Developer-Key:X-Endpoint-Received: X-Original-From:Reply-To:Content-Transfer-Encoding; bh=FMoAdPEcYt4xKfDhScvEiOopiYclkGEqczu8+BGmiOU=; b=sbG9XGnTetUr7TkVvioWYBOmfREP6mjsdy1J2GIoLyMkPiB1fr9ni7Iw9tJsfTbdflD8 Zq5NkimyxFpwefqn9ze8mDTzBnjzWxQsYqAqzCBRUpvCCL9aXlN8JeEQUN6jQ83+BL2Tw 8GNb2Si65U/4G9kidvW8zUF2Mg4zRC4vIbpJFygL+QjmSFcQzIi131ngK+TIVQaY2N3Wu 40DF1uKg9BWToob8bRkXRbjVKGa5y5Zkoce7F4LL/3AciU2pHkwtubxhgtqs0o6fXoKrt Vl2Q38O2AC1TK/wTIkiH6eb04MBXrmhKauXaofGqxmRixeeDhFmANobqYm4QijPggFw== ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=eCaQUiyO; arc=pass header.oldest-pass=0 smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E6435606A320; Sun, 8 Nov 2026 14:39:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=eCaQUiyO Authentication-Results: smtp.kernel.org; arc=none smtp.remote-ip=100.80.115.77 ARC-Seal: i=1; d=kernel.org; s=arc20260519; a=rsa-sha256; cv=none; t=1794148794; b=aNkGVyxrBbbikCN668/flzS34u3NqryXGwDi8QKwgtg0hECTcM6R2QLj9ppE9u70J5CK FYWSrV2LvkXndDEwG2wVO65EPTEQsvB7V1+tDc+9xFP0kWEopsJg7kn8WCVAlOBhwIDkC vdCkMAE+Cgl3EGBxDJADEocnZrYxHnS/IGOSFh6L6fM5waiohb0iLq2guZHZfTgkbmo3g WsP4xiLGzBwRQqD3O64ryKgYPDFWK0Koqh8vOPFXeoMgc/W78TE4rQ2vexumY3tRIEFC+ W6m3O6EZ77gCdSiTK/vfZDJFTjbxMiAu3tep1nouVh/cAYfdFTsHEQn8Q+K8bTjZrxQ== ARC-Message-Signature: i=1; d=kernel.org; s=arc20260519; a=rsa-sha256; c=relaxed/relaxed; t=1794148794; h=DKIM-Signature:Received:From:Date:Subject:MIME-Version:Content-Type: Message-Id:References:In-Reply-To:To:Cc:X-Mailer: X-Developer-Signature:X-Developer-Key:X-Endpoint-Received: X-Original-From:Reply-To:Content-Transfer-Encoding; bh=FMoAdPEcYt4xKfDhScvEiOopiYclkGEqczu8+BGmiOU=; b=B5Fs3a6t5Fe6HHSaxLn+EZ8xmFUzMmCDA7GlvwxjwVEF97jeerSD+pp/fZ8dL3G7v68A qrSUeJmZgkx3sdTs/b4qTkxX5LiMJAT7kfdcGNDVDI/tByrpFr3qUMshT0R0Oue6NBFXw 7JPlu8ZiCK3alYEBCYOXRpHiadZPJ+YdR93BotsyHpMTMk4klso909nehkZRzEvVPatdu OXvOpUvmGY+k0UHZgRN8Sl3JEggoMNFmYeOh1rtwdLBR6vVF5R4JvBP+EVCCtGfHxzd3l VMoFLrkTdTHXZyH/86qF9ks9pWDD7fFeKBHHX4+0TX+dGINQx7rUQpGev6eictvdF3A== ARC-Authentication-Results: i=1; smtp.kernel.org; arc=none smtp.remote-ip=100.80.115.77 Received: from lkml.kernel.org (nexus.subspace.kernel.org [100.80.115.77]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.kernel.org (Postfix) with ESMTPS id 07FA61F008A1; Sun, 8 Nov 2026 14:39:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794148794; bh=FMoAdPEcYt4xKfDhScvEiOopiYclkGEqczu8+BGmiOU=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To; b=eCaQUiyOoeulPWd1jbleynPgE7eZ3Ty9fm7XbqN7OirQTBApIZPLSvLt8VH24GS0B UsgIanCOp77lHGcbawFvqAkbvceTHL6j6SCl//NlVyATYSAP6AN1sm8+kI5cRUJZwl 6ykpadFywOa37ZJTEGZ3vUlRfzpGFnvt+YAfwrrw2v0mnrupXtG7EKMXSR8Ds7RKGc SGWor8tNAUs+9xJkpyLwk72sa5CGPA4iHLQBfGNmMJr4/SkC8WdpRS7jKgYj9apShg XDO7+euT9zuyc2279h7QEQ0E8ce7iK7JY14cv2cv7mdKdrBRdc46lXiUz5lnBJVgnT 5TAyKhU+jwQ3w== Received: from nexus.subspace.kernel.org (localhost [IPv6:::1]) by lkml.kernel.org (Postfix) with ESMTP id 8520647FBB; Sun, 8 Nov 2026 14:39:53 +0000 (UTC) From: Yongjian Wang via B4 Relay Date: Sun, 08 Nov 2026 22:39:52 +0800 Subject: [PATCH net-next v2 2/4] selftests/net: packetdrill: test tcp_base_mss on passive connections X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Message-Id: <20261108-mtu-probing-series-v2-2-355d6490c3db@gmail.com> References: <20261108-mtu-probing-series-v2-0-355d6490c3db@gmail.com> In-Reply-To: <20261108-mtu-probing-series-v2-0-355d6490c3db@gmail.com> To: davem@davemloft.net, pabeni@redhat.com, ncardwell@google.com, horms@kernel.org, kuba@kernel.org, kuniyu@google.com, shuah@kernel.org, edumazet@kernel.org Cc: linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, panweiping3@gmail.com, netdev@vger.kernel.org, Yongjian Wang X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1794148792; l=1593; i=echoowall@gmail.com; s=20261026; h=from:subject:message-id; bh=dWQVgF2dw8T0SSpgY/AM6QslZB53fGfIfx1Y00i/T1Y=; b=w+o9ztOdtKWCEUBar9Cf62EYRn4QOlVk7ppE9m/R/+dUUhG/2pcVaLBJtqTQWmkp4PD/v/mpk hEcobO0HMGDDCsnGLco1DDnc/Dd3vlC7SSSKVdMQd5dM8w1sKEQ18qO X-Developer-Key: i=echoowall@gmail.com; a=ed25519; pk=9XP6JhqjjPsHCF6UZZZTeqTRnXIa4+ufggnxXtTJ+no= X-Endpoint-Received: by B4 Relay for echoowall@gmail.com/20261026 with auth_id=1323 X-Original-From: Yongjian Wang Reply-To: echoowall@gmail.com Content-Transfer-Encoding: 7bit From: Yongjian Wang Check that a passive connection starts at tcp_base_mss with net.ipv4.tcp_mtu_probing=2, as an active connection does. Signed-off-by: Yongjian Wang --- .../net/packetdrill/tcp_mtu_probing_passive.pkt | 27 ++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/tools/testing/selftests/net/packetdrill/tcp_mtu_probing_passive.pkt b/tools/testing/selftests/net/packetdrill/tcp_mtu_probing_passive.pkt new file mode 100644 index 000000000..14bae144c --- /dev/null +++ b/tools/testing/selftests/net/packetdrill/tcp_mtu_probing_passive.pkt @@ -0,0 +1,27 @@ +// SPDX-License-Identifier: GPL-2.0 +// Test that a passive connection starts at tcp_base_mss with tcp_mtu_probing=2, +// the same way as an active connection. + +`./defaults.sh +sysctl -q net.ipv4.tcp_mtu_probing=2 +sysctl -q net.ipv4.tcp_base_mss=1024 +sysctl -q net.ipv4.tcp_timestamps=0` + + 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 + +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 + +0 bind(3, ..., ...) = 0 + +0 listen(3, 1) = 0 + + +0 < S 0:0(0) win 65535 + +0 > S. 0:0(0) ack 1 + +.1 < . 1:1(0) ack 1 win 65535 + +0 accept(3, ..., ...) = 4 + +// The initial window is sent with tcp_base_mss, not the peer's MSS. + +0 write(4, ..., 10240) = 10240 + +0 > P. 1:2049(2048) ack 1 + +0 > P. 2049:4097(2048) ack 1 + +0 > P. 4097:6145(2048) ack 1 + +0 > P. 6145:8193(2048) ack 1 + +0 > P. 8193:10241(2048) ack 1 + +.1 < . 1:1(0) ack 10241 win 65535 -- Git-157)