From mboxrd@z Thu Jan 1 00:00:00 1970 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 EA068222587 for ; Tue, 14 Oct 2025 09:57:10 +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=1760435831; cv=none; b=nMSUF7N/celAPioQFLib343EuxL69QP4PUpfnVT75Ef8FKSeazu/Fq3XzTmwtpwNlxUfaYiCXEsr//2DSPT5bfGK/ytMg87H+ozC4NbRrwwl8WJ4WvKk3+vlCbZpfS9NfevPod3r3ErP15n+6AHP/IUIs4L2arSrP6FkMbPcg4Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760435831; c=relaxed/simple; bh=lqWboh9cu0bs8CnNe74baKVWi21FBq+z2FUOXu81ES4=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=FWn66riRAVfJiuK6ORGIojtyjojVnGCbv2kQAp2gfbTMS/CFP3AQpTbSenjOnZJyNBwaOIdDhtAAnBlQ1dq6olJxk4qyYgGP30x4itiAfyi6rBzxKtELrKTzcIfHCewW99rbTowctmXlC+hhfGUB7Yf+q5ZjFpJXIcuBmWSkiIQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Q4kRCgUo; 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="Q4kRCgUo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EA736C4CEE7; Tue, 14 Oct 2025 09:57:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760435830; bh=lqWboh9cu0bs8CnNe74baKVWi21FBq+z2FUOXu81ES4=; h=Date:Subject:To:References:From:In-Reply-To:From; b=Q4kRCgUoXqFVFmQIdhmTNf+AuYiR43cCubmy1wAy1h0FE1shdlPzzUjLu9SfFj4Lt sONxsHRgFSQqpckT7DqE8IK57yzc3vfBMqDBQ88+A/fP4QPqvQbJwU8cJLhtBap/eC /lvTomMuCN/XWm93DtBDGjoi8O2r/XoE8aw/4Adh8KEvcsFsgZeKjEBcmen6SxZRfz 086ecIGPa1071hSPoT8cZoKxr5Pq64VTgqkF8TAI182JCgT7Ro44uENuBeFiPo/tTT 5GjZM8ptNoFX5+lQId6EldbMeH9kP/91geN+vXc00lfd4X5gqc/7+PuFFlvgQx04zY q8IVhqyDHMJNg== Message-ID: <95e3acf3-9a56-47d8-8314-ed6133403283@kernel.org> Date: Tue, 14 Oct 2025 11:57:07 +0200 Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH mptcp-next 2/2] selftests: mptcp: join: validate extra bind cases Content-Language: en-GB, fr-BE To: Geliang Tang , MPTCP Upstream References: <20251009-bind-extra-listen-v1-0-5ad2077d77a9@kernel.org> <20251009-bind-extra-listen-v1-2-5ad2077d77a9@kernel.org> <6efea80680213decf83313995a7afd9e4ce4fafd.camel@kernel.org> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; keydata= xsFNBFXj+ekBEADxVr99p2guPcqHFeI/JcFxls6KibzyZD5TQTyfuYlzEp7C7A9swoK5iCvf YBNdx5Xl74NLSgx6y/1NiMQGuKeu+2BmtnkiGxBNanfXcnl4L4Lzz+iXBvvbtCbynnnqDDqU c7SPFMpMesgpcu1xFt0F6bcxE+0ojRtSCZ5HDElKlHJNYtD1uwY4UYVGWUGCF/+cY1YLmtfb WdNb/SFo+Mp0HItfBC12qtDIXYvbfNUGVnA5jXeWMEyYhSNktLnpDL2gBUCsdbkov5VjiOX7 CRTkX0UgNWRjyFZwThaZADEvAOo12M5uSBk7h07yJ97gqvBtcx45IsJwfUJE4hy8qZqsA62A nTRflBvp647IXAiCcwWsEgE5AXKwA3aL6dcpVR17JXJ6nwHHnslVi8WesiqzUI9sbO/hXeXw TDSB+YhErbNOxvHqCzZEnGAAFf6ges26fRVyuU119AzO40sjdLV0l6LE7GshddyazWZf0iac nEhX9NKxGnuhMu5SXmo2poIQttJuYAvTVUNwQVEx/0yY5xmiuyqvXa+XT7NKJkOZSiAPlNt6 VffjgOP62S7M9wDShUghN3F7CPOrrRsOHWO/l6I/qJdUMW+MHSFYPfYiFXoLUZyPvNVCYSgs 3oQaFhHapq1f345XBtfG3fOYp1K2wTXd4ThFraTLl8PHxCn4ywARAQABzSRNYXR0aGlldSBC YWVydHMgPG1hdHR0YmVAa2VybmVsLm9yZz7CwZEEEwEIADsCGwMFCwkIBwIGFQoJCAsCBBYC AwECHgECF4AWIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZUDpDAIZAQAKCRD2t4JPQmmgcz33 EACjROM3nj9FGclR5AlyPUbAq/txEX7E0EFQCDtdLPrjBcLAoaYJIQUV8IDCcPjZMJy2ADp7 /zSwYba2rE2C9vRgjXZJNt21mySvKnnkPbNQGkNRl3TZAinO1Ddq3fp2c/GmYaW1NWFSfOmw MvB5CJaN0UK5l0/drnaA6Hxsu62V5UnpvxWgexqDuo0wfpEeP1PEqMNzyiVPvJ8bJxgM8qoC cpXLp1Rq/jq7pbUycY8GeYw2j+FVZJHlhL0w0Zm9CFHThHxRAm1tsIPc+oTorx7haXP+nN0J iqBXVAxLK2KxrHtMygim50xk2QpUotWYfZpRRv8dMygEPIB3f1Vi5JMwP4M47NZNdpqVkHrm jvcNuLfDgf/vqUvuXs2eA2/BkIHcOuAAbsvreX1WX1rTHmx5ud3OhsWQQRVL2rt+0p1DpROI 3Ob8F78W5rKr4HYvjX2Inpy3WahAm7FzUY184OyfPO/2zadKCqg8n01mWA9PXxs84bFEV2mP VzC5j6K8U3RNA6cb9bpE5bzXut6T2gxj6j+7TsgMQFhbyH/tZgpDjWvAiPZHb3sV29t8XaOF BwzqiI2AEkiWMySiHwCCMsIH9WUH7r7vpwROko89Tk+InpEbiphPjd7qAkyJ+tNIEWd1+MlX ZPtOaFLVHhLQ3PLFLkrU3+Yi3tXqpvLE3gO3LM7BTQRV4/npARAA5+u/Sx1n9anIqcgHpA7l 5SUCP1e/qF7n5DK8LiM10gYglgY0XHOBi0S7vHppH8hrtpizx+7t5DBdPJgVtR6SilyK0/mp 9nWHDhc9rwU3KmHYgFFsnX58eEmZxz2qsIY8juFor5r7kpcM5dRR9aB+HjlOOJJgyDxcJTwM 1ey4L/79P72wuXRhMibN14SX6TZzf+/XIOrM6TsULVJEIv1+NdczQbs6pBTpEK/G2apME7vf mjTsZU26Ezn+LDMX16lHTmIJi7Hlh7eifCGGM+g/AlDV6aWKFS+sBbwy+YoS0Zc3Yz8zrdbi Kzn3kbKd+99//mysSVsHaekQYyVvO0KD2KPKBs1S/ImrBb6XecqxGy/y/3HWHdngGEY2v2IP Qox7mAPznyKyXEfG+0rrVseZSEssKmY01IsgwwbmN9ZcqUKYNhjv67WMX7tNwiVbSrGLZoqf Xlgw4aAdnIMQyTW8nE6hH/Iwqay4S2str4HZtWwyWLitk7N+e+vxuK5qto4AxtB7VdimvKUs x6kQO5F3YWcC3vCXCgPwyV8133+fIR2L81R1L1q3swaEuh95vWj6iskxeNWSTyFAVKYYVskG V+OTtB71P1XCnb6AJCW9cKpC25+zxQqD2Zy0dK3u2RuKErajKBa/YWzuSaKAOkneFxG3LJIv Hl7iqPF+JDCjB5sAEQEAAcLBXwQYAQIACQUCVeP56QIbDAAKCRD2t4JPQmmgc5VnD/9YgbCr HR1FbMbm7td54UrYvZV/i7m3dIQNXK2e+Cbv5PXf19ce3XluaE+wA8D+vnIW5mbAAiojt3Mb 6p0WJS3QzbObzHNgAp3zy/L4lXwc6WW5vnpWAzqXFHP8D9PTpqvBALbXqL06smP47JqbyQxj Xf7D2rrPeIqbYmVY9da1KzMOVf3gReazYa89zZSdVkMojfWsbq05zwYU+SCWS3NiyF6QghbW voxbFwX1i/0xRwJiX9NNbRj1huVKQuS4W7rbWA87TrVQPXUAdkyd7FRYICNW+0gddysIwPoa KrLfx3Ba6Rpx0JznbrVOtXlihjl4KV8mtOPjYDY9u+8x412xXnlGl6AC4HLu2F3ECkamY4G6 UxejX+E6vW6Xe4n7H+rEX5UFgPRdYkS1TA/X3nMen9bouxNsvIJv7C6adZmMHqu/2azX7S7I vrxxySzOw9GxjoVTuzWMKWpDGP8n71IFeOot8JuPZtJ8omz+DZel+WCNZMVdVNLPOd5frqOv mpz0VhFAlNTjU1Vy0CnuxX3AM51J8dpdNyG0S8rADh6C8AKCDOfUstpq28/6oTaQv7QZdge0 JY6dglzGKnCi/zsmp2+1w559frz4+IC7j/igvJGX4KDDKUs0mlld8J2u2sBXv7CGxdzQoHaz lzVbFe7fduHbABmYz9cefQpO7wDE/Q== Organization: NGI0 Core In-Reply-To: <6efea80680213decf83313995a7afd9e4ce4fafd.camel@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Geliang, Thank you for the review! On 14/10/2025 08:46, Geliang Tang wrote: > It took me some time to understand this test. Is there something I should add in the commit message to make this clearer? > On Thu, 2025-10-09 at 19:33 +0200, Matthieu Baerts (NGI0) wrote: >> By design, an MPTCP connection will not accept extra subflows where >> no >> MPTCP listening sockets can accept such requests. >> >> In other words, it means that if the 'server' listens on a specific >> address / device, it cannot accept MP_JOIN sent to a different >> address / >> device. Except if there is another MPTCP listening socket accepting >> them. >> >> This is what the new tests are validating: >> >>  - Forcing a bind on the main v4/v6 address, and checking that >> MP_JOIN >>    to announced addresses are not accepted. >> >>  - Also forcing a bind on the main v4/v6 address, but before, another >>    listening socket is created to accept additional subflows. Note >> that >>    'mptcpize run nc -l' -- or something else only doing: >> socket(MPTCP), >>    bind(), listen(0) -- would be enough, but here mptcp_connect >> is >>    reused not to depend on another tool just for that. >> >>  - Same as the previous one, but using v6 link-local addresses: this >> is >>    a bit particular because it is required to specify the outgoing >>    network interface when connecting to a link-local address >> announced >>    by the other peer. When using the routing rules, this doesn't work >>    (the outgoing interface is not known) ; but it does work with a >>    'laminar' endpoint having a specified interface. >> >> Note that extra small modifications are needed for these tests to >> work: >> >>  - mptcp_connect's check_getpeername_connect() check should strip the >>    specified interface when comparing addresses. >> >>  - With IPv6 link-local addresses, it is required to wait for them to >>    be ready (no longer in 'tentative' mode) before using them, >> otherwise >>    the bind() will not be allowed. >> >> Link: https://github.com/multipath-tcp/mptcp_net-next/issues/591 >> Signed-off-by: Matthieu Baerts (NGI0) >> --- >>  tools/testing/selftests/net/mptcp/mptcp_connect.c |  10 +- >>  tools/testing/selftests/net/mptcp/mptcp_join.sh   | 153 >> +++++++++++++++++++++- >>  2 files changed, 161 insertions(+), 2 deletions(-) >> >> diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.c >> b/tools/testing/selftests/net/mptcp/mptcp_connect.c >> index b148cadb96d0..c030b08a7195 100644 >> --- a/tools/testing/selftests/net/mptcp/mptcp_connect.c >> +++ b/tools/testing/selftests/net/mptcp/mptcp_connect.c >> @@ -1064,6 +1064,8 @@ static void check_getpeername_connect(int fd) >>   socklen_t salen = sizeof(ss); >>   char a[INET6_ADDRSTRLEN]; >>   char b[INET6_ADDRSTRLEN]; >> + const char *iface; >> + size_t len; >>   >>   if (getpeername(fd, (struct sockaddr *)&ss, &salen) < 0) { >>   perror("getpeername"); >> @@ -1073,7 +1075,13 @@ static void check_getpeername_connect(int fd) >>   xgetnameinfo((struct sockaddr *)&ss, salen, >>        a, sizeof(a), b, sizeof(b)); >>   >> - if (strcmp(cfg_host, a) || strcmp(cfg_port, b)) >> + iface = strchr(cfg_host, '%'); >> + if (iface) >> + len = iface - cfg_host; >> + else >> + len = strlen(cfg_host) + 1; > > Why do we need to add 1 here? I tested it and it works without adding > 1. If I don't add 1, I will not include '\0' in the comparison with "a". In other words, if you have: cfg_host = "abc"; a = "abc123"; len = strlen(cfg_host); /* = 3 */ Then strncmp(cfg_host, a, len) will return 0 because the 3 first chars are "abc". With 4 chars, they are different: "abc\0" vs "abc1". So it is important to take the delimiter into account, just in case one is the prefix of the other one. Cheers, Matt -- Sponsored by the NGI0 Core fund.