From patchwork Mon Dec 9 15:27:38 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiayuan Chen X-Patchwork-Id: 13899968 Received: from m16.mail.163.com (m16.mail.163.com [117.135.210.4]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 79D2C1E9B02; Mon, 9 Dec 2024 15:30:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.4 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733758240; cv=none; b=X2copQByppKrsiY1tAeCO9TLfBhW1AjQoo5JwW17X5xkAxQn2jY0dKcJRph6+pZYUj0J7Q3g+9DOeQxx74GRxCaBU7xsR9G0w+bcimlxhODKDRMipchZfNM1HcL9IQGTi+vTCSEK03ywQZ1WKrZD2kVuvBDuhWbYAL4RzLahPnc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733758240; c=relaxed/simple; bh=+pmhuNRkhswua6SLOMooYPuHorwMijotTGOprK61MMU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=MGN3LlvAu3eUJ3MMFeD06DP6ToCYtKcsJraYfx2kk8/ZvSaYn0u83EFSVNMnCTnXGtKx6oOVWFcfd7n6OTXRYfyhG8WKwFKe6MYEfzTld/8XBS4bNJJ+6CxSuTfMU+ERv5C2dTI1fagR3BgVHDOVc1J7IhfLs/I5uTC62dBBgvI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=k2OGCTq/; arc=none smtp.client-ip=117.135.210.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="k2OGCTq/" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-ID:MIME-Version; bh=4oXAF o3Aka3mJCel7XLaaZYfLNktYuW8pXDmkjHW2Rg=; b=k2OGCTq/vVnTuKqqoxLYp V8P9g7HlCw3cNTRUoCOTOjR1lXujMOPot/GspsuEWOS0mxudDBlFUKi5rNp3FzQK nMF8RYb30PCnnThOj7EdhUIWcXglgKGrT0KXzHVYFDtIb5VtylZmG55oRW88vI/8 2LFNUAiBPx1kR1BtQ2eNhA= Received: from localhost.localdomain (unknown [47.252.33.72]) by gzga-smtp-mtada-g1-3 (Coremail) with SMTP id _____wAnl61uDFdn8utwDA--.9599S2; Mon, 09 Dec 2024 23:27:49 +0800 (CST) From: Jiayuan Chen To: bpf@vger.kernel.org Cc: martin.lau@linux.dev, ast@kernel.org, edumazet@google.com, jakub@cloudflare.com, davem@davemloft.net, dsahern@kernel.org, kuba@kernel.org, pabeni@redhat.com, linux-kernel@vger.kernel.org, song@kernel.org, john.fastabend@gmail.com, andrii@kernel.org, mhal@rbox.co, yonghong.song@linux.dev, daniel@iogearbox.net, xiyou.wangcong@gmail.com, horms@kernel.org, Jiayuan Chen Subject: [PATCH bpf v2 0/2] bpf: fix wrong copied_seq calculation and add tests Date: Mon, 9 Dec 2024 23:27:38 +0800 Message-ID: <20241209152740.281125-1-mrpre@163.com> X-Mailer: git-send-email 2.43.5 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: _____wAnl61uDFdn8utwDA--.9599S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxWFyrGFyfXw4kuryDAFyxKrg_yoW5Cw4kpF WkC3yFgrnrtFWIvF1DAayIqr4rGw4rCay5Jr1Fqay3Ars8Kr1fZrn7Ka13Zr95GrWrZF15 Zr1UJrs09w1DZa7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0zi5ku7UUUUU= X-CM-SenderInfo: xpus2vi6rwjhhfrp/xtbBDwawp2dXCYWxWwAAsI X-Patchwork-Delegate: bpf@iogearbox.net A previous commit described in this topic http://lore.kernel.org/bpf/20230523025618.113937-9-john.fastabend@gmail.com directly updated 'sk->copied_seq' in the tcp_eat_skb() function when the action of a BPF program was SK_REDIRECT. For other actions, like SK_PASS, the update logic for 'sk->copied_seq' was moved to tcp_bpf_recvmsg_parser() to ensure the accuracy of the 'fionread' feature. That commit works for a single stream_verdict scenario, as it also modified 'sk_data_ready->sk_psock_verdict_data_ready->tcp_read_skb' to remove updating 'sk->copied_seq'. However, for programs where both stream_parser and stream_verdict are active(strparser purpose), tcp_read_sock() was used instead of tcp_read_skb() (sk_data_ready->strp_data_ready->tcp_read_sock) tcp_read_sock() now still update 'sk->copied_seq', leading to duplicated updates. In summary, for strparser + SK_PASS, copied_seq is redundantly calculated in both tcp_read_sock() and tcp_bpf_recvmsg_parser(). The issue causes incorrect copied_seq calculations, which prevent correct data reads from the recv() interface in user-land. Modifying tcp_read_sock() or strparser implementation directly is unreasonable, as it is widely used in other modules. Here, we introduce a method tcp_bpf_read_sock() to replace 'sk->sk_socket->ops->read_sock' (like 'tls_build_proto()' does in tls_main.c). Such replacement action was also used in updating tcp_bpf_prots in tcp_bpf.c, so it's not weird. (Note that checkpatch.pl may complain missing 'const' qualifier when we define the bpf-specified 'proto_ops', but we have to do because we need update it). Also we remove strparser check in tcp_eat_skb() since we implement custom function tcp_bpf_read_sock() without copied_seq updating. Since strparser currently supports only TCP, it's sufficient for 'ops' to inherit inet_stream_ops. In strparser's implementation, regardless of partial or full reads, it completely clones the entire skb, allowing us to unconditionally free skb in tcp_bpf_read_sock(). We added test cases for bpf + strparser and separated them from sockmap_basic. This is because we need to add more test cases for strparser in the future. Fixes: e5c6de5fa025 ("bpf, sockmap: Incorrectly handling copied_seq") --- v1-v2: fix patchwork fail by adding Fixes tag --- --- Jiayuan Chen (2): bpf: fix wrong copied_seq calculation selftests/bpf: add strparser test for bpf include/linux/skmsg.h | 1 + include/net/tcp.h | 1 + net/core/skmsg.c | 3 + net/ipv4/tcp.c | 2 +- net/ipv4/tcp_bpf.c | 77 +++++- .../selftests/bpf/prog_tests/sockmap_basic.c | 53 ---- .../selftests/bpf/prog_tests/sockmap_strp.c | 255 ++++++++++++++++++ .../selftests/bpf/progs/test_sockmap_strp.c | 51 ++++ 8 files changed, 386 insertions(+), 57 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/sockmap_strp.c create mode 100644 tools/testing/selftests/bpf/progs/test_sockmap_strp.c base-commit: 5a6ea7022ff4d2a65ae328619c586d6a8909b48b