From patchwork Thu Jan 6 13:20:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Menglong Dong X-Patchwork-Id: 530411 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31F1EC433F5 for ; Thu, 6 Jan 2022 13:20:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239462AbiAFNUk (ORCPT ); Thu, 6 Jan 2022 08:20:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41652 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231453AbiAFNUk (ORCPT ); Thu, 6 Jan 2022 08:20:40 -0500 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5237CC061245; Thu, 6 Jan 2022 05:20:40 -0800 (PST) Received: by mail-pf1-x443.google.com with SMTP id t19so2502847pfg.9; Thu, 06 Jan 2022 05:20:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=63CBpxumFRhEVIAPbfpLgh370eooZ85aNh2ixBY2LbQ=; b=GCNOUXs/f/02VYiLHnUwu4VBqscL8MQyNmeEh0LB2ngtSLJTUm24Ffb20Fn6E6r0E5 nN3uU0yvtfARlsAz/bQU6GD9X8Cr7FZzFZNzQ4+7mIYP24y6d+isTIvod8HMRnS79t2w xVGB2o/CPKCFxY7sk446rT+wWvWDHeT/fnhO0XlVHxFbAZv3vQiJdP5o3866YfEyejNz ANBj+XPbSJXLurY7TcLuXd7mI8ZgSTvYAx1NC8h2TfJemAH/lLCwW4j2Gk+4ni3yzkxk eKIbzCQJdF76bDIrEpqiTqZyDtNy0hKFDNkAW8VfldgYYAZfsRJ3DDmbMAHYuela0X5Q GwPw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=63CBpxumFRhEVIAPbfpLgh370eooZ85aNh2ixBY2LbQ=; b=rGZmUVS3hv270SYDGa7YKnk4KVULfcVaK75R6GUEBSUQBguHY8B+gbJY4MuNNnLJks YAKscpXCF+1tKdRLrdtVyn8ujxdekg/7gbnPcHSB27O4TTRgD6aQmiasXKj2mgricoGu 5/5F39/zwxZl1SXpLCrfXFrdoSqwDL0VRqs9ewRWtcWWNjIwGUWcZY21g9ZD3YZWRvYw ht/KTAAt8YQ+LvOM9gf+OhV2r4dAQmB2EazGOdC0zQsI4xb72G6lm1mdxXGbJLBTWYZ0 2974397z0cwefSE1/sdfkdGgx9E5m6XN3lF4ddPoVUOhFgqnk7fbO7n15Wsfsupp4azL OmeA== X-Gm-Message-State: AOAM533xmPX3XQehV7FAn3T4JHXMq4d5th/kZfubVQoB+82b7D9+F43V SSqIZdbYQQyjbn9Vp/iLUk8= X-Google-Smtp-Source: ABdhPJwOUo4pcL7A2OXFJjQ8QWyFkutGi8QKRpQHq+/ZxXoKpMcSP2/auCVyD8YFtJ/i+ZBNcuxylw== X-Received: by 2002:a63:3ece:: with SMTP id l197mr36367239pga.371.1641475239906; Thu, 06 Jan 2022 05:20:39 -0800 (PST) Received: from localhost.localdomain ([43.132.141.9]) by smtp.gmail.com with ESMTPSA id c11sm2777998pfv.85.2022.01.06.05.20.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 06 Jan 2022 05:20:39 -0800 (PST) From: menglong8.dong@gmail.com X-Google-Original-From: imagedong@tencent.com To: kuba@kernel.org, edumazet@google.com Cc: davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org, shuah@kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, bpf@vger.kernel.org, Menglong Dong Subject: [PATCH v5 net-next 0/3] net: bpf: handle return value of post_bind{4,6} and add selftests for it Date: Thu, 6 Jan 2022 21:20:19 +0800 Message-Id: <20220106132022.3470772-1-imagedong@tencent.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Menglong Dong The return value of BPF_CGROUP_RUN_PROG_INET{4,6}_POST_BIND() in __inet_bind() is not handled properly. While the return value is non-zero, it will set inet_saddr and inet_rcv_saddr to 0 and exit: exit: err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk); if (err) { inet->inet_saddr = inet->inet_rcv_saddr = 0; goto out_release_sock; } Let's take UDP for example and see what will happen. For UDP socket, it will be added to 'udp_prot.h.udp_table->hash' and 'udp_prot.h.udp_table->hash2' after the sk->sk_prot->get_port() called success. If 'inet->inet_rcv_saddr' is specified here, then 'sk' will be in the 'hslot2' of 'hash2' that it don't belong to (because inet_saddr is changed to 0), and UDP packet received will not be passed to this sock. If 'inet->inet_rcv_saddr' is not specified here, the sock will work fine, as it can receive packet properly, which is wired, as the 'bind()' is already failed. To undo the get_port() operation, introduce the 'put_port' field for 'struct proto'. For TCP proto, it is inet_put_port(); For UDP proto, it is udp_lib_unhash(); For icmp proto, it is ping_unhash(). Therefore, after sys_bind() fail caused by BPF_CGROUP_RUN_PROG_INET4_POST_BIND(), it will be unbinded, which means that it can try to be binded to another port. The second patch use C99 initializers in test_sock.c The third patch is the selftests for this modification. Changes since v4: - use C99 initializers in test_sock.c before adding the test case Changes since v3: - add the third patch which use C99 initializers in test_sock.c Changes since v2: - NULL check for sk->sk_prot->put_port Changes since v1: - introduce 'put_port' field for 'struct proto' - add selftests for it Menglong Dong (3): net: bpf: handle return value of BPF_CGROUP_RUN_PROG_INET{4,6}_POST_BIND() bpf: selftests: use C99 initializers in test_sock.c bpf: selftests: add bind retry for post_bind{4, 6} include/net/sock.h | 1 + net/ipv4/af_inet.c | 2 + net/ipv4/ping.c | 1 + net/ipv4/tcp_ipv4.c | 1 + net/ipv4/udp.c | 1 + net/ipv6/af_inet6.c | 2 + net/ipv6/ping.c | 1 + net/ipv6/tcp_ipv6.c | 1 + net/ipv6/udp.c | 1 + tools/testing/selftests/bpf/test_sock.c | 370 ++++++++++++++---------- 10 files changed, 233 insertions(+), 148 deletions(-)