From patchwork Thu Jan 6 01:57:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Menglong Dong X-Patchwork-Id: 12704996 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 405E3C433F5 for ; Thu, 6 Jan 2022 01:57:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344473AbiAFB5g (ORCPT ); Wed, 5 Jan 2022 20:57:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58378 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344461AbiAFB5g (ORCPT ); Wed, 5 Jan 2022 20:57:36 -0500 Received: from mail-pg1-x543.google.com (mail-pg1-x543.google.com [IPv6:2607:f8b0:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2A8BBC061245; Wed, 5 Jan 2022 17:57:36 -0800 (PST) Received: by mail-pg1-x543.google.com with SMTP id g2so1241450pgo.9; Wed, 05 Jan 2022 17:57:36 -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=/Z9qkHqYLIA/7ijai38ZX5F2EkiB7fJkOdc4W8a8iM0=; b=bLlOFMicadL6IIK8tdMi9ohEQIcVhCzhFBCQzsk3g0Zu7MrBRPEyE1UkzQLCWZF+03 agN5BAouCf1EOG9uv1ysvKSL1dfO8eE+XGVe/pHxp/LWLANXoqkJsA2o6VKhhi98b8UQ Z6CKTzb1IisfCLpGDuYi++SDkKMQwRia1RiKdkuHFfcIH/dNQt750D2UvwjHOLG3wooS qUXxzt/d9XJXMbt0HLdAqV1DfW1KbkTPCMKRxQXECHmOHWyIYito1GmEBTRmnIcCyCCN V1dcBKz/1zvY53H41G5B3yaovkdLgYlFk6TNF3oCgpv9slkD+vWcIHTKmXj8n25ppH1b 1SPg== 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=/Z9qkHqYLIA/7ijai38ZX5F2EkiB7fJkOdc4W8a8iM0=; b=KOpSP3PdKQaP3sngT0o2lg0adOWhsooqfdA0Ug34bI23Z4Y9tVKnUwv2kDQ0cBiEL6 yqnY/NoZp5GfMNpVY/f3omKLD+Jwd0O+Jw8Ctr/M5U3G1SQcG5ek1nRI2y+wOvAqbuFS NK9exMLgeozsoRHvoeFudbjgdH7BRjRtOuXrxHrXzvRU7SJ+6glN3RjVl+74PTLdVoXA SSr5uLcW6+syEyl7OJGFAY57vvRHtlrIdqLTM5LtIFI6X6FXT+bc+w6Oe7iGC4ivRU5k Rm4bM+BIDzHQ72TGKrDckKGmDSG8LYyiSX9FWnhluYCUE5lzgOh0j1hljA3ITqJn8KoM s6fw== X-Gm-Message-State: AOAM531QHlQoJPDfJJuB4dgUZ1YSDC2PAQUKpV1Ai/kyQr4o+Kdzc3PB KLiDDLje2CERRHHAst1T6bg= X-Google-Smtp-Source: ABdhPJyKVbqv3npeYD/Egv3KQ9GF0CljKqtvssIQuF5fiKblg85xkAcSb9tcJqQYZ+jcRt8+8YNOYg== X-Received: by 2002:a05:6a00:3001:b0:4bb:ea7d:6c48 with SMTP id ay1-20020a056a00300100b004bbea7d6c48mr45188110pfb.51.1641434255727; Wed, 05 Jan 2022 17:57:35 -0800 (PST) Received: from localhost.localdomain ([43.132.141.9]) by smtp.gmail.com with ESMTPSA id g21sm330910pfc.75.2022.01.05.17.57.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Jan 2022 17:57:35 -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 v4 net-next 0/3] net: bpf: handle return value of post_bind{4,6} and add selftests for it Date: Thu, 6 Jan 2022 09:57:18 +0800 Message-Id: <20220106015721.3038819-1-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 is the selftests for this modification. The third patch use C99 initializers in test_sock.c. 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: add bind retry for post_bind{4, 6} bpf: selftests: use C99 initializers in test_sock.c 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(-)