From patchwork Thu Dec 30 08:03:04 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Menglong Dong X-Patchwork-Id: 12701312 X-Patchwork-Delegate: bpf@iogearbox.net 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 71060C433FE for ; Thu, 30 Dec 2021 08:03:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237369AbhL3IDf (ORCPT ); Thu, 30 Dec 2021 03:03:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237324AbhL3IDd (ORCPT ); Thu, 30 Dec 2021 03:03:33 -0500 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 96D90C061574; Thu, 30 Dec 2021 00:03:33 -0800 (PST) Received: by mail-pf1-x442.google.com with SMTP id q3so16453347pfs.7; Thu, 30 Dec 2021 00:03:33 -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:in-reply-to:references :mime-version:content-transfer-encoding; bh=SZI6ien2bl1CEWV7vLSkGMBBhpKf63/++avMZM/X2R4=; b=ZWxIe8cHKRnH+huENnIeuj1Jo9fMNwLYapboeqpvbfq4uysoOjYQWW+tOMrdBra7dT qLEEePl3q7dpGO/grxaPc6MkensyeQt3SVNjK9OFsJqVyit9VnusQDE5vzd5p6Psip5f +AeABpeUpKE+o/2FLqlcml1hMlqxc85Gcn2s/akq/pJSTNjB7luxwwfsOBCPteuHmJ0L axbO3vYyERw4QuHJlrhbM6tlSzPa5O0Ju3z3hd1acfd7wk5B1QQkUXnSD4XPdNW5/Wr/ 9MFiKjP43LqkkqzXJ3VH6qpl3ZsJlQDk1cjQllrj0FVZQZw+qPIdfdbJHMQQHhxE1tWZ dzIQ== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=SZI6ien2bl1CEWV7vLSkGMBBhpKf63/++avMZM/X2R4=; b=p0Mb5StPsoFjvdAG1FwoO1JOlRZTDlOtQU7QGe8PhvhxAF1ER5NB+dkJpWmmU3pvNW UQPZouKYJPOQUbFkr8o5bt4JCec5ijn53C4dgQJA2nuesSHBfwTElm8tqmckvd5eZYOM 7lcP7SrGr5JtGExoJ+of8I9Gd8mjSUxB1wvWku/lwZpN+tKhvHaY0Ai1YOWXvlRXk6E+ N8RFYogS14Eo6CouwFI0KqGH3FdluFzWF1ZPQnicFZw1KVXMHcgahRr32ZFBprEfA7sr 6B7y45dmzdS5cp3gUni5HXN+u87apLb8mx5G1cHSNfv2xHkGN//xp0KAc5yJLSK4foVn eyqQ== X-Gm-Message-State: AOAM532lHcrpuiZkKp8doTEDDraR26jlwcRhAyMsdssGxe63oqNlugu7 5M4UvfzQ6+e6yjM2mrj7Jnk= X-Google-Smtp-Source: ABdhPJyZWxA+fDw/JDltbChlls9y7wASGLbJtOYQfpaBc0DYjDl3qkbn0Rwv0nGrt9z9IydibAB3Zg== X-Received: by 2002:a63:ff4f:: with SMTP id s15mr26307083pgk.215.1640851413120; Thu, 30 Dec 2021 00:03:33 -0800 (PST) Received: from localhost.localdomain ([43.132.141.9]) by smtp.gmail.com with ESMTPSA id 13sm26606987pfm.161.2021.12.30.00.03.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 30 Dec 2021 00:03:32 -0800 (PST) From: menglong8.dong@gmail.com X-Google-Original-From: imagedong@tencent.com To: kuba@kernel.org Cc: davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org, edumazet@google.com, 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, bpf@vger.kernel.org, Menglong Dong Subject: [PATCH v2 net-next 1/2] net: bpf: handle return value of BPF_CGROUP_RUN_PROG_INET{4,6}_POST_BIND() Date: Thu, 30 Dec 2021 16:03:04 +0800 Message-Id: <20211230080305.1068950-2-imagedong@tencent.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20211230080305.1068950-1-imagedong@tencent.com> References: <20211230080305.1068950-1-imagedong@tencent.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@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: 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. Signed-off-by: Menglong Dong --- v2: - introduce 'put_port' field for 'struct proto' --- 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 + 9 files changed, 11 insertions(+) diff --git a/include/net/sock.h b/include/net/sock.h index 44cc25f0bae7..f5fc0432374e 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1209,6 +1209,7 @@ struct proto { void (*unhash)(struct sock *sk); void (*rehash)(struct sock *sk); int (*get_port)(struct sock *sk, unsigned short snum); + void (*put_port)(struct sock *sk); #ifdef CONFIG_BPF_SYSCALL int (*psock_update_sk_prot)(struct sock *sk, struct sk_psock *psock, diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 5d18d32557d2..8784e72d4b8b 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -531,6 +531,8 @@ int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk); if (err) { inet->inet_saddr = inet->inet_rcv_saddr = 0; + if (sk->sk_prot->get_port) + sk->sk_prot->put_port(sk); goto out_release_sock; } } diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index e540b0dcf085..0e56df3a45e2 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -994,6 +994,7 @@ struct proto ping_prot = { .hash = ping_hash, .unhash = ping_unhash, .get_port = ping_get_port, + .put_port = ping_unhash, .obj_size = sizeof(struct inet_sock), }; EXPORT_SYMBOL(ping_prot); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 03dc4c79b84b..0ffb5b5779c0 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -3082,6 +3082,7 @@ struct proto tcp_prot = { .hash = inet_hash, .unhash = inet_unhash, .get_port = inet_csk_get_port, + .put_port = inet_put_port, #ifdef CONFIG_BPF_SYSCALL .psock_update_sk_prot = tcp_bpf_update_proto, #endif diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index f376c777e8fc..c87e3888c8f8 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -2926,6 +2926,7 @@ struct proto udp_prot = { .unhash = udp_lib_unhash, .rehash = udp_v4_rehash, .get_port = udp_v4_get_port, + .put_port = udp_lib_unhash, #ifdef CONFIG_BPF_SYSCALL .psock_update_sk_prot = udp_bpf_update_proto, #endif diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index d1636425654e..ddfc6821e682 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -413,6 +413,8 @@ static int __inet6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, if (err) { sk->sk_ipv6only = saved_ipv6only; inet_reset_saddr(sk); + if (sk->sk_prot->get_port) + sk->sk_prot->put_port(sk); goto out; } } diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c index 6ac88fe24a8e..9256f6ba87ef 100644 --- a/net/ipv6/ping.c +++ b/net/ipv6/ping.c @@ -177,6 +177,7 @@ struct proto pingv6_prot = { .hash = ping_hash, .unhash = ping_unhash, .get_port = ping_get_port, + .put_port = ping_unhash, .obj_size = sizeof(struct raw6_sock), }; EXPORT_SYMBOL_GPL(pingv6_prot); diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 1ac243d18c2b..075ee8a2df3b 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -2181,6 +2181,7 @@ struct proto tcpv6_prot = { .hash = inet6_hash, .unhash = inet_unhash, .get_port = inet_csk_get_port, + .put_port = inet_put_port, #ifdef CONFIG_BPF_SYSCALL .psock_update_sk_prot = tcp_bpf_update_proto, #endif diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 01e53eb4875a..cd402bdf9eed 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1731,6 +1731,7 @@ struct proto udpv6_prot = { .unhash = udp_lib_unhash, .rehash = udp_v6_rehash, .get_port = udp_v6_get_port, + .put_port = udp_lib_unhash, #ifdef CONFIG_BPF_SYSCALL .psock_update_sk_prot = udp_bpf_update_proto, #endif