From patchwork Sat May 8 22:08:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cong Wang X-Patchwork-Id: 12246269 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 X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5AB7BC43462 for ; Sat, 8 May 2021 22:09:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 397016140F for ; Sat, 8 May 2021 22:09:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229713AbhEHWKW (ORCPT ); Sat, 8 May 2021 18:10:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46248 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229696AbhEHWKT (ORCPT ); Sat, 8 May 2021 18:10:19 -0400 Received: from mail-qt1-x82f.google.com (mail-qt1-x82f.google.com [IPv6:2607:f8b0:4864:20::82f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 42EECC061763; Sat, 8 May 2021 15:09:17 -0700 (PDT) Received: by mail-qt1-x82f.google.com with SMTP id a18so9296700qtj.10; Sat, 08 May 2021 15:09:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=E+M2e+5FqfWuaO4MmVZgDT1VoAboQ/2kqTqv/TNQTvA=; b=T1+NQyZnJAwRjz/vV932Oo4s/cC9eaYa0XUpHqetcT+5v7H3hcptpOQNQmAqZTZ9k+ o1QIyRV/zU2xByZkWkq8gkz0CUNXm3SP9fIK2Ua7Q+nUs5U4ZAB8KQSV/ZSNnFgn+ZHT 3ZXwSQKTatrCRn2TcpuV+tb2dMwBypnjPZcMCFUc50fkI+BKg6M0cIHm0CtxgBluW6w6 rrppLyKEj2fWS8ji7q0pzdJx1YxDxD9cmJnrnujqV6AWlomJRzbKm5VewCzghLsxVYqF MgcJ4lw+768Qc3VGv28nFlAX79VjOSqZDwppY3yn7ED0BQGNlmYNRdZzugNo1GBgSBYt BGqg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=E+M2e+5FqfWuaO4MmVZgDT1VoAboQ/2kqTqv/TNQTvA=; b=N0Z8CviaG5kXWfL7NK1TMAsAdp/WS7HCXxYHAUAFKuKa5W6yjTjY7deQmalyUK4CHz +B5yylft5IieSACqMomI1wgU3jbd2/4jmImbtBewAVSeE1HDz4pymLaiVz0UNzxRb+xL Kwmk0eZhP6PRokR+gSrhR8BJ9Ag9OkSuJIVlyzQqwfnZPoePPO1I5cprNSTRxCyi7FOB rLDB1RDAQxj0U1HWJYIcRWOVbtOAj6tDyxEhqllPUOCiSrzqUE6RrAbhe8z0n1v7ebmM m4tfBDp2ahDDboeZE2kSo3GBjEW5SuaJhbh4PmnFm3wFpcuVHI8+ZLpbuxnfGWEEZmSH aeoQ== X-Gm-Message-State: AOAM5333Q3Slfr7kBQ5NdWvibTIGMXXcp6smlJfrJKtmHJSJQacpLSOC eCleMEksKjS87erFxPrudNcNuuPP8WopnQ== X-Google-Smtp-Source: ABdhPJyVoa2AvzGRkQCi0mnhs1h/ry9GyuuZIR0f5VgEvJvqDLNYMC70F1ZUPhxa/YFKZGpjAEufeg== X-Received: by 2002:ac8:6f37:: with SMTP id i23mr80916qtv.221.1620511756371; Sat, 08 May 2021 15:09:16 -0700 (PDT) Received: from unknown.attlocal.net ([2600:1700:65a0:ab60:65fe:be14:6eed:46f]) by smtp.gmail.com with ESMTPSA id 189sm8080797qkd.51.2021.05.08.15.09.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 08 May 2021 15:09:16 -0700 (PDT) From: Cong Wang To: netdev@vger.kernel.org Cc: bpf@vger.kernel.org, jiang.wang@bytedance.com, duanxiongchun@bytedance.com, wangdongdong.6@bytedance.com, Cong Wang , John Fastabend , Daniel Borkmann , Jakub Sitnicki , Lorenz Bauer Subject: [Patch bpf-next v4 07/12] af_unix: implement unix_dgram_bpf_recvmsg() Date: Sat, 8 May 2021 15:08:30 -0700 Message-Id: <20210508220835.53801-8-xiyou.wangcong@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210508220835.53801-1-xiyou.wangcong@gmail.com> References: <20210508220835.53801-1-xiyou.wangcong@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Cong Wang We have to implement unix_dgram_bpf_recvmsg() to replace the original ->recvmsg() to retrieve skmsg from ingress_msg. AF_UNIX is again special here because the lack of sk_prot->recvmsg(). I simply add a special case inside unix_dgram_recvmsg() to call sk->sk_prot->recvmsg() directly. Cc: John Fastabend Cc: Daniel Borkmann Cc: Jakub Sitnicki Cc: Lorenz Bauer Signed-off-by: Cong Wang --- include/net/af_unix.h | 3 +++ net/unix/af_unix.c | 19 ++++++++++++++--- net/unix/unix_bpf.c | 47 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 66 insertions(+), 3 deletions(-) diff --git a/include/net/af_unix.h b/include/net/af_unix.h index cca645846af1..49b13e9bffd0 100644 --- a/include/net/af_unix.h +++ b/include/net/af_unix.h @@ -82,6 +82,9 @@ static inline struct unix_sock *unix_sk(const struct sock *sk) long unix_inq_len(struct sock *sk); long unix_outq_len(struct sock *sk); +int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size, + int nonblock, int flags); + #ifdef CONFIG_SYSCTL int unix_sysctl_register(struct net *net); void unix_sysctl_unregister(struct net *net); diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 5424e8007858..e718ca6237a7 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -2100,11 +2100,11 @@ static void unix_copy_addr(struct msghdr *msg, struct sock *sk) } } -static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg, - size_t size, int flags) +int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size, + int nonblock, int flags) { struct scm_cookie scm; - struct sock *sk = sock->sk; + struct socket *sock = sk->sk_socket; struct unix_sock *u = unix_sk(sk); struct sk_buff *skb, *last; long timeo; @@ -2207,6 +2207,19 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg, return err; } +static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, + int flags) +{ + struct sock *sk = sock->sk; + +#ifdef CONFIG_BPF_SYSCALL + if (sk->sk_prot != &unix_proto) + return sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT, + flags & ~MSG_DONTWAIT, NULL); +#endif + return __unix_dgram_recvmsg(sk, msg, size, flags & MSG_DONTWAIT, flags); +} + static int unix_read_sock(struct sock *sk, read_descriptor_t *desc, sk_read_actor_t recv_actor) { diff --git a/net/unix/unix_bpf.c b/net/unix/unix_bpf.c index 3ff71fb9aac8..debe82e1035d 100644 --- a/net/unix/unix_bpf.c +++ b/net/unix/unix_bpf.c @@ -6,6 +6,52 @@ #include #include +static int unix_dgram_bpf_recvmsg(struct sock *sk, struct msghdr *msg, + size_t len, int nonblock, int flags, + int *addr_len) +{ + struct sk_psock *psock; + int copied, ret; + + psock = sk_psock_get(sk); + if (unlikely(!psock)) + return __unix_dgram_recvmsg(sk, msg, len, nonblock, flags); + + lock_sock(sk); + if (!skb_queue_empty(&sk->sk_receive_queue) && + sk_psock_queue_empty(psock)) { + ret = __unix_dgram_recvmsg(sk, msg, len, nonblock, flags); + goto out; + } + +msg_bytes_ready: + copied = sk_msg_recvmsg(sk, psock, msg, len, flags); + if (!copied) { + int data, err = 0; + long timeo; + + timeo = sock_rcvtimeo(sk, nonblock); + data = sk_msg_wait_data(sk, psock, flags, timeo, &err); + if (data) { + if (!sk_psock_queue_empty(psock)) + goto msg_bytes_ready; + ret = __unix_dgram_recvmsg(sk, msg, len, nonblock, + flags); + goto out; + } + if (err) { + ret = err; + goto out; + } + copied = -EAGAIN; + } + ret = copied; +out: + release_sock(sk); + sk_psock_put(sk, psock); + return ret; +} + static struct proto *unix_prot_saved __read_mostly; static DEFINE_SPINLOCK(unix_prot_lock); static struct proto unix_bpf_prot; @@ -15,6 +61,7 @@ static void unix_bpf_rebuild_protos(struct proto *prot, const struct proto *base *prot = *base; prot->unhash = sock_map_unhash; prot->close = sock_map_close; + prot->recvmsg = unix_dgram_bpf_recvmsg; } static void unix_bpf_check_needs_rebuild(struct proto *ops)