From mboxrd@z Thu Jan 1 00:00:00 1970 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=-14.3 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,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 23FC4C636C8 for ; Sun, 18 Jul 2021 17:49:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDD6D61179 for ; Sun, 18 Jul 2021 17:49:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229525AbhGRRwh (ORCPT ); Sun, 18 Jul 2021 13:52:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38328 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229503AbhGRRwh (ORCPT ); Sun, 18 Jul 2021 13:52:37 -0400 Received: from mail-wr1-x429.google.com (mail-wr1-x429.google.com [IPv6:2a00:1450:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9762C061762; Sun, 18 Jul 2021 10:49:38 -0700 (PDT) Received: by mail-wr1-x429.google.com with SMTP id m2so18811284wrq.2; Sun, 18 Jul 2021 10:49:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=BEhWtFLnLqQZHRzYwBcEqayGanVCaoPpdKEQEbL7vlw=; b=C7PSXlWSVUZz/H0ZN0JJ3JD6m2kSg4VZ3Y7SZ14tP/++GDWFXsWsO2puhWvg14q/XA iBcU/kHBqDYPEw+6fj7ipgM5PRp8AcQBd44hw2J6+nf86Ja5kh86Jk18t6IaEqJVstWs NTxLDxU63V5l80XoG/Xq0Vc5C1jFYbZeNrd1cZA8fez9+TeoirXkOE0ONPrZnH79O9hs JNs3aPjeFJsAXHgPktxBec2a6qg9Jpd0OMic97aRlix1NtEZ4PSpzDjM3/bZc3HO2lrg glsJvm8QqGNnPXl80Y2TNM+TvmiJXFNA4HYmjy0UM7vufu4AOIF2qQ0/yxvPmNAGXWt3 On/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=BEhWtFLnLqQZHRzYwBcEqayGanVCaoPpdKEQEbL7vlw=; b=WVMCppiX4R13t404SehWf9ynfnrCg2/HdXTOSKhSYpsUILEJgirUvUuQbAauq8QFRc OetHtwdfrTXcK96QSaB4ZU/ynyO9CRo7pU3B/JZVwkWrfBlGxNLwb4m6nbAtdfHfDml5 zQyapJzHK1LlAL4hvIUK0yUv5laNSmdFOATts/DJxwGTMfAmE4zr09I6IS1oMkutHCuo vBDNWu2Oo2Tq8FfQI6XGQ13taQTP0UU0DqWh38bkDSFI7gMHemFQij6nfeR8kS5qC7D1 qWobWsCGDAsUtvB2R73NnrAGmVCElcTEkXOSRRPqOb82k8mcKA8bJfo6qmgdNFMXJNsY Qz+w== X-Gm-Message-State: AOAM533vLgmAITiEjazzBPkeS3m3sJ4HEVMoMjDhU8/l03UrWKsavL22 Y1le5zW/f2d/Xo+crUE9zUs= X-Google-Smtp-Source: ABdhPJxsnPcNqdGui/Gej71ZtmTqm68wZmisMrokPTVdmiZBXESCi2nHTLpPlJ8VciGvx2XH4KcJqg== X-Received: by 2002:adf:fe0d:: with SMTP id n13mr25059202wrr.73.1626630577153; Sun, 18 Jul 2021 10:49:37 -0700 (PDT) Received: from [10.0.0.18] ([37.165.22.19]) by smtp.gmail.com with ESMTPSA id e15sm17059080wrp.29.2021.07.18.10.49.35 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 18 Jul 2021 10:49:36 -0700 (PDT) Subject: Re: [PATCH bpf-next v5 07/11] af_unix: implement unix_dgram_bpf_recvmsg() To: Cong Wang , netdev@vger.kernel.org Cc: bpf@vger.kernel.org, Cong Wang , John Fastabend , Daniel Borkmann , Jakub Sitnicki , Lorenz Bauer References: <20210704190252.11866-1-xiyou.wangcong@gmail.com> <20210704190252.11866-8-xiyou.wangcong@gmail.com> From: Eric Dumazet Message-ID: Date: Sun, 18 Jul 2021 19:49:34 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210704190252.11866-8-xiyou.wangcong@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 7/4/21 9:02 PM, Cong Wang wrote: > 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 | 2 ++ > net/unix/af_unix.c | 19 +++++++++-- > net/unix/unix_bpf.c | 75 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 93 insertions(+), 3 deletions(-) > > diff --git a/include/net/af_unix.h b/include/net/af_unix.h > index cca645846af1..435a2c3d5a6f 100644 > --- a/include/net/af_unix.h > +++ b/include/net/af_unix.h > @@ -82,6 +82,8 @@ 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 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 573253c5b5c2..89927678c0dc 100644 > --- a/net/unix/af_unix.c > +++ b/net/unix/af_unix.c > @@ -2098,11 +2098,11 @@ 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 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; > @@ -2205,6 +2205,19 @@ 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); > +} > + > 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 b1582a659427..db0cda29fb2f 100644 > --- a/net/unix/unix_bpf.c > +++ b/net/unix/unix_bpf.c > @@ -6,6 +6,80 @@ > #include > #include > > +#define unix_sk_has_data(__sk, __psock) \ > + ({ !skb_queue_empty(&__sk->sk_receive_queue) || \ > + !skb_queue_empty(&__psock->ingress_skb) || \ > + !list_empty(&__psock->ingress_msg); \ > + }) > + > +static int unix_msg_wait_data(struct sock *sk, struct sk_psock *psock, > + long timeo) > +{ > + DEFINE_WAIT_FUNC(wait, woken_wake_function); > + struct unix_sock *u = unix_sk(sk); > + int ret = 0; > + > + if (sk->sk_shutdown & RCV_SHUTDOWN) > + return 1; > + > + if (!timeo) > + return ret; > + > + add_wait_queue(sk_sleep(sk), &wait); > + sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); > + if (!unix_sk_has_data(sk, psock)) { > + mutex_unlock(&u->iolock); > + wait_woken(&wait, TASK_INTERRUPTIBLE, timeo); > + mutex_lock(&u->iolock); > + ret = unix_sk_has_data(sk, psock); > + } > + sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); > + remove_wait_queue(sk_sleep(sk), &wait); > + return ret; > +} > + > +static int unix_dgram_bpf_recvmsg(struct sock *sk, struct msghdr *msg, > + size_t len, int nonblock, int flags, > + int *addr_len) > +{ > + struct unix_sock *u = unix_sk(sk); > + struct sk_psock *psock; > + int copied, ret; > + > + psock = sk_psock_get(sk); > + if (unlikely(!psock)) > + return __unix_dgram_recvmsg(sk, msg, len, flags); > + > + mutex_lock(&u->iolock); u->iolock mutex is owned here. > + if (!skb_queue_empty(&sk->sk_receive_queue) && > + sk_psock_queue_empty(psock)) { > + ret = __unix_dgram_recvmsg(sk, msg, len, flags); But __unix_dgram_recvmsg() will also try to grab this mutex ? > + goto out; > + } > + > +msg_bytes_ready: > + copied = sk_msg_recvmsg(sk, psock, msg, len, flags); > + if (!copied) { > + long timeo; > + int data; > + > + timeo = sock_rcvtimeo(sk, nonblock); > + data = unix_msg_wait_data(sk, psock, timeo); > + if (data) { > + if (!sk_psock_queue_empty(psock)) > + goto msg_bytes_ready; > + ret = __unix_dgram_recvmsg(sk, msg, len, flags); > + goto out; > + } > + copied = -EAGAIN; > + } > + ret = copied; > +out: > + mutex_unlock(&u->iolock); > + 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; > @@ -14,6 +88,7 @@ static void unix_bpf_rebuild_protos(struct proto *prot, const struct proto *base > { > *prot = *base; > prot->close = sock_map_close; > + prot->recvmsg = unix_dgram_bpf_recvmsg; > } > > static void unix_bpf_check_needs_rebuild(struct proto *ops) >