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=-18.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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=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 BF7D6C433ED for ; Thu, 13 May 2021 14:41:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 92AD660232 for ; Thu, 13 May 2021 14:41:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234587AbhEMOmk (ORCPT ); Thu, 13 May 2021 10:42:40 -0400 Received: from mx12.kaspersky-labs.com ([91.103.66.155]:16822 "EHLO mx12.kaspersky-labs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234455AbhEMOmh (ORCPT ); Thu, 13 May 2021 10:42:37 -0400 Received: from relay12.kaspersky-labs.com (unknown [127.0.0.10]) by relay12.kaspersky-labs.com (Postfix) with ESMTP id 222767680C; Thu, 13 May 2021 17:41:17 +0300 (MSK) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kaspersky.com; s=mail202102; t=1620916877; bh=8eyOE8BkPdFNsTYf0/6ETb9GDgGGDZJqemFpISKnhFI=; h=Subject:To:From:Message-ID:Date:MIME-Version:Content-Type; b=f46iYk8aTi5S5SDoOETgulm6FQExZsfX3ONfTf7fXsLCTXiXTkLrr5kYIJA2jFsqL tiC46NN+K8pOQt3fumImYdo4P1l6M/ME3HHaKqmL0YHsv+KWOZDgtuU/JkTnq52oJT U4h1iJUuhxwtaN9ujzM6exL9nhLz7aw/boRxQTkoMowrKcnEz//73hwn1WVhf3hwVM Kcpj9mmZSA1ddTz9GVaaTz61JxaRpSw4XBnlcZpepsW5v55PIxKVCuJZZ1vwZwwPHW bf8oLL2fFfX1GAajmzkIl2B4U/blT+o+itY/EpNC8DR5FJsCzIpbeXRqPE4uehf22u UFOXM56VILh6Q== Received: from mail-hq2.kaspersky.com (unknown [91.103.66.206]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (Client CN "mail-hq2.kaspersky.com", Issuer "Kaspersky MailRelays CA G3" (verified OK)) by mailhub12.kaspersky-labs.com (Postfix) with ESMTPS id 25E8B76387; Thu, 13 May 2021 17:41:14 +0300 (MSK) Received: from [10.16.171.77] (10.64.64.121) by hqmailmbx3.avp.ru (10.64.67.243) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Thu, 13 May 2021 17:41:13 +0300 Subject: Re: [RFC PATCH v9 04/19] af_vsock: implement SEQPACKET receive loop To: Stefano Garzarella CC: Stefan Hajnoczi , "Michael S. Tsirkin" , Jason Wang , "David S. Miller" , Jakub Kicinski , Jorgen Hansen , Colin Ian King , Norbert Slusarek , Andra Paraschiv , "kvm@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "stsp2@yandex.ru" , "oxffffaa@gmail.com" References: <20210508163027.3430238-1-arseny.krasnov@kaspersky.com> <20210508163317.3431119-1-arseny.krasnov@kaspersky.com> <20210513113716.admtjzo5nt2y63qi@steredhat> From: Arseny Krasnov Message-ID: <671fcc57-5288-804a-ac9a-c23a79cf3125@kaspersky.com> Date: Thu, 13 May 2021 17:41:07 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210513113716.admtjzo5nt2y63qi@steredhat> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [10.64.64.121] X-ClientProxiedBy: hqmailmbx3.avp.ru (10.64.67.243) To hqmailmbx3.avp.ru (10.64.67.243) X-KSE-ServerInfo: hqmailmbx3.avp.ru, 9 X-KSE-AntiSpam-Interceptor-Info: scan successful X-KSE-AntiSpam-Version: 5.9.20, Database issued on: 05/13/2021 14:30:02 X-KSE-AntiSpam-Status: KAS_STATUS_NOT_DETECTED X-KSE-AntiSpam-Method: none X-KSE-AntiSpam-Rate: 0 X-KSE-AntiSpam-Info: Lua profiles 163644 [May 13 2021] X-KSE-AntiSpam-Info: Version: 5.9.20.0 X-KSE-AntiSpam-Info: Envelope from: arseny.krasnov@kaspersky.com X-KSE-AntiSpam-Info: LuaCore: 445 445 d5f7ae5578b0f01c45f955a2a751ac25953290c9 X-KSE-AntiSpam-Info: {Tracking_from_domain_doesnt_match_to} X-KSE-AntiSpam-Info: d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;127.0.0.199:7.1.2;kaspersky.com:7.1.1 X-KSE-AntiSpam-Info: Rate: 0 X-KSE-AntiSpam-Info: Status: not_detected X-KSE-AntiSpam-Info: Method: none X-KSE-Antiphishing-Info: Clean X-KSE-Antiphishing-ScanningType: Deterministic X-KSE-Antiphishing-Method: None X-KSE-Antiphishing-Bases: 05/13/2021 14:33:00 X-KSE-AttachmentFiltering-Interceptor-Info: no applicable attachment filtering rules found X-KSE-Antivirus-Interceptor-Info: scan successful X-KSE-Antivirus-Info: Clean, bases: 13.05.2021 13:39:00 X-KSE-BulkMessagesFiltering-Scan-Result: InTheLimit X-KSE-AttachmentFiltering-Interceptor-Info: no applicable attachment filtering rules found X-KSE-BulkMessagesFiltering-Scan-Result: InTheLimit X-KLMS-Rule-ID: 52 X-KLMS-Message-Action: clean X-KLMS-AntiSpam-Status: not scanned, disabled by settings X-KLMS-AntiSpam-Interceptor-Info: not scanned X-KLMS-AntiPhishing: Clean, bases: 2021/05/13 13:03:00 X-KLMS-AntiVirus: Kaspersky Security for Linux Mail Server, version 8.0.3.30, bases: 2021/05/13 10:44:00 #16575454 X-KLMS-AntiVirus-Status: Clean, skipped Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 13.05.2021 14:37, Stefano Garzarella wrote: > On Sat, May 08, 2021 at 07:33:14PM +0300, Arseny Krasnov wrote: >> This adds receive loop for SEQPACKET. It looks like receive loop for >> STREAM, but there is a little bit difference: >> 1) It doesn't call notify callbacks. >> 2) It doesn't care about 'SO_SNDLOWAT' and 'SO_RCVLOWAT' values, because >> there is no sense for these values in SEQPACKET case. >> 3) It waits until whole record is received or error is found during >> receiving. >> 4) It processes and sets 'MSG_TRUNC' flag. >> >> So to avoid extra conditions for two types of socket inside one loop, two >> independent functions were created. >> >> Signed-off-by: Arseny Krasnov >> --- >> v8 -> v9: >> 1) 'tmp_record_len' renamed to 'fragment_len'. >> 2) MSG_TRUNC handled in af_vsock.c instead of transport. >> 3) 'flags' still passed to transport for MSG_PEEK support. > Ah, right I see, sorry for the wrong suggestion to remove it. > >> include/net/af_vsock.h | 4 +++ >> net/vmw_vsock/af_vsock.c | 72 +++++++++++++++++++++++++++++++++++++++- >> 2 files changed, 75 insertions(+), 1 deletion(-) >> >> diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h >> index b1c717286993..5175f5a52ce1 100644 >> --- a/include/net/af_vsock.h >> +++ b/include/net/af_vsock.h >> @@ -135,6 +135,10 @@ struct vsock_transport { >> bool (*stream_is_active)(struct vsock_sock *); >> bool (*stream_allow)(u32 cid, u32 port); >> >> + /* SEQ_PACKET. */ >> + ssize_t (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg, >> + int flags, bool *msg_ready); >> + >> /* Notification. */ >> int (*notify_poll_in)(struct vsock_sock *, size_t, bool *); >> int (*notify_poll_out)(struct vsock_sock *, size_t, bool *); >> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c >> index c4f6bfa1e381..78b9af545ca8 100644 >> --- a/net/vmw_vsock/af_vsock.c >> +++ b/net/vmw_vsock/af_vsock.c >> @@ -1974,6 +1974,73 @@ static int __vsock_stream_recvmsg(struct sock *sk, struct msghdr *msg, >> return err; >> } >> >> +static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg, >> + size_t len, int flags) >> +{ >> + const struct vsock_transport *transport; >> + bool msg_ready; >> + struct vsock_sock *vsk; >> + ssize_t record_len; >> + long timeout; >> + int err = 0; >> + DEFINE_WAIT(wait); >> + >> + vsk = vsock_sk(sk); >> + transport = vsk->transport; >> + >> + timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); >> + msg_ready = false; >> + record_len = 0; >> + >> + while (1) { >> + ssize_t fragment_len; >> + >> + if (vsock_wait_data(sk, &wait, timeout, NULL, 0) <= 0) { >> + /* In case of any loop break(timeout, signal >> + * interrupt or shutdown), we report user that >> + * nothing was copied. >> + */ >> + err = 0; >> + break; >> + } >> + >> + fragment_len = transport->seqpacket_dequeue(vsk, msg, flags, &msg_ready); >> + > So, IIUC, seqpacket_dequeue() must return the real length, > and not the bytes copied, right? > > I'm not sure virtio_transport_seqpacket_do_dequeue() is doing that. > I'll post a comment on that patch. Ok, i'll check it > >> + if (fragment_len < 0) { >> + err = -ENOMEM; >> + break; >> + } >> + >> + record_len += fragment_len; >> + >> + if (msg_ready) >> + break; >> + } >> + >> + if (sk->sk_err) >> + err = -sk->sk_err; >> + else if (sk->sk_shutdown & RCV_SHUTDOWN) >> + err = 0; >> + >> + if (msg_ready && err == 0) { >> + /* User sets MSG_TRUNC, so return real length of >> + * packet. >> + */ >> + if (flags & MSG_TRUNC) >> + err = record_len; >> + else >> + err = len - msg->msg_iter.count; > I think is better to use msg_data_left(msg) instead of accessing fields. Ack > >> + >> + /* Always set MSG_TRUNC if real length of packet is >> + * bigger than user's buffer. >> + */ >> + if (record_len > len) >> + msg->msg_flags |= MSG_TRUNC; >> + } >> + >> + return err; >> +} >> + >> static int >> vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, >> int flags) >> @@ -2029,7 +2096,10 @@ vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, >> goto out; >> } >> >> - err = __vsock_stream_recvmsg(sk, msg, len, flags); >> + if (sk->sk_type == SOCK_STREAM) >> + err = __vsock_stream_recvmsg(sk, msg, len, flags); >> + else >> + err = __vsock_seqpacket_recvmsg(sk, msg, len, flags); >> >> out: >> release_sock(sk); >> -- >> 2.25.1 >> >