From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 6677B42489; Fri, 27 Jan 2023 17:30:24 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 0A25740150; Fri, 27 Jan 2023 17:30:24 +0100 (CET) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by mails.dpdk.org (Postfix) with ESMTP id ADAE240146 for ; Fri, 27 Jan 2023 17:30:21 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1674837020; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=wqPTMc3qz0IgjvXoPJm1PbavcC7KgVmFzy/OcSz+5FA=; b=gQN+jr7NnmvYPiEL+NJWTDAE7V1IjoVom+UC8niSWPKLVG6CZcE9guX6HwHZ1zXs16fsq+ NB7kAggOsBjlNfvpi33ffxdUZ60OYZ8AGwGBOIOCyAS5bAVrCs7u1eZbnJWdL8PCCa3M1z YZT1g2BvX1ThhgDT+3N+POQtr3stOUY= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-516-ZohzdEt7PZGNhq5Fv5KTHQ-1; Fri, 27 Jan 2023 11:30:19 -0500 X-MC-Unique: ZohzdEt7PZGNhq5Fv5KTHQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E6796183B3C8; Fri, 27 Jan 2023 16:30:18 +0000 (UTC) Received: from [10.39.208.33] (unknown [10.39.208.33]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A7ACA14171BE; Fri, 27 Jan 2023 16:30:17 +0000 (UTC) Message-ID: Date: Fri, 27 Jan 2023 17:30:15 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 Subject: Re: [PATCH] vhost: improve truncated messages handling To: dev@dpdk.org, david.marchand@redhat.com, chenbo.xia@intel.com References: <20230127135731.22499-1-maxime.coquelin@redhat.com> From: Maxime Coquelin In-Reply-To: <20230127135731.22499-1-maxime.coquelin@redhat.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org On 1/27/23 14:57, Maxime Coquelin wrote: > This patch improves truncated messages logging to ease > debugging. > > First, it differentiates between message's buffer > truncation and control data truncation. Indeed, MSG_CTRUNC > can happen even if enough room was provided, in case LSM > detects access rights issue. > > Then, it does not return directly in case of truncation, > but returns normally to let a chance to display request > type in Vhost-user protocol layer logs. > > Signed-off-by: Maxime Coquelin > --- > lib/vhost/socket.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) Discussing with David, there was/is a possible FDs leak when truncation happens, a V2 is coming to handle these properly. > diff --git a/lib/vhost/socket.c b/lib/vhost/socket.c > index 863a6f6d52..669c322e12 100644 > --- a/lib/vhost/socket.c > +++ b/lib/vhost/socket.c > @@ -129,10 +129,12 @@ read_fd_message(char *ifname, int sockfd, char *buf, int buflen, int *fds, int m > return ret; > } > > - if (msgh.msg_flags & (MSG_TRUNC | MSG_CTRUNC)) { > + if (msgh.msg_flags & MSG_TRUNC) > VHOST_LOG_CONFIG(ifname, ERR, "truncated msg (fd %d)\n", sockfd); > - return -1; > - } > + > + /* MSG_CTRUNC may be caused by LSM misconfiguration */ > + if (msgh.msg_flags & MSG_CTRUNC) > + VHOST_LOG_CONFIG(ifname, ERR, "truncated control data (fd %d)\n", sockfd); > > for (cmsg = CMSG_FIRSTHDR(&msgh); cmsg != NULL; > cmsg = CMSG_NXTHDR(&msgh, cmsg)) {