From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id D0A76A3160 for ; Wed, 9 Oct 2019 17:02:30 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 8E5AA1DFE1; Wed, 9 Oct 2019 17:02:30 +0200 (CEST) Received: from mail-pg1-f193.google.com (mail-pg1-f193.google.com [209.85.215.193]) by dpdk.org (Postfix) with ESMTP id 78C221C230 for ; Wed, 9 Oct 2019 17:02:28 +0200 (CEST) Received: by mail-pg1-f193.google.com with SMTP id d26so1584588pgl.7 for ; Wed, 09 Oct 2019 08:02:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=ovMeI1IE2xoPYH5J8jzYgrAwaYi6UNln5HMbSkz01bI=; b=dDCg5zryUPdAX12oKciXrNGt1aj5xfWvNuCxjz9ZBaUVL75LwdtTdkC2vCdIMbz2ru ueVAQsU+FgxjemRnIH027CiuzFJFExxYxXIdn2TRKW7Cx0ZgIw7X0MlyKfPXsaEUlFIY fcqk+ygkdA+6zgUMv/70u+mE01E8qht07xyjtc8FuOIYZ5sMmb+z/JmfaoWQFit3DVSD 6xpXI56YtLj8pKzQKqWrz4D3qIcA/tMZrSm7cd1YONE0urnfO3oYsFQyFg2jPnG3Grai CR4TjT7H2uxKWqzzJ/9I18kAoKquDfrd5MiCjU2W9/PDHsV4ywF2q4lmQFS6MoXg5qoD Vm6w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=ovMeI1IE2xoPYH5J8jzYgrAwaYi6UNln5HMbSkz01bI=; b=E77Aq/qQIa99uUX72PNtJjROGu9QjoZlSGX17nWbOEJIVIvZ3p12D4wwiJayK7/T9D cF3A/4xjvPrAK/BBaapGhoGe2qTvlXftX8lzWAieEmOZz6pjTk/w5O6b/j26Bj40i/C0 zOnt5k9ebHD+M2Fvt2nIRbZEuVeL9xea1M01F/wC3pE7yz1do6FQJdbp0zDuq7iwzXBg T5IxZsxxcz8vRGjE1NCuZh3USu4b/AvD0Tyl47pmpJyg4mjM+7HlWcWsRb3csr19M9WB ms+ofECNc0n+hFWsSmA991owYUwFjIJ6xNMwpItcsWtSAVAm69yTHhbFiL3c1IAAd4XR vsPg== X-Gm-Message-State: APjAAAX2fMP3zvfcxF5rYaiirIK6XxVubzu84BAU9qWMQI8JF+np5lSS 2C8fBkpK71aWdhtcsiAIpx4IGQ== X-Google-Smtp-Source: APXvYqxxZtzK0NYoFr8CX22XSXsOVCiN8YWAb+L0bsHqwIVQ8in19OeyRTztQWWCHt1XAAS5OaZKqw== X-Received: by 2002:a17:90a:2422:: with SMTP id h31mr4797447pje.100.1570633346969; Wed, 09 Oct 2019 08:02:26 -0700 (PDT) Received: from hermes.lan (204-195-22-127.wavecable.com. [204.195.22.127]) by smtp.gmail.com with ESMTPSA id 199sm2546400pfv.152.2019.10.09.08.02.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Oct 2019 08:02:26 -0700 (PDT) Date: Wed, 9 Oct 2019 08:02:18 -0700 From: Stephen Hemminger To: "Ananyev, Konstantin" Cc: Morten =?UTF-8?B?QnLDuHJ1cA==?= , dpdk-dev , Jerin Jacob Message-ID: <20191009080218.3711bef3@hermes.lan> In-Reply-To: <2601191342CEEE43887BDE71AB977258019197431F@irsmsx105.ger.corp.intel.com> References: <98CBD80474FA8B44BF855DF32C47DC35C60B67@smartserver.smartshare.dk> <2601191342CEEE43887BDE71AB977258019197431F@irsmsx105.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [dpdk-dev] packet data access bug in bpf and pdump libs X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Wed, 9 Oct 2019 11:11:46 +0000 "Ananyev, Konstantin" wrote: > Hi Morten, >=20 > >=20 > > Hi Konstantin and Stephen, > >=20 > > I just noticed the same bug in your bpf and pcap libraries: > >=20 > > You are using rte_pktmbuf_mtod(), but should be using rte_pktmbuf_read(= ). Otherwise you cannot read data across multiple segments. =20 >=20 > In plain data buffer mode expected input for BPF program is start of firs= t segment packet data. > Other segments are simply not available to BPF program in that mode. > AFAIK, cBPF uses the same model. >=20 > >=20 > >=20 > > Med venlig hilsen / kind regards > > - Morten Br=C3=B8rup =20 >=20 For packet capture, the BPF program is only allowed to look at first segmen= t. pktmbuf_read is expensive and can cause a copy.