From owner-freebsd-net@FreeBSD.ORG Sun Aug 11 07:30:06 2013 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id BB1B2DB1 for ; Sun, 11 Aug 2013 07:30:06 +0000 (UTC) (envelope-from darrenr@netbsd.org) Received: from out2-smtp.messagingengine.com (out2-smtp.messagingengine.com [66.111.4.26]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 8C36C2753 for ; Sun, 11 Aug 2013 07:30:06 +0000 (UTC) Received: from compute1.internal (compute1.nyi.mail.srv.osa [10.202.2.41]) by gateway1.nyi.mail.srv.osa (Postfix) with ESMTP id EF0CF21042; Sun, 11 Aug 2013 03:30:04 -0400 (EDT) Received: from frontend1 ([10.202.2.160]) by compute1.internal (MEProxy); Sun, 11 Aug 2013 03:30:04 -0400 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=message-id:date:from:reply-to :mime-version:to:cc:subject:references:in-reply-to:content-type :content-transfer-encoding; s=smtpout; bh=D6KE2y6BRMNQxAUzwu58/N E6YdM=; b=Qfe6BQp1KhpdIenmT298tBJNAuVzgRhxxnf0TTQhs+Ph0y49S3Vncw knq3v2bZz523jhsQUpV8MC9ZqE/kJ24lzkqpUllwvWPI0DceLrJQqMObi3d1PmRM 3DOSPqHl9fK6VSRFqtyT4wgBMJl9Q9MaXbtUjPUIl6Uu0D8iuVcLY= X-Sasl-enc: LFRxrr2wrd8TwRIpLMVSYYFBl5DPCcbaFKeHmZfUqdlR 1376206204 Received: from [172.20.10.2] (unknown [101.172.151.26]) by mail.messagingengine.com (Postfix) with ESMTPA id 64810C00E7F; Sun, 11 Aug 2013 03:30:03 -0400 (EDT) Message-ID: <52073E3D.8060008@netbsd.org> Date: Sun, 11 Aug 2013 17:33:17 +1000 From: Darren Reed Organization: NetBSD User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: Matt Thomas Subject: Re: BPF_MISC+BPF_COP and BPF_COPX References: <20130804191310.2FFBB14A152@mail.netbsd.org> <5202693C.50608@netbsd.org> <20130807175548.1528014A21F@mail.netbsd.org> <5203535D.2040508@netbsd.org> <38CDC9BB-09C7-4241-8746-163BD15B80EC@cs.columbia.edu> <20130809203446.428A714A308@mail.netbsd.org> <20130809204436.GA3261@panix.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: tech-net@NetBSD.org, guy@alum.mit.edu, freebsd-net@freebsd.org X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list Reply-To: darrenr@netbsd.org List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 11 Aug 2013 07:30:06 -0000 On 10/08/2013 7:23 AM, Matt Thomas wrote: > ... > The possibility of the COP/COPX functions doing bad things is over wrought. It makes the assumption of avoiding BPF and then coding everything is safer than using BPF and COP/COPX functions. Depends on what you mean by "bad things." Thus far I haven't seen a proper problem statement, only this: > The problem is simple: I want a generic mechanism to offload more complex > packet inspection operations, e.g. lookup IP address in some container or > walk IPv6 headers and return some offsets. IMHO, the IPv6 problem is and will be common enough to deserve its own instructionas happened with IPv4 and determining the offset of the first byte after the IPv4 header. But the generic offload problem hasn't been explained nearly enough. Is it required for NPF? Is it required for tcpdump? Is it required for dhcpd? ... I don't think we know nearly enough about what the problem is in order to be able to judge whether or not the solution is acceptable. Darren