From owner-freebsd-questions Mon Sep 1 23:56:47 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id XAA20849 for questions-outgoing; Mon, 1 Sep 1997 23:56:47 -0700 (PDT) Received: from gdi.uoregon.edu (cisco-ts15-line15.uoregon.edu [128.223.150.198]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id XAA20844 for ; Mon, 1 Sep 1997 23:56:43 -0700 (PDT) Received: from localhost (dwhite@localhost) by gdi.uoregon.edu (8.8.5/8.8.5) with SMTP id XAA03344; Mon, 1 Sep 1997 23:56:36 -0700 (PDT) Date: Mon, 1 Sep 1997 23:56:35 -0700 (PDT) From: Doug White X-Sender: dwhite@localhost Reply-To: Doug White To: Sunthiti Patchararungruang cc: freebsd-questions@FreeBSD.ORG Subject: Re: Where can I find the information about BPF In-Reply-To: 1845.97 831@plutoware.org Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-questions@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk On Sun, 31 Aug 1997, Sunthiti Patchararungruang wrote: > I am a master student of Asian Institute of Technology. > I do my thesis on a FreeBSD system. My thesis is in the topic > of computer network. I need to access the BPF device. I have > found that the information about it is very rarely available. > I can found a paper about BPF implementation in > "ftp://ftp.ee.lbl.gov" and a demo-program, tcpdump, which is > implement the BPF only in reading from it. However, I need to > write a complete IP packets-already have headers and options- > to a specified network interface without minding about the interface > topology. Someone in FreeBSD.org advised me to use the BPF. > Therefore, I need to know where I can get the information about > it. I can accept all source of information including text books. The bpf(4) man page would be a good place to start. Questions about the interface should be routed to hackers@freebsd.org. tcpdump acutally uses a library to access the bpf, and was recommended on -hackers recently that you use that instead of trying to grok the device directly since the bpf interface is a little bit twisted. You'll have to ask them again though. Doug White | University of Oregon Internet: dwhite@resnet.uoregon.edu | Residence Networking Assistant http://gladstone.uoregon.edu/~dwhite | Computer Science Major Spam routed to /dev/null by Procmail | Death to Cyberpromo