From owner-freebsd-net  Mon Feb 26 13:19:18 2001
Delivered-To: freebsd-net@freebsd.org
Received: from samar.sasi.com (samar.sasken.com [164.164.56.2])
	by hub.freebsd.org (Postfix) with ESMTP id 6D31337B503
	for <net@freebsd.org>; Mon, 26 Feb 2001 13:19:13 -0800 (PST)
	(envelope-from sseth@sasken.com)
Received: from samar (samar.sasi.com [164.164.56.2])
	by samar.sasi.com (8.9.3/8.9.3) with SMTP id CAA27027
	for <net@freebsd.org>; Tue, 27 Feb 2001 02:49:08 +0530 (IST)
Received: from suns3.sasi.com ([10.0.36.3]) by samar.sasi.com; Tue, 27 Feb 2001 02:49:06 +0000 (IST)
Received: from localhost (sseth@localhost)
	by suns3.sasi.com (8.9.3/8.9.3) with ESMTP id CAA29417
	for <net@freebsd.org>; Tue, 27 Feb 2001 02:49:05 +0530 (IST)
Date: Tue, 27 Feb 2001 02:49:05 +0530 (IST)
From: Satyajeet Seth <sseth@sasken.com>
To: <net@freebsd.org>
Subject: Problem in configuring netgraph
Message-ID: <Pine.GSO.4.30.0102270141460.28244-100000@suns3.sasi.com>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Sender: owner-freebsd-net@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.org

Hi

I tried to use ng_ether and ng_bpf as follows:


fxp0(lower) --- (bhook)[bpf](nomatch)(hook1)----(upper)fxp0
		       [   ]( match )(hook2)----not connected

$ ngctl mkpeer fxp0: bpf divert bhook

$ ngctl name fxp0:divert bpf0

$ ngctl
+  msg bpf0: setprogram { thisHook="bhook" ifMatch="hook2"
   ifNotMatch="hook1" bpf_prog_len=1 bpf_prog=[ { code=6 } ] }

Now 'nghook -a bpf0: hook1' shows output while 'nghook -a bpf0: hook2'
doesn't.

$ ngctl connect fxp0: bpf0: upper hook1

1. After this I am unable to ping any of the lan machines.
 Could you suggest what I could be doing wrong?

2. I am writing a BPF program(for filtering packets destined to particular
MAC addresses) by converting instructions like:
 BPF_STMT(BPF_LD+BPF_H+BPF_ABS,12), BPF_STMT(BPF_RET+BPF_K,0)
into:
[ {code=28 jt=0 jf=0 k=0x0c} {code=6 jt=0 jf=0 k=0}]
After seeing the definitions of BPF_STMT,BPF_LD etc. in /sys/net/bpf.h. Is
this the correct way?

3. I noticed a problem that the filter could not be set as :
ngctl msg bpf0: setprogram {...}
It gave the message:
ngctl: send msg: Invalid argument

I am using FreeBSD 4.1.

Thanks
Satya


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-net" in the body of the message