From owner-freebsd-hackers@FreeBSD.ORG  Tue Jun 29 17:07:25 2004
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id C62E116A4CE
	for <hackers@freebsd.org>; Tue, 29 Jun 2004 17:07:25 +0000 (GMT)
Received: from smtp.netli.com (ip2-pal-focal.netli.com [66.243.52.2])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 7A1ED43D31
	for <hackers@freebsd.org>; Tue, 29 Jun 2004 17:07:25 +0000 (GMT)
	(envelope-from vlm@netli.com)
Received: (qmail 9113 invoked by uid 84); 29 Jun 2004 17:07:07 -0000
Received: from vlm@netli.com by l3-1 with qmail-scanner-0.96 (uvscan:
	v4.1.40/v4121. . Clean. Processed in 0.174024 secs); 29 Jun 2004 17:07:07
	-0000
Received: from unknown (HELO netli.com) (172.17.1.12)
  by mx01-pal-lan.netli.lan with SMTP; 29 Jun 2004 17:07:07 -0000
Message-ID: <40E1A1F8.90003@netli.com>
Date: Tue, 29 Jun 2004 10:08:08 -0700
From: Lev Walkin <vlm@netli.com>
Organization: Netli, Inc.
User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.6) Gecko/20040307
X-Accept-Language: ru, en-us, en
MIME-Version: 1.0
To: Ivan Voras <ivoras@fer.hr>
References: <40E177DB.6070506@fer.hr>
In-Reply-To: <40E177DB.6070506@fer.hr>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
cc: hackers@freebsd.org
Subject: Re: Peeking BPF
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 29 Jun 2004 17:07:25 -0000

Ivan Voras wrote:
> 
> I need to convert this code:
> 
> ret = recvfrom(thisint->sockInt, &resultframe, 1520, MSG_PEEK, 0, 0);
> if (ret > 0) return TRUE;
> 
> to use BPF. Essentialy, how to find out if a packet is available over 
> the BPF interface?

try to read() it and read() will hang there until there is data in it.
alternatively, use poll() or select() to check for readability event.

	char resultBuffer[65536];
	ret = read(thisint->bpfInt, resultBuffer, sizeof(resultBuffer));
	if(ret > 0) return TRUE;


-- 
Lev Walkin
vlm@netli.com