From owner-freebsd-mips@FreeBSD.ORG Thu Jan 13 06:53:36 2011 Return-Path: Delivered-To: freebsd-mips@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9E464106564A; Thu, 13 Jan 2011 06:53:36 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-wy0-f182.google.com (mail-wy0-f182.google.com [74.125.82.182]) by mx1.freebsd.org (Postfix) with ESMTP id D86528FC15; Thu, 13 Jan 2011 06:53:35 +0000 (UTC) Received: by wyf19 with SMTP id 19so1403376wyf.13 for ; Wed, 12 Jan 2011 22:53:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=NJn/IvrZfXUx2B0AXsFAhm4MlpGNT5zkzhUTqRgJjqA=; b=OjKLzfrTI2jl4XXsaWPa+nDW9bmhgXosqcBNy+ghTT7BpVJe8ihBee6ZPJwAcniKP4 bxpfvST4WdJ3yEkukDbH9/wzSxOeZOrLN0/2WuQqbzRLVdKqu6jB6iqaXYpi3kjF8Yz/ M1kGF5AN3ammss9L/sZC1KwVo7dgP8ZJUzHJs= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=fJqJl9U++kOpR9kJ84Kog+vP859eo/8KmwBTh6rbNrXwEvDfayux/NGU4Cm4eTIf7/ Mm18jS1n0Lk8rR3AhoFyDa3IapETffFo/sQl0I4lnadyGqdxxV/ziF8sfVzZ7xpR2HUI MUAZYy2XOfntc0NgYrY9bohNInYbU9l6LRSmI= MIME-Version: 1.0 Received: by 10.216.170.213 with SMTP id p63mr303558wel.37.1294901614574; Wed, 12 Jan 2011 22:53:34 -0800 (PST) Sender: adrian.chadd@gmail.com Received: by 10.216.159.201 with HTTP; Wed, 12 Jan 2011 22:53:34 -0800 (PST) In-Reply-To: References: Date: Thu, 13 Jan 2011 14:53:34 +0800 X-Google-Sender-Auth: lkuBx-KCQ2qB8oqOx87nR5nbxpQ Message-ID: From: Adrian Chadd To: "Jayachandran C." Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: freebsd-net@freebsd.org, freebsd-mips@freebsd.org Subject: Re: capturing packet from wlan0 with netgraph? X-BeenThere: freebsd-mips@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting FreeBSD to MIPS List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 13 Jan 2011 06:53:36 -0000 I've encountered this before. The mbuf's there aren't always aligned at this point. Adrian On 13 January 2011 14:17, Jayachandran C. wrote: > On Thu, Jan 13, 2011 at 11:08 AM, Adrian Chadd wrote= : >> Find out what the address is that's causing the problem. There's >> plenty of places where unaligned mbuf's exist in the IP code and >> aren't correctly realigned before being touched. >> >> MIPS people - is "address error" an alignment problem? > > Address error can be an alignment problem (or some other cases like > accessing kernel address from userspace). > > But looking at the crash, it certainly seems like in ip_input, the line > =A0 =A0 435 =A0 =A0 =A0 =A0 if (ip->ip_v !=3D IPVERSION) { > > got a bad address for the ip pointer. > > The output of 'show registers' at the ddb prompt would be useful to > debug further. > > >> On 30 December 2010 21:47, Monthadar Al Jaberi wro= te: >>> Hi, >>> >>> I have an idea in my head and would like to know if it is possible. >>> >>> I want to simulate and test the net80211 mesh code in FreeBSD Current. >>> I have an RSPRO board with 3 atheros cards. >>> >>> My =A0basic idea is to run three jails each having its own network >>> stack, and redirect all data packets coming out/in of the wlan driver >>> to a Server running a home brew application that simulates the medium. >>> That would be great, right? Realtime unchanged code to test, running >>> different application in their own jails. >>> >>> So first I started to test netgraph with a simple test case, I want to >>> receive all packets from one wireless card and see the data in >>> wireshark or tcpdump... >>> >>> This is my netgraph code: >>> mkpeer wlan0: hub lower hook0 >>> name wlan0:lower hub >>> connect hub: wlan0: hook1 upper >>> connect hub: arge0: hook2 lower >>> >>> >>> So if I understood man ng_ether correct, this should capture >>> everything from wlan and redirect to ethernet cable. >>> >>> But I get a panic after a couple of seconds: >>> Trap cause =3D 4 (address error (load or I-fetch) - kernel mode) >>> [ thread pid 11 tid 100037 ] >>> Stopped at =A0 =A0 =A0ip_input+0xd8: =A0lw =A0 =A0 =A0v0,0(s0) >>> >>> I suspect that data flows to all hooks of the hub, and that is a bad >>> thing right? Need to create a special hub node to filter data? Or >>> maybe use two ethernet cables for out resp. in? >>> >>> Is it even possible to do what I want? Or am I thinking wrong? And is >>> there a simpler way? >>> >>> What I want is to test mesh code in a bunch of FreeBSD systems without >>> moving the hardware, one could just stack RSPROs and connected them a >>> big switch and a PC. >>> Hope was I clear in my thoughts. >>> >>> Best regards, >>> -- >>> //Monthadar Al Jaberi > > JC. >