From owner-freebsd-net Sat Feb 23 4:28:34 2002 Delivered-To: freebsd-net@freebsd.org Received: from rwcrmhc51.attbi.com (rwcrmhc51.attbi.com [204.127.198.38]) by hub.freebsd.org (Postfix) with ESMTP id 007C037B402; Sat, 23 Feb 2002 04:28:31 -0800 (PST) Received: from blossom.cjclark.org ([12.234.91.48]) by rwcrmhc51.attbi.com (InterMail vM.4.01.03.27 201-229-121-127-20010626) with ESMTP id <20020223122830.MQUV2626.rwcrmhc51.attbi.com@blossom.cjclark.org>; Sat, 23 Feb 2002 12:28:30 +0000 Received: (from cjc@localhost) by blossom.cjclark.org (8.11.6/8.11.6) id g1NCST217289; Sat, 23 Feb 2002 04:28:29 -0800 (PST) (envelope-from cjc) Date: Sat, 23 Feb 2002 04:28:28 -0800 From: "Crist J. Clark" To: Ruslan Ermilov Cc: net@FreeBSD.ORG Subject: Re: TCP Connections to a Broadcast Address Message-ID: <20020223042828.E16048@blossom.cjclark.org> References: <20020222022626.A83807@blossom.cjclark.org> <20020223115033.GB47437@sunbay.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20020223115033.GB47437@sunbay.com>; from ru@FreeBSD.ORG on Sat, Feb 23, 2002 at 01:50:33PM +0200 X-URL: http://people.freebsd.org/~cjc/ Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Sat, Feb 23, 2002 at 01:50:33PM +0200, Ruslan Ermilov wrote: [snip] > Nice catch! Igor M Podlesny , PR misc/35022, caught it. I just analyzed it. [snip] > The patch is incomplete (see dropwithreset below). Here's the tcp_input.c > part of the original delta that introduced this bug: I considered what to do for non-SYN segments, but I didn't see a requirement in the standards (I may have missed it), so I just didn't touch it. > : Script started on Sat Feb 23 13:37:18 2002 > : $ sccs prs -r7.35 tcp_input.c > : D 7.35 93/04/07 19:28:08 sklower 159 158 00007/00003/01623 > : MRs: > : COMMENTS: > : Mostly changes recommended by jch for variable subnets & multiple > : IP addresses per physical interface. May require further work. [snip] > I think you should just back the CSRG revision 7.35 out of tcp_input.c, > mentioning what was wrong with removing in_broadcast() check. Where'd you pull this out? I'll integrate this version. > route add -net 192.168.4 192.168.1.1 > ping 192.168.4.255 > > on a directly attached 192.168.1 network isn't a "malicious use". Then I would put that under the "misconfigured" header. The machine you are pinging from would have to be local to 192.168.4.0/24 also, why are you routing it through 192.168.1.1? But there may be some situations that I have not considered where one might wish to do that. Anyway, if there are legit configurations where this rears its head, it is even worse. -- Crist J. Clark | cjclark@alum.mit.edu | cjclark@jhu.edu http://people.freebsd.org/~cjc/ | cjc@freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message