From owner-freebsd-bugs Sun Feb 17 1:20: 5 2002 Delivered-To: freebsd-bugs@hub.freebsd.org Received: from freefall.freebsd.org (freefall.FreeBSD.org [216.136.204.21]) by hub.freebsd.org (Postfix) with ESMTP id E236737B417 for ; Sun, 17 Feb 2002 01:20:01 -0800 (PST) Received: (from gnats@localhost) by freefall.freebsd.org (8.11.6/8.11.6) id g1H9K1o72227; Sun, 17 Feb 2002 01:20:01 -0800 (PST) (envelope-from gnats) Date: Sun, 17 Feb 2002 01:20:01 -0800 (PST) Message-Id: <200202170920.g1H9K1o72227@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org Cc: From: "Crist J. Clark" Subject: Re: misc/35022: network broadcast addresses may be used for communications with the system just as well as if it was her own. Reply-To: "Crist J. Clark" Sender: owner-freebsd-bugs@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org The following reply was made to PR misc/35022; it has been noted by GNATS. From: "Crist J. Clark" To: Igor M Podlesny Cc: freebsd-gnats-submit@FreeBSD.ORG Subject: Re: misc/35022: network broadcast addresses may be used for communications with the system just as well as if it was her own. Date: Sun, 17 Feb 2002 01:14:58 -0800 On Sun, Feb 17, 2002 at 03:51:23PM +0700, Igor M Podlesny wrote: [snip] > > But there was mention of another behavior that is a bug. You _can_ > > establish a TCP connection to a FreeBSD machine with the destination > > being the broadcast address. This is oh so Very Very Bad. And it > > breaks the Standard (the Standard being everyone's favorite, RFC1122), > > > 4.2.3.10 Remote Address Validation > > > ... > > > A TCP implementation MUST silently discard an incoming SYN > > segment that is addressed to a broadcast or multicast > > address. > > yep. > > BTW it declares TCP only? No, for IP datagrams in general, For most purposes, a datagram addressed to a broadcast or multicast destination is processed as if it had been addressed to one of the host's IP addresses; As for UDP, it says nothing specific about how to handle incoming datagrams with the broadcast address as the destination (it's up to the application). However, it does mention, UDP is used by applications that do not require the level of service of TCP or that wish to use communications services (e.g., multicast or broadcast delivery) not available from TCP. -- 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-bugs" in the body of the message