From owner-freebsd-net Sun Nov 3 19:39:30 2002 Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A303D37B401 for ; Sun, 3 Nov 2002 19:39:29 -0800 (PST) Received: from xorpc.icir.org (xorpc.icir.org [192.150.187.68]) by mx1.FreeBSD.org (Postfix) with ESMTP id 65E6143E4A for ; Sun, 3 Nov 2002 19:39:29 -0800 (PST) (envelope-from rizzo@xorpc.icir.org) Received: from xorpc.icir.org (localhost [127.0.0.1]) by xorpc.icir.org (8.12.3/8.12.3) with ESMTP id gA43dNAh034821; Sun, 3 Nov 2002 19:39:23 -0800 (PST) (envelope-from rizzo@xorpc.icir.org) Received: (from rizzo@localhost) by xorpc.icir.org (8.12.3/8.12.3/Submit) id gA43dNmN034820; Sun, 3 Nov 2002 19:39:23 -0800 (PST) (envelope-from rizzo) Date: Sun, 3 Nov 2002 19:39:23 -0800 From: Luigi Rizzo To: net@freebsd.org Subject: fragmentation issues Message-ID: <20021103193923.A34675@xorpc.icir.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i 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 Hi, a colleague pointed out the following problem: the various forms of encapsulation of IP traffic might result in IP datagrams which are larger than the IP maximum datagram length (64k). The problem arises with the various IP-in-IP encapsulations (gif, maybe faith), with IPSEC, and with some multicast processing. I guess the correct way to solve the problem is to do some form of fragmentation _before_ adding the new header to the packet. This requires the replication of some code which is in ip_output(). So i was wondering if there objections if in the long term i pull out the fragmentation code from ip_output and put it into a separate procedure that can be used wherever is required without having to replicate the code (and maintain it). comments ? cheers luigi To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message