From owner-freebsd-net@FreeBSD.ORG Thu Oct 2 16:17:43 2003 Return-Path: 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 B6C4716A4B3 for ; Thu, 2 Oct 2003 16:17:43 -0700 (PDT) Received: from odin.ac.hmc.edu (Odin.AC.HMC.Edu [134.173.32.75]) by mx1.FreeBSD.org (Postfix) with ESMTP id F05FD43FB1 for ; Thu, 2 Oct 2003 16:17:42 -0700 (PDT) (envelope-from brdavis@odin.ac.hmc.edu) Received: from odin.ac.hmc.edu (IDENT:brdavis@localhost.localdomain [127.0.0.1]) by odin.ac.hmc.edu (8.12.9/8.12.3) with ESMTP id h92NHcDH010601; Thu, 2 Oct 2003 16:17:38 -0700 Received: (from brdavis@localhost) by odin.ac.hmc.edu (8.12.9/8.12.3/Submit) id h92NHcRA010600; Thu, 2 Oct 2003 16:17:38 -0700 Date: Thu, 2 Oct 2003 16:17:38 -0700 From: Brooks Davis To: Julian Elischer Message-ID: <20031002231738.GB4770@Odin.AC.HMC.Edu> References: <20031002230508.GA4770@Odin.AC.HMC.Edu> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="jq0ap7NbKX2Kqbes" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.4i X-Virus-Scanned: by amavisd-milter (http://amavis.org/) on odin.ac.hmc.edu cc: net@freebsd.org Subject: Re: ng_ip_input use case X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Oct 2003 23:17:43 -0000 --jq0ap7NbKX2Kqbes Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Oct 02, 2003 at 04:09:50PM -0700, Julian Elischer wrote: >=20 >=20 > On Thu, 2 Oct 2003, Brooks Davis wrote: >=20 > > On Thu, Oct 02, 2003 at 03:45:47PM -0700, Julian Elischer wrote: > > > On Thu, 2 Oct 2003, Vincent Jardin wrote: > > >=20 > > > > I read the man of ng_ip_input and the source code. However I do not > > > > understand what the use cases could be. Who is using it and what's > > > > for ? > > > > > > I have no idea what it is used for.. similar effect can be made by > > > using the ng_iface node, but I think that they didn't want a separate > > > interface for each packet source.. > > > > > > I suggest we ask brooks..(cc'd). I could imagine it somehow connected > > > with the 300 processor FreeBSD based cluster that he is working on at > > > hos job (especially as it has their copyright). > >=20 > > It was for a network emulator we were trying to build to allow us to > > run real, unmodified programs in an environment where each program > > was assumed to be an independent agent and the communication topology > > between agents changed in realtime. Each agent was to bind to the IP > > address of an IP-over-IP tunnel (gif on the FreeBSD end). We would then > > take the packets, mangle them slightly and send them off to the emulator > > (I think part of the goal was to let us use more or less off the shelf > > emulation gear in the middle without needing a workstation for each > > agent). When we got them back, we'd remanged them and stuff them back > > into the IP stack with ng_ip_input so it could decide which gif tunnel > > to send it back down. The emulation part of the project died when our > > funding for it dried up so we've not actually using this module for > > anything. >=20 > was there a reason to not use the ng_iface node? > (packets enterred on the INET hook if an iface node will be injected > into the ip stack) (from memory) Probably not. I didn't know netgraph all that well at the time so it wouldn't suprise me if I reinvented a wheel or two. -- Brooks --=20 Any statement of the form "X is the one, true Y" is FALSE. PGP fingerprint 655D 519C 26A7 82E7 2529 9BF0 5D8E 8BE9 F238 1AD4 --jq0ap7NbKX2Kqbes Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQE/fLIQXY6L6fI4GtQRAiVcAJ4l7QdprW2PEXcev9LFGUBk8+oZjgCfbK9z cZD9bi3PFDvP+C7h3rslLXE= =SaAZ -----END PGP SIGNATURE----- --jq0ap7NbKX2Kqbes--