From owner-freebsd-current Tue May 19 11:01:55 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id LAA07526 for freebsd-current-outgoing; Tue, 19 May 1998 11:01:55 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from labinfo.iet.unipi.it (labinfo.iet.unipi.it [131.114.9.5]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id LAA07508; Tue, 19 May 1998 11:01:43 -0700 (PDT) (envelope-from luigi@labinfo.iet.unipi.it) Received: from localhost (luigi@localhost) by labinfo.iet.unipi.it (8.6.5/8.6.5) id SAA09928; Tue, 19 May 1998 18:18:22 +0200 From: Luigi Rizzo Message-Id: <199805191618.SAA09928@labinfo.iet.unipi.it> Subject: Re: cvs commit: src/sys/conf files src/sys/net if_ethersubr.c if_fddisubr.c if_ppp.c src/sys/netinet ip_flow.c in.h in_var.h ip_OR To: eivind@yes.no (Eivind Eklund) Date: Tue, 19 May 1998 18:18:22 +0200 (MET DST) Cc: dg@FreeBSD.ORG, current@FreeBSD.ORG In-Reply-To: <19980519163734.18175@follo.net> from "Eivind Eklund" at May 19, 98 04:37:15 pm X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > Log: > > Added fast IP forwarding code by Matt Thomas via > > NetBSD, ported to FreeBSD by Pierre Beyssac and > > minorly tweaked by me. > > This is a standard part of FreeBSD, but must be enabled with: > > "sysctl -w net.inet.ip.fastforwarding=1" ...and of course forwarding must > > Why is this? What are the downsides - just that it is temporary code? not just that. It completely bypasses the ipfw code. It is also missing some checks on forwarded packets (e.g. IP header checksum is not tested, although i don't know if it is mandatory, and in any case this is easier to fix). It contains lots of nice ideas though. I was wondering if we could put at least some into the standard path as well. E.g. when forwarding a packet, there is a call to ip_output() with the IP_FORWARDING flag set. We could easily use this info to skip some checks and work in ip_output (e.g. avoid recomputing the checksum). Also flow through the firewall code can be optimized since the packet has been already classified. cheers luigi -----------------------------+-------------------------------------- Luigi Rizzo | Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it | Universita' di Pisa tel: +39-50-568533 | via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 | http://www.iet.unipi.it/~luigi/ _____________________________|______________________________________ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message