Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262568AbVCVIeP (ORCPT ); Tue, 22 Mar 2005 03:34:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262567AbVCVIeO (ORCPT ); Tue, 22 Mar 2005 03:34:14 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:60838 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S262564AbVCVId4 (ORCPT ); Tue, 22 Mar 2005 03:33:56 -0500 Subject: Re: mmap/munmap bug From: Arjan van de Ven To: Hayim Shaul Cc: Gleb Natapov , linux-kernel@vger.kernel.org In-Reply-To: References: <1111430042.6952.70.camel@laptopd505.fenrus.org> <20050322075658.GA32445@minantech.com> <1111478733.7096.36.camel@laptopd505.fenrus.org> Content-Type: text/plain Date: Tue, 22 Mar 2005 09:33:49 +0100 Message-Id: <1111480429.7096.47.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.0.2 (2.0.2-3) Content-Transfer-Encoding: 7bit X-Spam-Score: 4.1 (++++) X-Spam-Report: SpamAssassin version 2.63 on pentafluge.infradead.org summary: Content analysis details: (4.1 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.3 RCVD_NUMERIC_HELO Received: contains a numeric HELO 1.1 RCVD_IN_DSBL RBL: Received via a relay in list.dsbl.org [] 2.5 RCVD_IN_DYNABLOCK RBL: Sent directly from dynamic IP address [80.57.133.107 listed in dnsbl.sorbs.net] 0.1 RCVD_IN_SORBS RBL: SORBS: sender is listed in SORBS [80.57.133.107 listed in dnsbl.sorbs.net] X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1277 Lines: 29 On Tue, 2005-03-22 at 10:23 +0200, Hayim Shaul wrote: > >> Does it support zero copy not only for send but also for receive? Can we > >> receive packets directly to userspace buffers? > > > > that it can't currently, but without some major protocol stack rework > > that's not going to be easy. If you want to help do that work, > > excellent! Be sure to contact the people on net-dev mailinglist since > > they are the ones having looked at this previously. > > My case is simpler, as the application I attend it to is similar to a NAT. > A packet comes in, a little alternation of the headers and off it goes > again. So there's no TCP-stack or anything. > > What I thought of doing, is map the skbuff to user-space. Have the > user-application alter the headers. Send the (same) skbuff from > kernel-space. > > Does there exist anything equivalent? yes; netfilter has facilities for this actually afaik. tcpdump also uses something like this (but only in one direction), it mmaps some ringbuffer with incomming packets. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/