From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: Re: Trying to implement secondary loopback Date: Wed, 13 Mar 2013 13:46:07 -0700 Message-ID: <87r4jjav00.fsf@xmission.com> References: <513F1A17.1000809@hhi.fraunhofer.de> <3D7E565A361FB844A410A5EFCDD7BA4002ECF5@MXSRV3.fe.hhi.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: richard -rw- weinberger , "netdev\@vger.kernel.org" , "davem\@davemloft.net" , "edumazet\@google.com" , "herbert\@gondor.apana.org.au" To: "Martitz\, Thomas" Return-path: Received: from out03.mta.xmission.com ([166.70.13.233]:40921 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934255Ab3CMUqU convert rfc822-to-8bit (ORCPT ); Wed, 13 Mar 2013 16:46:20 -0400 In-Reply-To: <3D7E565A361FB844A410A5EFCDD7BA4002ECF5@MXSRV3.fe.hhi.de> (Thomas Martitz's message of "Wed, 13 Mar 2013 20:38:08 +0000") Sender: netdev-owner@vger.kernel.org List-ID: "Martitz, Thomas" writes: >> >> ________________________________________ >> Von: richard -rw- weinberger [richard.weinberger@gmail.com] >> Gesendet: Mittwoch, 13. M=C3=A4rz 2013 12:13 >> An: Martitz, Thomas >> Cc: netdev@vger.kernel.org; davem@davemloft.net; edumazet@google.com= ; herbert@gondor.apana.org.au; ebiederm@xmission.com >> Betreff: Re: Trying to implement secondary loopback >> >> > >> > So my questions are: >> > * Is this on purpose/expected? >> > * Is there anyway around it so that I can have a custom loopback i= nterface >> > without touching lo's functionality. >> > * Generally, what's the proper way (if any) implement a secondary = loopback >> > interface? >> >> The only really question that matters is, why do you need a second >> loopback interface? >> Why can't you use any other pseudo interface? >> > > What pseudo interface do you mean? I'm not aware of alternative pseud= o interfaces. > > I'm developing a NIC and a driver for it. Thus I'm implementing the i= nterface. I'm trying to implement an interface that does exactly do wha= t loopback does except that I want to extend the loopback path to PCIe.= This is for testing & validation purposes. > > I tried to implement an interface that's doesn't advertise as > such. But the data transfer didn't go through my code. My test app is > a simple client/server setup in a single process that sends/receive > data to/on 127.0.0.1. The easy solution is to setup two network namespaces and two nics. And transmit data from one network namespace to another, through your nics. Eric