From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: Re: [RFC net-next 0/3] IP imposition of per-nh MPLS encap Date: Tue, 02 Jun 2015 13:30:50 -0500 Message-ID: <87y4k2ufmt.fsf@x220.int.ebiederm.org> References: <1433177175-16775-1-git-send-email-rshearma@brocade.com> <556DCC4C.7010808@cumulusnetworks.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Robert Shearman , netdev@vger.kernel.org, Thomas Graf , Vivek Venkatraman To: roopa Return-path: Received: from out02.mta.xmission.com ([166.70.13.232]:39958 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753357AbbFBSfx (ORCPT ); Tue, 2 Jun 2015 14:35:53 -0400 In-Reply-To: <556DCC4C.7010808@cumulusnetworks.com> (roopa@cumulusnetworks.com's message of "Tue, 02 Jun 2015 08:31:24 -0700") Sender: netdev-owner@vger.kernel.org List-ID: roopa writes: > On 6/1/15, 9:46 AM, Robert Shearman wrote: >> In order to be able to function as a Label Edge Router in an MPLS >> network, it is necessary to be able to take IP packets and impose an >> MPLS encap and forward them out. The traditional approach of setting >> up an interface for each "tunnel" endpoint doesn't scale for the >> common MPLS use-cases where each IP route tends to be assigned a >> different label as encap. >> >> The solution suggested here for further discussion is to provide the >> facility to define encap data on a per-nexthop basis using a new >> netlink attribue, RTA_ENCAP, which would be opaque to the IPv4/IPv6 >> forwarding code, but interpreted by the virtual interface assigned to >> the nexthop. >> >> A new ipmpls interface type is defined to show the use of this >> facility to allow IP packets to be imposed with an MPLS >> encap. However, the facility is designed to be general enough to be >> used by any encapsulation/tunneling mechanism that has similar >> requirements of high-scale, high-variation-of-encap. >> >> RFC because: >> - IPv6 side not implemented >> - struct rtable shouldn't be bloated by pointer+uint >> - Hasn't been thoroughly tested yet >> >> Robert Shearman (3): >> net: infra for per-nexthop encap data >> ipv4: storing and retrieval of per-nexthop encap >> mpls: new ipmpls device for encapsulating IP packets as mpls >> >> > Glad to see these patches!. > I have a similar series i have been working on...but no netdevice. > A set of ops similar to iptun_encaps and I store encap data in fib_nh > and in ip_route_output_slow i point the dst.output to the output func provided > by one of the encap ops. > > I see the advantages of using a netdevice...and i see this align with patches > from thomas. roopa I think I would prefer your patches. I thinking using a netdevice the way Robert is proposing is quite possibly a mess, from a scalability stand point. Do you mean ip_route_input_slow? There is no ip_route_output_slow. Eric