-----Original Message----- From: Ben Pfaff [mailto:b...@nicira.com] Sent: Friday, May 25, 2012 9:32 AM To: Kerur, Ravi Cc: dev@openvswitch.org Subject: Re: [ovs-dev] MPLS and VLAN QinQ patch
On Fri, May 25, 2012 at 01:24:00AM +0200, ravi.ke...@telekom.com wrote: > On Thu, May 24, 2012 at 11:58:53PM +0200, ravi.ke...@telekom.com wrote: > > Ben Pfaff writes: > > > get_l3_ttl_and_tos() > > > -------------------- > > > > > > Why does get_l3_ttl_and_tos() consider an unknown IP version as > > > success, with a default? This seems odd. > > > > To handle non-IP traffic i.e push/pop MPLS over non-IP traffic e.g. > > ARP(practical?), VPLS. I had also mentioned in previous discussion > > that MPLS ttl actions will not work for these type of traffic but > > other actions lke push_mpls,pop_mpls, set_mpls_label/set_mpls_tc > > would be. In this function I keep them to default for non-IP traffic. > > But that only comes up in one situation: copying the TTL inward or outward > when there is exactly one MPLS label. In other situations (pushing an MPLS > label or popping one) we know the correct inner Ethertype either because it's > in the packet or because it's an argument to the action. When we know it, we > should use it. > > <rk> Cases for multiple MPLS headers currently happen only at Provider core > routers and yes in that case we don't have to worry, I was thinking more in > terms of Provider-Edge or MPLS termination point. For those multiple MPLS > label case it is already handled and I use existing mpls header to copy. I > will closely look at it one more time probably I am missing your point. I > think you are probably saying extract ethtype from packet and use it to > derive ttl and tos? Yes, that's what I had in mind. <rk> That's the approach I have taken for kernel code. For userspace, I just thought of using packet->l3 which is readily available(one can argue the same for kernel as well with skb's). Anyways I will modify the code. Thanks, Ravi Thanks, Ben. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
