On Tue, Aug 15, 2017 at 01:28:26AM +0300, Vladimir Medvedkin wrote: > 2017-08-14 13:51 GMT+03:00 Bruce Richardson <bruce.richard...@intel.com>: > > > On Tue, Jul 11, 2017 at 07:33:04PM +0000, Medvedkin Vladimir wrote: > > > Hi, > > > > > > I want to introduce new library for ip routing lookup that have some > > advantages > > > over current LPM library. In short: > > > - Increases the speed of control plane operations against lpm such > > as > > > adding/deleting routes > > > - Adds abstraction from dataplane algorythms, so it is possible to > > add > > > different ip route lookup algorythms such as > > DXR/poptrie/lpc-trie/etc > > > in addition to current dir24_8 > > > - It is possible to keep user defined application specific > > additional > > > information in struct rte_rib_v4_node which represents route > > entry. > > > It can be next hop/set of next hops (i.e. active and feasible), > > > pointers to link rte_rib_v4_node based on some criteria (i.e. > > next_hop), > > > plenty of additional control plane information. > > > - For dir24_8 implementation it is possible to remove > > rte_lpm_tbl_entry.depth > > > field that helps to save 6 bits. > > > - Also new dir24_8 implementation supports different next_hop sizes > > > (1/2/4/8 bytes per next hop) > > > > > > It would be nice to hear your opinion. The draft is below. > > > > > > Medvedkin Vladimir (1): > > > lib/rib: Add Routing Information Base library > > > > > > > On reading this patch and then having discussion with you offline, it > > appears there are two major new elements in this patchset: > > > > 1. a re-implementation of LPM, with the major advantage of having a > > flexible data-size > > 2. a separate control plane structure that is designed to fit on top off > > possibly multiple lookup structures for the data plane > > > > Is this correct? > > > Correct > > > > > For the first part, I don't think we should carry about two separate LPM > > implementations, but rather look to take the improvements in your > > version back into the existing lib. [Or else replace the existing one, > > but I prefer pulling the new stuff into it, so as to keep backward > > compatibility] > > > > > For the second part, perhaps you could expand a bit more on the thought > > here, and explain what all different data plane implementations would > > fit under it. Would, for instance a hash-lookup work? In that case, what > > would the data plane APIs be, and the control plane ones. > > > > I'm not sure for _all_ data plane implementations, but from my point of > view compressed prefix trie (rte_rib structure) could be useful at least > for dir24_8, dxr, bitmap handling. Concerning to hash lookup, it depends on > algorithm (array of hash tables indexed by mask length, unrolling prefix to > number of /32). > Perhaps it is better to waive the abstraction and make LPM as primary > struct that keeps rte_rib inside (instead of rules_tbl[ ]). > In that case rte_rib becomes side structure and it's API only for working > with a trie. LPM's API remains the same (except next_hop size and LPM > creation). > > What is the advantage of using the rte_rib for control plane access over the existing rules table structure. Are not the basic operations needed for adding/removing/looking-up rules supported by both?
/Bruce
