commit 3334bab0d96b2d7064111e025ff6294d6a32d026
author Job Snijders <job@instituut.net> Fri Jan 20 14:47:12 2017 +0000
committer Paul Jakma <paul@quagga.net> Fri Jan 27 14:53:20 2017 +0000
tree 665e079e1643db0ae957acadfa5e5497f0f645ac
parent f2a4b8fffb1f771371d6bfc425e7a69a14057b06

bgpd: Add support for BGP Large Communities

As described by Michael Lambert <lambert@psc.edu>  to the list:

  Traditional communities are four-octet entities to support two-octet ASNs
  and are usually represented as <asn>:<data>.  Large communities are an
  enhancement to support four-octet ASNs and are 12 octets long, represented
  as <asn>:<data-1>:<data-2>.

  This issue has been tracked in quagga bugzilla ticket #875, which documents
  some of the usage and indicates that some testing has been done.

TODO: Documentation - update doc/bgpd.texi.

* bgp_attr.{c,h}: Add BGP_ATTR_LARGE_COMMUNITIES codepoint. Add
  (struct lcommunity *) to (struct bgp_attr_extra).
* bgp_clist.{c,h}: Large community codepoints and routines.
* bgp_route.c: Display support.
* bgp_routemap.c: 'match lcommunity', 'set large-community' and
  'set large-comm-list'
* bgp_vty.c: Peer configuration, add 'large' to 'neighbor send-community ..'.
  Add "show ip bgp large-community", ""ip large-community-list ...".

Authors: Keyur Patel <keyur@arrcus.com>
         Job Snijders <job@instituut.net>

bgpd/bgp_mpath.c

diff --git a/bgpd/bgp_mpath.c b/bgpd/bgp_mpath.c
index 6465aad..8195e47 100644
--- a/bgpd/bgp_mpath.c
+++ b/bgpd/bgp_mpath.c
@@ -38,6 +38,7 @@
 #include "bgpd/bgp_aspath.h"
 #include "bgpd/bgp_community.h"
 #include "bgpd/bgp_ecommunity.h"
+#include "bgpd/bgp_lcommunity.h"
 #include "bgpd/bgp_mpath.h"
 
 bool
@@ -647,6 +648,7 @@
   u_char origin, attr_chg;
   struct community *community, *commerge;
   struct ecommunity *ecomm, *ecommerge;
+  struct lcommunity *lcomm, *lcommerge;
   struct attr_extra *ae;
   struct attr attr = { 0 };
 
@@ -711,6 +713,8 @@
   ae = attr.extra;
   ecomm = (ae && ae->ecommunity) ? ecommunity_dup (ae->ecommunity) : NULL;
 
+  lcomm = (ae && ae->lcommunity) ? lcommunity_dup (ae->lcommunity) : NULL;
+
   for (mpinfo = bgp_info_mpath_first (new_best); mpinfo;
        mpinfo = bgp_info_mpath_next (mpinfo))
     {
@@ -745,6 +749,18 @@
           else
             ecomm = ecommunity_dup (ae->ecommunity);
         }
+
+      if (ae && ae->lcommunity)
+        {
+          if (lcomm)
+            {
+              lcommerge = lcommunity_merge (lcomm, ae->lcommunity);
+              lcomm = lcommunity_uniq_sort (lcommerge);
+              lcommunity_free (&lcommerge);
+            }
+          else
+            lcomm = lcommunity_dup (ae->lcommunity);
+        }
     }
 
   attr.aspath = aspath;