commit 240c56f3a41cb7018460ba6e36c9b559c897e3d0
author David Lamparter <equinox@opensourcerouting.org> Tue Jan 06 19:53:24 2015 +0100
committer David Lamparter <equinox@opensourcerouting.org> Fri Jan 30 01:12:38 2015 +0100
tree 76e7bd769f19a7544b05e0070cdf058a5739eedb
parent 29ce93ebf6427d1d64eae8b385e36873e3ddcb88

zebra: make MRIB lookup behaviour switchable

depending on the usage scenario (and availability of multitopology IGP
protocols, which is currently zero in Quagga), different approaches of
Multicast RPF lookups are useful.

Reference behaviours from commercial vendors are urib-only/mrib-only
(Juniper, depending on inet.2 availability) and lowest-distance (Cisco).
As we are currently without MT IGP support, mrib-first seems the most
useful default for Quagga.

Cc: Everton Marques <everton.marques@gmail.com>
Cc: Balaji G <balajig81@gmail.com>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

zebra/zserv.c

diff --git a/zebra/zserv.c b/zebra/zserv.c
index e678f3a..afd722a 100644
--- a/zebra/zserv.c
+++ b/zebra/zserv.c
@@ -605,27 +605,13 @@
   Returns both route metric and protocol distance.
 */
 static int
-zsend_ipv4_nexthop_lookup_mrib (struct zserv *client, struct in_addr addr)
+zsend_ipv4_nexthop_lookup_mrib (struct zserv *client, struct in_addr addr,
+				struct rib *rib)
 {
   struct stream *s;
-  struct rib *rib;
   unsigned long nump;
   u_char num;
   struct nexthop *nexthop;
-  int skip_bgp = 0; /* bool */
-
-  /* Lookup nexthop. */
-  rib = rib_match_ipv4_safi (addr, SAFI_MULTICAST, skip_bgp, NULL);
-
-  if (IS_ZEBRA_DEBUG_PACKET && IS_ZEBRA_DEBUG_RECV)
-    zlog_debug("%s: %s mrib entry found.", __func__, rib ? "Matching" : "No matching");
-
-  if (!rib) {
-    /* Retry lookup with unicast rib */
-    rib = rib_match_ipv4_safi (addr, SAFI_UNICAST, skip_bgp);
-    if (IS_ZEBRA_DEBUG_PACKET && IS_ZEBRA_DEBUG_RECV)
-      zlog_debug("%s: %s rib entry found.", __func__, rib ? "Matching" : "No matching");
-  }
 
   /* Get output stream. */
   s = client->obuf;
@@ -1009,9 +995,11 @@
 zread_ipv4_nexthop_lookup_mrib (struct zserv *client, u_short length)
 {
   struct in_addr addr;
+  struct rib *rib;
 
   addr.s_addr = stream_get_ipv4 (client->ibuf);
-  return zsend_ipv4_nexthop_lookup_mrib (client, addr);
+  rib = rib_match_ipv4_multicast (addr, NULL);
+  return zsend_ipv4_nexthop_lookup_mrib (client, addr, rib);
 }
 
 /* Nexthop lookup for IPv4. */