From: Renato Westphal <renato@opensourcerouting.org>
Date: Wed, 20 Sep 2017 22:04:26 +0000 (-0300)
Subject: zebra: fix detection of duplicate kernel routes (ECMP version)
X-Git-Tag: frr-4.0-dev~277^2~1
X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=844b3a8748cce00fdcc913d7ff89f181b7fd9dd1;p=mirror%2Ffrr.git

zebra: fix detection of duplicate kernel routes (ECMP version)

Fixes the following bug:
% ip route add 50.0.0.0/8 nexthop via 10.0.1.2 nexthop via 10.0.2.2
% ip route replace 50.0.0.0/8 nexthop via 10.0.1.3 nexthop via 10.0.2.3
% ip route replace 50.0.0.0/8 nexthop via 10.0.1.4 nexthop via 10.0.2.4
%
% vtysh -c "show ip route"
[snip]
K * 50.0.0.0/8 [0/0] via 10.0.1.4, rt1-eth1, 00:00:00
  *                  via 10.0.2.4, rt1-eth2, 00:00:00
K * 50.0.0.0/8 [0/0] via 10.0.1.3, rt1-eth1, 00:00:10
  *                  via 10.0.2.3, rt1-eth2, 00:00:10
K>* 50.0.0.0/8 [0/0] via 10.0.1.2, rt1-eth1, 00:00:24
  *                  via 10.0.2.2, rt1-eth2, 00:00:24

Commit a3d18ce6 fixed a similar problem for single-path routes.

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
---

diff --git a/zebra/zebra_rib.c b/zebra/zebra_rib.c
index bc39ffeacf..13057e0ae4 100644
--- a/zebra/zebra_rib.c
+++ b/zebra/zebra_rib.c
@@ -2260,7 +2260,11 @@ int rib_add_multipath(afi_t afi, safi_t safi, struct prefix *p,
 		if (same->type == ZEBRA_ROUTE_KERNEL &&
 		    same->metric != re->metric)
 			continue;
-		if (!RIB_SYSTEM_ROUTE(same))
+		/*
+		 * We should allow duplicate connected routes because of
+		 * IPv6 link-local routes and unnumbered interfaces on Linux.
+		 */
+		if (same->type != ZEBRA_ROUTE_CONNECT)
 			break;
 	}