commit 78243040fc60babf83ef02572ad7966ebd20192e
author Daniel Walton <dwalton@cumulusnetworks.com> Tue May 19 17:47:23 2015 -0700
committer Paul Jakma <paul.jakma@hpe.com> Tue Sep 13 10:36:46 2016 +0100
tree 3f75137aa154ba159ed9e220b4b6e121bbec3344
parent d0aa6e8b222f44949b0a190d8ff70d90333b775c

bgpd: iBGP multipath is broken if 'bgp deterministic-med' is enabled.

AS_PATH comparison is broken if CONFED_AS_SEQ are present.
This patch fixes this issue

Signed-off-by: Daniel Walton <dwalton@cumulusnetworks.com>

bgpd/bgp_aspath.c

diff --git a/bgpd/bgp_aspath.c b/bgpd/bgp_aspath.c
index 3fd359c..e5541f6 100644
--- a/bgpd/bgp_aspath.c
+++ b/bgpd/bgp_aspath.c
@@ -427,7 +427,7 @@
 }
 
 unsigned int
-aspath_count_hops (struct aspath *aspath)
+aspath_count_hops (const struct aspath *aspath)
 {
   int count = 0;
   struct assegment *seg = aspath->segments;
@@ -1574,6 +1574,10 @@
   seg1 = aspath1->segments;
   seg2 = aspath2->segments;
 
+  /* If both paths are originated in this AS then we do want to compare MED */
+  if (!seg1 && !seg2)
+    return 1;
+
   /* find first non-confed segments for each */
   while (seg1 && ((seg1->type == AS_CONFED_SEQUENCE)
 		  || (seg1->type == AS_CONFED_SET)))

bgpd/bgp_aspath.h

diff --git a/bgpd/bgp_aspath.h b/bgpd/bgp_aspath.h
index aa13daa..c8f929f 100644
--- a/bgpd/bgp_aspath.h
+++ b/bgpd/bgp_aspath.h
@@ -103,7 +103,7 @@
 extern int aspath_confed_check (struct aspath *);
 extern int aspath_left_confed_check (struct aspath *);
 extern unsigned long aspath_count (void);
-extern unsigned int aspath_count_hops (struct aspath *);
+extern unsigned int aspath_count_hops (const struct aspath *);
 extern unsigned int aspath_count_confeds (struct aspath *);
 extern unsigned int aspath_size (struct aspath *);
 extern as_t aspath_highest (struct aspath *);