main/quagga: apply fix to rare bgpd crash during route selection

patch picked up from Cumulus Network's quagga patch queue

1 files changed, 37 insertions, 0 deletions

diff --git a/main/quagga/bgpd-gr-route-selection-fix.patch b/main/quagga/bgpd-gr-route-selection-fix.patch
new file mode 100644
index 0000000000..36719d3755
--- /dev/null
+++ b/main/quagga/bgpd-gr-route-selection-fix.patch
@@ -0,0 +1,37 @@
+During best path selection, if one of the candidates is a stale entry, do not
+perform the neighbor address comparison as that information is invalid for
+the stale entry. Attempting to perform the comparison results in a bgpd
+exception.
+
+diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
+index cca26d8..d30c643 100644
+--- a/bgpd/bgp_route.c
++++ b/bgpd/bgp_route.c
+@@ -540,7 +540,11 @@ bgp_info_cmp (struct bgp *bgp, struct bgp_info *new, struct bgp_info *exist,
+ 	return 0;
+     }
+ 
+-  /* 11. Rourter-ID comparision. */
++  /* 11. Router-ID comparision. */
++  /* If one of the paths is "stale", the corresponding peer router-id will
++   * be 0 and would always win over the other path. If originator id is
++   * used for the comparision, it will decide which path is better.
++   */
+   if (newattr->flag & ATTR_FLAG_BIT(BGP_ATTR_ORIGINATOR_ID))
+     new_id.s_addr = newattre->originator_id.s_addr;
+   else
+@@ -565,6 +569,14 @@ bgp_info_cmp (struct bgp *bgp, struct bgp_info *new, struct bgp_info *exist,
+     return 0;
+ 
+   /* 13. Neighbor address comparision. */
++  /* Do this only if neither path is "stale" as stale paths do not have
++   * valid peer information (as the connection may or may not be up).
++   */
++  if (CHECK_FLAG (exist->flags, BGP_INFO_STALE))
++    return 1;
++  if (CHECK_FLAG (new->flags, BGP_INFO_STALE))
++    return 0;
++
+   ret = sockunion_cmp (new->peer->su_remote, exist->peer->su_remote);
+ 
+   if (ret == 1)