lib,zebra: add api to enforce nexthop sort order when copying

Add an api that creates a copy of a list of nexthops and
enforces the canonical sort ordering; consolidate some nhg
code to avoid copy-and-paste. The zebra dplane uses
that api when a plugin sets up a list of nexthops, ensuring
that the plugin's list is ordered when it's processed in
zebra.

Signed-off-by: Mark Stapp <mjs@voltanet.io>

1 files changed, 7 insertions, 0 deletions

diff --git a/lib/nexthop_group.h b/lib/nexthop_group.h
index c90b21737a..73b020283a 100644
--- a/lib/nexthop_group.h
+++ b/lib/nexthop_group.h
@@ -44,6 +44,13 @@ void nexthop_group_delete(struct nexthop_group **nhg);
 
 void nexthop_group_copy(struct nexthop_group *to,
 			struct nexthop_group *from);
+
+/*
+ * Copy a list of nexthops in 'nh' to an nhg, enforcing canonical sort order
+ */
+void nexthop_group_copy_nh_sorted(struct nexthop_group *nhg,
+				  const struct nexthop *nh);
+
 void copy_nexthops(struct nexthop **tnh, const struct nexthop *nh,
 		   struct nexthop *rparent);