lib: Add equals function for nexthop groups

Add a function to check whether nexthop groups
are equivalent. It does not care about ordering.

Also, set any functions that it relies on to take
const vars as well.

Signed-off-by: Stephen Worley <sworley@cumulusnetworks.com>

1 files changed, 24 insertions, 1 deletions

diff --git a/lib/nexthop_group.c b/lib/nexthop_group.c
index 527039ac6..463ab0b88 100644
--- a/lib/nexthop_group.c
+++ b/lib/nexthop_group.c
@@ -94,7 +94,8 @@ uint8_t nexthop_group_active_nexthop_num(const struct nexthop_group *nhg)
 	return num;
 }
 
-struct nexthop *nexthop_exists(struct nexthop_group *nhg, struct nexthop *nh)
+struct nexthop *nexthop_exists(const struct nexthop_group *nhg,
+			       const struct nexthop *nh)
 {
 	struct nexthop *nexthop;
 
@@ -106,6 +107,28 @@ struct nexthop *nexthop_exists(struct nexthop_group *nhg, struct nexthop *nh)
 	return NULL;
 }
 
+bool nexthop_group_equal(const struct nexthop_group *nhg1,
+			 const struct nexthop_group *nhg2)
+{
+	struct nexthop *nh = NULL;
+
+	if (nhg1 && !nhg2)
+		return false;
+
+	if (!nhg1 && !nhg2)
+		return false;
+
+	if (nexthop_group_nexthop_num(nhg1) != nexthop_group_nexthop_num(nhg2))
+		return false;
+
+	for (ALL_NEXTHOPS_PTR(nhg1, nh)) {
+		if (!nexthop_exists(nhg2, nh))
+			return false;
+	}
+
+	return true;
+}
+
 struct nexthop_group *nexthop_group_new(void)
 {
 	return XCALLOC(MTYPE_NEXTHOP_GROUP, sizeof(struct nexthop_group));