Add new rtnl_link_af_data_compare function to compare af_data

This patch adds a new api rtnl_linl_af_data_compare to
compare link af_data

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>

2 files changed, 35 insertions, 0 deletions

diff --git a/include/netlink/route/link/api.h b/include/netlink/route/link/api.h
index 92a48f7..28f2464 100644
--- a/include/netlink/route/link/api.h
+++ b/include/netlink/route/link/api.h
@@ -142,6 +142,9 @@ extern void *			rtnl_link_af_data(const struct rtnl_link *,
 						const struct rtnl_link_af_ops *);
 extern int			rtnl_link_af_register(struct rtnl_link_af_ops *);
 extern int			rtnl_link_af_unregister(struct rtnl_link_af_ops *);
+extern int			rtnl_link_af_data_compare(struct rtnl_link *a,
+							  struct rtnl_link *b,
+							  int family);
 
 #ifdef __cplusplus
 }
diff --git a/lib/route/link/api.c b/lib/route/link/api.c
index a12eb09..9387bc5 100644
--- a/lib/route/link/api.c
+++ b/lib/route/link/api.c
@@ -350,6 +350,38 @@ errout:
 	return err;
 }
 
+/**
+ * Compare af data for a link address family
+ * @arg a		Link object a
+ * @arg b		Link object b
+ * @arg family		af data family
+ *
+ * This function will compare af_data between two links
+ * a and b of family given by arg family
+ *
+ * @return 0 if address family specific data matches or is not present
+ * or != 0 if it mismatches.
+ */
+int rtnl_link_af_data_compare(struct rtnl_link *a, struct rtnl_link *b,
+			      int family)
+{
+	struct rtnl_link_af_ops *af_ops = rtnl_link_af_ops_lookup(family);
+
+	if (!af_ops)
+		return ~0;
+
+	if (!a->l_af_data[family] && !b->l_af_data[family])
+		return 0;
+
+	if (!a->l_af_data[family] || !b->l_af_data[family])
+		return ~0;
+
+	if (af_ops->ao_compare)
+		return af_ops->ao_compare(a, b, family, ~0, 0);
+
+	return 0;
+}
+
 /** @} */
 
 /** @} */