iproute2: add support to print 'linkdown' nexthop flag

Signed-off-by: Andy Gospodaerk <gospo@cumulusnetworks.com>
Signed-off-by: Dinesh Dutt <ddutt@cumulusnetworks.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
diff --git a/ip/iproute.c b/ip/iproute.c
index a882f12..41dea8f 100644
--- a/ip/iproute.c
+++ b/ip/iproute.c
@@ -451,6 +451,8 @@
 		fprintf(fp, "offload ");
 	if (r->rtm_flags & RTM_F_NOTIFY)
 		fprintf(fp, "notify ");
+	if (r->rtm_flags & RTNH_F_LINKDOWN)
+		fprintf(fp, "linkdown ");
 	if (tb[RTA_MARK]) {
 		unsigned int mark = *(unsigned int*)RTA_DATA(tb[RTA_MARK]);
 		if (mark) {
@@ -670,6 +672,8 @@
 				fprintf(fp, " onlink");
 			if (nh->rtnh_flags & RTNH_F_PERVASIVE)
 				fprintf(fp, " pervasive");
+			if (nh->rtnh_flags & RTNH_F_LINKDOWN)
+				fprintf(fp, " linkdown");
 			len -= NLMSG_ALIGN(nh->rtnh_len);
 			nh = RTNH_NEXT(nh);
 		}