$OpenBSD: patch-ifdata_c,v 1.4 2016/01/05 22:04:02 sthen Exp $
--- ifdata.c.orig	Mon Jul 13 18:29:11 2015
+++ ifdata.c	Tue Jan  5 15:33:51 2016
@@ -18,7 +18,7 @@
 	#include <net/if.h>
 #endif
 
-#if defined(__APPLE__)
+#if defined(__APPLE__) || defined(__OpenBSD__)
 	#define s6_addr16 __u6_addr.__u6_addr16
 	#include <net/if.h>
 #endif
@@ -242,7 +242,7 @@ struct sockaddr *if_network(const char *iface) {
 	return saddr;
 }
 
-int if_mtu(const char *iface) {
+int ifd_if_mtu(const char *iface) {
 	static struct ifreq req;
 
 	if (do_socket_ioctl(iface, SIOCGIFMTU, &req, NULL, PRINT_ERROR))
@@ -420,7 +420,7 @@ void please_do(int ndo, int *todo, const char *ifname)
 				print_addr(if_bcast(ifname, &req));
 				break;
 			case DO_PMTU:
-				printf("%d", if_mtu(ifname));
+				printf("%d", ifd_if_mtu(ifname));
 				break;
 			case DO_PNETWORK:
 				print_addr(if_network(ifname));
@@ -432,7 +432,7 @@ void please_do(int ndo, int *todo, const char *ifname)
 				printf(" ");
 				print_addr(if_bcast(ifname, &req));
 				printf(" ");
-				printf("%d", if_mtu(ifname));
+				printf("%d", ifd_if_mtu(ifname));
 				break;
 #if defined(__linux__)
 			case DO_SINPACKETS:
