$OpenBSD: patch-arp-scan_c,v 1.3 2021/09/08 21:49:05 sthen Exp $

Index: arp-scan.c
--- arp-scan.c.orig
+++ arp-scan.c
@@ -131,6 +131,10 @@ main(int argc, char *argv[]) {
  *      Process options.
  */
    process_options(argc, argv);
+   if (getuid() != 0) {
+      fprintf(stderr, "ERROR: arp-scan must be started with root privileges.\n");
+      exit(1);
+   }
 /*
  *      Get program start time for statistics displayed on completion.
  */
