--- relay/dhcrelay.c-orig	Sat Apr 27 05:34:20 2002
+++ relay/dhcrelay.c	Wed Feb 19 12:44:19 2003
@@ -88,6 +88,7 @@
 				   did not match any known circuit ID. */
 int missing_circuit_id = 0;	/* Circuit ID option in matching RAI option
 				   was missing. */
+int max_hop_count = 4;	/* Maximum hop count */
 
 	/* Maximum size of a packet with agent options added. */
 int dhcp_max_agent_option_packet_length = 576;
@@ -182,6 +183,15 @@
 			quiet_interface_discovery = 1;
 		} else if (!strcmp (argv [i], "-a")) {
 			add_agent_options = 1;
+		} else if (!strcmp (argv [i], "-c")) {
+			int	hcount;	
+			if (++i == argc)
+				usage ();
+			hcount = atoi(argv[i]);	
+			if (hcount <= 16)
+				max_hop_count = hcount;
+			else
+				usage ();
 		} else if (!strcmp (argv [i], "-A")) {
 			if (++i == argc)
 				usage ();
@@ -425,6 +435,17 @@
 		packet -> giaddr = ip -> primary_address;
 	if (packet -> hops != 255)
 		packet -> hops = packet -> hops + 1;
+
+   /*  ftp://ftp.rfc-editor.org/in-notes/rfc1542.txt
+    *  4.1.1 BOOTREQUEST Messages
+    *  The relay agent MUST silently discard BOOTREQUEST messages whose
+    *  'hops' field exceeds the value 16.  A configuration option SHOULD be
+    *  provided to set this threshold to a smaller value if desired by the
+    *  network manager.  The default setting for a configurable threshold
+    *  SHOULD be 4.
+    */
+	if (packet -> hops >= max_hop_count)
+		return;
 
 	/* Otherwise, it's a BOOTREQUEST, so forward it to all the
 	   servers. */
@@ -470,7 +470,7 @@
 static void usage ()
 {
 	log_fatal ("Usage: dhcrelay [-p <port>] [-d] [-D] [-i %s%s%s",
-	       "interface]\n                ",
+	       "interface] [-c max_hop_count]\n                ",
 	       "[-q] [-a] [-A length] [-m append|replace|forward|discard]\n",
 	       "                [server1 [... serverN]]");
 }