From c6abd2055c5f7f99f8afa3a837ef6103adf66eb5 Mon Sep 17 00:00:00 2001
From: Ted Lemon <source@isc.org>
Date: Thu, 20 Nov 1997 04:19:21 +0000
Subject: [PATCH] Compute network number and (if not offered by server)
 broadcast address for linux client script

---
 client/dhclient.c | 42 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

diff --git a/client/dhclient.c b/client/dhclient.c
index 3e71acfa..92f8fdd5 100644
--- a/client/dhclient.c
+++ b/client/dhclient.c
@@ -56,7 +56,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: dhclient.c,v 1.42 1997/10/20 22:00:17 mellon Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: dhclient.c,v 1.43 1997/11/20 04:19:21 mellon Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -1829,6 +1829,46 @@ void script_write_params (ip, prefix, lease)
 	fprintf (scriptFile, "%sip_address=\"%s\"\n",
 		 prefix, piaddr (lease -> address));
 	fprintf (scriptFile, "export %sip_address\n", prefix);
+
+	/* For the benefit of Linux (and operating systems which may
+	   have similar needs), compute the network address based on
+	   the supplied ip address and netmask, if provided.  Also
+	   compute the broadcast address (the host address all ones
+	   broadcast address, not the host address all zeroes
+	   broadcast address). */
+
+	if (lease -> options [DHO_SUBNET_MASK].len &&
+	    (lease -> options [DHO_SUBNET_MASK].len <
+	     sizeof lease -> address.iabuf)) {
+		struct iaddr netmask, subnet, broadcast;
+
+		memcpy (netmask.iabuf,
+			lease -> options [DHO_SUBNET_MASK].data,
+			lease -> options [DHO_SUBNET_MASK].len);
+		netmask.len = lease -> options [DHO_SUBNET_MASK].len;
+
+		subnet = subnet_number (lease -> address, netmask);
+		if (subnet.len) {
+			fprintf (scriptFile, "%snetwork_number=\"%s\";\n",
+				 prefix, piaddr (subnet));
+			fprintf (scriptFile, "export %snetwork_number\n",
+				 prefix);
+
+			if (!lease -> options [DHO_BROADCAST_ADDRESS].len) {
+				broadcast = broadcast_addr (subnet, netmask);
+				if (broadcast.len) {
+					fprintf (scriptFile,
+						 "%s%s=\"%s\";\n", prefix,
+						 "broadcast_address",
+						 piaddr (broadcast));
+					fprintf (scriptFile,
+						 "export %s%s\n", prefix,
+						 "broadcast_address");
+				}
+			}
+		}
+	}
+
 	if (lease -> filename) {
 		fprintf (scriptFile, "%sfilename=\"%s\";\n",
 			 prefix, lease -> filename);