Fix corner case where REBIND would be ignored rather than NAKed.

server/dhcp.c

@@ -22,7 +22,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: dhcp.c,v 1.140 2000/03/06 23:33:52 mellon Exp $ Copyright (c) 1995, 1996, 1997, 1998, 1999 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: dhcp.c,v 1.141 2000/03/07 02:50:45 mellon Exp $ Copyright (c) 1995, 1996, 1997, 1998, 1999 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -215,7 +215,10 @@ void dhcprequest (packet, ms_nulltp)
 	   If ciaddr was specified and Requested Address was not, then
 	   we really only know for sure what network a packet came from
 	   if it came through a BOOTP gateway - if it came through an
-	   IP router, we'll just have to assume that it's cool.
+	   IP router, we can't respond.   However, a client in REBINDING
+	   state with the wrong IP address will also look like this, and
+	   this is more likely, so we NAK these packets - if the packet
+	   came through a router, the NAK won't reach the client anyway.
 
 	   If we don't think we know where the packet came from, it
 	   came through a gateway from an unknown network, so it's not
@@ -251,6 +254,7 @@ void dhcprequest (packet, ms_nulltp)
 	if (!packet -> shared_network ||
 	    (packet -> raw -> ciaddr.s_addr &&
 	     packet -> raw -> giaddr.s_addr) ||
+	    (!oc && packet -> raw -> ciaddr.s_addr) ||
 	    (oc && !packet -> raw -> ciaddr.s_addr)) {
 		
 		/* If we don't know where it came from but we do know