From: Ted Lemon <source@isc.org>
Date: Thu, 25 Jun 1998 21:20:41 +0000 (+0000)
Subject: If a client REQUESTs an abandoned lease, reclaim it.
X-Git-Tag: V2-BETA-1-PATCH-2~1
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=ea3f25096370bcc71a9723bd76f60b226ce769b7;p=thirdparty%2Fdhcp.git

If a client REQUESTs an abandoned lease, reclaim it.
---

diff --git a/server/dhcp.c b/server/dhcp.c
index 94c31c5fb..2f1573c0a 100644
--- a/server/dhcp.c
+++ b/server/dhcp.c
@@ -42,7 +42,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: dhcp.c,v 1.57.2.2 1998/06/25 21:11:35 mellon Exp $ Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: dhcp.c,v 1.57.2.3 1998/06/25 21:20:41 mellon Exp $ Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -1241,9 +1241,13 @@ struct lease *find_lease (packet, share, ours)
 		*ours = 1;
 
 	/* If the requested IP address isn't on the network the packet
-	   came from, or if it's been abandoned, don't use it. */
-	if (ip_lease && (ip_lease -> shared_network != share ||
-			 (ip_lease -> flags & ABANDONED_LEASE)))
+	   came from, don't use it.  Allow abandoned leases to be matched
+	   here - if the client is requesting it, there's a decent chance
+	   that it's because the lease database got trashed and a client
+	   that thought it had this lease answered an ARP or PING, causing the
+	   lease to be abandoned.   If so, this request probably came from
+	   that client. */
+	if (ip_lease && (ip_lease -> shared_network != share))
 		ip_lease = (struct lease *)0;
 
 	/* Toss ip_lease if it hasn't yet expired and the uid doesn't
@@ -1377,6 +1381,15 @@ struct lease *find_lease (packet, share, ours)
 		}
 	}
 
+	/* If we find an abandoned lease, take it, but print a
+	   warning message, so that if it continues to lose,
+	   the administrator will eventually investigate. */
+	if (lease -> flags & ABANDONED_LEASE) {
+		warn ("Reclaiming REQUESTed abandoned IP address %s.\n",
+		      piaddr (lease -> ip_addr));
+		lease -> flags &= ~ABANDONED_LEASE;
+	}
+
 	return lease;
 }