From: Marcin Siodelski <marcin@isc.org>
Date: Tue, 27 Jan 2015 17:37:11 +0000 (+0100)
Subject: [3692] Prevent infinite loops in allocation engine when pool exhausted.
X-Git-Tag: trac3712_base~27^2~3
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=77933170ef18f387783cb4691dd35f56fca95c77;p=thirdparty%2Fkea.git

[3692] Prevent infinite loops in allocation engine when pool exhausted.
---

diff --git a/src/lib/dhcpsrv/alloc_engine.cc b/src/lib/dhcpsrv/alloc_engine.cc
index 28677e98a8..ebc37256f8 100644
--- a/src/lib/dhcpsrv/alloc_engine.cc
+++ b/src/lib/dhcpsrv/alloc_engine.cc
@@ -1,4 +1,4 @@
-// Copyright (C) 2012-2014 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2012-2015 Internet Systems Consortium, Inc. ("ISC")
 //
 // Permission to use, copy, modify, and/or distribute this software for any
 // purpose with or without fee is hereby granted, provided that the above
@@ -674,6 +674,9 @@ AllocEngine::allocateLease4(const SubnetPtr& subnet, const ClientIdPtr& clientid
         /// moment, but we currently do not control expiration time at all
         unsigned int i = attempts_;
         do {
+            // Decrease the number of remaining attempts here so as we guarantee
+            // that it is decreased when the code below uses "continue".
+            --i;
             IOAddress candidate = allocator->pickAddress(subnet, clientid,
                                                          ctx.requested_address_);
 
@@ -710,7 +713,6 @@ AllocEngine::allocateLease4(const SubnetPtr& subnet, const ClientIdPtr& clientid
 
             // Continue trying allocation until we run out of attempts
             // (or attempts are set to 0, which means infinite)
-            --i;
         } while ((i > 0) || !attempts_);
 
         // Unable to allocate an address, return an empty lease.