From: Francis Dupont <fdupont@isc.org>
Date: Sat, 2 Mar 2019 19:22:07 +0000 (+0100)
Subject: [492-cb-subnet-merge-vs-duplicate-subnet-prefixes] Added comments about corner cases... 
X-Git-Tag: Kea-1.6.0-beta~71
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dede7fe07e86b71db0f45e308e7e9f8a344f8b63;p=thirdparty%2Fkea.git

[492-cb-subnet-merge-vs-duplicate-subnet-prefixes] Added comments about corner cases leading to problems
---

diff --git a/src/lib/dhcpsrv/cfg_subnets4.cc b/src/lib/dhcpsrv/cfg_subnets4.cc
index 1eb24fe70d..957a2c33e9 100644
--- a/src/lib/dhcpsrv/cfg_subnets4.cc
+++ b/src/lib/dhcpsrv/cfg_subnets4.cc
@@ -111,6 +111,10 @@ CfgSubnets4::merge(CfgOptionDefPtr cfg_def, CfgSharedNetworks4Ptr networks,
                 continue;
             }
 
+            // Updating the prefix can lead to problems... e.g. pools
+            // and reservations going outside range.
+            // @todo: check prefix change.
+
             // We're going to replace the existing subnet with the other
             // version. If it belongs to a shared network, we need
             // remove it from that network.
@@ -131,11 +135,9 @@ CfgSubnets4::merge(CfgOptionDefPtr cfg_def, CfgSharedNetworks4Ptr networks,
             // Subnet found.
             auto existing_subnet = *subnet_prefix_it;
 
-            // If the existing subnet and other subnet
-            // are the same instance skip it.
-            if (existing_subnet == *other_subnet) {
-                continue;
-            }
+            // Updating the id can lead to problems... e.g. reservation
+            // for the previous subnet ID.
+            // @todo: check reservations
 
             // We're going to replace the existing subnet with the other
             // version. If it belongs to a shared network, we need