[1555] Log warning if no interfaces are configured to listen DHCP traffic.

src/bin/dhcp4/ctrl_dhcp4_srv.cc

@@ -1,4 +1,4 @@
-// Copyright (C) 2012  Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2012-2013 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
@@ -284,7 +284,9 @@ ControlledDhcpv4Srv::openActiveSockets(const uint16_t port,
     }
     // Let's reopen active sockets. openSockets4 will check internally whether
     // sockets are marked active or inactive.
-    IfaceMgr::instance().openSockets4(port, use_bcast);
+    if (!IfaceMgr::instance().openSockets4(port, use_bcast)) {
+        LOG_WARN(dhcp4_logger, DHCP4_NO_SOCKETS_OPEN);
+    }
 }
 
 

src/bin/dhcp4/dhcp4_messages.mes

@@ -92,6 +92,11 @@ specified client after receiving a REQUEST message from it.  There are many
 possible reasons for such a failure. Additional messages will indicate the
 reason.
 
+% DHCP4_NO_SOCKETS_OPEN no interface configured to listen to DHCP traffic
+This warning message is issued when current server configuration specifies
+no interfaces that server should listen on, or specified interfaces are not
+configured to receive the traffic.
+
 % DHCP4_NOT_RUNNING IPv4 DHCP server is not running
 A warning message is issued when an attempt is made to shut down the
 IPv4 DHCP server but it is not running.

src/bin/dhcp6/ctrl_dhcp6_srv.cc

@@ -284,7 +284,9 @@ ControlledDhcpv6Srv::openActiveSockets(const uint16_t port) {
     }
     // Let's reopen active sockets. openSockets6 will check internally whether
     // sockets are marked active or inactive.
-    IfaceMgr::instance().openSockets6(port);
+    if (!IfaceMgr::instance().openSockets6(port)) {
+        LOG_WARN(dhcp6_logger, DHCP6_NO_SOCKETS_OPEN);
+    }
 }
 
 };

src/bin/dhcp6/dhcp6_messages.mes

@@ -111,6 +111,11 @@ IPv6 DHCP server but it is not running.
 During startup the IPv6 DHCP server failed to detect any network
 interfaces and is therefore shutting down.
 
+% DHCP6_NO_SOCKETS_OPEN no interface configured to listen to DHCP traffic
+This warning message is issued when current server configuration specifies
+no interfaces that server should listen on, or specified interfaces are not
+configured to receive the traffic.
+
 % DHCP6_OPEN_SOCKET opening sockets on port %1
 A debug message issued during startup, this indicates that the IPv6 DHCP
 server is about to open sockets on the specified port.