--- a/src/network/core/core.cpp	Tue Jan 30 15:09:33 2007 +0000
+++ b/src/network/core/core.cpp	Tue Jan 30 17:12:46 2007 +0000
@@ -5,6 +5,8 @@
 #include "../../stdafx.h"
 #include "../../debug.h"
 #include "os_abstraction.h"
+#include "core.h"
+#include "packet.h"
 
 /**
  * @file core.cpp Functions used to initialize/shut down the core network
@@ -88,4 +90,33 @@
 #endif
 }
 
+
+/**
+ * Serializes the GRFIdentifier (GRF ID and MD5 checksum) to the packet
+ * @param p   the packet to write the data to
+ * @param grf the GRFIdentifier to serialize
+ */
+void NetworkSocketHandler::Send_GRFIdentifier(Packet *p, const GRFIdentifier *grf)
+{
+	uint j;
+	NetworkSend_uint32(p, grf->grfid);
+	for (j = 0; j < sizeof(grf->md5sum); j++) {
+		NetworkSend_uint8 (p, grf->md5sum[j]);
+	}
+}
+
+/**
+ * Deserializes the GRFIdentifier (GRF ID and MD5 checksum) from the packet
+ * @param p   the packet to read the data from
+ * @param grf the GRFIdentifier to deserialize
+ */
+void NetworkSocketHandler::Recv_GRFIdentifier(Packet *p, GRFIdentifier *grf)
+{
+	uint j;
+	grf->grfid = NetworkRecv_uint32(this, p);
+	for (j = 0; j < sizeof(grf->md5sum); j++) {
+		grf->md5sum[j] = NetworkRecv_uint8(this, p);
+	}
+}
+
 #endif /* ENABLE_NETWORK */

--- a/src/network/core/core.h	Tue Jan 30 15:09:33 2007 +0000
+++ b/src/network/core/core.h	Tue Jan 30 17:12:46 2007 +0000
@@ -6,6 +6,7 @@
 #ifdef ENABLE_NETWORK
 
 #include "os_abstraction.h"
+#include "../../newgrf_config.h"
 
 /**
  * @file core.h Base for all network types (UDP and TCP)
@@ -27,6 +28,9 @@
 	NETWORK_RECV_STATUS_CLOSE_QUERY,      ///< Done quering the server
 } NetworkRecvStatus;
 
+/** Forward declaration due to circular dependencies */
+class Packet;
+
 /**
  * SocketHandler for all network sockets in OpenTTD.
  */
@@ -66,6 +70,9 @@
 	 * @return true when the current client has quit, false otherwise
 	 */
 	bool HasClientQuit() { return this->has_quit; }
+
+	void Send_GRFIdentifier(Packet *p, const GRFIdentifier *grf);
+	void Recv_GRFIdentifier(Packet *p, GRFIdentifier *grf);
 };
 
 #endif /* ENABLE_NETWORK */

--- a/src/network/core/udp.cpp	Tue Jan 30 15:09:33 2007 +0000
+++ b/src/network/core/udp.cpp	Tue Jan 30 17:12:46 2007 +0000
@@ -144,35 +144,6 @@
 
 
 /**
- * Serializes the GRFIdentifier (GRF ID and MD5 checksum) to the packet
- * @param p   the packet to write the data to
- * @param grf the GRFIdentifier to serialize
- */
-void NetworkUDPSocketHandler::Send_GRFIdentifier(Packet *p, const GRFIdentifier *grf)
-{
-	uint j;
-	NetworkSend_uint32(p, grf->grfid);
-	for (j = 0; j < sizeof(grf->md5sum); j++) {
-		NetworkSend_uint8 (p, grf->md5sum[j]);
-	}
-}
-
-/**
- * Deserializes the GRFIdentifier (GRF ID and MD5 checksum) from the packet
- * @param p   the packet to read the data from
- * @param grf the GRFIdentifier to deserialize
- */
-void NetworkUDPSocketHandler::Recv_GRFIdentifier(Packet *p, GRFIdentifier *grf)
-{
-	uint j;
-	grf->grfid = NetworkRecv_uint32(this, p);
-	for (j = 0; j < sizeof(grf->md5sum); j++) {
-		grf->md5sum[j] = NetworkRecv_uint8(this, p);
-	}
-}
-
-
-/**
  * Serializes the NetworkGameInfo struct to the packet
  * @param p    the packet to write the data to
  * @param info the NetworkGameInfo struct to serialize

--- a/src/network/core/udp.h	Tue Jan 30 15:09:33 2007 +0000
+++ b/src/network/core/udp.h	Tue Jan 30 17:12:46 2007 +0000
@@ -9,7 +9,6 @@
 #include "core.h"
 #include "game.h"
 #include "packet.h"
-#include "../../newgrf_config.h"
 #include "../../debug.h"
 
 /**
@@ -131,10 +130,7 @@
 	void SendPacket(Packet *p, const struct sockaddr_in *recv);
 	void ReceivePackets();
 
-	void Send_GRFIdentifier(Packet *p, const GRFIdentifier *grf);
 	void Send_NetworkGameInfo(Packet *p, const NetworkGameInfo *info);
-
-	void Recv_GRFIdentifier(Packet *p, GRFIdentifier *grf);
 	void Recv_NetworkGameInfo(Packet *p, NetworkGameInfo *info);
 };