Add support for IPv6

Two new configuration options are added:
     - "enable_ipv6" to enable/disable the overall use of IPv6
     - "ipv6_server" to enable/disable the use of IPv6 sockets when running
       a server (when "enable_ipv6" is enabled)

minetest.conf.example

@@ -367,3 +367,9 @@
 
 # Float islands starts from height, 0 to disable
 #mgindev_float_islands = 500
+
+# Enable/disable IPv6
+#enable_ipv6 = true
+# Enable/disable running an IPv6 server.  An IPv6 server may be restricted
+# to IPv6 clients, depending on system configuration.
+#ipv6_server = false

src/client.cpp

@@ -271,7 +271,8 @@ Client::Client(
 		IWritableItemDefManager *itemdef,
 		IWritableNodeDefManager *nodedef,
 		ISoundManager *sound,
-		MtEventManager *event
+		MtEventManager *event,
+		bool ipv6
 ):
 	m_tsrc(tsrc),
 	m_shsrc(shsrc),
@@ -287,7 +288,7 @@ Client::Client(
 		device->getSceneManager(),
 		tsrc, this, device
 	),
-	m_con(PROTOCOL_ID, 512, CONNECTION_TIMEOUT, this),
+	m_con(PROTOCOL_ID, 512, CONNECTION_TIMEOUT, ipv6, this),
 	m_device(device),
 	m_server_ser_ver(SER_FMT_VER_INVALID),
 	m_playeritem(0),

src/client.h

@@ -263,7 +263,8 @@ class Client : public con::PeerHandler, public InventoryManager, public IGameDef
 			IWritableItemDefManager *itemdef,
 			IWritableNodeDefManager *nodedef,
 			ISoundManager *sound,
-			MtEventManager *event
+			MtEventManager *event,
+			bool ipv6
 	);
 
 	~Client();

src/connection.cpp

@@ -520,10 +520,12 @@ void Peer::reportRTT(float rtt)
 	Connection
 */
 
-Connection::Connection(u32 protocol_id, u32 max_packet_size, float timeout):
+Connection::Connection(u32 protocol_id, u32 max_packet_size, float timeout,
+		bool ipv6):
 	m_protocol_id(protocol_id),
 	m_max_packet_size(max_packet_size),
 	m_timeout(timeout),
+	m_socket(ipv6),
 	m_peer_id(0),
 	m_bc_peerhandler(NULL),
 	m_bc_receive_timeout(0),
@@ -535,10 +537,11 @@ Connection::Connection(u32 protocol_id, u32 max_packet_size, float timeout):
 }
 
 Connection::Connection(u32 protocol_id, u32 max_packet_size, float timeout,
-		PeerHandler *peerhandler):
+		bool ipv6, PeerHandler *peerhandler):
 	m_protocol_id(protocol_id),
 	m_max_packet_size(max_packet_size),
 	m_timeout(timeout),
+	m_socket(ipv6),
 	m_peer_id(0),
 	m_bc_peerhandler(peerhandler),
 	m_bc_receive_timeout(0),

src/connection.h

@@ -548,8 +548,8 @@ struct ConnectionCommand
 class Connection: public SimpleThread
 {
 public:
-	Connection(u32 protocol_id, u32 max_packet_size, float timeout);
-	Connection(u32 protocol_id, u32 max_packet_size, float timeout,
+	Connection(u32 protocol_id, u32 max_packet_size, float timeout, bool ipv6);
+	Connection(u32 protocol_id, u32 max_packet_size, float timeout, bool ipv6,
 			PeerHandler *peerhandler);
 	~Connection();
 	void * Thread();

src/constants.h

@@ -36,6 +36,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 // Causes the socket class to deliberately drop random packets.
 // This disables unit testing of socket and connection.
 #define INTERNET_SIMULATOR 0
+#define INTERNET_SIMULATOR_PACKET_LOSS 10 // 10 = easy, 4 = hard
 
 #define CONNECTION_TIMEOUT 30
 

src/debug.h

@@ -34,7 +34,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #ifdef _WIN32
 	#define WIN32_LEAN_AND_MEAN
 	#ifndef _WIN32_WINNT
-		#define _WIN32_WINNT 0x0500
+		#define _WIN32_WINNT 0x0501
 	#endif
 	#include <windows.h>
 	#ifdef _MSC_VER

src/defaultsettings.cpp

@@ -251,6 +251,10 @@ void set_default_settings(Settings *settings)
 	settings->setDefault("mgindev_np_float_islands3", "0,    1,   (256, 256, 256), 6412,  2, 0.5,  1,   0.5");
 	settings->setDefault("mgindev_np_biome",          "0,    1,   (250, 250, 250), 9130,  3, 0.50, 1,   10");
 	settings->setDefault("mgindev_float_islands", "500");
+
+	// IPv6
+	settings->setDefault("enable_ipv6", "true");
+	settings->setDefault("ipv6_server", "false");
 }
 
 void override_default_settings(Settings *settings, Settings *from)

src/game.cpp

@@ -1039,12 +1039,6 @@ void the_game(
 	infostream<<"Creating client"<<std::endl;
 
 	MapDrawControl draw_control;
-
-	Client client(device, playername.c_str(), password, draw_control,
-			tsrc, shsrc, itemdef, nodedef, sound, &eventmgr);
-
-	// Client acts as our GameDef
-	IGameDef *gamedef = &client;
 
 	{
 		wchar_t* text = wgettext("Resolving address...");
@@ -1054,18 +1048,39 @@ void the_game(
 	Address connect_address(0,0,0,0, port);
 	try{
 		if(address == "")
+		{
 			//connect_address.Resolve("localhost");
-			connect_address.setAddress(127,0,0,1);
+			if(g_settings->getBool("enable_ipv6") && g_settings->getBool("ipv6_server"))
+			{
+				IPv6AddressBytes addr_bytes;
+				addr_bytes.bytes[15] = 1;
+				connect_address.setAddress(&addr_bytes);
+			}
+			else
+			{
+				connect_address.setAddress(127,0,0,1);
+			}
+		}
 		else
 			connect_address.Resolve(address.c_str());
 	}
 	catch(ResolveError &e)
 	{
-		error_message = L"Couldn't resolve address";
+		error_message = L"Couldn't resolve address: " + narrow_to_wide(e.what());
 		errorstream<<wide_to_narrow(error_message)<<std::endl;
 		// Break out of client scope
 		break;
 	}
+
+	/*
+		Create client
+	*/
+	Client client(device, playername.c_str(), password, draw_control,
+		tsrc, shsrc, itemdef, nodedef, sound, &eventmgr,
+		connect_address.isIPv6());
+
+	// Client acts as our GameDef
+	IGameDef *gamedef = &client;
 
 	/*
 		Attempt to connect to the server

src/gettext.h

@@ -14,6 +14,9 @@
 
 #if defined(_WIN32)
 #define WIN32_LEAN_AND_MEAN
+#ifndef _WIN32_WINNT
+	#define _WIN32_WINNT 0x0501
+#endif
 #include <windows.h>
 #endif
 

src/jthread/jmutex.h

@@ -31,7 +31,7 @@
 
 #if (defined(WIN32) || defined(_WIN32_WCE))
 	#ifndef _WIN32_WINNT
-		#define _WIN32_WINNT 0x0500
+		#define _WIN32_WINNT 0x0501
 	#endif
 	#ifndef _WIN32_WCE
 		#include <process.h>

src/porting.h

@@ -42,7 +42,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #ifdef _WIN32
 	#ifndef _WIN32_WINNT
-		#define _WIN32_WINNT 0x0500
+		#define _WIN32_WINNT 0x0501
 	#endif
 	#include <windows.h>
 
@@ -153,6 +153,9 @@ bool threadSetPriority(threadid_t tid, int prio);
 	Overflow can occur at any value higher than 10000000.
 */
 #ifdef _WIN32 // Windows
+#ifndef _WIN32_WINNT
+	#define _WIN32_WINNT 0x0501
+#endif
 	#include <windows.h>
 
 	inline u32 getTimeS()

src/server.cpp

@@ -639,7 +639,8 @@ Server::Server(
 	m_simple_singleplayer_mode(simple_singleplayer_mode),
 	m_async_fatal_error(""),
 	m_env(NULL),
-	m_con(PROTOCOL_ID, 512, CONNECTION_TIMEOUT, this),
+	m_con(PROTOCOL_ID, 512, CONNECTION_TIMEOUT,
+	      g_settings->getBool("enable_ipv6") && g_settings->getBool("ipv6_server"), this),
 	m_banmanager(path_world+DIR_DELIM+"ipban.txt"),
 	m_rollback(NULL),
 	m_rollback_sink_enabled(true),