12 files changed, 1249 insertions, 164 deletions

diff --git a/Source/Core/Common/Common.vcxproj b/Source/Core/Common/Common.vcxproj
index dfe91db48b..fdd3183587 100644
--- a/Source/Core/Common/Common.vcxproj
+++ b/Source/Core/Common/Common.vcxproj
@@ -80,6 +80,8 @@
     <ClInclude Include="SysConf.h" />
     <ClInclude Include="Thread.h" />
     <ClInclude Include="Timer.h" />
+    <ClInclude Include="TraversalClient.h" />
+    <ClInclude Include="TraversalProto.h" />
     <ClInclude Include="x64ABI.h" />
     <ClInclude Include="x64Analyzer.h" />
     <ClInclude Include="x64Emitter.h" />
@@ -116,6 +118,7 @@
     <ClCompile Include="SysConf.cpp" />
     <ClCompile Include="Thread.cpp" />
     <ClCompile Include="Timer.cpp" />
+    <ClCompile Include="TraversalClient.cpp" />
     <ClCompile Include="Version.cpp" />
     <ClCompile Include="x64ABI.cpp" />
     <ClCompile Include="x64Analyzer.cpp" />
@@ -142,4 +145,4 @@
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
+</Project>
\ No newline at end of file
diff --git a/Source/Core/Common/Common.vcxproj.filters b/Source/Core/Common/Common.vcxproj.filters
index 2f121ca882..da11bd379b 100644
--- a/Source/Core/Common/Common.vcxproj.filters
+++ b/Source/Core/Common/Common.vcxproj.filters
@@ -71,6 +71,9 @@
     </ClInclude>
     <ClInclude Include="GekkoDisassembler.h" />
     <ClInclude Include="Event.h" />
+    <ClInclude Include="JitRegister.h" />
+    <ClInclude Include="TraversalClient.h" />
+    <ClInclude Include="TraversalProto.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="BreakPoints.cpp" />
@@ -117,8 +120,10 @@
     </ClCompile>
     <ClCompile Include="XSaveWorkaround.cpp" />
     <ClCompile Include="GekkoDisassembler.cpp" />
+    <ClCompile Include="JitRegister.cpp" />
+    <ClCompile Include="TraversalClient.cpp" />
   </ItemGroup>
   <ItemGroup>
     <Text Include="CMakeLists.txt" />
   </ItemGroup>
-</Project>
+</Project>
\ No newline at end of file
diff --git a/Source/Core/Common/TraversalClient.cpp b/Source/Core/Common/TraversalClient.cpp
new file mode 100644
index 0000000000..9ac5eca238
--- /dev/null
+++ b/Source/Core/Common/TraversalClient.cpp
@@ -0,0 +1,370 @@
+// This file is public domain, in case it's useful to anyone. -comex
+
+#include "Common/TraversalClient.h"
+#include "enet/enet.h"
+#include "Timer.h"
+
+static void GetRandomishBytes(u8* buf, size_t size)
+{
+	// We don't need high quality random numbers (which might not be available),
+	// just non-repeating numbers!
+	srand(enet_time_get());
+	for (size_t i = 0; i < size; i++)
+		buf[i] = rand() & 0xff;
+}
+
+TraversalClient::TraversalClient(ENetHost* netHost, const std::string& server)
+	: m_NetHost(netHost)
+	, m_Server(server)
+	, m_Client(nullptr)
+	, m_FailureReason(0)
+	, m_ConnectRequestId(0)
+	, m_PendingConnect(false)
+	, m_PingTime(0)
+{
+	netHost->intercept = TraversalClient::InterceptCallback;
+
+	Reset();
+
+	ReconnectToServer();
+}
+
+TraversalClient::~TraversalClient()
+{
+}
+
+void TraversalClient::ReconnectToServer()
+{
+	m_Server = "vps.qoid.us"; // XXX
+	if (enet_address_set_host(&m_ServerAddress, m_Server.c_str()))
+	{
+		OnFailure(BadHost);
+		return;
+	}
+	m_ServerAddress.port = 6262;
+
+	m_State = Connecting;
+
+	TraversalPacket hello = {};
+	hello.type = TraversalPacketHelloFromClient;
+	hello.helloFromClient.protoVersion = TraversalProtoVersion;
+	SendTraversalPacket(hello);
+	if (m_Client)
+		m_Client->OnTraversalStateChanged();
+}
+
+static ENetAddress MakeENetAddress(TraversalInetAddress* address)
+{
+	ENetAddress eaddr;
+	if (address->isIPV6)
+	{
+		eaddr.port = 0; // no support yet :(
+	}
+	else
+	{
+		eaddr.host = address->address[0];
+		eaddr.port = ntohs(address->port);
+	}
+	return eaddr;
+}
+
+void TraversalClient::ConnectToClient(const std::string& host)
+{
+	if (host.size() > sizeof(TraversalHostId))
+	{
+		PanicAlert("host too long");
+		return;
+	}
+	TraversalPacket packet = {};
+	packet.type = TraversalPacketConnectPlease;
+	memcpy(packet.connectPlease.hostId.data(), host.c_str(), host.size());
+	m_ConnectRequestId = SendTraversalPacket(packet);
+	m_PendingConnect = true;
+}
+
+bool TraversalClient::TestPacket(u8* data, size_t size, ENetAddress* from)
+{
+	if (from->host == m_ServerAddress.host &&
+	    from->port == m_ServerAddress.port)
+	{
+		if (size < sizeof(TraversalPacket))
+		{
+			ERROR_LOG(NETPLAY, "Received too-short traversal packet.");
+		}
+		else
+		{
+			HandleServerPacket((TraversalPacket*) data);
+			return true;
+		}
+	}
+	return false;
+}
+
+//--Temporary until more of the old netplay branch is moved over
+void TraversalClient::Update()
+{
+	ENetEvent netEvent;
+	if (enet_host_service(m_NetHost, &netEvent, 4) > 0)
+	{
+		switch (netEvent.type)
+		{
+		case ENET_EVENT_TYPE_RECEIVE:
+			TestPacket(netEvent.packet->data, netEvent.packet->dataLength, &netEvent.peer->address);
+
+			enet_packet_destroy(netEvent.packet);
+			break;
+		}
+	}
+	HandleResends();
+}
+
+void TraversalClient::HandleServerPacket(TraversalPacket* packet)
+{
+	u8 ok = 1;
+	switch (packet->type)
+	{
+	case TraversalPacketAck:
+		if (!packet->ack.ok)
+		{
+			OnFailure(ServerForgotAboutUs);
+			break;
+		}
+		for (auto it = m_OutgoingTraversalPackets.begin(); it != m_OutgoingTraversalPackets.end(); ++it)
+		{
+			if (it->packet.requestId == packet->requestId)
+			{
+				m_OutgoingTraversalPackets.erase(it);
+				break;
+			}
+		}
+		break;
+	case TraversalPacketHelloFromServer:
+		if (m_State != Connecting)
+			break;
+		if (!packet->helloFromServer.ok)
+		{
+			OnFailure(VersionTooOld);
+			break;
+		}
+		m_HostId = packet->helloFromServer.yourHostId;
+		m_State = Connected;
+		if (m_Client)
+			m_Client->OnTraversalStateChanged();
+		break;
+	case TraversalPacketPleaseSendPacket:
+		{
+		// security is overrated.
+		ENetAddress addr = MakeENetAddress(&packet->pleaseSendPacket.address);
+		if (addr.port != 0)
+		{
+			char message[] = "Hello from Dolphin Netplay...";
+			ENetBuffer buf;
+			buf.data = message;
+			buf.dataLength = sizeof(message) - 1;
+			enet_socket_send(m_NetHost->socket, &addr, &buf, 1);
+		}
+		else
+		{
+			// invalid IPV6
+			ok = 0;
+		}
+		break;
+		}
+	case TraversalPacketConnectReady:
+	case TraversalPacketConnectFailed:
+		{
+		if (!m_PendingConnect || packet->connectReady.requestId != m_ConnectRequestId)
+			break;
+
+		m_PendingConnect = false;
+
+		if (!m_Client)
+			break;
+
+		if (packet->type == TraversalPacketConnectReady)
+			m_Client->OnConnectReady(MakeENetAddress(&packet->connectReady.address));
+		else
+			m_Client->OnConnectFailed(packet->connectFailed.reason);
+		break;
+		}
+	default:
+		WARN_LOG(NETPLAY, "Received unknown packet with type %d", packet->type);
+		break;
+	}
+	if (packet->type != TraversalPacketAck)
+	{
+		TraversalPacket ack = {};
+		ack.type = TraversalPacketAck;
+		ack.requestId = packet->requestId;
+		ack.ack.ok = ok;
+
+		ENetBuffer buf;
+		buf.data = &ack;
+		buf.dataLength = sizeof(ack);
+		if (enet_socket_send(m_NetHost->socket, &m_ServerAddress, &buf, 1) == -1)
+			OnFailure(SocketSendError);
+	}
+}
+
+void TraversalClient::OnFailure(int reason)
+{
+	m_State = Failure;
+	m_FailureReason = reason;
+
+	switch (reason)
+	{
+	case TraversalClient::BadHost:
+	{
+		auto server = "dolphin-emu.org";
+		PanicAlertT("Couldn't look up central server %s", server);
+		break;
+	}
+	case TraversalClient::VersionTooOld:
+		PanicAlertT("Dolphin too old for traversal server");
+		break;
+	case TraversalClient::ServerForgotAboutUs:
+		PanicAlertT("Disconnected from traversal server");
+		break;
+	case TraversalClient::SocketSendError:
+		PanicAlertT("Socket error sending to traversal server");
+		break;
+	case TraversalClient::ResendTimeout:
+		PanicAlertT("Timeout connecting to traversal server");
+		break;
+	default:
+		PanicAlertT("Unknown error %x", reason);
+		break;
+	}
+
+	if (m_Client)
+		m_Client->OnTraversalStateChanged();
+}
+
+void TraversalClient::ResendPacket(OutgoingTraversalPacketInfo* info)
+{
+	info->sendTime = enet_time_get();
+	info->tries++;
+	ENetBuffer buf;
+	buf.data = &info->packet;
+	buf.dataLength = sizeof(info->packet);
+	if (enet_socket_send(m_NetHost->socket, &m_ServerAddress, &buf, 1) == -1)
+		OnFailure(SocketSendError);
+}
+
+void TraversalClient::HandleResends()
+{
+	enet_uint32 now = enet_time_get();
+	for (auto& tpi : m_OutgoingTraversalPackets)
+	{
+		if (now - tpi.sendTime >= (u32) (300 * tpi.tries))
+		{
+			if (tpi.tries >= 5)
+			{
+				OnFailure(ResendTimeout);
+				m_OutgoingTraversalPackets.clear();
+				break;
+			}
+			else
+			{
+				ResendPacket(&tpi);
+			}
+		}
+	}
+	HandlePing();
+}
+
+void TraversalClient::HandlePing()
+{
+	enet_uint32 now = enet_time_get();
+	if (m_State == Connected && now - m_PingTime >= 500)
+	{
+		TraversalPacket ping = {0};
+		ping.type = TraversalPacketPing;
+		ping.ping.hostId = m_HostId;
+		SendTraversalPacket(ping);
+		m_PingTime = now;
+	}
+}
+
+TraversalRequestId TraversalClient::SendTraversalPacket(const TraversalPacket& packet)
+{
+	OutgoingTraversalPacketInfo info;
+	info.packet = packet;
+	GetRandomishBytes((u8*) &info.packet.requestId, sizeof(info.packet.requestId));
+	info.tries = 0;
+	m_OutgoingTraversalPackets.push_back(info);
+	ResendPacket(&m_OutgoingTraversalPackets.back());
+	return info.packet.requestId;
+}
+
+void TraversalClient::Reset()
+{
+	m_PendingConnect = false;
+	m_Client = nullptr;
+}
+
+int ENET_CALLBACK TraversalClient::InterceptCallback(ENetHost* host, ENetEvent* event)
+{
+	auto traversalClient = g_TraversalClient.get();
+	if (traversalClient->TestPacket(host->receivedData, host->receivedDataLength, &host->receivedAddress))
+	{
+		event->type = (ENetEventType)42;
+		return 1;
+	}
+	return 0;
+}
+
+std::unique_ptr<TraversalClient> g_TraversalClient;
+std::unique_ptr<ENetHost> g_MainNetHost;
+
+// The settings at the previous TraversalClient reset - notably, we
+// need to know not just what port it's on, but whether it was
+// explicitly requested.
+static std::string g_OldServer;
+static u16 g_OldPort;
+
+bool EnsureTraversalClient(const std::string& server, u16 port)
+{
+	if (!g_MainNetHost || !g_TraversalClient || server != g_OldServer || port != g_OldPort)
+	{
+		g_OldServer = server;
+		g_OldPort = port;
+
+		ENetAddress addr = { ENET_HOST_ANY, port };
+		ENetHost* host = enet_host_create(
+			&addr, // address
+			50, // peerCount
+			1, // channelLimit
+			0, // incomingBandwidth
+			0); // outgoingBandwidth
+		if (!host)
+		{
+			g_MainNetHost.reset();
+			return false;
+		}
+		g_MainNetHost.reset(host);
+		
+		g_TraversalClient.reset(new TraversalClient(g_MainNetHost.get(), server));
+
+	}
+	return true;
+}
+
+void ReleaseTraversalClient()
+{
+	if (!g_TraversalClient)
+		return;
+
+	if (g_OldPort != 0)
+	{
+		// If we were listening at a specific port, kill the
+		// TraversalClient to avoid hanging on to the port.
+		g_TraversalClient.reset();
+		g_MainNetHost.reset();
+	}
+	else
+	{
+		// Reset any pending connection attempts.
+		g_TraversalClient->Reset();
+	}
+}
diff --git a/Source/Core/Common/TraversalClient.h b/Source/Core/Common/TraversalClient.h
new file mode 100644
index 0000000000..838ea6448a
--- /dev/null
+++ b/Source/Core/Common/TraversalClient.h
@@ -0,0 +1,88 @@
+// This file is public domain, in case it's useful to anyone. -comex
+
+#pragma once
+#include <functional>
+#include <list>
+#include <memory>
+#include "Common/Common.h"
+#include "Common/Thread.h"
+#include "Common/TraversalProto.h"
+
+#include "enet/enet.h"
+
+class TraversalClientClient
+{
+public:
+	virtual ~TraversalClientClient(){};
+	virtual void OnTraversalStateChanged()=0;
+	virtual void OnConnectReady(ENetAddress addr)=0;
+	virtual void OnConnectFailed(u8 reason)=0;
+};
+
+class TraversalClient
+{
+public:
+	enum State
+	{
+		Connecting,
+		Connected,
+		Failure
+	};
+
+	enum FailureReason
+	{
+		BadHost = 0x300,
+		VersionTooOld,
+		ServerForgotAboutUs,
+		SocketSendError,
+		ResendTimeout,
+		ConnectFailedError = 0x400,
+	};
+
+	TraversalClient(ENetHost* netHost, const std::string& server);
+	~TraversalClient();
+	void Reset();
+	void ConnectToClient(const std::string& host);
+	void ReconnectToServer();
+	void Update();
+
+	// called from NetHost
+	bool TestPacket(u8* data, size_t size, ENetAddress* from);
+	void HandleResends();
+
+	ENetHost* m_NetHost;
+	TraversalClientClient* m_Client;
+	TraversalHostId m_HostId;
+	State m_State;
+	int m_FailureReason;
+
+private:
+	struct OutgoingTraversalPacketInfo
+	{
+		TraversalPacket packet;
+		int tries;
+		enet_uint32 sendTime;
+	};
+	
+	void HandleServerPacket(TraversalPacket* packet);
+	void ResendPacket(OutgoingTraversalPacketInfo* info);
+	TraversalRequestId SendTraversalPacket(const TraversalPacket& packet);
+	void OnFailure(int reason);
+	void HandlePing();
+	static int ENET_CALLBACK InterceptCallback(ENetHost* host, ENetEvent* event);
+
+	TraversalRequestId m_ConnectRequestId;
+	bool m_PendingConnect;
+	std::list<OutgoingTraversalPacketInfo> m_OutgoingTraversalPackets;
+	ENetAddress m_ServerAddress;
+	std::string m_Server;
+	enet_uint32 m_PingTime;
+};
+
+extern std::unique_ptr<TraversalClient> g_TraversalClient;
+// the NetHost connected to the TraversalClient.
+extern std::unique_ptr<ENetHost> g_MainNetHost;
+
+// Create g_TraversalClient and g_MainNetHost if necessary.
+bool EnsureTraversalClient(const std::string& server, u16 port);
+void ReleaseTraversalClient();
diff --git a/Source/Core/Common/TraversalProto.h b/Source/Core/Common/TraversalProto.h
new file mode 100644
index 0000000000..32891beac6
--- /dev/null
+++ b/Source/Core/Common/TraversalProto.h
@@ -0,0 +1,96 @@
+// This file is public domain, in case it's useful to anyone. -comex
+
+#pragma once
+#include <array>
+#include "Common/CommonTypes.h"
+
+
+typedef std::array<char, 8> TraversalHostId;
+typedef u64 TraversalRequestId;
+
+enum TraversalPacketType
+{
+	// [*->*]
+	TraversalPacketAck = 0,
+	// [c->s]
+	TraversalPacketPing = 1,
+	// [c->s]
+	TraversalPacketHelloFromClient = 2,
+	// [s->c]
+	TraversalPacketHelloFromServer = 3,
+	// [c->s] When connecting, first the client asks the central server...
+	TraversalPacketConnectPlease = 4,
+	// [s->c] ...who asks the game host to send a UDP packet to the
+	// client... (an ack implies success)
+	TraversalPacketPleaseSendPacket = 5,
+	// [s->c] ...which the central server relays back to the client.
+	TraversalPacketConnectReady = 6,
+	// [s->c] Alternately, the server might not have heard of this host.
+	TraversalPacketConnectFailed = 7
+};
+
+enum
+{
+	TraversalProtoVersion = 0
+};
+
+enum TraversalConnectFailedReason
+{
+	TraversalConnectFailedClientDidntRespond = 0,
+	TraversalConnectFailedClientFailure,
+	TraversalConnectFailedNoSuchClient
+};
+
+#pragma pack(push, 1)
+struct TraversalInetAddress
+{
+	u8 isIPV6;
+	u32 address[4];
+	u16 port;
+};
+struct TraversalPacket
+{
+	u8 type;
+	TraversalRequestId requestId;
+	union
+	{
+		struct
+		{
+			u8 ok;
+		} ack;
+		struct
+		{
+			TraversalHostId hostId;
+		} ping;
+		struct
+		{
+			u8 protoVersion;
+		} helloFromClient;
+		struct
+		{
+			u8 ok;
+			TraversalHostId yourHostId;
+			TraversalInetAddress yourAddress; // currently unused
+		} helloFromServer;
+		struct
+		{
+			TraversalHostId hostId;
+		} connectPlease;
+		struct
+		{
+			TraversalInetAddress address;
+		} pleaseSendPacket;
+		struct
+		{
+			TraversalRequestId requestId;
+			TraversalInetAddress address;
+		} connectReady;
+		struct
+		{
+			TraversalRequestId requestId;
+			u8 reason;
+		} connectFailed;
+	};
+};
+#pragma pack(pop)
+
diff --git a/Source/Core/Core/NetPlayClient.cpp b/Source/Core/Core/NetPlayClient.cpp
index 8bb26feeb8..77c9a06e71 100644
--- a/Source/Core/Core/NetPlayClient.cpp
+++ b/Source/Core/Core/NetPlayClient.cpp
@@ -38,10 +38,25 @@ NetPlayClient::~NetPlayClient()
 		Disconnect();
 	}
 
+	if (g_MainNetHost.get() == m_client)
+	{
+		g_MainNetHost.release();
+	}
+	if (m_client)
+	{
+		enet_host_destroy(m_client);
+		m_client = nullptr;
+	}
+
+	if (m_traversal_client)
+	{
+		ReleaseTraversalClient();
+	}
+
 }
 
 // called from ---GUI--- thread
-NetPlayClient::NetPlayClient(const std::string& address, const u16 port, NetPlayUI* dialog, const std::string& name)
+NetPlayClient::NetPlayClient(const std::string& address, const u16 port, NetPlayUI* dialog, const std::string& name, bool traversal)
 	: m_dialog(dialog)
 	, m_client(nullptr)
 	, m_server(nullptr)
@@ -53,6 +68,8 @@ NetPlayClient::NetPlayClient(const std::string& address, const u16 port, NetPlay
 	, m_is_recording(false)
 	, m_pid(0)
 	, m_connecting(false)
+	, m_traversal_client(nullptr)
+	, m_state(Failure)
 {
 	m_target_buffer_size = 20;
 	ClearBuffers();
@@ -61,35 +78,81 @@ NetPlayClient::NetPlayClient(const std::string& address, const u16 port, NetPlay
 
 	m_player_name = name;
 
-	//Direct Connection
-	m_client = enet_host_create(nullptr, 1, 3, 0, 0);
-
-	if (m_client == nullptr)
+	if (!traversal)
 	{
-		PanicAlertT("Couldn't Create Client");
-	}
+		//Direct Connection
+		m_client = enet_host_create(nullptr, 1, 3, 0, 0);
 
-	ENetAddress addr;
-	enet_address_set_host(&addr, address.c_str());
-	addr.port = port;
+		if (m_client == nullptr)
+		{
+			PanicAlertT("Couldn't Create Client");
+		}
 
-	m_server = enet_host_connect(m_client, &addr, 3, 0);
+		ENetAddress addr;
+		enet_address_set_host(&addr, address.c_str());
+		addr.port = port;
 
-	if (m_server == nullptr)
-	{
-		PanicAlertT("Couldn't create peer.");
-	}
+		m_server = enet_host_connect(m_client, &addr, 3, 0);
+
+		if (m_server == nullptr)
+		{
+			PanicAlertT("Couldn't create peer.");
+		}
+
+		ENetEvent netEvent;
+		int net = enet_host_service(m_client, &netEvent, 5000);
+		if (net > 0 && netEvent.type == ENET_EVENT_TYPE_CONNECT)
+		{
+			if (Connect())
+				m_thread = std::thread(&NetPlayClient::ThreadFunc, this);
+		}
+		else
+		{
+			PanicAlertT("Failed to Connect!");
+		}
 
-	ENetEvent netEvent;
-	int net = enet_host_service(m_client, &netEvent, 5000);
-	if (net > 0 && netEvent.type == ENET_EVENT_TYPE_CONNECT)
-	{
-		if (Connect())
-			m_thread = std::thread(&NetPlayClient::ThreadFunc, this);
 	}
 	else
 	{
-		PanicAlertT("Failed to Connect!");
+		//Traversal Server
+		if (!EnsureTraversalClient("dolphin-emu.org", 0))
+			return;
+		m_client = g_MainNetHost.get();
+
+		m_traversal_client = g_TraversalClient.get();
+
+		// If we were disconnected in the background, reconnect.
+		if (m_traversal_client->m_State == TraversalClient::Failure)
+			m_traversal_client->ReconnectToServer();
+		m_traversal_client->m_Client = this;
+		m_host_spec = address;
+		m_state = WaitingForTraversalClientConnection;
+		OnTraversalStateChanged();
+		m_connecting = true;
+
+		while (m_connecting)
+		{
+			ENetEvent netEvent;
+			if (m_traversal_client)
+				m_traversal_client->HandleResends();
+
+			while (enet_host_service(m_client, &netEvent, 4) > 0)
+			{
+				sf::Packet rpac;
+				switch (netEvent.type)
+				{
+				case ENET_EVENT_TYPE_CONNECT:
+					m_server = netEvent.peer;
+					if (Connect())
+					{
+						m_state = Connected;
+						m_thread = std::thread(&NetPlayClient::ThreadFunc, this);
+					}
+					return;
+				}
+			}
+		}
+		PanicAlertT("Failed To Connect!");
 	}
 }
 
@@ -380,6 +443,7 @@ void NetPlayClient::Send(sf::Packet& packet)
 void NetPlayClient::Disconnect()
 {
 	ENetEvent netEvent;
+	m_state = Failure;
 	enet_peer_disconnect(m_server, 0);
 	while (enet_host_service(m_client, &netEvent, 3000) > 0)
 	{
@@ -407,6 +471,8 @@ void NetPlayClient::ThreadFunc()
 		int net;
 		{
 			std::lock_guard<std::recursive_mutex> lks(m_crit.send);
+			if (m_traversal_client)
+				m_traversal_client->HandleResends();
 			net = enet_host_service(m_client, &netEvent, 4);
 		}
 		if (net > 0)
@@ -630,6 +696,55 @@ void NetPlayClient::ClearBuffers()
 	}
 }
 
+// called from ---NETPLAY--- thread
+void NetPlayClient::OnTraversalStateChanged()
+{
+	if (m_state == WaitingForTraversalClientConnection &&
+		m_traversal_client->m_State == TraversalClient::Connected)
+	{
+		m_state = WaitingForTraversalClientConnectReady;
+		m_traversal_client->ConnectToClient(m_host_spec);
+	}
+	else if (m_state != Failure &&
+		m_traversal_client->m_State == TraversalClient::Failure)
+	{
+		Disconnect();
+	}
+}
+
+// called from ---NETPLAY--- thread
+void NetPlayClient::OnConnectReady(ENetAddress addr)
+{
+	if (m_state == WaitingForTraversalClientConnectReady)
+	{
+		m_state = Connecting;
+		enet_host_connect(m_client, &addr, 0, 0);
+	}
+}
+
+// called from ---NETPLAY--- thread
+void NetPlayClient::OnConnectFailed(u8 reason)
+{
+	m_connecting = false;
+	m_state = Failure;
+	int swtch = TraversalClient::ConnectFailedError + reason;
+	switch (swtch)
+	{
+	case TraversalClient::ConnectFailedError + TraversalConnectFailedClientDidntRespond:
+		PanicAlertT("Traversal server timed out connecting to the host");
+		break;
+	case TraversalClient::ConnectFailedError + TraversalConnectFailedClientFailure:
+		PanicAlertT("Server rejected traversal attempt");
+		break;
+	case TraversalClient::ConnectFailedError + TraversalConnectFailedNoSuchClient:
+		PanicAlertT("Invalid host");
+		break;
+	default:
+		PanicAlertT("Unknown error %x", swtch);
+		break;
+	}
+}
+
 // called from ---CPU--- thread
 bool NetPlayClient::GetNetPads(const u8 pad_nb, GCPadStatus* pad_status)
 {
diff --git a/Source/Core/Core/NetPlayClient.h b/Source/Core/Core/NetPlayClient.h
index 6d923f0697..fab8e6548f 100644
--- a/Source/Core/Core/NetPlayClient.h
+++ b/Source/Core/Core/NetPlayClient.h
@@ -7,12 +7,11 @@
 #include <map>
 #include <queue>
 #include <sstream>
-
-#include "enet/enet.h"
 #include "Common/CommonTypes.h"
 #include "Common/FifoQueue.h"
 #include "Common/Thread.h"
 #include "Common/Timer.h"
+#include "Common/TraversalClient.h"
 #include "Core/NetPlayProto.h"
 #include "InputCommon/GCPadStatus.h"
 #include <SFML/Network/Packet.hpp>
@@ -43,12 +42,12 @@ public:
 	u32         ping;
 };
 
-class NetPlayClient
+class NetPlayClient : public TraversalClientClient
 {
 public:
 	void ThreadFunc();
 
-	NetPlayClient(const std::string& address, const u16 port, NetPlayUI* dialog, const std::string& name);
+	NetPlayClient(const std::string& address, const u16 port, NetPlayUI* dialog, const std::string& name, bool traversal);
 	~NetPlayClient();
 
 	void GetPlayerList(std::string& list, std::vector<int>& pid_list);
@@ -66,11 +65,25 @@ public:
 	bool WiimoteUpdate(int _number, u8* data, const u8 size);
 	bool GetNetPads(const u8 pad_nb, GCPadStatus* pad_status);
 
+	void OnTraversalStateChanged() override;
+	void OnConnectReady(ENetAddress addr) override;
+	void OnConnectFailed(u8 reason) override;
+
 	u8 LocalPadToInGamePad(u8 localPad);
 	u8 InGamePadToLocalPad(u8 localPad);
 
 	u8 LocalWiimoteToInGameWiimote(u8 local_pad);
 
+	enum State
+	{
+		WaitingForTraversalClientConnection,
+		WaitingForTraversalClientConnectReady,
+		Connecting,
+		WaitingForHelloResponse,
+		Connected,
+		Failure
+	} m_state;
+
 protected:
 	void ClearBuffers();
 
@@ -121,6 +134,7 @@ private:
 	std::string m_host_spec;
 	std::string m_player_name;
 	bool m_connecting;
+	TraversalClient* m_traversal_client;
 };
 
 void NetPlay_Enable(NetPlayClient* const np);
diff --git a/Source/Core/Core/NetPlayProto.h b/Source/Core/Core/NetPlayProto.h
index 255635810b..b7409fa54b 100644
--- a/Source/Core/Core/NetPlayProto.h
+++ b/Source/Core/Core/NetPlayProto.h
@@ -34,32 +34,31 @@ typedef std::vector<u8> NetWiimote;
 
 static const int NETPLAY_INITIAL_GCTIME = 1272737767;
 
-
 // messages
 enum
 {
-	NP_MSG_PLAYER_JOIN      = 0x10,
-	NP_MSG_PLAYER_LEAVE     = 0x11,
+	NP_MSG_PLAYER_JOIN = 0x10,
+	NP_MSG_PLAYER_LEAVE = 0x11,
 
-	NP_MSG_CHAT_MESSAGE     = 0x30,
+	NP_MSG_CHAT_MESSAGE = 0x30,
 
-	NP_MSG_PAD_DATA         = 0x60,
-	NP_MSG_PAD_MAPPING      = 0x61,
-	NP_MSG_PAD_BUFFER       = 0x62,
+	NP_MSG_PAD_DATA = 0x60,
+	NP_MSG_PAD_MAPPING = 0x61,
+	NP_MSG_PAD_BUFFER = 0x62,
 
-	NP_MSG_WIIMOTE_DATA     = 0x70,
-	NP_MSG_WIIMOTE_MAPPING  = 0x71,
+	NP_MSG_WIIMOTE_DATA = 0x70,
+	NP_MSG_WIIMOTE_MAPPING = 0x71,
 
-	NP_MSG_START_GAME       = 0xA0,
-	NP_MSG_CHANGE_GAME      = 0xA1,
-	NP_MSG_STOP_GAME        = 0xA2,
-	NP_MSG_DISABLE_GAME     = 0xA3,
+	NP_MSG_START_GAME = 0xA0,
+	NP_MSG_CHANGE_GAME = 0xA1,
+	NP_MSG_STOP_GAME = 0xA2,
+	NP_MSG_DISABLE_GAME = 0xA3,
 
-	NP_MSG_READY            = 0xD0,
-	NP_MSG_NOT_READY        = 0xD1,
+	NP_MSG_READY = 0xD0,
+	NP_MSG_NOT_READY = 0xD1,
 
-	NP_MSG_PING             = 0xE0,
-	NP_MSG_PONG             = 0xE1,
+	NP_MSG_PING = 0xE0,
+	NP_MSG_PONG = 0xE1,
 	NP_MSG_PLAYER_PING_DATA = 0xE2,
 };
 
@@ -70,8 +69,8 @@ typedef u32 FrameNum;
 
 enum
 {
-	CON_ERR_SERVER_FULL      = 1,
-	CON_ERR_GAME_RUNNING     = 2,
+	CON_ERR_SERVER_FULL = 1,
+	CON_ERR_GAME_RUNNING = 2,
 	CON_ERR_VERSION_MISMATCH = 3
 };
 
diff --git a/Source/Core/Core/NetPlayServer.cpp b/Source/Core/Core/NetPlayServer.cpp
index f8861c32e4..9282d71dbc 100644
--- a/Source/Core/Core/NetPlayServer.cpp
+++ b/Source/Core/Core/NetPlayServer.cpp
@@ -19,6 +19,17 @@ NetPlayServer::~NetPlayServer()
 		m_do_loop = false;
 		m_thread.join();
 		enet_host_destroy(m_server);
+
+		if (g_MainNetHost.get() == m_server)
+		{
+			g_MainNetHost.release();
+		}
+
+		if (m_traversal_client)
+		{
+			g_TraversalClient->m_Client = nullptr;
+			ReleaseTraversalClient();
+		}
 	}
 
 #ifdef USE_UPNP
@@ -30,7 +41,7 @@ NetPlayServer::~NetPlayServer()
 }
 
 // called from ---GUI--- thread
-NetPlayServer::NetPlayServer(const u16 port)
+NetPlayServer::NetPlayServer(const u16 port, bool traversal)
 	: is_connected(false)
 	, m_is_running(false)
 	, m_do_loop(false)
@@ -40,6 +51,8 @@ NetPlayServer::NetPlayServer(const u16 port)
 	, m_target_buffer_size(0)
 	, m_selected_game("")
 	, m_server(nullptr)
+	, m_traversal_client(nullptr)
+	, m_dialog(nullptr)
 {
 	//--use server time
 	if (enet_initialize() != 0)
@@ -49,11 +62,26 @@ NetPlayServer::NetPlayServer(const u16 port)
 
 	memset(m_pad_map, -1, sizeof(m_pad_map));
 	memset(m_wiimote_map, -1, sizeof(m_wiimote_map));
-		
-	ENetAddress serverAddr;
-	serverAddr.host = ENET_HOST_ANY;
-	serverAddr.port = port;
-	m_server = enet_host_create(&serverAddr, 10, 3, 0, 0);
+	if (traversal)
+	{
+		if (!EnsureTraversalClient("dolphin-emu.org", 0))
+			return;
+
+		g_TraversalClient->m_Client = this;
+		m_traversal_client = g_TraversalClient.get();
+
+		m_server = g_MainNetHost.get();
+
+		if (g_TraversalClient->m_State == TraversalClient::Failure)
+			g_TraversalClient->ReconnectToServer();
+	}
+	else
+	{
+		ENetAddress serverAddr;
+		serverAddr.host = ENET_HOST_ANY;
+		serverAddr.port = port;
+		m_server = enet_host_create(&serverAddr, 10, 3, 0, 0);
+	}
 
 	if (m_server != nullptr)
 	{
@@ -89,6 +117,8 @@ void NetPlayServer::ThreadFunc()
 		int net;
 		{
 			std::lock_guard<std::recursive_mutex> lks(m_crit.send);
+			if (m_traversal_client)
+				m_traversal_client->HandleResends();
 			net = enet_host_service(m_server, &netEvent, 4);
 		}
 		if (net > 0)
@@ -533,6 +563,13 @@ unsigned int NetPlayServer::OnData(sf::Packet& packet, Client& player)
 	return 0;
 }
 
+
+void NetPlayServer::OnTraversalStateChanged()
+{
+	if (m_dialog)
+		m_dialog->Update();
+}
+
 // called from ---GUI--- thread / and ---NETPLAY--- thread
 void NetPlayServer::SendChatMessage(const std::string& msg)
 {
@@ -638,6 +675,96 @@ u16 NetPlayServer::GetPort()
 	return m_server->address.port;
 }
 
+void NetPlayServer::SetNetPlayUI(NetPlayUI* dialog)
+{
+	m_dialog = dialog;
+}
+
+// called from ---GUI--- thread
+std::unordered_set<std::string> NetPlayServer::GetInterfaceSet()
+{
+	std::unordered_set<std::string> result;
+	auto lst = GetInterfaceListInternal();
+	for (auto list_entry : lst)
+		result.emplace(list_entry.first);
+	return result;
+}
+
+// called from ---GUI--- thread
+std::string NetPlayServer::GetInterfaceHost(const std::string inter)
+{
+	char buf[16];
+	sprintf(buf, ":%d", GetPort());
+	auto lst = GetInterfaceListInternal();
+	for (const auto& list_entry : lst)
+	{
+		if (list_entry.first == inter)
+		{
+			return list_entry.second + buf;
+		}
+	}
+	return "?";
+}
+
+// called from ---GUI--- thread
+std::vector<std::pair<std::string, std::string>> NetPlayServer::GetInterfaceListInternal()
+{
+	std::vector<std::pair<std::string, std::string>> result;
+#if defined(_WIN32)
+
+#elif defined(__APPLE__)
+	// we do this to get the friendly names rather than the BSD ones. ew.
+	if (m_dynamic_store && m_prefs)
+	{
+		CFArrayRef ary = SCNetworkServiceCopyAll((SCPreferencesRef)m_prefs);
+		for (CFIndex i = 0; i < CFArrayGetCount(ary); i++)
+		{
+			SCNetworkServiceRef ifr = (SCNetworkServiceRef)CFArrayGetValueAtIndex(ary, i);
+			std::string name = CFStrToStr(SCNetworkServiceGetName(ifr));
+			CFStringRef key = SCDynamicStoreKeyCreateNetworkServiceEntity(NULL, kSCDynamicStoreDomainState, SCNetworkServiceGetServiceID(ifr), kSCEntNetIPv4);
+			CFDictionaryRef props = (CFDictionaryRef)SCDynamicStoreCopyValue((SCDynamicStoreRef)m_dynamic_store, key);
+			CFRelease(key);
+			if (!props)
+				continue;
+			CFArrayRef ipary = (CFArrayRef)CFDictionaryGetValue(props, kSCPropNetIPv4Addresses);
+			if (ipary)
+			{
+				for (CFIndex j = 0; j < CFArrayGetCount(ipary); j++)
+					result.emplace_back(std::make_pair(name, CFStrToStr((CFStringRef)CFArrayGetValueAtIndex(ipary, j))));
+				CFRelease(ipary);
+			}
+		}
+		CFRelease(ary);
+	}
+#elif defined(ANDROID)
+	// Android has no getifaddrs for some stupid reason.  If this
+	// functionality ends up actually being used on Android, fix this.
+#else
+	ifaddrs* ifp;
+	char buf[512];
+	if (getifaddrs(&ifp) != -1)
+	{
+		for (struct ifaddrs* curifp = ifp; curifp; curifp = curifp->ifa_next)
+		{
+			struct sockaddr* sa = curifp->ifa_addr;
+			if (sa->sa_family != AF_INET)
+				continue;
+			struct sockaddr_in* sai = (struct sockaddr_in*) sa;
+			if (ntohl(((struct sockaddr_in*) sa)->sin_addr.s_addr) == 0x7f000001)
+				continue;
+			const char* ip = inet_ntop(sa->sa_family, &sai->sin_addr, buf, sizeof(buf));
+			if (ip == nullptr)
+				continue;
+			result.emplace_back(std::make_pair(curifp->ifa_name, ip));
+		}
+		freeifaddrs(ifp);
+	}
+#endif
+	if (result.empty())
+		result.push_back(std::make_pair("!local!", "127.0.0.1"));
+	return result;
+}
+
 #ifdef USE_UPNP
 #include <miniwget.h>
 #include <miniupnpc.h>
diff --git a/Source/Core/Core/NetPlayServer.h b/Source/Core/Core/NetPlayServer.h
index d82195f5f7..6fa7909822 100644
--- a/Source/Core/Core/NetPlayServer.h
+++ b/Source/Core/Core/NetPlayServer.h
@@ -9,18 +9,20 @@
 #include <sstream>
 #include <unordered_set>
 
-#include "enet/enet.h"
 #include "Common/Thread.h"
+#include "Common/TraversalClient.h"
 #include "Common/Timer.h"
 #include "Core/NetPlayProto.h"
 #include <SFML/Network/Packet.hpp>
 
-class NetPlayServer
+class NetPlayUI;
+
+class NetPlayServer : public TraversalClientClient
 {
 public:
 	void ThreadFunc();
 
-	NetPlayServer(const u16 port);
+	NetPlayServer(const u16 port, bool traversal);
 	~NetPlayServer();
 
 	bool ChangeGame(const std::string& game);
@@ -42,6 +44,10 @@ public:
 
 	u16 GetPort();
 
+	void SetNetPlayUI(NetPlayUI* dialog);
+	std::unordered_set<std::string> GetInterfaceSet();
+	std::string GetInterfaceHost(const std::string inter);
+
 	bool is_connected;
 
 #ifdef USE_UPNP
@@ -71,8 +77,12 @@ private:
 	unsigned int OnConnect(ENetPeer* socket);
 	unsigned int OnDisconnect(Client& player);
 	unsigned int OnData(sf::Packet& packet, Client& player);
+	virtual void OnTraversalStateChanged();
+	virtual void OnConnectReady(ENetAddress addr) {}
+	virtual void OnConnectFailed(u8 reason) {}
 	void UpdatePadMapping();
 	void UpdateWiimoteMapping();
+	std::vector<std::pair<std::string, std::string>> GetInterfaceListInternal();
 
 	NetSettings     m_settings;
 
@@ -99,6 +109,8 @@ private:
 	std::thread m_thread;
 
 	ENetHost*        m_server;
+	TraversalClient* m_traversal_client;
+	NetPlayUI*       m_dialog;
 
 #ifdef USE_UPNP
 	static void mapPortThread(const u16 port);
diff --git a/Source/Core/DolphinWX/NetWindow.cpp b/Source/Core/DolphinWX/NetWindow.cpp
index eb15e533a0..8d99a9403b 100644
--- a/Source/Core/DolphinWX/NetWindow.cpp
+++ b/Source/Core/DolphinWX/NetWindow.cpp
@@ -27,6 +27,7 @@
 #include <wx/string.h>
 #include <wx/textctrl.h>
 #include <wx/translation.h>
+#include <wx/clipbrd.h>
 
 #include "Common/CommonTypes.h"
 #include "Common/FifoQueue.h"
@@ -53,6 +54,26 @@ static NetPlayServer* netplay_server = nullptr;
 static NetPlayClient* netplay_client = nullptr;
 NetPlayDiag *NetPlayDiag::npd = nullptr;
 
+
+static wxString FailureReasonStringForHostLabel(int reason)
+{
+	switch (reason)
+	{
+	case TraversalClient::BadHost:
+		return _("(Error: Bad host)");
+	case TraversalClient::VersionTooOld:
+		return _("(Error: Dolphin too old)");
+	case TraversalClient::ServerForgotAboutUs:
+		return _("(Error: Disconnected)");
+	case TraversalClient::SocketSendError:
+		return _("(Error: Socket)");
+	case TraversalClient::ResendTimeout:
+		return _("(Error: Timeout)");
+	default:
+		return _("(Error: Unknown)");
+	}
+}
+
 static std::string BuildGameName(const GameListItem& game)
 {
 	// Lang needs to be consistent
@@ -93,7 +114,6 @@ NetPlaySetupDiag::NetPlaySetupDiag(wxWindow* const parent, const CGameListCtrl*
 	nick_szr->Add(nick_lbl, 0, wxCENTER);
 	nick_szr->Add(m_nickname_text, 0, wxALL, 5);
 
-
 	// tabs
 	wxNotebook* const notebook = new wxNotebook(panel, wxID_ANY);
 	wxPanel* const connect_tab = new wxPanel(notebook, wxID_ANY);
@@ -101,85 +121,91 @@ NetPlaySetupDiag::NetPlaySetupDiag(wxWindow* const parent, const CGameListCtrl*
 	wxPanel* const host_tab = new wxPanel(notebook, wxID_ANY);
 	notebook->AddPage(host_tab, _("Host"));
 
+	m_direct_traversal = new wxChoice(panel, wxID_ANY, wxDefaultPosition, wxSize(75, -1));
+	m_direct_traversal->Bind(wxEVT_COMMAND_CHOICE_SELECTED, &NetPlaySetupDiag::OnChoice, this);
+	m_direct_traversal->Append(_("Traversal"));
+	m_direct_traversal->Append(_("Direct"));
+	m_direct_traversal->Select(0);
 
 	// connect tab
 	{
-	wxStaticText* const ip_lbl = new wxStaticText(connect_tab, wxID_ANY, _("Address :"));
-
-	std::string address;
-	netplay_section.Get("Address", &address, "localhost");
-	m_connect_ip_text = new wxTextCtrl(connect_tab, wxID_ANY, StrToWxStr(address));
-
-	wxStaticText* const port_lbl = new wxStaticText(connect_tab, wxID_ANY, _("Port :"));
-
-	// string? w/e
-	std::string port;
-	netplay_section.Get("ConnectPort", &port, "2626");
-	m_connect_port_text = new wxTextCtrl(connect_tab, wxID_ANY, StrToWxStr(port));
-
-	wxButton* const connect_btn = new wxButton(connect_tab, wxID_ANY, _("Connect"));
-	connect_btn->Bind(wxEVT_BUTTON, &NetPlaySetupDiag::OnJoin, this);
-
-	wxStaticText* const alert_lbl = new wxStaticText(connect_tab, wxID_ANY,
-		_("ALERT:\n\n"
-		"Netplay will only work with the following settings:\n"
-		" - DSP Emulator Engine Must be the same on all computers!\n"
-		" - DSP on Dedicated Thread [OFF]\n"
-		" - Manually set the extensions for each Wiimote\n"
-		"\n"
-		"All players should use the same Dolphin version and settings.\n"
-		"All memory cards must be identical between players or disabled.\n"
-		"Wiimote support is probably terrible. Don't use it.\n"
-		"\n"
-		"The host must have the chosen TCP port open/forwarded!\n"));
-
-	wxBoxSizer* const top_szr = new wxBoxSizer(wxHORIZONTAL);
-	top_szr->Add(ip_lbl, 0, wxCENTER | wxRIGHT, 5);
-	top_szr->Add(m_connect_ip_text, 3);
-	top_szr->Add(port_lbl, 0, wxCENTER | wxRIGHT | wxLEFT, 5);
-	top_szr->Add(m_connect_port_text, 1);
-
-	wxBoxSizer* const con_szr = new wxBoxSizer(wxVERTICAL);
-	con_szr->Add(top_szr, 0, wxALL | wxEXPAND, 5);
-	con_szr->AddStretchSpacer(1);
-	con_szr->Add(alert_lbl, 0, wxLEFT | wxRIGHT | wxEXPAND, 5);
-	con_szr->AddStretchSpacer(1);
-	con_szr->Add(connect_btn, 0, wxALL | wxALIGN_RIGHT, 5);
-
-	connect_tab->SetSizerAndFit(con_szr);
+		m_ip_lbl = new wxStaticText(connect_tab, wxID_ANY, _("Host Code :"));
+
+		std::string address;
+		netplay_section.Get("HostCode", &address, "00000000");
+		m_connect_ip_text = new wxTextCtrl(connect_tab, wxID_ANY, StrToWxStr(address));
+
+		m_client_port_lbl = new wxStaticText(connect_tab, wxID_ANY, _("Port :"));
+
+		// string? w/e
+		std::string port;
+		netplay_section.Get("ConnectPort", &port, "2626");
+		m_connect_port_text = new wxTextCtrl(connect_tab, wxID_ANY, StrToWxStr(port));
+
+		wxButton* const connect_btn = new wxButton(connect_tab, wxID_ANY, _("Connect"));
+		connect_btn->Bind(wxEVT_BUTTON, &NetPlaySetupDiag::OnJoin, this);
+
+		wxStaticText* const alert_lbl = new wxStaticText(connect_tab, wxID_ANY,
+			_("ALERT:\n\n"
+			"Netplay will only work with the following settings:\n"
+			" - DSP Emulator Engine Must be the same on all computers!\n"
+			" - DSP on Dedicated Thread [OFF]\n"
+			" - Manually set the extensions for each Wiimote\n"
+			"\n"
+			"All players should use the same Dolphin version and settings.\n"
+			"All memory cards must be identical between players or disabled.\n"
+			"Wiimote support is probably terrible. Don't use it.\n"
+			"\n"
+			"If connecting directly host must have the chosen UDP port open/forwarded!\n"));
+
+		wxBoxSizer* const top_szr = new wxBoxSizer(wxHORIZONTAL);
+
+		top_szr->Add(m_ip_lbl, 0, wxCENTER | wxRIGHT, 5);
+		top_szr->Add(m_connect_ip_text, 3);
+		top_szr->Add(m_client_port_lbl, 0, wxCENTER | wxRIGHT | wxLEFT, 5);
+		top_szr->Add(m_connect_port_text, 1);
+
+		wxBoxSizer* const con_szr = new wxBoxSizer(wxVERTICAL);
+		con_szr->Add(top_szr, 0, wxALL | wxEXPAND, 5);
+		con_szr->AddStretchSpacer(1);
+		con_szr->Add(alert_lbl, 0, wxLEFT | wxRIGHT | wxEXPAND, 5);
+		con_szr->AddStretchSpacer(1);
+		con_szr->Add(connect_btn, 0, wxALL | wxALIGN_RIGHT, 5);
+
+		connect_tab->SetSizerAndFit(con_szr);
 	}
 
 	// host tab
 	{
-	wxStaticText* const port_lbl = new wxStaticText(host_tab, wxID_ANY, _("Port :"));
+		m_host_port_lbl = new wxStaticText(host_tab, wxID_ANY, _("Port :"));
 
-	// string? w/e
-	std::string port;
-	netplay_section.Get("HostPort", &port, "2626");
-	m_host_port_text = new wxTextCtrl(host_tab, wxID_ANY, StrToWxStr(port));
+		// string? w/e
+		std::string port;
+		netplay_section.Get("HostPort", &port, "2626");
+		m_host_port_text = new wxTextCtrl(host_tab, wxID_ANY, StrToWxStr(port));
 
-	wxButton* const host_btn = new wxButton(host_tab, wxID_ANY, _("Host"));
-	host_btn->Bind(wxEVT_BUTTON, &NetPlaySetupDiag::OnHost, this);
+		wxButton* const host_btn = new wxButton(host_tab, wxID_ANY, _("Host"));
+		host_btn->Bind(wxEVT_BUTTON, &NetPlaySetupDiag::OnHost, this);
 
-	m_game_lbox = new wxListBox(host_tab, wxID_ANY, wxDefaultPosition, wxDefaultSize, 0, nullptr, wxLB_SORT);
-	m_game_lbox->Bind(wxEVT_LISTBOX_DCLICK, &NetPlaySetupDiag::OnHost, this);
+		m_game_lbox = new wxListBox(host_tab, wxID_ANY, wxDefaultPosition, wxDefaultSize, 0, nullptr, wxLB_SORT);
+		m_game_lbox->Bind(wxEVT_LISTBOX_DCLICK, &NetPlaySetupDiag::OnHost, this);
 
-	FillWithGameNames(m_game_lbox, *game_list);
+		FillWithGameNames(m_game_lbox, *game_list);
 
-	wxBoxSizer* const top_szr = new wxBoxSizer(wxHORIZONTAL);
-	top_szr->Add(port_lbl, 0, wxCENTER | wxRIGHT, 5);
-	top_szr->Add(m_host_port_text, 0);
+		wxBoxSizer* const top_szr = new wxBoxSizer(wxHORIZONTAL);
+		top_szr->Add(m_host_port_lbl, 0, wxCENTER | wxRIGHT, 5);
+		top_szr->Add(m_host_port_text, 0);
 #ifdef USE_UPNP
-	m_upnp_chk = new wxCheckBox(host_tab, wxID_ANY, _("Forward port (UPnP)"));
-	top_szr->Add(m_upnp_chk, 0, wxALL | wxALIGN_RIGHT, 5);
+		m_upnp_chk = new wxCheckBox(host_tab, wxID_ANY, _("Forward port (UPnP)"));
+		top_szr->Add(m_upnp_chk, 0, wxALL | wxALIGN_RIGHT, 5);
 #endif
 
-	wxBoxSizer* const host_szr = new wxBoxSizer(wxVERTICAL);
-	host_szr->Add(top_szr, 0, wxALL | wxEXPAND, 5);
-	host_szr->Add(m_game_lbox, 1, wxLEFT | wxRIGHT | wxEXPAND, 5);
-	host_szr->Add(host_btn, 0, wxALL | wxALIGN_RIGHT, 5);
+		wxBoxSizer* const host_szr = new wxBoxSizer(wxVERTICAL);
+		host_szr->Add(top_szr, 0, wxALL | wxEXPAND, 5);
+		host_szr->Add(m_game_lbox, 1, wxLEFT | wxRIGHT | wxEXPAND, 5);
+		host_szr->Add(host_btn, 0, wxALL | wxALIGN_RIGHT, 5);
 
-	host_tab->SetSizerAndFit(host_szr);
+		host_tab->SetSizerAndFit(host_szr);
 	}
 
 	// bottom row
@@ -202,6 +228,21 @@ NetPlaySetupDiag::NetPlaySetupDiag(wxWindow* const parent, const CGameListCtrl*
 
 	Center();
 	Show();
+
+	//  Needs to be done last or it set up the spacing on the page correctly
+	//client tab
+	{
+		m_client_port_lbl->Show(false);
+		m_connect_port_text->Show(false);
+	}
+
+	//server tab
+	{
+		m_host_port_lbl->Show(false);
+		m_host_port_text->Show(false);
+		m_upnp_chk->Show(false);
+	}
+
 }
 
 NetPlaySetupDiag::~NetPlaySetupDiag()
@@ -212,7 +253,14 @@ NetPlaySetupDiag::~NetPlaySetupDiag()
 	IniFile::Section& netplay_section = *inifile.GetOrCreateSection("NetPlay");
 
 	netplay_section.Set("Nickname", WxStrToStr(m_nickname_text->GetValue()));
-	netplay_section.Set("Address", WxStrToStr(m_connect_ip_text->GetValue()));
+	if (m_direct_traversal->GetCurrentSelection() == 1)
+	{
+		netplay_section.Set("Address", WxStrToStr(m_connect_ip_text->GetValue()));
+	}
+	else
+	{
+		netplay_section.Set("HostCode", WxStrToStr(m_connect_ip_text->GetValue()));
+	}
 	netplay_section.Set("ConnectPort", WxStrToStr(m_connect_port_text->GetValue()));
 	netplay_section.Set("HostPort", WxStrToStr(m_host_port_text->GetValue()));
 
@@ -230,7 +278,13 @@ void NetPlaySetupDiag::MakeNetPlayDiag(int port, const std::string &game, bool i
 	else
 		ip = WxStrToStr(m_connect_ip_text->GetValue());
 
-	netplay_client = new NetPlayClient(ip, (u16)port, npd, WxStrToStr(m_nickname_text->GetValue()));
+	bool trav;
+	if (!is_hosting && m_direct_traversal->GetCurrentSelection() == 0)
+		trav = true;
+	else
+		trav = false;
+
+	netplay_client = new NetPlayClient(ip, (u16)port, npd, WxStrToStr(m_nickname_text->GetValue()), trav);
 	if (netplay_client->is_connected)
 	{
 		npd->Show();
@@ -259,9 +313,15 @@ void NetPlaySetupDiag::OnHost(wxCommandEvent&)
 
 	std::string game(WxStrToStr(m_game_lbox->GetStringSelection()));
 
+	bool trav;
+	if (m_direct_traversal->GetCurrentSelection() == 0)
+		trav = true;
+	else
+		trav = false;
+
 	unsigned long port = 0;
 	m_host_port_text->GetValue().ToULong(&port);
-	netplay_server = new NetPlayServer(u16(port));
+	netplay_server = new NetPlayServer(u16(port), trav);
 	netplay_server->ChangeGame(game);
 	netplay_server->AdjustPadBufferSize(INITIAL_PAD_BUFFER_SIZE);
 	if (netplay_server->is_connected)
@@ -270,7 +330,8 @@ void NetPlaySetupDiag::OnHost(wxCommandEvent&)
 		if (m_upnp_chk->GetValue())
 			netplay_server->TryPortmapping(port);
 #endif
-		MakeNetPlayDiag(port, game, true);
+		MakeNetPlayDiag(netplay_server->GetPort(), game, true);
+		netplay_server->SetNetPlayUI(NetPlayDiag::GetInstance());
 	}
 	else
 	{
@@ -292,17 +353,75 @@ void NetPlaySetupDiag::OnJoin(wxCommandEvent&)
 	MakeNetPlayDiag(port, "", false);
 }
 
+void NetPlaySetupDiag::OnChoice(wxCommandEvent& event)
+{
+	int sel = m_direct_traversal->GetSelection();
+	IniFile inifile;
+	inifile.Load(File::GetUserPath(D_CONFIG_IDX) + "Dolphin.ini");
+	IniFile::Section& netplay_section = *inifile.GetOrCreateSection("NetPlay");
+
+	if (sel == 0)
+	{
+		//Traversal
+		//client tab
+		{
+			m_ip_lbl->SetLabelText("Host Code: ");
+
+			std::string address;
+			netplay_section.Get("HostCode", &address, "00000000");
+			m_connect_ip_text->SetLabelText(address);
+
+			m_client_port_lbl->Show(false);
+			m_connect_port_text->Show(false);
+		}
+
+		//server tab
+		{
+			m_host_port_lbl->Show(false);
+			m_host_port_text->Show(false);
+			m_upnp_chk->Show(false);
+		}
+	}
+	else
+	{
+		//Direct
+		//client tab
+		{
+			m_ip_lbl->SetLabelText("IP Address :");
+
+			std::string address;
+			netplay_section.Get("Address", &address, "127.0.0.1");
+			m_connect_ip_text->SetLabelText(address);
+
+			m_client_port_lbl->Show(true);
+			m_connect_port_text->Show(true);
+		}
+
+		//server tab
+		{
+			m_host_port_lbl->Show(true);
+			m_host_port_text->Show(true);
+			m_upnp_chk->Show(true);
+		}
+	}
+}
+
 void NetPlaySetupDiag::OnQuit(wxCommandEvent&)
 {
 	Destroy();
 }
 
 NetPlayDiag::NetPlayDiag(wxWindow* const parent, const CGameListCtrl* const game_list,
-		const std::string& game, const bool is_hosting)
+	const std::string& game, const bool is_hosting)
 	: wxFrame(parent, wxID_ANY, _("Dolphin NetPlay"))
 	, m_selected_game(game)
 	, m_start_btn(nullptr)
 	, m_game_list(game_list)
+	, m_host_type_choice(nullptr)
+	, m_host_label(nullptr)
+	, m_host_copy_btn(nullptr)
+	, m_host_copy_btn_is_retry(false)
+	, m_is_hosting(is_hosting)
 {
 	Bind(wxEVT_THREAD, &NetPlayDiag::OnThread, this);
 
@@ -310,10 +429,10 @@ NetPlayDiag::NetPlayDiag(wxWindow* const parent, const CGameListCtrl* const game
 
 	// top crap
 	m_game_btn = new wxButton(panel, wxID_ANY,
-			StrToWxStr(m_selected_game).Prepend(_(" Game : ")),
-			wxDefaultPosition, wxDefaultSize, wxBU_LEFT);
+		StrToWxStr(m_selected_game).Prepend(_(" Game : ")),
+		wxDefaultPosition, wxDefaultSize, wxBU_LEFT);
 
-	if (is_hosting)
+	if (m_is_hosting)
 		m_game_btn->Bind(wxEVT_BUTTON, &NetPlayDiag::OnChangeGame, this);
 	else
 		m_game_btn->Disable();
@@ -343,9 +462,34 @@ NetPlayDiag::NetPlayDiag(wxWindow* const parent, const CGameListCtrl* const game
 	m_player_lbox = new wxListBox(panel, wxID_ANY, wxDefaultPosition, wxSize(256, -1));
 
 	wxStaticBoxSizer* const player_szr = new wxStaticBoxSizer(wxVERTICAL, panel, _("Players"));
-	player_szr->Add(m_player_lbox, 1, wxEXPAND);
+
 	// player list
-	if (is_hosting)
+	if (m_is_hosting && g_TraversalClient)
+	{
+		wxBoxSizer* const host_szr = new wxBoxSizer(wxHORIZONTAL);
+		m_host_type_choice = new wxChoice(panel, wxID_ANY, wxDefaultPosition, wxSize(60, -1));
+		m_host_type_choice->Bind(wxEVT_COMMAND_CHOICE_SELECTED, &NetPlayDiag::OnChoice, this);
+		m_host_type_choice->Append(_("ID:"));
+		host_szr->Add(m_host_type_choice);
+
+		m_host_label = new wxStaticText(panel, wxID_ANY, "555.555.555.555:55555", wxDefaultPosition, wxDefaultSize, wxST_NO_AUTORESIZE | wxALIGN_LEFT);
+		// Update() should fix this immediately.
+		m_host_label->SetLabel(_(""));
+		host_szr->Add(m_host_label, 1, wxLEFT | wxCENTER, 5);
+
+		m_host_copy_btn = new wxButton(panel, wxID_ANY, _("Copy"));
+		m_host_copy_btn->Bind(wxEVT_COMMAND_BUTTON_CLICKED, &NetPlayDiag::OnCopyIP, this);
+		m_host_copy_btn->Disable();
+		host_szr->Add(m_host_copy_btn, 0, wxLEFT | wxCENTER, 5);
+		player_szr->Add(host_szr, 0, wxEXPAND | wxBOTTOM, 5);
+		m_host_type_choice->Select(0);
+
+		UpdateHostLabel();
+	}
+
+	player_szr->Add(m_player_lbox, 1, wxEXPAND);
+
+	if (m_is_hosting)
 	{
 		m_player_lbox->Bind(wxEVT_LISTBOX, &NetPlayDiag::OnPlayerSelect, this);
 		m_kick_btn = new wxButton(panel, wxID_ANY, _("Kick Player"));
@@ -398,7 +542,7 @@ NetPlayDiag::NetPlayDiag(wxWindow* const parent, const CGameListCtrl* const game
 	panel->SetSizerAndFit(main_szr);
 
 	main_szr->SetSizeHints(this);
-	SetSize(512, 512-128);
+	SetSize(512, 512 - 128);
 
 	Center();
 }
@@ -531,6 +675,11 @@ void NetPlayDiag::OnQuit(wxCommandEvent&)
 // update gui
 void NetPlayDiag::OnThread(wxThreadEvent& event)
 {
+	if (m_is_hosting && m_host_label && g_TraversalClient)
+	{
+		UpdateHostLabel();
+	}
+
 	// player list
 	m_playerids.clear();
 	std::string tmps;
@@ -563,8 +712,8 @@ void NetPlayDiag::OnThread(wxThreadEvent& event)
 	// flash window in taskbar when someone joins if window isn't active
 	static u8 numPlayers = 1;
 	bool focus = (wxWindow::FindFocus() == this || (wxWindow::FindFocus() != nullptr && wxWindow::FindFocus()->GetParent() == this) ||
-	             (wxWindow::FindFocus() != nullptr && wxWindow::FindFocus()->GetParent() != nullptr
-	              && wxWindow::FindFocus()->GetParent()->GetParent() == this));
+		(wxWindow::FindFocus() != nullptr && wxWindow::FindFocus()->GetParent() != nullptr
+		&& wxWindow::FindFocus()->GetParent()->GetParent() == this));
 	if (netplay_server != nullptr && numPlayers < m_playerids.size() && !focus)
 	{
 		RequestUserAttention();
@@ -575,25 +724,25 @@ void NetPlayDiag::OnThread(wxThreadEvent& event)
 	{
 	case NP_GUI_EVT_CHANGE_GAME:
 		// update selected game :/
-		{
+	{
 		m_selected_game.assign(WxStrToStr(event.GetString()));
 
 		wxString button_label = event.GetString();
 		m_game_btn->SetLabel(button_label.Prepend(_(" Game : ")));
-		}
-		break;
-	case NP_GUI_EVT_START_GAME :
+	}
+	break;
+	case NP_GUI_EVT_START_GAME:
 		// client start game :/
-		{
+	{
 		netplay_client->StartGame(FindGame());
-		}
-		break;
-	case NP_GUI_EVT_STOP_GAME :
+	}
+	break;
+	case NP_GUI_EVT_STOP_GAME:
 		// client stop game
-		{
+	{
 		netplay_client->StopGame();
-		}
-		break;
+	}
+	break;
 	}
 
 	// chat messages
@@ -660,6 +809,98 @@ bool NetPlayDiag::IsRecording()
 	return m_record_chkbox->GetValue();
 }
 
+
+void NetPlayDiag::OnCopyIP(wxCommandEvent&)
+{
+	if (m_host_copy_btn_is_retry)
+	{
+		g_TraversalClient->ReconnectToServer();
+		Update();
+	}
+	else
+	{
+		if (wxTheClipboard->Open())
+		{
+			wxTheClipboard->SetData(new wxTextDataObject(m_host_label->GetLabel()));
+			wxTheClipboard->Close();
+		}
+	}
+}
+
+void NetPlayDiag::OnChoice(wxCommandEvent& event)
+{
+	UpdateHostLabel();
+}
+
+
+void NetPlayDiag::UpdateHostLabel()
+{
+	wxString label = _(" (internal IP)");
+	auto DeLabel = [=](wxString str) {
+		if (str == _("Localhost"))
+			return std::string("!local!");
+		return WxStrToStr(str.Left(str.Len() - label.Len()));
+	};
+	auto EnLabel = [=](std::string str) -> wxString {
+		if (str == "!local!")
+			return _("Localhost");
+		return StrToWxStr(str) + label;
+	};
+	int sel = m_host_type_choice->GetSelection();
+	if (sel == 0)
+	{
+		// the traversal ID
+		switch (g_TraversalClient->m_State)
+		{
+		case TraversalClient::Connecting:
+			m_host_label->SetForegroundColour(*wxLIGHT_GREY);
+			m_host_label->SetLabel("...");
+			m_host_copy_btn->SetLabel(_("Copy"));
+			m_host_copy_btn->Disable();
+			break;
+		case TraversalClient::Connected:
+			m_host_label->SetForegroundColour(*wxBLACK);
+			m_host_label->SetLabel(wxString(g_TraversalClient->m_HostId.data(), g_TraversalClient->m_HostId.size()));
+			m_host_copy_btn->SetLabel(_("Copy"));
+			m_host_copy_btn->Enable();
+			m_host_copy_btn_is_retry = false;
+			break;
+		case TraversalClient::Failure:
+			m_host_label->SetForegroundColour(*wxBLACK);
+			m_host_label->SetLabel(FailureReasonStringForHostLabel(g_TraversalClient->m_FailureReason));
+			m_host_copy_btn->SetLabel(_("Retry"));
+			m_host_copy_btn->Enable();
+			m_host_copy_btn_is_retry = true;
+			break;
+		}
+	}
+	else if (sel != wxNOT_FOUND) // wxNOT_FOUND shouldn't generally happen
+	{
+		m_host_label->SetForegroundColour(*wxBLACK);
+		m_host_label->SetLabel(netplay_server->GetInterfaceHost(DeLabel(m_host_type_choice->GetString(sel))));
+		m_host_copy_btn->SetLabel(_("Copy"));
+		m_host_copy_btn->Enable();
+		m_host_copy_btn_is_retry = false;
+	}
+
+	auto set = netplay_server->GetInterfaceSet();
+	for (const std::string& iface : set)
+	{
+		wxString wxIface = EnLabel(iface);
+		if (m_host_type_choice->FindString(wxIface) == wxNOT_FOUND)
+			m_host_type_choice->Append(wxIface);
+	}
+	for (unsigned i = 1, count = m_host_type_choice->GetCount(); i != count; i++)
+	{
+		if (set.find(DeLabel(m_host_type_choice->GetString(i))) == set.end())
+		{
+			m_host_type_choice->Delete(i);
+			i--;
+			count--;
+		}
+	}
+}
+
 ChangeGameDiag::ChangeGameDiag(wxWindow* const parent, const CGameListCtrl* const game_list, wxString& game_name)
 	: wxDialog(parent, wxID_ANY, _("Change Game"))
 	, m_game_name(game_name)
@@ -728,16 +969,16 @@ PadMapDiag::PadMapDiag(wxWindow* const parent, PadMapping map[], PadMapping wiim
 		v_szr->Add(new wxStaticText(this, wxID_ANY, (wxString(_("Wiimote ")) + (wxChar)('0' + i))),
 		                            1, wxALIGN_CENTER_HORIZONTAL);
 
-		m_map_cbox[i+4] = new wxChoice(this, wxID_ANY, wxDefaultPosition, wxDefaultSize, player_names);
-		m_map_cbox[i+4]->Bind(wxEVT_CHOICE, &PadMapDiag::OnAdjust, this);
+		m_map_cbox[i + 4] = new wxChoice(this, wxID_ANY, wxDefaultPosition, wxDefaultSize, player_names);
+		m_map_cbox[i + 4]->Bind(wxEVT_CHOICE, &PadMapDiag::OnAdjust, this);
 		if (m_wiimapping[i] == -1)
-			m_map_cbox[i+4]->Select(0);
+			m_map_cbox[i + 4]->Select(0);
 		else
 			for (unsigned int j = 0; j < m_player_list.size(); j++)
 				if (m_wiimapping[i] == m_player_list[j]->pid)
-					m_map_cbox[i+4]->Select(j + 1);
+					m_map_cbox[i + 4]->Select(j + 1);
 
-		v_szr->Add(m_map_cbox[i+4], 1);
+		v_szr->Add(m_map_cbox[i + 4], 1);
 
 		h_szr->Add(v_szr, 1, wxTOP | wxEXPAND, 20);
 		h_szr->AddSpacer(10);
@@ -763,7 +1004,7 @@ void PadMapDiag::OnAdjust(wxCommandEvent& event)
 		else
 			m_mapping[i] = -1;
 
-		player_idx = m_map_cbox[i+4]->GetSelection();
+		player_idx = m_map_cbox[i + 4]->GetSelection();
 		if (player_idx > 0)
 			m_wiimapping[i] = m_player_list[player_idx - 1]->pid;
 		else
diff --git a/Source/Core/DolphinWX/NetWindow.h b/Source/Core/DolphinWX/NetWindow.h
index 90d0dbd8c4..31cbf17b71 100644
--- a/Source/Core/DolphinWX/NetWindow.h
+++ b/Source/Core/DolphinWX/NetWindow.h
@@ -42,10 +42,16 @@ private:
 
 	void MakeNetPlayDiag(int port, const std::string &game, bool is_hosting);
 
-	wxTextCtrl* m_nickname_text;
-	wxTextCtrl* m_host_port_text;
-	wxTextCtrl* m_connect_port_text;
-	wxTextCtrl* m_connect_ip_text;
+	void OnChoice(wxCommandEvent& event);
+
+	wxStaticText* m_ip_lbl;
+	wxStaticText* m_client_port_lbl;
+	wxTextCtrl*   m_nickname_text;
+	wxStaticText* m_host_port_lbl;
+	wxTextCtrl*   m_host_port_text;
+	wxTextCtrl*   m_connect_port_text;
+	wxTextCtrl*   m_connect_ip_text;
+	wxChoice*     m_direct_traversal;
 
 	wxListBox*  m_game_lbox;
 #ifdef USE_UPNP
@@ -93,16 +99,25 @@ private:
 	void GetNetSettings(NetSettings &settings);
 	std::string FindGame();
 
-	wxListBox*   m_player_lbox;
-	wxTextCtrl*  m_chat_text;
-	wxTextCtrl*  m_chat_msg_text;
-	wxCheckBox*  m_memcard_write;
-	wxCheckBox*  m_record_chkbox;
-
-	std::string  m_selected_game;
-	wxButton*    m_game_btn;
-	wxButton*    m_start_btn;
-	wxButton*    m_kick_btn;
+	void OnCopyIP(wxCommandEvent&);
+	void OnChoice(wxCommandEvent& event);
+	void UpdateHostLabel();
+
+	wxListBox*    m_player_lbox;
+	wxTextCtrl*   m_chat_text;
+	wxTextCtrl*	  m_chat_msg_text;
+	wxCheckBox*	  m_memcard_write;
+	wxCheckBox*   m_record_chkbox;
+
+	std::string   m_selected_game;
+	wxButton*     m_game_btn;
+	wxButton*     m_start_btn;
+	wxButton*     m_kick_btn;
+	wxStaticText* m_host_label;
+	wxChoice*     m_host_type_choice;
+	wxButton*     m_host_copy_btn;
+	bool          m_host_copy_btn_is_retry;
+	bool          m_is_hosting;
 
 	std::vector<int> m_playerids;