Merge pull request #8853 from CrunchBite/feature-xlink-kai-bba

Feature XLink Kai BBA

Source/Core/Core/CMakeLists.txt

@@ -592,8 +592,9 @@ endif()
 
 if(WIN32)
   target_sources(core PRIVATE
-    HW/EXI/BBA-TAP/TAP_Win32.cpp
+    HW/EXI/BBA/TAP_Win32.cpp
-    HW/EXI/BBA-TAP/TAP_Win32.h
+    HW/EXI/BBA/TAP_Win32.h
+    HW/EXI/BBA/XLINK_KAI_BBA.cpp
     HW/WiimoteReal/IOWin.cpp
     HW/WiimoteReal/IOWin.h
   )
@@ -606,7 +607,8 @@ if(WIN32)
   target_compile_definitions(core PRIVATE "-D_WINSOCK_DEPRECATED_NO_WARNINGS")
 elseif(APPLE)
   target_sources(core PRIVATE
-    HW/EXI/BBA-TAP/TAP_Apple.cpp
+    HW/EXI/BBA/TAP_Apple.cpp
+    HW/EXI/BBA/XLINK_KAI_BBA.cpp
     HW/WiimoteReal/IOdarwin.h
     HW/WiimoteReal/IOdarwin_private.h
     HW/WiimoteReal/IOdarwin.mm
@@ -614,7 +616,8 @@ elseif(APPLE)
   target_link_libraries(core PUBLIC ${IOB_LIBRARY})
 elseif(UNIX)
   target_sources(core PRIVATE
-    HW/EXI/BBA-TAP/TAP_Unix.cpp
+    HW/EXI/BBA/TAP_Unix.cpp
+    HW/EXI/BBA/XLINK_KAI_BBA.cpp
   )
   if(ANDROID)
     target_sources(core PRIVATE

Source/Core/Core/ConfigManager.cpp

@@ -227,6 +227,8 @@ void SConfig::SaveCoreSettings(IniFile& ini)
   core->Set("SlotB", m_EXIDevice[1]);
   core->Set("SerialPort1", m_EXIDevice[2]);
   core->Set("BBA_MAC", m_bba_mac);
+  core->Set("BBA_XLINK_IP", m_bba_xlink_ip);
+  core->Set("BBA_XLINK_CHAT_OSD", m_bba_xlink_chat_osd);
   for (int i = 0; i < SerialInterface::MAX_SI_CHANNELS; ++i)
   {
     core->Set(fmt::format("SIDevice{}", i), m_SIDevice[i]);
@@ -495,6 +497,8 @@ void SConfig::LoadCoreSettings(IniFile& ini)
   core->Get("SlotB", (int*)&m_EXIDevice[1], ExpansionInterface::EXIDEVICE_NONE);
   core->Get("SerialPort1", (int*)&m_EXIDevice[2], ExpansionInterface::EXIDEVICE_NONE);
   core->Get("BBA_MAC", &m_bba_mac);
+  core->Get("BBA_XLINK_IP", &m_bba_xlink_ip, "127.0.0.1");
+  core->Get("BBA_XLINK_CHAT_OSD", &m_bba_xlink_chat_osd, true);
   for (size_t i = 0; i < std::size(m_SIDevice); ++i)
   {
     core->Get(fmt::format("SIDevice{}", i), &m_SIDevice[i],

Source/Core/Core/ConfigManager.h

@@ -226,7 +226,10 @@ struct SConfig
   std::string m_strGbaCartB;
   ExpansionInterface::TEXIDevices m_EXIDevice[3];
   SerialInterface::SIDevices m_SIDevice[4];
+
   std::string m_bba_mac;
+  std::string m_bba_xlink_ip;
+  bool m_bba_xlink_chat_osd = true;
 
   // interface language
   std::string m_InterfaceLanguage;

Source/Core/Core/Core.vcxproj

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|ARM64">
@@ -140,7 +140,8 @@
     <ClCompile Include="HW\DVD\DVDMath.cpp" />
     <ClCompile Include="HW\DVD\DVDThread.cpp" />
     <ClCompile Include="HW\DVD\FileMonitor.cpp" />
-    <ClCompile Include="HW\EXI\BBA-TAP\TAP_Win32.cpp" />
+    <ClCompile Include="HW\EXI\BBA\TAP_Win32.cpp" />
+    <ClCompile Include="HW\EXI\BBA\XLINK_KAI_BBA.cpp" />
     <ClCompile Include="HW\EXI\EXI.cpp" />
     <ClCompile Include="HW\EXI\EXI_Channel.cpp" />
     <ClCompile Include="HW\EXI\EXI_Device.cpp" />
@@ -498,7 +499,7 @@
     <ClInclude Include="HW\DVD\DVDMath.h" />
     <ClInclude Include="HW\DVD\DVDThread.h" />
     <ClInclude Include="HW\DVD\FileMonitor.h" />
-    <ClInclude Include="HW\EXI\BBA-TAP\TAP_Win32.h" />
+    <ClInclude Include="HW\EXI\BBA\TAP_Win32.h" />
     <ClInclude Include="HW\EXI\EXI.h" />
     <ClInclude Include="HW\EXI\EXI_Channel.h" />
     <ClInclude Include="HW\EXI\EXI_Device.h" />

Source/Core/Core/Core.vcxproj.filters

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup>
     <Filter Include="ActionReplay">
@@ -993,6 +993,12 @@
     <ClCompile Include="PowerPC\Jit64\RegCache\FPURegCache.cpp">
       <Filter>PowerPC\Jit64</Filter>
     </ClCompile>
+    <ClCompile Include="HW\EXI\BBA\XLINK_KAI_BBA.cpp">
+      <Filter>HW %28Flipper/Hollywood%29\EXI - Expansion Interface\BBA</Filter>
+    </ClCompile>
+    <ClCompile Include="HW\EXI\BBA\TAP_Win32.cpp">
+      <Filter>HW %28Flipper/Hollywood%29\EXI - Expansion Interface\BBA</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="BootManager.h" />
@@ -1743,6 +1749,9 @@
     <ClInclude Include="PowerPC\JitArmCommon\BackPatch.h">
       <Filter>PowerPC\JitArmCommon</Filter>
     </ClInclude>
+    <ClInclude Include="HW\EXI\BBA\TAP_Win32.h">
+      <Filter>HW %28Flipper/Hollywood%29\EXI - Expansion Interface\BBA</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <Text Include="CMakeLists.txt" />

Source/Core/Core/HW/EXI/BBA/TAP_Apple.cpp

@@ -12,7 +12,7 @@
 
 namespace ExpansionInterface
 {
-bool CEXIETHERNET::Activate()
+bool CEXIETHERNET::TAPNetworkInterface::Activate()
 {
   if (IsActivated())
     return true;
@@ -30,7 +30,7 @@ bool CEXIETHERNET::Activate()
   return RecvInit();
 }
 
-void CEXIETHERNET::Deactivate()
+void CEXIETHERNET::TAPNetworkInterface::Deactivate()
 {
   close(fd);
   fd = -1;
@@ -41,12 +41,12 @@ void CEXIETHERNET::Deactivate()
     readThread.join();
 }
 
-bool CEXIETHERNET::IsActivated()
+bool CEXIETHERNET::TAPNetworkInterface::IsActivated()
 {
   return fd != -1;
 }
 
-bool CEXIETHERNET::SendFrame(const u8* frame, u32 size)
+bool CEXIETHERNET::TAPNetworkInterface::SendFrame(const u8* frame, u32 size)
 {
   INFO_LOG(SP1, "SendFrame %x\n%s", size, ArrayToString(frame, size, 0x10).c_str());
 
@@ -58,12 +58,12 @@ bool CEXIETHERNET::SendFrame(const u8* frame, u32 size)
   }
   else
   {
-    SendComplete();
+    m_eth_ref->SendComplete();
     return true;
   }
 }
 
-void CEXIETHERNET::ReadThreadHandler(CEXIETHERNET* self)
+void CEXIETHERNET::TAPNetworkInterface::ReadThreadHandler(TAPNetworkInterface* self)
 {
   while (!self->readThreadShutdown.IsSet())
   {
@@ -77,7 +77,7 @@ void CEXIETHERNET::ReadThreadHandler(CEXIETHERNET* self)
     if (select(self->fd + 1, &rfds, nullptr, nullptr, &timeout) <= 0)
       continue;
 
-    int readBytes = read(self->fd, self->mRecvBuffer.get(), BBA_RECV_SIZE);
+    int readBytes = read(self->fd, self->m_eth_ref->mRecvBuffer.get(), BBA_RECV_SIZE);
     if (readBytes < 0)
     {
       ERROR_LOG(SP1, "Failed to read from BBA, err=%d", readBytes);
@@ -85,25 +85,25 @@ void CEXIETHERNET::ReadThreadHandler(CEXIETHERNET* self)
     else if (self->readEnabled.IsSet())
     {
       INFO_LOG(SP1, "Read data: %s",
-               ArrayToString(self->mRecvBuffer.get(), readBytes, 0x10).c_str());
+               ArrayToString(self->m_eth_ref->mRecvBuffer.get(), readBytes, 0x10).c_str());
-      self->mRecvBufferLength = readBytes;
+      self->m_eth_ref->mRecvBufferLength = readBytes;
-      self->RecvHandlePacket();
+      self->m_eth_ref->RecvHandlePacket();
     }
   }
 }
 
-bool CEXIETHERNET::RecvInit()
+bool CEXIETHERNET::TAPNetworkInterface::RecvInit()
 {
   readThread = std::thread(ReadThreadHandler, this);
   return true;
 }
 
-void CEXIETHERNET::RecvStart()
+void CEXIETHERNET::TAPNetworkInterface::RecvStart()
 {
   readEnabled.Set();
 }
 
-void CEXIETHERNET::RecvStop()
+void CEXIETHERNET::TAPNetworkInterface::RecvStop()
 {
   readEnabled.Clear();
 }

Source/Core/Core/HW/EXI/BBA/TAP_Unix.cpp

@@ -28,7 +28,7 @@ namespace ExpansionInterface
 #define NOTIMPLEMENTED(Name)                                                                       \
   NOTICE_LOG(SP1, "CEXIETHERNET::%s not implemented for your UNIX", Name);
 
-bool CEXIETHERNET::Activate()
+bool CEXIETHERNET::TAPNetworkInterface::Activate()
 {
 #ifdef __linux__
   if (IsActivated())
@@ -50,7 +50,7 @@ bool CEXIETHERNET::Activate()
   const int MAX_INTERFACES = 32;
   for (int i = 0; i < MAX_INTERFACES; ++i)
   {
-    strncpy(ifr.ifr_name, StringFromFormat("Dolphin%d", i).c_str(), IFNAMSIZ - 1);
+    strncpy(ifr.ifr_name, StringFromFormat("Dolphin%d", i).c_str(), IFNAMSIZ);
 
     int err;
     if ((err = ioctl(fd, TUNSETIFF, (void*)&ifr)) < 0)
@@ -78,7 +78,7 @@ bool CEXIETHERNET::Activate()
 #endif
 }
 
-void CEXIETHERNET::Deactivate()
+void CEXIETHERNET::TAPNetworkInterface::Deactivate()
 {
 #ifdef __linux__
   close(fd);
@@ -93,7 +93,7 @@ void CEXIETHERNET::Deactivate()
 #endif
 }
 
-bool CEXIETHERNET::IsActivated()
+bool CEXIETHERNET::TAPNetworkInterface::IsActivated()
 {
 #ifdef __linux__
   return fd != -1 ? true : false;
@@ -102,7 +102,7 @@ bool CEXIETHERNET::IsActivated()
 #endif
 }
 
-bool CEXIETHERNET::SendFrame(const u8* frame, u32 size)
+bool CEXIETHERNET::TAPNetworkInterface::SendFrame(const u8* frame, u32 size)
 {
 #ifdef __linux__
   DEBUG_LOG(SP1, "SendFrame %x\n%s", size, ArrayToString(frame, size, 0x10).c_str());
@@ -115,7 +115,7 @@ bool CEXIETHERNET::SendFrame(const u8* frame, u32 size)
   }
   else
   {
-    SendComplete();
+    m_eth_ref->SendComplete();
     return true;
   }
 #else
@@ -125,7 +125,7 @@ bool CEXIETHERNET::SendFrame(const u8* frame, u32 size)
 }
 
 #ifdef __linux__
-void CEXIETHERNET::ReadThreadHandler(CEXIETHERNET* self)
+void CEXIETHERNET::TAPNetworkInterface::ReadThreadHandler(TAPNetworkInterface* self)
 {
   while (!self->readThreadShutdown.IsSet())
   {
@@ -139,7 +139,7 @@ void CEXIETHERNET::ReadThreadHandler(CEXIETHERNET* self)
     if (select(self->fd + 1, &rfds, nullptr, nullptr, &timeout) <= 0)
       continue;
 
-    int readBytes = read(self->fd, self->mRecvBuffer.get(), BBA_RECV_SIZE);
+    int readBytes = read(self->fd, self->m_eth_ref->mRecvBuffer.get(), BBA_RECV_SIZE);
     if (readBytes < 0)
     {
       ERROR_LOG(SP1, "Failed to read from BBA, err=%d", readBytes);
@@ -147,15 +147,15 @@ void CEXIETHERNET::ReadThreadHandler(CEXIETHERNET* self)
     else if (self->readEnabled.IsSet())
     {
       DEBUG_LOG(SP1, "Read data: %s",
-                ArrayToString(self->mRecvBuffer.get(), readBytes, 0x10).c_str());
+                ArrayToString(self->m_eth_ref->mRecvBuffer.get(), readBytes, 0x10).c_str());
-      self->mRecvBufferLength = readBytes;
+      self->m_eth_ref->mRecvBufferLength = readBytes;
-      self->RecvHandlePacket();
+      self->m_eth_ref->RecvHandlePacket();
     }
   }
 }
 #endif
 
-bool CEXIETHERNET::RecvInit()
+bool CEXIETHERNET::TAPNetworkInterface::RecvInit()
 {
 #ifdef __linux__
   readThread = std::thread(ReadThreadHandler, this);
@@ -166,7 +166,7 @@ bool CEXIETHERNET::RecvInit()
 #endif
 }
 
-void CEXIETHERNET::RecvStart()
+void CEXIETHERNET::TAPNetworkInterface::RecvStart()
 {
 #ifdef __linux__
   readEnabled.Set();
@@ -175,7 +175,7 @@ void CEXIETHERNET::RecvStart()
 #endif
 }
 
-void CEXIETHERNET::RecvStop()
+void CEXIETHERNET::TAPNetworkInterface::RecvStop()
 {
 #ifdef __linux__
   readEnabled.Clear();

Source/Core/Core/HW/EXI/BBA/TAP_Win32.cpp

@@ -2,7 +2,7 @@
 // Licensed under GPLv2+
 // Refer to the license.txt file included.
 
-#include "Core/HW/EXI/BBA-TAP/TAP_Win32.h"
+#include "Core/HW/EXI/BBA/TAP_Win32.h"
 #include "Common/Assert.h"
 #include "Common/Logging/Log.h"
 #include "Common/MsgHandler.h"
@@ -167,7 +167,7 @@ bool OpenTAP(HANDLE& adapter, const std::basic_string<TCHAR>& device_guid)
 
 namespace ExpansionInterface
 {
-bool CEXIETHERNET::Activate()
+bool CEXIETHERNET::TAPNetworkInterface::Activate()
 {
   if (IsActivated())
     return true;
@@ -233,7 +233,7 @@ bool CEXIETHERNET::Activate()
   return RecvInit();
 }
 
-void CEXIETHERNET::Deactivate()
+void CEXIETHERNET::TAPNetworkInterface::Deactivate()
 {
   if (!IsActivated())
     return;
@@ -258,19 +258,19 @@ void CEXIETHERNET::Deactivate()
   memset(&mWriteOverlapped, 0, sizeof(mWriteOverlapped));
 }
 
-bool CEXIETHERNET::IsActivated()
+bool CEXIETHERNET::TAPNetworkInterface::IsActivated()
 {
   return mHAdapter != INVALID_HANDLE_VALUE;
 }
 
-void CEXIETHERNET::ReadThreadHandler(CEXIETHERNET* self)
+void CEXIETHERNET::TAPNetworkInterface::ReadThreadHandler(TAPNetworkInterface* self)
 {
   while (!self->readThreadShutdown.IsSet())
   {
     DWORD transferred;
 
     // Read from TAP into internal buffer.
-    if (ReadFile(self->mHAdapter, self->mRecvBuffer.get(), BBA_RECV_SIZE, &transferred,
+    if (ReadFile(self->mHAdapter, self->m_eth_ref->mRecvBuffer.get(), BBA_RECV_SIZE, &transferred,
                  &self->mReadOverlapped))
     {
       // Returning immediately is not likely to happen, but if so, reset the event state manually.
@@ -300,16 +300,16 @@ void CEXIETHERNET::ReadThreadHandler(CEXIETHERNET* self)
 
     // Copy to BBA buffer, and fire interrupt if enabled.
     DEBUG_LOG(SP1, "Received %u bytes:\n %s", transferred,
-              ArrayToString(self->mRecvBuffer.get(), transferred, 0x10).c_str());
+              ArrayToString(self->m_eth_ref->mRecvBuffer.get(), transferred, 0x10).c_str());
     if (self->readEnabled.IsSet())
     {
-      self->mRecvBufferLength = transferred;
+      self->m_eth_ref->mRecvBufferLength = transferred;
-      self->RecvHandlePacket();
+      self->m_eth_ref->RecvHandlePacket();
     }
   }
 }
 
-bool CEXIETHERNET::SendFrame(const u8* frame, u32 size)
+bool CEXIETHERNET::TAPNetworkInterface::SendFrame(const u8* frame, u32 size)
 {
   DEBUG_LOG(SP1, "SendFrame %u bytes:\n%s", size, ArrayToString(frame, size, 0x10).c_str());
 
@@ -345,22 +345,22 @@ bool CEXIETHERNET::SendFrame(const u8* frame, u32 size)
   }
 
   // Always report the packet as being sent successfully, even though it might be a lie
-  SendComplete();
+  m_eth_ref->SendComplete();
   return true;
 }
 
-bool CEXIETHERNET::RecvInit()
+bool CEXIETHERNET::TAPNetworkInterface::RecvInit()
 {
   readThread = std::thread(ReadThreadHandler, this);
   return true;
 }
 
-void CEXIETHERNET::RecvStart()
+void CEXIETHERNET::TAPNetworkInterface::RecvStart()
 {
   readEnabled.Set();
 }
 
-void CEXIETHERNET::RecvStop()
+void CEXIETHERNET::TAPNetworkInterface::RecvStop()
 {
   readEnabled.Clear();
 }

Source/Core/Core/HW/EXI/BBA/XLINK_KAI_BBA.cpp

@@ -0,0 +1,306 @@
+// Copyright 2008 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "Common/Assert.h"
+#include "Common/Logging/Log.h"
+#include "Common/MsgHandler.h"
+#include "Common/StringUtil.h"
+#include "Core/HW/EXI/EXI_Device.h"
+#include "Core/HW/EXI/EXI_DeviceEthernet.h"
+
+#include "VideoCommon/OnScreenDisplay.h"
+
+#include <SFML/Network.hpp>
+
+#include <cstring>
+
+// BBA implementation with UDP interface to XLink Kai PC/MAC/RaspberryPi client
+// For more information please see: https://www.teamxlink.co.uk/wiki/Emulator_Integration_Protocol
+// Still have questions? Please email crunchbite@teamxlink.co.uk
+// When editing this file please maintain proper capitalization of "XLink Kai"
+
+namespace ExpansionInterface
+{
+bool CEXIETHERNET::XLinkNetworkInterface::Activate()
+{
+  if (IsActivated())
+    return true;
+
+  if (m_sf_socket.bind(sf::Socket::AnyPort) != sf::Socket::Done)
+  {
+    ERROR_LOG(SP1, "Couldn't open XLink Kai UDP socket, unable to initialize BBA");
+    return false;
+  }
+
+  m_sf_recipient_ip = m_dest_ip.c_str();
+
+  // Send connect command with unique local name
+  // connect;locally_unique_name;emulator_name;optional_padding
+  u8 buffer[255] = {};
+  std::string cmd =
+      "connect;" + m_client_identifier + ";dolphin;000000000000000000000000000000000000000000";
+
+  const auto size = u32(cmd.length());
+  memmove(buffer, cmd.c_str(), size);
+
+  DEBUG_LOG(SP1, "SendCommandPayload %x\n%s", size, ArrayToString(buffer, size, 0x10).c_str());
+
+  if (m_sf_socket.send(buffer, size, m_sf_recipient_ip, m_dest_port) != sf::Socket::Done)
+  {
+    ERROR_LOG(SP1, "Activate(): failed to send connect message to XLink Kai client");
+  }
+
+  INFO_LOG(SP1, "BBA initialized.");
+
+  return RecvInit();
+}
+
+void CEXIETHERNET::XLinkNetworkInterface::Deactivate()
+{
+  // Send d; to tell XLink we want to disconnect cleanly
+  // disconnect;optional_locally_unique_name;optional_padding
+  std::string cmd =
+      "disconnect;" + m_client_identifier + ";0000000000000000000000000000000000000000000";
+  const auto size = u32(cmd.length());
+  u8 buffer[255] = {};
+  memmove(buffer, cmd.c_str(), size);
+
+  DEBUG_LOG(SP1, "SendCommandPayload %x\n%s", size, ArrayToString(buffer, size, 0x10).c_str());
+
+  if (m_sf_socket.send(buffer, size, m_sf_recipient_ip, m_dest_port) != sf::Socket::Done)
+  {
+    ERROR_LOG(SP1, "Deactivate(): failed to send disconnect message to XLink Kai client");
+  }
+
+  NOTICE_LOG(SP1, "XLink Kai BBA deactivated");
+
+  m_bba_link_up = false;
+
+  // Disable socket blocking
+  m_sf_socket.setBlocking(false);
+
+  // Set flags for clean shutdown of the read thread
+  m_read_enabled.Clear();
+  m_read_thread_shutdown.Set();
+
+  // Detach the thread and let it die on its own (leaks ~9kb of memory)
+  m_read_thread.detach();
+
+  // Close the socket
+  m_sf_socket.unbind();
+}
+
+bool CEXIETHERNET::XLinkNetworkInterface::IsActivated()
+{
+  return m_sf_socket.getLocalPort() > 0;
+}
+
+bool CEXIETHERNET::XLinkNetworkInterface::SendFrame(const u8* frame, u32 size)
+{
+  // Is the BBA actually connected?
+  if (!m_bba_link_up)
+  {
+    // Has the user been told the connection failed?
+    if (!m_bba_failure_notified)
+    {
+      OSD::AddMessage("XLink Kai BBA not connected", 30000);
+      m_bba_failure_notified = true;
+    }
+
+    // Return true because this isnt an error dolphin needs to handle
+    return true;
+  }
+
+  // Overwrite buffer and add header
+  memmove(m_out_frame, "e;e;", 4);
+  memmove(m_out_frame + 4, frame, size);
+  size += 4;
+
+  // Only uncomment for debugging, the performance hit is too big otherwise
+  // INFO_LOG(SP1, "SendFrame %x\n%s", size, ArrayToString(m_out_frame, size, 0x10).c_str());
+
+  if (m_sf_socket.send(m_out_frame, size, m_sf_recipient_ip, m_dest_port) != sf::Socket::Done)
+  {
+    ERROR_LOG(SP1, "SendFrame(): expected to write %u bytes, but failed, errno %d", size, errno);
+    return false;
+  }
+  else
+  {
+    m_eth_ref->SendComplete();
+    return true;
+  }
+}
+
+void CEXIETHERNET::XLinkNetworkInterface::ReadThreadHandler(
+    CEXIETHERNET::XLinkNetworkInterface* self)
+{
+  sf::IpAddress sender;
+  u16 port;
+
+  while (!self->m_read_thread_shutdown.IsSet())
+  {
+    if (!self->IsActivated())
+      break;
+
+    // XLink supports jumboframes but Gamecube BBA does not. We need to support jumbo frames
+    // *here* because XLink *could* send one
+    std::size_t bytes_read = 0;
+    if (self->m_sf_socket.receive(self->m_in_frame, std::size(self->m_in_frame), bytes_read, sender,
+                                  port) != sf::Socket::Done &&
+        self->m_bba_link_up)
+    {
+      ERROR_LOG(SP1, "Failed to read from BBA, err=%zu", bytes_read);
+    }
+
+    // Make sure *anything* was recieved before going any further
+    if (bytes_read < 1)
+      continue;
+
+    // Did we get an ethernet frame? Copy the first 4 bytes to check the header
+    char temp_check[4];
+    memmove(temp_check, self->m_in_frame, std::size(temp_check));
+
+    // Check for e;e; header; this indicates the received data is an ethernet frame
+    // e;e;raw_ethernet_frame_data
+    if (temp_check[2] == 'e' && temp_check[3] == ';')
+    {
+      // Is the frame larger than BBA_RECV_SIZE?
+      if ((bytes_read - 4) < BBA_RECV_SIZE)
+      {
+        // Copy payload into BBA buffer as an ethernet frame
+        memmove(self->m_eth_ref->mRecvBuffer.get(), self->m_in_frame + 4, bytes_read - 4);
+
+        // Check the frame size again after the header is removed
+        if (bytes_read < 1)
+        {
+          ERROR_LOG(SP1, "Failed to read from BBA, err=%zu", bytes_read - 4);
+        }
+        else if (self->m_read_enabled.IsSet())
+        {
+          // Only uncomment for debugging, the performance hit is too big otherwise
+          // DEBUG_LOG(SP1, "Read data: %s", ArrayToString(self->m_eth_ref->mRecvBuffer.get(),
+          // u32(bytes_read - 4), 0x10).c_str());
+          self->m_eth_ref->mRecvBufferLength = u32(bytes_read - 4);
+          self->m_eth_ref->RecvHandlePacket();
+        }
+      }
+    }
+    // Otherwise we recieved control data or junk
+    else
+    {
+      std::string control_msg(self->m_in_frame, self->m_in_frame + bytes_read);
+      INFO_LOG(SP1, "Received XLink Kai control data: %s", control_msg.c_str());
+
+      // connected;identifier;
+      if (StringBeginsWith(control_msg, "connected"))
+      {
+        NOTICE_LOG(SP1, "XLink Kai BBA connected");
+        OSD::AddMessage("XLink Kai BBA connected", 4500);
+
+        self->m_bba_link_up = true;
+        // TODO (in EXI_DeviceEthernet.cpp) bring the BBA link up here
+
+        // Send any extra settings now
+        // Enable XLink chat messages in OSD if set
+        if (self->m_chat_osd_enabled)
+        {
+          constexpr std::string_view cmd = "setting;chat;true;";
+          const auto size = u32(cmd.length());
+          u8 buffer[255] = {};
+          memmove(buffer, cmd.data(), size);
+
+          DEBUG_LOG(SP1, "SendCommandPayload %x\n%s", size,
+                    ArrayToString(buffer, size, 0x10).c_str());
+
+          if (self->m_sf_socket.send(buffer, size, self->m_sf_recipient_ip, self->m_dest_port) !=
+              sf::Socket::Done)
+          {
+            ERROR_LOG(SP1,
+                      "ReadThreadHandler(): failed to send setting message to XLink Kai client");
+          }
+        }
+      }
+      // disconnected;optional_identifier;optional_message;
+      else if (StringBeginsWith(control_msg, "disconnected"))
+      {
+        NOTICE_LOG(SP1, "XLink Kai BBA disconnected");
+        // Show OSD message for 15 seconds to make sure the user sees it
+        OSD::AddMessage("XLink Kai BBA disconnected", 15000);
+
+        // TODO (TODO in EXI_DeviceEthernet.cpp) bring the BBA link down here
+        self->m_bba_link_up = false;
+
+        // Disable socket blocking
+        self->m_sf_socket.setBlocking(false);
+
+        // Shut down the read thread
+        self->m_read_enabled.Clear();
+        self->m_read_thread_shutdown.Set();
+
+        // Close the socket
+        self->m_sf_socket.unbind();
+        break;
+      }
+      // keepalive;
+      else if (StringBeginsWith(control_msg, "keepalive"))
+      {
+        DEBUG_LOG(SP1, "XLink Kai BBA keepalive");
+
+        // Only uncomment for debugging, just clogs the log otherwise
+        // INFO_LOG(SP1, "SendCommandPayload %x\n%s", 2, ArrayToString(m_in_frame, 2,
+        // 0x10).c_str());
+
+        // Reply (using the message that came in!)
+        if (self->m_sf_socket.send(self->m_in_frame, 10, self->m_sf_recipient_ip,
+                                   self->m_dest_port) != sf::Socket::Done)
+        {
+          ERROR_LOG(SP1, "ReadThreadHandler(): failed to reply to XLink Kai client keepalive");
+        }
+      }
+      // message;message_text;
+      else if (StringBeginsWith(control_msg, "message"))
+      {
+        std::string msg = control_msg.substr(8, control_msg.length() - 1);
+
+        NOTICE_LOG(SP1, "XLink Kai message: %s", msg.c_str());
+        // Show OSD message for 15 seconds to make sure the user sees it
+        OSD::AddMessage(std::move(msg), 15000);
+      }
+      // chat;message_text;
+      else if (StringBeginsWith(control_msg, "chat"))
+      {
+        std::string msg = control_msg.substr(5, control_msg.length() - 1);
+
+        NOTICE_LOG(SP1, "XLink Kai chat: %s", msg.c_str());
+        OSD::AddMessage(std::move(msg), 5000);
+      }
+      // directmessage;message_text;
+      else if (StringBeginsWith(control_msg, "directmessage"))
+      {
+        std::string msg = control_msg.substr(14, control_msg.length() - 1);
+
+        NOTICE_LOG(SP1, "XLink Kai direct message: %s", msg.c_str());
+        OSD::AddMessage(std::move(msg), 5000);
+      }
+      // else junk/unsupported control message
+    }
+  }
+}
+
+bool CEXIETHERNET::XLinkNetworkInterface::RecvInit()
+{
+  m_read_thread = std::thread(ReadThreadHandler, this);
+  return true;
+}
+
+void CEXIETHERNET::XLinkNetworkInterface::RecvStart()
+{
+  m_read_enabled.Set();
+}
+
+void CEXIETHERNET::XLinkNetworkInterface::RecvStop()
+{
+  m_read_enabled.Clear();
+}
+}  // namespace ExpansionInterface

Source/Core/Core/HW/EXI/EXI_Device.cpp

@@ -133,7 +133,11 @@ std::unique_ptr<IEXIDevice> EXIDevice_Create(const TEXIDevices device_type, cons
     break;
 
   case EXIDEVICE_ETH:
-    result = std::make_unique<CEXIETHERNET>();
+    result = std::make_unique<CEXIETHERNET>(BBADeviceType::TAP);
+    break;
+
+  case EXIDEVICE_ETHXLINK:
+    result = std::make_unique<CEXIETHERNET>(BBADeviceType::XLINK);
     break;
 
   case EXIDEVICE_GECKO:

Source/Core/Core/HW/EXI/EXI_Device.h

@@ -32,6 +32,7 @@ enum TEXIDevices : int
   // Converted to EXIDEVICE_MEMORYCARD internally.
   EXIDEVICE_MEMORYCARDFOLDER,
   EXIDEVICE_AGP,
+  EXIDEVICE_ETHXLINK,
   EXIDEVICE_NONE = 0xFF
 };
 

Source/Core/Core/HW/EXI/EXI_DeviceEthernet.cpp

@@ -4,6 +4,7 @@
 
 #include "Core/HW/EXI/EXI_DeviceEthernet.h"
 
+#include <algorithm>
 #include <memory>
 #include <optional>
 #include <string>
@@ -12,6 +13,7 @@
 #include "Common/CommonTypes.h"
 #include "Common/Logging/Log.h"
 #include "Common/Network.h"
+#include "Common/StringUtil.h"
 #include "Core/ConfigManager.h"
 #include "Core/CoreTiming.h"
 #include "Core/HW/EXI/EXI.h"
@@ -23,19 +25,16 @@ namespace ExpansionInterface
 // Multiple parts of this implementation depend on Dolphin
 // being compiled for a little endian host.
 
-CEXIETHERNET::CEXIETHERNET()
+CEXIETHERNET::CEXIETHERNET(BBADeviceType type)
 {
-  tx_fifo = std::make_unique<u8[]>(BBA_TXFIFO_SIZE);
-  mBbaMem = std::make_unique<u8[]>(BBA_MEM_SIZE);
-  mRecvBuffer = std::make_unique<u8[]>(BBA_RECV_SIZE);
-
-  MXHardReset();
-
   // Parse MAC address from config, and generate a new one if it doesn't
   // exist or can't be parsed.
   std::string& mac_addr_setting = SConfig::GetInstance().m_bba_mac;
   std::optional<Common::MACAddress> mac_addr = Common::StringToMacAddress(mac_addr_setting);
 
+  std::transform(mac_addr_setting.begin(), mac_addr_setting.end(), mac_addr_setting.begin(),
+                 [](unsigned char c) { return std::tolower(c); });
+
   if (!mac_addr)
   {
     mac_addr = Common::GenerateMacAddress(Common::MACConsumer::BBA);
@@ -43,6 +42,42 @@ CEXIETHERNET::CEXIETHERNET()
     SConfig::GetInstance().SaveSettings();
   }
 
+  switch (type)
+  {
+  case BBADeviceType::TAP:
+    m_network_interface = std::make_unique<TAPNetworkInterface>(this);
+    INFO_LOG(SP1, "Created TAP physical network interface.");
+    break;
+  case BBADeviceType::XLINK:
+    // TODO start BBA with network link down, bring it up after "connected" response from XLink
+
+    // Perform sanity check on BBA MAC address, XLink requires the vendor OUI to be Nintendo's and
+    // to be one of the two used for the GameCube.
+    // Don't actually stop the BBA from initializing though
+    if (!StringBeginsWith(mac_addr_setting, "00:09:bf") &&
+        !StringBeginsWith(mac_addr_setting, "00:17:ab"))
+    {
+      PanicAlertT("BBA MAC address %s invalid for XLink Kai. A valid Nintendo GameCube MAC address "
+                  "must be used. Generate a new MAC address starting with 00:09:bf or 00:17:ab.",
+                  mac_addr_setting.c_str());
+    }
+
+    // m_client_mdentifier should be unique per connected emulator from the XLink kai client's
+    // perspective so lets use "dolphin<bba mac>"
+    m_network_interface = std::make_unique<XLinkNetworkInterface>(
+        this, SConfig::GetInstance().m_bba_xlink_ip, 34523,
+        "dolphin" + SConfig::GetInstance().m_bba_mac, SConfig::GetInstance().m_bba_xlink_chat_osd);
+    INFO_LOG(SP1, "Created XLink Kai BBA network interface connection to %s:34523",
+             SConfig::GetInstance().m_bba_xlink_ip.c_str());
+    break;
+  }
+
+  tx_fifo = std::make_unique<u8[]>(BBA_TXFIFO_SIZE);
+  mBbaMem = std::make_unique<u8[]>(BBA_MEM_SIZE);
+  mRecvBuffer = std::make_unique<u8[]>(BBA_RECV_SIZE);
+
+  MXHardReset();
+
   const auto& mac = mac_addr.value();
   memcpy(&mBbaMem[BBA_NAFR_PAR0], mac.data(), mac.size());
 
@@ -52,7 +87,7 @@ CEXIETHERNET::CEXIETHERNET()
 
 CEXIETHERNET::~CEXIETHERNET()
 {
-  Deactivate();
+  m_network_interface->Deactivate();
 }
 
 void CEXIETHERNET::SetCS(int cs)
@@ -303,7 +338,7 @@ void CEXIETHERNET::MXCommandHandler(u32 data, u32 size)
     {
       INFO_LOG(SP1, "Software reset");
       // MXSoftReset();
-      Activate();
+      m_network_interface->Activate();
     }
 
     if ((mBbaMem[BBA_NCRA] & NCRA_SR) ^ (data & NCRA_SR))
@@ -311,9 +346,9 @@ void CEXIETHERNET::MXCommandHandler(u32 data, u32 size)
       DEBUG_LOG(SP1, "%s rx", (data & NCRA_SR) ? "start" : "stop");
 
       if (data & NCRA_SR)
-        RecvStart();
+        m_network_interface->RecvStart();
       else
-        RecvStop();
+        m_network_interface->RecvStop();
     }
 
     // Only start transfer if there isn't one currently running
@@ -386,7 +421,7 @@ void CEXIETHERNET::DirectFIFOWrite(const u8* data, u32 size)
 
 void CEXIETHERNET::SendFromDirectFIFO()
 {
-  SendFrame(tx_fifo.get(), *(u16*)&mBbaMem[BBA_TXFIFOCNT]);
+  m_network_interface->SendFrame(tx_fifo.get(), *(u16*)&mBbaMem[BBA_TXFIFOCNT]);
 }
 
 void CEXIETHERNET::SendFromPacketBuffer()
@@ -579,7 +614,7 @@ bool CEXIETHERNET::RecvHandlePacket()
 
 wait_for_next:
   if (mBbaMem[BBA_NCRA] & NCRA_SR)
-    RecvStart();
+    m_network_interface->RecvStart();
 
   return true;
 }

Source/Core/Core/HW/EXI/EXI_DeviceEthernet.h

@@ -12,6 +12,8 @@
 #include <Windows.h>
 #endif
 
+#include <SFML/Network.hpp>
+
 #include "Common/Flag.h"
 #include "Core/HW/EXI/EXI_Device.h"
 
@@ -196,10 +198,16 @@ enum RecvStatus
 
 #define BBA_RECV_SIZE 0x800
 
+enum class BBADeviceType
+{
+  TAP,
+  XLINK,
+};
+
 class CEXIETHERNET : public IEXIDevice
 {
 public:
-  CEXIETHERNET();
+  explicit CEXIETHERNET(BBADeviceType type);
   virtual ~CEXIETHERNET();
   void SetCS(int cs) override;
   bool IsPresent() const override;
@@ -297,19 +305,46 @@ private:
   std::unique_ptr<u8[]> mBbaMem;
   std::unique_ptr<u8[]> tx_fifo;
 
-  // TAP interface
+  class NetworkInterface
-  static void ReadThreadHandler(CEXIETHERNET* self);
+  {
-  bool Activate();
+  protected:
-  void Deactivate();
+    CEXIETHERNET* m_eth_ref = nullptr;
-  bool IsActivated();
+    explicit NetworkInterface(CEXIETHERNET* eth_ref) : m_eth_ref{eth_ref} {}
-  bool SendFrame(const u8* frame, u32 size);
-  bool RecvInit();
-  void RecvStart();
-  void RecvStop();
 
-  std::unique_ptr<u8[]> mRecvBuffer;
+  public:
-  u32 mRecvBufferLength = 0;
+    virtual bool Activate() { return false; }
+    virtual void Deactivate() {}
+    virtual bool IsActivated() { return false; }
+    virtual bool SendFrame(const u8* frame, u32 size) { return false; }
+    virtual bool RecvInit() { return false; }
+    virtual void RecvStart() {}
+    virtual void RecvStop() {}
 
+    virtual ~NetworkInterface() = default;
+  };
+
+  class TAPNetworkInterface : public NetworkInterface
+  {
+  public:
+    explicit TAPNetworkInterface(CEXIETHERNET* eth_ref) : NetworkInterface(eth_ref) {}
+
+  public:
+    bool Activate() override;
+    void Deactivate() override;
+    bool IsActivated() override;
+    bool SendFrame(const u8* frame, u32 size) override;
+    bool RecvInit() override;
+    void RecvStart() override;
+    void RecvStop() override;
+
+  private:
+#if defined(WIN32) || defined(__linux__) || defined(__APPLE__) || defined(__FreeBSD__) ||          \
+    defined(__OpenBSD__)
+    std::thread readThread;
+    Common::Flag readEnabled;
+    Common::Flag readThreadShutdown;
+    static void ReadThreadHandler(TAPNetworkInterface* self);
+#endif
 #if defined(_WIN32)
     HANDLE mHAdapter = INVALID_HANDLE_VALUE;
     OVERLAPPED mReadOverlapped = {};
@@ -319,12 +354,50 @@ private:
 #elif defined(__linux__) || defined(__APPLE__) || defined(__FreeBSD__) || defined(__OpenBSD__)
     int fd = -1;
 #endif
+  };
 
+  class XLinkNetworkInterface : public NetworkInterface
+  {
+  public:
+    XLinkNetworkInterface(CEXIETHERNET* eth_ref, std::string dest_ip, int dest_port,
+                          std::string identifier, bool chat_osd_enabled)
+        : NetworkInterface(eth_ref), m_dest_ip(std::move(dest_ip)), m_dest_port(dest_port),
+          m_client_identifier(identifier), m_chat_osd_enabled(chat_osd_enabled)
+    {
+    }
+
+  public:
+    bool Activate() override;
+    void Deactivate() override;
+    bool IsActivated() override;
+    bool SendFrame(const u8* frame, u32 size) override;
+    bool RecvInit() override;
+    void RecvStart() override;
+    void RecvStop() override;
+
+  private:
+    std::string m_dest_ip;
+    int m_dest_port;
+    std::string m_client_identifier;
+    bool m_chat_osd_enabled;
+    bool m_bba_link_up = false;
+    bool m_bba_failure_notified = false;
 #if defined(WIN32) || defined(__linux__) || defined(__APPLE__) || defined(__FreeBSD__) ||          \
     defined(__OpenBSD__)
-  std::thread readThread;
+    sf::UdpSocket m_sf_socket;
-  Common::Flag readEnabled;
+    sf::IpAddress m_sf_recipient_ip;
-  Common::Flag readThreadShutdown;
+    char m_in_frame[9004];
+    char m_out_frame[9004];
+    std::thread m_read_thread;
+    Common::Flag m_read_enabled;
+    Common::Flag m_read_thread_shutdown;
+    static void ReadThreadHandler(XLinkNetworkInterface* self);
 #endif
   };
+
+  std::unique_ptr<NetworkInterface> m_network_interface;
+
+  std::unique_ptr<u8[]> mRecvBuffer;
+  u32 mRecvBufferLength = 0;
+};
 }  // namespace ExpansionInterface

Source/Core/DolphinQt/Settings/GameCubePane.cpp

@@ -103,7 +103,9 @@ void GameCubePane::CreateWidgets()
   for (const auto& entry :
        {std::make_pair(tr("<Nothing>"), ExpansionInterface::EXIDEVICE_NONE),
         std::make_pair(tr("Dummy"), ExpansionInterface::EXIDEVICE_DUMMY),
-        std::make_pair(tr("Broadband Adapter"), ExpansionInterface::EXIDEVICE_ETH)})
+        std::make_pair(tr("Broadband Adapter (TAP)"), ExpansionInterface::EXIDEVICE_ETH),
+        std::make_pair(tr("Broadband Adapter (XLink Kai)"),
+                       ExpansionInterface::EXIDEVICE_ETHXLINK)})
   {
     m_slot_combos[2]->addItem(entry.first, entry.second);
   }
@@ -158,7 +160,8 @@ void GameCubePane::UpdateButton(int slot)
          value == ExpansionInterface::EXIDEVICE_AGP || value == ExpansionInterface::EXIDEVICE_MIC);
     break;
   case SLOT_SP1_INDEX:
-    has_config = (value == ExpansionInterface::EXIDEVICE_ETH);
+    has_config = (value == ExpansionInterface::EXIDEVICE_ETH ||
+                  value == ExpansionInterface::EXIDEVICE_ETHXLINK);
     break;
   }
 
@@ -186,12 +189,26 @@ void GameCubePane::OnConfigPressed(int slot)
   {
     bool ok;
     const auto new_mac = QInputDialog::getText(
+        // i18n: MAC stands for Media Access Control. A MAC address uniquely identifies a network
+        // interface (physical) like a serial number. "MAC" should be kept in translations.
         this, tr("Broadband Adapter MAC address"), tr("Enter new Broadband Adapter MAC address:"),
         QLineEdit::Normal, QString::fromStdString(SConfig::GetInstance().m_bba_mac), &ok);
     if (ok)
       SConfig::GetInstance().m_bba_mac = new_mac.toStdString();
     return;
   }
+  case ExpansionInterface::EXIDEVICE_ETHXLINK:
+  {
+    bool ok;
+    const auto new_dest = QInputDialog::getText(
+        this, tr("Broadband Adapter (XLink Kai) Destination Address"),
+        tr("Enter IP address of device running the XLink Kai Client.\nFor more information see"
+           " https://www.teamxlink.co.uk/wiki/Dolphin"),
+        QLineEdit::Normal, QString::fromStdString(SConfig::GetInstance().m_bba_xlink_ip), &ok);
+    if (ok)
+      SConfig::GetInstance().m_bba_xlink_ip = new_dest.toStdString();
+    return;
+  }
   default:
     qFatal("unknown settings pressed");
   }