From 4fea832f49f55e38877fcdb4c4e7092b7c98cb51 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A9o=20Lam?= <leo@leolam.fr>
Date: Sun, 29 Nov 2020 00:58:33 +0100
Subject: [PATCH] IOS/NCD: Implement Lock/Unlock more accurately

NCD returns an error if it receives a request to lock the driver
when it is already locked.

Emulating this may seem pointless, but it turns out PPC-side code
expects NCD to return an error and will immediately fail and stop
initialising wireless stuff if NCD succeeds.
---
 Source/Core/Core/IOS/Network/NCD/Manage.cpp | 48 ++++++++++++++++++++-
 Source/Core/Core/IOS/Network/NCD/Manage.h   |  3 ++
 Source/Core/Core/State.cpp                  |  2 +-
 3 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/Source/Core/Core/IOS/Network/NCD/Manage.cpp b/Source/Core/Core/IOS/Network/NCD/Manage.cpp
index 2fcfb91beb..602a721374 100644
--- a/Source/Core/Core/IOS/Network/NCD/Manage.cpp
+++ b/Source/Core/Core/IOS/Network/NCD/Manage.cpp
@@ -20,6 +20,12 @@ NetNCDManage::NetNCDManage(Kernel& ios, const std::string& device_name) : Device
   config.ReadConfig(ios.GetFS().get());
 }
 
+void NetNCDManage::DoState(PointerWrap& p)
+{
+  Device::DoState(p);
+  p.Do(m_ipc_fd);
+}
+
 IPCCommandResult NetNCDManage::IOCtlV(const IOCtlVRequest& request)
 {
   s32 return_value = IPC_SUCCESS;
@@ -29,11 +35,51 @@ IPCCommandResult NetNCDManage::IOCtlV(const IOCtlVRequest& request)
   switch (request.request)
   {
   case IOCTLV_NCD_LOCKWIRELESSDRIVER:
+    if (!request.HasNumberOfValidVectors(0, 1))
+      return GetDefaultReply(IPC_EINVAL);
+
+    if (request.io_vectors[0].size < 2 * sizeof(u32))
+      return GetDefaultReply(IPC_EINVAL);
+
+    if (m_ipc_fd != 0)
+    {
+      // It is an error to lock the driver again when it is already locked.
+      common_result = IPC_EINVAL;
+    }
+    else
+    {
+      // NCD writes the internal address of the request's file descriptor.
+      // We will just write the value of the file descriptor.
+      // The value will be positive so this will work fine.
+      m_ipc_fd = request.fd;
+      Memory::Write_U32(request.fd, request.io_vectors[0].address + 4);
+    }
     break;
 
   case IOCTLV_NCD_UNLOCKWIRELESSDRIVER:
-    // Memory::Read_U32(request.in_vectors.at(0).address);
+  {
+    if (!request.HasNumberOfValidVectors(1, 1))
+      return GetDefaultReply(IPC_EINVAL);
+
+    if (request.in_vectors[0].size < sizeof(u32))
+      return GetDefaultReply(IPC_EINVAL);
+
+    if (request.io_vectors[0].size < sizeof(u32))
+      return GetDefaultReply(IPC_EINVAL);
+
+    const u32 request_handle = Memory::Read_U32(request.in_vectors[0].address);
+    if (m_ipc_fd == request_handle)
+    {
+      m_ipc_fd = 0;
+      common_result = 0;
+    }
+    else
+    {
+      common_result = -3;
+    }
+
     break;
+  }
 
   case IOCTLV_NCD_GETCONFIG:
     INFO_LOG_FMT(IOS_NET, "NET_NCD_MANAGE: IOCTLV_NCD_GETCONFIG");
diff --git a/Source/Core/Core/IOS/Network/NCD/Manage.h b/Source/Core/Core/IOS/Network/NCD/Manage.h
index 4105bf7408..8da300e719 100644
--- a/Source/Core/Core/IOS/Network/NCD/Manage.h
+++ b/Source/Core/Core/IOS/Network/NCD/Manage.h
@@ -20,6 +20,8 @@ public:
 
   IPCCommandResult IOCtlV(const IOCtlVRequest& request) override;
 
+  void DoState(PointerWrap& p) override;
+
 private:
   enum
   {
@@ -34,5 +36,6 @@ private:
   };
 
   Net::WiiNetConfig config;
+  u32 m_ipc_fd = 0;
 };
 }  // namespace IOS::HLE::Device
diff --git a/Source/Core/Core/State.cpp b/Source/Core/Core/State.cpp
index 823b39c1ba..31802ca471 100644
--- a/Source/Core/Core/State.cpp
+++ b/Source/Core/Core/State.cpp
@@ -74,7 +74,7 @@ static Common::Event g_compressAndDumpStateSyncEvent;
 static std::thread g_save_thread;
 
 // Don't forget to increase this after doing changes on the savestate system
-constexpr u32 STATE_VERSION = 126;  // Last changed in PR 9348
+constexpr u32 STATE_VERSION = 127;  // Last changed in PR 9300 (temp)
 
 // Maps savestate versions to Dolphin versions.
 // Versions after 42 don't need to be added to this list,