Remove only the TAP driver if it's not being used by other adapters on

Windows

5 files changed, 276 insertions, 14 deletions

diff --git a/windows/nsis-plugins/src/driverlogic/context.cpp b/windows/nsis-plugins/src/driverlogic/context.cpp
index 13cb781863..4f0cb2d291 100644
--- a/windows/nsis-plugins/src/driverlogic/context.cpp
+++ b/windows/nsis-plugins/src/driverlogic/context.cpp
@@ -1,21 +1,33 @@
 #include "stdafx.h"
 #include "context.h"
+
 #include <libcommon/string.h>
 #include <libcommon/error.h>
+#include <libcommon/memory.h>
 #include <log/log.h>
+
 #include <winsock2.h>
 #include <ws2ipdef.h>
 #include <iphlpapi.h>
 #include <windows.h>
+
 #include <vector>
 #include <list>
 #include <stdexcept>
 #include <sstream>
 #include <algorithm>
 
+#include <setupapi.h>
+#include <devguid.h>
+#include <combaseapi.h>
+#include <initguid.h>
+#include <devpkey.h>
+
 namespace
 {
 
+const wchar_t TAP_HARDWARE_ID[] = L"tap0901";
+
 std::set<Context::NetworkAdapter> GetAllAdapters()
 {
 	ULONG bufferSize = 0;
@@ -89,19 +101,57 @@ void LogAdapters(const std::wstring &description, const std::set<Context::Networ
 	PluginLogWithDetails(description, details);
 }
 
-} // anonymous namespace
-
-Context::BaselineStatus Context::establishBaseline()
+std::wstring GetNetCfgInstanceId(HDEVINFO devInfo, const SP_DEVINFO_DATA &devInfoData)
 {
-	m_baseline = GetAllAdapters();
+	HKEY hNet = SetupDiOpenDevRegKey(
+		devInfo,
+		const_cast<SP_DEVINFO_DATA *>(&devInfoData),
+		DICS_FLAG_GLOBAL,
+		0,
+		DIREG_DRV,
+		KEY_READ
+	);
 
-	auto tapAdapters = GetTapAdapters(m_baseline);
+	if (hNet == INVALID_HANDLE_VALUE)
+	{
+		throw std::runtime_error("SetupDiOpenDevRegKey Failed");
+	}
 
-	if (tapAdapters.empty())
+	std::vector<wchar_t> instanceId(MAX_PATH + sizeof(L'\0'));
+	DWORD strSize = instanceId.size() * sizeof(wchar_t);
+
+	const auto status = RegGetValueW(
+		hNet,
+		nullptr,
+		L"NetCfgInstanceId",
+		RRF_RT_REG_SZ,
+		nullptr,
+		instanceId.data(),
+		&strSize
+	);
+
+	RegCloseKey(hNet);
+
+	if (ERROR_SUCCESS != status)
 	{
-		return BaselineStatus::NO_TAP_ADAPTERS_PRESENT;
+		throw std::runtime_error("RegGetValue for NetCfgInstanceId failed");
 	}
 
+	instanceId[strSize / sizeof(wchar_t)] = L'\0';
+
+	return instanceId.data();
+}
+
+} // anonymous namespace
+
+//static
+std::optional<Context::NetworkAdapter> Context::FindMullvadAdapter(const std::set<Context::NetworkAdapter> &tapAdapters)
+{
+	if (tapAdapters.empty())
+	{
+		return std::nullopt;
+	}
+	
 	//
 	// Look for TAP adapter with alias "Mullvad".
 	//
@@ -113,14 +163,16 @@ Context::BaselineStatus Context::establishBaseline()
 			return 0 == _wcsicmp(candidate.alias.c_str(), alias.c_str());
 		});
 
-		return it != adapters.end();
+		return it;
 	};
 
 	static const wchar_t baseAlias[] = L"Mullvad";
 
-	if (findByAlias(tapAdapters, baseAlias))
+	const auto mullvadAdapter = findByAlias(tapAdapters, baseAlias);
+
+	if (tapAdapters.end() != mullvadAdapter)
 	{
-		return BaselineStatus::MULLVAD_ADAPTER_PRESENT;
+		return std::optional{ *mullvadAdapter };
 	}
 
 	//
@@ -135,12 +187,32 @@ Context::BaselineStatus Context::establishBaseline()
 
 		const auto alias = ss.str();
 
-		if (findByAlias(tapAdapters, alias))
+		const auto mullvadAdapter = findByAlias(tapAdapters, alias);
+
+		if (tapAdapters.end() != mullvadAdapter)
 		{
-			return BaselineStatus::MULLVAD_ADAPTER_PRESENT;
+			return std::optional{ *mullvadAdapter };
 		}
 	}
 
+	return std::nullopt;
+}
+
+Context::BaselineStatus Context::establishBaseline()
+{
+	m_baseline = GetAllAdapters();
+	const auto tapAdapters = GetTapAdapters(m_baseline);
+
+	if (tapAdapters.empty())
+	{
+		return BaselineStatus::NO_TAP_ADAPTERS_PRESENT;
+	}
+	
+	if (FindMullvadAdapter(tapAdapters).has_value())
+	{
+		return BaselineStatus::MULLVAD_ADAPTER_PRESENT;
+	}
+
 	return BaselineStatus::SOME_TAP_ADAPTERS_PRESENT;
 }
 
@@ -173,3 +245,119 @@ Context::NetworkAdapter Context::getNewAdapter()
 
 	return *added.begin();
 }
+
+//static
+Context::DeletionResult Context::DeleteMullvadAdapter()
+{
+	auto tapAdapters = GetTapAdapters(GetAllAdapters());
+	std::optional<NetworkAdapter> mullvadAdapter = FindMullvadAdapter(tapAdapters);
+
+	if (!mullvadAdapter.has_value())
+	{
+		throw std::runtime_error("Mullvad TAP adapter not found");
+	}
+
+	const auto mullvadGuid = mullvadAdapter.value().guid;
+
+	HDEVINFO devInfo = SetupDiGetClassDevsW(
+		&GUID_DEVCLASS_NET,
+		nullptr,
+		nullptr,
+		DIGCF_PRESENT
+	);
+
+	THROW_GLE_IF(INVALID_HANDLE_VALUE, devInfo, "SetupDiGetClassDevs() failed");
+
+	common::memory::ScopeDestructor cleanupDevList;
+	cleanupDevList += [&devInfo]()
+	{
+		SetupDiDestroyDeviceInfoList(devInfo);
+	};
+
+	SP_DEVINFO_DATA devInfoData;
+
+	std::vector<wchar_t> buffer;
+	DWORD nameLen;
+
+	int numRemainingAdapters = 0;
+
+	for (int memberIndex = 0; ; memberIndex++)
+	{
+		devInfoData = { 0 };
+		devInfoData.cbSize = sizeof(devInfoData);
+		
+		if (FALSE == SetupDiEnumDeviceInfo(devInfo, memberIndex, &devInfoData))
+		{
+			if (GetLastError() == ERROR_NO_MORE_ITEMS)
+			{
+				/* done */
+				break;
+			}
+			THROW_GLE("Error enumerating network adapters");
+		}
+
+		if (FALSE == SetupDiGetDeviceRegistryPropertyW(
+			devInfo,
+			&devInfoData,
+			SPDRP_HARDWAREID,
+			nullptr,
+			nullptr,
+			0,
+			&nameLen
+		))
+		{
+			const auto status = GetLastError();
+			if (ERROR_INSUFFICIENT_BUFFER != status)
+			{
+				/* ERROR_INSUFFICIENT_BUFFER is expected */
+				if (ERROR_INVALID_DATA == status)
+				{
+					/* ERROR_INVALID_DATA may mean that the property does not exist */
+					continue;
+				}
+				THROW_GLE("Error obtaining network adapter hardware ID length");
+			}
+		}
+
+		buffer.resize(nameLen / sizeof(wchar_t) + 1);
+		buffer[nameLen / sizeof(wchar_t)] = L'\0';
+
+		if (FALSE == SetupDiGetDeviceRegistryPropertyW(
+			devInfo,
+			&devInfoData,
+			SPDRP_HARDWAREID,
+			nullptr,
+			reinterpret_cast<PBYTE>(buffer.data()),
+			(buffer.size() - 1) * sizeof(wchar_t),
+			nullptr
+		))
+		{
+			THROW_GLE("Error obtaining network adapter hardware ID");
+		}
+
+		if (wcscmp(TAP_HARDWARE_ID, buffer.data()) == 0)
+		{
+			std::wstring netCfgInstanceId = GetNetCfgInstanceId(devInfo, devInfoData);
+			if (netCfgInstanceId.compare(mullvadGuid) != 0)
+			{
+				numRemainingAdapters++;
+				continue;
+			}
+
+			if (FALSE == SetupDiRemoveDevice(
+				devInfo,
+				&devInfoData
+			))
+			{
+				THROW_GLE("Error removing Mullvad TAP device");
+			}
+		}
+	}
+
+	if (numRemainingAdapters > 0)
+	{
+		return DeletionResult::SOME_REMAINING_TAP_ADAPTERS;
+	}
+	
+	return DeletionResult::NO_REMAINING_TAP_ADAPTERS;
+}
diff --git a/windows/nsis-plugins/src/driverlogic/context.h b/windows/nsis-plugins/src/driverlogic/context.h
index a93a3bcfcf..eabf884ba8 100644
--- a/windows/nsis-plugins/src/driverlogic/context.h
+++ b/windows/nsis-plugins/src/driverlogic/context.h
@@ -2,6 +2,7 @@
 
 #include <set>
 #include <string>
+#include <optional>
 
 class Context
 {
@@ -46,8 +47,18 @@ public:
 	//
 	NetworkAdapter getNewAdapter();
 
+	enum class DeletionResult
+	{
+		NO_REMAINING_TAP_ADAPTERS,
+		SOME_REMAINING_TAP_ADAPTERS
+	};
+
+	static DeletionResult DeleteMullvadAdapter();
+
 private:
 
+	static std::optional<NetworkAdapter> FindMullvadAdapter(const std::set<NetworkAdapter> &tapAdapters);
+
 	std::set<NetworkAdapter> m_baseline;
 	std::set<NetworkAdapter> m_currentState;
 };
diff --git a/windows/nsis-plugins/src/driverlogic/driverlogic.cpp b/windows/nsis-plugins/src/driverlogic/driverlogic.cpp
index 3bbe98bf8b..82259c015d 100644
--- a/windows/nsis-plugins/src/driverlogic/driverlogic.cpp
+++ b/windows/nsis-plugins/src/driverlogic/driverlogic.cpp
@@ -157,6 +157,68 @@ void __declspec(dllexport) NSISCALL EstablishBaseline
 }
 
 //
+// RemoveMullvadTap
+//
+// Deletes the Mullvad TAP adapter.
+//
+//
+enum class RemoveMullvadTapStatus
+{
+	GENERAL_ERROR = 0,
+	SUCCESS_NO_REMAINING_TAP_ADAPTERS,
+	SUCCESS_SOME_REMAINING_TAP_ADAPTERS
+};
+
+void __declspec(dllexport) NSISCALL RemoveMullvadTap
+(
+	HWND hwndParent,
+	int string_size,
+	LPTSTR variables,
+	stack_t **stacktop,
+	extra_parameters *extra,
+	...
+)
+{
+	EXDLL_INIT();
+
+	try
+	{
+		pushstring(L"");
+		
+		switch (Context::DeleteMullvadAdapter())
+		{
+			case Context::DeletionResult::NO_REMAINING_TAP_ADAPTERS:
+			{
+				pushint(RemoveMullvadTapStatus::SUCCESS_NO_REMAINING_TAP_ADAPTERS);
+				break;
+			}
+
+			case Context::DeletionResult::SOME_REMAINING_TAP_ADAPTERS:
+			{
+				pushint(RemoveMullvadTapStatus::SUCCESS_SOME_REMAINING_TAP_ADAPTERS);
+				break;
+			}
+
+			default:
+			{
+				throw std::runtime_error("Unexpected case");
+			}
+		}
+	}
+	catch (std::exception &err)
+	{
+		pushstring(common::string::ToWide(err.what()).c_str());
+		pushint(RemoveMullvadTapStatus::GENERAL_ERROR);
+	}
+	catch (...)
+	{
+		pushstring(L"Unspecified error");
+		pushint(RemoveMullvadTapStatus::GENERAL_ERROR);
+	}
+}
+
+
+//
 // IdentifyNewAdapter
 //
 // Call this function after installing a TAP adapter.
diff --git a/windows/nsis-plugins/src/driverlogic/driverlogic.def b/windows/nsis-plugins/src/driverlogic/driverlogic.def
index 1bd484d6be..b8735f1ada 100644
--- a/windows/nsis-plugins/src/driverlogic/driverlogic.def
+++ b/windows/nsis-plugins/src/driverlogic/driverlogic.def
@@ -5,4 +5,5 @@ EXPORTS
 Initialize
 EstablishBaseline
 IdentifyNewAdapter
+RemoveMullvadTap
 Deinitialize
diff --git a/windows/nsis-plugins/src/driverlogic/driverlogic.vcxproj b/windows/nsis-plugins/src/driverlogic/driverlogic.vcxproj
index 0e3932e8fa..d7cad2635f 100644
--- a/windows/nsis-plugins/src/driverlogic/driverlogic.vcxproj
+++ b/windows/nsis-plugins/src/driverlogic/driverlogic.vcxproj
@@ -70,7 +70,7 @@
       <GenerateDebugInformation>true</GenerateDebugInformation>
       <ImageHasSafeExceptionHandlers>false</ImageHasSafeExceptionHandlers>
       <AdditionalLibraryDirectories>$(ProjectDir)../../../../dist-assets/binaries/x86_64-pc-windows-msvc/nsis/;$(SolutionDir)bin\$(Platform)-$(Configuration)\</AdditionalLibraryDirectories>
-      <AdditionalDependencies>iphlpapi.lib;log.lib;libcommon.lib;pluginapi-x86-unicode.lib;kernel32.lib;user32.lib;gdi32.lib;winspool.lib;comdlg32.lib;advapi32.lib;shell32.lib;ole32.lib;oleaut32.lib;uuid.lib;odbc32.lib;odbccp32.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>setupapi.lib;iphlpapi.lib;log.lib;libcommon.lib;pluginapi-x86-unicode.lib;kernel32.lib;user32.lib;gdi32.lib;winspool.lib;comdlg32.lib;advapi32.lib;shell32.lib;ole32.lib;oleaut32.lib;uuid.lib;odbc32.lib;odbccp32.lib;%(AdditionalDependencies)</AdditionalDependencies>
       <IgnoreSpecificDefaultLibraries>libc.lib</IgnoreSpecificDefaultLibraries>
       <ModuleDefinitionFile>driverlogic.def</ModuleDefinitionFile>
     </Link>
@@ -96,7 +96,7 @@
       <GenerateDebugInformation>true</GenerateDebugInformation>
       <ImageHasSafeExceptionHandlers>false</ImageHasSafeExceptionHandlers>
       <AdditionalLibraryDirectories>$(ProjectDir)../../../../dist-assets/binaries/x86_64-pc-windows-msvc/nsis/;$(SolutionDir)bin\$(Platform)-$(Configuration)\</AdditionalLibraryDirectories>
-      <AdditionalDependencies>iphlpapi.lib;log.lib;libcommon.lib;pluginapi-x86-unicode.lib;kernel32.lib;user32.lib;gdi32.lib;winspool.lib;comdlg32.lib;advapi32.lib;shell32.lib;ole32.lib;oleaut32.lib;uuid.lib;odbc32.lib;odbccp32.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>setupapi.lib;iphlpapi.lib;log.lib;libcommon.lib;pluginapi-x86-unicode.lib;kernel32.lib;user32.lib;gdi32.lib;winspool.lib;comdlg32.lib;advapi32.lib;shell32.lib;ole32.lib;oleaut32.lib;uuid.lib;odbc32.lib;odbccp32.lib;%(AdditionalDependencies)</AdditionalDependencies>
       <IgnoreSpecificDefaultLibraries>libc.lib</IgnoreSpecificDefaultLibraries>
       <ModuleDefinitionFile>driverlogic.def</ModuleDefinitionFile>
     </Link>