api: simplify driver removal

When we install the Wintun driver to the store, we get exact oem<nn>.inf
filename of the driver in the store we just installed. Since the
installation should be only temporarily, we should uninstall only the
driver we installed.

This also eliminates the need for iterating driver store speeding up
things.

The code we removed was inherited from the installer.dll, where it made
perfect sense to remove all installed Wintun drivers in the update
process.

Suggested-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Simon Rozman <simon@rozman.si>

api/adapter.c

@@ -123,6 +123,15 @@ GetDeviceRegistryMultiString(
     }
 }
 
+static BOOL
+IsOurHardwareID(_In_z_ const WCHAR *Hwids)
+{
+    for (; Hwids[0]; Hwids += wcslen(Hwids) + 1)
+        if (!_wcsicmp(Hwids, WINTUN_HWID))
+            return TRUE;
+    return FALSE;
+}
+
 static WINTUN_STATUS
 IsOurAdapter(_In_ HDEVINFO DevInfo, _In_ SP_DEVINFO_DATA *DevInfoData, _Out_ BOOL *IsOurs)
 {
@@ -130,7 +139,7 @@ IsOurAdapter(_In_ HDEVINFO DevInfo, _In_ SP_DEVINFO_DATA *DevInfoData, _Out_ BOO
     DWORD Result = GetDeviceRegistryMultiString(DevInfo, DevInfoData, SPDRP_HARDWAREID, &Hwids);
     if (Result != ERROR_SUCCESS)
         return LOG(WINTUN_LOG_ERR, L"Failed to query hardware ID"), Result;
-    *IsOurs = DriverIsOurHardwareID(Hwids);
+    *IsOurs = IsOurHardwareID(Hwids);
     return ERROR_SUCCESS;
 }
 
@@ -869,6 +878,15 @@ cleanupQueriedStore:
     return Result;
 }
 
+
+static BOOL
+IsOurDrvInfoDetail(_In_ const SP_DRVINFO_DETAIL_DATA_W *DrvInfoDetailData)
+{
+    return DrvInfoDetailData->CompatIDsOffset > 1 && !_wcsicmp(DrvInfoDetailData->HardwareID, WINTUN_HWID) ||
+           DrvInfoDetailData->CompatIDsLength &&
+               IsOurHardwareID(DrvInfoDetailData->HardwareID + DrvInfoDetailData->CompatIDsOffset);
+}
+
 static BOOL
 IsNewer(_In_ const SP_DRVINFO_DATA_W *DrvInfoData, _In_ const FILETIME *DriverDate, _In_ DWORDLONG DriverVersion)
 {
@@ -1038,7 +1056,7 @@ CreateAdapter(
             LOG(WINTUN_LOG_WARN, L"Failed getting driver info detail");
             continue;
         }
-        if (!DriverIsOurDrvInfoDetail(DrvInfoDetailData))
+        if (!IsOurDrvInfoDetail(DrvInfoDetailData))
         {
             HeapFree(ModuleHeap, 0, DrvInfoDetailData);
             continue;
@@ -1581,14 +1599,22 @@ WintunCreateAdapter(
     }
 
     LOG(WINTUN_LOG_INFO, L"Installing driver");
-    if (!SetupCopyOEMInfW(InfPath, NULL, SPOST_PATH, 0, NULL, 0, NULL, NULL))
+    WCHAR InfStorePath[MAX_PATH];
+    WCHAR *InfStoreFilename;
+    if (!SetupCopyOEMInfW(InfPath, NULL, SPOST_PATH, 0, InfStorePath, _countof(InfStorePath), NULL, &InfStoreFilename))
     {
         Result = LOG_LAST_ERROR(L"Could not install driver to store");
         goto cleanupDelete;
     }
 
     Result = CreateAdapter(InfPath, Pool, Name, RequestedGUID, Adapter, RebootRequired);
-    DriverRemoveAllOurs();
+
+    LOG(WINTUN_LOG_INFO, L"Removing driver");
+    if (!SetupUninstallOEMInfW(InfStoreFilename, SUOI_FORCEDELETE, NULL))
+    {
+        LOG_LAST_ERROR(L"Unable to remove existing driver");
+        Result = Result != ERROR_SUCCESS ? Result : GetLastError();
+    }
 cleanupDelete:
     DeleteFileW(CatPath);
     DeleteFileW(SysPath);

api/adapter.h

@@ -9,6 +9,7 @@
 #include <SetupAPI.h>
 
 #define MAX_INSTANCE_ID MAX_PATH /* TODO: Is MAX_PATH always enough? */
+#define WINTUN_HWID L"Wintun"
 
 typedef struct _SP_DEVINFO_DATA_LIST
 {

api/api.vcxproj

@@ -196,7 +196,6 @@
     <ClInclude Include="api.h" />
     <ClInclude Include="adapter.h" />
     <ClInclude Include="atomic.h" />
-    <ClInclude Include="driver.h" />
     <ClInclude Include="logger.h" />
     <ClInclude Include="namespace.h" />
     <ClInclude Include="nci.h" />
@@ -208,7 +207,6 @@
   <ItemGroup>
     <ClCompile Include="api.c" />
     <ClCompile Include="adapter.c" />
-    <ClCompile Include="driver.c" />
     <ClCompile Include="logger.c" />
     <ClCompile Include="namespace.c" />
     <ClCompile Include="nci.c" />

api/api.vcxproj.filters

@@ -46,9 +46,6 @@
     <ClInclude Include="resource.h">
       <Filter>Header Files</Filter>
     </ClInclude>
-    <ClInclude Include="driver.h">
-      <Filter>Header Files</Filter>
-    </ClInclude>
     <ClInclude Include="adapter.h">
       <Filter>Header Files</Filter>
     </ClInclude>
@@ -84,9 +81,6 @@
     <ClCompile Include="resource.c">
       <Filter>Source Files</Filter>
     </ClCompile>
-    <ClCompile Include="driver.c">
-      <Filter>Source Files</Filter>
-    </ClCompile>
     <ClCompile Include="adapter.c">
       <Filter>Source Files</Filter>
     </ClCompile>

api/driver.c

@@ -1,72 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0
- *
- * Copyright (C) 2018-2020 WireGuard LLC. All Rights Reserved.
- */
-
-#include "pch.h"
-
-#pragma warning(disable : 4221) /* nonstandard: address of automatic in initializer */
-
-BOOL
-DriverIsOurHardwareID(_In_z_ const WCHAR *Hwids)
-{
-    for (; Hwids[0]; Hwids += wcslen(Hwids) + 1)
-        if (!_wcsicmp(Hwids, WINTUN_HWID))
-            return TRUE;
-    return FALSE;
-}
-
-BOOL
-DriverIsOurDrvInfoDetail(_In_ const SP_DRVINFO_DETAIL_DATA_W *DrvInfoDetailData)
-{
-    return DrvInfoDetailData->CompatIDsOffset > 1 && !_wcsicmp(DrvInfoDetailData->HardwareID, WINTUN_HWID) ||
-           DrvInfoDetailData->CompatIDsLength &&
-               DriverIsOurHardwareID(DrvInfoDetailData->HardwareID + DrvInfoDetailData->CompatIDsOffset);
-}
-
-WINTUN_STATUS
-DriverRemoveAllOurs(void)
-{
-    HDEVINFO DevInfo = SetupDiGetClassDevsW(&GUID_DEVCLASS_NET, NULL, NULL, 0);
-    if (!DevInfo)
-        return LOG_LAST_ERROR(L"Failed to request device information");
-    DWORD Result = ERROR_SUCCESS;
-    if (!SetupDiBuildDriverInfoList(DevInfo, NULL, SPDIT_CLASSDRIVER))
-    {
-        Result = LOG_LAST_ERROR(L"Failed to build list of drivers");
-        goto cleanupDeviceInfoSet;
-    }
-    for (DWORD EnumIndex = 0;; ++EnumIndex)
-    {
-        SP_DRVINFO_DATA_W DrvInfoData = { .cbSize = sizeof(DrvInfoData) };
-        if (!SetupDiEnumDriverInfoW(DevInfo, NULL, SPDIT_CLASSDRIVER, EnumIndex, &DrvInfoData))
-        {
-            if (GetLastError() == ERROR_NO_MORE_ITEMS)
-                break;
-            continue;
-        }
-        SP_DRVINFO_DETAIL_DATA_W *DrvInfoDetailData;
-        if (AdapterGetDrvInfoDetail(DevInfo, NULL, &DrvInfoData, &DrvInfoDetailData) != ERROR_SUCCESS)
-        {
-            LOG(WINTUN_LOG_WARN, L"Failed getting driver info detail");
-            continue;
-        }
-        if (!DriverIsOurDrvInfoDetail(DrvInfoDetailData))
-        {
-            HeapFree(ModuleHeap, 0, DrvInfoDetailData);
-            continue;
-        }
-        PathStripPathW(DrvInfoDetailData->InfFileName);
-        LOG(WINTUN_LOG_INFO, L"Removing existing driver");
-        if (!SetupUninstallOEMInfW(DrvInfoDetailData->InfFileName, SUOI_FORCEDELETE, NULL))
-        {
-            LOG_LAST_ERROR(L"Unable to remove existing driver");
-            Result = Result != ERROR_SUCCESS ? Result : GetLastError();
-        }
-        HeapFree(ModuleHeap, 0, DrvInfoDetailData);
-    }
-    SetupDiDestroyDriverInfoList(DevInfo, NULL, SPDIT_CLASSDRIVER);
-cleanupDeviceInfoSet:
-    SetupDiDestroyDeviceInfoList(DevInfo);
-    return Result;
-}

api/driver.h

@@ -1,38 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0
- *
- * Copyright (C) 2018-2020 WireGuard LLC. All Rights Reserved.
- */
-
-#pragma once
-
-#include "wintun.h"
-#include <Windows.h>
-
-#define WINTUN_HWID L"Wintun"
-
-/**
- * Tests if any of the hardware IDs match ours.
- *
- * @param Hwids         Multi-string containing a list of hardware IDs.
- *
- * @return TRUE on match; FALSE otherwise.
- */
-BOOL
-DriverIsOurHardwareID(_In_z_ const WCHAR *Hwids);
-
-/**
- * Tests if hardware ID or any of the compatible IDs match ours.
- *
- * @param DrvInfoDetailData  Detailed information about a particular driver information structure.
- *
- * @return TRUE on match; FALSE otherwise.
- */
-BOOL
-DriverIsOurDrvInfoDetail(_In_ const SP_DRVINFO_DETAIL_DATA_W *DrvInfoDetailData);
-
-/**
- * Removes all Wintun drivers from the driver store.
- *
- * @return ERROR_SUCCESS on success or the adapter was not found; Win32 error code otherwise.
- */
-WINTUN_STATUS DriverRemoveAllOurs(void);

api/pch.h

@@ -8,7 +8,6 @@
 #include "adapter.h"
 #include "atomic.h"
 #include "api.h"
-#include "driver.h"
 #include "logger.h"
 #include "namespace.h"
 #include "nci.h"