api: add pool/driver removal for uninstaller semantics

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

api/adapter.c

@@ -1750,12 +1750,18 @@ cleanupToken:
 }
 
 static WINTUN_STATUS
-DeleteAllOurAdapters(void)
+DeleteAllOurAdapters(_In_ WCHAR Pool[WINTUN_MAX_POOL], _Inout_ BOOL *RebootRequired)
 {
+    HANDLE Mutex = NamespaceTakePoolMutex(Pool);
+    if (!Mutex)
+        return ERROR_INVALID_HANDLE;
     DWORD Result = ERROR_SUCCESS;
     HDEVINFO DevInfo = SetupDiGetClassDevsExW(&GUID_DEVCLASS_NET, NULL, NULL, DIGCF_PRESENT, NULL, NULL, NULL);
     if (DevInfo == INVALID_HANDLE_VALUE)
+    {
+        NamespaceReleaseMutex(Mutex);
         return LOG_LAST_ERROR(L"Failed to get present adapters");
+    }
     SP_REMOVEDEVICE_PARAMS Params = { .ClassInstallHeader = { .cbSize = sizeof(SP_CLASSINSTALL_HEADER),
                                                               .InstallFunction = DIF_REMOVE },
                                       .Scope = DI_REMOVEDEVICE_GLOBAL };
@@ -1772,39 +1778,58 @@ DeleteAllOurAdapters(void)
         BOOL IsOurs;
         if (IsOurAdapter(DevInfo, &DevInfoData, &IsOurs) != ERROR_SUCCESS || !IsOurs)
             continue;
+        BOOL IsMember;
+        Result = IsPoolMember(Pool, DevInfo, &DevInfoData, &IsMember);
+        if (Result != ERROR_SUCCESS)
+        {
+            LOG(WINTUN_LOG_ERR, L"Failed to get pool membership");
+            break;
+        }
+        if (!IsMember)
+            continue;
 
         LOG(WINTUN_LOG_INFO, L"Force closing all open handles for existing adapter");
         if (ForceCloseWintunAdapterHandle(DevInfo, &DevInfoData) != ERROR_SUCCESS)
             LOG(WINTUN_LOG_WARN, L"Failed to force close adapter handles");
 
         LOG(WINTUN_LOG_INFO, L"Removing existing adapter");
-        if (!SetupDiSetClassInstallParamsW(DevInfo, &DevInfoData, &Params.ClassInstallHeader, sizeof(Params)) ||
+        if (SetupDiSetClassInstallParamsW(DevInfo, &DevInfoData, &Params.ClassInstallHeader, sizeof(Params)) &&
-            !SetupDiCallClassInstaller(DIF_REMOVE, DevInfo, &DevInfoData))
+            SetupDiCallClassInstaller(DIF_REMOVE, DevInfo, &DevInfoData))
+            *RebootRequired = *RebootRequired || CheckReboot(DevInfo, &DevInfoData);
+        else
         {
             LOG_LAST_ERROR(L"Failed to remove existing adapter");
             Result = Result != ERROR_SUCCESS ? Result : GetLastError();
         }
     }
     SetupDiDestroyDeviceInfoList(DevInfo);
+    NamespaceReleaseMutex(Mutex);
     return Result;
 }
 
 WINTUN_STATUS WINAPI
-WintunDeleteDriver(void)
+WintunDeletePoolDriver(_In_z_ WCHAR Pool[WINTUN_MAX_POOL], _Out_opt_ BOOL *RebootRequired)
 {
     if (!ElevateToSystem())
         return LOG_LAST_ERROR(L"Failed to impersonate SYSTEM user");
 
-    DWORD Result = ERROR_SUCCESS;
+    BOOL DummyRebootRequired;
+    if (!RebootRequired)
+        RebootRequired = &DummyRebootRequired;
+    *RebootRequired = FALSE;
 
+    DWORD Result;
     if (MAYBE_WOW64 && NativeMachine != IMAGE_FILE_PROCESS)
     {
-        Result = DeleteDriverViaRundll32();
+        Result = DeletePoolDriverViaRundll32(Pool, RebootRequired);
         RevertToSelf();
         return Result;
     }
 
-    /* DeleteAllOurAdapters(); */
+    Result = DeleteAllOurAdapters(Pool, RebootRequired);
+    if (Result != ERROR_SUCCESS)
+        goto cleanupToken;
+
     HANDLE DriverInstallationLock = NamespaceTakeDriverInstallationMutex();
     if (!DriverInstallationLock)
     {
@@ -1837,7 +1862,7 @@ WintunDeleteDriver(void)
         if (!_wcsicmp(DriverDetail->HardwareID, WINTUN_HWID))
         {
             LOG(WINTUN_LOG_INFO, TEXT("Removing existing driver"));
-            if (!SetupUninstallOEMInfW(PathFindFileNameW(DriverDetail->InfFileName), SUOI_FORCEDELETE, NULL))
+            if (!SetupUninstallOEMInfW(PathFindFileNameW(DriverDetail->InfFileName), 0, NULL))
             {
                 LOG_LAST_ERROR(TEXT("Unable to remove existing driver"));
                 Result = Result != ERROR_SUCCESS ? Result : GetLastError();

api/adapter.h

@@ -58,7 +58,7 @@ WINTUN_STATUS WINAPI
 WintunDeleteAdapter(_In_ const WINTUN_ADAPTER *Adapter, _In_ BOOL ForceCloseSessions, _Out_opt_ BOOL *RebootRequired);
 
 /**
- * @copydoc WINTUN_DELETE_DRIVER_FUNC
+ * @copydoc WINTUN_DELETE_POOL_DRIVER_FUNC
  */
 WINTUN_STATUS WINAPI
-WintunDeleteDriver(void);
+WintunDeletePoolDriver(_In_z_ WCHAR Pool[WINTUN_MAX_POOL], _Out_opt_ BOOL *RebootRequired);

api/exports.def

@@ -3,7 +3,7 @@ EXPORTS
 	WintunAllocateSendPacket
 	WintunCreateAdapter
 	WintunDeleteAdapter
-	WintunDeleteDriver
+	WintunDeletePoolDriver
 	WintunEndSession
 	WintunEnumAdapters
 	WintunFreeAdapter

api/rundll32.c

@@ -131,12 +131,19 @@ cleanup:
     Done();
 }
 
-VOID __stdcall DeleteDriver(HWND hwnd, HINSTANCE hinst, LPSTR lpszCmdLine, int nCmdShow)
+VOID __stdcall DeletePoolDriver(HWND hwnd, HINSTANCE hinst, LPSTR lpszCmdLine, int nCmdShow)
 {
 #    pragma EXPORT
 
     Init();
-    WriteFormatted(STD_OUTPUT_HANDLE, L"%1!X!", WintunDeleteDriver());
+    if (Argc < 2)
+        goto cleanup;
+
+    BOOL RebootRequired;
+    WINTUN_STATUS Ret = WintunDeletePoolDriver(Argv[2], &RebootRequired);
+    WriteFormatted(STD_OUTPUT_HANDLE, L"%1!X! %2!X!", Ret, RebootRequired);
+
+cleanup:
     Done();
 }
 #endif

api/rundll32.h

@@ -306,11 +306,15 @@ cleanupArgv:
 }
 
 static WINTUN_STATUS
-DeleteDriverViaRundll32()
+DeletePoolDriverViaRundll32(_In_z_ WCHAR Pool[WINTUN_MAX_POOL], _Inout_ BOOL *RebootRequired)
 {
     LOG(WINTUN_LOG_INFO, L"Spawning native process");
-    WCHAR Response[8 + 1];
+
-    DWORD Result = ExecuteRunDll32(L"DeleteDriver", Response, _countof(Response));
+    WCHAR Arguments[17 + WINTUN_MAX_POOL + 1];
+    if (_snwprintf_s(Arguments, _countof(Arguments), _TRUNCATE, L"DeletePoolDriver %s", Pool) == -1)
+        return LOG(WINTUN_LOG_ERR, L"Command line too long"), ERROR_INVALID_PARAMETER;
+    WCHAR Response[8 + 1 + 8 + 1];
+    DWORD Result = ExecuteRunDll32(Arguments, Response, _countof(Response));
     if (Result != ERROR_SUCCESS)
     {
         LOG(WINTUN_LOG_ERR, L"Error executing worker process");
@@ -318,13 +322,15 @@ DeleteDriverViaRundll32()
     }
     int Argc;
     WCHAR **Argv = CommandLineToArgvW(Response, &Argc);
-    if (Argc < 1)
+    if (Argc < 2)
     {
         LOG(WINTUN_LOG_ERR, L"Incomplete or invalid response");
         Result = ERROR_INVALID_PARAMETER;
         goto cleanupArgv;
     }
     Result = wcstoul(Argv[0], NULL, 16);
+    if (wcstoul(Argv[1], NULL, 16))
+        *RebootRequired = TRUE;
 cleanupArgv:
     LocalFree(Argv);
     return Result;

api/wintun.h

@@ -33,7 +33,7 @@ typedef void *WINTUN_ADAPTER_HANDLE;
  * @param Name          The requested name of the adapter. Zero-terminated string of up to MAX_ADAPTER_NAME-1
  *                      characters.
  *
- * @param RequestedGUID  The GUID of the created network adapter, which then influences NLA generation
+ * @param RequestedGUID The GUID of the created network adapter, which then influences NLA generation
  *                      deterministically. If it is set to NULL, the GUID is chosen by the system at random, and hence
  *                      a new NLA entry is created for each new adapter. It is called "requested" GUID because the API
  *                      it uses is completely undocumented, and so there could be minor interesting complications with
@@ -72,11 +72,18 @@ typedef WINTUN_STATUS(WINAPI *WINTUN_DELETE_ADAPTER_FUNC)(
     _Out_opt_ BOOL *RebootRequired);
 
 /**
- * Deletes all Wintun drivers from the driver store
+ * Deletes all Wintun adapters in a pool and if there are no more adapters in any other pools, also removes Wintun
+ * from the driver store, usually called by uninstallers.
+ *
+ * @param Pool             Name of the adapter pool. Zero-terminated string of up to WINTUN_MAX_POOL-1 characters.
+ *
+ * @param RebootRequired   Optional pointer to a boolean flag to be set to TRUE in case SetupAPI suggests a reboot.
  *
  * @return ERROR_SUCCESS on success; Win32 error code otherwise.
  */
-typedef WINTUN_STATUS(WINAPI *WINTUN_DELETE_DRIVER_FUNC)(void);
+typedef WINTUN_STATUS(WINAPI *WINTUN_DELETE_POOL_DRIVER_FUNC)(
+    _In_z_ WCHAR Pool[WINTUN_MAX_POOL],
+    _Out_opt_ BOOL *RebootRequired);
 
 /**
  * Called by WintunEnumAdapters for each adapter in the pool.

example/example.c

@@ -14,7 +14,7 @@
 
 static WINTUN_CREATE_ADAPTER_FUNC WintunCreateAdapter;
 static WINTUN_DELETE_ADAPTER_FUNC WintunDeleteAdapter;
-static WINTUN_DELETE_DRIVER_FUNC WintunDeleteDriver;
+static WINTUN_DELETE_POOL_DRIVER_FUNC WintunDeletePoolDriver;
 static WINTUN_ENUM_ADAPTERS_FUNC WintunEnumAdapters;
 static WINTUN_FREE_ADAPTER_FUNC WintunFreeAdapter;
 static WINTUN_GET_ADAPTER_FUNC WintunGetAdapter;
@@ -258,8 +258,9 @@ InitializeWintun(void)
         return NULL;
 #define X(Name, Type) ((Name = (Type)GetProcAddress(Wintun, #Name)) == NULL)
     if (X(WintunCreateAdapter, WINTUN_CREATE_ADAPTER_FUNC) || X(WintunDeleteAdapter, WINTUN_DELETE_ADAPTER_FUNC) ||
-        X(WintunDeleteDriver, WINTUN_DELETE_DRIVER_FUNC) || X(WintunEnumAdapters, WINTUN_ENUM_ADAPTERS_FUNC) ||
+        X(WintunDeletePoolDriver, WINTUN_DELETE_POOL_DRIVER_FUNC) ||
-        X(WintunFreeAdapter, WINTUN_FREE_ADAPTER_FUNC) || X(WintunGetAdapter, WINTUN_GET_ADAPTER_FUNC) ||
+        X(WintunEnumAdapters, WINTUN_ENUM_ADAPTERS_FUNC) || X(WintunFreeAdapter, WINTUN_FREE_ADAPTER_FUNC) ||
+        X(WintunGetAdapter, WINTUN_GET_ADAPTER_FUNC) ||
         X(WintunGetAdapterDeviceObject, WINTUN_GET_ADAPTER_DEVICE_OBJECT_FUNC) ||
         X(WintunGetAdapterGUID, WINTUN_GET_ADAPTER_GUID_FUNC) ||
         X(WintunGetAdapterLUID, WINTUN_GET_ADAPTER_LUID_FUNC) ||
@@ -315,17 +316,14 @@ main(void)
     }
 
     DWORD Version = WintunGetVersion();
-    Log(WINTUN_LOG_INFO,
+    Log(WINTUN_LOG_INFO, L"Wintun v%u.%u loaded", (Version >> 16) & 0xff, (Version >> 0) & 0xff);
-        L"Wintun v%u.%u loaded",
-        (Version >> 16) & 0xff,
-        (Version >> 0) & 0xff);
 
     MIB_UNICASTIPADDRESS_ROW AddressRow;
     InitializeUnicastIpAddressEntry(&AddressRow);
     WintunGetAdapterLUID(Adapter, &AddressRow.InterfaceLuid);
     AddressRow.Address.Ipv4.sin_family = AF_INET;
     AddressRow.Address.Ipv4.sin_addr.S_un.S_addr = htonl((10 << 24) | (6 << 16) | (7 << 8) | (7 << 0)); /* 10.6.7.7 */
-    AddressRow.OnLinkPrefixLength = 24;                                                                 /* This is a /24 network */
+    AddressRow.OnLinkPrefixLength = 24; /* This is a /24 network */
     Result = CreateUnicastIpAddressEntry(&AddressRow);
     if (Result != ERROR_SUCCESS)
     {