api: only mark GUID as in-use if Status != NotPresent

Signed-off-by: Jason A. Donenfeld <[email protected]>

Author: zx2c4

api/adapter.c

@@ -3,22 +3,13 @@
  * Copyright (C) 2018-2021 WireGuard LLC. All Rights Reserved.
  */
 
-#include "adapter.h"
-#include "elevate.h"
-#include "entry.h"
-#include "logger.h"
-#include "namespace.h"
-#include "nci.h"
-#include "ntdll.h"
-#include "registry.h"
-#include "resource.h"
-#include "wintun-inf.h"
-
+#include <WinSock2.h>
 #include <Windows.h>
 #include <winternl.h>
 #define _NTDEF_ /* TODO: figure out how to include ntsecapi and winternal together without requiring this */
 #include <cfgmgr32.h>
 #include <devguid.h>
+#include <ws2tcpip.h>
 #include <iphlpapi.h>
 #include <ndisguid.h>
 #include <NTSecAPI.h>
@@ -28,6 +19,17 @@
 #include <initguid.h> /* Keep these two at bottom in this order, so that we only generate extra GUIDs for devpkey. The other keys we'll get from uuid.lib like usual. */
 #include <devpkey.h>
 
+#include "adapter.h"
+#include "elevate.h"
+#include "entry.h"
+#include "logger.h"
+#include "namespace.h"
+#include "nci.h"
+#include "ntdll.h"
+#include "registry.h"
+#include "resource.h"
+#include "wintun-inf.h"
+
 #pragma warning(disable : 4221) /* nonstandard: address of automatic in initializer */
 
 #define WAIT_FOR_REGISTRY_TIMEOUT 10000            /* ms */
@@ -1452,8 +1454,9 @@ static _Return_type_success_(return != NULL) WINTUN_ADAPTER *CreateAdapter(
         if (RegOpenKeyExW(HKEY_LOCAL_MACHINE, RegPath, 0, KEY_QUERY_VALUE, &Key) == ERROR_SUCCESS)
         {
             RegCloseKey(Key);
-            NET_LUID Luid;
-            if (ConvertInterfaceGuidToLuid(RequestedGUID, &Luid) == NO_ERROR)
+            MIB_IF_ROW2 IfRow = { 0 };
+            if (ConvertInterfaceGuidToLuid(RequestedGUID, &IfRow.InterfaceLuid) == NO_ERROR &&
+                GetIfEntry2(&IfRow) == NO_ERROR && IfRow.OperStatus != IfOperStatusNotPresent)
             {
                 SetLastError(
                     LOG_ERROR(ERROR_ALREADY_EXISTS, L"Requested GUID is already in use: %s", RequestedGUIDStr));