1 files changed, 154 insertions, 0 deletions
diff --git a/api/namespace.c b/api/namespace.c
new file mode 100644
index 0000000..3248edb
--- /dev/null
+++ b/api/namespace.c
@@ -0,0 +1,154 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (C) 2018-2021 WireGuard LLC. All Rights Reserved.
+ */
+
+#include "logger.h"
+#include "main.h"
+#include "namespace.h"
+
+#include <Windows.h>
+#include <winternl.h>
+#include <winefs.h>
+#include <wchar.h>
+#include <stdlib.h>
+
+static HANDLE PrivateNamespace = NULL;
+static HANDLE BoundaryDescriptor = NULL;
+static CRITICAL_SECTION Initializing;
+
+static _Return_type_success_(return != FALSE)
+BOOL NamespaceRuntimeInit(VOID)
+{
+    DWORD LastError;
+
+    EnterCriticalSection(&Initializing);
+    if (PrivateNamespace)
+    {
+        LeaveCriticalSection(&Initializing);
+        return TRUE;
+    }
+
+    BYTE Sid[MAX_SID_SIZE];
+    DWORD SidSize = sizeof(Sid);
+    if (!CreateWellKnownSid(IsLocalSystem ? WinLocalSystemSid : WinBuiltinAdministratorsSid, NULL, Sid, &SidSize))
+    {
+        LastError = LOG_LAST_ERROR(L"Failed to create SID");
+        goto cleanupLeaveCriticalSection;
+    }
+
+    BoundaryDescriptor = CreateBoundaryDescriptorW(L"Wintun", 0);
+    if (!BoundaryDescriptor)
+    {
+        LastError = LOG_LAST_ERROR(L"Failed to create boundary descriptor");
+        goto cleanupLeaveCriticalSection;
+    }
+    if (!AddSIDToBoundaryDescriptor(&BoundaryDescriptor, Sid))
+    {
+        LastError = LOG_LAST_ERROR(L"Failed to add SID to boundary descriptor");
+        goto cleanupBoundaryDescriptor;
+    }
+
+    for (;;)
+    {
+        if ((PrivateNamespace = CreatePrivateNamespaceW(&SecurityAttributes, BoundaryDescriptor, L"Wintun")) != NULL)
+            break;
+        if ((LastError = GetLastError()) == ERROR_ALREADY_EXISTS)
+        {
+            if ((PrivateNamespace = OpenPrivateNamespaceW(BoundaryDescriptor, L"Wintun")) != NULL)
+                break;
+            if ((LastError = GetLastError()) == ERROR_PATH_NOT_FOUND)
+                continue;
+            LOG_ERROR(LastError, L"Failed to open private namespace");
+        }
+        else
+            LOG_ERROR(LastError, L"Failed to create private namespace");
+        goto cleanupBoundaryDescriptor;
+    }
+
+    LeaveCriticalSection(&Initializing);
+    return TRUE;
+
+cleanupBoundaryDescriptor:
+    DeleteBoundaryDescriptor(BoundaryDescriptor);
+cleanupLeaveCriticalSection:
+    LeaveCriticalSection(&Initializing);
+    SetLastError(LastError);
+    return FALSE;
+}
+
+_Use_decl_annotations_
+HANDLE
+NamespaceTakeDriverInstallationMutex(VOID)
+{
+    if (!NamespaceRuntimeInit())
+        return NULL;
+    HANDLE Mutex = CreateMutexW(&SecurityAttributes, FALSE, L"Wintun\\Wintun-Driver-Installation-Mutex");
+    if (!Mutex)
+    {
+        LOG_LAST_ERROR(L"Failed to create mutex");
+        return NULL;
+    }
+    DWORD Result = WaitForSingleObject(Mutex, INFINITE);
+    switch (Result)
+    {
+    case WAIT_OBJECT_0:
+    case WAIT_ABANDONED:
+        return Mutex;
+    }
+    LOG(WINTUN_LOG_ERR, L"Failed to get mutex (status: 0x%x)", Result);
+    CloseHandle(Mutex);
+    SetLastError(ERROR_GEN_FAILURE);
+    return NULL;
+}
+
+_Use_decl_annotations_
+HANDLE
+NamespaceTakeDeviceInstallationMutex(VOID)
+{
+    if (!NamespaceRuntimeInit())
+        return NULL;
+    HANDLE Mutex = CreateMutexW(&SecurityAttributes, FALSE, L"Wintun\\Wintun-Device-Installation-Mutex");
+    if (!Mutex)
+    {
+        LOG_LAST_ERROR(L"Failed to create mutex");
+        return NULL;
+    }
+    DWORD Result = WaitForSingleObject(Mutex, INFINITE);
+    switch (Result)
+    {
+    case WAIT_OBJECT_0:
+    case WAIT_ABANDONED:
+        return Mutex;
+    }
+    LOG(WINTUN_LOG_ERR, L"Failed to get mutex (status: 0x%x)", Result);
+    CloseHandle(Mutex);
+    SetLastError(ERROR_GEN_FAILURE);
+    return NULL;
+}
+
+_Use_decl_annotations_
+VOID
+NamespaceReleaseMutex(HANDLE Mutex)
+{
+    ReleaseMutex(Mutex);
+    CloseHandle(Mutex);
+}
+
+VOID NamespaceInit(VOID)
+{
+    InitializeCriticalSection(&Initializing);
+}
+
+VOID NamespaceDone(VOID)
+{
+    EnterCriticalSection(&Initializing);
+    if (PrivateNamespace)
+    {
+        ClosePrivateNamespace(PrivateNamespace, 0);
+        DeleteBoundaryDescriptor(BoundaryDescriptor);
+        PrivateNamespace = NULL;
+    }
+    LeaveCriticalSection(&Initializing);
+    DeleteCriticalSection(&Initializing);
+}