Directly link with ntdll on Windows
[wimlib] / src / win32_common.c
index 7f0521e..086397a 100644 (file)
@@ -3,22 +3,20 @@
  */
 
 /*
- * Copyright (C) 2013, 2014 Eric Biggers
+ * Copyright (C) 2013-2016 Eric Biggers
  *
- * This file is part of wimlib, a library for working with WIM files.
+ * This file is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your option) any
+ * later version.
  *
- * wimlib is free software; you can redistribute it and/or modify it under the
- * terms of the GNU General Public License as published by the Free
- * Software Foundation; either version 3 of the License, or (at your option)
- * any later version.
- *
- * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
- * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
- * A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * This file is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
  * details.
  *
- * You should have received a copy of the GNU General Public License
- * along with wimlib; if not, see http://www.gnu.org/licenses/.
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this file; if not, see http://www.gnu.org/licenses/.
  */
 
 #ifdef __WIN32__
 #  include "config.h"
 #endif
 
-#include <errno.h>
-
 #include "wimlib/win32_common.h"
+
+#include "wimlib/assert.h"
 #include "wimlib/error.h"
 #include "wimlib/util.h"
-
-static int
-win32_error_to_errno(DWORD err_code)
-{
-       /* This mapping is that used in Cygwin.
-        * Some of these choices are arbitrary. */
-       switch (err_code) {
-       case ERROR_ACCESS_DENIED:
-               return EACCES;
-       case ERROR_ACTIVE_CONNECTIONS:
-               return EAGAIN;
-       case ERROR_ALREADY_EXISTS:
-               return EEXIST;
-       case ERROR_BAD_DEVICE:
-               return ENODEV;
-       case ERROR_BAD_EXE_FORMAT:
-               return ENOEXEC;
-       case ERROR_BAD_NETPATH:
-               return ENOENT;
-       case ERROR_BAD_NET_NAME:
-               return ENOENT;
-       case ERROR_BAD_NET_RESP:
-               return ENOSYS;
-       case ERROR_BAD_PATHNAME:
-               return ENOENT;
-       case ERROR_BAD_PIPE:
-               return EINVAL;
-       case ERROR_BAD_UNIT:
-               return ENODEV;
-       case ERROR_BAD_USERNAME:
-               return EINVAL;
-       case ERROR_BEGINNING_OF_MEDIA:
-               return EIO;
-       case ERROR_BROKEN_PIPE:
-               return EPIPE;
-       case ERROR_BUSY:
-               return EBUSY;
-       case ERROR_BUS_RESET:
-               return EIO;
-       case ERROR_CALL_NOT_IMPLEMENTED:
-               return ENOSYS;
-       case ERROR_CANNOT_MAKE:
-               return EPERM;
-       case ERROR_CHILD_NOT_COMPLETE:
-               return EBUSY;
-       case ERROR_COMMITMENT_LIMIT:
-               return EAGAIN;
-       case ERROR_CRC:
-               return EIO;
-       case ERROR_DEVICE_DOOR_OPEN:
-               return EIO;
-       case ERROR_DEVICE_IN_USE:
-               return EAGAIN;
-       case ERROR_DEVICE_REQUIRES_CLEANING:
-               return EIO;
-       case ERROR_DIRECTORY:
-               return ENOTDIR;
-       case ERROR_DIR_NOT_EMPTY:
-               return ENOTEMPTY;
-       case ERROR_DISK_CORRUPT:
-               return EIO;
-       case ERROR_DISK_FULL:
-               return ENOSPC;
-#ifdef ENOTUNIQ
-       case ERROR_DUP_NAME:
-               return ENOTUNIQ;
-#endif
-       case ERROR_EAS_DIDNT_FIT:
-               return ENOSPC;
-#ifdef ENOTSUP
-       case ERROR_EAS_NOT_SUPPORTED:
-               return ENOTSUP;
-#endif
-       case ERROR_EA_LIST_INCONSISTENT:
-               return EINVAL;
-       case ERROR_EA_TABLE_FULL:
-               return ENOSPC;
-       case ERROR_END_OF_MEDIA:
-               return ENOSPC;
-       case ERROR_EOM_OVERFLOW:
-               return EIO;
-       case ERROR_EXE_MACHINE_TYPE_MISMATCH:
-               return ENOEXEC;
-       case ERROR_EXE_MARKED_INVALID:
-               return ENOEXEC;
-       case ERROR_FILEMARK_DETECTED:
-               return EIO;
-       case ERROR_FILENAME_EXCED_RANGE:
-               return ENAMETOOLONG;
-       case ERROR_FILE_CORRUPT:
-               return EEXIST;
-       case ERROR_FILE_EXISTS:
-               return EEXIST;
-       case ERROR_FILE_INVALID:
-               return ENXIO;
-       case ERROR_FILE_NOT_FOUND:
-               return ENOENT;
-       case ERROR_HANDLE_DISK_FULL:
-               return ENOSPC;
-#ifdef ENODATA
-       case ERROR_HANDLE_EOF:
-               return ENODATA;
-#endif
-       case ERROR_INVALID_ADDRESS:
-               return EINVAL;
-       case ERROR_INVALID_AT_INTERRUPT_TIME:
-               return EINTR;
-       case ERROR_INVALID_BLOCK_LENGTH:
-               return EIO;
-       case ERROR_INVALID_DATA:
-               return EINVAL;
-       case ERROR_INVALID_DRIVE:
-               return ENODEV;
-       case ERROR_INVALID_EA_NAME:
-               return EINVAL;
-       case ERROR_INVALID_EXE_SIGNATURE:
-               return ENOEXEC;
-#ifdef EBADRQC
-       case ERROR_INVALID_FUNCTION:
-               return EBADRQC;
-#endif
-       case ERROR_INVALID_HANDLE:
-               return EBADF;
-       case ERROR_INVALID_NAME:
-               return ENOENT;
-       case ERROR_INVALID_PARAMETER:
-               return EINVAL;
-       case ERROR_INVALID_SIGNAL_NUMBER:
-               return EINVAL;
-       case ERROR_IOPL_NOT_ENABLED:
-               return ENOEXEC;
-       case ERROR_IO_DEVICE:
-               return EIO;
-       case ERROR_IO_INCOMPLETE:
-               return EAGAIN;
-       case ERROR_IO_PENDING:
-               return EAGAIN;
-       case ERROR_LOCK_VIOLATION:
-               return EBUSY;
-       case ERROR_MAX_THRDS_REACHED:
-               return EAGAIN;
-       case ERROR_META_EXPANSION_TOO_LONG:
-               return EINVAL;
-       case ERROR_MOD_NOT_FOUND:
-               return ENOENT;
-#ifdef EMSGSIZE
-       case ERROR_MORE_DATA:
-               return EMSGSIZE;
-#endif
-       case ERROR_NEGATIVE_SEEK:
-               return EINVAL;
-       case ERROR_NETNAME_DELETED:
-               return ENOENT;
-       case ERROR_NOACCESS:
-               return EFAULT;
-       case ERROR_NONE_MAPPED:
-               return EINVAL;
-       case ERROR_NONPAGED_SYSTEM_RESOURCES:
-               return EAGAIN;
-#ifdef ENOLINK
-       case ERROR_NOT_CONNECTED:
-               return ENOLINK;
-#endif
-       case ERROR_NOT_ENOUGH_MEMORY:
-               return ENOMEM;
-       case ERROR_NOT_OWNER:
-               return EPERM;
-#ifdef ENOMEDIUM
-       case ERROR_NOT_READY:
-               return ENOMEDIUM;
-#endif
-       case ERROR_NOT_SAME_DEVICE:
-               return EXDEV;
-       case ERROR_NOT_SUPPORTED:
-               return ENOSYS;
-       case ERROR_NO_DATA:
-               return EPIPE;
-       case ERROR_NO_DATA_DETECTED:
-               return EIO;
-#ifdef ENOMEDIUM
-       case ERROR_NO_MEDIA_IN_DRIVE:
-               return ENOMEDIUM;
-#endif
-#ifdef ENMFILE
-       case ERROR_NO_MORE_FILES:
-               return ENMFILE;
-#endif
-#ifdef ENMFILE
-       case ERROR_NO_MORE_ITEMS:
-               return ENMFILE;
-#endif
-       case ERROR_NO_MORE_SEARCH_HANDLES:
-               return ENFILE;
-       case ERROR_NO_PROC_SLOTS:
-               return EAGAIN;
-       case ERROR_NO_SIGNAL_SENT:
-               return EIO;
-       case ERROR_NO_SYSTEM_RESOURCES:
-               return EFBIG;
-       case ERROR_NO_TOKEN:
-               return EINVAL;
-       case ERROR_OPEN_FAILED:
-               return EIO;
-       case ERROR_OPEN_FILES:
-               return EAGAIN;
-       case ERROR_OUTOFMEMORY:
-               return ENOMEM;
-       case ERROR_PAGED_SYSTEM_RESOURCES:
-               return EAGAIN;
-       case ERROR_PAGEFILE_QUOTA:
-               return EAGAIN;
-       case ERROR_PATH_NOT_FOUND:
-               return ENOENT;
-       case ERROR_PIPE_BUSY:
-               return EBUSY;
-       case ERROR_PIPE_CONNECTED:
-               return EBUSY;
-#ifdef ECOMM
-       case ERROR_PIPE_LISTENING:
-               return ECOMM;
-       case ERROR_PIPE_NOT_CONNECTED:
-               return ECOMM;
-#endif
-       case ERROR_POSSIBLE_DEADLOCK:
-               return EDEADLOCK;
-       case ERROR_PRIVILEGE_NOT_HELD:
-               return EPERM;
-       case ERROR_PROCESS_ABORTED:
-               return EFAULT;
-       case ERROR_PROC_NOT_FOUND:
-               return ESRCH;
-#ifdef ENONET
-       case ERROR_REM_NOT_LIST:
-               return ENONET;
-#endif
-       case ERROR_SECTOR_NOT_FOUND:
-               return EINVAL;
-       case ERROR_SEEK:
-               return EINVAL;
-       case ERROR_SETMARK_DETECTED:
-               return EIO;
-       case ERROR_SHARING_BUFFER_EXCEEDED:
-               return ENOLCK;
-       case ERROR_SHARING_VIOLATION:
-               return EBUSY;
-       case ERROR_SIGNAL_PENDING:
-               return EBUSY;
-       case ERROR_SIGNAL_REFUSED:
-               return EIO;
-#ifdef ELIBBAD
-       case ERROR_SXS_CANT_GEN_ACTCTX:
-               return ELIBBAD;
-#endif
-       case ERROR_THREAD_1_INACTIVE:
-               return EINVAL;
-       case ERROR_TOO_MANY_LINKS:
-               return EMLINK;
-       case ERROR_TOO_MANY_OPEN_FILES:
-               return EMFILE;
-       case ERROR_WAIT_NO_CHILDREN:
-               return ECHILD;
-       case ERROR_WORKING_SET_QUOTA:
-               return EAGAIN;
-       case ERROR_WRITE_PROTECT:
-               return EROFS;
-       default:
-               return -1;
-       }
-}
-
-void
-set_errno_from_win32_error(DWORD err)
-{
-       errno = win32_error_to_errno(err);
-}
-
-void
-set_errno_from_GetLastError(void)
-{
-       set_errno_from_win32_error(GetLastError());
-}
-
-void
-set_errno_from_nt_status(NTSTATUS status)
-{
-       set_errno_from_win32_error((*func_RtlNtStatusToDosError)(status));
-}
+#include "wimlib/win32_vss.h"
 
 static bool
 win32_modify_privilege(const wchar_t *privilege, bool enable)
@@ -352,16 +64,21 @@ out:
 static bool
 win32_modify_capture_privileges(bool enable)
 {
-       return win32_modify_privilege(SE_BACKUP_NAME, enable)
-           && win32_modify_privilege(SE_SECURITY_NAME, enable);
+       bool ok = true;
+       ok &= win32_modify_privilege(SE_BACKUP_NAME, enable);
+       ok &= win32_modify_privilege(SE_SECURITY_NAME, enable);
+       return ok;
 }
 
 static bool
 win32_modify_apply_privileges(bool enable)
 {
-       return win32_modify_privilege(SE_RESTORE_NAME, enable)
-           && win32_modify_privilege(SE_SECURITY_NAME, enable)
-           && win32_modify_privilege(SE_TAKE_OWNERSHIP_NAME, enable);
+       bool ok = true;
+       ok &= win32_modify_privilege(SE_RESTORE_NAME, enable);
+       ok &= win32_modify_privilege(SE_SECURITY_NAME, enable);
+       ok &= win32_modify_privilege(SE_TAKE_OWNERSHIP_NAME, enable);
+       ok &= win32_modify_privilege(SE_MANAGE_VOLUME_NAME, enable);
+       return ok;
 }
 
 static void
@@ -375,100 +92,6 @@ win32_release_capture_and_apply_privileges(void)
 
 /* ntdll.dll  */
 
-NTSTATUS (WINAPI *func_NtCreateFile)(PHANDLE FileHandle,
-                                    ACCESS_MASK DesiredAccess,
-                                    POBJECT_ATTRIBUTES ObjectAttributes,
-                                    PIO_STATUS_BLOCK IoStatusBlock,
-                                    PLARGE_INTEGER AllocationSize,
-                                    ULONG FileAttributes,
-                                    ULONG ShareAccess,
-                                    ULONG CreateDisposition,
-                                    ULONG CreateOptions,
-                                    PVOID EaBuffer,
-                                    ULONG EaLength);
-
-NTSTATUS (WINAPI *func_NtOpenFile) (PHANDLE FileHandle,
-                                   ACCESS_MASK DesiredAccess,
-                                   POBJECT_ATTRIBUTES ObjectAttributes,
-                                   PIO_STATUS_BLOCK IoStatusBlock,
-                                   ULONG ShareAccess,
-                                   ULONG OpenOptions);
-
-NTSTATUS (WINAPI *func_NtReadFile) (HANDLE FileHandle,
-                                   HANDLE Event,
-                                   PIO_APC_ROUTINE ApcRoutine,
-                                   PVOID ApcContext,
-                                   PIO_STATUS_BLOCK IoStatusBlock,
-                                   PVOID Buffer,
-                                   ULONG Length,
-                                   PLARGE_INTEGER ByteOffset,
-                                   PULONG Key);
-
-NTSTATUS (WINAPI *func_NtWriteFile) (HANDLE FileHandle,
-                                    HANDLE Event,
-                                    PIO_APC_ROUTINE ApcRoutine,
-                                    PVOID ApcContext,
-                                    PIO_STATUS_BLOCK IoStatusBlock,
-                                    PVOID Buffer,
-                                    ULONG Length,
-                                    PLARGE_INTEGER ByteOffset,
-                                    PULONG Key);
-
-NTSTATUS (WINAPI *func_NtQueryInformationFile)(HANDLE FileHandle,
-                                              PIO_STATUS_BLOCK IoStatusBlock,
-                                              PVOID FileInformation,
-                                              ULONG Length,
-                                              FILE_INFORMATION_CLASS FileInformationClass);
-
-NTSTATUS (WINAPI *func_NtQuerySecurityObject)(HANDLE handle,
-                                             SECURITY_INFORMATION SecurityInformation,
-                                             PSECURITY_DESCRIPTOR SecurityDescriptor,
-                                             ULONG Length,
-                                             PULONG LengthNeeded);
-
-NTSTATUS (WINAPI *func_NtQueryDirectoryFile) (HANDLE FileHandle,
-                                             HANDLE Event,
-                                             PIO_APC_ROUTINE ApcRoutine,
-                                             PVOID ApcContext,
-                                             PIO_STATUS_BLOCK IoStatusBlock,
-                                             PVOID FileInformation,
-                                             ULONG Length,
-                                             FILE_INFORMATION_CLASS FileInformationClass,
-                                             BOOLEAN ReturnSingleEntry,
-                                             PUNICODE_STRING FileName,
-                                             BOOLEAN RestartScan);
-
-NTSTATUS (WINAPI *func_NtQueryVolumeInformationFile) (HANDLE FileHandle,
-                                                     PIO_STATUS_BLOCK IoStatusBlock,
-                                                     PVOID FsInformation,
-                                                     ULONG Length,
-                                                     FS_INFORMATION_CLASS FsInformationClass);
-
-NTSTATUS (WINAPI *func_NtSetInformationFile)(HANDLE FileHandle,
-                                            PIO_STATUS_BLOCK IoStatusBlock,
-                                            PVOID FileInformation,
-                                            ULONG Length,
-                                            FILE_INFORMATION_CLASS FileInformationClass);
-
-NTSTATUS (WINAPI *func_NtSetSecurityObject)(HANDLE Handle,
-                                           SECURITY_INFORMATION SecurityInformation,
-                                           PSECURITY_DESCRIPTOR SecurityDescriptor);
-
-NTSTATUS (WINAPI *func_NtFsControlFile) (HANDLE FileHandle,
-                                        HANDLE Event,
-                                        PIO_APC_ROUTINE ApcRoutine,
-                                        PVOID ApcContext,
-                                        PIO_STATUS_BLOCK IoStatusBlock,
-                                        ULONG FsControlCode,
-                                        PVOID InputBuffer,
-                                        ULONG InputBufferLength,
-                                        PVOID OutputBuffer,
-                                        ULONG OutputBufferLength);
-
-NTSTATUS (WINAPI *func_NtClose) (HANDLE Handle);
-
-DWORD (WINAPI *func_RtlNtStatusToDosError)(NTSTATUS status);
-
 NTSTATUS (WINAPI *func_RtlDosPathNameToNtPathName_U_WithStatus)
                (IN PCWSTR DosName,
                 OUT PUNICODE_STRING NtName,
@@ -478,20 +101,8 @@ NTSTATUS (WINAPI *func_RtlDosPathNameToNtPathName_U_WithStatus)
 NTSTATUS (WINAPI *func_RtlCreateSystemVolumeInformationFolder)
                (PCUNICODE_STRING VolumeRootPath);
 
-static OSVERSIONINFO windows_version_info = {
-       .dwOSVersionInfoSize = sizeof(OSVERSIONINFO),
-};
-
 static bool acquired_privileges = false;
 
-bool
-windows_version_is_at_least(unsigned major, unsigned minor)
-{
-       return windows_version_info.dwMajorVersion > major ||
-               (windows_version_info.dwMajorVersion == major &&
-                windows_version_info.dwMinorVersion >= minor);
-}
-
 struct dll_sym {
        void **func_ptr;
        const char *name;
@@ -512,21 +123,8 @@ struct dll_spec {
 struct dll_spec ntdll_spec = {
        .name = L"ntdll.dll",
        .syms = {
-               DLL_SYM(NtCreateFile, true),
-               DLL_SYM(NtOpenFile, true),
-               DLL_SYM(NtReadFile, true),
-               DLL_SYM(NtWriteFile, true),
-               DLL_SYM(NtQueryInformationFile, true),
-               DLL_SYM(NtQuerySecurityObject, true),
-               DLL_SYM(NtQueryDirectoryFile, true),
-               DLL_SYM(NtQueryVolumeInformationFile, true),
-               DLL_SYM(NtSetInformationFile, true),
-               DLL_SYM(NtSetSecurityObject, true),
-               DLL_SYM(NtFsControlFile, true),
-               DLL_SYM(NtClose, true),
-               DLL_SYM(RtlNtStatusToDosError, true),
                DLL_SYM(RtlCreateSystemVolumeInformationFolder, false),
-               DLL_SYM(RtlDosPathNameToNtPathName_U_WithStatus, true),
+               DLL_SYM(RtlDosPathNameToNtPathName_U_WithStatus, false), /* Not present on XP  */
                {NULL, NULL},
        },
 };
@@ -592,9 +190,6 @@ win32_global_init(int init_flags)
                acquired_privileges = true;
        }
 
-       /* Get Windows version information.  */
-       GetVersionEx(&windows_version_info);
-
        ret = init_dll(&ntdll_spec);
        if (ret)
                goto out_drop_privs;
@@ -609,10 +204,252 @@ out_drop_privs:
 void
 win32_global_cleanup(void)
 {
+       vss_global_cleanup();
+
        if (acquired_privileges)
                win32_release_capture_and_apply_privileges();
 
        cleanup_dll(&ntdll_spec);
 }
 
+/*
+ * Translates a Win32-namespace path into an NT-namespace path.
+ *
+ * On success, returns 0.  The NT-namespace path will be stored in the
+ * UNICODE_STRING structure pointed to by nt_path.  nt_path->Buffer will be set
+ * to a new buffer that must later be freed with HeapFree().  (Really
+ * RtlHeapFree(), but HeapFree() seems to be the same thing.)
+ *
+ * On failure, returns WIMLIB_ERR_NOMEM or WIMLIB_ERR_INVALID_PARAM.
+ */
+int
+win32_path_to_nt_path(const wchar_t *win32_path, UNICODE_STRING *nt_path)
+{
+       NTSTATUS status;
+
+       if (func_RtlDosPathNameToNtPathName_U_WithStatus) {
+               status = (*func_RtlDosPathNameToNtPathName_U_WithStatus)(win32_path,
+                                                                        nt_path,
+                                                                        NULL, NULL);
+       } else {
+               if (RtlDosPathNameToNtPathName_U(win32_path, nt_path, NULL, NULL))
+                       status = STATUS_SUCCESS;
+               else
+                       status = STATUS_NO_MEMORY;
+       }
+
+       if (likely(NT_SUCCESS(status)))
+               return 0;
+
+       if (status == STATUS_NO_MEMORY)
+               return WIMLIB_ERR_NOMEM;
+
+       winnt_error(status, L"\"%ls\": invalid path name", win32_path);
+       return WIMLIB_ERR_INVALID_PARAM;
+}
+
+int
+win32_get_drive_path(const wchar_t *file_path, wchar_t drive_path[7])
+{
+       tchar *file_abspath;
+
+       file_abspath = realpath(file_path, NULL);
+       if (!file_abspath)
+               return WIMLIB_ERR_NOMEM;
+
+       if (file_abspath[0] == L'\0' || file_abspath[1] != L':') {
+               ERROR("\"%ls\": Path format not recognized", file_abspath);
+               FREE(file_abspath);
+               return WIMLIB_ERR_UNSUPPORTED;
+       }
+
+       wsprintf(drive_path, L"\\\\.\\%lc:", file_abspath[0]);
+       FREE(file_abspath);
+       return 0;
+}
+
+/* Try to attach an instance of the Windows Overlay File System Filter Driver to
+ * the specified drive (such as C:)  */
+bool
+win32_try_to_attach_wof(const wchar_t *drive)
+{
+       HMODULE fltlib;
+       bool retval = false;
+
+       /* Use FilterAttach() from Fltlib.dll.  */
+
+       fltlib = LoadLibrary(L"Fltlib.dll");
+
+       if (!fltlib) {
+               WARNING("Failed to load Fltlib.dll");
+               return retval;
+       }
+
+       HRESULT (WINAPI *func_FilterAttach)(LPCWSTR lpFilterName,
+                                           LPCWSTR lpVolumeName,
+                                           LPCWSTR lpInstanceName,
+                                           DWORD dwCreatedInstanceNameLength,
+                                           LPWSTR lpCreatedInstanceName);
+
+       func_FilterAttach = (void *)GetProcAddress(fltlib, "FilterAttach");
+
+       if (func_FilterAttach) {
+               HRESULT res;
+
+               res = (*func_FilterAttach)(L"wof", drive, NULL, 0, NULL);
+
+               if (res != S_OK)
+                       res = (*func_FilterAttach)(L"wofadk", drive, NULL, 0, NULL);
+
+               if (res == S_OK)
+                       retval = true;
+       } else {
+               WARNING("FilterAttach() does not exist in Fltlib.dll");
+       }
+
+       FreeLibrary(fltlib);
+
+       return retval;
+}
+
+
+static void
+windows_msg(u32 code, const wchar_t *format, va_list va,
+           bool is_ntstatus, bool is_error)
+{
+       wchar_t _buf[STACK_MAX / 8];
+       wchar_t *buf = _buf;
+       size_t buflen = ARRAY_LEN(_buf);
+       size_t ret;
+       size_t n;
+
+retry:
+       n = vsnwprintf(buf, buflen, format, va);
+
+       if (n >= buflen)
+               goto realloc;
+
+       n += snwprintf(&buf[n], buflen - n,
+                      (is_ntstatus ?
+                       L" (status=%08"PRIx32"): " :
+                       L" (err=%"PRIu32"): "),
+                      code);
+
+       if (n >= buflen)
+               goto realloc;
+
+       ret = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
+                               FORMAT_MESSAGE_IGNORE_INSERTS |
+                               (is_ntstatus ? FORMAT_MESSAGE_FROM_HMODULE : 0),
+                           (is_ntstatus ? ntdll_spec.handle : NULL),
+                           code,
+                           MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+                           &buf[n],
+                           buflen - n,
+                           NULL);
+       n += ret;
+
+       if (n >= buflen || (ret == 0 && GetLastError() == ERROR_INSUFFICIENT_BUFFER))
+               goto realloc;
+
+        if (buf[n - 1] == L'\n')
+               buf[--n] = L'\0';
+        if (buf[n - 1] == L'\r')
+               buf[--n] = L'\0';
+        if (buf[n - 1] == L'.')
+               buf[--n] = L'\0';
+
+       if (is_error)
+               ERROR("%ls", buf);
+       else
+               WARNING("%ls", buf);
+       if (buf != _buf)
+               FREE(buf);
+       return;
+
+realloc:
+       if (buf != _buf)
+               FREE(buf);
+       buflen *= 2;
+       buf = MALLOC(buflen * sizeof(buf[0]));
+       if (buf)
+               goto retry;
+       ERROR("Ran out of memory while building error message!!!");
+}
+
+void
+win32_warning(DWORD err, const wchar_t *format, ...)
+{
+       va_list va;
+
+       va_start(va, format);
+       windows_msg(err, format, va, false, false);
+       va_end(va);
+}
+
+void
+win32_error(DWORD err, const wchar_t *format, ...)
+{
+       va_list va;
+
+       va_start(va, format);
+       windows_msg(err, format, va, false, true);
+       va_end(va);
+}
+
+void
+winnt_warning(NTSTATUS status, const wchar_t *format, ...)
+{
+       va_list va;
+
+       va_start(va, format);
+       windows_msg(status, format, va, true, false);
+       va_end(va);
+}
+
+void
+winnt_error(NTSTATUS status, const wchar_t *format, ...)
+{
+       va_list va;
+
+       va_start(va, format);
+       windows_msg(status, format, va, true, true);
+       va_end(va);
+}
+
+/*
+ * Synchronously execute a filesystem control method.  This is a wrapper around
+ * NtFsControlFile() that handles STATUS_PENDING.  Note that SYNCHRONIZE
+ * permission is, in general, required on the handle.
+ */
+NTSTATUS
+winnt_fsctl(HANDLE h, u32 code, const void *in, u32 in_size,
+           void *out, u32 out_size_avail, u32 *actual_out_size_ret)
+{
+       IO_STATUS_BLOCK iosb;
+       NTSTATUS status;
+
+       status = NtFsControlFile(h, NULL, NULL, NULL, &iosb, code,
+                                (void *)in, in_size, out, out_size_avail);
+       if (status == STATUS_PENDING) {
+               /* Beware: this case is often encountered with remote
+                * filesystems, but rarely with local filesystems.  */
+
+               status = NtWaitForSingleObject(h, FALSE, NULL);
+               if (NT_SUCCESS(status)) {
+                       status = iosb.Status;
+               } else {
+                       /* We shouldn't be issuing ioctls on a handle to which
+                        * we don't have SYNCHRONIZE access.  Otherwise we have
+                        * no way to wait for them to complete.  */
+                       wimlib_assert(status != STATUS_ACCESS_DENIED);
+               }
+       }
+
+       if (NT_SUCCESS(status) && actual_out_size_ret != NULL)
+               *actual_out_size_ret = (u32)iosb.Information;
+
+       return status;
+}
+
 #endif /* __WIN32__ */