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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_FileUtilsWin_h
#define mozilla_FileUtilsWin_h
#include <windows.h>
#include "mozilla/Scoped.h"
#include "nsString.h"
namespace mozilla {
inline bool EnsureLongPath(nsAString& aDosPath) {
nsAutoString inputPath(aDosPath);
while (true) {
DWORD requiredLength = GetLongPathNameW(
inputPath.get(), reinterpret_cast<wchar_t*>(aDosPath.BeginWriting()),
aDosPath.Length());
if (!requiredLength) {
return false;
}
if (requiredLength < aDosPath.Length()) {
// When GetLongPathNameW deems the last argument too small,
// it returns a value, but when you pass that value back, it's
// satisfied and returns a number that's one smaller. If the above
// check was == instead of <, the loop would go on forever with
// GetLongPathNameW returning oscillating values!
aDosPath.Truncate(requiredLength);
return true;
}
aDosPath.SetLength(requiredLength);
}
}
inline bool NtPathToDosPath(const nsAString& aNtPath, nsAString& aDosPath) {
aDosPath.Truncate();
if (aNtPath.IsEmpty()) {
return true;
}
constexpr auto symLinkPrefix = u"\\??\\"_ns;
uint32_t ntPathLen = aNtPath.Length();
uint32_t symLinkPrefixLen = symLinkPrefix.Length();
if (ntPathLen >= 6 && aNtPath.CharAt(5) == L':' &&
ntPathLen >= symLinkPrefixLen &&
Substring(aNtPath, 0, symLinkPrefixLen).Equals(symLinkPrefix)) {
// Symbolic link for DOS device. Just strip off the prefix.
aDosPath = aNtPath;
aDosPath.Cut(0, 4);
return true;
}
nsAutoString logicalDrives;
while (true) {
DWORD requiredLength = GetLogicalDriveStringsW(
logicalDrives.Length(),
reinterpret_cast<wchar_t*>(logicalDrives.BeginWriting()));
if (!requiredLength) {
return false;
}
if (requiredLength < logicalDrives.Length()) {
// When GetLogicalDriveStringsW deems the first argument too small,
// it returns a value, but when you pass that value back, it's
// satisfied and returns a number that's one smaller. If the above
// check was == instead of <, the loop would go on forever with
// GetLogicalDriveStringsW returning oscillating values!
logicalDrives.Truncate(requiredLength);
// logicalDrives now has the format "C:\\\0D:\\\0Z:\\\0". That is,
// the sequence drive letter, colon, backslash, U+0000 repeats.
break;
}
logicalDrives.SetLength(requiredLength);
}
const char16_t* cur = logicalDrives.BeginReading();
const char16_t* end = logicalDrives.EndReading();
nsString targetPath;
targetPath.SetLength(MAX_PATH);
wchar_t driveTemplate[] = L" :";
while (cur < end) {
// Unfortunately QueryDosDevice doesn't support the idiom for querying the
// output buffer size, so it may require retries.
driveTemplate[0] = *cur;
DWORD targetPathLen = 0;
SetLastError(ERROR_SUCCESS);
while (true) {
targetPathLen = QueryDosDeviceW(
driveTemplate, reinterpret_cast<wchar_t*>(targetPath.BeginWriting()),
targetPath.Length());
if (targetPathLen || GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
break;
}
targetPath.SetLength(targetPath.Length() * 2);
}
if (targetPathLen) {
// Need to use wcslen here because targetPath contains embedded NULL chars
size_t firstTargetPathLen = wcslen(targetPath.get());
const char16_t* pathComponent =
aNtPath.BeginReading() + firstTargetPathLen;
bool found = _wcsnicmp(char16ptr_t(aNtPath.BeginReading()),
targetPath.get(), firstTargetPathLen) == 0 &&
*pathComponent == L'\\';
if (found) {
aDosPath = driveTemplate;
aDosPath += pathComponent;
return EnsureLongPath(aDosPath);
}
}
// Find the next U+0000 within the logical string
while (*cur) {
// This loop skips the drive letter, the colon
// and the backslash.
cur++;
}
// Skip over the U+0000 that ends a drive entry
// within the logical string
cur++;
}
// Try to handle UNC paths. NB: This must happen after we've checked drive
// mappings in case a UNC path is mapped to a drive!
constexpr auto uncPrefix = u"\\\\"_ns;
constexpr auto deviceMupPrefix = u"\\Device\\Mup\\"_ns;
if (StringBeginsWith(aNtPath, deviceMupPrefix)) {
aDosPath = uncPrefix;
aDosPath += Substring(aNtPath, deviceMupPrefix.Length());
return true;
}
constexpr auto deviceLanmanRedirectorPrefix =
u"\\Device\\LanmanRedirector\\"_ns;
if (StringBeginsWith(aNtPath, deviceLanmanRedirectorPrefix)) {
aDosPath = uncPrefix;
aDosPath += Substring(aNtPath, deviceLanmanRedirectorPrefix.Length());
return true;
}
return false;
}
bool HandleToFilename(HANDLE aHandle, const LARGE_INTEGER& aOffset,
nsAString& aFilename);
} // namespace mozilla
#endif // mozilla_FileUtilsWin_h