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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/test/test_file_util.h"
#include <windows.h>
#include <aclapi.h>
#include <shlwapi.h>
#include <stddef.h>
#include <vector>
#include "base/files/file_path.h"
#include "base/files/file_util.h"
#include "base/logging.h"
#include "base/strings/string_split.h"
#include "base/threading/platform_thread.h"
#include "base/win/scoped_handle.h"
namespace base {
namespace {
struct PermissionInfo {
PSECURITY_DESCRIPTOR security_descriptor;
ACL dacl;
};
// Deny |permission| on the file |path|, for the current user.
bool DenyFilePermission(const FilePath& path, DWORD permission) {
PACL old_dacl;
PSECURITY_DESCRIPTOR security_descriptor;
if (GetNamedSecurityInfo(const_cast<wchar_t*>(path.value().c_str()),
SE_FILE_OBJECT,
DACL_SECURITY_INFORMATION, NULL, NULL, &old_dacl,
NULL, &security_descriptor) != ERROR_SUCCESS) {
return false;
}
EXPLICIT_ACCESS change;
change.grfAccessPermissions = permission;
change.grfAccessMode = DENY_ACCESS;
change.grfInheritance = 0;
change.Trustee.pMultipleTrustee = NULL;
change.Trustee.MultipleTrusteeOperation = NO_MULTIPLE_TRUSTEE;
change.Trustee.TrusteeForm = TRUSTEE_IS_NAME;
change.Trustee.TrusteeType = TRUSTEE_IS_USER;
change.Trustee.ptstrName = const_cast<wchar_t*>(L"CURRENT_USER");
PACL new_dacl;
if (SetEntriesInAcl(1, &change, old_dacl, &new_dacl) != ERROR_SUCCESS) {
LocalFree(security_descriptor);
return false;
}
DWORD rc = SetNamedSecurityInfo(const_cast<wchar_t*>(path.value().c_str()),
SE_FILE_OBJECT, DACL_SECURITY_INFORMATION,
NULL, NULL, new_dacl, NULL);
LocalFree(security_descriptor);
LocalFree(new_dacl);
return rc == ERROR_SUCCESS;
}
// Gets a blob indicating the permission information for |path|.
// |length| is the length of the blob. Zero on failure.
// Returns the blob pointer, or NULL on failure.
void* GetPermissionInfo(const FilePath& path, size_t* length) {
DCHECK(length != NULL);
*length = 0;
PACL dacl = NULL;
PSECURITY_DESCRIPTOR security_descriptor;
if (GetNamedSecurityInfo(const_cast<wchar_t*>(path.value().c_str()),
SE_FILE_OBJECT,
DACL_SECURITY_INFORMATION, NULL, NULL, &dacl,
NULL, &security_descriptor) != ERROR_SUCCESS) {
return NULL;
}
DCHECK(dacl != NULL);
*length = sizeof(PSECURITY_DESCRIPTOR) + dacl->AclSize;
PermissionInfo* info = reinterpret_cast<PermissionInfo*>(new char[*length]);
info->security_descriptor = security_descriptor;
memcpy(&info->dacl, dacl, dacl->AclSize);
return info;
}
// Restores the permission information for |path|, given the blob retrieved
// using |GetPermissionInfo()|.
// |info| is the pointer to the blob.
// |length| is the length of the blob.
// Either |info| or |length| may be NULL/0, in which case nothing happens.
bool RestorePermissionInfo(const FilePath& path, void* info, size_t length) {
if (!info || !length)
return false;
PermissionInfo* perm = reinterpret_cast<PermissionInfo*>(info);
DWORD rc = SetNamedSecurityInfo(const_cast<wchar_t*>(path.value().c_str()),
SE_FILE_OBJECT, DACL_SECURITY_INFORMATION,
NULL, NULL, &perm->dacl, NULL);
LocalFree(perm->security_descriptor);
char* char_array = reinterpret_cast<char*>(info);
delete [] char_array;
return rc == ERROR_SUCCESS;
}
} // namespace
bool DieFileDie(const FilePath& file, bool recurse) {
// It turns out that to not induce flakiness a long timeout is needed.
const int kIterations = 25;
const TimeDelta kTimeout = TimeDelta::FromSeconds(10) / kIterations;
if (!PathExists(file))
return true;
// Sometimes Delete fails, so try a few more times. Divide the timeout
// into short chunks, so that if a try succeeds, we won't delay the test
// for too long.
for (int i = 0; i < kIterations; ++i) {
if (DeleteFile(file, recurse))
return true;
PlatformThread::Sleep(kTimeout);
}
return false;
}
bool EvictFileFromSystemCache(const FilePath& file) {
base::win::ScopedHandle file_handle(
CreateFile(file.value().c_str(), GENERIC_READ | GENERIC_WRITE, 0, NULL,
OPEN_EXISTING, FILE_FLAG_NO_BUFFERING, NULL));
if (!file_handle.IsValid())
return false;
// Re-write the file time information to trigger cache eviction for the file.
// This function previously overwrote the entire file without buffering, but
// local experimentation validates this simplified and *much* faster approach:
// [1] Sysinternals RamMap no longer lists these files as cached afterwards.
// [2] Telemetry performance test startup.cold.blank_page reports sane values.
BY_HANDLE_FILE_INFORMATION bhi = {0};
CHECK(::GetFileInformationByHandle(file_handle.Get(), &bhi));
CHECK(::SetFileTime(file_handle.Get(), &bhi.ftCreationTime,
&bhi.ftLastAccessTime, &bhi.ftLastWriteTime));
return true;
}
// Checks if the volume supports Alternate Data Streams. This is required for
// the Zone Identifier implementation.
bool VolumeSupportsADS(const FilePath& path) {
wchar_t drive[MAX_PATH] = {0};
wcscpy_s(drive, MAX_PATH, path.value().c_str());
if (!PathStripToRootW(drive))
return false;
DWORD fs_flags = 0;
if (!GetVolumeInformationW(drive, NULL, 0, 0, NULL, &fs_flags, NULL, 0))
return false;
if (fs_flags & FILE_NAMED_STREAMS)
return true;
return false;
}
// Return whether the ZoneIdentifier is correctly set to "Internet" (3)
// Only returns a valid result when called from same process as the
// one that (was supposed to have) set the zone identifier.
bool HasInternetZoneIdentifier(const FilePath& full_path) {
FilePath zone_path(full_path.value() + L":Zone.Identifier");
std::string zone_path_contents;
if (!ReadFileToString(zone_path, &zone_path_contents))
return false;
std::vector<std::string> lines = SplitString(
zone_path_contents, "\n", TRIM_WHITESPACE, SPLIT_WANT_ALL);
switch (lines.size()) {
case 3:
// optional empty line at end of file:
if (!lines[2].empty())
return false;
// fall through:
case 2:
return lines[0] == "[ZoneTransfer]" && lines[1] == "ZoneId=3";
default:
return false;
}
}
bool MakeFileUnreadable(const FilePath& path) {
return DenyFilePermission(path, GENERIC_READ);
}
bool MakeFileUnwritable(const FilePath& path) {
return DenyFilePermission(path, GENERIC_WRITE);
}
FilePermissionRestorer::FilePermissionRestorer(const FilePath& path)
: path_(path), info_(NULL), length_(0) {
info_ = GetPermissionInfo(path_, &length_);
DCHECK(info_ != NULL);
DCHECK_NE(0u, length_);
}
FilePermissionRestorer::~FilePermissionRestorer() {
if (!RestorePermissionInfo(path_, info_, length_))
NOTREACHED();
}
} // namespace base
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