test_file_util_win.cc revision 5821806d5e7f356e8fa4b058a389a808ea183019 
1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "base/test/test_file_util.h"
6
7#include <aclapi.h>
8#include <shlwapi.h>
9#include <windows.h>
10
11#include <vector>
12
13#include "base/file_path.h"
14#include "base/file_util.h"
15#include "base/logging.h"
16#include "base/string_split.h"
17#include "base/win/scoped_handle.h"
18#include "base/threading/platform_thread.h"
19
20namespace file_util {
21
22static const ptrdiff_t kOneMB = 1024 * 1024;
23
24namespace {
25
26struct PermissionInfo {
27  PSECURITY_DESCRIPTOR security_descriptor;
28  ACL dacl;
29};
30
31// Deny |permission| on the file |path|, for the current user.
32bool DenyFilePermission(const FilePath& path, DWORD permission) {
33  PACL old_dacl;
34  PSECURITY_DESCRIPTOR security_descriptor;
35  if (GetNamedSecurityInfo(const_cast<wchar_t*>(path.value().c_str()),
36                           SE_FILE_OBJECT,
37                           DACL_SECURITY_INFORMATION, NULL, NULL, &old_dacl,
38                           NULL, &security_descriptor) != ERROR_SUCCESS) {
39    return false;
40  }
41
42  EXPLICIT_ACCESS change;
43  change.grfAccessPermissions = permission;
44  change.grfAccessMode = DENY_ACCESS;
45  change.grfInheritance = 0;
46  change.Trustee.pMultipleTrustee = NULL;
47  change.Trustee.MultipleTrusteeOperation = NO_MULTIPLE_TRUSTEE;
48  change.Trustee.TrusteeForm = TRUSTEE_IS_NAME;
49  change.Trustee.TrusteeType = TRUSTEE_IS_USER;
50  change.Trustee.ptstrName = L"CURRENT_USER";
51
52  PACL new_dacl;
53  if (SetEntriesInAcl(1, &change, old_dacl, &new_dacl) != ERROR_SUCCESS) {
54    LocalFree(security_descriptor);
55    return false;
56  }
57
58  DWORD rc = SetNamedSecurityInfo(const_cast<wchar_t*>(path.value().c_str()),
59                                  SE_FILE_OBJECT, DACL_SECURITY_INFORMATION,
60                                  NULL, NULL, new_dacl, NULL);
61  LocalFree(security_descriptor);
62  LocalFree(new_dacl);
63
64  return rc == ERROR_SUCCESS;
65}
66
67// Gets a blob indicating the permission information for |path|.
68// |length| is the length of the blob.  Zero on failure.
69// Returns the blob pointer, or NULL on failure.
70void* GetPermissionInfo(const FilePath& path, size_t* length) {
71  DCHECK(length != NULL);
72  *length = 0;
73  PACL dacl = NULL;
74  PSECURITY_DESCRIPTOR security_descriptor;
75  if (GetNamedSecurityInfo(const_cast<wchar_t*>(path.value().c_str()),
76                           SE_FILE_OBJECT,
77                           DACL_SECURITY_INFORMATION, NULL, NULL, &dacl,
78                           NULL, &security_descriptor) != ERROR_SUCCESS) {
79    return NULL;
80  }
81  DCHECK(dacl != NULL);
82
83  *length = sizeof(PSECURITY_DESCRIPTOR) + dacl->AclSize;
84  PermissionInfo* info = reinterpret_cast<PermissionInfo*>(new char[*length]);
85  info->security_descriptor = security_descriptor;
86  memcpy(&info->dacl, dacl, dacl->AclSize);
87
88  return info;
89}
90
91// Restores the permission information for |path|, given the blob retrieved
92// using |GetPermissionInfo()|.
93// |info| is the pointer to the blob.
94// |length| is the length of the blob.
95// Either |info| or |length| may be NULL/0, in which case nothing happens.
96bool RestorePermissionInfo(const FilePath& path, void* info, size_t length) {
97  if (!info || !length)
98    return false;
99
100  PermissionInfo* perm = reinterpret_cast<PermissionInfo*>(info);
101
102  DWORD rc = SetNamedSecurityInfo(const_cast<wchar_t*>(path.value().c_str()),
103                                  SE_FILE_OBJECT, DACL_SECURITY_INFORMATION,
104                                  NULL, NULL, &perm->dacl, NULL);
105  LocalFree(perm->security_descriptor);
106
107  char* char_array = reinterpret_cast<char*>(info);
108  delete [] char_array;
109
110  return rc == ERROR_SUCCESS;
111}
112
113}  // namespace
114
115bool DieFileDie(const FilePath& file, bool recurse) {
116  // It turns out that to not induce flakiness a long timeout is needed.
117  const int kIterations = 25;
118  const base::TimeDelta kTimeout = base::TimeDelta::FromSeconds(10) /
119                                   kIterations;
120
121  if (!file_util::PathExists(file))
122    return true;
123
124  // Sometimes Delete fails, so try a few more times. Divide the timeout
125  // into short chunks, so that if a try succeeds, we won't delay the test
126  // for too long.
127  for (int i = 0; i < kIterations; ++i) {
128    if (file_util::Delete(file, recurse))
129      return true;
130    base::PlatformThread::Sleep(kTimeout);
131  }
132  return false;
133}
134
135bool EvictFileFromSystemCache(const FilePath& file) {
136  // Request exclusive access to the file and overwrite it with no buffering.
137  base::win::ScopedHandle file_handle(
138      CreateFile(file.value().c_str(), GENERIC_READ | GENERIC_WRITE, 0, NULL,
139                 OPEN_EXISTING, FILE_FLAG_NO_BUFFERING, NULL));
140  if (!file_handle)
141    return false;
142
143  // Get some attributes to restore later.
144  BY_HANDLE_FILE_INFORMATION bhi = {0};
145  CHECK(::GetFileInformationByHandle(file_handle, &bhi));
146
147  // Execute in chunks. It could be optimized. We want to do few of these since
148  // these operations will be slow without the cache.
149
150  // Allocate a buffer for the reads and the writes.
151  char* buffer = reinterpret_cast<char*>(VirtualAlloc(NULL,
152                                                      kOneMB,
153                                                      MEM_COMMIT | MEM_RESERVE,
154                                                      PAGE_READWRITE));
155
156  // If the file size isn't a multiple of kOneMB, we'll need special
157  // processing.
158  bool file_is_aligned = true;
159  int total_bytes = 0;
160  DWORD bytes_read, bytes_written;
161  for (;;) {
162    bytes_read = 0;
163    ::ReadFile(file_handle, buffer, kOneMB, &bytes_read, NULL);
164    if (bytes_read == 0)
165      break;
166
167    if (bytes_read < kOneMB) {
168      // Zero out the remaining part of the buffer.
169      // WriteFile will fail if we provide a buffer size that isn't a
170      // sector multiple, so we'll have to write the entire buffer with
171      // padded zeros and then use SetEndOfFile to truncate the file.
172      ZeroMemory(buffer + bytes_read, kOneMB - bytes_read);
173      file_is_aligned = false;
174    }
175
176    // Move back to the position we just read from.
177    // Note that SetFilePointer will also fail if total_bytes isn't sector
178    // aligned, but that shouldn't happen here.
179    DCHECK((total_bytes % kOneMB) == 0);
180    SetFilePointer(file_handle, total_bytes, NULL, FILE_BEGIN);
181    if (!::WriteFile(file_handle, buffer, kOneMB, &bytes_written, NULL) ||
182        bytes_written != kOneMB) {
183      BOOL freed = VirtualFree(buffer, 0, MEM_RELEASE);
184      DCHECK(freed);
185      NOTREACHED();
186      return false;
187    }
188
189    total_bytes += bytes_read;
190
191    // If this is false, then we just processed the last portion of the file.
192    if (!file_is_aligned)
193      break;
194  }
195
196  BOOL freed = VirtualFree(buffer, 0, MEM_RELEASE);
197  DCHECK(freed);
198
199  if (!file_is_aligned) {
200    // The size of the file isn't a multiple of 1 MB, so we'll have
201    // to open the file again, this time without the FILE_FLAG_NO_BUFFERING
202    // flag and use SetEndOfFile to mark EOF.
203    file_handle.Set(NULL);
204    file_handle.Set(CreateFile(file.value().c_str(), GENERIC_WRITE, 0, NULL,
205                               OPEN_EXISTING, 0, NULL));
206    CHECK_NE(SetFilePointer(file_handle, total_bytes, NULL, FILE_BEGIN),
207             INVALID_SET_FILE_POINTER);
208    CHECK(::SetEndOfFile(file_handle));
209  }
210
211  // Restore the file attributes.
212  CHECK(::SetFileTime(file_handle, &bhi.ftCreationTime, &bhi.ftLastAccessTime,
213                      &bhi.ftLastWriteTime));
214
215  return true;
216}
217
218// Like CopyFileNoCache but recursively copies all files and subdirectories
219// in the given input directory to the output directory.
220bool CopyRecursiveDirNoCache(const FilePath& source_dir,
221                             const FilePath& dest_dir) {
222  // Try to create the directory if it doesn't already exist.
223  if (!CreateDirectory(dest_dir)) {
224    if (GetLastError() != ERROR_ALREADY_EXISTS)
225      return false;
226  }
227
228  std::vector<std::wstring> files_copied;
229
230  FilePath src(source_dir.AppendASCII("*"));
231
232  WIN32_FIND_DATA fd;
233  HANDLE fh = FindFirstFile(src.value().c_str(), &fd);
234  if (fh == INVALID_HANDLE_VALUE)
235    return false;
236
237  do {
238    std::wstring cur_file(fd.cFileName);
239    if (cur_file == L"." || cur_file == L"..")
240      continue;  // Skip these special entries.
241
242    FilePath cur_source_path = source_dir.Append(cur_file);
243    FilePath cur_dest_path = dest_dir.Append(cur_file);
244
245    if (fd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
246      // Recursively copy a subdirectory. We stripped "." and ".." already.
247      if (!CopyRecursiveDirNoCache(cur_source_path, cur_dest_path)) {
248        FindClose(fh);
249        return false;
250      }
251    } else {
252      // Copy the file.
253      if (!::CopyFile(cur_source_path.value().c_str(),
254                      cur_dest_path.value().c_str(), false)) {
255        FindClose(fh);
256        return false;
257      }
258
259      // We don't check for errors from this function, often, we are copying
260      // files that are in the repository, and they will have read-only set.
261      // This will prevent us from evicting from the cache, but these don't
262      // matter anyway.
263      EvictFileFromSystemCache(cur_dest_path);
264    }
265  } while (FindNextFile(fh, &fd));
266
267  FindClose(fh);
268  return true;
269}
270
271// Checks if the volume supports Alternate Data Streams. This is required for
272// the Zone Identifier implementation.
273bool VolumeSupportsADS(const FilePath& path) {
274  wchar_t drive[MAX_PATH] = {0};
275  wcscpy_s(drive, MAX_PATH, path.value().c_str());
276
277  if (!PathStripToRootW(drive))
278    return false;
279
280  DWORD fs_flags = 0;
281  if (!GetVolumeInformationW(drive, NULL, 0, 0, NULL, &fs_flags, NULL, 0))
282    return false;
283
284  if (fs_flags & FILE_NAMED_STREAMS)
285    return true;
286
287  return false;
288}
289
290// Return whether the ZoneIdentifier is correctly set to "Internet" (3)
291// Only returns a valid result when called from same process as the
292// one that (was supposed to have) set the zone identifier.
293bool HasInternetZoneIdentifier(const FilePath& full_path) {
294  FilePath zone_path(full_path.value() + L":Zone.Identifier");
295  std::string zone_path_contents;
296  if (!file_util::ReadFileToString(zone_path, &zone_path_contents))
297    return false;
298
299  std::vector<std::string> lines;
300  // This call also trims whitespaces, including carriage-returns (\r).
301  base::SplitString(zone_path_contents, '\n', &lines);
302
303  switch (lines.size()) {
304    case 3:
305      // optional empty line at end of file:
306      if (lines[2] != "")
307        return false;
308      // fall through:
309    case 2:
310      return lines[0] == "[ZoneTransfer]" && lines[1] == "ZoneId=3";
311    default:
312      return false;
313  }
314}
315
316std::wstring FilePathAsWString(const FilePath& path) {
317  return path.value();
318}
319FilePath WStringAsFilePath(const std::wstring& path) {
320  return FilePath(path);
321}
322
323bool MakeFileUnreadable(const FilePath& path) {
324  return DenyFilePermission(path, GENERIC_READ);
325}
326
327bool MakeFileUnwritable(const FilePath& path) {
328  return DenyFilePermission(path, GENERIC_WRITE);
329}
330
331PermissionRestorer::PermissionRestorer(const FilePath& path)
332    : path_(path), info_(NULL), length_(0) {
333  info_ = GetPermissionInfo(path_, &length_);
334  DCHECK(info_ != NULL);
335  DCHECK_NE(0u, length_);
336}
337
338PermissionRestorer::~PermissionRestorer() {
339  if (!RestorePermissionInfo(path_, info_, length_))
340    NOTREACHED();
341}
342
343}  // namespace file_util
344