base/test/test_file_util_win.cc

   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
  20 namespace file_util {
  21
  22 static const ptrdiff_t kOneMB = 1024 * 1024;
  23
  24 namespace {
  25
  26 struct PermissionInfo {
  27   PSECURITY_DESCRIPTOR security_descriptor;
  28   ACL dacl;
  29 };
  30
  31 // Deny |permission| on the file |path|, for the current user.
  32 bool 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.
  70 void* 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.
  96 bool 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
 115 bool 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
 135 bool 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.
 220 bool 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.
 273 bool 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.
 293 bool 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
 316 std::wstring FilePathAsWString(const FilePath& path) {
 317   return path.value();
 318 }
 319 FilePath WStringAsFilePath(const std::wstring& path) {
 320   return FilePath(path);
 321 }
 322
 323 bool MakeFileUnreadable(const FilePath& path) {
 324   return DenyFilePermission(path, GENERIC_READ);
 325 }
 326
 327 bool MakeFileUnwritable(const FilePath& path) {
 328   return DenyFilePermission(path, GENERIC_WRITE);
 329 }
 330
 331 PermissionRestorer::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
 338 PermissionRestorer::~PermissionRestorer() {
 339   if (!RestorePermissionInfo(path_, info_, length_))
 340     NOTREACHED();
 341 }
 342
 343 }  // namespace file_util