chrome/browser/profiles/file_path_verifier_win.cc

   1 // Copyright 2013 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 "chrome/browser/profiles/file_path_verifier_win.h"
   6
   7 #include <windows.h>
   8
   9 #include "base/files/file_path.h"
  10 #include "base/files/file_util.h"
  11 #include "base/metrics/histogram.h"
  12 #include "chrome_elf/create_file/chrome_create_file.h"
  13
  14 namespace {
  15
  16 // This enum is used in UMA histograms and should never be re-ordered.
  17 enum FileVerificationResult {
  18   FILE_VERIFICATION_SUCCESS,
  19   FILE_VERIFICATION_FILE_NOT_FOUND,
  20   FILE_VERIFICATION_INTERNAL_ERROR,
  21   FILE_VERIFICATION_FAILED_UNKNOWN,
  22   FILE_VERIFICATION_FAILED_SAMEBASE,
  23   FILE_VERIFICATION_FAILED_SAMEDIR,
  24   FILE_VERIFICATION_SUCCESS_REDIRECT,
  25   FILE_VERIFICATION_FAILED_SAMEBASE_REDIRECT,
  26   FILE_VERIFICATION_FAILED_SAMEDIR_REDIRECT,
  27   NUM_FILE_VERIFICATION_RESULTS
  28 };
  29
  30 // Returns a FileVerificationResult based on the state of |file| on disk.
  31 FileVerificationResult VerifyFileAtPath(const base::FilePath& file) {
  32   FileVerificationResult file_verification_result =
  33       FILE_VERIFICATION_FAILED_UNKNOWN;
  34   base::FilePath normalized_path;
  35   int redirect_count_before = ::GetRedirectCount();
  36   if (!base::NormalizeFilePath(file, &normalized_path)) {
  37     if (::GetLastError() == ERROR_FILE_NOT_FOUND)
  38       file_verification_result = FILE_VERIFICATION_FILE_NOT_FOUND;
  39     else
  40       file_verification_result = FILE_VERIFICATION_INTERNAL_ERROR;
  41   } else {
  42     internal::PathComparisonReason path_comparison_reason =
  43         internal::ComparePathsIgnoreCase(file, normalized_path);
  44     // GetRedirectCount() tracks the number of CreateFile() calls that were
  45     // redirected. If it has increased then the CreateFile() call made by
  46     // base::NormalizeFilePath() was redirected.
  47     bool was_redirected = ::GetRedirectCount() > redirect_count_before;
  48     switch (path_comparison_reason) {
  49       case internal::PATH_COMPARISON_EQUAL:
  50         file_verification_result = was_redirected ?
  51             FILE_VERIFICATION_SUCCESS_REDIRECT : FILE_VERIFICATION_SUCCESS;
  52         break;
  53       case internal::PATH_COMPARISON_FAILED_SAMEBASE:
  54         file_verification_result = was_redirected ?
  55             FILE_VERIFICATION_FAILED_SAMEBASE_REDIRECT :
  56             FILE_VERIFICATION_FAILED_SAMEBASE;
  57         break;
  58       case internal::PATH_COMPARISON_FAILED_SAMEDIR:
  59         file_verification_result = was_redirected ?
  60             FILE_VERIFICATION_FAILED_SAMEDIR_REDIRECT :
  61             FILE_VERIFICATION_FAILED_SAMEDIR;
  62         break;
  63       case internal::PATH_COMPARISON_FAILED_UNKNOWN:
  64         // file_verification_result was initialized to the right value above.
  65         DCHECK_EQ(FILE_VERIFICATION_FAILED_UNKNOWN, file_verification_result);
  66         break;
  67     }
  68   }
  69   return file_verification_result;
  70 }
  71
  72 }  // namespace
  73
  74 namespace internal {
  75
  76 PathComparisonReason ComparePathsIgnoreCase(const base::FilePath& path1,
  77                                             const base::FilePath& path2) {
  78   PathComparisonReason reason = PATH_COMPARISON_FAILED_UNKNOWN;
  79
  80   if (base::FilePath::CompareEqualIgnoreCase(path1.value(), path2.value())) {
  81     reason = PATH_COMPARISON_EQUAL;
  82   } else if (base::FilePath::CompareEqualIgnoreCase(path1.BaseName().value(),
  83                                                     path2.BaseName().value())) {
  84     reason = PATH_COMPARISON_FAILED_SAMEBASE;
  85   } else if (base::FilePath::CompareEqualIgnoreCase(path1.DirName().value(),
  86                                                     path2.DirName().value())) {
  87     reason = PATH_COMPARISON_FAILED_SAMEDIR;
  88   }
  89
  90   return reason;
  91 }
  92
  93 }  // namespace internal
  94
  95 void VerifyPreferencesFile(const base::FilePath& pref_file_path) {
  96   FileVerificationResult file_verification_result =
  97       VerifyFileAtPath(pref_file_path);
  98   UMA_HISTOGRAM_ENUMERATION("Stability.FileAtPath.Preferences",
  99                             file_verification_result,
 100                             NUM_FILE_VERIFICATION_RESULTS);
 101 }