1 // Copyright 2017 The Chromium OS 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 "policy/resilient_policy_util.h"
6 
7 #include <algorithm>
8 
9 #include <base/files/file_enumerator.h>
10 #include <base/files/file_util.h>
11 #include <base/strings/string_number_conversions.h>
12 #include <base/strings/string_util.h>
13 
14 namespace policy {
15 
16 std::map<int, base::FilePath> GetSortedResilientPolicyFilePaths(
17     const base::FilePath& default_policy_path) {
18   std::map<int, base::FilePath> sorted_policy_file_paths;
19   base::FilePath directory = default_policy_path.DirName();
20   if (!base::PathExists(directory))
21     return sorted_policy_file_paths;
22 
23   // Iterate the list of files in the folder, identifying the policy files based
24   // on the name. Store in the map the absolute paths.
25   const std::string default_policy_file_name =
26       default_policy_path.BaseName().value();
27   base::FileEnumerator file_iter(directory, false, base::FileEnumerator::FILES);
28   for (base::FilePath child_file = file_iter.Next(); !child_file.empty();
29        child_file = file_iter.Next()) {
30     int index;
31     if (ParseResilientPolicyFilePath(child_file, default_policy_path, &index)) {
32       sorted_policy_file_paths[index] = child_file;
33     }
34   }
35 
36   return sorted_policy_file_paths;
37 }
38 
39 bool ParseResilientPolicyFilePath(const base::FilePath& policy_path,
40                                   const base::FilePath& default_policy_path,
41                                   int* index_out) {
42   if (!base::StartsWith(policy_path.value(), default_policy_path.value(),
43                         base::CompareCase::SENSITIVE)) {
44     return false;
45   }
46 
47   if (policy_path == default_policy_path) {
48     *index_out = 0;
49     return true;
50   }
51 
52   const std::string extension =
53       policy_path.value().substr(default_policy_path.value().size());
54   if (extension.empty() || extension[0] != '.' ||
55       !base::StringToInt(extension.substr(1), index_out) || *index_out <= 0) {
56     return false;
57   }
58 
59   return true;
60 }
61 
62 base::FilePath GetResilientPolicyFilePathForIndex(
63     const base::FilePath& default_policy_path,
64     int index) {
65   if (index == 0)
66     return default_policy_path;
67   return base::FilePath(default_policy_path.value() + "." +
68                         std::to_string(index));
69 }
70 
71 }  // namespace policy
72