1 /*
2 * Copyright (C) 2019 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "util.h"
18
19 #include <dirent.h>
20 #include <sys/ioctl.h>
21 #include <sys/types.h>
22
23 #include <thread>
24
25 #include <android-base/stringprintf.h>
26 #include <android-base/unique_fd.h>
27 #include <linux/fs.h>
28
29 namespace android {
30 namespace fs_mgr {
31
NibbleValue(const char & c,uint8_t * value)32 bool NibbleValue(const char& c, uint8_t* value) {
33 CHECK(value != nullptr);
34
35 switch (c) {
36 case '0' ... '9':
37 *value = c - '0';
38 break;
39 case 'a' ... 'f':
40 *value = c - 'a' + 10;
41 break;
42 case 'A' ... 'F':
43 *value = c - 'A' + 10;
44 break;
45 default:
46 return false;
47 }
48
49 return true;
50 }
51
HexToBytes(uint8_t * bytes,size_t bytes_len,const std::string & hex)52 bool HexToBytes(uint8_t* bytes, size_t bytes_len, const std::string& hex) {
53 CHECK(bytes != nullptr);
54
55 if (hex.size() % 2 != 0) {
56 return false;
57 }
58 if (hex.size() / 2 > bytes_len) {
59 return false;
60 }
61 for (size_t i = 0, j = 0, n = hex.size(); i < n; i += 2, ++j) {
62 uint8_t high;
63 if (!NibbleValue(hex[i], &high)) {
64 return false;
65 }
66 uint8_t low;
67 if (!NibbleValue(hex[i + 1], &low)) {
68 return false;
69 }
70 bytes[j] = (high << 4) | low;
71 }
72 return true;
73 }
74
BytesToHex(const uint8_t * bytes,size_t bytes_len)75 std::string BytesToHex(const uint8_t* bytes, size_t bytes_len) {
76 CHECK(bytes != nullptr);
77
78 static const char* hex_digits = "0123456789abcdef";
79 std::string hex;
80
81 for (size_t i = 0; i < bytes_len; i++) {
82 hex.push_back(hex_digits[(bytes[i] & 0xF0) >> 4]);
83 hex.push_back(hex_digits[bytes[i] & 0x0F]);
84 }
85 return hex;
86 }
87
88 // TODO: remove duplicate code with fs_mgr_wait_for_file
WaitForFile(const std::string & filename,const std::chrono::milliseconds relative_timeout,FileWaitMode file_wait_mode)89 bool WaitForFile(const std::string& filename, const std::chrono::milliseconds relative_timeout,
90 FileWaitMode file_wait_mode) {
91 auto start_time = std::chrono::steady_clock::now();
92
93 while (true) {
94 int rv = access(filename.c_str(), F_OK);
95 if (file_wait_mode == FileWaitMode::Exists) {
96 if (!rv || errno != ENOENT) return true;
97 } else if (file_wait_mode == FileWaitMode::DoesNotExist) {
98 if (rv && errno == ENOENT) return true;
99 }
100
101 std::this_thread::sleep_for(50ms);
102
103 auto now = std::chrono::steady_clock::now();
104 auto time_elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(now - start_time);
105 if (time_elapsed > relative_timeout) return false;
106 }
107 }
108
IsDeviceUnlocked()109 bool IsDeviceUnlocked() {
110 std::string verified_boot_state;
111
112 if (fs_mgr_get_boot_config("verifiedbootstate", &verified_boot_state)) {
113 return verified_boot_state == "orange";
114 }
115 return false;
116 }
117
SetBlockDeviceReadOnly(const std::string & blockdev)118 bool SetBlockDeviceReadOnly(const std::string& blockdev) {
119 android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(blockdev.c_str(), O_RDONLY | O_CLOEXEC)));
120 if (fd < 0) {
121 return false;
122 }
123
124 int ON = 1;
125 return ioctl(fd, BLKROSET, &ON) == 0;
126 }
127
ListFiles(const std::string & dir)128 Result<std::vector<std::string>> ListFiles(const std::string& dir) {
129 struct dirent* de;
130 std::vector<std::string> files;
131
132 std::unique_ptr<DIR, int (*)(DIR*)> dirp(opendir(dir.c_str()), closedir);
133 if (!dirp) {
134 return ErrnoError() << "Failed to opendir: " << dir;
135 }
136
137 while ((de = readdir(dirp.get()))) {
138 if (de->d_type != DT_REG) continue;
139 std::string full_path = android::base::StringPrintf("%s/%s", dir.c_str(), de->d_name);
140 files.emplace_back(std::move(full_path));
141 }
142
143 return files;
144 }
145
146 } // namespace fs_mgr
147 } // namespace android
148