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/logging.h>
26 #include <android-base/stringprintf.h>
27 #include <android-base/unique_fd.h>
28 #include <linux/fs.h>
29
30 namespace android {
31 namespace fs_mgr {
32
NibbleValue(const char & c,uint8_t * value)33 bool NibbleValue(const char& c, uint8_t* value) {
34 CHECK(value != nullptr);
35
36 switch (c) {
37 case '0' ... '9':
38 *value = c - '0';
39 break;
40 case 'a' ... 'f':
41 *value = c - 'a' + 10;
42 break;
43 case 'A' ... 'F':
44 *value = c - 'A' + 10;
45 break;
46 default:
47 return false;
48 }
49
50 return true;
51 }
52
HexToBytes(uint8_t * bytes,size_t bytes_len,const std::string & hex)53 bool HexToBytes(uint8_t* bytes, size_t bytes_len, const std::string& hex) {
54 CHECK(bytes != nullptr);
55
56 if (hex.size() % 2 != 0) {
57 return false;
58 }
59 if (hex.size() / 2 > bytes_len) {
60 return false;
61 }
62 for (size_t i = 0, j = 0, n = hex.size(); i < n; i += 2, ++j) {
63 uint8_t high;
64 if (!NibbleValue(hex[i], &high)) {
65 return false;
66 }
67 uint8_t low;
68 if (!NibbleValue(hex[i + 1], &low)) {
69 return false;
70 }
71 bytes[j] = (high << 4) | low;
72 }
73 return true;
74 }
75
BytesToHex(const uint8_t * bytes,size_t bytes_len)76 std::string BytesToHex(const uint8_t* bytes, size_t bytes_len) {
77 CHECK(bytes != nullptr);
78
79 static const char* hex_digits = "0123456789abcdef";
80 std::string hex;
81
82 for (size_t i = 0; i < bytes_len; i++) {
83 hex.push_back(hex_digits[(bytes[i] & 0xF0) >> 4]);
84 hex.push_back(hex_digits[bytes[i] & 0x0F]);
85 }
86 return hex;
87 }
88
89 // 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)90 bool WaitForFile(const std::string& filename, const std::chrono::milliseconds relative_timeout,
91 FileWaitMode file_wait_mode) {
92 auto start_time = std::chrono::steady_clock::now();
93
94 while (true) {
95 int rv = access(filename.c_str(), F_OK);
96 if (file_wait_mode == FileWaitMode::Exists) {
97 if (!rv || errno != ENOENT) return true;
98 } else if (file_wait_mode == FileWaitMode::DoesNotExist) {
99 if (rv && errno == ENOENT) return true;
100 }
101
102 std::this_thread::sleep_for(50ms);
103
104 auto now = std::chrono::steady_clock::now();
105 auto time_elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(now - start_time);
106 if (time_elapsed > relative_timeout) return false;
107 }
108 }
109
IsDeviceUnlocked()110 bool IsDeviceUnlocked() {
111 std::string verified_boot_state;
112
113 if (fs_mgr_get_boot_config("verifiedbootstate", &verified_boot_state)) {
114 return verified_boot_state == "orange";
115 }
116 return false;
117 }
118
SetBlockDeviceReadOnly(const std::string & blockdev)119 bool SetBlockDeviceReadOnly(const std::string& blockdev) {
120 android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(blockdev.c_str(), O_RDONLY | O_CLOEXEC)));
121 if (fd < 0) {
122 return false;
123 }
124
125 int ON = 1;
126 return ioctl(fd, BLKROSET, &ON) == 0;
127 }
128
ListFiles(const std::string & dir)129 Result<std::vector<std::string>> ListFiles(const std::string& dir) {
130 struct dirent* de;
131 std::vector<std::string> files;
132
133 std::unique_ptr<DIR, int (*)(DIR*)> dirp(opendir(dir.c_str()), closedir);
134 if (!dirp) {
135 return ErrnoError() << "Failed to opendir: " << dir;
136 }
137
138 while ((de = readdir(dirp.get()))) {
139 if (de->d_type != DT_REG) continue;
140 std::string full_path = android::base::StringPrintf("%s/%s", dir.c_str(), de->d_name);
141 files.emplace_back(std::move(full_path));
142 }
143
144 return files;
145 }
146
147 } // namespace fs_mgr
148 } // namespace android
149