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 <ctype.h>
18 #include <stdlib.h>
19 #include <sys/system_properties.h>
20
21 #include <iostream>
22
23 #include <android-base/properties.h>
24 #include <android-base/strings.h>
25
26 using android::base::SetProperty;
27 using android::base::StartsWith;
28
setprop_main(int argc,char ** argv)29 extern "C" int setprop_main(int argc, char** argv) {
30 if (argc != 3) {
31 std::cout << "usage: setprop NAME VALUE\n"
32 "\n"
33 "Sets an Android system property."
34 << std::endl;
35 return EXIT_FAILURE;
36 }
37
38 auto name = std::string{argv[1]};
39 auto value = std::string{argv[2]};
40
41 // SetProperty() doesn't tell us why it failed, and actually can't recognize most failures, so
42 // we duplicate some of init's checks here to help the user.
43
44 if (name.front() == '.' || name.back() == '.') {
45 std::cerr << "Property names must not start or end with a '.'" << std::endl;
46 return EXIT_FAILURE;
47 }
48
49 if (name.find("..") != std::string::npos) {
50 std::cerr << "'..' is not allowed in a property name" << std::endl;
51 return EXIT_FAILURE;
52 }
53
54 for (const auto& c : name) {
55 if (!isalnum(c) && !strchr(":@_.-", c)) {
56 std::cerr << "Invalid character '" << c << "' in name '" << name << "'" << std::endl;
57 return EXIT_FAILURE;
58 }
59 }
60
61 if (value.size() >= PROP_VALUE_MAX && !StartsWith(value, "ro.")) {
62 std::cerr << "Value '" << value << "' is too long, " << value.size()
63 << " bytes vs a max of " << PROP_VALUE_MAX << std::endl;
64 return EXIT_FAILURE;
65 }
66
67 if (mbstowcs(nullptr, value.data(), 0) == static_cast<std::size_t>(-1)) {
68 std::cerr << "Value '" << value << "' is not a UTF8 encoded string" << std::endl;
69 return EXIT_FAILURE;
70 }
71
72 if (!SetProperty(name, value)) {
73 std::cerr << "Failed to set property '" << name << "' to '" << value
74 << "'.\nSee dmesg for error reason." << std::endl;
75 return EXIT_FAILURE;
76 }
77
78 return EXIT_SUCCESS;
79 }