1 /*
2 * Copyright (C) 2023 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 "./string-utils.h"
18
19 #include <errno.h>
20 #include <stdlib.h>
21 #include <string.h>
22
23 namespace shell_as {
24
StringToUInt32(const char * s,uint32_t * i)25 bool StringToUInt32(const char* s, uint32_t* i) {
26 uint64_t value = 0;
27 if (!StringToUInt64(s, &value)) {
28 return false;
29 }
30 if (value > UINT_MAX) {
31 return false;
32 }
33 *i = value;
34 return true;
35 }
36
StringToUInt64(const char * s,uint64_t * i)37 bool StringToUInt64(const char* s, uint64_t* i) {
38 char* endptr = nullptr;
39 // Reset errno to a non-error value since strtoul does not clear errno.
40 errno = 0;
41 *i = strtoul(s, &endptr, 10);
42 // strtoul will return 0 if the value cannot be parsed as an unsigned long. If
43 // this occurs, ensure that the ID actually was zero. This is done by ensuring
44 // that the end pointer was advanced and that it now points to the end of the
45 // string (a null byte).
46 return errno == 0 && (*i != 0 || (endptr != s && *endptr == '\0'));
47 }
48
SplitIdsAndSkip(char * line,const char * separators,int num_to_skip,std::vector<uid_t> * ids)49 bool SplitIdsAndSkip(char* line, const char* separators, int num_to_skip,
50 std::vector<uid_t>* ids) {
51 if (line == nullptr) {
52 return false;
53 }
54
55 ids->clear();
56 for (char* id_string = strtok(line, separators); id_string != nullptr;
57 id_string = strtok(nullptr, separators)) {
58 if (num_to_skip > 0) {
59 num_to_skip--;
60 continue;
61 }
62
63 gid_t id;
64 if (!StringToUInt32(id_string, &id)) {
65 return false;
66 }
67 ids->push_back(id);
68 }
69 return true;
70 }
71
72 } // namespace shell_as
73