Mårten Kongstad | 2503a49 | 2018-09-27 13:32:30 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2018 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 | #ifdef _WIN32 |
| 18 | // nothing to see here |
| 19 | #else |
| 20 | #include <memory> |
| 21 | #include <string> |
| 22 | #include <vector> |
| 23 | |
| 24 | #include <sys/types.h> |
| 25 | #include <sys/wait.h> |
| 26 | #include <unistd.h> |
| 27 | |
| 28 | #include "android-base/logging.h" |
| 29 | |
| 30 | #include "androidfw/PosixUtils.h" |
| 31 | |
| 32 | namespace { |
| 33 | |
| 34 | std::unique_ptr<std::string> ReadFile(int fd) { |
| 35 | std::unique_ptr<std::string> str(new std::string()); |
| 36 | char buf[1024]; |
| 37 | ssize_t r; |
| 38 | while ((r = read(fd, buf, sizeof(buf))) > 0) { |
| 39 | str->append(buf, r); |
| 40 | } |
| 41 | if (r != 0) { |
| 42 | return nullptr; |
| 43 | } |
| 44 | return str; |
| 45 | } |
| 46 | |
| 47 | } |
| 48 | |
| 49 | namespace android { |
| 50 | namespace util { |
| 51 | |
| 52 | std::unique_ptr<ProcResult> ExecuteBinary(const std::vector<std::string>& argv) { |
| 53 | int stdout[2]; // stdout[0] read, stdout[1] write |
| 54 | if (pipe(stdout) != 0) { |
| 55 | PLOG(ERROR) << "pipe"; |
| 56 | return nullptr; |
| 57 | } |
| 58 | |
| 59 | int stderr[2]; // stdout[0] read, stdout[1] write |
| 60 | if (pipe(stderr) != 0) { |
| 61 | PLOG(ERROR) << "pipe"; |
| 62 | close(stdout[0]); |
| 63 | close(stdout[1]); |
| 64 | return nullptr; |
| 65 | } |
| 66 | |
Ryan Mitchell | a8f1366 | 2019-06-26 15:39:52 -0700 | [diff] [blame] | 67 | auto gid = getgid(); |
| 68 | auto uid = getuid(); |
| 69 | |
Mårten Kongstad | 2503a49 | 2018-09-27 13:32:30 +0200 | [diff] [blame] | 70 | char const** argv0 = (char const**)malloc(sizeof(char*) * (argv.size() + 1)); |
| 71 | for (size_t i = 0; i < argv.size(); i++) { |
| 72 | argv0[i] = argv[i].c_str(); |
| 73 | } |
| 74 | argv0[argv.size()] = nullptr; |
| 75 | switch (fork()) { |
| 76 | case -1: // error |
| 77 | free(argv0); |
| 78 | PLOG(ERROR) << "fork"; |
| 79 | return nullptr; |
| 80 | case 0: // child |
Ryan Mitchell | a8f1366 | 2019-06-26 15:39:52 -0700 | [diff] [blame] | 81 | if (setgid(gid) != 0) { |
| 82 | PLOG(ERROR) << "setgid"; |
| 83 | exit(1); |
| 84 | } |
| 85 | |
| 86 | if (setuid(uid) != 0) { |
| 87 | PLOG(ERROR) << "setuid"; |
| 88 | exit(1); |
| 89 | } |
| 90 | |
Mårten Kongstad | 2503a49 | 2018-09-27 13:32:30 +0200 | [diff] [blame] | 91 | close(stdout[0]); |
| 92 | if (dup2(stdout[1], STDOUT_FILENO) == -1) { |
| 93 | abort(); |
| 94 | } |
| 95 | close(stderr[0]); |
| 96 | if (dup2(stderr[1], STDERR_FILENO) == -1) { |
| 97 | abort(); |
| 98 | } |
| 99 | execvp(argv0[0], const_cast<char* const*>(argv0)); |
| 100 | PLOG(ERROR) << "execv"; |
| 101 | abort(); |
| 102 | default: // parent |
| 103 | free(argv0); |
| 104 | close(stdout[1]); |
| 105 | close(stderr[1]); |
| 106 | int status; |
| 107 | wait(&status); |
| 108 | if (!WIFEXITED(status)) { |
| 109 | return nullptr; |
| 110 | } |
| 111 | std::unique_ptr<ProcResult> result(new ProcResult()); |
| 112 | result->status = status; |
| 113 | const auto out = ReadFile(stdout[0]); |
| 114 | result->stdout = out ? *out : ""; |
| 115 | close(stdout[0]); |
| 116 | const auto err = ReadFile(stderr[0]); |
| 117 | result->stderr = err ? *err : ""; |
| 118 | close(stderr[0]); |
| 119 | return result; |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | } // namespace util |
| 124 | } // namespace android |
| 125 | #endif |