| /* |
| * Copyright (C) 2018 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifdef _WIN32 |
| // nothing to see here |
| #else |
| #include <memory> |
| #include <string> |
| #include <vector> |
| |
| #include <sys/types.h> |
| #include <sys/wait.h> |
| #include <unistd.h> |
| |
| #include "android-base/logging.h" |
| |
| #include "androidfw/PosixUtils.h" |
| |
| namespace { |
| |
| std::unique_ptr<std::string> ReadFile(int fd) { |
| std::unique_ptr<std::string> str(new std::string()); |
| char buf[1024]; |
| ssize_t r; |
| while ((r = read(fd, buf, sizeof(buf))) > 0) { |
| str->append(buf, r); |
| } |
| if (r != 0) { |
| return nullptr; |
| } |
| return str; |
| } |
| |
| } |
| |
| namespace android { |
| namespace util { |
| |
| std::unique_ptr<ProcResult> ExecuteBinary(const std::vector<std::string>& argv) { |
| int stdout[2]; // stdout[0] read, stdout[1] write |
| if (pipe(stdout) != 0) { |
| PLOG(ERROR) << "pipe"; |
| return nullptr; |
| } |
| |
| int stderr[2]; // stdout[0] read, stdout[1] write |
| if (pipe(stderr) != 0) { |
| PLOG(ERROR) << "pipe"; |
| close(stdout[0]); |
| close(stdout[1]); |
| return nullptr; |
| } |
| |
| auto gid = getgid(); |
| auto uid = getuid(); |
| |
| char const** argv0 = (char const**)malloc(sizeof(char*) * (argv.size() + 1)); |
| for (size_t i = 0; i < argv.size(); i++) { |
| argv0[i] = argv[i].c_str(); |
| } |
| argv0[argv.size()] = nullptr; |
| int pid = fork(); |
| switch (pid) { |
| case -1: // error |
| free(argv0); |
| PLOG(ERROR) << "fork"; |
| return nullptr; |
| case 0: // child |
| if (setgid(gid) != 0) { |
| PLOG(ERROR) << "setgid"; |
| exit(1); |
| } |
| |
| if (setuid(uid) != 0) { |
| PLOG(ERROR) << "setuid"; |
| exit(1); |
| } |
| |
| close(stdout[0]); |
| if (dup2(stdout[1], STDOUT_FILENO) == -1) { |
| abort(); |
| } |
| close(stderr[0]); |
| if (dup2(stderr[1], STDERR_FILENO) == -1) { |
| abort(); |
| } |
| execvp(argv0[0], const_cast<char* const*>(argv0)); |
| PLOG(ERROR) << "execv"; |
| abort(); |
| default: // parent |
| free(argv0); |
| close(stdout[1]); |
| close(stderr[1]); |
| int status; |
| waitpid(pid, &status, 0); |
| if (!WIFEXITED(status)) { |
| close(stdout[0]); |
| close(stderr[0]); |
| return nullptr; |
| } |
| std::unique_ptr<ProcResult> result(new ProcResult()); |
| result->status = status; |
| const auto out = ReadFile(stdout[0]); |
| result->stdout = out ? *out : ""; |
| close(stdout[0]); |
| const auto err = ReadFile(stderr[0]); |
| result->stderr = err ? *err : ""; |
| close(stderr[0]); |
| return result; |
| } |
| } |
| |
| } // namespace util |
| } // namespace android |
| #endif |