su.c revision e16cb84e2324f05334d18dcf5956f20f44262b62
1e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project/* 2e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project** 3e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project** Copyright 2008, The Android Open Source Project 4e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project** 5e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project** Licensed under the Apache License, Version 2.0 (the "License"); 6e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project** you may not use this file except in compliance with the License. 7e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project** You may obtain a copy of the License at 8e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project** 9e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project** http://www.apache.org/licenses/LICENSE-2.0 10e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project** 11e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project** Unless required by applicable law or agreed to in writing, software 12e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project** distributed under the License is distributed on an "AS IS" BASIS, 13e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project** See the License for the specific language governing permissions and 15e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project** limitations under the License. 16e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project*/ 17e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project 18e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project#include <stdio.h> 19e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project#include <stdlib.h> 20e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project#include <string.h> 21e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project#include <sys/types.h> 22e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project#include <dirent.h> 23e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project#include <errno.h> 24e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project 25e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project#include <unistd.h> 26e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project#include <time.h> 27e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project 28e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project#include <pwd.h> 29e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project 30e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project/* 31e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project * SU can be given a specific command to exec. UID _must_ be 32e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project * specified for this (ie argc => 3). 33e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project * 34e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project * Usage: 35e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project * su 1000 36e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project * su 1000 ls -l 37e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project */ 38e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Projectint main(int argc, char **argv) 39e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project{ 40e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project struct passwd *pw; 41e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project int uid, gid; 42e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project 43e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project if(argc < 2) { 44e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project uid = gid = 0; 45e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project } else { 46e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project pw = getpwnam(argv[1]); 47e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project 48e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project if(pw == 0) { 49e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project uid = gid = atoi(argv[1]); 50e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project } else { 51e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project uid = pw->pw_uid; 52e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project gid = pw->pw_gid; 53e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project } 54e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project } 55e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project 56e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project if(setgid(gid) || setuid(uid)) { 57e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project fprintf(stderr,"su: permission denied\n"); 58e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project return 1; 59e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project } 60e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project 61e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project /* User specified command for exec. */ 62e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project if (argc == 3 ) { 63e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project if (execlp(argv[2], argv[2], NULL) < 0) { 64e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project fprintf(stderr, "su: exec failed for %s Error:%s\n", argv[2], 65e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project strerror(errno)); 66e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project return -errno; 67e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project } 68e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project } else if (argc > 3) { 69e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project /* Copy the rest of the args from main. */ 70e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project char *exec_args[argc - 1]; 71e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project memset(exec_args, 0, sizeof(exec_args)); 72e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project memcpy(exec_args, &argv[2], sizeof(exec_args)); 73e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project if (execvp(argv[2], exec_args) < 0) { 74e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project fprintf(stderr, "su: exec failed for %s Error:%s\n", argv[2], 75e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project strerror(errno)); 76e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project return -errno; 77e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project } 78e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project } 79e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project 80e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project /* Default exec shell. */ 81e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project execlp("/system/bin/sh", "sh", NULL); 82e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project 83e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project fprintf(stderr, "su: exec failed\n"); 84e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project return 1; 85e16cb84e2324f05334d18dcf5956f20f44262b62The Android Open Source Project} 86