1 /* Copyright (c) 2010 The Chromium OS Authors. All rights reserved. 2 * Use of this source code is governed by a BSD-style license that can be 3 * found in the LICENSE file. 4 * 5 * Driver for using rootdev.c from the commandline 6 */ 7 #include <err.h> 8 #include <errno.h> 9 #include <getopt.h> 10 #include <linux/limits.h> 11 #include <stdbool.h> 12 #include <stdio.h> 13 #include <stdlib.h> 14 #include <string.h> 15 #include <sys/stat.h> 16 #include <sys/types.h> 17 #include <unistd.h> 18 19 #include "rootdev.h" 20 print_help(const char * progname)21 static void print_help(const char *progname) { 22 fprintf(stderr, 23 "%s [OPTIONS] [PATH]\n" 24 "Outputs the containing device for the specified PATH.\n" 25 "With no arguments, '/' is assumed.\n" 26 "\n" 27 "Options:\n" 28 " -h\tthis message.\n" 29 "\n" 30 " -c\tcreate the /dev node if it cannot be found\n" 31 " -d\treturn the block device only if possible\n" 32 " -i\treturn path even if the node doesn't exist\n" 33 " -s\tif possible, return the first slave of the root device\n" 34 "\n" 35 " --block [path]\tset the path to block under the sys mount point\n" 36 " --dev [path]\tset the path to dev mount point\n" 37 " --major [num]\tset the major number of the rootdev\n" 38 " --minor [num]\tset the minor number of the rootdev\n", 39 progname); 40 } 41 42 static int flag_help = 0; 43 static int flag_use_slave = 0; 44 static int flag_strip_partition = 0; 45 static int flag_ignore = 0; 46 static int flag_create = 0; 47 static int flag_major = 0; 48 static int flag_minor = 0; 49 static const char *flag_path = "/"; 50 static char *flag_block_path = NULL; 51 static char *flag_dev_path = NULL; 52 parse_args(int argc,char ** argv)53 static void parse_args(int argc, char **argv) { 54 while (1) { 55 int c; 56 int option_index = 0; 57 static const struct option long_options[] = { 58 {"c", no_argument, &flag_create, 1}, 59 {"d", no_argument, &flag_strip_partition, 1}, 60 {"h", no_argument, &flag_help, 1}, 61 {"i", no_argument, &flag_ignore, 1}, 62 {"s", no_argument, &flag_use_slave, 1}, 63 /* Long arguments for testing. */ 64 {"block", required_argument, NULL, 'b'}, 65 {"dev", required_argument, NULL, 'd'}, 66 {"major", required_argument, NULL, 'M'}, 67 {"minor", required_argument, NULL, 'm'}, 68 {0, 0, 0, 0} 69 }; 70 c = getopt_long_only(argc, argv, "", long_options, &option_index); 71 72 if (c == -1) 73 break; 74 75 if (c == '?') { 76 flag_help = 1; 77 break; 78 } 79 80 switch (c) { 81 case 'b': 82 flag_block_path = optarg; 83 break; 84 case 'd': 85 flag_dev_path = optarg; 86 break; 87 case 'M': 88 flag_major = atoi(optarg); 89 break; 90 case 'm': 91 flag_minor = atoi(optarg); 92 break; 93 } 94 95 } 96 97 if (flag_create && flag_strip_partition) { 98 flag_help = 1; 99 warnx("-c and -d are incompatible at present."); 100 return; 101 } 102 103 if (optind < argc) { 104 flag_path = argv[optind++]; 105 } 106 107 if (optind < argc) { 108 fprintf(stderr, "Too many free arguments: %d\n", argc - optind); 109 flag_help = 1; 110 } 111 } 112 main(int argc,char ** argv)113 int main(int argc, char **argv) { 114 struct stat path_stat; 115 char path[PATH_MAX]; 116 int ret; 117 dev_t root_dev; 118 parse_args(argc, argv); 119 120 if (flag_help) { 121 print_help(argv[0]); 122 return 1; 123 } 124 125 if (flag_major || flag_minor) { 126 root_dev = makedev(flag_major, flag_minor); 127 } else { 128 /* Yields the containing dev_t in st_dev. */ 129 if (stat(flag_path, &path_stat) != 0) 130 err(1, "Cannot stat(%s)", flag_path); 131 root_dev = path_stat.st_dev; 132 } 133 134 path[0] = '\0'; 135 ret = rootdev_wrapper(path, sizeof(path), 136 flag_use_slave, 137 flag_strip_partition, 138 &root_dev, 139 flag_block_path, 140 flag_dev_path); 141 142 if (ret == 1 && flag_create) { 143 /* TODO(wad) add flag_force to allow replacement */ 144 ret = 0; 145 if (mknod(path, S_IFBLK | S_IRUSR | S_IWUSR, root_dev) && errno != EEXIST) { 146 warn("failed to create %s", path); 147 ret = 1; 148 } 149 } 150 151 if (flag_ignore && ret > 0) 152 ret = 0; 153 154 if (path[0] != '\0') 155 printf("%s\n", path); 156 157 return ret; 158 } 159