1 /* 2 * plausible.c --- Figure out if a pathname is ext* or something else. 3 * 4 * Copyright 2014, Oracle, Inc. 5 * 6 * Some parts are: 7 * Copyright 1995, 1996, 1997, 1998, 1999, 2000 by Theodore Ts'o. 8 * 9 * %Begin-Header% 10 * This file may be redistributed under the terms of the GNU Public 11 * License. 12 * %End-Header% 13 */ 14 15 #ifndef _LARGEFILE_SOURCE 16 #define _LARGEFILE_SOURCE 17 #endif 18 #ifndef _LARGEFILE64_SOURCE 19 #define _LARGEFILE64_SOURCE 20 #endif 21 22 #include "config.h" 23 #include <fcntl.h> 24 #include <time.h> 25 #include <sys/types.h> 26 #ifdef HAVE_SYS_STAT_H 27 #include <sys/stat.h> 28 #endif 29 #ifdef HAVE_UNISTD_H 30 #include <unistd.h> 31 #endif 32 #ifdef HAVE_MAGIC_H 33 #include <magic.h> 34 #endif 35 #include "plausible.h" 36 #include "ext2fs/ext2fs.h" 37 #include "nls-enable.h" 38 #include "blkid/blkid.h" 39 40 #ifdef HAVE_MAGIC_H 41 static magic_t (*dl_magic_open)(int); 42 static const char *(*dl_magic_file)(magic_t, const char *); 43 static int (*dl_magic_load)(magic_t, const char *); 44 static void (*dl_magic_close)(magic_t); 45 46 /* 47 * NO_CHECK functionality was only added in file 4.20. 48 * Older systems like RHEL 5.x still have file 4.17 49 */ 50 #ifndef MAGIC_NO_CHECK_COMPRESS 51 #define MAGIC_NO_CHECK_COMPRESS 0x0001000 52 #endif 53 #ifndef MAGIC_NO_CHECK_ELF 54 #define MAGIC_NO_CHECK_ELF 0x0010000 55 #endif 56 57 #ifdef HAVE_DLOPEN 58 #include <dlfcn.h> 59 60 static void *magic_handle; 61 62 static int magic_library_available(void) 63 { 64 if (!magic_handle) { 65 magic_handle = dlopen("libmagic.so.1", RTLD_NOW); 66 if (!magic_handle) 67 return 0; 68 69 dl_magic_open = (magic_t (*)(int)) 70 dlsym(magic_handle, "magic_open"); 71 dl_magic_file = (const char *(*)(magic_t, const char *)) 72 dlsym(magic_handle, "magic_file"); 73 dl_magic_load = (int (*)(magic_t, const char *)) 74 dlsym(magic_handle, "magic_load"); 75 dl_magic_close = (void (*)(magic_t)) 76 dlsym(magic_handle, "magic_close"); 77 } 78 79 if (!dl_magic_open || !dl_magic_file || 80 !dl_magic_load || !dl_magic_close) 81 return 0; 82 return 1; 83 } 84 #else 85 static int magic_library_available(void) 86 { 87 dl_magic_open = magic_open; 88 dl_magic_file = magic_file; 89 dl_magic_load = magic_load; 90 dl_magic_close = magic_close; 91 92 return 1; 93 } 94 #endif 95 #endif 96 97 static void print_ext2_info(const char *device) 98 99 { 100 struct ext2_super_block *sb; 101 ext2_filsys fs; 102 errcode_t retval; 103 time_t tm; 104 105 retval = ext2fs_open2(device, 0, EXT2_FLAG_64BITS, 0, 0, 106 unix_io_manager, &fs); 107 if (retval) 108 return; 109 sb = fs->super; 110 111 if (sb->s_mtime) { 112 tm = sb->s_mtime; 113 if (sb->s_last_mounted[0]) 114 printf(_("\tlast mounted on %.*s on %s"), 115 EXT2_LEN_STR(sb->s_last_mounted), ctime(&tm)); 116 else 117 printf(_("\tlast mounted on %s"), ctime(&tm)); 118 } else if (sb->s_mkfs_time) { 119 tm = sb->s_mkfs_time; 120 printf(_("\tcreated on %s"), ctime(&tm)); 121 } else if (sb->s_wtime) { 122 tm = sb->s_wtime; 123 printf(_("\tlast modified on %s"), ctime(&tm)); 124 } 125 ext2fs_close_free(&fs); 126 } 127 128 /* 129 * return 1 if there is no partition table, 0 if a partition table is 130 * detected, and -1 on an error. 131 */ 132 #ifdef HAVE_BLKID_PROBE_ENABLE_PARTITIONS 133 static int check_partition_table(const char *device) 134 { 135 blkid_probe pr; 136 const char *value; 137 int ret; 138 139 pr = blkid_new_probe_from_filename(device); 140 if (!pr) 141 return -1; 142 143 ret = blkid_probe_enable_partitions(pr, 1); 144 if (ret < 0) 145 goto errout; 146 147 ret = blkid_probe_enable_superblocks(pr, 0); 148 if (ret < 0) 149 goto errout; 150 151 ret = blkid_do_fullprobe(pr); 152 if (ret < 0) 153 goto errout; 154 155 ret = blkid_probe_lookup_value(pr, "PTTYPE", &value, NULL); 156 if (ret == 0) 157 fprintf(stderr, _("Found a %s partition table in %s\n"), 158 value, device); 159 else 160 ret = 1; 161 162 errout: 163 blkid_free_probe(pr); 164 return ret; 165 } 166 #else 167 static int check_partition_table(const char *device EXT2FS_ATTR((unused))) 168 { 169 return -1; 170 } 171 #endif 172 173 /* 174 * return 1 if the device looks plausible, creating the file if necessary 175 */ 176 int check_plausibility(const char *device, int flags, int *ret_is_dev) 177 { 178 int fd, ret, is_dev = 0; 179 ext2fs_struct_stat s; 180 int fl = O_RDONLY; 181 blkid_cache cache = NULL; 182 char *fs_type = NULL; 183 char *fs_label = NULL; 184 185 fd = ext2fs_open_file(device, fl, 0666); 186 if ((fd < 0) && (errno == ENOENT) && (flags & NO_SIZE)) { 187 fprintf(stderr, _("The file %s does not exist and no " 188 "size was specified.\n"), device); 189 exit(1); 190 } 191 if ((fd < 0) && (errno == ENOENT) && (flags & CREATE_FILE)) { 192 fl |= O_CREAT; 193 fd = ext2fs_open_file(device, fl, 0666); 194 if (fd >= 0 && (flags & VERBOSE_CREATE)) 195 printf(_("Creating regular file %s\n"), device); 196 } 197 if (fd < 0) { 198 fprintf(stderr, _("Could not open %s: %s\n"), 199 device, error_message(errno)); 200 if (errno == ENOENT) 201 fputs(_("\nThe device apparently does not exist; " 202 "did you specify it correctly?\n"), stderr); 203 exit(1); 204 } 205 206 if (ext2fs_fstat(fd, &s) < 0) { 207 perror("stat"); 208 exit(1); 209 } 210 close(fd); 211 212 if (S_ISBLK(s.st_mode)) 213 is_dev = 1; 214 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) 215 /* On FreeBSD, all disk devices are character specials */ 216 if (S_ISCHR(s.st_mode)) 217 is_dev = 1; 218 #endif 219 if (ret_is_dev) 220 *ret_is_dev = is_dev; 221 222 if ((flags & CHECK_BLOCK_DEV) && !is_dev) { 223 printf(_("%s is not a block special device.\n"), device); 224 return 0; 225 } 226 227 /* 228 * Note: we use the older-style blkid API's here because we 229 * want as much functionality to be available when using the 230 * internal blkid library, when e2fsprogs is compiled for 231 * non-Linux systems that will probably not have the libraries 232 * from util-linux available. We only use the newer 233 * blkid-probe interfaces to access functionality not 234 * available in the original blkid library. 235 */ 236 if ((flags & CHECK_FS_EXIST) && blkid_get_cache(&cache, NULL) >= 0) { 237 fs_type = blkid_get_tag_value(cache, "TYPE", device); 238 if (fs_type) 239 fs_label = blkid_get_tag_value(cache, "LABEL", device); 240 blkid_put_cache(cache); 241 } 242 243 if (fs_type) { 244 if (fs_label) 245 printf(_("%s contains a %s file system labelled '%s'\n"), 246 device, fs_type, fs_label); 247 else 248 printf(_("%s contains a %s file system\n"), device, 249 fs_type); 250 if (strncmp(fs_type, "ext", 3) == 0) 251 print_ext2_info(device); 252 free(fs_type); 253 free(fs_label); 254 return 0; 255 } 256 257 #ifdef HAVE_MAGIC_H 258 if ((flags & CHECK_FS_EXIST) && 259 !getenv("E2FSPROGS_LIBMAGIC_SUPPRESS") && 260 magic_library_available()) { 261 const char *msg; 262 magic_t mag; 263 int has_magic = 0; 264 265 mag = dl_magic_open(MAGIC_RAW | MAGIC_SYMLINK | MAGIC_DEVICES | 266 MAGIC_ERROR | MAGIC_NO_CHECK_ELF | 267 MAGIC_NO_CHECK_COMPRESS); 268 dl_magic_load(mag, NULL); 269 270 msg = dl_magic_file(mag, device); 271 if (msg && strcmp(msg, "data") && strcmp(msg, "empty")) { 272 printf(_("%s contains `%s' data\n"), device, msg); 273 has_magic = 1; 274 } 275 276 dl_magic_close(mag); 277 return !has_magic; 278 } 279 #endif 280 281 ret = check_partition_table(device); 282 if (ret >= 0) 283 return ret; 284 285 return 1; 286 } 287 