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 char buf[80]; 105 106 retval = ext2fs_open2(device, 0, EXT2_FLAG_64BITS, 0, 0, 107 unix_io_manager, &fs); 108 if (retval) 109 return; 110 sb = fs->super; 111 112 if (sb->s_mtime) { 113 tm = sb->s_mtime; 114 if (sb->s_last_mounted[0]) { 115 memset(buf, 0, sizeof(buf)); 116 strncpy(buf, sb->s_last_mounted, 117 sizeof(sb->s_last_mounted)); 118 printf(_("\tlast mounted on %s on %s"), buf, 119 ctime(&tm)); 120 } else 121 printf(_("\tlast mounted on %s"), ctime(&tm)); 122 } else if (sb->s_mkfs_time) { 123 tm = sb->s_mkfs_time; 124 printf(_("\tcreated on %s"), ctime(&tm)); 125 } else if (sb->s_wtime) { 126 tm = sb->s_wtime; 127 printf(_("\tlast modified on %s"), ctime(&tm)); 128 } 129 ext2fs_close_free(&fs); 130 } 131 132 /* 133 * return 1 if there is no partition table, 0 if a partition table is 134 * detected, and -1 on an error. 135 */ 136 #ifdef HAVE_BLKID_PROBE_ENABLE_PARTITIONS 137 static int check_partition_table(const char *device) 138 { 139 blkid_probe pr; 140 const char *value; 141 int ret; 142 143 pr = blkid_new_probe_from_filename(device); 144 if (!pr) 145 return -1; 146 147 ret = blkid_probe_enable_partitions(pr, 1); 148 if (ret < 0) 149 goto errout; 150 151 ret = blkid_probe_enable_superblocks(pr, 0); 152 if (ret < 0) 153 goto errout; 154 155 ret = blkid_do_fullprobe(pr); 156 if (ret < 0) 157 goto errout; 158 159 ret = blkid_probe_lookup_value(pr, "PTTYPE", &value, NULL); 160 if (ret == 0) 161 fprintf(stderr, _("Found a %s partition table in %s\n"), 162 value, device); 163 else 164 ret = 1; 165 166 errout: 167 blkid_free_probe(pr); 168 return ret; 169 } 170 #else 171 static int check_partition_table(const char *device EXT2FS_ATTR((unused))) 172 { 173 return -1; 174 } 175 #endif 176 177 /* 178 * return 1 if the device looks plausible, creating the file if necessary 179 */ 180 int check_plausibility(const char *device, int flags, int *ret_is_dev) 181 { 182 int fd, ret, is_dev = 0; 183 ext2fs_struct_stat s; 184 int fl = O_RDONLY; 185 blkid_cache cache = NULL; 186 char *fs_type = NULL; 187 char *fs_label = NULL; 188 189 fd = ext2fs_open_file(device, fl, 0666); 190 if ((fd < 0) && (errno == ENOENT) && (flags & NO_SIZE)) { 191 fprintf(stderr, _("The file %s does not exist and no " 192 "size was specified.\n"), device); 193 exit(1); 194 } 195 if ((fd < 0) && (errno == ENOENT) && (flags & CREATE_FILE)) { 196 fl |= O_CREAT; 197 fd = ext2fs_open_file(device, fl, 0666); 198 if (fd >= 0 && (flags & VERBOSE_CREATE)) 199 printf(_("Creating regular file %s\n"), device); 200 } 201 if (fd < 0) { 202 fprintf(stderr, _("Could not open %s: %s\n"), 203 device, error_message(errno)); 204 if (errno == ENOENT) 205 fputs(_("\nThe device apparently does not exist; " 206 "did you specify it correctly?\n"), stderr); 207 exit(1); 208 } 209 210 if (ext2fs_fstat(fd, &s) < 0) { 211 perror("stat"); 212 exit(1); 213 } 214 close(fd); 215 216 if (S_ISBLK(s.st_mode)) 217 is_dev = 1; 218 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) 219 /* On FreeBSD, all disk devices are character specials */ 220 if (S_ISCHR(s.st_mode)) 221 is_dev = 1; 222 #endif 223 if (ret_is_dev) 224 *ret_is_dev = is_dev; 225 226 if ((flags & CHECK_BLOCK_DEV) && !is_dev) { 227 printf(_("%s is not a block special device.\n"), device); 228 return 0; 229 } 230 231 /* 232 * Note: we use the older-style blkid API's here because we 233 * want as much functionality to be available when using the 234 * internal blkid library, when e2fsprogs is compiled for 235 * non-Linux systems that will probably not have the libraries 236 * from util-linux available. We only use the newer 237 * blkid-probe interfaces to access functionality not 238 * available in the original blkid library. 239 */ 240 if ((flags & CHECK_FS_EXIST) && blkid_get_cache(&cache, NULL) >= 0) { 241 fs_type = blkid_get_tag_value(cache, "TYPE", device); 242 if (fs_type) 243 fs_label = blkid_get_tag_value(cache, "LABEL", device); 244 blkid_put_cache(cache); 245 } 246 247 if (fs_type) { 248 if (fs_label) 249 printf(_("%s contains a %s file system labelled '%s'\n"), 250 device, fs_type, fs_label); 251 else 252 printf(_("%s contains a %s file system\n"), device, 253 fs_type); 254 if (strncmp(fs_type, "ext", 3) == 0) 255 print_ext2_info(device); 256 free(fs_type); 257 free(fs_label); 258 return 0; 259 } 260 261 #ifdef HAVE_MAGIC_H 262 if ((flags & CHECK_FS_EXIST) && 263 !getenv("E2FSPROGS_LIBMAGIC_SUPPRESS") && 264 magic_library_available()) { 265 const char *msg; 266 magic_t mag; 267 int has_magic = 0; 268 269 mag = dl_magic_open(MAGIC_RAW | MAGIC_SYMLINK | MAGIC_DEVICES | 270 MAGIC_ERROR | MAGIC_NO_CHECK_ELF | 271 MAGIC_NO_CHECK_COMPRESS); 272 dl_magic_load(mag, NULL); 273 274 msg = dl_magic_file(mag, device); 275 if (msg && strcmp(msg, "data") && strcmp(msg, "empty")) { 276 printf(_("%s contains `%s' data\n"), device, msg); 277 has_magic = 1; 278 } 279 280 dl_magic_close(mag); 281 return !has_magic; 282 } 283 #endif 284 285 ret = check_partition_table(device); 286 if (ret >= 0) 287 return ret; 288 289 return 1; 290 } 291