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