extras/volume_id/vol_id.c

   1 /*
   2  * vol_id - read filesystem label and uuid
   3  *
   4  * Copyright (C) 2005-2008 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #ifndef _GNU_SOURCE
  21 #define _GNU_SOURCE 1
  22 #endif
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <unistd.h>
  27 #include <string.h>
  28 #include <ctype.h>
  29 #include <errno.h>
  30 #include <pwd.h>
  31 #include <grp.h>
  32 #include <getopt.h>
  33 #include <fcntl.h>
  34 #include <inttypes.h>
  35 #include <sys/ioctl.h>
  36
  37 #include "../../udev/udev.h"
  38 #include "lib/libvolume_id.h"
  39
  40 #define BLKGETSIZE64 _IOR(0x12,114,size_t)
  41
  42 static int debug;
  43 struct udev *udev_ctx;
  44
  45 static void log_fn(struct udev *udev, int priority,
  46                    const char *file, int line, const char *fn,
  47                    const char *format, va_list args)
  48 {
  49         if (debug) {
  50                 fprintf(stderr, "%s: ", fn != NULL ? fn : file);
  51                 vfprintf(stderr, format, args);
  52         } else {
  53                 vsyslog(priority, format, args);
  54         }
  55 }
  56
  57 static void vid_log(int priority, const char *file, int line, const char *format, ...)
  58 {
  59         va_list args;
  60
  61         if (priority > udev_get_log_priority(udev_ctx))
  62                 return;
  63         va_start(args, format);
  64         log_fn(udev_ctx, priority, file, line, NULL, format, args);
  65         va_end(args);
  66         return;
  67 }
  68
  69 static void set_str(char *to, const char *from, size_t count)
  70 {
  71         size_t i, j, len;
  72
  73         /* strip trailing whitespace */
  74         len = strnlen(from, count);
  75         while (len && isspace(from[len-1]))
  76                 len--;
  77
  78         /* strip leading whitespace */
  79         i = 0;
  80         while (isspace(from[i]) && (i < len))
  81                 i++;
  82
  83         j = 0;
  84         while (i < len) {
  85                 /* substitute multiple whitespace */
  86                 if (isspace(from[i])) {
  87                         while (isspace(from[i]))
  88                                 i++;
  89                         to[j++] = '_';
  90                 }
  91                 /* skip chars */
  92                 if (from[i] == '/') {
  93                         i++;
  94                         continue;
  95                 }
  96                 to[j++] = from[i++];
  97         }
  98         to[j] = '\0';
  99 }
 100
 101 static int all_probers(volume_id_probe_fn_t probe_fn,
 102                        struct volume_id *id, uint64_t off, uint64_t size,
 103                        void *data)
 104 {
 105         const char *type;
 106
 107         if (probe_fn(id, off, size) == 0)
 108                 if (volume_id_get_type(id, &type))
 109                         printf("%s\n", type);
 110
 111         return 0;
 112 }
 113
 114 int main(int argc, char *argv[])
 115 {
 116         static const struct option options[] = {
 117                 { "label", no_argument, NULL, 'l' },
 118                 { "label-raw", no_argument, NULL, 'L' },
 119                 { "uuid", no_argument, NULL, 'u' },
 120                 { "type", no_argument, NULL, 't' },
 121                 { "export", no_argument, NULL, 'x' },
 122                 { "skip-raid", no_argument, NULL, 's' },
 123                 { "size", required_argument, NULL, 'S' },
 124                 { "probe-all", no_argument, NULL, 'a' },
 125                 { "offset", optional_argument, NULL, 'o' },
 126                 { "debug", no_argument, NULL, 'd' },
 127                 { "help", no_argument, NULL, 'h' },
 128                 {}
 129         };
 130
 131         enum print_type {
 132                 PRINT_EXPORT,
 133                 PRINT_TYPE,
 134                 PRINT_LABEL,
 135                 PRINT_UUID,
 136                 PRINT_LABEL_RAW,
 137         } print = PRINT_EXPORT;
 138
 139         struct volume_id *vid = NULL;
 140         char label_safe[256];
 141         char label_enc[256];
 142         char uuid_safe[256];
 143         char uuid_enc[256];
 144         char type_enc[256];
 145         char type_version_enc[256];
 146         uint64_t size = 0;
 147         int skip_raid = 0;
 148         int probe_all = 0;
 149         uint64_t offset = 0;
 150         const char *node;
 151         int fd;
 152         const char *label, *uuid, *type, *type_version, *usage;
 153         int retval;
 154         int rc = 0;
 155
 156         udev_ctx = udev_new();
 157         if (udev_ctx == NULL)
 158                 goto exit;
 159         logging_init("vol_id");
 160         udev_set_log_fn(udev_ctx, log_fn);
 161
 162         /* hook in our debug into libvolume_id */
 163         volume_id_log_fn = vid_log;
 164
 165         while (1) {
 166                 int option;
 167
 168                 option = getopt_long(argc, argv, "lLutxsS:aodh", options, NULL);
 169                 if (option == -1)
 170                         break;
 171
 172                 switch (option) {
 173                 case 'd':
 174                         debug = 1;
 175                         if (udev_get_log_priority(udev_ctx) < LOG_INFO)
 176                                 udev_set_log_priority(udev_ctx, LOG_INFO);
 177                         break;
 178                 case 'l':
 179                         print = PRINT_LABEL;
 180                         break;
 181                 case 'L':
 182                         print = PRINT_LABEL_RAW;
 183                         break;
 184                 case 'u':
 185                         print = PRINT_UUID;
 186                         break;
 187                 case 't':
 188                         print = PRINT_TYPE;
 189                         break;
 190                 case 'x':
 191                         print = PRINT_EXPORT;
 192                         break;
 193                 case 's':
 194                         skip_raid = 1;
 195                         break;
 196                 case 'a':
 197                         probe_all = 1;
 198                         break;
 199                 case 'S':
 200                         if (optarg[0] != '\0')
 201                                 size = strtoull(optarg, NULL, 0);
 202                         break;
 203                 case 'o':
 204                         if (optarg[0] != '\0')
 205                                 offset = strtoull(optarg, NULL, 0);
 206                         break;
 207                 case 'h':
 208                         printf("Usage: vol_id [options] <device>\n"
 209                             " --export         export key/value pairs\n"
 210                             " --type           filesystem type\n"
 211                             " --label          filesystem label\n"
 212                             " --label-raw      raw label\n"
 213                             " --uuid           filesystem uuid\n"
 214                             " --skip-raid      don't probe for raid\n"
 215                             " --probe-all      find possibly conflicting signatures\n"
 216                             " --offset=<bytes> probe at the given offset\n"
 217                             " --size=<bytes>   overwrite device size\n"
 218                             " --debug          print debug output to stderr\n"
 219                             " --help\n\n");
 220                         goto exit;
 221                 default:
 222                         retval = 1;
 223                         goto exit;
 224                 }
 225         }
 226
 227         node = argv[optind];
 228         if (!node) {
 229                 err(udev_ctx, "no device\n");
 230                 fprintf(stderr, "no device\n");
 231                 rc = 1;
 232                 goto exit;
 233         }
 234
 235         fd = open(node, O_RDONLY);
 236         if (fd < 0) {
 237                 fprintf(stderr, "%s: error opening volume\n", node);
 238                 rc = 2;
 239                 goto exit;
 240         }
 241
 242         vid = volume_id_open_fd(fd);
 243         if (vid == NULL) {
 244                 rc = 2;
 245                 goto exit;
 246         }
 247
 248         if (size == 0) {
 249                 if (ioctl(fd, BLKGETSIZE64, &size) != 0)
 250                         size = 0;
 251                 info(udev_ctx, "BLKGETSIZE64=%" PRIu64 " (%" PRIu64 "GB)\n", size, size >> 30);
 252         }
 253
 254         /* try to drop all privileges before reading disk content */
 255         if (getuid() == 0) {
 256                 struct passwd *pw;
 257
 258                 pw = getpwnam("nobody");
 259                 if (pw != NULL && pw->pw_uid > 0 && pw->pw_gid > 0) {
 260                         if (setgroups(0, NULL) != 0 ||
 261                             setgid(pw->pw_gid) != 0 ||
 262                             setuid(pw->pw_uid) != 0)
 263                                 info(udev_ctx, "unable to drop privileges: %s\n\n", strerror(errno));
 264                 }
 265         }
 266
 267         if (probe_all) {
 268                 volume_id_all_probers(all_probers, vid, offset, size, NULL);
 269                 goto exit;
 270         }
 271
 272         if (skip_raid)
 273                 retval = volume_id_probe_filesystem(vid, offset, size);
 274         else
 275                 retval = volume_id_probe_all(vid, offset, size);
 276         if (retval != 0) {
 277                 fprintf(stderr, "%s: unknown volume type\n", node);
 278                 rc = 4;
 279                 goto exit;
 280         }
 281
 282         if (!volume_id_get_label(vid, &label) ||
 283             !volume_id_get_usage(vid, &usage) ||
 284             !volume_id_get_type(vid, &type) ||
 285             !volume_id_get_type_version(vid, &type_version) ||
 286             !volume_id_get_uuid(vid, &uuid)) {
 287                 rc = 4;
 288                 goto exit;
 289         }
 290
 291         set_str(label_safe, label, sizeof(label_safe));
 292         util_replace_chars(label_safe, ALLOWED_CHARS_INPUT);
 293         volume_id_encode_string(label, label_enc, sizeof(label_enc));
 294
 295         set_str(uuid_safe, uuid, sizeof(uuid_safe));
 296         util_replace_chars(uuid_safe, ALLOWED_CHARS_INPUT);
 297         volume_id_encode_string(uuid, uuid_enc, sizeof(uuid_enc));
 298
 299         volume_id_encode_string(type, type_enc, sizeof(type_enc));
 300         volume_id_encode_string(type_version, type_version_enc, sizeof(type_version_enc));
 301
 302         switch (print) {
 303         case PRINT_EXPORT:
 304                 printf("ID_FS_USAGE=%s\n", usage);
 305                 printf("ID_FS_TYPE=%s\n", type_enc);
 306                 printf("ID_FS_VERSION=%s\n", type_version_enc);
 307                 printf("ID_FS_UUID=%s\n", uuid_safe);
 308                 printf("ID_FS_UUID_ENC=%s\n", uuid_enc);
 309                 printf("ID_FS_LABEL=%s\n", label_safe);
 310                 printf("ID_FS_LABEL_ENC=%s\n", label_enc);
 311                 break;
 312         case PRINT_TYPE:
 313                 printf("%s\n", type);
 314                 break;
 315         case PRINT_LABEL:
 316                 if (label_safe[0] == '\0' || strcmp(usage, "raid") == 0) {
 317                         rc = 3;
 318                         goto exit;
 319                 }
 320                 printf("%s\n", label_safe);
 321                 break;
 322         case PRINT_UUID:
 323                 if (uuid_enc[0] == '\0' || strcmp(usage, "raid") == 0) {
 324                         rc = 4;
 325                         goto exit;
 326                 }
 327                 printf("%s\n", uuid_enc);
 328                 break;
 329         case PRINT_LABEL_RAW:
 330                 if (label[0] == '\0' || strcmp(usage, "raid") == 0) {
 331                         rc = 3;
 332                         goto exit;
 333                 }
 334                 printf("%s\n", label);
 335                 break;
 336         }
 337
 338 exit:
 339         if (vid != NULL)
 340                 volume_id_close(vid);
 341         udev_unref(udev_ctx);
 342         logging_close();
 343         return rc;
 344 }