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