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 it
   7  *      under the terms of the GNU General Public License as published by the
   8  *      Free Software Foundation version 2 of the License.
   9  *
  10  *      This program is distributed in the hope that it will be useful, but
  11  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  *      General Public License for more details.
  14  *
  15  *      You should have received a copy of the GNU General Public License along
  16  *      with this program; if not, write to the Free Software Foundation, Inc.,
  17  *      675 Mass Ave, Cambridge, MA 02139, USA.
  18  *
  19  */
  20
  21 #ifndef _GNU_SOURCE
  22 #define _GNU_SOURCE 1
  23 #endif
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <unistd.h>
  28 #include <string.h>
  29 #include <ctype.h>
  30 #include <errno.h>
  31 #include <pwd.h>
  32 #include <grp.h>
  33 #include <getopt.h>
  34 #include <fcntl.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
  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         va_start(args, format);
  61         log_fn(NULL, priority, file, line, NULL, format, args);
  62         va_end(args);
  63         return;
  64 }
  65
  66 static void set_str(char *to, const char *from, size_t count)
  67 {
  68         size_t i, j, len;
  69
  70         /* strip trailing whitespace */
  71         len = strnlen(from, count);
  72         while (len && isspace(from[len-1]))
  73                 len--;
  74
  75         /* strip leading whitespace */
  76         i = 0;
  77         while (isspace(from[i]) && (i < len))
  78                 i++;
  79
  80         j = 0;
  81         while (i < len) {
  82                 /* substitute multiple whitespace */
  83                 if (isspace(from[i])) {
  84                         while (isspace(from[i]))
  85                                 i++;
  86                         to[j++] = '_';
  87                 }
  88                 /* skip chars */
  89                 if (from[i] == '/') {
  90                         i++;
  91                         continue;
  92                 }
  93                 to[j++] = from[i++];
  94         }
  95         to[j] = '\0';
  96 }
  97
  98 static int all_probers(volume_id_probe_fn_t probe_fn,
  99                        struct volume_id *id, uint64_t off, uint64_t size,
 100                        void *data)
 101 {
 102         const char *type;
 103
 104         if (probe_fn(id, off, size) == 0)
 105                 if (volume_id_get_type(id, &type))
 106                         printf("%s\n", type);
 107
 108         return 0;
 109 }
 110
 111 int main(int argc, char *argv[])
 112 {
 113         struct udev *udev;
 114         static const struct option options[] = {
 115                 { "label", 0, NULL, 'l' },
 116                 { "label-raw", 0, NULL, 'L' },
 117                 { "uuid", 0, NULL, 'u' },
 118                 { "type", 0, NULL, 't' },
 119                 { "export", 0, NULL, 'x' },
 120                 { "skip-raid", 0, NULL, 's' },
 121                 { "probe-all", 0, NULL, 'a' },
 122                 { "offset", 2, NULL, 'o' },
 123                 { "debug", 0, NULL, 'd' },
 124                 { "help", 0, NULL, 'h' },
 125                 {}
 126         };
 127
 128         enum print_type {
 129                 PRINT_EXPORT,
 130                 PRINT_TYPE,
 131                 PRINT_LABEL,
 132                 PRINT_UUID,
 133                 PRINT_LABEL_RAW,
 134         } print = PRINT_EXPORT;
 135
 136         struct volume_id *vid = NULL;
 137         char label_safe[256];
 138         char label_enc[256];
 139         char uuid_enc[256];
 140         uint64_t size;
 141         int skip_raid = 0;
 142         int probe_all = 0;
 143         uint64_t offset = 0;
 144         const char *node;
 145         int fd;
 146         const char *label, *uuid, *type, *type_version, *usage;
 147         int retval;
 148         int rc = 0;
 149
 150         udev = udev_new();
 151         if (udev == NULL)
 152                 goto exit;
 153         logging_init("vol_id");
 154         udev_set_log_fn(udev, log_fn);
 155
 156         /* hook in our debug into libvolume_id */
 157         volume_id_log_fn = vid_log;
 158
 159         while (1) {
 160                 int option;
 161
 162                 option = getopt_long(argc, argv, "lLutxsaodh", options, NULL);
 163                 if (option == -1)
 164                         break;
 165
 166                 switch (option) {
 167                 case 'd':
 168                         debug = 1;
 169                         if (udev_get_log_priority(udev) < LOG_INFO)
 170                                 udev_set_log_priority(udev, LOG_INFO);
 171                         break;
 172                 case 'l':
 173                         print = PRINT_LABEL;
 174                         break;
 175                 case 'L':
 176                         print = PRINT_LABEL_RAW;
 177                         break;
 178                 case 'u':
 179                         print = PRINT_UUID;
 180                         break;
 181                 case 't':
 182                         print = PRINT_TYPE;
 183                         break;
 184                 case 'x':
 185                         print = PRINT_EXPORT;
 186                         break;
 187                 case 's':
 188                         skip_raid = 1;
 189                         break;
 190                 case 'a':
 191                         probe_all = 1;
 192                         break;
 193                 case 'o':
 194                         if (optarg[0] != '\0')
 195                                 offset = strtoull(optarg, NULL, 0);
 196                         break;
 197                 case 'h':
 198                         printf("Usage: vol_id [options] <device>\n"
 199                             " --export         export key/value pairs\n"
 200                             " --type           filesystem type\n"
 201                             " --label          filesystem label\n"
 202                             " --label-raw      raw label\n"
 203                             " --uuid           filesystem uuid\n"
 204                             " --skip-raid      don't probe for raid\n"
 205                             " --probe-all      find possibly conflicting signatures\n"
 206                             " --offset=<bytes> probe at the given offset\n"
 207                             " --debug          print debug output to stderr\n"
 208                             " --help\n\n");
 209                         goto exit;
 210                 default:
 211                         retval = 1;
 212                         goto exit;
 213                 }
 214         }
 215
 216         node = argv[optind];
 217         if (!node) {
 218                 err(udev, "no device\n");
 219                 fprintf(stderr, "no device\n");
 220                 rc = 1;
 221                 goto exit;
 222         }
 223
 224         fd = open(node, O_RDONLY);
 225         if (fd < 0) {
 226                 fprintf(stderr, "%s: error opening volume\n", node);
 227                 rc = 2;
 228                 goto exit;
 229         }
 230
 231         vid = volume_id_open_fd(fd);
 232         if (vid == NULL) {
 233                 rc = 2;
 234                 goto exit;
 235         }
 236
 237         if (ioctl(fd, BLKGETSIZE64, &size) != 0)
 238                 size = 0;
 239         info(udev, "BLKGETSIZE64=%llu (%lluGB)\n", (unsigned long long)size, (unsigned long long)size >> 30);
 240
 241         /* try to drop all privileges before reading disk content */
 242         if (getuid() == 0) {
 243                 struct passwd *pw;
 244
 245                 pw = getpwnam("nobody");
 246                 if (pw != NULL && pw->pw_uid > 0 && pw->pw_gid > 0) {
 247                         if (setgroups(0, NULL) != 0 ||
 248                             setgid(pw->pw_gid) != 0 ||
 249                             setuid(pw->pw_uid) != 0)
 250                                 info(udev, "unable to drop privileges: %s\n\n", strerror(errno));
 251                 }
 252         }
 253
 254         if (probe_all) {
 255                 volume_id_all_probers(all_probers, vid, offset, size, NULL);
 256                 goto exit;
 257         }
 258
 259         if (skip_raid)
 260                 retval = volume_id_probe_filesystem(vid, offset, size);
 261         else
 262                 retval = volume_id_probe_all(vid, offset, size);
 263         if (retval != 0) {
 264                 fprintf(stderr, "%s: unknown volume type\n", node);
 265                 rc = 4;
 266                 goto exit;
 267         }
 268
 269         if (!volume_id_get_label(vid, &label) ||
 270             !volume_id_get_usage(vid, &usage) ||
 271             !volume_id_get_type(vid, &type) ||
 272             !volume_id_get_type_version(vid, &type_version) ||
 273             !volume_id_get_uuid(vid, &uuid)) {
 274                 rc = 4;
 275                 goto exit;
 276         }
 277
 278         set_str(label_safe, label, sizeof(label_safe));
 279         replace_chars(label_safe, ALLOWED_CHARS_INPUT);
 280
 281         volume_id_encode_string(label, label_enc, sizeof(label_enc));
 282         volume_id_encode_string(uuid, uuid_enc, sizeof(uuid_enc));
 283
 284         switch (print) {
 285         case PRINT_EXPORT:
 286                 printf("ID_FS_USAGE=%s\n", usage);
 287                 printf("ID_FS_TYPE=%s\n", type);
 288                 printf("ID_FS_VERSION=%s\n", type_version);
 289                 printf("ID_FS_UUID=%s\n", uuid);
 290                 printf("ID_FS_UUID_ENC=%s\n", uuid_enc);
 291                 printf("ID_FS_LABEL=%s\n", label);
 292                 printf("ID_FS_LABEL_ENC=%s\n", label_enc);
 293                 printf("ID_FS_LABEL_SAFE=%s\n", label_safe);
 294                 break;
 295         case PRINT_TYPE:
 296                 printf("%s\n", type);
 297                 break;
 298         case PRINT_LABEL:
 299                 if (label_safe[0] == '\0' || strcmp(usage, "raid") == 0) {
 300                         rc = 3;
 301                         goto exit;
 302                 }
 303                 printf("%s\n", label_safe);
 304                 break;
 305         case PRINT_UUID:
 306                 if (uuid_enc[0] == '\0' || strcmp(usage, "raid") == 0) {
 307                         rc = 4;
 308                         goto exit;
 309                 }
 310                 printf("%s\n", uuid_enc);
 311                 break;
 312         case PRINT_LABEL_RAW:
 313                 if (label[0] == '\0' || strcmp(usage, "raid") == 0) {
 314                         rc = 3;
 315                         goto exit;
 316                 }
 317                 printf("%s\n", label);
 318                 break;
 319         }
 320
 321 exit:
 322         if (vid != NULL)
 323                 volume_id_close(vid);
 324         udev_unref(udev);
 325         logging_close();
 326         return rc;
 327 }