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/stat.h>
  35 #include <inttypes.h>
  36 #include <sys/ioctl.h>
  37
  38 #include "../../udev/udev.h"
  39 #include "lib/libvolume_id.h"
  40
  41 #define BLKGETSIZE64 _IOR(0x12,114,size_t)
  42
  43 static int debug;
  44 struct udev *udev_ctx;
  45
  46 static void log_fn(struct udev *udev, int priority,
  47                    const char *file, int line, const char *fn,
  48                    const char *format, va_list args)
  49 {
  50         if (debug) {
  51                 fprintf(stderr, "%s: ", fn != NULL ? fn : file);
  52                 vfprintf(stderr, format, args);
  53         } else {
  54                 vsyslog(priority, format, args);
  55         }
  56 }
  57
  58 static void vid_log(int priority, const char *file, int line, const char *format, ...)
  59 {
  60         va_list args;
  61
  62         if (priority > udev_get_log_priority(udev_ctx))
  63                 return;
  64         va_start(args, format);
  65         log_fn(udev_ctx, priority, file, line, NULL, format, args);
  66         va_end(args);
  67         return;
  68 }
  69
  70 static int all_probers(volume_id_probe_fn_t probe_fn,
  71                        struct volume_id *id, uint64_t off, uint64_t size,
  72                        void *data)
  73 {
  74         const char *type;
  75
  76         if (probe_fn(id, off, size) == 0)
  77                 if (volume_id_get_type(id, &type))
  78                         printf("%s\n", type);
  79
  80         return 0;
  81 }
  82
  83 int main(int argc, char *argv[])
  84 {
  85         static const struct option options[] = {
  86                 { "label", no_argument, NULL, 'l' },
  87                 { "label-raw", no_argument, NULL, 'L' },
  88                 { "uuid", no_argument, NULL, 'u' },
  89                 { "type", no_argument, NULL, 't' },
  90                 { "export", no_argument, NULL, 'x' },
  91                 { "skip-raid", no_argument, NULL, 's' },
  92                 { "size", required_argument, NULL, 'S' },
  93                 { "probe-all", no_argument, NULL, 'a' },
  94                 { "offset", optional_argument, NULL, 'o' },
  95                 { "debug", no_argument, NULL, 'd' },
  96                 { "help", no_argument, NULL, 'h' },
  97                 {}
  98         };
  99
 100         enum print_type {
 101                 PRINT_EXPORT,
 102                 PRINT_TYPE,
 103                 PRINT_LABEL,
 104                 PRINT_UUID,
 105                 PRINT_LABEL_RAW,
 106         } print = PRINT_EXPORT;
 107
 108         struct volume_id *vid = NULL;
 109         char label_safe[256];
 110         char label_enc[256];
 111         char uuid_safe[256];
 112         char uuid_enc[256];
 113         char uuid_sub_enc[256];
 114         char type_enc[256];
 115         char type_version_enc[256];
 116         uint64_t size = 0;
 117         int skip_raid = 0;
 118         int probe_all = 0;
 119         uint64_t offset = 0;
 120         const char *node;
 121         int fd;
 122         const char *label, *uuid, *uuid_sub, *type, *type_version, *usage;
 123         int retval;
 124         int rc = 0;
 125
 126         udev_ctx = udev_new();
 127         if (udev_ctx == NULL)
 128                 goto exit;
 129         logging_init("vol_id");
 130         udev_set_log_fn(udev_ctx, log_fn);
 131
 132         /* hook in our debug into libvolume_id */
 133         volume_id_log_fn = vid_log;
 134
 135         while (1) {
 136                 int option;
 137
 138                 option = getopt_long(argc, argv, "lLutxsS:aodh", options, NULL);
 139                 if (option == -1)
 140                         break;
 141
 142                 switch (option) {
 143                 case 'd':
 144                         debug = 1;
 145                         if (udev_get_log_priority(udev_ctx) < LOG_INFO)
 146                                 udev_set_log_priority(udev_ctx, LOG_INFO);
 147                         break;
 148                 case 'l':
 149                         print = PRINT_LABEL;
 150                         break;
 151                 case 'L':
 152                         print = PRINT_LABEL_RAW;
 153                         break;
 154                 case 'u':
 155                         print = PRINT_UUID;
 156                         break;
 157                 case 't':
 158                         print = PRINT_TYPE;
 159                         break;
 160                 case 'x':
 161                         print = PRINT_EXPORT;
 162                         break;
 163                 case 's':
 164                         skip_raid = 1;
 165                         break;
 166                 case 'a':
 167                         probe_all = 1;
 168                         break;
 169                 case 'S':
 170                         if (optarg[0] != '\0')
 171                                 size = strtoull(optarg, NULL, 0);
 172                         break;
 173                 case 'o':
 174                         if (optarg[0] != '\0')
 175                                 offset = strtoull(optarg, NULL, 0);
 176                         break;
 177                 case 'h':
 178                         printf("Usage: vol_id [options] <device>\n"
 179                             " --export         export key/value pairs\n"
 180                             " --type           filesystem type\n"
 181                             " --label          filesystem label\n"
 182                             " --label-raw      raw label\n"
 183                             " --uuid           filesystem uuid\n"
 184                             " --skip-raid      don't probe for raid\n"
 185                             " --probe-all      find possibly conflicting signatures\n"
 186                             " --offset=<bytes> probe at the given offset\n"
 187                             " --size=<bytes>   overwrite device size\n"
 188                             " --debug          print debug output to stderr\n"
 189                             " --help\n\n");
 190                         goto exit;
 191                 default:
 192                         retval = 1;
 193                         goto exit;
 194                 }
 195         }
 196
 197         node = argv[optind];
 198         if (!node) {
 199                 err(udev_ctx, "no device\n");
 200                 fprintf(stderr, "no device\n");
 201                 rc = 1;
 202                 goto exit;
 203         }
 204
 205         fd = open(node, O_RDONLY);
 206         if (fd < 0) {
 207                 fprintf(stderr, "%s: error opening volume\n", node);
 208                 rc = 2;
 209                 goto exit;
 210         }
 211
 212         vid = volume_id_open_fd(fd);
 213         if (vid == NULL) {
 214                 rc = 2;
 215                 goto exit;
 216         }
 217
 218         if (size == 0) {
 219                 if (ioctl(fd, BLKGETSIZE64, &size) == 0) {
 220                         info(udev_ctx, "BLKGETSIZE64=%" PRIu64 " (%" PRIu64 "GB)\n", size, size >> 30);
 221                 } else {
 222                         struct stat statbuf;
 223
 224                         if (fstat(fd, &statbuf) == 0 && S_ISREG(statbuf.st_mode))
 225                                 size = statbuf.st_size;
 226                         else
 227                                 size = 0;
 228                         info(udev_ctx, "stat=%" PRIu64 " (%" PRIu64 "GB)\n", size, size >> 30);
 229                 }
 230         }
 231
 232         /* try to drop all privileges before reading disk content */
 233         if (getuid() == 0) {
 234                 struct passwd *pw;
 235
 236                 pw = getpwnam("nobody");
 237                 if (pw != NULL && pw->pw_uid > 0 && pw->pw_gid > 0) {
 238                         if (setgroups(0, NULL) != 0 ||
 239                             setgid(pw->pw_gid) != 0 ||
 240                             setuid(pw->pw_uid) != 0)
 241                                 info(udev_ctx, "unable to drop privileges: %s\n\n", strerror(errno));
 242                 }
 243         }
 244
 245         if (probe_all) {
 246                 volume_id_all_probers(all_probers, vid, offset, size, NULL);
 247                 goto exit;
 248         }
 249
 250         if (skip_raid)
 251                 retval = volume_id_probe_filesystem(vid, offset, size);
 252         else
 253                 retval = volume_id_probe_all(vid, offset, size);
 254         if (retval != 0) {
 255                 fprintf(stderr, "unknown or non-unique volume type "
 256                                 "(--probe-all lists possibly conflicting types)\n");
 257                 rc = 4;
 258                 goto exit;
 259         }
 260
 261         if (!volume_id_get_label(vid, &label) ||
 262             !volume_id_get_usage(vid, &usage) ||
 263             !volume_id_get_type(vid, &type) ||
 264             !volume_id_get_type_version(vid, &type_version) ||
 265             !volume_id_get_uuid(vid, &uuid) ||
 266             !volume_id_get_uuid_sub(vid, &uuid_sub)) {
 267                 rc = 4;
 268                 goto exit;
 269         }
 270
 271         udev_util_replace_whitespace(label, label_safe, sizeof(label_safe));
 272         udev_util_replace_chars(label_safe, UDEV_ALLOWED_CHARS_INPUT);
 273         volume_id_encode_string(label, label_enc, sizeof(label_enc));
 274
 275         udev_util_replace_whitespace(uuid, uuid_safe, sizeof(uuid_safe));
 276         udev_util_replace_chars(uuid_safe, UDEV_ALLOWED_CHARS_INPUT);
 277         volume_id_encode_string(uuid, uuid_enc, sizeof(uuid_enc));
 278
 279         volume_id_encode_string(uuid_sub, uuid_sub_enc, sizeof(uuid_sub_enc));
 280
 281         volume_id_encode_string(type, type_enc, sizeof(type_enc));
 282         volume_id_encode_string(type_version, type_version_enc, sizeof(type_version_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_enc);
 288                 printf("ID_FS_VERSION=%s\n", type_version_enc);
 289                 printf("ID_FS_UUID=%s\n", uuid_safe);
 290                 printf("ID_FS_UUID_ENC=%s\n", uuid_enc);
 291                 if (uuid_sub_enc[0] != '\0')
 292                         printf("ID_FS_UUID_SUB_ENC=%s\n", uuid_sub_enc);
 293                 printf("ID_FS_LABEL=%s\n", label_safe);
 294                 printf("ID_FS_LABEL_ENC=%s\n", label_enc);
 295                 break;
 296         case PRINT_TYPE:
 297                 printf("%s\n", type);
 298                 break;
 299         case PRINT_LABEL:
 300                 if (label_safe[0] == '\0' || strcmp(usage, "raid") == 0) {
 301                         rc = 3;
 302                         goto exit;
 303                 }
 304                 printf("%s\n", label_safe);
 305                 break;
 306         case PRINT_UUID:
 307                 if (uuid_enc[0] == '\0' || strcmp(usage, "raid") == 0) {
 308                         rc = 4;
 309                         goto exit;
 310                 }
 311                 printf("%s\n", uuid_enc);
 312                 break;
 313         case PRINT_LABEL_RAW:
 314                 if (label[0] == '\0' || strcmp(usage, "raid") == 0) {
 315                         rc = 3;
 316                         goto exit;
 317                 }
 318                 printf("%s\n", label);
 319                 break;
 320         }
 321
 322 exit:
 323         if (vid != NULL)
 324                 volume_id_close(vid);
 325         udev_unref(udev_ctx);
 326         logging_close();
 327         return rc;
 328 }