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         va_start(args, format);
  61         udev_log(udev_ctx, 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         static const struct option options[] = {
 114                 { "label", no_argument, NULL, 'l' },
 115                 { "label-raw", no_argument, NULL, 'L' },
 116                 { "uuid", no_argument, NULL, 'u' },
 117                 { "type", no_argument, NULL, 't' },
 118                 { "export", no_argument, NULL, 'x' },
 119                 { "skip-raid", no_argument, NULL, 's' },
 120                 { "probe-all", no_argument, NULL, 'a' },
 121                 { "offset", optional_argument, NULL, 'o' },
 122                 { "debug", no_argument, NULL, 'd' },
 123                 { "help", no_argument, NULL, 'h' },
 124                 {}
 125         };
 126
 127         enum print_type {
 128                 PRINT_EXPORT,
 129                 PRINT_TYPE,
 130                 PRINT_LABEL,
 131                 PRINT_UUID,
 132                 PRINT_LABEL_RAW,
 133         } print = PRINT_EXPORT;
 134
 135         struct volume_id *vid = NULL;
 136         char label_safe[256];
 137         char label_enc[256];
 138         char uuid_enc[256];
 139         uint64_t size;
 140         int skip_raid = 0;
 141         int probe_all = 0;
 142         uint64_t offset = 0;
 143         const char *node;
 144         int fd;
 145         const char *label, *uuid, *type, *type_version, *usage;
 146         int retval;
 147         int rc = 0;
 148
 149         udev_ctx = udev_new();
 150         if (udev_ctx == NULL)
 151                 goto exit;
 152         logging_init("vol_id");
 153         udev_set_log_fn(udev_ctx, log_fn);
 154
 155         /* hook in our debug into libvolume_id */
 156         volume_id_log_fn = vid_log;
 157
 158         while (1) {
 159                 int option;
 160
 161                 option = getopt_long(argc, argv, "lLutxsaodh", options, NULL);
 162                 if (option == -1)
 163                         break;
 164
 165                 switch (option) {
 166                 case 'd':
 167                         debug = 1;
 168                         if (udev_get_log_priority(udev_ctx) < LOG_INFO)
 169                                 udev_set_log_priority(udev_ctx, LOG_INFO);
 170                         break;
 171                 case 'l':
 172                         print = PRINT_LABEL;
 173                         break;
 174                 case 'L':
 175                         print = PRINT_LABEL_RAW;
 176                         break;
 177                 case 'u':
 178                         print = PRINT_UUID;
 179                         break;
 180                 case 't':
 181                         print = PRINT_TYPE;
 182                         break;
 183                 case 'x':
 184                         print = PRINT_EXPORT;
 185                         break;
 186                 case 's':
 187                         skip_raid = 1;
 188                         break;
 189                 case 'a':
 190                         probe_all = 1;
 191                         break;
 192                 case 'o':
 193                         if (optarg[0] != '\0')
 194                                 offset = strtoull(optarg, NULL, 0);
 195                         break;
 196                 case 'h':
 197                         printf("Usage: vol_id [options] <device>\n"
 198                             " --export         export key/value pairs\n"
 199                             " --type           filesystem type\n"
 200                             " --label          filesystem label\n"
 201                             " --label-raw      raw label\n"
 202                             " --uuid           filesystem uuid\n"
 203                             " --skip-raid      don't probe for raid\n"
 204                             " --probe-all      find possibly conflicting signatures\n"
 205                             " --offset=<bytes> probe at the given offset\n"
 206                             " --debug          print debug output to stderr\n"
 207                             " --help\n\n");
 208                         goto exit;
 209                 default:
 210                         retval = 1;
 211                         goto exit;
 212                 }
 213         }
 214
 215         node = argv[optind];
 216         if (!node) {
 217                 err(udev_ctx, "no device\n");
 218                 fprintf(stderr, "no device\n");
 219                 rc = 1;
 220                 goto exit;
 221         }
 222
 223         fd = open(node, O_RDONLY);
 224         if (fd < 0) {
 225                 fprintf(stderr, "%s: error opening volume\n", node);
 226                 rc = 2;
 227                 goto exit;
 228         }
 229
 230         vid = volume_id_open_fd(fd);
 231         if (vid == NULL) {
 232                 rc = 2;
 233                 goto exit;
 234         }
 235
 236         if (ioctl(fd, BLKGETSIZE64, &size) != 0)
 237                 size = 0;
 238         info(udev_ctx, "BLKGETSIZE64=%llu (%lluGB)\n", (unsigned long long)size, (unsigned long long)size >> 30);
 239
 240         /* try to drop all privileges before reading disk content */
 241         if (getuid() == 0) {
 242                 struct passwd *pw;
 243
 244                 pw = getpwnam("nobody");
 245                 if (pw != NULL && pw->pw_uid > 0 && pw->pw_gid > 0) {
 246                         if (setgroups(0, NULL) != 0 ||
 247                             setgid(pw->pw_gid) != 0 ||
 248                             setuid(pw->pw_uid) != 0)
 249                                 info(udev_ctx, "unable to drop privileges: %s\n\n", strerror(errno));
 250                 }
 251         }
 252
 253         if (probe_all) {
 254                 volume_id_all_probers(all_probers, vid, offset, size, NULL);
 255                 goto exit;
 256         }
 257
 258         if (skip_raid)
 259                 retval = volume_id_probe_filesystem(vid, offset, size);
 260         else
 261                 retval = volume_id_probe_all(vid, offset, size);
 262         if (retval != 0) {
 263                 fprintf(stderr, "%s: unknown volume type\n", node);
 264                 rc = 4;
 265                 goto exit;
 266         }
 267
 268         if (!volume_id_get_label(vid, &label) ||
 269             !volume_id_get_usage(vid, &usage) ||
 270             !volume_id_get_type(vid, &type) ||
 271             !volume_id_get_type_version(vid, &type_version) ||
 272             !volume_id_get_uuid(vid, &uuid)) {
 273                 rc = 4;
 274                 goto exit;
 275         }
 276
 277         set_str(label_safe, label, sizeof(label_safe));
 278         util_replace_chars(label_safe, ALLOWED_CHARS_INPUT);
 279
 280         volume_id_encode_string(label, label_enc, sizeof(label_enc));
 281         volume_id_encode_string(uuid, uuid_enc, sizeof(uuid_enc));
 282
 283         switch (print) {
 284         case PRINT_EXPORT:
 285                 printf("ID_FS_USAGE=%s\n", usage);
 286                 printf("ID_FS_TYPE=%s\n", type);
 287                 printf("ID_FS_VERSION=%s\n", type_version);
 288                 printf("ID_FS_UUID=%s\n", uuid);
 289                 printf("ID_FS_UUID_ENC=%s\n", uuid_enc);
 290                 printf("ID_FS_LABEL=%s\n", label);
 291                 printf("ID_FS_LABEL_ENC=%s\n", label_enc);
 292                 printf("ID_FS_LABEL_SAFE=%s\n", label_safe);
 293                 break;
 294         case PRINT_TYPE:
 295                 printf("%s\n", type);
 296                 break;
 297         case PRINT_LABEL:
 298                 if (label_safe[0] == '\0' || strcmp(usage, "raid") == 0) {
 299                         rc = 3;
 300                         goto exit;
 301                 }
 302                 printf("%s\n", label_safe);
 303                 break;
 304         case PRINT_UUID:
 305                 if (uuid_enc[0] == '\0' || strcmp(usage, "raid") == 0) {
 306                         rc = 4;
 307                         goto exit;
 308                 }
 309                 printf("%s\n", uuid_enc);
 310                 break;
 311         case PRINT_LABEL_RAW:
 312                 if (label[0] == '\0' || strcmp(usage, "raid") == 0) {
 313                         rc = 3;
 314                         goto exit;
 315                 }
 316                 printf("%s\n", label);
 317                 break;
 318         }
 319
 320 exit:
 321         if (vid != NULL)
 322                 volume_id_close(vid);
 323         udev_unref(udev_ctx);
 324         logging_close();
 325         return rc;
 326 }