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 int all_probers(volume_id_probe_fn_t probe_fn,
  70                        struct volume_id *id, uint64_t off, uint64_t size,
  71                        void *data)
  72 {
  73         const char *type;
  74
  75         if (probe_fn(id, off, size) == 0)
  76                 if (volume_id_get_type(id, &type))
  77                         printf("%s\n", type);
  78
  79         return 0;
  80 }
  81
  82 int main(int argc, char *argv[])
  83 {
  84         static const struct option options[] = {
  85                 { "label", no_argument, NULL, 'l' },
  86                 { "label-raw", no_argument, NULL, 'L' },
  87                 { "uuid", no_argument, NULL, 'u' },
  88                 { "type", no_argument, NULL, 't' },
  89                 { "export", no_argument, NULL, 'x' },
  90                 { "skip-raid", no_argument, NULL, 's' },
  91                 { "size", required_argument, NULL, 'S' },
  92                 { "probe-all", no_argument, NULL, 'a' },
  93                 { "offset", optional_argument, NULL, 'o' },
  94                 { "debug", no_argument, NULL, 'd' },
  95                 { "help", no_argument, NULL, 'h' },
  96                 {}
  97         };
  98
  99         enum print_type {
 100                 PRINT_EXPORT,
 101                 PRINT_TYPE,
 102                 PRINT_LABEL,
 103                 PRINT_UUID,
 104                 PRINT_LABEL_RAW,
 105         } print = PRINT_EXPORT;
 106
 107         struct volume_id *vid = NULL;
 108         char label_safe[256];
 109         char label_enc[256];
 110         char uuid_safe[256];
 111         char uuid_enc[256];
 112         char type_enc[256];
 113         char type_version_enc[256];
 114         uint64_t size = 0;
 115         int skip_raid = 0;
 116         int probe_all = 0;
 117         uint64_t offset = 0;
 118         const char *node;
 119         int fd;
 120         const char *label, *uuid, *type, *type_version, *usage;
 121         int retval;
 122         int rc = 0;
 123
 124         udev_ctx = udev_new();
 125         if (udev_ctx == NULL)
 126                 goto exit;
 127         logging_init("vol_id");
 128         udev_set_log_fn(udev_ctx, log_fn);
 129
 130         /* hook in our debug into libvolume_id */
 131         volume_id_log_fn = vid_log;
 132
 133         while (1) {
 134                 int option;
 135
 136                 option = getopt_long(argc, argv, "lLutxsS:aodh", options, NULL);
 137                 if (option == -1)
 138                         break;
 139
 140                 switch (option) {
 141                 case 'd':
 142                         debug = 1;
 143                         if (udev_get_log_priority(udev_ctx) < LOG_INFO)
 144                                 udev_set_log_priority(udev_ctx, LOG_INFO);
 145                         break;
 146                 case 'l':
 147                         print = PRINT_LABEL;
 148                         break;
 149                 case 'L':
 150                         print = PRINT_LABEL_RAW;
 151                         break;
 152                 case 'u':
 153                         print = PRINT_UUID;
 154                         break;
 155                 case 't':
 156                         print = PRINT_TYPE;
 157                         break;
 158                 case 'x':
 159                         print = PRINT_EXPORT;
 160                         break;
 161                 case 's':
 162                         skip_raid = 1;
 163                         break;
 164                 case 'a':
 165                         probe_all = 1;
 166                         break;
 167                 case 'S':
 168                         if (optarg[0] != '\0')
 169                                 size = strtoull(optarg, NULL, 0);
 170                         break;
 171                 case 'o':
 172                         if (optarg[0] != '\0')
 173                                 offset = strtoull(optarg, NULL, 0);
 174                         break;
 175                 case 'h':
 176                         printf("Usage: vol_id [options] <device>\n"
 177                             " --export         export key/value pairs\n"
 178                             " --type           filesystem type\n"
 179                             " --label          filesystem label\n"
 180                             " --label-raw      raw label\n"
 181                             " --uuid           filesystem uuid\n"
 182                             " --skip-raid      don't probe for raid\n"
 183                             " --probe-all      find possibly conflicting signatures\n"
 184                             " --offset=<bytes> probe at the given offset\n"
 185                             " --size=<bytes>   overwrite device size\n"
 186                             " --debug          print debug output to stderr\n"
 187                             " --help\n\n");
 188                         goto exit;
 189                 default:
 190                         retval = 1;
 191                         goto exit;
 192                 }
 193         }
 194
 195         node = argv[optind];
 196         if (!node) {
 197                 err(udev_ctx, "no device\n");
 198                 fprintf(stderr, "no device\n");
 199                 rc = 1;
 200                 goto exit;
 201         }
 202
 203         fd = open(node, O_RDONLY);
 204         if (fd < 0) {
 205                 fprintf(stderr, "%s: error opening volume\n", node);
 206                 rc = 2;
 207                 goto exit;
 208         }
 209
 210         vid = volume_id_open_fd(fd);
 211         if (vid == NULL) {
 212                 rc = 2;
 213                 goto exit;
 214         }
 215
 216         if (size == 0) {
 217                 if (ioctl(fd, BLKGETSIZE64, &size) != 0)
 218                         size = 0;
 219                 info(udev_ctx, "BLKGETSIZE64=%" PRIu64 " (%" PRIu64 "GB)\n", size, size >> 30);
 220         }
 221
 222         /* try to drop all privileges before reading disk content */
 223         if (getuid() == 0) {
 224                 struct passwd *pw;
 225
 226                 pw = getpwnam("nobody");
 227                 if (pw != NULL && pw->pw_uid > 0 && pw->pw_gid > 0) {
 228                         if (setgroups(0, NULL) != 0 ||
 229                             setgid(pw->pw_gid) != 0 ||
 230                             setuid(pw->pw_uid) != 0)
 231                                 info(udev_ctx, "unable to drop privileges: %s\n\n", strerror(errno));
 232                 }
 233         }
 234
 235         if (probe_all) {
 236                 volume_id_all_probers(all_probers, vid, offset, size, NULL);
 237                 goto exit;
 238         }
 239
 240         if (skip_raid)
 241                 retval = volume_id_probe_filesystem(vid, offset, size);
 242         else
 243                 retval = volume_id_probe_all(vid, offset, size);
 244         if (retval != 0) {
 245                 fprintf(stderr, "%s: unknown volume type\n", node);
 246                 rc = 4;
 247                 goto exit;
 248         }
 249
 250         if (!volume_id_get_label(vid, &label) ||
 251             !volume_id_get_usage(vid, &usage) ||
 252             !volume_id_get_type(vid, &type) ||
 253             !volume_id_get_type_version(vid, &type_version) ||
 254             !volume_id_get_uuid(vid, &uuid)) {
 255                 rc = 4;
 256                 goto exit;
 257         }
 258
 259         udev_util_replace_whitespace(label, label_safe, sizeof(label_safe));
 260         udev_util_replace_chars(label_safe, UDEV_ALLOWED_CHARS_INPUT);
 261         volume_id_encode_string(label, label_enc, sizeof(label_enc));
 262
 263         udev_util_replace_whitespace(uuid, uuid_safe, sizeof(uuid_safe));
 264         udev_util_replace_chars(uuid_safe, UDEV_ALLOWED_CHARS_INPUT);
 265         volume_id_encode_string(uuid, uuid_enc, sizeof(uuid_enc));
 266
 267         volume_id_encode_string(type, type_enc, sizeof(type_enc));
 268         volume_id_encode_string(type_version, type_version_enc, sizeof(type_version_enc));
 269
 270         switch (print) {
 271         case PRINT_EXPORT:
 272                 printf("ID_FS_USAGE=%s\n", usage);
 273                 printf("ID_FS_TYPE=%s\n", type_enc);
 274                 printf("ID_FS_VERSION=%s\n", type_version_enc);
 275                 printf("ID_FS_UUID=%s\n", uuid_safe);
 276                 printf("ID_FS_UUID_ENC=%s\n", uuid_enc);
 277                 printf("ID_FS_LABEL=%s\n", label_safe);
 278                 printf("ID_FS_LABEL_ENC=%s\n", label_enc);
 279                 break;
 280         case PRINT_TYPE:
 281                 printf("%s\n", type);
 282                 break;
 283         case PRINT_LABEL:
 284                 if (label_safe[0] == '\0' || strcmp(usage, "raid") == 0) {
 285                         rc = 3;
 286                         goto exit;
 287                 }
 288                 printf("%s\n", label_safe);
 289                 break;
 290         case PRINT_UUID:
 291                 if (uuid_enc[0] == '\0' || strcmp(usage, "raid") == 0) {
 292                         rc = 4;
 293                         goto exit;
 294                 }
 295                 printf("%s\n", uuid_enc);
 296                 break;
 297         case PRINT_LABEL_RAW:
 298                 if (label[0] == '\0' || strcmp(usage, "raid") == 0) {
 299                         rc = 3;
 300                         goto exit;
 301                 }
 302                 printf("%s\n", label);
 303                 break;
 304         }
 305
 306 exit:
 307         if (vid != NULL)
 308                 volume_id_close(vid);
 309         udev_unref(udev_ctx);
 310         logging_close();
 311         return rc;
 312 }