extras/volume_id/vol_id.c

   1 /*
   2  * vol_id - read filesystem label and uuid
   3  *
   4  * Copyright (C) 2005-2006 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.h"
  38 #include "lib/libvolume_id.h"
  39
  40 #define BLKGETSIZE64 _IOR(0x12,114,size_t)
  41
  42 #ifdef USE_LOG
  43 void log_message(int priority, const char *format, ...)
  44 {
  45         va_list args;
  46         static int udev_log = -1;
  47
  48         if (udev_log == -1) {
  49                 const char *value;
  50
  51                 value = getenv("UDEV_LOG");
  52                 if (value)
  53                         udev_log = log_priority(value);
  54                 else
  55                         udev_log = LOG_ERR;
  56         }
  57
  58         if (priority > udev_log)
  59                 return;
  60
  61         va_start(args, format);
  62         vsyslog(priority, format, args);
  63         va_end(args);
  64 }
  65 #endif
  66
  67 static void vid_log(int priority, const char *file, int line, const char *format, ...)
  68 {
  69 #ifdef USE_LOG
  70         char log_str[1024];
  71         va_list args;
  72
  73         va_start(args, format);
  74         vsnprintf(log_str, sizeof(log_str), format, args);
  75         log_str[sizeof(log_str)-1] = '\0';
  76         log_message(priority, "%s:%i %s", file, line, log_str);
  77         va_end(args);
  78 #endif
  79         return;
  80 }
  81
  82 static void set_str(char *to, const char *from, size_t count)
  83 {
  84         size_t i, j, len;
  85
  86         /* strip trailing whitespace */
  87         len = strnlen(from, count);
  88         while (len && isspace(from[len-1]))
  89                 len--;
  90
  91         /* strip leading whitespace */
  92         i = 0;
  93         while (isspace(from[i]) && (i < len))
  94                 i++;
  95
  96         j = 0;
  97         while (i < len) {
  98                 /* substitute multiple whitespace */
  99                 if (isspace(from[i])) {
 100                         while (isspace(from[i]))
 101                                 i++;
 102                         to[j++] = '_';
 103                 }
 104                 /* skip chars */
 105                 if (from[i] == '/') {
 106                         i++;
 107                         continue;
 108                 }
 109                 to[j++] = from[i++];
 110         }
 111         to[j] = '\0';
 112 }
 113
 114 static int all_probers(volume_id_probe_fn_t probe_fn,
 115                        struct volume_id *id, uint64_t off, uint64_t size,
 116                        void *data)
 117 {
 118         const char *type;
 119
 120         if (probe_fn(id, off, size) == 0)
 121                 if (volume_id_get_type(id, &type))
 122                         printf("%s\n", type);
 123
 124         return 0;
 125 }
 126
 127 int main(int argc, char *argv[])
 128 {
 129         static const struct option options[] = {
 130                 { "label", 0, NULL, 'l' },
 131                 { "label-raw", 0, NULL, 'L' },
 132                 { "uuid", 0, NULL, 'u' },
 133                 { "type", 0, NULL, 't' },
 134                 { "export", 0, NULL, 'x' },
 135                 { "skip-raid", 0, NULL, 's' },
 136                 { "probe-all", 0, NULL, 'a' },
 137                 { "help", 0, NULL, 'h' },
 138                 {}
 139         };
 140
 141         enum print_type {
 142                 PRINT_EXPORT,
 143                 PRINT_TYPE,
 144                 PRINT_LABEL,
 145                 PRINT_UUID,
 146                 PRINT_LABEL_RAW,
 147         } print = PRINT_EXPORT;
 148
 149         struct volume_id *vid = NULL;
 150         char label_safe[256];
 151         char label_enc[256];
 152         char uuid_enc[256];
 153         uint64_t size;
 154         int skip_raid = 0;
 155         int probe_all = 0;
 156         const char *node;
 157         struct passwd *pw;
 158         int fd;
 159         const char *label, *uuid, *type, *type_version, *usage;
 160         int retval;
 161         int rc = 0;
 162
 163         logging_init("vol_id");
 164
 165         /* hook in our debug into libvolume_id */
 166         volume_id_log_fn = vid_log;
 167
 168         while (1) {
 169                 int option;
 170
 171                 option = getopt_long(argc, argv, "lLutxsah", options, NULL);
 172                 if (option == -1)
 173                         break;
 174
 175                 switch (option) {
 176                 case 'l':
 177                         print = PRINT_LABEL;
 178                         break;
 179                 case 'L':
 180                         print = PRINT_LABEL_RAW;
 181                         break;
 182                 case 'u':
 183                         print = PRINT_UUID;
 184                         break;
 185                 case 't':
 186                         print = PRINT_TYPE;
 187                         break;
 188                 case 'x':
 189                         print = PRINT_EXPORT;
 190                         break;
 191                 case 's':
 192                         skip_raid = 1;
 193                         break;
 194                 case 'a':
 195                         probe_all = 1;
 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                             " --help\n\n");
 207                         goto exit;
 208                 default:
 209                         retval = 1;
 210                         goto exit;
 211                 }
 212         }
 213
 214         node = argv[optind];
 215         if (!node) {
 216                 err("no device");
 217                 fprintf(stderr, "no device\n");
 218                 rc = 1;
 219                 goto exit;
 220         }
 221
 222         fd = open(node, O_RDONLY);
 223         if (fd < 0) {
 224                 fprintf(stderr, "%s: error opening volume\n", node);
 225                 rc = 2;
 226                 goto exit;
 227         }
 228
 229         vid = volume_id_open_fd(fd);
 230         if (vid == NULL) {
 231                 rc = 2;
 232                 goto exit;
 233         }
 234
 235         if (ioctl(fd, BLKGETSIZE64, &size) != 0)
 236                 size = 0;
 237         dbg("BLKGETSIZE64=%llu", (unsigned long long)size);
 238
 239         /* try to drop all privileges before reading disk content */
 240         pw = getpwnam ("nobody");
 241         if (pw != NULL && pw->pw_uid > 0 && pw->pw_gid > 0) {
 242                 dbg("dropping privileges to %u:%u",
 243                     (unsigned int)pw->pw_uid, (unsigned int)pw->pw_gid);
 244                 if (setgroups(0, NULL) != 0 ||
 245                     setgid(pw->pw_gid) != 0 ||
 246                     setuid(pw->pw_uid) != 0) {
 247                         fprintf(stderr, "error dropping privileges: %s\n", strerror(errno));
 248                         rc = 3;
 249                         goto exit;
 250                 }
 251         }
 252
 253         if (probe_all) {
 254                 volume_id_all_probers(all_probers, vid, 0, size, NULL);
 255                 goto exit;
 256         }
 257
 258         if (skip_raid)
 259                 retval = volume_id_probe_filesystem(vid, 0, size);
 260         else
 261                 retval = volume_id_probe_all(vid, 0, 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         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
 324         logging_close();
 325         return rc;
 326 }