extras/volume_id/vol_id.c

   1 /*
   2  * udev_volume_id - udev callout to read filesystem label and uuid
   3  *
   4  * Copyright (C) 2005 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  *      sample udev rule for creation of a symlink with the filsystem uuid:
   7  *      KERNEL="sd*", PROGRAM="/sbin/udev_volume_id -u %N", SYMLINK="%c"
   8  *
   9  *      This program is free software; you can redistribute it and/or modify it
  10  *      under the terms of the GNU General Public License as published by the
  11  *      Free Software Foundation version 2 of the License.
  12  *
  13  *      This program is distributed in the hope that it will be useful, but
  14  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  *      General Public License for more details.
  17  *
  18  *      You should have received a copy of the GNU General Public License along
  19  *      with this program; if not, write to the Free Software Foundation, Inc.,
  20  *      675 Mass Ave, Cambridge, MA 02139, USA.
  21  *
  22  */
  23
  24 #ifndef _GNU_SOURCE
  25 #define _GNU_SOURCE 1
  26 #endif
  27
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <unistd.h>
  31 #include <string.h>
  32 #include <ctype.h>
  33 #include <sys/ioctl.h>
  34
  35 #include "../../udev_utils.h"
  36 #include "../../logging.h"
  37 #include "volume_id/volume_id.h"
  38 #include "volume_id/dasd.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 set_str(char *to, const unsigned char *from, int count)
  68 {
  69         int i, j;
  70         int len;
  71
  72         len = strnlen(from, count);
  73         while (isspace(from[len-1]))
  74                 len--;
  75
  76         i = 0;
  77         while (isspace(from[i]) && (i < len))
  78                 i++;
  79
  80         j = 0;
  81         while (i < len) {
  82                 switch(from[i]) {
  83                 case '/':
  84                         break;
  85                 case ' ':
  86                         to[j++] = '_';
  87                         break;
  88                 default:
  89                         to[j++] = from[i];
  90                 }
  91                 i++;
  92         }
  93         to[j] = '\0';
  94 }
  95
  96 int main(int argc, char *argv[])
  97 {
  98         const char help[] = "usage: udev_volume_id [--export|-t|-l|-u] <device>\n"
  99                             "       --export\n"
 100                             "       -t filesystem type\n"
 101                             "       -l filesystem label\n"
 102                             "       -u filesystem uuid\n"
 103                             "\n";
 104         enum print_type {
 105                 PRINT_EXPORT,
 106                 PRINT_TYPE,
 107                 PRINT_LABEL,
 108                 PRINT_UUID,
 109         } print = PRINT_EXPORT;
 110         struct volume_id *vid = NULL;
 111         static char name[VOLUME_ID_LABEL_SIZE];
 112         int i;
 113         unsigned long long size;
 114         const char *node = NULL;
 115         int rc = 0;
 116
 117         logging_init("udev_volume_id");
 118
 119         for (i = 1 ; i < argc; i++) {
 120                 char *arg = argv[i];
 121
 122                 if (strcmp(arg, "--export") == 0) {
 123                         print = PRINT_EXPORT;
 124                 } else if (strcmp(arg, "-t") == 0) {
 125                         print = PRINT_TYPE;
 126                 } else if (strcmp(arg, "-l") == 0) {
 127                         print = PRINT_LABEL;
 128                 } else if (strcmp(arg, "-u") == 0) {
 129                         print = PRINT_UUID;
 130                 } else
 131                         node = arg;
 132         }
 133         if (!node) {
 134                 err("no node specified");
 135                 fprintf(stderr, help);
 136                 rc = 1;
 137                 goto exit;
 138         }
 139
 140         vid = volume_id_open_node(node);
 141         if (vid == NULL) {
 142                 fprintf(stderr, "error open volume\n");
 143                 rc = 2;
 144                 goto exit;
 145         }
 146
 147         if (ioctl(vid->fd, BLKGETSIZE64, &size) != 0)
 148                 size = 0;
 149
 150         if (volume_id_probe_all(vid, 0, size) == 0)
 151                 goto print;
 152
 153         if (volume_id_probe_dasd(vid) == 0)
 154                 goto print;
 155
 156         fprintf(stderr, "unknown volume type\n");
 157         rc = 3;
 158         goto exit;
 159
 160 print:
 161         set_str(name, vid->label, sizeof(vid->label));
 162
 163         switch (print) {
 164         case PRINT_EXPORT:
 165                 printf("ID_FS_USAGE=%s\n", vid->usage);
 166                 printf("ID_FS_TYPE=%s\n", vid->type);
 167                 printf("ID_FS_VERSION=%s\n", vid->type_version);
 168                 printf("ID_FS_UUID=%s\n", vid->uuid);
 169                 printf("ID_FS_LABEL=%s\n", vid->label);
 170                 printf("ID_FS_LABEL_SAFE=%s\n", name);
 171                 break;
 172         case PRINT_TYPE:
 173                 printf("%s\n", vid->type);
 174                 break;
 175         case PRINT_LABEL:
 176                 if (name[0] == '\0' ||
 177                     (vid->usage_id != VOLUME_ID_FILESYSTEM && vid->usage_id != VOLUME_ID_DISKLABEL)) {
 178                         rc = 3;
 179                         goto exit;
 180                 }
 181                 printf("%s\n", name);
 182                 break;
 183         case PRINT_UUID:
 184                 if (vid->uuid[0] == '\0' || vid->usage_id != VOLUME_ID_FILESYSTEM) {
 185                         rc = 4;
 186                         goto exit;
 187                 }
 188                 printf("%s\n", vid->uuid);
 189                 break;
 190         }
 191
 192 exit:
 193         if (vid != NULL)
 194                 volume_id_close(vid);
 195
 196         logging_close();
 197         return rc;
 198 }