extras/volume_id/udev_volume_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 extern int optind;
  68
  69 int main(int argc, char *argv[])
  70 {
  71         const char help[] = "usage: udev_volume_id [-t|-l|-u] <device>\n"
  72                             "       -t filesystem type\n"
  73                             "       -l filesystem label\n"
  74                             "       -u filesystem uuid\n"
  75                             "\n";
  76         static const char short_options[] = "htlu";
  77         struct volume_id *vid = NULL;
  78         const char *device;
  79         char print = 'a';
  80         static char name[VOLUME_ID_LABEL_SIZE];
  81         int len, i, j;
  82         unsigned long long size;
  83         int rc = 1;
  84
  85         logging_init("udev_volume_id");
  86
  87         while (1) {
  88                 int option;
  89
  90                 option = getopt(argc, argv, short_options);
  91                 if (option == -1)
  92                         break;
  93
  94                 switch (option) {
  95                 case 't':
  96                         print = 't';
  97                         continue;
  98                 case 'l':
  99                         print = 'l';
 100                         continue;
 101                 case 'u':
 102                         print = 'u';
 103                         continue;
 104                 case 'h':
 105                 case '?':
 106                 default:
 107                         printf(help);
 108                         exit(1);
 109                 }
 110         }
 111
 112         device = argv[optind];
 113         if (device == NULL) {
 114                 printf(help);
 115                 exit(1);
 116         }
 117
 118         vid = volume_id_open_node(device);
 119         if (vid == NULL) {
 120                 printf("error open volume\n");
 121                 goto exit;
 122         }
 123
 124         if (ioctl(vid->fd, BLKGETSIZE64, &size) != 0)
 125                 size = 0;
 126
 127         if (volume_id_probe_all(vid, 0, size) == 0)
 128                 goto print;
 129
 130         if (volume_id_probe_dasd(vid) == 0)
 131                 goto print;
 132
 133         printf("unknown volume type\n");
 134         goto exit;
 135
 136
 137 print:
 138         len = strnlen(vid->label, VOLUME_ID_LABEL_SIZE);
 139
 140         /* remove trailing spaces */
 141         while (len > 0 && isspace(vid->label[len-1]))
 142                 len--;
 143         name[len] = '\0';
 144
 145         /* substitute chars */
 146         i = 0;
 147         j = 0;
 148         while (j < len) {
 149                 switch(vid->label[j]) {
 150                 case '/' :
 151                         break;
 152                 case ' ' :
 153                         name[i++] = '_';
 154                         break;
 155                 default :
 156                         name[i++] = vid->label[j];
 157                 }
 158                 j++;
 159         }
 160         name[i] = '\0';
 161
 162         switch (print) {
 163         case 't':
 164                 printf("%s\n", vid->type);
 165                 break;
 166         case 'l':
 167                 if (name[0] == '\0' ||
 168                     (vid->usage_id != VOLUME_ID_FILESYSTEM && vid->usage_id != VOLUME_ID_DISKLABEL)) {
 169                         rc = 2;
 170                         goto exit;
 171                 }
 172                 printf("%s\n", name);
 173                 break;
 174         case 'u':
 175                 if (vid->uuid[0] == '\0' || vid->usage_id != VOLUME_ID_FILESYSTEM) {
 176                         rc = 2;
 177                         goto exit;
 178                 }
 179                 printf("%s\n", vid->uuid);
 180                 break;
 181         case 'a':
 182                 printf("F:%s\n", vid->usage);
 183                 printf("T:%s\n", vid->type);
 184                 printf("V:%s\n", vid->type_version);
 185                 printf("L:%s\n", vid->label);
 186                 printf("N:%s\n", name);
 187                 printf("U:%s\n", vid->uuid);
 188         }
 189         rc = 0;
 190
 191 exit:
 192         if (vid != NULL)
 193                 volume_id_close(vid);
 194
 195         logging_close();
 196
 197         exit(rc);
 198 }