extras/volume_id/lib/cramfs.c

   1 /*
   2  * volume_id - reads filesystem label and uuid
   3  *
   4  * Copyright (C) 2004 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 <errno.h>
  29 #include <ctype.h>
  30
  31 #include "libvolume_id.h"
  32 #include "libvolume_id-private.h"
  33
  34 struct cramfs_super {
  35         uint8_t         magic[4];
  36         uint32_t        size;
  37         uint32_t        flags;
  38         uint32_t        future;
  39         uint8_t         signature[16];
  40         struct cramfs_info {
  41                 uint32_t        crc;
  42                 uint32_t        edition;
  43                 uint32_t        blocks;
  44                 uint32_t        files;
  45         } PACKED info;
  46         uint8_t         name[16];
  47 } PACKED;
  48
  49 int volume_id_probe_cramfs(struct volume_id *id, uint64_t off, uint64_t size)
  50 {
  51         struct cramfs_super *cs;
  52
  53         info("probing at offset 0x%llx\n", (unsigned long long) off);
  54
  55         cs = (struct cramfs_super *) volume_id_get_buffer(id, off, 0x200);
  56         if (cs == NULL)
  57                 return -1;
  58
  59         if (memcmp(cs->magic, "\x45\x3d\xcd\x28", 4) == 0 || memcmp(cs->magic, "\x28\xcd\x3d\x45", 4) == 0) {
  60                 volume_id_set_label_raw(id, cs->name, 16);
  61                 volume_id_set_label_string(id, cs->name, 16);
  62
  63                 volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
  64                 id->type = "cramfs";
  65                 return 0;
  66         }
  67
  68         return -1;
  69 }