extras/volume_id/libvolume_id/mac.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 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
  11 #ifndef _GNU_SOURCE
  12 #define _GNU_SOURCE 1
  13 #endif
  14
  15 #ifdef HAVE_CONFIG_H
  16 #  include <config.h>
  17 #endif
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <unistd.h>
  22 #include <string.h>
  23 #include <errno.h>
  24 #include <ctype.h>
  25
  26 #include "volume_id.h"
  27 #include "logging.h"
  28 #include "util.h"
  29
  30 struct mac_driver_desc {
  31         uint8_t         signature[2];
  32         uint16_t        block_size;
  33         uint32_t        block_count;
  34 } __attribute__((__packed__));
  35
  36 struct mac_partition {
  37         uint8_t         signature[2];
  38         uint16_t        res1;
  39         uint32_t        map_count;
  40         uint32_t        start_block;
  41         uint32_t        block_count;
  42         uint8_t         name[32];
  43         uint8_t         type[32];
  44 } __attribute__((__packed__));
  45
  46 int volume_id_probe_mac_partition_map(struct volume_id *id, uint64_t off)
  47 {
  48         const uint8_t *buf;
  49         struct mac_driver_desc *driver;
  50         struct mac_partition *part;
  51
  52         dbg("probing at offset 0x%llx", (unsigned long long) off);
  53
  54         buf = volume_id_get_buffer(id, off, 0x200);
  55         if (buf == NULL)
  56                 return -1;
  57
  58         part = (struct mac_partition *) buf;
  59         if ((memcmp(part->signature, "PM", 2) == 0) &&
  60             (memcmp(part->type, "Apple_partition_map", 19) == 0)) {
  61                 /* linux creates an own subdevice for the map
  62                  * just return the type if the drive header is missing */
  63                 volume_id_set_usage(id, VOLUME_ID_PARTITIONTABLE);
  64                 id->type = "mac_partition_map";
  65                 return 0;
  66         }
  67
  68         driver = (struct mac_driver_desc *) buf;
  69         if (memcmp(driver->signature, "ER", 2) == 0) {
  70                 /* we are on a main device, like a CD
  71                  * just try to probe the first partition from the map */
  72                 unsigned int bsize = be16_to_cpu(driver->block_size);
  73                 int part_count;
  74                 int i;
  75
  76                 /* get first entry of partition table */
  77                 buf = volume_id_get_buffer(id, off +  bsize, 0x200);
  78                 if (buf == NULL)
  79                         return -1;
  80
  81                 part = (struct mac_partition *) buf;
  82                 if (memcmp(part->signature, "PM", 2) != 0)
  83                         return -1;
  84
  85                 part_count = be32_to_cpu(part->map_count);
  86                 dbg("expecting %d partition entries", part_count);
  87                 if (part_count < 1 || part_count > 256)
  88                         return -1;
  89
  90                 if (id->partitions != NULL)
  91                         free(id->partitions);
  92                 id->partitions = malloc(part_count * sizeof(struct volume_id_partition));
  93                 if (id->partitions == NULL)
  94                         return -1;
  95                 memset(id->partitions, 0x00, part_count * sizeof(struct volume_id_partition));
  96
  97                 id->partition_count = part_count;
  98
  99                 for (i = 0; i < part_count; i++) {
 100                         uint64_t poff;
 101                         uint64_t plen;
 102
 103                         buf = volume_id_get_buffer(id, off + ((i+1) * bsize), 0x200);
 104                         if (buf == NULL)
 105                                 return -1;
 106
 107                         part = (struct mac_partition *) buf;
 108                         if (memcmp(part->signature, "PM", 2) != 0)
 109                                 return -1;
 110
 111                         poff = be32_to_cpu(part->start_block) * bsize;
 112                         plen = be32_to_cpu(part->block_count) * bsize;
 113                         dbg("found '%s' partition entry at 0x%llx, len 0x%llx",
 114                             part->type, (unsigned long long) poff, (unsigned long long) plen);
 115
 116                         id->partitions[i].off = poff;
 117                         id->partitions[i].len = plen;
 118
 119                         if (memcmp(part->type, "Apple_Free", 10) == 0) {
 120                                 volume_id_set_usage_part(&id->partitions[i], VOLUME_ID_UNUSED);
 121                         } else if (memcmp(part->type, "Apple_partition_map", 19) == 0) {
 122                                 volume_id_set_usage_part(&id->partitions[i], VOLUME_ID_PARTITIONTABLE);
 123                         } else {
 124                                 volume_id_set_usage_part(&id->partitions[i], VOLUME_ID_UNPROBED);
 125                         }
 126                 }
 127                 volume_id_set_usage(id, VOLUME_ID_PARTITIONTABLE);
 128                 id->type = "mac_partition_map";
 129                 return 0;
 130         }
 131
 132         return -1;
 133 }