plugins/partitioning/virtual-disk.h

   1 /* nbdkit
   2  * Copyright Red Hat
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions are
   6  * met:
   7  *
   8  * * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  * * Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  *
  15  * * Neither the name of Red Hat nor the names of its contributors may be
  16  * used to endorse or promote products derived from this software without
  17  * specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  22  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  26  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  27  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  28  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  29  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #ifndef NBDKIT_VIRTUAL_DISK_H
  34 #define NBDKIT_VIRTUAL_DISK_H
  35
  36 #include <stdbool.h>
  37 #include <sys/types.h>
  38 #include <sys/stat.h>
  39
  40 #include "rounding.h"
  41
  42 #include "gpt.h"
  43 #include "regions.h"
  44
  45 #define SECTOR_SIZE UINT64_C (512)
  46
  47 /* Maximum size of MBR disks.  This is an approximation based on the
  48  * known limit (2^32 sectors) and an estimate based on the amount of
  49  * padding between partitions.
  50  */
  51 #define MAX_MBR_DISK_SIZE (UINT32_MAX * SECTOR_SIZE - 5 * MAX_ALIGNMENT)
  52
  53 /* For GPT, the number of entries in the partition table array (PTA),
  54  * and the number of LBAs which the PTA occupies.  The latter will be
  55  * 32 if the number of files is <= GPT_MIN_PARTITIONS, which is the
  56  * normal case.
  57  */
  58 #define GPT_PTA_SIZE ROUND_UP (the_files.len, GPT_MIN_PARTITIONS)
  59 #define GPT_PTA_LBAs (GPT_PTA_SIZE * GPT_PT_ENTRY_SIZE / SECTOR_SIZE)
  60
  61 /* Maximum possible and default alignment between partitions. */
  62 #define MAX_ALIGNMENT (2048 * SECTOR_SIZE)
  63 #define DEFAULT_ALIGNMENT MAX_ALIGNMENT
  64
  65 /* Default MBR partition ID and GPT partition type GUID. */
  66 #define DEFAULT_MBR_ID 0x83
  67 #define DEFAULT_TYPE_GUID "0FC63DAF-8483-4772-8E79-3D69D8477DE4"
  68
  69 extern int partitioning_debug_regions;
  70
  71 extern unsigned long alignment;
  72 extern uint8_t mbr_id;
  73 extern char type_guid[16];
  74
  75 #define PARTTYPE_UNSET 0
  76 #define PARTTYPE_MBR   1
  77 #define PARTTYPE_GPT   2
  78 extern int parttype;
  79
  80 /* A file supplied on the command line. */
  81 struct file {
  82   const char *filename;         /* file= supplied on the command line */
  83   int fd;
  84   struct stat statbuf;
  85   char guid[16];                /* random GUID used for GPT */
  86   unsigned long alignment;      /* alignment of this partition */
  87   uint8_t mbr_id;               /* MBR ID of this partition */
  88   char type_guid[16];           /* partition type GUID of this partition */
  89 };
  90
  91 DEFINE_VECTOR_TYPE (files, struct file);
  92
  93 extern files the_files;
  94 extern regions the_regions;
  95 extern unsigned char *primary, *secondary, **ebr;
  96
  97 /* Main entry point called after files array has been populated. */
  98 extern int create_virtual_disk_layout (void);
  99
 100 /* Parse a GPT GUID.  Note that GPT GUIDs have peculiar
 101  * characteristics which make them unlike general GUIDs.
 102  */
 103 extern int parse_guid (const char *str, char *out)
 104   __attribute__ ((__nonnull__ (1, 2)));
 105
 106 /* Internal function for creating a single MBR PTE.  The GPT code
 107  * calls this for creating the protective MBR.
 108  */
 109 extern void create_mbr_partition_table_entry (const struct region *,
 110                                               bool bootable, int partition_id,
 111                                               unsigned char *)
 112   __attribute__ ((__nonnull__ (1, 4)));
 113
 114 /* Create MBR or GPT layout. */
 115 extern void create_mbr_layout (void);
 116 extern void create_gpt_layout (void);
 117
 118 #endif /* NBDKIT_VIRTUAL_DISK_H */