/*      $NetBSD: partitions.c,v 1.13 2021/09/11 20:28:06 andvar Exp $   */

/*
* Copyright (c) 2020 The NetBSD Foundation, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

#include "defs.h"
#include "mbr.h"
#include <assert.h>

/*
* A list of partitioning schemes, so we can iterate over everything
* supported (e.g. when partitioning a new disk). NULL terminated.
*/
const struct disk_partitioning_scheme **available_part_schemes;
/*
* The number of valid entries on above list
*/
size_t num_available_part_schemes;

extern const struct disk_partitioning_scheme disklabel_parts;

/*
* Generic reader - query a disk device and read all partitions from it.
* disk_size is in units of physical sector size, which is passe as
* bytes_per_sec.
*/
struct disk_partitions *
partitions_read_disk(const char *dev, daddr_t disk_size, size_t bytes_per_sec,
   bool no_mbr)
{
       const struct disk_partitioning_scheme **ps;
#ifdef HAVE_MBR
       bool mbr_done = false, disklabel_done = false;
#endif

       if (!available_part_schemes)
               return NULL;

       for (ps = available_part_schemes; *ps; ps++) {
#ifdef HAVE_MBR
               if (!no_mbr && (*ps) == &disklabel_parts && !mbr_done)
                       continue;
               if (no_mbr && (*ps)->name == MSG_parttype_mbr)
                       continue;
               if ((*ps)->name == MSG_parttype_mbr)
                       mbr_done = true;
               if ((*ps)->read_from_disk == disklabel_parts.read_from_disk)
                       disklabel_done = true;
#endif
               struct disk_partitions *parts =
                   (*ps)->read_from_disk(dev, 0, disk_size, bytes_per_sec,
                       *ps);
               if (parts)
                       return parts;
       }
#ifdef HAVE_MBR
       if (!disklabel_done)
               return disklabel_parts.read_from_disk(dev, 0, disk_size,
                   bytes_per_sec, &disklabel_parts);
#endif
       return NULL;
}

bool
generic_adapt_foreign_part_info(const struct disk_partitions *myself,
   struct disk_part_info *dest,
   const struct disk_partitioning_scheme *src_scheme,
   const struct disk_part_info *src)
{
       *dest = *src;
       if (myself->pscheme == src_scheme)
               return true;    /* no conversion needed */

       if (src->nat_type == NULL)
               return false;

       /* slightly simplistic, enhance when needed */
       dest->nat_type = myself->pscheme->get_fs_part_type(
           dest->nat_type ? dest->nat_type->generic_ptype : PT_root,
           dest->fs_type,
           dest->fs_sub_type);
       if (dest->nat_type == NULL)
               dest->nat_type = myself->pscheme->get_generic_part_type(
                   src->nat_type->generic_ptype);
       if (dest->nat_type == NULL)
               dest->nat_type = myself->pscheme->create_unknown_part_type();
       if (dest->nat_type == NULL)
               dest->nat_type = myself->pscheme->get_generic_part_type(
                   PT_unknown);

       return true;
}

/*************** global init ****************************************/
/*
* Helper structure to fill our global list of available partitioning
* schemes.
*/
struct part_scheme_desc {
       bool (*is_available)(void);
       const struct disk_partitioning_scheme *ps;
};

#ifdef HAVE_GPT
bool gpt_parts_check(void);
extern const struct disk_partitioning_scheme gpt_parts;
#endif
#ifdef HAVE_MBR
extern const struct disk_partitioning_scheme mbr_parts;
#endif

#if RAW_PART == 3
static struct disk_partitioning_scheme only_disklabel_parts;

/*
* If not overridden by MD code, we can not boot from plain
* disklabel disks (w/o MBR).
*/
static bool have_only_disklabel_boot_support(const char *disk)
{
#ifdef HAVE_PLAIN_DISKLABEL_BOOT
       return HAVE_PLAIN_DISKLABEL_BOOT(disk);
#else
       return false;
#endif
}
#endif

/*
* One time initialization
*/
void
partitions_init(void)
{
       /*
        * List of partitioning schemes.
        * Order is important, the selection menu is created from start
        * to end. Keep good defaults early. Most architectures will
        * only offer very few entries.
        */
static const struct part_scheme_desc all_descs[] = {
#if RAW_PART != 3       /* only available as primary on some architectures */
               { NULL, &disklabel_parts },
#endif
#ifdef HAVE_GPT
               { gpt_parts_check, &gpt_parts },
#endif
#ifdef HAVE_MBR
               { NULL, &mbr_parts },
#endif
#if RAW_PART == 3       /* "whole disk NetBSD" disklabel variant */
               { NULL, &only_disklabel_parts },
#endif
       };

       size_t i, avail;
       const struct disk_partitioning_scheme **out;
       bool *is_available;
       static const size_t all_cnt = __arraycount(all_descs);

       check_available_binaries();

#if RAW_PART == 3
       /* generate a variant of disklabel w/o parent scheme */
       only_disklabel_parts = disklabel_parts;
       only_disklabel_parts.name = MSG_parttype_only_disklabel;
       only_disklabel_parts.have_boot_support =
           have_only_disklabel_boot_support;
#endif


       is_available = malloc(all_cnt);

       for (avail = i = 0; i < all_cnt; i++) {
               is_available[i] = all_descs[i].is_available == NULL
                               || all_descs[i].is_available();
               if (is_available[i])
                       avail++;
       }

       if (avail == 0)
               return;

       num_available_part_schemes = avail;
       available_part_schemes = malloc(sizeof(*available_part_schemes)
           * (avail+1));
       if (available_part_schemes == NULL)
               return;

       for (out = available_part_schemes, i = 0; i < all_cnt; i++) {
               if (!is_available[i])
                       continue;
               *out++ = all_descs[i].ps;
       }
       *out = NULL;

       free(is_available);
}

/*
* Final cleanup
*/
void
partitions_cleanup(void)
{
       for (size_t i = 0; i < num_available_part_schemes; i++)
               if (available_part_schemes[i]->cleanup != NULL)
                       available_part_schemes[i]->cleanup();
       free(available_part_schemes);
}

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