/*	$OpenBSD: partition_map.c,v 1.99 2019/07/31 00:14:10 krw Exp $	*/

/*
 * partition_map.c - partition map routines
 *
 * Written by Eryk Vershen
 */

/*
 * Copyright 1996,1997,1998 by Apple Computer, Inc.
 *              All Rights Reserved
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose and without fee is hereby granted,
 * provided that the above copyright notice appears in all copies and
 * that both the copyright notice and this permission notice appear in
 * supporting documentation.
 *
 * APPLE COMPUTER DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE.
 *
 * IN NO EVENT SHALL APPLE COMPUTER BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
 * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/queue.h>
#include <sys/stdint.h>

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "partition_map.h"
#include "io.h"
#include "file_media.h"

#define APPLE_HFS_FLAGS_VALUE	0x4000037f

const char     *kFreeType = "Apple_Free";
const char     *kMapType = "Apple_partition_map";
const char     *kUnixType = "OpenBSD";
const char     *kHFSType = "Apple_HFS";

void		combine_entry(struct entry *);
struct entry   *create_entry(struct partition_map *, long, const char *,
    const char *, uint32_t, uint32_t);
void		delete_entry(struct entry *);
void		insert_in_base_order(struct entry *);
void		insert_in_disk_order(struct entry *);
int		read_partition_map(struct partition_map *);
void		remove_driver(struct entry *);
void		renumber_disk_addresses(struct partition_map *);

struct partition_map *
open_partition_map(int fd, char *name, uint64_t mediasz, uint32_t sectorsz)
{
	struct partition_map *map;
	int ok;

	map = malloc(sizeof(struct partition_map));
	if (map == NULL)
		errx(1, "No memory to open partition map");

	map->fd = fd;
	map->name = name;

	map->changed = 0;
	LIST_INIT(&map->disk_order);
	LIST_INIT(&map->base_order);
	map->blocks_in_map = 0;
	map->maximum_in_map = -1;

	if (mediasz > UINT32_MAX)
		map->media_size = UINT32_MAX;
	else
		map->media_size = mediasz;

	if (read_block0(map->fd, map) == 0) {
		warnx("Can't read block 0 from '%s'", name);
		free_partition_map(map);
		return NULL;
	}
	if (map->sbSig == BLOCK0_SIGNATURE &&
	    map->sbBlkSize == sectorsz &&
	    map->sbBlkCount <= mediasz) {
		if (read_partition_map(map) == 0)
			return map;
	} else {
		if (map->sbSig != BLOCK0_SIGNATURE)
			warnx("Block 0 signature: Expected 0x%04x, "
			    "got 0x%04x", BLOCK0_SIGNATURE,
			    map->sbSig);
		else if (map->sbBlkSize != sectorsz)
			warnx("Block 0 sbBlkSize (%u) != sector size (%u)",
			    map->sbBlkSize, sectorsz);
		else if (map->sbBlkCount > mediasz)
			warnx("Block 0 sbBlkCount (%u) > media size (%llu)",
			    map->sbBlkCount,
			    (unsigned long long)mediasz);
	}

	if (!lflag) {
		my_ungetch('\n');
		printf("No valid partition map found on '%s'.\n", name);
		ok = get_okay("Create default map? [n/y]: ", 0);
		flush_to_newline(0);
		if (ok == 1) {
			free_partition_map(map);
			map = create_partition_map(fd, name, mediasz, sectorsz);
			if (map)
				return map;
		}
	}

	free_partition_map(map);
	return NULL;
}


void
free_partition_map(struct partition_map *map)
{
	struct entry *entry;

	if (map == NULL)
		return;

	while (!LIST_EMPTY(&map->disk_order)) {
		entry = LIST_FIRST(&map->disk_order);
		LIST_REMOVE(entry, disk_entry);
		free(entry);
	}

	free(map);
}

int
read_partition_map(struct partition_map *map)
{
	struct entry *cur, *nextcur;
	struct entry *entry;
	int ix;
	uint32_t limit, base, next, nextbase;

	limit = 1; /* There has to be at least one, which has the real limit. */
	for (ix = 1; ix <= limit; ix++) {
		entry = malloc(sizeof(struct entry));
		if (entry == NULL)
			errx(1, "No memory for partition entry");
		if (read_dpme(map->fd, ix, entry) == 0) {
			warnx("Can't read block %u from '%s'", ix, map->name);
			free(entry);
			return 1;
		}
		if (entry->dpme_signature != DPME_SIGNATURE) {
			warnx("Invalid signature on block %d. Expected %x, "
			    "got %x", ix, DPME_SIGNATURE,
			    entry->dpme_signature);
			free(entry);
			return 1;
		}
		if (ix == 1) {
			if (entry->dpme_map_entries > entry->dpme_pblocks) {
				warnx("Map entry count (%u) > # of physical "
				    "blocks (%u)", entry->dpme_map_entries,
				    entry->dpme_pblocks);
				free(entry);
				return 1;
			}
			if (entry->dpme_map_entries == 0) {
				warnx("Map entry count ==  0. Must be > 0");
				free(entry);
				return 1;
			}
			map->maximum_in_map = entry->dpme_pblocks;
			limit = entry->dpme_map_entries;
		}
		if (limit != entry->dpme_map_entries) {
			warnx("Invalid entry count on block %d. "
			    "Expected %d, got %d", ix, limit,
			    entry->dpme_map_entries);
			free(entry);
			return 1;
		}
		if (entry->dpme_lblock_start >= entry->dpme_pblocks) {
			warnx("\tlogical start (%u) >= block count"
			    "count (%u).", entry->dpme_lblock_start,
			    entry->dpme_pblocks);
			free(entry);
			return 1;
		}
		if (entry->dpme_lblocks > entry->dpme_pblocks -
			entry->dpme_lblock_start) {
			warnx("\tlogical blocks (%u) > available blocks (%u).",
			    entry->dpme_lblocks,
			    entry->dpme_pblocks - entry->dpme_lblock_start);
			free(entry);
			return 1;
		}
		entry->the_map = map;
		entry->disk_address = ix;
		insert_in_disk_order(entry);
		insert_in_base_order(entry);
		map->blocks_in_map++;
	}

	/* Traverse base_order looking for
	 *
	 * 1) Overlapping partitions
	 * 2) Unmapped space
	 */
	LIST_FOREACH(cur, &map->base_order, base_entry) {
		base = cur->dpme_pblock_start;
		next = base + cur->dpme_pblocks;
		if (base >= map->media_size ||
		    next < base ||
		    next > map->media_size) {
			warnx("Partition extends past end of disk: %u -> %u",
			    base, next);
		}
		nextcur = LIST_NEXT(cur, base_entry);
		if (nextcur)
			nextbase = nextcur->dpme_pblock_start;
		else
			nextbase = map->media_size;
		if (next != nextbase)
			warnx("Unmapped pblocks: %u -> %u", next, nextbase);
		if (next > nextbase)
			warnx("Partition %ld overlaps next partition",
			    cur->disk_address);
	}

	return 0;
}


void
write_partition_map(struct partition_map *map)
{
	struct entry *entry;
	int result;

	result = write_block0(map->fd, map);
	if (result == 0)
		warn("Unable to write block zero");

	LIST_FOREACH(entry, &map->disk_order, disk_entry) {
		result = write_dpme(map->fd, entry->disk_address, entry);
		if (result == 0)
			warn("Unable to write block %ld", entry->disk_address);
	}
}


struct partition_map *
create_partition_map(int fd, char *name, u_int64_t mediasz, uint32_t sectorsz)
{
	struct partition_map *map;
	struct entry *entry;

	map = malloc(sizeof(struct partition_map));
	if (map == NULL)
		errx(1, "No memory to create partition map");

	map->name = name;
	map->fd = fd;
	map->changed = 1;
	LIST_INIT(&map->disk_order);
	LIST_INIT(&map->base_order);

	map->blocks_in_map = 0;
	map->maximum_in_map = -1;
	map->media_size = mediasz;

	map->sbSig = BLOCK0_SIGNATURE;
	map->sbBlkSize = sectorsz;
	map->sbBlkCount = map->media_size;

	entry = create_entry(map, 1, "", kFreeType, 1, mediasz - 1);
	if (entry == NULL)
		errx(1, "No memory for new dpme");

	add_partition_to_map("Apple", kMapType, 1,
	    (map->media_size <= 128 ? 2 : 63), map);

	return map;
}


int
add_partition_to_map(const char *name, const char *dptype, uint32_t base,
    uint32_t length, struct partition_map *map)
{
	struct entry *cur;
	int limit, new_entries;
	uint32_t old_base, old_length, old_address;
	uint32_t new_base, new_length;

	if (map->maximum_in_map < 0)
		limit = map->media_size;
	else
		limit = map->maximum_in_map;

	/* find a block of free space that starts includes base and length */
	LIST_FOREACH(cur, &map->base_order, base_entry) {
		if (strncasecmp(cur->dpme_type, kFreeType, DPISTRLEN))
		    continue;
		if (cur->dpme_pblock_start <= base &&
		    (base + length) <=
		    (cur->dpme_pblock_start + cur->dpme_pblocks))
			break;
	}
	if (cur == NULL) {
		printf("requested base and length is not "
		       "within an existing free partition\n");
		return 0;
	}
	old_base = cur->dpme_pblock_start;
	old_length = cur->dpme_pblocks;
	old_address = cur->disk_address;

	/* Check that there is enough room in the map for the new entries! */
	if (base == old_base && length == old_length)
		new_entries = 0;
	else if (base == old_base)
		new_entries = 1;
	else if (base - old_base < old_length - length)
		new_entries = 2;
	else
		new_entries = 1;
	if (map->blocks_in_map + new_entries > limit) {
		printf("the map is not big enough\n");
		return 0;
	}

	/*
	 * Delete old free entry from map and add back 1 to 3 new entries.
	 *
	 * 1) Empty space from base+len to old end.
	 * 2) New entry from specified base for length.
	 * 3) Empty space from old base to new base.
	 *
	 *  All with the same disk address, so they must be added in that
	 *  order!
	 */
	delete_entry(cur);

	new_base = base + length;
	new_length = (old_base + old_length) - new_base;
	if (new_length > 0) {
		/* New free space entry *after* new partition. */
		cur = create_entry(map, old_address, "", kFreeType, new_base,
		    new_length);
		if (cur == NULL)
			errx(1, "No memory for new dpme");
	}

	cur = create_entry(map, old_address, name, dptype, base, length);
	if (cur == NULL)
		errx(1, "No memory for new entry");

	new_length = base - old_base;
	if (new_length > 0) {
		/* New free space entry *before* new partition. */
		cur = create_entry(map, old_address, "", kFreeType, old_base,
		    new_length);
		if (cur == NULL)
			errx(1, "No memory for new entry");
	}

	renumber_disk_addresses(map);
	map->changed = 1;
	return 1;
}


struct entry*
create_entry(struct partition_map *map, long ix, const char *name,
    const char *dptype, uint32_t base, uint32_t length)
{
	struct entry *entry;

	entry = calloc(1, sizeof(struct entry));
	if (entry == NULL)
		errx(1, "No memory for new entry");

	entry->dpme_signature = DPME_SIGNATURE;
	entry->dpme_map_entries = 1;
	entry->dpme_pblock_start = base;
	entry->dpme_pblocks = length;
	strlcpy(entry->dpme_name, name, sizeof(entry->dpme_name));
	strlcpy(entry->dpme_type, dptype, sizeof(entry->dpme_type));
	if (strncasecmp(dptype, kFreeType, DPISTRLEN)) {
		/* Only non-kFreeType entries get lblock info != 0. */
		entry->dpme_lblocks = entry->dpme_pblocks;
	}
	dpme_init_flags(entry);

	entry->disk_address = ix;
	entry->the_map = map;

	insert_in_disk_order(entry);
	insert_in_base_order(entry);

	map->blocks_in_map++;
	if (map->maximum_in_map < 0) {
		if (strncasecmp(entry->dpme_type, kMapType, DPISTRLEN) == 0)
			map->maximum_in_map = entry->dpme_pblocks;
	}

	return entry;
}

void
dpme_init_flags(struct entry *entry)
{
	if (strncasecmp(entry->dpme_type, kFreeType, DPISTRLEN) == 0)
		entry->dpme_flags = 0;
	else if (strncasecmp(entry->dpme_type, kMapType, DPISTRLEN) == 0)
		entry->dpme_flags = DPME_VALID | DPME_ALLOCATED;
	else if (strncasecmp(entry->dpme_type, kHFSType, DPISTRLEN) == 0)
		entry->dpme_flags = APPLE_HFS_FLAGS_VALUE;
	else
		entry->dpme_flags = DPME_VALID | DPME_ALLOCATED |
		    DPME_READABLE | DPME_WRITABLE;
}

void
renumber_disk_addresses(struct partition_map *map)
{
	struct entry *cur;
	long ix;

	/* reset disk addresses */
	ix = 1;
	LIST_FOREACH(cur, &map->disk_order, disk_entry) {
		cur->disk_address = ix++;
		cur->dpme_map_entries = map->blocks_in_map;
	}
}

void
delete_partition_from_map(struct entry *entry)
{
	struct partition_map *map;
	uint32_t base, length, address;

	if (strncasecmp(entry->dpme_type, kMapType, DPISTRLEN) == 0) {
		printf("Can't delete entry for the map itself\n");
		return;
	}
	if (strncasecmp(entry->dpme_type, kFreeType, DPISTRLEN) == 0) {
		printf("Can't delete entry for free space\n");
		return;
	}
	if (contains_driver(entry)) {
		printf("This program can't install drivers\n");
		if (get_okay("are you sure you want to delete this driver? "
		    "[n/y]: ", 0) != 1) {
			return;
		}
		remove_driver(entry);	/* update block0 if necessary */
	}

	map = entry->the_map;
	base = entry->dpme_pblock_start;
	length = entry->dpme_pblocks;
	address = entry->disk_address;

	delete_entry(entry);
	entry = create_entry(map, address, "" , kFreeType, base, length);
	combine_entry(entry);
	renumber_disk_addresses(entry->the_map);
	entry->the_map->changed = 1;
}


int
contains_driver(struct entry *entry)
{
	struct partition_map *map;
	struct ddmap *m;
	int i;
	uint32_t start;

	map = entry->the_map;
	m = map->sbDDMap;
	for (i = 0; i < map->sbDrvrCount; i++) {
		start = m[i].ddBlock;
		if (entry->dpme_pblock_start <= start &&
		    (start + m[i].ddSize) <= (entry->dpme_pblock_start +
		    entry->dpme_pblocks))
			return 1;
	}

	return 0;
}


void
combine_entry(struct entry *entry)
{
	struct entry *p;
	uint32_t end;

	if (entry == NULL ||
	    strncasecmp(entry->dpme_type, kFreeType, DPISTRLEN) != 0)
		return;

	p = LIST_NEXT(entry, base_entry);
	if (p != NULL) {
		if (strncasecmp(p->dpme_type, kFreeType, DPISTRLEN) !=
		    0) {
			/* next is not free */
		} else if (entry->dpme_pblock_start +
		    entry->dpme_pblocks != p->dpme_pblock_start) {
			/* next is not contiguous (XXX this is bad) */
			printf("next entry is not contiguous\n");
			/* start is already minimum */
			/* new end is maximum of two ends */
			end = p->dpme_pblock_start + p->dpme_pblocks;
			if (end > entry->dpme_pblock_start +
			    entry->dpme_pblocks) {
				entry->dpme_pblocks = end -
				    entry->dpme_pblock_start;
			}
			delete_entry(p);
		} else {
			entry->dpme_pblocks += p->dpme_pblocks;
			delete_entry(p);
		}
	}

	LIST_FOREACH(p, &entry->the_map->base_order, base_entry) {
		if (LIST_NEXT(p, base_entry) == entry)
			break;
	}
	if (p != NULL) {
		if (strncasecmp(p->dpme_type, kFreeType, DPISTRLEN) != 0) {
			/* previous is not free */
		} else if (p->dpme_pblock_start + p->dpme_pblocks !=
		    entry->dpme_pblock_start) {
			/* previous is not contiguous (XXX this is bad) */
			printf("previous entry is not contiguous\n");
			/* new end is maximum of two ends */
			end = p->dpme_pblock_start + p->dpme_pblocks;
			if (end < entry->dpme_pblock_start +
			    entry->dpme_pblocks) {
				end = entry->dpme_pblock_start +
				    entry->dpme_pblocks;
			}
			entry->dpme_pblocks = end - p->dpme_pblock_start;
			entry->dpme_pblock_start = p->dpme_pblock_start;
			delete_entry(p);
		} else {
			entry->dpme_pblock_start = p->dpme_pblock_start;
			entry->dpme_pblocks += p->dpme_pblocks;
			delete_entry(p);
		}
	}
}


void
delete_entry(struct entry *entry)
{
	struct partition_map *map;

	map = entry->the_map;
	map->blocks_in_map--;

	LIST_REMOVE(entry, disk_entry);
	LIST_REMOVE(entry, base_entry);

	free(entry);
}


struct entry *
find_entry_by_disk_address(long ix, struct partition_map *map)
{
	struct entry *cur;

	LIST_FOREACH(cur, &map->disk_order, disk_entry) {
		if (cur->disk_address == ix)
			break;
	}
	return cur;
}


struct entry *
find_entry_by_type(const char *type_name, struct partition_map *map)
{
	struct entry *cur;

	LIST_FOREACH(cur, &map->base_order, base_entry) {
		if (strncasecmp(cur->dpme_type, type_name, DPISTRLEN) == 0)
			break;
	}
	return cur;
}

struct entry *
find_entry_by_base(uint32_t base, struct partition_map *map)
{
	struct entry *cur;

	LIST_FOREACH(cur, &map->base_order, base_entry) {
		if (cur->dpme_pblock_start == base)
			break;
	}
	return cur;
}


void
move_entry_in_map(long index1, long index2, struct partition_map *map)
{
	struct entry *p1, *p2;

	if (index1 == index2)
		return;

	if (index1 == 1 || index2 == 1) {
		printf("Partition #1 cannot be moved\n");
		return;
	}
	p1 = find_entry_by_disk_address(index1, map);
	if (p1 == NULL) {
		printf("Partition #%ld not found\n", index1);
		return;
	}
	p2 = find_entry_by_disk_address(index2, map);
	if (p2 == NULL) {
		printf("Partition #%ld not found\n", index2);
		return;
	}

	LIST_REMOVE(p1, disk_entry);
	LIST_REMOVE(p2, disk_entry);

	p1->disk_address = index2;
	p2->disk_address = index1;

	insert_in_disk_order(p1);
	insert_in_disk_order(p2);

	renumber_disk_addresses(map);
	map->changed = 1;
}


void
insert_in_disk_order(struct entry *entry)
{
	struct partition_map *map;
	struct entry *cur;

	/* find position in disk list & insert */
	map = entry->the_map;
	if (LIST_EMPTY(&map->disk_order)) {
		LIST_INSERT_HEAD(&map->disk_order, entry, disk_entry);
		return;
	}

	LIST_FOREACH(cur, &map->disk_order, disk_entry) {
		if (cur->disk_address >= entry->disk_address) {
			LIST_INSERT_BEFORE(cur, entry, disk_entry);
			return;
		}
		if (LIST_NEXT(cur, disk_entry) == NULL) {
			LIST_INSERT_AFTER(cur, entry, disk_entry);
			return;
		}
	}
}


void
insert_in_base_order(struct entry *entry)
{
	struct partition_map *map;
	struct entry *cur;
	uint32_t start;

	/* find position in base list & insert */
	map = entry->the_map;
	if (LIST_EMPTY(&map->base_order)) {
		LIST_INSERT_HEAD(&map->base_order, entry, base_entry);
		return;
	}

	start = entry->dpme_pblock_start;
	LIST_FOREACH(cur, &map->base_order, base_entry) {
		if (start <= cur->dpme_pblock_start) {
			LIST_INSERT_BEFORE(cur, entry, base_entry);
			return;
		}
		if (LIST_NEXT(cur, base_entry) == NULL) {
			LIST_INSERT_AFTER(cur, entry, base_entry);
			return;
		}
	}
}


void
resize_map(long new_size, struct partition_map *map)
{
	struct entry *entry;
	struct entry *next;
	int incr;

	entry = find_entry_by_type(kMapType, map);

	if (entry == NULL) {
		printf("Couldn't find entry for map!\n");
		return;
	}
	if (new_size == entry->dpme_pblocks)
		return;

	next = LIST_NEXT(entry, base_entry);

	if (new_size < entry->dpme_pblocks) {
		/* make it smaller */
		if (next == NULL ||
		    strncasecmp(next->dpme_type, kFreeType, DPISTRLEN) != 0)
			incr = 1;
		else
			incr = 0;
		if (new_size < map->blocks_in_map + incr) {
			printf("New size would be too small\n");
			return;
		}
		goto doit;
	}
	/* make it larger */
	if (next == NULL ||
	    strncasecmp(next->dpme_type, kFreeType, DPISTRLEN) != 0) {
		printf("No free space to expand into\n");
		return;
	}
	if (entry->dpme_pblock_start + entry->dpme_pblocks
	    != next->dpme_pblock_start) {
		printf("No contiguous free space to expand into\n");
		return;
	}
	if (new_size > entry->dpme_pblocks + next->dpme_pblocks) {
		printf("No enough free space\n");
		return;
	}
doit:
	entry->dpme_type[0] = 0;
	delete_partition_from_map(entry);
	add_partition_to_map("Apple", kMapType, 1, new_size, map);
	map->maximum_in_map = new_size;
}


void
remove_driver(struct entry *entry)
{
	struct partition_map *map;
	struct ddmap *m;
	int i, j;
	uint32_t start;

	/*
	 * compute the factor to convert the block numbers in block0
	 * into partition map block numbers.
	 */
	map = entry->the_map;
	m = map->sbDDMap;
	for (i = 0; i < map->sbDrvrCount; i++) {
		start = m[i].ddBlock;
		/*
		 * zap the driver if it is wholly contained in the
		 * partition
		 */
		if (entry->dpme_pblock_start <= start && (start +
		    m[i].ddSize) <= (entry->dpme_pblock_start +
		    entry->dpme_pblocks)) {
			/*
			 * Delete this driver by copying down later ones and
			 * zapping the last one.
			 */
			for (j = i + 1; j < map->sbDrvrCount; j++, i++) {
				m[i].ddBlock = m[i].ddBlock;
				m[i].ddSize = m[j].ddSize;
				m[i].ddType = m[j].ddType;
			}
			m[i].ddBlock = 0;
			m[i].ddSize = 0;
			m[i].ddType = 0;
			map->sbDrvrCount -= 1;
			return;	/* XXX if we continue we will delete
				 * other drivers? */
		}
	}
}