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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * ldm - Support for Windows Logical Disk Manager (Dynamic Disks)
   4 *
   5 * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
   6 * Copyright (c) 2001-2012 Anton Altaparmakov
   7 * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
   8 *
   9 * Documentation is available at http://www.linux-ntfs.org/doku.php?id=downloads 
  10 */
  11
  12#include <linux/slab.h>
  13#include <linux/pagemap.h>
  14#include <linux/stringify.h>
  15#include <linux/kernel.h>
  16#include <linux/uuid.h>
  17#include <linux/msdos_partition.h>
  18
  19#include "ldm.h"
  20#include "check.h"
  21
  22/*
  23 * ldm_debug/info/error/crit - Output an error message
  24 * @f:    A printf format string containing the message
  25 * @...:  Variables to substitute into @f
  26 *
  27 * ldm_debug() writes a DEBUG level message to the syslog but only if the
  28 * driver was compiled with debug enabled. Otherwise, the call turns into a NOP.
  29 */
  30#ifndef CONFIG_LDM_DEBUG
  31#define ldm_debug(...)	do {} while (0)
  32#else
  33#define ldm_debug(f, a...) _ldm_printk (KERN_DEBUG, __func__, f, ##a)
  34#endif
  35
  36#define ldm_crit(f, a...)  _ldm_printk (KERN_CRIT,  __func__, f, ##a)
  37#define ldm_error(f, a...) _ldm_printk (KERN_ERR,   __func__, f, ##a)
  38#define ldm_info(f, a...)  _ldm_printk (KERN_INFO,  __func__, f, ##a)
  39
  40static __printf(3, 4)
  41void _ldm_printk(const char *level, const char *function, const char *fmt, ...)
  42{
  43	struct va_format vaf;
  44	va_list args;
  45
  46	va_start (args, fmt);
  47
  48	vaf.fmt = fmt;
  49	vaf.va = &args;
  50
  51	printk("%s%s(): %pV\n", level, function, &vaf);
  52
  53	va_end(args);
  54}
  55
  56/**
  57 * ldm_parse_privhead - Read the LDM Database PRIVHEAD structure
  58 * @data:  Raw database PRIVHEAD structure loaded from the device
  59 * @ph:    In-memory privhead structure in which to return parsed information
  60 *
  61 * This parses the LDM database PRIVHEAD structure supplied in @data and
  62 * sets up the in-memory privhead structure @ph with the obtained information.
  63 *
  64 * Return:  'true'   @ph contains the PRIVHEAD data
  65 *          'false'  @ph contents are undefined
  66 */
  67static bool ldm_parse_privhead(const u8 *data, struct privhead *ph)
  68{
  69	bool is_vista = false;
  70
  71	BUG_ON(!data || !ph);
  72	if (MAGIC_PRIVHEAD != get_unaligned_be64(data)) {
  73		ldm_error("Cannot find PRIVHEAD structure. LDM database is"
  74			" corrupt. Aborting.");
  75		return false;
  76	}
  77	ph->ver_major = get_unaligned_be16(data + 0x000C);
  78	ph->ver_minor = get_unaligned_be16(data + 0x000E);
  79	ph->logical_disk_start = get_unaligned_be64(data + 0x011B);
  80	ph->logical_disk_size = get_unaligned_be64(data + 0x0123);
  81	ph->config_start = get_unaligned_be64(data + 0x012B);
  82	ph->config_size = get_unaligned_be64(data + 0x0133);
  83	/* Version 2.11 is Win2k/XP and version 2.12 is Vista. */
  84	if (ph->ver_major == 2 && ph->ver_minor == 12)
  85		is_vista = true;
  86	if (!is_vista && (ph->ver_major != 2 || ph->ver_minor != 11)) {
  87		ldm_error("Expected PRIVHEAD version 2.11 or 2.12, got %d.%d."
  88			" Aborting.", ph->ver_major, ph->ver_minor);
  89		return false;
  90	}
  91	ldm_debug("PRIVHEAD version %d.%d (Windows %s).", ph->ver_major,
  92			ph->ver_minor, is_vista ? "Vista" : "2000/XP");
  93	if (ph->config_size != LDM_DB_SIZE) {	/* 1 MiB in sectors. */
  94		/* Warn the user and continue, carefully. */
  95		ldm_info("Database is normally %u bytes, it claims to "
  96			"be %llu bytes.", LDM_DB_SIZE,
  97			(unsigned long long)ph->config_size);
  98	}
  99	if ((ph->logical_disk_size == 0) || (ph->logical_disk_start +
 100			ph->logical_disk_size > ph->config_start)) {
 101		ldm_error("PRIVHEAD disk size doesn't match real disk size");
 102		return false;
 103	}
 104	if (uuid_parse(data + 0x0030, &ph->disk_id)) {
 105		ldm_error("PRIVHEAD contains an invalid GUID.");
 106		return false;
 107	}
 108	ldm_debug("Parsed PRIVHEAD successfully.");
 109	return true;
 110}
 111
 112/**
 113 * ldm_parse_tocblock - Read the LDM Database TOCBLOCK structure
 114 * @data:  Raw database TOCBLOCK structure loaded from the device
 115 * @toc:   In-memory toc structure in which to return parsed information
 116 *
 117 * This parses the LDM Database TOCBLOCK (table of contents) structure supplied
 118 * in @data and sets up the in-memory tocblock structure @toc with the obtained
 119 * information.
 120 *
 121 * N.B.  The *_start and *_size values returned in @toc are not range-checked.
 122 *
 123 * Return:  'true'   @toc contains the TOCBLOCK data
 124 *          'false'  @toc contents are undefined
 125 */
 126static bool ldm_parse_tocblock (const u8 *data, struct tocblock *toc)
 127{
 128	BUG_ON (!data || !toc);
 129
 130	if (MAGIC_TOCBLOCK != get_unaligned_be64(data)) {
 131		ldm_crit ("Cannot find TOCBLOCK, database may be corrupt.");
 132		return false;
 133	}
 134	strscpy_pad(toc->bitmap1_name, data + 0x24, sizeof(toc->bitmap1_name));
 135	toc->bitmap1_start = get_unaligned_be64(data + 0x2E);
 136	toc->bitmap1_size  = get_unaligned_be64(data + 0x36);
 137
 138	if (strncmp (toc->bitmap1_name, TOC_BITMAP1,
 139			sizeof (toc->bitmap1_name)) != 0) {
 140		ldm_crit ("TOCBLOCK's first bitmap is '%s', should be '%s'.",
 141				TOC_BITMAP1, toc->bitmap1_name);
 142		return false;
 143	}
 144	strscpy_pad(toc->bitmap2_name, data + 0x46, sizeof(toc->bitmap2_name));
 145	toc->bitmap2_start = get_unaligned_be64(data + 0x50);
 146	toc->bitmap2_size  = get_unaligned_be64(data + 0x58);
 147	if (strncmp (toc->bitmap2_name, TOC_BITMAP2,
 148			sizeof (toc->bitmap2_name)) != 0) {
 149		ldm_crit ("TOCBLOCK's second bitmap is '%s', should be '%s'.",
 150				TOC_BITMAP2, toc->bitmap2_name);
 151		return false;
 152	}
 153	ldm_debug ("Parsed TOCBLOCK successfully.");
 154	return true;
 155}
 156
 157/**
 158 * ldm_parse_vmdb - Read the LDM Database VMDB structure
 159 * @data:  Raw database VMDB structure loaded from the device
 160 * @vm:    In-memory vmdb structure in which to return parsed information
 161 *
 162 * This parses the LDM Database VMDB structure supplied in @data and sets up
 163 * the in-memory vmdb structure @vm with the obtained information.
 164 *
 165 * N.B.  The *_start, *_size and *_seq values will be range-checked later.
 166 *
 167 * Return:  'true'   @vm contains VMDB info
 168 *          'false'  @vm contents are undefined
 169 */
 170static bool ldm_parse_vmdb (const u8 *data, struct vmdb *vm)
 171{
 172	BUG_ON (!data || !vm);
 173
 174	if (MAGIC_VMDB != get_unaligned_be32(data)) {
 175		ldm_crit ("Cannot find the VMDB, database may be corrupt.");
 176		return false;
 177	}
 178
 179	vm->ver_major = get_unaligned_be16(data + 0x12);
 180	vm->ver_minor = get_unaligned_be16(data + 0x14);
 181	if ((vm->ver_major != 4) || (vm->ver_minor != 10)) {
 182		ldm_error ("Expected VMDB version %d.%d, got %d.%d. "
 183			"Aborting.", 4, 10, vm->ver_major, vm->ver_minor);
 184		return false;
 185	}
 186
 187	vm->vblk_size     = get_unaligned_be32(data + 0x08);
 188	if (vm->vblk_size == 0) {
 189		ldm_error ("Illegal VBLK size");
 190		return false;
 191	}
 192
 193	vm->vblk_offset   = get_unaligned_be32(data + 0x0C);
 194	vm->last_vblk_seq = get_unaligned_be32(data + 0x04);
 195
 196	ldm_debug ("Parsed VMDB successfully.");
 197	return true;
 198}
 199
 200/**
 201 * ldm_compare_privheads - Compare two privhead objects
 202 * @ph1:  First privhead
 203 * @ph2:  Second privhead
 204 *
 205 * This compares the two privhead structures @ph1 and @ph2.
 206 *
 207 * Return:  'true'   Identical
 208 *          'false'  Different
 209 */
 210static bool ldm_compare_privheads (const struct privhead *ph1,
 211				   const struct privhead *ph2)
 212{
 213	BUG_ON (!ph1 || !ph2);
 214
 215	return ((ph1->ver_major          == ph2->ver_major)		&&
 216		(ph1->ver_minor          == ph2->ver_minor)		&&
 217		(ph1->logical_disk_start == ph2->logical_disk_start)	&&
 218		(ph1->logical_disk_size  == ph2->logical_disk_size)	&&
 219		(ph1->config_start       == ph2->config_start)		&&
 220		(ph1->config_size        == ph2->config_size)		&&
 221		uuid_equal(&ph1->disk_id, &ph2->disk_id));
 222}
 223
 224/**
 225 * ldm_compare_tocblocks - Compare two tocblock objects
 226 * @toc1:  First toc
 227 * @toc2:  Second toc
 228 *
 229 * This compares the two tocblock structures @toc1 and @toc2.
 230 *
 231 * Return:  'true'   Identical
 232 *          'false'  Different
 233 */
 234static bool ldm_compare_tocblocks (const struct tocblock *toc1,
 235				   const struct tocblock *toc2)
 236{
 237	BUG_ON (!toc1 || !toc2);
 238
 239	return ((toc1->bitmap1_start == toc2->bitmap1_start)	&&
 240		(toc1->bitmap1_size  == toc2->bitmap1_size)	&&
 241		(toc1->bitmap2_start == toc2->bitmap2_start)	&&
 242		(toc1->bitmap2_size  == toc2->bitmap2_size)	&&
 243		!strncmp (toc1->bitmap1_name, toc2->bitmap1_name,
 244			sizeof (toc1->bitmap1_name))		&&
 245		!strncmp (toc1->bitmap2_name, toc2->bitmap2_name,
 246			sizeof (toc1->bitmap2_name)));
 247}
 248
 249/**
 250 * ldm_validate_privheads - Compare the primary privhead with its backups
 251 * @state: Partition check state including device holding the LDM Database
 252 * @ph1:   Memory struct to fill with ph contents
 253 *
 254 * Read and compare all three privheads from disk.
 255 *
 256 * The privheads on disk show the size and location of the main disk area and
 257 * the configuration area (the database).  The values are range-checked against
 258 * @hd, which contains the real size of the disk.
 259 *
 260 * Return:  'true'   Success
 261 *          'false'  Error
 262 */
 263static bool ldm_validate_privheads(struct parsed_partitions *state,
 264				   struct privhead *ph1)
 265{
 266	static const int off[3] = { OFF_PRIV1, OFF_PRIV2, OFF_PRIV3 };
 267	struct privhead *ph[3] = { ph1 };
 268	Sector sect;
 269	u8 *data;
 270	bool result = false;
 271	long num_sects;
 272	int i;
 273
 274	BUG_ON (!state || !ph1);
 275
 276	ph[1] = kmalloc (sizeof (*ph[1]), GFP_KERNEL);
 277	ph[2] = kmalloc (sizeof (*ph[2]), GFP_KERNEL);
 278	if (!ph[1] || !ph[2]) {
 279		ldm_crit ("Out of memory.");
 280		goto out;
 281	}
 282
 283	/* off[1 & 2] are relative to ph[0]->config_start */
 284	ph[0]->config_start = 0;
 285
 286	/* Read and parse privheads */
 287	for (i = 0; i < 3; i++) {
 288		data = read_part_sector(state, ph[0]->config_start + off[i],
 289					&sect);
 290		if (!data) {
 291			ldm_crit ("Disk read failed.");
 292			goto out;
 293		}
 294		result = ldm_parse_privhead (data, ph[i]);
 295		put_dev_sector (sect);
 296		if (!result) {
 297			ldm_error ("Cannot find PRIVHEAD %d.", i+1); /* Log again */
 298			if (i < 2)
 299				goto out;	/* Already logged */
 300			else
 301				break;	/* FIXME ignore for now, 3rd PH can fail on odd-sized disks */
 302		}
 303	}
 304
 305	num_sects = get_capacity(state->disk);
 306
 307	if ((ph[0]->config_start > num_sects) ||
 308	   ((ph[0]->config_start + ph[0]->config_size) > num_sects)) {
 309		ldm_crit ("Database extends beyond the end of the disk.");
 310		goto out;
 311	}
 312
 313	if ((ph[0]->logical_disk_start > ph[0]->config_start) ||
 314	   ((ph[0]->logical_disk_start + ph[0]->logical_disk_size)
 315		    > ph[0]->config_start)) {
 316		ldm_crit ("Disk and database overlap.");
 317		goto out;
 318	}
 319
 320	if (!ldm_compare_privheads (ph[0], ph[1])) {
 321		ldm_crit ("Primary and backup PRIVHEADs don't match.");
 322		goto out;
 323	}
 324	/* FIXME ignore this for now
 325	if (!ldm_compare_privheads (ph[0], ph[2])) {
 326		ldm_crit ("Primary and backup PRIVHEADs don't match.");
 327		goto out;
 328	}*/
 329	ldm_debug ("Validated PRIVHEADs successfully.");
 330	result = true;
 331out:
 332	kfree (ph[1]);
 333	kfree (ph[2]);
 334	return result;
 335}
 336
 337/**
 338 * ldm_validate_tocblocks - Validate the table of contents and its backups
 339 * @state: Partition check state including device holding the LDM Database
 340 * @base:  Offset, into @state->disk, of the database
 341 * @ldb:   Cache of the database structures
 342 *
 343 * Find and compare the four tables of contents of the LDM Database stored on
 344 * @state->disk and return the parsed information into @toc1.
 345 *
 346 * The offsets and sizes of the configs are range-checked against a privhead.
 347 *
 348 * Return:  'true'   @toc1 contains validated TOCBLOCK info
 349 *          'false'  @toc1 contents are undefined
 350 */
 351static bool ldm_validate_tocblocks(struct parsed_partitions *state,
 352				   unsigned long base, struct ldmdb *ldb)
 353{
 354	static const int off[4] = { OFF_TOCB1, OFF_TOCB2, OFF_TOCB3, OFF_TOCB4};
 355	struct tocblock *tb[4];
 356	struct privhead *ph;
 357	Sector sect;
 358	u8 *data;
 359	int i, nr_tbs;
 360	bool result = false;
 361
 362	BUG_ON(!state || !ldb);
 363	ph = &ldb->ph;
 364	tb[0] = &ldb->toc;
 365	tb[1] = kmalloc_array(3, sizeof(*tb[1]), GFP_KERNEL);
 366	if (!tb[1]) {
 367		ldm_crit("Out of memory.");
 368		goto err;
 369	}
 370	tb[2] = (struct tocblock*)((u8*)tb[1] + sizeof(*tb[1]));
 371	tb[3] = (struct tocblock*)((u8*)tb[2] + sizeof(*tb[2]));
 372	/*
 373	 * Try to read and parse all four TOCBLOCKs.
 374	 *
 375	 * Windows Vista LDM v2.12 does not always have all four TOCBLOCKs so
 376	 * skip any that fail as long as we get at least one valid TOCBLOCK.
 377	 */
 378	for (nr_tbs = i = 0; i < 4; i++) {
 379		data = read_part_sector(state, base + off[i], &sect);
 380		if (!data) {
 381			ldm_error("Disk read failed for TOCBLOCK %d.", i);
 382			continue;
 383		}
 384		if (ldm_parse_tocblock(data, tb[nr_tbs]))
 385			nr_tbs++;
 386		put_dev_sector(sect);
 387	}
 388	if (!nr_tbs) {
 389		ldm_crit("Failed to find a valid TOCBLOCK.");
 390		goto err;
 391	}
 392	/* Range check the TOCBLOCK against a privhead. */
 393	if (((tb[0]->bitmap1_start + tb[0]->bitmap1_size) > ph->config_size) ||
 394			((tb[0]->bitmap2_start + tb[0]->bitmap2_size) >
 395			ph->config_size)) {
 396		ldm_crit("The bitmaps are out of range.  Giving up.");
 397		goto err;
 398	}
 399	/* Compare all loaded TOCBLOCKs. */
 400	for (i = 1; i < nr_tbs; i++) {
 401		if (!ldm_compare_tocblocks(tb[0], tb[i])) {
 402			ldm_crit("TOCBLOCKs 0 and %d do not match.", i);
 403			goto err;
 404		}
 405	}
 406	ldm_debug("Validated %d TOCBLOCKs successfully.", nr_tbs);
 407	result = true;
 408err:
 409	kfree(tb[1]);
 410	return result;
 411}
 412
 413/**
 414 * ldm_validate_vmdb - Read the VMDB and validate it
 415 * @state: Partition check state including device holding the LDM Database
 416 * @base:  Offset, into @bdev, of the database
 417 * @ldb:   Cache of the database structures
 418 *
 419 * Find the vmdb of the LDM Database stored on @bdev and return the parsed
 420 * information in @ldb.
 421 *
 422 * Return:  'true'   @ldb contains validated VBDB info
 423 *          'false'  @ldb contents are undefined
 424 */
 425static bool ldm_validate_vmdb(struct parsed_partitions *state,
 426			      unsigned long base, struct ldmdb *ldb)
 427{
 428	Sector sect;
 429	u8 *data;
 430	bool result = false;
 431	struct vmdb *vm;
 432	struct tocblock *toc;
 433
 434	BUG_ON (!state || !ldb);
 435
 436	vm  = &ldb->vm;
 437	toc = &ldb->toc;
 438
 439	data = read_part_sector(state, base + OFF_VMDB, &sect);
 440	if (!data) {
 441		ldm_crit ("Disk read failed.");
 442		return false;
 443	}
 444
 445	if (!ldm_parse_vmdb (data, vm))
 446		goto out;				/* Already logged */
 447
 448	/* Are there uncommitted transactions? */
 449	if (get_unaligned_be16(data + 0x10) != 0x01) {
 450		ldm_crit ("Database is not in a consistent state.  Aborting.");
 451		goto out;
 452	}
 453
 454	if (vm->vblk_offset != 512)
 455		ldm_info ("VBLKs start at offset 0x%04x.", vm->vblk_offset);
 456
 457	/*
 458	 * The last_vblkd_seq can be before the end of the vmdb, just make sure
 459	 * it is not out of bounds.
 460	 */
 461	if ((vm->vblk_size * vm->last_vblk_seq) > (toc->bitmap1_size << 9)) {
 462		ldm_crit ("VMDB exceeds allowed size specified by TOCBLOCK.  "
 463				"Database is corrupt.  Aborting.");
 464		goto out;
 465	}
 466
 467	result = true;
 468out:
 469	put_dev_sector (sect);
 470	return result;
 471}
 472
 473
 474/**
 475 * ldm_validate_partition_table - Determine whether bdev might be a dynamic disk
 476 * @state: Partition check state including device holding the LDM Database
 477 *
 478 * This function provides a weak test to decide whether the device is a dynamic
 479 * disk or not.  It looks for an MS-DOS-style partition table containing at
 480 * least one partition of type 0x42 (formerly SFS, now used by Windows for
 481 * dynamic disks).
 482 *
 483 * N.B.  The only possible error can come from the read_part_sector and that is
 484 *       only likely to happen if the underlying device is strange.  If that IS
 485 *       the case we should return zero to let someone else try.
 486 *
 487 * Return:  'true'   @state->disk is a dynamic disk
 488 *          'false'  @state->disk is not a dynamic disk, or an error occurred
 489 */
 490static bool ldm_validate_partition_table(struct parsed_partitions *state)
 491{
 492	Sector sect;
 493	u8 *data;
 494	struct msdos_partition *p;
 495	int i;
 496	bool result = false;
 497
 498	BUG_ON(!state);
 499
 500	data = read_part_sector(state, 0, &sect);
 501	if (!data) {
 502		ldm_info ("Disk read failed.");
 503		return false;
 504	}
 505
 506	if (*(__le16*) (data + 0x01FE) != cpu_to_le16 (MSDOS_LABEL_MAGIC))
 507		goto out;
 508
 509	p = (struct msdos_partition *)(data + 0x01BE);
 510	for (i = 0; i < 4; i++, p++)
 511		if (p->sys_ind == LDM_PARTITION) {
 512			result = true;
 513			break;
 514		}
 515
 516	if (result)
 517		ldm_debug ("Found W2K dynamic disk partition type.");
 518
 519out:
 520	put_dev_sector (sect);
 521	return result;
 522}
 523
 524/**
 525 * ldm_get_disk_objid - Search a linked list of vblk's for a given Disk Id
 526 * @ldb:  Cache of the database structures
 527 *
 528 * The LDM Database contains a list of all partitions on all dynamic disks.
 529 * The primary PRIVHEAD, at the beginning of the physical disk, tells us
 530 * the GUID of this disk.  This function searches for the GUID in a linked
 531 * list of vblk's.
 532 *
 533 * Return:  Pointer, A matching vblk was found
 534 *          NULL,    No match, or an error
 535 */
 536static struct vblk * ldm_get_disk_objid (const struct ldmdb *ldb)
 537{
 538	struct list_head *item;
 539
 540	BUG_ON (!ldb);
 541
 542	list_for_each (item, &ldb->v_disk) {
 543		struct vblk *v = list_entry (item, struct vblk, list);
 544		if (uuid_equal(&v->vblk.disk.disk_id, &ldb->ph.disk_id))
 545			return v;
 546	}
 547
 548	return NULL;
 549}
 550
 551/**
 552 * ldm_create_data_partitions - Create data partitions for this device
 553 * @pp:   List of the partitions parsed so far
 554 * @ldb:  Cache of the database structures
 555 *
 556 * The database contains ALL the partitions for ALL disk groups, so we need to
 557 * filter out this specific disk. Using the disk's object id, we can find all
 558 * the partitions in the database that belong to this disk.
 559 *
 560 * Add each partition in our database, to the parsed_partitions structure.
 561 *
 562 * N.B.  This function creates the partitions in the order it finds partition
 563 *       objects in the linked list.
 564 *
 565 * Return:  'true'   Partition created
 566 *          'false'  Error, probably a range checking problem
 567 */
 568static bool ldm_create_data_partitions (struct parsed_partitions *pp,
 569					const struct ldmdb *ldb)
 570{
 571	struct list_head *item;
 572	struct vblk *vb;
 573	struct vblk *disk;
 574	struct vblk_part *part;
 575	int part_num = 1;
 576
 577	BUG_ON (!pp || !ldb);
 578
 579	disk = ldm_get_disk_objid (ldb);
 580	if (!disk) {
 581		ldm_crit ("Can't find the ID of this disk in the database.");
 582		return false;
 583	}
 584
 585	strlcat(pp->pp_buf, " [LDM]", PAGE_SIZE);
 586
 587	/* Create the data partitions */
 588	list_for_each (item, &ldb->v_part) {
 589		vb = list_entry (item, struct vblk, list);
 590		part = &vb->vblk.part;
 591
 592		if (part->disk_id != disk->obj_id)
 593			continue;
 594
 595		put_partition (pp, part_num, ldb->ph.logical_disk_start +
 596				part->start, part->size);
 597		part_num++;
 598	}
 599
 600	strlcat(pp->pp_buf, "\n", PAGE_SIZE);
 601	return true;
 602}
 603
 604
 605/**
 606 * ldm_relative - Calculate the next relative offset
 607 * @buffer:  Block of data being worked on
 608 * @buflen:  Size of the block of data
 609 * @base:    Size of the previous fixed width fields
 610 * @offset:  Cumulative size of the previous variable-width fields
 611 *
 612 * Because many of the VBLK fields are variable-width, it's necessary
 613 * to calculate each offset based on the previous one and the length
 614 * of the field it pointed to.
 615 *
 616 * Return:  -1 Error, the calculated offset exceeded the size of the buffer
 617 *           n OK, a range-checked offset into buffer
 618 */
 619static int ldm_relative(const u8 *buffer, int buflen, int base, int offset)
 620{
 621
 622	base += offset;
 623	if (!buffer || offset < 0 || base > buflen) {
 624		if (!buffer)
 625			ldm_error("!buffer");
 626		if (offset < 0)
 627			ldm_error("offset (%d) < 0", offset);
 628		if (base > buflen)
 629			ldm_error("base (%d) > buflen (%d)", base, buflen);
 630		return -1;
 631	}
 632	if (base + buffer[base] >= buflen) {
 633		ldm_error("base (%d) + buffer[base] (%d) >= buflen (%d)", base,
 634				buffer[base], buflen);
 635		return -1;
 636	}
 637	return buffer[base] + offset + 1;
 638}
 639
 640/**
 641 * ldm_get_vnum - Convert a variable-width, big endian number, into cpu order
 642 * @block:  Pointer to the variable-width number to convert
 643 *
 644 * Large numbers in the LDM Database are often stored in a packed format.  Each
 645 * number is prefixed by a one byte width marker.  All numbers in the database
 646 * are stored in big-endian byte order.  This function reads one of these
 647 * numbers and returns the result
 648 *
 649 * N.B.  This function DOES NOT perform any range checking, though the most
 650 *       it will read is eight bytes.
 651 *
 652 * Return:  n A number
 653 *          0 Zero, or an error occurred
 654 */
 655static u64 ldm_get_vnum (const u8 *block)
 656{
 657	u64 tmp = 0;
 658	u8 length;
 659
 660	BUG_ON (!block);
 661
 662	length = *block++;
 663
 664	if (length && length <= 8)
 665		while (length--)
 666			tmp = (tmp << 8) | *block++;
 667	else
 668		ldm_error ("Illegal length %d.", length);
 669
 670	return tmp;
 671}
 672
 673/**
 674 * ldm_get_vstr - Read a length-prefixed string into a buffer
 675 * @block:   Pointer to the length marker
 676 * @buffer:  Location to copy string to
 677 * @buflen:  Size of the output buffer
 678 *
 679 * Many of the strings in the LDM Database are not NULL terminated.  Instead
 680 * they are prefixed by a one byte length marker.  This function copies one of
 681 * these strings into a buffer.
 682 *
 683 * N.B.  This function DOES NOT perform any range checking on the input.
 684 *       If the buffer is too small, the output will be truncated.
 685 *
 686 * Return:  0, Error and @buffer contents are undefined
 687 *          n, String length in characters (excluding NULL)
 688 *          buflen-1, String was truncated.
 689 */
 690static int ldm_get_vstr (const u8 *block, u8 *buffer, int buflen)
 691{
 692	int length;
 693
 694	BUG_ON (!block || !buffer);
 695
 696	length = block[0];
 697	if (length >= buflen) {
 698		ldm_error ("Truncating string %d -> %d.", length, buflen);
 699		length = buflen - 1;
 700	}
 701	memcpy (buffer, block + 1, length);
 702	buffer[length] = 0;
 703	return length;
 704}
 705
 706
 707/**
 708 * ldm_parse_cmp3 - Read a raw VBLK Component object into a vblk structure
 709 * @buffer:  Block of data being worked on
 710 * @buflen:  Size of the block of data
 711 * @vb:      In-memory vblk in which to return information
 712 *
 713 * Read a raw VBLK Component object (version 3) into a vblk structure.
 714 *
 715 * Return:  'true'   @vb contains a Component VBLK
 716 *          'false'  @vb contents are not defined
 717 */
 718static bool ldm_parse_cmp3 (const u8 *buffer, int buflen, struct vblk *vb)
 719{
 720	int r_objid, r_name, r_vstate, r_child, r_parent, r_stripe, r_cols, len;
 721	struct vblk_comp *comp;
 722
 723	BUG_ON (!buffer || !vb);
 724
 725	r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
 726	r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
 727	r_vstate = ldm_relative (buffer, buflen, 0x18, r_name);
 728	r_child  = ldm_relative (buffer, buflen, 0x1D, r_vstate);
 729	r_parent = ldm_relative (buffer, buflen, 0x2D, r_child);
 730
 731	if (buffer[0x12] & VBLK_FLAG_COMP_STRIPE) {
 732		r_stripe = ldm_relative (buffer, buflen, 0x2E, r_parent);
 733		r_cols   = ldm_relative (buffer, buflen, 0x2E, r_stripe);
 734		len = r_cols;
 735	} else {
 736		r_stripe = 0;
 737		len = r_parent;
 738	}
 739	if (len < 0)
 740		return false;
 741
 742	len += VBLK_SIZE_CMP3;
 743	if (len != get_unaligned_be32(buffer + 0x14))
 744		return false;
 745
 746	comp = &vb->vblk.comp;
 747	ldm_get_vstr (buffer + 0x18 + r_name, comp->state,
 748		sizeof (comp->state));
 749	comp->type      = buffer[0x18 + r_vstate];
 750	comp->children  = ldm_get_vnum (buffer + 0x1D + r_vstate);
 751	comp->parent_id = ldm_get_vnum (buffer + 0x2D + r_child);
 752	comp->chunksize = r_stripe ? ldm_get_vnum (buffer+r_parent+0x2E) : 0;
 753
 754	return true;
 755}
 756
 757/**
 758 * ldm_parse_dgr3 - Read a raw VBLK Disk Group object into a vblk structure
 759 * @buffer:  Block of data being worked on
 760 * @buflen:  Size of the block of data
 761 * @vb:      In-memory vblk in which to return information
 762 *
 763 * Read a raw VBLK Disk Group object (version 3) into a vblk structure.
 764 *
 765 * Return:  'true'   @vb contains a Disk Group VBLK
 766 *          'false'  @vb contents are not defined
 767 */
 768static int ldm_parse_dgr3 (const u8 *buffer, int buflen, struct vblk *vb)
 769{
 770	int r_objid, r_name, r_diskid, r_id1, r_id2, len;
 771	struct vblk_dgrp *dgrp;
 772
 773	BUG_ON (!buffer || !vb);
 774
 775	r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
 776	r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
 777	r_diskid = ldm_relative (buffer, buflen, 0x18, r_name);
 778
 779	if (buffer[0x12] & VBLK_FLAG_DGR3_IDS) {
 780		r_id1 = ldm_relative (buffer, buflen, 0x24, r_diskid);
 781		r_id2 = ldm_relative (buffer, buflen, 0x24, r_id1);
 782		len = r_id2;
 783	} else
 784		len = r_diskid;
 785	if (len < 0)
 786		return false;
 787
 788	len += VBLK_SIZE_DGR3;
 789	if (len != get_unaligned_be32(buffer + 0x14))
 790		return false;
 791
 792	dgrp = &vb->vblk.dgrp;
 793	ldm_get_vstr (buffer + 0x18 + r_name, dgrp->disk_id,
 794		sizeof (dgrp->disk_id));
 795	return true;
 796}
 797
 798/**
 799 * ldm_parse_dgr4 - Read a raw VBLK Disk Group object into a vblk structure
 800 * @buffer:  Block of data being worked on
 801 * @buflen:  Size of the block of data
 802 * @vb:      In-memory vblk in which to return information
 803 *
 804 * Read a raw VBLK Disk Group object (version 4) into a vblk structure.
 805 *
 806 * Return:  'true'   @vb contains a Disk Group VBLK
 807 *          'false'  @vb contents are not defined
 808 */
 809static bool ldm_parse_dgr4 (const u8 *buffer, int buflen, struct vblk *vb)
 810{
 811	char buf[64];
 812	int r_objid, r_name, r_id1, r_id2, len;
 813
 814	BUG_ON (!buffer || !vb);
 815
 816	r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
 817	r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
 818
 819	if (buffer[0x12] & VBLK_FLAG_DGR4_IDS) {
 820		r_id1 = ldm_relative (buffer, buflen, 0x44, r_name);
 821		r_id2 = ldm_relative (buffer, buflen, 0x44, r_id1);
 822		len = r_id2;
 823	} else
 824		len = r_name;
 825	if (len < 0)
 826		return false;
 827
 828	len += VBLK_SIZE_DGR4;
 829	if (len != get_unaligned_be32(buffer + 0x14))
 830		return false;
 831
 832	ldm_get_vstr (buffer + 0x18 + r_objid, buf, sizeof (buf));
 833	return true;
 834}
 835
 836/**
 837 * ldm_parse_dsk3 - Read a raw VBLK Disk object into a vblk structure
 838 * @buffer:  Block of data being worked on
 839 * @buflen:  Size of the block of data
 840 * @vb:      In-memory vblk in which to return information
 841 *
 842 * Read a raw VBLK Disk object (version 3) into a vblk structure.
 843 *
 844 * Return:  'true'   @vb contains a Disk VBLK
 845 *          'false'  @vb contents are not defined
 846 */
 847static bool ldm_parse_dsk3 (const u8 *buffer, int buflen, struct vblk *vb)
 848{
 849	int r_objid, r_name, r_diskid, r_altname, len;
 850	struct vblk_disk *disk;
 851
 852	BUG_ON (!buffer || !vb);
 853
 854	r_objid   = ldm_relative (buffer, buflen, 0x18, 0);
 855	r_name    = ldm_relative (buffer, buflen, 0x18, r_objid);
 856	r_diskid  = ldm_relative (buffer, buflen, 0x18, r_name);
 857	r_altname = ldm_relative (buffer, buflen, 0x18, r_diskid);
 858	len = r_altname;
 859	if (len < 0)
 860		return false;
 861
 862	len += VBLK_SIZE_DSK3;
 863	if (len != get_unaligned_be32(buffer + 0x14))
 864		return false;
 865
 866	disk = &vb->vblk.disk;
 867	ldm_get_vstr (buffer + 0x18 + r_diskid, disk->alt_name,
 868		sizeof (disk->alt_name));
 869	if (uuid_parse(buffer + 0x19 + r_name, &disk->disk_id))
 870		return false;
 871
 872	return true;
 873}
 874
 875/**
 876 * ldm_parse_dsk4 - Read a raw VBLK Disk object into a vblk structure
 877 * @buffer:  Block of data being worked on
 878 * @buflen:  Size of the block of data
 879 * @vb:      In-memory vblk in which to return information
 880 *
 881 * Read a raw VBLK Disk object (version 4) into a vblk structure.
 882 *
 883 * Return:  'true'   @vb contains a Disk VBLK
 884 *          'false'  @vb contents are not defined
 885 */
 886static bool ldm_parse_dsk4 (const u8 *buffer, int buflen, struct vblk *vb)
 887{
 888	int r_objid, r_name, len;
 889	struct vblk_disk *disk;
 890
 891	BUG_ON (!buffer || !vb);
 892
 893	r_objid = ldm_relative (buffer, buflen, 0x18, 0);
 894	r_name  = ldm_relative (buffer, buflen, 0x18, r_objid);
 895	len     = r_name;
 896	if (len < 0)
 897		return false;
 898
 899	len += VBLK_SIZE_DSK4;
 900	if (len != get_unaligned_be32(buffer + 0x14))
 901		return false;
 902
 903	disk = &vb->vblk.disk;
 904	import_uuid(&disk->disk_id, buffer + 0x18 + r_name);
 905	return true;
 906}
 907
 908/**
 909 * ldm_parse_prt3 - Read a raw VBLK Partition object into a vblk structure
 910 * @buffer:  Block of data being worked on
 911 * @buflen:  Size of the block of data
 912 * @vb:      In-memory vblk in which to return information
 913 *
 914 * Read a raw VBLK Partition object (version 3) into a vblk structure.
 915 *
 916 * Return:  'true'   @vb contains a Partition VBLK
 917 *          'false'  @vb contents are not defined
 918 */
 919static bool ldm_parse_prt3(const u8 *buffer, int buflen, struct vblk *vb)
 920{
 921	int r_objid, r_name, r_size, r_parent, r_diskid, r_index, len;
 922	struct vblk_part *part;
 923
 924	BUG_ON(!buffer || !vb);
 925	r_objid = ldm_relative(buffer, buflen, 0x18, 0);
 926	if (r_objid < 0) {
 927		ldm_error("r_objid %d < 0", r_objid);
 928		return false;
 929	}
 930	r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
 931	if (r_name < 0) {
 932		ldm_error("r_name %d < 0", r_name);
 933		return false;
 934	}
 935	r_size = ldm_relative(buffer, buflen, 0x34, r_name);
 936	if (r_size < 0) {
 937		ldm_error("r_size %d < 0", r_size);
 938		return false;
 939	}
 940	r_parent = ldm_relative(buffer, buflen, 0x34, r_size);
 941	if (r_parent < 0) {
 942		ldm_error("r_parent %d < 0", r_parent);
 943		return false;
 944	}
 945	r_diskid = ldm_relative(buffer, buflen, 0x34, r_parent);
 946	if (r_diskid < 0) {
 947		ldm_error("r_diskid %d < 0", r_diskid);
 948		return false;
 949	}
 950	if (buffer[0x12] & VBLK_FLAG_PART_INDEX) {
 951		r_index = ldm_relative(buffer, buflen, 0x34, r_diskid);
 952		if (r_index < 0) {
 953			ldm_error("r_index %d < 0", r_index);
 954			return false;
 955		}
 956		len = r_index;
 957	} else
 958		len = r_diskid;
 959	if (len < 0) {
 960		ldm_error("len %d < 0", len);
 961		return false;
 962	}
 963	len += VBLK_SIZE_PRT3;
 964	if (len > get_unaligned_be32(buffer + 0x14)) {
 965		ldm_error("len %d > BE32(buffer + 0x14) %d", len,
 966				get_unaligned_be32(buffer + 0x14));
 967		return false;
 968	}
 969	part = &vb->vblk.part;
 970	part->start = get_unaligned_be64(buffer + 0x24 + r_name);
 971	part->volume_offset = get_unaligned_be64(buffer + 0x2C + r_name);
 972	part->size = ldm_get_vnum(buffer + 0x34 + r_name);
 973	part->parent_id = ldm_get_vnum(buffer + 0x34 + r_size);
 974	part->disk_id = ldm_get_vnum(buffer + 0x34 + r_parent);
 975	if (vb->flags & VBLK_FLAG_PART_INDEX)
 976		part->partnum = buffer[0x35 + r_diskid];
 977	else
 978		part->partnum = 0;
 979	return true;
 980}
 981
 982/**
 983 * ldm_parse_vol5 - Read a raw VBLK Volume object into a vblk structure
 984 * @buffer:  Block of data being worked on
 985 * @buflen:  Size of the block of data
 986 * @vb:      In-memory vblk in which to return information
 987 *
 988 * Read a raw VBLK Volume object (version 5) into a vblk structure.
 989 *
 990 * Return:  'true'   @vb contains a Volume VBLK
 991 *          'false'  @vb contents are not defined
 992 */
 993static bool ldm_parse_vol5(const u8 *buffer, int buflen, struct vblk *vb)
 994{
 995	int r_objid, r_name, r_vtype, r_disable_drive_letter, r_child, r_size;
 996	int r_id1, r_id2, r_size2, r_drive, len;
 997	struct vblk_volu *volu;
 998
 999	BUG_ON(!buffer || !vb);
1000	r_objid = ldm_relative(buffer, buflen, 0x18, 0);
1001	if (r_objid < 0) {
1002		ldm_error("r_objid %d < 0", r_objid);
1003		return false;
1004	}
1005	r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
1006	if (r_name < 0) {
1007		ldm_error("r_name %d < 0", r_name);
1008		return false;
1009	}
1010	r_vtype = ldm_relative(buffer, buflen, 0x18, r_name);
1011	if (r_vtype < 0) {
1012		ldm_error("r_vtype %d < 0", r_vtype);
1013		return false;
1014	}
1015	r_disable_drive_letter = ldm_relative(buffer, buflen, 0x18, r_vtype);
1016	if (r_disable_drive_letter < 0) {
1017		ldm_error("r_disable_drive_letter %d < 0",
1018				r_disable_drive_letter);
1019		return false;
1020	}
1021	r_child = ldm_relative(buffer, buflen, 0x2D, r_disable_drive_letter);
1022	if (r_child < 0) {
1023		ldm_error("r_child %d < 0", r_child);
1024		return false;
1025	}
1026	r_size = ldm_relative(buffer, buflen, 0x3D, r_child);
1027	if (r_size < 0) {
1028		ldm_error("r_size %d < 0", r_size);
1029		return false;
1030	}
1031	if (buffer[0x12] & VBLK_FLAG_VOLU_ID1) {
1032		r_id1 = ldm_relative(buffer, buflen, 0x52, r_size);
1033		if (r_id1 < 0) {
1034			ldm_error("r_id1 %d < 0", r_id1);
1035			return false;
1036		}
1037	} else
1038		r_id1 = r_size;
1039	if (buffer[0x12] & VBLK_FLAG_VOLU_ID2) {
1040		r_id2 = ldm_relative(buffer, buflen, 0x52, r_id1);
1041		if (r_id2 < 0) {
1042			ldm_error("r_id2 %d < 0", r_id2);
1043			return false;
1044		}
1045	} else
1046		r_id2 = r_id1;
1047	if (buffer[0x12] & VBLK_FLAG_VOLU_SIZE) {
1048		r_size2 = ldm_relative(buffer, buflen, 0x52, r_id2);
1049		if (r_size2 < 0) {
1050			ldm_error("r_size2 %d < 0", r_size2);
1051			return false;
1052		}
1053	} else
1054		r_size2 = r_id2;
1055	if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
1056		r_drive = ldm_relative(buffer, buflen, 0x52, r_size2);
1057		if (r_drive < 0) {
1058			ldm_error("r_drive %d < 0", r_drive);
1059			return false;
1060		}
1061	} else
1062		r_drive = r_size2;
1063	len = r_drive;
1064	if (len < 0) {
1065		ldm_error("len %d < 0", len);
1066		return false;
1067	}
1068	len += VBLK_SIZE_VOL5;
1069	if (len > get_unaligned_be32(buffer + 0x14)) {
1070		ldm_error("len %d > BE32(buffer + 0x14) %d", len,
1071				get_unaligned_be32(buffer + 0x14));
1072		return false;
1073	}
1074	volu = &vb->vblk.volu;
1075	ldm_get_vstr(buffer + 0x18 + r_name, volu->volume_type,
1076			sizeof(volu->volume_type));
1077	memcpy(volu->volume_state, buffer + 0x18 + r_disable_drive_letter,
1078			sizeof(volu->volume_state));
1079	volu->size = ldm_get_vnum(buffer + 0x3D + r_child);
1080	volu->partition_type = buffer[0x41 + r_size];
1081	memcpy(volu->guid, buffer + 0x42 + r_size, sizeof(volu->guid));
1082	if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
1083		ldm_get_vstr(buffer + 0x52 + r_size, volu->drive_hint,
1084				sizeof(volu->drive_hint));
1085	}
1086	return true;
1087}
1088
1089/**
1090 * ldm_parse_vblk - Read a raw VBLK object into a vblk structure
1091 * @buf:  Block of data being worked on
1092 * @len:  Size of the block of data
1093 * @vb:   In-memory vblk in which to return information
1094 *
1095 * Read a raw VBLK object into a vblk structure.  This function just reads the
1096 * information common to all VBLK types, then delegates the rest of the work to
1097 * helper functions: ldm_parse_*.
1098 *
1099 * Return:  'true'   @vb contains a VBLK
1100 *          'false'  @vb contents are not defined
1101 */
1102static bool ldm_parse_vblk (const u8 *buf, int len, struct vblk *vb)
1103{
1104	bool result = false;
1105	int r_objid;
1106
1107	BUG_ON (!buf || !vb);
1108
1109	r_objid = ldm_relative (buf, len, 0x18, 0);
1110	if (r_objid < 0) {
1111		ldm_error ("VBLK header is corrupt.");
1112		return false;
1113	}
1114
1115	vb->flags  = buf[0x12];
1116	vb->type   = buf[0x13];
1117	vb->obj_id = ldm_get_vnum (buf + 0x18);
1118	ldm_get_vstr (buf+0x18+r_objid, vb->name, sizeof (vb->name));
1119
1120	switch (vb->type) {
1121		case VBLK_CMP3:  result = ldm_parse_cmp3 (buf, len, vb); break;
1122		case VBLK_DSK3:  result = ldm_parse_dsk3 (buf, len, vb); break;
1123		case VBLK_DSK4:  result = ldm_parse_dsk4 (buf, len, vb); break;
1124		case VBLK_DGR3:  result = ldm_parse_dgr3 (buf, len, vb); break;
1125		case VBLK_DGR4:  result = ldm_parse_dgr4 (buf, len, vb); break;
1126		case VBLK_PRT3:  result = ldm_parse_prt3 (buf, len, vb); break;
1127		case VBLK_VOL5:  result = ldm_parse_vol5 (buf, len, vb); break;
1128	}
1129
1130	if (result)
1131		ldm_debug ("Parsed VBLK 0x%llx (type: 0x%02x) ok.",
1132			 (unsigned long long) vb->obj_id, vb->type);
1133	else
1134		ldm_error ("Failed to parse VBLK 0x%llx (type: 0x%02x).",
1135			(unsigned long long) vb->obj_id, vb->type);
1136
1137	return result;
1138}
1139
1140
1141/**
1142 * ldm_ldmdb_add - Adds a raw VBLK entry to the ldmdb database
1143 * @data:  Raw VBLK to add to the database
1144 * @len:   Size of the raw VBLK
1145 * @ldb:   Cache of the database structures
1146 *
1147 * The VBLKs are sorted into categories.  Partitions are also sorted by offset.
1148 *
1149 * N.B.  This function does not check the validity of the VBLKs.
1150 *
1151 * Return:  'true'   The VBLK was added
1152 *          'false'  An error occurred
1153 */
1154static bool ldm_ldmdb_add (u8 *data, int len, struct ldmdb *ldb)
1155{
1156	struct vblk *vb;
1157	struct list_head *item;
1158
1159	BUG_ON (!data || !ldb);
1160
1161	vb = kmalloc (sizeof (*vb), GFP_KERNEL);
1162	if (!vb) {
1163		ldm_crit ("Out of memory.");
1164		return false;
1165	}
1166
1167	if (!ldm_parse_vblk (data, len, vb)) {
1168		kfree(vb);
1169		return false;			/* Already logged */
1170	}
1171
1172	/* Put vblk into the correct list. */
1173	switch (vb->type) {
1174	case VBLK_DGR3:
1175	case VBLK_DGR4:
1176		list_add (&vb->list, &ldb->v_dgrp);
1177		break;
1178	case VBLK_DSK3:
1179	case VBLK_DSK4:
1180		list_add (&vb->list, &ldb->v_disk);
1181		break;
1182	case VBLK_VOL5:
1183		list_add (&vb->list, &ldb->v_volu);
1184		break;
1185	case VBLK_CMP3:
1186		list_add (&vb->list, &ldb->v_comp);
1187		break;
1188	case VBLK_PRT3:
1189		/* Sort by the partition's start sector. */
1190		list_for_each (item, &ldb->v_part) {
1191			struct vblk *v = list_entry (item, struct vblk, list);
1192			if ((v->vblk.part.disk_id == vb->vblk.part.disk_id) &&
1193			    (v->vblk.part.start > vb->vblk.part.start)) {
1194				list_add_tail (&vb->list, &v->list);
1195				return true;
1196			}
1197		}
1198		list_add_tail (&vb->list, &ldb->v_part);
1199		break;
1200	}
1201	return true;
1202}
1203
1204/**
1205 * ldm_frag_add - Add a VBLK fragment to a list
1206 * @data:   Raw fragment to be added to the list
1207 * @size:   Size of the raw fragment
1208 * @frags:  Linked list of VBLK fragments
1209 *
1210 * Fragmented VBLKs may not be consecutive in the database, so they are placed
1211 * in a list so they can be pieced together later.
1212 *
1213 * Return:  'true'   Success, the VBLK was added to the list
1214 *          'false'  Error, a problem occurred
1215 */
1216static bool ldm_frag_add (const u8 *data, int size, struct list_head *frags)
1217{
1218	struct frag *f;
1219	struct list_head *item;
1220	int rec, num, group;
1221
1222	BUG_ON (!data || !frags);
1223
1224	if (size < 2 * VBLK_SIZE_HEAD) {
1225		ldm_error("Value of size is too small.");
1226		return false;
1227	}
1228
1229	group = get_unaligned_be32(data + 0x08);
1230	rec   = get_unaligned_be16(data + 0x0C);
1231	num   = get_unaligned_be16(data + 0x0E);
1232	if ((num < 1) || (num > 4)) {
1233		ldm_error ("A VBLK claims to have %d parts.", num);
1234		return false;
1235	}
1236	if (rec >= num) {
1237		ldm_error("REC value (%d) exceeds NUM value (%d)", rec, num);
1238		return false;
1239	}
1240
1241	list_for_each (item, frags) {
1242		f = list_entry (item, struct frag, list);
1243		if (f->group == group)
1244			goto found;
1245	}
1246
1247	f = kmalloc (sizeof (*f) + size*num, GFP_KERNEL);
1248	if (!f) {
1249		ldm_crit ("Out of memory.");
1250		return false;
1251	}
1252
1253	f->group = group;
1254	f->num   = num;
1255	f->rec   = rec;
1256	f->map   = 0xFF << num;
1257
1258	list_add_tail (&f->list, frags);
1259found:
1260	if (rec >= f->num) {
1261		ldm_error("REC value (%d) exceeds NUM value (%d)", rec, f->num);
1262		return false;
1263	}
1264	if (f->map & (1 << rec)) {
1265		ldm_error ("Duplicate VBLK, part %d.", rec);
1266		f->map &= 0x7F;			/* Mark the group as broken */
1267		return false;
1268	}
1269	f->map |= (1 << rec);
1270	if (!rec)
1271		memcpy(f->data, data, VBLK_SIZE_HEAD);
1272	data += VBLK_SIZE_HEAD;
1273	size -= VBLK_SIZE_HEAD;
1274	memcpy(f->data + VBLK_SIZE_HEAD + rec * size, data, size);
1275	return true;
1276}
1277
1278/**
1279 * ldm_frag_free - Free a linked list of VBLK fragments
1280 * @list:  Linked list of fragments
1281 *
1282 * Free a linked list of VBLK fragments
1283 *
1284 * Return:  none
1285 */
1286static void ldm_frag_free (struct list_head *list)
1287{
1288	struct list_head *item, *tmp;
1289
1290	BUG_ON (!list);
1291
1292	list_for_each_safe (item, tmp, list)
1293		kfree (list_entry (item, struct frag, list));
1294}
1295
1296/**
1297 * ldm_frag_commit - Validate fragmented VBLKs and add them to the database
1298 * @frags:  Linked list of VBLK fragments
1299 * @ldb:    Cache of the database structures
1300 *
1301 * Now that all the fragmented VBLKs have been collected, they must be added to
1302 * the database for later use.
1303 *
1304 * Return:  'true'   All the fragments we added successfully
1305 *          'false'  One or more of the fragments we invalid
1306 */
1307static bool ldm_frag_commit (struct list_head *frags, struct ldmdb *ldb)
1308{
1309	struct frag *f;
1310	struct list_head *item;
1311
1312	BUG_ON (!frags || !ldb);
1313
1314	list_for_each (item, frags) {
1315		f = list_entry (item, struct frag, list);
1316
1317		if (f->map != 0xFF) {
1318			ldm_error ("VBLK group %d is incomplete (0x%02x).",
1319				f->group, f->map);
1320			return false;
1321		}
1322
1323		if (!ldm_ldmdb_add (f->data, f->num*ldb->vm.vblk_size, ldb))
1324			return false;		/* Already logged */
1325	}
1326	return true;
1327}
1328
1329/**
1330 * ldm_get_vblks - Read the on-disk database of VBLKs into memory
1331 * @state: Partition check state including device holding the LDM Database
1332 * @base:  Offset, into @state->disk, of the database
1333 * @ldb:   Cache of the database structures
1334 *
1335 * To use the information from the VBLKs, they need to be read from the disk,
1336 * unpacked and validated.  We cache them in @ldb according to their type.
1337 *
1338 * Return:  'true'   All the VBLKs were read successfully
1339 *          'false'  An error occurred
1340 */
1341static bool ldm_get_vblks(struct parsed_partitions *state, unsigned long base,
1342			  struct ldmdb *ldb)
1343{
1344	int size, perbuf, skip, finish, s, v, recs;
1345	u8 *data = NULL;
1346	Sector sect;
1347	bool result = false;
1348	LIST_HEAD (frags);
1349
1350	BUG_ON(!state || !ldb);
1351
1352	size   = ldb->vm.vblk_size;
1353	perbuf = 512 / size;
1354	skip   = ldb->vm.vblk_offset >> 9;		/* Bytes to sectors */
1355	finish = (size * ldb->vm.last_vblk_seq) >> 9;
1356
1357	for (s = skip; s < finish; s++) {		/* For each sector */
1358		data = read_part_sector(state, base + OFF_VMDB + s, &sect);
1359		if (!data) {
1360			ldm_crit ("Disk read failed.");
1361			goto out;
1362		}
1363
1364		for (v = 0; v < perbuf; v++, data+=size) {  /* For each vblk */
1365			if (MAGIC_VBLK != get_unaligned_be32(data)) {
1366				ldm_error ("Expected to find a VBLK.");
1367				goto out;
1368			}
1369
1370			recs = get_unaligned_be16(data + 0x0E);	/* Number of records */
1371			if (recs == 1) {
1372				if (!ldm_ldmdb_add (data, size, ldb))
1373					goto out;	/* Already logged */
1374			} else if (recs > 1) {
1375				if (!ldm_frag_add (data, size, &frags))
1376					goto out;	/* Already logged */
1377			}
1378			/* else Record is not in use, ignore it. */
1379		}
1380		put_dev_sector (sect);
1381		data = NULL;
1382	}
1383
1384	result = ldm_frag_commit (&frags, ldb);	/* Failures, already logged */
1385out:
1386	if (data)
1387		put_dev_sector (sect);
1388	ldm_frag_free (&frags);
1389
1390	return result;
1391}
1392
1393/**
1394 * ldm_free_vblks - Free a linked list of vblk's
1395 * @lh:  Head of a linked list of struct vblk
1396 *
1397 * Free a list of vblk's and free the memory used to maintain the list.
1398 *
1399 * Return:  none
1400 */
1401static void ldm_free_vblks (struct list_head *lh)
1402{
1403	struct list_head *item, *tmp;
1404
1405	BUG_ON (!lh);
1406
1407	list_for_each_safe (item, tmp, lh)
1408		kfree (list_entry (item, struct vblk, list));
1409}
1410
1411
1412/**
1413 * ldm_partition - Find out whether a device is a dynamic disk and handle it
1414 * @state: Partition check state including device holding the LDM Database
1415 *
1416 * This determines whether the device @bdev is a dynamic disk and if so creates
1417 * the partitions necessary in the gendisk structure pointed to by @hd.
1418 *
1419 * We create a dummy device 1, which contains the LDM database, and then create
1420 * each partition described by the LDM database in sequence as devices 2+. For
1421 * example, if the device is hda, we would have: hda1: LDM database, hda2, hda3,
1422 * and so on: the actual data containing partitions.
1423 *
1424 * Return:  1 Success, @state->disk is a dynamic disk and we handled it
1425 *          0 Success, @state->disk is not a dynamic disk
1426 *         -1 An error occurred before enough information had been read
1427 *            Or @state->disk is a dynamic disk, but it may be corrupted
1428 */
1429int ldm_partition(struct parsed_partitions *state)
1430{
1431	struct ldmdb  *ldb;
1432	unsigned long base;
1433	int result = -1;
1434
1435	BUG_ON(!state);
1436
1437	/* Look for signs of a Dynamic Disk */
1438	if (!ldm_validate_partition_table(state))
1439		return 0;
1440
1441	ldb = kmalloc (sizeof (*ldb), GFP_KERNEL);
1442	if (!ldb) {
1443		ldm_crit ("Out of memory.");
1444		goto out;
1445	}
1446
1447	/* Parse and check privheads. */
1448	if (!ldm_validate_privheads(state, &ldb->ph))
1449		goto out;		/* Already logged */
1450
1451	/* All further references are relative to base (database start). */
1452	base = ldb->ph.config_start;
1453
1454	/* Parse and check tocs and vmdb. */
1455	if (!ldm_validate_tocblocks(state, base, ldb) ||
1456	    !ldm_validate_vmdb(state, base, ldb))
1457	    	goto out;		/* Already logged */
1458
1459	/* Initialize vblk lists in ldmdb struct */
1460	INIT_LIST_HEAD (&ldb->v_dgrp);
1461	INIT_LIST_HEAD (&ldb->v_disk);
1462	INIT_LIST_HEAD (&ldb->v_volu);
1463	INIT_LIST_HEAD (&ldb->v_comp);
1464	INIT_LIST_HEAD (&ldb->v_part);
1465
1466	if (!ldm_get_vblks(state, base, ldb)) {
1467		ldm_crit ("Failed to read the VBLKs from the database.");
1468		goto cleanup;
1469	}
1470
1471	/* Finally, create the data partition devices. */
1472	if (ldm_create_data_partitions(state, ldb)) {
1473		ldm_debug ("Parsed LDM database successfully.");
1474		result = 1;
1475	}
1476	/* else Already logged */
1477
1478cleanup:
1479	ldm_free_vblks (&ldb->v_dgrp);
1480	ldm_free_vblks (&ldb->v_disk);
1481	ldm_free_vblks (&ldb->v_volu);
1482	ldm_free_vblks (&ldb->v_comp);
1483	ldm_free_vblks (&ldb->v_part);
1484out:
1485	kfree (ldb);
1486	return result;
1487}