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Linux/block/partitions/ldm.c

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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 
 18 #include "ldm.h"
 19 #include "check.h"
 20 #include "msdos.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 
 40 static __printf(3, 4)
 41 void _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  */
 67 static 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  */
126 static 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         strncpy (toc->bitmap1_name, data + 0x24, sizeof (toc->bitmap1_name));
135         toc->bitmap1_name[sizeof (toc->bitmap1_name) - 1] = 0;
136         toc->bitmap1_start = get_unaligned_be64(data + 0x2E);
137         toc->bitmap1_size  = get_unaligned_be64(data + 0x36);
138 
139         if (strncmp (toc->bitmap1_name, TOC_BITMAP1,
140                         sizeof (toc->bitmap1_name)) != 0) {
141                 ldm_crit ("TOCBLOCK's first bitmap is '%s', should be '%s'.",
142                                 TOC_BITMAP1, toc->bitmap1_name);
143                 return false;
144         }
145         strncpy (toc->bitmap2_name, data + 0x46, sizeof (toc->bitmap2_name));
146         toc->bitmap2_name[sizeof (toc->bitmap2_name) - 1] = 0;
147         toc->bitmap2_start = get_unaligned_be64(data + 0x50);
148         toc->bitmap2_size  = get_unaligned_be64(data + 0x58);
149         if (strncmp (toc->bitmap2_name, TOC_BITMAP2,
150                         sizeof (toc->bitmap2_name)) != 0) {
151                 ldm_crit ("TOCBLOCK's second bitmap is '%s', should be '%s'.",
152                                 TOC_BITMAP2, toc->bitmap2_name);
153                 return false;
154         }
155         ldm_debug ("Parsed TOCBLOCK successfully.");
156         return true;
157 }
158 
159 /**
160  * ldm_parse_vmdb - Read the LDM Database VMDB structure
161  * @data:  Raw database VMDB structure loaded from the device
162  * @vm:    In-memory vmdb structure in which to return parsed information
163  *
164  * This parses the LDM Database VMDB structure supplied in @data and sets up
165  * the in-memory vmdb structure @vm with the obtained information.
166  *
167  * N.B.  The *_start, *_size and *_seq values will be range-checked later.
168  *
169  * Return:  'true'   @vm contains VMDB info
170  *          'false'  @vm contents are undefined
171  */
172 static bool ldm_parse_vmdb (const u8 *data, struct vmdb *vm)
173 {
174         BUG_ON (!data || !vm);
175 
176         if (MAGIC_VMDB != get_unaligned_be32(data)) {
177                 ldm_crit ("Cannot find the VMDB, database may be corrupt.");
178                 return false;
179         }
180 
181         vm->ver_major = get_unaligned_be16(data + 0x12);
182         vm->ver_minor = get_unaligned_be16(data + 0x14);
183         if ((vm->ver_major != 4) || (vm->ver_minor != 10)) {
184                 ldm_error ("Expected VMDB version %d.%d, got %d.%d. "
185                         "Aborting.", 4, 10, vm->ver_major, vm->ver_minor);
186                 return false;
187         }
188 
189         vm->vblk_size     = get_unaligned_be32(data + 0x08);
190         if (vm->vblk_size == 0) {
191                 ldm_error ("Illegal VBLK size");
192                 return false;
193         }
194 
195         vm->vblk_offset   = get_unaligned_be32(data + 0x0C);
196         vm->last_vblk_seq = get_unaligned_be32(data + 0x04);
197 
198         ldm_debug ("Parsed VMDB successfully.");
199         return true;
200 }
201 
202 /**
203  * ldm_compare_privheads - Compare two privhead objects
204  * @ph1:  First privhead
205  * @ph2:  Second privhead
206  *
207  * This compares the two privhead structures @ph1 and @ph2.
208  *
209  * Return:  'true'   Identical
210  *          'false'  Different
211  */
212 static bool ldm_compare_privheads (const struct privhead *ph1,
213                                    const struct privhead *ph2)
214 {
215         BUG_ON (!ph1 || !ph2);
216 
217         return ((ph1->ver_major          == ph2->ver_major)             &&
218                 (ph1->ver_minor          == ph2->ver_minor)             &&
219                 (ph1->logical_disk_start == ph2->logical_disk_start)    &&
220                 (ph1->logical_disk_size  == ph2->logical_disk_size)     &&
221                 (ph1->config_start       == ph2->config_start)          &&
222                 (ph1->config_size        == ph2->config_size)           &&
223                 uuid_equal(&ph1->disk_id, &ph2->disk_id));
224 }
225 
226 /**
227  * ldm_compare_tocblocks - Compare two tocblock objects
228  * @toc1:  First toc
229  * @toc2:  Second toc
230  *
231  * This compares the two tocblock structures @toc1 and @toc2.
232  *
233  * Return:  'true'   Identical
234  *          'false'  Different
235  */
236 static bool ldm_compare_tocblocks (const struct tocblock *toc1,
237                                    const struct tocblock *toc2)
238 {
239         BUG_ON (!toc1 || !toc2);
240 
241         return ((toc1->bitmap1_start == toc2->bitmap1_start)    &&
242                 (toc1->bitmap1_size  == toc2->bitmap1_size)     &&
243                 (toc1->bitmap2_start == toc2->bitmap2_start)    &&
244                 (toc1->bitmap2_size  == toc2->bitmap2_size)     &&
245                 !strncmp (toc1->bitmap1_name, toc2->bitmap1_name,
246                         sizeof (toc1->bitmap1_name))            &&
247                 !strncmp (toc1->bitmap2_name, toc2->bitmap2_name,
248                         sizeof (toc1->bitmap2_name)));
249 }
250 
251 /**
252  * ldm_validate_privheads - Compare the primary privhead with its backups
253  * @state: Partition check state including device holding the LDM Database
254  * @ph1:   Memory struct to fill with ph contents
255  *
256  * Read and compare all three privheads from disk.
257  *
258  * The privheads on disk show the size and location of the main disk area and
259  * the configuration area (the database).  The values are range-checked against
260  * @hd, which contains the real size of the disk.
261  *
262  * Return:  'true'   Success
263  *          'false'  Error
264  */
265 static bool ldm_validate_privheads(struct parsed_partitions *state,
266                                    struct privhead *ph1)
267 {
268         static const int off[3] = { OFF_PRIV1, OFF_PRIV2, OFF_PRIV3 };
269         struct privhead *ph[3] = { ph1 };
270         Sector sect;
271         u8 *data;
272         bool result = false;
273         long num_sects;
274         int i;
275 
276         BUG_ON (!state || !ph1);
277 
278         ph[1] = kmalloc (sizeof (*ph[1]), GFP_KERNEL);
279         ph[2] = kmalloc (sizeof (*ph[2]), GFP_KERNEL);
280         if (!ph[1] || !ph[2]) {
281                 ldm_crit ("Out of memory.");
282                 goto out;
283         }
284 
285         /* off[1 & 2] are relative to ph[0]->config_start */
286         ph[0]->config_start = 0;
287 
288         /* Read and parse privheads */
289         for (i = 0; i < 3; i++) {
290                 data = read_part_sector(state, ph[0]->config_start + off[i],
291                                         &sect);
292                 if (!data) {
293                         ldm_crit ("Disk read failed.");
294                         goto out;
295                 }
296                 result = ldm_parse_privhead (data, ph[i]);
297                 put_dev_sector (sect);
298                 if (!result) {
299                         ldm_error ("Cannot find PRIVHEAD %d.", i+1); /* Log again */
300                         if (i < 2)
301                                 goto out;       /* Already logged */
302                         else
303                                 break;  /* FIXME ignore for now, 3rd PH can fail on odd-sized disks */
304                 }
305         }
306 
307         num_sects = state->bdev->bd_inode->i_size >> 9;
308 
309         if ((ph[0]->config_start > num_sects) ||
310            ((ph[0]->config_start + ph[0]->config_size) > num_sects)) {
311                 ldm_crit ("Database extends beyond the end of the disk.");
312                 goto out;
313         }
314 
315         if ((ph[0]->logical_disk_start > ph[0]->config_start) ||
316            ((ph[0]->logical_disk_start + ph[0]->logical_disk_size)
317                     > ph[0]->config_start)) {
318                 ldm_crit ("Disk and database overlap.");
319                 goto out;
320         }
321 
322         if (!ldm_compare_privheads (ph[0], ph[1])) {
323                 ldm_crit ("Primary and backup PRIVHEADs don't match.");
324                 goto out;
325         }
326         /* FIXME ignore this for now
327         if (!ldm_compare_privheads (ph[0], ph[2])) {
328                 ldm_crit ("Primary and backup PRIVHEADs don't match.");
329                 goto out;
330         }*/
331         ldm_debug ("Validated PRIVHEADs successfully.");
332         result = true;
333 out:
334         kfree (ph[1]);
335         kfree (ph[2]);
336         return result;
337 }
338 
339 /**
340  * ldm_validate_tocblocks - Validate the table of contents and its backups
341  * @state: Partition check state including device holding the LDM Database
342  * @base:  Offset, into @state->bdev, of the database
343  * @ldb:   Cache of the database structures
344  *
345  * Find and compare the four tables of contents of the LDM Database stored on
346  * @state->bdev and return the parsed information into @toc1.
347  *
348  * The offsets and sizes of the configs are range-checked against a privhead.
349  *
350  * Return:  'true'   @toc1 contains validated TOCBLOCK info
351  *          'false'  @toc1 contents are undefined
352  */
353 static bool ldm_validate_tocblocks(struct parsed_partitions *state,
354                                    unsigned long base, struct ldmdb *ldb)
355 {
356         static const int off[4] = { OFF_TOCB1, OFF_TOCB2, OFF_TOCB3, OFF_TOCB4};
357         struct tocblock *tb[4];
358         struct privhead *ph;
359         Sector sect;
360         u8 *data;
361         int i, nr_tbs;
362         bool result = false;
363 
364         BUG_ON(!state || !ldb);
365         ph = &ldb->ph;
366         tb[0] = &ldb->toc;
367         tb[1] = kmalloc_array(3, sizeof(*tb[1]), GFP_KERNEL);
368         if (!tb[1]) {
369                 ldm_crit("Out of memory.");
370                 goto err;
371         }
372         tb[2] = (struct tocblock*)((u8*)tb[1] + sizeof(*tb[1]));
373         tb[3] = (struct tocblock*)((u8*)tb[2] + sizeof(*tb[2]));
374         /*
375          * Try to read and parse all four TOCBLOCKs.
376          *
377          * Windows Vista LDM v2.12 does not always have all four TOCBLOCKs so
378          * skip any that fail as long as we get at least one valid TOCBLOCK.
379          */
380         for (nr_tbs = i = 0; i < 4; i++) {
381                 data = read_part_sector(state, base + off[i], &sect);
382                 if (!data) {
383                         ldm_error("Disk read failed for TOCBLOCK %d.", i);
384                         continue;
385                 }
386                 if (ldm_parse_tocblock(data, tb[nr_tbs]))
387                         nr_tbs++;
388                 put_dev_sector(sect);
389         }
390         if (!nr_tbs) {
391                 ldm_crit("Failed to find a valid TOCBLOCK.");
392                 goto err;
393         }
394         /* Range check the TOCBLOCK against a privhead. */
395         if (((tb[0]->bitmap1_start + tb[0]->bitmap1_size) > ph->config_size) ||
396                         ((tb[0]->bitmap2_start + tb[0]->bitmap2_size) >
397                         ph->config_size)) {
398                 ldm_crit("The bitmaps are out of range.  Giving up.");
399                 goto err;
400         }
401         /* Compare all loaded TOCBLOCKs. */
402         for (i = 1; i < nr_tbs; i++) {
403                 if (!ldm_compare_tocblocks(tb[0], tb[i])) {
404                         ldm_crit("TOCBLOCKs 0 and %d do not match.", i);
405                         goto err;
406                 }
407         }
408         ldm_debug("Validated %d TOCBLOCKs successfully.", nr_tbs);
409         result = true;
410 err:
411         kfree(tb[1]);
412         return result;
413 }
414 
415 /**
416  * ldm_validate_vmdb - Read the VMDB and validate it
417  * @state: Partition check state including device holding the LDM Database
418  * @base:  Offset, into @bdev, of the database
419  * @ldb:   Cache of the database structures
420  *
421  * Find the vmdb of the LDM Database stored on @bdev and return the parsed
422  * information in @ldb.
423  *
424  * Return:  'true'   @ldb contains validated VBDB info
425  *          'false'  @ldb contents are undefined
426  */
427 static bool ldm_validate_vmdb(struct parsed_partitions *state,
428                               unsigned long base, struct ldmdb *ldb)
429 {
430         Sector sect;
431         u8 *data;
432         bool result = false;
433         struct vmdb *vm;
434         struct tocblock *toc;
435 
436         BUG_ON (!state || !ldb);
437 
438         vm  = &ldb->vm;
439         toc = &ldb->toc;
440 
441         data = read_part_sector(state, base + OFF_VMDB, &sect);
442         if (!data) {
443                 ldm_crit ("Disk read failed.");
444                 return false;
445         }
446 
447         if (!ldm_parse_vmdb (data, vm))
448                 goto out;                               /* Already logged */
449 
450         /* Are there uncommitted transactions? */
451         if (get_unaligned_be16(data + 0x10) != 0x01) {
452                 ldm_crit ("Database is not in a consistent state.  Aborting.");
453                 goto out;
454         }
455 
456         if (vm->vblk_offset != 512)
457                 ldm_info ("VBLKs start at offset 0x%04x.", vm->vblk_offset);
458 
459         /*
460          * The last_vblkd_seq can be before the end of the vmdb, just make sure
461          * it is not out of bounds.
462          */
463         if ((vm->vblk_size * vm->last_vblk_seq) > (toc->bitmap1_size << 9)) {
464                 ldm_crit ("VMDB exceeds allowed size specified by TOCBLOCK.  "
465                                 "Database is corrupt.  Aborting.");
466                 goto out;
467         }
468 
469         result = true;
470 out:
471         put_dev_sector (sect);
472         return result;
473 }
474 
475 
476 /**
477  * ldm_validate_partition_table - Determine whether bdev might be a dynamic disk
478  * @state: Partition check state including device holding the LDM Database
479  *
480  * This function provides a weak test to decide whether the device is a dynamic
481  * disk or not.  It looks for an MS-DOS-style partition table containing at
482  * least one partition of type 0x42 (formerly SFS, now used by Windows for
483  * dynamic disks).
484  *
485  * N.B.  The only possible error can come from the read_part_sector and that is
486  *       only likely to happen if the underlying device is strange.  If that IS
487  *       the case we should return zero to let someone else try.
488  *
489  * Return:  'true'   @state->bdev is a dynamic disk
490  *          'false'  @state->bdev is not a dynamic disk, or an error occurred
491  */
492 static bool ldm_validate_partition_table(struct parsed_partitions *state)
493 {
494         Sector sect;
495         u8 *data;
496         struct partition *p;
497         int i;
498         bool result = false;
499 
500         BUG_ON(!state);
501 
502         data = read_part_sector(state, 0, &sect);
503         if (!data) {
504                 ldm_info ("Disk read failed.");
505                 return false;
506         }
507 
508         if (*(__le16*) (data + 0x01FE) != cpu_to_le16 (MSDOS_LABEL_MAGIC))
509                 goto out;
510 
511         p = (struct partition*)(data + 0x01BE);
512         for (i = 0; i < 4; i++, p++)
513                 if (SYS_IND (p) == LDM_PARTITION) {
514                         result = true;
515                         break;
516                 }
517 
518         if (result)
519                 ldm_debug ("Found W2K dynamic disk partition type.");
520 
521 out:
522         put_dev_sector (sect);
523         return result;
524 }
525 
526 /**
527  * ldm_get_disk_objid - Search a linked list of vblk's for a given Disk Id
528  * @ldb:  Cache of the database structures
529  *
530  * The LDM Database contains a list of all partitions on all dynamic disks.
531  * The primary PRIVHEAD, at the beginning of the physical disk, tells us
532  * the GUID of this disk.  This function searches for the GUID in a linked
533  * list of vblk's.
534  *
535  * Return:  Pointer, A matching vblk was found
536  *          NULL,    No match, or an error
537  */
538 static struct vblk * ldm_get_disk_objid (const struct ldmdb *ldb)
539 {
540         struct list_head *item;
541 
542         BUG_ON (!ldb);
543 
544         list_for_each (item, &ldb->v_disk) {
545                 struct vblk *v = list_entry (item, struct vblk, list);
546                 if (uuid_equal(&v->vblk.disk.disk_id, &ldb->ph.disk_id))
547                         return v;
548         }
549 
550         return NULL;
551 }
552 
553 /**
554  * ldm_create_data_partitions - Create data partitions for this device
555  * @pp:   List of the partitions parsed so far
556  * @ldb:  Cache of the database structures
557  *
558  * The database contains ALL the partitions for ALL disk groups, so we need to
559  * filter out this specific disk. Using the disk's object id, we can find all
560  * the partitions in the database that belong to this disk.
561  *
562  * Add each partition in our database, to the parsed_partitions structure.
563  *
564  * N.B.  This function creates the partitions in the order it finds partition
565  *       objects in the linked list.
566  *
567  * Return:  'true'   Partition created
568  *          'false'  Error, probably a range checking problem
569  */
570 static bool ldm_create_data_partitions (struct parsed_partitions *pp,
571                                         const struct ldmdb *ldb)
572 {
573         struct list_head *item;
574         struct vblk *vb;
575         struct vblk *disk;
576         struct vblk_part *part;
577         int part_num = 1;
578 
579         BUG_ON (!pp || !ldb);
580 
581         disk = ldm_get_disk_objid (ldb);
582         if (!disk) {
583                 ldm_crit ("Can't find the ID of this disk in the database.");
584                 return false;
585         }
586 
587         strlcat(pp->pp_buf, " [LDM]", PAGE_SIZE);
588 
589         /* Create the data partitions */
590         list_for_each (item, &ldb->v_part) {
591                 vb = list_entry (item, struct vblk, list);
592                 part = &vb->vblk.part;
593 
594                 if (part->disk_id != disk->obj_id)
595                         continue;
596 
597                 put_partition (pp, part_num, ldb->ph.logical_disk_start +
598                                 part->start, part->size);
599                 part_num++;
600         }
601 
602         strlcat(pp->pp_buf, "\n", PAGE_SIZE);
603         return true;
604 }
605 
606 
607 /**
608  * ldm_relative - Calculate the next relative offset
609  * @buffer:  Block of data being worked on
610  * @buflen:  Size of the block of data
611  * @base:    Size of the previous fixed width fields
612  * @offset:  Cumulative size of the previous variable-width fields
613  *
614  * Because many of the VBLK fields are variable-width, it's necessary
615  * to calculate each offset based on the previous one and the length
616  * of the field it pointed to.
617  *
618  * Return:  -1 Error, the calculated offset exceeded the size of the buffer
619  *           n OK, a range-checked offset into buffer
620  */
621 static int ldm_relative(const u8 *buffer, int buflen, int base, int offset)
622 {
623 
624         base += offset;
625         if (!buffer || offset < 0 || base > buflen) {
626                 if (!buffer)
627                         ldm_error("!buffer");
628                 if (offset < 0)
629                         ldm_error("offset (%d) < 0", offset);
630                 if (base > buflen)
631                         ldm_error("base (%d) > buflen (%d)", base, buflen);
632                 return -1;
633         }
634         if (base + buffer[base] >= buflen) {
635                 ldm_error("base (%d) + buffer[base] (%d) >= buflen (%d)", base,
636                                 buffer[base], buflen);
637                 return -1;
638         }
639         return buffer[base] + offset + 1;
640 }
641 
642 /**
643  * ldm_get_vnum - Convert a variable-width, big endian number, into cpu order
644  * @block:  Pointer to the variable-width number to convert
645  *
646  * Large numbers in the LDM Database are often stored in a packed format.  Each
647  * number is prefixed by a one byte width marker.  All numbers in the database
648  * are stored in big-endian byte order.  This function reads one of these
649  * numbers and returns the result
650  *
651  * N.B.  This function DOES NOT perform any range checking, though the most
652  *       it will read is eight bytes.
653  *
654  * Return:  n A number
655  *          0 Zero, or an error occurred
656  */
657 static u64 ldm_get_vnum (const u8 *block)
658 {
659         u64 tmp = 0;
660         u8 length;
661 
662         BUG_ON (!block);
663 
664         length = *block++;
665 
666         if (length && length <= 8)
667                 while (length--)
668                         tmp = (tmp << 8) | *block++;
669         else
670                 ldm_error ("Illegal length %d.", length);
671 
672         return tmp;
673 }
674 
675 /**
676  * ldm_get_vstr - Read a length-prefixed string into a buffer
677  * @block:   Pointer to the length marker
678  * @buffer:  Location to copy string to
679  * @buflen:  Size of the output buffer
680  *
681  * Many of the strings in the LDM Database are not NULL terminated.  Instead
682  * they are prefixed by a one byte length marker.  This function copies one of
683  * these strings into a buffer.
684  *
685  * N.B.  This function DOES NOT perform any range checking on the input.
686  *       If the buffer is too small, the output will be truncated.
687  *
688  * Return:  0, Error and @buffer contents are undefined
689  *          n, String length in characters (excluding NULL)
690  *          buflen-1, String was truncated.
691  */
692 static int ldm_get_vstr (const u8 *block, u8 *buffer, int buflen)
693 {
694         int length;
695 
696         BUG_ON (!block || !buffer);
697 
698         length = block[0];
699         if (length >= buflen) {
700                 ldm_error ("Truncating string %d -> %d.", length, buflen);
701                 length = buflen - 1;
702         }
703         memcpy (buffer, block + 1, length);
704         buffer[length] = 0;
705         return length;
706 }
707 
708 
709 /**
710  * ldm_parse_cmp3 - Read a raw VBLK Component object into a vblk structure
711  * @buffer:  Block of data being worked on
712  * @buflen:  Size of the block of data
713  * @vb:      In-memory vblk in which to return information
714  *
715  * Read a raw VBLK Component object (version 3) into a vblk structure.
716  *
717  * Return:  'true'   @vb contains a Component VBLK
718  *          'false'  @vb contents are not defined
719  */
720 static bool ldm_parse_cmp3 (const u8 *buffer, int buflen, struct vblk *vb)
721 {
722         int r_objid, r_name, r_vstate, r_child, r_parent, r_stripe, r_cols, len;
723         struct vblk_comp *comp;
724 
725         BUG_ON (!buffer || !vb);
726 
727         r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
728         r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
729         r_vstate = ldm_relative (buffer, buflen, 0x18, r_name);
730         r_child  = ldm_relative (buffer, buflen, 0x1D, r_vstate);
731         r_parent = ldm_relative (buffer, buflen, 0x2D, r_child);
732 
733         if (buffer[0x12] & VBLK_FLAG_COMP_STRIPE) {
734                 r_stripe = ldm_relative (buffer, buflen, 0x2E, r_parent);
735                 r_cols   = ldm_relative (buffer, buflen, 0x2E, r_stripe);
736                 len = r_cols;
737         } else {
738                 r_stripe = 0;
739                 r_cols   = 0;
740                 len = r_parent;
741         }
742         if (len < 0)
743                 return false;
744 
745         len += VBLK_SIZE_CMP3;
746         if (len != get_unaligned_be32(buffer + 0x14))
747                 return false;
748 
749         comp = &vb->vblk.comp;
750         ldm_get_vstr (buffer + 0x18 + r_name, comp->state,
751                 sizeof (comp->state));
752         comp->type      = buffer[0x18 + r_vstate];
753         comp->children  = ldm_get_vnum (buffer + 0x1D + r_vstate);
754         comp->parent_id = ldm_get_vnum (buffer + 0x2D + r_child);
755         comp->chunksize = r_stripe ? ldm_get_vnum (buffer+r_parent+0x2E) : 0;
756 
757         return true;
758 }
759 
760 /**
761  * ldm_parse_dgr3 - Read a raw VBLK Disk Group object into a vblk structure
762  * @buffer:  Block of data being worked on
763  * @buflen:  Size of the block of data
764  * @vb:      In-memory vblk in which to return information
765  *
766  * Read a raw VBLK Disk Group object (version 3) into a vblk structure.
767  *
768  * Return:  'true'   @vb contains a Disk Group VBLK
769  *          'false'  @vb contents are not defined
770  */
771 static int ldm_parse_dgr3 (const u8 *buffer, int buflen, struct vblk *vb)
772 {
773         int r_objid, r_name, r_diskid, r_id1, r_id2, len;
774         struct vblk_dgrp *dgrp;
775 
776         BUG_ON (!buffer || !vb);
777 
778         r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
779         r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
780         r_diskid = ldm_relative (buffer, buflen, 0x18, r_name);
781 
782         if (buffer[0x12] & VBLK_FLAG_DGR3_IDS) {
783                 r_id1 = ldm_relative (buffer, buflen, 0x24, r_diskid);
784                 r_id2 = ldm_relative (buffer, buflen, 0x24, r_id1);
785                 len = r_id2;
786         } else {
787                 r_id1 = 0;
788                 r_id2 = 0;
789                 len = r_diskid;
790         }
791         if (len < 0)
792                 return false;
793 
794         len += VBLK_SIZE_DGR3;
795         if (len != get_unaligned_be32(buffer + 0x14))
796                 return false;
797 
798         dgrp = &vb->vblk.dgrp;
799         ldm_get_vstr (buffer + 0x18 + r_name, dgrp->disk_id,
800                 sizeof (dgrp->disk_id));
801         return true;
802 }
803 
804 /**
805  * ldm_parse_dgr4 - Read a raw VBLK Disk Group object into a vblk structure
806  * @buffer:  Block of data being worked on
807  * @buflen:  Size of the block of data
808  * @vb:      In-memory vblk in which to return information
809  *
810  * Read a raw VBLK Disk Group object (version 4) into a vblk structure.
811  *
812  * Return:  'true'   @vb contains a Disk Group VBLK
813  *          'false'  @vb contents are not defined
814  */
815 static bool ldm_parse_dgr4 (const u8 *buffer, int buflen, struct vblk *vb)
816 {
817         char buf[64];
818         int r_objid, r_name, r_id1, r_id2, len;
819 
820         BUG_ON (!buffer || !vb);
821 
822         r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
823         r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
824 
825         if (buffer[0x12] & VBLK_FLAG_DGR4_IDS) {
826                 r_id1 = ldm_relative (buffer, buflen, 0x44, r_name);
827                 r_id2 = ldm_relative (buffer, buflen, 0x44, r_id1);
828                 len = r_id2;
829         } else {
830                 r_id1 = 0;
831                 r_id2 = 0;
832                 len = r_name;
833         }
834         if (len < 0)
835                 return false;
836 
837         len += VBLK_SIZE_DGR4;
838         if (len != get_unaligned_be32(buffer + 0x14))
839                 return false;
840 
841         ldm_get_vstr (buffer + 0x18 + r_objid, buf, sizeof (buf));
842         return true;
843 }
844 
845 /**
846  * ldm_parse_dsk3 - Read a raw VBLK Disk object into a vblk structure
847  * @buffer:  Block of data being worked on
848  * @buflen:  Size of the block of data
849  * @vb:      In-memory vblk in which to return information
850  *
851  * Read a raw VBLK Disk object (version 3) into a vblk structure.
852  *
853  * Return:  'true'   @vb contains a Disk VBLK
854  *          'false'  @vb contents are not defined
855  */
856 static bool ldm_parse_dsk3 (const u8 *buffer, int buflen, struct vblk *vb)
857 {
858         int r_objid, r_name, r_diskid, r_altname, len;
859         struct vblk_disk *disk;
860 
861         BUG_ON (!buffer || !vb);
862 
863         r_objid   = ldm_relative (buffer, buflen, 0x18, 0);
864         r_name    = ldm_relative (buffer, buflen, 0x18, r_objid);
865         r_diskid  = ldm_relative (buffer, buflen, 0x18, r_name);
866         r_altname = ldm_relative (buffer, buflen, 0x18, r_diskid);
867         len = r_altname;
868         if (len < 0)
869                 return false;
870 
871         len += VBLK_SIZE_DSK3;
872         if (len != get_unaligned_be32(buffer + 0x14))
873                 return false;
874 
875         disk = &vb->vblk.disk;
876         ldm_get_vstr (buffer + 0x18 + r_diskid, disk->alt_name,
877                 sizeof (disk->alt_name));
878         if (uuid_parse(buffer + 0x19 + r_name, &disk->disk_id))
879                 return false;
880 
881         return true;
882 }
883 
884 /**
885  * ldm_parse_dsk4 - Read a raw VBLK Disk object into a vblk structure
886  * @buffer:  Block of data being worked on
887  * @buflen:  Size of the block of data
888  * @vb:      In-memory vblk in which to return information
889  *
890  * Read a raw VBLK Disk object (version 4) into a vblk structure.
891  *
892  * Return:  'true'   @vb contains a Disk VBLK
893  *          'false'  @vb contents are not defined
894  */
895 static bool ldm_parse_dsk4 (const u8 *buffer, int buflen, struct vblk *vb)
896 {
897         int r_objid, r_name, len;
898         struct vblk_disk *disk;
899 
900         BUG_ON (!buffer || !vb);
901 
902         r_objid = ldm_relative (buffer, buflen, 0x18, 0);
903         r_name  = ldm_relative (buffer, buflen, 0x18, r_objid);
904         len     = r_name;
905         if (len < 0)
906                 return false;
907 
908         len += VBLK_SIZE_DSK4;
909         if (len != get_unaligned_be32(buffer + 0x14))
910                 return false;
911 
912         disk = &vb->vblk.disk;
913         uuid_copy(&disk->disk_id, (uuid_t *)(buffer + 0x18 + r_name));
914         return true;
915 }
916 
917 /**
918  * ldm_parse_prt3 - Read a raw VBLK Partition object into a vblk structure
919  * @buffer:  Block of data being worked on
920  * @buflen:  Size of the block of data
921  * @vb:      In-memory vblk in which to return information
922  *
923  * Read a raw VBLK Partition object (version 3) into a vblk structure.
924  *
925  * Return:  'true'   @vb contains a Partition VBLK
926  *          'false'  @vb contents are not defined
927  */
928 static bool ldm_parse_prt3(const u8 *buffer, int buflen, struct vblk *vb)
929 {
930         int r_objid, r_name, r_size, r_parent, r_diskid, r_index, len;
931         struct vblk_part *part;
932 
933         BUG_ON(!buffer || !vb);
934         r_objid = ldm_relative(buffer, buflen, 0x18, 0);
935         if (r_objid < 0) {
936                 ldm_error("r_objid %d < 0", r_objid);
937                 return false;
938         }
939         r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
940         if (r_name < 0) {
941                 ldm_error("r_name %d < 0", r_name);
942                 return false;
943         }
944         r_size = ldm_relative(buffer, buflen, 0x34, r_name);
945         if (r_size < 0) {
946                 ldm_error("r_size %d < 0", r_size);
947                 return false;
948         }
949         r_parent = ldm_relative(buffer, buflen, 0x34, r_size);
950         if (r_parent < 0) {
951                 ldm_error("r_parent %d < 0", r_parent);
952                 return false;
953         }
954         r_diskid = ldm_relative(buffer, buflen, 0x34, r_parent);
955         if (r_diskid < 0) {
956                 ldm_error("r_diskid %d < 0", r_diskid);
957                 return false;
958         }
959         if (buffer[0x12] & VBLK_FLAG_PART_INDEX) {
960                 r_index = ldm_relative(buffer, buflen, 0x34, r_diskid);
961                 if (r_index < 0) {
962                         ldm_error("r_index %d < 0", r_index);
963                         return false;
964                 }
965                 len = r_index;
966         } else {
967                 r_index = 0;
968                 len = r_diskid;
969         }
970         if (len < 0) {
971                 ldm_error("len %d < 0", len);
972                 return false;
973         }
974         len += VBLK_SIZE_PRT3;
975         if (len > get_unaligned_be32(buffer + 0x14)) {
976                 ldm_error("len %d > BE32(buffer + 0x14) %d", len,
977                                 get_unaligned_be32(buffer + 0x14));
978                 return false;
979         }
980         part = &vb->vblk.part;
981         part->start = get_unaligned_be64(buffer + 0x24 + r_name);
982         part->volume_offset = get_unaligned_be64(buffer + 0x2C + r_name);
983         part->size = ldm_get_vnum(buffer + 0x34 + r_name);
984         part->parent_id = ldm_get_vnum(buffer + 0x34 + r_size);
985         part->disk_id = ldm_get_vnum(buffer + 0x34 + r_parent);
986         if (vb->flags & VBLK_FLAG_PART_INDEX)
987                 part->partnum = buffer[0x35 + r_diskid];
988         else
989                 part->partnum = 0;
990         return true;
991 }
992 
993 /**
994  * ldm_parse_vol5 - Read a raw VBLK Volume object into a vblk structure
995  * @buffer:  Block of data being worked on
996  * @buflen:  Size of the block of data
997  * @vb:      In-memory vblk in which to return information
998  *
999  * Read a raw VBLK Volume object (version 5) into a vblk structure.
1000  *
1001  * Return:  'true'   @vb contains a Volume VBLK
1002  *          'false'  @vb contents are not defined
1003  */
1004 static bool ldm_parse_vol5(const u8 *buffer, int buflen, struct vblk *vb)
1005 {
1006         int r_objid, r_name, r_vtype, r_disable_drive_letter, r_child, r_size;
1007         int r_id1, r_id2, r_size2, r_drive, len;
1008         struct vblk_volu *volu;
1009 
1010         BUG_ON(!buffer || !vb);
1011         r_objid = ldm_relative(buffer, buflen, 0x18, 0);
1012         if (r_objid < 0) {
1013                 ldm_error("r_objid %d < 0", r_objid);
1014                 return false;
1015         }
1016         r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
1017         if (r_name < 0) {
1018                 ldm_error("r_name %d < 0", r_name);
1019                 return false;
1020         }
1021         r_vtype = ldm_relative(buffer, buflen, 0x18, r_name);
1022         if (r_vtype < 0) {
1023                 ldm_error("r_vtype %d < 0", r_vtype);
1024                 return false;
1025         }
1026         r_disable_drive_letter = ldm_relative(buffer, buflen, 0x18, r_vtype);
1027         if (r_disable_drive_letter < 0) {
1028                 ldm_error("r_disable_drive_letter %d < 0",
1029                                 r_disable_drive_letter);
1030                 return false;
1031         }
1032         r_child = ldm_relative(buffer, buflen, 0x2D, r_disable_drive_letter);
1033         if (r_child < 0) {
1034                 ldm_error("r_child %d < 0", r_child);
1035                 return false;
1036         }
1037         r_size = ldm_relative(buffer, buflen, 0x3D, r_child);
1038         if (r_size < 0) {
1039                 ldm_error("r_size %d < 0", r_size);
1040                 return false;
1041         }
1042         if (buffer[0x12] & VBLK_FLAG_VOLU_ID1) {
1043                 r_id1 = ldm_relative(buffer, buflen, 0x52, r_size);
1044                 if (r_id1 < 0) {
1045                         ldm_error("r_id1 %d < 0", r_id1);
1046                         return false;
1047                 }
1048         } else
1049                 r_id1 = r_size;
1050         if (buffer[0x12] & VBLK_FLAG_VOLU_ID2) {
1051                 r_id2 = ldm_relative(buffer, buflen, 0x52, r_id1);
1052                 if (r_id2 < 0) {
1053                         ldm_error("r_id2 %d < 0", r_id2);
1054                         return false;
1055                 }
1056         } else
1057                 r_id2 = r_id1;
1058         if (buffer[0x12] & VBLK_FLAG_VOLU_SIZE) {
1059                 r_size2 = ldm_relative(buffer, buflen, 0x52, r_id2);
1060                 if (r_size2 < 0) {
1061                         ldm_error("r_size2 %d < 0", r_size2);
1062                         return false;
1063                 }
1064         } else
1065                 r_size2 = r_id2;
1066         if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
1067                 r_drive = ldm_relative(buffer, buflen, 0x52, r_size2);
1068                 if (r_drive < 0) {
1069                         ldm_error("r_drive %d < 0", r_drive);
1070                         return false;
1071                 }
1072         } else
1073                 r_drive = r_size2;
1074         len = r_drive;
1075         if (len < 0) {
1076                 ldm_error("len %d < 0", len);
1077                 return false;
1078         }
1079         len += VBLK_SIZE_VOL5;
1080         if (len > get_unaligned_be32(buffer + 0x14)) {
1081                 ldm_error("len %d > BE32(buffer + 0x14) %d", len,
1082                                 get_unaligned_be32(buffer + 0x14));
1083                 return false;
1084         }
1085         volu = &vb->vblk.volu;
1086         ldm_get_vstr(buffer + 0x18 + r_name, volu->volume_type,
1087                         sizeof(volu->volume_type));
1088         memcpy(volu->volume_state, buffer + 0x18 + r_disable_drive_letter,
1089                         sizeof(volu->volume_state));
1090         volu->size = ldm_get_vnum(buffer + 0x3D + r_child);
1091         volu->partition_type = buffer[0x41 + r_size];
1092         memcpy(volu->guid, buffer + 0x42 + r_size, sizeof(volu->guid));
1093         if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
1094                 ldm_get_vstr(buffer + 0x52 + r_size, volu->drive_hint,
1095                                 sizeof(volu->drive_hint));
1096         }
1097         return true;
1098 }
1099 
1100 /**
1101  * ldm_parse_vblk - Read a raw VBLK object into a vblk structure
1102  * @buf:  Block of data being worked on
1103  * @len:  Size of the block of data
1104  * @vb:   In-memory vblk in which to return information
1105  *
1106  * Read a raw VBLK object into a vblk structure.  This function just reads the
1107  * information common to all VBLK types, then delegates the rest of the work to
1108  * helper functions: ldm_parse_*.
1109  *
1110  * Return:  'true'   @vb contains a VBLK
1111  *          'false'  @vb contents are not defined
1112  */
1113 static bool ldm_parse_vblk (const u8 *buf, int len, struct vblk *vb)
1114 {
1115         bool result = false;
1116         int r_objid;
1117 
1118         BUG_ON (!buf || !vb);
1119 
1120         r_objid = ldm_relative (buf, len, 0x18, 0);
1121         if (r_objid < 0) {
1122                 ldm_error ("VBLK header is corrupt.");
1123                 return false;
1124         }
1125 
1126         vb->flags  = buf[0x12];
1127         vb->type   = buf[0x13];
1128         vb->obj_id = ldm_get_vnum (buf + 0x18);
1129         ldm_get_vstr (buf+0x18+r_objid, vb->name, sizeof (vb->name));
1130 
1131         switch (vb->type) {
1132                 case VBLK_CMP3:  result = ldm_parse_cmp3 (buf, len, vb); break;
1133                 case VBLK_DSK3:  result = ldm_parse_dsk3 (buf, len, vb); break;
1134                 case VBLK_DSK4:  result = ldm_parse_dsk4 (buf, len, vb); break;
1135                 case VBLK_DGR3:  result = ldm_parse_dgr3 (buf, len, vb); break;
1136                 case VBLK_DGR4:  result = ldm_parse_dgr4 (buf, len, vb); break;
1137                 case VBLK_PRT3:  result = ldm_parse_prt3 (buf, len, vb); break;
1138                 case VBLK_VOL5:  result = ldm_parse_vol5 (buf, len, vb); break;
1139         }
1140 
1141         if (result)
1142                 ldm_debug ("Parsed VBLK 0x%llx (type: 0x%02x) ok.",
1143                          (unsigned long long) vb->obj_id, vb->type);
1144         else
1145                 ldm_error ("Failed to parse VBLK 0x%llx (type: 0x%02x).",
1146                         (unsigned long long) vb->obj_id, vb->type);
1147 
1148         return result;
1149 }
1150 
1151 
1152 /**
1153  * ldm_ldmdb_add - Adds a raw VBLK entry to the ldmdb database
1154  * @data:  Raw VBLK to add to the database
1155  * @len:   Size of the raw VBLK
1156  * @ldb:   Cache of the database structures
1157  *
1158  * The VBLKs are sorted into categories.  Partitions are also sorted by offset.
1159  *
1160  * N.B.  This function does not check the validity of the VBLKs.
1161  *
1162  * Return:  'true'   The VBLK was added
1163  *          'false'  An error occurred
1164  */
1165 static bool ldm_ldmdb_add (u8 *data, int len, struct ldmdb *ldb)
1166 {
1167         struct vblk *vb;
1168         struct list_head *item;
1169 
1170         BUG_ON (!data || !ldb);
1171 
1172         vb = kmalloc (sizeof (*vb), GFP_KERNEL);
1173         if (!vb) {
1174                 ldm_crit ("Out of memory.");
1175                 return false;
1176         }
1177 
1178         if (!ldm_parse_vblk (data, len, vb)) {
1179                 kfree(vb);
1180                 return false;                   /* Already logged */
1181         }
1182 
1183         /* Put vblk into the correct list. */
1184         switch (vb->type) {
1185         case VBLK_DGR3:
1186         case VBLK_DGR4:
1187                 list_add (&vb->list, &ldb->v_dgrp);
1188                 break;
1189         case VBLK_DSK3:
1190         case VBLK_DSK4:
1191                 list_add (&vb->list, &ldb->v_disk);
1192                 break;
1193         case VBLK_VOL5:
1194                 list_add (&vb->list, &ldb->v_volu);
1195                 break;
1196         case VBLK_CMP3:
1197                 list_add (&vb->list, &ldb->v_comp);
1198                 break;
1199         case VBLK_PRT3:
1200                 /* Sort by the partition's start sector. */
1201                 list_for_each (item, &ldb->v_part) {
1202                         struct vblk *v = list_entry (item, struct vblk, list);
1203                         if ((v->vblk.part.disk_id == vb->vblk.part.disk_id) &&
1204                             (v->vblk.part.start > vb->vblk.part.start)) {
1205                                 list_add_tail (&vb->list, &v->list);
1206                                 return true;
1207                         }
1208                 }
1209                 list_add_tail (&vb->list, &ldb->v_part);
1210                 break;
1211         }
1212         return true;
1213 }
1214 
1215 /**
1216  * ldm_frag_add - Add a VBLK fragment to a list
1217  * @data:   Raw fragment to be added to the list
1218  * @size:   Size of the raw fragment
1219  * @frags:  Linked list of VBLK fragments
1220  *
1221  * Fragmented VBLKs may not be consecutive in the database, so they are placed
1222  * in a list so they can be pieced together later.
1223  *
1224  * Return:  'true'   Success, the VBLK was added to the list
1225  *          'false'  Error, a problem occurred
1226  */
1227 static bool ldm_frag_add (const u8 *data, int size, struct list_head *frags)
1228 {
1229         struct frag *f;
1230         struct list_head *item;
1231         int rec, num, group;
1232 
1233         BUG_ON (!data || !frags);
1234 
1235         if (size < 2 * VBLK_SIZE_HEAD) {
1236                 ldm_error("Value of size is to small.");
1237                 return false;
1238         }
1239 
1240         group = get_unaligned_be32(data + 0x08);
1241         rec   = get_unaligned_be16(data + 0x0C);
1242         num   = get_unaligned_be16(data + 0x0E);
1243         if ((num < 1) || (num > 4)) {
1244                 ldm_error ("A VBLK claims to have %d parts.", num);
1245                 return false;
1246         }
1247         if (rec >= num) {
1248                 ldm_error("REC value (%d) exceeds NUM value (%d)", rec, num);
1249                 return false;
1250         }
1251 
1252         list_for_each (item, frags) {
1253                 f = list_entry (item, struct frag, list);
1254                 if (f->group == group)
1255                         goto found;
1256         }
1257 
1258         f = kmalloc (sizeof (*f) + size*num, GFP_KERNEL);
1259         if (!f) {
1260                 ldm_crit ("Out of memory.");
1261                 return false;
1262         }
1263 
1264         f->group = group;
1265         f->num   = num;
1266         f->rec   = rec;
1267         f->map   = 0xFF << num;
1268 
1269         list_add_tail (&f->list, frags);
1270 found:
1271         if (rec >= f->num) {
1272                 ldm_error("REC value (%d) exceeds NUM value (%d)", rec, f->num);
1273                 return false;
1274         }
1275         if (f->map & (1 << rec)) {
1276                 ldm_error ("Duplicate VBLK, part %d.", rec);
1277                 f->map &= 0x7F;                 /* Mark the group as broken */
1278                 return false;
1279         }
1280         f->map |= (1 << rec);
1281         if (!rec)
1282                 memcpy(f->data, data, VBLK_SIZE_HEAD);
1283         data += VBLK_SIZE_HEAD;
1284         size -= VBLK_SIZE_HEAD;
1285         memcpy(f->data + VBLK_SIZE_HEAD + rec * size, data, size);
1286         return true;
1287 }
1288 
1289 /**
1290  * ldm_frag_free - Free a linked list of VBLK fragments
1291  * @list:  Linked list of fragments
1292  *
1293  * Free a linked list of VBLK fragments
1294  *
1295  * Return:  none
1296  */
1297 static void ldm_frag_free (struct list_head *list)
1298 {
1299         struct list_head *item, *tmp;
1300 
1301         BUG_ON (!list);
1302 
1303         list_for_each_safe (item, tmp, list)
1304                 kfree (list_entry (item, struct frag, list));
1305 }
1306 
1307 /**
1308  * ldm_frag_commit - Validate fragmented VBLKs and add them to the database
1309  * @frags:  Linked list of VBLK fragments
1310  * @ldb:    Cache of the database structures
1311  *
1312  * Now that all the fragmented VBLKs have been collected, they must be added to
1313  * the database for later use.
1314  *
1315  * Return:  'true'   All the fragments we added successfully
1316  *          'false'  One or more of the fragments we invalid
1317  */
1318 static bool ldm_frag_commit (struct list_head *frags, struct ldmdb *ldb)
1319 {
1320         struct frag *f;
1321         struct list_head *item;
1322 
1323         BUG_ON (!frags || !ldb);
1324 
1325         list_for_each (item, frags) {
1326                 f = list_entry (item, struct frag, list);
1327 
1328                 if (f->map != 0xFF) {
1329                         ldm_error ("VBLK group %d is incomplete (0x%02x).",
1330                                 f->group, f->map);
1331                         return false;
1332                 }
1333 
1334                 if (!ldm_ldmdb_add (f->data, f->num*ldb->vm.vblk_size, ldb))
1335                         return false;           /* Already logged */
1336         }
1337         return true;
1338 }
1339 
1340 /**
1341  * ldm_get_vblks - Read the on-disk database of VBLKs into memory
1342  * @state: Partition check state including device holding the LDM Database
1343  * @base:  Offset, into @state->bdev, of the database
1344  * @ldb:   Cache of the database structures
1345  *
1346  * To use the information from the VBLKs, they need to be read from the disk,
1347  * unpacked and validated.  We cache them in @ldb according to their type.
1348  *
1349  * Return:  'true'   All the VBLKs were read successfully
1350  *          'false'  An error occurred
1351  */
1352 static bool ldm_get_vblks(struct parsed_partitions *state, unsigned long base,
1353                           struct ldmdb *ldb)
1354 {
1355         int size, perbuf, skip, finish, s, v, recs;
1356         u8 *data = NULL;
1357         Sector sect;
1358         bool result = false;
1359         LIST_HEAD (frags);
1360 
1361         BUG_ON(!state || !ldb);
1362 
1363         size   = ldb->vm.vblk_size;
1364         perbuf = 512 / size;
1365         skip   = ldb->vm.vblk_offset >> 9;              /* Bytes to sectors */
1366         finish = (size * ldb->vm.last_vblk_seq) >> 9;
1367 
1368         for (s = skip; s < finish; s++) {               /* For each sector */
1369                 data = read_part_sector(state, base + OFF_VMDB + s, &sect);
1370                 if (!data) {
1371                         ldm_crit ("Disk read failed.");
1372                         goto out;
1373                 }
1374 
1375                 for (v = 0; v < perbuf; v++, data+=size) {  /* For each vblk */
1376                         if (MAGIC_VBLK != get_unaligned_be32(data)) {
1377                                 ldm_error ("Expected to find a VBLK.");
1378                                 goto out;
1379                         }
1380 
1381                         recs = get_unaligned_be16(data + 0x0E); /* Number of records */
1382                         if (recs == 1) {
1383                                 if (!ldm_ldmdb_add (data, size, ldb))
1384                                         goto out;       /* Already logged */
1385                         } else if (recs > 1) {
1386                                 if (!ldm_frag_add (data, size, &frags))
1387                                         goto out;       /* Already logged */
1388                         }
1389                         /* else Record is not in use, ignore it. */
1390                 }
1391                 put_dev_sector (sect);
1392                 data = NULL;
1393         }
1394 
1395         result = ldm_frag_commit (&frags, ldb); /* Failures, already logged */
1396 out:
1397         if (data)
1398                 put_dev_sector (sect);
1399         ldm_frag_free (&frags);
1400 
1401         return result;
1402 }
1403 
1404 /**
1405  * ldm_free_vblks - Free a linked list of vblk's
1406  * @lh:  Head of a linked list of struct vblk
1407  *
1408  * Free a list of vblk's and free the memory used to maintain the list.
1409  *
1410  * Return:  none
1411  */
1412 static void ldm_free_vblks (struct list_head *lh)
1413 {
1414         struct list_head *item, *tmp;
1415 
1416         BUG_ON (!lh);
1417 
1418         list_for_each_safe (item, tmp, lh)
1419                 kfree (list_entry (item, struct vblk, list));
1420 }
1421 
1422 
1423 /**
1424  * ldm_partition - Find out whether a device is a dynamic disk and handle it
1425  * @state: Partition check state including device holding the LDM Database
1426  *
1427  * This determines whether the device @bdev is a dynamic disk and if so creates
1428  * the partitions necessary in the gendisk structure pointed to by @hd.
1429  *
1430  * We create a dummy device 1, which contains the LDM database, and then create
1431  * each partition described by the LDM database in sequence as devices 2+. For
1432  * example, if the device is hda, we would have: hda1: LDM database, hda2, hda3,
1433  * and so on: the actual data containing partitions.
1434  *
1435  * Return:  1 Success, @state->bdev is a dynamic disk and we handled it
1436  *          0 Success, @state->bdev is not a dynamic disk
1437  *         -1 An error occurred before enough information had been read
1438  *            Or @state->bdev is a dynamic disk, but it may be corrupted
1439  */
1440 int ldm_partition(struct parsed_partitions *state)
1441 {
1442         struct ldmdb  *ldb;
1443         unsigned long base;
1444         int result = -1;
1445 
1446         BUG_ON(!state);
1447 
1448         /* Look for signs of a Dynamic Disk */
1449         if (!ldm_validate_partition_table(state))
1450                 return 0;
1451 
1452         ldb = kmalloc (sizeof (*ldb), GFP_KERNEL);
1453         if (!ldb) {
1454                 ldm_crit ("Out of memory.");
1455                 goto out;
1456         }
1457 
1458         /* Parse and check privheads. */
1459         if (!ldm_validate_privheads(state, &ldb->ph))
1460                 goto out;               /* Already logged */
1461 
1462         /* All further references are relative to base (database start). */
1463         base = ldb->ph.config_start;
1464 
1465         /* Parse and check tocs and vmdb. */
1466         if (!ldm_validate_tocblocks(state, base, ldb) ||
1467             !ldm_validate_vmdb(state, base, ldb))
1468                 goto out;               /* Already logged */
1469 
1470         /* Initialize vblk lists in ldmdb struct */
1471         INIT_LIST_HEAD (&ldb->v_dgrp);
1472         INIT_LIST_HEAD (&ldb->v_disk);
1473         INIT_LIST_HEAD (&ldb->v_volu);
1474         INIT_LIST_HEAD (&ldb->v_comp);
1475         INIT_LIST_HEAD (&ldb->v_part);
1476 
1477         if (!ldm_get_vblks(state, base, ldb)) {
1478                 ldm_crit ("Failed to read the VBLKs from the database.");
1479                 goto cleanup;
1480         }
1481 
1482         /* Finally, create the data partition devices. */
1483         if (ldm_create_data_partitions(state, ldb)) {
1484                 ldm_debug ("Parsed LDM database successfully.");
1485                 result = 1;
1486         }
1487         /* else Already logged */
1488 
1489 cleanup:
1490         ldm_free_vblks (&ldb->v_dgrp);
1491         ldm_free_vblks (&ldb->v_disk);
1492         ldm_free_vblks (&ldb->v_volu);
1493         ldm_free_vblks (&ldb->v_comp);
1494         ldm_free_vblks (&ldb->v_part);
1495 out:
1496         kfree (ldb);
1497         return result;
1498 }
1499 

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