1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * fs/partitions/msdos.c
4 *
5 * Code extracted from drivers/block/genhd.c
6 * Copyright (C) 1991-1998 Linus Torvalds
7 *
8 * Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug
9 * in the early extended-partition checks and added DM partitions
10 *
11 * Support for DiskManager v6.0x added by Mark Lord,
12 * with information provided by OnTrack. This now works for linux fdisk
13 * and LILO, as well as loadlin and bootln. Note that disks other than
14 * /dev/hda *must* have a "DOS" type 0x51 partition in the first slot (hda1).
15 *
16 * More flexible handling of extended partitions - aeb, 950831
17 *
18 * Check partition table on IDE disks for common CHS translations
19 *
20 * Re-organised Feb 1998 Russell King
21 *
22 * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il>
23 * updated by Marc Espie <Marc.Espie@openbsd.org>
24 *
25 * Unixware slices support by Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl>
26 * and Krzysztof G. Baranowski <kgb@knm.org.pl>
27 */
28 #include <linux/msdos_fs.h>
29 #include <linux/msdos_partition.h>
30
31 #include "check.h"
32 #include "efi.h"
33
34 /*
35 * Many architectures don't like unaligned accesses, while
36 * the nr_sects and start_sect partition table entries are
37 * at a 2 (mod 4) address.
38 */
39 #include <asm/unaligned.h>
40
nr_sects(struct msdos_partition * p)41 static inline sector_t nr_sects(struct msdos_partition *p)
42 {
43 return (sector_t)get_unaligned_le32(&p->nr_sects);
44 }
45
start_sect(struct msdos_partition * p)46 static inline sector_t start_sect(struct msdos_partition *p)
47 {
48 return (sector_t)get_unaligned_le32(&p->start_sect);
49 }
50
is_extended_partition(struct msdos_partition * p)51 static inline int is_extended_partition(struct msdos_partition *p)
52 {
53 return (p->sys_ind == DOS_EXTENDED_PARTITION ||
54 p->sys_ind == WIN98_EXTENDED_PARTITION ||
55 p->sys_ind == LINUX_EXTENDED_PARTITION);
56 }
57
58 #define MSDOS_LABEL_MAGIC1 0x55
59 #define MSDOS_LABEL_MAGIC2 0xAA
60
61 static inline int
msdos_magic_present(unsigned char * p)62 msdos_magic_present(unsigned char *p)
63 {
64 return (p[0] == MSDOS_LABEL_MAGIC1 && p[1] == MSDOS_LABEL_MAGIC2);
65 }
66
67 /* Value is EBCDIC 'IBMA' */
68 #define AIX_LABEL_MAGIC1 0xC9
69 #define AIX_LABEL_MAGIC2 0xC2
70 #define AIX_LABEL_MAGIC3 0xD4
71 #define AIX_LABEL_MAGIC4 0xC1
aix_magic_present(struct parsed_partitions * state,unsigned char * p)72 static int aix_magic_present(struct parsed_partitions *state, unsigned char *p)
73 {
74 struct msdos_partition *pt = (struct msdos_partition *) (p + 0x1be);
75 Sector sect;
76 unsigned char *d;
77 int slot, ret = 0;
78
79 if (!(p[0] == AIX_LABEL_MAGIC1 &&
80 p[1] == AIX_LABEL_MAGIC2 &&
81 p[2] == AIX_LABEL_MAGIC3 &&
82 p[3] == AIX_LABEL_MAGIC4))
83 return 0;
84
85 /*
86 * Assume the partition table is valid if Linux partitions exists.
87 * Note that old Solaris/x86 partitions use the same indicator as
88 * Linux swap partitions, so we consider that a Linux partition as
89 * well.
90 */
91 for (slot = 1; slot <= 4; slot++, pt++) {
92 if (pt->sys_ind == SOLARIS_X86_PARTITION ||
93 pt->sys_ind == LINUX_RAID_PARTITION ||
94 pt->sys_ind == LINUX_DATA_PARTITION ||
95 pt->sys_ind == LINUX_LVM_PARTITION ||
96 is_extended_partition(pt))
97 return 0;
98 }
99 d = read_part_sector(state, 7, §);
100 if (d) {
101 if (d[0] == '_' && d[1] == 'L' && d[2] == 'V' && d[3] == 'M')
102 ret = 1;
103 put_dev_sector(sect);
104 }
105 return ret;
106 }
107
set_info(struct parsed_partitions * state,int slot,u32 disksig)108 static void set_info(struct parsed_partitions *state, int slot,
109 u32 disksig)
110 {
111 struct partition_meta_info *info = &state->parts[slot].info;
112
113 snprintf(info->uuid, sizeof(info->uuid), "%08x-%02x", disksig,
114 slot);
115 info->volname[0] = 0;
116 state->parts[slot].has_info = true;
117 }
118
119 /*
120 * Create devices for each logical partition in an extended partition.
121 * The logical partitions form a linked list, with each entry being
122 * a partition table with two entries. The first entry
123 * is the real data partition (with a start relative to the partition
124 * table start). The second is a pointer to the next logical partition
125 * (with a start relative to the entire extended partition).
126 * We do not create a Linux partition for the partition tables, but
127 * only for the actual data partitions.
128 */
129
parse_extended(struct parsed_partitions * state,sector_t first_sector,sector_t first_size,u32 disksig)130 static void parse_extended(struct parsed_partitions *state,
131 sector_t first_sector, sector_t first_size,
132 u32 disksig)
133 {
134 struct msdos_partition *p;
135 Sector sect;
136 unsigned char *data;
137 sector_t this_sector, this_size;
138 sector_t sector_size = bdev_logical_block_size(state->bdev) / 512;
139 int loopct = 0; /* number of links followed
140 without finding a data partition */
141 int i;
142
143 this_sector = first_sector;
144 this_size = first_size;
145
146 while (1) {
147 if (++loopct > 100)
148 return;
149 if (state->next == state->limit)
150 return;
151 data = read_part_sector(state, this_sector, §);
152 if (!data)
153 return;
154
155 if (!msdos_magic_present(data + 510))
156 goto done;
157
158 p = (struct msdos_partition *) (data + 0x1be);
159
160 /*
161 * Usually, the first entry is the real data partition,
162 * the 2nd entry is the next extended partition, or empty,
163 * and the 3rd and 4th entries are unused.
164 * However, DRDOS sometimes has the extended partition as
165 * the first entry (when the data partition is empty),
166 * and OS/2 seems to use all four entries.
167 */
168
169 /*
170 * First process the data partition(s)
171 */
172 for (i = 0; i < 4; i++, p++) {
173 sector_t offs, size, next;
174
175 if (!nr_sects(p) || is_extended_partition(p))
176 continue;
177
178 /* Check the 3rd and 4th entries -
179 these sometimes contain random garbage */
180 offs = start_sect(p)*sector_size;
181 size = nr_sects(p)*sector_size;
182 next = this_sector + offs;
183 if (i >= 2) {
184 if (offs + size > this_size)
185 continue;
186 if (next < first_sector)
187 continue;
188 if (next + size > first_sector + first_size)
189 continue;
190 }
191
192 put_partition(state, state->next, next, size);
193 set_info(state, state->next, disksig);
194 if (p->sys_ind == LINUX_RAID_PARTITION)
195 state->parts[state->next].flags = ADDPART_FLAG_RAID;
196 loopct = 0;
197 if (++state->next == state->limit)
198 goto done;
199 }
200 /*
201 * Next, process the (first) extended partition, if present.
202 * (So far, there seems to be no reason to make
203 * parse_extended() recursive and allow a tree
204 * of extended partitions.)
205 * It should be a link to the next logical partition.
206 */
207 p -= 4;
208 for (i = 0; i < 4; i++, p++)
209 if (nr_sects(p) && is_extended_partition(p))
210 break;
211 if (i == 4)
212 goto done; /* nothing left to do */
213
214 this_sector = first_sector + start_sect(p) * sector_size;
215 this_size = nr_sects(p) * sector_size;
216 put_dev_sector(sect);
217 }
218 done:
219 put_dev_sector(sect);
220 }
221
222 #define SOLARIS_X86_NUMSLICE 16
223 #define SOLARIS_X86_VTOC_SANE (0x600DDEEEUL)
224
225 struct solaris_x86_slice {
226 __le16 s_tag; /* ID tag of partition */
227 __le16 s_flag; /* permission flags */
228 __le32 s_start; /* start sector no of partition */
229 __le32 s_size; /* # of blocks in partition */
230 };
231
232 struct solaris_x86_vtoc {
233 unsigned int v_bootinfo[3]; /* info needed by mboot */
234 __le32 v_sanity; /* to verify vtoc sanity */
235 __le32 v_version; /* layout version */
236 char v_volume[8]; /* volume name */
237 __le16 v_sectorsz; /* sector size in bytes */
238 __le16 v_nparts; /* number of partitions */
239 unsigned int v_reserved[10]; /* free space */
240 struct solaris_x86_slice
241 v_slice[SOLARIS_X86_NUMSLICE]; /* slice headers */
242 unsigned int timestamp[SOLARIS_X86_NUMSLICE]; /* timestamp */
243 char v_asciilabel[128]; /* for compatibility */
244 };
245
246 /* james@bpgc.com: Solaris has a nasty indicator: 0x82 which also
247 indicates linux swap. Be careful before believing this is Solaris. */
248
parse_solaris_x86(struct parsed_partitions * state,sector_t offset,sector_t size,int origin)249 static void parse_solaris_x86(struct parsed_partitions *state,
250 sector_t offset, sector_t size, int origin)
251 {
252 #ifdef CONFIG_SOLARIS_X86_PARTITION
253 Sector sect;
254 struct solaris_x86_vtoc *v;
255 int i;
256 short max_nparts;
257
258 v = read_part_sector(state, offset + 1, §);
259 if (!v)
260 return;
261 if (le32_to_cpu(v->v_sanity) != SOLARIS_X86_VTOC_SANE) {
262 put_dev_sector(sect);
263 return;
264 }
265 {
266 char tmp[1 + BDEVNAME_SIZE + 10 + 11 + 1];
267
268 snprintf(tmp, sizeof(tmp), " %s%d: <solaris:", state->name, origin);
269 strlcat(state->pp_buf, tmp, PAGE_SIZE);
270 }
271 if (le32_to_cpu(v->v_version) != 1) {
272 char tmp[64];
273
274 snprintf(tmp, sizeof(tmp), " cannot handle version %d vtoc>\n",
275 le32_to_cpu(v->v_version));
276 strlcat(state->pp_buf, tmp, PAGE_SIZE);
277 put_dev_sector(sect);
278 return;
279 }
280 /* Ensure we can handle previous case of VTOC with 8 entries gracefully */
281 max_nparts = le16_to_cpu(v->v_nparts) > 8 ? SOLARIS_X86_NUMSLICE : 8;
282 for (i = 0; i < max_nparts && state->next < state->limit; i++) {
283 struct solaris_x86_slice *s = &v->v_slice[i];
284 char tmp[3 + 10 + 1 + 1];
285
286 if (s->s_size == 0)
287 continue;
288 snprintf(tmp, sizeof(tmp), " [s%d]", i);
289 strlcat(state->pp_buf, tmp, PAGE_SIZE);
290 /* solaris partitions are relative to current MS-DOS
291 * one; must add the offset of the current partition */
292 put_partition(state, state->next++,
293 le32_to_cpu(s->s_start)+offset,
294 le32_to_cpu(s->s_size));
295 }
296 put_dev_sector(sect);
297 strlcat(state->pp_buf, " >\n", PAGE_SIZE);
298 #endif
299 }
300
301 /* check against BSD src/sys/sys/disklabel.h for consistency */
302 #define BSD_DISKMAGIC (0x82564557UL) /* The disk magic number */
303 #define BSD_MAXPARTITIONS 16
304 #define OPENBSD_MAXPARTITIONS 16
305 #define BSD_FS_UNUSED 0 /* disklabel unused partition entry ID */
306 struct bsd_disklabel {
307 __le32 d_magic; /* the magic number */
308 __s16 d_type; /* drive type */
309 __s16 d_subtype; /* controller/d_type specific */
310 char d_typename[16]; /* type name, e.g. "eagle" */
311 char d_packname[16]; /* pack identifier */
312 __u32 d_secsize; /* # of bytes per sector */
313 __u32 d_nsectors; /* # of data sectors per track */
314 __u32 d_ntracks; /* # of tracks per cylinder */
315 __u32 d_ncylinders; /* # of data cylinders per unit */
316 __u32 d_secpercyl; /* # of data sectors per cylinder */
317 __u32 d_secperunit; /* # of data sectors per unit */
318 __u16 d_sparespertrack; /* # of spare sectors per track */
319 __u16 d_sparespercyl; /* # of spare sectors per cylinder */
320 __u32 d_acylinders; /* # of alt. cylinders per unit */
321 __u16 d_rpm; /* rotational speed */
322 __u16 d_interleave; /* hardware sector interleave */
323 __u16 d_trackskew; /* sector 0 skew, per track */
324 __u16 d_cylskew; /* sector 0 skew, per cylinder */
325 __u32 d_headswitch; /* head switch time, usec */
326 __u32 d_trkseek; /* track-to-track seek, usec */
327 __u32 d_flags; /* generic flags */
328 #define NDDATA 5
329 __u32 d_drivedata[NDDATA]; /* drive-type specific information */
330 #define NSPARE 5
331 __u32 d_spare[NSPARE]; /* reserved for future use */
332 __le32 d_magic2; /* the magic number (again) */
333 __le16 d_checksum; /* xor of data incl. partitions */
334
335 /* filesystem and partition information: */
336 __le16 d_npartitions; /* number of partitions in following */
337 __le32 d_bbsize; /* size of boot area at sn0, bytes */
338 __le32 d_sbsize; /* max size of fs superblock, bytes */
339 struct bsd_partition { /* the partition table */
340 __le32 p_size; /* number of sectors in partition */
341 __le32 p_offset; /* starting sector */
342 __le32 p_fsize; /* filesystem basic fragment size */
343 __u8 p_fstype; /* filesystem type, see below */
344 __u8 p_frag; /* filesystem fragments per block */
345 __le16 p_cpg; /* filesystem cylinders per group */
346 } d_partitions[BSD_MAXPARTITIONS]; /* actually may be more */
347 };
348
349 #if defined(CONFIG_BSD_DISKLABEL)
350 /*
351 * Create devices for BSD partitions listed in a disklabel, under a
352 * dos-like partition. See parse_extended() for more information.
353 */
parse_bsd(struct parsed_partitions * state,sector_t offset,sector_t size,int origin,char * flavour,int max_partitions)354 static void parse_bsd(struct parsed_partitions *state,
355 sector_t offset, sector_t size, int origin, char *flavour,
356 int max_partitions)
357 {
358 Sector sect;
359 struct bsd_disklabel *l;
360 struct bsd_partition *p;
361 char tmp[64];
362
363 l = read_part_sector(state, offset + 1, §);
364 if (!l)
365 return;
366 if (le32_to_cpu(l->d_magic) != BSD_DISKMAGIC) {
367 put_dev_sector(sect);
368 return;
369 }
370
371 snprintf(tmp, sizeof(tmp), " %s%d: <%s:", state->name, origin, flavour);
372 strlcat(state->pp_buf, tmp, PAGE_SIZE);
373
374 if (le16_to_cpu(l->d_npartitions) < max_partitions)
375 max_partitions = le16_to_cpu(l->d_npartitions);
376 for (p = l->d_partitions; p - l->d_partitions < max_partitions; p++) {
377 sector_t bsd_start, bsd_size;
378
379 if (state->next == state->limit)
380 break;
381 if (p->p_fstype == BSD_FS_UNUSED)
382 continue;
383 bsd_start = le32_to_cpu(p->p_offset);
384 bsd_size = le32_to_cpu(p->p_size);
385 /* FreeBSD has relative offset if C partition offset is zero */
386 if (memcmp(flavour, "bsd\0", 4) == 0 &&
387 le32_to_cpu(l->d_partitions[2].p_offset) == 0)
388 bsd_start += offset;
389 if (offset == bsd_start && size == bsd_size)
390 /* full parent partition, we have it already */
391 continue;
392 if (offset > bsd_start || offset+size < bsd_start+bsd_size) {
393 strlcat(state->pp_buf, "bad subpartition - ignored\n", PAGE_SIZE);
394 continue;
395 }
396 put_partition(state, state->next++, bsd_start, bsd_size);
397 }
398 put_dev_sector(sect);
399 if (le16_to_cpu(l->d_npartitions) > max_partitions) {
400 snprintf(tmp, sizeof(tmp), " (ignored %d more)",
401 le16_to_cpu(l->d_npartitions) - max_partitions);
402 strlcat(state->pp_buf, tmp, PAGE_SIZE);
403 }
404 strlcat(state->pp_buf, " >\n", PAGE_SIZE);
405 }
406 #endif
407
parse_freebsd(struct parsed_partitions * state,sector_t offset,sector_t size,int origin)408 static void parse_freebsd(struct parsed_partitions *state,
409 sector_t offset, sector_t size, int origin)
410 {
411 #ifdef CONFIG_BSD_DISKLABEL
412 parse_bsd(state, offset, size, origin, "bsd", BSD_MAXPARTITIONS);
413 #endif
414 }
415
parse_netbsd(struct parsed_partitions * state,sector_t offset,sector_t size,int origin)416 static void parse_netbsd(struct parsed_partitions *state,
417 sector_t offset, sector_t size, int origin)
418 {
419 #ifdef CONFIG_BSD_DISKLABEL
420 parse_bsd(state, offset, size, origin, "netbsd", BSD_MAXPARTITIONS);
421 #endif
422 }
423
parse_openbsd(struct parsed_partitions * state,sector_t offset,sector_t size,int origin)424 static void parse_openbsd(struct parsed_partitions *state,
425 sector_t offset, sector_t size, int origin)
426 {
427 #ifdef CONFIG_BSD_DISKLABEL
428 parse_bsd(state, offset, size, origin, "openbsd",
429 OPENBSD_MAXPARTITIONS);
430 #endif
431 }
432
433 #define UNIXWARE_DISKMAGIC (0xCA5E600DUL) /* The disk magic number */
434 #define UNIXWARE_DISKMAGIC2 (0x600DDEEEUL) /* The slice table magic nr */
435 #define UNIXWARE_NUMSLICE 16
436 #define UNIXWARE_FS_UNUSED 0 /* Unused slice entry ID */
437
438 struct unixware_slice {
439 __le16 s_label; /* label */
440 __le16 s_flags; /* permission flags */
441 __le32 start_sect; /* starting sector */
442 __le32 nr_sects; /* number of sectors in slice */
443 };
444
445 struct unixware_disklabel {
446 __le32 d_type; /* drive type */
447 __le32 d_magic; /* the magic number */
448 __le32 d_version; /* version number */
449 char d_serial[12]; /* serial number of the device */
450 __le32 d_ncylinders; /* # of data cylinders per device */
451 __le32 d_ntracks; /* # of tracks per cylinder */
452 __le32 d_nsectors; /* # of data sectors per track */
453 __le32 d_secsize; /* # of bytes per sector */
454 __le32 d_part_start; /* # of first sector of this partition*/
455 __le32 d_unknown1[12]; /* ? */
456 __le32 d_alt_tbl; /* byte offset of alternate table */
457 __le32 d_alt_len; /* byte length of alternate table */
458 __le32 d_phys_cyl; /* # of physical cylinders per device */
459 __le32 d_phys_trk; /* # of physical tracks per cylinder */
460 __le32 d_phys_sec; /* # of physical sectors per track */
461 __le32 d_phys_bytes; /* # of physical bytes per sector */
462 __le32 d_unknown2; /* ? */
463 __le32 d_unknown3; /* ? */
464 __le32 d_pad[8]; /* pad */
465
466 struct unixware_vtoc {
467 __le32 v_magic; /* the magic number */
468 __le32 v_version; /* version number */
469 char v_name[8]; /* volume name */
470 __le16 v_nslices; /* # of slices */
471 __le16 v_unknown1; /* ? */
472 __le32 v_reserved[10]; /* reserved */
473 struct unixware_slice
474 v_slice[UNIXWARE_NUMSLICE]; /* slice headers */
475 } vtoc;
476 }; /* 408 */
477
478 /*
479 * Create devices for Unixware partitions listed in a disklabel, under a
480 * dos-like partition. See parse_extended() for more information.
481 */
parse_unixware(struct parsed_partitions * state,sector_t offset,sector_t size,int origin)482 static void parse_unixware(struct parsed_partitions *state,
483 sector_t offset, sector_t size, int origin)
484 {
485 #ifdef CONFIG_UNIXWARE_DISKLABEL
486 Sector sect;
487 struct unixware_disklabel *l;
488 struct unixware_slice *p;
489
490 l = read_part_sector(state, offset + 29, §);
491 if (!l)
492 return;
493 if (le32_to_cpu(l->d_magic) != UNIXWARE_DISKMAGIC ||
494 le32_to_cpu(l->vtoc.v_magic) != UNIXWARE_DISKMAGIC2) {
495 put_dev_sector(sect);
496 return;
497 }
498 {
499 char tmp[1 + BDEVNAME_SIZE + 10 + 12 + 1];
500
501 snprintf(tmp, sizeof(tmp), " %s%d: <unixware:", state->name, origin);
502 strlcat(state->pp_buf, tmp, PAGE_SIZE);
503 }
504 p = &l->vtoc.v_slice[1];
505 /* I omit the 0th slice as it is the same as whole disk. */
506 while (p - &l->vtoc.v_slice[0] < UNIXWARE_NUMSLICE) {
507 if (state->next == state->limit)
508 break;
509
510 if (p->s_label != UNIXWARE_FS_UNUSED)
511 put_partition(state, state->next++,
512 le32_to_cpu(p->start_sect),
513 le32_to_cpu(p->nr_sects));
514 p++;
515 }
516 put_dev_sector(sect);
517 strlcat(state->pp_buf, " >\n", PAGE_SIZE);
518 #endif
519 }
520
521 #define MINIX_NR_SUBPARTITIONS 4
522
523 /*
524 * Minix 2.0.0/2.0.2 subpartition support.
525 * Anand Krishnamurthy <anandk@wiproge.med.ge.com>
526 * Rajeev V. Pillai <rajeevvp@yahoo.com>
527 */
parse_minix(struct parsed_partitions * state,sector_t offset,sector_t size,int origin)528 static void parse_minix(struct parsed_partitions *state,
529 sector_t offset, sector_t size, int origin)
530 {
531 #ifdef CONFIG_MINIX_SUBPARTITION
532 Sector sect;
533 unsigned char *data;
534 struct msdos_partition *p;
535 int i;
536
537 data = read_part_sector(state, offset, §);
538 if (!data)
539 return;
540
541 p = (struct msdos_partition *)(data + 0x1be);
542
543 /* The first sector of a Minix partition can have either
544 * a secondary MBR describing its subpartitions, or
545 * the normal boot sector. */
546 if (msdos_magic_present(data + 510) &&
547 p->sys_ind == MINIX_PARTITION) { /* subpartition table present */
548 char tmp[1 + BDEVNAME_SIZE + 10 + 9 + 1];
549
550 snprintf(tmp, sizeof(tmp), " %s%d: <minix:", state->name, origin);
551 strlcat(state->pp_buf, tmp, PAGE_SIZE);
552 for (i = 0; i < MINIX_NR_SUBPARTITIONS; i++, p++) {
553 if (state->next == state->limit)
554 break;
555 /* add each partition in use */
556 if (p->sys_ind == MINIX_PARTITION)
557 put_partition(state, state->next++,
558 start_sect(p), nr_sects(p));
559 }
560 strlcat(state->pp_buf, " >\n", PAGE_SIZE);
561 }
562 put_dev_sector(sect);
563 #endif /* CONFIG_MINIX_SUBPARTITION */
564 }
565
566 static struct {
567 unsigned char id;
568 void (*parse)(struct parsed_partitions *, sector_t, sector_t, int);
569 } subtypes[] = {
570 {FREEBSD_PARTITION, parse_freebsd},
571 {NETBSD_PARTITION, parse_netbsd},
572 {OPENBSD_PARTITION, parse_openbsd},
573 {MINIX_PARTITION, parse_minix},
574 {UNIXWARE_PARTITION, parse_unixware},
575 {SOLARIS_X86_PARTITION, parse_solaris_x86},
576 {NEW_SOLARIS_X86_PARTITION, parse_solaris_x86},
577 {0, NULL},
578 };
579
msdos_partition(struct parsed_partitions * state)580 int msdos_partition(struct parsed_partitions *state)
581 {
582 sector_t sector_size = bdev_logical_block_size(state->bdev) / 512;
583 Sector sect;
584 unsigned char *data;
585 struct msdos_partition *p;
586 struct fat_boot_sector *fb;
587 int slot;
588 u32 disksig;
589
590 data = read_part_sector(state, 0, §);
591 if (!data)
592 return -1;
593
594 /*
595 * Note order! (some AIX disks, e.g. unbootable kind,
596 * have no MSDOS 55aa)
597 */
598 if (aix_magic_present(state, data)) {
599 put_dev_sector(sect);
600 #ifdef CONFIG_AIX_PARTITION
601 return aix_partition(state);
602 #else
603 strlcat(state->pp_buf, " [AIX]", PAGE_SIZE);
604 return 0;
605 #endif
606 }
607
608 if (!msdos_magic_present(data + 510)) {
609 put_dev_sector(sect);
610 return 0;
611 }
612
613 /*
614 * Now that the 55aa signature is present, this is probably
615 * either the boot sector of a FAT filesystem or a DOS-type
616 * partition table. Reject this in case the boot indicator
617 * is not 0 or 0x80.
618 */
619 p = (struct msdos_partition *) (data + 0x1be);
620 for (slot = 1; slot <= 4; slot++, p++) {
621 if (p->boot_ind != 0 && p->boot_ind != 0x80) {
622 /*
623 * Even without a valid boot inidicator value
624 * its still possible this is valid FAT filesystem
625 * without a partition table.
626 */
627 fb = (struct fat_boot_sector *) data;
628 if (slot == 1 && fb->reserved && fb->fats
629 && fat_valid_media(fb->media)) {
630 strlcat(state->pp_buf, "\n", PAGE_SIZE);
631 put_dev_sector(sect);
632 return 1;
633 } else {
634 put_dev_sector(sect);
635 return 0;
636 }
637 }
638 }
639
640 #ifdef CONFIG_EFI_PARTITION
641 p = (struct msdos_partition *) (data + 0x1be);
642 for (slot = 1 ; slot <= 4 ; slot++, p++) {
643 /* If this is an EFI GPT disk, msdos should ignore it. */
644 if (p->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT) {
645 put_dev_sector(sect);
646 return 0;
647 }
648 }
649 #endif
650 p = (struct msdos_partition *) (data + 0x1be);
651
652 disksig = le32_to_cpup((__le32 *)(data + 0x1b8));
653
654 /*
655 * Look for partitions in two passes:
656 * First find the primary and DOS-type extended partitions.
657 * On the second pass look inside *BSD, Unixware and Solaris partitions.
658 */
659
660 state->next = 5;
661 for (slot = 1 ; slot <= 4 ; slot++, p++) {
662 sector_t start = start_sect(p)*sector_size;
663 sector_t size = nr_sects(p)*sector_size;
664
665 if (!size)
666 continue;
667 if (is_extended_partition(p)) {
668 /*
669 * prevent someone doing mkfs or mkswap on an
670 * extended partition, but leave room for LILO
671 * FIXME: this uses one logical sector for > 512b
672 * sector, although it may not be enough/proper.
673 */
674 sector_t n = 2;
675
676 n = min(size, max(sector_size, n));
677 put_partition(state, slot, start, n);
678
679 strlcat(state->pp_buf, " <", PAGE_SIZE);
680 parse_extended(state, start, size, disksig);
681 strlcat(state->pp_buf, " >", PAGE_SIZE);
682 continue;
683 }
684 put_partition(state, slot, start, size);
685 set_info(state, slot, disksig);
686 if (p->sys_ind == LINUX_RAID_PARTITION)
687 state->parts[slot].flags = ADDPART_FLAG_RAID;
688 if (p->sys_ind == DM6_PARTITION)
689 strlcat(state->pp_buf, "[DM]", PAGE_SIZE);
690 if (p->sys_ind == EZD_PARTITION)
691 strlcat(state->pp_buf, "[EZD]", PAGE_SIZE);
692 }
693
694 strlcat(state->pp_buf, "\n", PAGE_SIZE);
695
696 /* second pass - output for each on a separate line */
697 p = (struct msdos_partition *) (0x1be + data);
698 for (slot = 1 ; slot <= 4 ; slot++, p++) {
699 unsigned char id = p->sys_ind;
700 int n;
701
702 if (!nr_sects(p))
703 continue;
704
705 for (n = 0; subtypes[n].parse && id != subtypes[n].id; n++)
706 ;
707
708 if (!subtypes[n].parse)
709 continue;
710 subtypes[n].parse(state, start_sect(p) * sector_size,
711 nr_sects(p) * sector_size, slot);
712 }
713 put_dev_sector(sect);
714 return 1;
715 }
716