1 /*
2 * GRUB -- GRand Unified Bootloader
3 * Copyright (C) 1999,2000,2001,2002,2003,2004 Free Software Foundation, Inc.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 */
19
20 /*
21 * Copyright 2010 Sun Microsystems, Inc. All rights reserved.
22 * Use is subject to license terms.
23 */
24
25 /*
26 * Copyright (c) 2012 by Delphix. All rights reserved.
27 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
28 */
29
30 /*
31 * The zfs plug-in routines for GRUB are:
32 *
33 * zfs_mount() - locates a valid uberblock of the root pool and reads
34 * in its MOS at the memory address MOS.
35 *
36 * zfs_open() - locates a plain file object by following the MOS
37 * and places its dnode at the memory address DNODE.
38 *
39 * zfs_read() - read in the data blocks pointed by the DNODE.
40 *
41 * ZFS_SCRATCH is used as a working area.
42 *
43 * (memory addr) MOS DNODE ZFS_SCRATCH
44 * | | |
45 * +-------V---------V----------V---------------+
46 * memory | | dnode | dnode | scratch |
47 * | | 512B | 512B | area |
48 * +--------------------------------------------+
49 */
50
51 #ifdef FSYS_ZFS
52
53 #include "shared.h"
54 #include "filesys.h"
55 #include "fsys_zfs.h"
56
57 /* cache for a file block of the currently zfs_open()-ed file */
58 static void *file_buf = NULL;
59 static uint64_t file_start = 0;
60 static uint64_t file_end = 0;
61
62 /* cache for a dnode block */
63 static dnode_phys_t *dnode_buf = NULL;
64 static dnode_phys_t *dnode_mdn = NULL;
65 static uint64_t dnode_start = 0;
66 static uint64_t dnode_end = 0;
67
68 static uint64_t pool_guid = 0;
69 static uberblock_t current_uberblock;
70 static char *stackbase;
71
72 decomp_entry_t decomp_table[ZIO_COMPRESS_FUNCTIONS] =
73 {
74 {"inherit", 0}, /* ZIO_COMPRESS_INHERIT */
75 {"on", lzjb_decompress}, /* ZIO_COMPRESS_ON */
76 {"off", 0}, /* ZIO_COMPRESS_OFF */
77 {"lzjb", lzjb_decompress}, /* ZIO_COMPRESS_LZJB */
78 {"empty", 0}, /* ZIO_COMPRESS_EMPTY */
79 {"gzip-1", 0}, /* ZIO_COMPRESS_GZIP_1 */
80 {"gzip-2", 0}, /* ZIO_COMPRESS_GZIP_2 */
81 {"gzip-3", 0}, /* ZIO_COMPRESS_GZIP_3 */
82 {"gzip-4", 0}, /* ZIO_COMPRESS_GZIP_4 */
83 {"gzip-5", 0}, /* ZIO_COMPRESS_GZIP_5 */
84 {"gzip-6", 0}, /* ZIO_COMPRESS_GZIP_6 */
85 {"gzip-7", 0}, /* ZIO_COMPRESS_GZIP_7 */
86 {"gzip-8", 0}, /* ZIO_COMPRESS_GZIP_8 */
87 {"gzip-9", 0}, /* ZIO_COMPRESS_GZIP_9 */
88 {"zle", 0}, /* ZIO_COMPRESS_ZLE */
89 {"lz4", lz4_decompress} /* ZIO_COMPRESS_LZ4 */
90 };
91
92 static int zio_read_data(blkptr_t *bp, void *buf, char *stack);
93
94 /*
95 * Our own version of bcmp().
96 */
97 static int
98 zfs_bcmp(const void *s1, const void *s2, size_t n)
99 {
100 const uchar_t *ps1 = s1;
101 const uchar_t *ps2 = s2;
102
103 if (s1 != s2 && n != 0) {
104 do {
105 if (*ps1++ != *ps2++)
106 return (1);
107 } while (--n != 0);
108 }
109
110 return (0);
111 }
112
113 /*
114 * Our own version of log2(). Same thing as highbit()-1.
115 */
116 static int
117 zfs_log2(uint64_t num)
118 {
119 int i = 0;
120
121 while (num > 1) {
122 i++;
123 num = num >> 1;
124 }
125
126 return (i);
127 }
128
129 /* Checksum Functions */
130 static void
131 zio_checksum_off(const void *buf, uint64_t size, zio_cksum_t *zcp)
132 {
133 ZIO_SET_CHECKSUM(zcp, 0, 0, 0, 0);
134 }
135
136 /* Checksum Table and Values */
137 zio_checksum_info_t zio_checksum_table[ZIO_CHECKSUM_FUNCTIONS] = {
138 {{NULL, NULL}, 0, 0, "inherit"},
139 {{NULL, NULL}, 0, 0, "on"},
140 {{zio_checksum_off, zio_checksum_off}, 0, 0, "off"},
141 {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 1, "label"},
142 {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 1, "gang_header"},
143 {{NULL, NULL}, 0, 0, "zilog"},
144 {{fletcher_2_native, fletcher_2_byteswap}, 0, 0, "fletcher2"},
145 {{fletcher_4_native, fletcher_4_byteswap}, 1, 0, "fletcher4"},
146 {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 0, "SHA256"},
147 {{NULL, NULL}, 0, 0, "zilog2"},
148 };
149
150 /*
151 * zio_checksum_verify: Provides support for checksum verification.
152 *
153 * Fletcher2, Fletcher4, and SHA256 are supported.
154 *
155 * Return:
156 * -1 = Failure
157 * 0 = Success
158 */
159 static int
160 zio_checksum_verify(blkptr_t *bp, char *data, int size)
161 {
162 zio_cksum_t zc = bp->blk_cksum;
163 uint32_t checksum = BP_GET_CHECKSUM(bp);
164 int byteswap = BP_SHOULD_BYTESWAP(bp);
165 zio_eck_t *zec = (zio_eck_t *)(data + size) - 1;
166 zio_checksum_info_t *ci = &zio_checksum_table[checksum];
167 zio_cksum_t actual_cksum, expected_cksum;
168
169 /* byteswap is not supported */
170 if (byteswap)
171 return (-1);
172
173 if (checksum >= ZIO_CHECKSUM_FUNCTIONS || ci->ci_func[0] == NULL)
174 return (-1);
175
176 if (ci->ci_eck) {
177 expected_cksum = zec->zec_cksum;
178 zec->zec_cksum = zc;
179 ci->ci_func[0](data, size, &actual_cksum);
180 zec->zec_cksum = expected_cksum;
181 zc = expected_cksum;
182
183 } else {
184 ci->ci_func[byteswap](data, size, &actual_cksum);
185 }
186
187 if ((actual_cksum.zc_word[0] - zc.zc_word[0]) |
188 (actual_cksum.zc_word[1] - zc.zc_word[1]) |
189 (actual_cksum.zc_word[2] - zc.zc_word[2]) |
190 (actual_cksum.zc_word[3] - zc.zc_word[3]))
191 return (-1);
192
193 return (0);
194 }
195
196 /*
197 * vdev_label_start returns the physical disk offset (in bytes) of
198 * label "l".
199 */
200 static uint64_t
201 vdev_label_start(uint64_t psize, int l)
202 {
203 return (l * sizeof (vdev_label_t) + (l < VDEV_LABELS / 2 ?
204 0 : psize - VDEV_LABELS * sizeof (vdev_label_t)));
205 }
206
207 /*
208 * vdev_uberblock_compare takes two uberblock structures and returns an integer
209 * indicating the more recent of the two.
210 * Return Value = 1 if ub2 is more recent
211 * Return Value = -1 if ub1 is more recent
212 * The most recent uberblock is determined using its transaction number and
213 * timestamp. The uberblock with the highest transaction number is
214 * considered "newer". If the transaction numbers of the two blocks match, the
215 * timestamps are compared to determine the "newer" of the two.
216 */
217 static int
218 vdev_uberblock_compare(uberblock_t *ub1, uberblock_t *ub2)
219 {
220 if (ub1->ub_txg < ub2->ub_txg)
221 return (-1);
222 if (ub1->ub_txg > ub2->ub_txg)
223 return (1);
224
225 if (ub1->ub_timestamp < ub2->ub_timestamp)
226 return (-1);
227 if (ub1->ub_timestamp > ub2->ub_timestamp)
228 return (1);
229
230 return (0);
231 }
232
233 /*
234 * Three pieces of information are needed to verify an uberblock: the magic
235 * number, the version number, and the checksum.
236 *
237 * Return:
238 * 0 - Success
239 * -1 - Failure
240 */
241 static int
242 uberblock_verify(uberblock_t *uber, uint64_t ub_size, uint64_t offset)
243 {
244 blkptr_t bp;
245
246 BP_ZERO(&bp);
247 BP_SET_CHECKSUM(&bp, ZIO_CHECKSUM_LABEL);
248 BP_SET_BYTEORDER(&bp, ZFS_HOST_BYTEORDER);
249 ZIO_SET_CHECKSUM(&bp.blk_cksum, offset, 0, 0, 0);
250
251 if (zio_checksum_verify(&bp, (char *)uber, ub_size) != 0)
252 return (-1);
253
254 if (uber->ub_magic == UBERBLOCK_MAGIC &&
255 SPA_VERSION_IS_SUPPORTED(uber->ub_version))
256 return (0);
257
258 return (-1);
259 }
260
261 /*
262 * Find the best uberblock.
263 * Return:
264 * Success - Pointer to the best uberblock.
265 * Failure - NULL
266 */
267 static uberblock_t *
268 find_bestub(char *ub_array, uint64_t ashift, uint64_t sector)
269 {
270 uberblock_t *ubbest = NULL;
271 uberblock_t *ubnext;
272 uint64_t offset, ub_size;
273 int i;
274
275 ub_size = VDEV_UBERBLOCK_SIZE(ashift);
276
277 for (i = 0; i < VDEV_UBERBLOCK_COUNT(ashift); i++) {
278 ubnext = (uberblock_t *)ub_array;
279 ub_array += ub_size;
280 offset = (sector << SPA_MINBLOCKSHIFT) +
281 VDEV_UBERBLOCK_OFFSET(ashift, i);
282
283 if (uberblock_verify(ubnext, ub_size, offset) != 0)
284 continue;
285
286 if (ubbest == NULL ||
287 vdev_uberblock_compare(ubnext, ubbest) > 0)
288 ubbest = ubnext;
289 }
290
291 return (ubbest);
292 }
293
294 /*
295 * Read a block of data based on the gang block address dva,
296 * and put its data in buf.
297 *
298 * Return:
299 * 0 - success
300 * 1 - failure
301 */
302 static int
303 zio_read_gang(blkptr_t *bp, dva_t *dva, void *buf, char *stack)
304 {
305 zio_gbh_phys_t *zio_gb;
306 uint64_t offset, sector;
307 blkptr_t tmpbp;
308 int i;
309
310 zio_gb = (zio_gbh_phys_t *)stack;
311 stack += SPA_GANGBLOCKSIZE;
312 offset = DVA_GET_OFFSET(dva);
313 sector = DVA_OFFSET_TO_PHYS_SECTOR(offset);
314
315 /* read in the gang block header */
316 if (devread(sector, 0, SPA_GANGBLOCKSIZE, (char *)zio_gb) == 0) {
317 grub_printf("failed to read in a gang block header\n");
318 return (1);
319 }
320
321 /* self checksuming the gang block header */
322 BP_ZERO(&tmpbp);
323 BP_SET_CHECKSUM(&tmpbp, ZIO_CHECKSUM_GANG_HEADER);
324 BP_SET_BYTEORDER(&tmpbp, ZFS_HOST_BYTEORDER);
325 ZIO_SET_CHECKSUM(&tmpbp.blk_cksum, DVA_GET_VDEV(dva),
326 DVA_GET_OFFSET(dva), bp->blk_birth, 0);
327 if (zio_checksum_verify(&tmpbp, (char *)zio_gb, SPA_GANGBLOCKSIZE)) {
328 grub_printf("failed to checksum a gang block header\n");
329 return (1);
330 }
331
332 for (i = 0; i < SPA_GBH_NBLKPTRS; i++) {
333 if (zio_gb->zg_blkptr[i].blk_birth == 0)
334 continue;
335
336 if (zio_read_data(&zio_gb->zg_blkptr[i], buf, stack))
337 return (1);
338 buf += BP_GET_PSIZE(&zio_gb->zg_blkptr[i]);
339 }
340
341 return (0);
342 }
343
344 /*
345 * Read in a block of raw data to buf.
346 *
347 * Return:
348 * 0 - success
349 * 1 - failure
350 */
351 static int
352 zio_read_data(blkptr_t *bp, void *buf, char *stack)
353 {
354 int i, psize;
355
356 psize = BP_GET_PSIZE(bp);
357
358 /* pick a good dva from the block pointer */
359 for (i = 0; i < SPA_DVAS_PER_BP; i++) {
360 uint64_t offset, sector;
361
362 if (bp->blk_dva[i].dva_word[0] == 0 &&
363 bp->blk_dva[i].dva_word[1] == 0)
364 continue;
365
366 if (DVA_GET_GANG(&bp->blk_dva[i])) {
367 if (zio_read_gang(bp, &bp->blk_dva[i], buf, stack) == 0)
368 return (0);
369 } else {
370 /* read in a data block */
371 offset = DVA_GET_OFFSET(&bp->blk_dva[i]);
372 sector = DVA_OFFSET_TO_PHYS_SECTOR(offset);
373 if (devread(sector, 0, psize, buf) != 0)
374 return (0);
375 }
376 }
377
378 return (1);
379 }
380
381 /*
382 * Read in a block of data, verify its checksum, decompress if needed,
383 * and put the uncompressed data in buf.
384 *
385 * Return:
386 * 0 - success
387 * errnum - failure
388 */
389 static int
390 zio_read(blkptr_t *bp, void *buf, char *stack)
391 {
392 int lsize, psize, comp;
393 char *retbuf;
394
395 comp = BP_GET_COMPRESS(bp);
396 lsize = BP_GET_LSIZE(bp);
397 psize = BP_GET_PSIZE(bp);
398
399 if ((unsigned int)comp >= ZIO_COMPRESS_FUNCTIONS ||
400 (comp != ZIO_COMPRESS_OFF &&
401 decomp_table[comp].decomp_func == NULL)) {
402 grub_printf("compression algorithm not supported\n");
403 return (ERR_FSYS_CORRUPT);
404 }
405
406 if ((char *)buf < stack && ((char *)buf) + lsize > stack) {
407 grub_printf("not enough memory allocated\n");
408 return (ERR_WONT_FIT);
409 }
410
411 retbuf = buf;
412 if (comp != ZIO_COMPRESS_OFF) {
413 buf = stack;
414 stack += psize;
415 }
416
417 if (zio_read_data(bp, buf, stack) != 0) {
418 grub_printf("zio_read_data failed\n");
419 return (ERR_FSYS_CORRUPT);
420 }
421
422 if (zio_checksum_verify(bp, buf, psize) != 0) {
423 grub_printf("checksum verification failed\n");
424 return (ERR_FSYS_CORRUPT);
425 }
426
427 if (comp != ZIO_COMPRESS_OFF) {
428 if (decomp_table[comp].decomp_func(buf, retbuf, psize,
429 lsize) != 0) {
430 grub_printf("zio_read decompression failed\n");
431 return (ERR_FSYS_CORRUPT);
432 }
433 }
434
435 return (0);
436 }
437
438 /*
439 * Get the block from a block id.
440 * push the block onto the stack.
441 *
442 * Return:
443 * 0 - success
444 * errnum - failure
445 */
446 static int
447 dmu_read(dnode_phys_t *dn, uint64_t blkid, void *buf, char *stack)
448 {
449 int idx, level;
450 blkptr_t *bp_array = dn->dn_blkptr;
451 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
452 blkptr_t *bp, *tmpbuf;
453
454 bp = (blkptr_t *)stack;
455 stack += sizeof (blkptr_t);
456
457 tmpbuf = (blkptr_t *)stack;
458 stack += 1<<dn->dn_indblkshift;
459
460 for (level = dn->dn_nlevels - 1; level >= 0; level--) {
461 idx = (blkid >> (epbs * level)) & ((1<<epbs)-1);
462 *bp = bp_array[idx];
463 if (level == 0)
464 tmpbuf = buf;
465 if (BP_IS_HOLE(bp)) {
466 grub_memset(buf, 0,
467 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
468 break;
469 } else if (errnum = zio_read(bp, tmpbuf, stack)) {
470 return (errnum);
471 }
472
473 bp_array = tmpbuf;
474 }
475
476 return (0);
477 }
478
479 /*
480 * mzap_lookup: Looks up property described by "name" and returns the value
481 * in "value".
482 *
483 * Return:
484 * 0 - success
485 * errnum - failure
486 */
487 static int
488 mzap_lookup(mzap_phys_t *zapobj, int objsize, const char *name,
489 uint64_t *value)
490 {
491 int i, chunks;
492 mzap_ent_phys_t *mzap_ent = zapobj->mz_chunk;
493
494 chunks = objsize / MZAP_ENT_LEN - 1;
495 for (i = 0; i < chunks; i++) {
496 if (grub_strcmp(mzap_ent[i].mze_name, name) == 0) {
497 *value = mzap_ent[i].mze_value;
498 return (0);
499 }
500 }
501
502 return (ERR_FSYS_CORRUPT);
503 }
504
505 static uint64_t
506 zap_hash(uint64_t salt, const char *name)
507 {
508 static uint64_t table[256];
509 const uint8_t *cp;
510 uint8_t c;
511 uint64_t crc = salt;
512
513 if (table[128] == 0) {
514 uint64_t *ct;
515 int i, j;
516 for (i = 0; i < 256; i++) {
517 for (ct = table + i, *ct = i, j = 8; j > 0; j--)
518 *ct = (*ct >> 1) ^ (-(*ct & 1) &
519 ZFS_CRC64_POLY);
520 }
521 }
522
523 if (crc == 0 || table[128] != ZFS_CRC64_POLY) {
524 errnum = ERR_FSYS_CORRUPT;
525 return (0);
526 }
527
528 for (cp = (const uint8_t *)name; (c = *cp) != '\0'; cp++)
529 crc = (crc >> 8) ^ table[(crc ^ c) & 0xFF];
530
531 /*
532 * Only use 28 bits, since we need 4 bits in the cookie for the
533 * collision differentiator. We MUST use the high bits, since
534 * those are the ones that we first pay attention to when
535 * choosing the bucket.
536 */
537 crc &= ~((1ULL << (64 - 28)) - 1);
538
539 return (crc);
540 }
541
542 /*
543 * Only to be used on 8-bit arrays.
544 * array_len is actual len in bytes (not encoded le_value_length).
545 * buf is null-terminated.
546 */
547 static int
548 zap_leaf_array_equal(zap_leaf_phys_t *l, int blksft, int chunk,
549 int array_len, const char *buf)
550 {
551 int bseen = 0;
552
553 while (bseen < array_len) {
554 struct zap_leaf_array *la =
555 &ZAP_LEAF_CHUNK(l, blksft, chunk).l_array;
556 int toread = MIN(array_len - bseen, ZAP_LEAF_ARRAY_BYTES);
557
558 if (chunk >= ZAP_LEAF_NUMCHUNKS(blksft))
559 return (0);
560
561 if (zfs_bcmp(la->la_array, buf + bseen, toread) != 0)
562 break;
563 chunk = la->la_next;
564 bseen += toread;
565 }
566 return (bseen == array_len);
567 }
568
569 /*
570 * Given a zap_leaf_phys_t, walk thru the zap leaf chunks to get the
571 * value for the property "name".
572 *
573 * Return:
574 * 0 - success
575 * errnum - failure
576 */
577 static int
578 zap_leaf_lookup(zap_leaf_phys_t *l, int blksft, uint64_t h,
579 const char *name, uint64_t *value)
580 {
581 uint16_t chunk;
582 struct zap_leaf_entry *le;
583
584 /* Verify if this is a valid leaf block */
585 if (l->l_hdr.lh_block_type != ZBT_LEAF)
586 return (ERR_FSYS_CORRUPT);
587 if (l->l_hdr.lh_magic != ZAP_LEAF_MAGIC)
588 return (ERR_FSYS_CORRUPT);
589
590 for (chunk = l->l_hash[LEAF_HASH(blksft, h)];
591 chunk != CHAIN_END; chunk = le->le_next) {
592
593 if (chunk >= ZAP_LEAF_NUMCHUNKS(blksft))
594 return (ERR_FSYS_CORRUPT);
595
596 le = ZAP_LEAF_ENTRY(l, blksft, chunk);
597
598 /* Verify the chunk entry */
599 if (le->le_type != ZAP_CHUNK_ENTRY)
600 return (ERR_FSYS_CORRUPT);
601
602 if (le->le_hash != h)
603 continue;
604
605 if (zap_leaf_array_equal(l, blksft, le->le_name_chunk,
606 le->le_name_length, name)) {
607
608 struct zap_leaf_array *la;
609 uint8_t *ip;
610
611 if (le->le_int_size != 8 || le->le_value_length != 1)
612 return (ERR_FSYS_CORRUPT);
613
614 /* get the uint64_t property value */
615 la = &ZAP_LEAF_CHUNK(l, blksft,
616 le->le_value_chunk).l_array;
617 ip = la->la_array;
618
619 *value = (uint64_t)ip[0] << 56 | (uint64_t)ip[1] << 48 |
620 (uint64_t)ip[2] << 40 | (uint64_t)ip[3] << 32 |
621 (uint64_t)ip[4] << 24 | (uint64_t)ip[5] << 16 |
622 (uint64_t)ip[6] << 8 | (uint64_t)ip[7];
623
624 return (0);
625 }
626 }
627
628 return (ERR_FSYS_CORRUPT);
629 }
630
631 /*
632 * Fat ZAP lookup
633 *
634 * Return:
635 * 0 - success
636 * errnum - failure
637 */
638 static int
639 fzap_lookup(dnode_phys_t *zap_dnode, zap_phys_t *zap,
640 const char *name, uint64_t *value, char *stack)
641 {
642 zap_leaf_phys_t *l;
643 uint64_t hash, idx, blkid;
644 int blksft = zfs_log2(zap_dnode->dn_datablkszsec << DNODE_SHIFT);
645
646 /* Verify if this is a fat zap header block */
647 if (zap->zap_magic != (uint64_t)ZAP_MAGIC ||
648 zap->zap_flags != 0)
649 return (ERR_FSYS_CORRUPT);
650
651 hash = zap_hash(zap->zap_salt, name);
652 if (errnum)
653 return (errnum);
654
655 /* get block id from index */
656 if (zap->zap_ptrtbl.zt_numblks != 0) {
657 /* external pointer tables not supported */
658 return (ERR_FSYS_CORRUPT);
659 }
660 idx = ZAP_HASH_IDX(hash, zap->zap_ptrtbl.zt_shift);
661 blkid = ((uint64_t *)zap)[idx + (1<<(blksft-3-1))];
662
663 /* Get the leaf block */
664 l = (zap_leaf_phys_t *)stack;
665 stack += 1<<blksft;
666 if ((1<<blksft) < sizeof (zap_leaf_phys_t))
667 return (ERR_FSYS_CORRUPT);
668 if (errnum = dmu_read(zap_dnode, blkid, l, stack))
669 return (errnum);
670
671 return (zap_leaf_lookup(l, blksft, hash, name, value));
672 }
673
674 /*
675 * Read in the data of a zap object and find the value for a matching
676 * property name.
677 *
678 * Return:
679 * 0 - success
680 * errnum - failure
681 */
682 static int
683 zap_lookup(dnode_phys_t *zap_dnode, const char *name, uint64_t *val,
684 char *stack)
685 {
686 uint64_t block_type;
687 int size;
688 void *zapbuf;
689
690 /* Read in the first block of the zap object data. */
691 zapbuf = stack;
692 size = zap_dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT;
693 stack += size;
694
695 if ((errnum = dmu_read(zap_dnode, 0, zapbuf, stack)) != 0)
696 return (errnum);
697
698 block_type = *((uint64_t *)zapbuf);
699
700 if (block_type == ZBT_MICRO) {
701 return (mzap_lookup(zapbuf, size, name, val));
702 } else if (block_type == ZBT_HEADER) {
703 /* this is a fat zap */
704 return (fzap_lookup(zap_dnode, zapbuf, name,
705 val, stack));
706 }
707
708 return (ERR_FSYS_CORRUPT);
709 }
710
711 typedef struct zap_attribute {
712 int za_integer_length;
713 uint64_t za_num_integers;
714 uint64_t za_first_integer;
715 char *za_name;
716 } zap_attribute_t;
717
718 typedef int (zap_cb_t)(zap_attribute_t *za, void *arg, char *stack);
719
720 static int
721 zap_iterate(dnode_phys_t *zap_dnode, zap_cb_t *cb, void *arg, char *stack)
722 {
723 uint32_t size = zap_dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT;
724 zap_attribute_t za;
725 int i;
726 mzap_phys_t *mzp = (mzap_phys_t *)stack;
727 stack += size;
728
729 if ((errnum = dmu_read(zap_dnode, 0, mzp, stack)) != 0)
730 return (errnum);
731
732 /*
733 * Iteration over fatzap objects has not yet been implemented.
734 * If we encounter a pool in which there are more features for
735 * read than can fit inside a microzap (i.e., more than 2048
736 * features for read), we can add support for fatzap iteration.
737 * For now, fail.
738 */
739 if (mzp->mz_block_type != ZBT_MICRO) {
740 grub_printf("feature information stored in fatzap, pool "
741 "version not supported\n");
742 return (1);
743 }
744
745 za.za_integer_length = 8;
746 za.za_num_integers = 1;
747 for (i = 0; i < size / MZAP_ENT_LEN - 1; i++) {
748 mzap_ent_phys_t *mzep = &mzp->mz_chunk[i];
749 int err;
750
751 za.za_first_integer = mzep->mze_value;
752 za.za_name = mzep->mze_name;
753 err = cb(&za, arg, stack);
754 if (err != 0)
755 return (err);
756 }
757
758 return (0);
759 }
760
761 /*
762 * Get the dnode of an object number from the metadnode of an object set.
763 *
764 * Input
765 * mdn - metadnode to get the object dnode
766 * objnum - object number for the object dnode
767 * buf - data buffer that holds the returning dnode
768 * stack - scratch area
769 *
770 * Return:
771 * 0 - success
772 * errnum - failure
773 */
774 static int
775 dnode_get(dnode_phys_t *mdn, uint64_t objnum, uint8_t type, dnode_phys_t *buf,
776 char *stack)
777 {
778 uint64_t blkid, blksz; /* the block id this object dnode is in */
779 int epbs; /* shift of number of dnodes in a block */
780 int idx; /* index within a block */
781 dnode_phys_t *dnbuf;
782
783 blksz = mdn->dn_datablkszsec << SPA_MINBLOCKSHIFT;
784 epbs = zfs_log2(blksz) - DNODE_SHIFT;
785 blkid = objnum >> epbs;
786 idx = objnum & ((1<<epbs)-1);
787
788 if (dnode_buf != NULL && dnode_mdn == mdn &&
789 objnum >= dnode_start && objnum < dnode_end) {
790 grub_memmove(buf, &dnode_buf[idx], DNODE_SIZE);
791 VERIFY_DN_TYPE(buf, type);
792 return (0);
793 }
794
795 if (dnode_buf && blksz == 1<<DNODE_BLOCK_SHIFT) {
796 dnbuf = dnode_buf;
797 dnode_mdn = mdn;
798 dnode_start = blkid << epbs;
799 dnode_end = (blkid + 1) << epbs;
800 } else {
801 dnbuf = (dnode_phys_t *)stack;
802 stack += blksz;
803 }
804
805 if (errnum = dmu_read(mdn, blkid, (char *)dnbuf, stack))
806 return (errnum);
807
808 grub_memmove(buf, &dnbuf[idx], DNODE_SIZE);
809 VERIFY_DN_TYPE(buf, type);
810
811 return (0);
812 }
813
814 /*
815 * Check if this is a special file that resides at the top
816 * dataset of the pool. Currently this is the GRUB menu,
817 * boot signature and boot signature backup.
818 * str starts with '/'.
819 */
820 static int
821 is_top_dataset_file(char *str)
822 {
823 char *tptr;
824
825 if ((tptr = grub_strstr(str, "menu.lst")) &&
826 (tptr[8] == '\0' || tptr[8] == ' ') &&
827 *(tptr-1) == '/')
828 return (1);
829
830 if (grub_strncmp(str, BOOTSIGN_DIR"/",
831 grub_strlen(BOOTSIGN_DIR) + 1) == 0)
832 return (1);
833
834 if (grub_strcmp(str, BOOTSIGN_BACKUP) == 0)
835 return (1);
836
837 return (0);
838 }
839
840 static int
841 check_feature(zap_attribute_t *za, void *arg, char *stack)
842 {
843 const char **names = arg;
844 int i;
845
846 if (za->za_first_integer == 0)
847 return (0);
848
849 for (i = 0; names[i] != NULL; i++) {
850 if (grub_strcmp(za->za_name, names[i]) == 0) {
851 return (0);
852 }
853 }
854 grub_printf("missing feature for read '%s'\n", za->za_name);
855 return (ERR_NEWER_VERSION);
856 }
857
858 /*
859 * Get the file dnode for a given file name where mdn is the meta dnode
860 * for this ZFS object set. When found, place the file dnode in dn.
861 * The 'path' argument will be mangled.
862 *
863 * Return:
864 * 0 - success
865 * errnum - failure
866 */
867 static int
868 dnode_get_path(dnode_phys_t *mdn, char *path, dnode_phys_t *dn,
869 char *stack)
870 {
871 uint64_t objnum, version;
872 char *cname, ch;
873
874 if (errnum = dnode_get(mdn, MASTER_NODE_OBJ, DMU_OT_MASTER_NODE,
875 dn, stack))
876 return (errnum);
877
878 if (errnum = zap_lookup(dn, ZPL_VERSION_STR, &version, stack))
879 return (errnum);
880 if (version > ZPL_VERSION)
881 return (-1);
882
883 if (errnum = zap_lookup(dn, ZFS_ROOT_OBJ, &objnum, stack))
884 return (errnum);
885
886 if (errnum = dnode_get(mdn, objnum, DMU_OT_DIRECTORY_CONTENTS,
887 dn, stack))
888 return (errnum);
889
890 /* skip leading slashes */
891 while (*path == '/')
892 path++;
893
894 while (*path && !grub_isspace(*path)) {
895
896 /* get the next component name */
897 cname = path;
898 while (*path && !grub_isspace(*path) && *path != '/')
899 path++;
900 ch = *path;
901 *path = 0; /* ensure null termination */
902
903 if (errnum = zap_lookup(dn, cname, &objnum, stack))
904 return (errnum);
905
906 objnum = ZFS_DIRENT_OBJ(objnum);
907 if (errnum = dnode_get(mdn, objnum, 0, dn, stack))
908 return (errnum);
909
910 *path = ch;
911 while (*path == '/')
912 path++;
913 }
914
915 /* We found the dnode for this file. Verify if it is a plain file. */
916 VERIFY_DN_TYPE(dn, DMU_OT_PLAIN_FILE_CONTENTS);
917
918 return (0);
919 }
920
921 /*
922 * Get the default 'bootfs' property value from the rootpool.
923 *
924 * Return:
925 * 0 - success
926 * errnum -failure
927 */
928 static int
929 get_default_bootfsobj(dnode_phys_t *mosmdn, uint64_t *obj, char *stack)
930 {
931 uint64_t objnum = 0;
932 dnode_phys_t *dn = (dnode_phys_t *)stack;
933 stack += DNODE_SIZE;
934
935 if (errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT,
936 DMU_OT_OBJECT_DIRECTORY, dn, stack))
937 return (errnum);
938
939 /*
940 * find the object number for 'pool_props', and get the dnode
941 * of the 'pool_props'.
942 */
943 if (zap_lookup(dn, DMU_POOL_PROPS, &objnum, stack))
944 return (ERR_FILESYSTEM_NOT_FOUND);
945
946 if (errnum = dnode_get(mosmdn, objnum, DMU_OT_POOL_PROPS, dn, stack))
947 return (errnum);
948
949 if (zap_lookup(dn, ZPOOL_PROP_BOOTFS, &objnum, stack))
950 return (ERR_FILESYSTEM_NOT_FOUND);
951
952 if (!objnum)
953 return (ERR_FILESYSTEM_NOT_FOUND);
954
955 *obj = objnum;
956 return (0);
957 }
958
959 /*
960 * List of pool features that the grub implementation of ZFS supports for
961 * read. Note that features that are only required for write do not need
962 * to be listed here since grub opens pools in read-only mode.
963 */
964 static const char *spa_feature_names[] = {
965 "org.illumos:lz4_compress",
966 NULL
967 };
968
969 /*
970 * Checks whether the MOS features that are active are supported by this
971 * (GRUB's) implementation of ZFS.
972 *
973 * Return:
974 * 0: Success.
975 * errnum: Failure.
976 */
977 static int
978 check_mos_features(dnode_phys_t *mosmdn, char *stack)
979 {
980 uint64_t objnum;
981 dnode_phys_t *dn;
982 uint8_t error = 0;
983
984 dn = (dnode_phys_t *)stack;
985 stack += DNODE_SIZE;
986
987 if ((errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT,
988 DMU_OT_OBJECT_DIRECTORY, dn, stack)) != 0)
989 return (errnum);
990
991 /*
992 * Find the object number for 'features_for_read' and retrieve its
993 * corresponding dnode. Note that we don't check features_for_write
994 * because GRUB is not opening the pool for write.
995 */
996 if ((errnum = zap_lookup(dn, DMU_POOL_FEATURES_FOR_READ, &objnum,
997 stack)) != 0)
998 return (errnum);
999
1000 if ((errnum = dnode_get(mosmdn, objnum, DMU_OTN_ZAP_METADATA,
1001 dn, stack)) != 0)
1002 return (errnum);
1003
1004 return (zap_iterate(dn, check_feature, spa_feature_names, stack));
1005 }
1006
1007 /*
1008 * Given a MOS metadnode, get the metadnode of a given filesystem name (fsname),
1009 * e.g. pool/rootfs, or a given object number (obj), e.g. the object number
1010 * of pool/rootfs.
1011 *
1012 * If no fsname and no obj are given, return the DSL_DIR metadnode.
1013 * If fsname is given, return its metadnode and its matching object number.
1014 * If only obj is given, return the metadnode for this object number.
1015 *
1016 * Return:
1017 * 0 - success
1018 * errnum - failure
1019 */
1020 static int
1021 get_objset_mdn(dnode_phys_t *mosmdn, char *fsname, uint64_t *obj,
1022 dnode_phys_t *mdn, char *stack)
1023 {
1024 uint64_t objnum, headobj;
1025 char *cname, ch;
1026 blkptr_t *bp;
1027 objset_phys_t *osp;
1028 int issnapshot = 0;
1029 char *snapname;
1030
1031 if (fsname == NULL && obj) {
1032 headobj = *obj;
1033 goto skip;
1034 }
1035
1036 if (errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT,
1037 DMU_OT_OBJECT_DIRECTORY, mdn, stack))
1038 return (errnum);
1039
1040 if (errnum = zap_lookup(mdn, DMU_POOL_ROOT_DATASET, &objnum,
1041 stack))
1042 return (errnum);
1043
1044 if (errnum = dnode_get(mosmdn, objnum, DMU_OT_DSL_DIR, mdn, stack))
1045 return (errnum);
1046
1047 if (fsname == NULL) {
1048 headobj =
1049 ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_head_dataset_obj;
1050 goto skip;
1051 }
1052
1053 /* take out the pool name */
1054 while (*fsname && !grub_isspace(*fsname) && *fsname != '/')
1055 fsname++;
1056
1057 while (*fsname && !grub_isspace(*fsname)) {
1058 uint64_t childobj;
1059
1060 while (*fsname == '/')
1061 fsname++;
1062
1063 cname = fsname;
1064 while (*fsname && !grub_isspace(*fsname) && *fsname != '/')
1065 fsname++;
1066 ch = *fsname;
1067 *fsname = 0;
1068
1069 snapname = cname;
1070 while (*snapname && !grub_isspace(*snapname) && *snapname !=
1071 '@')
1072 snapname++;
1073 if (*snapname == '@') {
1074 issnapshot = 1;
1075 *snapname = 0;
1076 }
1077 childobj =
1078 ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_child_dir_zapobj;
1079 if (errnum = dnode_get(mosmdn, childobj,
1080 DMU_OT_DSL_DIR_CHILD_MAP, mdn, stack))
1081 return (errnum);
1082
1083 if (zap_lookup(mdn, cname, &objnum, stack))
1084 return (ERR_FILESYSTEM_NOT_FOUND);
1085
1086 if (errnum = dnode_get(mosmdn, objnum, DMU_OT_DSL_DIR,
1087 mdn, stack))
1088 return (errnum);
1089
1090 *fsname = ch;
1091 if (issnapshot)
1092 *snapname = '@';
1093 }
1094 headobj = ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_head_dataset_obj;
1095 if (obj)
1096 *obj = headobj;
1097
1098 skip:
1099 if (errnum = dnode_get(mosmdn, headobj, DMU_OT_DSL_DATASET, mdn, stack))
1100 return (errnum);
1101 if (issnapshot) {
1102 uint64_t snapobj;
1103
1104 snapobj = ((dsl_dataset_phys_t *)DN_BONUS(mdn))->
1105 ds_snapnames_zapobj;
1106
1107 if (errnum = dnode_get(mosmdn, snapobj,
1108 DMU_OT_DSL_DS_SNAP_MAP, mdn, stack))
1109 return (errnum);
1110 if (zap_lookup(mdn, snapname + 1, &headobj, stack))
1111 return (ERR_FILESYSTEM_NOT_FOUND);
1112 if (errnum = dnode_get(mosmdn, headobj,
1113 DMU_OT_DSL_DATASET, mdn, stack))
1114 return (errnum);
1115 if (obj)
1116 *obj = headobj;
1117 }
1118
1119 bp = &((dsl_dataset_phys_t *)DN_BONUS(mdn))->ds_bp;
1120 osp = (objset_phys_t *)stack;
1121 stack += sizeof (objset_phys_t);
1122 if (errnum = zio_read(bp, osp, stack))
1123 return (errnum);
1124
1125 grub_memmove((char *)mdn, (char *)&osp->os_meta_dnode, DNODE_SIZE);
1126
1127 return (0);
1128 }
1129
1130 /*
1131 * For a given XDR packed nvlist, verify the first 4 bytes and move on.
1132 *
1133 * An XDR packed nvlist is encoded as (comments from nvs_xdr_create) :
1134 *
1135 * encoding method/host endian (4 bytes)
1136 * nvl_version (4 bytes)
1137 * nvl_nvflag (4 bytes)
1138 * encoded nvpairs:
1139 * encoded size of the nvpair (4 bytes)
1140 * decoded size of the nvpair (4 bytes)
1141 * name string size (4 bytes)
1142 * name string data (sizeof(NV_ALIGN4(string))
1143 * data type (4 bytes)
1144 * # of elements in the nvpair (4 bytes)
1145 * data
1146 * 2 zero's for the last nvpair
1147 * (end of the entire list) (8 bytes)
1148 *
1149 * Return:
1150 * 0 - success
1151 * 1 - failure
1152 */
1153 static int
1154 nvlist_unpack(char *nvlist, char **out)
1155 {
1156 /* Verify if the 1st and 2nd byte in the nvlist are valid. */
1157 if (nvlist[0] != NV_ENCODE_XDR || nvlist[1] != HOST_ENDIAN)
1158 return (1);
1159
1160 *out = nvlist + 4;
1161 return (0);
1162 }
1163
1164 static char *
1165 nvlist_array(char *nvlist, int index)
1166 {
1167 int i, encode_size;
1168
1169 for (i = 0; i < index; i++) {
1170 /* skip the header, nvl_version, and nvl_nvflag */
1171 nvlist = nvlist + 4 * 2;
1172
1173 while (encode_size = BSWAP_32(*(uint32_t *)nvlist))
1174 nvlist += encode_size; /* goto the next nvpair */
1175
1176 nvlist = nvlist + 4 * 2; /* skip the ending 2 zeros - 8 bytes */
1177 }
1178
1179 return (nvlist);
1180 }
1181
1182 /*
1183 * The nvlist_next_nvpair() function returns a handle to the next nvpair in the
1184 * list following nvpair. If nvpair is NULL, the first pair is returned. If
1185 * nvpair is the last pair in the nvlist, NULL is returned.
1186 */
1187 static char *
1188 nvlist_next_nvpair(char *nvl, char *nvpair)
1189 {
1190 char *cur, *prev;
1191 int encode_size;
1192
1193 if (nvl == NULL)
1194 return (NULL);
1195
1196 if (nvpair == NULL) {
1197 /* skip over nvl_version and nvl_nvflag */
1198 nvpair = nvl + 4 * 2;
1199 } else {
1200 /* skip to the next nvpair */
1201 encode_size = BSWAP_32(*(uint32_t *)nvpair);
1202 nvpair += encode_size;
1203 }
1204
1205 /* 8 bytes of 0 marks the end of the list */
1206 if (*(uint64_t *)nvpair == 0)
1207 return (NULL);
1208
1209 return (nvpair);
1210 }
1211
1212 /*
1213 * This function returns 0 on success and 1 on failure. On success, a string
1214 * containing the name of nvpair is saved in buf.
1215 */
1216 static int
1217 nvpair_name(char *nvp, char *buf, int buflen)
1218 {
1219 int len;
1220
1221 /* skip over encode/decode size */
1222 nvp += 4 * 2;
1223
1224 len = BSWAP_32(*(uint32_t *)nvp);
1225 if (buflen < len + 1)
1226 return (1);
1227
1228 grub_memmove(buf, nvp + 4, len);
1229 buf[len] = '\0';
1230
1231 return (0);
1232 }
1233
1234 /*
1235 * This function retrieves the value of the nvpair in the form of enumerated
1236 * type data_type_t. This is used to determine the appropriate type to pass to
1237 * nvpair_value().
1238 */
1239 static int
1240 nvpair_type(char *nvp)
1241 {
1242 int name_len, type;
1243
1244 /* skip over encode/decode size */
1245 nvp += 4 * 2;
1246
1247 /* skip over name_len */
1248 name_len = BSWAP_32(*(uint32_t *)nvp);
1249 nvp += 4;
1250
1251 /* skip over name */
1252 nvp = nvp + ((name_len + 3) & ~3); /* align */
1253
1254 type = BSWAP_32(*(uint32_t *)nvp);
1255
1256 return (type);
1257 }
1258
1259 static int
1260 nvpair_value(char *nvp, void *val, int valtype, int *nelmp)
1261 {
1262 int name_len, type, slen;
1263 char *strval = val;
1264 uint64_t *intval = val;
1265
1266 /* skip over encode/decode size */
1267 nvp += 4 * 2;
1268
1269 /* skip over name_len */
1270 name_len = BSWAP_32(*(uint32_t *)nvp);
1271 nvp += 4;
1272
1273 /* skip over name */
1274 nvp = nvp + ((name_len + 3) & ~3); /* align */
1275
1276 /* skip over type */
1277 type = BSWAP_32(*(uint32_t *)nvp);
1278 nvp += 4;
1279
1280 if (type == valtype) {
1281 int nelm;
1282
1283 nelm = BSWAP_32(*(uint32_t *)nvp);
1284 if (valtype != DATA_TYPE_BOOLEAN && nelm < 1)
1285 return (1);
1286 nvp += 4;
1287
1288 switch (valtype) {
1289 case DATA_TYPE_BOOLEAN:
1290 return (0);
1291
1292 case DATA_TYPE_STRING:
1293 slen = BSWAP_32(*(uint32_t *)nvp);
1294 nvp += 4;
1295 grub_memmove(strval, nvp, slen);
1296 strval[slen] = '\0';
1297 return (0);
1298
1299 case DATA_TYPE_UINT64:
1300 *intval = BSWAP_64(*(uint64_t *)nvp);
1301 return (0);
1302
1303 case DATA_TYPE_NVLIST:
1304 *(void **)val = (void *)nvp;
1305 return (0);
1306
1307 case DATA_TYPE_NVLIST_ARRAY:
1308 *(void **)val = (void *)nvp;
1309 if (nelmp)
1310 *nelmp = nelm;
1311 return (0);
1312 }
1313 }
1314
1315 return (1);
1316 }
1317
1318 static int
1319 nvlist_lookup_value(char *nvlist, char *name, void *val, int valtype,
1320 int *nelmp)
1321 {
1322 char *nvpair;
1323
1324 for (nvpair = nvlist_next_nvpair(nvlist, NULL);
1325 nvpair != NULL;
1326 nvpair = nvlist_next_nvpair(nvlist, nvpair)) {
1327 int name_len = BSWAP_32(*(uint32_t *)(nvpair + 4 * 2));
1328 char *nvp_name = nvpair + 4 * 3;
1329
1330 if ((grub_strncmp(nvp_name, name, name_len) == 0) &&
1331 nvpair_type(nvpair) == valtype) {
1332 return (nvpair_value(nvpair, val, valtype, nelmp));
1333 }
1334 }
1335 return (1);
1336 }
1337
1338 /*
1339 * Check if this vdev is online and is in a good state.
1340 */
1341 static int
1342 vdev_validate(char *nv)
1343 {
1344 uint64_t ival;
1345
1346 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_OFFLINE, &ival,
1347 DATA_TYPE_UINT64, NULL) == 0 ||
1348 nvlist_lookup_value(nv, ZPOOL_CONFIG_FAULTED, &ival,
1349 DATA_TYPE_UINT64, NULL) == 0 ||
1350 nvlist_lookup_value(nv, ZPOOL_CONFIG_REMOVED, &ival,
1351 DATA_TYPE_UINT64, NULL) == 0)
1352 return (ERR_DEV_VALUES);
1353
1354 return (0);
1355 }
1356
1357 /*
1358 * Get a valid vdev pathname/devid from the boot device.
1359 * The caller should already allocate MAXPATHLEN memory for bootpath and devid.
1360 */
1361 static int
1362 vdev_get_bootpath(char *nv, uint64_t inguid, char *devid, char *bootpath,
1363 int is_spare)
1364 {
1365 char type[16];
1366
1367 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_TYPE, &type, DATA_TYPE_STRING,
1368 NULL))
1369 return (ERR_FSYS_CORRUPT);
1370
1371 if (grub_strcmp(type, VDEV_TYPE_DISK) == 0) {
1372 uint64_t guid;
1373
1374 if (vdev_validate(nv) != 0)
1375 return (ERR_NO_BOOTPATH);
1376
1377 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_GUID,
1378 &guid, DATA_TYPE_UINT64, NULL) != 0)
1379 return (ERR_NO_BOOTPATH);
1380
1381 if (guid != inguid)
1382 return (ERR_NO_BOOTPATH);
1383
1384 /* for a spare vdev, pick the disk labeled with "is_spare" */
1385 if (is_spare) {
1386 uint64_t spare = 0;
1387 (void) nvlist_lookup_value(nv, ZPOOL_CONFIG_IS_SPARE,
1388 &spare, DATA_TYPE_UINT64, NULL);
1389 if (!spare)
1390 return (ERR_NO_BOOTPATH);
1391 }
1392
1393 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_PHYS_PATH,
1394 bootpath, DATA_TYPE_STRING, NULL) != 0)
1395 bootpath[0] = '\0';
1396
1397 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_DEVID,
1398 devid, DATA_TYPE_STRING, NULL) != 0)
1399 devid[0] = '\0';
1400
1401 if (grub_strlen(bootpath) >= MAXPATHLEN ||
1402 grub_strlen(devid) >= MAXPATHLEN)
1403 return (ERR_WONT_FIT);
1404
1405 return (0);
1406
1407 } else if (grub_strcmp(type, VDEV_TYPE_MIRROR) == 0 ||
1408 grub_strcmp(type, VDEV_TYPE_REPLACING) == 0 ||
1409 (is_spare = (grub_strcmp(type, VDEV_TYPE_SPARE) == 0))) {
1410 int nelm, i;
1411 char *child;
1412
1413 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_CHILDREN, &child,
1414 DATA_TYPE_NVLIST_ARRAY, &nelm))
1415 return (ERR_FSYS_CORRUPT);
1416
1417 for (i = 0; i < nelm; i++) {
1418 char *child_i;
1419
1420 child_i = nvlist_array(child, i);
1421 if (vdev_get_bootpath(child_i, inguid, devid,
1422 bootpath, is_spare) == 0)
1423 return (0);
1424 }
1425 }
1426
1427 return (ERR_NO_BOOTPATH);
1428 }
1429
1430 /*
1431 * Check the disk label information and retrieve needed vdev name-value pairs.
1432 *
1433 * Return:
1434 * 0 - success
1435 * ERR_* - failure
1436 */
1437 static int
1438 check_pool_label(uint64_t sector, char *stack, char *outdevid,
1439 char *outpath, uint64_t *outguid, uint64_t *outashift, uint64_t *outversion)
1440 {
1441 vdev_phys_t *vdev;
1442 uint64_t pool_state, txg = 0;
1443 char *nvlist, *nv, *features;
1444 uint64_t diskguid;
1445
1446 sector += (VDEV_SKIP_SIZE >> SPA_MINBLOCKSHIFT);
1447
1448 /* Read in the vdev name-value pair list (112K). */
1449 if (devread(sector, 0, VDEV_PHYS_SIZE, stack) == 0)
1450 return (ERR_READ);
1451
1452 vdev = (vdev_phys_t *)stack;
1453 stack += sizeof (vdev_phys_t);
1454
1455 if (nvlist_unpack(vdev->vp_nvlist, &nvlist))
1456 return (ERR_FSYS_CORRUPT);
1457
1458 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_STATE, &pool_state,
1459 DATA_TYPE_UINT64, NULL))
1460 return (ERR_FSYS_CORRUPT);
1461
1462 if (pool_state == POOL_STATE_DESTROYED)
1463 return (ERR_FILESYSTEM_NOT_FOUND);
1464
1465 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_NAME,
1466 current_rootpool, DATA_TYPE_STRING, NULL))
1467 return (ERR_FSYS_CORRUPT);
1468
1469 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_TXG, &txg,
1470 DATA_TYPE_UINT64, NULL))
1471 return (ERR_FSYS_CORRUPT);
1472
1473 /* not an active device */
1474 if (txg == 0)
1475 return (ERR_NO_BOOTPATH);
1476
1477 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_VERSION, outversion,
1478 DATA_TYPE_UINT64, NULL))
1479 return (ERR_FSYS_CORRUPT);
1480 if (!SPA_VERSION_IS_SUPPORTED(*outversion))
1481 return (ERR_NEWER_VERSION);
1482 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_VDEV_TREE, &nv,
1483 DATA_TYPE_NVLIST, NULL))
1484 return (ERR_FSYS_CORRUPT);
1485 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_GUID, &diskguid,
1486 DATA_TYPE_UINT64, NULL))
1487 return (ERR_FSYS_CORRUPT);
1488 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_ASHIFT, outashift,
1489 DATA_TYPE_UINT64, NULL) != 0)
1490 return (ERR_FSYS_CORRUPT);
1491 if (vdev_get_bootpath(nv, diskguid, outdevid, outpath, 0))
1492 return (ERR_NO_BOOTPATH);
1493 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_GUID, outguid,
1494 DATA_TYPE_UINT64, NULL))
1495 return (ERR_FSYS_CORRUPT);
1496
1497 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_FEATURES_FOR_READ,
1498 &features, DATA_TYPE_NVLIST, NULL) == 0) {
1499 char *nvp;
1500 char *name = stack;
1501 stack += MAXNAMELEN;
1502
1503 for (nvp = nvlist_next_nvpair(features, NULL);
1504 nvp != NULL;
1505 nvp = nvlist_next_nvpair(features, nvp)) {
1506 zap_attribute_t za;
1507
1508 if (nvpair_name(nvp, name, MAXNAMELEN) != 0)
1509 return (ERR_FSYS_CORRUPT);
1510
1511 za.za_integer_length = 8;
1512 za.za_num_integers = 1;
1513 za.za_first_integer = 1;
1514 za.za_name = name;
1515 if (check_feature(&za, spa_feature_names, stack) != 0)
1516 return (ERR_NEWER_VERSION);
1517 }
1518 }
1519
1520 return (0);
1521 }
1522
1523 /*
1524 * zfs_mount() locates a valid uberblock of the root pool and read in its MOS
1525 * to the memory address MOS.
1526 *
1527 * Return:
1528 * 1 - success
1529 * 0 - failure
1530 */
1531 int
1532 zfs_mount(void)
1533 {
1534 char *stack, *ub_array;
1535 int label = 0;
1536 uberblock_t *ubbest;
1537 objset_phys_t *osp;
1538 char tmp_bootpath[MAXNAMELEN];
1539 char tmp_devid[MAXNAMELEN];
1540 uint64_t tmp_guid, ashift, version;
1541 uint64_t adjpl = (uint64_t)part_length << SPA_MINBLOCKSHIFT;
1542 int err = errnum; /* preserve previous errnum state */
1543
1544 /* if it's our first time here, zero the best uberblock out */
1545 if (best_drive == 0 && best_part == 0 && find_best_root) {
1546 grub_memset(¤t_uberblock, 0, sizeof (uberblock_t));
1547 pool_guid = 0;
1548 }
1549
1550 stackbase = ZFS_SCRATCH;
1551 stack = stackbase;
1552 ub_array = stack;
1553 stack += VDEV_UBERBLOCK_RING;
1554
1555 osp = (objset_phys_t *)stack;
1556 stack += sizeof (objset_phys_t);
1557 adjpl = P2ALIGN(adjpl, (uint64_t)sizeof (vdev_label_t));
1558
1559 for (label = 0; label < VDEV_LABELS; label++) {
1560
1561 /*
1562 * some eltorito stacks don't give us a size and
1563 * we end up setting the size to MAXUINT, further
1564 * some of these devices stop working once a single
1565 * read past the end has been issued. Checking
1566 * for a maximum part_length and skipping the backup
1567 * labels at the end of the slice/partition/device
1568 * avoids breaking down on such devices.
1569 */
1570 if (part_length == MAXUINT && label == 2)
1571 break;
1572
1573 uint64_t sector = vdev_label_start(adjpl,
1574 label) >> SPA_MINBLOCKSHIFT;
1575
1576 /* Read in the uberblock ring (128K). */
1577 if (devread(sector +
1578 ((VDEV_SKIP_SIZE + VDEV_PHYS_SIZE) >> SPA_MINBLOCKSHIFT),
1579 0, VDEV_UBERBLOCK_RING, ub_array) == 0)
1580 continue;
1581
1582 if (check_pool_label(sector, stack, tmp_devid,
1583 tmp_bootpath, &tmp_guid, &ashift, &version))
1584 continue;
1585
1586 if (pool_guid == 0)
1587 pool_guid = tmp_guid;
1588
1589 if ((ubbest = find_bestub(ub_array, ashift, sector)) == NULL ||
1590 zio_read(&ubbest->ub_rootbp, osp, stack) != 0)
1591 continue;
1592
1593 VERIFY_OS_TYPE(osp, DMU_OST_META);
1594
1595 if (version >= SPA_VERSION_FEATURES &&
1596 check_mos_features(&osp->os_meta_dnode, stack) != 0)
1597 continue;
1598
1599 if (find_best_root && ((pool_guid != tmp_guid) ||
1600 vdev_uberblock_compare(ubbest, &(current_uberblock)) <= 0))
1601 continue;
1602
1603 /* Got the MOS. Save it at the memory addr MOS. */
1604 grub_memmove(MOS, &osp->os_meta_dnode, DNODE_SIZE);
1605 grub_memmove(¤t_uberblock, ubbest, sizeof (uberblock_t));
1606 grub_memmove(current_bootpath, tmp_bootpath, MAXNAMELEN);
1607 grub_memmove(current_devid, tmp_devid, grub_strlen(tmp_devid));
1608 is_zfs_mount = 1;
1609 return (1);
1610 }
1611
1612 /*
1613 * While some fs impls. (tftp) rely on setting and keeping
1614 * global errnums set, others won't reset it and will break
1615 * when issuing rawreads. The goal here is to simply not
1616 * have zfs mount attempts impact the previous state.
1617 */
1618 errnum = err;
1619 return (0);
1620 }
1621
1622 /*
1623 * zfs_open() locates a file in the rootpool by following the
1624 * MOS and places the dnode of the file in the memory address DNODE.
1625 *
1626 * Return:
1627 * 1 - success
1628 * 0 - failure
1629 */
1630 int
1631 zfs_open(char *filename)
1632 {
1633 char *stack;
1634 dnode_phys_t *mdn;
1635
1636 file_buf = NULL;
1637 stackbase = ZFS_SCRATCH;
1638 stack = stackbase;
1639
1640 mdn = (dnode_phys_t *)stack;
1641 stack += sizeof (dnode_phys_t);
1642
1643 dnode_mdn = NULL;
1644 dnode_buf = (dnode_phys_t *)stack;
1645 stack += 1<<DNODE_BLOCK_SHIFT;
1646
1647 /*
1648 * menu.lst is placed at the root pool filesystem level,
1649 * do not goto 'current_bootfs'.
1650 */
1651 if (is_top_dataset_file(filename)) {
1652 if (errnum = get_objset_mdn(MOS, NULL, NULL, mdn, stack))
1653 return (0);
1654
1655 current_bootfs_obj = 0;
1656 } else {
1657 if (current_bootfs[0] == '\0') {
1658 /* Get the default root filesystem object number */
1659 if (errnum = get_default_bootfsobj(MOS,
1660 ¤t_bootfs_obj, stack))
1661 return (0);
1662
1663 if (errnum = get_objset_mdn(MOS, NULL,
1664 ¤t_bootfs_obj, mdn, stack))
1665 return (0);
1666 } else {
1667 if (errnum = get_objset_mdn(MOS, current_bootfs,
1668 ¤t_bootfs_obj, mdn, stack)) {
1669 grub_memset(current_bootfs, 0, MAXNAMELEN);
1670 return (0);
1671 }
1672 }
1673 }
1674
1675 if (dnode_get_path(mdn, filename, DNODE, stack)) {
1676 errnum = ERR_FILE_NOT_FOUND;
1677 return (0);
1678 }
1679
1680 /* get the file size and set the file position to 0 */
1681
1682 /*
1683 * For DMU_OT_SA we will need to locate the SIZE attribute
1684 * attribute, which could be either in the bonus buffer
1685 * or the "spill" block.
1686 */
1687 if (DNODE->dn_bonustype == DMU_OT_SA) {
1688 sa_hdr_phys_t *sahdrp;
1689 int hdrsize;
1690
1691 if (DNODE->dn_bonuslen != 0) {
1692 sahdrp = (sa_hdr_phys_t *)DN_BONUS(DNODE);
1693 } else {
1694 if (DNODE->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
1695 blkptr_t *bp = &DNODE->dn_spill;
1696 void *buf;
1697
1698 buf = (void *)stack;
1699 stack += BP_GET_LSIZE(bp);
1700
1701 /* reset errnum to rawread() failure */
1702 errnum = 0;
1703 if (zio_read(bp, buf, stack) != 0) {
1704 return (0);
1705 }
1706 sahdrp = buf;
1707 } else {
1708 errnum = ERR_FSYS_CORRUPT;
1709 return (0);
1710 }
1711 }
1712 hdrsize = SA_HDR_SIZE(sahdrp);
1713 filemax = *(uint64_t *)((char *)sahdrp + hdrsize +
1714 SA_SIZE_OFFSET);
1715 } else {
1716 filemax = ((znode_phys_t *)DN_BONUS(DNODE))->zp_size;
1717 }
1718 filepos = 0;
1719
1720 dnode_buf = NULL;
1721 return (1);
1722 }
1723
1724 /*
1725 * zfs_read reads in the data blocks pointed by the DNODE.
1726 *
1727 * Return:
1728 * len - the length successfully read in to the buffer
1729 * 0 - failure
1730 */
1731 int
1732 zfs_read(char *buf, int len)
1733 {
1734 char *stack;
1735 int blksz, length, movesize;
1736
1737 if (file_buf == NULL) {
1738 file_buf = stackbase;
1739 stackbase += SPA_MAXBLOCKSIZE;
1740 file_start = file_end = 0;
1741 }
1742 stack = stackbase;
1743
1744 /*
1745 * If offset is in memory, move it into the buffer provided and return.
1746 */
1747 if (filepos >= file_start && filepos+len <= file_end) {
1748 grub_memmove(buf, file_buf + filepos - file_start, len);
1749 filepos += len;
1750 return (len);
1751 }
1752
1753 blksz = DNODE->dn_datablkszsec << SPA_MINBLOCKSHIFT;
1754
1755 /*
1756 * Entire Dnode is too big to fit into the space available. We
1757 * will need to read it in chunks. This could be optimized to
1758 * read in as large a chunk as there is space available, but for
1759 * now, this only reads in one data block at a time.
1760 */
1761 length = len;
1762 while (length) {
1763 /*
1764 * Find requested blkid and the offset within that block.
1765 */
1766 uint64_t blkid = filepos / blksz;
1767
1768 if (errnum = dmu_read(DNODE, blkid, file_buf, stack))
1769 return (0);
1770
1771 file_start = blkid * blksz;
1772 file_end = file_start + blksz;
1773
1774 movesize = MIN(length, file_end - filepos);
1775
1776 grub_memmove(buf, file_buf + filepos - file_start,
1777 movesize);
1778 buf += movesize;
1779 length -= movesize;
1780 filepos += movesize;
1781 }
1782
1783 return (len);
1784 }
1785
1786 /*
1787 * No-Op
1788 */
1789 int
1790 zfs_embed(int *start_sector, int needed_sectors)
1791 {
1792 return (1);
1793 }
1794
1795 #endif /* FSYS_ZFS */