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, 2015 by Delphix. All rights reserved.
27 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
28 * Copyright (c) 2014 Integros [integros.com]
29 */
30
31 /*
32 * The zfs plug-in routines for GRUB are:
33 *
34 * zfs_mount() - locates a valid uberblock of the root pool and reads
35 * in its MOS at the memory address MOS.
36 *
37 * zfs_open() - locates a plain file object by following the MOS
38 * and places its dnode at the memory address DNODE.
39 *
40 * zfs_read() - read in the data blocks pointed by the DNODE.
41 *
42 * ZFS_SCRATCH is used as a working area.
43 *
44 * (memory addr) MOS DNODE ZFS_SCRATCH
45 * | | |
46 * +-------V---------V----------V---------------+
47 * memory | | dnode | dnode | scratch |
48 * | | 512B | 512B | area |
49 * +--------------------------------------------+
50 */
51
52 #ifdef FSYS_ZFS
53
54 #include "shared.h"
55 #include "filesys.h"
56 #include "fsys_zfs.h"
57
58 /* cache for a file block of the currently zfs_open()-ed file */
59 static void *file_buf = NULL;
60 static uint64_t file_start = 0;
61 static uint64_t file_end = 0;
62
63 /* cache for a dnode block */
64 static dnode_phys_t *dnode_buf = NULL;
65 static dnode_phys_t *dnode_mdn = NULL;
66 static uint64_t dnode_start = 0;
67 static uint64_t dnode_end = 0;
68
69 static uint64_t pool_guid = 0;
70 static uberblock_t current_uberblock;
71 static char *stackbase;
72
73 decomp_entry_t decomp_table[ZIO_COMPRESS_FUNCTIONS] =
74 {
75 {"inherit", 0}, /* ZIO_COMPRESS_INHERIT */
76 {"on", lzjb_decompress}, /* ZIO_COMPRESS_ON */
77 {"off", 0}, /* ZIO_COMPRESS_OFF */
78 {"lzjb", lzjb_decompress}, /* ZIO_COMPRESS_LZJB */
79 {"empty", 0}, /* ZIO_COMPRESS_EMPTY */
80 {"gzip-1", 0}, /* ZIO_COMPRESS_GZIP_1 */
81 {"gzip-2", 0}, /* ZIO_COMPRESS_GZIP_2 */
82 {"gzip-3", 0}, /* ZIO_COMPRESS_GZIP_3 */
83 {"gzip-4", 0}, /* ZIO_COMPRESS_GZIP_4 */
84 {"gzip-5", 0}, /* ZIO_COMPRESS_GZIP_5 */
85 {"gzip-6", 0}, /* ZIO_COMPRESS_GZIP_6 */
86 {"gzip-7", 0}, /* ZIO_COMPRESS_GZIP_7 */
87 {"gzip-8", 0}, /* ZIO_COMPRESS_GZIP_8 */
88 {"gzip-9", 0}, /* ZIO_COMPRESS_GZIP_9 */
89 {"zle", 0}, /* ZIO_COMPRESS_ZLE */
90 {"lz4", lz4_decompress} /* ZIO_COMPRESS_LZ4 */
91 };
92
93 static int zio_read_data(blkptr_t *bp, void *buf, char *stack);
94
95 /*
96 * Our own version of bcmp().
97 */
98 static int
zfs_bcmp(const void * s1,const void * s2,size_t n)99 zfs_bcmp(const void *s1, const void *s2, size_t n)
100 {
101 const uchar_t *ps1 = s1;
102 const uchar_t *ps2 = s2;
103
104 if (s1 != s2 && n != 0) {
105 do {
106 if (*ps1++ != *ps2++)
107 return (1);
108 } while (--n != 0);
109 }
110
111 return (0);
112 }
113
114 /*
115 * Our own version of log2(). Same thing as highbit()-1.
116 */
117 static int
zfs_log2(uint64_t num)118 zfs_log2(uint64_t num)
119 {
120 int i = 0;
121
122 while (num > 1) {
123 i++;
124 num = num >> 1;
125 }
126
127 return (i);
128 }
129
130 /* Checksum Functions */
131 static void
zio_checksum_off(const void * buf,uint64_t size,zio_cksum_t * zcp)132 zio_checksum_off(const void *buf, uint64_t size, zio_cksum_t *zcp)
133 {
134 ZIO_SET_CHECKSUM(zcp, 0, 0, 0, 0);
135 }
136
137 /* Checksum Table and Values */
138 zio_checksum_info_t zio_checksum_table[ZIO_CHECKSUM_FUNCTIONS] = {
139 {{NULL, NULL}, 0, 0, "inherit"},
140 {{NULL, NULL}, 0, 0, "on"},
141 {{zio_checksum_off, zio_checksum_off}, 0, 0, "off"},
142 {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 1, "label"},
143 {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 1, "gang_header"},
144 {{NULL, NULL}, 0, 0, "zilog"},
145 {{fletcher_2_native, fletcher_2_byteswap}, 0, 0, "fletcher2"},
146 {{fletcher_4_native, fletcher_4_byteswap}, 1, 0, "fletcher4"},
147 {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 0, "SHA256"},
148 {{NULL, NULL}, 0, 0, "zilog2"},
149 {{zio_checksum_off, zio_checksum_off}, 0, 0, "noparity"},
150 {{zio_checksum_SHA512, NULL}, 0, 0, "SHA512"}
151 };
152
153 /*
154 * zio_checksum_verify: Provides support for checksum verification.
155 *
156 * Fletcher2, Fletcher4, SHA-256 and SHA-512/256 are supported.
157 *
158 * Return:
159 * -1 = Failure
160 * 0 = Success
161 */
162 static int
zio_checksum_verify(blkptr_t * bp,char * data,int size)163 zio_checksum_verify(blkptr_t *bp, char *data, int size)
164 {
165 zio_cksum_t zc = bp->blk_cksum;
166 uint32_t checksum = BP_GET_CHECKSUM(bp);
167 int byteswap = BP_SHOULD_BYTESWAP(bp);
168 zio_eck_t *zec = (zio_eck_t *)(data + size) - 1;
169 zio_checksum_info_t *ci = &zio_checksum_table[checksum];
170 zio_cksum_t actual_cksum, expected_cksum;
171
172 if (byteswap) {
173 grub_printf("byteswap not supported\n");
174 return (-1);
175 }
176
177 if (checksum >= ZIO_CHECKSUM_FUNCTIONS || ci->ci_func[0] == NULL) {
178 grub_printf("checksum algorithm %u not supported\n", checksum);
179 return (-1);
180 }
181
182 if (ci->ci_eck) {
183 expected_cksum = zec->zec_cksum;
184 zec->zec_cksum = zc;
185 ci->ci_func[0](data, size, &actual_cksum);
186 zec->zec_cksum = expected_cksum;
187 zc = expected_cksum;
188 } else {
189 ci->ci_func[byteswap](data, size, &actual_cksum);
190 }
191
192 if ((actual_cksum.zc_word[0] - zc.zc_word[0]) |
193 (actual_cksum.zc_word[1] - zc.zc_word[1]) |
194 (actual_cksum.zc_word[2] - zc.zc_word[2]) |
195 (actual_cksum.zc_word[3] - zc.zc_word[3]))
196 return (-1);
197
198 return (0);
199 }
200
201 /*
202 * vdev_label_start returns the physical disk offset (in bytes) of
203 * label "l".
204 */
205 static uint64_t
vdev_label_start(uint64_t psize,int l)206 vdev_label_start(uint64_t psize, int l)
207 {
208 return (l * sizeof (vdev_label_t) + (l < VDEV_LABELS / 2 ?
209 0 : psize - VDEV_LABELS * sizeof (vdev_label_t)));
210 }
211
212 /*
213 * vdev_uberblock_compare takes two uberblock structures and returns an integer
214 * indicating the more recent of the two.
215 * Return Value = 1 if ub2 is more recent
216 * Return Value = -1 if ub1 is more recent
217 * The most recent uberblock is determined using its transaction number and
218 * timestamp. The uberblock with the highest transaction number is
219 * considered "newer". If the transaction numbers of the two blocks match, the
220 * timestamps are compared to determine the "newer" of the two.
221 */
222 static int
vdev_uberblock_compare(uberblock_t * ub1,uberblock_t * ub2)223 vdev_uberblock_compare(uberblock_t *ub1, uberblock_t *ub2)
224 {
225 if (ub1->ub_txg < ub2->ub_txg)
226 return (-1);
227 if (ub1->ub_txg > ub2->ub_txg)
228 return (1);
229
230 if (ub1->ub_timestamp < ub2->ub_timestamp)
231 return (-1);
232 if (ub1->ub_timestamp > ub2->ub_timestamp)
233 return (1);
234
235 return (0);
236 }
237
238 /*
239 * Three pieces of information are needed to verify an uberblock: the magic
240 * number, the version number, and the checksum.
241 *
242 * Return:
243 * 0 - Success
244 * -1 - Failure
245 */
246 static int
uberblock_verify(uberblock_t * uber,uint64_t ub_size,uint64_t offset)247 uberblock_verify(uberblock_t *uber, uint64_t ub_size, uint64_t offset)
248 {
249 blkptr_t bp;
250
251 BP_ZERO(&bp);
252 BP_SET_CHECKSUM(&bp, ZIO_CHECKSUM_LABEL);
253 BP_SET_BYTEORDER(&bp, ZFS_HOST_BYTEORDER);
254 ZIO_SET_CHECKSUM(&bp.blk_cksum, offset, 0, 0, 0);
255
256 if (zio_checksum_verify(&bp, (char *)uber, ub_size) != 0)
257 return (-1);
258
259 if (uber->ub_magic == UBERBLOCK_MAGIC &&
260 SPA_VERSION_IS_SUPPORTED(uber->ub_version))
261 return (0);
262
263 return (-1);
264 }
265
266 /*
267 * Find the best uberblock.
268 * Return:
269 * Success - Pointer to the best uberblock.
270 * Failure - NULL
271 */
272 static uberblock_t *
find_bestub(char * ub_array,uint64_t ashift,uint64_t sector)273 find_bestub(char *ub_array, uint64_t ashift, uint64_t sector)
274 {
275 uberblock_t *ubbest = NULL;
276 uberblock_t *ubnext;
277 uint64_t offset, ub_size;
278 int i;
279
280 ub_size = VDEV_UBERBLOCK_SIZE(ashift);
281
282 for (i = 0; i < VDEV_UBERBLOCK_COUNT(ashift); i++) {
283 ubnext = (uberblock_t *)ub_array;
284 ub_array += ub_size;
285 offset = (sector << SPA_MINBLOCKSHIFT) +
286 VDEV_UBERBLOCK_OFFSET(ashift, i);
287
288 if (uberblock_verify(ubnext, ub_size, offset) != 0)
289 continue;
290
291 if (ubbest == NULL ||
292 vdev_uberblock_compare(ubnext, ubbest) > 0)
293 ubbest = ubnext;
294 }
295
296 return (ubbest);
297 }
298
299 /*
300 * Read a block of data based on the gang block address dva,
301 * and put its data in buf.
302 *
303 * Return:
304 * 0 - success
305 * 1 - failure
306 */
307 static int
zio_read_gang(blkptr_t * bp,dva_t * dva,void * buf,char * stack)308 zio_read_gang(blkptr_t *bp, dva_t *dva, void *buf, char *stack)
309 {
310 zio_gbh_phys_t *zio_gb;
311 uint64_t offset, sector;
312 blkptr_t tmpbp;
313 int i;
314
315 zio_gb = (zio_gbh_phys_t *)stack;
316 stack += SPA_GANGBLOCKSIZE;
317 offset = DVA_GET_OFFSET(dva);
318 sector = DVA_OFFSET_TO_PHYS_SECTOR(offset);
319
320 /* read in the gang block header */
321 if (devread(sector, 0, SPA_GANGBLOCKSIZE, (char *)zio_gb) == 0) {
322 grub_printf("failed to read in a gang block header\n");
323 return (1);
324 }
325
326 /* self checksuming the gang block header */
327 BP_ZERO(&tmpbp);
328 BP_SET_CHECKSUM(&tmpbp, ZIO_CHECKSUM_GANG_HEADER);
329 BP_SET_BYTEORDER(&tmpbp, ZFS_HOST_BYTEORDER);
330 ZIO_SET_CHECKSUM(&tmpbp.blk_cksum, DVA_GET_VDEV(dva),
331 DVA_GET_OFFSET(dva), bp->blk_birth, 0);
332 if (zio_checksum_verify(&tmpbp, (char *)zio_gb, SPA_GANGBLOCKSIZE)) {
333 grub_printf("failed to checksum a gang block header\n");
334 return (1);
335 }
336
337 for (i = 0; i < SPA_GBH_NBLKPTRS; i++) {
338 if (BP_IS_HOLE(&zio_gb->zg_blkptr[i]))
339 continue;
340
341 if (zio_read_data(&zio_gb->zg_blkptr[i], buf, stack))
342 return (1);
343 buf += BP_GET_PSIZE(&zio_gb->zg_blkptr[i]);
344 }
345
346 return (0);
347 }
348
349 /*
350 * Read in a block of raw data to buf.
351 *
352 * Return:
353 * 0 - success
354 * 1 - failure
355 */
356 static int
zio_read_data(blkptr_t * bp,void * buf,char * stack)357 zio_read_data(blkptr_t *bp, void *buf, char *stack)
358 {
359 int i, psize;
360
361 psize = BP_GET_PSIZE(bp);
362
363 /* pick a good dva from the block pointer */
364 for (i = 0; i < SPA_DVAS_PER_BP; i++) {
365 uint64_t offset, sector;
366
367 if (bp->blk_dva[i].dva_word[0] == 0 &&
368 bp->blk_dva[i].dva_word[1] == 0)
369 continue;
370
371 if (DVA_GET_GANG(&bp->blk_dva[i])) {
372 if (zio_read_gang(bp, &bp->blk_dva[i], buf, stack) != 0)
373 continue;
374 } else {
375 /* read in a data block */
376 offset = DVA_GET_OFFSET(&bp->blk_dva[i]);
377 sector = DVA_OFFSET_TO_PHYS_SECTOR(offset);
378 if (devread(sector, 0, psize, buf) == 0)
379 continue;
380 }
381
382 /* verify that the checksum matches */
383 if (zio_checksum_verify(bp, buf, psize) == 0) {
384 return (0);
385 }
386 }
387
388 grub_printf("could not read block due to EIO or ECKSUM\n");
389 return (1);
390 }
391
392 /*
393 * buf must be at least BPE_GET_PSIZE(bp) bytes long (which will never be
394 * more than BPE_PAYLOAD_SIZE bytes).
395 */
396 static void
decode_embedded_bp_compressed(const blkptr_t * bp,void * buf)397 decode_embedded_bp_compressed(const blkptr_t *bp, void *buf)
398 {
399 int psize, i;
400 uint8_t *buf8 = buf;
401 uint64_t w = 0;
402 const uint64_t *bp64 = (const uint64_t *)bp;
403
404 psize = BPE_GET_PSIZE(bp);
405
406 /*
407 * Decode the words of the block pointer into the byte array.
408 * Low bits of first word are the first byte (little endian).
409 */
410 for (i = 0; i < psize; i++) {
411 if (i % sizeof (w) == 0) {
412 /* beginning of a word */
413 w = *bp64;
414 bp64++;
415 if (!BPE_IS_PAYLOADWORD(bp, bp64))
416 bp64++;
417 }
418 buf8[i] = BF64_GET(w, (i % sizeof (w)) * NBBY, NBBY);
419 }
420 }
421
422 /*
423 * Fill in the buffer with the (decompressed) payload of the embedded
424 * blkptr_t. Takes into account compression and byteorder (the payload is
425 * treated as a stream of bytes).
426 * Return 0 on success, or ENOSPC if it won't fit in the buffer.
427 */
428 static int
decode_embedded_bp(const blkptr_t * bp,void * buf)429 decode_embedded_bp(const blkptr_t *bp, void *buf)
430 {
431 int comp;
432 int lsize, psize;
433 uint8_t *dst = buf;
434 uint64_t w = 0;
435
436 lsize = BPE_GET_LSIZE(bp);
437 psize = BPE_GET_PSIZE(bp);
438 comp = BP_GET_COMPRESS(bp);
439
440 if (comp != ZIO_COMPRESS_OFF) {
441 uint8_t dstbuf[BPE_PAYLOAD_SIZE];
442
443 if ((unsigned int)comp >= ZIO_COMPRESS_FUNCTIONS ||
444 decomp_table[comp].decomp_func == NULL) {
445 grub_printf("compression algorithm not supported\n");
446 return (ERR_FSYS_CORRUPT);
447 }
448
449 decode_embedded_bp_compressed(bp, dstbuf);
450 decomp_table[comp].decomp_func(dstbuf, buf, psize, lsize);
451 } else {
452 decode_embedded_bp_compressed(bp, buf);
453 }
454
455 return (0);
456 }
457
458 /*
459 * Read in a block of data, verify its checksum, decompress if needed,
460 * and put the uncompressed data in buf.
461 *
462 * Return:
463 * 0 - success
464 * errnum - failure
465 */
466 static int
zio_read(blkptr_t * bp,void * buf,char * stack)467 zio_read(blkptr_t *bp, void *buf, char *stack)
468 {
469 int lsize, psize, comp;
470 char *retbuf;
471
472 if (BP_IS_EMBEDDED(bp)) {
473 if (BPE_GET_ETYPE(bp) != BP_EMBEDDED_TYPE_DATA) {
474 grub_printf("unsupported embedded BP (type=%u)\n",
475 (int)BPE_GET_ETYPE(bp));
476 return (ERR_FSYS_CORRUPT);
477 }
478 return (decode_embedded_bp(bp, buf));
479 }
480
481 comp = BP_GET_COMPRESS(bp);
482 lsize = BP_GET_LSIZE(bp);
483 psize = BP_GET_PSIZE(bp);
484
485 if ((unsigned int)comp >= ZIO_COMPRESS_FUNCTIONS ||
486 (comp != ZIO_COMPRESS_OFF &&
487 decomp_table[comp].decomp_func == NULL)) {
488 grub_printf("compression algorithm not supported\n");
489 return (ERR_FSYS_CORRUPT);
490 }
491
492 if ((char *)buf < stack && ((char *)buf) + lsize > stack) {
493 grub_printf("not enough memory to fit %u bytes on stack\n",
494 lsize);
495 return (ERR_WONT_FIT);
496 }
497
498 retbuf = buf;
499 if (comp != ZIO_COMPRESS_OFF) {
500 buf = stack;
501 stack += psize;
502 }
503
504 if (zio_read_data(bp, buf, stack) != 0) {
505 grub_printf("zio_read_data failed\n");
506 return (ERR_FSYS_CORRUPT);
507 }
508
509 if (comp != ZIO_COMPRESS_OFF) {
510 if (decomp_table[comp].decomp_func(buf, retbuf, psize,
511 lsize) != 0) {
512 grub_printf("zio_read decompression failed\n");
513 return (ERR_FSYS_CORRUPT);
514 }
515 }
516
517 return (0);
518 }
519
520 /*
521 * Get the block from a block id.
522 * push the block onto the stack.
523 *
524 * Return:
525 * 0 - success
526 * errnum - failure
527 */
528 static int
dmu_read(dnode_phys_t * dn,uint64_t blkid,void * buf,char * stack)529 dmu_read(dnode_phys_t *dn, uint64_t blkid, void *buf, char *stack)
530 {
531 int idx, level;
532 blkptr_t *bp_array = dn->dn_blkptr;
533 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
534 blkptr_t *bp, *tmpbuf;
535
536 bp = (blkptr_t *)stack;
537 stack += sizeof (blkptr_t);
538
539 tmpbuf = (blkptr_t *)stack;
540 stack += 1<<dn->dn_indblkshift;
541
542 for (level = dn->dn_nlevels - 1; level >= 0; level--) {
543 idx = (blkid >> (epbs * level)) & ((1<<epbs)-1);
544 *bp = bp_array[idx];
545 if (level == 0)
546 tmpbuf = buf;
547 if (BP_IS_HOLE(bp)) {
548 grub_memset(buf, 0,
549 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT);
550 break;
551 } else if (errnum = zio_read(bp, tmpbuf, stack)) {
552 return (errnum);
553 }
554
555 bp_array = tmpbuf;
556 }
557
558 return (0);
559 }
560
561 /*
562 * mzap_lookup: Looks up property described by "name" and returns the value
563 * in "value".
564 *
565 * Return:
566 * 0 - success
567 * errnum - failure
568 */
569 static int
mzap_lookup(mzap_phys_t * zapobj,int objsize,const char * name,uint64_t * value)570 mzap_lookup(mzap_phys_t *zapobj, int objsize, const char *name,
571 uint64_t *value)
572 {
573 int i, chunks;
574 mzap_ent_phys_t *mzap_ent = zapobj->mz_chunk;
575
576 chunks = objsize / MZAP_ENT_LEN - 1;
577 for (i = 0; i < chunks; i++) {
578 if (grub_strcmp(mzap_ent[i].mze_name, name) == 0) {
579 *value = mzap_ent[i].mze_value;
580 return (0);
581 }
582 }
583
584 return (ERR_FSYS_CORRUPT);
585 }
586
587 static uint64_t
zap_hash(uint64_t salt,const char * name)588 zap_hash(uint64_t salt, const char *name)
589 {
590 static uint64_t table[256];
591 const uint8_t *cp;
592 uint8_t c;
593 uint64_t crc = salt;
594
595 if (table[128] == 0) {
596 uint64_t *ct;
597 int i, j;
598 for (i = 0; i < 256; i++) {
599 for (ct = table + i, *ct = i, j = 8; j > 0; j--)
600 *ct = (*ct >> 1) ^ (-(*ct & 1) &
601 ZFS_CRC64_POLY);
602 }
603 }
604
605 if (crc == 0 || table[128] != ZFS_CRC64_POLY) {
606 errnum = ERR_FSYS_CORRUPT;
607 return (0);
608 }
609
610 for (cp = (const uint8_t *)name; (c = *cp) != '\0'; cp++)
611 crc = (crc >> 8) ^ table[(crc ^ c) & 0xFF];
612
613 /*
614 * Only use 28 bits, since we need 4 bits in the cookie for the
615 * collision differentiator. We MUST use the high bits, since
616 * those are the ones that we first pay attention to when
617 * choosing the bucket.
618 */
619 crc &= ~((1ULL << (64 - 28)) - 1);
620
621 return (crc);
622 }
623
624 /*
625 * Only to be used on 8-bit arrays.
626 * array_len is actual len in bytes (not encoded le_value_length).
627 * buf is null-terminated.
628 */
629 static int
zap_leaf_array_equal(zap_leaf_phys_t * l,int blksft,int chunk,int array_len,const char * buf)630 zap_leaf_array_equal(zap_leaf_phys_t *l, int blksft, int chunk,
631 int array_len, const char *buf)
632 {
633 int bseen = 0;
634
635 while (bseen < array_len) {
636 struct zap_leaf_array *la =
637 &ZAP_LEAF_CHUNK(l, blksft, chunk).l_array;
638 int toread = MIN(array_len - bseen, ZAP_LEAF_ARRAY_BYTES);
639
640 if (chunk >= ZAP_LEAF_NUMCHUNKS(blksft))
641 return (0);
642
643 if (zfs_bcmp(la->la_array, buf + bseen, toread) != 0)
644 break;
645 chunk = la->la_next;
646 bseen += toread;
647 }
648 return (bseen == array_len);
649 }
650
651 /*
652 * Given a zap_leaf_phys_t, walk thru the zap leaf chunks to get the
653 * value for the property "name".
654 *
655 * Return:
656 * 0 - success
657 * errnum - failure
658 */
659 static int
zap_leaf_lookup(zap_leaf_phys_t * l,int blksft,uint64_t h,const char * name,uint64_t * value)660 zap_leaf_lookup(zap_leaf_phys_t *l, int blksft, uint64_t h,
661 const char *name, uint64_t *value)
662 {
663 uint16_t chunk;
664 struct zap_leaf_entry *le;
665
666 /* Verify if this is a valid leaf block */
667 if (l->l_hdr.lh_block_type != ZBT_LEAF)
668 return (ERR_FSYS_CORRUPT);
669 if (l->l_hdr.lh_magic != ZAP_LEAF_MAGIC)
670 return (ERR_FSYS_CORRUPT);
671
672 for (chunk = l->l_hash[LEAF_HASH(blksft, h)];
673 chunk != CHAIN_END; chunk = le->le_next) {
674
675 if (chunk >= ZAP_LEAF_NUMCHUNKS(blksft))
676 return (ERR_FSYS_CORRUPT);
677
678 le = ZAP_LEAF_ENTRY(l, blksft, chunk);
679
680 /* Verify the chunk entry */
681 if (le->le_type != ZAP_CHUNK_ENTRY)
682 return (ERR_FSYS_CORRUPT);
683
684 if (le->le_hash != h)
685 continue;
686
687 if (zap_leaf_array_equal(l, blksft, le->le_name_chunk,
688 le->le_name_length, name)) {
689
690 struct zap_leaf_array *la;
691 uint8_t *ip;
692
693 if (le->le_int_size != 8 || le->le_value_length != 1)
694 return (ERR_FSYS_CORRUPT);
695
696 /* get the uint64_t property value */
697 la = &ZAP_LEAF_CHUNK(l, blksft,
698 le->le_value_chunk).l_array;
699 ip = la->la_array;
700
701 *value = (uint64_t)ip[0] << 56 | (uint64_t)ip[1] << 48 |
702 (uint64_t)ip[2] << 40 | (uint64_t)ip[3] << 32 |
703 (uint64_t)ip[4] << 24 | (uint64_t)ip[5] << 16 |
704 (uint64_t)ip[6] << 8 | (uint64_t)ip[7];
705
706 return (0);
707 }
708 }
709
710 return (ERR_FSYS_CORRUPT);
711 }
712
713 /*
714 * Fat ZAP lookup
715 *
716 * Return:
717 * 0 - success
718 * errnum - failure
719 */
720 static int
fzap_lookup(dnode_phys_t * zap_dnode,zap_phys_t * zap,const char * name,uint64_t * value,char * stack)721 fzap_lookup(dnode_phys_t *zap_dnode, zap_phys_t *zap,
722 const char *name, uint64_t *value, char *stack)
723 {
724 zap_leaf_phys_t *l;
725 uint64_t hash, idx, blkid;
726 int blksft = zfs_log2(zap_dnode->dn_datablkszsec << DNODE_SHIFT);
727
728 /* Verify if this is a fat zap header block */
729 if (zap->zap_magic != (uint64_t)ZAP_MAGIC ||
730 zap->zap_flags != 0)
731 return (ERR_FSYS_CORRUPT);
732
733 hash = zap_hash(zap->zap_salt, name);
734 if (errnum)
735 return (errnum);
736
737 /* get block id from index */
738 if (zap->zap_ptrtbl.zt_numblks != 0) {
739 /* external pointer tables not supported */
740 return (ERR_FSYS_CORRUPT);
741 }
742 idx = ZAP_HASH_IDX(hash, zap->zap_ptrtbl.zt_shift);
743 blkid = ((uint64_t *)zap)[idx + (1<<(blksft-3-1))];
744
745 /* Get the leaf block */
746 l = (zap_leaf_phys_t *)stack;
747 stack += 1<<blksft;
748 if ((1<<blksft) < sizeof (zap_leaf_phys_t))
749 return (ERR_FSYS_CORRUPT);
750 if (errnum = dmu_read(zap_dnode, blkid, l, stack))
751 return (errnum);
752
753 return (zap_leaf_lookup(l, blksft, hash, name, value));
754 }
755
756 /*
757 * Read in the data of a zap object and find the value for a matching
758 * property name.
759 *
760 * Return:
761 * 0 - success
762 * errnum - failure
763 */
764 static int
zap_lookup(dnode_phys_t * zap_dnode,const char * name,uint64_t * val,char * stack)765 zap_lookup(dnode_phys_t *zap_dnode, const char *name, uint64_t *val,
766 char *stack)
767 {
768 uint64_t block_type;
769 int size;
770 void *zapbuf;
771
772 /* Read in the first block of the zap object data. */
773 zapbuf = stack;
774 size = zap_dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT;
775 stack += size;
776
777 if ((errnum = dmu_read(zap_dnode, 0, zapbuf, stack)) != 0)
778 return (errnum);
779
780 block_type = *((uint64_t *)zapbuf);
781
782 if (block_type == ZBT_MICRO) {
783 return (mzap_lookup(zapbuf, size, name, val));
784 } else if (block_type == ZBT_HEADER) {
785 /* this is a fat zap */
786 return (fzap_lookup(zap_dnode, zapbuf, name,
787 val, stack));
788 }
789
790 return (ERR_FSYS_CORRUPT);
791 }
792
793 typedef struct zap_attribute {
794 int za_integer_length;
795 uint64_t za_num_integers;
796 uint64_t za_first_integer;
797 char *za_name;
798 } zap_attribute_t;
799
800 typedef int (zap_cb_t)(zap_attribute_t *za, void *arg, char *stack);
801
802 static int
zap_iterate(dnode_phys_t * zap_dnode,zap_cb_t * cb,void * arg,char * stack)803 zap_iterate(dnode_phys_t *zap_dnode, zap_cb_t *cb, void *arg, char *stack)
804 {
805 uint32_t size = zap_dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT;
806 zap_attribute_t za;
807 int i;
808 mzap_phys_t *mzp = (mzap_phys_t *)stack;
809 stack += size;
810
811 if ((errnum = dmu_read(zap_dnode, 0, mzp, stack)) != 0)
812 return (errnum);
813
814 /*
815 * Iteration over fatzap objects has not yet been implemented.
816 * If we encounter a pool in which there are more features for
817 * read than can fit inside a microzap (i.e., more than 2048
818 * features for read), we can add support for fatzap iteration.
819 * For now, fail.
820 */
821 if (mzp->mz_block_type != ZBT_MICRO) {
822 grub_printf("feature information stored in fatzap, pool "
823 "version not supported\n");
824 return (1);
825 }
826
827 za.za_integer_length = 8;
828 za.za_num_integers = 1;
829 for (i = 0; i < size / MZAP_ENT_LEN - 1; i++) {
830 mzap_ent_phys_t *mzep = &mzp->mz_chunk[i];
831 int err;
832
833 za.za_first_integer = mzep->mze_value;
834 za.za_name = mzep->mze_name;
835 err = cb(&za, arg, stack);
836 if (err != 0)
837 return (err);
838 }
839
840 return (0);
841 }
842
843 /*
844 * Get the dnode of an object number from the metadnode of an object set.
845 *
846 * Input
847 * mdn - metadnode to get the object dnode
848 * objnum - object number for the object dnode
849 * type - if nonzero, object must be of this type
850 * buf - data buffer that holds the returning dnode
851 * stack - scratch area
852 *
853 * Return:
854 * 0 - success
855 * errnum - failure
856 */
857 static int
dnode_get(dnode_phys_t * mdn,uint64_t objnum,uint8_t type,dnode_phys_t * buf,char * stack)858 dnode_get(dnode_phys_t *mdn, uint64_t objnum, uint8_t type, dnode_phys_t *buf,
859 char *stack)
860 {
861 uint64_t blkid, blksz; /* the block id this object dnode is in */
862 int epbs; /* shift of number of dnodes in a block */
863 int idx; /* index within a block */
864 dnode_phys_t *dnbuf;
865
866 blksz = mdn->dn_datablkszsec << SPA_MINBLOCKSHIFT;
867 epbs = zfs_log2(blksz) - DNODE_SHIFT;
868 blkid = objnum >> epbs;
869 idx = objnum & ((1<<epbs)-1);
870
871 if (dnode_buf != NULL && dnode_mdn == mdn &&
872 objnum >= dnode_start && objnum < dnode_end) {
873 grub_memmove(buf, &dnode_buf[idx], DNODE_SIZE);
874 VERIFY_DN_TYPE(buf, type);
875 return (0);
876 }
877
878 if (dnode_buf && blksz == 1<<DNODE_BLOCK_SHIFT) {
879 dnbuf = dnode_buf;
880 dnode_mdn = mdn;
881 dnode_start = blkid << epbs;
882 dnode_end = (blkid + 1) << epbs;
883 } else {
884 dnbuf = (dnode_phys_t *)stack;
885 stack += blksz;
886 }
887
888 if (errnum = dmu_read(mdn, blkid, (char *)dnbuf, stack))
889 return (errnum);
890
891 grub_memmove(buf, &dnbuf[idx], DNODE_SIZE);
892 VERIFY_DN_TYPE(buf, type);
893
894 return (0);
895 }
896
897 /*
898 * Check if this is a special file that resides at the top
899 * dataset of the pool. Currently this is the GRUB menu,
900 * boot signature and boot signature backup.
901 * str starts with '/'.
902 */
903 static int
is_top_dataset_file(char * str)904 is_top_dataset_file(char *str)
905 {
906 char *tptr;
907
908 if ((tptr = grub_strstr(str, "menu.lst")) &&
909 (tptr[8] == '\0' || tptr[8] == ' ') &&
910 *(tptr-1) == '/')
911 return (1);
912
913 if (grub_strncmp(str, BOOTSIGN_DIR"/",
914 grub_strlen(BOOTSIGN_DIR) + 1) == 0)
915 return (1);
916
917 if (grub_strcmp(str, BOOTSIGN_BACKUP) == 0)
918 return (1);
919
920 return (0);
921 }
922
923 static int
check_feature(zap_attribute_t * za,void * arg,char * stack)924 check_feature(zap_attribute_t *za, void *arg, char *stack)
925 {
926 const char **names = arg;
927 int i;
928
929 if (za->za_first_integer == 0)
930 return (0);
931
932 for (i = 0; names[i] != NULL; i++) {
933 if (grub_strcmp(za->za_name, names[i]) == 0) {
934 return (0);
935 }
936 }
937 grub_printf("missing feature for read '%s'\n", za->za_name);
938 return (ERR_NEWER_VERSION);
939 }
940
941 /*
942 * Get the file dnode for a given file name where mdn is the meta dnode
943 * for this ZFS object set. When found, place the file dnode in dn.
944 * The 'path' argument will be mangled.
945 *
946 * Return:
947 * 0 - success
948 * errnum - failure
949 */
950 static int
dnode_get_path(dnode_phys_t * mdn,char * path,dnode_phys_t * dn,char * stack)951 dnode_get_path(dnode_phys_t *mdn, char *path, dnode_phys_t *dn,
952 char *stack)
953 {
954 uint64_t objnum, version;
955 char *cname, ch;
956
957 if (errnum = dnode_get(mdn, MASTER_NODE_OBJ, DMU_OT_MASTER_NODE,
958 dn, stack))
959 return (errnum);
960
961 if (errnum = zap_lookup(dn, ZPL_VERSION_STR, &version, stack))
962 return (errnum);
963 if (version > ZPL_VERSION)
964 return (-1);
965
966 if (errnum = zap_lookup(dn, ZFS_ROOT_OBJ, &objnum, stack))
967 return (errnum);
968
969 if (errnum = dnode_get(mdn, objnum, DMU_OT_DIRECTORY_CONTENTS,
970 dn, stack))
971 return (errnum);
972
973 /* skip leading slashes */
974 while (*path == '/')
975 path++;
976
977 while (*path && !grub_isspace(*path)) {
978
979 /* get the next component name */
980 cname = path;
981 while (*path && !grub_isspace(*path) && *path != '/')
982 path++;
983 ch = *path;
984 *path = 0; /* ensure null termination */
985
986 if (errnum = zap_lookup(dn, cname, &objnum, stack))
987 return (errnum);
988
989 objnum = ZFS_DIRENT_OBJ(objnum);
990 if (errnum = dnode_get(mdn, objnum, 0, dn, stack))
991 return (errnum);
992
993 *path = ch;
994 while (*path == '/')
995 path++;
996 }
997
998 /* We found the dnode for this file. Verify if it is a plain file. */
999 VERIFY_DN_TYPE(dn, DMU_OT_PLAIN_FILE_CONTENTS);
1000
1001 return (0);
1002 }
1003
1004 /*
1005 * Get the default 'bootfs' property value from the rootpool.
1006 *
1007 * Return:
1008 * 0 - success
1009 * errnum -failure
1010 */
1011 static int
get_default_bootfsobj(dnode_phys_t * mosmdn,uint64_t * obj,char * stack)1012 get_default_bootfsobj(dnode_phys_t *mosmdn, uint64_t *obj, char *stack)
1013 {
1014 uint64_t objnum = 0;
1015 dnode_phys_t *dn = (dnode_phys_t *)stack;
1016 stack += DNODE_SIZE;
1017
1018 if (errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT,
1019 DMU_OT_OBJECT_DIRECTORY, dn, stack))
1020 return (errnum);
1021
1022 /*
1023 * find the object number for 'pool_props', and get the dnode
1024 * of the 'pool_props'.
1025 */
1026 if (zap_lookup(dn, DMU_POOL_PROPS, &objnum, stack))
1027 return (ERR_FILESYSTEM_NOT_FOUND);
1028
1029 if (errnum = dnode_get(mosmdn, objnum, DMU_OT_POOL_PROPS, dn, stack))
1030 return (errnum);
1031
1032 if (zap_lookup(dn, ZPOOL_PROP_BOOTFS, &objnum, stack))
1033 return (ERR_FILESYSTEM_NOT_FOUND);
1034
1035 if (!objnum)
1036 return (ERR_FILESYSTEM_NOT_FOUND);
1037
1038 *obj = objnum;
1039 return (0);
1040 }
1041
1042 /*
1043 * List of pool features that the grub implementation of ZFS supports for
1044 * read. Note that features that are only required for write do not need
1045 * to be listed here since grub opens pools in read-only mode.
1046 *
1047 * When this list is updated the version number in usr/src/grub/capability
1048 * must be incremented to ensure the new grub gets installed.
1049 */
1050 static const char *spa_feature_names[] = {
1051 "org.illumos:lz4_compress",
1052 "com.delphix:hole_birth",
1053 "com.delphix:extensible_dataset",
1054 "com.delphix:embedded_data",
1055 "org.open-zfs:large_blocks",
1056 "org.illumos:sha512",
1057 NULL
1058 };
1059
1060 /*
1061 * Checks whether the MOS features that are active are supported by this
1062 * (GRUB's) implementation of ZFS.
1063 *
1064 * Return:
1065 * 0: Success.
1066 * errnum: Failure.
1067 */
1068 static int
check_mos_features(dnode_phys_t * mosmdn,char * stack)1069 check_mos_features(dnode_phys_t *mosmdn, char *stack)
1070 {
1071 uint64_t objnum;
1072 dnode_phys_t *dn;
1073 uint8_t error = 0;
1074
1075 dn = (dnode_phys_t *)stack;
1076 stack += DNODE_SIZE;
1077
1078 if ((errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT,
1079 DMU_OT_OBJECT_DIRECTORY, dn, stack)) != 0)
1080 return (errnum);
1081
1082 /*
1083 * Find the object number for 'features_for_read' and retrieve its
1084 * corresponding dnode. Note that we don't check features_for_write
1085 * because GRUB is not opening the pool for write.
1086 */
1087 if ((errnum = zap_lookup(dn, DMU_POOL_FEATURES_FOR_READ, &objnum,
1088 stack)) != 0)
1089 return (errnum);
1090
1091 if ((errnum = dnode_get(mosmdn, objnum, DMU_OTN_ZAP_METADATA,
1092 dn, stack)) != 0)
1093 return (errnum);
1094
1095 return (zap_iterate(dn, check_feature, spa_feature_names, stack));
1096 }
1097
1098 /*
1099 * Given a MOS metadnode, get the metadnode of a given filesystem name (fsname),
1100 * e.g. pool/rootfs, or a given object number (obj), e.g. the object number
1101 * of pool/rootfs.
1102 *
1103 * If no fsname and no obj are given, return the DSL_DIR metadnode.
1104 * If fsname is given, return its metadnode and its matching object number.
1105 * If only obj is given, return the metadnode for this object number.
1106 *
1107 * Return:
1108 * 0 - success
1109 * errnum - failure
1110 */
1111 static int
get_objset_mdn(dnode_phys_t * mosmdn,char * fsname,uint64_t * obj,dnode_phys_t * mdn,char * stack)1112 get_objset_mdn(dnode_phys_t *mosmdn, char *fsname, uint64_t *obj,
1113 dnode_phys_t *mdn, char *stack)
1114 {
1115 uint64_t objnum, headobj;
1116 char *cname, ch;
1117 blkptr_t *bp;
1118 objset_phys_t *osp;
1119 int issnapshot = 0;
1120 char *snapname;
1121
1122 if (fsname == NULL && obj) {
1123 headobj = *obj;
1124 goto skip;
1125 }
1126
1127 if (errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT,
1128 DMU_OT_OBJECT_DIRECTORY, mdn, stack))
1129 return (errnum);
1130
1131 if (errnum = zap_lookup(mdn, DMU_POOL_ROOT_DATASET, &objnum,
1132 stack))
1133 return (errnum);
1134
1135 if (errnum = dnode_get(mosmdn, objnum, 0, mdn, stack))
1136 return (errnum);
1137
1138 if (fsname == NULL) {
1139 headobj =
1140 ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_head_dataset_obj;
1141 goto skip;
1142 }
1143
1144 /* take out the pool name */
1145 while (*fsname && !grub_isspace(*fsname) && *fsname != '/')
1146 fsname++;
1147
1148 while (*fsname && !grub_isspace(*fsname)) {
1149 uint64_t childobj;
1150
1151 while (*fsname == '/')
1152 fsname++;
1153
1154 cname = fsname;
1155 while (*fsname && !grub_isspace(*fsname) && *fsname != '/')
1156 fsname++;
1157 ch = *fsname;
1158 *fsname = 0;
1159
1160 snapname = cname;
1161 while (*snapname && !grub_isspace(*snapname) && *snapname !=
1162 '@')
1163 snapname++;
1164 if (*snapname == '@') {
1165 issnapshot = 1;
1166 *snapname = 0;
1167 }
1168 childobj =
1169 ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_child_dir_zapobj;
1170 if (errnum = dnode_get(mosmdn, childobj,
1171 DMU_OT_DSL_DIR_CHILD_MAP, mdn, stack))
1172 return (errnum);
1173
1174 if (zap_lookup(mdn, cname, &objnum, stack))
1175 return (ERR_FILESYSTEM_NOT_FOUND);
1176
1177 if (errnum = dnode_get(mosmdn, objnum, 0,
1178 mdn, stack))
1179 return (errnum);
1180
1181 *fsname = ch;
1182 if (issnapshot)
1183 *snapname = '@';
1184 }
1185 headobj = ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_head_dataset_obj;
1186 if (obj)
1187 *obj = headobj;
1188
1189 skip:
1190 if (errnum = dnode_get(mosmdn, headobj, 0, mdn, stack))
1191 return (errnum);
1192 if (issnapshot) {
1193 uint64_t snapobj;
1194
1195 snapobj = ((dsl_dataset_phys_t *)DN_BONUS(mdn))->
1196 ds_snapnames_zapobj;
1197
1198 if (errnum = dnode_get(mosmdn, snapobj,
1199 DMU_OT_DSL_DS_SNAP_MAP, mdn, stack))
1200 return (errnum);
1201 if (zap_lookup(mdn, snapname + 1, &headobj, stack))
1202 return (ERR_FILESYSTEM_NOT_FOUND);
1203 if (errnum = dnode_get(mosmdn, headobj, 0, mdn, stack))
1204 return (errnum);
1205 if (obj)
1206 *obj = headobj;
1207 }
1208
1209 bp = &((dsl_dataset_phys_t *)DN_BONUS(mdn))->ds_bp;
1210 osp = (objset_phys_t *)stack;
1211 stack += sizeof (objset_phys_t);
1212 if (errnum = zio_read(bp, osp, stack))
1213 return (errnum);
1214
1215 grub_memmove((char *)mdn, (char *)&osp->os_meta_dnode, DNODE_SIZE);
1216
1217 return (0);
1218 }
1219
1220 /*
1221 * For a given XDR packed nvlist, verify the first 4 bytes and move on.
1222 *
1223 * An XDR packed nvlist is encoded as (comments from nvs_xdr_create) :
1224 *
1225 * encoding method/host endian (4 bytes)
1226 * nvl_version (4 bytes)
1227 * nvl_nvflag (4 bytes)
1228 * encoded nvpairs:
1229 * encoded size of the nvpair (4 bytes)
1230 * decoded size of the nvpair (4 bytes)
1231 * name string size (4 bytes)
1232 * name string data (sizeof(NV_ALIGN4(string))
1233 * data type (4 bytes)
1234 * # of elements in the nvpair (4 bytes)
1235 * data
1236 * 2 zero's for the last nvpair
1237 * (end of the entire list) (8 bytes)
1238 *
1239 * Return:
1240 * 0 - success
1241 * 1 - failure
1242 */
1243 static int
nvlist_unpack(char * nvlist,char ** out)1244 nvlist_unpack(char *nvlist, char **out)
1245 {
1246 /* Verify if the 1st and 2nd byte in the nvlist are valid. */
1247 if (nvlist[0] != NV_ENCODE_XDR || nvlist[1] != HOST_ENDIAN)
1248 return (1);
1249
1250 *out = nvlist + 4;
1251 return (0);
1252 }
1253
1254 static char *
nvlist_array(char * nvlist,int index)1255 nvlist_array(char *nvlist, int index)
1256 {
1257 int i, encode_size;
1258
1259 for (i = 0; i < index; i++) {
1260 /* skip the header, nvl_version, and nvl_nvflag */
1261 nvlist = nvlist + 4 * 2;
1262
1263 while (encode_size = BSWAP_32(*(uint32_t *)nvlist))
1264 nvlist += encode_size; /* goto the next nvpair */
1265
1266 nvlist = nvlist + 4 * 2; /* skip the ending 2 zeros - 8 bytes */
1267 }
1268
1269 return (nvlist);
1270 }
1271
1272 /*
1273 * The nvlist_next_nvpair() function returns a handle to the next nvpair in the
1274 * list following nvpair. If nvpair is NULL, the first pair is returned. If
1275 * nvpair is the last pair in the nvlist, NULL is returned.
1276 */
1277 static char *
nvlist_next_nvpair(char * nvl,char * nvpair)1278 nvlist_next_nvpair(char *nvl, char *nvpair)
1279 {
1280 char *cur, *prev;
1281 int encode_size;
1282
1283 if (nvl == NULL)
1284 return (NULL);
1285
1286 if (nvpair == NULL) {
1287 /* skip over nvl_version and nvl_nvflag */
1288 nvpair = nvl + 4 * 2;
1289 } else {
1290 /* skip to the next nvpair */
1291 encode_size = BSWAP_32(*(uint32_t *)nvpair);
1292 nvpair += encode_size;
1293 }
1294
1295 /* 8 bytes of 0 marks the end of the list */
1296 if (*(uint64_t *)nvpair == 0)
1297 return (NULL);
1298
1299 return (nvpair);
1300 }
1301
1302 /*
1303 * This function returns 0 on success and 1 on failure. On success, a string
1304 * containing the name of nvpair is saved in buf.
1305 */
1306 static int
nvpair_name(char * nvp,char * buf,int buflen)1307 nvpair_name(char *nvp, char *buf, int buflen)
1308 {
1309 int len;
1310
1311 /* skip over encode/decode size */
1312 nvp += 4 * 2;
1313
1314 len = BSWAP_32(*(uint32_t *)nvp);
1315 if (buflen < len + 1)
1316 return (1);
1317
1318 grub_memmove(buf, nvp + 4, len);
1319 buf[len] = '\0';
1320
1321 return (0);
1322 }
1323
1324 /*
1325 * This function retrieves the value of the nvpair in the form of enumerated
1326 * type data_type_t. This is used to determine the appropriate type to pass to
1327 * nvpair_value().
1328 */
1329 static int
nvpair_type(char * nvp)1330 nvpair_type(char *nvp)
1331 {
1332 int name_len, type;
1333
1334 /* skip over encode/decode size */
1335 nvp += 4 * 2;
1336
1337 /* skip over name_len */
1338 name_len = BSWAP_32(*(uint32_t *)nvp);
1339 nvp += 4;
1340
1341 /* skip over name */
1342 nvp = nvp + ((name_len + 3) & ~3); /* align */
1343
1344 type = BSWAP_32(*(uint32_t *)nvp);
1345
1346 return (type);
1347 }
1348
1349 static int
nvpair_value(char * nvp,void * val,int valtype,int * nelmp)1350 nvpair_value(char *nvp, void *val, int valtype, int *nelmp)
1351 {
1352 int name_len, type, slen;
1353 char *strval = val;
1354 uint64_t *intval = val;
1355
1356 /* skip over encode/decode size */
1357 nvp += 4 * 2;
1358
1359 /* skip over name_len */
1360 name_len = BSWAP_32(*(uint32_t *)nvp);
1361 nvp += 4;
1362
1363 /* skip over name */
1364 nvp = nvp + ((name_len + 3) & ~3); /* align */
1365
1366 /* skip over type */
1367 type = BSWAP_32(*(uint32_t *)nvp);
1368 nvp += 4;
1369
1370 if (type == valtype) {
1371 int nelm;
1372
1373 nelm = BSWAP_32(*(uint32_t *)nvp);
1374 if (valtype != DATA_TYPE_BOOLEAN && nelm < 1)
1375 return (1);
1376 nvp += 4;
1377
1378 switch (valtype) {
1379 case DATA_TYPE_BOOLEAN:
1380 return (0);
1381
1382 case DATA_TYPE_STRING:
1383 slen = BSWAP_32(*(uint32_t *)nvp);
1384 nvp += 4;
1385 grub_memmove(strval, nvp, slen);
1386 strval[slen] = '\0';
1387 return (0);
1388
1389 case DATA_TYPE_UINT64:
1390 *intval = BSWAP_64(*(uint64_t *)nvp);
1391 return (0);
1392
1393 case DATA_TYPE_NVLIST:
1394 *(void **)val = (void *)nvp;
1395 return (0);
1396
1397 case DATA_TYPE_NVLIST_ARRAY:
1398 *(void **)val = (void *)nvp;
1399 if (nelmp)
1400 *nelmp = nelm;
1401 return (0);
1402 }
1403 }
1404
1405 return (1);
1406 }
1407
1408 static int
nvlist_lookup_value(char * nvlist,char * name,void * val,int valtype,int * nelmp)1409 nvlist_lookup_value(char *nvlist, char *name, void *val, int valtype,
1410 int *nelmp)
1411 {
1412 char *nvpair;
1413
1414 for (nvpair = nvlist_next_nvpair(nvlist, NULL);
1415 nvpair != NULL;
1416 nvpair = nvlist_next_nvpair(nvlist, nvpair)) {
1417 int name_len = BSWAP_32(*(uint32_t *)(nvpair + 4 * 2));
1418 char *nvp_name = nvpair + 4 * 3;
1419
1420 if ((grub_strncmp(nvp_name, name, name_len) == 0) &&
1421 nvpair_type(nvpair) == valtype) {
1422 return (nvpair_value(nvpair, val, valtype, nelmp));
1423 }
1424 }
1425 return (1);
1426 }
1427
1428 /*
1429 * Check if this vdev is online and is in a good state.
1430 */
1431 static int
vdev_validate(char * nv)1432 vdev_validate(char *nv)
1433 {
1434 uint64_t ival;
1435
1436 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_OFFLINE, &ival,
1437 DATA_TYPE_UINT64, NULL) == 0 ||
1438 nvlist_lookup_value(nv, ZPOOL_CONFIG_FAULTED, &ival,
1439 DATA_TYPE_UINT64, NULL) == 0 ||
1440 nvlist_lookup_value(nv, ZPOOL_CONFIG_REMOVED, &ival,
1441 DATA_TYPE_UINT64, NULL) == 0)
1442 return (ERR_DEV_VALUES);
1443
1444 return (0);
1445 }
1446
1447 /*
1448 * Get a valid vdev pathname/devid from the boot device.
1449 * The caller should already allocate MAXPATHLEN memory for bootpath and devid.
1450 */
1451 static int
vdev_get_bootpath(char * nv,uint64_t inguid,char * devid,char * bootpath,int is_spare)1452 vdev_get_bootpath(char *nv, uint64_t inguid, char *devid, char *bootpath,
1453 int is_spare)
1454 {
1455 char type[16];
1456
1457 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_TYPE, &type, DATA_TYPE_STRING,
1458 NULL))
1459 return (ERR_FSYS_CORRUPT);
1460
1461 if (grub_strcmp(type, VDEV_TYPE_DISK) == 0) {
1462 uint64_t guid;
1463
1464 if (vdev_validate(nv) != 0)
1465 return (ERR_NO_BOOTPATH);
1466
1467 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_GUID,
1468 &guid, DATA_TYPE_UINT64, NULL) != 0)
1469 return (ERR_NO_BOOTPATH);
1470
1471 if (guid != inguid)
1472 return (ERR_NO_BOOTPATH);
1473
1474 /* for a spare vdev, pick the disk labeled with "is_spare" */
1475 if (is_spare) {
1476 uint64_t spare = 0;
1477 (void) nvlist_lookup_value(nv, ZPOOL_CONFIG_IS_SPARE,
1478 &spare, DATA_TYPE_UINT64, NULL);
1479 if (!spare)
1480 return (ERR_NO_BOOTPATH);
1481 }
1482
1483 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_PHYS_PATH,
1484 bootpath, DATA_TYPE_STRING, NULL) != 0)
1485 bootpath[0] = '\0';
1486
1487 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_DEVID,
1488 devid, DATA_TYPE_STRING, NULL) != 0)
1489 devid[0] = '\0';
1490
1491 if (grub_strlen(bootpath) >= MAXPATHLEN ||
1492 grub_strlen(devid) >= MAXPATHLEN)
1493 return (ERR_WONT_FIT);
1494
1495 return (0);
1496
1497 } else if (grub_strcmp(type, VDEV_TYPE_MIRROR) == 0 ||
1498 grub_strcmp(type, VDEV_TYPE_REPLACING) == 0 ||
1499 (is_spare = (grub_strcmp(type, VDEV_TYPE_SPARE) == 0))) {
1500 int nelm, i;
1501 char *child;
1502
1503 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_CHILDREN, &child,
1504 DATA_TYPE_NVLIST_ARRAY, &nelm))
1505 return (ERR_FSYS_CORRUPT);
1506
1507 for (i = 0; i < nelm; i++) {
1508 char *child_i;
1509
1510 child_i = nvlist_array(child, i);
1511 if (vdev_get_bootpath(child_i, inguid, devid,
1512 bootpath, is_spare) == 0)
1513 return (0);
1514 }
1515 }
1516
1517 return (ERR_NO_BOOTPATH);
1518 }
1519
1520 /*
1521 * Check the disk label information and retrieve needed vdev name-value pairs.
1522 *
1523 * Return:
1524 * 0 - success
1525 * ERR_* - failure
1526 */
1527 static int
check_pool_label(uint64_t sector,char * stack,char * outdevid,char * outpath,uint64_t * outguid,uint64_t * outashift,uint64_t * outversion)1528 check_pool_label(uint64_t sector, char *stack, char *outdevid,
1529 char *outpath, uint64_t *outguid, uint64_t *outashift, uint64_t *outversion)
1530 {
1531 vdev_phys_t *vdev;
1532 uint64_t pool_state, txg = 0;
1533 char *nvlist, *nv, *features;
1534 uint64_t diskguid;
1535
1536 sector += (VDEV_SKIP_SIZE >> SPA_MINBLOCKSHIFT);
1537
1538 /* Read in the vdev name-value pair list (112K). */
1539 if (devread(sector, 0, VDEV_PHYS_SIZE, stack) == 0)
1540 return (ERR_READ);
1541
1542 vdev = (vdev_phys_t *)stack;
1543 stack += sizeof (vdev_phys_t);
1544
1545 if (nvlist_unpack(vdev->vp_nvlist, &nvlist))
1546 return (ERR_FSYS_CORRUPT);
1547
1548 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_STATE, &pool_state,
1549 DATA_TYPE_UINT64, NULL))
1550 return (ERR_FSYS_CORRUPT);
1551
1552 if (pool_state == POOL_STATE_DESTROYED)
1553 return (ERR_FILESYSTEM_NOT_FOUND);
1554
1555 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_NAME,
1556 current_rootpool, DATA_TYPE_STRING, NULL))
1557 return (ERR_FSYS_CORRUPT);
1558
1559 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_TXG, &txg,
1560 DATA_TYPE_UINT64, NULL))
1561 return (ERR_FSYS_CORRUPT);
1562
1563 /* not an active device */
1564 if (txg == 0)
1565 return (ERR_NO_BOOTPATH);
1566
1567 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_VERSION, outversion,
1568 DATA_TYPE_UINT64, NULL))
1569 return (ERR_FSYS_CORRUPT);
1570 if (!SPA_VERSION_IS_SUPPORTED(*outversion))
1571 return (ERR_NEWER_VERSION);
1572 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_VDEV_TREE, &nv,
1573 DATA_TYPE_NVLIST, NULL))
1574 return (ERR_FSYS_CORRUPT);
1575 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_GUID, &diskguid,
1576 DATA_TYPE_UINT64, NULL))
1577 return (ERR_FSYS_CORRUPT);
1578 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_ASHIFT, outashift,
1579 DATA_TYPE_UINT64, NULL) != 0)
1580 return (ERR_FSYS_CORRUPT);
1581 if (vdev_get_bootpath(nv, diskguid, outdevid, outpath, 0))
1582 return (ERR_NO_BOOTPATH);
1583 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_GUID, outguid,
1584 DATA_TYPE_UINT64, NULL))
1585 return (ERR_FSYS_CORRUPT);
1586
1587 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_FEATURES_FOR_READ,
1588 &features, DATA_TYPE_NVLIST, NULL) == 0) {
1589 char *nvp;
1590 char *name = stack;
1591 stack += MAXNAMELEN;
1592
1593 for (nvp = nvlist_next_nvpair(features, NULL);
1594 nvp != NULL;
1595 nvp = nvlist_next_nvpair(features, nvp)) {
1596 zap_attribute_t za;
1597
1598 if (nvpair_name(nvp, name, MAXNAMELEN) != 0)
1599 return (ERR_FSYS_CORRUPT);
1600
1601 za.za_integer_length = 8;
1602 za.za_num_integers = 1;
1603 za.za_first_integer = 1;
1604 za.za_name = name;
1605 if (check_feature(&za, spa_feature_names, stack) != 0)
1606 return (ERR_NEWER_VERSION);
1607 }
1608 }
1609
1610 return (0);
1611 }
1612
1613 /*
1614 * zfs_mount() locates a valid uberblock of the root pool and read in its MOS
1615 * to the memory address MOS.
1616 *
1617 * Return:
1618 * 1 - success
1619 * 0 - failure
1620 */
1621 int
zfs_mount(void)1622 zfs_mount(void)
1623 {
1624 char *stack, *ub_array;
1625 int label = 0;
1626 uberblock_t *ubbest;
1627 objset_phys_t *osp;
1628 char tmp_bootpath[MAXNAMELEN];
1629 char tmp_devid[MAXNAMELEN];
1630 uint64_t tmp_guid, ashift, version;
1631 uint64_t adjpl = (uint64_t)part_length << SPA_MINBLOCKSHIFT;
1632 int err = errnum; /* preserve previous errnum state */
1633
1634 /* if it's our first time here, zero the best uberblock out */
1635 if (best_drive == 0 && best_part == 0 && find_best_root) {
1636 grub_memset(¤t_uberblock, 0, sizeof (uberblock_t));
1637 pool_guid = 0;
1638 }
1639
1640 stackbase = ZFS_SCRATCH;
1641 stack = stackbase;
1642 ub_array = stack;
1643 stack += VDEV_UBERBLOCK_RING;
1644
1645 osp = (objset_phys_t *)stack;
1646 stack += sizeof (objset_phys_t);
1647 adjpl = P2ALIGN(adjpl, (uint64_t)sizeof (vdev_label_t));
1648
1649 for (label = 0; label < VDEV_LABELS; label++) {
1650
1651 /*
1652 * some eltorito stacks don't give us a size and
1653 * we end up setting the size to MAXUINT, further
1654 * some of these devices stop working once a single
1655 * read past the end has been issued. Checking
1656 * for a maximum part_length and skipping the backup
1657 * labels at the end of the slice/partition/device
1658 * avoids breaking down on such devices.
1659 */
1660 if (part_length == MAXUINT && label == 2)
1661 break;
1662
1663 uint64_t sector = vdev_label_start(adjpl,
1664 label) >> SPA_MINBLOCKSHIFT;
1665
1666 /* Read in the uberblock ring (128K). */
1667 if (devread(sector +
1668 ((VDEV_SKIP_SIZE + VDEV_PHYS_SIZE) >> SPA_MINBLOCKSHIFT),
1669 0, VDEV_UBERBLOCK_RING, ub_array) == 0)
1670 continue;
1671
1672 if (check_pool_label(sector, stack, tmp_devid,
1673 tmp_bootpath, &tmp_guid, &ashift, &version))
1674 continue;
1675
1676 if (pool_guid == 0)
1677 pool_guid = tmp_guid;
1678
1679 if ((ubbest = find_bestub(ub_array, ashift, sector)) == NULL ||
1680 zio_read(&ubbest->ub_rootbp, osp, stack) != 0)
1681 continue;
1682
1683 VERIFY_OS_TYPE(osp, DMU_OST_META);
1684
1685 if (version >= SPA_VERSION_FEATURES &&
1686 check_mos_features(&osp->os_meta_dnode, stack) != 0)
1687 continue;
1688
1689 if (find_best_root && ((pool_guid != tmp_guid) ||
1690 vdev_uberblock_compare(ubbest, &(current_uberblock)) <= 0))
1691 continue;
1692
1693 /* Got the MOS. Save it at the memory addr MOS. */
1694 grub_memmove(MOS, &osp->os_meta_dnode, DNODE_SIZE);
1695 grub_memmove(¤t_uberblock, ubbest, sizeof (uberblock_t));
1696 grub_memmove(current_bootpath, tmp_bootpath, MAXNAMELEN);
1697 grub_memmove(current_devid, tmp_devid, grub_strlen(tmp_devid));
1698 is_zfs_mount = 1;
1699 return (1);
1700 }
1701
1702 /*
1703 * While some fs impls. (tftp) rely on setting and keeping
1704 * global errnums set, others won't reset it and will break
1705 * when issuing rawreads. The goal here is to simply not
1706 * have zfs mount attempts impact the previous state.
1707 */
1708 errnum = err;
1709 return (0);
1710 }
1711
1712 /*
1713 * zfs_open() locates a file in the rootpool by following the
1714 * MOS and places the dnode of the file in the memory address DNODE.
1715 *
1716 * Return:
1717 * 1 - success
1718 * 0 - failure
1719 */
1720 int
zfs_open(char * filename)1721 zfs_open(char *filename)
1722 {
1723 char *stack;
1724 dnode_phys_t *mdn;
1725
1726 file_buf = NULL;
1727 stackbase = ZFS_SCRATCH;
1728 stack = stackbase;
1729
1730 mdn = (dnode_phys_t *)stack;
1731 stack += sizeof (dnode_phys_t);
1732
1733 dnode_mdn = NULL;
1734 dnode_buf = (dnode_phys_t *)stack;
1735 stack += 1<<DNODE_BLOCK_SHIFT;
1736
1737 /*
1738 * menu.lst is placed at the root pool filesystem level,
1739 * do not goto 'current_bootfs'.
1740 */
1741 if (is_top_dataset_file(filename)) {
1742 if (errnum = get_objset_mdn(MOS, NULL, NULL, mdn, stack))
1743 return (0);
1744
1745 current_bootfs_obj = 0;
1746 } else {
1747 if (current_bootfs[0] == '\0') {
1748 /* Get the default root filesystem object number */
1749 if (errnum = get_default_bootfsobj(MOS,
1750 ¤t_bootfs_obj, stack))
1751 return (0);
1752
1753 if (errnum = get_objset_mdn(MOS, NULL,
1754 ¤t_bootfs_obj, mdn, stack))
1755 return (0);
1756 } else {
1757 if (errnum = get_objset_mdn(MOS, current_bootfs,
1758 ¤t_bootfs_obj, mdn, stack)) {
1759 grub_memset(current_bootfs, 0, MAXNAMELEN);
1760 return (0);
1761 }
1762 }
1763 }
1764
1765 if (dnode_get_path(mdn, filename, DNODE, stack)) {
1766 errnum = ERR_FILE_NOT_FOUND;
1767 return (0);
1768 }
1769
1770 /* get the file size and set the file position to 0 */
1771
1772 /*
1773 * For DMU_OT_SA we will need to locate the SIZE attribute
1774 * attribute, which could be either in the bonus buffer
1775 * or the "spill" block.
1776 */
1777 if (DNODE->dn_bonustype == DMU_OT_SA) {
1778 sa_hdr_phys_t *sahdrp;
1779 int hdrsize;
1780
1781 if (DNODE->dn_bonuslen != 0) {
1782 sahdrp = (sa_hdr_phys_t *)DN_BONUS(DNODE);
1783 } else {
1784 if (DNODE->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
1785 blkptr_t *bp = &DNODE->dn_spill;
1786 void *buf;
1787
1788 buf = (void *)stack;
1789 stack += BP_GET_LSIZE(bp);
1790
1791 /* reset errnum to rawread() failure */
1792 errnum = 0;
1793 if (zio_read(bp, buf, stack) != 0) {
1794 return (0);
1795 }
1796 sahdrp = buf;
1797 } else {
1798 errnum = ERR_FSYS_CORRUPT;
1799 return (0);
1800 }
1801 }
1802 hdrsize = SA_HDR_SIZE(sahdrp);
1803 filemax = *(uint64_t *)((char *)sahdrp + hdrsize +
1804 SA_SIZE_OFFSET);
1805 } else {
1806 filemax = ((znode_phys_t *)DN_BONUS(DNODE))->zp_size;
1807 }
1808 filepos = 0;
1809
1810 dnode_buf = NULL;
1811 return (1);
1812 }
1813
1814 /*
1815 * zfs_read reads in the data blocks pointed by the DNODE.
1816 *
1817 * Return:
1818 * len - the length successfully read in to the buffer
1819 * 0 - failure
1820 */
1821 int
zfs_read(char * buf,int len)1822 zfs_read(char *buf, int len)
1823 {
1824 char *stack;
1825 int blksz, length, movesize;
1826
1827 if (file_buf == NULL) {
1828 file_buf = stackbase;
1829 stackbase += SPA_MAXBLOCKSIZE;
1830 file_start = file_end = 0;
1831 }
1832 stack = stackbase;
1833
1834 /*
1835 * If offset is in memory, move it into the buffer provided and return.
1836 */
1837 if (filepos >= file_start && filepos+len <= file_end) {
1838 grub_memmove(buf, file_buf + filepos - file_start, len);
1839 filepos += len;
1840 return (len);
1841 }
1842
1843 blksz = DNODE->dn_datablkszsec << SPA_MINBLOCKSHIFT;
1844
1845 /*
1846 * Note: for GRUB, SPA_MAXBLOCKSIZE is 128KB. There is not enough
1847 * memory to allocate the new max blocksize (16MB), so while
1848 * GRUB understands the large_blocks on-disk feature, it can't
1849 * actually read large blocks.
1850 */
1851 if (blksz > SPA_MAXBLOCKSIZE) {
1852 grub_printf("blocks larger than 128K are not supported\n");
1853 return (0);
1854 }
1855
1856 /*
1857 * Entire Dnode is too big to fit into the space available. We
1858 * will need to read it in chunks. This could be optimized to
1859 * read in as large a chunk as there is space available, but for
1860 * now, this only reads in one data block at a time.
1861 */
1862 length = len;
1863 while (length) {
1864 /*
1865 * Find requested blkid and the offset within that block.
1866 */
1867 uint64_t blkid = filepos / blksz;
1868
1869 if (errnum = dmu_read(DNODE, blkid, file_buf, stack))
1870 return (0);
1871
1872 file_start = blkid * blksz;
1873 file_end = file_start + blksz;
1874
1875 movesize = MIN(length, file_end - filepos);
1876
1877 grub_memmove(buf, file_buf + filepos - file_start,
1878 movesize);
1879 buf += movesize;
1880 length -= movesize;
1881 filepos += movesize;
1882 }
1883
1884 return (len);
1885 }
1886
1887 /*
1888 * No-Op
1889 */
1890 int
zfs_embed(int * start_sector,int needed_sectors)1891 zfs_embed(int *start_sector, int needed_sectors)
1892 {
1893 return (1);
1894 }
1895
1896 #endif /* FSYS_ZFS */
1897