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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4 * Copyright (c) 2013 Red Hat, Inc.
5 * All Rights Reserved.
6 */
7#include "xfs.h"
8#include "xfs_fs.h"
9#include "xfs_shared.h"
10#include "xfs_format.h"
11#include "xfs_log_format.h"
12#include "xfs_trans_resv.h"
13#include "xfs_mount.h"
14#include "xfs_da_format.h"
15#include "xfs_inode.h"
16#include "xfs_trans.h"
17#include "xfs_bmap.h"
18#include "xfs_attr.h"
19#include "xfs_attr_sf.h"
20#include "xfs_attr_leaf.h"
21#include "xfs_error.h"
22#include "xfs_trace.h"
23#include "xfs_dir2.h"
24
25STATIC int
26xfs_attr_shortform_compare(const void *a, const void *b)
27{
28 xfs_attr_sf_sort_t *sa, *sb;
29
30 sa = (xfs_attr_sf_sort_t *)a;
31 sb = (xfs_attr_sf_sort_t *)b;
32 if (sa->hash < sb->hash) {
33 return -1;
34 } else if (sa->hash > sb->hash) {
35 return 1;
36 } else {
37 return sa->entno - sb->entno;
38 }
39}
40
41#define XFS_ISRESET_CURSOR(cursor) \
42 (!((cursor)->initted) && !((cursor)->hashval) && \
43 !((cursor)->blkno) && !((cursor)->offset))
44/*
45 * Copy out entries of shortform attribute lists for attr_list().
46 * Shortform attribute lists are not stored in hashval sorted order.
47 * If the output buffer is not large enough to hold them all, then we
48 * we have to calculate each entries' hashvalue and sort them before
49 * we can begin returning them to the user.
50 */
51static int
52xfs_attr_shortform_list(xfs_attr_list_context_t *context)
53{
54 attrlist_cursor_kern_t *cursor;
55 xfs_attr_sf_sort_t *sbuf, *sbp;
56 xfs_attr_shortform_t *sf;
57 xfs_attr_sf_entry_t *sfe;
58 xfs_inode_t *dp;
59 int sbsize, nsbuf, count, i;
60
61 ASSERT(context != NULL);
62 dp = context->dp;
63 ASSERT(dp != NULL);
64 ASSERT(dp->i_afp != NULL);
65 sf = (xfs_attr_shortform_t *)dp->i_afp->if_u1.if_data;
66 ASSERT(sf != NULL);
67 if (!sf->hdr.count)
68 return 0;
69 cursor = context->cursor;
70 ASSERT(cursor != NULL);
71
72 trace_xfs_attr_list_sf(context);
73
74 /*
75 * If the buffer is large enough and the cursor is at the start,
76 * do not bother with sorting since we will return everything in
77 * one buffer and another call using the cursor won't need to be
78 * made.
79 * Note the generous fudge factor of 16 overhead bytes per entry.
80 * If bufsize is zero then put_listent must be a search function
81 * and can just scan through what we have.
82 */
83 if (context->bufsize == 0 ||
84 (XFS_ISRESET_CURSOR(cursor) &&
85 (dp->i_afp->if_bytes + sf->hdr.count * 16) < context->bufsize)) {
86 for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
87 context->put_listent(context,
88 sfe->flags,
89 sfe->nameval,
90 (int)sfe->namelen,
91 (int)sfe->valuelen);
92 /*
93 * Either search callback finished early or
94 * didn't fit it all in the buffer after all.
95 */
96 if (context->seen_enough)
97 break;
98 sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
99 }
100 trace_xfs_attr_list_sf_all(context);
101 return 0;
102 }
103
104 /* do no more for a search callback */
105 if (context->bufsize == 0)
106 return 0;
107
108 /*
109 * It didn't all fit, so we have to sort everything on hashval.
110 */
111 sbsize = sf->hdr.count * sizeof(*sbuf);
112 sbp = sbuf = kmem_alloc(sbsize, KM_NOFS);
113
114 /*
115 * Scan the attribute list for the rest of the entries, storing
116 * the relevant info from only those that match into a buffer.
117 */
118 nsbuf = 0;
119 for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
120 if (unlikely(
121 ((char *)sfe < (char *)sf) ||
122 ((char *)sfe >= ((char *)sf + dp->i_afp->if_bytes)))) {
123 XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
124 XFS_ERRLEVEL_LOW,
125 context->dp->i_mount, sfe,
126 sizeof(*sfe));
127 kmem_free(sbuf);
128 return -EFSCORRUPTED;
129 }
130
131 sbp->entno = i;
132 sbp->hash = xfs_da_hashname(sfe->nameval, sfe->namelen);
133 sbp->name = sfe->nameval;
134 sbp->namelen = sfe->namelen;
135 /* These are bytes, and both on-disk, don't endian-flip */
136 sbp->valuelen = sfe->valuelen;
137 sbp->flags = sfe->flags;
138 sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
139 sbp++;
140 nsbuf++;
141 }
142
143 /*
144 * Sort the entries on hash then entno.
145 */
146 xfs_sort(sbuf, nsbuf, sizeof(*sbuf), xfs_attr_shortform_compare);
147
148 /*
149 * Re-find our place IN THE SORTED LIST.
150 */
151 count = 0;
152 cursor->initted = 1;
153 cursor->blkno = 0;
154 for (sbp = sbuf, i = 0; i < nsbuf; i++, sbp++) {
155 if (sbp->hash == cursor->hashval) {
156 if (cursor->offset == count) {
157 break;
158 }
159 count++;
160 } else if (sbp->hash > cursor->hashval) {
161 break;
162 }
163 }
164 if (i == nsbuf) {
165 kmem_free(sbuf);
166 return 0;
167 }
168
169 /*
170 * Loop putting entries into the user buffer.
171 */
172 for ( ; i < nsbuf; i++, sbp++) {
173 if (cursor->hashval != sbp->hash) {
174 cursor->hashval = sbp->hash;
175 cursor->offset = 0;
176 }
177 context->put_listent(context,
178 sbp->flags,
179 sbp->name,
180 sbp->namelen,
181 sbp->valuelen);
182 if (context->seen_enough)
183 break;
184 cursor->offset++;
185 }
186
187 kmem_free(sbuf);
188 return 0;
189}
190
191/*
192 * We didn't find the block & hash mentioned in the cursor state, so
193 * walk down the attr btree looking for the hash.
194 */
195STATIC int
196xfs_attr_node_list_lookup(
197 struct xfs_attr_list_context *context,
198 struct attrlist_cursor_kern *cursor,
199 struct xfs_buf **pbp)
200{
201 struct xfs_da3_icnode_hdr nodehdr;
202 struct xfs_da_intnode *node;
203 struct xfs_da_node_entry *btree;
204 struct xfs_inode *dp = context->dp;
205 struct xfs_mount *mp = dp->i_mount;
206 struct xfs_trans *tp = context->tp;
207 struct xfs_buf *bp;
208 int i;
209 int error = 0;
210 unsigned int expected_level = 0;
211 uint16_t magic;
212
213 ASSERT(*pbp == NULL);
214 cursor->blkno = 0;
215 for (;;) {
216 error = xfs_da3_node_read(tp, dp, cursor->blkno, -1, &bp,
217 XFS_ATTR_FORK);
218 if (error)
219 return error;
220 node = bp->b_addr;
221 magic = be16_to_cpu(node->hdr.info.magic);
222 if (magic == XFS_ATTR_LEAF_MAGIC ||
223 magic == XFS_ATTR3_LEAF_MAGIC)
224 break;
225 if (magic != XFS_DA_NODE_MAGIC &&
226 magic != XFS_DA3_NODE_MAGIC) {
227 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
228 node, sizeof(*node));
229 goto out_corruptbuf;
230 }
231
232 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
233
234 /* Tree taller than we can handle; bail out! */
235 if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH)
236 goto out_corruptbuf;
237
238 /* Check the level from the root node. */
239 if (cursor->blkno == 0)
240 expected_level = nodehdr.level - 1;
241 else if (expected_level != nodehdr.level)
242 goto out_corruptbuf;
243 else
244 expected_level--;
245
246 btree = dp->d_ops->node_tree_p(node);
247 for (i = 0; i < nodehdr.count; btree++, i++) {
248 if (cursor->hashval <= be32_to_cpu(btree->hashval)) {
249 cursor->blkno = be32_to_cpu(btree->before);
250 trace_xfs_attr_list_node_descend(context,
251 btree);
252 break;
253 }
254 }
255 xfs_trans_brelse(tp, bp);
256
257 if (i == nodehdr.count)
258 return 0;
259
260 /* We can't point back to the root. */
261 if (cursor->blkno == 0)
262 return -EFSCORRUPTED;
263 }
264
265 if (expected_level != 0)
266 goto out_corruptbuf;
267
268 *pbp = bp;
269 return 0;
270
271out_corruptbuf:
272 xfs_trans_brelse(tp, bp);
273 return -EFSCORRUPTED;
274}
275
276STATIC int
277xfs_attr_node_list(
278 struct xfs_attr_list_context *context)
279{
280 struct xfs_attr3_icleaf_hdr leafhdr;
281 struct attrlist_cursor_kern *cursor;
282 struct xfs_attr_leafblock *leaf;
283 struct xfs_da_intnode *node;
284 struct xfs_buf *bp;
285 struct xfs_inode *dp = context->dp;
286 struct xfs_mount *mp = dp->i_mount;
287 int error;
288
289 trace_xfs_attr_node_list(context);
290
291 cursor = context->cursor;
292 cursor->initted = 1;
293
294 /*
295 * Do all sorts of validation on the passed-in cursor structure.
296 * If anything is amiss, ignore the cursor and look up the hashval
297 * starting from the btree root.
298 */
299 bp = NULL;
300 if (cursor->blkno > 0) {
301 error = xfs_da3_node_read(context->tp, dp, cursor->blkno, -1,
302 &bp, XFS_ATTR_FORK);
303 if ((error != 0) && (error != -EFSCORRUPTED))
304 return error;
305 if (bp) {
306 struct xfs_attr_leaf_entry *entries;
307
308 node = bp->b_addr;
309 switch (be16_to_cpu(node->hdr.info.magic)) {
310 case XFS_DA_NODE_MAGIC:
311 case XFS_DA3_NODE_MAGIC:
312 trace_xfs_attr_list_wrong_blk(context);
313 xfs_trans_brelse(context->tp, bp);
314 bp = NULL;
315 break;
316 case XFS_ATTR_LEAF_MAGIC:
317 case XFS_ATTR3_LEAF_MAGIC:
318 leaf = bp->b_addr;
319 xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo,
320 &leafhdr, leaf);
321 entries = xfs_attr3_leaf_entryp(leaf);
322 if (cursor->hashval > be32_to_cpu(
323 entries[leafhdr.count - 1].hashval)) {
324 trace_xfs_attr_list_wrong_blk(context);
325 xfs_trans_brelse(context->tp, bp);
326 bp = NULL;
327 } else if (cursor->hashval <= be32_to_cpu(
328 entries[0].hashval)) {
329 trace_xfs_attr_list_wrong_blk(context);
330 xfs_trans_brelse(context->tp, bp);
331 bp = NULL;
332 }
333 break;
334 default:
335 trace_xfs_attr_list_wrong_blk(context);
336 xfs_trans_brelse(context->tp, bp);
337 bp = NULL;
338 }
339 }
340 }
341
342 /*
343 * We did not find what we expected given the cursor's contents,
344 * so we start from the top and work down based on the hash value.
345 * Note that start of node block is same as start of leaf block.
346 */
347 if (bp == NULL) {
348 error = xfs_attr_node_list_lookup(context, cursor, &bp);
349 if (error || !bp)
350 return error;
351 }
352 ASSERT(bp != NULL);
353
354 /*
355 * Roll upward through the blocks, processing each leaf block in
356 * order. As long as there is space in the result buffer, keep
357 * adding the information.
358 */
359 for (;;) {
360 leaf = bp->b_addr;
361 xfs_attr3_leaf_list_int(bp, context);
362 xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);
363 if (context->seen_enough || leafhdr.forw == 0)
364 break;
365 cursor->blkno = leafhdr.forw;
366 xfs_trans_brelse(context->tp, bp);
367 error = xfs_attr3_leaf_read(context->tp, dp, cursor->blkno, -1, &bp);
368 if (error)
369 return error;
370 }
371 xfs_trans_brelse(context->tp, bp);
372 return 0;
373}
374
375/*
376 * Copy out attribute list entries for attr_list(), for leaf attribute lists.
377 */
378void
379xfs_attr3_leaf_list_int(
380 struct xfs_buf *bp,
381 struct xfs_attr_list_context *context)
382{
383 struct attrlist_cursor_kern *cursor;
384 struct xfs_attr_leafblock *leaf;
385 struct xfs_attr3_icleaf_hdr ichdr;
386 struct xfs_attr_leaf_entry *entries;
387 struct xfs_attr_leaf_entry *entry;
388 int i;
389 struct xfs_mount *mp = context->dp->i_mount;
390
391 trace_xfs_attr_list_leaf(context);
392
393 leaf = bp->b_addr;
394 xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
395 entries = xfs_attr3_leaf_entryp(leaf);
396
397 cursor = context->cursor;
398 cursor->initted = 1;
399
400 /*
401 * Re-find our place in the leaf block if this is a new syscall.
402 */
403 if (context->resynch) {
404 entry = &entries[0];
405 for (i = 0; i < ichdr.count; entry++, i++) {
406 if (be32_to_cpu(entry->hashval) == cursor->hashval) {
407 if (cursor->offset == context->dupcnt) {
408 context->dupcnt = 0;
409 break;
410 }
411 context->dupcnt++;
412 } else if (be32_to_cpu(entry->hashval) >
413 cursor->hashval) {
414 context->dupcnt = 0;
415 break;
416 }
417 }
418 if (i == ichdr.count) {
419 trace_xfs_attr_list_notfound(context);
420 return;
421 }
422 } else {
423 entry = &entries[0];
424 i = 0;
425 }
426 context->resynch = 0;
427
428 /*
429 * We have found our place, start copying out the new attributes.
430 */
431 for (; i < ichdr.count; entry++, i++) {
432 char *name;
433 int namelen, valuelen;
434
435 if (be32_to_cpu(entry->hashval) != cursor->hashval) {
436 cursor->hashval = be32_to_cpu(entry->hashval);
437 cursor->offset = 0;
438 }
439
440 if ((entry->flags & XFS_ATTR_INCOMPLETE) &&
441 !(context->flags & ATTR_INCOMPLETE))
442 continue; /* skip incomplete entries */
443
444 if (entry->flags & XFS_ATTR_LOCAL) {
445 xfs_attr_leaf_name_local_t *name_loc;
446
447 name_loc = xfs_attr3_leaf_name_local(leaf, i);
448 name = name_loc->nameval;
449 namelen = name_loc->namelen;
450 valuelen = be16_to_cpu(name_loc->valuelen);
451 } else {
452 xfs_attr_leaf_name_remote_t *name_rmt;
453
454 name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
455 name = name_rmt->name;
456 namelen = name_rmt->namelen;
457 valuelen = be32_to_cpu(name_rmt->valuelen);
458 }
459
460 context->put_listent(context, entry->flags,
461 name, namelen, valuelen);
462 if (context->seen_enough)
463 break;
464 cursor->offset++;
465 }
466 trace_xfs_attr_list_leaf_end(context);
467 return;
468}
469
470/*
471 * Copy out attribute entries for attr_list(), for leaf attribute lists.
472 */
473STATIC int
474xfs_attr_leaf_list(xfs_attr_list_context_t *context)
475{
476 int error;
477 struct xfs_buf *bp;
478
479 trace_xfs_attr_leaf_list(context);
480
481 context->cursor->blkno = 0;
482 error = xfs_attr3_leaf_read(context->tp, context->dp, 0, -1, &bp);
483 if (error)
484 return error;
485
486 xfs_attr3_leaf_list_int(bp, context);
487 xfs_trans_brelse(context->tp, bp);
488 return 0;
489}
490
491int
492xfs_attr_list_int_ilocked(
493 struct xfs_attr_list_context *context)
494{
495 struct xfs_inode *dp = context->dp;
496
497 ASSERT(xfs_isilocked(dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
498
499 /*
500 * Decide on what work routines to call based on the inode size.
501 */
502 if (!xfs_inode_hasattr(dp))
503 return 0;
504 else if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL)
505 return xfs_attr_shortform_list(context);
506 else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK))
507 return xfs_attr_leaf_list(context);
508 return xfs_attr_node_list(context);
509}
510
511int
512xfs_attr_list_int(
513 xfs_attr_list_context_t *context)
514{
515 int error;
516 xfs_inode_t *dp = context->dp;
517 uint lock_mode;
518
519 XFS_STATS_INC(dp->i_mount, xs_attr_list);
520
521 if (XFS_FORCED_SHUTDOWN(dp->i_mount))
522 return -EIO;
523
524 lock_mode = xfs_ilock_attr_map_shared(dp);
525 error = xfs_attr_list_int_ilocked(context);
526 xfs_iunlock(dp, lock_mode);
527 return error;
528}
529
530#define ATTR_ENTBASESIZE /* minimum bytes used by an attr */ \
531 (((struct attrlist_ent *) 0)->a_name - (char *) 0)
532#define ATTR_ENTSIZE(namelen) /* actual bytes used by an attr */ \
533 ((ATTR_ENTBASESIZE + (namelen) + 1 + sizeof(uint32_t)-1) \
534 & ~(sizeof(uint32_t)-1))
535
536/*
537 * Format an attribute and copy it out to the user's buffer.
538 * Take care to check values and protect against them changing later,
539 * we may be reading them directly out of a user buffer.
540 */
541STATIC void
542xfs_attr_put_listent(
543 xfs_attr_list_context_t *context,
544 int flags,
545 unsigned char *name,
546 int namelen,
547 int valuelen)
548{
549 struct attrlist *alist = (struct attrlist *)context->alist;
550 attrlist_ent_t *aep;
551 int arraytop;
552
553 ASSERT(!context->seen_enough);
554 ASSERT(!(context->flags & ATTR_KERNOVAL));
555 ASSERT(context->count >= 0);
556 ASSERT(context->count < (ATTR_MAX_VALUELEN/8));
557 ASSERT(context->firstu >= sizeof(*alist));
558 ASSERT(context->firstu <= context->bufsize);
559
560 /*
561 * Only list entries in the right namespace.
562 */
563 if (((context->flags & ATTR_SECURE) == 0) !=
564 ((flags & XFS_ATTR_SECURE) == 0))
565 return;
566 if (((context->flags & ATTR_ROOT) == 0) !=
567 ((flags & XFS_ATTR_ROOT) == 0))
568 return;
569
570 arraytop = sizeof(*alist) +
571 context->count * sizeof(alist->al_offset[0]);
572 context->firstu -= ATTR_ENTSIZE(namelen);
573 if (context->firstu < arraytop) {
574 trace_xfs_attr_list_full(context);
575 alist->al_more = 1;
576 context->seen_enough = 1;
577 return;
578 }
579
580 aep = (attrlist_ent_t *)&context->alist[context->firstu];
581 aep->a_valuelen = valuelen;
582 memcpy(aep->a_name, name, namelen);
583 aep->a_name[namelen] = 0;
584 alist->al_offset[context->count++] = context->firstu;
585 alist->al_count = context->count;
586 trace_xfs_attr_list_add(context);
587 return;
588}
589
590/*
591 * Generate a list of extended attribute names and optionally
592 * also value lengths. Positive return value follows the XFS
593 * convention of being an error, zero or negative return code
594 * is the length of the buffer returned (negated), indicating
595 * success.
596 */
597int
598xfs_attr_list(
599 xfs_inode_t *dp,
600 char *buffer,
601 int bufsize,
602 int flags,
603 attrlist_cursor_kern_t *cursor)
604{
605 xfs_attr_list_context_t context;
606 struct attrlist *alist;
607 int error;
608
609 /*
610 * Validate the cursor.
611 */
612 if (cursor->pad1 || cursor->pad2)
613 return -EINVAL;
614 if ((cursor->initted == 0) &&
615 (cursor->hashval || cursor->blkno || cursor->offset))
616 return -EINVAL;
617
618 /* Only internal consumers can retrieve incomplete attrs. */
619 if (flags & ATTR_INCOMPLETE)
620 return -EINVAL;
621
622 /*
623 * Check for a properly aligned buffer.
624 */
625 if (((long)buffer) & (sizeof(int)-1))
626 return -EFAULT;
627 if (flags & ATTR_KERNOVAL)
628 bufsize = 0;
629
630 /*
631 * Initialize the output buffer.
632 */
633 memset(&context, 0, sizeof(context));
634 context.dp = dp;
635 context.cursor = cursor;
636 context.resynch = 1;
637 context.flags = flags;
638 context.alist = buffer;
639 context.bufsize = (bufsize & ~(sizeof(int)-1)); /* align */
640 context.firstu = context.bufsize;
641 context.put_listent = xfs_attr_put_listent;
642
643 alist = (struct attrlist *)context.alist;
644 alist->al_count = 0;
645 alist->al_more = 0;
646 alist->al_offset[0] = context.bufsize;
647
648 error = xfs_attr_list_int(&context);
649 ASSERT(error <= 0);
650 return error;
651}