1/*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * Copyright (c) 2013 Red Hat, Inc.
4 * All Rights Reserved.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it would 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 the Free Software Foundation,
17 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
18 */
19#include "xfs.h"
20#include "xfs_fs.h"
21#include "xfs_format.h"
22#include "xfs_log_format.h"
23#include "xfs_trans_resv.h"
24#include "xfs_bit.h"
25#include "xfs_mount.h"
26#include "xfs_da_format.h"
27#include "xfs_da_btree.h"
28#include "xfs_inode.h"
29#include "xfs_trans.h"
30#include "xfs_inode_item.h"
31#include "xfs_bmap.h"
32#include "xfs_attr.h"
33#include "xfs_attr_sf.h"
34#include "xfs_attr_remote.h"
35#include "xfs_attr_leaf.h"
36#include "xfs_error.h"
37#include "xfs_trace.h"
38#include "xfs_buf_item.h"
39#include "xfs_cksum.h"
40#include "xfs_dir2.h"
41
42STATIC int
43xfs_attr_shortform_compare(const void *a, const void *b)
44{
45	xfs_attr_sf_sort_t *sa, *sb;
46
47	sa = (xfs_attr_sf_sort_t *)a;
48	sb = (xfs_attr_sf_sort_t *)b;
49	if (sa->hash < sb->hash) {
50		return -1;
51	} else if (sa->hash > sb->hash) {
52		return 1;
53	} else {
54		return sa->entno - sb->entno;
55	}
56}
57
58#define XFS_ISRESET_CURSOR(cursor) \
59	(!((cursor)->initted) && !((cursor)->hashval) && \
60	 !((cursor)->blkno) && !((cursor)->offset))
61/*
62 * Copy out entries of shortform attribute lists for attr_list().
63 * Shortform attribute lists are not stored in hashval sorted order.
64 * If the output buffer is not large enough to hold them all, then we
65 * we have to calculate each entries' hashvalue and sort them before
66 * we can begin returning them to the user.
67 */
68int
69xfs_attr_shortform_list(xfs_attr_list_context_t *context)
70{
71	attrlist_cursor_kern_t *cursor;
72	xfs_attr_sf_sort_t *sbuf, *sbp;
73	xfs_attr_shortform_t *sf;
74	xfs_attr_sf_entry_t *sfe;
75	xfs_inode_t *dp;
76	int sbsize, nsbuf, count, i;
77	int error;
78
79	ASSERT(context != NULL);
80	dp = context->dp;
81	ASSERT(dp != NULL);
82	ASSERT(dp->i_afp != NULL);
83	sf = (xfs_attr_shortform_t *)dp->i_afp->if_u1.if_data;
84	ASSERT(sf != NULL);
85	if (!sf->hdr.count)
86		return 0;
87	cursor = context->cursor;
88	ASSERT(cursor != NULL);
89
90	trace_xfs_attr_list_sf(context);
91
92	/*
93	 * If the buffer is large enough and the cursor is at the start,
94	 * do not bother with sorting since we will return everything in
95	 * one buffer and another call using the cursor won't need to be
96	 * made.
97	 * Note the generous fudge factor of 16 overhead bytes per entry.
98	 * If bufsize is zero then put_listent must be a search function
99	 * and can just scan through what we have.
100	 */
101	if (context->bufsize == 0 ||
102	    (XFS_ISRESET_CURSOR(cursor) &&
103             (dp->i_afp->if_bytes + sf->hdr.count * 16) < context->bufsize)) {
104		for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
105			error = context->put_listent(context,
106					   sfe->flags,
107					   sfe->nameval,
108					   (int)sfe->namelen,
109					   (int)sfe->valuelen,
110					   &sfe->nameval[sfe->namelen]);
111
112			/*
113			 * Either search callback finished early or
114			 * didn't fit it all in the buffer after all.
115			 */
116			if (context->seen_enough)
117				break;
118
119			if (error)
120				return error;
121			sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
122		}
123		trace_xfs_attr_list_sf_all(context);
124		return 0;
125	}
126
127	/* do no more for a search callback */
128	if (context->bufsize == 0)
129		return 0;
130
131	/*
132	 * It didn't all fit, so we have to sort everything on hashval.
133	 */
134	sbsize = sf->hdr.count * sizeof(*sbuf);
135	sbp = sbuf = kmem_alloc(sbsize, KM_SLEEP | KM_NOFS);
136
137	/*
138	 * Scan the attribute list for the rest of the entries, storing
139	 * the relevant info from only those that match into a buffer.
140	 */
141	nsbuf = 0;
142	for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
143		if (unlikely(
144		    ((char *)sfe < (char *)sf) ||
145		    ((char *)sfe >= ((char *)sf + dp->i_afp->if_bytes)))) {
146			XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
147					     XFS_ERRLEVEL_LOW,
148					     context->dp->i_mount, sfe);
149			kmem_free(sbuf);
150			return -EFSCORRUPTED;
151		}
152
153		sbp->entno = i;
154		sbp->hash = xfs_da_hashname(sfe->nameval, sfe->namelen);
155		sbp->name = sfe->nameval;
156		sbp->namelen = sfe->namelen;
157		/* These are bytes, and both on-disk, don't endian-flip */
158		sbp->valuelen = sfe->valuelen;
159		sbp->flags = sfe->flags;
160		sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
161		sbp++;
162		nsbuf++;
163	}
164
165	/*
166	 * Sort the entries on hash then entno.
167	 */
168	xfs_sort(sbuf, nsbuf, sizeof(*sbuf), xfs_attr_shortform_compare);
169
170	/*
171	 * Re-find our place IN THE SORTED LIST.
172	 */
173	count = 0;
174	cursor->initted = 1;
175	cursor->blkno = 0;
176	for (sbp = sbuf, i = 0; i < nsbuf; i++, sbp++) {
177		if (sbp->hash == cursor->hashval) {
178			if (cursor->offset == count) {
179				break;
180			}
181			count++;
182		} else if (sbp->hash > cursor->hashval) {
183			break;
184		}
185	}
186	if (i == nsbuf) {
187		kmem_free(sbuf);
188		return 0;
189	}
190
191	/*
192	 * Loop putting entries into the user buffer.
193	 */
194	for ( ; i < nsbuf; i++, sbp++) {
195		if (cursor->hashval != sbp->hash) {
196			cursor->hashval = sbp->hash;
197			cursor->offset = 0;
198		}
199		error = context->put_listent(context,
200					sbp->flags,
201					sbp->name,
202					sbp->namelen,
203					sbp->valuelen,
204					&sbp->name[sbp->namelen]);
205		if (error) {
206			kmem_free(sbuf);
207			return error;
208		}
209		if (context->seen_enough)
210			break;
211		cursor->offset++;
212	}
213
214	kmem_free(sbuf);
215	return 0;
216}
217
218STATIC int
219xfs_attr_node_list(xfs_attr_list_context_t *context)
220{
221	attrlist_cursor_kern_t *cursor;
222	xfs_attr_leafblock_t *leaf;
223	xfs_da_intnode_t *node;
224	struct xfs_attr3_icleaf_hdr leafhdr;
225	struct xfs_da3_icnode_hdr nodehdr;
226	struct xfs_da_node_entry *btree;
227	int error, i;
228	struct xfs_buf *bp;
229	struct xfs_inode	*dp = context->dp;
230	struct xfs_mount	*mp = dp->i_mount;
231
232	trace_xfs_attr_node_list(context);
233
234	cursor = context->cursor;
235	cursor->initted = 1;
236
237	/*
238	 * Do all sorts of validation on the passed-in cursor structure.
239	 * If anything is amiss, ignore the cursor and look up the hashval
240	 * starting from the btree root.
241	 */
242	bp = NULL;
243	if (cursor->blkno > 0) {
244		error = xfs_da3_node_read(NULL, dp, cursor->blkno, -1,
245					      &bp, XFS_ATTR_FORK);
246		if ((error != 0) && (error != -EFSCORRUPTED))
247			return error;
248		if (bp) {
249			struct xfs_attr_leaf_entry *entries;
250
251			node = bp->b_addr;
252			switch (be16_to_cpu(node->hdr.info.magic)) {
253			case XFS_DA_NODE_MAGIC:
254			case XFS_DA3_NODE_MAGIC:
255				trace_xfs_attr_list_wrong_blk(context);
256				xfs_trans_brelse(NULL, bp);
257				bp = NULL;
258				break;
259			case XFS_ATTR_LEAF_MAGIC:
260			case XFS_ATTR3_LEAF_MAGIC:
261				leaf = bp->b_addr;
262				xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo,
263							     &leafhdr, leaf);
264				entries = xfs_attr3_leaf_entryp(leaf);
265				if (cursor->hashval > be32_to_cpu(
266						entries[leafhdr.count - 1].hashval)) {
267					trace_xfs_attr_list_wrong_blk(context);
268					xfs_trans_brelse(NULL, bp);
269					bp = NULL;
270				} else if (cursor->hashval <= be32_to_cpu(
271						entries[0].hashval)) {
272					trace_xfs_attr_list_wrong_blk(context);
273					xfs_trans_brelse(NULL, bp);
274					bp = NULL;
275				}
276				break;
277			default:
278				trace_xfs_attr_list_wrong_blk(context);
279				xfs_trans_brelse(NULL, bp);
280				bp = NULL;
281			}
282		}
283	}
284
285	/*
286	 * We did not find what we expected given the cursor's contents,
287	 * so we start from the top and work down based on the hash value.
288	 * Note that start of node block is same as start of leaf block.
289	 */
290	if (bp == NULL) {
291		cursor->blkno = 0;
292		for (;;) {
293			__uint16_t magic;
294
295			error = xfs_da3_node_read(NULL, dp,
296						      cursor->blkno, -1, &bp,
297						      XFS_ATTR_FORK);
298			if (error)
299				return error;
300			node = bp->b_addr;
301			magic = be16_to_cpu(node->hdr.info.magic);
302			if (magic == XFS_ATTR_LEAF_MAGIC ||
303			    magic == XFS_ATTR3_LEAF_MAGIC)
304				break;
305			if (magic != XFS_DA_NODE_MAGIC &&
306			    magic != XFS_DA3_NODE_MAGIC) {
307				XFS_CORRUPTION_ERROR("xfs_attr_node_list(3)",
308						     XFS_ERRLEVEL_LOW,
309						     context->dp->i_mount,
310						     node);
311				xfs_trans_brelse(NULL, bp);
312				return -EFSCORRUPTED;
313			}
314
315			dp->d_ops->node_hdr_from_disk(&nodehdr, node);
316			btree = dp->d_ops->node_tree_p(node);
317			for (i = 0; i < nodehdr.count; btree++, i++) {
318				if (cursor->hashval
319						<= be32_to_cpu(btree->hashval)) {
320					cursor->blkno = be32_to_cpu(btree->before);
321					trace_xfs_attr_list_node_descend(context,
322									 btree);
323					break;
324				}
325			}
326			if (i == nodehdr.count) {
327				xfs_trans_brelse(NULL, bp);
328				return 0;
329			}
330			xfs_trans_brelse(NULL, bp);
331		}
332	}
333	ASSERT(bp != NULL);
334
335	/*
336	 * Roll upward through the blocks, processing each leaf block in
337	 * order.  As long as there is space in the result buffer, keep
338	 * adding the information.
339	 */
340	for (;;) {
341		leaf = bp->b_addr;
342		error = xfs_attr3_leaf_list_int(bp, context);
343		if (error) {
344			xfs_trans_brelse(NULL, bp);
345			return error;
346		}
347		xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);
348		if (context->seen_enough || leafhdr.forw == 0)
349			break;
350		cursor->blkno = leafhdr.forw;
351		xfs_trans_brelse(NULL, bp);
352		error = xfs_attr3_leaf_read(NULL, dp, cursor->blkno, -1, &bp);
353		if (error)
354			return error;
355	}
356	xfs_trans_brelse(NULL, bp);
357	return 0;
358}
359
360/*
361 * Copy out attribute list entries for attr_list(), for leaf attribute lists.
362 */
363int
364xfs_attr3_leaf_list_int(
365	struct xfs_buf			*bp,
366	struct xfs_attr_list_context	*context)
367{
368	struct attrlist_cursor_kern	*cursor;
369	struct xfs_attr_leafblock	*leaf;
370	struct xfs_attr3_icleaf_hdr	ichdr;
371	struct xfs_attr_leaf_entry	*entries;
372	struct xfs_attr_leaf_entry	*entry;
373	int				retval;
374	int				i;
375	struct xfs_mount		*mp = context->dp->i_mount;
376
377	trace_xfs_attr_list_leaf(context);
378
379	leaf = bp->b_addr;
380	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
381	entries = xfs_attr3_leaf_entryp(leaf);
382
383	cursor = context->cursor;
384	cursor->initted = 1;
385
386	/*
387	 * Re-find our place in the leaf block if this is a new syscall.
388	 */
389	if (context->resynch) {
390		entry = &entries[0];
391		for (i = 0; i < ichdr.count; entry++, i++) {
392			if (be32_to_cpu(entry->hashval) == cursor->hashval) {
393				if (cursor->offset == context->dupcnt) {
394					context->dupcnt = 0;
395					break;
396				}
397				context->dupcnt++;
398			} else if (be32_to_cpu(entry->hashval) >
399					cursor->hashval) {
400				context->dupcnt = 0;
401				break;
402			}
403		}
404		if (i == ichdr.count) {
405			trace_xfs_attr_list_notfound(context);
406			return 0;
407		}
408	} else {
409		entry = &entries[0];
410		i = 0;
411	}
412	context->resynch = 0;
413
414	/*
415	 * We have found our place, start copying out the new attributes.
416	 */
417	retval = 0;
418	for (; i < ichdr.count; entry++, i++) {
419		if (be32_to_cpu(entry->hashval) != cursor->hashval) {
420			cursor->hashval = be32_to_cpu(entry->hashval);
421			cursor->offset = 0;
422		}
423
424		if (entry->flags & XFS_ATTR_INCOMPLETE)
425			continue;		/* skip incomplete entries */
426
427		if (entry->flags & XFS_ATTR_LOCAL) {
428			xfs_attr_leaf_name_local_t *name_loc =
429				xfs_attr3_leaf_name_local(leaf, i);
430
431			retval = context->put_listent(context,
432						entry->flags,
433						name_loc->nameval,
434						(int)name_loc->namelen,
435						be16_to_cpu(name_loc->valuelen),
436						&name_loc->nameval[name_loc->namelen]);
437			if (retval)
438				return retval;
439		} else {
440			xfs_attr_leaf_name_remote_t *name_rmt =
441				xfs_attr3_leaf_name_remote(leaf, i);
442
443			int valuelen = be32_to_cpu(name_rmt->valuelen);
444
445			if (context->put_value) {
446				xfs_da_args_t args;
447
448				memset((char *)&args, 0, sizeof(args));
449				args.geo = context->dp->i_mount->m_attr_geo;
450				args.dp = context->dp;
451				args.whichfork = XFS_ATTR_FORK;
452				args.valuelen = valuelen;
453				args.rmtvaluelen = valuelen;
454				args.value = kmem_alloc(valuelen, KM_SLEEP | KM_NOFS);
455				args.rmtblkno = be32_to_cpu(name_rmt->valueblk);
456				args.rmtblkcnt = xfs_attr3_rmt_blocks(
457							args.dp->i_mount, valuelen);
458				retval = xfs_attr_rmtval_get(&args);
459				if (!retval)
460					retval = context->put_listent(context,
461							entry->flags,
462							name_rmt->name,
463							(int)name_rmt->namelen,
464							valuelen,
465							args.value);
466				kmem_free(args.value);
467			} else {
468				retval = context->put_listent(context,
469						entry->flags,
470						name_rmt->name,
471						(int)name_rmt->namelen,
472						valuelen,
473						NULL);
474			}
475			if (retval)
476				return retval;
477		}
478		if (context->seen_enough)
479			break;
480		cursor->offset++;
481	}
482	trace_xfs_attr_list_leaf_end(context);
483	return retval;
484}
485
486/*
487 * Copy out attribute entries for attr_list(), for leaf attribute lists.
488 */
489STATIC int
490xfs_attr_leaf_list(xfs_attr_list_context_t *context)
491{
492	int error;
493	struct xfs_buf *bp;
494
495	trace_xfs_attr_leaf_list(context);
496
497	context->cursor->blkno = 0;
498	error = xfs_attr3_leaf_read(NULL, context->dp, 0, -1, &bp);
499	if (error)
500		return error;
501
502	error = xfs_attr3_leaf_list_int(bp, context);
503	xfs_trans_brelse(NULL, bp);
504	return error;
505}
506
507int
508xfs_attr_list_int(
509	xfs_attr_list_context_t *context)
510{
511	int error;
512	xfs_inode_t *dp = context->dp;
513	uint		lock_mode;
514
515	XFS_STATS_INC(dp->i_mount, xs_attr_list);
516
517	if (XFS_FORCED_SHUTDOWN(dp->i_mount))
518		return -EIO;
519
520	/*
521	 * Decide on what work routines to call based on the inode size.
522	 */
523	lock_mode = xfs_ilock_attr_map_shared(dp);
524	if (!xfs_inode_hasattr(dp)) {
525		error = 0;
526	} else if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
527		error = xfs_attr_shortform_list(context);
528	} else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
529		error = xfs_attr_leaf_list(context);
530	} else {
531		error = xfs_attr_node_list(context);
532	}
533	xfs_iunlock(dp, lock_mode);
534	return error;
535}
536
537#define	ATTR_ENTBASESIZE		/* minimum bytes used by an attr */ \
538	(((struct attrlist_ent *) 0)->a_name - (char *) 0)
539#define	ATTR_ENTSIZE(namelen)		/* actual bytes used by an attr */ \
540	((ATTR_ENTBASESIZE + (namelen) + 1 + sizeof(u_int32_t)-1) \
541	 & ~(sizeof(u_int32_t)-1))
542
543/*
544 * Format an attribute and copy it out to the user's buffer.
545 * Take care to check values and protect against them changing later,
546 * we may be reading them directly out of a user buffer.
547 */
548STATIC int
549xfs_attr_put_listent(
550	xfs_attr_list_context_t *context,
551	int		flags,
552	unsigned char	*name,
553	int		namelen,
554	int		valuelen,
555	unsigned char	*value)
556{
557	struct attrlist *alist = (struct attrlist *)context->alist;
558	attrlist_ent_t *aep;
559	int arraytop;
560
561	ASSERT(!(context->flags & ATTR_KERNOVAL));
562	ASSERT(context->count >= 0);
563	ASSERT(context->count < (ATTR_MAX_VALUELEN/8));
564	ASSERT(context->firstu >= sizeof(*alist));
565	ASSERT(context->firstu <= context->bufsize);
566
567	/*
568	 * Only list entries in the right namespace.
569	 */
570	if (((context->flags & ATTR_SECURE) == 0) !=
571	    ((flags & XFS_ATTR_SECURE) == 0))
572		return 0;
573	if (((context->flags & ATTR_ROOT) == 0) !=
574	    ((flags & XFS_ATTR_ROOT) == 0))
575		return 0;
576
577	arraytop = sizeof(*alist) +
578			context->count * sizeof(alist->al_offset[0]);
579	context->firstu -= ATTR_ENTSIZE(namelen);
580	if (context->firstu < arraytop) {
581		trace_xfs_attr_list_full(context);
582		alist->al_more = 1;
583		context->seen_enough = 1;
584		return 1;
585	}
586
587	aep = (attrlist_ent_t *)&context->alist[context->firstu];
588	aep->a_valuelen = valuelen;
589	memcpy(aep->a_name, name, namelen);
590	aep->a_name[namelen] = 0;
591	alist->al_offset[context->count++] = context->firstu;
592	alist->al_count = context->count;
593	trace_xfs_attr_list_add(context);
594	return 0;
595}
596
597/*
598 * Generate a list of extended attribute names and optionally
599 * also value lengths.  Positive return value follows the XFS
600 * convention of being an error, zero or negative return code
601 * is the length of the buffer returned (negated), indicating
602 * success.
603 */
604int
605xfs_attr_list(
606	xfs_inode_t	*dp,
607	char		*buffer,
608	int		bufsize,
609	int		flags,
610	attrlist_cursor_kern_t *cursor)
611{
612	xfs_attr_list_context_t context;
613	struct attrlist *alist;
614	int error;
615
616	/*
617	 * Validate the cursor.
618	 */
619	if (cursor->pad1 || cursor->pad2)
620		return -EINVAL;
621	if ((cursor->initted == 0) &&
622	    (cursor->hashval || cursor->blkno || cursor->offset))
623		return -EINVAL;
624
625	/*
626	 * Check for a properly aligned buffer.
627	 */
628	if (((long)buffer) & (sizeof(int)-1))
629		return -EFAULT;
630	if (flags & ATTR_KERNOVAL)
631		bufsize = 0;
632
633	/*
634	 * Initialize the output buffer.
635	 */
636	memset(&context, 0, sizeof(context));
637	context.dp = dp;
638	context.cursor = cursor;
639	context.resynch = 1;
640	context.flags = flags;
641	context.alist = buffer;
642	context.bufsize = (bufsize & ~(sizeof(int)-1));  /* align */
643	context.firstu = context.bufsize;
644	context.put_listent = xfs_attr_put_listent;
645
646	alist = (struct attrlist *)context.alist;
647	alist->al_count = 0;
648	alist->al_more = 0;
649	alist->al_offset[0] = context.bufsize;
650
651	error = xfs_attr_list_int(&context);
652	ASSERT(error <= 0);
653	return error;
654}
655