summaryrefslogtreecommitdiffstats
path: root/fs/ntfs/attr.c
blob: 3b8277643ba03f7962c41799aeda9efcb11c3753 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
/*
 *  attr.c
 *
 *  Copyright (C) 1996-1999 Martin von Löwis
 *  Copyright (C) 1996-1997 Régis Duchesne
 *  Copyright (C) 1998 Joseph Malicki
 *  Copyright (C) 1999 Steve Dodd
 */

#include "ntfstypes.h"
#include "struct.h"
#include "attr.h"

#include <linux/errno.h>
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include "macros.h"
#include "support.h"
#include "util.h"
#include "super.h"
#include "inode.h"

/* Look if an attribute already exists in the inode, and if not, create it */
int 
ntfs_new_attr(ntfs_inode *ino,int type,void *name,int namelen,int *pos,
			int *found, int do_search )
{
	int do_insert=0;
	int i;

	for(i=0;i<ino->attr_count;i++)
	{
		int n=min(namelen,ino->attrs[i].namelen);
		int s=ntfs_uni_strncmp(ino->attrs[i].name,name,n);
		if( do_search ) {
			/*
			 * We assume that each attribute can be uniquely 
			 * identified by inode
			 * number, attribute type and attribute name.
			 */
			if(ino->attrs[i].type==type && ino->attrs[i].namelen==namelen && !s){
				*found=1;
				*pos=i;
				return 0;
			}
		}
		/* attributes are ordered by type, then by name */
		if(ino->attrs[i].type>type || (ino->attrs[i].type==type && s==1)){
			do_insert=1;
			break;
		}
	}

	/* re-allocate space */
	if(ino->attr_count % 8 ==0)
	{
		ntfs_attribute* new;
		new = (ntfs_attribute*)ntfs_malloc((ino->attr_count+8)*
			     sizeof(ntfs_attribute));
		if( !new )
			return ENOMEM;
		if( ino->attrs ) {
			ntfs_memcpy( new, ino->attrs, ino->attr_count*sizeof(ntfs_attribute) );
			ntfs_free( ino->attrs );
		}
		ino->attrs = new;
	}
	if(do_insert)
		ntfs_memmove(ino->attrs+i+1,ino->attrs+i,(ino->attr_count-i)*
			    sizeof(ntfs_attribute));

	ino->attr_count++;
	ino->attrs[i].type=type;
	ino->attrs[i].namelen=namelen;
	ino->attrs[i].name=name;
	*pos=i;
	*found=0;
	return 0;
}

int 
ntfs_make_attr_resident(ntfs_inode *ino,ntfs_attribute *attr)
{
	int size=attr->size;
	if(size>0){
		/* FIXME: read data, free clusters */
		return EOPNOTSUPP;
	}
	attr->resident=1;
	return 0;
}

/* Store in the inode readable information about a run */
void
ntfs_insert_run(ntfs_attribute *attr,int cnum,ntfs_cluster_t cluster,int len)
{
	/* (re-)allocate space if necessary */
	if(attr->d.r.len % 8 == 0) {
		ntfs_runlist* new;
		new = ntfs_malloc((attr->d.r.len+8)*sizeof(ntfs_runlist));
		if( !new )
			return;
		if( attr->d.r.runlist ) {
			ntfs_memcpy(new, attr->d.r.runlist, attr->d.r.len
				    *sizeof(ntfs_runlist));
			ntfs_free( attr->d.r.runlist );
		}
		attr->d.r.runlist = new;
	}
	if(attr->d.r.len>cnum)
		ntfs_memmove(attr->d.r.runlist+cnum+1,attr->d.r.runlist+cnum,
			    (attr->d.r.len-cnum)*sizeof(ntfs_runlist));
	attr->d.r.runlist[cnum].cluster=cluster;
	attr->d.r.runlist[cnum].len=len;
	attr->d.r.len++;
}

/* Extends an attribute. Another run will be added if necessary,
 * but we try to extend the last run in the runlist first.
 * FIXME: what if there isn't enough contiguous space, we don't create
 * multiple runs?
 *
 * *len: the desired new length of the attr (_not_ the amount to extend by)
 */
int ntfs_extend_attr(ntfs_inode *ino, ntfs_attribute *attr, int *len,
		int flags)
{
	int error=0;
	ntfs_runlist *rl;
	int rlen;
	ntfs_cluster_t cluster;
	int clen;

	if(attr->compressed)return EOPNOTSUPP;
	if(ino->record_count>1)return EOPNOTSUPP;

	if(attr->resident) {
		error = ntfs_make_attr_nonresident(ino,attr);
		if(error)
			return error;
	}

	if( *len <= attr->allocated )
		return 0;	/* truely stupid things do sometimes happen */

	rl=attr->d.r.runlist;
	rlen=attr->d.r.len-1;

	if(rlen>=0)
		cluster=rl[rlen].cluster+rl[rlen].len;
	else
		/* no preference for allocation space */
		cluster=0;

	/* calculate the extra space we need, and round up to multiple of cluster
	 * size to get number of new clusters needed */

	clen=( (*len - attr->allocated ) + ino->vol->clustersize - 1 ) /
		ino->vol->clustersize;
	if(clen==0)
		return 0;

	/* FIXME: try to allocate smaller pieces */
	error=ntfs_allocate_clusters(ino->vol,&cluster,&clen,
				     flags|ALLOC_REQUIRE_SIZE);
	if(error)return error;
	attr->allocated += clen*ino->vol->clustersize;
	*len = attr->allocated;

	/* contiguous chunk */
	if(rlen>=0 && cluster==rl[rlen].cluster+rl[rlen].len){
		rl[rlen].len += clen;
		return 0;
	}
	ntfs_insert_run(attr,rlen+1,cluster,clen);
	return 0;
}

int
ntfs_make_attr_nonresident(ntfs_inode *ino, ntfs_attribute *attr)
{
	void *data=attr->d.data;
	int len=attr->size;
	int error,alen;
	ntfs_io io;
	attr->d.r.len=0;
	attr->d.r.runlist=0;
	attr->resident=0;
	attr->allocated=attr->initialized=0;
	alen=len;
	error=ntfs_extend_attr(ino,attr,&alen,ALLOC_REQUIRE_SIZE);
	if(error)return error;/* FIXME: On error, restore old values */
	io.fn_put=ntfs_put;
	io.fn_get=ntfs_get;
	io.param=data;
	io.size=len;
	io.do_read=0;
	return ntfs_readwrite_attr(ino,attr,0,&io);
}

int
ntfs_attr_allnonresident(ntfs_inode *ino)
{
	int i, error=0;
        ntfs_volume *vol = ino->vol;

	for (i=0; !error && i<ino->attr_count; i++)
	{
		if (ino->attrs[i].type != vol->at_security_descriptor
		    && ino->attrs[i].type != vol->at_data)
			continue;
		error = ntfs_make_attr_nonresident (ino, ino->attrs+i);
	}
	return error;
}

/* Resize the attribute to a newsize */
int ntfs_resize_attr(ntfs_inode *ino, ntfs_attribute *attr, int newsize)
{
	int error=0;
	int oldsize=attr->size;
	int clustersize=ino->vol->clustersize;
	int i,count,newlen,newcount;
	ntfs_runlist *rl;

	if(newsize==oldsize)
		return 0;
	/* modifying compressed attributes not supported yet */
	if(attr->compressed)
		/* extending is easy: just insert sparse runs */
		return EOPNOTSUPP;
	if(attr->resident){
		void *v;
		if(newsize>ino->vol->mft_recordsize){
			error=ntfs_make_attr_nonresident(ino,attr);
			if(error)return error;
			return ntfs_resize_attr(ino,attr,newsize);
		}
		v=attr->d.data;
		if(newsize){
			attr->d.data=ntfs_malloc(newsize);
			if(!attr->d.data) {
				ntfs_free(v);
				return ENOMEM;
			}
			if(newsize>oldsize)
				ntfs_bzero((char*)attr->d.data+oldsize,
					   newsize-oldsize);
			ntfs_memcpy((char*)attr->d.data,v,min(newsize,oldsize));
		}else
			attr->d.data=0;
		ntfs_free(v);
		attr->size=newsize;
		return 0;
	}
	/* non-resident attribute */
	rl=attr->d.r.runlist;
	if(newsize<oldsize){
		for(i=0,count=0;i<attr->d.r.len;i++){
			if((count+rl[i].len)*clustersize>newsize)
				break;
			count+=(int)rl[i].len;
		}
		newlen=i+1;
		/* free unused clusters in current run, unless sparse */
		newcount=count;
		if(rl[i].cluster!=MAX_CLUSTER_T){
			int rounded=newsize-count*clustersize;
			rounded=(rounded+clustersize-1)/clustersize;
			error=ntfs_deallocate_clusters(ino->vol,rl[i].cluster+rounded,
						       (int)rl[i].len-rounded);
			if(error)
				return error; /* FIXME: incomplete operation */
			rl[i].len=rounded;
			newcount=count+rounded;
		}
		/* free all other runs */
		for(i++;i<attr->d.r.len;i++)
			if(rl[i].cluster!=MAX_CLUSTER_T){
				error=ntfs_deallocate_clusters(ino->vol,rl[i].cluster,(int)rl[i].len);
				if(error)
					return error; /* FIXME: incomplete operation */
			}
		/* FIXME? free space for extra runs in memory */
		attr->d.r.len=newlen;
	}else{
		newlen=newsize;
		error=ntfs_extend_attr(ino,attr,&newlen,ALLOC_REQUIRE_SIZE);
		if(error)return error; /* FIXME: incomplete */
		newcount=newlen/clustersize;
	}
	/* fill in new sizes */
	attr->allocated = newcount*clustersize;
	attr->size = newsize;
	/* attr->initialized does not change. */
	if(!newsize)
		error=ntfs_make_attr_resident(ino,attr);
	return error;
}

int ntfs_create_attr(ntfs_inode *ino, int anum, char *aname, void *data,
	int dsize, ntfs_attribute **rattr)
{
	void *name;
	int namelen;
	int found,i;
	int error;
	ntfs_attribute *attr;
	if(dsize>ino->vol->mft_recordsize)
		/* FIXME: non-resident attributes */
		return EOPNOTSUPP;
	if(aname){
		namelen=strlen(aname);
		name=ntfs_malloc(2*namelen);
		if( !name )
			return ENOMEM;
		ntfs_ascii2uni(name,aname,namelen);
	}else{
		name=0;
		namelen=0;
	}

	error = ntfs_new_attr(ino,anum,name,namelen,&i,&found,1);
	if( error ) {
		ntfs_free( name );
		return error;
	}

	if(found){
		ntfs_free(name);
		return EEXIST;
	}
	*rattr=attr=ino->attrs+i;
	/* allocate a new number.
	   FIXME: Should this happen on inode writeback?
	   FIXME: extensions records not supported */
	error=ntfs_allocate_attr_number(ino,&i);
	if(error)
		return error;
	attr->attrno=i;

	attr->resident=1;
	attr->compressed=attr->cengine=0;
	attr->size=attr->allocated=attr->initialized=dsize;

	/* FIXME: INDEXED information should come from $AttrDef
	   Currently, only file names are indexed */
	if(anum==ino->vol->at_file_name){
		attr->indexed=1;
	}else
		attr->indexed=0;
	attr->d.data=ntfs_malloc(dsize);

	if( !attr->d.data )
		return ENOMEM;

	ntfs_memcpy(attr->d.data,data,dsize);
	return 0;
}

/* Non-resident attributes are stored in runs (intervals of clusters).
 *
 * This function stores in the inode readable information about a non-resident
 * attribute.
 */
static int 
ntfs_process_runs(ntfs_inode *ino,ntfs_attribute* attr,unsigned char *data)
{
	int startvcn,endvcn;
	int vcn,cnum;
	ntfs_cluster_t cluster;
	int len,ctype;
	startvcn = NTFS_GETU64(data+0x10);
	endvcn = NTFS_GETU64(data+0x18);

	/* check whether this chunk really belongs to the end */
	for(cnum=0,vcn=0;cnum<attr->d.r.len;cnum++)
		vcn+=attr->d.r.runlist[cnum].len;
	if(vcn!=startvcn)
	{
		ntfs_error("Problem with runlist in extended record\n");
		return -1;
	}
	if(!endvcn)
	{
		endvcn = NTFS_GETU64(data+0x28)-1; /* allocated length */
		endvcn /= ino->vol->clustersize;
	}
	data=data+NTFS_GETU16(data+0x20);
	cnum=attr->d.r.len;
	cluster=0;
	for(vcn=startvcn; vcn<=endvcn; vcn+=len)
	{
		if(ntfs_decompress_run(&data,&len,&cluster,&ctype))
			return -1;
		if(ctype)
			ntfs_insert_run(attr,cnum,-1,len);
		else
			ntfs_insert_run(attr,cnum,cluster,len);
		cnum++;
	}
	return 0;
}
  
/* Insert the attribute starting at attr in the inode ino */
int ntfs_insert_attribute(ntfs_inode *ino, unsigned char* attrdata)
{
	int i,found;
	int type;
	short int *name;
	int namelen;
	void *data;
	ntfs_attribute *attr;
	int error;

	type = NTFS_GETU32(attrdata);
	namelen = NTFS_GETU8(attrdata+9);
	/* read the attribute's name if it has one */
	if(!namelen)
		name=0;
	else
	{
		/* 1 Unicode character fits in 2 bytes */
		name=ntfs_malloc(2*namelen);
		if( !name )
			return ENOMEM;

		ntfs_memcpy(name,attrdata+NTFS_GETU16(attrdata+10),2*namelen);
	}

	error = ntfs_new_attr(ino,type,name,namelen,&i,&found,1);
	if( error ) {
		if( name ) ntfs_free( name );
		return error;
	}

	/* We can have in one inode two attributes with type 0x00000030 (File Name) 
	   and without name */
	if(found && /*FIXME*/type!=ino->vol->at_file_name)
	{
		ntfs_process_runs(ino,ino->attrs+i,attrdata);
		return 0;
 	} else if( found ) {
 		/*	Don't understand the above, but I know it leaks memory below
 			as it overwrites a found entry without freeing it. So here we
 			call ntfs_new_attr again but this time ask it to always allocate a
 			new	entry */
 		ntfs_new_attr(ino,type,name,namelen,&i,&found,0);
	}
	attr=ino->attrs+i;
	attr->resident=NTFS_GETU8(attrdata+8)==0;
	attr->compressed=NTFS_GETU16(attrdata+0xC);
	attr->attrno=NTFS_GETU16(attrdata+0xE);
  
	if(attr->resident) {
		attr->size=NTFS_GETU16(attrdata+0x10);
		data=attrdata+NTFS_GETU16(attrdata+0x14);
		attr->d.data = (void*)ntfs_malloc(attr->size);
		if( !attr->d.data )
			return ENOMEM;
		ntfs_memcpy(attr->d.data,data,attr->size);
		attr->indexed=NTFS_GETU16(attrdata+0x16);
	}else{
		attr->allocated=NTFS_GETU32(attrdata+0x28);
		attr->size=NTFS_GETU32(attrdata+0x30);
		attr->initialized=NTFS_GETU32(attrdata+0x38);
		attr->cengine=NTFS_GETU16(attrdata+0x22);
		if(attr->compressed)
			attr->compsize=NTFS_GETU32(attrdata+0x40);
		ino->attrs[i].d.r.runlist=0;
		ino->attrs[i].d.r.len=0;
		ntfs_process_runs(ino,attr,attrdata);
	}
	return 0;
}

int
ntfs_read_zero(ntfs_io *dest,int size)
{
	char *sparse=ntfs_calloc(512);
	if(!sparse)
		return ENOMEM;
	while(size){
		int i=min(size,512);
		dest->fn_put(dest,sparse,i);
		size-=i;
	}
	ntfs_free(sparse);
	return 0;
}

/* process compressed attributes */
int ntfs_read_compressed(ntfs_inode *ino, ntfs_attribute *attr, int offset,
	ntfs_io *dest)
{
	int error=0;
	int clustersize,l;
	int s_vcn,rnum,vcn,len,chunk,got,l1,offs1,copied;
	ntfs_cluster_t cluster,cl1;
	char *comp=0,*comp1;
	char *decomp=0;
	ntfs_io io;
	ntfs_runlist *rl;

	l=dest->size;
	clustersize=ino->vol->clustersize;
	/* starting cluster of potential chunk
	   there are three situations:
	   a) in a large uncompressible or sparse chunk, 
	   s_vcn is in the middle of a run
	   b) s_vcn is right on a run border
	   c) when several runs make a chunk, s_vcn is before the chunks
	*/
	s_vcn=offset/clustersize;
	/* round down to multiple of 16 */
	s_vcn &= ~15;
	rl=attr->d.r.runlist;
	for(rnum=vcn=0;rnum<attr->d.r.len && vcn+rl->len<=s_vcn;rnum++,rl++)
		vcn+=rl->len;
	if(rnum==attr->d.r.len){
		/* beyond end of file */
		/* FIXME: check allocated/initialized */
		dest->size=0;
		return 0;
	}
	io.do_read=1;
	io.fn_put=ntfs_put;
	io.fn_get=0;
	cluster=rl->cluster;
	len=rl->len;
	copied=0;
	while(l){
		chunk=0;
		if(cluster==MAX_CLUSTER_T){
			/* sparse cluster */
			int l1;
			if((len-(s_vcn-vcn)) & 15)
				ntfs_error("unexpected sparse chunk size");
			l1=chunk = min((vcn+len)*clustersize-offset,l);
			error = ntfs_read_zero(dest,l1);
			if(error)
				goto out;
		}else if(dest->do_read){
			if(!comp){
				comp=ntfs_malloc(16*clustersize);
				if(!comp){
					error=ENOMEM;
					goto out;
				}
			}
			got=0;
			/* we might need to start in the middle of a run */
			cl1=cluster+s_vcn-vcn;
			comp1=comp;
			do{
				io.param=comp1;
				l1=min(len-max(s_vcn-vcn,0),16-got);
				io.size=l1*clustersize;
				error=ntfs_getput_clusters(ino->vol,cl1,0,&io);
				if(error)goto out;
				if(l1+max(s_vcn-vcn,0)==len){
					rnum++;rl++;
					vcn+=len;
					cluster=cl1=rl->cluster;
					len=rl->len;
				}
				got+=l1;
				comp1+=l1*clustersize;
			}while(cluster!=MAX_CLUSTER_T && got<16); /* until empty run */
			chunk=16*clustersize;
			if(cluster!=MAX_CLUSTER_T || got==16)
				/* uncompressible */
				comp1=comp;
			else{
				if(!decomp){
					decomp=ntfs_malloc(16*clustersize);
					if(!decomp){
						error=ENOMEM;
						goto out;
					}
				}
				/* make sure there are null bytes
				   after the last block */
				*(ntfs_u32*)comp1=0;
				ntfs_decompress(decomp,comp,chunk);
				comp1=decomp;
			}
			offs1=offset-s_vcn*clustersize;
			chunk=min(16*clustersize-offs1,chunk);
			chunk=min(l,chunk);
			dest->fn_put(dest,comp1+offs1,chunk);
		}
		l-=chunk;
		copied+=chunk;
		offset+=chunk;
		s_vcn=offset/clustersize & ~15;
		if(l && offset>=((vcn+len)*clustersize)){
			rnum++;rl++;
			vcn+=len;
			cluster=rl->cluster;
			len=rl->len;
		}
	}
 out:
	if(comp)ntfs_free(comp);
	if(decomp)ntfs_free(decomp);
	dest->size=copied;
	return error;
}

int ntfs_write_compressed(ntfs_inode *ino, ntfs_attribute *attr, int offset,
	ntfs_io *dest)
{
	return EOPNOTSUPP;
}

/*
 * Local variables:
 * c-file-style: "linux"
 * End:
 */