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1/*
2 * linux/fs/isofs/rock.c
3 *
4 * (C) 1992, 1993 Eric Youngdale
5 *
6 * Rock Ridge Extensions to iso9660
7 */
8
9#include <linux/slab.h>
10#include <linux/pagemap.h>
11
12#include "isofs.h"
13#include "rock.h"
14
15/*
16 * These functions are designed to read the system areas of a directory record
17 * and extract relevant information. There are different functions provided
18 * depending upon what information we need at the time. One function fills
19 * out an inode structure, a second one extracts a filename, a third one
20 * returns a symbolic link name, and a fourth one returns the extent number
21 * for the file.
22 */
23
24#define SIG(A,B) ((A) | ((B) << 8)) /* isonum_721() */
25
26struct rock_state {
27 void *buffer;
28 unsigned char *chr;
29 int len;
30 int cont_size;
31 int cont_extent;
32 int cont_offset;
33 struct inode *inode;
34};
35
36/*
37 * This is a way of ensuring that we have something in the system
38 * use fields that is compatible with Rock Ridge. Return zero on success.
39 */
40
41static int check_sp(struct rock_ridge *rr, struct inode *inode)
42{
43 if (rr->u.SP.magic[0] != 0xbe)
44 return -1;
45 if (rr->u.SP.magic[1] != 0xef)
46 return -1;
47 ISOFS_SB(inode->i_sb)->s_rock_offset = rr->u.SP.skip;
48 return 0;
49}
50
51static void setup_rock_ridge(struct iso_directory_record *de,
52 struct inode *inode, struct rock_state *rs)
53{
54 rs->len = sizeof(struct iso_directory_record) + de->name_len[0];
55 if (rs->len & 1)
56 (rs->len)++;
57 rs->chr = (unsigned char *)de + rs->len;
58 rs->len = *((unsigned char *)de) - rs->len;
59 if (rs->len < 0)
60 rs->len = 0;
61
62 if (ISOFS_SB(inode->i_sb)->s_rock_offset != -1) {
63 rs->len -= ISOFS_SB(inode->i_sb)->s_rock_offset;
64 rs->chr += ISOFS_SB(inode->i_sb)->s_rock_offset;
65 if (rs->len < 0)
66 rs->len = 0;
67 }
68}
69
70static void init_rock_state(struct rock_state *rs, struct inode *inode)
71{
72 memset(rs, 0, sizeof(*rs));
73 rs->inode = inode;
74}
75
76/*
77 * Returns 0 if the caller should continue scanning, 1 if the scan must end
78 * and -ve on error.
79 */
80static int rock_continue(struct rock_state *rs)
81{
82 int ret = 1;
83 int blocksize = 1 << rs->inode->i_blkbits;
84 const int min_de_size = offsetof(struct rock_ridge, u);
85
86 kfree(rs->buffer);
87 rs->buffer = NULL;
88
89 if ((unsigned)rs->cont_offset > blocksize - min_de_size ||
90 (unsigned)rs->cont_size > blocksize ||
91 (unsigned)(rs->cont_offset + rs->cont_size) > blocksize) {
92 printk(KERN_NOTICE "rock: corrupted directory entry. "
93 "extent=%d, offset=%d, size=%d\n",
94 rs->cont_extent, rs->cont_offset, rs->cont_size);
95 ret = -EIO;
96 goto out;
97 }
98
99 if (rs->cont_extent) {
100 struct buffer_head *bh;
101
102 rs->buffer = kmalloc(rs->cont_size, GFP_KERNEL);
103 if (!rs->buffer) {
104 ret = -ENOMEM;
105 goto out;
106 }
107 ret = -EIO;
108 bh = sb_bread(rs->inode->i_sb, rs->cont_extent);
109 if (bh) {
110 memcpy(rs->buffer, bh->b_data + rs->cont_offset,
111 rs->cont_size);
112 put_bh(bh);
113 rs->chr = rs->buffer;
114 rs->len = rs->cont_size;
115 rs->cont_extent = 0;
116 rs->cont_size = 0;
117 rs->cont_offset = 0;
118 return 0;
119 }
120 printk("Unable to read rock-ridge attributes\n");
121 }
122out:
123 kfree(rs->buffer);
124 rs->buffer = NULL;
125 return ret;
126}
127
128/*
129 * We think there's a record of type `sig' at rs->chr. Parse the signature
130 * and make sure that there's really room for a record of that type.
131 */
132static int rock_check_overflow(struct rock_state *rs, int sig)
133{
134 int len;
135
136 switch (sig) {
137 case SIG('S', 'P'):
138 len = sizeof(struct SU_SP_s);
139 break;
140 case SIG('C', 'E'):
141 len = sizeof(struct SU_CE_s);
142 break;
143 case SIG('E', 'R'):
144 len = sizeof(struct SU_ER_s);
145 break;
146 case SIG('R', 'R'):
147 len = sizeof(struct RR_RR_s);
148 break;
149 case SIG('P', 'X'):
150 len = sizeof(struct RR_PX_s);
151 break;
152 case SIG('P', 'N'):
153 len = sizeof(struct RR_PN_s);
154 break;
155 case SIG('S', 'L'):
156 len = sizeof(struct RR_SL_s);
157 break;
158 case SIG('N', 'M'):
159 len = sizeof(struct RR_NM_s);
160 break;
161 case SIG('C', 'L'):
162 len = sizeof(struct RR_CL_s);
163 break;
164 case SIG('P', 'L'):
165 len = sizeof(struct RR_PL_s);
166 break;
167 case SIG('T', 'F'):
168 len = sizeof(struct RR_TF_s);
169 break;
170 case SIG('Z', 'F'):
171 len = sizeof(struct RR_ZF_s);
172 break;
173 default:
174 len = 0;
175 break;
176 }
177 len += offsetof(struct rock_ridge, u);
178 if (len > rs->len) {
179 printk(KERN_NOTICE "rock: directory entry would overflow "
180 "storage\n");
181 printk(KERN_NOTICE "rock: sig=0x%02x, size=%d, remaining=%d\n",
182 sig, len, rs->len);
183 return -EIO;
184 }
185 return 0;
186}
187
188/*
189 * return length of name field; 0: not found, -1: to be ignored
190 */
191int get_rock_ridge_filename(struct iso_directory_record *de,
192 char *retname, struct inode *inode)
193{
194 struct rock_state rs;
195 struct rock_ridge *rr;
196 int sig;
197 int retnamlen = 0;
198 int truncate = 0;
199 int ret = 0;
200
201 if (!ISOFS_SB(inode->i_sb)->s_rock)
202 return 0;
203 *retname = 0;
204
205 init_rock_state(&rs, inode);
206 setup_rock_ridge(de, inode, &rs);
207repeat:
208
209 while (rs.len > 2) { /* There may be one byte for padding somewhere */
210 rr = (struct rock_ridge *)rs.chr;
211 /*
212 * Ignore rock ridge info if rr->len is out of range, but
213 * don't return -EIO because that would make the file
214 * invisible.
215 */
216 if (rr->len < 3)
217 goto out; /* Something got screwed up here */
218 sig = isonum_721(rs.chr);
219 if (rock_check_overflow(&rs, sig))
220 goto eio;
221 rs.chr += rr->len;
222 rs.len -= rr->len;
223 /*
224 * As above, just ignore the rock ridge info if rr->len
225 * is bogus.
226 */
227 if (rs.len < 0)
228 goto out; /* Something got screwed up here */
229
230 switch (sig) {
231 case SIG('R', 'R'):
232 if ((rr->u.RR.flags[0] & RR_NM) == 0)
233 goto out;
234 break;
235 case SIG('S', 'P'):
236 if (check_sp(rr, inode))
237 goto out;
238 break;
239 case SIG('C', 'E'):
240 rs.cont_extent = isonum_733(rr->u.CE.extent);
241 rs.cont_offset = isonum_733(rr->u.CE.offset);
242 rs.cont_size = isonum_733(rr->u.CE.size);
243 break;
244 case SIG('N', 'M'):
245 if (truncate)
246 break;
247 if (rr->len < 5)
248 break;
249 /*
250 * If the flags are 2 or 4, this indicates '.' or '..'.
251 * We don't want to do anything with this, because it
252 * screws up the code that calls us. We don't really
253 * care anyways, since we can just use the non-RR
254 * name.
255 */
256 if (rr->u.NM.flags & 6)
257 break;
258
259 if (rr->u.NM.flags & ~1) {
260 printk("Unsupported NM flag settings (%d)\n",
261 rr->u.NM.flags);
262 break;
263 }
264 if ((strlen(retname) + rr->len - 5) >= 254) {
265 truncate = 1;
266 break;
267 }
268 strncat(retname, rr->u.NM.name, rr->len - 5);
269 retnamlen += rr->len - 5;
270 break;
271 case SIG('R', 'E'):
272 kfree(rs.buffer);
273 return -1;
274 default:
275 break;
276 }
277 }
278 ret = rock_continue(&rs);
279 if (ret == 0)
280 goto repeat;
281 if (ret == 1)
282 return retnamlen; /* If 0, this file did not have a NM field */
283out:
284 kfree(rs.buffer);
285 return ret;
286eio:
287 ret = -EIO;
288 goto out;
289}
290
291static int
292parse_rock_ridge_inode_internal(struct iso_directory_record *de,
293 struct inode *inode, int regard_xa)
294{
295 int symlink_len = 0;
296 int cnt, sig;
297 struct inode *reloc;
298 struct rock_ridge *rr;
299 int rootflag;
300 struct rock_state rs;
301 int ret = 0;
302
303 if (!ISOFS_SB(inode->i_sb)->s_rock)
304 return 0;
305
306 init_rock_state(&rs, inode);
307 setup_rock_ridge(de, inode, &rs);
308 if (regard_xa) {
309 rs.chr += 14;
310 rs.len -= 14;
311 if (rs.len < 0)
312 rs.len = 0;
313 }
314
315repeat:
316 while (rs.len > 2) { /* There may be one byte for padding somewhere */
317 rr = (struct rock_ridge *)rs.chr;
318 /*
319 * Ignore rock ridge info if rr->len is out of range, but
320 * don't return -EIO because that would make the file
321 * invisible.
322 */
323 if (rr->len < 3)
324 goto out; /* Something got screwed up here */
325 sig = isonum_721(rs.chr);
326 if (rock_check_overflow(&rs, sig))
327 goto eio;
328 rs.chr += rr->len;
329 rs.len -= rr->len;
330 /*
331 * As above, just ignore the rock ridge info if rr->len
332 * is bogus.
333 */
334 if (rs.len < 0)
335 goto out; /* Something got screwed up here */
336
337 switch (sig) {
338#ifndef CONFIG_ZISOFS /* No flag for SF or ZF */
339 case SIG('R', 'R'):
340 if ((rr->u.RR.flags[0] &
341 (RR_PX | RR_TF | RR_SL | RR_CL)) == 0)
342 goto out;
343 break;
344#endif
345 case SIG('S', 'P'):
346 if (check_sp(rr, inode))
347 goto out;
348 break;
349 case SIG('C', 'E'):
350 rs.cont_extent = isonum_733(rr->u.CE.extent);
351 rs.cont_offset = isonum_733(rr->u.CE.offset);
352 rs.cont_size = isonum_733(rr->u.CE.size);
353 break;
354 case SIG('E', 'R'):
355 ISOFS_SB(inode->i_sb)->s_rock = 1;
356 printk(KERN_DEBUG "ISO 9660 Extensions: ");
357 {
358 int p;
359 for (p = 0; p < rr->u.ER.len_id; p++)
360 printk("%c", rr->u.ER.data[p]);
361 }
362 printk("\n");
363 break;
364 case SIG('P', 'X'):
365 inode->i_mode = isonum_733(rr->u.PX.mode);
366 set_nlink(inode, isonum_733(rr->u.PX.n_links));
367 inode->i_uid = isonum_733(rr->u.PX.uid);
368 inode->i_gid = isonum_733(rr->u.PX.gid);
369 break;
370 case SIG('P', 'N'):
371 {
372 int high, low;
373 high = isonum_733(rr->u.PN.dev_high);
374 low = isonum_733(rr->u.PN.dev_low);
375 /*
376 * The Rock Ridge standard specifies that if
377 * sizeof(dev_t) <= 4, then the high field is
378 * unused, and the device number is completely
379 * stored in the low field. Some writers may
380 * ignore this subtlety,
381 * and as a result we test to see if the entire
382 * device number is
383 * stored in the low field, and use that.
384 */
385 if ((low & ~0xff) && high == 0) {
386 inode->i_rdev =
387 MKDEV(low >> 8, low & 0xff);
388 } else {
389 inode->i_rdev =
390 MKDEV(high, low);
391 }
392 }
393 break;
394 case SIG('T', 'F'):
395 /*
396 * Some RRIP writers incorrectly place ctime in the
397 * TF_CREATE field. Try to handle this correctly for
398 * either case.
399 */
400 /* Rock ridge never appears on a High Sierra disk */
401 cnt = 0;
402 if (rr->u.TF.flags & TF_CREATE) {
403 inode->i_ctime.tv_sec =
404 iso_date(rr->u.TF.times[cnt++].time,
405 0);
406 inode->i_ctime.tv_nsec = 0;
407 }
408 if (rr->u.TF.flags & TF_MODIFY) {
409 inode->i_mtime.tv_sec =
410 iso_date(rr->u.TF.times[cnt++].time,
411 0);
412 inode->i_mtime.tv_nsec = 0;
413 }
414 if (rr->u.TF.flags & TF_ACCESS) {
415 inode->i_atime.tv_sec =
416 iso_date(rr->u.TF.times[cnt++].time,
417 0);
418 inode->i_atime.tv_nsec = 0;
419 }
420 if (rr->u.TF.flags & TF_ATTRIBUTES) {
421 inode->i_ctime.tv_sec =
422 iso_date(rr->u.TF.times[cnt++].time,
423 0);
424 inode->i_ctime.tv_nsec = 0;
425 }
426 break;
427 case SIG('S', 'L'):
428 {
429 int slen;
430 struct SL_component *slp;
431 struct SL_component *oldslp;
432 slen = rr->len - 5;
433 slp = &rr->u.SL.link;
434 inode->i_size = symlink_len;
435 while (slen > 1) {
436 rootflag = 0;
437 switch (slp->flags & ~1) {
438 case 0:
439 inode->i_size +=
440 slp->len;
441 break;
442 case 2:
443 inode->i_size += 1;
444 break;
445 case 4:
446 inode->i_size += 2;
447 break;
448 case 8:
449 rootflag = 1;
450 inode->i_size += 1;
451 break;
452 default:
453 printk("Symlink component flag "
454 "not implemented\n");
455 }
456 slen -= slp->len + 2;
457 oldslp = slp;
458 slp = (struct SL_component *)
459 (((char *)slp) + slp->len + 2);
460
461 if (slen < 2) {
462 if (((rr->u.SL.
463 flags & 1) != 0)
464 &&
465 ((oldslp->
466 flags & 1) == 0))
467 inode->i_size +=
468 1;
469 break;
470 }
471
472 /*
473 * If this component record isn't
474 * continued, then append a '/'.
475 */
476 if (!rootflag
477 && (oldslp->flags & 1) == 0)
478 inode->i_size += 1;
479 }
480 }
481 symlink_len = inode->i_size;
482 break;
483 case SIG('R', 'E'):
484 printk(KERN_WARNING "Attempt to read inode for "
485 "relocated directory\n");
486 goto out;
487 case SIG('C', 'L'):
488 ISOFS_I(inode)->i_first_extent =
489 isonum_733(rr->u.CL.location);
490 reloc =
491 isofs_iget(inode->i_sb,
492 ISOFS_I(inode)->i_first_extent,
493 0);
494 if (IS_ERR(reloc)) {
495 ret = PTR_ERR(reloc);
496 goto out;
497 }
498 inode->i_mode = reloc->i_mode;
499 set_nlink(inode, reloc->i_nlink);
500 inode->i_uid = reloc->i_uid;
501 inode->i_gid = reloc->i_gid;
502 inode->i_rdev = reloc->i_rdev;
503 inode->i_size = reloc->i_size;
504 inode->i_blocks = reloc->i_blocks;
505 inode->i_atime = reloc->i_atime;
506 inode->i_ctime = reloc->i_ctime;
507 inode->i_mtime = reloc->i_mtime;
508 iput(reloc);
509 break;
510#ifdef CONFIG_ZISOFS
511 case SIG('Z', 'F'): {
512 int algo;
513
514 if (ISOFS_SB(inode->i_sb)->s_nocompress)
515 break;
516 algo = isonum_721(rr->u.ZF.algorithm);
517 if (algo == SIG('p', 'z')) {
518 int block_shift =
519 isonum_711(&rr->u.ZF.parms[1]);
520 if (block_shift > 17) {
521 printk(KERN_WARNING "isofs: "
522 "Can't handle ZF block "
523 "size of 2^%d\n",
524 block_shift);
525 } else {
526 /*
527 * Note: we don't change
528 * i_blocks here
529 */
530 ISOFS_I(inode)->i_file_format =
531 isofs_file_compressed;
532 /*
533 * Parameters to compression
534 * algorithm (header size,
535 * block size)
536 */
537 ISOFS_I(inode)->i_format_parm[0] =
538 isonum_711(&rr->u.ZF.parms[0]);
539 ISOFS_I(inode)->i_format_parm[1] =
540 isonum_711(&rr->u.ZF.parms[1]);
541 inode->i_size =
542 isonum_733(rr->u.ZF.
543 real_size);
544 }
545 } else {
546 printk(KERN_WARNING
547 "isofs: Unknown ZF compression "
548 "algorithm: %c%c\n",
549 rr->u.ZF.algorithm[0],
550 rr->u.ZF.algorithm[1]);
551 }
552 break;
553 }
554#endif
555 default:
556 break;
557 }
558 }
559 ret = rock_continue(&rs);
560 if (ret == 0)
561 goto repeat;
562 if (ret == 1)
563 ret = 0;
564out:
565 kfree(rs.buffer);
566 return ret;
567eio:
568 ret = -EIO;
569 goto out;
570}
571
572static char *get_symlink_chunk(char *rpnt, struct rock_ridge *rr, char *plimit)
573{
574 int slen;
575 int rootflag;
576 struct SL_component *oldslp;
577 struct SL_component *slp;
578 slen = rr->len - 5;
579 slp = &rr->u.SL.link;
580 while (slen > 1) {
581 rootflag = 0;
582 switch (slp->flags & ~1) {
583 case 0:
584 if (slp->len > plimit - rpnt)
585 return NULL;
586 memcpy(rpnt, slp->text, slp->len);
587 rpnt += slp->len;
588 break;
589 case 2:
590 if (rpnt >= plimit)
591 return NULL;
592 *rpnt++ = '.';
593 break;
594 case 4:
595 if (2 > plimit - rpnt)
596 return NULL;
597 *rpnt++ = '.';
598 *rpnt++ = '.';
599 break;
600 case 8:
601 if (rpnt >= plimit)
602 return NULL;
603 rootflag = 1;
604 *rpnt++ = '/';
605 break;
606 default:
607 printk("Symlink component flag not implemented (%d)\n",
608 slp->flags);
609 }
610 slen -= slp->len + 2;
611 oldslp = slp;
612 slp = (struct SL_component *)((char *)slp + slp->len + 2);
613
614 if (slen < 2) {
615 /*
616 * If there is another SL record, and this component
617 * record isn't continued, then add a slash.
618 */
619 if ((!rootflag) && (rr->u.SL.flags & 1) &&
620 !(oldslp->flags & 1)) {
621 if (rpnt >= plimit)
622 return NULL;
623 *rpnt++ = '/';
624 }
625 break;
626 }
627
628 /*
629 * If this component record isn't continued, then append a '/'.
630 */
631 if (!rootflag && !(oldslp->flags & 1)) {
632 if (rpnt >= plimit)
633 return NULL;
634 *rpnt++ = '/';
635 }
636 }
637 return rpnt;
638}
639
640int parse_rock_ridge_inode(struct iso_directory_record *de, struct inode *inode)
641{
642 int result = parse_rock_ridge_inode_internal(de, inode, 0);
643
644 /*
645 * if rockridge flag was reset and we didn't look for attributes
646 * behind eventual XA attributes, have a look there
647 */
648 if ((ISOFS_SB(inode->i_sb)->s_rock_offset == -1)
649 && (ISOFS_SB(inode->i_sb)->s_rock == 2)) {
650 result = parse_rock_ridge_inode_internal(de, inode, 14);
651 }
652 return result;
653}
654
655/*
656 * readpage() for symlinks: reads symlink contents into the page and either
657 * makes it uptodate and returns 0 or returns error (-EIO)
658 */
659static int rock_ridge_symlink_readpage(struct file *file, struct page *page)
660{
661 struct inode *inode = page->mapping->host;
662 struct iso_inode_info *ei = ISOFS_I(inode);
663 struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb);
664 char *link = kmap(page);
665 unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
666 struct buffer_head *bh;
667 char *rpnt = link;
668 unsigned char *pnt;
669 struct iso_directory_record *raw_de;
670 unsigned long block, offset;
671 int sig;
672 struct rock_ridge *rr;
673 struct rock_state rs;
674 int ret;
675
676 if (!sbi->s_rock)
677 goto error;
678
679 init_rock_state(&rs, inode);
680 block = ei->i_iget5_block;
681 bh = sb_bread(inode->i_sb, block);
682 if (!bh)
683 goto out_noread;
684
685 offset = ei->i_iget5_offset;
686 pnt = (unsigned char *)bh->b_data + offset;
687
688 raw_de = (struct iso_directory_record *)pnt;
689
690 /*
691 * If we go past the end of the buffer, there is some sort of error.
692 */
693 if (offset + *pnt > bufsize)
694 goto out_bad_span;
695
696 /*
697 * Now test for possible Rock Ridge extensions which will override
698 * some of these numbers in the inode structure.
699 */
700
701 setup_rock_ridge(raw_de, inode, &rs);
702
703repeat:
704 while (rs.len > 2) { /* There may be one byte for padding somewhere */
705 rr = (struct rock_ridge *)rs.chr;
706 if (rr->len < 3)
707 goto out; /* Something got screwed up here */
708 sig = isonum_721(rs.chr);
709 if (rock_check_overflow(&rs, sig))
710 goto out;
711 rs.chr += rr->len;
712 rs.len -= rr->len;
713 if (rs.len < 0)
714 goto out; /* corrupted isofs */
715
716 switch (sig) {
717 case SIG('R', 'R'):
718 if ((rr->u.RR.flags[0] & RR_SL) == 0)
719 goto out;
720 break;
721 case SIG('S', 'P'):
722 if (check_sp(rr, inode))
723 goto out;
724 break;
725 case SIG('S', 'L'):
726 rpnt = get_symlink_chunk(rpnt, rr,
727 link + (PAGE_SIZE - 1));
728 if (rpnt == NULL)
729 goto out;
730 break;
731 case SIG('C', 'E'):
732 /* This tells is if there is a continuation record */
733 rs.cont_extent = isonum_733(rr->u.CE.extent);
734 rs.cont_offset = isonum_733(rr->u.CE.offset);
735 rs.cont_size = isonum_733(rr->u.CE.size);
736 default:
737 break;
738 }
739 }
740 ret = rock_continue(&rs);
741 if (ret == 0)
742 goto repeat;
743 if (ret < 0)
744 goto fail;
745
746 if (rpnt == link)
747 goto fail;
748 brelse(bh);
749 *rpnt = '\0';
750 SetPageUptodate(page);
751 kunmap(page);
752 unlock_page(page);
753 return 0;
754
755 /* error exit from macro */
756out:
757 kfree(rs.buffer);
758 goto fail;
759out_noread:
760 printk("unable to read i-node block");
761 goto fail;
762out_bad_span:
763 printk("symlink spans iso9660 blocks\n");
764fail:
765 brelse(bh);
766error:
767 SetPageError(page);
768 kunmap(page);
769 unlock_page(page);
770 return -EIO;
771}
772
773const struct address_space_operations isofs_symlink_aops = {
774 .readpage = rock_ridge_symlink_readpage
775};
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/isofs/rock.c
4 *
5 * (C) 1992, 1993 Eric Youngdale
6 *
7 * Rock Ridge Extensions to iso9660
8 */
9
10#include <linux/slab.h>
11#include <linux/pagemap.h>
12
13#include "isofs.h"
14#include "rock.h"
15
16/*
17 * These functions are designed to read the system areas of a directory record
18 * and extract relevant information. There are different functions provided
19 * depending upon what information we need at the time. One function fills
20 * out an inode structure, a second one extracts a filename, a third one
21 * returns a symbolic link name, and a fourth one returns the extent number
22 * for the file.
23 */
24
25#define SIG(A,B) ((A) | ((B) << 8)) /* isonum_721() */
26
27struct rock_state {
28 void *buffer;
29 unsigned char *chr;
30 int len;
31 int cont_size;
32 int cont_extent;
33 int cont_offset;
34 int cont_loops;
35 struct inode *inode;
36};
37
38/*
39 * This is a way of ensuring that we have something in the system
40 * use fields that is compatible with Rock Ridge. Return zero on success.
41 */
42
43static int check_sp(struct rock_ridge *rr, struct inode *inode)
44{
45 if (rr->u.SP.magic[0] != 0xbe)
46 return -1;
47 if (rr->u.SP.magic[1] != 0xef)
48 return -1;
49 ISOFS_SB(inode->i_sb)->s_rock_offset = rr->u.SP.skip;
50 return 0;
51}
52
53static void setup_rock_ridge(struct iso_directory_record *de,
54 struct inode *inode, struct rock_state *rs)
55{
56 rs->len = sizeof(struct iso_directory_record) + de->name_len[0];
57 if (rs->len & 1)
58 (rs->len)++;
59 rs->chr = (unsigned char *)de + rs->len;
60 rs->len = *((unsigned char *)de) - rs->len;
61 if (rs->len < 0)
62 rs->len = 0;
63
64 if (ISOFS_SB(inode->i_sb)->s_rock_offset != -1) {
65 rs->len -= ISOFS_SB(inode->i_sb)->s_rock_offset;
66 rs->chr += ISOFS_SB(inode->i_sb)->s_rock_offset;
67 if (rs->len < 0)
68 rs->len = 0;
69 }
70}
71
72static void init_rock_state(struct rock_state *rs, struct inode *inode)
73{
74 memset(rs, 0, sizeof(*rs));
75 rs->inode = inode;
76}
77
78/* Maximum number of Rock Ridge continuation entries */
79#define RR_MAX_CE_ENTRIES 32
80
81/*
82 * Returns 0 if the caller should continue scanning, 1 if the scan must end
83 * and -ve on error.
84 */
85static int rock_continue(struct rock_state *rs)
86{
87 int ret = 1;
88 int blocksize = 1 << rs->inode->i_blkbits;
89 const int min_de_size = offsetof(struct rock_ridge, u);
90
91 kfree(rs->buffer);
92 rs->buffer = NULL;
93
94 if ((unsigned)rs->cont_offset > blocksize - min_de_size ||
95 (unsigned)rs->cont_size > blocksize ||
96 (unsigned)(rs->cont_offset + rs->cont_size) > blocksize) {
97 printk(KERN_NOTICE "rock: corrupted directory entry. "
98 "extent=%d, offset=%d, size=%d\n",
99 rs->cont_extent, rs->cont_offset, rs->cont_size);
100 ret = -EIO;
101 goto out;
102 }
103
104 if (rs->cont_extent) {
105 struct buffer_head *bh;
106
107 rs->buffer = kmalloc(rs->cont_size, GFP_KERNEL);
108 if (!rs->buffer) {
109 ret = -ENOMEM;
110 goto out;
111 }
112 ret = -EIO;
113 if (++rs->cont_loops >= RR_MAX_CE_ENTRIES)
114 goto out;
115 bh = sb_bread(rs->inode->i_sb, rs->cont_extent);
116 if (bh) {
117 memcpy(rs->buffer, bh->b_data + rs->cont_offset,
118 rs->cont_size);
119 put_bh(bh);
120 rs->chr = rs->buffer;
121 rs->len = rs->cont_size;
122 rs->cont_extent = 0;
123 rs->cont_size = 0;
124 rs->cont_offset = 0;
125 return 0;
126 }
127 printk("Unable to read rock-ridge attributes\n");
128 }
129out:
130 kfree(rs->buffer);
131 rs->buffer = NULL;
132 return ret;
133}
134
135/*
136 * We think there's a record of type `sig' at rs->chr. Parse the signature
137 * and make sure that there's really room for a record of that type.
138 */
139static int rock_check_overflow(struct rock_state *rs, int sig)
140{
141 int len;
142
143 switch (sig) {
144 case SIG('S', 'P'):
145 len = sizeof(struct SU_SP_s);
146 break;
147 case SIG('C', 'E'):
148 len = sizeof(struct SU_CE_s);
149 break;
150 case SIG('E', 'R'):
151 len = sizeof(struct SU_ER_s);
152 break;
153 case SIG('R', 'R'):
154 len = sizeof(struct RR_RR_s);
155 break;
156 case SIG('P', 'X'):
157 len = sizeof(struct RR_PX_s);
158 break;
159 case SIG('P', 'N'):
160 len = sizeof(struct RR_PN_s);
161 break;
162 case SIG('S', 'L'):
163 len = sizeof(struct RR_SL_s);
164 break;
165 case SIG('N', 'M'):
166 len = sizeof(struct RR_NM_s);
167 break;
168 case SIG('C', 'L'):
169 len = sizeof(struct RR_CL_s);
170 break;
171 case SIG('P', 'L'):
172 len = sizeof(struct RR_PL_s);
173 break;
174 case SIG('T', 'F'):
175 len = sizeof(struct RR_TF_s);
176 break;
177 case SIG('Z', 'F'):
178 len = sizeof(struct RR_ZF_s);
179 break;
180 default:
181 len = 0;
182 break;
183 }
184 len += offsetof(struct rock_ridge, u);
185 if (len > rs->len) {
186 printk(KERN_NOTICE "rock: directory entry would overflow "
187 "storage\n");
188 printk(KERN_NOTICE "rock: sig=0x%02x, size=%d, remaining=%d\n",
189 sig, len, rs->len);
190 return -EIO;
191 }
192 return 0;
193}
194
195/*
196 * return length of name field; 0: not found, -1: to be ignored
197 */
198int get_rock_ridge_filename(struct iso_directory_record *de,
199 char *retname, struct inode *inode)
200{
201 struct rock_state rs;
202 struct rock_ridge *rr;
203 int sig;
204 int retnamlen = 0;
205 int truncate = 0;
206 int ret = 0;
207 char *p;
208 int len;
209
210 if (!ISOFS_SB(inode->i_sb)->s_rock)
211 return 0;
212 *retname = 0;
213
214 init_rock_state(&rs, inode);
215 setup_rock_ridge(de, inode, &rs);
216repeat:
217
218 while (rs.len > 2) { /* There may be one byte for padding somewhere */
219 rr = (struct rock_ridge *)rs.chr;
220 /*
221 * Ignore rock ridge info if rr->len is out of range, but
222 * don't return -EIO because that would make the file
223 * invisible.
224 */
225 if (rr->len < 3)
226 goto out; /* Something got screwed up here */
227 sig = isonum_721(rs.chr);
228 if (rock_check_overflow(&rs, sig))
229 goto eio;
230 rs.chr += rr->len;
231 rs.len -= rr->len;
232 /*
233 * As above, just ignore the rock ridge info if rr->len
234 * is bogus.
235 */
236 if (rs.len < 0)
237 goto out; /* Something got screwed up here */
238
239 switch (sig) {
240 case SIG('R', 'R'):
241 if ((rr->u.RR.flags[0] & RR_NM) == 0)
242 goto out;
243 break;
244 case SIG('S', 'P'):
245 if (check_sp(rr, inode))
246 goto out;
247 break;
248 case SIG('C', 'E'):
249 rs.cont_extent = isonum_733(rr->u.CE.extent);
250 rs.cont_offset = isonum_733(rr->u.CE.offset);
251 rs.cont_size = isonum_733(rr->u.CE.size);
252 break;
253 case SIG('N', 'M'):
254 if (truncate)
255 break;
256 if (rr->len < 5)
257 break;
258 /*
259 * If the flags are 2 or 4, this indicates '.' or '..'.
260 * We don't want to do anything with this, because it
261 * screws up the code that calls us. We don't really
262 * care anyways, since we can just use the non-RR
263 * name.
264 */
265 if (rr->u.NM.flags & 6)
266 break;
267
268 if (rr->u.NM.flags & ~1) {
269 printk("Unsupported NM flag settings (%d)\n",
270 rr->u.NM.flags);
271 break;
272 }
273 len = rr->len - 5;
274 if (retnamlen + len >= 254) {
275 truncate = 1;
276 break;
277 }
278 p = memchr(rr->u.NM.name, '\0', len);
279 if (unlikely(p))
280 len = p - rr->u.NM.name;
281 memcpy(retname + retnamlen, rr->u.NM.name, len);
282 retnamlen += len;
283 retname[retnamlen] = '\0';
284 break;
285 case SIG('R', 'E'):
286 kfree(rs.buffer);
287 return -1;
288 default:
289 break;
290 }
291 }
292 ret = rock_continue(&rs);
293 if (ret == 0)
294 goto repeat;
295 if (ret == 1)
296 return retnamlen; /* If 0, this file did not have a NM field */
297out:
298 kfree(rs.buffer);
299 return ret;
300eio:
301 ret = -EIO;
302 goto out;
303}
304
305#define RR_REGARD_XA 1
306#define RR_RELOC_DE 2
307
308static int
309parse_rock_ridge_inode_internal(struct iso_directory_record *de,
310 struct inode *inode, int flags)
311{
312 int symlink_len = 0;
313 int cnt, sig;
314 unsigned int reloc_block;
315 struct inode *reloc;
316 struct rock_ridge *rr;
317 int rootflag;
318 struct rock_state rs;
319 int ret = 0;
320
321 if (!ISOFS_SB(inode->i_sb)->s_rock)
322 return 0;
323
324 init_rock_state(&rs, inode);
325 setup_rock_ridge(de, inode, &rs);
326 if (flags & RR_REGARD_XA) {
327 rs.chr += 14;
328 rs.len -= 14;
329 if (rs.len < 0)
330 rs.len = 0;
331 }
332
333repeat:
334 while (rs.len > 2) { /* There may be one byte for padding somewhere */
335 rr = (struct rock_ridge *)rs.chr;
336 /*
337 * Ignore rock ridge info if rr->len is out of range, but
338 * don't return -EIO because that would make the file
339 * invisible.
340 */
341 if (rr->len < 3)
342 goto out; /* Something got screwed up here */
343 sig = isonum_721(rs.chr);
344 if (rock_check_overflow(&rs, sig))
345 goto eio;
346 rs.chr += rr->len;
347 rs.len -= rr->len;
348 /*
349 * As above, just ignore the rock ridge info if rr->len
350 * is bogus.
351 */
352 if (rs.len < 0)
353 goto out; /* Something got screwed up here */
354
355 switch (sig) {
356#ifndef CONFIG_ZISOFS /* No flag for SF or ZF */
357 case SIG('R', 'R'):
358 if ((rr->u.RR.flags[0] &
359 (RR_PX | RR_TF | RR_SL | RR_CL)) == 0)
360 goto out;
361 break;
362#endif
363 case SIG('S', 'P'):
364 if (check_sp(rr, inode))
365 goto out;
366 break;
367 case SIG('C', 'E'):
368 rs.cont_extent = isonum_733(rr->u.CE.extent);
369 rs.cont_offset = isonum_733(rr->u.CE.offset);
370 rs.cont_size = isonum_733(rr->u.CE.size);
371 break;
372 case SIG('E', 'R'):
373 /* Invalid length of ER tag id? */
374 if (rr->u.ER.len_id + offsetof(struct rock_ridge, u.ER.data) > rr->len)
375 goto out;
376 ISOFS_SB(inode->i_sb)->s_rock = 1;
377 printk(KERN_DEBUG "ISO 9660 Extensions: ");
378 {
379 int p;
380 for (p = 0; p < rr->u.ER.len_id; p++)
381 printk(KERN_CONT "%c", rr->u.ER.data[p]);
382 }
383 printk(KERN_CONT "\n");
384 break;
385 case SIG('P', 'X'):
386 inode->i_mode = isonum_733(rr->u.PX.mode);
387 set_nlink(inode, isonum_733(rr->u.PX.n_links));
388 i_uid_write(inode, isonum_733(rr->u.PX.uid));
389 i_gid_write(inode, isonum_733(rr->u.PX.gid));
390 break;
391 case SIG('P', 'N'):
392 {
393 int high, low;
394 high = isonum_733(rr->u.PN.dev_high);
395 low = isonum_733(rr->u.PN.dev_low);
396 /*
397 * The Rock Ridge standard specifies that if
398 * sizeof(dev_t) <= 4, then the high field is
399 * unused, and the device number is completely
400 * stored in the low field. Some writers may
401 * ignore this subtlety,
402 * and as a result we test to see if the entire
403 * device number is
404 * stored in the low field, and use that.
405 */
406 if ((low & ~0xff) && high == 0) {
407 inode->i_rdev =
408 MKDEV(low >> 8, low & 0xff);
409 } else {
410 inode->i_rdev =
411 MKDEV(high, low);
412 }
413 }
414 break;
415 case SIG('T', 'F'):
416 /*
417 * Some RRIP writers incorrectly place ctime in the
418 * TF_CREATE field. Try to handle this correctly for
419 * either case.
420 */
421 /* Rock ridge never appears on a High Sierra disk */
422 cnt = 0;
423 if (rr->u.TF.flags & TF_CREATE) {
424 inode_set_ctime(inode,
425 iso_date(rr->u.TF.times[cnt++].time, 0),
426 0);
427 }
428 if (rr->u.TF.flags & TF_MODIFY) {
429 inode_set_mtime(inode,
430 iso_date(rr->u.TF.times[cnt++].time, 0),
431 0);
432 }
433 if (rr->u.TF.flags & TF_ACCESS) {
434 inode_set_atime(inode,
435 iso_date(rr->u.TF.times[cnt++].time, 0),
436 0);
437 }
438 if (rr->u.TF.flags & TF_ATTRIBUTES) {
439 inode_set_ctime(inode,
440 iso_date(rr->u.TF.times[cnt++].time, 0),
441 0);
442 }
443 break;
444 case SIG('S', 'L'):
445 {
446 int slen;
447 struct SL_component *slp;
448 struct SL_component *oldslp;
449 slen = rr->len - 5;
450 slp = &rr->u.SL.link;
451 inode->i_size = symlink_len;
452 while (slen > 1) {
453 rootflag = 0;
454 switch (slp->flags & ~1) {
455 case 0:
456 inode->i_size +=
457 slp->len;
458 break;
459 case 2:
460 inode->i_size += 1;
461 break;
462 case 4:
463 inode->i_size += 2;
464 break;
465 case 8:
466 rootflag = 1;
467 inode->i_size += 1;
468 break;
469 default:
470 printk("Symlink component flag "
471 "not implemented\n");
472 }
473 slen -= slp->len + 2;
474 oldslp = slp;
475 slp = (struct SL_component *)
476 (((char *)slp) + slp->len + 2);
477
478 if (slen < 2) {
479 if (((rr->u.SL.
480 flags & 1) != 0)
481 &&
482 ((oldslp->
483 flags & 1) == 0))
484 inode->i_size +=
485 1;
486 break;
487 }
488
489 /*
490 * If this component record isn't
491 * continued, then append a '/'.
492 */
493 if (!rootflag
494 && (oldslp->flags & 1) == 0)
495 inode->i_size += 1;
496 }
497 }
498 symlink_len = inode->i_size;
499 break;
500 case SIG('R', 'E'):
501 printk(KERN_WARNING "Attempt to read inode for "
502 "relocated directory\n");
503 goto out;
504 case SIG('C', 'L'):
505 if (flags & RR_RELOC_DE) {
506 printk(KERN_ERR
507 "ISOFS: Recursive directory relocation "
508 "is not supported\n");
509 goto eio;
510 }
511 reloc_block = isonum_733(rr->u.CL.location);
512 if (reloc_block == ISOFS_I(inode)->i_iget5_block &&
513 ISOFS_I(inode)->i_iget5_offset == 0) {
514 printk(KERN_ERR
515 "ISOFS: Directory relocation points to "
516 "itself\n");
517 goto eio;
518 }
519 ISOFS_I(inode)->i_first_extent = reloc_block;
520 reloc = isofs_iget_reloc(inode->i_sb, reloc_block, 0);
521 if (IS_ERR(reloc)) {
522 ret = PTR_ERR(reloc);
523 goto out;
524 }
525 inode->i_mode = reloc->i_mode;
526 set_nlink(inode, reloc->i_nlink);
527 inode->i_uid = reloc->i_uid;
528 inode->i_gid = reloc->i_gid;
529 inode->i_rdev = reloc->i_rdev;
530 inode->i_size = reloc->i_size;
531 inode->i_blocks = reloc->i_blocks;
532 inode_set_atime_to_ts(inode, inode_get_atime(reloc));
533 inode_set_ctime_to_ts(inode, inode_get_ctime(reloc));
534 inode_set_mtime_to_ts(inode, inode_get_mtime(reloc));
535 iput(reloc);
536 break;
537#ifdef CONFIG_ZISOFS
538 case SIG('Z', 'F'): {
539 int algo;
540
541 if (ISOFS_SB(inode->i_sb)->s_nocompress)
542 break;
543 algo = isonum_721(rr->u.ZF.algorithm);
544 if (algo == SIG('p', 'z')) {
545 int block_shift =
546 isonum_711(&rr->u.ZF.parms[1]);
547 if (block_shift > 17) {
548 printk(KERN_WARNING "isofs: "
549 "Can't handle ZF block "
550 "size of 2^%d\n",
551 block_shift);
552 } else {
553 /*
554 * Note: we don't change
555 * i_blocks here
556 */
557 ISOFS_I(inode)->i_file_format =
558 isofs_file_compressed;
559 /*
560 * Parameters to compression
561 * algorithm (header size,
562 * block size)
563 */
564 ISOFS_I(inode)->i_format_parm[0] =
565 isonum_711(&rr->u.ZF.parms[0]);
566 ISOFS_I(inode)->i_format_parm[1] =
567 isonum_711(&rr->u.ZF.parms[1]);
568 inode->i_size =
569 isonum_733(rr->u.ZF.
570 real_size);
571 }
572 } else {
573 printk(KERN_WARNING
574 "isofs: Unknown ZF compression "
575 "algorithm: %c%c\n",
576 rr->u.ZF.algorithm[0],
577 rr->u.ZF.algorithm[1]);
578 }
579 break;
580 }
581#endif
582 default:
583 break;
584 }
585 }
586 ret = rock_continue(&rs);
587 if (ret == 0)
588 goto repeat;
589 if (ret == 1)
590 ret = 0;
591out:
592 kfree(rs.buffer);
593 return ret;
594eio:
595 ret = -EIO;
596 goto out;
597}
598
599static char *get_symlink_chunk(char *rpnt, struct rock_ridge *rr, char *plimit)
600{
601 int slen;
602 int rootflag;
603 struct SL_component *oldslp;
604 struct SL_component *slp;
605 slen = rr->len - 5;
606 slp = &rr->u.SL.link;
607 while (slen > 1) {
608 rootflag = 0;
609 switch (slp->flags & ~1) {
610 case 0:
611 if (slp->len > plimit - rpnt)
612 return NULL;
613 memcpy(rpnt, slp->text, slp->len);
614 rpnt += slp->len;
615 break;
616 case 2:
617 if (rpnt >= plimit)
618 return NULL;
619 *rpnt++ = '.';
620 break;
621 case 4:
622 if (2 > plimit - rpnt)
623 return NULL;
624 *rpnt++ = '.';
625 *rpnt++ = '.';
626 break;
627 case 8:
628 if (rpnt >= plimit)
629 return NULL;
630 rootflag = 1;
631 *rpnt++ = '/';
632 break;
633 default:
634 printk("Symlink component flag not implemented (%d)\n",
635 slp->flags);
636 }
637 slen -= slp->len + 2;
638 oldslp = slp;
639 slp = (struct SL_component *)((char *)slp + slp->len + 2);
640
641 if (slen < 2) {
642 /*
643 * If there is another SL record, and this component
644 * record isn't continued, then add a slash.
645 */
646 if ((!rootflag) && (rr->u.SL.flags & 1) &&
647 !(oldslp->flags & 1)) {
648 if (rpnt >= plimit)
649 return NULL;
650 *rpnt++ = '/';
651 }
652 break;
653 }
654
655 /*
656 * If this component record isn't continued, then append a '/'.
657 */
658 if (!rootflag && !(oldslp->flags & 1)) {
659 if (rpnt >= plimit)
660 return NULL;
661 *rpnt++ = '/';
662 }
663 }
664 return rpnt;
665}
666
667int parse_rock_ridge_inode(struct iso_directory_record *de, struct inode *inode,
668 int relocated)
669{
670 int flags = relocated ? RR_RELOC_DE : 0;
671 int result = parse_rock_ridge_inode_internal(de, inode, flags);
672
673 /*
674 * if rockridge flag was reset and we didn't look for attributes
675 * behind eventual XA attributes, have a look there
676 */
677 if ((ISOFS_SB(inode->i_sb)->s_rock_offset == -1)
678 && (ISOFS_SB(inode->i_sb)->s_rock == 2)) {
679 result = parse_rock_ridge_inode_internal(de, inode,
680 flags | RR_REGARD_XA);
681 }
682 return result;
683}
684
685/*
686 * read_folio() for symlinks: reads symlink contents into the folio and either
687 * makes it uptodate and returns 0 or returns error (-EIO)
688 */
689static int rock_ridge_symlink_read_folio(struct file *file, struct folio *folio)
690{
691 struct page *page = &folio->page;
692 struct inode *inode = page->mapping->host;
693 struct iso_inode_info *ei = ISOFS_I(inode);
694 struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb);
695 char *link = page_address(page);
696 unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
697 struct buffer_head *bh;
698 char *rpnt = link;
699 unsigned char *pnt;
700 struct iso_directory_record *raw_de;
701 unsigned long block, offset;
702 int sig;
703 struct rock_ridge *rr;
704 struct rock_state rs;
705 int ret;
706
707 if (!sbi->s_rock)
708 goto error;
709
710 init_rock_state(&rs, inode);
711 block = ei->i_iget5_block;
712 bh = sb_bread(inode->i_sb, block);
713 if (!bh)
714 goto out_noread;
715
716 offset = ei->i_iget5_offset;
717 pnt = (unsigned char *)bh->b_data + offset;
718
719 raw_de = (struct iso_directory_record *)pnt;
720
721 /*
722 * If we go past the end of the buffer, there is some sort of error.
723 */
724 if (offset + *pnt > bufsize)
725 goto out_bad_span;
726
727 /*
728 * Now test for possible Rock Ridge extensions which will override
729 * some of these numbers in the inode structure.
730 */
731
732 setup_rock_ridge(raw_de, inode, &rs);
733
734repeat:
735 while (rs.len > 2) { /* There may be one byte for padding somewhere */
736 rr = (struct rock_ridge *)rs.chr;
737 if (rr->len < 3)
738 goto out; /* Something got screwed up here */
739 sig = isonum_721(rs.chr);
740 if (rock_check_overflow(&rs, sig))
741 goto out;
742 rs.chr += rr->len;
743 rs.len -= rr->len;
744 if (rs.len < 0)
745 goto out; /* corrupted isofs */
746
747 switch (sig) {
748 case SIG('R', 'R'):
749 if ((rr->u.RR.flags[0] & RR_SL) == 0)
750 goto out;
751 break;
752 case SIG('S', 'P'):
753 if (check_sp(rr, inode))
754 goto out;
755 break;
756 case SIG('S', 'L'):
757 rpnt = get_symlink_chunk(rpnt, rr,
758 link + (PAGE_SIZE - 1));
759 if (rpnt == NULL)
760 goto out;
761 break;
762 case SIG('C', 'E'):
763 /* This tells is if there is a continuation record */
764 rs.cont_extent = isonum_733(rr->u.CE.extent);
765 rs.cont_offset = isonum_733(rr->u.CE.offset);
766 rs.cont_size = isonum_733(rr->u.CE.size);
767 break;
768 default:
769 break;
770 }
771 }
772 ret = rock_continue(&rs);
773 if (ret == 0)
774 goto repeat;
775 if (ret < 0)
776 goto fail;
777
778 if (rpnt == link)
779 goto fail;
780 brelse(bh);
781 *rpnt = '\0';
782 SetPageUptodate(page);
783 unlock_page(page);
784 return 0;
785
786 /* error exit from macro */
787out:
788 kfree(rs.buffer);
789 goto fail;
790out_noread:
791 printk("unable to read i-node block");
792 goto fail;
793out_bad_span:
794 printk("symlink spans iso9660 blocks\n");
795fail:
796 brelse(bh);
797error:
798 SetPageError(page);
799 unlock_page(page);
800 return -EIO;
801}
802
803const struct address_space_operations isofs_symlink_aops = {
804 .read_folio = rock_ridge_symlink_read_folio
805};