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 | |
27 | struct 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 | |
43 | static 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(sb: inode->i_sb)->s_rock_offset = rr->u.SP.skip; |
50 | return 0; |
51 | } |
52 | |
53 | static 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(sb: inode->i_sb)->s_rock_offset != -1) { |
65 | rs->len -= ISOFS_SB(sb: inode->i_sb)->s_rock_offset; |
66 | rs->chr += ISOFS_SB(sb: inode->i_sb)->s_rock_offset; |
67 | if (rs->len < 0) |
68 | rs->len = 0; |
69 | } |
70 | } |
71 | |
72 | static 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 | */ |
85 | static 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(objp: 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(size: 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(sb: rs->inode->i_sb, block: 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 | } |
129 | out: |
130 | kfree(objp: 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 | */ |
139 | static 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 | */ |
198 | int 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(sb: inode->i_sb)->s_rock) |
211 | return 0; |
212 | *retname = 0; |
213 | |
214 | init_rock_state(rs: &rs, inode); |
215 | setup_rock_ridge(de, inode, rs: &rs); |
216 | repeat: |
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(p: rs.chr); |
228 | if (rock_check_overflow(rs: &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(p: rr->u.CE.extent); |
250 | rs.cont_offset = isonum_733(p: rr->u.CE.offset); |
251 | rs.cont_size = isonum_733(p: 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(p: rr->u.NM.name, c: '\0', size: 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(objp: rs.buffer); |
287 | return -1; |
288 | default: |
289 | break; |
290 | } |
291 | } |
292 | ret = rock_continue(rs: &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 */ |
297 | out: |
298 | kfree(objp: rs.buffer); |
299 | return ret; |
300 | eio: |
301 | ret = -EIO; |
302 | goto out; |
303 | } |
304 | |
305 | #define RR_REGARD_XA 1 |
306 | #define RR_RELOC_DE 2 |
307 | |
308 | static int |
309 | parse_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(sb: inode->i_sb)->s_rock) |
322 | return 0; |
323 | |
324 | init_rock_state(rs: &rs, inode); |
325 | setup_rock_ridge(de, inode, rs: &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 | |
333 | repeat: |
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(p: rs.chr); |
344 | if (rock_check_overflow(rs: &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(p: rr->u.CE.extent); |
369 | rs.cont_offset = isonum_733(p: rr->u.CE.offset); |
370 | rs.cont_size = isonum_733(p: 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(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(p: rr->u.PX.mode); |
387 | set_nlink(inode, nlink: isonum_733(p: rr->u.PX.n_links)); |
388 | i_uid_write(inode, uid: isonum_733(p: rr->u.PX.uid)); |
389 | i_gid_write(inode, gid: isonum_733(p: rr->u.PX.gid)); |
390 | break; |
391 | case SIG('P', 'N'): |
392 | { |
393 | int high, low; |
394 | high = isonum_733(p: rr->u.PN.dev_high); |
395 | low = isonum_733(p: 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 | sec: iso_date(rr->u.TF.times[cnt++].time, 0), |
426 | nsec: 0); |
427 | } |
428 | if (rr->u.TF.flags & TF_MODIFY) { |
429 | inode_set_mtime(inode, |
430 | sec: iso_date(rr->u.TF.times[cnt++].time, 0), |
431 | nsec: 0); |
432 | } |
433 | if (rr->u.TF.flags & TF_ACCESS) { |
434 | inode_set_atime(inode, |
435 | sec: iso_date(rr->u.TF.times[cnt++].time, 0), |
436 | nsec: 0); |
437 | } |
438 | if (rr->u.TF.flags & TF_ATTRIBUTES) { |
439 | inode_set_ctime(inode, |
440 | sec: iso_date(rr->u.TF.times[cnt++].time, 0), |
441 | nsec: 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(p: 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(sb: inode->i_sb, block: reloc_block, offset: 0); |
521 | if (IS_ERR(ptr: reloc)) { |
522 | ret = PTR_ERR(ptr: reloc); |
523 | goto out; |
524 | } |
525 | inode->i_mode = reloc->i_mode; |
526 | set_nlink(inode, nlink: 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, ts: inode_get_atime(inode: reloc)); |
533 | inode_set_ctime_to_ts(inode, ts: inode_get_ctime(inode: reloc)); |
534 | inode_set_mtime_to_ts(inode, ts: inode_get_mtime(inode: reloc)); |
535 | iput(reloc); |
536 | break; |
537 | #ifdef CONFIG_ZISOFS |
538 | case SIG('Z', 'F'): { |
539 | int algo; |
540 | |
541 | if (ISOFS_SB(sb: inode->i_sb)->s_nocompress) |
542 | break; |
543 | algo = isonum_721(p: rr->u.ZF.algorithm); |
544 | if (algo == SIG('p', 'z')) { |
545 | int block_shift = |
546 | isonum_711(p: &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(p: &rr->u.ZF.parms[0]); |
566 | ISOFS_I(inode)->i_format_parm[1] = |
567 | isonum_711(p: &rr->u.ZF.parms[1]); |
568 | inode->i_size = |
569 | isonum_733(p: 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: &rs); |
587 | if (ret == 0) |
588 | goto repeat; |
589 | if (ret == 1) |
590 | ret = 0; |
591 | out: |
592 | kfree(objp: rs.buffer); |
593 | return ret; |
594 | eio: |
595 | ret = -EIO; |
596 | goto out; |
597 | } |
598 | |
599 | static 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 | |
667 | int 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(sb: inode->i_sb)->s_rock_offset == -1) |
678 | && (ISOFS_SB(sb: inode->i_sb)->s_rock == 2)) { |
679 | result = parse_rock_ridge_inode_internal(de, inode, |
680 | flags: 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 | */ |
689 | static 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(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: &rs, inode); |
711 | block = ei->i_iget5_block; |
712 | bh = sb_bread(sb: 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(de: raw_de, inode, rs: &rs); |
733 | |
734 | repeat: |
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(p: rs.chr); |
740 | if (rock_check_overflow(rs: &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 | plimit: 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(p: rr->u.CE.extent); |
765 | rs.cont_offset = isonum_733(p: rr->u.CE.offset); |
766 | rs.cont_size = isonum_733(p: rr->u.CE.size); |
767 | break; |
768 | default: |
769 | break; |
770 | } |
771 | } |
772 | ret = rock_continue(rs: &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 */ |
787 | out: |
788 | kfree(objp: rs.buffer); |
789 | goto fail; |
790 | out_noread: |
791 | printk("unable to read i-node block" ); |
792 | goto fail; |
793 | out_bad_span: |
794 | printk("symlink spans iso9660 blocks\n" ); |
795 | fail: |
796 | brelse(bh); |
797 | error: |
798 | SetPageError(page); |
799 | unlock_page(page); |
800 | return -EIO; |
801 | } |
802 | |
803 | const struct address_space_operations isofs_symlink_aops = { |
804 | .read_folio = rock_ridge_symlink_read_folio |
805 | }; |
806 | |