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-rw-r--r--fs/isofs/rock.c565
1 files changed, 565 insertions, 0 deletions
diff --git a/fs/isofs/rock.c b/fs/isofs/rock.c
new file mode 100644
index 000000000000..8bdd3e409543
--- /dev/null
+++ b/fs/isofs/rock.c
@@ -0,0 +1,565 @@
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/stat.h>
10#include <linux/time.h>
11#include <linux/iso_fs.h>
12#include <linux/string.h>
13#include <linux/mm.h>
14#include <linux/slab.h>
15#include <linux/pagemap.h>
16#include <linux/smp_lock.h>
17#include <linux/buffer_head.h>
18#include <asm/page.h>
19
20#include "rock.h"
21
22/* These functions are designed to read the system areas of a directory record
23 * and extract relevant information. There are different functions provided
24 * depending upon what information we need at the time. One function fills
25 * out an inode structure, a second one extracts a filename, a third one
26 * returns a symbolic link name, and a fourth one returns the extent number
27 * for the file. */
28
29#define SIG(A,B) ((A) | ((B) << 8)) /* isonum_721() */
30
31
32/* This is a way of ensuring that we have something in the system
33 use fields that is compatible with Rock Ridge */
34#define CHECK_SP(FAIL) \
35 if(rr->u.SP.magic[0] != 0xbe) FAIL; \
36 if(rr->u.SP.magic[1] != 0xef) FAIL; \
37 ISOFS_SB(inode->i_sb)->s_rock_offset=rr->u.SP.skip;
38/* We define a series of macros because each function must do exactly the
39 same thing in certain places. We use the macros to ensure that everything
40 is done correctly */
41
42#define CONTINUE_DECLS \
43 int cont_extent = 0, cont_offset = 0, cont_size = 0; \
44 void *buffer = NULL
45
46#define CHECK_CE \
47 {cont_extent = isonum_733(rr->u.CE.extent); \
48 cont_offset = isonum_733(rr->u.CE.offset); \
49 cont_size = isonum_733(rr->u.CE.size);}
50
51#define SETUP_ROCK_RIDGE(DE,CHR,LEN) \
52 {LEN= sizeof(struct iso_directory_record) + DE->name_len[0]; \
53 if(LEN & 1) LEN++; \
54 CHR = ((unsigned char *) DE) + LEN; \
55 LEN = *((unsigned char *) DE) - LEN; \
56 if (LEN<0) LEN=0; \
57 if (ISOFS_SB(inode->i_sb)->s_rock_offset!=-1) \
58 { \
59 LEN-=ISOFS_SB(inode->i_sb)->s_rock_offset; \
60 CHR+=ISOFS_SB(inode->i_sb)->s_rock_offset; \
61 if (LEN<0) LEN=0; \
62 } \
63}
64
65#define MAYBE_CONTINUE(LABEL,DEV) \
66 {if (buffer) { kfree(buffer); buffer = NULL; } \
67 if (cont_extent){ \
68 int block, offset, offset1; \
69 struct buffer_head * pbh; \
70 buffer = kmalloc(cont_size,GFP_KERNEL); \
71 if (!buffer) goto out; \
72 block = cont_extent; \
73 offset = cont_offset; \
74 offset1 = 0; \
75 pbh = sb_bread(DEV->i_sb, block); \
76 if(pbh){ \
77 if (offset > pbh->b_size || offset + cont_size > pbh->b_size){ \
78 brelse(pbh); \
79 goto out; \
80 } \
81 memcpy(buffer + offset1, pbh->b_data + offset, cont_size - offset1); \
82 brelse(pbh); \
83 chr = (unsigned char *) buffer; \
84 len = cont_size; \
85 cont_extent = 0; \
86 cont_size = 0; \
87 cont_offset = 0; \
88 goto LABEL; \
89 } \
90 printk("Unable to read rock-ridge attributes\n"); \
91 }}
92
93/* return length of name field; 0: not found, -1: to be ignored */
94int get_rock_ridge_filename(struct iso_directory_record * de,
95 char * retname, struct inode * inode)
96{
97 int len;
98 unsigned char * chr;
99 CONTINUE_DECLS;
100 int retnamlen = 0, truncate=0;
101
102 if (!ISOFS_SB(inode->i_sb)->s_rock) return 0;
103 *retname = 0;
104
105 SETUP_ROCK_RIDGE(de, chr, len);
106 repeat:
107 {
108 struct rock_ridge * rr;
109 int sig;
110
111 while (len > 2){ /* There may be one byte for padding somewhere */
112 rr = (struct rock_ridge *) chr;
113 if (rr->len < 3) goto out; /* Something got screwed up here */
114 sig = isonum_721(chr);
115 chr += rr->len;
116 len -= rr->len;
117 if (len < 0) goto out; /* corrupted isofs */
118
119 switch(sig){
120 case SIG('R','R'):
121 if((rr->u.RR.flags[0] & RR_NM) == 0) goto out;
122 break;
123 case SIG('S','P'):
124 CHECK_SP(goto out);
125 break;
126 case SIG('C','E'):
127 CHECK_CE;
128 break;
129 case SIG('N','M'):
130 if (truncate) break;
131 if (rr->len < 5) break;
132 /*
133 * If the flags are 2 or 4, this indicates '.' or '..'.
134 * We don't want to do anything with this, because it
135 * screws up the code that calls us. We don't really
136 * care anyways, since we can just use the non-RR
137 * name.
138 */
139 if (rr->u.NM.flags & 6) {
140 break;
141 }
142
143 if (rr->u.NM.flags & ~1) {
144 printk("Unsupported NM flag settings (%d)\n",rr->u.NM.flags);
145 break;
146 }
147 if((strlen(retname) + rr->len - 5) >= 254) {
148 truncate = 1;
149 break;
150 }
151 strncat(retname, rr->u.NM.name, rr->len - 5);
152 retnamlen += rr->len - 5;
153 break;
154 case SIG('R','E'):
155 if (buffer) kfree(buffer);
156 return -1;
157 default:
158 break;
159 }
160 }
161 }
162 MAYBE_CONTINUE(repeat,inode);
163 if (buffer) kfree(buffer);
164 return retnamlen; /* If 0, this file did not have a NM field */
165 out:
166 if(buffer) kfree(buffer);
167 return 0;
168}
169
170static int
171parse_rock_ridge_inode_internal(struct iso_directory_record *de,
172 struct inode *inode, int regard_xa)
173{
174 int len;
175 unsigned char * chr;
176 int symlink_len = 0;
177 CONTINUE_DECLS;
178
179 if (!ISOFS_SB(inode->i_sb)->s_rock) return 0;
180
181 SETUP_ROCK_RIDGE(de, chr, len);
182 if (regard_xa)
183 {
184 chr+=14;
185 len-=14;
186 if (len<0) len=0;
187 }
188
189 repeat:
190 {
191 int cnt, sig;
192 struct inode * reloc;
193 struct rock_ridge * rr;
194 int rootflag;
195
196 while (len > 2){ /* There may be one byte for padding somewhere */
197 rr = (struct rock_ridge *) chr;
198 if (rr->len < 3) goto out; /* Something got screwed up here */
199 sig = isonum_721(chr);
200 chr += rr->len;
201 len -= rr->len;
202 if (len < 0) goto out; /* corrupted isofs */
203
204 switch(sig){
205#ifndef CONFIG_ZISOFS /* No flag for SF or ZF */
206 case SIG('R','R'):
207 if((rr->u.RR.flags[0] &
208 (RR_PX | RR_TF | RR_SL | RR_CL)) == 0) goto out;
209 break;
210#endif
211 case SIG('S','P'):
212 CHECK_SP(goto out);
213 break;
214 case SIG('C','E'):
215 CHECK_CE;
216 break;
217 case SIG('E','R'):
218 ISOFS_SB(inode->i_sb)->s_rock = 1;
219 printk(KERN_DEBUG "ISO 9660 Extensions: ");
220 { int p;
221 for(p=0;p<rr->u.ER.len_id;p++) printk("%c",rr->u.ER.data[p]);
222 }
223 printk("\n");
224 break;
225 case SIG('P','X'):
226 inode->i_mode = isonum_733(rr->u.PX.mode);
227 inode->i_nlink = isonum_733(rr->u.PX.n_links);
228 inode->i_uid = isonum_733(rr->u.PX.uid);
229 inode->i_gid = isonum_733(rr->u.PX.gid);
230 break;
231 case SIG('P','N'):
232 { int high, low;
233 high = isonum_733(rr->u.PN.dev_high);
234 low = isonum_733(rr->u.PN.dev_low);
235 /*
236 * The Rock Ridge standard specifies that if sizeof(dev_t) <= 4,
237 * then the high field is unused, and the device number is completely
238 * stored in the low field. Some writers may ignore this subtlety,
239 * and as a result we test to see if the entire device number is
240 * stored in the low field, and use that.
241 */
242 if((low & ~0xff) && high == 0) {
243 inode->i_rdev = MKDEV(low >> 8, low & 0xff);
244 } else {
245 inode->i_rdev = MKDEV(high, low);
246 }
247 }
248 break;
249 case SIG('T','F'):
250 /* Some RRIP writers incorrectly place ctime in the TF_CREATE field.
251 Try to handle this correctly for either case. */
252 cnt = 0; /* Rock ridge never appears on a High Sierra disk */
253 if(rr->u.TF.flags & TF_CREATE) {
254 inode->i_ctime.tv_sec = iso_date(rr->u.TF.times[cnt++].time, 0);
255 inode->i_ctime.tv_nsec = 0;
256 }
257 if(rr->u.TF.flags & TF_MODIFY) {
258 inode->i_mtime.tv_sec = iso_date(rr->u.TF.times[cnt++].time, 0);
259 inode->i_mtime.tv_nsec = 0;
260 }
261 if(rr->u.TF.flags & TF_ACCESS) {
262 inode->i_atime.tv_sec = iso_date(rr->u.TF.times[cnt++].time, 0);
263 inode->i_atime.tv_nsec = 0;
264 }
265 if(rr->u.TF.flags & TF_ATTRIBUTES) {
266 inode->i_ctime.tv_sec = iso_date(rr->u.TF.times[cnt++].time, 0);
267 inode->i_ctime.tv_nsec = 0;
268 }
269 break;
270 case SIG('S','L'):
271 {int slen;
272 struct SL_component * slp;
273 struct SL_component * oldslp;
274 slen = rr->len - 5;
275 slp = &rr->u.SL.link;
276 inode->i_size = symlink_len;
277 while (slen > 1){
278 rootflag = 0;
279 switch(slp->flags &~1){
280 case 0:
281 inode->i_size += slp->len;
282 break;
283 case 2:
284 inode->i_size += 1;
285 break;
286 case 4:
287 inode->i_size += 2;
288 break;
289 case 8:
290 rootflag = 1;
291 inode->i_size += 1;
292 break;
293 default:
294 printk("Symlink component flag not implemented\n");
295 }
296 slen -= slp->len + 2;
297 oldslp = slp;
298 slp = (struct SL_component *) (((char *) slp) + slp->len + 2);
299
300 if(slen < 2) {
301 if( ((rr->u.SL.flags & 1) != 0)
302 && ((oldslp->flags & 1) == 0) ) inode->i_size += 1;
303 break;
304 }
305
306 /*
307 * If this component record isn't continued, then append a '/'.
308 */
309 if (!rootflag && (oldslp->flags & 1) == 0)
310 inode->i_size += 1;
311 }
312 }
313 symlink_len = inode->i_size;
314 break;
315 case SIG('R','E'):
316 printk(KERN_WARNING "Attempt to read inode for relocated directory\n");
317 goto out;
318 case SIG('C','L'):
319 ISOFS_I(inode)->i_first_extent = isonum_733(rr->u.CL.location);
320 reloc = isofs_iget(inode->i_sb, ISOFS_I(inode)->i_first_extent, 0);
321 if (!reloc)
322 goto out;
323 inode->i_mode = reloc->i_mode;
324 inode->i_nlink = reloc->i_nlink;
325 inode->i_uid = reloc->i_uid;
326 inode->i_gid = reloc->i_gid;
327 inode->i_rdev = reloc->i_rdev;
328 inode->i_size = reloc->i_size;
329 inode->i_blocks = reloc->i_blocks;
330 inode->i_atime = reloc->i_atime;
331 inode->i_ctime = reloc->i_ctime;
332 inode->i_mtime = reloc->i_mtime;
333 iput(reloc);
334 break;
335#ifdef CONFIG_ZISOFS
336 case SIG('Z','F'):
337 if ( !ISOFS_SB(inode->i_sb)->s_nocompress ) {
338 int algo;
339 algo = isonum_721(rr->u.ZF.algorithm);
340 if ( algo == SIG('p','z') ) {
341 int block_shift = isonum_711(&rr->u.ZF.parms[1]);
342 if ( block_shift < PAGE_CACHE_SHIFT || block_shift > 17 ) {
343 printk(KERN_WARNING "isofs: Can't handle ZF block size of 2^%d\n", block_shift);
344 } else {
345 /* Note: we don't change i_blocks here */
346 ISOFS_I(inode)->i_file_format = isofs_file_compressed;
347 /* Parameters to compression algorithm (header size, block size) */
348 ISOFS_I(inode)->i_format_parm[0] = isonum_711(&rr->u.ZF.parms[0]);
349 ISOFS_I(inode)->i_format_parm[1] = isonum_711(&rr->u.ZF.parms[1]);
350 inode->i_size = isonum_733(rr->u.ZF.real_size);
351 }
352 } else {
353 printk(KERN_WARNING "isofs: Unknown ZF compression algorithm: %c%c\n",
354 rr->u.ZF.algorithm[0], rr->u.ZF.algorithm[1]);
355 }
356 }
357 break;
358#endif
359 default:
360 break;
361 }
362 }
363 }
364 MAYBE_CONTINUE(repeat,inode);
365 out:
366 if(buffer) kfree(buffer);
367 return 0;
368}
369
370static char *get_symlink_chunk(char *rpnt, struct rock_ridge *rr, char *plimit)
371{
372 int slen;
373 int rootflag;
374 struct SL_component *oldslp;
375 struct SL_component *slp;
376 slen = rr->len - 5;
377 slp = &rr->u.SL.link;
378 while (slen > 1) {
379 rootflag = 0;
380 switch (slp->flags & ~1) {
381 case 0:
382 if (slp->len > plimit - rpnt)
383 return NULL;
384 memcpy(rpnt, slp->text, slp->len);
385 rpnt+=slp->len;
386 break;
387 case 2:
388 if (rpnt >= plimit)
389 return NULL;
390 *rpnt++='.';
391 break;
392 case 4:
393 if (2 > plimit - rpnt)
394 return NULL;
395 *rpnt++='.';
396 *rpnt++='.';
397 break;
398 case 8:
399 if (rpnt >= plimit)
400 return NULL;
401 rootflag = 1;
402 *rpnt++='/';
403 break;
404 default:
405 printk("Symlink component flag not implemented (%d)\n",
406 slp->flags);
407 }
408 slen -= slp->len + 2;
409 oldslp = slp;
410 slp = (struct SL_component *) ((char *) slp + slp->len + 2);
411
412 if (slen < 2) {
413 /*
414 * If there is another SL record, and this component
415 * record isn't continued, then add a slash.
416 */
417 if ((!rootflag) && (rr->u.SL.flags & 1) &&
418 !(oldslp->flags & 1)) {
419 if (rpnt >= plimit)
420 return NULL;
421 *rpnt++='/';
422 }
423 break;
424 }
425
426 /*
427 * If this component record isn't continued, then append a '/'.
428 */
429 if (!rootflag && !(oldslp->flags & 1)) {
430 if (rpnt >= plimit)
431 return NULL;
432 *rpnt++='/';
433 }
434 }
435 return rpnt;
436}
437
438int parse_rock_ridge_inode(struct iso_directory_record * de,
439 struct inode * inode)
440{
441 int result=parse_rock_ridge_inode_internal(de,inode,0);
442 /* if rockridge flag was reset and we didn't look for attributes
443 * behind eventual XA attributes, have a look there */
444 if ((ISOFS_SB(inode->i_sb)->s_rock_offset==-1)
445 &&(ISOFS_SB(inode->i_sb)->s_rock==2))
446 {
447 result=parse_rock_ridge_inode_internal(de,inode,14);
448 }
449 return result;
450}
451
452/* readpage() for symlinks: reads symlink contents into the page and either
453 makes it uptodate and returns 0 or returns error (-EIO) */
454
455static int rock_ridge_symlink_readpage(struct file *file, struct page *page)
456{
457 struct inode *inode = page->mapping->host;
458 struct iso_inode_info *ei = ISOFS_I(inode);
459 char *link = kmap(page);
460 unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
461 struct buffer_head *bh;
462 char *rpnt = link;
463 unsigned char *pnt;
464 struct iso_directory_record *raw_inode;
465 CONTINUE_DECLS;
466 unsigned long block, offset;
467 int sig;
468 int len;
469 unsigned char *chr;
470 struct rock_ridge *rr;
471
472 if (!ISOFS_SB(inode->i_sb)->s_rock)
473 goto error;
474
475 block = ei->i_iget5_block;
476 lock_kernel();
477 bh = sb_bread(inode->i_sb, block);
478 if (!bh)
479 goto out_noread;
480
481 offset = ei->i_iget5_offset;
482 pnt = (unsigned char *) bh->b_data + offset;
483
484 raw_inode = (struct iso_directory_record *) pnt;
485
486 /*
487 * If we go past the end of the buffer, there is some sort of error.
488 */
489 if (offset + *pnt > bufsize)
490 goto out_bad_span;
491
492 /* Now test for possible Rock Ridge extensions which will override
493 some of these numbers in the inode structure. */
494
495 SETUP_ROCK_RIDGE(raw_inode, chr, len);
496
497 repeat:
498 while (len > 2) { /* There may be one byte for padding somewhere */
499 rr = (struct rock_ridge *) chr;
500 if (rr->len < 3)
501 goto out; /* Something got screwed up here */
502 sig = isonum_721(chr);
503 chr += rr->len;
504 len -= rr->len;
505 if (len < 0)
506 goto out; /* corrupted isofs */
507
508 switch (sig) {
509 case SIG('R', 'R'):
510 if ((rr->u.RR.flags[0] & RR_SL) == 0)
511 goto out;
512 break;
513 case SIG('S', 'P'):
514 CHECK_SP(goto out);
515 break;
516 case SIG('S', 'L'):
517 rpnt = get_symlink_chunk(rpnt, rr,
518 link + (PAGE_SIZE - 1));
519 if (rpnt == NULL)
520 goto out;
521 break;
522 case SIG('C', 'E'):
523 /* This tells is if there is a continuation record */
524 CHECK_CE;
525 default:
526 break;
527 }
528 }
529 MAYBE_CONTINUE(repeat, inode);
530 if (buffer)
531 kfree(buffer);
532
533 if (rpnt == link)
534 goto fail;
535 brelse(bh);
536 *rpnt = '\0';
537 unlock_kernel();
538 SetPageUptodate(page);
539 kunmap(page);
540 unlock_page(page);
541 return 0;
542
543 /* error exit from macro */
544 out:
545 if (buffer)
546 kfree(buffer);
547 goto fail;
548 out_noread:
549 printk("unable to read i-node block");
550 goto fail;
551 out_bad_span:
552 printk("symlink spans iso9660 blocks\n");
553 fail:
554 brelse(bh);
555 unlock_kernel();
556 error:
557 SetPageError(page);
558 kunmap(page);
559 unlock_page(page);
560 return -EIO;
561}
562
563struct address_space_operations isofs_symlink_aops = {
564 .readpage = rock_ridge_symlink_readpage
565};
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-21 06:16:22 -0500