1 /* $NetBSD: cd9660.c,v 1.5 1997/06/26 19:11:33 drochner Exp $ */
2
3 /*
4 * Copyright (C) 1996 Wolfgang Solfrank.
5 * Copyright (C) 1996 TooLs GmbH.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by TooLs GmbH.
19 * 4. The name of TooLs GmbH may not be used to endorse or promote products
20 * derived from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
27 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
28 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
30 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
31 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36
37 /*
38 * Stand-alone ISO9660 file reading package.
39 *
40 * Note: This doesn't support Rock Ridge extensions, extended attributes,
41 * blocksizes other than 2048 bytes, multi-extent files, etc.
42 */
43 #include <sys/param.h>
44 #include <string.h>
45 #include <stdbool.h>
46 #include <sys/dirent.h>
47 #include <fs/cd9660/iso.h>
48 #include <fs/cd9660/cd9660_rrip.h>
49
50 #include "stand.h"
51
52 #define SUSP_CONTINUATION "CE"
53 #define SUSP_PRESENT "SP"
54 #define SUSP_STOP "ST"
55 #define SUSP_EXTREF "ER"
56 #define RRIP_NAME "NM"
57
58 typedef struct {
59 ISO_SUSP_HEADER h;
60 u_char signature [ISODCL ( 5, 6)];
61 u_char len_skp [ISODCL ( 7, 7)]; /* 711 */
62 } ISO_SUSP_PRESENT;
63
64 static int buf_read_file(struct open_file *f, char **buf_p,
65 size_t *size_p);
66 static int cd9660_open(const char *path, struct open_file *f);
67 static int cd9660_close(struct open_file *f);
68 static int cd9660_read(struct open_file *f, void *buf, size_t size,
69 size_t *resid);
70 static off_t cd9660_seek(struct open_file *f, off_t offset, int where);
71 static int cd9660_stat(struct open_file *f, struct stat *sb);
72 static int cd9660_readdir(struct open_file *f, struct dirent *d);
73 static int dirmatch(struct open_file *f, const char *path,
74 struct iso_directory_record *dp, int use_rrip, int lenskip);
75 static int rrip_check(struct open_file *f, struct iso_directory_record *dp,
76 int *lenskip);
77 static char *rrip_lookup_name(struct open_file *f,
78 struct iso_directory_record *dp, int lenskip, size_t *len);
79 static ISO_SUSP_HEADER *susp_lookup_record(struct open_file *f,
80 const char *identifier, struct iso_directory_record *dp,
81 int lenskip);
82
83 struct fs_ops cd9660_fsops = {
84 "cd9660",
85 cd9660_open,
86 cd9660_close,
87 cd9660_read,
88 null_write,
89 cd9660_seek,
90 cd9660_stat,
91 cd9660_readdir
92 };
93
94 #define F_ISDIR 0x0001 /* Directory */
95 #define F_ROOTDIR 0x0002 /* Root directory */
96 #define F_RR 0x0004 /* Rock Ridge on this volume */
97
98 struct file {
99 int f_flags; /* file flags */
100 off_t f_off; /* Current offset within file */
101 daddr_t f_bno; /* Starting block number */
102 off_t f_size; /* Size of file */
103 daddr_t f_buf_blkno; /* block number of data block */
104 char *f_buf; /* buffer for data block */
105 int f_susp_skip; /* len_skip for SUSP records */
106 };
107
108 struct ptable_ent {
109 char namlen [ISODCL( 1, 1)]; /* 711 */
110 char extlen [ISODCL( 2, 2)]; /* 711 */
111 char block [ISODCL( 3, 6)]; /* 732 */
112 char parent [ISODCL( 7, 8)]; /* 722 */
113 char name [1];
114 };
115 #define PTFIXSZ 8
116 #define PTSIZE(pp) roundup(PTFIXSZ + isonum_711((pp)->namlen), 2)
117
118 #define cdb2devb(bno) ((bno) * ISO_DEFAULT_BLOCK_SIZE / DEV_BSIZE)
119
120 static ISO_SUSP_HEADER *
susp_lookup_record(struct open_file * f,const char * identifier,struct iso_directory_record * dp,int lenskip)121 susp_lookup_record(struct open_file *f, const char *identifier,
122 struct iso_directory_record *dp, int lenskip)
123 {
124 static char susp_buffer[ISO_DEFAULT_BLOCK_SIZE];
125 ISO_SUSP_HEADER *sh;
126 ISO_RRIP_CONT *shc;
127 char *p, *end;
128 int error;
129 size_t read;
130
131 p = dp->name + isonum_711(dp->name_len) + lenskip;
132 /* Names of even length have a padding byte after the name. */
133 if ((isonum_711(dp->name_len) & 1) == 0)
134 p++;
135 end = (char *)dp + isonum_711(dp->length);
136 while (p + 3 < end) {
137 sh = (ISO_SUSP_HEADER *)p;
138 if (bcmp(sh->type, identifier, 2) == 0)
139 return (sh);
140 if (bcmp(sh->type, SUSP_STOP, 2) == 0)
141 return (NULL);
142 if (bcmp(sh->type, SUSP_CONTINUATION, 2) == 0) {
143 shc = (ISO_RRIP_CONT *)sh;
144 error = f->f_dev->dv_strategy(f->f_devdata, F_READ,
145 cdb2devb(isonum_733(shc->location)),
146 ISO_DEFAULT_BLOCK_SIZE, susp_buffer, &read);
147
148 /* Bail if it fails. */
149 if (error != 0 || read != ISO_DEFAULT_BLOCK_SIZE)
150 return (NULL);
151 p = susp_buffer + isonum_733(shc->offset);
152 end = p + isonum_733(shc->length);
153 } else {
154 /* Ignore this record and skip to the next. */
155 p += isonum_711(sh->length);
156
157 /* Avoid infinite loops with corrupted file systems */
158 if (isonum_711(sh->length) == 0)
159 return (NULL);
160 }
161 }
162 return (NULL);
163 }
164
165 static char *
rrip_lookup_name(struct open_file * f,struct iso_directory_record * dp,int lenskip,size_t * len)166 rrip_lookup_name(struct open_file *f, struct iso_directory_record *dp,
167 int lenskip, size_t *len)
168 {
169 ISO_RRIP_ALTNAME *p;
170
171 if (len == NULL)
172 return (NULL);
173
174 p = (ISO_RRIP_ALTNAME *)susp_lookup_record(f, RRIP_NAME, dp, lenskip);
175 if (p == NULL)
176 return (NULL);
177 switch (*p->flags) {
178 case ISO_SUSP_CFLAG_CURRENT:
179 *len = 1;
180 return (".");
181 case ISO_SUSP_CFLAG_PARENT:
182 *len = 2;
183 return ("..");
184 case 0:
185 *len = isonum_711(p->h.length) - 5;
186 return ((char *)p + 5);
187 default:
188 /*
189 * We don't handle hostnames or continued names as they are
190 * too hard, so just bail and use the default name.
191 */
192 return (NULL);
193 }
194 }
195
196 static int
rrip_check(struct open_file * f,struct iso_directory_record * dp,int * lenskip)197 rrip_check(struct open_file *f, struct iso_directory_record *dp, int *lenskip)
198 {
199 ISO_SUSP_PRESENT *sp;
200 ISO_RRIP_EXTREF *er;
201 char *p;
202
203 /* First, see if we can find a SP field. */
204 p = dp->name + isonum_711(dp->name_len);
205 if (p > (char *)dp + isonum_711(dp->length))
206 return (0);
207 sp = (ISO_SUSP_PRESENT *)p;
208 if (bcmp(sp->h.type, SUSP_PRESENT, 2) != 0)
209 return (0);
210 if (isonum_711(sp->h.length) != sizeof(ISO_SUSP_PRESENT))
211 return (0);
212 if (sp->signature[0] != 0xbe || sp->signature[1] != 0xef)
213 return (0);
214 *lenskip = isonum_711(sp->len_skp);
215
216 /*
217 * Now look for an ER field. If RRIP is present, then there must
218 * be at least one of these. It would be more pedantic to walk
219 * through the list of fields looking for a Rock Ridge ER field.
220 */
221 er = (ISO_RRIP_EXTREF *)susp_lookup_record(f, SUSP_EXTREF, dp, 0);
222 if (er == NULL)
223 return (0);
224 return (1);
225 }
226
227 static int
dirmatch(struct open_file * f,const char * path,struct iso_directory_record * dp,int use_rrip,int lenskip)228 dirmatch(struct open_file *f, const char *path, struct iso_directory_record *dp,
229 int use_rrip, int lenskip)
230 {
231 size_t len, plen;
232 char *cp, *sep;
233 int i, icase;
234
235 if (use_rrip)
236 cp = rrip_lookup_name(f, dp, lenskip, &len);
237 else
238 cp = NULL;
239 if (cp == NULL) {
240 len = isonum_711(dp->name_len);
241 cp = dp->name;
242 icase = 1;
243 } else
244 icase = 0;
245
246 sep = strchr(path, '/');
247 if (sep != NULL) {
248 plen = sep - path;
249 } else {
250 plen = strlen(path);
251 }
252
253 if (plen != len)
254 return (0);
255
256 for (i = len; --i >= 0; path++, cp++) {
257 if (!*path || *path == '/')
258 break;
259 if (*path == *cp)
260 continue;
261 if (!icase && toupper(*path) == *cp)
262 continue;
263 return 0;
264 }
265 if (*path && *path != '/')
266 return 0;
267 /*
268 * Allow stripping of trailing dots and the version number.
269 * Note that this will find the first instead of the last version
270 * of a file.
271 */
272 if (i >= 0 && (*cp == ';' || *cp == '.')) {
273 /* This is to prevent matching of numeric extensions */
274 if (*cp == '.' && cp[1] != ';')
275 return 0;
276 while (--i >= 0)
277 if (*++cp != ';' && (*cp < '0' || *cp > '9'))
278 return 0;
279 }
280 return 1;
281 }
282
283 static int
cd9660_open(const char * path,struct open_file * f)284 cd9660_open(const char *path, struct open_file *f)
285 {
286 struct file *fp = NULL;
287 void *buf;
288 struct iso_primary_descriptor *vd;
289 size_t buf_size, read, dsize, off;
290 daddr_t bno, boff;
291 struct iso_directory_record rec;
292 struct iso_directory_record *dp = NULL;
293 int rc, first, use_rrip, lenskip;
294 bool isdir = false;
295
296 /* First find the volume descriptor */
297 buf = malloc(buf_size = ISO_DEFAULT_BLOCK_SIZE);
298 vd = buf;
299 for (bno = 16;; bno++) {
300 twiddle(1);
301 rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno),
302 ISO_DEFAULT_BLOCK_SIZE, buf, &read);
303 if (rc)
304 goto out;
305 if (read != ISO_DEFAULT_BLOCK_SIZE) {
306 rc = EIO;
307 goto out;
308 }
309 rc = EINVAL;
310 if (bcmp(vd->id, ISO_STANDARD_ID, sizeof vd->id) != 0)
311 goto out;
312 if (isonum_711(vd->type) == ISO_VD_END)
313 goto out;
314 if (isonum_711(vd->type) == ISO_VD_PRIMARY)
315 break;
316 }
317 if (isonum_723(vd->logical_block_size) != ISO_DEFAULT_BLOCK_SIZE)
318 goto out;
319
320 bcopy(vd->root_directory_record, &rec, sizeof(rec));
321 if (*path == '/') path++; /* eat leading '/' */
322
323 first = 1;
324 use_rrip = 0;
325 lenskip = 0;
326 while (*path) {
327 bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length);
328 dsize = isonum_733(rec.size);
329 off = 0;
330 boff = 0;
331
332 while (off < dsize) {
333 if ((off % ISO_DEFAULT_BLOCK_SIZE) == 0) {
334 twiddle(1);
335 rc = f->f_dev->dv_strategy
336 (f->f_devdata, F_READ,
337 cdb2devb(bno + boff),
338 ISO_DEFAULT_BLOCK_SIZE,
339 buf, &read);
340 if (rc)
341 goto out;
342 if (read != ISO_DEFAULT_BLOCK_SIZE) {
343 rc = EIO;
344 goto out;
345 }
346 boff++;
347 dp = (struct iso_directory_record *) buf;
348 }
349 if (isonum_711(dp->length) == 0) {
350 /* skip to next block, if any */
351 off = boff * ISO_DEFAULT_BLOCK_SIZE;
352 continue;
353 }
354
355 /* See if RRIP is in use. */
356 if (first)
357 use_rrip = rrip_check(f, dp, &lenskip);
358
359 if (dirmatch(f, path, dp, use_rrip,
360 first ? 0 : lenskip)) {
361 first = 0;
362 break;
363 } else
364 first = 0;
365
366 dp = (struct iso_directory_record *)
367 ((char *) dp + isonum_711(dp->length));
368 /* If the new block has zero length, it is padding. */
369 if (isonum_711(dp->length) == 0) {
370 /* Skip to next block, if any. */
371 off = boff * ISO_DEFAULT_BLOCK_SIZE;
372 continue;
373 }
374 off += isonum_711(dp->length);
375 }
376 if (off >= dsize) {
377 rc = ENOENT;
378 goto out;
379 }
380
381 rec = *dp;
382 while (*path && *path != '/') /* look for next component */
383 path++;
384
385 if (*path) /* this component was directory */
386 isdir = true;
387
388 while (*path == '/')
389 path++; /* skip '/' */
390
391 if (*path) /* We do have next component. */
392 isdir = false;
393 }
394
395 /*
396 * if the path had trailing / but the path does point to file,
397 * report the error ENOTDIR.
398 */
399 if (isdir == true && (isonum_711(rec.flags) & 2) == 0) {
400 rc = ENOTDIR;
401 goto out;
402 }
403
404 /* allocate file system specific data structure */
405 fp = malloc(sizeof(struct file));
406 bzero(fp, sizeof(struct file));
407 f->f_fsdata = (void *)fp;
408
409 if ((isonum_711(rec.flags) & 2) != 0) {
410 fp->f_flags = F_ISDIR;
411 }
412 if (first) {
413 fp->f_flags |= F_ROOTDIR;
414
415 /* Check for Rock Ridge since we didn't in the loop above. */
416 bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length);
417 twiddle(1);
418 rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno),
419 ISO_DEFAULT_BLOCK_SIZE, buf, &read);
420 if (rc)
421 goto out;
422 if (read != ISO_DEFAULT_BLOCK_SIZE) {
423 rc = EIO;
424 goto out;
425 }
426 dp = (struct iso_directory_record *)buf;
427 use_rrip = rrip_check(f, dp, &lenskip);
428 }
429 if (use_rrip) {
430 fp->f_flags |= F_RR;
431 fp->f_susp_skip = lenskip;
432 }
433 fp->f_off = 0;
434 fp->f_bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length);
435 fp->f_size = isonum_733(rec.size);
436 free(buf);
437
438 return 0;
439
440 out:
441 if (fp)
442 free(fp);
443 free(buf);
444
445 return rc;
446 }
447
448 static int
cd9660_close(struct open_file * f)449 cd9660_close(struct open_file *f)
450 {
451 struct file *fp = (struct file *)f->f_fsdata;
452
453 f->f_fsdata = NULL;
454 free(fp);
455
456 return 0;
457 }
458
459 static int
buf_read_file(struct open_file * f,char ** buf_p,size_t * size_p)460 buf_read_file(struct open_file *f, char **buf_p, size_t *size_p)
461 {
462 struct file *fp = (struct file *)f->f_fsdata;
463 daddr_t blkno, blkoff;
464 int rc = 0;
465 size_t read;
466
467 blkno = fp->f_off / ISO_DEFAULT_BLOCK_SIZE + fp->f_bno;
468 blkoff = fp->f_off % ISO_DEFAULT_BLOCK_SIZE;
469
470 if (blkno != fp->f_buf_blkno) {
471 if (fp->f_buf == (char *)0)
472 fp->f_buf = malloc(ISO_DEFAULT_BLOCK_SIZE);
473
474 twiddle(16);
475 rc = f->f_dev->dv_strategy(f->f_devdata, F_READ,
476 cdb2devb(blkno), ISO_DEFAULT_BLOCK_SIZE,
477 fp->f_buf, &read);
478 if (rc)
479 return (rc);
480 if (read != ISO_DEFAULT_BLOCK_SIZE)
481 return (EIO);
482
483 fp->f_buf_blkno = blkno;
484 }
485
486 *buf_p = fp->f_buf + blkoff;
487 *size_p = ISO_DEFAULT_BLOCK_SIZE - blkoff;
488
489 if (*size_p > fp->f_size - fp->f_off)
490 *size_p = fp->f_size - fp->f_off;
491 return (rc);
492 }
493
494 static int
cd9660_read(struct open_file * f,void * start,size_t size,size_t * resid)495 cd9660_read(struct open_file *f, void *start, size_t size, size_t *resid)
496 {
497 struct file *fp = (struct file *)f->f_fsdata;
498 char *buf, *addr;
499 size_t buf_size, csize;
500 int rc = 0;
501
502 addr = start;
503 while (size) {
504 if (fp->f_off < 0 || fp->f_off >= fp->f_size)
505 break;
506
507 rc = buf_read_file(f, &buf, &buf_size);
508 if (rc)
509 break;
510
511 csize = size > buf_size ? buf_size : size;
512 bcopy(buf, addr, csize);
513
514 fp->f_off += csize;
515 addr += csize;
516 size -= csize;
517 }
518 if (resid)
519 *resid = size;
520 return (rc);
521 }
522
523 static int
cd9660_readdir(struct open_file * f,struct dirent * d)524 cd9660_readdir(struct open_file *f, struct dirent *d)
525 {
526 struct file *fp = (struct file *)f->f_fsdata;
527 struct iso_directory_record *ep;
528 size_t buf_size, reclen, namelen;
529 int error = 0;
530 int lenskip;
531 char *buf, *name;
532
533 again:
534 if (fp->f_off >= fp->f_size)
535 return (ENOENT);
536 error = buf_read_file(f, &buf, &buf_size);
537 if (error)
538 return (error);
539 ep = (struct iso_directory_record *)buf;
540
541 if (isonum_711(ep->length) == 0) {
542 daddr_t blkno;
543
544 /* skip to next block, if any */
545 blkno = fp->f_off / ISO_DEFAULT_BLOCK_SIZE;
546 fp->f_off = (blkno + 1) * ISO_DEFAULT_BLOCK_SIZE;
547 goto again;
548 }
549
550 if (fp->f_flags & F_RR) {
551 if (fp->f_flags & F_ROOTDIR && fp->f_off == 0)
552 lenskip = 0;
553 else
554 lenskip = fp->f_susp_skip;
555 name = rrip_lookup_name(f, ep, lenskip, &namelen);
556 } else
557 name = NULL;
558 if (name == NULL) {
559 namelen = isonum_711(ep->name_len);
560 name = ep->name;
561 if (namelen == 1) {
562 if (ep->name[0] == 0)
563 name = ".";
564 else if (ep->name[0] == 1) {
565 namelen = 2;
566 name = "..";
567 }
568 }
569 }
570 reclen = sizeof(struct dirent) - (MAXNAMLEN+1) + namelen + 1;
571 reclen = (reclen + 3) & ~3;
572
573 d->d_fileno = isonum_733(ep->extent);
574 d->d_reclen = reclen;
575 if (isonum_711(ep->flags) & 2)
576 d->d_type = DT_DIR;
577 else
578 d->d_type = DT_REG;
579 d->d_namlen = namelen;
580
581 bcopy(name, d->d_name, d->d_namlen);
582 d->d_name[d->d_namlen] = 0;
583
584 fp->f_off += isonum_711(ep->length);
585 return (0);
586 }
587
588 static off_t
cd9660_seek(struct open_file * f,off_t offset,int where)589 cd9660_seek(struct open_file *f, off_t offset, int where)
590 {
591 struct file *fp = (struct file *)f->f_fsdata;
592
593 switch (where) {
594 case SEEK_SET:
595 fp->f_off = offset;
596 break;
597 case SEEK_CUR:
598 fp->f_off += offset;
599 break;
600 case SEEK_END:
601 fp->f_off = fp->f_size - offset;
602 break;
603 default:
604 return -1;
605 }
606 return fp->f_off;
607 }
608
609 static int
cd9660_stat(struct open_file * f,struct stat * sb)610 cd9660_stat(struct open_file *f, struct stat *sb)
611 {
612 struct file *fp = (struct file *)f->f_fsdata;
613
614 /* only important stuff */
615 sb->st_mode = S_IRUSR | S_IRGRP | S_IROTH;
616 if (fp->f_flags & F_ISDIR)
617 sb->st_mode |= S_IFDIR;
618 else
619 sb->st_mode |= S_IFREG;
620 sb->st_uid = sb->st_gid = 0;
621 sb->st_size = fp->f_size;
622 return 0;
623 }
624