cd9660.c revision 267654
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: releng/9.3/lib/libstand/cd9660.c 221358 2011-05-03 04:44:50Z rodrigc $"); 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 <sys/dirent.h> 46#include <isofs/cd9660/iso.h> 47#include <isofs/cd9660/cd9660_rrip.h> 48 49#include "stand.h" 50 51#define SUSP_CONTINUATION "CE" 52#define SUSP_PRESENT "SP" 53#define SUSP_STOP "ST" 54#define SUSP_EXTREF "ER" 55#define RRIP_NAME "NM" 56 57typedef struct { 58 ISO_SUSP_HEADER h; 59 u_char signature [ISODCL ( 5, 6)]; 60 u_char len_skp [ISODCL ( 7, 7)]; /* 711 */ 61} ISO_SUSP_PRESENT; 62 63static int buf_read_file(struct open_file *f, char **buf_p, 64 size_t *size_p); 65static int cd9660_open(const char *path, struct open_file *f); 66static int cd9660_close(struct open_file *f); 67static int cd9660_read(struct open_file *f, void *buf, size_t size, 68 size_t *resid); 69static int cd9660_write(struct open_file *f, void *buf, size_t size, 70 size_t *resid); 71static off_t cd9660_seek(struct open_file *f, off_t offset, int where); 72static int cd9660_stat(struct open_file *f, struct stat *sb); 73static int cd9660_readdir(struct open_file *f, struct dirent *d); 74static int dirmatch(struct open_file *f, const char *path, 75 struct iso_directory_record *dp, int use_rrip, int lenskip); 76static int rrip_check(struct open_file *f, struct iso_directory_record *dp, 77 int *lenskip); 78static char *rrip_lookup_name(struct open_file *f, 79 struct iso_directory_record *dp, int lenskip, size_t *len); 80static ISO_SUSP_HEADER *susp_lookup_record(struct open_file *f, 81 const char *identifier, struct iso_directory_record *dp, 82 int lenskip); 83 84struct fs_ops cd9660_fsops = { 85 "cd9660", 86 cd9660_open, 87 cd9660_close, 88 cd9660_read, 89 cd9660_write, 90 cd9660_seek, 91 cd9660_stat, 92 cd9660_readdir 93}; 94 95#define F_ISDIR 0x0001 /* Directory */ 96#define F_ROOTDIR 0x0002 /* Root directory */ 97#define F_RR 0x0004 /* Rock Ridge on this volume */ 98 99struct file { 100 int f_flags; /* file flags */ 101 off_t f_off; /* Current offset within file */ 102 daddr_t f_bno; /* Starting block number */ 103 off_t f_size; /* Size of file */ 104 daddr_t f_buf_blkno; /* block number of data block */ 105 char *f_buf; /* buffer for data block */ 106 int f_susp_skip; /* len_skip for SUSP records */ 107}; 108 109struct ptable_ent { 110 char namlen [ISODCL( 1, 1)]; /* 711 */ 111 char extlen [ISODCL( 2, 2)]; /* 711 */ 112 char block [ISODCL( 3, 6)]; /* 732 */ 113 char parent [ISODCL( 7, 8)]; /* 722 */ 114 char name [1]; 115}; 116#define PTFIXSZ 8 117#define PTSIZE(pp) roundup(PTFIXSZ + isonum_711((pp)->namlen), 2) 118 119#define cdb2devb(bno) ((bno) * ISO_DEFAULT_BLOCK_SIZE / DEV_BSIZE) 120 121static ISO_SUSP_HEADER * 122susp_lookup_record(struct open_file *f, const char *identifier, 123 struct iso_directory_record *dp, int lenskip) 124{ 125 static char susp_buffer[ISO_DEFAULT_BLOCK_SIZE]; 126 ISO_SUSP_HEADER *sh; 127 ISO_RRIP_CONT *shc; 128 char *p, *end; 129 int error; 130 size_t read; 131 132 p = dp->name + isonum_711(dp->name_len) + lenskip; 133 /* Names of even length have a padding byte after the name. */ 134 if ((isonum_711(dp->name_len) & 1) == 0) 135 p++; 136 end = (char *)dp + isonum_711(dp->length); 137 while (p + 3 < end) { 138 sh = (ISO_SUSP_HEADER *)p; 139 if (bcmp(sh->type, identifier, 2) == 0) 140 return (sh); 141 if (bcmp(sh->type, SUSP_STOP, 2) == 0) 142 return (NULL); 143 if (bcmp(sh->type, SUSP_CONTINUATION, 2) == 0) { 144 shc = (ISO_RRIP_CONT *)sh; 145 error = f->f_dev->dv_strategy(f->f_devdata, F_READ, 146 cdb2devb(isonum_733(shc->location)), 147 ISO_DEFAULT_BLOCK_SIZE, susp_buffer, &read); 148 149 /* Bail if it fails. */ 150 if (error != 0 || read != ISO_DEFAULT_BLOCK_SIZE) 151 return (NULL); 152 p = susp_buffer + isonum_733(shc->offset); 153 end = p + isonum_733(shc->length); 154 } else 155 /* Ignore this record and skip to the next. */ 156 p += isonum_711(sh->length); 157 } 158 return (NULL); 159} 160 161static char * 162rrip_lookup_name(struct open_file *f, struct iso_directory_record *dp, 163 int lenskip, size_t *len) 164{ 165 ISO_RRIP_ALTNAME *p; 166 167 if (len == NULL) 168 return (NULL); 169 170 p = (ISO_RRIP_ALTNAME *)susp_lookup_record(f, RRIP_NAME, dp, lenskip); 171 if (p == NULL) 172 return (NULL); 173 switch (*p->flags) { 174 case ISO_SUSP_CFLAG_CURRENT: 175 *len = 1; 176 return ("."); 177 case ISO_SUSP_CFLAG_PARENT: 178 *len = 2; 179 return (".."); 180 case 0: 181 *len = isonum_711(p->h.length) - 5; 182 return ((char *)p + 5); 183 default: 184 /* 185 * We don't handle hostnames or continued names as they are 186 * too hard, so just bail and use the default name. 187 */ 188 return (NULL); 189 } 190} 191 192static int 193rrip_check(struct open_file *f, struct iso_directory_record *dp, int *lenskip) 194{ 195 ISO_SUSP_PRESENT *sp; 196 ISO_RRIP_EXTREF *er; 197 char *p; 198 199 /* First, see if we can find a SP field. */ 200 p = dp->name + isonum_711(dp->name_len); 201 if (p > (char *)dp + isonum_711(dp->length)) 202 return (0); 203 sp = (ISO_SUSP_PRESENT *)p; 204 if (bcmp(sp->h.type, SUSP_PRESENT, 2) != 0) 205 return (0); 206 if (isonum_711(sp->h.length) != sizeof(ISO_SUSP_PRESENT)) 207 return (0); 208 if (sp->signature[0] != 0xbe || sp->signature[1] != 0xef) 209 return (0); 210 *lenskip = isonum_711(sp->len_skp); 211 212 /* 213 * Now look for an ER field. If RRIP is present, then there must 214 * be at least one of these. It would be more pedantic to walk 215 * through the list of fields looking for a Rock Ridge ER field. 216 */ 217 er = (ISO_RRIP_EXTREF *)susp_lookup_record(f, SUSP_EXTREF, dp, 0); 218 if (er == NULL) 219 return (0); 220 return (1); 221} 222 223static int 224dirmatch(struct open_file *f, const char *path, struct iso_directory_record *dp, 225 int use_rrip, int lenskip) 226{ 227 size_t len; 228 char *cp; 229 int i, icase; 230 231 if (use_rrip) 232 cp = rrip_lookup_name(f, dp, lenskip, &len); 233 else 234 cp = NULL; 235 if (cp == NULL) { 236 len = isonum_711(dp->name_len); 237 cp = dp->name; 238 icase = 1; 239 } else 240 icase = 0; 241 for (i = len; --i >= 0; path++, cp++) { 242 if (!*path || *path == '/') 243 break; 244 if (*path == *cp) 245 continue; 246 if (!icase && toupper(*path) == *cp) 247 continue; 248 return 0; 249 } 250 if (*path && *path != '/') 251 return 0; 252 /* 253 * Allow stripping of trailing dots and the version number. 254 * Note that this will find the first instead of the last version 255 * of a file. 256 */ 257 if (i >= 0 && (*cp == ';' || *cp == '.')) { 258 /* This is to prevent matching of numeric extensions */ 259 if (*cp == '.' && cp[1] != ';') 260 return 0; 261 while (--i >= 0) 262 if (*++cp != ';' && (*cp < '0' || *cp > '9')) 263 return 0; 264 } 265 return 1; 266} 267 268static int 269cd9660_open(const char *path, struct open_file *f) 270{ 271 struct file *fp = 0; 272 void *buf; 273 struct iso_primary_descriptor *vd; 274 size_t buf_size, read, dsize, off; 275 daddr_t bno, boff; 276 struct iso_directory_record rec; 277 struct iso_directory_record *dp = 0; 278 int rc, first, use_rrip, lenskip; 279 280 /* First find the volume descriptor */ 281 buf = malloc(buf_size = ISO_DEFAULT_BLOCK_SIZE); 282 vd = buf; 283 for (bno = 16;; bno++) { 284 twiddle(); 285 rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno), 286 ISO_DEFAULT_BLOCK_SIZE, buf, &read); 287 if (rc) 288 goto out; 289 if (read != ISO_DEFAULT_BLOCK_SIZE) { 290 rc = EIO; 291 goto out; 292 } 293 rc = EINVAL; 294 if (bcmp(vd->id, ISO_STANDARD_ID, sizeof vd->id) != 0) 295 goto out; 296 if (isonum_711(vd->type) == ISO_VD_END) 297 goto out; 298 if (isonum_711(vd->type) == ISO_VD_PRIMARY) 299 break; 300 } 301 if (isonum_723(vd->logical_block_size) != ISO_DEFAULT_BLOCK_SIZE) 302 goto out; 303 304 rec = *(struct iso_directory_record *) vd->root_directory_record; 305 if (*path == '/') path++; /* eat leading '/' */ 306 307 first = 1; 308 use_rrip = 0; 309 while (*path) { 310 bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length); 311 dsize = isonum_733(rec.size); 312 off = 0; 313 boff = 0; 314 315 while (off < dsize) { 316 if ((off % ISO_DEFAULT_BLOCK_SIZE) == 0) { 317 twiddle(); 318 rc = f->f_dev->dv_strategy 319 (f->f_devdata, F_READ, 320 cdb2devb(bno + boff), 321 ISO_DEFAULT_BLOCK_SIZE, 322 buf, &read); 323 if (rc) 324 goto out; 325 if (read != ISO_DEFAULT_BLOCK_SIZE) { 326 rc = EIO; 327 goto out; 328 } 329 boff++; 330 dp = (struct iso_directory_record *) buf; 331 } 332 if (isonum_711(dp->length) == 0) { 333 /* skip to next block, if any */ 334 off = boff * ISO_DEFAULT_BLOCK_SIZE; 335 continue; 336 } 337 338 /* See if RRIP is in use. */ 339 if (first) 340 use_rrip = rrip_check(f, dp, &lenskip); 341 342 if (dirmatch(f, path, dp, use_rrip, 343 first ? 0 : lenskip)) { 344 first = 0; 345 break; 346 } else 347 first = 0; 348 349 dp = (struct iso_directory_record *) 350 ((char *) dp + isonum_711(dp->length)); 351 off += isonum_711(dp->length); 352 } 353 if (off >= dsize) { 354 rc = ENOENT; 355 goto out; 356 } 357 358 rec = *dp; 359 while (*path && *path != '/') /* look for next component */ 360 path++; 361 if (*path) path++; /* skip '/' */ 362 } 363 364 /* allocate file system specific data structure */ 365 fp = malloc(sizeof(struct file)); 366 bzero(fp, sizeof(struct file)); 367 f->f_fsdata = (void *)fp; 368 369 if ((isonum_711(rec.flags) & 2) != 0) { 370 fp->f_flags = F_ISDIR; 371 } 372 if (first) { 373 fp->f_flags |= F_ROOTDIR; 374 375 /* Check for Rock Ridge since we didn't in the loop above. */ 376 bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length); 377 twiddle(); 378 rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno), 379 ISO_DEFAULT_BLOCK_SIZE, buf, &read); 380 if (rc) 381 goto out; 382 if (read != ISO_DEFAULT_BLOCK_SIZE) { 383 rc = EIO; 384 goto out; 385 } 386 dp = (struct iso_directory_record *)buf; 387 use_rrip = rrip_check(f, dp, &lenskip); 388 } 389 if (use_rrip) { 390 fp->f_flags |= F_RR; 391 fp->f_susp_skip = lenskip; 392 } 393 fp->f_off = 0; 394 fp->f_bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length); 395 fp->f_size = isonum_733(rec.size); 396 free(buf); 397 398 return 0; 399 400out: 401 if (fp) 402 free(fp); 403 free(buf); 404 405 return rc; 406} 407 408static int 409cd9660_close(struct open_file *f) 410{ 411 struct file *fp = (struct file *)f->f_fsdata; 412 413 f->f_fsdata = 0; 414 free(fp); 415 416 return 0; 417} 418 419static int 420buf_read_file(struct open_file *f, char **buf_p, size_t *size_p) 421{ 422 struct file *fp = (struct file *)f->f_fsdata; 423 daddr_t blkno, blkoff; 424 int rc = 0; 425 size_t read; 426 427 blkno = fp->f_off / ISO_DEFAULT_BLOCK_SIZE + fp->f_bno; 428 blkoff = fp->f_off % ISO_DEFAULT_BLOCK_SIZE; 429 430 if (blkno != fp->f_buf_blkno) { 431 if (fp->f_buf == (char *)0) 432 fp->f_buf = malloc(ISO_DEFAULT_BLOCK_SIZE); 433 434 twiddle(); 435 rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, 436 cdb2devb(blkno), ISO_DEFAULT_BLOCK_SIZE, fp->f_buf, &read); 437 if (rc) 438 return (rc); 439 if (read != ISO_DEFAULT_BLOCK_SIZE) 440 return (EIO); 441 442 fp->f_buf_blkno = blkno; 443 } 444 445 *buf_p = fp->f_buf + blkoff; 446 *size_p = ISO_DEFAULT_BLOCK_SIZE - blkoff; 447 448 if (*size_p > fp->f_size - fp->f_off) 449 *size_p = fp->f_size - fp->f_off; 450 return (rc); 451} 452 453static int 454cd9660_read(struct open_file *f, void *start, size_t size, size_t *resid) 455{ 456 struct file *fp = (struct file *)f->f_fsdata; 457 char *buf, *addr; 458 size_t buf_size, csize; 459 int rc = 0; 460 461 addr = start; 462 while (size) { 463 if (fp->f_off < 0 || fp->f_off >= fp->f_size) 464 break; 465 466 rc = buf_read_file(f, &buf, &buf_size); 467 if (rc) 468 break; 469 470 csize = size > buf_size ? buf_size : size; 471 bcopy(buf, addr, csize); 472 473 fp->f_off += csize; 474 addr += csize; 475 size -= csize; 476 } 477 if (resid) 478 *resid = size; 479 return (rc); 480} 481 482static int 483cd9660_readdir(struct open_file *f, struct dirent *d) 484{ 485 struct file *fp = (struct file *)f->f_fsdata; 486 struct iso_directory_record *ep; 487 size_t buf_size, reclen, namelen; 488 int error = 0; 489 int lenskip; 490 char *buf, *name; 491 492again: 493 if (fp->f_off >= fp->f_size) 494 return (ENOENT); 495 error = buf_read_file(f, &buf, &buf_size); 496 if (error) 497 return (error); 498 ep = (struct iso_directory_record *)buf; 499 500 if (isonum_711(ep->length) == 0) { 501 daddr_t blkno; 502 503 /* skip to next block, if any */ 504 blkno = fp->f_off / ISO_DEFAULT_BLOCK_SIZE; 505 fp->f_off = (blkno + 1) * ISO_DEFAULT_BLOCK_SIZE; 506 goto again; 507 } 508 509 if (fp->f_flags & F_RR) { 510 if (fp->f_flags & F_ROOTDIR && fp->f_off == 0) 511 lenskip = 0; 512 else 513 lenskip = fp->f_susp_skip; 514 name = rrip_lookup_name(f, ep, lenskip, &namelen); 515 } else 516 name = NULL; 517 if (name == NULL) { 518 namelen = isonum_711(ep->name_len); 519 name = ep->name; 520 if (namelen == 1) { 521 if (ep->name[0] == 0) 522 name = "."; 523 else if (ep->name[0] == 1) { 524 namelen = 2; 525 name = ".."; 526 } 527 } 528 } 529 reclen = sizeof(struct dirent) - (MAXNAMLEN+1) + namelen + 1; 530 reclen = (reclen + 3) & ~3; 531 532 d->d_fileno = isonum_733(ep->extent); 533 d->d_reclen = reclen; 534 if (isonum_711(ep->flags) & 2) 535 d->d_type = DT_DIR; 536 else 537 d->d_type = DT_REG; 538 d->d_namlen = namelen; 539 540 bcopy(name, d->d_name, d->d_namlen); 541 d->d_name[d->d_namlen] = 0; 542 543 fp->f_off += isonum_711(ep->length); 544 return (0); 545} 546 547static int 548cd9660_write(struct open_file *f __unused, void *start __unused, size_t size __unused, size_t *resid __unused) 549{ 550 return EROFS; 551} 552 553static off_t 554cd9660_seek(struct open_file *f, off_t offset, int where) 555{ 556 struct file *fp = (struct file *)f->f_fsdata; 557 558 switch (where) { 559 case SEEK_SET: 560 fp->f_off = offset; 561 break; 562 case SEEK_CUR: 563 fp->f_off += offset; 564 break; 565 case SEEK_END: 566 fp->f_off = fp->f_size - offset; 567 break; 568 default: 569 return -1; 570 } 571 return fp->f_off; 572} 573 574static int 575cd9660_stat(struct open_file *f, struct stat *sb) 576{ 577 struct file *fp = (struct file *)f->f_fsdata; 578 579 /* only important stuff */ 580 sb->st_mode = S_IRUSR | S_IRGRP | S_IROTH; 581 if (fp->f_flags & F_ISDIR) 582 sb->st_mode |= S_IFDIR; 583 else 584 sb->st_mode |= S_IFREG; 585 sb->st_uid = sb->st_gid = 0; 586 sb->st_size = fp->f_size; 587 return 0; 588} 589