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 <sys/dirent.h> 46 #include <fs/cd9660/iso.h> 47 #include <fs/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 57 typedef 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 63 static int buf_read_file(struct open_file *f, char **buf_p, 64 size_t *size_p); 65 static int cd9660_open(const char *path, struct open_file *f); 66 static int cd9660_close(struct open_file *f); 67 static int cd9660_read(struct open_file *f, void *buf, size_t size, 68 size_t *resid); 69 static off_t cd9660_seek(struct open_file *f, off_t offset, int where); 70 static int cd9660_stat(struct open_file *f, struct stat *sb); 71 static int cd9660_readdir(struct open_file *f, struct dirent *d); 72 static int dirmatch(struct open_file *f, const char *path, 73 struct iso_directory_record *dp, int use_rrip, int lenskip); 74 static int rrip_check(struct open_file *f, struct iso_directory_record *dp, 75 int *lenskip); 76 static char *rrip_lookup_name(struct open_file *f, 77 struct iso_directory_record *dp, int lenskip, size_t *len); 78 static ISO_SUSP_HEADER *susp_lookup_record(struct open_file *f, 79 const char *identifier, struct iso_directory_record *dp, 80 int lenskip); 81 82 struct fs_ops cd9660_fsops = { 83 "cd9660", 84 cd9660_open, 85 cd9660_close, 86 cd9660_read, 87 null_write, 88 cd9660_seek, 89 cd9660_stat, 90 cd9660_readdir 91 }; 92 93 #define F_ISDIR 0x0001 /* Directory */ 94 #define F_ROOTDIR 0x0002 /* Root directory */ 95 #define F_RR 0x0004 /* Rock Ridge on this volume */ 96 97 struct file { 98 int f_flags; /* file flags */ 99 off_t f_off; /* Current offset within file */ 100 daddr_t f_bno; /* Starting block number */ 101 off_t f_size; /* Size of file */ 102 daddr_t f_buf_blkno; /* block number of data block */ 103 char *f_buf; /* buffer for data block */ 104 int f_susp_skip; /* len_skip for SUSP records */ 105 }; 106 107 struct ptable_ent { 108 char namlen [ISODCL( 1, 1)]; /* 711 */ 109 char extlen [ISODCL( 2, 2)]; /* 711 */ 110 char block [ISODCL( 3, 6)]; /* 732 */ 111 char parent [ISODCL( 7, 8)]; /* 722 */ 112 char name [1]; 113 }; 114 #define PTFIXSZ 8 115 #define PTSIZE(pp) roundup(PTFIXSZ + isonum_711((pp)->namlen), 2) 116 117 #define cdb2devb(bno) ((bno) * ISO_DEFAULT_BLOCK_SIZE / DEV_BSIZE) 118 119 static ISO_SUSP_HEADER * 120 susp_lookup_record(struct open_file *f, const char *identifier, 121 struct iso_directory_record *dp, int lenskip) 122 { 123 static char susp_buffer[ISO_DEFAULT_BLOCK_SIZE]; 124 ISO_SUSP_HEADER *sh; 125 ISO_RRIP_CONT *shc; 126 char *p, *end; 127 int error; 128 size_t read; 129 130 p = dp->name + isonum_711(dp->name_len) + lenskip; 131 /* Names of even length have a padding byte after the name. */ 132 if ((isonum_711(dp->name_len) & 1) == 0) 133 p++; 134 end = (char *)dp + isonum_711(dp->length); 135 while (p + 3 < end) { 136 sh = (ISO_SUSP_HEADER *)p; 137 if (bcmp(sh->type, identifier, 2) == 0) 138 return (sh); 139 if (bcmp(sh->type, SUSP_STOP, 2) == 0) 140 return (NULL); 141 if (bcmp(sh->type, SUSP_CONTINUATION, 2) == 0) { 142 shc = (ISO_RRIP_CONT *)sh; 143 error = f->f_dev->dv_strategy(f->f_devdata, F_READ, 144 cdb2devb(isonum_733(shc->location)), 145 ISO_DEFAULT_BLOCK_SIZE, susp_buffer, &read); 146 147 /* Bail if it fails. */ 148 if (error != 0 || read != ISO_DEFAULT_BLOCK_SIZE) 149 return (NULL); 150 p = susp_buffer + isonum_733(shc->offset); 151 end = p + isonum_733(shc->length); 152 } else { 153 /* Ignore this record and skip to the next. */ 154 p += isonum_711(sh->length); 155 156 /* Avoid infinite loops with corrupted file systems */ 157 if (isonum_711(sh->length) == 0) 158 return (NULL); 159 } 160 } 161 return (NULL); 162 } 163 164 static char * 165 rrip_lookup_name(struct open_file *f, struct iso_directory_record *dp, 166 int lenskip, size_t *len) 167 { 168 ISO_RRIP_ALTNAME *p; 169 170 if (len == NULL) 171 return (NULL); 172 173 p = (ISO_RRIP_ALTNAME *)susp_lookup_record(f, RRIP_NAME, dp, lenskip); 174 if (p == NULL) 175 return (NULL); 176 switch (*p->flags) { 177 case ISO_SUSP_CFLAG_CURRENT: 178 *len = 1; 179 return ("."); 180 case ISO_SUSP_CFLAG_PARENT: 181 *len = 2; 182 return (".."); 183 case 0: 184 *len = isonum_711(p->h.length) - 5; 185 return ((char *)p + 5); 186 default: 187 /* 188 * We don't handle hostnames or continued names as they are 189 * too hard, so just bail and use the default name. 190 */ 191 return (NULL); 192 } 193 } 194 195 static int 196 rrip_check(struct open_file *f, struct iso_directory_record *dp, int *lenskip) 197 { 198 ISO_SUSP_PRESENT *sp; 199 ISO_RRIP_EXTREF *er; 200 char *p; 201 202 /* First, see if we can find a SP field. */ 203 p = dp->name + isonum_711(dp->name_len); 204 if (p > (char *)dp + isonum_711(dp->length)) 205 return (0); 206 sp = (ISO_SUSP_PRESENT *)p; 207 if (bcmp(sp->h.type, SUSP_PRESENT, 2) != 0) 208 return (0); 209 if (isonum_711(sp->h.length) != sizeof(ISO_SUSP_PRESENT)) 210 return (0); 211 if (sp->signature[0] != 0xbe || sp->signature[1] != 0xef) 212 return (0); 213 *lenskip = isonum_711(sp->len_skp); 214 215 /* 216 * Now look for an ER field. If RRIP is present, then there must 217 * be at least one of these. It would be more pedantic to walk 218 * through the list of fields looking for a Rock Ridge ER field. 219 */ 220 er = (ISO_RRIP_EXTREF *)susp_lookup_record(f, SUSP_EXTREF, dp, 0); 221 if (er == NULL) 222 return (0); 223 return (1); 224 } 225 226 static int 227 dirmatch(struct open_file *f, const char *path, struct iso_directory_record *dp, 228 int use_rrip, int lenskip) 229 { 230 size_t len; 231 char *cp; 232 int i, icase; 233 234 if (use_rrip) 235 cp = rrip_lookup_name(f, dp, lenskip, &len); 236 else 237 cp = NULL; 238 if (cp == NULL) { 239 len = isonum_711(dp->name_len); 240 cp = dp->name; 241 icase = 1; 242 } else 243 icase = 0; 244 245 if (strlen(path) != len) 246 return (0); 247 248 for (i = len; --i >= 0; path++, cp++) { 249 if (!*path || *path == '/') 250 break; 251 if (*path == *cp) 252 continue; 253 if (!icase && toupper(*path) == *cp) 254 continue; 255 return 0; 256 } 257 if (*path && *path != '/') 258 return 0; 259 /* 260 * Allow stripping of trailing dots and the version number. 261 * Note that this will find the first instead of the last version 262 * of a file. 263 */ 264 if (i >= 0 && (*cp == ';' || *cp == '.')) { 265 /* This is to prevent matching of numeric extensions */ 266 if (*cp == '.' && cp[1] != ';') 267 return 0; 268 while (--i >= 0) 269 if (*++cp != ';' && (*cp < '0' || *cp > '9')) 270 return 0; 271 } 272 return 1; 273 } 274 275 static int 276 cd9660_open(const char *path, struct open_file *f) 277 { 278 struct file *fp = NULL; 279 void *buf; 280 struct iso_primary_descriptor *vd; 281 size_t buf_size, read, dsize, off; 282 daddr_t bno, boff; 283 struct iso_directory_record rec; 284 struct iso_directory_record *dp = NULL; 285 int rc, first, use_rrip, lenskip; 286 287 /* First find the volume descriptor */ 288 buf = malloc(buf_size = ISO_DEFAULT_BLOCK_SIZE); 289 vd = buf; 290 for (bno = 16;; bno++) { 291 twiddle(1); 292 rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno), 293 ISO_DEFAULT_BLOCK_SIZE, buf, &read); 294 if (rc) 295 goto out; 296 if (read != ISO_DEFAULT_BLOCK_SIZE) { 297 rc = EIO; 298 goto out; 299 } 300 rc = EINVAL; 301 if (bcmp(vd->id, ISO_STANDARD_ID, sizeof vd->id) != 0) 302 goto out; 303 if (isonum_711(vd->type) == ISO_VD_END) 304 goto out; 305 if (isonum_711(vd->type) == ISO_VD_PRIMARY) 306 break; 307 } 308 if (isonum_723(vd->logical_block_size) != ISO_DEFAULT_BLOCK_SIZE) 309 goto out; 310 311 bcopy(vd->root_directory_record, &rec, sizeof(rec)); 312 if (*path == '/') path++; /* eat leading '/' */ 313 314 first = 1; 315 use_rrip = 0; 316 lenskip = 0; 317 while (*path) { 318 bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length); 319 dsize = isonum_733(rec.size); 320 off = 0; 321 boff = 0; 322 323 while (off < dsize) { 324 if ((off % ISO_DEFAULT_BLOCK_SIZE) == 0) { 325 twiddle(1); 326 rc = f->f_dev->dv_strategy 327 (f->f_devdata, F_READ, 328 cdb2devb(bno + boff), 329 ISO_DEFAULT_BLOCK_SIZE, 330 buf, &read); 331 if (rc) 332 goto out; 333 if (read != ISO_DEFAULT_BLOCK_SIZE) { 334 rc = EIO; 335 goto out; 336 } 337 boff++; 338 dp = (struct iso_directory_record *) buf; 339 } 340 if (isonum_711(dp->length) == 0) { 341 /* skip to next block, if any */ 342 off = boff * ISO_DEFAULT_BLOCK_SIZE; 343 continue; 344 } 345 346 /* See if RRIP is in use. */ 347 if (first) 348 use_rrip = rrip_check(f, dp, &lenskip); 349 350 if (dirmatch(f, path, dp, use_rrip, 351 first ? 0 : lenskip)) { 352 first = 0; 353 break; 354 } else 355 first = 0; 356 357 dp = (struct iso_directory_record *) 358 ((char *) dp + isonum_711(dp->length)); 359 /* If the new block has zero length, it is padding. */ 360 if (isonum_711(dp->length) == 0) { 361 /* Skip to next block, if any. */ 362 off = boff * ISO_DEFAULT_BLOCK_SIZE; 363 continue; 364 } 365 off += isonum_711(dp->length); 366 } 367 if (off >= dsize) { 368 rc = ENOENT; 369 goto out; 370 } 371 372 rec = *dp; 373 while (*path && *path != '/') /* look for next component */ 374 path++; 375 if (*path) path++; /* skip '/' */ 376 } 377 378 /* allocate file system specific data structure */ 379 fp = malloc(sizeof(struct file)); 380 bzero(fp, sizeof(struct file)); 381 f->f_fsdata = (void *)fp; 382 383 if ((isonum_711(rec.flags) & 2) != 0) { 384 fp->f_flags = F_ISDIR; 385 } 386 if (first) { 387 fp->f_flags |= F_ROOTDIR; 388 389 /* Check for Rock Ridge since we didn't in the loop above. */ 390 bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length); 391 twiddle(1); 392 rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno), 393 ISO_DEFAULT_BLOCK_SIZE, buf, &read); 394 if (rc) 395 goto out; 396 if (read != ISO_DEFAULT_BLOCK_SIZE) { 397 rc = EIO; 398 goto out; 399 } 400 dp = (struct iso_directory_record *)buf; 401 use_rrip = rrip_check(f, dp, &lenskip); 402 } 403 if (use_rrip) { 404 fp->f_flags |= F_RR; 405 fp->f_susp_skip = lenskip; 406 } 407 fp->f_off = 0; 408 fp->f_bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length); 409 fp->f_size = isonum_733(rec.size); 410 free(buf); 411 412 return 0; 413 414 out: 415 if (fp) 416 free(fp); 417 free(buf); 418 419 return rc; 420 } 421 422 static int 423 cd9660_close(struct open_file *f) 424 { 425 struct file *fp = (struct file *)f->f_fsdata; 426 427 f->f_fsdata = NULL; 428 free(fp); 429 430 return 0; 431 } 432 433 static int 434 buf_read_file(struct open_file *f, char **buf_p, size_t *size_p) 435 { 436 struct file *fp = (struct file *)f->f_fsdata; 437 daddr_t blkno, blkoff; 438 int rc = 0; 439 size_t read; 440 441 blkno = fp->f_off / ISO_DEFAULT_BLOCK_SIZE + fp->f_bno; 442 blkoff = fp->f_off % ISO_DEFAULT_BLOCK_SIZE; 443 444 if (blkno != fp->f_buf_blkno) { 445 if (fp->f_buf == (char *)0) 446 fp->f_buf = malloc(ISO_DEFAULT_BLOCK_SIZE); 447 448 twiddle(16); 449 rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, 450 cdb2devb(blkno), ISO_DEFAULT_BLOCK_SIZE, 451 fp->f_buf, &read); 452 if (rc) 453 return (rc); 454 if (read != ISO_DEFAULT_BLOCK_SIZE) 455 return (EIO); 456 457 fp->f_buf_blkno = blkno; 458 } 459 460 *buf_p = fp->f_buf + blkoff; 461 *size_p = ISO_DEFAULT_BLOCK_SIZE - blkoff; 462 463 if (*size_p > fp->f_size - fp->f_off) 464 *size_p = fp->f_size - fp->f_off; 465 return (rc); 466 } 467 468 static int 469 cd9660_read(struct open_file *f, void *start, size_t size, size_t *resid) 470 { 471 struct file *fp = (struct file *)f->f_fsdata; 472 char *buf, *addr; 473 size_t buf_size, csize; 474 int rc = 0; 475 476 addr = start; 477 while (size) { 478 if (fp->f_off < 0 || fp->f_off >= fp->f_size) 479 break; 480 481 rc = buf_read_file(f, &buf, &buf_size); 482 if (rc) 483 break; 484 485 csize = size > buf_size ? buf_size : size; 486 bcopy(buf, addr, csize); 487 488 fp->f_off += csize; 489 addr += csize; 490 size -= csize; 491 } 492 if (resid) 493 *resid = size; 494 return (rc); 495 } 496 497 static int 498 cd9660_readdir(struct open_file *f, struct dirent *d) 499 { 500 struct file *fp = (struct file *)f->f_fsdata; 501 struct iso_directory_record *ep; 502 size_t buf_size, reclen, namelen; 503 int error = 0; 504 int lenskip; 505 char *buf, *name; 506 507 again: 508 if (fp->f_off >= fp->f_size) 509 return (ENOENT); 510 error = buf_read_file(f, &buf, &buf_size); 511 if (error) 512 return (error); 513 ep = (struct iso_directory_record *)buf; 514 515 if (isonum_711(ep->length) == 0) { 516 daddr_t blkno; 517 518 /* skip to next block, if any */ 519 blkno = fp->f_off / ISO_DEFAULT_BLOCK_SIZE; 520 fp->f_off = (blkno + 1) * ISO_DEFAULT_BLOCK_SIZE; 521 goto again; 522 } 523 524 if (fp->f_flags & F_RR) { 525 if (fp->f_flags & F_ROOTDIR && fp->f_off == 0) 526 lenskip = 0; 527 else 528 lenskip = fp->f_susp_skip; 529 name = rrip_lookup_name(f, ep, lenskip, &namelen); 530 } else 531 name = NULL; 532 if (name == NULL) { 533 namelen = isonum_711(ep->name_len); 534 name = ep->name; 535 if (namelen == 1) { 536 if (ep->name[0] == 0) 537 name = "."; 538 else if (ep->name[0] == 1) { 539 namelen = 2; 540 name = ".."; 541 } 542 } 543 } 544 reclen = sizeof(struct dirent) - (MAXNAMLEN+1) + namelen + 1; 545 reclen = (reclen + 3) & ~3; 546 547 d->d_fileno = isonum_733(ep->extent); 548 d->d_reclen = reclen; 549 if (isonum_711(ep->flags) & 2) 550 d->d_type = DT_DIR; 551 else 552 d->d_type = DT_REG; 553 d->d_namlen = namelen; 554 555 bcopy(name, d->d_name, d->d_namlen); 556 d->d_name[d->d_namlen] = 0; 557 558 fp->f_off += isonum_711(ep->length); 559 return (0); 560 } 561 562 static off_t 563 cd9660_seek(struct open_file *f, off_t offset, int where) 564 { 565 struct file *fp = (struct file *)f->f_fsdata; 566 567 switch (where) { 568 case SEEK_SET: 569 fp->f_off = offset; 570 break; 571 case SEEK_CUR: 572 fp->f_off += offset; 573 break; 574 case SEEK_END: 575 fp->f_off = fp->f_size - offset; 576 break; 577 default: 578 return -1; 579 } 580 return fp->f_off; 581 } 582 583 static int 584 cd9660_stat(struct open_file *f, struct stat *sb) 585 { 586 struct file *fp = (struct file *)f->f_fsdata; 587 588 /* only important stuff */ 589 sb->st_mode = S_IRUSR | S_IRGRP | S_IROTH; 590 if (fp->f_flags & F_ISDIR) 591 sb->st_mode |= S_IFDIR; 592 else 593 sb->st_mode |= S_IFREG; 594 sb->st_uid = sb->st_gid = 0; 595 sb->st_size = fp->f_size; 596 return 0; 597 } 598