cd9660.c revision 332141
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: stable/11/stand/libsa/cd9660.c 332141 2018-04-06 19:34:21Z kevans $"); 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 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 off_t cd9660_seek(struct open_file *f, off_t offset, int where); 70static int cd9660_stat(struct open_file *f, struct stat *sb); 71static int cd9660_readdir(struct open_file *f, struct dirent *d); 72static int dirmatch(struct open_file *f, const char *path, 73 struct iso_directory_record *dp, int use_rrip, int lenskip); 74static int rrip_check(struct open_file *f, struct iso_directory_record *dp, 75 int *lenskip); 76static char *rrip_lookup_name(struct open_file *f, 77 struct iso_directory_record *dp, int lenskip, size_t *len); 78static ISO_SUSP_HEADER *susp_lookup_record(struct open_file *f, 79 const char *identifier, struct iso_directory_record *dp, 80 int lenskip); 81 82struct 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 97struct 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 107struct 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 119static ISO_SUSP_HEADER * 120susp_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 164static char * 165rrip_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 195static int 196rrip_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 226static int 227dirmatch(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 for (i = len; --i >= 0; path++, cp++) { 245 if (!*path || *path == '/') 246 break; 247 if (*path == *cp) 248 continue; 249 if (!icase && toupper(*path) == *cp) 250 continue; 251 return 0; 252 } 253 if (*path && *path != '/') 254 return 0; 255 /* 256 * Allow stripping of trailing dots and the version number. 257 * Note that this will find the first instead of the last version 258 * of a file. 259 */ 260 if (i >= 0 && (*cp == ';' || *cp == '.')) { 261 /* This is to prevent matching of numeric extensions */ 262 if (*cp == '.' && cp[1] != ';') 263 return 0; 264 while (--i >= 0) 265 if (*++cp != ';' && (*cp < '0' || *cp > '9')) 266 return 0; 267 } 268 return 1; 269} 270 271static int 272cd9660_open(const char *path, struct open_file *f) 273{ 274 struct file *fp = NULL; 275 void *buf; 276 struct iso_primary_descriptor *vd; 277 size_t buf_size, read, dsize, off; 278 daddr_t bno, boff; 279 struct iso_directory_record rec; 280 struct iso_directory_record *dp = NULL; 281 int rc, first, use_rrip, lenskip; 282 283 /* First find the volume descriptor */ 284 buf = malloc(buf_size = ISO_DEFAULT_BLOCK_SIZE); 285 vd = buf; 286 for (bno = 16;; bno++) { 287 twiddle(1); 288 rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno), 289 ISO_DEFAULT_BLOCK_SIZE, buf, &read); 290 if (rc) 291 goto out; 292 if (read != ISO_DEFAULT_BLOCK_SIZE) { 293 rc = EIO; 294 goto out; 295 } 296 rc = EINVAL; 297 if (bcmp(vd->id, ISO_STANDARD_ID, sizeof vd->id) != 0) 298 goto out; 299 if (isonum_711(vd->type) == ISO_VD_END) 300 goto out; 301 if (isonum_711(vd->type) == ISO_VD_PRIMARY) 302 break; 303 } 304 if (isonum_723(vd->logical_block_size) != ISO_DEFAULT_BLOCK_SIZE) 305 goto out; 306 307 rec = *(struct iso_directory_record *) vd->root_directory_record; 308 if (*path == '/') path++; /* eat leading '/' */ 309 310 first = 1; 311 use_rrip = 0; 312 while (*path) { 313 bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length); 314 dsize = isonum_733(rec.size); 315 off = 0; 316 boff = 0; 317 318 while (off < dsize) { 319 if ((off % ISO_DEFAULT_BLOCK_SIZE) == 0) { 320 twiddle(1); 321 rc = f->f_dev->dv_strategy 322 (f->f_devdata, F_READ, 323 cdb2devb(bno + boff), 324 ISO_DEFAULT_BLOCK_SIZE, 325 buf, &read); 326 if (rc) 327 goto out; 328 if (read != ISO_DEFAULT_BLOCK_SIZE) { 329 rc = EIO; 330 goto out; 331 } 332 boff++; 333 dp = (struct iso_directory_record *) buf; 334 } 335 if (isonum_711(dp->length) == 0) { 336 /* skip to next block, if any */ 337 off = boff * ISO_DEFAULT_BLOCK_SIZE; 338 continue; 339 } 340 341 /* See if RRIP is in use. */ 342 if (first) 343 use_rrip = rrip_check(f, dp, &lenskip); 344 345 if (dirmatch(f, path, dp, use_rrip, 346 first ? 0 : lenskip)) { 347 first = 0; 348 break; 349 } else 350 first = 0; 351 352 dp = (struct iso_directory_record *) 353 ((char *) dp + isonum_711(dp->length)); 354 /* If the new block has zero length, it is padding. */ 355 if (isonum_711(dp->length) == 0) { 356 /* Skip to next block, if any. */ 357 off = boff * ISO_DEFAULT_BLOCK_SIZE; 358 continue; 359 } 360 off += isonum_711(dp->length); 361 } 362 if (off >= dsize) { 363 rc = ENOENT; 364 goto out; 365 } 366 367 rec = *dp; 368 while (*path && *path != '/') /* look for next component */ 369 path++; 370 if (*path) path++; /* skip '/' */ 371 } 372 373 /* allocate file system specific data structure */ 374 fp = malloc(sizeof(struct file)); 375 bzero(fp, sizeof(struct file)); 376 f->f_fsdata = (void *)fp; 377 378 if ((isonum_711(rec.flags) & 2) != 0) { 379 fp->f_flags = F_ISDIR; 380 } 381 if (first) { 382 fp->f_flags |= F_ROOTDIR; 383 384 /* Check for Rock Ridge since we didn't in the loop above. */ 385 bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length); 386 twiddle(1); 387 rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno), 388 ISO_DEFAULT_BLOCK_SIZE, buf, &read); 389 if (rc) 390 goto out; 391 if (read != ISO_DEFAULT_BLOCK_SIZE) { 392 rc = EIO; 393 goto out; 394 } 395 dp = (struct iso_directory_record *)buf; 396 use_rrip = rrip_check(f, dp, &lenskip); 397 } 398 if (use_rrip) { 399 fp->f_flags |= F_RR; 400 fp->f_susp_skip = lenskip; 401 } 402 fp->f_off = 0; 403 fp->f_bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length); 404 fp->f_size = isonum_733(rec.size); 405 free(buf); 406 407 return 0; 408 409out: 410 if (fp) 411 free(fp); 412 free(buf); 413 414 return rc; 415} 416 417static int 418cd9660_close(struct open_file *f) 419{ 420 struct file *fp = (struct file *)f->f_fsdata; 421 422 f->f_fsdata = NULL; 423 free(fp); 424 425 return 0; 426} 427 428static int 429buf_read_file(struct open_file *f, char **buf_p, size_t *size_p) 430{ 431 struct file *fp = (struct file *)f->f_fsdata; 432 daddr_t blkno, blkoff; 433 int rc = 0; 434 size_t read; 435 436 blkno = fp->f_off / ISO_DEFAULT_BLOCK_SIZE + fp->f_bno; 437 blkoff = fp->f_off % ISO_DEFAULT_BLOCK_SIZE; 438 439 if (blkno != fp->f_buf_blkno) { 440 if (fp->f_buf == (char *)0) 441 fp->f_buf = malloc(ISO_DEFAULT_BLOCK_SIZE); 442 443 twiddle(16); 444 rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, 445 cdb2devb(blkno), ISO_DEFAULT_BLOCK_SIZE, 446 fp->f_buf, &read); 447 if (rc) 448 return (rc); 449 if (read != ISO_DEFAULT_BLOCK_SIZE) 450 return (EIO); 451 452 fp->f_buf_blkno = blkno; 453 } 454 455 *buf_p = fp->f_buf + blkoff; 456 *size_p = ISO_DEFAULT_BLOCK_SIZE - blkoff; 457 458 if (*size_p > fp->f_size - fp->f_off) 459 *size_p = fp->f_size - fp->f_off; 460 return (rc); 461} 462 463static int 464cd9660_read(struct open_file *f, void *start, size_t size, size_t *resid) 465{ 466 struct file *fp = (struct file *)f->f_fsdata; 467 char *buf, *addr; 468 size_t buf_size, csize; 469 int rc = 0; 470 471 addr = start; 472 while (size) { 473 if (fp->f_off < 0 || fp->f_off >= fp->f_size) 474 break; 475 476 rc = buf_read_file(f, &buf, &buf_size); 477 if (rc) 478 break; 479 480 csize = size > buf_size ? buf_size : size; 481 bcopy(buf, addr, csize); 482 483 fp->f_off += csize; 484 addr += csize; 485 size -= csize; 486 } 487 if (resid) 488 *resid = size; 489 return (rc); 490} 491 492static int 493cd9660_readdir(struct open_file *f, struct dirent *d) 494{ 495 struct file *fp = (struct file *)f->f_fsdata; 496 struct iso_directory_record *ep; 497 size_t buf_size, reclen, namelen; 498 int error = 0; 499 int lenskip; 500 char *buf, *name; 501 502again: 503 if (fp->f_off >= fp->f_size) 504 return (ENOENT); 505 error = buf_read_file(f, &buf, &buf_size); 506 if (error) 507 return (error); 508 ep = (struct iso_directory_record *)buf; 509 510 if (isonum_711(ep->length) == 0) { 511 daddr_t blkno; 512 513 /* skip to next block, if any */ 514 blkno = fp->f_off / ISO_DEFAULT_BLOCK_SIZE; 515 fp->f_off = (blkno + 1) * ISO_DEFAULT_BLOCK_SIZE; 516 goto again; 517 } 518 519 if (fp->f_flags & F_RR) { 520 if (fp->f_flags & F_ROOTDIR && fp->f_off == 0) 521 lenskip = 0; 522 else 523 lenskip = fp->f_susp_skip; 524 name = rrip_lookup_name(f, ep, lenskip, &namelen); 525 } else 526 name = NULL; 527 if (name == NULL) { 528 namelen = isonum_711(ep->name_len); 529 name = ep->name; 530 if (namelen == 1) { 531 if (ep->name[0] == 0) 532 name = "."; 533 else if (ep->name[0] == 1) { 534 namelen = 2; 535 name = ".."; 536 } 537 } 538 } 539 reclen = sizeof(struct dirent) - (MAXNAMLEN+1) + namelen + 1; 540 reclen = (reclen + 3) & ~3; 541 542 d->d_fileno = isonum_733(ep->extent); 543 d->d_reclen = reclen; 544 if (isonum_711(ep->flags) & 2) 545 d->d_type = DT_DIR; 546 else 547 d->d_type = DT_REG; 548 d->d_namlen = namelen; 549 550 bcopy(name, d->d_name, d->d_namlen); 551 d->d_name[d->d_namlen] = 0; 552 553 fp->f_off += isonum_711(ep->length); 554 return (0); 555} 556 557static off_t 558cd9660_seek(struct open_file *f, off_t offset, int where) 559{ 560 struct file *fp = (struct file *)f->f_fsdata; 561 562 switch (where) { 563 case SEEK_SET: 564 fp->f_off = offset; 565 break; 566 case SEEK_CUR: 567 fp->f_off += offset; 568 break; 569 case SEEK_END: 570 fp->f_off = fp->f_size - offset; 571 break; 572 default: 573 return -1; 574 } 575 return fp->f_off; 576} 577 578static int 579cd9660_stat(struct open_file *f, struct stat *sb) 580{ 581 struct file *fp = (struct file *)f->f_fsdata; 582 583 /* only important stuff */ 584 sb->st_mode = S_IRUSR | S_IRGRP | S_IROTH; 585 if (fp->f_flags & F_ISDIR) 586 sb->st_mode |= S_IFDIR; 587 else 588 sb->st_mode |= S_IFREG; 589 sb->st_uid = sb->st_gid = 0; 590 sb->st_size = fp->f_size; 591 return 0; 592} 593