lib/libstand/cd9660.c

   1 /*
   2  * Copyright (C) 1996 Wolfgang Solfrank.
   3  * Copyright (C) 1996 TooLs GmbH.
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. All advertising materials mentioning features or use of this software
  15  *    must display the following acknowledgement:
  16  *      This product includes software developed by TooLs GmbH.
  17  * 4. The name of TooLs GmbH may not be used to endorse or promote products
  18  *    derived from this software without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
  21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  23  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  26  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  27  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  28  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  29  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  *
  31  * $NetBSD: cd9660.c,v 1.5 1997/06/26 19:11:33 drochner Exp $
  32  * $FreeBSD: src/lib/libstand/cd9660.c,v 1.4.2.4 2001/12/21 22:17:44 jhb Exp $
  33  */
  34
  35 /*
  36  * Stand-alone ISO9660 file reading package.
  37  *
  38  * Note: This doesn't support Rock Ridge extensions, extended attributes,
  39  * blocksizes other than 2048 bytes, multi-extent files, etc.
  40  */
  41 #include <sys/param.h>
  42 #include <string.h>
  43 #include <sys/dirent.h>
  44 #include <isofs/cd9660/iso.h>
  45 #include <isofs/cd9660/cd9660_rrip.h>
  46
  47 #include "stand.h"
  48
  49 #define SUSP_CONTINUATION       "CE"
  50 #define SUSP_PRESENT            "SP"
  51 #define SUSP_STOP               "ST"
  52 #define SUSP_EXTREF             "ER"
  53 #define RRIP_NAME               "NM"
  54
  55 typedef struct {
  56         ISO_SUSP_HEADER         h;
  57         u_char signature        [ISODCL (  5,    6)];
  58         u_char len_skp          [ISODCL (  7,    7)]; /* 711 */
  59 } ISO_SUSP_PRESENT;
  60
  61 static int      buf_read_file(struct open_file *f, char **buf_p,
  62                     size_t *size_p);
  63 static int      cd9660_open(const char *path, struct open_file *f);
  64 static int      cd9660_close(struct open_file *f);
  65 static int      cd9660_read(struct open_file *f, void *buf, size_t size,
  66                     size_t *resid);
  67 static int      cd9660_write(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         cd9660_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         u_daddr_t       f_bno;          /* Starting block number */
 101         off_t           f_size;         /* Size of file */
 102         u_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         return (NULL);
 157 }
 158
 159 static char *
 160 rrip_lookup_name(struct open_file *f, struct iso_directory_record *dp,
 161     int lenskip, size_t *len)
 162 {
 163         ISO_RRIP_ALTNAME *p;
 164
 165         if (len == NULL)
 166                 return (NULL);
 167
 168         p = (ISO_RRIP_ALTNAME *)susp_lookup_record(f, RRIP_NAME, dp, lenskip);
 169         if (p == NULL)
 170                 return (NULL);
 171         switch (*p->flags) {
 172         case ISO_SUSP_CFLAG_CURRENT:
 173                 *len = 1;
 174                 return (".");
 175         case ISO_SUSP_CFLAG_PARENT:
 176                 *len = 2;
 177                 return ("..");
 178         case 0:
 179                 *len = isonum_711(p->h.length) - 5;
 180                 return ((char *)p + 5);
 181         default:
 182                 /*
 183                  * We don't handle hostnames or continued names as they are
 184                  * too hard, so just bail and use the default name.
 185                  */
 186                 return (NULL);
 187         }
 188 }
 189
 190 static int
 191 rrip_check(struct open_file *f, struct iso_directory_record *dp, int *lenskip)
 192 {
 193         ISO_SUSP_PRESENT *sp;
 194         ISO_RRIP_EXTREF *er;
 195         char *p;
 196
 197         /* First, see if we can find a SP field. */
 198         p = dp->name + isonum_711(dp->name_len);
 199         if (p > (char *)dp + isonum_711(dp->length))
 200                 return (0);
 201         sp = (ISO_SUSP_PRESENT *)p;
 202         if (bcmp(sp->h.type, SUSP_PRESENT, 2) != 0)
 203                 return (0);
 204         if (isonum_711(sp->h.length) != sizeof(ISO_SUSP_PRESENT))
 205                 return (0);
 206         if (sp->signature[0] != 0xbe || sp->signature[1] != 0xef)
 207                 return (0);
 208         *lenskip = isonum_711(sp->len_skp);
 209
 210         /*
 211          * Now look for an ER field.  If RRIP is present, then there must
 212          * be at least one of these.  It would be more pedantic to walk
 213          * through the list of fields looking for a Rock Ridge ER field.
 214          */
 215         er = (ISO_RRIP_EXTREF *)susp_lookup_record(f, SUSP_EXTREF, dp, 0);
 216         if (er == NULL)
 217                 return (0);
 218         return (1);
 219 }
 220
 221 static int
 222 dirmatch(struct open_file *f, const char *path, struct iso_directory_record *dp,
 223     int use_rrip, int lenskip)
 224 {
 225         size_t len;
 226         char *cp;
 227         int i, icase;
 228
 229         if (use_rrip)
 230                 cp = rrip_lookup_name(f, dp, lenskip, &len);
 231         else
 232                 cp = NULL;
 233         if (cp == NULL) {
 234                 len = isonum_711(dp->name_len);
 235                 cp = dp->name;
 236                 icase = 1;
 237         } else
 238                 icase = 0;
 239         for (i = len; --i >= 0; path++, cp++) {
 240                 if (!*path || *path == '/')
 241                         break;
 242                 if (*path == *cp)
 243                         continue;
 244                 if (!icase && toupper(*path) == *cp)
 245                         continue;
 246                 return 0;
 247         }
 248         if (*path && *path != '/')
 249                 return 0;
 250
 251         /*
 252          * Allow stripping of trailing dots and the version number.
 253          *
 254          * Note that this will find the first instead of the last version
 255          * of a file unless explicitly specified.
 256          *
 257          * For any inexact matches we ignore everything after and including
 258          * the semicolon in the directory entry name, assuming it is a
 259          * version number whether it is or not.
 260          */
 261         if (i >= 0) {
 262                 if (cp[0] == ';')
 263                         return 1;       /* ignore version */
 264                 if (cp[0] == '.' && i == 0)
 265                         return 1;       /* ignore trailing dot */
 266                 if (cp[0] == '.' && i > 0 && cp[1] == ';')
 267                         return 1;       /* ignore trailing dot w/ version */
 268                 return 0;               /* else mismatch */
 269         }
 270         return 1;
 271 }
 272
 273 static int
 274 cd9660_open(const char *path, struct open_file *f)
 275 {
 276         struct file *fp = NULL;
 277         void *buf;
 278         struct iso_primary_descriptor *vd;
 279         size_t buf_size, read, dsize, off;
 280         u_daddr_t bno, boff;
 281         struct iso_directory_record rec;
 282         struct iso_directory_record *dp = NULL;
 283         int rc, first, use_rrip, lenskip;
 284
 285         /* First find the volume descriptor */
 286         buf = malloc(buf_size = ISO_DEFAULT_BLOCK_SIZE);
 287         vd = buf;
 288         for (bno = 16;; bno++) {
 289                 twiddle();
 290                 rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno),
 291                                            ISO_DEFAULT_BLOCK_SIZE, buf, &read);
 292                 if (rc)
 293                         goto out;
 294                 if (read != ISO_DEFAULT_BLOCK_SIZE) {
 295                         rc = EIO;
 296                         goto out;
 297                 }
 298                 rc = EINVAL;
 299                 if (bcmp(vd->id, ISO_STANDARD_ID, sizeof vd->id) != 0)
 300                         goto out;
 301                 if (isonum_711(vd->type) == ISO_VD_END)
 302                         goto out;
 303                 if (isonum_711(vd->type) == ISO_VD_PRIMARY)
 304                         break;
 305         }
 306         if (isonum_723(vd->logical_block_size) != ISO_DEFAULT_BLOCK_SIZE)
 307                 goto out;
 308
 309         rec = *(struct iso_directory_record *) vd->root_directory_record;
 310         if (*path == '/') path++; /* eat leading '/' */
 311
 312         first = 1;
 313         use_rrip = 0;
 314         while (*path) {
 315                 bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length);
 316                 dsize = isonum_733(rec.size);
 317                 off = 0;
 318                 boff = 0;
 319
 320                 while (off < dsize) {
 321                         if ((off % ISO_DEFAULT_BLOCK_SIZE) == 0) {
 322                                 twiddle();
 323                                 rc = f->f_dev->dv_strategy
 324                                         (f->f_devdata, F_READ,
 325                                          cdb2devb(bno + boff),
 326                                          ISO_DEFAULT_BLOCK_SIZE,
 327                                          buf, &read);
 328                                 if (rc)
 329                                         goto out;
 330                                 if (read != ISO_DEFAULT_BLOCK_SIZE) {
 331                                         rc = EIO;
 332                                         goto out;
 333                                 }
 334                                 boff++;
 335                                 dp = (struct iso_directory_record *) buf;
 336                         }
 337                         if (isonum_711(dp->length) == 0) {
 338                             /* skip to next block, if any */
 339                             off = boff * ISO_DEFAULT_BLOCK_SIZE;
 340                             continue;
 341                         }
 342
 343                         /* See if RRIP is in use. */
 344                         if (first)
 345                                 use_rrip = rrip_check(f, dp, &lenskip);
 346
 347                         if (dirmatch(f, path, dp, use_rrip,
 348                                 first ? 0 : lenskip)) {
 349                                 first = 0;
 350                                 break;
 351                         } else
 352                                 first = 0;
 353
 354                         dp = (struct iso_directory_record *)
 355                                 ((char *) dp + isonum_711(dp->length));
 356                         off += isonum_711(dp->length);
 357                 }
 358                 if (off >= dsize) {
 359                         rc = ENOENT;
 360                         goto out;
 361                 }
 362
 363                 rec = *dp;
 364                 while (*path && *path != '/') /* look for next component */
 365                         path++;
 366                 if (*path == '/') {     /* skip /, make sure is dir */
 367                         path++;
 368                         if (*path && (isonum_711(dp->flags) & 2) == 0) {
 369                                 rc = ENOENT;    /* not directory */
 370                                 goto out;
 371                         }
 372                 }
 373         }
 374
 375         /* allocate file system specific data structure */
 376         fp = malloc(sizeof(struct file));
 377         bzero(fp, sizeof(struct file));
 378         f->f_fsdata = (void *)fp;
 379
 380         if ((isonum_711(rec.flags) & 2) != 0) {
 381                 fp->f_flags = F_ISDIR;
 382         }
 383         if (first) {
 384                 fp->f_flags |= F_ROOTDIR;
 385
 386                 /* Check for Rock Ridge since we didn't in the loop above. */
 387                 bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length);
 388                 twiddle();
 389                 rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno),
 390                     ISO_DEFAULT_BLOCK_SIZE, buf, &read);
 391                 if (rc)
 392                         goto out;
 393                 if (read != ISO_DEFAULT_BLOCK_SIZE) {
 394                         rc = EIO;
 395                         goto out;
 396                 }
 397                 dp = (struct iso_directory_record *)buf;
 398                 use_rrip = rrip_check(f, dp, &lenskip);
 399         }
 400         if (use_rrip) {
 401                 fp->f_flags |= F_RR;
 402                 fp->f_susp_skip = lenskip;
 403         }
 404         fp->f_off = 0;
 405         fp->f_bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length);
 406         fp->f_size = isonum_733(rec.size);
 407         free(buf);
 408
 409         return 0;
 410
 411 out:
 412         f->f_fsdata = NULL;
 413         if (fp)
 414                 free(fp);
 415         free(buf);
 416
 417         return rc;
 418 }
 419
 420 static int
 421 cd9660_close(struct open_file *f)
 422 {
 423         struct file *fp = (struct file *)f->f_fsdata;
 424
 425         f->f_fsdata = NULL;
 426         if (fp)
 427                 free(fp);
 428
 429         return 0;
 430 }
 431
 432 static int
 433 buf_read_file(struct open_file *f, char **buf_p, size_t *size_p)
 434 {
 435         struct file *fp = (struct file *)f->f_fsdata;
 436         u_daddr_t blkno, blkoff;
 437         int rc = 0;
 438         size_t read;
 439
 440         blkno = fp->f_off / ISO_DEFAULT_BLOCK_SIZE + fp->f_bno;
 441         blkoff = fp->f_off % ISO_DEFAULT_BLOCK_SIZE;
 442
 443         if (blkno != fp->f_buf_blkno) {
 444                 if (fp->f_buf == NULL)
 445                         fp->f_buf = malloc(ISO_DEFAULT_BLOCK_SIZE);
 446
 447                 twiddle();
 448                 rc = f->f_dev->dv_strategy(f->f_devdata, F_READ,
 449                     cdb2devb(blkno), ISO_DEFAULT_BLOCK_SIZE, fp->f_buf, &read);
 450                 if (rc)
 451                         return (rc);
 452                 if (read != ISO_DEFAULT_BLOCK_SIZE)
 453                         return (EIO);
 454
 455                 fp->f_buf_blkno = blkno;
 456         }
 457
 458         *buf_p = fp->f_buf + blkoff;
 459         *size_p = ISO_DEFAULT_BLOCK_SIZE - blkoff;
 460
 461         if (*size_p > fp->f_size - fp->f_off)
 462                 *size_p = fp->f_size - fp->f_off;
 463         return (rc);
 464 }
 465
 466 static int
 467 cd9660_read(struct open_file *f, void *start, size_t size, size_t *resid)
 468 {
 469         struct file *fp = (struct file *)f->f_fsdata;
 470         char *buf, *addr;
 471         size_t buf_size, csize;
 472         int rc = 0;
 473
 474         addr = start;
 475         while (size) {
 476                 if (fp->f_off < 0 || fp->f_off >= fp->f_size)
 477                         break;
 478
 479                 rc = buf_read_file(f, &buf, &buf_size);
 480                 if (rc)
 481                         break;
 482
 483                 csize = size > buf_size ? buf_size : size;
 484                 bcopy(buf, addr, csize);
 485
 486                 fp->f_off += csize;
 487                 addr += csize;
 488                 size -= csize;
 489         }
 490         if (resid)
 491                 *resid = size;
 492         return (rc);
 493 }
 494
 495 static int
 496 cd9660_readdir(struct open_file *f, struct dirent *d)
 497 {
 498         struct file *fp = (struct file *)f->f_fsdata;
 499         struct iso_directory_record *ep;
 500         size_t buf_size, namelen;
 501         int error = 0;
 502         int lenskip;
 503         char *buf, *name;
 504
 505 again:
 506         if (fp->f_off >= fp->f_size)
 507                 return (ENOENT);
 508         error = buf_read_file(f, &buf, &buf_size);
 509         if (error)
 510                 return (error);
 511         ep = (struct iso_directory_record *)buf;
 512
 513         if (isonum_711(ep->length) == 0) {
 514                 u_daddr_t blkno;
 515
 516                 /* skip to next block, if any */
 517                 blkno = fp->f_off / ISO_DEFAULT_BLOCK_SIZE;
 518                 fp->f_off = (blkno + 1) * ISO_DEFAULT_BLOCK_SIZE;
 519                 goto again;
 520         }
 521
 522         if (fp->f_flags & F_RR) {
 523                 if (fp->f_flags & F_ROOTDIR && fp->f_off == 0)
 524                         lenskip = 0;
 525                 else
 526                         lenskip = fp->f_susp_skip;
 527                 name = rrip_lookup_name(f, ep, lenskip, &namelen);
 528         } else
 529                 name = NULL;
 530         if (name == NULL) {
 531                 namelen = isonum_711(ep->name_len);
 532                 name = ep->name;
 533                 if (namelen == 1) {
 534                         if (ep->name[0] == 0)
 535                                 name = ".";
 536                         else if (ep->name[0] == 1) {
 537                                 namelen = 2;
 538                                 name = "..";
 539                         }
 540                 }
 541         }
 542
 543         d->d_ino = isonum_733(ep->extent);
 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
 557 static int
 558 cd9660_write(struct open_file *f, void *start, size_t size, size_t *resid)
 559 {
 560         return EROFS;
 561 }
 562
 563 static off_t
 564 cd9660_seek(struct open_file *f, off_t offset, int where)
 565 {
 566         struct file *fp = (struct file *)f->f_fsdata;
 567
 568         switch (where) {
 569         case SEEK_SET:
 570                 fp->f_off = offset;
 571                 break;
 572         case SEEK_CUR:
 573                 fp->f_off += offset;
 574                 break;
 575         case SEEK_END:
 576                 fp->f_off = fp->f_size - offset;
 577                 break;
 578         default:
 579                 return -1;
 580         }
 581         return fp->f_off;
 582 }
 583
 584 static int
 585 cd9660_stat(struct open_file *f, struct stat *sb)
 586 {
 587         struct file *fp = (struct file *)f->f_fsdata;
 588
 589         /* only important stuff */
 590         sb->st_mode = S_IRUSR | S_IRGRP | S_IROTH;
 591         if (fp->f_flags & F_ISDIR)
 592                 sb->st_mode |= S_IFDIR;
 593         else
 594                 sb->st_mode |= S_IFREG;
 595         sb->st_uid = sb->st_gid = 0;
 596         sb->st_size = fp->f_size;
 597         return 0;
 598 }