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cd9660.c revision 1.23
      1 /*	$NetBSD: cd9660.c,v 1.23 2007/11/24 13:20:54 isaki 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 /*
     35  * Stand-alone ISO9660 file reading package.
     36  *
     37  * Note: This doesn't support Rock Ridge extensions, extended attributes,
     38  * blocksizes other than 2048 bytes, multi-extent files, etc.
     39  */
     40 #include <sys/param.h>
     41 #ifdef _STANDALONE
     42 #include <lib/libkern/libkern.h>
     43 #else
     44 #include <string.h>
     45 #endif
     46 #include <fs/cd9660/iso.h>
     47 
     48 #include "stand.h"
     49 #include "cd9660.h"
     50 
     51 /*
     52  * XXX Does not currently implement:
     53  * XXX
     54  * XXX LIBSA_NO_FS_SYMLINK (does this even make sense?)
     55  * XXX LIBSA_FS_SINGLECOMPONENT
     56  */
     57 
     58 struct file {
     59 	off_t off;			/* Current offset within file */
     60 	daddr_t bno;			/* Starting block number  */
     61 	off_t size;			/* Size of file */
     62 };
     63 
     64 struct ptable_ent {
     65 	char namlen	[ISODCL( 1, 1)];	/* 711 */
     66 	char extlen	[ISODCL( 2, 2)];	/* 711 */
     67 	char block	[ISODCL( 3, 6)];	/* 732 */
     68 	char parent	[ISODCL( 7, 8)];	/* 722 */
     69 	char name	[1];
     70 };
     71 #define	PTFIXSZ		8
     72 #define	PTSIZE(pp)	roundup(PTFIXSZ + isonum_711((pp)->namlen), 2)
     73 
     74 #define	cdb2devb(bno)	((bno) * ISO_DEFAULT_BLOCK_SIZE / DEV_BSIZE)
     75 
     76 static int	pnmatch(const char *, struct ptable_ent *);
     77 static int	dirmatch(const char *, struct iso_directory_record *);
     78 
     79 static int
     80 pnmatch(const char *path, struct ptable_ent *pp)
     81 {
     82 	char *cp;
     83 	int i;
     84 
     85 	cp = pp->name;
     86 	for (i = isonum_711(pp->namlen); --i >= 0; path++, cp++) {
     87 		if (toupper(*path) == *cp)
     88 			continue;
     89 		return 0;
     90 	}
     91 	if (*path != '/')
     92 		return 0;
     93 	return 1;
     94 }
     95 
     96 static int
     97 dirmatch(const char *path, struct iso_directory_record *dp)
     98 {
     99 	char *cp;
    100 	int i;
    101 
    102 	/* This needs to be a regular file */
    103 	if (dp->flags[0] & 6)
    104 		return 0;
    105 
    106 	cp = dp->name;
    107 	for (i = isonum_711(dp->name_len); --i >= 0; path++, cp++) {
    108 		if (!*path)
    109 			break;
    110 		if (toupper(*path) == *cp)
    111 			continue;
    112 		return 0;
    113 	}
    114 	if (*path)
    115 		return 0;
    116 	/*
    117 	 * Allow stripping of trailing dots and the version number.
    118 	 * Note that this will find the first instead of the last version
    119 	 * of a file.
    120 	 */
    121 	if (i >= 0 && (*cp == ';' || *cp == '.')) {
    122 		/* This is to prevent matching of numeric extensions */
    123 		if (*cp == '.' && cp[1] != ';')
    124 			return 0;
    125 		while (--i >= 0)
    126 			if (*++cp != ';' && (*cp < '0' || *cp > '9'))
    127 				return 0;
    128 	}
    129 	return 1;
    130 }
    131 
    132 int
    133 cd9660_open(const char *path, struct open_file *f)
    134 {
    135 	struct file *fp = 0;
    136 	void *buf;
    137 	struct iso_primary_descriptor *vd;
    138 	size_t buf_size, nread, psize, dsize;
    139 	daddr_t bno;
    140 	int parent, ent;
    141 	struct ptable_ent *pp;
    142 	struct iso_directory_record *dp = 0;
    143 	int rc;
    144 
    145 	/* First find the volume descriptor */
    146 	buf_size = ISO_DEFAULT_BLOCK_SIZE;
    147 	buf = alloc(buf_size);
    148 	vd = buf;
    149 	for (bno = 16;; bno++) {
    150 #if !defined(LIBSA_NO_TWIDDLE)
    151 		twiddle();
    152 #endif
    153 		rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ, cdb2devb(bno),
    154 					   ISO_DEFAULT_BLOCK_SIZE, buf, &nread);
    155 		if (rc)
    156 			goto out;
    157 		if (nread != ISO_DEFAULT_BLOCK_SIZE) {
    158 			rc = EIO;
    159 			goto out;
    160 		}
    161 		rc = EINVAL;
    162 		if (memcmp(vd->id, ISO_STANDARD_ID, sizeof vd->id) != 0)
    163 			goto out;
    164 		if (isonum_711(vd->type) == ISO_VD_END)
    165 			goto out;
    166 		if (isonum_711(vd->type) == ISO_VD_PRIMARY)
    167 			break;
    168 	}
    169 	if (isonum_723(vd->logical_block_size) != ISO_DEFAULT_BLOCK_SIZE)
    170 		goto out;
    171 
    172 	/* Now get the path table and lookup the directory of the file */
    173 	bno = isonum_732(vd->type_m_path_table);
    174 	psize = isonum_733(vd->path_table_size);
    175 
    176 	if (psize > ISO_DEFAULT_BLOCK_SIZE) {
    177 		dealloc(buf, ISO_DEFAULT_BLOCK_SIZE);
    178 		buf = alloc(buf_size = roundup(psize, ISO_DEFAULT_BLOCK_SIZE));
    179 	}
    180 
    181 #if !defined(LIBSA_NO_TWIDDLE)
    182 	twiddle();
    183 #endif
    184 	rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ, cdb2devb(bno),
    185 	                           buf_size, buf, &nread);
    186 	if (rc)
    187 		goto out;
    188 	if (nread != buf_size) {
    189 		rc = EIO;
    190 		goto out;
    191 	}
    192 
    193 	parent = 1;
    194 	pp = (struct ptable_ent *)buf;
    195 	ent = 1;
    196 	bno = isonum_732(pp->block) + isonum_711(pp->extlen);
    197 
    198 	rc = ENOENT;
    199 	/*
    200 	 * Remove extra separators
    201 	 */
    202 	while (*path == '/')
    203 		path++;
    204 
    205 	while (*path) {
    206 		if ((char *)pp >= (char *)buf + psize)
    207 			break;
    208 		if (isonum_722(pp->parent) != parent)
    209 			break;
    210 		if (!pnmatch(path, pp)) {
    211 			pp = (struct ptable_ent *)((char *)pp + PTSIZE(pp));
    212 			ent++;
    213 			continue;
    214 		}
    215 		path += isonum_711(pp->namlen) + 1;
    216 		parent = ent;
    217 		bno = isonum_732(pp->block) + isonum_711(pp->extlen);
    218 		while ((char *)pp < (char *)buf + psize) {
    219 			if (isonum_722(pp->parent) == parent)
    220 				break;
    221 			pp = (struct ptable_ent *)((char *)pp + PTSIZE(pp));
    222 			ent++;
    223 		}
    224 	}
    225 
    226 	/*
    227 	 * Now bno has the start of the directory that supposedly
    228 	 * contains the file
    229 	 */
    230 	bno--;
    231 	dsize = 1;		/* Something stupid, but > 0 XXX */
    232 	for (psize = 0; psize < dsize;) {
    233 		if (!(psize % ISO_DEFAULT_BLOCK_SIZE)) {
    234 			bno++;
    235 #if !defined(LIBSA_NO_TWIDDLE)
    236 			twiddle();
    237 #endif
    238 			rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
    239 			                           cdb2devb(bno),
    240 			                           ISO_DEFAULT_BLOCK_SIZE,
    241 			                           buf, &nread);
    242 			if (rc)
    243 				goto out;
    244 			if (nread != ISO_DEFAULT_BLOCK_SIZE) {
    245 				rc = EIO;
    246 				goto out;
    247 			}
    248 			dp = (struct iso_directory_record *)buf;
    249 		}
    250 		if (!isonum_711(dp->length)) {
    251 			if ((void *)dp == buf)
    252 				psize += ISO_DEFAULT_BLOCK_SIZE;
    253 			else
    254 				psize = roundup(psize, ISO_DEFAULT_BLOCK_SIZE);
    255 			continue;
    256 		}
    257 		if (dsize == 1)
    258 			dsize = isonum_733(dp->size);
    259 		if (dirmatch(path, dp))
    260 			break;
    261 		psize += isonum_711(dp->length);
    262 		dp = (struct iso_directory_record *)
    263 			((char *)dp + isonum_711(dp->length));
    264 	}
    265 
    266 	if (psize >= dsize) {
    267 		rc = ENOENT;
    268 		goto out;
    269 	}
    270 
    271 	/* allocate file system specific data structure */
    272 	fp = alloc(sizeof(struct file));
    273 	memset(fp, 0, sizeof(struct file));
    274 	f->f_fsdata = (void *)fp;
    275 
    276 	fp->off = 0;
    277 	fp->bno = isonum_733(dp->extent);
    278 	fp->size = isonum_733(dp->size);
    279 	dealloc(buf, buf_size);
    280 
    281 	return 0;
    282 
    283 out:
    284 	if (fp)
    285 		dealloc(fp, sizeof(struct file));
    286 	dealloc(buf, buf_size);
    287 
    288 	return rc;
    289 }
    290 
    291 #if !defined(LIBSA_NO_FS_CLOSE)
    292 int
    293 cd9660_close(struct open_file *f)
    294 {
    295 	struct file *fp = (struct file *)f->f_fsdata;
    296 
    297 	f->f_fsdata = 0;
    298 	dealloc(fp, sizeof *fp);
    299 
    300 	return 0;
    301 }
    302 #endif /* !defined(LIBSA_NO_FS_CLOSE) */
    303 
    304 int
    305 cd9660_read(struct open_file *f, void *start, size_t size, size_t *resid)
    306 {
    307 	struct file *fp = (struct file *)f->f_fsdata;
    308 	int rc = 0;
    309 	daddr_t bno;
    310 	char buf[ISO_DEFAULT_BLOCK_SIZE];
    311 	char *dp;
    312 	size_t nread, off;
    313 
    314 	while (size) {
    315 		if (fp->off < 0 || fp->off >= fp->size)
    316 			break;
    317 		bno = fp->off / ISO_DEFAULT_BLOCK_SIZE + fp->bno;
    318 		if (fp->off & (ISO_DEFAULT_BLOCK_SIZE - 1)
    319 		    || size < ISO_DEFAULT_BLOCK_SIZE)
    320 			dp = buf;
    321 		else
    322 			dp = start;
    323 #if !defined(LIBSA_NO_TWIDDLE)
    324 		twiddle();
    325 #endif
    326 		rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ, cdb2devb(bno),
    327 		                            ISO_DEFAULT_BLOCK_SIZE, dp, &nread);
    328 		if (rc)
    329 			return rc;
    330 		if (nread != ISO_DEFAULT_BLOCK_SIZE)
    331 			return EIO;
    332 		if (dp == buf) {
    333 			off = fp->off & (ISO_DEFAULT_BLOCK_SIZE - 1);
    334 			if (nread > off + size)
    335 				nread = off + size;
    336 			nread -= off;
    337 			memcpy(start, buf + off, nread);
    338 			start = (char *)start + nread;
    339 			fp->off += nread;
    340 			size -= nread;
    341 		} else {
    342 			start = (char *)start + ISO_DEFAULT_BLOCK_SIZE;
    343 			fp->off += ISO_DEFAULT_BLOCK_SIZE;
    344 			size -= ISO_DEFAULT_BLOCK_SIZE;
    345 		}
    346 	}
    347 	if (resid)
    348 		*resid = size;
    349 	return rc;
    350 }
    351 
    352 #if !defined(LIBSA_NO_FS_WRITE)
    353 int
    354 cd9660_write(struct open_file *f, void *start, size_t size, size_t *resid)
    355 {
    356 
    357 	return EROFS;
    358 }
    359 #endif /* !defined(LIBSA_NO_FS_WRITE) */
    360 
    361 #if !defined(LIBSA_NO_FS_SEEK)
    362 off_t
    363 cd9660_seek(struct open_file *f, off_t offset, int where)
    364 {
    365 	struct file *fp = (struct file *)f->f_fsdata;
    366 
    367 	switch (where) {
    368 	case SEEK_SET:
    369 		fp->off = offset;
    370 		break;
    371 	case SEEK_CUR:
    372 		fp->off += offset;
    373 		break;
    374 	case SEEK_END:
    375 		fp->off = fp->size - offset;
    376 		break;
    377 	default:
    378 		return -1;
    379 	}
    380 	return fp->off;
    381 }
    382 #endif /* !defined(LIBSA_NO_FS_SEEK) */
    383 
    384 int
    385 cd9660_stat(struct open_file *f, struct stat *sb)
    386 {
    387 	struct file *fp = (struct file *)f->f_fsdata;
    388 
    389 	/* only importatn stuff */
    390 	sb->st_mode = S_IFREG | S_IRUSR | S_IRGRP | S_IROTH;
    391 	sb->st_uid = sb->st_gid = 0;
    392 	sb->st_size = fp->size;
    393 	return 0;
    394 }
    395