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cd9660.c revision 1.27
      1 /*	$NetBSD: cd9660.c,v 1.27 2011/06/16 13:27:58 joerg 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 __compactcall 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 	while (*path) {
    201 		/*
    202 		 * Remove extra separators
    203 		 */
    204 		while (*path == '/')
    205 			path++;
    206 
    207 		if ((char *)pp >= (char *)buf + psize)
    208 			break;
    209 		if (isonum_722(pp->parent) != parent)
    210 			break;
    211 		if (!pnmatch(path, pp)) {
    212 			pp = (struct ptable_ent *)((char *)pp + PTSIZE(pp));
    213 			ent++;
    214 			continue;
    215 		}
    216 		path += isonum_711(pp->namlen) + 1;
    217 		parent = ent;
    218 		bno = isonum_732(pp->block) + isonum_711(pp->extlen);
    219 		while ((char *)pp < (char *)buf + psize) {
    220 			if (isonum_722(pp->parent) == parent)
    221 				break;
    222 			pp = (struct ptable_ent *)((char *)pp + PTSIZE(pp));
    223 			ent++;
    224 		}
    225 	}
    226 
    227 	/*
    228 	 * Now bno has the start of the directory that supposedly
    229 	 * contains the file
    230 	 */
    231 	bno--;
    232 	dsize = 1;		/* Something stupid, but > 0 XXX */
    233 	for (psize = 0; psize < dsize;) {
    234 		if (!(psize % ISO_DEFAULT_BLOCK_SIZE)) {
    235 			bno++;
    236 #if !defined(LIBSA_NO_TWIDDLE)
    237 			twiddle();
    238 #endif
    239 			rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
    240 			                           cdb2devb(bno),
    241 			                           ISO_DEFAULT_BLOCK_SIZE,
    242 			                           buf, &nread);
    243 			if (rc)
    244 				goto out;
    245 			if (nread != ISO_DEFAULT_BLOCK_SIZE) {
    246 				rc = EIO;
    247 				goto out;
    248 			}
    249 			dp = (struct iso_directory_record *)buf;
    250 		}
    251 		if (!isonum_711(dp->length)) {
    252 			if ((void *)dp == buf)
    253 				psize += ISO_DEFAULT_BLOCK_SIZE;
    254 			else
    255 				psize = roundup(psize, ISO_DEFAULT_BLOCK_SIZE);
    256 			continue;
    257 		}
    258 		if (dsize == 1)
    259 			dsize = isonum_733(dp->size);
    260 		if (dirmatch(path, dp))
    261 			break;
    262 		psize += isonum_711(dp->length);
    263 		dp = (struct iso_directory_record *)
    264 			((char *)dp + isonum_711(dp->length));
    265 	}
    266 
    267 	if (psize >= dsize) {
    268 		rc = ENOENT;
    269 		goto out;
    270 	}
    271 
    272 	/* allocate file system specific data structure */
    273 	fp = alloc(sizeof(struct file));
    274 	memset(fp, 0, sizeof(struct file));
    275 	f->f_fsdata = (void *)fp;
    276 
    277 	fp->off = 0;
    278 	fp->bno = isonum_733(dp->extent);
    279 	fp->size = isonum_733(dp->size);
    280 	dealloc(buf, buf_size);
    281 	fsmod = "cd9660";
    282 
    283 	return 0;
    284 
    285 out:
    286 	if (fp)
    287 		dealloc(fp, sizeof(struct file));
    288 	dealloc(buf, buf_size);
    289 
    290 	return rc;
    291 }
    292 
    293 #if !defined(LIBSA_NO_FS_CLOSE)
    294 __compactcall int
    295 cd9660_close(struct open_file *f)
    296 {
    297 	struct file *fp = (struct file *)f->f_fsdata;
    298 
    299 	f->f_fsdata = 0;
    300 	dealloc(fp, sizeof *fp);
    301 
    302 	return 0;
    303 }
    304 #endif /* !defined(LIBSA_NO_FS_CLOSE) */
    305 
    306 __compactcall int
    307 cd9660_read(struct open_file *f, void *start, size_t size, size_t *resid)
    308 {
    309 	struct file *fp = (struct file *)f->f_fsdata;
    310 	int rc = 0;
    311 	daddr_t bno;
    312 	char buf[ISO_DEFAULT_BLOCK_SIZE];
    313 	char *dp;
    314 	size_t nread, off;
    315 
    316 	while (size) {
    317 		if (fp->off < 0 || fp->off >= fp->size)
    318 			break;
    319 		bno = fp->off / ISO_DEFAULT_BLOCK_SIZE + fp->bno;
    320 		if (fp->off & (ISO_DEFAULT_BLOCK_SIZE - 1)
    321 		    || size < ISO_DEFAULT_BLOCK_SIZE)
    322 			dp = buf;
    323 		else
    324 			dp = start;
    325 #if !defined(LIBSA_NO_TWIDDLE)
    326 		twiddle();
    327 #endif
    328 		rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ, cdb2devb(bno),
    329 		                            ISO_DEFAULT_BLOCK_SIZE, dp, &nread);
    330 		if (rc)
    331 			return rc;
    332 		if (nread != ISO_DEFAULT_BLOCK_SIZE)
    333 			return EIO;
    334 		if (dp == buf) {
    335 			off = fp->off & (ISO_DEFAULT_BLOCK_SIZE - 1);
    336 			if (nread > off + size)
    337 				nread = off + size;
    338 			nread -= off;
    339 			memcpy(start, buf + off, nread);
    340 			start = (char *)start + nread;
    341 			fp->off += nread;
    342 			size -= nread;
    343 		} else {
    344 			start = (char *)start + ISO_DEFAULT_BLOCK_SIZE;
    345 			fp->off += ISO_DEFAULT_BLOCK_SIZE;
    346 			size -= ISO_DEFAULT_BLOCK_SIZE;
    347 		}
    348 	}
    349 	if(fp->off > fp->size)
    350 		size += fp->off - fp->size;
    351 	if (resid)
    352 		*resid = size;
    353 	return rc;
    354 }
    355 
    356 #if !defined(LIBSA_NO_FS_WRITE)
    357 __compactcall int
    358 cd9660_write(struct open_file *f, void *start, size_t size, size_t *resid)
    359 {
    360 
    361 	return EROFS;
    362 }
    363 #endif /* !defined(LIBSA_NO_FS_WRITE) */
    364 
    365 #if !defined(LIBSA_NO_FS_SEEK)
    366 __compactcall off_t
    367 cd9660_seek(struct open_file *f, off_t offset, int where)
    368 {
    369 	struct file *fp = (struct file *)f->f_fsdata;
    370 
    371 	switch (where) {
    372 	case SEEK_SET:
    373 		fp->off = offset;
    374 		break;
    375 	case SEEK_CUR:
    376 		fp->off += offset;
    377 		break;
    378 	case SEEK_END:
    379 		fp->off = fp->size - offset;
    380 		break;
    381 	default:
    382 		return -1;
    383 	}
    384 	return fp->off;
    385 }
    386 #endif /* !defined(LIBSA_NO_FS_SEEK) */
    387 
    388 __compactcall int
    389 cd9660_stat(struct open_file *f, struct stat *sb)
    390 {
    391 	struct file *fp = (struct file *)f->f_fsdata;
    392 
    393 	/* only importatn stuff */
    394 	sb->st_mode = S_IFREG | S_IRUSR | S_IRGRP | S_IROTH;
    395 	sb->st_uid = sb->st_gid = 0;
    396 	sb->st_size = fp->size;
    397 	return 0;
    398 }
    399