xref: /netbsd-src/sys/lib/libsa/cd9660.c (revision e5548b402ae4c44fb816de42c7bba9581ce23ef5)
1 /*	$NetBSD: cd9660.c,v 1.19 2005/12/11 12:24:46 christos 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 		free(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 ((caddr_t)pp >= (caddr_t)buf + psize)
207 			break;
208 		if (isonum_722(pp->parent) != parent)
209 			break;
210 		if (!pnmatch(path, pp)) {
211 			pp = (struct ptable_ent *)((caddr_t)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 ((caddr_t)pp < (caddr_t)buf + psize) {
219 			if (isonum_722(pp->parent) == parent)
220 				break;
221 			pp = (struct ptable_ent *)((caddr_t)pp + PTSIZE(pp));
222 			ent++;
223 		}
224 	}
225 
226 	/* Now bno has the start of the directory that supposedly contains the file */
227 	bno--;
228 	dsize = 1;		/* Something stupid, but > 0			XXX */
229 	for (psize = 0; psize < dsize;) {
230 		if (!(psize % ISO_DEFAULT_BLOCK_SIZE)) {
231 			bno++;
232 #if !defined(LIBSA_NO_TWIDDLE)
233 			twiddle();
234 #endif
235 			rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ,
236 						   cdb2devb(bno),
237 						   ISO_DEFAULT_BLOCK_SIZE,
238 						   buf, &nread);
239 			if (rc)
240 				goto out;
241 			if (nread != ISO_DEFAULT_BLOCK_SIZE) {
242 				rc = EIO;
243 				goto out;
244 			}
245 			dp = (struct iso_directory_record *)buf;
246 		}
247 		if (!isonum_711(dp->length)) {
248 			if ((void *)dp == buf)
249 				psize += ISO_DEFAULT_BLOCK_SIZE;
250 			else
251 				psize = roundup(psize, ISO_DEFAULT_BLOCK_SIZE);
252 			continue;
253 		}
254 		if (dsize == 1)
255 			dsize = isonum_733(dp->size);
256 		if (dirmatch(path, dp))
257 			break;
258 		psize += isonum_711(dp->length);
259 		dp = (struct iso_directory_record *)((caddr_t)dp + isonum_711(dp->length));
260 	}
261 
262 	if (psize >= dsize) {
263 		rc = ENOENT;
264 		goto out;
265 	}
266 
267 	/* allocate file system specific data structure */
268 	fp = alloc(sizeof(struct file));
269 	memset(fp, 0, sizeof(struct file));
270 	f->f_fsdata = (void *)fp;
271 
272 	fp->off = 0;
273 	fp->bno = isonum_733(dp->extent);
274 	fp->size = isonum_733(dp->size);
275 	free(buf, buf_size);
276 
277 	return 0;
278 
279 out:
280 	if (fp)
281 		free(fp, sizeof(struct file));
282 	free(buf, buf_size);
283 
284 	return rc;
285 }
286 
287 #if !defined(LIBSA_NO_FS_CLOSE)
288 int
289 cd9660_close(struct open_file *f)
290 {
291 	struct file *fp = (struct file *)f->f_fsdata;
292 
293 	f->f_fsdata = 0;
294 	free(fp, sizeof *fp);
295 
296 	return 0;
297 }
298 #endif /* !defined(LIBSA_NO_FS_CLOSE) */
299 
300 int
301 cd9660_read(struct open_file *f, void *start, size_t size, size_t *resid)
302 {
303 	struct file *fp = (struct file *)f->f_fsdata;
304 	int rc = 0;
305 	daddr_t bno;
306 	char buf[ISO_DEFAULT_BLOCK_SIZE];
307 	char *dp;
308 	size_t nread, off;
309 
310 	while (size) {
311 		if (fp->off < 0 || fp->off >= fp->size)
312 			break;
313 		bno = fp->off / ISO_DEFAULT_BLOCK_SIZE + fp->bno;
314 		if (fp->off & (ISO_DEFAULT_BLOCK_SIZE - 1)
315 		    || size < ISO_DEFAULT_BLOCK_SIZE)
316 			dp = buf;
317 		else
318 			dp = start;
319 #if !defined(LIBSA_NO_TWIDDLE)
320 		twiddle();
321 #endif
322 		rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ, cdb2devb(bno),
323 					   ISO_DEFAULT_BLOCK_SIZE, dp, &nread);
324 		if (rc)
325 			return rc;
326 		if (nread != ISO_DEFAULT_BLOCK_SIZE)
327 			return EIO;
328 		if (dp == buf) {
329 			off = fp->off & (ISO_DEFAULT_BLOCK_SIZE - 1);
330 			if (nread > off + size)
331 				nread = off + size;
332 			nread -= off;
333 			memcpy(start, buf + off, nread);
334 			start = (caddr_t)start + nread;
335 			fp->off += nread;
336 			size -= nread;
337 		} else {
338 			start = (caddr_t)start + ISO_DEFAULT_BLOCK_SIZE;
339 			fp->off += ISO_DEFAULT_BLOCK_SIZE;
340 			size -= ISO_DEFAULT_BLOCK_SIZE;
341 		}
342 	}
343 	if (resid)
344 		*resid = size;
345 	return rc;
346 }
347 
348 #if !defined(LIBSA_NO_FS_WRITE)
349 int
350 cd9660_write(struct open_file *f, void *start, size_t size, size_t *resid)
351 {
352 	return EROFS;
353 }
354 #endif /* !defined(LIBSA_NO_FS_WRITE) */
355 
356 #if !defined(LIBSA_NO_FS_SEEK)
357 off_t
358 cd9660_seek(struct open_file *f, off_t offset, int where)
359 {
360 	struct file *fp = (struct file *)f->f_fsdata;
361 
362 	switch (where) {
363 	case SEEK_SET:
364 		fp->off = offset;
365 		break;
366 	case SEEK_CUR:
367 		fp->off += offset;
368 		break;
369 	case SEEK_END:
370 		fp->off = fp->size - offset;
371 		break;
372 	default:
373 		return -1;
374 	}
375 	return fp->off;
376 }
377 #endif /* !defined(LIBSA_NO_FS_SEEK) */
378 
379 int
380 cd9660_stat(struct open_file *f, struct stat *sb)
381 {
382 	struct file *fp = (struct file *)f->f_fsdata;
383 
384 	/* only importatn stuff */
385 	sb->st_mode = S_IFREG | S_IRUSR | S_IRGRP | S_IROTH;
386 	sb->st_uid = sb->st_gid = 0;
387 	sb->st_size = fp->size;
388 	return 0;
389 }
390