xref: /netbsd-src/sys/lib/libsa/cd9660.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: cd9660.c,v 1.25 2010/03/22 16:57:54 jakllsch 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 	fsmod = "cd9660";
281 
282 	return 0;
283 
284 out:
285 	if (fp)
286 		dealloc(fp, sizeof(struct file));
287 	dealloc(buf, buf_size);
288 
289 	return rc;
290 }
291 
292 #if !defined(LIBSA_NO_FS_CLOSE)
293 int
294 cd9660_close(struct open_file *f)
295 {
296 	struct file *fp = (struct file *)f->f_fsdata;
297 
298 	f->f_fsdata = 0;
299 	dealloc(fp, sizeof *fp);
300 
301 	return 0;
302 }
303 #endif /* !defined(LIBSA_NO_FS_CLOSE) */
304 
305 int
306 cd9660_read(struct open_file *f, void *start, size_t size, size_t *resid)
307 {
308 	struct file *fp = (struct file *)f->f_fsdata;
309 	int rc = 0;
310 	daddr_t bno;
311 	char buf[ISO_DEFAULT_BLOCK_SIZE];
312 	char *dp;
313 	size_t nread, off;
314 
315 	while (size) {
316 		if (fp->off < 0 || fp->off >= fp->size)
317 			break;
318 		bno = fp->off / ISO_DEFAULT_BLOCK_SIZE + fp->bno;
319 		if (fp->off & (ISO_DEFAULT_BLOCK_SIZE - 1)
320 		    || size < ISO_DEFAULT_BLOCK_SIZE)
321 			dp = buf;
322 		else
323 			dp = start;
324 #if !defined(LIBSA_NO_TWIDDLE)
325 		twiddle();
326 #endif
327 		rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ, cdb2devb(bno),
328 		                            ISO_DEFAULT_BLOCK_SIZE, dp, &nread);
329 		if (rc)
330 			return rc;
331 		if (nread != ISO_DEFAULT_BLOCK_SIZE)
332 			return EIO;
333 		if (dp == buf) {
334 			off = fp->off & (ISO_DEFAULT_BLOCK_SIZE - 1);
335 			if (nread > off + size)
336 				nread = off + size;
337 			nread -= off;
338 			memcpy(start, buf + off, nread);
339 			start = (char *)start + nread;
340 			fp->off += nread;
341 			size -= nread;
342 		} else {
343 			start = (char *)start + ISO_DEFAULT_BLOCK_SIZE;
344 			fp->off += ISO_DEFAULT_BLOCK_SIZE;
345 			size -= ISO_DEFAULT_BLOCK_SIZE;
346 		}
347 	}
348 	if(fp->off > fp->size)
349 		size += fp->off - fp->size;
350 	if (resid)
351 		*resid = size;
352 	return rc;
353 }
354 
355 #if !defined(LIBSA_NO_FS_WRITE)
356 int
357 cd9660_write(struct open_file *f, void *start, size_t size, size_t *resid)
358 {
359 
360 	return EROFS;
361 }
362 #endif /* !defined(LIBSA_NO_FS_WRITE) */
363 
364 #if !defined(LIBSA_NO_FS_SEEK)
365 off_t
366 cd9660_seek(struct open_file *f, off_t offset, int where)
367 {
368 	struct file *fp = (struct file *)f->f_fsdata;
369 
370 	switch (where) {
371 	case SEEK_SET:
372 		fp->off = offset;
373 		break;
374 	case SEEK_CUR:
375 		fp->off += offset;
376 		break;
377 	case SEEK_END:
378 		fp->off = fp->size - offset;
379 		break;
380 	default:
381 		return -1;
382 	}
383 	return fp->off;
384 }
385 #endif /* !defined(LIBSA_NO_FS_SEEK) */
386 
387 int
388 cd9660_stat(struct open_file *f, struct stat *sb)
389 {
390 	struct file *fp = (struct file *)f->f_fsdata;
391 
392 	/* only importatn stuff */
393 	sb->st_mode = S_IFREG | S_IRUSR | S_IRGRP | S_IROTH;
394 	sb->st_uid = sb->st_gid = 0;
395 	sb->st_size = fp->size;
396 	return 0;
397 }
398