xref: /netbsd-src/sys/lib/libsa/cd9660.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: cd9660.c,v 1.5 1997/06/26 19:11:33 drochner 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 <isofs/cd9660/iso.h>
47 
48 #include "stand.h"
49 #include "cd9660.h"
50 
51 struct file {
52 	off_t off;			/* Current offset within file */
53 	daddr_t bno;			/* Starting block number  */
54 	off_t size;			/* Size of file */
55 };
56 
57 struct ptable_ent {
58 	char namlen	[ISODCL( 1, 1)];	/* 711 */
59 	char extlen	[ISODCL( 2, 2)];	/* 711 */
60 	char block	[ISODCL( 3, 6)];	/* 732 */
61 	char parent	[ISODCL( 7, 8)];	/* 722 */
62 	char name	[1];
63 };
64 #define	PTFIXSZ		8
65 #define	PTSIZE(pp)	roundup(PTFIXSZ + isonum_711((pp)->namlen), 2)
66 
67 #define	cdb2devb(bno)	((bno) * ISO_DEFAULT_BLOCK_SIZE / DEV_BSIZE)
68 
69 static int
70 toupper(c)
71 	int c;
72 {
73 	return c >= 'a' && c <= 'z' ? c - 'a' + 'A' : c;
74 }
75 
76 static int
77 pnmatch(path, pp)
78 	char *path;
79 	struct ptable_ent *pp;
80 {
81 	char *cp;
82 	int i;
83 
84 	cp = pp->name;
85 	for (i = isonum_711(pp->namlen); --i >= 0; path++, cp++) {
86 		if (toupper(*path) == *cp)
87 			continue;
88 		return 0;
89 	}
90 	if (*path != '/')
91 		return 0;
92 	return 1;
93 }
94 
95 static int
96 dirmatch(path, dp)
97 	char *path;
98 	struct iso_directory_record *dp;
99 {
100 	char *cp;
101 	int i;
102 
103 	/* This needs to be a regular file */
104 	if (dp->flags[0] & 6)
105 		return 0;
106 
107 	cp = dp->name;
108 	for (i = isonum_711(dp->name_len); --i >= 0; path++, cp++) {
109 		if (!*path)
110 			break;
111 		if (toupper(*path) == *cp)
112 			continue;
113 		return 0;
114 	}
115 	if (*path)
116 		return 0;
117 	/*
118 	 * Allow stripping of trailing dots and the version number.
119 	 * Note that this will find the first instead of the last version
120 	 * of a file.
121 	 */
122 	if (i >= 0 && (*cp == ';' || *cp == '.')) {
123 		/* This is to prevent matching of numeric extensions */
124 		if (*cp == '.' && cp[1] != ';')
125 			return 0;
126 		while (--i >= 0)
127 			if (*++cp != ';' && (*cp < '0' || *cp > '9'))
128 				return 0;
129 	}
130 	return 1;
131 }
132 
133 int
134 cd9660_open(path, f)
135 	char *path;
136 	struct open_file *f;
137 {
138 	struct file *fp = 0;
139 	void *buf;
140 	struct iso_primary_descriptor *vd;
141 	size_t buf_size, read, psize, dsize;
142 	daddr_t bno;
143 	int parent, ent;
144 	struct ptable_ent *pp;
145 	struct iso_directory_record *dp = 0;
146 	int rc;
147 
148 	/* First find the volume descriptor */
149 	buf = alloc(buf_size = ISO_DEFAULT_BLOCK_SIZE);
150 	vd = buf;
151 	for (bno = 16;; bno++) {
152 		twiddle();
153 		rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno),
154 					   ISO_DEFAULT_BLOCK_SIZE, buf, &read);
155 		if (rc)
156 			goto out;
157 		if (read != ISO_DEFAULT_BLOCK_SIZE) {
158 			rc = EIO;
159 			goto out;
160 		}
161 		rc = EINVAL;
162 		if (bcmp(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 	twiddle();
182 	rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno),
183 				   buf_size, buf, &read);
184 	if (rc)
185 		goto out;
186 	if (read != buf_size) {
187 		rc = EIO;
188 		goto out;
189 	}
190 
191 	parent = 1;
192 	pp = (struct ptable_ent *)buf;
193 	ent = 1;
194 	bno = isonum_732(pp->block) + isonum_711(pp->extlen);
195 
196 	rc = ENOENT;
197 	while (*path) {
198 		if ((void *)pp >= buf + psize)
199 			break;
200 		if (isonum_722(pp->parent) != parent)
201 			break;
202 		if (!pnmatch(path, pp)) {
203 			pp = (struct ptable_ent *)((void *)pp + PTSIZE(pp));
204 			ent++;
205 			continue;
206 		}
207 		path += isonum_711(pp->namlen) + 1;
208 		parent = ent;
209 		bno = isonum_732(pp->block) + isonum_711(pp->extlen);
210 		while ((void *)pp < buf + psize) {
211 			if (isonum_722(pp->parent) == parent)
212 				break;
213 			pp = (struct ptable_ent *)((void *)pp + PTSIZE(pp));
214 			ent++;
215 		}
216 	}
217 
218 	/* Now bno has the start of the directory that supposedly contains the file */
219 	bno--;
220 	dsize = 1;		/* Something stupid, but > 0			XXX */
221 	for (psize = 0; psize < dsize;) {
222 		if (!(psize % ISO_DEFAULT_BLOCK_SIZE)) {
223 			bno++;
224 			twiddle();
225 			rc = f->f_dev->dv_strategy(f->f_devdata, F_READ,
226 						   cdb2devb(bno),
227 						   ISO_DEFAULT_BLOCK_SIZE,
228 						   buf, &read);
229 			if (rc)
230 				goto out;
231 			if (read != ISO_DEFAULT_BLOCK_SIZE) {
232 				rc = EIO;
233 				goto out;
234 			}
235 			dp = (struct iso_directory_record *)buf;
236 		}
237 		if (!isonum_711(dp->length)) {
238 			if ((void *)dp == buf)
239 				psize += ISO_DEFAULT_BLOCK_SIZE;
240 			else
241 				psize = roundup(psize, ISO_DEFAULT_BLOCK_SIZE);
242 			continue;
243 		}
244 		if (dsize == 1)
245 			dsize = isonum_733(dp->size);
246 		if (dirmatch(path, dp))
247 			break;
248 		psize += isonum_711(dp->length);
249 		dp = (struct iso_directory_record *)((void *)dp + isonum_711(dp->length));
250 	}
251 
252 	if (psize >= dsize) {
253 		rc = ENOENT;
254 		goto out;
255 	}
256 
257 	/* allocate file system specific data structure */
258 	fp = alloc(sizeof(struct file));
259 	bzero(fp, sizeof(struct file));
260 	f->f_fsdata = (void *)fp;
261 
262 	fp->off = 0;
263 	fp->bno = isonum_733(dp->extent);
264 	fp->size = isonum_733(dp->size);
265 	free(buf, buf_size);
266 
267 	return 0;
268 
269 out:
270 	if (fp)
271 		free(fp, sizeof(struct file));
272 	free(buf, buf_size);
273 
274 	return rc;
275 }
276 
277 int
278 cd9660_close(f)
279 	struct open_file *f;
280 {
281 	struct file *fp = (struct file *)f->f_fsdata;
282 
283 	f->f_fsdata = 0;
284 	free(fp, sizeof *fp);
285 
286 	return 0;
287 }
288 
289 int
290 cd9660_read(f, start, size, resid)
291 	struct open_file *f;
292 	void *start;
293 	size_t size;
294 	size_t *resid;
295 {
296 	struct file *fp = (struct file *)f->f_fsdata;
297 	int rc = 0;
298 	daddr_t bno;
299 	char buf[ISO_DEFAULT_BLOCK_SIZE];
300 	char *dp;
301 	size_t read, off;
302 
303 	while (size) {
304 		if (fp->off < 0 || fp->off >= fp->size)
305 			break;
306 		bno = fp->off / ISO_DEFAULT_BLOCK_SIZE + fp->bno;
307 		if (fp->off & (ISO_DEFAULT_BLOCK_SIZE - 1)
308 		    || size < ISO_DEFAULT_BLOCK_SIZE)
309 			dp = buf;
310 		else
311 			dp = start;
312 		twiddle();
313 		rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno),
314 					   ISO_DEFAULT_BLOCK_SIZE, dp, &read);
315 		if (rc)
316 			return rc;
317 		if (read != ISO_DEFAULT_BLOCK_SIZE)
318 			return EIO;
319 		if (dp == buf) {
320 			off = fp->off & (ISO_DEFAULT_BLOCK_SIZE - 1);
321 			if (read > off + size)
322 				read = off + size;
323 			read -= off;
324 			bcopy(buf + off, start, read);
325 			start += read;
326 			fp->off += read;
327 			size -= read;
328 		} else {
329 			start += ISO_DEFAULT_BLOCK_SIZE;
330 			fp->off += ISO_DEFAULT_BLOCK_SIZE;
331 			size -= ISO_DEFAULT_BLOCK_SIZE;
332 		}
333 	}
334 	if (resid)
335 		*resid = size;
336 	return rc;
337 }
338 
339 int
340 cd9660_write(f, start, size, resid)
341 	struct open_file *f;
342 	void *start;
343 	size_t size;
344 	size_t *resid;
345 {
346 	return EROFS;
347 }
348 
349 off_t
350 cd9660_seek(f, offset, where)
351 	struct open_file *f;
352 	off_t offset;
353 	int where;
354 {
355 	struct file *fp = (struct file *)f->f_fsdata;
356 
357 	switch (where) {
358 	case SEEK_SET:
359 		fp->off = offset;
360 		break;
361 	case SEEK_CUR:
362 		fp->off += offset;
363 		break;
364 	case SEEK_END:
365 		fp->off = fp->size - offset;
366 		break;
367 	default:
368 		return -1;
369 	}
370 	return fp->off;
371 }
372 
373 int
374 cd9660_stat(f, sb)
375 	struct open_file *f;
376 	struct stat *sb;
377 {
378 	struct file *fp = (struct file *)f->f_fsdata;
379 
380 	/* only importatn stuff */
381 	sb->st_mode = S_IFREG | S_IRUSR | S_IRGRP | S_IROTH;
382 	sb->st_uid = sb->st_gid = 0;
383 	sb->st_size = fp->size;
384 	return 0;
385 }
386