xref: /netbsd-src/sys/lib/libsa/cd9660.c (revision d0fed6c87ddc40a8bffa6f99e7433ddfc864dd83)
1 /*	$NetBSD: cd9660.c,v 1.3 1997/01/24 00:53:40 cgd 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 #include <lib/libkern/libkern.h>
42 #include <isofs/cd9660/iso.h>
43 
44 #include "stand.h"
45 #include "cd9660.h"
46 
47 struct file {
48 	off_t off;			/* Current offset within file */
49 	daddr_t bno;			/* Starting block number  */
50 	off_t size;			/* Size of file */
51 };
52 
53 struct ptable_ent {
54 	char namlen	[ISODCL( 1, 1)];	/* 711 */
55 	char extlen	[ISODCL( 2, 2)];	/* 711 */
56 	char block	[ISODCL( 3, 6)];	/* 732 */
57 	char parent	[ISODCL( 7, 8)];	/* 722 */
58 	char name	[1];
59 };
60 #define	PTFIXSZ		8
61 #define	PTSIZE(pp)	roundup(PTFIXSZ + isonum_711((pp)->namlen), 2)
62 
63 #define	cdb2devb(bno)	((bno) * ISO_DEFAULT_BLOCK_SIZE / DEV_BSIZE)
64 
65 static int
66 toupper(c)
67 	int c;
68 {
69 	return c >= 'a' && c <= 'z' ? c - 'a' + 'A' : c;
70 }
71 
72 static int
73 pnmatch(path, pp)
74 	char *path;
75 	struct ptable_ent *pp;
76 {
77 	char *cp;
78 	int i;
79 
80 	cp = pp->name;
81 	for (i = isonum_711(pp->namlen); --i >= 0; path++, cp++) {
82 		if (toupper(*path) == *cp)
83 			continue;
84 		return 0;
85 	}
86 	if (*path != '/')
87 		return 0;
88 	return 1;
89 }
90 
91 static int
92 dirmatch(path, dp)
93 	char *path;
94 	struct iso_directory_record *dp;
95 {
96 	char *cp;
97 	int i;
98 
99 	/* This needs to be a regular file */
100 	if (dp->flags[0] & 6)
101 		return 0;
102 
103 	cp = dp->name;
104 	for (i = isonum_711(dp->name_len); --i >= 0; path++, cp++) {
105 		if (!*path)
106 			break;
107 		if (toupper(*path) == *cp)
108 			continue;
109 		return 0;
110 	}
111 	if (*path)
112 		return 0;
113 	/*
114 	 * Allow stripping of trailing dots and the version number.
115 	 * Note that this will find the first instead of the last version
116 	 * of a file.
117 	 */
118 	if (i >= 0 && (*cp == ';' || *cp == '.')) {
119 		/* This is to prevent matching of numeric extensions */
120 		if (*cp == '.' && cp[1] != ';')
121 			return 0;
122 		while (--i >= 0)
123 			if (*++cp != ';' && (*cp < '0' || *cp > '9'))
124 				return 0;
125 	}
126 	return 1;
127 }
128 
129 int
130 cd9660_open(path, f)
131 	char *path;
132 	struct open_file *f;
133 {
134 	struct file *fp = 0;
135 	void *buf;
136 	struct iso_primary_descriptor *vd;
137 	size_t buf_size, read, psize, dsize;
138 	daddr_t bno;
139 	int parent, ent;
140 	struct ptable_ent *pp;
141 	struct iso_directory_record *dp;
142 	int rc;
143 
144 	/* First find the volume descriptor */
145 	buf = alloc(buf_size = ISO_DEFAULT_BLOCK_SIZE);
146 	vd = buf;
147 	for (bno = 16;; bno++) {
148 		twiddle();
149 		rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno),
150 					   ISO_DEFAULT_BLOCK_SIZE, buf, &read);
151 		if (rc)
152 			goto out;
153 		if (read != ISO_DEFAULT_BLOCK_SIZE) {
154 			rc = EIO;
155 			goto out;
156 		}
157 		rc = EINVAL;
158 		if (bcmp(vd->id, ISO_STANDARD_ID, sizeof vd->id) != 0)
159 			goto out;
160 		if (isonum_711(vd->type) == ISO_VD_END)
161 			goto out;
162 		if (isonum_711(vd->type) == ISO_VD_PRIMARY)
163 			break;
164 	}
165 	if (isonum_723(vd->logical_block_size) != ISO_DEFAULT_BLOCK_SIZE)
166 		goto out;
167 
168 	/* Now get the path table and lookup the directory of the file */
169 	bno = isonum_732(vd->type_m_path_table);
170 	psize = isonum_733(vd->path_table_size);
171 
172 	if (psize > ISO_DEFAULT_BLOCK_SIZE) {
173 		free(buf, ISO_DEFAULT_BLOCK_SIZE);
174 		buf = alloc(buf_size = roundup(psize, ISO_DEFAULT_BLOCK_SIZE));
175 	}
176 
177 	twiddle();
178 	rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno),
179 				   buf_size, buf, &read);
180 	if (rc)
181 		goto out;
182 	if (read != buf_size) {
183 		rc = EIO;
184 		goto out;
185 	}
186 
187 	parent = 1;
188 	pp = (struct ptable_ent *)buf;
189 	ent = 1;
190 	bno = isonum_732(pp->block) + isonum_711(pp->extlen);
191 
192 	rc = ENOENT;
193 	while (*path) {
194 		if ((void *)pp >= buf + psize)
195 			break;
196 		if (isonum_722(pp->parent) != parent)
197 			break;
198 		if (!pnmatch(path, pp)) {
199 			pp = (struct ptable_ent *)((void *)pp + PTSIZE(pp));
200 			ent++;
201 			continue;
202 		}
203 		path += isonum_711(pp->namlen) + 1;
204 		parent = ent;
205 		bno = isonum_732(pp->block) + isonum_711(pp->extlen);
206 		while ((void *)pp < buf + psize) {
207 			if (isonum_722(pp->parent) == parent)
208 				break;
209 			pp = (struct ptable_ent *)((void *)pp + PTSIZE(pp));
210 			ent++;
211 		}
212 	}
213 
214 	/* Now bno has the start of the directory that supposedly contains the file */
215 	bno--;
216 	dsize = 1;		/* Something stupid, but > 0			XXX */
217 	for (psize = 0; psize < dsize;) {
218 		if (!(psize % ISO_DEFAULT_BLOCK_SIZE)) {
219 			bno++;
220 			twiddle();
221 			rc = f->f_dev->dv_strategy(f->f_devdata, F_READ,
222 						   cdb2devb(bno),
223 						   ISO_DEFAULT_BLOCK_SIZE,
224 						   buf, &read);
225 			if (rc)
226 				goto out;
227 			if (read != ISO_DEFAULT_BLOCK_SIZE) {
228 				rc = EIO;
229 				goto out;
230 			}
231 			dp = (struct iso_directory_record *)buf;
232 		}
233 		if (!isonum_711(dp->length)) {
234 			if ((void *)dp == buf)
235 				psize += ISO_DEFAULT_BLOCK_SIZE;
236 			else
237 				psize = roundup(psize, ISO_DEFAULT_BLOCK_SIZE);
238 			continue;
239 		}
240 		if (dsize == 1)
241 			dsize = isonum_733(dp->size);
242 		if (dirmatch(path, dp))
243 			break;
244 		psize += isonum_711(dp->length);
245 		dp = (struct iso_directory_record *)((void *)dp + isonum_711(dp->length));
246 	}
247 
248 	if (psize >= dsize) {
249 		rc = ENOENT;
250 		goto out;
251 	}
252 
253 	/* allocate file system specific data structure */
254 	fp = alloc(sizeof(struct file));
255 	bzero(fp, sizeof(struct file));
256 	f->f_fsdata = (void *)fp;
257 
258 	fp->off = 0;
259 	fp->bno = isonum_733(dp->extent);
260 	fp->size = isonum_733(dp->size);
261 	free(buf, buf_size);
262 
263 	return 0;
264 
265 out:
266 	if (fp)
267 		free(fp, sizeof(struct file));
268 	free(buf, buf_size);
269 
270 	return rc;
271 }
272 
273 int
274 cd9660_close(f)
275 	struct open_file *f;
276 {
277 	struct file *fp = (struct file *)f->f_fsdata;
278 
279 	f->f_fsdata = 0;
280 	free(fp, sizeof *fp);
281 
282 	return 0;
283 }
284 
285 int
286 cd9660_read(f, start, size, resid)
287 	struct open_file *f;
288 	void *start;
289 	size_t size;
290 	size_t *resid;
291 {
292 	struct file *fp = (struct file *)f->f_fsdata;
293 	int rc = 0;
294 	daddr_t bno;
295 	char buf[ISO_DEFAULT_BLOCK_SIZE];
296 	char *dp;
297 	size_t read, off;
298 
299 	while (size) {
300 		if (fp->off < 0 || fp->off >= fp->size)
301 			break;
302 		bno = fp->off / ISO_DEFAULT_BLOCK_SIZE + fp->bno;
303 		if (fp->off & (ISO_DEFAULT_BLOCK_SIZE - 1)
304 		    || size < ISO_DEFAULT_BLOCK_SIZE)
305 			dp = buf;
306 		else
307 			dp = start;
308 		twiddle();
309 		rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno),
310 					   ISO_DEFAULT_BLOCK_SIZE, dp, &read);
311 		if (rc)
312 			return rc;
313 		if (read != ISO_DEFAULT_BLOCK_SIZE)
314 			return EIO;
315 		if (dp == buf) {
316 			off = fp->off & (ISO_DEFAULT_BLOCK_SIZE - 1);
317 			if (read > off + size)
318 				read = off + size;
319 			read -= off;
320 			bcopy(buf + off, start, read);
321 			start += read;
322 			fp->off += read;
323 			size -= read;
324 		} else {
325 			start += ISO_DEFAULT_BLOCK_SIZE;
326 			fp->off += ISO_DEFAULT_BLOCK_SIZE;
327 			size -= ISO_DEFAULT_BLOCK_SIZE;
328 		}
329 	}
330 	if (resid)
331 		*resid = size;
332 	return rc;
333 }
334 
335 int
336 cd9660_write(f, start, size, resid)
337 	struct open_file *f;
338 	void *start;
339 	size_t size;
340 	size_t *resid;
341 {
342 	return EROFS;
343 }
344 
345 off_t
346 cd9660_seek(f, offset, where)
347 	struct open_file *f;
348 	off_t offset;
349 	int where;
350 {
351 	struct file *fp = (struct file *)f->f_fsdata;
352 
353 	switch (where) {
354 	case SEEK_SET:
355 		fp->off = offset;
356 		break;
357 	case SEEK_CUR:
358 		fp->off += offset;
359 		break;
360 	case SEEK_END:
361 		fp->off = fp->size - offset;
362 		break;
363 	default:
364 		return -1;
365 	}
366 	return fp->off;
367 }
368 
369 int
370 cd9660_stat(f, sb)
371 	struct open_file *f;
372 	struct stat *sb;
373 {
374 	struct file *fp = (struct file *)f->f_fsdata;
375 
376 	/* only importatn stuff */
377 	sb->st_mode = S_IFREG | S_IRUSR | S_IRGRP | S_IROTH;
378 	sb->st_uid = sb->st_gid = 0;
379 	sb->st_size = fp->size;
380 	return 0;
381 }
382