xref: /minix/sys/lib/libsa/cd9660.c (revision f14fb602)
1 /*	$NetBSD: cd9660.c,v 1.29 2012/07/23 00:49:20 mhitch 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 		    || (fp->off + ISO_DEFAULT_BLOCK_SIZE) > fp->size
322 		    || size < ISO_DEFAULT_BLOCK_SIZE)
323 			dp = buf;
324 		else
325 			dp = start;
326 #if !defined(LIBSA_NO_TWIDDLE)
327 		twiddle();
328 #endif
329 		rc = DEV_STRATEGY(f->f_dev)(f->f_devdata, F_READ, cdb2devb(bno),
330 		                            ISO_DEFAULT_BLOCK_SIZE, dp, &nread);
331 		if (rc)
332 			return rc;
333 		if (nread != ISO_DEFAULT_BLOCK_SIZE)
334 			return EIO;
335 		if (dp == buf) {
336 			off = fp->off & (ISO_DEFAULT_BLOCK_SIZE - 1);
337 			if (nread > off + size)
338 				nread = off + size;
339 			nread -= off;
340 			if (nread > fp->size - fp->off)
341 				nread = fp->size - fp->off;
342 			memcpy(start, buf + off, nread);
343 			start = (char *)start + nread;
344 			fp->off += nread;
345 			size -= nread;
346 		} else {
347 			start = (char *)start + ISO_DEFAULT_BLOCK_SIZE;
348 			fp->off += ISO_DEFAULT_BLOCK_SIZE;
349 			size -= ISO_DEFAULT_BLOCK_SIZE;
350 		}
351 	}
352 	if(fp->off > fp->size)
353 		size += fp->off - fp->size;
354 	if (resid)
355 		*resid = size;
356 	return rc;
357 }
358 
359 #if !defined(LIBSA_NO_FS_WRITE)
360 __compactcall int
361 cd9660_write(struct open_file *f, void *start, size_t size, size_t *resid)
362 {
363 
364 	return EROFS;
365 }
366 #endif /* !defined(LIBSA_NO_FS_WRITE) */
367 
368 #if !defined(LIBSA_NO_FS_SEEK)
369 __compactcall off_t
370 cd9660_seek(struct open_file *f, off_t offset, int where)
371 {
372 	struct file *fp = (struct file *)f->f_fsdata;
373 
374 	switch (where) {
375 	case SEEK_SET:
376 		fp->off = offset;
377 		break;
378 	case SEEK_CUR:
379 		fp->off += offset;
380 		break;
381 	case SEEK_END:
382 		fp->off = fp->size - offset;
383 		break;
384 	default:
385 		return -1;
386 	}
387 	return fp->off;
388 }
389 #endif /* !defined(LIBSA_NO_FS_SEEK) */
390 
391 __compactcall int
392 cd9660_stat(struct open_file *f, struct stat *sb)
393 {
394 	struct file *fp = (struct file *)f->f_fsdata;
395 
396 	/* only importatn stuff */
397 	sb->st_mode = S_IFREG | S_IRUSR | S_IRGRP | S_IROTH;
398 	sb->st_uid = sb->st_gid = 0;
399 	sb->st_size = fp->size;
400 	return 0;
401 }
402 
403 #if defined(LIBSA_ENABLE_LS_OP)
404 __compactcall void
405 cd9660_ls(struct open_file *f, const char *pattern,
406 		void (*funcp)(char* arg), char* path)
407 {
408 	printf("Currently ls command is unsupported by cd9660\n");
409 	return;
410 }
411 #endif
412