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#include <sys/cdefs.h>
35__FBSDID("$FreeBSD$");
36
37/*
38 * Stand-alone ISO9660 file reading package.
39 *
40 * Note: This doesn't support Rock Ridge extensions, extended attributes,
41 * blocksizes other than 2048 bytes, multi-extent files, etc.
42 */
43#include <sys/param.h>
44#include <string.h>
45#include <sys/dirent.h>
46#include <isofs/cd9660/iso.h>
47#include <isofs/cd9660/cd9660_rrip.h>
48
49#include "stand.h"
50
51#define	SUSP_CONTINUATION	"CE"
52#define	SUSP_PRESENT		"SP"
53#define	SUSP_STOP		"ST"
54#define	SUSP_EXTREF		"ER"
55#define	RRIP_NAME		"NM"
56
57typedef struct {
58	ISO_SUSP_HEADER		h;
59	u_char signature	[ISODCL (  5,    6)];
60	u_char len_skp		[ISODCL (  7,    7)]; /* 711 */
61} ISO_SUSP_PRESENT;
62
63static int	buf_read_file(struct open_file *f, char **buf_p,
64		    size_t *size_p);
65static int	cd9660_open(const char *path, struct open_file *f);
66static int	cd9660_close(struct open_file *f);
67static int	cd9660_read(struct open_file *f, void *buf, size_t size,
68		    size_t *resid);
69static int	cd9660_write(struct open_file *f, void *buf, size_t size,
70		    size_t *resid);
71static off_t	cd9660_seek(struct open_file *f, off_t offset, int where);
72static int	cd9660_stat(struct open_file *f, struct stat *sb);
73static int	cd9660_readdir(struct open_file *f, struct dirent *d);
74static int	dirmatch(struct open_file *f, const char *path,
75		    struct iso_directory_record *dp, int use_rrip, int lenskip);
76static int	rrip_check(struct open_file *f, struct iso_directory_record *dp,
77		    int *lenskip);
78static char	*rrip_lookup_name(struct open_file *f,
79		    struct iso_directory_record *dp, int lenskip, size_t *len);
80static ISO_SUSP_HEADER *susp_lookup_record(struct open_file *f,
81		    const char *identifier, struct iso_directory_record *dp,
82		    int lenskip);
83
84struct fs_ops cd9660_fsops = {
85	"cd9660",
86	cd9660_open,
87	cd9660_close,
88	cd9660_read,
89	cd9660_write,
90	cd9660_seek,
91	cd9660_stat,
92	cd9660_readdir
93};
94
95#define	F_ISDIR		0x0001		/* Directory */
96#define	F_ROOTDIR	0x0002		/* Root directory */
97#define	F_RR		0x0004		/* Rock Ridge on this volume */
98
99struct file {
100	int 		f_flags;	/* file flags */
101	off_t 		f_off;		/* Current offset within file */
102	daddr_t 	f_bno;		/* Starting block number */
103	off_t 		f_size;		/* Size of file */
104	daddr_t		f_buf_blkno;	/* block number of data block */
105	char		*f_buf;		/* buffer for data block */
106	int		f_susp_skip;	/* len_skip for SUSP records */
107};
108
109struct ptable_ent {
110	char namlen	[ISODCL( 1, 1)];	/* 711 */
111	char extlen	[ISODCL( 2, 2)];	/* 711 */
112	char block	[ISODCL( 3, 6)];	/* 732 */
113	char parent	[ISODCL( 7, 8)];	/* 722 */
114	char name	[1];
115};
116#define	PTFIXSZ		8
117#define	PTSIZE(pp)	roundup(PTFIXSZ + isonum_711((pp)->namlen), 2)
118
119#define	cdb2devb(bno)	((bno) * ISO_DEFAULT_BLOCK_SIZE / DEV_BSIZE)
120
121static ISO_SUSP_HEADER *
122susp_lookup_record(struct open_file *f, const char *identifier,
123    struct iso_directory_record *dp, int lenskip)
124{
125	static char susp_buffer[ISO_DEFAULT_BLOCK_SIZE];
126	ISO_SUSP_HEADER *sh;
127	ISO_RRIP_CONT *shc;
128	char *p, *end;
129	int error;
130	size_t read;
131
132	p = dp->name + isonum_711(dp->name_len) + lenskip;
133	/* Names of even length have a padding byte after the name. */
134	if ((isonum_711(dp->name_len) & 1) == 0)
135		p++;
136	end = (char *)dp + isonum_711(dp->length);
137	while (p + 3 < end) {
138		sh = (ISO_SUSP_HEADER *)p;
139		if (bcmp(sh->type, identifier, 2) == 0)
140			return (sh);
141		if (bcmp(sh->type, SUSP_STOP, 2) == 0)
142			return (NULL);
143		if (bcmp(sh->type, SUSP_CONTINUATION, 2) == 0) {
144			shc = (ISO_RRIP_CONT *)sh;
145			error = f->f_dev->dv_strategy(f->f_devdata, F_READ,
146			    cdb2devb(isonum_733(shc->location)),
147			    ISO_DEFAULT_BLOCK_SIZE, susp_buffer, &read);
148
149			/* Bail if it fails. */
150			if (error != 0 || read != ISO_DEFAULT_BLOCK_SIZE)
151				return (NULL);
152			p = susp_buffer + isonum_733(shc->offset);
153			end = p + isonum_733(shc->length);
154		} else
155			/* Ignore this record and skip to the next. */
156			p += isonum_711(sh->length);
157	}
158	return (NULL);
159}
160
161static char *
162rrip_lookup_name(struct open_file *f, struct iso_directory_record *dp,
163    int lenskip, size_t *len)
164{
165	ISO_RRIP_ALTNAME *p;
166
167	if (len == NULL)
168		return (NULL);
169
170	p = (ISO_RRIP_ALTNAME *)susp_lookup_record(f, RRIP_NAME, dp, lenskip);
171	if (p == NULL)
172		return (NULL);
173	switch (*p->flags) {
174	case ISO_SUSP_CFLAG_CURRENT:
175		*len = 1;
176		return (".");
177	case ISO_SUSP_CFLAG_PARENT:
178		*len = 2;
179		return ("..");
180	case 0:
181		*len = isonum_711(p->h.length) - 5;
182		return ((char *)p + 5);
183	default:
184		/*
185		 * We don't handle hostnames or continued names as they are
186		 * too hard, so just bail and use the default name.
187		 */
188		return (NULL);
189	}
190}
191
192static int
193rrip_check(struct open_file *f, struct iso_directory_record *dp, int *lenskip)
194{
195	ISO_SUSP_PRESENT *sp;
196	ISO_RRIP_EXTREF *er;
197	char *p;
198
199	/* First, see if we can find a SP field. */
200	p = dp->name + isonum_711(dp->name_len);
201	if (p > (char *)dp + isonum_711(dp->length))
202		return (0);
203	sp = (ISO_SUSP_PRESENT *)p;
204	if (bcmp(sp->h.type, SUSP_PRESENT, 2) != 0)
205		return (0);
206	if (isonum_711(sp->h.length) != sizeof(ISO_SUSP_PRESENT))
207		return (0);
208	if (sp->signature[0] != 0xbe || sp->signature[1] != 0xef)
209		return (0);
210	*lenskip = isonum_711(sp->len_skp);
211
212	/*
213	 * Now look for an ER field.  If RRIP is present, then there must
214	 * be at least one of these.  It would be more pedantic to walk
215	 * through the list of fields looking for a Rock Ridge ER field.
216	 */
217	er = (ISO_RRIP_EXTREF *)susp_lookup_record(f, SUSP_EXTREF, dp, 0);
218	if (er == NULL)
219		return (0);
220	return (1);
221}
222
223static int
224dirmatch(struct open_file *f, const char *path, struct iso_directory_record *dp,
225    int use_rrip, int lenskip)
226{
227	size_t len;
228	char *cp;
229	int i, icase;
230
231	if (use_rrip)
232		cp = rrip_lookup_name(f, dp, lenskip, &len);
233	else
234		cp = NULL;
235	if (cp == NULL) {
236		len = isonum_711(dp->name_len);
237		cp = dp->name;
238		icase = 1;
239	} else
240		icase = 0;
241	for (i = len; --i >= 0; path++, cp++) {
242		if (!*path || *path == '/')
243			break;
244		if (*path == *cp)
245			continue;
246		if (!icase && toupper(*path) == *cp)
247			continue;
248		return 0;
249	}
250	if (*path && *path != '/')
251		return 0;
252	/*
253	 * Allow stripping of trailing dots and the version number.
254	 * Note that this will find the first instead of the last version
255	 * of a file.
256	 */
257	if (i >= 0 && (*cp == ';' || *cp == '.')) {
258		/* This is to prevent matching of numeric extensions */
259		if (*cp == '.' && cp[1] != ';')
260			return 0;
261		while (--i >= 0)
262			if (*++cp != ';' && (*cp < '0' || *cp > '9'))
263				return 0;
264	}
265	return 1;
266}
267
268static int
269cd9660_open(const char *path, struct open_file *f)
270{
271	struct file *fp = 0;
272	void *buf;
273	struct iso_primary_descriptor *vd;
274	size_t buf_size, read, dsize, off;
275	daddr_t bno, boff;
276	struct iso_directory_record rec;
277	struct iso_directory_record *dp = 0;
278	int rc, first, use_rrip, lenskip;
279
280	/* First find the volume descriptor */
281	buf = malloc(buf_size = ISO_DEFAULT_BLOCK_SIZE);
282	vd = buf;
283	for (bno = 16;; bno++) {
284		twiddle();
285		rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno),
286					   ISO_DEFAULT_BLOCK_SIZE, buf, &read);
287		if (rc)
288			goto out;
289		if (read != ISO_DEFAULT_BLOCK_SIZE) {
290			rc = EIO;
291			goto out;
292		}
293		rc = EINVAL;
294		if (bcmp(vd->id, ISO_STANDARD_ID, sizeof vd->id) != 0)
295			goto out;
296		if (isonum_711(vd->type) == ISO_VD_END)
297			goto out;
298		if (isonum_711(vd->type) == ISO_VD_PRIMARY)
299			break;
300	}
301	if (isonum_723(vd->logical_block_size) != ISO_DEFAULT_BLOCK_SIZE)
302		goto out;
303
304	rec = *(struct iso_directory_record *) vd->root_directory_record;
305	if (*path == '/') path++; /* eat leading '/' */
306
307	first = 1;
308	use_rrip = 0;
309	while (*path) {
310		bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length);
311		dsize = isonum_733(rec.size);
312		off = 0;
313		boff = 0;
314
315		while (off < dsize) {
316			if ((off % ISO_DEFAULT_BLOCK_SIZE) == 0) {
317				twiddle();
318				rc = f->f_dev->dv_strategy
319					(f->f_devdata, F_READ,
320					 cdb2devb(bno + boff),
321					 ISO_DEFAULT_BLOCK_SIZE,
322					 buf, &read);
323				if (rc)
324					goto out;
325				if (read != ISO_DEFAULT_BLOCK_SIZE) {
326					rc = EIO;
327					goto out;
328				}
329				boff++;
330				dp = (struct iso_directory_record *) buf;
331			}
332			if (isonum_711(dp->length) == 0) {
333			    /* skip to next block, if any */
334			    off = boff * ISO_DEFAULT_BLOCK_SIZE;
335			    continue;
336			}
337
338			/* See if RRIP is in use. */
339			if (first)
340				use_rrip = rrip_check(f, dp, &lenskip);
341
342			if (dirmatch(f, path, dp, use_rrip,
343				first ? 0 : lenskip)) {
344				first = 0;
345				break;
346			} else
347				first = 0;
348
349			dp = (struct iso_directory_record *)
350				((char *) dp + isonum_711(dp->length));
351			off += isonum_711(dp->length);
352		}
353		if (off >= dsize) {
354			rc = ENOENT;
355			goto out;
356		}
357
358		rec = *dp;
359		while (*path && *path != '/') /* look for next component */
360			path++;
361		if (*path) path++; /* skip '/' */
362	}
363
364	/* allocate file system specific data structure */
365	fp = malloc(sizeof(struct file));
366	bzero(fp, sizeof(struct file));
367	f->f_fsdata = (void *)fp;
368
369	if ((isonum_711(rec.flags) & 2) != 0) {
370		fp->f_flags = F_ISDIR;
371	}
372	if (first) {
373		fp->f_flags |= F_ROOTDIR;
374
375		/* Check for Rock Ridge since we didn't in the loop above. */
376		bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length);
377		twiddle();
378		rc = f->f_dev->dv_strategy(f->f_devdata, F_READ, cdb2devb(bno),
379		    ISO_DEFAULT_BLOCK_SIZE, buf, &read);
380		if (rc)
381			goto out;
382		if (read != ISO_DEFAULT_BLOCK_SIZE) {
383			rc = EIO;
384			goto out;
385		}
386		dp = (struct iso_directory_record *)buf;
387		use_rrip = rrip_check(f, dp, &lenskip);
388	}
389	if (use_rrip) {
390		fp->f_flags |= F_RR;
391		fp->f_susp_skip = lenskip;
392	}
393	fp->f_off = 0;
394	fp->f_bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length);
395	fp->f_size = isonum_733(rec.size);
396	free(buf);
397
398	return 0;
399
400out:
401	if (fp)
402		free(fp);
403	free(buf);
404
405	return rc;
406}
407
408static int
409cd9660_close(struct open_file *f)
410{
411	struct file *fp = (struct file *)f->f_fsdata;
412
413	f->f_fsdata = 0;
414	free(fp);
415
416	return 0;
417}
418
419static int
420buf_read_file(struct open_file *f, char **buf_p, size_t *size_p)
421{
422	struct file *fp = (struct file *)f->f_fsdata;
423	daddr_t blkno, blkoff;
424	int rc = 0;
425	size_t read;
426
427	blkno = fp->f_off / ISO_DEFAULT_BLOCK_SIZE + fp->f_bno;
428	blkoff = fp->f_off % ISO_DEFAULT_BLOCK_SIZE;
429
430	if (blkno != fp->f_buf_blkno) {
431		if (fp->f_buf == (char *)0)
432			fp->f_buf = malloc(ISO_DEFAULT_BLOCK_SIZE);
433
434		twiddle();
435		rc = f->f_dev->dv_strategy(f->f_devdata, F_READ,
436		    cdb2devb(blkno), ISO_DEFAULT_BLOCK_SIZE, fp->f_buf, &read);
437		if (rc)
438			return (rc);
439		if (read != ISO_DEFAULT_BLOCK_SIZE)
440			return (EIO);
441
442		fp->f_buf_blkno = blkno;
443	}
444
445	*buf_p = fp->f_buf + blkoff;
446	*size_p = ISO_DEFAULT_BLOCK_SIZE - blkoff;
447
448	if (*size_p > fp->f_size - fp->f_off)
449		*size_p = fp->f_size - fp->f_off;
450	return (rc);
451}
452
453static int
454cd9660_read(struct open_file *f, void *start, size_t size, size_t *resid)
455{
456	struct file *fp = (struct file *)f->f_fsdata;
457	char *buf, *addr;
458	size_t buf_size, csize;
459	int rc = 0;
460
461	addr = start;
462	while (size) {
463		if (fp->f_off < 0 || fp->f_off >= fp->f_size)
464			break;
465
466		rc = buf_read_file(f, &buf, &buf_size);
467		if (rc)
468			break;
469
470		csize = size > buf_size ? buf_size : size;
471		bcopy(buf, addr, csize);
472
473		fp->f_off += csize;
474		addr += csize;
475		size -= csize;
476	}
477	if (resid)
478		*resid = size;
479	return (rc);
480}
481
482static int
483cd9660_readdir(struct open_file *f, struct dirent *d)
484{
485	struct file *fp = (struct file *)f->f_fsdata;
486	struct iso_directory_record *ep;
487	size_t buf_size, reclen, namelen;
488	int error = 0;
489	int lenskip;
490	char *buf, *name;
491
492again:
493	if (fp->f_off >= fp->f_size)
494		return (ENOENT);
495	error = buf_read_file(f, &buf, &buf_size);
496	if (error)
497		return (error);
498	ep = (struct iso_directory_record *)buf;
499
500	if (isonum_711(ep->length) == 0) {
501		daddr_t blkno;
502
503		/* skip to next block, if any */
504		blkno = fp->f_off / ISO_DEFAULT_BLOCK_SIZE;
505		fp->f_off = (blkno + 1) * ISO_DEFAULT_BLOCK_SIZE;
506		goto again;
507	}
508
509	if (fp->f_flags & F_RR) {
510		if (fp->f_flags & F_ROOTDIR && fp->f_off == 0)
511			lenskip = 0;
512		else
513			lenskip = fp->f_susp_skip;
514		name = rrip_lookup_name(f, ep, lenskip, &namelen);
515	} else
516		name = NULL;
517	if (name == NULL) {
518		namelen = isonum_711(ep->name_len);
519		name = ep->name;
520		if (namelen == 1) {
521			if (ep->name[0] == 0)
522				name = ".";
523			else if (ep->name[0] == 1) {
524				namelen = 2;
525				name = "..";
526			}
527		}
528	}
529	reclen = sizeof(struct dirent) - (MAXNAMLEN+1) + namelen + 1;
530	reclen = (reclen + 3) & ~3;
531
532	d->d_fileno = isonum_733(ep->extent);
533	d->d_reclen = reclen;
534	if (isonum_711(ep->flags) & 2)
535		d->d_type = DT_DIR;
536	else
537		d->d_type = DT_REG;
538	d->d_namlen = namelen;
539
540	bcopy(name, d->d_name, d->d_namlen);
541	d->d_name[d->d_namlen] = 0;
542
543	fp->f_off += isonum_711(ep->length);
544	return (0);
545}
546
547static int
548cd9660_write(struct open_file *f __unused, void *start __unused, size_t size __unused, size_t *resid __unused)
549{
550	return EROFS;
551}
552
553static off_t
554cd9660_seek(struct open_file *f, off_t offset, int where)
555{
556	struct file *fp = (struct file *)f->f_fsdata;
557
558	switch (where) {
559	case SEEK_SET:
560		fp->f_off = offset;
561		break;
562	case SEEK_CUR:
563		fp->f_off += offset;
564		break;
565	case SEEK_END:
566		fp->f_off = fp->f_size - offset;
567		break;
568	default:
569		return -1;
570	}
571	return fp->f_off;
572}
573
574static int
575cd9660_stat(struct open_file *f, struct stat *sb)
576{
577	struct file *fp = (struct file *)f->f_fsdata;
578
579	/* only important stuff */
580	sb->st_mode = S_IRUSR | S_IRGRP | S_IROTH;
581	if (fp->f_flags & F_ISDIR)
582		sb->st_mode |= S_IFDIR;
583	else
584		sb->st_mode |= S_IFREG;
585	sb->st_uid = sb->st_gid = 0;
586	sb->st_size = fp->f_size;
587	return 0;
588}
589