1 /*
2 * Copyright (C) 1996 Wolfgang Solfrank.
3 * Copyright (C) 1996 TooLs GmbH.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by TooLs GmbH.
17 * 4. The name of TooLs GmbH may not be used to endorse or promote products
18 * derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 /* Originally derived from libsa/cd9660.c: */
33 /* $NetBSD: cd9660.c,v 1.5 1997/06/26 19:11:33 drochner Exp $ */
34
35 #include <sys/cdefs.h>
36 #include <sys/param.h>
37
38 #include <fs/cd9660/iso.h>
39 #include <fs/cd9660/cd9660_rrip.h>
40
41 static uint64_t cd9660_lookup(const char *);
42 static ssize_t cd9660_fsread(uint64_t, void *, size_t);
43
44 #define SUSP_CONTINUATION "CE"
45 #define SUSP_PRESENT "SP"
46 #define SUSP_STOP "ST"
47 #define SUSP_EXTREF "ER"
48 #define RRIP_NAME "NM"
49
50 typedef struct {
51 ISO_SUSP_HEADER h;
52 uint8_t signature [ISODCL(5, 6)];
53 uint8_t len_skp [ISODCL(7, 7)]; /* 711 */
54 } ISO_SUSP_PRESENT;
55
56 #define cdb2devb(bno) ((bno) * ISO_DEFAULT_BLOCK_SIZE / DEV_BSIZE)
57
58 static int
read_iso_block(void * buffer,daddr_t blkno)59 read_iso_block(void *buffer, daddr_t blkno)
60 {
61
62 return (drvread(&dsk, buffer, cdb2devb(blkno),
63 ISO_DEFAULT_BLOCK_SIZE / DEV_BSIZE));
64 }
65
66 static ISO_SUSP_HEADER *
susp_lookup_record(const char * identifier,struct iso_directory_record * dp,int lenskip)67 susp_lookup_record(const char *identifier, struct iso_directory_record *dp,
68 int lenskip)
69 {
70 static char susp_buffer[ISO_DEFAULT_BLOCK_SIZE];
71 ISO_SUSP_HEADER *sh;
72 ISO_RRIP_CONT *shc;
73 char *p, *end;
74 int error;
75
76 p = dp->name + isonum_711(dp->name_len) + lenskip;
77 /* Names of even length have a padding byte after the name. */
78 if ((isonum_711(dp->name_len) & 1) == 0)
79 p++;
80 end = (char *)dp + isonum_711(dp->length);
81 while (p + 3 < end) {
82 sh = (ISO_SUSP_HEADER *)p;
83 if (bcmp(sh->type, identifier, 2) == 0)
84 return (sh);
85 if (bcmp(sh->type, SUSP_STOP, 2) == 0)
86 return (NULL);
87 if (bcmp(sh->type, SUSP_CONTINUATION, 2) == 0) {
88 shc = (ISO_RRIP_CONT *)sh;
89 error = read_iso_block(susp_buffer,
90 isonum_733(shc->location));
91
92 /* Bail if it fails. */
93 if (error != 0)
94 return (NULL);
95 p = susp_buffer + isonum_733(shc->offset);
96 end = p + isonum_733(shc->length);
97 } else {
98 /* Ignore this record and skip to the next. */
99 p += isonum_711(sh->length);
100
101 /* Avoid infinite loops with corrupted file systems */
102 if (isonum_711(sh->length) == 0)
103 return (NULL);
104 }
105 }
106 return (NULL);
107 }
108
109 static const char *
rrip_lookup_name(struct iso_directory_record * dp,int lenskip,size_t * len)110 rrip_lookup_name(struct iso_directory_record *dp, int lenskip, size_t *len)
111 {
112 ISO_RRIP_ALTNAME *p;
113
114 if (len == NULL)
115 return (NULL);
116
117 p = (ISO_RRIP_ALTNAME *)susp_lookup_record(RRIP_NAME, dp, lenskip);
118 if (p == NULL)
119 return (NULL);
120 switch (*p->flags) {
121 case ISO_SUSP_CFLAG_CURRENT:
122 *len = 1;
123 return (".");
124 case ISO_SUSP_CFLAG_PARENT:
125 *len = 2;
126 return ("..");
127 case 0:
128 *len = isonum_711(p->h.length) - 5;
129 return ((char *)p + 5);
130 default:
131 /*
132 * We don't handle hostnames or continued names as they are
133 * too hard, so just bail and use the default name.
134 */
135 return (NULL);
136 }
137 }
138
139 static int
rrip_check(struct iso_directory_record * dp,int * lenskip)140 rrip_check(struct iso_directory_record *dp, int *lenskip)
141 {
142 ISO_SUSP_PRESENT *sp;
143 ISO_RRIP_EXTREF *er;
144 char *p;
145
146 /* First, see if we can find a SP field. */
147 p = dp->name + isonum_711(dp->name_len);
148 if (p > (char *)dp + isonum_711(dp->length)) {
149 return (0);
150 }
151 sp = (ISO_SUSP_PRESENT *)p;
152 if (bcmp(sp->h.type, SUSP_PRESENT, 2) != 0) {
153 return (0);
154 }
155 if (isonum_711(sp->h.length) != sizeof (ISO_SUSP_PRESENT)) {
156 return (0);
157 }
158 if (sp->signature[0] != 0xbe || sp->signature[1] != 0xef) {
159 return (0);
160 }
161 *lenskip = isonum_711(sp->len_skp);
162
163 /*
164 * Now look for an ER field. If RRIP is present, then there must
165 * be at least one of these. It would be more pedantic to walk
166 * through the list of fields looking for a Rock Ridge ER field.
167 */
168 er = (ISO_RRIP_EXTREF *)susp_lookup_record(SUSP_EXTREF, dp, 0);
169 if (er == NULL) {
170 return (0);
171 }
172 return (1);
173 }
174
175 static int
dirmatch(const char * path,struct iso_directory_record * dp,int use_rrip,int lenskip)176 dirmatch(const char *path, struct iso_directory_record *dp, int use_rrip,
177 int lenskip)
178 {
179 size_t len;
180 const char *cp = NULL;
181 int i, icase;
182
183 if (use_rrip)
184 cp = rrip_lookup_name(dp, lenskip, &len);
185 else
186 cp = NULL;
187 if (cp == NULL) {
188 len = isonum_711(dp->name_len);
189 cp = dp->name;
190 icase = 1;
191 } else
192 icase = 0;
193 for (i = len; --i >= 0; path++, cp++) {
194 if (!*path || *path == '/')
195 break;
196 if (*path == *cp)
197 continue;
198 if (!icase && toupper(*path) == *cp)
199 continue;
200 return (0);
201 }
202 if (*path && *path != '/') {
203 return (0);
204 }
205 /*
206 * Allow stripping of trailing dots and the version number.
207 * Note that this will find the first instead of the last version
208 * of a file.
209 */
210 if (i >= 0 && (*cp == ';' || *cp == '.')) {
211 /* This is to prevent matching of numeric extensions */
212 if (*cp == '.' && cp[1] != ';') {
213 return (0);
214 }
215 while (--i >= 0)
216 if (*++cp != ';' && (*cp < '0' || *cp > '9')) {
217 return (0);
218 }
219 }
220 return (1);
221 }
222
223 static uint64_t
cd9660_lookup(const char * path)224 cd9660_lookup(const char *path)
225 {
226 static char blkbuf[MAX(ISO_DEFAULT_BLOCK_SIZE,
227 sizeof (struct iso_primary_descriptor))];
228 struct iso_primary_descriptor *vd;
229 struct iso_directory_record rec;
230 struct iso_directory_record *dp = NULL;
231 size_t dsize, off;
232 daddr_t bno, boff;
233 int rc, first, use_rrip, lenskip;
234 uint64_t cookie;
235
236 for (bno = 16; ; bno++) {
237 rc = read_iso_block(blkbuf, bno);
238 if (rc != 0)
239 return (0);
240 vd = (struct iso_primary_descriptor *)blkbuf;
241
242 if (bcmp(vd->id, ISO_STANDARD_ID, sizeof (vd->id)) != 0)
243 return (0);
244 if (isonum_711(vd->type) == ISO_VD_END)
245 return (0);
246 if (isonum_711(vd->type) == ISO_VD_PRIMARY)
247 break;
248 }
249
250 bcopy(vd->root_directory_record, &rec, sizeof (rec));
251 if (*path == '/') path++; /* eat leading '/' */
252
253 first = 1;
254 use_rrip = 0;
255 lenskip = 0;
256 while (*path) {
257 bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length);
258 dsize = isonum_733(rec.size);
259 off = 0;
260 boff = 0;
261
262 while (off < dsize) {
263 if ((off % ISO_DEFAULT_BLOCK_SIZE) == 0) {
264 rc = read_iso_block(blkbuf, bno + boff);
265 if (rc) {
266 return (0);
267 }
268 boff++;
269 dp = (struct iso_directory_record *)blkbuf;
270 }
271 if (isonum_711(dp->length) == 0) {
272 /* skip to next block, if any */
273 off = boff * ISO_DEFAULT_BLOCK_SIZE;
274 continue;
275 }
276
277 /* See if RRIP is in use. */
278 if (first)
279 use_rrip = rrip_check(dp, &lenskip);
280
281 if (dirmatch(path, dp, use_rrip,
282 first ? 0 : lenskip)) {
283 first = 0;
284 break;
285 } else
286 first = 0;
287
288 dp = (struct iso_directory_record *)
289 ((char *)dp + isonum_711(dp->length));
290 /* If the new block has zero length, it is padding. */
291 if (isonum_711(dp->length) == 0) {
292 /* Skip to next block, if any. */
293 off = boff * ISO_DEFAULT_BLOCK_SIZE;
294 continue;
295 }
296 off += isonum_711(dp->length);
297 }
298 if (off >= dsize) {
299 return (0);
300 }
301
302 rec = *dp;
303 while (*path && *path != '/') /* look for next component */
304 path++;
305 if (*path) path++; /* skip '/' */
306 }
307
308 if ((isonum_711(rec.flags) & 2) != 0) {
309 return (0);
310 }
311
312 cookie = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length);
313 cookie = (cookie << 32) | isonum_733(rec.size);
314
315 return (cookie);
316 }
317
318 static ssize_t
cd9660_fsread(uint64_t cookie,void * buf,size_t nbytes)319 cd9660_fsread(uint64_t cookie, void *buf, size_t nbytes)
320 {
321 static char blkbuf[ISO_DEFAULT_BLOCK_SIZE];
322 static daddr_t curstart = 0, curblk = 0;
323 daddr_t blk, blk_off;
324 off_t byte_off;
325 size_t size, remaining, n;
326 char *s;
327
328 size = cookie & 0xffffffff;
329 blk = (cookie >> 32) & 0xffffffff;
330
331 /* Make sure we're looking at the right file. */
332 if ((uint64_t)((blk << 32) | size) != cookie) {
333 return (-1);
334 }
335
336 if (blk != curstart) {
337 curstart = blk;
338 fs_off = 0;
339 }
340
341 size -= fs_off;
342 if (size < nbytes) {
343 nbytes = size;
344 }
345 remaining = nbytes;
346 s = buf;
347
348 while (remaining > 0) {
349 blk_off = fs_off >> ISO_DEFAULT_BLOCK_SHIFT;
350 byte_off = fs_off & (ISO_DEFAULT_BLOCK_SIZE - 1);
351
352 if (curblk != curstart + blk_off) {
353 curblk = curstart + blk_off;
354 read_iso_block(blkbuf, curblk);
355 }
356
357 if (remaining < ISO_DEFAULT_BLOCK_SIZE - byte_off) {
358 n = remaining;
359 } else {
360 n = ISO_DEFAULT_BLOCK_SIZE - byte_off;
361 }
362 memcpy(s, blkbuf + byte_off, n);
363 remaining -= n;
364 s += n;
365
366 fs_off += n;
367 }
368
369 return (nbytes);
370 }
371