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 #include <fs/cd9660/iso.h>
38 #include <fs/cd9660/cd9660_rrip.h>
39
40 static uint64_t cd9660_lookup(const char *);
41 static ssize_t cd9660_fsread(uint64_t, void *, size_t);
42
43 #define SUSP_CONTINUATION "CE"
44 #define SUSP_PRESENT "SP"
45 #define SUSP_STOP "ST"
46 #define SUSP_EXTREF "ER"
47 #define RRIP_NAME "NM"
48
49 typedef struct {
50 ISO_SUSP_HEADER h;
51 u_char signature [ISODCL ( 5, 6)];
52 u_char len_skp [ISODCL ( 7, 7)]; /* 711 */
53 } ISO_SUSP_PRESENT;
54
55 static int
read_iso_block(void * buffer,daddr_t blkno)56 read_iso_block(void *buffer, daddr_t blkno)
57 {
58
59 return (drvread(&dsk, buffer, blkno * 4, 4));
60 }
61
62 static ISO_SUSP_HEADER *
susp_lookup_record(const char * identifier,struct iso_directory_record * dp,int lenskip)63 susp_lookup_record(const char *identifier, struct iso_directory_record *dp,
64 int lenskip)
65 {
66 static char susp_buffer[ISO_DEFAULT_BLOCK_SIZE];
67 ISO_SUSP_HEADER *sh;
68 ISO_RRIP_CONT *shc;
69 char *p, *end;
70 int error;
71
72 p = dp->name + isonum_711(dp->name_len) + lenskip;
73 /* Names of even length have a padding byte after the name. */
74 if ((isonum_711(dp->name_len) & 1) == 0)
75 p++;
76 end = (char *)dp + isonum_711(dp->length);
77 while (p + 3 < end) {
78 sh = (ISO_SUSP_HEADER *)p;
79 if (bcmp(sh->type, identifier, 2) == 0)
80 return (sh);
81 if (bcmp(sh->type, SUSP_STOP, 2) == 0)
82 return (NULL);
83 if (bcmp(sh->type, SUSP_CONTINUATION, 2) == 0) {
84 shc = (ISO_RRIP_CONT *)sh;
85 error = read_iso_block(susp_buffer,
86 isonum_733(shc->location));
87
88 /* Bail if it fails. */
89 if (error != 0)
90 return (NULL);
91 p = susp_buffer + isonum_733(shc->offset);
92 end = p + isonum_733(shc->length);
93 } else {
94 /* Ignore this record and skip to the next. */
95 p += isonum_711(sh->length);
96
97 /* Avoid infinite loops with corrupted file systems */
98 if (isonum_711(sh->length) == 0)
99 return (NULL);
100 }
101 }
102 return (NULL);
103 }
104
105 static const char *
rrip_lookup_name(struct iso_directory_record * dp,int lenskip,size_t * len)106 rrip_lookup_name(struct iso_directory_record *dp, int lenskip, size_t *len)
107 {
108 ISO_RRIP_ALTNAME *p;
109
110 if (len == NULL)
111 return (NULL);
112
113 p = (ISO_RRIP_ALTNAME *)susp_lookup_record(RRIP_NAME, dp, lenskip);
114 if (p == NULL)
115 return (NULL);
116 switch (*p->flags) {
117 case ISO_SUSP_CFLAG_CURRENT:
118 *len = 1;
119 return (".");
120 case ISO_SUSP_CFLAG_PARENT:
121 *len = 2;
122 return ("..");
123 case 0:
124 *len = isonum_711(p->h.length) - 5;
125 return ((char *)p + 5);
126 default:
127 /*
128 * We don't handle hostnames or continued names as they are
129 * too hard, so just bail and use the default name.
130 */
131 return (NULL);
132 }
133 }
134
135 static int
rrip_check(struct iso_directory_record * dp,int * lenskip)136 rrip_check(struct iso_directory_record *dp, int *lenskip)
137 {
138 ISO_SUSP_PRESENT *sp;
139 ISO_RRIP_EXTREF *er;
140 char *p;
141
142 /* First, see if we can find a SP field. */
143 p = dp->name + isonum_711(dp->name_len);
144 if (p > (char *)dp + isonum_711(dp->length)) {
145 return (0);
146 }
147 sp = (ISO_SUSP_PRESENT *)p;
148 if (bcmp(sp->h.type, SUSP_PRESENT, 2) != 0) {
149 return (0);
150 }
151 if (isonum_711(sp->h.length) != sizeof(ISO_SUSP_PRESENT)) {
152 return (0);
153 }
154 if (sp->signature[0] != 0xbe || sp->signature[1] != 0xef) {
155 return (0);
156 }
157 *lenskip = isonum_711(sp->len_skp);
158
159 /*
160 * Now look for an ER field. If RRIP is present, then there must
161 * be at least one of these. It would be more pedantic to walk
162 * through the list of fields looking for a Rock Ridge ER field.
163 */
164 er = (ISO_RRIP_EXTREF *)susp_lookup_record(SUSP_EXTREF, dp, 0);
165 if (er == NULL) {
166 return (0);
167 }
168 return (1);
169 }
170
171 static int
dirmatch(const char * path,struct iso_directory_record * dp,int use_rrip,int lenskip)172 dirmatch(const char *path, struct iso_directory_record *dp, int use_rrip,
173 int lenskip)
174 {
175 size_t len;
176 const char *cp = NULL;
177 int i, icase;
178
179 if (use_rrip)
180 cp = rrip_lookup_name(dp, lenskip, &len);
181 else
182 cp = NULL;
183 if (cp == NULL) {
184 len = isonum_711(dp->name_len);
185 cp = dp->name;
186 icase = 1;
187 } else
188 icase = 0;
189 for (i = len; --i >= 0; path++, cp++) {
190 if (!*path || *path == '/')
191 break;
192 if (*path == *cp)
193 continue;
194 if (!icase && toupper(*path) == *cp)
195 continue;
196 return 0;
197 }
198 if (*path && *path != '/') {
199 return 0;
200 }
201 /*
202 * Allow stripping of trailing dots and the version number.
203 * Note that this will find the first instead of the last version
204 * of a file.
205 */
206 if (i >= 0 && (*cp == ';' || *cp == '.')) {
207 /* This is to prevent matching of numeric extensions */
208 if (*cp == '.' && cp[1] != ';') {
209 return 0;
210 }
211 while (--i >= 0)
212 if (*++cp != ';' && (*cp < '0' || *cp > '9')) {
213 return 0;
214 }
215 }
216 return 1;
217 }
218
219 static uint64_t
cd9660_lookup(const char * path)220 cd9660_lookup(const char *path)
221 {
222 static char blkbuf[MAX(ISO_DEFAULT_BLOCK_SIZE,
223 sizeof(struct iso_primary_descriptor))];
224 struct iso_primary_descriptor *vd;
225 struct iso_directory_record rec;
226 struct iso_directory_record *dp = NULL;
227 size_t dsize, off;
228 daddr_t bno, boff;
229 int rc, first, use_rrip, lenskip;
230 uint64_t cookie;
231
232 for (bno = 16;; bno++) {
233 rc = read_iso_block(blkbuf, bno);
234 vd = (struct iso_primary_descriptor *)blkbuf;
235
236 if (bcmp(vd->id, ISO_STANDARD_ID, sizeof vd->id) != 0)
237 return (0);
238 if (isonum_711(vd->type) == ISO_VD_END)
239 return (0);
240 if (isonum_711(vd->type) == ISO_VD_PRIMARY)
241 break;
242 }
243
244 bcopy(vd->root_directory_record, &rec, sizeof(rec));
245 if (*path == '/') path++; /* eat leading '/' */
246
247 first = 1;
248 use_rrip = 0;
249 lenskip = 0;
250 while (*path) {
251 bno = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length);
252 dsize = isonum_733(rec.size);
253 off = 0;
254 boff = 0;
255
256 while (off < dsize) {
257 if ((off % ISO_DEFAULT_BLOCK_SIZE) == 0) {
258 rc = read_iso_block(blkbuf, bno + boff);
259 if (rc) {
260 return (0);
261 }
262 boff++;
263 dp = (struct iso_directory_record *) blkbuf;
264 }
265 if (isonum_711(dp->length) == 0) {
266 /* skip to next block, if any */
267 off = boff * ISO_DEFAULT_BLOCK_SIZE;
268 continue;
269 }
270
271 /* See if RRIP is in use. */
272 if (first)
273 use_rrip = rrip_check(dp, &lenskip);
274
275 if (dirmatch(path, dp, use_rrip,
276 first ? 0 : lenskip)) {
277 first = 0;
278 break;
279 } else
280 first = 0;
281
282 dp = (struct iso_directory_record *)
283 ((char *) dp + isonum_711(dp->length));
284 /* If the new block has zero length, it is padding. */
285 if (isonum_711(dp->length) == 0) {
286 /* Skip to next block, if any. */
287 off = boff * ISO_DEFAULT_BLOCK_SIZE;
288 continue;
289 }
290 off += isonum_711(dp->length);
291 }
292 if (off >= dsize) {
293 return (0);
294 }
295
296 rec = *dp;
297 while (*path && *path != '/') /* look for next component */
298 path++;
299 if (*path) path++; /* skip '/' */
300 }
301
302 if ((isonum_711(rec.flags) & 2) != 0) {
303 return (0);
304 }
305
306 cookie = isonum_733(rec.extent) + isonum_711(rec.ext_attr_length);
307 cookie = (cookie << 32) | isonum_733(rec.size);
308
309 return (cookie);
310 }
311
312 static ssize_t
cd9660_fsread(uint64_t cookie,void * buf,size_t nbytes)313 cd9660_fsread(uint64_t cookie, void *buf, size_t nbytes)
314 {
315 static char blkbuf[ISO_DEFAULT_BLOCK_SIZE];
316 static daddr_t curstart = 0, curblk = 0;
317 daddr_t blk, blk_off;
318 off_t byte_off;
319 size_t size, remaining, n;
320 char *s;
321
322 size = cookie & 0xffffffff;
323 blk = (cookie >> 32) & 0xffffffff;
324
325 /* Make sure we're looking at the right file. */
326 if (((blk << 32) | size) != cookie) {
327 return (-1);
328 }
329
330 if (blk != curstart) {
331 curstart = blk;
332 fs_off = 0;
333 }
334
335 size -= fs_off;
336 if (size < nbytes) {
337 nbytes = size;
338 }
339 remaining = nbytes;
340 s = buf;
341
342 while (remaining > 0) {
343 blk_off = fs_off >> ISO_DEFAULT_BLOCK_SHIFT;
344 byte_off = fs_off & (ISO_DEFAULT_BLOCK_SIZE - 1);
345
346 if (curblk != curstart + blk_off) {
347 curblk = curstart + blk_off;
348 read_iso_block(blkbuf, curblk);
349 }
350
351 if (remaining < ISO_DEFAULT_BLOCK_SIZE - byte_off) {
352 n = remaining;
353 } else {
354 n = ISO_DEFAULT_BLOCK_SIZE - byte_off;
355 }
356 memcpy(s, blkbuf + byte_off, n);
357 remaining -= n;
358 s += n;
359
360 fs_off += n;
361 }
362
363 return (nbytes);
364 }
365