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