1 /*
2 * ISO 9660 filesystem backend for GRUB (GRand Unified Bootloader)
3 * including Rock Ridge Extensions support
4 *
5 * Copyright (C) 1998, 1999 Kousuke Takai <tak@kmc.kyoto-u.ac.jp>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21 /*
22 * References:
23 * linux/fs/isofs/rock.[ch]
24 * mkisofs-1.11.1/diag/isoinfo.c
25 * mkisofs-1.11.1/iso9660.h
26 * (all are written by Eric Youngdale)
27 *
28 * Modifications by:
29 * Leonid Lisovskiy <lly@pisem.net> 2003
30 */
31
32 #ifdef FSYS_ISO9660
33
34 #include "shared.h"
35 #include "filesys.h"
36 #include "iso9660.h"
37
38 /* iso9660 super-block data in memory */
39 struct iso_sb_info {
40 unsigned long vol_sector;
41
42 };
43
44 /* iso fs inode data in memory */
45 struct iso_inode_info {
46 unsigned long file_start;
47 };
48
49 #define ISO_SUPER \
50 ((struct iso_sb_info *)(FSYS_BUF))
51 #define INODE \
52 ((struct iso_inode_info *)(FSYS_BUF+sizeof(struct iso_sb_info)))
53 #define PRIMDESC ((struct iso_primary_descriptor *)(FSYS_BUF + 2048))
54 #define DIRREC ((struct iso_directory_record *)(FSYS_BUF + 4096))
55 #define RRCONT_BUF ((unsigned char *)(FSYS_BUF + 6144))
56 #define NAME_BUF ((unsigned char *)(FSYS_BUF + 8192))
57
58
59 static inline unsigned long
grub_log2(unsigned long word)60 grub_log2 (unsigned long word)
61 {
62 asm volatile ("bsfl %1,%0"
63 : "=r" (word)
64 : "r" (word));
65 return word;
66 }
67 #define log2 grub_log2
68
69 static int
iso9660_devread(int sector,int byte_offset,int byte_len,char * buf)70 iso9660_devread (int sector, int byte_offset, int byte_len, char *buf)
71 {
72 static int read_count = 0, threshold = 2;
73 unsigned short sector_size_lg2 = log2(buf_geom.sector_size);
74
75 /*
76 * We have to use own devread() function since BIOS return wrong geometry
77 */
78 if (sector < 0)
79 {
80 errnum = ERR_OUTSIDE_PART;
81 return 0;
82 }
83 if (byte_len <= 0)
84 return 1;
85
86 sector += (byte_offset >> sector_size_lg2);
87 byte_offset &= (buf_geom.sector_size - 1);
88 asm volatile ("shl%L0 %1,%0"
89 : "=r"(sector)
90 : "Ic"((int8_t)(ISO_SECTOR_BITS - sector_size_lg2)),
91 "0"(sector));
92
93 #if !defined(STAGE1_5)
94 if (disk_read_hook && debug)
95 printf ("<%d, %d, %d>", sector, byte_offset, byte_len);
96 #endif /* !STAGE1_5 */
97
98 read_count += (byte_len >> 9);
99 if ((read_count >> 11) > threshold) {
100 noisy_printf(".");
101 threshold += 2; /* one dot every 2 MB */
102 }
103 return rawread(current_drive, part_start + sector, byte_offset, byte_len, buf);
104 }
105
106 int
iso9660_mount(void)107 iso9660_mount (void)
108 {
109 unsigned int sector;
110
111 /*
112 * Because there is no defined slice type ID for ISO-9660 filesystem,
113 * this test will pass only either (1) if entire disk is used, or
114 * (2) if current partition is BSD style sub-partition whose ID is
115 * ISO-9660.
116 */
117 if ((current_partition != 0xFFFFFF)
118 && !IS_PC_SLICE_TYPE_BSD_WITH_FS(current_slice, FS_ISO9660))
119 return 0;
120
121 /*
122 * Currently, only FIRST session of MultiSession disks are supported !!!
123 */
124 for (sector = 16 ; sector < 32 ; sector++)
125 {
126 if (!iso9660_devread(sector, 0, sizeof(*PRIMDESC), (char *)PRIMDESC))
127 break;
128 /* check ISO_VD_PRIMARY and ISO_STANDARD_ID */
129 if (PRIMDESC->type.l == ISO_VD_PRIMARY
130 && !memcmp(PRIMDESC->id, ISO_STANDARD_ID, sizeof(PRIMDESC->id)))
131 {
132 ISO_SUPER->vol_sector = sector;
133 INODE->file_start = 0;
134 fsmax = PRIMDESC->volume_space_size.l;
135 return 1;
136 }
137 }
138
139 return 0;
140 }
141
142 int
iso9660_dir(char * dirname)143 iso9660_dir (char *dirname)
144 {
145 struct iso_directory_record *idr;
146 RR_ptr_t rr_ptr;
147 struct rock_ridge *ce_ptr;
148 unsigned int pathlen;
149 int size;
150 unsigned int extent;
151 unsigned char file_type;
152 unsigned int rr_len;
153 unsigned char rr_flag;
154
155 idr = &PRIMDESC->root_directory_record;
156 INODE->file_start = 0;
157
158 do
159 {
160 while (*dirname == '/') /* skip leading slashes */
161 dirname++;
162 /* pathlen = strcspn(dirname, "/\n\t "); */
163 for (pathlen = 0 ;
164 dirname[pathlen]
165 && !isspace(dirname[pathlen]) && dirname[pathlen] != '/' ;
166 pathlen++)
167 ;
168
169 size = idr->size.l;
170 extent = idr->extent.l;
171
172 while (size > 0)
173 {
174 if (!iso9660_devread(extent, 0, ISO_SECTOR_SIZE, (char *)DIRREC))
175 {
176 errnum = ERR_FSYS_CORRUPT;
177 return 0;
178 }
179 extent++;
180
181 idr = (struct iso_directory_record *)DIRREC;
182 for (; idr->length.l > 0;
183 idr = (struct iso_directory_record *)((char *)idr + idr->length.l) )
184 {
185 const char *name = idr->name;
186 unsigned int name_len = idr->name_len.l;
187
188 file_type = (idr->flags.l & 2) ? ISO_DIRECTORY : ISO_REGULAR;
189 if (name_len == 1)
190 {
191 if ((name[0] == 0) || /* self */
192 (name[0] == 1)) /* parent */
193 continue;
194 }
195 if (name_len > 2 && CHECK2(name + name_len - 2, ';', '1'))
196 {
197 name_len -= 2; /* truncate trailing file version */
198 if (name_len > 1 && name[name_len - 1] == '.')
199 name_len--; /* truncate trailing dot */
200 }
201
202 /*
203 * Parse Rock-Ridge extension
204 */
205 rr_len = (idr->length.l - idr->name_len.l
206 - sizeof(struct iso_directory_record)
207 + sizeof(idr->name));
208 rr_ptr.ptr = ((unsigned char *)idr + idr->name_len.l
209 + sizeof(struct iso_directory_record)
210 - sizeof(idr->name));
211 if (rr_ptr.i & 1)
212 rr_ptr.i++, rr_len--;
213 ce_ptr = NULL;
214 rr_flag = RR_FLAG_NM | RR_FLAG_PX /*| RR_FLAG_SL*/;
215
216 while (rr_len >= 4)
217 {
218 if (rr_ptr.rr->version != 1)
219 {
220 #ifndef STAGE1_5
221 if (debug)
222 printf(
223 "Non-supported version (%d) RockRidge chunk "
224 "`%c%c'\n", rr_ptr.rr->version,
225 rr_ptr.rr->signature & 0xFF,
226 rr_ptr.rr->signature >> 8);
227 #endif
228 }
229 else
230 {
231 switch (rr_ptr.rr->signature)
232 {
233 case RRMAGIC('R', 'R'):
234 if ( rr_ptr.rr->len >= (4+sizeof(struct RR)))
235 rr_flag &= rr_ptr.rr->u.rr.flags.l;
236 break;
237 case RRMAGIC('N', 'M'):
238 name = rr_ptr.rr->u.nm.name;
239 name_len = rr_ptr.rr->len - (4+sizeof(struct NM));
240 rr_flag &= ~RR_FLAG_NM;
241 break;
242 case RRMAGIC('P', 'X'):
243 if (rr_ptr.rr->len >= (4+sizeof(struct PX)))
244 {
245 file_type = ((rr_ptr.rr->u.px.mode.l & POSIX_S_IFMT)
246 == POSIX_S_IFREG
247 ? ISO_REGULAR
248 : ((rr_ptr.rr->u.px.mode.l & POSIX_S_IFMT)
249 == POSIX_S_IFDIR
250 ? ISO_DIRECTORY : ISO_OTHER));
251 rr_flag &= ~RR_FLAG_PX;
252 }
253 break;
254 case RRMAGIC('C', 'E'):
255 if (rr_ptr.rr->len >= (4+sizeof(struct CE)))
256 ce_ptr = rr_ptr.rr;
257 break;
258 #if 0 // RockRidge symlinks are not supported yet
259 case RRMAGIC('S', 'L'):
260 {
261 int slen;
262 unsigned char rootflag, prevflag;
263 char *rpnt = NAME_BUF+1024;
264 struct SL_component *slp;
265
266 slen = rr_ptr.rr->len - (4+1);
267 slp = &rr_ptr.rr->u.sl.link;
268 while (slen > 1)
269 {
270 rootflag = 0;
271 switch (slp->flags.l)
272 {
273 case 0:
274 memcpy(rpnt, slp->text, slp->len);
275 rpnt += slp->len;
276 break;
277 case 4:
278 *rpnt++ = '.';
279 /* fallthru */
280 case 2:
281 *rpnt++ = '.';
282 break;
283 case 8:
284 rootflag = 1;
285 *rpnt++ = '/';
286 break;
287 default:
288 printf("Symlink component flag not implemented (%d)\n",
289 slp->flags.l);
290 slen = 0;
291 break;
292 }
293 slen -= slp->len + 2;
294 prevflag = slp->flags.l;
295 slp = (struct SL_component *) ((char *) slp + slp->len + 2);
296
297 if (slen < 2)
298 {
299 /*
300 * If there is another SL record, and this component
301 * record isn't continued, then add a slash.
302 */
303 if ((!rootflag) && (rr_ptr.rr->u.sl.flags.l & 1) && !(prevflag & 1))
304 *rpnt++='/';
305 break;
306 }
307
308 /*
309 * If this component record isn't continued, then append a '/'.
310 */
311 if (!rootflag && !(prevflag & 1))
312 *rpnt++ = '/';
313 }
314 *rpnt++ = '\0';
315 grub_putstr(NAME_BUF+1024);// debug print!
316 }
317 rr_flag &= ~RR_FLAG_SL;
318 break;
319 #endif
320 default:
321 break;
322 }
323 }
324 if (!rr_flag)
325 /*
326 * There is no more extension we expects...
327 */
328 break;
329
330 rr_len -= rr_ptr.rr->len;
331 rr_ptr.ptr += rr_ptr.rr->len;
332 if (rr_len < 4 && ce_ptr != NULL)
333 {
334 /* preserve name before loading new extent. */
335 if( RRCONT_BUF <= (unsigned char *)name
336 && (unsigned char *)name < RRCONT_BUF + ISO_SECTOR_SIZE )
337 {
338 memcpy(NAME_BUF, name, name_len);
339 name = NAME_BUF;
340 }
341 rr_ptr.ptr = RRCONT_BUF + ce_ptr->u.ce.offset.l;
342 rr_len = ce_ptr->u.ce.size.l;
343 if (!iso9660_devread(ce_ptr->u.ce.extent.l, 0, ISO_SECTOR_SIZE, RRCONT_BUF))
344 {
345 errnum = 0; /* this is not fatal. */
346 break;
347 }
348 ce_ptr = NULL;
349 }
350 } /* rr_len >= 4 */
351
352 filemax = MAXINT;
353 if (name_len >= pathlen
354 && !memcmp(name, dirname, pathlen))
355 {
356 if (dirname[pathlen] == '/' || !print_possibilities)
357 {
358 /*
359 * DIRNAME is directory component of pathname,
360 * or we are to open a file.
361 */
362 if (pathlen == name_len)
363 {
364 if (dirname[pathlen] == '/')
365 {
366 if (file_type != ISO_DIRECTORY)
367 {
368 errnum = ERR_BAD_FILETYPE;
369 return 0;
370 }
371 goto next_dir_level;
372 }
373 if (file_type != ISO_REGULAR)
374 {
375 errnum = ERR_BAD_FILETYPE;
376 return 0;
377 }
378 INODE->file_start = idr->extent.l;
379 filepos = 0;
380 filemax = idr->size.l;
381 return 1;
382 }
383 }
384 else /* Completion */
385 {
386 #ifndef STAGE1_5
387 if (print_possibilities > 0)
388 print_possibilities = -print_possibilities;
389 memcpy(NAME_BUF, name, name_len);
390 NAME_BUF[name_len] = '\0';
391 print_a_completion (NAME_BUF);
392 #endif
393 }
394 }
395 } /* for */
396
397 size -= ISO_SECTOR_SIZE;
398 } /* size>0 */
399
400 if (dirname[pathlen] == '/' || print_possibilities >= 0)
401 {
402 errnum = ERR_FILE_NOT_FOUND;
403 return 0;
404 }
405
406 next_dir_level:
407 dirname += pathlen;
408
409 } while (*dirname == '/');
410
411 return 1;
412 }
413
414 int
iso9660_read(char * buf,int len)415 iso9660_read (char *buf, int len)
416 {
417 int sector, blkoffset, size, ret;
418
419 if (INODE->file_start == 0)
420 return 0;
421
422 ret = 0;
423 blkoffset = filepos & (ISO_SECTOR_SIZE - 1);
424 sector = filepos >> ISO_SECTOR_BITS;
425 while (len > 0)
426 {
427 size = ISO_SECTOR_SIZE - blkoffset;
428 if (size > len)
429 size = len;
430
431 disk_read_func = disk_read_hook;
432
433 if (!iso9660_devread(INODE->file_start + sector, blkoffset, size, buf))
434 return 0;
435
436 disk_read_func = NULL;
437
438 len -= size;
439 buf += size;
440 ret += size;
441 filepos += size;
442 sector++;
443 blkoffset = 0;
444 }
445
446 return ret;
447 }
448
449 #endif /* FSYS_ISO9660 */
450