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