fs/ufs.c

   1 /* ufs.c - Unix File System */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2004, 2005  Free Software Foundation, Inc.
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  */
  20
  21 #include <grub/err.h>
  22 #include <grub/file.h>
  23 #include <grub/mm.h>
  24 #include <grub/misc.h>
  25 #include <grub/disk.h>
  26 #include <grub/dl.h>
  27 #include <grub/types.h>
  28
  29
  30 #define GRUB_UFS_MAGIC          0x11954
  31 #define GRUB_UFS2_MAGIC         0x19540119
  32 #define GRUB_UFS_INODE          2
  33 #define GRUB_UFS_FILETYPE_DIR   4
  34 #define GRUB_UFS_FILETYPE_LNK   10
  35 #define GRUB_UFS_MAX_SYMLNK_CNT 8
  36
  37 #define GRUB_UFS_DIRBLKS        12
  38 #define GRUB_UFS_INDIRBLKS      3
  39
  40 #define GRUB_UFS_ATTR_DIR       040000
  41
  42 /* Calculate in which group the inode can be found.  */
  43 #define inode_group(inode,sblock) ()
  44
  45 #define UFS_BLKSZ(sblock) (grub_le_to_cpu32 (sblock->bsize))
  46
  47 #define INODE(data,field) (data->ufs_type == UFS1 ? \
  48                            data->inode.  field : data->inode2.  field)
  49 #define INODE_ENDIAN(data,field,bits1,bits2) (data->ufs_type == UFS1 ? \
  50                            grub_le_to_cpu##bits1 (data->inode.field) : \
  51                            grub_le_to_cpu##bits2 (data->inode2.field))
  52 #define INODE_SIZE(data) INODE_ENDIAN (data,size,32,64)
  53 #define INODE_MODE(data) INODE_ENDIAN (data,mode,16,16)
  54 #define INODE_BLKSZ(data) (data->ufs_type == UFS1 ? 32 : 64)
  55 #define INODE_DIRBLOCKS(data,blk) INODE_ENDIAN \
  56                                    (data,blocks.dir_blocks[blk],32,64)
  57 #define INODE_INDIRBLOCKS(data,blk) INODE_ENDIAN \
  58                                      (data,blocks.indir_blocks[blk],32,64)
  59
  60 /* The blocks on which the superblock can be found.  */
  61 static int sblocklist[] = { 128, 16, 0, 512, -1 };
  62
  63 struct grub_ufs_sblock
  64 {
  65   grub_uint8_t unused[16];
  66   /* The offset of the inodes in the cylinder group.  */
  67   grub_uint32_t inoblk_offs;
  68
  69   grub_uint8_t unused2[4];
  70
  71   /* The start of the cylinder group.  */
  72   grub_uint32_t cylg_offset;
  73
  74   grub_uint8_t unused3[20];
  75
  76   /* The size of a block in bytes.  */
  77   grub_int32_t bsize;
  78   grub_uint8_t unused4[48];
  79
  80   /* The size of filesystem blocks to disk blocks.  */
  81   grub_uint32_t log2_blksz;
  82   grub_uint8_t unused5[80];
  83
  84   /* Inodes stored per cylinder group.  */
  85   grub_uint32_t ino_per_group;
  86
  87   /* The frags per cylinder group.  */
  88   grub_uint32_t frags_per_group;
  89
  90   grub_uint8_t unused7[1180];
  91
  92   /* Magic value to check if this is really a UFS filesystem.  */
  93   grub_uint32_t magic;
  94 };
  95
  96 /* UFS inode.  */
  97 struct grub_ufs_inode
  98 {
  99   grub_uint16_t mode;
 100   grub_uint16_t nlinks;
 101   grub_uint16_t uid;
 102   grub_uint16_t gid;
 103   grub_int64_t size;
 104   grub_uint64_t atime;
 105   grub_uint64_t mtime;
 106   grub_uint64_t ctime;
 107   union
 108   {
 109     struct
 110     {
 111       grub_uint32_t dir_blocks[GRUB_UFS_DIRBLKS];
 112       grub_uint32_t indir_blocks[GRUB_UFS_INDIRBLKS];
 113     } blocks;
 114     grub_uint8_t symlink[(GRUB_UFS_DIRBLKS + GRUB_UFS_INDIRBLKS) * 4];
 115   };
 116   grub_uint32_t flags;
 117   grub_uint32_t nblocks;
 118   grub_uint32_t gen;
 119   grub_uint32_t unused;
 120   grub_uint8_t pad[12];
 121 };
 122
 123 /* UFS inode.  */
 124 struct grub_ufs2_inode
 125 {
 126   grub_uint16_t mode;
 127   grub_uint16_t nlinks;
 128   grub_uint32_t uid;
 129   grub_uint32_t gid;
 130   grub_uint32_t blocksize;
 131   grub_int64_t size;
 132   grub_int64_t nblocks;
 133   grub_uint64_t atime;
 134   grub_uint64_t mtime;
 135   grub_uint64_t ctime;
 136   grub_uint64_t create_time;
 137   grub_uint32_t atime_sec;
 138   grub_uint32_t mtime_sec;
 139   grub_uint32_t ctime_sec;
 140   grub_uint32_t create_time_sec;
 141   grub_uint32_t gen;
 142   grub_uint32_t kernel_flags;
 143   grub_uint32_t flags;
 144   grub_uint32_t extsz;
 145   grub_uint64_t ext[2];
 146   union
 147   {
 148     struct
 149     {
 150       grub_uint64_t dir_blocks[GRUB_UFS_DIRBLKS];
 151       grub_uint64_t indir_blocks[GRUB_UFS_INDIRBLKS];
 152     } blocks;
 153     grub_uint8_t symlink[(GRUB_UFS_DIRBLKS + GRUB_UFS_INDIRBLKS) * 8];
 154   };
 155
 156   grub_uint8_t unused[24];
 157 };
 158
 159 /* Directory entry.  */
 160 struct grub_ufs_dirent
 161 {
 162   grub_uint32_t ino;
 163   grub_uint16_t direntlen;
 164   grub_uint8_t filetype;
 165   grub_uint8_t namelen;
 166 };
 167
 168 /* Information about a "mounted" ufs filesystem.  */
 169 struct grub_ufs_data
 170 {
 171   struct grub_ufs_sblock sblock;
 172   grub_disk_t disk;
 173   union
 174   {
 175     struct grub_ufs_inode inode;
 176     struct grub_ufs2_inode inode2;
 177   };
 178   enum
 179     {
 180       UFS1,
 181       UFS2,
 182       UNKNOWN
 183     } ufs_type;
 184   int ino;
 185   int linknest;
 186 };
 187
 188 #ifndef GRUB_UTIL
 189 static grub_dl_t my_mod;
 190 #endif
 191 \f
 192 /* Forward declaration.  */
 193 static grub_err_t grub_ufs_find_file (struct grub_ufs_data *data,
 194                                       const char *path);
 195
 196
 197 static int
 198 grub_ufs_get_file_block (struct grub_ufs_data *data, unsigned int blk)
 199 {
 200   struct grub_ufs_sblock *sblock = &data->sblock;
 201   unsigned int indirsz;
 202
 203   /* Direct.  */
 204   if (blk < GRUB_UFS_DIRBLKS)
 205     return INODE_DIRBLOCKS (data, blk);
 206
 207   blk -= GRUB_UFS_DIRBLKS;
 208
 209   indirsz = UFS_BLKSZ (sblock) / INODE_BLKSZ (data);
 210   /* Single indirect block.  */
 211   if (blk < indirsz)
 212     {
 213       grub_uint32_t indir[UFS_BLKSZ (sblock)];
 214       grub_disk_read (data->disk, INODE_INDIRBLOCKS (data, 0),
 215                       0, sizeof (indir), (char *) indir);
 216       return indir[blk];
 217     }
 218   blk -= indirsz;
 219
 220   /* Double indirect block.  */
 221   if (blk < UFS_BLKSZ (sblock) / indirsz)
 222     {
 223       grub_uint32_t indir[UFS_BLKSZ (sblock)];
 224
 225       grub_disk_read (data->disk, INODE_INDIRBLOCKS (data, 1),
 226                       0, sizeof (indir), (char *) indir);
 227       grub_disk_read (data->disk,  indir[blk / indirsz],
 228                       0, sizeof (indir), (char *) indir);
 229
 230       return indir[blk % indirsz];
 231     }
 232
 233
 234   grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
 235               "ufs does not support tripple indirect blocks");
 236   return 0;
 237 }
 238
 239
 240 /* Read LEN bytes from the file described by DATA starting with byte
 241    POS.  Return the amount of read bytes in READ.  */
 242 static grub_ssize_t
 243 grub_ufs_read_file (struct grub_ufs_data *data,
 244                     void (*read_hook) (unsigned long sector,
 245                                        unsigned offset, unsigned length),
 246                     int pos, unsigned int len, char *buf)
 247 {
 248   struct grub_ufs_sblock *sblock = &data->sblock;
 249   int i;
 250   int blockcnt;
 251
 252   /* Adjust len so it we can't read past the end of the file.  */
 253   if (len > INODE_SIZE (data))
 254     len = INODE_SIZE (data);
 255
 256   blockcnt = (len + pos + UFS_BLKSZ (sblock) - 1) / UFS_BLKSZ (sblock);
 257
 258   for (i = pos / UFS_BLKSZ (sblock); i < blockcnt; i++)
 259     {
 260       int blknr;
 261       int blockoff = pos % UFS_BLKSZ (sblock);
 262       int blockend = UFS_BLKSZ (sblock);
 263
 264       int skipfirst = 0;
 265
 266       blknr = grub_ufs_get_file_block (data, i);
 267       if (grub_errno)
 268         return -1;
 269
 270       /* Last block.  */
 271       if (i == blockcnt - 1)
 272         {
 273           blockend = (len + pos) % UFS_BLKSZ (sblock);
 274
 275           if (!blockend)
 276             blockend = UFS_BLKSZ (sblock);
 277         }
 278
 279       /* First block.  */
 280       if (i == (pos / (int) UFS_BLKSZ (sblock)))
 281         {
 282           skipfirst = blockoff;
 283           blockend -= skipfirst;
 284         }
 285
 286       /* XXX: If the block number is 0 this block is not stored on
 287          disk but is zero filled instead.  */
 288       if (blknr)
 289         {
 290           data->disk->read_hook = read_hook;
 291           grub_disk_read (data->disk,
 292                           blknr << grub_le_to_cpu32 (data->sblock.log2_blksz),
 293                           skipfirst, blockend, buf);
 294           data->disk->read_hook = 0;
 295           if (grub_errno)
 296             return -1;
 297         }
 298       else
 299         grub_memset (buf, UFS_BLKSZ (sblock) - skipfirst, 0);
 300
 301       buf += UFS_BLKSZ (sblock) - skipfirst;
 302     }
 303
 304   return len;
 305 }
 306
 307
 308 /* Read inode INO from the mounted filesystem described by DATA.  This
 309    inode is used by default now.  */
 310 static grub_err_t
 311 grub_ufs_read_inode (struct grub_ufs_data *data, int ino)
 312 {
 313   struct grub_ufs_sblock *sblock = &data->sblock;
 314
 315   /* Determine the group the inode is in.  */
 316   int group = ino / grub_le_to_cpu32 (sblock->ino_per_group);
 317
 318   /* Determine the inode within the group.  */
 319   int grpino = ino % grub_le_to_cpu32 (sblock->ino_per_group);
 320
 321   /* The first block of the group.  */
 322   int grpblk = group * (grub_le_to_cpu32 (sblock->frags_per_group));
 323
 324   if (data->ufs_type == UFS1)
 325     {
 326       struct grub_ufs_inode *inode = &data->inode;
 327
 328       grub_disk_read (data->disk,
 329                       (((grub_le_to_cpu32 (sblock->inoblk_offs) + grpblk)
 330                         << grub_le_to_cpu32 (data->sblock.log2_blksz)))
 331                       + grpino / 4,
 332                       (grpino % 4) * sizeof (struct grub_ufs_inode),
 333                       sizeof (struct grub_ufs_inode),
 334                       (char *) inode);
 335     }
 336   else
 337     {
 338       struct grub_ufs2_inode *inode = &data->inode2;
 339
 340       grub_disk_read (data->disk,
 341                       (((grub_le_to_cpu32 (sblock->inoblk_offs) + grpblk)
 342                         << grub_le_to_cpu32 (data->sblock.log2_blksz)))
 343                       + grpino / 2,
 344                       (grpino % 2) * sizeof (struct grub_ufs2_inode),
 345                       sizeof (struct grub_ufs2_inode),
 346                       (char *) inode);
 347     }
 348
 349   data->ino = ino;
 350   return grub_errno;
 351 }
 352
 353
 354 /* Lookup the symlink the current inode points to.  INO is the inode
 355    number of the directory the symlink is relative to.  */
 356 static grub_err_t
 357 grub_ufs_lookup_symlink (struct grub_ufs_data *data, int ino)
 358 {
 359   char symlink[INODE_SIZE (data)];
 360
 361   if (++data->linknest > GRUB_UFS_MAX_SYMLNK_CNT)
 362     return grub_error (GRUB_ERR_SYMLINK_LOOP, "too deep nesting of symlinks");
 363
 364   if (INODE_SIZE (data) < (GRUB_UFS_DIRBLKS + GRUB_UFS_INDIRBLKS
 365                           * INODE_BLKSZ (data)))
 366     grub_strcpy (symlink, INODE (data, symlink));
 367   else
 368     {
 369       grub_disk_read (data->disk,
 370                       (INODE_DIRBLOCKS (data, 0)
 371                        << grub_le_to_cpu32 (data->sblock.log2_blksz)),
 372                       0, INODE_SIZE (data), symlink);
 373       symlink[INODE_SIZE (data)] = '\0';
 374     }
 375
 376   /* The symlink is an absolute path, go back to the root inode.  */
 377   if (symlink[0] == '/')
 378     ino = GRUB_UFS_INODE;
 379
 380   /* Now load in the old inode.  */
 381   if (grub_ufs_read_inode (data, ino))
 382     return grub_errno;
 383
 384   grub_ufs_find_file (data, symlink);
 385   if (grub_errno)
 386     grub_error (grub_errno, "Can not follow symlink `%s'.", symlink);
 387
 388   return grub_errno;
 389 }
 390
 391
 392 /* Find the file with the pathname PATH on the filesystem described by
 393    DATA.  */
 394 static grub_err_t
 395 grub_ufs_find_file (struct grub_ufs_data *data, const char *path)
 396 {
 397   char fpath[grub_strlen (path)];
 398   char *name = fpath;
 399   char *next;
 400   unsigned int pos = 0;
 401   int dirino;
 402
 403   grub_strncpy (fpath, path, grub_strlen (path));
 404
 405   /* Skip the first slash.  */
 406   if (name[0] == '/')
 407     {
 408       name++;
 409       if (!*name)
 410         return 0;
 411     }
 412
 413   /* Extract the actual part from the pathname.  */
 414   next = grub_strchr (name, '/');
 415   if (next)
 416     {
 417       next[0] = '\0';
 418       next++;
 419     }
 420
 421   do
 422     {
 423       struct grub_ufs_dirent dirent;
 424
 425       if (grub_strlen (name) == 0)
 426         return GRUB_ERR_NONE;
 427
 428       if (grub_ufs_read_file (data, 0, pos, sizeof (dirent),
 429                               (char *) &dirent) < 0)
 430         return grub_errno;
 431
 432       {
 433         char filename[dirent.namelen + 1];
 434
 435         if (grub_ufs_read_file (data, 0, pos + sizeof (dirent),
 436                                 dirent.namelen, filename) < 0)
 437           return grub_errno;
 438
 439         filename[dirent.namelen] = '\0';
 440
 441         if (!grub_strcmp (name, filename))
 442           {
 443             dirino = data->ino;
 444             grub_ufs_read_inode (data, grub_le_to_cpu32 (dirent.ino));
 445
 446             if (dirent.filetype == GRUB_UFS_FILETYPE_LNK)
 447               {
 448                 grub_ufs_lookup_symlink (data, dirino);
 449                 if (grub_errno)
 450                   return grub_errno;
 451               }
 452
 453             if (!next)
 454               return 0;
 455
 456             pos = 0;
 457
 458             name = next;
 459             next = grub_strchr (name, '/');
 460             if (next)
 461               {
 462                 next[0] = '\0';
 463                 next++;
 464               }
 465
 466             if (!(dirent.filetype & GRUB_UFS_FILETYPE_DIR))
 467               return grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a directory");
 468
 469             continue;
 470           }
 471       }
 472
 473       pos += grub_le_to_cpu16 (dirent.direntlen);
 474     } while (pos < grub_le_to_cpu32 (INODE_SIZE (data)));
 475
 476   grub_error (GRUB_ERR_FILE_NOT_FOUND, "file not found");
 477   return grub_errno;
 478 }
 479
 480
 481 /* Mount the filesystem on the disk DISK.  */
 482 static struct grub_ufs_data *
 483 grub_ufs_mount (grub_disk_t disk)
 484 {
 485   struct grub_ufs_data *data;
 486   int *sblklist = sblocklist;
 487
 488   data = grub_malloc (sizeof (struct grub_ufs_data));
 489   if (!data)
 490     return 0;
 491
 492   /* Find a UFS1 or UFS2 sblock.  */
 493   data->ufs_type = UNKNOWN;
 494   while (*sblklist != -1)
 495     {
 496       grub_disk_read (disk, *sblklist, 0, sizeof (struct grub_ufs_sblock),
 497                       (char *) &data->sblock);
 498       if (grub_errno)
 499         goto fail;
 500
 501       if (grub_le_to_cpu32 (data->sblock.magic) == GRUB_UFS_MAGIC)
 502         {
 503           data->ufs_type = UFS1;
 504           break;
 505         }
 506       else if (grub_le_to_cpu32 (data->sblock.magic) == GRUB_UFS2_MAGIC)
 507         {
 508           data->ufs_type = UFS2;
 509           break;
 510         }
 511       sblklist++;
 512     }
 513   if (data->ufs_type == UNKNOWN)
 514     {
 515       grub_error (GRUB_ERR_BAD_FS, "not an ufs filesystem");
 516       goto fail;
 517     }
 518
 519   data->disk = disk;
 520   data->linknest = 0;
 521   return data;
 522
 523  fail:
 524   grub_free (data);
 525
 526   if (grub_errno == GRUB_ERR_OUT_OF_RANGE)
 527     grub_error (GRUB_ERR_BAD_FS, "not a ufs filesystem");
 528
 529   return 0;
 530 }
 531
 532
 533 static grub_err_t
 534 grub_ufs_dir (grub_device_t device, const char *path,
 535                int (*hook) (const char *filename, int dir))
 536 {
 537   struct grub_ufs_data *data;
 538   struct grub_ufs_sblock *sblock;
 539   unsigned int pos = 0;
 540
 541   data = grub_ufs_mount (device->disk);
 542   if (!data)
 543     return grub_errno;
 544
 545   grub_ufs_read_inode (data, GRUB_UFS_INODE);
 546   if (grub_errno)
 547     return grub_errno;
 548
 549   sblock = &data->sblock;
 550
 551   if (!path || path[0] != '/')
 552     {
 553       grub_error (GRUB_ERR_BAD_FILENAME, "bad filename");
 554       return grub_errno;
 555     }
 556
 557   grub_ufs_find_file (data, path);
 558   if (grub_errno)
 559     goto fail;
 560
 561   if (!(INODE_MODE (data) & GRUB_UFS_ATTR_DIR))
 562     {
 563       grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a directory");
 564       goto fail;
 565     }
 566
 567   while (pos < INODE_SIZE (data))
 568     {
 569       struct grub_ufs_dirent dirent;
 570
 571       if (grub_ufs_read_file (data, 0, pos, sizeof (dirent),
 572                               (char *) &dirent) < 0)
 573         break;
 574
 575       {
 576         char filename[dirent.namelen + 1];
 577
 578         if (grub_ufs_read_file (data, 0, pos + sizeof (dirent),
 579                                 dirent.namelen, filename) < 0)
 580           break;
 581
 582         filename[dirent.namelen] = '\0';
 583         if (hook (filename, dirent.filetype == GRUB_UFS_FILETYPE_DIR))
 584           break;
 585       }
 586
 587       pos += grub_le_to_cpu16 (dirent.direntlen);
 588     }
 589
 590  fail:
 591   grub_free (data);
 592
 593   return grub_errno;
 594 }
 595
 596
 597 /* Open a file named NAME and initialize FILE.  */
 598 static grub_err_t
 599 grub_ufs_open (struct grub_file *file, const char *name)
 600 {
 601   struct grub_ufs_data *data;
 602   data = grub_ufs_mount (file->device->disk);
 603   if (!data)
 604     return grub_errno;
 605
 606   grub_ufs_read_inode (data, 2);
 607   if (grub_errno)
 608     {
 609       grub_free (data);
 610       return grub_errno;
 611     }
 612
 613   if (!name || name[0] != '/')
 614     {
 615       grub_error (GRUB_ERR_BAD_FILENAME, "bad filename");
 616       return grub_errno;
 617     }
 618
 619   grub_ufs_find_file (data, name);
 620   if (grub_errno)
 621     {
 622       grub_free (data);
 623       return grub_errno;
 624     }
 625
 626   file->data = data;
 627   file->size = INODE_SIZE (data);
 628
 629   return GRUB_ERR_NONE;
 630 }
 631
 632
 633 static grub_ssize_t
 634 grub_ufs_read (grub_file_t file, char *buf, grub_ssize_t len)
 635 {
 636   struct grub_ufs_data *data =
 637     (struct grub_ufs_data *) file->data;
 638
 639   return grub_ufs_read_file (data, file->read_hook, file->offset, len, buf);
 640 }
 641
 642
 643 static grub_err_t
 644 grub_ufs_close (grub_file_t file)
 645 {
 646   grub_free (file->data);
 647
 648   return GRUB_ERR_NONE;
 649 }
 650
 651
 652 static grub_err_t
 653 grub_ufs_label (grub_device_t device __attribute ((unused)),
 654                 char **label __attribute ((unused)))
 655 {
 656   return GRUB_ERR_NONE;
 657 }
 658
 659 \f
 660 static struct grub_fs grub_ufs_fs =
 661   {
 662     .name = "ufs",
 663     .dir = grub_ufs_dir,
 664     .open = grub_ufs_open,
 665     .read = grub_ufs_read,
 666     .close = grub_ufs_close,
 667     .label = grub_ufs_label,
 668     .next = 0
 669   };
 670
 671 GRUB_MOD_INIT(ufs)
 672 {
 673   grub_fs_register (&grub_ufs_fs);
 674 #ifndef GRUB_UTIL
 675   my_mod = mod;
 676 #endif
 677 }
 678
 679 GRUB_MOD_FINI(ufs)
 680 {
 681   grub_fs_unregister (&grub_ufs_fs);
 682 }
 683