fs/ext2/ext2fs.c

   1 /*
   2  * (C) Copyright 2004
   3  *  esd gmbh <www.esd-electronics.com>
   4  *  Reinhard Arlt <reinhard.arlt@esd-electronics.com>
   5  *
   6  *  based on code from grub2 fs/ext2.c and fs/fshelp.c by
   7  *
   8  *  GRUB  --  GRand Unified Bootloader
   9  *  Copyright (C) 2003, 2004  Free Software Foundation, Inc.
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License as published by
  13  *  the Free Software Foundation; either version 2 of the License, or
  14  *  (at your option) any later version.
  15  *
  16  *  This program is distributed in the hope that it will be useful,
  17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  *  GNU General Public License for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License
  22  *  along with this program; if not, write to the Free Software
  23  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  */
  25
  26 #include <common.h>
  27 #include <ext2fs.h>
  28 #include <malloc.h>
  29 #include <asm/byteorder.h>
  30
  31 extern int ext2fs_devread (int sector, int byte_offset, int byte_len,
  32                            char *buf);
  33
  34 /* Magic value used to identify an ext2 filesystem.  */
  35 #define EXT2_MAGIC              0xEF53
  36 /* Amount of indirect blocks in an inode.  */
  37 #define INDIRECT_BLOCKS         12
  38 /* Maximum lenght of a pathname.  */
  39 #define EXT2_PATH_MAX           4096
  40 /* Maximum nesting of symlinks, used to prevent a loop.  */
  41 #define EXT2_MAX_SYMLINKCNT     8
  42
  43 /* Filetype used in directory entry.  */
  44 #define FILETYPE_UNKNOWN        0
  45 #define FILETYPE_REG            1
  46 #define FILETYPE_DIRECTORY      2
  47 #define FILETYPE_SYMLINK        7
  48
  49 /* Filetype information as used in inodes.  */
  50 #define FILETYPE_INO_MASK       0170000
  51 #define FILETYPE_INO_REG        0100000
  52 #define FILETYPE_INO_DIRECTORY  0040000
  53 #define FILETYPE_INO_SYMLINK    0120000
  54
  55 /* Bits used as offset in sector */
  56 #define DISK_SECTOR_BITS        9
  57
  58 /* Log2 size of ext2 block in 512 blocks.  */
  59 #define LOG2_EXT2_BLOCK_SIZE(data) (__le32_to_cpu (data->sblock.log2_block_size) + 1)
  60
  61 /* Log2 size of ext2 block in bytes.  */
  62 #define LOG2_BLOCK_SIZE(data)      (__le32_to_cpu (data->sblock.log2_block_size) + 10)
  63
  64 /* The size of an ext2 block in bytes.  */
  65 #define EXT2_BLOCK_SIZE(data)      (1 << LOG2_BLOCK_SIZE(data))
  66
  67 /* The ext2 superblock.  */
  68 struct ext2_sblock {
  69         uint32_t total_inodes;
  70         uint32_t total_blocks;
  71         uint32_t reserved_blocks;
  72         uint32_t free_blocks;
  73         uint32_t free_inodes;
  74         uint32_t first_data_block;
  75         uint32_t log2_block_size;
  76         uint32_t log2_fragment_size;
  77         uint32_t blocks_per_group;
  78         uint32_t fragments_per_group;
  79         uint32_t inodes_per_group;
  80         uint32_t mtime;
  81         uint32_t utime;
  82         uint16_t mnt_count;
  83         uint16_t max_mnt_count;
  84         uint16_t magic;
  85         uint16_t fs_state;
  86         uint16_t error_handling;
  87         uint16_t minor_revision_level;
  88         uint32_t lastcheck;
  89         uint32_t checkinterval;
  90         uint32_t creator_os;
  91         uint32_t revision_level;
  92         uint16_t uid_reserved;
  93         uint16_t gid_reserved;
  94         uint32_t first_inode;
  95         uint16_t inode_size;
  96         uint16_t block_group_number;
  97         uint32_t feature_compatibility;
  98         uint32_t feature_incompat;
  99         uint32_t feature_ro_compat;
 100         uint32_t unique_id[4];
 101         char volume_name[16];
 102         char last_mounted_on[64];
 103         uint32_t compression_info;
 104 };
 105
 106 /* The ext2 blockgroup.  */
 107 struct ext2_block_group {
 108         uint32_t block_id;
 109         uint32_t inode_id;
 110         uint32_t inode_table_id;
 111         uint16_t free_blocks;
 112         uint16_t free_inodes;
 113         uint16_t used_dir_cnt;
 114         uint32_t reserved[3];
 115 };
 116
 117 /* The ext2 inode.  */
 118 struct ext2_inode {
 119         uint16_t mode;
 120         uint16_t uid;
 121         uint32_t size;
 122         uint32_t atime;
 123         uint32_t ctime;
 124         uint32_t mtime;
 125         uint32_t dtime;
 126         uint16_t gid;
 127         uint16_t nlinks;
 128         uint32_t blockcnt;      /* Blocks of 512 bytes!! */
 129         uint32_t flags;
 130         uint32_t osd1;
 131         union {
 132                 struct datablocks {
 133                         uint32_t dir_blocks[INDIRECT_BLOCKS];
 134                         uint32_t indir_block;
 135                         uint32_t double_indir_block;
 136                         uint32_t tripple_indir_block;
 137                 } blocks;
 138                 char symlink[60];
 139         } b;
 140         uint32_t version;
 141         uint32_t acl;
 142         uint32_t dir_acl;
 143         uint32_t fragment_addr;
 144         uint32_t osd2[3];
 145 };
 146
 147 /* The header of an ext2 directory entry.  */
 148 struct ext2_dirent {
 149         uint32_t inode;
 150         uint16_t direntlen;
 151         uint8_t namelen;
 152         uint8_t filetype;
 153 };
 154
 155 struct ext2fs_node {
 156         struct ext2_data *data;
 157         struct ext2_inode inode;
 158         int ino;
 159         int inode_read;
 160 };
 161
 162 /* Information about a "mounted" ext2 filesystem.  */
 163 struct ext2_data {
 164         struct ext2_sblock sblock;
 165         struct ext2_inode *inode;
 166         struct ext2fs_node diropen;
 167 };
 168
 169
 170 typedef struct ext2fs_node *ext2fs_node_t;
 171
 172 struct ext2_data *ext2fs_root = NULL;
 173 ext2fs_node_t ext2fs_file = NULL;
 174 int symlinknest = 0;
 175 uint32_t *indir1_block = NULL;
 176 int indir1_size = 0;
 177 int indir1_blkno = -1;
 178 uint32_t *indir2_block = NULL;
 179 int indir2_size = 0;
 180 int indir2_blkno = -1;
 181
 182
 183 static int ext2fs_blockgroup
 184         (struct ext2_data *data, int group, struct ext2_block_group *blkgrp) {
 185         unsigned int blkno;
 186         unsigned int blkoff;
 187         unsigned int desc_per_blk;
 188
 189         desc_per_blk = EXT2_BLOCK_SIZE(data) / sizeof(struct ext2_block_group);
 190
 191         blkno = __le32_to_cpu(data->sblock.first_data_block) + 1 +
 192         group / desc_per_blk;
 193         blkoff = (group % desc_per_blk) * sizeof(struct ext2_block_group);
 194 #ifdef DEBUG
 195         printf ("ext2fs read %d group descriptor (blkno %d blkoff %d)\n",
 196                 group, blkno, blkoff);
 197 #endif
 198         return (ext2fs_devread (blkno << LOG2_EXT2_BLOCK_SIZE(data),
 199                 blkoff, sizeof(struct ext2_block_group), (char *)blkgrp));
 200
 201 }
 202
 203
 204 static int ext2fs_read_inode
 205         (struct ext2_data *data, int ino, struct ext2_inode *inode) {
 206         struct ext2_block_group blkgrp;
 207         struct ext2_sblock *sblock = &data->sblock;
 208         int inodes_per_block;
 209         int status;
 210
 211         unsigned int blkno;
 212         unsigned int blkoff;
 213
 214 #ifdef DEBUG
 215         printf ("ext2fs read inode %d\n", ino);
 216 #endif
 217         /* It is easier to calculate if the first inode is 0.  */
 218         ino--;
 219         status = ext2fs_blockgroup (data, ino / __le32_to_cpu
 220                                     (sblock->inodes_per_group), &blkgrp);
 221         if (status == 0) {
 222                 return (0);
 223         }
 224
 225         inodes_per_block = EXT2_BLOCK_SIZE(data) / __le16_to_cpu(sblock->inode_size);
 226
 227 #ifdef DEBUG
 228         printf ("ext2fs read inode blkno %d blkoff %d\n", blkno, blkoff);
 229 #endif
 230
 231         blkno = __le32_to_cpu (blkgrp.inode_table_id) +
 232                 (ino % __le32_to_cpu (sblock->inodes_per_group))
 233                 / inodes_per_block;
 234         blkoff = (ino % inodes_per_block) * __le16_to_cpu (sblock->inode_size);
 235 #ifdef DEBUG
 236         printf ("ext2fs read inode blkno %d blkoff %d\n", blkno, blkoff);
 237 #endif
 238         /* Read the inode.  */
 239         status = ext2fs_devread (blkno << LOG2_EXT2_BLOCK_SIZE (data), blkoff,
 240                                  sizeof (struct ext2_inode), (char *) inode);
 241         if (status == 0) {
 242                 return (0);
 243         }
 244
 245         return (1);
 246 }
 247
 248
 249 void ext2fs_free_node (ext2fs_node_t node, ext2fs_node_t currroot) {
 250         if ((node != &ext2fs_root->diropen) && (node != currroot)) {
 251                 free (node);
 252         }
 253 }
 254
 255
 256 static int ext2fs_read_block (ext2fs_node_t node, int fileblock) {
 257         struct ext2_data *data = node->data;
 258         struct ext2_inode *inode = &node->inode;
 259         int blknr;
 260         int blksz = EXT2_BLOCK_SIZE (data);
 261         int log2_blksz = LOG2_EXT2_BLOCK_SIZE (data);
 262         int status;
 263
 264         /* Direct blocks.  */
 265         if (fileblock < INDIRECT_BLOCKS) {
 266                 blknr = __le32_to_cpu (inode->b.blocks.dir_blocks[fileblock]);
 267         }
 268         /* Indirect.  */
 269         else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4))) {
 270                 if (indir1_block == NULL) {
 271                         indir1_block = (uint32_t *) malloc (blksz);
 272                         if (indir1_block == NULL) {
 273                                 printf ("** ext2fs read block (indir 1) malloc failed. **\n");
 274                                 return (-1);
 275                         }
 276                         indir1_size = blksz;
 277                         indir1_blkno = -1;
 278                 }
 279                 if (blksz != indir1_size) {
 280                         free (indir1_block);
 281                         indir1_block = NULL;
 282                         indir1_size = 0;
 283                         indir1_blkno = -1;
 284                         indir1_block = (uint32_t *) malloc (blksz);
 285                         if (indir1_block == NULL) {
 286                                 printf ("** ext2fs read block (indir 1) malloc failed. **\n");
 287                                 return (-1);
 288                         }
 289                         indir1_size = blksz;
 290                 }
 291                 if ((__le32_to_cpu (inode->b.blocks.indir_block) <<
 292                      log2_blksz) != indir1_blkno) {
 293                         status = ext2fs_devread (__le32_to_cpu(inode->b.blocks.indir_block) << log2_blksz,
 294                                                  0, blksz,
 295                                                  (char *) indir1_block);
 296                         if (status == 0) {
 297                                 printf ("** ext2fs read block (indir 1) failed. **\n");
 298                                 return (0);
 299                         }
 300                         indir1_blkno =
 301                                 __le32_to_cpu (inode->b.blocks.
 302                                                indir_block) << log2_blksz;
 303                 }
 304                 blknr = __le32_to_cpu (indir1_block
 305                                        [fileblock - INDIRECT_BLOCKS]);
 306         }
 307         /* Double indirect.  */
 308         else if (fileblock <
 309                  (INDIRECT_BLOCKS + (blksz / 4 * (blksz / 4 + 1)))) {
 310                 unsigned int perblock = blksz / 4;
 311                 unsigned int rblock = fileblock - (INDIRECT_BLOCKS
 312                                                    + blksz / 4);
 313
 314                 if (indir1_block == NULL) {
 315                         indir1_block = (uint32_t *) malloc (blksz);
 316                         if (indir1_block == NULL) {
 317                                 printf ("** ext2fs read block (indir 2 1) malloc failed. **\n");
 318                                 return (-1);
 319                         }
 320                         indir1_size = blksz;
 321                         indir1_blkno = -1;
 322                 }
 323                 if (blksz != indir1_size) {
 324                         free (indir1_block);
 325                         indir1_block = NULL;
 326                         indir1_size = 0;
 327                         indir1_blkno = -1;
 328                         indir1_block = (uint32_t *) malloc (blksz);
 329                         if (indir1_block == NULL) {
 330                                 printf ("** ext2fs read block (indir 2 1) malloc failed. **\n");
 331                                 return (-1);
 332                         }
 333                         indir1_size = blksz;
 334                 }
 335                 if ((__le32_to_cpu (inode->b.blocks.double_indir_block) <<
 336                      log2_blksz) != indir1_blkno) {
 337                         status = ext2fs_devread (__le32_to_cpu(inode->b.blocks.double_indir_block) << log2_blksz,
 338                                                 0, blksz,
 339                                                 (char *) indir1_block);
 340                         if (status == 0) {
 341                                 printf ("** ext2fs read block (indir 2 1) failed. **\n");
 342                                 return (-1);
 343                         }
 344                         indir1_blkno =
 345                                 __le32_to_cpu (inode->b.blocks.double_indir_block) << log2_blksz;
 346                 }
 347
 348                 if (indir2_block == NULL) {
 349                         indir2_block = (uint32_t *) malloc (blksz);
 350                         if (indir2_block == NULL) {
 351                                 printf ("** ext2fs read block (indir 2 2) malloc failed. **\n");
 352                                 return (-1);
 353                         }
 354                         indir2_size = blksz;
 355                         indir2_blkno = -1;
 356                 }
 357                 if (blksz != indir2_size) {
 358                         free (indir2_block);
 359                         indir2_block = NULL;
 360                         indir2_size = 0;
 361                         indir2_blkno = -1;
 362                         indir2_block = (uint32_t *) malloc (blksz);
 363                         if (indir2_block == NULL) {
 364                                 printf ("** ext2fs read block (indir 2 2) malloc failed. **\n");
 365                                 return (-1);
 366                         }
 367                         indir2_size = blksz;
 368                 }
 369                 if ((__le32_to_cpu (indir1_block[rblock / perblock]) <<
 370                      log2_blksz) != indir1_blkno) {
 371                         status = ext2fs_devread (__le32_to_cpu(indir1_block[rblock / perblock]) << log2_blksz,
 372                                                  0, blksz,
 373                                                  (char *) indir2_block);
 374                         if (status == 0) {
 375                                 printf ("** ext2fs read block (indir 2 2) failed. **\n");
 376                                 return (-1);
 377                         }
 378                         indir2_blkno =
 379                                 __le32_to_cpu (indir1_block[rblock / perblock]) << log2_blksz;
 380                 }
 381                 blknr = __le32_to_cpu (indir2_block[rblock % perblock]);
 382         }
 383         /* Tripple indirect.  */
 384         else {
 385                 printf ("** ext2fs doesn't support tripple indirect blocks. **\n");
 386                 return (-1);
 387         }
 388 #ifdef DEBUG
 389         printf ("ext2fs_read_block %08x\n", blknr);
 390 #endif
 391         return (blknr);
 392 }
 393
 394
 395 int ext2fs_read_file
 396         (ext2fs_node_t node, int pos, unsigned int len, char *buf) {
 397         int i;
 398         int blockcnt;
 399         int log2blocksize = LOG2_EXT2_BLOCK_SIZE (node->data);
 400         int blocksize = 1 << (log2blocksize + DISK_SECTOR_BITS);
 401         unsigned int filesize = __le32_to_cpu(node->inode.size);
 402
 403         /* Adjust len so it we can't read past the end of the file.  */
 404         if (len > filesize) {
 405                 len = filesize;
 406         }
 407         blockcnt = ((len + pos) + blocksize - 1) / blocksize;
 408
 409         for (i = pos / blocksize; i < blockcnt; i++) {
 410                 int blknr;
 411                 int blockoff = pos % blocksize;
 412                 int blockend = blocksize;
 413
 414                 int skipfirst = 0;
 415
 416                 blknr = ext2fs_read_block (node, i);
 417                 if (blknr < 0) {
 418                         return (-1);
 419                 }
 420                 blknr = blknr << log2blocksize;
 421
 422                 /* Last block.  */
 423                 if (i == blockcnt - 1) {
 424                         blockend = (len + pos) % blocksize;
 425
 426                         /* The last portion is exactly blocksize.  */
 427                         if (!blockend) {
 428                                 blockend = blocksize;
 429                         }
 430                 }
 431
 432                 /* First block.  */
 433                 if (i == pos / blocksize) {
 434                         skipfirst = blockoff;
 435                         blockend -= skipfirst;
 436                 }
 437
 438                 /* If the block number is 0 this block is not stored on disk but
 439                    is zero filled instead.  */
 440                 if (blknr) {
 441                         int status;
 442
 443                         status = ext2fs_devread (blknr, skipfirst, blockend, buf);
 444                         if (status == 0) {
 445                                 return (-1);
 446                         }
 447                 } else {
 448                         memset (buf, 0, blocksize - skipfirst);
 449                 }
 450                 buf += blocksize - skipfirst;
 451         }
 452         return (len);
 453 }
 454
 455
 456 static int ext2fs_iterate_dir (ext2fs_node_t dir, char *name, ext2fs_node_t * fnode, int *ftype)
 457 {
 458         unsigned int fpos = 0;
 459         int status;
 460         struct ext2fs_node *diro = (struct ext2fs_node *) dir;
 461
 462 #ifdef DEBUG
 463         if (name != NULL)
 464                 printf ("Iterate dir %s\n", name);
 465 #endif /* of DEBUG */
 466         if (!diro->inode_read) {
 467                 status = ext2fs_read_inode (diro->data, diro->ino,
 468                                             &diro->inode);
 469                 if (status == 0) {
 470                         return (0);
 471                 }
 472         }
 473         /* Search the file.  */
 474         while (fpos < __le32_to_cpu (diro->inode.size)) {
 475                 struct ext2_dirent dirent;
 476
 477                 status = ext2fs_read_file (diro, fpos,
 478                                            sizeof (struct ext2_dirent),
 479                                            (char *) &dirent);
 480                 if (status < 1) {
 481                         return (0);
 482                 }
 483                 if (dirent.namelen != 0) {
 484                         char filename[dirent.namelen + 1];
 485                         ext2fs_node_t fdiro;
 486                         int type = FILETYPE_UNKNOWN;
 487
 488                         status = ext2fs_read_file (diro,
 489                                                    fpos + sizeof (struct ext2_dirent),
 490                                                    dirent.namelen, filename);
 491                         if (status < 1) {
 492                                 return (0);
 493                         }
 494                         fdiro = malloc (sizeof (struct ext2fs_node));
 495                         if (!fdiro) {
 496                                 return (0);
 497                         }
 498
 499                         fdiro->data = diro->data;
 500                         fdiro->ino = __le32_to_cpu (dirent.inode);
 501
 502                         filename[dirent.namelen] = '\0';
 503
 504                         if (dirent.filetype != FILETYPE_UNKNOWN) {
 505                                 fdiro->inode_read = 0;
 506
 507                                 if (dirent.filetype == FILETYPE_DIRECTORY) {
 508                                         type = FILETYPE_DIRECTORY;
 509                                 } else if (dirent.filetype ==
 510                                            FILETYPE_SYMLINK) {
 511                                         type = FILETYPE_SYMLINK;
 512                                 } else if (dirent.filetype == FILETYPE_REG) {
 513                                         type = FILETYPE_REG;
 514                                 }
 515                         } else {
 516                                 /* The filetype can not be read from the dirent, get it from inode */
 517
 518                                 status = ext2fs_read_inode (diro->data,
 519                                                             __le32_to_cpu(dirent.inode),
 520                                                             &fdiro->inode);
 521                                 if (status == 0) {
 522                                         free (fdiro);
 523                                         return (0);
 524                                 }
 525                                 fdiro->inode_read = 1;
 526
 527                                 if ((__le16_to_cpu (fdiro->inode.mode) &
 528                                      FILETYPE_INO_MASK) ==
 529                                     FILETYPE_INO_DIRECTORY) {
 530                                         type = FILETYPE_DIRECTORY;
 531                                 } else if ((__le16_to_cpu (fdiro->inode.mode)
 532                                             & FILETYPE_INO_MASK) ==
 533                                            FILETYPE_INO_SYMLINK) {
 534                                         type = FILETYPE_SYMLINK;
 535                                 } else if ((__le16_to_cpu (fdiro->inode.mode)
 536                                             & FILETYPE_INO_MASK) ==
 537                                            FILETYPE_INO_REG) {
 538                                         type = FILETYPE_REG;
 539                                 }
 540                         }
 541 #ifdef DEBUG
 542                         printf ("iterate >%s<\n", filename);
 543 #endif /* of DEBUG */
 544                         if ((name != NULL) && (fnode != NULL)
 545                             && (ftype != NULL)) {
 546                                 if (strcmp (filename, name) == 0) {
 547                                         *ftype = type;
 548                                         *fnode = fdiro;
 549                                         return (1);
 550                                 }
 551                         } else {
 552                                 if (fdiro->inode_read == 0) {
 553                                         status = ext2fs_read_inode (diro->data,
 554                                                             __le32_to_cpu (dirent.inode),
 555                                                             &fdiro->inode);
 556                                         if (status == 0) {
 557                                                 free (fdiro);
 558                                                 return (0);
 559                                         }
 560                                         fdiro->inode_read = 1;
 561                                 }
 562                                 switch (type) {
 563                                 case FILETYPE_DIRECTORY:
 564                                         printf ("<DIR> ");
 565                                         break;
 566                                 case FILETYPE_SYMLINK:
 567                                         printf ("<SYM> ");
 568                                         break;
 569                                 case FILETYPE_REG:
 570                                         printf ("      ");
 571                                         break;
 572                                 default:
 573                                         printf ("< ? > ");
 574                                         break;
 575                                 }
 576                                 printf ("%10d %s\n",
 577                                         __le32_to_cpu (fdiro->inode.size),
 578                                         filename);
 579                         }
 580                         free (fdiro);
 581                 }
 582                 fpos += __le16_to_cpu (dirent.direntlen);
 583         }
 584         return (0);
 585 }
 586
 587
 588 static char *ext2fs_read_symlink (ext2fs_node_t node) {
 589         char *symlink;
 590         struct ext2fs_node *diro = node;
 591         int status;
 592
 593         if (!diro->inode_read) {
 594                 status = ext2fs_read_inode (diro->data, diro->ino,
 595                                             &diro->inode);
 596                 if (status == 0) {
 597                         return (0);
 598                 }
 599         }
 600         symlink = malloc (__le32_to_cpu (diro->inode.size) + 1);
 601         if (!symlink) {
 602                 return (0);
 603         }
 604         /* If the filesize of the symlink is bigger than
 605            60 the symlink is stored in a separate block,
 606            otherwise it is stored in the inode.  */
 607         if (__le32_to_cpu (diro->inode.size) <= 60) {
 608                 strncpy (symlink, diro->inode.b.symlink,
 609                          __le32_to_cpu (diro->inode.size));
 610         } else {
 611                 status = ext2fs_read_file (diro, 0,
 612                                            __le32_to_cpu (diro->inode.size),
 613                                            symlink);
 614                 if (status == 0) {
 615                         free (symlink);
 616                         return (0);
 617                 }
 618         }
 619         symlink[__le32_to_cpu (diro->inode.size)] = '\0';
 620         return (symlink);
 621 }
 622
 623
 624 int ext2fs_find_file1
 625         (const char *currpath,
 626          ext2fs_node_t currroot, ext2fs_node_t * currfound, int *foundtype) {
 627         char fpath[strlen (currpath) + 1];
 628         char *name = fpath;
 629         char *next;
 630         int status;
 631         int type = FILETYPE_DIRECTORY;
 632         ext2fs_node_t currnode = currroot;
 633         ext2fs_node_t oldnode = currroot;
 634
 635         strncpy (fpath, currpath, strlen (currpath) + 1);
 636
 637         /* Remove all leading slashes.  */
 638         while (*name == '/') {
 639                 name++;
 640         }
 641         if (!*name) {
 642                 *currfound = currnode;
 643                 return (1);
 644         }
 645
 646         for (;;) {
 647                 int found;
 648
 649                 /* Extract the actual part from the pathname.  */
 650                 next = strchr (name, '/');
 651                 if (next) {
 652                         /* Remove all leading slashes.  */
 653                         while (*next == '/') {
 654                                 *(next++) = '\0';
 655                         }
 656                 }
 657
 658                 /* At this point it is expected that the current node is a directory, check if this is true.  */
 659                 if (type != FILETYPE_DIRECTORY) {
 660                         ext2fs_free_node (currnode, currroot);
 661                         return (0);
 662                 }
 663
 664                 oldnode = currnode;
 665
 666                 /* Iterate over the directory.  */
 667                 found = ext2fs_iterate_dir (currnode, name, &currnode, &type);
 668                 if (found == 0) {
 669                         return (0);
 670                 }
 671                 if (found == -1) {
 672                         break;
 673                 }
 674
 675                 /* Read in the symlink and follow it.  */
 676                 if (type == FILETYPE_SYMLINK) {
 677                         char *symlink;
 678
 679                         /* Test if the symlink does not loop.  */
 680                         if (++symlinknest == 8) {
 681                                 ext2fs_free_node (currnode, currroot);
 682                                 ext2fs_free_node (oldnode, currroot);
 683                                 return (0);
 684                         }
 685
 686                         symlink = ext2fs_read_symlink (currnode);
 687                         ext2fs_free_node (currnode, currroot);
 688
 689                         if (!symlink) {
 690                                 ext2fs_free_node (oldnode, currroot);
 691                                 return (0);
 692                         }
 693 #ifdef DEBUG
 694                         printf ("Got symlink >%s<\n", symlink);
 695 #endif /* of DEBUG */
 696                         /* The symlink is an absolute path, go back to the root inode.  */
 697                         if (symlink[0] == '/') {
 698                                 ext2fs_free_node (oldnode, currroot);
 699                                 oldnode = &ext2fs_root->diropen;
 700                         }
 701
 702                         /* Lookup the node the symlink points to.  */
 703                         status = ext2fs_find_file1 (symlink, oldnode,
 704                                                     &currnode, &type);
 705
 706                         free (symlink);
 707
 708                         if (status == 0) {
 709                                 ext2fs_free_node (oldnode, currroot);
 710                                 return (0);
 711                         }
 712                 }
 713
 714                 ext2fs_free_node (oldnode, currroot);
 715
 716                 /* Found the node!  */
 717                 if (!next || *next == '\0') {
 718                         *currfound = currnode;
 719                         *foundtype = type;
 720                         return (1);
 721                 }
 722                 name = next;
 723         }
 724         return (-1);
 725 }
 726
 727
 728 int ext2fs_find_file
 729         (const char *path,
 730          ext2fs_node_t rootnode, ext2fs_node_t * foundnode, int expecttype) {
 731         int status;
 732         int foundtype = FILETYPE_DIRECTORY;
 733
 734
 735         symlinknest = 0;
 736         if (!path) {
 737                 return (0);
 738         }
 739
 740         status = ext2fs_find_file1 (path, rootnode, foundnode, &foundtype);
 741         if (status == 0) {
 742                 return (0);
 743         }
 744         /* Check if the node that was found was of the expected type.  */
 745         if ((expecttype == FILETYPE_REG) && (foundtype != expecttype)) {
 746                 return (0);
 747         } else if ((expecttype == FILETYPE_DIRECTORY)
 748                    && (foundtype != expecttype)) {
 749                 return (0);
 750         }
 751         return (1);
 752 }
 753
 754
 755 int ext2fs_ls (char *dirname) {
 756         ext2fs_node_t dirnode;
 757         int status;
 758
 759         if (ext2fs_root == NULL) {
 760                 return (0);
 761         }
 762
 763         status = ext2fs_find_file (dirname, &ext2fs_root->diropen, &dirnode,
 764                                    FILETYPE_DIRECTORY);
 765         if (status != 1) {
 766                 printf ("** Can not find directory. **\n");
 767                 return (1);
 768         }
 769         ext2fs_iterate_dir (dirnode, NULL, NULL, NULL);
 770         ext2fs_free_node (dirnode, &ext2fs_root->diropen);
 771         return (0);
 772 }
 773
 774
 775 int ext2fs_open (char *filename) {
 776         ext2fs_node_t fdiro = NULL;
 777         int status;
 778         int len;
 779
 780         if (ext2fs_root == NULL) {
 781                 return (-1);
 782         }
 783         ext2fs_file = NULL;
 784         status = ext2fs_find_file (filename, &ext2fs_root->diropen, &fdiro,
 785                                    FILETYPE_REG);
 786         if (status == 0) {
 787                 goto fail;
 788         }
 789         if (!fdiro->inode_read) {
 790                 status = ext2fs_read_inode (fdiro->data, fdiro->ino,
 791                                             &fdiro->inode);
 792                 if (status == 0) {
 793                         goto fail;
 794                 }
 795         }
 796         len = __le32_to_cpu (fdiro->inode.size);
 797         ext2fs_file = fdiro;
 798         return (len);
 799
 800 fail:
 801         ext2fs_free_node (fdiro, &ext2fs_root->diropen);
 802         return (-1);
 803 }
 804
 805
 806 int ext2fs_close (void
 807         ) {
 808         if ((ext2fs_file != NULL) && (ext2fs_root != NULL)) {
 809                 ext2fs_free_node (ext2fs_file, &ext2fs_root->diropen);
 810                 ext2fs_file = NULL;
 811         }
 812         if (ext2fs_root != NULL) {
 813                 free (ext2fs_root);
 814                 ext2fs_root = NULL;
 815         }
 816         if (indir1_block != NULL) {
 817                 free (indir1_block);
 818                 indir1_block = NULL;
 819                 indir1_size = 0;
 820                 indir1_blkno = -1;
 821         }
 822         if (indir2_block != NULL) {
 823                 free (indir2_block);
 824                 indir2_block = NULL;
 825                 indir2_size = 0;
 826                 indir2_blkno = -1;
 827         }
 828         return (0);
 829 }
 830
 831
 832 int ext2fs_read (char *buf, unsigned len) {
 833         int status;
 834
 835         if (ext2fs_root == NULL) {
 836                 return (0);
 837         }
 838
 839         if (ext2fs_file == NULL) {
 840                 return (0);
 841         }
 842
 843         status = ext2fs_read_file (ext2fs_file, 0, len, buf);
 844         return (status);
 845 }
 846
 847
 848 int ext2fs_mount (unsigned part_length) {
 849         struct ext2_data *data;
 850         int status;
 851
 852         data = malloc (sizeof (struct ext2_data));
 853         if (!data) {
 854                 return (0);
 855         }
 856         /* Read the superblock.  */
 857         status = ext2fs_devread (1 * 2, 0, sizeof (struct ext2_sblock),
 858                                  (char *) &data->sblock);
 859         if (status == 0) {
 860                 goto fail;
 861         }
 862         /* Make sure this is an ext2 filesystem.  */
 863         if (__le16_to_cpu (data->sblock.magic) != EXT2_MAGIC) {
 864                 goto fail;
 865         }
 866         data->diropen.data = data;
 867         data->diropen.ino = 2;
 868         data->diropen.inode_read = 1;
 869         data->inode = &data->diropen.inode;
 870
 871         status = ext2fs_read_inode (data, 2, data->inode);
 872         if (status == 0) {
 873                 goto fail;
 874         }
 875
 876         ext2fs_root = data;
 877
 878         return (1);
 879
 880 fail:
 881         printf ("Failed to mount ext2 filesystem...\n");
 882         free (data);
 883         ext2fs_root = NULL;
 884         return (0);
 885 }