lib/ext2fs/swapfs.c

   1 /*
   2  * swapfs.c --- swap ext2 filesystem data structures
   3  *
   4  * Copyright (C) 1995, 1996, 2002 Theodore Ts'o.
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Library
   8  * General Public License, version 2.
   9  * %End-Header%
  10  */
  11
  12 #include "config.h"
  13 #include <stdio.h>
  14 #if HAVE_UNISTD_H
  15 #include <unistd.h>
  16 #endif
  17 #include <string.h>
  18 #include <time.h>
  19
  20 #include "ext2_fs.h"
  21 #include "ext2fs.h"
  22 #include <ext2fs/ext2_ext_attr.h>
  23
  24 #ifdef WORDS_BIGENDIAN
  25 void ext2fs_swap_super(struct ext2_super_block * sb)
  26 {
  27         int i;
  28         sb->s_inodes_count = ext2fs_swab32(sb->s_inodes_count);
  29         sb->s_blocks_count = ext2fs_swab32(sb->s_blocks_count);
  30         sb->s_r_blocks_count = ext2fs_swab32(sb->s_r_blocks_count);
  31         sb->s_free_blocks_count = ext2fs_swab32(sb->s_free_blocks_count);
  32         sb->s_free_inodes_count = ext2fs_swab32(sb->s_free_inodes_count);
  33         sb->s_first_data_block = ext2fs_swab32(sb->s_first_data_block);
  34         sb->s_log_block_size = ext2fs_swab32(sb->s_log_block_size);
  35         sb->s_log_cluster_size = ext2fs_swab32(sb->s_log_cluster_size);
  36         sb->s_blocks_per_group = ext2fs_swab32(sb->s_blocks_per_group);
  37         sb->s_clusters_per_group = ext2fs_swab32(sb->s_clusters_per_group);
  38         sb->s_inodes_per_group = ext2fs_swab32(sb->s_inodes_per_group);
  39         sb->s_mtime = ext2fs_swab32(sb->s_mtime);
  40         sb->s_wtime = ext2fs_swab32(sb->s_wtime);
  41         sb->s_mnt_count = ext2fs_swab16(sb->s_mnt_count);
  42         sb->s_max_mnt_count = ext2fs_swab16(sb->s_max_mnt_count);
  43         sb->s_magic = ext2fs_swab16(sb->s_magic);
  44         sb->s_state = ext2fs_swab16(sb->s_state);
  45         sb->s_errors = ext2fs_swab16(sb->s_errors);
  46         sb->s_minor_rev_level = ext2fs_swab16(sb->s_minor_rev_level);
  47         sb->s_lastcheck = ext2fs_swab32(sb->s_lastcheck);
  48         sb->s_checkinterval = ext2fs_swab32(sb->s_checkinterval);
  49         sb->s_creator_os = ext2fs_swab32(sb->s_creator_os);
  50         sb->s_rev_level = ext2fs_swab32(sb->s_rev_level);
  51         sb->s_def_resuid = ext2fs_swab16(sb->s_def_resuid);
  52         sb->s_def_resgid = ext2fs_swab16(sb->s_def_resgid);
  53         sb->s_first_ino = ext2fs_swab32(sb->s_first_ino);
  54         sb->s_inode_size = ext2fs_swab16(sb->s_inode_size);
  55         sb->s_block_group_nr = ext2fs_swab16(sb->s_block_group_nr);
  56         sb->s_feature_compat = ext2fs_swab32(sb->s_feature_compat);
  57         sb->s_feature_incompat = ext2fs_swab32(sb->s_feature_incompat);
  58         sb->s_feature_ro_compat = ext2fs_swab32(sb->s_feature_ro_compat);
  59         sb->s_algorithm_usage_bitmap = ext2fs_swab32(sb->s_algorithm_usage_bitmap);
  60         sb->s_reserved_gdt_blocks = ext2fs_swab16(sb->s_reserved_gdt_blocks);
  61         sb->s_journal_inum = ext2fs_swab32(sb->s_journal_inum);
  62         sb->s_journal_dev = ext2fs_swab32(sb->s_journal_dev);
  63         sb->s_last_orphan = ext2fs_swab32(sb->s_last_orphan);
  64         sb->s_desc_size = ext2fs_swab16(sb->s_desc_size);
  65         sb->s_default_mount_opts = ext2fs_swab32(sb->s_default_mount_opts);
  66         sb->s_first_meta_bg = ext2fs_swab32(sb->s_first_meta_bg);
  67         sb->s_mkfs_time = ext2fs_swab32(sb->s_mkfs_time);
  68         sb->s_blocks_count_hi = ext2fs_swab32(sb->s_blocks_count_hi);
  69         sb->s_r_blocks_count_hi = ext2fs_swab32(sb->s_r_blocks_count_hi);
  70         sb->s_free_blocks_hi = ext2fs_swab32(sb->s_free_blocks_hi);
  71         sb->s_min_extra_isize = ext2fs_swab16(sb->s_min_extra_isize);
  72         sb->s_want_extra_isize = ext2fs_swab16(sb->s_want_extra_isize);
  73         sb->s_flags = ext2fs_swab32(sb->s_flags);
  74         sb->s_mmp_update_interval = ext2fs_swab16(sb->s_mmp_update_interval);
  75         sb->s_mmp_block = ext2fs_swab64(sb->s_mmp_block);
  76         sb->s_kbytes_written = ext2fs_swab64(sb->s_kbytes_written);
  77         sb->s_snapshot_inum = ext2fs_swab32(sb->s_snapshot_inum);
  78         sb->s_snapshot_id = ext2fs_swab32(sb->s_snapshot_id);
  79         sb->s_snapshot_r_blocks_count =
  80                 ext2fs_swab64(sb->s_snapshot_r_blocks_count);
  81         sb->s_snapshot_list = ext2fs_swab32(sb->s_snapshot_list);
  82         sb->s_usr_quota_inum = ext2fs_swab32(sb->s_usr_quota_inum);
  83         sb->s_grp_quota_inum = ext2fs_swab32(sb->s_grp_quota_inum);
  84         sb->s_overhead_blocks = ext2fs_swab32(sb->s_overhead_blocks);
  85         sb->s_checksum = ext2fs_swab32(sb->s_checksum);
  86
  87         for (i=0; i < 4; i++)
  88                 sb->s_hash_seed[i] = ext2fs_swab32(sb->s_hash_seed[i]);
  89
  90         /* if journal backup is for a valid extent-based journal... */
  91         if (ext2fs_extent_header_verify(sb->s_jnl_blocks,
  92                                         sizeof(sb->s_jnl_blocks)) == 0) {
  93                 /* ... swap only the journal i_size and i_size_high,
  94                  * and the extent data is not swapped on read */
  95                 i = 15;
  96         } else {
  97                 /* direct/indirect journal: swap it all */
  98                 i = 0;
  99         }
 100         for (; i < 17; i++)
 101                 sb->s_jnl_blocks[i] = ext2fs_swab32(sb->s_jnl_blocks[i]);
 102 }
 103
 104 void ext2fs_swap_group_desc2(ext2_filsys fs, struct ext2_group_desc *gdp)
 105 {
 106         /* Do the 32-bit parts first */
 107         gdp->bg_block_bitmap = ext2fs_swab32(gdp->bg_block_bitmap);
 108         gdp->bg_inode_bitmap = ext2fs_swab32(gdp->bg_inode_bitmap);
 109         gdp->bg_inode_table = ext2fs_swab32(gdp->bg_inode_table);
 110         gdp->bg_free_blocks_count = ext2fs_swab16(gdp->bg_free_blocks_count);
 111         gdp->bg_free_inodes_count = ext2fs_swab16(gdp->bg_free_inodes_count);
 112         gdp->bg_used_dirs_count = ext2fs_swab16(gdp->bg_used_dirs_count);
 113         gdp->bg_flags = ext2fs_swab16(gdp->bg_flags);
 114         gdp->bg_exclude_bitmap_lo = ext2fs_swab32(gdp->bg_exclude_bitmap_lo);
 115         gdp->bg_block_bitmap_csum_lo =
 116                 ext2fs_swab16(gdp->bg_block_bitmap_csum_lo);
 117         gdp->bg_inode_bitmap_csum_lo =
 118                 ext2fs_swab16(gdp->bg_inode_bitmap_csum_lo);
 119         gdp->bg_itable_unused = ext2fs_swab16(gdp->bg_itable_unused);
 120         gdp->bg_checksum = ext2fs_swab16(gdp->bg_checksum);
 121         /* If we're 32-bit, we're done */
 122         if (fs && (!fs->super->s_desc_size ||
 123                    (fs->super->s_desc_size < EXT2_MIN_DESC_SIZE_64BIT)))
 124                 return;
 125
 126         /* Swap the 64-bit parts */
 127         struct ext4_group_desc *gdp4 = (struct ext4_group_desc *) gdp;
 128         gdp4->bg_block_bitmap_hi = ext2fs_swab32(gdp4->bg_block_bitmap_hi);
 129         gdp4->bg_inode_bitmap_hi = ext2fs_swab32(gdp4->bg_inode_bitmap_hi);
 130         gdp4->bg_inode_table_hi = ext2fs_swab32(gdp4->bg_inode_table_hi);
 131         gdp4->bg_free_blocks_count_hi =
 132                 ext2fs_swab16(gdp4->bg_free_blocks_count_hi);
 133         gdp4->bg_free_inodes_count_hi =
 134                 ext2fs_swab16(gdp4->bg_free_inodes_count_hi);
 135         gdp4->bg_used_dirs_count_hi =
 136                 ext2fs_swab16(gdp4->bg_used_dirs_count_hi);
 137         gdp4->bg_itable_unused_hi = ext2fs_swab16(gdp4->bg_itable_unused_hi);
 138         gdp4->bg_exclude_bitmap_hi = ext2fs_swab16(gdp4->bg_exclude_bitmap_hi);
 139         gdp4->bg_block_bitmap_csum_hi =
 140                 ext2fs_swab16(gdp4->bg_block_bitmap_csum_hi);
 141         gdp4->bg_inode_bitmap_csum_hi =
 142                 ext2fs_swab16(gdp4->bg_inode_bitmap_csum_hi);
 143 }
 144
 145 void ext2fs_swap_group_desc(struct ext2_group_desc *gdp)
 146 {
 147         ext2fs_swap_group_desc2(0, gdp);
 148 }
 149
 150
 151 void ext2fs_swap_ext_attr_header(struct ext2_ext_attr_header *to_header,
 152                                  struct ext2_ext_attr_header *from_header)
 153 {
 154         int n;
 155
 156         to_header->h_magic    = ext2fs_swab32(from_header->h_magic);
 157         to_header->h_blocks   = ext2fs_swab32(from_header->h_blocks);
 158         to_header->h_refcount = ext2fs_swab32(from_header->h_refcount);
 159         to_header->h_hash     = ext2fs_swab32(from_header->h_hash);
 160         for (n = 0; n < 4; n++)
 161                 to_header->h_reserved[n] =
 162                         ext2fs_swab32(from_header->h_reserved[n]);
 163 }
 164
 165 void ext2fs_swap_ext_attr_entry(struct ext2_ext_attr_entry *to_entry,
 166                                 struct ext2_ext_attr_entry *from_entry)
 167 {
 168         to_entry->e_value_offs  = ext2fs_swab16(from_entry->e_value_offs);
 169         to_entry->e_value_block = ext2fs_swab32(from_entry->e_value_block);
 170         to_entry->e_value_size  = ext2fs_swab32(from_entry->e_value_size);
 171         to_entry->e_hash        = ext2fs_swab32(from_entry->e_hash);
 172 }
 173
 174 void ext2fs_swap_ext_attr(char *to, char *from, int bufsize, int has_header)
 175 {
 176         struct ext2_ext_attr_header *from_header =
 177                 (struct ext2_ext_attr_header *)from;
 178         struct ext2_ext_attr_header *to_header =
 179                 (struct ext2_ext_attr_header *)to;
 180         struct ext2_ext_attr_entry *from_entry, *to_entry;
 181         char *from_end = (char *)from_header + bufsize;
 182
 183         if (to_header != from_header)
 184                 memcpy(to_header, from_header, bufsize);
 185
 186         if (has_header) {
 187                 ext2fs_swap_ext_attr_header(to_header, from_header);
 188
 189                 from_entry = (struct ext2_ext_attr_entry *)(from_header+1);
 190                 to_entry   = (struct ext2_ext_attr_entry *)(to_header+1);
 191         } else {
 192                 from_entry = (struct ext2_ext_attr_entry *)from_header;
 193                 to_entry   = (struct ext2_ext_attr_entry *)to_header;
 194         }
 195
 196         while ((char *)from_entry < from_end && *(__u32 *)from_entry) {
 197                 ext2fs_swap_ext_attr_entry(to_entry, from_entry);
 198                 from_entry = EXT2_EXT_ATTR_NEXT(from_entry);
 199                 to_entry   = EXT2_EXT_ATTR_NEXT(to_entry);
 200         }
 201 }
 202
 203 void ext2fs_swap_inode_full(ext2_filsys fs, struct ext2_inode_large *t,
 204                             struct ext2_inode_large *f, int hostorder,
 205                             int bufsize)
 206 {
 207         unsigned i, has_data_blocks, extra_isize, attr_magic;
 208         int has_extents = 0;
 209         int islnk = 0;
 210         __u32 *eaf, *eat;
 211
 212         if (hostorder && LINUX_S_ISLNK(f->i_mode))
 213                 islnk = 1;
 214         t->i_mode = ext2fs_swab16(f->i_mode);
 215         if (!hostorder && LINUX_S_ISLNK(t->i_mode))
 216                 islnk = 1;
 217         t->i_uid = ext2fs_swab16(f->i_uid);
 218         t->i_size = ext2fs_swab32(f->i_size);
 219         t->i_atime = ext2fs_swab32(f->i_atime);
 220         t->i_ctime = ext2fs_swab32(f->i_ctime);
 221         t->i_mtime = ext2fs_swab32(f->i_mtime);
 222         t->i_dtime = ext2fs_swab32(f->i_dtime);
 223         t->i_gid = ext2fs_swab16(f->i_gid);
 224         t->i_links_count = ext2fs_swab16(f->i_links_count);
 225         t->i_file_acl = ext2fs_swab32(f->i_file_acl);
 226         if (hostorder)
 227                 has_data_blocks = ext2fs_inode_data_blocks(fs,
 228                                            (struct ext2_inode *) f);
 229         t->i_blocks = ext2fs_swab32(f->i_blocks);
 230         if (!hostorder)
 231                 has_data_blocks = ext2fs_inode_data_blocks(fs,
 232                                            (struct ext2_inode *) t);
 233         if (hostorder && (f->i_flags & EXT4_EXTENTS_FL))
 234                 has_extents = 1;
 235         t->i_flags = ext2fs_swab32(f->i_flags);
 236         if (!hostorder && (t->i_flags & EXT4_EXTENTS_FL))
 237                 has_extents = 1;
 238         t->i_dir_acl = ext2fs_swab32(f->i_dir_acl);
 239         /* extent data are swapped on access, not here */
 240         if (!has_extents && (!islnk || has_data_blocks)) {
 241                 for (i = 0; i < EXT2_N_BLOCKS; i++)
 242                         t->i_block[i] = ext2fs_swab32(f->i_block[i]);
 243         } else if (t != f) {
 244                 for (i = 0; i < EXT2_N_BLOCKS; i++)
 245                         t->i_block[i] = f->i_block[i];
 246         }
 247         t->i_generation = ext2fs_swab32(f->i_generation);
 248         t->i_faddr = ext2fs_swab32(f->i_faddr);
 249
 250         switch (fs->super->s_creator_os) {
 251         case EXT2_OS_LINUX:
 252                 t->osd1.linux1.l_i_version =
 253                         ext2fs_swab32(f->osd1.linux1.l_i_version);
 254                 t->osd2.linux2.l_i_blocks_hi =
 255                         ext2fs_swab16(f->osd2.linux2.l_i_blocks_hi);
 256                 t->osd2.linux2.l_i_file_acl_high =
 257                         ext2fs_swab16(f->osd2.linux2.l_i_file_acl_high);
 258                 t->osd2.linux2.l_i_uid_high =
 259                   ext2fs_swab16 (f->osd2.linux2.l_i_uid_high);
 260                 t->osd2.linux2.l_i_gid_high =
 261                   ext2fs_swab16 (f->osd2.linux2.l_i_gid_high);
 262                 t->osd2.linux2.l_i_checksum_lo =
 263                         ext2fs_swab16(f->osd2.linux2.l_i_checksum_lo);
 264                 break;
 265         case EXT2_OS_HURD:
 266                 t->osd1.hurd1.h_i_translator =
 267                   ext2fs_swab32 (f->osd1.hurd1.h_i_translator);
 268                 t->osd2.hurd2.h_i_frag = f->osd2.hurd2.h_i_frag;
 269                 t->osd2.hurd2.h_i_fsize = f->osd2.hurd2.h_i_fsize;
 270                 t->osd2.hurd2.h_i_mode_high =
 271                   ext2fs_swab16 (f->osd2.hurd2.h_i_mode_high);
 272                 t->osd2.hurd2.h_i_uid_high =
 273                   ext2fs_swab16 (f->osd2.hurd2.h_i_uid_high);
 274                 t->osd2.hurd2.h_i_gid_high =
 275                   ext2fs_swab16 (f->osd2.hurd2.h_i_gid_high);
 276                 t->osd2.hurd2.h_i_author =
 277                   ext2fs_swab32 (f->osd2.hurd2.h_i_author);
 278                 break;
 279         default:
 280                 break;
 281         }
 282
 283         if (bufsize < (int) (sizeof(struct ext2_inode) + sizeof(__u16)))
 284                 return; /* no i_extra_isize field */
 285
 286         if (hostorder)
 287                 extra_isize = f->i_extra_isize;
 288         t->i_extra_isize = ext2fs_swab16(f->i_extra_isize);
 289         if (!hostorder)
 290                 extra_isize = t->i_extra_isize;
 291         if (extra_isize > EXT2_INODE_SIZE(fs->super) -
 292                                 sizeof(struct ext2_inode)) {
 293                 /* this is error case: i_extra_size is too large */
 294                 return;
 295         }
 296
 297         if (extra_isize >= 4)
 298                 t->i_checksum_hi = ext2fs_swab16(f->i_checksum_hi);
 299         if (extra_isize >= 8)
 300                 t->i_ctime_extra = ext2fs_swab32(f->i_ctime_extra);
 301         if (extra_isize >= 12)
 302                 t->i_mtime_extra = ext2fs_swab32(f->i_mtime_extra);
 303         if (extra_isize >= 16)
 304                 t->i_atime_extra = ext2fs_swab32(f->i_atime_extra);
 305         if (extra_isize >= 20)
 306                 t->i_crtime = ext2fs_swab32(f->i_crtime);
 307         if (extra_isize >= 24)
 308                 t->i_crtime_extra = ext2fs_swab32(f->i_crtime_extra);
 309         if (extra_isize >= 28)
 310                 t->i_version_hi = ext2fs_swab32(f->i_version_hi);
 311
 312         i = sizeof(struct ext2_inode) + extra_isize + sizeof(__u32);
 313         if (bufsize < (int) i)
 314                 return; /* no space for EA magic */
 315
 316         eaf = (__u32 *) (((char *) f) + sizeof(struct ext2_inode) +
 317                                         extra_isize);
 318
 319         attr_magic = *eaf;
 320         if (!hostorder)
 321                 attr_magic = ext2fs_swab32(attr_magic);
 322
 323         if (attr_magic != EXT2_EXT_ATTR_MAGIC)
 324                 return; /* it seems no magic here */
 325
 326         eat = (__u32 *) (((char *) t) + sizeof(struct ext2_inode) +
 327                                         extra_isize);
 328         *eat = ext2fs_swab32(*eaf);
 329
 330         /* convert EA(s) */
 331         ext2fs_swap_ext_attr((char *) (eat + 1), (char *) (eaf + 1),
 332                              bufsize - sizeof(struct ext2_inode) -
 333                              extra_isize - sizeof(__u32), 0);
 334
 335 }
 336
 337 void ext2fs_swap_inode(ext2_filsys fs, struct ext2_inode *t,
 338                        struct ext2_inode *f, int hostorder)
 339 {
 340         ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) t,
 341                                 (struct ext2_inode_large *) f, hostorder,
 342                                 sizeof(struct ext2_inode));
 343 }
 344
 345 void ext2fs_swap_mmp(struct mmp_struct *mmp)
 346 {
 347         mmp->mmp_magic = ext2fs_swab32(mmp->mmp_magic);
 348         mmp->mmp_seq = ext2fs_swab32(mmp->mmp_seq);
 349         mmp->mmp_time = ext2fs_swab64(mmp->mmp_time);
 350         mmp->mmp_check_interval = ext2fs_swab16(mmp->mmp_check_interval);
 351 }
 352
 353 errcode_t ext2fs_dirent_swab_in(ext2_filsys fs, char *buf, int flags)
 354 {
 355         errcode_t       retval;
 356         char            *p, *end;
 357         struct ext2_dir_entry *dirent;
 358         unsigned int    name_len, rec_len;
 359
 360         p = (char *) buf;
 361         end = (char *) buf + fs->blocksize;
 362         while (p < end-8) {
 363                 dirent = (struct ext2_dir_entry *) p;
 364                 dirent->inode = ext2fs_swab32(dirent->inode);
 365                 dirent->rec_len = ext2fs_swab16(dirent->rec_len);
 366                 dirent->name_len = ext2fs_swab16(dirent->name_len);
 367                 name_len = dirent->name_len;
 368                 if (flags & EXT2_DIRBLOCK_V2_STRUCT)
 369                         dirent->name_len = ext2fs_swab16(dirent->name_len);
 370                 retval = ext2fs_get_rec_len(fs, dirent, &rec_len);
 371                 if (retval)
 372                         return retval;
 373                 if ((rec_len < 8) || (rec_len % 4)) {
 374                         rec_len = 8;
 375                         retval = EXT2_ET_DIR_CORRUPTED;
 376                 } else if (((name_len & 0xFF) + 8) > rec_len)
 377                         retval = EXT2_ET_DIR_CORRUPTED;
 378                 p += rec_len;
 379         }
 380
 381         return 0;
 382 }
 383
 384 errcode_t ext2fs_dirent_swab_out(ext2_filsys fs, char *buf, int flags)
 385 {
 386         errcode_t       retval;
 387         char            *p, *end;
 388         unsigned int    rec_len;
 389         struct ext2_dir_entry *dirent;
 390
 391         p = buf;
 392         end = buf + fs->blocksize;
 393         while (p < end) {
 394                 dirent = (struct ext2_dir_entry *) p;
 395                 retval = ext2fs_get_rec_len(fs, dirent, &rec_len);
 396                 if (retval)
 397                         return retval;
 398                 if ((rec_len < 8) ||
 399                     (rec_len % 4)) {
 400                         ext2fs_free_mem(&buf);
 401                         return EXT2_ET_DIR_CORRUPTED;
 402                 }
 403                 p += rec_len;
 404                 dirent->inode = ext2fs_swab32(dirent->inode);
 405                 dirent->rec_len = ext2fs_swab16(dirent->rec_len);
 406                 dirent->name_len = ext2fs_swab16(dirent->name_len);
 407
 408                 if (flags & EXT2_DIRBLOCK_V2_STRUCT)
 409                         dirent->name_len = ext2fs_swab16(dirent->name_len);
 410         }
 411
 412         return 0;
 413 }
 414
 415 #endif