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         struct ext4_group_desc *gdp4 = (struct ext4_group_desc *)gdp;
 107
 108         /* Do the 32-bit parts first */
 109         gdp->bg_block_bitmap = ext2fs_swab32(gdp->bg_block_bitmap);
 110         gdp->bg_inode_bitmap = ext2fs_swab32(gdp->bg_inode_bitmap);
 111         gdp->bg_inode_table = ext2fs_swab32(gdp->bg_inode_table);
 112         gdp->bg_free_blocks_count = ext2fs_swab16(gdp->bg_free_blocks_count);
 113         gdp->bg_free_inodes_count = ext2fs_swab16(gdp->bg_free_inodes_count);
 114         gdp->bg_used_dirs_count = ext2fs_swab16(gdp->bg_used_dirs_count);
 115         gdp->bg_flags = ext2fs_swab16(gdp->bg_flags);
 116         gdp->bg_exclude_bitmap_lo = ext2fs_swab32(gdp->bg_exclude_bitmap_lo);
 117         gdp->bg_block_bitmap_csum_lo =
 118                 ext2fs_swab16(gdp->bg_block_bitmap_csum_lo);
 119         gdp->bg_inode_bitmap_csum_lo =
 120                 ext2fs_swab16(gdp->bg_inode_bitmap_csum_lo);
 121         gdp->bg_itable_unused = ext2fs_swab16(gdp->bg_itable_unused);
 122         gdp->bg_checksum = ext2fs_swab16(gdp->bg_checksum);
 123         /* If we're 32-bit, we're done */
 124         if (fs == NULL || EXT2_DESC_SIZE(fs->super) < EXT2_MIN_DESC_SIZE_64BIT)
 125                 return;
 126
 127         /* Swap the 64-bit parts */
 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         to_header->h_checksum = ext2fs_swab32(from_header->h_checksum);
 161         for (n = 0; n < 3; n++)
 162                 to_header->h_reserved[n] =
 163                         ext2fs_swab32(from_header->h_reserved[n]);
 164 }
 165
 166 void ext2fs_swap_ext_attr_entry(struct ext2_ext_attr_entry *to_entry,
 167                                 struct ext2_ext_attr_entry *from_entry)
 168 {
 169         to_entry->e_value_offs  = ext2fs_swab16(from_entry->e_value_offs);
 170         to_entry->e_value_block = ext2fs_swab32(from_entry->e_value_block);
 171         to_entry->e_value_size  = ext2fs_swab32(from_entry->e_value_size);
 172         to_entry->e_hash        = ext2fs_swab32(from_entry->e_hash);
 173 }
 174
 175 void ext2fs_swap_ext_attr(char *to, char *from, int bufsize, int has_header)
 176 {
 177         struct ext2_ext_attr_header *from_header =
 178                 (struct ext2_ext_attr_header *)from;
 179         struct ext2_ext_attr_header *to_header =
 180                 (struct ext2_ext_attr_header *)to;
 181         struct ext2_ext_attr_entry *from_entry, *to_entry;
 182         char *from_end = (char *)from_header + bufsize;
 183
 184         if (to_header != from_header)
 185                 memcpy(to_header, from_header, bufsize);
 186
 187         if (has_header) {
 188                 ext2fs_swap_ext_attr_header(to_header, from_header);
 189
 190                 from_entry = (struct ext2_ext_attr_entry *)(from_header+1);
 191                 to_entry   = (struct ext2_ext_attr_entry *)(to_header+1);
 192         } else {
 193                 from_entry = (struct ext2_ext_attr_entry *)from_header;
 194                 to_entry   = (struct ext2_ext_attr_entry *)to_header;
 195         }
 196
 197         while ((char *)from_entry < from_end && *(__u32 *)from_entry) {
 198                 ext2fs_swap_ext_attr_entry(to_entry, from_entry);
 199                 from_entry = EXT2_EXT_ATTR_NEXT(from_entry);
 200                 to_entry   = EXT2_EXT_ATTR_NEXT(to_entry);
 201         }
 202 }
 203
 204 void ext2fs_swap_inode_full(ext2_filsys fs, struct ext2_inode_large *t,
 205                             struct ext2_inode_large *f, int hostorder,
 206                             int bufsize)
 207 {
 208         unsigned i, has_data_blocks, extra_isize, attr_magic;
 209         int has_extents = 0;
 210         int islnk = 0;
 211         __u32 *eaf, *eat;
 212
 213         if (hostorder && LINUX_S_ISLNK(f->i_mode))
 214                 islnk = 1;
 215         t->i_mode = ext2fs_swab16(f->i_mode);
 216         if (!hostorder && LINUX_S_ISLNK(t->i_mode))
 217                 islnk = 1;
 218         t->i_uid = ext2fs_swab16(f->i_uid);
 219         t->i_size = ext2fs_swab32(f->i_size);
 220         t->i_atime = ext2fs_swab32(f->i_atime);
 221         t->i_ctime = ext2fs_swab32(f->i_ctime);
 222         t->i_mtime = ext2fs_swab32(f->i_mtime);
 223         t->i_dtime = ext2fs_swab32(f->i_dtime);
 224         t->i_gid = ext2fs_swab16(f->i_gid);
 225         t->i_links_count = ext2fs_swab16(f->i_links_count);
 226         t->i_file_acl = ext2fs_swab32(f->i_file_acl);
 227         if (hostorder)
 228                 has_data_blocks = ext2fs_inode_data_blocks(fs,
 229                                            (struct ext2_inode *) f);
 230         t->i_blocks = ext2fs_swab32(f->i_blocks);
 231         if (!hostorder)
 232                 has_data_blocks = ext2fs_inode_data_blocks(fs,
 233                                            (struct ext2_inode *) t);
 234         if (hostorder && (f->i_flags & EXT4_EXTENTS_FL))
 235                 has_extents = 1;
 236         t->i_flags = ext2fs_swab32(f->i_flags);
 237         if (!hostorder && (t->i_flags & EXT4_EXTENTS_FL))
 238                 has_extents = 1;
 239         t->i_dir_acl = ext2fs_swab32(f->i_dir_acl);
 240         /* extent data are swapped on access, not here */
 241         if (!has_extents && (!islnk || has_data_blocks)) {
 242                 for (i = 0; i < EXT2_N_BLOCKS; i++)
 243                         t->i_block[i] = ext2fs_swab32(f->i_block[i]);
 244         } else if (t != f) {
 245                 for (i = 0; i < EXT2_N_BLOCKS; i++)
 246                         t->i_block[i] = f->i_block[i];
 247         }
 248         t->i_generation = ext2fs_swab32(f->i_generation);
 249         t->i_faddr = ext2fs_swab32(f->i_faddr);
 250
 251         switch (fs->super->s_creator_os) {
 252         case EXT2_OS_LINUX:
 253                 t->osd1.linux1.l_i_version =
 254                         ext2fs_swab32(f->osd1.linux1.l_i_version);
 255                 t->osd2.linux2.l_i_blocks_hi =
 256                         ext2fs_swab16(f->osd2.linux2.l_i_blocks_hi);
 257                 t->osd2.linux2.l_i_file_acl_high =
 258                         ext2fs_swab16(f->osd2.linux2.l_i_file_acl_high);
 259                 t->osd2.linux2.l_i_uid_high =
 260                   ext2fs_swab16 (f->osd2.linux2.l_i_uid_high);
 261                 t->osd2.linux2.l_i_gid_high =
 262                   ext2fs_swab16 (f->osd2.linux2.l_i_gid_high);
 263                 t->osd2.linux2.l_i_checksum_lo =
 264                         ext2fs_swab16(f->osd2.linux2.l_i_checksum_lo);
 265                 break;
 266         case EXT2_OS_HURD:
 267                 t->osd1.hurd1.h_i_translator =
 268                   ext2fs_swab32 (f->osd1.hurd1.h_i_translator);
 269                 t->osd2.hurd2.h_i_frag = f->osd2.hurd2.h_i_frag;
 270                 t->osd2.hurd2.h_i_fsize = f->osd2.hurd2.h_i_fsize;
 271                 t->osd2.hurd2.h_i_mode_high =
 272                   ext2fs_swab16 (f->osd2.hurd2.h_i_mode_high);
 273                 t->osd2.hurd2.h_i_uid_high =
 274                   ext2fs_swab16 (f->osd2.hurd2.h_i_uid_high);
 275                 t->osd2.hurd2.h_i_gid_high =
 276                   ext2fs_swab16 (f->osd2.hurd2.h_i_gid_high);
 277                 t->osd2.hurd2.h_i_author =
 278                   ext2fs_swab32 (f->osd2.hurd2.h_i_author);
 279                 break;
 280         default:
 281                 break;
 282         }
 283
 284         if (bufsize < (int) (sizeof(struct ext2_inode) + sizeof(__u16)))
 285                 return; /* no i_extra_isize field */
 286
 287         if (hostorder)
 288                 extra_isize = f->i_extra_isize;
 289         t->i_extra_isize = ext2fs_swab16(f->i_extra_isize);
 290         if (!hostorder)
 291                 extra_isize = t->i_extra_isize;
 292         if (extra_isize > EXT2_INODE_SIZE(fs->super) -
 293                                 sizeof(struct ext2_inode)) {
 294                 /* this is error case: i_extra_size is too large */
 295                 return;
 296         }
 297
 298         if (extra_isize >= 4)
 299                 t->i_checksum_hi = ext2fs_swab16(f->i_checksum_hi);
 300         if (extra_isize >= 8)
 301                 t->i_ctime_extra = ext2fs_swab32(f->i_ctime_extra);
 302         if (extra_isize >= 12)
 303                 t->i_mtime_extra = ext2fs_swab32(f->i_mtime_extra);
 304         if (extra_isize >= 16)
 305                 t->i_atime_extra = ext2fs_swab32(f->i_atime_extra);
 306         if (extra_isize >= 20)
 307                 t->i_crtime = ext2fs_swab32(f->i_crtime);
 308         if (extra_isize >= 24)
 309                 t->i_crtime_extra = ext2fs_swab32(f->i_crtime_extra);
 310         if (extra_isize >= 28)
 311                 t->i_version_hi = ext2fs_swab32(f->i_version_hi);
 312
 313         i = sizeof(struct ext2_inode) + extra_isize + sizeof(__u32);
 314         if (bufsize < (int) i)
 315                 return; /* no space for EA magic */
 316
 317         eaf = (__u32 *) (((char *) f) + sizeof(struct ext2_inode) +
 318                                         extra_isize);
 319
 320         attr_magic = *eaf;
 321         if (!hostorder)
 322                 attr_magic = ext2fs_swab32(attr_magic);
 323
 324         if (attr_magic != EXT2_EXT_ATTR_MAGIC)
 325                 return; /* it seems no magic here */
 326
 327         eat = (__u32 *) (((char *) t) + sizeof(struct ext2_inode) +
 328                                         extra_isize);
 329         *eat = ext2fs_swab32(*eaf);
 330
 331         /* convert EA(s) */
 332         ext2fs_swap_ext_attr((char *) (eat + 1), (char *) (eaf + 1),
 333                              bufsize - sizeof(struct ext2_inode) -
 334                              extra_isize - sizeof(__u32), 0);
 335
 336 }
 337
 338 void ext2fs_swap_inode(ext2_filsys fs, struct ext2_inode *t,
 339                        struct ext2_inode *f, int hostorder)
 340 {
 341         ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) t,
 342                                 (struct ext2_inode_large *) f, hostorder,
 343                                 sizeof(struct ext2_inode));
 344 }
 345
 346 void ext2fs_swap_mmp(struct mmp_struct *mmp)
 347 {
 348         mmp->mmp_magic = ext2fs_swab32(mmp->mmp_magic);
 349         mmp->mmp_seq = ext2fs_swab32(mmp->mmp_seq);
 350         mmp->mmp_time = ext2fs_swab64(mmp->mmp_time);
 351         mmp->mmp_check_interval = ext2fs_swab16(mmp->mmp_check_interval);
 352         mmp->mmp_checksum = ext2fs_swab32(mmp->mmp_checksum);
 353 }
 354
 355 errcode_t ext2fs_dirent_swab_in(ext2_filsys fs, char *buf, int flags)
 356 {
 357         errcode_t       retval;
 358         char            *p, *end;
 359         struct ext2_dir_entry *dirent;
 360         unsigned int    name_len, rec_len;
 361
 362         p = (char *) buf;
 363         end = (char *) buf + fs->blocksize;
 364         while (p < end-8) {
 365                 dirent = (struct ext2_dir_entry *) p;
 366                 dirent->inode = ext2fs_swab32(dirent->inode);
 367                 dirent->rec_len = ext2fs_swab16(dirent->rec_len);
 368                 dirent->name_len = ext2fs_swab16(dirent->name_len);
 369                 name_len = dirent->name_len;
 370                 if (flags & EXT2_DIRBLOCK_V2_STRUCT)
 371                         dirent->name_len = ext2fs_swab16(dirent->name_len);
 372                 retval = ext2fs_get_rec_len(fs, dirent, &rec_len);
 373                 if (retval)
 374                         return retval;
 375                 if ((rec_len < 8) || (rec_len % 4)) {
 376                         rec_len = 8;
 377                         retval = EXT2_ET_DIR_CORRUPTED;
 378                 } else if (((name_len & 0xFF) + 8) > rec_len)
 379                         retval = EXT2_ET_DIR_CORRUPTED;
 380                 p += rec_len;
 381         }
 382
 383         return 0;
 384 }
 385
 386 errcode_t ext2fs_dirent_swab_out(ext2_filsys fs, char *buf, int flags)
 387 {
 388         errcode_t       retval;
 389         char            *p, *end;
 390         unsigned int    rec_len;
 391         struct ext2_dir_entry *dirent;
 392
 393         p = buf;
 394         end = buf + fs->blocksize;
 395         while (p < end) {
 396                 dirent = (struct ext2_dir_entry *) p;
 397                 retval = ext2fs_get_rec_len(fs, dirent, &rec_len);
 398                 if (retval)
 399                         return retval;
 400                 if ((rec_len < 8) ||
 401                     (rec_len % 4)) {
 402                         ext2fs_free_mem(&buf);
 403                         return EXT2_ET_DIR_CORRUPTED;
 404                 }
 405                 p += rec_len;
 406                 dirent->inode = ext2fs_swab32(dirent->inode);
 407                 dirent->rec_len = ext2fs_swab16(dirent->rec_len);
 408                 dirent->name_len = ext2fs_swab16(dirent->name_len);
 409
 410                 if (flags & EXT2_DIRBLOCK_V2_STRUCT)
 411                         dirent->name_len = ext2fs_swab16(dirent->name_len);
 412         }
 413
 414         return 0;
 415 }
 416
 417 #endif