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         sb->s_backup_bgs[0] = ext2fs_swab32(sb->s_backup_bgs[0]);
 103         sb->s_backup_bgs[1] = ext2fs_swab32(sb->s_backup_bgs[1]);
 104 }
 105
 106 void ext2fs_swap_group_desc2(ext2_filsys fs, struct ext2_group_desc *gdp)
 107 {
 108         struct ext4_group_desc *gdp4 = (struct ext4_group_desc *)gdp;
 109
 110         /* Do the 32-bit parts first */
 111         gdp->bg_block_bitmap = ext2fs_swab32(gdp->bg_block_bitmap);
 112         gdp->bg_inode_bitmap = ext2fs_swab32(gdp->bg_inode_bitmap);
 113         gdp->bg_inode_table = ext2fs_swab32(gdp->bg_inode_table);
 114         gdp->bg_free_blocks_count = ext2fs_swab16(gdp->bg_free_blocks_count);
 115         gdp->bg_free_inodes_count = ext2fs_swab16(gdp->bg_free_inodes_count);
 116         gdp->bg_used_dirs_count = ext2fs_swab16(gdp->bg_used_dirs_count);
 117         gdp->bg_flags = ext2fs_swab16(gdp->bg_flags);
 118         gdp->bg_exclude_bitmap_lo = ext2fs_swab32(gdp->bg_exclude_bitmap_lo);
 119         gdp->bg_block_bitmap_csum_lo =
 120                 ext2fs_swab16(gdp->bg_block_bitmap_csum_lo);
 121         gdp->bg_inode_bitmap_csum_lo =
 122                 ext2fs_swab16(gdp->bg_inode_bitmap_csum_lo);
 123         gdp->bg_itable_unused = ext2fs_swab16(gdp->bg_itable_unused);
 124         gdp->bg_checksum = ext2fs_swab16(gdp->bg_checksum);
 125         /* If we're 32-bit, we're done */
 126         if (fs == NULL || EXT2_DESC_SIZE(fs->super) < EXT2_MIN_DESC_SIZE_64BIT)
 127                 return;
 128
 129         /* Swap the 64-bit parts */
 130         gdp4->bg_block_bitmap_hi = ext2fs_swab32(gdp4->bg_block_bitmap_hi);
 131         gdp4->bg_inode_bitmap_hi = ext2fs_swab32(gdp4->bg_inode_bitmap_hi);
 132         gdp4->bg_inode_table_hi = ext2fs_swab32(gdp4->bg_inode_table_hi);
 133         gdp4->bg_free_blocks_count_hi =
 134                 ext2fs_swab16(gdp4->bg_free_blocks_count_hi);
 135         gdp4->bg_free_inodes_count_hi =
 136                 ext2fs_swab16(gdp4->bg_free_inodes_count_hi);
 137         gdp4->bg_used_dirs_count_hi =
 138                 ext2fs_swab16(gdp4->bg_used_dirs_count_hi);
 139         gdp4->bg_itable_unused_hi = ext2fs_swab16(gdp4->bg_itable_unused_hi);
 140         gdp4->bg_exclude_bitmap_hi = ext2fs_swab16(gdp4->bg_exclude_bitmap_hi);
 141         gdp4->bg_block_bitmap_csum_hi =
 142                 ext2fs_swab16(gdp4->bg_block_bitmap_csum_hi);
 143         gdp4->bg_inode_bitmap_csum_hi =
 144                 ext2fs_swab16(gdp4->bg_inode_bitmap_csum_hi);
 145 }
 146
 147 void ext2fs_swap_group_desc(struct ext2_group_desc *gdp)
 148 {
 149         ext2fs_swap_group_desc2(0, gdp);
 150 }
 151
 152
 153 void ext2fs_swap_ext_attr_header(struct ext2_ext_attr_header *to_header,
 154                                  struct ext2_ext_attr_header *from_header)
 155 {
 156         int n;
 157
 158         to_header->h_magic    = ext2fs_swab32(from_header->h_magic);
 159         to_header->h_blocks   = ext2fs_swab32(from_header->h_blocks);
 160         to_header->h_refcount = ext2fs_swab32(from_header->h_refcount);
 161         to_header->h_hash     = ext2fs_swab32(from_header->h_hash);
 162         for (n = 0; n < 4; n++)
 163                 to_header->h_reserved[n] =
 164                         ext2fs_swab32(from_header->h_reserved[n]);
 165 }
 166
 167 void ext2fs_swap_ext_attr_entry(struct ext2_ext_attr_entry *to_entry,
 168                                 struct ext2_ext_attr_entry *from_entry)
 169 {
 170         to_entry->e_value_offs  = ext2fs_swab16(from_entry->e_value_offs);
 171         to_entry->e_value_block = ext2fs_swab32(from_entry->e_value_block);
 172         to_entry->e_value_size  = ext2fs_swab32(from_entry->e_value_size);
 173         to_entry->e_hash        = ext2fs_swab32(from_entry->e_hash);
 174 }
 175
 176 void ext2fs_swap_ext_attr(char *to, char *from, int bufsize, int has_header)
 177 {
 178         struct ext2_ext_attr_header *from_header =
 179                 (struct ext2_ext_attr_header *)from;
 180         struct ext2_ext_attr_header *to_header =
 181                 (struct ext2_ext_attr_header *)to;
 182         struct ext2_ext_attr_entry *from_entry, *to_entry;
 183         char *from_end = (char *)from_header + bufsize;
 184
 185         if (to_header != from_header)
 186                 memcpy(to_header, from_header, bufsize);
 187
 188         if (has_header) {
 189                 ext2fs_swap_ext_attr_header(to_header, from_header);
 190
 191                 from_entry = (struct ext2_ext_attr_entry *)(from_header+1);
 192                 to_entry   = (struct ext2_ext_attr_entry *)(to_header+1);
 193         } else {
 194                 from_entry = (struct ext2_ext_attr_entry *)from_header;
 195                 to_entry   = (struct ext2_ext_attr_entry *)to_header;
 196         }
 197
 198         while ((char *)from_entry < from_end && *(__u32 *)from_entry) {
 199                 ext2fs_swap_ext_attr_entry(to_entry, from_entry);
 200                 from_entry = EXT2_EXT_ATTR_NEXT(from_entry);
 201                 to_entry   = EXT2_EXT_ATTR_NEXT(to_entry);
 202         }
 203 }
 204
 205 void ext2fs_swap_inode_full(ext2_filsys fs, struct ext2_inode_large *t,
 206                             struct ext2_inode_large *f, int hostorder,
 207                             int bufsize)
 208 {
 209         unsigned i, has_data_blocks, extra_isize, attr_magic;
 210         int has_extents = 0;
 211         int islnk = 0;
 212         __u32 *eaf, *eat;
 213
 214         if (hostorder && LINUX_S_ISLNK(f->i_mode))
 215                 islnk = 1;
 216         t->i_mode = ext2fs_swab16(f->i_mode);
 217         if (!hostorder && LINUX_S_ISLNK(t->i_mode))
 218                 islnk = 1;
 219         t->i_uid = ext2fs_swab16(f->i_uid);
 220         t->i_size = ext2fs_swab32(f->i_size);
 221         t->i_atime = ext2fs_swab32(f->i_atime);
 222         t->i_ctime = ext2fs_swab32(f->i_ctime);
 223         t->i_mtime = ext2fs_swab32(f->i_mtime);
 224         t->i_dtime = ext2fs_swab32(f->i_dtime);
 225         t->i_gid = ext2fs_swab16(f->i_gid);
 226         t->i_links_count = ext2fs_swab16(f->i_links_count);
 227         t->i_file_acl = ext2fs_swab32(f->i_file_acl);
 228         if (hostorder)
 229                 has_data_blocks = ext2fs_inode_data_blocks(fs,
 230                                            (struct ext2_inode *) f);
 231         t->i_blocks = ext2fs_swab32(f->i_blocks);
 232         if (!hostorder)
 233                 has_data_blocks = ext2fs_inode_data_blocks(fs,
 234                                            (struct ext2_inode *) t);
 235         if (hostorder && (f->i_flags & EXT4_EXTENTS_FL))
 236                 has_extents = 1;
 237         t->i_flags = ext2fs_swab32(f->i_flags);
 238         if (!hostorder && (t->i_flags & EXT4_EXTENTS_FL))
 239                 has_extents = 1;
 240         t->i_dir_acl = ext2fs_swab32(f->i_dir_acl);
 241         /* extent data are swapped on access, not here */
 242         if (!has_extents && (!islnk || has_data_blocks)) {
 243                 for (i = 0; i < EXT2_N_BLOCKS; i++)
 244                         t->i_block[i] = ext2fs_swab32(f->i_block[i]);
 245         } else if (t != f) {
 246                 for (i = 0; i < EXT2_N_BLOCKS; i++)
 247                         t->i_block[i] = f->i_block[i];
 248         }
 249         t->i_generation = ext2fs_swab32(f->i_generation);
 250         t->i_faddr = ext2fs_swab32(f->i_faddr);
 251
 252         switch (fs->super->s_creator_os) {
 253         case EXT2_OS_LINUX:
 254                 t->osd1.linux1.l_i_version =
 255                         ext2fs_swab32(f->osd1.linux1.l_i_version);
 256                 t->osd2.linux2.l_i_blocks_hi =
 257                         ext2fs_swab16(f->osd2.linux2.l_i_blocks_hi);
 258                 t->osd2.linux2.l_i_file_acl_high =
 259                         ext2fs_swab16(f->osd2.linux2.l_i_file_acl_high);
 260                 t->osd2.linux2.l_i_uid_high =
 261                   ext2fs_swab16 (f->osd2.linux2.l_i_uid_high);
 262                 t->osd2.linux2.l_i_gid_high =
 263                   ext2fs_swab16 (f->osd2.linux2.l_i_gid_high);
 264                 t->osd2.linux2.l_i_checksum_lo =
 265                         ext2fs_swab16(f->osd2.linux2.l_i_checksum_lo);
 266                 break;
 267         case EXT2_OS_HURD:
 268                 t->osd1.hurd1.h_i_translator =
 269                   ext2fs_swab32 (f->osd1.hurd1.h_i_translator);
 270                 t->osd2.hurd2.h_i_frag = f->osd2.hurd2.h_i_frag;
 271                 t->osd2.hurd2.h_i_fsize = f->osd2.hurd2.h_i_fsize;
 272                 t->osd2.hurd2.h_i_mode_high =
 273                   ext2fs_swab16 (f->osd2.hurd2.h_i_mode_high);
 274                 t->osd2.hurd2.h_i_uid_high =
 275                   ext2fs_swab16 (f->osd2.hurd2.h_i_uid_high);
 276                 t->osd2.hurd2.h_i_gid_high =
 277                   ext2fs_swab16 (f->osd2.hurd2.h_i_gid_high);
 278                 t->osd2.hurd2.h_i_author =
 279                   ext2fs_swab32 (f->osd2.hurd2.h_i_author);
 280                 break;
 281         default:
 282                 break;
 283         }
 284
 285         if (bufsize < (int) (sizeof(struct ext2_inode) + sizeof(__u16)))
 286                 return; /* no i_extra_isize field */
 287
 288         if (hostorder)
 289                 extra_isize = f->i_extra_isize;
 290         t->i_extra_isize = ext2fs_swab16(f->i_extra_isize);
 291         if (!hostorder)
 292                 extra_isize = t->i_extra_isize;
 293         if (extra_isize > EXT2_INODE_SIZE(fs->super) -
 294                                 sizeof(struct ext2_inode)) {
 295                 /* this is error case: i_extra_size is too large */
 296                 return;
 297         }
 298
 299         if (extra_isize >= 4)
 300                 t->i_checksum_hi = ext2fs_swab16(f->i_checksum_hi);
 301         if (extra_isize >= 8)
 302                 t->i_ctime_extra = ext2fs_swab32(f->i_ctime_extra);
 303         if (extra_isize >= 12)
 304                 t->i_mtime_extra = ext2fs_swab32(f->i_mtime_extra);
 305         if (extra_isize >= 16)
 306                 t->i_atime_extra = ext2fs_swab32(f->i_atime_extra);
 307         if (extra_isize >= 20)
 308                 t->i_crtime = ext2fs_swab32(f->i_crtime);
 309         if (extra_isize >= 24)
 310                 t->i_crtime_extra = ext2fs_swab32(f->i_crtime_extra);
 311         if (extra_isize >= 28)
 312                 t->i_version_hi = ext2fs_swab32(f->i_version_hi);
 313
 314         i = sizeof(struct ext2_inode) + extra_isize + sizeof(__u32);
 315         if (bufsize < (int) i)
 316                 return; /* no space for EA magic */
 317
 318         eaf = (__u32 *) (((char *) f) + sizeof(struct ext2_inode) +
 319                                         extra_isize);
 320
 321         attr_magic = *eaf;
 322         if (!hostorder)
 323                 attr_magic = ext2fs_swab32(attr_magic);
 324
 325         if (attr_magic != EXT2_EXT_ATTR_MAGIC)
 326                 return; /* it seems no magic here */
 327
 328         eat = (__u32 *) (((char *) t) + sizeof(struct ext2_inode) +
 329                                         extra_isize);
 330         *eat = ext2fs_swab32(*eaf);
 331
 332         /* convert EA(s) */
 333         ext2fs_swap_ext_attr((char *) (eat + 1), (char *) (eaf + 1),
 334                              bufsize - sizeof(struct ext2_inode) -
 335                              extra_isize - sizeof(__u32), 0);
 336
 337 }
 338
 339 void ext2fs_swap_inode(ext2_filsys fs, struct ext2_inode *t,
 340                        struct ext2_inode *f, int hostorder)
 341 {
 342         ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) t,
 343                                 (struct ext2_inode_large *) f, hostorder,
 344                                 sizeof(struct ext2_inode));
 345 }
 346
 347 void ext2fs_swap_mmp(struct mmp_struct *mmp)
 348 {
 349         mmp->mmp_magic = ext2fs_swab32(mmp->mmp_magic);
 350         mmp->mmp_seq = ext2fs_swab32(mmp->mmp_seq);
 351         mmp->mmp_time = ext2fs_swab64(mmp->mmp_time);
 352         mmp->mmp_check_interval = ext2fs_swab16(mmp->mmp_check_interval);
 353 }
 354
 355 #endif