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 <stdio.h>
  13 #if HAVE_UNISTD_H
  14 #include <unistd.h>
  15 #endif
  16 #include <string.h>
  17 #include <time.h>
  18
  19 #include "ext2_fs.h"
  20 #include "ext2fs.h"
  21 #include <ext2fs/ext2_ext_attr.h>
  22
  23 #ifdef WORDS_BIGENDIAN
  24 void ext2fs_swap_super(struct ext2_super_block * sb)
  25 {
  26         int i;
  27         sb->s_inodes_count = ext2fs_swab32(sb->s_inodes_count);
  28         sb->s_blocks_count = ext2fs_swab32(sb->s_blocks_count);
  29         sb->s_r_blocks_count = ext2fs_swab32(sb->s_r_blocks_count);
  30         sb->s_free_blocks_count = ext2fs_swab32(sb->s_free_blocks_count);
  31         sb->s_free_inodes_count = ext2fs_swab32(sb->s_free_inodes_count);
  32         sb->s_first_data_block = ext2fs_swab32(sb->s_first_data_block);
  33         sb->s_log_block_size = ext2fs_swab32(sb->s_log_block_size);
  34         sb->s_log_frag_size = ext2fs_swab32(sb->s_log_frag_size);
  35         sb->s_blocks_per_group = ext2fs_swab32(sb->s_blocks_per_group);
  36         sb->s_frags_per_group = ext2fs_swab32(sb->s_frags_per_group);
  37         sb->s_inodes_per_group = ext2fs_swab32(sb->s_inodes_per_group);
  38         sb->s_mtime = ext2fs_swab32(sb->s_mtime);
  39         sb->s_wtime = ext2fs_swab32(sb->s_wtime);
  40         sb->s_mnt_count = ext2fs_swab16(sb->s_mnt_count);
  41         sb->s_max_mnt_count = ext2fs_swab16(sb->s_max_mnt_count);
  42         sb->s_magic = ext2fs_swab16(sb->s_magic);
  43         sb->s_state = ext2fs_swab16(sb->s_state);
  44         sb->s_errors = ext2fs_swab16(sb->s_errors);
  45         sb->s_minor_rev_level = ext2fs_swab16(sb->s_minor_rev_level);
  46         sb->s_lastcheck = ext2fs_swab32(sb->s_lastcheck);
  47         sb->s_checkinterval = ext2fs_swab32(sb->s_checkinterval);
  48         sb->s_creator_os = ext2fs_swab32(sb->s_creator_os);
  49         sb->s_rev_level = ext2fs_swab32(sb->s_rev_level);
  50         sb->s_def_resuid = ext2fs_swab16(sb->s_def_resuid);
  51         sb->s_def_resgid = ext2fs_swab16(sb->s_def_resgid);
  52         sb->s_first_ino = ext2fs_swab32(sb->s_first_ino);
  53         sb->s_inode_size = ext2fs_swab16(sb->s_inode_size);
  54         sb->s_block_group_nr = ext2fs_swab16(sb->s_block_group_nr);
  55         sb->s_feature_compat = ext2fs_swab32(sb->s_feature_compat);
  56         sb->s_feature_incompat = ext2fs_swab32(sb->s_feature_incompat);
  57         sb->s_feature_ro_compat = ext2fs_swab32(sb->s_feature_ro_compat);
  58         sb->s_algorithm_usage_bitmap = ext2fs_swab32(sb->s_algorithm_usage_bitmap);
  59         sb->s_reserved_gdt_blocks = ext2fs_swab16(sb->s_reserved_gdt_blocks);
  60         sb->s_journal_inum = ext2fs_swab32(sb->s_journal_inum);
  61         sb->s_journal_dev = ext2fs_swab32(sb->s_journal_dev);
  62         sb->s_last_orphan = ext2fs_swab32(sb->s_last_orphan);
  63         sb->s_desc_size = ext2fs_swab16(sb->s_desc_size);
  64         sb->s_default_mount_opts = ext2fs_swab32(sb->s_default_mount_opts);
  65         sb->s_first_meta_bg = ext2fs_swab32(sb->s_first_meta_bg);
  66         sb->s_mkfs_time = ext2fs_swab32(sb->s_mkfs_time);
  67         sb->s_blocks_count_hi = ext2fs_swab32(sb->s_blocks_count_hi);
  68         sb->s_r_blocks_count_hi = ext2fs_swab32(sb->s_r_blocks_count_hi);
  69         sb->s_free_blocks_hi = ext2fs_swab32(sb->s_free_blocks_hi);
  70         sb->s_min_extra_isize = ext2fs_swab16(sb->s_min_extra_isize);
  71         sb->s_want_extra_isize = ext2fs_swab16(sb->s_want_extra_isize);
  72         sb->s_flags = ext2fs_swab32(sb->s_flags);
  73         sb->s_kbytes_written = ext2fs_swab64(sb->s_kbytes_written);
  74         sb->s_snapshot_inum = ext2fs_swab32(sb->s_snapshot_inum);
  75         sb->s_snapshot_id = ext2fs_swab32(sb->s_snapshot_id);
  76         sb->s_snapshot_r_blocks_count =
  77                 ext2fs_swab64(sb->s_snapshot_r_blocks_count);
  78         sb->s_snapshot_list = ext2fs_swab32(sb->s_snapshot_list);
  79         sb->s_usr_quota_inum = ext2fs_swab32(sb->s_usr_quota_inum);
  80         sb->s_grp_quota_inum = ext2fs_swab32(sb->s_grp_quota_inum);
  81
  82         for (i=0; i < 4; i++)
  83                 sb->s_hash_seed[i] = ext2fs_swab32(sb->s_hash_seed[i]);
  84
  85         /* if journal backup is for a valid extent-based journal... */
  86         if (!ext2fs_extent_header_verify(sb->s_jnl_blocks,
  87                                          sizeof(sb->s_jnl_blocks))) {
  88                 /* ... swap only the journal i_size */
  89                 sb->s_jnl_blocks[16] = ext2fs_swab32(sb->s_jnl_blocks[16]);
  90                 /* and the extent data is not swapped on read */
  91                 return;
  92         }
  93
  94         /* direct/indirect journal: swap it all */
  95         for (i=0; i < 17; i++)
  96                 sb->s_jnl_blocks[i] = ext2fs_swab32(sb->s_jnl_blocks[i]);
  97 }
  98
  99 void ext2fs_swap_group_desc(struct ext2_group_desc *gdp)
 100 {
 101         gdp->bg_block_bitmap = ext2fs_swab32(gdp->bg_block_bitmap);
 102         gdp->bg_inode_bitmap = ext2fs_swab32(gdp->bg_inode_bitmap);
 103         gdp->bg_inode_table = ext2fs_swab32(gdp->bg_inode_table);
 104         gdp->bg_free_blocks_count = ext2fs_swab16(gdp->bg_free_blocks_count);
 105         gdp->bg_free_inodes_count = ext2fs_swab16(gdp->bg_free_inodes_count);
 106         gdp->bg_used_dirs_count = ext2fs_swab16(gdp->bg_used_dirs_count);
 107         gdp->bg_flags = ext2fs_swab16(gdp->bg_flags);
 108         gdp->bg_itable_unused = ext2fs_swab16(gdp->bg_itable_unused);
 109         gdp->bg_checksum = ext2fs_swab16(gdp->bg_checksum);
 110 }
 111
 112 void ext2fs_swap_ext_attr_header(struct ext2_ext_attr_header *to_header,
 113                                  struct ext2_ext_attr_header *from_header)
 114 {
 115         int n;
 116
 117         to_header->h_magic    = ext2fs_swab32(from_header->h_magic);
 118         to_header->h_blocks   = ext2fs_swab32(from_header->h_blocks);
 119         to_header->h_refcount = ext2fs_swab32(from_header->h_refcount);
 120         to_header->h_hash     = ext2fs_swab32(from_header->h_hash);
 121         for (n = 0; n < 4; n++)
 122                 to_header->h_reserved[n] =
 123                         ext2fs_swab32(from_header->h_reserved[n]);
 124 }
 125
 126 void ext2fs_swap_ext_attr_entry(struct ext2_ext_attr_entry *to_entry,
 127                                 struct ext2_ext_attr_entry *from_entry)
 128 {
 129         to_entry->e_value_offs  = ext2fs_swab16(from_entry->e_value_offs);
 130         to_entry->e_value_block = ext2fs_swab32(from_entry->e_value_block);
 131         to_entry->e_value_size  = ext2fs_swab32(from_entry->e_value_size);
 132         to_entry->e_hash        = ext2fs_swab32(from_entry->e_hash);
 133 }
 134
 135 void ext2fs_swap_ext_attr(char *to, char *from, int bufsize, int has_header)
 136 {
 137         struct ext2_ext_attr_header *from_header =
 138                 (struct ext2_ext_attr_header *)from;
 139         struct ext2_ext_attr_header *to_header =
 140                 (struct ext2_ext_attr_header *)to;
 141         struct ext2_ext_attr_entry *from_entry, *to_entry;
 142         char *from_end = (char *)from_header + bufsize;
 143
 144         if (to_header != from_header)
 145                 memcpy(to_header, from_header, bufsize);
 146
 147         if (has_header) {
 148                 ext2fs_swap_ext_attr_header(to_header, from_header);
 149
 150                 from_entry = (struct ext2_ext_attr_entry *)(from_header+1);
 151                 to_entry   = (struct ext2_ext_attr_entry *)(to_header+1);
 152         } else {
 153                 from_entry = (struct ext2_ext_attr_entry *)from_header;
 154                 to_entry   = (struct ext2_ext_attr_entry *)to_header;
 155         }
 156
 157         while ((char *)from_entry < from_end && *(__u32 *)from_entry) {
 158                 ext2fs_swap_ext_attr_entry(to_entry, from_entry);
 159                 from_entry = EXT2_EXT_ATTR_NEXT(from_entry);
 160                 to_entry   = EXT2_EXT_ATTR_NEXT(to_entry);
 161         }
 162 }
 163
 164 void ext2fs_swap_inode_full(ext2_filsys fs, struct ext2_inode_large *t,
 165                             struct ext2_inode_large *f, int hostorder,
 166                             int bufsize)
 167 {
 168         unsigned i, has_data_blocks, extra_isize, attr_magic;
 169         int has_extents = 0;
 170         int islnk = 0;
 171         __u32 *eaf, *eat;
 172
 173         if (hostorder && LINUX_S_ISLNK(f->i_mode))
 174                 islnk = 1;
 175         t->i_mode = ext2fs_swab16(f->i_mode);
 176         if (!hostorder && LINUX_S_ISLNK(t->i_mode))
 177                 islnk = 1;
 178         t->i_uid = ext2fs_swab16(f->i_uid);
 179         t->i_size = ext2fs_swab32(f->i_size);
 180         t->i_atime = ext2fs_swab32(f->i_atime);
 181         t->i_ctime = ext2fs_swab32(f->i_ctime);
 182         t->i_mtime = ext2fs_swab32(f->i_mtime);
 183         t->i_dtime = ext2fs_swab32(f->i_dtime);
 184         t->i_gid = ext2fs_swab16(f->i_gid);
 185         t->i_links_count = ext2fs_swab16(f->i_links_count);
 186         t->i_file_acl = ext2fs_swab32(f->i_file_acl);
 187         if (hostorder)
 188                 has_data_blocks = ext2fs_inode_data_blocks(fs,
 189                                            (struct ext2_inode *) f);
 190         t->i_blocks = ext2fs_swab32(f->i_blocks);
 191         if (!hostorder)
 192                 has_data_blocks = ext2fs_inode_data_blocks(fs,
 193                                            (struct ext2_inode *) t);
 194         if (hostorder && (f->i_flags & EXT4_EXTENTS_FL))
 195                 has_extents = 1;
 196         t->i_flags = ext2fs_swab32(f->i_flags);
 197         if (!hostorder && (t->i_flags & EXT4_EXTENTS_FL))
 198                 has_extents = 1;
 199         t->i_dir_acl = ext2fs_swab32(f->i_dir_acl);
 200         /* extent data are swapped on access, not here */
 201         if (!has_extents && (!islnk || has_data_blocks)) {
 202                 for (i = 0; i < EXT2_N_BLOCKS; i++)
 203                         t->i_block[i] = ext2fs_swab32(f->i_block[i]);
 204         } else if (t != f) {
 205                 for (i = 0; i < EXT2_N_BLOCKS; i++)
 206                         t->i_block[i] = f->i_block[i];
 207         }
 208         t->i_generation = ext2fs_swab32(f->i_generation);
 209         t->i_faddr = ext2fs_swab32(f->i_faddr);
 210
 211         switch (fs->super->s_creator_os) {
 212         case EXT2_OS_LINUX:
 213                 t->osd1.linux1.l_i_version =
 214                         ext2fs_swab32(f->osd1.linux1.l_i_version);
 215                 t->osd2.linux2.l_i_blocks_hi =
 216                         ext2fs_swab16(f->osd2.linux2.l_i_blocks_hi);
 217                 t->osd2.linux2.l_i_file_acl_high =
 218                         ext2fs_swab16(f->osd2.linux2.l_i_file_acl_high);
 219                 t->osd2.linux2.l_i_uid_high =
 220                   ext2fs_swab16 (f->osd2.linux2.l_i_uid_high);
 221                 t->osd2.linux2.l_i_gid_high =
 222                   ext2fs_swab16 (f->osd2.linux2.l_i_gid_high);
 223                 t->osd2.linux2.l_i_reserved2 =
 224                         ext2fs_swab32(f->osd2.linux2.l_i_reserved2);
 225                 break;
 226         case EXT2_OS_HURD:
 227                 t->osd1.hurd1.h_i_translator =
 228                   ext2fs_swab32 (f->osd1.hurd1.h_i_translator);
 229                 t->osd2.hurd2.h_i_frag = f->osd2.hurd2.h_i_frag;
 230                 t->osd2.hurd2.h_i_fsize = f->osd2.hurd2.h_i_fsize;
 231                 t->osd2.hurd2.h_i_mode_high =
 232                   ext2fs_swab16 (f->osd2.hurd2.h_i_mode_high);
 233                 t->osd2.hurd2.h_i_uid_high =
 234                   ext2fs_swab16 (f->osd2.hurd2.h_i_uid_high);
 235                 t->osd2.hurd2.h_i_gid_high =
 236                   ext2fs_swab16 (f->osd2.hurd2.h_i_gid_high);
 237                 t->osd2.hurd2.h_i_author =
 238                   ext2fs_swab32 (f->osd2.hurd2.h_i_author);
 239                 break;
 240         default:
 241                 break;
 242         }
 243
 244         if (bufsize < (int) (sizeof(struct ext2_inode) + sizeof(__u16)))
 245                 return; /* no i_extra_isize field */
 246
 247         if (hostorder)
 248                 extra_isize = f->i_extra_isize;
 249         t->i_extra_isize = ext2fs_swab16(f->i_extra_isize);
 250         if (!hostorder)
 251                 extra_isize = t->i_extra_isize;
 252         if (extra_isize > EXT2_INODE_SIZE(fs->super) -
 253                                 sizeof(struct ext2_inode)) {
 254                 /* this is error case: i_extra_size is too large */
 255                 return;
 256         }
 257
 258         i = sizeof(struct ext2_inode) + extra_isize + sizeof(__u32);
 259         if (bufsize < (int) i)
 260                 return; /* no space for EA magic */
 261
 262         eaf = (__u32 *) (((char *) f) + sizeof(struct ext2_inode) +
 263                                         extra_isize);
 264
 265         attr_magic = *eaf;
 266         if (!hostorder)
 267                 attr_magic = ext2fs_swab32(attr_magic);
 268
 269         if (attr_magic != EXT2_EXT_ATTR_MAGIC)
 270                 return; /* it seems no magic here */
 271
 272         eat = (__u32 *) (((char *) t) + sizeof(struct ext2_inode) +
 273                                         extra_isize);
 274         *eat = ext2fs_swab32(*eaf);
 275
 276         /* convert EA(s) */
 277         ext2fs_swap_ext_attr((char *) (eat + 1), (char *) (eaf + 1),
 278                              bufsize - sizeof(struct ext2_inode) -
 279                              extra_isize - sizeof(__u32), 0);
 280
 281 }
 282
 283 void ext2fs_swap_inode(ext2_filsys fs, struct ext2_inode *t,
 284                        struct ext2_inode *f, int hostorder)
 285 {
 286         ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) t,
 287                                 (struct ext2_inode_large *) f, hostorder,
 288                                 sizeof(struct ext2_inode));
 289 }
 290
 291 #endif