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      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_cluster_size = ext2fs_swab32(sb->s_log_cluster_size);
     35 	sb->s_blocks_per_group = ext2fs_swab32(sb->s_blocks_per_group);
     36 	sb->s_clusters_per_group = ext2fs_swab32(sb->s_clusters_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_mmp_update_interval = ext2fs_swab16(sb->s_mmp_update_interval);
     74 	sb->s_mmp_block = ext2fs_swab64(sb->s_mmp_block);
     75 	sb->s_kbytes_written = ext2fs_swab64(sb->s_kbytes_written);
     76 	sb->s_snapshot_inum = ext2fs_swab32(sb->s_snapshot_inum);
     77 	sb->s_snapshot_id = ext2fs_swab32(sb->s_snapshot_id);
     78 	sb->s_snapshot_r_blocks_count =
     79 		ext2fs_swab64(sb->s_snapshot_r_blocks_count);
     80 	sb->s_snapshot_list = ext2fs_swab32(sb->s_snapshot_list);
     81 	sb->s_usr_quota_inum = ext2fs_swab32(sb->s_usr_quota_inum);
     82 	sb->s_grp_quota_inum = ext2fs_swab32(sb->s_grp_quota_inum);
     83 	sb->s_overhead_blocks = ext2fs_swab32(sb->s_overhead_blocks);
     84 	sb->s_checksum = ext2fs_swab32(sb->s_checksum);
     85 
     86 	for (i=0; i < 4; i++)
     87 		sb->s_hash_seed[i] = ext2fs_swab32(sb->s_hash_seed[i]);
     88 
     89 	/* if journal backup is for a valid extent-based journal... */
     90 	if (ext2fs_extent_header_verify(sb->s_jnl_blocks,
     91 					sizeof(sb->s_jnl_blocks)) == 0) {
     92 		/* ... swap only the journal i_size and i_size_high,
     93 		 * and the extent data is not swapped on read */
     94 		i = 15;
     95 	} else {
     96 		/* direct/indirect journal: swap it all */
     97 		i = 0;
     98 	}
     99 	for (; i < 17; i++)
    100 		sb->s_jnl_blocks[i] = ext2fs_swab32(sb->s_jnl_blocks[i]);
    101 }
    102 
    103 void ext2fs_swap_group_desc2(ext2_filsys fs, struct ext2_group_desc *gdp)
    104 {
    105 	struct ext4_group_desc *gdp4 = (struct ext4_group_desc *)gdp;
    106 
    107 	/* Do the 32-bit parts first */
    108 	gdp->bg_block_bitmap = ext2fs_swab32(gdp->bg_block_bitmap);
    109 	gdp->bg_inode_bitmap = ext2fs_swab32(gdp->bg_inode_bitmap);
    110 	gdp->bg_inode_table = ext2fs_swab32(gdp->bg_inode_table);
    111 	gdp->bg_free_blocks_count = ext2fs_swab16(gdp->bg_free_blocks_count);
    112 	gdp->bg_free_inodes_count = ext2fs_swab16(gdp->bg_free_inodes_count);
    113 	gdp->bg_used_dirs_count = ext2fs_swab16(gdp->bg_used_dirs_count);
    114 	gdp->bg_flags = ext2fs_swab16(gdp->bg_flags);
    115 	gdp->bg_exclude_bitmap_lo = ext2fs_swab32(gdp->bg_exclude_bitmap_lo);
    116 	gdp->bg_block_bitmap_csum_lo =
    117 		ext2fs_swab16(gdp->bg_block_bitmap_csum_lo);
    118 	gdp->bg_inode_bitmap_csum_lo =
    119 		ext2fs_swab16(gdp->bg_inode_bitmap_csum_lo);
    120 	gdp->bg_itable_unused = ext2fs_swab16(gdp->bg_itable_unused);
    121 	gdp->bg_checksum = ext2fs_swab16(gdp->bg_checksum);
    122 	/* If we're 32-bit, we're done */
    123 	if (fs == NULL || EXT2_DESC_SIZE(fs->super) < EXT2_MIN_DESC_SIZE_64BIT)
    124 		return;
    125 
    126 	/* Swap the 64-bit parts */
    127 	gdp4->bg_block_bitmap_hi = ext2fs_swab32(gdp4->bg_block_bitmap_hi);
    128 	gdp4->bg_inode_bitmap_hi = ext2fs_swab32(gdp4->bg_inode_bitmap_hi);
    129 	gdp4->bg_inode_table_hi = ext2fs_swab32(gdp4->bg_inode_table_hi);
    130 	gdp4->bg_free_blocks_count_hi =
    131 		ext2fs_swab16(gdp4->bg_free_blocks_count_hi);
    132 	gdp4->bg_free_inodes_count_hi =
    133 		ext2fs_swab16(gdp4->bg_free_inodes_count_hi);
    134 	gdp4->bg_used_dirs_count_hi =
    135 		ext2fs_swab16(gdp4->bg_used_dirs_count_hi);
    136 	gdp4->bg_itable_unused_hi = ext2fs_swab16(gdp4->bg_itable_unused_hi);
    137 	gdp4->bg_exclude_bitmap_hi = ext2fs_swab16(gdp4->bg_exclude_bitmap_hi);
    138 	gdp4->bg_block_bitmap_csum_hi =
    139 		ext2fs_swab16(gdp4->bg_block_bitmap_csum_hi);
    140 	gdp4->bg_inode_bitmap_csum_hi =
    141 		ext2fs_swab16(gdp4->bg_inode_bitmap_csum_hi);
    142 }
    143 
    144 void ext2fs_swap_group_desc(struct ext2_group_desc *gdp)
    145 {
    146 	ext2fs_swap_group_desc2(0, gdp);
    147 }
    148 
    149 
    150 void ext2fs_swap_ext_attr_header(struct ext2_ext_attr_header *to_header,
    151 				 struct ext2_ext_attr_header *from_header)
    152 {
    153 	int n;
    154 
    155 	to_header->h_magic    = ext2fs_swab32(from_header->h_magic);
    156 	to_header->h_blocks   = ext2fs_swab32(from_header->h_blocks);
    157 	to_header->h_refcount = ext2fs_swab32(from_header->h_refcount);
    158 	to_header->h_hash     = ext2fs_swab32(from_header->h_hash);
    159 	for (n = 0; n < 4; n++)
    160 		to_header->h_reserved[n] =
    161 			ext2fs_swab32(from_header->h_reserved[n]);
    162 }
    163 
    164 void ext2fs_swap_ext_attr_entry(struct ext2_ext_attr_entry *to_entry,
    165 				struct ext2_ext_attr_entry *from_entry)
    166 {
    167 	to_entry->e_value_offs  = ext2fs_swab16(from_entry->e_value_offs);
    168 	to_entry->e_value_block = ext2fs_swab32(from_entry->e_value_block);
    169 	to_entry->e_value_size  = ext2fs_swab32(from_entry->e_value_size);
    170 	to_entry->e_hash	= ext2fs_swab32(from_entry->e_hash);
    171 }
    172 
    173 void ext2fs_swap_ext_attr(char *to, char *from, int bufsize, int has_header)
    174 {
    175 	struct ext2_ext_attr_header *from_header =
    176 		(struct ext2_ext_attr_header *)from;
    177 	struct ext2_ext_attr_header *to_header =
    178 		(struct ext2_ext_attr_header *)to;
    179 	struct ext2_ext_attr_entry *from_entry, *to_entry;
    180 	char *from_end = (char *)from_header + bufsize;
    181 
    182 	if (to_header != from_header)
    183 		memcpy(to_header, from_header, bufsize);
    184 
    185 	if (has_header) {
    186 		ext2fs_swap_ext_attr_header(to_header, from_header);
    187 
    188 		from_entry = (struct ext2_ext_attr_entry *)(from_header+1);
    189 		to_entry   = (struct ext2_ext_attr_entry *)(to_header+1);
    190 	} else {
    191 		from_entry = (struct ext2_ext_attr_entry *)from_header;
    192 		to_entry   = (struct ext2_ext_attr_entry *)to_header;
    193 	}
    194 
    195 	while ((char *)from_entry < from_end && *(__u32 *)from_entry) {
    196 		ext2fs_swap_ext_attr_entry(to_entry, from_entry);
    197 		from_entry = EXT2_EXT_ATTR_NEXT(from_entry);
    198 		to_entry   = EXT2_EXT_ATTR_NEXT(to_entry);
    199 	}
    200 }
    201 
    202 void ext2fs_swap_inode_full(ext2_filsys fs, struct ext2_inode_large *t,
    203 			    struct ext2_inode_large *f, int hostorder,
    204 			    int bufsize)
    205 {
    206 	unsigned i, has_data_blocks, extra_isize, attr_magic;
    207 	int has_extents = 0;
    208 	int islnk = 0;
    209 	__u32 *eaf, *eat;
    210 
    211 	if (hostorder && LINUX_S_ISLNK(f->i_mode))
    212 		islnk = 1;
    213 	t->i_mode = ext2fs_swab16(f->i_mode);
    214 	if (!hostorder && LINUX_S_ISLNK(t->i_mode))
    215 		islnk = 1;
    216 	t->i_uid = ext2fs_swab16(f->i_uid);
    217 	t->i_size = ext2fs_swab32(f->i_size);
    218 	t->i_atime = ext2fs_swab32(f->i_atime);
    219 	t->i_ctime = ext2fs_swab32(f->i_ctime);
    220 	t->i_mtime = ext2fs_swab32(f->i_mtime);
    221 	t->i_dtime = ext2fs_swab32(f->i_dtime);
    222 	t->i_gid = ext2fs_swab16(f->i_gid);
    223 	t->i_links_count = ext2fs_swab16(f->i_links_count);
    224 	t->i_file_acl = ext2fs_swab32(f->i_file_acl);
    225 	if (hostorder)
    226 		has_data_blocks = ext2fs_inode_data_blocks(fs,
    227 					   (struct ext2_inode *) f);
    228 	t->i_blocks = ext2fs_swab32(f->i_blocks);
    229 	if (!hostorder)
    230 		has_data_blocks = ext2fs_inode_data_blocks(fs,
    231 					   (struct ext2_inode *) t);
    232 	if (hostorder && (f->i_flags & EXT4_EXTENTS_FL))
    233 		has_extents = 1;
    234 	t->i_flags = ext2fs_swab32(f->i_flags);
    235 	if (!hostorder && (t->i_flags & EXT4_EXTENTS_FL))
    236 		has_extents = 1;
    237 	t->i_dir_acl = ext2fs_swab32(f->i_dir_acl);
    238 	/* extent data are swapped on access, not here */
    239 	if (!has_extents && (!islnk || has_data_blocks)) {
    240 		for (i = 0; i < EXT2_N_BLOCKS; i++)
    241 			t->i_block[i] = ext2fs_swab32(f->i_block[i]);
    242 	} else if (t != f) {
    243 		for (i = 0; i < EXT2_N_BLOCKS; i++)
    244 			t->i_block[i] = f->i_block[i];
    245 	}
    246 	t->i_generation = ext2fs_swab32(f->i_generation);
    247 	t->i_faddr = ext2fs_swab32(f->i_faddr);
    248 
    249 	switch (fs->super->s_creator_os) {
    250 	case EXT2_OS_LINUX:
    251 		t->osd1.linux1.l_i_version =
    252 			ext2fs_swab32(f->osd1.linux1.l_i_version);
    253 		t->osd2.linux2.l_i_blocks_hi =
    254 			ext2fs_swab16(f->osd2.linux2.l_i_blocks_hi);
    255 		t->osd2.linux2.l_i_file_acl_high =
    256 			ext2fs_swab16(f->osd2.linux2.l_i_file_acl_high);
    257 		t->osd2.linux2.l_i_uid_high =
    258 		  ext2fs_swab16 (f->osd2.linux2.l_i_uid_high);
    259 		t->osd2.linux2.l_i_gid_high =
    260 		  ext2fs_swab16 (f->osd2.linux2.l_i_gid_high);
    261 		t->osd2.linux2.l_i_checksum_lo =
    262 			ext2fs_swab16(f->osd2.linux2.l_i_checksum_lo);
    263 		break;
    264 	case EXT2_OS_HURD:
    265 		t->osd1.hurd1.h_i_translator =
    266 		  ext2fs_swab32 (f->osd1.hurd1.h_i_translator);
    267 		t->osd2.hurd2.h_i_frag = f->osd2.hurd2.h_i_frag;
    268 		t->osd2.hurd2.h_i_fsize = f->osd2.hurd2.h_i_fsize;
    269 		t->osd2.hurd2.h_i_mode_high =
    270 		  ext2fs_swab16 (f->osd2.hurd2.h_i_mode_high);
    271 		t->osd2.hurd2.h_i_uid_high =
    272 		  ext2fs_swab16 (f->osd2.hurd2.h_i_uid_high);
    273 		t->osd2.hurd2.h_i_gid_high =
    274 		  ext2fs_swab16 (f->osd2.hurd2.h_i_gid_high);
    275 		t->osd2.hurd2.h_i_author =
    276 		  ext2fs_swab32 (f->osd2.hurd2.h_i_author);
    277 		break;
    278 	default:
    279 		break;
    280 	}
    281 
    282 	if (bufsize < (int) (sizeof(struct ext2_inode) + sizeof(__u16)))
    283 		return; /* no i_extra_isize field */
    284 
    285 	if (hostorder)
    286 		extra_isize = f->i_extra_isize;
    287 	t->i_extra_isize = ext2fs_swab16(f->i_extra_isize);
    288 	if (!hostorder)
    289 		extra_isize = t->i_extra_isize;
    290 	if (extra_isize > EXT2_INODE_SIZE(fs->super) -
    291 				sizeof(struct ext2_inode)) {
    292 		/* this is error case: i_extra_size is too large */
    293 		return;
    294 	}
    295 
    296 	if (extra_isize >= 4)
    297 		t->i_checksum_hi = ext2fs_swab16(f->i_checksum_hi);
    298 	if (extra_isize >= 8)
    299 		t->i_ctime_extra = ext2fs_swab32(f->i_ctime_extra);
    300 	if (extra_isize >= 12)
    301 		t->i_mtime_extra = ext2fs_swab32(f->i_mtime_extra);
    302 	if (extra_isize >= 16)
    303 		t->i_atime_extra = ext2fs_swab32(f->i_atime_extra);
    304 	if (extra_isize >= 20)
    305 		t->i_crtime = ext2fs_swab32(f->i_crtime);
    306 	if (extra_isize >= 24)
    307 		t->i_crtime_extra = ext2fs_swab32(f->i_crtime_extra);
    308 	if (extra_isize >= 28)
    309 		t->i_version_hi = ext2fs_swab32(f->i_version_hi);
    310 
    311 	i = sizeof(struct ext2_inode) + extra_isize + sizeof(__u32);
    312 	if (bufsize < (int) i)
    313 		return; /* no space for EA magic */
    314 
    315 	eaf = (__u32 *) (((char *) f) + sizeof(struct ext2_inode) +
    316 					extra_isize);
    317 
    318 	attr_magic = *eaf;
    319 	if (!hostorder)
    320 		attr_magic = ext2fs_swab32(attr_magic);
    321 
    322 	if (attr_magic != EXT2_EXT_ATTR_MAGIC)
    323 		return; /* it seems no magic here */
    324 
    325 	eat = (__u32 *) (((char *) t) + sizeof(struct ext2_inode) +
    326 					extra_isize);
    327 	*eat = ext2fs_swab32(*eaf);
    328 
    329 	/* convert EA(s) */
    330 	ext2fs_swap_ext_attr((char *) (eat + 1), (char *) (eaf + 1),
    331 			     bufsize - sizeof(struct ext2_inode) -
    332 			     extra_isize - sizeof(__u32), 0);
    333 
    334 }
    335 
    336 void ext2fs_swap_inode(ext2_filsys fs, struct ext2_inode *t,
    337 		       struct ext2_inode *f, int hostorder)
    338 {
    339 	ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) t,
    340 				(struct ext2_inode_large *) f, hostorder,
    341 				sizeof(struct ext2_inode));
    342 }
    343 
    344 void ext2fs_swap_mmp(struct mmp_struct *mmp)
    345 {
    346 	mmp->mmp_magic = ext2fs_swab32(mmp->mmp_magic);
    347 	mmp->mmp_seq = ext2fs_swab32(mmp->mmp_seq);
    348 	mmp->mmp_time = ext2fs_swab64(mmp->mmp_time);
    349 	mmp->mmp_check_interval = ext2fs_swab16(mmp->mmp_check_interval);
    350 }
    351 
    352 #endif
    353