text: /*
   * swapfs.c --- swap ext2 filesystem data structures
   *
   * Copyright (C) 1995, 1996, 2002 Theodore Ts'o.
   *
   * %Begin-Header%
   * This file may be redistributed under the terms of the GNU Library
   * General Public License, version 2.
   * %End-Header%
   */
  
  #include "config.h"
  #include <stdio.h>
  #if HAVE_UNISTD_H
  #include <unistd.h>
  #endif
  #include <string.h>
  #include <time.h>
  
  #include "ext2_fs.h"
  #include "ext2fs.h"
  #include <ext2fs/ext2_ext_attr.h>
  
  #ifdef WORDS_BIGENDIAN
  void ext2fs_swap_super(struct ext2_super_block * sb)
  {
    	int i;
  	sb->s_inodes_count = ext2fs_swab32(sb->s_inodes_count);
  	sb->s_blocks_count = ext2fs_swab32(sb->s_blocks_count);
  	sb->s_r_blocks_count = ext2fs_swab32(sb->s_r_blocks_count);
  	sb->s_free_blocks_count = ext2fs_swab32(sb->s_free_blocks_count);
  	sb->s_free_inodes_count = ext2fs_swab32(sb->s_free_inodes_count);
  	sb->s_first_data_block = ext2fs_swab32(sb->s_first_data_block);
  	sb->s_log_block_size = ext2fs_swab32(sb->s_log_block_size);
  	sb->s_log_cluster_size = ext2fs_swab32(sb->s_log_cluster_size);
  	sb->s_blocks_per_group = ext2fs_swab32(sb->s_blocks_per_group);
  	sb->s_clusters_per_group = ext2fs_swab32(sb->s_clusters_per_group);
  	sb->s_inodes_per_group = ext2fs_swab32(sb->s_inodes_per_group);
  	sb->s_mtime = ext2fs_swab32(sb->s_mtime);
  	sb->s_wtime = ext2fs_swab32(sb->s_wtime);
  	sb->s_mnt_count = ext2fs_swab16(sb->s_mnt_count);
  	sb->s_max_mnt_count = ext2fs_swab16(sb->s_max_mnt_count);
  	sb->s_magic = ext2fs_swab16(sb->s_magic);
  	sb->s_state = ext2fs_swab16(sb->s_state);
  	sb->s_errors = ext2fs_swab16(sb->s_errors);
  	sb->s_minor_rev_level = ext2fs_swab16(sb->s_minor_rev_level);
  	sb->s_lastcheck = ext2fs_swab32(sb->s_lastcheck);
  	sb->s_checkinterval = ext2fs_swab32(sb->s_checkinterval);
  	sb->s_creator_os = ext2fs_swab32(sb->s_creator_os);
  	sb->s_rev_level = ext2fs_swab32(sb->s_rev_level);
  	sb->s_def_resuid = ext2fs_swab16(sb->s_def_resuid);
  	sb->s_def_resgid = ext2fs_swab16(sb->s_def_resgid);
  	sb->s_first_ino = ext2fs_swab32(sb->s_first_ino);
  	sb->s_inode_size = ext2fs_swab16(sb->s_inode_size);
  	sb->s_block_group_nr = ext2fs_swab16(sb->s_block_group_nr);
  	sb->s_feature_compat = ext2fs_swab32(sb->s_feature_compat);
  	sb->s_feature_incompat = ext2fs_swab32(sb->s_feature_incompat);
  	sb->s_feature_ro_compat = ext2fs_swab32(sb->s_feature_ro_compat);
  	sb->s_algorithm_usage_bitmap = ext2fs_swab32(sb->s_algorithm_usage_bitmap);
  	sb->s_reserved_gdt_blocks = ext2fs_swab16(sb->s_reserved_gdt_blocks);
  	sb->s_journal_inum = ext2fs_swab32(sb->s_journal_inum);
  	sb->s_journal_dev = ext2fs_swab32(sb->s_journal_dev);
  	sb->s_last_orphan = ext2fs_swab32(sb->s_last_orphan);
  	sb->s_desc_size = ext2fs_swab16(sb->s_desc_size);
  	sb->s_default_mount_opts = ext2fs_swab32(sb->s_default_mount_opts);
  	sb->s_first_meta_bg = ext2fs_swab32(sb->s_first_meta_bg);
  	sb->s_mkfs_time = ext2fs_swab32(sb->s_mkfs_time);
  	sb->s_blocks_count_hi = ext2fs_swab32(sb->s_blocks_count_hi);
  	sb->s_r_blocks_count_hi = ext2fs_swab32(sb->s_r_blocks_count_hi);
  	sb->s_free_blocks_hi = ext2fs_swab32(sb->s_free_blocks_hi);
  	sb->s_min_extra_isize = ext2fs_swab16(sb->s_min_extra_isize);
  	sb->s_want_extra_isize = ext2fs_swab16(sb->s_want_extra_isize);
  	sb->s_flags = ext2fs_swab32(sb->s_flags);
  	sb->s_mmp_update_interval = ext2fs_swab16(sb->s_mmp_update_interval);
  	sb->s_mmp_block = ext2fs_swab64(sb->s_mmp_block);
  	sb->s_kbytes_written = ext2fs_swab64(sb->s_kbytes_written);
  	sb->s_snapshot_inum = ext2fs_swab32(sb->s_snapshot_inum);
  	sb->s_snapshot_id = ext2fs_swab32(sb->s_snapshot_id);
  	sb->s_snapshot_r_blocks_count =
  		ext2fs_swab64(sb->s_snapshot_r_blocks_count);
  	sb->s_snapshot_list = ext2fs_swab32(sb->s_snapshot_list);
  	sb->s_usr_quota_inum = ext2fs_swab32(sb->s_usr_quota_inum);
  	sb->s_grp_quota_inum = ext2fs_swab32(sb->s_grp_quota_inum);
  	sb->s_overhead_blocks = ext2fs_swab32(sb->s_overhead_blocks);
  	sb->s_checksum = ext2fs_swab32(sb->s_checksum);
  
  	for (i=0; i < 4; i++)
  		sb->s_hash_seed[i] = ext2fs_swab32(sb->s_hash_seed[i]);
  
  	/* if journal backup is for a valid extent-based journal... */
  	if (ext2fs_extent_header_verify(sb->s_jnl_blocks,
  					sizeof(sb->s_jnl_blocks)) == 0) {
  		/* ... swap only the journal i_size and i_size_high,
  		 * and the extent data is not swapped on read */
  		i = 15;
  	} else {
  		/* direct/indirect journal: swap it all */
  		i = 0;
  	}
  	for (; i < 17; i++)
  		sb->s_jnl_blocks[i] = ext2fs_swab32(sb->s_jnl_blocks[i]);
  	sb->s_backup_bgs[0] = ext2fs_swab32(sb->s_backup_bgs[0]);
  	sb->s_backup_bgs[1] = ext2fs_swab32(sb->s_backup_bgs[1]);
  	sb->s_checksum_seed = ext2fs_swab32(sb->s_checksum_seed);
  }
  
  void ext2fs_swap_group_desc2(ext2_filsys fs, struct ext2_group_desc *gdp)
  {
  	struct ext4_group_desc *gdp4 = (struct ext4_group_desc *)gdp;
  
  	/* Do the 32-bit parts first */
  	gdp->bg_block_bitmap = ext2fs_swab32(gdp->bg_block_bitmap);
  	gdp->bg_inode_bitmap = ext2fs_swab32(gdp->bg_inode_bitmap);
  	gdp->bg_inode_table = ext2fs_swab32(gdp->bg_inode_table);
  	gdp->bg_free_blocks_count = ext2fs_swab16(gdp->bg_free_blocks_count);
  	gdp->bg_free_inodes_count = ext2fs_swab16(gdp->bg_free_inodes_count);
  	gdp->bg_used_dirs_count = ext2fs_swab16(gdp->bg_used_dirs_count);
  	gdp->bg_flags = ext2fs_swab16(gdp->bg_flags);
  	gdp->bg_exclude_bitmap_lo = ext2fs_swab32(gdp->bg_exclude_bitmap_lo);
  	gdp->bg_block_bitmap_csum_lo =
  		ext2fs_swab16(gdp->bg_block_bitmap_csum_lo);
  	gdp->bg_inode_bitmap_csum_lo =
  		ext2fs_swab16(gdp->bg_inode_bitmap_csum_lo);
  	gdp->bg_itable_unused = ext2fs_swab16(gdp->bg_itable_unused);
  	gdp->bg_checksum = ext2fs_swab16(gdp->bg_checksum);
  	/* If we're 32-bit, we're done */
  	if (fs == NULL || EXT2_DESC_SIZE(fs->super) < EXT2_MIN_DESC_SIZE_64BIT)
  		return;
  
  	/* Swap the 64-bit parts */
  	gdp4->bg_block_bitmap_hi = ext2fs_swab32(gdp4->bg_block_bitmap_hi);
  	gdp4->bg_inode_bitmap_hi = ext2fs_swab32(gdp4->bg_inode_bitmap_hi);
  	gdp4->bg_inode_table_hi = ext2fs_swab32(gdp4->bg_inode_table_hi);
  	gdp4->bg_free_blocks_count_hi =
  		ext2fs_swab16(gdp4->bg_free_blocks_count_hi);
  	gdp4->bg_free_inodes_count_hi =
  		ext2fs_swab16(gdp4->bg_free_inodes_count_hi);
  	gdp4->bg_used_dirs_count_hi =
  		ext2fs_swab16(gdp4->bg_used_dirs_count_hi);
  	gdp4->bg_itable_unused_hi = ext2fs_swab16(gdp4->bg_itable_unused_hi);
  	gdp4->bg_exclude_bitmap_hi = ext2fs_swab16(gdp4->bg_exclude_bitmap_hi);
  	gdp4->bg_block_bitmap_csum_hi =
  		ext2fs_swab16(gdp4->bg_block_bitmap_csum_hi);
  	gdp4->bg_inode_bitmap_csum_hi =
  		ext2fs_swab16(gdp4->bg_inode_bitmap_csum_hi);
  }
  
  void ext2fs_swap_group_desc(struct ext2_group_desc *gdp)
  {
  	ext2fs_swap_group_desc2(0, gdp);
  }
  
  
  void ext2fs_swap_ext_attr_header(struct ext2_ext_attr_header *to_header,
  				 struct ext2_ext_attr_header *from_header)
  {
  	int n;
  
  	to_header->h_magic    = ext2fs_swab32(from_header->h_magic);
  	to_header->h_blocks   = ext2fs_swab32(from_header->h_blocks);
  	to_header->h_refcount = ext2fs_swab32(from_header->h_refcount);
  	to_header->h_hash     = ext2fs_swab32(from_header->h_hash);
  	to_header->h_checksum = ext2fs_swab32(from_header->h_checksum);
  	for (n = 0; n < 3; n++)
  		to_header->h_reserved[n] =
  			ext2fs_swab32(from_header->h_reserved[n]);
  }
  
  void ext2fs_swap_ext_attr_entry(struct ext2_ext_attr_entry *to_entry,
  				struct ext2_ext_attr_entry *from_entry)
  {
  	to_entry->e_value_offs  = ext2fs_swab16(from_entry->e_value_offs);
  	to_entry->e_value_block = ext2fs_swab32(from_entry->e_value_block);
  	to_entry->e_value_size  = ext2fs_swab32(from_entry->e_value_size);
  	to_entry->e_hash	= ext2fs_swab32(from_entry->e_hash);
  }
  
  void ext2fs_swap_ext_attr(char *to, char *from, int bufsize, int has_header)
  {
  	struct ext2_ext_attr_header *from_header =
  		(struct ext2_ext_attr_header *)from;
  	struct ext2_ext_attr_header *to_header =
  		(struct ext2_ext_attr_header *)to;
  	struct ext2_ext_attr_entry *from_entry, *to_entry;
  	char *from_end = (char *)from_header + bufsize;
  
  	if (to_header != from_header)
  		memcpy(to_header, from_header, bufsize);
  
  	if (has_header) {
  		ext2fs_swap_ext_attr_header(to_header, from_header);
  
  		from_entry = (struct ext2_ext_attr_entry *)(from_header+1);
  		to_entry   = (struct ext2_ext_attr_entry *)(to_header+1);
  	} else {
  		from_entry = (struct ext2_ext_attr_entry *)from_header;
  		to_entry   = (struct ext2_ext_attr_entry *)to_header;
  	}
  
  	while ((char *)from_entry < from_end &&
  	       (char *)EXT2_EXT_ATTR_NEXT(from_entry) <= from_end &&
  	       *(__u32 *)from_entry) {
  		ext2fs_swap_ext_attr_entry(to_entry, from_entry);
  		from_entry = EXT2_EXT_ATTR_NEXT(from_entry);
  		to_entry   = EXT2_EXT_ATTR_NEXT(to_entry);
  	}
  }
  
  void ext2fs_swap_inode_full(ext2_filsys fs, struct ext2_inode_large *t,
  			    struct ext2_inode_large *f, int hostorder,
  			    int bufsize)
  {
  	unsigned i, has_data_blocks, extra_isize, attr_magic;
  	int has_extents = 0;
  	int has_inline_data = 0;
  	int islnk = 0;
  	int inode_size;
  	__u32 *eaf, *eat;
  
  	if (hostorder && LINUX_S_ISLNK(f->i_mode))
  		islnk = 1;
  	t->i_mode = ext2fs_swab16(f->i_mode);
  	if (!hostorder && LINUX_S_ISLNK(t->i_mode))
  		islnk = 1;
  	t->i_uid = ext2fs_swab16(f->i_uid);
  	t->i_size = ext2fs_swab32(f->i_size);
  	t->i_atime = ext2fs_swab32(f->i_atime);
  	t->i_ctime = ext2fs_swab32(f->i_ctime);
  	t->i_mtime = ext2fs_swab32(f->i_mtime);
  	t->i_dtime = ext2fs_swab32(f->i_dtime);
  	t->i_gid = ext2fs_swab16(f->i_gid);
  	t->i_links_count = ext2fs_swab16(f->i_links_count);
  	t->i_file_acl = ext2fs_swab32(f->i_file_acl);
  	if (hostorder)
  		has_data_blocks = ext2fs_inode_data_blocks(fs,
  					   (struct ext2_inode *) f);
  	t->i_blocks = ext2fs_swab32(f->i_blocks);
  	if (!hostorder)
  		has_data_blocks = ext2fs_inode_data_blocks(fs,
  					   (struct ext2_inode *) t);
  	if (hostorder && (f->i_flags & EXT4_EXTENTS_FL))
  		has_extents = 1;
  	if (hostorder && (f->i_flags & EXT4_INLINE_DATA_FL))
  		has_inline_data = 1;
  	t->i_flags = ext2fs_swab32(f->i_flags);
  	if (!hostorder && (t->i_flags & EXT4_EXTENTS_FL))
  		has_extents = 1;
  	if (!hostorder && (t->i_flags & EXT4_INLINE_DATA_FL))
  		has_inline_data = 1;
  	t->i_dir_acl = ext2fs_swab32(f->i_dir_acl);
  	/*
  	 * Extent data and inline data are swapped on access, not here
  	 */
  	if (!has_extents && !has_inline_data && (!islnk || has_data_blocks)) {
  		for (i = 0; i < EXT2_N_BLOCKS; i++)
  			t->i_block[i] = ext2fs_swab32(f->i_block[i]);
  	} else if (t != f) {
  		for (i = 0; i < EXT2_N_BLOCKS; i++)
  			t->i_block[i] = f->i_block[i];
  	}
  	t->i_generation = ext2fs_swab32(f->i_generation);
  	t->i_faddr = ext2fs_swab32(f->i_faddr);
  
  	switch (fs->super->s_creator_os) {
  	case EXT2_OS_LINUX:
  		t->osd1.linux1.l_i_version =
  			ext2fs_swab32(f->osd1.linux1.l_i_version);
  		t->osd2.linux2.l_i_blocks_hi =
  			ext2fs_swab16(f->osd2.linux2.l_i_blocks_hi);
  		t->osd2.linux2.l_i_file_acl_high =
  			ext2fs_swab16(f->osd2.linux2.l_i_file_acl_high);
  		t->osd2.linux2.l_i_uid_high =
  		  ext2fs_swab16 (f->osd2.linux2.l_i_uid_high);
  		t->osd2.linux2.l_i_gid_high =
  		  ext2fs_swab16 (f->osd2.linux2.l_i_gid_high);
  		t->osd2.linux2.l_i_checksum_lo =
  			ext2fs_swab16(f->osd2.linux2.l_i_checksum_lo);
  		break;
  	case EXT2_OS_HURD:
  		t->osd1.hurd1.h_i_translator =
  		  ext2fs_swab32 (f->osd1.hurd1.h_i_translator);
  		t->osd2.hurd2.h_i_frag = f->osd2.hurd2.h_i_frag;
  		t->osd2.hurd2.h_i_fsize = f->osd2.hurd2.h_i_fsize;
  		t->osd2.hurd2.h_i_mode_high =
  		  ext2fs_swab16 (f->osd2.hurd2.h_i_mode_high);
  		t->osd2.hurd2.h_i_uid_high =
  		  ext2fs_swab16 (f->osd2.hurd2.h_i_uid_high);
  		t->osd2.hurd2.h_i_gid_high =
  		  ext2fs_swab16 (f->osd2.hurd2.h_i_gid_high);
  		t->osd2.hurd2.h_i_author =
  		  ext2fs_swab32 (f->osd2.hurd2.h_i_author);
  		break;
  	default:
  		break;
  	}
  
  	if (bufsize < (int) (sizeof(struct ext2_inode) + sizeof(__u16)))
  		return; /* no i_extra_isize field */
  
  	if (hostorder)
  		extra_isize = f->i_extra_isize;
  	t->i_extra_isize = ext2fs_swab16(f->i_extra_isize);
  	if (!hostorder)
  		extra_isize = t->i_extra_isize;
  	if (extra_isize > EXT2_INODE_SIZE(fs->super) -
  				sizeof(struct ext2_inode)) {
  		/* this is error case: i_extra_size is too large */
  		return;
  	}
  
  	inode_size = EXT2_GOOD_OLD_INODE_SIZE + extra_isize;
  	if (inode_includes(inode_size, i_checksum_hi))
  		t->i_checksum_hi = ext2fs_swab16(f->i_checksum_hi);
  	if (inode_includes(inode_size, i_ctime_extra))
  		t->i_ctime_extra = ext2fs_swab32(f->i_ctime_extra);
  	if (inode_includes(inode_size, i_mtime_extra))
  		t->i_mtime_extra = ext2fs_swab32(f->i_mtime_extra);
  	if (inode_includes(inode_size, i_atime_extra))
  		t->i_atime_extra = ext2fs_swab32(f->i_atime_extra);
  	if (inode_includes(inode_size, i_crtime))
  		t->i_crtime = ext2fs_swab32(f->i_crtime);
  	if (inode_includes(inode_size, i_crtime_extra))
  		t->i_crtime_extra = ext2fs_swab32(f->i_crtime_extra);
  	if (inode_includes(inode_size, i_version_hi))
  		t->i_version_hi = ext2fs_swab32(f->i_version_hi);
  	if (inode_includes(inode_size, i_projid))
                  t->i_projid = ext2fs_swab16(f->i_projid);
  
  	i = sizeof(struct ext2_inode) + extra_isize + sizeof(__u32);
  	if (bufsize < (int) i)
  		return; /* no space for EA magic */
  
  	eaf = (__u32 *) (((char *) f) + sizeof(struct ext2_inode) +
  					extra_isize);
  
  	attr_magic = *eaf;
  	if (!hostorder)
  		attr_magic = ext2fs_swab32(attr_magic);
  
  	if (attr_magic != EXT2_EXT_ATTR_MAGIC)
  		return; /* it seems no magic here */
  
  	eat = (__u32 *) (((char *) t) + sizeof(struct ext2_inode) +
  					extra_isize);
  	*eat = ext2fs_swab32(*eaf);
  
  	/* convert EA(s) */
  	ext2fs_swap_ext_attr((char *) (eat + 1), (char *) (eaf + 1),
  			     bufsize - sizeof(struct ext2_inode) -
  			     extra_isize - sizeof(__u32), 0);
  
  }
  
  void ext2fs_swap_inode(ext2_filsys fs, struct ext2_inode *t,
  		       struct ext2_inode *f, int hostorder)
  {
  	ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) t,
  				(struct ext2_inode_large *) f, hostorder,
  				sizeof(struct ext2_inode));
  }
  
  void ext2fs_swap_mmp(struct mmp_struct *mmp)
  {
  	mmp->mmp_magic = ext2fs_swab32(mmp->mmp_magic);
  	mmp->mmp_seq = ext2fs_swab32(mmp->mmp_seq);
  	mmp->mmp_time = ext2fs_swab64(mmp->mmp_time);
  	mmp->mmp_check_interval = ext2fs_swab16(mmp->mmp_check_interval);
  	mmp->mmp_checksum = ext2fs_swab32(mmp->mmp_checksum);
  }
  
  errcode_t ext2fs_dirent_swab_in(ext2_filsys fs, char *buf, int flags)
  {
  	return ext2fs_dirent_swab_in2(fs, buf, fs->blocksize, flags);
  }
  
  errcode_t ext2fs_dirent_swab_in2(ext2_filsys fs, char *buf,
  				 size_t size, int flags)
  {
  	errcode_t	retval;
  	char		*p, *end;
  	struct ext2_dir_entry *dirent;
  	unsigned int	name_len, rec_len;
  
  	p = (char *) buf;
  	end = (char *) buf + size;
  	while (p < end-8) {
  		dirent = (struct ext2_dir_entry *) p;
  		dirent->inode = ext2fs_swab32(dirent->inode);
  		dirent->rec_len = ext2fs_swab16(dirent->rec_len);
  		dirent->name_len = ext2fs_swab16(dirent->name_len);
  		name_len = dirent->name_len;
  		if (flags & EXT2_DIRBLOCK_V2_STRUCT)
  			dirent->name_len = ext2fs_swab16(dirent->name_len);
  		retval = ext2fs_get_rec_len(fs, dirent, &rec_len);
  		if (retval)
  			return retval;
  		if ((rec_len < 8) || (rec_len % 4)) {
  			rec_len = 8;
  			retval = EXT2_ET_DIR_CORRUPTED;
  		} else if (((name_len & 0xFF) + 8) > rec_len)
  			retval = EXT2_ET_DIR_CORRUPTED;
  		p += rec_len;
  	}
  
  	return 0;
  }
  
  errcode_t ext2fs_dirent_swab_out(ext2_filsys fs, char *buf, int flags)
  {
  	return ext2fs_dirent_swab_out2(fs, buf, fs->blocksize, flags);
  }
  
  errcode_t ext2fs_dirent_swab_out2(ext2_filsys fs, char *buf,
  				  size_t size, int flags)
  {
  	errcode_t	retval;
  	char		*p, *end;
  	unsigned int	rec_len;
  	struct ext2_dir_entry *dirent;
  
  	p = buf;
  	end = buf + size;
  	while (p < end) {
  		dirent = (struct ext2_dir_entry *) p;
  		retval = ext2fs_get_rec_len(fs, dirent, &rec_len);
  		if (retval)
  			return retval;
  		if ((rec_len < 8) ||
  		    (rec_len % 4)) {
  			ext2fs_free_mem(&buf);
  			return EXT2_ET_DIR_CORRUPTED;
  		}
  		p += rec_len;
  		dirent->inode = ext2fs_swab32(dirent->inode);
  		dirent->rec_len = ext2fs_swab16(dirent->rec_len);
  		dirent->name_len = ext2fs_swab16(dirent->name_len);
  
  		if (flags & EXT2_DIRBLOCK_V2_STRUCT)
  			dirent->name_len = ext2fs_swab16(dirent->name_len);
  	}
  
  	return 0;
  }
  
  #endif
  