134 lines
3.1 KiB
C
134 lines
3.1 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* dirblock.c --- directory block routines.
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*
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* Copyright (C) 1995, 1996 Theodore Ts'o.
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*
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* %Begin-Header%
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* This file may be redistributed under the terms of the GNU Public
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* License.
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* %End-Header%
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*/
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#include <stdio.h>
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#if HAVE_UNISTD_H
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#include <unistd.h>
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#endif
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#include <string.h>
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#include <time.h>
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#include "ext2_fs.h"
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#include "ext2fs.h"
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errcode_t ext2fs_read_dir_block2(ext2_filsys fs, blk_t block,
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void *buf, int flags EXT2FS_ATTR((unused)))
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{
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errcode_t retval;
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char *p, *end;
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struct ext2_dir_entry *dirent;
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unsigned int name_len, rec_len;
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#if BB_BIG_ENDIAN
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unsigned int do_swap;
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#endif
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retval = io_channel_read_blk(fs->io, block, 1, buf);
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if (retval)
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return retval;
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#if BB_BIG_ENDIAN
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do_swap = (fs->flags & (EXT2_FLAG_SWAP_BYTES|
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EXT2_FLAG_SWAP_BYTES_READ)) != 0;
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#endif
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p = (char *) buf;
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end = (char *) buf + fs->blocksize;
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while (p < end-8) {
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dirent = (struct ext2_dir_entry *) p;
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#if BB_BIG_ENDIAN
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if (do_swap) {
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dirent->inode = ext2fs_swab32(dirent->inode);
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dirent->rec_len = ext2fs_swab16(dirent->rec_len);
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dirent->name_len = ext2fs_swab16(dirent->name_len);
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}
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#endif
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name_len = dirent->name_len;
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#ifdef WORDS_BIGENDIAN
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if (flags & EXT2_DIRBLOCK_V2_STRUCT)
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dirent->name_len = ext2fs_swab16(dirent->name_len);
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#endif
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rec_len = dirent->rec_len;
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if ((rec_len < 8) || (rec_len % 4)) {
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rec_len = 8;
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retval = EXT2_ET_DIR_CORRUPTED;
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}
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if (((name_len & 0xFF) + 8) > dirent->rec_len)
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retval = EXT2_ET_DIR_CORRUPTED;
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p += rec_len;
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}
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return retval;
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}
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errcode_t ext2fs_read_dir_block(ext2_filsys fs, blk_t block,
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void *buf)
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{
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return ext2fs_read_dir_block2(fs, block, buf, 0);
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}
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errcode_t ext2fs_write_dir_block2(ext2_filsys fs, blk_t block,
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void *inbuf, int flags EXT2FS_ATTR((unused)))
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{
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#if BB_BIG_ENDIAN
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int do_swap = 0;
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errcode_t retval;
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char *p, *end;
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char *buf = 0;
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struct ext2_dir_entry *dirent;
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if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
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(fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE))
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do_swap = 1;
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#ifndef WORDS_BIGENDIAN
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if (!do_swap)
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return io_channel_write_blk(fs->io, block, 1, (char *) inbuf);
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#endif
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retval = ext2fs_get_mem(fs->blocksize, &buf);
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if (retval)
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return retval;
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memcpy(buf, inbuf, fs->blocksize);
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p = buf;
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end = buf + fs->blocksize;
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while (p < end) {
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dirent = (struct ext2_dir_entry *) p;
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if ((dirent->rec_len < 8) ||
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(dirent->rec_len % 4)) {
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ext2fs_free_mem(&buf);
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return EXT2_ET_DIR_CORRUPTED;
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}
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p += dirent->rec_len;
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if (do_swap) {
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dirent->inode = ext2fs_swab32(dirent->inode);
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dirent->rec_len = ext2fs_swab16(dirent->rec_len);
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dirent->name_len = ext2fs_swab16(dirent->name_len);
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}
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#ifdef WORDS_BIGENDIAN
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if (flags & EXT2_DIRBLOCK_V2_STRUCT)
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dirent->name_len = ext2fs_swab16(dirent->name_len);
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#endif
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}
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retval = io_channel_write_blk(fs->io, block, 1, buf);
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ext2fs_free_mem(&buf);
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return retval;
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#else
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return io_channel_write_blk(fs->io, block, 1, (char *) inbuf);
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#endif
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}
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errcode_t ext2fs_write_dir_block(ext2_filsys fs, blk_t block,
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void *inbuf)
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{
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return ext2fs_write_dir_block2(fs, block, inbuf, 0);
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}
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