1/* vi: set sw=4 ts=4: */ 2/* 3 * dirblock.c --- directory block routines. 4 * 5 * Copyright (C) 1995, 1996 Theodore Ts'o. 6 * 7 * %Begin-Header% 8 * This file may be redistributed under the terms of the GNU Public 9 * License. 10 * %End-Header% 11 */ 12 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 23errcode_t ext2fs_read_dir_block2(ext2_filsys fs, blk_t block, 24 void *buf, int flags EXT2FS_ATTR((unused))) 25{ 26 errcode_t retval; 27 char *p, *end; 28 struct ext2_dir_entry *dirent; 29 unsigned int name_len, rec_len; 30#if BB_BIG_ENDIAN 31 unsigned int do_swap; 32#endif 33 34 retval = io_channel_read_blk(fs->io, block, 1, buf); 35 if (retval) 36 return retval; 37#if BB_BIG_ENDIAN 38 do_swap = (fs->flags & (EXT2_FLAG_SWAP_BYTES| 39 EXT2_FLAG_SWAP_BYTES_READ)) != 0; 40#endif 41 p = (char *) buf; 42 end = (char *) buf + fs->blocksize; 43 while (p < end-8) { 44 dirent = (struct ext2_dir_entry *) p; 45#if BB_BIG_ENDIAN 46 if (do_swap) { 47 dirent->inode = ext2fs_swab32(dirent->inode); 48 dirent->rec_len = ext2fs_swab16(dirent->rec_len); 49 dirent->name_len = ext2fs_swab16(dirent->name_len); 50 } 51#endif 52 name_len = dirent->name_len; 53#ifdef WORDS_BIGENDIAN 54 if (flags & EXT2_DIRBLOCK_V2_STRUCT) 55 dirent->name_len = ext2fs_swab16(dirent->name_len); 56#endif 57 rec_len = dirent->rec_len; 58 if ((rec_len < 8) || (rec_len % 4)) { 59 rec_len = 8; 60 retval = EXT2_ET_DIR_CORRUPTED; 61 } 62 if (((name_len & 0xFF) + 8) > dirent->rec_len) 63 retval = EXT2_ET_DIR_CORRUPTED; 64 p += rec_len; 65 } 66 return retval; 67} 68 69errcode_t ext2fs_read_dir_block(ext2_filsys fs, blk_t block, 70 void *buf) 71{ 72 return ext2fs_read_dir_block2(fs, block, buf, 0); 73} 74 75 76errcode_t ext2fs_write_dir_block2(ext2_filsys fs, blk_t block, 77 void *inbuf, int flags EXT2FS_ATTR((unused))) 78{ 79#if BB_BIG_ENDIAN 80 int do_swap = 0; 81 errcode_t retval; 82 char *p, *end; 83 char *buf = 0; 84 struct ext2_dir_entry *dirent; 85 86 if ((fs->flags & EXT2_FLAG_SWAP_BYTES) || 87 (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE)) 88 do_swap = 1; 89 90#ifndef WORDS_BIGENDIAN 91 if (!do_swap) 92 return io_channel_write_blk(fs->io, block, 1, (char *) inbuf); 93#endif 94 95 retval = ext2fs_get_mem(fs->blocksize, &buf); 96 if (retval) 97 return retval; 98 memcpy(buf, inbuf, fs->blocksize); 99 p = buf; 100 end = buf + fs->blocksize; 101 while (p < end) { 102 dirent = (struct ext2_dir_entry *) p; 103 if ((dirent->rec_len < 8) || 104 (dirent->rec_len % 4)) { 105 ext2fs_free_mem(&buf); 106 return EXT2_ET_DIR_CORRUPTED; 107 } 108 p += dirent->rec_len; 109 if (do_swap) { 110 dirent->inode = ext2fs_swab32(dirent->inode); 111 dirent->rec_len = ext2fs_swab16(dirent->rec_len); 112 dirent->name_len = ext2fs_swab16(dirent->name_len); 113 } 114#ifdef WORDS_BIGENDIAN 115 if (flags & EXT2_DIRBLOCK_V2_STRUCT) 116 dirent->name_len = ext2fs_swab16(dirent->name_len); 117#endif 118 } 119 retval = io_channel_write_blk(fs->io, block, 1, buf); 120 ext2fs_free_mem(&buf); 121 return retval; 122#else 123 return io_channel_write_blk(fs->io, block, 1, (char *) inbuf); 124#endif 125} 126 127 128errcode_t ext2fs_write_dir_block(ext2_filsys fs, blk_t block, 129 void *inbuf) 130{ 131 return ext2fs_write_dir_block2(fs, block, inbuf, 0); 132} 133