/* vi: set sw=4 ts=4: *//* * dir_iterate.c --- ext2fs directory iteration operations * * Copyright (C) 1993, 1994, 1994, 1995, 1996, 1997 Theodore Ts'o. * * %Begin-Header% * This file may be redistributed under the terms of the GNU Public * License. * %End-Header% */#include <stdio.h>#include <string.h>#if HAVE_UNISTD_H#include <unistd.h>#endif#if HAVE_ERRNO_H#include <errno.h>#endif#include "ext2_fs.h"#include "ext2fsP.h"/* * This function checks to see whether or not a potential deleted * directory entry looks valid.  What we do is check the deleted entry * and each successive entry to make sure that they all look valid and * that the last deleted entry ends at the beginning of the next * undeleted entry.  Returns 1 if the deleted entry looks valid, zero * if not valid. */static int ext2fs_validate_entry(char *buf, int offset, int final_offset){	struct ext2_dir_entry *dirent;	while (offset < final_offset) {		dirent = (struct ext2_dir_entry *)(buf + offset);		offset += dirent->rec_len;		if ((dirent->rec_len < 8) ||		    ((dirent->rec_len % 4) != 0) ||		    (((dirent->name_len & 0xFF)+8) > dirent->rec_len))			return 0;	}	return (offset == final_offset);}errcode_t ext2fs_dir_iterate2(ext2_filsys fs,			      ext2_ino_t dir,			      int flags,			      char *block_buf,			      int (*func)(ext2_ino_t	dir,					  int		entry,					  struct ext2_dir_entry *dirent,					  int	offset,					  int	blocksize,					  char	*buf,					  void	*priv_data),			      void *priv_data){	struct		dir_context	ctx;	errcode_t	retval;	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);	retval = ext2fs_check_directory(fs, dir);	if (retval)		return retval;	ctx.dir = dir;	ctx.flags = flags;	if (block_buf)		ctx.buf = block_buf;	else {		retval = ext2fs_get_mem(fs->blocksize, &ctx.buf);		if (retval)			return retval;	}	ctx.func = func;	ctx.priv_data = priv_data;	ctx.errcode = 0;	retval = ext2fs_block_iterate2(fs, dir, 0, 0,				       ext2fs_process_dir_block, &ctx);	if (!block_buf)		ext2fs_free_mem(&ctx.buf);	if (retval)		return retval;	return ctx.errcode;}struct xlate {	int (*func)(struct ext2_dir_entry *dirent,		    int		offset,		    int		blocksize,		    char	*buf,		    void	*priv_data);	void *real_private;};static int xlate_func(ext2_ino_t dir EXT2FS_ATTR((unused)),		      int entry EXT2FS_ATTR((unused)),		      struct ext2_dir_entry *dirent, int offset,		      int blocksize, char *buf, void *priv_data){	struct xlate *xl = (struct xlate *) priv_data;	return (*xl->func)(dirent, offset, blocksize, buf, xl->real_private);}extern errcode_t ext2fs_dir_iterate(ext2_filsys fs,			      ext2_ino_t dir,			      int flags,			      char *block_buf,			      int (*func)(struct ext2_dir_entry *dirent,					  int	offset,					  int	blocksize,					  char	*buf,					  void	*priv_data),			      void *priv_data){	struct xlate xl;	xl.real_private = priv_data;	xl.func = func;	return ext2fs_dir_iterate2(fs, dir, flags, block_buf,				   xlate_func, &xl);}/* * Helper function which is private to this module.  Used by * ext2fs_dir_iterate() and ext2fs_dblist_dir_iterate() */int ext2fs_process_dir_block(ext2_filsys fs,			     blk_t	*blocknr,			     e2_blkcnt_t blockcnt,			     blk_t	ref_block EXT2FS_ATTR((unused)),			     int	ref_offset EXT2FS_ATTR((unused)),			     void	*priv_data){	struct dir_context *ctx = (struct dir_context *) priv_data;	unsigned int	offset = 0;	unsigned int	next_real_entry = 0;	int		ret = 0;	int		changed = 0;	int		do_abort = 0;	int		entry, size;	struct ext2_dir_entry *dirent;	if (blockcnt < 0)		return 0;	entry = blockcnt ? DIRENT_OTHER_FILE : DIRENT_DOT_FILE;	ctx->errcode = ext2fs_read_dir_block(fs, *blocknr, ctx->buf);	if (ctx->errcode)		return BLOCK_ABORT;	while (offset < fs->blocksize) {		dirent = (struct ext2_dir_entry *) (ctx->buf + offset);		if (((offset + dirent->rec_len) > fs->blocksize) ||		    (dirent->rec_len < 8) ||		    ((dirent->rec_len % 4) != 0) ||		    (((dirent->name_len & 0xFF)+8) > dirent->rec_len)) {			ctx->errcode = EXT2_ET_DIR_CORRUPTED;			return BLOCK_ABORT;		}		if (!dirent->inode &&		    !(ctx->flags & DIRENT_FLAG_INCLUDE_EMPTY))			goto next;		ret = (ctx->func)(ctx->dir,				  (next_real_entry > offset) ?				  DIRENT_DELETED_FILE : entry,				  dirent, offset,				  fs->blocksize, ctx->buf,				  ctx->priv_data);		if (entry < DIRENT_OTHER_FILE)			entry++;		if (ret & DIRENT_CHANGED)			changed++;		if (ret & DIRENT_ABORT) {			do_abort++;			break;		}next:		if (next_real_entry == offset)			next_real_entry += dirent->rec_len;		if (ctx->flags & DIRENT_FLAG_INCLUDE_REMOVED) {			size = ((dirent->name_len & 0xFF) + 11) & ~3;			if (dirent->rec_len != size)  {				unsigned int final_offset;				final_offset = offset + dirent->rec_len;				offset += size;				while (offset < final_offset &&				       !ext2fs_validate_entry(ctx->buf,							      offset,							      final_offset))					offset += 4;				continue;			}		}		offset += dirent->rec_len;	}	if (changed) {		ctx->errcode = ext2fs_write_dir_block(fs, *blocknr, ctx->buf);		if (ctx->errcode)			return BLOCK_ABORT;	}	if (do_abort)		return BLOCK_ABORT;	return 0;}