dir_iterate.c revision 9f8046fc6dfc13eee2f5c363214e60b533872cac 
1/*
2 * dir_iterate.c --- ext2fs directory iteration operations
3 *
4 * Copyright (C) 1993, 1994, 1994, 1995, 1996, 1997 Theodore Ts'o.
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the GNU Public
8 * License.
9 * %End-Header%
10 */
11
12#include <stdio.h>
13#include <string.h>
14#if HAVE_UNISTD_H
15#include <unistd.h>
16#endif
17#if HAVE_ERRNO_H
18#include <errno.h>
19#endif
20
21#include "ext2_fs.h"
22#include "ext2fsP.h"
23
24errcode_t ext2fs_dir_iterate(ext2_filsys fs,
25			     ext2_ino_t dir,
26			     int flags,
27			     char *block_buf,
28			     int (*func)(struct ext2_dir_entry *dirent,
29					 int	offset,
30					 int	blocksize,
31					 char	*buf,
32					 void	*priv_data),
33			     void *priv_data)
34{
35	struct		dir_context	ctx;
36	errcode_t	retval;
37
38	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
39
40	retval = ext2fs_check_directory(fs, dir);
41	if (retval)
42		return retval;
43
44	ctx.dir = dir;
45	ctx.flags = flags;
46	if (block_buf)
47		ctx.buf = block_buf;
48	else {
49		retval = ext2fs_get_mem(fs->blocksize, (void **) &ctx.buf);
50		if (retval)
51			return retval;
52	}
53	ctx.func = func;
54	ctx.func2 = 0;
55	ctx.priv_data = priv_data;
56	ctx.errcode = 0;
57	retval = ext2fs_block_iterate2(fs, dir, 0, 0,
58				       ext2fs_process_dir_block, &ctx);
59	if (!block_buf)
60		ext2fs_free_mem((void **) &ctx.buf);
61	if (retval)
62		return retval;
63	return ctx.errcode;
64}
65
66/*
67 * Helper function which is private to this module.  Used by
68 * ext2fs_dir_iterate() and ext2fs_dblist_dir_iterate()
69 */
70int ext2fs_process_dir_block(ext2_filsys  	fs,
71			     blk_t		*blocknr,
72			     e2_blkcnt_t		blockcnt,
73			     blk_t		ref_block,
74			     int			ref_offset,
75			     void		*priv_data)
76{
77	struct dir_context *ctx = (struct dir_context *) priv_data;
78	int		offset = 0;
79	int		ret = 0;
80	int		changed = 0;
81	int		do_abort = 0;
82	int		entry;
83	struct ext2_dir_entry *dirent;
84
85	if (blockcnt < 0)
86		return 0;
87
88	entry = blockcnt ? DIRENT_OTHER_FILE : DIRENT_DOT_FILE;
89
90	ctx->errcode = ext2fs_read_dir_block(fs, *blocknr, ctx->buf);
91	if (ctx->errcode)
92		return BLOCK_ABORT;
93
94	while (offset < fs->blocksize) {
95		dirent = (struct ext2_dir_entry *) (ctx->buf + offset);
96		if (((offset + dirent->rec_len) > fs->blocksize) ||
97		    (dirent->rec_len < 8) ||
98		    ((dirent->rec_len % 4) != 0) ||
99		    (((dirent->name_len & 0xFF)+8) > dirent->rec_len)) {
100			ctx->errcode = EXT2_ET_DIR_CORRUPTED;
101			return BLOCK_ABORT;
102		}
103		if (!dirent->inode &&
104		    !(ctx->flags & DIRENT_FLAG_INCLUDE_EMPTY))
105			goto next;
106
107		if (ctx->func)
108			ret = (ctx->func)(dirent, offset, fs->blocksize,
109					  ctx->buf, ctx->priv_data);
110		else if (ctx->func2) {
111			ret = (ctx->func2)(ctx->dir, entry, dirent, offset,
112					   fs->blocksize, ctx->buf,
113					   ctx->priv_data);
114			if (entry < DIRENT_OTHER_FILE)
115				entry++;
116		}
117
118		if (ret & DIRENT_CHANGED)
119			changed++;
120		if (ret & DIRENT_ABORT) {
121			do_abort++;
122			break;
123		}
124next:
125		offset += dirent->rec_len;
126	}
127
128	if (changed) {
129		ctx->errcode = ext2fs_write_dir_block(fs, *blocknr, ctx->buf);
130		if (ctx->errcode)
131			return BLOCK_ABORT;
132	}
133	if (do_abort)
134		return BLOCK_ABORT;
135	return 0;
136}
137
138