1 /* $OpenBSD: readdir.c,v 1.10 2005/08/08 08:05:34 espie Exp $ */
2 /*
3 * Copyright (c) 1983, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #include <sys/param.h>
32 #include <dirent.h>
33 #include <string.h>
34 #include <errno.h>
35 #include "thread_private.h"
36
37 /*
38 * get next entry in a directory.
39 */
40 struct dirent *
readdir(DIR * dirp)41 readdir(DIR *dirp)
42 {
43 struct dirent *dp;
44
45 for (;;) {
46 if (dirp->dd_loc >= dirp->dd_size) {
47 if (dirp->dd_flags & __DTF_READALL)
48 return (NULL);
49 dirp->dd_loc = 0;
50 }
51 if (dirp->dd_loc == 0 && !(dirp->dd_flags & __DTF_READALL)) {
52 dirp->dd_size = getdirentries(dirp->dd_fd,
53 dirp->dd_buf, dirp->dd_len, &dirp->dd_seek);
54 if (dirp->dd_size <= 0)
55 return (NULL);
56 }
57 dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc);
58 if ((long)dp & 03) /* bogus pointer check */
59 return (NULL);
60 if (dp->d_reclen <= 0 ||
61 dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc)
62 return (NULL);
63 dirp->dd_loc += dp->d_reclen;
64 if (dp->d_ino == 0)
65 continue;
66 return (dp);
67 }
68 }
69
70 int
readdir_r(DIR * dirp,struct dirent * entry,struct dirent ** result)71 readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result)
72 {
73 struct dirent *dp;
74 int ret;
75
76 if (dirp->dd_fd < 0) {
77 return EBADF;
78 }
79 if ((ret = _FD_LOCK(dirp->dd_fd, FD_READ, NULL)) != 0)
80 return ret;
81 errno = 0;
82 dp = readdir(dirp);
83 if (dp == NULL && errno != 0) {
84 _FD_UNLOCK(dirp->dd_fd, FD_READ);
85 return errno;
86 }
87 if (dp != NULL)
88 memcpy(entry, dp, sizeof (struct dirent) - MAXNAMLEN + dp->d_namlen);
89 _FD_UNLOCK(dirp->dd_fd, FD_READ);
90 if (dp != NULL)
91 *result = entry;
92 else
93 *result = NULL;
94 return 0;
95 }
96