1 /*
2 * Copyright (c) 1983, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $FreeBSD: src/lib/libc/gen/readdir.c,v 1.5.2.4 2002/02/26 22:53:57 alfred Exp $
30 *
31 * @(#)readdir.c 8.3 (Berkeley) 9/29/94
32 */
33
34 #include "namespace.h"
35 #include <sys/param.h>
36 #include <sys/file.h>
37 #include <dirent.h>
38 #include <errno.h>
39 #include <string.h>
40 #include <pthread.h>
41 #include <unistd.h>
42 #include "un-namespace.h"
43
44 #include "libc_private.h"
45 #include "gen_private.h"
46
47 /*
48 * get next entry in a directory.
49 */
50 struct dirent *
_readdir_unlocked(DIR * dirp,int skipdeleted)51 _readdir_unlocked(DIR *dirp, int skipdeleted)
52 {
53 struct dirent *dp;
54 long dummy;
55
56 for (;;) {
57 if (dirp->dd_loc >= dirp->dd_size) {
58 if (dirp->dd_flags & __DTF_READALL)
59 return (NULL);
60 dirp->dd_loc = 0;
61 }
62 if (dirp->dd_loc == 0 && !(dirp->dd_flags & __DTF_READALL)) {
63 dirp->dd_seek = lseek(dirp->dd_fd, 0, SEEK_CUR);
64 dirp->dd_size = _getdirentries(dirp->dd_fd,
65 dirp->dd_buf, dirp->dd_len, &dummy);
66 if (dirp->dd_size <= 0)
67 return (NULL);
68 }
69 dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc);
70 if (_DIRENT_DIRSIZ(dp) > dirp->dd_len + 1 - dirp->dd_loc)
71 return (NULL);
72 dirp->dd_loc += _DIRENT_DIRSIZ(dp);
73
74 if (skipdeleted) {
75 if (dp->d_ino == 0)
76 continue;
77 if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW))
78 continue;
79 }
80 return (dp);
81 }
82 }
83
84 struct dirent *
readdir(DIR * dirp)85 readdir(DIR *dirp)
86 {
87 struct dirent *dp;
88
89 if (__isthreaded)
90 _pthread_mutex_lock(&dirp->dd_lock);
91 dp = _readdir_unlocked(dirp, 1);
92 if (__isthreaded)
93 _pthread_mutex_unlock(&dirp->dd_lock);
94
95 return (dp);
96 }
97
98 int
readdir_r(DIR * __restrict dirp,struct dirent * __restrict entry,struct dirent ** __restrict result)99 readdir_r(DIR * __restrict dirp, struct dirent * __restrict entry,
100 struct dirent ** __restrict result)
101 {
102 struct dirent *dp;
103 int saved_errno;
104
105 saved_errno = errno;
106 errno = 0;
107 if (__isthreaded)
108 _pthread_mutex_lock(&dirp->dd_lock);
109 if ((dp = _readdir_unlocked(dirp, 1)) != NULL)
110 memcpy(entry, dp, _DIRENT_MINSIZ(dp));
111 if (__isthreaded)
112 _pthread_mutex_unlock(&dirp->dd_lock);
113
114 if (errno != 0) {
115 if (dp == NULL) {
116 return (errno);
117 }
118 } else
119 errno = saved_errno;
120
121 if (dp != NULL)
122 *result = entry;
123 else
124 *result = NULL;
125
126 return (0);
127 }
128