1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1983, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __SCCSID("@(#)readdir.c 8.3 (Berkeley) 9/29/94");
34 #include "namespace.h"
35 #include <sys/param.h>
36 #include <dirent.h>
37 #include <errno.h>
38 #include <string.h>
39 #include <pthread.h>
40 #include "un-namespace.h"
41
42 #include "libc_private.h"
43 #include "gen-private.h"
44 #include "telldir.h"
45
46 /*
47 * get next entry in a directory.
48 */
49 struct dirent *
_readdir_unlocked(DIR * dirp,int flags)50 _readdir_unlocked(DIR *dirp, int flags)
51 {
52 struct dirent *dp;
53 long initial_seek;
54 long initial_loc = 0;
55
56 for (;;) {
57 if (dirp->dd_loc >= dirp->dd_size) {
58 if (dirp->dd_flags & __DTF_READALL)
59 return (NULL);
60 initial_loc = dirp->dd_loc;
61 dirp->dd_flags &= ~__DTF_SKIPREAD;
62 dirp->dd_loc = 0;
63 }
64 if (dirp->dd_loc == 0 &&
65 !(dirp->dd_flags & (__DTF_READALL | __DTF_SKIPREAD))) {
66 initial_seek = dirp->dd_seek;
67 dirp->dd_size = _getdirentries(dirp->dd_fd,
68 dirp->dd_buf, dirp->dd_len, &dirp->dd_seek);
69 if (dirp->dd_size <= 0)
70 return (NULL);
71 _fixtelldir(dirp, initial_seek, initial_loc);
72 }
73 dirp->dd_flags &= ~__DTF_SKIPREAD;
74 dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc);
75 if ((long)dp & 03L) /* bogus pointer check */
76 return (NULL);
77 if (dp->d_reclen <= 0 ||
78 dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc)
79 return (NULL);
80 dirp->dd_loc += dp->d_reclen;
81 if (dp->d_ino == 0 && (flags & RDU_SKIP) != 0)
82 continue;
83 if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW))
84 continue;
85 if (dp->d_namlen >= sizeof(dp->d_name) &&
86 (flags & RDU_SHORT) != 0)
87 continue;
88 return (dp);
89 }
90 }
91
92 struct dirent *
readdir(DIR * dirp)93 readdir(DIR *dirp)
94 {
95 struct dirent *dp;
96
97 if (__isthreaded)
98 _pthread_mutex_lock(&dirp->dd_lock);
99 dp = _readdir_unlocked(dirp, RDU_SKIP);
100 if (__isthreaded)
101 _pthread_mutex_unlock(&dirp->dd_lock);
102 return (dp);
103 }
104
105 int
__readdir_r(DIR * dirp,struct dirent * entry,struct dirent ** result)106 __readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result)
107 {
108 struct dirent *dp;
109 int saved_errno;
110
111 saved_errno = errno;
112 errno = 0;
113 if (__isthreaded)
114 _pthread_mutex_lock(&dirp->dd_lock);
115 dp = _readdir_unlocked(dirp, RDU_SKIP | RDU_SHORT);
116 if (dp != NULL)
117 memcpy(entry, dp, _GENERIC_DIRSIZ(dp));
118 if (__isthreaded)
119 _pthread_mutex_unlock(&dirp->dd_lock);
120
121 if (errno != 0) {
122 if (dp == NULL)
123 return (errno);
124 } else
125 errno = saved_errno;
126
127 if (dp != NULL)
128 *result = entry;
129 else
130 *result = NULL;
131
132 return (0);
133 }
134
135 __strong_reference(__readdir_r, readdir_r);
136