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 __FBSDID("$FreeBSD$");
35
36 #include "namespace.h"
37 #include <sys/param.h>
38 #include <dirent.h>
39 #include <errno.h>
40 #include <string.h>
41 #include <pthread.h>
42 #include "un-namespace.h"
43
44 #include "libc_private.h"
45 #include "gen-private.h"
46 #include "telldir.h"
47
48 /*
49 * get next entry in a directory.
50 */
51 struct dirent *
_readdir_unlocked(DIR * dirp,int flags)52 _readdir_unlocked(DIR *dirp, int flags)
53 {
54 struct dirent *dp;
55 long initial_seek;
56 long initial_loc = 0;
57
58 for (;;) {
59 if (dirp->dd_loc >= dirp->dd_size) {
60 if (dirp->dd_flags & __DTF_READALL)
61 return (NULL);
62 initial_loc = dirp->dd_loc;
63 dirp->dd_flags &= ~__DTF_SKIPREAD;
64 dirp->dd_loc = 0;
65 }
66 if (dirp->dd_loc == 0 &&
67 !(dirp->dd_flags & (__DTF_READALL | __DTF_SKIPREAD))) {
68 initial_seek = dirp->dd_seek;
69 dirp->dd_size = _getdirentries(dirp->dd_fd,
70 dirp->dd_buf, dirp->dd_len, &dirp->dd_seek);
71 if (dirp->dd_size <= 0)
72 return (NULL);
73 _fixtelldir(dirp, initial_seek, initial_loc);
74 }
75 dirp->dd_flags &= ~__DTF_SKIPREAD;
76 dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc);
77 if ((long)dp & 03L) /* bogus pointer check */
78 return (NULL);
79 if (dp->d_reclen <= 0 ||
80 dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc)
81 return (NULL);
82 dirp->dd_loc += dp->d_reclen;
83 if (dp->d_ino == 0 && (flags & RDU_SKIP) != 0)
84 continue;
85 if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW))
86 continue;
87 if (dp->d_namlen >= sizeof(dp->d_name) &&
88 (flags & RDU_SHORT) != 0)
89 continue;
90 return (dp);
91 }
92 }
93
94 struct dirent *
readdir(DIR * dirp)95 readdir(DIR *dirp)
96 {
97 struct dirent *dp;
98
99 if (__isthreaded)
100 _pthread_mutex_lock(&dirp->dd_lock);
101 dp = _readdir_unlocked(dirp, RDU_SKIP);
102 if (__isthreaded)
103 _pthread_mutex_unlock(&dirp->dd_lock);
104 return (dp);
105 }
106
107 int
__readdir_r(DIR * dirp,struct dirent * entry,struct dirent ** result)108 __readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result)
109 {
110 struct dirent *dp;
111 int saved_errno;
112
113 saved_errno = errno;
114 errno = 0;
115 if (__isthreaded)
116 _pthread_mutex_lock(&dirp->dd_lock);
117 dp = _readdir_unlocked(dirp, RDU_SKIP | RDU_SHORT);
118 if (dp != NULL)
119 memcpy(entry, dp, _GENERIC_DIRSIZ(dp));
120 if (__isthreaded)
121 _pthread_mutex_unlock(&dirp->dd_lock);
122
123 if (errno != 0) {
124 if (dp == NULL)
125 return (errno);
126 } else
127 errno = saved_errno;
128
129 if (dp != NULL)
130 *result = entry;
131 else
132 *result = NULL;
133
134 return (0);
135 }
136
137 __strong_reference(__readdir_r, readdir_r);
138