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 "namespace.h"
33 #include <sys/param.h>
34 #include <dirent.h>
35 #include <errno.h>
36 #include <string.h>
37 #include <pthread.h>
38 #include "un-namespace.h"
39
40 #include "libc_private.h"
41 #include "gen-private.h"
42 #include "telldir.h"
43
44 /*
45 * get next entry in a directory.
46 */
47 struct dirent *
_readdir_unlocked(DIR * dirp,int flags)48 _readdir_unlocked(DIR *dirp, int flags)
49 {
50 struct dirent *dp;
51 off_t initial_seek;
52 size_t initial_loc = 0;
53 ssize_t ret;
54
55 for (;;) {
56 if (dirp->dd_loc >= dirp->dd_size) {
57 if (dirp->dd_flags & __DTF_READALL)
58 return (NULL);
59 initial_loc = dirp->dd_loc;
60 dirp->dd_flags &= ~__DTF_SKIPREAD;
61 dirp->dd_loc = 0;
62 }
63 if (dirp->dd_loc == 0 &&
64 !(dirp->dd_flags & (__DTF_READALL | __DTF_SKIPREAD))) {
65 dirp->dd_size = 0;
66 initial_seek = dirp->dd_seek;
67 ret = _getdirentries(dirp->dd_fd,
68 dirp->dd_buf, dirp->dd_len, &dirp->dd_seek);
69 if (ret <= 0)
70 return (NULL);
71 dirp->dd_size = (size_t)ret;
72 _fixtelldir(dirp, initial_seek, initial_loc);
73 }
74 dirp->dd_flags &= ~__DTF_SKIPREAD;
75 dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc);
76 if ((long)dp & 03L) /* bogus pointer check */
77 return (NULL);
78 if (dp->d_reclen <= 0 ||
79 dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc)
80 return (NULL);
81 dirp->dd_loc += dp->d_reclen;
82 if (dp->d_ino == 0 && (flags & RDU_SKIP) != 0)
83 continue;
84 if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW))
85 continue;
86 if (dp->d_namlen >= sizeof(dp->d_name) &&
87 (flags & RDU_SHORT) != 0)
88 continue;
89 return (dp);
90 }
91 }
92
93 struct dirent *
readdir(DIR * dirp)94 readdir(DIR *dirp)
95 {
96 struct dirent *dp;
97
98 if (__isthreaded)
99 _pthread_mutex_lock(&dirp->dd_lock);
100 dp = _readdir_unlocked(dirp, RDU_SKIP);
101 if (__isthreaded)
102 _pthread_mutex_unlock(&dirp->dd_lock);
103 return (dp);
104 }
105
106 int
__readdir_r(DIR * dirp,struct dirent * entry,struct dirent ** result)107 __readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result)
108 {
109 struct dirent *dp;
110 int saved_errno;
111
112 saved_errno = errno;
113 errno = 0;
114 if (__isthreaded)
115 _pthread_mutex_lock(&dirp->dd_lock);
116 dp = _readdir_unlocked(dirp, RDU_SKIP | RDU_SHORT);
117 if (dp != NULL)
118 memcpy(entry, dp, _GENERIC_DIRSIZ(dp));
119 if (__isthreaded)
120 _pthread_mutex_unlock(&dirp->dd_lock);
121
122 if (errno != 0) {
123 if (dp == NULL)
124 return (errno);
125 } else
126 errno = saved_errno;
127
128 if (dp != NULL)
129 *result = entry;
130 else
131 *result = NULL;
132
133 return (0);
134 }
135
136 __strong_reference(__readdir_r, readdir_r);
137 __warn_references(readdir_r,
138 "warning: this program uses readdir_r(), which is unsafe.");
139