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 * 4. 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
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)readdir.c 8.3 (Berkeley) 9/29/94";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
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 skip)52 _readdir_unlocked(DIR *dirp, int skip)
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 && skip)
84 continue;
85 if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW))
86 continue;
87 return (dp);
88 }
89 }
90
91 struct dirent *
readdir(DIR * dirp)92 readdir(DIR *dirp)
93 {
94 struct dirent *dp;
95
96 if (__isthreaded) {
97 _pthread_mutex_lock(&dirp->dd_lock);
98 dp = _readdir_unlocked(dirp, 1);
99 _pthread_mutex_unlock(&dirp->dd_lock);
100 }
101 else
102 dp = _readdir_unlocked(dirp, 1);
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 if ((dp = _readdir_unlocked(dirp, 1)) != NULL)
117 memcpy(entry, dp, _GENERIC_DIRSIZ(dp));
118 _pthread_mutex_unlock(&dirp->dd_lock);
119 }
120 else if ((dp = _readdir_unlocked(dirp, 1)) != NULL)
121 memcpy(entry, dp, _GENERIC_DIRSIZ(dp));
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