Merge from vendor branch BZIP:
[dragonfly.git] / lib / libc / gen / opendir.c
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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. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * $FreeBSD: src/lib/libc/gen/opendir.c,v 1.10.2.1 2001/06/04 20:59:48 joerg Exp $
0f52d283 34 * $DragonFly: src/lib/libc/gen/opendir.c,v 1.6 2005/11/13 00:07:42 swildner Exp $
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35 *
36 * @(#)opendir.c 8.8 (Berkeley) 5/1/95
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37 */
38
17ea2221 39#include "namespace.h"
984263bc 40#include <sys/param.h>
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41#include <sys/stat.h>
42
43#include <dirent.h>
44#include <errno.h>
45#include <fcntl.h>
46#include <stdlib.h>
4cb07007 47#include <string.h>
984263bc 48#include <unistd.h>
17ea2221 49#include "un-namespace.h"
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50
51/*
52 * Open a directory.
53 */
54DIR *
4cb07007 55opendir(const char *name)
984263bc 56{
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57 return (__opendir2(name, DTF_HIDEW|DTF_NODUP));
58}
59
60DIR *
4cb07007 61__opendir2(const char *name, int flags)
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62{
63 DIR *dirp;
64 int fd;
65 int incr;
66 int saved_errno;
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67 struct stat statb;
68
69 /*
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70 * stat() before _open() because opening of special files may be
71 * harmful. _fstat() after open because the file may have changed.
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72 */
73 if (stat(name, &statb) != 0)
74 return (NULL);
75 if (!S_ISDIR(statb.st_mode)) {
76 errno = ENOTDIR;
77 return (NULL);
78 }
79 if ((fd = _open(name, O_RDONLY | O_NONBLOCK)) == -1)
80 return (NULL);
81 dirp = NULL;
17ea2221 82 if (_fstat(fd, &statb) != 0)
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83 goto fail;
84 if (!S_ISDIR(statb.st_mode)) {
85 errno = ENOTDIR;
86 goto fail;
87 }
88 if (_fcntl(fd, F_SETFD, FD_CLOEXEC) == -1 ||
89 (dirp = malloc(sizeof(DIR))) == NULL)
90 goto fail;
91
92 /*
93 * Use the system page size if that is a multiple of DIRBLKSIZ.
94 * Hopefully this can be a big win someday by allowing page
17ea2221 95 * trades to user space to be done by _getdirentries().
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96 */
97 incr = getpagesize();
98 if ((incr % DIRBLKSIZ) != 0)
99 incr = DIRBLKSIZ;
100
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101 dirp->dd_len = incr;
102 dirp->dd_buf = malloc(dirp->dd_len);
103 if (dirp->dd_buf == NULL)
104 goto fail;
105 dirp->dd_seek = 0;
106 flags &= ~DTF_REWIND;
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107
108 dirp->dd_loc = 0;
109 dirp->dd_fd = fd;
110 dirp->dd_flags = flags;
17ea2221 111 dirp->dd_lock = NULL;
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112
113 /*
114 * Set up seek point for rewinddir.
115 */
116 dirp->dd_rewind = telldir(dirp);
117
118 return (dirp);
119
120fail:
121 saved_errno = errno;
122 free(dirp);
0f52d283 123 _close(fd);
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124 errno = saved_errno;
125 return (NULL);
126}