xref: /freebsd/lib/libc/stdio/fclose.c (revision d68cc5a8390f5316400181b77a195f734567abd3)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1990, 1993 The Regents of the University of California.
5  * Copyright (c) 2013 Mariusz Zaborski <oshogbo@FreeBSD.org>
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Chris Torek.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #if defined(LIBC_SCCS) && !defined(lint)
37 static char sccsid[] = "@(#)fclose.c	8.1 (Berkeley) 6/4/93";
38 #endif /* LIBC_SCCS and not lint */
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 #include "namespace.h"
43 #include <errno.h>
44 #include <stdbool.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include "un-namespace.h"
48 #include <spinlock.h>
49 #include "libc_private.h"
50 #include "local.h"
51 
52 static int
53 cleanfile(FILE *fp, bool c)
54 {
55 	int r;
56 
57 	r = fp->_flags & __SWR ? __sflush(fp) : 0;
58 	if (c) {
59 		if (fp->_close != NULL && (*fp->_close)(fp->_cookie) < 0)
60 			r = EOF;
61 	}
62 
63 	if (fp->_flags & __SMBF)
64 		free((char *)fp->_bf._base);
65 	if (HASUB(fp))
66 		FREEUB(fp);
67 	if (HASLB(fp))
68 		FREELB(fp);
69 	fp->_file = -1;
70 	fp->_r = fp->_w = 0;	/* Mess up if reaccessed. */
71 
72 	/*
73 	 * Lock the spinlock used to protect __sglue list walk in
74 	 * __sfp().  The __sfp() uses fp->_flags == 0 test as an
75 	 * indication of the unused FILE.
76 	 *
77 	 * Taking the lock prevents possible compiler or processor
78 	 * reordering of the writes performed before the final _flags
79 	 * cleanup, making sure that we are done with the FILE before
80 	 * it is considered available.
81 	 */
82 	STDIO_THREAD_LOCK();
83 	fp->_flags = 0;		/* Release this FILE for reuse. */
84 	STDIO_THREAD_UNLOCK();
85 
86 	return (r);
87 }
88 
89 int
90 fdclose(FILE *fp, int *fdp)
91 {
92 	int r, err;
93 
94 	if (fdp != NULL)
95 		*fdp = -1;
96 
97 	if (fp->_flags == 0) {	/* not open! */
98 		errno = EBADF;
99 		return (EOF);
100 	}
101 
102 	FLOCKFILE_CANCELSAFE(fp);
103 	r = 0;
104 	if (fp->_close != __sclose) {
105 		r = EOF;
106 		errno = EOPNOTSUPP;
107 	} else if (fp->_file < 0) {
108 		r = EOF;
109 		errno = EBADF;
110 	}
111 	if (r == EOF) {
112 		err = errno;
113 		(void)cleanfile(fp, true);
114 		errno = err;
115 	} else {
116 		if (fdp != NULL)
117 			*fdp = fp->_file;
118 		r = cleanfile(fp, false);
119 	}
120 	FUNLOCKFILE_CANCELSAFE();
121 
122 	return (r);
123 }
124 
125 int
126 fclose(FILE *fp)
127 {
128 	int r;
129 
130 	if (fp->_flags == 0) {	/* not open! */
131 		errno = EBADF;
132 		return (EOF);
133 	}
134 
135 	FLOCKFILE_CANCELSAFE(fp);
136 	r = cleanfile(fp, true);
137 	FUNLOCKFILE_CANCELSAFE();
138 
139 	return (r);
140 }
141