xref: /freebsd/lib/libc/stdio/fclose.c (revision 5f4c09dd85bff675e0ca63c55ea3c517e0fddfcc)
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 "namespace.h"
40 #include <errno.h>
41 #include <stdbool.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include "un-namespace.h"
45 #include <spinlock.h>
46 #include "libc_private.h"
47 #include "local.h"
48 
49 static int
50 cleanfile(FILE *fp, bool c)
51 {
52 	int r;
53 
54 	r = fp->_flags & __SWR ? __sflush(fp) : 0;
55 	if (c) {
56 		if (fp->_close != NULL && (*fp->_close)(fp->_cookie) < 0)
57 			r = EOF;
58 	}
59 
60 	if (fp->_flags & __SMBF)
61 		free((char *)fp->_bf._base);
62 	if (HASUB(fp))
63 		FREEUB(fp);
64 	if (HASLB(fp))
65 		FREELB(fp);
66 	fp->_file = -1;
67 	fp->_r = fp->_w = 0;	/* Mess up if reaccessed. */
68 
69 	/*
70 	 * Lock the spinlock used to protect __sglue list walk in
71 	 * __sfp().  The __sfp() uses fp->_flags == 0 test as an
72 	 * indication of the unused FILE.
73 	 *
74 	 * Taking the lock prevents possible compiler or processor
75 	 * reordering of the writes performed before the final _flags
76 	 * cleanup, making sure that we are done with the FILE before
77 	 * it is considered available.
78 	 */
79 	STDIO_THREAD_LOCK();
80 	fp->_flags = 0;		/* Release this FILE for reuse. */
81 	STDIO_THREAD_UNLOCK();
82 
83 	return (r);
84 }
85 
86 int
87 fdclose(FILE *fp, int *fdp)
88 {
89 	int r, err;
90 
91 	if (fdp != NULL)
92 		*fdp = -1;
93 
94 	if (fp->_flags == 0) {	/* not open! */
95 		errno = EBADF;
96 		return (EOF);
97 	}
98 
99 	FLOCKFILE_CANCELSAFE(fp);
100 	r = 0;
101 	if (fp->_close != __sclose) {
102 		r = EOF;
103 		errno = EOPNOTSUPP;
104 	} else if (fp->_file < 0) {
105 		r = EOF;
106 		errno = EBADF;
107 	}
108 	if (r == EOF) {
109 		err = errno;
110 		(void)cleanfile(fp, true);
111 		errno = err;
112 	} else {
113 		if (fdp != NULL)
114 			*fdp = fp->_file;
115 		r = cleanfile(fp, false);
116 	}
117 	FUNLOCKFILE_CANCELSAFE();
118 
119 	return (r);
120 }
121 
122 int
123 fclose(FILE *fp)
124 {
125 	int r;
126 
127 	if (fp->_flags == 0) {	/* not open! */
128 		errno = EBADF;
129 		return (EOF);
130 	}
131 
132 	FLOCKFILE_CANCELSAFE(fp);
133 	r = cleanfile(fp, true);
134 	FUNLOCKFILE_CANCELSAFE();
135 
136 	return (r);
137 }
138