xref: /freebsd/lib/libc/stdio/fclose.c (revision a2f733abcff64628b7771a47089628b7327a88bd)
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 #include "namespace.h"
37 #include <errno.h>
38 #include <stdbool.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include "un-namespace.h"
42 #include <spinlock.h>
43 #include "libc_private.h"
44 #include "local.h"
45 
46 static int
47 cleanfile(FILE *fp, bool c)
48 {
49 	int r;
50 
51 	r = fp->_flags & __SWR ? __sflush(fp) : 0;
52 	if (c) {
53 		if (fp->_close != NULL && (*fp->_close)(fp->_cookie) < 0)
54 			r = EOF;
55 	}
56 
57 	if (fp->_flags & __SMBF)
58 		free((char *)fp->_bf._base);
59 	if (HASUB(fp))
60 		FREEUB(fp);
61 	if (HASLB(fp))
62 		FREELB(fp);
63 	fp->_file = -1;
64 	fp->_r = fp->_w = 0;	/* Mess up if reaccessed. */
65 
66 	/*
67 	 * Lock the spinlock used to protect __sglue list walk in
68 	 * __sfp().  The __sfp() uses fp->_flags == 0 test as an
69 	 * indication of the unused FILE.
70 	 *
71 	 * Taking the lock prevents possible compiler or processor
72 	 * reordering of the writes performed before the final _flags
73 	 * cleanup, making sure that we are done with the FILE before
74 	 * it is considered available.
75 	 */
76 	STDIO_THREAD_LOCK();
77 	fp->_flags = 0;		/* Release this FILE for reuse. */
78 	STDIO_THREAD_UNLOCK();
79 
80 	return (r);
81 }
82 
83 int
84 fdclose(FILE *fp, int *fdp)
85 {
86 	int r, err;
87 
88 	if (fdp != NULL)
89 		*fdp = -1;
90 
91 	if (fp->_flags == 0) {	/* not open! */
92 		errno = EBADF;
93 		return (EOF);
94 	}
95 
96 	FLOCKFILE_CANCELSAFE(fp);
97 	r = 0;
98 	if (fp->_close != __sclose) {
99 		r = EOF;
100 		errno = EOPNOTSUPP;
101 	} else if (fp->_file < 0) {
102 		r = EOF;
103 		errno = EBADF;
104 	}
105 	if (r == EOF) {
106 		err = errno;
107 		(void)cleanfile(fp, true);
108 		errno = err;
109 	} else {
110 		if (fdp != NULL)
111 			*fdp = fp->_file;
112 		r = cleanfile(fp, false);
113 	}
114 	FUNLOCKFILE_CANCELSAFE();
115 
116 	return (r);
117 }
118 
119 int
120 fclose(FILE *fp)
121 {
122 	int r;
123 
124 	if (fp->_flags == 0) {	/* not open! */
125 		errno = EBADF;
126 		return (EOF);
127 	}
128 
129 	FLOCKFILE_CANCELSAFE(fp);
130 	r = cleanfile(fp, true);
131 	FUNLOCKFILE_CANCELSAFE();
132 
133 	return (r);
134 }
135