xref: /freebsd/sys/sys/select.h (revision 4928dcc0ebdb7bac56840930e44c38f8f061f09e)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef _SYS_SELECT_H_
33 #define	_SYS_SELECT_H_
34 
35 #include <sys/cdefs.h>
36 #include <sys/_types.h>
37 
38 #include <sys/_sigset.h>
39 #include <sys/_timeval.h>
40 #include <sys/timespec.h>
41 
42 typedef	unsigned long	__fd_mask;
43 #if __BSD_VISIBLE
44 typedef	__fd_mask	fd_mask;
45 #endif
46 
47 #ifndef _SIGSET_T_DECLARED
48 #define	_SIGSET_T_DECLARED
49 typedef	__sigset_t	sigset_t;
50 #endif
51 
52 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0
53 #include <ssp/ssp.h>
54 #else
55 #define	__SSP_FORTIFY_LEVEL	0
56 #endif
57 
58 /*
59  * Select uses bit masks of file descriptors in longs.  These macros
60  * manipulate such bit fields (the filesystem macros use chars).
61  * FD_SETSIZE may be defined by the user, but the default here should
62  * be enough for most uses.
63  */
64 #ifndef	FD_SETSIZE
65 #define	FD_SETSIZE	1024
66 #endif
67 
68 #define	_NFDBITS	(sizeof(__fd_mask) * 8)	/* bits per mask */
69 #if __BSD_VISIBLE
70 #define	NFDBITS		_NFDBITS
71 #endif
72 
73 #ifndef _howmany
74 #define	_howmany(x, y)	(((x) + ((y) - 1)) / (y))
75 #endif
76 
77 typedef	struct fd_set {
78 	__fd_mask	__fds_bits[_howmany(FD_SETSIZE, _NFDBITS)];
79 } fd_set;
80 #if __BSD_VISIBLE
81 #define	fds_bits	__fds_bits
82 #endif
83 
84 #define	__fdset_idx_(p, n)	((n) / _NFDBITS)
85 #if __SSP_FORTIFY_LEVEL == 0
86 #define	__fdset_idx(p, n)	__fdset_idx_(p, n)
87 #else
88 __ssp_inline unsigned long
__fdset_idx(const fd_set * p,unsigned long idx)89 __fdset_idx(const fd_set *p, unsigned long idx)
90 {
91 	__size_t psz = __ssp_bos0(p);
92 	unsigned long sidx = __fdset_idx_(p, idx);
93 
94 	if (idx >= FD_SETSIZE)
95 		__chk_fail();
96 	if (psz / sizeof(__fd_mask) < (sidx + 1))
97 		__chk_fail();
98 
99 	return (sidx);
100 }
101 #endif
102 
103 #define	__fdset_mask(n)	((__fd_mask)1 << ((n) % _NFDBITS))
104 #define	FD_CLR(n, p)	((p)->__fds_bits[__fdset_idx(p, n)] &= ~__fdset_mask(n))
105 #if __BSD_VISIBLE
106 #define	FD_COPY(f, t)	(void)(*(t) = *(f))
107 #endif
108 #define	FD_ISSET(n, p)	\
109     (((p)->__fds_bits[__fdset_idx(p, n)] & __fdset_mask(n)) != 0)
110 #define	FD_SET(n, p)	((p)->__fds_bits[__fdset_idx(p, n)] |= __fdset_mask(n))
111 #define	FD_ZERO(p) do {					\
112 	fd_set *_p;					\
113 	__size_t _n;					\
114 							\
115 	_p = (p);					\
116 	_n = _howmany(FD_SETSIZE, _NFDBITS);		\
117 	while (_n > 0)					\
118 		_p->__fds_bits[--_n] = 0;		\
119 } while (0)
120 
121 #ifndef _KERNEL
122 
123 __BEGIN_DECLS
124 int pselect(int, fd_set *__restrict, fd_set *__restrict, fd_set *__restrict,
125 	const struct timespec *__restrict, const sigset_t *__restrict);
126 #ifndef _SELECT_DECLARED
127 #define	_SELECT_DECLARED
128 /* XXX missing restrict type-qualifier */
129 int	select(int, fd_set *, fd_set *, fd_set *, struct timeval *);
130 #endif
131 __END_DECLS
132 #endif /* !_KERNEL */
133 
134 #endif /* _SYS_SELECT_H_ */
135