xref: /xnu-10002.1.13/bsd/sys/_types/_fd_def.h (revision 1031c584a5e37aff177559b9f69dbd3c8c3fd30a)
1 /*
2  * Copyright (c) 2003-2012 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 #ifndef _FD_SET
29 #define _FD_SET
30 
31 #include <machine/types.h> /* __int32_t and uintptr_t */
32 #if !KERNEL
33 #include <Availability.h>
34 #endif
35 
36 /*
37  * Select uses bit masks of file descriptors in longs.  These macros
38  * manipulate such bit fields (the filesystem macros use chars).  The
39  * extra protection here is to permit application redefinition above
40  * the default size.
41  */
42 #ifdef FD_SETSIZE
43 #define __DARWIN_FD_SETSIZE     FD_SETSIZE
44 #else /* !FD_SETSIZE */
45 #define __DARWIN_FD_SETSIZE     1024
46 #endif /* FD_SETSIZE */
47 #define __DARWIN_NBBY           8                               /* bits in a byte */
48 #define __DARWIN_NFDBITS        (sizeof(__int32_t) * __DARWIN_NBBY) /* bits per mask */
49 #define __DARWIN_howmany(x, y)  ((((x) % (y)) == 0) ? ((x) / (y)) : (((x) / (y)) + 1)) /* # y's == x bits? */
50 
51 __BEGIN_DECLS
52 typedef struct fd_set {
53 	__int32_t       fds_bits[__DARWIN_howmany(__DARWIN_FD_SETSIZE, __DARWIN_NFDBITS)];
54 } fd_set;
55 
56 #if !KERNEL
57 int __darwin_check_fd_set_overflow(int, const void *, int) __API_AVAILABLE(macosx(10.16), ios(14.0), tvos(14.0), watchos(7.0));
58 #endif
59 __END_DECLS
60 
61 #if !KERNEL
62 __header_always_inline int
__darwin_check_fd_set(int _a,const void * _b)63 __darwin_check_fd_set(int _a, const void *_b)
64 {
65 #ifdef __clang__
66 #pragma clang diagnostic push
67 #pragma clang diagnostic ignored "-Wunguarded-availability-new"
68 #endif
69 	if ((uintptr_t)&__darwin_check_fd_set_overflow != (uintptr_t) 0) {
70 #if defined(_DARWIN_UNLIMITED_SELECT) || defined(_DARWIN_C_SOURCE)
71 		return __darwin_check_fd_set_overflow(_a, _b, 1);
72 #else
73 		return __darwin_check_fd_set_overflow(_a, _b, 0);
74 #endif
75 	} else {
76 		return 1;
77 	}
78 #ifdef __clang__
79 #pragma clang diagnostic pop
80 #endif
81 }
82 
83 /* This inline avoids argument side-effect issues with FD_ISSET() */
84 __header_always_inline int
__darwin_fd_isset(int _fd,const struct fd_set * _p)85 __darwin_fd_isset(int _fd, const struct fd_set *_p)
86 {
87 	if (__darwin_check_fd_set(_fd, (const void *) _p)) {
88 		return _p->fds_bits[(unsigned long)_fd / __DARWIN_NFDBITS] & ((__int32_t)(((unsigned long)1) << ((unsigned long)_fd % __DARWIN_NFDBITS)));
89 	}
90 
91 	return 0;
92 }
93 
94 __header_always_inline void
__darwin_fd_set(int _fd,struct fd_set * const _p)95 __darwin_fd_set(int _fd, struct fd_set *const _p)
96 {
97 	if (__darwin_check_fd_set(_fd, (const void *) _p)) {
98 		(_p->fds_bits[(unsigned long)_fd / __DARWIN_NFDBITS] |= ((__int32_t)(((unsigned long)1) << ((unsigned long)_fd % __DARWIN_NFDBITS))));
99 	}
100 }
101 
102 __header_always_inline void
__darwin_fd_clr(int _fd,struct fd_set * const _p)103 __darwin_fd_clr(int _fd, struct fd_set *const _p)
104 {
105 	if (__darwin_check_fd_set(_fd, (const void *) _p)) {
106 		(_p->fds_bits[(unsigned long)_fd / __DARWIN_NFDBITS] &= ~((__int32_t)(((unsigned long)1) << ((unsigned long)_fd % __DARWIN_NFDBITS))));
107 	}
108 }
109 
110 #else /* KERNEL */
111 
112 __header_always_inline int
113 __darwin_fd_isset(int _fd, const struct fd_set *_p)
114 {
115 	return _p->fds_bits[(unsigned long)_fd / __DARWIN_NFDBITS] & ((__int32_t)(((unsigned long)1) << ((unsigned long)_fd % __DARWIN_NFDBITS)));
116 }
117 
118 __header_always_inline void
119 __darwin_fd_set(int _fd, struct fd_set *const _p)
120 {
121 	(_p->fds_bits[(unsigned long)_fd / __DARWIN_NFDBITS] |= ((__int32_t)(((unsigned long)1) << ((unsigned long)_fd % __DARWIN_NFDBITS))));
122 }
123 
124 __header_always_inline void
125 __darwin_fd_clr(int _fd, struct fd_set *const _p)
126 {
127 	(_p->fds_bits[(unsigned long)_fd / __DARWIN_NFDBITS] &= ~((__int32_t)(((unsigned long)1) << ((unsigned long)_fd % __DARWIN_NFDBITS))));
128 }
129 #endif /* KERNEL */
130 
131 #define __DARWIN_FD_SET(n, p)   __darwin_fd_set((n), (p))
132 #define __DARWIN_FD_CLR(n, p)   __darwin_fd_clr((n), (p))
133 #define __DARWIN_FD_ISSET(n, p) __darwin_fd_isset((n), (p))
134 
135 #if __GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ >= 3
136 /*
137  * Use the built-in bzero function instead of the library version so that
138  * we do not pollute the namespace or introduce prototype warnings.
139  */
140 #define __DARWIN_FD_ZERO(p)     __builtin_bzero(p, sizeof(*(p)))
141 #else
142 #define __DARWIN_FD_ZERO(p)     bzero(p, sizeof(*(p)))
143 #endif
144 
145 #define __DARWIN_FD_COPY(f, t)  bcopy(f, t, sizeof(*(f)))
146 #endif /* _FD_SET */
147