xref: /freebsd/contrib/openbsm/compat/endian.h (revision 06e8e46410776c1d2a28c89004cda266402a8e69)
1 /*-
2  * Copyright (c) 2002 Thomas Moestl <tmm@FreeBSD.org>
3  * Copyright (c) 2005 Robert N. M. Watson
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * Derived from FreeBSD src/sys/sys/endian.h:1.6.
28  * $P4: //depot/projects/trustedbsd/openbsm/compat/endian.h#10 $
29  */
30 
31 #ifndef _COMPAT_ENDIAN_H_
32 #define _COMPAT_ENDIAN_H_
33 
34 /*
35  * Some systems will have the uint/int types defined here already, others
36  * will need stdint.h.
37  */
38 #ifdef HAVE_STDINT_H
39 #include <stdint.h>
40 #endif
41 
42 /*
43  * Some operating systems do not yet have the more recent endian APIs that
44  * permit encoding to and decoding from byte streams.  For those systems, we
45  * implement local non-optimized versions.
46  */
47 
48 static __inline uint16_t
49 bswap16(uint16_t int16)
50 {
51 	const unsigned char *from;
52 	unsigned char *to;
53 	uint16_t t;
54 
55 	from = (const unsigned char *) &int16;
56 	to = (unsigned char *) &t;
57 
58 	to[0] = from[1];
59 	to[1] = from[0];
60 
61 	return (t);
62 }
63 
64 static __inline uint32_t
65 bswap32(uint32_t int32)
66 {
67 	const unsigned char *from;
68 	unsigned char *to;
69 	uint32_t t;
70 
71 	from = (const unsigned char *) &int32;
72 	to = (unsigned char *) &t;
73 
74 	to[0] = from[3];
75 	to[1] = from[2];
76 	to[2] = from[1];
77 	to[3] = from[0];
78 
79 	return (t);
80 }
81 
82 static __inline uint64_t
83 bswap64(uint64_t int64)
84 {
85 	const unsigned char *from;
86 	unsigned char *to;
87 	uint64_t t;
88 
89 	from = (const unsigned char *) &int64;
90 	to = (unsigned char *) &t;
91 
92 	to[0] = from[7];
93 	to[1] = from[6];
94 	to[2] = from[5];
95 	to[3] = from[4];
96 	to[4] = from[3];
97 	to[5] = from[2];
98 	to[6] = from[1];
99 	to[7] = from[0];
100 
101 	return (t);
102 }
103 
104 #if defined(BYTE_ORDER) && !defined(_BYTE_ORDER)
105 #define	_BYTE_ORDER	BYTE_ORDER
106 #endif
107 #if !defined(_BYTE_ORDER)
108 #error "Neither BYTE_ORDER nor _BYTE_ORDER defined"
109 #endif
110 
111 #if defined(BIG_ENDIAN) && !defined(_BIG_ENDIAN)
112 #define	_BIG_ENDIAN	BIG_ENDIAN
113 #endif
114 
115 #if defined(LITTLE_ENDIAN) && !defined(_LITTLE_ENDIAN)
116 #define	_LITTLE_ENDIAN	LITTLE_ENDIAN
117 #endif
118 
119 /* XXX: Hack. */
120 #ifndef htobe16
121 /*
122  * Host to big endian, host to little endian, big endian to host, and little
123  * endian to host byte order functions as detailed in byteorder(9).
124  */
125 #if _BYTE_ORDER == _LITTLE_ENDIAN
126 #define	htobe16(x)	bswap16((x))
127 #define	htobe32(x)	bswap32((x))
128 #define	htobe64(x)	bswap64((x))
129 #define	htole16(x)	((uint16_t)(x))
130 #define	htole32(x)	((uint32_t)(x))
131 #define	htole64(x)	((uint64_t)(x))
132 
133 #define	be16toh(x)	bswap16((x))
134 #define	be32toh(x)	bswap32((x))
135 #define	be64toh(x)	bswap64((x))
136 #define	le16toh(x)	((uint16_t)(x))
137 #define	le32toh(x)	((uint32_t)(x))
138 #define	le64toh(x)	((uint64_t)(x))
139 #else /* _BYTE_ORDER != _LITTLE_ENDIAN */
140 #define	htobe16(x)	((uint16_t)(x))
141 #define	htobe32(x)	((uint32_t)(x))
142 #define	htobe64(x)	((uint64_t)(x))
143 #define	htole16(x)	bswap16((x))
144 #define	htole32(x)	bswap32((x))
145 #define	htole64(x)	bswap64((x))
146 
147 #define	be16toh(x)	((uint16_t)(x))
148 #define	be32toh(x)	((uint32_t)(x))
149 #define	be64toh(x)	((uint64_t)(x))
150 #define	le16toh(x)	bswap16((x))
151 #define	le32toh(x)	bswap32((x))
152 #define	le64toh(x)	bswap64((x))
153 #endif /* _BYTE_ORDER == _LITTLE_ENDIAN */
154 #endif
155 
156 #endif	/* _COMPAT_ENDIAN_H_ */
157