1: /*
2: * Simple byteorder handling.
3: *
4: * Copyright (C) 1992-1995 Andrew Tridgell
5: * Copyright (C) 2007-2020 Wayne Davison
6: *
7: * This program is free software; you can redistribute it and/or modify
8: * it under the terms of the GNU General Public License as published by
9: * the Free Software Foundation; either version 3 of the License, or
10: * (at your option) any later version.
11: *
12: * This program is distributed in the hope that it will be useful,
13: * but WITHOUT ANY WARRANTY; without even the implied warranty of
14: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15: * GNU General Public License for more details.
16: *
17: * You should have received a copy of the GNU General Public License along
18: * with this program; if not, visit the http://fsf.org website.
19: */
20:
21: #undef CAREFUL_ALIGNMENT
22:
23: /* We know that the x86 can handle misalignment and has the same
24: * byte order (LSB-first) as the 32-bit numbers we transmit. */
25: #if defined __i386__ || defined __i486__ || defined __i586__ || defined __i686__ || __amd64
26: #define CAREFUL_ALIGNMENT 0
27: #endif
28:
29: #ifndef CAREFUL_ALIGNMENT
30: #define CAREFUL_ALIGNMENT 1
31: #endif
32:
33: #define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
34: #define UVAL(buf,pos) ((uint32)CVAL(buf,pos))
35:
36: #if CAREFUL_ALIGNMENT
37:
38: static inline uint32
39: IVALu(const uchar *buf, int pos)
40: {
41: return UVAL(buf, pos)
42: | UVAL(buf, pos + 1) << 8
43: | UVAL(buf, pos + 2) << 16
44: | UVAL(buf, pos + 3) << 24;
45: }
46:
47: static inline void
48: SIVALu(uchar *buf, int pos, uint32 val)
49: {
50: CVAL(buf, pos) = val;
51: CVAL(buf, pos + 1) = val >> 8;
52: CVAL(buf, pos + 2) = val >> 16;
53: CVAL(buf, pos + 3) = val >> 24;
54: }
55:
56: static inline int64
57: IVAL64(const char *buf, int pos)
58: {
59: return IVALu((uchar*)buf, pos) | (int64)IVALu((uchar*)buf, pos + 4) << 32;
60: }
61:
62: static inline void
63: SIVAL64(char *buf, int pos, int64 val)
64: {
65: SIVALu((uchar*)buf, pos, val);
66: SIVALu((uchar*)buf, pos + 4, val >> 32);
67: }
68:
69: #else /* !CAREFUL_ALIGNMENT */
70:
71: /* This handles things for architectures like the 386 that can handle alignment errors.
72: * WARNING: This section is dependent on the length of an int32 (and thus a uint32)
73: * being correct (4 bytes)! Set CAREFUL_ALIGNMENT if it is not. */
74:
75: static inline uint32
76: IVALu(const uchar *buf, int pos)
77: {
78: union {
79: const uchar *b;
80: const uint32 *num;
81: } u;
82: u.b = buf + pos;
83: return *u.num;
84: }
85:
86: static inline void
87: SIVALu(uchar *buf, int pos, uint32 val)
88: {
89: union {
90: uchar *b;
91: uint32 *num;
92: } u;
93: u.b = buf + pos;
94: *u.num = val;
95: }
96:
97: static inline int64
98: IVAL64(const char *buf, int pos)
99: {
100: union {
101: const char *b;
102: const int64 *num;
103: } u;
104: u.b = buf + pos;
105: return *u.num;
106: }
107:
108: static inline void
109: SIVAL64(char *buf, int pos, int64 val)
110: {
111: union {
112: char *b;
113: int64 *num;
114: } u;
115: u.b = buf + pos;
116: *u.num = val;
117: }
118:
119: #endif /* !CAREFUL_ALIGNMENT */
120:
121: static inline uint32
122: IVAL(const char *buf, int pos)
123: {
124: return IVALu((uchar*)buf, pos);
125: }
126:
127: static inline void
128: SIVAL(char *buf, int pos, uint32 val)
129: {
130: SIVALu((uchar*)buf, pos, val);
131: }
132:
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