/src/wireshark/wsutil/bitswap.c
Line | Count | Source |
1 | | /* bitswap.c |
2 | | * Table of bit-swapped values of bytes |
3 | | * |
4 | | * Wireshark - Network traffic analyzer |
5 | | * By Gerald Combs <gerald@wireshark.org> |
6 | | * Copyright 1998 Gerald Combs |
7 | | * |
8 | | * |
9 | | * SPDX-License-Identifier: GPL-2.0-or-later |
10 | | */ |
11 | | |
12 | | #include "config.h" |
13 | | #include "bitswap.h" |
14 | | |
15 | | /* "swaptab[i]" is the value of "i" with the bits reversed. */ |
16 | | static const uint8_t swaptab[256] = |
17 | | { |
18 | | 0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0, |
19 | | 0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0, |
20 | | 0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8, |
21 | | 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8, |
22 | | 0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4, |
23 | | 0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4, |
24 | | 0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec, |
25 | | 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc, |
26 | | 0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2, |
27 | | 0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2, |
28 | | 0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea, |
29 | | 0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa, |
30 | | 0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6, |
31 | | 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6, |
32 | | 0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee, |
33 | | 0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe, |
34 | | 0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1, |
35 | | 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1, |
36 | | 0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9, |
37 | | 0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9, |
38 | | 0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5, |
39 | | 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5, |
40 | | 0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed, |
41 | | 0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd, |
42 | | 0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3, |
43 | | 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3, |
44 | | 0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb, |
45 | | 0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb, |
46 | | 0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7, |
47 | | 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7, |
48 | | 0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef, |
49 | | 0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff, |
50 | | }; |
51 | | |
52 | | void bitswap_buf_inplace(uint8_t *buf, size_t len) |
53 | 13 | { |
54 | 13 | size_t i; |
55 | | |
56 | 91 | for (i = 0; i < len; i++) |
57 | 78 | buf[i] = swaptab[buf[i]]; |
58 | 13 | } |
59 | | |
60 | | /* |
61 | | * Editor modelines - https://www.wireshark.org/tools/modelines.html |
62 | | * |
63 | | * Local Variables: |
64 | | * c-basic-offset: 2 |
65 | | * tab-width: 8 |
66 | | * indent-tabs-mode: nil |
67 | | * End: |
68 | | * |
69 | | * ex: set shiftwidth=2 tabstop=8 expandtab: |
70 | | * :indentSize=2:tabSize=8:noTabs=true: |
71 | | */ |