/src/wireshark/wsutil/crc6.c
Line | Count | Source |
1 | | /* |
2 | | * crc6.c |
3 | | * |
4 | | * Wireshark - Network traffic analyzer |
5 | | * By Gerald Combs <gerald@wireshark.org> |
6 | | * Copyright 1998 Gerald Combs |
7 | | * |
8 | | * SPDX-License-Identifier: GPL-2.0-or-later |
9 | | */ |
10 | | |
11 | | /* |
12 | | Patch by Ross Jacobs <rossbjacobs@gmail.com>: |
13 | | Fixed CRC6 0x6F lookup table + function per Wireshark bug 14875 |
14 | | */ |
15 | | |
16 | | #include "config.h" |
17 | | |
18 | | #include "crc6.h" |
19 | | |
20 | | /** |
21 | | * Functions and types for CRC checks. |
22 | | * |
23 | | * Generated on Wed Jan 2 2019, |
24 | | * by pycrc v0.9.1, http://www.tty1.net/pycrc/ |
25 | | * using the configuration: |
26 | | * Width = 6 |
27 | | * Poly = 0x6f |
28 | | * XorIn = 0 |
29 | | * ReflectIn = False |
30 | | * XorOut = 0 |
31 | | * ReflectOut = False |
32 | | */ |
33 | | static const uint8_t crc6_table[256] = { |
34 | | 0x00, 0x2f, 0x31, 0x1e, 0x0d, 0x22, 0x3c, 0x13, 0x1a, 0x35, 0x2b, 0x04, 0x17, 0x38, 0x26, 0x09, |
35 | | 0x34, 0x1b, 0x05, 0x2a, 0x39, 0x16, 0x08, 0x27, 0x2e, 0x01, 0x1f, 0x30, 0x23, 0x0c, 0x12, 0x3d, |
36 | | 0x07, 0x28, 0x36, 0x19, 0x0a, 0x25, 0x3b, 0x14, 0x1d, 0x32, 0x2c, 0x03, 0x10, 0x3f, 0x21, 0x0e, |
37 | | 0x33, 0x1c, 0x02, 0x2d, 0x3e, 0x11, 0x0f, 0x20, 0x29, 0x06, 0x18, 0x37, 0x24, 0x0b, 0x15, 0x3a, |
38 | | 0x0e, 0x21, 0x3f, 0x10, 0x03, 0x2c, 0x32, 0x1d, 0x14, 0x3b, 0x25, 0x0a, 0x19, 0x36, 0x28, 0x07, |
39 | | 0x3a, 0x15, 0x0b, 0x24, 0x37, 0x18, 0x06, 0x29, 0x20, 0x0f, 0x11, 0x3e, 0x2d, 0x02, 0x1c, 0x33, |
40 | | 0x09, 0x26, 0x38, 0x17, 0x04, 0x2b, 0x35, 0x1a, 0x13, 0x3c, 0x22, 0x0d, 0x1e, 0x31, 0x2f, 0x00, |
41 | | 0x3d, 0x12, 0x0c, 0x23, 0x30, 0x1f, 0x01, 0x2e, 0x27, 0x08, 0x16, 0x39, 0x2a, 0x05, 0x1b, 0x34, |
42 | | 0x1c, 0x33, 0x2d, 0x02, 0x11, 0x3e, 0x20, 0x0f, 0x06, 0x29, 0x37, 0x18, 0x0b, 0x24, 0x3a, 0x15, |
43 | | 0x28, 0x07, 0x19, 0x36, 0x25, 0x0a, 0x14, 0x3b, 0x32, 0x1d, 0x03, 0x2c, 0x3f, 0x10, 0x0e, 0x21, |
44 | | 0x1b, 0x34, 0x2a, 0x05, 0x16, 0x39, 0x27, 0x08, 0x01, 0x2e, 0x30, 0x1f, 0x0c, 0x23, 0x3d, 0x12, |
45 | | 0x2f, 0x00, 0x1e, 0x31, 0x22, 0x0d, 0x13, 0x3c, 0x35, 0x1a, 0x04, 0x2b, 0x38, 0x17, 0x09, 0x26, |
46 | | 0x12, 0x3d, 0x23, 0x0c, 0x1f, 0x30, 0x2e, 0x01, 0x08, 0x27, 0x39, 0x16, 0x05, 0x2a, 0x34, 0x1b, |
47 | | 0x26, 0x09, 0x17, 0x38, 0x2b, 0x04, 0x1a, 0x35, 0x3c, 0x13, 0x0d, 0x22, 0x31, 0x1e, 0x00, 0x2f, |
48 | | 0x15, 0x3a, 0x24, 0x0b, 0x18, 0x37, 0x29, 0x06, 0x0f, 0x20, 0x3e, 0x11, 0x02, 0x2d, 0x33, 0x1c, |
49 | | 0x21, 0x0e, 0x10, 0x3f, 0x2c, 0x03, 0x1d, 0x32, 0x3b, 0x14, 0x0a, 0x25, 0x36, 0x19, 0x07, 0x28 |
50 | | }; |
51 | | |
52 | | /** |
53 | | * CRC6 is used by 3GPP (TS 25.415, TS 25.446) for header CRCs |
54 | | * Poly: D^6 + D^5 + D^3 + D^2 + D^1 + 1 |
55 | | * |
56 | | * TS 25.415 docs: https://www.etsi.org/deliver/etsi_ts/125400_125499/125415/04.06.00_60/ts_125415v040600p.pdf |
57 | | * TS 25.446 docs: https://www.etsi.org/deliver/etsi_ts/125400_125499/125446/10.01.00_60/ts_125446v100100p.pdf |
58 | | */ |
59 | | uint16_t crc6_0X6F(uint16_t crc, const uint8_t *data, int data_len) |
60 | 0 | { |
61 | 0 | uint8_t tbl_idx; |
62 | |
|
63 | 0 | while (data_len--) { |
64 | 0 | tbl_idx = (crc << 2) ^ *data; |
65 | 0 | crc = crc6_table[tbl_idx] & 0x3f; |
66 | 0 | data++; |
67 | 0 | } |
68 | 0 | return crc & 0x3f; |
69 | 0 | } |
70 | | |
71 | | /* |
72 | | * Editor modelines - https://www.wireshark.org/tools/modelines.html |
73 | | * |
74 | | * Local variables: |
75 | | * c-basic-offset: 4 |
76 | | * tab-width: 8 |
77 | | * indent-tabs-mode: nil |
78 | | * End: |
79 | | * |
80 | | * vi: set shiftwidth=4 tabstop=8 expandtab: |
81 | | * :indentSize=4:tabSize=8:noTabs=true: |
82 | | */ |