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Diffstat (limited to '')
| -rw-r--r-- | wsutil/crc6.c | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/wsutil/crc6.c b/wsutil/crc6.c new file mode 100644 index 0000000..f55df00 --- /dev/null +++ b/wsutil/crc6.c @@ -0,0 +1,82 @@ +/* + * crc6.c + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +/* + Patch by Ross Jacobs <rossbjacobs@gmail.com>: + Fixed CRC6 0x6F lookup table + function per Wireshark bug 14875 +*/ + +#include "config.h" + +#include "crc6.h" + +/** + * Functions and types for CRC checks. + * + * Generated on Wed Jan 2 2019, + * by pycrc v0.9.1, http://www.tty1.net/pycrc/ + * using the configuration: + * Width = 6 + * Poly = 0x6f + * XorIn = 0 + * ReflectIn = False + * XorOut = 0 + * ReflectOut = False + */ +static const uint8_t crc6_table[256] = { + 0x00, 0x2f, 0x31, 0x1e, 0x0d, 0x22, 0x3c, 0x13, 0x1a, 0x35, 0x2b, 0x04, 0x17, 0x38, 0x26, 0x09, + 0x34, 0x1b, 0x05, 0x2a, 0x39, 0x16, 0x08, 0x27, 0x2e, 0x01, 0x1f, 0x30, 0x23, 0x0c, 0x12, 0x3d, + 0x07, 0x28, 0x36, 0x19, 0x0a, 0x25, 0x3b, 0x14, 0x1d, 0x32, 0x2c, 0x03, 0x10, 0x3f, 0x21, 0x0e, + 0x33, 0x1c, 0x02, 0x2d, 0x3e, 0x11, 0x0f, 0x20, 0x29, 0x06, 0x18, 0x37, 0x24, 0x0b, 0x15, 0x3a, + 0x0e, 0x21, 0x3f, 0x10, 0x03, 0x2c, 0x32, 0x1d, 0x14, 0x3b, 0x25, 0x0a, 0x19, 0x36, 0x28, 0x07, + 0x3a, 0x15, 0x0b, 0x24, 0x37, 0x18, 0x06, 0x29, 0x20, 0x0f, 0x11, 0x3e, 0x2d, 0x02, 0x1c, 0x33, + 0x09, 0x26, 0x38, 0x17, 0x04, 0x2b, 0x35, 0x1a, 0x13, 0x3c, 0x22, 0x0d, 0x1e, 0x31, 0x2f, 0x00, + 0x3d, 0x12, 0x0c, 0x23, 0x30, 0x1f, 0x01, 0x2e, 0x27, 0x08, 0x16, 0x39, 0x2a, 0x05, 0x1b, 0x34, + 0x1c, 0x33, 0x2d, 0x02, 0x11, 0x3e, 0x20, 0x0f, 0x06, 0x29, 0x37, 0x18, 0x0b, 0x24, 0x3a, 0x15, + 0x28, 0x07, 0x19, 0x36, 0x25, 0x0a, 0x14, 0x3b, 0x32, 0x1d, 0x03, 0x2c, 0x3f, 0x10, 0x0e, 0x21, + 0x1b, 0x34, 0x2a, 0x05, 0x16, 0x39, 0x27, 0x08, 0x01, 0x2e, 0x30, 0x1f, 0x0c, 0x23, 0x3d, 0x12, + 0x2f, 0x00, 0x1e, 0x31, 0x22, 0x0d, 0x13, 0x3c, 0x35, 0x1a, 0x04, 0x2b, 0x38, 0x17, 0x09, 0x26, + 0x12, 0x3d, 0x23, 0x0c, 0x1f, 0x30, 0x2e, 0x01, 0x08, 0x27, 0x39, 0x16, 0x05, 0x2a, 0x34, 0x1b, + 0x26, 0x09, 0x17, 0x38, 0x2b, 0x04, 0x1a, 0x35, 0x3c, 0x13, 0x0d, 0x22, 0x31, 0x1e, 0x00, 0x2f, + 0x15, 0x3a, 0x24, 0x0b, 0x18, 0x37, 0x29, 0x06, 0x0f, 0x20, 0x3e, 0x11, 0x02, 0x2d, 0x33, 0x1c, + 0x21, 0x0e, 0x10, 0x3f, 0x2c, 0x03, 0x1d, 0x32, 0x3b, 0x14, 0x0a, 0x25, 0x36, 0x19, 0x07, 0x28 +}; + +/** + * CRC6 is used by 3GPP (TS 25.415, TS 25.446) for header CRCs + * Poly: D^6 + D^5 + D^3 + D^2 + D^1 + 1 + * + * TS 25.415 docs: https://www.etsi.org/deliver/etsi_ts/125400_125499/125415/04.06.00_60/ts_125415v040600p.pdf + * TS 25.446 docs: https://www.etsi.org/deliver/etsi_ts/125400_125499/125446/10.01.00_60/ts_125446v100100p.pdf +*/ +uint16_t crc6_0X6F(uint16_t crc, const uint8_t *data, int data_len) +{ + uint8_t tbl_idx; + + while (data_len--) { + tbl_idx = (crc << 2) ^ *data; + crc = crc6_table[tbl_idx] & 0x3f; + data++; + } + return crc & 0x3f; +} + +/* + * Editor modelines - https://www.wireshark.org/tools/modelines.html + * + * Local variables: + * c-basic-offset: 4 + * tab-width: 8 + * indent-tabs-mode: nil + * End: + * + * vi: set shiftwidth=4 tabstop=8 expandtab: + * :indentSize=4:tabSize=8:noTabs=true: + */ |