1 // SPDX-License-Identifier: GPL-2.0-only 1
2 /*
3 * linux/lib/crc-ccitt.c
4 */
5
6 #include <linux/types.h>
7 #include <linux/module.h>
8 #include <linux/crc-ccitt.h>
9
10 /*
11 * This mysterious table is just the CRC of ea
12 * computed using the standard bit-at-a-time m
13 * be seen in entry 128, 0x8408. This correspo
14 * Add the implicit x^16, and you have the sta
15 */
16 u16 const crc_ccitt_table[256] = {
17 0x0000, 0x1189, 0x2312, 0x329b, 0x4624
18 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c
19 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5
20 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed
21 0x2102, 0x308b, 0x0210, 0x1399, 0x6726
22 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e
23 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7
24 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef
25 0x4204, 0x538d, 0x6116, 0x709f, 0x0420
26 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868
27 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1
28 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9
29 0x6306, 0x728f, 0x4014, 0x519d, 0x2522
30 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a
31 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3
32 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb
33 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c
34 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64
35 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad
36 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5
37 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e
38 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66
39 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af
40 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7
41 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028
42 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60
43 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9
44 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1
45 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a
46 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62
47 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab
48 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3
49 };
50 EXPORT_SYMBOL(crc_ccitt_table);
51
52 /**
53 * crc_ccitt - recompute the CRC (CRC-CCI
54 * buffer
55 * @crc: previous CRC value
56 * @buffer: data pointer
57 * @len: number of bytes in the buffer
58 */
59 u16 crc_ccitt(u16 crc, u8 const *buffer, size_
60 {
61 while (len--)
62 crc = crc_ccitt_byte(crc, *buf
63 return crc;
64 }
65 EXPORT_SYMBOL(crc_ccitt);
66
67 MODULE_DESCRIPTION("CRC-CCITT calculations");
68 MODULE_LICENSE("GPL");
69
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.