1*89a51591SEric Biggers // SPDX-License-Identifier: GPL-2.0-only 2*89a51591SEric Biggers /* 3*89a51591SEric Biggers * crc-itu-t.c 4*89a51591SEric Biggers */ 5*89a51591SEric Biggers 6*89a51591SEric Biggers #include <linux/types.h> 7*89a51591SEric Biggers #include <linux/module.h> 8*89a51591SEric Biggers #include <linux/crc-itu-t.h> 9*89a51591SEric Biggers 10*89a51591SEric Biggers /* CRC table for the CRC ITU-T V.41 0x1021 (x^16 + x^12 + x^5 + 1) */ 11*89a51591SEric Biggers const u16 crc_itu_t_table[256] = { 12*89a51591SEric Biggers 0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7, 13*89a51591SEric Biggers 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef, 14*89a51591SEric Biggers 0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6, 15*89a51591SEric Biggers 0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de, 16*89a51591SEric Biggers 0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485, 17*89a51591SEric Biggers 0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d, 18*89a51591SEric Biggers 0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4, 19*89a51591SEric Biggers 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc, 20*89a51591SEric Biggers 0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823, 21*89a51591SEric Biggers 0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b, 22*89a51591SEric Biggers 0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12, 23*89a51591SEric Biggers 0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a, 24*89a51591SEric Biggers 0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41, 25*89a51591SEric Biggers 0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49, 26*89a51591SEric Biggers 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70, 27*89a51591SEric Biggers 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78, 28*89a51591SEric Biggers 0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f, 29*89a51591SEric Biggers 0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067, 30*89a51591SEric Biggers 0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e, 31*89a51591SEric Biggers 0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256, 32*89a51591SEric Biggers 0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d, 33*89a51591SEric Biggers 0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405, 34*89a51591SEric Biggers 0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c, 35*89a51591SEric Biggers 0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634, 36*89a51591SEric Biggers 0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab, 37*89a51591SEric Biggers 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3, 38*89a51591SEric Biggers 0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a, 39*89a51591SEric Biggers 0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92, 40*89a51591SEric Biggers 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9, 41*89a51591SEric Biggers 0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1, 42*89a51591SEric Biggers 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8, 43*89a51591SEric Biggers 0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0 44*89a51591SEric Biggers }; 45*89a51591SEric Biggers 46*89a51591SEric Biggers EXPORT_SYMBOL(crc_itu_t_table); 47*89a51591SEric Biggers 48*89a51591SEric Biggers /** 49*89a51591SEric Biggers * crc_itu_t - Compute the CRC-ITU-T for the data buffer 50*89a51591SEric Biggers * 51*89a51591SEric Biggers * @crc: previous CRC value 52*89a51591SEric Biggers * @buffer: data pointer 53*89a51591SEric Biggers * @len: number of bytes in the buffer 54*89a51591SEric Biggers * 55*89a51591SEric Biggers * Returns the updated CRC value 56*89a51591SEric Biggers */ 57*89a51591SEric Biggers u16 crc_itu_t(u16 crc, const u8 *buffer, size_t len) 58*89a51591SEric Biggers { 59*89a51591SEric Biggers while (len--) 60*89a51591SEric Biggers crc = crc_itu_t_byte(crc, *buffer++); 61*89a51591SEric Biggers return crc; 62*89a51591SEric Biggers } 63*89a51591SEric Biggers EXPORT_SYMBOL(crc_itu_t); 64*89a51591SEric Biggers 65*89a51591SEric Biggers MODULE_DESCRIPTION("CRC ITU-T V.41 calculations"); 66*89a51591SEric Biggers MODULE_LICENSE("GPL"); 67*89a51591SEric Biggers 68