--- libelwix/src/crc.c 2013/07/18 14:55:42 1.1.1.1.22.1 +++ libelwix/src/crc.c 2024/10/10 23:53:00 1.6.36.1 @@ -3,7 +3,7 @@ * by Michael Pounov * * $Author: misho $ -* $Id: crc.c,v 1.1.1.1.22.1 2013/07/18 14:55:42 misho Exp $ +* $Id: crc.c,v 1.6.36.1 2024/10/10 23:53:00 misho Exp $ * ************************************************************************** The ELWIX and AITNET software is distributed under the following @@ -12,7 +12,7 @@ terms: All of the documentation and software included in the ELWIX and AITNET Releases is copyrighted by ELWIX - Sofia/Bulgaria -Copyright 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 +Copyright 2004 - 2024 by Michael Pounov . All rights reserved. Redistribution and use in source and binary forms, with or without @@ -46,6 +46,9 @@ SUCH DAMAGE. #include "global.h" +/* CRC16 poly */ +const u_short crc_16poly = 0x1021; + /* Adler module */ const u_int crc_modAdler = 0xFFF1L; @@ -64,7 +67,9 @@ const crcPoly_t crc_Poly[] = { { 16, (u_int) 0x8005, "CRC-16-IBM" }, { 24, (u_int) 0x864CFB, "CRC-24-Radix64" }, { 30, (u_int) 0x2030B9C7, "CRC-30-CDMA" }, - { 32, (u_int) 0x04C11DB7, "CRC-32-802.3" } + { 32, (u_int) 0x04C11DB7, "CRC-32-802.3" }, + { 16, (u_int) 0x1021, "CRC-16-CCITT" }, + { 16, (u_int) 0x8408, "CRC-16-XMODEM" } }; @@ -73,9 +78,9 @@ const crcPoly_t crc_Poly[] = { * * @crcNum = Number for reflection * @crcBits = Number width bits - * return: -1 error, !=-1 reflecting number + * return: reflecting number */ -inline u_int +u_int crcReflect(u_int crcNum, u_char crcBits) { register u_int i, j = 1, rev = 0; @@ -95,12 +100,12 @@ crcReflect(u_int crcNum, u_char crcBits) * @RevOpts = Options for computation (REVOPTS_REVERTBYTE, REVOPTS_REVERTCRC) * @initCRC = Initial CRC value * @xorCRC = Last xor CRC value - * return: -1 error, !=-1 CRC checksum + * return: CRC checksum */ -inline u_int +u_int crcCalc(u_char * __restrict psBuf, u_int bufLen, u_char crcBits, u_char RevOpts, u_int initCRC, u_int xorCRC) { - const u_int bits = sizeof(int) * 8 - crcBits; + u_int bits = sizeof(int) * 8; u_int poly, crchibit, crc; register u_int i, j, b, ch; @@ -109,46 +114,70 @@ crcCalc(u_char * __restrict psBuf, u_int bufLen, u_cha switch (crcBits) { case 1: poly = crc_Poly[0].poly_num; + bits -= crc_Poly[0].poly_bits; break; case 4: poly = crc_Poly[1].poly_num; + bits -= crc_Poly[1].poly_bits; break; case 5: poly = crc_Poly[2].poly_num; + bits -= crc_Poly[2].poly_bits; break; case 6: poly = crc_Poly[3].poly_num; + bits -= crc_Poly[3].poly_bits; break; case 7: poly = crc_Poly[4].poly_num; + bits -= crc_Poly[4].poly_bits; break; case 8: poly = crc_Poly[5].poly_num; + bits -= crc_Poly[5].poly_bits; break; case 10: poly = crc_Poly[6].poly_num; + bits -= crc_Poly[6].poly_bits; break; case 11: poly = crc_Poly[7].poly_num; + bits -= crc_Poly[7].poly_bits; break; case 12: poly = crc_Poly[8].poly_num; + bits -= crc_Poly[8].poly_bits; break; case 15: poly = crc_Poly[9].poly_num; + bits -= crc_Poly[9].poly_bits; break; case 16: poly = crc_Poly[10].poly_num; + bits -= crc_Poly[10].poly_bits; break; case 24: poly = crc_Poly[11].poly_num; + bits -= crc_Poly[11].poly_bits; break; case 30: poly = crc_Poly[12].poly_num; + bits -= crc_Poly[12].poly_bits; break; case 32: poly = crc_Poly[13].poly_num; + bits -= crc_Poly[13].poly_bits; break; + case 161: + poly = crc_Poly[14].poly_num; + bits -= crc_Poly[14].poly_bits; + crcBits = crc_Poly[14].poly_bits; + break; + case 162: + poly = crc_Poly[15].poly_num; + bits -= crc_Poly[15].poly_bits; + crcBits = crc_Poly[15].poly_bits; + break; default: elwix_SetErr(EINVAL, "crcCalc(): Unsupported CRC method!!!"); return -1; @@ -187,13 +216,75 @@ crcCalc(u_char * __restrict psBuf, u_int bufLen, u_cha /* + * crc16_xy() - Checksum calculation in X/Y modem communication + * + * @buf = Data for calculation + * @bufLen = Length of data + * return: Checksum + */ +u_short +crc16_xy(u_char * __restrict buf, int bufLen) +{ + u_short crc, x; + register u_short i; + + assert(buf); + + for (crc = 0; bufLen > 0; bufLen--, buf++) + for (i = 0x80; i; i >>= 1) { + x = crc >> 15; + crc <<= 1; + + if (*buf & i) + crc++; + if (x) + crc ^= crc_16poly; + } + + for (i = 0; i < 16; i++) { + x = crc >> 15; + crc <<= 1; + + if (x) + crc ^= crc_16poly; + } + + return crc; +} + +/* + * crc16_ccitt() - Checksum calculation + * + * @buf = Data for calculation + * @bufLen = Length of data + * return: Checksum + */ +u_short +crc16_ccitt(u_char * __restrict buf, int bufLen) +{ + u_short crc; + register u_char i; + + for (crc = 0; bufLen > 0; bufLen--, buf++) { + crc ^= (u_short) *buf << 8; + for (i = 0x80; i; i >>= 1) + if (crc & 0x8000) + crc = crc << 1 ^ crc_16poly; + else + crc <<= 1; + } + + return crc; +} + +/* * crcIP() - Checksum in IP communication * * @buf = Data for calculation * @bufLen = Length of data - * return: -1 error, !=-1 Checksum + * return: Checksum */ -inline u_short +u_short crcIP(u_char * __restrict buf, int bufLen) { register u_int sum; @@ -201,7 +292,7 @@ crcIP(u_char * __restrict buf, int bufLen) assert(buf); - for (sum = 0; bufLen && bufLen > 1; bufLen -= 2) + for (sum = 0; bufLen > 1; bufLen -= 2) sum += *nBuf++; if (bufLen == 1) { *(u_char*)(&last) += *(u_char*) nBuf; @@ -215,13 +306,74 @@ crcIP(u_char * __restrict buf, int bufLen) } /* + * crcTCP() - Checksum for TCP v4 communication + * + * @buf = Data for calculation + * @bufLen = Length of data + * @th = TCP header + * return: Checksum + */ +u_short +crcTCP(struct in_addr src, struct in_addr dst, u_char * __restrict th) +{ + struct psd_tcp { + struct in_addr src; + struct in_addr dst; + u_char pad; + u_char proto; + u_short tcp_len; + u_char tcp[20]; + } buf; + + buf.src = src; + buf.dst = dst; + buf.pad = 0; + buf.proto = IPPROTO_TCP; + buf.tcp_len = htons(sizeof buf.tcp); + memcpy(&buf.tcp, th, sizeof buf.tcp); + + return crcIP((u_char*) &buf, sizeof buf); +} + +/* + * crcUDP() - Checksum for UDP v4 communication + * + * @buf = Data for calculation + * @bufLen = Length of data + * @uh = UDP header + * return: Checksum + */ +u_short +crcUDP(struct in_addr src, struct in_addr dst, u_char * __restrict uh) +{ + struct psd_udp { + struct in_addr src; + struct in_addr dst; + u_char pad; + u_char proto; + u_short udp_len; + u_char udp[8]; + } buf; + + buf.src = src; + buf.dst = dst; + buf.pad = 0; + buf.proto = IPPROTO_UDP; + buf.udp_len = htons(sizeof buf.udp); + memcpy(&buf.udp, uh, sizeof buf.udp); + + return crcIP((u_char*) &buf, sizeof buf); +} + + +/* * crcFletcher16() - Fletcher-16 Checksum computing * * @nBuf = Data for calculation * @bufLen = Length of data - * return: -1 error, !=-1 Checksum + * return: Checksum */ -inline u_short +u_short crcFletcher16(u_short * __restrict nBuf, int bufLen) { register u_short s1, s2; @@ -251,9 +403,9 @@ crcFletcher16(u_short * __restrict nBuf, int bufLen) * * @nBuf = Data for calculation * @bufLen = Length of data - * return: -1 error, !=-1 Checksum + * return: Checksum */ -inline u_int +u_int crcFletcher(u_short * __restrict nBuf, int bufLen) { register u_int s1, s2, clen; @@ -282,9 +434,9 @@ crcFletcher(u_short * __restrict nBuf, int bufLen) * * @psBuf = Data for calculation * @bufLen = Length of data - * return: -1 error, !=-1 Checksum + * return: Checksum */ -inline u_int +u_int crcAdler(u_char * __restrict psBuf, int bufLen) { register u_int s1 = 1, s2 = 0, clen;