--- libelwix/src/crc.c 2013/01/17 10:05:35 1.1
+++ libelwix/src/crc.c 2019/12/30 18:11:16 1.6
@@ -3,7 +3,7 @@
* by Michael Pounov <misho@openbsd-bg.org>
*
* $Author: misho $
-* $Id: crc.c,v 1.1 2013/01/17 10:05:35 misho Exp $
+* $Id: crc.c,v 1.6 2019/12/30 18:11:16 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 <info@elwix.org>
-Copyright 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013
+Copyright 2004 - 2019
by Michael Pounov <misho@elwix.org>. 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;
@@ -73,14 +76,14 @@ 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, rev;
+ register u_int i, j = 1, rev = 0;
- for (i = (u_int) 1 << (crcBits - 1), j = 1, rev ^= rev; i; i >>= 1, j <<= 1)
+ for (i = (u_int) 1 << (crcBits - 1); i; i >>= 1, j <<= 1)
if (crcNum & i)
rev |= j;
return rev;
@@ -95,9 +98,9 @@ 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;
@@ -187,13 +190,75 @@ crcCalc(u_char * __restrict psBuf, u_int bufLen, u_cha
/*
+ * crc16_ext() - Checksum ver.2 calculation in X/Y modem communication
+ *
+ * @buf = Data for calculation
+ * @bufLen = Length of data
+ * return: Checksum
+ */
+u_short
+crc16_ext(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() - Checksum calculation in X/Y modem communication
+ *
+ * @buf = Data for calculation
+ * @bufLen = Length of data
+ * return: Checksum
+ */
+u_short
+crc16(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 +266,7 @@ 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 +280,74 @@ 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 +377,9 @@ 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;
@@ -282,17 +408,15 @@ 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, s2, clen;
+ register u_int s1 = 1, s2 = 0, clen;
assert(psBuf);
- s1 = 1L;
- s2 ^= s2;
while (bufLen) {
clen = bufLen > MAX_ADLER_DIGEST ? MAX_ADLER_DIGEST : bufLen;
bufLen -= clen;