1/*	$KAME: sctp_crc32.c,v 1.12 2005/03/06 16:04:17 itojun Exp $	*/
2/*	$NetBSD: sctp_crc32.c,v 1.3 2019/08/13 19:55:40 rjs Exp $ */
3
4/*
5 * Copyright (c) 2001, 2002, 2003, 2004 Cisco Systems, Inc.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *      This product includes software developed by Cisco Systems, Inc.
19 * 4. Neither the name of the project nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY CISCO SYSTEMS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL CISCO SYSTEMS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include <sys/cdefs.h>
37__KERNEL_RCSID(0, "$NetBSD: sctp_crc32.c,v 1.3 2019/08/13 19:55:40 rjs Exp $");
38
39#ifdef _KERNEL_OPT
40#include "opt_sctp.h"
41#endif /* _KERNEL_OPT */
42
43#include <sys/param.h>
44#include <netinet/sctp_crc32.h>
45
46#define SCTP_CRC32C_POLY 0x1EDC6F41
47#define SCTP_CRC32C(c, d) (c = ((c) >> 8) ^ sctp_crc_c[((c) ^ (d)) & 0xFF])
48
49/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
50/* Copyright 2001, D. Otis.  Use this program, code or tables    */
51/* extracted from it, as desired without restriction.            */
52/*                                                               */
53/* 32 Bit Reflected CRC table generation for SCTP.               */
54/* To accommodate serial byte data being shifted out least       */
55/* significant bit first, the table's 32 bit words are reflected */
56/* which flips both byte and bit MS and LS positions.  The CRC   */
57/* is calculated MS bits first from the perspective of the serial*/
58/* stream.  The x^32 term is implied and the x^0 term may also   */
59/* be shown as +1.  The polynomial code used is 0x1EDC6F41.      */
60/* Castagnoli93                                                  */
61/* x^32+x^28+x^27+x^26+x^25+x^23+x^22+x^20+x^19+x^18+x^14+x^13+  */
62/* x^11+x^10+x^9+x^8+x^6+x^0                                     */
63/* Guy Castagnoli Stefan Braeuer and Martin Herrman              */
64/* "Optimization of Cyclic Redundancy-Check Codes                */
65/* with 24 and 32 Parity Bits",                                  */
66/* IEEE Transactions on Communications, Vol.41, No.6, June 1993  */
67/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
68
69const unsigned long  sctp_crc_c[256] = {
70	0x00000000L, 0xF26B8303L, 0xE13B70F7L, 0x1350F3F4L,
71	0xC79A971FL, 0x35F1141CL, 0x26A1E7E8L, 0xD4CA64EBL,
72	0x8AD958CFL, 0x78B2DBCCL, 0x6BE22838L, 0x9989AB3BL,
73	0x4D43CFD0L, 0xBF284CD3L, 0xAC78BF27L, 0x5E133C24L,
74	0x105EC76FL, 0xE235446CL, 0xF165B798L, 0x030E349BL,
75	0xD7C45070L, 0x25AFD373L, 0x36FF2087L, 0xC494A384L,
76	0x9A879FA0L, 0x68EC1CA3L, 0x7BBCEF57L, 0x89D76C54L,
77	0x5D1D08BFL, 0xAF768BBCL, 0xBC267848L, 0x4E4DFB4BL,
78	0x20BD8EDEL, 0xD2D60DDDL, 0xC186FE29L, 0x33ED7D2AL,
79	0xE72719C1L, 0x154C9AC2L, 0x061C6936L, 0xF477EA35L,
80	0xAA64D611L, 0x580F5512L, 0x4B5FA6E6L, 0xB93425E5L,
81	0x6DFE410EL, 0x9F95C20DL, 0x8CC531F9L, 0x7EAEB2FAL,
82	0x30E349B1L, 0xC288CAB2L, 0xD1D83946L, 0x23B3BA45L,
83	0xF779DEAEL, 0x05125DADL, 0x1642AE59L, 0xE4292D5AL,
84	0xBA3A117EL, 0x4851927DL, 0x5B016189L, 0xA96AE28AL,
85	0x7DA08661L, 0x8FCB0562L, 0x9C9BF696L, 0x6EF07595L,
86	0x417B1DBCL, 0xB3109EBFL, 0xA0406D4BL, 0x522BEE48L,
87	0x86E18AA3L, 0x748A09A0L, 0x67DAFA54L, 0x95B17957L,
88	0xCBA24573L, 0x39C9C670L, 0x2A993584L, 0xD8F2B687L,
89	0x0C38D26CL, 0xFE53516FL, 0xED03A29BL, 0x1F682198L,
90	0x5125DAD3L, 0xA34E59D0L, 0xB01EAA24L, 0x42752927L,
91	0x96BF4DCCL, 0x64D4CECFL, 0x77843D3BL, 0x85EFBE38L,
92	0xDBFC821CL, 0x2997011FL, 0x3AC7F2EBL, 0xC8AC71E8L,
93	0x1C661503L, 0xEE0D9600L, 0xFD5D65F4L, 0x0F36E6F7L,
94	0x61C69362L, 0x93AD1061L, 0x80FDE395L, 0x72966096L,
95	0xA65C047DL, 0x5437877EL, 0x4767748AL, 0xB50CF789L,
96	0xEB1FCBADL, 0x197448AEL, 0x0A24BB5AL, 0xF84F3859L,
97	0x2C855CB2L, 0xDEEEDFB1L, 0xCDBE2C45L, 0x3FD5AF46L,
98	0x7198540DL, 0x83F3D70EL, 0x90A324FAL, 0x62C8A7F9L,
99	0xB602C312L, 0x44694011L, 0x5739B3E5L, 0xA55230E6L,
100	0xFB410CC2L, 0x092A8FC1L, 0x1A7A7C35L, 0xE811FF36L,
101	0x3CDB9BDDL, 0xCEB018DEL, 0xDDE0EB2AL, 0x2F8B6829L,
102	0x82F63B78L, 0x709DB87BL, 0x63CD4B8FL, 0x91A6C88CL,
103	0x456CAC67L, 0xB7072F64L, 0xA457DC90L, 0x563C5F93L,
104	0x082F63B7L, 0xFA44E0B4L, 0xE9141340L, 0x1B7F9043L,
105	0xCFB5F4A8L, 0x3DDE77ABL, 0x2E8E845FL, 0xDCE5075CL,
106	0x92A8FC17L, 0x60C37F14L, 0x73938CE0L, 0x81F80FE3L,
107	0x55326B08L, 0xA759E80BL, 0xB4091BFFL, 0x466298FCL,
108	0x1871A4D8L, 0xEA1A27DBL, 0xF94AD42FL, 0x0B21572CL,
109	0xDFEB33C7L, 0x2D80B0C4L, 0x3ED04330L, 0xCCBBC033L,
110	0xA24BB5A6L, 0x502036A5L, 0x4370C551L, 0xB11B4652L,
111	0x65D122B9L, 0x97BAA1BAL, 0x84EA524EL, 0x7681D14DL,
112	0x2892ED69L, 0xDAF96E6AL, 0xC9A99D9EL, 0x3BC21E9DL,
113	0xEF087A76L, 0x1D63F975L, 0x0E330A81L, 0xFC588982L,
114	0xB21572C9L, 0x407EF1CAL, 0x532E023EL, 0xA145813DL,
115	0x758FE5D6L, 0x87E466D5L, 0x94B49521L, 0x66DF1622L,
116	0x38CC2A06L, 0xCAA7A905L, 0xD9F75AF1L, 0x2B9CD9F2L,
117	0xFF56BD19L, 0x0D3D3E1AL, 0x1E6DCDEEL, 0xEC064EEDL,
118	0xC38D26C4L, 0x31E6A5C7L, 0x22B65633L, 0xD0DDD530L,
119	0x0417B1DBL, 0xF67C32D8L, 0xE52CC12CL, 0x1747422FL,
120	0x49547E0BL, 0xBB3FFD08L, 0xA86F0EFCL, 0x5A048DFFL,
121	0x8ECEE914L, 0x7CA56A17L, 0x6FF599E3L, 0x9D9E1AE0L,
122	0xD3D3E1ABL, 0x21B862A8L, 0x32E8915CL, 0xC083125FL,
123	0x144976B4L, 0xE622F5B7L, 0xF5720643L, 0x07198540L,
124	0x590AB964L, 0xAB613A67L, 0xB831C993L, 0x4A5A4A90L,
125	0x9E902E7BL, 0x6CFBAD78L, 0x7FAB5E8CL, 0x8DC0DD8FL,
126	0xE330A81AL, 0x115B2B19L, 0x020BD8EDL, 0xF0605BEEL,
127	0x24AA3F05L, 0xD6C1BC06L, 0xC5914FF2L, 0x37FACCF1L,
128	0x69E9F0D5L, 0x9B8273D6L, 0x88D28022L, 0x7AB90321L,
129	0xAE7367CAL, 0x5C18E4C9L, 0x4F48173DL, 0xBD23943EL,
130	0xF36E6F75L, 0x0105EC76L, 0x12551F82L, 0xE03E9C81L,
131	0x34F4F86AL, 0xC69F7B69L, 0xD5CF889DL, 0x27A40B9EL,
132	0x79B737BAL, 0x8BDCB4B9L, 0x988C474DL, 0x6AE7C44EL,
133	0xBE2DA0A5L, 0x4C4623A6L, 0x5F16D052L, 0xAD7D5351L,
134};
135
136u_int32_t
137update_crc32(u_int32_t crc32c,
138	     unsigned char *buffer,
139	     unsigned int length)
140{
141	unsigned int i;
142
143	for (i = 0; i < length; i++) {
144		SCTP_CRC32C(crc32c, buffer[i]);
145	}
146	return (crc32c);
147}
148
149
150u_int32_t
151sctp_csum_finalize(u_int32_t crc32c)
152{
153	u_int32_t result;
154#if BYTE_ORDER == BIG_ENDIAN
155	u_int8_t byte0, byte1, byte2, byte3;
156#endif
157	/* Complement the result */
158	result = ~crc32c;
159#if BYTE_ORDER == BIG_ENDIAN
160	/*
161	 * For BIG-ENDIAN.. aka Motorola byte order the result is in
162	 * little-endian form. So we must manually swap the bytes. Then
163	 * we can call htonl() which does nothing...
164	 */
165	byte0 = result & 0x000000ff;
166	byte1 = (result >> 8) & 0x000000ff;
167	byte2 = (result >> 16) & 0x000000ff;
168	byte3 = (result >> 24) & 0x000000ff;
169	result = ((byte0 << 24) | (byte1 << 16) | (byte2 << 8) | byte3);
170	crc32c = htonl(result);
171#else
172	/*
173	 * For INTEL platforms the result comes out in network order.
174	 * No htonl is required or the swap above. So we optimize out
175	 * both the htonl and the manual swap above.
176	 */
177	crc32c = result;
178#endif
179	return (crc32c);
180}
181
182