1*2c2f96dcSApple OSS Distributions /*
2*2c2f96dcSApple OSS Distributions * Copyright (c) 2000-2018 Apple Inc. All rights reserved.
3*2c2f96dcSApple OSS Distributions *
4*2c2f96dcSApple OSS Distributions * @APPLE_LICENSE_HEADER_START@
5*2c2f96dcSApple OSS Distributions *
6*2c2f96dcSApple OSS Distributions * This file contains Original Code and/or Modifications of Original Code
7*2c2f96dcSApple OSS Distributions * as defined in and that are subject to the Apple Public Source License
8*2c2f96dcSApple OSS Distributions * Version 2.0 (the 'License'). You may not use this file except in
9*2c2f96dcSApple OSS Distributions * compliance with the License. Please obtain a copy of the License at
10*2c2f96dcSApple OSS Distributions * http://www.opensource.apple.com/apsl/ and read it before using this
11*2c2f96dcSApple OSS Distributions * file.
12*2c2f96dcSApple OSS Distributions *
13*2c2f96dcSApple OSS Distributions * The Original Code and all software distributed under the License are
14*2c2f96dcSApple OSS Distributions * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15*2c2f96dcSApple OSS Distributions * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16*2c2f96dcSApple OSS Distributions * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17*2c2f96dcSApple OSS Distributions * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18*2c2f96dcSApple OSS Distributions * Please see the License for the specific language governing rights and
19*2c2f96dcSApple OSS Distributions * limitations under the License.
20*2c2f96dcSApple OSS Distributions *
21*2c2f96dcSApple OSS Distributions * @APPLE_LICENSE_HEADER_END@
22*2c2f96dcSApple OSS Distributions */
23*2c2f96dcSApple OSS Distributions
24*2c2f96dcSApple OSS Distributions /*
25*2c2f96dcSApple OSS Distributions * Copyright (c) 1988, 1992, 1993
26*2c2f96dcSApple OSS Distributions * The Regents of the University of California. All rights reserved.
27*2c2f96dcSApple OSS Distributions *
28*2c2f96dcSApple OSS Distributions * @(#)in_cksum.c 8.1 (Berkeley) 6/10/93
29*2c2f96dcSApple OSS Distributions */
30*2c2f96dcSApple OSS Distributions
31*2c2f96dcSApple OSS Distributions #include <sys/param.h>
32*2c2f96dcSApple OSS Distributions #include "in_cksum.h"
33*2c2f96dcSApple OSS Distributions
34*2c2f96dcSApple OSS Distributions typedef union {
35*2c2f96dcSApple OSS Distributions char c[2];
36*2c2f96dcSApple OSS Distributions u_short s;
37*2c2f96dcSApple OSS Distributions } short_union_t;
38*2c2f96dcSApple OSS Distributions
39*2c2f96dcSApple OSS Distributions typedef union {
40*2c2f96dcSApple OSS Distributions u_short s[2];
41*2c2f96dcSApple OSS Distributions long l;
42*2c2f96dcSApple OSS Distributions } long_union_t;
43*2c2f96dcSApple OSS Distributions
44*2c2f96dcSApple OSS Distributions static __inline__ void
reduce(int * sum)45*2c2f96dcSApple OSS Distributions reduce(int * sum)
46*2c2f96dcSApple OSS Distributions {
47*2c2f96dcSApple OSS Distributions long_union_t l_util;
48*2c2f96dcSApple OSS Distributions
49*2c2f96dcSApple OSS Distributions l_util.l = *sum;
50*2c2f96dcSApple OSS Distributions *sum = l_util.s[0] + l_util.s[1];
51*2c2f96dcSApple OSS Distributions if (*sum > 65535) {
52*2c2f96dcSApple OSS Distributions *sum -= 65535;
53*2c2f96dcSApple OSS Distributions }
54*2c2f96dcSApple OSS Distributions return;
55*2c2f96dcSApple OSS Distributions }
56*2c2f96dcSApple OSS Distributions
57*2c2f96dcSApple OSS Distributions
58*2c2f96dcSApple OSS Distributions #include <stdio.h>
59*2c2f96dcSApple OSS Distributions
60*2c2f96dcSApple OSS Distributions unsigned short
in_cksum(void * pkt,int len)61*2c2f96dcSApple OSS Distributions in_cksum(void * pkt, int len)
62*2c2f96dcSApple OSS Distributions {
63*2c2f96dcSApple OSS Distributions u_short * w;
64*2c2f96dcSApple OSS Distributions int sum = 0;
65*2c2f96dcSApple OSS Distributions
66*2c2f96dcSApple OSS Distributions w = (u_short *)pkt;
67*2c2f96dcSApple OSS Distributions while ((len -= 32) >= 0) {
68*2c2f96dcSApple OSS Distributions sum += w[0]; sum += w[1];
69*2c2f96dcSApple OSS Distributions sum += w[2]; sum += w[3];
70*2c2f96dcSApple OSS Distributions sum += w[4]; sum += w[5];
71*2c2f96dcSApple OSS Distributions sum += w[6]; sum += w[7];
72*2c2f96dcSApple OSS Distributions sum += w[8]; sum += w[9];
73*2c2f96dcSApple OSS Distributions sum += w[10]; sum += w[11];
74*2c2f96dcSApple OSS Distributions sum += w[12]; sum += w[13];
75*2c2f96dcSApple OSS Distributions sum += w[14]; sum += w[15];
76*2c2f96dcSApple OSS Distributions w += 16;
77*2c2f96dcSApple OSS Distributions }
78*2c2f96dcSApple OSS Distributions len += 32;
79*2c2f96dcSApple OSS Distributions while ((len -= 8) >= 0) {
80*2c2f96dcSApple OSS Distributions sum += w[0]; sum += w[1];
81*2c2f96dcSApple OSS Distributions sum += w[2]; sum += w[3];
82*2c2f96dcSApple OSS Distributions w += 4;
83*2c2f96dcSApple OSS Distributions }
84*2c2f96dcSApple OSS Distributions len += 8;
85*2c2f96dcSApple OSS Distributions if (len) {
86*2c2f96dcSApple OSS Distributions reduce(&sum);
87*2c2f96dcSApple OSS Distributions while ((len -= 2) >= 0) {
88*2c2f96dcSApple OSS Distributions sum += *w++;
89*2c2f96dcSApple OSS Distributions }
90*2c2f96dcSApple OSS Distributions }
91*2c2f96dcSApple OSS Distributions if (len == -1) { /* odd-length packet */
92*2c2f96dcSApple OSS Distributions short_union_t s_util;
93*2c2f96dcSApple OSS Distributions
94*2c2f96dcSApple OSS Distributions s_util.s = 0;
95*2c2f96dcSApple OSS Distributions s_util.c[0] = *((char *)w);
96*2c2f96dcSApple OSS Distributions s_util.c[1] = 0;
97*2c2f96dcSApple OSS Distributions sum += s_util.s;
98*2c2f96dcSApple OSS Distributions }
99*2c2f96dcSApple OSS Distributions reduce(&sum);
100*2c2f96dcSApple OSS Distributions return ~sum & 0xffff;
101*2c2f96dcSApple OSS Distributions }
102