1*043036a2SApple OSS Distributions /*
2*043036a2SApple OSS Distributions * Copyright (c) 2000-2018 Apple Inc. All rights reserved.
3*043036a2SApple OSS Distributions *
4*043036a2SApple OSS Distributions * @APPLE_LICENSE_HEADER_START@
5*043036a2SApple OSS Distributions *
6*043036a2SApple OSS Distributions * This file contains Original Code and/or Modifications of Original Code
7*043036a2SApple OSS Distributions * as defined in and that are subject to the Apple Public Source License
8*043036a2SApple OSS Distributions * Version 2.0 (the 'License'). You may not use this file except in
9*043036a2SApple OSS Distributions * compliance with the License. Please obtain a copy of the License at
10*043036a2SApple OSS Distributions * http://www.opensource.apple.com/apsl/ and read it before using this
11*043036a2SApple OSS Distributions * file.
12*043036a2SApple OSS Distributions *
13*043036a2SApple OSS Distributions * The Original Code and all software distributed under the License are
14*043036a2SApple OSS Distributions * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15*043036a2SApple OSS Distributions * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16*043036a2SApple OSS Distributions * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17*043036a2SApple OSS Distributions * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18*043036a2SApple OSS Distributions * Please see the License for the specific language governing rights and
19*043036a2SApple OSS Distributions * limitations under the License.
20*043036a2SApple OSS Distributions *
21*043036a2SApple OSS Distributions * @APPLE_LICENSE_HEADER_END@
22*043036a2SApple OSS Distributions */
23*043036a2SApple OSS Distributions
24*043036a2SApple OSS Distributions /*
25*043036a2SApple OSS Distributions * Copyright (c) 1988, 1992, 1993
26*043036a2SApple OSS Distributions * The Regents of the University of California. All rights reserved.
27*043036a2SApple OSS Distributions *
28*043036a2SApple OSS Distributions * @(#)in_cksum.c 8.1 (Berkeley) 6/10/93
29*043036a2SApple OSS Distributions */
30*043036a2SApple OSS Distributions
31*043036a2SApple OSS Distributions #include <sys/param.h>
32*043036a2SApple OSS Distributions #include "in_cksum.h"
33*043036a2SApple OSS Distributions
34*043036a2SApple OSS Distributions typedef union {
35*043036a2SApple OSS Distributions char c[2];
36*043036a2SApple OSS Distributions u_short s;
37*043036a2SApple OSS Distributions } short_union_t;
38*043036a2SApple OSS Distributions
39*043036a2SApple OSS Distributions typedef union {
40*043036a2SApple OSS Distributions u_short s[2];
41*043036a2SApple OSS Distributions long l;
42*043036a2SApple OSS Distributions } long_union_t;
43*043036a2SApple OSS Distributions
44*043036a2SApple OSS Distributions static __inline__ void
reduce(int * sum)45*043036a2SApple OSS Distributions reduce(int * sum)
46*043036a2SApple OSS Distributions {
47*043036a2SApple OSS Distributions long_union_t l_util;
48*043036a2SApple OSS Distributions
49*043036a2SApple OSS Distributions l_util.l = *sum;
50*043036a2SApple OSS Distributions *sum = l_util.s[0] + l_util.s[1];
51*043036a2SApple OSS Distributions if (*sum > 65535) {
52*043036a2SApple OSS Distributions *sum -= 65535;
53*043036a2SApple OSS Distributions }
54*043036a2SApple OSS Distributions return;
55*043036a2SApple OSS Distributions }
56*043036a2SApple OSS Distributions
57*043036a2SApple OSS Distributions
58*043036a2SApple OSS Distributions #include <stdio.h>
59*043036a2SApple OSS Distributions
60*043036a2SApple OSS Distributions unsigned short
in_cksum(void * pkt,int len)61*043036a2SApple OSS Distributions in_cksum(void * pkt, int len)
62*043036a2SApple OSS Distributions {
63*043036a2SApple OSS Distributions u_short * w;
64*043036a2SApple OSS Distributions int sum = 0;
65*043036a2SApple OSS Distributions
66*043036a2SApple OSS Distributions w = (u_short *)pkt;
67*043036a2SApple OSS Distributions while ((len -= 32) >= 0) {
68*043036a2SApple OSS Distributions sum += w[0]; sum += w[1];
69*043036a2SApple OSS Distributions sum += w[2]; sum += w[3];
70*043036a2SApple OSS Distributions sum += w[4]; sum += w[5];
71*043036a2SApple OSS Distributions sum += w[6]; sum += w[7];
72*043036a2SApple OSS Distributions sum += w[8]; sum += w[9];
73*043036a2SApple OSS Distributions sum += w[10]; sum += w[11];
74*043036a2SApple OSS Distributions sum += w[12]; sum += w[13];
75*043036a2SApple OSS Distributions sum += w[14]; sum += w[15];
76*043036a2SApple OSS Distributions w += 16;
77*043036a2SApple OSS Distributions }
78*043036a2SApple OSS Distributions len += 32;
79*043036a2SApple OSS Distributions while ((len -= 8) >= 0) {
80*043036a2SApple OSS Distributions sum += w[0]; sum += w[1];
81*043036a2SApple OSS Distributions sum += w[2]; sum += w[3];
82*043036a2SApple OSS Distributions w += 4;
83*043036a2SApple OSS Distributions }
84*043036a2SApple OSS Distributions len += 8;
85*043036a2SApple OSS Distributions if (len) {
86*043036a2SApple OSS Distributions reduce(&sum);
87*043036a2SApple OSS Distributions while ((len -= 2) >= 0) {
88*043036a2SApple OSS Distributions sum += *w++;
89*043036a2SApple OSS Distributions }
90*043036a2SApple OSS Distributions }
91*043036a2SApple OSS Distributions if (len == -1) { /* odd-length packet */
92*043036a2SApple OSS Distributions short_union_t s_util;
93*043036a2SApple OSS Distributions
94*043036a2SApple OSS Distributions s_util.s = 0;
95*043036a2SApple OSS Distributions s_util.c[0] = *((char *)w);
96*043036a2SApple OSS Distributions s_util.c[1] = 0;
97*043036a2SApple OSS Distributions sum += s_util.s;
98*043036a2SApple OSS Distributions }
99*043036a2SApple OSS Distributions reduce(&sum);
100*043036a2SApple OSS Distributions return ~sum & 0xffff;
101*043036a2SApple OSS Distributions }
102