1*d4514f0bSApple OSS Distributions /*
2*d4514f0bSApple OSS Distributions * Copyright (c) 2000-2018 Apple Inc. All rights reserved.
3*d4514f0bSApple OSS Distributions *
4*d4514f0bSApple OSS Distributions * @APPLE_LICENSE_HEADER_START@
5*d4514f0bSApple OSS Distributions *
6*d4514f0bSApple OSS Distributions * This file contains Original Code and/or Modifications of Original Code
7*d4514f0bSApple OSS Distributions * as defined in and that are subject to the Apple Public Source License
8*d4514f0bSApple OSS Distributions * Version 2.0 (the 'License'). You may not use this file except in
9*d4514f0bSApple OSS Distributions * compliance with the License. Please obtain a copy of the License at
10*d4514f0bSApple OSS Distributions * http://www.opensource.apple.com/apsl/ and read it before using this
11*d4514f0bSApple OSS Distributions * file.
12*d4514f0bSApple OSS Distributions *
13*d4514f0bSApple OSS Distributions * The Original Code and all software distributed under the License are
14*d4514f0bSApple OSS Distributions * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15*d4514f0bSApple OSS Distributions * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16*d4514f0bSApple OSS Distributions * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17*d4514f0bSApple OSS Distributions * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18*d4514f0bSApple OSS Distributions * Please see the License for the specific language governing rights and
19*d4514f0bSApple OSS Distributions * limitations under the License.
20*d4514f0bSApple OSS Distributions *
21*d4514f0bSApple OSS Distributions * @APPLE_LICENSE_HEADER_END@
22*d4514f0bSApple OSS Distributions */
23*d4514f0bSApple OSS Distributions
24*d4514f0bSApple OSS Distributions /*
25*d4514f0bSApple OSS Distributions * Copyright (c) 1988, 1992, 1993
26*d4514f0bSApple OSS Distributions * The Regents of the University of California. All rights reserved.
27*d4514f0bSApple OSS Distributions *
28*d4514f0bSApple OSS Distributions * @(#)in_cksum.c 8.1 (Berkeley) 6/10/93
29*d4514f0bSApple OSS Distributions */
30*d4514f0bSApple OSS Distributions
31*d4514f0bSApple OSS Distributions #include <sys/param.h>
32*d4514f0bSApple OSS Distributions #include "in_cksum.h"
33*d4514f0bSApple OSS Distributions
34*d4514f0bSApple OSS Distributions typedef union {
35*d4514f0bSApple OSS Distributions char c[2];
36*d4514f0bSApple OSS Distributions u_short s;
37*d4514f0bSApple OSS Distributions } short_union_t;
38*d4514f0bSApple OSS Distributions
39*d4514f0bSApple OSS Distributions typedef union {
40*d4514f0bSApple OSS Distributions u_short s[2];
41*d4514f0bSApple OSS Distributions long l;
42*d4514f0bSApple OSS Distributions } long_union_t;
43*d4514f0bSApple OSS Distributions
44*d4514f0bSApple OSS Distributions static __inline__ void
reduce(int * sum)45*d4514f0bSApple OSS Distributions reduce(int * sum)
46*d4514f0bSApple OSS Distributions {
47*d4514f0bSApple OSS Distributions long_union_t l_util;
48*d4514f0bSApple OSS Distributions
49*d4514f0bSApple OSS Distributions l_util.l = *sum;
50*d4514f0bSApple OSS Distributions *sum = l_util.s[0] + l_util.s[1];
51*d4514f0bSApple OSS Distributions if (*sum > 65535) {
52*d4514f0bSApple OSS Distributions *sum -= 65535;
53*d4514f0bSApple OSS Distributions }
54*d4514f0bSApple OSS Distributions return;
55*d4514f0bSApple OSS Distributions }
56*d4514f0bSApple OSS Distributions
57*d4514f0bSApple OSS Distributions
58*d4514f0bSApple OSS Distributions #include <stdio.h>
59*d4514f0bSApple OSS Distributions
60*d4514f0bSApple OSS Distributions unsigned short
in_cksum(void * pkt,int len)61*d4514f0bSApple OSS Distributions in_cksum(void * pkt, int len)
62*d4514f0bSApple OSS Distributions {
63*d4514f0bSApple OSS Distributions u_short * w;
64*d4514f0bSApple OSS Distributions int sum = 0;
65*d4514f0bSApple OSS Distributions
66*d4514f0bSApple OSS Distributions w = (u_short *)pkt;
67*d4514f0bSApple OSS Distributions while ((len -= 32) >= 0) {
68*d4514f0bSApple OSS Distributions sum += w[0]; sum += w[1];
69*d4514f0bSApple OSS Distributions sum += w[2]; sum += w[3];
70*d4514f0bSApple OSS Distributions sum += w[4]; sum += w[5];
71*d4514f0bSApple OSS Distributions sum += w[6]; sum += w[7];
72*d4514f0bSApple OSS Distributions sum += w[8]; sum += w[9];
73*d4514f0bSApple OSS Distributions sum += w[10]; sum += w[11];
74*d4514f0bSApple OSS Distributions sum += w[12]; sum += w[13];
75*d4514f0bSApple OSS Distributions sum += w[14]; sum += w[15];
76*d4514f0bSApple OSS Distributions w += 16;
77*d4514f0bSApple OSS Distributions }
78*d4514f0bSApple OSS Distributions len += 32;
79*d4514f0bSApple OSS Distributions while ((len -= 8) >= 0) {
80*d4514f0bSApple OSS Distributions sum += w[0]; sum += w[1];
81*d4514f0bSApple OSS Distributions sum += w[2]; sum += w[3];
82*d4514f0bSApple OSS Distributions w += 4;
83*d4514f0bSApple OSS Distributions }
84*d4514f0bSApple OSS Distributions len += 8;
85*d4514f0bSApple OSS Distributions if (len) {
86*d4514f0bSApple OSS Distributions reduce(&sum);
87*d4514f0bSApple OSS Distributions while ((len -= 2) >= 0) {
88*d4514f0bSApple OSS Distributions sum += *w++;
89*d4514f0bSApple OSS Distributions }
90*d4514f0bSApple OSS Distributions }
91*d4514f0bSApple OSS Distributions if (len == -1) { /* odd-length packet */
92*d4514f0bSApple OSS Distributions short_union_t s_util;
93*d4514f0bSApple OSS Distributions
94*d4514f0bSApple OSS Distributions s_util.s = 0;
95*d4514f0bSApple OSS Distributions s_util.c[0] = *((char *)w);
96*d4514f0bSApple OSS Distributions s_util.c[1] = 0;
97*d4514f0bSApple OSS Distributions sum += s_util.s;
98*d4514f0bSApple OSS Distributions }
99*d4514f0bSApple OSS Distributions reduce(&sum);
100*d4514f0bSApple OSS Distributions return ~sum & 0xffff;
101*d4514f0bSApple OSS Distributions }
102