1*fdd8201dSApple OSS Distributions /*
2*fdd8201dSApple OSS Distributions * Copyright (c) 2000-2018 Apple Inc. All rights reserved.
3*fdd8201dSApple OSS Distributions *
4*fdd8201dSApple OSS Distributions * @APPLE_LICENSE_HEADER_START@
5*fdd8201dSApple OSS Distributions *
6*fdd8201dSApple OSS Distributions * This file contains Original Code and/or Modifications of Original Code
7*fdd8201dSApple OSS Distributions * as defined in and that are subject to the Apple Public Source License
8*fdd8201dSApple OSS Distributions * Version 2.0 (the 'License'). You may not use this file except in
9*fdd8201dSApple OSS Distributions * compliance with the License. Please obtain a copy of the License at
10*fdd8201dSApple OSS Distributions * http://www.opensource.apple.com/apsl/ and read it before using this
11*fdd8201dSApple OSS Distributions * file.
12*fdd8201dSApple OSS Distributions *
13*fdd8201dSApple OSS Distributions * The Original Code and all software distributed under the License are
14*fdd8201dSApple OSS Distributions * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15*fdd8201dSApple OSS Distributions * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16*fdd8201dSApple OSS Distributions * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17*fdd8201dSApple OSS Distributions * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18*fdd8201dSApple OSS Distributions * Please see the License for the specific language governing rights and
19*fdd8201dSApple OSS Distributions * limitations under the License.
20*fdd8201dSApple OSS Distributions *
21*fdd8201dSApple OSS Distributions * @APPLE_LICENSE_HEADER_END@
22*fdd8201dSApple OSS Distributions */
23*fdd8201dSApple OSS Distributions
24*fdd8201dSApple OSS Distributions /*
25*fdd8201dSApple OSS Distributions * Copyright (c) 1988, 1992, 1993
26*fdd8201dSApple OSS Distributions * The Regents of the University of California. All rights reserved.
27*fdd8201dSApple OSS Distributions *
28*fdd8201dSApple OSS Distributions * @(#)in_cksum.c 8.1 (Berkeley) 6/10/93
29*fdd8201dSApple OSS Distributions */
30*fdd8201dSApple OSS Distributions
31*fdd8201dSApple OSS Distributions #include <sys/param.h>
32*fdd8201dSApple OSS Distributions #include "in_cksum.h"
33*fdd8201dSApple OSS Distributions
34*fdd8201dSApple OSS Distributions typedef union {
35*fdd8201dSApple OSS Distributions char c[2];
36*fdd8201dSApple OSS Distributions u_short s;
37*fdd8201dSApple OSS Distributions } short_union_t;
38*fdd8201dSApple OSS Distributions
39*fdd8201dSApple OSS Distributions typedef union {
40*fdd8201dSApple OSS Distributions u_short s[2];
41*fdd8201dSApple OSS Distributions long l;
42*fdd8201dSApple OSS Distributions } long_union_t;
43*fdd8201dSApple OSS Distributions
44*fdd8201dSApple OSS Distributions static __inline__ void
reduce(int * sum)45*fdd8201dSApple OSS Distributions reduce(int * sum)
46*fdd8201dSApple OSS Distributions {
47*fdd8201dSApple OSS Distributions long_union_t l_util;
48*fdd8201dSApple OSS Distributions
49*fdd8201dSApple OSS Distributions l_util.l = *sum;
50*fdd8201dSApple OSS Distributions *sum = l_util.s[0] + l_util.s[1];
51*fdd8201dSApple OSS Distributions if (*sum > 65535) {
52*fdd8201dSApple OSS Distributions *sum -= 65535;
53*fdd8201dSApple OSS Distributions }
54*fdd8201dSApple OSS Distributions return;
55*fdd8201dSApple OSS Distributions }
56*fdd8201dSApple OSS Distributions
57*fdd8201dSApple OSS Distributions
58*fdd8201dSApple OSS Distributions #include <stdio.h>
59*fdd8201dSApple OSS Distributions
60*fdd8201dSApple OSS Distributions unsigned short
in_cksum(void * pkt,int len)61*fdd8201dSApple OSS Distributions in_cksum(void * pkt, int len)
62*fdd8201dSApple OSS Distributions {
63*fdd8201dSApple OSS Distributions u_short * w;
64*fdd8201dSApple OSS Distributions int sum = 0;
65*fdd8201dSApple OSS Distributions
66*fdd8201dSApple OSS Distributions w = (u_short *)pkt;
67*fdd8201dSApple OSS Distributions while ((len -= 32) >= 0) {
68*fdd8201dSApple OSS Distributions sum += w[0]; sum += w[1];
69*fdd8201dSApple OSS Distributions sum += w[2]; sum += w[3];
70*fdd8201dSApple OSS Distributions sum += w[4]; sum += w[5];
71*fdd8201dSApple OSS Distributions sum += w[6]; sum += w[7];
72*fdd8201dSApple OSS Distributions sum += w[8]; sum += w[9];
73*fdd8201dSApple OSS Distributions sum += w[10]; sum += w[11];
74*fdd8201dSApple OSS Distributions sum += w[12]; sum += w[13];
75*fdd8201dSApple OSS Distributions sum += w[14]; sum += w[15];
76*fdd8201dSApple OSS Distributions w += 16;
77*fdd8201dSApple OSS Distributions }
78*fdd8201dSApple OSS Distributions len += 32;
79*fdd8201dSApple OSS Distributions while ((len -= 8) >= 0) {
80*fdd8201dSApple OSS Distributions sum += w[0]; sum += w[1];
81*fdd8201dSApple OSS Distributions sum += w[2]; sum += w[3];
82*fdd8201dSApple OSS Distributions w += 4;
83*fdd8201dSApple OSS Distributions }
84*fdd8201dSApple OSS Distributions len += 8;
85*fdd8201dSApple OSS Distributions if (len) {
86*fdd8201dSApple OSS Distributions reduce(&sum);
87*fdd8201dSApple OSS Distributions while ((len -= 2) >= 0) {
88*fdd8201dSApple OSS Distributions sum += *w++;
89*fdd8201dSApple OSS Distributions }
90*fdd8201dSApple OSS Distributions }
91*fdd8201dSApple OSS Distributions if (len == -1) { /* odd-length packet */
92*fdd8201dSApple OSS Distributions short_union_t s_util;
93*fdd8201dSApple OSS Distributions
94*fdd8201dSApple OSS Distributions s_util.s = 0;
95*fdd8201dSApple OSS Distributions s_util.c[0] = *((char *)w);
96*fdd8201dSApple OSS Distributions s_util.c[1] = 0;
97*fdd8201dSApple OSS Distributions sum += s_util.s;
98*fdd8201dSApple OSS Distributions }
99*fdd8201dSApple OSS Distributions reduce(&sum);
100*fdd8201dSApple OSS Distributions return ~sum & 0xffff;
101*fdd8201dSApple OSS Distributions }
102