1*c54f35caSApple OSS Distributions /*
2*c54f35caSApple OSS Distributions * Copyright (c) 2000-2018 Apple Inc. All rights reserved.
3*c54f35caSApple OSS Distributions *
4*c54f35caSApple OSS Distributions * @APPLE_LICENSE_HEADER_START@
5*c54f35caSApple OSS Distributions *
6*c54f35caSApple OSS Distributions * This file contains Original Code and/or Modifications of Original Code
7*c54f35caSApple OSS Distributions * as defined in and that are subject to the Apple Public Source License
8*c54f35caSApple OSS Distributions * Version 2.0 (the 'License'). You may not use this file except in
9*c54f35caSApple OSS Distributions * compliance with the License. Please obtain a copy of the License at
10*c54f35caSApple OSS Distributions * http://www.opensource.apple.com/apsl/ and read it before using this
11*c54f35caSApple OSS Distributions * file.
12*c54f35caSApple OSS Distributions *
13*c54f35caSApple OSS Distributions * The Original Code and all software distributed under the License are
14*c54f35caSApple OSS Distributions * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15*c54f35caSApple OSS Distributions * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16*c54f35caSApple OSS Distributions * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17*c54f35caSApple OSS Distributions * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18*c54f35caSApple OSS Distributions * Please see the License for the specific language governing rights and
19*c54f35caSApple OSS Distributions * limitations under the License.
20*c54f35caSApple OSS Distributions *
21*c54f35caSApple OSS Distributions * @APPLE_LICENSE_HEADER_END@
22*c54f35caSApple OSS Distributions */
23*c54f35caSApple OSS Distributions
24*c54f35caSApple OSS Distributions /*
25*c54f35caSApple OSS Distributions * Copyright (c) 1988, 1992, 1993
26*c54f35caSApple OSS Distributions * The Regents of the University of California. All rights reserved.
27*c54f35caSApple OSS Distributions *
28*c54f35caSApple OSS Distributions * @(#)in_cksum.c 8.1 (Berkeley) 6/10/93
29*c54f35caSApple OSS Distributions */
30*c54f35caSApple OSS Distributions
31*c54f35caSApple OSS Distributions #include <sys/param.h>
32*c54f35caSApple OSS Distributions #include "in_cksum.h"
33*c54f35caSApple OSS Distributions
34*c54f35caSApple OSS Distributions typedef union {
35*c54f35caSApple OSS Distributions char c[2];
36*c54f35caSApple OSS Distributions u_short s;
37*c54f35caSApple OSS Distributions } short_union_t;
38*c54f35caSApple OSS Distributions
39*c54f35caSApple OSS Distributions typedef union {
40*c54f35caSApple OSS Distributions u_short s[2];
41*c54f35caSApple OSS Distributions long l;
42*c54f35caSApple OSS Distributions } long_union_t;
43*c54f35caSApple OSS Distributions
44*c54f35caSApple OSS Distributions static __inline__ void
reduce(int * sum)45*c54f35caSApple OSS Distributions reduce(int * sum)
46*c54f35caSApple OSS Distributions {
47*c54f35caSApple OSS Distributions long_union_t l_util;
48*c54f35caSApple OSS Distributions
49*c54f35caSApple OSS Distributions l_util.l = *sum;
50*c54f35caSApple OSS Distributions *sum = l_util.s[0] + l_util.s[1];
51*c54f35caSApple OSS Distributions if (*sum > 65535) {
52*c54f35caSApple OSS Distributions *sum -= 65535;
53*c54f35caSApple OSS Distributions }
54*c54f35caSApple OSS Distributions return;
55*c54f35caSApple OSS Distributions }
56*c54f35caSApple OSS Distributions
57*c54f35caSApple OSS Distributions
58*c54f35caSApple OSS Distributions #include <stdio.h>
59*c54f35caSApple OSS Distributions
60*c54f35caSApple OSS Distributions unsigned short
in_cksum(void * pkt,int len)61*c54f35caSApple OSS Distributions in_cksum(void * pkt, int len)
62*c54f35caSApple OSS Distributions {
63*c54f35caSApple OSS Distributions u_short * w;
64*c54f35caSApple OSS Distributions int sum = 0;
65*c54f35caSApple OSS Distributions
66*c54f35caSApple OSS Distributions w = (u_short *)pkt;
67*c54f35caSApple OSS Distributions while ((len -= 32) >= 0) {
68*c54f35caSApple OSS Distributions sum += w[0]; sum += w[1];
69*c54f35caSApple OSS Distributions sum += w[2]; sum += w[3];
70*c54f35caSApple OSS Distributions sum += w[4]; sum += w[5];
71*c54f35caSApple OSS Distributions sum += w[6]; sum += w[7];
72*c54f35caSApple OSS Distributions sum += w[8]; sum += w[9];
73*c54f35caSApple OSS Distributions sum += w[10]; sum += w[11];
74*c54f35caSApple OSS Distributions sum += w[12]; sum += w[13];
75*c54f35caSApple OSS Distributions sum += w[14]; sum += w[15];
76*c54f35caSApple OSS Distributions w += 16;
77*c54f35caSApple OSS Distributions }
78*c54f35caSApple OSS Distributions len += 32;
79*c54f35caSApple OSS Distributions while ((len -= 8) >= 0) {
80*c54f35caSApple OSS Distributions sum += w[0]; sum += w[1];
81*c54f35caSApple OSS Distributions sum += w[2]; sum += w[3];
82*c54f35caSApple OSS Distributions w += 4;
83*c54f35caSApple OSS Distributions }
84*c54f35caSApple OSS Distributions len += 8;
85*c54f35caSApple OSS Distributions if (len) {
86*c54f35caSApple OSS Distributions reduce(&sum);
87*c54f35caSApple OSS Distributions while ((len -= 2) >= 0) {
88*c54f35caSApple OSS Distributions sum += *w++;
89*c54f35caSApple OSS Distributions }
90*c54f35caSApple OSS Distributions }
91*c54f35caSApple OSS Distributions if (len == -1) { /* odd-length packet */
92*c54f35caSApple OSS Distributions short_union_t s_util;
93*c54f35caSApple OSS Distributions
94*c54f35caSApple OSS Distributions s_util.s = 0;
95*c54f35caSApple OSS Distributions s_util.c[0] = *((char *)w);
96*c54f35caSApple OSS Distributions s_util.c[1] = 0;
97*c54f35caSApple OSS Distributions sum += s_util.s;
98*c54f35caSApple OSS Distributions }
99*c54f35caSApple OSS Distributions reduce(&sum);
100*c54f35caSApple OSS Distributions return ~sum & 0xffff;
101*c54f35caSApple OSS Distributions }
102