projects / apple / xnu.git / blame
| Commit | Line | Data |
|---|---|---|
| ea3f0419 A |
1 | /* |
| 2 | * Copyright (c) 2000-2018 Apple Inc. All rights reserved. | |
| 3 | * | |
| 4 | * @APPLE_LICENSE_HEADER_START@ | |
| 5 | * | |
| 6 | * This file contains Original Code and/or Modifications of Original Code | |
| 7 | * as defined in and that are subject to the Apple Public Source License | |
| 8 | * Version 2.0 (the 'License'). You may not use this file except in | |
| 9 | * compliance with the License. Please obtain a copy of the License at | |
| 10 | * http://www.opensource.apple.com/apsl/ and read it before using this | |
| 11 | * file. | |
| 12 | * | |
| 13 | * The Original Code and all software distributed under the License are | |
| 14 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER | |
| 15 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, | |
| 16 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, | |
| 17 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. | |
| 18 | * Please see the License for the specific language governing rights and | |
| 19 | * limitations under the License. | |
| 20 | * | |
| 21 | * @APPLE_LICENSE_HEADER_END@ | |
| 22 | */ | |
| 23 | ||
| 24 | /* | |
| 25 | * Copyright (c) 1988, 1992, 1993 | |
| 26 | * The Regents of the University of California. All rights reserved. | |
| 27 | * | |
| 28 | * @(#)in_cksum.c 8.1 (Berkeley) 6/10/93 | |
| 29 | */ | |
| 30 | ||
| 31 | #include <sys/param.h> | |
| 32 | #include "in_cksum.h" | |
| 33 | ||
| 34 | typedef union { | |
| 35 | char c[2]; | |
| 36 | u_short s; | |
| 37 | } short_union_t; | |
| 38 | ||
| 39 | typedef union { | |
| 40 | u_short s[2]; | |
| 41 | long l; | |
| 42 | } long_union_t; | |
| 43 | ||
| 44 | static __inline__ void | |
| 45 | reduce(int * sum) | |
| 46 | { | |
| 47 | long_union_t l_util; | |
| 48 | ||
| 49 | l_util.l = *sum; | |
| 50 | *sum = l_util.s[0] + l_util.s[1]; | |
| 51 | if (*sum > 65535) { | |
| 52 | *sum -= 65535; | |
| 53 | } | |
| 54 | return; | |
| 55 | } | |
| 56 | ||
| 57 | ||
| 58 | #include <stdio.h> | |
| 59 | ||
| 60 | unsigned short | |
| 61 | in_cksum(void * pkt, int len) | |
| 62 | { | |
| 63 | u_short * w; | |
| 64 | int sum = 0; | |
| 65 | ||
| 66 | w = (u_short *)pkt; | |
| 67 | while ((len -= 32) >= 0) { | |
| 68 | sum += w[0]; sum += w[1]; | |
| 69 | sum += w[2]; sum += w[3]; | |
| 70 | sum += w[4]; sum += w[5]; | |
| 71 | sum += w[6]; sum += w[7]; | |
| 72 | sum += w[8]; sum += w[9]; | |
| 73 | sum += w[10]; sum += w[11]; | |
| 74 | sum += w[12]; sum += w[13]; | |
| 75 | sum += w[14]; sum += w[15]; | |
| 76 | w += 16; | |
| 77 | } | |
| 78 | len += 32; | |
| 79 | while ((len -= 8) >= 0) { | |
| 80 | sum += w[0]; sum += w[1]; | |
| 81 | sum += w[2]; sum += w[3]; | |
| 82 | w += 4; | |
| 83 | } | |
| 84 | len += 8; | |
| 85 | if (len) { | |
| 86 | reduce(&sum); | |
| 87 | while ((len -= 2) >= 0) { | |
| 88 | sum += *w++; | |
| 89 | } | |
| 90 | } | |
| 91 | if (len == -1) { /* odd-length packet */ | |
| 92 | short_union_t s_util; | |
| 93 | ||
| 94 | s_util.s = 0; | |
| 95 | s_util.c[0] = *((char *)w); | |
| 96 | s_util.c[1] = 0; | |
| 97 | sum += s_util.s; | |
| 98 | } | |
| 99 | reduce(&sum); | |
| 100 | return ~sum & 0xffff; | |
| 101 | } |