1*7c478bd9Sstevel@tonic-gate /* 2*7c478bd9Sstevel@tonic-gate * CDDL HEADER START 3*7c478bd9Sstevel@tonic-gate * 4*7c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*7c478bd9Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only 6*7c478bd9Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance 7*7c478bd9Sstevel@tonic-gate * with the License. 8*7c478bd9Sstevel@tonic-gate * 9*7c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10*7c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 11*7c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions 12*7c478bd9Sstevel@tonic-gate * and limitations under the License. 13*7c478bd9Sstevel@tonic-gate * 14*7c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 15*7c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16*7c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 17*7c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 18*7c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 19*7c478bd9Sstevel@tonic-gate * 20*7c478bd9Sstevel@tonic-gate * CDDL HEADER END 21*7c478bd9Sstevel@tonic-gate */ 22*7c478bd9Sstevel@tonic-gate /* 23*7c478bd9Sstevel@tonic-gate * Copyright (c) 1996-2001 by Sun Microsystems, Inc. 24*7c478bd9Sstevel@tonic-gate * All rights reserved. 25*7c478bd9Sstevel@tonic-gate */ 26*7c478bd9Sstevel@tonic-gate 27*7c478bd9Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 28*7c478bd9Sstevel@tonic-gate 29*7c478bd9Sstevel@tonic-gate #include <sys/types.h> 30*7c478bd9Sstevel@tonic-gate #include <strings.h> 31*7c478bd9Sstevel@tonic-gate #include <netinet/in.h> 32*7c478bd9Sstevel@tonic-gate #include "v4_sum_impl.h" 33*7c478bd9Sstevel@tonic-gate 34*7c478bd9Sstevel@tonic-gate /* 35*7c478bd9Sstevel@tonic-gate * RFC 768 pseudo header. Used in calculating UDP checksums. 36*7c478bd9Sstevel@tonic-gate */ 37*7c478bd9Sstevel@tonic-gate struct pseudo_udp { 38*7c478bd9Sstevel@tonic-gate struct in_addr src; 39*7c478bd9Sstevel@tonic-gate struct in_addr dst; 40*7c478bd9Sstevel@tonic-gate uint8_t notused; /* always zero */ 41*7c478bd9Sstevel@tonic-gate uint8_t proto; /* protocol used */ 42*7c478bd9Sstevel@tonic-gate uint16_t len; /* UDP len */ 43*7c478bd9Sstevel@tonic-gate }; 44*7c478bd9Sstevel@tonic-gate 45*7c478bd9Sstevel@tonic-gate /* 46*7c478bd9Sstevel@tonic-gate * One's complement checksum of pseudo header, udp header, and data. 47*7c478bd9Sstevel@tonic-gate * Must be MT SAFE. 48*7c478bd9Sstevel@tonic-gate */ 49*7c478bd9Sstevel@tonic-gate uint16_t 50*7c478bd9Sstevel@tonic-gate udp_chksum(struct udphdr *udph, const struct in_addr *src, 51*7c478bd9Sstevel@tonic-gate const struct in_addr *dst, uint8_t proto) 52*7c478bd9Sstevel@tonic-gate { 53*7c478bd9Sstevel@tonic-gate struct pseudo_udp ck; 54*7c478bd9Sstevel@tonic-gate uint16_t *end_pseudo_hdr = (uint16_t *)(&ck + 1); 55*7c478bd9Sstevel@tonic-gate uint16_t *sp = (uint16_t *)&ck; 56*7c478bd9Sstevel@tonic-gate uint_t sum = 0; 57*7c478bd9Sstevel@tonic-gate uint16_t cnt; 58*7c478bd9Sstevel@tonic-gate 59*7c478bd9Sstevel@tonic-gate /* 60*7c478bd9Sstevel@tonic-gate * Start on the pseudo header. Note that pseudo_udp already takes 61*7c478bd9Sstevel@tonic-gate * acount for the udphdr... 62*7c478bd9Sstevel@tonic-gate */ 63*7c478bd9Sstevel@tonic-gate 64*7c478bd9Sstevel@tonic-gate bzero(&ck, sizeof (ck)); 65*7c478bd9Sstevel@tonic-gate 66*7c478bd9Sstevel@tonic-gate /* struct copies */ 67*7c478bd9Sstevel@tonic-gate ck.src = *src; 68*7c478bd9Sstevel@tonic-gate ck.dst = *dst; 69*7c478bd9Sstevel@tonic-gate ck.len = udph->uh_ulen; 70*7c478bd9Sstevel@tonic-gate ck.proto = proto; 71*7c478bd9Sstevel@tonic-gate 72*7c478bd9Sstevel@tonic-gate /* 73*7c478bd9Sstevel@tonic-gate * If the packet is an odd length, zero the pad byte for checksum 74*7c478bd9Sstevel@tonic-gate * purposes [doesn't hurt data] 75*7c478bd9Sstevel@tonic-gate */ 76*7c478bd9Sstevel@tonic-gate 77*7c478bd9Sstevel@tonic-gate cnt = ntohs(ck.len) + sizeof (ck); 78*7c478bd9Sstevel@tonic-gate if (cnt & 1) { 79*7c478bd9Sstevel@tonic-gate ((caddr_t)udph)[ntohs(udph->uh_ulen)] = '\0'; 80*7c478bd9Sstevel@tonic-gate cnt++; /* make even */ 81*7c478bd9Sstevel@tonic-gate } 82*7c478bd9Sstevel@tonic-gate 83*7c478bd9Sstevel@tonic-gate for (cnt >>= 1; cnt != 0; cnt--) { 84*7c478bd9Sstevel@tonic-gate 85*7c478bd9Sstevel@tonic-gate sum += *sp++; 86*7c478bd9Sstevel@tonic-gate if (sum >= BIT_WRAP) { 87*7c478bd9Sstevel@tonic-gate /* Wrap carries into low bit */ 88*7c478bd9Sstevel@tonic-gate sum -= BIT_WRAP; 89*7c478bd9Sstevel@tonic-gate sum++; 90*7c478bd9Sstevel@tonic-gate } 91*7c478bd9Sstevel@tonic-gate 92*7c478bd9Sstevel@tonic-gate /* 93*7c478bd9Sstevel@tonic-gate * If we've finished checking the pseudo-header, move 94*7c478bd9Sstevel@tonic-gate * onto the udp header and data. 95*7c478bd9Sstevel@tonic-gate */ 96*7c478bd9Sstevel@tonic-gate 97*7c478bd9Sstevel@tonic-gate if (sp == end_pseudo_hdr) 98*7c478bd9Sstevel@tonic-gate sp = (uint16_t *)udph; 99*7c478bd9Sstevel@tonic-gate } 100*7c478bd9Sstevel@tonic-gate 101*7c478bd9Sstevel@tonic-gate return (~sum == 0 ? ~0 : ~sum); 102*7c478bd9Sstevel@tonic-gate } 103