199040Sbenno/* $FreeBSD$ */ 299040Sbenno/* $NetBSD: in_cksum.c,v 1.7 1997/09/02 13:18:15 thorpej Exp $ */ 399040Sbenno 4139825Simp/*- 599040Sbenno * Copyright (c) 1988, 1992, 1993 699040Sbenno * The Regents of the University of California. All rights reserved. 799040Sbenno * Copyright (c) 1996 899040Sbenno * Matt Thomas <matt@3am-software.com> 999040Sbenno * 1099040Sbenno * Redistribution and use in source and binary forms, with or without 1199040Sbenno * modification, are permitted provided that the following conditions 1299040Sbenno * are met: 1399040Sbenno * 1. Redistributions of source code must retain the above copyright 1499040Sbenno * notice, this list of conditions and the following disclaimer. 1599040Sbenno * 2. Redistributions in binary form must reproduce the above copyright 1699040Sbenno * notice, this list of conditions and the following disclaimer in the 1799040Sbenno * documentation and/or other materials provided with the distribution. 1899040Sbenno * 3. All advertising materials mentioning features or use of this software 1999040Sbenno * must display the following acknowledgement: 2099040Sbenno * This product includes software developed by the University of 2199040Sbenno * California, Berkeley and its contributors. 2299040Sbenno * 4. Neither the name of the University nor the names of its contributors 2399040Sbenno * may be used to endorse or promote products derived from this software 2499040Sbenno * without specific prior written permission. 2599040Sbenno * 2699040Sbenno * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2799040Sbenno * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2899040Sbenno * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2999040Sbenno * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 3099040Sbenno * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 3199040Sbenno * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 3299040Sbenno * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 3399040Sbenno * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 3499040Sbenno * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3599040Sbenno * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3699040Sbenno * SUCH DAMAGE. 3799040Sbenno * 3899040Sbenno * @(#)in_cksum.c 8.1 (Berkeley) 6/10/93 3999040Sbenno */ 4099040Sbenno 4199040Sbenno#include <sys/cdefs.h> /* RCS ID & Copyright macro defns */ 4299040Sbenno 4399040Sbenno#include <sys/param.h> 4499040Sbenno#include <sys/mbuf.h> 4599040Sbenno#include <sys/systm.h> 4699040Sbenno#include <netinet/in_systm.h> 4799040Sbenno#include <netinet/in.h> 4899040Sbenno#include <netinet/ip.h> 4999040Sbenno#include <machine/in_cksum.h> 5099040Sbenno 5199040Sbenno/* 5299040Sbenno * Checksum routine for Internet Protocol family headers 5399040Sbenno * (Portable Alpha version). 5499040Sbenno * 5599040Sbenno * This routine is very heavily used in the network 5699040Sbenno * code and should be modified for each CPU to be as fast as possible. 5799040Sbenno */ 5899040Sbenno 5999040Sbenno#define ADDCARRY(x) (x > 65535 ? x -= 65535 : x) 6099040Sbenno#define REDUCE32 \ 6199040Sbenno { \ 6299040Sbenno q_util.q = sum; \ 6399040Sbenno sum = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3]; \ 6499040Sbenno } 6599040Sbenno#define REDUCE16 \ 6699040Sbenno { \ 6799040Sbenno q_util.q = sum; \ 6899040Sbenno l_util.l = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3]; \ 6999040Sbenno sum = l_util.s[0] + l_util.s[1]; \ 7099040Sbenno ADDCARRY(sum); \ 7199040Sbenno } 7299040Sbenno 7399040Sbennostatic const u_int32_t in_masks[] = { 7499040Sbenno#if 0 7599040Sbenno /*0 bytes*/ /*1 byte*/ /*2 bytes*/ /*3 bytes*/ 7699040Sbenno 0x00000000, 0x000000FF, 0x0000FFFF, 0x00FFFFFF, /* offset 0 */ 7799040Sbenno 0x00000000, 0x0000FF00, 0x00FFFF00, 0xFFFFFF00, /* offset 1 */ 7899040Sbenno 0x00000000, 0x00FF0000, 0xFFFF0000, 0xFFFF0000, /* offset 2 */ 7999040Sbenno 0x00000000, 0xFF000000, 0xFF000000, 0xFF000000, /* offset 3 */ 8099040Sbenno#else 8199040Sbenno /*0 bytes*/ /*1 byte*/ /*2 bytes*/ /*3 bytes*/ 8299040Sbenno 0x00000000, 0xFF000000, 0xFFFF0000, 0xFFFFFF00, /* offset 0 */ 8399040Sbenno 0x00000000, 0x00FF0000, 0x00FFFF00, 0x00FFFFFF, /* offset 1 */ 8499040Sbenno 0x00000000, 0x0000FF00, 0x0000FFFF, 0x0000FFFF, /* offset 2 */ 8599040Sbenno 0x00000000, 0x000000FF, 0x000000FF, 0x000000FF, /* offset 3 */ 8699040Sbenno#endif 8799040Sbenno}; 8899040Sbenno 8999040Sbennounion l_util { 9099040Sbenno u_int16_t s[2]; 9199040Sbenno u_int32_t l; 9299040Sbenno}; 9399040Sbennounion q_util { 9499040Sbenno u_int16_t s[4]; 9599040Sbenno u_int32_t l[2]; 9699040Sbenno u_int64_t q; 9799040Sbenno}; 9899040Sbenno 9999040Sbennostatic u_int64_t 10099040Sbennoin_cksumdata(const void *buf, int len) 10199040Sbenno{ 10299040Sbenno const u_int32_t *lw = (const u_int32_t *) buf; 10399040Sbenno u_int64_t sum = 0; 10499040Sbenno u_int64_t prefilled; 10599040Sbenno int offset; 10699040Sbenno union q_util q_util; 10799040Sbenno 10899040Sbenno if ((3 & (long) lw) == 0 && len == 20) { 10999040Sbenno sum = (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3] + lw[4]; 11099040Sbenno REDUCE32; 11199040Sbenno return sum; 11299040Sbenno } 11399040Sbenno 11499040Sbenno if ((offset = 3 & (long) lw) != 0) { 11599040Sbenno const u_int32_t *masks = in_masks + (offset << 2); 11699040Sbenno lw = (u_int32_t *) (((long) lw) - offset); 11799040Sbenno sum = *lw++ & masks[len >= 3 ? 3 : len]; 11899040Sbenno len -= 4 - offset; 11999040Sbenno if (len <= 0) { 12099040Sbenno REDUCE32; 12199040Sbenno return sum; 12299040Sbenno } 12399040Sbenno } 12499040Sbenno#if 0 12599040Sbenno /* 12699040Sbenno * Force to cache line boundary. 12799040Sbenno */ 12899040Sbenno offset = 32 - (0x1f & (long) lw); 12999040Sbenno if (offset < 32 && len > offset) { 13099040Sbenno len -= offset; 13199040Sbenno if (4 & offset) { 13299040Sbenno sum += (u_int64_t) lw[0]; 13399040Sbenno lw += 1; 13499040Sbenno } 13599040Sbenno if (8 & offset) { 13699040Sbenno sum += (u_int64_t) lw[0] + lw[1]; 13799040Sbenno lw += 2; 13899040Sbenno } 13999040Sbenno if (16 & offset) { 14099040Sbenno sum += (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3]; 14199040Sbenno lw += 4; 14299040Sbenno } 14399040Sbenno } 14499040Sbenno#endif 14599040Sbenno /* 14699040Sbenno * access prefilling to start load of next cache line. 14799040Sbenno * then add current cache line 14899040Sbenno * save result of prefilling for loop iteration. 14999040Sbenno */ 15099040Sbenno prefilled = lw[0]; 15199040Sbenno while ((len -= 32) >= 4) { 15299040Sbenno u_int64_t prefilling = lw[8]; 15399040Sbenno sum += prefilled + lw[1] + lw[2] + lw[3] 15499040Sbenno + lw[4] + lw[5] + lw[6] + lw[7]; 15599040Sbenno lw += 8; 15699040Sbenno prefilled = prefilling; 15799040Sbenno } 15899040Sbenno if (len >= 0) { 15999040Sbenno sum += prefilled + lw[1] + lw[2] + lw[3] 16099040Sbenno + lw[4] + lw[5] + lw[6] + lw[7]; 16199040Sbenno lw += 8; 16299040Sbenno } else { 16399040Sbenno len += 32; 16499040Sbenno } 16599040Sbenno while ((len -= 16) >= 0) { 16699040Sbenno sum += (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3]; 16799040Sbenno lw += 4; 16899040Sbenno } 16999040Sbenno len += 16; 17099040Sbenno while ((len -= 4) >= 0) { 17199040Sbenno sum += (u_int64_t) *lw++; 17299040Sbenno } 17399040Sbenno len += 4; 17499040Sbenno if (len > 0) 17599040Sbenno sum += (u_int64_t) (in_masks[len] & *lw); 17699040Sbenno REDUCE32; 17799040Sbenno return sum; 17899040Sbenno} 17999040Sbenno 18099040Sbennou_short 18199040Sbennoin_addword(u_short a, u_short b) 18299040Sbenno{ 18399040Sbenno u_int64_t sum = a + b; 18499040Sbenno 18599040Sbenno ADDCARRY(sum); 18699040Sbenno return (sum); 18799040Sbenno} 18899040Sbenno 18999040Sbennou_short 19099040Sbennoin_pseudo(u_int32_t a, u_int32_t b, u_int32_t c) 19199040Sbenno{ 19299040Sbenno u_int64_t sum; 19399040Sbenno union q_util q_util; 19499040Sbenno union l_util l_util; 19599040Sbenno 19699040Sbenno sum = (u_int64_t) a + b + c; 19799040Sbenno REDUCE16; 19899040Sbenno return (sum); 19999040Sbenno} 20099040Sbenno 20199040Sbennou_short 20299040Sbennoin_cksum_skip(struct mbuf *m, int len, int skip) 20399040Sbenno{ 20499040Sbenno u_int64_t sum = 0; 20599040Sbenno int mlen = 0; 20699040Sbenno int clen = 0; 20799040Sbenno caddr_t addr; 20899040Sbenno union q_util q_util; 20999040Sbenno union l_util l_util; 21099040Sbenno 21199040Sbenno len -= skip; 21299040Sbenno for (; skip && m; m = m->m_next) { 21399040Sbenno if (m->m_len > skip) { 21499040Sbenno mlen = m->m_len - skip; 21599040Sbenno addr = mtod(m, caddr_t) + skip; 21699040Sbenno goto skip_start; 21799040Sbenno } else { 21899040Sbenno skip -= m->m_len; 21999040Sbenno } 22099040Sbenno } 22199040Sbenno 22299040Sbenno for (; m && len; m = m->m_next) { 22399040Sbenno if (m->m_len == 0) 22499040Sbenno continue; 22599040Sbenno mlen = m->m_len; 22699040Sbenno addr = mtod(m, caddr_t); 22799040Sbennoskip_start: 22899040Sbenno if (len < mlen) 22999040Sbenno mlen = len; 23099040Sbenno 231209975Snwhitehorn if ((clen ^ (long) addr) & 1) 23299040Sbenno sum += in_cksumdata(addr, mlen) << 8; 23399040Sbenno else 23499040Sbenno sum += in_cksumdata(addr, mlen); 23599040Sbenno 23699040Sbenno clen += mlen; 23799040Sbenno len -= mlen; 23899040Sbenno } 23999040Sbenno REDUCE16; 24099040Sbenno return (~sum & 0xffff); 24199040Sbenno} 24299040Sbenno 24399040Sbennou_int in_cksum_hdr(const struct ip *ip) 24499040Sbenno{ 24599040Sbenno u_int64_t sum = in_cksumdata(ip, sizeof(struct ip)); 24699040Sbenno union q_util q_util; 24799040Sbenno union l_util l_util; 24899040Sbenno REDUCE16; 24999040Sbenno return (~sum & 0xffff); 25099040Sbenno} 251