1281494Sandrew/* $NetBSD: in_cksum.c,v 1.7 1997/09/02 13:18:15 thorpej Exp $ */ 2281494Sandrew 3281494Sandrew/*- 4281494Sandrew * Copyright (c) 1988, 1992, 1993 5281494Sandrew * The Regents of the University of California. All rights reserved. 6281494Sandrew * Copyright (c) 1996 7281494Sandrew * Matt Thomas <matt@3am-software.com> 8281494Sandrew * 9281494Sandrew * Redistribution and use in source and binary forms, with or without 10281494Sandrew * modification, are permitted provided that the following conditions 11281494Sandrew * are met: 12281494Sandrew * 1. Redistributions of source code must retain the above copyright 13281494Sandrew * notice, this list of conditions and the following disclaimer. 14281494Sandrew * 2. Redistributions in binary form must reproduce the above copyright 15281494Sandrew * notice, this list of conditions and the following disclaimer in the 16281494Sandrew * documentation and/or other materials provided with the distribution. 17281494Sandrew * 3. All advertising materials mentioning features or use of this software 18281494Sandrew * must display the following acknowledgement: 19281494Sandrew * This product includes software developed by the University of 20281494Sandrew * California, Berkeley and its contributors. 21281494Sandrew * 4. Neither the name of the University nor the names of its contributors 22281494Sandrew * may be used to endorse or promote products derived from this software 23281494Sandrew * without specific prior written permission. 24281494Sandrew * 25281494Sandrew * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26281494Sandrew * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27281494Sandrew * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28281494Sandrew * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29281494Sandrew * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30281494Sandrew * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31281494Sandrew * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32281494Sandrew * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33281494Sandrew * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34281494Sandrew * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35281494Sandrew * SUCH DAMAGE. 36281494Sandrew * 37281494Sandrew * @(#)in_cksum.c 8.1 (Berkeley) 6/10/93 38281494Sandrew */ 39281494Sandrew 40281494Sandrew#include <sys/cdefs.h> /* RCS ID & Copyright macro defns */ 41281494Sandrew__FBSDID("$FreeBSD$"); 42281494Sandrew 43281494Sandrew#include <sys/param.h> 44281494Sandrew#include <sys/mbuf.h> 45281494Sandrew#include <sys/systm.h> 46281494Sandrew#include <netinet/in_systm.h> 47281494Sandrew#include <netinet/in.h> 48281494Sandrew#include <netinet/ip.h> 49281494Sandrew#include <machine/in_cksum.h> 50281494Sandrew 51281494Sandrew/* 52281494Sandrew * Checksum routine for Internet Protocol family headers 53281494Sandrew * (Portable Alpha version). 54281494Sandrew * 55281494Sandrew * This routine is very heavily used in the network 56281494Sandrew * code and should be modified for each CPU to be as fast as possible. 57281494Sandrew */ 58281494Sandrew 59281494Sandrew#define ADDCARRY(x) (x > 65535 ? x -= 65535 : x) 60281494Sandrew#define REDUCE32 \ 61281494Sandrew { \ 62281494Sandrew q_util.q = sum; \ 63281494Sandrew sum = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3]; \ 64281494Sandrew } 65281494Sandrew#define REDUCE16 \ 66281494Sandrew { \ 67281494Sandrew q_util.q = sum; \ 68281494Sandrew l_util.l = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3]; \ 69281494Sandrew sum = l_util.s[0] + l_util.s[1]; \ 70281494Sandrew ADDCARRY(sum); \ 71281494Sandrew } 72281494Sandrew 73281494Sandrewstatic const u_int32_t in_masks[] = { 74281494Sandrew /*0 bytes*/ /*1 byte*/ /*2 bytes*/ /*3 bytes*/ 75281494Sandrew 0x00000000, 0x000000FF, 0x0000FFFF, 0x00FFFFFF, /* offset 0 */ 76281494Sandrew 0x00000000, 0x0000FF00, 0x00FFFF00, 0xFFFFFF00, /* offset 1 */ 77281494Sandrew 0x00000000, 0x00FF0000, 0xFFFF0000, 0xFFFF0000, /* offset 2 */ 78281494Sandrew 0x00000000, 0xFF000000, 0xFF000000, 0xFF000000, /* offset 3 */ 79281494Sandrew}; 80281494Sandrew 81281494Sandrewunion l_util { 82281494Sandrew u_int16_t s[2]; 83281494Sandrew u_int32_t l; 84281494Sandrew}; 85281494Sandrewunion q_util { 86281494Sandrew u_int16_t s[4]; 87281494Sandrew u_int32_t l[2]; 88281494Sandrew u_int64_t q; 89281494Sandrew}; 90281494Sandrew 91281494Sandrewstatic u_int64_t 92281494Sandrewin_cksumdata(const void *buf, int len) 93281494Sandrew{ 94281494Sandrew const u_int32_t *lw = (const u_int32_t *) buf; 95281494Sandrew u_int64_t sum = 0; 96281494Sandrew u_int64_t prefilled; 97281494Sandrew int offset; 98281494Sandrew union q_util q_util; 99281494Sandrew 100281494Sandrew if ((3 & (long) lw) == 0 && len == 20) { 101281494Sandrew sum = (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3] + lw[4]; 102281494Sandrew REDUCE32; 103281494Sandrew return sum; 104281494Sandrew } 105281494Sandrew 106281494Sandrew if ((offset = 3 & (long) lw) != 0) { 107281494Sandrew const u_int32_t *masks = in_masks + (offset << 2); 108281494Sandrew lw = (u_int32_t *) (((long) lw) - offset); 109281494Sandrew sum = *lw++ & masks[len >= 3 ? 3 : len]; 110281494Sandrew len -= 4 - offset; 111281494Sandrew if (len <= 0) { 112281494Sandrew REDUCE32; 113281494Sandrew return sum; 114281494Sandrew } 115281494Sandrew } 116281494Sandrew#if 0 117281494Sandrew /* 118281494Sandrew * Force to cache line boundary. 119281494Sandrew */ 120281494Sandrew offset = 32 - (0x1f & (long) lw); 121281494Sandrew if (offset < 32 && len > offset) { 122281494Sandrew len -= offset; 123281494Sandrew if (4 & offset) { 124281494Sandrew sum += (u_int64_t) lw[0]; 125281494Sandrew lw += 1; 126281494Sandrew } 127281494Sandrew if (8 & offset) { 128281494Sandrew sum += (u_int64_t) lw[0] + lw[1]; 129281494Sandrew lw += 2; 130281494Sandrew } 131281494Sandrew if (16 & offset) { 132281494Sandrew sum += (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3]; 133281494Sandrew lw += 4; 134281494Sandrew } 135281494Sandrew } 136281494Sandrew#endif 137281494Sandrew /* 138281494Sandrew * access prefilling to start load of next cache line. 139281494Sandrew * then add current cache line 140281494Sandrew * save result of prefilling for loop iteration. 141281494Sandrew */ 142281494Sandrew prefilled = lw[0]; 143281494Sandrew while ((len -= 32) >= 4) { 144281494Sandrew u_int64_t prefilling = lw[8]; 145281494Sandrew sum += prefilled + lw[1] + lw[2] + lw[3] 146281494Sandrew + lw[4] + lw[5] + lw[6] + lw[7]; 147281494Sandrew lw += 8; 148281494Sandrew prefilled = prefilling; 149281494Sandrew } 150281494Sandrew if (len >= 0) { 151281494Sandrew sum += prefilled + lw[1] + lw[2] + lw[3] 152281494Sandrew + lw[4] + lw[5] + lw[6] + lw[7]; 153281494Sandrew lw += 8; 154281494Sandrew } else { 155281494Sandrew len += 32; 156281494Sandrew } 157281494Sandrew while ((len -= 16) >= 0) { 158281494Sandrew sum += (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3]; 159281494Sandrew lw += 4; 160281494Sandrew } 161281494Sandrew len += 16; 162281494Sandrew while ((len -= 4) >= 0) { 163281494Sandrew sum += (u_int64_t) *lw++; 164281494Sandrew } 165281494Sandrew len += 4; 166281494Sandrew if (len > 0) 167281494Sandrew sum += (u_int64_t) (in_masks[len] & *lw); 168281494Sandrew REDUCE32; 169281494Sandrew return sum; 170281494Sandrew} 171281494Sandrew 172281494Sandrewu_short 173281494Sandrewin_addword(u_short a, u_short b) 174281494Sandrew{ 175281494Sandrew u_int64_t sum = a + b; 176281494Sandrew 177281494Sandrew ADDCARRY(sum); 178281494Sandrew return (sum); 179281494Sandrew} 180281494Sandrew 181281494Sandrewu_short 182281494Sandrewin_pseudo(u_int32_t a, u_int32_t b, u_int32_t c) 183281494Sandrew{ 184281494Sandrew u_int64_t sum; 185281494Sandrew union q_util q_util; 186281494Sandrew union l_util l_util; 187281494Sandrew 188281494Sandrew sum = (u_int64_t) a + b + c; 189281494Sandrew REDUCE16; 190281494Sandrew return (sum); 191281494Sandrew} 192281494Sandrew 193281494Sandrewu_short 194281494Sandrewin_cksum_skip(struct mbuf *m, int len, int skip) 195281494Sandrew{ 196281494Sandrew u_int64_t sum = 0; 197281494Sandrew int mlen = 0; 198281494Sandrew int clen = 0; 199281494Sandrew caddr_t addr; 200281494Sandrew union q_util q_util; 201281494Sandrew union l_util l_util; 202281494Sandrew 203281494Sandrew len -= skip; 204281494Sandrew for (; skip && m; m = m->m_next) { 205281494Sandrew if (m->m_len > skip) { 206281494Sandrew mlen = m->m_len - skip; 207281494Sandrew addr = mtod(m, caddr_t) + skip; 208281494Sandrew goto skip_start; 209281494Sandrew } else { 210281494Sandrew skip -= m->m_len; 211281494Sandrew } 212281494Sandrew } 213281494Sandrew 214281494Sandrew for (; m && len; m = m->m_next) { 215281494Sandrew if (m->m_len == 0) 216281494Sandrew continue; 217281494Sandrew mlen = m->m_len; 218281494Sandrew addr = mtod(m, caddr_t); 219281494Sandrewskip_start: 220281494Sandrew if (len < mlen) 221281494Sandrew mlen = len; 222281494Sandrew if ((clen ^ (long) addr) & 1) 223281494Sandrew sum += in_cksumdata(addr, mlen) << 8; 224281494Sandrew else 225281494Sandrew sum += in_cksumdata(addr, mlen); 226281494Sandrew 227281494Sandrew clen += mlen; 228281494Sandrew len -= mlen; 229281494Sandrew } 230281494Sandrew REDUCE16; 231281494Sandrew return (~sum & 0xffff); 232281494Sandrew} 233281494Sandrew 234281494Sandrewu_int in_cksum_hdr(const struct ip *ip) 235281494Sandrew{ 236281494Sandrew u_int64_t sum = in_cksumdata(ip, sizeof(struct ip)); 237281494Sandrew union q_util q_util; 238281494Sandrew union l_util l_util; 239281494Sandrew REDUCE16; 240281494Sandrew return (~sum & 0xffff); 241281494Sandrew} 242