242 lines
6.2 KiB
C
242 lines
6.2 KiB
C
/* $FreeBSD$ */
|
|
/* $NetBSD: in_cksum.c,v 1.7 1997/09/02 13:18:15 thorpej Exp $ */
|
|
|
|
/*
|
|
* Copyright (c) 1988, 1992, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
* Copyright (c) 1996
|
|
* Matt Thomas <matt@3am-software.com>
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* @(#)in_cksum.c 8.1 (Berkeley) 6/10/93
|
|
*/
|
|
|
|
#include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/systm.h>
|
|
#include <netinet/in_systm.h>
|
|
#include <netinet/in.h>
|
|
#include <netinet/ip.h>
|
|
#include <machine/in_cksum.h>
|
|
|
|
/*
|
|
* Checksum routine for Internet Protocol family headers
|
|
* (Portable Alpha version).
|
|
*
|
|
* This routine is very heavily used in the network
|
|
* code and should be modified for each CPU to be as fast as possible.
|
|
*/
|
|
|
|
#define ADDCARRY(x) (x > 65535 ? x -= 65535 : x)
|
|
#define REDUCE32 \
|
|
{ \
|
|
q_util.q = sum; \
|
|
sum = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3]; \
|
|
}
|
|
#define REDUCE16 \
|
|
{ \
|
|
q_util.q = sum; \
|
|
l_util.l = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3]; \
|
|
sum = l_util.s[0] + l_util.s[1]; \
|
|
ADDCARRY(sum); \
|
|
}
|
|
|
|
static const u_int32_t in_masks[] = {
|
|
/*0 bytes*/ /*1 byte*/ /*2 bytes*/ /*3 bytes*/
|
|
0x00000000, 0x000000FF, 0x0000FFFF, 0x00FFFFFF, /* offset 0 */
|
|
0x00000000, 0x0000FF00, 0x00FFFF00, 0xFFFFFF00, /* offset 1 */
|
|
0x00000000, 0x00FF0000, 0xFFFF0000, 0xFFFF0000, /* offset 2 */
|
|
0x00000000, 0xFF000000, 0xFF000000, 0xFF000000, /* offset 3 */
|
|
};
|
|
|
|
union l_util {
|
|
u_int16_t s[2];
|
|
u_int32_t l;
|
|
};
|
|
union q_util {
|
|
u_int16_t s[4];
|
|
u_int32_t l[2];
|
|
u_int64_t q;
|
|
};
|
|
|
|
static u_int64_t
|
|
in_cksumdata(const void *buf, size_t len)
|
|
{
|
|
const u_int32_t *lw = (const u_int32_t *) buf;
|
|
u_int64_t sum = 0;
|
|
u_int64_t prefilled;
|
|
int offset;
|
|
union q_util q_util;
|
|
|
|
if ((3 & (long) lw) == 0 && len == 20) {
|
|
sum = (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3] + lw[4];
|
|
REDUCE32;
|
|
return sum;
|
|
}
|
|
|
|
if ((offset = 3 & (long) lw) != 0) {
|
|
const u_int32_t *masks = in_masks + (offset << 2);
|
|
lw = (u_int32_t *) (((long) lw) - offset);
|
|
sum = *lw++ & masks[len >= 3 ? 3 : len];
|
|
len -= 4 - offset;
|
|
if (len <= 0) {
|
|
REDUCE32;
|
|
return sum;
|
|
}
|
|
}
|
|
#if 0
|
|
/*
|
|
* Force to cache line boundary.
|
|
*/
|
|
offset = 32 - (0x1f & (long) lw);
|
|
if (offset < 32 && len > offset) {
|
|
len -= offset;
|
|
if (4 & offset) {
|
|
sum += (u_int64_t) lw[0];
|
|
lw += 1;
|
|
}
|
|
if (8 & offset) {
|
|
sum += (u_int64_t) lw[0] + lw[1];
|
|
lw += 2;
|
|
}
|
|
if (16 & offset) {
|
|
sum += (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3];
|
|
lw += 4;
|
|
}
|
|
}
|
|
#endif
|
|
/*
|
|
* access prefilling to start load of next cache line.
|
|
* then add current cache line
|
|
* save result of prefilling for loop iteration.
|
|
*/
|
|
prefilled = lw[0];
|
|
while ((len -= 32) >= 4) {
|
|
u_int64_t prefilling = lw[8];
|
|
sum += prefilled + lw[1] + lw[2] + lw[3]
|
|
+ lw[4] + lw[5] + lw[6] + lw[7];
|
|
lw += 8;
|
|
prefilled = prefilling;
|
|
}
|
|
if (len >= 0) {
|
|
sum += prefilled + lw[1] + lw[2] + lw[3]
|
|
+ lw[4] + lw[5] + lw[6] + lw[7];
|
|
lw += 8;
|
|
} else {
|
|
len += 32;
|
|
}
|
|
while ((len -= 16) >= 0) {
|
|
sum += (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3];
|
|
lw += 4;
|
|
}
|
|
len += 16;
|
|
while ((len -= 4) >= 0) {
|
|
sum += (u_int64_t) *lw++;
|
|
}
|
|
len += 4;
|
|
if (len > 0)
|
|
sum += (u_int64_t) (in_masks[len] & *lw);
|
|
REDUCE32;
|
|
return sum;
|
|
}
|
|
|
|
u_short
|
|
in_addword(u_short a, u_short b)
|
|
{
|
|
u_int64_t sum = a + b;
|
|
|
|
ADDCARRY(sum);
|
|
return (sum);
|
|
}
|
|
|
|
u_short
|
|
in_pseudo(u_int32_t a, u_int32_t b, u_int32_t c)
|
|
{
|
|
u_int64_t sum;
|
|
union q_util q_util;
|
|
union l_util l_util;
|
|
|
|
sum = (u_int64_t) a + b + c;
|
|
REDUCE16;
|
|
return (sum);
|
|
}
|
|
|
|
u_short
|
|
in_cksum_skip(struct mbuf *m, int len, int skip)
|
|
{
|
|
u_int64_t sum = 0;
|
|
int mlen = 0;
|
|
int clen = 0;
|
|
caddr_t addr;
|
|
union q_util q_util;
|
|
union l_util l_util;
|
|
|
|
len -= skip;
|
|
for (; skip && m; m = m->m_next) {
|
|
if (m->m_len > skip) {
|
|
mlen = m->m_len - skip;
|
|
addr = mtod(m, caddr_t) + skip;
|
|
goto skip_start;
|
|
} else {
|
|
skip -= m->m_len;
|
|
}
|
|
}
|
|
|
|
for (; m && len; m = m->m_next) {
|
|
if (m->m_len == 0)
|
|
continue;
|
|
mlen = m->m_len;
|
|
addr = mtod(m, caddr_t);
|
|
skip_start:
|
|
if (len < mlen)
|
|
mlen = len;
|
|
if ((clen ^ (long) addr) & 1)
|
|
sum += in_cksumdata(addr, mlen) << 8;
|
|
else
|
|
sum += in_cksumdata(addr, mlen);
|
|
|
|
clen += mlen;
|
|
len -= mlen;
|
|
}
|
|
REDUCE16;
|
|
return (~sum & 0xffff);
|
|
}
|
|
|
|
u_int in_cksum_hdr(const struct ip *ip)
|
|
{
|
|
u_int64_t sum = in_cksumdata(ip, sizeof(struct ip));
|
|
union q_util q_util;
|
|
union l_util l_util;
|
|
REDUCE16;
|
|
return (~sum & 0xffff);
|
|
}
|