2889eb8bdf
Optimize in6_cksum(), re-ordering work and limiting variable initialization, removing a bzero() for mostly re-initialized struct values, making use of the newly introduced in6_getscope(), as well as converting an if/panic to a KASSERT(). Sponsored by: The FreeBSD Foundation Sponsored by: iXsystems Reviewed by: gnn (as part of the whole) MFC After: 3 days
298 lines
8.4 KiB
C
298 lines
8.4 KiB
C
/*-
|
|
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
|
|
* All rights reserved.
|
|
*
|
|
* 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. Neither the name of the project 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 PROJECT 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 PROJECT 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.
|
|
*
|
|
* $KAME: in6_cksum.c,v 1.10 2000/12/03 00:53:59 itojun Exp $
|
|
*/
|
|
|
|
/*-
|
|
* Copyright (c) 1988, 1992, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* 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.
|
|
* 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>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/systm.h>
|
|
#include <netinet/in.h>
|
|
#include <netinet/ip6.h>
|
|
#include <netinet6/scope6_var.h>
|
|
|
|
/*
|
|
* Checksum routine for Internet Protocol family headers (Portable 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 REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; (void)ADDCARRY(sum);}
|
|
|
|
/*
|
|
* m MUST contain a contiguous IP6 header.
|
|
* off is an offset where TCP/UDP/ICMP6 header starts.
|
|
* len is a total length of a transport segment.
|
|
* (e.g. TCP header + TCP payload)
|
|
*/
|
|
int
|
|
in6_cksum(struct mbuf *m, u_int8_t nxt, u_int32_t off, u_int32_t len)
|
|
{
|
|
struct ip6_hdr *ip6;
|
|
u_int16_t *w, scope;
|
|
int byte_swapped, mlen;
|
|
int sum;
|
|
union {
|
|
u_int16_t phs[4];
|
|
struct {
|
|
u_int32_t ph_len;
|
|
u_int8_t ph_zero[3];
|
|
u_int8_t ph_nxt;
|
|
} __packed ph;
|
|
} uph;
|
|
union {
|
|
u_int8_t c[2];
|
|
u_int16_t s;
|
|
} s_util;
|
|
union {
|
|
u_int16_t s[2];
|
|
u_int32_t l;
|
|
} l_util;
|
|
|
|
/* Sanity check. */
|
|
KASSERT(m->m_pkthdr.len >= off + len, ("%s: mbuf len (%d) < off(%d)+"
|
|
"len(%d)", __func__, m->m_pkthdr.len, off, len));
|
|
|
|
/*
|
|
* First create IP6 pseudo header and calculate a summary.
|
|
*/
|
|
uph.ph.ph_len = htonl(len);
|
|
uph.ph.ph_zero[0] = uph.ph.ph_zero[1] = uph.ph.ph_zero[2] = 0;
|
|
uph.ph.ph_nxt = nxt;
|
|
|
|
/* Payload length and upper layer identifier. */
|
|
sum = uph.phs[0]; sum += uph.phs[1];
|
|
sum += uph.phs[2]; sum += uph.phs[3];
|
|
|
|
ip6 = mtod(m, struct ip6_hdr *);
|
|
|
|
/* IPv6 source address. */
|
|
scope = in6_getscope(&ip6->ip6_src);
|
|
w = (u_int16_t *)&ip6->ip6_src;
|
|
sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
|
|
sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
|
|
if (scope != 0)
|
|
sum -= scope;
|
|
|
|
/* IPv6 destination address. */
|
|
scope = in6_getscope(&ip6->ip6_dst);
|
|
w = (u_int16_t *)&ip6->ip6_dst;
|
|
sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
|
|
sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
|
|
if (scope != 0)
|
|
sum -= scope;
|
|
|
|
/*
|
|
* Secondly calculate a summary of the first mbuf excluding offset.
|
|
*/
|
|
while (off > 0) {
|
|
if (m->m_len <= off)
|
|
off -= m->m_len;
|
|
else
|
|
break;
|
|
m = m->m_next;
|
|
}
|
|
w = (u_int16_t *)(mtod(m, u_char *) + off);
|
|
mlen = m->m_len - off;
|
|
if (len < mlen)
|
|
mlen = len;
|
|
len -= mlen;
|
|
/*
|
|
* Force to even boundary.
|
|
*/
|
|
if ((1 & (long)w) && (mlen > 0)) {
|
|
REDUCE;
|
|
sum <<= 8;
|
|
s_util.c[0] = *(u_char *)w;
|
|
w = (u_int16_t *)((char *)w + 1);
|
|
mlen--;
|
|
byte_swapped = 1;
|
|
} else
|
|
byte_swapped = 0;
|
|
|
|
/*
|
|
* Unroll the loop to make overhead from
|
|
* branches &c small.
|
|
*/
|
|
while ((mlen -= 32) >= 0) {
|
|
sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
|
|
sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
|
|
sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];
|
|
sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
|
|
w += 16;
|
|
}
|
|
mlen += 32;
|
|
while ((mlen -= 8) >= 0) {
|
|
sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
|
|
w += 4;
|
|
}
|
|
mlen += 8;
|
|
if (mlen == 0 && byte_swapped == 0)
|
|
goto next;
|
|
REDUCE;
|
|
while ((mlen -= 2) >= 0) {
|
|
sum += *w++;
|
|
}
|
|
if (byte_swapped) {
|
|
REDUCE;
|
|
sum <<= 8;
|
|
byte_swapped = 0;
|
|
if (mlen == -1) {
|
|
s_util.c[1] = *(char *)w;
|
|
sum += s_util.s;
|
|
mlen = 0;
|
|
} else
|
|
mlen = -1;
|
|
} else if (mlen == -1)
|
|
s_util.c[0] = *(char *)w;
|
|
next:
|
|
m = m->m_next;
|
|
|
|
/*
|
|
* Lastly calculate a summary of the rest of mbufs.
|
|
*/
|
|
|
|
for (;m && len; m = m->m_next) {
|
|
if (m->m_len == 0)
|
|
continue;
|
|
w = mtod(m, u_int16_t *);
|
|
if (mlen == -1) {
|
|
/*
|
|
* The first byte of this mbuf is the continuation
|
|
* of a word spanning between this mbuf and the
|
|
* last mbuf.
|
|
*
|
|
* s_util.c[0] is already saved when scanning previous
|
|
* mbuf.
|
|
*/
|
|
s_util.c[1] = *(char *)w;
|
|
sum += s_util.s;
|
|
w = (u_int16_t *)((char *)w + 1);
|
|
mlen = m->m_len - 1;
|
|
len--;
|
|
} else
|
|
mlen = m->m_len;
|
|
if (len < mlen)
|
|
mlen = len;
|
|
len -= mlen;
|
|
/*
|
|
* Force to even boundary.
|
|
*/
|
|
if ((1 & (long) w) && (mlen > 0)) {
|
|
REDUCE;
|
|
sum <<= 8;
|
|
s_util.c[0] = *(u_char *)w;
|
|
w = (u_int16_t *)((char *)w + 1);
|
|
mlen--;
|
|
byte_swapped = 1;
|
|
}
|
|
/*
|
|
* Unroll the loop to make overhead from
|
|
* branches &c small.
|
|
*/
|
|
while ((mlen -= 32) >= 0) {
|
|
sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
|
|
sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
|
|
sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];
|
|
sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
|
|
w += 16;
|
|
}
|
|
mlen += 32;
|
|
while ((mlen -= 8) >= 0) {
|
|
sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
|
|
w += 4;
|
|
}
|
|
mlen += 8;
|
|
if (mlen == 0 && byte_swapped == 0)
|
|
continue;
|
|
REDUCE;
|
|
while ((mlen -= 2) >= 0) {
|
|
sum += *w++;
|
|
}
|
|
if (byte_swapped) {
|
|
REDUCE;
|
|
sum <<= 8;
|
|
byte_swapped = 0;
|
|
if (mlen == -1) {
|
|
s_util.c[1] = *(char *)w;
|
|
sum += s_util.s;
|
|
mlen = 0;
|
|
} else
|
|
mlen = -1;
|
|
} else if (mlen == -1)
|
|
s_util.c[0] = *(char *)w;
|
|
}
|
|
if (len)
|
|
panic("in6_cksum: out of data");
|
|
if (mlen == -1) {
|
|
/* The last mbuf has odd # of bytes. Follow the
|
|
standard (the odd byte may be shifted left by 8 bits
|
|
or not as determined by endian-ness of the machine) */
|
|
s_util.c[1] = 0;
|
|
sum += s_util.s;
|
|
}
|
|
REDUCE;
|
|
return (~sum & 0xffff);
|
|
}
|