1
0
mirror of https://git.FreeBSD.org/src.git synced 2024-11-28 08:02:54 +00:00
freebsd/sys/netinet6/in6_cksum.c
Pedro F. Giffuni 51369649b0 sys: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:43:44 +00:00

368 lines
10 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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.
* 3. 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);}
static int
_in6_cksum_pseudo(struct ip6_hdr *ip6, uint32_t len, uint8_t nxt, uint16_t csum)
{
int sum;
uint16_t scope, *w;
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;
sum = csum;
/*
* 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];
/* 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;
return (sum);
}
int
in6_cksum_pseudo(struct ip6_hdr *ip6, uint32_t len, uint8_t nxt, uint16_t csum)
{
int sum;
union {
u_int16_t s[2];
u_int32_t l;
} l_util;
sum = _in6_cksum_pseudo(ip6, len, nxt, csum);
REDUCE;
return (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)
* cov is the number of bytes to be taken into account for the checksum
*/
int
in6_cksum_partial(struct mbuf *m, u_int8_t nxt, u_int32_t off,
u_int32_t len, u_int32_t cov)
{
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 (cov < mlen)
mlen = cov;
cov -= 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 && cov; 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;
cov--;
} else
mlen = m->m_len;
if (cov < mlen)
mlen = cov;
cov -= 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 (cov)
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);
}
int
in6_cksum(struct mbuf *m, u_int8_t nxt, u_int32_t off, u_int32_t len)
{
return (in6_cksum_partial(m, nxt, off, len, len));
}