/*-
* 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>
#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);}
union l_util {
uint16_t s[2];
uint32_t l;
};
union s_util {
uint8_t c[2];
uint16_t s;
};
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)
{
union l_util l_util;
int sum;
sum = _in6_cksum_pseudo(ip6, len, nxt, csum);
REDUCE;
return (sum);
}
static int
in6_cksumdata(void *data, int *lenp, uint8_t *residp, int rlen)
{
union l_util l_util;
union s_util s_util;
uint16_t *w;
int len, sum;
bool byte_swapped;
KASSERT(*lenp >= 0, ("%s: negative len %d", __func__, *lenp));
KASSERT(rlen == 0 || rlen == 1, ("%s: rlen %d", __func__, rlen));
len = *lenp;
sum = 0;
if (len == 0) {
len = rlen;
goto out;
}
byte_swapped = false;
w = data;
/*
* Do we have a residual byte left over from the previous buffer?
*/
if (rlen == 1) {
s_util.c[0] = *residp;
s_util.c[1] = *(uint8_t *)w;
sum += s_util.s;
w = (uint16_t *)((uint8_t *)w + 1);
len--;
rlen = 0;
}
/*
* Force to even boundary.
*/
if ((1 & (uintptr_t)w) && len > 0) {
REDUCE;
sum <<= 8;
s_util.c[0] = *(uint8_t *)w;
w = (uint16_t *)((uint8_t *)w + 1);
len--;
byte_swapped = true;
}
/*
* Unroll the loop to make overhead from branches &c small.
*/
while ((len -= 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;
}
len += 32;
while ((len -= 8) >= 0) {
sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
w += 4;
}
len += 8;
if (len == 0 && !byte_swapped)
goto out;
REDUCE;
while ((len -= 2) >= 0) {
sum += *w++;
}
if (byte_swapped) {
REDUCE;
sum <<= 8;
if (len == -1) {
s_util.c[1] = *(uint8_t *)w;
sum += s_util.s;
} else /* len == -2 */
*residp = s_util.c[0];
len++;
} else if (len == -1)
*residp = *(uint8_t *)w;
out:
*lenp = len & 1;
return (sum);
}
struct in6_cksum_partial_arg {
int sum;
int rlen;
uint8_t resid;
};
static int
in6_cksum_partial_one(void *_arg, void *data, u_int len)
{
struct in6_cksum_partial_arg *arg = _arg;
arg->sum += in6_cksumdata(data, &len, &arg->resid, arg->rlen);
arg->rlen = len;
return (0);
}
/*
* 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, uint8_t nxt, uint32_t off, uint32_t len,
uint32_t cov)
{
struct in6_cksum_partial_arg arg;
union l_util l_util;
union s_util s_util;
struct ip6_hdr *ip6;
uint16_t *w, scope;
int sum;
union {
uint16_t phs[4];
struct {
uint32_t ph_len;
uint8_t ph_zero[3];
uint8_t ph_nxt;
} __packed ph;
} uph;
/* Sanity check. */
KASSERT(m->m_pkthdr.len >= off + len, ("%s: mbuf len (%d) < off(%d)+"
"len(%d)", __func__, m->m_pkthdr.len, off, len));
KASSERT(m->m_len >= sizeof(*ip6),
("%s: mbuf len %d < sizeof(ip6)", __func__, m->m_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 = (uint16_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 = (uint16_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;
/*
* Loop over the rest of the mbuf chain and compute the rest of the
* checksum. m_apply() handles unmapped mbufs.
*/
arg.sum = sum;
arg.rlen = 0;
(void)m_apply(m, off, cov, in6_cksum_partial_one, &arg);
sum = arg.sum;
/*
* Handle a residual byte.
*/
if (arg.rlen == 1) {
s_util.c[0] = arg.resid;
s_util.c[1] = 0;
sum += s_util.s;
}
REDUCE;
return (~sum & 0xffff);
}
int
in6_cksum(struct mbuf *m, uint8_t nxt, uint32_t off, uint32_t len)
{
return (in6_cksum_partial(m, nxt, off, len, len));
}
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