qemu/slirp/cksum.c
Guillaume Subiron 0d6ff71ae3 slirp: Adding IPv6, ICMPv6 Echo and NDP autoconfiguration
This patch adds the functions needed to handle IPv6 packets. ICMPv6 and
NDP headers are implemented.

Slirp is now able to send NDP Router or Neighbor Advertisement when it
receives Router or Neighbor Solicitation. Using a 64bit-sized IPv6
prefix, the guest is now able to perform stateless autoconfiguration
(SLAAC) and to compute its IPv6 address.

This patch adds an ndp_table, mainly inspired by arp_table, to keep an
NDP cache and manage network address resolution.
Slirp regularly sends NDP Neighbor Advertisement, as recommended by the
RFC, to make the guest refresh its route.

This also adds ip6_cksum() to compute ICMPv6 checksums using IPv6
pseudo-header.

Some #define ETH_* are moved upper in slirp.h to make them accessible to
other slirp/*.h

Signed-off-by: Guillaume Subiron <maethor@subiron.org>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
2016-03-15 10:35:00 +01:00

166 lines
4.5 KiB
C

/*
* 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
* in_cksum.c,v 1.2 1994/08/02 07:48:16 davidg Exp
*/
#include "qemu/osdep.h"
#include <slirp.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.
*
* XXX Since we will never span more than 1 mbuf, we can optimise this
*/
#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);}
int cksum(struct mbuf *m, int len)
{
register uint16_t *w;
register int sum = 0;
register int mlen = 0;
int byte_swapped = 0;
union {
uint8_t c[2];
uint16_t s;
} s_util;
union {
uint16_t s[2];
uint32_t l;
} l_util;
if (m->m_len == 0)
goto cont;
w = mtod(m, uint16_t *);
mlen = m->m_len;
if (len < mlen)
mlen = len;
#ifdef DEBUG
len -= mlen;
#endif
/*
* Force to even boundary.
*/
if ((1 & (uintptr_t)w) && (mlen > 0)) {
REDUCE;
sum <<= 8;
s_util.c[0] = *(uint8_t *)w;
w = (uint16_t *)((int8_t *)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)
goto cont;
REDUCE;
while ((mlen -= 2) >= 0) {
sum += *w++;
}
if (byte_swapped) {
REDUCE;
sum <<= 8;
if (mlen == -1) {
s_util.c[1] = *(uint8_t *)w;
sum += s_util.s;
mlen = 0;
} else
mlen = -1;
} else if (mlen == -1)
s_util.c[0] = *(uint8_t *)w;
cont:
#ifdef DEBUG
if (len) {
DEBUG_ERROR((dfd, "cksum: out of data\n"));
DEBUG_ERROR((dfd, " len = %d\n", len));
}
#endif
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 ip6_cksum(struct mbuf *m)
{
/* TODO: Optimize this by being able to pass the ip6_pseudohdr to cksum
* separately from the mbuf */
struct ip6 save_ip, *ip = mtod(m, struct ip6 *);
struct ip6_pseudohdr *ih = mtod(m, struct ip6_pseudohdr *);
int sum;
save_ip = *ip;
ih->ih_src = save_ip.ip_src;
ih->ih_dst = save_ip.ip_dst;
ih->ih_pl = htonl((uint32_t)ntohs(save_ip.ip_pl));
ih->ih_zero_hi = 0;
ih->ih_zero_lo = 0;
ih->ih_nh = save_ip.ip_nh;
sum = cksum(m, ((int)sizeof(struct ip6_pseudohdr))
+ ntohl(ih->ih_pl));
*ip = save_ip;
return sum;
}