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/* $OpenBSD: route6.c,v 1.16 2007/05/31 23:17:38 mcbride Exp $ */
/* $KAME: route6.c,v 1.22 2000/12/03 00:54:00 itojun Exp $ */
/*
* 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.
*/
#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/systm.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#if 0
static int ip6_rthdr0(struct mbuf *, struct ip6_hdr *, struct ip6_rthdr0 *);
#endif
int
route6_input(mp, offp, proto)
struct mbuf **mp;
int *offp, proto; /* proto is unused */
{
struct ip6_hdr *ip6;
struct mbuf *m = *mp;
struct ip6_rthdr *rh;
int off = *offp, rhlen;
ip6 = mtod(m, struct ip6_hdr *);
IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh));
if (rh == NULL) {
ip6stat.ip6s_tooshort++;
return IPPROTO_DONE;
}
switch (rh->ip6r_type) {
#if 0
/*
* See http://www.secdev.org/conf/IPv6_RH_security-csw07.pdf
* for why IPV6_RTHDR_TYPE_0 is banned here.
*
* We return ICMPv6 parameter problem so that innocent people
* (not an attacker) would notice about the use of IPV6_RTHDR_TYPE_0.
* Since there's no amplification, and ICMPv6 error will be rate-
* controlled, it shouldn't cause any problem.
* If you are concerned about this, you may want to use the following
* code fragment:
*
* case IPV6_RTHDR_TYPE_0:
* m_freem(m);
* return (IPPROTO_DONE);
*/
case IPV6_RTHDR_TYPE_0:
rhlen = (rh->ip6r_len + 1) << 3;
if (rh->ip6r_segleft == 0)
break; /* Final dst. Just ignore the header. */
/*
* note on option length:
* maximum rhlen: 2048
* max mbuf m_pulldown can handle: MCLBYTES == usually 2048
* so, here we are assuming that m_pulldown can handle
* rhlen == 2048 case. this may not be a good thing to
* assume - we may want to avoid pulling it up altogether.
*/
IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen);
if (rh == NULL) {
ip6stat.ip6s_tooshort++;
return IPPROTO_DONE;
}
if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh))
return (IPPROTO_DONE);
break;
#endif
default:
/* unknown routing type */
if (rh->ip6r_segleft == 0) {
rhlen = (rh->ip6r_len + 1) << 3;
break; /* Final dst. Just ignore the header. */
}
ip6stat.ip6s_badoptions++;
icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
(caddr_t)&rh->ip6r_type - (caddr_t)ip6);
return (IPPROTO_DONE);
}
*offp += rhlen;
return (rh->ip6r_nxt);
}
#if 0
/*
* Type0 routing header processing
*
* RFC2292 backward compatibility warning: no support for strict/loose bitmap,
* as it was dropped between RFC1883 and RFC2460.
*/
static int
ip6_rthdr0(m, ip6, rh0)
struct mbuf *m;
struct ip6_hdr *ip6;
struct ip6_rthdr0 *rh0;
{
int addrs, index;
struct in6_addr *nextaddr, tmpaddr;
if (rh0->ip6r0_segleft == 0)
return (0);
if (rh0->ip6r0_len % 2) {
/*
* Type 0 routing header can't contain more than 23 addresses.
* RFC 2460: this limitation was removed since strict/loose
* bitmap field was deleted.
*/
ip6stat.ip6s_badoptions++;
icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
(caddr_t)&rh0->ip6r0_len - (caddr_t)ip6);
return (-1);
}
if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) {
ip6stat.ip6s_badoptions++;
icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
(caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6);
return (-1);
}
index = addrs - rh0->ip6r0_segleft;
rh0->ip6r0_segleft--;
nextaddr = ((struct in6_addr *)(rh0 + 1)) + index;
/*
* reject invalid addresses. be proactive about malicious use of
* IPv4 mapped/compat address.
* XXX need more checks?
*/
if (IN6_IS_ADDR_MULTICAST(nextaddr) ||
IN6_IS_ADDR_UNSPECIFIED(nextaddr) ||
IN6_IS_ADDR_V4MAPPED(nextaddr) ||
IN6_IS_ADDR_V4COMPAT(nextaddr)) {
ip6stat.ip6s_badoptions++;
goto bad;
}
if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) ||
IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) ||
IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
ip6stat.ip6s_badoptions++;
goto bad;
}
/*
* Swap the IPv6 destination address and nextaddr. Forward the packet.
*/
tmpaddr = *nextaddr;
*nextaddr = ip6->ip6_dst;
if (IN6_IS_ADDR_LINKLOCAL(nextaddr))
nextaddr->s6_addr16[1] = 0;
ip6->ip6_dst = tmpaddr;
if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);
ip6_forward(m, 1);
return (-1); /* m would be freed in ip6_forward() */
bad:
m_freem(m);
return (-1);
}
#endif
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