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freebsd-dev/sys/netinet6/ip6_input.c
Hajimu UMEMOTO 0776834a11 __FreeBSD__ is not a compiler constant. We must use 
__FreeBSD_version here.

Submitted by:	rwatson
2002-05-31 17:56:45 +00:00

1673 lines
42 KiB
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/* $FreeBSD$ */
/* $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei 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.
*/
/*
* Copyright (c) 1982, 1986, 1988, 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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.
*
* @(#)ip_input.c 8.2 (Berkeley) 1/4/94
*/
#include "opt_ip6fw.h"
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipsec.h"
#include "opt_pfil_hooks.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <net/netisr.h>
#include <net/intrq.h>
#ifdef PFIL_HOOKS
#include <net/pfil.h>
#endif
#include <netinet/in.h>
#include <netinet/in_systm.h>
#ifdef INET
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#endif /* INET */
#include <netinet/ip6.h>
#include <netinet6/in6_var.h>
#include <netinet6/ip6_var.h>
#include <netinet/in_pcb.h>
#include <netinet/icmp6.h>
#include <netinet6/in6_ifattach.h>
#include <netinet6/nd6.h>
#include <netinet6/in6_prefix.h>
#ifdef IPSEC
#include <netinet6/ipsec.h>
#ifdef INET6
#include <netinet6/ipsec6.h>
#endif
#endif
#include <netinet6/ip6_fw.h>
#include <netinet6/ip6protosw.h>
#include <net/net_osdep.h>
extern struct domain inet6domain;
u_char ip6_protox[IPPROTO_MAX];
static int ip6qmaxlen = IFQ_MAXLEN;
struct in6_ifaddr *in6_ifaddr;
extern struct callout in6_tmpaddrtimer_ch;
int ip6_forward_srcrt; /* XXX */
int ip6_sourcecheck; /* XXX */
int ip6_sourcecheck_interval; /* XXX */
int ip6_ours_check_algorithm;
/* firewall hooks */
ip6_fw_chk_t *ip6_fw_chk_ptr;
ip6_fw_ctl_t *ip6_fw_ctl_ptr;
int ip6_fw_enable = 1;
struct ip6stat ip6stat;
static void ip6_init2 __P((void *));
static struct mbuf *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *));
static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *));
#ifdef PULLDOWN_TEST
static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int));
#endif
/*
* IP6 initialization: fill in IP6 protocol switch table.
* All protocols not implemented in kernel go to raw IP6 protocol handler.
*/
void
ip6_init()
{
struct ip6protosw *pr;
int i;
struct timeval tv;
#ifdef DIAGNOSTIC
if (sizeof(struct protosw) != sizeof(struct ip6protosw))
panic("sizeof(protosw) != sizeof(ip6protosw)");
#endif
pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
if (pr == 0)
panic("ip6_init");
for (i = 0; i < IPPROTO_MAX; i++)
ip6_protox[i] = pr - inet6sw;
for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++)
if (pr->pr_domain->dom_family == PF_INET6 &&
pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
ip6_protox[pr->pr_protocol] = pr - inet6sw;
ip6intrq.ifq_maxlen = ip6qmaxlen;
mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF);
ip6intrq_present = 1;
register_netisr(NETISR_IPV6, ip6intr);
nd6_init();
frag6_init();
/*
* in many cases, random() here does NOT return random number
* as initialization during bootstrap time occur in fixed order.
*/
microtime(&tv);
ip6_flow_seq = random() ^ tv.tv_usec;
microtime(&tv);
ip6_desync_factor = (random() ^ tv.tv_usec) % MAX_TEMP_DESYNC_FACTOR;
}
static void
ip6_init2(dummy)
void *dummy;
{
/*
* to route local address of p2p link to loopback,
* assign loopback address first.
*/
in6_ifattach(&loif[0], NULL);
/* nd6_timer_init */
callout_init(&nd6_timer_ch, 0);
callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL);
/* router renumbering prefix list maintenance */
callout_init(&in6_rr_timer_ch, 0);
callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL);
/* timer for regeneranation of temporary addresses randomize ID */
callout_reset(&in6_tmpaddrtimer_ch,
(ip6_temp_preferred_lifetime - ip6_desync_factor -
ip6_temp_regen_advance) * hz,
in6_tmpaddrtimer, NULL);
}
/* cheat */
/* This must be after route_init(), which is now SI_ORDER_THIRD */
SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL);
/*
* IP6 input interrupt handling. Just pass the packet to ip6_input.
*/
void
ip6intr()
{
int s;
struct mbuf *m;
for (;;) {
s = splimp();
IF_DEQUEUE(&ip6intrq, m);
splx(s);
if (m == 0)
return;
ip6_input(m);
}
}
extern struct route_in6 ip6_forward_rt;
void
ip6_input(m)
struct mbuf *m;
{
struct ip6_hdr *ip6;
int off = sizeof(struct ip6_hdr), nest;
u_int32_t plen;
u_int32_t rtalert = ~0;
int nxt, ours = 0;
struct ifnet *deliverifp = NULL;
#ifdef PFIL_HOOKS
struct packet_filter_hook *pfh;
struct mbuf *m0;
int rv;
#endif /* PFIL_HOOKS */
#ifdef IPSEC
/*
* should the inner packet be considered authentic?
* see comment in ah4_input().
*/
if (m) {
m->m_flags &= ~M_AUTHIPHDR;
m->m_flags &= ~M_AUTHIPDGM;
}
#endif
/*
* make sure we don't have onion peering information into m_aux.
*/
ip6_delaux(m);
/*
* mbuf statistics
*/
if (m->m_flags & M_EXT) {
if (m->m_next)
ip6stat.ip6s_mext2m++;
else
ip6stat.ip6s_mext1++;
} else {
#define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0]))
if (m->m_next) {
if (m->m_flags & M_LOOP) {
ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */
} else if (m->m_pkthdr.rcvif->if_index < M2MMAX)
ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++;
else
ip6stat.ip6s_m2m[0]++;
} else
ip6stat.ip6s_m1++;
#undef M2MMAX
}
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
ip6stat.ip6s_total++;
#ifndef PULLDOWN_TEST
/*
* L2 bridge code and some other code can return mbuf chain
* that does not conform to KAME requirement. too bad.
* XXX: fails to join if interface MTU > MCLBYTES. jumbogram?
*/
if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) {
struct mbuf *n;
MGETHDR(n, M_DONTWAIT, MT_HEADER);
if (n)
M_COPY_PKTHDR(n, m);
if (n && m->m_pkthdr.len > MHLEN) {
MCLGET(n, M_DONTWAIT);
if ((n->m_flags & M_EXT) == 0) {
m_freem(n);
n = NULL;
}
}
if (n == NULL) {
m_freem(m);
return; /*ENOBUFS*/
}
m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t));
n->m_len = m->m_pkthdr.len;
m_freem(m);
m = n;
}
IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /*nothing*/);
#endif
if (m->m_len < sizeof(struct ip6_hdr)) {
struct ifnet *inifp;
inifp = m->m_pkthdr.rcvif;
if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == 0) {
ip6stat.ip6s_toosmall++;
in6_ifstat_inc(inifp, ifs6_in_hdrerr);
return;
}
}
ip6 = mtod(m, struct ip6_hdr *);
if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
ip6stat.ip6s_badvers++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
goto bad;
}
#ifdef PFIL_HOOKS
/*
* Run through list of hooks for input packets. If there are any
* filters which require that additional packets in the flow are
* not fast-forwarded, they must clear the M_CANFASTFWD flag.
* Note that filters must _never_ set this flag, as another filter
* in the list may have previously cleared it.
*/
m0 = m;
pfh = pfil_hook_get(PFIL_IN, &inet6sw[ip6_protox[IPPROTO_IPV6]].pr_pfh);
for (; pfh; pfh = pfh->pfil_link.tqe_next)
if (pfh->pfil_func) {
rv = pfh->pfil_func(ip6, sizeof(*ip6),
m->m_pkthdr.rcvif, 0, &m0);
if (rv)
return;
m = m0;
if (m == NULL)
return;
ip6 = mtod(m, struct ip6_hdr *);
}
#endif /* PFIL_HOOKS */
ip6stat.ip6s_nxthist[ip6->ip6_nxt]++;
/*
* Check with the firewall...
*/
if (ip6_fw_enable && ip6_fw_chk_ptr) {
u_short port = 0;
/* If ipfw says divert, we have to just drop packet */
/* use port as a dummy argument */
if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) {
m_freem(m);
m = NULL;
}
if (!m)
return;
}
/*
* Check against address spoofing/corruption.
*/
if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
/*
* XXX: "badscope" is not very suitable for a multicast source.
*/
ip6stat.ip6s_badscope++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
goto bad;
}
if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) ||
IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) &&
(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
ip6stat.ip6s_badscope++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
goto bad;
}
/*
* The following check is not documented in specs. A malicious
* party may be able to use IPv4 mapped addr to confuse tcp/udp stack
* and bypass security checks (act as if it was from 127.0.0.1 by using
* IPv6 src ::ffff:127.0.0.1). Be cautious.
*
* This check chokes if we are in an SIIT cloud. As none of BSDs
* support IPv4-less kernel compilation, we cannot support SIIT
* environment at all. So, it makes more sense for us to reject any
* malicious packets for non-SIIT environment, than try to do a
* partical support for SIIT environment.
*/
if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
ip6stat.ip6s_badscope++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
goto bad;
}
#if 0
/*
* Reject packets with IPv4 compatible addresses (auto tunnel).
*
* The code forbids auto tunnel relay case in RFC1933 (the check is
* stronger than RFC1933). We may want to re-enable it if mech-xx
* is revised to forbid relaying case.
*/
if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
ip6stat.ip6s_badscope++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
goto bad;
}
#endif
/* drop packets if interface ID portion is already filled */
if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) &&
ip6->ip6_src.s6_addr16[1]) {
ip6stat.ip6s_badscope++;
goto bad;
}
if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) &&
ip6->ip6_dst.s6_addr16[1]) {
ip6stat.ip6s_badscope++;
goto bad;
}
}
if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
ip6->ip6_src.s6_addr16[1]
= htons(m->m_pkthdr.rcvif->if_index);
if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
ip6->ip6_dst.s6_addr16[1]
= htons(m->m_pkthdr.rcvif->if_index);
#if 0 /* this case seems to be unnecessary. (jinmei, 20010401) */
/*
* We use rt->rt_ifp to determine if the address is ours or not.
* If rt_ifp is lo0, the address is ours.
* The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0,
* so any address under fe80::%lo0/64 will be mistakenly considered
* local. The special case is supplied to handle the case properly
* by actually looking at interface addresses
* (using in6ifa_ifpwithaddr).
*/
if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 &&
IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) {
if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) {
icmp6_error(m, ICMP6_DST_UNREACH,
ICMP6_DST_UNREACH_ADDR, 0);
/* m is already freed */
return;
}
ours = 1;
deliverifp = m->m_pkthdr.rcvif;
goto hbhcheck;
}
#endif
/*
* Multicast check
*/
if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
struct in6_multi *in6m = 0;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
/*
* See if we belong to the destination multicast group on the
* arrival interface.
*/
IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m);
if (in6m)
ours = 1;
else if (!ip6_mrouter) {
ip6stat.ip6s_notmember++;
ip6stat.ip6s_cantforward++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
goto bad;
}
deliverifp = m->m_pkthdr.rcvif;
goto hbhcheck;
}
/*
* Unicast check
*/
switch (ip6_ours_check_algorithm) {
default:
/*
* XXX: I intentionally broke our indentation rule here,
* since this switch-case is just for measurement and
* therefore should soon be removed.
*/
if (ip6_forward_rt.ro_rt != NULL &&
(ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 &&
IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
&((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr))
ip6stat.ip6s_forward_cachehit++;
else {
struct sockaddr_in6 *dst6;
if (ip6_forward_rt.ro_rt) {
/* route is down or destination is different */
ip6stat.ip6s_forward_cachemiss++;
RTFREE(ip6_forward_rt.ro_rt);
ip6_forward_rt.ro_rt = 0;
}
bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6));
dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst;
dst6->sin6_len = sizeof(struct sockaddr_in6);
dst6->sin6_family = AF_INET6;
dst6->sin6_addr = ip6->ip6_dst;
#ifdef SCOPEDROUTING
ip6_forward_rt.ro_dst.sin6_scope_id =
in6_addr2scopeid(m->m_pkthdr.rcvif, &ip6->ip6_dst);
#endif
rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING);
}
#define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))
/*
* Accept the packet if the forwarding interface to the destination
* according to the routing table is the loopback interface,
* unless the associated route has a gateway.
* Note that this approach causes to accept a packet if there is a
* route to the loopback interface for the destination of the packet.
* But we think it's even useful in some situations, e.g. when using
* a special daemon which wants to intercept the packet.
*
* XXX: some OSes automatically make a cloned route for the destination
* of an outgoing packet. If the outgoing interface of the packet
* is a loopback one, the kernel would consider the packet to be
* accepted, even if we have no such address assinged on the interface.
* We check the cloned flag of the route entry to reject such cases,
* assuming that route entries for our own addresses are not made by
* cloning (it should be true because in6_addloop explicitly installs
* the host route). However, we might have to do an explicit check
* while it would be less efficient. Or, should we rather install a
* reject route for such a case?
*/
if (ip6_forward_rt.ro_rt &&
(ip6_forward_rt.ro_rt->rt_flags &
(RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
#ifdef RTF_WASCLONED
!(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) &&
#endif
#ifdef RTF_CLONED
!(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) &&
#endif
#if 0
/*
* The check below is redundant since the comparison of
* the destination and the key of the rtentry has
* already done through looking up the routing table.
*/
IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
&rt6_key(ip6_forward_rt.ro_rt)->sin6_addr)
#endif
ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) {
struct in6_ifaddr *ia6 =
(struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa;
/*
* record address information into m_aux.
*/
(void)ip6_setdstifaddr(m, ia6);
/*
* packets to a tentative, duplicated, or somehow invalid
* address must not be accepted.
*/
if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
/* this address is ready */
ours = 1;
deliverifp = ia6->ia_ifp; /* correct? */
/* Count the packet in the ip address stats */
ia6->ia_ifa.if_ipackets++;
ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
goto hbhcheck;
} else {
/* address is not ready, so discard the packet. */
nd6log((LOG_INFO,
"ip6_input: packet to an unready address %s->%s\n",
ip6_sprintf(&ip6->ip6_src),
ip6_sprintf(&ip6->ip6_dst)));
goto bad;
}
}
} /* XXX indentation (see above) */
/*
* FAITH(Firewall Aided Internet Translator)
*/
if (ip6_keepfaith) {
if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp
&& ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) {
/* XXX do we need more sanity checks? */
ours = 1;
deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */
goto hbhcheck;
}
}
/*
* Now there is no reason to process the packet if it's not our own
* and we're not a router.
*/
if (!ip6_forwarding) {
ip6stat.ip6s_cantforward++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
goto bad;
}
hbhcheck:
/*
* record address information into m_aux, if we don't have one yet.
* note that we are unable to record it, if the address is not listed
* as our interface address (e.g. multicast addresses, addresses
* within FAITH prefixes and such).
*/
if (deliverifp && !ip6_getdstifaddr(m)) {
struct in6_ifaddr *ia6;
ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
if (ia6) {
if (!ip6_setdstifaddr(m, ia6)) {
/*
* XXX maybe we should drop the packet here,
* as we could not provide enough information
* to the upper layers.
*/
}
}
}
/*
* Process Hop-by-Hop options header if it's contained.
* m may be modified in ip6_hopopts_input().
* If a JumboPayload option is included, plen will also be modified.
*/
plen = (u_int32_t)ntohs(ip6->ip6_plen);
if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
struct ip6_hbh *hbh;
if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) {
#if 0 /*touches NULL pointer*/
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
#endif
return; /* m have already been freed */
}
/* adjust pointer */
ip6 = mtod(m, struct ip6_hdr *);
/*
* if the payload length field is 0 and the next header field
* indicates Hop-by-Hop Options header, then a Jumbo Payload
* option MUST be included.
*/
if (ip6->ip6_plen == 0 && plen == 0) {
/*
* Note that if a valid jumbo payload option is
* contained, ip6_hoptops_input() must set a valid
* (non-zero) payload length to the variable plen.
*/
ip6stat.ip6s_badoptions++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
icmp6_error(m, ICMP6_PARAM_PROB,
ICMP6_PARAMPROB_HEADER,
(caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
return;
}
#ifndef PULLDOWN_TEST
/* ip6_hopopts_input() ensures that mbuf is contiguous */
hbh = (struct ip6_hbh *)(ip6 + 1);
#else
IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
sizeof(struct ip6_hbh));
if (hbh == NULL) {
ip6stat.ip6s_tooshort++;
return;
}
#endif
nxt = hbh->ip6h_nxt;
/*
* accept the packet if a router alert option is included
* and we act as an IPv6 router.
*/
if (rtalert != ~0 && ip6_forwarding)
ours = 1;
} else
nxt = ip6->ip6_nxt;
/*
* Check that the amount of data in the buffers
* is as at least much as the IPv6 header would have us expect.
* Trim mbufs if longer than we expect.
* Drop packet if shorter than we expect.
*/
if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
ip6stat.ip6s_tooshort++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
goto bad;
}
if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
if (m->m_len == m->m_pkthdr.len) {
m->m_len = sizeof(struct ip6_hdr) + plen;
m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
} else
m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
}
/*
* Forward if desirable.
*/
if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
/*
* If we are acting as a multicast router, all
* incoming multicast packets are passed to the
* kernel-level multicast forwarding function.
* The packet is returned (relatively) intact; if
* ip6_mforward() returns a non-zero value, the packet
* must be discarded, else it may be accepted below.
*/
if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
ip6stat.ip6s_cantforward++;
m_freem(m);
return;
}
if (!ours) {
m_freem(m);
return;
}
} else if (!ours) {
ip6_forward(m, 0);
return;
}
ip6 = mtod(m, struct ip6_hdr *);
/*
* Malicious party may be able to use IPv4 mapped addr to confuse
* tcp/udp stack and bypass security checks (act as if it was from
* 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious.
*
* For SIIT end node behavior, you may want to disable the check.
* However, you will become vulnerable to attacks using IPv4 mapped
* source.
*/
if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
ip6stat.ip6s_badscope++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
goto bad;
}
/*
* Tell launch routine the next header
*/
ip6stat.ip6s_delivered++;
in6_ifstat_inc(deliverifp, ifs6_in_deliver);
nest = 0;
while (nxt != IPPROTO_DONE) {
if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
ip6stat.ip6s_toomanyhdr++;
goto bad;
}
/*
* protection against faulty packet - there should be
* more sanity checks in header chain processing.
*/
if (m->m_pkthdr.len < off) {
ip6stat.ip6s_tooshort++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
goto bad;
}
#if 0
/*
* do we need to do it for every header? yeah, other
* functions can play with it (like re-allocate and copy).
*/
mhist = ip6_addaux(m);
if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) {
hist = mtod(mhist, caddr_t) + mhist->m_len;
bcopy(&nxt, hist, sizeof(nxt));
mhist->m_len += sizeof(nxt);
} else {
ip6stat.ip6s_toomanyhdr++;
goto bad;
}
#endif
#ifdef IPSEC
/*
* enforce IPsec policy checking if we are seeing last header.
* note that we do not visit this with protocols with pcb layer
* code - like udp/tcp/raw ip.
*/
if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
ipsec6_in_reject(m, NULL)) {
ipsec6stat.in_polvio++;
goto bad;
}
#endif
nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
}
return;
bad:
m_freem(m);
}
/*
* set/grab in6_ifaddr correspond to IPv6 destination address.
* XXX backward compatibility wrapper
*/
static struct mbuf *
ip6_setdstifaddr(m, ia6)
struct mbuf *m;
struct in6_ifaddr *ia6;
{
struct mbuf *n;
n = ip6_addaux(m);
if (n)
mtod(n, struct ip6aux *)->ip6a_dstia6 = ia6;
return n; /* NULL if failed to set */
}
struct in6_ifaddr *
ip6_getdstifaddr(m)
struct mbuf *m;
{
struct mbuf *n;
n = ip6_findaux(m);
if (n)
return mtod(n, struct ip6aux *)->ip6a_dstia6;
else
return NULL;
}
/*
* Hop-by-Hop options header processing. If a valid jumbo payload option is
* included, the real payload length will be stored in plenp.
*/
static int
ip6_hopopts_input(plenp, rtalertp, mp, offp)
u_int32_t *plenp;
u_int32_t *rtalertp; /* XXX: should be stored more smart way */
struct mbuf **mp;
int *offp;
{
struct mbuf *m = *mp;
int off = *offp, hbhlen;
struct ip6_hbh *hbh;
u_int8_t *opt;
/* validation of the length of the header */
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1);
hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
hbhlen = (hbh->ip6h_len + 1) << 3;
IP6_EXTHDR_CHECK(m, off, hbhlen, -1);
hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
#else
IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
if (hbh == NULL) {
ip6stat.ip6s_tooshort++;
return -1;
}
hbhlen = (hbh->ip6h_len + 1) << 3;
IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
hbhlen);
if (hbh == NULL) {
ip6stat.ip6s_tooshort++;
return -1;
}
#endif
off += hbhlen;
hbhlen -= sizeof(struct ip6_hbh);
opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh);
if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
hbhlen, rtalertp, plenp) < 0)
return(-1);
*offp = off;
*mp = m;
return(0);
}
/*
* Search header for all Hop-by-hop options and process each option.
* This function is separate from ip6_hopopts_input() in order to
* handle a case where the sending node itself process its hop-by-hop
* options header. In such a case, the function is called from ip6_output().
*
* The function assumes that hbh header is located right after the IPv6 header
* (RFC2460 p7), opthead is pointer into data content in m, and opthead to
* opthead + hbhlen is located in continuous memory region.
*/
int
ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp)
struct mbuf *m;
u_int8_t *opthead;
int hbhlen;
u_int32_t *rtalertp;
u_int32_t *plenp;
{
struct ip6_hdr *ip6;
int optlen = 0;
u_int8_t *opt = opthead;
u_int16_t rtalert_val;
u_int32_t jumboplen;
const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
switch (*opt) {
case IP6OPT_PAD1:
optlen = 1;
break;
case IP6OPT_PADN:
if (hbhlen < IP6OPT_MINLEN) {
ip6stat.ip6s_toosmall++;
goto bad;
}
optlen = *(opt + 1) + 2;
break;
case IP6OPT_RTALERT:
/* XXX may need check for alignment */
if (hbhlen < IP6OPT_RTALERT_LEN) {
ip6stat.ip6s_toosmall++;
goto bad;
}
if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
/* XXX stat */
icmp6_error(m, ICMP6_PARAM_PROB,
ICMP6_PARAMPROB_HEADER,
erroff + opt + 1 - opthead);
return(-1);
}
optlen = IP6OPT_RTALERT_LEN;
bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
*rtalertp = ntohs(rtalert_val);
break;
case IP6OPT_JUMBO:
/* XXX may need check for alignment */
if (hbhlen < IP6OPT_JUMBO_LEN) {
ip6stat.ip6s_toosmall++;
goto bad;
}
if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
/* XXX stat */
icmp6_error(m, ICMP6_PARAM_PROB,
ICMP6_PARAMPROB_HEADER,
erroff + opt + 1 - opthead);
return(-1);
}
optlen = IP6OPT_JUMBO_LEN;
/*
* IPv6 packets that have non 0 payload length
* must not contain a jumbo payload option.
*/
ip6 = mtod(m, struct ip6_hdr *);
if (ip6->ip6_plen) {
ip6stat.ip6s_badoptions++;
icmp6_error(m, ICMP6_PARAM_PROB,
ICMP6_PARAMPROB_HEADER,
erroff + opt - opthead);
return(-1);
}
/*
* We may see jumbolen in unaligned location, so
* we'd need to perform bcopy().
*/
bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
jumboplen = (u_int32_t)htonl(jumboplen);
#if 1
/*
* if there are multiple jumbo payload options,
* *plenp will be non-zero and the packet will be
* rejected.
* the behavior may need some debate in ipngwg -
* multiple options does not make sense, however,
* there's no explicit mention in specification.
*/
if (*plenp != 0) {
ip6stat.ip6s_badoptions++;
icmp6_error(m, ICMP6_PARAM_PROB,
ICMP6_PARAMPROB_HEADER,
erroff + opt + 2 - opthead);
return(-1);
}
#endif
/*
* jumbo payload length must be larger than 65535.
*/
if (jumboplen <= IPV6_MAXPACKET) {
ip6stat.ip6s_badoptions++;
icmp6_error(m, ICMP6_PARAM_PROB,
ICMP6_PARAMPROB_HEADER,
erroff + opt + 2 - opthead);
return(-1);
}
*plenp = jumboplen;
break;
default: /* unknown option */
if (hbhlen < IP6OPT_MINLEN) {
ip6stat.ip6s_toosmall++;
goto bad;
}
optlen = ip6_unknown_opt(opt, m,
erroff + opt - opthead);
if (optlen == -1)
return(-1);
optlen += 2;
break;
}
}
return(0);
bad:
m_freem(m);
return(-1);
}
/*
* Unknown option processing.
* The third argument `off' is the offset from the IPv6 header to the option,
* which is necessary if the IPv6 header the and option header and IPv6 header
* is not continuous in order to return an ICMPv6 error.
*/
int
ip6_unknown_opt(optp, m, off)
u_int8_t *optp;
struct mbuf *m;
int off;
{
struct ip6_hdr *ip6;
switch (IP6OPT_TYPE(*optp)) {
case IP6OPT_TYPE_SKIP: /* ignore the option */
return((int)*(optp + 1));
case IP6OPT_TYPE_DISCARD: /* silently discard */
m_freem(m);
return(-1);
case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
ip6stat.ip6s_badoptions++;
icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
return(-1);
case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
ip6stat.ip6s_badoptions++;
ip6 = mtod(m, struct ip6_hdr *);
if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
(m->m_flags & (M_BCAST|M_MCAST)))
m_freem(m);
else
icmp6_error(m, ICMP6_PARAM_PROB,
ICMP6_PARAMPROB_OPTION, off);
return(-1);
}
m_freem(m); /* XXX: NOTREACHED */
return(-1);
}
/*
* Create the "control" list for this pcb.
* The function will not modify mbuf chain at all.
*
* with KAME mbuf chain restriction:
* The routine will be called from upper layer handlers like tcp6_input().
* Thus the routine assumes that the caller (tcp6_input) have already
* called IP6_EXTHDR_CHECK() and all the extension headers are located in the
* very first mbuf on the mbuf chain.
*/
void
ip6_savecontrol(in6p, mp, ip6, m)
struct inpcb *in6p;
struct mbuf **mp;
struct ip6_hdr *ip6;
struct mbuf *m;
{
#if __FreeBSD_version >= 500000
struct thread *td = curthread; /* XXX */
#else
struct proc *td = curproc; /* XXX */
#endif
int privileged = 0;
int rthdr_exist = 0;
if (td && !suser(td))
privileged++;
#ifdef SO_TIMESTAMP
if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) {
struct timeval tv;
microtime(&tv);
*mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
SCM_TIMESTAMP, SOL_SOCKET);
if (*mp) {
mp = &(*mp)->m_next;
}
}
#endif
/* RFC 2292 sec. 5 */
if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) {
struct in6_pktinfo pi6;
bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr))
pi6.ipi6_addr.s6_addr16[1] = 0;
pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif)
? m->m_pkthdr.rcvif->if_index
: 0;
*mp = sbcreatecontrol((caddr_t) &pi6,
sizeof(struct in6_pktinfo), IPV6_PKTINFO,
IPPROTO_IPV6);
if (*mp)
mp = &(*mp)->m_next;
}
if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) {
int hlim = ip6->ip6_hlim & 0xff;
*mp = sbcreatecontrol((caddr_t) &hlim,
sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6);
if (*mp)
mp = &(*mp)->m_next;
}
/*
* IPV6_HOPOPTS socket option. We require super-user privilege
* for the option, but it might be too strict, since there might
* be some hop-by-hop options which can be returned to normal user.
* See RFC 2292 section 6.
*/
if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0 && privileged) {
/*
* Check if a hop-by-hop options header is contatined in the
* received packet, and if so, store the options as ancillary
* data. Note that a hop-by-hop options header must be
* just after the IPv6 header, which fact is assured through
* the IPv6 input processing.
*/
struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
struct ip6_hbh *hbh;
int hbhlen = 0;
#ifdef PULLDOWN_TEST
struct mbuf *ext;
#endif
#ifndef PULLDOWN_TEST
hbh = (struct ip6_hbh *)(ip6 + 1);
hbhlen = (hbh->ip6h_len + 1) << 3;
#else
ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
ip6->ip6_nxt);
if (ext == NULL) {
ip6stat.ip6s_tooshort++;
return;
}
hbh = mtod(ext, struct ip6_hbh *);
hbhlen = (hbh->ip6h_len + 1) << 3;
if (hbhlen != ext->m_len) {
m_freem(ext);
ip6stat.ip6s_tooshort++;
return;
}
#endif
/*
* XXX: We copy whole the header even if a jumbo
* payload option is included, which option is to
* be removed before returning in the RFC 2292.
* Note: this constraint is removed in 2292bis.
*/
*mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
IPV6_HOPOPTS, IPPROTO_IPV6);
if (*mp)
mp = &(*mp)->m_next;
#ifdef PULLDOWN_TEST
m_freem(ext);
#endif
}
}
/* IPV6_DSTOPTS and IPV6_RTHDR socket options */
if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) {
int proto, off, nxt;
/*
* go through the header chain to see if a routing header is
* contained in the packet. We need this information to store
* destination options headers (if any) properly.
* XXX: performance issue. We should record this info when
* processing extension headers in incoming routine.
* (todo) use m_aux?
*/
proto = IPPROTO_IPV6;
off = 0;
nxt = -1;
while (1) {
int newoff;
newoff = ip6_nexthdr(m, off, proto, &nxt);
if (newoff < 0)
break;
if (newoff < off) /* invalid, check for safety */
break;
if ((proto = nxt) == IPPROTO_ROUTING) {
rthdr_exist = 1;
break;
}
off = newoff;
}
}
if ((in6p->in6p_flags &
(IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) {
struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
/*
* Search for destination options headers or routing
* header(s) through the header chain, and stores each
* header as ancillary data.
* Note that the order of the headers remains in
* the chain of ancillary data.
*/
while (1) { /* is explicit loop prevention necessary? */
struct ip6_ext *ip6e = NULL;
int elen;
#ifdef PULLDOWN_TEST
struct mbuf *ext = NULL;
#endif
/*
* if it is not an extension header, don't try to
* pull it from the chain.
*/
switch (nxt) {
case IPPROTO_DSTOPTS:
case IPPROTO_ROUTING:
case IPPROTO_HOPOPTS:
case IPPROTO_AH: /* is it possible? */
break;
default:
goto loopend;
}
#ifndef PULLDOWN_TEST
if (off + sizeof(*ip6e) > m->m_len)
goto loopend;
ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
if (nxt == IPPROTO_AH)
elen = (ip6e->ip6e_len + 2) << 2;
else
elen = (ip6e->ip6e_len + 1) << 3;
if (off + elen > m->m_len)
goto loopend;
#else
ext = ip6_pullexthdr(m, off, nxt);
if (ext == NULL) {
ip6stat.ip6s_tooshort++;
return;
}
ip6e = mtod(ext, struct ip6_ext *);
if (nxt == IPPROTO_AH)
elen = (ip6e->ip6e_len + 2) << 2;
else
elen = (ip6e->ip6e_len + 1) << 3;
if (elen != ext->m_len) {
m_freem(ext);
ip6stat.ip6s_tooshort++;
return;
}
#endif
switch (nxt) {
case IPPROTO_DSTOPTS:
if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0)
break;
/*
* We also require super-user privilege for
* the option.
* See the comments on IN6_HOPOPTS.
*/
if (!privileged)
break;
*mp = sbcreatecontrol((caddr_t)ip6e, elen,
IPV6_DSTOPTS,
IPPROTO_IPV6);
if (*mp)
mp = &(*mp)->m_next;
break;
case IPPROTO_ROUTING:
if (!in6p->in6p_flags & IN6P_RTHDR)
break;
*mp = sbcreatecontrol((caddr_t)ip6e, elen,
IPV6_RTHDR,
IPPROTO_IPV6);
if (*mp)
mp = &(*mp)->m_next;
break;
case IPPROTO_HOPOPTS:
case IPPROTO_AH: /* is it possible? */
break;
default:
/*
* other cases have been filtered in the above.
* none will visit this case. here we supply
* the code just in case (nxt overwritten or
* other cases).
*/
#ifdef PULLDOWN_TEST
m_freem(ext);
#endif
goto loopend;
}
/* proceed with the next header. */
off += elen;
nxt = ip6e->ip6e_nxt;
ip6e = NULL;
#ifdef PULLDOWN_TEST
m_freem(ext);
ext = NULL;
#endif
}
loopend:
;
}
}
#ifdef PULLDOWN_TEST
/*
* pull single extension header from mbuf chain. returns single mbuf that
* contains the result, or NULL on error.
*/
static struct mbuf *
ip6_pullexthdr(m, off, nxt)
struct mbuf *m;
size_t off;
int nxt;
{
struct ip6_ext ip6e;
size_t elen;
struct mbuf *n;
#ifdef DIAGNOSTIC
switch (nxt) {
case IPPROTO_DSTOPTS:
case IPPROTO_ROUTING:
case IPPROTO_HOPOPTS:
case IPPROTO_AH: /* is it possible? */
break;
default:
printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
}
#endif
m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
if (nxt == IPPROTO_AH)
elen = (ip6e.ip6e_len + 2) << 2;
else
elen = (ip6e.ip6e_len + 1) << 3;
MGET(n, M_DONTWAIT, MT_DATA);
if (n && elen >= MLEN) {
MCLGET(n, M_DONTWAIT);
if ((n->m_flags & M_EXT) == 0) {
m_free(n);
n = NULL;
}
}
if (!n)
return NULL;
n->m_len = 0;
if (elen >= M_TRAILINGSPACE(n)) {
m_free(n);
return NULL;
}
m_copydata(m, off, elen, mtod(n, caddr_t));
n->m_len = elen;
return n;
}
#endif
/*
* Get pointer to the previous header followed by the header
* currently processed.
* XXX: This function supposes that
* M includes all headers,
* the next header field and the header length field of each header
* are valid, and
* the sum of each header length equals to OFF.
* Because of these assumptions, this function must be called very
* carefully. Moreover, it will not be used in the near future when
* we develop `neater' mechanism to process extension headers.
*/
char *
ip6_get_prevhdr(m, off)
struct mbuf *m;
int off;
{
struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
if (off == sizeof(struct ip6_hdr))
return(&ip6->ip6_nxt);
else {
int len, nxt;
struct ip6_ext *ip6e = NULL;
nxt = ip6->ip6_nxt;
len = sizeof(struct ip6_hdr);
while (len < off) {
ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);
switch (nxt) {
case IPPROTO_FRAGMENT:
len += sizeof(struct ip6_frag);
break;
case IPPROTO_AH:
len += (ip6e->ip6e_len + 2) << 2;
break;
default:
len += (ip6e->ip6e_len + 1) << 3;
break;
}
nxt = ip6e->ip6e_nxt;
}
if (ip6e)
return(&ip6e->ip6e_nxt);
else
return NULL;
}
}
/*
* get next header offset. m will be retained.
*/
int
ip6_nexthdr(m, off, proto, nxtp)
struct mbuf *m;
int off;
int proto;
int *nxtp;
{
struct ip6_hdr ip6;
struct ip6_ext ip6e;
struct ip6_frag fh;
/* just in case */
if (m == NULL)
panic("ip6_nexthdr: m == NULL");
if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
return -1;
switch (proto) {
case IPPROTO_IPV6:
if (m->m_pkthdr.len < off + sizeof(ip6))
return -1;
m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
if (nxtp)
*nxtp = ip6.ip6_nxt;
off += sizeof(ip6);
return off;
case IPPROTO_FRAGMENT:
/*
* terminate parsing if it is not the first fragment,
* it does not make sense to parse through it.
*/
if (m->m_pkthdr.len < off + sizeof(fh))
return -1;
m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
if ((ntohs(fh.ip6f_offlg) & IP6F_OFF_MASK) != 0)
return -1;
if (nxtp)
*nxtp = fh.ip6f_nxt;
off += sizeof(struct ip6_frag);
return off;
case IPPROTO_AH:
if (m->m_pkthdr.len < off + sizeof(ip6e))
return -1;
m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
if (nxtp)
*nxtp = ip6e.ip6e_nxt;
off += (ip6e.ip6e_len + 2) << 2;
return off;
case IPPROTO_HOPOPTS:
case IPPROTO_ROUTING:
case IPPROTO_DSTOPTS:
if (m->m_pkthdr.len < off + sizeof(ip6e))
return -1;
m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
if (nxtp)
*nxtp = ip6e.ip6e_nxt;
off += (ip6e.ip6e_len + 1) << 3;
return off;
case IPPROTO_NONE:
case IPPROTO_ESP:
case IPPROTO_IPCOMP:
/* give up */
return -1;
default:
return -1;
}
return -1;
}
/*
* get offset for the last header in the chain. m will be kept untainted.
*/
int
ip6_lasthdr(m, off, proto, nxtp)
struct mbuf *m;
int off;
int proto;
int *nxtp;
{
int newoff;
int nxt;
if (!nxtp) {
nxt = -1;
nxtp = &nxt;
}
while (1) {
newoff = ip6_nexthdr(m, off, proto, nxtp);
if (newoff < 0)
return off;
else if (newoff < off)
return -1; /* invalid */
else if (newoff == off)
return newoff;
off = newoff;
proto = *nxtp;
}
}
struct mbuf *
ip6_addaux(m)
struct mbuf *m;
{
struct mbuf *n;
#ifdef DIAGNOSTIC
if (sizeof(struct ip6aux) > MHLEN)
panic("assumption failed on sizeof(ip6aux)");
#endif
n = m_aux_find(m, AF_INET6, -1);
if (n) {
if (n->m_len < sizeof(struct ip6aux)) {
printf("conflicting use of ip6aux");
return NULL;
}
} else {
n = m_aux_add(m, AF_INET6, -1);
n->m_len = sizeof(struct ip6aux);
bzero(mtod(n, caddr_t), n->m_len);
}
return n;
}
struct mbuf *
ip6_findaux(m)
struct mbuf *m;
{
struct mbuf *n;
n = m_aux_find(m, AF_INET6, -1);
if (n && n->m_len < sizeof(struct ip6aux)) {
printf("conflicting use of ip6aux");
n = NULL;
}
return n;
}
void
ip6_delaux(m)
struct mbuf *m;
{
struct mbuf *n;
n = m_aux_find(m, AF_INET6, -1);
if (n)
m_aux_delete(m, n);
}
/*
* System control for IP6
*/
u_char inet6ctlerrmap[PRC_NCMDS] = {
0, 0, 0, 0,
0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
EMSGSIZE, EHOSTUNREACH, 0, 0,
0, 0, 0, 0,
ENOPROTOOPT
};
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