Beispiel #1
0
int
udp6_input(struct mbuf **mp, int *offp, int proto)
{
	struct mbuf *m = *mp;
	struct ip6_hdr *ip6;
	struct udphdr *uh;
	struct inpcb *in6p;
	struct  mbuf *opts = NULL;
	int off = *offp;
	int plen, ulen;
	struct sockaddr_in6 udp_in6;
	struct socket *so;
	struct inpcbinfo *pcbinfo = &udbinfo[0];

	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);

	ip6 = mtod(m, struct ip6_hdr *);

	udp_stat.udps_ipackets++;

	plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
	uh = (struct udphdr *)((caddr_t)ip6 + off);
	ulen = ntohs((u_short)uh->uh_ulen);

	if (plen != ulen) {
		udp_stat.udps_badlen++;
		goto bad;
	}

	/*
	 * Checksum extended UDP header and data.
	 */
	if (uh->uh_sum == 0)
		udp_stat.udps_nosum++;
	else if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
		udp_stat.udps_badsum++;
		goto bad;
	}

	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
		struct	inpcb *last, *marker;

		/*
		 * Deliver a multicast datagram to all sockets
		 * for which the local and remote addresses and ports match
		 * those of the incoming datagram.  This allows more than
		 * one process to receive multicasts on the same port.
		 * (This really ought to be done for unicast datagrams as
		 * well, but that would cause problems with existing
		 * applications that open both address-specific sockets and
		 * a wildcard socket listening to the same port -- they would
		 * end up receiving duplicates of every unicast datagram.
		 * Those applications open the multiple sockets to overcome an
		 * inadequacy of the UDP socket interface, but for backwards
		 * compatibility we avoid the problem here rather than
		 * fixing the interface.  Maybe 4.5BSD will remedy this?)
		 */

		/*
		 * In a case that laddr should be set to the link-local
		 * address (this happens in RIPng), the multicast address
		 * specified in the received packet does not match with
		 * laddr. To cure this situation, the matching is relaxed
		 * if the receiving interface is the same as one specified
		 * in the socket and if the destination multicast address
		 * matches one of the multicast groups specified in the socket.
		 */

		/*
		 * Construct sockaddr format source address.
		 */
		init_sin6(&udp_in6, m); /* general init */
		udp_in6.sin6_port = uh->uh_sport;
		/*
		 * KAME note: traditionally we dropped udpiphdr from mbuf here.
		 */

		/*
		 * Locate pcb(s) for datagram.
		 * (Algorithm copied from raw_intr().)
		 */
		last = NULL;

		marker = in_pcbmarker();

		GET_PCBINFO_TOKEN(pcbinfo);

		LIST_INSERT_HEAD(&pcbinfo->pcblisthead, marker, inp_list);
		while ((in6p = LIST_NEXT(marker, inp_list)) != NULL) {
			LIST_REMOVE(marker, inp_list);
			LIST_INSERT_AFTER(in6p, marker, inp_list);

			if (in6p->inp_flags & INP_PLACEMARKER)
				continue;
			if (!INP_ISIPV6(in6p))
				continue;
			if (in6p->in6p_lport != uh->uh_dport)
				continue;
			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr,
							&ip6->ip6_dst) &&
				    !in6_mcmatch(in6p, &ip6->ip6_dst,
						 m->m_pkthdr.rcvif))
					continue;
			}
			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr,
							&ip6->ip6_src) ||
				   in6p->in6p_fport != uh->uh_sport)
					continue;
			}

			if (last != NULL) {
				struct mbuf *n;

				if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
					/*
					 * KAME NOTE: do not
					 * m_copy(m, offset, ...) above.
					 * ssb_appendaddr() expects M_PKTHDR,
					 * and m_copy() will copy M_PKTHDR
					 * only if offset is 0.
					 */
					so = last->in6p_socket;
					if ((last->in6p_flags & IN6P_CONTROLOPTS) ||
					    (so->so_options & SO_TIMESTAMP)) {
						ip6_savecontrol(last, &opts,
								ip6, n);
					}
					m_adj(n, off + sizeof(struct udphdr));
					lwkt_gettoken(&so->so_rcv.ssb_token);
					if (ssb_appendaddr(&so->so_rcv,
						    (struct sockaddr *)&udp_in6,
						    n, opts) == 0) {
						m_freem(n);
						if (opts)
							m_freem(opts);
						udp_stat.udps_fullsock++;
					} else {
						sorwakeup(so);
					}
					lwkt_reltoken(&so->so_rcv.ssb_token);
					opts = NULL;
				}
			}
			last = in6p;
			/*
			 * Don't look for additional matches if this one does
			 * not have either the SO_REUSEPORT or SO_REUSEADDR
			 * socket options set.  This heuristic avoids searching
			 * through all pcbs in the common case of a non-shared
			 * port.  It assumes that an application will never
			 * clear these options after setting them.
			 */
			if ((last->in6p_socket->so_options &
			     (SO_REUSEPORT | SO_REUSEADDR)) == 0)
				break;
		}
		LIST_REMOVE(marker, inp_list);

		REL_PCBINFO_TOKEN(pcbinfo);

		if (last == NULL) {
			/*
			 * No matching pcb found; discard datagram.
			 * (No need to send an ICMP Port Unreachable
			 * for a broadcast or multicast datgram.)
			 */
			udp_stat.udps_noport++;
			udp_stat.udps_noportmcast++;
			goto bad;
		}
		if (last->in6p_flags & IN6P_CONTROLOPTS
		    || last->in6p_socket->so_options & SO_TIMESTAMP)
			ip6_savecontrol(last, &opts, ip6, m);

		m_adj(m, off + sizeof(struct udphdr));
		so = last->in6p_socket;
		lwkt_gettoken(&so->so_rcv.ssb_token);
		if (ssb_appendaddr(&so->so_rcv, (struct sockaddr *)&udp_in6,
				   m, opts) == 0) {
			udp_stat.udps_fullsock++;
			lwkt_reltoken(&so->so_rcv.ssb_token);
			goto bad;
		}
		sorwakeup(so);
		lwkt_reltoken(&so->so_rcv.ssb_token);
		return IPPROTO_DONE;
	}
	/*
	 * Locate pcb for datagram.
	 */
	in6p = in6_pcblookup_hash(pcbinfo, &ip6->ip6_src, uh->uh_sport,
				  &ip6->ip6_dst, uh->uh_dport, 1,
				  m->m_pkthdr.rcvif);
	if (in6p == NULL) {
		if (log_in_vain) {
			char buf[INET6_ADDRSTRLEN];

			strcpy(buf, ip6_sprintf(&ip6->ip6_dst));
			log(LOG_INFO,
			    "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
			    buf, ntohs(uh->uh_dport),
			    ip6_sprintf(&ip6->ip6_src), ntohs(uh->uh_sport));
		}
		udp_stat.udps_noport++;
		if (m->m_flags & M_MCAST) {
			kprintf("UDP6: M_MCAST is set in a unicast packet.\n");
			udp_stat.udps_noportmcast++;
			goto bad;
		}
		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
		return IPPROTO_DONE;
	}

	/*
	 * Construct sockaddr format source address.
	 * Stuff source address and datagram in user buffer.
	 */
	init_sin6(&udp_in6, m); /* general init */
	udp_in6.sin6_port = uh->uh_sport;
	if (in6p->in6p_flags & IN6P_CONTROLOPTS
	    || in6p->in6p_socket->so_options & SO_TIMESTAMP)
		ip6_savecontrol(in6p, &opts, ip6, m);
	m_adj(m, off + sizeof(struct udphdr));
	so = in6p->in6p_socket;
	lwkt_gettoken(&so->so_rcv.ssb_token);
	if (ssb_appendaddr(&so->so_rcv, (struct sockaddr *)&udp_in6,
			   m, opts) == 0) {
		udp_stat.udps_fullsock++;
		lwkt_reltoken(&so->so_rcv.ssb_token);
		goto bad;
	}
	sorwakeup(so);
	lwkt_reltoken(&so->so_rcv.ssb_token);
	return IPPROTO_DONE;
bad:
	if (m)
		m_freem(m);
	if (opts)
		m_freem(opts);
	return IPPROTO_DONE;
}
Beispiel #2
0
int
udp6_input(struct mbuf **mp, int *offp, int proto)
{
	struct mbuf *m = *mp;
	struct ifnet *ifp;
	struct ip6_hdr *ip6;
	struct udphdr *uh;
	struct inpcb *inp;
	struct inpcbinfo *pcbinfo;
	struct udpcb *up;
	int off = *offp;
	int cscov_partial;
	int plen, ulen;
	struct sockaddr_in6 fromsa;
	struct m_tag *fwd_tag;
	uint16_t uh_sum;
	uint8_t nxt;

	ifp = m->m_pkthdr.rcvif;
	ip6 = mtod(m, struct ip6_hdr *);

#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
	ip6 = mtod(m, struct ip6_hdr *);
	uh = (struct udphdr *)((caddr_t)ip6 + off);
#else
	IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
	if (!uh)
		return (IPPROTO_DONE);
#endif

	UDPSTAT_INC(udps_ipackets);

	/*
	 * Destination port of 0 is illegal, based on RFC768.
	 */
	if (uh->uh_dport == 0)
		goto badunlocked;

	plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
	ulen = ntohs((u_short)uh->uh_ulen);

	nxt = ip6->ip6_nxt;
	cscov_partial = (nxt == IPPROTO_UDPLITE) ? 1 : 0;
	if (nxt == IPPROTO_UDPLITE) {
		/* Zero means checksum over the complete packet. */
		if (ulen == 0)
			ulen = plen;
		if (ulen == plen)
			cscov_partial = 0;
		if ((ulen < sizeof(struct udphdr)) || (ulen > plen)) {
			/* XXX: What is the right UDPLite MIB counter? */
			goto badunlocked;
		}
		if (uh->uh_sum == 0) {
			/* XXX: What is the right UDPLite MIB counter? */
			goto badunlocked;
		}
	} else {
		if ((ulen < sizeof(struct udphdr)) || (plen != ulen)) {
			UDPSTAT_INC(udps_badlen);
			goto badunlocked;
		}
		if (uh->uh_sum == 0) {
			UDPSTAT_INC(udps_nosum);
			goto badunlocked;
		}
	}

	if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID_IPV6) &&
	    !cscov_partial) {
		if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
			uh_sum = m->m_pkthdr.csum_data;
		else
			uh_sum = in6_cksum_pseudo(ip6, ulen, nxt,
			    m->m_pkthdr.csum_data);
		uh_sum ^= 0xffff;
	} else
		uh_sum = in6_cksum_partial(m, nxt, off, plen, ulen);

	if (uh_sum != 0) {
		UDPSTAT_INC(udps_badsum);
		goto badunlocked;
	}

	/*
	 * Construct sockaddr format source address.
	 */
	init_sin6(&fromsa, m);
	fromsa.sin6_port = uh->uh_sport;

	pcbinfo = udp_get_inpcbinfo(nxt);
	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
		struct inpcb *last;
		struct inpcbhead *pcblist;
		struct ip6_moptions *imo;

		INP_INFO_RLOCK(pcbinfo);
		/*
		 * In the event that laddr should be set to the link-local
		 * address (this happens in RIPng), the multicast address
		 * specified in the received packet will not match laddr.  To
		 * handle this situation, matching is relaxed if the
		 * receiving interface is the same as one specified in the
		 * socket and if the destination multicast address matches
		 * one of the multicast groups specified in the socket.
		 */

		/*
		 * KAME note: traditionally we dropped udpiphdr from mbuf
		 * here.  We need udphdr for IPsec processing so we do that
		 * later.
		 */
		pcblist = udp_get_pcblist(nxt);
		last = NULL;
		LIST_FOREACH(inp, pcblist, inp_list) {
			if ((inp->inp_vflag & INP_IPV6) == 0)
				continue;
			if (inp->inp_lport != uh->uh_dport)
				continue;
			if (inp->inp_fport != 0 &&
			    inp->inp_fport != uh->uh_sport)
				continue;
			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
				if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
							&ip6->ip6_dst))
					continue;
			}
			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
				if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
							&ip6->ip6_src) ||
				    inp->inp_fport != uh->uh_sport)
					continue;
			}

			/*
			 * XXXRW: Because we weren't holding either the inpcb
			 * or the hash lock when we checked for a match 
			 * before, we should probably recheck now that the 
			 * inpcb lock is (supposed to be) held.
			 */

			/*
			 * Handle socket delivery policy for any-source
			 * and source-specific multicast. [RFC3678]
			 */
			imo = inp->in6p_moptions;
			if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
				struct sockaddr_in6	 mcaddr;
				int			 blocked;

				INP_RLOCK(inp);

				bzero(&mcaddr, sizeof(struct sockaddr_in6));
				mcaddr.sin6_len = sizeof(struct sockaddr_in6);
				mcaddr.sin6_family = AF_INET6;
				mcaddr.sin6_addr = ip6->ip6_dst;

				blocked = im6o_mc_filter(imo, ifp,
					(struct sockaddr *)&mcaddr,
					(struct sockaddr *)&fromsa);
				if (blocked != MCAST_PASS) {
					if (blocked == MCAST_NOTGMEMBER)
						IP6STAT_INC(ip6s_notmember);
					if (blocked == MCAST_NOTSMEMBER ||
					    blocked == MCAST_MUTED)
						UDPSTAT_INC(udps_filtermcast);
					INP_RUNLOCK(inp); /* XXX */
					continue;
				}

				INP_RUNLOCK(inp);
			}
			if (last != NULL) {
				struct mbuf *n;

				if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
					INP_RLOCK(last);
					UDP_PROBE(receive, NULL, last, ip6,
					    last, uh);
					if (udp6_append(last, n, off, &fromsa))
						goto inp_lost;
					INP_RUNLOCK(last);
				}
			}
			last = inp;
			/*
			 * Don't look for additional matches if this one does
			 * not have either the SO_REUSEPORT or SO_REUSEADDR
			 * socket options set.  This heuristic avoids
			 * searching through all pcbs in the common case of a
			 * non-shared port.  It assumes that an application
			 * will never clear these options after setting them.
			 */
			if ((last->inp_socket->so_options &
			     (SO_REUSEPORT|SO_REUSEADDR)) == 0)
				break;
		}

		if (last == NULL) {
			/*
			 * No matching pcb found; discard datagram.  (No need
			 * to send an ICMP Port Unreachable for a broadcast
			 * or multicast datgram.)
			 */
			UDPSTAT_INC(udps_noport);
			UDPSTAT_INC(udps_noportmcast);
			goto badheadlocked;
		}
		INP_RLOCK(last);
		INP_INFO_RUNLOCK(pcbinfo);
		UDP_PROBE(receive, NULL, last, ip6, last, uh);
		if (udp6_append(last, m, off, &fromsa) == 0) 
			INP_RUNLOCK(last);
	inp_lost:
		return (IPPROTO_DONE);
	}
	/*
	 * Locate pcb for datagram.
	 */

	/*
	 * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
	 */
	if ((m->m_flags & M_IP6_NEXTHOP) &&
	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
		struct sockaddr_in6 *next_hop6;

		next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1);

		/*
		 * Transparently forwarded. Pretend to be the destination.
		 * Already got one like this?
		 */
		inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
		    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
		    INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
		if (!inp) {
			/*
			 * It's new.  Try to find the ambushing socket.
			 * Because we've rewritten the destination address,
			 * any hardware-generated hash is ignored.
			 */
			inp = in6_pcblookup(pcbinfo, &ip6->ip6_src,
			    uh->uh_sport, &next_hop6->sin6_addr,
			    next_hop6->sin6_port ? htons(next_hop6->sin6_port) :
			    uh->uh_dport, INPLOOKUP_WILDCARD |
			    INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif);
		}
		/* Remove the tag from the packet. We don't need it anymore. */
		m_tag_delete(m, fwd_tag);
		m->m_flags &= ~M_IP6_NEXTHOP;
	} else
		inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
		    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
		    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
		    m->m_pkthdr.rcvif, m);
	if (inp == NULL) {
		if (udp_log_in_vain) {
			char ip6bufs[INET6_ADDRSTRLEN];
			char ip6bufd[INET6_ADDRSTRLEN];

			log(LOG_INFO,
			    "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
			    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
			    ntohs(uh->uh_dport),
			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
			    ntohs(uh->uh_sport));
		}
		UDPSTAT_INC(udps_noport);
		if (m->m_flags & M_MCAST) {
			printf("UDP6: M_MCAST is set in a unicast packet.\n");
			UDPSTAT_INC(udps_noportmcast);
			goto badunlocked;
		}
		if (V_udp_blackhole)
			goto badunlocked;
		if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
			goto badunlocked;
		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
		return (IPPROTO_DONE);
	}
	INP_RLOCK_ASSERT(inp);
	up = intoudpcb(inp);
	if (cscov_partial) {
		if (up->u_rxcslen == 0 || up->u_rxcslen > ulen) {
			INP_RUNLOCK(inp);
			m_freem(m);
			return (IPPROTO_DONE);
		}
	}
	UDP_PROBE(receive, NULL, inp, ip6, inp, uh);
	if (udp6_append(inp, m, off, &fromsa) == 0)
		INP_RUNLOCK(inp);
	return (IPPROTO_DONE);

badheadlocked:
	INP_INFO_RUNLOCK(pcbinfo);
badunlocked:
	if (m)
		m_freem(m);
	return (IPPROTO_DONE);
}
Beispiel #3
0
void
ip6_forward(struct mbuf *m, int srcrt)
{
	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
	struct sockaddr_in6 *dst;
	struct rtentry *rt;
	int error = 0, type = 0, code = 0;
	struct mbuf *mcopy = NULL;
	struct ifnet *origifp;	/* maybe unnecessary */
#ifdef IPSEC
	u_int8_t sproto = 0;
	struct m_tag *mtag;
	union sockaddr_union sdst;
	struct tdb_ident *tdbi;
	u_int32_t sspi;
	struct tdb *tdb;
	int s;
#endif /* IPSEC */
	u_int rtableid = 0;

	/*
	 * Do not forward packets to multicast destination (should be handled
	 * by ip6_mforward().
	 * Do not forward packets with unspecified source.  It was discussed
	 * in July 2000, on ipngwg mailing list.
	 */
	if ((m->m_flags & (M_BCAST|M_MCAST)) != 0 ||
	    IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
	    IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) {
		ip6stat.ip6s_cantforward++;
		/* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */
		if (ip6_log_time + ip6_log_interval < time_second) {
			ip6_log_time = time_second;
			log(LOG_DEBUG,
			    "cannot forward "
			    "from %s to %s nxt %d received on %s\n",
			    ip6_sprintf(&ip6->ip6_src),
			    ip6_sprintf(&ip6->ip6_dst),
			    ip6->ip6_nxt,
			    m->m_pkthdr.rcvif->if_xname);
		}
		m_freem(m);
		return;
	}

	if (ip6->ip6_hlim <= IPV6_HLIMDEC) {
		/* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */
		icmp6_error(m, ICMP6_TIME_EXCEEDED,
				ICMP6_TIME_EXCEED_TRANSIT, 0);
		return;
	}
	ip6->ip6_hlim -= IPV6_HLIMDEC;

#if NPF > 0
reroute:
#endif

#ifdef IPSEC
	if (!ipsec_in_use)
		goto done_spd;

	s = splnet();

	/*
	 * Check if there was an outgoing SA bound to the flow
	 * from a transport protocol.
	 */

	/* Do we have any pending SAs to apply ? */
	mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
	if (mtag != NULL) {
#ifdef DIAGNOSTIC
		if (mtag->m_tag_len != sizeof (struct tdb_ident))
			panic("ip6_forward: tag of length %d (should be %d",
			    mtag->m_tag_len, sizeof (struct tdb_ident));
#endif
		tdbi = (struct tdb_ident *)(mtag + 1);
		tdb = gettdb(tdbi->spi, &tdbi->dst, tdbi->proto);
		if (tdb == NULL)
			error = -EINVAL;
		m_tag_delete(m, mtag);
	} else
		tdb = ipsp_spd_lookup(m, AF_INET6, sizeof(struct ip6_hdr),
		    &error, IPSP_DIRECTION_OUT, NULL, NULL);

	if (tdb == NULL) {
	        splx(s);

		if (error == 0) {
		        /*
			 * No IPsec processing required, we'll just send the
			 * packet out.
			 */
		        sproto = 0;

			/* Fall through to routing/multicast handling */
		} else {
		        /*
			 * -EINVAL is used to indicate that the packet should
			 * be silently dropped, typically because we've asked
			 * key management for an SA.
			 */
		        if (error == -EINVAL) /* Should silently drop packet */
				error = 0;

			goto freecopy;
		}
	} else {
		/* Loop detection */
		for (mtag = m_tag_first(m); mtag != NULL;
		    mtag = m_tag_next(m, mtag)) {
			if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
			    mtag->m_tag_id !=
			    PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
				continue;
			tdbi = (struct tdb_ident *)(mtag + 1);
			if (tdbi->spi == tdb->tdb_spi &&
			    tdbi->proto == tdb->tdb_sproto &&
			    !bcmp(&tdbi->dst, &tdb->tdb_dst,
			    sizeof(union sockaddr_union))) {
				splx(s);
				sproto = 0; /* mark as no-IPsec-needed */
				goto done_spd;
			}
		}

	        /* We need to do IPsec */
	        bcopy(&tdb->tdb_dst, &sdst, sizeof(sdst));
		sspi = tdb->tdb_spi;
		sproto = tdb->tdb_sproto;
	        splx(s);
	}

	/* Fall through to the routing/multicast handling code */
 done_spd:
#endif /* IPSEC */

#if NPF > 0
	rtableid = m->m_pkthdr.rdomain;
#endif

	/*
	 * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU -
	 * size of IPv6 + ICMPv6 headers) bytes of the packet in case
	 * we need to generate an ICMP6 message to the src.
	 * Thanks to M_EXT, in most cases copy will not occur.
	 *
	 * It is important to save it before IPsec processing as IPsec
	 * processing may modify the mbuf.
	 */
	mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN));

	dst = &ip6_forward_rt.ro_dst;
	if (!srcrt) {
		/*
		 * ip6_forward_rt.ro_dst.sin6_addr is equal to ip6->ip6_dst
		 */
		if (ip6_forward_rt.ro_rt == 0 ||
		    (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) == 0 ||
		    ip6_forward_rtableid != rtableid) {
			if (ip6_forward_rt.ro_rt) {
				RTFREE(ip6_forward_rt.ro_rt);
				ip6_forward_rt.ro_rt = 0;
			}
			/* this probably fails but give it a try again */
			rtalloc_mpath((struct route *)&ip6_forward_rt,
			    &ip6->ip6_src.s6_addr32[0], rtableid);
			ip6_forward_rtableid = rtableid;
		}

		if (ip6_forward_rt.ro_rt == 0) {
			ip6stat.ip6s_noroute++;
			/* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_noroute) */
			if (mcopy) {
				icmp6_error(mcopy, ICMP6_DST_UNREACH,
					    ICMP6_DST_UNREACH_NOROUTE, 0);
			}
			m_freem(m);
			return;
		}
	} else if (ip6_forward_rt.ro_rt == 0 ||
	   (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) == 0 ||
	   !IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst->sin6_addr) ||
	   ip6_forward_rtableid != rtableid) {
		if (ip6_forward_rt.ro_rt) {
			RTFREE(ip6_forward_rt.ro_rt);
			ip6_forward_rt.ro_rt = 0;
		}
		bzero(dst, sizeof(*dst));
		dst->sin6_len = sizeof(struct sockaddr_in6);
		dst->sin6_family = AF_INET6;
		dst->sin6_addr = ip6->ip6_dst;

		rtalloc_mpath((struct route *)&ip6_forward_rt,
		    &ip6->ip6_src.s6_addr32[0], rtableid);
		ip6_forward_rtableid = rtableid;

		if (ip6_forward_rt.ro_rt == 0) {
			ip6stat.ip6s_noroute++;
			/* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_noroute) */
			if (mcopy) {
				icmp6_error(mcopy, ICMP6_DST_UNREACH,
					    ICMP6_DST_UNREACH_NOROUTE, 0);
			}
			m_freem(m);
			return;
		}
	}
	rt = ip6_forward_rt.ro_rt;

	/*
	 * Scope check: if a packet can't be delivered to its destination
	 * for the reason that the destination is beyond the scope of the
	 * source address, discard the packet and return an icmp6 destination
	 * unreachable error with Code 2 (beyond scope of source address).
	 * [draft-ietf-ipngwg-icmp-v3-00.txt, Section 3.1]
	 */
	if (in6_addr2scopeid(m->m_pkthdr.rcvif, &ip6->ip6_src) !=
	    in6_addr2scopeid(rt->rt_ifp, &ip6->ip6_src)) {
		ip6stat.ip6s_cantforward++;
		ip6stat.ip6s_badscope++;
		in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard);

		if (ip6_log_time + ip6_log_interval < time_second) {
			ip6_log_time = time_second;
			log(LOG_DEBUG,
			    "cannot forward "
			    "src %s, dst %s, nxt %d, rcvif %s, outif %s\n",
			    ip6_sprintf(&ip6->ip6_src),
			    ip6_sprintf(&ip6->ip6_dst),
			    ip6->ip6_nxt,
			    m->m_pkthdr.rcvif->if_xname, rt->rt_ifp->if_xname);
		}
		if (mcopy)
			icmp6_error(mcopy, ICMP6_DST_UNREACH,
				    ICMP6_DST_UNREACH_BEYONDSCOPE, 0);
		m_freem(m);
		goto freert;
	}

#ifdef IPSEC
	/*
	 * Check if the packet needs encapsulation.
	 * ipsp_process_packet will never come back to here.
	 * XXX ipsp_process_packet() calls ip6_output(), and there'll be no
	 * PMTU notification.  is it okay?
	 */
	if (sproto != 0) {
		s = splnet();

#if NPF > 0
		if (pf_test6(PF_OUT, &encif[0].sc_if, &m, NULL) != PF_PASS) {
			splx(s);
			error = EHOSTUNREACH;
			m_freem(m);
			goto senderr;
		}
		if (m == NULL) {
			splx(s);
			goto senderr;
		}
		ip6 = mtod(m, struct ip6_hdr *);
		/*
		 * PF_TAG_REROUTE handling or not...
		 * Packet is entering IPsec so the routing is
		 * already overruled by the IPsec policy.
		 * Until now the change was not reconsidered.
		 * What's the behaviour?
		 */
#endif
		tdb = gettdb(sspi, &sdst, sproto);
		if (tdb == NULL) {
			splx(s);
			error = EHOSTUNREACH;
			m_freem(m);
			goto senderr;	/*XXX*/
		}

		m->m_flags &= ~(M_BCAST | M_MCAST);	/* just in case */

		/* Callee frees mbuf */
		error = ipsp_process_packet(m, tdb, AF_INET6, 0);
		splx(s);
		m_freem(mcopy);
		goto freert;
	}
Beispiel #4
0
/*
 * Kalman filter process
 */
static PyObject *
kf_process(PyObject *self, PyObject *args, PyObject *kws)
{
    MatrixObject *A, *B, *C, *D, *x0, *P0, *Q, *R, *x, *P;
    Float *x_est, *y_est, *P_est;
    PyObject *out, *tmp, *tmp1, *x_est_out, *y_est_out, *P_est_out, *result;
    PyObject *mupdate_callback = NULL, *arglist;
    int i, j, k, n, p, q, datalength;
    MatrixObject *y, *u;

    static char *kwlist[] = {"A", "B", "C", "D", "y", "u", "x0", "P0", "Q", "R", "mupdate_callback", NULL};

    if (!PyArg_ParseTupleAndKeywords(args, kws, "O!O!O!O!O!O!O!O!O!O!|O:set_callback", kwlist,
            &MatrixType, &A,
            &MatrixType, &B,
            &MatrixType, &C,
            &MatrixType, &D,
            &MatrixType, &y,
            &MatrixType, &u,
            &MatrixType, &x0,
            &MatrixType, &P0,
            &MatrixType, &Q,
            &MatrixType, &R,
            &mupdate_callback))
        return NULL;

    if (A->rows != A->cols) {
        PyErr_SetString(PyExc_ValueError, "A must be a square matrix");
        return NULL;
    }

    n = A->rows;
    p = B->cols;
    q = C->rows;

    if (B->rows != n) {
        PyErr_SetString(PyExc_ValueError, "B must be Nxp matrix");
        return NULL;
    }
    if (C->cols != n) {
        PyErr_SetString(PyExc_ValueError, "C must be qxN matrix");
        return NULL;
    }
    if (D->rows != p || D->cols != q) {
        PyErr_SetString(PyExc_ValueError, "D must be pxq matrix");
        return NULL;
    }
    datalength = y->cols;
    if (y->cols != u->cols) {
        PyErr_SetString(PyExc_ValueError, "y and u data lengths does not match");
        return NULL;
    }
    if (y->rows != q) {
        PyErr_SetString(PyExc_ValueError, "y must be qxlength matrix");
        return NULL;
    }
    if (u->rows != p) {
        PyErr_SetString(PyExc_ValueError, "u must be pxlength matrix");
        return NULL;
    }
    if (x0->rows != n || x0->cols != 1) {
        PyErr_SetString(PyExc_ValueError, "x0 must be Nx1 matrix");
        return NULL;
    }
    if (P0->rows != n || P0->cols != n) {
        PyErr_SetString(PyExc_ValueError, "P0 must be NxN matrix");
        return NULL;
    }
    if (Q->rows != n || Q->cols != n) {
        PyErr_SetString(PyExc_ValueError, "Q must be NxN matrix");
        return NULL;
    }
    if (R->rows != q || R->cols != q) {
        PyErr_SetString(PyExc_ValueError, "R must be qxq matrix");
        return NULL;
    }
    if (!PyCallable_Check(mupdate_callback)) {
        if (mupdate_callback != NULL) {
            PyErr_SetString(PyExc_TypeError, "parameter must be callable");
            return NULL;
        }
    }

    x_est = m_new(n, datalength);
    y_est = m_new(n, datalength);
    P_est = m_new(n, n*datalength);

    if (mupdate_callback != NULL) {
        Py_XINCREF(mupdate_callback);  // Add a reference to new callback
        x = matrix_new(n, 1);
        P = matrix_new(n, n);
        // initialize x and P
        m_copy(x->data, x0->data, n, 1);
        m_copy(P->data, P0->data, n, n);

        for (i=0; i<datalength; i++) {
            tick(A->data, B->data, C->data, D->data,
                n, p, q,
                y->data+i*q, u->data+i*p,
                x->data, P->data,
                Q->data, R->data,
                x_est+i*n, y_est+i*q, P_est+i*n*n);
            // copy x and P values into output array
            m_copy(x->data, x_est+i*n, n, 1);
            m_copy(P->data, P_est+i*n*n, n, n);
            // update the matrixes
            arglist = Py_BuildValue("(i, O, O, O, O, O)", i, A, B, C, D, x);
            result = PyEval_CallObject(mupdate_callback, arglist);
            Py_DECREF(arglist);
        }
        Py_DECREF(x);
        Py_DECREF(P);
    } else { // model update not needed
        process(A->data, B->data, C->data, D->data,
                n, p, q, y->data, u->data, x0->data, P0->data, Q->data, R->data, datalength,
                x_est, y_est, P_est);
    }

    // create lists from matrixes
    x_est_out = PyList_New(datalength);
    for (i=0; i<datalength; i++) {
        tmp = PyList_New(n);
        for (j=0; j<n; j++) {
            PyList_SetItem(tmp, j, PyFloat_FromDouble( *(x_est+i*n+j) ));
        }
        PyList_SetItem(x_est_out, i, tmp);
    }
    y_est_out = PyList_New(datalength);
    for (i=0; i<datalength; i++) {
        tmp = PyFloat_FromDouble( *(y_est+i) );
        PyList_SetItem(y_est_out, i, tmp);
    }
    P_est_out = PyList_New(datalength);
    for (i=0; i<datalength; i++) {
        tmp = PyList_New(n);
        for (j=0; j<n; j++) {
            tmp1 = PyList_New(n);
            for (k=0; k<n; k++) {
                PyList_SetItem(tmp1, k, PyFloat_FromDouble( *(x_est+i*n+j*n+k) ));
            }
            PyList_SetItem(tmp, j, tmp1);
        }
        tmp = PyFloat_FromDouble( *(P_est+i) );
        PyList_SetItem(P_est_out, i, tmp);
    }

    m_free(x_est);
    m_free(y_est);
    m_free(P_est);

    out = PyTuple_New(3);
    PyTuple_SetItem(out, 0, x_est_out);
    PyTuple_SetItem(out, 1, y_est_out);
    PyTuple_SetItem(out, 2, P_est_out);
    Py_INCREF(out); // TODO add Py_INCREF every time when returning object from fnc

    return out;
}
Beispiel #5
0
struct mbuf *
ip6_forward(struct mbuf *m, struct route_in6 *ip6forward_rt,
    int srcrt)
{
	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
	struct sockaddr_in6 *dst;
	struct rtentry *rt;
	int error, type = 0, code = 0;
	boolean_t proxy = FALSE;
	struct mbuf *mcopy = NULL;
	struct ifnet *ifp, *rcvifp, *origifp;	/* maybe unnecessary */
	u_int32_t inzone, outzone, len;
	struct in6_addr src_in6, dst_in6;
	uint64_t curtime = net_uptime();
#if IPSEC
	struct secpolicy *sp = NULL;
#endif
	unsigned int ifscope = IFSCOPE_NONE;
#if PF
	struct pf_mtag *pf_mtag;
#endif /* PF */

	/*
	 * In the prefix proxying case, the route to the proxied node normally
	 * gets created by nd6_prproxy_ns_output(), as part of forwarding a
	 * NS (NUD/AR) packet to the proxied node.  In the event that such
	 * packet did not arrive in time before the correct route gets created,
	 * ip6_input() would have performed a rtalloc() which most likely will
	 * create the wrong cloned route; this route points back to the same
	 * interface as the inbound interface, since the parent non-scoped
	 * prefix route points there.  Therefore we check if that is the case
	 * and perform the necessary fixup to get the correct route installed.
	 */
	if (!srcrt && nd6_prproxy &&
	    (rt = ip6forward_rt->ro_rt) != NULL && (rt->rt_flags & RTF_PROXY)) {
		nd6_proxy_find_fwdroute(m->m_pkthdr.rcvif, ip6forward_rt);
		if ((rt = ip6forward_rt->ro_rt) != NULL)
			ifscope = rt->rt_ifp->if_index;
	}

#if PF
	pf_mtag = pf_find_mtag(m);
	if (pf_mtag != NULL && pf_mtag->pftag_rtableid != IFSCOPE_NONE)
		ifscope = pf_mtag->pftag_rtableid;

	/*
	 * If the caller provides a route which is on a different interface
	 * than the one specified for scoped forwarding, discard the route
	 * and do a lookup below.
	 */
	if (ifscope != IFSCOPE_NONE && (rt = ip6forward_rt->ro_rt) != NULL) {
		RT_LOCK(rt);
		if (rt->rt_ifp->if_index != ifscope) {
			RT_UNLOCK(rt);
			ROUTE_RELEASE(ip6forward_rt);
			rt = NULL;
		} else {
			RT_UNLOCK(rt);
		}
	}
#endif /* PF */

#if IPSEC
	/*
	 * Check AH/ESP integrity.
	 */
	/*
	 * Don't increment ip6s_cantforward because this is the check
	 * before forwarding packet actually.
	 */
	if (ipsec_bypass == 0) {
		if (ipsec6_in_reject(m, NULL)) {
			IPSEC_STAT_INCREMENT(ipsec6stat.in_polvio);
			m_freem(m);
			return (NULL);
		}
	}
#endif /*IPSEC*/

	/*
	 * Do not forward packets to multicast destination.
	 * Do not forward packets with unspecified source.  It was discussed
	 * in July 2000, on ipngwg mailing list.
	 */
	if ((m->m_flags & (M_BCAST|M_MCAST)) != 0 ||
	    IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
	    IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) {
		ip6stat.ip6s_cantforward++;
		/* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */
		if (ip6_log_time + ip6_log_interval < curtime) {
			ip6_log_time = curtime;
			log(LOG_DEBUG,
			    "cannot forward "
			    "from %s to %s nxt %d received on %s\n",
			    ip6_sprintf(&ip6->ip6_src),
			    ip6_sprintf(&ip6->ip6_dst),
			    ip6->ip6_nxt,
			    if_name(m->m_pkthdr.rcvif));
		}
		m_freem(m);
		return (NULL);
	}

	if (ip6->ip6_hlim <= IPV6_HLIMDEC) {
		/* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */
		icmp6_error(m, ICMP6_TIME_EXCEEDED,
				ICMP6_TIME_EXCEED_TRANSIT, 0);
		return (NULL);
	}

	/*
	 * See if the destination is a proxied address, and if so pretend
	 * that it's for us.  This is mostly to handle NUD probes against
	 * the proxied addresses.  We filter for ICMPv6 here and will let
	 * icmp6_input handle the rest.
	 */
	if (!srcrt && nd6_prproxy) {
		VERIFY(!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst));
		proxy = nd6_prproxy_isours(m, ip6, ip6forward_rt, ifscope);
		/*
		 * Don't update hop limit while proxying; RFC 4389 4.1.
		 * Also skip IPsec forwarding path processing as this
		 * packet is not to be forwarded.
		 */
		if (proxy)
			goto skip_ipsec;
	}

	ip6->ip6_hlim -= IPV6_HLIMDEC;

	/*
	 * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU -
	 * size of IPv6 + ICMPv6 headers) bytes of the packet in case
	 * we need to generate an ICMP6 message to the src.
	 * Thanks to M_EXT, in most cases copy will not occur.
	 *
	 * It is important to save it before IPsec processing as IPsec
	 * processing may modify the mbuf.
	 */
	mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN));

#if IPSEC
	if (ipsec_bypass != 0)
		goto skip_ipsec;
	/* get a security policy for this packet */
	sp = ipsec6_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, IP_FORWARDING,
	    &error);
	if (sp == NULL) {
		IPSEC_STAT_INCREMENT(ipsec6stat.out_inval);
		ip6stat.ip6s_cantforward++;
		if (mcopy) {
#if 0
			/* XXX: what icmp ? */
#else
			m_freem(mcopy);
#endif
		}
		m_freem(m);
		return (NULL);
	}

	error = 0;

	/* check policy */
	switch (sp->policy) {
	case IPSEC_POLICY_DISCARD:
        case IPSEC_POLICY_GENERATE:
		/*
		 * This packet is just discarded.
		 */
		IPSEC_STAT_INCREMENT(ipsec6stat.out_polvio);
		ip6stat.ip6s_cantforward++;
		key_freesp(sp, KEY_SADB_UNLOCKED);
		if (mcopy) {
#if 0
			/* XXX: what icmp ? */
#else
			m_freem(mcopy);
#endif
		}
		m_freem(m);
		return (NULL);

	case IPSEC_POLICY_BYPASS:
	case IPSEC_POLICY_NONE:
		/* no need to do IPsec. */
		key_freesp(sp, KEY_SADB_UNLOCKED);
		goto skip_ipsec;

	case IPSEC_POLICY_IPSEC:
		if (sp->req == NULL) {
			/* XXX should be panic ? */
			printf("ip6_forward: No IPsec request specified.\n");
			ip6stat.ip6s_cantforward++;
			key_freesp(sp, KEY_SADB_UNLOCKED);
			if (mcopy) {
#if 0
				/* XXX: what icmp ? */
#else
				m_freem(mcopy);
#endif
			}
			m_freem(m);
			return (NULL);
		}
		/* do IPsec */
		break;

	case IPSEC_POLICY_ENTRUST:
	default:
		/* should be panic ?? */
		printf("ip6_forward: Invalid policy found. %d\n", sp->policy);
		key_freesp(sp, KEY_SADB_UNLOCKED);
		goto skip_ipsec;
	}

    {
	struct ipsec_output_state state;

	/*
	 * All the extension headers will become inaccessible
	 * (since they can be encrypted).
	 * Don't panic, we need no more updates to extension headers
	 * on inner IPv6 packet (since they are now encapsulated).
	 *
	 * IPv6 [ESP|AH] IPv6 [extension headers] payload
	 */
	bzero(&state, sizeof(state));
	state.m = m;
	state.dst = NULL;	/* update at ipsec6_output_tunnel() */

	error = ipsec6_output_tunnel(&state, sp, 0);
	key_freesp(sp, KEY_SADB_UNLOCKED);
	if (state.tunneled == 4) {
		ROUTE_RELEASE(&state.ro);
		return (NULL);  /* packet is gone - sent over IPv4 */
	}

	m = state.m;
	ROUTE_RELEASE(&state.ro);

	if (error) {
		/* mbuf is already reclaimed in ipsec6_output_tunnel. */
		switch (error) {
		case EHOSTUNREACH:
		case ENETUNREACH:
		case EMSGSIZE:
		case ENOBUFS:
		case ENOMEM:
			break;
		default:
			printf("ip6_output (ipsec): error code %d\n", error);
			/* fall through */
		case ENOENT:
			/* don't show these error codes to the user */
			break;
		}
		ip6stat.ip6s_cantforward++;
		if (mcopy) {
#if 0
			/* XXX: what icmp ? */
#else
			m_freem(mcopy);
#endif
		}
		m_freem(m);
		return (NULL);
	}
    }
#endif /* IPSEC */
    skip_ipsec:

	dst = (struct sockaddr_in6 *)&ip6forward_rt->ro_dst;
	if ((rt = ip6forward_rt->ro_rt) != NULL) {
		RT_LOCK(rt);
		/* Take an extra ref for ourselves */
		RT_ADDREF_LOCKED(rt);
	}

	VERIFY(rt == NULL || rt == ip6forward_rt->ro_rt);
	if (!srcrt) {
		/*
		 * ip6forward_rt->ro_dst.sin6_addr is equal to ip6->ip6_dst
		 */
		if (ROUTE_UNUSABLE(ip6forward_rt)) {
			if (rt != NULL) {
				/* Release extra ref */
				RT_REMREF_LOCKED(rt);
				RT_UNLOCK(rt);
			}
			ROUTE_RELEASE(ip6forward_rt);

			/* this probably fails but give it a try again */
			rtalloc_scoped_ign((struct route *)ip6forward_rt,
			    RTF_PRCLONING, ifscope);
			if ((rt = ip6forward_rt->ro_rt) != NULL) {
				RT_LOCK(rt);
				/* Take an extra ref for ourselves */
				RT_ADDREF_LOCKED(rt);
			}
		}

		if (rt == NULL) {
			ip6stat.ip6s_noroute++;
			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute);
			if (mcopy)
				icmp6_error(mcopy, ICMP6_DST_UNREACH,
					    ICMP6_DST_UNREACH_NOROUTE, 0);
			m_freem(m);
			return (NULL);
		}
		RT_LOCK_ASSERT_HELD(rt);
	} else if (ROUTE_UNUSABLE(ip6forward_rt) ||
	    !IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst->sin6_addr)) {
		if (rt != NULL) {
			/* Release extra ref */
			RT_REMREF_LOCKED(rt);
			RT_UNLOCK(rt);
		}
		ROUTE_RELEASE(ip6forward_rt);

		bzero(dst, sizeof(*dst));
		dst->sin6_len = sizeof(struct sockaddr_in6);
		dst->sin6_family = AF_INET6;
		dst->sin6_addr = ip6->ip6_dst;

		rtalloc_scoped_ign((struct route *)ip6forward_rt,
		    RTF_PRCLONING, ifscope);
		if ((rt = ip6forward_rt->ro_rt) == NULL) {
			ip6stat.ip6s_noroute++;
			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute);
			if (mcopy)
				icmp6_error(mcopy, ICMP6_DST_UNREACH,
				    ICMP6_DST_UNREACH_NOROUTE, 0);
			m_freem(m);
			return (NULL);
		}
		RT_LOCK(rt);
		/* Take an extra ref for ourselves */
		RT_ADDREF_LOCKED(rt);
	}

	/*
	 * Source scope check: if a packet can't be delivered to its
	 * destination for the reason that the destination is beyond the scope
	 * of the source address, discard the packet and return an icmp6
	 * destination unreachable error with Code 2 (beyond scope of source
	 * address) unless we are proxying (source address is link local
	 * for NUDs.)  We use a local copy of ip6_src, since in6_setscope()
	 * will possibly modify its first argument.
	 * [draft-ietf-ipngwg-icmp-v3-04.txt, Section 3.1]
	 */
	src_in6 = ip6->ip6_src;
	if (in6_setscope(&src_in6, rt->rt_ifp, &outzone)) {
		/* XXX: this should not happen */
		ip6stat.ip6s_cantforward++;
		ip6stat.ip6s_badscope++;
		m_freem(m);
		return (NULL);
	}
	if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) {
		ip6stat.ip6s_cantforward++;
		ip6stat.ip6s_badscope++;
		m_freem(m);
		return (NULL);
	}

	if (inzone != outzone && !proxy) {
		ip6stat.ip6s_cantforward++;
		ip6stat.ip6s_badscope++;
		in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard);

		if (ip6_log_time + ip6_log_interval < curtime) {
			ip6_log_time = curtime;
			log(LOG_DEBUG,
			    "cannot forward "
			    "src %s, dst %s, nxt %d, rcvif %s, outif %s\n",
			    ip6_sprintf(&ip6->ip6_src),
			    ip6_sprintf(&ip6->ip6_dst),
			    ip6->ip6_nxt,
			    if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp));
		}
		/* Release extra ref */
		RT_REMREF_LOCKED(rt);
		RT_UNLOCK(rt);
		if (mcopy) {
			icmp6_error(mcopy, ICMP6_DST_UNREACH,
				    ICMP6_DST_UNREACH_BEYONDSCOPE, 0);
		}
		m_freem(m);
		return (NULL);
	}

	/*
	 * Destination scope check: if a packet is going to break the scope
	 * zone of packet's destination address, discard it.  This case should
	 * usually be prevented by appropriately-configured routing table, but
	 * we need an explicit check because we may mistakenly forward the
	 * packet to a different zone by (e.g.) a default route.
	 */
	dst_in6 = ip6->ip6_dst;
	if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 ||
	    in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 ||
	    inzone != outzone) {
		ip6stat.ip6s_cantforward++;
		ip6stat.ip6s_badscope++;
		m_freem(m);
		return (NULL);
	}

	if (m->m_pkthdr.len > rt->rt_ifp->if_mtu) {
		in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig);
		if (mcopy) {
			uint32_t mtu;
#if IPSEC
			struct secpolicy *sp2;
			int ipsecerror;
			size_t ipsechdrsiz;
#endif

			mtu = rt->rt_ifp->if_mtu;
#if IPSEC
			/*
			 * When we do IPsec tunnel ingress, we need to play
			 * with the link value (decrement IPsec header size
			 * from mtu value).  The code is much simpler than v4
			 * case, as we have the outgoing interface for
			 * encapsulated packet as "rt->rt_ifp".
			 */
			sp2 = ipsec6_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND,
				IP_FORWARDING, &ipsecerror);
			if (sp2) {
				ipsechdrsiz = ipsec6_hdrsiz(mcopy,
					IPSEC_DIR_OUTBOUND, NULL);
				if (ipsechdrsiz < mtu)
					mtu -= ipsechdrsiz;
				key_freesp(sp2, KEY_SADB_UNLOCKED);
			}
			/*
			 * if mtu becomes less than minimum MTU,
			 * tell minimum MTU (and I'll need to fragment it).
			 */
			if (mtu < IPV6_MMTU)
				mtu = IPV6_MMTU;
#endif
			/* Release extra ref */
			RT_REMREF_LOCKED(rt);
			RT_UNLOCK(rt);
			icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu);
		} else {
			/* Release extra ref */
			RT_REMREF_LOCKED(rt);
			RT_UNLOCK(rt);
		}
		m_freem(m);
		return (NULL);
 	}

	if (rt->rt_flags & RTF_GATEWAY)
		dst = (struct sockaddr_in6 *)(void *)rt->rt_gateway;

	/*
	 * If we are to forward the packet using the same interface
	 * as one we got the packet from, perhaps we should send a redirect
	 * to sender to shortcut a hop.
	 * Only send redirect if source is sending directly to us,
	 * and if packet was not source routed (or has any options).
	 * Also, don't send redirect if forwarding using a route
	 * modified by a redirect.
	 */
	if (!proxy &&
	    ip6_sendredirects && rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt &&
	    (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) {
		if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) != 0) {
			/*
			 * If the incoming interface is equal to the outgoing
			 * one, and the link attached to the interface is
			 * point-to-point, then it will be highly probable
			 * that a routing loop occurs. Thus, we immediately
			 * drop the packet and send an ICMPv6 error message.
			 *
			 * type/code is based on suggestion by Rich Draves.
			 * not sure if it is the best pick.
			 */
			RT_REMREF_LOCKED(rt);	/* Release extra ref */
			RT_UNLOCK(rt);
			icmp6_error(mcopy, ICMP6_DST_UNREACH,
				    ICMP6_DST_UNREACH_ADDR, 0);
			m_freem(m);
			return (NULL);
		}
		type = ND_REDIRECT;
	}

#if IPFW2
	/*
	 * Check with the firewall...
	 */
	if (ip6_fw_enable && ip6_fw_chk_ptr) {
		u_short port = 0;
		ifp = rt->rt_ifp;
		/* Drop the lock but retain the extra ref */
		RT_UNLOCK(rt);
		/* If ipfw says divert, we have to just drop packet */
		if (ip6_fw_chk_ptr(&ip6, ifp, &port, &m)) {
			m_freem(m);
			goto freecopy;
		}
		if (!m) {
			goto freecopy;
		}
		/* We still have the extra ref on rt */
		RT_LOCK(rt);
	}
#endif

	/*
	 * Fake scoped addresses. Note that even link-local source or
	 * destinaion can appear, if the originating node just sends the
	 * packet to us (without address resolution for the destination).
	 * Since both icmp6_error and icmp6_redirect_output fill the embedded
	 * link identifiers, we can do this stuff after making a copy for
	 * returning an error.
	 */
	if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) {
		/*
		 * See corresponding comments in ip6_output.
		 * XXX: but is it possible that ip6_forward() sends a packet
		 *      to a loopback interface? I don't think so, and thus
		 *      I bark here. ([email protected])
		 * XXX: it is common to route invalid packets to loopback.
		 *	also, the codepath will be visited on use of ::1 in
		 *	rthdr. (itojun)
		 */
#if 1
		if ((0))
#else
		if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0)
#endif
		{
			printf("ip6_forward: outgoing interface is loopback. "
				"src %s, dst %s, nxt %d, rcvif %s, outif %s\n",
				ip6_sprintf(&ip6->ip6_src),
				ip6_sprintf(&ip6->ip6_dst),
				ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif),
				if_name(rt->rt_ifp));
		}

		/* we can just use rcvif in forwarding. */
		origifp = rcvifp = m->m_pkthdr.rcvif;
	} else if (nd6_prproxy) {
		/*
		 * In the prefix proxying case, we need to inform nd6_output()
		 * about the inbound interface, so that any subsequent NS
		 * packets generated by nd6_prproxy_ns_output() will not be
		 * sent back to that same interface.
		 */
		origifp = rcvifp = m->m_pkthdr.rcvif;
	} else {
		rcvifp = m->m_pkthdr.rcvif;
		origifp = rt->rt_ifp;
	}
	/*
	 * clear embedded scope identifiers if necessary.
	 * in6_clearscope will touch the addresses only when necessary.
	 */
	in6_clearscope(&ip6->ip6_src);
	in6_clearscope(&ip6->ip6_dst);

	ifp = rt->rt_ifp;
	/* Drop the lock but retain the extra ref */
	RT_UNLOCK(rt);

	/*
	 * If this is to be processed locally, let ip6_input have it.
	 */
	if (proxy) {
		VERIFY(m->m_pkthdr.pkt_flags & PKTF_PROXY_DST);
		/* Release extra ref */
		RT_REMREF(rt);
		if (mcopy != NULL)
			m_freem(mcopy);
		return (m);
	}

#if PF
	/* Invoke outbound packet filter */
	error = pf_af_hook(ifp, NULL, &m, AF_INET6, FALSE, NULL);

	if (error != 0 || m == NULL) {
		if (m != NULL) {
			panic("%s: unexpected packet %p\n", __func__, m);
			/* NOTREACHED */
		}
		/* Already freed by callee */
		goto senderr;
	}
	ip6 = mtod(m, struct ip6_hdr *);
#endif /* PF */

	/* Mark this packet as being forwarded from another interface */
	m->m_pkthdr.pkt_flags |= PKTF_FORWARDED;
	len = m_pktlen(m);

	error = nd6_output(ifp, origifp, m, dst, rt, NULL);
	if (error) {
		in6_ifstat_inc(ifp, ifs6_out_discard);
		ip6stat.ip6s_cantforward++;
	} else {
		/*
		 * Increment stats on the source interface; the ones
		 * for destination interface has been taken care of
		 * during output above by virtue of PKTF_FORWARDED.
		 */
		rcvifp->if_fpackets++;
		rcvifp->if_fbytes += len;

		ip6stat.ip6s_forward++;
		in6_ifstat_inc(ifp, ifs6_out_forward);
		if (type)
			ip6stat.ip6s_redirectsent++;
		else {
			if (mcopy) {
				goto freecopy;
			}
		}
	}
#if PF
senderr:
#endif /* PF */
	if (mcopy == NULL) {
		/* Release extra ref */
		RT_REMREF(rt);
		return (NULL);
	}
	switch (error) {
	case 0:
#if 1
		if (type == ND_REDIRECT) {
			icmp6_redirect_output(mcopy, rt);
			/* Release extra ref */
			RT_REMREF(rt);
			return (NULL);
		}
#endif
		goto freecopy;

	case EMSGSIZE:
		/* xxx MTU is constant in PPP? */
		goto freecopy;

	case ENOBUFS:
		/* Tell source to slow down like source quench in IP? */
		goto freecopy;

	case ENETUNREACH:	/* shouldn't happen, checked above */
	case EHOSTUNREACH:
	case ENETDOWN:
	case EHOSTDOWN:
	default:
		type = ICMP6_DST_UNREACH;
		code = ICMP6_DST_UNREACH_ADDR;
		break;
	}
	icmp6_error(mcopy, type, code, 0);
	/* Release extra ref */
	RT_REMREF(rt);
	return (NULL);

 freecopy:
	m_freem(mcopy);
	/* Release extra ref */
	RT_REMREF(rt);
	return (NULL);
}
/*
 * IP output.  The packet in mbuf chain m contains a skeletal IP
 * header (with len, off, ttl, proto, tos, src, dst).
 * The mbuf chain containing the packet will be freed.
 * The mbuf opt, if present, will not be freed.
 */
int ip_output(struct socket *so, struct mbuf *m0)
{
	Slirp *slirp = m0->slirp;
	register struct ip *ip;
	register struct mbuf *m = m0;
	register int hlen = sizeof(struct ip );
	int len, off, error = 0;

	DEBUG_SLIRP("ip_output(%s, %s)\n", slirp_ptr_so(so), slirp_ptr_mbuf(m0));

	ip = mtod(m, struct ip *);
	/*
	 * Fill in IP header.
	 */
	ip->ip_v = IPVERSION;
	ip->ip_off &= IP_DF;
	ip->ip_id = htons(slirp->ip_id++);
	ip->ip_hl = hlen >> 2;

	/*
	 * If small enough for interface, can just send directly.
	 */
	if ((uint16_t)ip->ip_len <= IF_MTU) {
		ip->ip_len = htons((uint16_t)ip->ip_len);
		ip->ip_off = htons((uint16_t)ip->ip_off);
		ip->ip_sum = 0;
		ip->ip_sum = cksum(m, hlen);

		if_output(so, m);
		goto done;
	}

    DEBUG_SLIRP("ip_output - too large for one packet\n");
    /*
	 * Too large for interface; fragment if possible.
	 * Must be able to put at least 8 bytes per fragment.
	 */
	if (ip->ip_off & IP_DF) {
		error = -1;
		goto bad;
	}

	len = (IF_MTU - hlen) &~ 7;       /* ip databytes per packet */
	if (len < 8) {
		error = -1;
		goto bad;
	}

    {
        int mhlen, firstlen = len;
        struct mbuf **mnext = &m->m_nextpkt;

        /*
         * Loop through length of segment after first fragment,
         * make new header and copy data of each part and link onto chain.
         */
        m0 = m;
        mhlen = sizeof (struct ip);
        int count = 1;
        for (off = hlen + len; off < (uint16_t)ip->ip_len; off += len) {
            DEBUG_SLIRP("ip_output fragment %d\n", count);
            register struct ip *mhip;
            m = m_get(slirp);
            m->m_nextpkt = NULL;
            if (m == NULL) {
                error = -1;
                goto sendorfree;
            }
            m->m_data += IF_MAXLINKHDR;
            mhip = mtod(m, struct ip *);
            *mhip = *ip;

            m->m_len = mhlen;
            mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF);
            if (ip->ip_off & IP_MF)
                mhip->ip_off |= IP_MF;
            if (off + len >= (uint16_t)ip->ip_len)
                len = (uint16_t)ip->ip_len - off;
            else
                mhip->ip_off |= IP_MF;

            mhip->ip_len = htons((uint16_t)(len + mhlen));

            if (m_copy(m, m0, off, len) < 0) {
                error = -1;
                goto sendorfree;
            }

            mhip->ip_off = htons((uint16_t)mhip->ip_off);
            mhip->ip_sum = 0;
            mhip->ip_sum = cksum(m, mhlen);
            *mnext = m;
            mnext = &m->m_nextpkt;
            count++;
        }
        /*
         * Update first fragment by trimming what's been copied out
         * and updating header, then send each fragment (in order).
         */
        m = m0;
        m_adj(m, hlen + firstlen - (uint16_t)ip->ip_len);
        ip->ip_len = htons((uint16_t)m->m_len);
        ip->ip_off = htons((uint16_t)(ip->ip_off | IP_MF));
        ip->ip_sum = 0;
        ip->ip_sum = cksum(m, hlen);
    sendorfree:
        for (m = m0; m; m = m0) {
            DEBUG_SLIRP("ip_output loop(%s)\n", slirp_ptr_mbuf(m));
            m0 = m->m_nextpkt;
            m->m_nextpkt = NULL;
            if (error == 0)
                if_output(so, m);
            else
                m_free(m);
        }
    }

done:
	return error;

bad:
	m_free(m0);
	goto done;
	return error;
}
Beispiel #7
0
/*
 * ARCnet output routine.
 * Encapsulate a packet of type family for the local net.
 * Assumes that ifp is actually pointer to arccom structure.
 */
int
arc_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
    struct route *ro)
{
	struct arc_header	*ah;
	int			error;
	u_int8_t		atype, adst;
	int			loop_copy = 0;
	int			isphds;
#if defined(INET) || defined(INET6)
	struct llentry		*lle;
#endif

	if (!((ifp->if_flags & IFF_UP) &&
	    (ifp->if_drv_flags & IFF_DRV_RUNNING)))
		return(ENETDOWN); /* m, m1 aren't initialized yet */

	error = 0;

	switch (dst->sa_family) {
#ifdef INET
	case AF_INET:

		/*
		 * For now, use the simple IP addr -> ARCnet addr mapping
		 */
		if (m->m_flags & (M_BCAST|M_MCAST))
			adst = arcbroadcastaddr; /* ARCnet broadcast address */
		else if (ifp->if_flags & IFF_NOARP)
			adst = ntohl(SIN(dst)->sin_addr.s_addr) & 0xFF;
		else {
			error = arpresolve(ifp, ro ? ro->ro_rt : NULL,
			                   m, dst, &adst, &lle);
			if (error)
				return (error == EWOULDBLOCK ? 0 : error);
		}

		atype = (ifp->if_flags & IFF_LINK0) ?
			ARCTYPE_IP_OLD : ARCTYPE_IP;
		break;
	case AF_ARP:
	{
		struct arphdr *ah;
		ah = mtod(m, struct arphdr *);
		ah->ar_hrd = htons(ARPHRD_ARCNET);

		loop_copy = -1; /* if this is for us, don't do it */

		switch(ntohs(ah->ar_op)) {
		case ARPOP_REVREQUEST:
		case ARPOP_REVREPLY:
			atype = ARCTYPE_REVARP;
			break;
		case ARPOP_REQUEST:
		case ARPOP_REPLY:
		default:
			atype = ARCTYPE_ARP;
			break;
		}

		if (m->m_flags & M_BCAST)
			bcopy(ifp->if_broadcastaddr, &adst, ARC_ADDR_LEN);
		else
			bcopy(ar_tha(ah), &adst, ARC_ADDR_LEN);
        
	}
	break;
#endif
#ifdef INET6
	case AF_INET6:
		error = nd6_storelladdr(ifp, m, dst, (u_char *)&adst, &lle);
		if (error)
			return (error);
		atype = ARCTYPE_INET6;
		break;
#endif
#ifdef IPX
	case AF_IPX:
		adst = SIPX(dst)->sipx_addr.x_host.c_host[5];
		atype = ARCTYPE_IPX;
		if (adst == 0xff)
			adst = arcbroadcastaddr;
		break;
#endif

	case AF_UNSPEC:
	    {
		const struct arc_header *ah;

		loop_copy = -1;
		ah = (const struct arc_header *)dst->sa_data;
		adst = ah->arc_dhost;
		atype = ah->arc_type;

		if (atype == ARCTYPE_ARP) {
			atype = (ifp->if_flags & IFF_LINK0) ?
			    ARCTYPE_ARP_OLD: ARCTYPE_ARP;

#ifdef ARCNET_ALLOW_BROKEN_ARP
			/*
			 * XXX It's not clear per RFC826 if this is needed, but
			 * "assigned numbers" say this is wrong.
			 * However, e.g., AmiTCP 3.0Beta used it... we make this
			 * switchable for emergency cases. Not perfect, but...
			 */
			if (ifp->if_flags & IFF_LINK2)
				mtod(m, struct arphdr *)->ar_pro = atype - 1;
#endif
		}
		break;
	    }
	default:
		if_printf(ifp, "can't handle af%d\n", dst->sa_family);
		senderr(EAFNOSUPPORT);
	}

	isphds = arc_isphds(atype);
	M_PREPEND(m, isphds ? ARC_HDRNEWLEN : ARC_HDRLEN, M_NOWAIT);
	if (m == 0)
		senderr(ENOBUFS);
	ah = mtod(m, struct arc_header *);
	ah->arc_type = atype;
	ah->arc_dhost = adst;
	ah->arc_shost = ARC_LLADDR(ifp);
	if (isphds) {
		ah->arc_flag = 0;
		ah->arc_seqid = 0;
	}

	if ((ifp->if_flags & IFF_SIMPLEX) && (loop_copy != -1)) {
		if ((m->m_flags & M_BCAST) || (loop_copy > 0)) {
			struct mbuf *n = m_copy(m, 0, (int)M_COPYALL);

			(void) if_simloop(ifp, n, dst->sa_family, ARC_HDRLEN);
		} else if (ah->arc_dhost == ah->arc_shost) {
			(void) if_simloop(ifp, m, dst->sa_family, ARC_HDRLEN);
			return (0);     /* XXX */
		}
	}

	BPF_MTAP(ifp, m);

	error = ifp->if_transmit(ifp, m);

	return (error);

bad:
	if (m)
		m_freem(m);
	return (error);
}
Beispiel #8
0
/*
 * IPX input routine.  Pass to next level.
 */
void
ipxintr()
{
    struct ipx *ipx;
    struct mbuf *m;
    struct ipxpcb *ipxp;
    struct ipx_ifaddr *ia;
    int len, s;

next:
    /*
     * Get next datagram off input queue and get IPX header
     * in first mbuf.
     */
    s = splimp();
    IF_DEQUEUE(&ipxintrq, m);
    splx(s);
    if (m == NULL) {
        return;
    }

    ipxstat.ipxs_total++;

    if ((m->m_flags & M_EXT || m->m_len < sizeof(struct ipx)) &&
            (m = m_pullup(m, sizeof(struct ipx))) == 0) {
        ipxstat.ipxs_toosmall++;
        goto next;
    }

    /*
     * Give any raw listeners a crack at the packet
     */
    for (ipxp = ipxrawcbtable.ipxpt_queue.cqh_first;
            ipxp != (struct ipxpcb *)&ipxrawcbtable.ipxpt_queue;
            ipxp = ipxp->ipxp_queue.cqe_next) {
        struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL);
        if (m1)
            ipx_input(m1, ipxp);
    }

    ipx = mtod(m, struct ipx *);
    len = ntohs(ipx->ipx_len);
    /*
     * Check that the amount of data in the buffers
     * is as at least much as the IPX header would have us expect.
     * Trim mbufs if longer than we expect.
     * Drop packet if shorter than we expect.
     */
    if (m->m_pkthdr.len < len) {
        ipxstat.ipxs_tooshort++;
        goto bad;
    }
    if (m->m_pkthdr.len > len) {
        if (m->m_len == m->m_pkthdr.len) {
            m->m_len = len;
            m->m_pkthdr.len = len;
        } else
            m_adj(m, len - m->m_pkthdr.len);
    }
    if (ipxcksum && ipx->ipx_sum != 0xffff) {
        if (ipx->ipx_sum != ipx_cksum(m, len)) {
            ipxstat.ipxs_badsum++;
            goto bad;
        }
    }

    /*
     * Propagated (Netbios) packets (type 20) has to be handled
     * different. :-(
     */
    if (ipx->ipx_pt == IPXPROTO_NETBIOS) {
        if (ipxnetbios) {
            ipx_output_type20(m);
            goto next;
        } else
            goto bad;
    }

    /*
     * Is this a directed broadcast?
     */
    if (ipx_hosteqnh(ipx_broadhost,ipx->ipx_dna.ipx_host)) {
        if ((!ipx_neteq(ipx->ipx_dna, ipx->ipx_sna)) &&
                (!ipx_neteqnn(ipx->ipx_dna.ipx_net, ipx_broadnet)) &&
                (!ipx_neteqnn(ipx->ipx_sna.ipx_net, ipx_zeronet)) &&
                (!ipx_neteqnn(ipx->ipx_dna.ipx_net, ipx_zeronet)) ) {
            /*
             * If it is a broadcast to the net where it was
             * received from, treat it as ours.
             */
            for (ia = ipx_ifaddr.tqh_first; ia;
                    ia = ia->ia_list.tqe_next)
                if((ia->ia_ifa.ifa_ifp == m->m_pkthdr.rcvif) &&
                        ipx_neteq(ia->ia_addr.sipx_addr,
                                  ipx->ipx_dna))
                    goto ours;

            /*
             * Look to see if I need to eat this packet.
             * Algorithm is to forward all young packets
             * and prematurely age any packets which will
             * by physically broadcasted.
             * Any very old packets eaten without forwarding
             * would die anyway.
             *
             * Suggestion of Bill Nesheim, Cornell U.
             */
            if (ipx->ipx_tc < IPX_MAXHOPS) {
                ipx_forward(m);
                goto next;
            }
        }
        /*
         * Is this our packet? If not, forward.
         */
    } else {
        for (ia = ipx_ifaddr.tqh_first; ia; ia = ia->ia_list.tqe_next)
            if (ipx_hosteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) &&
                    (ipx_neteq(ipx->ipx_dna, ia->ia_addr.sipx_addr) ||
                     ipx_neteqnn(ipx->ipx_dna.ipx_net, ipx_zeronet)))
                break;

        if (ia == NULL) {
            ipx_forward(m);
            goto next;
        }
    }
ours:
    /*
     * Locate pcb for datagram.
     */
    ipxp = ipx_pcblookup(&ipx->ipx_sna, ipx->ipx_dna.ipx_port,
                         IPX_WILDCARD);
    /*
     * Switch out to protocol's input routine.
     */
    if (ipxp) {
        ipxstat.ipxs_delivered++;
        if ((ipxp->ipxp_flags & IPXP_ALL_PACKETS) == 0)
            switch (ipx->ipx_pt) {

            case IPXPROTO_SPX:
                spx_input(m, ipxp);
                goto next;
            }
        ipx_input(m, ipxp);
    } else
        goto bad;

    goto next;

bad:
    m_freem(m);
    goto next;
}