Exemplo n.º 1
0
void
mbuf_del_drvaux(mbuf_t mbuf)
{
	struct m_tag *tag;

	if (mbuf == NULL || !(mbuf->m_flags & M_PKTHDR))
		return;

	if ((tag = m_tag_locate(mbuf, KERNEL_MODULE_TAG_ID,
	    KERNEL_TAG_TYPE_DRVAUX, NULL)) != NULL)
		m_tag_delete(mbuf, tag);
}
Exemplo n.º 2
0
/*
 * Retrieve incoming source route for use in replies, in the same form used
 * by setsockopt.  The first hop is placed before the options, will be
 * removed later.
 */
struct mbuf *
ip_srcroute(struct mbuf *m0)
{
	struct in_addr *p, *q;
	struct mbuf *m;
	struct ipopt_tag *opts;

	opts = (struct ipopt_tag *)m_tag_find(m0, PACKET_TAG_IPOPTIONS, NULL);
	if (opts == NULL)
		return (NULL);

	if (opts->ip_nhops == 0)
		return (NULL);
	m = m_get(M_DONTWAIT, MT_DATA);
	if (m == NULL)
		return (NULL);

#define OPTSIZ	(sizeof(opts->ip_srcrt.nop) + sizeof(opts->ip_srcrt.srcopt))

	/* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
	m->m_len = opts->ip_nhops * sizeof(struct in_addr) +
	    sizeof(struct in_addr) + OPTSIZ;

	/*
	 * First, save first hop for return route.
	 */
	p = &(opts->ip_srcrt.route[opts->ip_nhops - 1]);
	*(mtod(m, struct in_addr *)) = *p--;

	/*
	 * Copy option fields and padding (nop) to mbuf.
	 */
	opts->ip_srcrt.nop = IPOPT_NOP;
	opts->ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
	(void)memcpy(mtod(m, caddr_t) + sizeof(struct in_addr),
	    &(opts->ip_srcrt.nop), OPTSIZ);
	q = (struct in_addr *)(mtod(m, caddr_t) +
	    sizeof(struct in_addr) + OPTSIZ);
#undef OPTSIZ
	/*
	 * Record return path as an IP source route, reversing the path
	 * (pointers are now aligned).
	 */
	while (p >= opts->ip_srcrt.route) {
		*q++ = *p--;
	}
	/*
	 * Last hop goes to final destination.
	 */
	*q = opts->ip_srcrt.dst;
	m_tag_delete(m0, (struct m_tag *)opts);
	return (m);
}
Exemplo n.º 3
0
void *
encap_getarg(struct mbuf *m)
{
	struct m_tag	*tag;
	struct encaptabtag *et;
	void *p = NULL;
	
	tag = m_tag_locate(m, KERNEL_MODULE_TAG_ID, KERNEL_TAG_TYPE_ENCAP, NULL);
	if (tag) {
		et = (struct encaptabtag*)(tag + 1);
		p = et->arg;
		m_tag_delete(m, tag);
	}
	
	return p;
}
Exemplo n.º 4
0
void
mbuf_tag_free(
	mbuf_t			mbuf,
	mbuf_tag_id_t	id,
	mbuf_tag_type_t	type)
{
	struct m_tag *tag;
	u_int32_t mtag_id_first, mtag_id_last;

	/* Sanity check parameters */
	(void) net_str_id_first_last(&mtag_id_first, &mtag_id_last,
	    NSI_MBUF_TAG);
	if (mbuf == NULL || (mbuf->m_flags & M_PKTHDR) == 0 ||
	    id < mtag_id_first || id > mtag_id_last)
		return;

	tag = m_tag_locate(mbuf, id, type, NULL);
	if (tag == NULL) {
		return;
	}

	m_tag_delete(mbuf, tag);
}
Exemplo n.º 5
0
void
udp_input(struct mbuf *m, int off)
{
	int iphlen = off;
	struct ip *ip;
	struct udphdr *uh;
	struct ifnet *ifp;
	struct inpcb *inp;
	uint16_t len, ip_len;
	struct inpcbinfo *pcbinfo;
	struct ip save_ip;
	struct sockaddr_in udp_in;
	struct m_tag *fwd_tag;
	int cscov_partial;
	uint8_t pr;

	ifp = m->m_pkthdr.rcvif;
	UDPSTAT_INC(udps_ipackets);

	/*
	 * Strip IP options, if any; should skip this, make available to
	 * user, and use on returned packets, but we don't yet have a way to
	 * check the checksum with options still present.
	 */
	if (iphlen > sizeof (struct ip)) {
		ip_stripoptions(m);
		iphlen = sizeof(struct ip);
	}

	/*
	 * Get IP and UDP header together in first mbuf.
	 */
	ip = mtod(m, struct ip *);
	if (m->m_len < iphlen + sizeof(struct udphdr)) {
		if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == NULL) {
			UDPSTAT_INC(udps_hdrops);
			return;
		}
		ip = mtod(m, struct ip *);
	}
	uh = (struct udphdr *)((caddr_t)ip + iphlen);
	pr = ip->ip_p;
	cscov_partial = (pr == IPPROTO_UDPLITE) ? 1 : 0;

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

	/*
	 * Construct sockaddr format source address.  Stuff source address
	 * and datagram in user buffer.
	 */
	bzero(&udp_in, sizeof(udp_in));
	udp_in.sin_len = sizeof(udp_in);
	udp_in.sin_family = AF_INET;
	udp_in.sin_port = uh->uh_sport;
	udp_in.sin_addr = ip->ip_src;

	/*
	 * Make mbuf data length reflect UDP length.  If not enough data to
	 * reflect UDP length, drop.
	 */
	len = ntohs((u_short)uh->uh_ulen);
	ip_len = ntohs(ip->ip_len) - iphlen;
	if (pr == IPPROTO_UDPLITE && len == 0) {
		/* Zero means checksum over the complete packet. */
		len = ip_len;
		cscov_partial = 0;
	}
	if (ip_len != len) {
		if (len > ip_len || len < sizeof(struct udphdr)) {
			UDPSTAT_INC(udps_badlen);
			goto badunlocked;
		}
		if (pr == IPPROTO_UDP)
			m_adj(m, len - ip_len);
	}

	/*
	 * Save a copy of the IP header in case we want restore it for
	 * sending an ICMP error message in response.
	 */
	if (!V_udp_blackhole)
		save_ip = *ip;
	else
		memset(&save_ip, 0, sizeof(save_ip));

	/*
	 * Checksum extended UDP header and data.
	 */
	if (uh->uh_sum) {
		u_short uh_sum;

		if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID) &&
		    !cscov_partial) {
			if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
				uh_sum = m->m_pkthdr.csum_data;
			else
				uh_sum = in_pseudo(ip->ip_src.s_addr,
				    ip->ip_dst.s_addr, htonl((u_short)len +
				    m->m_pkthdr.csum_data + pr));
			uh_sum ^= 0xffff;
		} else {
			char b[9];

			bcopy(((struct ipovly *)ip)->ih_x1, b, 9);
			bzero(((struct ipovly *)ip)->ih_x1, 9);
			((struct ipovly *)ip)->ih_len = (pr == IPPROTO_UDP) ?
			    uh->uh_ulen : htons(ip_len);
			uh_sum = in_cksum(m, len + sizeof (struct ip));
			bcopy(b, ((struct ipovly *)ip)->ih_x1, 9);
		}
		if (uh_sum) {
			UDPSTAT_INC(udps_badsum);
			m_freem(m);
			return;
		}
	} else
		UDPSTAT_INC(udps_nosum);

	pcbinfo = get_inpcbinfo(pr);
	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
	    in_broadcast(ip->ip_dst, ifp)) {
		struct inpcb *last;
		struct inpcbhead *pcblist;
		struct ip_moptions *imo;

		INP_INFO_RLOCK(pcbinfo);
		pcblist = get_pcblist(pr);
		last = NULL;
		LIST_FOREACH(inp, pcblist, inp_list) {
			if (inp->inp_lport != uh->uh_dport)
				continue;
#ifdef INET6
			if ((inp->inp_vflag & INP_IPV4) == 0)
				continue;
#endif
			if (inp->inp_laddr.s_addr != INADDR_ANY &&
			    inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
				continue;
			if (inp->inp_faddr.s_addr != INADDR_ANY &&
			    inp->inp_faddr.s_addr != ip->ip_src.s_addr)
				continue;
			if (inp->inp_fport != 0 &&
			    inp->inp_fport != uh->uh_sport)
				continue;

			INP_RLOCK(inp);

			/*
			 * 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 held.
			 */

			/*
			 * Handle socket delivery policy for any-source
			 * and source-specific multicast. [RFC3678]
			 */
			imo = inp->inp_moptions;
			if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
				struct sockaddr_in	 group;
				int			 blocked;
				if (imo == NULL) {
					INP_RUNLOCK(inp);
					continue;
				}
				bzero(&group, sizeof(struct sockaddr_in));
				group.sin_len = sizeof(struct sockaddr_in);
				group.sin_family = AF_INET;
				group.sin_addr = ip->ip_dst;

				blocked = imo_multi_filter(imo, ifp,
					(struct sockaddr *)&group,
					(struct sockaddr *)&udp_in);
				if (blocked != MCAST_PASS) {
					if (blocked == MCAST_NOTGMEMBER)
						IPSTAT_INC(ips_notmember);
					if (blocked == MCAST_NOTSMEMBER ||
					    blocked == MCAST_MUTED)
						UDPSTAT_INC(udps_filtermcast);
					INP_RUNLOCK(inp);
					continue;
				}
			}
			if (last != NULL) {
				struct mbuf *n;

				n = m_copy(m, 0, M_COPYALL);
				udp_append(last, ip, n, iphlen, &udp_in);
				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_noportbcast);
			if (inp)
				INP_RUNLOCK(inp);
			INP_INFO_RUNLOCK(pcbinfo);
			goto badunlocked;
		}
		udp_append(last, ip, m, iphlen, &udp_in);
		INP_RUNLOCK(last);
		INP_INFO_RUNLOCK(pcbinfo);
		return;
	}

	/*
	 * Locate pcb for datagram.
	 */

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

		next_hop = (struct sockaddr_in *)(fwd_tag + 1);

		/*
		 * Transparently forwarded. Pretend to be the destination.
		 * Already got one like this?
		 */
		inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
		    ip->ip_dst, uh->uh_dport, INPLOOKUP_RLOCKPCB, ifp, 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 = in_pcblookup(pcbinfo, ip->ip_src,
			    uh->uh_sport, next_hop->sin_addr,
			    next_hop->sin_port ? htons(next_hop->sin_port) :
			    uh->uh_dport, INPLOOKUP_WILDCARD |
			    INPLOOKUP_RLOCKPCB, ifp);
		}
		/* Remove the tag from the packet. We don't need it anymore. */
		m_tag_delete(m, fwd_tag);
		m->m_flags &= ~M_IP_NEXTHOP;
	} else
		inp = in_pcblookup_mbuf(pcbinfo, ip->ip_src, uh->uh_sport,
		    ip->ip_dst, uh->uh_dport, INPLOOKUP_WILDCARD |
		    INPLOOKUP_RLOCKPCB, ifp, m);
	if (inp == NULL) {
		if (udp_log_in_vain) {
			char buf[4*sizeof "123"];

			strcpy(buf, inet_ntoa(ip->ip_dst));
			log(LOG_INFO,
			    "Connection attempt to UDP %s:%d from %s:%d\n",
			    buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
			    ntohs(uh->uh_sport));
		}
		UDPSTAT_INC(udps_noport);
		if (m->m_flags & (M_BCAST | M_MCAST)) {
			UDPSTAT_INC(udps_noportbcast);
			goto badunlocked;
		}
		if (V_udp_blackhole)
			goto badunlocked;
		if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
			goto badunlocked;
		*ip = save_ip;
		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
		return;
	}

	/*
	 * Check the minimum TTL for socket.
	 */
	INP_RLOCK_ASSERT(inp);
	if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl) {
		INP_RUNLOCK(inp);
		m_freem(m);
		return;
	}
	if (cscov_partial) {
		struct udpcb *up;

		up = intoudpcb(inp);
		if (up->u_rxcslen > len) {
			INP_RUNLOCK(inp);
			m_freem(m);
			return;
		}
	}

	UDP_PROBE(receive, NULL, inp, ip, inp, uh);
	udp_append(inp, ip, m, iphlen, &udp_in);
	INP_RUNLOCK(inp);
	return;

badunlocked:
	m_freem(m);
}
Exemplo n.º 6
0
/*
 * Forward a packet.  If some error occurs return the sender
 * an icmp packet.  Note we can't always generate a meaningful
 * icmp message because icmp doesn't have a large enough repertoire
 * of codes and types.
 *
 * If not forwarding, just drop the packet.  This could be confusing
 * if ipforwarding was zero but some routing protocol was advancing
 * us as a gateway to somewhere.  However, we must let the routing
 * protocol deal with that.
 *
 */
void
ip6_forward(struct mbuf *m, int srcrt)
{
	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
	struct sockaddr_in6 *dst = NULL;
	struct rtentry *rt = NULL;
	struct route_in6 rin6;
	int error, type = 0, code = 0;
	struct mbuf *mcopy = NULL;
	struct ifnet *origifp;	/* maybe unnecessary */
	u_int32_t inzone, outzone;
	struct in6_addr src_in6, dst_in6, odst;
	struct m_tag *fwd_tag;
	char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];

	/*
	 * 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 the 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_INC(ip6s_cantforward);
		/* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */
		if (V_ip6_log_time + V_ip6_log_interval < time_uptime) {
			V_ip6_log_time = time_uptime;
			log(LOG_DEBUG,
			    "cannot forward "
			    "from %s to %s nxt %d received on %s\n",
			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
			    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
			    ip6->ip6_nxt,
			    if_name(m->m_pkthdr.rcvif));
		}
		m_freem(m);
		return;
	}

	if (
#ifdef IPSTEALTH
	    V_ip6stealth == 0 &&
#endif
	    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;
	}

	/*
	 * 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_copym(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN),
	    M_NOWAIT);
#ifdef IPSTEALTH
	if (V_ip6stealth == 0)
#endif
		ip6->ip6_hlim -= IPV6_HLIMDEC;

#if defined(IPSEC) || defined(IPSEC_SUPPORT)
	if (IPSEC_ENABLED(ipv6)) {
		if ((error = IPSEC_FORWARD(ipv6, m)) != 0) {
			/* mbuf consumed by IPsec */
			m_freem(mcopy);
			if (error != EINPROGRESS)
				IP6STAT_INC(ip6s_cantforward);
			return;
		}
		/* No IPsec processing required */
	}
#endif
again:
	bzero(&rin6, sizeof(struct route_in6));
	dst = (struct sockaddr_in6 *)&rin6.ro_dst;
	dst->sin6_len = sizeof(struct sockaddr_in6);
	dst->sin6_family = AF_INET6;
	dst->sin6_addr = ip6->ip6_dst;
again2:
	rin6.ro_rt = in6_rtalloc1((struct sockaddr *)dst, 0, 0, M_GETFIB(m));
	rt = rin6.ro_rt;
	if (rin6.ro_rt != NULL)
		RT_UNLOCK(rin6.ro_rt);
	else {
		IP6STAT_INC(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);
		}
		goto bad;
	}

	/*
	 * 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).  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_INC(ip6s_cantforward);
		IP6STAT_INC(ip6s_badscope);
		goto bad;
	}
	if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) {
		IP6STAT_INC(ip6s_cantforward);
		IP6STAT_INC(ip6s_badscope);
		goto bad;
	}
	if (inzone != outzone) {
		IP6STAT_INC(ip6s_cantforward);
		IP6STAT_INC(ip6s_badscope);
		in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard);

		if (V_ip6_log_time + V_ip6_log_interval < time_uptime) {
			V_ip6_log_time = time_uptime;
			log(LOG_DEBUG,
			    "cannot forward "
			    "src %s, dst %s, nxt %d, rcvif %s, outif %s\n",
			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
			    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
			    ip6->ip6_nxt,
			    if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp));
		}
		if (mcopy)
			icmp6_error(mcopy, ICMP6_DST_UNREACH,
				    ICMP6_DST_UNREACH_BEYONDSCOPE, 0);
		goto bad;
	}

	/*
	 * 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_INC(ip6s_cantforward);
		IP6STAT_INC(ip6s_badscope);
		goto bad;
	}

	if (rt->rt_flags & RTF_GATEWAY)
		dst = (struct sockaddr_in6 *)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 (V_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.
			 */
			icmp6_error(mcopy, ICMP6_DST_UNREACH,
				    ICMP6_DST_UNREACH_ADDR, 0);
			goto bad;
		}
		type = ND_REDIRECT;
	}

	/*
	 * 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(ip6bufs, &ip6->ip6_src),
			       ip6_sprintf(ip6bufd, &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 = m->m_pkthdr.rcvif;
	}
	else
		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);

	/* Jump over all PFIL processing if hooks are not active. */
	if (!PFIL_HOOKED(&V_inet6_pfil_hook))
		goto pass;

	odst = ip6->ip6_dst;
	/* Run through list of hooks for output packets. */
	error = pfil_run_hooks(&V_inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT, NULL);
	if (error != 0 || m == NULL)
		goto freecopy;		/* consumed by filter */
	ip6 = mtod(m, struct ip6_hdr *);

	/* See if destination IP address was changed by packet filter. */
	if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
		m->m_flags |= M_SKIP_FIREWALL;
		/* If destination is now ourself drop to ip6_input(). */
		if (in6_localip(&ip6->ip6_dst))
			m->m_flags |= M_FASTFWD_OURS;
		else {
			RTFREE(rt);
			goto again;	/* Redo the routing table lookup. */
		}
	}

	/* See if local, if yes, send it to netisr. */
	if (m->m_flags & M_FASTFWD_OURS) {
		if (m->m_pkthdr.rcvif == NULL)
			m->m_pkthdr.rcvif = V_loif;
		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
			m->m_pkthdr.csum_flags |=
			    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
			m->m_pkthdr.csum_data = 0xffff;
		}
#ifdef SCTP
		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
#endif
		error = netisr_queue(NETISR_IPV6, m);
		goto out;
	}
	/* Or forward to some other address? */
	if ((m->m_flags & M_IP6_NEXTHOP) &&
	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
		dst = (struct sockaddr_in6 *)&rin6.ro_dst;
		bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in6));
		m->m_flags |= M_SKIP_FIREWALL;
		m->m_flags &= ~M_IP6_NEXTHOP;
		m_tag_delete(m, fwd_tag);
		RTFREE(rt);
		goto again2;
	}

pass:
	/* See if the size was changed by the packet filter. */
	if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) {
		in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig);
		if (mcopy)
			icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0,
			    IN6_LINKMTU(rt->rt_ifp));
		goto bad;
	}

	error = nd6_output_ifp(rt->rt_ifp, origifp, m, dst, NULL);
	if (error) {
		in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard);
		IP6STAT_INC(ip6s_cantforward);
	} else {
		IP6STAT_INC(ip6s_forward);
		in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward);
		if (type)
			IP6STAT_INC(ip6s_redirectsent);
		else {
			if (mcopy)
				goto freecopy;
		}
	}

	if (mcopy == NULL)
		goto out;
	switch (error) {
	case 0:
		if (type == ND_REDIRECT) {
			icmp6_redirect_output(mcopy, rt);
			goto out;
		}
		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);
	goto out;

 freecopy:
	m_freem(mcopy);
	goto out;
bad:
	m_freem(m);
out:
	if (rt != NULL)
		RTFREE(rt);
}
Exemplo n.º 7
0
/*
 * Forward a packet.  If some error occurs return the sender
 * an icmp packet.  Note we can't always generate a meaningful
 * icmp message because icmp doesn't have a large enough repertoire
 * of codes and types.
 *
 * If not forwarding, just drop the packet.  This could be confusing
 * if ipforwarding was zero but some routing protocol was advancing
 * us as a gateway to somewhere.  However, we must let the routing
 * protocol deal with that.
 *
 */
void
ip6_forward(struct mbuf *m, int srcrt)
{
	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
	struct sockaddr_in6 *dst = NULL;
	struct rtentry *rt = NULL;
	struct route_in6 rin6;
	int error, type = 0, code = 0;
	struct mbuf *mcopy = NULL;
	struct ifnet *origifp;	/* maybe unnecessary */
	u_int32_t inzone, outzone;
	struct in6_addr src_in6, dst_in6, odst;
#ifdef IPSEC
	struct secpolicy *sp = NULL;
#endif
#ifdef SCTP
	int sw_csum;
#endif
	struct m_tag *fwd_tag;
	char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];

#ifdef IPSEC
	/*
	 * Check AH/ESP integrity.
	 */
	/*
	 * Don't increment ip6s_cantforward because this is the check
	 * before forwarding packet actually.
	 */
	if (ipsec6_in_reject(m, NULL)) {
		IPSEC6STAT_INC(ips_in_polvio);
		m_freem(m);
		return;
	}
#endif /* IPSEC */

	/*
	 * 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 the 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_INC(ip6s_cantforward);
		/* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */
		if (V_ip6_log_time + V_ip6_log_interval < time_uptime) {
			V_ip6_log_time = time_uptime;
			log(LOG_DEBUG,
			    "cannot forward "
			    "from %s to %s nxt %d received on %s\n",
			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
			    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
			    ip6->ip6_nxt,
			    if_name(m->m_pkthdr.rcvif));
		}
		m_freem(m);
		return;
	}

#ifdef IPSTEALTH
	if (!V_ip6stealth) {
#endif
	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;

#ifdef IPSTEALTH
	}
#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));

#ifdef IPSEC
	/* get a security policy for this packet */
	sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND,
	    IP_FORWARDING, &error);
	if (sp == NULL) {
		IPSEC6STAT_INC(ips_out_inval);
		IP6STAT_INC(ip6s_cantforward);
		if (mcopy) {
#if 0
			/* XXX: what icmp ? */
#else
			m_freem(mcopy);
#endif
		}
		m_freem(m);
		return;
	}

	error = 0;

	/* check policy */
	switch (sp->policy) {
	case IPSEC_POLICY_DISCARD:
		/*
		 * This packet is just discarded.
		 */
		IPSEC6STAT_INC(ips_out_polvio);
		IP6STAT_INC(ip6s_cantforward);
		KEY_FREESP(&sp);
		if (mcopy) {
#if 0
			/* XXX: what icmp ? */
#else
			m_freem(mcopy);
#endif
		}
		m_freem(m);
		return;

	case IPSEC_POLICY_BYPASS:
	case IPSEC_POLICY_NONE:
		/* no need to do IPsec. */
		KEY_FREESP(&sp);
		goto skip_ipsec;

	case IPSEC_POLICY_IPSEC:
		if (sp->req == NULL) {
			/* XXX should be panic ? */
			printf("ip6_forward: No IPsec request specified.\n");
			IP6STAT_INC(ip6s_cantforward);
			KEY_FREESP(&sp);
			if (mcopy) {
#if 0
				/* XXX: what icmp ? */
#else
				m_freem(mcopy);
#endif
			}
			m_freem(m);
			return;
		}
		/* do IPsec */
		break;

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

    {
	struct ipsecrequest *isr = NULL;

	/*
	 * when the kernel forwards a packet, it is not proper to apply
	 * IPsec transport mode to the packet is not proper.  this check
	 * avoid from this.
	 * at present, if there is even a transport mode SA request in the
	 * security policy, the kernel does not apply IPsec to the packet.
	 * this check is not enough because the following case is valid.
	 *      ipsec esp/tunnel/xxx-xxx/require esp/transport//require;
	 */
	for (isr = sp->req; isr; isr = isr->next) {
		if (isr->saidx.mode == IPSEC_MODE_ANY)
			goto doipsectunnel;
		if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
			goto doipsectunnel;
	}

	/*
	 * if there's no need for tunnel mode IPsec, skip.
	 */
	if (!isr)
		goto skip_ipsec;

    doipsectunnel:
	/*
	 * 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
	 */

	/*
	 * If we need to encapsulate the packet, do it here
	 * ipsec6_proces_packet will send the packet using ip6_output
	 */
	error = ipsec6_process_packet(m, sp->req);

	KEY_FREESP(&sp);

	if (error == EJUSTRETURN) {
		/*
		 * We had a SP with a level of 'use' and no SA. We
		 * will just continue to process the packet without
		 * IPsec processing.
		 */
		error = 0;
		goto skip_ipsec;
	}

	if (error) {
		/* mbuf is already reclaimed in ipsec6_process_packet. */
		switch (error) {
		case EHOSTUNREACH:
		case ENETUNREACH:
		case EMSGSIZE:
		case ENOBUFS:
		case ENOMEM:
			break;
		default:
			printf("ip6_output (ipsec): error code %d\n", error);
			/* FALLTHROUGH */
		case ENOENT:
			/* don't show these error codes to the user */
			break;
		}
		IP6STAT_INC(ip6s_cantforward);
		if (mcopy) {
#if 0
			/* XXX: what icmp ? */
#else
			m_freem(mcopy);
#endif
		}
		return;
	} else {
		/*
		 * In the FAST IPSec case we have already
		 * re-injected the packet and it has been freed
		 * by the ipsec_done() function.  So, just clean
		 * up after ourselves.
		 */
		m = NULL;
		goto freecopy;
	}
    }
skip_ipsec:
#endif
again:
	bzero(&rin6, sizeof(struct route_in6));
	dst = (struct sockaddr_in6 *)&rin6.ro_dst;
	dst->sin6_len = sizeof(struct sockaddr_in6);
	dst->sin6_family = AF_INET6;
	dst->sin6_addr = ip6->ip6_dst;
again2:
	rin6.ro_rt = in6_rtalloc1((struct sockaddr *)dst, 0, 0, M_GETFIB(m));
	if (rin6.ro_rt != NULL)
		RT_UNLOCK(rin6.ro_rt);
	else {
		IP6STAT_INC(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);
		}
		goto bad;
	}
	rt = rin6.ro_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).  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_INC(ip6s_cantforward);
		IP6STAT_INC(ip6s_badscope);
		goto bad;
	}
	if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) {
		IP6STAT_INC(ip6s_cantforward);
		IP6STAT_INC(ip6s_badscope);
		goto bad;
	}
	if (inzone != outzone) {
		IP6STAT_INC(ip6s_cantforward);
		IP6STAT_INC(ip6s_badscope);
		in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard);

		if (V_ip6_log_time + V_ip6_log_interval < time_uptime) {
			V_ip6_log_time = time_uptime;
			log(LOG_DEBUG,
			    "cannot forward "
			    "src %s, dst %s, nxt %d, rcvif %s, outif %s\n",
			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
			    ip6_sprintf(ip6bufd, &ip6->ip6_dst),
			    ip6->ip6_nxt,
			    if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp));
		}
		if (mcopy)
			icmp6_error(mcopy, ICMP6_DST_UNREACH,
				    ICMP6_DST_UNREACH_BEYONDSCOPE, 0);
		goto bad;
	}

	/*
	 * 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_INC(ip6s_cantforward);
		IP6STAT_INC(ip6s_badscope);
		goto bad;
	}

	if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) {
		in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig);
		if (mcopy) {
			u_long mtu;
#ifdef IPSEC
			struct secpolicy *sp;
			int ipsecerror;
			size_t ipsechdrsiz;
#endif /* IPSEC */

			mtu = IN6_LINKMTU(rt->rt_ifp);
#ifdef 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".
			 */
			sp = ipsec_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND,
				IP_FORWARDING, &ipsecerror);
			if (sp) {
				ipsechdrsiz = ipsec_hdrsiz(mcopy,
					IPSEC_DIR_OUTBOUND, NULL);
				if (ipsechdrsiz < mtu)
					mtu -= ipsechdrsiz;
			}

			/*
			 * 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 /* IPSEC */
			icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu);
		}
		goto bad;
	}

	if (rt->rt_flags & RTF_GATEWAY)
		dst = (struct sockaddr_in6 *)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 (V_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.
			 */
			icmp6_error(mcopy, ICMP6_DST_UNREACH,
				    ICMP6_DST_UNREACH_ADDR, 0);
			goto bad;
		}
		type = ND_REDIRECT;
	}

	/*
	 * 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(ip6bufs, &ip6->ip6_src),
			       ip6_sprintf(ip6bufd, &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 = m->m_pkthdr.rcvif;
	}
	else
		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);

	/* Jump over all PFIL processing if hooks are not active. */
	if (!PFIL_HOOKED(&V_inet6_pfil_hook))
		goto pass;

	odst = ip6->ip6_dst;
	/* Run through list of hooks for output packets. */
	error = pfil_run_hooks(&V_inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT, NULL);
	if (error != 0 || m == NULL)
		goto freecopy;		/* consumed by filter */
	ip6 = mtod(m, struct ip6_hdr *);

	/* See if destination IP address was changed by packet filter. */
	if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
		m->m_flags |= M_SKIP_FIREWALL;
		/* If destination is now ourself drop to ip6_input(). */
		if (in6_localip(&ip6->ip6_dst)) {
			m->m_flags |= M_FASTFWD_OURS;
			if (m->m_pkthdr.rcvif == NULL)
				m->m_pkthdr.rcvif = V_loif;
			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
				m->m_pkthdr.csum_flags |=
				    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
				m->m_pkthdr.csum_data = 0xffff;
			}
#ifdef SCTP
			if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
#endif
			error = netisr_queue(NETISR_IPV6, m);
			goto out;
		} else
			goto again;	/* Redo the routing table lookup. */
	}

	/* See if local, if yes, send it to netisr. */
	if (m->m_flags & M_FASTFWD_OURS) {
		if (m->m_pkthdr.rcvif == NULL)
			m->m_pkthdr.rcvif = V_loif;
		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
			m->m_pkthdr.csum_flags |=
			    CSUM_DATA_VALID_IPV6 | CSUM_PSEUDO_HDR;
			m->m_pkthdr.csum_data = 0xffff;
		}
#ifdef SCTP
		if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6)
			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
#endif
		error = netisr_queue(NETISR_IPV6, m);
		goto out;
	}
	/* Or forward to some other address? */
	if ((m->m_flags & M_IP6_NEXTHOP) &&
	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
		dst = (struct sockaddr_in6 *)&rin6.ro_dst;
		bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in6));
		m->m_flags |= M_SKIP_FIREWALL;
		m->m_flags &= ~M_IP6_NEXTHOP;
		m_tag_delete(m, fwd_tag);
		goto again2;
	}

pass:
	error = nd6_output(rt->rt_ifp, origifp, m, dst, rt);
	if (error) {
		in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard);
		IP6STAT_INC(ip6s_cantforward);
	} else {
		IP6STAT_INC(ip6s_forward);
		in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward);
		if (type)
			IP6STAT_INC(ip6s_redirectsent);
		else {
			if (mcopy)
				goto freecopy;
		}
	}

	if (mcopy == NULL)
		goto out;
	switch (error) {
	case 0:
		if (type == ND_REDIRECT) {
			icmp6_redirect_output(mcopy, rt);
			goto out;
		}
		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);
	goto out;

 freecopy:
	m_freem(mcopy);
	goto out;
bad:
	m_freem(m);
out:
	if (rt != NULL)
		RTFREE(rt);
}
Exemplo n.º 8
0
/*
 * 
 * Called from ip_output().
 * 1 = drop packet, 0 = continue processing packet,
 * -1 = packet was reinjected and stop processing packet
 */
int
ip_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error)
{
#ifdef IPSEC
	struct secpolicy *sp = NULL;
	struct ip *ip = mtod(*m, struct ip *);
	struct tdb_ident *tdbi;
	struct m_tag *mtag;
	int s;
	/*
	 * Check the security policy (SP) for the packet and, if
	 * required, do IPsec-related processing.  There are two
	 * cases here; the first time a packet is sent through
	 * it will be untagged and handled by ipsec4_checkpolicy.
	 * If the packet is resubmitted to ip_output (e.g. after
	 * AH, ESP, etc. processing), there will be a tag to bypass
	 * the lookup and related policy checking.
	 */
	mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
	s = splnet();
	if (mtag != NULL) {
		tdbi = (struct tdb_ident *)(mtag + 1);
		sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
		if (sp == NULL)
			*error = -EINVAL;	/* force silent drop */
		m_tag_delete(*m, mtag);
	} else {
		sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags,
					error, inp);
	}
	/*
	 * There are four return cases:
	 *    sp != NULL	 	    apply IPsec policy
	 *    sp == NULL, error == 0	    no IPsec handling needed
	 *    sp == NULL, error == -EINVAL  discard packet w/o error
	 *    sp == NULL, error != 0	    discard packet, report error
	 */
	if (sp != NULL) {
		/* Loop detection, check if ipsec processing already done */
		KASSERT(sp->req != NULL, ("ip_output: no ipsec request"));
		for (mtag = m_tag_first(*m); mtag != NULL;
		     mtag = m_tag_next(*m, mtag)) {
			if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
				continue;
			if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
			    mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
				continue;
			/*
			 * Check if policy has an SA associated with it.
			 * This can happen when an SP has yet to acquire
			 * an SA; e.g. on first reference.  If it occurs,
			 * then we let ipsec4_process_packet do its thing.
			 */
			if (sp->req->sav == NULL)
				break;
			tdbi = (struct tdb_ident *)(mtag + 1);
			if (tdbi->spi == sp->req->sav->spi &&
			    tdbi->proto == sp->req->sav->sah->saidx.proto &&
			    bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst,
				 sizeof (union sockaddr_union)) == 0) {
				/*
				 * No IPsec processing is needed, free
				 * reference to SP.
				 *
				 * NB: null pointer to avoid free at
				 *     done: below.
				 */
				KEY_FREESP(&sp), sp = NULL;
				splx(s);
				goto done;
			}
		}

		/*
		 * Do delayed checksums now because we send before
		 * this is done in the normal processing path.
		 */
		if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
			in_delayed_cksum(*m);
			(*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
		}
#ifdef SCTP
		if ((*m)->m_pkthdr.csum_flags & CSUM_SCTP) {
			sctp_delayed_cksum(*m, (uint32_t)(ip->ip_hl << 2));
			(*m)->m_pkthdr.csum_flags &= ~CSUM_SCTP;
		}
#endif
		ip->ip_len = htons(ip->ip_len);
		ip->ip_off = htons(ip->ip_off);

		/* NB: callee frees mbuf */
		*error = ipsec4_process_packet(*m, sp->req, *flags, 0);
		if (*error == EJUSTRETURN) {
			/*
			 * We had a SP with a level of 'use' and no SA. We
			 * will just continue to process the packet without
			 * IPsec processing and return without error.
			 */
			*error = 0;
			ip->ip_len = ntohs(ip->ip_len);
			ip->ip_off = ntohs(ip->ip_off);
			goto done;
		}
		/*
		 * Preserve KAME behaviour: ENOENT can be returned
		 * when an SA acquire is in progress.  Don't propagate
		 * this to user-level; it confuses applications.
		 *
		 * XXX this will go away when the SADB is redone.
		 */
		if (*error == ENOENT)
			*error = 0;
		splx(s);
		goto reinjected;
	} else {	/* sp == NULL */
		splx(s);

		if (*error != 0) {
			/*
			 * Hack: -EINVAL is used to signal that a packet
			 * should be silently discarded.  This is typically
			 * because we asked key management for an SA and
			 * it was delayed (e.g. kicked up to IKE).
			 */
			if (*error == -EINVAL)
				*error = 0;
			goto bad;
		} else {
			/* No IPsec processing for this packet. */
		}
	}
done:
	if (sp != NULL)
		KEY_FREESP(&sp);
	return 0;
reinjected:
	if (sp != NULL)
		KEY_FREESP(&sp);
	return -1;
bad:
	if (sp != NULL)
		KEY_FREESP(&sp);
	return 1;
#endif /* IPSEC */
	return 0;
}
Exemplo n.º 9
0
static inline int
ip_output_pfil(struct mbuf **mp, struct ifnet *ifp, struct inpcb *inp,
    struct sockaddr_in *dst, int *fibnum, int *error)
{
	struct m_tag *fwd_tag = NULL;
	struct mbuf *m;
	struct in_addr odst;
	struct ip *ip;

	m = *mp;
	ip = mtod(m, struct ip *);

	/* Run through list of hooks for output packets. */
	odst.s_addr = ip->ip_dst.s_addr;
	*error = pfil_run_hooks(&V_inet_pfil_hook, mp, ifp, PFIL_OUT, inp);
	m = *mp;
	if ((*error) != 0 || m == NULL)
		return 1; /* Finished */

	ip = mtod(m, struct ip *);

	/* See if destination IP address was changed by packet filter. */
	if (odst.s_addr != ip->ip_dst.s_addr) {
		m->m_flags |= M_SKIP_FIREWALL;
		/* If destination is now ourself drop to ip_input(). */
		if (in_localip(ip->ip_dst)) {
			m->m_flags |= M_FASTFWD_OURS;
			if (m->m_pkthdr.rcvif == NULL)
				m->m_pkthdr.rcvif = V_loif;
			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
				m->m_pkthdr.csum_flags |=
					CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
				m->m_pkthdr.csum_data = 0xffff;
			}
			m->m_pkthdr.csum_flags |=
				CSUM_IP_CHECKED | CSUM_IP_VALID;
#ifdef SCTP
			if (m->m_pkthdr.csum_flags & CSUM_SCTP)
				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
#endif
			*error = netisr_queue(NETISR_IP, m);
			return 1; /* Finished */
		}

		bzero(dst, sizeof(*dst));
		dst->sin_family = AF_INET;
		dst->sin_len = sizeof(*dst);
		dst->sin_addr = ip->ip_dst;

		return -1; /* Reloop */
	}
	/* See if fib was changed by packet filter. */
	if ((*fibnum) != M_GETFIB(m)) {
		m->m_flags |= M_SKIP_FIREWALL;
		*fibnum = M_GETFIB(m);
		return -1; /* Reloop for FIB change */
	}

	/* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
	if (m->m_flags & M_FASTFWD_OURS) {
		if (m->m_pkthdr.rcvif == NULL)
			m->m_pkthdr.rcvif = V_loif;
		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
			m->m_pkthdr.csum_flags |=
				CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
			m->m_pkthdr.csum_data = 0xffff;
		}
#ifdef SCTP
		if (m->m_pkthdr.csum_flags & CSUM_SCTP)
			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
#endif
		m->m_pkthdr.csum_flags |=
			CSUM_IP_CHECKED | CSUM_IP_VALID;

		*error = netisr_queue(NETISR_IP, m);
		return 1; /* Finished */
	}
	/* Or forward to some other address? */
	if ((m->m_flags & M_IP_NEXTHOP) &&
	    ((fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL)) {
		bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
		m->m_flags |= M_SKIP_FIREWALL;
		m->m_flags &= ~M_IP_NEXTHOP;
		m_tag_delete(m, fwd_tag);

		return -1; /* Reloop for CHANGE of dst */
	}

	return 0;
}
Exemplo n.º 10
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;
#if NPF > 0
	struct ifnet *encif;
#endif
#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->rdomain, 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 &&
			    tdbi->rdomain == tdb->tdb_rdomain &&
			    !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_rt.ro_tableid != 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 */
			ip6_forward_rt.ro_tableid = rtableid;
			rtalloc_mpath((struct route *)&ip6_forward_rt,
			    &ip6->ip6_src.s6_addr32[0]);
		}

		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_rt.ro_tableid != 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;
		ip6_forward_rt.ro_tableid = rtableid;

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

		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();

		tdb = gettdb(rtable_l2(m->m_pkthdr.rdomain),
		    sspi, &sdst, sproto);
		if (tdb == NULL) {
			splx(s);
			error = EHOSTUNREACH;
			m_freem(m);
			goto senderr;	/*XXX*/
		}

#if NPF > 0
		if ((encif = enc_getif(tdb->tdb_rdomain,
		    tdb->tdb_tap)) == NULL ||
		    pf_test6(PF_FWD, encif, &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

		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;
	}
Exemplo n.º 11
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 = proto;
	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);
}
Exemplo n.º 12
0
struct mbuf*
ip6_tryforward(struct mbuf *m)
{
	struct sockaddr_in6 dst;
	struct nhop6_basic nh;
	struct m_tag *fwd_tag;
	struct ip6_hdr *ip6;
	struct ifnet *rcvif;
	uint32_t plen;
	int error;

	/*
	 * Fallback conditions to ip6_input for slow path processing.
	 */
	ip6 = mtod(m, struct ip6_hdr *);
	if (ip6->ip6_nxt == IPPROTO_HOPOPTS ||
	    IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
	    IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst) ||
	    IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src) ||
	    IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) ||
	    in6_localip(&ip6->ip6_dst))
		return (m);
	/*
	 * 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.
	 */
	rcvif = m->m_pkthdr.rcvif;
	plen = ntohs(ip6->ip6_plen);
	if (plen == 0) {
		/*
		 * Jumbograms must have hop-by-hop header and go via
		 * slow path.
		 */
		IP6STAT_INC(ip6s_badoptions);
		goto dropin;
	}
	if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
		IP6STAT_INC(ip6s_tooshort);
		in6_ifstat_inc(rcvif, ifs6_in_truncated);
		goto dropin;
	}
	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);
	}

	/*
	 * Hop limit.
	 */
#ifdef IPSTEALTH
	if (!V_ip6stealth)
#endif
	if (ip6->ip6_hlim <= IPV6_HLIMDEC) {
		icmp6_error(m, ICMP6_TIME_EXCEEDED,
		    ICMP6_TIME_EXCEED_TRANSIT, 0);
		m = NULL;
		goto dropin;
	}

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

	/*
	 * Incoming packet firewall processing.
	 */
	if (!PFIL_HOOKED(&V_inet6_pfil_hook))
		goto passin;
	if (pfil_run_hooks(&V_inet6_pfil_hook, &m, rcvif, PFIL_IN,
	    NULL) != 0 || m == NULL)
		goto dropin;
	/*
	 * If packet filter sets the M_FASTFWD_OURS flag, this means
	 * that new destination or next hop is our local address.
	 * So, we can just go back to ip6_input.
	 * XXX: should we decrement ip6_hlim in such case?
	 *
	 * Also it can forward packet to another destination, e.g.
	 * M_IP6_NEXTHOP flag is set and fwd_tag is attached to mbuf.
	 */
	if (m->m_flags & M_FASTFWD_OURS)
		return (m);

	ip6 = mtod(m, struct ip6_hdr *);
	if ((m->m_flags & M_IP6_NEXTHOP) &&
	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
		/*
		 * Now we will find route to forwarded by pfil destination.
		 */
		bcopy((fwd_tag + 1), &dst, sizeof(dst));
		m->m_flags &= ~M_IP6_NEXTHOP;
		m_tag_delete(m, fwd_tag);
	} else {
		/* Update dst since pfil could change it */
		dst.sin6_addr = ip6->ip6_dst;
	}
passin:
	/*
	 * Find route to destination.
	 */
	if (ip6_findroute(&nh, &dst, m) != 0) {
		m = NULL;
		in6_ifstat_inc(rcvif, ifs6_in_noroute);
		goto dropin;
	}
	/*
	 * We used slow path processing for packets with scoped addresses.
	 * So, scope checks aren't needed here.
	 */
	if (m->m_pkthdr.len > nh.nh_mtu) {
		in6_ifstat_inc(nh.nh_ifp, ifs6_in_toobig);
		icmp6_error(m, ICMP6_PACKET_TOO_BIG, 0, nh.nh_mtu);
		m = NULL;
		goto dropout;
	}

	/*
	 * Outgoing packet firewall processing.
	 */
	if (!PFIL_HOOKED(&V_inet6_pfil_hook))
		goto passout;
	if (pfil_run_hooks(&V_inet6_pfil_hook, &m, nh.nh_ifp, PFIL_OUT,
	    NULL) != 0 || m == NULL)
		goto dropout;
	/*
	 * If packet filter sets the M_FASTFWD_OURS flag, this means
	 * that new destination or next hop is our local address.
	 * So, we can just go back to ip6_input.
	 *
	 * Also it can forward packet to another destination, e.g.
	 * M_IP6_NEXTHOP flag is set and fwd_tag is attached to mbuf.
	 */
	if (m->m_flags & M_FASTFWD_OURS) {
		/*
		 * XXX: we did one hop and should decrement hop limit. But
		 * now we are the destination and just don't pay attention.
		 */
		return (m);
	}
	/*
	 * Again. A packet filter could change the destination address.
	 */
	ip6 = mtod(m, struct ip6_hdr *);
	if (m->m_flags & M_IP6_NEXTHOP)
		fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
	else
		fwd_tag = NULL;

	if (fwd_tag != NULL ||
	    !IN6_ARE_ADDR_EQUAL(&dst.sin6_addr, &ip6->ip6_dst)) {
		if (fwd_tag != NULL) {
			bcopy((fwd_tag + 1), &dst, sizeof(dst));
			m->m_flags &= ~M_IP6_NEXTHOP;
			m_tag_delete(m, fwd_tag);
		} else
			dst.sin6_addr = ip6->ip6_dst;
		/*
		 * Redo route lookup with new destination address
		 */
		if (ip6_findroute(&nh, &dst, m) != 0) {
			m = NULL;
			goto dropout;
		}
	}
passout:
#ifdef IPSTEALTH
	if (!V_ip6stealth)
#endif
	{
		ip6->ip6_hlim -= IPV6_HLIMDEC;
	}

	m_clrprotoflags(m);	/* Avoid confusing lower layers. */
	IP_PROBE(send, NULL, NULL, ip6, nh.nh_ifp, NULL, ip6);

	/*
	 * XXX: we need to use destination address with embedded scope
	 * zone id, because LLTABLE uses such form of addresses for lookup.
	 */
	dst.sin6_addr = nh.nh_addr;
	if (IN6_IS_SCOPE_LINKLOCAL(&dst.sin6_addr))
		dst.sin6_addr.s6_addr16[1] = htons(nh.nh_ifp->if_index & 0xffff);

	error = (*nh.nh_ifp->if_output)(nh.nh_ifp, m,
	    (struct sockaddr *)&dst, NULL);
	if (error != 0) {
		in6_ifstat_inc(nh.nh_ifp, ifs6_out_discard);
		IP6STAT_INC(ip6s_cantforward);
	} else {
		in6_ifstat_inc(nh.nh_ifp, ifs6_out_forward);
		IP6STAT_INC(ip6s_forward);
	}
	return (NULL);
dropin:
	in6_ifstat_inc(rcvif, ifs6_in_discard);
	goto drop;
dropout:
	in6_ifstat_inc(nh.nh_ifp, ifs6_out_discard);
drop:
	if (m != NULL)
		m_freem(m);
	return (NULL);
}
Exemplo n.º 13
0
int
ip6_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error,
    struct ifnet **ifp, struct secpolicy **sp)
{
#ifdef IPSEC
	struct tdb_ident *tdbi;
	struct m_tag *mtag;
	/* XXX int s; */
	if (sp == NULL)
		return 1;
	mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
	if (mtag != NULL) {
		tdbi = (struct tdb_ident *)(mtag + 1);
		*sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
		if (*sp == NULL)
			*error = -EINVAL;	/* force silent drop */
		m_tag_delete(*m, mtag);
	} else {
		*sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags,
					error, inp);
	}

	/*
	 * There are four return cases:
	 *    sp != NULL		    apply IPsec policy
	 *    sp == NULL, error == 0	    no IPsec handling needed
	 *    sp == NULL, error == -EINVAL  discard packet w/o error
	 *    sp == NULL, error != 0	    discard packet, report error
	 */
	if (*sp != NULL) {
		/* Loop detection, check if ipsec processing already done */
		KASSERT((*sp)->req != NULL, ("ip_output: no ipsec request"));
		for (mtag = m_tag_first(*m); mtag != NULL;
		     mtag = m_tag_next(*m, mtag)) {
			if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
				continue;
			if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
			    mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
				continue;
			/*
			 * Check if policy has an SA associated with it.
			 * This can happen when an SP has yet to acquire
			 * an SA; e.g. on first reference.  If it occurs,
			 * then we let ipsec4_process_packet do its thing.
			 */
			if ((*sp)->req->sav == NULL)
				break;
			tdbi = (struct tdb_ident *)(mtag + 1);
			if (tdbi->spi == (*sp)->req->sav->spi &&
			    tdbi->proto == (*sp)->req->sav->sah->saidx.proto &&
			    bcmp(&tdbi->dst, &(*sp)->req->sav->sah->saidx.dst,
				 sizeof (union sockaddr_union)) == 0) {
				/*
				 * No IPsec processing is needed, free
				 * reference to SP.
				 *
				 * NB: null pointer to avoid free at
				 *     done: below.
				 */
				KEY_FREESP(sp), *sp = NULL;
				/* XXX splx(s); */
				goto done;
			}
		}

		/*
		 * Do delayed checksums now because we send before
		 * this is done in the normal processing path.
		 */
		if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
			ipseclog((LOG_DEBUG,
			    "%s: we do not support IPv4 over IPv6", __func__));
#ifdef INET
			in_delayed_cksum(*m);
#endif
			(*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
		}

		/*
		 * Preserve KAME behaviour: ENOENT can be returned
		 * when an SA acquire is in progress.  Don't propagate
		 * this to user-level; it confuses applications.
		 *
		 * XXX this will go away when the SADB is redone.
		 */
		if (*error == ENOENT)
			*error = 0;
		goto do_ipsec;
	} else {	/* sp == NULL */
		if (*error != 0) {
			/*
			 * Hack: -EINVAL is used to signal that a packet
			 * should be silently discarded.  This is typically
			 * because we asked key management for an SA and
			 * it was delayed (e.g. kicked up to IKE).
			 */
			if (*error == -EINVAL)
				*error = 0;
			goto bad;
		} else {
			/* No IPsec processing for this packet. */
		}
	}
done:
	return 0;
do_ipsec:
	return -1;
bad:
	return 1;
#endif /* IPSEC */
	return 0;
}
Exemplo n.º 14
0
int
ipfw_check_in(void *arg, struct mbuf **m0, struct ifnet *ifp, int dir,
    struct inpcb *inp)
{
	struct ip_fw_args args;
	struct m_tag *dn_tag;
	int ipfw = 0;
	int divert;
#ifdef IPFIREWALL_FORWARD
	struct m_tag *fwd_tag;
#endif

	KASSERT(dir == PFIL_IN, ("ipfw_check_in wrong direction!"));

	if (!fw_enable)
		goto pass;

	bzero(&args, sizeof(args));

	dn_tag = m_tag_find(*m0, PACKET_TAG_DUMMYNET, NULL);
	if (dn_tag != NULL){
		struct dn_pkt_tag *dt;

		dt = (struct dn_pkt_tag *)(dn_tag+1);
		args.rule = dt->rule;

		m_tag_delete(*m0, dn_tag);
	}

again:
	args.m = *m0;
	args.inp = inp;
	ipfw = ipfw_chk(&args);
	*m0 = args.m;

	if ((ipfw & IP_FW_PORT_DENY_FLAG) || *m0 == NULL)
		goto drop;

	if (ipfw == 0 && args.next_hop == NULL)
		goto pass;

	if (DUMMYNET_LOADED && (ipfw & IP_FW_PORT_DYNT_FLAG) != 0) {
		ip_dn_io_ptr(*m0, ipfw & 0xffff, DN_TO_IP_IN, &args);
		*m0 = NULL;
		return 0;		/* packet consumed */
	}

	if (ipfw != 0 && (ipfw & IP_FW_PORT_DYNT_FLAG) == 0) {
		if ((ipfw & IP_FW_PORT_TEE_FLAG) != 0)
			divert = ipfw_divert(m0, DIV_DIR_IN, 1);
		else
			divert = ipfw_divert(m0, DIV_DIR_IN, 0);

		/* tee should continue again with the firewall. */
		if (divert) {
			*m0 = NULL;
			return 0;	/* packet consumed */
		} else
			goto again;	/* continue with packet */
	}

#ifdef IPFIREWALL_FORWARD
	if (ipfw == 0 && args.next_hop != NULL) {
		fwd_tag = m_tag_get(PACKET_TAG_IPFORWARD,
				sizeof(struct sockaddr_in), M_NOWAIT);
		if (fwd_tag == NULL)
			goto drop;
		bcopy(args.next_hop, (fwd_tag+1), sizeof(struct sockaddr_in));
		m_tag_prepend(*m0, fwd_tag);

		if (in_localip(args.next_hop->sin_addr))
			(*m0)->m_flags |= M_FASTFWD_OURS;
		goto pass;
	}
#endif

drop:
	if (*m0)
		m_freem(*m0);
	*m0 = NULL;
	return (EACCES);
pass:
	return 0;	/* not filtered */
}