Exemplo n.º 1
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 2
0
static void
udp6_common_ctlinput(int cmd, struct sockaddr *sa, void *d,
    struct inpcbinfo *pcbinfo)
{
	struct udphdr uh;
	struct ip6_hdr *ip6;
	struct mbuf *m;
	int off = 0;
	struct ip6ctlparam *ip6cp = NULL;
	const struct sockaddr_in6 *sa6_src = NULL;
	void *cmdarg;
	struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
	struct udp_portonly {
		u_int16_t uh_sport;
		u_int16_t uh_dport;
	} *uhp;

	if (sa->sa_family != AF_INET6 ||
	    sa->sa_len != sizeof(struct sockaddr_in6))
		return;

	if ((unsigned)cmd >= PRC_NCMDS)
		return;
	if (PRC_IS_REDIRECT(cmd))
		notify = in6_rtchange, d = NULL;
	else if (cmd == PRC_HOSTDEAD)
		d = NULL;
	else if (inet6ctlerrmap[cmd] == 0)
		return;

	/* if the parameter is from icmp6, decode it. */
	if (d != NULL) {
		ip6cp = (struct ip6ctlparam *)d;
		m = ip6cp->ip6c_m;
		ip6 = ip6cp->ip6c_ip6;
		off = ip6cp->ip6c_off;
		cmdarg = ip6cp->ip6c_cmdarg;
		sa6_src = ip6cp->ip6c_src;
	} else {
		m = NULL;
		ip6 = NULL;
		cmdarg = NULL;
		sa6_src = &sa6_any;
	}

	if (ip6) {
		/*
		 * XXX: We assume that when IPV6 is non NULL,
		 * M and OFF are valid.
		 */

		/* Check if we can safely examine src and dst ports. */
		if (m->m_pkthdr.len < off + sizeof(*uhp))
			return;

		bzero(&uh, sizeof(uh));
		m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);

		if (!PRC_IS_REDIRECT(cmd)) {
			/* Check to see if its tunneled */
			struct inpcb *inp;
			inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_dst,
			    uh.uh_dport, &ip6->ip6_src, uh.uh_sport,
			    INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
			    m->m_pkthdr.rcvif, m);
			if (inp != NULL) {
				struct udpcb *up;
				
				up = intoudpcb(inp);
				if (up->u_icmp_func) {
					/* Yes it is. */
					INP_RUNLOCK(inp);
					(*up->u_icmp_func)(cmd, (struct sockaddr *)ip6cp->ip6c_src,
					      d, up->u_tun_ctx);
					return;
				} else {
					/* Can't find it. */
					INP_RUNLOCK(inp);
				}
			}
		}
		(void)in6_pcbnotify(pcbinfo, sa, uh.uh_dport,
		    (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
		    cmdarg, notify);
	} else
		(void)in6_pcbnotify(pcbinfo, sa, 0,
		    (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
}