Example #1
0
static int
udp6_append(struct inpcb *inp, struct mbuf *n, int off,
    struct sockaddr_in6 *fromsa)
{
	struct socket *so;
	struct mbuf *opts;
	struct udpcb *up;

	INP_LOCK_ASSERT(inp);

	/*
	 * Engage the tunneling protocol.
	 */
	up = intoudpcb(inp);
	if (up->u_tun_func != NULL) {
		in_pcbref(inp);
		INP_RUNLOCK(inp);
		(*up->u_tun_func)(n, off, inp, (struct sockaddr *)fromsa,
		    up->u_tun_ctx);
		INP_RLOCK(inp);
		return (in_pcbrele_rlocked(inp));
	}
#ifdef IPSEC
	/* Check AH/ESP integrity. */
	if (ipsec6_in_reject(n, inp)) {
		m_freem(n);
		return (0);
	}
#endif /* IPSEC */
#ifdef MAC
	if (mac_inpcb_check_deliver(inp, n) != 0) {
		m_freem(n);
		return (0);
	}
#endif
	opts = NULL;
	if (inp->inp_flags & INP_CONTROLOPTS ||
	    inp->inp_socket->so_options & SO_TIMESTAMP)
		ip6_savecontrol(inp, n, &opts);
	m_adj(n, off + sizeof(struct udphdr));

	so = inp->inp_socket;
	SOCKBUF_LOCK(&so->so_rcv);
	if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)fromsa, n,
	    opts) == 0) {
		SOCKBUF_UNLOCK(&so->so_rcv);
		m_freem(n);
		if (opts)
			m_freem(opts);
		UDPSTAT_INC(udps_fullsock);
	} else
		sorwakeup_locked(so);
	return (0);
}
Example #2
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);
}
Example #3
0
/*
 * Subroutine of udp_input(), which appends the provided mbuf chain to the
 * passed pcb/socket.  The caller must provide a sockaddr_in via udp_in that
 * contains the source address.  If the socket ends up being an IPv6 socket,
 * udp_append() will convert to a sockaddr_in6 before passing the address
 * into the socket code.
 */
static void
udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
    struct sockaddr_in *udp_in)
{
	struct sockaddr *append_sa;
	struct socket *so;
	struct mbuf *opts = 0;
#ifdef INET6
	struct sockaddr_in6 udp_in6;
#endif
	struct udpcb *up;

	INP_LOCK_ASSERT(inp);

	/*
	 * Engage the tunneling protocol.
	 */
	up = intoudpcb(inp);
	if (up->u_tun_func != NULL) {
		(*up->u_tun_func)(n, off, inp);
		return;
	}

	if (n == NULL)
		return;

	off += sizeof(struct udphdr);

#ifdef IPSEC
	/* Check AH/ESP integrity. */
	if (ipsec4_in_reject(n, inp)) {
		m_freem(n);
		IPSECSTAT_INC(ips_in_polvio);
		return;
	}
#ifdef IPSEC_NAT_T
	up = intoudpcb(inp);
	KASSERT(up != NULL, ("%s: udpcb NULL", __func__));
	if (up->u_flags & UF_ESPINUDP_ALL) {	/* IPSec UDP encaps. */
		n = udp4_espdecap(inp, n, off);
		if (n == NULL)				/* Consumed. */
			return;
	}
#endif /* IPSEC_NAT_T */
#endif /* IPSEC */
#ifdef MAC
	if (mac_inpcb_check_deliver(inp, n) != 0) {
		m_freem(n);
		return;
	}
#endif /* MAC */
	if (inp->inp_flags & INP_CONTROLOPTS ||
	    inp->inp_socket->so_options & (SO_TIMESTAMP | SO_BINTIME)) {
#ifdef INET6
		if (inp->inp_vflag & INP_IPV6)
			(void)ip6_savecontrol_v4(inp, n, &opts, NULL);
		else
#endif /* INET6 */
			ip_savecontrol(inp, &opts, ip, n);
	}
#ifdef INET6
	if (inp->inp_vflag & INP_IPV6) {
		bzero(&udp_in6, sizeof(udp_in6));
		udp_in6.sin6_len = sizeof(udp_in6);
		udp_in6.sin6_family = AF_INET6;
		in6_sin_2_v4mapsin6(udp_in, &udp_in6);
		append_sa = (struct sockaddr *)&udp_in6;
	} else
#endif /* INET6 */
		append_sa = (struct sockaddr *)udp_in;
	m_adj(n, off);

	so = inp->inp_socket;
	SOCKBUF_LOCK(&so->so_rcv);
	if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
		SOCKBUF_UNLOCK(&so->so_rcv);
		m_freem(n);
		if (opts)
			m_freem(opts);
		UDPSTAT_INC(udps_fullsock);
	} else
		sorwakeup_locked(so);
}
Example #4
0
static int
udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
    struct mbuf *control, struct thread *td)
{
	struct udpiphdr *ui;
	int len = m->m_pkthdr.len;
	struct in_addr faddr, laddr;
	struct cmsghdr *cm;
	struct inpcbinfo *pcbinfo;
	struct sockaddr_in *sin, src;
	int cscov_partial = 0;
	int error = 0;
	int ipflags;
	u_short fport, lport;
	int unlock_udbinfo;
	u_char tos;
	uint8_t pr;
	uint16_t cscov = 0;

	/*
	 * udp_output() may need to temporarily bind or connect the current
	 * inpcb.  As such, we don't know up front whether we will need the
	 * pcbinfo lock or not.  Do any work to decide what is needed up
	 * front before acquiring any locks.
	 */
	if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
		if (control)
			m_freem(control);
		m_freem(m);
		return (EMSGSIZE);
	}

	src.sin_family = 0;
	INP_RLOCK(inp);
	tos = inp->inp_ip_tos;
	if (control != NULL) {
		/*
		 * XXX: Currently, we assume all the optional information is
		 * stored in a single mbuf.
		 */
		if (control->m_next) {
			INP_RUNLOCK(inp);
			m_freem(control);
			m_freem(m);
			return (EINVAL);
		}
		for (; control->m_len > 0;
		    control->m_data += CMSG_ALIGN(cm->cmsg_len),
		    control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
			cm = mtod(control, struct cmsghdr *);
			if (control->m_len < sizeof(*cm) || cm->cmsg_len == 0
			    || cm->cmsg_len > control->m_len) {
				error = EINVAL;
				break;
			}
			if (cm->cmsg_level != IPPROTO_IP)
				continue;

			switch (cm->cmsg_type) {
			case IP_SENDSRCADDR:
				if (cm->cmsg_len !=
				    CMSG_LEN(sizeof(struct in_addr))) {
					error = EINVAL;
					break;
				}
				bzero(&src, sizeof(src));
				src.sin_family = AF_INET;
				src.sin_len = sizeof(src);
				src.sin_port = inp->inp_lport;
				src.sin_addr =
				    *(struct in_addr *)CMSG_DATA(cm);
				break;

			case IP_TOS:
				if (cm->cmsg_len != CMSG_LEN(sizeof(u_char))) {
					error = EINVAL;
					break;
				}
				tos = *(u_char *)CMSG_DATA(cm);
				break;

			default:
				error = ENOPROTOOPT;
				break;
			}
			if (error)
				break;
		}
		m_freem(control);
	}
	if (error) {
		INP_RUNLOCK(inp);
		m_freem(m);
		return (error);
	}

	/*
	 * Depending on whether or not the application has bound or connected
	 * the socket, we may have to do varying levels of work.  The optimal
	 * case is for a connected UDP socket, as a global lock isn't
	 * required at all.
	 *
	 * In order to decide which we need, we require stability of the
	 * inpcb binding, which we ensure by acquiring a read lock on the
	 * inpcb.  This doesn't strictly follow the lock order, so we play
	 * the trylock and retry game; note that we may end up with more
	 * conservative locks than required the second time around, so later
	 * assertions have to accept that.  Further analysis of the number of
	 * misses under contention is required.
	 *
	 * XXXRW: Check that hash locking update here is correct.
	 */
	pr = inp->inp_socket->so_proto->pr_protocol;
	pcbinfo = get_inpcbinfo(pr);
	sin = (struct sockaddr_in *)addr;
	if (sin != NULL &&
	    (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0)) {
		INP_RUNLOCK(inp);
		INP_WLOCK(inp);
		INP_HASH_WLOCK(pcbinfo);
		unlock_udbinfo = UH_WLOCKED;
	} else if ((sin != NULL && (
	    (sin->sin_addr.s_addr == INADDR_ANY) ||
	    (sin->sin_addr.s_addr == INADDR_BROADCAST) ||
	    (inp->inp_laddr.s_addr == INADDR_ANY) ||
	    (inp->inp_lport == 0))) ||
	    (src.sin_family == AF_INET)) {
		INP_HASH_RLOCK(pcbinfo);
		unlock_udbinfo = UH_RLOCKED;
	} else
		unlock_udbinfo = UH_UNLOCKED;

	/*
	 * If the IP_SENDSRCADDR control message was specified, override the
	 * source address for this datagram.  Its use is invalidated if the
	 * address thus specified is incomplete or clobbers other inpcbs.
	 */
	laddr = inp->inp_laddr;
	lport = inp->inp_lport;
	if (src.sin_family == AF_INET) {
		INP_HASH_LOCK_ASSERT(pcbinfo);
		if ((lport == 0) ||
		    (laddr.s_addr == INADDR_ANY &&
		     src.sin_addr.s_addr == INADDR_ANY)) {
			error = EINVAL;
			goto release;
		}
		error = in_pcbbind_setup(inp, (struct sockaddr *)&src,
		    &laddr.s_addr, &lport, td->td_ucred);
		if (error)
			goto release;
	}

	/*
	 * If a UDP socket has been connected, then a local address/port will
	 * have been selected and bound.
	 *
	 * If a UDP socket has not been connected to, then an explicit
	 * destination address must be used, in which case a local
	 * address/port may not have been selected and bound.
	 */
	if (sin != NULL) {
		INP_LOCK_ASSERT(inp);
		if (inp->inp_faddr.s_addr != INADDR_ANY) {
			error = EISCONN;
			goto release;
		}

		/*
		 * Jail may rewrite the destination address, so let it do
		 * that before we use it.
		 */
		error = prison_remote_ip4(td->td_ucred, &sin->sin_addr);
		if (error)
			goto release;

		/*
		 * If a local address or port hasn't yet been selected, or if
		 * the destination address needs to be rewritten due to using
		 * a special INADDR_ constant, invoke in_pcbconnect_setup()
		 * to do the heavy lifting.  Once a port is selected, we
		 * commit the binding back to the socket; we also commit the
		 * binding of the address if in jail.
		 *
		 * If we already have a valid binding and we're not
		 * requesting a destination address rewrite, use a fast path.
		 */
		if (inp->inp_laddr.s_addr == INADDR_ANY ||
		    inp->inp_lport == 0 ||
		    sin->sin_addr.s_addr == INADDR_ANY ||
		    sin->sin_addr.s_addr == INADDR_BROADCAST) {
			INP_HASH_LOCK_ASSERT(pcbinfo);
			error = in_pcbconnect_setup(inp, addr, &laddr.s_addr,
			    &lport, &faddr.s_addr, &fport, NULL,
			    td->td_ucred);
			if (error)
				goto release;

			/*
			 * XXXRW: Why not commit the port if the address is
			 * !INADDR_ANY?
			 */
			/* Commit the local port if newly assigned. */
			if (inp->inp_laddr.s_addr == INADDR_ANY &&
			    inp->inp_lport == 0) {
				INP_WLOCK_ASSERT(inp);
				INP_HASH_WLOCK_ASSERT(pcbinfo);
				/*
				 * Remember addr if jailed, to prevent
				 * rebinding.
				 */
				if (prison_flag(td->td_ucred, PR_IP4))
					inp->inp_laddr = laddr;
				inp->inp_lport = lport;
				if (in_pcbinshash(inp) != 0) {
					inp->inp_lport = 0;
					error = EAGAIN;
					goto release;
				}
				inp->inp_flags |= INP_ANONPORT;
			}
		} else {
			faddr = sin->sin_addr;
			fport = sin->sin_port;
		}
	} else {
		INP_LOCK_ASSERT(inp);
		faddr = inp->inp_faddr;
		fport = inp->inp_fport;
		if (faddr.s_addr == INADDR_ANY) {
			error = ENOTCONN;
			goto release;
		}
	}

	/*
	 * Calculate data length and get a mbuf for UDP, IP, and possible
	 * link-layer headers.  Immediate slide the data pointer back forward
	 * since we won't use that space at this layer.
	 */
	M_PREPEND(m, sizeof(struct udpiphdr) + max_linkhdr, M_NOWAIT);
	if (m == NULL) {
		error = ENOBUFS;
		goto release;
	}
	m->m_data += max_linkhdr;
	m->m_len -= max_linkhdr;
	m->m_pkthdr.len -= max_linkhdr;

	/*
	 * Fill in mbuf with extended UDP header and addresses and length put
	 * into network format.
	 */
	ui = mtod(m, struct udpiphdr *);
	bzero(ui->ui_x1, sizeof(ui->ui_x1));	/* XXX still needed? */
	ui->ui_pr = pr;
	ui->ui_src = laddr;
	ui->ui_dst = faddr;
	ui->ui_sport = lport;
	ui->ui_dport = fport;
	ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
	if (pr == IPPROTO_UDPLITE) {
		struct udpcb *up;
		uint16_t plen;

		up = intoudpcb(inp);
		cscov = up->u_txcslen;
		plen = (u_short)len + sizeof(struct udphdr);
		if (cscov >= plen)
			cscov = 0;
		ui->ui_len = htons(plen);
		ui->ui_ulen = htons(cscov);
		/*
		 * For UDP-Lite, checksum coverage length of zero means
		 * the entire UDPLite packet is covered by the checksum.
		 */
		 cscov_partial = (cscov == 0) ? 0 : 1;
	} else
		ui->ui_v = IPVERSION << 4;

	/*
	 * Set the Don't Fragment bit in the IP header.
	 */
	if (inp->inp_flags & INP_DONTFRAG) {
		struct ip *ip;

		ip = (struct ip *)&ui->ui_i;
		ip->ip_off |= htons(IP_DF);
	}

	ipflags = 0;
	if (inp->inp_socket->so_options & SO_DONTROUTE)
		ipflags |= IP_ROUTETOIF;
	if (inp->inp_socket->so_options & SO_BROADCAST)
		ipflags |= IP_ALLOWBROADCAST;
	if (inp->inp_flags & INP_ONESBCAST)
		ipflags |= IP_SENDONES;

#ifdef MAC
	mac_inpcb_create_mbuf(inp, m);
#endif

	/*
	 * Set up checksum and output datagram.
	 */
	ui->ui_sum = 0;
	if (cscov_partial) {
		if (inp->inp_flags & INP_ONESBCAST)
			faddr.s_addr = INADDR_BROADCAST;
		if ((ui->ui_sum = in_cksum(m, sizeof(struct ip) + cscov)) == 0)
			ui->ui_sum = 0xffff;
	} else if (V_udp_cksum || !cscov_partial) {
		if (inp->inp_flags & INP_ONESBCAST)
			faddr.s_addr = INADDR_BROADCAST;
		ui->ui_sum = in_pseudo(ui->ui_src.s_addr, faddr.s_addr,
		    htons((u_short)len + sizeof(struct udphdr) + pr));
		m->m_pkthdr.csum_flags = CSUM_UDP;
		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
	}
	((struct ip *)ui)->ip_len = htons(sizeof(struct udpiphdr) + len);
	((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl;	/* XXX */
	((struct ip *)ui)->ip_tos = tos;		/* XXX */
	UDPSTAT_INC(udps_opackets);

	if (unlock_udbinfo == UH_WLOCKED)
		INP_HASH_WUNLOCK(pcbinfo);
	else if (unlock_udbinfo == UH_RLOCKED)
		INP_HASH_RUNLOCK(pcbinfo);
	UDP_PROBE(send, NULL, inp, &ui->ui_i, inp, &ui->ui_u);
	error = ip_output(m, inp->inp_options, NULL, ipflags,
	    inp->inp_moptions, inp);
	if (unlock_udbinfo == UH_WLOCKED)
		INP_WUNLOCK(inp);
	else
		INP_RUNLOCK(inp);
	return (error);

release:
	if (unlock_udbinfo == UH_WLOCKED) {
		INP_HASH_WUNLOCK(pcbinfo);
		INP_WUNLOCK(inp);
	} else if (unlock_udbinfo == UH_RLOCKED) {
		INP_HASH_RUNLOCK(pcbinfo);
		INP_RUNLOCK(inp);
	} else
		INP_RUNLOCK(inp);
	m_freem(m);
	return (error);
}
Example #5
0
static int
udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
    struct mbuf *control, struct thread *td)
{
	u_int32_t ulen = m->m_pkthdr.len;
	u_int32_t plen = sizeof(struct udphdr) + ulen;
	struct ip6_hdr *ip6;
	struct udphdr *udp6;
	struct in6_addr *laddr, *faddr, in6a;
	struct sockaddr_in6 *sin6 = NULL;
	int cscov_partial = 0;
	int scope_ambiguous = 0;
	u_short fport;
	int error = 0;
	uint8_t nxt;
	uint16_t cscov = 0;
	struct ip6_pktopts *optp, opt;
	int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
	int flags;
	struct sockaddr_in6 tmp;

	INP_WLOCK_ASSERT(inp);
	INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);

	if (addr6) {
		/* addr6 has been validated in udp6_send(). */
		sin6 = (struct sockaddr_in6 *)addr6;

		/* protect *sin6 from overwrites */
		tmp = *sin6;
		sin6 = &tmp;

		/*
		 * Application should provide a proper zone ID or the use of
		 * default zone IDs should be enabled.  Unfortunately, some
		 * applications do not behave as it should, so we need a
		 * workaround.  Even if an appropriate ID is not determined,
		 * we'll see if we can determine the outgoing interface.  If we
		 * can, determine the zone ID based on the interface below.
		 */
		if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
			scope_ambiguous = 1;
		if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
			return (error);
	}

	nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
	    IPPROTO_UDP : IPPROTO_UDPLITE;
	if (control) {
		if ((error = ip6_setpktopts(control, &opt,
		    inp->in6p_outputopts, td->td_ucred, nxt)) != 0)
			goto release;
		optp = &opt;
	} else
		optp = inp->in6p_outputopts;

	if (sin6) {
		faddr = &sin6->sin6_addr;

		/*
		 * Since we saw no essential reason for calling in_pcbconnect,
		 * we get rid of such kind of logic, and call in6_selectsrc
		 * and in6_pcbsetport in order to fill in the local address
		 * and the local port.
		 */
		if (sin6->sin6_port == 0) {
			error = EADDRNOTAVAIL;
			goto release;
		}

		if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
			/* how about ::ffff:0.0.0.0 case? */
			error = EISCONN;
			goto release;
		}

		fport = sin6->sin6_port; /* allow 0 port */

		if (IN6_IS_ADDR_V4MAPPED(faddr)) {
			if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
				/*
				 * I believe we should explicitly discard the
				 * packet when mapped addresses are disabled,
				 * rather than send the packet as an IPv6 one.
				 * If we chose the latter approach, the packet
				 * might be sent out on the wire based on the
				 * default route, the situation which we'd
				 * probably want to avoid.
				 * (20010421 [email protected])
				 */
				error = EINVAL;
				goto release;
			}
			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
			    !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
				/*
				 * when remote addr is an IPv4-mapped address,
				 * local addr should not be an IPv6 address,
				 * since you cannot determine how to map IPv6
				 * source address to IPv4.
				 */
				error = EINVAL;
				goto release;
			}

			af = AF_INET;
		}

		if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
			error = in6_selectsrc_socket(sin6, optp, inp,
			    td->td_ucred, scope_ambiguous, &in6a, NULL);
			if (error)
				goto release;
			laddr = &in6a;
		} else
			laddr = &inp->in6p_laddr;	/* XXX */
		if (laddr == NULL) {
			if (error == 0)
				error = EADDRNOTAVAIL;
			goto release;
		}
		if (inp->inp_lport == 0 &&
		    (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0) {
			/* Undo an address bind that may have occurred. */
			inp->in6p_laddr = in6addr_any;
			goto release;
		}
	} else {
		if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
			error = ENOTCONN;
			goto release;
		}
		if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
			if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
				/*
				 * XXX: this case would happen when the
				 * application sets the V6ONLY flag after
				 * connecting the foreign address.
				 * Such applications should be fixed,
				 * so we bark here.
				 */
				log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
				    "option was set for a connected socket\n");
				error = EINVAL;
				goto release;
			} else
				af = AF_INET;
		}
		laddr = &inp->in6p_laddr;
		faddr = &inp->in6p_faddr;
		fport = inp->inp_fport;
	}

	if (af == AF_INET)
		hlen = sizeof(struct ip);

	/*
	 * Calculate data length and get a mbuf
	 * for UDP and IP6 headers.
	 */
	M_PREPEND(m, hlen + sizeof(struct udphdr), M_NOWAIT);
	if (m == NULL) {
		error = ENOBUFS;
		goto release;
	}

	/*
	 * Stuff checksum and output datagram.
	 */
	udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
	udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
	udp6->uh_dport = fport;
	if (nxt == IPPROTO_UDPLITE) {
		struct udpcb *up;

		up = intoudpcb(inp);
		cscov = up->u_txcslen;
		if (cscov >= plen)
			cscov = 0;
		udp6->uh_ulen = htons(cscov);
		/*
		 * For UDP-Lite, checksum coverage length of zero means
		 * the entire UDPLite packet is covered by the checksum.
		 */
		cscov_partial = (cscov == 0) ? 0 : 1;
	} else if (plen <= 0xffff)
		udp6->uh_ulen = htons((u_short)plen);
	else
		udp6->uh_ulen = 0;
	udp6->uh_sum = 0;

	switch (af) {
	case AF_INET6:
		ip6 = mtod(m, struct ip6_hdr *);
		ip6->ip6_flow	= inp->inp_flow & IPV6_FLOWINFO_MASK;
		ip6->ip6_vfc	&= ~IPV6_VERSION_MASK;
		ip6->ip6_vfc	|= IPV6_VERSION;
		ip6->ip6_plen	= htons((u_short)plen);
		ip6->ip6_nxt	= nxt;
		ip6->ip6_hlim	= in6_selecthlim(inp, NULL);
		ip6->ip6_src	= *laddr;
		ip6->ip6_dst	= *faddr;

		if (cscov_partial) {
			if ((udp6->uh_sum = in6_cksum_partial(m, nxt,
			    sizeof(struct ip6_hdr), plen, cscov)) == 0)
				udp6->uh_sum = 0xffff;
		} else {
			udp6->uh_sum = in6_cksum_pseudo(ip6, plen, nxt, 0);
			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
		}

#ifdef	RSS
		{
			uint32_t hash_val, hash_type;
			uint8_t pr;

			pr = inp->inp_socket->so_proto->pr_protocol;
			/*
			 * Calculate an appropriate RSS hash for UDP and
			 * UDP Lite.
			 *
			 * The called function will take care of figuring out
			 * whether a 2-tuple or 4-tuple hash is required based
			 * on the currently configured scheme.
			 *
			 * Later later on connected socket values should be
			 * cached in the inpcb and reused, rather than constantly
			 * re-calculating it.
			 *
			 * UDP Lite is a different protocol number and will
			 * likely end up being hashed as a 2-tuple until
			 * RSS / NICs grow UDP Lite protocol awareness.
			 */
			if (rss_proto_software_hash_v6(faddr, laddr, fport,
			    inp->inp_lport, pr, &hash_val, &hash_type) == 0) {
				m->m_pkthdr.flowid = hash_val;
				M_HASHTYPE_SET(m, hash_type);
			}
		}
#endif
		flags = 0;
#ifdef	RSS
		/*
		 * Don't override with the inp cached flowid.
		 *
		 * Until the whole UDP path is vetted, it may actually
		 * be incorrect.
		 */
		flags |= IP_NODEFAULTFLOWID;
#endif

		UDP_PROBE(send, NULL, inp, ip6, inp, udp6);
		UDPSTAT_INC(udps_opackets);
		error = ip6_output(m, optp, &inp->inp_route6, flags,
		    inp->in6p_moptions, NULL, inp);
		break;
	case AF_INET:
		error = EAFNOSUPPORT;
		goto release;
	}
	goto releaseopt;

release:
	m_freem(m);

releaseopt:
	if (control) {
		ip6_clearpktopts(&opt, -1);
		m_freem(control);
	}
	return (error);
}
Example #6
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);
}