udp6_usrreq.c

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//==========================================================================
//
//      src/sys/netinet6/udp6_usrreq.c
//
//==========================================================================
//####BSDCOPYRIGHTBEGIN####
//
// -------------------------------------------
//
// Portions of this software may have been derived from OpenBSD, 
// FreeBSD or other sources, and are covered by the appropriate
// copyright disclaimers included herein.
//
// Portions created by Red Hat are
// Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
//
// -------------------------------------------
//
//####BSDCOPYRIGHTEND####
//==========================================================================

/*	$FreeBSD: src/sys/netinet6/udp6_usrreq.c,v 1.6.2.6 2001/07/29 19:32:40 ume Exp $	*/
/*	$KAME: udp6_usrreq.c,v 1.43 2001/11/12 05:04:16 jinmei Exp $	*/

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Copyright (c) 1982, 1986, 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)udp_var.h	8.1 (Berkeley) 6/10/93
 */

#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/errno.h>

#include <net/if.h>
#include <net/route.h>
#include <net/if_types.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_pcb.h>
#include <netinet/icmp6.h>
#include <netinet6/udp6_var.h>
#include <netinet6/ip6protosw.h>

#ifdef IPSEC
#include <netinet6/ipsec.h>
#endif /* IPSEC */

/*
 * UDP protocol inplementation.
 * Per RFC 768, August, 1980.
 */

extern	struct protosw inetsw[];
static	int udp6_detach __P((struct socket *so));

int
udp6_input(mp, offp, proto)
	struct mbuf **mp;
	int *offp, proto;
{
	struct mbuf *m = *mp;
	register struct ip6_hdr *ip6;
	register struct udphdr *uh;
	register struct inpcb *in6p;
	struct ip6_recvpktopts opts;
	int off = *offp;
	int plen, ulen;
	struct sockaddr_in6 udp_in6;

	bzero(&opts, sizeof(opts));

	ip6 = mtod(m, struct ip6_hdr *);

#if defined(NFAITH) && 0 < NFAITH
	if (faithprefix(&ip6->ip6_dst)) {
		/* XXX send icmp6 host/port unreach? */
		m_freem(m);
		return IPPROTO_DONE;
	}
#endif

#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.udps_ipackets++;

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

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

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

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

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

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

		/*
		 * Construct sockaddr format source address.
		 */
		init_sin6(&udp_in6, m); /* general init */
		udp_in6.sin6_port = uh->uh_sport;
		/*
		 * KAME note: traditionally we dropped udpiphdr from mbuf here.
		 * We need udphdr for IPsec processing so we do that later.
		 */

		/*
		 * Locate pcb(s) for datagram.
		 * (Algorithm copied from raw_intr().)
		 */
		last = NULL;
		LIST_FOREACH(in6p, &udb, inp_list) {
			if ((in6p->inp_vflag & INP_IPV6) == 0)
				continue;
			if (in6p->in6p_lport != uh->uh_dport)
				continue;
			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr,
							&ip6->ip6_dst))
					continue;
			}
			if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
				if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr,
							&ip6->ip6_src) ||
				   in6p->in6p_fport != uh->uh_sport)
					continue;
			}

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

#ifdef IPSEC
				/*
				 * Check AH/ESP integrity.
				 */
				if (ipsec6_in_reject_so(m, last->inp_socket))
					ipsec6stat.in_polvio++;
					/* do not inject data into pcb */
				else
#endif /* IPSEC */
				if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
					/*
					 * KAME NOTE: do not
					 * m_copy(m, offset, ...) above.
					 * sbappendaddr() expects M_PKTHDR,
					 * and m_copy() will copy M_PKTHDR
					 * only if offset is 0.
					 */
					if (last->in6p_flags & IN6P_CONTROLOPTS
					    || last->in6p_socket->so_options & SO_TIMESTAMP)
						ip6_savecontrol(last, ip6, n,
								&opts, NULL);

					m_adj(n, off + sizeof(struct udphdr));
					if (sbappendaddr(&last->in6p_socket->so_rcv,
							(struct sockaddr *)&udp_in6,
							n, opts.head) == 0) {
						m_freem(n);
						if (opts.head)
							m_freem(opts.head);
						udpstat.udps_fullsock++;
					} else
						sorwakeup(last->in6p_socket);
					bzero(&opts, sizeof(opts));
				}
			}
			last = in6p;
			/*
			 * Don't look for additional matches if this one does
			 * not have either the SO_REUSEPORT or SO_REUSEADDR
			 * socket options set.  This heuristic avoids searching
			 * through all pcbs in the common case of a non-shared
			 * port.  It assumes that an application will never
			 * clear these options after setting them.
			 */
			if ((last->in6p_socket->so_options &
			     (SO_REUSEPORT|SO_REUSEADDR)) == 0)
				break;
		}

		if (last == NULL) {
			/*
			 * No matching pcb found; discard datagram.
			 * (No need to send an ICMP Port Unreachable
			 * for a broadcast or multicast datgram.)
			 */
			udpstat.udps_noport++;
			udpstat.udps_noportmcast++;
			goto bad;
		}
#ifdef IPSEC
		/*
		 * Check AH/ESP integrity.
		 */
		if (ipsec6_in_reject_so(m, last->inp_socket)) {
			ipsec6stat.in_polvio++;
			goto bad;
		}
#endif /* IPSEC */
		if (last->in6p_flags & IN6P_CONTROLOPTS
		    || last->in6p_socket->so_options & SO_TIMESTAMP)
			ip6_savecontrol(last, ip6, m, &opts, NULL);

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

			strcpy(buf, ip6_sprintf(&ip6->ip6_dst));
			log(LOG_INFO,
			    "Connection attempt to UDP %s:%d from %s:%d\n",
			    buf, ntohs(uh->uh_dport),
			    ip6_sprintf(&ip6->ip6_src), ntohs(uh->uh_sport));
		}
		udpstat.udps_noport++;
		if (m->m_flags & M_MCAST) {
			printf("UDP6: M_MCAST is set in a unicast packet.\n");
			udpstat.udps_noportmcast++;
			goto bad;
		}
		icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
		return IPPROTO_DONE;
	}
#ifdef IPSEC
	/*
	 * Check AH/ESP integrity.
	 */
	if (ipsec6_in_reject_so(m, in6p->in6p_socket)) {
		ipsec6stat.in_polvio++;
		goto bad;