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IABSD.fr/src/sys/netinet/udp_usrreq.c

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  • Author : yasuoka
    Date : 2022-01-04 06:32:39
    Hash : 4d544115
    Message : Add `ipsec_flows_mtx' mutex(9) to protect `ipsp_ids_*' list and trees. ipsp_ids_lookup() returns `ids' with bumped reference counter. original diff from mvs ok mvs

  • sys/netinet/udp_usrreq.c
  • /*	$OpenBSD: udp_usrreq.c,v 1.268 2022/01/04 06:32:40 yasuoka Exp $	*/
    /*	$NetBSD: udp_usrreq.c,v 1.28 1996/03/16 23:54:03 christos Exp $	*/
    
    /*
     * Copyright (c) 1982, 1986, 1988, 1990, 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. 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.
     *
     *	@(#)COPYRIGHT	1.1 (NRL) 17 January 1995
     *
     * NRL grants permission for redistribution and use in source and binary
     * forms, with or without modification, of the software and documentation
     * created at NRL 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 acknowledgements:
     * 	This product includes software developed by the University of
     * 	California, Berkeley and its contributors.
     * 	This product includes software developed at the Information
     * 	Technology Division, US Naval Research Laboratory.
     * 4. Neither the name of the NRL nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL 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 NRL 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.
     *
     * The views and conclusions contained in the software and documentation
     * are those of the authors and should not be interpreted as representing
     * official policies, either expressed or implied, of the US Naval
     * Research Laboratory (NRL).
     */
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/mbuf.h>
    #include <sys/protosw.h>
    #include <sys/socket.h>
    #include <sys/socketvar.h>
    #include <sys/sysctl.h>
    #include <sys/domain.h>
    
    #include <net/if.h>
    #include <net/if_var.h>
    #include <net/if_media.h>
    #include <net/route.h>
    
    #include <netinet/in.h>
    #include <netinet/in_var.h>
    #include <netinet/ip.h>
    #include <netinet/in_pcb.h>
    #include <netinet/ip_var.h>
    #include <netinet/ip_icmp.h>
    #include <netinet/udp.h>
    #include <netinet/udp_var.h>
    
    #ifdef IPSEC
    #include <netinet/ip_ipsp.h>
    #include <netinet/ip_esp.h>
    #endif
    
    #ifdef INET6
    #include <netinet6/in6_var.h>
    #include <netinet6/ip6_var.h>
    #include <netinet6/ip6protosw.h>
    #endif /* INET6 */
    
    #include "pf.h"
    #if NPF > 0
    #include <net/pfvar.h>
    #endif
    
    #ifdef PIPEX 
    #include <netinet/if_ether.h>
    #include <net/pipex.h>
    #endif
    
    #include "vxlan.h"
    #if NVXLAN > 0
    #include <net/if_vxlan.h>
    #endif
    
    /*
     * UDP protocol implementation.
     * Per RFC 768, August, 1980.
     */
    int	udpcksum = 1;
    
    u_int	udp_sendspace = 9216;		/* really max datagram size */
    u_int	udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in));
    					/* 40 1K datagrams */
    
    const struct sysctl_bounded_args udpctl_vars[] = {
    	{ UDPCTL_CHECKSUM, &udpcksum, 0, 1 },
    	{ UDPCTL_RECVSPACE, &udp_recvspace, 0, INT_MAX },
    	{ UDPCTL_SENDSPACE, &udp_sendspace, 0, INT_MAX },
    };
    
    struct	inpcbtable udbtable;
    struct	cpumem *udpcounters;
    
    void	udp_sbappend(struct inpcb *, struct mbuf *, struct ip *,
    	    struct ip6_hdr *, int, struct udphdr *, struct sockaddr *,
    	    u_int32_t);
    int	udp_output(struct inpcb *, struct mbuf *, struct mbuf *, struct mbuf *);
    void	udp_notify(struct inpcb *, int);
    int	udp_sysctl_udpstat(void *, size_t *, void *);
    
    #ifndef	UDB_INITIAL_HASH_SIZE
    #define	UDB_INITIAL_HASH_SIZE	128
    #endif
    
    void
    udp_init(void)
    {
    	udpcounters = counters_alloc(udps_ncounters);
    	in_pcbinit(&udbtable, UDB_INITIAL_HASH_SIZE);
    }
    
    int
    udp_input(struct mbuf **mp, int *offp, int proto, int af)
    {
    	struct mbuf *m = *mp;
    	int iphlen = *offp;
    	struct ip *ip = NULL;
    	struct udphdr *uh;
    	struct inpcb *inp = NULL;
    	struct ip save_ip;
    	int len;
    	u_int16_t savesum;
    	union {
    		struct sockaddr sa;
    		struct sockaddr_in sin;
    #ifdef INET6
    		struct sockaddr_in6 sin6;
    #endif /* INET6 */
    	} srcsa, dstsa;
    	struct ip6_hdr *ip6 = NULL;
    	u_int32_t ipsecflowinfo = 0;
    
    	udpstat_inc(udps_ipackets);
    
    	IP6_EXTHDR_GET(uh, struct udphdr *, m, iphlen, sizeof(struct udphdr));
    	if (!uh) {
    		udpstat_inc(udps_hdrops);
    		return IPPROTO_DONE;
    	}
    
    	/* Check for illegal destination port 0 */
    	if (uh->uh_dport == 0) {
    		udpstat_inc(udps_noport);
    		goto bad;
    	}
    
    	/*
    	 * Make mbuf data length reflect UDP length.
    	 * If not enough data to reflect UDP length, drop.
    	 */
    	len = ntohs((u_int16_t)uh->uh_ulen);
    	switch (af) {
    	case AF_INET:
    		if (m->m_pkthdr.len - iphlen != len) {
    			if (len > (m->m_pkthdr.len - iphlen) ||
    			    len < sizeof(struct udphdr)) {
    				udpstat_inc(udps_badlen);
    				goto bad;
    			}
    			m_adj(m, len - (m->m_pkthdr.len - iphlen));
    		}
    		ip = mtod(m, struct ip *);
    		/*
    		 * Save a copy of the IP header in case we want restore it
    		 * for sending an ICMP error message in response.
    		 */
    		save_ip = *ip;
    		break;
    #ifdef INET6
    	case AF_INET6:
    		/* jumbograms */
    		if (len == 0 && m->m_pkthdr.len - iphlen > 0xffff)
    			len = m->m_pkthdr.len - iphlen;
    		if (len != m->m_pkthdr.len - iphlen) {
    			udpstat_inc(udps_badlen);
    			goto bad;
    		}
    		ip6 = mtod(m, struct ip6_hdr *);
    		break;
    #endif /* INET6 */
    	default:
    		unhandled_af(af);
    	}
    
    	/*
    	 * Checksum extended UDP header and data.
    	 * from W.R.Stevens: check incoming udp cksums even if
    	 *	udpcksum is not set.
    	 */
    	savesum = uh->uh_sum;
    	if (uh->uh_sum == 0) {
    		udpstat_inc(udps_nosum);
    #ifdef INET6
    		/*
    		 * In IPv6, the UDP checksum is ALWAYS used.
    		 */
    		if (ip6)
    			goto bad;
    #endif /* INET6 */
    	} else {
    		if ((m->m_pkthdr.csum_flags & M_UDP_CSUM_IN_OK) == 0) {
    			if (m->m_pkthdr.csum_flags & M_UDP_CSUM_IN_BAD) {
    				udpstat_inc(udps_badsum);
    				goto bad;
    			}
    			udpstat_inc(udps_inswcsum);
    
    			if (ip)
    				uh->uh_sum = in4_cksum(m, IPPROTO_UDP,
    				    iphlen, len);
    #ifdef INET6
    			else if (ip6)
    				uh->uh_sum = in6_cksum(m, IPPROTO_UDP,
    				    iphlen, len);
    #endif /* INET6 */
    			if (uh->uh_sum != 0) {
    				udpstat_inc(udps_badsum);
    				goto bad;
    			}
    		}
    	}
    
    #ifdef IPSEC
    	if (udpencap_enable && udpencap_port && esp_enable &&
    #if NPF > 0
    	    !(m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) &&
    #endif
    	    uh->uh_dport == htons(udpencap_port)) {
    		u_int32_t spi;
    		int skip = iphlen + sizeof(struct udphdr);
    
    		if (m->m_pkthdr.len - skip < sizeof(u_int32_t)) {
    			/* packet too short */
    			m_freem(m);
    			return IPPROTO_DONE;
    		}
    		m_copydata(m, skip, sizeof(u_int32_t), (caddr_t) &spi);
    		/*
    		 * decapsulate if the SPI is not zero, otherwise pass
    		 * to userland
    		 */
    		if (spi != 0) {
    			int protoff;
    
    			if ((m = *mp = m_pullup(m, skip)) == NULL) {
    				udpstat_inc(udps_hdrops);
    				return IPPROTO_DONE;
    			}
    
    			/* remove the UDP header */
    			bcopy(mtod(m, u_char *),
    			    mtod(m, u_char *) + sizeof(struct udphdr), iphlen);
    			m_adj(m, sizeof(struct udphdr));
    			skip -= sizeof(struct udphdr);
    
    			espstat_inc(esps_udpencin);
    			protoff = af == AF_INET ? offsetof(struct ip, ip_p) :
    			    offsetof(struct ip6_hdr, ip6_nxt);
    			return ipsec_common_input(mp, skip, protoff,
    			    af, IPPROTO_ESP, 1);
    		}
    	}
    #endif /* IPSEC */
    
    	switch (af) {
    	case AF_INET:
    		bzero(&srcsa, sizeof(struct sockaddr_in));
    		srcsa.sin.sin_len = sizeof(struct sockaddr_in);
    		srcsa.sin.sin_family = AF_INET;
    		srcsa.sin.sin_port = uh->uh_sport;
    		srcsa.sin.sin_addr = ip->ip_src;
    
    		bzero(&dstsa, sizeof(struct sockaddr_in));
    		dstsa.sin.sin_len = sizeof(struct sockaddr_in);
    		dstsa.sin.sin_family = AF_INET;
    		dstsa.sin.sin_port = uh->uh_dport;
    		dstsa.sin.sin_addr = ip->ip_dst;
    		break;
    #ifdef INET6
    	case AF_INET6:
    		bzero(&srcsa, sizeof(struct sockaddr_in6));
    		srcsa.sin6.sin6_len = sizeof(struct sockaddr_in6);
    		srcsa.sin6.sin6_family = AF_INET6;
    		srcsa.sin6.sin6_port = uh->uh_sport;
    #if 0 /*XXX inbound flowinfo */
    		srcsa.sin6.sin6_flowinfo = htonl(0x0fffffff) & ip6->ip6_flow;
    #endif
    		/* KAME hack: recover scopeid */
    		in6_recoverscope(&srcsa.sin6, &ip6->ip6_src);
    
    		bzero(&dstsa, sizeof(struct sockaddr_in6));
    		dstsa.sin6.sin6_len = sizeof(struct sockaddr_in6);
    		dstsa.sin6.sin6_family = AF_INET6;
    		dstsa.sin6.sin6_port = uh->uh_dport;
    #if 0 /*XXX inbound flowinfo */
    		dstsa.sin6.sin6_flowinfo = htonl(0x0fffffff) & ip6->ip6_flow;
    #endif
    		/* KAME hack: recover scopeid */
    		in6_recoverscope(&dstsa.sin6, &ip6->ip6_dst);
    		break;
    #endif /* INET6 */
    	}
    
    #if NVXLAN > 0
    	if (vxlan_enable > 0 &&
    #if NPF > 0
    	    !(m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) &&
    #endif
    	    vxlan_lookup(m, uh, iphlen, &srcsa.sa, &dstsa.sa) != 0)
    		return IPPROTO_DONE;
    #endif
    
    	if (m->m_flags & (M_BCAST|M_MCAST)) {
    		struct inpcb *last;
    		/*
    		 * Deliver a multicast or broadcast 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 multi/broadcasts 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?)
    		 */
    
    		/*
    		 * Locate pcb(s) for datagram.
    		 * (Algorithm copied from raw_intr().)
    		 */
    		last = NULL;
    		NET_ASSERT_LOCKED();
    		TAILQ_FOREACH(inp, &udbtable.inpt_queue, inp_queue) {
    			if (inp->inp_socket->so_state & SS_CANTRCVMORE)
    				continue;
    #ifdef INET6
    			/* don't accept it if AF does not match */
    			if (ip6 && !(inp->inp_flags & INP_IPV6))
    				continue;
    			if (!ip6 && (inp->inp_flags & INP_IPV6))
    				continue;
    #endif
    			if (rtable_l2(inp->inp_rtableid) !=
    			    rtable_l2(m->m_pkthdr.ph_rtableid))
    				continue;
    			if (inp->inp_lport != uh->uh_dport)
    				continue;
    #ifdef INET6
    			if (ip6) {
    				if (inp->inp_ip6_minhlim &&
    				    inp->inp_ip6_minhlim > ip6->ip6_hlim)
    					continue;
    				if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_laddr6))
    					if (!IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6,
    					    &ip6->ip6_dst))
    						continue;
    			} else
    #endif /* INET6 */
    			{
    				if (inp->inp_ip_minttl &&
    				    inp->inp_ip_minttl > ip->ip_ttl)
    					continue;
    
    				if (inp->inp_laddr.s_addr != INADDR_ANY) {
    					if (inp->inp_laddr.s_addr !=
    					    ip->ip_dst.s_addr)
    						continue;
    				}
    			}
    #ifdef INET6
    			if (ip6) {
    				if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6))
    					if (!IN6_ARE_ADDR_EQUAL(&inp->inp_faddr6,
    					    &ip6->ip6_src) ||
    					    inp->inp_fport != uh->uh_sport)
    						continue;
    			} else
    #endif /* INET6 */
    			if (inp->inp_faddr.s_addr != INADDR_ANY) {
    				if (inp->inp_faddr.s_addr !=
    				    ip->ip_src.s_addr ||
    				    inp->inp_fport != uh->uh_sport)
    					continue;
    			}
    
    			if (last != NULL) {
    				struct mbuf *n;
    
    				n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
    				if (n != NULL) {
    					udp_sbappend(last, n, ip, ip6, iphlen,
    					    uh, &srcsa.sa, 0);
    				}
    			}
    			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);
    			goto bad;
    		}
    
    		udp_sbappend(last, m, ip, ip6, iphlen, uh, &srcsa.sa, 0);
    		return IPPROTO_DONE;
    	}
    	/*
    	 * Locate pcb for datagram.
    	 */
    #if NPF > 0
    	inp = pf_inp_lookup(m);
    #endif
    	if (inp == NULL) {
    #ifdef INET6
    		if (ip6)
    			inp = in6_pcbhashlookup(&udbtable, &ip6->ip6_src,
    			    uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
    			    m->m_pkthdr.ph_rtableid);
    		else
    #endif /* INET6 */
    		inp = in_pcbhashlookup(&udbtable, ip->ip_src, uh->uh_sport,
    		    ip->ip_dst, uh->uh_dport, m->m_pkthdr.ph_rtableid);
    	}
    	if (inp == NULL) {
    		udpstat_inc(udps_pcbhashmiss);
    #ifdef INET6
    		if (ip6) {
    			inp = in6_pcblookup_listen(&udbtable, &ip6->ip6_dst,
    			    uh->uh_dport, m, m->m_pkthdr.ph_rtableid);
    		} else
    #endif /* INET6 */
    		inp = in_pcblookup_listen(&udbtable, ip->ip_dst,
    		    uh->uh_dport, m, m->m_pkthdr.ph_rtableid);
    	}
    
    #ifdef IPSEC
    	if (ipsec_in_use) {
    		struct m_tag *mtag;
    		struct tdb_ident *tdbi;
    		struct tdb *tdb;
    		int error;
    
    		mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
    		if (mtag != NULL) {
    			tdbi = (struct tdb_ident *)(mtag + 1);
    			tdb = gettdb(tdbi->rdomain, tdbi->spi,
    			    &tdbi->dst, tdbi->proto);
    		} else
    			tdb = NULL;
    		error = ipsp_spd_lookup(m, af, iphlen, IPSP_DIRECTION_IN,
    		    tdb, inp, NULL, NULL);
    		if (error) {
    			udpstat_inc(udps_nosec);
    			tdb_unref(tdb);
    			goto bad;
    		}
    		/* create ipsec options while we know that tdb cannot be modified */
    		if (tdb && tdb->tdb_ids)
    			ipsecflowinfo = tdb->tdb_ids->id_flow;
    		tdb_unref(tdb);
    	}
    #endif /*IPSEC */
    
    	if (inp == NULL) {
    		udpstat_inc(udps_noport);
    		if (m->m_flags & (M_BCAST | M_MCAST)) {
    			udpstat_inc(udps_noportbcast);
    			goto bad;
    		}
    #ifdef INET6
    		if (ip6) {
    			uh->uh_sum = savesum;
    			icmp6_error(m, ICMP6_DST_UNREACH,
    			    ICMP6_DST_UNREACH_NOPORT,0);
    		} else
    #endif /* INET6 */
    		{
    			*ip = save_ip;
    			uh->uh_sum = savesum;
    			icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT,
    			    0, 0);
    		}
    		return IPPROTO_DONE;
    	}
    
    	KASSERT(sotoinpcb(inp->inp_socket) == inp);
    	soassertlocked(inp->inp_socket);
    
    #ifdef INET6
    	if (ip6 && inp->inp_ip6_minhlim &&
    	    inp->inp_ip6_minhlim > ip6->ip6_hlim) {
    		goto bad;
    	} else
    #endif
    	if (ip && inp->inp_ip_minttl &&
    	    inp->inp_ip_minttl > ip->ip_ttl) {
    		goto bad;
    	}
    
    #if NPF > 0
    	if (inp->inp_socket->so_state & SS_ISCONNECTED)
    		pf_inp_link(m, inp);
    #endif
    
    #ifdef PIPEX
    	if (pipex_enable && inp->inp_pipex) {
    		struct pipex_session *session;
    		int off = iphlen + sizeof(struct udphdr);
    		if ((session = pipex_l2tp_lookup_session(m, off)) != NULL) {
    			if ((m = *mp = pipex_l2tp_input(m, off, session,
    			    ipsecflowinfo)) == NULL) {
    				/* the packet is handled by PIPEX */
    				return IPPROTO_DONE;
    			}
    		}
    	}
    #endif
    
    	udp_sbappend(inp, m, ip, ip6, iphlen, uh, &srcsa.sa, ipsecflowinfo);
    	return IPPROTO_DONE;
    bad:
    	m_freem(m);
    	return IPPROTO_DONE;
    }
    
    void
    udp_sbappend(struct inpcb *inp, struct mbuf *m, struct ip *ip,
        struct ip6_hdr *ip6, int hlen, struct udphdr *uh,
        struct sockaddr *srcaddr, u_int32_t ipsecflowinfo)
    {
    	struct socket *so = inp->inp_socket;
    	struct mbuf *opts = NULL;
    
    	hlen += sizeof(*uh);
    
    	if (inp->inp_upcall != NULL) {
    		m = (*inp->inp_upcall)(inp->inp_upcall_arg, m,
    		    ip, ip6, uh, hlen);
    		if (m == NULL)
    			return;
    	}
    
    #ifdef INET6
    	if (ip6 && (inp->inp_flags & IN6P_CONTROLOPTS ||
    	    so->so_options & SO_TIMESTAMP))
    		ip6_savecontrol(inp, m, &opts);
    #endif /* INET6 */
    	if (ip && (inp->inp_flags & INP_CONTROLOPTS ||
    	    so->so_options & SO_TIMESTAMP))
    		ip_savecontrol(inp, &opts, ip, m);
    #ifdef INET6
    	if (ip6 && (inp->inp_flags & IN6P_RECVDSTPORT)) {
    		struct mbuf **mp = &opts;
    
    		while (*mp)
    			mp = &(*mp)->m_next;
    		*mp = sbcreatecontrol((caddr_t)&uh->uh_dport, sizeof(u_int16_t),
    		    IPV6_RECVDSTPORT, IPPROTO_IPV6);
    	}
    #endif /* INET6 */
    	if (ip && (inp->inp_flags & INP_RECVDSTPORT)) {
    		struct mbuf **mp = &opts;
    
    		while (*mp)
    			mp = &(*mp)->m_next;
    		*mp = sbcreatecontrol((caddr_t)&uh->uh_dport, sizeof(u_int16_t),
    		    IP_RECVDSTPORT, IPPROTO_IP);
    	}
    #ifdef IPSEC
    	if (ipsecflowinfo && (inp->inp_flags & INP_IPSECFLOWINFO)) {
    		struct mbuf **mp = &opts;
    
    		while (*mp)
    			mp = &(*mp)->m_next;
    		*mp = sbcreatecontrol((caddr_t)&ipsecflowinfo,
    		    sizeof(u_int32_t), IP_IPSECFLOWINFO, IPPROTO_IP);
    	}
    #endif
    	m_adj(m, hlen);
    	if (sbappendaddr(so, &so->so_rcv, srcaddr, m, opts) == 0) {
    		udpstat_inc(udps_fullsock);
    		m_freem(m);
    		m_freem(opts);
    		return;
    	}
    	sorwakeup(so);
    }
    
    /*
     * Notify a udp user of an asynchronous error;
     * just wake up so that he can collect error status.
     */
    void
    udp_notify(struct inpcb *inp, int errno)
    {
    	inp->inp_socket->so_error = errno;
    	sorwakeup(inp->inp_socket);
    	sowwakeup(inp->inp_socket);
    }
    
    #ifdef INET6
    void
    udp6_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *d)
    {
    	struct udphdr uh;
    	struct sockaddr_in6 sa6;
    	struct ip6_hdr *ip6;
    	struct mbuf *m;
    	int off;
    	void *cmdarg;
    	struct ip6ctlparam *ip6cp = NULL;
    	struct udp_portonly {
    		u_int16_t uh_sport;
    		u_int16_t uh_dport;
    	} *uhp;
    	void (*notify)(struct inpcb *, int) = udp_notify;
    
    	if (sa == NULL)
    		return;
    	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 = in_rtchange, d = NULL;
    	else if (cmd == PRC_HOSTDEAD)
    		d = NULL;
    	else if (cmd == PRC_MSGSIZE)
    		; /* special code is present, see below */
    	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;
    	} else {
    		m = NULL;
    		ip6 = NULL;
    		cmdarg = NULL;
    		/* XXX: translate addresses into internal form */
    		sa6 = *satosin6(sa);
    		if (in6_embedscope(&sa6.sin6_addr, &sa6, NULL)) {
    			/* should be impossible */
    			return;
    		}
    	}
    
    	if (ip6cp && ip6cp->ip6c_finaldst) {
    		bzero(&sa6, sizeof(sa6));
    		sa6.sin6_family = AF_INET6;
    		sa6.sin6_len = sizeof(sa6);
    		sa6.sin6_addr = *ip6cp->ip6c_finaldst;
    		/* XXX: assuming M is valid in this case */
    		sa6.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.ph_ifidx,
    		    ip6cp->ip6c_finaldst);
    		if (in6_embedscope(ip6cp->ip6c_finaldst, &sa6, NULL)) {
    			/* should be impossible */
    			return;
    		}
    	} else {
    		/* XXX: translate addresses into internal form */
    		sa6 = *satosin6(sa);
    		if (in6_embedscope(&sa6.sin6_addr, &sa6, NULL)) {
    			/* should be impossible */
    			return;
    		}
    	}
    
    	if (ip6) {
    		/*
    		 * XXX: We assume that when IPV6 is non NULL,
    		 * M and OFF are valid.
    		 */
    		struct sockaddr_in6 sa6_src;
    
    		/* 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);
    
    		bzero(&sa6_src, sizeof(sa6_src));
    		sa6_src.sin6_family = AF_INET6;
    		sa6_src.sin6_len = sizeof(sa6_src);
    		sa6_src.sin6_addr = ip6->ip6_src;
    		sa6_src.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.ph_ifidx,
    		    &ip6->ip6_src);
    		if (in6_embedscope(&sa6_src.sin6_addr, &sa6_src, NULL)) {
    			/* should be impossible */
    			return;
    		}
    
    		if (cmd == PRC_MSGSIZE) {
    			int valid = 0;
    
    			/*
    			 * Check to see if we have a valid UDP socket
    			 * corresponding to the address in the ICMPv6 message
    			 * payload.
    			 */
    			if (in6_pcbhashlookup(&udbtable, &sa6.sin6_addr,
    			    uh.uh_dport, &sa6_src.sin6_addr, uh.uh_sport,
    			    rdomain))
    				valid = 1;
    #if 0
    			/*
    			 * As the use of sendto(2) is fairly popular,
    			 * we may want to allow non-connected pcb too.
    			 * But it could be too weak against attacks...
    			 * We should at least check if the local address (= s)
    			 * is really ours.
    			 */
    			else if (in6_pcblookup_listen(&udbtable,
    			    &sa6_src.sin6_addr, uh.uh_sport, NULL,
    			    rdomain))
    				valid = 1;
    #endif
    
    			/*
    			 * Depending on the value of "valid" and routing table
    			 * size (mtudisc_{hi,lo}wat), we will:
    			 * - recalculate the new MTU and create the
    			 *   corresponding routing entry, or
    			 * - ignore the MTU change notification.
    			 */
    			icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
    
    			/*
    			 * regardless of if we called icmp6_mtudisc_update(),
    			 * we need to call in6_pcbnotify(), to notify path
    			 * MTU change to the userland (2292bis-02), because
    			 * some unconnected sockets may share the same
    			 * destination and want to know the path MTU.
    			 */
    		}
    
    		(void) in6_pcbnotify(&udbtable, &sa6, uh.uh_dport,
    		    &sa6_src, uh.uh_sport, rdomain, cmd, cmdarg, notify);
    	} else {
    		(void) in6_pcbnotify(&udbtable, &sa6, 0,
    		    &sa6_any, 0, rdomain, cmd, cmdarg, notify);
    	}
    }
    #endif
    
    void
    udp_ctlinput(int cmd, struct sockaddr *sa, u_int rdomain, void *v)
    {
    	struct ip *ip = v;
    	struct udphdr *uhp;
    	struct in_addr faddr;
    	struct inpcb *inp;
    	void (*notify)(struct inpcb *, int) = udp_notify;
    	int errno;
    
    	if (sa == NULL)
    		return;
    	if (sa->sa_family != AF_INET ||
    	    sa->sa_len != sizeof(struct sockaddr_in))
    		return;
    	faddr = satosin(sa)->sin_addr;
    	if (faddr.s_addr == INADDR_ANY)
    		return;
    
    	if ((unsigned)cmd >= PRC_NCMDS)
    		return;
    	errno = inetctlerrmap[cmd];
    	if (PRC_IS_REDIRECT(cmd))
    		notify = in_rtchange, ip = 0;
    	else if (cmd == PRC_HOSTDEAD)
    		ip = 0;
    	else if (errno == 0)
    		return;
    	if (ip) {
    		uhp = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
    
    #ifdef IPSEC
    		/* PMTU discovery for udpencap */
    		if (cmd == PRC_MSGSIZE && ip_mtudisc && udpencap_enable &&
    		    udpencap_port && uhp->uh_sport == htons(udpencap_port)) {
    			udpencap_ctlinput(cmd, sa, rdomain, v);
    			return;
    		}
    #endif
    		inp = in_pcbhashlookup(&udbtable,
    		    ip->ip_dst, uhp->uh_dport, ip->ip_src, uhp->uh_sport,
    		    rdomain);
    		if (inp && inp->inp_socket != NULL)
    			notify(inp, errno);
    	} else
    		in_pcbnotifyall(&udbtable, sa, rdomain, errno, notify);
    }
    
    int
    udp_output(struct inpcb *inp, struct mbuf *m, struct mbuf *addr,
        struct mbuf *control)
    {
    	struct sockaddr_in *sin = NULL;
    	struct udpiphdr *ui;
    	u_int32_t ipsecflowinfo = 0;
    	struct sockaddr_in src_sin;
    	int len = m->m_pkthdr.len;
    	struct in_addr *laddr;
    	int error = 0;
    
    #ifdef DIAGNOSTIC
    	if ((inp->inp_flags & INP_IPV6) != 0)
    		panic("IPv6 inpcb to %s", __func__);
    #endif
    
    	/*
    	 * Compute the packet length of the IP header, and
    	 * punt if the length looks bogus.
    	 */
    	if ((len + sizeof(struct udpiphdr)) > IP_MAXPACKET) {
    		error = EMSGSIZE;
    		goto release;
    	}
    
    	memset(&src_sin, 0, sizeof(src_sin));
    
    	if (control) {
    		u_int clen;
    		struct cmsghdr *cm;
    		caddr_t cmsgs;
    
    		/*
    		 * XXX: Currently, we assume all the optional information is
    		 * stored in a single mbuf.
    		 */
    		if (control->m_next) {
    			error = EINVAL;
    			goto release;
    		}
    
    		clen = control->m_len;
    		cmsgs = mtod(control, caddr_t);
    		do {
    			if (clen < CMSG_LEN(0)) {
    				error = EINVAL;
    				goto release;
    			}
    			cm = (struct cmsghdr *)cmsgs;
    			if (cm->cmsg_len < CMSG_LEN(0) ||
    			    CMSG_ALIGN(cm->cmsg_len) > clen) {
    				error = EINVAL;
    				goto release;
    			}
    #ifdef IPSEC
    			if ((inp->inp_flags & INP_IPSECFLOWINFO) != 0 &&
    			    cm->cmsg_len == CMSG_LEN(sizeof(ipsecflowinfo)) &&
    			    cm->cmsg_level == IPPROTO_IP &&
    			    cm->cmsg_type == IP_IPSECFLOWINFO) {
    				ipsecflowinfo = *(u_int32_t *)CMSG_DATA(cm);
    			} else
    #endif
    			if (cm->cmsg_len == CMSG_LEN(sizeof(struct in_addr)) &&
    			    cm->cmsg_level == IPPROTO_IP &&
    			    cm->cmsg_type == IP_SENDSRCADDR) {
    				memcpy(&src_sin.sin_addr, CMSG_DATA(cm),
    				    sizeof(struct in_addr));
    				src_sin.sin_family = AF_INET;
    				src_sin.sin_len = sizeof(src_sin);
    				/* no check on reuse when sin->sin_port == 0 */
    				if ((error = in_pcbaddrisavail(inp, &src_sin,
    				    0, curproc)))
    					goto release;
    			}
    			clen -= CMSG_ALIGN(cm->cmsg_len);
    			cmsgs += CMSG_ALIGN(cm->cmsg_len);
    		} while (clen);
    	}
    
    	if (addr) {
    		if ((error = in_nam2sin(addr, &sin)))
    			goto release;
    		if (sin->sin_port == 0) {
    			error = EADDRNOTAVAIL;
    			goto release;
    		}
    		if (inp->inp_faddr.s_addr != INADDR_ANY) {
    			error = EISCONN;
    			goto release;
    		}
    		error = in_pcbselsrc(&laddr, sin, inp);
    		if (error)
    			goto release;
    
    		if (inp->inp_lport == 0) {
    			error = in_pcbbind(inp, NULL, curproc);
    			if (error)
    				goto release;
    		}
    
    		if (src_sin.sin_len > 0 &&
    		    src_sin.sin_addr.s_addr != INADDR_ANY &&
    		    src_sin.sin_addr.s_addr != inp->inp_laddr.s_addr) {
    			src_sin.sin_port = inp->inp_lport;
    			if (inp->inp_laddr.s_addr != INADDR_ANY &&
    			    (error =
    			    in_pcbaddrisavail(inp, &src_sin, 0, curproc)))
    				goto release;
    			laddr = &src_sin.sin_addr;
    		}
    	} else {
    		if (inp->inp_faddr.s_addr == INADDR_ANY) {
    			error = ENOTCONN;
    			goto release;
    		}
    		laddr = &inp->inp_laddr;
    	}
    
    	/*
    	 * Calculate data length and get a mbuf
    	 * for UDP and IP headers.
    	 */
    	M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT);
    	if (m == NULL) {
    		error = ENOBUFS;
    		goto bail;
    	}
    
    	/*
    	 * 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);
    	ui->ui_pr = IPPROTO_UDP;
    	ui->ui_len = htons((u_int16_t)len + sizeof (struct udphdr));
    	ui->ui_src = *laddr;
    	ui->ui_dst = sin ? sin->sin_addr : inp->inp_faddr;
    	ui->ui_sport = inp->inp_lport;
    	ui->ui_dport = sin ? sin->sin_port : inp->inp_fport;
    	ui->ui_ulen = ui->ui_len;
    	((struct ip *)ui)->ip_len = htons(sizeof (struct udpiphdr) + len);
    	((struct ip *)ui)->ip_ttl = inp->inp_ip.ip_ttl;
    	((struct ip *)ui)->ip_tos = inp->inp_ip.ip_tos;
    	if (udpcksum)
    		m->m_pkthdr.csum_flags |= M_UDP_CSUM_OUT;
    
    	udpstat_inc(udps_opackets);
    
    	/* force routing table */
    	m->m_pkthdr.ph_rtableid = inp->inp_rtableid;
    
    #if NPF > 0
    	if (inp->inp_socket->so_state & SS_ISCONNECTED)
    		pf_mbuf_link_inpcb(m, inp);
    #endif
    
    	error = ip_output(m, inp->inp_options, &inp->inp_route,
    	    (inp->inp_socket->so_options & SO_BROADCAST), inp->inp_moptions,
    	    inp, ipsecflowinfo);
    
    bail:
    	m_freem(control);
    	return (error);
    
    release:
    	m_freem(m);
    	goto bail;
    }
    
    /*ARGSUSED*/
    int
    udp_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *addr,
        struct mbuf *control, struct proc *p)
    {
    	struct inpcb *inp;
    	int error = 0;
    
    	if (req == PRU_CONTROL) {
    #ifdef INET6
    		if (sotopf(so) == PF_INET6)
    			return (in6_control(so, (u_long)m, (caddr_t)addr,
    			    (struct ifnet *)control));
    		else
    #endif /* INET6 */
    			return (in_control(so, (u_long)m, (caddr_t)addr,
    			    (struct ifnet *)control));
    	}
    
    	soassertlocked(so);
    
    	inp = sotoinpcb(so);
    	if (inp == NULL) {
    		error = EINVAL;
    		goto release;
    	}
    
    	/*
    	 * Note: need to block udp_input while changing
    	 * the udp pcb queue and/or pcb addresses.
    	 */
    	switch (req) {
    
    	case PRU_BIND:
    		error = in_pcbbind(inp, addr, p);
    		break;
    
    	case PRU_LISTEN:
    		error = EOPNOTSUPP;
    		break;
    
    	case PRU_CONNECT:
    #ifdef INET6
    		if (inp->inp_flags & INP_IPV6) {
    			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6)) {
    				error = EISCONN;
    				break;
    			}
    			error = in6_pcbconnect(inp, addr);
    		} else
    #endif /* INET6 */
    		{
    			if (inp->inp_faddr.s_addr != INADDR_ANY) {
    				error = EISCONN;
    				break;
    			}
    			error = in_pcbconnect(inp, addr);
    		}
    
    		if (error == 0)
    			soisconnected(so);
    		break;
    
    	case PRU_CONNECT2:
    		error = EOPNOTSUPP;
    		break;
    
    	case PRU_ACCEPT:
    		error = EOPNOTSUPP;
    		break;
    
    	case PRU_DISCONNECT:
    #ifdef INET6
    		if (inp->inp_flags & INP_IPV6) {
    			if (IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6)) {
    				error = ENOTCONN;
    				break;
    			}
    		} else
    #endif /* INET6 */
    		{
    			if (inp->inp_faddr.s_addr == INADDR_ANY) {
    				error = ENOTCONN;
    				break;
    			}
    		}
    
    #ifdef INET6
    		if (inp->inp_flags & INP_IPV6)
    			inp->inp_laddr6 = in6addr_any;
    		else
    #endif /* INET6 */
    			inp->inp_laddr.s_addr = INADDR_ANY;
    		in_pcbdisconnect(inp);
    
    		so->so_state &= ~SS_ISCONNECTED;		/* XXX */
    		break;
    
    	case PRU_SHUTDOWN:
    		socantsendmore(so);
    		break;
    
    	case PRU_SEND:
    #ifdef PIPEX
    		if (inp->inp_pipex) {
    			struct pipex_session *session;
    
    			if (addr != NULL) 
    				session =
    				    pipex_l2tp_userland_lookup_session(m,
    					mtod(addr, struct sockaddr *));
    			else
    #ifdef INET6
    			if (inp->inp_flags & INP_IPV6)
    				session =
    				    pipex_l2tp_userland_lookup_session_ipv6(
    					m, inp->inp_faddr6);
    			else
    #endif
    				session =
    				    pipex_l2tp_userland_lookup_session_ipv4(
    					m, inp->inp_faddr);
    			if (session != NULL)
    				if ((m = pipex_l2tp_userland_output(
    				    m, session)) == NULL) {
    					error = ENOMEM;
    					goto release;
    				}
    		}
    #endif
    
    #ifdef INET6
    		if (inp->inp_flags & INP_IPV6)
    			error = udp6_output(inp, m, addr, control);
    		else
    #endif
    			error = udp_output(inp, m, addr, control);
    		return (error);
    
    	case PRU_ABORT:
    		soisdisconnected(so);
    		in_pcbdetach(inp);
    		break;
    
    	case PRU_SOCKADDR:
    #ifdef INET6
    		if (inp->inp_flags & INP_IPV6)
    			in6_setsockaddr(inp, addr);
    		else
    #endif /* INET6 */
    			in_setsockaddr(inp, addr);
    		break;
    
    	case PRU_PEERADDR:
    #ifdef INET6
    		if (inp->inp_flags & INP_IPV6)
    			in6_setpeeraddr(inp, addr);
    		else
    #endif /* INET6 */
    			in_setpeeraddr(inp, addr);
    		break;
    
    	case PRU_SENSE:
    		/*
    		 * stat: don't bother with a blocksize.
    		 */
    		/*
    		 * Perhaps Path MTU might be returned for a connected
    		 * UDP socket in this case.
    		 */
    		break;
    
    	case PRU_SENDOOB:
    	case PRU_FASTTIMO:
    	case PRU_SLOWTIMO:
    	case PRU_PROTORCV:
    	case PRU_PROTOSEND:
    	case PRU_RCVD:
    	case PRU_RCVOOB:
    		error =  EOPNOTSUPP;
    		break;
    
    	default:
    		panic("udp_usrreq");
    	}
    release:
    	if (req != PRU_RCVD && req != PRU_RCVOOB && req != PRU_SENSE) {
    		m_freem(control);
    		m_freem(m);
    	}
    	return (error);
    }
    
    int
    udp_attach(struct socket *so, int proto)
    {
    	int error;
    
    	if (so->so_pcb != NULL)
    		return EINVAL;
    
    	if ((error = soreserve(so, udp_sendspace, udp_recvspace)))
    		return error;
    
    	NET_ASSERT_LOCKED();
    	if ((error = in_pcballoc(so, &udbtable)))
    		return error;
    #ifdef INET6
    	if (sotoinpcb(so)->inp_flags & INP_IPV6)
    		sotoinpcb(so)->inp_ipv6.ip6_hlim = ip6_defhlim;
    	else
    #endif /* INET6 */
    		sotoinpcb(so)->inp_ip.ip_ttl = ip_defttl;
    	return 0;
    }
    
    int
    udp_detach(struct socket *so)
    {
    	struct inpcb *inp;
    
    	soassertlocked(so);
    
    	inp = sotoinpcb(so);
    	if (inp == NULL)
    		return (EINVAL);
    
    	in_pcbdetach(inp);
    	return (0);
    }
    
    /*
     * Sysctl for udp variables.
     */
    int
    udp_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
        size_t newlen)
    {
    	int error;
    
    	/* All sysctl names at this level are terminal. */
    	if (namelen != 1)
    		return (ENOTDIR);
    
    	switch (name[0]) {
    	case UDPCTL_BADDYNAMIC:
    		NET_LOCK();
    		error = sysctl_struct(oldp, oldlenp, newp, newlen,
    		    baddynamicports.udp, sizeof(baddynamicports.udp));
    		NET_UNLOCK();
    		return (error);
    
    	case UDPCTL_ROOTONLY:
    		if (newp && securelevel > 0)
    			return (EPERM);
    		NET_LOCK();
    		error = sysctl_struct(oldp, oldlenp, newp, newlen,
    		    rootonlyports.udp, sizeof(rootonlyports.udp));
    		NET_UNLOCK();
    		return (error);
    
    	case UDPCTL_STATS:
    		if (newp != NULL)
    			return (EPERM);
    
    		return (udp_sysctl_udpstat(oldp, oldlenp, newp));
    
    	default:
    		NET_LOCK();
    		error = sysctl_bounded_arr(udpctl_vars, nitems(udpctl_vars),
    		    name, namelen, oldp, oldlenp, newp, newlen);
    		NET_UNLOCK();
    		return (error);
    	}
    	/* NOTREACHED */
    }
    
    int
    udp_sysctl_udpstat(void *oldp, size_t *oldlenp, void *newp)
    {
    	uint64_t counters[udps_ncounters];
    	struct udpstat udpstat;
    	u_long *words = (u_long *)&udpstat;
    	int i;
    
    	CTASSERT(sizeof(udpstat) == (nitems(counters) * sizeof(u_long)));
    	memset(&udpstat, 0, sizeof udpstat);
    	counters_read(udpcounters, counters, nitems(counters));
    
    	for (i = 0; i < nitems(counters); i++)
    		words[i] = (u_long)counters[i];
    
    	return (sysctl_rdstruct(oldp, oldlenp, newp,
    	    &udpstat, sizeof(udpstat)));
    }