new file mode 100644
--- /dev/null
+++ b/packages/net/tcpip/current/src/sys/netinet/ip_input.c
@@ -0,0 +1,1565 @@
+//==========================================================================
+//
+//      sys/netinet/ip_input.c
+//
+//     
+//
+//==========================================================================
+//####COPYRIGHTBEGIN####
+//                                                                          
+// -------------------------------------------                              
+// The contents of this file are subject to the Red Hat eCos Public License 
+// Version 1.1 (the "License"); you may not use this file except in         
+// compliance with the License.  You may obtain a copy of the License at    
+// http://www.redhat.com/                                                   
+//                                                                          
+// Software distributed under the License is distributed on an "AS IS"      
+// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the 
+// License for the specific language governing rights and limitations under 
+// the License.                                                             
+//                                                                          
+// The Original Code is eCos - Embedded Configurable Operating System,      
+// released September 30, 1998.                                             
+//                                                                          
+// The Initial Developer of the Original Code is Red Hat.                   
+// Portions created by Red Hat are                                          
+// Copyright (C) 1998, 1999, 2000 Red Hat, Inc.                             
+// All Rights Reserved.                                                     
+// -------------------------------------------                              
+//                                                                          
+//####COPYRIGHTEND####
+//####BSDCOPYRIGHTBEGIN####
+//
+// -------------------------------------------
+//
+// Portions of this software may have been derived from OpenBSD or other sources,
+// and are covered by the appropriate copyright disclaimers included herein.
+//
+// -------------------------------------------
+//
+//####BSDCOPYRIGHTEND####
+//==========================================================================
+//#####DESCRIPTIONBEGIN####
+//
+// Author(s):    gthomas
+// Contributors: gthomas
+// Date:         2000-01-10
+// Purpose:      
+// Description:  
+//              
+//
+//####DESCRIPTIONEND####
+//
+//==========================================================================
+
+
+/*	$OpenBSD: ip_input.c,v 1.44 1999/12/08 06:50:20 itojun Exp $	*/
+/*	$NetBSD: ip_input.c,v 1.30 1996/03/16 23:53:58 christos Exp $	*/
+
+/*
+ * Copyright (c) 1982, 1986, 1988, 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.
+ *
+ *	@(#)ip_input.c	8.2 (Berkeley) 1/4/94
+ */
+
+#include <sys/param.h>
+#ifndef __ECOS
+#include <sys/systm.h>
+#endif
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/domain.h>
+#include <sys/protosw.h>
+#include <sys/socket.h>
+#include <sys/errno.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+#ifndef __ECOS
+#include <sys/syslog.h>
+#include <sys/proc.h>
+
+#include <vm/vm.h>
+#include <sys/sysctl.h>
+#endif
+
+#include <net/if.h>
+#include <net/if_dl.h>
+#include <net/route.h>
+
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#include <netinet/if_ether.h>
+#include <netinet/ip.h>
+#include <netinet/in_pcb.h>
+#include <netinet/in_var.h>
+#include <netinet/ip_var.h>
+#include <netinet/ip_icmp.h>
+#include <netinet/ip_ipsp.h>
+
+#ifdef __ECOS
+#include <stdio.h>    // for 'sprintf()'
+#endif
+
+#ifndef	IPFORWARDING
+#ifdef GATEWAY
+#define	IPFORWARDING	1	/* forward IP packets not for us */
+#else /* GATEWAY */
+#define	IPFORWARDING	0	/* don't forward IP packets not for us */
+#endif /* GATEWAY */
+#endif /* IPFORWARDING */
+#ifndef	IPSENDREDIRECTS
+#define	IPSENDREDIRECTS	1
+#endif
+
+int encdebug = 0;
+
+/*
+ * Note: DIRECTED_BROADCAST is handled this way so that previous
+ * configuration using this option will Just Work.
+ */
+#ifndef IPDIRECTEDBCAST
+#ifdef DIRECTED_BROADCAST
+#define IPDIRECTEDBCAST	1
+#else
+#define	IPDIRECTEDBCAST	0
+#endif /* DIRECTED_BROADCAST */
+#endif /* IPDIRECTEDBCAST */
+int	ipforwarding = IPFORWARDING;
+int	ipsendredirects = IPSENDREDIRECTS;
+int	ip_dosourceroute = 0;	/* no src-routing unless sysctl'd to enable */
+int	ip_defttl = IPDEFTTL;
+int	ip_directedbcast = IPDIRECTEDBCAST;
+#ifdef DIAGNOSTIC
+int	ipprintfs = 0;
+#endif
+
+int	ipsec_auth_default_level = IPSEC_AUTH_LEVEL_DEFAULT;
+int	ipsec_esp_trans_default_level = IPSEC_ESP_TRANS_LEVEL_DEFAULT;
+int	ipsec_esp_network_default_level = IPSEC_ESP_NETWORK_LEVEL_DEFAULT;
+
+/* Keep track of memory used for reassembly */
+int	ip_maxqueue = 300;
+int	ip_frags = 0;
+
+/* from in_pcb.c */
+extern int ipport_firstauto;
+extern int ipport_lastauto;
+extern int ipport_hifirstauto;
+extern int ipport_hilastauto;
+extern struct baddynamicports baddynamicports;
+
+extern	struct domain inetdomain;
+extern	struct protosw inetsw[];
+u_char	ip_protox[IPPROTO_MAX];
+int	ipqmaxlen = IFQ_MAXLEN;
+struct	in_ifaddrhead in_ifaddr;
+struct	ifqueue ipintrq;
+#if defined(IPFILTER) || defined(IPFILTER_LKM)
+int	(*fr_checkp) __P((struct ip *, int, struct ifnet *, int,
+			  struct mbuf **));
+#endif
+
+int	ipq_locked;
+static __inline int ipq_lock_try __P((void));
+static __inline void ipq_unlock __P((void));
+
+static __inline int
+ipq_lock_try()
+{
+	int s;
+
+	s = splimp();
+	if (ipq_locked) {
+		splx(s);
+		return (0);
+	}
+	ipq_locked = 1;
+	splx(s);
+	return (1);
+}
+
+#define ipq_lock() ipq_lock_try()
+
+static __inline void
+ipq_unlock()
+{
+	int s;
+
+	s = splimp();
+	ipq_locked = 0;
+	splx(s);
+}
+
+char *
+inet_ntoa(ina)
+	struct in_addr ina;
+{
+	static char buf[4*sizeof "123"];
+	unsigned char *ucp = (unsigned char *)&ina;
+
+	sprintf(buf, "%d.%d.%d.%d", ucp[0] & 0xff, ucp[1] & 0xff,
+	    ucp[2] & 0xff, ucp[3] & 0xff);
+	return (buf);
+}
+
+/*
+ * We need to save the IP options in case a protocol wants to respond
+ * to an incoming packet over the same route if the packet got here
+ * using IP source routing.  This allows connection establishment and
+ * maintenance when the remote end is on a network that is not known
+ * to us.
+ */
+int	ip_nhops = 0;
+static	struct ip_srcrt {
+	struct	in_addr dst;			/* final destination */
+	char	nop;				/* one NOP to align */
+	char	srcopt[IPOPT_OFFSET + 1];	/* OPTVAL, OLEN and OFFSET */
+	struct	in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
+} ip_srcrt;
+
+static void save_rte __P((u_char *, struct in_addr));
+static int ip_weadvertise(u_int32_t);
+
+/*
+ * IP initialization: fill in IP protocol switch table.
+ * All protocols not implemented in kernel go to raw IP protocol handler.
+ */
+void
+ip_init()
+{
+	register struct protosw *pr;
+	register int i;
+	const u_int16_t defbaddynamicports_tcp[] = DEFBADDYNAMICPORTS_TCP;
+	const u_int16_t defbaddynamicports_udp[] = DEFBADDYNAMICPORTS_UDP;
+
+	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
+	if (pr == 0)
+		panic("ip_init");
+	for (i = 0; i < IPPROTO_MAX; i++)
+		ip_protox[i] = pr - inetsw;
+	for (pr = inetdomain.dom_protosw;
+	    pr < inetdomain.dom_protoswNPROTOSW; pr++)
+		if (pr->pr_domain->dom_family == PF_INET &&
+		    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
+			ip_protox[pr->pr_protocol] = pr - inetsw;
+	LIST_INIT(&ipq);
+	ipintrq.ifq_maxlen = ipqmaxlen;
+	TAILQ_INIT(&in_ifaddr);
+
+	/* Fill in list of ports not to allocate dynamically. */
+	bzero((void *)&baddynamicports, sizeof(baddynamicports));
+	for (i = 0; defbaddynamicports_tcp[i] != 0; i++)
+		DP_SET(baddynamicports.tcp, defbaddynamicports_tcp[i]);
+	for (i = 0; defbaddynamicports_udp[i] != 0; i++)
+		DP_SET(baddynamicports.udp, defbaddynamicports_tcp[i]);
+}
+
+struct	sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
+struct	route ipforward_rt;
+
+void
+ipintr()
+{
+	register struct mbuf *m;
+	int s;
+
+	if (needqueuedrain)
+		m_reclaim();
+	
+	while (1) {
+		/*
+		 * Get next datagram off input queue and get IP header
+		 * in first mbuf.
+		 */
+		s = splimp();
+		IF_DEQUEUE(&ipintrq, m);
+		splx(s);
+		if (m == 0)
+			return;
+#ifdef	DIAGNOSTIC
+		if ((m->m_flags & M_PKTHDR) == 0)
+			panic("ipintr no HDR");
+#endif
+		ipv4_input(m, 0, NULL, 0);
+	}
+}
+
+/*
+ * Ip input routine.  Checksum and byte swap header.  If fragmented
+ * try to reassemble.  Process options.  Pass to next level.
+ */
+void
+ipv4_input(struct mbuf *m, ...)
+{
+	register struct ip *ip;
+	register struct ipq *fp;
+	struct in_ifaddr *ia;
+	struct ipqent *ipqe;
+	int hlen, mff;
+	va_list ap;
+	int extra;
+
+	va_start(ap, m);
+	extra = va_arg(ap, int);
+	va_end(ap);
+
+	if (extra) {
+		struct mbuf *newpacket;
+
+		if (!(newpacket = m_split(m, extra, M_NOWAIT))) {
+			m_freem(m);
+			return;
+		}
+
+		newpacket->m_flags |= m->m_flags;
+		m_freem(m);
+		m = newpacket;
+		extra = 0;
+	}
+
+	/*
+	 * If no IP addresses have been set yet but the interfaces
+	 * are receiving, can't do anything with incoming packets yet.
+	 */
+	if (in_ifaddr.tqh_first == 0)
+		goto bad;
+	ipstat.ips_total++;
+	if (m->m_len < sizeof (struct ip) &&
+	    (m = m_pullup(m, sizeof (struct ip))) == 0) {
+		ipstat.ips_toosmall++;
+		return;
+	}
+	ip = mtod(m, struct ip *);
+	if (ip->ip_v != IPVERSION) {
+		ipstat.ips_badvers++;
+		goto bad;
+	}
+	hlen = ip->ip_hl << 2;
+	if (hlen < sizeof(struct ip)) {	/* minimum header length */
+		ipstat.ips_badhlen++;
+		goto bad;
+	}
+	if (hlen > m->m_len) {
+		if ((m = m_pullup(m, hlen)) == 0) {
+			ipstat.ips_badhlen++;
+			return;
+		}
+		ip = mtod(m, struct ip *);
+	}
+	if ((ip->ip_sum = in_cksum(m, hlen)) != 0) {
+		ipstat.ips_badsum++;
+		goto bad;
+	}
+
+	/*
+	 * Convert fields to host representation.
+	 */
+	NTOHS(ip->ip_len);
+	if (ip->ip_len < hlen) {
+		ipstat.ips_badlen++;
+		goto bad;
+	}
+	NTOHS(ip->ip_id);
+	NTOHS(ip->ip_off);
+
+	/*
+	 * Check that the amount of data in the buffers
+	 * is as at least much as the IP header would have us expect.
+	 * Trim mbufs if longer than we expect.
+	 * Drop packet if shorter than we expect.
+	 */
+	if (m->m_pkthdr.len < ip->ip_len) {
+		ipstat.ips_tooshort++;
+		goto bad;
+	}
+	if (m->m_pkthdr.len > ip->ip_len) {
+		if (m->m_len == m->m_pkthdr.len) {
+			m->m_len = ip->ip_len;
+			m->m_pkthdr.len = ip->ip_len;
+		} else
+			m_adj(m, ip->ip_len - m->m_pkthdr.len);
+	}
+
+#if defined(IPFILTER) || defined(IPFILTER_LKM)
+	 /*
+	 * Check if we want to allow this packet to be processed.
+	 * Consider it to be bad if not.
+	 */
+	{
+		struct mbuf *m0 = m;
+		if (fr_checkp && (*fr_checkp)(ip, hlen, m->m_pkthdr.rcvif, 0, &m0))
+			return;
+		ip = mtod(m = m0, struct ip *);
+	}
+#endif
+
+	/*
+	 * Process options and, if not destined for us,
+	 * ship it on.  ip_dooptions returns 1 when an
+	 * error was detected (causing an icmp message
+	 * to be sent and the original packet to be freed).
+	 */
+	ip_nhops = 0;		/* for source routed packets */
+	if (hlen > sizeof (struct ip) && ip_dooptions(m))
+		return;
+
+	/*
+	 * Check our list of addresses, to see if the packet is for us.
+	 */
+	if ((ia = in_iawithaddr(ip->ip_dst, m)) != NULL &&
+	    (ia->ia_ifp->if_flags & IFF_UP))
+		goto ours;
+
+	if (IN_MULTICAST(ip->ip_dst.s_addr)) {
+		struct in_multi *inm;
+#ifdef MROUTING
+		extern struct socket *ip_mrouter;
+
+		if (m->m_flags & M_EXT) {
+			if ((m = m_pullup(m, hlen)) == 0) {
+				ipstat.ips_toosmall++;
+				return;
+			}
+			ip = mtod(m, struct ip *);
+		}
+
+		if (ip_mrouter) {
+			/*
+			 * If we are acting as a multicast router, all
+			 * incoming multicast packets are passed to the
+			 * kernel-level multicast forwarding function.
+			 * The packet is returned (relatively) intact; if
+			 * ip_mforward() returns a non-zero value, the packet
+			 * must be discarded, else it may be accepted below.
+			 *
+			 * (The IP ident field is put in the same byte order
+			 * as expected when ip_mforward() is called from
+			 * ip_output().)
+			 */
+			ip->ip_id = htons(ip->ip_id);
+			if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
+				ipstat.ips_cantforward++;
+				m_freem(m);
+				return;
+			}
+			ip->ip_id = ntohs(ip->ip_id);
+
+			/*
+			 * The process-level routing demon needs to receive
+			 * all multicast IGMP packets, whether or not this
+			 * host belongs to their destination groups.
+			 */
+			if (ip->ip_p == IPPROTO_IGMP)
+				goto ours;
+			ipstat.ips_forward++;
+		}
+#endif
+		/*
+		 * See if we belong to the destination multicast group on the
+		 * arrival interface.
+		 */
+		IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
+		if (inm == NULL) {
+			ipstat.ips_cantforward++;
+			m_freem(m);
+			return;
+		}
+		goto ours;
+	}
+	if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
+	    ip->ip_dst.s_addr == INADDR_ANY)
+		goto ours;
+
+	/*
+	 * Not for us; forward if possible and desirable.
+	 */
+	if (ipforwarding == 0) {
+		ipstat.ips_cantforward++;
+		m_freem(m);
+	} else
+		ip_forward(m, 0);
+	return;
+
+ours:
+	/*
+	 * If offset or IP_MF are set, must reassemble.
+	 * Otherwise, nothing need be done.
+	 * (We could look in the reassembly queue to see
+	 * if the packet was previously fragmented,
+	 * but it's not worth the time; just let them time out.)
+	 */
+	if (ip->ip_off &~ (IP_DF | IP_RF)) {
+		if (m->m_flags & M_EXT) {		/* XXX */
+			if ((m = m_pullup(m, hlen)) == 0) {
+				ipstat.ips_toosmall++;
+				return;
+			}
+			ip = mtod(m, struct ip *);
+		}
+
+		/*
+		 * Look for queue of fragments
+		 * of this datagram.
+		 */
+		ipq_lock();
+		for (fp = ipq.lh_first; fp != NULL; fp = fp->ipq_q.le_next)
+			if (ip->ip_id == fp->ipq_id &&
+			    ip->ip_src.s_addr == fp->ipq_src.s_addr &&
+			    ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
+			    ip->ip_p == fp->ipq_p)
+				goto found;
+		fp = 0;
+found:
+
+		/*
+		 * Adjust ip_len to not reflect header,
+		 * set ipqe_mff if more fragments are expected,
+		 * convert offset of this to bytes.
+		 */
+		ip->ip_len -= hlen;
+		mff = (ip->ip_off & IP_MF) != 0;
+		if (mff) {
+			/*
+			 * Make sure that fragments have a data length
+			 * that's a non-zero multiple of 8 bytes.
+			 */
+			if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
+				ipstat.ips_badfrags++;
+				ipq_unlock();
+				goto bad;
+			}
+		}
+		ip->ip_off <<= 3;
+
+		/*
+		 * If datagram marked as having more fragments
+		 * or if this is not the first fragment,
+		 * attempt reassembly; if it succeeds, proceed.
+		 */
+		if (mff || ip->ip_off) {
+			ipstat.ips_fragments++;
+			if (ip_frags + 1 > ip_maxqueue) {
+				ip_flush();
+				ipstat.ips_rcvmemdrop++;
+				ipq_unlock();
+				goto bad;
+			}
+			    
+			MALLOC(ipqe, struct ipqent *, sizeof (struct ipqent),
+			    M_IPQ, M_NOWAIT);
+			if (ipqe == NULL) {
+				ipstat.ips_rcvmemdrop++;
+				ipq_unlock();
+				goto bad;
+			}
+			ip_frags++;
+			ipqe->ipqe_mff = mff;
+			ipqe->ipqe_ip = ip;
+			ip = ip_reass(ipqe, fp);
+			if (ip == 0) {
+				ipq_unlock();
+				return;
+			}
+			ipstat.ips_reassembled++;
+			m = dtom(ip);
+			hlen = ip->ip_hl << 2;
+		} else
+			if (fp)
+				ip_freef(fp);
+		ipq_unlock();
+	} else
+		ip->ip_len -= hlen;
+
+	/*
+	 * Switch out to protocol's input routine.
+	 */
+	ipstat.ips_delivered++;
+	(*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen, NULL, 0);
+	return;
+bad:
+	m_freem(m);
+}
+
+struct in_ifaddr *
+in_iawithaddr(ina, m)
+	struct in_addr ina;
+	register struct mbuf *m;
+{
+	register struct in_ifaddr *ia;
+
+	for (ia = in_ifaddr.tqh_first; ia; ia = ia->ia_list.tqe_next) {
+		if ((ina.s_addr == ia->ia_addr.sin_addr.s_addr) ||
+		    ((ia->ia_ifp->if_flags & (IFF_LOOPBACK|IFF_LINK1)) ==
+			(IFF_LOOPBACK|IFF_LINK1) &&
+		     ia->ia_subnet == (ina.s_addr & ia->ia_subnetmask)))
+			return ia;
+		if (m && ((ip_directedbcast == 0) || (ip_directedbcast &&
+		    ia->ia_ifp == m->m_pkthdr.rcvif)) &&
+		    (ia->ia_ifp->if_flags & IFF_BROADCAST)) {
+			if (ina.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
+			    ina.s_addr == ia->ia_netbroadcast.s_addr ||
+			    /*
+			     * Look for all-0's host part (old broadcast addr),
+			     * either for subnet or net.
+			     */
+			    ina.s_addr == ia->ia_subnet ||
+			    ina.s_addr == ia->ia_net) {
+				/* Make sure M_BCAST is set */
+				m->m_flags |= M_BCAST;
+				return ia;
+			    }
+		}
+	}
+
+	return NULL;
+}
+
+/*
+ * Take incoming datagram fragment and try to
+ * reassemble it into whole datagram.  If a chain for
+ * reassembly of this datagram already exists, then it
+ * is given as fp; otherwise have to make a chain.
+ */
+struct ip *
+ip_reass(ipqe, fp)
+	register struct ipqent *ipqe;
+	register struct ipq *fp;
+{
+	register struct mbuf *m = dtom(ipqe->ipqe_ip);
+	register struct ipqent *nq, *p, *q;
+	struct ip *ip;
+	struct mbuf *t;
+	int hlen = ipqe->ipqe_ip->ip_hl << 2;
+	int i, next;
+
+	/*
+	 * Presence of header sizes in mbufs
+	 * would confuse code below.
+	 */
+	m->m_data += hlen;
+	m->m_len -= hlen;
+
+	/*
+	 * If first fragment to arrive, create a reassembly queue.
+	 */
+	if (fp == 0) {
+		if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL)
+			goto dropfrag;
+		fp = mtod(t, struct ipq *);
+		LIST_INSERT_HEAD(&ipq, fp, ipq_q);
+		fp->ipq_ttl = IPFRAGTTL;
+		fp->ipq_p = ipqe->ipqe_ip->ip_p;
+		fp->ipq_id = ipqe->ipqe_ip->ip_id;
+		LIST_INIT(&fp->ipq_fragq);
+		fp->ipq_src = ipqe->ipqe_ip->ip_src;
+		fp->ipq_dst = ipqe->ipqe_ip->ip_dst;
+		p = NULL;
+		goto insert;
+	}
+
+	/*
+	 * Find a segment which begins after this one does.
+	 */
+	for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
+	    p = q, q = q->ipqe_q.le_next)
+		if (q->ipqe_ip->ip_off > ipqe->ipqe_ip->ip_off)
+			break;
+
+	/*
+	 * If there is a preceding segment, it may provide some of
+	 * our data already.  If so, drop the data from the incoming
+	 * segment.  If it provides all of our data, drop us.
+	 */
+	if (p != NULL) {
+		i = p->ipqe_ip->ip_off + p->ipqe_ip->ip_len -
+		    ipqe->ipqe_ip->ip_off;
+		if (i > 0) {
+			if (i >= ipqe->ipqe_ip->ip_len)
+				goto dropfrag;
+			m_adj(dtom(ipqe->ipqe_ip), i);
+			ipqe->ipqe_ip->ip_off += i;
+			ipqe->ipqe_ip->ip_len -= i;
+		}
+	}
+
+	/*
+	 * While we overlap succeeding segments trim them or,
+	 * if they are completely covered, dequeue them.
+	 */
+	for (; q != NULL && ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len >
+	    q->ipqe_ip->ip_off; q = nq) {
+		i = (ipqe->ipqe_ip->ip_off + ipqe->ipqe_ip->ip_len) -
+		    q->ipqe_ip->ip_off;
+		if (i < q->ipqe_ip->ip_len) {
+			q->ipqe_ip->ip_len -= i;
+			q->ipqe_ip->ip_off += i;
+			m_adj(dtom(q->ipqe_ip), i);
+			break;
+		}
+		nq = q->ipqe_q.le_next;
+		m_freem(dtom(q->ipqe_ip));
+		LIST_REMOVE(q, ipqe_q);
+		FREE(q, M_IPQ);
+		ip_frags--;
+	}
+
+insert:
+	/*
+	 * Stick new segment in its place;
+	 * check for complete reassembly.
+	 */
+	if (p == NULL) {
+		LIST_INSERT_HEAD(&fp->ipq_fragq, ipqe, ipqe_q);
+	} else {
+		LIST_INSERT_AFTER(p, ipqe, ipqe_q);
+	}
+	next = 0;
+	for (p = NULL, q = fp->ipq_fragq.lh_first; q != NULL;
+	    p = q, q = q->ipqe_q.le_next) {
+		if (q->ipqe_ip->ip_off != next)
+			return (0);
+		next += q->ipqe_ip->ip_len;
+	}
+	if (p->ipqe_mff)
+		return (0);
+
+	/*
+	 * Reassembly is complete.  Check for a bogus message size and
+	 * concatenate fragments.
+	 */
+	q = fp->ipq_fragq.lh_first;
+	ip = q->ipqe_ip;
+	if ((next + (ip->ip_hl << 2)) > IP_MAXPACKET) {
+		ipstat.ips_toolong++;
+		ip_freef(fp);
+		return (0);
+	}
+	m = dtom(q->ipqe_ip);
+	t = m->m_next;
+	m->m_next = 0;
+	m_cat(m, t);
+	nq = q->ipqe_q.le_next;
+	FREE(q, M_IPQ);
+	ip_frags--;
+	for (q = nq; q != NULL; q = nq) {
+		t = dtom(q->ipqe_ip);
+		nq = q->ipqe_q.le_next;
+		FREE(q, M_IPQ);
+		ip_frags--;
+		m_cat(m, t);
+	}
+
+	/*
+	 * Create header for new ip packet by
+	 * modifying header of first packet;
+	 * dequeue and discard fragment reassembly header.
+	 * Make header visible.
+	 */
+	ip->ip_len = next;
+	ip->ip_ttl = 0;	/* xxx */
+	ip->ip_sum = 0;
+	ip->ip_src = fp->ipq_src;
+	ip->ip_dst = fp->ipq_dst;
+	LIST_REMOVE(fp, ipq_q);
+	(void) m_free(dtom(fp));
+	m->m_len += (ip->ip_hl << 2);
+	m->m_data -= (ip->ip_hl << 2);
+	/* some debugging cruft by sklower, below, will go away soon */
+	if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
+		register int plen = 0;
+		for (t = m; m; m = m->m_next)
+			plen += m->m_len;
+		t->m_pkthdr.len = plen;
+	}
+	return (ip);
+
+dropfrag:
+	ipstat.ips_fragdropped++;
+	m_freem(m);
+	FREE(ipqe, M_IPQ);
+	ip_frags--;
+	return (0);
+}
+
+/*
+ * Free a fragment reassembly header and all
+ * associated datagrams.
+ */
+void
+ip_freef(fp)
+	struct ipq *fp;
+{
+	register struct ipqent *q, *p;
+
+	for (q = fp->ipq_fragq.lh_first; q != NULL; q = p) {
+		p = q->ipqe_q.le_next;
+		m_freem(dtom(q->ipqe_ip));
+		LIST_REMOVE(q, ipqe_q);
+		FREE(q, M_IPQ);
+		ip_frags--;
+	}
+	LIST_REMOVE(fp, ipq_q);
+	(void) m_free(dtom(fp));
+}
+
+/*
+ * IP timer processing;
+ * if a timer expires on a reassembly
+ * queue, discard it.
+ */
+void
+ip_slowtimo()
+{
+	register struct ipq *fp, *nfp;
+	int s = splsoftnet();
+
+	ipq_lock();
+	for (fp = ipq.lh_first; fp != NULL; fp = nfp) {
+		nfp = fp->ipq_q.le_next;
+		if (--fp->ipq_ttl == 0) {
+			ipstat.ips_fragtimeout++;
+			ip_freef(fp);
+		}
+	}
+	ipq_unlock();
+	splx(s);
+}
+
+/*
+ * Drain off all datagram fragments.
+ */
+void
+ip_drain()
+{
+
+	if (ipq_lock_try() == 0)
+		return;
+	while (ipq.lh_first != NULL) {
+		ipstat.ips_fragdropped++;
+		ip_freef(ipq.lh_first);
+	}
+	ipq_unlock();
+}
+
+/*
+ * Flush a bunch of datagram fragments, till we are down to 75%.
+ */
+void
+ip_flush()
+{
+	int max = 50;
+
+	/* ipq already locked */
+	while (ipq.lh_first != NULL && ip_frags > ip_maxqueue * 3 / 4 && --max) {
+		ipstat.ips_fragdropped++;
+		ip_freef(ipq.lh_first);
+	}
+}
+
+/*
+ * Do option processing on a datagram,
+ * possibly discarding it if bad options are encountered,
+ * or forwarding it if source-routed.
+ * Returns 1 if packet has been forwarded/freed,
+ * 0 if the packet should be processed further.
+ */
+int
+ip_dooptions(m)
+	struct mbuf *m;
+{
+	register struct ip *ip = mtod(m, struct ip *);
+	register u_char *cp;
+	register struct ip_timestamp *ipt;
+	register struct in_ifaddr *ia;
+	int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
+	struct in_addr *sin, dst;
+	n_time ntime;
+
+	dst = ip->ip_dst;
+	cp = (u_char *)(ip + 1);
+	cnt = (ip->ip_hl << 2) - sizeof (struct ip);
+	for (; cnt > 0; cnt -= optlen, cp += optlen) {
+		opt = cp[IPOPT_OPTVAL];
+		if (opt == IPOPT_EOL)
+			break;
+		if (opt == IPOPT_NOP)
+			optlen = 1;
+		else {
+			optlen = cp[IPOPT_OLEN];
+			if (optlen <= 0 || optlen > cnt) {
+				code = &cp[IPOPT_OLEN] - (u_char *)ip;
+				goto bad;
+			}
+		}
+		switch (opt) {
+
+		default:
+			break;
+
+		/*
+		 * Source routing with record.
+		 * Find interface with current destination address.
+		 * If none on this machine then drop if strictly routed,
+		 * or do nothing if loosely routed.
+		 * Record interface address and bring up next address
+		 * component.  If strictly routed make sure next
+		 * address is on directly accessible net.
+		 */
+		case IPOPT_LSRR:
+		case IPOPT_SSRR:
+			if (!ip_dosourceroute) {
+#ifndef __ECOS
+				char buf[4*sizeof "123"];
+
+				strcpy(buf, inet_ntoa(ip->ip_dst));
+				log(LOG_WARNING,
+				    "attempted source route from %s to %s\n",
+				    inet_ntoa(ip->ip_src), buf);
+#endif
+				type = ICMP_UNREACH;
+				code = ICMP_UNREACH_SRCFAIL;
+				goto bad;
+			}
+			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
+				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
+				goto bad;
+			}
+			ipaddr.sin_addr = ip->ip_dst;
+			ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
+			if (ia == 0) {
+				if (opt == IPOPT_SSRR) {
+					type = ICMP_UNREACH;
+					code = ICMP_UNREACH_SRCFAIL;
+					goto bad;
+				}
+				/*
+				 * Loose routing, and not at next destination
+				 * yet; nothing to do except forward.
+				 */
+				break;
+			}
+			off--;			/* 0 origin */
+			if (off > optlen - sizeof(struct in_addr)) {
+				/*
+				 * End of source route.  Should be for us.
+				 */
+				save_rte(cp, ip->ip_src);
+				break;
+			}
+
+			/*
+			 * locate outgoing interface
+			 */
+			bcopy((caddr_t)(cp + off), (caddr_t)&ipaddr.sin_addr,
+			    sizeof(ipaddr.sin_addr));
+			if (opt == IPOPT_SSRR) {
+#define	INA	struct in_ifaddr *
+#define	SA	struct sockaddr *
+			    if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
+				ia = (INA)ifa_ifwithnet((SA)&ipaddr);
+			} else
+				ia = ip_rtaddr(ipaddr.sin_addr);
+			if (ia == 0) {
+				type = ICMP_UNREACH;
+				code = ICMP_UNREACH_SRCFAIL;
+				goto bad;
+			}
+			ip->ip_dst = ipaddr.sin_addr;
+			bcopy((caddr_t)&ia->ia_addr.sin_addr,
+			    (caddr_t)(cp + off), sizeof(struct in_addr));
+			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
+			/*
+			 * Let ip_intr's mcast routing check handle mcast pkts
+			 */
+			forward = !IN_MULTICAST(ip->ip_dst.s_addr);
+			break;
+
+		case IPOPT_RR:
+			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
+				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
+				goto bad;
+			}
+
+			/*
+			 * If no space remains, ignore.
+			 */
+			off--;			/* 0 origin */
+			if (off > optlen - sizeof(struct in_addr))
+				break;
+			bcopy((caddr_t)(&ip->ip_dst), (caddr_t)&ipaddr.sin_addr,
+			    sizeof(ipaddr.sin_addr));
+			/*
+			 * locate outgoing interface; if we're the destination,
+			 * use the incoming interface (should be same).
+			 */
+			if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
+			    (ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
+				type = ICMP_UNREACH;
+				code = ICMP_UNREACH_HOST;
+				goto bad;
+			}
+			bcopy((caddr_t)&ia->ia_addr.sin_addr,
+			    (caddr_t)(cp + off), sizeof(struct in_addr));
+			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
+			break;
+
+		case IPOPT_TS:
+			code = cp - (u_char *)ip;
+			ipt = (struct ip_timestamp *)cp;
+			if (ipt->ipt_ptr < 5 || ipt->ipt_len < 5)
+				goto bad;
+			if (ipt->ipt_ptr - 1 + sizeof(n_time) > ipt->ipt_len) {
+				if (++ipt->ipt_oflw == 0)
+					goto bad;
+				break;
+			}
+			sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
+			switch (ipt->ipt_flg) {
+
+			case IPOPT_TS_TSONLY:
+				break;
+
+			case IPOPT_TS_TSANDADDR:
+				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
+				    sizeof(struct in_addr) > ipt->ipt_len)
+					goto bad;
+				ipaddr.sin_addr = dst;
+				ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
+							    m->m_pkthdr.rcvif);
+				if (ia == 0)
+					continue;
+				bcopy((caddr_t)&ia->ia_addr.sin_addr,
+				    (caddr_t)sin, sizeof(struct in_addr));
+				ipt->ipt_ptr += sizeof(struct in_addr);
+				break;
+
+			case IPOPT_TS_PRESPEC:
+				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
+				    sizeof(struct in_addr) > ipt->ipt_len)
+					goto bad;
+				bcopy((caddr_t)sin, (caddr_t)&ipaddr.sin_addr,
+				    sizeof(struct in_addr));
+				if (ifa_ifwithaddr((SA)&ipaddr) == 0)
+					continue;
+				ipt->ipt_ptr += sizeof(struct in_addr);
+				break;
+
+			default:
+				goto bad;
+			}
+			ntime = iptime();
+			bcopy((caddr_t)&ntime, (caddr_t)cp + ipt->ipt_ptr - 1,
+			    sizeof(n_time));
+			ipt->ipt_ptr += sizeof(n_time);
+		}
+	}
+	if (forward && ipforwarding) {
+		ip_forward(m, 1);
+		return (1);
+	}
+	return (0);
+bad:
+	ip->ip_len -= ip->ip_hl << 2;   /* XXX icmp_error adds in hdr length */
+	HTONS(ip->ip_len);	/* XXX because ip_input changed these three */
+	HTONS(ip->ip_id);
+	HTONS(ip->ip_off);
+	icmp_error(m, type, code, 0, 0);
+	ipstat.ips_badoptions++;
+	return (1);
+}
+
+/*
+ * Given address of next destination (final or next hop),
+ * return internet address info of interface to be used to get there.
+ */
+struct in_ifaddr *
+ip_rtaddr(dst)
+	 struct in_addr dst;
+{
+	register struct sockaddr_in *sin;
+
+	sin = satosin(&ipforward_rt.ro_dst);
+
+	if (ipforward_rt.ro_rt == 0 || dst.s_addr != sin->sin_addr.s_addr) {
+		if (ipforward_rt.ro_rt) {
+			RTFREE(ipforward_rt.ro_rt);
+			ipforward_rt.ro_rt = 0;
+		}
+		sin->sin_family = AF_INET;
+		sin->sin_len = sizeof(*sin);
+		sin->sin_addr = dst;
+
+		rtalloc(&ipforward_rt);
+	}
+	if (ipforward_rt.ro_rt == 0)
+		return ((struct in_ifaddr *)0);
+	return (ifatoia(ipforward_rt.ro_rt->rt_ifa));
+}
+
+/*
+ * Save incoming source route for use in replies,
+ * to be picked up later by ip_srcroute if the receiver is interested.
+ */
+void
+save_rte(option, dst)
+	u_char *option;
+	struct in_addr dst;
+{
+	unsigned olen;
+
+	olen = option[IPOPT_OLEN];
+#ifdef DIAGNOSTIC
+	if (ipprintfs)
+		printf("save_rte: olen %d\n", olen);
+#endif /* 0 */
+	if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
+		return;
+	bcopy((caddr_t)option, (caddr_t)ip_srcrt.srcopt, olen);
+	ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
+	ip_srcrt.dst = dst;
+}
+
+/*
+ * Check whether we do proxy ARP for this address and we point to ourselves.
+ * Code shamelessly copied from arplookup().
+ */
+static int
+ip_weadvertise(addr)
+	u_int32_t addr;
+{
+	register struct rtentry *rt;
+	register struct ifnet *ifp;
+	register struct ifaddr *ifa;
+	struct sockaddr_inarp sin;
+
+	sin.sin_len = sizeof(sin);
+	sin.sin_family = AF_INET;
+	sin.sin_addr.s_addr = addr;
+	sin.sin_other = SIN_PROXY;
+	rt = rtalloc1(sintosa(&sin), 0);
+	if (rt == 0)
+	  return 0;
+	
+	RTFREE(rt);
+	
+	if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 ||
+	    rt->rt_gateway->sa_family != AF_LINK)
+	  return 0;
+
+	for (ifp = ifnet.tqh_first; ifp != 0; ifp = ifp->if_list.tqe_next)
+		for (ifa = ifp->if_addrlist.tqh_first; ifa != 0;
+		    ifa = ifa->ifa_list.tqe_next) {
+			if (ifa->ifa_addr->sa_family != rt->rt_gateway->sa_family)
+				continue;
+
+			if (!bcmp(LLADDR((struct sockaddr_dl *)ifa->ifa_addr), 
+			    LLADDR((struct sockaddr_dl *)rt->rt_gateway),
+			    ETHER_ADDR_LEN))
+				return 1;
+		}
+
+	return 0;
+}
+
+/*
+ * Retrieve incoming source route for use in replies,
+ * in the same form used by setsockopt.
+ * The first hop is placed before the options, will be removed later.
+ */
+struct mbuf *
+ip_srcroute()
+{
+	register struct in_addr *p, *q;
+	register struct mbuf *m;
+
+	if (ip_nhops == 0)
+		return ((struct mbuf *)0);
+	m = m_get(M_DONTWAIT, MT_SOOPTS);
+	if (m == 0)
+		return ((struct mbuf *)0);
+
+#define OPTSIZ	(sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
+
+	/* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
+	m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
+	    OPTSIZ;
+#ifdef DIAGNOSTIC
+	if (ipprintfs)
+		printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
+#endif
+
+	/*
+	 * First save first hop for return route
+	 */
+	p = &ip_srcrt.route[ip_nhops - 1];
+	*(mtod(m, struct in_addr *)) = *p--;
+#ifdef DIAGNOSTIC
+	if (ipprintfs)
+		printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
+#endif
+
+	/*
+	 * Copy option fields and padding (nop) to mbuf.
+	 */
+	ip_srcrt.nop = IPOPT_NOP;
+	ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
+	bcopy((caddr_t)&ip_srcrt.nop,
+	    mtod(m, caddr_t) + sizeof(struct in_addr), OPTSIZ);
+	q = (struct in_addr *)(mtod(m, caddr_t) +
+	    sizeof(struct in_addr) + OPTSIZ);
+#undef OPTSIZ
+	/*
+	 * Record return path as an IP source route,
+	 * reversing the path (pointers are now aligned).
+	 */
+	while (p >= ip_srcrt.route) {
+#ifdef DIAGNOSTIC
+		if (ipprintfs)
+			printf(" %x", ntohl(q->s_addr));
+#endif
+		*q++ = *p--;
+	}
+	/*
+	 * Last hop goes to final destination.
+	 */
+	*q = ip_srcrt.dst;
+#ifdef DIAGNOSTIC
+	if (ipprintfs)
+		printf(" %x\n", ntohl(q->s_addr));
+#endif
+	return (m);
+}
+
+/*
+ * Strip out IP options, at higher
+ * level protocol in the kernel.
+ * Second argument is buffer to which options
+ * will be moved, and return value is their length.
+ * XXX should be deleted; last arg currently ignored.
+ */
+void
+ip_stripoptions(m, mopt)
+	register struct mbuf *m;
+	struct mbuf *mopt;
+{
+	register int i;
+	struct ip *ip = mtod(m, struct ip *);
+	register caddr_t opts;
+	int olen;
+
+	olen = (ip->ip_hl<<2) - sizeof (struct ip);
+	opts = (caddr_t)(ip + 1);
+	i = m->m_len - (sizeof (struct ip) + olen);
+	bcopy(opts  + olen, opts, (unsigned)i);
+	m->m_len -= olen;
+	if (m->m_flags & M_PKTHDR)
+		m->m_pkthdr.len -= olen;
+	ip->ip_hl = sizeof(struct ip) >> 2;
+}
+
+int inetctlerrmap[PRC_NCMDS] = {
+	0,		0,		0,		0,
+	0,		EMSGSIZE,	EHOSTDOWN,	EHOSTUNREACH,
+	EHOSTUNREACH,	EHOSTUNREACH,	ECONNREFUSED,	ECONNREFUSED,
+	EMSGSIZE,	EHOSTUNREACH,	0,		0,
+	0,		0,		0,		0,
+	ENOPROTOOPT
+};
+
+/*
+ * Forward a packet.  If some error occurs return the sender
+ * an icmp packet.  Note we can't always generate a meaningful
+ * icmp message because icmp doesn't have a large enough repertoire
+ * of codes and types.
+ *
+ * If not forwarding, just drop the packet.  This could be confusing
+ * if ipforwarding was zero but some routing protocol was advancing
+ * us as a gateway to somewhere.  However, we must let the routing
+ * protocol deal with that.
+ *
+ * The srcrt parameter indicates whether the packet is being forwarded
+ * via a source route.
+ */
+void
+ip_forward(m, srcrt)
+	struct mbuf *m;
+	int srcrt;
+{
+	register struct ip *ip = mtod(m, struct ip *);
+	register struct sockaddr_in *sin;
+	register struct rtentry *rt;
+	int error, type = 0, code = 0;
+	struct mbuf *mcopy;
+	n_long dest;
+	struct ifnet *destifp;
+#if 0 /*KAME IPSEC*/
+	struct ifnet dummyifp;
+#endif
+
+	dest = 0;
+#ifdef DIAGNOSTIC
+	if (ipprintfs)
+		printf("forward: src %x dst %x ttl %x\n", ip->ip_src.s_addr,
+		    ip->ip_dst.s_addr, ip->ip_ttl);
+#endif
+	if (m->m_flags & M_BCAST || in_canforward(ip->ip_dst) == 0) {
+		ipstat.ips_cantforward++;
+		m_freem(m);
+		return;
+	}
+	HTONS(ip->ip_id);
+	if (ip->ip_ttl <= IPTTLDEC) {
+		icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
+		return;
+	}
+	ip->ip_ttl -= IPTTLDEC;
+
+	sin = satosin(&ipforward_rt.ro_dst);
+	if ((rt = ipforward_rt.ro_rt) == 0 ||
+	    ip->ip_dst.s_addr != sin->sin_addr.s_addr) {
+		if (ipforward_rt.ro_rt) {
+			RTFREE(ipforward_rt.ro_rt);
+			ipforward_rt.ro_rt = 0;
+		}
+		sin->sin_family = AF_INET;
+		sin->sin_len = sizeof(*sin);
+		sin->sin_addr = ip->ip_dst;
+
+		rtalloc(&ipforward_rt);
+		if (ipforward_rt.ro_rt == 0) {
+			icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
+			return;
+		}
+		rt = ipforward_rt.ro_rt;
+	}
+
+	/*
+	 * Save at most 68 bytes of the packet in case
+	 * we need to generate an ICMP message to the src.
+	 */
+	mcopy = m_copy(m, 0, imin((int)ip->ip_len, 68));
+
+	/*
+	 * If forwarding packet using same interface that it came in on,
+	 * perhaps should send a redirect to sender to shortcut a hop.
+	 * Only send redirect if source is sending directly to us,
+	 * and if packet was not source routed (or has any options).
+	 * Also, don't send redirect if forwarding using a default route
+	 * or a route modified by a redirect.
+	 * Don't send redirect if we advertise destination's arp address
+	 * as ours (proxy arp).
+	 */
+	if (rt->rt_ifp == m->m_pkthdr.rcvif &&
+	    (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
+	    satosin(rt_key(rt))->sin_addr.s_addr != 0 &&
+	    ipsendredirects && !srcrt &&
+	    !ip_weadvertise(satosin(rt_key(rt))->sin_addr.s_addr)) {
+		if (rt->rt_ifa &&
+		    (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
+		    ifatoia(rt->rt_ifa)->ia_subnet) {
+		    if (rt->rt_flags & RTF_GATEWAY)
+			dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
+		    else
+			dest = ip->ip_dst.s_addr;
+		    /* Router requirements says to only send host redirects */
+		    type = ICMP_REDIRECT;
+		    code = ICMP_REDIRECT_HOST;
+#ifdef DIAGNOSTIC
+		    if (ipprintfs)
+			printf("redirect (%d) to %x\n", code, (u_int32_t)dest);
+#endif
+		}
+	}
+
+#if 0 /*KAME IPSEC*/
+	m->m_pkthdr.rcvif = NULL;
+#endif /*IPSEC*/
+	error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
+	    (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)), 
+	    0, NULL, NULL);
+	if (error)
+		ipstat.ips_cantforward++;
+	else {
+		ipstat.ips_forward++;
+		if (type)
+			ipstat.ips_redirectsent++;
+		else {
+			if (mcopy)
+				m_freem(mcopy);
+			return;
+		}
+	}
+	if (mcopy == NULL)
+		return;
+	destifp = NULL;
+
+	switch (error) {
+
+	case 0:				/* forwarded, but need redirect */
+		/* type, code set above */
+		break;
+
+	case ENETUNREACH:		/* shouldn't happen, checked above */
+	case EHOSTUNREACH:
+	case ENETDOWN:
+	case EHOSTDOWN:
+	default:
+		type = ICMP_UNREACH;
+		code = ICMP_UNREACH_HOST;
+		break;
+
+	case EMSGSIZE:
+		type = ICMP_UNREACH;
+		code = ICMP_UNREACH_NEEDFRAG;
+#if 1 /*KAME IPSEC*/
+		if (ipforward_rt.ro_rt)
+			destifp = ipforward_rt.ro_rt->rt_ifp;
+#else
+		/*
+		 * If the packet is routed over IPsec tunnel, tell the
+		 * originator the tunnel MTU.
+		 *	tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
+		 * XXX quickhack!!!
+		 */
+		if (ipforward_rt.ro_rt) {
+			struct secpolicy *sp;
+			int ipsecerror;
+			int ipsechdr;
+			struct route *ro;
+
+			sp = ipsec4_getpolicybyaddr(mcopy,
+						    IP_FORWARDING,
+						    &ipsecerror);
+
+			if (sp == NULL)
+				destifp = ipforward_rt.ro_rt->rt_ifp;
+			else {
+				/* count IPsec header size */
+				ipsechdr = ipsec4_hdrsiz(mcopy, NULL);
+
+				/*
+				 * find the correct route for outer IPv4
+				 * header, compute tunnel MTU.
+				 *
+				 * XXX BUG ALERT
+				 * The "dummyifp" code relies upon the fact
+				 * that icmp_error() touches only ifp->if_mtu.
+				 */
+				/*XXX*/
+				destifp = NULL;
+				if (sp->req != NULL
+				 && sp->req->sa != NULL) {
+					ro = &sp->req->sa->saidx->sa_route;
+					if (ro->ro_rt && ro->ro_rt->rt_ifp) {
+						dummyifp.if_mtu =
+						    ro->ro_rt->rt_ifp->if_mtu;
+						dummyifp.if_mtu -= ipsechdr;
+						destifp = &dummyifp;
+					}
+				}
+
+				key_freesp(sp);
+			}
+		}
+#endif /*IPSEC*/
+		ipstat.ips_cantfrag++;
+		break;
+
+	case ENOBUFS:
+		type = ICMP_SOURCEQUENCH;
+		code = 0;
+		break;
+	}
+
+	icmp_error(mcopy, type, code, dest, destifp);
+}
+
+#ifdef CYGPKG_NET_SYSCTL
+int
+ip_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
+	int *name;
+	u_int namelen;
+	void *oldp;
+	size_t *oldlenp;
+	void *newp;
+	size_t newlen;
+{
+	/* All sysctl names at this level are terminal. */
+	if (namelen != 1)
+		return (ENOTDIR);
+
+	switch (name[0]) {
+	case IPCTL_FORWARDING:
+		return (sysctl_int(oldp, oldlenp, newp, newlen, &ipforwarding));
+	case IPCTL_SENDREDIRECTS:
+		return (sysctl_int(oldp, oldlenp, newp, newlen,
+			&ipsendredirects));
+	case IPCTL_DEFTTL:
+		return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_defttl));
+#ifdef notyet
+	case IPCTL_DEFMTU:
+		return (sysctl_int(oldp, oldlenp, newp, newlen, &ip_mtu));
+#endif
+	case IPCTL_SOURCEROUTE:
+		/*
+		 * Don't allow this to change in a secure environment.
+		 */
+		if (newp && securelevel > 0)
+			return (EPERM);
+		return (sysctl_int(oldp, oldlenp, newp, newlen,
+		    &ip_dosourceroute));
+	case IPCTL_DIRECTEDBCAST:
+		return (sysctl_int(oldp, oldlenp, newp, newlen,
+		    &ip_directedbcast));
+	case IPCTL_IPPORT_FIRSTAUTO:
+		return (sysctl_int(oldp, oldlenp, newp, newlen,
+		    &ipport_firstauto));
+	case IPCTL_IPPORT_LASTAUTO:
+		return (sysctl_int(oldp, oldlenp, newp, newlen,
+		    &ipport_lastauto));
+	case IPCTL_IPPORT_HIFIRSTAUTO:
+		return (sysctl_int(oldp, oldlenp, newp, newlen,
+		    &ipport_hifirstauto));
+	case IPCTL_IPPORT_HILASTAUTO:
+		return (sysctl_int(oldp, oldlenp, newp, newlen,
+		    &ipport_hilastauto));
+	case IPCTL_IPPORT_MAXQUEUE:
+		return (sysctl_int(oldp, oldlenp, newp, newlen,
+		    &ip_maxqueue));
+	case IPCTL_ENCDEBUG:
+		return (sysctl_int(oldp, oldlenp, newp, newlen, &encdebug));
+	default:
+		return (EOPNOTSUPP);
+	}
+	/* NOTREACHED */
+}
+#endif // CYGPKG_NET_SYSCTL