initial import of NetBSD tree

22 files changed, 5996 insertions, 0 deletions

diff --git a/sys/netns/idp.h b/sys/netns/idp.h
new file mode 100644
index 00000000000..1d176b40211
--- /dev/null
+++ b/sys/netns/idp.h
@@ -0,0 +1,48 @@
+/*	$NetBSD: idp.h,v 1.5 1994/06/29 06:41:28 cgd Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)idp.h	8.1 (Berkeley) 6/10/93
+ */
+
+/*
+ * Definitions for NS(tm) Internet Datagram Protocol
+ */
+struct idp {
+	u_short	idp_sum;	/* Checksum */
+	u_short	idp_len;	/* Length, in bytes, including header */
+	u_char	idp_tc;		/* Transport Crontrol (i.e. hop count) */
+	u_char	idp_pt;		/* Packet Type (i.e. level 2 protocol) */
+	struct ns_addr	idp_dna;	/* Destination Network Address */
+	struct ns_addr	idp_sna;	/* Source Network Address */
+};
diff --git a/sys/netns/idp_usrreq.c b/sys/netns/idp_usrreq.c
new file mode 100644
index 00000000000..c5406011ecf
--- /dev/null
+++ b/sys/netns/idp_usrreq.c
@@ -0,0 +1,569 @@
+/*	$NetBSD: idp_usrreq.c,v 1.8 1995/08/12 23:59:56 mycroft Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)idp_usrreq.c	8.1 (Berkeley) 6/10/93
+ */
+
+#include <sys/param.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/protosw.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/errno.h>
+#include <sys/stat.h>
+
+#include <net/if.h>
+#include <net/route.h>
+
+#include <netns/ns.h>
+#include <netns/ns_pcb.h>
+#include <netns/ns_if.h>
+#include <netns/idp.h>
+#include <netns/idp_var.h>
+#include <netns/ns_error.h>
+
+/*
+ * IDP protocol implementation.
+ */
+
+struct	sockaddr_ns idp_ns = { sizeof(idp_ns), AF_NS };
+
+/*
+ *  This may also be called for raw listeners.
+ */
+idp_input(m, nsp)
+	struct mbuf *m;
+	register struct nspcb *nsp;
+{
+	register struct idp *idp = mtod(m, struct idp *);
+	struct ifnet *ifp = m->m_pkthdr.rcvif;
+
+	if (nsp==0)
+		panic("No nspcb");
+	/*
+	 * Construct sockaddr format source address.
+	 * Stuff source address and datagram in user buffer.
+	 */
+	idp_ns.sns_addr = idp->idp_sna;
+	if (ns_neteqnn(idp->idp_sna.x_net, ns_zeronet) && ifp) {
+		register struct ifaddr *ifa;
+
+		for (ifa = ifp->if_addrlist.tqh_first; ifa != 0;
+		    ifa = ifa->ifa_list.tqe_next) {
+			if (ifa->ifa_addr->sa_family == AF_NS) {
+				idp_ns.sns_addr.x_net =
+					IA_SNS(ifa)->sns_addr.x_net;
+				break;
+			}
+		}
+	}
+	nsp->nsp_rpt = idp->idp_pt;
+	if ( ! (nsp->nsp_flags & NSP_RAWIN) ) {
+		m->m_len -= sizeof (struct idp);
+		m->m_pkthdr.len -= sizeof (struct idp);
+		m->m_data += sizeof (struct idp);
+	}
+	if (sbappendaddr(&nsp->nsp_socket->so_rcv, snstosa(&idp_ns), m,
+	    (struct mbuf *)0) == 0)
+		goto bad;
+	sorwakeup(nsp->nsp_socket);
+	return;
+bad:
+	m_freem(m);
+}
+
+idp_abort(nsp)
+	struct nspcb *nsp;
+{
+	struct socket *so = nsp->nsp_socket;
+
+	ns_pcbdisconnect(nsp);
+	soisdisconnected(so);
+}
+/*
+ * Drop connection, reporting
+ * the specified error.
+ */
+struct nspcb *
+idp_drop(nsp, errno)
+	register struct nspcb *nsp;
+	int errno;
+{
+	struct socket *so = nsp->nsp_socket;
+
+	/*
+	 * someday, in the xerox world
+	 * we will generate error protocol packets
+	 * announcing that the socket has gone away.
+	 */
+	/*if (TCPS_HAVERCVDSYN(tp->t_state)) {
+		tp->t_state = TCPS_CLOSED;
+		(void) tcp_output(tp);
+	}*/
+	so->so_error = errno;
+	ns_pcbdisconnect(nsp);
+	soisdisconnected(so);
+}
+
+int noIdpRoute;
+idp_output(nsp, m0)
+	struct nspcb *nsp;
+	struct mbuf *m0;
+{
+	register struct mbuf *m;
+	register struct idp *idp;
+	register struct socket *so;
+	register int len = 0;
+	register struct route *ro;
+	struct mbuf *mprev;
+	extern int idpcksum;
+
+	/*
+	 * Calculate data length.
+	 */
+	for (m = m0; m; m = m->m_next) {
+		mprev = m;
+		len += m->m_len;
+	}
+	/*
+	 * Make sure packet is actually of even length.
+	 */
+	
+	if (len & 1) {
+		m = mprev;
+		if ((m->m_flags & M_EXT) == 0 &&
+			(m->m_len + m->m_data < &m->m_dat[MLEN])) {
+			m->m_len++;
+		} else {
+			struct mbuf *m1 = m_get(M_DONTWAIT, MT_DATA);
+
+			if (m1 == 0) {
+				m_freem(m0);
+				return (ENOBUFS);
+			}
+			m1->m_len = 1;
+			* mtod(m1, char *) = 0;
+			m->m_next = m1;
+		}
+		m0->m_pkthdr.len++;
+	}
+
+	/*
+	 * Fill in mbuf with extended IDP header
+	 * and addresses and length put into network format.
+	 */
+	m = m0;
+	if (nsp->nsp_flags & NSP_RAWOUT) {
+		idp = mtod(m, struct idp *);
+	} else {
+		M_PREPEND(m, sizeof (struct idp), M_DONTWAIT);
+		if (m == 0)
+			return (ENOBUFS);
+		idp = mtod(m, struct idp *);
+		idp->idp_tc = 0;
+		idp->idp_pt = nsp->nsp_dpt;
+		idp->idp_sna = nsp->nsp_laddr;
+		idp->idp_dna = nsp->nsp_faddr;
+		len += sizeof (struct idp);
+	}
+
+	idp->idp_len = htons((u_short)len);
+
+	if (idpcksum) {
+		idp->idp_sum = 0;
+		len = ((len - 1) | 1) + 1;
+		idp->idp_sum = ns_cksum(m, len);
+	} else
+		idp->idp_sum = 0xffff;
+
+	/*
+	 * Output datagram.
+	 */
+	so = nsp->nsp_socket;
+	if (so->so_options & SO_DONTROUTE)
+		return (ns_output(m, (struct route *)0,
+		    (so->so_options & SO_BROADCAST) | NS_ROUTETOIF));
+	/*
+	 * Use cached route for previous datagram if
+	 * possible.  If the previous net was the same
+	 * and the interface was a broadcast medium, or
+	 * if the previous destination was identical,
+	 * then we are ok.
+	 *
+	 * NB: We don't handle broadcasts because that
+	 *     would require 3 subroutine calls.
+	 */
+	ro = &nsp->nsp_route;
+#ifdef ancient_history
+	/*
+	 * I think that this will all be handled in ns_pcbconnect!
+	 */
+	if (ro->ro_rt) {
+		if(ns_neteq(nsp->nsp_lastdst, idp->idp_dna)) {
+			/*
+			 * This assumes we have no GH type routes
+			 */
+			if (ro->ro_rt->rt_flags & RTF_HOST) {
+				if (!ns_hosteq(nsp->nsp_lastdst, idp->idp_dna))
+					goto re_route;
+
+			}
+			if ((ro->ro_rt->rt_flags & RTF_GATEWAY) == 0) {
+				register struct ns_addr *dst =
+						&satons_addr(ro->ro_dst);
+				dst->x_host = idp->idp_dna.x_host;
+			}
+			/* 
+			 * Otherwise, we go through the same gateway
+			 * and dst is already set up.
+			 */
+		} else {
+		re_route:
+			RTFREE(ro->ro_rt);
+			ro->ro_rt = (struct rtentry *)0;
+		}
+	}
+	nsp->nsp_lastdst = idp->idp_dna;
+#endif /* ancient_history */
+	if (noIdpRoute) ro = 0;
+	return (ns_output(m, ro, so->so_options & SO_BROADCAST));
+}
+/* ARGSUSED */
+idp_ctloutput(req, so, level, name, value)
+	int req, level;
+	struct socket *so;
+	int name;
+	struct mbuf **value;
+{
+	register struct mbuf *m;
+	struct nspcb *nsp = sotonspcb(so);
+	int mask, error = 0;
+	extern long ns_pexseq;
+
+	if (nsp == NULL)
+		return (EINVAL);
+
+	switch (req) {
+
+	case PRCO_GETOPT:
+		if (value==NULL)
+			return (EINVAL);
+		m = m_get(M_DONTWAIT, MT_DATA);
+		if (m==NULL)
+			return (ENOBUFS);
+		switch (name) {
+
+		case SO_ALL_PACKETS:
+			mask = NSP_ALL_PACKETS;
+			goto get_flags;
+
+		case SO_HEADERS_ON_INPUT:
+			mask = NSP_RAWIN;
+			goto get_flags;
+			
+		case SO_HEADERS_ON_OUTPUT:
+			mask = NSP_RAWOUT;
+		get_flags:
+			m->m_len = sizeof(short);
+			*mtod(m, short *) = nsp->nsp_flags & mask;
+			break;
+
+		case SO_DEFAULT_HEADERS:
+			m->m_len = sizeof(struct idp);
+			{
+				register struct idp *idp = mtod(m, struct idp *);
+				idp->idp_len = 0;
+				idp->idp_sum = 0;
+				idp->idp_tc = 0;
+				idp->idp_pt = nsp->nsp_dpt;
+				idp->idp_dna = nsp->nsp_faddr;
+				idp->idp_sna = nsp->nsp_laddr;
+			}
+			break;
+
+		case SO_SEQNO:
+			m->m_len = sizeof(long);
+			*mtod(m, long *) = ns_pexseq++;
+			break;
+
+		default:
+			error = EINVAL;
+		}
+		*value = m;
+		break;
+
+	case PRCO_SETOPT:
+		switch (name) {
+			int *ok;
+
+		case SO_ALL_PACKETS:
+			mask = NSP_ALL_PACKETS;
+			goto set_head;
+
+		case SO_HEADERS_ON_INPUT:
+			mask = NSP_RAWIN;
+			goto set_head;
+
+		case SO_HEADERS_ON_OUTPUT:
+			mask = NSP_RAWOUT;
+		set_head:
+			if (value && *value) {
+				ok = mtod(*value, int *);
+				if (*ok)
+					nsp->nsp_flags |= mask;
+				else
+					nsp->nsp_flags &= ~mask;
+			} else error = EINVAL;
+			break;
+
+		case SO_DEFAULT_HEADERS:
+			{
+				register struct idp *idp
+				    = mtod(*value, struct idp *);
+				nsp->nsp_dpt = idp->idp_pt;
+			}
+			break;
+#ifdef NSIP
+
+		case SO_NSIP_ROUTE:
+			error = nsip_route(*value);
+			break;
+#endif /* NSIP */
+		default:
+			error = EINVAL;
+		}
+		if (value && *value)
+			m_freem(*value);
+		break;
+	}
+	return (error);
+}
+
+/*ARGSUSED*/
+idp_usrreq(so, req, m, nam, control)
+	struct socket *so;
+	int req;
+	struct mbuf *m, *nam, *control;
+{
+	struct nspcb *nsp = sotonspcb(so);
+	int error = 0;
+
+	if (req == PRU_CONTROL)
+                return (ns_control(so, (long)m, (caddr_t)nam,
+			(struct ifnet *)control));
+	if (control && control->m_len) {
+		error = EINVAL;
+		goto release;
+	}
+	if (nsp == NULL && req != PRU_ATTACH) {
+		error = EINVAL;
+		goto release;
+	}
+	switch (req) {
+
+	case PRU_ATTACH:
+		if (nsp != NULL) {
+			error = EINVAL;
+			break;
+		}
+		error = ns_pcballoc(so, &nspcb);
+		if (error)
+			break;
+		error = soreserve(so, (u_long) 2048, (u_long) 2048);
+		if (error)
+			break;
+		break;
+
+	case PRU_DETACH:
+		if (nsp == NULL) {
+			error = ENOTCONN;
+			break;
+		}
+		ns_pcbdetach(nsp);
+		break;
+
+	case PRU_BIND:
+		error = ns_pcbbind(nsp, nam);
+		break;
+
+	case PRU_LISTEN:
+		error = EOPNOTSUPP;
+		break;
+
+	case PRU_CONNECT:
+		if (!ns_nullhost(nsp->nsp_faddr)) {
+			error = EISCONN;
+			break;
+		}
+		error = ns_pcbconnect(nsp, nam);
+		if (error == 0)
+			soisconnected(so);
+		break;
+
+	case PRU_CONNECT2:
+		error = EOPNOTSUPP;
+		break;
+
+	case PRU_ACCEPT:
+		error = EOPNOTSUPP;
+		break;
+
+	case PRU_DISCONNECT:
+		if (ns_nullhost(nsp->nsp_faddr)) {
+			error = ENOTCONN;
+			break;
+		}
+		ns_pcbdisconnect(nsp);
+		soisdisconnected(so);
+		break;
+
+	case PRU_SHUTDOWN:
+		socantsendmore(so);
+		break;
+
+	case PRU_SEND:
+	{
+		struct ns_addr laddr;
+		int s;
+
+		if (nam) {
+			laddr = nsp->nsp_laddr;
+			if (!ns_nullhost(nsp->nsp_faddr)) {
+				error = EISCONN;
+				break;
+			}
+			/*
+			 * Must block input while temporarily connected.
+			 */
+			s = splsoftnet();
+			error = ns_pcbconnect(nsp, nam);
+			if (error) {
+				splx(s);
+				break;
+			}
+		} else {
+			if (ns_nullhost(nsp->nsp_faddr)) {
+				error = ENOTCONN;
+				break;
+			}
+		}
+		error = idp_output(nsp, m);
+		m = NULL;
+		if (nam) {
+			ns_pcbdisconnect(nsp);
+			splx(s);
+			nsp->nsp_laddr.x_host = laddr.x_host;
+			nsp->nsp_laddr.x_port = laddr.x_port;
+		}
+	}
+		break;
+
+	case PRU_ABORT:
+		ns_pcbdetach(nsp);
+		sofree(so);
+		soisdisconnected(so);
+		break;
+
+	case PRU_SOCKADDR:
+		ns_setsockaddr(nsp, nam);
+		break;
+
+	case PRU_PEERADDR:
+		ns_setpeeraddr(nsp, nam);
+		break;
+
+	case PRU_SENSE:
+		/*
+		 * stat: don't bother with a blocksize.
+		 */
+		return (0);
+
+	case PRU_SENDOOB:
+	case PRU_FASTTIMO:
+	case PRU_SLOWTIMO:
+	case PRU_PROTORCV:
+	case PRU_PROTOSEND:
+		error =  EOPNOTSUPP;
+		break;
+
+	case PRU_CONTROL:
+	case PRU_RCVD:
+	case PRU_RCVOOB:
+		return (EOPNOTSUPP);	/* do not free mbuf's */
+
+	default:
+		panic("idp_usrreq");
+	}
+release:
+	if (control != NULL)
+		m_freem(control);
+	if (m != NULL)
+		m_freem(m);
+	return (error);
+}
+/*ARGSUSED*/
+idp_raw_usrreq(so, req, m, nam, control)
+	struct socket *so;
+	int req;
+	struct mbuf *m, *nam, *control;
+{
+	int error = 0;
+	struct nspcb *nsp = sotonspcb(so);
+	extern struct nspcb nsrawpcb;
+
+	switch (req) {
+
+	case PRU_ATTACH:
+
+		if (!(so->so_state & SS_PRIV) || (nsp != NULL)) {
+			error = EINVAL;
+			break;
+		}
+		error = ns_pcballoc(so, &nsrawpcb);
+		if (error)
+			break;
+		error = soreserve(so, (u_long) 2048, (u_long) 2048);
+		if (error)
+			break;
+		nsp = sotonspcb(so);
+		nsp->nsp_faddr.x_host = ns_broadhost;
+		nsp->nsp_flags = NSP_RAWIN | NSP_RAWOUT;
+		break;
+	default:
+		error = idp_usrreq(so, req, m, nam, control);
+	}
+	return (error);
+}
+
diff --git a/sys/netns/idp_var.h b/sys/netns/idp_var.h
new file mode 100644
index 00000000000..dc95be7df52
--- /dev/null
+++ b/sys/netns/idp_var.h
@@ -0,0 +1,51 @@
+/*	$NetBSD: idp_var.h,v 1.6 1995/03/26 20:36:17 jtc Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)idp_var.h	8.1 (Berkeley) 6/10/93
+ */
+
+/*
+ * IDP Kernel Structures and Variables
+ */
+struct	idpstat {
+	int	idps_badsum;		/* checksum bad */
+	int	idps_tooshort;		/* packet too short */
+	int	idps_toosmall;		/* not enough data */
+	int	idps_badhlen;		/* ip header length < data size */
+	int	idps_badlen;		/* ip length < ip header length */
+};
+
+#ifdef _KERNEL
+struct	idpstat	idpstat;
+#endif
diff --git a/sys/netns/ns.c b/sys/netns/ns.c
new file mode 100644
index 00000000000..7e2675833f5
--- /dev/null
+++ b/sys/netns/ns.c
@@ -0,0 +1,333 @@
+/*	$NetBSD: ns.c,v 1.9 1995/06/13 08:37:00 mycroft Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)ns.c	8.2 (Berkeley) 11/15/93
+ */
+
+#include <sys/param.h>
+#include <sys/mbuf.h>
+#include <sys/ioctl.h>
+#include <sys/protosw.h>
+#include <sys/errno.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+
+#include <net/if.h>
+#include <net/route.h>
+
+#include <netns/ns.h>
+#include <netns/ns_if.h>
+
+#ifdef NS
+
+struct ns_ifaddrhead ns_ifaddr;
+int ns_interfaces;
+extern struct sockaddr_ns ns_netmask, ns_hostmask;
+
+/*
+ * Generic internet control operations (ioctl's).
+ */
+/* ARGSUSED */
+ns_control(so, cmd, data, ifp)
+	struct socket *so;
+	u_long cmd;
+	caddr_t data;
+	register struct ifnet *ifp;
+{
+	register struct ifreq *ifr = (struct ifreq *)data;
+	register struct ns_aliasreq *ifra = (struct ns_aliasreq *)data;
+	register struct ns_ifaddr *ia;
+	struct ifaddr *ifa;
+	int error, dstIsNew, hostIsNew;
+
+	/*
+	 * Find address for this interface, if it exists.
+	 */
+	if (ifp == 0)
+		return (EADDRNOTAVAIL);
+	for (ia = ns_ifaddr.tqh_first; ia != 0; ia = ia->ia_list.tqe_next)
+		if (ia->ia_ifp == ifp)
+			break;
+
+	switch (cmd) {
+
+	case SIOCGIFADDR:
+		if (ia == 0)
+			return (EADDRNOTAVAIL);
+		*satosns(&ifr->ifr_addr) = ia->ia_addr;
+		return (0);
+
+
+	case SIOCGIFBRDADDR:
+		if (ia == 0)
+			return (EADDRNOTAVAIL);
+		if ((ifp->if_flags & IFF_BROADCAST) == 0)
+			return (EINVAL);
+		*satosns(&ifr->ifr_dstaddr) = ia->ia_broadaddr;
+		return (0);
+
+	case SIOCGIFDSTADDR:
+		if (ia == 0)
+			return (EADDRNOTAVAIL);
+		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
+			return (EINVAL);
+		*satosns(&ifr->ifr_dstaddr) = ia->ia_dstaddr;
+		return (0);
+	}
+
+	if ((so->so_state & SS_PRIV) == 0)
+		return (EPERM);
+
+	switch (cmd) {
+	case SIOCAIFADDR:
+	case SIOCDIFADDR:
+		if (ifra->ifra_addr.sns_family == AF_NS)
+		    for (; ia; ia = ia->ia_list.tqe_next) {
+			if (ia->ia_ifp == ifp  &&
+			    ns_neteq(ia->ia_addr.sns_addr,
+				  ifra->ifra_addr.sns_addr))
+			    break;
+		    }
+		if (cmd == SIOCDIFADDR && ia == 0)
+			return (EADDRNOTAVAIL);
+		/* FALLTHROUGH */
+
+	case SIOCSIFADDR:
+	case SIOCSIFDSTADDR:
+		if (ia == 0) {
+			ia = (struct ns_ifaddr *)
+				malloc(sizeof *ia, M_IFADDR, M_WAITOK);
+			if (ia == 0)
+				return (ENOBUFS);
+			bzero((caddr_t)ia, sizeof(*ia));
+			TAILQ_INSERT_TAIL(&ns_ifaddr, ia, ia_list);
+			TAILQ_INSERT_TAIL(&ifp->if_addrlist, (struct ifaddr *)ia,
+			    ifa_list);
+			ia->ia_ifa.ifa_addr = snstosa(&ia->ia_addr);
+			ia->ia_ifa.ifa_netmask = snstosa(&ns_netmask);
+			ia->ia_ifa.ifa_dstaddr = snstosa(&ia->ia_dstaddr);
+			ia->ia_ifp = ifp;
+			if (ifp->if_flags & IFF_BROADCAST) {
+				ia->ia_broadaddr.sns_family = AF_NS;
+				ia->ia_broadaddr.sns_len = sizeof(ia->ia_addr);
+				ia->ia_broadaddr.sns_addr.x_host = ns_broadhost;
+			}
+			ns_interfaces++;
+		}
+	}
+
+	switch (cmd) {
+		int error;
+
+	case SIOCSIFDSTADDR:
+		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
+			return (EINVAL);
+		if (ia->ia_flags & IFA_ROUTE) {
+			rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
+			ia->ia_flags &= ~IFA_ROUTE;
+		}
+		if (ifp->if_ioctl) {
+			error = (*ifp->if_ioctl)(ifp, SIOCSIFDSTADDR,
+			    (caddr_t)ia);
+			if (error)
+				return (error);
+		}
+		*snstosa(&ia->ia_dstaddr) = ifr->ifr_dstaddr;
+		return (0);
+
+	case SIOCSIFADDR:
+		return (ns_ifinit(ifp, ia, satosns(&ifr->ifr_addr), 1));
+
+	case SIOCDIFADDR:
+		ns_ifscrub(ifp, ia);
+		TAILQ_REMOVE(&ifp->if_addrlist, (struct ifaddr *)ia, ifa_list);
+		TAILQ_REMOVE(&ns_ifaddr, ia, ia_list);
+		IFAFREE((&ia->ia_ifa));
+		if (0 == --ns_interfaces) {
+			/*
+			 * We reset to virginity and start all over again
+			 */
+			ns_thishost = ns_zerohost;
+		}
+		return (0);
+	
+	case SIOCAIFADDR:
+		dstIsNew = 0; hostIsNew = 1;
+		if (ia->ia_addr.sns_family == AF_NS) {
+			if (ifra->ifra_addr.sns_len == 0) {
+				ifra->ifra_addr = ia->ia_addr;
+				hostIsNew = 0;
+			} else if (ns_neteq(ifra->ifra_addr.sns_addr,
+					 ia->ia_addr.sns_addr))
+				hostIsNew = 0;
+		}
+		if ((ifp->if_flags & IFF_POINTOPOINT) &&
+		    (ifra->ifra_dstaddr.sns_family == AF_NS)) {
+			if (hostIsNew == 0)
+				ns_ifscrub(ifp, ia);
+			ia->ia_dstaddr = ifra->ifra_dstaddr;
+			dstIsNew  = 1;
+		}
+		if (ifra->ifra_addr.sns_family == AF_NS &&
+					    (hostIsNew || dstIsNew))
+			error = ns_ifinit(ifp, ia, &ifra->ifra_addr, 0);
+		return (error);
+
+	default:
+		if (ifp->if_ioctl == 0)
+			return (EOPNOTSUPP);
+		return ((*ifp->if_ioctl)(ifp, cmd, data));
+	}
+}
+
+/*
+* Delete any previous route for an old address.
+*/
+ns_ifscrub(ifp, ia)
+	register struct ifnet *ifp;
+	register struct ns_ifaddr *ia; 
+{
+	if (ia->ia_flags & IFA_ROUTE) {
+		if (ifp->if_flags & IFF_POINTOPOINT) {
+			rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
+		} else
+			rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0);
+		ia->ia_flags &= ~IFA_ROUTE;
+	}
+}
+/*
+ * Initialize an interface's internet address
+ * and routing table entry.
+ */
+ns_ifinit(ifp, ia, sns, scrub)
+	register struct ifnet *ifp;
+	register struct ns_ifaddr *ia;
+	register struct sockaddr_ns *sns;
+{
+	struct sockaddr_ns oldaddr;
+	register union ns_host *h = &ia->ia_addr.sns_addr.x_host;
+	int s = splimp(), error;
+
+	/*
+	 * Set up new addresses.
+	 */
+	oldaddr = ia->ia_addr;
+	ia->ia_addr = *sns;
+	/*
+	 * The convention we shall adopt for naming is that
+	 * a supplied address of zero means that "we don't care".
+	 * if there is a single interface, use the address of that
+	 * interface as our 6 byte host address.
+	 * if there are multiple interfaces, use any address already
+	 * used.
+	 *
+	 * Give the interface a chance to initialize
+	 * if this is its first address,
+	 * and to validate the address if necessary.
+	 */
+	if (ns_hosteqnh(ns_thishost, ns_zerohost)) {
+		if (ifp->if_ioctl &&
+		     (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR,
+		    (caddr_t)ia)))
+			goto bad;
+		ns_thishost = *h;
+	} else if (ns_hosteqnh(sns->sns_addr.x_host, ns_zerohost)
+	    || ns_hosteqnh(sns->sns_addr.x_host, ns_thishost)) {
+		*h = ns_thishost;
+		if (ifp->if_ioctl &&
+		     (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR,
+		    (caddr_t)ia)))
+			goto bad;
+		if (!ns_hosteqnh(ns_thishost, *h)) {
+			error = EINVAL;
+			goto bad;
+		}
+	} else {
+		error = EINVAL;
+		goto bad;
+	}
+	ia->ia_ifa.ifa_metric = ifp->if_metric;
+	/*
+	 * Add route for the network.
+	 */
+	if (scrub) {
+		ia->ia_ifa.ifa_addr = snstosa(&oldaddr);
+		ns_ifscrub(ifp, ia);
+		ia->ia_ifa.ifa_addr = snstosa(&ia->ia_addr);
+	}
+	if (ifp->if_flags & IFF_POINTOPOINT)
+		rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
+	else {
+		ia->ia_broadaddr.sns_addr.x_net = ia->ia_addr.sns_addr.x_net;
+		rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_UP);
+	}
+	ia->ia_flags |= IFA_ROUTE;
+	splx(s);
+	return (0);
+bad:
+	ia->ia_addr = oldaddr;
+	splx(s);
+	return (error);
+}
+
+/*
+ * Return address info for specified internet network.
+ */
+struct ns_ifaddr *
+ns_iaonnetof(dst)
+	register struct ns_addr *dst;
+{
+	register struct ns_ifaddr *ia;
+	register struct ns_addr *compare;
+	register struct ifnet *ifp;
+	struct ns_ifaddr *ia_maybe = 0;
+	union ns_net net = dst->x_net;
+
+	for (ia = ns_ifaddr.tqh_first; ia != 0; ia = ia->ia_list.tqe_next) {
+		if (ifp = ia->ia_ifp) {
+			if (ifp->if_flags & IFF_POINTOPOINT) {
+				compare = &satons_addr(ia->ia_dstaddr);
+				if (ns_hosteq(*dst, *compare))
+					return (ia);
+				if (ns_neteqnn(net, ia->ia_addr.sns_addr.x_net))
+					ia_maybe = ia;
+			} else {
+				if (ns_neteqnn(net, ia->ia_addr.sns_addr.x_net))
+					return (ia);
+			}
+		}
+	}
+	return (ia_maybe);
+}
+#endif
diff --git a/sys/netns/ns.h b/sys/netns/ns.h
new file mode 100644
index 00000000000..2d3907a66ce
--- /dev/null
+++ b/sys/netns/ns.h
@@ -0,0 +1,156 @@
+/*	$NetBSD: ns.h,v 1.7 1995/06/13 08:37:01 mycroft Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)ns.h	8.1 (Berkeley) 6/10/93
+ */
+
+/*
+ * Constants and Structures defined by the Xerox Network Software
+ * per "Internet Transport Protocols", XSIS 028112, December 1981
+ */
+
+/*
+ * Protocols
+ */
+#define NSPROTO_RI	1		/* Routing Information */
+#define NSPROTO_ECHO	2		/* Echo Protocol */
+#define NSPROTO_ERROR	3		/* Error Protocol */
+#define NSPROTO_PE	4		/* Packet Exchange */
+#define NSPROTO_SPP	5		/* Sequenced Packet */
+#define NSPROTO_RAW	255		/* Placemarker*/
+#define NSPROTO_MAX	256		/* Placemarker*/
+
+
+/*
+ * Port/Socket numbers: network standard functions
+ */
+
+#define NSPORT_RI	1		/* Routing Information */
+#define NSPORT_ECHO	2		/* Echo */
+#define NSPORT_RE	3		/* Router Error */
+
+/*
+ * Ports < NSPORT_RESERVED are reserved for priveleged
+ * processes (e.g. root).
+ */
+#define NSPORT_RESERVED		3000
+
+/* flags passed to ns_output as last parameter */
+
+#define	NS_FORWARDING		0x1	/* most of idp header exists */
+#define	NS_ROUTETOIF		0x10	/* same as SO_DONTROUTE */
+#define	NS_ALLOWBROADCAST	SO_BROADCAST	/* can send broadcast packets */
+
+#define NS_MAXHOPS		15
+
+/* flags passed to get/set socket option */
+#define	SO_HEADERS_ON_INPUT	1
+#define	SO_HEADERS_ON_OUTPUT	2
+#define	SO_DEFAULT_HEADERS	3
+#define	SO_LAST_HEADER		4
+#define	SO_NSIP_ROUTE		5
+#define SO_SEQNO		6
+#define	SO_ALL_PACKETS		7
+#define SO_MTU			8
+
+
+/*
+ * NS addressing
+ */
+union ns_host {
+	u_char	c_host[6];
+	u_short	s_host[3];
+};
+
+union ns_net {
+	u_char	c_net[4];
+	u_short	s_net[2];
+};
+
+union ns_net_u {
+	union ns_net	net_e;
+	u_long		long_e;
+};
+
+struct ns_addr {
+	union ns_net	x_net;
+	union ns_host	x_host;
+	u_short	x_port;
+};
+
+/*
+ * Socket address, Xerox style
+ */
+struct sockaddr_ns {
+	u_char		sns_len;
+	u_char		sns_family;
+	struct ns_addr	sns_addr;
+	char		sns_zero[2];
+};
+#define sns_port sns_addr.x_port
+
+#ifdef vax
+#define ns_netof(a) (*(long *) & ((a).x_net)) /* XXX - not needed */
+#endif
+#define ns_neteqnn(a,b) (((a).s_net[0]==(b).s_net[0]) && \
+					((a).s_net[1]==(b).s_net[1]))
+#define ns_neteq(a,b) ns_neteqnn((a).x_net, (b).x_net)
+#define satons_addr(sa)	(((struct sockaddr_ns *)&(sa))->sns_addr)
+#define ns_hosteqnh(s,t) ((s).s_host[0] == (t).s_host[0] && \
+	(s).s_host[1] == (t).s_host[1] && (s).s_host[2] == (t).s_host[2])
+#define ns_hosteq(s,t) (ns_hosteqnh((s).x_host,(t).x_host))
+#define ns_nullhost(x) (((x).x_host.s_host[0]==0) && \
+	((x).x_host.s_host[1]==0) && ((x).x_host.s_host[2]==0))
+
+#ifdef _KERNEL
+extern struct domain nsdomain;
+union ns_host ns_thishost;
+union ns_host ns_zerohost;
+union ns_host ns_broadhost;
+union ns_net ns_zeronet;
+union ns_net ns_broadnet;
+u_short ns_cksum();
+
+#define	satosns(sa)	((struct sockaddr_ns *)(sa))
+#define	snstosa(sns)	((struct sockaddr *)(sns))
+#else
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+extern struct ns_addr ns_addr __P((const char *));
+extern char *ns_ntoa __P((struct ns_addr));
+__END_DECLS
+
+#endif
diff --git a/sys/netns/ns_cksum.c b/sys/netns/ns_cksum.c
new file mode 100644
index 00000000000..43fee723bdb
--- /dev/null
+++ b/sys/netns/ns_cksum.c
@@ -0,0 +1,206 @@
+/*	$NetBSD: ns_cksum.c,v 1.3 1995/03/08 02:14:53 cgd Exp $	*/
+
+/*
+ * Copyright (c) 1982, 1992, 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.
+ *
+ *	@(#)ns_cksum.c	8.1 (Berkeley) 6/10/93
+ */
+
+#include <sys/param.h>
+#include <sys/mbuf.h>
+
+/*
+ * Checksum routine for Network Systems Protocol Packets (Big-Endian).
+ *
+ * This routine is very heavily used in the network
+ * code and should be modified for each CPU to be as fast as possible.
+ */
+
+#define ADDCARRY(x)  { if ((x) > 65535) (x) -= 65535; }
+#define FOLD(x) {l_util.l = (x); (x) = l_util.s[0] + l_util.s[1]; ADDCARRY(x);}
+
+u_short
+ns_cksum(m, len)
+	register struct mbuf *m;
+	register int len;
+{
+	register u_int16_t *w;
+	register int sum = 0;
+	register int mlen = 0;
+	register int sum2;
+
+	union {
+		u_int16_t s[2];
+		int32_t l;
+	} l_util;
+
+	for (;m && len; m = m->m_next) {
+		if (m->m_len == 0)
+			continue;
+		/*
+		 * Each trip around loop adds in
+		 * word from one mbuf segment.
+		 */
+		w = mtod(m, u_int16_t *);
+		if (mlen == -1) {
+			/*
+			 * There is a byte left from the last segment;
+			 * ones-complement add it into the checksum.
+			 */
+#if BYTE_ORDER == BIG_ENDIAN
+			sum  += *(u_char *)w;
+#else
+			sum  += *(u_char *)w << 8;
+#endif
+			sum += sum;
+			w = (u_int16_t *)(1 + (char *)w);
+			mlen = m->m_len - 1;
+			len--;
+			FOLD(sum);
+		} else
+			mlen = m->m_len;
+		if (len < mlen)
+			mlen = len;
+		len -= mlen;
+		/*
+		 * We can do a 16 bit ones complement sum using
+		 * 32 bit arithmetic registers for adding,
+		 * with carries from the low added
+		 * into the high (by normal carry-chaining)
+		 * so long as we fold back before 16 carries have occured.
+		 */
+		if (1 & (long) w)
+			goto uuuuglyy;
+#ifndef TINY
+/* -DTINY reduces the size from 1250 to 550, but slows it down by 22% */
+		while ((mlen -= 32) >= 0) {
+			sum += w[0]; sum += sum; sum += w[1]; sum += sum;
+			sum += w[2]; sum += sum; sum += w[3]; sum += sum;
+			sum += w[4]; sum += sum; sum += w[5]; sum += sum;
+			sum += w[6]; sum += sum; sum += w[7]; sum += sum;
+			FOLD(sum);
+			sum += w[8]; sum += sum; sum += w[9]; sum += sum;
+			sum += w[10]; sum += sum; sum += w[11]; sum += sum;
+			sum += w[12]; sum += sum; sum += w[13]; sum += sum;
+			sum += w[14]; sum += sum; sum += w[15]; sum += sum;
+			FOLD(sum);
+			w += 16;
+		}
+		mlen += 32;
+#endif
+		while ((mlen -= 8) >= 0) {
+			sum += w[0]; sum += sum; sum += w[1]; sum += sum;
+			sum += w[2]; sum += sum; sum += w[3]; sum += sum;
+			FOLD(sum);
+			w += 4;
+		}
+		mlen += 8;
+		while ((mlen -= 2) >= 0) {
+			sum += *w++; sum += sum;
+		}
+		goto commoncase;
+uuuuglyy:
+#if BYTE_ORDER == BIG_ENDIAN
+#define ww(n) (((u_char *)w)[n + n + 1])
+#define vv(n) (((u_char *)w)[n + n])
+#else
+#if BYTE_ORDER == LITTLE_ENDIAN
+#define vv(n) (((u_char *)w)[n + n + 1])
+#define ww(n) (((u_char *)w)[n + n])
+#endif
+#endif
+		sum2 = 0;
+#ifndef TINY
+		while ((mlen -= 32) >= 0) {
+		    sum += ww(0); sum += sum; sum += ww(1); sum += sum;
+		    sum += ww(2); sum += sum; sum += ww(3); sum += sum;
+		    sum += ww(4); sum += sum; sum += ww(5); sum += sum;
+		    sum += ww(6); sum += sum; sum += ww(7); sum += sum;
+		    FOLD(sum);
+		    sum += ww(8); sum += sum; sum += ww(9); sum += sum;
+		    sum += ww(10); sum += sum; sum += ww(11); sum += sum;
+		    sum += ww(12); sum += sum; sum += ww(13); sum += sum;
+		    sum += ww(14); sum += sum; sum += ww(15); sum += sum;
+		    FOLD(sum);
+		    sum2 += vv(0); sum2 += sum2; sum2 += vv(1); sum2 += sum2;
+		    sum2 += vv(2); sum2 += sum2; sum2 += vv(3); sum2 += sum2;
+		    sum2 += vv(4); sum2 += sum2; sum2 += vv(5); sum2 += sum2;
+		    sum2 += vv(6); sum2 += sum2; sum2 += vv(7); sum2 += sum2;
+		    FOLD(sum2);
+		    sum2 += vv(8); sum2 += sum2; sum2 += vv(9); sum2 += sum2;
+		    sum2 += vv(10); sum2 += sum2; sum2 += vv(11); sum2 += sum2;
+		    sum2 += vv(12); sum2 += sum2; sum2 += vv(13); sum2 += sum2;
+		    sum2 += vv(14); sum2 += sum2; sum2 += vv(15); sum2 += sum2;
+		    FOLD(sum2);
+		    w += 16;
+		}
+		mlen += 32;
+#endif
+		while ((mlen -= 8) >= 0) {
+		    sum += ww(0); sum += sum; sum += ww(1); sum += sum;
+		    sum += ww(2); sum += sum; sum += ww(3); sum += sum;
+		    FOLD(sum);
+		    sum2 += vv(0); sum2 += sum2; sum2 += vv(1); sum2 += sum2;
+		    sum2 += vv(2); sum2 += sum2; sum2 += vv(3); sum2 += sum2;
+		    FOLD(sum2);
+		    w += 4;
+		}
+		mlen += 8;
+		while ((mlen -= 2) >= 0) {
+			sum += ww(0); sum += sum;
+			sum2 += vv(0); sum2 += sum2;
+			w++;
+		}
+		sum += (sum2 << 8);
+commoncase:
+		if (mlen == -1) {
+#if BYTE_ORDER == BIG_ENDIAN
+			sum += *(u_char *)w << 8;
+#else
+			sum += *(u_char *)w;
+#endif
+		}
+		FOLD(sum);
+	}
+	if (mlen == -1) {
+		/* We had an odd number of bytes to sum; assume a garbage
+		   byte of zero and clean up */
+		sum += sum;
+		FOLD(sum);
+	}
+	/*
+	 * sum has already been kept to low sixteen bits.
+	 * just examine result and exit.
+	 */
+	if(sum==0xffff) sum = 0;
+	return (sum);
+}
diff --git a/sys/netns/ns_error.c b/sys/netns/ns_error.c
new file mode 100644
index 00000000000..eb4a03999c8
--- /dev/null
+++ b/sys/netns/ns_error.c
@@ -0,0 +1,325 @@
+/*	$NetBSD: ns_error.c,v 1.5 1994/06/29 06:41:36 cgd Exp $	*/
+
+/*
+ * Copyright (c) 1984, 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.
+ *
+ *	@(#)ns_error.c	8.1 (Berkeley) 6/10/93
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/protosw.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+
+#include <net/route.h>
+
+#include <netns/ns.h>
+#include <netns/ns_pcb.h>
+#include <netns/idp.h>
+#include <netns/ns_error.h>
+
+#ifdef lint
+#define NS_ERRPRINTFS 1
+#endif
+
+#ifdef NS_ERRPRINTFS
+/*
+ * NS_ERR routines: error generation, receive packet processing, and
+ * routines to turnaround packets back to the originator.
+ */
+int	ns_errprintfs = 0;
+#endif
+
+ns_err_x(c)
+{
+	register u_short *w, *lim, *base = ns_errstat.ns_es_codes;
+	u_short x = c;
+
+	/*
+	 * zero is a legit error code, handle specially
+	 */
+	if (x == 0)
+		return (0);
+	lim = base + NS_ERR_MAX - 1;
+	for (w = base + 1; w < lim; w++) {
+		if (*w == 0)
+			*w = x;
+		if (*w == x)
+			break;
+	}
+	return (w - base);
+}
+
+/*
+ * Generate an error packet of type error
+ * in response to bad packet.
+ */
+
+ns_error(om, type, param)
+	struct mbuf *om;
+	int type;
+{
+	register struct ns_epidp *ep;
+	struct mbuf *m;
+	struct idp *nip;
+	register struct idp *oip = mtod(om, struct idp *);
+	extern int idpcksum;
+
+	/*
+	 * If this packet was sent to the echo port,
+	 * and nobody was there, just echo it.
+	 * (Yes, this is a wart!)
+	 */
+	if (type == NS_ERR_NOSOCK &&
+	    oip->idp_dna.x_port == htons(2) &&
+	    (type = ns_echo(om))==0)
+		return;
+
+#ifdef NS_ERRPRINTFS
+	if (ns_errprintfs)
+		printf("ns_err_error(%x, %d, %d)\n", oip, type, param);
+#endif
+	/*
+	 * Don't Generate error packets in response to multicasts.
+	 */
+	if (oip->idp_dna.x_host.c_host[0] & 1)
+		goto freeit;
+
+	ns_errstat.ns_es_error++;
+	/*
+	 * Make sure that the old IDP packet had 30 bytes of data to return;
+	 * if not, don't bother.  Also don't EVER error if the old
+	 * packet protocol was NS_ERR.
+	 */
+	if (oip->idp_len < sizeof(struct idp)) {
+		ns_errstat.ns_es_oldshort++;
+		goto freeit;
+	}
+	if (oip->idp_pt == NSPROTO_ERROR) {
+		ns_errstat.ns_es_oldns_err++;
+		goto freeit;
+	}
+
+	/*
+	 * First, formulate ns_err message
+	 */
+	m = m_gethdr(M_DONTWAIT, MT_HEADER);
+	if (m == NULL)
+		goto freeit;
+	m->m_len = sizeof(*ep);
+	MH_ALIGN(m, m->m_len);
+	ep = mtod(m, struct ns_epidp *);
+	if ((u_int)type > NS_ERR_TOO_BIG)
+		panic("ns_err_error");
+	ns_errstat.ns_es_outhist[ns_err_x(type)]++;
+	ep->ns_ep_errp.ns_err_num = htons((u_short)type);
+	ep->ns_ep_errp.ns_err_param = htons((u_short)param);
+	bcopy((caddr_t)oip, (caddr_t)&ep->ns_ep_errp.ns_err_idp, 42);
+	nip = &ep->ns_ep_idp;
+	nip->idp_len = sizeof(*ep);
+	nip->idp_len = htons((u_short)nip->idp_len);
+	nip->idp_pt = NSPROTO_ERROR;
+	nip->idp_tc = 0;
+	nip->idp_dna = oip->idp_sna;
+	nip->idp_sna = oip->idp_dna;
+	if (idpcksum) {
+		nip->idp_sum = 0;
+		nip->idp_sum = ns_cksum(m, sizeof(*ep));
+	} else 
+		nip->idp_sum = 0xffff;
+	(void) ns_output(m, (struct route *)0, 0);
+
+freeit:
+	m_freem(om);
+}
+
+ns_printhost(p)
+register struct ns_addr *p;
+{
+
+	printf("<net:%x%x,host:%x%x%x,port:%x>",
+			p->x_net.s_net[0],
+			p->x_net.s_net[1],
+			p->x_host.s_host[0],
+			p->x_host.s_host[1],
+			p->x_host.s_host[2],
+			p->x_port);
+
+}
+
+/*
+ * Process a received NS_ERR message.
+ */
+ns_err_input(m)
+	struct mbuf *m;
+{
+	register struct ns_errp *ep;
+	register struct ns_epidp *epidp = mtod(m, struct ns_epidp *);
+	register int i;
+	int type, code, param;
+
+	/*
+	 * Locate ns_err structure in mbuf, and check
+	 * that not corrupted and of at least minimum length.
+	 */
+#ifdef NS_ERRPRINTFS
+	if (ns_errprintfs) {
+		printf("ns_err_input from ");
+		ns_printhost(&epidp->ns_ep_idp.idp_sna);
+		printf("len %d\n", ntohs(epidp->ns_ep_idp.idp_len));
+	}
+#endif
+	i = sizeof (struct ns_epidp);
+ 	if (((m->m_flags & M_EXT) || m->m_len < i) &&
+ 		(m = m_pullup(m, i)) == 0)  {
+		ns_errstat.ns_es_tooshort++;
+		return;
+	}
+	ep = &(mtod(m, struct ns_epidp *)->ns_ep_errp);
+	type = ntohs(ep->ns_err_num);
+	param = ntohs(ep->ns_err_param);
+	ns_errstat.ns_es_inhist[ns_err_x(type)]++;
+
+#ifdef NS_ERRPRINTFS
+	/*
+	 * Message type specific processing.
+	 */
+	if (ns_errprintfs)
+		printf("ns_err_input, type %d param %d\n", type, param);
+#endif
+	if (type >= NS_ERR_TOO_BIG) {
+		goto badcode;
+	}
+	ns_errstat.ns_es_outhist[ns_err_x(type)]++;
+	switch (type) {
+
+	case NS_ERR_UNREACH_HOST:
+		code = PRC_UNREACH_NET;
+		goto deliver;
+
+	case NS_ERR_TOO_OLD:
+		code = PRC_TIMXCEED_INTRANS;
+		goto deliver;
+
+	case NS_ERR_TOO_BIG:
+		code = PRC_MSGSIZE;
+		goto deliver;
+
+	case NS_ERR_FULLUP:
+		code = PRC_QUENCH;
+		goto deliver;
+
+	case NS_ERR_NOSOCK:
+		code = PRC_UNREACH_PORT;
+		goto deliver;
+
+	case NS_ERR_UNSPEC_T:
+	case NS_ERR_BADSUM_T:
+	case NS_ERR_BADSUM:
+	case NS_ERR_UNSPEC:
+		code = PRC_PARAMPROB;
+		goto deliver;
+
+	deliver:
+		/*
+		 * Problem with datagram; advise higher level routines.
+		 */
+#ifdef NS_ERRPRINTFS
+		if (ns_errprintfs)
+			printf("deliver to protocol %d\n",
+				       ep->ns_err_idp.idp_pt);
+#endif
+		switch(ep->ns_err_idp.idp_pt) {
+		case NSPROTO_SPP:
+			spp_ctlinput(code, (caddr_t)ep);
+			break;
+
+		default:
+			idp_ctlinput(code, (caddr_t)ep);
+		}
+		
+		goto freeit;
+
+	default:
+	badcode:
+		ns_errstat.ns_es_badcode++;
+		goto freeit;
+
+	}
+freeit:
+	m_freem(m);
+}
+
+#ifdef notdef
+u_long
+nstime()
+{
+	int s = splclock();
+	u_long t;
+
+	t = (time.tv_sec % (24*60*60)) * 1000 + time.tv_usec / 1000;
+	splx(s);
+	return (htonl(t));
+}
+#endif
+
+ns_echo(m)
+struct mbuf *m;
+{
+	register struct idp *idp = mtod(m, struct idp *);
+	register struct echo {
+	    struct idp	ec_idp;
+	    u_short		ec_op; /* Operation, 1 = request, 2 = reply */
+	} *ec = (struct echo *)idp;
+	struct ns_addr temp;
+
+	if (idp->idp_pt!=NSPROTO_ECHO) return(NS_ERR_NOSOCK);
+	if (ec->ec_op!=htons(1)) return(NS_ERR_UNSPEC);
+
+	ec->ec_op = htons(2);
+
+	temp = idp->idp_dna;
+	idp->idp_dna = idp->idp_sna;
+	idp->idp_sna = temp;
+
+	if (idp->idp_sum != 0xffff) {
+		idp->idp_sum = 0;
+		idp->idp_sum = ns_cksum(m,
+		    (int)(((ntohs(idp->idp_len) - 1)|1)+1));
+	}
+	(void) ns_output(m, (struct route *)0, NS_FORWARDING);
+	return(0);
+}
diff --git a/sys/netns/ns_error.h b/sys/netns/ns_error.h
new file mode 100644
index 00000000000..9167acd4c47
--- /dev/null
+++ b/sys/netns/ns_error.h
@@ -0,0 +1,92 @@
+/*	$NetBSD: ns_error.h,v 1.6 1995/03/26 20:36:20 jtc Exp $	*/
+
+/*
+ * Copyright (c) 1984, 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.
+ *
+ *	@(#)ns_error.h	8.1 (Berkeley) 6/10/93
+ */
+
+/*
+ * Xerox NS error messages
+ */
+
+struct ns_errp {
+	u_short		ns_err_num;		/* Error Number */
+	u_short		ns_err_param;		/* Error Parameter */
+	struct idp	ns_err_idp;		/* Initial segment of offending
+						   packet */
+	u_char		ns_err_lev2[12];	/* at least this much higher
+						   level protocol */
+};
+struct  ns_epidp {
+	struct idp ns_ep_idp;
+	struct ns_errp ns_ep_errp;
+};
+
+#define	NS_ERR_UNSPEC	0	/* Unspecified Error detected at dest. */
+#define	NS_ERR_BADSUM	1	/* Bad Checksum detected at dest */
+#define	NS_ERR_NOSOCK	2	/* Specified socket does not exist at dest*/
+#define	NS_ERR_FULLUP	3	/* Dest. refuses packet due to resource lim.*/
+#define	NS_ERR_UNSPEC_T	0x200	/* Unspec. Error occured before reaching dest*/
+#define	NS_ERR_BADSUM_T	0x201	/* Bad Checksum detected in transit */
+#define	NS_ERR_UNREACH_HOST	0x202	/* Dest cannot be reached from here*/
+#define	NS_ERR_TOO_OLD	0x203	/* Packet x'd 15 routers without delivery*/
+#define	NS_ERR_TOO_BIG	0x204	/* Packet too large to be forwarded through
+				   some intermediate gateway.  The error
+				   parameter field contains the max packet
+				   size that can be accommodated */
+#define NS_ERR_MAX 20
+
+/*
+ * Variables related to this implementation
+ * of the network systems error message protocol.
+ */
+struct	ns_errstat {
+/* statistics related to ns_err packets generated */
+	int	ns_es_error;		/* # of calls to ns_error */
+	int	ns_es_oldshort;		/* no error 'cuz old ip too short */
+	int	ns_es_oldns_err;	/* no error 'cuz old was ns_err */
+	int	ns_es_outhist[NS_ERR_MAX];
+/* statistics related to input messages processed */
+	int	ns_es_badcode;		/* ns_err_code out of range */
+	int	ns_es_tooshort;		/* packet < IDP_MINLEN */
+	int	ns_es_checksum;		/* bad checksum */
+	int	ns_es_badlen;		/* calculated bound mismatch */
+	int	ns_es_reflect;		/* number of responses */
+	int	ns_es_inhist[NS_ERR_MAX];
+	u_short	ns_es_codes[NS_ERR_MAX];/* which error code for outhist
+					   since we might not know all */
+};
+
+#ifdef _KERNEL
+struct	ns_errstat ns_errstat;
+#endif
diff --git a/sys/netns/ns_if.h b/sys/netns/ns_if.h
new file mode 100644
index 00000000000..6fdea4b3169
--- /dev/null
+++ b/sys/netns/ns_if.h
@@ -0,0 +1,85 @@
+/*	$NetBSD: ns_if.h,v 1.7 1995/06/13 08:37:02 mycroft Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)ns_if.h	8.1 (Berkeley) 6/10/93
+ */
+
+/*
+ * Interface address, xerox version.  One of these structures
+ * is allocated for each interface with an internet address.
+ * The ifaddr structure contains the protocol-independent part
+ * of the structure and is assumed to be first.
+ */
+
+struct ns_ifaddr {
+	struct	ifaddr ia_ifa;		/* protocol-independent info */
+#define	ia_ifp		ia_ifa.ifa_ifp
+#define	ia_flags	ia_ifa.ifa_flags
+	TAILQ_ENTRY(ns_ifaddr) ia_list;	/* list of xerox addresses */
+	struct	sockaddr_ns ia_addr;	/* reserve space for my address */
+	struct	sockaddr_ns ia_dstaddr;	/* space for my broadcast address */
+#define ia_broadaddr	ia_dstaddr
+	struct	sockaddr_ns ia_netmask;	/* space for my network mask */
+};
+
+struct	ns_aliasreq {
+	char	ifra_name[IFNAMSIZ];		/* if name, e.g. "en0" */
+	struct	sockaddr_ns ifra_addr;
+	struct	sockaddr_ns ifra_broadaddr;
+#define ifra_dstaddr ifra_broadaddr
+};
+/*
+ * Given a pointer to an ns_ifaddr (ifaddr),
+ * return a pointer to the addr as a sockadd_ns.
+ */
+
+#define	IA_SNS(ia) (&(((struct ns_ifaddr *)(ia))->ia_addr))
+
+/* This is not the right place for this but where is? */
+#define	ETHERTYPE_NS	0x0600
+
+#ifdef	NSIP
+struct nsip_req {
+	struct sockaddr rq_ns;	/* must be ns format destination */
+	struct sockaddr rq_ip;	/* must be ip format gateway */
+	short rq_flags;
+};
+#endif
+
+#ifdef	_KERNEL
+TAILQ_HEAD(ns_ifaddrhead, ns_ifaddr);
+extern	struct	ns_ifaddrhead ns_ifaddr;
+extern	struct	ifqueue	nsintrq;	/* XNS input packet queue */
+struct	ns_ifaddr *ns_iaonnetof();
+#endif
diff --git a/sys/netns/ns_input.c b/sys/netns/ns_input.c
new file mode 100644
index 00000000000..16927880871
--- /dev/null
+++ b/sys/netns/ns_input.c
@@ -0,0 +1,487 @@
+/*	$NetBSD: ns_input.c,v 1.8 1995/07/27 20:37:27 mycroft Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)ns_input.c	8.1 (Berkeley) 6/10/93
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/domain.h>
+#include <sys/protosw.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/errno.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+
+#include <net/if.h>
+#include <net/route.h>
+#include <net/raw_cb.h>
+
+#include <netns/ns.h>
+#include <netns/ns_if.h>
+#include <netns/ns_pcb.h>
+#include <netns/idp.h>
+#include <netns/idp_var.h>
+#include <netns/ns_error.h>
+
+/*
+ * NS initialization.
+ */
+union ns_host	ns_thishost;
+union ns_host	ns_zerohost;
+union ns_host	ns_broadhost;
+union ns_net	ns_zeronet;
+union ns_net	ns_broadnet;
+struct sockaddr_ns ns_netmask, ns_hostmask;
+
+static u_short allones[] = {-1, -1, -1};
+
+struct nspcb nspcb;
+struct nspcb nsrawpcb;
+
+struct ifqueue	nsintrq;
+int	nsqmaxlen = IFQ_MAXLEN;
+
+int	idpcksum = 1;
+long	ns_pexseq;
+
+ns_init()
+{
+
+	ns_broadhost = * (union ns_host *) allones;
+	ns_broadnet = * (union ns_net *) allones;
+	nspcb.nsp_next = nspcb.nsp_prev = &nspcb;
+	nsrawpcb.nsp_next = nsrawpcb.nsp_prev = &nsrawpcb;
+	nsintrq.ifq_maxlen = nsqmaxlen;
+	TAILQ_INIT(&ns_ifaddr);
+	ns_pexseq = time.tv_usec;
+	ns_netmask.sns_len = 6;
+	ns_netmask.sns_addr.x_net = ns_broadnet;
+	ns_hostmask.sns_len = 12;
+	ns_hostmask.sns_addr.x_net = ns_broadnet;
+	ns_hostmask.sns_addr.x_host = ns_broadhost;
+}
+
+/*
+ * Idp input routine.  Pass to next level.
+ */
+int nsintr_getpck = 0;
+int nsintr_swtch = 0;
+nsintr()
+{
+	register struct idp *idp;
+	register struct mbuf *m;
+	register struct nspcb *nsp;
+	register int i;
+	int len, s, error;
+	char oddpacketp;
+
+next:
+	/*
+	 * Get next datagram off input queue and get IDP header
+	 * in first mbuf.
+	 */
+	s = splimp();
+	IF_DEQUEUE(&nsintrq, m);
+	splx(s);
+	nsintr_getpck++;
+	if (m == 0)
+		return;
+	if ((m->m_flags & M_EXT || m->m_len < sizeof (struct idp)) &&
+	    (m = m_pullup(m, sizeof (struct idp))) == 0) {
+		idpstat.idps_toosmall++;
+		goto next;
+	}
+
+	/*
+	 * Give any raw listeners a crack at the packet
+	 */
+	for (nsp = nsrawpcb.nsp_next; nsp != &nsrawpcb; nsp = nsp->nsp_next) {
+		struct mbuf *m1 = m_copy(m, 0, (int)M_COPYALL);
+		if (m1) idp_input(m1, nsp);
+	}
+
+	idp = mtod(m, struct idp *);
+	len = ntohs(idp->idp_len);
+	if (oddpacketp = len & 1) {
+		len++;		/* If this packet is of odd length,
+				   preserve garbage byte for checksum */
+	}
+
+	/*
+	 * Check that the amount of data in the buffers
+	 * is as at least much as the IDP header would have us expect.
+	 * Trim mbufs if longer than we expect.
+	 * Drop packet if shorter than we expect.
+	 */
+	if (m->m_pkthdr.len < len) {
+		idpstat.idps_tooshort++;
+		goto bad;
+	}
+	if (m->m_pkthdr.len > len) {
+		if (m->m_len == m->m_pkthdr.len) {
+			m->m_len = len;
+			m->m_pkthdr.len = len;
+		} else
+			m_adj(m, len - m->m_pkthdr.len);
+	}
+	if (idpcksum && ((i = idp->idp_sum)!=0xffff)) {
+		idp->idp_sum = 0;
+		if (i != (idp->idp_sum = ns_cksum(m, len))) {
+			idpstat.idps_badsum++;
+			idp->idp_sum = i;
+			if (ns_hosteqnh(ns_thishost, idp->idp_dna.x_host))
+				error = NS_ERR_BADSUM;
+			else
+				error = NS_ERR_BADSUM_T;
+			ns_error(m, error, 0);
+			goto next;
+		}
+	}
+	/*
+	 * Is this a directed broadcast?
+	 */
+	if (ns_hosteqnh(ns_broadhost,idp->idp_dna.x_host)) {
+		if ((!ns_neteq(idp->idp_dna, idp->idp_sna)) &&
+		    (!ns_neteqnn(idp->idp_dna.x_net, ns_broadnet)) &&
+		    (!ns_neteqnn(idp->idp_sna.x_net, ns_zeronet)) &&
+		    (!ns_neteqnn(idp->idp_dna.x_net, ns_zeronet)) ) {
+			/*
+			 * Look to see if I need to eat this packet.
+			 * Algorithm is to forward all young packets
+			 * and prematurely age any packets which will
+			 * by physically broadcasted.
+			 * Any very old packets eaten without forwarding
+			 * would die anyway.
+			 *
+			 * Suggestion of Bill Nesheim, Cornell U.
+			 */
+			if (idp->idp_tc < NS_MAXHOPS) {
+				idp_forward(m);
+				goto next;
+			}
+		}
+	/*
+	 * Is this our packet? If not, forward.
+	 */
+	} else if (!ns_hosteqnh(ns_thishost,idp->idp_dna.x_host)) {
+		idp_forward(m);
+		goto next;
+	}
+	/*
+	 * Locate pcb for datagram.
+	 */
+	nsp = ns_pcblookup(&idp->idp_sna, idp->idp_dna.x_port, NS_WILDCARD);
+	/*
+	 * Switch out to protocol's input routine.
+	 */
+	nsintr_swtch++;
+	if (nsp) {
+		if (oddpacketp) {
+			m_adj(m, -1);
+		}
+		if ((nsp->nsp_flags & NSP_ALL_PACKETS)==0)
+			switch (idp->idp_pt) {
+
+			    case NSPROTO_SPP:
+				    spp_input(m, nsp);
+				    goto next;
+
+			    case NSPROTO_ERROR:
+				    ns_err_input(m);
+				    goto next;
+			}
+		idp_input(m, nsp);
+	} else {
+		ns_error(m, NS_ERR_NOSOCK, 0);
+	}
+	goto next;
+
+bad:
+	m_freem(m);
+	goto next;
+}
+
+u_char nsctlerrmap[PRC_NCMDS] = {
+	ECONNABORTED,	ECONNABORTED,	0,		0,
+	0,		0,		EHOSTDOWN,	EHOSTUNREACH,
+	ENETUNREACH,	EHOSTUNREACH,	ECONNREFUSED,	ECONNREFUSED,
+	EMSGSIZE,	0,		0,		0,
+	0,		0,		0,		0
+};
+
+int idp_donosocks = 1;
+
+idp_ctlinput(cmd, arg)
+	int cmd;
+	caddr_t arg;
+{
+	struct ns_addr *ns;
+	struct nspcb *nsp;
+	struct ns_errp *errp;
+	int idp_abort();
+	extern struct nspcb *idp_drop();
+	int type;
+
+	if (cmd < 0 || cmd > PRC_NCMDS)
+		return;
+	if (nsctlerrmap[cmd] == 0)
+		return;		/* XXX */
+	type = NS_ERR_UNREACH_HOST;
+	switch (cmd) {
+		struct sockaddr_ns *sns;
+
+	case PRC_IFDOWN:
+	case PRC_HOSTDEAD:
+	case PRC_HOSTUNREACH:
+		sns = (struct sockaddr_ns *)arg;
+		if (sns->sns_family != AF_NS)
+			return;
+		ns = &sns->sns_addr;
+		break;
+
+	default:
+		errp = (struct ns_errp *)arg;
+		ns = &errp->ns_err_idp.idp_dna;
+		type = errp->ns_err_num;
+		type = ntohs((u_short)type);
+	}
+	switch (type) {
+
+	case NS_ERR_UNREACH_HOST:
+		ns_pcbnotify(ns, (int)nsctlerrmap[cmd], idp_abort, (long)0);
+		break;
+
+	case NS_ERR_NOSOCK:
+		nsp = ns_pcblookup(ns, errp->ns_err_idp.idp_sna.x_port,
+			NS_WILDCARD);
+		if(nsp && idp_donosocks && ! ns_nullhost(nsp->nsp_faddr))
+			(void) idp_drop(nsp, (int)nsctlerrmap[cmd]);
+	}
+}
+
+int	idpprintfs = 0;
+int	idpforwarding = 1;
+/*
+ * Forward a packet.  If some error occurs return the sender
+ * an error packet.  Note we can't always generate a meaningful
+ * error message because the NS errors don't have a large enough repetoire
+ * of codes and types.
+ */
+struct route idp_droute;
+struct route idp_sroute;
+
+idp_forward(m)
+struct mbuf *m;
+{
+	register struct idp *idp = mtod(m, struct idp *);
+	register int error, type, code;
+	struct mbuf *mcopy = NULL;
+	int agedelta = 1;
+	int flags = NS_FORWARDING;
+	int ok_there = 0;
+	int ok_back = 0;
+
+	if (idpprintfs) {
+		printf("forward: src ");
+		ns_printhost(&idp->idp_sna);
+		printf(", dst ");
+		ns_printhost(&idp->idp_dna);
+		printf("hop count %d\n", idp->idp_tc);
+	}
+	if (idpforwarding == 0) {
+		/* can't tell difference between net and host */
+		type = NS_ERR_UNREACH_HOST, code = 0;
+		goto senderror;
+	}
+	idp->idp_tc++;
+	if (idp->idp_tc > NS_MAXHOPS) {
+		type = NS_ERR_TOO_OLD, code = 0;
+		goto senderror;
+	}
+	/*
+	 * Save at most 42 bytes of the packet in case
+	 * we need to generate an NS error message to the src.
+	 */
+	mcopy = m_copy(m, 0, imin((int)ntohs(idp->idp_len), 42));
+
+	if ((ok_there = idp_do_route(&idp->idp_dna,&idp_droute))==0) {
+		type = NS_ERR_UNREACH_HOST, code = 0;
+		goto senderror;
+	}
+	/*
+	 * Here we think about  forwarding  broadcast packets,
+	 * so we try to insure that it doesn't go back out
+	 * on the interface it came in on.  Also, if we
+	 * are going to physically broadcast this, let us
+	 * age the packet so we can eat it safely the second time around.
+	 */
+	if (idp->idp_dna.x_host.c_host[0] & 0x1) {
+		struct ns_ifaddr *ia = ns_iaonnetof(&idp->idp_dna);
+		struct ifnet *ifp;
+		if (ia) {
+			/* I'm gonna hafta eat this packet */
+			agedelta += NS_MAXHOPS - idp->idp_tc;
+			idp->idp_tc = NS_MAXHOPS;
+		}
+		if ((ok_back = idp_do_route(&idp->idp_sna,&idp_sroute))==0) {
+			/* error = ENETUNREACH; He'll never get it! */
+			m_freem(m);
+			goto cleanup;
+		}
+		if (idp_droute.ro_rt &&
+		    (ifp=idp_droute.ro_rt->rt_ifp) &&
+		    idp_sroute.ro_rt &&
+		    (ifp!=idp_sroute.ro_rt->rt_ifp)) {
+			flags |= NS_ALLOWBROADCAST;
+		} else {
+			type = NS_ERR_UNREACH_HOST, code = 0;
+			goto senderror;
+		}
+	}
+	/* need to adjust checksum */
+	if (idp->idp_sum!=0xffff) {
+		union bytes {
+			u_char c[4];
+			u_short s[2];
+			long l;
+		} x;
+		register int shift;
+		x.l = 0; x.c[0] = agedelta;
+		shift = (((((int)ntohs(idp->idp_len))+1)>>1)-2) & 0xf;
+		x.l = idp->idp_sum + (x.s[0] << shift);
+		x.l = x.s[0] + x.s[1];
+		x.l = x.s[0] + x.s[1];
+		if (x.l==0xffff) idp->idp_sum = 0; else idp->idp_sum = x.l;
+	}
+	if ((error = ns_output(m, &idp_droute, flags)) && 
+	    (mcopy!=NULL)) {
+		idp = mtod(mcopy, struct idp *);
+		type = NS_ERR_UNSPEC_T, code = 0;
+		switch (error) {
+
+		case ENETUNREACH:
+		case EHOSTDOWN:
+		case EHOSTUNREACH:
+		case ENETDOWN:
+		case EPERM:
+			type = NS_ERR_UNREACH_HOST;
+			break;
+
+		case EMSGSIZE:
+			type = NS_ERR_TOO_BIG;
+			code = 576; /* too hard to figure out mtu here */
+			break;
+
+		case ENOBUFS:
+			type = NS_ERR_UNSPEC_T;
+			break;
+		}
+		mcopy = NULL;
+	senderror:
+		ns_error(m, type, code);
+	}
+cleanup:
+	if (ok_there)
+		idp_undo_route(&idp_droute);
+	if (ok_back)
+		idp_undo_route(&idp_sroute);
+	if (mcopy != NULL)
+		m_freem(mcopy);
+}
+
+idp_do_route(src, ro)
+struct ns_addr *src;
+struct route *ro;
+{
+	
+	struct sockaddr_ns *dst;
+
+	bzero((caddr_t)ro, sizeof (*ro));
+	dst = satosns(&ro->ro_dst);
+
+	dst->sns_len = sizeof(*dst);
+	dst->sns_family = AF_NS;
+	dst->sns_addr = *src;
+	dst->sns_addr.x_port = 0;
+	rtalloc(ro);
+	if (ro->ro_rt == 0 || ro->ro_rt->rt_ifp == 0) {
+		return (0);
+	}
+	ro->ro_rt->rt_use++;
+	return (1);
+}
+
+idp_undo_route(ro)
+register struct route *ro;
+{
+	if (ro->ro_rt) {RTFREE(ro->ro_rt);}
+}
+
+ns_watch_output(m, ifp)
+struct mbuf *m;
+struct ifnet *ifp;
+{
+	register struct nspcb *nsp;
+	register struct ifaddr *ifa;
+	/*
+	 * Give any raw listeners a crack at the packet
+	 */
+	for (nsp = nsrawpcb.nsp_next; nsp != &nsrawpcb; nsp = nsp->nsp_next) {
+		struct mbuf *m0 = m_copy(m, 0, (int)M_COPYALL);
+		if (m0) {
+			register struct idp *idp;
+
+			M_PREPEND(m0, sizeof (*idp), M_DONTWAIT);
+			if (m0 == NULL)
+				continue;
+			idp = mtod(m0, struct idp *);
+			idp->idp_sna.x_net = ns_zeronet;
+			idp->idp_sna.x_host = ns_thishost;
+			if (ifp && (ifp->if_flags & IFF_POINTOPOINT))
+				for (ifa = ifp->if_addrlist.tqh_first; ifa != 0;
+				    ifa = ifa->ifa_list.tqe_next) {
+					if (ifa->ifa_addr->sa_family == AF_NS) {
+						idp->idp_sna = IA_SNS(ifa)->sns_addr;
+						break;
+					}
+				}
+			idp->idp_len = ntohl(m0->m_pkthdr.len);
+			idp_input(m0, nsp);
+		}
+	}
+}
diff --git a/sys/netns/ns_ip.c b/sys/netns/ns_ip.c
new file mode 100644
index 00000000000..607ba7b64c3
--- /dev/null
+++ b/sys/netns/ns_ip.c
@@ -0,0 +1,443 @@
+/*	$NetBSD: ns_ip.c,v 1.13 1995/06/13 08:37:05 mycroft Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)ns_ip.c	8.1 (Berkeley) 6/10/93
+ */
+
+/*
+ * Software interface driver for encapsulating ns in ip.
+ */
+
+#ifdef NSIP
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/errno.h>
+#include <sys/ioctl.h>
+#include <sys/protosw.h>
+
+#include <net/if.h>
+#include <net/netisr.h>
+#include <net/route.h>
+
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#include <netinet/in_var.h>
+#include <netinet/ip.h>
+#include <netinet/ip_var.h>
+
+#include <netns/ns.h>
+#include <netns/ns_if.h>
+#include <netns/idp.h>
+
+struct ifnet_en {
+	struct ifnet ifen_ifnet;
+	struct route ifen_route;
+	struct in_addr ifen_src;
+	struct in_addr ifen_dst;
+	struct ifnet_en *ifen_next;
+};
+
+int	nsipoutput(), nsipioctl();
+void	nsipstart();
+#define LOMTU	(1024+512);
+
+struct ifnet nsipif;
+struct ifnet_en *nsip_list;		/* list of all hosts and gateways or
+					broadcast addrs */
+
+struct ifnet_en *
+nsipattach()
+{
+	register struct ifnet_en *m;
+	register struct ifnet *ifp;
+
+	if (nsipif.if_mtu == 0) {
+		ifp = &nsipif;
+		ifp->if_name = "nsip";
+		ifp->if_mtu = LOMTU;
+		ifp->if_ioctl = nsipioctl;
+		ifp->if_output = nsipoutput;
+		ifp->if_start = nsipstart;
+		ifp->if_flags = IFF_POINTOPOINT;
+	}
+
+	MALLOC((m), struct ifnet_en *, sizeof(*m), M_PCB, M_NOWAIT);
+	if (m == NULL) return (NULL);
+	m->ifen_next = nsip_list;
+	nsip_list = m;
+	ifp = &m->ifen_ifnet;
+
+	ifp->if_name = "nsip";
+	ifp->if_mtu = LOMTU;
+	ifp->if_ioctl = nsipioctl;
+	ifp->if_output = nsipoutput;
+	ifp->if_start = nsipstart;
+	ifp->if_flags = IFF_POINTOPOINT;
+	ifp->if_unit = nsipif.if_unit++;
+	if_attach(ifp);
+
+	return (m);
+}
+
+
+/*
+ * Process an ioctl request.
+ */
+/* ARGSUSED */
+nsipioctl(ifp, cmd, data)
+	register struct ifnet *ifp;
+	u_long cmd;
+	caddr_t data;
+{
+	int error = 0;
+	struct ifreq *ifr;
+
+	switch (cmd) {
+
+	case SIOCSIFADDR:
+		ifp->if_flags |= IFF_UP;
+		/* fall into: */
+
+	case SIOCSIFDSTADDR:
+		/*
+		 * Everything else is done at a higher level.
+		 */
+		break;
+
+	case SIOCSIFFLAGS:
+		ifr = (struct ifreq *)data;
+		if ((ifr->ifr_flags & IFF_UP) == 0)
+			error = nsip_free(ifp);
+
+
+	default:
+		error = EINVAL;
+	}
+	return (error);
+}
+
+struct mbuf *nsip_badlen;
+struct mbuf *nsip_lastin;
+int nsip_hold_input;
+
+idpip_input(m, ifp)
+	register struct mbuf *m;
+	struct ifnet *ifp;
+{
+	register struct ip *ip;
+	register struct idp *idp;
+	register struct ifqueue *ifq = &nsintrq;
+	int len, s;
+
+	if (nsip_hold_input) {
+		if (nsip_lastin) {
+			m_freem(nsip_lastin);
+		}
+		nsip_lastin = m_copym(m, 0, (int)M_COPYALL, M_DONTWAIT);
+	}
+	/*
+	 * Get IP and IDP header together in first mbuf.
+	 */
+	nsipif.if_ipackets++;
+	s = sizeof (struct ip) + sizeof (struct idp);
+	if (((m->m_flags & M_EXT) || m->m_len < s) &&
+	    (m = m_pullup(m, s)) == 0) {
+		nsipif.if_ierrors++;
+		return;
+	}
+	ip = mtod(m, struct ip *);
+	if (ip->ip_hl > (sizeof (struct ip) >> 2)) {
+		ip_stripoptions(m, (struct mbuf *)0);
+		if (m->m_len < s) {
+			if ((m = m_pullup(m, s)) == 0) {
+				nsipif.if_ierrors++;
+				return;
+			}
+			ip = mtod(m, struct ip *);
+		}
+	}
+
+	/*
+	 * Make mbuf data length reflect IDP length.
+	 * If not enough data to reflect IDP length, drop.
+	 */
+	m->m_data += sizeof (struct ip);
+	m->m_len -= sizeof (struct ip);
+	m->m_pkthdr.len -= sizeof (struct ip);
+	idp = mtod(m, struct idp *);
+	len = ntohs(idp->idp_len);
+	if (len & 1) len++;		/* Preserve Garbage Byte */
+	if (ip->ip_len != len) {
+		if (len > ip->ip_len) {
+			nsipif.if_ierrors++;
+			if (nsip_badlen) m_freem(nsip_badlen);
+			nsip_badlen = m;
+			return;
+		}
+		/* Any extra will be trimmed off by the NS routines */
+	}
+
+	/*
+	 * Place interface pointer before the data
+	 * for the receiving protocol.
+	 */
+	m->m_pkthdr.rcvif = ifp;
+	/*
+	 * Deliver to NS
+	 */
+	s = splimp();
+	if (IF_QFULL(ifq)) {
+		IF_DROP(ifq);
+bad:
+		m_freem(m);
+		splx(s);
+		return;
+	}
+	IF_ENQUEUE(ifq, m);
+	schednetisr(NETISR_NS);
+	splx(s);
+	return;
+}
+
+/* ARGSUSED */
+nsipoutput(ifn, m, dst)
+	struct ifnet_en *ifn;
+	register struct mbuf *m;
+	struct sockaddr *dst;
+{
+
+	register struct ip *ip;
+	register struct route *ro = &(ifn->ifen_route);
+	register int len = 0;
+	register struct idp *idp = mtod(m, struct idp *);
+	int error;
+
+	ifn->ifen_ifnet.if_opackets++;
+	nsipif.if_opackets++;
+
+
+	/*
+	 * Calculate data length and make space
+	 * for IP header.
+	 */
+	len =  ntohs(idp->idp_len);
+	if (len & 1) len++;		/* Preserve Garbage Byte */
+	/* following clause not necessary on vax */
+	if (3 & (int)m->m_data) {
+		/* force longword alignment of ip hdr */
+		struct mbuf *m0 = m_gethdr(M_DONTWAIT, MT_HEADER);
+		if (m0 == 0) {
+			m_freem(m);
+			return (ENOBUFS);
+		}
+		MH_ALIGN(m0, sizeof (struct ip));
+		m0->m_flags = m->m_flags & M_COPYFLAGS;
+		m0->m_next = m;
+		m0->m_len = sizeof (struct ip);
+		m0->m_pkthdr.len = m0->m_len + m->m_len;
+		m->m_flags &= ~M_PKTHDR;
+	} else {
+		M_PREPEND(m, sizeof (struct ip), M_DONTWAIT);
+		if (m == 0)
+			return (ENOBUFS);
+	}
+	/*
+	 * Fill in IP header.
+	 */
+	ip = mtod(m, struct ip *);
+	*(long *)ip = 0;
+	ip->ip_p = IPPROTO_IDP;
+	ip->ip_src = ifn->ifen_src;
+	ip->ip_dst = ifn->ifen_dst;
+	ip->ip_len = (u_short)len + sizeof (struct ip);
+	ip->ip_ttl = MAXTTL;
+
+	/*
+	 * Output final datagram.
+	 */
+	error =  (ip_output(m, (struct mbuf *)0, ro, SO_BROADCAST, NULL));
+	if (error) {
+		ifn->ifen_ifnet.if_oerrors++;
+		ifn->ifen_ifnet.if_ierrors = error;
+	}
+	return (error);
+bad:
+	m_freem(m);
+	return (ENETUNREACH);
+}
+
+void
+nsipstart(ifp)
+	struct ifnet *ifp;
+{
+	panic("nsip_start called\n");
+}
+
+struct ifreq ifr = {"nsip0"};
+
+nsip_route(m)
+	register struct mbuf *m;
+{
+	register struct nsip_req *rq = mtod(m, struct nsip_req *);
+	struct sockaddr_ns *ns_dst = satosns(&rq->rq_ns);
+	struct sockaddr_in *ip_dst = satosin(&rq->rq_ip);
+	struct route ro;
+	struct ifnet_en *ifn;
+	struct sockaddr_in *src;
+
+	/*
+	 * First, make sure we already have an ns address:
+	 */
+	if (ns_hosteqnh(ns_thishost, ns_zerohost))
+		return (EADDRNOTAVAIL);
+	/*
+	 * Now, determine if we can get to the destination
+	 */
+	bzero((caddr_t)&ro, sizeof (ro));
+	ro.ro_dst = *sintosa(ip_dst);
+	rtalloc(&ro);
+	if (ro.ro_rt == 0 || ro.ro_rt->rt_ifp == 0) {
+		return (ENETUNREACH);
+	}
+
+	/*
+	 * And see how he's going to get back to us:
+	 * i.e., what return ip address do we use?
+	 */
+	{
+		register struct in_ifaddr *ia;
+		struct ifnet *ifp = ro.ro_rt->rt_ifp;
+
+		for (ia = in_ifaddr.tqh_first; ia != 0;
+		    ia = ia->ia_list.tqe_next)
+			if (ia->ia_ifp == ifp)
+				break;
+		if (ia == 0)
+			ia = in_ifaddr;
+		if (ia == 0) {
+			RTFREE(ro.ro_rt);
+			return (EADDRNOTAVAIL);
+		}
+		src = satosin(&ia->ia_addr);
+	}
+
+	/*
+	 * Is there a free (pseudo-)interface or space?
+	 */
+	for (ifn = nsip_list; ifn; ifn = ifn->ifen_next) {
+		if ((ifn->ifen_ifnet.if_flags & IFF_UP) == 0)
+			break;
+	}
+	if (ifn == NULL)
+		ifn = nsipattach();
+	if (ifn == NULL) {
+		RTFREE(ro.ro_rt);
+		return (ENOBUFS);
+	}
+	ifn->ifen_route = ro;
+	ifn->ifen_dst =  ip_dst->sin_addr;
+	ifn->ifen_src = src->sin_addr;
+
+	/*
+	 * now configure this as a point to point link
+	 */
+	ifr.ifr_name[4] = '0' + nsipif.if_unit - 1;
+	ifr.ifr_dstaddr = *snstosa(ns_dst);
+	(void)ns_control((struct socket *)0, SIOCSIFDSTADDR, (caddr_t)&ifr,
+			(struct ifnet *)ifn);
+	satons_addr(ifr.ifr_addr).x_host = ns_thishost;
+	return (ns_control((struct socket *)0, SIOCSIFADDR, (caddr_t)&ifr,
+			(struct ifnet *)ifn));
+}
+
+nsip_free(ifp)
+struct ifnet *ifp;
+{
+	register struct ifnet_en *ifn = (struct ifnet_en *)ifp;
+	struct route *ro = & ifn->ifen_route;
+
+	if (ro->ro_rt) {
+		RTFREE(ro->ro_rt);
+		ro->ro_rt = 0;
+	}
+	ifp->if_flags &= ~IFF_UP;
+	return (0);
+}
+
+nsip_ctlinput(cmd, sa)
+	int cmd;
+	struct sockaddr *sa;
+{
+	extern u_char inetctlerrmap[];
+	struct sockaddr_in *sin;
+	int in_rtchange();
+
+	if ((unsigned)cmd >= PRC_NCMDS)
+		return;
+	if (sa->sa_family != AF_INET && sa->sa_family != AF_IMPLINK)
+		return;
+	sin = satosin(sa);
+	if (sin->sin_addr.s_addr == INADDR_ANY)
+		return;
+
+	switch (cmd) {
+
+	case PRC_ROUTEDEAD:
+	case PRC_REDIRECT_NET:
+	case PRC_REDIRECT_HOST:
+	case PRC_REDIRECT_TOSNET:
+	case PRC_REDIRECT_TOSHOST:
+		nsip_rtchange(&sin->sin_addr);
+		break;
+	}
+}
+
+nsip_rtchange(dst)
+	register struct in_addr *dst;
+{
+	register struct ifnet_en *ifn;
+
+	for (ifn = nsip_list; ifn; ifn = ifn->ifen_next) {
+		if (ifn->ifen_dst.s_addr == dst->s_addr &&
+			ifn->ifen_route.ro_rt) {
+				RTFREE(ifn->ifen_route.ro_rt);
+				ifn->ifen_route.ro_rt = 0;
+		}
+	}
+}
+#endif
diff --git a/sys/netns/ns_output.c b/sys/netns/ns_output.c
new file mode 100644
index 00000000000..4fc7320475d
--- /dev/null
+++ b/sys/netns/ns_output.c
@@ -0,0 +1,158 @@
+/*	$NetBSD: ns_output.c,v 1.7 1995/06/13 08:37:07 mycroft Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)ns_output.c	8.1 (Berkeley) 6/10/93
+ */
+
+#include <sys/param.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/errno.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+
+#include <net/if.h>
+#include <net/route.h>
+
+#include <netns/ns.h>
+#include <netns/ns_if.h>
+#include <netns/idp.h>
+#include <netns/idp_var.h>
+
+int ns_hold_output = 0;
+int ns_copy_output = 0;
+int ns_output_cnt = 0;
+struct mbuf *ns_lastout;
+
+ns_output(m0, ro, flags)
+	struct mbuf *m0;
+	struct route *ro;
+	int flags;
+{
+	register struct idp *idp = mtod(m0, struct idp *);
+	register struct ifnet *ifp = 0;
+	int error = 0;
+	struct route idproute;
+	struct sockaddr_ns *dst;
+	extern int idpcksum;
+
+	if (ns_hold_output) {
+		if (ns_lastout) {
+			(void)m_free(ns_lastout);
+		}
+		ns_lastout = m_copy(m0, 0, (int)M_COPYALL);
+	}
+	/*
+	 * Route packet.
+	 */
+	if (ro == 0) {
+		ro = &idproute;
+		bzero((caddr_t)ro, sizeof (*ro));
+	}
+	dst = satosns(&ro->ro_dst);
+	if (ro->ro_rt == 0) {
+		dst->sns_family = AF_NS;
+		dst->sns_len = sizeof (*dst);
+		dst->sns_addr = idp->idp_dna;
+		dst->sns_addr.x_port = 0;
+		/*
+		 * If routing to interface only,
+		 * short circuit routing lookup.
+		 */
+		if (flags & NS_ROUTETOIF) {
+			struct ns_ifaddr *ia = ns_iaonnetof(&idp->idp_dna);
+
+			if (ia == 0) {
+				error = ENETUNREACH;
+				goto bad;
+			}
+			ifp = ia->ia_ifp;
+			goto gotif;
+		}
+		rtalloc(ro);
+	} else if ((ro->ro_rt->rt_flags & RTF_UP) == 0) {
+		/*
+		 * The old route has gone away; try for a new one.
+		 */
+		rtfree(ro->ro_rt);
+		ro->ro_rt = NULL;
+		rtalloc(ro);
+	}
+	if (ro->ro_rt == 0 || (ifp = ro->ro_rt->rt_ifp) == 0) {
+		error = ENETUNREACH;
+		goto bad;
+	}
+	ro->ro_rt->rt_use++;
+	if (ro->ro_rt->rt_flags & (RTF_GATEWAY|RTF_HOST))
+		dst = satosns(ro->ro_rt->rt_gateway);
+gotif:
+
+	/*
+	 * Look for multicast addresses and
+	 * and verify user is allowed to send
+	 * such a packet.
+	 */
+	if (dst->sns_addr.x_host.c_host[0]&1) {
+		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
+			error = EADDRNOTAVAIL;
+			goto bad;
+		}
+		if ((flags & NS_ALLOWBROADCAST) == 0) {
+			error = EACCES;
+			goto bad;
+		}
+	}
+
+	if (htons(idp->idp_len) <= ifp->if_mtu) {
+		ns_output_cnt++;
+		if (ns_copy_output) {
+			ns_watch_output(m0, ifp);
+		}
+		error = (*ifp->if_output)(ifp, m0, snstosa(dst), ro->ro_rt);
+		goto done;
+	} else error = EMSGSIZE;
+
+
+bad:
+	if (ns_copy_output) {
+		ns_watch_output(m0, ifp);
+	}
+	m_freem(m0);
+done:
+	if (ro == &idproute && (flags & NS_ROUTETOIF) == 0 && ro->ro_rt) {
+		RTFREE(ro->ro_rt);
+		ro->ro_rt = 0;
+	}
+	return (error);
+}
diff --git a/sys/netns/ns_pcb.c b/sys/netns/ns_pcb.c
new file mode 100644
index 00000000000..d8435ca46b9
--- /dev/null
+++ b/sys/netns/ns_pcb.c
@@ -0,0 +1,365 @@
+/*	$NetBSD: ns_pcb.c,v 1.8 1995/08/17 02:57:38 mycroft Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)ns_pcb.c	8.1 (Berkeley) 6/10/93
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/mbuf.h>
+#include <sys/errno.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/protosw.h>
+
+#include <net/if.h>
+#include <net/route.h>
+
+#include <netns/ns.h>
+#include <netns/ns_if.h>
+#include <netns/ns_pcb.h>
+
+struct	ns_addr zerons_addr;
+
+ns_pcballoc(so, head)
+	struct socket *so;
+	struct nspcb *head;
+{
+	register struct nspcb *nsp;
+
+	nsp = malloc(sizeof(*nsp), M_PCB, M_NOWAIT);
+	if (nsp == 0)
+		return (ENOBUFS);
+	bzero((caddr_t)nsp, sizeof(*nsp));
+	nsp->nsp_socket = so;
+	insque(nsp, head);
+	so->so_pcb = nsp;
+	return (0);
+}
+	
+ns_pcbbind(nsp, nam)
+	register struct nspcb *nsp;
+	struct mbuf *nam;
+{
+	register struct sockaddr_ns *sns;
+	u_short lport = 0;
+
+	if (nsp->nsp_lport || !ns_nullhost(nsp->nsp_laddr))
+		return (EINVAL);
+	if (nam == 0)
+		goto noname;
+	sns = mtod(nam, struct sockaddr_ns *);
+	if (nam->m_len != sizeof (*sns))
+		return (EINVAL);
+	if (!ns_nullhost(sns->sns_addr)) {
+		int tport = sns->sns_port;
+
+		sns->sns_port = 0;		/* yech... */
+		if (ifa_ifwithaddr(snstosa(sns)) == 0)
+			return (EADDRNOTAVAIL);
+		sns->sns_port = tport;
+	}
+	lport = sns->sns_port;
+	if (lport) {
+		u_short aport = ntohs(lport);
+
+		if (aport < NSPORT_RESERVED &&
+		    (nsp->nsp_socket->so_state & SS_PRIV) == 0)
+			return (EACCES);
+		if (ns_pcblookup(&zerons_addr, lport, 0))
+			return (EADDRINUSE);
+	}
+	nsp->nsp_laddr = sns->sns_addr;
+noname:
+	if (lport == 0)
+		do {
+			if (nspcb.nsp_lport++ < NSPORT_RESERVED)
+				nspcb.nsp_lport = NSPORT_RESERVED;
+			lport = htons(nspcb.nsp_lport);
+		} while (ns_pcblookup(&zerons_addr, lport, 0));
+	nsp->nsp_lport = lport;
+	return (0);
+}
+
+/*
+ * Connect from a socket to a specified address.
+ * Both address and port must be specified in argument sns.
+ * If don't have a local address for this socket yet,
+ * then pick one.
+ */
+ns_pcbconnect(nsp, nam)
+	struct nspcb *nsp;
+	struct mbuf *nam;
+{
+	struct ns_ifaddr *ia;
+	register struct sockaddr_ns *sns = mtod(nam, struct sockaddr_ns *);
+	register struct ns_addr *dst;
+	register struct route *ro;
+	struct ifnet *ifp;
+
+	if (nam->m_len != sizeof (*sns))
+		return (EINVAL);
+	if (sns->sns_family != AF_NS)
+		return (EAFNOSUPPORT);
+	if (sns->sns_port==0 || ns_nullhost(sns->sns_addr))
+		return (EADDRNOTAVAIL);
+	/*
+	 * If we haven't bound which network number to use as ours,
+	 * we will use the number of the outgoing interface.
+	 * This depends on having done a routing lookup, which
+	 * we will probably have to do anyway, so we might
+	 * as well do it now.  On the other hand if we are
+	 * sending to multiple destinations we may have already
+	 * done the lookup, so see if we can use the route
+	 * from before.  In any case, we only
+	 * chose a port number once, even if sending to multiple
+	 * destinations.
+	 */
+	ro = &nsp->nsp_route;
+	dst = &satons_addr(ro->ro_dst);
+	if (nsp->nsp_socket->so_options & SO_DONTROUTE)
+		goto flush;
+	if (!ns_neteq(nsp->nsp_lastdst, sns->sns_addr))
+		goto flush;
+	if (!ns_hosteq(nsp->nsp_lastdst, sns->sns_addr)) {
+		if (ro->ro_rt && ! (ro->ro_rt->rt_flags & RTF_HOST)) {
+			/* can patch route to avoid rtalloc */
+			*dst = sns->sns_addr;
+		} else {
+	flush:
+			if (ro->ro_rt)
+				RTFREE(ro->ro_rt);
+			ro->ro_rt = (struct rtentry *)0;
+			nsp->nsp_laddr.x_net = ns_zeronet;
+		}
+	}/* else cached route is ok; do nothing */
+	nsp->nsp_lastdst = sns->sns_addr;
+	if ((nsp->nsp_socket->so_options & SO_DONTROUTE) == 0 && /*XXX*/
+	    (ro->ro_rt == (struct rtentry *)0 ||
+	     ro->ro_rt->rt_ifp == (struct ifnet *)0)) {
+		    /* No route yet, so try to acquire one */
+		    ro->ro_dst.sa_family = AF_NS;
+		    ro->ro_dst.sa_len = sizeof(ro->ro_dst);
+		    *dst = sns->sns_addr;
+		    dst->x_port = 0;
+		    rtalloc(ro);
+	}
+	if (ns_neteqnn(nsp->nsp_laddr.x_net, ns_zeronet)) {
+		/* 
+		 * If route is known or can be allocated now,
+		 * our src addr is taken from the i/f, else punt.
+		 */
+
+		ia = 0;
+		/*
+		 * If we found a route, use the address
+		 * corresponding to the outgoing interface
+		 */
+		if (ro->ro_rt && (ifp = ro->ro_rt->rt_ifp))
+			for (ia = ns_ifaddr.tqh_first; ia != 0;
+			    ia = ia->ia_list.tqe_next)
+				if (ia->ia_ifp == ifp)
+					break;
+		if (ia == 0) {
+			u_short fport = sns->sns_addr.x_port;
+			sns->sns_addr.x_port = 0;
+			ia = (struct ns_ifaddr *)
+				ifa_ifwithdstaddr(snstosa(sns));
+			sns->sns_addr.x_port = fport;
+			if (ia == 0)
+				ia = ns_iaonnetof(&sns->sns_addr);
+			if (ia == 0)
+				ia = ns_ifaddr.tqh_first;
+			if (ia == 0)
+				return (EADDRNOTAVAIL);
+		}
+		nsp->nsp_laddr.x_net = satons_addr(ia->ia_addr).x_net;
+	}
+	if (ns_pcblookup(&sns->sns_addr, nsp->nsp_lport, 0))
+		return (EADDRINUSE);
+	if (ns_nullhost(nsp->nsp_laddr)) {
+		if (nsp->nsp_lport == 0)
+			(void) ns_pcbbind(nsp, (struct mbuf *)0);
+		nsp->nsp_laddr.x_host = ns_thishost;
+	}
+	nsp->nsp_faddr = sns->sns_addr;
+	/* Includes nsp->nsp_fport = sns->sns_port; */
+	return (0);
+}
+
+ns_pcbdisconnect(nsp)
+	struct nspcb *nsp;
+{
+
+	nsp->nsp_faddr = zerons_addr;
+	if (nsp->nsp_socket->so_state & SS_NOFDREF)
+		ns_pcbdetach(nsp);
+}
+
+ns_pcbdetach(nsp)
+	struct nspcb *nsp;
+{
+	struct socket *so = nsp->nsp_socket;
+
+	so->so_pcb = 0;
+	sofree(so);
+	if (nsp->nsp_route.ro_rt)
+		rtfree(nsp->nsp_route.ro_rt);
+	remque(nsp);
+	free(nsp, M_PCB);
+}
+
+ns_setsockaddr(nsp, nam)
+	register struct nspcb *nsp;
+	struct mbuf *nam;
+{
+	register struct sockaddr_ns *sns = mtod(nam, struct sockaddr_ns *);
+	
+	nam->m_len = sizeof (*sns);
+	sns = mtod(nam, struct sockaddr_ns *);
+	bzero((caddr_t)sns, sizeof (*sns));
+	sns->sns_len = sizeof(*sns);
+	sns->sns_family = AF_NS;
+	sns->sns_addr = nsp->nsp_laddr;
+}
+
+ns_setpeeraddr(nsp, nam)
+	register struct nspcb *nsp;
+	struct mbuf *nam;
+{
+	register struct sockaddr_ns *sns = mtod(nam, struct sockaddr_ns *);
+	
+	nam->m_len = sizeof (*sns);
+	sns = mtod(nam, struct sockaddr_ns *);
+	bzero((caddr_t)sns, sizeof (*sns));
+	sns->sns_len = sizeof(*sns);
+	sns->sns_family = AF_NS;
+	sns->sns_addr  = nsp->nsp_faddr;
+}
+
+/*
+ * Pass some notification to all connections of a protocol
+ * associated with address dst.  Call the
+ * protocol specific routine to handle each connection.
+ * Also pass an extra paramter via the nspcb. (which may in fact
+ * be a parameter list!)
+ */
+ns_pcbnotify(dst, errno, notify, param)
+	register struct ns_addr *dst;
+	long param;
+	int errno, (*notify)();
+{
+	register struct nspcb *nsp, *oinp;
+	int s = splimp();
+
+	for (nsp = (&nspcb)->nsp_next; nsp != (&nspcb);) {
+		if (!ns_hosteq(*dst,nsp->nsp_faddr)) {
+	next:
+			nsp = nsp->nsp_next;
+			continue;
+		}
+		if (nsp->nsp_socket == 0)
+			goto next;
+		if (errno) 
+			nsp->nsp_socket->so_error = errno;
+		oinp = nsp;
+		nsp = nsp->nsp_next;
+		oinp->nsp_notify_param = param;
+		(*notify)(oinp);
+	}
+	splx(s);
+}
+
+#ifdef notdef
+/*
+ * After a routing change, flush old routing
+ * and allocate a (hopefully) better one.
+ */
+ns_rtchange(nsp)
+	struct nspcb *nsp;
+{
+	if (nsp->nsp_route.ro_rt) {
+		rtfree(nsp->nsp_route.ro_rt);
+		nsp->nsp_route.ro_rt = 0;
+		/*
+		 * A new route can be allocated the next time
+		 * output is attempted.
+		 */
+	}
+	/* SHOULD NOTIFY HIGHER-LEVEL PROTOCOLS */
+}
+#endif
+
+struct nspcb *
+ns_pcblookup(faddr, lport, wildp)
+	struct ns_addr *faddr;
+	u_short lport;
+{
+	register struct nspcb *nsp, *match = 0;
+	int matchwild = 3, wildcard;
+	u_short fport;
+
+	fport = faddr->x_port;
+	for (nsp = (&nspcb)->nsp_next; nsp != (&nspcb); nsp = nsp->nsp_next) {
+		if (nsp->nsp_lport != lport)
+			continue;
+		wildcard = 0;
+		if (ns_nullhost(nsp->nsp_faddr)) {
+			if (!ns_nullhost(*faddr))
+				wildcard++;
+		} else {
+			if (ns_nullhost(*faddr))
+				wildcard++;
+			else {
+				if (!ns_hosteq(nsp->nsp_faddr, *faddr))
+					continue;
+				if (nsp->nsp_fport != fport) {
+					if (nsp->nsp_fport != 0)
+						continue;
+					else
+						wildcard++;
+				}
+			}
+		}
+		if (wildcard && wildp==0)
+			continue;
+		if (wildcard < matchwild) {
+			match = nsp;
+			matchwild = wildcard;
+			if (wildcard == 0)
+				break;
+		}
+	}
+	return (match);
+}
diff --git a/sys/netns/ns_pcb.h b/sys/netns/ns_pcb.h
new file mode 100644
index 00000000000..eca3d14817c
--- /dev/null
+++ b/sys/netns/ns_pcb.h
@@ -0,0 +1,82 @@
+/*	$NetBSD: ns_pcb.h,v 1.6 1995/03/26 20:36:21 jtc Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)ns_pcb.h	8.1 (Berkeley) 6/10/93
+ */
+
+/*
+ * Ns protocol interface control block.
+ */
+struct nspcb {
+	struct	nspcb *nsp_next;	/* doubly linked list */
+	struct	nspcb *nsp_prev;
+	struct	nspcb *nsp_head;
+	struct	socket *nsp_socket;	/* back pointer to socket */
+	struct	ns_addr nsp_faddr;	/* destination address */
+	struct	ns_addr nsp_laddr;	/* socket's address */
+	caddr_t	nsp_pcb;		/* protocol specific stuff */
+	struct	route nsp_route;	/* routing information */
+	struct	ns_addr nsp_lastdst;	/* validate cached route for dg socks*/
+	long	nsp_notify_param;	/* extra info passed via ns_pcbnotify*/
+	short	nsp_flags;
+	u_char	nsp_dpt;		/* default packet type for idp_output*/
+	u_char	nsp_rpt;		/* last received packet type by
+								idp_input() */
+};
+
+/* possible flags */
+
+#define NSP_IN_ABORT	0x1		/* calling abort through socket */
+#define NSP_RAWIN	0x2		/* show headers on input */
+#define NSP_RAWOUT	0x4		/* show header on output */
+#define NSP_ALL_PACKETS	0x8		/* Turn off higher proto processing */
+
+#define	NS_WILDCARD	1
+
+#define nsp_lport nsp_laddr.x_port
+#define nsp_fport nsp_faddr.x_port
+
+#define	sotonspcb(so)		((struct nspcb *)((so)->so_pcb))
+
+/*
+ * Nominal space allocated to a ns socket.
+ */
+#define	NSSNDQ		2048
+#define	NSRCVQ		2048
+
+
+#ifdef _KERNEL
+struct	nspcb nspcb;			/* head of list */
+struct	nspcb *ns_pcblookup();
+#endif
diff --git a/sys/netns/ns_proto.c b/sys/netns/ns_proto.c
new file mode 100644
index 00000000000..7ecbdf60093
--- /dev/null
+++ b/sys/netns/ns_proto.c
@@ -0,0 +1,99 @@
+/*	$NetBSD: ns_proto.c,v 1.5 1994/06/29 06:41:48 cgd Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)ns_proto.c	8.1 (Berkeley) 6/10/93
+ */
+
+#include <sys/param.h>
+#include <sys/socket.h>
+#include <sys/protosw.h>
+#include <sys/domain.h>
+#include <sys/mbuf.h>
+
+#include <net/radix.h>
+
+#include <netns/ns.h>
+
+/*
+ * NS protocol family: IDP, ERR, PE, SPP, ROUTE.
+ */
+void	ns_init();
+int	idp_output(), idp_usrreq();
+void	idp_input(), idp_ctlinput();
+int	idp_raw_usrreq(), idp_ctloutput();
+void	spp_input(), spp_ctlinput();
+int	spp_usrreq(), spp_usrreq_sp(), spp_ctloutput();
+void	spp_init(), spp_fasttimo(), spp_slowtimo();
+int	raw_usrreq();
+
+extern	struct domain nsdomain;
+
+struct protosw nssw[] = {
+{ 0,		&nsdomain,	0,		0,
+  0,		idp_output,	0,		0,
+  0,
+  ns_init,	0,		0,		0,
+},
+{ SOCK_DGRAM,	&nsdomain,	0,		PR_ATOMIC|PR_ADDR,
+  0,		0,		idp_ctlinput,	idp_ctloutput,
+  idp_usrreq,
+  0,		0,		0,		0,
+},
+{ SOCK_STREAM,	&nsdomain,	NSPROTO_SPP,	PR_CONNREQUIRED|PR_WANTRCVD,
+  spp_input,	0,		spp_ctlinput,	spp_ctloutput,
+  spp_usrreq,
+  spp_init,	spp_fasttimo,	spp_slowtimo,	0,
+},
+{ SOCK_SEQPACKET,&nsdomain,	NSPROTO_SPP,	PR_CONNREQUIRED|PR_WANTRCVD|PR_ATOMIC,
+  spp_input,	0,		spp_ctlinput,	spp_ctloutput,
+  spp_usrreq_sp,
+  0,		0,		0,		0,
+},
+{ SOCK_RAW,	&nsdomain,	NSPROTO_RAW,	PR_ATOMIC|PR_ADDR,
+  idp_input,	idp_output,	0,		idp_ctloutput,
+  idp_raw_usrreq,
+  0,		0,		0,		0,
+},
+{ SOCK_RAW,	&nsdomain,	NSPROTO_ERROR,	PR_ATOMIC|PR_ADDR,
+  idp_ctlinput,	idp_output,	0,		idp_ctloutput,
+  idp_raw_usrreq,
+  0,		0,		0,		0,
+},
+};
+
+struct domain nsdomain =
+    { AF_NS, "network systems", 0, 0, 0, 
+      nssw, &nssw[sizeof(nssw)/sizeof(nssw[0])], 0,
+      rn_inithead, 16, sizeof(struct sockaddr_ns)};
+
diff --git a/sys/netns/sp.h b/sys/netns/sp.h
new file mode 100644
index 00000000000..31fedf7c97c
--- /dev/null
+++ b/sys/netns/sp.h
@@ -0,0 +1,54 @@
+/*	$NetBSD: sp.h,v 1.5 1994/06/29 06:41:50 cgd Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)sp.h	8.1 (Berkeley) 6/10/93
+ */
+
+/*
+ * Definitions for Xerox NS style sequenced packet protocol
+ */
+
+struct sphdr {
+	u_char	sp_cc;		/* connection control */
+	u_char	sp_dt;		/* datastream type */
+#define	SP_SP	0x80		/* system packet */
+#define	SP_SA	0x40		/* send acknowledgement */
+#define	SP_OB	0x20		/* attention (out of band data) */
+#define	SP_EM	0x10		/* end of message */
+	u_short	sp_sid;		/* source connection identifier */
+	u_short	sp_did;		/* destination connection identifier */
+	u_short	sp_seq;		/* sequence number */
+	u_short	sp_ack;		/* acknowledge number */
+	u_short	sp_alo;		/* allocation number */
+};
diff --git a/sys/netns/spidp.h b/sys/netns/spidp.h
new file mode 100644
index 00000000000..202d2fe3893
--- /dev/null
+++ b/sys/netns/spidp.h
@@ -0,0 +1,64 @@
+/*	$NetBSD: spidp.h,v 1.5 1994/06/29 06:41:52 cgd Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)spidp.h	8.1 (Berkeley) 6/10/93
+ */
+
+/*
+ * Definitions for NS(tm) Internet Datagram Protocol
+ * containing a Sequenced Packet Protocol packet.
+ */
+struct spidp {
+	struct idp	si_i;
+	struct sphdr 	si_s;
+};
+struct spidp_q {
+	struct spidp_q	*si_next;
+	struct spidp_q	*si_prev;
+};
+#define SI(x)	((struct spidp *)x)
+#define si_sum	si_i.idp_sum
+#define si_len	si_i.idp_len
+#define si_tc	si_i.idp_tc
+#define si_pt	si_i.idp_pt
+#define si_dna	si_i.idp_dna
+#define si_sna	si_i.idp_sna
+#define si_sport	si_i.idp_sna.x_port
+#define si_cc	si_s.sp_cc
+#define si_dt	si_s.sp_dt
+#define si_sid	si_s.sp_sid
+#define si_did	si_s.sp_did
+#define si_seq	si_s.sp_seq
+#define si_ack	si_s.sp_ack
+#define si_alo	si_s.sp_alo
diff --git a/sys/netns/spp_debug.c b/sys/netns/spp_debug.c
new file mode 100644
index 00000000000..cbb9aec7135
--- /dev/null
+++ b/sys/netns/spp_debug.c
@@ -0,0 +1,172 @@
+/*	$NetBSD: spp_debug.c,v 1.5 1994/06/29 06:41:53 cgd Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)spp_debug.c	8.1 (Berkeley) 6/10/93
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/protosw.h>
+#include <sys/errno.h>
+
+#include <net/route.h>
+#include <net/if.h>
+#include <netinet/tcp_fsm.h>
+
+#include <netns/ns.h>
+#include <netns/ns_pcb.h>
+#include <netns/idp.h>
+#include <netns/idp_var.h>
+#include <netns/sp.h>
+#include <netns/spidp.h>
+#define SPPTIMERS
+#include <netns/spp_timer.h>
+#include <netns/spp_var.h>
+#define	SANAMES
+#include <netns/spp_debug.h>
+
+int	sppconsdebug = 0;
+/*
+ * spp debug routines
+ */
+spp_trace(act, ostate, sp, si, req)
+	short act;
+	u_char ostate;
+	struct sppcb *sp;
+	struct spidp *si;
+	int req;
+{
+#ifdef INET
+#ifdef TCPDEBUG
+	u_short seq, ack, len, alo;
+	unsigned long iptime();
+	int flags;
+	struct spp_debug *sd = &spp_debug[spp_debx++];
+	extern char *prurequests[];
+	extern char *sanames[];
+	extern char *tcpstates[];
+	extern char *spptimers[];
+
+	if (spp_debx == SPP_NDEBUG)
+		spp_debx = 0;
+	sd->sd_time = iptime();
+	sd->sd_act = act;
+	sd->sd_ostate = ostate;
+	sd->sd_cb = (caddr_t)sp;
+	if (sp)
+		sd->sd_sp = *sp;
+	else
+		bzero((caddr_t)&sd->sd_sp, sizeof (*sp));
+	if (si)
+		sd->sd_si = *si;
+	else
+		bzero((caddr_t)&sd->sd_si, sizeof (*si));
+	sd->sd_req = req;
+	if (sppconsdebug == 0)
+		return;
+	if (ostate >= TCP_NSTATES) ostate = 0;
+	if (act >= SA_DROP) act = SA_DROP;
+	if (sp)
+		printf("%x %s:", sp, tcpstates[ostate]);
+	else
+		printf("???????? ");
+	printf("%s ", sanames[act]);
+	switch (act) {
+
+	case SA_RESPOND:
+	case SA_INPUT:
+	case SA_OUTPUT:
+	case SA_DROP:
+		if (si == 0)
+			break;
+		seq = si->si_seq;
+		ack = si->si_ack;
+		alo = si->si_alo;
+		len = si->si_len;
+		if (act == SA_OUTPUT) {
+			seq = ntohs(seq);
+			ack = ntohs(ack);
+			alo = ntohs(alo);
+			len = ntohs(len);
+		}
+#ifndef lint
+#define p1(f)  { printf("%s = %x, ", "f", f); }
+		p1(seq); p1(ack); p1(alo); p1(len);
+#endif
+		flags = si->si_cc;
+		if (flags) {
+			char *cp = "<";
+#ifndef lint
+#define pf(f) { if (flags&SP_/**/f) { printf("%s%s", cp, "f"); cp = ","; } }
+			pf(SP); pf(SA); pf(OB); pf(EM);
+#else
+			cp = cp;
+#endif
+			printf(">");
+		}
+#ifndef lint
+#define p2(f)  { printf("%s = %x, ", "f", si->si_/**/f); }
+		p2(sid);p2(did);p2(dt);p2(pt);
+#endif
+		ns_printhost(&si->si_sna);
+		ns_printhost(&si->si_dna);
+
+		if (act==SA_RESPOND) {
+			printf("idp_len = %x, ",
+				((struct idp *)si)->idp_len);
+		}
+		break;
+
+	case SA_USER:
+		printf("%s", prurequests[req&0xff]);
+		if ((req & 0xff) == PRU_SLOWTIMO)
+			printf("<%s>", spptimers[req>>8]);
+		break;
+	}
+	if (sp)
+		printf(" -> %s", tcpstates[sp->s_state]);
+	/* print out internal state of sp !?! */
+	printf("\n");
+	if (sp == 0)
+		return;
+#ifndef lint
+#define p3(f)  { printf("%s = %x, ", "f", sp->s_/**/f); }
+	printf("\t"); p3(rack);p3(ralo);p3(smax);p3(flags); printf("\n");
+#endif
+#endif
+#endif
+}
diff --git a/sys/netns/spp_debug.h b/sys/netns/spp_debug.h
new file mode 100644
index 00000000000..f13c5216ac7
--- /dev/null
+++ b/sys/netns/spp_debug.h
@@ -0,0 +1,61 @@
+/*	$NetBSD: spp_debug.h,v 1.5 1994/06/29 06:41:54 cgd Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)spp_debug.h	8.1 (Berkeley) 6/10/93
+ */
+
+struct	spp_debug {
+	u_long	sd_time;
+	short	sd_act;
+	short	sd_ostate;
+	caddr_t	sd_cb;
+	short	sd_req;
+	struct	spidp sd_si;
+	struct	sppcb sd_sp;
+};
+
+#define	SA_INPUT 	0
+#define	SA_OUTPUT	1
+#define	SA_USER		2
+#define	SA_RESPOND	3
+#define	SA_DROP		4
+
+#ifdef SANAMES
+char	*sanames[] =
+    { "input", "output", "user", "respond", "drop" };
+#endif
+
+#define	SPP_NDEBUG 100
+struct	spp_debug spp_debug[SPP_NDEBUG];
+int	spp_debx;
diff --git a/sys/netns/spp_timer.h b/sys/netns/spp_timer.h
new file mode 100644
index 00000000000..533c555e396
--- /dev/null
+++ b/sys/netns/spp_timer.h
@@ -0,0 +1,124 @@
+/*	$NetBSD: spp_timer.h,v 1.6 1995/03/26 20:36:22 jtc 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.
+ *
+ *	@(#)spp_timer.h	8.1 (Berkeley) 6/10/93
+ */
+
+/*
+ * Definitions of the SPP timers.  These timers are counted
+ * down PR_SLOWHZ times a second.
+ */
+#define	SPPT_NTIMERS	4
+
+#define	SPPT_REXMT	0		/* retransmit */
+#define	SPPT_PERSIST	1		/* retransmit persistance */
+#define	SPPT_KEEP	2		/* keep alive */
+#define	SPPT_2MSL	3		/* 2*msl quiet time timer */
+
+/*
+ * The SPPT_REXMT timer is used to force retransmissions.
+ * The SPP has the SPPT_REXMT timer set whenever segments
+ * have been sent for which ACKs are expected but not yet
+ * received.  If an ACK is received which advances tp->snd_una,
+ * then the retransmit timer is cleared (if there are no more
+ * outstanding segments) or reset to the base value (if there
+ * are more ACKs expected).  Whenever the retransmit timer goes off,
+ * we retransmit one unacknowledged segment, and do a backoff
+ * on the retransmit timer.
+ *
+ * The SPPT_PERSIST timer is used to keep window size information
+ * flowing even if the window goes shut.  If all previous transmissions
+ * have been acknowledged (so that there are no retransmissions in progress),
+ * and the window is too small to bother sending anything, then we start
+ * the SPPT_PERSIST timer.  When it expires, if the window is nonzero,
+ * we go to transmit state.  Otherwise, at intervals send a single byte
+ * into the peer's window to force him to update our window information.
+ * We do this at most as often as SPPT_PERSMIN time intervals,
+ * but no more frequently than the current estimate of round-trip
+ * packet time.  The SPPT_PERSIST timer is cleared whenever we receive
+ * a window update from the peer.
+ *
+ * The SPPT_KEEP timer is used to keep connections alive.  If an
+ * connection is idle (no segments received) for SPPTV_KEEP amount of time,
+ * but not yet established, then we drop the connection.  If the connection
+ * is established, then we force the peer to send us a segment by sending:
+ *	<SEQ=SND.UNA-1><ACK=RCV.NXT><CTL=ACK>
+ * This segment is (deliberately) outside the window, and should elicit
+ * an ack segment in response from the peer.  If, despite the SPPT_KEEP
+ * initiated segments we cannot elicit a response from a peer in SPPT_MAXIDLE
+ * amount of time, then we drop the connection.
+ */
+
+#define	SPP_TTL		30		/* default time to live for SPP segs */
+/*
+ * Time constants.
+ */
+#define	SPPTV_MSL	( 15*PR_SLOWHZ)		/* max seg lifetime */
+#define	SPPTV_SRTTBASE	0			/* base roundtrip time;
+						   if 0, no idea yet */
+#define	SPPTV_SRTTDFLT	(  3*PR_SLOWHZ)		/* assumed RTT if no info */
+
+#define	SPPTV_PERSMIN	(  5*PR_SLOWHZ)		/* retransmit persistance */
+#define	SPPTV_PERSMAX	( 60*PR_SLOWHZ)		/* maximum persist interval */
+
+#define	SPPTV_KEEP	( 75*PR_SLOWHZ)		/* keep alive - 75 secs */
+#define	SPPTV_MAXIDLE	(  8*SPPTV_KEEP)	/* maximum allowable idle
+						   time before drop conn */
+
+#define	SPPTV_MIN	(  1*PR_SLOWHZ)		/* minimum allowable value */
+#define	SPPTV_REXMTMAX	( 64*PR_SLOWHZ)		/* max allowable REXMT value */
+
+#define	SPP_LINGERTIME	120			/* linger at most 2 minutes */
+
+#define	SPP_MAXRXTSHIFT	12			/* maximum retransmits */
+
+#ifdef	SPPTIMERS
+char *spptimers[] =
+    { "REXMT", "PERSIST", "KEEP", "2MSL" };
+#endif
+
+/*
+ * Force a time value to be in a certain range.
+ */
+#define	SPPT_RANGESET(tv, value, tvmin, tvmax) { \
+	(tv) = (value); \
+	if ((tv) < (tvmin)) \
+		(tv) = (tvmin); \
+	else if ((tv) > (tvmax)) \
+		(tv) = (tvmax); \
+}
+
+#ifdef _KERNEL
+extern int spp_backoff[];
+#endif
diff --git a/sys/netns/spp_usrreq.c b/sys/netns/spp_usrreq.c
new file mode 100644
index 00000000000..b01ace450e6
--- /dev/null
+++ b/sys/netns/spp_usrreq.c
@@ -0,0 +1,1805 @@
+/*	$NetBSD: spp_usrreq.c,v 1.8 1995/08/16 00:32:42 mycroft Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)spp_usrreq.c	8.1 (Berkeley) 6/10/93
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/protosw.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/errno.h>
+
+#include <net/if.h>
+#include <net/route.h>
+#include <netinet/tcp_fsm.h>
+
+#include <netns/ns.h>
+#include <netns/ns_pcb.h>
+#include <netns/idp.h>
+#include <netns/idp_var.h>
+#include <netns/ns_error.h>
+#include <netns/sp.h>
+#include <netns/spidp.h>
+#include <netns/spp_timer.h>
+#include <netns/spp_var.h>
+#include <netns/spp_debug.h>
+
+/*
+ * SP protocol implementation.
+ */
+spp_init()
+{
+
+	spp_iss = 1; /* WRONG !! should fish it out of TODR */
+}
+struct spidp spp_savesi;
+int traceallspps = 0;
+extern int sppconsdebug;
+int spp_hardnosed;
+int spp_use_delack = 0;
+u_short spp_newchecks[50];
+
+/*ARGSUSED*/
+spp_input(m, nsp)
+	register struct mbuf *m;
+	register struct nspcb *nsp;
+{
+	register struct sppcb *cb;
+	register struct spidp *si = mtod(m, struct spidp *);
+	register struct socket *so;
+	short ostate;
+	int dropsocket = 0;
+
+
+	sppstat.spps_rcvtotal++;
+	if (nsp == 0) {
+		panic("No nspcb in spp_input\n");
+		return;
+	}
+
+	cb = nstosppcb(nsp);
+	if (cb == 0) goto bad;
+
+	if (m->m_len < sizeof(*si)) {
+		if ((m = m_pullup(m, sizeof(*si))) == 0) {
+			sppstat.spps_rcvshort++;
+			return;
+		}
+		si = mtod(m, struct spidp *);
+	}
+	si->si_seq = ntohs(si->si_seq);
+	si->si_ack = ntohs(si->si_ack);
+	si->si_alo = ntohs(si->si_alo);
+
+	so = nsp->nsp_socket;
+	if (so->so_options & SO_DEBUG || traceallspps) {
+		ostate = cb->s_state;
+		spp_savesi = *si;
+	}
+	if (so->so_options & SO_ACCEPTCONN) {
+		struct sppcb *ocb = cb;
+
+		so = sonewconn(so, 0);
+		if (so == 0) {
+			goto drop;
+		}
+		/*
+		 * This is ugly, but ....
+		 *
+		 * Mark socket as temporary until we're
+		 * committed to keeping it.  The code at
+		 * ``drop'' and ``dropwithreset'' check the
+		 * flag dropsocket to see if the temporary
+		 * socket created here should be discarded.
+		 * We mark the socket as discardable until
+		 * we're committed to it below in TCPS_LISTEN.
+		 */
+		dropsocket++;
+		nsp = (struct nspcb *)so->so_pcb;
+		nsp->nsp_laddr = si->si_dna;
+		cb = nstosppcb(nsp);
+		cb->s_mtu = ocb->s_mtu;		/* preserve sockopts */
+		cb->s_flags = ocb->s_flags;	/* preserve sockopts */
+		cb->s_flags2 = ocb->s_flags2;	/* preserve sockopts */
+		cb->s_state = TCPS_LISTEN;
+	}
+
+	/*
+	 * Packet received on connection.
+	 * reset idle time and keep-alive timer;
+	 */
+	cb->s_idle = 0;
+	cb->s_timer[SPPT_KEEP] = SPPTV_KEEP;
+
+	switch (cb->s_state) {
+
+	case TCPS_LISTEN:{
+		struct mbuf *am;
+		register struct sockaddr_ns *sns;
+		struct ns_addr laddr;
+
+		/*
+		 * If somebody here was carying on a conversation
+		 * and went away, and his pen pal thinks he can
+		 * still talk, we get the misdirected packet.
+		 */
+		if (spp_hardnosed && (si->si_did != 0 || si->si_seq != 0)) {
+			spp_istat.gonawy++;
+			goto dropwithreset;
+		}
+		am = m_get(M_DONTWAIT, MT_SONAME);
+		if (am == NULL)
+			goto drop;
+		am->m_len = sizeof (struct sockaddr_ns);
+		sns = mtod(am, struct sockaddr_ns *);
+		sns->sns_len = sizeof(*sns);
+		sns->sns_family = AF_NS;
+		sns->sns_addr = si->si_sna;
+		laddr = nsp->nsp_laddr;
+		if (ns_nullhost(laddr))
+			nsp->nsp_laddr = si->si_dna;
+		if (ns_pcbconnect(nsp, am)) {
+			nsp->nsp_laddr = laddr;
+			(void) m_free(am);
+			spp_istat.noconn++;
+			goto drop;
+		}
+		(void) m_free(am);
+		spp_template(cb);
+		dropsocket = 0;		/* committed to socket */
+		cb->s_did = si->si_sid;
+		cb->s_rack = si->si_ack;
+		cb->s_ralo = si->si_alo;
+#define THREEWAYSHAKE
+#ifdef THREEWAYSHAKE
+		cb->s_state = TCPS_SYN_RECEIVED;
+		cb->s_force = 1 + SPPT_KEEP;
+		sppstat.spps_accepts++;
+		cb->s_timer[SPPT_KEEP] = SPPTV_KEEP;
+		}
+		break;
+	/*
+	 * This state means that we have heard a response
+	 * to our acceptance of their connection
+	 * It is probably logically unnecessary in this
+	 * implementation.
+	 */
+	 case TCPS_SYN_RECEIVED: {
+		if (si->si_did!=cb->s_sid) {
+			spp_istat.wrncon++;
+			goto drop;
+		}
+#endif
+		nsp->nsp_fport =  si->si_sport;
+		cb->s_timer[SPPT_REXMT] = 0;
+		cb->s_timer[SPPT_KEEP] = SPPTV_KEEP;
+		soisconnected(so);
+		cb->s_state = TCPS_ESTABLISHED;
+		sppstat.spps_accepts++;
+		}
+		break;
+
+	/*
+	 * This state means that we have gotten a response
+	 * to our attempt to establish a connection.
+	 * We fill in the data from the other side,
+	 * telling us which port to respond to, instead of the well-
+	 * known one we might have sent to in the first place.
+	 * We also require that this is a response to our
+	 * connection id.
+	 */
+	case TCPS_SYN_SENT:
+		if (si->si_did!=cb->s_sid) {
+			spp_istat.notme++;
+			goto drop;
+		}
+		sppstat.spps_connects++;
+		cb->s_did = si->si_sid;
+		cb->s_rack = si->si_ack;
+		cb->s_ralo = si->si_alo;
+		cb->s_dport = nsp->nsp_fport =  si->si_sport;
+		cb->s_timer[SPPT_REXMT] = 0;
+		cb->s_flags |= SF_ACKNOW;
+		soisconnected(so);
+		cb->s_state = TCPS_ESTABLISHED;
+		/* Use roundtrip time of connection request for initial rtt */
+		if (cb->s_rtt) {
+			cb->s_srtt = cb->s_rtt << 3;
+			cb->s_rttvar = cb->s_rtt << 1;
+			SPPT_RANGESET(cb->s_rxtcur,
+			    ((cb->s_srtt >> 2) + cb->s_rttvar) >> 1,
+			    SPPTV_MIN, SPPTV_REXMTMAX);
+			    cb->s_rtt = 0;
+		}
+	}
+	if (so->so_options & SO_DEBUG || traceallspps)
+		spp_trace(SA_INPUT, (u_char)ostate, cb, &spp_savesi, 0);
+
+	m->m_len -= sizeof (struct idp);
+	m->m_pkthdr.len -= sizeof (struct idp);
+	m->m_data += sizeof (struct idp);
+
+	if (spp_reass(cb, si)) {
+		(void) m_freem(m);
+	}
+	if (cb->s_force || (cb->s_flags & (SF_ACKNOW|SF_WIN|SF_RXT)))
+		(void) spp_output(cb, (struct mbuf *)0);
+	cb->s_flags &= ~(SF_WIN|SF_RXT);
+	return;
+
+dropwithreset:
+	if (dropsocket)
+		(void) soabort(so);
+	si->si_seq = ntohs(si->si_seq);
+	si->si_ack = ntohs(si->si_ack);
+	si->si_alo = ntohs(si->si_alo);
+	ns_error(dtom(si), NS_ERR_NOSOCK, 0);
+	if (cb->s_nspcb->nsp_socket->so_options & SO_DEBUG || traceallspps)
+		spp_trace(SA_DROP, (u_char)ostate, cb, &spp_savesi, 0);
+	return;
+
+drop:
+bad:
+	if (cb == 0 || cb->s_nspcb->nsp_socket->so_options & SO_DEBUG ||
+            traceallspps)
+		spp_trace(SA_DROP, (u_char)ostate, cb, &spp_savesi, 0);
+	m_freem(m);
+}
+
+int spprexmtthresh = 3;
+
+/*
+ * This is structurally similar to the tcp reassembly routine
+ * but its function is somewhat different:  It merely queues
+ * packets up, and suppresses duplicates.
+ */
+spp_reass(cb, si)
+register struct sppcb *cb;
+register struct spidp *si;
+{
+	register struct spidp_q *q;
+	register struct mbuf *m;
+	register struct socket *so = cb->s_nspcb->nsp_socket;
+	char packetp = cb->s_flags & SF_HI;
+	int incr;
+	char wakeup = 0;
+
+	if (si == SI(0))
+		goto present;
+	/*
+	 * Update our news from them.
+	 */
+	if (si->si_cc & SP_SA)
+		cb->s_flags |= (spp_use_delack ? SF_DELACK : SF_ACKNOW);
+	if (SSEQ_GT(si->si_alo, cb->s_ralo))
+		cb->s_flags |= SF_WIN;
+	if (SSEQ_LEQ(si->si_ack, cb->s_rack)) {
+		if ((si->si_cc & SP_SP) && cb->s_rack != (cb->s_smax + 1)) {
+			sppstat.spps_rcvdupack++;
+			/*
+			 * If this is a completely duplicate ack
+			 * and other conditions hold, we assume
+			 * a packet has been dropped and retransmit
+			 * it exactly as in tcp_input().
+			 */
+			if (si->si_ack != cb->s_rack ||
+			    si->si_alo != cb->s_ralo)
+				cb->s_dupacks = 0;
+			else if (++cb->s_dupacks == spprexmtthresh) {
+				u_short onxt = cb->s_snxt;
+				int cwnd = cb->s_cwnd;
+
+				cb->s_snxt = si->si_ack;
+				cb->s_cwnd = CUNIT;
+				cb->s_force = 1 + SPPT_REXMT;
+				(void) spp_output(cb, (struct mbuf *)0);
+				cb->s_timer[SPPT_REXMT] = cb->s_rxtcur;
+				cb->s_rtt = 0;
+				if (cwnd >= 4 * CUNIT)
+					cb->s_cwnd = cwnd / 2;
+				if (SSEQ_GT(onxt, cb->s_snxt))
+					cb->s_snxt = onxt;
+				return (1);
+			}
+		} else
+			cb->s_dupacks = 0;
+		goto update_window;
+	}
+	cb->s_dupacks = 0;
+	/*
+	 * If our correspondent acknowledges data we haven't sent
+	 * TCP would drop the packet after acking.  We'll be a little
+	 * more permissive
+	 */
+	if (SSEQ_GT(si->si_ack, (cb->s_smax + 1))) {
+		sppstat.spps_rcvacktoomuch++;
+		si->si_ack = cb->s_smax + 1;
+	}
+	sppstat.spps_rcvackpack++;
+	/*
+	 * If transmit timer is running and timed sequence
+	 * number was acked, update smoothed round trip time.
+	 * See discussion of algorithm in tcp_input.c
+	 */
+	if (cb->s_rtt && SSEQ_GT(si->si_ack, cb->s_rtseq)) {
+		sppstat.spps_rttupdated++;
+		if (cb->s_srtt != 0) {
+			register short delta;
+			delta = cb->s_rtt - (cb->s_srtt >> 3);
+			if ((cb->s_srtt += delta) <= 0)
+				cb->s_srtt = 1;
+			if (delta < 0)
+				delta = -delta;
+			delta -= (cb->s_rttvar >> 2);
+			if ((cb->s_rttvar += delta) <= 0)
+				cb->s_rttvar = 1;
+		} else {
+			/*
+			 * No rtt measurement yet
+			 */
+			cb->s_srtt = cb->s_rtt << 3;
+			cb->s_rttvar = cb->s_rtt << 1;
+		}
+		cb->s_rtt = 0;
+		cb->s_rxtshift = 0;
+		SPPT_RANGESET(cb->s_rxtcur,
+			((cb->s_srtt >> 2) + cb->s_rttvar) >> 1,
+			SPPTV_MIN, SPPTV_REXMTMAX);
+	}
+	/*
+	 * If all outstanding data is acked, stop retransmit
+	 * timer and remember to restart (more output or persist).
+	 * If there is more data to be acked, restart retransmit
+	 * timer, using current (possibly backed-off) value;
+	 */
+	if (si->si_ack == cb->s_smax + 1) {
+		cb->s_timer[SPPT_REXMT] = 0;
+		cb->s_flags |= SF_RXT;
+	} else if (cb->s_timer[SPPT_PERSIST] == 0)
+		cb->s_timer[SPPT_REXMT] = cb->s_rxtcur;
+	/*
+	 * When new data is acked, open the congestion window.
+	 * If the window gives us less than ssthresh packets
+	 * in flight, open exponentially (maxseg at a time).
+	 * Otherwise open linearly (maxseg^2 / cwnd at a time).
+	 */
+	incr = CUNIT;
+	if (cb->s_cwnd > cb->s_ssthresh)
+		incr = max(incr * incr / cb->s_cwnd, 1);
+	cb->s_cwnd = min(cb->s_cwnd + incr, cb->s_cwmx);
+	/*
+	 * Trim Acked data from output queue.
+	 */
+	while ((m = so->so_snd.sb_mb) != NULL) {
+		if (SSEQ_LT((mtod(m, struct spidp *))->si_seq, si->si_ack))
+			sbdroprecord(&so->so_snd);
+		else
+			break;
+	}
+	sowwakeup(so);
+	cb->s_rack = si->si_ack;
+update_window:
+	if (SSEQ_LT(cb->s_snxt, cb->s_rack))
+		cb->s_snxt = cb->s_rack;
+	if (SSEQ_LT(cb->s_swl1, si->si_seq) || cb->s_swl1 == si->si_seq &&
+	    (SSEQ_LT(cb->s_swl2, si->si_ack) ||
+	     cb->s_swl2 == si->si_ack && SSEQ_LT(cb->s_ralo, si->si_alo))) {
+		/* keep track of pure window updates */
+		if ((si->si_cc & SP_SP) && cb->s_swl2 == si->si_ack
+		    && SSEQ_LT(cb->s_ralo, si->si_alo)) {
+			sppstat.spps_rcvwinupd++;
+			sppstat.spps_rcvdupack--;
+		}
+		cb->s_ralo = si->si_alo;
+		cb->s_swl1 = si->si_seq;
+		cb->s_swl2 = si->si_ack;
+		cb->s_swnd = (1 + si->si_alo - si->si_ack);
+		if (cb->s_swnd > cb->s_smxw)
+			cb->s_smxw = cb->s_swnd;
+		cb->s_flags |= SF_WIN;
+	}
+	/*
+	 * If this packet number is higher than that which
+	 * we have allocated refuse it, unless urgent
+	 */
+	if (SSEQ_GT(si->si_seq, cb->s_alo)) {
+		if (si->si_cc & SP_SP) {
+			sppstat.spps_rcvwinprobe++;
+			return (1);
+		} else
+			sppstat.spps_rcvpackafterwin++;
+		if (si->si_cc & SP_OB) {
+			if (SSEQ_GT(si->si_seq, cb->s_alo + 60)) {
+				ns_error(dtom(si), NS_ERR_FULLUP, 0);
+				return (0);
+			} /* else queue this packet; */
+		} else {
+			/*register struct socket *so = cb->s_nspcb->nsp_socket;
+			if (so->so_state && SS_NOFDREF) {
+				ns_error(dtom(si), NS_ERR_NOSOCK, 0);
+				(void)spp_close(cb);
+			} else
+				       would crash system*/
+			spp_istat.notyet++;
+			ns_error(dtom(si), NS_ERR_FULLUP, 0);
+			return (0);
+		}
+	}
+	/*
+	 * If this is a system packet, we don't need to
+	 * queue it up, and won't update acknowledge #
+	 */
+	if (si->si_cc & SP_SP) {
+		return (1);
+	}
+	/*
+	 * We have already seen this packet, so drop.
+	 */
+	if (SSEQ_LT(si->si_seq, cb->s_ack)) {
+		spp_istat.bdreas++;
+		sppstat.spps_rcvduppack++;
+		if (si->si_seq == cb->s_ack - 1)
+			spp_istat.lstdup++;
+		return (1);
+	}
+	/*
+	 * Loop through all packets queued up to insert in
+	 * appropriate sequence.
+	 */
+	for (q = cb->s_q.si_next; q!=&cb->s_q; q = q->si_next) {
+		if (si->si_seq == SI(q)->si_seq) {
+			sppstat.spps_rcvduppack++;
+			return (1);
+		}
+		if (SSEQ_LT(si->si_seq, SI(q)->si_seq)) {
+			sppstat.spps_rcvoopack++;
+			break;
+		}
+	}
+	insque(si, q->si_prev);
+	/*
+	 * If this packet is urgent, inform process
+	 */
+	if (si->si_cc & SP_OB) {
+		cb->s_iobc = ((char *)si)[1 + sizeof(*si)];
+		sohasoutofband(so);
+		cb->s_oobflags |= SF_IOOB;
+	}
+present:
+#define SPINC sizeof(struct sphdr)
+	/*
+	 * Loop through all packets queued up to update acknowledge
+	 * number, and present all acknowledged data to user;
+	 * If in packet interface mode, show packet headers.
+	 */
+	for (q = cb->s_q.si_next; q!=&cb->s_q; q = q->si_next) {
+		  if (SI(q)->si_seq == cb->s_ack) {
+			cb->s_ack++;
+			m = dtom(q);
+			if (SI(q)->si_cc & SP_OB) {
+				cb->s_oobflags &= ~SF_IOOB;
+				if (so->so_rcv.sb_cc)
+					so->so_oobmark = so->so_rcv.sb_cc;
+				else
+					so->so_state |= SS_RCVATMARK;
+			}
+			q = q->si_prev;
+			remque(q->si_next);
+			wakeup = 1;
+			sppstat.spps_rcvpack++;
+#ifdef SF_NEWCALL
+			if (cb->s_flags2 & SF_NEWCALL) {
+				struct sphdr *sp = mtod(m, struct sphdr *);
+				u_char dt = sp->sp_dt;
+				spp_newchecks[4]++;
+				if (dt != cb->s_rhdr.sp_dt) {
+					struct mbuf *mm =
+					   m_getclr(M_DONTWAIT, MT_CONTROL);
+					spp_newchecks[0]++;
+					if (mm != NULL) {
+						u_short *s =
+							mtod(mm, u_short *);
+						cb->s_rhdr.sp_dt = dt;
+						mm->m_len = 5; /*XXX*/
+						s[0] = 5;
+						s[1] = 1;
+						*(u_char *)(&s[2]) = dt;
+						sbappend(&so->so_rcv, mm);
+					}
+				}
+				if (sp->sp_cc & SP_OB) {
+					MCHTYPE(m, MT_OOBDATA);
+					spp_newchecks[1]++;
+					so->so_oobmark = 0;
+					so->so_state &= ~SS_RCVATMARK;
+				}
+				if (packetp == 0) {
+					m->m_data += SPINC;
+					m->m_len -= SPINC;
+					m->m_pkthdr.len -= SPINC;
+				}
+				if ((sp->sp_cc & SP_EM) || packetp) {
+					sbappendrecord(&so->so_rcv, m);
+					spp_newchecks[9]++;
+				} else
+					sbappend(&so->so_rcv, m);
+			} else
+#endif
+			if (packetp) {
+				sbappendrecord(&so->so_rcv, m);
+			} else {
+				cb->s_rhdr = *mtod(m, struct sphdr *);
+				m->m_data += SPINC;
+				m->m_len -= SPINC;
+				m->m_pkthdr.len -= SPINC;
+				sbappend(&so->so_rcv, m);
+			}
+		  } else
+			break;
+	}
+	if (wakeup) sorwakeup(so);
+	return (0);
+}
+
+spp_ctlinput(cmd, arg)
+	int cmd;
+	caddr_t arg;
+{
+	struct ns_addr *na;
+	extern u_char nsctlerrmap[];
+	extern spp_abort(), spp_quench();
+	extern struct nspcb *idp_drop();
+	struct ns_errp *errp;
+	struct nspcb *nsp;
+	struct sockaddr_ns *sns;
+	int type;
+
+	if (cmd < 0 || cmd > PRC_NCMDS)
+		return;
+	type = NS_ERR_UNREACH_HOST;
+
+	switch (cmd) {
+
+	case PRC_ROUTEDEAD:
+		return;
+
+	case PRC_IFDOWN:
+	case PRC_HOSTDEAD:
+	case PRC_HOSTUNREACH:
+		sns = (struct sockaddr_ns *)arg;
+		if (sns->sns_family != AF_NS)
+			return;
+		na = &sns->sns_addr;
+		break;
+
+	default:
+		errp = (struct ns_errp *)arg;
+		na = &errp->ns_err_idp.idp_dna;
+		type = errp->ns_err_num;
+		type = ntohs((u_short)type);
+	}
+	switch (type) {
+
+	case NS_ERR_UNREACH_HOST:
+		ns_pcbnotify(na, (int)nsctlerrmap[cmd], spp_abort, (long) 0);
+		break;
+
+	case NS_ERR_TOO_BIG:
+	case NS_ERR_NOSOCK:
+		nsp = ns_pcblookup(na, errp->ns_err_idp.idp_sna.x_port,
+			NS_WILDCARD);
+		if (nsp) {
+			if(nsp->nsp_pcb)
+				(void) spp_drop((struct sppcb *)nsp->nsp_pcb,
+						(int)nsctlerrmap[cmd]);
+			else
+				(void) idp_drop(nsp, (int)nsctlerrmap[cmd]);
+		}
+		break;
+
+	case NS_ERR_FULLUP:
+		ns_pcbnotify(na, 0, spp_quench, (long) 0);
+	}
+}
+/*
+ * When a source quench is received, close congestion window
+ * to one packet.  We will gradually open it again as we proceed.
+ */
+spp_quench(nsp)
+	struct nspcb *nsp;
+{
+	struct sppcb *cb = nstosppcb(nsp);
+
+	if (cb)
+		cb->s_cwnd = CUNIT;
+}
+
+#ifdef notdef
+int
+spp_fixmtu(nsp)
+register struct nspcb *nsp;
+{
+	register struct sppcb *cb = (struct sppcb *)(nsp->nsp_pcb);
+	register struct mbuf *m;
+	register struct spidp *si;
+	struct ns_errp *ep;
+	struct sockbuf *sb;
+	int badseq, len;
+	struct mbuf *firstbad, *m0;
+
+	if (cb) {
+		/* 
+		 * The notification that we have sent
+		 * too much is bad news -- we will
+		 * have to go through queued up so far
+		 * splitting ones which are too big and
+		 * reassigning sequence numbers and checksums.
+		 * we should then retransmit all packets from
+		 * one above the offending packet to the last one
+		 * we had sent (or our allocation)
+		 * then the offending one so that the any queued
+		 * data at our destination will be discarded.
+		 */
+		 ep = (struct ns_errp *)nsp->nsp_notify_param;
+		 sb = &nsp->nsp_socket->so_snd;
+		 cb->s_mtu = ep->ns_err_param;
+		 badseq = SI(&ep->ns_err_idp)->si_seq;
+		 for (m = sb->sb_mb; m; m = m->m_act) {
+			si = mtod(m, struct spidp *);
+			if (si->si_seq == badseq)
+				break;
+		 }
+		 if (m == 0) return;
+		 firstbad = m;
+		 /*for (;;) {*/
+			/* calculate length */
+			for (m0 = m, len = 0; m ; m = m->m_next)
+				len += m->m_len;
+			if (len > cb->s_mtu) {
+			}
+		/* FINISH THIS
+		} */
+	}
+}
+#endif
+
+spp_output(cb, m0)
+	register struct sppcb *cb;
+	struct mbuf *m0;
+{
+	struct socket *so = cb->s_nspcb->nsp_socket;
+	register struct mbuf *m;
+	register struct spidp *si = (struct spidp *) 0;
+	register struct sockbuf *sb = &so->so_snd;
+	int len = 0, win, rcv_win;
+	short span, off, recordp = 0;
+	u_short alo;
+	int error = 0, sendalot;
+#ifdef notdef
+	int idle;
+#endif
+	struct mbuf *mprev;
+	extern int idpcksum;
+
+	if (m0) {
+		int mtu = cb->s_mtu;
+		int datalen;
+		/*
+		 * Make sure that packet isn't too big.
+		 */
+		for (m = m0; m ; m = m->m_next) {
+			mprev = m;
+			len += m->m_len;
+			if (m->m_flags & M_EOR)
+				recordp = 1;
+		}
+		datalen = (cb->s_flags & SF_HO) ?
+				len - sizeof (struct sphdr) : len;
+		if (datalen > mtu) {
+			if (cb->s_flags & SF_PI) {
+				m_freem(m0);
+				return (EMSGSIZE);
+			} else {
+				int oldEM = cb->s_cc & SP_EM;
+
+				cb->s_cc &= ~SP_EM;
+				while (len > mtu) {
+					/*
+					 * Here we are only being called
+					 * from usrreq(), so it is OK to
+					 * block.
+					 */
+					m = m_copym(m0, 0, mtu, M_WAIT);
+					if (cb->s_flags & SF_NEWCALL) {
+					    struct mbuf *mm = m;
+					    spp_newchecks[7]++;
+					    while (mm) {
+						mm->m_flags &= ~M_EOR;
+						mm = mm->m_next;
+					    }
+					}
+					error = spp_output(cb, m);
+					if (error) {
+						cb->s_cc |= oldEM;
+						m_freem(m0);
+						return(error);
+					}
+					m_adj(m0, mtu);
+					len -= mtu;
+				}
+				cb->s_cc |= oldEM;
+			}
+		}
+		/*
+		 * Force length even, by adding a "garbage byte" if
+		 * necessary.
+		 */
+		if (len & 1) {
+			m = mprev;
+			if (M_TRAILINGSPACE(m) >= 1)
+				m->m_len++;
+			else {
+				struct mbuf *m1 = m_get(M_DONTWAIT, MT_DATA);
+
+				if (m1 == 0) {
+					m_freem(m0);
+					return (ENOBUFS);
+				}
+				m1->m_len = 1;
+				*(mtod(m1, u_char *)) = 0;
+				m->m_next = m1;
+			}
+		}
+		m = m_gethdr(M_DONTWAIT, MT_HEADER);
+		if (m == 0) {
+			m_freem(m0);
+			return (ENOBUFS);
+		}
+		/*
+		 * Fill in mbuf with extended SP header
+		 * and addresses and length put into network format.
+		 */
+		MH_ALIGN(m, sizeof (struct spidp));
+		m->m_len = sizeof (struct spidp);
+		m->m_next = m0;
+		si = mtod(m, struct spidp *);
+		si->si_i = *cb->s_idp;
+		si->si_s = cb->s_shdr;
+		if ((cb->s_flags & SF_PI) && (cb->s_flags & SF_HO)) {
+			register struct sphdr *sh;
+			if (m0->m_len < sizeof (*sh)) {
+				if((m0 = m_pullup(m0, sizeof(*sh))) == NULL) {
+					(void) m_free(m);
+					m_freem(m0);
+					return (EINVAL);
+				}
+				m->m_next = m0;
+			}
+			sh = mtod(m0, struct sphdr *);
+			si->si_dt = sh->sp_dt;
+			si->si_cc |= sh->sp_cc & SP_EM;
+			m0->m_len -= sizeof (*sh);
+			m0->m_data += sizeof (*sh);
+			len -= sizeof (*sh);
+		}
+		len += sizeof(*si);
+		if ((cb->s_flags2 & SF_NEWCALL) && recordp) {
+			si->si_cc  |= SP_EM;
+			spp_newchecks[8]++;
+		}
+		if (cb->s_oobflags & SF_SOOB) {
+			/*
+			 * Per jqj@cornell:
+			 * make sure OB packets convey exactly 1 byte.
+			 * If the packet is 1 byte or larger, we
+			 * have already guaranted there to be at least
+			 * one garbage byte for the checksum, and
+			 * extra bytes shouldn't hurt!
+			 */
+			if (len > sizeof(*si)) {
+				si->si_cc |= SP_OB;
+				len = (1 + sizeof(*si));
+			}
+		}
+		si->si_len = htons((u_short)len);
+		m->m_pkthdr.len = ((len - 1) | 1) + 1;
+		/*
+		 * queue stuff up for output
+		 */
+		sbappendrecord(sb, m);
+		cb->s_seq++;
+	}
+#ifdef notdef
+	idle = (cb->s_smax == (cb->s_rack - 1));
+#endif
+again:
+	sendalot = 0;
+	off = cb->s_snxt - cb->s_rack;
+	win = min(cb->s_swnd, (cb->s_cwnd/CUNIT));
+
+	/*
+	 * If in persist timeout with window of 0, send a probe.
+	 * Otherwise, if window is small but nonzero
+	 * and timer expired, send what we can and go into
+	 * transmit state.
+	 */
+	if (cb->s_force == 1 + SPPT_PERSIST) {
+		if (win != 0) {
+			cb->s_timer[SPPT_PERSIST] = 0;
+			cb->s_rxtshift = 0;
+		}
+	}
+	span = cb->s_seq - cb->s_rack;
+	len = min(span, win) - off;
+
+	if (len < 0) {
+		/*
+		 * Window shrank after we went into it.
+		 * If window shrank to 0, cancel pending
+		 * restransmission and pull s_snxt back
+		 * to (closed) window.  We will enter persist
+		 * state below.  If the widndow didn't close completely,
+		 * just wait for an ACK.
+		 */
+		len = 0;
+		if (win == 0) {
+			cb->s_timer[SPPT_REXMT] = 0;
+			cb->s_snxt = cb->s_rack;
+		}
+	}
+	if (len > 1)
+		sendalot = 1;
+	rcv_win = sbspace(&so->so_rcv);
+
+	/*
+	 * Send if we owe peer an ACK.
+	 */
+	if (cb->s_oobflags & SF_SOOB) {
+		/*
+		 * must transmit this out of band packet
+		 */
+		cb->s_oobflags &= ~ SF_SOOB;
+		sendalot = 1;
+		sppstat.spps_sndurg++;
+		goto found;
+	}
+	if (cb->s_flags & SF_ACKNOW)
+		goto send;
+	if (cb->s_state < TCPS_ESTABLISHED)
+		goto send;
+	/*
+	 * Silly window can't happen in spp.
+	 * Code from tcp deleted.
+	 */
+	if (len)
+		goto send;
+	/*
+	 * Compare available window to amount of window
+	 * known to peer (as advertised window less
+	 * next expected input.)  If the difference is at least two
+	 * packets or at least 35% of the mximum possible window,
+	 * then want to send a window update to peer.
+	 */
+	if (rcv_win > 0) {
+		u_short delta =  1 + cb->s_alo - cb->s_ack;
+		int adv = rcv_win - (delta * cb->s_mtu);
+		
+		if ((so->so_rcv.sb_cc == 0 && adv >= (2 * cb->s_mtu)) ||
+		    (100 * adv / so->so_rcv.sb_hiwat >= 35)) {
+			sppstat.spps_sndwinup++;
+			cb->s_flags |= SF_ACKNOW;
+			goto send;
+		}
+
+	}
+	/*
+	 * Many comments from tcp_output.c are appropriate here
+	 * including . . .
+	 * If send window is too small, there is data to transmit, and no
+	 * retransmit or persist is pending, then go to persist state.
+	 * If nothing happens soon, send when timer expires:
+	 * if window is nonzero, transmit what we can,
+	 * otherwise send a probe.
+	 */
+	if (so->so_snd.sb_cc && cb->s_timer[SPPT_REXMT] == 0 &&
+		cb->s_timer[SPPT_PERSIST] == 0) {
+			cb->s_rxtshift = 0;
+			spp_setpersist(cb);
+	}
+	/*
+	 * No reason to send a packet, just return.
+	 */
+	cb->s_outx = 1;
+	return (0);
+
+send:
+	/*
+	 * Find requested packet.
+	 */
+	si = 0;
+	if (len > 0) {
+		cb->s_want = cb->s_snxt;
+		for (m = sb->sb_mb; m; m = m->m_act) {
+			si = mtod(m, struct spidp *);
+			if (SSEQ_LEQ(cb->s_snxt, si->si_seq))
+				break;
+		}
+	found:
+		if (si) {
+			if (si->si_seq == cb->s_snxt)
+					cb->s_snxt++;
+				else
+					sppstat.spps_sndvoid++, si = 0;
+		}
+	}
+	/*
+	 * update window
+	 */
+	if (rcv_win < 0)
+		rcv_win = 0;
+	alo = cb->s_ack - 1 + (rcv_win / ((short)cb->s_mtu));
+	if (SSEQ_LT(alo, cb->s_alo)) 
+		alo = cb->s_alo;
+
+	if (si) {
+		/*
+		 * must make a copy of this packet for
+		 * idp_output to monkey with
+		 */
+		m = m_copy(dtom(si), 0, (int)M_COPYALL);
+		if (m == NULL) {
+			return (ENOBUFS);
+		}
+		si = mtod(m, struct spidp *);
+		if (SSEQ_LT(si->si_seq, cb->s_smax))
+			sppstat.spps_sndrexmitpack++;
+		else
+			sppstat.spps_sndpack++;
+	} else if (cb->s_force || cb->s_flags & SF_ACKNOW) {
+		/*
+		 * Must send an acknowledgement or a probe
+		 */
+		if (cb->s_force)
+			sppstat.spps_sndprobe++;
+		if (cb->s_flags & SF_ACKNOW)
+			sppstat.spps_sndacks++;
+		m = m_gethdr(M_DONTWAIT, MT_HEADER);
+		if (m == 0)
+			return (ENOBUFS);
+		/*
+		 * Fill in mbuf with extended SP header
+		 * and addresses and length put into network format.
+		 */
+		MH_ALIGN(m, sizeof (struct spidp));
+		m->m_len = sizeof (*si);
+		m->m_pkthdr.len = sizeof (*si);
+		si = mtod(m, struct spidp *);
+		si->si_i = *cb->s_idp;
+		si->si_s = cb->s_shdr;
+		si->si_seq = cb->s_smax + 1;
+		si->si_len = htons(sizeof (*si));
+		si->si_cc |= SP_SP;
+	} else {
+		cb->s_outx = 3;
+		if (so->so_options & SO_DEBUG || traceallspps)
+			spp_trace(SA_OUTPUT, cb->s_state, cb, si, 0);
+		return (0);
+	}
+	/*
+	 * Stuff checksum and output datagram.
+	 */
+	if ((si->si_cc & SP_SP) == 0) {
+		if (cb->s_force != (1 + SPPT_PERSIST) ||
+		    cb->s_timer[SPPT_PERSIST] == 0) {
+			/*
+			 * If this is a new packet and we are not currently 
+			 * timing anything, time this one.
+			 */
+			if (SSEQ_LT(cb->s_smax, si->si_seq)) {
+				cb->s_smax = si->si_seq;
+				if (cb->s_rtt == 0) {
+					sppstat.spps_segstimed++;
+					cb->s_rtseq = si->si_seq;
+					cb->s_rtt = 1;
+				}
+			}
+			/*
+			 * Set rexmt timer if not currently set,
+			 * Initial value for retransmit timer is smoothed
+			 * round-trip time + 2 * round-trip time variance.
+			 * Initialize shift counter which is used for backoff
+			 * of retransmit time.
+			 */
+			if (cb->s_timer[SPPT_REXMT] == 0 &&
+			    cb->s_snxt != cb->s_rack) {
+				cb->s_timer[SPPT_REXMT] = cb->s_rxtcur;
+				if (cb->s_timer[SPPT_PERSIST]) {
+					cb->s_timer[SPPT_PERSIST] = 0;
+					cb->s_rxtshift = 0;
+				}
+			}
+		} else if (SSEQ_LT(cb->s_smax, si->si_seq)) {
+			cb->s_smax = si->si_seq;
+		}
+	} else if (cb->s_state < TCPS_ESTABLISHED) {
+		if (cb->s_rtt == 0)
+			cb->s_rtt = 1; /* Time initial handshake */
+		if (cb->s_timer[SPPT_REXMT] == 0)
+			cb->s_timer[SPPT_REXMT] = cb->s_rxtcur;
+	}
+	{
+		/*
+		 * Do not request acks when we ack their data packets or
+		 * when we do a gratuitous window update.
+		 */
+		if (((si->si_cc & SP_SP) == 0) || cb->s_force)
+				si->si_cc |= SP_SA;
+		si->si_seq = htons(si->si_seq);
+		si->si_alo = htons(alo);
+		si->si_ack = htons(cb->s_ack);
+
+		if (idpcksum) {
+			si->si_sum = 0;
+			len = ntohs(si->si_len);
+			if (len & 1)
+				len++;
+			si->si_sum = ns_cksum(m, len);
+		} else
+			si->si_sum = 0xffff;
+
+		cb->s_outx = 4;
+		if (so->so_options & SO_DEBUG || traceallspps)
+			spp_trace(SA_OUTPUT, cb->s_state, cb, si, 0);
+
+		if (so->so_options & SO_DONTROUTE)
+			error = ns_output(m, (struct route *)0, NS_ROUTETOIF);
+		else
+			error = ns_output(m, &cb->s_nspcb->nsp_route, 0);
+	}
+	if (error) {
+		return (error);
+	}
+	sppstat.spps_sndtotal++;
+	/*
+	 * Data sent (as far as we can tell).
+	 * If this advertises a larger window than any other segment,
+	 * then remember the size of the advertized window.
+	 * Any pending ACK has now been sent.
+	 */
+	cb->s_force = 0;
+	cb->s_flags &= ~(SF_ACKNOW|SF_DELACK);
+	if (SSEQ_GT(alo, cb->s_alo))
+		cb->s_alo = alo;
+	if (sendalot)
+		goto again;
+	cb->s_outx = 5;
+	return (0);
+}
+
+int spp_do_persist_panics = 0;
+
+spp_setpersist(cb)
+	register struct sppcb *cb;
+{
+	register t = ((cb->s_srtt >> 2) + cb->s_rttvar) >> 1;
+	extern int spp_backoff[];
+
+	if (cb->s_timer[SPPT_REXMT] && spp_do_persist_panics)
+		panic("spp_output REXMT");
+	/*
+	 * Start/restart persistance timer.
+	 */
+	SPPT_RANGESET(cb->s_timer[SPPT_PERSIST],
+	    t*spp_backoff[cb->s_rxtshift],
+	    SPPTV_PERSMIN, SPPTV_PERSMAX);
+	if (cb->s_rxtshift < SPP_MAXRXTSHIFT)
+		cb->s_rxtshift++;
+}
+/*ARGSUSED*/
+spp_ctloutput(req, so, level, name, value)
+	int req;
+	struct socket *so;
+	int name;
+	struct mbuf **value;
+{
+	register struct mbuf *m;
+	struct nspcb *nsp = sotonspcb(so);
+	register struct sppcb *cb;
+	int mask, error = 0;
+
+	if (level != NSPROTO_SPP) {
+		/* This will have to be changed when we do more general
+		   stacking of protocols */
+		return (idp_ctloutput(req, so, level, name, value));
+	}
+	if (nsp == NULL) {
+		error = EINVAL;
+		goto release;
+	} else
+		cb = nstosppcb(nsp);
+
+	switch (req) {
+
+	case PRCO_GETOPT:
+		if (value == NULL)
+			return (EINVAL);
+		m = m_get(M_DONTWAIT, MT_DATA);
+		if (m == NULL)
+			return (ENOBUFS);
+		switch (name) {
+
+		case SO_HEADERS_ON_INPUT:
+			mask = SF_HI;
+			goto get_flags;
+
+		case SO_HEADERS_ON_OUTPUT:
+			mask = SF_HO;
+		get_flags:
+			m->m_len = sizeof(short);
+			*mtod(m, short *) = cb->s_flags & mask;
+			break;
+
+		case SO_MTU:
+			m->m_len = sizeof(u_short);
+			*mtod(m, short *) = cb->s_mtu;
+			break;
+
+		case SO_LAST_HEADER:
+			m->m_len = sizeof(struct sphdr);
+			*mtod(m, struct sphdr *) = cb->s_rhdr;
+			break;
+
+		case SO_DEFAULT_HEADERS:
+			m->m_len = sizeof(struct spidp);
+			*mtod(m, struct sphdr *) = cb->s_shdr;
+			break;
+
+		default:
+			error = EINVAL;
+		}
+		*value = m;
+		break;
+
+	case PRCO_SETOPT:
+		if (value == 0 || *value == 0) {
+			error = EINVAL;
+			break;
+		}
+		switch (name) {
+			int *ok;
+
+		case SO_HEADERS_ON_INPUT:
+			mask = SF_HI;
+			goto set_head;
+
+		case SO_HEADERS_ON_OUTPUT:
+			mask = SF_HO;
+		set_head:
+			if (cb->s_flags & SF_PI) {
+				ok = mtod(*value, int *);
+				if (*ok)
+					cb->s_flags |= mask;
+				else
+					cb->s_flags &= ~mask;
+			} else error = EINVAL;
+			break;
+
+		case SO_MTU:
+			cb->s_mtu = *(mtod(*value, u_short *));
+			break;
+
+#ifdef SF_NEWCALL
+		case SO_NEWCALL:
+			ok = mtod(*value, int *);
+			if (*ok) {
+				cb->s_flags2 |= SF_NEWCALL;
+				spp_newchecks[5]++;
+			} else {
+				cb->s_flags2 &= ~SF_NEWCALL;
+				spp_newchecks[6]++;
+			}
+			break;
+#endif
+
+		case SO_DEFAULT_HEADERS:
+			{
+				register struct sphdr *sp
+						= mtod(*value, struct sphdr *);
+				cb->s_dt = sp->sp_dt;
+				cb->s_cc = sp->sp_cc & SP_EM;
+			}
+			break;
+
+		default:
+			error = EINVAL;
+		}
+		m_freem(*value);
+		break;
+	}
+	release:
+		return (error);
+}
+
+/*ARGSUSED*/
+spp_usrreq(so, req, m, nam, controlp)
+	struct socket *so;
+	int req;
+	struct mbuf *m, *nam, *controlp;
+{
+	struct nspcb *nsp = sotonspcb(so);
+	register struct sppcb *cb;
+	int s = splsoftnet();
+	int error = 0, ostate;
+	struct mbuf *mm;
+	register struct sockbuf *sb;
+
+	if (req == PRU_CONTROL)
+                return (ns_control(so, (long)m, (caddr_t)nam,
+			(struct ifnet *)controlp));
+	if (nsp == NULL) {
+		if (req != PRU_ATTACH) {
+			error = EINVAL;
+			goto release;
+		}
+	} else
+		cb = nstosppcb(nsp);
+
+	ostate = cb ? cb->s_state : 0;
+
+	switch (req) {
+
+	case PRU_ATTACH:
+		if (nsp != NULL) {
+			error = EISCONN;
+			break;
+		}
+		error = ns_pcballoc(so, &nspcb);
+		if (error)
+			break;
+		if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
+			error = soreserve(so, (u_long) 3072, (u_long) 3072);
+			if (error)
+				break;
+		}
+		nsp = sotonspcb(so);
+		sb = &so->so_snd;
+
+		cb = malloc(sizeof(*cb), M_PCB, M_NOWAIT);
+		if (cb == 0) {
+			error = ENOBUFS;
+			break;
+		}
+		bzero((caddr_t)cb, sizeof(*cb));
+		cb->s_idp = malloc(sizeof(*cb->s_idp), M_PCB, M_NOWAIT);
+		if (cb->s_idp == 0) {
+			free(cb, M_PCB);
+			error = ENOBUFS;
+			break;
+		}
+		bzero((caddr_t)cb->s_idp, sizeof(*cb->s_idp));
+		cb->s_state = TCPS_LISTEN;
+		cb->s_smax = -1;
+		cb->s_swl1 = -1;
+		cb->s_q.si_next = cb->s_q.si_prev = &cb->s_q;
+		cb->s_nspcb = nsp;
+		cb->s_mtu = 576 - sizeof (struct spidp);
+		cb->s_cwnd = sbspace(sb) * CUNIT / cb->s_mtu;
+		cb->s_ssthresh = cb->s_cwnd;
+		cb->s_cwmx = sbspace(sb) * CUNIT /
+				(2 * sizeof (struct spidp));
+		/* Above is recomputed when connecting to account
+		   for changed buffering or mtu's */
+		cb->s_rtt = SPPTV_SRTTBASE;
+		cb->s_rttvar = SPPTV_SRTTDFLT << 2;
+		SPPT_RANGESET(cb->s_rxtcur,
+		    ((SPPTV_SRTTBASE >> 2) + (SPPTV_SRTTDFLT << 2)) >> 1,
+		    SPPTV_MIN, SPPTV_REXMTMAX);
+		nsp->nsp_pcb = (caddr_t) cb; 
+		break;
+
+	case PRU_DETACH:
+		if (nsp == NULL) {
+			error = ENOTCONN;
+			break;
+		}
+		if (cb->s_state > TCPS_LISTEN)
+			cb = spp_disconnect(cb);
+		else
+			cb = spp_close(cb);
+		break;
+
+	case PRU_BIND:
+		error = ns_pcbbind(nsp, nam);
+		break;
+
+	case PRU_LISTEN:
+		if (nsp->nsp_lport == 0)
+			error = ns_pcbbind(nsp, (struct mbuf *)0);
+		if (error == 0)
+			cb->s_state = TCPS_LISTEN;
+		break;
+
+	/*
+	 * Initiate connection to peer.
+	 * Enter SYN_SENT state, and mark socket as connecting.
+	 * Start keep-alive timer, setup prototype header,
+	 * Send initial system packet requesting connection.
+	 */
+	case PRU_CONNECT:
+		if (nsp->nsp_lport == 0) {
+			error = ns_pcbbind(nsp, (struct mbuf *)0);
+			if (error)
+				break;
+		}
+		error = ns_pcbconnect(nsp, nam);
+		if (error)
+			break;
+		soisconnecting(so);
+		sppstat.spps_connattempt++;
+		cb->s_state = TCPS_SYN_SENT;
+		cb->s_did = 0;
+		spp_template(cb);
+		cb->s_timer[SPPT_KEEP] = SPPTV_KEEP;
+		cb->s_force = 1 + SPPTV_KEEP;
+		/*
+		 * Other party is required to respond to
+		 * the port I send from, but he is not
+		 * required to answer from where I am sending to,
+		 * so allow wildcarding.
+		 * original port I am sending to is still saved in
+		 * cb->s_dport.
+		 */
+		nsp->nsp_fport = 0;
+		error = spp_output(cb, (struct mbuf *) 0);
+		break;
+
+	case PRU_CONNECT2:
+		error = EOPNOTSUPP;
+		break;
+
+	/*
+	 * We may decide later to implement connection closing
+	 * handshaking at the spp level optionally.
+	 * here is the hook to do it:
+	 */
+	case PRU_DISCONNECT:
+		cb = spp_disconnect(cb);
+		break;
+
+	/*
+	 * Accept a connection.  Essentially all the work is
+	 * done at higher levels; just return the address
+	 * of the peer, storing through addr.
+	 */
+	case PRU_ACCEPT: {
+		struct sockaddr_ns *sns = mtod(nam, struct sockaddr_ns *);
+
+		nam->m_len = sizeof (struct sockaddr_ns);
+		sns->sns_family = AF_NS;
+		sns->sns_addr = nsp->nsp_faddr;
+		break;
+		}
+
+	case PRU_SHUTDOWN:
+		socantsendmore(so);
+		cb = spp_usrclosed(cb);
+		if (cb)
+			error = spp_output(cb, (struct mbuf *) 0);
+		break;
+
+	/*
+	 * After a receive, possibly send acknowledgment
+	 * updating allocation.
+	 */
+	case PRU_RCVD:
+		cb->s_flags |= SF_RVD;
+		(void) spp_output(cb, (struct mbuf *) 0);
+		cb->s_flags &= ~SF_RVD;
+		break;
+
+	case PRU_ABORT:
+		(void) spp_drop(cb, ECONNABORTED);
+		break;
+
+	case PRU_SENSE:
+	case PRU_CONTROL:
+		m = NULL;
+		error = EOPNOTSUPP;
+		break;
+
+	case PRU_RCVOOB:
+		if ((cb->s_oobflags & SF_IOOB) || so->so_oobmark ||
+		    (so->so_state & SS_RCVATMARK)) {
+			m->m_len = 1;
+			*mtod(m, caddr_t) = cb->s_iobc;
+			break;
+		}
+		error = EINVAL;
+		break;
+
+	case PRU_SENDOOB:
+		if (sbspace(&so->so_snd) < -512) {
+			error = ENOBUFS;
+			break;
+		}
+		cb->s_oobflags |= SF_SOOB;
+		/* fall into */
+	case PRU_SEND:
+		if (controlp) {
+			u_short *p = mtod(controlp, u_short *);
+			spp_newchecks[2]++;
+			if ((p[0] == 5) && p[1] == 1) { /* XXXX, for testing */
+				cb->s_shdr.sp_dt = *(u_char *)(&p[2]);
+				spp_newchecks[3]++;
+			}
+			m_freem(controlp);
+		}
+		controlp = NULL;
+		error = spp_output(cb, m);
+		m = NULL;
+		break;
+
+	case PRU_SOCKADDR:
+		ns_setsockaddr(nsp, nam);
+		break;
+
+	case PRU_PEERADDR:
+		ns_setpeeraddr(nsp, nam);
+		break;
+
+	case PRU_SLOWTIMO:
+		cb = spp_timers(cb, (long)nam);
+		req |= ((long)nam) << 8;
+		break;
+
+	case PRU_FASTTIMO:
+	case PRU_PROTORCV:
+	case PRU_PROTOSEND:
+		error =  EOPNOTSUPP;
+		break;
+
+	default:
+		panic("sp_usrreq");
+	}
+	if (cb && (so->so_options & SO_DEBUG || traceallspps))
+		spp_trace(SA_USER, (u_char)ostate, cb, (struct spidp *)0, req);
+release:
+	if (controlp != NULL)
+		m_freem(controlp);
+	if (m != NULL)
+		m_freem(m);
+	splx(s);
+	return (error);
+}
+
+spp_usrreq_sp(so, req, m, nam, controlp)
+	struct socket *so;
+	int req;
+	struct mbuf *m, *nam, *controlp;
+{
+	int error = spp_usrreq(so, req, m, nam, controlp);
+
+	if (req == PRU_ATTACH && error == 0) {
+		struct nspcb *nsp = sotonspcb(so);
+		((struct sppcb *)nsp->nsp_pcb)->s_flags |=
+					(SF_HI | SF_HO | SF_PI);
+	}
+	return (error);
+}
+
+/*
+ * Create template to be used to send spp packets on a connection.
+ * Called after host entry created, fills
+ * in a skeletal spp header (choosing connection id),
+ * minimizing the amount of work necessary when the connection is used.
+ */
+spp_template(cb)
+	register struct sppcb *cb;
+{
+	register struct nspcb *nsp = cb->s_nspcb;
+	register struct idp *idp = cb->s_idp;
+	register struct sockbuf *sb = &(nsp->nsp_socket->so_snd);
+
+	idp->idp_pt = NSPROTO_SPP;
+	idp->idp_sna = nsp->nsp_laddr;
+	idp->idp_dna = nsp->nsp_faddr;
+	cb->s_sid = htons(spp_iss);
+	spp_iss += SPP_ISSINCR/2;
+	cb->s_alo = 1;
+	cb->s_cwnd = (sbspace(sb) * CUNIT) / cb->s_mtu;
+	cb->s_ssthresh = cb->s_cwnd; /* Try to expand fast to full complement
+					of large packets */
+	cb->s_cwmx = (sbspace(sb) * CUNIT) / (2 * sizeof(struct spidp));
+	cb->s_cwmx = max(cb->s_cwmx, cb->s_cwnd);
+		/* But allow for lots of little packets as well */
+}
+
+/*
+ * Close a SPIP control block:
+ *	discard spp control block itself
+ *	discard ns protocol control block
+ *	wake up any sleepers
+ */
+struct sppcb *
+spp_close(cb)
+	register struct sppcb *cb;
+{
+	register struct spidp_q *s;
+	struct nspcb *nsp = cb->s_nspcb;
+	struct socket *so = nsp->nsp_socket;
+	register struct mbuf *m;
+
+	s = cb->s_q.si_next;
+	while (s != &(cb->s_q)) {
+		s = s->si_next;
+		m = dtom(s->si_prev);
+		remque(s->si_prev);
+		m_freem(m);
+	}
+	free(cb->s_idp, M_PCB);
+	free(cb, M_PCB);
+	nsp->nsp_pcb = 0;
+	soisdisconnected(so);
+	ns_pcbdetach(nsp);
+	sppstat.spps_closed++;
+	return ((struct sppcb *)0);
+}
+/*
+ *	Someday we may do level 3 handshaking
+ *	to close a connection or send a xerox style error.
+ *	For now, just close.
+ */
+struct sppcb *
+spp_usrclosed(cb)
+	register struct sppcb *cb;
+{
+	return (spp_close(cb));
+}
+struct sppcb *
+spp_disconnect(cb)
+	register struct sppcb *cb;
+{
+	return (spp_close(cb));
+}
+/*
+ * Drop connection, reporting
+ * the specified error.
+ */
+struct sppcb *
+spp_drop(cb, errno)
+	register struct sppcb *cb;
+	int errno;
+{
+	struct socket *so = cb->s_nspcb->nsp_socket;
+
+	/*
+	 * someday, in the xerox world
+	 * we will generate error protocol packets
+	 * announcing that the socket has gone away.
+	 */
+	if (TCPS_HAVERCVDSYN(cb->s_state)) {
+		sppstat.spps_drops++;
+		cb->s_state = TCPS_CLOSED;
+		/*(void) tcp_output(cb);*/
+	} else
+		sppstat.spps_conndrops++;
+	so->so_error = errno;
+	return (spp_close(cb));
+}
+
+spp_abort(nsp)
+	struct nspcb *nsp;
+{
+
+	(void) spp_close((struct sppcb *)nsp->nsp_pcb);
+}
+
+int	spp_backoff[SPP_MAXRXTSHIFT+1] =
+    { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 };
+/*
+ * Fast timeout routine for processing delayed acks
+ */
+spp_fasttimo()
+{
+	register struct nspcb *nsp;
+	register struct sppcb *cb;
+	int s = splsoftnet();
+
+	nsp = nspcb.nsp_next;
+	if (nsp)
+	for (; nsp != &nspcb; nsp = nsp->nsp_next)
+		if ((cb = (struct sppcb *)nsp->nsp_pcb) &&
+		    (cb->s_flags & SF_DELACK)) {
+			cb->s_flags &= ~SF_DELACK;
+			cb->s_flags |= SF_ACKNOW;
+			sppstat.spps_delack++;
+			(void) spp_output(cb, (struct mbuf *) 0);
+		}
+	splx(s);
+}
+
+/*
+ * spp protocol timeout routine called every 500 ms.
+ * Updates the timers in all active pcb's and
+ * causes finite state machine actions if timers expire.
+ */
+spp_slowtimo()
+{
+	register struct nspcb *ip, *ipnxt;
+	register struct sppcb *cb;
+	int s = splsoftnet();
+	register long i;
+
+	/*
+	 * Search through tcb's and update active timers.
+	 */
+	ip = nspcb.nsp_next;
+	if (ip == 0) {
+		splx(s);
+		return;
+	}
+	while (ip != &nspcb) {
+		cb = nstosppcb(ip);
+		ipnxt = ip->nsp_next;
+		if (cb == 0)
+			goto tpgone;
+		for (i = 0; i < SPPT_NTIMERS; i++) {
+			if (cb->s_timer[i] && --cb->s_timer[i] == 0) {
+				(void) spp_usrreq(cb->s_nspcb->nsp_socket,
+				    PRU_SLOWTIMO, (struct mbuf *)0,
+				    (struct mbuf *)i, (struct mbuf *)0,
+				    (struct mbuf *)0);
+				if (ipnxt->nsp_prev != ip)
+					goto tpgone;
+			}
+		}
+		cb->s_idle++;
+		if (cb->s_rtt)
+			cb->s_rtt++;
+tpgone:
+		ip = ipnxt;
+	}
+	spp_iss += SPP_ISSINCR/PR_SLOWHZ;		/* increment iss */
+	splx(s);
+}
+/*
+ * SPP timer processing.
+ */
+struct sppcb *
+spp_timers(cb, timer)
+	register struct sppcb *cb;
+	long timer;
+{
+	long rexmt;
+	int win;
+
+	cb->s_force = 1 + timer;
+	switch (timer) {
+
+	/*
+	 * 2 MSL timeout in shutdown went off.  TCP deletes connection
+	 * control block.
+	 */
+	case SPPT_2MSL:
+		printf("spp: SPPT_2MSL went off for no reason\n");
+		cb->s_timer[timer] = 0;
+		break;
+
+	/*
+	 * Retransmission timer went off.  Message has not
+	 * been acked within retransmit interval.  Back off
+	 * to a longer retransmit interval and retransmit one packet.
+	 */
+	case SPPT_REXMT:
+		if (++cb->s_rxtshift > SPP_MAXRXTSHIFT) {
+			cb->s_rxtshift = SPP_MAXRXTSHIFT;
+			sppstat.spps_timeoutdrop++;
+			cb = spp_drop(cb, ETIMEDOUT);
+			break;
+		}
+		sppstat.spps_rexmttimeo++;
+		rexmt = ((cb->s_srtt >> 2) + cb->s_rttvar) >> 1;
+		rexmt *= spp_backoff[cb->s_rxtshift];
+		SPPT_RANGESET(cb->s_rxtcur, rexmt, SPPTV_MIN, SPPTV_REXMTMAX);
+		cb->s_timer[SPPT_REXMT] = cb->s_rxtcur;
+		/*
+		 * If we have backed off fairly far, our srtt
+		 * estimate is probably bogus.  Clobber it
+		 * so we'll take the next rtt measurement as our srtt;
+		 * move the current srtt into rttvar to keep the current
+		 * retransmit times until then.
+		 */
+		if (cb->s_rxtshift > SPP_MAXRXTSHIFT / 4 ) {
+			cb->s_rttvar += (cb->s_srtt >> 2);
+			cb->s_srtt = 0;
+		}
+		cb->s_snxt = cb->s_rack;
+		/*
+		 * If timing a packet, stop the timer.
+		 */
+		cb->s_rtt = 0;
+		/*
+		 * See very long discussion in tcp_timer.c about congestion
+		 * window and sstrhesh
+		 */
+		win = min(cb->s_swnd, (cb->s_cwnd/CUNIT)) / 2;
+		if (win < 2)
+			win = 2;
+		cb->s_cwnd = CUNIT;
+		cb->s_ssthresh = win * CUNIT;
+		(void) spp_output(cb, (struct mbuf *) 0);
+		break;
+
+	/*
+	 * Persistance timer into zero window.
+	 * Force a probe to be sent.
+	 */
+	case SPPT_PERSIST:
+		sppstat.spps_persisttimeo++;
+		spp_setpersist(cb);
+		(void) spp_output(cb, (struct mbuf *) 0);
+		break;
+
+	/*
+	 * Keep-alive timer went off; send something
+	 * or drop connection if idle for too long.
+	 */
+	case SPPT_KEEP:
+		sppstat.spps_keeptimeo++;
+		if (cb->s_state < TCPS_ESTABLISHED)
+			goto dropit;
+		if (cb->s_nspcb->nsp_socket->so_options & SO_KEEPALIVE) {
+		    	if (cb->s_idle >= SPPTV_MAXIDLE)
+				goto dropit;
+			sppstat.spps_keepprobe++;
+			(void) spp_output(cb, (struct mbuf *) 0);
+		} else
+			cb->s_idle = 0;
+		cb->s_timer[SPPT_KEEP] = SPPTV_KEEP;
+		break;
+	dropit:
+		sppstat.spps_keepdrops++;
+		cb = spp_drop(cb, ETIMEDOUT);
+		break;
+	}
+	return (cb);
+}
+#ifndef lint
+int SppcbSize = sizeof (struct sppcb);
+int NspcbSize = sizeof (struct nspcb);
+#endif /* lint */
diff --git a/sys/netns/spp_var.h b/sys/netns/spp_var.h
new file mode 100644
index 00000000000..51104d4f7d5
--- /dev/null
+++ b/sys/netns/spp_var.h
@@ -0,0 +1,217 @@
+/*	$NetBSD: spp_var.h,v 1.5 1995/03/26 20:36:23 jtc Exp $	*/
+
+/*
+ * Copyright (c) 1984, 1985, 1986, 1987, 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.
+ *
+ *	@(#)spp_var.h	8.1 (Berkeley) 6/10/93
+ */
+
+/*
+ * Sp control block, one per connection
+ */
+struct sppcb {
+	struct	spidp_q	s_q;		/* queue for out-of-order receipt */
+	struct	nspcb	*s_nspcb;	/* backpointer to internet pcb */
+	u_char	s_state;
+	u_char	s_flags;
+#define	SF_ACKNOW	0x01		/* Ack peer immediately */
+#define	SF_DELACK	0x02		/* Ack, but try to delay it */
+#define	SF_HI	0x04			/* Show headers on input */
+#define	SF_HO	0x08			/* Show headers on output */
+#define	SF_PI	0x10			/* Packet (datagram) interface */
+#define SF_WIN	0x20			/* Window info changed */
+#define SF_RXT	0x40			/* Rxt info changed */
+#define SF_RVD	0x80			/* Calling from read usrreq routine */
+	u_short s_mtu;			/* Max packet size for this stream */
+/* use sequence fields in headers to store sequence numbers for this
+   connection */
+	struct	idp	*s_idp;
+	struct	sphdr	s_shdr;		/* prototype header to transmit */
+#define s_cc s_shdr.sp_cc		/* connection control (for EM bit) */
+#define s_dt s_shdr.sp_dt		/* datastream type */
+#define s_sid s_shdr.sp_sid		/* source connection identifier */
+#define s_did s_shdr.sp_did		/* destination connection identifier */
+#define s_seq s_shdr.sp_seq		/* sequence number */
+#define s_ack s_shdr.sp_ack		/* acknowledge number */
+#define s_alo s_shdr.sp_alo		/* allocation number */
+#define s_dport s_idp->idp_dna.x_port	/* where we are sending */
+	struct sphdr s_rhdr;		/* last received header (in effect!)*/
+	u_short s_rack;			/* their acknowledge number */
+	u_short s_ralo;			/* their allocation number */
+	u_short s_smax;			/* highest packet # we have sent */
+	u_short	s_snxt;			/* which packet to send next */
+
+/* congestion control */
+#define	CUNIT	1024			/* scaling for ... */
+	int	s_cwnd;			/* Congestion-controlled window */
+					/* in packets * CUNIT */
+	short	s_swnd;			/* == tcp snd_wnd, in packets */
+	short	s_smxw;			/* == tcp max_sndwnd */
+					/* difference of two spp_seq's can be
+					   no bigger than a short */
+	u_short	s_swl1;			/* == tcp snd_wl1 */
+	u_short	s_swl2;			/* == tcp snd_wl2 */
+	int	s_cwmx;			/* max allowable cwnd */
+	int	s_ssthresh;		/* s_cwnd size threshhold for
+					 * slow start exponential-to-
+					 * linear switch */
+/* transmit timing stuff
+ * srtt and rttvar are stored as fixed point, for convenience in smoothing.
+ * srtt has 3 bits to the right of the binary point, rttvar has 2.
+ */
+	short	s_idle;			/* time idle */
+	short	s_timer[SPPT_NTIMERS];	/* timers */
+	short	s_rxtshift;		/* log(2) of rexmt exp. backoff */
+	short	s_rxtcur;		/* current retransmit value */
+	u_short	s_rtseq;		/* packet being timed */
+	short	s_rtt;			/* timer for round trips */
+	short	s_srtt;			/* averaged timer */
+	short	s_rttvar;		/* variance in round trip time */
+	char	s_force;		/* which timer expired */
+	char	s_dupacks;		/* counter to intuit xmt loss */
+
+/* out of band data */
+	char	s_oobflags;
+#define SF_SOOB	0x08			/* sending out of band data */
+#define SF_IOOB 0x10			/* receiving out of band data */
+	char	s_iobc;			/* input characters */
+/* debug stuff */
+	u_short	s_want;			/* Last candidate for sending */
+	char	s_outx;			/* exit taken from spp_output */
+	char	s_inx;			/* exit taken from spp_input */
+	u_short	s_flags2;		/* more flags for testing */
+#define SF_NEWCALL	0x100		/* for new_recvmsg */
+#define SO_NEWCALL	10		/* for new_recvmsg */
+};
+
+#define	nstosppcb(np)	((struct sppcb *)(np)->nsp_pcb)
+#define	sotosppcb(so)	(nstosppcb(sotonspcb(so)))
+
+struct	sppstat {
+	long	spps_connattempt;	/* connections initiated */
+	long	spps_accepts;		/* connections accepted */
+	long	spps_connects;		/* connections established */
+	long	spps_drops;		/* connections dropped */
+	long	spps_conndrops;		/* embryonic connections dropped */
+	long	spps_closed;		/* conn. closed (includes drops) */
+	long	spps_segstimed;		/* segs where we tried to get rtt */
+	long	spps_rttupdated;	/* times we succeeded */
+	long	spps_delack;		/* delayed acks sent */
+	long	spps_timeoutdrop;	/* conn. dropped in rxmt timeout */
+	long	spps_rexmttimeo;	/* retransmit timeouts */
+	long	spps_persisttimeo;	/* persist timeouts */
+	long	spps_keeptimeo;		/* keepalive timeouts */
+	long	spps_keepprobe;		/* keepalive probes sent */
+	long	spps_keepdrops;		/* connections dropped in keepalive */
+
+	long	spps_sndtotal;		/* total packets sent */
+	long	spps_sndpack;		/* data packets sent */
+	long	spps_sndbyte;		/* data bytes sent */
+	long	spps_sndrexmitpack;	/* data packets retransmitted */
+	long	spps_sndrexmitbyte;	/* data bytes retransmitted */
+	long	spps_sndacks;		/* ack-only packets sent */
+	long	spps_sndprobe;		/* window probes sent */
+	long	spps_sndurg;		/* packets sent with URG only */
+	long	spps_sndwinup;		/* window update-only packets sent */
+	long	spps_sndctrl;		/* control (SYN|FIN|RST) packets sent */
+	long	spps_sndvoid;		/* couldn't find requested packet*/
+
+	long	spps_rcvtotal;		/* total packets received */
+	long	spps_rcvpack;		/* packets received in sequence */
+	long	spps_rcvbyte;		/* bytes received in sequence */
+	long	spps_rcvbadsum;		/* packets received with ccksum errs */
+	long	spps_rcvbadoff;		/* packets received with bad offset */
+	long	spps_rcvshort;		/* packets received too short */
+	long	spps_rcvduppack;	/* duplicate-only packets received */
+	long	spps_rcvdupbyte;	/* duplicate-only bytes received */
+	long	spps_rcvpartduppack;	/* packets with some duplicate data */
+	long	spps_rcvpartdupbyte;	/* dup. bytes in part-dup. packets */
+	long	spps_rcvoopack;		/* out-of-order packets received */
+	long	spps_rcvoobyte;		/* out-of-order bytes received */
+	long	spps_rcvpackafterwin;	/* packets with data after window */
+	long	spps_rcvbyteafterwin;	/* bytes rcvd after window */
+	long	spps_rcvafterclose;	/* packets rcvd after "close" */
+	long	spps_rcvwinprobe;	/* rcvd window probe packets */
+	long	spps_rcvdupack;		/* rcvd duplicate acks */
+	long	spps_rcvacktoomuch;	/* rcvd acks for unsent data */
+	long	spps_rcvackpack;	/* rcvd ack packets */
+	long	spps_rcvackbyte;	/* bytes acked by rcvd acks */
+	long	spps_rcvwinupd;		/* rcvd window update packets */
+};
+struct	spp_istat {
+	short	hdrops;
+	short	badsum;
+	short	badlen;
+	short	slotim;
+	short	fastim;
+	short	nonucn;
+	short	noconn;
+	short	notme;
+	short	wrncon;
+	short	bdreas;
+	short	gonawy;
+	short	notyet;
+	short	lstdup;
+	struct sppstat newstats;
+};
+
+#ifdef _KERNEL
+struct spp_istat spp_istat;
+
+/* Following was struct sppstat sppstat; */
+#ifndef sppstat
+#define sppstat spp_istat.newstats
+#endif
+
+u_short spp_iss;
+extern struct sppcb *spp_close(), *spp_disconnect(),
+	*spp_usrclosed(), *spp_timers(), *spp_drop();
+#endif
+
+#define	SPP_ISSINCR	128
+/*
+ * SPP sequence numbers are 16 bit integers operated
+ * on with modular arithmetic.  These macros can be
+ * used to compare such integers.
+ */
+#ifdef sun
+short xnsCbug;
+#define	SSEQ_LT(a,b)	((xnsCbug = (short)((a)-(b))) < 0)
+#define	SSEQ_LEQ(a,b)	((xnsCbug = (short)((a)-(b))) <= 0)
+#define	SSEQ_GT(a,b)	((xnsCbug = (short)((a)-(b))) > 0)
+#define	SSEQ_GEQ(a,b)	((xnsCbug = (short)((a)-(b))) >= 0)
+#else
+#define	SSEQ_LT(a,b)	(((short)((a)-(b))) < 0)
+#define	SSEQ_LEQ(a,b)	(((short)((a)-(b))) <= 0)
+#define	SSEQ_GT(a,b)	(((short)((a)-(b))) > 0)
+#define	SSEQ_GEQ(a,b)	(((short)((a)-(b))) >= 0)
+#endif