new file mode 100644
--- /dev/null
+++ b/packages/net/bsd_tcpip/current/src/sys/netinet/tcp_usrreq.c
@@ -0,0 +1,1126 @@
+//==========================================================================
+//
+//      src/sys/netinet/tcp_usrreq.c
+//
+//==========================================================================
+//####BSDCOPYRIGHTBEGIN####
+//
+// -------------------------------------------
+//
+// Portions of this software may have been derived from OpenBSD, 
+// FreeBSD or other sources, and are covered by the appropriate
+// copyright disclaimers included herein.
+//
+// Portions created by Red Hat are
+// Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+//
+// -------------------------------------------
+//
+//####BSDCOPYRIGHTEND####
+//==========================================================================
+
+/*
+ * 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.
+ *
+ *	From: @(#)tcp_usrreq.c	8.2 (Berkeley) 1/3/94
+ * $FreeBSD: src/sys/netinet/tcp_usrreq.c,v 1.51.2.9 2001/08/22 00:59:12 silby Exp $
+ */
+
+#include <sys/param.h>
+#include <sys/mbuf.h>
+#ifdef INET6
+#include <sys/domain.h>
+#endif /* INET6 */
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/protosw.h>
+
+#include <net/if.h>
+#include <net/route.h>
+
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#ifdef INET6
+#include <netinet/ip6.h>
+#endif
+#include <netinet/in_pcb.h>
+#ifdef INET6
+#include <netinet6/in6_pcb.h>
+#endif
+#include <netinet/in_var.h>
+#include <netinet/ip_var.h>
+#ifdef INET6
+#include <netinet6/ip6_var.h>
+#endif
+#include <netinet/tcp.h>
+#include <netinet/tcp_fsm.h>
+#include <netinet/tcp_seq.h>
+#include <netinet/tcp_timer.h>
+#include <netinet/tcp_var.h>
+#include <netinet/tcpip.h>
+#ifdef TCPDEBUG
+#include <netinet/tcp_debug.h>
+#endif
+
+#ifdef IPSEC
+#include <netinet6/ipsec.h>
+#endif /*IPSEC*/
+
+/*
+ * TCP protocol interface to socket abstraction.
+ */
+extern	char *tcpstates[];	/* XXX ??? */
+
+static int	tcp_attach __P((struct socket *, struct proc *));
+static int	tcp_connect __P((struct tcpcb *, struct sockaddr *, 
+				 struct proc *));
+#ifdef INET6
+static int	tcp6_connect __P((struct tcpcb *, struct sockaddr *,
+				 struct proc *));
+#endif /* INET6 */
+static struct tcpcb *
+		tcp_disconnect __P((struct tcpcb *));
+static struct tcpcb *
+		tcp_usrclosed __P((struct tcpcb *));
+
+#ifdef TCPDEBUG
+#define	TCPDEBUG0	int ostate = 0
+#define	TCPDEBUG1()	ostate = tp ? tp->t_state : 0
+#define	TCPDEBUG2(req)	if (tp && (so->so_options & SO_DEBUG)) \
+				tcp_trace(TA_USER, ostate, tp, 0, 0, req)
+#else
+#define	TCPDEBUG0
+#define	TCPDEBUG1()
+#define	TCPDEBUG2(req)
+#endif
+
+/*
+ * TCP attaches to socket via pru_attach(), reserving space,
+ * and an internet control block.
+ */
+static int
+tcp_usr_attach(struct socket *so, int proto, struct proc *p)
+{
+	int s = splnet();
+	int error;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp = 0;
+	TCPDEBUG0;
+
+	TCPDEBUG1();
+	if (inp) {
+		error = EISCONN;
+		goto out;
+	}
+
+	error = tcp_attach(so, p);
+	if (error)
+		goto out;
+
+	if ((so->so_options & SO_LINGER) && so->so_linger == 0)
+		so->so_linger = TCP_LINGERTIME;
+	tp = sototcpcb(so);
+out:
+	TCPDEBUG2(PRU_ATTACH);
+	splx(s);
+	return error;
+}
+
+/*
+ * pru_detach() detaches the TCP protocol from the socket.
+ * If the protocol state is non-embryonic, then can't
+ * do this directly: have to initiate a pru_disconnect(),
+ * which may finish later; embryonic TCB's can just
+ * be discarded here.
+ */
+static int
+tcp_usr_detach(struct socket *so)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+	TCPDEBUG0;
+
+	if (inp == 0) {
+		splx(s);
+		return EINVAL;	/* XXX */
+	}
+	tp = intotcpcb(inp);
+	TCPDEBUG1();
+	tp = tcp_disconnect(tp);
+
+	TCPDEBUG2(PRU_DETACH);
+	splx(s);
+	return error;
+}
+
+#define	COMMON_START()	TCPDEBUG0; \
+			do { \
+				     if (inp == 0) { \
+					     splx(s); \
+					     return EINVAL; \
+				     } \
+				     tp = intotcpcb(inp); \
+				     TCPDEBUG1(); \
+		     } while(0)
+			     
+#define COMMON_END(req)	out: TCPDEBUG2(req); splx(s); return error; goto out
+
+
+/*
+ * Give the socket an address.
+ */
+static int
+tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+	struct sockaddr_in *sinp;
+
+	COMMON_START();
+
+	/*
+	 * Must check for multicast addresses and disallow binding
+	 * to them.
+	 */
+	sinp = (struct sockaddr_in *)nam;
+	if (sinp->sin_family == AF_INET &&
+	    IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
+		error = EAFNOSUPPORT;
+		goto out;
+	}
+	error = in_pcbbind(inp, nam, p);
+	if (error)
+		goto out;
+	COMMON_END(PRU_BIND);
+
+}
+
+#ifdef INET6
+static int
+tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+	struct sockaddr_in6 *sin6p;
+
+	COMMON_START();
+
+	/*
+	 * Must check for multicast addresses and disallow binding
+	 * to them.
+	 */
+	sin6p = (struct sockaddr_in6 *)nam;
+	if (sin6p->sin6_family == AF_INET6 &&
+	    IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
+		error = EAFNOSUPPORT;
+		goto out;
+	}
+	inp->inp_vflag &= ~INP_IPV4;
+	inp->inp_vflag |= INP_IPV6;
+	if (ip6_mapped_addr_on && (inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
+		if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
+			inp->inp_vflag |= INP_IPV4;
+		else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
+			struct sockaddr_in sin;
+
+			in6_sin6_2_sin(&sin, sin6p);
+			inp->inp_vflag |= INP_IPV4;
+			inp->inp_vflag &= ~INP_IPV6;
+			error = in_pcbbind(inp, (struct sockaddr *)&sin, p);
+			goto out;
+		}
+	}
+	error = in6_pcbbind(inp, nam, p);
+	if (error)
+		goto out;
+	COMMON_END(PRU_BIND);
+}
+#endif /* INET6 */
+
+/*
+ * Prepare to accept connections.
+ */
+static int
+tcp_usr_listen(struct socket *so, struct proc *p)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	if (inp->inp_lport == 0)
+		error = in_pcbbind(inp, (struct sockaddr *)0, p);
+	if (error == 0)
+		tp->t_state = TCPS_LISTEN;
+	COMMON_END(PRU_LISTEN);
+}
+
+#ifdef INET6
+static int
+tcp6_usr_listen(struct socket *so, struct proc *p)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	if (inp->inp_lport == 0) {
+		inp->inp_vflag &= ~INP_IPV4;
+		if (ip6_mapped_addr_on &&
+		    (inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
+			inp->inp_vflag |= INP_IPV4;
+		error = in6_pcbbind(inp, (struct sockaddr *)0, p);
+	}
+	if (error == 0)
+		tp->t_state = TCPS_LISTEN;
+	COMMON_END(PRU_LISTEN);
+}
+#endif /* INET6 */
+
+/*
+ * Initiate connection to peer.
+ * Create a template for use in transmissions on this connection.
+ * Enter SYN_SENT state, and mark socket as connecting.
+ * Start keep-alive timer, and seed output sequence space.
+ * Send initial segment on connection.
+ */
+static int
+tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+	struct sockaddr_in *sinp;
+
+	COMMON_START();
+
+	/*
+	 * Must disallow TCP ``connections'' to multicast addresses.
+	 */
+	sinp = (struct sockaddr_in *)nam;
+	if (sinp->sin_family == AF_INET
+	    && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
+		error = EAFNOSUPPORT;
+		goto out;
+	}
+
+
+	if ((error = tcp_connect(tp, nam, p)) != 0)
+		goto out;
+	error = tcp_output(tp);
+	COMMON_END(PRU_CONNECT);
+}
+
+#ifdef INET6
+static int
+tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+	struct sockaddr_in6 *sin6p;
+
+	COMMON_START();
+
+	/*
+	 * Must disallow TCP ``connections'' to multicast addresses.
+	 */
+	sin6p = (struct sockaddr_in6 *)nam;
+	if (sin6p->sin6_family == AF_INET6
+	    && IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
+		error = EAFNOSUPPORT;
+		goto out;
+	}
+
+	if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
+		struct sockaddr_in sin;
+
+		if (!ip6_mapped_addr_on ||
+		    (inp->inp_flags & IN6P_IPV6_V6ONLY))
+			return(EINVAL);
+
+		in6_sin6_2_sin(&sin, sin6p);
+		inp->inp_vflag |= INP_IPV4;
+		inp->inp_vflag &= ~INP_IPV6;
+		if ((error = tcp_connect(tp, (struct sockaddr *)&sin, p)) != 0)
+			goto out;
+		error = tcp_output(tp);
+		goto out;
+	}
+	inp->inp_vflag &= ~INP_IPV4;
+	inp->inp_vflag |= INP_IPV6;
+	if ((error = tcp6_connect(tp, nam, p)) != 0)
+		goto out;
+	error = tcp_output(tp);
+	COMMON_END(PRU_CONNECT);
+}
+#endif /* INET6 */
+
+/*
+ * Initiate disconnect from peer.
+ * If connection never passed embryonic stage, just drop;
+ * else if don't need to let data drain, then can just drop anyways,
+ * else have to begin TCP shutdown process: mark socket disconnecting,
+ * drain unread data, state switch to reflect user close, and
+ * send segment (e.g. FIN) to peer.  Socket will be really disconnected
+ * when peer sends FIN and acks ours.
+ *
+ * SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
+ */
+static int
+tcp_usr_disconnect(struct socket *so)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	tp = tcp_disconnect(tp);
+	COMMON_END(PRU_DISCONNECT);
+}
+
+/*
+ * Accept a connection.  Essentially all the work is
+ * done at higher levels; just return the address
+ * of the peer, storing through addr.
+ */
+static int
+tcp_usr_accept(struct socket *so, struct sockaddr **nam)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp = NULL;
+	TCPDEBUG0;
+
+	if (so->so_state & SS_ISDISCONNECTED) {
+		error = ECONNABORTED;
+		goto out;
+	}
+	if (inp == 0) {
+		splx(s);
+		return (EINVAL);
+	}
+	tp = intotcpcb(inp);
+	TCPDEBUG1();
+	in_setpeeraddr(so, nam);
+	COMMON_END(PRU_ACCEPT);
+}
+
+#ifdef INET6
+static int
+tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp = NULL;
+	TCPDEBUG0;
+
+	if (so->so_state & SS_ISDISCONNECTED) {
+		error = ECONNABORTED;
+		goto out;
+	}
+	if (inp == 0) {
+		splx(s);
+		return (EINVAL);
+	}
+	tp = intotcpcb(inp);
+	TCPDEBUG1();
+	in6_mapped_peeraddr(so, nam);
+	COMMON_END(PRU_ACCEPT);
+}
+#endif /* INET6 */
+/*
+ * Mark the connection as being incapable of further output.
+ */
+static int
+tcp_usr_shutdown(struct socket *so)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	socantsendmore(so);
+	tp = tcp_usrclosed(tp);
+	if (tp)
+		error = tcp_output(tp);
+	COMMON_END(PRU_SHUTDOWN);
+}
+
+/*
+ * After a receive, possibly send window update to peer.
+ */
+static int
+tcp_usr_rcvd(struct socket *so, int flags)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	tcp_output(tp);
+	COMMON_END(PRU_RCVD);
+}
+
+/*
+ * Do a send by putting data in output queue and updating urgent
+ * marker if URG set.  Possibly send more data.  Unlike the other
+ * pru_*() routines, the mbuf chains are our responsibility.  We
+ * must either enqueue them or free them.  The other pru_* routines
+ * generally are caller-frees.
+ */
+static int
+tcp_usr_send(struct socket *so, int flags, struct mbuf *m, 
+	     struct sockaddr *nam, struct mbuf *control, struct proc *p)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+#ifdef INET6
+	int isipv6;
+#endif
+	TCPDEBUG0;
+
+	if (inp == NULL) {
+		/*
+		 * OOPS! we lost a race, the TCP session got reset after
+		 * we checked SS_CANTSENDMORE, eg: while doing uiomove or a
+		 * network interrupt in the non-splnet() section of sosend().
+		 */
+		if (m)
+			m_freem(m);
+		if (control)
+			m_freem(control);
+		error = ECONNRESET;	/* XXX EPIPE? */
+		tp = NULL;
+		TCPDEBUG1();
+		goto out;
+	}
+#ifdef INET6
+	isipv6 = nam && nam->sa_family == AF_INET6;
+#endif /* INET6 */
+	tp = intotcpcb(inp);
+	TCPDEBUG1();
+	if (control) {
+		/* TCP doesn't do control messages (rights, creds, etc) */
+		if (control->m_len) {
+			m_freem(control);
+			if (m)
+				m_freem(m);
+			error = EINVAL;
+			goto out;
+		}
+		m_freem(control);	/* empty control, just free it */
+	}
+	if(!(flags & PRUS_OOB)) {
+		sbappend(&so->so_snd, m);
+		if (nam && tp->t_state < TCPS_SYN_SENT) {
+			/*
+			 * Do implied connect if not yet connected,
+			 * initialize window to default value, and
+			 * initialize maxseg/maxopd using peer's cached
+			 * MSS.
+			 */
+#ifdef INET6
+			if (isipv6)
+				error = tcp6_connect(tp, nam, p);
+			else
+#endif /* INET6 */
+			error = tcp_connect(tp, nam, p);
+			if (error)
+				goto out;
+			tp->snd_wnd = TTCP_CLIENT_SND_WND;
+			tcp_mss(tp, -1);
+		}
+
+		if (flags & PRUS_EOF) {
+			/*
+			 * Close the send side of the connection after
+			 * the data is sent.
+			 */
+			socantsendmore(so);
+			tp = tcp_usrclosed(tp);
+		}
+		if (tp != NULL) {
+			if (flags & PRUS_MORETOCOME)
+				tp->t_flags |= TF_MORETOCOME;
+			error = tcp_output(tp);
+			if (flags & PRUS_MORETOCOME)
+				tp->t_flags &= ~TF_MORETOCOME;
+		}
+	} else {
+		if (sbspace(&so->so_snd) < -512) {
+			m_freem(m);
+			error = ENOBUFS;
+			goto out;
+		}
+		/*
+		 * According to RFC961 (Assigned Protocols),
+		 * the urgent pointer points to the last octet
+		 * of urgent data.  We continue, however,
+		 * to consider it to indicate the first octet
+		 * of data past the urgent section.
+		 * Otherwise, snd_up should be one lower.
+		 */
+		sbappend(&so->so_snd, m);
+		if (nam && tp->t_state < TCPS_SYN_SENT) {
+			/*
+			 * Do implied connect if not yet connected,
+			 * initialize window to default value, and
+			 * initialize maxseg/maxopd using peer's cached
+			 * MSS.
+			 */
+#ifdef INET6
+			if (isipv6)
+				error = tcp6_connect(tp, nam, p);
+			else
+#endif /* INET6 */
+			error = tcp_connect(tp, nam, p);
+			if (error)
+				goto out;
+			tp->snd_wnd = TTCP_CLIENT_SND_WND;
+			tcp_mss(tp, -1);
+		}
+		tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
+		tp->t_force = 1;
+		error = tcp_output(tp);
+		tp->t_force = 0;
+	}
+	COMMON_END((flags & PRUS_OOB) ? PRU_SENDOOB : 
+		   ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
+}
+
+/*
+ * Abort the TCP.
+ */
+static int
+tcp_usr_abort(struct socket *so)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	tp = tcp_drop(tp, ECONNABORTED);
+	COMMON_END(PRU_ABORT);
+}
+
+/*
+ * Receive out-of-band data.
+ */
+static int
+tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
+{
+	int s = splnet();
+	int error = 0;
+	struct inpcb *inp = sotoinpcb(so);
+	struct tcpcb *tp;
+
+	COMMON_START();
+	if ((so->so_oobmark == 0 &&
+	     (so->so_state & SS_RCVATMARK) == 0) ||
+	    so->so_options & SO_OOBINLINE ||
+	    tp->t_oobflags & TCPOOB_HADDATA) {
+		error = EINVAL;
+		goto out;
+	}
+	if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
+		error = EWOULDBLOCK;
+		goto out;
+	}
+	m->m_len = 1;
+	*mtod(m, caddr_t) = tp->t_iobc;
+	if ((flags & MSG_PEEK) == 0)
+		tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
+	COMMON_END(PRU_RCVOOB);
+}
+
+/* xxx - should be const */
+struct pr_usrreqs tcp_usrreqs = {
+	tcp_usr_abort, tcp_usr_accept, tcp_usr_attach, tcp_usr_bind,
+	tcp_usr_connect, pru_connect2_notsupp, in_control, tcp_usr_detach,
+	tcp_usr_disconnect, tcp_usr_listen, in_setpeeraddr, tcp_usr_rcvd,
+	tcp_usr_rcvoob, tcp_usr_send, pru_sense_null, tcp_usr_shutdown,
+	in_setsockaddr, sosend, soreceive, sopoll
+};
+
+#ifdef INET6
+struct pr_usrreqs tcp6_usrreqs = {
+	tcp_usr_abort, tcp6_usr_accept, tcp_usr_attach, tcp6_usr_bind,
+	tcp6_usr_connect, pru_connect2_notsupp, in6_control, tcp_usr_detach,
+	tcp_usr_disconnect, tcp6_usr_listen, in6_mapped_peeraddr, tcp_usr_rcvd,
+	tcp_usr_rcvoob, tcp_usr_send, pru_sense_null, tcp_usr_shutdown,
+	in6_mapped_sockaddr, sosend, soreceive, sopoll
+};
+#endif /* INET6 */
+
+/*
+ * Common subroutine to open a TCP connection to remote host specified
+ * by struct sockaddr_in in mbuf *nam.  Call in_pcbbind to assign a local
+ * port number if needed.  Call in_pcbladdr to do the routing and to choose
+ * a local host address (interface).  If there is an existing incarnation
+ * of the same connection in TIME-WAIT state and if the remote host was
+ * sending CC options and if the connection duration was < MSL, then
+ * truncate the previous TIME-WAIT state and proceed.
+ * Initialize connection parameters and enter SYN-SENT state.
+ */
+static int
+tcp_connect(tp, nam, p)
+	register struct tcpcb *tp;
+	struct sockaddr *nam;
+	struct proc *p;
+{
+	struct inpcb *inp = tp->t_inpcb, *oinp;
+	struct socket *so = inp->inp_socket;
+	struct tcpcb *otp;
+	struct sockaddr_in *sin = (struct sockaddr_in *)nam;
+	struct sockaddr_in *ifaddr;
+	struct rmxp_tao *taop;
+	struct rmxp_tao tao_noncached;
+	int error;
+
+	if (inp->inp_lport == 0) {
+		error = in_pcbbind(inp, (struct sockaddr *)0, p);
+		if (error)
+			return error;
+	}
+
+	/*
+	 * Cannot simply call in_pcbconnect, because there might be an
+	 * earlier incarnation of this same connection still in
+	 * TIME_WAIT state, creating an ADDRINUSE error.
+	 */
+	error = in_pcbladdr(inp, nam, &ifaddr);
+	if (error)
+		return error;
+	oinp = in_pcblookup_hash(inp->inp_pcbinfo,
+	    sin->sin_addr, sin->sin_port,
+	    inp->inp_laddr.s_addr != INADDR_ANY ? inp->inp_laddr
+						: ifaddr->sin_addr,
+	    inp->inp_lport,  0, NULL);
+	if (oinp) {
+		if (oinp != inp && (otp = intotcpcb(oinp)) != NULL &&
+		otp->t_state == TCPS_TIME_WAIT &&
+		    (ticks - otp->t_starttime) < tcp_msl &&
+		    (otp->t_flags & TF_RCVD_CC))
+			otp = tcp_close(otp);
+		else
+			return EADDRINUSE;
+	}
+	if (inp->inp_laddr.s_addr == INADDR_ANY)
+		inp->inp_laddr = ifaddr->sin_addr;
+	inp->inp_faddr = sin->sin_addr;
+	inp->inp_fport = sin->sin_port;
+	in_pcbrehash(inp);
+
+	/* Compute window scaling to request.  */
+	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
+	    (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
+		tp->request_r_scale++;
+
+	soisconnecting(so);
+	tcpstat.tcps_connattempt++;
+	tp->t_state = TCPS_SYN_SENT;
+	callout_reset(tp->tt_keep, tcp_keepinit, tcp_timer_keep, tp);
+	tp->iss = tcp_new_isn(tp);
+	tcp_sendseqinit(tp);
+
+	/*
+	 * Generate a CC value for this connection and
+	 * check whether CC or CCnew should be used.
+	 */
+	if ((taop = tcp_gettaocache(tp->t_inpcb)) == NULL) {
+		taop = &tao_noncached;
+		bzero(taop, sizeof(*taop));
+	}
+
+	tp->cc_send = CC_INC(tcp_ccgen);
+	if (taop->tao_ccsent != 0 &&
+	    CC_GEQ(tp->cc_send, taop->tao_ccsent)) {
+		taop->tao_ccsent = tp->cc_send;
+	} else {
+		taop->tao_ccsent = 0;
+		tp->t_flags |= TF_SENDCCNEW;
+	}
+
+	return 0;
+}
+
+#ifdef INET6
+static int
+tcp6_connect(tp, nam, p)
+	register struct tcpcb *tp;
+	struct sockaddr *nam;
+	struct proc *p;
+{
+	struct inpcb *inp = tp->t_inpcb, *oinp;
+	struct socket *so = inp->inp_socket;
+	struct tcpcb *otp;
+	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
+	struct in6_addr *addr6;
+	struct rmxp_tao *taop;
+	struct rmxp_tao tao_noncached;
+	int error;
+
+	if (inp->inp_lport == 0) {
+		error = in6_pcbbind(inp, (struct sockaddr *)0, p);
+		if (error)
+			return error;
+	}
+
+	/*
+	 * Cannot simply call in_pcbconnect, because there might be an
+	 * earlier incarnation of this same connection still in
+	 * TIME_WAIT state, creating an ADDRINUSE error.
+	 */
+	error = in6_pcbladdr(inp, nam, &addr6);
+	if (error)
+		return error;
+	oinp = in6_pcblookup_hash(inp->inp_pcbinfo,
+				  &sin6->sin6_addr, sin6->sin6_port,
+				  IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)
+				  ? addr6
+				  : &inp->in6p_laddr,
+				  inp->inp_lport,  0, NULL);
+	if (oinp) {
+		if (oinp != inp && (otp = intotcpcb(oinp)) != NULL &&
+		    otp->t_state == TCPS_TIME_WAIT &&
+		    (ticks - otp->t_starttime) < tcp_msl &&
+		    (otp->t_flags & TF_RCVD_CC))
+			otp = tcp_close(otp);
+		else
+			return EADDRINUSE;
+	}
+	if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
+		inp->in6p_laddr = *addr6;
+	inp->in6p_faddr = sin6->sin6_addr;
+	inp->inp_fport = sin6->sin6_port;
+	if ((sin6->sin6_flowinfo & IPV6_FLOWINFO_MASK) != (u_int32_t)NULL)
+		inp->in6p_flowinfo = sin6->sin6_flowinfo;
+	in_pcbrehash(inp);
+
+	/* Compute window scaling to request.  */
+	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
+	    (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
+		tp->request_r_scale++;
+
+	soisconnecting(so);
+	tcpstat.tcps_connattempt++;
+	tp->t_state = TCPS_SYN_SENT;
+	callout_reset(tp->tt_keep, tcp_keepinit, tcp_timer_keep, tp);
+	tp->iss = tcp_new_isn(tp);
+	tcp_sendseqinit(tp);
+
+	/*
+	 * Generate a CC value for this connection and
+	 * check whether CC or CCnew should be used.
+	 */
+	if ((taop = tcp_gettaocache(tp->t_inpcb)) == NULL) {
+		taop = &tao_noncached;
+		bzero(taop, sizeof(*taop));
+	}
+
+	tp->cc_send = CC_INC(tcp_ccgen);
+	if (taop->tao_ccsent != 0 &&
+	    CC_GEQ(tp->cc_send, taop->tao_ccsent)) {
+		taop->tao_ccsent = tp->cc_send;
+	} else {
+		taop->tao_ccsent = 0;
+		tp->t_flags |= TF_SENDCCNEW;
+	}
+
+	return 0;
+}
+#endif /* INET6 */
+
+/*
+ * The new sockopt interface makes it possible for us to block in the
+ * copyin/out step (if we take a page fault).  Taking a page fault at
+ * splnet() is probably a Bad Thing.  (Since sockets and pcbs both now
+ * use TSM, there probably isn't any need for this function to run at
+ * splnet() any more.  This needs more examination.)
+ */
+int
+tcp_ctloutput(so, sopt)
+	struct socket *so;
+	struct sockopt *sopt;
+{
+	int	error, opt, optval, s;
+	struct	inpcb *inp;
+	struct	tcpcb *tp;
+
+	error = 0;
+	s = splnet();		/* XXX */
+	inp = sotoinpcb(so);
+	if (inp == NULL) {
+		splx(s);
+		return (ECONNRESET);
+	}
+	if (sopt->sopt_level != IPPROTO_TCP) {
+#ifdef INET6
+		if (INP_CHECK_SOCKAF(so, AF_INET6))
+			error = ip6_ctloutput(so, sopt);
+		else
+#endif /* INET6 */
+		error = ip_ctloutput(so, sopt);
+		splx(s);
+		return (error);
+	}
+	tp = intotcpcb(inp);
+
+	switch (sopt->sopt_dir) {
+	case SOPT_SET:
+		switch (sopt->sopt_name) {
+		case TCP_NODELAY:
+		case TCP_NOOPT:
+		case TCP_NOPUSH:
+			error = sooptcopyin(sopt, &optval, sizeof optval,
+					    sizeof optval);
+			if (error)
+				break;
+
+			switch (sopt->sopt_name) {
+			case TCP_NODELAY:
+				opt = TF_NODELAY;
+				break;
+			case TCP_NOOPT:
+				opt = TF_NOOPT;
+				break;
+			case TCP_NOPUSH:
+				opt = TF_NOPUSH;
+				break;
+			default:
+				opt = 0; /* dead code to fool gcc */
+				break;
+			}
+
+			if (optval)
+				tp->t_flags |= opt;
+			else
+				tp->t_flags &= ~opt;
+			break;
+
+		case TCP_MAXSEG:
+			error = sooptcopyin(sopt, &optval, sizeof optval,
+					    sizeof optval);
+			if (error)
+				break;
+
+			if (optval > 0 && optval <= tp->t_maxseg)
+				tp->t_maxseg = optval;
+			else
+				error = EINVAL;
+			break;
+
+		default:
+			error = ENOPROTOOPT;
+			break;
+		}
+		break;
+
+	case SOPT_GET:
+		switch (sopt->sopt_name) {
+		case TCP_NODELAY:
+			optval = tp->t_flags & TF_NODELAY;
+			break;
+		case TCP_MAXSEG:
+			optval = tp->t_maxseg;
+			break;
+		case TCP_NOOPT:
+			optval = tp->t_flags & TF_NOOPT;
+			break;
+		case TCP_NOPUSH:
+			optval = tp->t_flags & TF_NOPUSH;
+			break;
+		default:
+			error = ENOPROTOOPT;
+			break;
+		}
+		if (error == 0)
+			error = sooptcopyout(sopt, &optval, sizeof optval);
+		break;
+	}
+	splx(s);
+	return (error);
+}
+
+/*
+ * tcp_sendspace and tcp_recvspace are the default send and receive window
+ * sizes, respectively.  These are obsolescent (this information should
+ * be set by the route).
+ */
+u_long	tcp_sendspace = 1024*16;
+u_long	tcp_recvspace = 1024*16;
+
+/*
+ * Attach TCP protocol to socket, allocating
+ * internet protocol control block, tcp control block,
+ * bufer space, and entering LISTEN state if to accept connections.
+ */
+static int
+tcp_attach(so, p)
+	struct socket *so;
+	struct proc *p;
+{
+	register struct tcpcb *tp;
+	struct inpcb *inp;
+	int error;
+#ifdef INET6
+	int isipv6 = INP_CHECK_SOCKAF(so, AF_INET6) != (int)NULL;
+#endif
+
+	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
+		error = soreserve(so, tcp_sendspace, tcp_recvspace);
+		if (error)
+			return (error);
+	}
+	error = in_pcballoc(so, &tcbinfo, p);
+	if (error)
+		return (error);
+	inp = sotoinpcb(so);
+#ifdef INET6
+	if (isipv6) {
+		inp->inp_vflag |= INP_IPV6;
+		inp->in6p_hops = -1;	/* use kernel default */
+	}
+	else
+#endif
+	inp->inp_vflag |= INP_IPV4;
+	tp = tcp_newtcpcb(inp);
+	if (tp == 0) {
+		int nofd = so->so_state & SS_NOFDREF;	/* XXX */
+
+		so->so_state &= ~SS_NOFDREF;	/* don't free the socket yet */
+#ifdef INET6
+		if (isipv6)
+			in6_pcbdetach(inp);
+		else
+#endif
+		in_pcbdetach(inp);
+		so->so_state |= nofd;
+		return (ENOBUFS);
+	}
+	tp->t_state = TCPS_CLOSED;
+	return (0);
+}
+
+/*
+ * Initiate (or continue) disconnect.
+ * If embryonic state, just send reset (once).
+ * If in ``let data drain'' option and linger null, just drop.
+ * Otherwise (hard), mark socket disconnecting and drop
+ * current input data; switch states based on user close, and
+ * send segment to peer (with FIN).
+ */
+static struct tcpcb *
+tcp_disconnect(tp)
+	register struct tcpcb *tp;
+{
+	struct socket *so = tp->t_inpcb->inp_socket;
+
+	if (tp->t_state < TCPS_ESTABLISHED)
+		tp = tcp_close(tp);
+	else if ((so->so_options & SO_LINGER) && so->so_linger == 0)
+		tp = tcp_drop(tp, 0);
+	else {
+		soisdisconnecting(so);
+		sbflush(&so->so_rcv);
+		tp = tcp_usrclosed(tp);
+		if (tp)
+			(void) tcp_output(tp);
+	}
+	return (tp);
+}
+
+/*
+ * User issued close, and wish to trail through shutdown states:
+ * if never received SYN, just forget it.  If got a SYN from peer,
+ * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
+ * If already got a FIN from peer, then almost done; go to LAST_ACK
+ * state.  In all other cases, have already sent FIN to peer (e.g.
+ * after PRU_SHUTDOWN), and just have to play tedious game waiting
+ * for peer to send FIN or not respond to keep-alives, etc.
+ * We can let the user exit from the close as soon as the FIN is acked.
+ */
+static struct tcpcb *
+tcp_usrclosed(tp)
+	register struct tcpcb *tp;
+{
+
+	switch (tp->t_state) {
+
+	case TCPS_CLOSED:
+	case TCPS_LISTEN:
+		tp->t_state = TCPS_CLOSED;
+		tp = tcp_close(tp);
+		break;
+
+	case TCPS_SYN_SENT:
+	case TCPS_SYN_RECEIVED:
+		tp->t_flags |= TF_NEEDFIN;
+		break;
+
+	case TCPS_ESTABLISHED:
+		tp->t_state = TCPS_FIN_WAIT_1;
+		break;
+
+	case TCPS_CLOSE_WAIT:
+		tp->t_state = TCPS_LAST_ACK;
+		break;
+	}
+	if (tp && tp->t_state >= TCPS_FIN_WAIT_2) {
+		soisdisconnected(tp->t_inpcb->inp_socket);
+		/* To prevent the connection hanging in FIN_WAIT_2 forever. */
+		if (tp->t_state == TCPS_FIN_WAIT_2)
+			callout_reset(tp->tt_2msl, tcp_maxidle,
+				      tcp_timer_2msl, tp);
+	}
+	return (tp);
+}
+