/*      $NetBSD: tcp_usrreq.c,v 1.238 2022/11/04 09:01:53 ozaki-r Exp $ */

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

/*-
 * Copyright (c) 1997, 1998, 2005, 2006 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe and Kevin M. Lahey of the Numerical Aerospace Simulation
 * Facility, NASA Ames Research Center.
 * This code is derived from software contributed to The NetBSD Foundation
 * by Charles M. Hannum.
 * This code is derived from software contributed to The NetBSD Foundation
 * by Rui Paulo.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Copyright (c) 1982, 1986, 1988, 1993, 1995
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)tcp_usrreq.c        8.5 (Berkeley) 6/21/95
 */

/*
 * TCP protocol interface to socket abstraction.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: tcp_usrreq.c,v 1.238 2022/11/04 09:01:53 ozaki-r Exp $");

#ifdef _KERNEL_OPT
#include "opt_inet.h"
#include "opt_tcp_debug.h"
#include "opt_mbuftrace.h"
#include "opt_tcp_space.h"
#include "opt_net_mpsafe.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/protosw.h>
#include <sys/errno.h>
#include <sys/stat.h>
#include <sys/proc.h>
#include <sys/domain.h>
#include <sys/sysctl.h>
#include <sys/kauth.h>
#include <sys/kernel.h>
#include <sys/uidinfo.h>

#include <net/if.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/ip_var.h>
#include <netinet/in_offload.h>

#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/ip6_var.h>
#include <netinet6/scope6_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/tcp_private.h>
#include <netinet/tcp_congctl.h>
#include <netinet/tcp_debug.h>
#include <netinet/tcp_vtw.h>
#include <netinet/tcp_syncache.h>

static int
tcp_debug_capture(struct tcpcb *tp, int req)
{
#ifdef TCP_DEBUG
        return tp->t_state;
#endif
        return 0;
}

static inline void
tcp_debug_trace(struct socket *so, struct tcpcb *tp, int ostate, int req)
{
#ifdef TCP_DEBUG
        if (tp && (so->so_options & SO_DEBUG))
                tcp_trace(TA_USER, ostate, tp, NULL, req);
#endif
}

static void
change_keepalive(struct socket *so, struct tcpcb *tp)
{
        tp->t_maxidle = tp->t_keepcnt * MIN(tp->t_keepintvl,
            TCP_TIMER_MAXTICKS / tp->t_keepcnt);
        TCP_TIMER_DISARM(tp, TCPT_KEEP);
        TCP_TIMER_DISARM(tp, TCPT_2MSL);

        if (tp->t_state == TCPS_SYN_RECEIVED ||
            tp->t_state == TCPS_SYN_SENT) {
                TCP_TIMER_ARM(tp, TCPT_KEEP, tp->t_keepinit);
        } else if (so->so_options & SO_KEEPALIVE &&
            tp->t_state <= TCPS_CLOSE_WAIT) {
                TCP_TIMER_ARM(tp, TCPT_KEEP, tp->t_keepintvl);
        } else {
                TCP_TIMER_ARM(tp, TCPT_KEEP, tp->t_keepidle);
        }

        if ((tp->t_state == TCPS_FIN_WAIT_2) && (tp->t_maxidle > 0))
                TCP_TIMER_ARM(tp, TCPT_2MSL, tp->t_maxidle);
}

/*
 * Export TCP internal state information via a struct tcp_info, based on the
 * Linux 2.6 API.  Not ABI compatible as our constants are mapped differently
 * (TCP state machine, etc).  We export all information using FreeBSD-native
 * constants -- for example, the numeric values for tcpi_state will differ
 * from Linux.
 */
static void
tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
{

        bzero(ti, sizeof(*ti));

        ti->tcpi_state = tp->t_state;
        if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
                ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
        if (tp->t_flags & TF_SACK_PERMIT)
                ti->tcpi_options |= TCPI_OPT_SACK;
        if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
                ti->tcpi_options |= TCPI_OPT_WSCALE;
                ti->tcpi_snd_wscale = tp->snd_scale;
                ti->tcpi_rcv_wscale = tp->rcv_scale;
        }
        if (tp->t_flags & TF_ECN_PERMIT) {
                ti->tcpi_options |= TCPI_OPT_ECN;
        }

        ti->tcpi_rto = tp->t_rxtcur * tick;
        ti->tcpi_last_data_recv = (long)(getticks() -
                                         (int)tp->t_rcvtime) * tick;
        ti->tcpi_rtt = ((u_int64_t)tp->t_srtt * tick / PR_SLOWHZ)
                           >> (TCP_RTT_SHIFT + 2);
        ti->tcpi_rttvar = ((u_int64_t)tp->t_rttvar * tick / PR_SLOWHZ)
                           >> (TCP_RTTVAR_SHIFT + 2);

        ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
        /* Linux API wants these in # of segments, apparently */
        ti->tcpi_snd_cwnd = tp->snd_cwnd / tp->t_segsz;
        ti->tcpi_snd_wnd = tp->snd_wnd / tp->t_segsz;

        /*
         * FreeBSD-specific extension fields for tcp_info.
         */
        ti->tcpi_rcv_space = tp->rcv_wnd;
        ti->tcpi_rcv_nxt = tp->rcv_nxt;
        ti->tcpi_snd_bwnd = 0;          /* Unused, kept for compat. */
        ti->tcpi_snd_nxt = tp->snd_nxt;
        ti->tcpi_snd_mss = tp->t_segsz;
        ti->tcpi_rcv_mss = tp->t_segsz;
#ifdef TF_TOE
        if (tp->t_flags & TF_TOE)
                ti->tcpi_options |= TCPI_OPT_TOE;
#endif
        /* From the redundant department of redundancies... */
        ti->__tcpi_retransmits = ti->__tcpi_retrans =
                ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;

        ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
        ti->tcpi_snd_zerowin = tp->t_sndzerowin;
}

int
tcp_ctloutput(int op, struct socket *so, struct sockopt *sopt)
{
        int error = 0, s;
        struct inpcb *inp;
        struct tcpcb *tp;
        struct tcp_info ti;
        u_int ui;
        int family;     /* family of the socket */
        int level, optname, optval;

        level = sopt->sopt_level;
        optname = sopt->sopt_name;

        family = so->so_proto->pr_domain->dom_family;

        s = splsoftnet();
        inp = sotoinpcb(so);
        if (inp == NULL) {
                splx(s);
                return ECONNRESET;
        }
        if (level != IPPROTO_TCP) {
                switch (family) {
                case PF_INET:
                        error = ip_ctloutput(op, so, sopt);
                        break;
#ifdef INET6
                case PF_INET6:
                        error = ip6_ctloutput(op, so, sopt);
                        break;
#endif
                }
                splx(s);
                return error;
        }
        tp = intotcpcb(inp);

        switch (op) {
        case PRCO_SETOPT:
                switch (optname) {
#ifdef TCP_SIGNATURE
                case TCP_MD5SIG:
                        error = sockopt_getint(sopt, &optval);
                        if (error)
                                break;
                        if (optval > 0)
                                tp->t_flags |= TF_SIGNATURE;
                        else
                                tp->t_flags &= ~TF_SIGNATURE;
                        break;
#endif /* TCP_SIGNATURE */

                case TCP_NODELAY:
                        error = sockopt_getint(sopt, &optval);
                        if (error)
                                break;
                        if (optval)
                                tp->t_flags |= TF_NODELAY;
                        else
                                tp->t_flags &= ~TF_NODELAY;
                        break;

                case TCP_MAXSEG:
                        error = sockopt_getint(sopt, &optval);
                        if (error)
                                break;
                        if (optval > 0 && optval <= tp->t_peermss)
                                tp->t_peermss = optval; /* limit on send size */
                        else
                                error = EINVAL;
                        break;
#ifdef notyet
                case TCP_CONGCTL:
                        /* XXX string overflow XXX */
                        error = tcp_congctl_select(tp, sopt->sopt_data);
                        break;
#endif

                case TCP_KEEPIDLE:
                        error = sockopt_get(sopt, &ui, sizeof(ui));
                        if (error)
                                break;
                        if (ui > 0 && ui <= TCP_TIMER_MAXTICKS) {
                                tp->t_keepidle = ui;
                                change_keepalive(so, tp);
                        } else
                                error = EINVAL;
                        break;

                case TCP_KEEPINTVL:
                        error = sockopt_get(sopt, &ui, sizeof(ui));
                        if (error)
                                break;
                        if (ui > 0 && ui <= TCP_TIMER_MAXTICKS) {
                                tp->t_keepintvl = ui;
                                change_keepalive(so, tp);
                        } else
                                error = EINVAL;
                        break;

                case TCP_KEEPCNT:
                        error = sockopt_get(sopt, &ui, sizeof(ui));
                        if (error)
                                break;
                        if (ui > 0 && ui <= TCP_TIMER_MAXTICKS) {
                                tp->t_keepcnt = ui;
                                change_keepalive(so, tp);
                        } else
                                error = EINVAL;
                        break;

                case TCP_KEEPINIT:
                        error = sockopt_get(sopt, &ui, sizeof(ui));
                        if (error)
                                break;
                        if (ui > 0 && ui <= TCP_TIMER_MAXTICKS) {
                                tp->t_keepinit = ui;
                                change_keepalive(so, tp);
                        } else
                                error = EINVAL;
                        break;

                default:
                        error = ENOPROTOOPT;
                        break;
                }
                break;

        case PRCO_GETOPT:
                switch (optname) {
#ifdef TCP_SIGNATURE
                case TCP_MD5SIG:
                        optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
                        goto setval;
#endif
                case TCP_NODELAY:
                        optval = tp->t_flags & TF_NODELAY;
                        goto setval;
                case TCP_MAXSEG:
                        optval = tp->t_peermss;
                        goto setval;
                case TCP_INFO:
                        tcp_fill_info(tp, &ti);
                        error = sockopt_set(sopt, &ti, sizeof ti);
                        break;
#ifdef notyet
                case TCP_CONGCTL:
                        break;
#endif
                case TCP_KEEPIDLE:
                        optval = tp->t_keepidle;
                        goto setval;
                case TCP_KEEPINTVL:
                        optval = tp->t_keepintvl;
                        goto setval;
                case TCP_KEEPCNT:
                        optval = tp->t_keepcnt;
                        goto setval;
                case TCP_KEEPINIT:
                        optval = tp->t_keepinit;
setval:                 error = sockopt_set(sopt, &optval, sizeof(optval));
                        break;
                default:
                        error = ENOPROTOOPT;
                        break;
                }
                break;
        }
        splx(s);
        return error;
}

#ifndef TCP_SENDSPACE
#define TCP_SENDSPACE   1024*32
#endif
int     tcp_sendspace = TCP_SENDSPACE;
#ifndef TCP_RECVSPACE
#define TCP_RECVSPACE   1024*32
#endif
int     tcp_recvspace = TCP_RECVSPACE;

/*
 * tcp_attach: attach TCP protocol to socket, allocating internet protocol
 * control block, TCP control block, buffer space and entering LISTEN state
 * if to accept connections.
 */
static int
tcp_attach(struct socket *so, int proto)
{
        struct tcpcb *tp;
        struct inpcb *inp;
        int s, error, family;

        /* Assign the lock (must happen even if we will error out). */
        s = splsoftnet();
        sosetlock(so);
        KASSERT(solocked(so));
        KASSERT(sotoinpcb(so) == NULL);

        inp = sotoinpcb(so);
        KASSERT(inp == NULL);

        family = soaf(so);

#ifdef MBUFTRACE
        so->so_mowner = &tcp_sock_mowner;
        so->so_rcv.sb_mowner = &tcp_sock_rx_mowner;
        so->so_snd.sb_mowner = &tcp_sock_tx_mowner;
#endif
        if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
                error = soreserve(so, tcp_sendspace, tcp_recvspace);
                if (error)
                        goto out;
        }

        so->so_rcv.sb_flags |= SB_AUTOSIZE;
        so->so_snd.sb_flags |= SB_AUTOSIZE;

        error = inpcb_create(so, &tcbtable);
        if (error)
                goto out;
        inp = sotoinpcb(so);

        tp = tcp_newtcpcb(family, inp);
        if (tp == NULL) {
                int nofd = so->so_state & SS_NOFDREF;   /* XXX */

                so->so_state &= ~SS_NOFDREF;    /* don't free the socket yet */
                inpcb_destroy(inp);
                so->so_state |= nofd;
                error = ENOBUFS;
                goto out;
        }
        tp->t_state = TCPS_CLOSED;
        if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
                so->so_linger = TCP_LINGERTIME;
        }
out:
        KASSERT(solocked(so));
        splx(s);
        return error;
}

static void
tcp_detach(struct socket *so)
{
        struct inpcb *inp;
        struct tcpcb *tp;
        int s;

        inp = sotoinpcb(so);
        if (inp == NULL)
                return;
        tp = intotcpcb(inp);

        s = splsoftnet();
        (void)tcp_disconnect1(tp);
        splx(s);
}

static int
tcp_accept(struct socket *so, struct sockaddr *nam)
{
        struct inpcb *inp;
        struct tcpcb *tp;
        int ostate = 0;
        int s;

        inp = sotoinpcb(so);
        if (inp == NULL)
                return EINVAL;
        tp = intotcpcb(inp);

        ostate = tcp_debug_capture(tp, PRU_ACCEPT);

        /*
         * Accept a connection.  Essentially all the work is
         * done at higher levels; just return the address
         * of the peer, storing through addr.
         */
        s = splsoftnet();
        if (inp->inp_af == AF_INET) {
                inpcb_fetch_peeraddr(inp, (struct sockaddr_in *)nam);
        }
#ifdef INET6
        else if (inp->inp_af == AF_INET6) {
                in6pcb_fetch_peeraddr(inp, (struct sockaddr_in6 *)nam);
        }
#endif
        tcp_debug_trace(so, tp, ostate, PRU_ACCEPT);
        splx(s);

        return 0;
}

static int
tcp_bind(struct socket *so, struct sockaddr *nam, struct lwp *l)
{
        struct inpcb *inp = NULL;
        struct sockaddr_in *sin = (struct sockaddr_in *)nam;
#ifdef INET6
        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
#endif /* INET6 */
        struct tcpcb *tp;
        int s;
        int error = 0;
        int ostate = 0;

        inp = sotoinpcb(so);
        if (inp == NULL)
                return EINVAL;
        tp = intotcpcb(inp);

        ostate = tcp_debug_capture(tp, PRU_BIND);

        /*
         * Give the socket an address.
         */
        s = splsoftnet();
        switch (so->so_proto->pr_domain->dom_family) {
        case PF_INET:
                error = inpcb_bind(inp, sin, l);
                break;
#ifdef INET6
        case PF_INET6:
                error = in6pcb_bind(inp, sin6, l);
                if (!error) {
                        /* mapped addr case */
                        if (IN6_IS_ADDR_V4MAPPED(&in6p_laddr(inp)))
                                tp->t_family = AF_INET;
                        else
                                tp->t_family = AF_INET6;
                }
                break;
#endif
        }
        tcp_debug_trace(so, tp, ostate, PRU_BIND);
        splx(s);

        return error;
}

static int
tcp_listen(struct socket *so, struct lwp *l)
{
        struct inpcb *inp;
        struct tcpcb *tp;
        int error = 0;
        int ostate = 0;
        int s;

        inp = sotoinpcb(so);
        if (inp == NULL)
                return EINVAL;
        tp = intotcpcb(inp);

        ostate = tcp_debug_capture(tp, PRU_LISTEN);

        /*
         * Prepare to accept connections.
         */
        s = splsoftnet();
        if (inp->inp_af == AF_INET && inp->inp_lport == 0) {
                error = inpcb_bind(inp, NULL, l);
                if (error)
                        goto release;
        }
#ifdef INET6
        if (inp->inp_af == AF_INET6 && inp->inp_lport == 0) {
                error = in6pcb_bind(inp, NULL, l);
                if (error)
                        goto release;
        }
#endif
        tp->t_state = TCPS_LISTEN;

release:
        tcp_debug_trace(so, tp, ostate, PRU_LISTEN);
        splx(s);

        return error;
}

static int
tcp_connect(struct socket *so, struct sockaddr *nam, struct lwp *l)
{
        struct inpcb *inp;
        struct tcpcb *tp;
        int s;
        int error = 0;
        int ostate = 0;

        inp = sotoinpcb(so);
        if (inp == NULL)
                return EINVAL;
        tp = intotcpcb(inp);

        ostate = tcp_debug_capture(tp, PRU_CONNECT);

        /*
         * 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.
         */
        s = splsoftnet();

        if (inp->inp_af == AF_INET) {
                if (inp->inp_lport == 0) {
                        error = inpcb_bind(inp, NULL, l);
                        if (error)
                                goto release;
                }
                error = inpcb_connect(inp, (struct sockaddr_in *)nam, l);
        }
#ifdef INET6
        if (inp->inp_af == AF_INET6) {
                if (inp->inp_lport == 0) {
                        error = in6pcb_bind(inp, NULL, l);
                        if (error)
                                goto release;
                }
                error = in6pcb_connect(inp, (struct sockaddr_in6 *)nam, l);
                if (!error) {
                        /* mapped addr case */
                        if (IN6_IS_ADDR_V4MAPPED(&in6p_faddr(inp)))
                                tp->t_family = AF_INET;
                        else
                                tp->t_family = AF_INET6;
                }
        }
#endif
        if (error)
                goto release;
        tp->t_template = tcp_template(tp);
        if (tp->t_template == 0) {
                if (inp->inp_af == AF_INET)
                        inpcb_disconnect(inp);
#ifdef INET6
                else if (inp->inp_af == AF_INET6)
                        in6pcb_disconnect(inp);
#endif
                error = ENOBUFS;
                goto release;
        }
        /*
         * Compute window scaling to request.
         * XXX: This should be moved to tcp_output().
         */
        while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
            (TCP_MAXWIN << tp->request_r_scale) < sb_max)
                tp->request_r_scale++;
        soisconnecting(so);
        TCP_STATINC(TCP_STAT_CONNATTEMPT);
        tp->t_state = TCPS_SYN_SENT;
        TCP_TIMER_ARM(tp, TCPT_KEEP, tp->t_keepinit);
        tp->iss = tcp_new_iss(tp);
        tcp_sendseqinit(tp);
        error = tcp_output(tp);

release:
        tcp_debug_trace(so, tp, ostate, PRU_CONNECT);
        splx(s);

        return error;
}

static int
tcp_connect2(struct socket *so, struct socket *so2)
{
        struct inpcb *inp;
        struct tcpcb *tp;
        int ostate = 0;

        KASSERT(solocked(so));

        inp = sotoinpcb(so);
        if (inp == NULL)
                return EINVAL;
        tp = intotcpcb(inp);

        ostate = tcp_debug_capture(tp, PRU_CONNECT2);

        tcp_debug_trace(so, tp, ostate, PRU_CONNECT2);

        return EOPNOTSUPP;
}

static int
tcp_disconnect(struct socket *so)
{
        struct inpcb *inp;
        struct tcpcb *tp;
        int error = 0;
        int ostate = 0;
        int s;

        inp = sotoinpcb(so);
        if (inp == NULL)
                return EINVAL;
        tp = intotcpcb(inp);

        ostate = tcp_debug_capture(tp, PRU_DISCONNECT);

        /*
         * 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.
         */
        s = splsoftnet();
        tp = tcp_disconnect1(tp);
        tcp_debug_trace(so, tp, ostate, PRU_DISCONNECT);
        splx(s);

        return error;
}

static int
tcp_shutdown(struct socket *so)
{
        struct inpcb *inp;
        struct tcpcb *tp;
        int error = 0;
        int ostate = 0;
        int s;

        inp = sotoinpcb(so);
        if (inp == NULL)
                return EINVAL;
        tp = intotcpcb(inp);

        ostate = tcp_debug_capture(tp, PRU_SHUTDOWN);
        /*
         * Mark the connection as being incapable of further output.
         */
        s = splsoftnet();
        socantsendmore(so);
        tp = tcp_usrclosed(tp);
        if (tp)
                error = tcp_output(tp);
        tcp_debug_trace(so, tp, ostate, PRU_SHUTDOWN);
        splx(s);

        return error;
}

static int
tcp_abort(struct socket *so)
{
        struct inpcb *inp;
        struct tcpcb *tp;
        int error = 0;
        int ostate = 0;
        int s;

        inp = sotoinpcb(so);
        if (inp == NULL)
                return EINVAL;
        tp = intotcpcb(inp);

        ostate = tcp_debug_capture(tp, PRU_ABORT);

        /*
         * Abort the TCP.
         */
        s = splsoftnet();
        tp = tcp_drop(tp, ECONNABORTED);
        tcp_debug_trace(so, tp, ostate, PRU_ABORT);
        splx(s);

        return error;
}

static int
tcp_ioctl(struct socket *so, u_long cmd, void *nam, struct ifnet *ifp)
{
        switch (so->so_proto->pr_domain->dom_family) {
        case PF_INET:
                return in_control(so, cmd, nam, ifp);
#ifdef INET6
        case PF_INET6:
                return in6_control(so, cmd, nam, ifp);
#endif
        default:
                return EAFNOSUPPORT;
        }
}

static int
tcp_stat(struct socket *so, struct stat *ub)
{
        KASSERT(solocked(so));

        /* stat: don't bother with a blocksize.  */
        return 0;
}

static int
tcp_peeraddr(struct socket *so, struct sockaddr *nam)
{
        struct inpcb *inp;
        struct tcpcb *tp;
        int ostate = 0;
        int s;

        inp = sotoinpcb(so);
        if (inp == NULL)
                return EINVAL;
        tp = intotcpcb(inp);

        ostate = tcp_debug_capture(tp, PRU_PEERADDR);

        s = splsoftnet();
        if (inp->inp_af == AF_INET) {
                inpcb_fetch_peeraddr(inp, (struct sockaddr_in *)nam);
        }
#ifdef INET6
        else if (inp->inp_af == AF_INET6) {
                in6pcb_fetch_peeraddr(inp, (struct sockaddr_in6 *)nam);
        }
#endif
        tcp_debug_trace(so, tp, ostate, PRU_PEERADDR);
        splx(s);

        return 0;
}

static int
tcp_sockaddr(struct socket *so, struct sockaddr *nam)
{
        struct inpcb *inp;
        struct tcpcb *tp;
        int ostate = 0;
        int s;

        inp = sotoinpcb(so);
        if (inp == NULL)
                return EINVAL;
        tp = intotcpcb(inp);

        ostate = tcp_debug_capture(tp, PRU_SOCKADDR);

        s = splsoftnet();
        if (inp->inp_af == AF_INET) {
                inpcb_fetch_sockaddr(inp, (struct sockaddr_in *)nam);
        }
#ifdef INET6
        if (inp->inp_af == AF_INET6) {
                in6pcb_fetch_sockaddr(inp, (struct sockaddr_in6 *)nam);
        }
#endif
        tcp_debug_trace(so, tp, ostate, PRU_SOCKADDR);
        splx(s);

        return 0;
}

static int
tcp_rcvd(struct socket *so, int flags, struct lwp *l)
{
        struct inpcb *inp;
        struct tcpcb *tp;
        int ostate = 0;
        int s;

        inp = sotoinpcb(so);
        if (inp == NULL)
                return EINVAL;
        tp = intotcpcb(inp);

        ostate = tcp_debug_capture(tp, PRU_RCVD);

        /*
         * After a receive, possibly send window update to peer.
         *
         * soreceive() calls this function when a user receives
         * ancillary data on a listening socket. We don't call
         * tcp_output in such a case, since there is no header
         * template for a listening socket and hence the kernel
         * will panic.
         */
        s = splsoftnet();
        if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) != 0)
                (void) tcp_output(tp);
        splx(s);

        tcp_debug_trace(so, tp, ostate, PRU_RCVD);

        return 0;
}

static int
tcp_recvoob(struct socket *so, struct mbuf *m, int flags)
{
        struct inpcb *inp;
        struct tcpcb *tp;
        int ostate = 0;
        int s;

        inp = sotoinpcb(so);
        if (inp == NULL)
                return EINVAL;
        tp = intotcpcb(inp);

        ostate = tcp_debug_capture(tp, PRU_RCVOOB);

        s = splsoftnet();
        if ((so->so_oobmark == 0 &&
            (so->so_state & SS_RCVATMARK) == 0) ||
            so->so_options & SO_OOBINLINE ||
            tp->t_oobflags & TCPOOB_HADDATA) {
                splx(s);
                return EINVAL;
        }

        if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
                splx(s);
                return EWOULDBLOCK;
        }

        m->m_len = 1;
        *mtod(m, char *) = tp->t_iobc;
        if ((flags & MSG_PEEK) == 0) {
                tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
                so->so_state &= ~SS_POLLRDBAND;
        }

        tcp_debug_trace(so, tp, ostate, PRU_RCVOOB);
        splx(s);

        return 0;
}

static int
tcp_send(struct socket *so, struct mbuf *m, struct sockaddr *nam,
    struct mbuf *control, struct lwp *l)
{
        struct inpcb *inp;
        struct tcpcb *tp;
        int ostate = 0;
        int error = 0;
        int s;

        inp = sotoinpcb(so);
        if (inp == NULL)
                return EINVAL;
        tp = intotcpcb(inp);

        ostate = tcp_debug_capture(tp, PRU_SEND);

        /*
         * Do a send by putting data in output queue and updating urgent
         * marker if URG set.  Possibly send more data.
         */
        s = splsoftnet();
        if (control && control->m_len) {
                m_freem(control);
                m_freem(m);
                tcp_debug_trace(so, tp, ostate, PRU_SEND);
                splx(s);
                return EINVAL;
        }

        sbappendstream(&so->so_snd, m);
        error = tcp_output(tp);
        tcp_debug_trace(so, tp, ostate, PRU_SEND);
        splx(s);

        return error;
}

static int
tcp_sendoob(struct socket *so, struct mbuf *m, struct mbuf *control)
{
        struct inpcb *inp = NULL;
        struct tcpcb *tp = NULL;
        int ostate = 0;
        int error = 0;
        int s;

        inp = sotoinpcb(so);
        if (inp == NULL) {
                m_freem(m);
                m_freem(control);
                return EINVAL;
        }
        tp = intotcpcb(inp);
        if (tp->t_template == NULL) {
                /*
                 * XXX FreeBSD appears to open the connection
                 * automagically in this case, but the socket address
                 * isn't passed through here so we can't do that.
                 */
                m_freem(m);
                m_freem(control);
                return ENOTCONN;
        }

        ostate = tcp_debug_capture(tp, PRU_SENDOOB);

        s = splsoftnet();
        if (sbspace_oob(&so->so_snd) == 0) {
                m_freem(m);
                m_freem(control);
                splx(s);
                return ENOBUFS;
        }
        /*
         * 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.
         */
        sbappendstream(&so->so_snd, m);
        tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
        tp->t_force = 1;
        error = tcp_output(tp);
        tp->t_force = 0;
        tcp_debug_trace(so, tp, ostate, PRU_SENDOOB);
        splx(s);
        m_freem(control);

        return error;
}

static int
tcp_purgeif(struct socket *so, struct ifnet *ifp)
{
        int s;
        int error = 0;

        s = splsoftnet();

        mutex_enter(softnet_lock);
        switch (so->so_proto->pr_domain->dom_family) {
        case PF_INET:
                inpcb_purgeif0(&tcbtable, ifp);
#ifdef NET_MPSAFE
                mutex_exit(softnet_lock);
#endif
                in_purgeif(ifp);
#ifdef NET_MPSAFE
                mutex_enter(softnet_lock);
#endif
                inpcb_purgeif(&tcbtable, ifp);
                break;
#ifdef INET6
        case PF_INET6:
                in6pcb_purgeif0(&tcbtable, ifp);
#ifdef NET_MPSAFE
                mutex_exit(softnet_lock);
#endif
                in6_purgeif(ifp);
#ifdef NET_MPSAFE
                mutex_enter(softnet_lock);
#endif
                in6pcb_purgeif(&tcbtable, ifp);
                break;
#endif
        default:
                error = EAFNOSUPPORT;
                break;
        }
        mutex_exit(softnet_lock);
        splx(s);

        return error;
}

/*
 * 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).
 */
struct tcpcb *
tcp_disconnect1(struct tcpcb *tp)
{
        struct socket *so;

        so = tp->t_inpcb->inp_socket;

        if (TCPS_HAVEESTABLISHED(tp->t_state) == 0)
                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.
 */
struct tcpcb *
tcp_usrclosed(struct tcpcb *tp)
{

        switch (tp->t_state) {

        case TCPS_CLOSED:
        case TCPS_LISTEN:
        case TCPS_SYN_SENT:
                tp->t_state = TCPS_CLOSED;
                tp = tcp_close(tp);
                break;

        case TCPS_SYN_RECEIVED:
        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) {
                struct socket *so = tp->t_inpcb->inp_socket;
                if (so)
                        soisdisconnected(so);
                /*
                 * If we are in FIN_WAIT_2, we arrived here because the
                 * application did a shutdown of the send side.  Like the
                 * case of a transition from FIN_WAIT_1 to FIN_WAIT_2 after
                 * a full close, we start a timer to make sure sockets are
                 * not left in FIN_WAIT_2 forever.
                 */
                if ((tp->t_state == TCPS_FIN_WAIT_2) && (tp->t_maxidle > 0))
                        TCP_TIMER_ARM(tp, TCPT_2MSL, tp->t_maxidle);
                else if (tp->t_state == TCPS_TIME_WAIT
                         && ((tp->t_inpcb->inp_af == AF_INET
                              && (tcp4_vtw_enable & 1)
                              && vtw_add(AF_INET, tp))
                             ||
                             (tp->t_inpcb->inp_af == AF_INET6
                              && (tcp6_vtw_enable & 1)
                              && vtw_add(AF_INET6, tp)))) {
                        tp = 0;
                }
        }
        return tp;
}

/*
 * sysctl helper routine for net.inet.ip.mssdflt.  it can't be less
 * than 32.
 */
static int
sysctl_net_inet_tcp_mssdflt(SYSCTLFN_ARGS)
{
        int error, mssdflt;
        struct sysctlnode node;

        mssdflt = tcp_mssdflt;
        node = *rnode;
        node.sysctl_data = &mssdflt;
        error = sysctl_lookup(SYSCTLFN_CALL(&node));
        if (error || newp == NULL)
                return error;

        if (mssdflt < 32)
                return EINVAL;
        tcp_mssdflt = mssdflt;

        mutex_enter(softnet_lock);
        tcp_tcpcb_template();
        mutex_exit(softnet_lock);

        return 0;
}

/*
 * sysctl helper for TCP CB template update
 */
static int
sysctl_update_tcpcb_template(SYSCTLFN_ARGS)
{
        int t, error;
        struct sysctlnode node;

        /* follow procedures in sysctl(9) manpage */
        t = *(int *)rnode->sysctl_data;
        node = *rnode;
        node.sysctl_data = &t;
        error = sysctl_lookup(SYSCTLFN_CALL(&node));
        if (error || newp == NULL)
                return error;

        if (t < 0)
                return EINVAL;

        *(int *)rnode->sysctl_data = t;

        mutex_enter(softnet_lock);
        tcp_tcpcb_template();
        mutex_exit(softnet_lock);

        return 0;
}

/*
 * sysctl helper routine for setting port related values under
 * net.inet.ip and net.inet6.ip6.  does basic range checking and does
 * additional checks for each type.  this code has placed in
 * tcp_input.c since INET and INET6 both use the same tcp code.
 *
 * this helper is not static so that both inet and inet6 can use it.
 */
int
sysctl_net_inet_ip_ports(SYSCTLFN_ARGS)
{
        int error, tmp;
        int apmin, apmax;
#ifndef IPNOPRIVPORTS
        int lpmin, lpmax;
#endif /* IPNOPRIVPORTS */
        struct sysctlnode node;

        if (namelen != 0)
                return EINVAL;

        switch (name[-3]) {
            case PF_INET:
                apmin = anonportmin;
                apmax = anonportmax;
#ifndef IPNOPRIVPORTS
                lpmin = lowportmin;
                lpmax = lowportmax;
#endif /* IPNOPRIVPORTS */
                break;
#ifdef INET6
            case PF_INET6:
                apmin = ip6_anonportmin;
                apmax = ip6_anonportmax;
#ifndef IPNOPRIVPORTS
                lpmin = ip6_lowportmin;
                lpmax = ip6_lowportmax;
#endif /* IPNOPRIVPORTS */
                break;
#endif /* INET6 */
            default:
                return EINVAL;
        }

        /*
         * insert temporary copy into node, perform lookup on
         * temporary, then restore pointer
         */
        node = *rnode;
        tmp = *(int*)rnode->sysctl_data;
        node.sysctl_data = &tmp;
        error = sysctl_lookup(SYSCTLFN_CALL(&node));
        if (error || newp == NULL)
                return error;

        /*
         * simple port range check
         */
        if (tmp < 0 || tmp > 65535)
                return EINVAL;

        /*
         * per-node range checks
         */
        switch (rnode->sysctl_num) {
        case IPCTL_ANONPORTMIN:
        case IPV6CTL_ANONPORTMIN:
                if (tmp >= apmax)
                        return EINVAL;
#ifndef IPNOPRIVPORTS
                if (tmp < IPPORT_RESERVED)
                        return EINVAL;
#endif /* IPNOPRIVPORTS */
                break;

        case IPCTL_ANONPORTMAX:
        case IPV6CTL_ANONPORTMAX:
                if (apmin >= tmp)
                        return EINVAL;
#ifndef IPNOPRIVPORTS
                if (tmp < IPPORT_RESERVED)
                        return EINVAL;
#endif /* IPNOPRIVPORTS */
                break;

#ifndef IPNOPRIVPORTS
        case IPCTL_LOWPORTMIN:
        case IPV6CTL_LOWPORTMIN:
                if (tmp >= lpmax ||
                    tmp > IPPORT_RESERVEDMAX ||
                    tmp < IPPORT_RESERVEDMIN)
                        return EINVAL;
                break;

        case IPCTL_LOWPORTMAX:
        case IPV6CTL_LOWPORTMAX:
                if (lpmin >= tmp ||
                    tmp > IPPORT_RESERVEDMAX ||
                    tmp < IPPORT_RESERVEDMIN)
                        return EINVAL;
                break;
#endif /* IPNOPRIVPORTS */

        default:
                return EINVAL;
        }

        *(int*)rnode->sysctl_data = tmp;

        return 0;
}

static inline int
copyout_uid(struct socket *sockp, void *oldp, size_t *oldlenp)
{
        if (oldp) {
                size_t sz;
                uid_t uid;
                int error;

                if (sockp->so_cred == NULL)
                        return EPERM;

                uid = kauth_cred_geteuid(sockp->so_cred);
                sz = MIN(sizeof(uid), *oldlenp);
                if ((error = copyout(&uid, oldp, sz)) != 0)
                        return error;
        }
        *oldlenp = sizeof(uid_t);
        return 0;
}

static inline int
inet4_ident_core(struct in_addr raddr, u_int rport,
    struct in_addr laddr, u_int lport,
    void *oldp, size_t *oldlenp,
    struct lwp *l, int dodrop)
{
        struct inpcb *inp;
        struct socket *sockp;

        inp = inpcb_lookup(&tcbtable, raddr, rport, laddr, lport, 0);

        if (inp == NULL || (sockp = inp->inp_socket) == NULL)
                return ESRCH;

        if (dodrop) {
                struct tcpcb *tp;
                int error;

                if (inp == NULL || (tp = intotcpcb(inp)) == NULL ||
                    (inp->inp_socket->so_options & SO_ACCEPTCONN) != 0)
                        return ESRCH;

                error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_SOCKET,
                    KAUTH_REQ_NETWORK_SOCKET_DROP, inp->inp_socket, tp, NULL);
                if (error)
                        return error;

                (void)tcp_drop(tp, ECONNABORTED);
                return 0;
        }

        return copyout_uid(sockp, oldp, oldlenp);
}

#ifdef INET6
static inline int
inet6_ident_core(struct in6_addr *raddr, u_int rport,
    struct in6_addr *laddr, u_int lport,
    void *oldp, size_t *oldlenp,
    struct lwp *l, int dodrop)
{
        struct inpcb *inp;
        struct socket *sockp;

        inp = in6pcb_lookup(&tcbtable, raddr, rport, laddr, lport, 0, 0);

        if (inp == NULL || (sockp = inp->inp_socket) == NULL)
                return ESRCH;

        if (dodrop) {
                struct tcpcb *tp;
                int error;

                if (inp == NULL || (tp = intotcpcb(inp)) == NULL ||
                    (inp->inp_socket->so_options & SO_ACCEPTCONN) != 0)
                        return ESRCH;

                error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_SOCKET,
                    KAUTH_REQ_NETWORK_SOCKET_DROP, inp->inp_socket, tp, NULL);
                if (error)
                        return error;

                (void)tcp_drop(tp, ECONNABORTED);
                return 0;
        }

        return copyout_uid(sockp, oldp, oldlenp);
}
#endif

/*
 * sysctl helper routine for the net.inet.tcp.drop and
 * net.inet6.tcp6.drop nodes.
 */
#define sysctl_net_inet_tcp_drop sysctl_net_inet_tcp_ident

/*
 * sysctl helper routine for the net.inet.tcp.ident and
 * net.inet6.tcp6.ident nodes.  contains backwards compat code for the
 * old way of looking up the ident information for ipv4 which involves
 * stuffing the port/addr pairs into the mib lookup.
 */
static int
sysctl_net_inet_tcp_ident(SYSCTLFN_ARGS)
{
        struct sockaddr_in *si4[2];
#ifdef INET6
        struct sockaddr_in6 *si6[2];
#endif
        struct sockaddr_storage sa[2];
        int error, pf, dodrop;

        dodrop = name[-1] == TCPCTL_DROP;
        if (dodrop) {
                if (oldp != NULL || *oldlenp != 0)
                        return EINVAL;
                if (newp == NULL)
                        return EPERM;
                if (newlen < sizeof(sa))
                        return ENOMEM;
        }
        if (namelen != 4 && namelen != 0)
                return EINVAL;
        if (name[-2] != IPPROTO_TCP)
                return EINVAL;
        pf = name[-3];

        /* old style lookup, ipv4 only */
        if (namelen == 4) {
                struct in_addr laddr, raddr;
                u_int lport, rport;

                if (pf != PF_INET)
                        return EPROTONOSUPPORT;
                raddr.s_addr = (uint32_t)name[0];
                rport = (u_int)name[1];
                laddr.s_addr = (uint32_t)name[2];
                lport = (u_int)name[3];

                mutex_enter(softnet_lock);
                error = inet4_ident_core(raddr, rport, laddr, lport,
                    oldp, oldlenp, l, dodrop);
                mutex_exit(softnet_lock);
                return error;
        }

        if (newp == NULL || newlen != sizeof(sa))
                return EINVAL;
        error = copyin(newp, &sa, newlen);
        if (error)
                return error;

        /*
         * requested families must match
         */
        if (pf != sa[0].ss_family || sa[0].ss_family != sa[1].ss_family)
                return EINVAL;

        switch (pf) {
#ifdef INET6
        case PF_INET6:
                si6[0] = (struct sockaddr_in6*)&sa[0];
                si6[1] = (struct sockaddr_in6*)&sa[1];
                if (si6[0]->sin6_len != sizeof(*si6[0]) ||
                    si6[1]->sin6_len != sizeof(*si6[1]))
                        return EINVAL;

                if (!IN6_IS_ADDR_V4MAPPED(&si6[0]->sin6_addr) &&
                    !IN6_IS_ADDR_V4MAPPED(&si6[1]->sin6_addr)) {
                        error = sa6_embedscope(si6[0], ip6_use_defzone);
                        if (error)
                                return error;
                        error = sa6_embedscope(si6[1], ip6_use_defzone);
                        if (error)
                                return error;

                        mutex_enter(softnet_lock);
                        error = inet6_ident_core(&si6[0]->sin6_addr,
                            si6[0]->sin6_port, &si6[1]->sin6_addr,
                            si6[1]->sin6_port, oldp, oldlenp, l, dodrop);
                        mutex_exit(softnet_lock);
                        return error;
                }

                if (IN6_IS_ADDR_V4MAPPED(&si6[0]->sin6_addr) !=
                    IN6_IS_ADDR_V4MAPPED(&si6[1]->sin6_addr))
                        return EINVAL;

                in6_sin6_2_sin_in_sock((struct sockaddr *)&sa[0]);
                in6_sin6_2_sin_in_sock((struct sockaddr *)&sa[1]);
#endif /* INET6 */
                /*FALLTHROUGH*/
        case PF_INET:
                si4[0] = (struct sockaddr_in*)&sa[0];
                si4[1] = (struct sockaddr_in*)&sa[1];
                if (si4[0]->sin_len != sizeof(*si4[0]) ||
                    si4[0]->sin_len != sizeof(*si4[1]))
                        return EINVAL;

                mutex_enter(softnet_lock);
                error = inet4_ident_core(si4[0]->sin_addr, si4[0]->sin_port,
                    si4[1]->sin_addr, si4[1]->sin_port,
                    oldp, oldlenp, l, dodrop);
                mutex_exit(softnet_lock);
                return error;
        default:
                return EPROTONOSUPPORT;
        }
}

/*
 * sysctl helper for the inet and inet6 pcblists.  handles tcp/udp and
 * inet/inet6, as well as raw pcbs for each.  specifically not
 * declared static so that raw sockets and udp/udp6 can use it as
 * well.
 */
int
sysctl_inpcblist(SYSCTLFN_ARGS)
{
        const bool allowaddr = get_expose_address(curproc);
        struct sockaddr_in *in;
        const struct inpcb *inp;
#ifdef INET6
        struct sockaddr_in6 *in6;
#endif
        struct inpcbtable *pcbtbl = __UNCONST(rnode->sysctl_data);
        struct tcpcb *tp;
        struct kinfo_pcb pcb;
        char *dp;
        size_t len, needed, elem_size, out_size;
        int error, elem_count, pf, proto, pf2;

        if (namelen != 4)
                return EINVAL;

        if (oldp != NULL) {
                    len = *oldlenp;
                    elem_size = name[2];
                    elem_count = name[3];
                    if (elem_size != sizeof(pcb))
                            return EINVAL;
        } else {
                    len = 0;
                    elem_count = INT_MAX;
                    elem_size = sizeof(pcb);
        }
        error = 0;
        dp = oldp;
        out_size = elem_size;
        needed = 0;

        if (namelen == 1 && name[0] == CTL_QUERY)
                return (sysctl_query(SYSCTLFN_CALL(rnode)));

        if (name - oname != 4)
                return EINVAL;

        pf = oname[1];
        proto = oname[2];
        pf2 = (oldp != NULL) ? pf : 0;

        mutex_enter(softnet_lock);

        TAILQ_FOREACH(inp, &pcbtbl->inpt_queue, inp_queue) {
                if (inp->inp_af != pf)
                        continue;

                if (kauth_authorize_network(l->l_cred, KAUTH_NETWORK_SOCKET,
                    KAUTH_REQ_NETWORK_SOCKET_CANSEE, inp->inp_socket, NULL,
                    NULL) != 0)
                        continue;

                memset(&pcb, 0, sizeof(pcb));

                pcb.ki_family = pf;
                pcb.ki_type = proto;

                switch (pf2) {
                case 0:
                        /* just probing for size */
                        break;
                case PF_INET:
                        pcb.ki_family = inp->inp_socket->so_proto->
                            pr_domain->dom_family;
                        pcb.ki_type = inp->inp_socket->so_proto->
                            pr_type;
                        pcb.ki_protocol = inp->inp_socket->so_proto->
                            pr_protocol;
                        pcb.ki_pflags = inp->inp_flags;

                        pcb.ki_sostate = inp->inp_socket->so_state;
                        pcb.ki_prstate = inp->inp_state;
                        if (proto == IPPROTO_TCP) {
                                tp = intotcpcb(inp);
                                pcb.ki_tstate = tp->t_state;
                                pcb.ki_tflags = tp->t_flags;
                        }

                        COND_SET_VALUE(pcb.ki_pcbaddr,
                            PTRTOUINT64(inp), allowaddr);
                        COND_SET_VALUE(pcb.ki_ppcbaddr,
                            PTRTOUINT64(inp->inp_ppcb), allowaddr);
                        COND_SET_VALUE(pcb.ki_sockaddr,
                            PTRTOUINT64(inp->inp_socket), allowaddr);

                        pcb.ki_rcvq = inp->inp_socket->so_rcv.sb_cc;
                        pcb.ki_sndq = inp->inp_socket->so_snd.sb_cc;

                        in = satosin(&pcb.ki_src);
                        in->sin_len = sizeof(*in);
                        in->sin_family = pf;
                        in->sin_port = inp->inp_lport;
                        in->sin_addr = const_in4p_laddr(inp);
                        if (pcb.ki_prstate >= INP_CONNECTED) {
                                in = satosin(&pcb.ki_dst);
                                in->sin_len = sizeof(*in);
                                in->sin_family = pf;
                                in->sin_port = inp->inp_fport;
                                in->sin_addr = const_in4p_faddr(inp);
                        }
                        break;
#ifdef INET6
                case PF_INET6:
                        pcb.ki_family = inp->inp_socket->so_proto->
                            pr_domain->dom_family;
                        pcb.ki_type = inp->inp_socket->so_proto->pr_type;
                        pcb.ki_protocol = inp->inp_socket->so_proto->
                            pr_protocol;
                        pcb.ki_pflags = inp->inp_flags;

                        pcb.ki_sostate = inp->inp_socket->so_state;
                        pcb.ki_prstate = inp->inp_state;
                        if (proto == IPPROTO_TCP) {
                                tp = intotcpcb(inp);
                                pcb.ki_tstate = tp->t_state;
                                pcb.ki_tflags = tp->t_flags;
                        }

                        COND_SET_VALUE(pcb.ki_pcbaddr,
                            PTRTOUINT64(inp), allowaddr);
                        COND_SET_VALUE(pcb.ki_ppcbaddr,
                            PTRTOUINT64(inp->inp_ppcb), allowaddr);
                        COND_SET_VALUE(pcb.ki_sockaddr,
                            PTRTOUINT64(inp->inp_socket), allowaddr);

                        pcb.ki_rcvq = inp->inp_socket->so_rcv.sb_cc;
                        pcb.ki_sndq = inp->inp_socket->so_snd.sb_cc;

                        in6 = satosin6(&pcb.ki_src);
                        in6->sin6_len = sizeof(*in6);
                        in6->sin6_family = pf;
                        in6->sin6_port = inp->inp_lport;
                        in6->sin6_flowinfo = const_in6p_flowinfo(inp);
                        in6->sin6_addr = const_in6p_laddr(inp);
                        in6->sin6_scope_id = 0; /* XXX? */

                        if (pcb.ki_prstate >= INP_CONNECTED) {
                                in6 = satosin6(&pcb.ki_dst);
                                in6->sin6_len = sizeof(*in6);
                                in6->sin6_family = pf;
                                in6->sin6_port = inp->inp_fport;
                                in6->sin6_flowinfo = const_in6p_flowinfo(inp);
                                in6->sin6_addr = const_in6p_faddr(inp);
                                in6->sin6_scope_id = 0; /* XXX? */
                        }
                        break;
#endif
                }

                if (len >= elem_size && elem_count > 0) {
                        error = copyout(&pcb, dp, out_size);
                        if (error) {
                                mutex_exit(softnet_lock);
                                return error;
                        }
                        dp += elem_size;
                        len -= elem_size;
                }
                needed += elem_size;
                if (elem_count > 0 && elem_count != INT_MAX)
                        elem_count--;
        }

        *oldlenp = needed;
        if (oldp == NULL)
                *oldlenp += PCB_SLOP * sizeof(struct kinfo_pcb);

        mutex_exit(softnet_lock);

        return error;
}

static int
sysctl_tcp_congctl(SYSCTLFN_ARGS)
{
        struct sysctlnode node;
        int error;
        char newname[TCPCC_MAXLEN];

        strlcpy(newname, tcp_congctl_global_name, sizeof(newname) - 1);

        node = *rnode;
        node.sysctl_data = newname;
        node.sysctl_size = sizeof(newname);

        error = sysctl_lookup(SYSCTLFN_CALL(&node));

        if (error ||
            newp == NULL ||
            strncmp(newname, tcp_congctl_global_name, sizeof(newname)) == 0)
                return error;

        mutex_enter(softnet_lock);
        error = tcp_congctl_select(NULL, newname);
        mutex_exit(softnet_lock);

        return error;
}

static int
sysctl_tcp_init_win(SYSCTLFN_ARGS)
{
        int error;
        u_int iw;
        struct sysctlnode node;

        iw = *(u_int *)rnode->sysctl_data;
        node = *rnode;
        node.sysctl_data = &iw;
        node.sysctl_size = sizeof(iw);
        error = sysctl_lookup(SYSCTLFN_CALL(&node));
        if (error || newp == NULL)
                return error;

        if (iw >= __arraycount(tcp_init_win_max))
                return EINVAL;
        *(u_int *)rnode->sysctl_data = iw;
        return 0;
}

static int
sysctl_tcp_keep(SYSCTLFN_ARGS)
{
        int error;
        u_int tmp;
        struct sysctlnode node;

        node = *rnode;
        tmp = *(u_int *)rnode->sysctl_data;
        node.sysctl_data = &tmp;

        error = sysctl_lookup(SYSCTLFN_CALL(&node));
        if (error || newp == NULL)
                return error;

        if (!(tmp > 0 && tmp <= TCP_TIMER_MAXTICKS))
                return EINVAL;

        mutex_enter(softnet_lock);

        *(u_int *)rnode->sysctl_data = tmp;
        tcp_tcpcb_template();   /* update the template */

        mutex_exit(softnet_lock);
        return 0;
}

static int
sysctl_net_inet_tcp_stats(SYSCTLFN_ARGS)
{

        return (NETSTAT_SYSCTL(tcpstat_percpu, TCP_NSTATS));
}

/*
 * this (second stage) setup routine is a replacement for tcp_sysctl()
 * (which is currently used for ipv4 and ipv6)
 */
static void
sysctl_net_inet_tcp_setup2(struct sysctllog **clog, int pf, const char *pfname,
                           const char *tcpname)
{
        const struct sysctlnode *sack_node;
        const struct sysctlnode *abc_node;
        const struct sysctlnode *ecn_node;
        const struct sysctlnode *congctl_node;
        const struct sysctlnode *mslt_node;
        const struct sysctlnode *vtw_node;
#ifdef TCP_DEBUG
        extern struct tcp_debug tcp_debug[TCP_NDEBUG];
        extern int tcp_debx;
#endif

        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, pfname, NULL,
                       NULL, 0, NULL, 0,
                       CTL_NET, pf, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, tcpname,
                       SYSCTL_DESCR("TCP related settings"),
                       NULL, 0, NULL, 0,
                       CTL_NET, pf, IPPROTO_TCP, CTL_EOL);

        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "rfc1323",
                       SYSCTL_DESCR("Enable RFC1323 TCP extensions"),
                       sysctl_update_tcpcb_template, 0, &tcp_do_rfc1323, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_RFC1323, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "sendspace",
                       SYSCTL_DESCR("Default TCP send buffer size"),
                       NULL, 0, &tcp_sendspace, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_SENDSPACE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "recvspace",
                       SYSCTL_DESCR("Default TCP receive buffer size"),
                       NULL, 0, &tcp_recvspace, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_RECVSPACE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "mssdflt",
                       SYSCTL_DESCR("Default maximum segment size"),
                       sysctl_net_inet_tcp_mssdflt, 0, &tcp_mssdflt, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_MSSDFLT, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "minmss",
                       SYSCTL_DESCR("Lower limit for TCP maximum segment size"),
                       NULL, 0, &tcp_minmss, 0,
                       CTL_NET, pf, IPPROTO_TCP, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "msl",
                       SYSCTL_DESCR("Maximum Segment Life"),
                       NULL, 0, &tcp_msl, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_MSL, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "syn_cache_limit",
                       SYSCTL_DESCR("Maximum number of entries in the TCP "
                                    "compressed state engine"),
                       NULL, 0, &tcp_syn_cache_limit, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_SYN_CACHE_LIMIT,
                       CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "syn_bucket_limit",
                       SYSCTL_DESCR("Maximum number of entries per hash "
                                    "bucket in the TCP compressed state "
                                    "engine"),
                       NULL, 0, &tcp_syn_bucket_limit, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_SYN_BUCKET_LIMIT,
                       CTL_EOL);
#if 0 /* obsoleted */
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "syn_cache_interval",
                       SYSCTL_DESCR("TCP compressed state engine's timer interval"),
                       NULL, 0, &tcp_syn_cache_interval, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_SYN_CACHE_INTER,
                       CTL_EOL);
#endif
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "init_win",
                       SYSCTL_DESCR("Initial TCP congestion window"),
                       sysctl_tcp_init_win, 0, &tcp_init_win, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_INIT_WIN, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "mss_ifmtu",
                       SYSCTL_DESCR("Use interface MTU for calculating MSS"),
                       NULL, 0, &tcp_mss_ifmtu, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_MSS_IFMTU, CTL_EOL);
        sysctl_createv(clog, 0, NULL, &sack_node,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "sack",
                       SYSCTL_DESCR("RFC2018 Selective ACKnowledgement tunables"),
                       NULL, 0, NULL, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_SACK, CTL_EOL);

        /* Congctl subtree */
        sysctl_createv(clog, 0, NULL, &congctl_node,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "congctl",
                       SYSCTL_DESCR("TCP Congestion Control"),
                       NULL, 0, NULL, 0,
                       CTL_NET, pf, IPPROTO_TCP, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, &congctl_node, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_STRING, "available",
                       SYSCTL_DESCR("Available Congestion Control Mechanisms"),
                       NULL, 0, tcp_congctl_avail, 0, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, &congctl_node, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_STRING, "selected",
                       SYSCTL_DESCR("Selected Congestion Control Mechanism"),
                       sysctl_tcp_congctl, 0, NULL, TCPCC_MAXLEN,
                       CTL_CREATE, CTL_EOL);

        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "win_scale",
                       SYSCTL_DESCR("Use RFC1323 window scale options"),
                       sysctl_update_tcpcb_template, 0, &tcp_do_win_scale, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_WSCALE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "timestamps",
                       SYSCTL_DESCR("Use RFC1323 time stamp options"),
                       sysctl_update_tcpcb_template, 0, &tcp_do_timestamps, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_TSTAMP, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "cwm",
                       SYSCTL_DESCR("Hughes/Touch/Heidemann Congestion Window "
                                    "Monitoring"),
                       NULL, 0, &tcp_cwm, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_CWM, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "cwm_burstsize",
                       SYSCTL_DESCR("Congestion Window Monitoring allowed "
                                    "burst count in packets"),
                       NULL, 0, &tcp_cwm_burstsize, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_CWM_BURSTSIZE,
                       CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "ack_on_push",
                       SYSCTL_DESCR("Immediately return ACK when PSH is "
                                    "received"),
                       NULL, 0, &tcp_ack_on_push, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_ACK_ON_PUSH, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "keepidle",
                       SYSCTL_DESCR("Allowed connection idle ticks before a "
                                    "keepalive probe is sent"),
                       sysctl_tcp_keep, 0, &tcp_keepidle, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_KEEPIDLE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "keepintvl",
                       SYSCTL_DESCR("Ticks before next keepalive probe is sent"),
                       sysctl_tcp_keep, 0, &tcp_keepintvl, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_KEEPINTVL, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "keepcnt",
                       SYSCTL_DESCR("Number of keepalive probes to send"),
                       sysctl_tcp_keep, 0, &tcp_keepcnt, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_KEEPCNT, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE,
                       CTLTYPE_INT, "slowhz",
                       SYSCTL_DESCR("Keepalive ticks per second"),
                       NULL, PR_SLOWHZ, NULL, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_SLOWHZ, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "log_refused",
                       SYSCTL_DESCR("Log refused TCP connections"),
                       NULL, 0, &tcp_log_refused, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_LOG_REFUSED, CTL_EOL);
#if 0 /* obsoleted */
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "rstratelimit", NULL,
                       NULL, 0, &tcp_rst_ratelim, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_RSTRATELIMIT, CTL_EOL);
#endif
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "rstppslimit",
                       SYSCTL_DESCR("Maximum number of RST packets to send "
                                    "per second"),
                       NULL, 0, &tcp_rst_ppslim, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_RSTPPSLIMIT, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "delack_ticks",
                       SYSCTL_DESCR("Number of ticks to delay sending an ACK"),
                       NULL, 0, &tcp_delack_ticks, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_DELACK_TICKS, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "init_win_local",
                       SYSCTL_DESCR("Initial TCP window size (in segments)"),
                       sysctl_tcp_init_win, 0, &tcp_init_win_local, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_INIT_WIN_LOCAL,
                       CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_STRUCT, "ident",
                       SYSCTL_DESCR("RFC1413 Identification Protocol lookups"),
                       sysctl_net_inet_tcp_ident, 0, NULL, sizeof(uid_t),
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_IDENT, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "do_loopback_cksum",
                       SYSCTL_DESCR("Perform TCP checksum on loopback"),
                       NULL, 0, &tcp_do_loopback_cksum, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_LOOPBACKCKSUM,
                       CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_STRUCT, "pcblist",
                       SYSCTL_DESCR("TCP protocol control block list"),
                       sysctl_inpcblist, 0, &tcbtable, 0,
                       CTL_NET, pf, IPPROTO_TCP, CTL_CREATE,
                       CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "keepinit",
                       SYSCTL_DESCR("Ticks before initial tcp connection times out"),
                       sysctl_tcp_keep, 0, &tcp_keepinit, 0,
                       CTL_NET, pf, IPPROTO_TCP, CTL_CREATE, CTL_EOL);

        /* TCP socket buffers auto-sizing nodes */
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "recvbuf_auto",
                       SYSCTL_DESCR("Enable automatic receive "
                           "buffer sizing (experimental)"),
                       NULL, 0, &tcp_do_autorcvbuf, 0,
                       CTL_NET, pf, IPPROTO_TCP, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "recvbuf_inc",
                       SYSCTL_DESCR("Incrementor step size of "
                           "automatic receive buffer"),
                       NULL, 0, &tcp_autorcvbuf_inc, 0,
                       CTL_NET, pf, IPPROTO_TCP, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "recvbuf_max",
                       SYSCTL_DESCR("Max size of automatic receive buffer"),
                       NULL, 0, &tcp_autorcvbuf_max, 0,
                       CTL_NET, pf, IPPROTO_TCP, CTL_CREATE, CTL_EOL);

        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "sendbuf_auto",
                       SYSCTL_DESCR("Enable automatic send "
                           "buffer sizing (experimental)"),
                       NULL, 0, &tcp_do_autosndbuf, 0,
                       CTL_NET, pf, IPPROTO_TCP, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "sendbuf_inc",
                       SYSCTL_DESCR("Incrementor step size of "
                           "automatic send buffer"),
                       NULL, 0, &tcp_autosndbuf_inc, 0,
                       CTL_NET, pf, IPPROTO_TCP, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "sendbuf_max",
                       SYSCTL_DESCR("Max size of automatic send buffer"),
                       NULL, 0, &tcp_autosndbuf_max, 0,
                       CTL_NET, pf, IPPROTO_TCP, CTL_CREATE, CTL_EOL);

        /* ECN subtree */
        sysctl_createv(clog, 0, NULL, &ecn_node,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "ecn",
                       SYSCTL_DESCR("RFC3168 Explicit Congestion Notification"),
                       NULL, 0, NULL, 0,
                       CTL_NET, pf, IPPROTO_TCP, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, &ecn_node, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "enable",
                       SYSCTL_DESCR("Enable TCP Explicit Congestion "
                           "Notification"),
                       NULL, 0, &tcp_do_ecn, 0, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, &ecn_node, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "maxretries",
                       SYSCTL_DESCR("Number of times to retry ECN setup "
                               "before disabling ECN on the connection"),
                       NULL, 0, &tcp_ecn_maxretries, 0, CTL_CREATE, CTL_EOL);

        /* SACK gets its own little subtree. */
        sysctl_createv(clog, 0, NULL, &sack_node,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "enable",
                       SYSCTL_DESCR("Enable RFC2018 Selective ACKnowledgement"),
                       NULL, 0, &tcp_do_sack, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_SACK, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, &sack_node,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "maxholes",
                       SYSCTL_DESCR("Maximum number of TCP SACK holes allowed per connection"),
                       NULL, 0, &tcp_sack_tp_maxholes, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_SACK, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, &sack_node,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "globalmaxholes",
                       SYSCTL_DESCR("Global maximum number of TCP SACK holes"),
                       NULL, 0, &tcp_sack_globalmaxholes, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_SACK, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, &sack_node,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_INT, "globalholes",
                       SYSCTL_DESCR("Global number of TCP SACK holes"),
                       NULL, 0, &tcp_sack_globalholes, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_SACK, CTL_CREATE, CTL_EOL);

        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_STRUCT, "stats",
                       SYSCTL_DESCR("TCP statistics"),
                       sysctl_net_inet_tcp_stats, 0, NULL, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_STATS,
                       CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "local_by_rtt",
                       SYSCTL_DESCR("Use RTT estimator to decide which hosts "
                                    "are local"),
                       NULL, 0, &tcp_rttlocal, 0,
                       CTL_NET, pf, IPPROTO_TCP, CTL_CREATE, CTL_EOL);
#ifdef TCP_DEBUG
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_STRUCT, "debug",
                       SYSCTL_DESCR("TCP sockets debug information"),
                       NULL, 0, &tcp_debug, sizeof(tcp_debug),
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_DEBUG,
                       CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_INT, "debx",
                       SYSCTL_DESCR("Number of TCP debug sockets messages"),
                       NULL, 0, &tcp_debx, sizeof(tcp_debx),
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_DEBX,
                       CTL_EOL);
#endif
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_STRUCT, "drop",
                       SYSCTL_DESCR("TCP drop connection"),
                       sysctl_net_inet_tcp_drop, 0, NULL, 0,
                       CTL_NET, pf, IPPROTO_TCP, TCPCTL_DROP, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "iss_hash",
                       SYSCTL_DESCR("Enable RFC 1948 ISS by cryptographic "
                                    "hash computation"),
                       NULL, 0, &tcp_do_rfc1948, sizeof(tcp_do_rfc1948),
                       CTL_NET, pf, IPPROTO_TCP, CTL_CREATE,
                       CTL_EOL);

        /* ABC subtree */

        sysctl_createv(clog, 0, NULL, &abc_node,
                       CTLFLAG_PERMANENT, CTLTYPE_NODE, "abc",
                       SYSCTL_DESCR("RFC3465 Appropriate Byte Counting (ABC)"),
                       NULL, 0, NULL, 0,
                       CTL_NET, pf, IPPROTO_TCP, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, &abc_node, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "enable",
                       SYSCTL_DESCR("Enable RFC3465 Appropriate Byte Counting"),
                       NULL, 0, &tcp_do_abc, 0, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, &abc_node, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "aggressive",
                       SYSCTL_DESCR("1: L=2*SMSS 0: L=1*SMSS"),
                       NULL, 0, &tcp_abc_aggressive, 0, CTL_CREATE, CTL_EOL);

        /* MSL tuning subtree */

        sysctl_createv(clog, 0, NULL, &mslt_node,
                       CTLFLAG_PERMANENT, CTLTYPE_NODE, "mslt",
                       SYSCTL_DESCR("MSL Tuning for TIME_WAIT truncation"),
                       NULL, 0, NULL, 0,
                       CTL_NET, pf, IPPROTO_TCP, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, &mslt_node, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "enable",
                       SYSCTL_DESCR("Enable TIME_WAIT truncation"),
                       NULL, 0, &tcp_msl_enable, 0, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, &mslt_node, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "loopback",
                       SYSCTL_DESCR("MSL value to use for loopback connections"),
                       NULL, 0, &tcp_msl_loop, 0, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, &mslt_node, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "local",
                       SYSCTL_DESCR("MSL value to use for local connections"),
                       NULL, 0, &tcp_msl_local, 0, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, &mslt_node, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "remote",
                       SYSCTL_DESCR("MSL value to use for remote connections"),
                       NULL, 0, &tcp_msl_remote, 0, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, &mslt_node, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "remote_threshold",
                       SYSCTL_DESCR("RTT estimate value to promote local to remote"),
                       NULL, 0, &tcp_msl_remote_threshold, 0, CTL_CREATE, CTL_EOL);

        /* vestigial TIME_WAIT tuning subtree */

        sysctl_createv(clog, 0, NULL, &vtw_node,
                       CTLFLAG_PERMANENT, CTLTYPE_NODE, "vtw",
                       SYSCTL_DESCR("Tuning for Vestigial TIME_WAIT"),
                       NULL, 0, NULL, 0,
                       CTL_NET, pf, IPPROTO_TCP, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, &vtw_node, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "enable",
                       SYSCTL_DESCR("Enable Vestigial TIME_WAIT"),
                       sysctl_tcp_vtw_enable, 0,
                       (pf == AF_INET) ? &tcp4_vtw_enable : &tcp6_vtw_enable,
                       0, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, &vtw_node, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READONLY,
                       CTLTYPE_INT, "entries",
                       SYSCTL_DESCR("Maximum number of vestigial TIME_WAIT entries"),
                       NULL, 0, &tcp_vtw_entries, 0, CTL_CREATE, CTL_EOL);
}

void
tcp_usrreq_init(void)
{

        sysctl_net_inet_tcp_setup2(NULL, PF_INET, "inet", "tcp");
#ifdef INET6
        sysctl_net_inet_tcp_setup2(NULL, PF_INET6, "inet6", "tcp6");
#endif
}

PR_WRAP_USRREQS(tcp)
#define tcp_attach      tcp_attach_wrapper
#define tcp_detach      tcp_detach_wrapper
#define tcp_accept      tcp_accept_wrapper
#define tcp_bind        tcp_bind_wrapper
#define tcp_listen      tcp_listen_wrapper
#define tcp_connect     tcp_connect_wrapper
#define tcp_connect2    tcp_connect2_wrapper
#define tcp_disconnect  tcp_disconnect_wrapper
#define tcp_shutdown    tcp_shutdown_wrapper
#define tcp_abort       tcp_abort_wrapper
#define tcp_ioctl       tcp_ioctl_wrapper
#define tcp_stat        tcp_stat_wrapper
#define tcp_peeraddr    tcp_peeraddr_wrapper
#define tcp_sockaddr    tcp_sockaddr_wrapper
#define tcp_rcvd        tcp_rcvd_wrapper
#define tcp_recvoob     tcp_recvoob_wrapper
#define tcp_send        tcp_send_wrapper
#define tcp_sendoob     tcp_sendoob_wrapper
#define tcp_purgeif     tcp_purgeif_wrapper

const struct pr_usrreqs tcp_usrreqs = {
        .pr_attach      = tcp_attach,
        .pr_detach      = tcp_detach,
        .pr_accept      = tcp_accept,
        .pr_bind        = tcp_bind,
        .pr_listen      = tcp_listen,
        .pr_connect     = tcp_connect,
        .pr_connect2    = tcp_connect2,
        .pr_disconnect  = tcp_disconnect,
        .pr_shutdown    = tcp_shutdown,
        .pr_abort       = tcp_abort,
        .pr_ioctl       = tcp_ioctl,
        .pr_stat        = tcp_stat,
        .pr_peeraddr    = tcp_peeraddr,
        .pr_sockaddr    = tcp_sockaddr,
        .pr_rcvd        = tcp_rcvd,
        .pr_recvoob     = tcp_recvoob,
        .pr_send        = tcp_send,
        .pr_sendoob     = tcp_sendoob,
        .pr_purgeif     = tcp_purgeif,
};