/*      $NetBSD: in_pcb.c,v 1.202 2022/11/04 09:05:41 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) 1998, 2011 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Coyote Point Systems, Inc.
 * This code is derived from software contributed to The NetBSD Foundation
 * by Public Access Networks Corporation ("Panix").  It was developed under
 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
 *
 * 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, 1991, 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.
 *
 *      @(#)in_pcb.c    8.4 (Berkeley) 5/24/95
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: in_pcb.c,v 1.202 2022/11/04 09:05:41 ozaki-r Exp $");

#ifdef _KERNEL_OPT
#include "opt_inet.h"
#include "opt_ipsec.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/ioctl.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/once.h>
#include <sys/pool.h>
#include <sys/proc.h>
#include <sys/kauth.h>
#include <sys/uidinfo.h>
#include <sys/domain.h>

#include <net/if.h>
#include <net/route.h>

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

#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_pcb.h>
#endif

#ifdef IPSEC
#include <netipsec/ipsec.h>
#include <netipsec/key.h>
#endif /* IPSEC */

#include <netinet/tcp_vtw.h>

struct  in_addr zeroin_addr;

#define INPCBHASH_PORT(table, lport) \
        &(table)->inpt_porthashtbl[ntohs(lport) & (table)->inpt_porthash]
#define INPCBHASH_BIND(table, laddr, lport) \
        &(table)->inpt_bindhashtbl[ \
            ((ntohl((laddr).s_addr) + ntohs(lport))) & (table)->inpt_bindhash]
#define INPCBHASH_CONNECT(table, faddr, fport, laddr, lport) \
        &(table)->inpt_connecthashtbl[ \
            ((ntohl((faddr).s_addr) + ntohs(fport)) + \
             (ntohl((laddr).s_addr) + ntohs(lport))) & (table)->inpt_connecthash]

int     anonportmin = IPPORT_ANONMIN;
int     anonportmax = IPPORT_ANONMAX;
int     lowportmin  = IPPORT_RESERVEDMIN;
int     lowportmax  = IPPORT_RESERVEDMAX;

static pool_cache_t     in4pcb_pool_cache;
#ifdef INET6
static pool_cache_t     in6pcb_pool_cache;
#endif

static int
inpcb_poolinit(void)
{

        in4pcb_pool_cache = pool_cache_init(sizeof(struct in4pcb), coherency_unit,
            0, 0, "in4pcbpl", NULL, IPL_NET, NULL, NULL, NULL);
#ifdef INET6
        in6pcb_pool_cache = pool_cache_init(sizeof(struct in6pcb), coherency_unit,
            0, 0, "in6pcbpl", NULL, IPL_NET, NULL, NULL, NULL);
#endif
        return 0;
}

void
inpcb_init(struct inpcbtable *table, int bindhashsize, int connecthashsize)
{
        static ONCE_DECL(control);

        TAILQ_INIT(&table->inpt_queue);
        table->inpt_porthashtbl = hashinit(bindhashsize, HASH_LIST, true,
            &table->inpt_porthash);
        table->inpt_bindhashtbl = hashinit(bindhashsize, HASH_LIST, true,
            &table->inpt_bindhash);
        table->inpt_connecthashtbl = hashinit(connecthashsize, HASH_LIST, true,
            &table->inpt_connecthash);
        table->inpt_lastlow = IPPORT_RESERVEDMAX;
        table->inpt_lastport = (in_port_t)anonportmax;

        RUN_ONCE(&control, inpcb_poolinit);
}

/*
 * inpcb_create: construct a new PCB and associated with a given socket.
 * Sets the PCB state to INP_ATTACHED and makes PCB globally visible.
 */
int
inpcb_create(struct socket *so, void *v)
{
        struct inpcbtable *table = v;
        struct inpcb *inp;
        int s;

#ifdef INET6
        KASSERT(soaf(so) == AF_INET || soaf(so) == AF_INET6);

        if (soaf(so) == AF_INET)
                inp = pool_cache_get(in4pcb_pool_cache, PR_NOWAIT);
        else
                inp = pool_cache_get(in6pcb_pool_cache, PR_NOWAIT);
#else
        KASSERT(soaf(so) == AF_INET);
        inp = pool_cache_get(in4pcb_pool_cache, PR_NOWAIT);
#endif
        if (inp == NULL)
                return ENOBUFS;
        if (soaf(so) == AF_INET)
                memset(inp, 0, sizeof(struct in4pcb));
#ifdef INET6
        else
                memset(inp, 0, sizeof(struct in6pcb));
#endif
        inp->inp_af = soaf(so);
        inp->inp_table = table;
        inp->inp_socket = so;
        inp->inp_portalgo = PORTALGO_DEFAULT;
        inp->inp_bindportonsend = false;

        if (inp->inp_af == AF_INET) {
                in4p_errormtu(inp) = -1;
                in4p_prefsrcip(inp).s_addr = INADDR_ANY;
        }
#ifdef INET6
        else {
                in6p_hops6(inp) = -1;   /* use kernel default */
                if (ip6_v6only)
                        inp->inp_flags |= IN6P_IPV6_V6ONLY;
        }
#endif
#if defined(IPSEC)
        if (ipsec_enabled) {
                int error = ipsec_init_pcbpolicy(so, &inp->inp_sp);
                if (error != 0) {
#ifdef INET6
                        if (inp->inp_af == AF_INET)
                                pool_cache_put(in4pcb_pool_cache, inp);
                        else
                                pool_cache_put(in6pcb_pool_cache, inp);
#else
                        KASSERT(inp->inp_af == AF_INET);
                        pool_cache_put(in4pcb_pool_cache, inp);
#endif
                        return error;
                }
                inp->inp_sp->sp_inp = inp;
        }
#endif
        so->so_pcb = inp;
        s = splsoftnet();
        TAILQ_INSERT_HEAD(&table->inpt_queue, inp, inp_queue);
        LIST_INSERT_HEAD(INPCBHASH_PORT(table, inp->inp_lport), inp,
            inp_lhash);
        inpcb_set_state(inp, INP_ATTACHED);
        splx(s);
        return 0;
}

static int
inpcb_set_port(struct sockaddr_in *sin, struct inpcb *inp, kauth_cred_t cred)
{
        struct inpcbtable *table = inp->inp_table;
        struct socket *so = inp->inp_socket;
        in_port_t *lastport;
        in_port_t lport = 0;
        enum kauth_network_req req;
        int error;

        if (inp->inp_flags & INP_LOWPORT) {
#ifndef IPNOPRIVPORTS
                req = KAUTH_REQ_NETWORK_BIND_PRIVPORT;
#else
                req = KAUTH_REQ_NETWORK_BIND_PORT;
#endif

                lastport = &table->inpt_lastlow;
        } else {
                req = KAUTH_REQ_NETWORK_BIND_PORT;

                lastport = &table->inpt_lastport;
        }

        /* XXX-kauth: KAUTH_REQ_NETWORK_BIND_AUTOASSIGN_{,PRIV}PORT */
        error = kauth_authorize_network(cred, KAUTH_NETWORK_BIND, req, so, sin,
            NULL);
        if (error)
                return EACCES;

       /*
        * Use RFC6056 randomized port selection
        */
        error = portalgo_randport(&lport, inp, cred);
        if (error)
                return error;

        inp->inp_flags |= INP_ANONPORT;
        *lastport = lport;
        lport = htons(lport);
        inp->inp_lport = lport;
        inpcb_set_state(inp, INP_BOUND);

        return 0;
}

int
inpcb_bindableaddr(const struct inpcb *inp, struct sockaddr_in *sin,
    kauth_cred_t cred)
{
        int error = EADDRNOTAVAIL;
        struct ifaddr *ifa = NULL;
        int s;

        if (sin->sin_family != AF_INET)
                return EAFNOSUPPORT;

        s = pserialize_read_enter();
        if (IN_MULTICAST(sin->sin_addr.s_addr)) {
                /* Always succeed; port reuse handled in inpcb_bind_port(). */
        } else if (!in_nullhost(sin->sin_addr)) {
                struct in_ifaddr *ia;

                ia = in_get_ia(sin->sin_addr);
                /* check for broadcast addresses */
                if (ia == NULL) {
                        ifa = ifa_ifwithaddr(sintosa(sin));
                        if (ifa != NULL)
                                ia = ifatoia(ifa);
                        else if ((inp->inp_flags & INP_BINDANY) != 0) {
                                error = 0;
                                goto error;
                        }
                }
                if (ia == NULL)
                        goto error;
                if (ia->ia4_flags & IN_IFF_DUPLICATED)
                        goto error;
        }
        error = 0;
 error:
        pserialize_read_exit(s);
        return error;
}

static int
inpcb_bind_addr(struct inpcb *inp, struct sockaddr_in *sin, kauth_cred_t cred)
{
        int error;

        error = inpcb_bindableaddr(inp, sin, cred);
        if (error == 0)
                in4p_laddr(inp) = sin->sin_addr;
        return error;
}

static int
inpcb_bind_port(struct inpcb *inp, struct sockaddr_in *sin, kauth_cred_t cred)
{
        struct inpcbtable *table = inp->inp_table;
        struct socket *so = inp->inp_socket;
        int reuseport = (so->so_options & SO_REUSEPORT);
        int wild = 0, error;

        if (IN_MULTICAST(sin->sin_addr.s_addr)) {
                /*
                 * Treat SO_REUSEADDR as SO_REUSEPORT for multicast;
                 * allow complete duplication of binding if
                 * SO_REUSEPORT is set, or if SO_REUSEADDR is set
                 * and a multicast address is bound on both
                 * new and duplicated sockets.
                 */
                if (so->so_options & (SO_REUSEADDR | SO_REUSEPORT))
                        reuseport = SO_REUSEADDR|SO_REUSEPORT;
        } 

        if (sin->sin_port == 0) {
                error = inpcb_set_port(sin, inp, cred);
                if (error)
                        return error;
        } else {
                struct inpcb *t;
                vestigial_inpcb_t vestige;
#ifdef INET6
                struct inpcb *t6;
                struct in6_addr mapped;
#endif
                enum kauth_network_req req;

                if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0)
                        wild = 1;

#ifndef IPNOPRIVPORTS
                if (ntohs(sin->sin_port) < IPPORT_RESERVED)
                        req = KAUTH_REQ_NETWORK_BIND_PRIVPORT;
                else
#endif /* !IPNOPRIVPORTS */
                        req = KAUTH_REQ_NETWORK_BIND_PORT;

                error = kauth_authorize_network(cred, KAUTH_NETWORK_BIND, req,
                    so, sin, NULL);
                if (error)
                        return EACCES;

#ifdef INET6
                in6_in_2_v4mapin6(&sin->sin_addr, &mapped);
                t6 = in6pcb_lookup_local(table, &mapped, sin->sin_port, wild, &vestige);
                if (t6 && (reuseport & t6->inp_socket->so_options) == 0)
                        return EADDRINUSE;
                if (!t6 && vestige.valid) {
                    if (!!reuseport != !!vestige.reuse_port) {
                        return EADDRINUSE;
                    }
                }
#endif

                /* XXX-kauth */
                if (so->so_uidinfo->ui_uid && !IN_MULTICAST(sin->sin_addr.s_addr)) {
                        t = inpcb_lookup_local(table, sin->sin_addr, sin->sin_port, 1, &vestige);
                        /*
                         * XXX: investigate ramifications of loosening this
                         *      restriction so that as long as both ports have
                         *      SO_REUSEPORT allow the bind
                         */
                        if (t &&
                            (!in_nullhost(sin->sin_addr) ||
                             !in_nullhost(in4p_laddr(t)) ||
                             (t->inp_socket->so_options & SO_REUSEPORT) == 0)
                            && (so->so_uidinfo->ui_uid != t->inp_socket->so_uidinfo->ui_uid)) {
                                return EADDRINUSE;
                        }
                        if (!t && vestige.valid) {
                                if ((!in_nullhost(sin->sin_addr)
                                     || !in_nullhost(vestige.laddr.v4)
                                     || !vestige.reuse_port)
                                    && so->so_uidinfo->ui_uid != vestige.uid) {
                                        return EADDRINUSE;
                                }
                        }
                }
                t = inpcb_lookup_local(table, sin->sin_addr, sin->sin_port, wild, &vestige);
                if (t && (reuseport & t->inp_socket->so_options) == 0)
                        return EADDRINUSE;
                if (!t
                    && vestige.valid
                    && !(reuseport && vestige.reuse_port))
                        return EADDRINUSE;

                inp->inp_lport = sin->sin_port;
                inpcb_set_state(inp, INP_BOUND);
        }

        LIST_REMOVE(inp, inp_lhash);
        LIST_INSERT_HEAD(INPCBHASH_PORT(table, inp->inp_lport), inp,
            inp_lhash);

        return 0;
}

/*
 * inpcb_bind: assign a local IP address and port number to the PCB.
 *
 * If the address is not a wildcard, verify that it corresponds to a
 * local interface.  If a port is specified and it is privileged, then
 * check the permission.  Check whether the address or port is in use,
 * and if so, whether we can re-use them.
 */
int
inpcb_bind(void *v, struct sockaddr_in *sin, struct lwp *l)
{
        struct inpcb *inp = v;
        struct sockaddr_in lsin;
        int error;

        if (inp->inp_af != AF_INET)
                return EINVAL;

        if (inp->inp_lport || !in_nullhost(in4p_laddr(inp)))
                return EINVAL;

        if (NULL != sin) {
                if (sin->sin_len != sizeof(*sin))
                        return EINVAL;
        } else {
                lsin = *((const struct sockaddr_in *)
                    inp->inp_socket->so_proto->pr_domain->dom_sa_any);
                sin = &lsin;
        }

        /* Bind address. */
        error = inpcb_bind_addr(inp, sin, l->l_cred);
        if (error)
                return error;

        /* Bind port. */
        error = inpcb_bind_port(inp, sin, l->l_cred);
        if (error) {
                in4p_laddr(inp).s_addr = INADDR_ANY;

                return error;
        }

        return 0;
}

/*
 * inpcb_connect: connect from a socket to a specified address, i.e.,
 * assign a foreign IP address and port number to the PCB.
 *
 * Both address and port must be specified in the name argument.
 * If there is no local address for this socket yet, then pick one.
 */
int
inpcb_connect(void *v, struct sockaddr_in *sin, struct lwp *l)
{
        struct inpcb *inp = v;
        vestigial_inpcb_t vestige;
        int error;
        struct in_addr laddr;

        if (inp->inp_af != AF_INET)
                return EINVAL;

        if (sin->sin_len != sizeof (*sin))
                return EINVAL;
        if (sin->sin_family != AF_INET)
                return EAFNOSUPPORT;
        if (sin->sin_port == 0)
                return EADDRNOTAVAIL;

        if (IN_MULTICAST(sin->sin_addr.s_addr) &&
            inp->inp_socket->so_type == SOCK_STREAM)
                return EADDRNOTAVAIL;

        if (!IN_ADDRLIST_READER_EMPTY()) {
                /*
                 * If the destination address is INADDR_ANY,
                 * use any local address (likely loopback).
                 * If the supplied address is INADDR_BROADCAST,
                 * use the broadcast address of an interface
                 * which supports broadcast. (loopback does not)
                 */

                if (in_nullhost(sin->sin_addr)) {
                        /* XXX racy */
                        sin->sin_addr =
                            IN_ADDRLIST_READER_FIRST()->ia_addr.sin_addr;
                } else if (sin->sin_addr.s_addr == INADDR_BROADCAST) {
                        struct in_ifaddr *ia;
                        int s = pserialize_read_enter();
                        IN_ADDRLIST_READER_FOREACH(ia) {
                                if (ia->ia_ifp->if_flags & IFF_BROADCAST) {
                                        sin->sin_addr =
                                            ia->ia_broadaddr.sin_addr;
                                        break;
                                }
                        }
                        pserialize_read_exit(s);
                }
        }
        /*
         * If we haven't bound which network number to use as ours,
         * we will use the number of the outgoing interface.
         * This depends on having done a routing lookup, which
         * we will probably have to do anyway, so we might
         * as well do it now.  On the other hand if we are
         * sending to multiple destinations we may have already
         * done the lookup, so see if we can use the route
         * from before.  In any case, we only
         * chose a port number once, even if sending to multiple
         * destinations.
         */
        if (in_nullhost(in4p_laddr(inp))) {
                int xerror;
                struct in_ifaddr *ia, *_ia;
                int s;
                struct psref psref;
                int bound;

                bound = curlwp_bind();
                ia = in_selectsrc(sin, &inp->inp_route,
                    inp->inp_socket->so_options, inp->inp_moptions, &xerror,
                    &psref);
                if (ia == NULL) {
                        curlwp_bindx(bound);
                        if (xerror == 0)
                                xerror = EADDRNOTAVAIL;
                        return xerror;
                }
                s = pserialize_read_enter();
                _ia = in_get_ia(IA_SIN(ia)->sin_addr);
                if (_ia == NULL && (inp->inp_flags & INP_BINDANY) == 0) {
                        pserialize_read_exit(s);
                        ia4_release(ia, &psref);
                        curlwp_bindx(bound);
                        return EADDRNOTAVAIL;
                }
                pserialize_read_exit(s);
                laddr = IA_SIN(ia)->sin_addr;
                ia4_release(ia, &psref);
                curlwp_bindx(bound);
        } else
                laddr = in4p_laddr(inp);
        if (inpcb_lookup(inp->inp_table, sin->sin_addr, sin->sin_port,
                                 laddr, inp->inp_lport, &vestige) != NULL ||
            vestige.valid) {
                return EADDRINUSE;
        }
        if (in_nullhost(in4p_laddr(inp))) {
                if (inp->inp_lport == 0) {
                        error = inpcb_bind(inp, NULL, l);
                        /*
                         * This used to ignore the return value
                         * completely, but we need to check for
                         * ephemeral port shortage.
                         * And attempts to request low ports if not root.
                         */
                        if (error != 0)
                                return error;
                }
                in4p_laddr(inp) = laddr;
        }
        in4p_faddr(inp) = sin->sin_addr;
        inp->inp_fport = sin->sin_port;

        /* Late bind, if needed */
        if (inp->inp_bindportonsend) {
                struct sockaddr_in lsin = *((const struct sockaddr_in *)
                    inp->inp_socket->so_proto->pr_domain->dom_sa_any);
                lsin.sin_addr = in4p_laddr(inp);
                lsin.sin_port = 0;

                if ((error = inpcb_bind_port(inp, &lsin, l->l_cred)) != 0)
                        return error;
        }

        inpcb_set_state(inp, INP_CONNECTED);
#if defined(IPSEC)
        if (ipsec_enabled && inp->inp_socket->so_type == SOCK_STREAM)
                ipsec_pcbconn(inp->inp_sp);
#endif
        return 0;
}

/*
 * inpcb_disconnect: remove any foreign IP/port association.
 *
 * Note: destroys the PCB if socket was closed.
 */
void
inpcb_disconnect(void *v)
{
        struct inpcb *inp = v;

        if (inp->inp_af != AF_INET)
                return;

        in4p_faddr(inp) = zeroin_addr;
        inp->inp_fport = 0;
        inpcb_set_state(inp, INP_BOUND);
#if defined(IPSEC)
        if (ipsec_enabled)
                ipsec_pcbdisconn(inp->inp_sp);
#endif
        if (inp->inp_socket->so_state & SS_NOFDREF)
                inpcb_destroy(inp);
}

/*
 * inpcb_destroy: destroy PCB as well as the associated socket.
 */
void
inpcb_destroy(void *v)
{
        struct inpcb *inp = v;
        struct socket *so = inp->inp_socket;
        int s;

        KASSERT(inp->inp_af == AF_INET || inp->inp_af == AF_INET6);

#if defined(IPSEC)
        if (ipsec_enabled)
                ipsec_delete_pcbpolicy(inp);
#endif
        so->so_pcb = NULL;

        s = splsoftnet();
        inpcb_set_state(inp, INP_ATTACHED);
        LIST_REMOVE(inp, inp_lhash);
        TAILQ_REMOVE(&inp->inp_table->inpt_queue, inp, inp_queue);
        splx(s);

        if (inp->inp_options) {
                m_free(inp->inp_options);
        }
        rtcache_free(&inp->inp_route);
        ip_freemoptions(inp->inp_moptions);
#ifdef INET6
        if (inp->inp_af == AF_INET6) {
                if (in6p_outputopts(inp) != NULL) {
                        ip6_clearpktopts(in6p_outputopts(inp), -1);
                        free(in6p_outputopts(inp), M_IP6OPT);
                }
                ip6_freemoptions(in6p_moptions(inp));
        }
#endif
        sofree(so);                     /* drops the socket's lock */

#ifdef INET6
        if (inp->inp_af == AF_INET)
                pool_cache_put(in4pcb_pool_cache, inp);
        else
                pool_cache_put(in6pcb_pool_cache, inp);
#else
        KASSERT(inp->inp_af == AF_INET);
        pool_cache_put(in4pcb_pool_cache, inp);
#endif
        mutex_enter(softnet_lock);      /* reacquire the softnet_lock */
}

/*
 * inpcb_fetch_sockaddr: fetch the local IP address and port number.
 */
void
inpcb_fetch_sockaddr(struct inpcb *inp, struct sockaddr_in *sin)
{

        if (inp->inp_af != AF_INET)
                return;

        sockaddr_in_init(sin, &in4p_laddr(inp), inp->inp_lport);
}

/*
 * inpcb_fetch_peeraddr: fetch the foreign IP address and port number.
 */
void
inpcb_fetch_peeraddr(struct inpcb *inp, struct sockaddr_in *sin)
{

        if (inp->inp_af != AF_INET)
                return;

        sockaddr_in_init(sin, &in4p_faddr(inp), inp->inp_fport);
}

/*
 * inpcb_notify: pass some notification to all connections of a protocol
 * associated with destination address.  The local address and/or port
 * numbers may be specified to limit the search.  The "usual action" will
 * be taken, depending on the command.
 *
 * The caller must filter any commands that are not interesting (e.g.,
 * no error in the map).  Call the protocol specific routine (if any) to
 * report any errors for each matching socket.
 *
 * Must be called at splsoftnet.
 */
int
inpcb_notify(struct inpcbtable *table, struct in_addr faddr, u_int fport_arg,
    struct in_addr laddr, u_int lport_arg, int errno,
    void (*notify)(struct inpcb *, int))
{
        struct inpcbhead *head;
        struct inpcb *inp;
        in_port_t fport = fport_arg, lport = lport_arg;
        int nmatch;

        if (in_nullhost(faddr) || notify == NULL)
                return 0;

        nmatch = 0;
        head = INPCBHASH_CONNECT(table, faddr, fport, laddr, lport);
        LIST_FOREACH(inp, head, inp_hash) {
                if (inp->inp_af != AF_INET)
                        continue;

                if (in_hosteq(in4p_faddr(inp), faddr) &&
                    inp->inp_fport == fport &&
                    inp->inp_lport == lport &&
                    in_hosteq(in4p_laddr(inp), laddr)) {
                        (*notify)(inp, errno);
                        nmatch++;
                }
        }
        return nmatch;
}

void
inpcb_notifyall(struct inpcbtable *table, struct in_addr faddr, int errno,
    void (*notify)(struct inpcb *, int))
{
        struct inpcb *inp;

        if (in_nullhost(faddr) || notify == NULL)
                return;

        TAILQ_FOREACH(inp, &table->inpt_queue, inp_queue) {
                if (inp->inp_af != AF_INET)
                        continue;
                if (in_hosteq(in4p_faddr(inp), faddr))
                        (*notify)(inp, errno);
        }
}

void
in_purgeifmcast(struct ip_moptions *imo, struct ifnet *ifp)
{
        int i, gap;

        /* The owner of imo should be protected by solock */
        KASSERT(ifp != NULL);

        if (imo == NULL)
                return;

        /*
         * Unselect the outgoing interface if it is being
         * detached.
         */
        if (imo->imo_multicast_if_index == ifp->if_index)
                imo->imo_multicast_if_index = 0;

        /*
         * Drop multicast group membership if we joined
         * through the interface being detached.
         */
        for (i = 0, gap = 0; i < imo->imo_num_memberships; i++) {
                if (imo->imo_membership[i]->inm_ifp == ifp) {
                        in_delmulti(imo->imo_membership[i]);
                        gap++;
                } else if (gap != 0)
                        imo->imo_membership[i - gap] = imo->imo_membership[i];
        }
        imo->imo_num_memberships -= gap;
}

void
inpcb_purgeif0(struct inpcbtable *table, struct ifnet *ifp)
{
        struct inpcb *inp;

        TAILQ_FOREACH(inp, &table->inpt_queue, inp_queue) {
                bool need_unlock = false;

                if (inp->inp_af != AF_INET)
                        continue;

                /* The caller holds either one of inps' lock */
                if (!inp_locked(inp)) {
                        inp_lock(inp);
                        need_unlock = true;
                }

                in_purgeifmcast(inp->inp_moptions, ifp);

                if (need_unlock)
                        inp_unlock(inp);
        }
}

void
inpcb_purgeif(struct inpcbtable *table, struct ifnet *ifp)
{
        struct rtentry *rt;
        struct inpcb *inp;

        TAILQ_FOREACH(inp, &table->inpt_queue, inp_queue) {
                if (inp->inp_af != AF_INET)
                        continue;
                if ((rt = rtcache_validate(&inp->inp_route)) != NULL &&
                    rt->rt_ifp == ifp) {
                        rtcache_unref(rt, &inp->inp_route);
                        inpcb_rtchange(inp, 0);
                } else
                        rtcache_unref(rt, &inp->inp_route);
        }
}

/*
 * inpcb_losing: check for alternatives when higher level complains about
 * service problems.  For now, invalidate cached routing information.
 * If the route was created dynamically (by a redirect), time to try a
 * default gateway again.
 */
void
inpcb_losing(struct inpcb *inp)
{
        struct rtentry *rt;
        struct rt_addrinfo info;

        if (inp->inp_af != AF_INET)
                return;

        if ((rt = rtcache_validate(&inp->inp_route)) == NULL)
                return;

        memset(&info, 0, sizeof(info));
        info.rti_info[RTAX_DST] = rtcache_getdst(&inp->inp_route);
        info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
        info.rti_info[RTAX_NETMASK] = rt_mask(rt);
        rt_missmsg(RTM_LOSING, &info, rt->rt_flags, 0);
        if (rt->rt_flags & RTF_DYNAMIC) {
                int error;
                struct rtentry *nrt;

                error = rtrequest(RTM_DELETE, rt_getkey(rt),
                    rt->rt_gateway, rt_mask(rt), rt->rt_flags, &nrt);
                rtcache_unref(rt, &inp->inp_route);
                if (error == 0) {
                        rt_newmsg_dynamic(RTM_DELETE, nrt);
                        rt_free(nrt);
                }
        } else
                rtcache_unref(rt, &inp->inp_route);
        /*
         * A new route can be allocated
         * the next time output is attempted.
         */
        rtcache_free(&inp->inp_route);
}

/*
 * inpcb_rtchange: after a routing change, flush old routing.
 * A new route can be allocated the next time output is attempted.
 */
void
inpcb_rtchange(struct inpcb *inp, int errno)
{

        if (inp->inp_af != AF_INET)
                return;

        rtcache_free(&inp->inp_route);

        /* XXX SHOULD NOTIFY HIGHER-LEVEL PROTOCOLS */
}

/*
 * inpcb_lookup_local: find a PCB by looking at the local port and matching
 * the local address or resolving the wildcards.  Primarily used to detect
 * when the local address is already in use.
 */
struct inpcb *
inpcb_lookup_local(struct inpcbtable *table, struct in_addr laddr,
                  u_int lport_arg, int lookup_wildcard, vestigial_inpcb_t *vp)
{
        struct inpcbhead *head;
        struct inpcb *inp;
        struct inpcb *match = NULL;
        int matchwild = 3;
        int wildcard;
        in_port_t lport = lport_arg;

        if (vp)
                vp->valid = 0;

        head = INPCBHASH_PORT(table, lport);
        LIST_FOREACH(inp, head, inp_lhash) {
                if (inp->inp_af != AF_INET)
                        continue;
                if (inp->inp_lport != lport)
                        continue;
                /*
                 * check if inp's faddr and laddr match with ours.
                 * our faddr is considered null.
                 * count the number of wildcard matches. (0 - 2)
                 *
                 *      null    null    match
                 *      A       null    wildcard match
                 *      null    B       wildcard match
                 *      A       B       non match
                 *      A       A       match
                 */
                wildcard = 0;
                if (!in_nullhost(in4p_faddr(inp)))
                        wildcard++;
                if (in_nullhost(in4p_laddr(inp))) {
                        if (!in_nullhost(laddr))
                                wildcard++;
                } else {
                        if (in_nullhost(laddr))
                                wildcard++;
                        else {
                                if (!in_hosteq(in4p_laddr(inp), laddr))
                                        continue;
                        }
                }
                if (wildcard && !lookup_wildcard)
                        continue;
                /*
                 * prefer an address with less wildcards.
                 */
                if (wildcard < matchwild) {
                        match = inp;
                        matchwild = wildcard;
                        if (matchwild == 0)
                                break;
                }
        }
        if (match && matchwild == 0)
                return match;

        if (vp && table->vestige) {
                void    *state = (*table->vestige->init_ports4)(laddr, lport_arg, lookup_wildcard);
                vestigial_inpcb_t better;
                bool has_better = false;

                while (table->vestige
                       && (*table->vestige->next_port4)(state, vp)) {

                        if (vp->lport != lport)
                                continue;
                        wildcard = 0;
                        if (!in_nullhost(vp->faddr.v4))
                                wildcard++;
                        if (in_nullhost(vp->laddr.v4)) {
                                if (!in_nullhost(laddr))
                                        wildcard++;
                        } else {
                                if (in_nullhost(laddr))
                                        wildcard++;
                                else {
                                        if (!in_hosteq(vp->laddr.v4, laddr))
                                                continue;
                                }
                        }
                        if (wildcard && !lookup_wildcard)
                                continue;
                        if (wildcard < matchwild) {
                                better = *vp;
                                has_better = true;

                                matchwild = wildcard;
                                if (matchwild == 0)
                                        break;
                        }
                }

                if (has_better) {
                        *vp = better;
                        return 0;
                }
        }

        return match;
}

#ifdef DIAGNOSTIC
int     inpcb_notifymiss = 0;
#endif

/*
 * inpcb_lookup: perform a full 4-tuple PCB lookup.
 */
struct inpcb *
inpcb_lookup(struct inpcbtable *table,
    struct in_addr faddr, u_int fport_arg,
    struct in_addr laddr, u_int lport_arg,
    vestigial_inpcb_t *vp)
{
        struct inpcbhead *head;
        struct inpcb *inp;
        in_port_t fport = fport_arg, lport = lport_arg;

        if (vp)
                vp->valid = 0;

        head = INPCBHASH_CONNECT(table, faddr, fport, laddr, lport);
        LIST_FOREACH(inp, head, inp_hash) {
                if (inp->inp_af != AF_INET)
                        continue;

                if (in_hosteq(in4p_faddr(inp), faddr) &&
                    inp->inp_fport == fport &&
                    inp->inp_lport == lport &&
                    in_hosteq(in4p_laddr(inp), laddr))
                        goto out;
        }
        if (vp && table->vestige) {
                if ((*table->vestige->lookup4)(faddr, fport_arg,
                                               laddr, lport_arg, vp))
                        return 0;
        }

#ifdef DIAGNOSTIC
        if (inpcb_notifymiss) {
                printf("inpcb_lookup: faddr=%08x fport=%d laddr=%08x lport=%d\n",
                    ntohl(faddr.s_addr), ntohs(fport),
                    ntohl(laddr.s_addr), ntohs(lport));
        }
#endif
        return 0;

out:
        /* Move this PCB to the head of hash chain. */
        if (inp != LIST_FIRST(head)) {
                LIST_REMOVE(inp, inp_hash);
                LIST_INSERT_HEAD(head, inp, inp_hash);
        }
        return inp;
}

/*
 * inpcb_lookup_bound: find a PCB by looking at the local address and port.
 * Primarily used to find the listening (i.e., already bound) socket.
 */
struct inpcb *
inpcb_lookup_bound(struct inpcbtable *table,
    struct in_addr laddr, u_int lport_arg)
{
        struct inpcbhead *head;
        struct inpcb *inp;
        in_port_t lport = lport_arg;

        head = INPCBHASH_BIND(table, laddr, lport);
        LIST_FOREACH(inp, head, inp_hash) {
                if (inp->inp_af != AF_INET)
                        continue;

                if (inp->inp_lport == lport &&
                    in_hosteq(in4p_laddr(inp), laddr))
                        goto out;
        }
        head = INPCBHASH_BIND(table, zeroin_addr, lport);
        LIST_FOREACH(inp, head, inp_hash) {
                if (inp->inp_af != AF_INET)
                        continue;

                if (inp->inp_lport == lport &&
                    in_hosteq(in4p_laddr(inp), zeroin_addr))
                        goto out;
        }
#ifdef DIAGNOSTIC
        if (inpcb_notifymiss) {
                printf("inpcb_lookup_bound: laddr=%08x lport=%d\n",
                    ntohl(laddr.s_addr), ntohs(lport));
        }
#endif
        return 0;

out:
        /* Move this PCB to the head of hash chain. */
        if (inp != LIST_FIRST(head)) {
                LIST_REMOVE(inp, inp_hash);
                LIST_INSERT_HEAD(head, inp, inp_hash);
        }
        return inp;
}

void
inpcb_set_state(struct inpcb *inp, int state)
{

#ifdef INET6
        if (inp->inp_af == AF_INET6) {
                in6pcb_set_state(inp, state);
                return;
        }
#else
        if (inp->inp_af != AF_INET)
                return;
#endif

        if (inp->inp_state > INP_ATTACHED)
                LIST_REMOVE(inp, inp_hash);

        switch (state) {
        case INP_BOUND:
                LIST_INSERT_HEAD(INPCBHASH_BIND(inp->inp_table,
                    in4p_laddr(inp), inp->inp_lport), inp,
                    inp_hash);
                break;
        case INP_CONNECTED:
                LIST_INSERT_HEAD(INPCBHASH_CONNECT(inp->inp_table,
                    in4p_faddr(inp), inp->inp_fport,
                    in4p_laddr(inp), inp->inp_lport), inp,
                    inp_hash);
                break;
        }

        inp->inp_state = state;
}

struct rtentry *
inpcb_rtentry(struct inpcb *inp)
{
        struct route *ro;
        union {
                struct sockaddr         dst;
                struct sockaddr_in      dst4;
        } u;

#ifdef INET6
        if (inp->inp_af == AF_INET6)
                return in6pcb_rtentry(inp);
#endif
        if (inp->inp_af != AF_INET)
                return NULL;

        ro = &inp->inp_route;

        sockaddr_in_init(&u.dst4, &in4p_faddr(inp), 0);
        return rtcache_lookup(ro, &u.dst);
}

void
inpcb_rtentry_unref(struct rtentry *rt, struct inpcb *inp)
{

        rtcache_unref(rt, &inp->inp_route);
}