xref: /src/sys/netinet/in_pcb.c

/*	$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);
}