xref: /openbsd/sys/netinet/in_pcb.c (revision 404b540a)

/*	$OpenBSD: in_pcb.c,v 1.106 2009/07/26 12:59:16 thib Exp $	*/
/*	$NetBSD: in_pcb.c,v 1.25 1996/02/13 23:41:53 christos Exp $	*/

/*
 * Copyright (c) 1982, 1986, 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. 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.
 *
 *	@(#)COPYRIGHT	1.1 (NRL) 17 January 1995
 *
 * NRL grants permission for redistribution and use in source and binary
 * forms, with or without modification, of the software and documentation
 * created at NRL provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgements:
 * 	This product includes software developed by the University of
 * 	California, Berkeley and its contributors.
 * 	This product includes software developed at the Information
 * 	Technology Division, US Naval Research Laboratory.
 * 4. Neither the name of the NRL nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL 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 NRL 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.
 *
 * The views and conclusions contained in the software and documentation
 * are those of the authors and should not be interpreted as representing
 * official policies, either expressed or implied, of the US Naval
 * Research Laboratory (NRL).
 */

#include "pf.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/proc.h>
#include <sys/domain.h>
#include <sys/pool.h>

#include <net/if.h>
#include <net/route.h>
#include <net/pfvar.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 <dev/rndvar.h>

#include <sys/mount.h>
#include <nfs/nfsproto.h>

#ifdef INET6
#include <netinet6/ip6_var.h>
#endif /* INET6 */
#ifdef IPSEC
#include <netinet/ip_esp.h>
#endif /* IPSEC */

struct	in_addr zeroin_addr;

extern int ipsec_auth_default_level;
extern int ipsec_esp_trans_default_level;
extern int ipsec_esp_network_default_level;
extern int ipsec_ipcomp_default_level;

/*
 * These configure the range of local port addresses assigned to
 * "unspecified" outgoing connections/packets/whatever.
 */
int ipport_firstauto = IPPORT_RESERVED;
int ipport_lastauto = IPPORT_USERRESERVED;
int ipport_hifirstauto = IPPORT_HIFIRSTAUTO;
int ipport_hilastauto = IPPORT_HILASTAUTO;

struct pool inpcb_pool;
int inpcb_pool_initialized = 0;

#define	INPCBHASH(table, faddr, fport, laddr, lport, rdom) \
	&(table)->inpt_hashtbl[(ntohl((faddr)->s_addr) + \
	ntohs((fport)) + ntohs((lport)) + (rdom)) & (table->inpt_hash)]

#define	IN6PCBHASH(table, faddr, fport, laddr, lport) \
	&(table)->inpt_hashtbl[(ntohl((faddr)->s6_addr32[0] ^ \
	(faddr)->s6_addr32[3]) + ntohs((fport)) + ntohs((lport))) & \
	(table->inpt_hash)]

#define	INPCBLHASH(table, lport, rdom) \
	&(table)->inpt_lhashtbl[(ntohs((lport)) + (rdom)) & table->inpt_lhash]

void
in_pcbinit(table, hashsize)
	struct inpcbtable *table;
	int hashsize;
{

	CIRCLEQ_INIT(&table->inpt_queue);
	table->inpt_hashtbl = hashinit(hashsize, M_PCB, M_NOWAIT,
	    &table->inpt_hash);
	if (table->inpt_hashtbl == NULL)
		panic("in_pcbinit: hashinit failed");
	table->inpt_lhashtbl = hashinit(hashsize, M_PCB, M_NOWAIT,
	    &table->inpt_lhash);
	if (table->inpt_lhashtbl == NULL)
		panic("in_pcbinit: hashinit failed for lport");
	table->inpt_lastport = 0;
}

struct baddynamicports baddynamicports;

/*
 * Check if the specified port is invalid for dynamic allocation.
 */
int
in_baddynamic(u_int16_t port, u_int16_t proto)
{
	switch (proto) {
	case IPPROTO_TCP:
		return (DP_ISSET(baddynamicports.tcp, port));
	case IPPROTO_UDP:
#ifdef IPSEC
		/* Cannot preset this as it is a sysctl */
		if (port == udpencap_port)
			return (1);
#endif
		return (DP_ISSET(baddynamicports.udp, port));
	default:
		return (0);
	}
}

int
in_pcballoc(so, v)
	struct socket *so;
	void *v;
{
	struct inpcbtable *table = v;
	struct inpcb *inp;
	int s;

	if (inpcb_pool_initialized == 0) {
		pool_init(&inpcb_pool, sizeof(struct inpcb), 0, 0, 0,
		    "inpcbpl", NULL);
		inpcb_pool_initialized = 1;
	}
	inp = pool_get(&inpcb_pool, PR_NOWAIT);
	if (inp == NULL)
		return (ENOBUFS);
	bzero((caddr_t)inp, sizeof(*inp));
	inp->inp_table = table;
	inp->inp_socket = so;
	inp->inp_seclevel[SL_AUTH] = ipsec_auth_default_level;
	inp->inp_seclevel[SL_ESP_TRANS] = ipsec_esp_trans_default_level;
	inp->inp_seclevel[SL_ESP_NETWORK] = ipsec_esp_network_default_level;
	inp->inp_seclevel[SL_IPCOMP] = ipsec_ipcomp_default_level;
	s = splnet();
	CIRCLEQ_INSERT_HEAD(&table->inpt_queue, inp, inp_queue);
	LIST_INSERT_HEAD(INPCBLHASH(table, inp->inp_lport, inp->inp_rdomain),
	    inp, inp_lhash);
	LIST_INSERT_HEAD(INPCBHASH(table, &inp->inp_faddr, inp->inp_fport,
	    &inp->inp_laddr, inp->inp_lport, inp->inp_rdomain), inp, inp_hash);
	splx(s);
	so->so_pcb = inp;
	inp->inp_hops = -1;

#ifdef INET6
	/*
	 * Small change in this function to set the INP_IPV6 flag so routines
	 * outside pcb-specific routines don't need to use sotopf(), and all
	 * of its pointer chasing, later.
	 */
	if (sotopf(so) == PF_INET6)
		inp->inp_flags = INP_IPV6;
	inp->in6p_cksum = -1;
#endif /* INET6 */
	return (0);
}

int
in_pcbbind(v, nam, p)
	void *v;
	struct mbuf *nam;
	struct proc *p;
{
	struct inpcb *inp = v;
	struct socket *so = inp->inp_socket;
	struct inpcbtable *table = inp->inp_table;
	u_int16_t *lastport = &inp->inp_table->inpt_lastport;
	struct sockaddr_in *sin;
	u_int16_t lport = 0;
	int wild = 0, reuseport = (so->so_options & SO_REUSEPORT);
	int error;

#ifdef INET6
	if (sotopf(so) == PF_INET6)
		return in6_pcbbind(inp, nam, p);
#endif /* INET6 */

	if (TAILQ_EMPTY(&in_ifaddr))
		return (EADDRNOTAVAIL);
	if (inp->inp_lport || inp->inp_laddr.s_addr != INADDR_ANY)
		return (EINVAL);
	if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0 &&
	    ((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 ||
	     (so->so_options & SO_ACCEPTCONN) == 0))
		wild = INPLOOKUP_WILDCARD;
	if (nam) {
		sin = mtod(nam, struct sockaddr_in *);
		if (nam->m_len != sizeof (*sin))
			return (EINVAL);
#ifdef notdef
		/*
		 * We should check the family, but old programs
		 * incorrectly fail to initialize it.
		 */
		if (sin->sin_family != AF_INET)
			return (EAFNOSUPPORT);
#endif
		lport = sin->sin_port;
		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)
				reuseport = SO_REUSEADDR|SO_REUSEPORT;
		} else if (sin->sin_addr.s_addr != INADDR_ANY) {
			sin->sin_port = 0;		/* yech... */
			if (!(so->so_options & SO_BINDANY) &&
			    in_iawithaddr(sin->sin_addr, NULL,
			    inp->inp_rdomain) == 0)
				return (EADDRNOTAVAIL);
		}
		if (lport) {
			struct inpcb *t;

			/* GROSS */
			if (ntohs(lport) < IPPORT_RESERVED &&
			    (error = suser(p, 0)))
				return (EACCES);
			if (so->so_euid) {
				t = in_pcblookup(table, &zeroin_addr, 0,
				    &sin->sin_addr, lport, INPLOOKUP_WILDCARD,
				    inp->inp_rdomain);
				if (t && (so->so_euid != t->inp_socket->so_euid))
					return (EADDRINUSE);
			}
			t = in_pcblookup(table, &zeroin_addr, 0,
			    &sin->sin_addr, lport, wild, inp->inp_rdomain);
			if (t && (reuseport & t->inp_socket->so_options) == 0)
				return (EADDRINUSE);
		}
		inp->inp_laddr = sin->sin_addr;
	}
	if (lport == 0) {
		u_int16_t first, last;
		int count;

		if (inp->inp_flags & INP_HIGHPORT) {
			first = ipport_hifirstauto;	/* sysctl */
			last = ipport_hilastauto;
		} else if (inp->inp_flags & INP_LOWPORT) {
			if ((error = suser(p, 0)))
				return (EACCES);
			first = IPPORT_RESERVED-1; /* 1023 */
			last = 600;		   /* not IPPORT_RESERVED/2 */
		} else {
			first = ipport_firstauto;	/* sysctl */
			last  = ipport_lastauto;
		}

		/*
		 * Simple check to ensure all ports are not used up causing
		 * a deadlock here.
		 *
		 * We split the two cases (up and down) so that the direction
		 * is not being tested on each round of the loop.
		 */

		if (first > last) {
			/*
			 * counting down
			 */
			count = first - last;
			if (count)
				*lastport = first - arc4random_uniform(count);

			do {
				if (count-- < 0)	/* completely used? */
					return (EADDRNOTAVAIL);
				--*lastport;
				if (*lastport > first || *lastport < last)
					*lastport = first;
				lport = htons(*lastport);
			} while (in_baddynamic(*lastport, so->so_proto->pr_protocol) ||
			    in_pcblookup(table, &zeroin_addr, 0,
			    &inp->inp_laddr, lport, wild, inp->inp_rdomain));
		} else {
			/*
			 * counting up
			 */
			count = last - first;
			if (count)
				*lastport = first + arc4random_uniform(count);

			do {
				if (count-- < 0)	/* completely used? */
					return (EADDRNOTAVAIL);
				++*lastport;
				if (*lastport < first || *lastport > last)
					*lastport = first;
				lport = htons(*lastport);
			} while (in_baddynamic(*lastport, so->so_proto->pr_protocol) ||
			    in_pcblookup(table, &zeroin_addr, 0,
			    &inp->inp_laddr, lport, wild, inp->inp_rdomain));
		}
	}
	inp->inp_lport = lport;
	in_pcbrehash(inp);
	return (0);
}

/*
 * Connect from a socket to a specified address.
 * Both address and port must be specified in argument sin.
 * If don't have a local address for this socket yet,
 * then pick one.
 */
int
in_pcbconnect(v, nam)
	void *v;
	struct mbuf *nam;
{
	struct inpcb *inp = v;
	struct sockaddr_in *ifaddr = NULL;
	struct sockaddr_in *sin = mtod(nam, struct sockaddr_in *);

#ifdef INET6
	if (sotopf(inp->inp_socket) == PF_INET6)
		return (in6_pcbconnect(inp, nam));
	if ((inp->inp_flags & INP_IPV6) != 0)
		panic("IPv6 pcb passed into in_pcbconnect");
#endif /* INET6 */

	if (nam->m_len != sizeof (*sin))
		return (EINVAL);
	if (sin->sin_family != AF_INET)
		return (EAFNOSUPPORT);
	if (sin->sin_port == 0)
		return (EADDRNOTAVAIL);
	if (!TAILQ_EMPTY(&in_ifaddr)) {
		/*
		 * If the destination address is INADDR_ANY,
		 * use the primary local address.
		 * If the supplied address is INADDR_BROADCAST,
		 * and the primary interface supports broadcast,
		 * choose the broadcast address for that interface.
		 */
		if (sin->sin_addr.s_addr == INADDR_ANY)
			sin->sin_addr = TAILQ_FIRST(&in_ifaddr)->ia_addr.sin_addr;
		else if (sin->sin_addr.s_addr == INADDR_BROADCAST &&
		  (TAILQ_FIRST(&in_ifaddr)->ia_ifp->if_flags & IFF_BROADCAST))
			sin->sin_addr = TAILQ_FIRST(&in_ifaddr)->ia_broadaddr.sin_addr;
	}
	if (inp->inp_laddr.s_addr == INADDR_ANY) {
		int error;
		ifaddr = in_selectsrc(sin, &inp->inp_route,
			inp->inp_socket->so_options, inp->inp_moptions, &error,
			inp->inp_rdomain);
		if (ifaddr == NULL) {
			if (error == 0)
				error = EADDRNOTAVAIL;
			return error;
		}
	}
	if (in_pcbhashlookup(inp->inp_table, sin->sin_addr, sin->sin_port,
	    inp->inp_laddr.s_addr ? inp->inp_laddr : ifaddr->sin_addr,
	    inp->inp_lport, inp->inp_rdomain) != 0)
		return (EADDRINUSE);
	if (inp->inp_laddr.s_addr == INADDR_ANY) {
		if (inp->inp_lport == 0 &&
		    in_pcbbind(inp, NULL, curproc) == EADDRNOTAVAIL)
			return (EADDRNOTAVAIL);
		inp->inp_laddr = ifaddr->sin_addr;
	}
	inp->inp_faddr = sin->sin_addr;
	inp->inp_fport = sin->sin_port;
	in_pcbrehash(inp);
#ifdef IPSEC
	{
		int error; /* This is just ignored */

		/* Cause an IPsec SA to be established. */
		ipsp_spd_inp(NULL, AF_INET, 0, &error, IPSP_DIRECTION_OUT,
		    NULL, inp, NULL);
	}
#endif
	return (0);
}

void
in_pcbdisconnect(v)
	void *v;
{
	struct inpcb *inp = v;

	switch (sotopf(inp->inp_socket)) {
#ifdef INET6
	case PF_INET6:
		inp->inp_faddr6 = in6addr_any;
		break;
#endif
	case PF_INET:
		inp->inp_faddr.s_addr = INADDR_ANY;
		break;
	}

	inp->inp_fport = 0;
	in_pcbrehash(inp);
	if (inp->inp_socket->so_state & SS_NOFDREF)
		in_pcbdetach(inp);
}

void
in_pcbdetach(v)
	void *v;
{
	struct inpcb *inp = v;
	struct socket *so = inp->inp_socket;
	int s;

	so->so_pcb = 0;
	sofree(so);
	if (inp->inp_options)
		m_freem(inp->inp_options);
	if (inp->inp_route.ro_rt)
		rtfree(inp->inp_route.ro_rt);
#ifdef INET6
	if (inp->inp_flags & INP_IPV6) {
		ip6_freepcbopts(inp->inp_outputopts6);
		ip6_freemoptions(inp->inp_moptions6);
	} else
#endif
		ip_freemoptions(inp->inp_moptions);
#ifdef IPSEC
	/* IPsec cleanup here */
	s = spltdb();
	if (inp->inp_tdb_in)
		TAILQ_REMOVE(&inp->inp_tdb_in->tdb_inp_in,
			     inp, inp_tdb_in_next);
	if (inp->inp_tdb_out)
	        TAILQ_REMOVE(&inp->inp_tdb_out->tdb_inp_out, inp,
			     inp_tdb_out_next);
	if (inp->inp_ipsec_remotecred)
		ipsp_reffree(inp->inp_ipsec_remotecred);
	if (inp->inp_ipsec_remoteauth)
		ipsp_reffree(inp->inp_ipsec_remoteauth);
	if (inp->inp_ipo)
		ipsec_delete_policy(inp->inp_ipo);
	splx(s);
#endif
#if NPF > 0
	if (inp->inp_pf_sk)
		((struct pf_state_key *)inp->inp_pf_sk)->inp = NULL;
#endif
	s = splnet();
	LIST_REMOVE(inp, inp_lhash);
	LIST_REMOVE(inp, inp_hash);
	CIRCLEQ_REMOVE(&inp->inp_table->inpt_queue, inp, inp_queue);
	splx(s);
	pool_put(&inpcb_pool, inp);
}

void
in_setsockaddr(inp, nam)
	struct inpcb *inp;
	struct mbuf *nam;
{
	struct sockaddr_in *sin;

	nam->m_len = sizeof (*sin);
	sin = mtod(nam, struct sockaddr_in *);
	bzero((caddr_t)sin, sizeof (*sin));
	sin->sin_family = AF_INET;
	sin->sin_len = sizeof(*sin);
	sin->sin_port = inp->inp_lport;
	sin->sin_addr = inp->inp_laddr;
}

void
in_setpeeraddr(inp, nam)
	struct inpcb *inp;
	struct mbuf *nam;
{
	struct sockaddr_in *sin;

#ifdef INET6
	if (sotopf(inp->inp_socket) == PF_INET6) {
		in6_setpeeraddr(inp, nam);
		return;
	}
#endif /* INET6 */

	nam->m_len = sizeof (*sin);
	sin = mtod(nam, struct sockaddr_in *);
	bzero((caddr_t)sin, sizeof (*sin));
	sin->sin_family = AF_INET;
	sin->sin_len = sizeof(*sin);
	sin->sin_port = inp->inp_fport;
	sin->sin_addr = inp->inp_faddr;
}

/*
 * Pass some notification to all connections of a protocol
 * associated with address dst.  The "usual action" will be
 * taken, depending on the ctlinput cmd.  The caller must filter any
 * cmds that are uninteresting (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.
 */
void
in_pcbnotifyall(table, dst, errno, notify)
	struct inpcbtable *table;
	struct sockaddr *dst;
	int errno;
	void (*notify)(struct inpcb *, int);
{
	struct inpcb *inp, *oinp;
	struct in_addr faddr;

	splsoftassert(IPL_SOFTNET);

#ifdef INET6
	/*
	 * See in6_pcbnotify() for IPv6 codepath.  By the time this
	 * gets called, the addresses passed are either definitely IPv4 or
	 * IPv6; *_pcbnotify() never gets called with v4-mapped v6 addresses.
	 */
#endif /* INET6 */

	if (dst->sa_family != AF_INET)
		return;
	faddr = satosin(dst)->sin_addr;
	if (faddr.s_addr == INADDR_ANY)
		return;

	for (inp = CIRCLEQ_FIRST(&table->inpt_queue);
	    inp != CIRCLEQ_END(&table->inpt_queue);) {
#ifdef INET6
		if (inp->inp_flags & INP_IPV6) {
			inp = CIRCLEQ_NEXT(inp, inp_queue);
			continue;
		}
#endif
		if (inp->inp_faddr.s_addr != faddr.s_addr ||
		    inp->inp_socket == 0) {
			inp = CIRCLEQ_NEXT(inp, inp_queue);
			continue;
		}
		oinp = inp;
		inp = CIRCLEQ_NEXT(inp, inp_queue);
		if (notify)
			(*notify)(oinp, errno);
	}
}

/*
 * 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
in_losing(inp)
	struct inpcb *inp;
{
	struct rtentry *rt;
	struct rt_addrinfo info;

	if ((rt = inp->inp_route.ro_rt)) {
		inp->inp_route.ro_rt = 0;
		bzero((caddr_t)&info, sizeof(info));
		info.rti_flags = rt->rt_flags;
		info.rti_info[RTAX_DST] = &inp->inp_route.ro_dst;
		info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
		info.rti_info[RTAX_NETMASK] = rt_mask(rt);
		rt_missmsg(RTM_LOSING, &info, rt->rt_flags, rt->rt_ifp, 0,
		    inp->inp_rdomain);
		if (rt->rt_flags & RTF_DYNAMIC)
			(void)rtrequest1(RTM_DELETE, &info, rt->rt_priority,
				(struct rtentry **)0, inp->inp_rdomain);
		/*
		 * A new route can be allocated
		 * the next time output is attempted.
		 * rtfree() needs to be called in anycase because the inp
		 * is still holding a reference to rt.
		 */
		rtfree(rt);
	}
}

/*
 * After a routing change, flush old routing
 * and allocate a (hopefully) better one.
 */
void
in_rtchange(inp, errno)
	struct inpcb *inp;
	int errno;
{
	if (inp->inp_route.ro_rt) {
		rtfree(inp->inp_route.ro_rt);
		inp->inp_route.ro_rt = 0;
		/*
		 * A new route can be allocated the next time
		 * output is attempted.
		 */
	}
}

struct inpcb *
in_pcblookup(struct inpcbtable *table, void *faddrp, u_int fport_arg, void *laddrp, u_int lport_arg, int flags, u_int rdomain)
{
	struct inpcb *inp, *match = 0;
	int matchwild = 3, wildcard;
	u_int16_t fport = fport_arg, lport = lport_arg;
	struct in_addr faddr = *(struct in_addr *)faddrp;
	struct in_addr laddr = *(struct in_addr *)laddrp;

	for (inp = LIST_FIRST(INPCBLHASH(table, lport, rdomain)); inp;
	    inp = LIST_NEXT(inp, inp_lhash)) {
		if (inp->inp_rdomain != rdomain)
			continue;
		if (inp->inp_lport != lport)
			continue;
		wildcard = 0;
#ifdef INET6
		if (flags & INPLOOKUP_IPV6) {
			struct in6_addr *laddr6 = (struct in6_addr *)laddrp;
			struct in6_addr *faddr6 = (struct in6_addr *)faddrp;

			if (!(inp->inp_flags & INP_IPV6))
				continue;

			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_laddr6)) {
				if (IN6_IS_ADDR_UNSPECIFIED(laddr6))
					wildcard++;
				else if (!IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6, laddr6))
					continue;
			} else {
				if (!IN6_IS_ADDR_UNSPECIFIED(laddr6))
					wildcard++;
			}

			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6)) {
				if (IN6_IS_ADDR_UNSPECIFIED(faddr6))
					wildcard++;
				else if (!IN6_ARE_ADDR_EQUAL(&inp->inp_faddr6,
				    faddr6) || inp->inp_fport != fport)
					continue;
			} else {
				if (!IN6_IS_ADDR_UNSPECIFIED(faddr6))
					wildcard++;
			}
		} else
#endif /* INET6 */
		{
#ifdef INET6
		        if (inp->inp_flags & INP_IPV6)
			        continue;
#endif /* INET6 */

			if (inp->inp_faddr.s_addr != INADDR_ANY) {
				if (faddr.s_addr == INADDR_ANY)
					wildcard++;
				else if (inp->inp_faddr.s_addr != faddr.s_addr ||
				    inp->inp_fport != fport)
					continue;
			} else {
				if (faddr.s_addr != INADDR_ANY)
					wildcard++;
			}
			if (inp->inp_laddr.s_addr != INADDR_ANY) {
				if (laddr.s_addr == INADDR_ANY)
					wildcard++;
				else if (inp->inp_laddr.s_addr != laddr.s_addr)
					continue;
			} else {
				if (laddr.s_addr != INADDR_ANY)
					wildcard++;
			}
		}
		if ((!wildcard || (flags & INPLOOKUP_WILDCARD)) &&
		    wildcard < matchwild) {
			match = inp;
			if ((matchwild = wildcard) == 0)
				break;
		}
	}
	return (match);
}

struct rtentry *
in_pcbrtentry(inp)
	struct inpcb *inp;
{
	struct route *ro;

	ro = &inp->inp_route;

	/*
	 * No route yet, so try to acquire one.
	 */
	if (ro->ro_rt == NULL) {
#ifdef INET6
		bzero(ro, sizeof(struct route_in6));
#else
		bzero(ro, sizeof(struct route));
#endif

		switch(sotopf(inp->inp_socket)) {
#ifdef INET6
		case PF_INET6:
			if (IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6))
				break;
			ro->ro_dst.sa_family = AF_INET6;
			ro->ro_dst.sa_len = sizeof(struct sockaddr_in6);
			((struct sockaddr_in6 *) &ro->ro_dst)->sin6_addr =
			    inp->inp_faddr6;
			rtalloc_mpath(ro, &inp->inp_laddr6.s6_addr32[0], 0);
			break;
#endif /* INET6 */
		case PF_INET:
			if (inp->inp_faddr.s_addr == INADDR_ANY)
				break;
			ro->ro_dst.sa_family = AF_INET;
			ro->ro_dst.sa_len = sizeof(ro->ro_dst);
			satosin(&ro->ro_dst)->sin_addr = inp->inp_faddr;
			rtalloc_mpath(ro, &inp->inp_laddr.s_addr, 0);
			break;
		}
	}
	return (ro->ro_rt);
}

struct sockaddr_in *
in_selectsrc(struct sockaddr_in *sin, struct route *ro, int soopts,
    struct ip_moptions *mopts, int *errorp, u_int rdomain)
{
	struct sockaddr_in *sin2;
	struct in_ifaddr *ia;

	ia = (struct in_ifaddr *)0;
	/*
	 * If route is known or can be allocated now,
	 * our src addr is taken from the i/f, else punt.
	 */
	if (ro->ro_rt &&
	    (satosin(&ro->ro_dst)->sin_addr.s_addr !=
		sin->sin_addr.s_addr ||
	    soopts & SO_DONTROUTE)) {
		RTFREE(ro->ro_rt);
		ro->ro_rt = (struct rtentry *)0;
	}
	if ((soopts & SO_DONTROUTE) == 0 && /*XXX*/
	    (ro->ro_rt == (struct rtentry *)0 ||
	    ro->ro_rt->rt_ifp == (struct ifnet *)0)) {
		/* No route yet, so try to acquire one */
		ro->ro_dst.sa_family = AF_INET;
		ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
		satosin(&ro->ro_dst)->sin_addr = sin->sin_addr;
		rtalloc_mpath(ro, NULL, rdomain);

		/*
		 * It is important to bzero out the rest of the
		 * struct sockaddr_in when mixing v6 & v4!
		 */
		sin2 = (struct sockaddr_in *)&ro->ro_dst;
		bzero(sin2->sin_zero, sizeof(sin2->sin_zero));
	}
	/*
	 * If we found a route, use the address
	 * corresponding to the outgoing interface
	 * unless it is the loopback (in case a route
	 * to our address on another net goes to loopback).
	 */
	if (ro->ro_rt && !(ro->ro_rt->rt_ifp->if_flags & IFF_LOOPBACK))
		ia = ifatoia(ro->ro_rt->rt_ifa);
	if (ia == 0) {
		u_int16_t fport = sin->sin_port;

		sin->sin_port = 0;
		ia = ifatoia(ifa_ifwithdstaddr(sintosa(sin), rdomain));
		if (ia == 0)
			ia = ifatoia(ifa_ifwithnet(sintosa(sin), rdomain));
		sin->sin_port = fport;
		if (ia == 0)
			ia = TAILQ_FIRST(&in_ifaddr);
		if (ia == 0) {
			*errorp = EADDRNOTAVAIL;
			return NULL;
		}
	}
	/*
	 * If the destination address is multicast and an outgoing
	 * interface has been set as a multicast option, use the
	 * address of that interface as our source address.
	 */
	if (IN_MULTICAST(sin->sin_addr.s_addr) && mopts != NULL) {
		struct ip_moptions *imo;
		struct ifnet *ifp;

		imo = mopts;
		if (imo->imo_multicast_ifp != NULL) {
			ifp = imo->imo_multicast_ifp;
			TAILQ_FOREACH(ia, &in_ifaddr, ia_list)
				if (ia->ia_ifp == ifp)
					break;
			if (ia == 0) {
				*errorp = EADDRNOTAVAIL;
				return NULL;
			}
		}
	}
	return satosin(&ia->ia_addr);
}

void
in_pcbrehash(inp)
	struct inpcb *inp;
{
	struct inpcbtable *table = inp->inp_table;
	int s;

	s = splnet();
	LIST_REMOVE(inp, inp_lhash);
	LIST_INSERT_HEAD(INPCBLHASH(table, inp->inp_lport, inp->inp_rdomain),
	    inp, inp_lhash);
	LIST_REMOVE(inp, inp_hash);
#ifdef INET6
	if (inp->inp_flags & INP_IPV6) {
		LIST_INSERT_HEAD(IN6PCBHASH(table, &inp->inp_faddr6,
		    inp->inp_fport, &inp->inp_laddr6, inp->inp_lport),
		    inp, inp_hash);
	} else {
#endif /* INET6 */
		LIST_INSERT_HEAD(INPCBHASH(table, &inp->inp_faddr,
		    inp->inp_fport, &inp->inp_laddr, inp->inp_lport,
		    inp->inp_rdomain), inp, inp_hash);
#ifdef INET6
	}
#endif /* INET6 */
	splx(s);
}

#ifdef DIAGNOSTIC
int	in_pcbnotifymiss = 0;
#endif

/*
 * The in(6)_pcbhashlookup functions are used to locate connected sockets
 * quickly:
 * 		faddr.fport <-> laddr.lport
 * No wildcard matching is done so that listening sockets are not found.
 * If the functions return NULL in(6)_pcblookup_listen can be used to
 * find a listening/bound socket that may accept the connection.
 * After those two lookups no other are necessary.
 */
struct inpcb *
in_pcbhashlookup(struct inpcbtable *table, struct in_addr faddr,
    u_int fport_arg, struct in_addr laddr, u_int lport_arg, u_int rdomain)
{
	struct inpcbhead *head;
	struct inpcb *inp;
	u_int16_t fport = fport_arg, lport = lport_arg;

	head = INPCBHASH(table, &faddr, fport, &laddr, lport, rdomain);
	LIST_FOREACH(inp, head, inp_hash) {
#ifdef INET6
		if (inp->inp_flags & INP_IPV6)
			continue;	/*XXX*/
#endif
		if (inp->inp_faddr.s_addr == faddr.s_addr &&
		    inp->inp_fport == fport &&
		    inp->inp_lport == lport &&
		    inp->inp_laddr.s_addr == laddr.s_addr &&
		    inp->inp_rdomain == rdomain) {
			/*
			 * Move this PCB to the head of hash chain so that
			 * repeated accesses are quicker.  This is analogous to
			 * the historic single-entry PCB cache.
			 */
			if (inp != LIST_FIRST(head)) {
				LIST_REMOVE(inp, inp_hash);
				LIST_INSERT_HEAD(head, inp, inp_hash);
			}
			break;
		}
	}
#ifdef DIAGNOSTIC
	if (inp == NULL && in_pcbnotifymiss) {
		printf("in_pcbhashlookup: faddr=%08x fport=%d laddr=%08x lport=%d rdom=%d\n",
		    ntohl(faddr.s_addr), ntohs(fport),
		    ntohl(laddr.s_addr), ntohs(lport), rdomain);
	}
#endif
	return (inp);
}

#ifdef INET6
struct inpcb *
in6_pcbhashlookup(struct inpcbtable *table, struct in6_addr *faddr,
    u_int fport_arg, struct in6_addr *laddr, u_int lport_arg)
{
	struct inpcbhead *head;
	struct inpcb *inp;
	u_int16_t fport = fport_arg, lport = lport_arg;

	head = IN6PCBHASH(table, faddr, fport, laddr, lport);
	LIST_FOREACH(inp, head, inp_hash) {
		if (!(inp->inp_flags & INP_IPV6))
			continue;
		if (IN6_ARE_ADDR_EQUAL(&inp->inp_faddr6, faddr) &&
		    inp->inp_fport == fport && inp->inp_lport == lport &&
		    IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6, laddr)) {
			/*
			 * Move this PCB to the head of hash chain so that
			 * repeated accesses are quicker.  This is analogous to
			 * the historic single-entry PCB cache.
			 */
			if (inp != LIST_FIRST(head)) {
				LIST_REMOVE(inp, inp_hash);
				LIST_INSERT_HEAD(head, inp, inp_hash);
			}
			break;
		}
	}
#ifdef DIAGNOSTIC
	if (inp == NULL && in_pcbnotifymiss) {
		printf("in6_pcbhashlookup: faddr=");
		printf(" fport=%d laddr=", ntohs(fport));
		printf(" lport=%d\n", ntohs(lport));
	}
#endif
	return (inp);
}
#endif /* INET6 */

/*
 * The in(6)_pcblookup_listen functions are used to locate listening
 * sockets quickly.  This are sockets with unspecified foreign address
 * and port:
 *		*.*     <-> laddr.lport
 *		*.*     <->     *.lport
 */
struct inpcb *
in_pcblookup_listen(struct inpcbtable *table, struct in_addr laddr,
    u_int lport_arg, int reverse, struct mbuf *m, u_int rdomain)
{
	struct inpcbhead *head;
	struct in_addr *key1, *key2;
	struct inpcb *inp;
	u_int16_t lport = lport_arg;

#if NPF > 0
	if (m && m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) {
		struct pf_divert *divert;
		/* XXX rdomain */
		if ((divert = pf_find_divert(m)) == NULL)
			return (NULL);
		key1 = key2 = &divert->addr.ipv4;
		lport = divert->port;
	} else
#endif
	if (reverse) {
		key1 = &zeroin_addr;
		key2 = &laddr;
	} else {
		key1 = &laddr;
		key2 = &zeroin_addr;
	}

	head = INPCBHASH(table, &zeroin_addr, 0, key1, lport, rdomain);
	LIST_FOREACH(inp, head, inp_hash) {
#ifdef INET6
		if (inp->inp_flags & INP_IPV6)
			continue;	/*XXX*/
#endif
		if (inp->inp_lport == lport && inp->inp_fport == 0 &&
		    inp->inp_laddr.s_addr == key1->s_addr &&
		    inp->inp_faddr.s_addr == INADDR_ANY &&
		    inp->inp_rdomain == rdomain)
			break;
	}
	if (inp == NULL && key1->s_addr != key2->s_addr) {
		head = INPCBHASH(table, &zeroin_addr, 0, key2, lport, rdomain);
		LIST_FOREACH(inp, head, inp_hash) {
#ifdef INET6
			if (inp->inp_flags & INP_IPV6)
				continue;	/*XXX*/
#endif
			if (inp->inp_lport == lport && inp->inp_fport == 0 &&
			    inp->inp_laddr.s_addr == key2->s_addr &&
			    inp->inp_faddr.s_addr == INADDR_ANY &&
			    inp->inp_rdomain == rdomain)
				break;
		}
	}
#ifdef DIAGNOSTIC
	if (inp == NULL && in_pcbnotifymiss) {
		printf("in_pcblookup_listen: laddr=%08x lport=%d\n",
		    ntohl(laddr.s_addr), ntohs(lport));
	}
#endif
	/*
	 * Move this PCB to the head of hash chain so that
	 * repeated accesses are quicker.  This is analogous to
	 * the historic single-entry PCB cache.
	 */
	if (inp != NULL && inp != LIST_FIRST(head)) {
		LIST_REMOVE(inp, inp_hash);
		LIST_INSERT_HEAD(head, inp, inp_hash);
	}
	return (inp);
}

#ifdef INET6
struct inpcb *
in6_pcblookup_listen(struct inpcbtable *table, struct in6_addr *laddr,
    u_int lport_arg, int reverse, struct mbuf *m)
{
	struct inpcbhead *head;
	struct in6_addr *key1, *key2;
	struct inpcb *inp;
	u_int16_t lport = lport_arg;

#if NPF > 0
	if (m && m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) {
		struct pf_divert *divert;

		if ((divert = pf_find_divert(m)) == NULL)
			return (NULL);
		key1 = key2 = &divert->addr.ipv6;
		lport = divert->port;
	} else
#endif
	if (reverse) {
		key1 = &zeroin6_addr;
		key2 = laddr;
	} else {
		key1 = laddr;
		key2 = &zeroin6_addr;
	}

	head = IN6PCBHASH(table, &zeroin6_addr, 0, key1, lport);
	LIST_FOREACH(inp, head, inp_hash) {
		if (!(inp->inp_flags & INP_IPV6))
			continue;
		if (inp->inp_lport == lport && inp->inp_fport == 0 &&
		    IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6, key1) &&
		    IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6))
			break;
	}
	if (inp == NULL && ! IN6_ARE_ADDR_EQUAL(key1, key2)) {
		head = IN6PCBHASH(table, &zeroin6_addr, 0, key2, lport);
		LIST_FOREACH(inp, head, inp_hash) {
			if (!(inp->inp_flags & INP_IPV6))
				continue;
			if (inp->inp_lport == lport && inp->inp_fport == 0 &&
		    	    IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6, key2) &&
			    IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6))
				break;
		}
	}
#ifdef DIAGNOSTIC
	if (inp == NULL && in_pcbnotifymiss) {
		printf("in6_pcblookup_listen: laddr= lport=%d\n",
		    ntohs(lport));
	}
#endif
	/*
	 * Move this PCB to the head of hash chain so that
	 * repeated accesses are quicker.  This is analogous to
	 * the historic single-entry PCB cache.
	 */
	if (inp != NULL && inp != LIST_FIRST(head)) {
		LIST_REMOVE(inp, inp_hash);
		LIST_INSERT_HEAD(head, inp, inp_hash);
	}
	return (inp);
}
#endif /* INET6 */