[apple/xnu.git] / bsd / netinet / in_pcb.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)in_pcb.c    8.4 (Berkeley) 5/24/95
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#if INET6 
#include <sys/domain.h>
#endif 
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>

#include <machine/limits.h>

#if ISFB31
#include <vm/vm_zone.h>
#else
#include <kern/zalloc.h>
#endif

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

#include <netinet/in.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#if INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#endif /* INET6 */

#include "faith.h"

#if IPSEC
#include <netinet6/ipsec.h>
#include <netkey/key.h>
#include <netkey/key_debug.h>
#endif /* IPSEC */

#include <sys/kdebug.h>


#define DBG_FNC_PCB_LOOKUP      NETDBG_CODE(DBG_NETTCP, (6 << 8))
#define DBG_FNC_PCB_HLOOKUP     NETDBG_CODE(DBG_NETTCP, ((6 << 8) | 1))

struct  in_addr zeroin_addr;

void    in_pcbremlists __P((struct inpcb *));
static void     in_rtchange __P((struct inpcb *, int));


/*
 * These configure the range of local port addresses assigned to
 * "unspecified" outgoing connections/packets/whatever.
 */
int ipport_lowfirstauto  = IPPORT_RESERVED - 1; /* 1023 */
int ipport_lowlastauto = IPPORT_RESERVEDSTART;  /* 600 */
int ipport_firstauto = IPPORT_HIFIRSTAUTO;      /* 49152 */
int ipport_lastauto  = IPPORT_HILASTAUTO;       /* 65535 */
int ipport_hifirstauto = IPPORT_HIFIRSTAUTO;    /* 49152 */
int ipport_hilastauto  = IPPORT_HILASTAUTO;     /* 65535 */

#define RANGECHK(var, min, max) \
        if ((var) < (min)) { (var) = (min); } \
        else if ((var) > (max)) { (var) = (max); }


static int
sysctl_net_ipport_check SYSCTL_HANDLER_ARGS
{
        int error = sysctl_handle_int(oidp,
                oidp->oid_arg1, oidp->oid_arg2, req);
        if (!error) {
                RANGECHK(ipport_lowfirstauto, 1, IPPORT_RESERVED - 1);
                RANGECHK(ipport_lowlastauto, 1, IPPORT_RESERVED - 1);
                RANGECHK(ipport_firstauto, IPPORT_RESERVED, USHRT_MAX);
                RANGECHK(ipport_lastauto, IPPORT_RESERVED, USHRT_MAX);
                RANGECHK(ipport_hifirstauto, IPPORT_RESERVED, USHRT_MAX);
                RANGECHK(ipport_hilastauto, IPPORT_RESERVED, USHRT_MAX);
        }
        return error;
}

#undef RANGECHK

SYSCTL_NODE(_net_inet_ip, IPPROTO_IP, portrange, CTLFLAG_RW, 0, "IP Ports");

SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, lowfirst, CTLTYPE_INT|CTLFLAG_RW,
           &ipport_lowfirstauto, 0, &sysctl_net_ipport_check, "I", "");
SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, lowlast, CTLTYPE_INT|CTLFLAG_RW,
           &ipport_lowlastauto, 0, &sysctl_net_ipport_check, "I", "");
SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, first, CTLTYPE_INT|CTLFLAG_RW,
           &ipport_firstauto, 0, &sysctl_net_ipport_check, "I", "");
SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, last, CTLTYPE_INT|CTLFLAG_RW,
           &ipport_lastauto, 0, &sysctl_net_ipport_check, "I", "");
SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, hifirst, CTLTYPE_INT|CTLFLAG_RW,
           &ipport_hifirstauto, 0, &sysctl_net_ipport_check, "I", "");
SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, hilast, CTLTYPE_INT|CTLFLAG_RW,
           &ipport_hilastauto, 0, &sysctl_net_ipport_check, "I", "");

/*
 * in_pcb.c: manage the Protocol Control Blocks.
 *
 * NOTE: It is assumed that most of these functions will be called at
 * splnet(). XXX - There are, unfortunately, a few exceptions to this
 * rule that should be fixed.
 */

/*
 * Allocate a PCB and associate it with the socket.
 */
int
in_pcballoc(so, pcbinfo, p)
        struct socket *so;
        struct inpcbinfo *pcbinfo;
        struct proc *p;
{
        register struct inpcb *inp;
        caddr_t               temp;

        if (so->cached_in_sock_layer == 0) {
#if TEMPDEBUG
            printf("PCBALLOC calling zalloc for socket %x\n", so);
#endif
            inp = (struct inpcb *) zalloc(pcbinfo->ipi_zone);
            if (inp == NULL)
                 return (ENOBUFS);
            bzero((caddr_t)inp, sizeof(*inp));
        }
        else {
#if TEMPDEBUG
            printf("PCBALLOC reusing PCB for socket %x\n", so);
#endif
            inp = (struct inpcb *) so->so_saved_pcb;
            temp = inp->inp_saved_ppcb;
            bzero((caddr_t) inp, sizeof(*inp));
            inp->inp_saved_ppcb = temp;
        }

        inp->inp_gencnt = ++pcbinfo->ipi_gencnt;
        inp->inp_pcbinfo = pcbinfo;
        inp->inp_socket = so;
        LIST_INSERT_HEAD(pcbinfo->listhead, inp, inp_list);
        pcbinfo->ipi_count++;
        so->so_pcb = (caddr_t)inp;
        return (0);
}

int
in_pcbbind(inp, nam, p)
        register struct inpcb *inp;
        struct sockaddr *nam;
        struct proc *p;
{
        register struct socket *so = inp->inp_socket;
        u_short *lastport;
        struct sockaddr_in *sin;
        struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
        u_short lport = 0;
        int wild = 0, reuseport = (so->so_options & SO_REUSEPORT);
        int error;

        if (TAILQ_EMPTY(&in_ifaddrhead)) /* XXX broken! */
                return (EADDRNOTAVAIL);
        if (inp->inp_lport || inp->inp_laddr.s_addr != INADDR_ANY)
                return (EINVAL);
        if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0)
                wild = 1;
        if (nam) {
                sin = (struct sockaddr_in *)nam;
                if (nam->sa_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(ntohl(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 (ifa_ifwithaddr((struct sockaddr *)sin) == 0)
                                return (EADDRNOTAVAIL);
                }
                if (lport) {
                        struct inpcb *t;

                        /* GROSS */
                        if (ntohs(lport) < IPPORT_RESERVED && p &&
                            suser(p->p_ucred, &p->p_acflag))
                                return (EACCES);
                        if (so->so_uid &&
                            !IN_MULTICAST(ntohl(sin->sin_addr.s_addr))) {
                                t = in_pcblookup_local(inp->inp_pcbinfo,
                                    sin->sin_addr, lport, INPLOOKUP_WILDCARD);
                                if (t &&
                                    (ntohl(sin->sin_addr.s_addr) != INADDR_ANY ||
                                     ntohl(t->inp_laddr.s_addr) != INADDR_ANY ||
                                     (t->inp_socket->so_options &
                                         SO_REUSEPORT) == 0) &&
                                     (so->so_uid != t->inp_socket->so_uid)) {
#if INET6
                                        if (ip6_mapped_addr_on == 0 ||
                                            ntohl(sin->sin_addr.s_addr) !=
                                            INADDR_ANY ||
                                            ntohl(t->inp_laddr.s_addr) !=
                                            INADDR_ANY ||
                                            INP_SOCKAF(so) ==
                                            INP_SOCKAF(t->inp_socket))
#endif
                                        return (EADDRINUSE);
                                }
                        }
                        t = in_pcblookup_local(pcbinfo, sin->sin_addr,
                            lport, wild);
                        if (t &&
                            (reuseport & t->inp_socket->so_options) == 0) {
#if INET6
                                if (ip6_mapped_addr_on == 0 ||
                                    ntohl(sin->sin_addr.s_addr) !=
                                    INADDR_ANY ||
                                    ntohl(t->inp_laddr.s_addr) !=
                                    INADDR_ANY ||
                                    INP_SOCKAF(so) ==
                                    INP_SOCKAF(t->inp_socket))
#endif
                                return (EADDRINUSE);
                        }
                }
                inp->inp_laddr = sin->sin_addr;
        }
        if (lport == 0) {
                u_short first, last;
                int count;

                inp->inp_flags |= INP_ANONPORT;

                if (inp->inp_flags & INP_HIGHPORT) {
                        first = ipport_hifirstauto;     /* sysctl */
                        last  = ipport_hilastauto;
                        lastport = &pcbinfo->lasthi;
                } else if (inp->inp_flags & INP_LOWPORT) {
                        if (p && (error = suser(p->p_ucred, &p->p_acflag)))
                                return error;
                        first = ipport_lowfirstauto;    /* 1023 */
                        last  = ipport_lowlastauto;     /* 600 */
                        lastport = &pcbinfo->lastlow;
                } else {
                        first = ipport_firstauto;       /* sysctl */
                        last  = ipport_lastauto;
                        lastport = &pcbinfo->lastport;
                }
                /*
                 * 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;

                        do {
                                if (count-- < 0) {      /* completely used? */
                                        /*
                                         * Undo any address bind that may have
                                         * occurred above.
                                         */
                                        inp->inp_laddr.s_addr = INADDR_ANY;
                                        return (EAGAIN);
                                }
                                --*lastport;
                                if (*lastport > first || *lastport < last)
                                        *lastport = first;
                                lport = htons(*lastport);
                        } while (in_pcblookup_local(pcbinfo,
                                 inp->inp_laddr, lport, wild));
                } else {
                        /*
                         * counting up
                         */
                        count = last - first;

                        do {
                                if (count-- < 0) {      /* completely used? */
                                        /*
                                         * Undo any address bind that may have
                                         * occurred above.
                                         */
                                        inp->inp_laddr.s_addr = INADDR_ANY;
                                        return (EAGAIN);
                                }
                                ++*lastport;
                                if (*lastport < first || *lastport > last)
                                        *lastport = first;
                                lport = htons(*lastport);
                        } while (in_pcblookup_local(pcbinfo,
                                 inp->inp_laddr, lport, wild));
                }
        }
        inp->inp_lport = lport;
        if (in_pcbinshash(inp) != 0) {
                inp->inp_laddr.s_addr = INADDR_ANY;
                inp->inp_lport = 0;
                return (EAGAIN);
        }
        return (0);
}

/*
 *   Transform old in_pcbconnect() into an inner subroutine for new
 *   in_pcbconnect(): Do some validity-checking on the remote
 *   address (in mbuf 'nam') and then determine local host address
 *   (i.e., which interface) to use to access that remote host.
 *
 *   This preserves definition of in_pcbconnect(), while supporting a
 *   slightly different version for T/TCP.  (This is more than
 *   a bit of a kludge, but cleaning up the internal interfaces would
 *   have forced minor changes in every protocol).
 */

int
in_pcbladdr(inp, nam, plocal_sin)
        register struct inpcb *inp;
        struct sockaddr *nam;
        struct sockaddr_in **plocal_sin;
{
        struct in_ifaddr *ia;
        register struct sockaddr_in *sin = (struct sockaddr_in *)nam;

        if (nam->sa_len != sizeof (*sin))
                return (EINVAL);
        if (sin->sin_family != AF_INET)
                return (EAFNOSUPPORT);
        if (sin->sin_port == 0)
                return (EADDRNOTAVAIL);
        if (!TAILQ_EMPTY(&in_ifaddrhead)) {
                /*
                 * 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.
                 */
#define satosin(sa)     ((struct sockaddr_in *)(sa))
#define sintosa(sin)    ((struct sockaddr *)(sin))
#define ifatoia(ifa)    ((struct in_ifaddr *)(ifa))
                if (sin->sin_addr.s_addr == INADDR_ANY)
                    sin->sin_addr = IA_SIN(in_ifaddrhead.tqh_first)->sin_addr;
                else if (sin->sin_addr.s_addr == (u_long)INADDR_BROADCAST &&
                  (in_ifaddrhead.tqh_first->ia_ifp->if_flags & IFF_BROADCAST))
                    sin->sin_addr = satosin(&in_ifaddrhead.tqh_first->ia_broadaddr)->sin_addr;
        }
        if (inp->inp_laddr.s_addr == INADDR_ANY) {
                register struct route *ro;

                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.
                 */
                ro = &inp->inp_route;
                if (ro->ro_rt &&
                    (satosin(&ro->ro_dst)->sin_addr.s_addr !=
                        sin->sin_addr.s_addr ||
                    inp->inp_socket->so_options & SO_DONTROUTE)) {
                        RTFREE(ro->ro_rt);
                        ro->ro_rt = (struct rtentry *)0;
                }
                if ((inp->inp_socket->so_options & 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);
                        ((struct sockaddr_in *) &ro->ro_dst)->sin_addr =
                                sin->sin_addr;
                        rtalloc(ro);
                }
                /*
                 * 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_short fport = sin->sin_port;

                        sin->sin_port = 0;
                        ia = ifatoia(ifa_ifwithdstaddr(sintosa(sin)));
                        if (ia == 0)
                                ia = ifatoia(ifa_ifwithnet(sintosa(sin)));
                        sin->sin_port = fport;
                        if (ia == 0)
                                ia = in_ifaddrhead.tqh_first;
                        if (ia == 0)
                                return (EADDRNOTAVAIL);
                }
                /*
                 * 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(ntohl(sin->sin_addr.s_addr)) &&
                    inp->inp_moptions != NULL) {
                        struct ip_moptions *imo;
                        struct ifnet *ifp;

                        imo = inp->inp_moptions;
                        if (imo->imo_multicast_ifp != NULL) {
                                ifp = imo->imo_multicast_ifp;
                                for (ia = in_ifaddrhead.tqh_first; ia; 
                                     ia = ia->ia_link.tqe_next)
                                        if (ia->ia_ifp == ifp)
                                                break;
                                if (ia == 0)
                                        return (EADDRNOTAVAIL);
                        }
                }
        /*
         * Don't do pcblookup call here; return interface in plocal_sin
         * and exit to caller, that will do the lookup.
         */
                *plocal_sin = &ia->ia_addr;

        }
        return(0);
}

/*
 * Outer subroutine:
 * 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(inp, nam, p)
        register struct inpcb *inp;
        struct sockaddr *nam;
        struct proc *p;
{
        struct sockaddr_in *ifaddr;
        register struct sockaddr_in *sin = (struct sockaddr_in *)nam;
        int error;

        /*
         *   Call inner routine, to assign local interface address.
         */
        if ((error = in_pcbladdr(inp, nam, &ifaddr)) != 0)
                return(error);

        if (in_pcblookup_hash(inp->inp_pcbinfo, sin->sin_addr, sin->sin_port,
            inp->inp_laddr.s_addr ? inp->inp_laddr : ifaddr->sin_addr,
            inp->inp_lport, 0, NULL) != NULL) {
                return (EADDRINUSE);
        }
        if (inp->inp_laddr.s_addr == INADDR_ANY) {
                if (inp->inp_lport == 0)
                        (void)in_pcbbind(inp, (struct sockaddr *)0, p);
                inp->inp_laddr = ifaddr->sin_addr;
        }
        inp->inp_faddr = sin->sin_addr;
        inp->inp_fport = sin->sin_port;
        in_pcbrehash(inp);
        return (0);
}

void
in_pcbdisconnect(inp)
        struct inpcb *inp;
{

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

void
in_pcbdetach(inp)
        struct inpcb *inp;
{
        struct socket *so = inp->inp_socket;
        struct inpcbinfo *ipi = inp->inp_pcbinfo;

#if IPSEC
        ipsec4_delete_pcbpolicy(inp);
#endif /*IPSEC*/
        inp->inp_gencnt = ++ipi->ipi_gencnt;
        in_pcbremlists(inp);

#if TEMPDEBUG
        if (so->cached_in_sock_layer)
            printf("PCB_DETACH for cached socket %x\n", so);
        else
            printf("PCB_DETACH for allocated socket %x\n", so);
#endif

        so->so_pcb = 0;

        if (inp->inp_options)
                (void)m_free(inp->inp_options);
        if (inp->inp_route.ro_rt)
                rtfree(inp->inp_route.ro_rt);
        ip_freemoptions(inp->inp_moptions);
        if (so->cached_in_sock_layer)
             so->so_saved_pcb = (caddr_t) inp;
        else
             zfree(ipi->ipi_zone, (vm_offset_t) inp);

        sofree(so);
}

/*
 * The calling convention of in_setsockaddr() and in_setpeeraddr() was
 * modified to match the pru_sockaddr() and pru_peeraddr() entry points
 * in struct pr_usrreqs, so that protocols can just reference then directly
 * without the need for a wrapper function.  The socket must have a valid
 * (i.e., non-nil) PCB, but it should be impossible to get an invalid one
 * except through a kernel programming error, so it is acceptable to panic
 * (or in this case trap) if the PCB is invalid.  (Actually, we don't trap
 * because there actually /is/ a programming error somewhere... XXX)
 */
int
in_setsockaddr(so, nam)
        struct socket *so;
        struct sockaddr **nam;
{
        int s;
        register struct inpcb *inp;
        register struct sockaddr_in *sin;

        /*
         * Do the malloc first in case it blocks.
         */
        MALLOC(sin, struct sockaddr_in *, sizeof *sin, M_SONAME, M_WAITOK);
        if (sin == NULL)
                return ENOBUFS;
        bzero(sin, sizeof *sin);
        sin->sin_family = AF_INET;
        sin->sin_len = sizeof(*sin);

        s = splnet();
        inp = sotoinpcb(so);
        if (!inp) {
                splx(s);
                FREE(sin, M_SONAME);
                return EINVAL;
        }
        sin->sin_port = inp->inp_lport;
        sin->sin_addr = inp->inp_laddr;
        splx(s);

        *nam = (struct sockaddr *)sin;
        return 0;
}

int
in_setpeeraddr(so, nam)
        struct socket *so;
        struct sockaddr **nam;
{
        int s;
        struct inpcb *inp;
        register struct sockaddr_in *sin;

        /*
         * Do the malloc first in case it blocks.
         */
        MALLOC(sin, struct sockaddr_in *, sizeof *sin, M_SONAME, M_WAITOK);
        if (sin == NULL)
                return ENOBUFS;
        bzero((caddr_t)sin, sizeof (*sin));
        sin->sin_family = AF_INET;
        sin->sin_len = sizeof(*sin);

        s = splnet();
        inp = sotoinpcb(so);
        if (!inp) {
                splx(s);
                FREE(sin, M_SONAME);
                return EINVAL;
        }
        sin->sin_port = inp->inp_fport;
        sin->sin_addr = inp->inp_faddr;
        splx(s);

        *nam = (struct sockaddr *)sin;
        return 0;
}

/*
 * Pass some notification to all connections of a protocol
 * associated with address dst.  The local address and/or port numbers
 * may be specified to limit the search.  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.
 */
void
in_pcbnotify(head, dst, fport_arg, laddr, lport_arg, cmd, notify)
        struct inpcbhead *head;
        struct sockaddr *dst;
        u_int fport_arg, lport_arg;
        struct in_addr laddr;
        int cmd;
        void (*notify) __P((struct inpcb *, int));
{
        register struct inpcb *inp, *oinp;
        struct in_addr faddr;
        u_short fport = fport_arg, lport = lport_arg;
        int errno, s;

        if ((unsigned)cmd > PRC_NCMDS || dst->sa_family != AF_INET)
                return;
        faddr = ((struct sockaddr_in *)dst)->sin_addr;
        if (faddr.s_addr == INADDR_ANY)
                return;

        /*
         * Redirects go to all references to the destination,
         * and use in_rtchange to invalidate the route cache.
         * Dead host indications: notify all references to the destination.
         * Otherwise, if we have knowledge of the local port and address,
         * deliver only to that socket.
         */
        if (PRC_IS_REDIRECT(cmd) || cmd == PRC_HOSTDEAD) {
                fport = 0;
                lport = 0;
                laddr.s_addr = 0;
                if (cmd != PRC_HOSTDEAD)
                        notify = in_rtchange;
        }
        errno = inetctlerrmap[cmd];
        s = splnet();
        for (inp = head->lh_first; inp != NULL;) {
                if ((inp->inp_vflag & INP_IPV4) == NULL) {
                        inp = LIST_NEXT(inp, inp_list);
                        continue;
                }
                if (inp->inp_faddr.s_addr != faddr.s_addr ||
                    inp->inp_socket == 0 ||
                    (lport && inp->inp_lport != lport) ||
                    (laddr.s_addr && inp->inp_laddr.s_addr != laddr.s_addr) ||
                    (fport && inp->inp_fport != fport)) {
                        inp = LIST_NEXT(inp, inp_list);
                        continue;
                }
                oinp = inp;
                inp = LIST_NEXT(inp, inp_list);
                if (notify)
                        (*notify)(oinp, errno);
        }
        splx(s);
}

/*
 * 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;
{
        register 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_info[RTAX_DST] =
                        (struct sockaddr *)&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, 0);
                if (rt->rt_flags & RTF_DYNAMIC)
                        (void) rtrequest(RTM_DELETE, rt_key(rt),
                                rt->rt_gateway, rt_mask(rt), rt->rt_flags,
                                (struct rtentry **)0);
                else
                /*
                 * A new route can be allocated
                 * the next time output is attempted.
                 */
                        rtfree(rt);
        }
}

/*
 * After a routing change, flush old routing
 * and allocate a (hopefully) better one.
 */
static void
in_rtchange(inp, errno)
        register 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.
                 */
        }
}

/*
 * Lookup a PCB based on the local address and port.
 */
struct inpcb *
in_pcblookup_local(pcbinfo, laddr, lport_arg, wild_okay)
        struct inpcbinfo *pcbinfo;
        struct in_addr laddr;
        u_int lport_arg;
        int wild_okay;
{
        register struct inpcb *inp;
        int matchwild = 3, wildcard;
        u_short lport = lport_arg;

        KERNEL_DEBUG(DBG_FNC_PCB_LOOKUP | DBG_FUNC_START, 0,0,0,0,0);

        if (!wild_okay) {
                struct inpcbhead *head;
                /*
                 * Look for an unconnected (wildcard foreign addr) PCB that
                 * matches the local address and port we're looking for.
                 */
                head = &pcbinfo->hashbase[INP_PCBHASH(INADDR_ANY, lport, 0, pcbinfo->hashmask)];
                for (inp = head->lh_first; inp != NULL; inp = inp->inp_hash.le_next) {
                        if ((inp->inp_vflag & INP_IPV4) == NULL)
                                continue;
                        if (inp->inp_faddr.s_addr == INADDR_ANY &&
                            inp->inp_laddr.s_addr == laddr.s_addr &&
                            inp->inp_lport == lport) {
                                /*
                                 * Found.
                                 */
                                return (inp);
                        }
                }
                /*
                 * Not found.
                 */
                KERNEL_DEBUG(DBG_FNC_PCB_LOOKUP | DBG_FUNC_END, 0,0,0,0,0);
                return (NULL);
        } else {
                struct inpcbporthead *porthash;
                struct inpcbport *phd;
                struct inpcb *match = NULL;
                /*
                 * Best fit PCB lookup.
                 *
                 * First see if this local port is in use by looking on the
                 * port hash list.
                 */
                porthash = &pcbinfo->porthashbase[INP_PCBPORTHASH(lport,
                    pcbinfo->porthashmask)];
                for (phd = porthash->lh_first; phd != NULL; phd = phd->phd_hash.le_next) {
                        if (phd->phd_port == lport)
                                break;
                }
                if (phd != NULL) {
                        /*
                         * Port is in use by one or more PCBs. Look for best
                         * fit.
                         */
                        for (inp = phd->phd_pcblist.lh_first; inp != NULL;
                            inp = inp->inp_portlist.le_next) {
                                wildcard = 0;
                                if ((inp->inp_vflag & INP_IPV4) == NULL)
                                        continue;
                                if (inp->inp_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 < matchwild) {
                                        match = inp;
                                        matchwild = wildcard;
                                        if (matchwild == 0) {
                                                break;
                                        }
                                }
                        }
                }
                KERNEL_DEBUG(DBG_FNC_PCB_LOOKUP | DBG_FUNC_END, match,0,0,0,0);
                return (match);
        }
}

/*
 * Lookup PCB in hash list.
 */
struct inpcb *
in_pcblookup_hash(pcbinfo, faddr, fport_arg, laddr, lport_arg, wildcard, ifp)
        struct inpcbinfo *pcbinfo;
        struct in_addr faddr, laddr;
        u_int fport_arg, lport_arg;
        int wildcard;
        struct ifnet *ifp;
{
        struct inpcbhead *head;
        register struct inpcb *inp;
        u_short fport = fport_arg, lport = lport_arg;

        /*
         * We may have found the pcb in the last lookup - check this first.
         */

        if ((!IN_MULTICAST(laddr.s_addr)) && (pcbinfo->last_pcb)) {
            if (faddr.s_addr == pcbinfo->last_pcb->inp_faddr.s_addr &&
                laddr.s_addr == pcbinfo->last_pcb->inp_laddr.s_addr &&
                fport_arg    == pcbinfo->last_pcb->inp_fport &&
                lport_arg    == pcbinfo->last_pcb->inp_lport) {
                /*
                 * Found.
                 */
                return (pcbinfo->last_pcb);
            }

            pcbinfo->last_pcb = 0;
        }

        /*
         * First look for an exact match.
         */
        head = &pcbinfo->hashbase[INP_PCBHASH(faddr.s_addr, lport, fport, pcbinfo->hashmask)];
        for (inp = head->lh_first; inp != NULL; inp = inp->inp_hash.le_next) {
                if ((inp->inp_vflag & INP_IPV4) == NULL)
                        continue;
                if (inp->inp_faddr.s_addr == faddr.s_addr &&
                    inp->inp_laddr.s_addr == laddr.s_addr &&
                    inp->inp_fport == fport &&
                    inp->inp_lport == lport) {
                        /*
                         * Found.
                         */
                        return (inp);
                }
        }
        if (wildcard) {
                struct inpcb *local_wild = NULL;
#if INET6
                struct inpcb *local_wild_mapped = NULL;
#endif

                head = &pcbinfo->hashbase[INP_PCBHASH(INADDR_ANY, lport, 0, pcbinfo->hashmask)];
                for (inp = head->lh_first; inp != NULL; inp = inp->inp_hash.le_next) {
                        if ((inp->inp_vflag & INP_IPV4) == NULL)
                                continue;
                        if (inp->inp_faddr.s_addr == INADDR_ANY &&
                            inp->inp_lport == lport) {
#if defined(NFAITH) && NFAITH > 0
                                if (ifp && ifp->if_type == IFT_FAITH &&
                                    (inp->inp_flags & INP_FAITH) == 0)
                                        continue;
#endif
                                if (inp->inp_laddr.s_addr == laddr.s_addr)
                                        return (inp);
                                else if (inp->inp_laddr.s_addr == INADDR_ANY) {
#if INET6
                                        if (INP_CHECK_SOCKAF(inp->inp_socket,
                                                             AF_INET6))
                                                local_wild_mapped = inp;
                                        else
#endif
                                        local_wild = inp;
                                }
                        }
                }
#if INET6
                if (local_wild == NULL)
                        return (local_wild_mapped);
#endif
                return (local_wild);
        }

        /*
         * Not found.
         */
        return (NULL);
}

/*
 * Insert PCB onto various hash lists.
 */
int
in_pcbinshash(inp)
        struct inpcb *inp;
{
        struct inpcbhead *pcbhash;
        struct inpcbporthead *pcbporthash;
        struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
        struct inpcbport *phd;
        u_int32_t hashkey_faddr;

#if INET6
        if (inp->inp_vflag & INP_IPV6)
                hashkey_faddr = inp->in6p_faddr.s6_addr32[3] /* XXX */;
        else
#endif /* INET6 */
        hashkey_faddr = inp->inp_faddr.s_addr;

        pcbhash = &pcbinfo->hashbase[INP_PCBHASH(hashkey_faddr,
                 inp->inp_lport, inp->inp_fport, pcbinfo->hashmask)];

        pcbporthash = &pcbinfo->porthashbase[INP_PCBPORTHASH(inp->inp_lport,
            pcbinfo->porthashmask)];

        /*
         * Go through port list and look for a head for this lport.
         */
        for (phd = pcbporthash->lh_first; phd != NULL; phd = phd->phd_hash.le_next) {
                if (phd->phd_port == inp->inp_lport)
                        break;
        }
        /*
         * If none exists, malloc one and tack it on.
         */
        if (phd == NULL) {
                MALLOC(phd, struct inpcbport *, sizeof(struct inpcbport), M_PCB, M_WAITOK);
                if (phd == NULL) {
                        return (ENOBUFS); /* XXX */
                }
                phd->phd_port = inp->inp_lport;
                LIST_INIT(&phd->phd_pcblist);
                LIST_INSERT_HEAD(pcbporthash, phd, phd_hash);
        }
        inp->inp_phd = phd;
        LIST_INSERT_HEAD(&phd->phd_pcblist, inp, inp_portlist);
        LIST_INSERT_HEAD(pcbhash, inp, inp_hash);
        inp->hash_element = INP_PCBHASH(inp->inp_faddr.s_addr, inp->inp_lport, 
                                        inp->inp_fport, pcbinfo->hashmask);
        return (0);
}

/*
 * Move PCB to the proper hash bucket when { faddr, fport } have  been
 * changed. NOTE: This does not handle the case of the lport changing (the
 * hashed port list would have to be updated as well), so the lport must
 * not change after in_pcbinshash() has been called.
 */
void
in_pcbrehash(inp)
        struct inpcb *inp;
{
        struct inpcbhead *head;
        u_int32_t hashkey_faddr;

#if INET6
        if (inp->inp_vflag & INP_IPV6)
                hashkey_faddr = inp->in6p_faddr.s6_addr32[3] /* XXX */;
        else
#endif /* INET6 */
        hashkey_faddr = inp->inp_faddr.s_addr;

        head = &inp->inp_pcbinfo->hashbase[INP_PCBHASH(hashkey_faddr,
                inp->inp_lport, inp->inp_fport, inp->inp_pcbinfo->hashmask)];

        LIST_REMOVE(inp, inp_hash);
        LIST_INSERT_HEAD(head, inp, inp_hash);
        inp->hash_element = INP_PCBHASH(inp->inp_faddr.s_addr, inp->inp_lport, 
                                        inp->inp_fport, inp->inp_pcbinfo->hashmask);
}

/*
 * Remove PCB from various lists.
 */
void
in_pcbremlists(inp)
        struct inpcb *inp;
{
        inp->inp_gencnt = ++inp->inp_pcbinfo->ipi_gencnt;
        if (inp == inp->inp_pcbinfo->last_pcb)
            inp->inp_pcbinfo->last_pcb = 0;

        if (inp->inp_lport) {
                struct inpcbport *phd = inp->inp_phd;

                LIST_REMOVE(inp, inp_hash);
                LIST_REMOVE(inp, inp_portlist);
                if (phd->phd_pcblist.lh_first == NULL) {
                        LIST_REMOVE(phd, phd_hash);
                        FREE(phd, M_PCB);
                }
        }

        LIST_REMOVE(inp, inp_list);
        inp->inp_pcbinfo->ipi_count--;
}

int     
in_pcb_grab_port  __P((struct inpcbinfo *pcbinfo,
                       u_short          options,
                       struct in_addr   laddr, 
                       u_short          *lport,
                       struct in_addr   faddr,
                       u_short          fport,
                       u_int            cookie, 
                       u_char           owner_id))
{
    struct inpcb  *pcb;
    struct sockaddr_in sin;
    struct proc *p = current_proc();
    int  stat;


    pcbinfo->nat_dummy_socket.so_pcb = 0;
    pcbinfo->nat_dummy_socket.so_options = 0;
    if (*lport) {
        /* The grabber wants a particular port */

        if (faddr.s_addr || fport) {
            /*
             * This is either the second half of an active connect, or
             * it's from the acceptance of an incoming connection.
            */  
            if (laddr.s_addr == 0) {
                return EINVAL;
            }

            if (in_pcblookup_hash(pcbinfo, faddr, fport,
                                  laddr, *lport, 0, NULL) != NULL) {
                if (!(IN_MULTICAST(ntohl(laddr.s_addr)))) {
                    return (EADDRINUSE);
                }
            }
            
            stat = in_pcballoc(&pcbinfo->nat_dummy_socket, pcbinfo, p);
            if (stat)
                return stat;
            pcb = sotoinpcb(&pcbinfo->nat_dummy_socket);
            pcb->inp_vflag |= INP_IPV4;

            pcb->inp_lport = *lport;
            pcb->inp_laddr.s_addr = laddr.s_addr;

            pcb->inp_faddr = faddr;
            pcb->inp_fport = fport;
            in_pcbinshash(pcb);
        }
        else {
            /*
             * This is either a bind for a passive socket, or it's the 
             * first part of bind-connect sequence (not likely since an 
             * ephemeral port is usually used in this case). Or, it's
             * the result of a connection acceptance when the foreign
             * address/port cannot be provided (which requires the SO_REUSEADDR
             * flag if laddr is not multicast).
             */

            stat = in_pcballoc(&pcbinfo->nat_dummy_socket, pcbinfo, p);
            if (stat)
                return stat;
            pcb = sotoinpcb(&pcbinfo->nat_dummy_socket);
            pcb->inp_vflag |= INP_IPV4;

            pcbinfo->nat_dummy_socket.so_options = options; 
            bzero(&sin, sizeof(struct sockaddr_in));
            sin.sin_len = sizeof(struct sockaddr_in);
            sin.sin_family = AF_INET;
            sin.sin_addr.s_addr = laddr.s_addr;
            sin.sin_port = *lport;

            stat = in_pcbbind((struct inpcb *) pcbinfo->nat_dummy_socket.so_pcb, 
                              (struct sockaddr *) &sin, p);
            if (stat) {
                in_pcbdetach(pcb);
                return stat;
            }
        }
    }
    else {
        /* The grabber wants an ephemeral port */

        stat = in_pcballoc(&pcbinfo->nat_dummy_socket, pcbinfo, p);
        if (stat)
            return stat;
        pcb = sotoinpcb(&pcbinfo->nat_dummy_socket);
        pcb->inp_vflag |= INP_IPV4;

        bzero(&sin, sizeof(struct sockaddr_in));
        sin.sin_len = sizeof(struct sockaddr_in);
        sin.sin_family = AF_INET;
        sin.sin_addr.s_addr = laddr.s_addr;
        sin.sin_port = 0;

        if (faddr.s_addr || fport) {
            /*
             * Not sure if this case will be used - could occur when connect
             * is called, skipping the bind.
             */

            if (laddr.s_addr == 0) {
                in_pcbdetach(pcb);
                return EINVAL;
            }

            stat = in_pcbbind((struct inpcb *) pcbinfo->nat_dummy_socket.so_pcb, 
                              (struct sockaddr *) &sin, p);
            if (stat) {
                in_pcbdetach(pcb);
                return stat;
            }

            if (in_pcblookup_hash(pcbinfo, faddr, fport,
                                  pcb->inp_laddr, pcb->inp_lport, 0, NULL) != NULL) {
                in_pcbdetach(pcb);
                return (EADDRINUSE);
            }
            
            pcb->inp_faddr = faddr;
            pcb->inp_fport = fport;
            in_pcbrehash(pcb);
        }
        else {
            /*
             * This is a simple bind of an ephemeral port. The local addr
             * may or may not be defined.
             */
            
            stat = in_pcbbind((struct inpcb *) pcbinfo->nat_dummy_socket.so_pcb, 
                              (struct sockaddr *) &sin, p);
            if (stat) {
                in_pcbdetach(pcb);
                return stat;
            }
        }
        *lport = pcb->inp_lport;
    }
    

    pcb->nat_owner = owner_id;
    pcb->nat_cookie = cookie;
    pcb->inp_ppcb = (caddr_t) pcbinfo->dummy_cb;
    return 0;
}

int     
in_pcb_letgo_port __P((struct inpcbinfo *pcbinfo, struct in_addr laddr, u_short lport,
                       struct in_addr faddr, u_short fport, u_char owner_id))
{
    struct inpcbhead *head;
    register struct inpcb *inp;


    /*
     * First look for an exact match.
     */
    head = &pcbinfo->hashbase[INP_PCBHASH(faddr.s_addr, lport, fport, pcbinfo->hashmask)];
    for (inp = head->lh_first; inp != NULL; inp = inp->inp_hash.le_next) {
        if (inp->inp_faddr.s_addr == faddr.s_addr &&
            inp->inp_laddr.s_addr == laddr.s_addr &&
            inp->inp_fport == fport &&
            inp->inp_lport == lport &&
            inp->nat_owner == owner_id) {
            /*
             * Found.
             */
            in_pcbdetach(inp);
            return 0;
        }
    }

    return ENOENT;
}

u_char  
in_pcb_get_owner(struct inpcbinfo *pcbinfo,
                 struct in_addr laddr, u_short lport,
                 struct in_addr faddr, u_short fport,
                 u_int   *cookie)

{
    struct inpcb *inp;
    u_char       owner_id = INPCB_NO_OWNER;
    struct       inpcbport *phd;
    struct inpcbporthead *porthash;


    if (IN_MULTICAST(laddr.s_addr)) {
        /*
         * Walk through PCB's looking for registered
         * owners.
        */

        porthash = &pcbinfo->porthashbase[INP_PCBPORTHASH(lport,
                                                          pcbinfo->porthashmask)];
        for (phd = porthash->lh_first; phd != NULL; phd = phd->phd_hash.le_next) {
            if (phd->phd_port == lport)
                break;
        }

        if (phd == 0) {
            return INPCB_NO_OWNER;
        }
                
        owner_id = INPCB_NO_OWNER;
        for (inp = phd->phd_pcblist.lh_first; inp != NULL;
             inp = inp->inp_portlist.le_next) {

            if (inp->inp_laddr.s_addr == laddr.s_addr) {
                if (inp->nat_owner == 0) 
                    owner_id |= INPCB_OWNED_BY_X;
                else
                    owner_id |= inp->nat_owner;
            }
        }

        return owner_id;
    }
    else {
        inp = in_pcblookup_hash(pcbinfo, faddr, fport,
                                laddr, lport, 1, NULL);
        if (inp) {
            if (inp->nat_owner) {
                owner_id = inp->nat_owner;
                *cookie   = inp->nat_cookie;
            }
            else {
                pcbinfo->last_pcb = inp;
                owner_id = INPCB_OWNED_BY_X;
            }
        }
        else 
            owner_id = INPCB_NO_OWNER;

        return owner_id;
    }
}

int
in_pcb_new_share_client(struct inpcbinfo *pcbinfo, u_char *owner_id)
{

    int i;


    for (i=0; i < INPCB_MAX_IDS; i++) {
        if ((pcbinfo->all_owners & (1 << i)) == 0) {
            pcbinfo->all_owners |= (1 << i);
            *owner_id = (1 << i);
            return 0;
        }
    }

    return ENOSPC;
}               

int
in_pcb_rem_share_client(struct inpcbinfo *pcbinfo, u_char owner_id)
{
    struct inpcb *inp;


    if (pcbinfo->all_owners & owner_id) {
        pcbinfo->all_owners &= ~owner_id;
        for (inp = pcbinfo->listhead->lh_first; inp != NULL; inp = inp->inp_list.le_next) {
            if (inp->nat_owner & owner_id) {
                if (inp->nat_owner == owner_id) 
                    /*
                     * Deallocate the pcb
                     */
                    in_pcbdetach(inp);
                else
                    inp->nat_owner &= ~owner_id;
            }
        }
    }
    else {
        return ENOENT;
    }

    return 0;
}

void  in_pcb_nat_init(struct inpcbinfo *pcbinfo, int afamily, 
                      int pfamily, int protocol)
{
    bzero(&pcbinfo->nat_dummy_socket, sizeof(struct socket));
    pcbinfo->nat_dummy_socket.so_proto = pffindproto(afamily, pfamily, protocol);
    pcbinfo->all_owners = 0;
}