[apple/xnu.git] / bsd / netinet6 / in6_pcb.c

/*
 * Copyright (c) 2003-2007 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The 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, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * 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) 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. 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    8.2 (Berkeley) 1/4/94
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sockio.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/proc.h>

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

#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/ip6.h>
#include <netinet/ip_var.h>
#include <netinet6/ip6_var.h>
#include <netinet6/nd6.h>
#include <netinet/in_pcb.h>
#include <netinet6/in6_pcb.h>
#include <net/if_types.h>

#include <kern/kern_types.h>
#include <kern/zalloc.h>

#if IPSEC
#include <netinet6/ipsec.h>
#if INET6
#include <netinet6/ipsec6.h>
#endif
#include <netinet6/ah.h>
#if INET6
#include <netinet6/ah6.h>
#endif
#include <netkey/key.h>
#endif /* IPSEC */

struct  in6_addr zeroin6_addr;

/*
  in6_pcblookup_local_and_cleanup does everything
  in6_pcblookup_local does but it checks for a socket
  that's going away. Since we know that the lock is
  held read+write when this function is called, we
  can safely dispose of this socket like the slow
  timer would usually do and return NULL. This is
  great for bind.
*/
static struct inpcb*
in6_pcblookup_local_and_cleanup(
        struct inpcbinfo *pcbinfo,
        struct in6_addr *laddr,
        u_int lport_arg,
        int wild_okay)
{
        struct inpcb *inp;
        
        /* Perform normal lookup */
        inp = in6_pcblookup_local(pcbinfo, laddr, lport_arg, wild_okay);
        
        /* Check if we found a match but it's waiting to be disposed */
        if (inp && inp->inp_wantcnt == WNT_STOPUSING) {
                struct socket *so = inp->inp_socket;
                
                lck_mtx_lock(inp->inpcb_mtx);
                
                if (so->so_usecount == 0) {
                        in_pcbdispose(inp);
                        inp = NULL;
                }
                else {
                        lck_mtx_unlock(inp->inpcb_mtx);
                }
        }
        
        return inp;
}
int
in6_pcbbind(
        struct inpcb *inp,
        struct sockaddr *nam,
        struct proc *p)
{
        struct socket *so = inp->inp_socket;
        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)NULL;
        struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
        u_short lport = 0;
        int wild = 0, reuseport = (so->so_options & SO_REUSEPORT);

        if (!in6_ifaddrs) /* XXX broken! */
                return (EADDRNOTAVAIL);
        if (inp->inp_lport || !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
                return(EINVAL);
        if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0)
                wild = 1;
        socket_unlock(so, 0); /* keep reference */
        lck_rw_lock_exclusive(pcbinfo->mtx);
        if (nam) {
                sin6 = (struct sockaddr_in6 *)nam;
                if (nam->sa_len != sizeof(*sin6)) {
                        lck_rw_done(pcbinfo->mtx);
                        socket_lock(so, 0);
                        return(EINVAL);
                }
                /*
                 * family check.
                 */
                if (nam->sa_family != AF_INET6) {
                        lck_rw_done(pcbinfo->mtx);
                        socket_lock(so, 0);
                        return(EAFNOSUPPORT);
                }

                /* KAME hack: embed scopeid */
                if (in6_embedscope(&sin6->sin6_addr, sin6, inp, NULL) != 0) {
                        lck_rw_done(pcbinfo->mtx);
                        socket_lock(so, 0);
                        return EINVAL;
                }
                /* this must be cleared for ifa_ifwithaddr() */
                sin6->sin6_scope_id = 0;

                lport = sin6->sin6_port;
                if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) {
                        /*
                         * Treat SO_REUSEADDR as SO_REUSEPORT for multicast;
                         * allow compepte 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 (!IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
                        struct ifaddr *ia = NULL;

                        sin6->sin6_port = 0;            /* yech... */
                        if ((ia = ifa_ifwithaddr((struct sockaddr *)sin6)) == 0) {
                                lck_rw_done(pcbinfo->mtx);
                                socket_lock(so, 0);
                                return(EADDRNOTAVAIL);
                        }

                        /*
                         * XXX: bind to an anycast address might accidentally
                         * cause sending a packet with anycast source address.
                         * We should allow to bind to a deprecated address, since
                         * the application dare to use it.
                         */
                        if (ia &&
                            ((struct in6_ifaddr *)ia)->ia6_flags &
                            (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY|IN6_IFF_DETACHED)) {
                                ifafree(ia);
                                lck_rw_done(pcbinfo->mtx);
                                socket_lock(so, 0);
                                return(EADDRNOTAVAIL);
                        }
                        ifafree(ia);
                        ia = NULL;
                }
                if (lport) {
                        struct inpcb *t;

                        /* GROSS */
                        if (ntohs(lport) < IPV6PORT_RESERVED && p &&
                            ((so->so_state & SS_PRIV) == 0)) {
                                lck_rw_done(pcbinfo->mtx);
                                socket_lock(so, 0);
                                return(EACCES);
                        }

                        if (so->so_uid &&
                            !IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) {
                                t = in6_pcblookup_local_and_cleanup(pcbinfo,
                                    &sin6->sin6_addr, lport,
                                    INPLOOKUP_WILDCARD);
                                if (t &&
                                    (!IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr) ||
                                     !IN6_IS_ADDR_UNSPECIFIED(&t->in6p_laddr) ||
                                     (t->inp_socket->so_options &
                                      SO_REUSEPORT) == 0) &&
                                     (so->so_uid != t->inp_socket->so_uid) &&
                                     ((t->inp_socket->so_flags & SOF_REUSESHAREUID) == 0)) {
                                        lck_rw_done(pcbinfo->mtx);
                                        socket_lock(so, 0);
                                        return (EADDRINUSE);
                                }
                                if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0 &&
                                    IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
                                        struct sockaddr_in sin;

                                        in6_sin6_2_sin(&sin, sin6);
                                        t = in_pcblookup_local_and_cleanup(pcbinfo,
                                                sin.sin_addr, lport,
                                                INPLOOKUP_WILDCARD);
                                        if (t && (t->inp_socket->so_options & SO_REUSEPORT) == 0 &&
                                            (so->so_uid !=
                                             t->inp_socket->so_uid) &&
                                            (ntohl(t->inp_laddr.s_addr) !=
                                             INADDR_ANY ||
                                             INP_SOCKAF(so) ==
                                             INP_SOCKAF(t->inp_socket))) {

                                                lck_rw_done(pcbinfo->mtx);
                                                socket_lock(so, 0);
                                                return (EADDRINUSE);
                                        }
                                }
                        }
                        t = in6_pcblookup_local_and_cleanup(pcbinfo, &sin6->sin6_addr,
                                                lport, wild);
                        if (t && (reuseport & t->inp_socket->so_options) == 0) {
                                lck_rw_done(pcbinfo->mtx);
                                socket_lock(so, 0);
                                return(EADDRINUSE);
                        }
                        if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0 &&
                            IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
                                struct sockaddr_in sin;

                                in6_sin6_2_sin(&sin, sin6);
                                t = in_pcblookup_local_and_cleanup(pcbinfo, sin.sin_addr,
                                                       lport, wild);
                                if (t &&
                                    (reuseport & t->inp_socket->so_options)
                                    == 0 &&
                                    (ntohl(t->inp_laddr.s_addr)
                                     != INADDR_ANY ||
                                     INP_SOCKAF(so) ==
                                     INP_SOCKAF(t->inp_socket))) {
                                        lck_rw_done(pcbinfo->mtx);
                                        socket_lock(so, 0);
                                        return (EADDRINUSE);
                                }
                        }
                }
                inp->in6p_laddr = sin6->sin6_addr;
        }
        socket_lock(so, 0);
        if (lport == 0) {
                int e;
                if ((e = in6_pcbsetport(&inp->in6p_laddr, inp, p, 1)) != 0) {
                        lck_rw_done(pcbinfo->mtx);
                        return(e);
                }
        }
        else {
                inp->inp_lport = lport;
                if (in_pcbinshash(inp, 1) != 0) {
                        inp->in6p_laddr = in6addr_any;
                        inp->inp_lport = 0;
                        lck_rw_done(pcbinfo->mtx);
                        return (EAGAIN);
                }
        }       
        lck_rw_done(pcbinfo->mtx);
        sflt_notify(so, sock_evt_bound, NULL);
        return(0);
}

/*
 *   Transform old in6_pcbconnect() into an inner subroutine for new
 *   in6_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 in6_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
in6_pcbladdr(
        struct inpcb *inp,
        struct sockaddr *nam,
        struct in6_addr *plocal_addr6)
{
        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
        struct in6_addr *addr6 = NULL;
        struct in6_addr src_storage;
        
        struct ifnet *ifp = NULL;
        int error = 0;

        if (nam->sa_len != sizeof (*sin6))
                return (EINVAL);
        if (sin6->sin6_family != AF_INET6)
                return (EAFNOSUPPORT);
        if (sin6->sin6_port == 0)
                return (EADDRNOTAVAIL);

        /* KAME hack: embed scopeid */
        if (in6_embedscope(&sin6->sin6_addr, sin6, inp, &ifp) != 0)
                return EINVAL;

        if (in6_ifaddrs) {
                /*
                 * If the destination address is UNSPECIFIED addr,
                 * use the loopback addr, e.g ::1.
                 */
                if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr))
                        sin6->sin6_addr = in6addr_loopback;
        }
        {
                /*
                 * XXX: in6_selectsrc might replace the bound local address
                 * with the address specified by setsockopt(IPV6_PKTINFO).
                 * Is it the intended behavior?
                 */
                addr6 = in6_selectsrc(sin6, inp->in6p_outputopts,
                                              inp->in6p_moptions,
                                              &inp->in6p_route,
                                              &inp->in6p_laddr, &src_storage, &error);
                if (addr6 == 0) {
                        if (error == 0)
                                error = EADDRNOTAVAIL;
                        return(error);
                }
                *plocal_addr6 = *addr6;
                /*
                 * Don't do pcblookup call here; return interface in
                 * plocal_addr6
                 * and exit to caller, that will do the lookup.
                 */
        }

        if (inp->in6p_route.ro_rt)
                ifp = inp->in6p_route.ro_rt->rt_ifp;

        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
in6_pcbconnect(inp, nam, p)
        struct inpcb *inp;
        struct sockaddr *nam;
        struct proc *p;
{
        struct in6_addr addr6;
        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
        struct inpcb *pcb;
        int error;

        /*
         * Call inner routine, to assign local interface address.
         * in6_pcbladdr() may automatically fill in sin6_scope_id.
         */
        if ((error = in6_pcbladdr(inp, nam, &addr6)) != 0)
                return(error);
        socket_unlock(inp->inp_socket, 0);
        pcb = in6_pcblookup_hash(inp->inp_pcbinfo, &sin6->sin6_addr,
                               sin6->sin6_port,
                              IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)
                              ? &addr6 : &inp->in6p_laddr,
                              inp->inp_lport, 0, NULL);
        socket_lock(inp->inp_socket, 0);
        if (pcb != NULL) {
                in_pcb_checkstate(pcb, WNT_RELEASE, 0);
                return (EADDRINUSE);
        }
        if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
                if (inp->inp_lport == 0) {
                        error = in6_pcbbind(inp, (struct sockaddr *)0, p);
                        if (error)
                                return (error);
                }
                inp->in6p_laddr = addr6;
        }
        if (!lck_rw_try_lock_exclusive(inp->inp_pcbinfo->mtx)) {
                /*lock inversion issue, mostly with udp multicast packets */
                socket_unlock(inp->inp_socket, 0);
                lck_rw_lock_exclusive(inp->inp_pcbinfo->mtx);
                socket_lock(inp->inp_socket, 0);
        }
        inp->in6p_faddr = sin6->sin6_addr;
        inp->inp_fport = sin6->sin6_port;
        /* update flowinfo - draft-itojun-ipv6-flowlabel-api-00 */
        inp->in6p_flowinfo &= ~IPV6_FLOWLABEL_MASK;
        if (inp->in6p_flags & IN6P_AUTOFLOWLABEL)
                inp->in6p_flowinfo |=
                    (htonl(ip6_flow_seq++) & IPV6_FLOWLABEL_MASK);

        in_pcbrehash(inp);
        lck_rw_done(inp->inp_pcbinfo->mtx);
        return (0);
}

#if 0
/*
 * Return an IPv6 address, which is the most appropriate for given
 * destination and user specified options.
 * If necessary, this function lookups the routing table and return
 * an entry to the caller for later use.
 */
struct in6_addr *
in6_selectsrc(
        struct sockaddr_in6 *dstsock,
        struct ip6_pktopts *opts,
        struct ip6_moptions *mopts,
        struct route_in6 *ro,
        struct in6_addr *laddr,
        struct in6_addr *src_storage,
        int *errorp)
{
        struct in6_addr *dst;
        struct in6_ifaddr *ia6 = 0;
        struct in6_pktinfo *pi = NULL;

        dst = &dstsock->sin6_addr;
        *errorp = 0;

        /*
         * If the source address is explicitly specified by the caller,
         * use it.
         */
        if (opts && (pi = opts->ip6po_pktinfo) &&
            !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr))
                return(&pi->ipi6_addr);

        /*
         * If the source address is not specified but the socket(if any)
         * is already bound, use the bound address.
         */
        if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr))
                return(laddr);

        /*
         * If the caller doesn't specify the source address but
         * the outgoing interface, use an address associated with
         * the interface.
         */
        if (pi && pi->ipi6_ifindex) {
                /* XXX boundary check is assumed to be already done. */
                ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex],
                                       dst);
                if (ia6 == 0) {
                        *errorp = EADDRNOTAVAIL;
                        return(0);
                }
                *src_storage = satosin6(&ia6->ia_addr)->sin6_addr;
                ifafree(&ia6->ia_ifa);
                return(src_storage);
        }

        /*
         * If the destination address is a link-local unicast address or
         * a multicast address, and if the outgoing interface is specified
         * by the sin6_scope_id filed, use an address associated with the
         * interface.
         * XXX: We're now trying to define more specific semantics of
         *      sin6_scope_id field, so this part will be rewritten in
         *      the near future.
         */
        if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MULTICAST(dst)) &&
            dstsock->sin6_scope_id) {
                /*
                 * I'm not sure if boundary check for scope_id is done
                 * somewhere...
                 */
                if (dstsock->sin6_scope_id < 0 ||
                    if_index < dstsock->sin6_scope_id) {
                        *errorp = ENXIO; /* XXX: better error? */
                        return(0);
                }
                ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id],
                                       dst);
                if (ia6 == 0) {
                        *errorp = EADDRNOTAVAIL;
                        return(0);
                }
                *src_storage = satosin6(&ia6->ia_addr)->sin6_addr;
                ifafree(&ia6->ia_ifa);
                return(src_storage);
        }

        /*
         * If the destination address is a multicast address and
         * the outgoing interface for the address is specified
         * by the caller, use an address associated with the interface.
         * There is a sanity check here; if the destination has node-local
         * scope, the outgoing interfacde should be a loopback address.
         * Even if the outgoing interface is not specified, we also
         * choose a loopback interface as the outgoing interface.
         */
        if (IN6_IS_ADDR_MULTICAST(dst)) {
                struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL;

                if (ifp == NULL && IN6_IS_ADDR_MC_NODELOCAL(dst)) {
                        ifp = lo_ifp;
                }

                if (ifp) {
                        ia6 = in6_ifawithscope(ifp, dst);
                        if (ia6 == 0) {
                                *errorp = EADDRNOTAVAIL;
                                return(0);
                        }
                        *src_storage = ia6->ia_addr.sin6_addr;
                        ifafree(&ia6->ia_ifa);
                        return(src_storage);
                }
        }

        /*
         * If the next hop address for the packet is specified
         * by caller, use an address associated with the route
         * to the next hop.
         */
        {
                struct sockaddr_in6 *sin6_next;
                struct rtentry *rt;

                if (opts && opts->ip6po_nexthop) {
                        sin6_next = satosin6(opts->ip6po_nexthop);
                        rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL, 0);
                        if (rt) {
                                ia6 = in6_ifawithscope(rt->rt_ifp, dst);
                                if (ia6 == 0) {
                                        ifaref(&rt->rt_ifa);
                                        ia6 = ifatoia6(rt->rt_ifa);
                                }
                        }
                        if (ia6 == 0) {
                                *errorp = EADDRNOTAVAIL;
                                return(0);
                        }
                        *src_storage = satosin6(&ia6->ia_addr)->sin6_addr;
                        ifaref(&rt->rt_ifa);
                        return(src_storage);
                }
        }

        /*
         * If route is known or can be allocated now,
         * our src addr is taken from the i/f, else punt.
         */
        if (ro) {
                if (ro->ro_rt &&
                    !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst)) {
                        rtfree(ro->ro_rt);
                        ro->ro_rt = (struct rtentry *)0;
                }
                if (ro->ro_rt == (struct rtentry *)0 ||
                    ro->ro_rt->rt_ifp == (struct ifnet *)0) {
                        struct sockaddr_in6 *dst6;

                        /* No route yet, so try to acquire one */
                        bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
                        dst6 = (struct sockaddr_in6 *)&ro->ro_dst;
                        dst6->sin6_family = AF_INET6;
                        dst6->sin6_len = sizeof(struct sockaddr_in6);
                        dst6->sin6_addr = *dst;
                        if (IN6_IS_ADDR_MULTICAST(dst)) {
                                ro->ro_rt =
                                    rtalloc1(&((struct route *)ro)->ro_dst, 0, 0UL);
                        } else {
                                rtalloc((struct route *)ro);
                        }
                }

                /*
                 * in_pcbconnect() checks out IFF_LOOPBACK to skip using
                 * the address. But we don't know why it does so.
                 * It is necessary to ensure the scope even for lo0
                 * so doesn't check out IFF_LOOPBACK.
                 */

                if (ro->ro_rt) {
                        ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst);
                        if (ia6 == 0) { /* xxx scope error ?*/
                                ifaref(ro->ro_rt->rt_ifa);
                                ia6 = ifatoia6(ro->ro_rt->rt_ifa);
                        }
                }
                if (ia6 == 0) {
                        *errorp = EHOSTUNREACH; /* no route */
                        return(0);
                }
                *src_storage = satosin6(&ia6->ia_addr)->sin6_addr;
                ifaref(&rt->rt_ifa);
                return(src_storage);
        }

        *errorp = EADDRNOTAVAIL;
        return(0);
}

/*
 * Default hop limit selection. The precedence is as follows:
 * 1. Hoplimit valued specified via ioctl.
 * 2. (If the outgoing interface is detected) the current
 *     hop limit of the interface specified by router advertisement.
 * 3. The system default hoplimit.
*/
int
in6_selecthlim(
        struct in6pcb *in6p,
        struct ifnet *ifp)
{
        if (in6p && in6p->in6p_hops >= 0)
                return(in6p->in6p_hops);
        else if (ifp)
                return(nd_ifinfo[ifp->if_index].chlim);
        else
                return(ip6_defhlim);
}
#endif

void
in6_pcbdisconnect(inp)
        struct inpcb *inp;
{
        if (!lck_rw_try_lock_exclusive(inp->inp_pcbinfo->mtx)) {
                /*lock inversion issue, mostly with udp multicast packets */
                socket_unlock(inp->inp_socket, 0);
                lck_rw_lock_exclusive(inp->inp_pcbinfo->mtx);
                socket_lock(inp->inp_socket, 0);
        }
        bzero((caddr_t)&inp->in6p_faddr, sizeof(inp->in6p_faddr));
        inp->inp_fport = 0;
        /* clear flowinfo - draft-itojun-ipv6-flowlabel-api-00 */
        inp->in6p_flowinfo &= ~IPV6_FLOWLABEL_MASK;
        in_pcbrehash(inp);
        lck_rw_done(inp->inp_pcbinfo->mtx);
        if (inp->inp_socket->so_state & SS_NOFDREF)
                in6_pcbdetach(inp);
}

void
in6_pcbdetach(inp)
        struct inpcb *inp;
{
        struct socket *so = inp->inp_socket;
        struct inpcbinfo *ipi = inp->inp_pcbinfo;

#if IPSEC
        if (inp->in6p_sp != NULL) {
                ipsec6_delete_pcbpolicy(inp);
        }
#endif /* IPSEC */

        if (in_pcb_checkstate(inp, WNT_STOPUSING, 1) != WNT_STOPUSING)
                printf("in6_pcbdetach so=%p can't be marked dead ok\n", so);

        inp->inp_state = INPCB_STATE_DEAD;

        if ((so->so_flags & SOF_PCBCLEARING) == 0) {
                inp->inp_vflag = 0;
                so->so_flags |= SOF_PCBCLEARING;
                inp->inp_gencnt = ++ipi->ipi_gencnt;
                if (inp->in6p_options)
                        m_freem(inp->in6p_options);
                ip6_freepcbopts(inp->in6p_outputopts);
                ip6_freemoptions(inp->in6p_moptions);
                if (inp->in6p_route.ro_rt)
                        rtfree(inp->in6p_route.ro_rt);
                /* Check and free IPv4 related resources in case of mapped addr */
                if (inp->inp_options)
                        (void)m_free(inp->inp_options);
                ip_freemoptions(inp->inp_moptions);
                inp->inp_moptions = NULL;
        
        }
}

struct sockaddr *
in6_sockaddr(port, addr_p)
        in_port_t port;
        struct in6_addr *addr_p;
{
        struct sockaddr_in6 *sin6;

        MALLOC(sin6, struct sockaddr_in6 *, sizeof *sin6, M_SONAME, M_WAITOK);
        bzero(sin6, sizeof *sin6);
        sin6->sin6_family = AF_INET6;
        sin6->sin6_len = sizeof(*sin6);
        sin6->sin6_port = port;
        sin6->sin6_addr = *addr_p;
        if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr))
                sin6->sin6_scope_id = ntohs(sin6->sin6_addr.s6_addr16[1]);
        else
                sin6->sin6_scope_id = 0;        /*XXX*/
        if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr))
                sin6->sin6_addr.s6_addr16[1] = 0;

        return (struct sockaddr *)sin6;
}

struct sockaddr *
in6_v4mapsin6_sockaddr(port, addr_p)
        in_port_t port;
        struct in_addr *addr_p;
{
        struct sockaddr_in sin;
        struct sockaddr_in6 *sin6_p;

        bzero(&sin, sizeof sin);
        sin.sin_family = AF_INET;
        sin.sin_len = sizeof(sin);
        sin.sin_port = port;
        sin.sin_addr = *addr_p;

        MALLOC(sin6_p, struct sockaddr_in6 *, sizeof *sin6_p, M_SONAME,
                M_WAITOK);
        in6_sin_2_v4mapsin6(&sin, sin6_p);

        return (struct sockaddr *)sin6_p;
}

/*
 * The calling convention of in6_setsockaddr() and in6_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
in6_setsockaddr(so, nam)
        struct socket *so;
        struct sockaddr **nam;
{
        struct inpcb *inp;
        struct in6_addr addr;
        in_port_t port;

        inp = sotoinpcb(so);
        if (!inp) {
                return EINVAL;
        }
        port = inp->inp_lport;
        addr = inp->in6p_laddr;

        *nam = in6_sockaddr(port, &addr);
        return 0;
}

int
in6_setpeeraddr(so, nam)
        struct socket *so;
        struct sockaddr **nam;
{
        struct inpcb *inp;
        struct in6_addr addr;
        in_port_t port;

        inp = sotoinpcb(so);
        if (!inp) {
                return EINVAL;
        }
        port = inp->inp_fport;
        addr = inp->in6p_faddr;

        *nam = in6_sockaddr(port, &addr);
        return 0;
}

int
in6_mapped_sockaddr(struct socket *so, struct sockaddr **nam)
{
        struct  inpcb *inp = sotoinpcb(so);
        int     error;

        if (inp == NULL)
                return EINVAL;
        if (inp->inp_vflag & INP_IPV4) {
                error = in_setsockaddr(so, nam);
                if (error == 0)
                        in6_sin_2_v4mapsin6_in_sock(nam);
        } else
        /* scope issues will be handled in in6_setsockaddr(). */
        error = in6_setsockaddr(so, nam);

        return error;
}

int
in6_mapped_peeraddr(struct socket *so, struct sockaddr **nam)
{
        struct  inpcb *inp = sotoinpcb(so);
        int     error;

        if (inp == NULL)
                return EINVAL;
        if (inp->inp_vflag & INP_IPV4) {
                error = in_setpeeraddr(so, nam);
                if (error == 0)
                        in6_sin_2_v4mapsin6_in_sock(nam);
        } else
        /* scope issues will be handled in in6_setpeeraddr(). */
        error = in6_setpeeraddr(so, nam);

        return error;
}

/*
 * 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.
 *
 * Must be called at splnet.
 */
void
in6_pcbnotify(pcbinfo, dst, fport_arg, src, lport_arg, cmd, notify)
        struct inpcbinfo *pcbinfo;
        struct sockaddr *dst;
        const struct sockaddr *src;
        u_int fport_arg, lport_arg;
        int cmd;
//      struct inpcb *(*notify)(struct inpcb *, int);
        void (*notify)(struct inpcb *, int);
{
        struct inpcb *inp, *ninp;
        struct sockaddr_in6 sa6_src, *sa6_dst;
        u_short fport = fport_arg, lport = lport_arg;
        u_int32_t flowinfo;
        int errno;
        struct inpcbhead *head = pcbinfo->listhead;

        if ((unsigned)cmd > PRC_NCMDS || dst->sa_family != AF_INET6)
                return;

        sa6_dst = (struct sockaddr_in6 *)dst;
        if (IN6_IS_ADDR_UNSPECIFIED(&sa6_dst->sin6_addr))
                return;

        /*
         * note that src can be NULL when we get notify by local fragmentation.
         */
        sa6_src = (src == NULL) ? sa6_any : *(const struct sockaddr_in6 *)src;
        flowinfo = sa6_src.sin6_flowinfo;

        /*
         * Redirects go to all references to the destination,
         * and use in6_rtchange to invalidate the route cache.
         * Dead host indications: also use in6_rtchange to invalidate
         * the cache, and deliver the error to all the sockets.
         * 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;
                bzero((caddr_t)&sa6_src.sin6_addr, sizeof(sa6_src.sin6_addr));

                if (cmd != PRC_HOSTDEAD)
                        notify = in6_rtchange;
        }
        errno = inet6ctlerrmap[cmd];
        lck_rw_lock_shared(pcbinfo->mtx);
        for (inp = LIST_FIRST(head); inp != NULL; inp = ninp) {
                ninp = LIST_NEXT(inp, inp_list);

                if ((inp->inp_vflag & INP_IPV6) == 0)
                        continue;

                /*
                 * Detect if we should notify the error. If no source and
                 * destination ports are specifed, but non-zero flowinfo and
                 * local address match, notify the error. This is the case
                 * when the error is delivered with an encrypted buffer
                 * by ESP. Otherwise, just compare addresses and ports
                 * as usual.
                 */
                if (lport == 0 && fport == 0 && flowinfo &&
                    inp->inp_socket != NULL &&
                    flowinfo == (inp->in6p_flowinfo & IPV6_FLOWLABEL_MASK) &&
                    IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &sa6_src.sin6_addr))
                        goto do_notify;
                else if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
                                             &sa6_dst->sin6_addr) ||
                         inp->inp_socket == 0 ||
                         (lport && inp->inp_lport != lport) ||
                         (!IN6_IS_ADDR_UNSPECIFIED(&sa6_src.sin6_addr) &&
                          !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
                                              &sa6_src.sin6_addr)) ||
                         (fport && inp->inp_fport != fport)) 
                        continue;
                     

          do_notify:
                if (notify) {
                        if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) == WNT_STOPUSING)
                                continue;
                        socket_lock(inp->inp_socket, 1);
                        (*notify)(inp, errno);
                        (void)in_pcb_checkstate(inp, WNT_RELEASE, 1);
                        socket_unlock(inp->inp_socket, 1);
                }
        }
        lck_rw_done(pcbinfo->mtx);
}

/*
 * Lookup a PCB based on the local address and port.
 */
struct inpcb *
in6_pcblookup_local(pcbinfo, laddr, lport_arg, wild_okay)
        struct inpcbinfo *pcbinfo;
        struct in6_addr *laddr;
        u_int lport_arg;
        int wild_okay;
{
        struct inpcb *inp;
        int matchwild = 3, wildcard;
        u_short lport = lport_arg;

        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)];
                LIST_FOREACH(inp, head, inp_hash) {
                        if ((inp->inp_vflag & INP_IPV6) == 0)
                                continue;
                        if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) &&
                            IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, laddr) &&
                            inp->inp_lport == lport) {
                                /*
                                 * Found.
                                 */
                                return (inp);
                        }
                }
                /*
                 * Not found.
                 */
                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)];
                LIST_FOREACH(phd, porthash, phd_hash) {
                        if (phd->phd_port == lport)
                                break;
                }
                if (phd != NULL) {
                        /*
                         * Port is in use by one or more PCBs. Look for best
                         * fit.
                         */
                        LIST_FOREACH(inp, &phd->phd_pcblist, inp_portlist) {
                                wildcard = 0;
                                if ((inp->inp_vflag & INP_IPV6) == 0)
                                        continue;
                                if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
                                        wildcard++;
                                if (!IN6_IS_ADDR_UNSPECIFIED(
                                        &inp->in6p_laddr)) {
                                        if (IN6_IS_ADDR_UNSPECIFIED(laddr))
                                                wildcard++;
                                        else if (!IN6_ARE_ADDR_EQUAL(
                                                &inp->in6p_laddr, laddr))
                                                continue;
                                } else {
                                        if (!IN6_IS_ADDR_UNSPECIFIED(laddr))
                                                wildcard++;
                                }
                                if (wildcard < matchwild) {
                                        match = inp;
                                        matchwild = wildcard;
                                        if (matchwild == 0) {
                                                break;
                                        }
                                }
                        }
                }
                return (match);
        }
}
#ifndef APPLE
/* this is not used in Darwin */
void
in6_pcbpurgeif0(
        struct in6pcb *head,
        struct ifnet *ifp)
{
        struct in6pcb *in6p;
        struct ip6_moptions *im6o;
        struct in6_multi_mship *imm, *nimm;

        for (in6p = head; in6p != NULL; in6p = LIST_NEXT(in6p, inp_list)) {
                im6o = in6p->in6p_moptions;
                if ((in6p->inp_vflag & INP_IPV6) &&
                    im6o) {
                        /*
                         * Unselect the outgoing interface if it is being
                         * detached.
                         */
                        if (im6o->im6o_multicast_ifp == ifp)
                                im6o->im6o_multicast_ifp = NULL;

                        /*
                         * Drop multicast group membership if we joined
                         * through the interface being detached.
                         * XXX controversial - is it really legal for kernel
                         * to force this?
                         */
                        for (imm = im6o->im6o_memberships.lh_first;
                             imm != NULL; imm = nimm) {
                                nimm = imm->i6mm_chain.le_next;
                                if (imm->i6mm_maddr->in6m_ifp == ifp) {
                                        LIST_REMOVE(imm, i6mm_chain);
                                        in6_delmulti(imm->i6mm_maddr);
                                        FREE(imm, M_IPMADDR);
                                }
                        }
                }
        }
}
#endif

/*
 * 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
in6_losing(in6p)
        struct inpcb *in6p;
{
        struct rtentry *rt;
        struct rt_addrinfo info;

        if ((rt = in6p->in6p_route.ro_rt) != NULL) {
                in6p->in6p_route.ro_rt = 0;
                bzero((caddr_t)&info, sizeof(info));
                info.rti_info[RTAX_DST] =
                        (struct sockaddr *)&in6p->in6p_route.ro_dst;
                info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
                info.rti_info[RTAX_NETMASK] = rt_mask(rt);
                lck_mtx_lock(rt_mtx);
                rt_missmsg(RTM_LOSING, &info, rt->rt_flags, 0);
                if (rt->rt_flags & RTF_DYNAMIC)
                        (void)rtrequest_locked(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_locked(rt);
                lck_mtx_unlock(rt_mtx);
        }
}

/*
 * After a routing change, flush old routing
 * and allocate a (hopefully) better one.
 */
void
in6_rtchange(
        struct inpcb *inp,
        __unused int errno)
{
        if (inp->in6p_route.ro_rt) {
                rtfree(inp->in6p_route.ro_rt);
                inp->in6p_route.ro_rt = 0;
                /*
                 * A new route can be allocated the next time
                 * output is attempted.
                 */
        }
}

/*
 * Lookup PCB in hash list.
 */
struct inpcb *
in6_pcblookup_hash(
        struct inpcbinfo *pcbinfo,
        struct in6_addr *faddr,
        u_int fport_arg,
        struct in6_addr *laddr,
        u_int lport_arg,
        int wildcard,
        __unused struct ifnet *ifp)
{
        struct inpcbhead *head;
        struct inpcb *inp;
        u_short fport = fport_arg, lport = lport_arg;
        int faith;

#if defined(NFAITH) && NFAITH > 0
        faith = faithprefix(laddr);
#else
        faith = 0;
#endif

        lck_rw_lock_shared(pcbinfo->mtx);

        /*
         * First look for an exact match.
         */
        head = &pcbinfo->hashbase[INP_PCBHASH(faddr->s6_addr32[3] /* XXX */,
                                              lport, fport,
                                              pcbinfo->hashmask)];
        LIST_FOREACH(inp, head, inp_hash) {
                if ((inp->inp_vflag & INP_IPV6) == 0)
                        continue;
                if (IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, faddr) &&
                    IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, laddr) &&
                    inp->inp_fport == fport &&
                    inp->inp_lport == lport) {
                        /*
                        * Found. Check if pcb is still valid
                        */
                        if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) != WNT_STOPUSING) {
                                lck_rw_done(pcbinfo->mtx);
                                return (inp);
                        }
                        else {  /* it's there but dead, say it isn't found */
                                lck_rw_done(pcbinfo->mtx);      
                                return(NULL);
                        }
                }
        }
        if (wildcard) {
                struct inpcb *local_wild = NULL;

                head = &pcbinfo->hashbase[INP_PCBHASH(INADDR_ANY, lport, 0,
                                                      pcbinfo->hashmask)];
                LIST_FOREACH(inp, head, inp_hash) {
                        if ((inp->inp_vflag & INP_IPV6) == 0)
                                continue;
                        if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) &&
                            inp->inp_lport == lport) {
                                if (faith && (inp->inp_flags & INP_FAITH) == 0)
                                        continue;
                                if (IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
                                                       laddr)) {
                                        if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) != WNT_STOPUSING) {
                                                lck_rw_done(pcbinfo->mtx);
                                                return (inp);
                                        }
                                        else {  /* it's there but dead, say it isn't found */
                                                lck_rw_done(pcbinfo->mtx);      
                                                return(NULL);
                                        }
                                }
                                else if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
                                        local_wild = inp;
                        }
                }
                if (local_wild && in_pcb_checkstate(local_wild, WNT_ACQUIRE, 0) != WNT_STOPUSING) {
                        lck_rw_done(pcbinfo->mtx);
                        return (local_wild);
                }
                else {
                        lck_rw_done(pcbinfo->mtx);
                        return (NULL);
                }
        }

        /*
         * Not found.
         */
        lck_rw_done(pcbinfo->mtx);
        return (NULL);
}

void
init_sin6(struct sockaddr_in6 *sin6, struct mbuf *m)
{
        struct ip6_hdr *ip;

        ip = mtod(m, struct ip6_hdr *);
        bzero(sin6, sizeof(*sin6));
        sin6->sin6_len = sizeof(*sin6);
        sin6->sin6_family = AF_INET6;
        sin6->sin6_addr = ip->ip6_src;
        if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr))
                sin6->sin6_addr.s6_addr16[1] = 0;
        sin6->sin6_scope_id =
                (m->m_pkthdr.rcvif && IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr))
                ? m->m_pkthdr.rcvif->if_index : 0;

        return;
}