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

/*
 * 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
 */

#ifdef __NetBSD__       /*XXX*/
#include "opt_ipsec.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.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 <netinet6/ip6_var.h>
#include <netinet6/nd6.h>
#include <netinet/in_pcb.h>
#include <netinet6/in6_pcb.h>
#include <net/if_types.h>

#include "faith.h"

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

struct in6_addr zeroin6_addr;

int
in6_pcbbind(inp, nam, p)
        register struct inpcb *inp;
        struct sockaddr *nam;
        struct proc *p;
{
        struct socket *so = inp->inp_socket;
        unsigned short *lastport;
        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);
        int error;

        if (!in6_ifaddr) /* 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 = INPLOOKUP_WILDCARD;
        if (nam) {
                if (nam->sa_len != sizeof(*sin6))
                        return(EINVAL);
                /*
                 * We should check the family, but old programs
                 * incorrectly fail to intialize it.
                 */
                if (nam->sa_family != AF_INET6)
                        return(EAFNOSUPPORT);
                sin6 = (struct sockaddr_in6 *)nam;

                /*
                 * If the scope of the destination is link-local, embed the
                 * interface index in the address.
                 */
                if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr)) {
                        /* XXX boundary check is assumed to be already done. */
                        /* XXX sin6_scope_id is weaker than advanced-api. */
                        struct in6_pktinfo *pi;
                        if (inp->in6p_outputopts &&
                            (pi = inp->in6p_outputopts->ip6po_pktinfo) &&
                            pi->ipi6_ifindex) {
                                sin6->sin6_addr.s6_addr16[1]
                                        = htons(pi->ipi6_ifindex);
                        } else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)
                                && inp->in6p_moptions
                                && inp->in6p_moptions->im6o_multicast_ifp) {
                                sin6->sin6_addr.s6_addr16[1] =
                                        htons(inp->in6p_moptions->im6o_multicast_ifp->if_index);
                        } else if (sin6->sin6_scope_id) {
                                /* boundary check */
                                if (sin6->sin6_scope_id < 0 
                                 || if_index < sin6->sin6_scope_id) {
                                        return ENXIO;  /* XXX EINVAL? */
                                }
                                sin6->sin6_addr.s6_addr16[1]
                                        = htons(sin6->sin6_scope_id & 0xffff);/*XXX*/
                                /* 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)
                                return(EADDRNOTAVAIL);

                        /*
                         * XXX: bind to an anycast address might accidentally
                         * cause sending a packet with anycast source address.
                         */
                        if (ia &&
                            ((struct in6_ifaddr *)ia)->ia6_flags &
                            (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY|
                             IN6_IFF_DETACHED|IN6_IFF_DEPRECATED)) {
                                return(EADDRNOTAVAIL);
                        }
                }
                if (lport) {
                        struct inpcb *t;

                        /* GROSS */
                        if (ntohs(lport) < IPV6PORT_RESERVED && p &&
#if 0
                            suser(p->p_ucred, &p->p_acflag))
#else
                            ((so->so_state & SS_PRIV) == 0))
#endif
                                return(EACCES);

                        if (so->so_uid &&
                            !IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) {
                                t = in6_pcblookup_local(inp->inp_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)
                                        return (EADDRINUSE);
                        }
                        t = in6_pcblookup_local(pcbinfo, &sin6->sin6_addr,
                                                lport, wild);
                        if (t && (reuseport & t->inp_socket->so_options) == 0)
                                return(EADDRINUSE);
                }
                inp->in6p_laddr = sin6->sin6_addr;
        }
        if (lport == 0) {
                ushort 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 0
                        if (p && (error = suser(p->p_ucred, &p->p_acflag)))
                                return error;
#else
                        if ((so->so_state & SS_PRIV) == 0)
                                return (EPERM);
#endif
                        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->in6p_laddr = in6addr_any;
                                        return (EAGAIN);
                                }
                                --*lastport;
                                if (*lastport > first || *lastport < last)
                                        *lastport = first;
                                lport = htons(*lastport);
                        } while (in6_pcblookup_local(pcbinfo,
                                 &inp->in6p_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->in6p_laddr = in6addr_any;
                                        return (EAGAIN);
                                }
                                ++*lastport;
                                if (*lastport < first || *lastport > last)
                                        *lastport = first;
                                lport = htons(*lastport);
                        } while (in6_pcblookup_local(pcbinfo,
                                 &inp->in6p_laddr, lport, wild));
                }
        }
        inp->inp_lport = lport;
        if (in_pcbinshash(inp) != 0) {
                inp->in6p_laddr = in6addr_any;
                inp->inp_lport = 0;
                return (EAGAIN);
        }
        inp->in6p_flowinfo = sin6 ? sin6->sin6_flowinfo : 0;    /*XXX*/
        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(inp, nam, plocal_addr6)
        register struct inpcb *inp;
        struct sockaddr *nam;
        struct in6_addr **plocal_addr6;
{
        register struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
        struct in6_pktinfo *pi;
        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);

        /*
         * If the scope of the destination is link-local, embed the interface
         * index in the address.
         */
        if (IN6_IS_SCOPE_LINKLOCAL(&sin6->sin6_addr)) {
                /* XXX boundary check is assumed to be already done. */
                /* XXX sin6_scope_id is weaker than advanced-api. */
                if (inp->in6p_outputopts &&
                    (pi = inp->in6p_outputopts->ip6po_pktinfo) &&
                    pi->ipi6_ifindex) {
                        sin6->sin6_addr.s6_addr16[1] = htons(pi->ipi6_ifindex);
                        ifp = ifindex2ifnet[pi->ipi6_ifindex];
                }
                else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr) &&
                         inp->in6p_moptions &&
                         inp->in6p_moptions->im6o_multicast_ifp) {
                        sin6->sin6_addr.s6_addr16[1] =
                                htons(inp->in6p_moptions->im6o_multicast_ifp->if_index);
                        ifp = ifindex2ifnet[inp->in6p_moptions->im6o_multicast_ifp->if_index];
                } else if (sin6->sin6_scope_id) {
                        /* boundary check */
                        if (sin6->sin6_scope_id < 0 
                         || if_index < sin6->sin6_scope_id) {
                                return ENXIO;  /* XXX EINVAL? */
                        }
                        sin6->sin6_addr.s6_addr16[1]
                                = htons(sin6->sin6_scope_id & 0xffff);/*XXX*/
                        ifp = ifindex2ifnet[sin6->sin6_scope_id];
                }
        }

        if (in6_ifaddr) {
                /*
                 * If the destination address is UNSPECIFIED addr,
                 * use the loopback addr, e.g ::1.
                 */
#define satosin6(sa)    ((struct sockaddr_in6 *)(sa))
#define ifatoia6(ifa)   ((struct in6_ifaddr *)(ifa))
                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?
                 */
                *plocal_addr6 = in6_selectsrc(sin6, inp->in6p_outputopts,
                                              inp->in6p_moptions,
                                              &inp->in6p_route,
                                              &inp->in6p_laddr, &error);
                if (*plocal_addr6 == 0) {
                        if (error == 0)
                                error = EADDRNOTAVAIL;
                        return(error);
                }
                /*
                 * 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)
        register struct inpcb *inp;
        struct sockaddr *nam;
        struct proc *p;
{
        struct in6_addr *addr6;
        register struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
        int error;

        /*
         *   Call inner routine, to assign local interface address.
         */
        if (error = in6_pcbladdr(inp, nam, &addr6))
                return(error);

        if (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) != NULL) {
                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;
        }
        inp->in6p_faddr = sin6->sin6_addr;
        inp->inp_fport = sin6->sin6_port;
        /*
         * xxx kazu flowlabel is necessary for connect?
         * but if this line is missing, the garbage value remains.
         */
        inp->in6p_flowinfo = sin6->sin6_flowinfo;

        in_pcbrehash(inp);
        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(dstsock, opts, mopts, ro, laddr, errorp)
        struct sockaddr_in6 *dstsock;
        struct ip6_pktopts *opts;
        struct ip6_moptions *mopts;
        struct route_in6 *ro;
        struct in6_addr *laddr;
        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);
                }
                return(&satosin6(&ia6->ia_addr)->sin6_addr);
        }

        /*
         * 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);
                }
                return(&satosin6(&ia6->ia_addr)->sin6_addr);
        }

        /*
         * 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;
#ifdef __bsdi__
                extern struct ifnet loif;
#endif

                if (ifp == NULL && IN6_IS_ADDR_MC_NODELOCAL(dst)) {
#ifdef __bsdi__
                        ifp = &loif;
#else
                        ifp = &loif[0];
#endif
                }

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

        /*
         * 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);
                        if (rt) {
                                ia6 = in6_ifawithscope(rt->rt_ifp, dst);
                                if (ia6 == 0)
                                        ia6 = ifatoia6(rt->rt_ifa);
                        }
                        if (ia6 == 0) {
                                *errorp = EADDRNOTAVAIL;
                                return(0);
                        }
                        return(&satosin6(&ia6->ia_addr)->sin6_addr);
                }
        }

        /*
         * 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) {
                        /* No route yet, so try to acquire one */
                        bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
                        ro->ro_dst.sin6_family = AF_INET6;
                        ro->ro_dst.sin6_len = sizeof(struct sockaddr_in6);
                        ro->ro_dst.sin6_addr = *dst;
                        if (IN6_IS_ADDR_MULTICAST(dst)) {
#if defined(__FreeBSD__) || defined (__APPLE__)
                                ro->ro_rt = rtalloc1(&((struct route *)ro)
                                                     ->ro_dst, 0, 0UL);
#endif /*__FreeBSD__*/
#if defined(__bsdi__) || defined(__NetBSD__)
                                ro->ro_rt = rtalloc1(&((struct route *)ro)
                                                     ->ro_dst, 0);
#endif /*__bsdi__*/
                        } 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 ?*/
                                ia6 = ifatoia6(ro->ro_rt->rt_ifa);
                }
#if 0
                /*
                 * xxx The followings are necessary? (kazu)
                 * I don't think so.
                 * It's for SO_DONTROUTE option in IPv4.(jinmei)
                 */
                if (ia6 == 0) {
                        struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0};

                        sin6->sin6_addr = *dst;

                        ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6)));
                        if (ia6 == 0)
                                ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6)));
                        if (ia6 == 0) {
                                *errorp = EHOSTUNREACH; /* no route */
                                return(0);
                        }
                        return(&satosin6(&ia6->ia_addr)->sin6_addr);
                }
#endif /* 0 */
                if (ia6 == 0) {
                        *errorp = EHOSTUNREACH; /* no route */
                        return(0);
                }
                return(&satosin6(&ia6->ia_addr)->sin6_addr);
        }

        *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(in6p, ifp)
        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;
{
        bzero((caddr_t)&inp->in6p_faddr, sizeof(inp->in6p_faddr));
        inp->inp_fport = 0;
        in_pcbrehash(inp);
        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
        ipsec6_delete_pcbpolicy(inp);
#endif /* IPSEC */
        inp->inp_gencnt = ++ipi->ipi_gencnt;
        in_pcbremlists(inp);
        sotoinpcb(so) = 0;
        sofree(so);

        if (inp->in6p_inputopts) /* Free all received options. */
                m_freem(inp->in6p_inputopts->head); /* this is safe */
        ip6_freepcbopts(inp->in6p_outputopts);
        ip6_freemoptions(inp->in6p_moptions);

        if (inp->in6p_route.ro_rt)
                rtfree(inp->in6p_route.ro_rt);
        inp->inp_vflag = 0;
        zfree(ipi->ipi_zone, inp);
}

/*
 * 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;
{
        int s;
        register struct inpcb *inp;
        register struct sockaddr_in6 *sin6;

        /*
         * Do the malloc first in case it blocks.
         */
        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);

        s = splnet();
        inp = sotoinpcb(so);
        if (!inp) {
                splx(s);
                _FREE(sin6, M_SONAME);
                return EINVAL;
        }
        sin6->sin6_port = inp->inp_lport;
        sin6->sin6_addr = inp->in6p_laddr;
        splx(s);
        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;

        *nam = (struct sockaddr *)sin6;
        return 0;
}

int
in6_setpeeraddr(so, nam)
        struct socket *so;
        struct sockaddr **nam;
{
        int s;
        struct inpcb *inp;
        register struct sockaddr_in6 *sin6;

        /*
         * Do the malloc first in case it blocks.
         */
        MALLOC(sin6, struct sockaddr_in6 *, sizeof(*sin6), M_SONAME, M_WAITOK);
        bzero((caddr_t)sin6, sizeof (*sin6));
        sin6->sin6_family = AF_INET6;
        sin6->sin6_len = sizeof(struct sockaddr_in6);

        s = splnet();
        inp = sotoinpcb(so);
        if (!inp) {
                splx(s);
                _FREE(sin6, M_SONAME);
                return EINVAL;
        }
        sin6->sin6_port = inp->inp_fport;
        sin6->sin6_addr = inp->in6p_faddr;
        splx(s);
        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;

        *nam = (struct sockaddr *)sin6;
        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
        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
                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(head, dst, fport_arg, laddr6, lport_arg, cmd, notify)
        struct inpcbhead *head;
        struct sockaddr *dst;
        u_int fport_arg, lport_arg;
        struct in6_addr *laddr6;
        int cmd;
        void (*notify) __P((struct inpcb *, int));
{
        struct inpcb *inp, *ninp;
        struct in6_addr faddr6;
        u_short fport = fport_arg, lport = lport_arg;
        int errno, s;
        void (*notify2) __P((struct inpcb *, int));

        notify2 = NULL;

        if ((unsigned)cmd > PRC_NCMDS || dst->sa_family != AF_INET6)
                return;
        faddr6 = ((struct sockaddr_in6 *)dst)->sin6_addr;
        if (IN6_IS_ADDR_UNSPECIFIED(&faddr6))
                return;

        /*
         * 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)laddr6, sizeof(*laddr6));

                /*
                 * Keep the old notify function to store a soft error
                 * in each PCB.
                 */
                if (cmd == PRC_HOSTDEAD && notify != in6_rtchange)
                        notify2 = notify;

                notify = in6_rtchange;
        }
        errno = inet6ctlerrmap[cmd];
        s = splnet();
        for (inp = LIST_FIRST(head); inp != NULL; inp = ninp) {
                ninp = LIST_NEXT(inp, inp_list);

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

                if (notify == in6_rtchange) {
                        /*
                         * Since a non-connected PCB might have a cached route,
                         * we always call in6_rtchange without matching
                         * the PCB to the src/dst pair.
                         *
                         * XXX: we assume in6_rtchange does not free the PCB.
                         */
                        if (IN6_ARE_ADDR_EQUAL(&inp->in6p_route.ro_dst.sin6_addr,
                                               &faddr6))
                                in6_rtchange(inp, errno);

                        if (notify2 == NULL)
                                continue;

                        notify = notify2;
                }

                if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &faddr6) ||
                   inp->inp_socket == 0 ||
                   (lport && inp->inp_lport != lport) ||
                   (!IN6_IS_ADDR_UNSPECIFIED(laddr6) &&
                    !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, laddr6)) ||
                   (fport && inp->inp_fport != fport))
                        continue;

                if (notify)
                        (*notify)(inp, errno);
        }
        splx(s);
}

/*
 * 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;
{
        register 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);
        }
}

/*
 * 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);
                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.
 */
void
in6_rtchange(inp, errno)
        struct inpcb *inp;
        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(pcbinfo, faddr, fport_arg, laddr, lport_arg, wildcard, ifp)
        struct inpcbinfo *pcbinfo;
        struct in6_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;

        /*
         * First look for an exact match.
         */
        head = &pcbinfo->hashbase[INP_PCBHASH(faddr->s6_addr32[3] /* XXX */,
                                              lport, fport,
                                              pcbinfo->hashmask)];
        for (inp = head->lh_first; inp != NULL; inp = inp->inp_hash.le_next) {
                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.
                         */
                        return (inp);
                }
        }
        if (wildcard) {
                struct inpcb *local_wild = NULL;

                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_IPV6) == 0)
                                continue;
                        if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) &&
                            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 (IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
                                                       laddr))
                                        return (inp);
                                else if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
                                        local_wild = inp;
                        }
                }
                return (local_wild);
        }

        /*
         * Not found.
         */
        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;
}