dhcpcd: update README.DRAGONFLY

[dragonfly.git] / sys / netinet6 / in6_pcb.c

/*      $FreeBSD: src/sys/netinet6/in6_pcb.c,v 1.10.2.9 2003/01/24 05:11:35 sam Exp $   */
/*      $KAME: in6_pcb.c,v 1.31 2001/05/21 05:45:10 jinmei Exp $        */

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

/*
 * Copyright (c) 1982, 1986, 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)in_pcb.c    8.2 (Berkeley) 1/4/94
 */

#include "opt_inet.h"
#include "opt_inet6.h"

#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 <sys/caps.h>
#include <sys/jail.h>

#include <sys/msgport2.h>

#include <vm/vm_zone.h>

#include <net/if.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/netisr2.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>

struct  in6_addr zeroin6_addr;

int
in6_pcbbind(struct inpcb *inp, struct sockaddr *nam, struct thread *td)
{
        struct socket *so = inp->inp_socket;
        struct sockaddr_in6 jsin6;
        int error;

        if (inp->inp_lport || !IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
                return (EINVAL);

        if (nam) {
                struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
                struct inpcbinfo *pcbinfo;
                struct inpcbportinfo *portinfo;
                struct inpcbporthead *porthash;
                int wild = 0, reuseport = (so->so_options & SO_REUSEPORT);
                struct ucred *cred = NULL;
                struct inpcb *t;
                u_short lport, lport_ho;

                if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0)
                        wild = 1;
                if (td->td_proc != NULL)
                        cred = td->td_proc->p_ucred;

                if (nam->sa_len != sizeof(*sin6))
                        return (EINVAL);
                /*
                 * family check.
                 */
                if (nam->sa_family != AF_INET6)
                        return (EAFNOSUPPORT);

                /* Reject v4-mapped address */
                if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
                        return (EADDRNOTAVAIL);

                if (!prison_replace_wildcards(td, nam))
                        return (EINVAL);

                /* KAME hack: embed scopeid */
                if (in6_embedscope(&sin6->sin6_addr, sin6, inp, NULL) != 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 (!prison_replace_wildcards(td, (struct sockaddr *)sin6)) {
                                sin6->sin6_addr = kin6addr_any;
                                return (EINVAL);
                        }
                        if ((ia = ifa_ifwithaddr((struct sockaddr *)sin6)) == NULL)
                                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 dares to use it.
                         */
                        if (ia &&
                            ((struct in6_ifaddr *)ia)->ia6_flags &
                            (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY|IN6_IFF_DETACHED))
                                return (EADDRNOTAVAIL);
                }

                inp->in6p_laddr = sin6->sin6_addr;

                if (lport == 0)
                        goto auto_select;
                lport_ho = ntohs(lport);

                /* GROSS */
                if (lport_ho < IPV6PORT_RESERVED && cred &&
                    caps_priv_check(cred, SYSCAP_NONET_RESPORT))
                {
                        inp->in6p_laddr = kin6addr_any;
                        return (EACCES);
                }

                /*
                 * Locate the proper portinfo based on lport
                 */
                pcbinfo = inp->inp_pcbinfo;
                portinfo =
                    &pcbinfo->portinfo[lport_ho % pcbinfo->portinfo_cnt];
                KKASSERT((lport_ho % pcbinfo->portinfo_cnt) ==
                    portinfo->offset);

                /*
                 * This has to be atomic.  If the porthash is shared across
                 * multiple protocol threads (aka tcp) then the token must
                 * be held.
                 */
                porthash = in_pcbporthash_head(portinfo, lport);
                GET_PORTHASH_TOKEN(porthash);

                if (so->so_cred->cr_uid != 0 &&
                    !IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) {
                        t = in6_pcblookup_local(porthash, &sin6->sin6_addr,
                                                lport, INPLOOKUP_WILDCARD,
                                                cred);
                        if (t &&
                            (so->so_cred->cr_uid !=
                             t->inp_socket->so_cred->cr_uid)) {
                                inp->in6p_laddr = kin6addr_any;
                                error = EADDRINUSE;
                                goto done;
                        }
                }
                if (cred && cred->cr_prison &&
                    !prison_replace_wildcards(td, nam)) {
                        inp->in6p_laddr = kin6addr_any;
                        error = EADDRNOTAVAIL;
                        goto done;
                }
                t = in6_pcblookup_local(porthash, &sin6->sin6_addr, lport,
                                        wild, cred);
                if (t && (reuseport & t->inp_socket->so_options) == 0) {
                        inp->in6p_laddr = kin6addr_any;
                        error = EADDRINUSE;
                        goto done;
                }

                inp->inp_lport = lport;
                in_pcbinsporthash(porthash, inp);
                error = 0;
done:
                REL_PORTHASH_TOKEN(porthash);
                return (error);
        } else {
auto_select:
                jsin6.sin6_addr = inp->in6p_laddr;
                jsin6.sin6_family = AF_INET6;
                if (!prison_replace_wildcards(td, (struct sockaddr*)&jsin6)) {
                        inp->in6p_laddr = kin6addr_any;
                        inp->inp_lport = 0;
                        return (EINVAL);
                }

                return in6_pcbsetlport(&inp->in6p_laddr, inp, td);
        }
}

/*
 *   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 thread *td)
{
        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
        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_ifaddr) {
                /*
                 * 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 = kin6addr_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, td);
                if (*plocal_addr6 == NULL) {
                        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(struct inpcb *inp, struct sockaddr *nam, struct thread *td)
{
        struct in6_addr *addr6;
        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
        int error;

        /* Reject v4-mapped address */
        if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
                return EADDRNOTAVAIL;

        /*
         * Call inner routine, to assign local interface address.
         * in6_pcbladdr() may automatically fill in sin6_scope_id.
         */
        if ((error = in6_pcbladdr(inp, nam, &addr6, td)) != 0)
                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, NULL, td);
                        if (error)
                                return (error);
                }
                inp->in6p_laddr = *addr6;
        }
        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_pcbinsconnhash(inp);
        return (0);
}

void
in6_pcbdisconnect(struct inpcb *inp)
{
        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_pcbremconnhash(inp);
        if (inp->inp_socket->so_state & SS_NOFDREF)
                in6_pcbdetach(inp);
}

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

        inp->inp_gencnt = ++ipi->ipi_gencnt;
        in_pcbremlists(inp);
        so->so_pcb = NULL;
        KKASSERT((so->so_state & SS_ASSERTINPROG) == 0);
        sofree(so);             /* remove pcb ref */

        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)
                m_free(inp->inp_options);
        ip_freemoptions(inp->inp_moptions);

        kfree(inp, M_PCB);
}

/*
 * The socket may have an invalid PCB, i.e. NULL.  For example, a TCP
 * socket received RST.
 */
static int
in6_setsockaddr(struct socket *so, struct sockaddr **nam)
{
        struct inpcb *inp;
        struct sockaddr_in6 *sin6;

        KASSERT(curthread->td_type == TD_TYPE_NETISR, ("not in netisr"));
        inp = so->so_pcb;
        if (!inp)
                return EINVAL;

        sin6 = kmalloc(sizeof *sin6, M_SONAME, M_WAITOK | M_ZERO);
        sin6->sin6_family = AF_INET6;
        sin6->sin6_len = sizeof(*sin6);
        sin6->sin6_port = inp->inp_lport;
        sin6->sin6_addr = inp->in6p_laddr;
        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;
}

void
in6_setsockaddr_dispatch(netmsg_t msg)
{
        int error;

        error = in6_setsockaddr(msg->sockaddr.base.nm_so, msg->sockaddr.nm_nam);
        lwkt_replymsg(&msg->sockaddr.base.lmsg, error);
}

void
in6_setpeeraddr_dispatch(netmsg_t msg)
{
        int error;

        error = in6_setpeeraddr(msg->peeraddr.base.nm_so, msg->peeraddr.nm_nam);
        lwkt_replymsg(&msg->peeraddr.base.lmsg, error);
}

/*
 * The socket may have an invalid PCB, i.e. NULL.  For example, a TCP
 * socket received RST.
 */
int
in6_setpeeraddr(struct socket *so, struct sockaddr **nam)
{
        struct inpcb *inp;
        struct sockaddr_in6 *sin6;

        KASSERT(curthread->td_type == TD_TYPE_NETISR, ("not in netisr"));
        inp = so->so_pcb;
        if (!inp)
                return EINVAL;

        sin6 = kmalloc(sizeof(*sin6), M_SONAME, M_WAITOK | M_ZERO);
        sin6->sin6_family = AF_INET6;
        sin6->sin6_len = sizeof(struct sockaddr_in6);
        sin6->sin6_port = inp->inp_fport;
        sin6->sin6_addr = inp->in6p_faddr;
        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;
}

/*
 * Pass some notification to all connections of a protocol
 * associated with address dst.  The local address and/or port numbers
 * may be specified to limit the search.  The "usual action" will be
 * taken, depending on the ctlinput cmd.  The caller must filter any
 * cmds that are uninteresting (e.g., no error in the map).
 * Call the protocol specific routine (if any) to report
 * any errors for each matching socket.
 */
void
in6_pcbnotify(struct inpcbinfo *pcbinfo, struct sockaddr *dst, in_port_t fport,
    const struct sockaddr *src, in_port_t lport, int cmd, int arg,
    inp_notify_t notify)
{
        struct inpcb *inp, *marker;
        struct sockaddr_in6 sa6_src, *sa6_dst;
        u_int32_t flowinfo;

        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;
        }
        if (cmd != PRC_MSGSIZE)
                arg = inet6ctlerrmap[cmd];

        marker = in_pcbmarker();

        GET_PCBINFO_TOKEN(pcbinfo);

        LIST_INSERT_HEAD(&pcbinfo->pcblisthead, marker, inp_list);
        while ((inp = LIST_NEXT(marker, inp_list)) != NULL) {
                LIST_REMOVE(marker, inp_list);
                LIST_INSERT_AFTER(inp, marker, inp_list);

                if (inp->inp_flags & INP_PLACEMARKER)
                        continue;

                if (!INP_ISIPV6(inp))
                        continue;
                /*
                 * If the error designates a new path MTU for a destination
                 * and the application (associated with this socket) wanted to
                 * know the value, notify. Note that we notify for all
                 * disconnected sockets if the corresponding application
                 * wanted. This is because some UDP applications keep sending
                 * sockets disconnected.
                 * XXX: should we avoid to notify the value to TCP sockets?
                 */
                if (cmd == PRC_MSGSIZE && (inp->inp_flags & IN6P_MTU) != 0 &&
                    (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) ||
                     IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &sa6_dst->sin6_addr))) {
                        ip6_notify_pmtu(inp, (struct sockaddr_in6 *)dst, &arg);
                }

                /*
                 * 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)
                        (*notify)(inp, arg);
        }
        LIST_REMOVE(marker, inp_list);

        REL_PCBINFO_TOKEN(pcbinfo);
}

/*
 * Lookup a PCB based on the local address and port.
 */
struct inpcb *
in6_pcblookup_local(struct inpcbporthead *porthash,
    const struct in6_addr *laddr, u_int lport_arg, int wild_okay,
    struct ucred *cred)
{
        struct prison *pscan;
        struct prison *pr;
        struct inpcb *inp;
        int matchwild = 3, wildcard;
        u_short lport = lport_arg;
        struct inpcbport *phd;
        struct inpcb *match = NULL;

        /*
         * If the porthashbase is shared across several cpus, it must
         * have been locked.
         */
        ASSERT_PORTHASH_TOKEN_HELD(porthash);

        /*
         * Best fit PCB lookup.
         *
         * First see if this local port is in use by looking on the
         * port hash list.
         */
        LIST_FOREACH(phd, porthash, phd_hash) {
                if (phd->phd_port == lport)
                        break;
        }

        if (phd != NULL) {
                pr = cred ? cred->cr_prison : 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_ISIPV6(inp))
                                continue;
                        if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
                                wildcard++;

                        if (inp->inp_socket && inp->inp_socket->so_cred)
                                pscan = inp->inp_socket->so_cred->cr_prison;
                        else
                                pscan = NULL;
                        if (pr != pscan)
                                continue;

                        if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
                                if (!IN6_IS_ADDR_UNSPECIFIED(laddr))
                                        wildcard++;
                        } else {
                                if (IN6_IS_ADDR_UNSPECIFIED(laddr))
                                        wildcard++;
                                else if (!IN6_ARE_ADDR_EQUAL(
                                                    &inp->in6p_laddr, laddr))
                                        continue;
                        }
                        if (wildcard && !wild_okay)
                                continue;
                        if (wildcard < matchwild) {
                                match = inp;
                                matchwild = wildcard;
                                if (wildcard == 0)
                                        break;
                        }
                }
        }
        return (match);
}

void
in6_pcbpurgeif0(struct inpcbinfo *pcbinfo, struct ifnet *ifp)
{
        struct in6pcb *in6p, *marker;
        struct ip6_moptions *im6o;
        struct in6_multi_mship *imm, *nimm;

        /*
         * We only need to make sure that we are in netisr0, where all
         * multicast operation happen.  We could check inpcbinfo which
         * does not belong to netisr0 by holding the inpcbinfo's token.
         * In this case, the pcbinfo must be able to be shared, i.e.
         * pcbinfo->infotoken is not NULL.
         */
        ASSERT_NETISR0;
        KASSERT(pcbinfo->cpu == 0 || pcbinfo->infotoken != NULL,
            ("pcbinfo could not be shared"));

        /*
         * Get a marker for the current netisr (netisr0).
         *
         * It is possible that the multicast address deletion blocks,
         * which could cause temporary token releasing.  So we use
         * inpcb marker here to get a coherent view of the inpcb list.
         *
         * While, on the other hand, moptions are only added and deleted
         * in netisr0, so we would not see staled moption or miss moption
         * even if the token was released due to the blocking multicast
         * address deletion.
         */
        marker = in_pcbmarker();

        GET_PCBINFO_TOKEN(pcbinfo);

        LIST_INSERT_HEAD(&pcbinfo->pcblisthead, marker, inp_list);
        while ((in6p = LIST_NEXT(marker, inp_list)) != NULL) {
                LIST_REMOVE(marker, inp_list);
                LIST_INSERT_AFTER(in6p, marker, inp_list);

                if (in6p->in6p_flags & INP_PLACEMARKER)
                        continue;
                im6o = in6p->in6p_moptions;
                if (INP_ISIPV6(in6p) && 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);
                                        kfree(imm, M_IPMADDR);
                                }
                        }
                }
        }
        LIST_REMOVE(marker, inp_list);

        REL_PCBINFO_TOKEN(pcbinfo);
}

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

        if ((rt = in6p->in6p_route.ro_rt) != NULL) {
                bzero((caddr_t)&info, sizeof(info));
                info.rti_flags = rt->rt_flags;
                info.rti_info[RTAX_DST] = rt_key(rt);
                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) {
                        rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway,
                            rt_mask(rt), rt->rt_flags, NULL);
                }
                in6p->in6p_route.ro_rt = NULL;
                rtfree(rt);
                /*
                 * A new route can be allocated
                 * the next time output is attempted.
                 */
        }
}

/*
 * After a routing change, flush old routing
 * and allocate a (hopefully) better one.
 */
void
in6_rtchange(struct inpcb *inp, int error)
{
        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, struct ifnet *ifp)
{
        struct inpcbhead *head;
        struct inpcb *inp;
        struct inpcb *jinp = NULL;
        u_short fport = fport_arg, lport = lport_arg;

        /*
         * First look for an exact match.
         */
        head = &pcbinfo->hashbase[INP_PCBCONNHASH(faddr->s6_addr32[3] /* XXX */,
                                              fport,
                                              laddr->s6_addr32[3], /* XXX JH */
                                              lport,
                                              pcbinfo->hashmask)];
        LIST_FOREACH(inp, head, inp_hash) {
                if (!INP_ISIPV6(inp))
                        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.
                         */
                        if (inp->inp_socket == NULL ||
                            inp->inp_socket->so_cred->cr_prison == NULL) {
                                return (inp);
                        }
                        if  (jinp == NULL)
                                jinp = inp;
                }
        }
        if (jinp != NULL)
                return(jinp);

        if (wildcard) {
                struct inpcb *local_wild = NULL;
                struct inpcb *jinp_wild = NULL;
                struct inpcontainer *ic;
                struct inpcontainerhead *chead;
                struct sockaddr_in6 jsin6;
                struct ucred *cred;
                struct prison *pr;
                int net_listen_ov_local = 0;
                int net_listen_ov_wild = 0;

                /*
                 * Order of socket selection:
                 * 1. non-jailed, non-wild.
                 * 2. non-jailed, wild.         (allow_listen_override on)
                 * 3. jailed, non-wild.
                 * 4. jailed, wild.
                 * 5. non-jailed, wild.         (allow_listen_override off)
                 *
                 * NOTE: jailed wildcards are still restricted to the jail
                 *       IPs.
                 *
                 * NOTE: (1) and (3) already handled above.
                 */
                jsin6.sin6_family = AF_INET6;
                chead = &pcbinfo->wildcardhashbase[INP_PCBWILDCARDHASH(lport,
                    pcbinfo->wildcardhashmask)];

                GET_PCBINFO_TOKEN(pcbinfo);
                LIST_FOREACH(ic, chead, ic_list) {
                        inp = ic->ic_inp;
                        if (inp->inp_flags & INP_PLACEMARKER)
                                continue;

                        /*
                         * Basdic validation
                         */
                        if (!INP_ISIPV6(inp))
                                continue;
                        if (inp->inp_lport != lport)
                                continue;

                        /*
                         * Calculate prison, setup jsin for jailed_ip()
                         * check.
                         */
                        jsin6.sin6_addr = *laddr;
                        pr = NULL;
                        cred = NULL;
                        if (inp->inp_socket) {
                                cred = inp->inp_socket->so_cred;
                                if (cred)
                                        pr = cred->cr_prison;
                        }

                        /*
                         * Assign jinp, jinp_wild, and local_wild as
                         * appropriate, track whether the jail supports
                         * listen overrides.
                         */
                        if (pr) {
                                if (!jailed_ip(pr, (struct sockaddr *)&jsin6))
                                        continue;
                                if (IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, laddr)
                                    && jinp == NULL) {
                                        jinp = inp;
                                        if (PRISON_CAP_ISSET(pr->pr_caps, PRISON_CAP_NET_LISTEN_OVERRIDE))
                                                net_listen_ov_local = 1;
                                }
                                if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) &&
                                    jinp_wild == NULL) {
                                        jinp_wild = inp;
                                        if (PRISON_CAP_ISSET(pr->pr_caps, PRISON_CAP_NET_LISTEN_OVERRIDE))
                                                net_listen_ov_wild = 1;
                                }
                        } else {
                                if (IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, laddr)) {
                                        REL_PCBINFO_TOKEN(pcbinfo);
                                        return (inp);
                                }
                                if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
                                        local_wild = inp;
                        }
                }
                REL_PCBINFO_TOKEN(pcbinfo);

                if (net_listen_ov_local)
                        return jinp;
                if (net_listen_ov_wild)
                        return jinp_wild;
                if (local_wild)
                        return local_wild;
                if (jinp)
                        return jinp;
                return (jinp_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;
}

void
in6_savefaddr(struct socket *so, const struct sockaddr *faddr)
{
        struct sockaddr_in6 *sin6;

        KASSERT(faddr->sa_family == AF_INET6,
            ("not AF_INET6 faddr %d", faddr->sa_family));

        sin6 = kmalloc(sizeof(*sin6), M_SONAME, M_WAITOK | M_ZERO);
        sin6->sin6_family = AF_INET6;
        sin6->sin6_len = sizeof(*sin6);

        sin6->sin6_port = ((const struct sockaddr_in6 *)faddr)->sin6_port;
        sin6->sin6_addr = ((const struct sockaddr_in6 *)faddr)->sin6_addr;

        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;

        so->so_faddr = (struct sockaddr *)sin6;
}