/*      $FreeBSD: src/sys/netinet6/udp6_usrreq.c,v 1.6.2.13 2003/01/24 05:11:35 sam Exp $       */
/*      $KAME: udp6_usrreq.c,v 1.27 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, 1989, 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.
 *
 *      @(#)udp_var.h   8.1 (Berkeley) 6/10/93
 */

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

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/errno.h>
#include <sys/stat.h>
#include <sys/systm.h>
#include <sys/syslog.h>
#include <sys/proc.h>
#include <sys/caps.h>
#include <sys/jail.h>

#include <sys/thread2.h>
#include <sys/socketvar2.h>
#include <sys/msgport2.h>

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

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_pcb.h>
#include <netinet/icmp6.h>
#include <netinet6/udp6_var.h>
#include <netinet6/ip6protosw.h>

/*
 * UDP protocol inplementation.
 * Per RFC 768, August, 1980.
 */

extern  struct protosw inetsw[];
static  int in6_mcmatch (struct inpcb *, struct in6_addr *, struct ifnet *);

static int
in6_mcmatch(struct inpcb *in6p, struct in6_addr *ia6, struct ifnet *ifp)
{
        struct ip6_moptions *im6o = in6p->in6p_moptions;
        struct in6_multi_mship *imm;

        if (im6o == NULL)
                return 0;

        for (imm = im6o->im6o_memberships.lh_first; imm != NULL;
             imm = imm->i6mm_chain.le_next) {
                if ((ifp == NULL ||
                     imm->i6mm_maddr->in6m_ifp == ifp) &&
                    IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
                                       ia6))
                        return 1;
        }
        return 0;
}

int
udp6_input(struct mbuf **mp, int *offp, int proto)
{
        struct mbuf *m = *mp;
        struct ip6_hdr *ip6;
        struct udphdr *uh;
        struct inpcb *in6p;
        struct  mbuf *opts = NULL;
        int off = *offp;
        int plen, ulen;
        struct sockaddr_in6 udp_in6;
        struct socket *so;
        struct inpcbinfo *pcbinfo = &udbinfo[0];

        IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);

        ip6 = mtod(m, struct ip6_hdr *);

        udp_stat.udps_ipackets++;

        plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
        uh = (struct udphdr *)((caddr_t)ip6 + off);
        ulen = ntohs((u_short)uh->uh_ulen);

        if (plen != ulen) {
                udp_stat.udps_badlen++;
                goto bad;
        }

        /*
         * Checksum extended UDP header and data.
         */
        if (uh->uh_sum == 0)
                udp_stat.udps_nosum++;
        else if (in6_cksum(m, IPPROTO_UDP, off, ulen) != 0) {
                udp_stat.udps_badsum++;
                goto bad;
        }

        if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
                struct  inpcb *last, *marker;

                /*
                 * Deliver a multicast datagram to all sockets
                 * for which the local and remote addresses and ports match
                 * those of the incoming datagram.  This allows more than
                 * one process to receive multicasts on the same port.
                 * (This really ought to be done for unicast datagrams as
                 * well, but that would cause problems with existing
                 * applications that open both address-specific sockets and
                 * a wildcard socket listening to the same port -- they would
                 * end up receiving duplicates of every unicast datagram.
                 * Those applications open the multiple sockets to overcome an
                 * inadequacy of the UDP socket interface, but for backwards
                 * compatibility we avoid the problem here rather than
                 * fixing the interface.  Maybe 4.5BSD will remedy this?)
                 */

                /*
                 * In a case that laddr should be set to the link-local
                 * address (this happens in RIPng), the multicast address
                 * specified in the received packet does not match with
                 * laddr. To cure this situation, the matching is relaxed
                 * if the receiving interface is the same as one specified
                 * in the socket and if the destination multicast address
                 * matches one of the multicast groups specified in the socket.
                 */

                /*
                 * Construct sockaddr format source address.
                 */
                init_sin6(&udp_in6, m); /* general init */
                udp_in6.sin6_port = uh->uh_sport;
                /*
                 * KAME note: traditionally we dropped udpiphdr from mbuf here.
                 */

                /*
                 * Locate pcb(s) for datagram.
                 * (Algorithm copied from raw_intr().)
                 */
                last = NULL;

                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->inp_flags & INP_PLACEMARKER)
                                continue;
                        if (!INP_ISIPV6(in6p))
                                continue;
                        if (in6p->in6p_lport != uh->uh_dport)
                                continue;
                        if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
                                if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr,
                                                        &ip6->ip6_dst) &&
                                    !in6_mcmatch(in6p, &ip6->ip6_dst,
                                                 m->m_pkthdr.rcvif))
                                        continue;
                        }
                        if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
                                if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr,
                                                        &ip6->ip6_src) ||
                                   in6p->in6p_fport != uh->uh_sport)
                                        continue;
                        }

                        if (last != NULL) {
                                struct mbuf *n;

                                n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
                                if (n != NULL) {
                                        /*
                                         * KAME NOTE: do not
                                         * m_copym(m, offset, ...) above.
                                         * ssb_appendaddr() expects M_PKTHDR,
                                         * and m_copym() will copy M_PKTHDR
                                         * only if offset is 0.
                                         */
                                        so = last->in6p_socket;
                                        if ((last->in6p_flags & IN6P_CONTROLOPTS) ||
                                            (so->so_options & SO_TIMESTAMP)) {
                                                ip6_savecontrol(last, &opts,
                                                                ip6, n);
                                        }
                                        m_adj(n, off + sizeof(struct udphdr));
                                        lwkt_gettoken(&so->so_rcv.ssb_token);
                                        if (ssb_appendaddr(&so->so_rcv,
                                                    (struct sockaddr *)&udp_in6,
                                                    n, opts) == 0) {
                                                m_freem(n);
                                                if (opts)
                                                        m_freem(opts);
                                                udp_stat.udps_fullsock++;
                                                soroverflow(so);
                                        } else {
                                                sorwakeup(so);
                                        }
                                        lwkt_reltoken(&so->so_rcv.ssb_token);
                                        opts = NULL;
                                }
                        }
                        last = in6p;
                        /*
                         * Don't look for additional matches if this one does
                         * not have either the SO_REUSEPORT or SO_REUSEADDR
                         * socket options set.  This heuristic avoids searching
                         * through all pcbs in the common case of a non-shared
                         * port.  It assumes that an application will never
                         * clear these options after setting them.
                         */
                        if ((last->in6p_socket->so_options &
                             (SO_REUSEPORT | SO_REUSEADDR)) == 0)
                                break;
                }
                LIST_REMOVE(marker, inp_list);

                REL_PCBINFO_TOKEN(pcbinfo);

                if (last == NULL) {
                        /*
                         * No matching pcb found; discard datagram.
                         * (No need to send an ICMP Port Unreachable
                         * for a broadcast or multicast datgram.)
                         */
                        udp_stat.udps_noport++;
                        udp_stat.udps_noportmcast++;
                        goto bad;
                }
                if (last->in6p_flags & IN6P_CONTROLOPTS
                    || last->in6p_socket->so_options & SO_TIMESTAMP)
                        ip6_savecontrol(last, &opts, ip6, m);

                m_adj(m, off + sizeof(struct udphdr));
                so = last->in6p_socket;
                lwkt_gettoken(&so->so_rcv.ssb_token);
                if (ssb_appendaddr(&so->so_rcv, (struct sockaddr *)&udp_in6,
                                   m, opts) == 0) {
                        udp_stat.udps_fullsock++;
                        soroverflow(so);
                        lwkt_reltoken(&so->so_rcv.ssb_token);
                        goto bad;
                }
                sorwakeup(so);
                lwkt_reltoken(&so->so_rcv.ssb_token);
                return IPPROTO_DONE;
        }
        /*
         * Locate pcb for datagram.
         */
        in6p = in6_pcblookup_hash(pcbinfo, &ip6->ip6_src, uh->uh_sport,
                                  &ip6->ip6_dst, uh->uh_dport, 1,
                                  m->m_pkthdr.rcvif);
        if (in6p == NULL) {
                if (log_in_vain) {
                        char buf[INET6_ADDRSTRLEN];

                        strcpy(buf, ip6_sprintf(&ip6->ip6_dst));
                        log(LOG_INFO,
                            "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
                            buf, ntohs(uh->uh_dport),
                            ip6_sprintf(&ip6->ip6_src), ntohs(uh->uh_sport));
                }
                udp_stat.udps_noport++;
                if (m->m_flags & M_MCAST) {
                        kprintf("UDP6: M_MCAST is set in a unicast packet.\n");
                        udp_stat.udps_noportmcast++;
                        goto bad;
                }
                icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
                return IPPROTO_DONE;
        }

        /*
         * Construct sockaddr format source address.
         * Stuff source address and datagram in user buffer.
         */
        init_sin6(&udp_in6, m); /* general init */
        udp_in6.sin6_port = uh->uh_sport;
        if (in6p->in6p_flags & IN6P_CONTROLOPTS
            || in6p->in6p_socket->so_options & SO_TIMESTAMP)
                ip6_savecontrol(in6p, &opts, ip6, m);
        m_adj(m, off + sizeof(struct udphdr));
        so = in6p->in6p_socket;
        lwkt_gettoken(&so->so_rcv.ssb_token);
        if (ssb_appendaddr(&so->so_rcv, (struct sockaddr *)&udp_in6,
                           m, opts) == 0) {
                udp_stat.udps_fullsock++;
                soroverflow(so);
                lwkt_reltoken(&so->so_rcv.ssb_token);
                goto bad;
        }
        sorwakeup(so);
        lwkt_reltoken(&so->so_rcv.ssb_token);
        return IPPROTO_DONE;
bad:
        if (m)
                m_freem(m);
        if (opts)
                m_freem(opts);
        return IPPROTO_DONE;
}

void
udp6_ctlinput(netmsg_t msg)
{
        int cmd = msg->ctlinput.nm_cmd;
        struct sockaddr *sa = msg->ctlinput.nm_arg;
        void *d = msg->ctlinput.nm_extra;
        struct udphdr uh;
        struct ip6_hdr *ip6;
        struct mbuf *m;
        int off = 0;
        struct ip6ctlparam *ip6cp = NULL;
        const struct sockaddr_in6 *sa6_src = NULL;
        inp_notify_t notify = udp_notify;
        struct udp_portonly {
                u_int16_t uh_sport;
                u_int16_t uh_dport;
        } *uhp;

        if (sa->sa_family != AF_INET6 ||
            sa->sa_len != sizeof(struct sockaddr_in6))
                goto out;

        if ((unsigned)cmd >= PRC_NCMDS)
                goto out;
        if (PRC_IS_REDIRECT(cmd))
                notify = in6_rtchange, d = NULL;
        else if (cmd == PRC_HOSTDEAD)
                d = NULL;
        else if (inet6ctlerrmap[cmd] == 0)
                goto out;

        /* if the parameter is from icmp6, decode it. */
        if (d != NULL) {
                ip6cp = (struct ip6ctlparam *)d;
                m = ip6cp->ip6c_m;
                ip6 = ip6cp->ip6c_ip6;
                off = ip6cp->ip6c_off;
                sa6_src = ip6cp->ip6c_src;
        } else {
                m = NULL;
                ip6 = NULL;
                sa6_src = &sa6_any;
        }

        if (ip6) {
                /*
                 * XXX: We assume that when IPV6 is non NULL,
                 * M and OFF are valid.
                 */

                /* check if we can safely examine src and dst ports */
                if (m->m_pkthdr.len < off + sizeof(*uhp))
                        return;

                bzero(&uh, sizeof(uh));
                m_copydata(m, off, sizeof(*uhp), &uh);

                in6_pcbnotify(&udbinfo[0], sa, uh.uh_dport,
                              (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport,
                              cmd, 0, notify);
        } else {
                in6_pcbnotify(&udbinfo[0], sa, 0,
                              (const struct sockaddr *)sa6_src, 0,
                              cmd, 0, notify);
        }
out:
        lwkt_replymsg(&msg->ctlinput.base.lmsg, 0);
}

static int
udp6_getcred(SYSCTL_HANDLER_ARGS)
{
        struct sockaddr_in6 addrs[2];
        struct inpcb *inp;
        int error;

        error = caps_priv_check_td(req->td, SYSCAP_RESTRICTEDROOT);
        if (error)
                return (error);

        if (req->newlen != sizeof(addrs))
                return (EINVAL);
        if (req->oldlen != sizeof(struct ucred))
                return (EINVAL);
        error = SYSCTL_IN(req, addrs, sizeof(addrs));
        if (error)
                return (error);
        crit_enter();
        inp = in6_pcblookup_hash(&udbinfo[0], &addrs[1].sin6_addr,
                                 addrs[1].sin6_port,
                                 &addrs[0].sin6_addr, addrs[0].sin6_port,
                                 1, NULL);
        if (!inp || !inp->inp_socket) {
                error = ENOENT;
                goto out;
        }
        error = SYSCTL_OUT(req, inp->inp_socket->so_cred,
                           sizeof(struct ucred));

out:
        crit_exit();
        return (error);
}

SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW,
            0, 0,
            udp6_getcred, "S,ucred", "Get the ucred of a UDP6 connection");

/*
 * NOTE: (so) is referenced from soabort*() and netmsg_pru_abort()
 *       will sofree() it when we return.
 */
static void
udp6_abort(netmsg_t msg)
{
        struct socket *so = msg->abort.base.nm_so;
        struct inpcb *inp;
        int error;

        inp = so->so_pcb;
        if (inp) {
                soisdisconnected(so);

                in6_pcbdetach(inp);
                error = 0;
        } else {
                error = EINVAL;
        }
        lwkt_replymsg(&msg->abort.base.lmsg, error);
}

static void
udp6_attach(netmsg_t msg)
{
        struct socket *so = msg->attach.base.nm_so;
        struct pru_attach_info *ai = msg->attach.nm_ai;
        struct inpcb *inp;
        int error;

        inp = so->so_pcb;
        if (inp != NULL) {
                error = EINVAL;
                goto out;
        }

        if (so->so_snd.ssb_hiwat == 0 || so->so_rcv.ssb_hiwat == 0) {
                error = soreserve(so, udp_sendspace, udp_recvspace,
                    ai->sb_rlimit);
                if (error)
                        goto out;
        }

        error = in_pcballoc(so, &udbinfo[0]);
        if (error)
                goto out;

        inp = (struct inpcb *)so->so_pcb;
        inp->in6p_hops = -1;    /* use kernel default */
        inp->in6p_cksum = -1;   /* just to be sure */
        /*
         * XXX: ugly!!
         * IPv4 TTL initialization is necessary for an IPv6 socket as well,
         * because the socket may be bound to an IPv6 wildcard address,
         * which may match an IPv4-mapped IPv6 address.
         */
        inp->inp_ip_ttl = ip_defttl;
        error = 0;
out:
        lwkt_replymsg(&msg->attach.base.lmsg, error);
}

static void
udp6_bind(netmsg_t msg)
{
        struct socket *so =msg->bind.base.nm_so;
        struct sockaddr *nam = msg->bind.nm_nam;
        struct thread *td = msg->bind.nm_td;
        struct sockaddr_in6 *sin6_p = (struct sockaddr_in6 *)nam;
        struct inpcb *inp;
        int error;

        inp = so->so_pcb;
        if (inp == NULL) {
                error = EINVAL;
                goto out;
        }

        error = in6_pcbbind(inp, nam, td);
        if (error == 0) {
                if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
                        inp->inp_flags |= INP_WASBOUND_NOTANY;
                in_pcbinswildcardhash(inp);
        }
out:
        lwkt_replymsg(&msg->bind.base.lmsg, error);
}

static void
udp6_connect(netmsg_t msg)
{
        struct socket *so = msg->connect.base.nm_so;
        struct sockaddr *nam = msg->connect.nm_nam;
        struct thread *td = msg->connect.nm_td;
        struct sockaddr_in6 *sin6_p;
        struct inpcb *inp;
        int error;

        inp = so->so_pcb;
        if (inp == NULL) {
                error = EINVAL;
                goto out;
        }

        sin6_p = (struct sockaddr_in6 *)nam;
        if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
                error = EADDRNOTAVAIL;
                goto out;
        }

        if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
                error = EISCONN;
                goto out;
        }
        if (inp->inp_flags & INP_WILDCARD)
                in_pcbremwildcardhash(inp);
        error = in6_pcbconnect(inp, nam, td);
        if (error == 0) {
                soisconnected(so);
        } else if (error == EAFNOSUPPORT) {     /* connection dissolved */
                /*
                 * Follow traditional BSD behavior and retain
                 * the local port binding.  But, fix the old misbehavior
                 * of overwriting any previously bound local address.
                 */
                if (!(inp->inp_flags & INP_WASBOUND_NOTANY))
                        inp->in6p_laddr = kin6addr_any;
                in_pcbinswildcardhash(inp);
        }
out:
        lwkt_replymsg(&msg->connect.base.lmsg, error);
}

static void
udp6_detach(netmsg_t msg)
{
        struct socket *so = msg->detach.base.nm_so;
        struct inpcb *inp;
        int error;

        inp = so->so_pcb;
        if (inp) {
                in6_pcbdetach(inp);
                error = 0;
        } else {
                error = EINVAL;
        }
        lwkt_replymsg(&msg->detach.base.lmsg, error);
}

static void
udp6_disconnect(netmsg_t msg)
{
        struct socket *so = msg->disconnect.base.nm_so;
        struct inpcb *inp;
        int error;

        inp = so->so_pcb;
        if (inp == NULL) {
                error = EINVAL;
                goto out;
        }

        if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
                error = ENOTCONN;
        } else {
                in6_pcbdisconnect(inp);
                soclrstate(so, SS_ISCONNECTED);         /* XXX */
                error = 0;
        }
out:
        lwkt_replymsg(&msg->disconnect.base.lmsg, error);
}

static void
udp6_send(netmsg_t msg)
{
        struct socket *so = msg->send.base.nm_so;
        struct mbuf *m = msg->send.nm_m;
        struct sockaddr *addr = msg->send.nm_addr;
        struct mbuf *control = msg->send.nm_control;
        struct thread *td = msg->send.nm_td;
        struct inpcb *inp;
        int error = 0;

        inp = so->so_pcb;
        if (inp == NULL) {
                error = EINVAL;
                goto bad;
        }

        if (addr) {
                struct sockaddr_in6 *sin6;

                if (addr->sa_len != sizeof(struct sockaddr_in6)) {
                        error = EINVAL;
                        goto bad;
                }
                if (addr->sa_family != AF_INET6) {
                        error = EAFNOSUPPORT;
                        goto bad;
                }

                sin6 = (struct sockaddr_in6 *)addr;
                if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
                        error = EADDRNOTAVAIL;
                        goto bad;
                }
        }

        error = udp6_output(inp, m, addr, control, td);
        lwkt_replymsg(&msg->send.base.lmsg, error);
        return;
bad:
        m_freem(m);
        lwkt_replymsg(&msg->send.base.lmsg, error);
}

struct pr_usrreqs udp6_usrreqs = {
        .pru_abort = udp6_abort,
        .pru_accept = pr_generic_notsupp,
        .pru_attach = udp6_attach,
        .pru_bind = udp6_bind,
        .pru_connect = udp6_connect,
        .pru_connect2 = pr_generic_notsupp,
        .pru_control = in6_control_dispatch,
        .pru_detach = udp6_detach,
        .pru_disconnect = udp6_disconnect,
        .pru_listen = pr_generic_notsupp,
        .pru_peeraddr = in6_setpeeraddr_dispatch,
        .pru_rcvd = pr_generic_notsupp,
        .pru_rcvoob = pr_generic_notsupp,
        .pru_send = udp6_send,
        .pru_sense = pru_sense_null,
        .pru_shutdown = udp_shutdown,
        .pru_sockaddr = in6_setsockaddr_dispatch,
        .pru_sosend = sosend,
        .pru_soreceive = soreceive
};