/*
 * 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.
 *
 * $FreeBSD: src/sys/net/if_gif.c,v 1.4.2.15 2002/11/08 16:57:13 ume Exp $
 * $KAME: if_gif.c,v 1.87 2001/10/19 08:50:27 itojun Exp $
 */

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

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/protosw.h>
#include <sys/conf.h>
#include <sys/thread2.h>

#include <machine/cpu.h>

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

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#ifdef  INET
#include <netinet/in_var.h>
#include <netinet/in_gif.h>
#include <netinet/ip_var.h>
#endif  /* INET */

#ifdef INET6
#ifndef INET
#include <netinet/in.h>
#endif
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_gif.h>
#include <netinet6/ip6protosw.h>
#endif /* INET6 */

#include <netinet/ip_encap.h>
#include "if_gif.h"

#include <net/net_osdep.h>

#define GIFNAME         "gif"

#define MTAG_GIF        1709048582 /* mtag cookie for nesting check */

static MALLOC_DEFINE(M_GIF, "gif", "Generic Tunnel Interface");
LIST_HEAD(, gif_softc) gif_softc_list;

int     gif_clone_create(struct if_clone *, int, caddr_t, caddr_t);
int     gif_clone_destroy(struct ifnet *);

struct if_clone gif_cloner = IF_CLONE_INITIALIZER("gif", gif_clone_create,
    gif_clone_destroy, 0, IF_MAXUNIT);

static int gifmodevent(module_t, int, void *);
static void gif_clear_cache(struct gif_softc *sc);

SYSCTL_DECL(_net_link);
SYSCTL_NODE(_net_link, IFT_GIF, gif, CTLFLAG_RW, 0,
    "Generic Tunnel Interface");

#ifndef MAX_GIF_NEST
/*
 * This macro controls the default upper limitation on nesting of gif tunnels.
 * Since, setting a large value to this macro with a careless configuration
 * may introduce system crash, we don't allow any nestings by default.
 * If you need to configure nested gif tunnels, you can define this macro
 * in your kernel configuration file.  However, if you do so, please be
 * careful to configure the tunnels so that it won't make a loop.
 */
#define MAX_GIF_NEST 1
#endif
static int max_gif_nesting = MAX_GIF_NEST;
SYSCTL_INT(_net_link_gif, OID_AUTO, max_nesting, CTLFLAG_RW,
    &max_gif_nesting, 0, "Max nested tunnels");

/*
 * By default, we disallow creation of multiple tunnels between the same
 * pair of addresses.  Some applications require this functionality so
 * we allow control over this check here.
 */
#ifdef XBONEHACK
static int parallel_tunnels = 1;
#else
static int parallel_tunnels = 0;
#endif
SYSCTL_INT(_net_link_gif, OID_AUTO, parallel_tunnels, CTLFLAG_RW,
    &parallel_tunnels, 0, "Allow parallel tunnels?");


int
gif_clone_create(struct if_clone *ifc, int unit,
                 caddr_t params __unused, caddr_t data __unused)
{
        struct gif_softc *sc;

        sc = kmalloc (sizeof(struct gif_softc), M_GIF, M_WAITOK | M_ZERO);

        sc->gif_if.if_softc = sc;
        if_initname(&(sc->gif_if), GIFNAME, unit);

        gifattach0(sc);

        LIST_INSERT_HEAD(&gif_softc_list, sc, gif_list);
        return (0);
}

void
gifattach0(struct gif_softc *sc)
{

        sc->encap_cookie4 = sc->encap_cookie6 = NULL;

        sc->gif_if.if_addrlen = 0;
        sc->gif_if.if_mtu    = GIF_MTU;
        sc->gif_if.if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
#if 0
        /* turn off ingress filter */
        sc->gif_if.if_flags  |= IFF_LINK2;
#endif
        sc->gif_if.if_ioctl  = gif_ioctl;
        sc->gif_if.if_output = gif_output;
        sc->gif_if.if_type   = IFT_GIF;
        ifq_set_maxlen(&sc->gif_if.if_snd, IFQ_MAXLEN);
        if_attach(&sc->gif_if, NULL);
        bpfattach(&sc->gif_if, DLT_NULL, sizeof(uint32_t));
}

int
gif_clone_destroy(struct ifnet *ifp)
{
        struct gif_softc *sc = ifp->if_softc;
        int err;

        gif_delete_tunnel(&sc->gif_if);
        LIST_REMOVE(sc, gif_list);
#ifdef INET6
        if (sc->encap_cookie6 != NULL) {
                err = encap_detach(sc->encap_cookie6);
                KASSERT(err == 0, ("Unexpected error detaching encap_cookie6"));
        }
#endif
#ifdef INET
        if (sc->encap_cookie4 != NULL) {
                err = encap_detach(sc->encap_cookie4);
                KASSERT(err == 0, ("Unexpected error detaching encap_cookie4"));
        }
#endif
        gif_clear_cache(sc);

        bpfdetach(ifp);
        if_detach(ifp);

        kfree(sc, M_GIF);

        return 0;
}

static void
gif_clear_cache(struct gif_softc *sc)
{
        struct rtentry *rt;
        int n;

        for (n = 0; n < netisr_ncpus; ++n) {
                rt = sc->gif_ro[n].ro_rt;
                if (rt != NULL) {
                        KASSERT(rt->rt_cpuid == n,
                            ("inet rt for cpu%d installed on cpu%d slot",
                             rt->rt_cpuid, n));
                        rtfree_async(rt);
                        sc->gif_ro[n].ro_rt = NULL;
                }
#ifdef INET6
                rt = sc->gif_ro6[n].ro_rt;
                if (rt != NULL) {
                        KASSERT(rt->rt_cpuid == n,
                            ("inet6 rt for cpu%d installed on cpu%d slot",
                             rt->rt_cpuid, n));
                        rtfree_async(rt);
                        sc->gif_ro6[n].ro_rt = NULL;
                }
#endif
        }
}

static int
gifmodevent(module_t mod, int type, void *data)
{

        switch (type) {
        case MOD_LOAD:
                LIST_INIT(&gif_softc_list);
                if_clone_attach(&gif_cloner);

#ifdef INET6
                ip6_gif_hlim = GIF_HLIM;
#endif

                break;
        case MOD_UNLOAD:
                if_clone_detach(&gif_cloner);

                while (!LIST_EMPTY(&gif_softc_list))
                        gif_clone_destroy(&LIST_FIRST(&gif_softc_list)->gif_if);

#ifdef INET6
                ip6_gif_hlim = 0;
#endif
                break;
        }
        return 0;
}

static moduledata_t gif_mod = {
        "if_gif",
        gifmodevent,
        0
};

DECLARE_MODULE(if_gif, gif_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);

int
gif_encapcheck(const struct mbuf *m, int off, int proto, void *arg)
{
        struct ip ip;
        struct gif_softc *sc;

        sc = (struct gif_softc *)arg;
        if (sc == NULL)
                return 0;

        if ((sc->gif_if.if_flags & IFF_UP) == 0)
                return 0;

        /* no physical address */
        if (!sc->gif_psrc || !sc->gif_pdst)
                return 0;

        switch (proto) {
#ifdef INET
        case IPPROTO_IPV4:
                break;
#endif
#ifdef INET6
        case IPPROTO_IPV6:
                break;
#endif
        default:
                return 0;
        }

        /* Bail on short packets */
        if (m->m_pkthdr.len < sizeof(ip))
                return 0;

        m_copydata(m, 0, sizeof(ip), &ip);

        switch (ip.ip_v) {
#ifdef INET
        case 4:
                if (sc->gif_psrc->sa_family != AF_INET ||
                    sc->gif_pdst->sa_family != AF_INET)
                        return 0;
                return gif_encapcheck4(m, off, proto, arg);
#endif
#ifdef INET6
        case 6:
                if (m->m_pkthdr.len < sizeof(struct ip6_hdr))
                        return 0;
                if (sc->gif_psrc->sa_family != AF_INET6 ||
                    sc->gif_pdst->sa_family != AF_INET6)
                        return 0;
                return gif_encapcheck6(m, off, proto, arg);
#endif
        default:
                return 0;
        }
}

/*
 * Parameters:
 *      rt:     added in net2
 */
static int
gif_output_serialized(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
                      struct rtentry *rt)
{
        struct gif_softc *sc = (struct gif_softc *)ifp;
        int error = 0;

        error = if_tunnel_check_nesting(ifp, m, MTAG_GIF, max_gif_nesting);
        if (error != 0) {
                m_freem(m);
                goto end;
        }

        m->m_flags &= ~(M_BCAST|M_MCAST);
        if (!(ifp->if_flags & IFF_UP) ||
            sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
                m_freem(m);
                error = ENETDOWN;
                goto end;
        }

        if (ifp->if_bpf) {
                bpf_gettoken();
                if (ifp->if_bpf) {
                        /*
                         * We need to prepend the address family as
                         * a four byte field.
                         */
                        uint32_t af = dst->sa_family;

                        bpf_ptap(ifp->if_bpf, m, &af, sizeof(af));
                }
                bpf_reltoken();
        }
        IFNET_STAT_INC(ifp, opackets, 1);
        IFNET_STAT_INC(ifp, obytes, m->m_pkthdr.len);

        /* inner AF-specific encapsulation */

        /* XXX should we check if our outer source is legal? */

        /* dispatch to output logic based on outer AF */
        switch (sc->gif_psrc->sa_family) {
#ifdef INET
        case AF_INET:
                error = in_gif_output(ifp, dst->sa_family, m);
                break;
#endif
#ifdef INET6
        case AF_INET6:
                error = in6_gif_output(ifp, dst->sa_family, m);
                break;
#endif
        default:
                m_freem(m);
                error = ENETDOWN;
                goto end;
        }

  end:
        if (error)
                IFNET_STAT_INC(ifp, oerrors, 1);
        return error;
}

int
gif_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
           struct rtentry *rt)
{
        struct ifaltq_subque *ifsq = ifq_get_subq_default(&ifp->if_snd);
        int error;

        ASSERT_NETISR_NCPUS(mycpuid);

        ifsq_serialize_hw(ifsq);
        error = gif_output_serialized(ifp, m, dst, rt);
        ifsq_deserialize_hw(ifsq);
        return error;
}

void
gif_input(struct mbuf *m, int af, struct ifnet *ifp)
{
        int isr;

        if (ifp == NULL) {
                /* just in case */
                m_freem(m);
                return;
        }

        m->m_pkthdr.rcvif = ifp;

        if (ifp->if_bpf) {
                bpf_gettoken();
                if (ifp->if_bpf) {
                        /*
                         * We need to prepend the address family as
                         * a four byte field.
                         */
                        uint32_t af1 = af;

                        bpf_ptap(ifp->if_bpf, m, &af1, sizeof(af1));
                }
                bpf_reltoken();
        }

        /*
         * Put the packet to the network layer input queue according to the
         * specified address family.
         * Note: older versions of gif_input directly called network layer
         * input functions, e.g. ip6_input, here.  We changed the policy to
         * prevent too many recursive calls of such input functions, which
         * might cause kernel panic.  But the change may introduce another
         * problem; if the input queue is full, packets are discarded.
         * The kernel stack overflow really happened, and we believed
         * queue-full rarely occurs, so we changed the policy.
         */
        switch (af) {
#ifdef INET
        case AF_INET:
                isr = NETISR_IP;
                break;
#endif
#ifdef INET6
        case AF_INET6:
                isr = NETISR_IPV6;
                break;
#endif
        default:
                m_freem(m);
                return;
        }

        IFNET_STAT_INC(ifp, ipackets, 1);
        IFNET_STAT_INC(ifp, ibytes, m->m_pkthdr.len);
        m->m_flags &= ~M_HASH;
        netisr_queue(isr, m);

        return;
}

/* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
int
gif_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
{
        struct gif_softc *sc  = (struct gif_softc*)ifp;
        struct ifreq     *ifr = (struct ifreq*)data;
        int error = 0, size;
        struct sockaddr *dst, *src;
#ifdef  SIOCSIFMTU /* xxx */
        u_long mtu;
#endif

        switch (cmd) {
        case SIOCSIFADDR:
                ifp->if_flags |= IFF_UP;
                break;

        case SIOCSIFDSTADDR:
                break;

        case SIOCADDMULTI:
        case SIOCDELMULTI:
                break;

#ifdef  SIOCSIFMTU /* xxx */
        case SIOCGIFMTU:
                break;

        case SIOCSIFMTU:
                mtu = ifr->ifr_mtu;
                if (mtu < GIF_MTU_MIN || mtu > GIF_MTU_MAX)
                        return (EINVAL);
                ifp->if_mtu = mtu;
                break;
#endif /* SIOCSIFMTU */

#ifdef INET
        case SIOCSIFPHYADDR:
#endif
#ifdef INET6
        case SIOCSIFPHYADDR_IN6:
#endif /* INET6 */
        case SIOCSLIFPHYADDR:
                switch (cmd) {
#ifdef INET
                case SIOCSIFPHYADDR:
                        src = (struct sockaddr *)
                                &(((struct in_aliasreq *)data)->ifra_addr);
                        dst = (struct sockaddr *)
                                &(((struct in_aliasreq *)data)->ifra_dstaddr);
                        break;
#endif
#ifdef INET6
                case SIOCSIFPHYADDR_IN6:
                        src = (struct sockaddr *)
                                &(((struct in6_aliasreq *)data)->ifra_addr);
                        dst = (struct sockaddr *)
                                &(((struct in6_aliasreq *)data)->ifra_dstaddr);
                        break;
#endif
                case SIOCSLIFPHYADDR:
                        src = (struct sockaddr *)
                                &(((struct if_laddrreq *)data)->addr);
                        dst = (struct sockaddr *)
                                &(((struct if_laddrreq *)data)->dstaddr);
                        break;
                default:
                        return EINVAL;
                }

                /* sa_family must be equal */
                if (src->sa_family != dst->sa_family)
                        return EINVAL;

                /* validate sa_len */
                switch (src->sa_family) {
#ifdef INET
                case AF_INET:
                        if (src->sa_len != sizeof(struct sockaddr_in))
                                return EINVAL;
                        break;
#endif
#ifdef INET6
                case AF_INET6:
                        if (src->sa_len != sizeof(struct sockaddr_in6))
                                return EINVAL;
                        break;
#endif
                default:
                        return EAFNOSUPPORT;
                }
                switch (dst->sa_family) {
#ifdef INET
                case AF_INET:
                        if (dst->sa_len != sizeof(struct sockaddr_in))
                                return EINVAL;
                        break;
#endif
#ifdef INET6
                case AF_INET6:
                        if (dst->sa_len != sizeof(struct sockaddr_in6))
                                return EINVAL;
                        break;
#endif
                default:
                        return EAFNOSUPPORT;
                }

                /* check sa_family looks sane for the cmd */
                switch (cmd) {
                case SIOCSIFPHYADDR:
                        if (src->sa_family == AF_INET)
                                break;
                        return EAFNOSUPPORT;
#ifdef INET6
                case SIOCSIFPHYADDR_IN6:
                        if (src->sa_family == AF_INET6)
                                break;
                        return EAFNOSUPPORT;
#endif /* INET6 */
                case SIOCSLIFPHYADDR:
                        /* checks done in the above */
                        break;
                }

                error = gif_set_tunnel(&sc->gif_if, src, dst);
                break;

#ifdef SIOCDIFPHYADDR
        case SIOCDIFPHYADDR:
                gif_delete_tunnel(&sc->gif_if);
                break;
#endif

        case SIOCGIFPSRCADDR:
#ifdef INET6
        case SIOCGIFPSRCADDR_IN6:
#endif /* INET6 */
                if (sc->gif_psrc == NULL) {
                        error = EADDRNOTAVAIL;
                        goto bad;
                }
                src = sc->gif_psrc;
                switch (cmd) {
#ifdef INET
                case SIOCGIFPSRCADDR:
                        dst = &ifr->ifr_addr;
                        size = sizeof(ifr->ifr_addr);
                        break;
#endif /* INET */
#ifdef INET6
                case SIOCGIFPSRCADDR_IN6:
                        dst = (struct sockaddr *)
                                &(((struct in6_ifreq *)data)->ifr_addr);
                        size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
                        break;
#endif /* INET6 */
                default:
                        error = EADDRNOTAVAIL;
                        goto bad;
                }
                if (src->sa_len > size)
                        return EINVAL;
                bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
                break;

        case SIOCGIFPDSTADDR:
#ifdef INET6
        case SIOCGIFPDSTADDR_IN6:
#endif /* INET6 */
                if (sc->gif_pdst == NULL) {
                        error = EADDRNOTAVAIL;
                        goto bad;
                }
                src = sc->gif_pdst;
                switch (cmd) {
#ifdef INET
                case SIOCGIFPDSTADDR:
                        dst = &ifr->ifr_addr;
                        size = sizeof(ifr->ifr_addr);
                        break;
#endif /* INET */
#ifdef INET6
                case SIOCGIFPDSTADDR_IN6:
                        dst = (struct sockaddr *)
                                &(((struct in6_ifreq *)data)->ifr_addr);
                        size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
                        break;
#endif /* INET6 */
                default:
                        error = EADDRNOTAVAIL;
                        goto bad;
                }
                if (src->sa_len > size)
                        return EINVAL;
                bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
                break;

        case SIOCGLIFPHYADDR:
                if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
                        error = EADDRNOTAVAIL;
                        goto bad;
                }

                /* copy src */
                src = sc->gif_psrc;
                dst = (struct sockaddr *)
                        &(((struct if_laddrreq *)data)->addr);
                size = sizeof(((struct if_laddrreq *)data)->addr);
                if (src->sa_len > size)
                        return EINVAL;
                bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);

                /* copy dst */
                src = sc->gif_pdst;
                dst = (struct sockaddr *)
                        &(((struct if_laddrreq *)data)->dstaddr);
                size = sizeof(((struct if_laddrreq *)data)->dstaddr);
                if (src->sa_len > size)
                        return EINVAL;
                bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
                break;

        case SIOCSIFFLAGS:
                /* if_ioctl() takes care of it */
                break;

        default:
                error = EINVAL;
                break;
        }
 bad:
        return error;
}

int
gif_set_tunnel(struct ifnet *ifp, struct sockaddr *src, struct sockaddr *dst)
{
        struct gif_softc *sc = (struct gif_softc *)ifp;
        struct gif_softc *sc2;
        struct sockaddr *osrc, *odst, *sa;
        int error = 0;

        crit_enter();

        LIST_FOREACH(sc2, &gif_softc_list, gif_list) {
                if (sc2 == sc)
                        continue;
                if (!sc2->gif_pdst || !sc2->gif_psrc)
                        continue;
                if (sc2->gif_pdst->sa_family != dst->sa_family ||
                    sc2->gif_pdst->sa_len != dst->sa_len ||
                    sc2->gif_psrc->sa_family != src->sa_family ||
                    sc2->gif_psrc->sa_len != src->sa_len)
                        continue;

                /*
                 * Disallow parallel tunnels unless instructed
                 * otherwise.
                 */
                if (!parallel_tunnels &&
                    bcmp(sc2->gif_pdst, dst, dst->sa_len) == 0 &&
                    bcmp(sc2->gif_psrc, src, src->sa_len) == 0) {
                        error = EADDRNOTAVAIL;
                        goto bad;
                }

                /* XXX both end must be valid? (I mean, not 0.0.0.0) */
        }

        /* XXX we can detach from both, but be polite just in case */
        if (sc->gif_psrc) {
                switch (sc->gif_psrc->sa_family) {
#ifdef INET
                case AF_INET:
                        in_gif_detach(sc);
                        break;
#endif
#ifdef INET6
                case AF_INET6:
                        in6_gif_detach(sc);
                        break;
#endif
                }
                gif_clear_cache(sc);
        }

        osrc = sc->gif_psrc;
        sa = (struct sockaddr *)kmalloc(src->sa_len, M_IFADDR, M_WAITOK);
        bcopy((caddr_t)src, (caddr_t)sa, src->sa_len);
        sc->gif_psrc = sa;

        odst = sc->gif_pdst;
        sa = (struct sockaddr *)kmalloc(dst->sa_len, M_IFADDR, M_WAITOK);
        bcopy((caddr_t)dst, (caddr_t)sa, dst->sa_len);
        sc->gif_pdst = sa;

        switch (sc->gif_psrc->sa_family) {
#ifdef INET
        case AF_INET:
                error = in_gif_attach(sc);
                break;
#endif
#ifdef INET6
        case AF_INET6:
                error = in6_gif_attach(sc);
                break;
#endif
        }
        if (error) {
                /* rollback */
                kfree((caddr_t)sc->gif_psrc, M_IFADDR);
                kfree((caddr_t)sc->gif_pdst, M_IFADDR);
                sc->gif_psrc = osrc;
                sc->gif_pdst = odst;
                goto bad;
        }

        if (osrc)
                kfree((caddr_t)osrc, M_IFADDR);
        if (odst)
                kfree((caddr_t)odst, M_IFADDR);

        if (sc->gif_psrc && sc->gif_pdst)
                ifp->if_flags |= IFF_RUNNING;
        else
                ifp->if_flags &= ~IFF_RUNNING;
        crit_exit();

        return 0;

 bad:
        if (sc->gif_psrc && sc->gif_pdst)
                ifp->if_flags |= IFF_RUNNING;
        else
                ifp->if_flags &= ~IFF_RUNNING;
        crit_exit();

        return error;
}

void
gif_delete_tunnel(struct ifnet *ifp)
{
        struct gif_softc *sc = (struct gif_softc *)ifp;

        crit_enter();

        if (sc->gif_psrc) {
                kfree((caddr_t)sc->gif_psrc, M_IFADDR);
                sc->gif_psrc = NULL;
        }
        if (sc->gif_pdst) {
                kfree((caddr_t)sc->gif_pdst, M_IFADDR);
                sc->gif_pdst = NULL;
        }
        /* it is safe to detach from both */
#ifdef INET
        in_gif_detach(sc);
#endif
#ifdef INET6
        in6_gif_detach(sc);
#endif
        gif_clear_cache(sc);

        if (sc->gif_psrc && sc->gif_pdst)
                ifp->if_flags |= IFF_RUNNING;
        else
                ifp->if_flags &= ~IFF_RUNNING;
        crit_exit();
}