/*      $NetBSD: if_gif.c,v 1.159 2024/09/15 09:46:45 skrll Exp $       */
/*      $KAME: if_gif.c,v 1.76 2001/08/20 02:01:02 kjc 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.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: if_gif.c,v 1.159 2024/09/15 09:46:45 skrll Exp $");

#ifdef _KERNEL_OPT
#include "opt_inet.h"
#include "opt_net_mpsafe.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/atomic.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/socketvar.h>
#include <sys/syslog.h>
#include <sys/proc.h>
#include <sys/cpu.h>
#include <sys/intr.h>
#include <sys/kmem.h>
#include <sys/sysctl.h>
#include <sys/xcall.h>
#include <sys/device.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/pserialize.h>
#include <sys/psref.h>

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

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

#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>
#endif /* INET6 */

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

#include "ioconf.h"

#ifdef NET_MPSAFE
#define GIF_MPSAFE      1
#endif

/*
 * gif global variable definitions
 */
static struct {
        LIST_HEAD(gif_sclist, gif_softc) list;
        kmutex_t lock;
} gif_softcs __cacheline_aligned;

struct psref_class *gv_psref_class __read_mostly;

static pktq_rps_hash_func_t gif_pktq_rps_hash_p;

static int      gifattach0(struct gif_softc *);
static int      gif_output(struct ifnet *, struct mbuf *,
                           const struct sockaddr *, const struct rtentry *);
static void     gif_start(struct ifnet *);
static int      gif_transmit(struct ifnet *, struct mbuf *);
static int      gif_transmit_direct(struct gif_variant *, struct mbuf *);
static int      gif_ioctl(struct ifnet *, u_long, void *);
static int      gif_set_tunnel(struct ifnet *, struct sockaddr *,
                               struct sockaddr *);
static void     gif_delete_tunnel(struct ifnet *);

static int      gif_clone_create(struct if_clone *, int);
static int      gif_clone_destroy(struct ifnet *);
static int      gif_check_nesting(struct ifnet *, struct mbuf *);

static int      gif_encap_attach(struct gif_variant *);
static int      gif_encap_detach(struct gif_variant *);

static void     gif_update_variant(struct gif_softc *, struct gif_variant *);

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

#ifndef MAX_GIF_NEST
/*
 * This macro controls the 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;

static struct sysctllog *gif_sysctl;

#ifdef INET6
static int
sysctl_gif_pmtu_global(SYSCTLFN_ARGS)
{
        int error, pmtu;
        struct sysctlnode node = *rnode;

        pmtu = ip6_gif_pmtu;
        node.sysctl_data = &pmtu;
        error = sysctl_lookup(SYSCTLFN_CALL(&node));
        if (error || newp == NULL)
                return error;

        switch (pmtu) {
        case GIF_PMTU_MINMTU:
        case GIF_PMTU_OUTERMTU:
                ip6_gif_pmtu = pmtu;
                break;
        default:
                return EINVAL;
        }

        return 0;
}

static int
sysctl_gif_pmtu_perif(SYSCTLFN_ARGS)
{
        int error, pmtu;
        struct sysctlnode node = *rnode;
        struct gif_softc *sc = (struct gif_softc *)node.sysctl_data;

        pmtu = sc->gif_pmtu;
        node.sysctl_data = &pmtu;
        error = sysctl_lookup(SYSCTLFN_CALL(&node));
        if (error || newp == NULL)
                return error;

        switch (pmtu) {
        case GIF_PMTU_SYSDEFAULT:
        case GIF_PMTU_MINMTU:
        case GIF_PMTU_OUTERMTU:
                sc->gif_pmtu = pmtu;
                break;
        default:
                return EINVAL;
        }

        return 0;
}
#endif

static void
gif_sysctl_setup(void)
{
        const struct sysctlnode *node = NULL;

        gif_sysctl = NULL;

#ifdef INET
        /*
         * Previously create "net.inet.ip" entry to avoid sysctl_createv error.
         */
        sysctl_createv(NULL, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "inet",
                       SYSCTL_DESCR("PF_INET related settings"),
                       NULL, 0, NULL, 0,
                       CTL_NET, PF_INET, CTL_EOL);
        sysctl_createv(NULL, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "ip",
                       SYSCTL_DESCR("IPv4 related settings"),
                       NULL, 0, NULL, 0,
                       CTL_NET, PF_INET, IPPROTO_IP, CTL_EOL);

        sysctl_createv(&gif_sysctl, 0, NULL, NULL,
                       CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
                       CTLTYPE_INT, "gifttl",
                       SYSCTL_DESCR("Default TTL for a gif tunnel datagram"),
                       NULL, 0, &ip_gif_ttl, 0,
                       CTL_NET, PF_INET, IPPROTO_IP,
                       IPCTL_GIF_TTL, CTL_EOL);
#endif
#ifdef INET6
        /*
         * Previously create "net.inet6.ip6" entry to avoid sysctl_createv error.
         */
        sysctl_createv(NULL, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "inet6",
                       SYSCTL_DESCR("PF_INET6 related settings"),
                       NULL, 0, NULL, 0,
                       CTL_NET, PF_INET6, CTL_EOL);
        sysctl_createv(NULL, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "ip6",
                       SYSCTL_DESCR("IPv6 related settings"),
                       NULL, 0, NULL, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6, CTL_EOL);

        sysctl_createv(&gif_sysctl, 0, NULL, NULL,
                       CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
                       CTLTYPE_INT, "gifhlim",
                       SYSCTL_DESCR("Default hop limit for a gif tunnel datagram"),
                       NULL, 0, &ip6_gif_hlim, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_GIF_HLIM, CTL_EOL);

        sysctl_createv(&gif_sysctl, 0, NULL, NULL,
                       CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
                       CTLTYPE_INT, "gifpmtu",
                       SYSCTL_DESCR("Default Path MTU setting for gif tunnels"),
                       sysctl_gif_pmtu_global, 0, NULL, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_GIF_PMTU, CTL_EOL);
#endif

        sysctl_createv(&gif_sysctl, 0, NULL, &node,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "gif",
                       SYSCTL_DESCR("gif global control"),
                       NULL, 0, NULL, 0,
                       CTL_NET, CTL_CREATE, CTL_EOL);

        sysctl_createv(&gif_sysctl, 0, &node, NULL,
                       CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
                       CTLTYPE_STRING, "rps_hash",
                       SYSCTL_DESCR("Interface rps hash function control"),
                       sysctl_pktq_rps_hash_handler, 0, (void *)&gif_pktq_rps_hash_p,
                       PKTQ_RPS_HASH_NAME_LEN,
                       CTL_CREATE, CTL_EOL);
}

static void
gif_perif_sysctl_setup(struct sysctllog **clog, struct gif_softc *sc)
{
#ifdef INET6
        const struct sysctlnode *cnode, *rnode;
        struct ifnet *ifp = &sc->gif_if;
        const char *ifname = ifp->if_xname;
        int rv;

        /*
         * Already created in sysctl_sndq_setup().
         */
        sysctl_createv(clog, 0, NULL, &rnode,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "interfaces",
                       SYSCTL_DESCR("Per-interface controls"),
                       NULL, 0, NULL, 0,
                       CTL_NET, CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, &rnode, &rnode,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, ifname,
                       SYSCTL_DESCR("Interface controls"),
                       NULL, 0, NULL, 0,
                       CTL_CREATE, CTL_EOL);

        rv = sysctl_createv(clog, 0, &rnode, &cnode,
                            CTLFLAG_PERMANENT,
                            CTLTYPE_INT, "pmtu",
                            SYSCTL_DESCR("Path MTU setting for this gif tunnel"),
                            sysctl_gif_pmtu_perif, 0, (void *)sc, 0,
                            CTL_CREATE, CTL_EOL);
        if (rv != 0)
                log(LOG_WARNING, "%s: could not attach sysctl node pmtu\n", ifname);

        sc->gif_pmtu = GIF_PMTU_SYSDEFAULT;
#endif
}

/* ARGSUSED */
void
gifattach(int count)
{
        /*
         * Nothing to do here, initialization is handled by the
         * module initialization code in gifinit() below).
         */
}

static void
gifinit(void)
{

        mutex_init(&gif_softcs.lock, MUTEX_DEFAULT, IPL_NONE);
        LIST_INIT(&gif_softcs.list);
        if_clone_attach(&gif_cloner);

        gv_psref_class = psref_class_create("gifvar", IPL_SOFTNET);

        gif_pktq_rps_hash_p = pktq_rps_hash_default;
        gif_sysctl_setup();
}

static int
gifdetach(void)
{

        mutex_enter(&gif_softcs.lock);
        if (!LIST_EMPTY(&gif_softcs.list)) {
                mutex_exit(&gif_softcs.lock);
                return EBUSY;
        }

        psref_class_destroy(gv_psref_class);

        if_clone_detach(&gif_cloner);
        sysctl_teardown(&gif_sysctl);
        mutex_exit(&gif_softcs.lock);
        mutex_destroy(&gif_softcs.lock);
        return 0;
}

static int
gif_clone_create(struct if_clone *ifc, int unit)
{
        struct gif_softc *sc;
        struct gif_variant *var;
        struct ifnet *ifp;
        int rv;

        sc = kmem_zalloc(sizeof(struct gif_softc), KM_SLEEP);

        if_initname(&sc->gif_if, ifc->ifc_name, unit);

        rv = gifattach0(sc);
        if (rv != 0) {
                kmem_free(sc, sizeof(struct gif_softc));
                return rv;
        }

        ifp = &sc->gif_if;
        gif_perif_sysctl_setup(&ifp->if_sysctl_log, sc);

        var = kmem_zalloc(sizeof(*var), KM_SLEEP);
        var->gv_softc = sc;
        psref_target_init(&var->gv_psref, gv_psref_class);

        sc->gif_var = var;
        mutex_init(&sc->gif_lock, MUTEX_DEFAULT, IPL_NONE);
        sc->gif_psz = pserialize_create();

        sc->gif_ro_percpu = if_tunnel_alloc_ro_percpu();
        mutex_enter(&gif_softcs.lock);
        LIST_INSERT_HEAD(&gif_softcs.list, sc, gif_list);
        mutex_exit(&gif_softcs.lock);
        return 0;
}

static int
gifattach0(struct gif_softc *sc)
{

        sc->gif_if.if_addrlen = 0;
        sc->gif_if.if_mtu    = GIF_MTU;
        sc->gif_if.if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
#ifdef GIF_MPSAFE
        sc->gif_if.if_extflags  |= IFEF_MPSAFE;
#endif
        sc->gif_if.if_ioctl  = gif_ioctl;
        sc->gif_if.if_output = gif_output;
        sc->gif_if.if_start = gif_start;
        sc->gif_if.if_transmit = gif_transmit;
        sc->gif_if.if_type   = IFT_GIF;
        sc->gif_if.if_dlt    = DLT_NULL;
        sc->gif_if.if_softc  = sc;
        IFQ_SET_READY(&sc->gif_if.if_snd);
        if_initialize(&sc->gif_if);

        sc->gif_if.if_link_state = LINK_STATE_DOWN;
        if_alloc_sadl(&sc->gif_if);
        bpf_attach(&sc->gif_if, DLT_NULL, sizeof(u_int));
        if_register(&sc->gif_if);
        return 0;
}

static int
gif_clone_destroy(struct ifnet *ifp)
{
        struct gif_softc *sc = (void *) ifp;
        struct gif_variant *var;

        LIST_REMOVE(sc, gif_list);

        gif_delete_tunnel(&sc->gif_if);
        bpf_detach(ifp);
        if_detach(ifp);

        if_tunnel_free_ro_percpu(sc->gif_ro_percpu);

        pserialize_destroy(sc->gif_psz);
        mutex_destroy(&sc->gif_lock);

        var = sc->gif_var;
        kmem_free(var, sizeof(*var));
        kmem_free(sc, sizeof(struct gif_softc));

        return 0;
}

#ifdef GIF_ENCAPCHECK
int
gif_encapcheck(struct mbuf *m, int off, int proto, void *arg)
{
        struct ip ip;
        struct gif_softc *sc;
        struct gif_variant *var;
        struct psref psref;
        int ret = 0;

        sc = arg;
        if (sc == NULL)
                return 0;

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

        var = gif_getref_variant(sc, &psref);
        /* no physical address */
        if (var->gv_psrc == NULL || var->gv_pdst == NULL)
                goto out;

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

        /* Bail on short packets */
        KASSERT(m->m_flags & M_PKTHDR);
        if (m->m_pkthdr.len < sizeof(ip))
                goto  out;

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

        switch (ip.ip_v) {
#ifdef INET
        case 4:
                if (var->gv_psrc->sa_family != AF_INET ||
                    var->gv_pdst->sa_family != AF_INET)
                        goto out;
                ret = gif_encapcheck4(m, off, proto, var);
                break;
#endif
#ifdef INET6
        case 6:
                if (m->m_pkthdr.len < sizeof(struct ip6_hdr))
                        goto out;
                if (var->gv_psrc->sa_family != AF_INET6 ||
                    var->gv_pdst->sa_family != AF_INET6)
                        goto out;
                ret = gif_encapcheck6(m, off, proto, var);
                break;
#endif
        default:
                goto out;
        }

out:
        gif_putref_variant(var, &psref);
        return ret;
}
#endif

/*
 * gif may cause infinite recursion calls when misconfigured.
 * We'll prevent this by introducing upper limit.
 */
static int
gif_check_nesting(struct ifnet *ifp, struct mbuf *m)
{

        return if_tunnel_check_nesting(ifp, m, max_gif_nesting);
}

static int
gif_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
    const struct rtentry *rt)
{
        struct gif_softc *sc = ifp->if_softc;
        struct gif_variant *var = NULL;
        struct psref psref;
        int error = 0;

        IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family);

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

        if ((ifp->if_flags & IFF_UP) == 0) {
                m_freem(m);
                error = ENETDOWN;
                goto end;
        }

        var = gif_getref_variant(sc, &psref);
        if (var->gv_psrc == NULL || var->gv_pdst == NULL) {
                m_freem(m);
                error = ENETDOWN;
                goto end;
        }
        /* XXX should we check if our outer source is legal? */

        m->m_flags &= ~(M_BCAST | M_MCAST);

        /* use DLT_NULL encapsulation here to pass inner af type */
        M_PREPEND(m, sizeof(int), M_DONTWAIT);
        if (!m) {
                error = ENOBUFS;
                goto end;
        }
        *mtod(m, int *) = dst->sa_family;

        /* Clear checksum-offload flags. */
        m->m_pkthdr.csum_flags = 0;
        m->m_pkthdr.csum_data = 0;

        error = if_transmit_lock(ifp, m);

end:
        if (var != NULL)
                gif_putref_variant(var, &psref);
        if (error)
                if_statinc(ifp, if_oerrors);
        return error;
}

static void
gif_start(struct ifnet *ifp)
{
        struct gif_softc *sc;
        struct gif_variant *var;
        struct mbuf *m;
        struct psref psref;
        int family;
        int len;
        int error;

        sc = ifp->if_softc;
        var = gif_getref_variant(sc, &psref);

        KASSERT(var->gv_output != NULL);

        /* output processing */
        while (1) {
                IFQ_DEQUEUE(&sc->gif_if.if_snd, m);
                if (m == NULL)
                        break;

                /* grab and chop off inner af type */
                if (sizeof(int) > m->m_len) {
                        m = m_pullup(m, sizeof(int));
                        if (!m) {
                                if_statinc(ifp, if_oerrors);
                                continue;
                        }
                }
                family = *mtod(m, int *);
                bpf_mtap(ifp, m, BPF_D_OUT);
                m_adj(m, sizeof(int));

                len = m->m_pkthdr.len;

                error = var->gv_output(var, family, m);
                if (error)
                        if_statinc(ifp, if_oerrors);
                else
                        if_statadd2(ifp, if_opackets, 1, if_obytes, len);
        }

        gif_putref_variant(var, &psref);
}

static int
gif_transmit(struct ifnet *ifp, struct mbuf *m)
{
        struct gif_softc *sc;
        struct gif_variant *var;
        struct psref psref;
        int error;

        sc = ifp->if_softc;

        /* output processing */
        if (m == NULL)
                return EINVAL;

        var = gif_getref_variant(sc, &psref);
        error = gif_transmit_direct(var, m);
        gif_putref_variant(var, &psref);

        return error;
}

static int
gif_transmit_direct(struct gif_variant *var, struct mbuf *m)
{
        struct ifnet *ifp = &var->gv_softc->gif_if;
        int error;
        int family;
        int len;

        KASSERT(gif_heldref_variant(var));
        KASSERT(var->gv_output != NULL);

        /* grab and chop off inner af type */
        if (sizeof(int) > m->m_len) {
                m = m_pullup(m, sizeof(int));
                if (!m) {
                        if_statinc(ifp, if_oerrors);
                        return ENOBUFS;
                }
        }
        family = *mtod(m, int *);
        bpf_mtap(ifp, m, BPF_D_OUT);
        m_adj(m, sizeof(int));

        len = m->m_pkthdr.len;

        error = var->gv_output(var, family, m);
        if (error)
                if_statinc(ifp, if_oerrors);
        else
                if_statadd2(ifp, if_opackets, 1, if_obytes, len);

        return error;
}

void
gif_input(struct mbuf *m, int af, struct ifnet *ifp)
{
        pktqueue_t *pktq;
        size_t pktlen;

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

        m_set_rcvif(m, ifp);
        pktlen = m->m_pkthdr.len;

        bpf_mtap_af(ifp, af, m, BPF_D_IN);

        /*
         * Put the packet to the network layer input queue according to the
         * specified address family.  Note: we avoid direct call to the
         * input function of the network layer in order to avoid recursion.
         * This may be revisited in the future.
         */
        switch (af) {
#ifdef INET
        case AF_INET:
                pktq = ip_pktq;
                break;
#endif
#ifdef INET6
        case AF_INET6:
                pktq = ip6_pktq;
                break;
#endif
        default:
                m_freem(m);
                return;
        }

        const uint32_t h = pktq_rps_hash(&gif_pktq_rps_hash_p, m);
        if (__predict_true(pktq_enqueue(pktq, m, h))) {
                if_statadd2(ifp, if_ibytes, pktlen, if_ipackets, 1);
        } else {
                m_freem(m);
        }
}

/* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
static int
gif_ioctl(struct ifnet *ifp, u_long cmd, void *data)
{
        struct gif_softc *sc  = ifp->if_softc;
        struct ifreq     *ifr = (struct ifreq*)data;
        struct ifaddr    *ifa = (struct ifaddr*)data;
        int error = 0, size, bound;
        struct sockaddr *dst, *src;
        struct gif_variant *var;
        struct psref psref;

        switch (cmd) {
        case SIOCINITIFADDR:
                ifp->if_flags |= IFF_UP;
                ifa->ifa_rtrequest = p2p_rtrequest;
                break;

        case SIOCADDMULTI:
        case SIOCDELMULTI:
                switch (ifr->ifr_addr.sa_family) {
#ifdef INET
                case AF_INET:   /* IP supports Multicast */
                        break;
#endif /* INET */
#ifdef INET6
                case AF_INET6:  /* IP6 supports Multicast */
                        break;
#endif /* INET6 */
                default:  /* Other protocols doesn't support Multicast */
                        error = EAFNOSUPPORT;
                        break;
                }
                break;

        case SIOCSIFMTU:
                if (ifr->ifr_mtu < GIF_MTU_MIN || ifr->ifr_mtu > GIF_MTU_MAX)
                        return EINVAL;
                else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
                        error = 0;
                break;

#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;
                }

                /*
                 * calls gif_getref_variant() for other softcs to check
                 * address pair duplication
                 */
                bound = curlwp_bind();
                error = gif_set_tunnel(&sc->gif_if, src, dst);
                if (error == 0)
                        if_link_state_change(&sc->gif_if, LINK_STATE_UP);
                curlwp_bindx(bound);

                break;

#ifdef SIOCDIFPHYADDR
        case SIOCDIFPHYADDR:
                bound = curlwp_bind();
                gif_delete_tunnel(&sc->gif_if);
                if_link_state_change(&sc->gif_if, LINK_STATE_DOWN);
                curlwp_bindx(bound);
                break;
#endif

        case SIOCGIFPSRCADDR:
#ifdef INET6
        case SIOCGIFPSRCADDR_IN6:
#endif /* INET6 */
                bound = curlwp_bind();
                var = gif_getref_variant(sc, &psref);
                if (var->gv_psrc == NULL) {
                        gif_putref_variant(var, &psref);
                        curlwp_bindx(bound);
                        error = EADDRNOTAVAIL;
                        goto bad;
                }
                src = var->gv_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:
                        gif_putref_variant(var, &psref);
                        curlwp_bindx(bound);
                        error = EADDRNOTAVAIL;
                        goto bad;
                }
                if (src->sa_len > size) {
                        gif_putref_variant(var, &psref);
                        curlwp_bindx(bound);
                        return EINVAL;
                }
                memcpy(dst, src, src->sa_len);
                gif_putref_variant(var, &psref);
                curlwp_bindx(bound);
                break;

        case SIOCGIFPDSTADDR:
#ifdef INET6
        case SIOCGIFPDSTADDR_IN6:
#endif /* INET6 */
                bound = curlwp_bind();
                var = gif_getref_variant(sc, &psref);
                if (var->gv_pdst == NULL) {
                        gif_putref_variant(var, &psref);
                        curlwp_bindx(bound);
                        error = EADDRNOTAVAIL;
                        goto bad;
                }
                src = var->gv_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:
                        gif_putref_variant(var, &psref);
                        curlwp_bindx(bound);
                        error = EADDRNOTAVAIL;
                        goto bad;
                }
                if (src->sa_len > size) {
                        gif_putref_variant(var, &psref);
                        curlwp_bindx(bound);
                        return EINVAL;
                }
                memcpy(dst, src, src->sa_len);
                gif_putref_variant(var, &psref);
                curlwp_bindx(bound);
                break;

        case SIOCGLIFPHYADDR:
                bound = curlwp_bind();
                var = gif_getref_variant(sc, &psref);
                if (var->gv_psrc == NULL || var->gv_pdst == NULL) {
                        gif_putref_variant(var, &psref);
                        curlwp_bindx(bound);
                        error = EADDRNOTAVAIL;
                        goto bad;
                }

                /* copy src */
                src = var->gv_psrc;
                dst = (struct sockaddr *)
                        &(((struct if_laddrreq *)data)->addr);
                size = sizeof(((struct if_laddrreq *)data)->addr);
                if (src->sa_len > size) {
                        gif_putref_variant(var, &psref);
                        curlwp_bindx(bound);
                        return EINVAL;
                }
                memcpy(dst, src, src->sa_len);

                /* copy dst */
                src = var->gv_pdst;
                dst = (struct sockaddr *)
                        &(((struct if_laddrreq *)data)->dstaddr);
                size = sizeof(((struct if_laddrreq *)data)->dstaddr);
                if (src->sa_len > size) {
                        gif_putref_variant(var, &psref);
                        curlwp_bindx(bound);
                        return EINVAL;
                }
                memcpy(dst, src, src->sa_len);
                gif_putref_variant(var, &psref);
                curlwp_bindx(bound);
                break;

        default:
                return ifioctl_common(ifp, cmd, data);
        }
 bad:
        return error;
}

static int
gif_encap_attach(struct gif_variant *var)
{
        int error;

        if (var == NULL || var->gv_psrc == NULL)
                return EINVAL;

        switch (var->gv_psrc->sa_family) {
#ifdef INET
        case AF_INET:
                error = in_gif_attach(var);
                break;
#endif
#ifdef INET6
        case AF_INET6:
                error = in6_gif_attach(var);
                break;
#endif
        default:
                error = EINVAL;
                break;
        }

        return error;
}

static int
gif_encap_detach(struct gif_variant *var)
{
        int error;

        if (var == NULL || var->gv_psrc == NULL)
                return EINVAL;

        switch (var->gv_psrc->sa_family) {
#ifdef INET
        case AF_INET:
                error = in_gif_detach(var);
                break;
#endif
#ifdef INET6
        case AF_INET6:
                error = in6_gif_detach(var);
                break;
#endif
        default:
                error = EINVAL;
                break;
        }

        return error;
}

static int
gif_set_tunnel(struct ifnet *ifp, struct sockaddr *src, struct sockaddr *dst)
{
        struct gif_softc *sc = ifp->if_softc;
        struct gif_softc *sc2;
        struct gif_variant *ovar, *nvar;
        struct sockaddr *osrc, *odst;
        struct sockaddr *nsrc, *ndst;
        int error;
#ifndef GIF_MPSAFE
        int s;

        s = splsoftnet();
#endif
        error = encap_lock_enter();
        if (error) {
#ifndef GIF_MPSAFE
                splx(s);
#endif
                return error;
        }

        nsrc = sockaddr_dup(src, M_WAITOK);
        ndst = sockaddr_dup(dst, M_WAITOK);
        nvar = kmem_alloc(sizeof(*nvar), KM_SLEEP);

        mutex_enter(&sc->gif_lock);

        ovar = sc->gif_var;

        if ((ovar->gv_pdst && sockaddr_cmp(ovar->gv_pdst, dst) == 0) &&
            (ovar->gv_psrc && sockaddr_cmp(ovar->gv_psrc, src) == 0)) {
                /* address and port pair not changed. */
                error = 0;
                goto out;
        }

        mutex_enter(&gif_softcs.lock);
        LIST_FOREACH(sc2, &gif_softcs.list, gif_list) {
                struct gif_variant *var2;
                struct psref psref;

                if (sc2 == sc)
                        continue;
                var2 = gif_getref_variant(sc2, &psref);
                if (!var2->gv_pdst || !var2->gv_psrc) {
                        gif_putref_variant(var2, &psref);
                        continue;
                }
                /* can't configure same pair of address onto two gifs */
                if (sockaddr_cmp(var2->gv_pdst, dst) == 0 &&
                    sockaddr_cmp(var2->gv_psrc, src) == 0) {
                        /* continue to use the old configuration. */
                        gif_putref_variant(var2, &psref);
                        mutex_exit(&gif_softcs.lock);
                        error =  EADDRNOTAVAIL;
                        goto out;
                }
                gif_putref_variant(var2, &psref);
                /* XXX both end must be valid? (I mean, not 0.0.0.0) */
        }
        mutex_exit(&gif_softcs.lock);

        osrc = ovar->gv_psrc;
        odst = ovar->gv_pdst;

        *nvar = *ovar;
        nvar->gv_psrc = nsrc;
        nvar->gv_pdst = ndst;
        nvar->gv_encap_cookie4 = NULL;
        nvar->gv_encap_cookie6 = NULL;
        error = gif_encap_attach(nvar);
        if (error)
                goto out;
        psref_target_init(&nvar->gv_psref, gv_psref_class);
        gif_update_variant(sc, nvar);

        mutex_exit(&sc->gif_lock);

        (void)gif_encap_detach(ovar);
        encap_lock_exit();

        if (osrc)
                sockaddr_free(osrc);
        if (odst)
                sockaddr_free(odst);
        kmem_free(ovar, sizeof(*ovar));

#ifndef GIF_MPSAFE
        splx(s);
#endif
        return 0;

 out:
        mutex_exit(&sc->gif_lock);
        encap_lock_exit();

        sockaddr_free(nsrc);
        sockaddr_free(ndst);
        kmem_free(nvar, sizeof(*nvar));

#ifndef GIF_MPSAFE
        splx(s);
#endif
        return error;
}

static void
gif_delete_tunnel(struct ifnet *ifp)
{
        struct gif_softc *sc = ifp->if_softc;
        struct gif_variant *ovar, *nvar;
        struct sockaddr *osrc, *odst;
        int error;
#ifndef GIF_MPSAFE
        int s;

        s = splsoftnet();
#endif
        error = encap_lock_enter();
        if (error) {
#ifndef GIF_MPSAFE
                splx(s);
#endif
                return;
        }

        nvar = kmem_alloc(sizeof(*nvar), KM_SLEEP);

        mutex_enter(&sc->gif_lock);

        ovar = sc->gif_var;
        osrc = ovar->gv_psrc;
        odst = ovar->gv_pdst;
        if (osrc == NULL || odst == NULL) {
                /* address pair not changed. */
                mutex_exit(&sc->gif_lock);
                encap_lock_exit();
                kmem_free(nvar, sizeof(*nvar));
#ifndef GIF_MPSAFE
                splx(s);
#endif
                return;
        }

        *nvar = *ovar;
        nvar->gv_psrc = NULL;
        nvar->gv_pdst = NULL;
        nvar->gv_encap_cookie4 = NULL;
        nvar->gv_encap_cookie6 = NULL;
        nvar->gv_output = NULL;
        psref_target_init(&nvar->gv_psref, gv_psref_class);
        gif_update_variant(sc, nvar);

        mutex_exit(&sc->gif_lock);

        gif_encap_detach(ovar);
        encap_lock_exit();

        sockaddr_free(osrc);
        sockaddr_free(odst);
        kmem_free(ovar, sizeof(*ovar));

#ifndef GIF_MPSAFE
        splx(s);
#endif
}

/*
 * gif_variant update API.
 *
 * Assumption:
 * reader side dereferences sc->gif_var in reader critical section only,
 * that is, all of reader sides do not reader the sc->gif_var after
 * pserialize_perform().
 */
static void
gif_update_variant(struct gif_softc *sc, struct gif_variant *nvar)
{
        struct ifnet *ifp = &sc->gif_if;
        struct gif_variant *ovar = sc->gif_var;

        KASSERT(mutex_owned(&sc->gif_lock));

        atomic_store_release(&sc->gif_var, nvar);
        pserialize_perform(sc->gif_psz);
        psref_target_destroy(&ovar->gv_psref, gv_psref_class);

        if (nvar->gv_psrc != NULL && nvar->gv_pdst != NULL)
                ifp->if_flags |= IFF_RUNNING;
        else
                ifp->if_flags &= ~IFF_RUNNING;
}

/*
 * Module infrastructure
 */
#include "if_module.h"

IF_MODULE(MODULE_CLASS_DRIVER, gif, "ip_ecn")