1 /* $NetBSD: if_gre.c,v 1.42 2002/08/14 00:23:27 itojun Exp $ */
2 /* $FreeBSD: src/sys/net/if_gre.c,v 1.9.2.3 2003/01/23 21:06:44 sam Exp $ */
5 * Copyright (c) 1998 The NetBSD Foundation, Inc.
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Heiko W.Rupp <hwr@pilhuhn.de>
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the NetBSD
22 * Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 * contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
41 * Encapsulate L3 protocols into IP
42 * See RFC 1701 and 1702 for more details.
43 * If_gre is compatible with Cisco GRE tunnels, so you can
44 * have a NetBSD box as the other end of a tunnel interface of a Cisco
45 * router. See gre(4) for more details.
46 * Also supported: IP in IP encaps (proto 55) as of RFC 2004
51 #include <sys/param.h>
52 #include <sys/kernel.h>
54 #include <sys/malloc.h>
58 #include <sys/protosw.h>
59 #include <sys/socket.h>
60 #include <sys/sockio.h>
61 #include <sys/sysctl.h>
62 #include <sys/systm.h>
63 #include <sys/thread2.h>
65 #include <net/ethernet.h>
67 #include <net/if_types.h>
68 #include <net/ifq_var.h>
69 #include <net/route.h>
70 #include <net/if_clone.h>
71 #include <net/netmsg2.h>
72 #include <net/netisr2.h>
75 #include <netinet/in.h>
76 #include <netinet/in_systm.h>
77 #include <netinet/in_var.h>
78 #include <netinet/ip.h>
79 #include <netinet/ip_gre.h>
80 #include <netinet/ip_var.h>
81 #include <netinet/ip_encap.h>
83 #error "Huh? if_gre without inet?"
88 #include <net/net_osdep.h>
92 * It is not easy to calculate the right value for a GRE MTU.
93 * We leave this task to the admin and use the same default that
100 static MALLOC_DEFINE(M_GRE, GRENAME, "Generic Routing Encapsulation");
102 struct gre_softc_head gre_softc_list;
104 static int gre_clone_create(struct if_clone *, int, caddr_t);
105 static int gre_clone_destroy(struct ifnet *);
106 static int gre_ioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
107 static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *,
110 static struct if_clone gre_cloner = IF_CLONE_INITIALIZER("gre",
111 gre_clone_create, gre_clone_destroy, 0, IF_MAXUNIT);
113 static int gre_compute_route(struct gre_softc *sc, struct route *);
114 static int gre_check_route(struct gre_softc *sc);
116 static void greattach(void);
120 extern struct domain inetdomain;
122 static const struct protosw in_gre_protosw =
125 .pr_domain = &inetdomain,
126 .pr_protocol = IPPROTO_GRE,
127 .pr_flags = PR_ATOMIC|PR_ADDR,
129 .pr_input = gre_input,
130 .pr_output = rip_output,
132 .pr_ctloutput = rip_ctloutput,
135 .pr_usrreqs = &rip_usrreqs
138 static const struct protosw in_mobile_protosw =
141 .pr_domain = &inetdomain,
142 .pr_protocol = IPPROTO_MOBILE,
143 .pr_flags = PR_ATOMIC|PR_ADDR,
145 .pr_input = gre_mobile_input,
146 .pr_output = rip_output,
148 .pr_ctloutput = rip_ctloutput,
151 .pr_usrreqs = &rip_usrreqs
156 SYSCTL_DECL(_net_link);
157 SYSCTL_NODE(_net_link, IFT_OTHER, gre, CTLFLAG_RW, 0,
158 "Generic Routing Encapsulation");
161 * This macro controls the default upper limitation on nesting of gre tunnels.
162 * Since, setting a large value to this macro with a careless configuration
163 * may introduce system crash, we don't allow any nestings by default.
164 * If you need to configure nested gre tunnels, you can define this macro
165 * in your kernel configuration file. However, if you do so, please be
166 * careful to configure the tunnels so that it won't make a loop.
168 #define MAX_GRE_NEST 1
170 static int max_gre_nesting = MAX_GRE_NEST;
171 SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW,
172 &max_gre_nesting, 0, "Max nested tunnels");
179 LIST_INIT(&gre_softc_list);
180 if_clone_attach(&gre_cloner);
184 gre_clone_create(struct if_clone *ifc, int unit, caddr_t param __unused)
186 struct gre_softc *sc;
188 sc = kmalloc(sizeof(struct gre_softc), M_GRE, M_WAITOK);
189 memset(sc, 0, sizeof(struct gre_softc));
191 sc->sc_if.if_softc = sc;
192 if_initname(&(sc->sc_if), GRENAME, unit);
193 ifq_set_maxlen(&sc->sc_if.if_snd, IFQ_MAXLEN);
194 sc->sc_if.if_type = IFT_OTHER;
195 sc->sc_if.if_addrlen = 0;
196 sc->sc_if.if_hdrlen = 24; /* IP + GRE */
197 sc->sc_if.if_mtu = GREMTU;
198 sc->sc_if.if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
199 sc->sc_if.if_output = gre_output;
200 sc->sc_if.if_ioctl = gre_ioctl;
201 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY;
202 sc->g_proto = IPPROTO_GRE;
203 sc->sc_if.if_flags |= IFF_LINK0;
206 sc->route_pcpu = kmalloc(netisr_ncpus * sizeof(struct route), M_GRE,
208 if_attach(&sc->sc_if, NULL);
209 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int32_t));
210 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list);
215 gre_clone_destroy(struct ifnet *ifp)
217 struct gre_softc *sc = ifp->if_softc;
221 if (sc->encap != NULL)
222 encap_detach(sc->encap);
224 LIST_REMOVE(sc, sc_list);
228 for (cpu = 0; cpu < netisr_ncpus; ++cpu) {
229 if (sc->route_pcpu[cpu].ro_rt != NULL) {
230 rtfree_async(sc->route_pcpu[cpu].ro_rt);
231 sc->route_pcpu[cpu].ro_rt = NULL;
234 kfree(sc->route_pcpu, M_GRE);
241 * The output routine. Takes a packet and encapsulates it in the protocol
242 * given by sc->g_proto. See also RFC 1701 and RFC 2004
245 gre_output_serialized(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
249 struct gre_softc *sc = ifp->if_softc;
253 struct mobile_h mob_h;
255 struct sockaddr_in *ro_dst;
257 ASSERT_NETISR_NCPUS(mycpuid);
260 * gre may cause infinite recursion calls when misconfigured.
261 * We'll prevent this by introducing upper limit.
263 if (++(sc->called) > max_gre_nesting) {
264 kprintf("%s: gre_output: recursively called too many "
265 "times(%d)\n", if_name(&sc->sc_if), sc->called);
267 error = EIO; /* is there better errno? */
271 if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) == 0 ||
272 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) {
278 ro = &sc->route_pcpu[mycpuid];
279 ro_dst = (struct sockaddr_in *)&ro->ro_dst;
280 if (ro->ro_rt != NULL &&
281 ((ro->ro_rt->rt_flags & RTF_UP) == 0 ||
282 ro_dst->sin_addr.s_addr != sc->g_dst.s_addr)) {
286 if (ro->ro_rt == NULL) {
287 error = gre_compute_route(sc, ro);
300 uint32_t af = dst->sa_family;
302 bpf_ptap(ifp->if_bpf, m, &af, sizeof(af));
307 m->m_flags &= ~(M_BCAST|M_MCAST);
309 if (sc->g_proto == IPPROTO_MOBILE) {
310 if (dst->sa_family == AF_INET) {
314 ip = mtod(m, struct ip *);
317 * RFC2004 specifies that fragmented datagrams shouldn't
320 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
322 error = EINVAL; /* is there better errno? */
325 memset(&mob_h, 0, MOB_H_SIZ_L);
326 mob_h.proto = (ip->ip_p) << 8;
327 mob_h.odst = ip->ip_dst.s_addr;
328 ip->ip_dst.s_addr = sc->g_dst.s_addr;
331 * If the packet comes from our host, we only change
332 * the destination address in the IP header.
333 * Else we also need to save and change the source
335 if (in_hosteq(ip->ip_src, sc->g_src)) {
338 mob_h.proto |= MOB_H_SBIT;
339 mob_h.osrc = ip->ip_src.s_addr;
340 ip->ip_src.s_addr = sc->g_src.s_addr;
343 mob_h.proto = htons(mob_h.proto);
344 mob_h.hcrc = gre_in_cksum((u_short *)&mob_h, msiz);
346 if ((m->m_data - msiz) < m->m_pktdat) {
348 MGETHDR(m0, M_NOWAIT, MT_HEADER);
355 m->m_data += sizeof(struct ip);
356 m->m_len -= sizeof(struct ip);
357 m0->m_pkthdr.len = m->m_pkthdr.len + msiz;
358 m0->m_len = msiz + sizeof(struct ip);
359 m0->m_data += max_linkhdr;
360 memcpy(mtod(m0, caddr_t), (caddr_t)ip,
363 } else { /* we have some space left in the old one */
366 m->m_pkthdr.len += msiz;
367 bcopy(ip, mtod(m, caddr_t),
370 ip = mtod(m, struct ip *);
371 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz);
372 ip->ip_len = ntohs(ip->ip_len) + msiz;
373 } else { /* AF_INET */
378 } else if (sc->g_proto == IPPROTO_GRE) {
379 switch (dst->sa_family) {
381 ip = mtod(m, struct ip *);
382 etype = ETHERTYPE_IP;
386 error = EAFNOSUPPORT;
389 M_PREPEND(m, sizeof(struct greip), M_NOWAIT);
396 if (m == NULL) { /* impossible */
401 gh = mtod(m, struct greip *);
402 if (sc->g_proto == IPPROTO_GRE) {
403 /* we don't have any GRE flags for now */
405 memset((void *)&gh->gi_g, 0, sizeof(struct gre_h));
406 gh->gi_ptype = htons(etype);
409 gh->gi_pr = sc->g_proto;
410 if (sc->g_proto != IPPROTO_MOBILE) {
411 gh->gi_src = sc->g_src;
412 gh->gi_dst = sc->g_dst;
413 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2;
414 ((struct ip*)gh)->ip_ttl = GRE_TTL;
415 ((struct ip*)gh)->ip_tos = ip->ip_tos;
416 ((struct ip*)gh)->ip_id = ip->ip_id;
417 gh->gi_len = m->m_pkthdr.len;
420 IFNET_STAT_INC(ifp, opackets, 1);
421 IFNET_STAT_INC(ifp, obytes, m->m_pkthdr.len);
423 error = ip_output(m, NULL, ro, IP_DEBUGROUTE, NULL, NULL);
427 IFNET_STAT_INC(ifp, oerrors, 1);
432 gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
435 struct ifaltq_subque *ifsq = ifq_get_subq_default(&ifp->if_snd);
438 ifsq_serialize_hw(ifsq);
439 error = gre_output_serialized(ifp, m, dst, rt);
440 ifsq_deserialize_hw(ifsq);
446 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
448 struct ifreq *ifr = (struct ifreq *)data;
449 struct if_laddrreq *lifr = (struct if_laddrreq *)data;
450 struct in_aliasreq *aifr = (struct in_aliasreq *)data;
451 struct gre_softc *sc = ifp->if_softc;
452 struct sockaddr_in si;
453 struct sockaddr *sa = NULL;
455 struct sockaddr_in sp, sm, dp, dm;
462 ifp->if_flags |= IFF_UP;
467 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
469 if ((ifr->ifr_flags & IFF_LINK0) != 0)
470 sc->g_proto = IPPROTO_GRE;
472 sc->g_proto = IPPROTO_MOBILE;
475 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
477 if (ifr->ifr_mtu < 576) {
481 ifp->if_mtu = ifr->ifr_mtu;
484 ifr->ifr_mtu = sc->sc_if.if_mtu;
488 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
491 error = EAFNOSUPPORT;
494 switch (ifr->ifr_addr.sa_family) {
500 error = EAFNOSUPPORT;
505 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
507 sc->g_proto = ifr->ifr_flags;
508 switch (sc->g_proto) {
510 ifp->if_flags |= IFF_LINK0;
513 ifp->if_flags &= ~IFF_LINK0;
516 error = EPROTONOSUPPORT;
521 ifr->ifr_flags = sc->g_proto;
525 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
528 * set tunnel endpoints, compute a less specific route
529 * to the remote end and mark if as up
532 if (cmd == GRESADDRS)
533 sc->g_src = (satosin(sa))->sin_addr;
534 if (cmd == GRESADDRD)
535 sc->g_dst = (satosin(sa))->sin_addr;
538 if (sc->encap != NULL) {
539 encap_detach(sc->encap);
543 if ((sc->g_src.s_addr != INADDR_ANY) &&
544 (sc->g_dst.s_addr != INADDR_ANY)) {
545 bzero(&sp, sizeof(sp));
546 bzero(&sm, sizeof(sm));
547 bzero(&dp, sizeof(dp));
548 bzero(&dm, sizeof(dm));
549 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len =
550 sizeof(struct sockaddr_in);
551 sp.sin_family = sm.sin_family = dp.sin_family =
552 dm.sin_family = AF_INET;
553 sp.sin_addr = sc->g_src;
554 dp.sin_addr = sc->g_dst;
555 sm.sin_addr.s_addr = dm.sin_addr.s_addr =
558 sc->encap = encap_attach(AF_INET, sc->g_proto,
559 sintosa(&sp), sintosa(&sm), sintosa(&dp),
560 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ?
561 &in_gre_protosw : &in_mobile_protosw, sc);
562 if (sc->encap == NULL)
563 kprintf("%s: unable to attach encap\n",
564 if_name(&sc->sc_if));
566 ifnet_deserialize_all(ifp);
567 error = gre_check_route(sc);
568 ifnet_serialize_all(ifp);
570 ifp->if_flags |= IFF_RUNNING;
572 ifp->if_flags &= ~IFF_RUNNING;
576 memset(&si, 0, sizeof(si));
577 si.sin_family = AF_INET;
578 si.sin_len = sizeof(struct sockaddr_in);
579 si.sin_addr.s_addr = sc->g_src.s_addr;
584 memset(&si, 0, sizeof(si));
585 si.sin_family = AF_INET;
586 si.sin_len = sizeof(struct sockaddr_in);
587 si.sin_addr.s_addr = sc->g_dst.s_addr;
592 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
594 if (aifr->ifra_addr.sin_family != AF_INET ||
595 aifr->ifra_dstaddr.sin_family != AF_INET) {
596 error = EAFNOSUPPORT;
599 if (aifr->ifra_addr.sin_len != sizeof(si) ||
600 aifr->ifra_dstaddr.sin_len != sizeof(si)) {
604 sc->g_src = aifr->ifra_addr.sin_addr;
605 sc->g_dst = aifr->ifra_dstaddr.sin_addr;
607 case SIOCSLIFPHYADDR:
608 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
610 if (lifr->addr.ss_family != AF_INET ||
611 lifr->dstaddr.ss_family != AF_INET) {
612 error = EAFNOSUPPORT;
615 if (lifr->addr.ss_len != sizeof(si) ||
616 lifr->dstaddr.ss_len != sizeof(si)) {
620 sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr;
622 (satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr;
625 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
627 sc->g_src.s_addr = INADDR_ANY;
628 sc->g_dst.s_addr = INADDR_ANY;
630 case SIOCGLIFPHYADDR:
631 if (sc->g_src.s_addr == INADDR_ANY ||
632 sc->g_dst.s_addr == INADDR_ANY) {
633 error = EADDRNOTAVAIL;
636 memset(&si, 0, sizeof(si));
637 si.sin_family = AF_INET;
638 si.sin_len = sizeof(struct sockaddr_in);
639 si.sin_addr.s_addr = sc->g_src.s_addr;
640 memcpy(&lifr->addr, &si, sizeof(si));
641 si.sin_addr.s_addr = sc->g_dst.s_addr;
642 memcpy(&lifr->dstaddr, &si, sizeof(si));
644 case SIOCGIFPSRCADDR:
645 if (sc->g_src.s_addr == INADDR_ANY) {
646 error = EADDRNOTAVAIL;
649 memset(&si, 0, sizeof(si));
650 si.sin_family = AF_INET;
651 si.sin_len = sizeof(struct sockaddr_in);
652 si.sin_addr.s_addr = sc->g_src.s_addr;
653 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
655 case SIOCGIFPDSTADDR:
656 if (sc->g_dst.s_addr == INADDR_ANY) {
657 error = EADDRNOTAVAIL;
660 memset(&si, 0, sizeof(si));
661 si.sin_family = AF_INET;
662 si.sin_len = sizeof(struct sockaddr_in);
663 si.sin_addr.s_addr = sc->g_dst.s_addr;
664 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
676 * computes a route to our destination that is not the one
677 * which would be taken by ip_output(), as this one will loop back to
678 * us. If the interface is p2p as a--->b, then a routing entry exists
679 * If we now send a packet to b (e.g. ping b), this will come down here
680 * gets src=a, dst=b tacked on and would from ip_ouput() sent back to
682 * Goal here is to compute a route to b that is less specific than
683 * a-->b. We know that this one exists as in normal operation we have
684 * at least a default route which matches.
687 gre_compute_route(struct gre_softc *sc, struct route *ro)
690 char abuf[INET_ADDRSTRLEN];
694 ASSERT_NETISR_NCPUS(mycpuid);
695 KASSERT(ro == &sc->route_pcpu[mycpuid], ("route mismatch"));
696 KASSERT(ro->ro_rt == NULL, ("rtentry not freed"));
698 memset(ro, 0, sizeof(struct route));
699 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
700 ro->ro_dst.sa_family = AF_INET;
701 ro->ro_dst.sa_len = sizeof(ro->ro_dst);
704 * toggle last bit, so our interface is not found, but a less
705 * specific route. I'd rather like to specify a shorter mask,
706 * but this is not possible. Should work though. XXX
707 * there is a simpler way ...
709 if ((sc->sc_if.if_flags & IFF_LINK1) == 0) {
710 a = ntohl(sc->g_dst.s_addr);
715 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr
720 kprintf("%s: searching a route to %s", if_name(&sc->sc_if),
721 kinet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr, abuf));
727 * check if this returned a route at all and this route is no
728 * recursion to ourself
730 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) {
732 if (ro->ro_rt == NULL)
733 kprintf(" - no route found!\n");
735 kprintf(" - route loops back to ourself!\n");
737 return EADDRNOTAVAIL;
741 * now change it back - else ip_output will just drop
742 * the route and search one to this interface ...
744 if ((sc->sc_if.if_flags & IFF_LINK1) == 0)
745 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
748 kprintf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp),
750 ((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr, abuf));
758 gre_check_route_handler(netmsg_t msg)
760 struct gre_softc *sc = msg->base.lmsg.u.ms_resultp;
766 ro = &sc->route_pcpu[mycpuid];
767 if (ro->ro_rt != NULL) {
771 error = gre_compute_route(sc, ro);
773 netisr_replymsg(&msg->base, error);
777 gre_check_route(struct gre_softc *sc)
779 struct netmsg_base msg;
781 netmsg_init(&msg, NULL, &curthread->td_msgport, MSGF_PRIORITY,
782 gre_check_route_handler);
783 msg.lmsg.u.ms_resultp = sc;
785 return (netisr_domsg(&msg, 0));
789 * do a checksum of a buffer - much like in_cksum, which operates on
793 gre_in_cksum(u_short *p, u_int len)
796 int nwords = len >> 1;
798 while (nwords-- != 0)
806 u.c[0] = *(u_char *)p;
811 /* end-around-carry */
812 sum = (sum >> 16) + (sum & 0xffff);
818 gremodevent(module_t mod, int type, void *data)
826 if_clone_detach(&gre_cloner);
828 while (!LIST_EMPTY(&gre_softc_list))
829 gre_clone_destroy(&LIST_FIRST(&gre_softc_list)->sc_if);
836 static moduledata_t gre_mod = {
842 DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
843 MODULE_VERSION(if_gre, 1);