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 $ */
3 /* $DragonFly: src/sys/net/gre/if_gre.c,v 1.4 2003/06/25 03:56:02 dillon Exp $ */
6 * Copyright (c) 1998 The NetBSD Foundation, Inc.
9 * This code is derived from software contributed to The NetBSD Foundation
10 * by Heiko W.Rupp <hwr@pilhuhn.de>
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 * must display the following acknowledgement:
22 * This product includes software developed by the NetBSD
23 * Foundation, Inc. and its contributors.
24 * 4. Neither the name of The NetBSD Foundation nor the names of its
25 * contributors may be used to endorse or promote products derived
26 * from this software without specific prior written permission.
28 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
29 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
30 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
31 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
32 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
33 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
34 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
35 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
36 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
37 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGE.
42 * Encapsulate L3 protocols into IP
43 * See RFC 1701 and 1702 for more details.
44 * If_gre is compatible with Cisco GRE tunnels, so you can
45 * have a NetBSD box as the other end of a tunnel interface of a Cisco
46 * router. See gre(4) for more details.
47 * Also supported: IP in IP encaps (proto 55) as of RFC 2004
50 #include "opt_atalk.h"
54 #include <sys/param.h>
55 #include <sys/kernel.h>
56 #include <sys/malloc.h>
59 #include <sys/protosw.h>
60 #include <machine/bus.h>
62 #include <sys/socket.h>
63 #include <sys/sockio.h>
64 #include <sys/sysctl.h>
65 #include <sys/systm.h>
67 #include <net/ethernet.h>
69 #include <net/if_types.h>
70 #include <net/route.h>
73 #include <netinet/in.h>
74 #include <netinet/in_systm.h>
75 #include <netinet/in_var.h>
76 #include <netinet/ip.h>
77 #include <netinet/ip_gre.h>
78 #include <netinet/ip_var.h>
79 #include <netinet/ip_encap.h>
81 #error "Huh? if_gre without inet?"
86 #include <net/net_osdep.h>
87 #include <net/if_gre.h>
90 * It is not easy to calculate the right value for a GRE MTU.
91 * We leave this task to the admin and use the same default that
97 #define GRE_MAXUNIT 0x7fff
99 static MALLOC_DEFINE(M_GRE, GRENAME, "Generic Routing Encapsulation");
100 static struct rman greunits[1];
102 struct gre_softc_head gre_softc_list;
104 static int gre_clone_create(struct if_clone *, int *);
105 static void gre_clone_destroy(struct ifnet *);
106 static int gre_ioctl(struct ifnet *, u_long, caddr_t);
107 static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *,
110 static struct if_clone gre_cloner =
111 IF_CLONE_INITIALIZER("gre", gre_clone_create, gre_clone_destroy);
113 static int gre_compute_route(struct gre_softc *sc);
115 static void greattach(void);
118 extern struct domain inetdomain;
119 static const struct protosw in_gre_protosw =
120 { SOCK_RAW, &inetdomain, IPPROTO_GRE, PR_ATOMIC|PR_ADDR,
121 gre_input, rip_output, rip_ctlinput, rip_ctloutput,
126 static const struct protosw in_mobile_protosw =
127 { SOCK_RAW, &inetdomain, IPPROTO_MOBILE, PR_ATOMIC|PR_ADDR,
128 gre_mobile_input, rip_output, rip_ctlinput, rip_ctloutput,
135 SYSCTL_DECL(_net_link);
136 SYSCTL_NODE(_net_link, IFT_OTHER, gre, CTLFLAG_RW, 0,
137 "Generic Routing Encapsulation");
140 * This macro controls the default upper limitation on nesting of gre tunnels.
141 * Since, setting a large value to this macro with a careless configuration
142 * may introduce system crash, we don't allow any nestings by default.
143 * If you need to configure nested gre tunnels, you can define this macro
144 * in your kernel configuration file. However, if you do so, please be
145 * careful to configure the tunnels so that it won't make a loop.
147 #define MAX_GRE_NEST 1
149 static int max_gre_nesting = MAX_GRE_NEST;
150 SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW,
151 &max_gre_nesting, 0, "Max nested tunnels");
158 LIST_INIT(&gre_softc_list);
159 if_clone_attach(&gre_cloner);
163 gre_clone_create(ifc, unit)
164 struct if_clone *ifc;
168 struct gre_softc *sc;
170 if (*unit > GRE_MAXUNIT)
174 r = rman_reserve_resource(greunits, 0, GRE_MAXUNIT, 1,
175 RF_ALLOCATED | RF_ACTIVE, NULL);
178 *unit = rman_get_start(r);
180 r = rman_reserve_resource(greunits, *unit, *unit, 1,
181 RF_ALLOCATED | RF_ACTIVE, NULL);
186 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK);
187 memset(sc, 0, sizeof(struct gre_softc));
189 sc->sc_if.if_name = GRENAME;
190 sc->sc_if.if_softc = sc;
191 sc->sc_if.if_unit = *unit;
192 sc->sc_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
193 sc->sc_if.if_type = IFT_OTHER;
194 sc->sc_if.if_addrlen = 0;
195 sc->sc_if.if_hdrlen = 24; /* IP + GRE */
196 sc->sc_if.if_mtu = GREMTU;
197 sc->sc_if.if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
198 sc->sc_if.if_output = gre_output;
199 sc->sc_if.if_ioctl = gre_ioctl;
200 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY;
201 sc->g_proto = IPPROTO_GRE;
202 sc->sc_if.if_flags |= IFF_LINK0;
206 if_attach(&sc->sc_if);
207 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int32_t));
208 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list);
213 gre_clone_destroy(ifp)
217 struct gre_softc *sc = ifp->if_softc;
220 if (sc->encap != NULL)
221 encap_detach(sc->encap);
223 LIST_REMOVE(sc, sc_list);
227 err = rman_release_resource(sc->r_unit);
228 KASSERT(err == 0, ("Unexpected error freeing resource"));
234 * The output routine. Takes a packet and encapsulates it in the protocol
235 * given by sc->g_proto. See also RFC 1701 and RFC 2004
238 gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
242 struct gre_softc *sc = ifp->if_softc;
247 struct mobile_h mob_h;
250 * gre may cause infinite recursion calls when misconfigured.
251 * We'll prevent this by introducing upper limit.
253 if (++(sc->called) > max_gre_nesting) {
254 printf("%s: gre_output: recursively called too many "
255 "times(%d)\n", if_name(&sc->sc_if), sc->called);
257 error = EIO; /* is there better errno? */
261 if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) == 0 ||
262 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) {
273 /* see comment of other if_foo.c files */
275 u_int32_t af = dst->sa_family;
279 m0.m_data = (char *)⁡
284 m->m_flags &= ~(M_BCAST|M_MCAST);
286 if (sc->g_proto == IPPROTO_MOBILE) {
287 if (dst->sa_family == AF_INET) {
291 ip = mtod(m, struct ip *);
294 * RFC2004 specifies that fragmented diagrams shouldn't
297 if ((ip->ip_off & IP_MF) != 0) {
298 IF_DROP(&ifp->if_snd);
300 error = EINVAL; /* is there better errno? */
303 memset(&mob_h, 0, MOB_H_SIZ_L);
304 mob_h.proto = (ip->ip_p) << 8;
305 mob_h.odst = ip->ip_dst.s_addr;
306 ip->ip_dst.s_addr = sc->g_dst.s_addr;
309 * If the packet comes from our host, we only change
310 * the destination address in the IP header.
311 * Else we also need to save and change the source
313 if (in_hosteq(ip->ip_src, sc->g_src)) {
316 mob_h.proto |= MOB_H_SBIT;
317 mob_h.osrc = ip->ip_src.s_addr;
318 ip->ip_src.s_addr = sc->g_src.s_addr;
321 mob_h.proto = htons(mob_h.proto);
322 mob_h.hcrc = gre_in_cksum((u_short *)&mob_h, msiz);
324 if ((m->m_data - msiz) < m->m_pktdat) {
326 MGETHDR(m0, M_DONTWAIT, MT_HEADER);
328 IF_DROP(&ifp->if_snd);
334 m->m_data += sizeof(struct ip);
335 m->m_len -= sizeof(struct ip);
336 m0->m_pkthdr.len = m->m_pkthdr.len + msiz;
337 m0->m_len = msiz + sizeof(struct ip);
338 m0->m_data += max_linkhdr;
339 memcpy(mtod(m0, caddr_t), (caddr_t)ip,
342 } else { /* we have some space left in the old one */
345 m->m_pkthdr.len += msiz;
346 bcopy(ip, mtod(m, caddr_t),
349 ip = mtod(m, struct ip *);
350 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz);
351 ip->ip_len = ntohs(ip->ip_len) + msiz;
352 } else { /* AF_INET */
353 IF_DROP(&ifp->if_snd);
358 } else if (sc->g_proto == IPPROTO_GRE) {
359 switch (dst->sa_family) {
361 ip = mtod(m, struct ip *);
362 etype = ETHERTYPE_IP;
366 etype = ETHERTYPE_ATALK;
371 etype = ETHERTYPE_NS;
375 IF_DROP(&ifp->if_snd);
377 error = EAFNOSUPPORT;
380 M_PREPEND(m, sizeof(struct greip), M_DONTWAIT);
382 IF_DROP(&ifp->if_snd);
388 if (m == NULL) { /* impossible */
389 IF_DROP(&ifp->if_snd);
394 gh = mtod(m, struct greip *);
395 if (sc->g_proto == IPPROTO_GRE) {
396 /* we don't have any GRE flags for now */
398 memset((void *)&gh->gi_g, 0, sizeof(struct gre_h));
399 gh->gi_ptype = htons(etype);
402 gh->gi_pr = sc->g_proto;
403 if (sc->g_proto != IPPROTO_MOBILE) {
404 gh->gi_src = sc->g_src;
405 gh->gi_dst = sc->g_dst;
406 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2;
407 ((struct ip*)gh)->ip_ttl = GRE_TTL;
408 ((struct ip*)gh)->ip_tos = ip->ip_tos;
409 ((struct ip*)gh)->ip_id = ip->ip_id;
410 gh->gi_len = m->m_pkthdr.len;
414 ifp->if_obytes += m->m_pkthdr.len;
416 error = ip_output(m, NULL, &sc->route, 0, NULL, NULL);
425 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
427 struct ifreq *ifr = (struct ifreq *)data;
428 struct if_laddrreq *lifr = (struct if_laddrreq *)data;
429 struct in_aliasreq *aifr = (struct in_aliasreq *)data;
430 struct gre_softc *sc = ifp->if_softc;
432 struct sockaddr_in si;
433 struct sockaddr *sa = NULL;
435 struct sockaddr_in sp, sm, dp, dm;
436 struct thread *td = curthread;
443 ifp->if_flags |= IFF_UP;
448 if ((error = suser(td)) != 0)
450 if ((ifr->ifr_flags & IFF_LINK0) != 0)
451 sc->g_proto = IPPROTO_GRE;
453 sc->g_proto = IPPROTO_MOBILE;
456 if ((error = suser(td)) != 0)
458 if (ifr->ifr_mtu < 576) {
462 ifp->if_mtu = ifr->ifr_mtu;
465 ifr->ifr_mtu = sc->sc_if.if_mtu;
469 if ((error = suser(td)) != 0)
472 error = EAFNOSUPPORT;
475 switch (ifr->ifr_addr.sa_family) {
481 error = EAFNOSUPPORT;
486 if ((error = suser(td)) != 0)
488 sc->g_proto = ifr->ifr_flags;
489 switch (sc->g_proto) {
491 ifp->if_flags |= IFF_LINK0;
494 ifp->if_flags &= ~IFF_LINK0;
497 error = EPROTONOSUPPORT;
502 ifr->ifr_flags = sc->g_proto;
506 if ((error = suser(td)) != 0)
509 * set tunnel endpoints, compute a less specific route
510 * to the remote end and mark if as up
513 if (cmd == GRESADDRS)
514 sc->g_src = (satosin(sa))->sin_addr;
515 if (cmd == GRESADDRD)
516 sc->g_dst = (satosin(sa))->sin_addr;
519 if (sc->encap != NULL) {
520 encap_detach(sc->encap);
524 if ((sc->g_src.s_addr != INADDR_ANY) &&
525 (sc->g_dst.s_addr != INADDR_ANY)) {
526 bzero(&sp, sizeof(sp));
527 bzero(&sm, sizeof(sm));
528 bzero(&dp, sizeof(dp));
529 bzero(&dm, sizeof(dm));
530 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len =
531 sizeof(struct sockaddr_in);
532 sp.sin_family = sm.sin_family = dp.sin_family =
533 dm.sin_family = AF_INET;
534 sp.sin_addr = sc->g_src;
535 dp.sin_addr = sc->g_dst;
536 sm.sin_addr.s_addr = dm.sin_addr.s_addr =
539 sc->encap = encap_attach(AF_INET, sc->g_proto,
540 sintosa(&sp), sintosa(&sm), sintosa(&dp),
541 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ?
542 &in_gre_protosw : &in_mobile_protosw, sc);
543 if (sc->encap == NULL)
544 printf("%s: unable to attach encap\n",
545 if_name(&sc->sc_if));
547 if (sc->route.ro_rt != 0) /* free old route */
548 RTFREE(sc->route.ro_rt);
549 if (gre_compute_route(sc) == 0)
550 ifp->if_flags |= IFF_RUNNING;
552 ifp->if_flags &= ~IFF_RUNNING;
556 memset(&si, 0, sizeof(si));
557 si.sin_family = AF_INET;
558 si.sin_len = sizeof(struct sockaddr_in);
559 si.sin_addr.s_addr = sc->g_src.s_addr;
564 memset(&si, 0, sizeof(si));
565 si.sin_family = AF_INET;
566 si.sin_len = sizeof(struct sockaddr_in);
567 si.sin_addr.s_addr = sc->g_dst.s_addr;
572 if ((error = suser(td)) != 0)
574 if (aifr->ifra_addr.sin_family != AF_INET ||
575 aifr->ifra_dstaddr.sin_family != AF_INET) {
576 error = EAFNOSUPPORT;
579 if (aifr->ifra_addr.sin_len != sizeof(si) ||
580 aifr->ifra_dstaddr.sin_len != sizeof(si)) {
584 sc->g_src = aifr->ifra_addr.sin_addr;
585 sc->g_dst = aifr->ifra_dstaddr.sin_addr;
587 case SIOCSLIFPHYADDR:
588 if ((error = suser(td)) != 0)
590 if (lifr->addr.ss_family != AF_INET ||
591 lifr->dstaddr.ss_family != AF_INET) {
592 error = EAFNOSUPPORT;
595 if (lifr->addr.ss_len != sizeof(si) ||
596 lifr->dstaddr.ss_len != sizeof(si)) {
600 sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr;
602 (satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr;
605 if ((error = suser(td)) != 0)
607 sc->g_src.s_addr = INADDR_ANY;
608 sc->g_dst.s_addr = INADDR_ANY;
610 case SIOCGLIFPHYADDR:
611 if (sc->g_src.s_addr == INADDR_ANY ||
612 sc->g_dst.s_addr == INADDR_ANY) {
613 error = EADDRNOTAVAIL;
616 memset(&si, 0, sizeof(si));
617 si.sin_family = AF_INET;
618 si.sin_len = sizeof(struct sockaddr_in);
619 si.sin_addr.s_addr = sc->g_src.s_addr;
620 memcpy(&lifr->addr, &si, sizeof(si));
621 si.sin_addr.s_addr = sc->g_dst.s_addr;
622 memcpy(&lifr->dstaddr, &si, sizeof(si));
624 case SIOCGIFPSRCADDR:
625 if (sc->g_src.s_addr == INADDR_ANY) {
626 error = EADDRNOTAVAIL;
629 memset(&si, 0, sizeof(si));
630 si.sin_family = AF_INET;
631 si.sin_len = sizeof(struct sockaddr_in);
632 si.sin_addr.s_addr = sc->g_src.s_addr;
633 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
635 case SIOCGIFPDSTADDR:
636 if (sc->g_dst.s_addr == INADDR_ANY) {
637 error = EADDRNOTAVAIL;
640 memset(&si, 0, sizeof(si));
641 si.sin_family = AF_INET;
642 si.sin_len = sizeof(struct sockaddr_in);
643 si.sin_addr.s_addr = sc->g_dst.s_addr;
644 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
656 * computes a route to our destination that is not the one
657 * which would be taken by ip_output(), as this one will loop back to
658 * us. If the interface is p2p as a--->b, then a routing entry exists
659 * If we now send a packet to b (e.g. ping b), this will come down here
660 * gets src=a, dst=b tacked on and would from ip_ouput() sent back to
662 * Goal here is to compute a route to b that is less specific than
663 * a-->b. We know that this one exists as in normal operation we have
664 * at least a default route which matches.
667 gre_compute_route(struct gre_softc *sc)
674 memset(ro, 0, sizeof(struct route));
675 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
676 ro->ro_dst.sa_family = AF_INET;
677 ro->ro_dst.sa_len = sizeof(ro->ro_dst);
680 * toggle last bit, so our interface is not found, but a less
681 * specific route. I'd rather like to specify a shorter mask,
682 * but this is not possible. Should work though. XXX
683 * there is a simpler way ...
685 if ((sc->sc_if.if_flags & IFF_LINK1) == 0) {
686 a = ntohl(sc->g_dst.s_addr);
691 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr
696 printf("%s: searching a route to %s", if_name(&sc->sc_if),
697 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr));
703 * check if this returned a route at all and this route is no
704 * recursion to ourself
706 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) {
708 if (ro->ro_rt == NULL)
709 printf(" - no route found!\n");
711 printf(" - route loops back to ourself!\n");
713 return EADDRNOTAVAIL;
717 * now change it back - else ip_output will just drop
718 * the route and search one to this interface ...
720 if ((sc->sc_if.if_flags & IFF_LINK1) == 0)
721 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
724 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp),
725 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr));
733 * do a checksum of a buffer - much like in_cksum, which operates on
737 gre_in_cksum(u_short *p, u_int len)
740 int nwords = len >> 1;
742 while (nwords-- != 0)
750 u.c[0] = *(u_char *)p;
755 /* end-around-carry */
756 sum = (sum >> 16) + (sum & 0xffff);
762 gremodevent(module_t mod, int type, void *data)
768 greunits->rm_type = RMAN_ARRAY;
769 greunits->rm_descr = "configurable if_gre units";
770 err = rman_init(greunits);
773 err = rman_manage_region(greunits, 0, GRE_MAXUNIT);
775 printf("%s: greunits: rman_manage_region: Failed %d\n",
783 if_clone_detach(&gre_cloner);
785 while (!LIST_EMPTY(&gre_softc_list))
786 gre_clone_destroy(&LIST_FIRST(&gre_softc_list)->sc_if);
788 err = rman_fini(greunits);
797 static moduledata_t gre_mod = {
803 DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
804 MODULE_VERSION(if_gre, 1);