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 1.22 2008/10/27 02:56:30 sephe 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>
57 #include <sys/malloc.h>
61 #include <sys/protosw.h>
62 #include <sys/socket.h>
63 #include <sys/sockio.h>
64 #include <sys/sysctl.h>
65 #include <sys/systm.h>
66 #include <sys/thread2.h>
68 #include <net/ethernet.h>
70 #include <net/if_types.h>
71 #include <net/route.h>
72 #include <net/if_clone.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);
115 static void greattach(void);
119 extern struct domain inetdomain;
121 static const struct protosw in_gre_protosw =
124 .pr_domain = &inetdomain,
125 .pr_protocol = IPPROTO_GRE,
126 .pr_flags = PR_ATOMIC|PR_ADDR,
128 .pr_input = gre_input,
129 .pr_output = rip_output,
130 .pr_ctlinput = rip_ctlinput,
131 .pr_ctloutput = rip_ctloutput,
133 .pr_ctlport = cpu0_ctlport,
134 .pr_usrreqs = &rip_usrreqs
137 static const struct protosw in_mobile_protosw =
140 .pr_domain = &inetdomain,
141 .pr_protocol = IPPROTO_MOBILE,
142 .pr_flags = PR_ATOMIC|PR_ADDR,
144 .pr_input = gre_mobile_input,
145 .pr_output = rip_output,
146 .pr_ctlinput = rip_ctlinput,
147 .pr_ctloutput = rip_ctloutput,
149 .pr_ctlport = cpu0_ctlport,
150 .pr_usrreqs = &rip_usrreqs
155 SYSCTL_DECL(_net_link);
156 SYSCTL_NODE(_net_link, IFT_OTHER, gre, CTLFLAG_RW, 0,
157 "Generic Routing Encapsulation");
160 * This macro controls the default upper limitation on nesting of gre tunnels.
161 * Since, setting a large value to this macro with a careless configuration
162 * may introduce system crash, we don't allow any nestings by default.
163 * If you need to configure nested gre tunnels, you can define this macro
164 * in your kernel configuration file. However, if you do so, please be
165 * careful to configure the tunnels so that it won't make a loop.
167 #define MAX_GRE_NEST 1
169 static int max_gre_nesting = MAX_GRE_NEST;
170 SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW,
171 &max_gre_nesting, 0, "Max nested tunnels");
178 LIST_INIT(&gre_softc_list);
179 if_clone_attach(&gre_cloner);
183 gre_clone_create(struct if_clone *ifc, int unit, caddr_t param __unused)
185 struct gre_softc *sc;
187 sc = kmalloc(sizeof(struct gre_softc), M_GRE, M_WAITOK);
188 memset(sc, 0, sizeof(struct gre_softc));
190 sc->sc_if.if_softc = sc;
191 if_initname(&(sc->sc_if), GRENAME, 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;
205 if_attach(&sc->sc_if, NULL);
206 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int32_t));
207 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list);
212 gre_clone_destroy(struct ifnet *ifp)
214 struct gre_softc *sc = ifp->if_softc;
217 if (sc->encap != NULL)
218 encap_detach(sc->encap);
220 LIST_REMOVE(sc, sc_list);
230 * The output routine. Takes a packet and encapsulates it in the protocol
231 * given by sc->g_proto. See also RFC 1701 and RFC 2004
234 gre_output_serialized(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
238 struct gre_softc *sc = ifp->if_softc;
243 struct mobile_h mob_h;
246 * gre may cause infinite recursion calls when misconfigured.
247 * We'll prevent this by introducing upper limit.
249 if (++(sc->called) > max_gre_nesting) {
250 kprintf("%s: gre_output: recursively called too many "
251 "times(%d)\n", if_name(&sc->sc_if), sc->called);
253 error = EIO; /* is there better errno? */
257 if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) == 0 ||
258 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) {
269 uint32_t af = dst->sa_family;
271 bpf_ptap(ifp->if_bpf, m, &af, sizeof(af));
274 m->m_flags &= ~(M_BCAST|M_MCAST);
276 if (sc->g_proto == IPPROTO_MOBILE) {
277 if (dst->sa_family == AF_INET) {
281 ip = mtod(m, struct ip *);
284 * RFC2004 specifies that fragmented datagrams shouldn't
287 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
288 IF_DROP(&ifp->if_snd);
290 error = EINVAL; /* is there better errno? */
293 memset(&mob_h, 0, MOB_H_SIZ_L);
294 mob_h.proto = (ip->ip_p) << 8;
295 mob_h.odst = ip->ip_dst.s_addr;
296 ip->ip_dst.s_addr = sc->g_dst.s_addr;
299 * If the packet comes from our host, we only change
300 * the destination address in the IP header.
301 * Else we also need to save and change the source
303 if (in_hosteq(ip->ip_src, sc->g_src)) {
306 mob_h.proto |= MOB_H_SBIT;
307 mob_h.osrc = ip->ip_src.s_addr;
308 ip->ip_src.s_addr = sc->g_src.s_addr;
311 mob_h.proto = htons(mob_h.proto);
312 mob_h.hcrc = gre_in_cksum((u_short *)&mob_h, msiz);
314 if ((m->m_data - msiz) < m->m_pktdat) {
316 MGETHDR(m0, MB_DONTWAIT, MT_HEADER);
318 IF_DROP(&ifp->if_snd);
324 m->m_data += sizeof(struct ip);
325 m->m_len -= sizeof(struct ip);
326 m0->m_pkthdr.len = m->m_pkthdr.len + msiz;
327 m0->m_len = msiz + sizeof(struct ip);
328 m0->m_data += max_linkhdr;
329 memcpy(mtod(m0, caddr_t), (caddr_t)ip,
332 } else { /* we have some space left in the old one */
335 m->m_pkthdr.len += msiz;
336 bcopy(ip, mtod(m, caddr_t),
339 ip = mtod(m, struct ip *);
340 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz);
341 ip->ip_len = ntohs(ip->ip_len) + msiz;
342 } else { /* AF_INET */
343 IF_DROP(&ifp->if_snd);
348 } else if (sc->g_proto == IPPROTO_GRE) {
349 switch (dst->sa_family) {
351 ip = mtod(m, struct ip *);
352 etype = ETHERTYPE_IP;
356 etype = ETHERTYPE_ATALK;
361 etype = ETHERTYPE_NS;
365 IF_DROP(&ifp->if_snd);
367 error = EAFNOSUPPORT;
370 M_PREPEND(m, sizeof(struct greip), MB_DONTWAIT);
372 IF_DROP(&ifp->if_snd);
378 if (m == NULL) { /* impossible */
379 IF_DROP(&ifp->if_snd);
384 gh = mtod(m, struct greip *);
385 if (sc->g_proto == IPPROTO_GRE) {
386 /* we don't have any GRE flags for now */
388 memset((void *)&gh->gi_g, 0, sizeof(struct gre_h));
389 gh->gi_ptype = htons(etype);
392 gh->gi_pr = sc->g_proto;
393 if (sc->g_proto != IPPROTO_MOBILE) {
394 gh->gi_src = sc->g_src;
395 gh->gi_dst = sc->g_dst;
396 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2;
397 ((struct ip*)gh)->ip_ttl = GRE_TTL;
398 ((struct ip*)gh)->ip_tos = ip->ip_tos;
399 ((struct ip*)gh)->ip_id = ip->ip_id;
400 gh->gi_len = m->m_pkthdr.len;
404 ifp->if_obytes += m->m_pkthdr.len;
406 error = ip_output(m, NULL, &sc->route, 0, NULL, NULL);
415 gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
420 ifnet_serialize_tx(ifp);
421 error = gre_output_serialized(ifp, m, dst, rt);
422 ifnet_deserialize_tx(ifp);
428 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
430 struct ifreq *ifr = (struct ifreq *)data;
431 struct if_laddrreq *lifr = (struct if_laddrreq *)data;
432 struct in_aliasreq *aifr = (struct in_aliasreq *)data;
433 struct gre_softc *sc = ifp->if_softc;
434 struct sockaddr_in si;
435 struct sockaddr *sa = NULL;
437 struct sockaddr_in sp, sm, dp, dm;
444 ifp->if_flags |= IFF_UP;
449 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
451 if ((ifr->ifr_flags & IFF_LINK0) != 0)
452 sc->g_proto = IPPROTO_GRE;
454 sc->g_proto = IPPROTO_MOBILE;
457 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
459 if (ifr->ifr_mtu < 576) {
463 ifp->if_mtu = ifr->ifr_mtu;
466 ifr->ifr_mtu = sc->sc_if.if_mtu;
470 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
473 error = EAFNOSUPPORT;
476 switch (ifr->ifr_addr.sa_family) {
482 error = EAFNOSUPPORT;
487 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
489 sc->g_proto = ifr->ifr_flags;
490 switch (sc->g_proto) {
492 ifp->if_flags |= IFF_LINK0;
495 ifp->if_flags &= ~IFF_LINK0;
498 error = EPROTONOSUPPORT;
503 ifr->ifr_flags = sc->g_proto;
507 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
510 * set tunnel endpoints, compute a less specific route
511 * to the remote end and mark if as up
514 if (cmd == GRESADDRS)
515 sc->g_src = (satosin(sa))->sin_addr;
516 if (cmd == GRESADDRD)
517 sc->g_dst = (satosin(sa))->sin_addr;
520 if (sc->encap != NULL) {
521 encap_detach(sc->encap);
525 if ((sc->g_src.s_addr != INADDR_ANY) &&
526 (sc->g_dst.s_addr != INADDR_ANY)) {
527 bzero(&sp, sizeof(sp));
528 bzero(&sm, sizeof(sm));
529 bzero(&dp, sizeof(dp));
530 bzero(&dm, sizeof(dm));
531 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len =
532 sizeof(struct sockaddr_in);
533 sp.sin_family = sm.sin_family = dp.sin_family =
534 dm.sin_family = AF_INET;
535 sp.sin_addr = sc->g_src;
536 dp.sin_addr = sc->g_dst;
537 sm.sin_addr.s_addr = dm.sin_addr.s_addr =
540 sc->encap = encap_attach(AF_INET, sc->g_proto,
541 sintosa(&sp), sintosa(&sm), sintosa(&dp),
542 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ?
543 &in_gre_protosw : &in_mobile_protosw, sc);
544 if (sc->encap == NULL)
545 kprintf("%s: unable to attach encap\n",
546 if_name(&sc->sc_if));
548 if (sc->route.ro_rt != 0) /* free old route */
549 RTFREE(sc->route.ro_rt);
550 if (gre_compute_route(sc) == 0)
551 ifp->if_flags |= IFF_RUNNING;
553 ifp->if_flags &= ~IFF_RUNNING;
557 memset(&si, 0, sizeof(si));
558 si.sin_family = AF_INET;
559 si.sin_len = sizeof(struct sockaddr_in);
560 si.sin_addr.s_addr = sc->g_src.s_addr;
565 memset(&si, 0, sizeof(si));
566 si.sin_family = AF_INET;
567 si.sin_len = sizeof(struct sockaddr_in);
568 si.sin_addr.s_addr = sc->g_dst.s_addr;
573 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
575 if (aifr->ifra_addr.sin_family != AF_INET ||
576 aifr->ifra_dstaddr.sin_family != AF_INET) {
577 error = EAFNOSUPPORT;
580 if (aifr->ifra_addr.sin_len != sizeof(si) ||
581 aifr->ifra_dstaddr.sin_len != sizeof(si)) {
585 sc->g_src = aifr->ifra_addr.sin_addr;
586 sc->g_dst = aifr->ifra_dstaddr.sin_addr;
588 case SIOCSLIFPHYADDR:
589 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
591 if (lifr->addr.ss_family != AF_INET ||
592 lifr->dstaddr.ss_family != AF_INET) {
593 error = EAFNOSUPPORT;
596 if (lifr->addr.ss_len != sizeof(si) ||
597 lifr->dstaddr.ss_len != sizeof(si)) {
601 sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr;
603 (satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr;
606 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
608 sc->g_src.s_addr = INADDR_ANY;
609 sc->g_dst.s_addr = INADDR_ANY;
611 case SIOCGLIFPHYADDR:
612 if (sc->g_src.s_addr == INADDR_ANY ||
613 sc->g_dst.s_addr == INADDR_ANY) {
614 error = EADDRNOTAVAIL;
617 memset(&si, 0, sizeof(si));
618 si.sin_family = AF_INET;
619 si.sin_len = sizeof(struct sockaddr_in);
620 si.sin_addr.s_addr = sc->g_src.s_addr;
621 memcpy(&lifr->addr, &si, sizeof(si));
622 si.sin_addr.s_addr = sc->g_dst.s_addr;
623 memcpy(&lifr->dstaddr, &si, sizeof(si));
625 case SIOCGIFPSRCADDR:
626 if (sc->g_src.s_addr == INADDR_ANY) {
627 error = EADDRNOTAVAIL;
630 memset(&si, 0, sizeof(si));
631 si.sin_family = AF_INET;
632 si.sin_len = sizeof(struct sockaddr_in);
633 si.sin_addr.s_addr = sc->g_src.s_addr;
634 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
636 case SIOCGIFPDSTADDR:
637 if (sc->g_dst.s_addr == INADDR_ANY) {
638 error = EADDRNOTAVAIL;
641 memset(&si, 0, sizeof(si));
642 si.sin_family = AF_INET;
643 si.sin_len = sizeof(struct sockaddr_in);
644 si.sin_addr.s_addr = sc->g_dst.s_addr;
645 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
657 * computes a route to our destination that is not the one
658 * which would be taken by ip_output(), as this one will loop back to
659 * us. If the interface is p2p as a--->b, then a routing entry exists
660 * If we now send a packet to b (e.g. ping b), this will come down here
661 * gets src=a, dst=b tacked on and would from ip_ouput() sent back to
663 * Goal here is to compute a route to b that is less specific than
664 * a-->b. We know that this one exists as in normal operation we have
665 * at least a default route which matches.
668 gre_compute_route(struct gre_softc *sc)
675 memset(ro, 0, sizeof(struct route));
676 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
677 ro->ro_dst.sa_family = AF_INET;
678 ro->ro_dst.sa_len = sizeof(ro->ro_dst);
681 * toggle last bit, so our interface is not found, but a less
682 * specific route. I'd rather like to specify a shorter mask,
683 * but this is not possible. Should work though. XXX
684 * there is a simpler way ...
686 if ((sc->sc_if.if_flags & IFF_LINK1) == 0) {
687 a = ntohl(sc->g_dst.s_addr);
692 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr
697 kprintf("%s: searching a route to %s", if_name(&sc->sc_if),
698 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr));
704 * check if this returned a route at all and this route is no
705 * recursion to ourself
707 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) {
709 if (ro->ro_rt == NULL)
710 kprintf(" - no route found!\n");
712 kprintf(" - route loops back to ourself!\n");
714 return EADDRNOTAVAIL;
718 * now change it back - else ip_output will just drop
719 * the route and search one to this interface ...
721 if ((sc->sc_if.if_flags & IFF_LINK1) == 0)
722 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
725 kprintf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp),
726 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr));
734 * do a checksum of a buffer - much like in_cksum, which operates on
738 gre_in_cksum(u_short *p, u_int len)
741 int nwords = len >> 1;
743 while (nwords-- != 0)
751 u.c[0] = *(u_char *)p;
756 /* end-around-carry */
757 sum = (sum >> 16) + (sum & 0xffff);
763 gremodevent(module_t mod, int type, void *data)
771 if_clone_detach(&gre_cloner);
773 while (!LIST_EMPTY(&gre_softc_list))
774 gre_clone_destroy(&LIST_FIRST(&gre_softc_list)->sc_if);
781 static moduledata_t gre_mod = {
787 DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
788 MODULE_VERSION(if_gre, 1);