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 void 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);
228 * The output routine. Takes a packet and encapsulates it in the protocol
229 * given by sc->g_proto. See also RFC 1701 and RFC 2004
232 gre_output_serialized(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
236 struct gre_softc *sc = ifp->if_softc;
241 struct mobile_h mob_h;
244 * gre may cause infinite recursion calls when misconfigured.
245 * We'll prevent this by introducing upper limit.
247 if (++(sc->called) > max_gre_nesting) {
248 kprintf("%s: gre_output: recursively called too many "
249 "times(%d)\n", if_name(&sc->sc_if), sc->called);
251 error = EIO; /* is there better errno? */
255 if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) == 0 ||
256 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) {
267 uint32_t af = dst->sa_family;
269 bpf_ptap(ifp->if_bpf, m, &af, sizeof(af));
272 m->m_flags &= ~(M_BCAST|M_MCAST);
274 if (sc->g_proto == IPPROTO_MOBILE) {
275 if (dst->sa_family == AF_INET) {
279 ip = mtod(m, struct ip *);
282 * RFC2004 specifies that fragmented datagrams shouldn't
285 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
286 IF_DROP(&ifp->if_snd);
288 error = EINVAL; /* is there better errno? */
291 memset(&mob_h, 0, MOB_H_SIZ_L);
292 mob_h.proto = (ip->ip_p) << 8;
293 mob_h.odst = ip->ip_dst.s_addr;
294 ip->ip_dst.s_addr = sc->g_dst.s_addr;
297 * If the packet comes from our host, we only change
298 * the destination address in the IP header.
299 * Else we also need to save and change the source
301 if (in_hosteq(ip->ip_src, sc->g_src)) {
304 mob_h.proto |= MOB_H_SBIT;
305 mob_h.osrc = ip->ip_src.s_addr;
306 ip->ip_src.s_addr = sc->g_src.s_addr;
309 mob_h.proto = htons(mob_h.proto);
310 mob_h.hcrc = gre_in_cksum((u_short *)&mob_h, msiz);
312 if ((m->m_data - msiz) < m->m_pktdat) {
314 MGETHDR(m0, MB_DONTWAIT, MT_HEADER);
316 IF_DROP(&ifp->if_snd);
322 m->m_data += sizeof(struct ip);
323 m->m_len -= sizeof(struct ip);
324 m0->m_pkthdr.len = m->m_pkthdr.len + msiz;
325 m0->m_len = msiz + sizeof(struct ip);
326 m0->m_data += max_linkhdr;
327 memcpy(mtod(m0, caddr_t), (caddr_t)ip,
330 } else { /* we have some space left in the old one */
333 m->m_pkthdr.len += msiz;
334 bcopy(ip, mtod(m, caddr_t),
337 ip = mtod(m, struct ip *);
338 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz);
339 ip->ip_len = ntohs(ip->ip_len) + msiz;
340 } else { /* AF_INET */
341 IF_DROP(&ifp->if_snd);
346 } else if (sc->g_proto == IPPROTO_GRE) {
347 switch (dst->sa_family) {
349 ip = mtod(m, struct ip *);
350 etype = ETHERTYPE_IP;
354 etype = ETHERTYPE_ATALK;
359 etype = ETHERTYPE_NS;
363 IF_DROP(&ifp->if_snd);
365 error = EAFNOSUPPORT;
368 M_PREPEND(m, sizeof(struct greip), MB_DONTWAIT);
370 IF_DROP(&ifp->if_snd);
376 if (m == NULL) { /* impossible */
377 IF_DROP(&ifp->if_snd);
382 gh = mtod(m, struct greip *);
383 if (sc->g_proto == IPPROTO_GRE) {
384 /* we don't have any GRE flags for now */
386 memset((void *)&gh->gi_g, 0, sizeof(struct gre_h));
387 gh->gi_ptype = htons(etype);
390 gh->gi_pr = sc->g_proto;
391 if (sc->g_proto != IPPROTO_MOBILE) {
392 gh->gi_src = sc->g_src;
393 gh->gi_dst = sc->g_dst;
394 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2;
395 ((struct ip*)gh)->ip_ttl = GRE_TTL;
396 ((struct ip*)gh)->ip_tos = ip->ip_tos;
397 ((struct ip*)gh)->ip_id = ip->ip_id;
398 gh->gi_len = m->m_pkthdr.len;
402 ifp->if_obytes += m->m_pkthdr.len;
404 error = ip_output(m, NULL, &sc->route, 0, NULL, NULL);
413 gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
418 ifnet_serialize_tx(ifp);
419 error = gre_output_serialized(ifp, m, dst, rt);
420 ifnet_deserialize_tx(ifp);
426 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
428 struct ifreq *ifr = (struct ifreq *)data;
429 struct if_laddrreq *lifr = (struct if_laddrreq *)data;
430 struct in_aliasreq *aifr = (struct in_aliasreq *)data;
431 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;
442 ifp->if_flags |= IFF_UP;
447 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
449 if ((ifr->ifr_flags & IFF_LINK0) != 0)
450 sc->g_proto = IPPROTO_GRE;
452 sc->g_proto = IPPROTO_MOBILE;
455 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
457 if (ifr->ifr_mtu < 576) {
461 ifp->if_mtu = ifr->ifr_mtu;
464 ifr->ifr_mtu = sc->sc_if.if_mtu;
468 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
471 error = EAFNOSUPPORT;
474 switch (ifr->ifr_addr.sa_family) {
480 error = EAFNOSUPPORT;
485 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
487 sc->g_proto = ifr->ifr_flags;
488 switch (sc->g_proto) {
490 ifp->if_flags |= IFF_LINK0;
493 ifp->if_flags &= ~IFF_LINK0;
496 error = EPROTONOSUPPORT;
501 ifr->ifr_flags = sc->g_proto;
505 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
508 * set tunnel endpoints, compute a less specific route
509 * to the remote end and mark if as up
512 if (cmd == GRESADDRS)
513 sc->g_src = (satosin(sa))->sin_addr;
514 if (cmd == GRESADDRD)
515 sc->g_dst = (satosin(sa))->sin_addr;
518 if (sc->encap != NULL) {
519 encap_detach(sc->encap);
523 if ((sc->g_src.s_addr != INADDR_ANY) &&
524 (sc->g_dst.s_addr != INADDR_ANY)) {
525 bzero(&sp, sizeof(sp));
526 bzero(&sm, sizeof(sm));
527 bzero(&dp, sizeof(dp));
528 bzero(&dm, sizeof(dm));
529 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len =
530 sizeof(struct sockaddr_in);
531 sp.sin_family = sm.sin_family = dp.sin_family =
532 dm.sin_family = AF_INET;
533 sp.sin_addr = sc->g_src;
534 dp.sin_addr = sc->g_dst;
535 sm.sin_addr.s_addr = dm.sin_addr.s_addr =
538 sc->encap = encap_attach(AF_INET, sc->g_proto,
539 sintosa(&sp), sintosa(&sm), sintosa(&dp),
540 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ?
541 &in_gre_protosw : &in_mobile_protosw, sc);
542 if (sc->encap == NULL)
543 kprintf("%s: unable to attach encap\n",
544 if_name(&sc->sc_if));
546 if (sc->route.ro_rt != 0) /* free old route */
547 RTFREE(sc->route.ro_rt);
548 if (gre_compute_route(sc) == 0)
549 ifp->if_flags |= IFF_RUNNING;
551 ifp->if_flags &= ~IFF_RUNNING;
555 memset(&si, 0, sizeof(si));
556 si.sin_family = AF_INET;
557 si.sin_len = sizeof(struct sockaddr_in);
558 si.sin_addr.s_addr = sc->g_src.s_addr;
563 memset(&si, 0, sizeof(si));
564 si.sin_family = AF_INET;
565 si.sin_len = sizeof(struct sockaddr_in);
566 si.sin_addr.s_addr = sc->g_dst.s_addr;
571 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
573 if (aifr->ifra_addr.sin_family != AF_INET ||
574 aifr->ifra_dstaddr.sin_family != AF_INET) {
575 error = EAFNOSUPPORT;
578 if (aifr->ifra_addr.sin_len != sizeof(si) ||
579 aifr->ifra_dstaddr.sin_len != sizeof(si)) {
583 sc->g_src = aifr->ifra_addr.sin_addr;
584 sc->g_dst = aifr->ifra_dstaddr.sin_addr;
586 case SIOCSLIFPHYADDR:
587 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
589 if (lifr->addr.ss_family != AF_INET ||
590 lifr->dstaddr.ss_family != AF_INET) {
591 error = EAFNOSUPPORT;
594 if (lifr->addr.ss_len != sizeof(si) ||
595 lifr->dstaddr.ss_len != sizeof(si)) {
599 sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr;
601 (satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr;
604 if ((error = priv_check_cred(cr, PRIV_ROOT, NULL_CRED_OKAY)) != 0)
606 sc->g_src.s_addr = INADDR_ANY;
607 sc->g_dst.s_addr = INADDR_ANY;
609 case SIOCGLIFPHYADDR:
610 if (sc->g_src.s_addr == INADDR_ANY ||
611 sc->g_dst.s_addr == INADDR_ANY) {
612 error = EADDRNOTAVAIL;
615 memset(&si, 0, sizeof(si));
616 si.sin_family = AF_INET;
617 si.sin_len = sizeof(struct sockaddr_in);
618 si.sin_addr.s_addr = sc->g_src.s_addr;
619 memcpy(&lifr->addr, &si, sizeof(si));
620 si.sin_addr.s_addr = sc->g_dst.s_addr;
621 memcpy(&lifr->dstaddr, &si, sizeof(si));
623 case SIOCGIFPSRCADDR:
624 if (sc->g_src.s_addr == INADDR_ANY) {
625 error = EADDRNOTAVAIL;
628 memset(&si, 0, sizeof(si));
629 si.sin_family = AF_INET;
630 si.sin_len = sizeof(struct sockaddr_in);
631 si.sin_addr.s_addr = sc->g_src.s_addr;
632 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
634 case SIOCGIFPDSTADDR:
635 if (sc->g_dst.s_addr == INADDR_ANY) {
636 error = EADDRNOTAVAIL;
639 memset(&si, 0, sizeof(si));
640 si.sin_family = AF_INET;
641 si.sin_len = sizeof(struct sockaddr_in);
642 si.sin_addr.s_addr = sc->g_dst.s_addr;
643 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
655 * computes a route to our destination that is not the one
656 * which would be taken by ip_output(), as this one will loop back to
657 * us. If the interface is p2p as a--->b, then a routing entry exists
658 * If we now send a packet to b (e.g. ping b), this will come down here
659 * gets src=a, dst=b tacked on and would from ip_ouput() sent back to
661 * Goal here is to compute a route to b that is less specific than
662 * a-->b. We know that this one exists as in normal operation we have
663 * at least a default route which matches.
666 gre_compute_route(struct gre_softc *sc)
673 memset(ro, 0, sizeof(struct route));
674 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
675 ro->ro_dst.sa_family = AF_INET;
676 ro->ro_dst.sa_len = sizeof(ro->ro_dst);
679 * toggle last bit, so our interface is not found, but a less
680 * specific route. I'd rather like to specify a shorter mask,
681 * but this is not possible. Should work though. XXX
682 * there is a simpler way ...
684 if ((sc->sc_if.if_flags & IFF_LINK1) == 0) {
685 a = ntohl(sc->g_dst.s_addr);
690 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr
695 kprintf("%s: searching a route to %s", if_name(&sc->sc_if),
696 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr));
702 * check if this returned a route at all and this route is no
703 * recursion to ourself
705 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) {
707 if (ro->ro_rt == NULL)
708 kprintf(" - no route found!\n");
710 kprintf(" - route loops back to ourself!\n");
712 return EADDRNOTAVAIL;
716 * now change it back - else ip_output will just drop
717 * the route and search one to this interface ...
719 if ((sc->sc_if.if_flags & IFF_LINK1) == 0)
720 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
723 kprintf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp),
724 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr));
732 * do a checksum of a buffer - much like in_cksum, which operates on
736 gre_in_cksum(u_short *p, u_int len)
739 int nwords = len >> 1;
741 while (nwords-- != 0)
749 u.c[0] = *(u_char *)p;
754 /* end-around-carry */
755 sum = (sum >> 16) + (sum & 0xffff);
761 gremodevent(module_t mod, int type, void *data)
769 if_clone_detach(&gre_cloner);
771 while (!LIST_EMPTY(&gre_softc_list))
772 gre_clone_destroy(&LIST_FIRST(&gre_softc_list)->sc_if);
779 static moduledata_t gre_mod = {
785 DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
786 MODULE_VERSION(if_gre, 1);