1/* $NetBSD: if_gre.c,v 1.49 2003/12/11 00:22:29 itojun Exp $ */
2/* $FreeBSD: head/sys/net/if_gre.c 148887 2005-08-09 10:20:02Z rwatson $ */
3
4/*-
5 * Copyright (c) 1998 The NetBSD Foundation, Inc.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Heiko W.Rupp <hwr@pilhuhn.de>
10 *
11 * IPv6-over-GRE contributed by Gert Doering <gert@greenie.muc.de>
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. All advertising materials mentioning features or use of this software
22 * must display the following acknowledgement:
23 * This product includes software developed by the NetBSD
24 * Foundation, Inc. and its contributors.
25 * 4. Neither the name of The NetBSD Foundation nor the names of its
26 * contributors may be used to endorse or promote products derived
27 * from this software without specific prior written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
30 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
31 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
32 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
33 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
34 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
35 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
36 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
37 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
39 * POSSIBILITY OF SUCH DAMAGE.
40 */
41
42/*
43 * Encapsulate L3 protocols into IP
44 * See RFC 2784 (successor of RFC 1701 and 1702) for more details.
45 * If_gre is compatible with Cisco GRE tunnels, so you can
46 * have a NetBSD box as the other end of a tunnel interface of a Cisco
47 * router. See gre(4) for more details.
48 * Also supported: IP in IP encaps (proto 55) as of RFC 2004
49 */
50
51#include "opt_atalk.h"
52#include "opt_inet.h"
53#include "opt_inet6.h"
54
55#include <sys/param.h>
56#include <sys/kernel.h>
57#include <sys/malloc.h>
58#include <sys/module.h>
59#include <sys/mbuf.h>
60#include <sys/protosw.h>
61#include <sys/socket.h>
62#include <sys/sockio.h>
63#include <sys/sysctl.h>
64#include <sys/systm.h>
65
66#include <net/ethernet.h>
67#include <net/if.h>
68#include <net/if_clone.h>
69#include <net/if_types.h>
70#include <net/route.h>
71
72#ifdef INET
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>
80#else
81#error "Huh? if_gre without inet?"
82#endif
83
84#include <net/bpf.h>
85
86#include <net/net_osdep.h>
87#include <net/if_gre.h>
88
89/*
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
92 * other vendors use.
93 */
94#define GREMTU 1476
95
96#define GRENAME "gre"
97
98/*
99 * gre_mtx protects all global variables in if_gre.c.
100 * XXX: gre_softc data not protected yet.
101 */
102struct mtx gre_mtx;
103static MALLOC_DEFINE(M_GRE, GRENAME, "Generic Routing Encapsulation");
104
105struct gre_softc_head gre_softc_list;
106
107static int gre_clone_create(struct if_clone *, int);
108static void gre_clone_destroy(struct ifnet *);
109static int gre_ioctl(struct ifnet *, u_long, caddr_t);
110static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *,
111 struct rtentry *rt);
112
113IFC_SIMPLE_DECLARE(gre, 0);
114
115static int gre_compute_route(struct gre_softc *sc);
116
117static void greattach(void);
118
119#ifdef INET
120extern struct domain inetdomain;
121static const struct protosw in_gre_protosw =
122{ SOCK_RAW, &inetdomain, IPPROTO_GRE, PR_ATOMIC|PR_ADDR,
123 (pr_input_t*)gre_input, (pr_output_t*)rip_output, rip_ctlinput, rip_ctloutput,
124 0,
125 0, 0, 0, 0,
126 &rip_usrreqs
127};
128static const struct protosw in_mobile_protosw =
129{ SOCK_RAW, &inetdomain, IPPROTO_MOBILE, PR_ATOMIC|PR_ADDR,
130 (pr_input_t*)gre_mobile_input, (pr_output_t*)rip_output, rip_ctlinput, rip_ctloutput,
131 0,
132 0, 0, 0, 0,
133 &rip_usrreqs
134};
135#endif
136
137SYSCTL_DECL(_net_link);
138SYSCTL_NODE(_net_link, IFT_TUNNEL, gre, CTLFLAG_RW, 0,
139 "Generic Routing Encapsulation");
140#ifndef MAX_GRE_NEST
141/*
142 * This macro controls the default upper limitation on nesting of gre tunnels.
143 * Since, setting a large value to this macro with a careless configuration
144 * may introduce system crash, we don't allow any nestings by default.
145 * If you need to configure nested gre tunnels, you can define this macro
146 * in your kernel configuration file. However, if you do so, please be
147 * careful to configure the tunnels so that it won't make a loop.
148 */
149#define MAX_GRE_NEST 1
150#endif
151static int max_gre_nesting = MAX_GRE_NEST;
152SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW,
153 &max_gre_nesting, 0, "Max nested tunnels");
154
155/* ARGSUSED */
156static void
157greattach(void)
158{
159
160 mtx_init(&gre_mtx, "gre_mtx", NULL, MTX_DEF);
161 LIST_INIT(&gre_softc_list);
162 if_clone_attach(&gre_cloner);
163}
164
165static int
166gre_clone_create(ifc, unit)
167 struct if_clone *ifc;
168 int unit;
169{
170 struct gre_softc *sc;
171
172 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK | M_ZERO);
173
174 GRE2IFP(sc) = if_alloc(IFT_TUNNEL);
175 if (GRE2IFP(sc) == NULL) {
176 free(sc, M_GRE);
177 return (ENOSPC);
178 }
179
180 GRE2IFP(sc)->if_softc = sc;
181 if_initname(GRE2IFP(sc), ifc->ifc_name, unit);
182
183 GRE2IFP(sc)->if_snd.ifq_maxlen = IFQ_MAXLEN;
184 GRE2IFP(sc)->if_addrlen = 0;
185 GRE2IFP(sc)->if_hdrlen = 24; /* IP + GRE */
186 GRE2IFP(sc)->if_mtu = GREMTU;
187 GRE2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
188 GRE2IFP(sc)->if_output = gre_output;
189 GRE2IFP(sc)->if_ioctl = gre_ioctl;
190 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY;
191 sc->g_proto = IPPROTO_GRE;
192 GRE2IFP(sc)->if_flags |= IFF_LINK0;
193 sc->encap = NULL;
194 sc->called = 0;
195 sc->wccp_ver = WCCP_V1;
196 if_attach(GRE2IFP(sc));
197 bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t));
198 mtx_lock(&gre_mtx);
199 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list);
200 mtx_unlock(&gre_mtx);
201 return (0);
202}
203
204static void
205gre_destroy(struct gre_softc *sc)
206{
207
208#ifdef INET
209 if (sc->encap != NULL)
210 encap_detach(sc->encap);
211#endif
212 bpfdetach(GRE2IFP(sc));
213 if_detach(GRE2IFP(sc));
214 if_free(GRE2IFP(sc));
215 free(sc, M_GRE);
216}
217
218static void
219gre_clone_destroy(ifp)
220 struct ifnet *ifp;
221{
222 struct gre_softc *sc = ifp->if_softc;
223
224 mtx_lock(&gre_mtx);
225 LIST_REMOVE(sc, sc_list);
226 mtx_unlock(&gre_mtx);
227 gre_destroy(sc);
228}
229
230/*
231 * The output routine. Takes a packet and encapsulates it in the protocol
232 * given by sc->g_proto. See also RFC 1701 and RFC 2004
233 */
234static int
235gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
236 struct rtentry *rt)
237{
238 int error = 0;
239 struct gre_softc *sc = ifp->if_softc;
240 struct greip *gh;
241 struct ip *ip;
242 u_short ip_id = 0;
243 uint8_t ip_tos = 0;
244 u_int16_t etype = 0;
245 struct mobile_h mob_h;
246 u_int32_t af;
247
248 /*
249 * gre may cause infinite recursion calls when misconfigured.
250 * We'll prevent this by introducing upper limit.
251 */
252 if (++(sc->called) > max_gre_nesting) {
253 printf("%s: gre_output: recursively called too many "
254 "times(%d)\n", if_name(GRE2IFP(sc)), sc->called);
255 m_freem(m);
256 error = EIO; /* is there better errno? */
257 goto end;
258 }
259
260 if (!((ifp->if_flags & IFF_UP) &&
261 (ifp->if_drv_flags & IFF_DRV_RUNNING)) ||
262 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) {
263 m_freem(m);
264 error = ENETDOWN;
265 goto end;
266 }
267
268 gh = NULL;
269 ip = NULL;
270
271 /* BPF writes need to be handled specially. */
272 if (dst->sa_family == AF_UNSPEC) {
273 bcopy(dst->sa_data, &af, sizeof(af));
274 dst->sa_family = af;
275 }
276
277 if (ifp->if_bpf) {
278 af = dst->sa_family;
279 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
280 }
281
282 m->m_flags &= ~(M_BCAST|M_MCAST);
283
284 if (sc->g_proto == IPPROTO_MOBILE) {
285 if (dst->sa_family == AF_INET) {
286 struct mbuf *m0;
287 int msiz;
288
289 ip = mtod(m, struct ip *);
290
291 /*
292 * RFC2004 specifies that fragmented diagrams shouldn't
293 * be encapsulated.
294 */
295 if ((ip->ip_off & IP_MF) != 0) {
296 _IF_DROP(&ifp->if_snd);
297 m_freem(m);
298 error = EINVAL; /* is there better errno? */
299 goto end;
300 }
301 memset(&mob_h, 0, MOB_H_SIZ_L);
302 mob_h.proto = (ip->ip_p) << 8;
303 mob_h.odst = ip->ip_dst.s_addr;
304 ip->ip_dst.s_addr = sc->g_dst.s_addr;
305
306 /*
307 * If the packet comes from our host, we only change
308 * the destination address in the IP header.
309 * Else we also need to save and change the source
310 */
311 if (in_hosteq(ip->ip_src, sc->g_src)) {
312 msiz = MOB_H_SIZ_S;
313 } else {
314 mob_h.proto |= MOB_H_SBIT;
315 mob_h.osrc = ip->ip_src.s_addr;
316 ip->ip_src.s_addr = sc->g_src.s_addr;
317 msiz = MOB_H_SIZ_L;
318 }
319 mob_h.proto = htons(mob_h.proto);
320 mob_h.hcrc = gre_in_cksum((u_int16_t *)&mob_h, msiz);
321
322 if ((m->m_data - msiz) < m->m_pktdat) {
323 /* need new mbuf */
324 MGETHDR(m0, M_DONTWAIT, MT_HEADER);
325 if (m0 == NULL) {
326 _IF_DROP(&ifp->if_snd);
327 m_freem(m);
328 error = ENOBUFS;
329 goto end;
330 }
331 m0->m_next = m;
332 m->m_data += sizeof(struct ip);
333 m->m_len -= sizeof(struct ip);
334 m0->m_pkthdr.len = m->m_pkthdr.len + msiz;
335 m0->m_len = msiz + sizeof(struct ip);
336 m0->m_data += max_linkhdr;
337 memcpy(mtod(m0, caddr_t), (caddr_t)ip,
338 sizeof(struct ip));
339 m = m0;
340 } else { /* we have some space left in the old one */
341 m->m_data -= msiz;
342 m->m_len += msiz;
343 m->m_pkthdr.len += msiz;
344 bcopy(ip, mtod(m, caddr_t),
345 sizeof(struct ip));
346 }
347 ip = mtod(m, struct ip *);
348 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz);
349 ip->ip_len = ntohs(ip->ip_len) + msiz;
350 } else { /* AF_INET */
351 _IF_DROP(&ifp->if_snd);
352 m_freem(m);
353 error = EINVAL;
354 goto end;
355 }
356 } else if (sc->g_proto == IPPROTO_GRE) {
357 switch (dst->sa_family) {
358 case AF_INET:
359 ip = mtod(m, struct ip *);
360 ip_tos = ip->ip_tos;
361 ip_id = ip->ip_id;
362 etype = ETHERTYPE_IP;
363 break;
364#ifdef INET6
365 case AF_INET6:
366 ip_id = ip_newid();
367 etype = ETHERTYPE_IPV6;
368 break;
369#endif
370#ifdef NETATALK
371 case AF_APPLETALK:
372 etype = ETHERTYPE_ATALK;
373 break;
374#endif
375 default:
376 _IF_DROP(&ifp->if_snd);
377 m_freem(m);
378 error = EAFNOSUPPORT;
379 goto end;
380 }
381 M_PREPEND(m, sizeof(struct greip), M_DONTWAIT);
382 } else {
383 _IF_DROP(&ifp->if_snd);
384 m_freem(m);
385 error = EINVAL;
386 goto end;
387 }
388
389 if (m == NULL) { /* mbuf allocation failed */
390 _IF_DROP(&ifp->if_snd);
391 error = ENOBUFS;
392 goto end;
393 }
394
395 gh = mtod(m, struct greip *);
396 if (sc->g_proto == IPPROTO_GRE) {
397 /* we don't have any GRE flags for now */
398 memset((void *)gh, 0, sizeof(struct greip));
399 gh->gi_ptype = htons(etype);
400 }
401
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_v = IPPROTO_IPV4;
407 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2;
408 ((struct ip*)gh)->ip_ttl = GRE_TTL;
409 ((struct ip*)gh)->ip_tos = ip_tos;
410 ((struct ip*)gh)->ip_id = ip_id;
411 gh->gi_len = m->m_pkthdr.len;
412 }
413
414 ifp->if_opackets++;
415 ifp->if_obytes += m->m_pkthdr.len;
416 /*
417 * Send it off and with IP_FORWARD flag to prevent it from
418 * overwriting the ip_id again. ip_id is already set to the
419 * ip_id of the encapsulated packet.
420 */
421 error = ip_output(m, NULL, &sc->route, IP_FORWARDING,
422 (struct ip_moptions *)NULL, (struct inpcb *)NULL);
423 end:
424 sc->called = 0;
425 if (error)
426 ifp->if_oerrors++;
427 return (error);
428}
429
430static int
431gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
432{
433 struct ifreq *ifr = (struct ifreq *)data;
434 struct if_laddrreq *lifr = (struct if_laddrreq *)data;
435 struct in_aliasreq *aifr = (struct in_aliasreq *)data;
436 struct gre_softc *sc = ifp->if_softc;
437 int s;
438 struct sockaddr_in si;
439 struct sockaddr *sa = NULL;
440 int error;
441 struct sockaddr_in sp, sm, dp, dm;
442
443 error = 0;
444
445 s = splnet();
446 switch (cmd) {
447 case SIOCSIFADDR:
448 ifp->if_flags |= IFF_UP;
449 break;
450 case SIOCSIFDSTADDR:
451 break;
452 case SIOCSIFFLAGS:
453 if ((error = suser(curthread)) != 0)
454 break;
455 if ((ifr->ifr_flags & IFF_LINK0) != 0)
456 sc->g_proto = IPPROTO_GRE;
457 else
458 sc->g_proto = IPPROTO_MOBILE;
459 if ((ifr->ifr_flags & IFF_LINK2) != 0)
460 sc->wccp_ver = WCCP_V2;
461 else
462 sc->wccp_ver = WCCP_V1;
463 goto recompute;
464 case SIOCSIFMTU:
465 if ((error = suser(curthread)) != 0)
466 break;
467 if (ifr->ifr_mtu < 576) {
468 error = EINVAL;
469 break;
470 }
471 ifp->if_mtu = ifr->ifr_mtu;
472 break;
473 case SIOCGIFMTU:
474 ifr->ifr_mtu = GRE2IFP(sc)->if_mtu;
475 break;
476 case SIOCADDMULTI:
477 case SIOCDELMULTI:
478 if ((error = suser(curthread)) != 0)
479 break;
480 if (ifr == 0) {
481 error = EAFNOSUPPORT;
482 break;
483 }
484 switch (ifr->ifr_addr.sa_family) {
485#ifdef INET
486 case AF_INET:
487 break;
488#endif
489#ifdef INET6
490 case AF_INET6:
491 break;
492#endif
493 default:
494 error = EAFNOSUPPORT;
495 break;
496 }
497 break;
498 case GRESPROTO:
499 if ((error = suser(curthread)) != 0)
500 break;
501 sc->g_proto = ifr->ifr_flags;
502 switch (sc->g_proto) {
503 case IPPROTO_GRE:
504 ifp->if_flags |= IFF_LINK0;
505 break;
506 case IPPROTO_MOBILE:
507 ifp->if_flags &= ~IFF_LINK0;
508 break;
509 default:
510 error = EPROTONOSUPPORT;
511 break;
512 }
513 goto recompute;
514 case GREGPROTO:
515 ifr->ifr_flags = sc->g_proto;
516 break;
517 case GRESADDRS:
518 case GRESADDRD:
519 if ((error = suser(curthread)) != 0)
520 break;
521 /*
522 * set tunnel endpoints, compute a less specific route
523 * to the remote end and mark if as up
524 */
525 sa = &ifr->ifr_addr;
526 if (cmd == GRESADDRS)
527 sc->g_src = (satosin(sa))->sin_addr;
528 if (cmd == GRESADDRD)
529 sc->g_dst = (satosin(sa))->sin_addr;
530 recompute:
531#ifdef INET
532 if (sc->encap != NULL) {
533 encap_detach(sc->encap);
534 sc->encap = NULL;
535 }
536#endif
537 if ((sc->g_src.s_addr != INADDR_ANY) &&
538 (sc->g_dst.s_addr != INADDR_ANY)) {
539 bzero(&sp, sizeof(sp));
540 bzero(&sm, sizeof(sm));
541 bzero(&dp, sizeof(dp));
542 bzero(&dm, sizeof(dm));
543 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len =
544 sizeof(struct sockaddr_in);
545 sp.sin_family = sm.sin_family = dp.sin_family =
546 dm.sin_family = AF_INET;
547 sp.sin_addr = sc->g_src;
548 dp.sin_addr = sc->g_dst;
549 sm.sin_addr.s_addr = dm.sin_addr.s_addr =
550 INADDR_BROADCAST;
551#ifdef INET
552 sc->encap = encap_attach(AF_INET, sc->g_proto,
553 sintosa(&sp), sintosa(&sm), sintosa(&dp),
554 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ?
555 &in_gre_protosw : &in_mobile_protosw, sc);
556 if (sc->encap == NULL)
557 printf("%s: unable to attach encap\n",
558 if_name(GRE2IFP(sc)));
559#endif
560 if (sc->route.ro_rt != 0) /* free old route */
561 RTFREE(sc->route.ro_rt);
562 if (gre_compute_route(sc) == 0)
563 ifp->if_drv_flags |= IFF_DRV_RUNNING;
564 else
565 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
566 }
567 break;
568 case GREGADDRS:
569 memset(&si, 0, sizeof(si));
570 si.sin_family = AF_INET;
571 si.sin_len = sizeof(struct sockaddr_in);
572 si.sin_addr.s_addr = sc->g_src.s_addr;
573 sa = sintosa(&si);
574 ifr->ifr_addr = *sa;
575 break;
576 case GREGADDRD:
577 memset(&si, 0, sizeof(si));
578 si.sin_family = AF_INET;
579 si.sin_len = sizeof(struct sockaddr_in);
580 si.sin_addr.s_addr = sc->g_dst.s_addr;
581 sa = sintosa(&si);
582 ifr->ifr_addr = *sa;
583 break;
584 case SIOCSIFPHYADDR:
585 if ((error = suser(curthread)) != 0)
586 break;
587 if (aifr->ifra_addr.sin_family != AF_INET ||
588 aifr->ifra_dstaddr.sin_family != AF_INET) {
589 error = EAFNOSUPPORT;
590 break;
591 }
592 if (aifr->ifra_addr.sin_len != sizeof(si) ||
593 aifr->ifra_dstaddr.sin_len != sizeof(si)) {
594 error = EINVAL;
595 break;
596 }
597 sc->g_src = aifr->ifra_addr.sin_addr;
598 sc->g_dst = aifr->ifra_dstaddr.sin_addr;
599 goto recompute;
600 case SIOCSLIFPHYADDR:
601 if ((error = suser(curthread)) != 0)
602 break;
603 if (lifr->addr.ss_family != AF_INET ||
604 lifr->dstaddr.ss_family != AF_INET) {
605 error = EAFNOSUPPORT;
606 break;
607 }
608 if (lifr->addr.ss_len != sizeof(si) ||
609 lifr->dstaddr.ss_len != sizeof(si)) {
610 error = EINVAL;
611 break;
612 }
613 sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr;
614 sc->g_dst =
615 (satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr;
616 goto recompute;
617 case SIOCDIFPHYADDR:
618 if ((error = suser(curthread)) != 0)
619 break;
620 sc->g_src.s_addr = INADDR_ANY;
621 sc->g_dst.s_addr = INADDR_ANY;
622 goto recompute;
623 case SIOCGLIFPHYADDR:
624 if (sc->g_src.s_addr == INADDR_ANY ||
625 sc->g_dst.s_addr == INADDR_ANY) {
626 error = EADDRNOTAVAIL;
627 break;
628 }
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 memcpy(&lifr->addr, &si, sizeof(si));
634 si.sin_addr.s_addr = sc->g_dst.s_addr;
635 memcpy(&lifr->dstaddr, &si, sizeof(si));
636 break;
637 case SIOCGIFPSRCADDR:
638#ifdef INET6
639 case SIOCGIFPSRCADDR_IN6:
640#endif
641 if (sc->g_src.s_addr == INADDR_ANY) {
642 error = EADDRNOTAVAIL;
643 break;
644 }
645 memset(&si, 0, sizeof(si));
646 si.sin_family = AF_INET;
647 si.sin_len = sizeof(struct sockaddr_in);
648 si.sin_addr.s_addr = sc->g_src.s_addr;
649 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
650 break;
651 case SIOCGIFPDSTADDR:
652#ifdef INET6
653 case SIOCGIFPDSTADDR_IN6:
654#endif
655 if (sc->g_dst.s_addr == INADDR_ANY) {
656 error = EADDRNOTAVAIL;
657 break;
658 }
659 memset(&si, 0, sizeof(si));
660 si.sin_family = AF_INET;
661 si.sin_len = sizeof(struct sockaddr_in);
662 si.sin_addr.s_addr = sc->g_dst.s_addr;
663 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
664 break;
665 default:
666 error = EINVAL;
667 break;
668 }
669
670 splx(s);
671 return (error);
672}
673
674/*
675 * computes a route to our destination that is not the one
676 * which would be taken by ip_output(), as this one will loop back to
677 * us. If the interface is p2p as a--->b, then a routing entry exists
678 * If we now send a packet to b (e.g. ping b), this will come down here
679 * gets src=a, dst=b tacked on and would from ip_output() sent back to
680 * if_gre.
681 * Goal here is to compute a route to b that is less specific than
682 * a-->b. We know that this one exists as in normal operation we have
683 * at least a default route which matches.
684 */
685static int
686gre_compute_route(struct gre_softc *sc)
687{
688 struct route *ro;
689 u_int32_t a, b, c;
690
691 ro = &sc->route;
692
693 memset(ro, 0, sizeof(struct route));
694 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
695 ro->ro_dst.sa_family = AF_INET;
696 ro->ro_dst.sa_len = sizeof(ro->ro_dst);
697
698 /*
699 * toggle last bit, so our interface is not found, but a less
700 * specific route. I'd rather like to specify a shorter mask,
701 * but this is not possible. Should work though. XXX
702 * there is a simpler way ...
703 */
704 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) {
705 a = ntohl(sc->g_dst.s_addr);
706 b = a & 0x01;
707 c = a & 0xfffffffe;
708 b = b ^ 0x01;
709 a = b | c;
710 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr
711 = htonl(a);
712 }
713
714#ifdef DIAGNOSTIC
715 printf("%s: searching for a route to %s", if_name(GRE2IFP(sc)),
716 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr));
717#endif
718
719 rtalloc(ro);
720
721 /*
722 * check if this returned a route at all and this route is no
723 * recursion to ourself
724 */
725 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) {
726#ifdef DIAGNOSTIC
727 if (ro->ro_rt == NULL)
728 printf(" - no route found!\n");
729 else
730 printf(" - route loops back to ourself!\n");
731#endif
732 return EADDRNOTAVAIL;
733 }
734
735 /*
736 * now change it back - else ip_output will just drop
737 * the route and search one to this interface ...
738 */
739 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0)
740 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
741
742#ifdef DIAGNOSTIC
743 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp),
744 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr));
745 printf("\n");
746#endif
747
748 return 0;
749}
750
751/*
752 * do a checksum of a buffer - much like in_cksum, which operates on
753 * mbufs.
754 */
755u_int16_t
756gre_in_cksum(u_int16_t *p, u_int len)
757{
758 u_int32_t sum = 0;
759 int nwords = len >> 1;
760
761 while (nwords-- != 0)
762 sum += *p++;
763
764 if (len & 1) {
765 union {
766 u_short w;
767 u_char c[2];
768 } u;
769 u.c[0] = *(u_char *)p;
770 u.c[1] = 0;
771 sum += u.w;
772 }
773
774 /* end-around-carry */
775 sum = (sum >> 16) + (sum & 0xffff);
776 sum += (sum >> 16);
777 return (~sum);
778}
779
780static int
781gremodevent(module_t mod, int type, void *data)
782{
783 struct gre_softc *sc;
784
785 switch (type) {
786 case MOD_LOAD:
787 greattach();
788 break;
789 case MOD_UNLOAD:
790 if_clone_detach(&gre_cloner);
791
792 mtx_lock(&gre_mtx);
793 while ((sc = LIST_FIRST(&gre_softc_list)) != NULL) {
794 LIST_REMOVE(sc, sc_list);
795 mtx_unlock(&gre_mtx);
796 gre_destroy(sc);
797 mtx_lock(&gre_mtx);
798 }
799 mtx_unlock(&gre_mtx);
800 mtx_destroy(&gre_mtx);
801 break;
802 default:
803 return EOPNOTSUPP;
804 }
805 return 0;
806}
807
808static moduledata_t gre_mod = {
809 "if_gre",
810 gremodevent,
811 0
812};
813
814DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
815MODULE_VERSION(if_gre, 1);
2/* $FreeBSD: head/sys/net/if_gre.c 148887 2005-08-09 10:20:02Z rwatson $ */
3
4/*-
5 * Copyright (c) 1998 The NetBSD Foundation, Inc.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Heiko W.Rupp <hwr@pilhuhn.de>
10 *
11 * IPv6-over-GRE contributed by Gert Doering <gert@greenie.muc.de>
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. All advertising materials mentioning features or use of this software
22 * must display the following acknowledgement:
23 * This product includes software developed by the NetBSD
24 * Foundation, Inc. and its contributors.
25 * 4. Neither the name of The NetBSD Foundation nor the names of its
26 * contributors may be used to endorse or promote products derived
27 * from this software without specific prior written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
30 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
31 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
32 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
33 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
34 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
35 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
36 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
37 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
39 * POSSIBILITY OF SUCH DAMAGE.
40 */
41
42/*
43 * Encapsulate L3 protocols into IP
44 * See RFC 2784 (successor of RFC 1701 and 1702) for more details.
45 * If_gre is compatible with Cisco GRE tunnels, so you can
46 * have a NetBSD box as the other end of a tunnel interface of a Cisco
47 * router. See gre(4) for more details.
48 * Also supported: IP in IP encaps (proto 55) as of RFC 2004
49 */
50
51#include "opt_atalk.h"
52#include "opt_inet.h"
53#include "opt_inet6.h"
54
55#include <sys/param.h>
56#include <sys/kernel.h>
57#include <sys/malloc.h>
58#include <sys/module.h>
59#include <sys/mbuf.h>
60#include <sys/protosw.h>
61#include <sys/socket.h>
62#include <sys/sockio.h>
63#include <sys/sysctl.h>
64#include <sys/systm.h>
65
66#include <net/ethernet.h>
67#include <net/if.h>
68#include <net/if_clone.h>
69#include <net/if_types.h>
70#include <net/route.h>
71
72#ifdef INET
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>
80#else
81#error "Huh? if_gre without inet?"
82#endif
83
84#include <net/bpf.h>
85
86#include <net/net_osdep.h>
87#include <net/if_gre.h>
88
89/*
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
92 * other vendors use.
93 */
94#define GREMTU 1476
95
96#define GRENAME "gre"
97
98/*
99 * gre_mtx protects all global variables in if_gre.c.
100 * XXX: gre_softc data not protected yet.
101 */
102struct mtx gre_mtx;
103static MALLOC_DEFINE(M_GRE, GRENAME, "Generic Routing Encapsulation");
104
105struct gre_softc_head gre_softc_list;
106
107static int gre_clone_create(struct if_clone *, int);
108static void gre_clone_destroy(struct ifnet *);
109static int gre_ioctl(struct ifnet *, u_long, caddr_t);
110static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *,
111 struct rtentry *rt);
112
113IFC_SIMPLE_DECLARE(gre, 0);
114
115static int gre_compute_route(struct gre_softc *sc);
116
117static void greattach(void);
118
119#ifdef INET
120extern struct domain inetdomain;
121static const struct protosw in_gre_protosw =
122{ SOCK_RAW, &inetdomain, IPPROTO_GRE, PR_ATOMIC|PR_ADDR,
123 (pr_input_t*)gre_input, (pr_output_t*)rip_output, rip_ctlinput, rip_ctloutput,
124 0,
125 0, 0, 0, 0,
126 &rip_usrreqs
127};
128static const struct protosw in_mobile_protosw =
129{ SOCK_RAW, &inetdomain, IPPROTO_MOBILE, PR_ATOMIC|PR_ADDR,
130 (pr_input_t*)gre_mobile_input, (pr_output_t*)rip_output, rip_ctlinput, rip_ctloutput,
131 0,
132 0, 0, 0, 0,
133 &rip_usrreqs
134};
135#endif
136
137SYSCTL_DECL(_net_link);
138SYSCTL_NODE(_net_link, IFT_TUNNEL, gre, CTLFLAG_RW, 0,
139 "Generic Routing Encapsulation");
140#ifndef MAX_GRE_NEST
141/*
142 * This macro controls the default upper limitation on nesting of gre tunnels.
143 * Since, setting a large value to this macro with a careless configuration
144 * may introduce system crash, we don't allow any nestings by default.
145 * If you need to configure nested gre tunnels, you can define this macro
146 * in your kernel configuration file. However, if you do so, please be
147 * careful to configure the tunnels so that it won't make a loop.
148 */
149#define MAX_GRE_NEST 1
150#endif
151static int max_gre_nesting = MAX_GRE_NEST;
152SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW,
153 &max_gre_nesting, 0, "Max nested tunnels");
154
155/* ARGSUSED */
156static void
157greattach(void)
158{
159
160 mtx_init(&gre_mtx, "gre_mtx", NULL, MTX_DEF);
161 LIST_INIT(&gre_softc_list);
162 if_clone_attach(&gre_cloner);
163}
164
165static int
166gre_clone_create(ifc, unit)
167 struct if_clone *ifc;
168 int unit;
169{
170 struct gre_softc *sc;
171
172 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK | M_ZERO);
173
174 GRE2IFP(sc) = if_alloc(IFT_TUNNEL);
175 if (GRE2IFP(sc) == NULL) {
176 free(sc, M_GRE);
177 return (ENOSPC);
178 }
179
180 GRE2IFP(sc)->if_softc = sc;
181 if_initname(GRE2IFP(sc), ifc->ifc_name, unit);
182
183 GRE2IFP(sc)->if_snd.ifq_maxlen = IFQ_MAXLEN;
184 GRE2IFP(sc)->if_addrlen = 0;
185 GRE2IFP(sc)->if_hdrlen = 24; /* IP + GRE */
186 GRE2IFP(sc)->if_mtu = GREMTU;
187 GRE2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
188 GRE2IFP(sc)->if_output = gre_output;
189 GRE2IFP(sc)->if_ioctl = gre_ioctl;
190 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY;
191 sc->g_proto = IPPROTO_GRE;
192 GRE2IFP(sc)->if_flags |= IFF_LINK0;
193 sc->encap = NULL;
194 sc->called = 0;
195 sc->wccp_ver = WCCP_V1;
196 if_attach(GRE2IFP(sc));
197 bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t));
198 mtx_lock(&gre_mtx);
199 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list);
200 mtx_unlock(&gre_mtx);
201 return (0);
202}
203
204static void
205gre_destroy(struct gre_softc *sc)
206{
207
208#ifdef INET
209 if (sc->encap != NULL)
210 encap_detach(sc->encap);
211#endif
212 bpfdetach(GRE2IFP(sc));
213 if_detach(GRE2IFP(sc));
214 if_free(GRE2IFP(sc));
215 free(sc, M_GRE);
216}
217
218static void
219gre_clone_destroy(ifp)
220 struct ifnet *ifp;
221{
222 struct gre_softc *sc = ifp->if_softc;
223
224 mtx_lock(&gre_mtx);
225 LIST_REMOVE(sc, sc_list);
226 mtx_unlock(&gre_mtx);
227 gre_destroy(sc);
228}
229
230/*
231 * The output routine. Takes a packet and encapsulates it in the protocol
232 * given by sc->g_proto. See also RFC 1701 and RFC 2004
233 */
234static int
235gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
236 struct rtentry *rt)
237{
238 int error = 0;
239 struct gre_softc *sc = ifp->if_softc;
240 struct greip *gh;
241 struct ip *ip;
242 u_short ip_id = 0;
243 uint8_t ip_tos = 0;
244 u_int16_t etype = 0;
245 struct mobile_h mob_h;
246 u_int32_t af;
247
248 /*
249 * gre may cause infinite recursion calls when misconfigured.
250 * We'll prevent this by introducing upper limit.
251 */
252 if (++(sc->called) > max_gre_nesting) {
253 printf("%s: gre_output: recursively called too many "
254 "times(%d)\n", if_name(GRE2IFP(sc)), sc->called);
255 m_freem(m);
256 error = EIO; /* is there better errno? */
257 goto end;
258 }
259
260 if (!((ifp->if_flags & IFF_UP) &&
261 (ifp->if_drv_flags & IFF_DRV_RUNNING)) ||
262 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) {
263 m_freem(m);
264 error = ENETDOWN;
265 goto end;
266 }
267
268 gh = NULL;
269 ip = NULL;
270
271 /* BPF writes need to be handled specially. */
272 if (dst->sa_family == AF_UNSPEC) {
273 bcopy(dst->sa_data, &af, sizeof(af));
274 dst->sa_family = af;
275 }
276
277 if (ifp->if_bpf) {
278 af = dst->sa_family;
279 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
280 }
281
282 m->m_flags &= ~(M_BCAST|M_MCAST);
283
284 if (sc->g_proto == IPPROTO_MOBILE) {
285 if (dst->sa_family == AF_INET) {
286 struct mbuf *m0;
287 int msiz;
288
289 ip = mtod(m, struct ip *);
290
291 /*
292 * RFC2004 specifies that fragmented diagrams shouldn't
293 * be encapsulated.
294 */
295 if ((ip->ip_off & IP_MF) != 0) {
296 _IF_DROP(&ifp->if_snd);
297 m_freem(m);
298 error = EINVAL; /* is there better errno? */
299 goto end;
300 }
301 memset(&mob_h, 0, MOB_H_SIZ_L);
302 mob_h.proto = (ip->ip_p) << 8;
303 mob_h.odst = ip->ip_dst.s_addr;
304 ip->ip_dst.s_addr = sc->g_dst.s_addr;
305
306 /*
307 * If the packet comes from our host, we only change
308 * the destination address in the IP header.
309 * Else we also need to save and change the source
310 */
311 if (in_hosteq(ip->ip_src, sc->g_src)) {
312 msiz = MOB_H_SIZ_S;
313 } else {
314 mob_h.proto |= MOB_H_SBIT;
315 mob_h.osrc = ip->ip_src.s_addr;
316 ip->ip_src.s_addr = sc->g_src.s_addr;
317 msiz = MOB_H_SIZ_L;
318 }
319 mob_h.proto = htons(mob_h.proto);
320 mob_h.hcrc = gre_in_cksum((u_int16_t *)&mob_h, msiz);
321
322 if ((m->m_data - msiz) < m->m_pktdat) {
323 /* need new mbuf */
324 MGETHDR(m0, M_DONTWAIT, MT_HEADER);
325 if (m0 == NULL) {
326 _IF_DROP(&ifp->if_snd);
327 m_freem(m);
328 error = ENOBUFS;
329 goto end;
330 }
331 m0->m_next = m;
332 m->m_data += sizeof(struct ip);
333 m->m_len -= sizeof(struct ip);
334 m0->m_pkthdr.len = m->m_pkthdr.len + msiz;
335 m0->m_len = msiz + sizeof(struct ip);
336 m0->m_data += max_linkhdr;
337 memcpy(mtod(m0, caddr_t), (caddr_t)ip,
338 sizeof(struct ip));
339 m = m0;
340 } else { /* we have some space left in the old one */
341 m->m_data -= msiz;
342 m->m_len += msiz;
343 m->m_pkthdr.len += msiz;
344 bcopy(ip, mtod(m, caddr_t),
345 sizeof(struct ip));
346 }
347 ip = mtod(m, struct ip *);
348 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz);
349 ip->ip_len = ntohs(ip->ip_len) + msiz;
350 } else { /* AF_INET */
351 _IF_DROP(&ifp->if_snd);
352 m_freem(m);
353 error = EINVAL;
354 goto end;
355 }
356 } else if (sc->g_proto == IPPROTO_GRE) {
357 switch (dst->sa_family) {
358 case AF_INET:
359 ip = mtod(m, struct ip *);
360 ip_tos = ip->ip_tos;
361 ip_id = ip->ip_id;
362 etype = ETHERTYPE_IP;
363 break;
364#ifdef INET6
365 case AF_INET6:
366 ip_id = ip_newid();
367 etype = ETHERTYPE_IPV6;
368 break;
369#endif
370#ifdef NETATALK
371 case AF_APPLETALK:
372 etype = ETHERTYPE_ATALK;
373 break;
374#endif
375 default:
376 _IF_DROP(&ifp->if_snd);
377 m_freem(m);
378 error = EAFNOSUPPORT;
379 goto end;
380 }
381 M_PREPEND(m, sizeof(struct greip), M_DONTWAIT);
382 } else {
383 _IF_DROP(&ifp->if_snd);
384 m_freem(m);
385 error = EINVAL;
386 goto end;
387 }
388
389 if (m == NULL) { /* mbuf allocation failed */
390 _IF_DROP(&ifp->if_snd);
391 error = ENOBUFS;
392 goto end;
393 }
394
395 gh = mtod(m, struct greip *);
396 if (sc->g_proto == IPPROTO_GRE) {
397 /* we don't have any GRE flags for now */
398 memset((void *)gh, 0, sizeof(struct greip));
399 gh->gi_ptype = htons(etype);
400 }
401
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_v = IPPROTO_IPV4;
407 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2;
408 ((struct ip*)gh)->ip_ttl = GRE_TTL;
409 ((struct ip*)gh)->ip_tos = ip_tos;
410 ((struct ip*)gh)->ip_id = ip_id;
411 gh->gi_len = m->m_pkthdr.len;
412 }
413
414 ifp->if_opackets++;
415 ifp->if_obytes += m->m_pkthdr.len;
416 /*
417 * Send it off and with IP_FORWARD flag to prevent it from
418 * overwriting the ip_id again. ip_id is already set to the
419 * ip_id of the encapsulated packet.
420 */
421 error = ip_output(m, NULL, &sc->route, IP_FORWARDING,
422 (struct ip_moptions *)NULL, (struct inpcb *)NULL);
423 end:
424 sc->called = 0;
425 if (error)
426 ifp->if_oerrors++;
427 return (error);
428}
429
430static int
431gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
432{
433 struct ifreq *ifr = (struct ifreq *)data;
434 struct if_laddrreq *lifr = (struct if_laddrreq *)data;
435 struct in_aliasreq *aifr = (struct in_aliasreq *)data;
436 struct gre_softc *sc = ifp->if_softc;
437 int s;
438 struct sockaddr_in si;
439 struct sockaddr *sa = NULL;
440 int error;
441 struct sockaddr_in sp, sm, dp, dm;
442
443 error = 0;
444
445 s = splnet();
446 switch (cmd) {
447 case SIOCSIFADDR:
448 ifp->if_flags |= IFF_UP;
449 break;
450 case SIOCSIFDSTADDR:
451 break;
452 case SIOCSIFFLAGS:
453 if ((error = suser(curthread)) != 0)
454 break;
455 if ((ifr->ifr_flags & IFF_LINK0) != 0)
456 sc->g_proto = IPPROTO_GRE;
457 else
458 sc->g_proto = IPPROTO_MOBILE;
459 if ((ifr->ifr_flags & IFF_LINK2) != 0)
460 sc->wccp_ver = WCCP_V2;
461 else
462 sc->wccp_ver = WCCP_V1;
463 goto recompute;
464 case SIOCSIFMTU:
465 if ((error = suser(curthread)) != 0)
466 break;
467 if (ifr->ifr_mtu < 576) {
468 error = EINVAL;
469 break;
470 }
471 ifp->if_mtu = ifr->ifr_mtu;
472 break;
473 case SIOCGIFMTU:
474 ifr->ifr_mtu = GRE2IFP(sc)->if_mtu;
475 break;
476 case SIOCADDMULTI:
477 case SIOCDELMULTI:
478 if ((error = suser(curthread)) != 0)
479 break;
480 if (ifr == 0) {
481 error = EAFNOSUPPORT;
482 break;
483 }
484 switch (ifr->ifr_addr.sa_family) {
485#ifdef INET
486 case AF_INET:
487 break;
488#endif
489#ifdef INET6
490 case AF_INET6:
491 break;
492#endif
493 default:
494 error = EAFNOSUPPORT;
495 break;
496 }
497 break;
498 case GRESPROTO:
499 if ((error = suser(curthread)) != 0)
500 break;
501 sc->g_proto = ifr->ifr_flags;
502 switch (sc->g_proto) {
503 case IPPROTO_GRE:
504 ifp->if_flags |= IFF_LINK0;
505 break;
506 case IPPROTO_MOBILE:
507 ifp->if_flags &= ~IFF_LINK0;
508 break;
509 default:
510 error = EPROTONOSUPPORT;
511 break;
512 }
513 goto recompute;
514 case GREGPROTO:
515 ifr->ifr_flags = sc->g_proto;
516 break;
517 case GRESADDRS:
518 case GRESADDRD:
519 if ((error = suser(curthread)) != 0)
520 break;
521 /*
522 * set tunnel endpoints, compute a less specific route
523 * to the remote end and mark if as up
524 */
525 sa = &ifr->ifr_addr;
526 if (cmd == GRESADDRS)
527 sc->g_src = (satosin(sa))->sin_addr;
528 if (cmd == GRESADDRD)
529 sc->g_dst = (satosin(sa))->sin_addr;
530 recompute:
531#ifdef INET
532 if (sc->encap != NULL) {
533 encap_detach(sc->encap);
534 sc->encap = NULL;
535 }
536#endif
537 if ((sc->g_src.s_addr != INADDR_ANY) &&
538 (sc->g_dst.s_addr != INADDR_ANY)) {
539 bzero(&sp, sizeof(sp));
540 bzero(&sm, sizeof(sm));
541 bzero(&dp, sizeof(dp));
542 bzero(&dm, sizeof(dm));
543 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len =
544 sizeof(struct sockaddr_in);
545 sp.sin_family = sm.sin_family = dp.sin_family =
546 dm.sin_family = AF_INET;
547 sp.sin_addr = sc->g_src;
548 dp.sin_addr = sc->g_dst;
549 sm.sin_addr.s_addr = dm.sin_addr.s_addr =
550 INADDR_BROADCAST;
551#ifdef INET
552 sc->encap = encap_attach(AF_INET, sc->g_proto,
553 sintosa(&sp), sintosa(&sm), sintosa(&dp),
554 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ?
555 &in_gre_protosw : &in_mobile_protosw, sc);
556 if (sc->encap == NULL)
557 printf("%s: unable to attach encap\n",
558 if_name(GRE2IFP(sc)));
559#endif
560 if (sc->route.ro_rt != 0) /* free old route */
561 RTFREE(sc->route.ro_rt);
562 if (gre_compute_route(sc) == 0)
563 ifp->if_drv_flags |= IFF_DRV_RUNNING;
564 else
565 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
566 }
567 break;
568 case GREGADDRS:
569 memset(&si, 0, sizeof(si));
570 si.sin_family = AF_INET;
571 si.sin_len = sizeof(struct sockaddr_in);
572 si.sin_addr.s_addr = sc->g_src.s_addr;
573 sa = sintosa(&si);
574 ifr->ifr_addr = *sa;
575 break;
576 case GREGADDRD:
577 memset(&si, 0, sizeof(si));
578 si.sin_family = AF_INET;
579 si.sin_len = sizeof(struct sockaddr_in);
580 si.sin_addr.s_addr = sc->g_dst.s_addr;
581 sa = sintosa(&si);
582 ifr->ifr_addr = *sa;
583 break;
584 case SIOCSIFPHYADDR:
585 if ((error = suser(curthread)) != 0)
586 break;
587 if (aifr->ifra_addr.sin_family != AF_INET ||
588 aifr->ifra_dstaddr.sin_family != AF_INET) {
589 error = EAFNOSUPPORT;
590 break;
591 }
592 if (aifr->ifra_addr.sin_len != sizeof(si) ||
593 aifr->ifra_dstaddr.sin_len != sizeof(si)) {
594 error = EINVAL;
595 break;
596 }
597 sc->g_src = aifr->ifra_addr.sin_addr;
598 sc->g_dst = aifr->ifra_dstaddr.sin_addr;
599 goto recompute;
600 case SIOCSLIFPHYADDR:
601 if ((error = suser(curthread)) != 0)
602 break;
603 if (lifr->addr.ss_family != AF_INET ||
604 lifr->dstaddr.ss_family != AF_INET) {
605 error = EAFNOSUPPORT;
606 break;
607 }
608 if (lifr->addr.ss_len != sizeof(si) ||
609 lifr->dstaddr.ss_len != sizeof(si)) {
610 error = EINVAL;
611 break;
612 }
613 sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr;
614 sc->g_dst =
615 (satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr;
616 goto recompute;
617 case SIOCDIFPHYADDR:
618 if ((error = suser(curthread)) != 0)
619 break;
620 sc->g_src.s_addr = INADDR_ANY;
621 sc->g_dst.s_addr = INADDR_ANY;
622 goto recompute;
623 case SIOCGLIFPHYADDR:
624 if (sc->g_src.s_addr == INADDR_ANY ||
625 sc->g_dst.s_addr == INADDR_ANY) {
626 error = EADDRNOTAVAIL;
627 break;
628 }
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 memcpy(&lifr->addr, &si, sizeof(si));
634 si.sin_addr.s_addr = sc->g_dst.s_addr;
635 memcpy(&lifr->dstaddr, &si, sizeof(si));
636 break;
637 case SIOCGIFPSRCADDR:
638#ifdef INET6
639 case SIOCGIFPSRCADDR_IN6:
640#endif
641 if (sc->g_src.s_addr == INADDR_ANY) {
642 error = EADDRNOTAVAIL;
643 break;
644 }
645 memset(&si, 0, sizeof(si));
646 si.sin_family = AF_INET;
647 si.sin_len = sizeof(struct sockaddr_in);
648 si.sin_addr.s_addr = sc->g_src.s_addr;
649 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
650 break;
651 case SIOCGIFPDSTADDR:
652#ifdef INET6
653 case SIOCGIFPDSTADDR_IN6:
654#endif
655 if (sc->g_dst.s_addr == INADDR_ANY) {
656 error = EADDRNOTAVAIL;
657 break;
658 }
659 memset(&si, 0, sizeof(si));
660 si.sin_family = AF_INET;
661 si.sin_len = sizeof(struct sockaddr_in);
662 si.sin_addr.s_addr = sc->g_dst.s_addr;
663 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
664 break;
665 default:
666 error = EINVAL;
667 break;
668 }
669
670 splx(s);
671 return (error);
672}
673
674/*
675 * computes a route to our destination that is not the one
676 * which would be taken by ip_output(), as this one will loop back to
677 * us. If the interface is p2p as a--->b, then a routing entry exists
678 * If we now send a packet to b (e.g. ping b), this will come down here
679 * gets src=a, dst=b tacked on and would from ip_output() sent back to
680 * if_gre.
681 * Goal here is to compute a route to b that is less specific than
682 * a-->b. We know that this one exists as in normal operation we have
683 * at least a default route which matches.
684 */
685static int
686gre_compute_route(struct gre_softc *sc)
687{
688 struct route *ro;
689 u_int32_t a, b, c;
690
691 ro = &sc->route;
692
693 memset(ro, 0, sizeof(struct route));
694 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
695 ro->ro_dst.sa_family = AF_INET;
696 ro->ro_dst.sa_len = sizeof(ro->ro_dst);
697
698 /*
699 * toggle last bit, so our interface is not found, but a less
700 * specific route. I'd rather like to specify a shorter mask,
701 * but this is not possible. Should work though. XXX
702 * there is a simpler way ...
703 */
704 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) {
705 a = ntohl(sc->g_dst.s_addr);
706 b = a & 0x01;
707 c = a & 0xfffffffe;
708 b = b ^ 0x01;
709 a = b | c;
710 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr
711 = htonl(a);
712 }
713
714#ifdef DIAGNOSTIC
715 printf("%s: searching for a route to %s", if_name(GRE2IFP(sc)),
716 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr));
717#endif
718
719 rtalloc(ro);
720
721 /*
722 * check if this returned a route at all and this route is no
723 * recursion to ourself
724 */
725 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) {
726#ifdef DIAGNOSTIC
727 if (ro->ro_rt == NULL)
728 printf(" - no route found!\n");
729 else
730 printf(" - route loops back to ourself!\n");
731#endif
732 return EADDRNOTAVAIL;
733 }
734
735 /*
736 * now change it back - else ip_output will just drop
737 * the route and search one to this interface ...
738 */
739 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0)
740 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
741
742#ifdef DIAGNOSTIC
743 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp),
744 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr));
745 printf("\n");
746#endif
747
748 return 0;
749}
750
751/*
752 * do a checksum of a buffer - much like in_cksum, which operates on
753 * mbufs.
754 */
755u_int16_t
756gre_in_cksum(u_int16_t *p, u_int len)
757{
758 u_int32_t sum = 0;
759 int nwords = len >> 1;
760
761 while (nwords-- != 0)
762 sum += *p++;
763
764 if (len & 1) {
765 union {
766 u_short w;
767 u_char c[2];
768 } u;
769 u.c[0] = *(u_char *)p;
770 u.c[1] = 0;
771 sum += u.w;
772 }
773
774 /* end-around-carry */
775 sum = (sum >> 16) + (sum & 0xffff);
776 sum += (sum >> 16);
777 return (~sum);
778}
779
780static int
781gremodevent(module_t mod, int type, void *data)
782{
783 struct gre_softc *sc;
784
785 switch (type) {
786 case MOD_LOAD:
787 greattach();
788 break;
789 case MOD_UNLOAD:
790 if_clone_detach(&gre_cloner);
791
792 mtx_lock(&gre_mtx);
793 while ((sc = LIST_FIRST(&gre_softc_list)) != NULL) {
794 LIST_REMOVE(sc, sc_list);
795 mtx_unlock(&gre_mtx);
796 gre_destroy(sc);
797 mtx_lock(&gre_mtx);
798 }
799 mtx_unlock(&gre_mtx);
800 mtx_destroy(&gre_mtx);
801 break;
802 default:
803 return EOPNOTSUPP;
804 }
805 return 0;
806}
807
808static moduledata_t gre_mod = {
809 "if_gre",
810 gremodevent,
811 0
812};
813
814DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
815MODULE_VERSION(if_gre, 1);