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 .pr_type = SOCK_RAW,
123 .pr_domain = &inetdomain,
124 .pr_protocol = IPPROTO_GRE,
125 .pr_flags = PR_ATOMIC|PR_ADDR,
| 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 .pr_type = SOCK_RAW,
123 .pr_domain = &inetdomain,
124 .pr_protocol = IPPROTO_GRE,
125 .pr_flags = PR_ATOMIC|PR_ADDR,
|
138 .pr_output = (pr_output_t *)rip_output,
139 .pr_ctlinput = rip_ctlinput,
140 .pr_ctloutput = rip_ctloutput,
141 .pr_usrreqs = &rip_usrreqs
142};
143#endif
144
145SYSCTL_DECL(_net_link);
146SYSCTL_NODE(_net_link, IFT_TUNNEL, gre, CTLFLAG_RW, 0,
147 "Generic Routing Encapsulation");
148#ifndef MAX_GRE_NEST
149/*
150 * This macro controls the default upper limitation on nesting of gre tunnels.
151 * Since, setting a large value to this macro with a careless configuration
152 * may introduce system crash, we don't allow any nestings by default.
153 * If you need to configure nested gre tunnels, you can define this macro
154 * in your kernel configuration file. However, if you do so, please be
155 * careful to configure the tunnels so that it won't make a loop.
156 */
157#define MAX_GRE_NEST 1
158#endif
159static int max_gre_nesting = MAX_GRE_NEST;
160SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW,
161 &max_gre_nesting, 0, "Max nested tunnels");
162
163/* ARGSUSED */
164static void
165greattach(void)
166{
167
168 mtx_init(&gre_mtx, "gre_mtx", NULL, MTX_DEF);
169 LIST_INIT(&gre_softc_list);
170 if_clone_attach(&gre_cloner);
171}
172
173static int
174gre_clone_create(ifc, unit)
175 struct if_clone *ifc;
176 int unit;
177{
178 struct gre_softc *sc;
179
180 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK | M_ZERO);
181
182 GRE2IFP(sc) = if_alloc(IFT_TUNNEL);
183 if (GRE2IFP(sc) == NULL) {
184 free(sc, M_GRE);
185 return (ENOSPC);
186 }
187
188 GRE2IFP(sc)->if_softc = sc;
189 if_initname(GRE2IFP(sc), ifc->ifc_name, unit);
190
191 GRE2IFP(sc)->if_snd.ifq_maxlen = IFQ_MAXLEN;
192 GRE2IFP(sc)->if_addrlen = 0;
193 GRE2IFP(sc)->if_hdrlen = 24; /* IP + GRE */
194 GRE2IFP(sc)->if_mtu = GREMTU;
195 GRE2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
196 GRE2IFP(sc)->if_output = gre_output;
197 GRE2IFP(sc)->if_ioctl = gre_ioctl;
198 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY;
199 sc->g_proto = IPPROTO_GRE;
200 GRE2IFP(sc)->if_flags |= IFF_LINK0;
201 sc->encap = NULL;
202 sc->called = 0;
203 sc->wccp_ver = WCCP_V1;
204 if_attach(GRE2IFP(sc));
205 bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t));
206 mtx_lock(&gre_mtx);
207 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list);
208 mtx_unlock(&gre_mtx);
209 return (0);
210}
211
212static void
213gre_clone_destroy(ifp)
214 struct ifnet *ifp;
215{
216 struct gre_softc *sc = ifp->if_softc;
217
218 mtx_lock(&gre_mtx);
219 LIST_REMOVE(sc, sc_list);
220 mtx_unlock(&gre_mtx);
221
222#ifdef INET
223 if (sc->encap != NULL)
224 encap_detach(sc->encap);
225#endif
226 bpfdetach(ifp);
227 if_detach(ifp);
228 if_free(ifp);
229 free(sc, M_GRE);
230}
231
232/*
233 * The output routine. Takes a packet and encapsulates it in the protocol
234 * given by sc->g_proto. See also RFC 1701 and RFC 2004
235 */
236static int
237gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
238 struct rtentry *rt)
239{
240 int error = 0;
241 struct gre_softc *sc = ifp->if_softc;
242 struct greip *gh;
243 struct ip *ip;
244 u_short ip_id = 0;
245 uint8_t ip_tos = 0;
246 u_int16_t etype = 0;
247 struct mobile_h mob_h;
248 u_int32_t af;
249
250 /*
251 * gre may cause infinite recursion calls when misconfigured.
252 * We'll prevent this by introducing upper limit.
253 */
254 if (++(sc->called) > max_gre_nesting) {
255 printf("%s: gre_output: recursively called too many "
256 "times(%d)\n", if_name(GRE2IFP(sc)), sc->called);
257 m_freem(m);
258 error = EIO; /* is there better errno? */
259 goto end;
260 }
261
262 if (!((ifp->if_flags & IFF_UP) &&
263 (ifp->if_drv_flags & IFF_DRV_RUNNING)) ||
264 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) {
265 m_freem(m);
266 error = ENETDOWN;
267 goto end;
268 }
269
270 gh = NULL;
271 ip = NULL;
272
273 /* BPF writes need to be handled specially. */
274 if (dst->sa_family == AF_UNSPEC) {
275 bcopy(dst->sa_data, &af, sizeof(af));
276 dst->sa_family = af;
277 }
278
279 if (ifp->if_bpf) {
280 af = dst->sa_family;
281 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
282 }
283
284 m->m_flags &= ~(M_BCAST|M_MCAST);
285
286 if (sc->g_proto == IPPROTO_MOBILE) {
287 if (dst->sa_family == AF_INET) {
288 struct mbuf *m0;
289 int msiz;
290
291 ip = mtod(m, struct ip *);
292
293 /*
294 * RFC2004 specifies that fragmented diagrams shouldn't
295 * be encapsulated.
296 */
297 if ((ip->ip_off & IP_MF) != 0) {
298 _IF_DROP(&ifp->if_snd);
299 m_freem(m);
300 error = EINVAL; /* is there better errno? */
301 goto end;
302 }
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;
307
308 /*
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
312 */
313 if (in_hosteq(ip->ip_src, sc->g_src)) {
314 msiz = MOB_H_SIZ_S;
315 } else {
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;
319 msiz = MOB_H_SIZ_L;
320 }
321 mob_h.proto = htons(mob_h.proto);
322 mob_h.hcrc = gre_in_cksum((u_int16_t *)&mob_h, msiz);
323
324 if ((m->m_data - msiz) < m->m_pktdat) {
325 /* need new mbuf */
326 MGETHDR(m0, M_DONTWAIT, MT_DATA);
327 if (m0 == NULL) {
328 _IF_DROP(&ifp->if_snd);
329 m_freem(m);
330 error = ENOBUFS;
331 goto end;
332 }
333 m0->m_next = m;
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,
340 sizeof(struct ip));
341 m = m0;
342 } else { /* we have some space left in the old one */
343 m->m_data -= msiz;
344 m->m_len += msiz;
345 m->m_pkthdr.len += msiz;
346 bcopy(ip, mtod(m, caddr_t),
347 sizeof(struct ip));
348 }
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);
354 m_freem(m);
355 error = EINVAL;
356 goto end;
357 }
358 } else if (sc->g_proto == IPPROTO_GRE) {
359 switch (dst->sa_family) {
360 case AF_INET:
361 ip = mtod(m, struct ip *);
362 ip_tos = ip->ip_tos;
363 ip_id = ip->ip_id;
364 etype = ETHERTYPE_IP;
365 break;
366#ifdef INET6
367 case AF_INET6:
368 ip_id = ip_newid();
369 etype = ETHERTYPE_IPV6;
370 break;
371#endif
372#ifdef NETATALK
373 case AF_APPLETALK:
374 etype = ETHERTYPE_ATALK;
375 break;
376#endif
377 default:
378 _IF_DROP(&ifp->if_snd);
379 m_freem(m);
380 error = EAFNOSUPPORT;
381 goto end;
382 }
383 M_PREPEND(m, sizeof(struct greip), M_DONTWAIT);
384 } else {
385 _IF_DROP(&ifp->if_snd);
386 m_freem(m);
387 error = EINVAL;
388 goto end;
389 }
390
391 if (m == NULL) { /* mbuf allocation failed */
392 _IF_DROP(&ifp->if_snd);
393 error = ENOBUFS;
394 goto end;
395 }
396
397 gh = mtod(m, struct greip *);
398 if (sc->g_proto == IPPROTO_GRE) {
399 /* we don't have any GRE flags for now */
400 memset((void *)gh, 0, sizeof(struct greip));
401 gh->gi_ptype = htons(etype);
402 }
403
404 gh->gi_pr = sc->g_proto;
405 if (sc->g_proto != IPPROTO_MOBILE) {
406 gh->gi_src = sc->g_src;
407 gh->gi_dst = sc->g_dst;
408 ((struct ip*)gh)->ip_v = IPPROTO_IPV4;
409 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2;
410 ((struct ip*)gh)->ip_ttl = GRE_TTL;
411 ((struct ip*)gh)->ip_tos = ip_tos;
412 ((struct ip*)gh)->ip_id = ip_id;
413 gh->gi_len = m->m_pkthdr.len;
414 }
415
416 ifp->if_opackets++;
417 ifp->if_obytes += m->m_pkthdr.len;
418 /*
419 * Send it off and with IP_FORWARD flag to prevent it from
420 * overwriting the ip_id again. ip_id is already set to the
421 * ip_id of the encapsulated packet.
422 */
423 error = ip_output(m, NULL, &sc->route, IP_FORWARDING,
424 (struct ip_moptions *)NULL, (struct inpcb *)NULL);
425 end:
426 sc->called = 0;
427 if (error)
428 ifp->if_oerrors++;
429 return (error);
430}
431
432static int
433gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
434{
435 struct ifreq *ifr = (struct ifreq *)data;
436 struct if_laddrreq *lifr = (struct if_laddrreq *)data;
437 struct in_aliasreq *aifr = (struct in_aliasreq *)data;
438 struct gre_softc *sc = ifp->if_softc;
439 int s;
440 struct sockaddr_in si;
441 struct sockaddr *sa = NULL;
442 int error;
443 struct sockaddr_in sp, sm, dp, dm;
444
445 error = 0;
446
447 s = splnet();
448 switch (cmd) {
449 case SIOCSIFADDR:
450 ifp->if_flags |= IFF_UP;
451 break;
452 case SIOCSIFDSTADDR:
453 break;
454 case SIOCSIFFLAGS:
455 if ((error = suser(curthread)) != 0)
456 break;
457 if ((ifr->ifr_flags & IFF_LINK0) != 0)
458 sc->g_proto = IPPROTO_GRE;
459 else
460 sc->g_proto = IPPROTO_MOBILE;
461 if ((ifr->ifr_flags & IFF_LINK2) != 0)
462 sc->wccp_ver = WCCP_V2;
463 else
464 sc->wccp_ver = WCCP_V1;
465 goto recompute;
466 case SIOCSIFMTU:
467 if ((error = suser(curthread)) != 0)
468 break;
469 if (ifr->ifr_mtu < 576) {
470 error = EINVAL;
471 break;
472 }
473 ifp->if_mtu = ifr->ifr_mtu;
474 break;
475 case SIOCGIFMTU:
476 ifr->ifr_mtu = GRE2IFP(sc)->if_mtu;
477 break;
478 case SIOCADDMULTI:
479 case SIOCDELMULTI:
480 if ((error = suser(curthread)) != 0)
481 break;
482 if (ifr == 0) {
483 error = EAFNOSUPPORT;
484 break;
485 }
486 switch (ifr->ifr_addr.sa_family) {
487#ifdef INET
488 case AF_INET:
489 break;
490#endif
491#ifdef INET6
492 case AF_INET6:
493 break;
494#endif
495 default:
496 error = EAFNOSUPPORT;
497 break;
498 }
499 break;
500 case GRESPROTO:
501 if ((error = suser(curthread)) != 0)
502 break;
503 sc->g_proto = ifr->ifr_flags;
504 switch (sc->g_proto) {
505 case IPPROTO_GRE:
506 ifp->if_flags |= IFF_LINK0;
507 break;
508 case IPPROTO_MOBILE:
509 ifp->if_flags &= ~IFF_LINK0;
510 break;
511 default:
512 error = EPROTONOSUPPORT;
513 break;
514 }
515 goto recompute;
516 case GREGPROTO:
517 ifr->ifr_flags = sc->g_proto;
518 break;
519 case GRESADDRS:
520 case GRESADDRD:
521 if ((error = suser(curthread)) != 0)
522 break;
523 /*
524 * set tunnel endpoints, compute a less specific route
525 * to the remote end and mark if as up
526 */
527 sa = &ifr->ifr_addr;
528 if (cmd == GRESADDRS)
529 sc->g_src = (satosin(sa))->sin_addr;
530 if (cmd == GRESADDRD)
531 sc->g_dst = (satosin(sa))->sin_addr;
532 recompute:
533#ifdef INET
534 if (sc->encap != NULL) {
535 encap_detach(sc->encap);
536 sc->encap = NULL;
537 }
538#endif
539 if ((sc->g_src.s_addr != INADDR_ANY) &&
540 (sc->g_dst.s_addr != INADDR_ANY)) {
541 bzero(&sp, sizeof(sp));
542 bzero(&sm, sizeof(sm));
543 bzero(&dp, sizeof(dp));
544 bzero(&dm, sizeof(dm));
545 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len =
546 sizeof(struct sockaddr_in);
547 sp.sin_family = sm.sin_family = dp.sin_family =
548 dm.sin_family = AF_INET;
549 sp.sin_addr = sc->g_src;
550 dp.sin_addr = sc->g_dst;
551 sm.sin_addr.s_addr = dm.sin_addr.s_addr =
552 INADDR_BROADCAST;
553#ifdef INET
554 sc->encap = encap_attach(AF_INET, sc->g_proto,
555 sintosa(&sp), sintosa(&sm), sintosa(&dp),
556 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ?
557 &in_gre_protosw : &in_mobile_protosw, sc);
558 if (sc->encap == NULL)
559 printf("%s: unable to attach encap\n",
560 if_name(GRE2IFP(sc)));
561#endif
562 if (sc->route.ro_rt != 0) /* free old route */
563 RTFREE(sc->route.ro_rt);
564 if (gre_compute_route(sc) == 0)
565 ifp->if_drv_flags |= IFF_DRV_RUNNING;
566 else
567 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
568 }
569 break;
570 case GREGADDRS:
571 memset(&si, 0, sizeof(si));
572 si.sin_family = AF_INET;
573 si.sin_len = sizeof(struct sockaddr_in);
574 si.sin_addr.s_addr = sc->g_src.s_addr;
575 sa = sintosa(&si);
576 ifr->ifr_addr = *sa;
577 break;
578 case GREGADDRD:
579 memset(&si, 0, sizeof(si));
580 si.sin_family = AF_INET;
581 si.sin_len = sizeof(struct sockaddr_in);
582 si.sin_addr.s_addr = sc->g_dst.s_addr;
583 sa = sintosa(&si);
584 ifr->ifr_addr = *sa;
585 break;
586 case SIOCSIFPHYADDR:
587 if ((error = suser(curthread)) != 0)
588 break;
589 if (aifr->ifra_addr.sin_family != AF_INET ||
590 aifr->ifra_dstaddr.sin_family != AF_INET) {
591 error = EAFNOSUPPORT;
592 break;
593 }
594 if (aifr->ifra_addr.sin_len != sizeof(si) ||
595 aifr->ifra_dstaddr.sin_len != sizeof(si)) {
596 error = EINVAL;
597 break;
598 }
599 sc->g_src = aifr->ifra_addr.sin_addr;
600 sc->g_dst = aifr->ifra_dstaddr.sin_addr;
601 goto recompute;
602 case SIOCSLIFPHYADDR:
603 if ((error = suser(curthread)) != 0)
604 break;
605 if (lifr->addr.ss_family != AF_INET ||
606 lifr->dstaddr.ss_family != AF_INET) {
607 error = EAFNOSUPPORT;
608 break;
609 }
610 if (lifr->addr.ss_len != sizeof(si) ||
611 lifr->dstaddr.ss_len != sizeof(si)) {
612 error = EINVAL;
613 break;
614 }
615 sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr;
616 sc->g_dst =
617 (satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr;
618 goto recompute;
619 case SIOCDIFPHYADDR:
620 if ((error = suser(curthread)) != 0)
621 break;
622 sc->g_src.s_addr = INADDR_ANY;
623 sc->g_dst.s_addr = INADDR_ANY;
624 goto recompute;
625 case SIOCGLIFPHYADDR:
626 if (sc->g_src.s_addr == INADDR_ANY ||
627 sc->g_dst.s_addr == INADDR_ANY) {
628 error = EADDRNOTAVAIL;
629 break;
630 }
631 memset(&si, 0, sizeof(si));
632 si.sin_family = AF_INET;
633 si.sin_len = sizeof(struct sockaddr_in);
634 si.sin_addr.s_addr = sc->g_src.s_addr;
635 memcpy(&lifr->addr, &si, sizeof(si));
636 si.sin_addr.s_addr = sc->g_dst.s_addr;
637 memcpy(&lifr->dstaddr, &si, sizeof(si));
638 break;
639 case SIOCGIFPSRCADDR:
640#ifdef INET6
641 case SIOCGIFPSRCADDR_IN6:
642#endif
643 if (sc->g_src.s_addr == INADDR_ANY) {
644 error = EADDRNOTAVAIL;
645 break;
646 }
647 memset(&si, 0, sizeof(si));
648 si.sin_family = AF_INET;
649 si.sin_len = sizeof(struct sockaddr_in);
650 si.sin_addr.s_addr = sc->g_src.s_addr;
651 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
652 break;
653 case SIOCGIFPDSTADDR:
654#ifdef INET6
655 case SIOCGIFPDSTADDR_IN6:
656#endif
657 if (sc->g_dst.s_addr == INADDR_ANY) {
658 error = EADDRNOTAVAIL;
659 break;
660 }
661 memset(&si, 0, sizeof(si));
662 si.sin_family = AF_INET;
663 si.sin_len = sizeof(struct sockaddr_in);
664 si.sin_addr.s_addr = sc->g_dst.s_addr;
665 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
666 break;
667 default:
668 error = EINVAL;
669 break;
670 }
671
672 splx(s);
673 return (error);
674}
675
676/*
677 * computes a route to our destination that is not the one
678 * which would be taken by ip_output(), as this one will loop back to
679 * us. If the interface is p2p as a--->b, then a routing entry exists
680 * If we now send a packet to b (e.g. ping b), this will come down here
681 * gets src=a, dst=b tacked on and would from ip_output() sent back to
682 * if_gre.
683 * Goal here is to compute a route to b that is less specific than
684 * a-->b. We know that this one exists as in normal operation we have
685 * at least a default route which matches.
686 */
687static int
688gre_compute_route(struct gre_softc *sc)
689{
690 struct route *ro;
691 u_int32_t a, b, c;
692
693 ro = &sc->route;
694
695 memset(ro, 0, sizeof(struct route));
696 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
697 ro->ro_dst.sa_family = AF_INET;
698 ro->ro_dst.sa_len = sizeof(ro->ro_dst);
699
700 /*
701 * toggle last bit, so our interface is not found, but a less
702 * specific route. I'd rather like to specify a shorter mask,
703 * but this is not possible. Should work though. XXX
704 * there is a simpler way ...
705 */
706 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) {
707 a = ntohl(sc->g_dst.s_addr);
708 b = a & 0x01;
709 c = a & 0xfffffffe;
710 b = b ^ 0x01;
711 a = b | c;
712 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr
713 = htonl(a);
714 }
715
716#ifdef DIAGNOSTIC
717 printf("%s: searching for a route to %s", if_name(GRE2IFP(sc)),
718 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr));
719#endif
720
721 rtalloc(ro);
722
723 /*
724 * check if this returned a route at all and this route is no
725 * recursion to ourself
726 */
727 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) {
728#ifdef DIAGNOSTIC
729 if (ro->ro_rt == NULL)
730 printf(" - no route found!\n");
731 else
732 printf(" - route loops back to ourself!\n");
733#endif
734 return EADDRNOTAVAIL;
735 }
736
737 /*
738 * now change it back - else ip_output will just drop
739 * the route and search one to this interface ...
740 */
741 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0)
742 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
743
744#ifdef DIAGNOSTIC
745 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp),
746 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr));
747 printf("\n");
748#endif
749
750 return 0;
751}
752
753/*
754 * do a checksum of a buffer - much like in_cksum, which operates on
755 * mbufs.
756 */
757u_int16_t
758gre_in_cksum(u_int16_t *p, u_int len)
759{
760 u_int32_t sum = 0;
761 int nwords = len >> 1;
762
763 while (nwords-- != 0)
764 sum += *p++;
765
766 if (len & 1) {
767 union {
768 u_short w;
769 u_char c[2];
770 } u;
771 u.c[0] = *(u_char *)p;
772 u.c[1] = 0;
773 sum += u.w;
774 }
775
776 /* end-around-carry */
777 sum = (sum >> 16) + (sum & 0xffff);
778 sum += (sum >> 16);
779 return (~sum);
780}
781
782static int
783gremodevent(module_t mod, int type, void *data)
784{
785
786 switch (type) {
787 case MOD_LOAD:
788 greattach();
789 break;
790 case MOD_UNLOAD:
791 if_clone_detach(&gre_cloner);
792 mtx_destroy(&gre_mtx);
793 break;
794 default:
795 return EOPNOTSUPP;
796 }
797 return 0;
798}
799
800static moduledata_t gre_mod = {
801 "if_gre",
802 gremodevent,
803 0
804};
805
806DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
807MODULE_VERSION(if_gre, 1);
| 138 .pr_output = (pr_output_t *)rip_output,
139 .pr_ctlinput = rip_ctlinput,
140 .pr_ctloutput = rip_ctloutput,
141 .pr_usrreqs = &rip_usrreqs
142};
143#endif
144
145SYSCTL_DECL(_net_link);
146SYSCTL_NODE(_net_link, IFT_TUNNEL, gre, CTLFLAG_RW, 0,
147 "Generic Routing Encapsulation");
148#ifndef MAX_GRE_NEST
149/*
150 * This macro controls the default upper limitation on nesting of gre tunnels.
151 * Since, setting a large value to this macro with a careless configuration
152 * may introduce system crash, we don't allow any nestings by default.
153 * If you need to configure nested gre tunnels, you can define this macro
154 * in your kernel configuration file. However, if you do so, please be
155 * careful to configure the tunnels so that it won't make a loop.
156 */
157#define MAX_GRE_NEST 1
158#endif
159static int max_gre_nesting = MAX_GRE_NEST;
160SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW,
161 &max_gre_nesting, 0, "Max nested tunnels");
162
163/* ARGSUSED */
164static void
165greattach(void)
166{
167
168 mtx_init(&gre_mtx, "gre_mtx", NULL, MTX_DEF);
169 LIST_INIT(&gre_softc_list);
170 if_clone_attach(&gre_cloner);
171}
172
173static int
174gre_clone_create(ifc, unit)
175 struct if_clone *ifc;
176 int unit;
177{
178 struct gre_softc *sc;
179
180 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK | M_ZERO);
181
182 GRE2IFP(sc) = if_alloc(IFT_TUNNEL);
183 if (GRE2IFP(sc) == NULL) {
184 free(sc, M_GRE);
185 return (ENOSPC);
186 }
187
188 GRE2IFP(sc)->if_softc = sc;
189 if_initname(GRE2IFP(sc), ifc->ifc_name, unit);
190
191 GRE2IFP(sc)->if_snd.ifq_maxlen = IFQ_MAXLEN;
192 GRE2IFP(sc)->if_addrlen = 0;
193 GRE2IFP(sc)->if_hdrlen = 24; /* IP + GRE */
194 GRE2IFP(sc)->if_mtu = GREMTU;
195 GRE2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
196 GRE2IFP(sc)->if_output = gre_output;
197 GRE2IFP(sc)->if_ioctl = gre_ioctl;
198 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY;
199 sc->g_proto = IPPROTO_GRE;
200 GRE2IFP(sc)->if_flags |= IFF_LINK0;
201 sc->encap = NULL;
202 sc->called = 0;
203 sc->wccp_ver = WCCP_V1;
204 if_attach(GRE2IFP(sc));
205 bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t));
206 mtx_lock(&gre_mtx);
207 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list);
208 mtx_unlock(&gre_mtx);
209 return (0);
210}
211
212static void
213gre_clone_destroy(ifp)
214 struct ifnet *ifp;
215{
216 struct gre_softc *sc = ifp->if_softc;
217
218 mtx_lock(&gre_mtx);
219 LIST_REMOVE(sc, sc_list);
220 mtx_unlock(&gre_mtx);
221
222#ifdef INET
223 if (sc->encap != NULL)
224 encap_detach(sc->encap);
225#endif
226 bpfdetach(ifp);
227 if_detach(ifp);
228 if_free(ifp);
229 free(sc, M_GRE);
230}
231
232/*
233 * The output routine. Takes a packet and encapsulates it in the protocol
234 * given by sc->g_proto. See also RFC 1701 and RFC 2004
235 */
236static int
237gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
238 struct rtentry *rt)
239{
240 int error = 0;
241 struct gre_softc *sc = ifp->if_softc;
242 struct greip *gh;
243 struct ip *ip;
244 u_short ip_id = 0;
245 uint8_t ip_tos = 0;
246 u_int16_t etype = 0;
247 struct mobile_h mob_h;
248 u_int32_t af;
249
250 /*
251 * gre may cause infinite recursion calls when misconfigured.
252 * We'll prevent this by introducing upper limit.
253 */
254 if (++(sc->called) > max_gre_nesting) {
255 printf("%s: gre_output: recursively called too many "
256 "times(%d)\n", if_name(GRE2IFP(sc)), sc->called);
257 m_freem(m);
258 error = EIO; /* is there better errno? */
259 goto end;
260 }
261
262 if (!((ifp->if_flags & IFF_UP) &&
263 (ifp->if_drv_flags & IFF_DRV_RUNNING)) ||
264 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) {
265 m_freem(m);
266 error = ENETDOWN;
267 goto end;
268 }
269
270 gh = NULL;
271 ip = NULL;
272
273 /* BPF writes need to be handled specially. */
274 if (dst->sa_family == AF_UNSPEC) {
275 bcopy(dst->sa_data, &af, sizeof(af));
276 dst->sa_family = af;
277 }
278
279 if (ifp->if_bpf) {
280 af = dst->sa_family;
281 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
282 }
283
284 m->m_flags &= ~(M_BCAST|M_MCAST);
285
286 if (sc->g_proto == IPPROTO_MOBILE) {
287 if (dst->sa_family == AF_INET) {
288 struct mbuf *m0;
289 int msiz;
290
291 ip = mtod(m, struct ip *);
292
293 /*
294 * RFC2004 specifies that fragmented diagrams shouldn't
295 * be encapsulated.
296 */
297 if ((ip->ip_off & IP_MF) != 0) {
298 _IF_DROP(&ifp->if_snd);
299 m_freem(m);
300 error = EINVAL; /* is there better errno? */
301 goto end;
302 }
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;
307
308 /*
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
312 */
313 if (in_hosteq(ip->ip_src, sc->g_src)) {
314 msiz = MOB_H_SIZ_S;
315 } else {
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;
319 msiz = MOB_H_SIZ_L;
320 }
321 mob_h.proto = htons(mob_h.proto);
322 mob_h.hcrc = gre_in_cksum((u_int16_t *)&mob_h, msiz);
323
324 if ((m->m_data - msiz) < m->m_pktdat) {
325 /* need new mbuf */
326 MGETHDR(m0, M_DONTWAIT, MT_DATA);
327 if (m0 == NULL) {
328 _IF_DROP(&ifp->if_snd);
329 m_freem(m);
330 error = ENOBUFS;
331 goto end;
332 }
333 m0->m_next = m;
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,
340 sizeof(struct ip));
341 m = m0;
342 } else { /* we have some space left in the old one */
343 m->m_data -= msiz;
344 m->m_len += msiz;
345 m->m_pkthdr.len += msiz;
346 bcopy(ip, mtod(m, caddr_t),
347 sizeof(struct ip));
348 }
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);
354 m_freem(m);
355 error = EINVAL;
356 goto end;
357 }
358 } else if (sc->g_proto == IPPROTO_GRE) {
359 switch (dst->sa_family) {
360 case AF_INET:
361 ip = mtod(m, struct ip *);
362 ip_tos = ip->ip_tos;
363 ip_id = ip->ip_id;
364 etype = ETHERTYPE_IP;
365 break;
366#ifdef INET6
367 case AF_INET6:
368 ip_id = ip_newid();
369 etype = ETHERTYPE_IPV6;
370 break;
371#endif
372#ifdef NETATALK
373 case AF_APPLETALK:
374 etype = ETHERTYPE_ATALK;
375 break;
376#endif
377 default:
378 _IF_DROP(&ifp->if_snd);
379 m_freem(m);
380 error = EAFNOSUPPORT;
381 goto end;
382 }
383 M_PREPEND(m, sizeof(struct greip), M_DONTWAIT);
384 } else {
385 _IF_DROP(&ifp->if_snd);
386 m_freem(m);
387 error = EINVAL;
388 goto end;
389 }
390
391 if (m == NULL) { /* mbuf allocation failed */
392 _IF_DROP(&ifp->if_snd);
393 error = ENOBUFS;
394 goto end;
395 }
396
397 gh = mtod(m, struct greip *);
398 if (sc->g_proto == IPPROTO_GRE) {
399 /* we don't have any GRE flags for now */
400 memset((void *)gh, 0, sizeof(struct greip));
401 gh->gi_ptype = htons(etype);
402 }
403
404 gh->gi_pr = sc->g_proto;
405 if (sc->g_proto != IPPROTO_MOBILE) {
406 gh->gi_src = sc->g_src;
407 gh->gi_dst = sc->g_dst;
408 ((struct ip*)gh)->ip_v = IPPROTO_IPV4;
409 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2;
410 ((struct ip*)gh)->ip_ttl = GRE_TTL;
411 ((struct ip*)gh)->ip_tos = ip_tos;
412 ((struct ip*)gh)->ip_id = ip_id;
413 gh->gi_len = m->m_pkthdr.len;
414 }
415
416 ifp->if_opackets++;
417 ifp->if_obytes += m->m_pkthdr.len;
418 /*
419 * Send it off and with IP_FORWARD flag to prevent it from
420 * overwriting the ip_id again. ip_id is already set to the
421 * ip_id of the encapsulated packet.
422 */
423 error = ip_output(m, NULL, &sc->route, IP_FORWARDING,
424 (struct ip_moptions *)NULL, (struct inpcb *)NULL);
425 end:
426 sc->called = 0;
427 if (error)
428 ifp->if_oerrors++;
429 return (error);
430}
431
432static int
433gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
434{
435 struct ifreq *ifr = (struct ifreq *)data;
436 struct if_laddrreq *lifr = (struct if_laddrreq *)data;
437 struct in_aliasreq *aifr = (struct in_aliasreq *)data;
438 struct gre_softc *sc = ifp->if_softc;
439 int s;
440 struct sockaddr_in si;
441 struct sockaddr *sa = NULL;
442 int error;
443 struct sockaddr_in sp, sm, dp, dm;
444
445 error = 0;
446
447 s = splnet();
448 switch (cmd) {
449 case SIOCSIFADDR:
450 ifp->if_flags |= IFF_UP;
451 break;
452 case SIOCSIFDSTADDR:
453 break;
454 case SIOCSIFFLAGS:
455 if ((error = suser(curthread)) != 0)
456 break;
457 if ((ifr->ifr_flags & IFF_LINK0) != 0)
458 sc->g_proto = IPPROTO_GRE;
459 else
460 sc->g_proto = IPPROTO_MOBILE;
461 if ((ifr->ifr_flags & IFF_LINK2) != 0)
462 sc->wccp_ver = WCCP_V2;
463 else
464 sc->wccp_ver = WCCP_V1;
465 goto recompute;
466 case SIOCSIFMTU:
467 if ((error = suser(curthread)) != 0)
468 break;
469 if (ifr->ifr_mtu < 576) {
470 error = EINVAL;
471 break;
472 }
473 ifp->if_mtu = ifr->ifr_mtu;
474 break;
475 case SIOCGIFMTU:
476 ifr->ifr_mtu = GRE2IFP(sc)->if_mtu;
477 break;
478 case SIOCADDMULTI:
479 case SIOCDELMULTI:
480 if ((error = suser(curthread)) != 0)
481 break;
482 if (ifr == 0) {
483 error = EAFNOSUPPORT;
484 break;
485 }
486 switch (ifr->ifr_addr.sa_family) {
487#ifdef INET
488 case AF_INET:
489 break;
490#endif
491#ifdef INET6
492 case AF_INET6:
493 break;
494#endif
495 default:
496 error = EAFNOSUPPORT;
497 break;
498 }
499 break;
500 case GRESPROTO:
501 if ((error = suser(curthread)) != 0)
502 break;
503 sc->g_proto = ifr->ifr_flags;
504 switch (sc->g_proto) {
505 case IPPROTO_GRE:
506 ifp->if_flags |= IFF_LINK0;
507 break;
508 case IPPROTO_MOBILE:
509 ifp->if_flags &= ~IFF_LINK0;
510 break;
511 default:
512 error = EPROTONOSUPPORT;
513 break;
514 }
515 goto recompute;
516 case GREGPROTO:
517 ifr->ifr_flags = sc->g_proto;
518 break;
519 case GRESADDRS:
520 case GRESADDRD:
521 if ((error = suser(curthread)) != 0)
522 break;
523 /*
524 * set tunnel endpoints, compute a less specific route
525 * to the remote end and mark if as up
526 */
527 sa = &ifr->ifr_addr;
528 if (cmd == GRESADDRS)
529 sc->g_src = (satosin(sa))->sin_addr;
530 if (cmd == GRESADDRD)
531 sc->g_dst = (satosin(sa))->sin_addr;
532 recompute:
533#ifdef INET
534 if (sc->encap != NULL) {
535 encap_detach(sc->encap);
536 sc->encap = NULL;
537 }
538#endif
539 if ((sc->g_src.s_addr != INADDR_ANY) &&
540 (sc->g_dst.s_addr != INADDR_ANY)) {
541 bzero(&sp, sizeof(sp));
542 bzero(&sm, sizeof(sm));
543 bzero(&dp, sizeof(dp));
544 bzero(&dm, sizeof(dm));
545 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len =
546 sizeof(struct sockaddr_in);
547 sp.sin_family = sm.sin_family = dp.sin_family =
548 dm.sin_family = AF_INET;
549 sp.sin_addr = sc->g_src;
550 dp.sin_addr = sc->g_dst;
551 sm.sin_addr.s_addr = dm.sin_addr.s_addr =
552 INADDR_BROADCAST;
553#ifdef INET
554 sc->encap = encap_attach(AF_INET, sc->g_proto,
555 sintosa(&sp), sintosa(&sm), sintosa(&dp),
556 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ?
557 &in_gre_protosw : &in_mobile_protosw, sc);
558 if (sc->encap == NULL)
559 printf("%s: unable to attach encap\n",
560 if_name(GRE2IFP(sc)));
561#endif
562 if (sc->route.ro_rt != 0) /* free old route */
563 RTFREE(sc->route.ro_rt);
564 if (gre_compute_route(sc) == 0)
565 ifp->if_drv_flags |= IFF_DRV_RUNNING;
566 else
567 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
568 }
569 break;
570 case GREGADDRS:
571 memset(&si, 0, sizeof(si));
572 si.sin_family = AF_INET;
573 si.sin_len = sizeof(struct sockaddr_in);
574 si.sin_addr.s_addr = sc->g_src.s_addr;
575 sa = sintosa(&si);
576 ifr->ifr_addr = *sa;
577 break;
578 case GREGADDRD:
579 memset(&si, 0, sizeof(si));
580 si.sin_family = AF_INET;
581 si.sin_len = sizeof(struct sockaddr_in);
582 si.sin_addr.s_addr = sc->g_dst.s_addr;
583 sa = sintosa(&si);
584 ifr->ifr_addr = *sa;
585 break;
586 case SIOCSIFPHYADDR:
587 if ((error = suser(curthread)) != 0)
588 break;
589 if (aifr->ifra_addr.sin_family != AF_INET ||
590 aifr->ifra_dstaddr.sin_family != AF_INET) {
591 error = EAFNOSUPPORT;
592 break;
593 }
594 if (aifr->ifra_addr.sin_len != sizeof(si) ||
595 aifr->ifra_dstaddr.sin_len != sizeof(si)) {
596 error = EINVAL;
597 break;
598 }
599 sc->g_src = aifr->ifra_addr.sin_addr;
600 sc->g_dst = aifr->ifra_dstaddr.sin_addr;
601 goto recompute;
602 case SIOCSLIFPHYADDR:
603 if ((error = suser(curthread)) != 0)
604 break;
605 if (lifr->addr.ss_family != AF_INET ||
606 lifr->dstaddr.ss_family != AF_INET) {
607 error = EAFNOSUPPORT;
608 break;
609 }
610 if (lifr->addr.ss_len != sizeof(si) ||
611 lifr->dstaddr.ss_len != sizeof(si)) {
612 error = EINVAL;
613 break;
614 }
615 sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr;
616 sc->g_dst =
617 (satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr;
618 goto recompute;
619 case SIOCDIFPHYADDR:
620 if ((error = suser(curthread)) != 0)
621 break;
622 sc->g_src.s_addr = INADDR_ANY;
623 sc->g_dst.s_addr = INADDR_ANY;
624 goto recompute;
625 case SIOCGLIFPHYADDR:
626 if (sc->g_src.s_addr == INADDR_ANY ||
627 sc->g_dst.s_addr == INADDR_ANY) {
628 error = EADDRNOTAVAIL;
629 break;
630 }
631 memset(&si, 0, sizeof(si));
632 si.sin_family = AF_INET;
633 si.sin_len = sizeof(struct sockaddr_in);
634 si.sin_addr.s_addr = sc->g_src.s_addr;
635 memcpy(&lifr->addr, &si, sizeof(si));
636 si.sin_addr.s_addr = sc->g_dst.s_addr;
637 memcpy(&lifr->dstaddr, &si, sizeof(si));
638 break;
639 case SIOCGIFPSRCADDR:
640#ifdef INET6
641 case SIOCGIFPSRCADDR_IN6:
642#endif
643 if (sc->g_src.s_addr == INADDR_ANY) {
644 error = EADDRNOTAVAIL;
645 break;
646 }
647 memset(&si, 0, sizeof(si));
648 si.sin_family = AF_INET;
649 si.sin_len = sizeof(struct sockaddr_in);
650 si.sin_addr.s_addr = sc->g_src.s_addr;
651 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
652 break;
653 case SIOCGIFPDSTADDR:
654#ifdef INET6
655 case SIOCGIFPDSTADDR_IN6:
656#endif
657 if (sc->g_dst.s_addr == INADDR_ANY) {
658 error = EADDRNOTAVAIL;
659 break;
660 }
661 memset(&si, 0, sizeof(si));
662 si.sin_family = AF_INET;
663 si.sin_len = sizeof(struct sockaddr_in);
664 si.sin_addr.s_addr = sc->g_dst.s_addr;
665 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
666 break;
667 default:
668 error = EINVAL;
669 break;
670 }
671
672 splx(s);
673 return (error);
674}
675
676/*
677 * computes a route to our destination that is not the one
678 * which would be taken by ip_output(), as this one will loop back to
679 * us. If the interface is p2p as a--->b, then a routing entry exists
680 * If we now send a packet to b (e.g. ping b), this will come down here
681 * gets src=a, dst=b tacked on and would from ip_output() sent back to
682 * if_gre.
683 * Goal here is to compute a route to b that is less specific than
684 * a-->b. We know that this one exists as in normal operation we have
685 * at least a default route which matches.
686 */
687static int
688gre_compute_route(struct gre_softc *sc)
689{
690 struct route *ro;
691 u_int32_t a, b, c;
692
693 ro = &sc->route;
694
695 memset(ro, 0, sizeof(struct route));
696 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
697 ro->ro_dst.sa_family = AF_INET;
698 ro->ro_dst.sa_len = sizeof(ro->ro_dst);
699
700 /*
701 * toggle last bit, so our interface is not found, but a less
702 * specific route. I'd rather like to specify a shorter mask,
703 * but this is not possible. Should work though. XXX
704 * there is a simpler way ...
705 */
706 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) {
707 a = ntohl(sc->g_dst.s_addr);
708 b = a & 0x01;
709 c = a & 0xfffffffe;
710 b = b ^ 0x01;
711 a = b | c;
712 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr
713 = htonl(a);
714 }
715
716#ifdef DIAGNOSTIC
717 printf("%s: searching for a route to %s", if_name(GRE2IFP(sc)),
718 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr));
719#endif
720
721 rtalloc(ro);
722
723 /*
724 * check if this returned a route at all and this route is no
725 * recursion to ourself
726 */
727 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) {
728#ifdef DIAGNOSTIC
729 if (ro->ro_rt == NULL)
730 printf(" - no route found!\n");
731 else
732 printf(" - route loops back to ourself!\n");
733#endif
734 return EADDRNOTAVAIL;
735 }
736
737 /*
738 * now change it back - else ip_output will just drop
739 * the route and search one to this interface ...
740 */
741 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0)
742 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
743
744#ifdef DIAGNOSTIC
745 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp),
746 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr));
747 printf("\n");
748#endif
749
750 return 0;
751}
752
753/*
754 * do a checksum of a buffer - much like in_cksum, which operates on
755 * mbufs.
756 */
757u_int16_t
758gre_in_cksum(u_int16_t *p, u_int len)
759{
760 u_int32_t sum = 0;
761 int nwords = len >> 1;
762
763 while (nwords-- != 0)
764 sum += *p++;
765
766 if (len & 1) {
767 union {
768 u_short w;
769 u_char c[2];
770 } u;
771 u.c[0] = *(u_char *)p;
772 u.c[1] = 0;
773 sum += u.w;
774 }
775
776 /* end-around-carry */
777 sum = (sum >> 16) + (sum & 0xffff);
778 sum += (sum >> 16);
779 return (~sum);
780}
781
782static int
783gremodevent(module_t mod, int type, void *data)
784{
785
786 switch (type) {
787 case MOD_LOAD:
788 greattach();
789 break;
790 case MOD_UNLOAD:
791 if_clone_detach(&gre_cloner);
792 mtx_destroy(&gre_mtx);
793 break;
794 default:
795 return EOPNOTSUPP;
796 }
797 return 0;
798}
799
800static moduledata_t gre_mod = {
801 "if_gre",
802 gremodevent,
803 0
804};
805
806DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
807MODULE_VERSION(if_gre, 1);
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