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 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the NetBSD
22 * Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 * contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40/*
41 * Encapsulate L3 protocols into IP
42 * See RFC 1701 and 1702 for more details.
43 * If_gre is compatible with Cisco GRE tunnels, so you can
44 * have a NetBSD box as the other end of a tunnel interface of a Cisco
45 * router. See gre(4) for more details.
46 * Also supported: IP in IP encaps (proto 55) as of RFC 2004
47 */
48
49#include "opt_atalk.h"
50#include "opt_inet.h"
| 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 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the NetBSD
22 * Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 * contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40/*
41 * Encapsulate L3 protocols into IP
42 * See RFC 1701 and 1702 for more details.
43 * If_gre is compatible with Cisco GRE tunnels, so you can
44 * have a NetBSD box as the other end of a tunnel interface of a Cisco
45 * router. See gre(4) for more details.
46 * Also supported: IP in IP encaps (proto 55) as of RFC 2004
47 */
48
49#include "opt_atalk.h"
50#include "opt_inet.h"
|
51
52#include <sys/param.h>
53#include <sys/kernel.h>
54#include <sys/malloc.h>
55#include <sys/mbuf.h>
56#include <sys/protosw.h>
57#include <sys/socket.h>
58#include <sys/sockio.h>
59#include <sys/sysctl.h>
60#include <sys/systm.h>
61
62#include <net/ethernet.h>
63#include <net/if.h>
64#include <net/if_types.h>
65#include <net/route.h>
66
67#ifdef INET
68#include <netinet/in.h>
69#include <netinet/in_systm.h>
70#include <netinet/in_var.h>
71#include <netinet/ip.h>
72#include <netinet/ip_gre.h>
73#include <netinet/ip_var.h>
74#include <netinet/ip_encap.h>
75#else
76#error "Huh? if_gre without inet?"
77#endif
78
79#include <net/bpf.h>
80
81#include <net/net_osdep.h>
82#include <net/if_gre.h>
83
84/*
85 * It is not easy to calculate the right value for a GRE MTU.
86 * We leave this task to the admin and use the same default that
87 * other vendors use.
88 */
89#define GREMTU 1476
90
91#define GRENAME "gre"
92
93static MALLOC_DEFINE(M_GRE, GRENAME, "Generic Routing Encapsulation");
94
95struct gre_softc_head gre_softc_list;
96
97static int gre_clone_create(struct if_clone *, int);
98static void gre_clone_destroy(struct ifnet *);
99static int gre_ioctl(struct ifnet *, u_long, caddr_t);
100static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *,
101 struct rtentry *rt);
102
103static struct if_clone gre_cloner =
104 IF_CLONE_INITIALIZER("gre", gre_clone_create, gre_clone_destroy, 0, IF_MAXUNIT);
105
106static int gre_compute_route(struct gre_softc *sc);
107
108static void greattach(void);
109
110#ifdef INET
111extern struct domain inetdomain;
112static const struct protosw in_gre_protosw =
113{ SOCK_RAW, &inetdomain, IPPROTO_GRE, PR_ATOMIC|PR_ADDR,
114 (pr_input_t*)gre_input, (pr_output_t*)rip_output, rip_ctlinput, rip_ctloutput,
115 0,
116 0, 0, 0, 0,
117 &rip_usrreqs
118};
119static const struct protosw in_mobile_protosw =
120{ SOCK_RAW, &inetdomain, IPPROTO_MOBILE, PR_ATOMIC|PR_ADDR,
121 (pr_input_t*)gre_mobile_input, (pr_output_t*)rip_output, rip_ctlinput, rip_ctloutput,
122 0,
123 0, 0, 0, 0,
124 &rip_usrreqs
125};
126#endif
127
128SYSCTL_DECL(_net_link);
129SYSCTL_NODE(_net_link, IFT_OTHER, gre, CTLFLAG_RW, 0,
130 "Generic Routing Encapsulation");
131#ifndef MAX_GRE_NEST
132/*
133 * This macro controls the default upper limitation on nesting of gre tunnels.
134 * Since, setting a large value to this macro with a careless configuration
135 * may introduce system crash, we don't allow any nestings by default.
136 * If you need to configure nested gre tunnels, you can define this macro
137 * in your kernel configuration file. However, if you do so, please be
138 * careful to configure the tunnels so that it won't make a loop.
139 */
140#define MAX_GRE_NEST 1
141#endif
142static int max_gre_nesting = MAX_GRE_NEST;
143SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW,
144 &max_gre_nesting, 0, "Max nested tunnels");
145
146/* ARGSUSED */
147static void
148greattach(void)
149{
150
151 LIST_INIT(&gre_softc_list);
152 if_clone_attach(&gre_cloner);
153}
154
155static int
156gre_clone_create(ifc, unit)
157 struct if_clone *ifc;
158 int unit;
159{
160 struct gre_softc *sc;
161
162 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK);
163 memset(sc, 0, sizeof(struct gre_softc));
164
165 if_initname(&sc->sc_if, ifc->ifc_name, unit);
166 sc->sc_if.if_softc = sc;
167 sc->sc_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
168 sc->sc_if.if_type = IFT_OTHER;
169 sc->sc_if.if_addrlen = 0;
170 sc->sc_if.if_hdrlen = 24; /* IP + GRE */
171 sc->sc_if.if_mtu = GREMTU;
172 sc->sc_if.if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
173 sc->sc_if.if_output = gre_output;
174 sc->sc_if.if_ioctl = gre_ioctl;
175 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY;
176 sc->g_proto = IPPROTO_GRE;
177 sc->sc_if.if_flags |= IFF_LINK0;
178 sc->encap = NULL;
179 sc->called = 0;
180 if_attach(&sc->sc_if);
181 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int32_t));
182 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list);
183 return (0);
184}
185
186static void
187gre_clone_destroy(ifp)
188 struct ifnet *ifp;
189{
190 struct gre_softc *sc = ifp->if_softc;
191
192#ifdef INET
193 if (sc->encap != NULL)
194 encap_detach(sc->encap);
195#endif
196 LIST_REMOVE(sc, sc_list);
197 bpfdetach(ifp);
198 if_detach(ifp);
199 free(sc, M_GRE);
200}
201
202/*
203 * The output routine. Takes a packet and encapsulates it in the protocol
204 * given by sc->g_proto. See also RFC 1701 and RFC 2004
205 */
206static int
207gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
208 struct rtentry *rt)
209{
210 int error = 0;
211 struct gre_softc *sc = ifp->if_softc;
212 struct greip *gh;
213 struct ip *ip;
214 u_char osrc;
215 u_short etype = 0;
216 struct mobile_h mob_h;
217
218 /*
219 * gre may cause infinite recursion calls when misconfigured.
220 * We'll prevent this by introducing upper limit.
221 */
222 if (++(sc->called) > max_gre_nesting) {
223 printf("%s: gre_output: recursively called too many "
224 "times(%d)\n", if_name(&sc->sc_if), sc->called);
225 m_freem(m);
226 error = EIO; /* is there better errno? */
227 goto end;
228 }
229
230 if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) == 0 ||
231 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) {
232 m_freem(m);
233 error = ENETDOWN;
234 goto end;
235 }
236
237 gh = NULL;
238 ip = NULL;
239 osrc = 0;
240
241 if (ifp->if_bpf) {
242 /* see comment of other if_foo.c files */
243 struct mbuf m0;
244 u_int32_t af = dst->sa_family;
245
246 m0.m_next = m;
247 m0.m_len = 4;
248 m0.m_data = (char *)⁡
249
250 BPF_MTAP(ifp, &m0);
251 }
252
253 m->m_flags &= ~(M_BCAST|M_MCAST);
254
255 if (sc->g_proto == IPPROTO_MOBILE) {
256 if (dst->sa_family == AF_INET) {
257 struct mbuf *m0;
258 int msiz;
259
260 ip = mtod(m, struct ip *);
261
262 /*
263 * RFC2004 specifies that fragmented diagrams shouldn't
264 * be encapsulated.
265 */
266 if ((ip->ip_off & IP_MF) != 0) {
267 _IF_DROP(&ifp->if_snd);
268 m_freem(m);
269 error = EINVAL; /* is there better errno? */
270 goto end;
271 }
272 memset(&mob_h, 0, MOB_H_SIZ_L);
273 mob_h.proto = (ip->ip_p) << 8;
274 mob_h.odst = ip->ip_dst.s_addr;
275 ip->ip_dst.s_addr = sc->g_dst.s_addr;
276
277 /*
278 * If the packet comes from our host, we only change
279 * the destination address in the IP header.
280 * Else we also need to save and change the source
281 */
282 if (in_hosteq(ip->ip_src, sc->g_src)) {
283 msiz = MOB_H_SIZ_S;
284 } else {
285 mob_h.proto |= MOB_H_SBIT;
286 mob_h.osrc = ip->ip_src.s_addr;
287 ip->ip_src.s_addr = sc->g_src.s_addr;
288 msiz = MOB_H_SIZ_L;
289 }
290 mob_h.proto = htons(mob_h.proto);
291 mob_h.hcrc = gre_in_cksum((u_short *)&mob_h, msiz);
292
293 if ((m->m_data - msiz) < m->m_pktdat) {
294 /* need new mbuf */
295 MGETHDR(m0, M_DONTWAIT, MT_HEADER);
296 if (m0 == NULL) {
297 _IF_DROP(&ifp->if_snd);
298 m_freem(m);
299 error = ENOBUFS;
300 goto end;
301 }
302 m0->m_next = m;
303 m->m_data += sizeof(struct ip);
304 m->m_len -= sizeof(struct ip);
305 m0->m_pkthdr.len = m->m_pkthdr.len + msiz;
306 m0->m_len = msiz + sizeof(struct ip);
307 m0->m_data += max_linkhdr;
308 memcpy(mtod(m0, caddr_t), (caddr_t)ip,
309 sizeof(struct ip));
310 m = m0;
311 } else { /* we have some space left in the old one */
312 m->m_data -= msiz;
313 m->m_len += msiz;
314 m->m_pkthdr.len += msiz;
315 bcopy(ip, mtod(m, caddr_t),
316 sizeof(struct ip));
317 }
318 ip = mtod(m, struct ip *);
319 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz);
320 ip->ip_len = ntohs(ip->ip_len) + msiz;
321 } else { /* AF_INET */
322 _IF_DROP(&ifp->if_snd);
323 m_freem(m);
324 error = EINVAL;
325 goto end;
326 }
327 } else if (sc->g_proto == IPPROTO_GRE) {
328 switch (dst->sa_family) {
329 case AF_INET:
330 ip = mtod(m, struct ip *);
331 etype = ETHERTYPE_IP;
332 break;
333#ifdef NETATALK
334 case AF_APPLETALK:
335 etype = ETHERTYPE_ATALK;
336 break;
337#endif
338 default:
339 _IF_DROP(&ifp->if_snd);
340 m_freem(m);
341 error = EAFNOSUPPORT;
342 goto end;
343 }
344 M_PREPEND(m, sizeof(struct greip), M_DONTWAIT);
345 } else {
346 _IF_DROP(&ifp->if_snd);
347 m_freem(m);
348 error = EINVAL;
349 goto end;
350 }
351
352 if (m == NULL) { /* impossible */
353 _IF_DROP(&ifp->if_snd);
354 error = ENOBUFS;
355 goto end;
356 }
357
358 gh = mtod(m, struct greip *);
359 if (sc->g_proto == IPPROTO_GRE) {
360 /* we don't have any GRE flags for now */
361
362 memset((void *)&gh->gi_g, 0, sizeof(struct gre_h));
363 gh->gi_ptype = htons(etype);
364 }
365
366 gh->gi_pr = sc->g_proto;
367 if (sc->g_proto != IPPROTO_MOBILE) {
368 gh->gi_src = sc->g_src;
369 gh->gi_dst = sc->g_dst;
370 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2;
371 ((struct ip*)gh)->ip_ttl = GRE_TTL;
372 ((struct ip*)gh)->ip_tos = ip->ip_tos;
373 ((struct ip*)gh)->ip_id = ip->ip_id;
374 gh->gi_len = m->m_pkthdr.len;
375 }
376
377 ifp->if_opackets++;
378 ifp->if_obytes += m->m_pkthdr.len;
379 /* send it off */
380 error = ip_output(m, NULL, &sc->route, 0, NULL, NULL);
381 end:
382 sc->called = 0;
383 if (error)
384 ifp->if_oerrors++;
385 return (error);
386}
387
388static int
389gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
390{
391 struct ifreq *ifr = (struct ifreq *)data;
392 struct if_laddrreq *lifr = (struct if_laddrreq *)data;
393 struct in_aliasreq *aifr = (struct in_aliasreq *)data;
394 struct gre_softc *sc = ifp->if_softc;
395 int s;
396 struct sockaddr_in si;
397 struct sockaddr *sa = NULL;
398 int error;
399 struct sockaddr_in sp, sm, dp, dm;
400
401 error = 0;
402
403 s = splnet();
404 switch (cmd) {
405 case SIOCSIFADDR:
406 ifp->if_flags |= IFF_UP;
407 break;
408 case SIOCSIFDSTADDR:
409 break;
410 case SIOCSIFFLAGS:
411 if ((error = suser(curthread)) != 0)
412 break;
413 if ((ifr->ifr_flags & IFF_LINK0) != 0)
414 sc->g_proto = IPPROTO_GRE;
415 else
416 sc->g_proto = IPPROTO_MOBILE;
417 goto recompute;
418 case SIOCSIFMTU:
419 if ((error = suser(curthread)) != 0)
420 break;
421 if (ifr->ifr_mtu < 576) {
422 error = EINVAL;
423 break;
424 }
425 ifp->if_mtu = ifr->ifr_mtu;
426 break;
427 case SIOCGIFMTU:
428 ifr->ifr_mtu = sc->sc_if.if_mtu;
429 break;
430 case SIOCADDMULTI:
431 case SIOCDELMULTI:
432 if ((error = suser(curthread)) != 0)
433 break;
434 if (ifr == 0) {
435 error = EAFNOSUPPORT;
436 break;
437 }
438 switch (ifr->ifr_addr.sa_family) {
439#ifdef INET
440 case AF_INET:
441 break;
442#endif
443 default:
444 error = EAFNOSUPPORT;
445 break;
446 }
447 break;
448 case GRESPROTO:
449 if ((error = suser(curthread)) != 0)
450 break;
451 sc->g_proto = ifr->ifr_flags;
452 switch (sc->g_proto) {
453 case IPPROTO_GRE:
454 ifp->if_flags |= IFF_LINK0;
455 break;
456 case IPPROTO_MOBILE:
457 ifp->if_flags &= ~IFF_LINK0;
458 break;
459 default:
460 error = EPROTONOSUPPORT;
461 break;
462 }
463 goto recompute;
464 case GREGPROTO:
465 ifr->ifr_flags = sc->g_proto;
466 break;
467 case GRESADDRS:
468 case GRESADDRD:
469 if ((error = suser(curthread)) != 0)
470 break;
471 /*
472 * set tunnel endpoints, compute a less specific route
473 * to the remote end and mark if as up
474 */
475 sa = &ifr->ifr_addr;
476 if (cmd == GRESADDRS)
477 sc->g_src = (satosin(sa))->sin_addr;
478 if (cmd == GRESADDRD)
479 sc->g_dst = (satosin(sa))->sin_addr;
480 recompute:
481#ifdef INET
482 if (sc->encap != NULL) {
483 encap_detach(sc->encap);
484 sc->encap = NULL;
485 }
486#endif
487 if ((sc->g_src.s_addr != INADDR_ANY) &&
488 (sc->g_dst.s_addr != INADDR_ANY)) {
489 bzero(&sp, sizeof(sp));
490 bzero(&sm, sizeof(sm));
491 bzero(&dp, sizeof(dp));
492 bzero(&dm, sizeof(dm));
493 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len =
494 sizeof(struct sockaddr_in);
495 sp.sin_family = sm.sin_family = dp.sin_family =
496 dm.sin_family = AF_INET;
497 sp.sin_addr = sc->g_src;
498 dp.sin_addr = sc->g_dst;
499 sm.sin_addr.s_addr = dm.sin_addr.s_addr =
500 INADDR_BROADCAST;
501#ifdef INET
502 sc->encap = encap_attach(AF_INET, sc->g_proto,
503 sintosa(&sp), sintosa(&sm), sintosa(&dp),
504 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ?
505 &in_gre_protosw : &in_mobile_protosw, sc);
506 if (sc->encap == NULL)
507 printf("%s: unable to attach encap\n",
508 if_name(&sc->sc_if));
509#endif
510 if (sc->route.ro_rt != 0) /* free old route */
511 RTFREE(sc->route.ro_rt);
512 if (gre_compute_route(sc) == 0)
513 ifp->if_flags |= IFF_RUNNING;
514 else
515 ifp->if_flags &= ~IFF_RUNNING;
516 }
517 break;
518 case GREGADDRS:
519 memset(&si, 0, sizeof(si));
520 si.sin_family = AF_INET;
521 si.sin_len = sizeof(struct sockaddr_in);
522 si.sin_addr.s_addr = sc->g_src.s_addr;
523 sa = sintosa(&si);
524 ifr->ifr_addr = *sa;
525 break;
526 case GREGADDRD:
527 memset(&si, 0, sizeof(si));
528 si.sin_family = AF_INET;
529 si.sin_len = sizeof(struct sockaddr_in);
530 si.sin_addr.s_addr = sc->g_dst.s_addr;
531 sa = sintosa(&si);
532 ifr->ifr_addr = *sa;
533 break;
534 case SIOCSIFPHYADDR:
535 if ((error = suser(curthread)) != 0)
536 break;
537 if (aifr->ifra_addr.sin_family != AF_INET ||
538 aifr->ifra_dstaddr.sin_family != AF_INET) {
539 error = EAFNOSUPPORT;
540 break;
541 }
542 if (aifr->ifra_addr.sin_len != sizeof(si) ||
543 aifr->ifra_dstaddr.sin_len != sizeof(si)) {
544 error = EINVAL;
545 break;
546 }
547 sc->g_src = aifr->ifra_addr.sin_addr;
548 sc->g_dst = aifr->ifra_dstaddr.sin_addr;
549 goto recompute;
550 case SIOCSLIFPHYADDR:
551 if ((error = suser(curthread)) != 0)
552 break;
553 if (lifr->addr.ss_family != AF_INET ||
554 lifr->dstaddr.ss_family != AF_INET) {
555 error = EAFNOSUPPORT;
556 break;
557 }
558 if (lifr->addr.ss_len != sizeof(si) ||
559 lifr->dstaddr.ss_len != sizeof(si)) {
560 error = EINVAL;
561 break;
562 }
563 sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr;
564 sc->g_dst =
565 (satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr;
566 goto recompute;
567 case SIOCDIFPHYADDR:
568 if ((error = suser(curthread)) != 0)
569 break;
570 sc->g_src.s_addr = INADDR_ANY;
571 sc->g_dst.s_addr = INADDR_ANY;
572 goto recompute;
573 case SIOCGLIFPHYADDR:
574 if (sc->g_src.s_addr == INADDR_ANY ||
575 sc->g_dst.s_addr == INADDR_ANY) {
576 error = EADDRNOTAVAIL;
577 break;
578 }
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_src.s_addr;
583 memcpy(&lifr->addr, &si, sizeof(si));
584 si.sin_addr.s_addr = sc->g_dst.s_addr;
585 memcpy(&lifr->dstaddr, &si, sizeof(si));
586 break;
587 case SIOCGIFPSRCADDR:
| 52
53#include <sys/param.h>
54#include <sys/kernel.h>
55#include <sys/malloc.h>
56#include <sys/mbuf.h>
57#include <sys/protosw.h>
58#include <sys/socket.h>
59#include <sys/sockio.h>
60#include <sys/sysctl.h>
61#include <sys/systm.h>
62
63#include <net/ethernet.h>
64#include <net/if.h>
65#include <net/if_types.h>
66#include <net/route.h>
67
68#ifdef INET
69#include <netinet/in.h>
70#include <netinet/in_systm.h>
71#include <netinet/in_var.h>
72#include <netinet/ip.h>
73#include <netinet/ip_gre.h>
74#include <netinet/ip_var.h>
75#include <netinet/ip_encap.h>
76#else
77#error "Huh? if_gre without inet?"
78#endif
79
80#include <net/bpf.h>
81
82#include <net/net_osdep.h>
83#include <net/if_gre.h>
84
85/*
86 * It is not easy to calculate the right value for a GRE MTU.
87 * We leave this task to the admin and use the same default that
88 * other vendors use.
89 */
90#define GREMTU 1476
91
92#define GRENAME "gre"
93
94static MALLOC_DEFINE(M_GRE, GRENAME, "Generic Routing Encapsulation");
95
96struct gre_softc_head gre_softc_list;
97
98static int gre_clone_create(struct if_clone *, int);
99static void gre_clone_destroy(struct ifnet *);
100static int gre_ioctl(struct ifnet *, u_long, caddr_t);
101static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *,
102 struct rtentry *rt);
103
104static struct if_clone gre_cloner =
105 IF_CLONE_INITIALIZER("gre", gre_clone_create, gre_clone_destroy, 0, IF_MAXUNIT);
106
107static int gre_compute_route(struct gre_softc *sc);
108
109static void greattach(void);
110
111#ifdef INET
112extern struct domain inetdomain;
113static const struct protosw in_gre_protosw =
114{ SOCK_RAW, &inetdomain, IPPROTO_GRE, PR_ATOMIC|PR_ADDR,
115 (pr_input_t*)gre_input, (pr_output_t*)rip_output, rip_ctlinput, rip_ctloutput,
116 0,
117 0, 0, 0, 0,
118 &rip_usrreqs
119};
120static const struct protosw in_mobile_protosw =
121{ SOCK_RAW, &inetdomain, IPPROTO_MOBILE, PR_ATOMIC|PR_ADDR,
122 (pr_input_t*)gre_mobile_input, (pr_output_t*)rip_output, rip_ctlinput, rip_ctloutput,
123 0,
124 0, 0, 0, 0,
125 &rip_usrreqs
126};
127#endif
128
129SYSCTL_DECL(_net_link);
130SYSCTL_NODE(_net_link, IFT_OTHER, gre, CTLFLAG_RW, 0,
131 "Generic Routing Encapsulation");
132#ifndef MAX_GRE_NEST
133/*
134 * This macro controls the default upper limitation on nesting of gre tunnels.
135 * Since, setting a large value to this macro with a careless configuration
136 * may introduce system crash, we don't allow any nestings by default.
137 * If you need to configure nested gre tunnels, you can define this macro
138 * in your kernel configuration file. However, if you do so, please be
139 * careful to configure the tunnels so that it won't make a loop.
140 */
141#define MAX_GRE_NEST 1
142#endif
143static int max_gre_nesting = MAX_GRE_NEST;
144SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW,
145 &max_gre_nesting, 0, "Max nested tunnels");
146
147/* ARGSUSED */
148static void
149greattach(void)
150{
151
152 LIST_INIT(&gre_softc_list);
153 if_clone_attach(&gre_cloner);
154}
155
156static int
157gre_clone_create(ifc, unit)
158 struct if_clone *ifc;
159 int unit;
160{
161 struct gre_softc *sc;
162
163 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK);
164 memset(sc, 0, sizeof(struct gre_softc));
165
166 if_initname(&sc->sc_if, ifc->ifc_name, unit);
167 sc->sc_if.if_softc = sc;
168 sc->sc_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
169 sc->sc_if.if_type = IFT_OTHER;
170 sc->sc_if.if_addrlen = 0;
171 sc->sc_if.if_hdrlen = 24; /* IP + GRE */
172 sc->sc_if.if_mtu = GREMTU;
173 sc->sc_if.if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
174 sc->sc_if.if_output = gre_output;
175 sc->sc_if.if_ioctl = gre_ioctl;
176 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY;
177 sc->g_proto = IPPROTO_GRE;
178 sc->sc_if.if_flags |= IFF_LINK0;
179 sc->encap = NULL;
180 sc->called = 0;
181 if_attach(&sc->sc_if);
182 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int32_t));
183 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list);
184 return (0);
185}
186
187static void
188gre_clone_destroy(ifp)
189 struct ifnet *ifp;
190{
191 struct gre_softc *sc = ifp->if_softc;
192
193#ifdef INET
194 if (sc->encap != NULL)
195 encap_detach(sc->encap);
196#endif
197 LIST_REMOVE(sc, sc_list);
198 bpfdetach(ifp);
199 if_detach(ifp);
200 free(sc, M_GRE);
201}
202
203/*
204 * The output routine. Takes a packet and encapsulates it in the protocol
205 * given by sc->g_proto. See also RFC 1701 and RFC 2004
206 */
207static int
208gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
209 struct rtentry *rt)
210{
211 int error = 0;
212 struct gre_softc *sc = ifp->if_softc;
213 struct greip *gh;
214 struct ip *ip;
215 u_char osrc;
216 u_short etype = 0;
217 struct mobile_h mob_h;
218
219 /*
220 * gre may cause infinite recursion calls when misconfigured.
221 * We'll prevent this by introducing upper limit.
222 */
223 if (++(sc->called) > max_gre_nesting) {
224 printf("%s: gre_output: recursively called too many "
225 "times(%d)\n", if_name(&sc->sc_if), sc->called);
226 m_freem(m);
227 error = EIO; /* is there better errno? */
228 goto end;
229 }
230
231 if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) == 0 ||
232 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) {
233 m_freem(m);
234 error = ENETDOWN;
235 goto end;
236 }
237
238 gh = NULL;
239 ip = NULL;
240 osrc = 0;
241
242 if (ifp->if_bpf) {
243 /* see comment of other if_foo.c files */
244 struct mbuf m0;
245 u_int32_t af = dst->sa_family;
246
247 m0.m_next = m;
248 m0.m_len = 4;
249 m0.m_data = (char *)⁡
250
251 BPF_MTAP(ifp, &m0);
252 }
253
254 m->m_flags &= ~(M_BCAST|M_MCAST);
255
256 if (sc->g_proto == IPPROTO_MOBILE) {
257 if (dst->sa_family == AF_INET) {
258 struct mbuf *m0;
259 int msiz;
260
261 ip = mtod(m, struct ip *);
262
263 /*
264 * RFC2004 specifies that fragmented diagrams shouldn't
265 * be encapsulated.
266 */
267 if ((ip->ip_off & IP_MF) != 0) {
268 _IF_DROP(&ifp->if_snd);
269 m_freem(m);
270 error = EINVAL; /* is there better errno? */
271 goto end;
272 }
273 memset(&mob_h, 0, MOB_H_SIZ_L);
274 mob_h.proto = (ip->ip_p) << 8;
275 mob_h.odst = ip->ip_dst.s_addr;
276 ip->ip_dst.s_addr = sc->g_dst.s_addr;
277
278 /*
279 * If the packet comes from our host, we only change
280 * the destination address in the IP header.
281 * Else we also need to save and change the source
282 */
283 if (in_hosteq(ip->ip_src, sc->g_src)) {
284 msiz = MOB_H_SIZ_S;
285 } else {
286 mob_h.proto |= MOB_H_SBIT;
287 mob_h.osrc = ip->ip_src.s_addr;
288 ip->ip_src.s_addr = sc->g_src.s_addr;
289 msiz = MOB_H_SIZ_L;
290 }
291 mob_h.proto = htons(mob_h.proto);
292 mob_h.hcrc = gre_in_cksum((u_short *)&mob_h, msiz);
293
294 if ((m->m_data - msiz) < m->m_pktdat) {
295 /* need new mbuf */
296 MGETHDR(m0, M_DONTWAIT, MT_HEADER);
297 if (m0 == NULL) {
298 _IF_DROP(&ifp->if_snd);
299 m_freem(m);
300 error = ENOBUFS;
301 goto end;
302 }
303 m0->m_next = m;
304 m->m_data += sizeof(struct ip);
305 m->m_len -= sizeof(struct ip);
306 m0->m_pkthdr.len = m->m_pkthdr.len + msiz;
307 m0->m_len = msiz + sizeof(struct ip);
308 m0->m_data += max_linkhdr;
309 memcpy(mtod(m0, caddr_t), (caddr_t)ip,
310 sizeof(struct ip));
311 m = m0;
312 } else { /* we have some space left in the old one */
313 m->m_data -= msiz;
314 m->m_len += msiz;
315 m->m_pkthdr.len += msiz;
316 bcopy(ip, mtod(m, caddr_t),
317 sizeof(struct ip));
318 }
319 ip = mtod(m, struct ip *);
320 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz);
321 ip->ip_len = ntohs(ip->ip_len) + msiz;
322 } else { /* AF_INET */
323 _IF_DROP(&ifp->if_snd);
324 m_freem(m);
325 error = EINVAL;
326 goto end;
327 }
328 } else if (sc->g_proto == IPPROTO_GRE) {
329 switch (dst->sa_family) {
330 case AF_INET:
331 ip = mtod(m, struct ip *);
332 etype = ETHERTYPE_IP;
333 break;
334#ifdef NETATALK
335 case AF_APPLETALK:
336 etype = ETHERTYPE_ATALK;
337 break;
338#endif
339 default:
340 _IF_DROP(&ifp->if_snd);
341 m_freem(m);
342 error = EAFNOSUPPORT;
343 goto end;
344 }
345 M_PREPEND(m, sizeof(struct greip), M_DONTWAIT);
346 } else {
347 _IF_DROP(&ifp->if_snd);
348 m_freem(m);
349 error = EINVAL;
350 goto end;
351 }
352
353 if (m == NULL) { /* impossible */
354 _IF_DROP(&ifp->if_snd);
355 error = ENOBUFS;
356 goto end;
357 }
358
359 gh = mtod(m, struct greip *);
360 if (sc->g_proto == IPPROTO_GRE) {
361 /* we don't have any GRE flags for now */
362
363 memset((void *)&gh->gi_g, 0, sizeof(struct gre_h));
364 gh->gi_ptype = htons(etype);
365 }
366
367 gh->gi_pr = sc->g_proto;
368 if (sc->g_proto != IPPROTO_MOBILE) {
369 gh->gi_src = sc->g_src;
370 gh->gi_dst = sc->g_dst;
371 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2;
372 ((struct ip*)gh)->ip_ttl = GRE_TTL;
373 ((struct ip*)gh)->ip_tos = ip->ip_tos;
374 ((struct ip*)gh)->ip_id = ip->ip_id;
375 gh->gi_len = m->m_pkthdr.len;
376 }
377
378 ifp->if_opackets++;
379 ifp->if_obytes += m->m_pkthdr.len;
380 /* send it off */
381 error = ip_output(m, NULL, &sc->route, 0, NULL, NULL);
382 end:
383 sc->called = 0;
384 if (error)
385 ifp->if_oerrors++;
386 return (error);
387}
388
389static int
390gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
391{
392 struct ifreq *ifr = (struct ifreq *)data;
393 struct if_laddrreq *lifr = (struct if_laddrreq *)data;
394 struct in_aliasreq *aifr = (struct in_aliasreq *)data;
395 struct gre_softc *sc = ifp->if_softc;
396 int s;
397 struct sockaddr_in si;
398 struct sockaddr *sa = NULL;
399 int error;
400 struct sockaddr_in sp, sm, dp, dm;
401
402 error = 0;
403
404 s = splnet();
405 switch (cmd) {
406 case SIOCSIFADDR:
407 ifp->if_flags |= IFF_UP;
408 break;
409 case SIOCSIFDSTADDR:
410 break;
411 case SIOCSIFFLAGS:
412 if ((error = suser(curthread)) != 0)
413 break;
414 if ((ifr->ifr_flags & IFF_LINK0) != 0)
415 sc->g_proto = IPPROTO_GRE;
416 else
417 sc->g_proto = IPPROTO_MOBILE;
418 goto recompute;
419 case SIOCSIFMTU:
420 if ((error = suser(curthread)) != 0)
421 break;
422 if (ifr->ifr_mtu < 576) {
423 error = EINVAL;
424 break;
425 }
426 ifp->if_mtu = ifr->ifr_mtu;
427 break;
428 case SIOCGIFMTU:
429 ifr->ifr_mtu = sc->sc_if.if_mtu;
430 break;
431 case SIOCADDMULTI:
432 case SIOCDELMULTI:
433 if ((error = suser(curthread)) != 0)
434 break;
435 if (ifr == 0) {
436 error = EAFNOSUPPORT;
437 break;
438 }
439 switch (ifr->ifr_addr.sa_family) {
440#ifdef INET
441 case AF_INET:
442 break;
443#endif
444 default:
445 error = EAFNOSUPPORT;
446 break;
447 }
448 break;
449 case GRESPROTO:
450 if ((error = suser(curthread)) != 0)
451 break;
452 sc->g_proto = ifr->ifr_flags;
453 switch (sc->g_proto) {
454 case IPPROTO_GRE:
455 ifp->if_flags |= IFF_LINK0;
456 break;
457 case IPPROTO_MOBILE:
458 ifp->if_flags &= ~IFF_LINK0;
459 break;
460 default:
461 error = EPROTONOSUPPORT;
462 break;
463 }
464 goto recompute;
465 case GREGPROTO:
466 ifr->ifr_flags = sc->g_proto;
467 break;
468 case GRESADDRS:
469 case GRESADDRD:
470 if ((error = suser(curthread)) != 0)
471 break;
472 /*
473 * set tunnel endpoints, compute a less specific route
474 * to the remote end and mark if as up
475 */
476 sa = &ifr->ifr_addr;
477 if (cmd == GRESADDRS)
478 sc->g_src = (satosin(sa))->sin_addr;
479 if (cmd == GRESADDRD)
480 sc->g_dst = (satosin(sa))->sin_addr;
481 recompute:
482#ifdef INET
483 if (sc->encap != NULL) {
484 encap_detach(sc->encap);
485 sc->encap = NULL;
486 }
487#endif
488 if ((sc->g_src.s_addr != INADDR_ANY) &&
489 (sc->g_dst.s_addr != INADDR_ANY)) {
490 bzero(&sp, sizeof(sp));
491 bzero(&sm, sizeof(sm));
492 bzero(&dp, sizeof(dp));
493 bzero(&dm, sizeof(dm));
494 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len =
495 sizeof(struct sockaddr_in);
496 sp.sin_family = sm.sin_family = dp.sin_family =
497 dm.sin_family = AF_INET;
498 sp.sin_addr = sc->g_src;
499 dp.sin_addr = sc->g_dst;
500 sm.sin_addr.s_addr = dm.sin_addr.s_addr =
501 INADDR_BROADCAST;
502#ifdef INET
503 sc->encap = encap_attach(AF_INET, sc->g_proto,
504 sintosa(&sp), sintosa(&sm), sintosa(&dp),
505 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ?
506 &in_gre_protosw : &in_mobile_protosw, sc);
507 if (sc->encap == NULL)
508 printf("%s: unable to attach encap\n",
509 if_name(&sc->sc_if));
510#endif
511 if (sc->route.ro_rt != 0) /* free old route */
512 RTFREE(sc->route.ro_rt);
513 if (gre_compute_route(sc) == 0)
514 ifp->if_flags |= IFF_RUNNING;
515 else
516 ifp->if_flags &= ~IFF_RUNNING;
517 }
518 break;
519 case GREGADDRS:
520 memset(&si, 0, sizeof(si));
521 si.sin_family = AF_INET;
522 si.sin_len = sizeof(struct sockaddr_in);
523 si.sin_addr.s_addr = sc->g_src.s_addr;
524 sa = sintosa(&si);
525 ifr->ifr_addr = *sa;
526 break;
527 case GREGADDRD:
528 memset(&si, 0, sizeof(si));
529 si.sin_family = AF_INET;
530 si.sin_len = sizeof(struct sockaddr_in);
531 si.sin_addr.s_addr = sc->g_dst.s_addr;
532 sa = sintosa(&si);
533 ifr->ifr_addr = *sa;
534 break;
535 case SIOCSIFPHYADDR:
536 if ((error = suser(curthread)) != 0)
537 break;
538 if (aifr->ifra_addr.sin_family != AF_INET ||
539 aifr->ifra_dstaddr.sin_family != AF_INET) {
540 error = EAFNOSUPPORT;
541 break;
542 }
543 if (aifr->ifra_addr.sin_len != sizeof(si) ||
544 aifr->ifra_dstaddr.sin_len != sizeof(si)) {
545 error = EINVAL;
546 break;
547 }
548 sc->g_src = aifr->ifra_addr.sin_addr;
549 sc->g_dst = aifr->ifra_dstaddr.sin_addr;
550 goto recompute;
551 case SIOCSLIFPHYADDR:
552 if ((error = suser(curthread)) != 0)
553 break;
554 if (lifr->addr.ss_family != AF_INET ||
555 lifr->dstaddr.ss_family != AF_INET) {
556 error = EAFNOSUPPORT;
557 break;
558 }
559 if (lifr->addr.ss_len != sizeof(si) ||
560 lifr->dstaddr.ss_len != sizeof(si)) {
561 error = EINVAL;
562 break;
563 }
564 sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr;
565 sc->g_dst =
566 (satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr;
567 goto recompute;
568 case SIOCDIFPHYADDR:
569 if ((error = suser(curthread)) != 0)
570 break;
571 sc->g_src.s_addr = INADDR_ANY;
572 sc->g_dst.s_addr = INADDR_ANY;
573 goto recompute;
574 case SIOCGLIFPHYADDR:
575 if (sc->g_src.s_addr == INADDR_ANY ||
576 sc->g_dst.s_addr == INADDR_ANY) {
577 error = EADDRNOTAVAIL;
578 break;
579 }
580 memset(&si, 0, sizeof(si));
581 si.sin_family = AF_INET;
582 si.sin_len = sizeof(struct sockaddr_in);
583 si.sin_addr.s_addr = sc->g_src.s_addr;
584 memcpy(&lifr->addr, &si, sizeof(si));
585 si.sin_addr.s_addr = sc->g_dst.s_addr;
586 memcpy(&lifr->dstaddr, &si, sizeof(si));
587 break;
588 case SIOCGIFPSRCADDR:
|
599 if (sc->g_dst.s_addr == INADDR_ANY) {
600 error = EADDRNOTAVAIL;
601 break;
602 }
603 memset(&si, 0, sizeof(si));
604 si.sin_family = AF_INET;
605 si.sin_len = sizeof(struct sockaddr_in);
606 si.sin_addr.s_addr = sc->g_dst.s_addr;
607 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
608 break;
609 default:
610 error = EINVAL;
611 break;
612 }
613
614 splx(s);
615 return (error);
616}
617
618/*
619 * computes a route to our destination that is not the one
620 * which would be taken by ip_output(), as this one will loop back to
621 * us. If the interface is p2p as a--->b, then a routing entry exists
622 * If we now send a packet to b (e.g. ping b), this will come down here
623 * gets src=a, dst=b tacked on and would from ip_ouput() sent back to
624 * if_gre.
625 * Goal here is to compute a route to b that is less specific than
626 * a-->b. We know that this one exists as in normal operation we have
627 * at least a default route which matches.
628 */
629static int
630gre_compute_route(struct gre_softc *sc)
631{
632 struct route *ro;
633 u_int32_t a, b, c;
634
635 ro = &sc->route;
636
637 memset(ro, 0, sizeof(struct route));
638 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
639 ro->ro_dst.sa_family = AF_INET;
640 ro->ro_dst.sa_len = sizeof(ro->ro_dst);
641
642 /*
643 * toggle last bit, so our interface is not found, but a less
644 * specific route. I'd rather like to specify a shorter mask,
645 * but this is not possible. Should work though. XXX
646 * there is a simpler way ...
647 */
648 if ((sc->sc_if.if_flags & IFF_LINK1) == 0) {
649 a = ntohl(sc->g_dst.s_addr);
650 b = a & 0x01;
651 c = a & 0xfffffffe;
652 b = b ^ 0x01;
653 a = b | c;
654 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr
655 = htonl(a);
656 }
657
658#ifdef DIAGNOSTIC
659 printf("%s: searching a route to %s", if_name(&sc->sc_if),
660 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr));
661#endif
662
663 rtalloc(ro);
664
665 /*
666 * check if this returned a route at all and this route is no
667 * recursion to ourself
668 */
669 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) {
670#ifdef DIAGNOSTIC
671 if (ro->ro_rt == NULL)
672 printf(" - no route found!\n");
673 else
674 printf(" - route loops back to ourself!\n");
675#endif
676 return EADDRNOTAVAIL;
677 }
678
679 /*
680 * now change it back - else ip_output will just drop
681 * the route and search one to this interface ...
682 */
683 if ((sc->sc_if.if_flags & IFF_LINK1) == 0)
684 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
685
686#ifdef DIAGNOSTIC
687 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp),
688 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr));
689 printf("\n");
690#endif
691
692 return 0;
693}
694
695/*
696 * do a checksum of a buffer - much like in_cksum, which operates on
697 * mbufs.
698 */
699u_short
700gre_in_cksum(u_short *p, u_int len)
701{
702 u_int sum = 0;
703 int nwords = len >> 1;
704
705 while (nwords-- != 0)
706 sum += *p++;
707
708 if (len & 1) {
709 union {
710 u_short w;
711 u_char c[2];
712 } u;
713 u.c[0] = *(u_char *)p;
714 u.c[1] = 0;
715 sum += u.w;
716 }
717
718 /* end-around-carry */
719 sum = (sum >> 16) + (sum & 0xffff);
720 sum += (sum >> 16);
721 return (~sum);
722}
723
724static int
725gremodevent(module_t mod, int type, void *data)
726{
727
728 switch (type) {
729 case MOD_LOAD:
730 greattach();
731 break;
732 case MOD_UNLOAD:
733 if_clone_detach(&gre_cloner);
734
735 while (!LIST_EMPTY(&gre_softc_list))
736 gre_clone_destroy(&LIST_FIRST(&gre_softc_list)->sc_if);
737 break;
738 }
739 return 0;
740}
741
742static moduledata_t gre_mod = {
743 "if_gre",
744 gremodevent,
745 0
746};
747
748DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
749MODULE_VERSION(if_gre, 1);
| 606 if (sc->g_dst.s_addr == INADDR_ANY) {
607 error = EADDRNOTAVAIL;
608 break;
609 }
610 memset(&si, 0, sizeof(si));
611 si.sin_family = AF_INET;
612 si.sin_len = sizeof(struct sockaddr_in);
613 si.sin_addr.s_addr = sc->g_dst.s_addr;
614 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
615 break;
616 default:
617 error = EINVAL;
618 break;
619 }
620
621 splx(s);
622 return (error);
623}
624
625/*
626 * computes a route to our destination that is not the one
627 * which would be taken by ip_output(), as this one will loop back to
628 * us. If the interface is p2p as a--->b, then a routing entry exists
629 * If we now send a packet to b (e.g. ping b), this will come down here
630 * gets src=a, dst=b tacked on and would from ip_ouput() sent back to
631 * if_gre.
632 * Goal here is to compute a route to b that is less specific than
633 * a-->b. We know that this one exists as in normal operation we have
634 * at least a default route which matches.
635 */
636static int
637gre_compute_route(struct gre_softc *sc)
638{
639 struct route *ro;
640 u_int32_t a, b, c;
641
642 ro = &sc->route;
643
644 memset(ro, 0, sizeof(struct route));
645 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
646 ro->ro_dst.sa_family = AF_INET;
647 ro->ro_dst.sa_len = sizeof(ro->ro_dst);
648
649 /*
650 * toggle last bit, so our interface is not found, but a less
651 * specific route. I'd rather like to specify a shorter mask,
652 * but this is not possible. Should work though. XXX
653 * there is a simpler way ...
654 */
655 if ((sc->sc_if.if_flags & IFF_LINK1) == 0) {
656 a = ntohl(sc->g_dst.s_addr);
657 b = a & 0x01;
658 c = a & 0xfffffffe;
659 b = b ^ 0x01;
660 a = b | c;
661 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr
662 = htonl(a);
663 }
664
665#ifdef DIAGNOSTIC
666 printf("%s: searching a route to %s", if_name(&sc->sc_if),
667 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr));
668#endif
669
670 rtalloc(ro);
671
672 /*
673 * check if this returned a route at all and this route is no
674 * recursion to ourself
675 */
676 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) {
677#ifdef DIAGNOSTIC
678 if (ro->ro_rt == NULL)
679 printf(" - no route found!\n");
680 else
681 printf(" - route loops back to ourself!\n");
682#endif
683 return EADDRNOTAVAIL;
684 }
685
686 /*
687 * now change it back - else ip_output will just drop
688 * the route and search one to this interface ...
689 */
690 if ((sc->sc_if.if_flags & IFF_LINK1) == 0)
691 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
692
693#ifdef DIAGNOSTIC
694 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp),
695 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr));
696 printf("\n");
697#endif
698
699 return 0;
700}
701
702/*
703 * do a checksum of a buffer - much like in_cksum, which operates on
704 * mbufs.
705 */
706u_short
707gre_in_cksum(u_short *p, u_int len)
708{
709 u_int sum = 0;
710 int nwords = len >> 1;
711
712 while (nwords-- != 0)
713 sum += *p++;
714
715 if (len & 1) {
716 union {
717 u_short w;
718 u_char c[2];
719 } u;
720 u.c[0] = *(u_char *)p;
721 u.c[1] = 0;
722 sum += u.w;
723 }
724
725 /* end-around-carry */
726 sum = (sum >> 16) + (sum & 0xffff);
727 sum += (sum >> 16);
728 return (~sum);
729}
730
731static int
732gremodevent(module_t mod, int type, void *data)
733{
734
735 switch (type) {
736 case MOD_LOAD:
737 greattach();
738 break;
739 case MOD_UNLOAD:
740 if_clone_detach(&gre_cloner);
741
742 while (!LIST_EMPTY(&gre_softc_list))
743 gre_clone_destroy(&LIST_FIRST(&gre_softc_list)->sc_if);
744 break;
745 }
746 return 0;
747}
748
749static moduledata_t gre_mod = {
750 "if_gre",
751 gremodevent,
752 0
753};
754
755DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
756MODULE_VERSION(if_gre, 1);
|