xref: /dragonfly/sys/net/gif/if_gif.c (revision 36a3d1d6) 
1 /*
2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the project nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD: src/sys/net/if_gif.c,v 1.4.2.15 2002/11/08 16:57:13 ume Exp $
30  * $DragonFly: src/sys/net/gif/if_gif.c,v 1.21 2008/05/14 11:59:23 sephe Exp $
31  * $KAME: if_gif.c,v 1.87 2001/10/19 08:50:27 itojun Exp $
32  */
33 
34 #include "opt_inet.h"
35 #include "opt_inet6.h"
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/bus.h>
41 #include <sys/malloc.h>
42 #include <sys/mbuf.h>
43 #include <sys/socket.h>
44 #include <sys/sockio.h>
45 #include <sys/errno.h>
46 #include <sys/time.h>
47 #include <sys/sysctl.h>
48 #include <sys/syslog.h>
49 #include <sys/protosw.h>
50 #include <sys/conf.h>
51 #include <sys/thread2.h>
52 
53 #include <machine/cpu.h>
54 
55 #include <net/if.h>
56 #include <net/if_types.h>
57 #include <net/netisr.h>
58 #include <net/route.h>
59 #include <net/bpf.h>
60 #include <net/if_clone.h>
61 
62 #include <netinet/in.h>
63 #include <netinet/in_systm.h>
64 #include <netinet/ip.h>
65 #ifdef	INET
66 #include <netinet/in_var.h>
67 #include <netinet/in_gif.h>
68 #include <netinet/ip_var.h>
69 #endif	/* INET */
70 
71 #ifdef INET6
72 #ifndef INET
73 #include <netinet/in.h>
74 #endif
75 #include <netinet6/in6_var.h>
76 #include <netinet/ip6.h>
77 #include <netinet6/ip6_var.h>
78 #include <netinet6/in6_gif.h>
79 #include <netinet6/ip6protosw.h>
80 #endif /* INET6 */
81 
82 #include <netinet/ip_encap.h>
83 #include "if_gif.h"
84 
85 #include <net/net_osdep.h>
86 
87 #define GIFNAME		"gif"
88 
89 static MALLOC_DEFINE(M_GIF, "gif", "Generic Tunnel Interface");
90 LIST_HEAD(, gif_softc) gif_softc_list;
91 
92 int	gif_clone_create (struct if_clone *, int, caddr_t);
93 void	gif_clone_destroy (struct ifnet *);
94 
95 struct if_clone gif_cloner = IF_CLONE_INITIALIZER("gif", gif_clone_create,
96     gif_clone_destroy, 0, IF_MAXUNIT);
97 
98 static int gifmodevent (module_t, int, void *);
99 
100 SYSCTL_DECL(_net_link);
101 SYSCTL_NODE(_net_link, IFT_GIF, gif, CTLFLAG_RW, 0,
102     "Generic Tunnel Interface");
103 #ifndef MAX_GIF_NEST
104 /*
105  * This macro controls the default upper limitation on nesting of gif tunnels.
106  * Since, setting a large value to this macro with a careless configuration
107  * may introduce system crash, we don't allow any nestings by default.
108  * If you need to configure nested gif tunnels, you can define this macro
109  * in your kernel configuration file.  However, if you do so, please be
110  * careful to configure the tunnels so that it won't make a loop.
111  */
112 #define MAX_GIF_NEST 1
113 #endif
114 static int max_gif_nesting = MAX_GIF_NEST;
115 SYSCTL_INT(_net_link_gif, OID_AUTO, max_nesting, CTLFLAG_RW,
116     &max_gif_nesting, 0, "Max nested tunnels");
117 
118 /*
119  * By default, we disallow creation of multiple tunnels between the same
120  * pair of addresses.  Some applications require this functionality so
121  * we allow control over this check here.
122  */
123 #ifdef XBONEHACK
124 static int parallel_tunnels = 1;
125 #else
126 static int parallel_tunnels = 0;
127 #endif
128 SYSCTL_INT(_net_link_gif, OID_AUTO, parallel_tunnels, CTLFLAG_RW,
129     &parallel_tunnels, 0, "Allow parallel tunnels?");
130 
131 int
132 gif_clone_create(struct if_clone *ifc, int unit, caddr_t params)
133 {
134 	struct gif_softc *sc;
135 
136 	sc = kmalloc (sizeof(struct gif_softc), M_GIF, M_WAITOK | M_ZERO);
137 
138 	sc->gif_if.if_softc = sc;
139 	if_initname(&(sc->gif_if), GIFNAME, unit);
140 
141 	gifattach0(sc);
142 
143 	LIST_INSERT_HEAD(&gif_softc_list, sc, gif_list);
144 	return (0);
145 }
146 
147 void
148 gifattach0(struct gif_softc *sc)
149 {
150 
151 	sc->encap_cookie4 = sc->encap_cookie6 = NULL;
152 
153 	sc->gif_if.if_addrlen = 0;
154 	sc->gif_if.if_mtu    = GIF_MTU;
155 	sc->gif_if.if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
156 #if 0
157 	/* turn off ingress filter */
158 	sc->gif_if.if_flags  |= IFF_LINK2;
159 #endif
160 	sc->gif_if.if_ioctl  = gif_ioctl;
161 	sc->gif_if.if_output = gif_output;
162 	sc->gif_if.if_type   = IFT_GIF;
163 	sc->gif_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
164 	if_attach(&sc->gif_if, NULL);
165 	bpfattach(&sc->gif_if, DLT_NULL, sizeof(u_int));
166 }
167 
168 void
169 gif_clone_destroy(struct ifnet *ifp)
170 {
171 	int err;
172 	struct gif_softc *sc = ifp->if_softc;
173 
174 	gif_delete_tunnel(&sc->gif_if);
175 	LIST_REMOVE(sc, gif_list);
176 #ifdef INET6
177 	if (sc->encap_cookie6 != NULL) {
178 		err = encap_detach(sc->encap_cookie6);
179 		KASSERT(err == 0, ("Unexpected error detaching encap_cookie6"));
180 	}
181 #endif
182 #ifdef INET
183 	if (sc->encap_cookie4 != NULL) {
184 		err = encap_detach(sc->encap_cookie4);
185 		KASSERT(err == 0, ("Unexpected error detaching encap_cookie4"));
186 	}
187 #endif
188 
189 	bpfdetach(ifp);
190 	if_detach(ifp);
191 
192 	kfree(sc, M_GIF);
193 }
194 
195 static int
196 gifmodevent(module_t mod, int type, void *data)
197 {
198 
199 	switch (type) {
200 	case MOD_LOAD:
201 		LIST_INIT(&gif_softc_list);
202 		if_clone_attach(&gif_cloner);
203 
204 #ifdef INET6
205 		ip6_gif_hlim = GIF_HLIM;
206 #endif
207 
208 		break;
209 	case MOD_UNLOAD:
210 		if_clone_detach(&gif_cloner);
211 
212 		while (!LIST_EMPTY(&gif_softc_list))
213 			gif_clone_destroy(&LIST_FIRST(&gif_softc_list)->gif_if);
214 
215 #ifdef INET6
216 		ip6_gif_hlim = 0;
217 #endif
218 		break;
219 	}
220 	return 0;
221 }
222 
223 static moduledata_t gif_mod = {
224 	"if_gif",
225 	gifmodevent,
226 	0
227 };
228 
229 DECLARE_MODULE(if_gif, gif_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
230 
231 int
232 gif_encapcheck(const struct mbuf *m, int off, int proto, void *arg)
233 {
234 	struct ip ip;
235 	struct gif_softc *sc;
236 
237 	sc = (struct gif_softc *)arg;
238 	if (sc == NULL)
239 		return 0;
240 
241 	if ((sc->gif_if.if_flags & IFF_UP) == 0)
242 		return 0;
243 
244 	/* no physical address */
245 	if (!sc->gif_psrc || !sc->gif_pdst)
246 		return 0;
247 
248 	switch (proto) {
249 #ifdef INET
250 	case IPPROTO_IPV4:
251 		break;
252 #endif
253 #ifdef INET6
254 	case IPPROTO_IPV6:
255 		break;
256 #endif
257 	default:
258 		return 0;
259 	}
260 
261 	/* Bail on short packets */
262 	if (m->m_pkthdr.len < sizeof(ip))
263 		return 0;
264 
265 	m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
266 
267 	switch (ip.ip_v) {
268 #ifdef INET
269 	case 4:
270 		if (sc->gif_psrc->sa_family != AF_INET ||
271 		    sc->gif_pdst->sa_family != AF_INET)
272 			return 0;
273 		return gif_encapcheck4(m, off, proto, arg);
274 #endif
275 #ifdef INET6
276 	case 6:
277 		if (m->m_pkthdr.len < sizeof(struct ip6_hdr))
278 			return 0;
279 		if (sc->gif_psrc->sa_family != AF_INET6 ||
280 		    sc->gif_pdst->sa_family != AF_INET6)
281 			return 0;
282 		return gif_encapcheck6(m, off, proto, arg);
283 #endif
284 	default:
285 		return 0;
286 	}
287 }
288 
289 /*
290  * Parameters:
291  *	rt:	added in net2
292  */
293 static int
294 gif_output_serialized(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
295 		      struct rtentry *rt)
296 {
297 	struct gif_softc *sc = (struct gif_softc*)ifp;
298 	int error = 0;
299 	static int called = 0;	/* XXX: MUTEX */
300 
301 	/*
302 	 * gif may cause infinite recursion calls when misconfigured.
303 	 * We'll prevent this by introducing upper limit.
304 	 * XXX: this mechanism may introduce another problem about
305 	 *      mutual exclusion of the variable CALLED, especially if we
306 	 *      use kernel thread.
307 	 */
308 	if (++called > max_gif_nesting) {
309 		log(LOG_NOTICE,
310 		    "gif_output: recursively called too many times(%d)\n",
311 		    called);
312 		m_freem(m);
313 		error = EIO;	/* is there better errno? */
314 		goto end;
315 	}
316 
317 	m->m_flags &= ~(M_BCAST|M_MCAST);
318 	if (!(ifp->if_flags & IFF_UP) ||
319 	    sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
320 		m_freem(m);
321 		error = ENETDOWN;
322 		goto end;
323 	}
324 
325 	if (ifp->if_bpf) {
326 		/*
327 		 * We need to prepend the address family as
328 		 * a four byte field.
329 		 */
330 		uint32_t af = dst->sa_family;
331 
332 		bpf_ptap(ifp->if_bpf, m, &af, sizeof(4));
333 	}
334 	ifp->if_opackets++;
335 	ifp->if_obytes += m->m_pkthdr.len;
336 
337 	/* inner AF-specific encapsulation */
338 
339 	/* XXX should we check if our outer source is legal? */
340 
341 	/* dispatch to output logic based on outer AF */
342 	switch (sc->gif_psrc->sa_family) {
343 #ifdef INET
344 	case AF_INET:
345 		error = in_gif_output(ifp, dst->sa_family, m);
346 		break;
347 #endif
348 #ifdef INET6
349 	case AF_INET6:
350 		error = in6_gif_output(ifp, dst->sa_family, m);
351 		break;
352 #endif
353 	default:
354 		m_freem(m);
355 		error = ENETDOWN;
356 		goto end;
357 	}
358 
359   end:
360 	called = 0;		/* reset recursion counter */
361 	if (error)
362 		ifp->if_oerrors++;
363 	return error;
364 }
365 
366 int
367 gif_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
368 	   struct rtentry *rt)
369 {
370 	int error;
371 
372 	ifnet_serialize_tx(ifp);
373 	error = gif_output_serialized(ifp, m, dst, rt);
374 	ifnet_deserialize_tx(ifp);
375 	return error;
376 }
377 
378 void
379 gif_input(struct mbuf *m, int af, struct ifnet *ifp)
380 {
381 	int isr;
382 
383 	if (ifp == NULL) {
384 		/* just in case */
385 		m_freem(m);
386 		return;
387 	}
388 
389 	m->m_pkthdr.rcvif = ifp;
390 
391 	if (ifp->if_bpf) {
392 		/*
393 		 * We need to prepend the address family as
394 		 * a four byte field.
395 		 */
396 		uint32_t af1 = af;
397 
398 		bpf_ptap(ifp->if_bpf, m, &af1, sizeof(af1));
399 	}
400 
401 	/*
402 	 * Put the packet to the network layer input queue according to the
403 	 * specified address family.
404 	 * Note: older versions of gif_input directly called network layer
405 	 * input functions, e.g. ip6_input, here.  We changed the policy to
406 	 * prevent too many recursive calls of such input functions, which
407 	 * might cause kernel panic.  But the change may introduce another
408 	 * problem; if the input queue is full, packets are discarded.
409 	 * The kernel stack overflow really happened, and we believed
410 	 * queue-full rarely occurs, so we changed the policy.
411 	 */
412 	switch (af) {
413 #ifdef INET
414 	case AF_INET:
415 		isr = NETISR_IP;
416 		break;
417 #endif
418 #ifdef INET6
419 	case AF_INET6:
420 		isr = NETISR_IPV6;
421 		break;
422 #endif
423 	default:
424 		m_freem(m);
425 		return;
426 	}
427 
428 	ifp->if_ipackets++;
429 	ifp->if_ibytes += m->m_pkthdr.len;
430 	netisr_dispatch(isr, m);
431 
432 	return;
433 }
434 
435 /* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
436 int
437 gif_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
438 {
439 	struct gif_softc *sc  = (struct gif_softc*)ifp;
440 	struct ifreq     *ifr = (struct ifreq*)data;
441 	int error = 0, size;
442 	struct sockaddr *dst, *src;
443 #ifdef	SIOCSIFMTU /* xxx */
444 	u_long mtu;
445 #endif
446 
447 	switch (cmd) {
448 	case SIOCSIFADDR:
449 		ifp->if_flags |= IFF_UP;
450 		break;
451 
452 	case SIOCSIFDSTADDR:
453 		break;
454 
455 	case SIOCADDMULTI:
456 	case SIOCDELMULTI:
457 		break;
458 
459 #ifdef	SIOCSIFMTU /* xxx */
460 	case SIOCGIFMTU:
461 		break;
462 
463 	case SIOCSIFMTU:
464 		mtu = ifr->ifr_mtu;
465 		if (mtu < GIF_MTU_MIN || mtu > GIF_MTU_MAX)
466 			return (EINVAL);
467 		ifp->if_mtu = mtu;
468 		break;
469 #endif /* SIOCSIFMTU */
470 
471 #ifdef INET
472 	case SIOCSIFPHYADDR:
473 #endif
474 #ifdef INET6
475 	case SIOCSIFPHYADDR_IN6:
476 #endif /* INET6 */
477 	case SIOCSLIFPHYADDR:
478 		switch (cmd) {
479 #ifdef INET
480 		case SIOCSIFPHYADDR:
481 			src = (struct sockaddr *)
482 				&(((struct in_aliasreq *)data)->ifra_addr);
483 			dst = (struct sockaddr *)
484 				&(((struct in_aliasreq *)data)->ifra_dstaddr);
485 			break;
486 #endif
487 #ifdef INET6
488 		case SIOCSIFPHYADDR_IN6:
489 			src = (struct sockaddr *)
490 				&(((struct in6_aliasreq *)data)->ifra_addr);
491 			dst = (struct sockaddr *)
492 				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
493 			break;
494 #endif
495 		case SIOCSLIFPHYADDR:
496 			src = (struct sockaddr *)
497 				&(((struct if_laddrreq *)data)->addr);
498 			dst = (struct sockaddr *)
499 				&(((struct if_laddrreq *)data)->dstaddr);
500 			break;
501 		default:
502 			return EINVAL;
503 		}
504 
505 		/* sa_family must be equal */
506 		if (src->sa_family != dst->sa_family)
507 			return EINVAL;
508 
509 		/* validate sa_len */
510 		switch (src->sa_family) {
511 #ifdef INET
512 		case AF_INET:
513 			if (src->sa_len != sizeof(struct sockaddr_in))
514 				return EINVAL;
515 			break;
516 #endif
517 #ifdef INET6
518 		case AF_INET6:
519 			if (src->sa_len != sizeof(struct sockaddr_in6))
520 				return EINVAL;
521 			break;
522 #endif
523 		default:
524 			return EAFNOSUPPORT;
525 		}
526 		switch (dst->sa_family) {
527 #ifdef INET
528 		case AF_INET:
529 			if (dst->sa_len != sizeof(struct sockaddr_in))
530 				return EINVAL;
531 			break;
532 #endif
533 #ifdef INET6
534 		case AF_INET6:
535 			if (dst->sa_len != sizeof(struct sockaddr_in6))
536 				return EINVAL;
537 			break;
538 #endif
539 		default:
540 			return EAFNOSUPPORT;
541 		}
542 
543 		/* check sa_family looks sane for the cmd */
544 		switch (cmd) {
545 		case SIOCSIFPHYADDR:
546 			if (src->sa_family == AF_INET)
547 				break;
548 			return EAFNOSUPPORT;
549 #ifdef INET6
550 		case SIOCSIFPHYADDR_IN6:
551 			if (src->sa_family == AF_INET6)
552 				break;
553 			return EAFNOSUPPORT;
554 #endif /* INET6 */
555 		case SIOCSLIFPHYADDR:
556 			/* checks done in the above */
557 			break;
558 		}
559 
560 		error = gif_set_tunnel(&sc->gif_if, src, dst);
561 		break;
562 
563 #ifdef SIOCDIFPHYADDR
564 	case SIOCDIFPHYADDR:
565 		gif_delete_tunnel(&sc->gif_if);
566 		break;
567 #endif
568 
569 	case SIOCGIFPSRCADDR:
570 #ifdef INET6
571 	case SIOCGIFPSRCADDR_IN6:
572 #endif /* INET6 */
573 		if (sc->gif_psrc == NULL) {
574 			error = EADDRNOTAVAIL;
575 			goto bad;
576 		}
577 		src = sc->gif_psrc;
578 		switch (cmd) {
579 #ifdef INET
580 		case SIOCGIFPSRCADDR:
581 			dst = &ifr->ifr_addr;
582 			size = sizeof(ifr->ifr_addr);
583 			break;
584 #endif /* INET */
585 #ifdef INET6
586 		case SIOCGIFPSRCADDR_IN6:
587 			dst = (struct sockaddr *)
588 				&(((struct in6_ifreq *)data)->ifr_addr);
589 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
590 			break;
591 #endif /* INET6 */
592 		default:
593 			error = EADDRNOTAVAIL;
594 			goto bad;
595 		}
596 		if (src->sa_len > size)
597 			return EINVAL;
598 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
599 		break;
600 
601 	case SIOCGIFPDSTADDR:
602 #ifdef INET6
603 	case SIOCGIFPDSTADDR_IN6:
604 #endif /* INET6 */
605 		if (sc->gif_pdst == NULL) {
606 			error = EADDRNOTAVAIL;
607 			goto bad;
608 		}
609 		src = sc->gif_pdst;
610 		switch (cmd) {
611 #ifdef INET
612 		case SIOCGIFPDSTADDR:
613 			dst = &ifr->ifr_addr;
614 			size = sizeof(ifr->ifr_addr);
615 			break;
616 #endif /* INET */
617 #ifdef INET6
618 		case SIOCGIFPDSTADDR_IN6:
619 			dst = (struct sockaddr *)
620 				&(((struct in6_ifreq *)data)->ifr_addr);
621 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
622 			break;
623 #endif /* INET6 */
624 		default:
625 			error = EADDRNOTAVAIL;
626 			goto bad;
627 		}
628 		if (src->sa_len > size)
629 			return EINVAL;
630 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
631 		break;
632 
633 	case SIOCGLIFPHYADDR:
634 		if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
635 			error = EADDRNOTAVAIL;
636 			goto bad;
637 		}
638 
639 		/* copy src */
640 		src = sc->gif_psrc;
641 		dst = (struct sockaddr *)
642 			&(((struct if_laddrreq *)data)->addr);
643 		size = sizeof(((struct if_laddrreq *)data)->addr);
644 		if (src->sa_len > size)
645 			return EINVAL;
646 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
647 
648 		/* copy dst */
649 		src = sc->gif_pdst;
650 		dst = (struct sockaddr *)
651 			&(((struct if_laddrreq *)data)->dstaddr);
652 		size = sizeof(((struct if_laddrreq *)data)->dstaddr);
653 		if (src->sa_len > size)
654 			return EINVAL;
655 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
656 		break;
657 
658 	case SIOCSIFFLAGS:
659 		/* if_ioctl() takes care of it */
660 		break;
661 
662 	default:
663 		error = EINVAL;
664 		break;
665 	}
666  bad:
667 	return error;
668 }
669 
670 int
671 gif_set_tunnel(struct ifnet *ifp, struct sockaddr *src, struct sockaddr *dst)
672 {
673 	struct gif_softc *sc = (struct gif_softc *)ifp;
674 	struct gif_softc *sc2;
675 	struct sockaddr *osrc, *odst, *sa;
676 	int error = 0;
677 
678 	crit_enter();
679 
680 	LIST_FOREACH(sc2, &gif_softc_list, gif_list) {
681 		if (sc2 == sc)
682 			continue;
683 		if (!sc2->gif_pdst || !sc2->gif_psrc)
684 			continue;
685 		if (sc2->gif_pdst->sa_family != dst->sa_family ||
686 		    sc2->gif_pdst->sa_len != dst->sa_len ||
687 		    sc2->gif_psrc->sa_family != src->sa_family ||
688 		    sc2->gif_psrc->sa_len != src->sa_len)
689 			continue;
690 
691 		/*
692 		 * Disallow parallel tunnels unless instructed
693 		 * otherwise.
694 		 */
695 		if (!parallel_tunnels &&
696 		    bcmp(sc2->gif_pdst, dst, dst->sa_len) == 0 &&
697 		    bcmp(sc2->gif_psrc, src, src->sa_len) == 0) {
698 			error = EADDRNOTAVAIL;
699 			goto bad;
700 		}
701 
702 		/* XXX both end must be valid? (I mean, not 0.0.0.0) */
703 	}
704 
705 	/* XXX we can detach from both, but be polite just in case */
706 	if (sc->gif_psrc)
707 		switch (sc->gif_psrc->sa_family) {
708 #ifdef INET
709 		case AF_INET:
710 			in_gif_detach(sc);
711 			break;
712 #endif
713 #ifdef INET6
714 		case AF_INET6:
715 			in6_gif_detach(sc);
716 			break;
717 #endif
718 		}
719 
720 	osrc = sc->gif_psrc;
721 	sa = (struct sockaddr *)kmalloc(src->sa_len, M_IFADDR, M_WAITOK);
722 	bcopy((caddr_t)src, (caddr_t)sa, src->sa_len);
723 	sc->gif_psrc = sa;
724 
725 	odst = sc->gif_pdst;
726 	sa = (struct sockaddr *)kmalloc(dst->sa_len, M_IFADDR, M_WAITOK);
727 	bcopy((caddr_t)dst, (caddr_t)sa, dst->sa_len);
728 	sc->gif_pdst = sa;
729 
730 	switch (sc->gif_psrc->sa_family) {
731 #ifdef INET
732 	case AF_INET:
733 		error = in_gif_attach(sc);
734 		break;
735 #endif
736 #ifdef INET6
737 	case AF_INET6:
738 		error = in6_gif_attach(sc);
739 		break;
740 #endif
741 	}
742 	if (error) {
743 		/* rollback */
744 		kfree((caddr_t)sc->gif_psrc, M_IFADDR);
745 		kfree((caddr_t)sc->gif_pdst, M_IFADDR);
746 		sc->gif_psrc = osrc;
747 		sc->gif_pdst = odst;
748 		goto bad;
749 	}
750 
751 	if (osrc)
752 		kfree((caddr_t)osrc, M_IFADDR);
753 	if (odst)
754 		kfree((caddr_t)odst, M_IFADDR);
755 
756 	if (sc->gif_psrc && sc->gif_pdst)
757 		ifp->if_flags |= IFF_RUNNING;
758 	else
759 		ifp->if_flags &= ~IFF_RUNNING;
760 	crit_exit();
761 
762 	return 0;
763 
764  bad:
765 	if (sc->gif_psrc && sc->gif_pdst)
766 		ifp->if_flags |= IFF_RUNNING;
767 	else
768 		ifp->if_flags &= ~IFF_RUNNING;
769 	crit_exit();
770 
771 	return error;
772 }
773 
774 void
775 gif_delete_tunnel(struct ifnet *ifp)
776 {
777 	struct gif_softc *sc = (struct gif_softc *)ifp;
778 
779 	crit_enter();
780 
781 	if (sc->gif_psrc) {
782 		kfree((caddr_t)sc->gif_psrc, M_IFADDR);
783 		sc->gif_psrc = NULL;
784 	}
785 	if (sc->gif_pdst) {
786 		kfree((caddr_t)sc->gif_pdst, M_IFADDR);
787 		sc->gif_pdst = NULL;
788 	}
789 	/* it is safe to detach from both */
790 #ifdef INET
791 	in_gif_detach(sc);
792 #endif
793 #ifdef INET6
794 	in6_gif_detach(sc);
795 #endif
796 
797 	if (sc->gif_psrc && sc->gif_pdst)
798 		ifp->if_flags |= IFF_RUNNING;
799 	else
800 		ifp->if_flags &= ~IFF_RUNNING;
801 	crit_exit();
802 }
803