xref: /dragonfly/sys/net/gif/if_gif.c (revision 8164c1fe) 
1 /*	$FreeBSD: src/sys/net/if_gif.c,v 1.4.2.15 2002/11/08 16:57:13 ume Exp $	*/
2 /*	$DragonFly: src/sys/net/gif/if_gif.c,v 1.11 2005/01/26 00:37:39 joerg Exp $	*/
3 /*	$KAME: if_gif.c,v 1.87 2001/10/19 08:50:27 itojun Exp $	*/
4 
5 /*
6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the project nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
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/malloc.h>
41 #include <sys/mbuf.h>
42 #include <sys/socket.h>
43 #include <sys/sockio.h>
44 #include <sys/errno.h>
45 #include <sys/time.h>
46 #include <sys/sysctl.h>
47 #include <sys/syslog.h>
48 #include <sys/protosw.h>
49 #include <sys/conf.h>
50 #include <machine/bus.h>	/* XXX: Shouldn't really be required! */
51 #include <machine/cpu.h>
52 
53 #include <net/if.h>
54 #include <net/if_types.h>
55 #include <net/netisr.h>
56 #include <net/route.h>
57 #include <net/bpf.h>
58 
59 #include <netinet/in.h>
60 #include <netinet/in_systm.h>
61 #include <netinet/ip.h>
62 #ifdef	INET
63 #include <netinet/in_var.h>
64 #include <netinet/in_gif.h>
65 #include <netinet/ip_var.h>
66 #endif	/* INET */
67 
68 #ifdef INET6
69 #ifndef INET
70 #include <netinet/in.h>
71 #endif
72 #include <netinet6/in6_var.h>
73 #include <netinet/ip6.h>
74 #include <netinet6/ip6_var.h>
75 #include <netinet6/in6_gif.h>
76 #include <netinet6/ip6protosw.h>
77 #endif /* INET6 */
78 
79 #include <netinet/ip_encap.h>
80 #include "if_gif.h"
81 
82 #include <net/net_osdep.h>
83 
84 #define GIFNAME		"gif"
85 
86 static MALLOC_DEFINE(M_GIF, "gif", "Generic Tunnel Interface");
87 LIST_HEAD(, gif_softc) gif_softc_list;
88 
89 int	gif_clone_create (struct if_clone *, int);
90 void	gif_clone_destroy (struct ifnet *);
91 
92 struct if_clone gif_cloner = IF_CLONE_INITIALIZER("gif", gif_clone_create,
93     gif_clone_destroy, 0, IF_MAXUNIT);
94 
95 static int gifmodevent (module_t, int, void *);
96 
97 SYSCTL_DECL(_net_link);
98 SYSCTL_NODE(_net_link, IFT_GIF, gif, CTLFLAG_RW, 0,
99     "Generic Tunnel Interface");
100 #ifndef MAX_GIF_NEST
101 /*
102  * This macro controls the default upper limitation on nesting of gif tunnels.
103  * Since, setting a large value to this macro with a careless configuration
104  * may introduce system crash, we don't allow any nestings by default.
105  * If you need to configure nested gif tunnels, you can define this macro
106  * in your kernel configuration file.  However, if you do so, please be
107  * careful to configure the tunnels so that it won't make a loop.
108  */
109 #define MAX_GIF_NEST 1
110 #endif
111 static int max_gif_nesting = MAX_GIF_NEST;
112 SYSCTL_INT(_net_link_gif, OID_AUTO, max_nesting, CTLFLAG_RW,
113     &max_gif_nesting, 0, "Max nested tunnels");
114 
115 /*
116  * By default, we disallow creation of multiple tunnels between the same
117  * pair of addresses.  Some applications require this functionality so
118  * we allow control over this check here.
119  */
120 #ifdef XBONEHACK
121 static int parallel_tunnels = 1;
122 #else
123 static int parallel_tunnels = 0;
124 #endif
125 SYSCTL_INT(_net_link_gif, OID_AUTO, parallel_tunnels, CTLFLAG_RW,
126     &parallel_tunnels, 0, "Allow parallel tunnels?");
127 
128 int
129 gif_clone_create(ifc, unit)
130 	struct if_clone *ifc;
131 	int unit;
132 {
133 	struct gif_softc *sc;
134 
135 	sc = malloc (sizeof(struct gif_softc), M_GIF, M_WAITOK);
136 	bzero(sc, sizeof(struct gif_softc));
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(sc)
149 	struct gif_softc *sc;
150 {
151 
152 	sc->encap_cookie4 = sc->encap_cookie6 = NULL;
153 
154 	sc->gif_if.if_addrlen = 0;
155 	sc->gif_if.if_mtu    = GIF_MTU;
156 	sc->gif_if.if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
157 #if 0
158 	/* turn off ingress filter */
159 	sc->gif_if.if_flags  |= IFF_LINK2;
160 #endif
161 	sc->gif_if.if_ioctl  = gif_ioctl;
162 	sc->gif_if.if_output = gif_output;
163 	sc->gif_if.if_type   = IFT_GIF;
164 	sc->gif_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
165 	if_attach(&sc->gif_if);
166 	bpfattach(&sc->gif_if, DLT_NULL, sizeof(u_int));
167 }
168 
169 void
170 gif_clone_destroy(ifp)
171 	struct ifnet *ifp;
172 {
173 	int err;
174 	struct gif_softc *sc = ifp->if_softc;
175 
176 	gif_delete_tunnel(&sc->gif_if);
177 	LIST_REMOVE(sc, gif_list);
178 #ifdef INET6
179 	if (sc->encap_cookie6 != NULL) {
180 		err = encap_detach(sc->encap_cookie6);
181 		KASSERT(err == 0, ("Unexpected error detaching encap_cookie6"));
182 	}
183 #endif
184 #ifdef INET
185 	if (sc->encap_cookie4 != NULL) {
186 		err = encap_detach(sc->encap_cookie4);
187 		KASSERT(err == 0, ("Unexpected error detaching encap_cookie4"));
188 	}
189 #endif
190 
191 	bpfdetach(ifp);
192 	if_detach(ifp);
193 
194 	free(sc, M_GIF);
195 }
196 
197 static int
198 gifmodevent(mod, type, data)
199 	module_t mod;
200 	int type;
201 	void *data;
202 {
203 
204 	switch (type) {
205 	case MOD_LOAD:
206 		LIST_INIT(&gif_softc_list);
207 		if_clone_attach(&gif_cloner);
208 
209 #ifdef INET6
210 		ip6_gif_hlim = GIF_HLIM;
211 #endif
212 
213 		break;
214 	case MOD_UNLOAD:
215 		if_clone_detach(&gif_cloner);
216 
217 		while (!LIST_EMPTY(&gif_softc_list))
218 			gif_clone_destroy(&LIST_FIRST(&gif_softc_list)->gif_if);
219 
220 #ifdef INET6
221 		ip6_gif_hlim = 0;
222 #endif
223 		break;
224 	}
225 	return 0;
226 }
227 
228 static moduledata_t gif_mod = {
229 	"if_gif",
230 	gifmodevent,
231 	0
232 };
233 
234 DECLARE_MODULE(if_gif, gif_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
235 
236 int
237 gif_encapcheck(m, off, proto, arg)
238 	const struct mbuf *m;
239 	int off;
240 	int proto;
241 	void *arg;
242 {
243 	struct ip ip;
244 	struct gif_softc *sc;
245 
246 	sc = (struct gif_softc *)arg;
247 	if (sc == NULL)
248 		return 0;
249 
250 	if ((sc->gif_if.if_flags & IFF_UP) == 0)
251 		return 0;
252 
253 	/* no physical address */
254 	if (!sc->gif_psrc || !sc->gif_pdst)
255 		return 0;
256 
257 	switch (proto) {
258 #ifdef INET
259 	case IPPROTO_IPV4:
260 		break;
261 #endif
262 #ifdef INET6
263 	case IPPROTO_IPV6:
264 		break;
265 #endif
266 	default:
267 		return 0;
268 	}
269 
270 	/* Bail on short packets */
271 	if (m->m_pkthdr.len < sizeof(ip))
272 		return 0;
273 
274 	m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
275 
276 	switch (ip.ip_v) {
277 #ifdef INET
278 	case 4:
279 		if (sc->gif_psrc->sa_family != AF_INET ||
280 		    sc->gif_pdst->sa_family != AF_INET)
281 			return 0;
282 		return gif_encapcheck4(m, off, proto, arg);
283 #endif
284 #ifdef INET6
285 	case 6:
286 		if (m->m_pkthdr.len < sizeof(struct ip6_hdr))
287 			return 0;
288 		if (sc->gif_psrc->sa_family != AF_INET6 ||
289 		    sc->gif_pdst->sa_family != AF_INET6)
290 			return 0;
291 		return gif_encapcheck6(m, off, proto, arg);
292 #endif
293 	default:
294 		return 0;
295 	}
296 }
297 
298 int
299 gif_output(ifp, m, dst, rt)
300 	struct ifnet *ifp;
301 	struct mbuf *m;
302 	struct sockaddr *dst;
303 	struct rtentry *rt;	/* added in net2 */
304 {
305 	struct gif_softc *sc = (struct gif_softc*)ifp;
306 	int error = 0;
307 	static int called = 0;	/* XXX: MUTEX */
308 
309 	/*
310 	 * gif may cause infinite recursion calls when misconfigured.
311 	 * We'll prevent this by introducing upper limit.
312 	 * XXX: this mechanism may introduce another problem about
313 	 *      mutual exclusion of the variable CALLED, especially if we
314 	 *      use kernel thread.
315 	 */
316 	if (++called > max_gif_nesting) {
317 		log(LOG_NOTICE,
318 		    "gif_output: recursively called too many times(%d)\n",
319 		    called);
320 		m_freem(m);
321 		error = EIO;	/* is there better errno? */
322 		goto end;
323 	}
324 
325 	m->m_flags &= ~(M_BCAST|M_MCAST);
326 	if (!(ifp->if_flags & IFF_UP) ||
327 	    sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
328 		m_freem(m);
329 		error = ENETDOWN;
330 		goto end;
331 	}
332 
333 	if (ifp->if_bpf) {
334 		/*
335 		 * We need to prepend the address family as
336 		 * a four byte field.
337 		 */
338 		uint32_t af = dst->sa_family;
339 
340 		bpf_ptap(ifp->if_bpf, m, &af, sizeof(4));
341 	}
342 	ifp->if_opackets++;
343 	ifp->if_obytes += m->m_pkthdr.len;
344 
345 	/* inner AF-specific encapsulation */
346 
347 	/* XXX should we check if our outer source is legal? */
348 
349 	/* dispatch to output logic based on outer AF */
350 	switch (sc->gif_psrc->sa_family) {
351 #ifdef INET
352 	case AF_INET:
353 		error = in_gif_output(ifp, dst->sa_family, m);
354 		break;
355 #endif
356 #ifdef INET6
357 	case AF_INET6:
358 		error = in6_gif_output(ifp, dst->sa_family, m);
359 		break;
360 #endif
361 	default:
362 		m_freem(m);
363 		error = ENETDOWN;
364 		goto end;
365 	}
366 
367   end:
368 	called = 0;		/* reset recursion counter */
369 	if (error)
370 		ifp->if_oerrors++;
371 	return error;
372 }
373 
374 void
375 gif_input(m, af, ifp)
376 	struct mbuf *m;
377 	int af;
378 	struct ifnet *ifp;
379 {
380 	int isr;
381 
382 	if (ifp == NULL) {
383 		/* just in case */
384 		m_freem(m);
385 		return;
386 	}
387 
388 	m->m_pkthdr.rcvif = ifp;
389 
390 	if (ifp->if_bpf) {
391 		/*
392 		 * We need to prepend the address family as
393 		 * a four byte field.
394 		 */
395 		uint32_t af1 = af;
396 
397 		bpf_ptap(ifp->if_bpf, m, &af1, sizeof(af1));
398 	}
399 
400 	/*
401 	 * Put the packet to the network layer input queue according to the
402 	 * specified address family.
403 	 * Note: older versions of gif_input directly called network layer
404 	 * input functions, e.g. ip6_input, here.  We changed the policy to
405 	 * prevent too many recursive calls of such input functions, which
406 	 * might cause kernel panic.  But the change may introduce another
407 	 * problem; if the input queue is full, packets are discarded.
408 	 * The kernel stack overflow really happened, and we believed
409 	 * queue-full rarely occurs, so we changed the policy.
410 	 */
411 	switch (af) {
412 #ifdef INET
413 	case AF_INET:
414 		isr = NETISR_IP;
415 		break;
416 #endif
417 #ifdef INET6
418 	case AF_INET6:
419 		isr = NETISR_IPV6;
420 		break;
421 #endif
422 	default:
423 		m_freem(m);
424 		return;
425 	}
426 
427 	ifp->if_ipackets++;
428 	ifp->if_ibytes += m->m_pkthdr.len;
429 	netisr_dispatch(isr, m);
430 
431 	return;
432 }
433 
434 /* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
435 int
436 gif_ioctl(ifp, cmd, data, cr)
437 	struct ifnet *ifp;
438 	u_long cmd;
439 	caddr_t data;
440 	struct ucred *cr;
441 {
442 	struct gif_softc *sc  = (struct gif_softc*)ifp;
443 	struct ifreq     *ifr = (struct ifreq*)data;
444 	int error = 0, size;
445 	struct sockaddr *dst, *src;
446 #ifdef	SIOCSIFMTU /* xxx */
447 	u_long mtu;
448 #endif
449 
450 	switch (cmd) {
451 	case SIOCSIFADDR:
452 		ifp->if_flags |= IFF_UP;
453 		break;
454 
455 	case SIOCSIFDSTADDR:
456 		break;
457 
458 	case SIOCADDMULTI:
459 	case SIOCDELMULTI:
460 		break;
461 
462 #ifdef	SIOCSIFMTU /* xxx */
463 	case SIOCGIFMTU:
464 		break;
465 
466 	case SIOCSIFMTU:
467 		mtu = ifr->ifr_mtu;
468 		if (mtu < GIF_MTU_MIN || mtu > GIF_MTU_MAX)
469 			return (EINVAL);
470 		ifp->if_mtu = mtu;
471 		break;
472 #endif /* SIOCSIFMTU */
473 
474 #ifdef INET
475 	case SIOCSIFPHYADDR:
476 #endif
477 #ifdef INET6
478 	case SIOCSIFPHYADDR_IN6:
479 #endif /* INET6 */
480 	case SIOCSLIFPHYADDR:
481 		switch (cmd) {
482 #ifdef INET
483 		case SIOCSIFPHYADDR:
484 			src = (struct sockaddr *)
485 				&(((struct in_aliasreq *)data)->ifra_addr);
486 			dst = (struct sockaddr *)
487 				&(((struct in_aliasreq *)data)->ifra_dstaddr);
488 			break;
489 #endif
490 #ifdef INET6
491 		case SIOCSIFPHYADDR_IN6:
492 			src = (struct sockaddr *)
493 				&(((struct in6_aliasreq *)data)->ifra_addr);
494 			dst = (struct sockaddr *)
495 				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
496 			break;
497 #endif
498 		case SIOCSLIFPHYADDR:
499 			src = (struct sockaddr *)
500 				&(((struct if_laddrreq *)data)->addr);
501 			dst = (struct sockaddr *)
502 				&(((struct if_laddrreq *)data)->dstaddr);
503 			break;
504 		default:
505 			return EINVAL;
506 		}
507 
508 		/* sa_family must be equal */
509 		if (src->sa_family != dst->sa_family)
510 			return EINVAL;
511 
512 		/* validate sa_len */
513 		switch (src->sa_family) {
514 #ifdef INET
515 		case AF_INET:
516 			if (src->sa_len != sizeof(struct sockaddr_in))
517 				return EINVAL;
518 			break;
519 #endif
520 #ifdef INET6
521 		case AF_INET6:
522 			if (src->sa_len != sizeof(struct sockaddr_in6))
523 				return EINVAL;
524 			break;
525 #endif
526 		default:
527 			return EAFNOSUPPORT;
528 		}
529 		switch (dst->sa_family) {
530 #ifdef INET
531 		case AF_INET:
532 			if (dst->sa_len != sizeof(struct sockaddr_in))
533 				return EINVAL;
534 			break;
535 #endif
536 #ifdef INET6
537 		case AF_INET6:
538 			if (dst->sa_len != sizeof(struct sockaddr_in6))
539 				return EINVAL;
540 			break;
541 #endif
542 		default:
543 			return EAFNOSUPPORT;
544 		}
545 
546 		/* check sa_family looks sane for the cmd */
547 		switch (cmd) {
548 		case SIOCSIFPHYADDR:
549 			if (src->sa_family == AF_INET)
550 				break;
551 			return EAFNOSUPPORT;
552 #ifdef INET6
553 		case SIOCSIFPHYADDR_IN6:
554 			if (src->sa_family == AF_INET6)
555 				break;
556 			return EAFNOSUPPORT;
557 #endif /* INET6 */
558 		case SIOCSLIFPHYADDR:
559 			/* checks done in the above */
560 			break;
561 		}
562 
563 		error = gif_set_tunnel(&sc->gif_if, src, dst);
564 		break;
565 
566 #ifdef SIOCDIFPHYADDR
567 	case SIOCDIFPHYADDR:
568 		gif_delete_tunnel(&sc->gif_if);
569 		break;
570 #endif
571 
572 	case SIOCGIFPSRCADDR:
573 #ifdef INET6
574 	case SIOCGIFPSRCADDR_IN6:
575 #endif /* INET6 */
576 		if (sc->gif_psrc == NULL) {
577 			error = EADDRNOTAVAIL;
578 			goto bad;
579 		}
580 		src = sc->gif_psrc;
581 		switch (cmd) {
582 #ifdef INET
583 		case SIOCGIFPSRCADDR:
584 			dst = &ifr->ifr_addr;
585 			size = sizeof(ifr->ifr_addr);
586 			break;
587 #endif /* INET */
588 #ifdef INET6
589 		case SIOCGIFPSRCADDR_IN6:
590 			dst = (struct sockaddr *)
591 				&(((struct in6_ifreq *)data)->ifr_addr);
592 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
593 			break;
594 #endif /* INET6 */
595 		default:
596 			error = EADDRNOTAVAIL;
597 			goto bad;
598 		}
599 		if (src->sa_len > size)
600 			return EINVAL;
601 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
602 		break;
603 
604 	case SIOCGIFPDSTADDR:
605 #ifdef INET6
606 	case SIOCGIFPDSTADDR_IN6:
607 #endif /* INET6 */
608 		if (sc->gif_pdst == NULL) {
609 			error = EADDRNOTAVAIL;
610 			goto bad;
611 		}
612 		src = sc->gif_pdst;
613 		switch (cmd) {
614 #ifdef INET
615 		case SIOCGIFPDSTADDR:
616 			dst = &ifr->ifr_addr;
617 			size = sizeof(ifr->ifr_addr);
618 			break;
619 #endif /* INET */
620 #ifdef INET6
621 		case SIOCGIFPDSTADDR_IN6:
622 			dst = (struct sockaddr *)
623 				&(((struct in6_ifreq *)data)->ifr_addr);
624 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
625 			break;
626 #endif /* INET6 */
627 		default:
628 			error = EADDRNOTAVAIL;
629 			goto bad;
630 		}
631 		if (src->sa_len > size)
632 			return EINVAL;
633 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
634 		break;
635 
636 	case SIOCGLIFPHYADDR:
637 		if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
638 			error = EADDRNOTAVAIL;
639 			goto bad;
640 		}
641 
642 		/* copy src */
643 		src = sc->gif_psrc;
644 		dst = (struct sockaddr *)
645 			&(((struct if_laddrreq *)data)->addr);
646 		size = sizeof(((struct if_laddrreq *)data)->addr);
647 		if (src->sa_len > size)
648 			return EINVAL;
649 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
650 
651 		/* copy dst */
652 		src = sc->gif_pdst;
653 		dst = (struct sockaddr *)
654 			&(((struct if_laddrreq *)data)->dstaddr);
655 		size = sizeof(((struct if_laddrreq *)data)->dstaddr);
656 		if (src->sa_len > size)
657 			return EINVAL;
658 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
659 		break;
660 
661 	case SIOCSIFFLAGS:
662 		/* if_ioctl() takes care of it */
663 		break;
664 
665 	default:
666 		error = EINVAL;
667 		break;
668 	}
669  bad:
670 	return error;
671 }
672 
673 int
674 gif_set_tunnel(ifp, src, dst)
675 	struct ifnet *ifp;
676 	struct sockaddr *src;
677 	struct sockaddr *dst;
678 {
679 	struct gif_softc *sc = (struct gif_softc *)ifp;
680 	struct gif_softc *sc2;
681 	struct sockaddr *osrc, *odst, *sa;
682 	int s;
683 	int error = 0;
684 
685 	s = splnet();
686 
687 	LIST_FOREACH(sc2, &gif_softc_list, gif_list) {
688 		if (sc2 == sc)
689 			continue;
690 		if (!sc2->gif_pdst || !sc2->gif_psrc)
691 			continue;
692 		if (sc2->gif_pdst->sa_family != dst->sa_family ||
693 		    sc2->gif_pdst->sa_len != dst->sa_len ||
694 		    sc2->gif_psrc->sa_family != src->sa_family ||
695 		    sc2->gif_psrc->sa_len != src->sa_len)
696 			continue;
697 
698 		/*
699 		 * Disallow parallel tunnels unless instructed
700 		 * otherwise.
701 		 */
702 		if (!parallel_tunnels &&
703 		    bcmp(sc2->gif_pdst, dst, dst->sa_len) == 0 &&
704 		    bcmp(sc2->gif_psrc, src, src->sa_len) == 0) {
705 			error = EADDRNOTAVAIL;
706 			goto bad;
707 		}
708 
709 		/* XXX both end must be valid? (I mean, not 0.0.0.0) */
710 	}
711 
712 	/* XXX we can detach from both, but be polite just in case */
713 	if (sc->gif_psrc)
714 		switch (sc->gif_psrc->sa_family) {
715 #ifdef INET
716 		case AF_INET:
717 			(void)in_gif_detach(sc);
718 			break;
719 #endif
720 #ifdef INET6
721 		case AF_INET6:
722 			(void)in6_gif_detach(sc);
723 			break;
724 #endif
725 		}
726 
727 	osrc = sc->gif_psrc;
728 	sa = (struct sockaddr *)malloc(src->sa_len, M_IFADDR, M_WAITOK);
729 	bcopy((caddr_t)src, (caddr_t)sa, src->sa_len);
730 	sc->gif_psrc = sa;
731 
732 	odst = sc->gif_pdst;
733 	sa = (struct sockaddr *)malloc(dst->sa_len, M_IFADDR, M_WAITOK);
734 	bcopy((caddr_t)dst, (caddr_t)sa, dst->sa_len);
735 	sc->gif_pdst = sa;
736 
737 	switch (sc->gif_psrc->sa_family) {
738 #ifdef INET
739 	case AF_INET:
740 		error = in_gif_attach(sc);
741 		break;
742 #endif
743 #ifdef INET6
744 	case AF_INET6:
745 		error = in6_gif_attach(sc);
746 		break;
747 #endif
748 	}
749 	if (error) {
750 		/* rollback */
751 		free((caddr_t)sc->gif_psrc, M_IFADDR);
752 		free((caddr_t)sc->gif_pdst, M_IFADDR);
753 		sc->gif_psrc = osrc;
754 		sc->gif_pdst = odst;
755 		goto bad;
756 	}
757 
758 	if (osrc)
759 		free((caddr_t)osrc, M_IFADDR);
760 	if (odst)
761 		free((caddr_t)odst, M_IFADDR);
762 
763 	if (sc->gif_psrc && sc->gif_pdst)
764 		ifp->if_flags |= IFF_RUNNING;
765 	else
766 		ifp->if_flags &= ~IFF_RUNNING;
767 	splx(s);
768 
769 	return 0;
770 
771  bad:
772 	if (sc->gif_psrc && sc->gif_pdst)
773 		ifp->if_flags |= IFF_RUNNING;
774 	else
775 		ifp->if_flags &= ~IFF_RUNNING;
776 	splx(s);
777 
778 	return error;
779 }
780 
781 void
782 gif_delete_tunnel(ifp)
783 	struct ifnet *ifp;
784 {
785 	struct gif_softc *sc = (struct gif_softc *)ifp;
786 	int s;
787 
788 	s = splnet();
789 
790 	if (sc->gif_psrc) {
791 		free((caddr_t)sc->gif_psrc, M_IFADDR);
792 		sc->gif_psrc = NULL;
793 	}
794 	if (sc->gif_pdst) {
795 		free((caddr_t)sc->gif_pdst, M_IFADDR);
796 		sc->gif_pdst = NULL;
797 	}
798 	/* it is safe to detach from both */
799 #ifdef INET
800 	(void)in_gif_detach(sc);
801 #endif
802 #ifdef INET6
803 	(void)in6_gif_detach(sc);
804 #endif
805 
806 	if (sc->gif_psrc && sc->gif_pdst)
807 		ifp->if_flags |= IFF_RUNNING;
808 	else
809 		ifp->if_flags &= ~IFF_RUNNING;
810 	splx(s);
811 }
812