xref: /dragonfly/sys/net/gif/if_gif.c (revision 029a4939) 
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 1.10 2004/11/30 19:21:26 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.  Cons up a dummy header
337 		 * to pacify bpf.  This is safe because bpf
338 		 * will only read from the mbuf (i.e., it won't
339 		 * try to free it or keep a pointer a to it).
340 		 */
341 		struct mbuf m0;
342 		u_int32_t af = dst->sa_family;
343 
344 		m0.m_next = m;
345 		m0.m_len = 4;
346 		m0.m_data = (char *)&af;
347 
348 		bpf_mtap(ifp, &m0);
349 	}
350 	ifp->if_opackets++;
351 	ifp->if_obytes += m->m_pkthdr.len;
352 
353 	/* inner AF-specific encapsulation */
354 
355 	/* XXX should we check if our outer source is legal? */
356 
357 	/* dispatch to output logic based on outer AF */
358 	switch (sc->gif_psrc->sa_family) {
359 #ifdef INET
360 	case AF_INET:
361 		error = in_gif_output(ifp, dst->sa_family, m);
362 		break;
363 #endif
364 #ifdef INET6
365 	case AF_INET6:
366 		error = in6_gif_output(ifp, dst->sa_family, m);
367 		break;
368 #endif
369 	default:
370 		m_freem(m);
371 		error = ENETDOWN;
372 		goto end;
373 	}
374 
375   end:
376 	called = 0;		/* reset recursion counter */
377 	if (error)
378 		ifp->if_oerrors++;
379 	return error;
380 }
381 
382 void
383 gif_input(m, af, ifp)
384 	struct mbuf *m;
385 	int af;
386 	struct ifnet *ifp;
387 {
388 	int isr;
389 
390 	if (ifp == NULL) {
391 		/* just in case */
392 		m_freem(m);
393 		return;
394 	}
395 
396 	m->m_pkthdr.rcvif = ifp;
397 
398 	if (ifp->if_bpf) {
399 		/*
400 		 * We need to prepend the address family as
401 		 * a four byte field.  Cons up a dummy header
402 		 * to pacify bpf.  This is safe because bpf
403 		 * will only read from the mbuf (i.e., it won't
404 		 * try to free it or keep a pointer a to it).
405 		 */
406 		struct mbuf m0;
407 		u_int32_t af1 = af;
408 
409 		m0.m_next = m;
410 		m0.m_len = 4;
411 		m0.m_data = (char *)&af1;
412 
413 		bpf_mtap(ifp, &m0);
414 	}
415 
416 	/*
417 	 * Put the packet to the network layer input queue according to the
418 	 * specified address family.
419 	 * Note: older versions of gif_input directly called network layer
420 	 * input functions, e.g. ip6_input, here.  We changed the policy to
421 	 * prevent too many recursive calls of such input functions, which
422 	 * might cause kernel panic.  But the change may introduce another
423 	 * problem; if the input queue is full, packets are discarded.
424 	 * The kernel stack overflow really happened, and we believed
425 	 * queue-full rarely occurs, so we changed the policy.
426 	 */
427 	switch (af) {
428 #ifdef INET
429 	case AF_INET:
430 		isr = NETISR_IP;
431 		break;
432 #endif
433 #ifdef INET6
434 	case AF_INET6:
435 		isr = NETISR_IPV6;
436 		break;
437 #endif
438 	default:
439 		m_freem(m);
440 		return;
441 	}
442 
443 	ifp->if_ipackets++;
444 	ifp->if_ibytes += m->m_pkthdr.len;
445 	netisr_dispatch(isr, m);
446 
447 	return;
448 }
449 
450 /* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
451 int
452 gif_ioctl(ifp, cmd, data, cr)
453 	struct ifnet *ifp;
454 	u_long cmd;
455 	caddr_t data;
456 	struct ucred *cr;
457 {
458 	struct gif_softc *sc  = (struct gif_softc*)ifp;
459 	struct ifreq     *ifr = (struct ifreq*)data;
460 	int error = 0, size;
461 	struct sockaddr *dst, *src;
462 #ifdef	SIOCSIFMTU /* xxx */
463 	u_long mtu;
464 #endif
465 
466 	switch (cmd) {
467 	case SIOCSIFADDR:
468 		ifp->if_flags |= IFF_UP;
469 		break;
470 
471 	case SIOCSIFDSTADDR:
472 		break;
473 
474 	case SIOCADDMULTI:
475 	case SIOCDELMULTI:
476 		break;
477 
478 #ifdef	SIOCSIFMTU /* xxx */
479 	case SIOCGIFMTU:
480 		break;
481 
482 	case SIOCSIFMTU:
483 		mtu = ifr->ifr_mtu;
484 		if (mtu < GIF_MTU_MIN || mtu > GIF_MTU_MAX)
485 			return (EINVAL);
486 		ifp->if_mtu = mtu;
487 		break;
488 #endif /* SIOCSIFMTU */
489 
490 #ifdef INET
491 	case SIOCSIFPHYADDR:
492 #endif
493 #ifdef INET6
494 	case SIOCSIFPHYADDR_IN6:
495 #endif /* INET6 */
496 	case SIOCSLIFPHYADDR:
497 		switch (cmd) {
498 #ifdef INET
499 		case SIOCSIFPHYADDR:
500 			src = (struct sockaddr *)
501 				&(((struct in_aliasreq *)data)->ifra_addr);
502 			dst = (struct sockaddr *)
503 				&(((struct in_aliasreq *)data)->ifra_dstaddr);
504 			break;
505 #endif
506 #ifdef INET6
507 		case SIOCSIFPHYADDR_IN6:
508 			src = (struct sockaddr *)
509 				&(((struct in6_aliasreq *)data)->ifra_addr);
510 			dst = (struct sockaddr *)
511 				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
512 			break;
513 #endif
514 		case SIOCSLIFPHYADDR:
515 			src = (struct sockaddr *)
516 				&(((struct if_laddrreq *)data)->addr);
517 			dst = (struct sockaddr *)
518 				&(((struct if_laddrreq *)data)->dstaddr);
519 			break;
520 		default:
521 			return EINVAL;
522 		}
523 
524 		/* sa_family must be equal */
525 		if (src->sa_family != dst->sa_family)
526 			return EINVAL;
527 
528 		/* validate sa_len */
529 		switch (src->sa_family) {
530 #ifdef INET
531 		case AF_INET:
532 			if (src->sa_len != sizeof(struct sockaddr_in))
533 				return EINVAL;
534 			break;
535 #endif
536 #ifdef INET6
537 		case AF_INET6:
538 			if (src->sa_len != sizeof(struct sockaddr_in6))
539 				return EINVAL;
540 			break;
541 #endif
542 		default:
543 			return EAFNOSUPPORT;
544 		}
545 		switch (dst->sa_family) {
546 #ifdef INET
547 		case AF_INET:
548 			if (dst->sa_len != sizeof(struct sockaddr_in))
549 				return EINVAL;
550 			break;
551 #endif
552 #ifdef INET6
553 		case AF_INET6:
554 			if (dst->sa_len != sizeof(struct sockaddr_in6))
555 				return EINVAL;
556 			break;
557 #endif
558 		default:
559 			return EAFNOSUPPORT;
560 		}
561 
562 		/* check sa_family looks sane for the cmd */
563 		switch (cmd) {
564 		case SIOCSIFPHYADDR:
565 			if (src->sa_family == AF_INET)
566 				break;
567 			return EAFNOSUPPORT;
568 #ifdef INET6
569 		case SIOCSIFPHYADDR_IN6:
570 			if (src->sa_family == AF_INET6)
571 				break;
572 			return EAFNOSUPPORT;
573 #endif /* INET6 */
574 		case SIOCSLIFPHYADDR:
575 			/* checks done in the above */
576 			break;
577 		}
578 
579 		error = gif_set_tunnel(&sc->gif_if, src, dst);
580 		break;
581 
582 #ifdef SIOCDIFPHYADDR
583 	case SIOCDIFPHYADDR:
584 		gif_delete_tunnel(&sc->gif_if);
585 		break;
586 #endif
587 
588 	case SIOCGIFPSRCADDR:
589 #ifdef INET6
590 	case SIOCGIFPSRCADDR_IN6:
591 #endif /* INET6 */
592 		if (sc->gif_psrc == NULL) {
593 			error = EADDRNOTAVAIL;
594 			goto bad;
595 		}
596 		src = sc->gif_psrc;
597 		switch (cmd) {
598 #ifdef INET
599 		case SIOCGIFPSRCADDR:
600 			dst = &ifr->ifr_addr;
601 			size = sizeof(ifr->ifr_addr);
602 			break;
603 #endif /* INET */
604 #ifdef INET6
605 		case SIOCGIFPSRCADDR_IN6:
606 			dst = (struct sockaddr *)
607 				&(((struct in6_ifreq *)data)->ifr_addr);
608 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
609 			break;
610 #endif /* INET6 */
611 		default:
612 			error = EADDRNOTAVAIL;
613 			goto bad;
614 		}
615 		if (src->sa_len > size)
616 			return EINVAL;
617 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
618 		break;
619 
620 	case SIOCGIFPDSTADDR:
621 #ifdef INET6
622 	case SIOCGIFPDSTADDR_IN6:
623 #endif /* INET6 */
624 		if (sc->gif_pdst == NULL) {
625 			error = EADDRNOTAVAIL;
626 			goto bad;
627 		}
628 		src = sc->gif_pdst;
629 		switch (cmd) {
630 #ifdef INET
631 		case SIOCGIFPDSTADDR:
632 			dst = &ifr->ifr_addr;
633 			size = sizeof(ifr->ifr_addr);
634 			break;
635 #endif /* INET */
636 #ifdef INET6
637 		case SIOCGIFPDSTADDR_IN6:
638 			dst = (struct sockaddr *)
639 				&(((struct in6_ifreq *)data)->ifr_addr);
640 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
641 			break;
642 #endif /* INET6 */
643 		default:
644 			error = EADDRNOTAVAIL;
645 			goto bad;
646 		}
647 		if (src->sa_len > size)
648 			return EINVAL;
649 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
650 		break;
651 
652 	case SIOCGLIFPHYADDR:
653 		if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
654 			error = EADDRNOTAVAIL;
655 			goto bad;
656 		}
657 
658 		/* copy src */
659 		src = sc->gif_psrc;
660 		dst = (struct sockaddr *)
661 			&(((struct if_laddrreq *)data)->addr);
662 		size = sizeof(((struct if_laddrreq *)data)->addr);
663 		if (src->sa_len > size)
664 			return EINVAL;
665 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
666 
667 		/* copy dst */
668 		src = sc->gif_pdst;
669 		dst = (struct sockaddr *)
670 			&(((struct if_laddrreq *)data)->dstaddr);
671 		size = sizeof(((struct if_laddrreq *)data)->dstaddr);
672 		if (src->sa_len > size)
673 			return EINVAL;
674 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
675 		break;
676 
677 	case SIOCSIFFLAGS:
678 		/* if_ioctl() takes care of it */
679 		break;
680 
681 	default:
682 		error = EINVAL;
683 		break;
684 	}
685  bad:
686 	return error;
687 }
688 
689 int
690 gif_set_tunnel(ifp, src, dst)
691 	struct ifnet *ifp;
692 	struct sockaddr *src;
693 	struct sockaddr *dst;
694 {
695 	struct gif_softc *sc = (struct gif_softc *)ifp;
696 	struct gif_softc *sc2;
697 	struct sockaddr *osrc, *odst, *sa;
698 	int s;
699 	int error = 0;
700 
701 	s = splnet();
702 
703 	LIST_FOREACH(sc2, &gif_softc_list, gif_list) {
704 		if (sc2 == sc)
705 			continue;
706 		if (!sc2->gif_pdst || !sc2->gif_psrc)
707 			continue;
708 		if (sc2->gif_pdst->sa_family != dst->sa_family ||
709 		    sc2->gif_pdst->sa_len != dst->sa_len ||
710 		    sc2->gif_psrc->sa_family != src->sa_family ||
711 		    sc2->gif_psrc->sa_len != src->sa_len)
712 			continue;
713 
714 		/*
715 		 * Disallow parallel tunnels unless instructed
716 		 * otherwise.
717 		 */
718 		if (!parallel_tunnels &&
719 		    bcmp(sc2->gif_pdst, dst, dst->sa_len) == 0 &&
720 		    bcmp(sc2->gif_psrc, src, src->sa_len) == 0) {
721 			error = EADDRNOTAVAIL;
722 			goto bad;
723 		}
724 
725 		/* XXX both end must be valid? (I mean, not 0.0.0.0) */
726 	}
727 
728 	/* XXX we can detach from both, but be polite just in case */
729 	if (sc->gif_psrc)
730 		switch (sc->gif_psrc->sa_family) {
731 #ifdef INET
732 		case AF_INET:
733 			(void)in_gif_detach(sc);
734 			break;
735 #endif
736 #ifdef INET6
737 		case AF_INET6:
738 			(void)in6_gif_detach(sc);
739 			break;
740 #endif
741 		}
742 
743 	osrc = sc->gif_psrc;
744 	sa = (struct sockaddr *)malloc(src->sa_len, M_IFADDR, M_WAITOK);
745 	bcopy((caddr_t)src, (caddr_t)sa, src->sa_len);
746 	sc->gif_psrc = sa;
747 
748 	odst = sc->gif_pdst;
749 	sa = (struct sockaddr *)malloc(dst->sa_len, M_IFADDR, M_WAITOK);
750 	bcopy((caddr_t)dst, (caddr_t)sa, dst->sa_len);
751 	sc->gif_pdst = sa;
752 
753 	switch (sc->gif_psrc->sa_family) {
754 #ifdef INET
755 	case AF_INET:
756 		error = in_gif_attach(sc);
757 		break;
758 #endif
759 #ifdef INET6
760 	case AF_INET6:
761 		error = in6_gif_attach(sc);
762 		break;
763 #endif
764 	}
765 	if (error) {
766 		/* rollback */
767 		free((caddr_t)sc->gif_psrc, M_IFADDR);
768 		free((caddr_t)sc->gif_pdst, M_IFADDR);
769 		sc->gif_psrc = osrc;
770 		sc->gif_pdst = odst;
771 		goto bad;
772 	}
773 
774 	if (osrc)
775 		free((caddr_t)osrc, M_IFADDR);
776 	if (odst)
777 		free((caddr_t)odst, M_IFADDR);
778 
779 	if (sc->gif_psrc && sc->gif_pdst)
780 		ifp->if_flags |= IFF_RUNNING;
781 	else
782 		ifp->if_flags &= ~IFF_RUNNING;
783 	splx(s);
784 
785 	return 0;
786 
787  bad:
788 	if (sc->gif_psrc && sc->gif_pdst)
789 		ifp->if_flags |= IFF_RUNNING;
790 	else
791 		ifp->if_flags &= ~IFF_RUNNING;
792 	splx(s);
793 
794 	return error;
795 }
796 
797 void
798 gif_delete_tunnel(ifp)
799 	struct ifnet *ifp;
800 {
801 	struct gif_softc *sc = (struct gif_softc *)ifp;
802 	int s;
803 
804 	s = splnet();
805 
806 	if (sc->gif_psrc) {
807 		free((caddr_t)sc->gif_psrc, M_IFADDR);
808 		sc->gif_psrc = NULL;
809 	}
810 	if (sc->gif_pdst) {
811 		free((caddr_t)sc->gif_pdst, M_IFADDR);
812 		sc->gif_pdst = NULL;
813 	}
814 	/* it is safe to detach from both */
815 #ifdef INET
816 	(void)in_gif_detach(sc);
817 #endif
818 #ifdef INET6
819 	(void)in6_gif_detach(sc);
820 #endif
821 
822 	if (sc->gif_psrc && sc->gif_pdst)
823 		ifp->if_flags |= IFF_RUNNING;
824 	else
825 		ifp->if_flags &= ~IFF_RUNNING;
826 	splx(s);
827 }
828