xref: /dragonfly/sys/net/gif/if_gif.c (revision 1bf4b486) 
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 1.13 2005/06/03 18:20:36 swildner 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 <sys/thread2.h>
51 #include <machine/bus.h>	/* XXX: Shouldn't really be required! */
52 #include <machine/cpu.h>
53 
54 #include <net/if.h>
55 #include <net/if_types.h>
56 #include <net/netisr.h>
57 #include <net/route.h>
58 #include <net/bpf.h>
59 
60 #include <netinet/in.h>
61 #include <netinet/in_systm.h>
62 #include <netinet/ip.h>
63 #ifdef	INET
64 #include <netinet/in_var.h>
65 #include <netinet/in_gif.h>
66 #include <netinet/ip_var.h>
67 #endif	/* INET */
68 
69 #ifdef INET6
70 #ifndef INET
71 #include <netinet/in.h>
72 #endif
73 #include <netinet6/in6_var.h>
74 #include <netinet/ip6.h>
75 #include <netinet6/ip6_var.h>
76 #include <netinet6/in6_gif.h>
77 #include <netinet6/ip6protosw.h>
78 #endif /* INET6 */
79 
80 #include <netinet/ip_encap.h>
81 #include "if_gif.h"
82 
83 #include <net/net_osdep.h>
84 
85 #define GIFNAME		"gif"
86 
87 static MALLOC_DEFINE(M_GIF, "gif", "Generic Tunnel Interface");
88 LIST_HEAD(, gif_softc) gif_softc_list;
89 
90 int	gif_clone_create (struct if_clone *, int);
91 void	gif_clone_destroy (struct ifnet *);
92 
93 struct if_clone gif_cloner = IF_CLONE_INITIALIZER("gif", gif_clone_create,
94     gif_clone_destroy, 0, IF_MAXUNIT);
95 
96 static int gifmodevent (module_t, int, void *);
97 
98 SYSCTL_DECL(_net_link);
99 SYSCTL_NODE(_net_link, IFT_GIF, gif, CTLFLAG_RW, 0,
100     "Generic Tunnel Interface");
101 #ifndef MAX_GIF_NEST
102 /*
103  * This macro controls the default upper limitation on nesting of gif tunnels.
104  * Since, setting a large value to this macro with a careless configuration
105  * may introduce system crash, we don't allow any nestings by default.
106  * If you need to configure nested gif tunnels, you can define this macro
107  * in your kernel configuration file.  However, if you do so, please be
108  * careful to configure the tunnels so that it won't make a loop.
109  */
110 #define MAX_GIF_NEST 1
111 #endif
112 static int max_gif_nesting = MAX_GIF_NEST;
113 SYSCTL_INT(_net_link_gif, OID_AUTO, max_nesting, CTLFLAG_RW,
114     &max_gif_nesting, 0, "Max nested tunnels");
115 
116 /*
117  * By default, we disallow creation of multiple tunnels between the same
118  * pair of addresses.  Some applications require this functionality so
119  * we allow control over this check here.
120  */
121 #ifdef XBONEHACK
122 static int parallel_tunnels = 1;
123 #else
124 static int parallel_tunnels = 0;
125 #endif
126 SYSCTL_INT(_net_link_gif, OID_AUTO, parallel_tunnels, CTLFLAG_RW,
127     &parallel_tunnels, 0, "Allow parallel tunnels?");
128 
129 int
130 gif_clone_create(ifc, unit)
131 	struct if_clone *ifc;
132 	int unit;
133 {
134 	struct gif_softc *sc;
135 
136 	sc = malloc (sizeof(struct gif_softc), M_GIF, M_WAITOK);
137 	bzero(sc, sizeof(struct gif_softc));
138 
139 	sc->gif_if.if_softc = sc;
140 	if_initname(&(sc->gif_if), GIFNAME, unit);
141 
142 	gifattach0(sc);
143 
144 	LIST_INSERT_HEAD(&gif_softc_list, sc, gif_list);
145 	return (0);
146 }
147 
148 void
149 gifattach0(sc)
150 	struct gif_softc *sc;
151 {
152 
153 	sc->encap_cookie4 = sc->encap_cookie6 = NULL;
154 
155 	sc->gif_if.if_addrlen = 0;
156 	sc->gif_if.if_mtu    = GIF_MTU;
157 	sc->gif_if.if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
158 #if 0
159 	/* turn off ingress filter */
160 	sc->gif_if.if_flags  |= IFF_LINK2;
161 #endif
162 	sc->gif_if.if_ioctl  = gif_ioctl;
163 	sc->gif_if.if_output = gif_output;
164 	sc->gif_if.if_type   = IFT_GIF;
165 	sc->gif_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
166 	if_attach(&sc->gif_if);
167 	bpfattach(&sc->gif_if, DLT_NULL, sizeof(u_int));
168 }
169 
170 void
171 gif_clone_destroy(ifp)
172 	struct ifnet *ifp;
173 {
174 	int err;
175 	struct gif_softc *sc = ifp->if_softc;
176 
177 	gif_delete_tunnel(&sc->gif_if);
178 	LIST_REMOVE(sc, gif_list);
179 #ifdef INET6
180 	if (sc->encap_cookie6 != NULL) {
181 		err = encap_detach(sc->encap_cookie6);
182 		KASSERT(err == 0, ("Unexpected error detaching encap_cookie6"));
183 	}
184 #endif
185 #ifdef INET
186 	if (sc->encap_cookie4 != NULL) {
187 		err = encap_detach(sc->encap_cookie4);
188 		KASSERT(err == 0, ("Unexpected error detaching encap_cookie4"));
189 	}
190 #endif
191 
192 	bpfdetach(ifp);
193 	if_detach(ifp);
194 
195 	free(sc, M_GIF);
196 }
197 
198 static int
199 gifmodevent(mod, type, data)
200 	module_t mod;
201 	int type;
202 	void *data;
203 {
204 
205 	switch (type) {
206 	case MOD_LOAD:
207 		LIST_INIT(&gif_softc_list);
208 		if_clone_attach(&gif_cloner);
209 
210 #ifdef INET6
211 		ip6_gif_hlim = GIF_HLIM;
212 #endif
213 
214 		break;
215 	case MOD_UNLOAD:
216 		if_clone_detach(&gif_cloner);
217 
218 		while (!LIST_EMPTY(&gif_softc_list))
219 			gif_clone_destroy(&LIST_FIRST(&gif_softc_list)->gif_if);
220 
221 #ifdef INET6
222 		ip6_gif_hlim = 0;
223 #endif
224 		break;
225 	}
226 	return 0;
227 }
228 
229 static moduledata_t gif_mod = {
230 	"if_gif",
231 	gifmodevent,
232 	0
233 };
234 
235 DECLARE_MODULE(if_gif, gif_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
236 
237 int
238 gif_encapcheck(m, off, proto, arg)
239 	const struct mbuf *m;
240 	int off;
241 	int proto;
242 	void *arg;
243 {
244 	struct ip ip;
245 	struct gif_softc *sc;
246 
247 	sc = (struct gif_softc *)arg;
248 	if (sc == NULL)
249 		return 0;
250 
251 	if ((sc->gif_if.if_flags & IFF_UP) == 0)
252 		return 0;
253 
254 	/* no physical address */
255 	if (!sc->gif_psrc || !sc->gif_pdst)
256 		return 0;
257 
258 	switch (proto) {
259 #ifdef INET
260 	case IPPROTO_IPV4:
261 		break;
262 #endif
263 #ifdef INET6
264 	case IPPROTO_IPV6:
265 		break;
266 #endif
267 	default:
268 		return 0;
269 	}
270 
271 	/* Bail on short packets */
272 	if (m->m_pkthdr.len < sizeof(ip))
273 		return 0;
274 
275 	m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
276 
277 	switch (ip.ip_v) {
278 #ifdef INET
279 	case 4:
280 		if (sc->gif_psrc->sa_family != AF_INET ||
281 		    sc->gif_pdst->sa_family != AF_INET)
282 			return 0;
283 		return gif_encapcheck4(m, off, proto, arg);
284 #endif
285 #ifdef INET6
286 	case 6:
287 		if (m->m_pkthdr.len < sizeof(struct ip6_hdr))
288 			return 0;
289 		if (sc->gif_psrc->sa_family != AF_INET6 ||
290 		    sc->gif_pdst->sa_family != AF_INET6)
291 			return 0;
292 		return gif_encapcheck6(m, off, proto, arg);
293 #endif
294 	default:
295 		return 0;
296 	}
297 }
298 
299 int
300 gif_output(ifp, m, dst, rt)
301 	struct ifnet *ifp;
302 	struct mbuf *m;
303 	struct sockaddr *dst;
304 	struct rtentry *rt;	/* added in net2 */
305 {
306 	struct gif_softc *sc = (struct gif_softc*)ifp;
307 	int error = 0;
308 	static int called = 0;	/* XXX: MUTEX */
309 
310 	/*
311 	 * gif may cause infinite recursion calls when misconfigured.
312 	 * We'll prevent this by introducing upper limit.
313 	 * XXX: this mechanism may introduce another problem about
314 	 *      mutual exclusion of the variable CALLED, especially if we
315 	 *      use kernel thread.
316 	 */
317 	if (++called > max_gif_nesting) {
318 		log(LOG_NOTICE,
319 		    "gif_output: recursively called too many times(%d)\n",
320 		    called);
321 		m_freem(m);
322 		error = EIO;	/* is there better errno? */
323 		goto end;
324 	}
325 
326 	m->m_flags &= ~(M_BCAST|M_MCAST);
327 	if (!(ifp->if_flags & IFF_UP) ||
328 	    sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
329 		m_freem(m);
330 		error = ENETDOWN;
331 		goto end;
332 	}
333 
334 	if (ifp->if_bpf) {
335 		/*
336 		 * We need to prepend the address family as
337 		 * a four byte field.
338 		 */
339 		uint32_t af = dst->sa_family;
340 
341 		bpf_ptap(ifp->if_bpf, m, &af, sizeof(4));
342 	}
343 	ifp->if_opackets++;
344 	ifp->if_obytes += m->m_pkthdr.len;
345 
346 	/* inner AF-specific encapsulation */
347 
348 	/* XXX should we check if our outer source is legal? */
349 
350 	/* dispatch to output logic based on outer AF */
351 	switch (sc->gif_psrc->sa_family) {
352 #ifdef INET
353 	case AF_INET:
354 		error = in_gif_output(ifp, dst->sa_family, m);
355 		break;
356 #endif
357 #ifdef INET6
358 	case AF_INET6:
359 		error = in6_gif_output(ifp, dst->sa_family, m);
360 		break;
361 #endif
362 	default:
363 		m_freem(m);
364 		error = ENETDOWN;
365 		goto end;
366 	}
367 
368   end:
369 	called = 0;		/* reset recursion counter */
370 	if (error)
371 		ifp->if_oerrors++;
372 	return error;
373 }
374 
375 void
376 gif_input(m, af, ifp)
377 	struct mbuf *m;
378 	int af;
379 	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(ifp, cmd, data, cr)
438 	struct ifnet *ifp;
439 	u_long cmd;
440 	caddr_t data;
441 	struct ucred *cr;
442 {
443 	struct gif_softc *sc  = (struct gif_softc*)ifp;
444 	struct ifreq     *ifr = (struct ifreq*)data;
445 	int error = 0, size;
446 	struct sockaddr *dst, *src;
447 #ifdef	SIOCSIFMTU /* xxx */
448 	u_long mtu;
449 #endif
450 
451 	switch (cmd) {
452 	case SIOCSIFADDR:
453 		ifp->if_flags |= IFF_UP;
454 		break;
455 
456 	case SIOCSIFDSTADDR:
457 		break;
458 
459 	case SIOCADDMULTI:
460 	case SIOCDELMULTI:
461 		break;
462 
463 #ifdef	SIOCSIFMTU /* xxx */
464 	case SIOCGIFMTU:
465 		break;
466 
467 	case SIOCSIFMTU:
468 		mtu = ifr->ifr_mtu;
469 		if (mtu < GIF_MTU_MIN || mtu > GIF_MTU_MAX)
470 			return (EINVAL);
471 		ifp->if_mtu = mtu;
472 		break;
473 #endif /* SIOCSIFMTU */
474 
475 #ifdef INET
476 	case SIOCSIFPHYADDR:
477 #endif
478 #ifdef INET6
479 	case SIOCSIFPHYADDR_IN6:
480 #endif /* INET6 */
481 	case SIOCSLIFPHYADDR:
482 		switch (cmd) {
483 #ifdef INET
484 		case SIOCSIFPHYADDR:
485 			src = (struct sockaddr *)
486 				&(((struct in_aliasreq *)data)->ifra_addr);
487 			dst = (struct sockaddr *)
488 				&(((struct in_aliasreq *)data)->ifra_dstaddr);
489 			break;
490 #endif
491 #ifdef INET6
492 		case SIOCSIFPHYADDR_IN6:
493 			src = (struct sockaddr *)
494 				&(((struct in6_aliasreq *)data)->ifra_addr);
495 			dst = (struct sockaddr *)
496 				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
497 			break;
498 #endif
499 		case SIOCSLIFPHYADDR:
500 			src = (struct sockaddr *)
501 				&(((struct if_laddrreq *)data)->addr);
502 			dst = (struct sockaddr *)
503 				&(((struct if_laddrreq *)data)->dstaddr);
504 			break;
505 		default:
506 			return EINVAL;
507 		}
508 
509 		/* sa_family must be equal */
510 		if (src->sa_family != dst->sa_family)
511 			return EINVAL;
512 
513 		/* validate sa_len */
514 		switch (src->sa_family) {
515 #ifdef INET
516 		case AF_INET:
517 			if (src->sa_len != sizeof(struct sockaddr_in))
518 				return EINVAL;
519 			break;
520 #endif
521 #ifdef INET6
522 		case AF_INET6:
523 			if (src->sa_len != sizeof(struct sockaddr_in6))
524 				return EINVAL;
525 			break;
526 #endif
527 		default:
528 			return EAFNOSUPPORT;
529 		}
530 		switch (dst->sa_family) {
531 #ifdef INET
532 		case AF_INET:
533 			if (dst->sa_len != sizeof(struct sockaddr_in))
534 				return EINVAL;
535 			break;
536 #endif
537 #ifdef INET6
538 		case AF_INET6:
539 			if (dst->sa_len != sizeof(struct sockaddr_in6))
540 				return EINVAL;
541 			break;
542 #endif
543 		default:
544 			return EAFNOSUPPORT;
545 		}
546 
547 		/* check sa_family looks sane for the cmd */
548 		switch (cmd) {
549 		case SIOCSIFPHYADDR:
550 			if (src->sa_family == AF_INET)
551 				break;
552 			return EAFNOSUPPORT;
553 #ifdef INET6
554 		case SIOCSIFPHYADDR_IN6:
555 			if (src->sa_family == AF_INET6)
556 				break;
557 			return EAFNOSUPPORT;
558 #endif /* INET6 */
559 		case SIOCSLIFPHYADDR:
560 			/* checks done in the above */
561 			break;
562 		}
563 
564 		error = gif_set_tunnel(&sc->gif_if, src, dst);
565 		break;
566 
567 #ifdef SIOCDIFPHYADDR
568 	case SIOCDIFPHYADDR:
569 		gif_delete_tunnel(&sc->gif_if);
570 		break;
571 #endif
572 
573 	case SIOCGIFPSRCADDR:
574 #ifdef INET6
575 	case SIOCGIFPSRCADDR_IN6:
576 #endif /* INET6 */
577 		if (sc->gif_psrc == NULL) {
578 			error = EADDRNOTAVAIL;
579 			goto bad;
580 		}
581 		src = sc->gif_psrc;
582 		switch (cmd) {
583 #ifdef INET
584 		case SIOCGIFPSRCADDR:
585 			dst = &ifr->ifr_addr;
586 			size = sizeof(ifr->ifr_addr);
587 			break;
588 #endif /* INET */
589 #ifdef INET6
590 		case SIOCGIFPSRCADDR_IN6:
591 			dst = (struct sockaddr *)
592 				&(((struct in6_ifreq *)data)->ifr_addr);
593 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
594 			break;
595 #endif /* INET6 */
596 		default:
597 			error = EADDRNOTAVAIL;
598 			goto bad;
599 		}
600 		if (src->sa_len > size)
601 			return EINVAL;
602 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
603 		break;
604 
605 	case SIOCGIFPDSTADDR:
606 #ifdef INET6
607 	case SIOCGIFPDSTADDR_IN6:
608 #endif /* INET6 */
609 		if (sc->gif_pdst == NULL) {
610 			error = EADDRNOTAVAIL;
611 			goto bad;
612 		}
613 		src = sc->gif_pdst;
614 		switch (cmd) {
615 #ifdef INET
616 		case SIOCGIFPDSTADDR:
617 			dst = &ifr->ifr_addr;
618 			size = sizeof(ifr->ifr_addr);
619 			break;
620 #endif /* INET */
621 #ifdef INET6
622 		case SIOCGIFPDSTADDR_IN6:
623 			dst = (struct sockaddr *)
624 				&(((struct in6_ifreq *)data)->ifr_addr);
625 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
626 			break;
627 #endif /* INET6 */
628 		default:
629 			error = EADDRNOTAVAIL;
630 			goto bad;
631 		}
632 		if (src->sa_len > size)
633 			return EINVAL;
634 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
635 		break;
636 
637 	case SIOCGLIFPHYADDR:
638 		if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
639 			error = EADDRNOTAVAIL;
640 			goto bad;
641 		}
642 
643 		/* copy src */
644 		src = sc->gif_psrc;
645 		dst = (struct sockaddr *)
646 			&(((struct if_laddrreq *)data)->addr);
647 		size = sizeof(((struct if_laddrreq *)data)->addr);
648 		if (src->sa_len > size)
649 			return EINVAL;
650 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
651 
652 		/* copy dst */
653 		src = sc->gif_pdst;
654 		dst = (struct sockaddr *)
655 			&(((struct if_laddrreq *)data)->dstaddr);
656 		size = sizeof(((struct if_laddrreq *)data)->dstaddr);
657 		if (src->sa_len > size)
658 			return EINVAL;
659 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
660 		break;
661 
662 	case SIOCSIFFLAGS:
663 		/* if_ioctl() takes care of it */
664 		break;
665 
666 	default:
667 		error = EINVAL;
668 		break;
669 	}
670  bad:
671 	return error;
672 }
673 
674 int
675 gif_set_tunnel(ifp, src, dst)
676 	struct ifnet *ifp;
677 	struct sockaddr *src;
678 	struct sockaddr *dst;
679 {
680 	struct gif_softc *sc = (struct gif_softc *)ifp;
681 	struct gif_softc *sc2;
682 	struct sockaddr *osrc, *odst, *sa;
683 	int error = 0;
684 
685 	crit_enter();
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 	crit_exit();
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 	crit_exit();
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 
787 	crit_enter();
788 
789 	if (sc->gif_psrc) {
790 		free((caddr_t)sc->gif_psrc, M_IFADDR);
791 		sc->gif_psrc = NULL;
792 	}
793 	if (sc->gif_pdst) {
794 		free((caddr_t)sc->gif_pdst, M_IFADDR);
795 		sc->gif_pdst = NULL;
796 	}
797 	/* it is safe to detach from both */
798 #ifdef INET
799 	(void)in_gif_detach(sc);
800 #endif
801 #ifdef INET6
802 	(void)in6_gif_detach(sc);
803 #endif
804 
805 	if (sc->gif_psrc && sc->gif_pdst)
806 		ifp->if_flags |= IFF_RUNNING;
807 	else
808 		ifp->if_flags &= ~IFF_RUNNING;
809 	crit_exit();
810 }
811