xref: /dragonfly/sys/net/gif/if_gif.c (revision 52f9f0d9) 
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 int	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 static void gif_clear_cache(struct gif_softc *sc);
100 
101 SYSCTL_DECL(_net_link);
102 SYSCTL_NODE(_net_link, IFT_GIF, gif, CTLFLAG_RW, 0,
103     "Generic Tunnel Interface");
104 #ifndef MAX_GIF_NEST
105 /*
106  * This macro controls the default upper limitation on nesting of gif tunnels.
107  * Since, setting a large value to this macro with a careless configuration
108  * may introduce system crash, we don't allow any nestings by default.
109  * If you need to configure nested gif tunnels, you can define this macro
110  * in your kernel configuration file.  However, if you do so, please be
111  * careful to configure the tunnels so that it won't make a loop.
112  */
113 #define MAX_GIF_NEST 1
114 #endif
115 static int max_gif_nesting = MAX_GIF_NEST;
116 SYSCTL_INT(_net_link_gif, OID_AUTO, max_nesting, CTLFLAG_RW,
117     &max_gif_nesting, 0, "Max nested tunnels");
118 
119 /*
120  * By default, we disallow creation of multiple tunnels between the same
121  * pair of addresses.  Some applications require this functionality so
122  * we allow control over this check here.
123  */
124 #ifdef XBONEHACK
125 static int parallel_tunnels = 1;
126 #else
127 static int parallel_tunnels = 0;
128 #endif
129 SYSCTL_INT(_net_link_gif, OID_AUTO, parallel_tunnels, CTLFLAG_RW,
130     &parallel_tunnels, 0, "Allow parallel tunnels?");
131 
132 int
133 gif_clone_create(struct if_clone *ifc, int unit, caddr_t params)
134 {
135 	struct gif_softc *sc;
136 
137 	sc = kmalloc (sizeof(struct gif_softc), M_GIF, M_WAITOK | M_ZERO);
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(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, NULL);
166 	bpfattach(&sc->gif_if, DLT_NULL, sizeof(u_int));
167 }
168 
169 int
170 gif_clone_destroy(struct ifnet *ifp)
171 {
172 	struct gif_softc *sc = ifp->if_softc;
173 	int err;
174 
175 	gif_delete_tunnel(&sc->gif_if);
176 	LIST_REMOVE(sc, gif_list);
177 #ifdef INET6
178 	if (sc->encap_cookie6 != NULL) {
179 		err = encap_detach(sc->encap_cookie6);
180 		KASSERT(err == 0, ("Unexpected error detaching encap_cookie6"));
181 	}
182 #endif
183 #ifdef INET
184 	if (sc->encap_cookie4 != NULL) {
185 		err = encap_detach(sc->encap_cookie4);
186 		KASSERT(err == 0, ("Unexpected error detaching encap_cookie4"));
187 	}
188 #endif
189 	gif_clear_cache(sc);
190 
191 	bpfdetach(ifp);
192 	if_detach(ifp);
193 
194 	kfree(sc, M_GIF);
195 
196 	return 0;
197 }
198 
199 static void
200 gif_clear_cache(struct gif_softc *sc)
201 {
202 	int n;
203 
204 	for (n = 0; n < ncpus; ++n) {
205 		if (sc->gif_ro[n].ro_rt) {
206 			RTFREE(sc->gif_ro[n].ro_rt);
207 			sc->gif_ro[n].ro_rt = NULL;
208 		}
209 #ifdef INET6
210 		if (sc->gif_ro6[n].ro_rt) {
211 			RTFREE(sc->gif_ro6[n].ro_rt);
212 			sc->gif_ro6[n].ro_rt = NULL;
213 		}
214 #endif
215 	}
216 }
217 
218 static int
219 gifmodevent(module_t mod, int type, void *data)
220 {
221 
222 	switch (type) {
223 	case MOD_LOAD:
224 		LIST_INIT(&gif_softc_list);
225 		if_clone_attach(&gif_cloner);
226 
227 #ifdef INET6
228 		ip6_gif_hlim = GIF_HLIM;
229 #endif
230 
231 		break;
232 	case MOD_UNLOAD:
233 		if_clone_detach(&gif_cloner);
234 
235 		while (!LIST_EMPTY(&gif_softc_list))
236 			gif_clone_destroy(&LIST_FIRST(&gif_softc_list)->gif_if);
237 
238 #ifdef INET6
239 		ip6_gif_hlim = 0;
240 #endif
241 		break;
242 	}
243 	return 0;
244 }
245 
246 static moduledata_t gif_mod = {
247 	"if_gif",
248 	gifmodevent,
249 	0
250 };
251 
252 DECLARE_MODULE(if_gif, gif_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
253 
254 int
255 gif_encapcheck(const struct mbuf *m, int off, int proto, void *arg)
256 {
257 	struct ip ip;
258 	struct gif_softc *sc;
259 
260 	sc = (struct gif_softc *)arg;
261 	if (sc == NULL)
262 		return 0;
263 
264 	if ((sc->gif_if.if_flags & IFF_UP) == 0)
265 		return 0;
266 
267 	/* no physical address */
268 	if (!sc->gif_psrc || !sc->gif_pdst)
269 		return 0;
270 
271 	switch (proto) {
272 #ifdef INET
273 	case IPPROTO_IPV4:
274 		break;
275 #endif
276 #ifdef INET6
277 	case IPPROTO_IPV6:
278 		break;
279 #endif
280 	default:
281 		return 0;
282 	}
283 
284 	/* Bail on short packets */
285 	if (m->m_pkthdr.len < sizeof(ip))
286 		return 0;
287 
288 	m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
289 
290 	switch (ip.ip_v) {
291 #ifdef INET
292 	case 4:
293 		if (sc->gif_psrc->sa_family != AF_INET ||
294 		    sc->gif_pdst->sa_family != AF_INET)
295 			return 0;
296 		return gif_encapcheck4(m, off, proto, arg);
297 #endif
298 #ifdef INET6
299 	case 6:
300 		if (m->m_pkthdr.len < sizeof(struct ip6_hdr))
301 			return 0;
302 		if (sc->gif_psrc->sa_family != AF_INET6 ||
303 		    sc->gif_pdst->sa_family != AF_INET6)
304 			return 0;
305 		return gif_encapcheck6(m, off, proto, arg);
306 #endif
307 	default:
308 		return 0;
309 	}
310 }
311 
312 /*
313  * Parameters:
314  *	rt:	added in net2
315  */
316 static int
317 gif_output_serialized(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
318 		      struct rtentry *rt)
319 {
320 	struct gif_softc *sc = (struct gif_softc*)ifp;
321 	int error = 0;
322 	static int called = 0;	/* XXX: MUTEX */
323 
324 	/*
325 	 * gif may cause infinite recursion calls when misconfigured.
326 	 * We'll prevent this by introducing upper limit.
327 	 * XXX: this mechanism may introduce another problem about
328 	 *      mutual exclusion of the variable CALLED, especially if we
329 	 *      use kernel thread.
330 	 */
331 	if (++called > max_gif_nesting) {
332 		log(LOG_NOTICE,
333 		    "gif_output: recursively called too many times(%d)\n",
334 		    called);
335 		m_freem(m);
336 		error = EIO;	/* is there better errno? */
337 		goto end;
338 	}
339 
340 	m->m_flags &= ~(M_BCAST|M_MCAST);
341 	if (!(ifp->if_flags & IFF_UP) ||
342 	    sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
343 		m_freem(m);
344 		error = ENETDOWN;
345 		goto end;
346 	}
347 
348 	if (ifp->if_bpf) {
349 		/*
350 		 * We need to prepend the address family as
351 		 * a four byte field.
352 		 */
353 		uint32_t af = dst->sa_family;
354 
355 		bpf_ptap(ifp->if_bpf, m, &af, sizeof(af));
356 	}
357 	ifp->if_opackets++;
358 	ifp->if_obytes += m->m_pkthdr.len;
359 
360 	/* inner AF-specific encapsulation */
361 
362 	/* XXX should we check if our outer source is legal? */
363 
364 	/* dispatch to output logic based on outer AF */
365 	switch (sc->gif_psrc->sa_family) {
366 #ifdef INET
367 	case AF_INET:
368 		error = in_gif_output(ifp, dst->sa_family, m);
369 		break;
370 #endif
371 #ifdef INET6
372 	case AF_INET6:
373 		error = in6_gif_output(ifp, dst->sa_family, m);
374 		break;
375 #endif
376 	default:
377 		m_freem(m);
378 		error = ENETDOWN;
379 		goto end;
380 	}
381 
382   end:
383 	called = 0;		/* reset recursion counter */
384 	if (error)
385 		ifp->if_oerrors++;
386 	return error;
387 }
388 
389 int
390 gif_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
391 	   struct rtentry *rt)
392 {
393 	int error;
394 
395 	ifnet_serialize_tx(ifp);
396 	error = gif_output_serialized(ifp, m, dst, rt);
397 	ifnet_deserialize_tx(ifp);
398 	return error;
399 }
400 
401 void
402 gif_input(struct mbuf *m, int af, struct ifnet *ifp)
403 {
404 	int isr;
405 
406 	if (ifp == NULL) {
407 		/* just in case */
408 		m_freem(m);
409 		return;
410 	}
411 
412 	m->m_pkthdr.rcvif = ifp;
413 
414 	if (ifp->if_bpf) {
415 		/*
416 		 * We need to prepend the address family as
417 		 * a four byte field.
418 		 */
419 		uint32_t af1 = af;
420 
421 		bpf_ptap(ifp->if_bpf, m, &af1, sizeof(af1));
422 	}
423 
424 	/*
425 	 * Put the packet to the network layer input queue according to the
426 	 * specified address family.
427 	 * Note: older versions of gif_input directly called network layer
428 	 * input functions, e.g. ip6_input, here.  We changed the policy to
429 	 * prevent too many recursive calls of such input functions, which
430 	 * might cause kernel panic.  But the change may introduce another
431 	 * problem; if the input queue is full, packets are discarded.
432 	 * The kernel stack overflow really happened, and we believed
433 	 * queue-full rarely occurs, so we changed the policy.
434 	 */
435 	switch (af) {
436 #ifdef INET
437 	case AF_INET:
438 		isr = NETISR_IP;
439 		break;
440 #endif
441 #ifdef INET6
442 	case AF_INET6:
443 		isr = NETISR_IPV6;
444 		break;
445 #endif
446 	default:
447 		m_freem(m);
448 		return;
449 	}
450 
451 	ifp->if_ipackets++;
452 	ifp->if_ibytes += m->m_pkthdr.len;
453 	m->m_flags &= ~M_HASH;
454 	netisr_queue(isr, m);
455 
456 	return;
457 }
458 
459 /* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
460 int
461 gif_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
462 {
463 	struct gif_softc *sc  = (struct gif_softc*)ifp;
464 	struct ifreq     *ifr = (struct ifreq*)data;
465 	int error = 0, size;
466 	struct sockaddr *dst, *src;
467 #ifdef	SIOCSIFMTU /* xxx */
468 	u_long mtu;
469 #endif
470 
471 	switch (cmd) {
472 	case SIOCSIFADDR:
473 		ifp->if_flags |= IFF_UP;
474 		break;
475 
476 	case SIOCSIFDSTADDR:
477 		break;
478 
479 	case SIOCADDMULTI:
480 	case SIOCDELMULTI:
481 		break;
482 
483 #ifdef	SIOCSIFMTU /* xxx */
484 	case SIOCGIFMTU:
485 		break;
486 
487 	case SIOCSIFMTU:
488 		mtu = ifr->ifr_mtu;
489 		if (mtu < GIF_MTU_MIN || mtu > GIF_MTU_MAX)
490 			return (EINVAL);
491 		ifp->if_mtu = mtu;
492 		break;
493 #endif /* SIOCSIFMTU */
494 
495 #ifdef INET
496 	case SIOCSIFPHYADDR:
497 #endif
498 #ifdef INET6
499 	case SIOCSIFPHYADDR_IN6:
500 #endif /* INET6 */
501 	case SIOCSLIFPHYADDR:
502 		switch (cmd) {
503 #ifdef INET
504 		case SIOCSIFPHYADDR:
505 			src = (struct sockaddr *)
506 				&(((struct in_aliasreq *)data)->ifra_addr);
507 			dst = (struct sockaddr *)
508 				&(((struct in_aliasreq *)data)->ifra_dstaddr);
509 			break;
510 #endif
511 #ifdef INET6
512 		case SIOCSIFPHYADDR_IN6:
513 			src = (struct sockaddr *)
514 				&(((struct in6_aliasreq *)data)->ifra_addr);
515 			dst = (struct sockaddr *)
516 				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
517 			break;
518 #endif
519 		case SIOCSLIFPHYADDR:
520 			src = (struct sockaddr *)
521 				&(((struct if_laddrreq *)data)->addr);
522 			dst = (struct sockaddr *)
523 				&(((struct if_laddrreq *)data)->dstaddr);
524 			break;
525 		default:
526 			return EINVAL;
527 		}
528 
529 		/* sa_family must be equal */
530 		if (src->sa_family != dst->sa_family)
531 			return EINVAL;
532 
533 		/* validate sa_len */
534 		switch (src->sa_family) {
535 #ifdef INET
536 		case AF_INET:
537 			if (src->sa_len != sizeof(struct sockaddr_in))
538 				return EINVAL;
539 			break;
540 #endif
541 #ifdef INET6
542 		case AF_INET6:
543 			if (src->sa_len != sizeof(struct sockaddr_in6))
544 				return EINVAL;
545 			break;
546 #endif
547 		default:
548 			return EAFNOSUPPORT;
549 		}
550 		switch (dst->sa_family) {
551 #ifdef INET
552 		case AF_INET:
553 			if (dst->sa_len != sizeof(struct sockaddr_in))
554 				return EINVAL;
555 			break;
556 #endif
557 #ifdef INET6
558 		case AF_INET6:
559 			if (dst->sa_len != sizeof(struct sockaddr_in6))
560 				return EINVAL;
561 			break;
562 #endif
563 		default:
564 			return EAFNOSUPPORT;
565 		}
566 
567 		/* check sa_family looks sane for the cmd */
568 		switch (cmd) {
569 		case SIOCSIFPHYADDR:
570 			if (src->sa_family == AF_INET)
571 				break;
572 			return EAFNOSUPPORT;
573 #ifdef INET6
574 		case SIOCSIFPHYADDR_IN6:
575 			if (src->sa_family == AF_INET6)
576 				break;
577 			return EAFNOSUPPORT;
578 #endif /* INET6 */
579 		case SIOCSLIFPHYADDR:
580 			/* checks done in the above */
581 			break;
582 		}
583 
584 		error = gif_set_tunnel(&sc->gif_if, src, dst);
585 		break;
586 
587 #ifdef SIOCDIFPHYADDR
588 	case SIOCDIFPHYADDR:
589 		gif_delete_tunnel(&sc->gif_if);
590 		break;
591 #endif
592 
593 	case SIOCGIFPSRCADDR:
594 #ifdef INET6
595 	case SIOCGIFPSRCADDR_IN6:
596 #endif /* INET6 */
597 		if (sc->gif_psrc == NULL) {
598 			error = EADDRNOTAVAIL;
599 			goto bad;
600 		}
601 		src = sc->gif_psrc;
602 		switch (cmd) {
603 #ifdef INET
604 		case SIOCGIFPSRCADDR:
605 			dst = &ifr->ifr_addr;
606 			size = sizeof(ifr->ifr_addr);
607 			break;
608 #endif /* INET */
609 #ifdef INET6
610 		case SIOCGIFPSRCADDR_IN6:
611 			dst = (struct sockaddr *)
612 				&(((struct in6_ifreq *)data)->ifr_addr);
613 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
614 			break;
615 #endif /* INET6 */
616 		default:
617 			error = EADDRNOTAVAIL;
618 			goto bad;
619 		}
620 		if (src->sa_len > size)
621 			return EINVAL;
622 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
623 		break;
624 
625 	case SIOCGIFPDSTADDR:
626 #ifdef INET6
627 	case SIOCGIFPDSTADDR_IN6:
628 #endif /* INET6 */
629 		if (sc->gif_pdst == NULL) {
630 			error = EADDRNOTAVAIL;
631 			goto bad;
632 		}
633 		src = sc->gif_pdst;
634 		switch (cmd) {
635 #ifdef INET
636 		case SIOCGIFPDSTADDR:
637 			dst = &ifr->ifr_addr;
638 			size = sizeof(ifr->ifr_addr);
639 			break;
640 #endif /* INET */
641 #ifdef INET6
642 		case SIOCGIFPDSTADDR_IN6:
643 			dst = (struct sockaddr *)
644 				&(((struct in6_ifreq *)data)->ifr_addr);
645 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
646 			break;
647 #endif /* INET6 */
648 		default:
649 			error = EADDRNOTAVAIL;
650 			goto bad;
651 		}
652 		if (src->sa_len > size)
653 			return EINVAL;
654 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
655 		break;
656 
657 	case SIOCGLIFPHYADDR:
658 		if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
659 			error = EADDRNOTAVAIL;
660 			goto bad;
661 		}
662 
663 		/* copy src */
664 		src = sc->gif_psrc;
665 		dst = (struct sockaddr *)
666 			&(((struct if_laddrreq *)data)->addr);
667 		size = sizeof(((struct if_laddrreq *)data)->addr);
668 		if (src->sa_len > size)
669 			return EINVAL;
670 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
671 
672 		/* copy dst */
673 		src = sc->gif_pdst;
674 		dst = (struct sockaddr *)
675 			&(((struct if_laddrreq *)data)->dstaddr);
676 		size = sizeof(((struct if_laddrreq *)data)->dstaddr);
677 		if (src->sa_len > size)
678 			return EINVAL;
679 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
680 		break;
681 
682 	case SIOCSIFFLAGS:
683 		/* if_ioctl() takes care of it */
684 		break;
685 
686 	default:
687 		error = EINVAL;
688 		break;
689 	}
690  bad:
691 	return error;
692 }
693 
694 int
695 gif_set_tunnel(struct ifnet *ifp, struct sockaddr *src, struct sockaddr *dst)
696 {
697 	struct gif_softc *sc = (struct gif_softc *)ifp;
698 	struct gif_softc *sc2;
699 	struct sockaddr *osrc, *odst, *sa;
700 	int error = 0;
701 
702 	crit_enter();
703 
704 	LIST_FOREACH(sc2, &gif_softc_list, gif_list) {
705 		if (sc2 == sc)
706 			continue;
707 		if (!sc2->gif_pdst || !sc2->gif_psrc)
708 			continue;
709 		if (sc2->gif_pdst->sa_family != dst->sa_family ||
710 		    sc2->gif_pdst->sa_len != dst->sa_len ||
711 		    sc2->gif_psrc->sa_family != src->sa_family ||
712 		    sc2->gif_psrc->sa_len != src->sa_len)
713 			continue;
714 
715 		/*
716 		 * Disallow parallel tunnels unless instructed
717 		 * otherwise.
718 		 */
719 		if (!parallel_tunnels &&
720 		    bcmp(sc2->gif_pdst, dst, dst->sa_len) == 0 &&
721 		    bcmp(sc2->gif_psrc, src, src->sa_len) == 0) {
722 			error = EADDRNOTAVAIL;
723 			goto bad;
724 		}
725 
726 		/* XXX both end must be valid? (I mean, not 0.0.0.0) */
727 	}
728 
729 	/* XXX we can detach from both, but be polite just in case */
730 	if (sc->gif_psrc) {
731 		switch (sc->gif_psrc->sa_family) {
732 #ifdef INET
733 		case AF_INET:
734 			in_gif_detach(sc);
735 			break;
736 #endif
737 #ifdef INET6
738 		case AF_INET6:
739 			in6_gif_detach(sc);
740 			break;
741 #endif
742 		}
743 		gif_clear_cache(sc);
744 	}
745 
746 	osrc = sc->gif_psrc;
747 	sa = (struct sockaddr *)kmalloc(src->sa_len, M_IFADDR, M_WAITOK);
748 	bcopy((caddr_t)src, (caddr_t)sa, src->sa_len);
749 	sc->gif_psrc = sa;
750 
751 	odst = sc->gif_pdst;
752 	sa = (struct sockaddr *)kmalloc(dst->sa_len, M_IFADDR, M_WAITOK);
753 	bcopy((caddr_t)dst, (caddr_t)sa, dst->sa_len);
754 	sc->gif_pdst = sa;
755 
756 	switch (sc->gif_psrc->sa_family) {
757 #ifdef INET
758 	case AF_INET:
759 		error = in_gif_attach(sc);
760 		break;
761 #endif
762 #ifdef INET6
763 	case AF_INET6:
764 		error = in6_gif_attach(sc);
765 		break;
766 #endif
767 	}
768 	if (error) {
769 		/* rollback */
770 		kfree((caddr_t)sc->gif_psrc, M_IFADDR);
771 		kfree((caddr_t)sc->gif_pdst, M_IFADDR);
772 		sc->gif_psrc = osrc;
773 		sc->gif_pdst = odst;
774 		goto bad;
775 	}
776 
777 	if (osrc)
778 		kfree((caddr_t)osrc, M_IFADDR);
779 	if (odst)
780 		kfree((caddr_t)odst, M_IFADDR);
781 
782 	if (sc->gif_psrc && sc->gif_pdst)
783 		ifp->if_flags |= IFF_RUNNING;
784 	else
785 		ifp->if_flags &= ~IFF_RUNNING;
786 	crit_exit();
787 
788 	return 0;
789 
790  bad:
791 	if (sc->gif_psrc && sc->gif_pdst)
792 		ifp->if_flags |= IFF_RUNNING;
793 	else
794 		ifp->if_flags &= ~IFF_RUNNING;
795 	crit_exit();
796 
797 	return error;
798 }
799 
800 void
801 gif_delete_tunnel(struct ifnet *ifp)
802 {
803 	struct gif_softc *sc = (struct gif_softc *)ifp;
804 
805 	crit_enter();
806 
807 	if (sc->gif_psrc) {
808 		kfree((caddr_t)sc->gif_psrc, M_IFADDR);
809 		sc->gif_psrc = NULL;
810 	}
811 	if (sc->gif_pdst) {
812 		kfree((caddr_t)sc->gif_pdst, M_IFADDR);
813 		sc->gif_pdst = NULL;
814 	}
815 	/* it is safe to detach from both */
816 #ifdef INET
817 	in_gif_detach(sc);
818 #endif
819 #ifdef INET6
820 	in6_gif_detach(sc);
821 #endif
822 	gif_clear_cache(sc);
823 
824 	if (sc->gif_psrc && sc->gif_pdst)
825 		ifp->if_flags |= IFF_RUNNING;
826 	else
827 		ifp->if_flags &= ~IFF_RUNNING;
828 	crit_exit();
829 }
830