xref: /dragonfly/sys/net/gif/if_gif.c (revision 7b0266d8) 
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 1.9 2004/03/23 22:19:06 hsu 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 #include <netinet/ipprotosw.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.  Cons up a dummy header
338 		 * to pacify bpf.  This is safe because bpf
339 		 * will only read from the mbuf (i.e., it won't
340 		 * try to free it or keep a pointer a to it).
341 		 */
342 		struct mbuf m0;
343 		u_int32_t af = dst->sa_family;
344 
345 		m0.m_next = m;
346 		m0.m_len = 4;
347 		m0.m_data = (char *)&af;
348 
349 		bpf_mtap(ifp, &m0);
350 	}
351 	ifp->if_opackets++;
352 	ifp->if_obytes += m->m_pkthdr.len;
353 
354 	/* inner AF-specific encapsulation */
355 
356 	/* XXX should we check if our outer source is legal? */
357 
358 	/* dispatch to output logic based on outer AF */
359 	switch (sc->gif_psrc->sa_family) {
360 #ifdef INET
361 	case AF_INET:
362 		error = in_gif_output(ifp, dst->sa_family, m);
363 		break;
364 #endif
365 #ifdef INET6
366 	case AF_INET6:
367 		error = in6_gif_output(ifp, dst->sa_family, m);
368 		break;
369 #endif
370 	default:
371 		m_freem(m);
372 		error = ENETDOWN;
373 		goto end;
374 	}
375 
376   end:
377 	called = 0;		/* reset recursion counter */
378 	if (error)
379 		ifp->if_oerrors++;
380 	return error;
381 }
382 
383 void
384 gif_input(m, af, ifp)
385 	struct mbuf *m;
386 	int af;
387 	struct ifnet *ifp;
388 {
389 	int isr;
390 
391 	if (ifp == NULL) {
392 		/* just in case */
393 		m_freem(m);
394 		return;
395 	}
396 
397 	m->m_pkthdr.rcvif = ifp;
398 
399 	if (ifp->if_bpf) {
400 		/*
401 		 * We need to prepend the address family as
402 		 * a four byte field.  Cons up a dummy header
403 		 * to pacify bpf.  This is safe because bpf
404 		 * will only read from the mbuf (i.e., it won't
405 		 * try to free it or keep a pointer a to it).
406 		 */
407 		struct mbuf m0;
408 		u_int32_t af1 = af;
409 
410 		m0.m_next = m;
411 		m0.m_len = 4;
412 		m0.m_data = (char *)&af1;
413 
414 		bpf_mtap(ifp, &m0);
415 	}
416 
417 	/*
418 	 * Put the packet to the network layer input queue according to the
419 	 * specified address family.
420 	 * Note: older versions of gif_input directly called network layer
421 	 * input functions, e.g. ip6_input, here.  We changed the policy to
422 	 * prevent too many recursive calls of such input functions, which
423 	 * might cause kernel panic.  But the change may introduce another
424 	 * problem; if the input queue is full, packets are discarded.
425 	 * The kernel stack overflow really happened, and we believed
426 	 * queue-full rarely occurs, so we changed the policy.
427 	 */
428 	switch (af) {
429 #ifdef INET
430 	case AF_INET:
431 		isr = NETISR_IP;
432 		break;
433 #endif
434 #ifdef INET6
435 	case AF_INET6:
436 		isr = NETISR_IPV6;
437 		break;
438 #endif
439 	default:
440 		m_freem(m);
441 		return;
442 	}
443 
444 	ifp->if_ipackets++;
445 	ifp->if_ibytes += m->m_pkthdr.len;
446 	netisr_dispatch(isr, m);
447 
448 	return;
449 }
450 
451 /* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
452 int
453 gif_ioctl(ifp, cmd, data, cr)
454 	struct ifnet *ifp;
455 	u_long cmd;
456 	caddr_t data;
457 	struct ucred *cr;
458 {
459 	struct gif_softc *sc  = (struct gif_softc*)ifp;
460 	struct ifreq     *ifr = (struct ifreq*)data;
461 	int error = 0, size;
462 	struct sockaddr *dst, *src;
463 #ifdef	SIOCSIFMTU /* xxx */
464 	u_long mtu;
465 #endif
466 
467 	switch (cmd) {
468 	case SIOCSIFADDR:
469 		ifp->if_flags |= IFF_UP;
470 		break;
471 
472 	case SIOCSIFDSTADDR:
473 		break;
474 
475 	case SIOCADDMULTI:
476 	case SIOCDELMULTI:
477 		break;
478 
479 #ifdef	SIOCSIFMTU /* xxx */
480 	case SIOCGIFMTU:
481 		break;
482 
483 	case SIOCSIFMTU:
484 		mtu = ifr->ifr_mtu;
485 		if (mtu < GIF_MTU_MIN || mtu > GIF_MTU_MAX)
486 			return (EINVAL);
487 		ifp->if_mtu = mtu;
488 		break;
489 #endif /* SIOCSIFMTU */
490 
491 #ifdef INET
492 	case SIOCSIFPHYADDR:
493 #endif
494 #ifdef INET6
495 	case SIOCSIFPHYADDR_IN6:
496 #endif /* INET6 */
497 	case SIOCSLIFPHYADDR:
498 		switch (cmd) {
499 #ifdef INET
500 		case SIOCSIFPHYADDR:
501 			src = (struct sockaddr *)
502 				&(((struct in_aliasreq *)data)->ifra_addr);
503 			dst = (struct sockaddr *)
504 				&(((struct in_aliasreq *)data)->ifra_dstaddr);
505 			break;
506 #endif
507 #ifdef INET6
508 		case SIOCSIFPHYADDR_IN6:
509 			src = (struct sockaddr *)
510 				&(((struct in6_aliasreq *)data)->ifra_addr);
511 			dst = (struct sockaddr *)
512 				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
513 			break;
514 #endif
515 		case SIOCSLIFPHYADDR:
516 			src = (struct sockaddr *)
517 				&(((struct if_laddrreq *)data)->addr);
518 			dst = (struct sockaddr *)
519 				&(((struct if_laddrreq *)data)->dstaddr);
520 			break;
521 		default:
522 			return EINVAL;
523 		}
524 
525 		/* sa_family must be equal */
526 		if (src->sa_family != dst->sa_family)
527 			return EINVAL;
528 
529 		/* validate sa_len */
530 		switch (src->sa_family) {
531 #ifdef INET
532 		case AF_INET:
533 			if (src->sa_len != sizeof(struct sockaddr_in))
534 				return EINVAL;
535 			break;
536 #endif
537 #ifdef INET6
538 		case AF_INET6:
539 			if (src->sa_len != sizeof(struct sockaddr_in6))
540 				return EINVAL;
541 			break;
542 #endif
543 		default:
544 			return EAFNOSUPPORT;
545 		}
546 		switch (dst->sa_family) {
547 #ifdef INET
548 		case AF_INET:
549 			if (dst->sa_len != sizeof(struct sockaddr_in))
550 				return EINVAL;
551 			break;
552 #endif
553 #ifdef INET6
554 		case AF_INET6:
555 			if (dst->sa_len != sizeof(struct sockaddr_in6))
556 				return EINVAL;
557 			break;
558 #endif
559 		default:
560 			return EAFNOSUPPORT;
561 		}
562 
563 		/* check sa_family looks sane for the cmd */
564 		switch (cmd) {
565 		case SIOCSIFPHYADDR:
566 			if (src->sa_family == AF_INET)
567 				break;
568 			return EAFNOSUPPORT;
569 #ifdef INET6
570 		case SIOCSIFPHYADDR_IN6:
571 			if (src->sa_family == AF_INET6)
572 				break;
573 			return EAFNOSUPPORT;
574 #endif /* INET6 */
575 		case SIOCSLIFPHYADDR:
576 			/* checks done in the above */
577 			break;
578 		}
579 
580 		error = gif_set_tunnel(&sc->gif_if, src, dst);
581 		break;
582 
583 #ifdef SIOCDIFPHYADDR
584 	case SIOCDIFPHYADDR:
585 		gif_delete_tunnel(&sc->gif_if);
586 		break;
587 #endif
588 
589 	case SIOCGIFPSRCADDR:
590 #ifdef INET6
591 	case SIOCGIFPSRCADDR_IN6:
592 #endif /* INET6 */
593 		if (sc->gif_psrc == NULL) {
594 			error = EADDRNOTAVAIL;
595 			goto bad;
596 		}
597 		src = sc->gif_psrc;
598 		switch (cmd) {
599 #ifdef INET
600 		case SIOCGIFPSRCADDR:
601 			dst = &ifr->ifr_addr;
602 			size = sizeof(ifr->ifr_addr);
603 			break;
604 #endif /* INET */
605 #ifdef INET6
606 		case SIOCGIFPSRCADDR_IN6:
607 			dst = (struct sockaddr *)
608 				&(((struct in6_ifreq *)data)->ifr_addr);
609 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
610 			break;
611 #endif /* INET6 */
612 		default:
613 			error = EADDRNOTAVAIL;
614 			goto bad;
615 		}
616 		if (src->sa_len > size)
617 			return EINVAL;
618 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
619 		break;
620 
621 	case SIOCGIFPDSTADDR:
622 #ifdef INET6
623 	case SIOCGIFPDSTADDR_IN6:
624 #endif /* INET6 */
625 		if (sc->gif_pdst == NULL) {
626 			error = EADDRNOTAVAIL;
627 			goto bad;
628 		}
629 		src = sc->gif_pdst;
630 		switch (cmd) {
631 #ifdef INET
632 		case SIOCGIFPDSTADDR:
633 			dst = &ifr->ifr_addr;
634 			size = sizeof(ifr->ifr_addr);
635 			break;
636 #endif /* INET */
637 #ifdef INET6
638 		case SIOCGIFPDSTADDR_IN6:
639 			dst = (struct sockaddr *)
640 				&(((struct in6_ifreq *)data)->ifr_addr);
641 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
642 			break;
643 #endif /* INET6 */
644 		default:
645 			error = EADDRNOTAVAIL;
646 			goto bad;
647 		}
648 		if (src->sa_len > size)
649 			return EINVAL;
650 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
651 		break;
652 
653 	case SIOCGLIFPHYADDR:
654 		if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
655 			error = EADDRNOTAVAIL;
656 			goto bad;
657 		}
658 
659 		/* copy src */
660 		src = sc->gif_psrc;
661 		dst = (struct sockaddr *)
662 			&(((struct if_laddrreq *)data)->addr);
663 		size = sizeof(((struct if_laddrreq *)data)->addr);
664 		if (src->sa_len > size)
665 			return EINVAL;
666 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
667 
668 		/* copy dst */
669 		src = sc->gif_pdst;
670 		dst = (struct sockaddr *)
671 			&(((struct if_laddrreq *)data)->dstaddr);
672 		size = sizeof(((struct if_laddrreq *)data)->dstaddr);
673 		if (src->sa_len > size)
674 			return EINVAL;
675 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
676 		break;
677 
678 	case SIOCSIFFLAGS:
679 		/* if_ioctl() takes care of it */
680 		break;
681 
682 	default:
683 		error = EINVAL;
684 		break;
685 	}
686  bad:
687 	return error;
688 }
689 
690 int
691 gif_set_tunnel(ifp, src, dst)
692 	struct ifnet *ifp;
693 	struct sockaddr *src;
694 	struct sockaddr *dst;
695 {
696 	struct gif_softc *sc = (struct gif_softc *)ifp;
697 	struct gif_softc *sc2;
698 	struct sockaddr *osrc, *odst, *sa;
699 	int s;
700 	int error = 0;
701 
702 	s = splnet();
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 			(void)in_gif_detach(sc);
735 			break;
736 #endif
737 #ifdef INET6
738 		case AF_INET6:
739 			(void)in6_gif_detach(sc);
740 			break;
741 #endif
742 		}
743 
744 	osrc = sc->gif_psrc;
745 	sa = (struct sockaddr *)malloc(src->sa_len, M_IFADDR, M_WAITOK);
746 	bcopy((caddr_t)src, (caddr_t)sa, src->sa_len);
747 	sc->gif_psrc = sa;
748 
749 	odst = sc->gif_pdst;
750 	sa = (struct sockaddr *)malloc(dst->sa_len, M_IFADDR, M_WAITOK);
751 	bcopy((caddr_t)dst, (caddr_t)sa, dst->sa_len);
752 	sc->gif_pdst = sa;
753 
754 	switch (sc->gif_psrc->sa_family) {
755 #ifdef INET
756 	case AF_INET:
757 		error = in_gif_attach(sc);
758 		break;
759 #endif
760 #ifdef INET6
761 	case AF_INET6:
762 		error = in6_gif_attach(sc);
763 		break;
764 #endif
765 	}
766 	if (error) {
767 		/* rollback */
768 		free((caddr_t)sc->gif_psrc, M_IFADDR);
769 		free((caddr_t)sc->gif_pdst, M_IFADDR);
770 		sc->gif_psrc = osrc;
771 		sc->gif_pdst = odst;
772 		goto bad;
773 	}
774 
775 	if (osrc)
776 		free((caddr_t)osrc, M_IFADDR);
777 	if (odst)
778 		free((caddr_t)odst, M_IFADDR);
779 
780 	if (sc->gif_psrc && sc->gif_pdst)
781 		ifp->if_flags |= IFF_RUNNING;
782 	else
783 		ifp->if_flags &= ~IFF_RUNNING;
784 	splx(s);
785 
786 	return 0;
787 
788  bad:
789 	if (sc->gif_psrc && sc->gif_pdst)
790 		ifp->if_flags |= IFF_RUNNING;
791 	else
792 		ifp->if_flags &= ~IFF_RUNNING;
793 	splx(s);
794 
795 	return error;
796 }
797 
798 void
799 gif_delete_tunnel(ifp)
800 	struct ifnet *ifp;
801 {
802 	struct gif_softc *sc = (struct gif_softc *)ifp;
803 	int s;
804 
805 	s = splnet();
806 
807 	if (sc->gif_psrc) {
808 		free((caddr_t)sc->gif_psrc, M_IFADDR);
809 		sc->gif_psrc = NULL;
810 	}
811 	if (sc->gif_pdst) {
812 		free((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 	(void)in_gif_detach(sc);
818 #endif
819 #ifdef INET6
820 	(void)in6_gif_detach(sc);
821 #endif
822 
823 	if (sc->gif_psrc && sc->gif_pdst)
824 		ifp->if_flags |= IFF_RUNNING;
825 	else
826 		ifp->if_flags &= ~IFF_RUNNING;
827 	splx(s);
828 }
829