xref: /freebsd/sys/net/if_gif.c (revision 747ca5f52192617ade3a33956f61380c684b74b8) 
1 /*	$FreeBSD$	*/
2 /*	$KAME: if_gif.c,v 1.87 2001/10/19 08:50:27 itojun Exp $	*/
3 
4 /*
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include "opt_inet.h"
34 #include "opt_inet6.h"
35 #include "opt_mac.h"
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/mac.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 <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 <net/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 static LIST_HEAD(, gif_softc) gif_softc_list;
88 
89 void	(*ng_gif_input_p)(struct ifnet *ifp, struct mbuf **mp, int af);
90 void	(*ng_gif_input_orphan_p)(struct ifnet *ifp, struct mbuf *m, int af);
91 void	(*ng_gif_attach_p)(struct ifnet *ifp);
92 void	(*ng_gif_detach_p)(struct ifnet *ifp);
93 
94 int	gif_clone_create(struct if_clone *, int);
95 void	gif_clone_destroy(struct ifnet *);
96 
97 struct if_clone gif_cloner = IF_CLONE_INITIALIZER("gif",
98     gif_clone_create, gif_clone_destroy, 0, IF_MAXUNIT);
99 
100 static int gifmodevent(module_t, int, void *);
101 
102 SYSCTL_DECL(_net_link);
103 SYSCTL_NODE(_net_link, IFT_GIF, gif, CTLFLAG_RW, 0,
104     "Generic Tunnel Interface");
105 #ifndef MAX_GIF_NEST
106 /*
107  * This macro controls the default upper limitation on nesting of gif tunnels.
108  * Since, setting a large value to this macro with a careless configuration
109  * may introduce system crash, we don't allow any nestings by default.
110  * If you need to configure nested gif tunnels, you can define this macro
111  * in your kernel configuration file.  However, if you do so, please be
112  * careful to configure the tunnels so that it won't make a loop.
113  */
114 #define MAX_GIF_NEST 1
115 #endif
116 static int max_gif_nesting = MAX_GIF_NEST;
117 SYSCTL_INT(_net_link_gif, OID_AUTO, max_nesting, CTLFLAG_RW,
118     &max_gif_nesting, 0, "Max nested tunnels");
119 
120 /*
121  * By default, we disallow creation of multiple tunnels between the same
122  * pair of addresses.  Some applications require this functionality so
123  * we allow control over this check here.
124  */
125 #ifdef XBONEHACK
126 static int parallel_tunnels = 1;
127 #else
128 static int parallel_tunnels = 0;
129 #endif
130 SYSCTL_INT(_net_link_gif, OID_AUTO, parallel_tunnels, CTLFLAG_RW,
131     &parallel_tunnels, 0, "Allow parallel tunnels?");
132 
133 int
134 gif_clone_create(ifc, unit)
135 	struct if_clone *ifc;
136 	int unit;
137 {
138 	struct gif_softc *sc;
139 
140 	sc = malloc (sizeof(struct gif_softc), M_GIF, M_WAITOK);
141 	bzero(sc, sizeof(struct gif_softc));
142 
143 	sc->gif_if.if_softc = sc;
144 	if_initname(&sc->gif_if, ifc->ifc_name, unit);
145 
146 	gifattach0(sc);
147 
148 	LIST_INSERT_HEAD(&gif_softc_list, sc, gif_list);
149 	return (0);
150 }
151 
152 void
153 gifattach0(sc)
154 	struct gif_softc *sc;
155 {
156 
157 	sc->encap_cookie4 = sc->encap_cookie6 = NULL;
158 
159 	sc->gif_if.if_addrlen = 0;
160 	sc->gif_if.if_mtu    = GIF_MTU;
161 	sc->gif_if.if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
162 #if 0
163 	/* turn off ingress filter */
164 	sc->gif_if.if_flags  |= IFF_LINK2;
165 #endif
166 	sc->gif_if.if_ioctl  = gif_ioctl;
167 	sc->gif_if.if_output = gif_output;
168 	sc->gif_if.if_type   = IFT_GIF;
169 	sc->gif_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
170 	if_attach(&sc->gif_if);
171 	bpfattach(&sc->gif_if, DLT_NULL, sizeof(u_int));
172 	if (ng_gif_attach_p != NULL)
173 		(*ng_gif_attach_p)(&sc->gif_if);
174 }
175 
176 void
177 gif_clone_destroy(ifp)
178 	struct ifnet *ifp;
179 {
180 	int err;
181 	struct gif_softc *sc = ifp->if_softc;
182 
183 	gif_delete_tunnel(&sc->gif_if);
184 	LIST_REMOVE(sc, gif_list);
185 #ifdef INET6
186 	if (sc->encap_cookie6 != NULL) {
187 		err = encap_detach(sc->encap_cookie6);
188 		KASSERT(err == 0, ("Unexpected error detaching encap_cookie6"));
189 	}
190 #endif
191 #ifdef INET
192 	if (sc->encap_cookie4 != NULL) {
193 		err = encap_detach(sc->encap_cookie4);
194 		KASSERT(err == 0, ("Unexpected error detaching encap_cookie4"));
195 	}
196 #endif
197 
198 	if (ng_gif_detach_p != NULL)
199 		(*ng_gif_detach_p)(ifp);
200 	bpfdetach(ifp);
201 	if_detach(ifp);
202 
203 	free(sc, M_GIF);
204 }
205 
206 static int
207 gifmodevent(mod, type, data)
208 	module_t mod;
209 	int type;
210 	void *data;
211 {
212 
213 	switch (type) {
214 	case MOD_LOAD:
215 		LIST_INIT(&gif_softc_list);
216 		if_clone_attach(&gif_cloner);
217 
218 #ifdef INET6
219 		ip6_gif_hlim = GIF_HLIM;
220 #endif
221 
222 		break;
223 	case MOD_UNLOAD:
224 		if_clone_detach(&gif_cloner);
225 
226 		while (!LIST_EMPTY(&gif_softc_list))
227 			gif_clone_destroy(&LIST_FIRST(&gif_softc_list)->gif_if);
228 
229 #ifdef INET6
230 		ip6_gif_hlim = 0;
231 #endif
232 		break;
233 	}
234 	return 0;
235 }
236 
237 static moduledata_t gif_mod = {
238 	"if_gif",
239 	gifmodevent,
240 	0
241 };
242 
243 DECLARE_MODULE(if_gif, gif_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
244 MODULE_VERSION(if_gif, 1);
245 
246 int
247 gif_encapcheck(m, off, proto, arg)
248 	const struct mbuf *m;
249 	int off;
250 	int proto;
251 	void *arg;
252 {
253 	struct ip ip;
254 	struct gif_softc *sc;
255 
256 	sc = (struct gif_softc *)arg;
257 	if (sc == NULL)
258 		return 0;
259 
260 	if ((sc->gif_if.if_flags & IFF_UP) == 0)
261 		return 0;
262 
263 	/* no physical address */
264 	if (!sc->gif_psrc || !sc->gif_pdst)
265 		return 0;
266 
267 	switch (proto) {
268 #ifdef INET
269 	case IPPROTO_IPV4:
270 		break;
271 #endif
272 #ifdef INET6
273 	case IPPROTO_IPV6:
274 		break;
275 #endif
276 	default:
277 		return 0;
278 	}
279 
280 	/* Bail on short packets */
281 	if (m->m_pkthdr.len < sizeof(ip))
282 		return 0;
283 
284 	m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
285 
286 	switch (ip.ip_v) {
287 #ifdef INET
288 	case 4:
289 		if (sc->gif_psrc->sa_family != AF_INET ||
290 		    sc->gif_pdst->sa_family != AF_INET)
291 			return 0;
292 		return gif_encapcheck4(m, off, proto, arg);
293 #endif
294 #ifdef INET6
295 	case 6:
296 		if (m->m_pkthdr.len < sizeof(struct ip6_hdr))
297 			return 0;
298 		if (sc->gif_psrc->sa_family != AF_INET6 ||
299 		    sc->gif_pdst->sa_family != AF_INET6)
300 			return 0;
301 		return gif_encapcheck6(m, off, proto, arg);
302 #endif
303 	default:
304 		return 0;
305 	}
306 }
307 
308 int
309 gif_output(ifp, m, dst, rt)
310 	struct ifnet *ifp;
311 	struct mbuf *m;
312 	struct sockaddr *dst;
313 	struct rtentry *rt;	/* added in net2 */
314 {
315 	struct gif_softc *sc = (struct gif_softc*)ifp;
316 	int error = 0;
317 	static int called = 0;	/* XXX: MUTEX */
318 
319 #ifdef MAC
320 	error = mac_check_ifnet_transmit(ifp, m);
321 	if (error) {
322 		m_freem(m);
323 		goto end;
324 	}
325 #endif
326 
327 	/*
328 	 * gif may cause infinite recursion calls when misconfigured.
329 	 * We'll prevent this by introducing upper limit.
330 	 * XXX: this mechanism may introduce another problem about
331 	 *      mutual exclusion of the variable CALLED, especially if we
332 	 *      use kernel thread.
333 	 */
334 	if (++called > max_gif_nesting) {
335 		log(LOG_NOTICE,
336 		    "gif_output: recursively called too many times(%d)\n",
337 		    called);
338 		m_freem(m);
339 		error = EIO;	/* is there better errno? */
340 		goto end;
341 	}
342 
343 	m->m_flags &= ~(M_BCAST|M_MCAST);
344 	if (!(ifp->if_flags & IFF_UP) ||
345 	    sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
346 		m_freem(m);
347 		error = ENETDOWN;
348 		goto end;
349 	}
350 
351 	if (ifp->if_bpf) {
352 		u_int32_t af = dst->sa_family;
353 		bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
354 	}
355 	ifp->if_opackets++;
356 	ifp->if_obytes += m->m_pkthdr.len;
357 
358 	/* inner AF-specific encapsulation */
359 
360 	/* XXX should we check if our outer source is legal? */
361 
362 	/* dispatch to output logic based on outer AF */
363 	switch (sc->gif_psrc->sa_family) {
364 #ifdef INET
365 	case AF_INET:
366 		error = in_gif_output(ifp, dst->sa_family, m);
367 		break;
368 #endif
369 #ifdef INET6
370 	case AF_INET6:
371 		error = in6_gif_output(ifp, dst->sa_family, m);
372 		break;
373 #endif
374 	default:
375 		m_freem(m);
376 		error = ENETDOWN;
377 		goto end;
378 	}
379 
380   end:
381 	called = 0;		/* reset recursion counter */
382 	if (error)
383 		ifp->if_oerrors++;
384 	return error;
385 }
386 
387 void
388 gif_input(m, af, ifp)
389 	struct mbuf *m;
390 	int af;
391 	struct ifnet *ifp;
392 {
393 	int isr;
394 
395 	if (ifp == NULL) {
396 		/* just in case */
397 		m_freem(m);
398 		return;
399 	}
400 
401 	m->m_pkthdr.rcvif = ifp;
402 
403 #ifdef MAC
404 	mac_create_mbuf_from_ifnet(ifp, m);
405 #endif
406 
407 	if (ifp->if_bpf) {
408 		u_int32_t af1 = af;
409 		bpf_mtap2(ifp->if_bpf, &af1, sizeof(af1), m);
410 	}
411 
412 	if (ng_gif_input_p != NULL) {
413 		(*ng_gif_input_p)(ifp, &m, af);
414 		if (m == NULL)
415 			return;
416 	}
417 
418 	/*
419 	 * Put the packet to the network layer input queue according to the
420 	 * specified address family.
421 	 * Note: older versions of gif_input directly called network layer
422 	 * input functions, e.g. ip6_input, here.  We changed the policy to
423 	 * prevent too many recursive calls of such input functions, which
424 	 * might cause kernel panic.  But the change may introduce another
425 	 * problem; if the input queue is full, packets are discarded.
426 	 * The kernel stack overflow really happened, and we believed
427 	 * queue-full rarely occurs, so we changed the policy.
428 	 */
429 	switch (af) {
430 #ifdef INET
431 	case AF_INET:
432 		isr = NETISR_IP;
433 		break;
434 #endif
435 #ifdef INET6
436 	case AF_INET6:
437 		isr = NETISR_IPV6;
438 		break;
439 #endif
440 	default:
441 		if (ng_gif_input_orphan_p != NULL)
442 			(*ng_gif_input_orphan_p)(ifp, m, af);
443 		else
444 			m_freem(m);
445 		return;
446 	}
447 
448 	ifp->if_ipackets++;
449 	ifp->if_ibytes += m->m_pkthdr.len;
450 	netisr_dispatch(isr, m);
451 }
452 
453 /* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
454 int
455 gif_ioctl(ifp, cmd, data)
456 	struct ifnet *ifp;
457 	u_long cmd;
458 	caddr_t data;
459 {
460 	struct gif_softc *sc  = (struct gif_softc*)ifp;
461 	struct ifreq     *ifr = (struct ifreq*)data;
462 	int error = 0, size;
463 	struct sockaddr *dst, *src;
464 #ifdef	SIOCSIFMTU /* xxx */
465 	u_long mtu;
466 #endif
467 
468 	switch (cmd) {
469 	case SIOCSIFADDR:
470 		ifp->if_flags |= IFF_UP;
471 		break;
472 
473 	case SIOCSIFDSTADDR:
474 		break;
475 
476 	case SIOCADDMULTI:
477 	case SIOCDELMULTI:
478 		break;
479 
480 #ifdef	SIOCSIFMTU /* xxx */
481 	case SIOCGIFMTU:
482 		break;
483 
484 	case SIOCSIFMTU:
485 		mtu = ifr->ifr_mtu;
486 		if (mtu < GIF_MTU_MIN || mtu > GIF_MTU_MAX)
487 			return (EINVAL);
488 		ifp->if_mtu = mtu;
489 		break;
490 #endif /* SIOCSIFMTU */
491 
492 #ifdef INET
493 	case SIOCSIFPHYADDR:
494 #endif
495 #ifdef INET6
496 	case SIOCSIFPHYADDR_IN6:
497 #endif /* INET6 */
498 	case SIOCSLIFPHYADDR:
499 		switch (cmd) {
500 #ifdef INET
501 		case SIOCSIFPHYADDR:
502 			src = (struct sockaddr *)
503 				&(((struct in_aliasreq *)data)->ifra_addr);
504 			dst = (struct sockaddr *)
505 				&(((struct in_aliasreq *)data)->ifra_dstaddr);
506 			break;
507 #endif
508 #ifdef INET6
509 		case SIOCSIFPHYADDR_IN6:
510 			src = (struct sockaddr *)
511 				&(((struct in6_aliasreq *)data)->ifra_addr);
512 			dst = (struct sockaddr *)
513 				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
514 			break;
515 #endif
516 		case SIOCSLIFPHYADDR:
517 			src = (struct sockaddr *)
518 				&(((struct if_laddrreq *)data)->addr);
519 			dst = (struct sockaddr *)
520 				&(((struct if_laddrreq *)data)->dstaddr);
521 			break;
522 		default:
523 			return EINVAL;
524 		}
525 
526 		/* sa_family must be equal */
527 		if (src->sa_family != dst->sa_family)
528 			return EINVAL;
529 
530 		/* validate sa_len */
531 		switch (src->sa_family) {
532 #ifdef INET
533 		case AF_INET:
534 			if (src->sa_len != sizeof(struct sockaddr_in))
535 				return EINVAL;
536 			break;
537 #endif
538 #ifdef INET6
539 		case AF_INET6:
540 			if (src->sa_len != sizeof(struct sockaddr_in6))
541 				return EINVAL;
542 			break;
543 #endif
544 		default:
545 			return EAFNOSUPPORT;
546 		}
547 		switch (dst->sa_family) {
548 #ifdef INET
549 		case AF_INET:
550 			if (dst->sa_len != sizeof(struct sockaddr_in))
551 				return EINVAL;
552 			break;
553 #endif
554 #ifdef INET6
555 		case AF_INET6:
556 			if (dst->sa_len != sizeof(struct sockaddr_in6))
557 				return EINVAL;
558 			break;
559 #endif
560 		default:
561 			return EAFNOSUPPORT;
562 		}
563 
564 		/* check sa_family looks sane for the cmd */
565 		switch (cmd) {
566 		case SIOCSIFPHYADDR:
567 			if (src->sa_family == AF_INET)
568 				break;
569 			return EAFNOSUPPORT;
570 #ifdef INET6
571 		case SIOCSIFPHYADDR_IN6:
572 			if (src->sa_family == AF_INET6)
573 				break;
574 			return EAFNOSUPPORT;
575 #endif /* INET6 */
576 		case SIOCSLIFPHYADDR:
577 			/* checks done in the above */
578 			break;
579 		}
580 
581 		error = gif_set_tunnel(&sc->gif_if, src, dst);
582 		break;
583 
584 #ifdef SIOCDIFPHYADDR
585 	case SIOCDIFPHYADDR:
586 		gif_delete_tunnel(&sc->gif_if);
587 		break;
588 #endif
589 
590 	case SIOCGIFPSRCADDR:
591 #ifdef INET6
592 	case SIOCGIFPSRCADDR_IN6:
593 #endif /* INET6 */
594 		if (sc->gif_psrc == NULL) {
595 			error = EADDRNOTAVAIL;
596 			goto bad;
597 		}
598 		src = sc->gif_psrc;
599 		switch (cmd) {
600 #ifdef INET
601 		case SIOCGIFPSRCADDR:
602 			dst = &ifr->ifr_addr;
603 			size = sizeof(ifr->ifr_addr);
604 			break;
605 #endif /* INET */
606 #ifdef INET6
607 		case SIOCGIFPSRCADDR_IN6:
608 			dst = (struct sockaddr *)
609 				&(((struct in6_ifreq *)data)->ifr_addr);
610 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
611 			break;
612 #endif /* INET6 */
613 		default:
614 			error = EADDRNOTAVAIL;
615 			goto bad;
616 		}
617 		if (src->sa_len > size)
618 			return EINVAL;
619 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
620 		break;
621 
622 	case SIOCGIFPDSTADDR:
623 #ifdef INET6
624 	case SIOCGIFPDSTADDR_IN6:
625 #endif /* INET6 */
626 		if (sc->gif_pdst == NULL) {
627 			error = EADDRNOTAVAIL;
628 			goto bad;
629 		}
630 		src = sc->gif_pdst;
631 		switch (cmd) {
632 #ifdef INET
633 		case SIOCGIFPDSTADDR:
634 			dst = &ifr->ifr_addr;
635 			size = sizeof(ifr->ifr_addr);
636 			break;
637 #endif /* INET */
638 #ifdef INET6
639 		case SIOCGIFPDSTADDR_IN6:
640 			dst = (struct sockaddr *)
641 				&(((struct in6_ifreq *)data)->ifr_addr);
642 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
643 			break;
644 #endif /* INET6 */
645 		default:
646 			error = EADDRNOTAVAIL;
647 			goto bad;
648 		}
649 		if (src->sa_len > size)
650 			return EINVAL;
651 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
652 		break;
653 
654 	case SIOCGLIFPHYADDR:
655 		if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
656 			error = EADDRNOTAVAIL;
657 			goto bad;
658 		}
659 
660 		/* copy src */
661 		src = sc->gif_psrc;
662 		dst = (struct sockaddr *)
663 			&(((struct if_laddrreq *)data)->addr);
664 		size = sizeof(((struct if_laddrreq *)data)->addr);
665 		if (src->sa_len > size)
666 			return EINVAL;
667 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
668 
669 		/* copy dst */
670 		src = sc->gif_pdst;
671 		dst = (struct sockaddr *)
672 			&(((struct if_laddrreq *)data)->dstaddr);
673 		size = sizeof(((struct if_laddrreq *)data)->dstaddr);
674 		if (src->sa_len > size)
675 			return EINVAL;
676 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
677 		break;
678 
679 	case SIOCSIFFLAGS:
680 		/* if_ioctl() takes care of it */
681 		break;
682 
683 	default:
684 		error = EINVAL;
685 		break;
686 	}
687  bad:
688 	return error;
689 }
690 
691 int
692 gif_set_tunnel(ifp, src, dst)
693 	struct ifnet *ifp;
694 	struct sockaddr *src;
695 	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 s;
701 	int error = 0;
702 
703 	s = splnet();
704 
705 	LIST_FOREACH(sc2, &gif_softc_list, gif_list) {
706 		if (sc2 == sc)
707 			continue;
708 		if (!sc2->gif_pdst || !sc2->gif_psrc)
709 			continue;
710 		if (sc2->gif_pdst->sa_family != dst->sa_family ||
711 		    sc2->gif_pdst->sa_len != dst->sa_len ||
712 		    sc2->gif_psrc->sa_family != src->sa_family ||
713 		    sc2->gif_psrc->sa_len != src->sa_len)
714 			continue;
715 
716 		/*
717 		 * Disallow parallel tunnels unless instructed
718 		 * otherwise.
719 		 */
720 		if (!parallel_tunnels &&
721 		    bcmp(sc2->gif_pdst, dst, dst->sa_len) == 0 &&
722 		    bcmp(sc2->gif_psrc, src, src->sa_len) == 0) {
723 			error = EADDRNOTAVAIL;
724 			goto bad;
725 		}
726 
727 		/* XXX both end must be valid? (I mean, not 0.0.0.0) */
728 	}
729 
730 	/* XXX we can detach from both, but be polite just in case */
731 	if (sc->gif_psrc)
732 		switch (sc->gif_psrc->sa_family) {
733 #ifdef INET
734 		case AF_INET:
735 			(void)in_gif_detach(sc);
736 			break;
737 #endif
738 #ifdef INET6
739 		case AF_INET6:
740 			(void)in6_gif_detach(sc);
741 			break;
742 #endif
743 		}
744 
745 	osrc = sc->gif_psrc;
746 	sa = (struct sockaddr *)malloc(src->sa_len, M_IFADDR, M_WAITOK);
747 	bcopy((caddr_t)src, (caddr_t)sa, src->sa_len);
748 	sc->gif_psrc = sa;
749 
750 	odst = sc->gif_pdst;
751 	sa = (struct sockaddr *)malloc(dst->sa_len, M_IFADDR, M_WAITOK);
752 	bcopy((caddr_t)dst, (caddr_t)sa, dst->sa_len);
753 	sc->gif_pdst = sa;
754 
755 	switch (sc->gif_psrc->sa_family) {
756 #ifdef INET
757 	case AF_INET:
758 		error = in_gif_attach(sc);
759 		break;
760 #endif
761 #ifdef INET6
762 	case AF_INET6:
763 		error = in6_gif_attach(sc);
764 		break;
765 #endif
766 	}
767 	if (error) {
768 		/* rollback */
769 		free((caddr_t)sc->gif_psrc, M_IFADDR);
770 		free((caddr_t)sc->gif_pdst, M_IFADDR);
771 		sc->gif_psrc = osrc;
772 		sc->gif_pdst = odst;
773 		goto bad;
774 	}
775 
776 	if (osrc)
777 		free((caddr_t)osrc, M_IFADDR);
778 	if (odst)
779 		free((caddr_t)odst, M_IFADDR);
780 
781 	if (sc->gif_psrc && sc->gif_pdst)
782 		ifp->if_flags |= IFF_RUNNING;
783 	else
784 		ifp->if_flags &= ~IFF_RUNNING;
785 	splx(s);
786 
787 	return 0;
788 
789  bad:
790 	if (sc->gif_psrc && sc->gif_pdst)
791 		ifp->if_flags |= IFF_RUNNING;
792 	else
793 		ifp->if_flags &= ~IFF_RUNNING;
794 	splx(s);
795 
796 	return error;
797 }
798 
799 void
800 gif_delete_tunnel(ifp)
801 	struct ifnet *ifp;
802 {
803 	struct gif_softc *sc = (struct gif_softc *)ifp;
804 	int s;
805 
806 	s = splnet();
807 
808 	if (sc->gif_psrc) {
809 		free((caddr_t)sc->gif_psrc, M_IFADDR);
810 		sc->gif_psrc = NULL;
811 	}
812 	if (sc->gif_pdst) {
813 		free((caddr_t)sc->gif_pdst, M_IFADDR);
814 		sc->gif_pdst = NULL;
815 	}
816 	/* it is safe to detach from both */
817 #ifdef INET
818 	(void)in_gif_detach(sc);
819 #endif
820 #ifdef INET6
821 	(void)in6_gif_detach(sc);
822 #endif
823 
824 	if (sc->gif_psrc && sc->gif_pdst)
825 		ifp->if_flags |= IFF_RUNNING;
826 	else
827 		ifp->if_flags &= ~IFF_RUNNING;
828 	splx(s);
829 }
830