xref: /freebsd/sys/net/if_gif.c (revision 06064893b3c62c648518be78604fac29fc0d9d61)
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/module.h>
44 #include <sys/socket.h>
45 #include <sys/sockio.h>
46 #include <sys/errno.h>
47 #include <sys/time.h>
48 #include <sys/sysctl.h>
49 #include <sys/syslog.h>
50 #include <sys/protosw.h>
51 #include <sys/conf.h>
52 #include <machine/cpu.h>
53 
54 #include <net/if.h>
55 #include <net/if_clone.h>
56 #include <net/if_types.h>
57 #include <net/netisr.h>
58 #include <net/route.h>
59 #include <net/bpf.h>
60 
61 #include <netinet/in.h>
62 #include <netinet/in_systm.h>
63 #include <netinet/ip.h>
64 #ifdef	INET
65 #include <netinet/in_var.h>
66 #include <netinet/in_gif.h>
67 #include <netinet/ip_var.h>
68 #endif	/* INET */
69 
70 #ifdef INET6
71 #ifndef INET
72 #include <netinet/in.h>
73 #endif
74 #include <netinet6/in6_var.h>
75 #include <netinet/ip6.h>
76 #include <netinet6/ip6_var.h>
77 #include <netinet6/in6_gif.h>
78 #include <netinet6/ip6protosw.h>
79 #endif /* INET6 */
80 
81 #include <netinet/ip_encap.h>
82 #include <net/if_gif.h>
83 
84 #include <net/net_osdep.h>
85 
86 #define GIFNAME		"gif"
87 
88 /*
89  * gif_mtx protects the global gif_softc_list.
90  * XXX: Per-softc locking is still required.
91  */
92 static struct mtx gif_mtx;
93 static MALLOC_DEFINE(M_GIF, "gif", "Generic Tunnel Interface");
94 static LIST_HEAD(, gif_softc) gif_softc_list;
95 
96 void	(*ng_gif_input_p)(struct ifnet *ifp, struct mbuf **mp, int af);
97 void	(*ng_gif_input_orphan_p)(struct ifnet *ifp, struct mbuf *m, int af);
98 void	(*ng_gif_attach_p)(struct ifnet *ifp);
99 void	(*ng_gif_detach_p)(struct ifnet *ifp);
100 
101 static int	gif_clone_create(struct if_clone *, int);
102 static void	gif_clone_destroy(struct ifnet *);
103 
104 IFC_SIMPLE_DECLARE(gif, 0);
105 
106 static int gifmodevent(module_t, int, void *);
107 
108 SYSCTL_DECL(_net_link);
109 SYSCTL_NODE(_net_link, IFT_GIF, gif, CTLFLAG_RW, 0,
110     "Generic Tunnel Interface");
111 #ifndef MAX_GIF_NEST
112 /*
113  * This macro controls the default upper limitation on nesting of gif tunnels.
114  * Since, setting a large value to this macro with a careless configuration
115  * may introduce system crash, we don't allow any nestings by default.
116  * If you need to configure nested gif tunnels, you can define this macro
117  * in your kernel configuration file.  However, if you do so, please be
118  * careful to configure the tunnels so that it won't make a loop.
119  */
120 #define MAX_GIF_NEST 1
121 #endif
122 static int max_gif_nesting = MAX_GIF_NEST;
123 SYSCTL_INT(_net_link_gif, OID_AUTO, max_nesting, CTLFLAG_RW,
124     &max_gif_nesting, 0, "Max nested tunnels");
125 
126 /*
127  * By default, we disallow creation of multiple tunnels between the same
128  * pair of addresses.  Some applications require this functionality so
129  * we allow control over this check here.
130  */
131 #ifdef XBONEHACK
132 static int parallel_tunnels = 1;
133 #else
134 static int parallel_tunnels = 0;
135 #endif
136 SYSCTL_INT(_net_link_gif, OID_AUTO, parallel_tunnels, CTLFLAG_RW,
137     &parallel_tunnels, 0, "Allow parallel tunnels?");
138 
139 static int
140 gif_clone_create(ifc, unit)
141 	struct if_clone *ifc;
142 	int unit;
143 {
144 	struct gif_softc *sc;
145 
146 	sc = malloc(sizeof(struct gif_softc), M_GIF, M_WAITOK | M_ZERO);
147 
148 	sc->gif_if.if_softc = sc;
149 	if_initname(&sc->gif_if, ifc->ifc_name, unit);
150 
151 	gifattach0(sc);
152 
153 	mtx_lock(&gif_mtx);
154 	LIST_INSERT_HEAD(&gif_softc_list, sc, gif_list);
155 	mtx_unlock(&gif_mtx);
156 	return (0);
157 }
158 
159 void
160 gifattach0(sc)
161 	struct gif_softc *sc;
162 {
163 
164 	sc->encap_cookie4 = sc->encap_cookie6 = NULL;
165 
166 	sc->gif_if.if_addrlen = 0;
167 	sc->gif_if.if_mtu    = GIF_MTU;
168 	sc->gif_if.if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
169 #if 0
170 	/* turn off ingress filter */
171 	sc->gif_if.if_flags  |= IFF_LINK2;
172 #endif
173 	sc->gif_if.if_ioctl  = gif_ioctl;
174 	sc->gif_if.if_output = gif_output;
175 	sc->gif_if.if_type   = IFT_GIF;
176 	sc->gif_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
177 	if_attach(&sc->gif_if);
178 	bpfattach(&sc->gif_if, DLT_NULL, sizeof(u_int));
179 	if (ng_gif_attach_p != NULL)
180 		(*ng_gif_attach_p)(&sc->gif_if);
181 }
182 
183 static void
184 gif_destroy(struct gif_softc *sc)
185 {
186 	struct ifnet *ifp = &sc->gif_if;
187 	int err;
188 
189 	gif_delete_tunnel(ifp);
190 #ifdef INET6
191 	if (sc->encap_cookie6 != NULL) {
192 		err = encap_detach(sc->encap_cookie6);
193 		KASSERT(err == 0, ("Unexpected error detaching encap_cookie6"));
194 	}
195 #endif
196 #ifdef INET
197 	if (sc->encap_cookie4 != NULL) {
198 		err = encap_detach(sc->encap_cookie4);
199 		KASSERT(err == 0, ("Unexpected error detaching encap_cookie4"));
200 	}
201 #endif
202 
203 	if (ng_gif_detach_p != NULL)
204 		(*ng_gif_detach_p)(ifp);
205 	bpfdetach(ifp);
206 	if_detach(ifp);
207 
208 	free(sc, M_GIF);
209 }
210 
211 static void
212 gif_clone_destroy(ifp)
213 	struct ifnet *ifp;
214 {
215 	struct gif_softc *sc = ifp->if_softc;
216 
217 	mtx_lock(&gif_mtx);
218 	LIST_REMOVE(sc, gif_list);
219 	mtx_unlock(&gif_mtx);
220 	gif_destroy(sc);
221 }
222 
223 static int
224 gifmodevent(mod, type, data)
225 	module_t mod;
226 	int type;
227 	void *data;
228 {
229 	struct gif_softc *sc;
230 
231 	switch (type) {
232 	case MOD_LOAD:
233 		mtx_init(&gif_mtx, "gif_mtx", NULL, MTX_DEF);
234 		LIST_INIT(&gif_softc_list);
235 		if_clone_attach(&gif_cloner);
236 
237 #ifdef INET6
238 		ip6_gif_hlim = GIF_HLIM;
239 #endif
240 
241 		break;
242 	case MOD_UNLOAD:
243 		if_clone_detach(&gif_cloner);
244 
245 		mtx_lock(&gif_mtx);
246 		while ((sc = LIST_FIRST(&gif_softc_list)) != NULL) {
247 			LIST_REMOVE(sc, gif_list);
248 			mtx_unlock(&gif_mtx);
249 			gif_destroy(sc);
250 			mtx_lock(&gif_mtx);
251 		}
252 		mtx_unlock(&gif_mtx);
253 		mtx_destroy(&gif_mtx);
254 #ifdef INET6
255 		ip6_gif_hlim = 0;
256 #endif
257 		break;
258 	default:
259 		return EOPNOTSUPP;
260 	}
261 	return 0;
262 }
263 
264 static moduledata_t gif_mod = {
265 	"if_gif",
266 	gifmodevent,
267 	0
268 };
269 
270 DECLARE_MODULE(if_gif, gif_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
271 MODULE_VERSION(if_gif, 1);
272 
273 int
274 gif_encapcheck(m, off, proto, arg)
275 	const struct mbuf *m;
276 	int off;
277 	int proto;
278 	void *arg;
279 {
280 	struct ip ip;
281 	struct gif_softc *sc;
282 
283 	sc = (struct gif_softc *)arg;
284 	if (sc == NULL)
285 		return 0;
286 
287 	if ((sc->gif_if.if_flags & IFF_UP) == 0)
288 		return 0;
289 
290 	/* no physical address */
291 	if (!sc->gif_psrc || !sc->gif_pdst)
292 		return 0;
293 
294 	switch (proto) {
295 #ifdef INET
296 	case IPPROTO_IPV4:
297 		break;
298 #endif
299 #ifdef INET6
300 	case IPPROTO_IPV6:
301 		break;
302 #endif
303 	default:
304 		return 0;
305 	}
306 
307 	/* Bail on short packets */
308 	if (m->m_pkthdr.len < sizeof(ip))
309 		return 0;
310 
311 	m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
312 
313 	switch (ip.ip_v) {
314 #ifdef INET
315 	case 4:
316 		if (sc->gif_psrc->sa_family != AF_INET ||
317 		    sc->gif_pdst->sa_family != AF_INET)
318 			return 0;
319 		return gif_encapcheck4(m, off, proto, arg);
320 #endif
321 #ifdef INET6
322 	case 6:
323 		if (m->m_pkthdr.len < sizeof(struct ip6_hdr))
324 			return 0;
325 		if (sc->gif_psrc->sa_family != AF_INET6 ||
326 		    sc->gif_pdst->sa_family != AF_INET6)
327 			return 0;
328 		return gif_encapcheck6(m, off, proto, arg);
329 #endif
330 	default:
331 		return 0;
332 	}
333 }
334 
335 int
336 gif_output(ifp, m, dst, rt)
337 	struct ifnet *ifp;
338 	struct mbuf *m;
339 	struct sockaddr *dst;
340 	struct rtentry *rt;	/* added in net2 */
341 {
342 	struct gif_softc *sc = (struct gif_softc*)ifp;
343 	struct m_tag *mtag;
344 	int error = 0;
345 	int gif_called;
346 
347 #ifdef MAC
348 	error = mac_check_ifnet_transmit(ifp, m);
349 	if (error) {
350 		m_freem(m);
351 		goto end;
352 	}
353 #endif
354 
355 	/*
356 	 * gif may cause infinite recursion calls when misconfigured.
357 	 * We'll prevent this by detecting loops.
358 	 *
359 	 * High nesting level may cause stack exhaustion.
360 	 * We'll prevent this by introducing upper limit.
361 	 */
362 	gif_called = 1;
363 	mtag = m_tag_locate(m, MTAG_GIF, MTAG_GIF_CALLED, NULL);
364 	while (mtag != NULL) {
365 		if (*(struct ifnet **)(mtag + 1) == ifp) {
366 			log(LOG_NOTICE,
367 			    "gif_output: loop detected on %s\n",
368 			    (*(struct ifnet **)(mtag + 1))->if_xname);
369 			m_freem(m);
370 			error = EIO;	/* is there better errno? */
371 			goto end;
372 		}
373 		mtag = m_tag_locate(m, MTAG_GIF, MTAG_GIF_CALLED, mtag);
374 		gif_called++;
375 	}
376 	if (gif_called > max_gif_nesting) {
377 		log(LOG_NOTICE,
378 		    "gif_output: recursively called too many times(%d)\n",
379 		    gif_called);
380 		m_freem(m);
381 		error = EIO;	/* is there better errno? */
382 		goto end;
383 	}
384 	mtag = m_tag_alloc(MTAG_GIF, MTAG_GIF_CALLED, sizeof(struct ifnet *),
385 	    M_NOWAIT);
386 	if (mtag == NULL) {
387 		m_freem(m);
388 		error = ENOMEM;
389 		goto end;
390 	}
391 	*(struct ifnet **)(mtag + 1) = ifp;
392 	m_tag_prepend(m, mtag);
393 
394 	m->m_flags &= ~(M_BCAST|M_MCAST);
395 	if (!(ifp->if_flags & IFF_UP) ||
396 	    sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
397 		m_freem(m);
398 		error = ENETDOWN;
399 		goto end;
400 	}
401 
402 	if (ifp->if_bpf) {
403 		u_int32_t af = dst->sa_family;
404 		bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
405 	}
406 	ifp->if_opackets++;
407 	ifp->if_obytes += m->m_pkthdr.len;
408 
409 	/* inner AF-specific encapsulation */
410 
411 	/* XXX should we check if our outer source is legal? */
412 
413 	/* dispatch to output logic based on outer AF */
414 	switch (sc->gif_psrc->sa_family) {
415 #ifdef INET
416 	case AF_INET:
417 		error = in_gif_output(ifp, dst->sa_family, m);
418 		break;
419 #endif
420 #ifdef INET6
421 	case AF_INET6:
422 		error = in6_gif_output(ifp, dst->sa_family, m);
423 		break;
424 #endif
425 	default:
426 		m_freem(m);
427 		error = ENETDOWN;
428 		goto end;
429 	}
430 
431   end:
432 	if (error)
433 		ifp->if_oerrors++;
434 	return error;
435 }
436 
437 void
438 gif_input(m, af, ifp)
439 	struct mbuf *m;
440 	int af;
441 	struct ifnet *ifp;
442 {
443 	int isr;
444 
445 	if (ifp == NULL) {
446 		/* just in case */
447 		m_freem(m);
448 		return;
449 	}
450 
451 	m->m_pkthdr.rcvif = ifp;
452 
453 #ifdef MAC
454 	mac_create_mbuf_from_ifnet(ifp, m);
455 #endif
456 
457 	if (ifp->if_bpf) {
458 		u_int32_t af1 = af;
459 		bpf_mtap2(ifp->if_bpf, &af1, sizeof(af1), m);
460 	}
461 
462 	if (ng_gif_input_p != NULL) {
463 		(*ng_gif_input_p)(ifp, &m, af);
464 		if (m == NULL)
465 			return;
466 	}
467 
468 	/*
469 	 * Put the packet to the network layer input queue according to the
470 	 * specified address family.
471 	 * Note: older versions of gif_input directly called network layer
472 	 * input functions, e.g. ip6_input, here.  We changed the policy to
473 	 * prevent too many recursive calls of such input functions, which
474 	 * might cause kernel panic.  But the change may introduce another
475 	 * problem; if the input queue is full, packets are discarded.
476 	 * The kernel stack overflow really happened, and we believed
477 	 * queue-full rarely occurs, so we changed the policy.
478 	 */
479 	switch (af) {
480 #ifdef INET
481 	case AF_INET:
482 		isr = NETISR_IP;
483 		break;
484 #endif
485 #ifdef INET6
486 	case AF_INET6:
487 		isr = NETISR_IPV6;
488 		break;
489 #endif
490 	default:
491 		if (ng_gif_input_orphan_p != NULL)
492 			(*ng_gif_input_orphan_p)(ifp, m, af);
493 		else
494 			m_freem(m);
495 		return;
496 	}
497 
498 	ifp->if_ipackets++;
499 	ifp->if_ibytes += m->m_pkthdr.len;
500 	netisr_dispatch(isr, m);
501 }
502 
503 /* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
504 int
505 gif_ioctl(ifp, cmd, data)
506 	struct ifnet *ifp;
507 	u_long cmd;
508 	caddr_t data;
509 {
510 	struct gif_softc *sc  = (struct gif_softc*)ifp;
511 	struct ifreq     *ifr = (struct ifreq*)data;
512 	int error = 0, size;
513 	struct sockaddr *dst, *src;
514 #ifdef	SIOCSIFMTU /* xxx */
515 	u_long mtu;
516 #endif
517 
518 	switch (cmd) {
519 	case SIOCSIFADDR:
520 		ifp->if_flags |= IFF_UP;
521 		break;
522 
523 	case SIOCSIFDSTADDR:
524 		break;
525 
526 	case SIOCADDMULTI:
527 	case SIOCDELMULTI:
528 		break;
529 
530 #ifdef	SIOCSIFMTU /* xxx */
531 	case SIOCGIFMTU:
532 		break;
533 
534 	case SIOCSIFMTU:
535 		mtu = ifr->ifr_mtu;
536 		if (mtu < GIF_MTU_MIN || mtu > GIF_MTU_MAX)
537 			return (EINVAL);
538 		ifp->if_mtu = mtu;
539 		break;
540 #endif /* SIOCSIFMTU */
541 
542 #ifdef INET
543 	case SIOCSIFPHYADDR:
544 #endif
545 #ifdef INET6
546 	case SIOCSIFPHYADDR_IN6:
547 #endif /* INET6 */
548 	case SIOCSLIFPHYADDR:
549 		switch (cmd) {
550 #ifdef INET
551 		case SIOCSIFPHYADDR:
552 			src = (struct sockaddr *)
553 				&(((struct in_aliasreq *)data)->ifra_addr);
554 			dst = (struct sockaddr *)
555 				&(((struct in_aliasreq *)data)->ifra_dstaddr);
556 			break;
557 #endif
558 #ifdef INET6
559 		case SIOCSIFPHYADDR_IN6:
560 			src = (struct sockaddr *)
561 				&(((struct in6_aliasreq *)data)->ifra_addr);
562 			dst = (struct sockaddr *)
563 				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
564 			break;
565 #endif
566 		case SIOCSLIFPHYADDR:
567 			src = (struct sockaddr *)
568 				&(((struct if_laddrreq *)data)->addr);
569 			dst = (struct sockaddr *)
570 				&(((struct if_laddrreq *)data)->dstaddr);
571 			break;
572 		default:
573 			return EINVAL;
574 		}
575 
576 		/* sa_family must be equal */
577 		if (src->sa_family != dst->sa_family)
578 			return EINVAL;
579 
580 		/* validate sa_len */
581 		switch (src->sa_family) {
582 #ifdef INET
583 		case AF_INET:
584 			if (src->sa_len != sizeof(struct sockaddr_in))
585 				return EINVAL;
586 			break;
587 #endif
588 #ifdef INET6
589 		case AF_INET6:
590 			if (src->sa_len != sizeof(struct sockaddr_in6))
591 				return EINVAL;
592 			break;
593 #endif
594 		default:
595 			return EAFNOSUPPORT;
596 		}
597 		switch (dst->sa_family) {
598 #ifdef INET
599 		case AF_INET:
600 			if (dst->sa_len != sizeof(struct sockaddr_in))
601 				return EINVAL;
602 			break;
603 #endif
604 #ifdef INET6
605 		case AF_INET6:
606 			if (dst->sa_len != sizeof(struct sockaddr_in6))
607 				return EINVAL;
608 			break;
609 #endif
610 		default:
611 			return EAFNOSUPPORT;
612 		}
613 
614 		/* check sa_family looks sane for the cmd */
615 		switch (cmd) {
616 		case SIOCSIFPHYADDR:
617 			if (src->sa_family == AF_INET)
618 				break;
619 			return EAFNOSUPPORT;
620 #ifdef INET6
621 		case SIOCSIFPHYADDR_IN6:
622 			if (src->sa_family == AF_INET6)
623 				break;
624 			return EAFNOSUPPORT;
625 #endif /* INET6 */
626 		case SIOCSLIFPHYADDR:
627 			/* checks done in the above */
628 			break;
629 		}
630 
631 		error = gif_set_tunnel(&sc->gif_if, src, dst);
632 		break;
633 
634 #ifdef SIOCDIFPHYADDR
635 	case SIOCDIFPHYADDR:
636 		gif_delete_tunnel(&sc->gif_if);
637 		break;
638 #endif
639 
640 	case SIOCGIFPSRCADDR:
641 #ifdef INET6
642 	case SIOCGIFPSRCADDR_IN6:
643 #endif /* INET6 */
644 		if (sc->gif_psrc == NULL) {
645 			error = EADDRNOTAVAIL;
646 			goto bad;
647 		}
648 		src = sc->gif_psrc;
649 		switch (cmd) {
650 #ifdef INET
651 		case SIOCGIFPSRCADDR:
652 			dst = &ifr->ifr_addr;
653 			size = sizeof(ifr->ifr_addr);
654 			break;
655 #endif /* INET */
656 #ifdef INET6
657 		case SIOCGIFPSRCADDR_IN6:
658 			dst = (struct sockaddr *)
659 				&(((struct in6_ifreq *)data)->ifr_addr);
660 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
661 			break;
662 #endif /* INET6 */
663 		default:
664 			error = EADDRNOTAVAIL;
665 			goto bad;
666 		}
667 		if (src->sa_len > size)
668 			return EINVAL;
669 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
670 		break;
671 
672 	case SIOCGIFPDSTADDR:
673 #ifdef INET6
674 	case SIOCGIFPDSTADDR_IN6:
675 #endif /* INET6 */
676 		if (sc->gif_pdst == NULL) {
677 			error = EADDRNOTAVAIL;
678 			goto bad;
679 		}
680 		src = sc->gif_pdst;
681 		switch (cmd) {
682 #ifdef INET
683 		case SIOCGIFPDSTADDR:
684 			dst = &ifr->ifr_addr;
685 			size = sizeof(ifr->ifr_addr);
686 			break;
687 #endif /* INET */
688 #ifdef INET6
689 		case SIOCGIFPDSTADDR_IN6:
690 			dst = (struct sockaddr *)
691 				&(((struct in6_ifreq *)data)->ifr_addr);
692 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
693 			break;
694 #endif /* INET6 */
695 		default:
696 			error = EADDRNOTAVAIL;
697 			goto bad;
698 		}
699 		if (src->sa_len > size)
700 			return EINVAL;
701 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
702 		break;
703 
704 	case SIOCGLIFPHYADDR:
705 		if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
706 			error = EADDRNOTAVAIL;
707 			goto bad;
708 		}
709 
710 		/* copy src */
711 		src = sc->gif_psrc;
712 		dst = (struct sockaddr *)
713 			&(((struct if_laddrreq *)data)->addr);
714 		size = sizeof(((struct if_laddrreq *)data)->addr);
715 		if (src->sa_len > size)
716 			return EINVAL;
717 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
718 
719 		/* copy dst */
720 		src = sc->gif_pdst;
721 		dst = (struct sockaddr *)
722 			&(((struct if_laddrreq *)data)->dstaddr);
723 		size = sizeof(((struct if_laddrreq *)data)->dstaddr);
724 		if (src->sa_len > size)
725 			return EINVAL;
726 		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
727 		break;
728 
729 	case SIOCSIFFLAGS:
730 		/* if_ioctl() takes care of it */
731 		break;
732 
733 	default:
734 		error = EINVAL;
735 		break;
736 	}
737  bad:
738 	return error;
739 }
740 
741 /*
742  * XXXRW: There's a general event-ordering issue here: the code to check
743  * if a given tunnel is already present happens before we perform a
744  * potentially blocking setup of the tunnel.  This code needs to be
745  * re-ordered so that the check and replacement can be atomic using
746  * a mutex.
747  */
748 int
749 gif_set_tunnel(ifp, src, dst)
750 	struct ifnet *ifp;
751 	struct sockaddr *src;
752 	struct sockaddr *dst;
753 {
754 	struct gif_softc *sc = (struct gif_softc *)ifp;
755 	struct gif_softc *sc2;
756 	struct sockaddr *osrc, *odst, *sa;
757 	int s;
758 	int error = 0;
759 
760 	s = splnet();
761 
762 	mtx_lock(&gif_mtx);
763 	LIST_FOREACH(sc2, &gif_softc_list, gif_list) {
764 		if (sc2 == sc)
765 			continue;
766 		if (!sc2->gif_pdst || !sc2->gif_psrc)
767 			continue;
768 		if (sc2->gif_pdst->sa_family != dst->sa_family ||
769 		    sc2->gif_pdst->sa_len != dst->sa_len ||
770 		    sc2->gif_psrc->sa_family != src->sa_family ||
771 		    sc2->gif_psrc->sa_len != src->sa_len)
772 			continue;
773 
774 		/*
775 		 * Disallow parallel tunnels unless instructed
776 		 * otherwise.
777 		 */
778 		if (!parallel_tunnels &&
779 		    bcmp(sc2->gif_pdst, dst, dst->sa_len) == 0 &&
780 		    bcmp(sc2->gif_psrc, src, src->sa_len) == 0) {
781 			error = EADDRNOTAVAIL;
782 			mtx_unlock(&gif_mtx);
783 			goto bad;
784 		}
785 
786 		/* XXX both end must be valid? (I mean, not 0.0.0.0) */
787 	}
788 	mtx_unlock(&gif_mtx);
789 
790 	/* XXX we can detach from both, but be polite just in case */
791 	if (sc->gif_psrc)
792 		switch (sc->gif_psrc->sa_family) {
793 #ifdef INET
794 		case AF_INET:
795 			(void)in_gif_detach(sc);
796 			break;
797 #endif
798 #ifdef INET6
799 		case AF_INET6:
800 			(void)in6_gif_detach(sc);
801 			break;
802 #endif
803 		}
804 
805 	osrc = sc->gif_psrc;
806 	sa = (struct sockaddr *)malloc(src->sa_len, M_IFADDR, M_WAITOK);
807 	bcopy((caddr_t)src, (caddr_t)sa, src->sa_len);
808 	sc->gif_psrc = sa;
809 
810 	odst = sc->gif_pdst;
811 	sa = (struct sockaddr *)malloc(dst->sa_len, M_IFADDR, M_WAITOK);
812 	bcopy((caddr_t)dst, (caddr_t)sa, dst->sa_len);
813 	sc->gif_pdst = sa;
814 
815 	switch (sc->gif_psrc->sa_family) {
816 #ifdef INET
817 	case AF_INET:
818 		error = in_gif_attach(sc);
819 		break;
820 #endif
821 #ifdef INET6
822 	case AF_INET6:
823 		error = in6_gif_attach(sc);
824 		break;
825 #endif
826 	}
827 	if (error) {
828 		/* rollback */
829 		free((caddr_t)sc->gif_psrc, M_IFADDR);
830 		free((caddr_t)sc->gif_pdst, M_IFADDR);
831 		sc->gif_psrc = osrc;
832 		sc->gif_pdst = odst;
833 		goto bad;
834 	}
835 
836 	if (osrc)
837 		free((caddr_t)osrc, M_IFADDR);
838 	if (odst)
839 		free((caddr_t)odst, M_IFADDR);
840 
841 	if (sc->gif_psrc && sc->gif_pdst)
842 		ifp->if_flags |= IFF_RUNNING;
843 	else
844 		ifp->if_flags &= ~IFF_RUNNING;
845 	splx(s);
846 
847 	return 0;
848 
849  bad:
850 	if (sc->gif_psrc && sc->gif_pdst)
851 		ifp->if_flags |= IFF_RUNNING;
852 	else
853 		ifp->if_flags &= ~IFF_RUNNING;
854 	splx(s);
855 
856 	return error;
857 }
858 
859 void
860 gif_delete_tunnel(ifp)
861 	struct ifnet *ifp;
862 {
863 	struct gif_softc *sc = (struct gif_softc *)ifp;
864 	int s;
865 
866 	s = splnet();
867 
868 	if (sc->gif_psrc) {
869 		free((caddr_t)sc->gif_psrc, M_IFADDR);
870 		sc->gif_psrc = NULL;
871 	}
872 	if (sc->gif_pdst) {
873 		free((caddr_t)sc->gif_pdst, M_IFADDR);
874 		sc->gif_pdst = NULL;
875 	}
876 	/* it is safe to detach from both */
877 #ifdef INET
878 	(void)in_gif_detach(sc);
879 #endif
880 #ifdef INET6
881 	(void)in6_gif_detach(sc);
882 #endif
883 
884 	if (sc->gif_psrc && sc->gif_pdst)
885 		ifp->if_flags |= IFF_RUNNING;
886 	else
887 		ifp->if_flags &= ~IFF_RUNNING;
888 	splx(s);
889 }
890