xref: /netbsd-src/sys/net/if_gif.c (revision 96230fab84e26a6435963032070e916a951a8b2e)
1 /*	$NetBSD: if_gif.c,v 1.75 2008/06/15 16:37:21 christos Exp $	*/
2 /*	$KAME: if_gif.c,v 1.76 2001/08/20 02:01:02 kjc 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 <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: if_gif.c,v 1.75 2008/06/15 16:37:21 christos Exp $");
35 
36 #include "opt_inet.h"
37 #include "opt_iso.h"
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kernel.h>
42 #include <sys/mbuf.h>
43 #include <sys/socket.h>
44 #include <sys/sockio.h>
45 #include <sys/errno.h>
46 #include <sys/ioctl.h>
47 #include <sys/time.h>
48 #include <sys/syslog.h>
49 #include <sys/proc.h>
50 #include <sys/protosw.h>
51 #include <sys/kauth.h>
52 #include <sys/cpu.h>
53 #include <sys/intr.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 
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 #endif	/* INET */
67 #include <netinet/in_gif.h>
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 #ifdef ISO
81 #include <netiso/iso.h>
82 #include <netiso/iso_var.h>
83 #endif
84 
85 #include <netinet/ip_encap.h>
86 #include <net/if_gif.h>
87 
88 #include "bpfilter.h"
89 
90 #include <net/net_osdep.h>
91 
92 void	gifattach(int);
93 static void	gifintr(void *);
94 #ifdef ISO
95 static struct mbuf *gif_eon_encap(struct mbuf *);
96 static struct mbuf *gif_eon_decap(struct ifnet *, struct mbuf *);
97 #endif
98 
99 /*
100  * gif global variable definitions
101  */
102 LIST_HEAD(, gif_softc) gif_softc_list;	/* XXX should be static */
103 
104 static int	gif_clone_create(struct if_clone *, int);
105 static int	gif_clone_destroy(struct ifnet *);
106 
107 static struct if_clone gif_cloner =
108     IF_CLONE_INITIALIZER("gif", gif_clone_create, gif_clone_destroy);
109 
110 #ifndef MAX_GIF_NEST
111 /*
112  * This macro controls the upper limitation on nesting of gif tunnels.
113  * Since, setting a large value to this macro with a careless configuration
114  * may introduce system crash, we don't allow any nestings by default.
115  * If you need to configure nested gif tunnels, you can define this macro
116  * in your kernel configuration file.  However, if you do so, please be
117  * careful to configure the tunnels so that it won't make a loop.
118  */
119 #define MAX_GIF_NEST 1
120 #endif
121 static int max_gif_nesting = MAX_GIF_NEST;
122 
123 /* ARGSUSED */
124 void
125 gifattach(int count)
126 {
127 
128 	LIST_INIT(&gif_softc_list);
129 	if_clone_attach(&gif_cloner);
130 }
131 
132 static int
133 gif_clone_create(struct if_clone *ifc, int unit)
134 {
135 	struct gif_softc *sc;
136 
137 	sc = malloc(sizeof(struct gif_softc), M_DEVBUF, M_WAITOK|M_ZERO);
138 
139 	if_initname(&sc->gif_if, ifc->ifc_name, unit);
140 
141 	gifattach0(sc);
142 
143 	LIST_INSERT_HEAD(&gif_softc_list, sc, gif_list);
144 	return (0);
145 }
146 
147 void
148 gifattach0(struct gif_softc *sc)
149 {
150 
151 	sc->encap_cookie4 = sc->encap_cookie6 = NULL;
152 
153 	sc->gif_if.if_addrlen = 0;
154 	sc->gif_if.if_mtu    = GIF_MTU;
155 	sc->gif_if.if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
156 	sc->gif_if.if_ioctl  = gif_ioctl;
157 	sc->gif_if.if_output = gif_output;
158 	sc->gif_if.if_type   = IFT_GIF;
159 	sc->gif_if.if_dlt    = DLT_NULL;
160 	IFQ_SET_READY(&sc->gif_if.if_snd);
161 	if_attach(&sc->gif_if);
162 	if_alloc_sadl(&sc->gif_if);
163 #if NBPFILTER > 0
164 	bpfattach(&sc->gif_if, DLT_NULL, sizeof(u_int));
165 #endif
166 }
167 
168 static int
169 gif_clone_destroy(struct ifnet *ifp)
170 {
171 	struct gif_softc *sc = (void *) ifp;
172 
173 	gif_delete_tunnel(&sc->gif_if);
174 	LIST_REMOVE(sc, gif_list);
175 #ifdef INET6
176 	encap_detach(sc->encap_cookie6);
177 #endif
178 #ifdef INET
179 	encap_detach(sc->encap_cookie4);
180 #endif
181 
182 #if NBPFILTER > 0
183 	bpfdetach(ifp);
184 #endif
185 	if_detach(ifp);
186 	rtcache_free(&sc->gif_ro);
187 
188 	free(sc, M_DEVBUF);
189 
190 	return (0);
191 }
192 
193 #ifdef GIF_ENCAPCHECK
194 int
195 gif_encapcheck(struct mbuf *m, int off, int proto, void *arg)
196 {
197 	struct ip ip;
198 	struct gif_softc *sc;
199 
200 	sc = (struct gif_softc *)arg;
201 	if (sc == NULL)
202 		return 0;
203 
204 	if ((sc->gif_if.if_flags & IFF_UP) == 0)
205 		return 0;
206 
207 	/* no physical address */
208 	if (!sc->gif_psrc || !sc->gif_pdst)
209 		return 0;
210 
211 	switch (proto) {
212 #ifdef INET
213 	case IPPROTO_IPV4:
214 		break;
215 #endif
216 #ifdef INET6
217 	case IPPROTO_IPV6:
218 		break;
219 #endif
220 #ifdef ISO
221 	case IPPROTO_EON:
222 		break;
223 #endif
224 	default:
225 		return 0;
226 	}
227 
228 	/* Bail on short packets */
229 	KASSERT(m->m_flags & M_PKTHDR);
230 	if (m->m_pkthdr.len < sizeof(ip))
231 		return 0;
232 
233 	m_copydata(m, 0, sizeof(ip), (void *)&ip);
234 
235 	switch (ip.ip_v) {
236 #ifdef INET
237 	case 4:
238 		if (sc->gif_psrc->sa_family != AF_INET ||
239 		    sc->gif_pdst->sa_family != AF_INET)
240 			return 0;
241 		return gif_encapcheck4(m, off, proto, arg);
242 #endif
243 #ifdef INET6
244 	case 6:
245 		if (m->m_pkthdr.len < sizeof(struct ip6_hdr))
246 			return 0;
247 		if (sc->gif_psrc->sa_family != AF_INET6 ||
248 		    sc->gif_pdst->sa_family != AF_INET6)
249 			return 0;
250 		return gif_encapcheck6(m, off, proto, arg);
251 #endif
252 	default:
253 		return 0;
254 	}
255 }
256 #endif
257 
258 int
259 gif_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
260     struct rtentry *rt)
261 {
262 	struct gif_softc *sc = (struct gif_softc*)ifp;
263 	int error = 0;
264 	static int called = 0;	/* XXX: MUTEX */
265 	ALTQ_DECL(struct altq_pktattr pktattr;)
266 	int s;
267 
268 	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
269 
270 	/*
271 	 * gif may cause infinite recursion calls when misconfigured.
272 	 * We'll prevent this by introducing upper limit.
273 	 * XXX: this mechanism may introduce another problem about
274 	 *      mutual exclusion of the variable CALLED, especially if we
275 	 *      use kernel thread.
276 	 */
277 	if (++called > max_gif_nesting) {
278 		log(LOG_NOTICE,
279 		    "gif_output: recursively called too many times(%d)\n",
280 		    called);
281 		m_freem(m);
282 		error = EIO;	/* is there better errno? */
283 		goto end;
284 	}
285 
286 	m->m_flags &= ~(M_BCAST|M_MCAST);
287 	if (!(ifp->if_flags & IFF_UP) ||
288 	    sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
289 		m_freem(m);
290 		error = ENETDOWN;
291 		goto end;
292 	}
293 
294 	/* inner AF-specific encapsulation */
295 	switch (dst->sa_family) {
296 #ifdef ISO
297 	case AF_ISO:
298 		m = gif_eon_encap(m);
299 		if (!m) {
300 			error = ENOBUFS;
301 			goto end;
302 		}
303 		break;
304 #endif
305 	default:
306 		break;
307 	}
308 
309 	/* XXX should we check if our outer source is legal? */
310 
311 	/* use DLT_NULL encapsulation here to pass inner af type */
312 	M_PREPEND(m, sizeof(int), M_DONTWAIT);
313 	if (!m) {
314 		error = ENOBUFS;
315 		goto end;
316 	}
317 	*mtod(m, int *) = dst->sa_family;
318 
319 	s = splnet();
320 	IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
321 	if (error) {
322 		splx(s);
323 		goto end;
324 	}
325 	splx(s);
326 
327 	softint_schedule(sc->gif_si);
328 	error = 0;
329 
330   end:
331 	called = 0;		/* reset recursion counter */
332 	if (error)
333 		ifp->if_oerrors++;
334 	return error;
335 }
336 
337 static void
338 gifintr(void *arg)
339 {
340 	struct gif_softc *sc;
341 	struct ifnet *ifp;
342 	struct mbuf *m;
343 	int family;
344 	int len;
345 	int s;
346 	int error;
347 
348 	sc = (struct gif_softc *)arg;
349 	ifp = &sc->gif_if;
350 
351 	/* output processing */
352 	while (1) {
353 		s = splnet();
354 		IFQ_DEQUEUE(&sc->gif_if.if_snd, m);
355 		splx(s);
356 		if (m == NULL)
357 			break;
358 
359 		/* grab and chop off inner af type */
360 		if (sizeof(int) > m->m_len) {
361 			m = m_pullup(m, sizeof(int));
362 			if (!m) {
363 				ifp->if_oerrors++;
364 				continue;
365 			}
366 		}
367 		family = *mtod(m, int *);
368 #if NBPFILTER > 0
369 		if (ifp->if_bpf)
370 			bpf_mtap(ifp->if_bpf, m);
371 #endif
372 		m_adj(m, sizeof(int));
373 
374 		len = m->m_pkthdr.len;
375 
376 		/* dispatch to output logic based on outer AF */
377 		switch (sc->gif_psrc->sa_family) {
378 #ifdef INET
379 		case AF_INET:
380 			error = in_gif_output(ifp, family, m);
381 			break;
382 #endif
383 #ifdef INET6
384 		case AF_INET6:
385 			error = in6_gif_output(ifp, family, m);
386 			break;
387 #endif
388 		default:
389 			m_freem(m);
390 			error = ENETDOWN;
391 			break;
392 		}
393 
394 		if (error)
395 			ifp->if_oerrors++;
396 		else {
397 			ifp->if_opackets++;
398 			ifp->if_obytes += len;
399 		}
400 	}
401 }
402 
403 void
404 gif_input(struct mbuf *m, int af, struct ifnet *ifp)
405 {
406 	int s, isr;
407 	struct ifqueue *ifq = NULL;
408 
409 	if (ifp == NULL) {
410 		/* just in case */
411 		m_freem(m);
412 		return;
413 	}
414 
415 	m->m_pkthdr.rcvif = ifp;
416 
417 #if NBPFILTER > 0
418 	if (ifp->if_bpf)
419 		bpf_mtap_af(ifp->if_bpf, af, m);
420 #endif /*NBPFILTER > 0*/
421 
422 	/*
423 	 * Put the packet to the network layer input queue according to the
424 	 * specified address family.
425 	 * Note: older versions of gif_input directly called network layer
426 	 * input functions, e.g. ip6_input, here.  We changed the policy to
427 	 * prevent too many recursive calls of such input functions, which
428 	 * might cause kernel panic.  But the change may introduce another
429 	 * problem; if the input queue is full, packets are discarded.
430 	 * The kernel stack overflow really happened, and we believed
431 	 * queue-full rarely occurs, so we changed the policy.
432 	 */
433 	switch (af) {
434 #ifdef INET
435 	case AF_INET:
436 		ifq = &ipintrq;
437 		isr = NETISR_IP;
438 		break;
439 #endif
440 #ifdef INET6
441 	case AF_INET6:
442 		ifq = &ip6intrq;
443 		isr = NETISR_IPV6;
444 		break;
445 #endif
446 #ifdef ISO
447 	case AF_ISO:
448 		m = gif_eon_decap(ifp, m);
449 		if (!m)
450 			return;
451 		ifq = &clnlintrq;
452 		isr = NETISR_ISO;
453 		break;
454 #endif
455 	default:
456 		m_freem(m);
457 		return;
458 	}
459 
460 	s = splnet();
461 	if (IF_QFULL(ifq)) {
462 		IF_DROP(ifq);	/* update statistics */
463 		m_freem(m);
464 		splx(s);
465 		return;
466 	}
467 	ifp->if_ipackets++;
468 	ifp->if_ibytes += m->m_pkthdr.len;
469 	IF_ENQUEUE(ifq, m);
470 	/* we need schednetisr since the address family may change */
471 	schednetisr(isr);
472 	splx(s);
473 }
474 
475 /* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
476 int
477 gif_ioctl(struct ifnet *ifp, u_long cmd, void *data)
478 {
479 	struct lwp *l = curlwp;	/* XXX */
480 	struct gif_softc *sc  = (struct gif_softc*)ifp;
481 	struct ifreq     *ifr = (struct ifreq*)data;
482 	int error = 0, size;
483 	struct sockaddr *dst, *src;
484 
485 	switch (cmd) {
486 	case SIOCSIFMTU:
487 	case SIOCSLIFPHYADDR:
488 #ifdef SIOCDIFPHYADDR
489 	case SIOCDIFPHYADDR:
490 #endif
491 		if ((error = kauth_authorize_network(l->l_cred,
492 		    KAUTH_NETWORK_INTERFACE,
493 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
494 		    NULL)) != 0)
495 			return (error);
496 		/* FALLTHROUGH */
497 	default:
498 		break;
499 	}
500 
501 	switch (cmd) {
502 	case SIOCSIFADDR:
503 		ifp->if_flags |= IFF_UP;
504 		break;
505 
506 	case SIOCSIFDSTADDR:
507 		break;
508 
509 	case SIOCADDMULTI:
510 	case SIOCDELMULTI:
511 		switch (ifr->ifr_addr.sa_family) {
512 #ifdef INET
513 		case AF_INET:	/* IP supports Multicast */
514 			break;
515 #endif /* INET */
516 #ifdef INET6
517 		case AF_INET6:	/* IP6 supports Multicast */
518 			break;
519 #endif /* INET6 */
520 		default:  /* Other protocols doesn't support Multicast */
521 			error = EAFNOSUPPORT;
522 			break;
523 		}
524 		break;
525 
526 	case SIOCGIFMTU:
527 		break;
528 
529 	case SIOCSIFMTU:
530 		if (ifr->ifr_mtu < GIF_MTU_MIN || ifr->ifr_mtu > GIF_MTU_MAX)
531 			return EINVAL;
532 		else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
533 			error = 0;
534 		break;
535 
536 #ifdef INET
537 	case SIOCSIFPHYADDR:
538 #endif
539 #ifdef INET6
540 	case SIOCSIFPHYADDR_IN6:
541 #endif /* INET6 */
542 	case SIOCSLIFPHYADDR:
543 		switch (cmd) {
544 #ifdef INET
545 		case SIOCSIFPHYADDR:
546 			src = (struct sockaddr *)
547 				&(((struct in_aliasreq *)data)->ifra_addr);
548 			dst = (struct sockaddr *)
549 				&(((struct in_aliasreq *)data)->ifra_dstaddr);
550 			break;
551 #endif
552 #ifdef INET6
553 		case SIOCSIFPHYADDR_IN6:
554 			src = (struct sockaddr *)
555 				&(((struct in6_aliasreq *)data)->ifra_addr);
556 			dst = (struct sockaddr *)
557 				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
558 			break;
559 #endif
560 		case SIOCSLIFPHYADDR:
561 			src = (struct sockaddr *)
562 				&(((struct if_laddrreq *)data)->addr);
563 			dst = (struct sockaddr *)
564 				&(((struct if_laddrreq *)data)->dstaddr);
565 			break;
566 		default:
567 			return EINVAL;
568 		}
569 
570 		/* sa_family must be equal */
571 		if (src->sa_family != dst->sa_family)
572 			return EINVAL;
573 
574 		/* validate sa_len */
575 		switch (src->sa_family) {
576 #ifdef INET
577 		case AF_INET:
578 			if (src->sa_len != sizeof(struct sockaddr_in))
579 				return EINVAL;
580 			break;
581 #endif
582 #ifdef INET6
583 		case AF_INET6:
584 			if (src->sa_len != sizeof(struct sockaddr_in6))
585 				return EINVAL;
586 			break;
587 #endif
588 		default:
589 			return EAFNOSUPPORT;
590 		}
591 		switch (dst->sa_family) {
592 #ifdef INET
593 		case AF_INET:
594 			if (dst->sa_len != sizeof(struct sockaddr_in))
595 				return EINVAL;
596 			break;
597 #endif
598 #ifdef INET6
599 		case AF_INET6:
600 			if (dst->sa_len != sizeof(struct sockaddr_in6))
601 				return EINVAL;
602 			break;
603 #endif
604 		default:
605 			return EAFNOSUPPORT;
606 		}
607 
608 		/* check sa_family looks sane for the cmd */
609 		switch (cmd) {
610 		case SIOCSIFPHYADDR:
611 			if (src->sa_family == AF_INET)
612 				break;
613 			return EAFNOSUPPORT;
614 #ifdef INET6
615 		case SIOCSIFPHYADDR_IN6:
616 			if (src->sa_family == AF_INET6)
617 				break;
618 			return EAFNOSUPPORT;
619 #endif /* INET6 */
620 		case SIOCSLIFPHYADDR:
621 			/* checks done in the above */
622 			break;
623 		}
624 
625 		error = gif_set_tunnel(&sc->gif_if, src, dst);
626 		break;
627 
628 #ifdef SIOCDIFPHYADDR
629 	case SIOCDIFPHYADDR:
630 		gif_delete_tunnel(&sc->gif_if);
631 		break;
632 #endif
633 
634 	case SIOCGIFPSRCADDR:
635 #ifdef INET6
636 	case SIOCGIFPSRCADDR_IN6:
637 #endif /* INET6 */
638 		if (sc->gif_psrc == NULL) {
639 			error = EADDRNOTAVAIL;
640 			goto bad;
641 		}
642 		src = sc->gif_psrc;
643 		switch (cmd) {
644 #ifdef INET
645 		case SIOCGIFPSRCADDR:
646 			dst = &ifr->ifr_addr;
647 			size = sizeof(ifr->ifr_addr);
648 			break;
649 #endif /* INET */
650 #ifdef INET6
651 		case SIOCGIFPSRCADDR_IN6:
652 			dst = (struct sockaddr *)
653 				&(((struct in6_ifreq *)data)->ifr_addr);
654 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
655 			break;
656 #endif /* INET6 */
657 		default:
658 			error = EADDRNOTAVAIL;
659 			goto bad;
660 		}
661 		if (src->sa_len > size)
662 			return EINVAL;
663 		memcpy(dst, src, src->sa_len);
664 		break;
665 
666 	case SIOCGIFPDSTADDR:
667 #ifdef INET6
668 	case SIOCGIFPDSTADDR_IN6:
669 #endif /* INET6 */
670 		if (sc->gif_pdst == NULL) {
671 			error = EADDRNOTAVAIL;
672 			goto bad;
673 		}
674 		src = sc->gif_pdst;
675 		switch (cmd) {
676 #ifdef INET
677 		case SIOCGIFPDSTADDR:
678 			dst = &ifr->ifr_addr;
679 			size = sizeof(ifr->ifr_addr);
680 			break;
681 #endif /* INET */
682 #ifdef INET6
683 		case SIOCGIFPDSTADDR_IN6:
684 			dst = (struct sockaddr *)
685 				&(((struct in6_ifreq *)data)->ifr_addr);
686 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
687 			break;
688 #endif /* INET6 */
689 		default:
690 			error = EADDRNOTAVAIL;
691 			goto bad;
692 		}
693 		if (src->sa_len > size)
694 			return EINVAL;
695 		memcpy(dst, src, src->sa_len);
696 		break;
697 
698 	case SIOCGLIFPHYADDR:
699 		if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
700 			error = EADDRNOTAVAIL;
701 			goto bad;
702 		}
703 
704 		/* copy src */
705 		src = sc->gif_psrc;
706 		dst = (struct sockaddr *)
707 			&(((struct if_laddrreq *)data)->addr);
708 		size = sizeof(((struct if_laddrreq *)data)->addr);
709 		if (src->sa_len > size)
710 			return EINVAL;
711 		memcpy(dst, src, src->sa_len);
712 
713 		/* copy dst */
714 		src = sc->gif_pdst;
715 		dst = (struct sockaddr *)
716 			&(((struct if_laddrreq *)data)->dstaddr);
717 		size = sizeof(((struct if_laddrreq *)data)->dstaddr);
718 		if (src->sa_len > size)
719 			return EINVAL;
720 		memcpy(dst, src, src->sa_len);
721 		break;
722 
723 	case SIOCSIFFLAGS:
724 		/* if_ioctl() takes care of it */
725 		break;
726 
727 	default:
728 		error = EINVAL;
729 		break;
730 	}
731  bad:
732 	return error;
733 }
734 
735 int
736 gif_set_tunnel(struct ifnet *ifp, struct sockaddr *src, struct sockaddr *dst)
737 {
738 	struct gif_softc *sc = (struct gif_softc *)ifp;
739 	struct gif_softc *sc2;
740 	struct sockaddr *osrc, *odst;
741 	int s;
742 	int error;
743 
744 	s = splsoftnet();
745 
746 	LIST_FOREACH(sc2, &gif_softc_list, gif_list) {
747 		if (sc2 == sc)
748 			continue;
749 		if (!sc2->gif_pdst || !sc2->gif_psrc)
750 			continue;
751 		/* can't configure same pair of address onto two gifs */
752 		if (sockaddr_cmp(sc2->gif_pdst, dst) == 0 &&
753 		    sockaddr_cmp(sc2->gif_psrc, src) == 0) {
754 			error = EADDRNOTAVAIL;
755 			goto bad;
756 		}
757 
758 		/* XXX both end must be valid? (I mean, not 0.0.0.0) */
759 	}
760 
761 	if (sc->gif_si) {
762 		softint_disestablish(sc->gif_si);
763 		sc->gif_si = NULL;
764 	}
765 
766 	/* XXX we can detach from both, but be polite just in case */
767 	if (sc->gif_psrc)
768 		switch (sc->gif_psrc->sa_family) {
769 #ifdef INET
770 		case AF_INET:
771 			(void)in_gif_detach(sc);
772 			break;
773 #endif
774 #ifdef INET6
775 		case AF_INET6:
776 			(void)in6_gif_detach(sc);
777 			break;
778 #endif
779 		}
780 
781 	sc->gif_si = softint_establish(SOFTINT_NET, gifintr, sc);
782 	if (sc->gif_si == NULL) {
783 		error = ENOMEM;
784 		goto bad;
785 	}
786 
787 	osrc = sc->gif_psrc;
788 	sc->gif_psrc = sockaddr_dup(src, M_WAITOK);
789 
790 	odst = sc->gif_pdst;
791 	sc->gif_pdst = sockaddr_dup(dst, M_WAITOK);
792 
793 	switch (sc->gif_psrc->sa_family) {
794 #ifdef INET
795 	case AF_INET:
796 		error = in_gif_attach(sc);
797 		break;
798 #endif
799 #ifdef INET6
800 	case AF_INET6:
801 		error = in6_gif_attach(sc);
802 		break;
803 #endif
804 	default:
805 		error = EINVAL;
806 		break;
807 	}
808 	if (error) {
809 		/* rollback */
810 		sockaddr_free(sc->gif_psrc);
811 		sockaddr_free(sc->gif_pdst);
812 		sc->gif_psrc = osrc;
813 		sc->gif_pdst = odst;
814 		goto bad;
815 	}
816 
817 	if (osrc)
818 		sockaddr_free(osrc);
819 	if (odst)
820 		sockaddr_free(odst);
821 
822 	if (sc->gif_psrc && sc->gif_pdst)
823 		ifp->if_flags |= IFF_RUNNING;
824 	else
825 		ifp->if_flags &= ~IFF_RUNNING;
826 	splx(s);
827 
828 	return 0;
829 
830  bad:
831 	if (sc->gif_si) {
832 		softint_disestablish(sc->gif_si);
833 		sc->gif_si = NULL;
834 	}
835 	if (sc->gif_psrc && sc->gif_pdst)
836 		ifp->if_flags |= IFF_RUNNING;
837 	else
838 		ifp->if_flags &= ~IFF_RUNNING;
839 	splx(s);
840 
841 	return error;
842 }
843 
844 void
845 gif_delete_tunnel(struct ifnet *ifp)
846 {
847 	struct gif_softc *sc = (struct gif_softc *)ifp;
848 	int s;
849 
850 	s = splsoftnet();
851 
852 	if (sc->gif_si) {
853 		softint_disestablish(sc->gif_si);
854 		sc->gif_si = NULL;
855 	}
856 	if (sc->gif_psrc) {
857 		sockaddr_free(sc->gif_psrc);
858 		sc->gif_psrc = NULL;
859 	}
860 	if (sc->gif_pdst) {
861 		sockaddr_free(sc->gif_pdst);
862 		sc->gif_pdst = NULL;
863 	}
864 	/* it is safe to detach from both */
865 #ifdef INET
866 	(void)in_gif_detach(sc);
867 #endif
868 #ifdef INET6
869 	(void)in6_gif_detach(sc);
870 #endif
871 
872 	if (sc->gif_psrc && sc->gif_pdst)
873 		ifp->if_flags |= IFF_RUNNING;
874 	else
875 		ifp->if_flags &= ~IFF_RUNNING;
876 	splx(s);
877 }
878 
879 #ifdef ISO
880 struct eonhdr {
881 	uint8_t version;
882 	uint8_t class;
883 	uint16_t cksum;
884 };
885 
886 /*
887  * prepend EON header to ISO PDU
888  */
889 static struct mbuf *
890 gif_eon_encap(struct mbuf *m)
891 {
892 	struct eonhdr *ehdr;
893 
894 	M_PREPEND(m, sizeof(*ehdr), M_DONTWAIT);
895 	if (m && m->m_len < sizeof(*ehdr))
896 		m = m_pullup(m, sizeof(*ehdr));
897 	if (m == NULL)
898 		return NULL;
899 	ehdr = mtod(m, struct eonhdr *);
900 	ehdr->version = 1;
901 	ehdr->class = 0;		/* always unicast */
902 #if 0
903 	/* calculate the checksum of the eonhdr */
904 	{
905 		struct mbuf mhead;
906 		memset(&mhead, 0, sizeof(mhead));
907 		ehdr->cksum = 0;
908 		mhead.m_data = (void *)ehdr;
909 		mhead.m_len = sizeof(*ehdr);
910 		mhead.m_next = 0;
911 		iso_gen_csum(&mhead, offsetof(struct eonhdr, cksum),
912 		    mhead.m_len);
913 	}
914 #else
915 	/* since the data is always constant we'll just plug the value in */
916 	ehdr->cksum = htons(0xfc02);
917 #endif
918 	return m;
919 }
920 
921 /*
922  * remove EON header and check checksum
923  */
924 static struct mbuf *
925 gif_eon_decap(struct ifnet *ifp, struct mbuf *m)
926 {
927 	struct eonhdr *ehdr;
928 
929 	if (m->m_len < sizeof(*ehdr) &&
930 	    (m = m_pullup(m, sizeof(*ehdr))) == NULL) {
931 		ifp->if_ierrors++;
932 		return NULL;
933 	}
934 	if (iso_check_csum(m, sizeof(struct eonhdr))) {
935 		m_freem(m);
936 		return NULL;
937 	}
938 	m_adj(m, sizeof(*ehdr));
939 	return m;
940 }
941 #endif /*ISO*/
942