xref: /netbsd-src/sys/net/if_gif.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1 /*	$NetBSD: if_gif.c,v 1.76 2008/11/07 00:20:13 dyoung 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 1.76 2008/11/07 00:20:13 dyoung 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 	sc->gif_if.if_softc  = sc;
161 	IFQ_SET_READY(&sc->gif_if.if_snd);
162 	if_attach(&sc->gif_if);
163 	if_alloc_sadl(&sc->gif_if);
164 #if NBPFILTER > 0
165 	bpfattach(&sc->gif_if, DLT_NULL, sizeof(u_int));
166 #endif
167 }
168 
169 static int
170 gif_clone_destroy(struct ifnet *ifp)
171 {
172 	struct gif_softc *sc = (void *) ifp;
173 
174 	gif_delete_tunnel(&sc->gif_if);
175 	LIST_REMOVE(sc, gif_list);
176 #ifdef INET6
177 	encap_detach(sc->encap_cookie6);
178 #endif
179 #ifdef INET
180 	encap_detach(sc->encap_cookie4);
181 #endif
182 
183 #if NBPFILTER > 0
184 	bpfdetach(ifp);
185 #endif
186 	if_detach(ifp);
187 	rtcache_free(&sc->gif_ro);
188 
189 	free(sc, M_DEVBUF);
190 
191 	return (0);
192 }
193 
194 #ifdef GIF_ENCAPCHECK
195 int
196 gif_encapcheck(struct mbuf *m, int off, int proto, void *arg)
197 {
198 	struct ip ip;
199 	struct gif_softc *sc;
200 
201 	sc = arg;
202 	if (sc == NULL)
203 		return 0;
204 
205 	if ((sc->gif_if.if_flags & IFF_UP) == 0)
206 		return 0;
207 
208 	/* no physical address */
209 	if (!sc->gif_psrc || !sc->gif_pdst)
210 		return 0;
211 
212 	switch (proto) {
213 #ifdef INET
214 	case IPPROTO_IPV4:
215 		break;
216 #endif
217 #ifdef INET6
218 	case IPPROTO_IPV6:
219 		break;
220 #endif
221 #ifdef ISO
222 	case IPPROTO_EON:
223 		break;
224 #endif
225 	default:
226 		return 0;
227 	}
228 
229 	/* Bail on short packets */
230 	KASSERT(m->m_flags & M_PKTHDR);
231 	if (m->m_pkthdr.len < sizeof(ip))
232 		return 0;
233 
234 	m_copydata(m, 0, sizeof(ip), &ip);
235 
236 	switch (ip.ip_v) {
237 #ifdef INET
238 	case 4:
239 		if (sc->gif_psrc->sa_family != AF_INET ||
240 		    sc->gif_pdst->sa_family != AF_INET)
241 			return 0;
242 		return gif_encapcheck4(m, off, proto, arg);
243 #endif
244 #ifdef INET6
245 	case 6:
246 		if (m->m_pkthdr.len < sizeof(struct ip6_hdr))
247 			return 0;
248 		if (sc->gif_psrc->sa_family != AF_INET6 ||
249 		    sc->gif_pdst->sa_family != AF_INET6)
250 			return 0;
251 		return gif_encapcheck6(m, off, proto, arg);
252 #endif
253 	default:
254 		return 0;
255 	}
256 }
257 #endif
258 
259 int
260 gif_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
261     struct rtentry *rt)
262 {
263 	struct gif_softc *sc = ifp->if_softc;
264 	int error = 0;
265 	static int called = 0;	/* XXX: MUTEX */
266 	ALTQ_DECL(struct altq_pktattr pktattr;)
267 	int s;
268 
269 	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
270 
271 	/*
272 	 * gif may cause infinite recursion calls when misconfigured.
273 	 * We'll prevent this by introducing upper limit.
274 	 * XXX: this mechanism may introduce another problem about
275 	 *      mutual exclusion of the variable CALLED, especially if we
276 	 *      use kernel thread.
277 	 */
278 	if (++called > max_gif_nesting) {
279 		log(LOG_NOTICE,
280 		    "gif_output: recursively called too many times(%d)\n",
281 		    called);
282 		m_freem(m);
283 		error = EIO;	/* is there better errno? */
284 		goto end;
285 	}
286 
287 	m->m_flags &= ~(M_BCAST|M_MCAST);
288 	if (!(ifp->if_flags & IFF_UP) ||
289 	    sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
290 		m_freem(m);
291 		error = ENETDOWN;
292 		goto end;
293 	}
294 
295 	/* inner AF-specific encapsulation */
296 	switch (dst->sa_family) {
297 #ifdef ISO
298 	case AF_ISO:
299 		m = gif_eon_encap(m);
300 		if (!m) {
301 			error = ENOBUFS;
302 			goto end;
303 		}
304 		break;
305 #endif
306 	default:
307 		break;
308 	}
309 
310 	/* XXX should we check if our outer source is legal? */
311 
312 	/* use DLT_NULL encapsulation here to pass inner af type */
313 	M_PREPEND(m, sizeof(int), M_DONTWAIT);
314 	if (!m) {
315 		error = ENOBUFS;
316 		goto end;
317 	}
318 	*mtod(m, int *) = dst->sa_family;
319 
320 	s = splnet();
321 	IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
322 	if (error) {
323 		splx(s);
324 		goto end;
325 	}
326 	splx(s);
327 
328 	softint_schedule(sc->gif_si);
329 	error = 0;
330 
331   end:
332 	called = 0;		/* reset recursion counter */
333 	if (error)
334 		ifp->if_oerrors++;
335 	return error;
336 }
337 
338 static void
339 gifintr(void *arg)
340 {
341 	struct gif_softc *sc;
342 	struct ifnet *ifp;
343 	struct mbuf *m;
344 	int family;
345 	int len;
346 	int s;
347 	int error;
348 
349 	sc = arg;
350 	ifp = &sc->gif_if;
351 
352 	/* output processing */
353 	while (1) {
354 		s = splnet();
355 		IFQ_DEQUEUE(&sc->gif_if.if_snd, m);
356 		splx(s);
357 		if (m == NULL)
358 			break;
359 
360 		/* grab and chop off inner af type */
361 		if (sizeof(int) > m->m_len) {
362 			m = m_pullup(m, sizeof(int));
363 			if (!m) {
364 				ifp->if_oerrors++;
365 				continue;
366 			}
367 		}
368 		family = *mtod(m, int *);
369 #if NBPFILTER > 0
370 		if (ifp->if_bpf)
371 			bpf_mtap(ifp->if_bpf, m);
372 #endif
373 		m_adj(m, sizeof(int));
374 
375 		len = m->m_pkthdr.len;
376 
377 		/* dispatch to output logic based on outer AF */
378 		switch (sc->gif_psrc->sa_family) {
379 #ifdef INET
380 		case AF_INET:
381 			error = in_gif_output(ifp, family, m);
382 			break;
383 #endif
384 #ifdef INET6
385 		case AF_INET6:
386 			error = in6_gif_output(ifp, family, m);
387 			break;
388 #endif
389 		default:
390 			m_freem(m);
391 			error = ENETDOWN;
392 			break;
393 		}
394 
395 		if (error)
396 			ifp->if_oerrors++;
397 		else {
398 			ifp->if_opackets++;
399 			ifp->if_obytes += len;
400 		}
401 	}
402 }
403 
404 void
405 gif_input(struct mbuf *m, int af, struct ifnet *ifp)
406 {
407 	int s, isr;
408 	struct ifqueue *ifq = NULL;
409 
410 	if (ifp == NULL) {
411 		/* just in case */
412 		m_freem(m);
413 		return;
414 	}
415 
416 	m->m_pkthdr.rcvif = ifp;
417 
418 #if NBPFILTER > 0
419 	if (ifp->if_bpf)
420 		bpf_mtap_af(ifp->if_bpf, af, m);
421 #endif /*NBPFILTER > 0*/
422 
423 	/*
424 	 * Put the packet to the network layer input queue according to the
425 	 * specified address family.
426 	 * Note: older versions of gif_input directly called network layer
427 	 * input functions, e.g. ip6_input, here.  We changed the policy to
428 	 * prevent too many recursive calls of such input functions, which
429 	 * might cause kernel panic.  But the change may introduce another
430 	 * problem; if the input queue is full, packets are discarded.
431 	 * The kernel stack overflow really happened, and we believed
432 	 * queue-full rarely occurs, so we changed the policy.
433 	 */
434 	switch (af) {
435 #ifdef INET
436 	case AF_INET:
437 		ifq = &ipintrq;
438 		isr = NETISR_IP;
439 		break;
440 #endif
441 #ifdef INET6
442 	case AF_INET6:
443 		ifq = &ip6intrq;
444 		isr = NETISR_IPV6;
445 		break;
446 #endif
447 #ifdef ISO
448 	case AF_ISO:
449 		m = gif_eon_decap(ifp, m);
450 		if (!m)
451 			return;
452 		ifq = &clnlintrq;
453 		isr = NETISR_ISO;
454 		break;
455 #endif
456 	default:
457 		m_freem(m);
458 		return;
459 	}
460 
461 	s = splnet();
462 	if (IF_QFULL(ifq)) {
463 		IF_DROP(ifq);	/* update statistics */
464 		m_freem(m);
465 		splx(s);
466 		return;
467 	}
468 	ifp->if_ipackets++;
469 	ifp->if_ibytes += m->m_pkthdr.len;
470 	IF_ENQUEUE(ifq, m);
471 	/* we need schednetisr since the address family may change */
472 	schednetisr(isr);
473 	splx(s);
474 }
475 
476 /* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
477 int
478 gif_ioctl(struct ifnet *ifp, u_long cmd, void *data)
479 {
480 	struct lwp *l = curlwp;	/* XXX */
481 	struct gif_softc *sc  = ifp->if_softc;
482 	struct ifreq     *ifr = (struct ifreq*)data;
483 	int error = 0, size;
484 	struct sockaddr *dst, *src;
485 
486 	switch (cmd) {
487 	case SIOCSIFMTU:
488 	case SIOCSLIFPHYADDR:
489 #ifdef SIOCDIFPHYADDR
490 	case SIOCDIFPHYADDR:
491 #endif
492 		if ((error = kauth_authorize_network(l->l_cred,
493 		    KAUTH_NETWORK_INTERFACE,
494 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
495 		    NULL)) != 0)
496 			return (error);
497 		/* FALLTHROUGH */
498 	default:
499 		break;
500 	}
501 
502 	switch (cmd) {
503 	case SIOCINITIFADDR:
504 		ifp->if_flags |= IFF_UP;
505 		break;
506 
507 	case SIOCSIFDSTADDR:
508 		break;
509 
510 	case SIOCADDMULTI:
511 	case SIOCDELMULTI:
512 		switch (ifr->ifr_addr.sa_family) {
513 #ifdef INET
514 		case AF_INET:	/* IP supports Multicast */
515 			break;
516 #endif /* INET */
517 #ifdef INET6
518 		case AF_INET6:	/* IP6 supports Multicast */
519 			break;
520 #endif /* INET6 */
521 		default:  /* Other protocols doesn't support Multicast */
522 			error = EAFNOSUPPORT;
523 			break;
524 		}
525 		break;
526 
527 	case SIOCGIFMTU:
528 		break;
529 
530 	case SIOCSIFMTU:
531 		if (ifr->ifr_mtu < GIF_MTU_MIN || ifr->ifr_mtu > GIF_MTU_MAX)
532 			return EINVAL;
533 		else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
534 			error = 0;
535 		break;
536 
537 #ifdef INET
538 	case SIOCSIFPHYADDR:
539 #endif
540 #ifdef INET6
541 	case SIOCSIFPHYADDR_IN6:
542 #endif /* INET6 */
543 	case SIOCSLIFPHYADDR:
544 		switch (cmd) {
545 #ifdef INET
546 		case SIOCSIFPHYADDR:
547 			src = (struct sockaddr *)
548 				&(((struct in_aliasreq *)data)->ifra_addr);
549 			dst = (struct sockaddr *)
550 				&(((struct in_aliasreq *)data)->ifra_dstaddr);
551 			break;
552 #endif
553 #ifdef INET6
554 		case SIOCSIFPHYADDR_IN6:
555 			src = (struct sockaddr *)
556 				&(((struct in6_aliasreq *)data)->ifra_addr);
557 			dst = (struct sockaddr *)
558 				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
559 			break;
560 #endif
561 		case SIOCSLIFPHYADDR:
562 			src = (struct sockaddr *)
563 				&(((struct if_laddrreq *)data)->addr);
564 			dst = (struct sockaddr *)
565 				&(((struct if_laddrreq *)data)->dstaddr);
566 			break;
567 		default:
568 			return EINVAL;
569 		}
570 
571 		/* sa_family must be equal */
572 		if (src->sa_family != dst->sa_family)
573 			return EINVAL;
574 
575 		/* validate sa_len */
576 		switch (src->sa_family) {
577 #ifdef INET
578 		case AF_INET:
579 			if (src->sa_len != sizeof(struct sockaddr_in))
580 				return EINVAL;
581 			break;
582 #endif
583 #ifdef INET6
584 		case AF_INET6:
585 			if (src->sa_len != sizeof(struct sockaddr_in6))
586 				return EINVAL;
587 			break;
588 #endif
589 		default:
590 			return EAFNOSUPPORT;
591 		}
592 		switch (dst->sa_family) {
593 #ifdef INET
594 		case AF_INET:
595 			if (dst->sa_len != sizeof(struct sockaddr_in))
596 				return EINVAL;
597 			break;
598 #endif
599 #ifdef INET6
600 		case AF_INET6:
601 			if (dst->sa_len != sizeof(struct sockaddr_in6))
602 				return EINVAL;
603 			break;
604 #endif
605 		default:
606 			return EAFNOSUPPORT;
607 		}
608 
609 		/* check sa_family looks sane for the cmd */
610 		switch (cmd) {
611 		case SIOCSIFPHYADDR:
612 			if (src->sa_family == AF_INET)
613 				break;
614 			return EAFNOSUPPORT;
615 #ifdef INET6
616 		case SIOCSIFPHYADDR_IN6:
617 			if (src->sa_family == AF_INET6)
618 				break;
619 			return EAFNOSUPPORT;
620 #endif /* INET6 */
621 		case SIOCSLIFPHYADDR:
622 			/* checks done in the above */
623 			break;
624 		}
625 
626 		error = gif_set_tunnel(&sc->gif_if, src, dst);
627 		break;
628 
629 #ifdef SIOCDIFPHYADDR
630 	case SIOCDIFPHYADDR:
631 		gif_delete_tunnel(&sc->gif_if);
632 		break;
633 #endif
634 
635 	case SIOCGIFPSRCADDR:
636 #ifdef INET6
637 	case SIOCGIFPSRCADDR_IN6:
638 #endif /* INET6 */
639 		if (sc->gif_psrc == NULL) {
640 			error = EADDRNOTAVAIL;
641 			goto bad;
642 		}
643 		src = sc->gif_psrc;
644 		switch (cmd) {
645 #ifdef INET
646 		case SIOCGIFPSRCADDR:
647 			dst = &ifr->ifr_addr;
648 			size = sizeof(ifr->ifr_addr);
649 			break;
650 #endif /* INET */
651 #ifdef INET6
652 		case SIOCGIFPSRCADDR_IN6:
653 			dst = (struct sockaddr *)
654 				&(((struct in6_ifreq *)data)->ifr_addr);
655 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
656 			break;
657 #endif /* INET6 */
658 		default:
659 			error = EADDRNOTAVAIL;
660 			goto bad;
661 		}
662 		if (src->sa_len > size)
663 			return EINVAL;
664 		memcpy(dst, src, src->sa_len);
665 		break;
666 
667 	case SIOCGIFPDSTADDR:
668 #ifdef INET6
669 	case SIOCGIFPDSTADDR_IN6:
670 #endif /* INET6 */
671 		if (sc->gif_pdst == NULL) {
672 			error = EADDRNOTAVAIL;
673 			goto bad;
674 		}
675 		src = sc->gif_pdst;
676 		switch (cmd) {
677 #ifdef INET
678 		case SIOCGIFPDSTADDR:
679 			dst = &ifr->ifr_addr;
680 			size = sizeof(ifr->ifr_addr);
681 			break;
682 #endif /* INET */
683 #ifdef INET6
684 		case SIOCGIFPDSTADDR_IN6:
685 			dst = (struct sockaddr *)
686 				&(((struct in6_ifreq *)data)->ifr_addr);
687 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
688 			break;
689 #endif /* INET6 */
690 		default:
691 			error = EADDRNOTAVAIL;
692 			goto bad;
693 		}
694 		if (src->sa_len > size)
695 			return EINVAL;
696 		memcpy(dst, src, src->sa_len);
697 		break;
698 
699 	case SIOCGLIFPHYADDR:
700 		if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
701 			error = EADDRNOTAVAIL;
702 			goto bad;
703 		}
704 
705 		/* copy src */
706 		src = sc->gif_psrc;
707 		dst = (struct sockaddr *)
708 			&(((struct if_laddrreq *)data)->addr);
709 		size = sizeof(((struct if_laddrreq *)data)->addr);
710 		if (src->sa_len > size)
711 			return EINVAL;
712 		memcpy(dst, src, src->sa_len);
713 
714 		/* copy dst */
715 		src = sc->gif_pdst;
716 		dst = (struct sockaddr *)
717 			&(((struct if_laddrreq *)data)->dstaddr);
718 		size = sizeof(((struct if_laddrreq *)data)->dstaddr);
719 		if (src->sa_len > size)
720 			return EINVAL;
721 		memcpy(dst, src, src->sa_len);
722 		break;
723 
724 	default:
725 		return ifioctl_common(ifp, cmd, data);
726 	}
727  bad:
728 	return error;
729 }
730 
731 int
732 gif_set_tunnel(struct ifnet *ifp, struct sockaddr *src, struct sockaddr *dst)
733 {
734 	struct gif_softc *sc = ifp->if_softc;
735 	struct gif_softc *sc2;
736 	struct sockaddr *osrc, *odst;
737 	int s;
738 	int error;
739 
740 	s = splsoftnet();
741 
742 	LIST_FOREACH(sc2, &gif_softc_list, gif_list) {
743 		if (sc2 == sc)
744 			continue;
745 		if (!sc2->gif_pdst || !sc2->gif_psrc)
746 			continue;
747 		/* can't configure same pair of address onto two gifs */
748 		if (sockaddr_cmp(sc2->gif_pdst, dst) == 0 &&
749 		    sockaddr_cmp(sc2->gif_psrc, src) == 0) {
750 			error = EADDRNOTAVAIL;
751 			goto bad;
752 		}
753 
754 		/* XXX both end must be valid? (I mean, not 0.0.0.0) */
755 	}
756 
757 	if (sc->gif_si) {
758 		softint_disestablish(sc->gif_si);
759 		sc->gif_si = NULL;
760 	}
761 
762 	/* XXX we can detach from both, but be polite just in case */
763 	if (sc->gif_psrc)
764 		switch (sc->gif_psrc->sa_family) {
765 #ifdef INET
766 		case AF_INET:
767 			(void)in_gif_detach(sc);
768 			break;
769 #endif
770 #ifdef INET6
771 		case AF_INET6:
772 			(void)in6_gif_detach(sc);
773 			break;
774 #endif
775 		}
776 
777 	sc->gif_si = softint_establish(SOFTINT_NET, gifintr, sc);
778 	if (sc->gif_si == NULL) {
779 		error = ENOMEM;
780 		goto bad;
781 	}
782 
783 	osrc = sc->gif_psrc;
784 	sc->gif_psrc = sockaddr_dup(src, M_WAITOK);
785 
786 	odst = sc->gif_pdst;
787 	sc->gif_pdst = sockaddr_dup(dst, M_WAITOK);
788 
789 	switch (sc->gif_psrc->sa_family) {
790 #ifdef INET
791 	case AF_INET:
792 		error = in_gif_attach(sc);
793 		break;
794 #endif
795 #ifdef INET6
796 	case AF_INET6:
797 		error = in6_gif_attach(sc);
798 		break;
799 #endif
800 	default:
801 		error = EINVAL;
802 		break;
803 	}
804 	if (error) {
805 		/* rollback */
806 		sockaddr_free(sc->gif_psrc);
807 		sockaddr_free(sc->gif_pdst);
808 		sc->gif_psrc = osrc;
809 		sc->gif_pdst = odst;
810 		goto bad;
811 	}
812 
813 	if (osrc)
814 		sockaddr_free(osrc);
815 	if (odst)
816 		sockaddr_free(odst);
817 
818 	if (sc->gif_psrc && sc->gif_pdst)
819 		ifp->if_flags |= IFF_RUNNING;
820 	else
821 		ifp->if_flags &= ~IFF_RUNNING;
822 	splx(s);
823 
824 	return 0;
825 
826  bad:
827 	if (sc->gif_si) {
828 		softint_disestablish(sc->gif_si);
829 		sc->gif_si = NULL;
830 	}
831 	if (sc->gif_psrc && sc->gif_pdst)
832 		ifp->if_flags |= IFF_RUNNING;
833 	else
834 		ifp->if_flags &= ~IFF_RUNNING;
835 	splx(s);
836 
837 	return error;
838 }
839 
840 void
841 gif_delete_tunnel(struct ifnet *ifp)
842 {
843 	struct gif_softc *sc = ifp->if_softc;
844 	int s;
845 
846 	s = splsoftnet();
847 
848 	if (sc->gif_si) {
849 		softint_disestablish(sc->gif_si);
850 		sc->gif_si = NULL;
851 	}
852 	if (sc->gif_psrc) {
853 		sockaddr_free(sc->gif_psrc);
854 		sc->gif_psrc = NULL;
855 	}
856 	if (sc->gif_pdst) {
857 		sockaddr_free(sc->gif_pdst);
858 		sc->gif_pdst = NULL;
859 	}
860 	/* it is safe to detach from both */
861 #ifdef INET
862 	(void)in_gif_detach(sc);
863 #endif
864 #ifdef INET6
865 	(void)in6_gif_detach(sc);
866 #endif
867 
868 	if (sc->gif_psrc && sc->gif_pdst)
869 		ifp->if_flags |= IFF_RUNNING;
870 	else
871 		ifp->if_flags &= ~IFF_RUNNING;
872 	splx(s);
873 }
874 
875 #ifdef ISO
876 struct eonhdr {
877 	uint8_t version;
878 	uint8_t class;
879 	uint16_t cksum;
880 };
881 
882 /*
883  * prepend EON header to ISO PDU
884  */
885 static struct mbuf *
886 gif_eon_encap(struct mbuf *m)
887 {
888 	struct eonhdr *ehdr;
889 
890 	M_PREPEND(m, sizeof(*ehdr), M_DONTWAIT);
891 	if (m && m->m_len < sizeof(*ehdr))
892 		m = m_pullup(m, sizeof(*ehdr));
893 	if (m == NULL)
894 		return NULL;
895 	ehdr = mtod(m, struct eonhdr *);
896 	ehdr->version = 1;
897 	ehdr->class = 0;		/* always unicast */
898 #if 0
899 	/* calculate the checksum of the eonhdr */
900 	{
901 		struct mbuf mhead;
902 		memset(&mhead, 0, sizeof(mhead));
903 		ehdr->cksum = 0;
904 		mhead.m_data = (void *)ehdr;
905 		mhead.m_len = sizeof(*ehdr);
906 		mhead.m_next = 0;
907 		iso_gen_csum(&mhead, offsetof(struct eonhdr, cksum),
908 		    mhead.m_len);
909 	}
910 #else
911 	/* since the data is always constant we'll just plug the value in */
912 	ehdr->cksum = htons(0xfc02);
913 #endif
914 	return m;
915 }
916 
917 /*
918  * remove EON header and check checksum
919  */
920 static struct mbuf *
921 gif_eon_decap(struct ifnet *ifp, struct mbuf *m)
922 {
923 	struct eonhdr *ehdr;
924 
925 	if (m->m_len < sizeof(*ehdr) &&
926 	    (m = m_pullup(m, sizeof(*ehdr))) == NULL) {
927 		ifp->if_ierrors++;
928 		return NULL;
929 	}
930 	if (iso_check_csum(m, sizeof(struct eonhdr))) {
931 		m_freem(m);
932 		return NULL;
933 	}
934 	m_adj(m, sizeof(*ehdr));
935 	return m;
936 }
937 #endif /*ISO*/
938