xref: /netbsd-src/sys/net/if_gif.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: if_gif.c,v 1.78 2010/04/05 07:22:23 joerg 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 1.78 2010/04/05 07:22:23 joerg 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 
89 #include <net/net_osdep.h>
90 
91 void	gifattach(int);
92 static void	gifintr(void *);
93 #ifdef ISO
94 static struct mbuf *gif_eon_encap(struct mbuf *);
95 static struct mbuf *gif_eon_decap(struct ifnet *, struct mbuf *);
96 #endif
97 
98 /*
99  * gif global variable definitions
100  */
101 LIST_HEAD(, gif_softc) gif_softc_list;	/* XXX should be static */
102 
103 static int	gif_clone_create(struct if_clone *, int);
104 static int	gif_clone_destroy(struct ifnet *);
105 
106 static struct if_clone gif_cloner =
107     IF_CLONE_INITIALIZER("gif", gif_clone_create, gif_clone_destroy);
108 
109 #ifndef MAX_GIF_NEST
110 /*
111  * This macro controls the upper limitation on nesting of gif tunnels.
112  * Since, setting a large value to this macro with a careless configuration
113  * may introduce system crash, we don't allow any nestings by default.
114  * If you need to configure nested gif tunnels, you can define this macro
115  * in your kernel configuration file.  However, if you do so, please be
116  * careful to configure the tunnels so that it won't make a loop.
117  */
118 #define MAX_GIF_NEST 1
119 #endif
120 static int max_gif_nesting = MAX_GIF_NEST;
121 
122 /* ARGSUSED */
123 void
124 gifattach(int count)
125 {
126 
127 	LIST_INIT(&gif_softc_list);
128 	if_clone_attach(&gif_cloner);
129 }
130 
131 static int
132 gif_clone_create(struct if_clone *ifc, int unit)
133 {
134 	struct gif_softc *sc;
135 
136 	sc = malloc(sizeof(struct gif_softc), M_DEVBUF, M_WAITOK|M_ZERO);
137 
138 	if_initname(&sc->gif_if, ifc->ifc_name, unit);
139 
140 	gifattach0(sc);
141 
142 	LIST_INSERT_HEAD(&gif_softc_list, sc, gif_list);
143 	return (0);
144 }
145 
146 void
147 gifattach0(struct gif_softc *sc)
148 {
149 
150 	sc->encap_cookie4 = sc->encap_cookie6 = NULL;
151 
152 	sc->gif_if.if_addrlen = 0;
153 	sc->gif_if.if_mtu    = GIF_MTU;
154 	sc->gif_if.if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
155 	sc->gif_if.if_ioctl  = gif_ioctl;
156 	sc->gif_if.if_output = gif_output;
157 	sc->gif_if.if_type   = IFT_GIF;
158 	sc->gif_if.if_dlt    = DLT_NULL;
159 	sc->gif_if.if_softc  = sc;
160 	IFQ_SET_READY(&sc->gif_if.if_snd);
161 	if_attach(&sc->gif_if);
162 	if_alloc_sadl(&sc->gif_if);
163 	bpf_attach(&sc->gif_if, DLT_NULL, sizeof(u_int));
164 }
165 
166 static int
167 gif_clone_destroy(struct ifnet *ifp)
168 {
169 	struct gif_softc *sc = (void *) ifp;
170 
171 	gif_delete_tunnel(&sc->gif_if);
172 	LIST_REMOVE(sc, gif_list);
173 #ifdef INET6
174 	encap_detach(sc->encap_cookie6);
175 #endif
176 #ifdef INET
177 	encap_detach(sc->encap_cookie4);
178 #endif
179 
180 	bpf_detach(ifp);
181 	if_detach(ifp);
182 	rtcache_free(&sc->gif_ro);
183 
184 	free(sc, M_DEVBUF);
185 
186 	return (0);
187 }
188 
189 #ifdef GIF_ENCAPCHECK
190 int
191 gif_encapcheck(struct mbuf *m, int off, int proto, void *arg)
192 {
193 	struct ip ip;
194 	struct gif_softc *sc;
195 
196 	sc = arg;
197 	if (sc == NULL)
198 		return 0;
199 
200 	if ((sc->gif_if.if_flags & IFF_UP) == 0)
201 		return 0;
202 
203 	/* no physical address */
204 	if (!sc->gif_psrc || !sc->gif_pdst)
205 		return 0;
206 
207 	switch (proto) {
208 #ifdef INET
209 	case IPPROTO_IPV4:
210 		break;
211 #endif
212 #ifdef INET6
213 	case IPPROTO_IPV6:
214 		break;
215 #endif
216 #ifdef ISO
217 	case IPPROTO_EON:
218 		break;
219 #endif
220 	default:
221 		return 0;
222 	}
223 
224 	/* Bail on short packets */
225 	KASSERT(m->m_flags & M_PKTHDR);
226 	if (m->m_pkthdr.len < sizeof(ip))
227 		return 0;
228 
229 	m_copydata(m, 0, sizeof(ip), &ip);
230 
231 	switch (ip.ip_v) {
232 #ifdef INET
233 	case 4:
234 		if (sc->gif_psrc->sa_family != AF_INET ||
235 		    sc->gif_pdst->sa_family != AF_INET)
236 			return 0;
237 		return gif_encapcheck4(m, off, proto, arg);
238 #endif
239 #ifdef INET6
240 	case 6:
241 		if (m->m_pkthdr.len < sizeof(struct ip6_hdr))
242 			return 0;
243 		if (sc->gif_psrc->sa_family != AF_INET6 ||
244 		    sc->gif_pdst->sa_family != AF_INET6)
245 			return 0;
246 		return gif_encapcheck6(m, off, proto, arg);
247 #endif
248 	default:
249 		return 0;
250 	}
251 }
252 #endif
253 
254 int
255 gif_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
256     struct rtentry *rt)
257 {
258 	struct gif_softc *sc = ifp->if_softc;
259 	int error = 0;
260 	static int called = 0;	/* XXX: MUTEX */
261 	ALTQ_DECL(struct altq_pktattr pktattr;)
262 	int s;
263 
264 	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
265 
266 	/*
267 	 * gif may cause infinite recursion calls when misconfigured.
268 	 * We'll prevent this by introducing upper limit.
269 	 * XXX: this mechanism may introduce another problem about
270 	 *      mutual exclusion of the variable CALLED, especially if we
271 	 *      use kernel thread.
272 	 */
273 	if (++called > max_gif_nesting) {
274 		log(LOG_NOTICE,
275 		    "gif_output: recursively called too many times(%d)\n",
276 		    called);
277 		m_freem(m);
278 		error = EIO;	/* is there better errno? */
279 		goto end;
280 	}
281 
282 	m->m_flags &= ~(M_BCAST|M_MCAST);
283 	if (!(ifp->if_flags & IFF_UP) ||
284 	    sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
285 		m_freem(m);
286 		error = ENETDOWN;
287 		goto end;
288 	}
289 
290 	/* inner AF-specific encapsulation */
291 	switch (dst->sa_family) {
292 #ifdef ISO
293 	case AF_ISO:
294 		m = gif_eon_encap(m);
295 		if (!m) {
296 			error = ENOBUFS;
297 			goto end;
298 		}
299 		break;
300 #endif
301 	default:
302 		break;
303 	}
304 
305 	/* XXX should we check if our outer source is legal? */
306 
307 	/* use DLT_NULL encapsulation here to pass inner af type */
308 	M_PREPEND(m, sizeof(int), M_DONTWAIT);
309 	if (!m) {
310 		error = ENOBUFS;
311 		goto end;
312 	}
313 	*mtod(m, int *) = dst->sa_family;
314 
315 	s = splnet();
316 	IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
317 	if (error) {
318 		splx(s);
319 		goto end;
320 	}
321 	splx(s);
322 
323 	softint_schedule(sc->gif_si);
324 	error = 0;
325 
326   end:
327 	called = 0;		/* reset recursion counter */
328 	if (error)
329 		ifp->if_oerrors++;
330 	return error;
331 }
332 
333 static void
334 gifintr(void *arg)
335 {
336 	struct gif_softc *sc;
337 	struct ifnet *ifp;
338 	struct mbuf *m;
339 	int family;
340 	int len;
341 	int s;
342 	int error;
343 
344 	sc = arg;
345 	ifp = &sc->gif_if;
346 
347 	/* output processing */
348 	while (1) {
349 		s = splnet();
350 		IFQ_DEQUEUE(&sc->gif_if.if_snd, m);
351 		splx(s);
352 		if (m == NULL)
353 			break;
354 
355 		/* grab and chop off inner af type */
356 		if (sizeof(int) > m->m_len) {
357 			m = m_pullup(m, sizeof(int));
358 			if (!m) {
359 				ifp->if_oerrors++;
360 				continue;
361 			}
362 		}
363 		family = *mtod(m, int *);
364 		bpf_mtap(ifp, m);
365 		m_adj(m, sizeof(int));
366 
367 		len = m->m_pkthdr.len;
368 
369 		/* dispatch to output logic based on outer AF */
370 		switch (sc->gif_psrc->sa_family) {
371 #ifdef INET
372 		case AF_INET:
373 			error = in_gif_output(ifp, family, m);
374 			break;
375 #endif
376 #ifdef INET6
377 		case AF_INET6:
378 			error = in6_gif_output(ifp, family, m);
379 			break;
380 #endif
381 		default:
382 			m_freem(m);
383 			error = ENETDOWN;
384 			break;
385 		}
386 
387 		if (error)
388 			ifp->if_oerrors++;
389 		else {
390 			ifp->if_opackets++;
391 			ifp->if_obytes += len;
392 		}
393 	}
394 }
395 
396 void
397 gif_input(struct mbuf *m, int af, struct ifnet *ifp)
398 {
399 	int s, isr;
400 	struct ifqueue *ifq = NULL;
401 
402 	if (ifp == NULL) {
403 		/* just in case */
404 		m_freem(m);
405 		return;
406 	}
407 
408 	m->m_pkthdr.rcvif = ifp;
409 
410 	bpf_mtap_af(ifp, af, m);
411 
412 	/*
413 	 * Put the packet to the network layer input queue according to the
414 	 * specified address family.
415 	 * Note: older versions of gif_input directly called network layer
416 	 * input functions, e.g. ip6_input, here.  We changed the policy to
417 	 * prevent too many recursive calls of such input functions, which
418 	 * might cause kernel panic.  But the change may introduce another
419 	 * problem; if the input queue is full, packets are discarded.
420 	 * The kernel stack overflow really happened, and we believed
421 	 * queue-full rarely occurs, so we changed the policy.
422 	 */
423 	switch (af) {
424 #ifdef INET
425 	case AF_INET:
426 		ifq = &ipintrq;
427 		isr = NETISR_IP;
428 		break;
429 #endif
430 #ifdef INET6
431 	case AF_INET6:
432 		ifq = &ip6intrq;
433 		isr = NETISR_IPV6;
434 		break;
435 #endif
436 #ifdef ISO
437 	case AF_ISO:
438 		m = gif_eon_decap(ifp, m);
439 		if (!m)
440 			return;
441 		ifq = &clnlintrq;
442 		isr = NETISR_ISO;
443 		break;
444 #endif
445 	default:
446 		m_freem(m);
447 		return;
448 	}
449 
450 	s = splnet();
451 	if (IF_QFULL(ifq)) {
452 		IF_DROP(ifq);	/* update statistics */
453 		m_freem(m);
454 		splx(s);
455 		return;
456 	}
457 	ifp->if_ipackets++;
458 	ifp->if_ibytes += m->m_pkthdr.len;
459 	IF_ENQUEUE(ifq, m);
460 	/* we need schednetisr since the address family may change */
461 	schednetisr(isr);
462 	splx(s);
463 }
464 
465 /* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
466 int
467 gif_ioctl(struct ifnet *ifp, u_long cmd, void *data)
468 {
469 	struct lwp *l = curlwp;	/* XXX */
470 	struct gif_softc *sc  = ifp->if_softc;
471 	struct ifreq     *ifr = (struct ifreq*)data;
472 	int error = 0, size;
473 	struct sockaddr *dst, *src;
474 
475 	switch (cmd) {
476 	case SIOCSIFMTU:
477 	case SIOCSLIFPHYADDR:
478 #ifdef SIOCDIFPHYADDR
479 	case SIOCDIFPHYADDR:
480 #endif
481 		if ((error = kauth_authorize_network(l->l_cred,
482 		    KAUTH_NETWORK_INTERFACE,
483 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
484 		    NULL)) != 0)
485 			return (error);
486 		/* FALLTHROUGH */
487 	default:
488 		break;
489 	}
490 
491 	switch (cmd) {
492 	case SIOCINITIFADDR:
493 		ifp->if_flags |= IFF_UP;
494 		break;
495 
496 	case SIOCSIFDSTADDR:
497 		break;
498 
499 	case SIOCADDMULTI:
500 	case SIOCDELMULTI:
501 		switch (ifr->ifr_addr.sa_family) {
502 #ifdef INET
503 		case AF_INET:	/* IP supports Multicast */
504 			break;
505 #endif /* INET */
506 #ifdef INET6
507 		case AF_INET6:	/* IP6 supports Multicast */
508 			break;
509 #endif /* INET6 */
510 		default:  /* Other protocols doesn't support Multicast */
511 			error = EAFNOSUPPORT;
512 			break;
513 		}
514 		break;
515 
516 	case SIOCGIFMTU:
517 		break;
518 
519 	case SIOCSIFMTU:
520 		if (ifr->ifr_mtu < GIF_MTU_MIN || ifr->ifr_mtu > GIF_MTU_MAX)
521 			return EINVAL;
522 		else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
523 			error = 0;
524 		break;
525 
526 #ifdef INET
527 	case SIOCSIFPHYADDR:
528 #endif
529 #ifdef INET6
530 	case SIOCSIFPHYADDR_IN6:
531 #endif /* INET6 */
532 	case SIOCSLIFPHYADDR:
533 		switch (cmd) {
534 #ifdef INET
535 		case SIOCSIFPHYADDR:
536 			src = (struct sockaddr *)
537 				&(((struct in_aliasreq *)data)->ifra_addr);
538 			dst = (struct sockaddr *)
539 				&(((struct in_aliasreq *)data)->ifra_dstaddr);
540 			break;
541 #endif
542 #ifdef INET6
543 		case SIOCSIFPHYADDR_IN6:
544 			src = (struct sockaddr *)
545 				&(((struct in6_aliasreq *)data)->ifra_addr);
546 			dst = (struct sockaddr *)
547 				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
548 			break;
549 #endif
550 		case SIOCSLIFPHYADDR:
551 			src = (struct sockaddr *)
552 				&(((struct if_laddrreq *)data)->addr);
553 			dst = (struct sockaddr *)
554 				&(((struct if_laddrreq *)data)->dstaddr);
555 			break;
556 		default:
557 			return EINVAL;
558 		}
559 
560 		/* sa_family must be equal */
561 		if (src->sa_family != dst->sa_family)
562 			return EINVAL;
563 
564 		/* validate sa_len */
565 		switch (src->sa_family) {
566 #ifdef INET
567 		case AF_INET:
568 			if (src->sa_len != sizeof(struct sockaddr_in))
569 				return EINVAL;
570 			break;
571 #endif
572 #ifdef INET6
573 		case AF_INET6:
574 			if (src->sa_len != sizeof(struct sockaddr_in6))
575 				return EINVAL;
576 			break;
577 #endif
578 		default:
579 			return EAFNOSUPPORT;
580 		}
581 		switch (dst->sa_family) {
582 #ifdef INET
583 		case AF_INET:
584 			if (dst->sa_len != sizeof(struct sockaddr_in))
585 				return EINVAL;
586 			break;
587 #endif
588 #ifdef INET6
589 		case AF_INET6:
590 			if (dst->sa_len != sizeof(struct sockaddr_in6))
591 				return EINVAL;
592 			break;
593 #endif
594 		default:
595 			return EAFNOSUPPORT;
596 		}
597 
598 		/* check sa_family looks sane for the cmd */
599 		switch (cmd) {
600 		case SIOCSIFPHYADDR:
601 			if (src->sa_family == AF_INET)
602 				break;
603 			return EAFNOSUPPORT;
604 #ifdef INET6
605 		case SIOCSIFPHYADDR_IN6:
606 			if (src->sa_family == AF_INET6)
607 				break;
608 			return EAFNOSUPPORT;
609 #endif /* INET6 */
610 		case SIOCSLIFPHYADDR:
611 			/* checks done in the above */
612 			break;
613 		}
614 
615 		error = gif_set_tunnel(&sc->gif_if, src, dst);
616 		break;
617 
618 #ifdef SIOCDIFPHYADDR
619 	case SIOCDIFPHYADDR:
620 		gif_delete_tunnel(&sc->gif_if);
621 		break;
622 #endif
623 
624 	case SIOCGIFPSRCADDR:
625 #ifdef INET6
626 	case SIOCGIFPSRCADDR_IN6:
627 #endif /* INET6 */
628 		if (sc->gif_psrc == NULL) {
629 			error = EADDRNOTAVAIL;
630 			goto bad;
631 		}
632 		src = sc->gif_psrc;
633 		switch (cmd) {
634 #ifdef INET
635 		case SIOCGIFPSRCADDR:
636 			dst = &ifr->ifr_addr;
637 			size = sizeof(ifr->ifr_addr);
638 			break;
639 #endif /* INET */
640 #ifdef INET6
641 		case SIOCGIFPSRCADDR_IN6:
642 			dst = (struct sockaddr *)
643 				&(((struct in6_ifreq *)data)->ifr_addr);
644 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
645 			break;
646 #endif /* INET6 */
647 		default:
648 			error = EADDRNOTAVAIL;
649 			goto bad;
650 		}
651 		if (src->sa_len > size)
652 			return EINVAL;
653 		memcpy(dst, src, src->sa_len);
654 		break;
655 
656 	case SIOCGIFPDSTADDR:
657 #ifdef INET6
658 	case SIOCGIFPDSTADDR_IN6:
659 #endif /* INET6 */
660 		if (sc->gif_pdst == NULL) {
661 			error = EADDRNOTAVAIL;
662 			goto bad;
663 		}
664 		src = sc->gif_pdst;
665 		switch (cmd) {
666 #ifdef INET
667 		case SIOCGIFPDSTADDR:
668 			dst = &ifr->ifr_addr;
669 			size = sizeof(ifr->ifr_addr);
670 			break;
671 #endif /* INET */
672 #ifdef INET6
673 		case SIOCGIFPDSTADDR_IN6:
674 			dst = (struct sockaddr *)
675 				&(((struct in6_ifreq *)data)->ifr_addr);
676 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
677 			break;
678 #endif /* INET6 */
679 		default:
680 			error = EADDRNOTAVAIL;
681 			goto bad;
682 		}
683 		if (src->sa_len > size)
684 			return EINVAL;
685 		memcpy(dst, src, src->sa_len);
686 		break;
687 
688 	case SIOCGLIFPHYADDR:
689 		if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
690 			error = EADDRNOTAVAIL;
691 			goto bad;
692 		}
693 
694 		/* copy src */
695 		src = sc->gif_psrc;
696 		dst = (struct sockaddr *)
697 			&(((struct if_laddrreq *)data)->addr);
698 		size = sizeof(((struct if_laddrreq *)data)->addr);
699 		if (src->sa_len > size)
700 			return EINVAL;
701 		memcpy(dst, src, src->sa_len);
702 
703 		/* copy dst */
704 		src = sc->gif_pdst;
705 		dst = (struct sockaddr *)
706 			&(((struct if_laddrreq *)data)->dstaddr);
707 		size = sizeof(((struct if_laddrreq *)data)->dstaddr);
708 		if (src->sa_len > size)
709 			return EINVAL;
710 		memcpy(dst, src, src->sa_len);
711 		break;
712 
713 	default:
714 		return ifioctl_common(ifp, cmd, data);
715 	}
716  bad:
717 	return error;
718 }
719 
720 int
721 gif_set_tunnel(struct ifnet *ifp, struct sockaddr *src, struct sockaddr *dst)
722 {
723 	struct gif_softc *sc = ifp->if_softc;
724 	struct gif_softc *sc2;
725 	struct sockaddr *osrc, *odst;
726 	int s;
727 	int error;
728 
729 	s = splsoftnet();
730 
731 	LIST_FOREACH(sc2, &gif_softc_list, gif_list) {
732 		if (sc2 == sc)
733 			continue;
734 		if (!sc2->gif_pdst || !sc2->gif_psrc)
735 			continue;
736 		/* can't configure same pair of address onto two gifs */
737 		if (sockaddr_cmp(sc2->gif_pdst, dst) == 0 &&
738 		    sockaddr_cmp(sc2->gif_psrc, src) == 0) {
739 			error = EADDRNOTAVAIL;
740 			goto bad;
741 		}
742 
743 		/* XXX both end must be valid? (I mean, not 0.0.0.0) */
744 	}
745 
746 	if (sc->gif_si) {
747 		softint_disestablish(sc->gif_si);
748 		sc->gif_si = NULL;
749 	}
750 
751 	/* XXX we can detach from both, but be polite just in case */
752 	if (sc->gif_psrc)
753 		switch (sc->gif_psrc->sa_family) {
754 #ifdef INET
755 		case AF_INET:
756 			(void)in_gif_detach(sc);
757 			break;
758 #endif
759 #ifdef INET6
760 		case AF_INET6:
761 			(void)in6_gif_detach(sc);
762 			break;
763 #endif
764 		}
765 
766 	sc->gif_si = softint_establish(SOFTINT_NET, gifintr, sc);
767 	if (sc->gif_si == NULL) {
768 		error = ENOMEM;
769 		goto bad;
770 	}
771 
772 	osrc = sc->gif_psrc;
773 	sc->gif_psrc = sockaddr_dup(src, M_WAITOK);
774 
775 	odst = sc->gif_pdst;
776 	sc->gif_pdst = sockaddr_dup(dst, M_WAITOK);
777 
778 	switch (sc->gif_psrc->sa_family) {
779 #ifdef INET
780 	case AF_INET:
781 		error = in_gif_attach(sc);
782 		break;
783 #endif
784 #ifdef INET6
785 	case AF_INET6:
786 		error = in6_gif_attach(sc);
787 		break;
788 #endif
789 	default:
790 		error = EINVAL;
791 		break;
792 	}
793 	if (error) {
794 		/* rollback */
795 		sockaddr_free(sc->gif_psrc);
796 		sockaddr_free(sc->gif_pdst);
797 		sc->gif_psrc = osrc;
798 		sc->gif_pdst = odst;
799 		goto bad;
800 	}
801 
802 	if (osrc)
803 		sockaddr_free(osrc);
804 	if (odst)
805 		sockaddr_free(odst);
806 
807 	if (sc->gif_psrc && sc->gif_pdst)
808 		ifp->if_flags |= IFF_RUNNING;
809 	else
810 		ifp->if_flags &= ~IFF_RUNNING;
811 	splx(s);
812 
813 	return 0;
814 
815  bad:
816 	if (sc->gif_si) {
817 		softint_disestablish(sc->gif_si);
818 		sc->gif_si = NULL;
819 	}
820 	if (sc->gif_psrc && sc->gif_pdst)
821 		ifp->if_flags |= IFF_RUNNING;
822 	else
823 		ifp->if_flags &= ~IFF_RUNNING;
824 	splx(s);
825 
826 	return error;
827 }
828 
829 void
830 gif_delete_tunnel(struct ifnet *ifp)
831 {
832 	struct gif_softc *sc = ifp->if_softc;
833 	int s;
834 
835 	s = splsoftnet();
836 
837 	if (sc->gif_si) {
838 		softint_disestablish(sc->gif_si);
839 		sc->gif_si = NULL;
840 	}
841 	if (sc->gif_psrc) {
842 		sockaddr_free(sc->gif_psrc);
843 		sc->gif_psrc = NULL;
844 	}
845 	if (sc->gif_pdst) {
846 		sockaddr_free(sc->gif_pdst);
847 		sc->gif_pdst = NULL;
848 	}
849 	/* it is safe to detach from both */
850 #ifdef INET
851 	(void)in_gif_detach(sc);
852 #endif
853 #ifdef INET6
854 	(void)in6_gif_detach(sc);
855 #endif
856 
857 	if (sc->gif_psrc && sc->gif_pdst)
858 		ifp->if_flags |= IFF_RUNNING;
859 	else
860 		ifp->if_flags &= ~IFF_RUNNING;
861 	splx(s);
862 }
863 
864 #ifdef ISO
865 struct eonhdr {
866 	uint8_t version;
867 	uint8_t class;
868 	uint16_t cksum;
869 };
870 
871 /*
872  * prepend EON header to ISO PDU
873  */
874 static struct mbuf *
875 gif_eon_encap(struct mbuf *m)
876 {
877 	struct eonhdr *ehdr;
878 
879 	M_PREPEND(m, sizeof(*ehdr), M_DONTWAIT);
880 	if (m && m->m_len < sizeof(*ehdr))
881 		m = m_pullup(m, sizeof(*ehdr));
882 	if (m == NULL)
883 		return NULL;
884 	ehdr = mtod(m, struct eonhdr *);
885 	ehdr->version = 1;
886 	ehdr->class = 0;		/* always unicast */
887 #if 0
888 	/* calculate the checksum of the eonhdr */
889 	{
890 		struct mbuf mhead;
891 		memset(&mhead, 0, sizeof(mhead));
892 		ehdr->cksum = 0;
893 		mhead.m_data = (void *)ehdr;
894 		mhead.m_len = sizeof(*ehdr);
895 		mhead.m_next = 0;
896 		iso_gen_csum(&mhead, offsetof(struct eonhdr, cksum),
897 		    mhead.m_len);
898 	}
899 #else
900 	/* since the data is always constant we'll just plug the value in */
901 	ehdr->cksum = htons(0xfc02);
902 #endif
903 	return m;
904 }
905 
906 /*
907  * remove EON header and check checksum
908  */
909 static struct mbuf *
910 gif_eon_decap(struct ifnet *ifp, struct mbuf *m)
911 {
912 	struct eonhdr *ehdr;
913 
914 	if (m->m_len < sizeof(*ehdr) &&
915 	    (m = m_pullup(m, sizeof(*ehdr))) == NULL) {
916 		ifp->if_ierrors++;
917 		return NULL;
918 	}
919 	if (iso_check_csum(m, sizeof(struct eonhdr))) {
920 		m_freem(m);
921 		return NULL;
922 	}
923 	m_adj(m, sizeof(*ehdr));
924 	return m;
925 }
926 #endif /*ISO*/
927