xref: /netbsd-src/sys/net/if_gif.c (revision a24efa7dea9f1f56c3bdb15a927d3516792ace1c)
1 /*	$NetBSD: if_gif.c,v 1.109 2016/05/31 03:52:40 knakahara 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 1.109 2016/05/31 03:52:40 knakahara Exp $");
35 
36 #ifdef _KERNEL_OPT
37 #include "opt_inet.h"
38 #endif
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/kernel.h>
43 #include <sys/mbuf.h>
44 #include <sys/socket.h>
45 #include <sys/sockio.h>
46 #include <sys/errno.h>
47 #include <sys/ioctl.h>
48 #include <sys/time.h>
49 #include <sys/socketvar.h>
50 #include <sys/syslog.h>
51 #include <sys/proc.h>
52 #include <sys/cpu.h>
53 #include <sys/intr.h>
54 #include <sys/kmem.h>
55 #include <sys/sysctl.h>
56 
57 #include <net/if.h>
58 #include <net/if_types.h>
59 #include <net/netisr.h>
60 #include <net/route.h>
61 #include <net/bpf.h>
62 
63 #include <netinet/in.h>
64 #include <netinet/in_systm.h>
65 #include <netinet/ip.h>
66 #ifdef	INET
67 #include <netinet/in_var.h>
68 #endif	/* INET */
69 #include <netinet/in_gif.h>
70 
71 #ifdef INET6
72 #ifndef INET
73 #include <netinet/in.h>
74 #endif
75 #include <netinet6/in6_var.h>
76 #include <netinet/ip6.h>
77 #include <netinet6/ip6_var.h>
78 #include <netinet6/in6_gif.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 #include "ioconf.h"
87 
88 static void	gifintr(void *);
89 
90 /*
91  * gif global variable definitions
92  */
93 static LIST_HEAD(, gif_softc) gif_softc_list;
94 
95 static void	gifattach0(struct gif_softc *);
96 static int	gif_output(struct ifnet *, struct mbuf *,
97 			   const struct sockaddr *, const struct rtentry *);
98 static int	gif_ioctl(struct ifnet *, u_long, void *);
99 static int	gif_set_tunnel(struct ifnet *, struct sockaddr *,
100 			       struct sockaddr *);
101 static void	gif_delete_tunnel(struct ifnet *);
102 
103 static void	gif_sysctl_setup(struct sysctllog **);
104 
105 static int	gif_clone_create(struct if_clone *, int);
106 static int	gif_clone_destroy(struct ifnet *);
107 static int	gif_check_nesting(struct ifnet *, struct mbuf *);
108 
109 static int	gif_encap_attach(struct gif_softc *);
110 static int	gif_encap_detach(struct gif_softc *);
111 
112 static struct if_clone gif_cloner =
113     IF_CLONE_INITIALIZER("gif", gif_clone_create, gif_clone_destroy);
114 
115 #ifndef MAX_GIF_NEST
116 /*
117  * This macro controls the upper limitation on nesting of gif tunnels.
118  * Since, setting a large value to this macro with a careless configuration
119  * may introduce system crash, we don't allow any nestings by default.
120  * If you need to configure nested gif tunnels, you can define this macro
121  * in your kernel configuration file.  However, if you do so, please be
122  * careful to configure the tunnels so that it won't make a loop.
123  */
124 #define MAX_GIF_NEST 1
125 #endif
126 static int max_gif_nesting = MAX_GIF_NEST;
127 
128 static void
129 gif_sysctl_setup(struct sysctllog **clog)
130 {
131 
132 #ifdef INET
133 	sysctl_createv(clog, 0, NULL, NULL,
134 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
135 		       CTLTYPE_INT, "gifttl",
136 		       SYSCTL_DESCR("Default TTL for a gif tunnel datagram"),
137 		       NULL, 0, &ip_gif_ttl, 0,
138 		       CTL_NET, PF_INET, IPPROTO_IP,
139 		       IPCTL_GIF_TTL, CTL_EOL);
140 #endif
141 #ifdef INET6
142 	sysctl_createv(clog, 0, NULL, NULL,
143 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
144 		       CTLTYPE_INT, "gifhlim",
145 		       SYSCTL_DESCR("Default hop limit for a gif tunnel datagram"),
146 		       NULL, 0, &ip6_gif_hlim, 0,
147 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
148 		       IPV6CTL_GIF_HLIM, CTL_EOL);
149 #endif
150 }
151 
152 /* ARGSUSED */
153 void
154 gifattach(int count)
155 {
156 
157 	LIST_INIT(&gif_softc_list);
158 	if_clone_attach(&gif_cloner);
159 
160 	gif_sysctl_setup(NULL);
161 }
162 
163 static int
164 gif_clone_create(struct if_clone *ifc, int unit)
165 {
166 	struct gif_softc *sc;
167 
168 	sc = kmem_zalloc(sizeof(struct gif_softc), KM_SLEEP);
169 	if (sc == NULL)
170 		return ENOMEM;
171 
172 	if_initname(&sc->gif_if, ifc->ifc_name, unit);
173 
174 	gifattach0(sc);
175 
176 	LIST_INSERT_HEAD(&gif_softc_list, sc, gif_list);
177 	return (0);
178 }
179 
180 static void
181 gifattach0(struct gif_softc *sc)
182 {
183 
184 	sc->encap_cookie4 = sc->encap_cookie6 = NULL;
185 
186 	sc->gif_if.if_addrlen = 0;
187 	sc->gif_if.if_mtu    = GIF_MTU;
188 	sc->gif_if.if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
189 	sc->gif_if.if_ioctl  = gif_ioctl;
190 	sc->gif_if.if_output = gif_output;
191 	sc->gif_if.if_type   = IFT_GIF;
192 	sc->gif_if.if_dlt    = DLT_NULL;
193 	sc->gif_if.if_softc  = sc;
194 	IFQ_SET_READY(&sc->gif_if.if_snd);
195 	if_attach(&sc->gif_if);
196 	if_alloc_sadl(&sc->gif_if);
197 	bpf_attach(&sc->gif_if, DLT_NULL, sizeof(u_int));
198 }
199 
200 static int
201 gif_clone_destroy(struct ifnet *ifp)
202 {
203 	struct gif_softc *sc = (void *) ifp;
204 
205 	LIST_REMOVE(sc, gif_list);
206 
207 	gif_delete_tunnel(&sc->gif_if);
208 	bpf_detach(ifp);
209 	if_detach(ifp);
210 	rtcache_free(&sc->gif_ro);
211 
212 	kmem_free(sc, sizeof(struct gif_softc));
213 
214 	return (0);
215 }
216 
217 #ifdef GIF_ENCAPCHECK
218 int
219 gif_encapcheck(struct mbuf *m, int off, int proto, void *arg)
220 {
221 	struct ip ip;
222 	struct gif_softc *sc;
223 
224 	sc = arg;
225 	if (sc == NULL)
226 		return 0;
227 
228 	if ((sc->gif_if.if_flags & IFF_UP) == 0)
229 		return 0;
230 
231 	/* no physical address */
232 	if (!sc->gif_psrc || !sc->gif_pdst)
233 		return 0;
234 
235 	switch (proto) {
236 #ifdef INET
237 	case IPPROTO_IPV4:
238 		break;
239 #endif
240 #ifdef INET6
241 	case IPPROTO_IPV6:
242 		break;
243 #endif
244 	default:
245 		return 0;
246 	}
247 
248 	/* Bail on short packets */
249 	KASSERT(m->m_flags & M_PKTHDR);
250 	if (m->m_pkthdr.len < sizeof(ip))
251 		return 0;
252 
253 	m_copydata(m, 0, sizeof(ip), &ip);
254 
255 	switch (ip.ip_v) {
256 #ifdef INET
257 	case 4:
258 		if (sc->gif_psrc->sa_family != AF_INET ||
259 		    sc->gif_pdst->sa_family != AF_INET)
260 			return 0;
261 		return gif_encapcheck4(m, off, proto, arg);
262 #endif
263 #ifdef INET6
264 	case 6:
265 		if (m->m_pkthdr.len < sizeof(struct ip6_hdr))
266 			return 0;
267 		if (sc->gif_psrc->sa_family != AF_INET6 ||
268 		    sc->gif_pdst->sa_family != AF_INET6)
269 			return 0;
270 		return gif_encapcheck6(m, off, proto, arg);
271 #endif
272 	default:
273 		return 0;
274 	}
275 }
276 #endif
277 
278 /*
279  * gif may cause infinite recursion calls when misconfigured.
280  * We'll prevent this by introducing upper limit.
281  */
282 static int
283 gif_check_nesting(struct ifnet *ifp, struct mbuf *m)
284 {
285 	struct m_tag *mtag;
286 	int *count;
287 
288 	mtag = m_tag_find(m, PACKET_TAG_TUNNEL_INFO, NULL);
289 	if (mtag != NULL) {
290 		count = (int *)(mtag + 1);
291 		if (++(*count) > max_gif_nesting) {
292 			log(LOG_NOTICE,
293 			    "%s: recursively called too many times(%d)\n",
294 			    if_name(ifp),
295 			    *count);
296 			return EIO;
297 		}
298 	} else {
299 		mtag = m_tag_get(PACKET_TAG_TUNNEL_INFO, sizeof(*count),
300 		    M_NOWAIT);
301 		if (mtag != NULL) {
302 			m_tag_prepend(m, mtag);
303 			count = (int *)(mtag + 1);
304 			*count = 0;
305 		} else {
306 			log(LOG_DEBUG,
307 			    "%s: m_tag_get() failed, recursion calls are not prevented.\n",
308 			    if_name(ifp));
309 		}
310 	}
311 
312 	return 0;
313 }
314 
315 static int
316 gif_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
317     const struct rtentry *rt)
318 {
319 	struct gif_softc *sc = ifp->if_softc;
320 	int error = 0;
321 	int s;
322 
323 	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family);
324 
325 	if ((error = gif_check_nesting(ifp, m)) != 0) {
326 		m_free(m);
327 		goto end;
328 	}
329 
330 	m->m_flags &= ~(M_BCAST|M_MCAST);
331 	if (!(ifp->if_flags & IFF_UP) ||
332 	    sc->gif_psrc == NULL || sc->gif_pdst == NULL ||
333 	    sc->gif_si == NULL) {
334 		m_freem(m);
335 		error = ENETDOWN;
336 		goto end;
337 	}
338 
339 	/* XXX should we check if our outer source is legal? */
340 
341 	/* use DLT_NULL encapsulation here to pass inner af type */
342 	M_PREPEND(m, sizeof(int), M_DONTWAIT);
343 	if (!m) {
344 		error = ENOBUFS;
345 		goto end;
346 	}
347 	*mtod(m, int *) = dst->sa_family;
348 
349 	/* Clear checksum-offload flags. */
350 	m->m_pkthdr.csum_flags = 0;
351 	m->m_pkthdr.csum_data = 0;
352 
353 	s = splnet();
354 	IFQ_ENQUEUE(&ifp->if_snd, m, error);
355 	if (error) {
356 		splx(s);
357 		goto end;
358 	}
359 
360 	/* softint_schedule() must be called with kpreempt_disabled() */
361 	softint_schedule(sc->gif_si);
362 	splx(s);
363 
364 	error = 0;
365 
366   end:
367 	if (error)
368 		ifp->if_oerrors++;
369 	return error;
370 }
371 
372 static void
373 gifintr(void *arg)
374 {
375 	struct gif_softc *sc;
376 	struct ifnet *ifp;
377 	struct mbuf *m;
378 	int family;
379 	int len;
380 	int s;
381 	int error;
382 
383 	sc = arg;
384 	ifp = &sc->gif_if;
385 
386 	/*
387 	 * other CPUs does {set,delete}_tunnel after curcpu have done
388 	 * softint_schedule().
389 	 */
390 	if (sc->gif_pdst == NULL || sc->gif_psrc == NULL) {
391 		IFQ_PURGE(&ifp->if_snd);
392 		return;
393 	}
394 
395 	/* output processing */
396 	while (1) {
397 		s = splnet();
398 		IFQ_DEQUEUE(&sc->gif_if.if_snd, m);
399 		splx(s);
400 		if (m == NULL)
401 			break;
402 
403 		/* grab and chop off inner af type */
404 		if (sizeof(int) > m->m_len) {
405 			m = m_pullup(m, sizeof(int));
406 			if (!m) {
407 				ifp->if_oerrors++;
408 				continue;
409 			}
410 		}
411 		family = *mtod(m, int *);
412 		bpf_mtap(ifp, m);
413 		m_adj(m, sizeof(int));
414 
415 		len = m->m_pkthdr.len;
416 
417 		/* dispatch to output logic based on outer AF */
418 		switch (sc->gif_psrc->sa_family) {
419 #ifdef INET
420 		case AF_INET:
421 			mutex_enter(softnet_lock);
422 			error = in_gif_output(ifp, family, m);
423 			mutex_exit(softnet_lock);
424 			break;
425 #endif
426 #ifdef INET6
427 		case AF_INET6:
428 			mutex_enter(softnet_lock);
429 			error = in6_gif_output(ifp, family, m);
430 			mutex_exit(softnet_lock);
431 			break;
432 #endif
433 		default:
434 			m_freem(m);
435 			error = ENETDOWN;
436 			break;
437 		}
438 
439 		if (error)
440 			ifp->if_oerrors++;
441 		else {
442 			ifp->if_opackets++;
443 			ifp->if_obytes += len;
444 		}
445 	}
446 }
447 
448 void
449 gif_input(struct mbuf *m, int af, struct ifnet *ifp)
450 {
451 	pktqueue_t *pktq;
452 	size_t pktlen;
453 	int s;
454 
455 	if (ifp == NULL) {
456 		/* just in case */
457 		m_freem(m);
458 		return;
459 	}
460 
461 	m->m_pkthdr.rcvif = ifp;
462 	pktlen = m->m_pkthdr.len;
463 
464 	bpf_mtap_af(ifp, af, m);
465 
466 	/*
467 	 * Put the packet to the network layer input queue according to the
468 	 * specified address family.  Note: we avoid direct call to the
469 	 * input function of the network layer in order to avoid recursion.
470 	 * This may be revisited in the future.
471 	 */
472 	switch (af) {
473 #ifdef INET
474 	case AF_INET:
475 		pktq = ip_pktq;
476 		break;
477 #endif
478 #ifdef INET6
479 	case AF_INET6:
480 		pktq = ip6_pktq;
481 		break;
482 #endif
483 	default:
484 		m_freem(m);
485 		return;
486 	}
487 
488 	s = splnet();
489 	if (__predict_true(pktq_enqueue(pktq, m, 0))) {
490 		ifp->if_ibytes += pktlen;
491 		ifp->if_ipackets++;
492 	} else {
493 		m_freem(m);
494 	}
495 	splx(s);
496 }
497 
498 /* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
499 static int
500 gif_ioctl(struct ifnet *ifp, u_long cmd, void *data)
501 {
502 	struct gif_softc *sc  = ifp->if_softc;
503 	struct ifreq     *ifr = (struct ifreq*)data;
504 	struct ifaddr    *ifa = (struct ifaddr*)data;
505 	int error = 0, size;
506 	struct sockaddr *dst, *src;
507 
508 	switch (cmd) {
509 	case SIOCINITIFADDR:
510 		ifp->if_flags |= IFF_UP;
511 		ifa->ifa_rtrequest = p2p_rtrequest;
512 		break;
513 
514 	case SIOCADDMULTI:
515 	case SIOCDELMULTI:
516 		switch (ifr->ifr_addr.sa_family) {
517 #ifdef INET
518 		case AF_INET:	/* IP supports Multicast */
519 			break;
520 #endif /* INET */
521 #ifdef INET6
522 		case AF_INET6:	/* IP6 supports Multicast */
523 			break;
524 #endif /* INET6 */
525 		default:  /* Other protocols doesn't support Multicast */
526 			error = EAFNOSUPPORT;
527 			break;
528 		}
529 		break;
530 
531 	case SIOCSIFMTU:
532 		if (ifr->ifr_mtu < GIF_MTU_MIN || ifr->ifr_mtu > GIF_MTU_MAX)
533 			return EINVAL;
534 		else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
535 			error = 0;
536 		break;
537 
538 #ifdef INET
539 	case SIOCSIFPHYADDR:
540 #endif
541 #ifdef INET6
542 	case SIOCSIFPHYADDR_IN6:
543 #endif /* INET6 */
544 	case SIOCSLIFPHYADDR:
545 		switch (cmd) {
546 #ifdef INET
547 		case SIOCSIFPHYADDR:
548 			src = (struct sockaddr *)
549 				&(((struct in_aliasreq *)data)->ifra_addr);
550 			dst = (struct sockaddr *)
551 				&(((struct in_aliasreq *)data)->ifra_dstaddr);
552 			break;
553 #endif
554 #ifdef INET6
555 		case SIOCSIFPHYADDR_IN6:
556 			src = (struct sockaddr *)
557 				&(((struct in6_aliasreq *)data)->ifra_addr);
558 			dst = (struct sockaddr *)
559 				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
560 			break;
561 #endif
562 		case SIOCSLIFPHYADDR:
563 			src = (struct sockaddr *)
564 				&(((struct if_laddrreq *)data)->addr);
565 			dst = (struct sockaddr *)
566 				&(((struct if_laddrreq *)data)->dstaddr);
567 			break;
568 		default:
569 			return EINVAL;
570 		}
571 
572 		/* sa_family must be equal */
573 		if (src->sa_family != dst->sa_family)
574 			return EINVAL;
575 
576 		/* validate sa_len */
577 		switch (src->sa_family) {
578 #ifdef INET
579 		case AF_INET:
580 			if (src->sa_len != sizeof(struct sockaddr_in))
581 				return EINVAL;
582 			break;
583 #endif
584 #ifdef INET6
585 		case AF_INET6:
586 			if (src->sa_len != sizeof(struct sockaddr_in6))
587 				return EINVAL;
588 			break;
589 #endif
590 		default:
591 			return EAFNOSUPPORT;
592 		}
593 		switch (dst->sa_family) {
594 #ifdef INET
595 		case AF_INET:
596 			if (dst->sa_len != sizeof(struct sockaddr_in))
597 				return EINVAL;
598 			break;
599 #endif
600 #ifdef INET6
601 		case AF_INET6:
602 			if (dst->sa_len != sizeof(struct sockaddr_in6))
603 				return EINVAL;
604 			break;
605 #endif
606 		default:
607 			return EAFNOSUPPORT;
608 		}
609 
610 		/* check sa_family looks sane for the cmd */
611 		switch (cmd) {
612 		case SIOCSIFPHYADDR:
613 			if (src->sa_family == AF_INET)
614 				break;
615 			return EAFNOSUPPORT;
616 #ifdef INET6
617 		case SIOCSIFPHYADDR_IN6:
618 			if (src->sa_family == AF_INET6)
619 				break;
620 			return EAFNOSUPPORT;
621 #endif /* INET6 */
622 		case SIOCSLIFPHYADDR:
623 			/* checks done in the above */
624 			break;
625 		}
626 
627 		error = gif_set_tunnel(&sc->gif_if, src, dst);
628 		break;
629 
630 #ifdef SIOCDIFPHYADDR
631 	case SIOCDIFPHYADDR:
632 		gif_delete_tunnel(&sc->gif_if);
633 		break;
634 #endif
635 
636 	case SIOCGIFPSRCADDR:
637 #ifdef INET6
638 	case SIOCGIFPSRCADDR_IN6:
639 #endif /* INET6 */
640 		if (sc->gif_psrc == NULL) {
641 			error = EADDRNOTAVAIL;
642 			goto bad;
643 		}
644 		src = sc->gif_psrc;
645 		switch (cmd) {
646 #ifdef INET
647 		case SIOCGIFPSRCADDR:
648 			dst = &ifr->ifr_addr;
649 			size = sizeof(ifr->ifr_addr);
650 			break;
651 #endif /* INET */
652 #ifdef INET6
653 		case SIOCGIFPSRCADDR_IN6:
654 			dst = (struct sockaddr *)
655 				&(((struct in6_ifreq *)data)->ifr_addr);
656 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
657 			break;
658 #endif /* INET6 */
659 		default:
660 			error = EADDRNOTAVAIL;
661 			goto bad;
662 		}
663 		if (src->sa_len > size)
664 			return EINVAL;
665 		memcpy(dst, src, src->sa_len);
666 		break;
667 
668 	case SIOCGIFPDSTADDR:
669 #ifdef INET6
670 	case SIOCGIFPDSTADDR_IN6:
671 #endif /* INET6 */
672 		if (sc->gif_pdst == NULL) {
673 			error = EADDRNOTAVAIL;
674 			goto bad;
675 		}
676 		src = sc->gif_pdst;
677 		switch (cmd) {
678 #ifdef INET
679 		case SIOCGIFPDSTADDR:
680 			dst = &ifr->ifr_addr;
681 			size = sizeof(ifr->ifr_addr);
682 			break;
683 #endif /* INET */
684 #ifdef INET6
685 		case SIOCGIFPDSTADDR_IN6:
686 			dst = (struct sockaddr *)
687 				&(((struct in6_ifreq *)data)->ifr_addr);
688 			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
689 			break;
690 #endif /* INET6 */
691 		default:
692 			error = EADDRNOTAVAIL;
693 			goto bad;
694 		}
695 		if (src->sa_len > size)
696 			return EINVAL;
697 		memcpy(dst, src, src->sa_len);
698 		break;
699 
700 	case SIOCGLIFPHYADDR:
701 		if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
702 			error = EADDRNOTAVAIL;
703 			goto bad;
704 		}
705 
706 		/* copy src */
707 		src = sc->gif_psrc;
708 		dst = (struct sockaddr *)
709 			&(((struct if_laddrreq *)data)->addr);
710 		size = sizeof(((struct if_laddrreq *)data)->addr);
711 		if (src->sa_len > size)
712 			return EINVAL;
713 		memcpy(dst, src, src->sa_len);
714 
715 		/* copy dst */
716 		src = sc->gif_pdst;
717 		dst = (struct sockaddr *)
718 			&(((struct if_laddrreq *)data)->dstaddr);
719 		size = sizeof(((struct if_laddrreq *)data)->dstaddr);
720 		if (src->sa_len > size)
721 			return EINVAL;
722 		memcpy(dst, src, src->sa_len);
723 		break;
724 
725 	default:
726 		return ifioctl_common(ifp, cmd, data);
727 	}
728  bad:
729 	return error;
730 }
731 
732 static int
733 gif_encap_attach(struct gif_softc *sc)
734 {
735 	int error;
736 
737 	if (sc == NULL || sc->gif_psrc == NULL)
738 		return EINVAL;
739 
740 	switch (sc->gif_psrc->sa_family) {
741 #ifdef INET
742 	case AF_INET:
743 		error = in_gif_attach(sc);
744 		break;
745 #endif
746 #ifdef INET6
747 	case AF_INET6:
748 		error = in6_gif_attach(sc);
749 		break;
750 #endif
751 	default:
752 		error = EINVAL;
753 		break;
754 	}
755 
756 	return error;
757 }
758 
759 static int
760 gif_encap_detach(struct gif_softc *sc)
761 {
762 	int error;
763 
764 	if (sc == NULL || sc->gif_psrc == NULL)
765 		return EINVAL;
766 
767 	switch (sc->gif_psrc->sa_family) {
768 #ifdef INET
769 	case AF_INET:
770 		error = in_gif_detach(sc);
771 		break;
772 #endif
773 #ifdef INET6
774 	case AF_INET6:
775 		error = in6_gif_detach(sc);
776 		break;
777 #endif
778 	default:
779 		error = EINVAL;
780 		break;
781 	}
782 
783 	return error;
784 }
785 
786 static int
787 gif_set_tunnel(struct ifnet *ifp, struct sockaddr *src, struct sockaddr *dst)
788 {
789 	struct gif_softc *sc = ifp->if_softc;
790 	struct gif_softc *sc2;
791 	struct sockaddr *osrc, *odst;
792 	struct sockaddr *nsrc, *ndst;
793 	void *osi;
794 	int s;
795 	int error;
796 
797 	s = splsoftnet();
798 
799 	LIST_FOREACH(sc2, &gif_softc_list, gif_list) {
800 		if (sc2 == sc)
801 			continue;
802 		if (!sc2->gif_pdst || !sc2->gif_psrc)
803 			continue;
804 		/* can't configure same pair of address onto two gifs */
805 		if (sockaddr_cmp(sc2->gif_pdst, dst) == 0 &&
806 		    sockaddr_cmp(sc2->gif_psrc, src) == 0) {
807 			/* continue to use the old configureation. */
808 			splx(s);
809 			return EADDRNOTAVAIL;
810 		}
811 
812 		/* XXX both end must be valid? (I mean, not 0.0.0.0) */
813 	}
814 
815 	if ((nsrc = sockaddr_dup(src, M_WAITOK)) == NULL) {
816 		splx(s);
817 		return ENOMEM;
818 	}
819 	if ((ndst = sockaddr_dup(dst, M_WAITOK)) == NULL) {
820 		sockaddr_free(nsrc);
821 		splx(s);
822 		return ENOMEM;
823 	}
824 
825 	/* Firstly, clear old configurations. */
826 	if (sc->gif_si) {
827 		osrc = sc->gif_psrc;
828 		odst = sc->gif_pdst;
829 		osi = sc->gif_si;
830 		sc->gif_psrc = NULL;
831 		sc->gif_pdst = NULL;
832 		sc->gif_si = NULL;
833 		/*
834 		 * At this point, gif_output() does not softint_schedule()
835 		 * any more. However, there are below 2 fears of other CPUs
836 		 * which would cause panic because of the race between
837 		 * softint_execute() and softint_disestablish().
838 		 *     (a) gif_output() has done softint_schedule(), and softint
839 		 *         (gifintr()) is waiting for execution
840 		 *         => This pattern is avoided by waiting SOFTINT_PENDING
841 		 *            CPUs in softint_disestablish()
842 		 *     (b) gifintr() is already running
843 		 *         => This pattern is avoided by waiting SOFTINT_ACTIVE
844 		 *            CPUs in softint_disestablish()
845 		 */
846 
847 		softint_disestablish(osi);
848 		sc->gif_psrc = osrc;
849 		sc->gif_pdst = odst;
850 		osrc = NULL;
851 		odst = NULL;
852 	}
853 	/* XXX we can detach from both, but be polite just in case */
854 	if (sc->gif_psrc)
855 		(void)gif_encap_detach(sc);
856 
857 	/*
858 	 * Secondly, try to set new configurations.
859 	 * If the setup failed, rollback to old configurations.
860 	 */
861 	do {
862 		osrc = sc->gif_psrc;
863 		odst = sc->gif_pdst;
864 		sc->gif_psrc = nsrc;
865 		sc->gif_pdst = ndst;
866 
867 		error = gif_encap_attach(sc);
868 		if (error) {
869 			/* rollback to the last configuration. */
870 			nsrc = osrc;
871 			ndst = odst;
872 			osrc = sc->gif_psrc;
873 			odst = sc->gif_pdst;
874 
875 			continue;
876 		}
877 
878 		sc->gif_si = softint_establish(SOFTINT_NET, gifintr, sc);
879 		if (sc->gif_si == NULL) {
880 			(void)gif_encap_detach(sc);
881 
882 			/* rollback to the last configuration. */
883 			nsrc = osrc;
884 			ndst = odst;
885 			osrc = sc->gif_psrc;
886 			odst = sc->gif_pdst;
887 
888 			error = ENOMEM;
889 			continue;
890 		}
891 	} while (error != 0 && (nsrc != NULL && ndst != NULL));
892 	/* Thirdly, even rollback failed, clear configurations. */
893 	if (error) {
894 		osrc = sc->gif_psrc;
895 		odst = sc->gif_pdst;
896 		sc->gif_psrc = NULL;
897 		sc->gif_pdst = NULL;
898 	}
899 
900 	if (osrc)
901 		sockaddr_free(osrc);
902 	if (odst)
903 		sockaddr_free(odst);
904 
905 	if (sc->gif_psrc && sc->gif_pdst)
906 		ifp->if_flags |= IFF_RUNNING;
907 	else
908 		ifp->if_flags &= ~IFF_RUNNING;
909 
910 	splx(s);
911 	return error;
912 }
913 
914 static void
915 gif_delete_tunnel(struct ifnet *ifp)
916 {
917 	struct gif_softc *sc = ifp->if_softc;
918 	struct sockaddr *osrc, *odst;
919 	void *osi;
920 	int s;
921 
922 	s = splsoftnet();
923 
924 	if (sc->gif_si) {
925 		osrc = sc->gif_psrc;
926 		odst = sc->gif_pdst;
927 		osi = sc->gif_si;
928 
929 		sc->gif_psrc = NULL;
930 		sc->gif_pdst = NULL;
931 		sc->gif_si = NULL;
932 
933 		softint_disestablish(osi);
934 		sc->gif_psrc = osrc;
935 		sc->gif_pdst = odst;
936 	}
937 	if (sc->gif_psrc) {
938 		sockaddr_free(sc->gif_psrc);
939 		sc->gif_psrc = NULL;
940 	}
941 	if (sc->gif_pdst) {
942 		sockaddr_free(sc->gif_pdst);
943 		sc->gif_pdst = NULL;
944 	}
945 	/* it is safe to detach from both */
946 #ifdef INET
947 	(void)in_gif_detach(sc);
948 #endif
949 #ifdef INET6
950 	(void)in6_gif_detach(sc);
951 #endif
952 
953 	if (sc->gif_psrc && sc->gif_pdst)
954 		ifp->if_flags |= IFF_RUNNING;
955 	else
956 		ifp->if_flags &= ~IFF_RUNNING;
957 	splx(s);
958 }
959