if_gif.c revision 128209 
1/*	$FreeBSD: head/sys/net/if_gif.c 128209 2004-04-14 00:57:49Z brooks $	*/
2/*	$KAME: if_gif.c,v 1.87 2001/10/19 08:50:27 itojun Exp $	*/
3
4/*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include "opt_inet.h"
34#include "opt_inet6.h"
35#include "opt_mac.h"
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/kernel.h>
40#include <sys/mac.h>
41#include <sys/malloc.h>
42#include <sys/mbuf.h>
43#include <sys/socket.h>
44#include <sys/sockio.h>
45#include <sys/errno.h>
46#include <sys/time.h>
47#include <sys/sysctl.h>
48#include <sys/syslog.h>
49#include <sys/protosw.h>
50#include <sys/conf.h>
51#include <machine/cpu.h>
52
53#include <net/if.h>
54#include <net/if_types.h>
55#include <net/netisr.h>
56#include <net/route.h>
57#include <net/bpf.h>
58
59#include <netinet/in.h>
60#include <netinet/in_systm.h>
61#include <netinet/ip.h>
62#ifdef	INET
63#include <netinet/in_var.h>
64#include <netinet/in_gif.h>
65#include <netinet/ip_var.h>
66#endif	/* INET */
67
68#ifdef INET6
69#ifndef INET
70#include <netinet/in.h>
71#endif
72#include <netinet6/in6_var.h>
73#include <netinet/ip6.h>
74#include <netinet6/ip6_var.h>
75#include <netinet6/in6_gif.h>
76#include <netinet6/ip6protosw.h>
77#endif /* INET6 */
78
79#include <netinet/ip_encap.h>
80#include <net/if_gif.h>
81
82#include <net/net_osdep.h>
83
84#define GIFNAME		"gif"
85
86/*
87 * gif_mtx protects the global gif_softc_list.
88 * XXX: Per-softc locking is still required.
89 */
90static struct mtx gif_mtx;
91static MALLOC_DEFINE(M_GIF, "gif", "Generic Tunnel Interface");
92static LIST_HEAD(, gif_softc) gif_softc_list;
93
94void	(*ng_gif_input_p)(struct ifnet *ifp, struct mbuf **mp, int af);
95void	(*ng_gif_input_orphan_p)(struct ifnet *ifp, struct mbuf *m, int af);
96void	(*ng_gif_attach_p)(struct ifnet *ifp);
97void	(*ng_gif_detach_p)(struct ifnet *ifp);
98
99static int	gif_clone_create(struct if_clone *, int);
100static void	gif_clone_destroy(struct ifnet *);
101
102struct if_clone gif_cloner = IF_CLONE_INITIALIZER("gif",
103    gif_clone_create, gif_clone_destroy, 0, IF_MAXUNIT);
104
105static int gifmodevent(module_t, int, void *);
106
107SYSCTL_DECL(_net_link);
108SYSCTL_NODE(_net_link, IFT_GIF, gif, CTLFLAG_RW, 0,
109    "Generic Tunnel Interface");
110#ifndef MAX_GIF_NEST
111/*
112 * This macro controls the default 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
121static int max_gif_nesting = MAX_GIF_NEST;
122SYSCTL_INT(_net_link_gif, OID_AUTO, max_nesting, CTLFLAG_RW,
123    &max_gif_nesting, 0, "Max nested tunnels");
124
125/*
126 * By default, we disallow creation of multiple tunnels between the same
127 * pair of addresses.  Some applications require this functionality so
128 * we allow control over this check here.
129 */
130#ifdef XBONEHACK
131static int parallel_tunnels = 1;
132#else
133static int parallel_tunnels = 0;
134#endif
135SYSCTL_INT(_net_link_gif, OID_AUTO, parallel_tunnels, CTLFLAG_RW,
136    &parallel_tunnels, 0, "Allow parallel tunnels?");
137
138static int
139gif_clone_create(ifc, unit)
140	struct if_clone *ifc;
141	int unit;
142{
143	struct gif_softc *sc;
144
145	sc = malloc (sizeof(struct gif_softc), M_GIF, M_WAITOK);
146	bzero(sc, sizeof(struct gif_softc));
147
148	sc->gif_if.if_softc = sc;
149	if_initname(&sc->gif_if, ifc->ifc_name, unit);
150
151	gifattach0(sc);
152
153	mtx_lock(&gif_mtx);
154	LIST_INSERT_HEAD(&gif_softc_list, sc, gif_list);
155	mtx_unlock(&gif_mtx);
156	return (0);
157}
158
159void
160gifattach0(sc)
161	struct gif_softc *sc;
162{
163
164	sc->encap_cookie4 = sc->encap_cookie6 = NULL;
165
166	sc->gif_if.if_addrlen = 0;
167	sc->gif_if.if_mtu    = GIF_MTU;
168	sc->gif_if.if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
169#if 0
170	/* turn off ingress filter */
171	sc->gif_if.if_flags  |= IFF_LINK2;
172#endif
173	sc->gif_if.if_ioctl  = gif_ioctl;
174	sc->gif_if.if_output = gif_output;
175	sc->gif_if.if_type   = IFT_GIF;
176	sc->gif_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
177	if_attach(&sc->gif_if);
178	bpfattach(&sc->gif_if, DLT_NULL, sizeof(u_int));
179	if (ng_gif_attach_p != NULL)
180		(*ng_gif_attach_p)(&sc->gif_if);
181}
182
183static void
184gif_destroy(struct gif_softc *sc)
185{
186	struct ifnet *ifp = &sc->gif_if;
187	int err;
188
189	gif_delete_tunnel(ifp);
190#ifdef INET6
191	if (sc->encap_cookie6 != NULL) {
192		err = encap_detach(sc->encap_cookie6);
193		KASSERT(err == 0, ("Unexpected error detaching encap_cookie6"));
194	}
195#endif
196#ifdef INET
197	if (sc->encap_cookie4 != NULL) {
198		err = encap_detach(sc->encap_cookie4);
199		KASSERT(err == 0, ("Unexpected error detaching encap_cookie4"));
200	}
201#endif
202
203	if (ng_gif_detach_p != NULL)
204		(*ng_gif_detach_p)(ifp);
205	bpfdetach(ifp);
206	if_detach(ifp);
207
208	free(sc, M_GIF);
209}
210
211static void
212gif_clone_destroy(ifp)
213	struct ifnet *ifp;
214{
215	struct gif_softc *sc = ifp->if_softc;
216
217	mtx_lock(&gif_mtx);
218	LIST_REMOVE(sc, gif_list);
219	mtx_unlock(&gif_mtx);
220	gif_destroy(sc);
221}
222
223static int
224gifmodevent(mod, type, data)
225	module_t mod;
226	int type;
227	void *data;
228{
229	struct gif_softc *sc;
230
231	switch (type) {
232	case MOD_LOAD:
233		mtx_init(&gif_mtx, "gif_mtx", NULL, MTX_DEF);
234		LIST_INIT(&gif_softc_list);
235		if_clone_attach(&gif_cloner);
236
237#ifdef INET6
238		ip6_gif_hlim = GIF_HLIM;
239#endif
240
241		break;
242	case MOD_UNLOAD:
243		if_clone_detach(&gif_cloner);
244
245		mtx_lock(&gif_mtx);
246		while ((sc = LIST_FIRST(&gif_softc_list)) != NULL) {
247			LIST_REMOVE(sc, gif_list);
248			mtx_unlock(&gif_mtx);
249			gif_destroy(sc);
250			mtx_lock(&gif_mtx);
251		}
252		mtx_unlock(&gif_mtx);
253		mtx_destroy(&gif_mtx);
254#ifdef INET6
255		ip6_gif_hlim = 0;
256#endif
257		break;
258	}
259	return 0;
260}
261
262static moduledata_t gif_mod = {
263	"if_gif",
264	gifmodevent,
265	0
266};
267
268DECLARE_MODULE(if_gif, gif_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
269MODULE_VERSION(if_gif, 1);
270
271int
272gif_encapcheck(m, off, proto, arg)
273	const struct mbuf *m;
274	int off;
275	int proto;
276	void *arg;
277{
278	struct ip ip;
279	struct gif_softc *sc;
280
281	sc = (struct gif_softc *)arg;
282	if (sc == NULL)
283		return 0;
284
285	if ((sc->gif_if.if_flags & IFF_UP) == 0)
286		return 0;
287
288	/* no physical address */
289	if (!sc->gif_psrc || !sc->gif_pdst)
290		return 0;
291
292	switch (proto) {
293#ifdef INET
294	case IPPROTO_IPV4:
295		break;
296#endif
297#ifdef INET6
298	case IPPROTO_IPV6:
299		break;
300#endif
301	default:
302		return 0;
303	}
304
305	/* Bail on short packets */
306	if (m->m_pkthdr.len < sizeof(ip))
307		return 0;
308
309	m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
310
311	switch (ip.ip_v) {
312#ifdef INET
313	case 4:
314		if (sc->gif_psrc->sa_family != AF_INET ||
315		    sc->gif_pdst->sa_family != AF_INET)
316			return 0;
317		return gif_encapcheck4(m, off, proto, arg);
318#endif
319#ifdef INET6
320	case 6:
321		if (m->m_pkthdr.len < sizeof(struct ip6_hdr))
322			return 0;
323		if (sc->gif_psrc->sa_family != AF_INET6 ||
324		    sc->gif_pdst->sa_family != AF_INET6)
325			return 0;
326		return gif_encapcheck6(m, off, proto, arg);
327#endif
328	default:
329		return 0;
330	}
331}
332
333int
334gif_output(ifp, m, dst, rt)
335	struct ifnet *ifp;
336	struct mbuf *m;
337	struct sockaddr *dst;
338	struct rtentry *rt;	/* added in net2 */
339{
340	struct gif_softc *sc = (struct gif_softc*)ifp;
341	struct m_tag *mtag;
342	int error = 0;
343	int gif_called;
344
345#ifdef MAC
346	error = mac_check_ifnet_transmit(ifp, m);
347	if (error) {
348		m_freem(m);
349		goto end;
350	}
351#endif
352
353	/*
354	 * gif may cause infinite recursion calls when misconfigured.
355	 * We'll prevent this by detecting loops.
356	 *
357	 * High nesting level may cause stack exhaustion.
358	 * We'll prevent this by introducing upper limit.
359	 */
360	gif_called = 1;
361	mtag = m_tag_locate(m, MTAG_GIF, MTAG_GIF_CALLED, NULL);
362	while (mtag != NULL) {
363		if (*(struct ifnet **)(mtag + 1) == ifp) {
364			log(LOG_NOTICE,
365			    "gif_output: loop detected on %s\n",
366			    (*(struct ifnet **)(mtag + 1))->if_xname);
367			m_freem(m);
368			error = EIO;	/* is there better errno? */
369			goto end;
370		}
371		mtag = m_tag_locate(m, MTAG_GIF, MTAG_GIF_CALLED, mtag);
372		gif_called++;
373	}
374	if (gif_called > max_gif_nesting) {
375		log(LOG_NOTICE,
376		    "gif_output: recursively called too many times(%d)\n",
377		    gif_called);
378		m_freem(m);
379		error = EIO;	/* is there better errno? */
380		goto end;
381	}
382	mtag = m_tag_alloc(MTAG_GIF, MTAG_GIF_CALLED, sizeof(struct ifnet *),
383	    M_NOWAIT);
384	if (mtag == NULL) {
385		m_freem(m);
386		error = ENOMEM;
387		goto end;
388	}
389	*(struct ifnet **)(mtag + 1) = ifp;
390	m_tag_prepend(m, mtag);
391
392	m->m_flags &= ~(M_BCAST|M_MCAST);
393	if (!(ifp->if_flags & IFF_UP) ||
394	    sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
395		m_freem(m);
396		error = ENETDOWN;
397		goto end;
398	}
399
400	if (ifp->if_bpf) {
401		u_int32_t af = dst->sa_family;
402		bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
403	}
404	ifp->if_opackets++;
405	ifp->if_obytes += m->m_pkthdr.len;
406
407	/* inner AF-specific encapsulation */
408
409	/* XXX should we check if our outer source is legal? */
410
411	/* dispatch to output logic based on outer AF */
412	switch (sc->gif_psrc->sa_family) {
413#ifdef INET
414	case AF_INET:
415		error = in_gif_output(ifp, dst->sa_family, m);
416		break;
417#endif
418#ifdef INET6
419	case AF_INET6:
420		error = in6_gif_output(ifp, dst->sa_family, m);
421		break;
422#endif
423	default:
424		m_freem(m);
425		error = ENETDOWN;
426		goto end;
427	}
428
429  end:
430	if (error)
431		ifp->if_oerrors++;
432	return error;
433}
434
435void
436gif_input(m, af, ifp)
437	struct mbuf *m;
438	int af;
439	struct ifnet *ifp;
440{
441	int isr;
442
443	if (ifp == NULL) {
444		/* just in case */
445		m_freem(m);
446		return;
447	}
448
449	m->m_pkthdr.rcvif = ifp;
450
451#ifdef MAC
452	mac_create_mbuf_from_ifnet(ifp, m);
453#endif
454
455	if (ifp->if_bpf) {
456		u_int32_t af1 = af;
457		bpf_mtap2(ifp->if_bpf, &af1, sizeof(af1), m);
458	}
459
460	if (ng_gif_input_p != NULL) {
461		(*ng_gif_input_p)(ifp, &m, af);
462		if (m == NULL)
463			return;
464	}
465
466	/*
467	 * Put the packet to the network layer input queue according to the
468	 * specified address family.
469	 * Note: older versions of gif_input directly called network layer
470	 * input functions, e.g. ip6_input, here.  We changed the policy to
471	 * prevent too many recursive calls of such input functions, which
472	 * might cause kernel panic.  But the change may introduce another
473	 * problem; if the input queue is full, packets are discarded.
474	 * The kernel stack overflow really happened, and we believed
475	 * queue-full rarely occurs, so we changed the policy.
476	 */
477	switch (af) {
478#ifdef INET
479	case AF_INET:
480		isr = NETISR_IP;
481		break;
482#endif
483#ifdef INET6
484	case AF_INET6:
485		isr = NETISR_IPV6;
486		break;
487#endif
488	default:
489		if (ng_gif_input_orphan_p != NULL)
490			(*ng_gif_input_orphan_p)(ifp, m, af);
491		else
492			m_freem(m);
493		return;
494	}
495
496	ifp->if_ipackets++;
497	ifp->if_ibytes += m->m_pkthdr.len;
498	netisr_dispatch(isr, m);
499}
500
501/* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
502int
503gif_ioctl(ifp, cmd, data)
504	struct ifnet *ifp;
505	u_long cmd;
506	caddr_t data;
507{
508	struct gif_softc *sc  = (struct gif_softc*)ifp;
509	struct ifreq     *ifr = (struct ifreq*)data;
510	int error = 0, size;
511	struct sockaddr *dst, *src;
512#ifdef	SIOCSIFMTU /* xxx */
513	u_long mtu;
514#endif
515
516	switch (cmd) {
517	case SIOCSIFADDR:
518		ifp->if_flags |= IFF_UP;
519		break;
520
521	case SIOCSIFDSTADDR:
522		break;
523
524	case SIOCADDMULTI:
525	case SIOCDELMULTI:
526		break;
527
528#ifdef	SIOCSIFMTU /* xxx */
529	case SIOCGIFMTU:
530		break;
531
532	case SIOCSIFMTU:
533		mtu = ifr->ifr_mtu;
534		if (mtu < GIF_MTU_MIN || mtu > GIF_MTU_MAX)
535			return (EINVAL);
536		ifp->if_mtu = mtu;
537		break;
538#endif /* SIOCSIFMTU */
539
540#ifdef INET
541	case SIOCSIFPHYADDR:
542#endif
543#ifdef INET6
544	case SIOCSIFPHYADDR_IN6:
545#endif /* INET6 */
546	case SIOCSLIFPHYADDR:
547		switch (cmd) {
548#ifdef INET
549		case SIOCSIFPHYADDR:
550			src = (struct sockaddr *)
551				&(((struct in_aliasreq *)data)->ifra_addr);
552			dst = (struct sockaddr *)
553				&(((struct in_aliasreq *)data)->ifra_dstaddr);
554			break;
555#endif
556#ifdef INET6
557		case SIOCSIFPHYADDR_IN6:
558			src = (struct sockaddr *)
559				&(((struct in6_aliasreq *)data)->ifra_addr);
560			dst = (struct sockaddr *)
561				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
562			break;
563#endif
564		case SIOCSLIFPHYADDR:
565			src = (struct sockaddr *)
566				&(((struct if_laddrreq *)data)->addr);
567			dst = (struct sockaddr *)
568				&(((struct if_laddrreq *)data)->dstaddr);
569			break;
570		default:
571			return EINVAL;
572		}
573
574		/* sa_family must be equal */
575		if (src->sa_family != dst->sa_family)
576			return EINVAL;
577
578		/* validate sa_len */
579		switch (src->sa_family) {
580#ifdef INET
581		case AF_INET:
582			if (src->sa_len != sizeof(struct sockaddr_in))
583				return EINVAL;
584			break;
585#endif
586#ifdef INET6
587		case AF_INET6:
588			if (src->sa_len != sizeof(struct sockaddr_in6))
589				return EINVAL;
590			break;
591#endif
592		default:
593			return EAFNOSUPPORT;
594		}
595		switch (dst->sa_family) {
596#ifdef INET
597		case AF_INET:
598			if (dst->sa_len != sizeof(struct sockaddr_in))
599				return EINVAL;
600			break;
601#endif
602#ifdef INET6
603		case AF_INET6:
604			if (dst->sa_len != sizeof(struct sockaddr_in6))
605				return EINVAL;
606			break;
607#endif
608		default:
609			return EAFNOSUPPORT;
610		}
611
612		/* check sa_family looks sane for the cmd */
613		switch (cmd) {
614		case SIOCSIFPHYADDR:
615			if (src->sa_family == AF_INET)
616				break;
617			return EAFNOSUPPORT;
618#ifdef INET6
619		case SIOCSIFPHYADDR_IN6:
620			if (src->sa_family == AF_INET6)
621				break;
622			return EAFNOSUPPORT;
623#endif /* INET6 */
624		case SIOCSLIFPHYADDR:
625			/* checks done in the above */
626			break;
627		}
628
629		error = gif_set_tunnel(&sc->gif_if, src, dst);
630		break;
631
632#ifdef SIOCDIFPHYADDR
633	case SIOCDIFPHYADDR:
634		gif_delete_tunnel(&sc->gif_if);
635		break;
636#endif
637
638	case SIOCGIFPSRCADDR:
639#ifdef INET6
640	case SIOCGIFPSRCADDR_IN6:
641#endif /* INET6 */
642		if (sc->gif_psrc == NULL) {
643			error = EADDRNOTAVAIL;
644			goto bad;
645		}
646		src = sc->gif_psrc;
647		switch (cmd) {
648#ifdef INET
649		case SIOCGIFPSRCADDR:
650			dst = &ifr->ifr_addr;
651			size = sizeof(ifr->ifr_addr);
652			break;
653#endif /* INET */
654#ifdef INET6
655		case SIOCGIFPSRCADDR_IN6:
656			dst = (struct sockaddr *)
657				&(((struct in6_ifreq *)data)->ifr_addr);
658			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
659			break;
660#endif /* INET6 */
661		default:
662			error = EADDRNOTAVAIL;
663			goto bad;
664		}
665		if (src->sa_len > size)
666			return EINVAL;
667		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
668		break;
669
670	case SIOCGIFPDSTADDR:
671#ifdef INET6
672	case SIOCGIFPDSTADDR_IN6:
673#endif /* INET6 */
674		if (sc->gif_pdst == NULL) {
675			error = EADDRNOTAVAIL;
676			goto bad;
677		}
678		src = sc->gif_pdst;
679		switch (cmd) {
680#ifdef INET
681		case SIOCGIFPDSTADDR:
682			dst = &ifr->ifr_addr;
683			size = sizeof(ifr->ifr_addr);
684			break;
685#endif /* INET */
686#ifdef INET6
687		case SIOCGIFPDSTADDR_IN6:
688			dst = (struct sockaddr *)
689				&(((struct in6_ifreq *)data)->ifr_addr);
690			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
691			break;
692#endif /* INET6 */
693		default:
694			error = EADDRNOTAVAIL;
695			goto bad;
696		}
697		if (src->sa_len > size)
698			return EINVAL;
699		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
700		break;
701
702	case SIOCGLIFPHYADDR:
703		if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
704			error = EADDRNOTAVAIL;
705			goto bad;
706		}
707
708		/* copy src */
709		src = sc->gif_psrc;
710		dst = (struct sockaddr *)
711			&(((struct if_laddrreq *)data)->addr);
712		size = sizeof(((struct if_laddrreq *)data)->addr);
713		if (src->sa_len > size)
714			return EINVAL;
715		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
716
717		/* copy dst */
718		src = sc->gif_pdst;
719		dst = (struct sockaddr *)
720			&(((struct if_laddrreq *)data)->dstaddr);
721		size = sizeof(((struct if_laddrreq *)data)->dstaddr);
722		if (src->sa_len > size)
723			return EINVAL;
724		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
725		break;
726
727	case SIOCSIFFLAGS:
728		/* if_ioctl() takes care of it */
729		break;
730
731	default:
732		error = EINVAL;
733		break;
734	}
735 bad:
736	return error;
737}
738
739/*
740 * XXXRW: There's a general event-ordering issue here: the code to check
741 * if a given tunnel is already present happens before we perform a
742 * potentially blocking setup of the tunnel.  This code needs to be
743 * re-ordered so that the check and replacement can be atomic using
744 * a mutex.
745 */
746int
747gif_set_tunnel(ifp, src, dst)
748	struct ifnet *ifp;
749	struct sockaddr *src;
750	struct sockaddr *dst;
751{
752	struct gif_softc *sc = (struct gif_softc *)ifp;
753	struct gif_softc *sc2;
754	struct sockaddr *osrc, *odst, *sa;
755	int s;
756	int error = 0;
757
758	s = splnet();
759
760	mtx_lock(&gif_mtx);
761	LIST_FOREACH(sc2, &gif_softc_list, gif_list) {
762		if (sc2 == sc)
763			continue;
764		if (!sc2->gif_pdst || !sc2->gif_psrc)
765			continue;
766		if (sc2->gif_pdst->sa_family != dst->sa_family ||
767		    sc2->gif_pdst->sa_len != dst->sa_len ||
768		    sc2->gif_psrc->sa_family != src->sa_family ||
769		    sc2->gif_psrc->sa_len != src->sa_len)
770			continue;
771
772		/*
773		 * Disallow parallel tunnels unless instructed
774		 * otherwise.
775		 */
776		if (!parallel_tunnels &&
777		    bcmp(sc2->gif_pdst, dst, dst->sa_len) == 0 &&
778		    bcmp(sc2->gif_psrc, src, src->sa_len) == 0) {
779			error = EADDRNOTAVAIL;
780			mtx_unlock(&gif_mtx);
781			goto bad;
782		}
783
784		/* XXX both end must be valid? (I mean, not 0.0.0.0) */
785	}
786	mtx_unlock(&gif_mtx);
787
788	/* XXX we can detach from both, but be polite just in case */
789	if (sc->gif_psrc)
790		switch (sc->gif_psrc->sa_family) {
791#ifdef INET
792		case AF_INET:
793			(void)in_gif_detach(sc);
794			break;
795#endif
796#ifdef INET6
797		case AF_INET6:
798			(void)in6_gif_detach(sc);
799			break;
800#endif
801		}
802
803	osrc = sc->gif_psrc;
804	sa = (struct sockaddr *)malloc(src->sa_len, M_IFADDR, M_WAITOK);
805	bcopy((caddr_t)src, (caddr_t)sa, src->sa_len);
806	sc->gif_psrc = sa;
807
808	odst = sc->gif_pdst;
809	sa = (struct sockaddr *)malloc(dst->sa_len, M_IFADDR, M_WAITOK);
810	bcopy((caddr_t)dst, (caddr_t)sa, dst->sa_len);
811	sc->gif_pdst = sa;
812
813	switch (sc->gif_psrc->sa_family) {
814#ifdef INET
815	case AF_INET:
816		error = in_gif_attach(sc);
817		break;
818#endif
819#ifdef INET6
820	case AF_INET6:
821		error = in6_gif_attach(sc);
822		break;
823#endif
824	}
825	if (error) {
826		/* rollback */
827		free((caddr_t)sc->gif_psrc, M_IFADDR);
828		free((caddr_t)sc->gif_pdst, M_IFADDR);
829		sc->gif_psrc = osrc;
830		sc->gif_pdst = odst;
831		goto bad;
832	}
833
834	if (osrc)
835		free((caddr_t)osrc, M_IFADDR);
836	if (odst)
837		free((caddr_t)odst, M_IFADDR);
838
839	if (sc->gif_psrc && sc->gif_pdst)
840		ifp->if_flags |= IFF_RUNNING;
841	else
842		ifp->if_flags &= ~IFF_RUNNING;
843	splx(s);
844
845	return 0;
846
847 bad:
848	if (sc->gif_psrc && sc->gif_pdst)
849		ifp->if_flags |= IFF_RUNNING;
850	else
851		ifp->if_flags &= ~IFF_RUNNING;
852	splx(s);
853
854	return error;
855}
856
857void
858gif_delete_tunnel(ifp)
859	struct ifnet *ifp;
860{
861	struct gif_softc *sc = (struct gif_softc *)ifp;
862	int s;
863
864	s = splnet();
865
866	if (sc->gif_psrc) {
867		free((caddr_t)sc->gif_psrc, M_IFADDR);
868		sc->gif_psrc = NULL;
869	}
870	if (sc->gif_pdst) {
871		free((caddr_t)sc->gif_pdst, M_IFADDR);
872		sc->gif_pdst = NULL;
873	}
874	/* it is safe to detach from both */
875#ifdef INET
876	(void)in_gif_detach(sc);
877#endif
878#ifdef INET6
879	(void)in6_gif_detach(sc);
880#endif
881
882	if (sc->gif_psrc && sc->gif_pdst)
883		ifp->if_flags |= IFF_RUNNING;
884	else
885		ifp->if_flags &= ~IFF_RUNNING;
886	splx(s);
887}
888