if_gif.c revision 129880 
1/*	$FreeBSD: head/sys/net/if_gif.c 129880 2004-05-30 20:27:19Z phk $	*/
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/module.h>
44#include <sys/socket.h>
45#include <sys/sockio.h>
46#include <sys/errno.h>
47#include <sys/time.h>
48#include <sys/sysctl.h>
49#include <sys/syslog.h>
50#include <sys/protosw.h>
51#include <sys/conf.h>
52#include <machine/cpu.h>
53
54#include <net/if.h>
55#include <net/if_types.h>
56#include <net/netisr.h>
57#include <net/route.h>
58#include <net/bpf.h>
59
60#include <netinet/in.h>
61#include <netinet/in_systm.h>
62#include <netinet/ip.h>
63#ifdef	INET
64#include <netinet/in_var.h>
65#include <netinet/in_gif.h>
66#include <netinet/ip_var.h>
67#endif	/* INET */
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#include <netinet/ip_encap.h>
81#include <net/if_gif.h>
82
83#include <net/net_osdep.h>
84
85#define GIFNAME		"gif"
86
87/*
88 * gif_mtx protects the global gif_softc_list.
89 * XXX: Per-softc locking is still required.
90 */
91static struct mtx gif_mtx;
92static MALLOC_DEFINE(M_GIF, "gif", "Generic Tunnel Interface");
93static LIST_HEAD(, gif_softc) gif_softc_list;
94
95void	(*ng_gif_input_p)(struct ifnet *ifp, struct mbuf **mp, int af);
96void	(*ng_gif_input_orphan_p)(struct ifnet *ifp, struct mbuf *m, int af);
97void	(*ng_gif_attach_p)(struct ifnet *ifp);
98void	(*ng_gif_detach_p)(struct ifnet *ifp);
99
100static int	gif_clone_create(struct if_clone *, int);
101static void	gif_clone_destroy(struct ifnet *);
102
103struct if_clone gif_cloner = IF_CLONE_INITIALIZER("gif",
104    gif_clone_create, gif_clone_destroy, 0, IF_MAXUNIT);
105
106static int gifmodevent(module_t, int, void *);
107
108SYSCTL_DECL(_net_link);
109SYSCTL_NODE(_net_link, IFT_GIF, gif, CTLFLAG_RW, 0,
110    "Generic Tunnel Interface");
111#ifndef MAX_GIF_NEST
112/*
113 * This macro controls the default upper limitation on nesting of gif tunnels.
114 * Since, setting a large value to this macro with a careless configuration
115 * may introduce system crash, we don't allow any nestings by default.
116 * If you need to configure nested gif tunnels, you can define this macro
117 * in your kernel configuration file.  However, if you do so, please be
118 * careful to configure the tunnels so that it won't make a loop.
119 */
120#define MAX_GIF_NEST 1
121#endif
122static int max_gif_nesting = MAX_GIF_NEST;
123SYSCTL_INT(_net_link_gif, OID_AUTO, max_nesting, CTLFLAG_RW,
124    &max_gif_nesting, 0, "Max nested tunnels");
125
126/*
127 * By default, we disallow creation of multiple tunnels between the same
128 * pair of addresses.  Some applications require this functionality so
129 * we allow control over this check here.
130 */
131#ifdef XBONEHACK
132static int parallel_tunnels = 1;
133#else
134static int parallel_tunnels = 0;
135#endif
136SYSCTL_INT(_net_link_gif, OID_AUTO, parallel_tunnels, CTLFLAG_RW,
137    &parallel_tunnels, 0, "Allow parallel tunnels?");
138
139static int
140gif_clone_create(ifc, unit)
141	struct if_clone *ifc;
142	int unit;
143{
144	struct gif_softc *sc;
145
146	sc = malloc (sizeof(struct gif_softc), M_GIF, M_WAITOK);
147	bzero(sc, sizeof(struct gif_softc));
148
149	sc->gif_if.if_softc = sc;
150	if_initname(&sc->gif_if, ifc->ifc_name, unit);
151
152	gifattach0(sc);
153
154	mtx_lock(&gif_mtx);
155	LIST_INSERT_HEAD(&gif_softc_list, sc, gif_list);
156	mtx_unlock(&gif_mtx);
157	return (0);
158}
159
160void
161gifattach0(sc)
162	struct gif_softc *sc;
163{
164
165	sc->encap_cookie4 = sc->encap_cookie6 = NULL;
166
167	sc->gif_if.if_addrlen = 0;
168	sc->gif_if.if_mtu    = GIF_MTU;
169	sc->gif_if.if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
170#if 0
171	/* turn off ingress filter */
172	sc->gif_if.if_flags  |= IFF_LINK2;
173#endif
174	sc->gif_if.if_ioctl  = gif_ioctl;
175	sc->gif_if.if_output = gif_output;
176	sc->gif_if.if_type   = IFT_GIF;
177	sc->gif_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
178	if_attach(&sc->gif_if);
179	bpfattach(&sc->gif_if, DLT_NULL, sizeof(u_int));
180	if (ng_gif_attach_p != NULL)
181		(*ng_gif_attach_p)(&sc->gif_if);
182}
183
184static void
185gif_destroy(struct gif_softc *sc)
186{
187	struct ifnet *ifp = &sc->gif_if;
188	int err;
189
190	gif_delete_tunnel(ifp);
191#ifdef INET6
192	if (sc->encap_cookie6 != NULL) {
193		err = encap_detach(sc->encap_cookie6);
194		KASSERT(err == 0, ("Unexpected error detaching encap_cookie6"));
195	}
196#endif
197#ifdef INET
198	if (sc->encap_cookie4 != NULL) {
199		err = encap_detach(sc->encap_cookie4);
200		KASSERT(err == 0, ("Unexpected error detaching encap_cookie4"));
201	}
202#endif
203
204	if (ng_gif_detach_p != NULL)
205		(*ng_gif_detach_p)(ifp);
206	bpfdetach(ifp);
207	if_detach(ifp);
208
209	free(sc, M_GIF);
210}
211
212static void
213gif_clone_destroy(ifp)
214	struct ifnet *ifp;
215{
216	struct gif_softc *sc = ifp->if_softc;
217
218	mtx_lock(&gif_mtx);
219	LIST_REMOVE(sc, gif_list);
220	mtx_unlock(&gif_mtx);
221	gif_destroy(sc);
222}
223
224static int
225gifmodevent(mod, type, data)
226	module_t mod;
227	int type;
228	void *data;
229{
230	struct gif_softc *sc;
231
232	switch (type) {
233	case MOD_LOAD:
234		mtx_init(&gif_mtx, "gif_mtx", NULL, MTX_DEF);
235		LIST_INIT(&gif_softc_list);
236		if_clone_attach(&gif_cloner);
237
238#ifdef INET6
239		ip6_gif_hlim = GIF_HLIM;
240#endif
241
242		break;
243	case MOD_UNLOAD:
244		if_clone_detach(&gif_cloner);
245
246		mtx_lock(&gif_mtx);
247		while ((sc = LIST_FIRST(&gif_softc_list)) != NULL) {
248			LIST_REMOVE(sc, gif_list);
249			mtx_unlock(&gif_mtx);
250			gif_destroy(sc);
251			mtx_lock(&gif_mtx);
252		}
253		mtx_unlock(&gif_mtx);
254		mtx_destroy(&gif_mtx);
255#ifdef INET6
256		ip6_gif_hlim = 0;
257#endif
258		break;
259	}
260	return 0;
261}
262
263static moduledata_t gif_mod = {
264	"if_gif",
265	gifmodevent,
266	0
267};
268
269DECLARE_MODULE(if_gif, gif_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
270MODULE_VERSION(if_gif, 1);
271
272int
273gif_encapcheck(m, off, proto, arg)
274	const struct mbuf *m;
275	int off;
276	int proto;
277	void *arg;
278{
279	struct ip ip;
280	struct gif_softc *sc;
281
282	sc = (struct gif_softc *)arg;
283	if (sc == NULL)
284		return 0;
285
286	if ((sc->gif_if.if_flags & IFF_UP) == 0)
287		return 0;
288
289	/* no physical address */
290	if (!sc->gif_psrc || !sc->gif_pdst)
291		return 0;
292
293	switch (proto) {
294#ifdef INET
295	case IPPROTO_IPV4:
296		break;
297#endif
298#ifdef INET6
299	case IPPROTO_IPV6:
300		break;
301#endif
302	default:
303		return 0;
304	}
305
306	/* Bail on short packets */
307	if (m->m_pkthdr.len < sizeof(ip))
308		return 0;
309
310	m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
311
312	switch (ip.ip_v) {
313#ifdef INET
314	case 4:
315		if (sc->gif_psrc->sa_family != AF_INET ||
316		    sc->gif_pdst->sa_family != AF_INET)
317			return 0;
318		return gif_encapcheck4(m, off, proto, arg);
319#endif
320#ifdef INET6
321	case 6:
322		if (m->m_pkthdr.len < sizeof(struct ip6_hdr))
323			return 0;
324		if (sc->gif_psrc->sa_family != AF_INET6 ||
325		    sc->gif_pdst->sa_family != AF_INET6)
326			return 0;
327		return gif_encapcheck6(m, off, proto, arg);
328#endif
329	default:
330		return 0;
331	}
332}
333
334int
335gif_output(ifp, m, dst, rt)
336	struct ifnet *ifp;
337	struct mbuf *m;
338	struct sockaddr *dst;
339	struct rtentry *rt;	/* added in net2 */
340{
341	struct gif_softc *sc = (struct gif_softc*)ifp;
342	struct m_tag *mtag;
343	int error = 0;
344	int gif_called;
345
346#ifdef MAC
347	error = mac_check_ifnet_transmit(ifp, m);
348	if (error) {
349		m_freem(m);
350		goto end;
351	}
352#endif
353
354	/*
355	 * gif may cause infinite recursion calls when misconfigured.
356	 * We'll prevent this by detecting loops.
357	 *
358	 * High nesting level may cause stack exhaustion.
359	 * We'll prevent this by introducing upper limit.
360	 */
361	gif_called = 1;
362	mtag = m_tag_locate(m, MTAG_GIF, MTAG_GIF_CALLED, NULL);
363	while (mtag != NULL) {
364		if (*(struct ifnet **)(mtag + 1) == ifp) {
365			log(LOG_NOTICE,
366			    "gif_output: loop detected on %s\n",
367			    (*(struct ifnet **)(mtag + 1))->if_xname);
368			m_freem(m);
369			error = EIO;	/* is there better errno? */
370			goto end;
371		}
372		mtag = m_tag_locate(m, MTAG_GIF, MTAG_GIF_CALLED, mtag);
373		gif_called++;
374	}
375	if (gif_called > max_gif_nesting) {
376		log(LOG_NOTICE,
377		    "gif_output: recursively called too many times(%d)\n",
378		    gif_called);
379		m_freem(m);
380		error = EIO;	/* is there better errno? */
381		goto end;
382	}
383	mtag = m_tag_alloc(MTAG_GIF, MTAG_GIF_CALLED, sizeof(struct ifnet *),
384	    M_NOWAIT);
385	if (mtag == NULL) {
386		m_freem(m);
387		error = ENOMEM;
388		goto end;
389	}
390	*(struct ifnet **)(mtag + 1) = ifp;
391	m_tag_prepend(m, mtag);
392
393	m->m_flags &= ~(M_BCAST|M_MCAST);
394	if (!(ifp->if_flags & IFF_UP) ||
395	    sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
396		m_freem(m);
397		error = ENETDOWN;
398		goto end;
399	}
400
401	if (ifp->if_bpf) {
402		u_int32_t af = dst->sa_family;
403		bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
404	}
405	ifp->if_opackets++;
406	ifp->if_obytes += m->m_pkthdr.len;
407
408	/* inner AF-specific encapsulation */
409
410	/* XXX should we check if our outer source is legal? */
411
412	/* dispatch to output logic based on outer AF */
413	switch (sc->gif_psrc->sa_family) {
414#ifdef INET
415	case AF_INET:
416		error = in_gif_output(ifp, dst->sa_family, m);
417		break;
418#endif
419#ifdef INET6
420	case AF_INET6:
421		error = in6_gif_output(ifp, dst->sa_family, m);
422		break;
423#endif
424	default:
425		m_freem(m);
426		error = ENETDOWN;
427		goto end;
428	}
429
430  end:
431	if (error)
432		ifp->if_oerrors++;
433	return error;
434}
435
436void
437gif_input(m, af, ifp)
438	struct mbuf *m;
439	int af;
440	struct ifnet *ifp;
441{
442	int isr;
443
444	if (ifp == NULL) {
445		/* just in case */
446		m_freem(m);
447		return;
448	}
449
450	m->m_pkthdr.rcvif = ifp;
451
452#ifdef MAC
453	mac_create_mbuf_from_ifnet(ifp, m);
454#endif
455
456	if (ifp->if_bpf) {
457		u_int32_t af1 = af;
458		bpf_mtap2(ifp->if_bpf, &af1, sizeof(af1), m);
459	}
460
461	if (ng_gif_input_p != NULL) {
462		(*ng_gif_input_p)(ifp, &m, af);
463		if (m == NULL)
464			return;
465	}
466
467	/*
468	 * Put the packet to the network layer input queue according to the
469	 * specified address family.
470	 * Note: older versions of gif_input directly called network layer
471	 * input functions, e.g. ip6_input, here.  We changed the policy to
472	 * prevent too many recursive calls of such input functions, which
473	 * might cause kernel panic.  But the change may introduce another
474	 * problem; if the input queue is full, packets are discarded.
475	 * The kernel stack overflow really happened, and we believed
476	 * queue-full rarely occurs, so we changed the policy.
477	 */
478	switch (af) {
479#ifdef INET
480	case AF_INET:
481		isr = NETISR_IP;
482		break;
483#endif
484#ifdef INET6
485	case AF_INET6:
486		isr = NETISR_IPV6;
487		break;
488#endif
489	default:
490		if (ng_gif_input_orphan_p != NULL)
491			(*ng_gif_input_orphan_p)(ifp, m, af);
492		else
493			m_freem(m);
494		return;
495	}
496
497	ifp->if_ipackets++;
498	ifp->if_ibytes += m->m_pkthdr.len;
499	netisr_dispatch(isr, m);
500}
501
502/* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
503int
504gif_ioctl(ifp, cmd, data)
505	struct ifnet *ifp;
506	u_long cmd;
507	caddr_t data;
508{
509	struct gif_softc *sc  = (struct gif_softc*)ifp;
510	struct ifreq     *ifr = (struct ifreq*)data;
511	int error = 0, size;
512	struct sockaddr *dst, *src;
513#ifdef	SIOCSIFMTU /* xxx */
514	u_long mtu;
515#endif
516
517	switch (cmd) {
518	case SIOCSIFADDR:
519		ifp->if_flags |= IFF_UP;
520		break;
521
522	case SIOCSIFDSTADDR:
523		break;
524
525	case SIOCADDMULTI:
526	case SIOCDELMULTI:
527		break;
528
529#ifdef	SIOCSIFMTU /* xxx */
530	case SIOCGIFMTU:
531		break;
532
533	case SIOCSIFMTU:
534		mtu = ifr->ifr_mtu;
535		if (mtu < GIF_MTU_MIN || mtu > GIF_MTU_MAX)
536			return (EINVAL);
537		ifp->if_mtu = mtu;
538		break;
539#endif /* SIOCSIFMTU */
540
541#ifdef INET
542	case SIOCSIFPHYADDR:
543#endif
544#ifdef INET6
545	case SIOCSIFPHYADDR_IN6:
546#endif /* INET6 */
547	case SIOCSLIFPHYADDR:
548		switch (cmd) {
549#ifdef INET
550		case SIOCSIFPHYADDR:
551			src = (struct sockaddr *)
552				&(((struct in_aliasreq *)data)->ifra_addr);
553			dst = (struct sockaddr *)
554				&(((struct in_aliasreq *)data)->ifra_dstaddr);
555			break;
556#endif
557#ifdef INET6
558		case SIOCSIFPHYADDR_IN6:
559			src = (struct sockaddr *)
560				&(((struct in6_aliasreq *)data)->ifra_addr);
561			dst = (struct sockaddr *)
562				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
563			break;
564#endif
565		case SIOCSLIFPHYADDR:
566			src = (struct sockaddr *)
567				&(((struct if_laddrreq *)data)->addr);
568			dst = (struct sockaddr *)
569				&(((struct if_laddrreq *)data)->dstaddr);
570			break;
571		default:
572			return EINVAL;
573		}
574
575		/* sa_family must be equal */
576		if (src->sa_family != dst->sa_family)
577			return EINVAL;
578
579		/* validate sa_len */
580		switch (src->sa_family) {
581#ifdef INET
582		case AF_INET:
583			if (src->sa_len != sizeof(struct sockaddr_in))
584				return EINVAL;
585			break;
586#endif
587#ifdef INET6
588		case AF_INET6:
589			if (src->sa_len != sizeof(struct sockaddr_in6))
590				return EINVAL;
591			break;
592#endif
593		default:
594			return EAFNOSUPPORT;
595		}
596		switch (dst->sa_family) {
597#ifdef INET
598		case AF_INET:
599			if (dst->sa_len != sizeof(struct sockaddr_in))
600				return EINVAL;
601			break;
602#endif
603#ifdef INET6
604		case AF_INET6:
605			if (dst->sa_len != sizeof(struct sockaddr_in6))
606				return EINVAL;
607			break;
608#endif
609		default:
610			return EAFNOSUPPORT;
611		}
612
613		/* check sa_family looks sane for the cmd */
614		switch (cmd) {
615		case SIOCSIFPHYADDR:
616			if (src->sa_family == AF_INET)
617				break;
618			return EAFNOSUPPORT;
619#ifdef INET6
620		case SIOCSIFPHYADDR_IN6:
621			if (src->sa_family == AF_INET6)
622				break;
623			return EAFNOSUPPORT;
624#endif /* INET6 */
625		case SIOCSLIFPHYADDR:
626			/* checks done in the above */
627			break;
628		}
629
630		error = gif_set_tunnel(&sc->gif_if, src, dst);
631		break;
632
633#ifdef SIOCDIFPHYADDR
634	case SIOCDIFPHYADDR:
635		gif_delete_tunnel(&sc->gif_if);
636		break;
637#endif
638
639	case SIOCGIFPSRCADDR:
640#ifdef INET6
641	case SIOCGIFPSRCADDR_IN6:
642#endif /* INET6 */
643		if (sc->gif_psrc == NULL) {
644			error = EADDRNOTAVAIL;
645			goto bad;
646		}
647		src = sc->gif_psrc;
648		switch (cmd) {
649#ifdef INET
650		case SIOCGIFPSRCADDR:
651			dst = &ifr->ifr_addr;
652			size = sizeof(ifr->ifr_addr);
653			break;
654#endif /* INET */
655#ifdef INET6
656		case SIOCGIFPSRCADDR_IN6:
657			dst = (struct sockaddr *)
658				&(((struct in6_ifreq *)data)->ifr_addr);
659			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
660			break;
661#endif /* INET6 */
662		default:
663			error = EADDRNOTAVAIL;
664			goto bad;
665		}
666		if (src->sa_len > size)
667			return EINVAL;
668		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
669		break;
670
671	case SIOCGIFPDSTADDR:
672#ifdef INET6
673	case SIOCGIFPDSTADDR_IN6:
674#endif /* INET6 */
675		if (sc->gif_pdst == NULL) {
676			error = EADDRNOTAVAIL;
677			goto bad;
678		}
679		src = sc->gif_pdst;
680		switch (cmd) {
681#ifdef INET
682		case SIOCGIFPDSTADDR:
683			dst = &ifr->ifr_addr;
684			size = sizeof(ifr->ifr_addr);
685			break;
686#endif /* INET */
687#ifdef INET6
688		case SIOCGIFPDSTADDR_IN6:
689			dst = (struct sockaddr *)
690				&(((struct in6_ifreq *)data)->ifr_addr);
691			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
692			break;
693#endif /* INET6 */
694		default:
695			error = EADDRNOTAVAIL;
696			goto bad;
697		}
698		if (src->sa_len > size)
699			return EINVAL;
700		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
701		break;
702
703	case SIOCGLIFPHYADDR:
704		if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
705			error = EADDRNOTAVAIL;
706			goto bad;
707		}
708
709		/* copy src */
710		src = sc->gif_psrc;
711		dst = (struct sockaddr *)
712			&(((struct if_laddrreq *)data)->addr);
713		size = sizeof(((struct if_laddrreq *)data)->addr);
714		if (src->sa_len > size)
715			return EINVAL;
716		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
717
718		/* copy dst */
719		src = sc->gif_pdst;
720		dst = (struct sockaddr *)
721			&(((struct if_laddrreq *)data)->dstaddr);
722		size = sizeof(((struct if_laddrreq *)data)->dstaddr);
723		if (src->sa_len > size)
724			return EINVAL;
725		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
726		break;
727
728	case SIOCSIFFLAGS:
729		/* if_ioctl() takes care of it */
730		break;
731
732	default:
733		error = EINVAL;
734		break;
735	}
736 bad:
737	return error;
738}
739
740/*
741 * XXXRW: There's a general event-ordering issue here: the code to check
742 * if a given tunnel is already present happens before we perform a
743 * potentially blocking setup of the tunnel.  This code needs to be
744 * re-ordered so that the check and replacement can be atomic using
745 * a mutex.
746 */
747int
748gif_set_tunnel(ifp, src, dst)
749	struct ifnet *ifp;
750	struct sockaddr *src;
751	struct sockaddr *dst;
752{
753	struct gif_softc *sc = (struct gif_softc *)ifp;
754	struct gif_softc *sc2;
755	struct sockaddr *osrc, *odst, *sa;
756	int s;
757	int error = 0;
758
759	s = splnet();
760
761	mtx_lock(&gif_mtx);
762	LIST_FOREACH(sc2, &gif_softc_list, gif_list) {
763		if (sc2 == sc)
764			continue;
765		if (!sc2->gif_pdst || !sc2->gif_psrc)
766			continue;
767		if (sc2->gif_pdst->sa_family != dst->sa_family ||
768		    sc2->gif_pdst->sa_len != dst->sa_len ||
769		    sc2->gif_psrc->sa_family != src->sa_family ||
770		    sc2->gif_psrc->sa_len != src->sa_len)
771			continue;
772
773		/*
774		 * Disallow parallel tunnels unless instructed
775		 * otherwise.
776		 */
777		if (!parallel_tunnels &&
778		    bcmp(sc2->gif_pdst, dst, dst->sa_len) == 0 &&
779		    bcmp(sc2->gif_psrc, src, src->sa_len) == 0) {
780			error = EADDRNOTAVAIL;
781			mtx_unlock(&gif_mtx);
782			goto bad;
783		}
784
785		/* XXX both end must be valid? (I mean, not 0.0.0.0) */
786	}
787	mtx_unlock(&gif_mtx);
788
789	/* XXX we can detach from both, but be polite just in case */
790	if (sc->gif_psrc)
791		switch (sc->gif_psrc->sa_family) {
792#ifdef INET
793		case AF_INET:
794			(void)in_gif_detach(sc);
795			break;
796#endif
797#ifdef INET6
798		case AF_INET6:
799			(void)in6_gif_detach(sc);
800			break;
801#endif
802		}
803
804	osrc = sc->gif_psrc;
805	sa = (struct sockaddr *)malloc(src->sa_len, M_IFADDR, M_WAITOK);
806	bcopy((caddr_t)src, (caddr_t)sa, src->sa_len);
807	sc->gif_psrc = sa;
808
809	odst = sc->gif_pdst;
810	sa = (struct sockaddr *)malloc(dst->sa_len, M_IFADDR, M_WAITOK);
811	bcopy((caddr_t)dst, (caddr_t)sa, dst->sa_len);
812	sc->gif_pdst = sa;
813
814	switch (sc->gif_psrc->sa_family) {
815#ifdef INET
816	case AF_INET:
817		error = in_gif_attach(sc);
818		break;
819#endif
820#ifdef INET6
821	case AF_INET6:
822		error = in6_gif_attach(sc);
823		break;
824#endif
825	}
826	if (error) {
827		/* rollback */
828		free((caddr_t)sc->gif_psrc, M_IFADDR);
829		free((caddr_t)sc->gif_pdst, M_IFADDR);
830		sc->gif_psrc = osrc;
831		sc->gif_pdst = odst;
832		goto bad;
833	}
834
835	if (osrc)
836		free((caddr_t)osrc, M_IFADDR);
837	if (odst)
838		free((caddr_t)odst, M_IFADDR);
839
840	if (sc->gif_psrc && sc->gif_pdst)
841		ifp->if_flags |= IFF_RUNNING;
842	else
843		ifp->if_flags &= ~IFF_RUNNING;
844	splx(s);
845
846	return 0;
847
848 bad:
849	if (sc->gif_psrc && sc->gif_pdst)
850		ifp->if_flags |= IFF_RUNNING;
851	else
852		ifp->if_flags &= ~IFF_RUNNING;
853	splx(s);
854
855	return error;
856}
857
858void
859gif_delete_tunnel(ifp)
860	struct ifnet *ifp;
861{
862	struct gif_softc *sc = (struct gif_softc *)ifp;
863	int s;
864
865	s = splnet();
866
867	if (sc->gif_psrc) {
868		free((caddr_t)sc->gif_psrc, M_IFADDR);
869		sc->gif_psrc = NULL;
870	}
871	if (sc->gif_pdst) {
872		free((caddr_t)sc->gif_pdst, M_IFADDR);
873		sc->gif_pdst = NULL;
874	}
875	/* it is safe to detach from both */
876#ifdef INET
877	(void)in_gif_detach(sc);
878#endif
879#ifdef INET6
880	(void)in6_gif_detach(sc);
881#endif
882
883	if (sc->gif_psrc && sc->gif_pdst)
884		ifp->if_flags |= IFF_RUNNING;
885	else
886		ifp->if_flags &= ~IFF_RUNNING;
887	splx(s);
888}
889