if_gif.c revision 132199 
1/*	$FreeBSD: head/sys/net/if_gif.c 132199 2004-07-15 08:26:07Z 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_clone.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#include <netinet/in_gif.h>
67#include <netinet/ip_var.h>
68#endif	/* INET */
69
70#ifdef INET6
71#ifndef INET
72#include <netinet/in.h>
73#endif
74#include <netinet6/in6_var.h>
75#include <netinet/ip6.h>
76#include <netinet6/ip6_var.h>
77#include <netinet6/in6_gif.h>
78#include <netinet6/ip6protosw.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#define GIFNAME		"gif"
87
88/*
89 * gif_mtx protects the global gif_softc_list.
90 * XXX: Per-softc locking is still required.
91 */
92static struct mtx gif_mtx;
93static MALLOC_DEFINE(M_GIF, "gif", "Generic Tunnel Interface");
94static LIST_HEAD(, gif_softc) gif_softc_list;
95
96void	(*ng_gif_input_p)(struct ifnet *ifp, struct mbuf **mp, int af);
97void	(*ng_gif_input_orphan_p)(struct ifnet *ifp, struct mbuf *m, int af);
98void	(*ng_gif_attach_p)(struct ifnet *ifp);
99void	(*ng_gif_detach_p)(struct ifnet *ifp);
100
101static int	gif_clone_create(struct if_clone *, int);
102static void	gif_clone_destroy(struct ifnet *);
103
104IFC_SIMPLE_DECLARE(gif, 0);
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 | M_ZERO);
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	default:
259		return EOPNOTSUPP;
260	}
261	return 0;
262}
263
264static moduledata_t gif_mod = {
265	"if_gif",
266	gifmodevent,
267	0
268};
269
270DECLARE_MODULE(if_gif, gif_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
271MODULE_VERSION(if_gif, 1);
272
273int
274gif_encapcheck(m, off, proto, arg)
275	const struct mbuf *m;
276	int off;
277	int proto;
278	void *arg;
279{
280	struct ip ip;
281	struct gif_softc *sc;
282
283	sc = (struct gif_softc *)arg;
284	if (sc == NULL)
285		return 0;
286
287	if ((sc->gif_if.if_flags & IFF_UP) == 0)
288		return 0;
289
290	/* no physical address */
291	if (!sc->gif_psrc || !sc->gif_pdst)
292		return 0;
293
294	switch (proto) {
295#ifdef INET
296	case IPPROTO_IPV4:
297		break;
298#endif
299#ifdef INET6
300	case IPPROTO_IPV6:
301		break;
302#endif
303	default:
304		return 0;
305	}
306
307	/* Bail on short packets */
308	if (m->m_pkthdr.len < sizeof(ip))
309		return 0;
310
311	m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
312
313	switch (ip.ip_v) {
314#ifdef INET
315	case 4:
316		if (sc->gif_psrc->sa_family != AF_INET ||
317		    sc->gif_pdst->sa_family != AF_INET)
318			return 0;
319		return gif_encapcheck4(m, off, proto, arg);
320#endif
321#ifdef INET6
322	case 6:
323		if (m->m_pkthdr.len < sizeof(struct ip6_hdr))
324			return 0;
325		if (sc->gif_psrc->sa_family != AF_INET6 ||
326		    sc->gif_pdst->sa_family != AF_INET6)
327			return 0;
328		return gif_encapcheck6(m, off, proto, arg);
329#endif
330	default:
331		return 0;
332	}
333}
334
335int
336gif_output(ifp, m, dst, rt)
337	struct ifnet *ifp;
338	struct mbuf *m;
339	struct sockaddr *dst;
340	struct rtentry *rt;	/* added in net2 */
341{
342	struct gif_softc *sc = (struct gif_softc*)ifp;
343	struct m_tag *mtag;
344	int error = 0;
345	int gif_called;
346
347#ifdef MAC
348	error = mac_check_ifnet_transmit(ifp, m);
349	if (error) {
350		m_freem(m);
351		goto end;
352	}
353#endif
354
355	/*
356	 * gif may cause infinite recursion calls when misconfigured.
357	 * We'll prevent this by detecting loops.
358	 *
359	 * High nesting level may cause stack exhaustion.
360	 * We'll prevent this by introducing upper limit.
361	 */
362	gif_called = 1;
363	mtag = m_tag_locate(m, MTAG_GIF, MTAG_GIF_CALLED, NULL);
364	while (mtag != NULL) {
365		if (*(struct ifnet **)(mtag + 1) == ifp) {
366			log(LOG_NOTICE,
367			    "gif_output: loop detected on %s\n",
368			    (*(struct ifnet **)(mtag + 1))->if_xname);
369			m_freem(m);
370			error = EIO;	/* is there better errno? */
371			goto end;
372		}
373		mtag = m_tag_locate(m, MTAG_GIF, MTAG_GIF_CALLED, mtag);
374		gif_called++;
375	}
376	if (gif_called > max_gif_nesting) {
377		log(LOG_NOTICE,
378		    "gif_output: recursively called too many times(%d)\n",
379		    gif_called);
380		m_freem(m);
381		error = EIO;	/* is there better errno? */
382		goto end;
383	}
384	mtag = m_tag_alloc(MTAG_GIF, MTAG_GIF_CALLED, sizeof(struct ifnet *),
385	    M_NOWAIT);
386	if (mtag == NULL) {
387		m_freem(m);
388		error = ENOMEM;
389		goto end;
390	}
391	*(struct ifnet **)(mtag + 1) = ifp;
392	m_tag_prepend(m, mtag);
393
394	m->m_flags &= ~(M_BCAST|M_MCAST);
395	if (!(ifp->if_flags & IFF_UP) ||
396	    sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
397		m_freem(m);
398		error = ENETDOWN;
399		goto end;
400	}
401
402	if (ifp->if_bpf) {
403		u_int32_t af = dst->sa_family;
404		bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
405	}
406	ifp->if_opackets++;
407	ifp->if_obytes += m->m_pkthdr.len;
408
409	/* inner AF-specific encapsulation */
410
411	/* XXX should we check if our outer source is legal? */
412
413	/* dispatch to output logic based on outer AF */
414	switch (sc->gif_psrc->sa_family) {
415#ifdef INET
416	case AF_INET:
417		error = in_gif_output(ifp, dst->sa_family, m);
418		break;
419#endif
420#ifdef INET6
421	case AF_INET6:
422		error = in6_gif_output(ifp, dst->sa_family, m);
423		break;
424#endif
425	default:
426		m_freem(m);
427		error = ENETDOWN;
428		goto end;
429	}
430
431  end:
432	if (error)
433		ifp->if_oerrors++;
434	return error;
435}
436
437void
438gif_input(m, af, ifp)
439	struct mbuf *m;
440	int af;
441	struct ifnet *ifp;
442{
443	int isr;
444
445	if (ifp == NULL) {
446		/* just in case */
447		m_freem(m);
448		return;
449	}
450
451	m->m_pkthdr.rcvif = ifp;
452
453#ifdef MAC
454	mac_create_mbuf_from_ifnet(ifp, m);
455#endif
456
457	if (ifp->if_bpf) {
458		u_int32_t af1 = af;
459		bpf_mtap2(ifp->if_bpf, &af1, sizeof(af1), m);
460	}
461
462	if (ng_gif_input_p != NULL) {
463		(*ng_gif_input_p)(ifp, &m, af);
464		if (m == NULL)
465			return;
466	}
467
468	/*
469	 * Put the packet to the network layer input queue according to the
470	 * specified address family.
471	 * Note: older versions of gif_input directly called network layer
472	 * input functions, e.g. ip6_input, here.  We changed the policy to
473	 * prevent too many recursive calls of such input functions, which
474	 * might cause kernel panic.  But the change may introduce another
475	 * problem; if the input queue is full, packets are discarded.
476	 * The kernel stack overflow really happened, and we believed
477	 * queue-full rarely occurs, so we changed the policy.
478	 */
479	switch (af) {
480#ifdef INET
481	case AF_INET:
482		isr = NETISR_IP;
483		break;
484#endif
485#ifdef INET6
486	case AF_INET6:
487		isr = NETISR_IPV6;
488		break;
489#endif
490	default:
491		if (ng_gif_input_orphan_p != NULL)
492			(*ng_gif_input_orphan_p)(ifp, m, af);
493		else
494			m_freem(m);
495		return;
496	}
497
498	ifp->if_ipackets++;
499	ifp->if_ibytes += m->m_pkthdr.len;
500	netisr_dispatch(isr, m);
501}
502
503/* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */
504int
505gif_ioctl(ifp, cmd, data)
506	struct ifnet *ifp;
507	u_long cmd;
508	caddr_t data;
509{
510	struct gif_softc *sc  = (struct gif_softc*)ifp;
511	struct ifreq     *ifr = (struct ifreq*)data;
512	int error = 0, size;
513	struct sockaddr *dst, *src;
514#ifdef	SIOCSIFMTU /* xxx */
515	u_long mtu;
516#endif
517
518	switch (cmd) {
519	case SIOCSIFADDR:
520		ifp->if_flags |= IFF_UP;
521		break;
522
523	case SIOCSIFDSTADDR:
524		break;
525
526	case SIOCADDMULTI:
527	case SIOCDELMULTI:
528		break;
529
530#ifdef	SIOCSIFMTU /* xxx */
531	case SIOCGIFMTU:
532		break;
533
534	case SIOCSIFMTU:
535		mtu = ifr->ifr_mtu;
536		if (mtu < GIF_MTU_MIN || mtu > GIF_MTU_MAX)
537			return (EINVAL);
538		ifp->if_mtu = mtu;
539		break;
540#endif /* SIOCSIFMTU */
541
542#ifdef INET
543	case SIOCSIFPHYADDR:
544#endif
545#ifdef INET6
546	case SIOCSIFPHYADDR_IN6:
547#endif /* INET6 */
548	case SIOCSLIFPHYADDR:
549		switch (cmd) {
550#ifdef INET
551		case SIOCSIFPHYADDR:
552			src = (struct sockaddr *)
553				&(((struct in_aliasreq *)data)->ifra_addr);
554			dst = (struct sockaddr *)
555				&(((struct in_aliasreq *)data)->ifra_dstaddr);
556			break;
557#endif
558#ifdef INET6
559		case SIOCSIFPHYADDR_IN6:
560			src = (struct sockaddr *)
561				&(((struct in6_aliasreq *)data)->ifra_addr);
562			dst = (struct sockaddr *)
563				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
564			break;
565#endif
566		case SIOCSLIFPHYADDR:
567			src = (struct sockaddr *)
568				&(((struct if_laddrreq *)data)->addr);
569			dst = (struct sockaddr *)
570				&(((struct if_laddrreq *)data)->dstaddr);
571			break;
572		default:
573			return EINVAL;
574		}
575
576		/* sa_family must be equal */
577		if (src->sa_family != dst->sa_family)
578			return EINVAL;
579
580		/* validate sa_len */
581		switch (src->sa_family) {
582#ifdef INET
583		case AF_INET:
584			if (src->sa_len != sizeof(struct sockaddr_in))
585				return EINVAL;
586			break;
587#endif
588#ifdef INET6
589		case AF_INET6:
590			if (src->sa_len != sizeof(struct sockaddr_in6))
591				return EINVAL;
592			break;
593#endif
594		default:
595			return EAFNOSUPPORT;
596		}
597		switch (dst->sa_family) {
598#ifdef INET
599		case AF_INET:
600			if (dst->sa_len != sizeof(struct sockaddr_in))
601				return EINVAL;
602			break;
603#endif
604#ifdef INET6
605		case AF_INET6:
606			if (dst->sa_len != sizeof(struct sockaddr_in6))
607				return EINVAL;
608			break;
609#endif
610		default:
611			return EAFNOSUPPORT;
612		}
613
614		/* check sa_family looks sane for the cmd */
615		switch (cmd) {
616		case SIOCSIFPHYADDR:
617			if (src->sa_family == AF_INET)
618				break;
619			return EAFNOSUPPORT;
620#ifdef INET6
621		case SIOCSIFPHYADDR_IN6:
622			if (src->sa_family == AF_INET6)
623				break;
624			return EAFNOSUPPORT;
625#endif /* INET6 */
626		case SIOCSLIFPHYADDR:
627			/* checks done in the above */
628			break;
629		}
630
631		error = gif_set_tunnel(&sc->gif_if, src, dst);
632		break;
633
634#ifdef SIOCDIFPHYADDR
635	case SIOCDIFPHYADDR:
636		gif_delete_tunnel(&sc->gif_if);
637		break;
638#endif
639
640	case SIOCGIFPSRCADDR:
641#ifdef INET6
642	case SIOCGIFPSRCADDR_IN6:
643#endif /* INET6 */
644		if (sc->gif_psrc == NULL) {
645			error = EADDRNOTAVAIL;
646			goto bad;
647		}
648		src = sc->gif_psrc;
649		switch (cmd) {
650#ifdef INET
651		case SIOCGIFPSRCADDR:
652			dst = &ifr->ifr_addr;
653			size = sizeof(ifr->ifr_addr);
654			break;
655#endif /* INET */
656#ifdef INET6
657		case SIOCGIFPSRCADDR_IN6:
658			dst = (struct sockaddr *)
659				&(((struct in6_ifreq *)data)->ifr_addr);
660			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
661			break;
662#endif /* INET6 */
663		default:
664			error = EADDRNOTAVAIL;
665			goto bad;
666		}
667		if (src->sa_len > size)
668			return EINVAL;
669		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
670		break;
671
672	case SIOCGIFPDSTADDR:
673#ifdef INET6
674	case SIOCGIFPDSTADDR_IN6:
675#endif /* INET6 */
676		if (sc->gif_pdst == NULL) {
677			error = EADDRNOTAVAIL;
678			goto bad;
679		}
680		src = sc->gif_pdst;
681		switch (cmd) {
682#ifdef INET
683		case SIOCGIFPDSTADDR:
684			dst = &ifr->ifr_addr;
685			size = sizeof(ifr->ifr_addr);
686			break;
687#endif /* INET */
688#ifdef INET6
689		case SIOCGIFPDSTADDR_IN6:
690			dst = (struct sockaddr *)
691				&(((struct in6_ifreq *)data)->ifr_addr);
692			size = sizeof(((struct in6_ifreq *)data)->ifr_addr);
693			break;
694#endif /* INET6 */
695		default:
696			error = EADDRNOTAVAIL;
697			goto bad;
698		}
699		if (src->sa_len > size)
700			return EINVAL;
701		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
702		break;
703
704	case SIOCGLIFPHYADDR:
705		if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
706			error = EADDRNOTAVAIL;
707			goto bad;
708		}
709
710		/* copy src */
711		src = sc->gif_psrc;
712		dst = (struct sockaddr *)
713			&(((struct if_laddrreq *)data)->addr);
714		size = sizeof(((struct if_laddrreq *)data)->addr);
715		if (src->sa_len > size)
716			return EINVAL;
717		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
718
719		/* copy dst */
720		src = sc->gif_pdst;
721		dst = (struct sockaddr *)
722			&(((struct if_laddrreq *)data)->dstaddr);
723		size = sizeof(((struct if_laddrreq *)data)->dstaddr);
724		if (src->sa_len > size)
725			return EINVAL;
726		bcopy((caddr_t)src, (caddr_t)dst, src->sa_len);
727		break;
728
729	case SIOCSIFFLAGS:
730		/* if_ioctl() takes care of it */
731		break;
732
733	default:
734		error = EINVAL;
735		break;
736	}
737 bad:
738	return error;
739}
740
741/*
742 * XXXRW: There's a general event-ordering issue here: the code to check
743 * if a given tunnel is already present happens before we perform a
744 * potentially blocking setup of the tunnel.  This code needs to be
745 * re-ordered so that the check and replacement can be atomic using
746 * a mutex.
747 */
748int
749gif_set_tunnel(ifp, src, dst)
750	struct ifnet *ifp;
751	struct sockaddr *src;
752	struct sockaddr *dst;
753{
754	struct gif_softc *sc = (struct gif_softc *)ifp;
755	struct gif_softc *sc2;
756	struct sockaddr *osrc, *odst, *sa;
757	int s;
758	int error = 0;
759
760	s = splnet();
761
762	mtx_lock(&gif_mtx);
763	LIST_FOREACH(sc2, &gif_softc_list, gif_list) {
764		if (sc2 == sc)
765			continue;
766		if (!sc2->gif_pdst || !sc2->gif_psrc)
767			continue;
768		if (sc2->gif_pdst->sa_family != dst->sa_family ||
769		    sc2->gif_pdst->sa_len != dst->sa_len ||
770		    sc2->gif_psrc->sa_family != src->sa_family ||
771		    sc2->gif_psrc->sa_len != src->sa_len)
772			continue;
773
774		/*
775		 * Disallow parallel tunnels unless instructed
776		 * otherwise.
777		 */
778		if (!parallel_tunnels &&
779		    bcmp(sc2->gif_pdst, dst, dst->sa_len) == 0 &&
780		    bcmp(sc2->gif_psrc, src, src->sa_len) == 0) {
781			error = EADDRNOTAVAIL;
782			mtx_unlock(&gif_mtx);
783			goto bad;
784		}
785
786		/* XXX both end must be valid? (I mean, not 0.0.0.0) */
787	}
788	mtx_unlock(&gif_mtx);
789
790	/* XXX we can detach from both, but be polite just in case */
791	if (sc->gif_psrc)
792		switch (sc->gif_psrc->sa_family) {
793#ifdef INET
794		case AF_INET:
795			(void)in_gif_detach(sc);
796			break;
797#endif
798#ifdef INET6
799		case AF_INET6:
800			(void)in6_gif_detach(sc);
801			break;
802#endif
803		}
804
805	osrc = sc->gif_psrc;
806	sa = (struct sockaddr *)malloc(src->sa_len, M_IFADDR, M_WAITOK);
807	bcopy((caddr_t)src, (caddr_t)sa, src->sa_len);
808	sc->gif_psrc = sa;
809
810	odst = sc->gif_pdst;
811	sa = (struct sockaddr *)malloc(dst->sa_len, M_IFADDR, M_WAITOK);
812	bcopy((caddr_t)dst, (caddr_t)sa, dst->sa_len);
813	sc->gif_pdst = sa;
814
815	switch (sc->gif_psrc->sa_family) {
816#ifdef INET
817	case AF_INET:
818		error = in_gif_attach(sc);
819		break;
820#endif
821#ifdef INET6
822	case AF_INET6:
823		error = in6_gif_attach(sc);
824		break;
825#endif
826	}
827	if (error) {
828		/* rollback */
829		free((caddr_t)sc->gif_psrc, M_IFADDR);
830		free((caddr_t)sc->gif_pdst, M_IFADDR);
831		sc->gif_psrc = osrc;
832		sc->gif_pdst = odst;
833		goto bad;
834	}
835
836	if (osrc)
837		free((caddr_t)osrc, M_IFADDR);
838	if (odst)
839		free((caddr_t)odst, M_IFADDR);
840
841	if (sc->gif_psrc && sc->gif_pdst)
842		ifp->if_flags |= IFF_RUNNING;
843	else
844		ifp->if_flags &= ~IFF_RUNNING;
845	splx(s);
846
847	return 0;
848
849 bad:
850	if (sc->gif_psrc && sc->gif_pdst)
851		ifp->if_flags |= IFF_RUNNING;
852	else
853		ifp->if_flags &= ~IFF_RUNNING;
854	splx(s);
855
856	return error;
857}
858
859void
860gif_delete_tunnel(ifp)
861	struct ifnet *ifp;
862{
863	struct gif_softc *sc = (struct gif_softc *)ifp;
864	int s;
865
866	s = splnet();
867
868	if (sc->gif_psrc) {
869		free((caddr_t)sc->gif_psrc, M_IFADDR);
870		sc->gif_psrc = NULL;
871	}
872	if (sc->gif_pdst) {
873		free((caddr_t)sc->gif_pdst, M_IFADDR);
874		sc->gif_pdst = NULL;
875	}
876	/* it is safe to detach from both */
877#ifdef INET
878	(void)in_gif_detach(sc);
879#endif
880#ifdef INET6
881	(void)in6_gif_detach(sc);
882#endif
883
884	if (sc->gif_psrc && sc->gif_pdst)
885		ifp->if_flags |= IFF_RUNNING;
886	else
887		ifp->if_flags &= ~IFF_RUNNING;
888	splx(s);
889}
890