if_stf.c revision 331722
1/*	$FreeBSD: stable/11/sys/net/if_stf.c 331722 2018-03-29 02:50:57Z eadler $	*/
2/*	$KAME: if_stf.c,v 1.73 2001/12/03 11:08:30 keiichi Exp $	*/
3
4/*-
5 * Copyright (C) 2000 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/*
34 * 6to4 interface, based on RFC3056.
35 *
36 * 6to4 interface is NOT capable of link-layer (I mean, IPv4) multicasting.
37 * There is no address mapping defined from IPv6 multicast address to IPv4
38 * address.  Therefore, we do not have IFF_MULTICAST on the interface.
39 *
40 * Due to the lack of address mapping for link-local addresses, we cannot
41 * throw packets toward link-local addresses (fe80::x).  Also, we cannot throw
42 * packets to link-local multicast addresses (ff02::x).
43 *
44 * Here are interesting symptoms due to the lack of link-local address:
45 *
46 * Unicast routing exchange:
47 * - RIPng: Impossible.  Uses link-local multicast packet toward ff02::9,
48 *   and link-local addresses as nexthop.
49 * - OSPFv6: Impossible.  OSPFv6 assumes that there's link-local address
50 *   assigned to the link, and makes use of them.  Also, HELLO packets use
51 *   link-local multicast addresses (ff02::5 and ff02::6).
52 * - BGP4+: Maybe.  You can only use global address as nexthop, and global
53 *   address as TCP endpoint address.
54 *
55 * Multicast routing protocols:
56 * - PIM: Hello packet cannot be used to discover adjacent PIM routers.
57 *   Adjacent PIM routers must be configured manually (is it really spec-wise
58 *   correct thing to do?).
59 *
60 * ICMPv6:
61 * - Redirects cannot be used due to the lack of link-local address.
62 *
63 * stf interface does not have, and will not need, a link-local address.
64 * It seems to have no real benefit and does not help the above symptoms much.
65 * Even if we assign link-locals to interface, we cannot really
66 * use link-local unicast/multicast on top of 6to4 cloud (since there's no
67 * encapsulation defined for link-local address), and the above analysis does
68 * not change.  RFC3056 does not mandate the assignment of link-local address
69 * either.
70 *
71 * 6to4 interface has security issues.  Refer to
72 * http://playground.iijlab.net/i-d/draft-itojun-ipv6-transition-abuse-00.txt
73 * for details.  The code tries to filter out some of malicious packets.
74 * Note that there is no way to be 100% secure.
75 */
76
77#include <sys/param.h>
78#include <sys/systm.h>
79#include <sys/socket.h>
80#include <sys/sockio.h>
81#include <sys/mbuf.h>
82#include <sys/errno.h>
83#include <sys/kernel.h>
84#include <sys/lock.h>
85#include <sys/module.h>
86#include <sys/protosw.h>
87#include <sys/proc.h>
88#include <sys/queue.h>
89#include <sys/rmlock.h>
90#include <sys/sysctl.h>
91#include <machine/cpu.h>
92
93#include <sys/malloc.h>
94
95#include <net/if.h>
96#include <net/if_var.h>
97#include <net/if_clone.h>
98#include <net/route.h>
99#include <net/netisr.h>
100#include <net/if_types.h>
101#include <net/vnet.h>
102
103#include <netinet/in.h>
104#include <netinet/in_fib.h>
105#include <netinet/in_systm.h>
106#include <netinet/ip.h>
107#include <netinet/ip_var.h>
108#include <netinet/in_var.h>
109
110#include <netinet/ip6.h>
111#include <netinet6/ip6_var.h>
112#include <netinet6/in6_var.h>
113#include <netinet/ip_ecn.h>
114
115#include <netinet/ip_encap.h>
116
117#include <machine/stdarg.h>
118
119#include <net/bpf.h>
120
121#include <security/mac/mac_framework.h>
122
123SYSCTL_DECL(_net_link);
124static SYSCTL_NODE(_net_link, IFT_STF, stf, CTLFLAG_RW, 0, "6to4 Interface");
125
126static int stf_permit_rfc1918 = 0;
127SYSCTL_INT(_net_link_stf, OID_AUTO, permit_rfc1918, CTLFLAG_RWTUN,
128    &stf_permit_rfc1918, 0, "Permit the use of private IPv4 addresses");
129
130#define STFUNIT		0
131
132#define IN6_IS_ADDR_6TO4(x)	(ntohs((x)->s6_addr16[0]) == 0x2002)
133
134/*
135 * XXX: Return a pointer with 16-bit aligned.  Don't cast it to
136 * struct in_addr *; use bcopy() instead.
137 */
138#define GET_V4(x)	(&(x)->s6_addr16[1])
139
140struct stf_softc {
141	struct ifnet	*sc_ifp;
142	struct mtx	sc_ro_mtx;
143	u_int	sc_fibnum;
144	const struct encaptab *encap_cookie;
145};
146#define STF2IFP(sc)	((sc)->sc_ifp)
147
148static const char stfname[] = "stf";
149
150/*
151 * Note that mutable fields in the softc are not currently locked.
152 * We do lock sc_ro in stf_output though.
153 */
154static MALLOC_DEFINE(M_STF, stfname, "6to4 Tunnel Interface");
155static const int ip_stf_ttl = 40;
156
157extern  struct domain inetdomain;
158static int in_stf_input(struct mbuf **, int *, int);
159static struct protosw in_stf_protosw = {
160	.pr_type =		SOCK_RAW,
161	.pr_domain =		&inetdomain,
162	.pr_protocol =		IPPROTO_IPV6,
163	.pr_flags =		PR_ATOMIC|PR_ADDR,
164	.pr_input =		in_stf_input,
165	.pr_output =		rip_output,
166	.pr_ctloutput =		rip_ctloutput,
167	.pr_usrreqs =		&rip_usrreqs
168};
169
170static char *stfnames[] = {"stf0", "stf", "6to4", NULL};
171
172static int stfmodevent(module_t, int, void *);
173static int stf_encapcheck(const struct mbuf *, int, int, void *);
174static int stf_getsrcifa6(struct ifnet *, struct in6_addr *, struct in6_addr *);
175static int stf_output(struct ifnet *, struct mbuf *, const struct sockaddr *,
176	struct route *);
177static int isrfc1918addr(struct in_addr *);
178static int stf_checkaddr4(struct stf_softc *, struct in_addr *,
179	struct ifnet *);
180static int stf_checkaddr6(struct stf_softc *, struct in6_addr *,
181	struct ifnet *);
182static int stf_ioctl(struct ifnet *, u_long, caddr_t);
183
184static int stf_clone_match(struct if_clone *, const char *);
185static int stf_clone_create(struct if_clone *, char *, size_t, caddr_t);
186static int stf_clone_destroy(struct if_clone *, struct ifnet *);
187static struct if_clone *stf_cloner;
188
189static int
190stf_clone_match(struct if_clone *ifc, const char *name)
191{
192	int i;
193
194	for(i = 0; stfnames[i] != NULL; i++) {
195		if (strcmp(stfnames[i], name) == 0)
196			return (1);
197	}
198
199	return (0);
200}
201
202static int
203stf_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
204{
205	int err, unit;
206	struct stf_softc *sc;
207	struct ifnet *ifp;
208
209	/*
210	 * We can only have one unit, but since unit allocation is
211	 * already locked, we use it to keep from allocating extra
212	 * interfaces.
213	 */
214	unit = STFUNIT;
215	err = ifc_alloc_unit(ifc, &unit);
216	if (err != 0)
217		return (err);
218
219	sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO);
220	ifp = STF2IFP(sc) = if_alloc(IFT_STF);
221	if (ifp == NULL) {
222		free(sc, M_STF);
223		ifc_free_unit(ifc, unit);
224		return (ENOSPC);
225	}
226	ifp->if_softc = sc;
227	sc->sc_fibnum = curthread->td_proc->p_fibnum;
228
229	/*
230	 * Set the name manually rather then using if_initname because
231	 * we don't conform to the default naming convention for interfaces.
232	 */
233	strlcpy(ifp->if_xname, name, IFNAMSIZ);
234	ifp->if_dname = stfname;
235	ifp->if_dunit = IF_DUNIT_NONE;
236
237	mtx_init(&(sc)->sc_ro_mtx, "stf ro", NULL, MTX_DEF);
238	sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6,
239	    stf_encapcheck, &in_stf_protosw, sc);
240	if (sc->encap_cookie == NULL) {
241		if_printf(ifp, "attach failed\n");
242		free(sc, M_STF);
243		ifc_free_unit(ifc, unit);
244		return (ENOMEM);
245	}
246
247	ifp->if_mtu    = IPV6_MMTU;
248	ifp->if_ioctl  = stf_ioctl;
249	ifp->if_output = stf_output;
250	ifp->if_snd.ifq_maxlen = ifqmaxlen;
251	if_attach(ifp);
252	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
253	return (0);
254}
255
256static int
257stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
258{
259	struct stf_softc *sc = ifp->if_softc;
260	int err;
261
262	err = encap_detach(sc->encap_cookie);
263	KASSERT(err == 0, ("Unexpected error detaching encap_cookie"));
264	mtx_destroy(&(sc)->sc_ro_mtx);
265	bpfdetach(ifp);
266	if_detach(ifp);
267	if_free(ifp);
268
269	free(sc, M_STF);
270	ifc_free_unit(ifc, STFUNIT);
271
272	return (0);
273}
274
275static int
276stfmodevent(module_t mod, int type, void *data)
277{
278
279	switch (type) {
280	case MOD_LOAD:
281		stf_cloner = if_clone_advanced(stfname, 0, stf_clone_match,
282		    stf_clone_create, stf_clone_destroy);
283		break;
284	case MOD_UNLOAD:
285		if_clone_detach(stf_cloner);
286		break;
287	default:
288		return (EOPNOTSUPP);
289	}
290
291	return (0);
292}
293
294static moduledata_t stf_mod = {
295	"if_stf",
296	stfmodevent,
297	0
298};
299
300DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
301
302static int
303stf_encapcheck(const struct mbuf *m, int off, int proto, void *arg)
304{
305	struct ip ip;
306	struct stf_softc *sc;
307	struct in_addr a, b, mask;
308	struct in6_addr addr6, mask6;
309
310	sc = (struct stf_softc *)arg;
311	if (sc == NULL)
312		return 0;
313
314	if ((STF2IFP(sc)->if_flags & IFF_UP) == 0)
315		return 0;
316
317	/* IFF_LINK0 means "no decapsulation" */
318	if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0)
319		return 0;
320
321	if (proto != IPPROTO_IPV6)
322		return 0;
323
324	/* LINTED const cast */
325	m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip);
326
327	if (ip.ip_v != 4)
328		return 0;
329
330	if (stf_getsrcifa6(STF2IFP(sc), &addr6, &mask6) != 0)
331		return (0);
332
333	/*
334	 * check if IPv4 dst matches the IPv4 address derived from the
335	 * local 6to4 address.
336	 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:...
337	 */
338	if (bcmp(GET_V4(&addr6), &ip.ip_dst, sizeof(ip.ip_dst)) != 0)
339		return 0;
340
341	/*
342	 * check if IPv4 src matches the IPv4 address derived from the
343	 * local 6to4 address masked by prefixmask.
344	 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24
345	 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24
346	 */
347	bzero(&a, sizeof(a));
348	bcopy(GET_V4(&addr6), &a, sizeof(a));
349	bcopy(GET_V4(&mask6), &mask, sizeof(mask));
350	a.s_addr &= mask.s_addr;
351	b = ip.ip_src;
352	b.s_addr &= mask.s_addr;
353	if (a.s_addr != b.s_addr)
354		return 0;
355
356	/* stf interface makes single side match only */
357	return 32;
358}
359
360static int
361stf_getsrcifa6(struct ifnet *ifp, struct in6_addr *addr, struct in6_addr *mask)
362{
363	struct ifaddr *ia;
364	struct in_ifaddr *ia4;
365	struct in6_ifaddr *ia6;
366	struct sockaddr_in6 *sin6;
367	struct in_addr in;
368
369	if_addr_rlock(ifp);
370	TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
371		if (ia->ifa_addr->sa_family != AF_INET6)
372			continue;
373		sin6 = (struct sockaddr_in6 *)ia->ifa_addr;
374		if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr))
375			continue;
376
377		bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in));
378		LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash)
379			if (ia4->ia_addr.sin_addr.s_addr == in.s_addr)
380				break;
381		if (ia4 == NULL)
382			continue;
383
384		ia6 = (struct in6_ifaddr *)ia;
385
386		*addr = sin6->sin6_addr;
387		*mask = ia6->ia_prefixmask.sin6_addr;
388		if_addr_runlock(ifp);
389		return (0);
390	}
391	if_addr_runlock(ifp);
392
393	return (ENOENT);
394}
395
396static int
397stf_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
398    struct route *ro)
399{
400	struct stf_softc *sc;
401	const struct sockaddr_in6 *dst6;
402	struct in_addr in4;
403	const void *ptr;
404	u_int8_t tos;
405	struct ip *ip;
406	struct ip6_hdr *ip6;
407	struct in6_addr addr6, mask6;
408	int error;
409
410#ifdef MAC
411	error = mac_ifnet_check_transmit(ifp, m);
412	if (error) {
413		m_freem(m);
414		return (error);
415	}
416#endif
417
418	sc = ifp->if_softc;
419	dst6 = (const struct sockaddr_in6 *)dst;
420
421	/* just in case */
422	if ((ifp->if_flags & IFF_UP) == 0) {
423		m_freem(m);
424		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
425		return ENETDOWN;
426	}
427
428	/*
429	 * If we don't have an ip4 address that match my inner ip6 address,
430	 * we shouldn't generate output.  Without this check, we'll end up
431	 * using wrong IPv4 source.
432	 */
433	if (stf_getsrcifa6(ifp, &addr6, &mask6) != 0) {
434		m_freem(m);
435		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
436		return ENETDOWN;
437	}
438
439	if (m->m_len < sizeof(*ip6)) {
440		m = m_pullup(m, sizeof(*ip6));
441		if (!m) {
442			if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
443			return ENOBUFS;
444		}
445	}
446	ip6 = mtod(m, struct ip6_hdr *);
447	tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
448
449	/*
450	 * Pickup the right outer dst addr from the list of candidates.
451	 * ip6_dst has priority as it may be able to give us shorter IPv4 hops.
452	 */
453	ptr = NULL;
454	if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst))
455		ptr = GET_V4(&ip6->ip6_dst);
456	else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr))
457		ptr = GET_V4(&dst6->sin6_addr);
458	else {
459		m_freem(m);
460		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
461		return ENETUNREACH;
462	}
463	bcopy(ptr, &in4, sizeof(in4));
464
465	if (bpf_peers_present(ifp->if_bpf)) {
466		/*
467		 * We need to prepend the address family as
468		 * a four byte field.  Cons up a dummy header
469		 * to pacify bpf.  This is safe because bpf
470		 * will only read from the mbuf (i.e., it won't
471		 * try to free it or keep a pointer a to it).
472		 */
473		u_int af = AF_INET6;
474		bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
475	}
476
477	M_PREPEND(m, sizeof(struct ip), M_NOWAIT);
478	if (m == NULL) {
479		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
480		return ENOBUFS;
481	}
482	ip = mtod(m, struct ip *);
483
484	bzero(ip, sizeof(*ip));
485
486	bcopy(GET_V4(&addr6), &ip->ip_src, sizeof(ip->ip_src));
487	bcopy(&in4, &ip->ip_dst, sizeof(ip->ip_dst));
488	ip->ip_p = IPPROTO_IPV6;
489	ip->ip_ttl = ip_stf_ttl;
490	ip->ip_len = htons(m->m_pkthdr.len);
491	if (ifp->if_flags & IFF_LINK1)
492		ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos);
493	else
494		ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos);
495
496	M_SETFIB(m, sc->sc_fibnum);
497	if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
498	error = ip_output(m, NULL, NULL, 0, NULL, NULL);
499
500	return error;
501}
502
503static int
504isrfc1918addr(struct in_addr *in)
505{
506	/*
507	 * returns 1 if private address range:
508	 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16
509	 */
510	if (stf_permit_rfc1918 == 0 && (
511	    (ntohl(in->s_addr) & 0xff000000) >> 24 == 10 ||
512	    (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 ||
513	    (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168))
514		return 1;
515
516	return 0;
517}
518
519static int
520stf_checkaddr4(struct stf_softc *sc, struct in_addr *in, struct ifnet *inifp)
521{
522	struct rm_priotracker in_ifa_tracker;
523	struct in_ifaddr *ia4;
524
525	/*
526	 * reject packets with the following address:
527	 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8
528	 */
529	if (IN_MULTICAST(ntohl(in->s_addr)))
530		return -1;
531	switch ((ntohl(in->s_addr) & 0xff000000) >> 24) {
532	case 0: case 127: case 255:
533		return -1;
534	}
535
536	/*
537	 * reject packets with private address range.
538	 * (requirement from RFC3056 section 2 1st paragraph)
539	 */
540	if (isrfc1918addr(in))
541		return -1;
542
543	/*
544	 * reject packets with broadcast
545	 */
546	IN_IFADDR_RLOCK(&in_ifa_tracker);
547	TAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) {
548		if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
549			continue;
550		if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) {
551			IN_IFADDR_RUNLOCK(&in_ifa_tracker);
552			return -1;
553		}
554	}
555	IN_IFADDR_RUNLOCK(&in_ifa_tracker);
556
557	/*
558	 * perform ingress filter
559	 */
560	if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) {
561		struct nhop4_basic nh4;
562
563		if (fib4_lookup_nh_basic(sc->sc_fibnum, *in, 0, 0, &nh4) != 0)
564			return (-1);
565
566		if (nh4.nh_ifp != inifp)
567			return (-1);
568	}
569
570	return 0;
571}
572
573static int
574stf_checkaddr6(struct stf_softc *sc, struct in6_addr *in6, struct ifnet *inifp)
575{
576	/*
577	 * check 6to4 addresses
578	 */
579	if (IN6_IS_ADDR_6TO4(in6)) {
580		struct in_addr in4;
581		bcopy(GET_V4(in6), &in4, sizeof(in4));
582		return stf_checkaddr4(sc, &in4, inifp);
583	}
584
585	/*
586	 * reject anything that look suspicious.  the test is implemented
587	 * in ip6_input too, but we check here as well to
588	 * (1) reject bad packets earlier, and
589	 * (2) to be safe against future ip6_input change.
590	 */
591	if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6))
592		return -1;
593
594	return 0;
595}
596
597static int
598in_stf_input(struct mbuf **mp, int *offp, int proto)
599{
600	struct stf_softc *sc;
601	struct ip *ip;
602	struct ip6_hdr *ip6;
603	struct mbuf *m;
604	u_int8_t otos, itos;
605	struct ifnet *ifp;
606	int off;
607
608	m = *mp;
609	off = *offp;
610
611	if (proto != IPPROTO_IPV6) {
612		m_freem(m);
613		return (IPPROTO_DONE);
614	}
615
616	ip = mtod(m, struct ip *);
617
618	sc = (struct stf_softc *)encap_getarg(m);
619
620	if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) {
621		m_freem(m);
622		return (IPPROTO_DONE);
623	}
624
625	ifp = STF2IFP(sc);
626
627#ifdef MAC
628	mac_ifnet_create_mbuf(ifp, m);
629#endif
630
631	/*
632	 * perform sanity check against outer src/dst.
633	 * for source, perform ingress filter as well.
634	 */
635	if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 ||
636	    stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) {
637		m_freem(m);
638		return (IPPROTO_DONE);
639	}
640
641	otos = ip->ip_tos;
642	m_adj(m, off);
643
644	if (m->m_len < sizeof(*ip6)) {
645		m = m_pullup(m, sizeof(*ip6));
646		if (!m)
647			return (IPPROTO_DONE);
648	}
649	ip6 = mtod(m, struct ip6_hdr *);
650
651	/*
652	 * perform sanity check against inner src/dst.
653	 * for source, perform ingress filter as well.
654	 */
655	if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 ||
656	    stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) {
657		m_freem(m);
658		return (IPPROTO_DONE);
659	}
660
661	itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
662	if ((ifp->if_flags & IFF_LINK1) != 0)
663		ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
664	else
665		ip_ecn_egress(ECN_NOCARE, &otos, &itos);
666	ip6->ip6_flow &= ~htonl(0xff << 20);
667	ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
668
669	m->m_pkthdr.rcvif = ifp;
670
671	if (bpf_peers_present(ifp->if_bpf)) {
672		/*
673		 * We need to prepend the address family as
674		 * a four byte field.  Cons up a dummy header
675		 * to pacify bpf.  This is safe because bpf
676		 * will only read from the mbuf (i.e., it won't
677		 * try to free it or keep a pointer a to it).
678		 */
679		u_int32_t af = AF_INET6;
680		bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
681	}
682
683	/*
684	 * Put the packet to the network layer input queue according to the
685	 * specified address family.
686	 * See net/if_gif.c for possible issues with packet processing
687	 * reorder due to extra queueing.
688	 */
689	if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
690	if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
691	M_SETFIB(m, ifp->if_fib);
692	netisr_dispatch(NETISR_IPV6, m);
693	return (IPPROTO_DONE);
694}
695
696static int
697stf_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
698{
699	struct ifaddr *ifa;
700	struct ifreq *ifr;
701	struct sockaddr_in6 *sin6;
702	struct in_addr addr;
703	int error, mtu;
704
705	error = 0;
706	switch (cmd) {
707	case SIOCSIFADDR:
708		ifa = (struct ifaddr *)data;
709		if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) {
710			error = EAFNOSUPPORT;
711			break;
712		}
713		sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
714		if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) {
715			error = EINVAL;
716			break;
717		}
718		bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr));
719		if (isrfc1918addr(&addr)) {
720			error = EINVAL;
721			break;
722		}
723
724		ifp->if_flags |= IFF_UP;
725		break;
726
727	case SIOCADDMULTI:
728	case SIOCDELMULTI:
729		ifr = (struct ifreq *)data;
730		if (ifr && ifr->ifr_addr.sa_family == AF_INET6)
731			;
732		else
733			error = EAFNOSUPPORT;
734		break;
735
736	case SIOCGIFMTU:
737		break;
738
739	case SIOCSIFMTU:
740		ifr = (struct ifreq *)data;
741		mtu = ifr->ifr_mtu;
742		/* RFC 4213 3.2 ideal world MTU */
743		if (mtu < IPV6_MINMTU || mtu > IF_MAXMTU - 20)
744			return (EINVAL);
745		ifp->if_mtu = mtu;
746		break;
747
748	default:
749		error = EINVAL;
750		break;
751	}
752
753	return error;
754}
755