1/*	$FreeBSD$	*/
2/*	$KAME: if_stf.c,v 1.73 2001/12/03 11:08:30 keiichi Exp $	*/
3
4/*-
5 * SPDX-License-Identifier: BSD-3-Clause
6 *
7 * Copyright (C) 2000 WIDE Project.
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the project nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35/*
36 * 6to4 interface, based on RFC3056.
37 *
38 * 6to4 interface is NOT capable of link-layer (I mean, IPv4) multicasting.
39 * There is no address mapping defined from IPv6 multicast address to IPv4
40 * address.  Therefore, we do not have IFF_MULTICAST on the interface.
41 *
42 * Due to the lack of address mapping for link-local addresses, we cannot
43 * throw packets toward link-local addresses (fe80::x).  Also, we cannot throw
44 * packets to link-local multicast addresses (ff02::x).
45 *
46 * Here are interesting symptoms due to the lack of link-local address:
47 *
48 * Unicast routing exchange:
49 * - RIPng: Impossible.  Uses link-local multicast packet toward ff02::9,
50 *   and link-local addresses as nexthop.
51 * - OSPFv6: Impossible.  OSPFv6 assumes that there's link-local address
52 *   assigned to the link, and makes use of them.  Also, HELLO packets use
53 *   link-local multicast addresses (ff02::5 and ff02::6).
54 * - BGP4+: Maybe.  You can only use global address as nexthop, and global
55 *   address as TCP endpoint address.
56 *
57 * Multicast routing protocols:
58 * - PIM: Hello packet cannot be used to discover adjacent PIM routers.
59 *   Adjacent PIM routers must be configured manually (is it really spec-wise
60 *   correct thing to do?).
61 *
62 * ICMPv6:
63 * - Redirects cannot be used due to the lack of link-local address.
64 *
65 * stf interface does not have, and will not need, a link-local address.
66 * It seems to have no real benefit and does not help the above symptoms much.
67 * Even if we assign link-locals to interface, we cannot really
68 * use link-local unicast/multicast on top of 6to4 cloud (since there's no
69 * encapsulation defined for link-local address), and the above analysis does
70 * not change.  RFC3056 does not mandate the assignment of link-local address
71 * either.
72 *
73 * 6to4 interface has security issues.  Refer to
74 * http://playground.iijlab.net/i-d/draft-itojun-ipv6-transition-abuse-00.txt
75 * for details.  The code tries to filter out some of malicious packets.
76 * Note that there is no way to be 100% secure.
77 */
78
79#include <sys/param.h>
80#include <sys/systm.h>
81#include <sys/socket.h>
82#include <sys/sockio.h>
83#include <sys/mbuf.h>
84#include <sys/errno.h>
85#include <sys/kernel.h>
86#include <sys/lock.h>
87#include <sys/module.h>
88#include <sys/proc.h>
89#include <sys/queue.h>
90#include <sys/rmlock.h>
91#include <sys/sysctl.h>
92#include <machine/cpu.h>
93
94#include <sys/malloc.h>
95
96#include <net/if.h>
97#include <net/if_var.h>
98#include <net/if_clone.h>
99#include <net/route.h>
100#include <net/route/nhop.h>
101#include <net/netisr.h>
102#include <net/if_types.h>
103#include <net/vnet.h>
104
105#include <netinet/in.h>
106#include <netinet/in_fib.h>
107#include <netinet/in_systm.h>
108#include <netinet/ip.h>
109#include <netinet/ip_var.h>
110#include <netinet/in_var.h>
111
112#include <netinet/ip6.h>
113#include <netinet6/ip6_var.h>
114#include <netinet6/in6_var.h>
115#include <netinet/ip_ecn.h>
116
117#include <netinet/ip_encap.h>
118
119#include <machine/stdarg.h>
120
121#include <net/bpf.h>
122
123#include <security/mac/mac_framework.h>
124
125SYSCTL_DECL(_net_link);
126static SYSCTL_NODE(_net_link, IFT_STF, stf, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
127    "6to4 Interface");
128
129static int stf_permit_rfc1918 = 0;
130SYSCTL_INT(_net_link_stf, OID_AUTO, permit_rfc1918, CTLFLAG_RWTUN,
131    &stf_permit_rfc1918, 0, "Permit the use of private IPv4 addresses");
132
133#define STFUNIT		0
134
135#define IN6_IS_ADDR_6TO4(x)	(ntohs((x)->s6_addr16[0]) == 0x2002)
136
137/*
138 * XXX: Return a pointer with 16-bit aligned.  Don't cast it to
139 * struct in_addr *; use bcopy() instead.
140 */
141#define GET_V4(x)	(&(x)->s6_addr16[1])
142
143struct stf_softc {
144	struct ifnet	*sc_ifp;
145	u_int	sc_fibnum;
146	const struct encaptab *encap_cookie;
147};
148#define STF2IFP(sc)	((sc)->sc_ifp)
149
150static const char stfname[] = "stf";
151
152static MALLOC_DEFINE(M_STF, stfname, "6to4 Tunnel Interface");
153static const int ip_stf_ttl = 40;
154
155static int in_stf_input(struct mbuf *, int, int, void *);
156static char *stfnames[] = {"stf0", "stf", "6to4", NULL};
157
158static int stfmodevent(module_t, int, void *);
159static int stf_encapcheck(const struct mbuf *, int, int, void *);
160static int stf_getsrcifa6(struct ifnet *, struct in6_addr *, struct in6_addr *);
161static int stf_output(struct ifnet *, struct mbuf *, const struct sockaddr *,
162	struct route *);
163static int isrfc1918addr(struct in_addr *);
164static int stf_checkaddr4(struct stf_softc *, struct in_addr *,
165	struct ifnet *);
166static int stf_checkaddr6(struct stf_softc *, struct in6_addr *,
167	struct ifnet *);
168static int stf_ioctl(struct ifnet *, u_long, caddr_t);
169
170static int stf_clone_match(struct if_clone *, const char *);
171static int stf_clone_create(struct if_clone *, char *, size_t, caddr_t);
172static int stf_clone_destroy(struct if_clone *, struct ifnet *);
173static struct if_clone *stf_cloner;
174
175static const struct encap_config ipv4_encap_cfg = {
176	.proto = IPPROTO_IPV6,
177	.min_length = sizeof(struct ip),
178	.exact_match = (sizeof(in_addr_t) << 3) + 8,
179	.check = stf_encapcheck,
180	.input = in_stf_input
181};
182
183static int
184stf_clone_match(struct if_clone *ifc, const char *name)
185{
186	int i;
187
188	for(i = 0; stfnames[i] != NULL; i++) {
189		if (strcmp(stfnames[i], name) == 0)
190			return (1);
191	}
192
193	return (0);
194}
195
196static int
197stf_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
198{
199	char *dp;
200	int err, unit, wildcard;
201	struct stf_softc *sc;
202	struct ifnet *ifp;
203
204	err = ifc_name2unit(name, &unit);
205	if (err != 0)
206		return (err);
207	wildcard = (unit < 0);
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	 * In the wildcard case, we need to update the name.
233	 */
234	if (wildcard) {
235		for (dp = name; *dp != '\0'; dp++);
236		if (snprintf(dp, len - (dp-name), "%d", unit) >
237		    len - (dp-name) - 1) {
238			/*
239			 * This can only be a programmer error and
240			 * there's no straightforward way to recover if
241			 * it happens.
242			 */
243			panic("if_clone_create(): interface name too long");
244		}
245	}
246	strlcpy(ifp->if_xname, name, IFNAMSIZ);
247	ifp->if_dname = stfname;
248	ifp->if_dunit = IF_DUNIT_NONE;
249
250	sc->encap_cookie = ip_encap_attach(&ipv4_encap_cfg, sc, M_WAITOK);
251	if (sc->encap_cookie == NULL) {
252		if_printf(ifp, "attach failed\n");
253		free(sc, M_STF);
254		ifc_free_unit(ifc, unit);
255		return (ENOMEM);
256	}
257
258	ifp->if_mtu    = IPV6_MMTU;
259	ifp->if_ioctl  = stf_ioctl;
260	ifp->if_output = stf_output;
261	ifp->if_snd.ifq_maxlen = ifqmaxlen;
262	if_attach(ifp);
263	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
264	return (0);
265}
266
267static int
268stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
269{
270	struct stf_softc *sc = ifp->if_softc;
271	int err __unused;
272
273	err = ip_encap_detach(sc->encap_cookie);
274	KASSERT(err == 0, ("Unexpected error detaching encap_cookie"));
275	bpfdetach(ifp);
276	if_detach(ifp);
277	if_free(ifp);
278
279	free(sc, M_STF);
280	ifc_free_unit(ifc, STFUNIT);
281
282	return (0);
283}
284
285static int
286stfmodevent(module_t mod, int type, void *data)
287{
288
289	switch (type) {
290	case MOD_LOAD:
291		stf_cloner = if_clone_advanced(stfname, 0, stf_clone_match,
292		    stf_clone_create, stf_clone_destroy);
293		break;
294	case MOD_UNLOAD:
295		if_clone_detach(stf_cloner);
296		break;
297	default:
298		return (EOPNOTSUPP);
299	}
300
301	return (0);
302}
303
304static moduledata_t stf_mod = {
305	"if_stf",
306	stfmodevent,
307	0
308};
309
310DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
311
312static int
313stf_encapcheck(const struct mbuf *m, int off, int proto, void *arg)
314{
315	struct ip ip;
316	struct stf_softc *sc;
317	struct in_addr a, b, mask;
318	struct in6_addr addr6, mask6;
319
320	sc = (struct stf_softc *)arg;
321	if (sc == NULL)
322		return 0;
323
324	if ((STF2IFP(sc)->if_flags & IFF_UP) == 0)
325		return 0;
326
327	/* IFF_LINK0 means "no decapsulation" */
328	if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0)
329		return 0;
330
331	if (proto != IPPROTO_IPV6)
332		return 0;
333
334	m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
335
336	if (ip.ip_v != 4)
337		return 0;
338
339	if (stf_getsrcifa6(STF2IFP(sc), &addr6, &mask6) != 0)
340		return (0);
341
342	/*
343	 * check if IPv4 dst matches the IPv4 address derived from the
344	 * local 6to4 address.
345	 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:...
346	 */
347	if (bcmp(GET_V4(&addr6), &ip.ip_dst, sizeof(ip.ip_dst)) != 0)
348		return 0;
349
350	/*
351	 * check if IPv4 src matches the IPv4 address derived from the
352	 * local 6to4 address masked by prefixmask.
353	 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24
354	 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24
355	 */
356	bzero(&a, sizeof(a));
357	bcopy(GET_V4(&addr6), &a, sizeof(a));
358	bcopy(GET_V4(&mask6), &mask, sizeof(mask));
359	a.s_addr &= mask.s_addr;
360	b = ip.ip_src;
361	b.s_addr &= mask.s_addr;
362	if (a.s_addr != b.s_addr)
363		return 0;
364
365	/* stf interface makes single side match only */
366	return 32;
367}
368
369static int
370stf_getsrcifa6(struct ifnet *ifp, struct in6_addr *addr, struct in6_addr *mask)
371{
372	struct rm_priotracker in_ifa_tracker;
373	struct ifaddr *ia;
374	struct in_ifaddr *ia4;
375	struct in6_ifaddr *ia6;
376	struct sockaddr_in6 *sin6;
377	struct in_addr in;
378
379	NET_EPOCH_ASSERT();
380
381	CK_STAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
382		if (ia->ifa_addr->sa_family != AF_INET6)
383			continue;
384		sin6 = (struct sockaddr_in6 *)ia->ifa_addr;
385		if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr))
386			continue;
387
388		bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in));
389		IN_IFADDR_RLOCK(&in_ifa_tracker);
390		LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash)
391			if (ia4->ia_addr.sin_addr.s_addr == in.s_addr)
392				break;
393		IN_IFADDR_RUNLOCK(&in_ifa_tracker);
394		if (ia4 == NULL)
395			continue;
396
397		ia6 = (struct in6_ifaddr *)ia;
398
399		*addr = sin6->sin6_addr;
400		*mask = ia6->ia_prefixmask.sin6_addr;
401		return (0);
402	}
403
404	return (ENOENT);
405}
406
407static int
408stf_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
409    struct route *ro)
410{
411	struct stf_softc *sc;
412	const struct sockaddr_in6 *dst6;
413	struct in_addr in4;
414	const void *ptr;
415	u_int8_t tos;
416	struct ip *ip;
417	struct ip6_hdr *ip6;
418	struct in6_addr addr6, mask6;
419	int error;
420
421#ifdef MAC
422	error = mac_ifnet_check_transmit(ifp, m);
423	if (error) {
424		m_freem(m);
425		return (error);
426	}
427#endif
428
429	sc = ifp->if_softc;
430	dst6 = (const struct sockaddr_in6 *)dst;
431
432	/* just in case */
433	if ((ifp->if_flags & IFF_UP) == 0) {
434		m_freem(m);
435		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
436		return ENETDOWN;
437	}
438
439	/*
440	 * If we don't have an ip4 address that match my inner ip6 address,
441	 * we shouldn't generate output.  Without this check, we'll end up
442	 * using wrong IPv4 source.
443	 */
444	if (stf_getsrcifa6(ifp, &addr6, &mask6) != 0) {
445		m_freem(m);
446		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
447		return ENETDOWN;
448	}
449
450	if (m->m_len < sizeof(*ip6)) {
451		m = m_pullup(m, sizeof(*ip6));
452		if (!m) {
453			if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
454			return ENOBUFS;
455		}
456	}
457	ip6 = mtod(m, struct ip6_hdr *);
458	tos = IPV6_TRAFFIC_CLASS(ip6);
459
460	/*
461	 * Pickup the right outer dst addr from the list of candidates.
462	 * ip6_dst has priority as it may be able to give us shorter IPv4 hops.
463	 */
464	ptr = NULL;
465	if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst))
466		ptr = GET_V4(&ip6->ip6_dst);
467	else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr))
468		ptr = GET_V4(&dst6->sin6_addr);
469	else {
470		m_freem(m);
471		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
472		return ENETUNREACH;
473	}
474	bcopy(ptr, &in4, sizeof(in4));
475
476	if (bpf_peers_present(ifp->if_bpf)) {
477		/*
478		 * We need to prepend the address family as
479		 * a four byte field.  Cons up a dummy header
480		 * to pacify bpf.  This is safe because bpf
481		 * will only read from the mbuf (i.e., it won't
482		 * try to free it or keep a pointer a to it).
483		 */
484		u_int af = AF_INET6;
485		bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
486	}
487
488	M_PREPEND(m, sizeof(struct ip), M_NOWAIT);
489	if (m == NULL) {
490		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
491		return ENOBUFS;
492	}
493	ip = mtod(m, struct ip *);
494
495	bzero(ip, sizeof(*ip));
496
497	bcopy(GET_V4(&addr6), &ip->ip_src, sizeof(ip->ip_src));
498	bcopy(&in4, &ip->ip_dst, sizeof(ip->ip_dst));
499	ip->ip_p = IPPROTO_IPV6;
500	ip->ip_ttl = ip_stf_ttl;
501	ip->ip_len = htons(m->m_pkthdr.len);
502	if (ifp->if_flags & IFF_LINK1)
503		ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos);
504	else
505		ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos);
506
507	M_SETFIB(m, sc->sc_fibnum);
508	if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
509	error = ip_output(m, NULL, NULL, 0, NULL, NULL);
510
511	return error;
512}
513
514static int
515isrfc1918addr(struct in_addr *in)
516{
517	/*
518	 * returns 1 if private address range:
519	 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16
520	 */
521	if (stf_permit_rfc1918 == 0 && (
522	    (ntohl(in->s_addr) & 0xff000000) >> 24 == 10 ||
523	    (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 ||
524	    (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168))
525		return 1;
526
527	return 0;
528}
529
530static int
531stf_checkaddr4(struct stf_softc *sc, struct in_addr *in, struct ifnet *inifp)
532{
533	struct rm_priotracker in_ifa_tracker;
534	struct in_ifaddr *ia4;
535
536	/*
537	 * reject packets with the following address:
538	 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8
539	 */
540	if (IN_MULTICAST(ntohl(in->s_addr)))
541		return -1;
542	switch ((ntohl(in->s_addr) & 0xff000000) >> 24) {
543	case 0: case 127: case 255:
544		return -1;
545	}
546
547	/*
548	 * reject packets with private address range.
549	 * (requirement from RFC3056 section 2 1st paragraph)
550	 */
551	if (isrfc1918addr(in))
552		return -1;
553
554	/*
555	 * reject packets with broadcast
556	 */
557	IN_IFADDR_RLOCK(&in_ifa_tracker);
558	CK_STAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) {
559		if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
560			continue;
561		if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) {
562			IN_IFADDR_RUNLOCK(&in_ifa_tracker);
563			return -1;
564		}
565	}
566	IN_IFADDR_RUNLOCK(&in_ifa_tracker);
567
568	/*
569	 * perform ingress filter
570	 */
571	if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) {
572		struct nhop_object *nh;
573
574		NET_EPOCH_ASSERT();
575		nh = fib4_lookup(sc->sc_fibnum, *in, 0, 0, 0);
576		if (nh == NULL)
577			return (-1);
578
579		if (nh->nh_ifp != inifp)
580			return (-1);
581	}
582
583	return 0;
584}
585
586static int
587stf_checkaddr6(struct stf_softc *sc, struct in6_addr *in6, struct ifnet *inifp)
588{
589	/*
590	 * check 6to4 addresses
591	 */
592	if (IN6_IS_ADDR_6TO4(in6)) {
593		struct in_addr in4;
594		bcopy(GET_V4(in6), &in4, sizeof(in4));
595		return stf_checkaddr4(sc, &in4, inifp);
596	}
597
598	/*
599	 * reject anything that look suspicious.  the test is implemented
600	 * in ip6_input too, but we check here as well to
601	 * (1) reject bad packets earlier, and
602	 * (2) to be safe against future ip6_input change.
603	 */
604	if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6))
605		return -1;
606
607	return 0;
608}
609
610static int
611in_stf_input(struct mbuf *m, int off, int proto, void *arg)
612{
613	struct stf_softc *sc = arg;
614	struct ip *ip;
615	struct ip6_hdr *ip6;
616	u_int8_t otos, itos;
617	struct ifnet *ifp;
618
619	NET_EPOCH_ASSERT();
620
621	if (proto != IPPROTO_IPV6) {
622		m_freem(m);
623		return (IPPROTO_DONE);
624	}
625
626	ip = mtod(m, struct ip *);
627	if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) {
628		m_freem(m);
629		return (IPPROTO_DONE);
630	}
631
632	ifp = STF2IFP(sc);
633
634#ifdef MAC
635	mac_ifnet_create_mbuf(ifp, m);
636#endif
637
638	/*
639	 * perform sanity check against outer src/dst.
640	 * for source, perform ingress filter as well.
641	 */
642	if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 ||
643	    stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) {
644		m_freem(m);
645		return (IPPROTO_DONE);
646	}
647
648	otos = ip->ip_tos;
649	m_adj(m, off);
650
651	if (m->m_len < sizeof(*ip6)) {
652		m = m_pullup(m, sizeof(*ip6));
653		if (!m)
654			return (IPPROTO_DONE);
655	}
656	ip6 = mtod(m, struct ip6_hdr *);
657
658	/*
659	 * perform sanity check against inner src/dst.
660	 * for source, perform ingress filter as well.
661	 */
662	if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 ||
663	    stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) {
664		m_freem(m);
665		return (IPPROTO_DONE);
666	}
667
668	itos = IPV6_TRAFFIC_CLASS(ip6);
669	if ((ifp->if_flags & IFF_LINK1) != 0)
670		ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
671	else
672		ip_ecn_egress(ECN_NOCARE, &otos, &itos);
673	ip6->ip6_flow &= ~htonl(0xff << 20);
674	ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
675
676	m->m_pkthdr.rcvif = ifp;
677
678	if (bpf_peers_present(ifp->if_bpf)) {
679		/*
680		 * We need to prepend the address family as
681		 * a four byte field.  Cons up a dummy header
682		 * to pacify bpf.  This is safe because bpf
683		 * will only read from the mbuf (i.e., it won't
684		 * try to free it or keep a pointer a to it).
685		 */
686		u_int32_t af = AF_INET6;
687		bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
688	}
689
690	/*
691	 * Put the packet to the network layer input queue according to the
692	 * specified address family.
693	 * See net/if_gif.c for possible issues with packet processing
694	 * reorder due to extra queueing.
695	 */
696	if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
697	if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
698	M_SETFIB(m, ifp->if_fib);
699	netisr_dispatch(NETISR_IPV6, m);
700	return (IPPROTO_DONE);
701}
702
703static int
704stf_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
705{
706	struct ifaddr *ifa;
707	struct ifreq *ifr;
708	struct sockaddr_in6 *sin6;
709	struct in_addr addr;
710	int error, mtu;
711
712	error = 0;
713	switch (cmd) {
714	case SIOCSIFADDR:
715		ifa = (struct ifaddr *)data;
716		if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) {
717			error = EAFNOSUPPORT;
718			break;
719		}
720		sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
721		if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) {
722			error = EINVAL;
723			break;
724		}
725		bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr));
726		if (isrfc1918addr(&addr)) {
727			error = EINVAL;
728			break;
729		}
730
731		ifp->if_flags |= IFF_UP;
732		ifp->if_drv_flags |= IFF_DRV_RUNNING;
733		break;
734
735	case SIOCADDMULTI:
736	case SIOCDELMULTI:
737		ifr = (struct ifreq *)data;
738		if (ifr && ifr->ifr_addr.sa_family == AF_INET6)
739			;
740		else
741			error = EAFNOSUPPORT;
742		break;
743
744	case SIOCGIFMTU:
745		break;
746
747	case SIOCSIFMTU:
748		ifr = (struct ifreq *)data;
749		mtu = ifr->ifr_mtu;
750		/* RFC 4213 3.2 ideal world MTU */
751		if (mtu < IPV6_MINMTU || mtu > IF_MAXMTU - 20)
752			return (EINVAL);
753		ifp->if_mtu = mtu;
754		break;
755
756	default:
757		error = EINVAL;
758		break;
759	}
760
761	return error;
762}
763