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/netisr.h>
101 #include <net/if_types.h>
102 #include <net/vnet.h>
103
104 #include <netinet/in.h>
105 #include <netinet/in_fib.h>
106 #include <netinet/in_systm.h>
107 #include <netinet/ip.h>
108 #include <netinet/ip_var.h>
109 #include <netinet/in_var.h>
110
111 #include <netinet/ip6.h>
112 #include <netinet6/ip6_var.h>
113 #include <netinet6/in6_var.h>
114 #include <netinet/ip_ecn.h>
115
116 #include <netinet/ip_encap.h>
117
118 #include <machine/stdarg.h>
119
120 #include <net/bpf.h>
121
122 #include <security/mac/mac_framework.h>
123
124 SYSCTL_DECL(_net_link);
125 static SYSCTL_NODE(_net_link, IFT_STF, stf, CTLFLAG_RW, 0, "6to4 Interface");
126
127 static int stf_permit_rfc1918 = 0;
128 SYSCTL_INT(_net_link_stf, OID_AUTO, permit_rfc1918, CTLFLAG_RWTUN,
129 &stf_permit_rfc1918, 0, "Permit the use of private IPv4 addresses");
130
131 #define STFUNIT 0
132
133 #define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002)
134
135 /*
136 * XXX: Return a pointer with 16-bit aligned. Don't cast it to
137 * struct in_addr *; use bcopy() instead.
138 */
139 #define GET_V4(x) (&(x)->s6_addr16[1])
140
141 struct stf_softc {
142 struct ifnet *sc_ifp;
143 u_int sc_fibnum;
144 const struct encaptab *encap_cookie;
145 };
146 #define STF2IFP(sc) ((sc)->sc_ifp)
147
148 static const char stfname[] = "stf";
149
150 static MALLOC_DEFINE(M_STF, stfname, "6to4 Tunnel Interface");
151 static const int ip_stf_ttl = 40;
152
153 static int in_stf_input(struct mbuf *, int, int, void *);
154 static char *stfnames[] = {"stf0", "stf", "6to4", NULL};
155
156 static int stfmodevent(module_t, int, void *);
157 static int stf_encapcheck(const struct mbuf *, int, int, void *);
158 static int stf_getsrcifa6(struct ifnet *, struct in6_addr *, struct in6_addr *);
159 static int stf_output(struct ifnet *, struct mbuf *, const struct sockaddr *,
160 struct route *);
161 static int isrfc1918addr(struct in_addr *);
162 static int stf_checkaddr4(struct stf_softc *, struct in_addr *,
163 struct ifnet *);
164 static int stf_checkaddr6(struct stf_softc *, struct in6_addr *,
165 struct ifnet *);
166 static int stf_ioctl(struct ifnet *, u_long, caddr_t);
167
168 static int stf_clone_match(struct if_clone *, const char *);
169 static int stf_clone_create(struct if_clone *, char *, size_t, caddr_t);
170 static int stf_clone_destroy(struct if_clone *, struct ifnet *);
171 static struct if_clone *stf_cloner;
172
173 static const struct encap_config ipv4_encap_cfg = {
174 .proto = IPPROTO_IPV6,
175 .min_length = sizeof(struct ip),
176 .exact_match = (sizeof(in_addr_t) << 3) + 8,
177 .check = stf_encapcheck,
178 .input = in_stf_input
179 };
180
181 static int
stf_clone_match(struct if_clone * ifc,const char * name)182 stf_clone_match(struct if_clone *ifc, const char *name)
183 {
184 int i;
185
186 for(i = 0; stfnames[i] != NULL; i++) {
187 if (strcmp(stfnames[i], name) == 0)
188 return (1);
189 }
190
191 return (0);
192 }
193
194 static int
stf_clone_create(struct if_clone * ifc,char * name,size_t len,caddr_t params)195 stf_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
196 {
197 char *dp;
198 int err, unit, wildcard;
199 struct stf_softc *sc;
200 struct ifnet *ifp;
201
202 err = ifc_name2unit(name, &unit);
203 if (err != 0)
204 return (err);
205 wildcard = (unit < 0);
206
207 /*
208 * We can only have one unit, but since unit allocation is
209 * already locked, we use it to keep from allocating extra
210 * interfaces.
211 */
212 unit = STFUNIT;
213 err = ifc_alloc_unit(ifc, &unit);
214 if (err != 0)
215 return (err);
216
217 sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO);
218 ifp = STF2IFP(sc) = if_alloc(IFT_STF);
219 if (ifp == NULL) {
220 free(sc, M_STF);
221 ifc_free_unit(ifc, unit);
222 return (ENOSPC);
223 }
224 ifp->if_softc = sc;
225 sc->sc_fibnum = curthread->td_proc->p_fibnum;
226
227 /*
228 * Set the name manually rather then using if_initname because
229 * we don't conform to the default naming convention for interfaces.
230 * In the wildcard case, we need to update the name.
231 */
232 if (wildcard) {
233 for (dp = name; *dp != '\0'; dp++);
234 if (snprintf(dp, len - (dp-name), "%d", unit) >
235 len - (dp-name) - 1) {
236 /*
237 * This can only be a programmer error and
238 * there's no straightforward way to recover if
239 * it happens.
240 */
241 panic("if_clone_create(): interface name too long");
242 }
243 }
244 strlcpy(ifp->if_xname, name, IFNAMSIZ);
245 ifp->if_dname = stfname;
246 ifp->if_dunit = IF_DUNIT_NONE;
247
248 sc->encap_cookie = ip_encap_attach(&ipv4_encap_cfg, sc, M_WAITOK);
249 if (sc->encap_cookie == NULL) {
250 if_printf(ifp, "attach failed\n");
251 free(sc, M_STF);
252 ifc_free_unit(ifc, unit);
253 return (ENOMEM);
254 }
255
256 ifp->if_mtu = IPV6_MMTU;
257 ifp->if_ioctl = stf_ioctl;
258 ifp->if_output = stf_output;
259 ifp->if_snd.ifq_maxlen = ifqmaxlen;
260 if_attach(ifp);
261 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
262 return (0);
263 }
264
265 static int
stf_clone_destroy(struct if_clone * ifc,struct ifnet * ifp)266 stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
267 {
268 struct stf_softc *sc = ifp->if_softc;
269 int err __unused;
270
271 err = ip_encap_detach(sc->encap_cookie);
272 KASSERT(err == 0, ("Unexpected error detaching encap_cookie"));
273 bpfdetach(ifp);
274 if_detach(ifp);
275 if_free(ifp);
276
277 free(sc, M_STF);
278 ifc_free_unit(ifc, STFUNIT);
279
280 return (0);
281 }
282
283 static int
stfmodevent(module_t mod,int type,void * data)284 stfmodevent(module_t mod, int type, void *data)
285 {
286
287 switch (type) {
288 case MOD_LOAD:
289 stf_cloner = if_clone_advanced(stfname, 0, stf_clone_match,
290 stf_clone_create, stf_clone_destroy);
291 break;
292 case MOD_UNLOAD:
293 if_clone_detach(stf_cloner);
294 break;
295 default:
296 return (EOPNOTSUPP);
297 }
298
299 return (0);
300 }
301
302 static moduledata_t stf_mod = {
303 "if_stf",
304 stfmodevent,
305 0
306 };
307
308 DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
309
310 static int
stf_encapcheck(const struct mbuf * m,int off,int proto,void * arg)311 stf_encapcheck(const struct mbuf *m, int off, int proto, void *arg)
312 {
313 struct ip ip;
314 struct stf_softc *sc;
315 struct in_addr a, b, mask;
316 struct in6_addr addr6, mask6;
317
318 sc = (struct stf_softc *)arg;
319 if (sc == NULL)
320 return 0;
321
322 if ((STF2IFP(sc)->if_flags & IFF_UP) == 0)
323 return 0;
324
325 /* IFF_LINK0 means "no decapsulation" */
326 if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0)
327 return 0;
328
329 if (proto != IPPROTO_IPV6)
330 return 0;
331
332 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
333
334 if (ip.ip_v != 4)
335 return 0;
336
337 if (stf_getsrcifa6(STF2IFP(sc), &addr6, &mask6) != 0)
338 return (0);
339
340 /*
341 * check if IPv4 dst matches the IPv4 address derived from the
342 * local 6to4 address.
343 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:...
344 */
345 if (bcmp(GET_V4(&addr6), &ip.ip_dst, sizeof(ip.ip_dst)) != 0)
346 return 0;
347
348 /*
349 * check if IPv4 src matches the IPv4 address derived from the
350 * local 6to4 address masked by prefixmask.
351 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24
352 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24
353 */
354 bzero(&a, sizeof(a));
355 bcopy(GET_V4(&addr6), &a, sizeof(a));
356 bcopy(GET_V4(&mask6), &mask, sizeof(mask));
357 a.s_addr &= mask.s_addr;
358 b = ip.ip_src;
359 b.s_addr &= mask.s_addr;
360 if (a.s_addr != b.s_addr)
361 return 0;
362
363 /* stf interface makes single side match only */
364 return 32;
365 }
366
367 static int
stf_getsrcifa6(struct ifnet * ifp,struct in6_addr * addr,struct in6_addr * mask)368 stf_getsrcifa6(struct ifnet *ifp, struct in6_addr *addr, struct in6_addr *mask)
369 {
370 struct rm_priotracker in_ifa_tracker;
371 struct ifaddr *ia;
372 struct in_ifaddr *ia4;
373 struct in6_ifaddr *ia6;
374 struct sockaddr_in6 *sin6;
375 struct in_addr in;
376
377 if_addr_rlock(ifp);
378 CK_STAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
379 if (ia->ifa_addr->sa_family != AF_INET6)
380 continue;
381 sin6 = (struct sockaddr_in6 *)ia->ifa_addr;
382 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr))
383 continue;
384
385 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in));
386 IN_IFADDR_RLOCK(&in_ifa_tracker);
387 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash)
388 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr)
389 break;
390 IN_IFADDR_RUNLOCK(&in_ifa_tracker);
391 if (ia4 == NULL)
392 continue;
393
394 ia6 = (struct in6_ifaddr *)ia;
395
396 *addr = sin6->sin6_addr;
397 *mask = ia6->ia_prefixmask.sin6_addr;
398 if_addr_runlock(ifp);
399 return (0);
400 }
401 if_addr_runlock(ifp);
402
403 return (ENOENT);
404 }
405
406 static int
stf_output(struct ifnet * ifp,struct mbuf * m,const struct sockaddr * dst,struct route * ro)407 stf_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
408 struct route *ro)
409 {
410 struct stf_softc *sc;
411 const struct sockaddr_in6 *dst6;
412 struct in_addr in4;
413 const void *ptr;
414 u_int8_t tos;
415 struct ip *ip;
416 struct ip6_hdr *ip6;
417 struct in6_addr addr6, mask6;
418 int error;
419
420 #ifdef MAC
421 error = mac_ifnet_check_transmit(ifp, m);
422 if (error) {
423 m_freem(m);
424 return (error);
425 }
426 #endif
427
428 sc = ifp->if_softc;
429 dst6 = (const struct sockaddr_in6 *)dst;
430
431 /* just in case */
432 if ((ifp->if_flags & IFF_UP) == 0) {
433 m_freem(m);
434 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
435 return ENETDOWN;
436 }
437
438 /*
439 * If we don't have an ip4 address that match my inner ip6 address,
440 * we shouldn't generate output. Without this check, we'll end up
441 * using wrong IPv4 source.
442 */
443 if (stf_getsrcifa6(ifp, &addr6, &mask6) != 0) {
444 m_freem(m);
445 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
446 return ENETDOWN;
447 }
448
449 if (m->m_len < sizeof(*ip6)) {
450 m = m_pullup(m, sizeof(*ip6));
451 if (!m) {
452 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
453 return ENOBUFS;
454 }
455 }
456 ip6 = mtod(m, struct ip6_hdr *);
457 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
458
459 /*
460 * Pickup the right outer dst addr from the list of candidates.
461 * ip6_dst has priority as it may be able to give us shorter IPv4 hops.
462 */
463 ptr = NULL;
464 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst))
465 ptr = GET_V4(&ip6->ip6_dst);
466 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr))
467 ptr = GET_V4(&dst6->sin6_addr);
468 else {
469 m_freem(m);
470 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
471 return ENETUNREACH;
472 }
473 bcopy(ptr, &in4, sizeof(in4));
474
475 if (bpf_peers_present(ifp->if_bpf)) {
476 /*
477 * We need to prepend the address family as
478 * a four byte field. Cons up a dummy header
479 * to pacify bpf. This is safe because bpf
480 * will only read from the mbuf (i.e., it won't
481 * try to free it or keep a pointer a to it).
482 */
483 u_int af = AF_INET6;
484 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
485 }
486
487 M_PREPEND(m, sizeof(struct ip), M_NOWAIT);
488 if (m == NULL) {
489 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
490 return ENOBUFS;
491 }
492 ip = mtod(m, struct ip *);
493
494 bzero(ip, sizeof(*ip));
495
496 bcopy(GET_V4(&addr6), &ip->ip_src, sizeof(ip->ip_src));
497 bcopy(&in4, &ip->ip_dst, sizeof(ip->ip_dst));
498 ip->ip_p = IPPROTO_IPV6;
499 ip->ip_ttl = ip_stf_ttl;
500 ip->ip_len = htons(m->m_pkthdr.len);
501 if (ifp->if_flags & IFF_LINK1)
502 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos);
503 else
504 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos);
505
506 M_SETFIB(m, sc->sc_fibnum);
507 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
508 error = ip_output(m, NULL, NULL, 0, NULL, NULL);
509
510 return error;
511 }
512
513 static int
isrfc1918addr(struct in_addr * in)514 isrfc1918addr(struct in_addr *in)
515 {
516 /*
517 * returns 1 if private address range:
518 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16
519 */
520 if (stf_permit_rfc1918 == 0 && (
521 (ntohl(in->s_addr) & 0xff000000) >> 24 == 10 ||
522 (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 ||
523 (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168))
524 return 1;
525
526 return 0;
527 }
528
529 static int
stf_checkaddr4(struct stf_softc * sc,struct in_addr * in,struct ifnet * inifp)530 stf_checkaddr4(struct stf_softc *sc, struct in_addr *in, struct ifnet *inifp)
531 {
532 struct rm_priotracker in_ifa_tracker;
533 struct in_ifaddr *ia4;
534
535 /*
536 * reject packets with the following address:
537 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8
538 */
539 if (IN_MULTICAST(ntohl(in->s_addr)))
540 return -1;
541 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) {
542 case 0: case 127: case 255:
543 return -1;
544 }
545
546 /*
547 * reject packets with private address range.
548 * (requirement from RFC3056 section 2 1st paragraph)
549 */
550 if (isrfc1918addr(in))
551 return -1;
552
553 /*
554 * reject packets with broadcast
555 */
556 IN_IFADDR_RLOCK(&in_ifa_tracker);
557 CK_STAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) {
558 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
559 continue;
560 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) {
561 IN_IFADDR_RUNLOCK(&in_ifa_tracker);
562 return -1;
563 }
564 }
565 IN_IFADDR_RUNLOCK(&in_ifa_tracker);
566
567 /*
568 * perform ingress filter
569 */
570 if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) {
571 struct nhop4_basic nh4;
572
573 if (fib4_lookup_nh_basic(sc->sc_fibnum, *in, 0, 0, &nh4) != 0)
574 return (-1);
575
576 if (nh4.nh_ifp != inifp)
577 return (-1);
578 }
579
580 return 0;
581 }
582
583 static int
stf_checkaddr6(struct stf_softc * sc,struct in6_addr * in6,struct ifnet * inifp)584 stf_checkaddr6(struct stf_softc *sc, struct in6_addr *in6, struct ifnet *inifp)
585 {
586 /*
587 * check 6to4 addresses
588 */
589 if (IN6_IS_ADDR_6TO4(in6)) {
590 struct in_addr in4;
591 bcopy(GET_V4(in6), &in4, sizeof(in4));
592 return stf_checkaddr4(sc, &in4, inifp);
593 }
594
595 /*
596 * reject anything that look suspicious. the test is implemented
597 * in ip6_input too, but we check here as well to
598 * (1) reject bad packets earlier, and
599 * (2) to be safe against future ip6_input change.
600 */
601 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6))
602 return -1;
603
604 return 0;
605 }
606
607 static int
in_stf_input(struct mbuf * m,int off,int proto,void * arg)608 in_stf_input(struct mbuf *m, int off, int proto, void *arg)
609 {
610 struct stf_softc *sc = arg;
611 struct ip *ip;
612 struct ip6_hdr *ip6;
613 u_int8_t otos, itos;
614 struct ifnet *ifp;
615
616 if (proto != IPPROTO_IPV6) {
617 m_freem(m);
618 return (IPPROTO_DONE);
619 }
620
621 ip = mtod(m, struct ip *);
622 if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) {
623 m_freem(m);
624 return (IPPROTO_DONE);
625 }
626
627 ifp = STF2IFP(sc);
628
629 #ifdef MAC
630 mac_ifnet_create_mbuf(ifp, m);
631 #endif
632
633 /*
634 * perform sanity check against outer src/dst.
635 * for source, perform ingress filter as well.
636 */
637 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 ||
638 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) {
639 m_freem(m);
640 return (IPPROTO_DONE);
641 }
642
643 otos = ip->ip_tos;
644 m_adj(m, off);
645
646 if (m->m_len < sizeof(*ip6)) {
647 m = m_pullup(m, sizeof(*ip6));
648 if (!m)
649 return (IPPROTO_DONE);
650 }
651 ip6 = mtod(m, struct ip6_hdr *);
652
653 /*
654 * perform sanity check against inner src/dst.
655 * for source, perform ingress filter as well.
656 */
657 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 ||
658 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) {
659 m_freem(m);
660 return (IPPROTO_DONE);
661 }
662
663 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
664 if ((ifp->if_flags & IFF_LINK1) != 0)
665 ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
666 else
667 ip_ecn_egress(ECN_NOCARE, &otos, &itos);
668 ip6->ip6_flow &= ~htonl(0xff << 20);
669 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
670
671 m->m_pkthdr.rcvif = ifp;
672
673 if (bpf_peers_present(ifp->if_bpf)) {
674 /*
675 * We need to prepend the address family as
676 * a four byte field. Cons up a dummy header
677 * to pacify bpf. This is safe because bpf
678 * will only read from the mbuf (i.e., it won't
679 * try to free it or keep a pointer a to it).
680 */
681 u_int32_t af = AF_INET6;
682 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
683 }
684
685 /*
686 * Put the packet to the network layer input queue according to the
687 * specified address family.
688 * See net/if_gif.c for possible issues with packet processing
689 * reorder due to extra queueing.
690 */
691 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
692 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
693 M_SETFIB(m, ifp->if_fib);
694 netisr_dispatch(NETISR_IPV6, m);
695 return (IPPROTO_DONE);
696 }
697
698 static int
stf_ioctl(struct ifnet * ifp,u_long cmd,caddr_t data)699 stf_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
700 {
701 struct ifaddr *ifa;
702 struct ifreq *ifr;
703 struct sockaddr_in6 *sin6;
704 struct in_addr addr;
705 int error, mtu;
706
707 error = 0;
708 switch (cmd) {
709 case SIOCSIFADDR:
710 ifa = (struct ifaddr *)data;
711 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) {
712 error = EAFNOSUPPORT;
713 break;
714 }
715 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
716 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) {
717 error = EINVAL;
718 break;
719 }
720 bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr));
721 if (isrfc1918addr(&addr)) {
722 error = EINVAL;
723 break;
724 }
725
726 ifp->if_flags |= IFF_UP;
727 ifp->if_drv_flags |= IFF_DRV_RUNNING;
728 break;
729
730 case SIOCADDMULTI:
731 case SIOCDELMULTI:
732 ifr = (struct ifreq *)data;
733 if (ifr && ifr->ifr_addr.sa_family == AF_INET6)
734 ;
735 else
736 error = EAFNOSUPPORT;
737 break;
738
739 case SIOCGIFMTU:
740 break;
741
742 case SIOCSIFMTU:
743 ifr = (struct ifreq *)data;
744 mtu = ifr->ifr_mtu;
745 /* RFC 4213 3.2 ideal world MTU */
746 if (mtu < IPV6_MINMTU || mtu > IF_MAXMTU - 20)
747 return (EINVAL);
748 ifp->if_mtu = mtu;
749 break;
750
751 default:
752 error = EINVAL;
753 break;
754 }
755
756 return error;
757 }
758