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 "opt_inet.h"
78#include "opt_inet6.h"
79#include "opt_mac.h"
80
81#include <sys/param.h>
82#include <sys/systm.h>
83#include <sys/socket.h>
84#include <sys/sockio.h>
85#include <sys/mbuf.h>
86#include <sys/errno.h>
87#include <sys/kernel.h>
88#include <sys/module.h>
89#include <sys/protosw.h>
90#include <sys/queue.h>
91#include <machine/cpu.h>
92
93#include <sys/malloc.h>
94
95#include <net/if.h>
96#include <net/if_clone.h>
97#include <net/route.h>
98#include <net/netisr.h>
99#include <net/if_types.h>
100#include <net/if_stf.h>
101
102#include <netinet/in.h>
103#include <netinet/in_systm.h>
104#include <netinet/ip.h>
105#include <netinet/ip_var.h>
106#include <netinet/in_var.h>
107
108#include <netinet/ip6.h>
109#include <netinet6/ip6_var.h>
110#include <netinet6/in6_var.h>
111#include <netinet/ip_ecn.h>
112
113#include <netinet/ip_encap.h>
114
115#include <machine/stdarg.h>
116
117#include <net/bpf.h>
118
119#include <security/mac/mac_framework.h>
120
121#define STFNAME "stf"
122#define STFUNIT 0
123
124#define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002)
125
126/*
127 * XXX: Return a pointer with 16-bit aligned. Don't cast it to
128 * struct in_addr *; use bcopy() instead.
129 */
130#define GET_V4(x) ((caddr_t)(&(x)->s6_addr16[1]))
131
132struct stf_softc {
133 struct ifnet *sc_ifp;
134 union {
135 struct route __sc_ro4;
136 struct route_in6 __sc_ro6; /* just for safety */
137 } __sc_ro46;
138#define sc_ro __sc_ro46.__sc_ro4
139 const struct encaptab *encap_cookie;
140};
141#define STF2IFP(sc) ((sc)->sc_ifp)
142
143/*
144 * XXXRW: Note that mutable fields in the softc are not currently locked:
145 * in particular, sc_ro needs to be protected from concurrent entrance
146 * of stf_output().
147 */
148static MALLOC_DEFINE(M_STF, STFNAME, "6to4 Tunnel Interface");
149static const int ip_stf_ttl = 40;
150
151extern struct domain inetdomain;
152struct protosw in_stf_protosw = {
153 .pr_type = SOCK_RAW,
154 .pr_domain = &inetdomain,
155 .pr_protocol = IPPROTO_IPV6,
156 .pr_flags = PR_ATOMIC|PR_ADDR,
157 .pr_input = in_stf_input,
158 .pr_output = (pr_output_t *)rip_output,
159 .pr_ctloutput = rip_ctloutput,
160 .pr_usrreqs = &rip_usrreqs
161};
162
163static char *stfnames[] = {"stf0", "stf", "6to4", NULL};
164
165static int stfmodevent(module_t, int, void *);
166static int stf_encapcheck(const struct mbuf *, int, int, void *);
167static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *);
168static int stf_output(struct ifnet *, struct mbuf *, struct sockaddr *,
169 struct rtentry *);
170static int isrfc1918addr(struct in_addr *);
171static int stf_checkaddr4(struct stf_softc *, struct in_addr *,
172 struct ifnet *);
173static int stf_checkaddr6(struct stf_softc *, struct in6_addr *,
174 struct ifnet *);
175static void stf_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
176static int stf_ioctl(struct ifnet *, u_long, caddr_t);
177
178static int stf_clone_match(struct if_clone *, const char *);
179static int stf_clone_create(struct if_clone *, char *, size_t, caddr_t);
180static int stf_clone_destroy(struct if_clone *, struct ifnet *);
181struct if_clone stf_cloner = IFC_CLONE_INITIALIZER(STFNAME, NULL, 0,
182 NULL, stf_clone_match, stf_clone_create, stf_clone_destroy);
183
184static int
185stf_clone_match(struct if_clone *ifc, const char *name)
186{
187 int i;
188
189 for(i = 0; stfnames[i] != NULL; i++) {
190 if (strcmp(stfnames[i], name) == 0)
191 return (1);
192 }
193
194 return (0);
195}
196
197static int
198stf_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
199{
200 int err, unit;
201 struct stf_softc *sc;
202 struct ifnet *ifp;
203
204 /*
205 * We can only have one unit, but since unit allocation is
206 * already locked, we use it to keep from allocating extra
207 * interfaces.
208 */
209 unit = STFUNIT;
210 err = ifc_alloc_unit(ifc, &unit);
211 if (err != 0)
212 return (err);
213
214 sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO);
215 ifp = STF2IFP(sc) = if_alloc(IFT_STF);
216 if (ifp == NULL) {
217 free(sc, M_STF);
218 ifc_free_unit(ifc, unit);
219 return (ENOSPC);
220 }
221 ifp->if_softc = sc;
222
223 /*
224 * Set the name manually rather then using if_initname because
225 * we don't conform to the default naming convention for interfaces.
226 */
227 strlcpy(ifp->if_xname, name, IFNAMSIZ);
228 ifp->if_dname = ifc->ifc_name;
229 ifp->if_dunit = IF_DUNIT_NONE;
230
231 sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6,
232 stf_encapcheck, &in_stf_protosw, sc);
233 if (sc->encap_cookie == NULL) {
234 if_printf(ifp, "attach failed\n");
235 free(sc, M_STF);
236 ifc_free_unit(ifc, unit);
237 return (ENOMEM);
238 }
239
240 ifp->if_mtu = IPV6_MMTU;
241 ifp->if_ioctl = stf_ioctl;
242 ifp->if_output = stf_output;
243 ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
244 if_attach(ifp);
245 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
246 return (0);
247}
248
249static int
250stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
251{
252 struct stf_softc *sc = ifp->if_softc;
253 int err;
254
255 err = encap_detach(sc->encap_cookie);
256 KASSERT(err == 0, ("Unexpected error detaching encap_cookie"));
257 bpfdetach(ifp);
258 if_detach(ifp);
259 if_free(ifp);
260
261 free(sc, M_STF);
262 ifc_free_unit(ifc, STFUNIT);
263
264 return (0);
265}
266
267static int
268stfmodevent(mod, type, data)
269 module_t mod;
270 int type;
271 void *data;
272{
273
274 switch (type) {
275 case MOD_LOAD:
276 if_clone_attach(&stf_cloner);
277 break;
278 case MOD_UNLOAD:
279 if_clone_detach(&stf_cloner);
280 break;
281 default:
282 return (EOPNOTSUPP);
283 }
284
285 return (0);
286}
287
288static moduledata_t stf_mod = {
289 "if_stf",
290 stfmodevent,
291 0
292};
293
294DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
295
296static int
297stf_encapcheck(m, off, proto, arg)
298 const struct mbuf *m;
299 int off;
300 int proto;
301 void *arg;
302{
303 struct ip ip;
304 struct in6_ifaddr *ia6;
305 struct stf_softc *sc;
306 struct in_addr a, b, mask;
307
308 sc = (struct stf_softc *)arg;
309 if (sc == NULL)
310 return 0;
311
312 if ((STF2IFP(sc)->if_flags & IFF_UP) == 0)
313 return 0;
314
315 /* IFF_LINK0 means "no decapsulation" */
316 if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0)
317 return 0;
318
319 if (proto != IPPROTO_IPV6)
320 return 0;
321
322 /* LINTED const cast */
323 m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip);
324
325 if (ip.ip_v != 4)
326 return 0;
327
328 ia6 = stf_getsrcifa6(STF2IFP(sc));
329 if (ia6 == NULL)
330 return 0;
331
332 /*
333 * check if IPv4 dst matches the IPv4 address derived from the
334 * local 6to4 address.
335 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:...
336 */
337 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst,
338 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(&ia6->ia_addr.sin6_addr), &a, sizeof(a));
349 bcopy(GET_V4(&ia6->ia_prefixmask.sin6_addr), &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 struct in6_ifaddr *
361stf_getsrcifa6(ifp)
362 struct ifnet *ifp;
363{
364 struct ifaddr *ia;
365 struct in_ifaddr *ia4;
366 struct sockaddr_in6 *sin6;
367 struct in_addr in;
368
369 TAILQ_FOREACH(ia, &ifp->if_addrlist, ifa_list) {
370 if (ia->ifa_addr->sa_family != AF_INET6)
371 continue;
372 sin6 = (struct sockaddr_in6 *)ia->ifa_addr;
373 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr))
374 continue;
375
376 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in));
377 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash)
378 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr)
379 break;
380 if (ia4 == NULL)
381 continue;
382
383 return (struct in6_ifaddr *)ia;
384 }
385
386 return NULL;
387}
388
389static int
390stf_output(ifp, m, dst, rt)
391 struct ifnet *ifp;
392 struct mbuf *m;
393 struct sockaddr *dst;
394 struct rtentry *rt;
395{
396 struct stf_softc *sc;
397 struct sockaddr_in6 *dst6;
398 struct in_addr in4;
399 caddr_t ptr;
400 struct sockaddr_in *dst4;
401 u_int8_t tos;
402 struct ip *ip;
403 struct ip6_hdr *ip6;
404 struct in6_ifaddr *ia6;
405 u_int32_t af;
406#ifdef MAC
407 int error;
408
409 error = mac_check_ifnet_transmit(ifp, m);
410 if (error) {
411 m_freem(m);
412 return (error);
413 }
414#endif
415
416 sc = ifp->if_softc;
417 dst6 = (struct sockaddr_in6 *)dst;
418
419 /* just in case */
420 if ((ifp->if_flags & IFF_UP) == 0) {
421 m_freem(m);
422 ifp->if_oerrors++;
423 return ENETDOWN;
424 }
425
426 /*
427 * If we don't have an ip4 address that match my inner ip6 address,
428 * we shouldn't generate output. Without this check, we'll end up
429 * using wrong IPv4 source.
430 */
431 ia6 = stf_getsrcifa6(ifp);
432 if (ia6 == NULL) {
433 m_freem(m);
434 ifp->if_oerrors++;
435 return ENETDOWN;
436 }
437
438 if (m->m_len < sizeof(*ip6)) {
439 m = m_pullup(m, sizeof(*ip6));
440 if (!m) {
441 ifp->if_oerrors++;
442 return ENOBUFS;
443 }
444 }
445 ip6 = mtod(m, struct ip6_hdr *);
446 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
447
448 /*
449 * BPF writes need to be handled specially.
450 * This is a null operation, nothing here checks dst->sa_family.
451 */
452 if (dst->sa_family == AF_UNSPEC) {
453 bcopy(dst->sa_data, &af, sizeof(af));
454 dst->sa_family = af;
455 }
456
457 /*
458 * Pickup the right outer dst addr from the list of candidates.
459 * ip6_dst has priority as it may be able to give us shorter IPv4 hops.
460 */
461 ptr = NULL;
462 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst))
463 ptr = GET_V4(&ip6->ip6_dst);
464 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr))
465 ptr = GET_V4(&dst6->sin6_addr);
466 else {
467 m_freem(m);
468 ifp->if_oerrors++;
469 return ENETUNREACH;
470 }
471 bcopy(ptr, &in4, sizeof(in4));
472
473 if (bpf_peers_present(ifp->if_bpf)) {
474 /*
475 * We need to prepend the address family as
476 * a four byte field. Cons up a dummy header
477 * to pacify bpf. This is safe because bpf
478 * will only read from the mbuf (i.e., it won't
479 * try to free it or keep a pointer a to it).
480 */
481 af = AF_INET6;
482 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
483 }
484
485 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
486 if (m && m->m_len < sizeof(struct ip))
487 m = m_pullup(m, sizeof(struct ip));
488 if (m == NULL) {
489 ifp->if_oerrors++;
490 return ENOBUFS;
491 }
492 ip = mtod(m, struct ip *);
493
494 bzero(ip, sizeof(*ip));
495
496 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr),
497 &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 = m->m_pkthdr.len; /*host order*/
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 /*
508 * XXXRW: Locking of sc_ro required.
509 */
510 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst;
511 if (dst4->sin_family != AF_INET ||
512 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) {
513 /* cache route doesn't match */
514 dst4->sin_family = AF_INET;
515 dst4->sin_len = sizeof(struct sockaddr_in);
516 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr));
517 if (sc->sc_ro.ro_rt) {
518 RTFREE(sc->sc_ro.ro_rt);
519 sc->sc_ro.ro_rt = NULL;
520 }
521 }
522
523 if (sc->sc_ro.ro_rt == NULL) {
524 rtalloc(&sc->sc_ro);
525 if (sc->sc_ro.ro_rt == NULL) {
526 m_freem(m);
527 ifp->if_oerrors++;
528 return ENETUNREACH;
529 }
530 }
531
532 ifp->if_opackets++;
533 return ip_output(m, NULL, &sc->sc_ro, 0, NULL, NULL);
534}
535
536static int
537isrfc1918addr(in)
538 struct in_addr *in;
539{
540 /*
541 * returns 1 if private address range:
542 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16
543 */
544 if ((ntohl(in->s_addr) & 0xff000000) >> 24 == 10 ||
545 (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 ||
546 (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168)
547 return 1;
548
549 return 0;
550}
551
552static int
553stf_checkaddr4(sc, in, inifp)
554 struct stf_softc *sc;
555 struct in_addr *in;
556 struct ifnet *inifp; /* incoming interface */
557{
558 struct in_ifaddr *ia4;
559
560 /*
561 * reject packets with the following address:
562 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8
563 */
564 if (IN_MULTICAST(ntohl(in->s_addr)))
565 return -1;
566 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) {
567 case 0: case 127: case 255:
568 return -1;
569 }
570
571 /*
572 * reject packets with private address range.
573 * (requirement from RFC3056 section 2 1st paragraph)
574 */
575 if (isrfc1918addr(in))
576 return -1;
577
578 /*
579 * reject packets with broadcast
580 */
581 for (ia4 = TAILQ_FIRST(&in_ifaddrhead);
582 ia4;
583 ia4 = TAILQ_NEXT(ia4, ia_link))
584 {
585 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
586 continue;
587 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr)
588 return -1;
589 }
590
591 /*
592 * perform ingress filter
593 */
594 if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) {
595 struct sockaddr_in sin;
596 struct rtentry *rt;
597
598 bzero(&sin, sizeof(sin));
599 sin.sin_family = AF_INET;
600 sin.sin_len = sizeof(struct sockaddr_in);
601 sin.sin_addr = *in;
602 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
603 if (!rt || rt->rt_ifp != inifp) {
604#if 0
605 log(LOG_WARNING, "%s: packet from 0x%x dropped "
606 "due to ingress filter\n", if_name(STF2IFP(sc)),
607 (u_int32_t)ntohl(sin.sin_addr.s_addr));
608#endif
609 if (rt)
| 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 "opt_inet.h"
78#include "opt_inet6.h"
79#include "opt_mac.h"
80
81#include <sys/param.h>
82#include <sys/systm.h>
83#include <sys/socket.h>
84#include <sys/sockio.h>
85#include <sys/mbuf.h>
86#include <sys/errno.h>
87#include <sys/kernel.h>
88#include <sys/module.h>
89#include <sys/protosw.h>
90#include <sys/queue.h>
91#include <machine/cpu.h>
92
93#include <sys/malloc.h>
94
95#include <net/if.h>
96#include <net/if_clone.h>
97#include <net/route.h>
98#include <net/netisr.h>
99#include <net/if_types.h>
100#include <net/if_stf.h>
101
102#include <netinet/in.h>
103#include <netinet/in_systm.h>
104#include <netinet/ip.h>
105#include <netinet/ip_var.h>
106#include <netinet/in_var.h>
107
108#include <netinet/ip6.h>
109#include <netinet6/ip6_var.h>
110#include <netinet6/in6_var.h>
111#include <netinet/ip_ecn.h>
112
113#include <netinet/ip_encap.h>
114
115#include <machine/stdarg.h>
116
117#include <net/bpf.h>
118
119#include <security/mac/mac_framework.h>
120
121#define STFNAME "stf"
122#define STFUNIT 0
123
124#define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002)
125
126/*
127 * XXX: Return a pointer with 16-bit aligned. Don't cast it to
128 * struct in_addr *; use bcopy() instead.
129 */
130#define GET_V4(x) ((caddr_t)(&(x)->s6_addr16[1]))
131
132struct stf_softc {
133 struct ifnet *sc_ifp;
134 union {
135 struct route __sc_ro4;
136 struct route_in6 __sc_ro6; /* just for safety */
137 } __sc_ro46;
138#define sc_ro __sc_ro46.__sc_ro4
139 const struct encaptab *encap_cookie;
140};
141#define STF2IFP(sc) ((sc)->sc_ifp)
142
143/*
144 * XXXRW: Note that mutable fields in the softc are not currently locked:
145 * in particular, sc_ro needs to be protected from concurrent entrance
146 * of stf_output().
147 */
148static MALLOC_DEFINE(M_STF, STFNAME, "6to4 Tunnel Interface");
149static const int ip_stf_ttl = 40;
150
151extern struct domain inetdomain;
152struct protosw in_stf_protosw = {
153 .pr_type = SOCK_RAW,
154 .pr_domain = &inetdomain,
155 .pr_protocol = IPPROTO_IPV6,
156 .pr_flags = PR_ATOMIC|PR_ADDR,
157 .pr_input = in_stf_input,
158 .pr_output = (pr_output_t *)rip_output,
159 .pr_ctloutput = rip_ctloutput,
160 .pr_usrreqs = &rip_usrreqs
161};
162
163static char *stfnames[] = {"stf0", "stf", "6to4", NULL};
164
165static int stfmodevent(module_t, int, void *);
166static int stf_encapcheck(const struct mbuf *, int, int, void *);
167static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *);
168static int stf_output(struct ifnet *, struct mbuf *, struct sockaddr *,
169 struct rtentry *);
170static int isrfc1918addr(struct in_addr *);
171static int stf_checkaddr4(struct stf_softc *, struct in_addr *,
172 struct ifnet *);
173static int stf_checkaddr6(struct stf_softc *, struct in6_addr *,
174 struct ifnet *);
175static void stf_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
176static int stf_ioctl(struct ifnet *, u_long, caddr_t);
177
178static int stf_clone_match(struct if_clone *, const char *);
179static int stf_clone_create(struct if_clone *, char *, size_t, caddr_t);
180static int stf_clone_destroy(struct if_clone *, struct ifnet *);
181struct if_clone stf_cloner = IFC_CLONE_INITIALIZER(STFNAME, NULL, 0,
182 NULL, stf_clone_match, stf_clone_create, stf_clone_destroy);
183
184static int
185stf_clone_match(struct if_clone *ifc, const char *name)
186{
187 int i;
188
189 for(i = 0; stfnames[i] != NULL; i++) {
190 if (strcmp(stfnames[i], name) == 0)
191 return (1);
192 }
193
194 return (0);
195}
196
197static int
198stf_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
199{
200 int err, unit;
201 struct stf_softc *sc;
202 struct ifnet *ifp;
203
204 /*
205 * We can only have one unit, but since unit allocation is
206 * already locked, we use it to keep from allocating extra
207 * interfaces.
208 */
209 unit = STFUNIT;
210 err = ifc_alloc_unit(ifc, &unit);
211 if (err != 0)
212 return (err);
213
214 sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO);
215 ifp = STF2IFP(sc) = if_alloc(IFT_STF);
216 if (ifp == NULL) {
217 free(sc, M_STF);
218 ifc_free_unit(ifc, unit);
219 return (ENOSPC);
220 }
221 ifp->if_softc = sc;
222
223 /*
224 * Set the name manually rather then using if_initname because
225 * we don't conform to the default naming convention for interfaces.
226 */
227 strlcpy(ifp->if_xname, name, IFNAMSIZ);
228 ifp->if_dname = ifc->ifc_name;
229 ifp->if_dunit = IF_DUNIT_NONE;
230
231 sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6,
232 stf_encapcheck, &in_stf_protosw, sc);
233 if (sc->encap_cookie == NULL) {
234 if_printf(ifp, "attach failed\n");
235 free(sc, M_STF);
236 ifc_free_unit(ifc, unit);
237 return (ENOMEM);
238 }
239
240 ifp->if_mtu = IPV6_MMTU;
241 ifp->if_ioctl = stf_ioctl;
242 ifp->if_output = stf_output;
243 ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
244 if_attach(ifp);
245 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
246 return (0);
247}
248
249static int
250stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
251{
252 struct stf_softc *sc = ifp->if_softc;
253 int err;
254
255 err = encap_detach(sc->encap_cookie);
256 KASSERT(err == 0, ("Unexpected error detaching encap_cookie"));
257 bpfdetach(ifp);
258 if_detach(ifp);
259 if_free(ifp);
260
261 free(sc, M_STF);
262 ifc_free_unit(ifc, STFUNIT);
263
264 return (0);
265}
266
267static int
268stfmodevent(mod, type, data)
269 module_t mod;
270 int type;
271 void *data;
272{
273
274 switch (type) {
275 case MOD_LOAD:
276 if_clone_attach(&stf_cloner);
277 break;
278 case MOD_UNLOAD:
279 if_clone_detach(&stf_cloner);
280 break;
281 default:
282 return (EOPNOTSUPP);
283 }
284
285 return (0);
286}
287
288static moduledata_t stf_mod = {
289 "if_stf",
290 stfmodevent,
291 0
292};
293
294DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
295
296static int
297stf_encapcheck(m, off, proto, arg)
298 const struct mbuf *m;
299 int off;
300 int proto;
301 void *arg;
302{
303 struct ip ip;
304 struct in6_ifaddr *ia6;
305 struct stf_softc *sc;
306 struct in_addr a, b, mask;
307
308 sc = (struct stf_softc *)arg;
309 if (sc == NULL)
310 return 0;
311
312 if ((STF2IFP(sc)->if_flags & IFF_UP) == 0)
313 return 0;
314
315 /* IFF_LINK0 means "no decapsulation" */
316 if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0)
317 return 0;
318
319 if (proto != IPPROTO_IPV6)
320 return 0;
321
322 /* LINTED const cast */
323 m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip);
324
325 if (ip.ip_v != 4)
326 return 0;
327
328 ia6 = stf_getsrcifa6(STF2IFP(sc));
329 if (ia6 == NULL)
330 return 0;
331
332 /*
333 * check if IPv4 dst matches the IPv4 address derived from the
334 * local 6to4 address.
335 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:...
336 */
337 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst,
338 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(&ia6->ia_addr.sin6_addr), &a, sizeof(a));
349 bcopy(GET_V4(&ia6->ia_prefixmask.sin6_addr), &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 struct in6_ifaddr *
361stf_getsrcifa6(ifp)
362 struct ifnet *ifp;
363{
364 struct ifaddr *ia;
365 struct in_ifaddr *ia4;
366 struct sockaddr_in6 *sin6;
367 struct in_addr in;
368
369 TAILQ_FOREACH(ia, &ifp->if_addrlist, ifa_list) {
370 if (ia->ifa_addr->sa_family != AF_INET6)
371 continue;
372 sin6 = (struct sockaddr_in6 *)ia->ifa_addr;
373 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr))
374 continue;
375
376 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in));
377 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash)
378 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr)
379 break;
380 if (ia4 == NULL)
381 continue;
382
383 return (struct in6_ifaddr *)ia;
384 }
385
386 return NULL;
387}
388
389static int
390stf_output(ifp, m, dst, rt)
391 struct ifnet *ifp;
392 struct mbuf *m;
393 struct sockaddr *dst;
394 struct rtentry *rt;
395{
396 struct stf_softc *sc;
397 struct sockaddr_in6 *dst6;
398 struct in_addr in4;
399 caddr_t ptr;
400 struct sockaddr_in *dst4;
401 u_int8_t tos;
402 struct ip *ip;
403 struct ip6_hdr *ip6;
404 struct in6_ifaddr *ia6;
405 u_int32_t af;
406#ifdef MAC
407 int error;
408
409 error = mac_check_ifnet_transmit(ifp, m);
410 if (error) {
411 m_freem(m);
412 return (error);
413 }
414#endif
415
416 sc = ifp->if_softc;
417 dst6 = (struct sockaddr_in6 *)dst;
418
419 /* just in case */
420 if ((ifp->if_flags & IFF_UP) == 0) {
421 m_freem(m);
422 ifp->if_oerrors++;
423 return ENETDOWN;
424 }
425
426 /*
427 * If we don't have an ip4 address that match my inner ip6 address,
428 * we shouldn't generate output. Without this check, we'll end up
429 * using wrong IPv4 source.
430 */
431 ia6 = stf_getsrcifa6(ifp);
432 if (ia6 == NULL) {
433 m_freem(m);
434 ifp->if_oerrors++;
435 return ENETDOWN;
436 }
437
438 if (m->m_len < sizeof(*ip6)) {
439 m = m_pullup(m, sizeof(*ip6));
440 if (!m) {
441 ifp->if_oerrors++;
442 return ENOBUFS;
443 }
444 }
445 ip6 = mtod(m, struct ip6_hdr *);
446 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
447
448 /*
449 * BPF writes need to be handled specially.
450 * This is a null operation, nothing here checks dst->sa_family.
451 */
452 if (dst->sa_family == AF_UNSPEC) {
453 bcopy(dst->sa_data, &af, sizeof(af));
454 dst->sa_family = af;
455 }
456
457 /*
458 * Pickup the right outer dst addr from the list of candidates.
459 * ip6_dst has priority as it may be able to give us shorter IPv4 hops.
460 */
461 ptr = NULL;
462 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst))
463 ptr = GET_V4(&ip6->ip6_dst);
464 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr))
465 ptr = GET_V4(&dst6->sin6_addr);
466 else {
467 m_freem(m);
468 ifp->if_oerrors++;
469 return ENETUNREACH;
470 }
471 bcopy(ptr, &in4, sizeof(in4));
472
473 if (bpf_peers_present(ifp->if_bpf)) {
474 /*
475 * We need to prepend the address family as
476 * a four byte field. Cons up a dummy header
477 * to pacify bpf. This is safe because bpf
478 * will only read from the mbuf (i.e., it won't
479 * try to free it or keep a pointer a to it).
480 */
481 af = AF_INET6;
482 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
483 }
484
485 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
486 if (m && m->m_len < sizeof(struct ip))
487 m = m_pullup(m, sizeof(struct ip));
488 if (m == NULL) {
489 ifp->if_oerrors++;
490 return ENOBUFS;
491 }
492 ip = mtod(m, struct ip *);
493
494 bzero(ip, sizeof(*ip));
495
496 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr),
497 &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 = m->m_pkthdr.len; /*host order*/
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 /*
508 * XXXRW: Locking of sc_ro required.
509 */
510 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst;
511 if (dst4->sin_family != AF_INET ||
512 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) {
513 /* cache route doesn't match */
514 dst4->sin_family = AF_INET;
515 dst4->sin_len = sizeof(struct sockaddr_in);
516 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr));
517 if (sc->sc_ro.ro_rt) {
518 RTFREE(sc->sc_ro.ro_rt);
519 sc->sc_ro.ro_rt = NULL;
520 }
521 }
522
523 if (sc->sc_ro.ro_rt == NULL) {
524 rtalloc(&sc->sc_ro);
525 if (sc->sc_ro.ro_rt == NULL) {
526 m_freem(m);
527 ifp->if_oerrors++;
528 return ENETUNREACH;
529 }
530 }
531
532 ifp->if_opackets++;
533 return ip_output(m, NULL, &sc->sc_ro, 0, NULL, NULL);
534}
535
536static int
537isrfc1918addr(in)
538 struct in_addr *in;
539{
540 /*
541 * returns 1 if private address range:
542 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16
543 */
544 if ((ntohl(in->s_addr) & 0xff000000) >> 24 == 10 ||
545 (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 ||
546 (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168)
547 return 1;
548
549 return 0;
550}
551
552static int
553stf_checkaddr4(sc, in, inifp)
554 struct stf_softc *sc;
555 struct in_addr *in;
556 struct ifnet *inifp; /* incoming interface */
557{
558 struct in_ifaddr *ia4;
559
560 /*
561 * reject packets with the following address:
562 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8
563 */
564 if (IN_MULTICAST(ntohl(in->s_addr)))
565 return -1;
566 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) {
567 case 0: case 127: case 255:
568 return -1;
569 }
570
571 /*
572 * reject packets with private address range.
573 * (requirement from RFC3056 section 2 1st paragraph)
574 */
575 if (isrfc1918addr(in))
576 return -1;
577
578 /*
579 * reject packets with broadcast
580 */
581 for (ia4 = TAILQ_FIRST(&in_ifaddrhead);
582 ia4;
583 ia4 = TAILQ_NEXT(ia4, ia_link))
584 {
585 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
586 continue;
587 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr)
588 return -1;
589 }
590
591 /*
592 * perform ingress filter
593 */
594 if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) {
595 struct sockaddr_in sin;
596 struct rtentry *rt;
597
598 bzero(&sin, sizeof(sin));
599 sin.sin_family = AF_INET;
600 sin.sin_len = sizeof(struct sockaddr_in);
601 sin.sin_addr = *in;
602 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
603 if (!rt || rt->rt_ifp != inifp) {
604#if 0
605 log(LOG_WARNING, "%s: packet from 0x%x dropped "
606 "due to ingress filter\n", if_name(STF2IFP(sc)),
607 (u_int32_t)ntohl(sin.sin_addr.s_addr));
608#endif
609 if (rt)
|
614 }
615
616 return 0;
617}
618
619static int
620stf_checkaddr6(sc, in6, inifp)
621 struct stf_softc *sc;
622 struct in6_addr *in6;
623 struct ifnet *inifp; /* incoming interface */
624{
625 /*
626 * check 6to4 addresses
627 */
628 if (IN6_IS_ADDR_6TO4(in6)) {
629 struct in_addr in4;
630 bcopy(GET_V4(in6), &in4, sizeof(in4));
631 return stf_checkaddr4(sc, &in4, inifp);
632 }
633
634 /*
635 * reject anything that look suspicious. the test is implemented
636 * in ip6_input too, but we check here as well to
637 * (1) reject bad packets earlier, and
638 * (2) to be safe against future ip6_input change.
639 */
640 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6))
641 return -1;
642
643 return 0;
644}
645
646void
647in_stf_input(m, off)
648 struct mbuf *m;
649 int off;
650{
651 int proto;
652 struct stf_softc *sc;
653 struct ip *ip;
654 struct ip6_hdr *ip6;
655 u_int8_t otos, itos;
656 struct ifnet *ifp;
657
658 proto = mtod(m, struct ip *)->ip_p;
659
660 if (proto != IPPROTO_IPV6) {
661 m_freem(m);
662 return;
663 }
664
665 ip = mtod(m, struct ip *);
666
667 sc = (struct stf_softc *)encap_getarg(m);
668
669 if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) {
670 m_freem(m);
671 return;
672 }
673
674 ifp = STF2IFP(sc);
675
676#ifdef MAC
677 mac_create_mbuf_from_ifnet(ifp, m);
678#endif
679
680 /*
681 * perform sanity check against outer src/dst.
682 * for source, perform ingress filter as well.
683 */
684 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 ||
685 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) {
686 m_freem(m);
687 return;
688 }
689
690 otos = ip->ip_tos;
691 m_adj(m, off);
692
693 if (m->m_len < sizeof(*ip6)) {
694 m = m_pullup(m, sizeof(*ip6));
695 if (!m)
696 return;
697 }
698 ip6 = mtod(m, struct ip6_hdr *);
699
700 /*
701 * perform sanity check against inner src/dst.
702 * for source, perform ingress filter as well.
703 */
704 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 ||
705 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) {
706 m_freem(m);
707 return;
708 }
709
710 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
711 if ((ifp->if_flags & IFF_LINK1) != 0)
712 ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
713 else
714 ip_ecn_egress(ECN_NOCARE, &otos, &itos);
715 ip6->ip6_flow &= ~htonl(0xff << 20);
716 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
717
718 m->m_pkthdr.rcvif = ifp;
719
720 if (bpf_peers_present(ifp->if_bpf)) {
721 /*
722 * We need to prepend the address family as
723 * a four byte field. Cons up a dummy header
724 * to pacify bpf. This is safe because bpf
725 * will only read from the mbuf (i.e., it won't
726 * try to free it or keep a pointer a to it).
727 */
728 u_int32_t af = AF_INET6;
729 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
730 }
731
732 /*
733 * Put the packet to the network layer input queue according to the
734 * specified address family.
735 * See net/if_gif.c for possible issues with packet processing
736 * reorder due to extra queueing.
737 */
738 ifp->if_ipackets++;
739 ifp->if_ibytes += m->m_pkthdr.len;
740 netisr_dispatch(NETISR_IPV6, m);
741}
742
743/* ARGSUSED */
744static void
745stf_rtrequest(cmd, rt, info)
746 int cmd;
747 struct rtentry *rt;
748 struct rt_addrinfo *info;
749{
750 RT_LOCK_ASSERT(rt);
751 rt->rt_rmx.rmx_mtu = IPV6_MMTU;
752}
753
754static int
755stf_ioctl(ifp, cmd, data)
756 struct ifnet *ifp;
757 u_long cmd;
758 caddr_t data;
759{
760 struct ifaddr *ifa;
761 struct ifreq *ifr;
762 struct sockaddr_in6 *sin6;
763 struct in_addr addr;
764 int error;
765
766 error = 0;
767 switch (cmd) {
768 case SIOCSIFADDR:
769 ifa = (struct ifaddr *)data;
770 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) {
771 error = EAFNOSUPPORT;
772 break;
773 }
774 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
775 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) {
776 error = EINVAL;
777 break;
778 }
779 bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr));
780 if (isrfc1918addr(&addr)) {
781 error = EINVAL;
782 break;
783 }
784
785 ifa->ifa_rtrequest = stf_rtrequest;
786 ifp->if_flags |= IFF_UP;
787 break;
788
789 case SIOCADDMULTI:
790 case SIOCDELMULTI:
791 ifr = (struct ifreq *)data;
792 if (ifr && ifr->ifr_addr.sa_family == AF_INET6)
793 ;
794 else
795 error = EAFNOSUPPORT;
796 break;
797
798 default:
799 error = EINVAL;
800 break;
801 }
802
803 return error;
804}
| 614 }
615
616 return 0;
617}
618
619static int
620stf_checkaddr6(sc, in6, inifp)
621 struct stf_softc *sc;
622 struct in6_addr *in6;
623 struct ifnet *inifp; /* incoming interface */
624{
625 /*
626 * check 6to4 addresses
627 */
628 if (IN6_IS_ADDR_6TO4(in6)) {
629 struct in_addr in4;
630 bcopy(GET_V4(in6), &in4, sizeof(in4));
631 return stf_checkaddr4(sc, &in4, inifp);
632 }
633
634 /*
635 * reject anything that look suspicious. the test is implemented
636 * in ip6_input too, but we check here as well to
637 * (1) reject bad packets earlier, and
638 * (2) to be safe against future ip6_input change.
639 */
640 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6))
641 return -1;
642
643 return 0;
644}
645
646void
647in_stf_input(m, off)
648 struct mbuf *m;
649 int off;
650{
651 int proto;
652 struct stf_softc *sc;
653 struct ip *ip;
654 struct ip6_hdr *ip6;
655 u_int8_t otos, itos;
656 struct ifnet *ifp;
657
658 proto = mtod(m, struct ip *)->ip_p;
659
660 if (proto != IPPROTO_IPV6) {
661 m_freem(m);
662 return;
663 }
664
665 ip = mtod(m, struct ip *);
666
667 sc = (struct stf_softc *)encap_getarg(m);
668
669 if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) {
670 m_freem(m);
671 return;
672 }
673
674 ifp = STF2IFP(sc);
675
676#ifdef MAC
677 mac_create_mbuf_from_ifnet(ifp, m);
678#endif
679
680 /*
681 * perform sanity check against outer src/dst.
682 * for source, perform ingress filter as well.
683 */
684 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 ||
685 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) {
686 m_freem(m);
687 return;
688 }
689
690 otos = ip->ip_tos;
691 m_adj(m, off);
692
693 if (m->m_len < sizeof(*ip6)) {
694 m = m_pullup(m, sizeof(*ip6));
695 if (!m)
696 return;
697 }
698 ip6 = mtod(m, struct ip6_hdr *);
699
700 /*
701 * perform sanity check against inner src/dst.
702 * for source, perform ingress filter as well.
703 */
704 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 ||
705 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) {
706 m_freem(m);
707 return;
708 }
709
710 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
711 if ((ifp->if_flags & IFF_LINK1) != 0)
712 ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
713 else
714 ip_ecn_egress(ECN_NOCARE, &otos, &itos);
715 ip6->ip6_flow &= ~htonl(0xff << 20);
716 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
717
718 m->m_pkthdr.rcvif = ifp;
719
720 if (bpf_peers_present(ifp->if_bpf)) {
721 /*
722 * We need to prepend the address family as
723 * a four byte field. Cons up a dummy header
724 * to pacify bpf. This is safe because bpf
725 * will only read from the mbuf (i.e., it won't
726 * try to free it or keep a pointer a to it).
727 */
728 u_int32_t af = AF_INET6;
729 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
730 }
731
732 /*
733 * Put the packet to the network layer input queue according to the
734 * specified address family.
735 * See net/if_gif.c for possible issues with packet processing
736 * reorder due to extra queueing.
737 */
738 ifp->if_ipackets++;
739 ifp->if_ibytes += m->m_pkthdr.len;
740 netisr_dispatch(NETISR_IPV6, m);
741}
742
743/* ARGSUSED */
744static void
745stf_rtrequest(cmd, rt, info)
746 int cmd;
747 struct rtentry *rt;
748 struct rt_addrinfo *info;
749{
750 RT_LOCK_ASSERT(rt);
751 rt->rt_rmx.rmx_mtu = IPV6_MMTU;
752}
753
754static int
755stf_ioctl(ifp, cmd, data)
756 struct ifnet *ifp;
757 u_long cmd;
758 caddr_t data;
759{
760 struct ifaddr *ifa;
761 struct ifreq *ifr;
762 struct sockaddr_in6 *sin6;
763 struct in_addr addr;
764 int error;
765
766 error = 0;
767 switch (cmd) {
768 case SIOCSIFADDR:
769 ifa = (struct ifaddr *)data;
770 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) {
771 error = EAFNOSUPPORT;
772 break;
773 }
774 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
775 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) {
776 error = EINVAL;
777 break;
778 }
779 bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr));
780 if (isrfc1918addr(&addr)) {
781 error = EINVAL;
782 break;
783 }
784
785 ifa->ifa_rtrequest = stf_rtrequest;
786 ifp->if_flags |= IFF_UP;
787 break;
788
789 case SIOCADDMULTI:
790 case SIOCDELMULTI:
791 ifr = (struct ifreq *)data;
792 if (ifr && ifr->ifr_addr.sa_family == AF_INET6)
793 ;
794 else
795 error = EAFNOSUPPORT;
796 break;
797
798 default:
799 error = EINVAL;
800 break;
801 }
802
803 return error;
804}
|