FreeBSD/Linux Kernel Cross Reference
sys/net/if_stf.c
1 /* $FreeBSD: releng/5.3/sys/net/if_stf.c 136588 2004-10-16 08:43:07Z cvs2svn $ */
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/mac.h>
86 #include <sys/mbuf.h>
87 #include <sys/errno.h>
88 #include <sys/kernel.h>
89 #include <sys/module.h>
90 #include <sys/protosw.h>
91 #include <sys/queue.h>
92 #include <machine/cpu.h>
93
94 #include <sys/malloc.h>
95
96 #include <net/if.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/if_stf.h>
102
103 #include <netinet/in.h>
104 #include <netinet/in_systm.h>
105 #include <netinet/ip.h>
106 #include <netinet/ip_var.h>
107 #include <netinet/in_var.h>
108
109 #include <netinet/ip6.h>
110 #include <netinet6/ip6_var.h>
111 #include <netinet6/in6_var.h>
112 #include <netinet/ip_ecn.h>
113
114 #include <netinet/ip_encap.h>
115
116 #include <machine/stdarg.h>
117
118 #include <net/net_osdep.h>
119
120 #include <net/bpf.h>
121
122 #define STFNAME "stf"
123 #define STFUNIT 0
124
125 #define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002)
126
127 /*
128 * XXX: Return a pointer with 16-bit aligned. Don't cast it to
129 * struct in_addr *; use bcopy() instead.
130 */
131 #define GET_V4(x) ((caddr_t)(&(x)->s6_addr16[1]))
132
133 struct stf_softc {
134 struct ifnet sc_if; /* common area */
135 union {
136 struct route __sc_ro4;
137 struct route_in6 __sc_ro6; /* just for safety */
138 } __sc_ro46;
139 #define sc_ro __sc_ro46.__sc_ro4
140 const struct encaptab *encap_cookie;
141 LIST_ENTRY(stf_softc) sc_list; /* all stf's are linked */
142 };
143
144 /*
145 * All mutable global variables in if_stf.c are protected by stf_mtx.
146 * XXXRW: Note that mutable fields in the softc are not currently locked:
147 * in particular, sc_ro needs to be protected from concurrent entrance
148 * of stf_output().
149 */
150 static struct mtx stf_mtx;
151 static LIST_HEAD(, stf_softc) stf_softc_list;
152
153 static MALLOC_DEFINE(M_STF, STFNAME, "6to4 Tunnel Interface");
154 static const int ip_stf_ttl = 40;
155
156 extern struct domain inetdomain;
157 struct protosw in_stf_protosw =
158 { SOCK_RAW, &inetdomain, IPPROTO_IPV6, PR_ATOMIC|PR_ADDR,
159 in_stf_input, (pr_output_t*)rip_output, 0, rip_ctloutput,
160 0,
161 0, 0, 0, 0,
162 &rip_usrreqs
163 };
164
165 static char *stfnames[] = {"stf0", "stf", "6to4", NULL};
166
167 static int stfmodevent(module_t, int, void *);
168 static int stf_encapcheck(const struct mbuf *, int, int, void *);
169 static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *);
170 static int stf_output(struct ifnet *, struct mbuf *, struct sockaddr *,
171 struct rtentry *);
172 static int isrfc1918addr(struct in_addr *);
173 static int stf_checkaddr4(struct stf_softc *, struct in_addr *,
174 struct ifnet *);
175 static int stf_checkaddr6(struct stf_softc *, struct in6_addr *,
176 struct ifnet *);
177 static void stf_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
178 static int stf_ioctl(struct ifnet *, u_long, caddr_t);
179
180 static int stf_clone_match(struct if_clone *, const char *);
181 static int stf_clone_create(struct if_clone *, char *, size_t);
182 static int stf_clone_destroy(struct if_clone *, struct ifnet *);
183 struct if_clone stf_cloner = IFC_CLONE_INITIALIZER(STFNAME, NULL, 0,
184 NULL, stf_clone_match, stf_clone_create, stf_clone_destroy);
185
186 static int
187 stf_clone_match(struct if_clone *ifc, const char *name)
188 {
189 int i;
190
191 for(i = 0; stfnames[i] != NULL; i++) {
192 if (strcmp(stfnames[i], name) == 0)
193 return (1);
194 }
195
196 return (0);
197 }
198
199 static int
200 stf_clone_create(struct if_clone *ifc, char *name, size_t len)
201 {
202 int err, unit;
203 struct stf_softc *sc;
204 struct ifnet *ifp;
205
206 /*
207 * We can only have one unit, but since unit allocation is
208 * already locked, we use it to keep from allocating extra
209 * interfaces.
210 */
211 unit = STFUNIT;
212 err = ifc_alloc_unit(ifc, &unit);
213 if (err != 0)
214 return (err);
215
216 sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO);
217 ifp = &sc->sc_if;
218 /*
219 * Set the name manually rather then using if_initname because
220 * we don't conform to the default naming convention for interfaces.
221 */
222 strlcpy(ifp->if_xname, name, IFNAMSIZ);
223 ifp->if_dname = ifc->ifc_name;
224 ifp->if_dunit = IF_DUNIT_NONE;
225
226 sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6,
227 stf_encapcheck, &in_stf_protosw, sc);
228 if (sc->encap_cookie == NULL) {
229 if_printf(ifp, "attach failed\n");
230 free(sc, M_STF);
231 ifc_free_unit(ifc, unit);
232 return (ENOMEM);
233 }
234
235 ifp->if_mtu = IPV6_MMTU;
236 ifp->if_ioctl = stf_ioctl;
237 ifp->if_output = stf_output;
238 ifp->if_type = IFT_STF;
239 ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
240 if_attach(ifp);
241 bpfattach(ifp, DLT_NULL, sizeof(u_int));
242 mtx_lock(&stf_mtx);
243 LIST_INSERT_HEAD(&stf_softc_list, sc, sc_list);
244 mtx_unlock(&stf_mtx);
245 return (0);
246 }
247
248 static void
249 stf_destroy(struct stf_softc *sc)
250 {
251 int err;
252
253 err = encap_detach(sc->encap_cookie);
254 KASSERT(err == 0, ("Unexpected error detaching encap_cookie"));
255 bpfdetach(&sc->sc_if);
256 if_detach(&sc->sc_if);
257
258 free(sc, M_STF);
259 }
260
261 static int
262 stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
263 {
264 struct stf_softc *sc = (void *) ifp;
265
266 mtx_lock(&stf_mtx);
267 LIST_REMOVE(sc, sc_list);
268 mtx_unlock(&stf_mtx);
269
270 stf_destroy(sc);
271 ifc_free_unit(ifc, STFUNIT);
272
273 return (0);
274 }
275
276 static int
277 stfmodevent(mod, type, data)
278 module_t mod;
279 int type;
280 void *data;
281 {
282 struct stf_softc *sc;
283
284 switch (type) {
285 case MOD_LOAD:
286 mtx_init(&stf_mtx, "stf_mtx", NULL, MTX_DEF);
287 LIST_INIT(&stf_softc_list);
288 if_clone_attach(&stf_cloner);
289
290 break;
291 case MOD_UNLOAD:
292 if_clone_detach(&stf_cloner);
293
294 mtx_lock(&stf_mtx);
295 while ((sc = LIST_FIRST(&stf_softc_list)) != NULL) {
296 LIST_REMOVE(sc, sc_list);
297 mtx_unlock(&stf_mtx);
298 stf_destroy(sc);
299 mtx_lock(&stf_mtx);
300 }
301 mtx_unlock(&stf_mtx);
302 mtx_destroy(&stf_mtx);
303 break;
304 default:
305 return (EOPNOTSUPP);
306 }
307
308 return (0);
309 }
310
311 static moduledata_t stf_mod = {
312 "if_stf",
313 stfmodevent,
314 0
315 };
316
317 DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
318
319 static int
320 stf_encapcheck(m, off, proto, arg)
321 const struct mbuf *m;
322 int off;
323 int proto;
324 void *arg;
325 {
326 struct ip ip;
327 struct in6_ifaddr *ia6;
328 struct stf_softc *sc;
329 struct in_addr a, b, mask;
330
331 sc = (struct stf_softc *)arg;
332 if (sc == NULL)
333 return 0;
334
335 if ((sc->sc_if.if_flags & IFF_UP) == 0)
336 return 0;
337
338 /* IFF_LINK0 means "no decapsulation" */
339 if ((sc->sc_if.if_flags & IFF_LINK0) != 0)
340 return 0;
341
342 if (proto != IPPROTO_IPV6)
343 return 0;
344
345 /* LINTED const cast */
346 m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip);
347
348 if (ip.ip_v != 4)
349 return 0;
350
351 ia6 = stf_getsrcifa6(&sc->sc_if);
352 if (ia6 == NULL)
353 return 0;
354
355 /*
356 * check if IPv4 dst matches the IPv4 address derived from the
357 * local 6to4 address.
358 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:...
359 */
360 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst,
361 sizeof(ip.ip_dst)) != 0)
362 return 0;
363
364 /*
365 * check if IPv4 src matches the IPv4 address derived from the
366 * local 6to4 address masked by prefixmask.
367 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24
368 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24
369 */
370 bzero(&a, sizeof(a));
371 bcopy(GET_V4(&ia6->ia_addr.sin6_addr), &a, sizeof(a));
372 bcopy(GET_V4(&ia6->ia_prefixmask.sin6_addr), &mask, sizeof(mask));
373 a.s_addr &= mask.s_addr;
374 b = ip.ip_src;
375 b.s_addr &= mask.s_addr;
376 if (a.s_addr != b.s_addr)
377 return 0;
378
379 /* stf interface makes single side match only */
380 return 32;
381 }
382
383 static struct in6_ifaddr *
384 stf_getsrcifa6(ifp)
385 struct ifnet *ifp;
386 {
387 struct ifaddr *ia;
388 struct in_ifaddr *ia4;
389 struct sockaddr_in6 *sin6;
390 struct in_addr in;
391
392 for (ia = TAILQ_FIRST(&ifp->if_addrlist);
393 ia;
394 ia = TAILQ_NEXT(ia, ifa_list))
395 {
396 if (ia->ifa_addr == NULL)
397 continue;
398 if (ia->ifa_addr->sa_family != AF_INET6)
399 continue;
400 sin6 = (struct sockaddr_in6 *)ia->ifa_addr;
401 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr))
402 continue;
403
404 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in));
405 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash)
406 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr)
407 break;
408 if (ia4 == NULL)
409 continue;
410
411 return (struct in6_ifaddr *)ia;
412 }
413
414 return NULL;
415 }
416
417 static int
418 stf_output(ifp, m, dst, rt)
419 struct ifnet *ifp;
420 struct mbuf *m;
421 struct sockaddr *dst;
422 struct rtentry *rt;
423 {
424 struct stf_softc *sc;
425 struct sockaddr_in6 *dst6;
426 struct in_addr in4;
427 caddr_t ptr;
428 struct sockaddr_in *dst4;
429 u_int8_t tos;
430 struct ip *ip;
431 struct ip6_hdr *ip6;
432 struct in6_ifaddr *ia6;
433 #ifdef MAC
434 int error;
435
436 error = mac_check_ifnet_transmit(ifp, m);
437 if (error) {
438 m_freem(m);
439 return (error);
440 }
441 #endif
442
443 sc = (struct stf_softc*)ifp;
444 dst6 = (struct sockaddr_in6 *)dst;
445
446 /* just in case */
447 if ((ifp->if_flags & IFF_UP) == 0) {
448 m_freem(m);
449 ifp->if_oerrors++;
450 return ENETDOWN;
451 }
452
453 /*
454 * If we don't have an ip4 address that match my inner ip6 address,
455 * we shouldn't generate output. Without this check, we'll end up
456 * using wrong IPv4 source.
457 */
458 ia6 = stf_getsrcifa6(ifp);
459 if (ia6 == NULL) {
460 m_freem(m);
461 ifp->if_oerrors++;
462 return ENETDOWN;
463 }
464
465 if (m->m_len < sizeof(*ip6)) {
466 m = m_pullup(m, sizeof(*ip6));
467 if (!m) {
468 ifp->if_oerrors++;
469 return ENOBUFS;
470 }
471 }
472 ip6 = mtod(m, struct ip6_hdr *);
473 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
474
475 /*
476 * Pickup the right outer dst addr from the list of candidates.
477 * ip6_dst has priority as it may be able to give us shorter IPv4 hops.
478 */
479 ptr = NULL;
480 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst))
481 ptr = GET_V4(&ip6->ip6_dst);
482 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr))
483 ptr = GET_V4(&dst6->sin6_addr);
484 else {
485 m_freem(m);
486 ifp->if_oerrors++;
487 return ENETUNREACH;
488 }
489 bcopy(ptr, &in4, sizeof(in4));
490
491 #if NBPFILTER > 0
492 if (ifp->if_bpf) {
493 /*
494 * We need to prepend the address family as
495 * a four byte field. Cons up a dummy header
496 * to pacify bpf. This is safe because bpf
497 * will only read from the mbuf (i.e., it won't
498 * try to free it or keep a pointer a to it).
499 */
500 u_int32_t af = AF_INET6;
501 #ifdef HAVE_OLD_BPF
502 struct mbuf m0;
503
504 m0.m_next = m;
505 m0.m_len = 4;
506 m0.m_data = (char *)⁡
507
508 BPF_MTAP(ifp, &m0);
509 #else
510 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
511 #endif
512 }
513 #endif /*NBPFILTER > 0*/
514
515 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
516 if (m && m->m_len < sizeof(struct ip))
517 m = m_pullup(m, sizeof(struct ip));
518 if (m == NULL) {
519 ifp->if_oerrors++;
520 return ENOBUFS;
521 }
522 ip = mtod(m, struct ip *);
523
524 bzero(ip, sizeof(*ip));
525
526 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr),
527 &ip->ip_src, sizeof(ip->ip_src));
528 bcopy(&in4, &ip->ip_dst, sizeof(ip->ip_dst));
529 ip->ip_p = IPPROTO_IPV6;
530 ip->ip_ttl = ip_stf_ttl;
531 ip->ip_len = m->m_pkthdr.len; /*host order*/
532 if (ifp->if_flags & IFF_LINK1)
533 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos);
534 else
535 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos);
536
537 /*
538 * XXXRW: Locking of sc_ro required.
539 */
540 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst;
541 if (dst4->sin_family != AF_INET ||
542 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) {
543 /* cache route doesn't match */
544 dst4->sin_family = AF_INET;
545 dst4->sin_len = sizeof(struct sockaddr_in);
546 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr));
547 if (sc->sc_ro.ro_rt) {
548 RTFREE(sc->sc_ro.ro_rt);
549 sc->sc_ro.ro_rt = NULL;
550 }
551 }
552
553 if (sc->sc_ro.ro_rt == NULL) {
554 rtalloc(&sc->sc_ro);
555 if (sc->sc_ro.ro_rt == NULL) {
556 m_freem(m);
557 ifp->if_oerrors++;
558 return ENETUNREACH;
559 }
560 }
561
562 ifp->if_opackets++;
563 return ip_output(m, NULL, &sc->sc_ro, 0, NULL, NULL);
564 }
565
566 static int
567 isrfc1918addr(in)
568 struct in_addr *in;
569 {
570 /*
571 * returns 1 if private address range:
572 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16
573 */
574 if ((ntohl(in->s_addr) & 0xff000000) >> 24 == 10 ||
575 (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 ||
576 (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168)
577 return 1;
578
579 return 0;
580 }
581
582 static int
583 stf_checkaddr4(sc, in, inifp)
584 struct stf_softc *sc;
585 struct in_addr *in;
586 struct ifnet *inifp; /* incoming interface */
587 {
588 struct in_ifaddr *ia4;
589
590 /*
591 * reject packets with the following address:
592 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8
593 */
594 if (IN_MULTICAST(ntohl(in->s_addr)))
595 return -1;
596 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) {
597 case 0: case 127: case 255:
598 return -1;
599 }
600
601 /*
602 * reject packets with private address range.
603 * (requirement from RFC3056 section 2 1st paragraph)
604 */
605 if (isrfc1918addr(in))
606 return -1;
607
608 /*
609 * reject packets with broadcast
610 */
611 for (ia4 = TAILQ_FIRST(&in_ifaddrhead);
612 ia4;
613 ia4 = TAILQ_NEXT(ia4, ia_link))
614 {
615 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
616 continue;
617 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr)
618 return -1;
619 }
620
621 /*
622 * perform ingress filter
623 */
624 if (sc && (sc->sc_if.if_flags & IFF_LINK2) == 0 && inifp) {
625 struct sockaddr_in sin;
626 struct rtentry *rt;
627
628 bzero(&sin, sizeof(sin));
629 sin.sin_family = AF_INET;
630 sin.sin_len = sizeof(struct sockaddr_in);
631 sin.sin_addr = *in;
632 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
633 if (!rt || rt->rt_ifp != inifp) {
634 #if 0
635 log(LOG_WARNING, "%s: packet from 0x%x dropped "
636 "due to ingress filter\n", if_name(&sc->sc_if),
637 (u_int32_t)ntohl(sin.sin_addr.s_addr));
638 #endif
639 if (rt)
640 rtfree(rt);
641 return -1;
642 }
643 rtfree(rt);
644 }
645
646 return 0;
647 }
648
649 static int
650 stf_checkaddr6(sc, in6, inifp)
651 struct stf_softc *sc;
652 struct in6_addr *in6;
653 struct ifnet *inifp; /* incoming interface */
654 {
655 /*
656 * check 6to4 addresses
657 */
658 if (IN6_IS_ADDR_6TO4(in6)) {
659 struct in_addr in4;
660 bcopy(GET_V4(in6), &in4, sizeof(in4));
661 return stf_checkaddr4(sc, &in4, inifp);
662 }
663
664 /*
665 * reject anything that look suspicious. the test is implemented
666 * in ip6_input too, but we check here as well to
667 * (1) reject bad packets earlier, and
668 * (2) to be safe against future ip6_input change.
669 */
670 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6))
671 return -1;
672
673 return 0;
674 }
675
676 void
677 in_stf_input(m, off)
678 struct mbuf *m;
679 int off;
680 {
681 int proto;
682 struct stf_softc *sc;
683 struct ip *ip;
684 struct ip6_hdr *ip6;
685 u_int8_t otos, itos;
686 struct ifnet *ifp;
687
688 proto = mtod(m, struct ip *)->ip_p;
689
690 if (proto != IPPROTO_IPV6) {
691 m_freem(m);
692 return;
693 }
694
695 ip = mtod(m, struct ip *);
696
697 sc = (struct stf_softc *)encap_getarg(m);
698
699 if (sc == NULL || (sc->sc_if.if_flags & IFF_UP) == 0) {
700 m_freem(m);
701 return;
702 }
703
704 ifp = &sc->sc_if;
705
706 #ifdef MAC
707 mac_create_mbuf_from_ifnet(ifp, m);
708 #endif
709
710 /*
711 * perform sanity check against outer src/dst.
712 * for source, perform ingress filter as well.
713 */
714 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 ||
715 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) {
716 m_freem(m);
717 return;
718 }
719
720 otos = ip->ip_tos;
721 m_adj(m, off);
722
723 if (m->m_len < sizeof(*ip6)) {
724 m = m_pullup(m, sizeof(*ip6));
725 if (!m)
726 return;
727 }
728 ip6 = mtod(m, struct ip6_hdr *);
729
730 /*
731 * perform sanity check against inner src/dst.
732 * for source, perform ingress filter as well.
733 */
734 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 ||
735 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) {
736 m_freem(m);
737 return;
738 }
739
740 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
741 if ((ifp->if_flags & IFF_LINK1) != 0)
742 ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
743 else
744 ip_ecn_egress(ECN_NOCARE, &otos, &itos);
745 ip6->ip6_flow &= ~htonl(0xff << 20);
746 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
747
748 m->m_pkthdr.rcvif = ifp;
749
750 if (ifp->if_bpf) {
751 /*
752 * We need to prepend the address family as
753 * a four byte field. Cons up a dummy header
754 * to pacify bpf. This is safe because bpf
755 * will only read from the mbuf (i.e., it won't
756 * try to free it or keep a pointer a to it).
757 */
758 u_int32_t af = AF_INET6;
759 #ifdef HAVE_OLD_BPF
760 struct mbuf m0;
761
762 m0.m_next = m;
763 m0.m_len = 4;
764 m0.m_data = (char *)⁡
765
766 BPF_MTAP(ifp, &m0);
767 #else
768 bpf_mtap2(ifp->if_bpf, &af, sizeof(ah), m);
769 #endif
770 }
771
772 /*
773 * Put the packet to the network layer input queue according to the
774 * specified address family.
775 * See net/if_gif.c for possible issues with packet processing
776 * reorder due to extra queueing.
777 */
778 ifp->if_ipackets++;
779 ifp->if_ibytes += m->m_pkthdr.len;
780 netisr_dispatch(NETISR_IPV6, m);
781 }
782
783 /* ARGSUSED */
784 static void
785 stf_rtrequest(cmd, rt, info)
786 int cmd;
787 struct rtentry *rt;
788 struct rt_addrinfo *info;
789 {
790 RT_LOCK_ASSERT(rt);
791
792 if (rt)
793 rt->rt_rmx.rmx_mtu = IPV6_MMTU;
794 }
795
796 static int
797 stf_ioctl(ifp, cmd, data)
798 struct ifnet *ifp;
799 u_long cmd;
800 caddr_t data;
801 {
802 struct ifaddr *ifa;
803 struct ifreq *ifr;
804 struct sockaddr_in6 *sin6;
805 struct in_addr addr;
806 int error;
807
808 error = 0;
809 switch (cmd) {
810 case SIOCSIFADDR:
811 ifa = (struct ifaddr *)data;
812 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) {
813 error = EAFNOSUPPORT;
814 break;
815 }
816 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
817 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) {
818 error = EINVAL;
819 break;
820 }
821 bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr));
822 if (isrfc1918addr(&addr)) {
823 error = EINVAL;
824 break;
825 }
826
827 ifa->ifa_rtrequest = stf_rtrequest;
828 ifp->if_flags |= IFF_UP;
829 break;
830
831 case SIOCADDMULTI:
832 case SIOCDELMULTI:
833 ifr = (struct ifreq *)data;
834 if (ifr && ifr->ifr_addr.sa_family == AF_INET6)
835 ;
836 else
837 error = EAFNOSUPPORT;
838 break;
839
840 default:
841 error = EINVAL;
842 break;
843 }
844
845 return error;
846 }
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