FreeBSD/Linux Kernel Cross Reference
sys/net/if_stf.c
1 /* $FreeBSD$ */
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
80 #include <sys/param.h>
81 #include <sys/systm.h>
82 #include <sys/socket.h>
83 #include <sys/sockio.h>
84 #include <sys/mbuf.h>
85 #include <sys/errno.h>
86 #include <sys/kernel.h>
87 #include <sys/module.h>
88 #include <sys/protosw.h>
89 #include <sys/proc.h>
90 #include <sys/queue.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_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 #include <net/vnet.h>
103
104 #include <netinet/in.h>
105 #include <netinet/in_systm.h>
106 #include <netinet/ip.h>
107 #include <netinet/ip_var.h>
108 #include <netinet/in_var.h>
109
110 #include <netinet/ip6.h>
111 #include <netinet6/ip6_var.h>
112 #include <netinet6/in6_var.h>
113 #include <netinet/ip_ecn.h>
114
115 #include <netinet/ip_encap.h>
116
117 #include <machine/stdarg.h>
118
119 #include <net/bpf.h>
120
121 #include <security/mac/mac_framework.h>
122
123 SYSCTL_DECL(_net_link);
124 static SYSCTL_NODE(_net_link, IFT_STF, stf, CTLFLAG_RW, 0, "6to4 Interface");
125
126 static int stf_route_cache = 1;
127 SYSCTL_INT(_net_link_stf, OID_AUTO, route_cache, CTLFLAG_RW,
128 &stf_route_cache, 0, "Caching of IPv4 routes for 6to4 Output");
129
130 static int stf_permit_rfc1918 = 0;
131 TUNABLE_INT("net.link.stf.permit_rfc1918", &stf_permit_rfc1918);
132 SYSCTL_INT(_net_link_stf, OID_AUTO, permit_rfc1918, CTLFLAG_RW | CTLFLAG_TUN,
133 &stf_permit_rfc1918, 0, "Permit the use of private IPv4 addresses");
134
135 #define STFUNIT 0
136
137 #define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002)
138
139 /*
140 * XXX: Return a pointer with 16-bit aligned. Don't cast it to
141 * struct in_addr *; use bcopy() instead.
142 */
143 #define GET_V4(x) (&(x)->s6_addr16[1])
144
145 struct stf_softc {
146 struct ifnet *sc_ifp;
147 union {
148 struct route __sc_ro4;
149 struct route_in6 __sc_ro6; /* just for safety */
150 } __sc_ro46;
151 #define sc_ro __sc_ro46.__sc_ro4
152 struct mtx sc_ro_mtx;
153 u_int sc_fibnum;
154 const struct encaptab *encap_cookie;
155 };
156 #define STF2IFP(sc) ((sc)->sc_ifp)
157
158 static const char stfname[] = "stf";
159
160 /*
161 * Note that mutable fields in the softc are not currently locked.
162 * We do lock sc_ro in stf_output though.
163 */
164 static MALLOC_DEFINE(M_STF, stfname, "6to4 Tunnel Interface");
165 static const int ip_stf_ttl = 40;
166
167 extern struct domain inetdomain;
168 struct protosw in_stf_protosw = {
169 .pr_type = SOCK_RAW,
170 .pr_domain = &inetdomain,
171 .pr_protocol = IPPROTO_IPV6,
172 .pr_flags = PR_ATOMIC|PR_ADDR,
173 .pr_input = in_stf_input,
174 .pr_output = (pr_output_t *)rip_output,
175 .pr_ctloutput = rip_ctloutput,
176 .pr_usrreqs = &rip_usrreqs
177 };
178
179 static char *stfnames[] = {"stf0", "stf", "6to4", NULL};
180
181 static int stfmodevent(module_t, int, void *);
182 static int stf_encapcheck(const struct mbuf *, int, int, void *);
183 static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *);
184 static int stf_output(struct ifnet *, struct mbuf *, const struct sockaddr *,
185 struct route *);
186 static int isrfc1918addr(struct in_addr *);
187 static int stf_checkaddr4(struct stf_softc *, struct in_addr *,
188 struct ifnet *);
189 static int stf_checkaddr6(struct stf_softc *, struct in6_addr *,
190 struct ifnet *);
191 static void stf_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
192 static int stf_ioctl(struct ifnet *, u_long, caddr_t);
193
194 static int stf_clone_match(struct if_clone *, const char *);
195 static int stf_clone_create(struct if_clone *, char *, size_t, caddr_t);
196 static int stf_clone_destroy(struct if_clone *, struct ifnet *);
197 static struct if_clone *stf_cloner;
198
199 static int
200 stf_clone_match(struct if_clone *ifc, const char *name)
201 {
202 int i;
203
204 for(i = 0; stfnames[i] != NULL; i++) {
205 if (strcmp(stfnames[i], name) == 0)
206 return (1);
207 }
208
209 return (0);
210 }
211
212 static int
213 stf_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
214 {
215 int err, unit;
216 struct stf_softc *sc;
217 struct ifnet *ifp;
218
219 /*
220 * We can only have one unit, but since unit allocation is
221 * already locked, we use it to keep from allocating extra
222 * interfaces.
223 */
224 unit = STFUNIT;
225 err = ifc_alloc_unit(ifc, &unit);
226 if (err != 0)
227 return (err);
228
229 sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO);
230 ifp = STF2IFP(sc) = if_alloc(IFT_STF);
231 if (ifp == NULL) {
232 free(sc, M_STF);
233 ifc_free_unit(ifc, unit);
234 return (ENOSPC);
235 }
236 ifp->if_softc = sc;
237 sc->sc_fibnum = curthread->td_proc->p_fibnum;
238
239 /*
240 * Set the name manually rather then using if_initname because
241 * we don't conform to the default naming convention for interfaces.
242 */
243 strlcpy(ifp->if_xname, name, IFNAMSIZ);
244 ifp->if_dname = stfname;
245 ifp->if_dunit = IF_DUNIT_NONE;
246
247 mtx_init(&(sc)->sc_ro_mtx, "stf ro", NULL, MTX_DEF);
248 sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6,
249 stf_encapcheck, &in_stf_protosw, sc);
250 if (sc->encap_cookie == NULL) {
251 if_printf(ifp, "attach failed\n");
252 free(sc, M_STF);
253 ifc_free_unit(ifc, unit);
254 return (ENOMEM);
255 }
256
257 ifp->if_mtu = IPV6_MMTU;
258 ifp->if_ioctl = stf_ioctl;
259 ifp->if_output = stf_output;
260 ifp->if_snd.ifq_maxlen = ifqmaxlen;
261 if_attach(ifp);
262 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
263 return (0);
264 }
265
266 static int
267 stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
268 {
269 struct stf_softc *sc = ifp->if_softc;
270 int err;
271
272 err = encap_detach(sc->encap_cookie);
273 KASSERT(err == 0, ("Unexpected error detaching encap_cookie"));
274 mtx_destroy(&(sc)->sc_ro_mtx);
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
285 static int
286 stfmodevent(mod, type, data)
287 module_t mod;
288 int type;
289 void *data;
290 {
291
292 switch (type) {
293 case MOD_LOAD:
294 stf_cloner = if_clone_advanced(stfname, 0, stf_clone_match,
295 stf_clone_create, stf_clone_destroy);
296 break;
297 case MOD_UNLOAD:
298 if_clone_detach(stf_cloner);
299 break;
300 default:
301 return (EOPNOTSUPP);
302 }
303
304 return (0);
305 }
306
307 static moduledata_t stf_mod = {
308 "if_stf",
309 stfmodevent,
310 0
311 };
312
313 DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
314
315 static int
316 stf_encapcheck(m, off, proto, arg)
317 const struct mbuf *m;
318 int off;
319 int proto;
320 void *arg;
321 {
322 struct ip ip;
323 struct in6_ifaddr *ia6;
324 struct stf_softc *sc;
325 struct in_addr a, b, mask;
326
327 sc = (struct stf_softc *)arg;
328 if (sc == NULL)
329 return 0;
330
331 if ((STF2IFP(sc)->if_flags & IFF_UP) == 0)
332 return 0;
333
334 /* IFF_LINK0 means "no decapsulation" */
335 if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0)
336 return 0;
337
338 if (proto != IPPROTO_IPV6)
339 return 0;
340
341 /* LINTED const cast */
342 m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip);
343
344 if (ip.ip_v != 4)
345 return 0;
346
347 ia6 = stf_getsrcifa6(STF2IFP(sc));
348 if (ia6 == NULL)
349 return 0;
350
351 /*
352 * check if IPv4 dst matches the IPv4 address derived from the
353 * local 6to4 address.
354 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:...
355 */
356 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst,
357 sizeof(ip.ip_dst)) != 0) {
358 ifa_free(&ia6->ia_ifa);
359 return 0;
360 }
361
362 /*
363 * check if IPv4 src matches the IPv4 address derived from the
364 * local 6to4 address masked by prefixmask.
365 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24
366 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24
367 */
368 bzero(&a, sizeof(a));
369 bcopy(GET_V4(&ia6->ia_addr.sin6_addr), &a, sizeof(a));
370 bcopy(GET_V4(&ia6->ia_prefixmask.sin6_addr), &mask, sizeof(mask));
371 ifa_free(&ia6->ia_ifa);
372 a.s_addr &= mask.s_addr;
373 b = ip.ip_src;
374 b.s_addr &= mask.s_addr;
375 if (a.s_addr != b.s_addr)
376 return 0;
377
378 /* stf interface makes single side match only */
379 return 32;
380 }
381
382 static struct in6_ifaddr *
383 stf_getsrcifa6(ifp)
384 struct ifnet *ifp;
385 {
386 struct ifaddr *ia;
387 struct sockaddr_in6 *sin6;
388 struct in_addr in;
389
390 if_addr_rlock(ifp);
391 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
392 if (ia->ifa_addr->sa_family != AF_INET6)
393 continue;
394 sin6 = (struct sockaddr_in6 *)ia->ifa_addr;
395 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr))
396 continue;
397
398 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in));
399 if (!in_localip(in))
400 continue;
401
402 ifa_ref(ia);
403 if_addr_runlock(ifp);
404 return (struct in6_ifaddr *)ia;
405 }
406 if_addr_runlock(ifp);
407
408 return NULL;
409 }
410
411 static int
412 stf_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
413 struct route *ro)
414 {
415 struct stf_softc *sc;
416 const struct sockaddr_in6 *dst6;
417 struct route *cached_route;
418 struct in_addr in4;
419 const void *ptr;
420 struct sockaddr_in *dst4;
421 u_int8_t tos;
422 struct ip *ip;
423 struct ip6_hdr *ip6;
424 struct in6_ifaddr *ia6;
425 int error;
426
427 #ifdef MAC
428 error = mac_ifnet_check_transmit(ifp, m);
429 if (error) {
430 m_freem(m);
431 return (error);
432 }
433 #endif
434
435 sc = ifp->if_softc;
436 dst6 = (const struct sockaddr_in6 *)dst;
437
438 /* just in case */
439 if ((ifp->if_flags & IFF_UP) == 0) {
440 m_freem(m);
441 ifp->if_oerrors++;
442 return ENETDOWN;
443 }
444
445 /*
446 * If we don't have an ip4 address that match my inner ip6 address,
447 * we shouldn't generate output. Without this check, we'll end up
448 * using wrong IPv4 source.
449 */
450 ia6 = stf_getsrcifa6(ifp);
451 if (ia6 == NULL) {
452 m_freem(m);
453 ifp->if_oerrors++;
454 return ENETDOWN;
455 }
456
457 if (m->m_len < sizeof(*ip6)) {
458 m = m_pullup(m, sizeof(*ip6));
459 if (!m) {
460 ifa_free(&ia6->ia_ifa);
461 ifp->if_oerrors++;
462 return ENOBUFS;
463 }
464 }
465 ip6 = mtod(m, struct ip6_hdr *);
466 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
467
468 /*
469 * Pickup the right outer dst addr from the list of candidates.
470 * ip6_dst has priority as it may be able to give us shorter IPv4 hops.
471 */
472 ptr = NULL;
473 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst))
474 ptr = GET_V4(&ip6->ip6_dst);
475 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr))
476 ptr = GET_V4(&dst6->sin6_addr);
477 else {
478 ifa_free(&ia6->ia_ifa);
479 m_freem(m);
480 ifp->if_oerrors++;
481 return ENETUNREACH;
482 }
483 bcopy(ptr, &in4, sizeof(in4));
484
485 if (bpf_peers_present(ifp->if_bpf)) {
486 /*
487 * We need to prepend the address family as
488 * a four byte field. Cons up a dummy header
489 * to pacify bpf. This is safe because bpf
490 * will only read from the mbuf (i.e., it won't
491 * try to free it or keep a pointer a to it).
492 */
493 u_int af = AF_INET6;
494 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
495 }
496
497 M_PREPEND(m, sizeof(struct ip), M_NOWAIT);
498 if (m == NULL) {
499 ifa_free(&ia6->ia_ifa);
500 ifp->if_oerrors++;
501 return ENOBUFS;
502 }
503 ip = mtod(m, struct ip *);
504
505 bzero(ip, sizeof(*ip));
506
507 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr),
508 &ip->ip_src, sizeof(ip->ip_src));
509 ifa_free(&ia6->ia_ifa);
510 bcopy(&in4, &ip->ip_dst, sizeof(ip->ip_dst));
511 ip->ip_p = IPPROTO_IPV6;
512 ip->ip_ttl = ip_stf_ttl;
513 ip->ip_len = htons(m->m_pkthdr.len);
514 if (ifp->if_flags & IFF_LINK1)
515 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos);
516 else
517 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos);
518
519 if (!stf_route_cache) {
520 cached_route = NULL;
521 goto sendit;
522 }
523
524 /*
525 * Do we have a cached route?
526 */
527 mtx_lock(&(sc)->sc_ro_mtx);
528 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst;
529 if (dst4->sin_family != AF_INET ||
530 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) {
531 /* cache route doesn't match */
532 dst4->sin_family = AF_INET;
533 dst4->sin_len = sizeof(struct sockaddr_in);
534 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr));
535 if (sc->sc_ro.ro_rt) {
536 RTFREE(sc->sc_ro.ro_rt);
537 sc->sc_ro.ro_rt = NULL;
538 }
539 }
540
541 if (sc->sc_ro.ro_rt == NULL) {
542 rtalloc_fib(&sc->sc_ro, sc->sc_fibnum);
543 if (sc->sc_ro.ro_rt == NULL) {
544 m_freem(m);
545 mtx_unlock(&(sc)->sc_ro_mtx);
546 ifp->if_oerrors++;
547 return ENETUNREACH;
548 }
549 }
550 cached_route = &sc->sc_ro;
551
552 sendit:
553 M_SETFIB(m, sc->sc_fibnum);
554 ifp->if_opackets++;
555 error = ip_output(m, NULL, cached_route, 0, NULL, NULL);
556
557 if (cached_route != NULL)
558 mtx_unlock(&(sc)->sc_ro_mtx);
559 return error;
560 }
561
562 static int
563 isrfc1918addr(in)
564 struct in_addr *in;
565 {
566 /*
567 * returns 1 if private address range:
568 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16
569 */
570 if (stf_permit_rfc1918 == 0 && (
571 (ntohl(in->s_addr) & 0xff000000) >> 24 == 10 ||
572 (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 ||
573 (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168))
574 return 1;
575
576 return 0;
577 }
578
579 static int
580 stf_checkaddr4(sc, in, inifp)
581 struct stf_softc *sc;
582 struct in_addr *in;
583 struct ifnet *inifp; /* incoming interface */
584 {
585 struct in_ifaddr *ia4;
586
587 /*
588 * reject packets with the following address:
589 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8
590 */
591 if (IN_MULTICAST(ntohl(in->s_addr)))
592 return -1;
593 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) {
594 case 0: case 127: case 255:
595 return -1;
596 }
597
598 /*
599 * reject packets with private address range.
600 * (requirement from RFC3056 section 2 1st paragraph)
601 */
602 if (isrfc1918addr(in))
603 return -1;
604
605 /*
606 * reject packets with broadcast
607 */
608 IN_IFADDR_RLOCK();
609 TAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) {
610 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
611 continue;
612 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) {
613 IN_IFADDR_RUNLOCK();
614 return -1;
615 }
616 }
617 IN_IFADDR_RUNLOCK();
618
619 /*
620 * perform ingress filter
621 */
622 if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) {
623 struct sockaddr_in sin;
624 struct rtentry *rt;
625
626 bzero(&sin, sizeof(sin));
627 sin.sin_family = AF_INET;
628 sin.sin_len = sizeof(struct sockaddr_in);
629 sin.sin_addr = *in;
630 rt = rtalloc1_fib((struct sockaddr *)&sin, 0,
631 0UL, sc->sc_fibnum);
632 if (!rt || rt->rt_ifp != inifp) {
633 #if 0
634 log(LOG_WARNING, "%s: packet from 0x%x dropped "
635 "due to ingress filter\n", if_name(STF2IFP(sc)),
636 (u_int32_t)ntohl(sin.sin_addr.s_addr));
637 #endif
638 if (rt)
639 RTFREE_LOCKED(rt);
640 return -1;
641 }
642 RTFREE_LOCKED(rt);
643 }
644
645 return 0;
646 }
647
648 static int
649 stf_checkaddr6(sc, in6, inifp)
650 struct stf_softc *sc;
651 struct in6_addr *in6;
652 struct ifnet *inifp; /* incoming interface */
653 {
654 /*
655 * check 6to4 addresses
656 */
657 if (IN6_IS_ADDR_6TO4(in6)) {
658 struct in_addr in4;
659 bcopy(GET_V4(in6), &in4, sizeof(in4));
660 return stf_checkaddr4(sc, &in4, inifp);
661 }
662
663 /*
664 * reject anything that look suspicious. the test is implemented
665 * in ip6_input too, but we check here as well to
666 * (1) reject bad packets earlier, and
667 * (2) to be safe against future ip6_input change.
668 */
669 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6))
670 return -1;
671
672 return 0;
673 }
674
675 void
676 in_stf_input(m, off)
677 struct mbuf *m;
678 int off;
679 {
680 int proto;
681 struct stf_softc *sc;
682 struct ip *ip;
683 struct ip6_hdr *ip6;
684 u_int8_t otos, itos;
685 struct ifnet *ifp;
686
687 proto = mtod(m, struct ip *)->ip_p;
688
689 if (proto != IPPROTO_IPV6) {
690 m_freem(m);
691 return;
692 }
693
694 ip = mtod(m, struct ip *);
695
696 sc = (struct stf_softc *)encap_getarg(m);
697
698 if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) {
699 m_freem(m);
700 return;
701 }
702
703 ifp = STF2IFP(sc);
704
705 #ifdef MAC
706 mac_ifnet_create_mbuf(ifp, m);
707 #endif
708
709 /*
710 * perform sanity check against outer src/dst.
711 * for source, perform ingress filter as well.
712 */
713 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 ||
714 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) {
715 m_freem(m);
716 return;
717 }
718
719 otos = ip->ip_tos;
720 m_adj(m, off);
721
722 if (m->m_len < sizeof(*ip6)) {
723 m = m_pullup(m, sizeof(*ip6));
724 if (!m)
725 return;
726 }
727 ip6 = mtod(m, struct ip6_hdr *);
728
729 /*
730 * perform sanity check against inner src/dst.
731 * for source, perform ingress filter as well.
732 */
733 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 ||
734 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) {
735 m_freem(m);
736 return;
737 }
738
739 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
740 if ((ifp->if_flags & IFF_LINK1) != 0)
741 ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
742 else
743 ip_ecn_egress(ECN_NOCARE, &otos, &itos);
744 ip6->ip6_flow &= ~htonl(0xff << 20);
745 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
746
747 m->m_pkthdr.rcvif = ifp;
748
749 if (bpf_peers_present(ifp->if_bpf)) {
750 /*
751 * We need to prepend the address family as
752 * a four byte field. Cons up a dummy header
753 * to pacify bpf. This is safe because bpf
754 * will only read from the mbuf (i.e., it won't
755 * try to free it or keep a pointer a to it).
756 */
757 u_int32_t af = AF_INET6;
758 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
759 }
760
761 /*
762 * Put the packet to the network layer input queue according to the
763 * specified address family.
764 * See net/if_gif.c for possible issues with packet processing
765 * reorder due to extra queueing.
766 */
767 ifp->if_ipackets++;
768 ifp->if_ibytes += m->m_pkthdr.len;
769 M_SETFIB(m, ifp->if_fib);
770 netisr_dispatch(NETISR_IPV6, m);
771 }
772
773 /* ARGSUSED */
774 static void
775 stf_rtrequest(cmd, rt, info)
776 int cmd;
777 struct rtentry *rt;
778 struct rt_addrinfo *info;
779 {
780 RT_LOCK_ASSERT(rt);
781 rt->rt_mtu = rt->rt_ifp->if_mtu;
782 }
783
784 static int
785 stf_ioctl(ifp, cmd, data)
786 struct ifnet *ifp;
787 u_long cmd;
788 caddr_t data;
789 {
790 struct ifaddr *ifa;
791 struct ifreq *ifr;
792 struct sockaddr_in6 *sin6;
793 struct in_addr addr;
794 int error, mtu;
795
796 error = 0;
797 switch (cmd) {
798 case SIOCSIFADDR:
799 ifa = (struct ifaddr *)data;
800 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) {
801 error = EAFNOSUPPORT;
802 break;
803 }
804 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
805 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) {
806 error = EINVAL;
807 break;
808 }
809 bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr));
810 if (isrfc1918addr(&addr)) {
811 error = EINVAL;
812 break;
813 }
814
815 ifa->ifa_rtrequest = stf_rtrequest;
816 ifp->if_flags |= IFF_UP;
817 break;
818
819 case SIOCADDMULTI:
820 case SIOCDELMULTI:
821 ifr = (struct ifreq *)data;
822 if (ifr && ifr->ifr_addr.sa_family == AF_INET6)
823 ;
824 else
825 error = EAFNOSUPPORT;
826 break;
827
828 case SIOCGIFMTU:
829 break;
830
831 case SIOCSIFMTU:
832 ifr = (struct ifreq *)data;
833 mtu = ifr->ifr_mtu;
834 /* RFC 4213 3.2 ideal world MTU */
835 if (mtu < IPV6_MINMTU || mtu > IF_MAXMTU - 20)
836 return (EINVAL);
837 ifp->if_mtu = mtu;
838 break;
839
840 default:
841 error = EINVAL;
842 break;
843 }
844
845 return error;
846 }
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