1 | /* $NetBSD: if_stf.c,v 1.99 2016/08/18 11:38:58 knakahara Exp $ */ |
2 | /* $KAME: if_stf.c,v 1.62 2001/06/07 22:32:16 itojun 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 <sys/cdefs.h> |
78 | __KERNEL_RCSID(0, "$NetBSD: if_stf.c,v 1.99 2016/08/18 11:38:58 knakahara Exp $" ); |
79 | |
80 | #ifdef _KERNEL_OPT |
81 | #include "opt_inet.h" |
82 | #include "stf.h" |
83 | #endif |
84 | |
85 | #ifndef INET6 |
86 | #error "pseudo-device stf requires options INET6" |
87 | #endif |
88 | |
89 | #include <sys/param.h> |
90 | #include <sys/systm.h> |
91 | #include <sys/socket.h> |
92 | #include <sys/sockio.h> |
93 | #include <sys/mbuf.h> |
94 | #include <sys/errno.h> |
95 | #include <sys/ioctl.h> |
96 | #include <sys/proc.h> |
97 | #include <sys/queue.h> |
98 | #include <sys/syslog.h> |
99 | #include <sys/device.h> |
100 | #include <sys/module.h> |
101 | |
102 | #include <sys/cpu.h> |
103 | |
104 | #include <net/if.h> |
105 | #include <net/route.h> |
106 | #include <net/netisr.h> |
107 | #include <net/if_types.h> |
108 | #include <net/if_stf.h> |
109 | |
110 | #include <netinet/in.h> |
111 | #include <netinet/in_systm.h> |
112 | #include <netinet/ip.h> |
113 | #include <netinet/ip_var.h> |
114 | #include <netinet/in_var.h> |
115 | |
116 | #include <netinet/ip6.h> |
117 | #include <netinet6/ip6_var.h> |
118 | #include <netinet6/in6_var.h> |
119 | #include <netinet/ip_ecn.h> |
120 | |
121 | #include <netinet/ip_encap.h> |
122 | |
123 | #include <net/net_osdep.h> |
124 | |
125 | #include <net/bpf.h> |
126 | |
127 | #include "ioconf.h" |
128 | |
129 | #define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002) |
130 | #define GET_V4(x) ((const struct in_addr *)(&(x)->s6_addr16[1])) |
131 | |
132 | struct stf_softc { |
133 | struct ifnet sc_if; /* common area */ |
134 | struct route sc_ro; |
135 | const struct encaptab *encap_cookie; |
136 | LIST_ENTRY(stf_softc) sc_list; |
137 | }; |
138 | |
139 | static LIST_HEAD(, stf_softc) stf_softc_list; |
140 | |
141 | static int stf_clone_create(struct if_clone *, int); |
142 | static int stf_clone_destroy(struct ifnet *); |
143 | |
144 | struct if_clone stf_cloner = |
145 | IF_CLONE_INITIALIZER("stf" , stf_clone_create, stf_clone_destroy); |
146 | |
147 | static int ip_stf_ttl = STF_TTL; |
148 | |
149 | extern struct domain inetdomain; |
150 | |
151 | static const struct encapsw in_stf_encapsw = |
152 | { |
153 | .encapsw4 = { |
154 | .pr_input = in_stf_input, |
155 | .pr_ctlinput = NULL, |
156 | } |
157 | }; |
158 | |
159 | static int stf_encapcheck(struct mbuf *, int, int, void *); |
160 | static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *); |
161 | static int stf_output(struct ifnet *, struct mbuf *, const struct sockaddr *, |
162 | const struct rtentry *); |
163 | static int isrfc1918addr(const struct in_addr *); |
164 | static int stf_checkaddr4(struct stf_softc *, const struct in_addr *, |
165 | struct ifnet *); |
166 | static int stf_checkaddr6(struct stf_softc *, const struct in6_addr *, |
167 | struct ifnet *); |
168 | static void stf_rtrequest(int, struct rtentry *, const struct rt_addrinfo *); |
169 | static int stf_ioctl(struct ifnet *, u_long, void *); |
170 | |
171 | /* ARGSUSED */ |
172 | void |
173 | stfattach(int count) |
174 | { |
175 | |
176 | /* |
177 | * Nothing to do here, initialization is handled by the |
178 | * module initialization code in stfinit() below). |
179 | */ |
180 | } |
181 | |
182 | static void |
183 | stfinit(void) |
184 | { |
185 | |
186 | LIST_INIT(&stf_softc_list); |
187 | if_clone_attach(&stf_cloner); |
188 | } |
189 | |
190 | static int |
191 | stfdetach(void) |
192 | { |
193 | int error = 0; |
194 | |
195 | if (!LIST_EMPTY(&stf_softc_list)) |
196 | error = EBUSY; |
197 | |
198 | if (error == 0) |
199 | if_clone_detach(&stf_cloner); |
200 | |
201 | return error; |
202 | } |
203 | |
204 | static int |
205 | stf_clone_create(struct if_clone *ifc, int unit) |
206 | { |
207 | struct stf_softc *sc; |
208 | int error; |
209 | |
210 | sc = malloc(sizeof(struct stf_softc), M_DEVBUF, M_WAIT|M_ZERO); |
211 | if_initname(&sc->sc_if, ifc->ifc_name, unit); |
212 | |
213 | error = encap_lock_enter(); |
214 | if (error) { |
215 | free(sc, M_DEVBUF); |
216 | return error; |
217 | } |
218 | |
219 | if (LIST_FIRST(&stf_softc_list) != NULL) { |
220 | /* Only one stf interface is allowed. */ |
221 | encap_lock_exit(); |
222 | free(sc, M_DEVBUF); |
223 | return (EEXIST); |
224 | } |
225 | |
226 | sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6, |
227 | stf_encapcheck, &in_stf_encapsw, sc); |
228 | encap_lock_exit(); |
229 | if (sc->encap_cookie == NULL) { |
230 | printf("%s: unable to attach encap\n" , if_name(&sc->sc_if)); |
231 | free(sc, M_DEVBUF); |
232 | return (EIO); /* XXX */ |
233 | } |
234 | |
235 | sc->sc_if.if_mtu = STF_MTU; |
236 | sc->sc_if.if_flags = 0; |
237 | sc->sc_if.if_ioctl = stf_ioctl; |
238 | sc->sc_if.if_output = stf_output; |
239 | sc->sc_if.if_type = IFT_STF; |
240 | sc->sc_if.if_dlt = DLT_NULL; |
241 | if_attach(&sc->sc_if); |
242 | if_alloc_sadl(&sc->sc_if); |
243 | bpf_attach(&sc->sc_if, DLT_NULL, sizeof(u_int)); |
244 | LIST_INSERT_HEAD(&stf_softc_list, sc, sc_list); |
245 | return (0); |
246 | } |
247 | |
248 | static int |
249 | stf_clone_destroy(struct ifnet *ifp) |
250 | { |
251 | struct stf_softc *sc = (void *) ifp; |
252 | |
253 | encap_lock_enter(); |
254 | LIST_REMOVE(sc, sc_list); |
255 | encap_detach(sc->encap_cookie); |
256 | encap_lock_exit(); |
257 | bpf_detach(ifp); |
258 | if_detach(ifp); |
259 | rtcache_free(&sc->sc_ro); |
260 | free(sc, M_DEVBUF); |
261 | |
262 | return (0); |
263 | } |
264 | |
265 | static int |
266 | stf_encapcheck(struct mbuf *m, int off, int proto, void *arg) |
267 | { |
268 | struct ip ip; |
269 | struct in6_ifaddr *ia6; |
270 | struct stf_softc *sc; |
271 | struct in_addr a, b; |
272 | |
273 | sc = (struct stf_softc *)arg; |
274 | if (sc == NULL) |
275 | return 0; |
276 | |
277 | if ((sc->sc_if.if_flags & IFF_UP) == 0) |
278 | return 0; |
279 | |
280 | /* IFF_LINK0 means "no decapsulation" */ |
281 | if ((sc->sc_if.if_flags & IFF_LINK0) != 0) |
282 | return 0; |
283 | |
284 | if (proto != IPPROTO_IPV6) |
285 | return 0; |
286 | |
287 | m_copydata(m, 0, sizeof(ip), (void *)&ip); |
288 | |
289 | if (ip.ip_v != 4) |
290 | return 0; |
291 | |
292 | ia6 = stf_getsrcifa6(&sc->sc_if); |
293 | if (ia6 == NULL) |
294 | return 0; |
295 | |
296 | /* |
297 | * check if IPv4 dst matches the IPv4 address derived from the |
298 | * local 6to4 address. |
299 | * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... |
300 | */ |
301 | if (memcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, |
302 | sizeof(ip.ip_dst)) != 0) |
303 | return 0; |
304 | |
305 | /* |
306 | * check if IPv4 src matches the IPv4 address derived from the |
307 | * local 6to4 address masked by prefixmask. |
308 | * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 |
309 | * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 |
310 | */ |
311 | memset(&a, 0, sizeof(a)); |
312 | a.s_addr = GET_V4(&ia6->ia_addr.sin6_addr)->s_addr; |
313 | a.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; |
314 | b = ip.ip_src; |
315 | b.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; |
316 | if (a.s_addr != b.s_addr) |
317 | return 0; |
318 | |
319 | /* stf interface makes single side match only */ |
320 | return 32; |
321 | } |
322 | |
323 | static struct in6_ifaddr * |
324 | stf_getsrcifa6(struct ifnet *ifp) |
325 | { |
326 | struct ifaddr *ifa; |
327 | struct in_ifaddr *ia4; |
328 | struct sockaddr_in6 *sin6; |
329 | struct in_addr in; |
330 | int s; |
331 | |
332 | s = pserialize_read_enter(); |
333 | IFADDR_READER_FOREACH(ifa, ifp) { |
334 | if (ifa->ifa_addr->sa_family != AF_INET6) |
335 | continue; |
336 | sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; |
337 | if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) |
338 | continue; |
339 | |
340 | memcpy(&in, GET_V4(&sin6->sin6_addr), sizeof(in)); |
341 | ia4 = in_get_ia(in); |
342 | if (ia4 == NULL) |
343 | continue; |
344 | |
345 | pserialize_read_exit(s); |
346 | /* TODO NOMPSAFE */ |
347 | return (struct in6_ifaddr *)ifa; |
348 | } |
349 | pserialize_read_exit(s); |
350 | |
351 | return NULL; |
352 | } |
353 | |
354 | static int |
355 | stf_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, |
356 | const struct rtentry *rt0) |
357 | { |
358 | struct rtentry *rt; |
359 | struct stf_softc *sc; |
360 | const struct sockaddr_in6 *dst6; |
361 | const struct in_addr *in4; |
362 | uint8_t tos; |
363 | struct ip *ip; |
364 | struct ip6_hdr *ip6; |
365 | struct in6_ifaddr *ia6; |
366 | union { |
367 | struct sockaddr dst; |
368 | struct sockaddr_in dst4; |
369 | } u; |
370 | |
371 | sc = (struct stf_softc*)ifp; |
372 | dst6 = (const struct sockaddr_in6 *)dst; |
373 | |
374 | /* just in case */ |
375 | if ((ifp->if_flags & IFF_UP) == 0) { |
376 | m_freem(m); |
377 | return ENETDOWN; |
378 | } |
379 | |
380 | /* |
381 | * If we don't have an ip4 address that match my inner ip6 address, |
382 | * we shouldn't generate output. Without this check, we'll end up |
383 | * using wrong IPv4 source. |
384 | */ |
385 | ia6 = stf_getsrcifa6(ifp); |
386 | if (ia6 == NULL) { |
387 | m_freem(m); |
388 | ifp->if_oerrors++; |
389 | return ENETDOWN; |
390 | } |
391 | |
392 | if (m->m_len < sizeof(*ip6)) { |
393 | m = m_pullup(m, sizeof(*ip6)); |
394 | if (m == NULL) { |
395 | ifp->if_oerrors++; |
396 | return ENOBUFS; |
397 | } |
398 | } |
399 | ip6 = mtod(m, struct ip6_hdr *); |
400 | tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; |
401 | |
402 | /* |
403 | * Pickup the right outer dst addr from the list of candidates. |
404 | * ip6_dst has priority as it may be able to give us shorter IPv4 hops. |
405 | */ |
406 | if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) |
407 | in4 = GET_V4(&ip6->ip6_dst); |
408 | else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) |
409 | in4 = GET_V4(&dst6->sin6_addr); |
410 | else { |
411 | m_freem(m); |
412 | ifp->if_oerrors++; |
413 | return ENETUNREACH; |
414 | } |
415 | |
416 | bpf_mtap_af(ifp, AF_INET6, m); |
417 | |
418 | M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); |
419 | if (m && m->m_len < sizeof(struct ip)) |
420 | m = m_pullup(m, sizeof(struct ip)); |
421 | if (m == NULL) { |
422 | ifp->if_oerrors++; |
423 | return ENOBUFS; |
424 | } |
425 | ip = mtod(m, struct ip *); |
426 | |
427 | memset(ip, 0, sizeof(*ip)); |
428 | |
429 | bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), |
430 | &ip->ip_src, sizeof(ip->ip_src)); |
431 | memcpy(&ip->ip_dst, in4, sizeof(ip->ip_dst)); |
432 | ip->ip_p = IPPROTO_IPV6; |
433 | ip->ip_ttl = ip_stf_ttl; |
434 | ip->ip_len = htons(m->m_pkthdr.len); |
435 | if (ifp->if_flags & IFF_LINK1) |
436 | ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); |
437 | else |
438 | ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); |
439 | |
440 | sockaddr_in_init(&u.dst4, &ip->ip_dst, 0); |
441 | if ((rt = rtcache_lookup(&sc->sc_ro, &u.dst)) == NULL) { |
442 | m_freem(m); |
443 | ifp->if_oerrors++; |
444 | return ENETUNREACH; |
445 | } |
446 | |
447 | /* If the route constitutes infinite encapsulation, punt. */ |
448 | if (rt->rt_ifp == ifp) { |
449 | rtcache_free(&sc->sc_ro); |
450 | m_freem(m); |
451 | ifp->if_oerrors++; |
452 | return ENETUNREACH; |
453 | } |
454 | |
455 | ifp->if_opackets++; |
456 | ifp->if_obytes += m->m_pkthdr.len - sizeof(struct ip); |
457 | return ip_output(m, NULL, &sc->sc_ro, 0, NULL, NULL); |
458 | } |
459 | |
460 | static int |
461 | isrfc1918addr(const struct in_addr *in) |
462 | { |
463 | /* |
464 | * returns 1 if private address range: |
465 | * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 |
466 | */ |
467 | if ((ntohl(in->s_addr) & 0xff000000) >> 24 == 10 || |
468 | (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 || |
469 | (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168) |
470 | return 1; |
471 | |
472 | return 0; |
473 | } |
474 | |
475 | static int |
476 | stf_checkaddr4(struct stf_softc *sc, const struct in_addr *in, |
477 | struct ifnet *inifp /*incoming interface*/) |
478 | { |
479 | struct in_ifaddr *ia4; |
480 | |
481 | /* |
482 | * reject packets with the following address: |
483 | * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 |
484 | */ |
485 | if (IN_MULTICAST(in->s_addr)) |
486 | return -1; |
487 | switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { |
488 | case 0: case 127: case 255: |
489 | return -1; |
490 | } |
491 | |
492 | /* |
493 | * reject packets with private address range. |
494 | * (requirement from RFC3056 section 2 1st paragraph) |
495 | */ |
496 | if (isrfc1918addr(in)) |
497 | return -1; |
498 | |
499 | /* |
500 | * reject packet with IPv4 link-local (169.254.0.0/16), |
501 | * as suggested in draft-savola-v6ops-6to4-security-00.txt |
502 | */ |
503 | if (((ntohl(in->s_addr) & 0xff000000) >> 24) == 169 && |
504 | ((ntohl(in->s_addr) & 0x00ff0000) >> 16) == 254) |
505 | return -1; |
506 | |
507 | /* |
508 | * reject packets with broadcast |
509 | */ |
510 | IN_ADDRLIST_READER_FOREACH(ia4) { |
511 | if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) |
512 | continue; |
513 | if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) |
514 | return -1; |
515 | } |
516 | |
517 | /* |
518 | * perform ingress filter |
519 | */ |
520 | if (sc && (sc->sc_if.if_flags & IFF_LINK2) == 0 && inifp) { |
521 | struct sockaddr_in sin; |
522 | struct rtentry *rt; |
523 | |
524 | memset(&sin, 0, sizeof(sin)); |
525 | sin.sin_family = AF_INET; |
526 | sin.sin_len = sizeof(struct sockaddr_in); |
527 | sin.sin_addr = *in; |
528 | rt = rtalloc1((struct sockaddr *)&sin, 0); |
529 | if (!rt || rt->rt_ifp != inifp) { |
530 | #if 0 |
531 | log(LOG_WARNING, "%s: packet from 0x%x dropped " |
532 | "due to ingress filter\n" , if_name(&sc->sc_if), |
533 | (uint32_t)ntohl(sin.sin_addr.s_addr)); |
534 | #endif |
535 | if (rt) |
536 | rtfree(rt); |
537 | return -1; |
538 | } |
539 | rtfree(rt); |
540 | } |
541 | |
542 | return 0; |
543 | } |
544 | |
545 | static int |
546 | stf_checkaddr6(struct stf_softc *sc, const struct in6_addr *in6, |
547 | struct ifnet *inifp /*incoming interface*/) |
548 | { |
549 | |
550 | /* |
551 | * check 6to4 addresses |
552 | */ |
553 | if (IN6_IS_ADDR_6TO4(in6)) |
554 | return stf_checkaddr4(sc, GET_V4(in6), inifp); |
555 | |
556 | /* |
557 | * reject anything that look suspicious. the test is implemented |
558 | * in ip6_input too, but we check here as well to |
559 | * (1) reject bad packets earlier, and |
560 | * (2) to be safe against future ip6_input change. |
561 | */ |
562 | if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) |
563 | return -1; |
564 | |
565 | /* |
566 | * reject link-local and site-local unicast |
567 | * as suggested in draft-savola-v6ops-6to4-security-00.txt |
568 | */ |
569 | if (IN6_IS_ADDR_LINKLOCAL(in6) || IN6_IS_ADDR_SITELOCAL(in6)) |
570 | return -1; |
571 | |
572 | /* |
573 | * reject node-local and link-local multicast |
574 | * as suggested in draft-savola-v6ops-6to4-security-00.txt |
575 | */ |
576 | if (IN6_IS_ADDR_MC_NODELOCAL(in6) || IN6_IS_ADDR_MC_LINKLOCAL(in6)) |
577 | return -1; |
578 | |
579 | return 0; |
580 | } |
581 | |
582 | void |
583 | in_stf_input(struct mbuf *m, int off, int proto) |
584 | { |
585 | int s; |
586 | struct stf_softc *sc; |
587 | struct ip *ip; |
588 | struct ip6_hdr *ip6; |
589 | uint8_t otos, itos; |
590 | struct ifnet *ifp; |
591 | size_t pktlen; |
592 | |
593 | if (proto != IPPROTO_IPV6) { |
594 | m_freem(m); |
595 | return; |
596 | } |
597 | |
598 | ip = mtod(m, struct ip *); |
599 | |
600 | sc = (struct stf_softc *)encap_getarg(m); |
601 | |
602 | if (sc == NULL || (sc->sc_if.if_flags & IFF_UP) == 0) { |
603 | m_freem(m); |
604 | return; |
605 | } |
606 | |
607 | ifp = &sc->sc_if; |
608 | |
609 | /* |
610 | * perform sanity check against outer src/dst. |
611 | * for source, perform ingress filter as well. |
612 | */ |
613 | if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || |
614 | stf_checkaddr4(sc, &ip->ip_src, m_get_rcvif_NOMPSAFE(m)) < 0) { |
615 | m_freem(m); |
616 | return; |
617 | } |
618 | |
619 | otos = ip->ip_tos; |
620 | m_adj(m, off); |
621 | |
622 | if (m->m_len < sizeof(*ip6)) { |
623 | m = m_pullup(m, sizeof(*ip6)); |
624 | if (!m) |
625 | return; |
626 | } |
627 | ip6 = mtod(m, struct ip6_hdr *); |
628 | |
629 | /* |
630 | * perform sanity check against inner src/dst. |
631 | * for source, perform ingress filter as well. |
632 | */ |
633 | if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || |
634 | stf_checkaddr6(sc, &ip6->ip6_src, m_get_rcvif_NOMPSAFE(m)) < 0) { |
635 | m_freem(m); |
636 | return; |
637 | } |
638 | |
639 | itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; |
640 | if ((ifp->if_flags & IFF_LINK1) != 0) |
641 | ip_ecn_egress(ECN_ALLOWED, &otos, &itos); |
642 | else |
643 | ip_ecn_egress(ECN_NOCARE, &otos, &itos); |
644 | ip6->ip6_flow &= ~htonl(0xff << 20); |
645 | ip6->ip6_flow |= htonl((uint32_t)itos << 20); |
646 | |
647 | pktlen = m->m_pkthdr.len; |
648 | m_set_rcvif(m, ifp); |
649 | |
650 | bpf_mtap_af(ifp, AF_INET6, m); |
651 | |
652 | /* |
653 | * Put the packet to the network layer input queue according to the |
654 | * specified address family. |
655 | * See net/if_gif.c for possible issues with packet processing |
656 | * reorder due to extra queueing. |
657 | */ |
658 | |
659 | s = splnet(); |
660 | if (__predict_true(pktq_enqueue(ip6_pktq, m, 0))) { |
661 | ifp->if_ipackets++; |
662 | ifp->if_ibytes += pktlen; |
663 | } else { |
664 | m_freem(m); |
665 | } |
666 | splx(s); |
667 | |
668 | return; |
669 | } |
670 | |
671 | /* ARGSUSED */ |
672 | static void |
673 | stf_rtrequest(int cmd, struct rtentry *rt, |
674 | const struct rt_addrinfo *info) |
675 | { |
676 | if (rt != NULL) { |
677 | struct stf_softc *sc; |
678 | |
679 | sc = LIST_FIRST(&stf_softc_list); |
680 | rt->rt_rmx.rmx_mtu = (sc != NULL) ? sc->sc_if.if_mtu : STF_MTU; |
681 | } |
682 | } |
683 | |
684 | static int |
685 | stf_ioctl(struct ifnet *ifp, u_long cmd, void *data) |
686 | { |
687 | struct ifaddr *ifa; |
688 | struct ifreq *ifr = data; |
689 | struct sockaddr_in6 *sin6; |
690 | int error; |
691 | |
692 | error = 0; |
693 | switch (cmd) { |
694 | case SIOCINITIFADDR: |
695 | ifa = (struct ifaddr *)data; |
696 | if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { |
697 | error = EAFNOSUPPORT; |
698 | break; |
699 | } |
700 | sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; |
701 | if (IN6_IS_ADDR_6TO4(&sin6->sin6_addr) && |
702 | !isrfc1918addr(GET_V4(&sin6->sin6_addr))) { |
703 | ifa->ifa_rtrequest = stf_rtrequest; |
704 | ifp->if_flags |= IFF_UP; |
705 | } else |
706 | error = EINVAL; |
707 | break; |
708 | |
709 | case SIOCADDMULTI: |
710 | case SIOCDELMULTI: |
711 | if (ifr != NULL && |
712 | ifreq_getaddr(cmd, ifr)->sa_family == AF_INET6) |
713 | ; |
714 | else |
715 | error = EAFNOSUPPORT; |
716 | break; |
717 | |
718 | case SIOCSIFMTU: |
719 | if (ifr->ifr_mtu < STF_MTU_MIN || ifr->ifr_mtu > STF_MTU_MAX) |
720 | return EINVAL; |
721 | else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) |
722 | error = 0; |
723 | break; |
724 | |
725 | default: |
726 | error = ifioctl_common(ifp, cmd, data); |
727 | break; |
728 | } |
729 | |
730 | return error; |
731 | } |
732 | |
733 | /* |
734 | * Module infrastructure |
735 | */ |
736 | #include "if_module.h" |
737 | |
738 | IF_MODULE(MODULE_CLASS_DRIVER, stf, "" ) |
739 | |