1 | /* |
2 | * Copyright (c) 2000-2020 Apple Inc. All rights reserved. |
3 | * |
4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
5 | * |
6 | * This file contains Original Code and/or Modifications of Original Code |
7 | * as defined in and that are subject to the Apple Public Source License |
8 | * Version 2.0 (the 'License'). You may not use this file except in |
9 | * compliance with the License. The rights granted to you under the License |
10 | * may not be used to create, or enable the creation or redistribution of, |
11 | * unlawful or unlicensed copies of an Apple operating system, or to |
12 | * circumvent, violate, or enable the circumvention or violation of, any |
13 | * terms of an Apple operating system software license agreement. |
14 | * |
15 | * Please obtain a copy of the License at |
16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. |
17 | * |
18 | * The Original Code and all software distributed under the License are |
19 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
22 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
23 | * Please see the License for the specific language governing rights and |
24 | * limitations under the License. |
25 | * |
26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
27 | */ |
28 | |
29 | /* $FreeBSD: src/sys/net/if_stf.c,v 1.1.2.6 2001/07/24 19:10:18 brooks Exp $ */ |
30 | /* $KAME: if_stf.c,v 1.62 2001/06/07 22:32:16 itojun Exp $ */ |
31 | |
32 | /* |
33 | * Copyright (C) 2000 WIDE Project. |
34 | * All rights reserved. |
35 | * |
36 | * Redistribution and use in source and binary forms, with or without |
37 | * modification, are permitted provided that the following conditions |
38 | * are met: |
39 | * 1. Redistributions of source code must retain the above copyright |
40 | * notice, this list of conditions and the following disclaimer. |
41 | * 2. Redistributions in binary form must reproduce the above copyright |
42 | * notice, this list of conditions and the following disclaimer in the |
43 | * documentation and/or other materials provided with the distribution. |
44 | * 3. Neither the name of the project nor the names of its contributors |
45 | * may be used to endorse or promote products derived from this software |
46 | * without specific prior written permission. |
47 | * |
48 | * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND |
49 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
50 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
51 | * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE |
52 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
53 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
54 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
55 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
56 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
57 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
58 | * SUCH DAMAGE. |
59 | */ |
60 | /* |
61 | * NOTICE: This file was modified by SPARTA, Inc. in 2006 to introduce |
62 | * support for mandatory and extensible security protections. This notice |
63 | * is included in support of clause 2.2 (b) of the Apple Public License, |
64 | * Version 2.0. |
65 | */ |
66 | |
67 | /* |
68 | * 6to4 interface, based on RFC3056. |
69 | * |
70 | * 6to4 interface is NOT capable of link-layer (I mean, IPv4) multicasting. |
71 | * There is no address mapping defined from IPv6 multicast address to IPv4 |
72 | * address. Therefore, we do not have IFF_MULTICAST on the interface. |
73 | * |
74 | * Due to the lack of address mapping for link-local addresses, we cannot |
75 | * throw packets toward link-local addresses (fe80::x). Also, we cannot throw |
76 | * packets to link-local multicast addresses (ff02::x). |
77 | * |
78 | * Here are interesting symptoms due to the lack of link-local address: |
79 | * |
80 | * Unicast routing exchange: |
81 | * - RIPng: Impossible. Uses link-local multicast packet toward ff02::9, |
82 | * and link-local addresses as nexthop. |
83 | * - OSPFv6: Impossible. OSPFv6 assumes that there's link-local address |
84 | * assigned to the link, and makes use of them. Also, HELLO packets use |
85 | * link-local multicast addresses (ff02::5 and ff02::6). |
86 | * - BGP4+: Maybe. You can only use global address as nexthop, and global |
87 | * address as TCP endpoint address. |
88 | * |
89 | * Multicast routing protocols: |
90 | * - PIM: Hello packet cannot be used to discover adjacent PIM routers. |
91 | * Adjacent PIM routers must be configured manually (is it really spec-wise |
92 | * correct thing to do?). |
93 | * |
94 | * ICMPv6: |
95 | * - Redirects cannot be used due to the lack of link-local address. |
96 | * |
97 | * stf interface does not have, and will not need, a link-local address. |
98 | * It seems to have no real benefit and does not help the above symptoms much. |
99 | * Even if we assign link-locals to interface, we cannot really |
100 | * use link-local unicast/multicast on top of 6to4 cloud (since there's no |
101 | * encapsulation defined for link-local address), and the above analysis does |
102 | * not change. RFC3056 does not mandate the assignment of link-local address |
103 | * either. |
104 | * |
105 | * 6to4 interface has security issues. Refer to |
106 | * http://playground.iijlab.net/i-d/draft-itojun-ipv6-transition-abuse-00.txt |
107 | * for details. The code tries to filter out some of malicious packets. |
108 | * Note that there is no way to be 100% secure. |
109 | */ |
110 | |
111 | #include <sys/param.h> |
112 | #include <sys/systm.h> |
113 | #include <sys/socket.h> |
114 | #include <sys/sockio.h> |
115 | #include <sys/mbuf.h> |
116 | #include <sys/errno.h> |
117 | #include <sys/protosw.h> |
118 | #include <sys/kernel.h> |
119 | #include <sys/syslog.h> |
120 | |
121 | #include <sys/malloc.h> |
122 | |
123 | #include <kern/locks.h> |
124 | |
125 | #include <net/if.h> |
126 | #include <net/route.h> |
127 | #include <net/if_types.h> |
128 | |
129 | #include <netinet/in.h> |
130 | #include <netinet/in_systm.h> |
131 | #include <netinet/ip.h> |
132 | #include <netinet/ip_var.h> |
133 | #include <netinet/in_var.h> |
134 | |
135 | #include <netinet/ip6.h> |
136 | #include <netinet6/ip6_var.h> |
137 | #include <netinet6/in6_var.h> |
138 | #include <netinet/ip_ecn.h> |
139 | |
140 | #include <netinet/ip_encap.h> |
141 | #include <net/kpi_interface.h> |
142 | #include <net/kpi_protocol.h> |
143 | |
144 | |
145 | #include <net/net_osdep.h> |
146 | |
147 | #include <net/bpf.h> |
148 | |
149 | #include <net/sockaddr_utils.h> |
150 | |
151 | #define GET_V4(x) ((const struct in_addr *)(const void *)(&(x)->s6_addr16[1])) |
152 | |
153 | static LCK_GRP_DECLARE(stf_mtx_grp, "stf" ); |
154 | |
155 | struct stf_softc { |
156 | ifnet_t sc_if; /* common area */ |
157 | u_int32_t sc_protocol_family; /* dlil protocol attached */ |
158 | union { |
159 | struct route __sc_ro4; |
160 | struct route_in6 __sc_ro6; /* just for safety */ |
161 | } __sc_ro46; |
162 | #define sc_ro __sc_ro46.__sc_ro4 |
163 | decl_lck_mtx_data(, sc_ro_mtx); |
164 | const struct encaptab *encap_cookie; |
165 | bpf_tap_mode tap_mode; |
166 | bpf_packet_func tap_callback; |
167 | }; |
168 | |
169 | void stfattach(void); |
170 | |
171 | static int ip_stf_ttl = 40; |
172 | |
173 | static void in_stf_input(struct mbuf *, int); |
174 | |
175 | static struct protosw in_stf_protosw = |
176 | { |
177 | .pr_type = SOCK_RAW, |
178 | .pr_protocol = IPPROTO_IPV6, |
179 | .pr_flags = PR_ATOMIC | PR_ADDR, |
180 | .pr_input = in_stf_input, |
181 | .pr_ctloutput = rip_ctloutput, |
182 | .pr_usrreqs = &rip_usrreqs, |
183 | .pr_unlock = rip_unlock, |
184 | }; |
185 | |
186 | static int stf_encapcheck(const struct mbuf *, int, int, void *); |
187 | static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *); |
188 | int stf_pre_output(struct ifnet *, protocol_family_t, struct mbuf **, |
189 | const struct sockaddr *, void *, char *, char *); |
190 | static int stf_checkaddr4(struct stf_softc *, const struct in_addr *, |
191 | struct ifnet *); |
192 | static int stf_checkaddr6(struct stf_softc *, struct in6_addr *, |
193 | struct ifnet *); |
194 | static void stf_rtrequest(int, struct rtentry *, struct sockaddr *); |
195 | static errno_t stf_ioctl(ifnet_t ifp, u_long cmd, void *data); |
196 | static errno_t stf_output(ifnet_t ifp, mbuf_t m); |
197 | |
198 | /* |
199 | * gif_input is the input handler for IP and IPv6 attached to gif |
200 | */ |
201 | static errno_t |
202 | stf_media_input( |
203 | __unused ifnet_t ifp, |
204 | protocol_family_t protocol_family, |
205 | mbuf_t m, |
206 | __unused char *) |
207 | { |
208 | if (proto_input(protocol: protocol_family, packet: m) != 0) { |
209 | m_freem(m); |
210 | } |
211 | |
212 | return 0; |
213 | } |
214 | |
215 | |
216 | |
217 | static errno_t |
218 | stf_add_proto( |
219 | ifnet_t ifp, |
220 | protocol_family_t protocol_family, |
221 | __unused const struct ifnet_demux_desc *demux_array, |
222 | __unused u_int32_t demux_count) |
223 | { |
224 | /* Only one protocol may be attached at a time */ |
225 | struct stf_softc* stf = ifnet_softc(interface: ifp); |
226 | if (stf->sc_protocol_family == 0) { |
227 | stf->sc_protocol_family = protocol_family; |
228 | } else { |
229 | printf("stf_add_proto: stf already has a proto\n" ); |
230 | return EBUSY; |
231 | } |
232 | |
233 | return 0; |
234 | } |
235 | |
236 | static errno_t |
237 | stf_del_proto( |
238 | ifnet_t ifp, |
239 | protocol_family_t protocol_family) |
240 | { |
241 | if (((struct stf_softc*)ifnet_softc(interface: ifp))->sc_protocol_family == protocol_family) { |
242 | ((struct stf_softc*)ifnet_softc(interface: ifp))->sc_protocol_family = 0; |
243 | } |
244 | |
245 | return 0; |
246 | } |
247 | |
248 | static errno_t |
249 | stf_attach_inet6( |
250 | ifnet_t ifp, |
251 | protocol_family_t protocol_family) |
252 | { |
253 | struct ifnet_attach_proto_param reg; |
254 | errno_t stat; |
255 | |
256 | if (protocol_family != PF_INET6) { |
257 | return EPROTONOSUPPORT; |
258 | } |
259 | |
260 | bzero(s: ®, n: sizeof(reg)); |
261 | reg.input = stf_media_input; |
262 | reg.pre_output = stf_pre_output; |
263 | |
264 | stat = ifnet_attach_protocol(interface: ifp, protocol_family, proto_details: ®); |
265 | if (stat && stat != EEXIST) { |
266 | printf("stf_attach_proto_family can't attach interface fam=%d\n" , |
267 | protocol_family); |
268 | } |
269 | |
270 | return stat; |
271 | } |
272 | |
273 | static errno_t |
274 | stf_demux( |
275 | ifnet_t ifp, |
276 | __unused mbuf_t m, |
277 | __unused char *frame_ptr, |
278 | protocol_family_t *protocol_family) |
279 | { |
280 | struct stf_softc* stf = ifnet_softc(interface: ifp); |
281 | *protocol_family = stf->sc_protocol_family; |
282 | return 0; |
283 | } |
284 | |
285 | static errno_t |
286 | stf_set_bpf_tap( |
287 | ifnet_t ifp, |
288 | bpf_tap_mode mode, |
289 | bpf_packet_func callback) |
290 | { |
291 | struct stf_softc *sc = ifnet_softc(interface: ifp); |
292 | |
293 | sc->tap_mode = mode; |
294 | sc->tap_callback = callback; |
295 | |
296 | return 0; |
297 | } |
298 | |
299 | void |
300 | stfattach(void) |
301 | { |
302 | struct stf_softc *sc; |
303 | int error; |
304 | const struct encaptab *p; |
305 | struct ifnet_init_eparams stf_init; |
306 | |
307 | error = proto_register_plumber(PF_INET6, APPLE_IF_FAM_STF, |
308 | plumb: stf_attach_inet6, NULL); |
309 | if (error != 0) { |
310 | printf("proto_register_plumber failed for AF_INET6 error=%d\n" , error); |
311 | } |
312 | |
313 | sc = kalloc_type(struct stf_softc, Z_WAITOK_ZERO_NOFAIL); |
314 | lck_mtx_init(lck: &sc->sc_ro_mtx, grp: &stf_mtx_grp, LCK_ATTR_NULL); |
315 | |
316 | p = encap_attach_func(AF_INET, IPPROTO_IPV6, stf_encapcheck, |
317 | &in_stf_protosw, sc); |
318 | if (p == NULL) { |
319 | printf("sftattach encap_attach_func failed\n" ); |
320 | goto free_sc; |
321 | } |
322 | sc->encap_cookie = p; |
323 | |
324 | bzero(s: &stf_init, n: sizeof(stf_init)); |
325 | stf_init.ver = IFNET_INIT_CURRENT_VERSION; |
326 | stf_init.len = sizeof(stf_init); |
327 | stf_init.flags = IFNET_INIT_LEGACY; |
328 | stf_init.name = "stf" ; |
329 | stf_init.unit = 0; |
330 | stf_init.type = IFT_STF; |
331 | stf_init.family = IFNET_FAMILY_STF; |
332 | stf_init.output = stf_output; |
333 | stf_init.demux = stf_demux; |
334 | stf_init.add_proto = stf_add_proto; |
335 | stf_init.del_proto = stf_del_proto; |
336 | stf_init.softc = sc; |
337 | stf_init.ioctl = stf_ioctl; |
338 | stf_init.set_bpf_tap = stf_set_bpf_tap; |
339 | |
340 | error = ifnet_allocate_extended(init: &stf_init, interface: &sc->sc_if); |
341 | if (error != 0) { |
342 | printf("stfattach, ifnet_allocate failed - %d\n" , error); |
343 | encap_detach(sc->encap_cookie); |
344 | goto free_sc; |
345 | } |
346 | ifnet_set_mtu(interface: sc->sc_if, IPV6_MMTU); |
347 | ifnet_set_flags(interface: sc->sc_if, new_flags: 0, mask: 0xffff); /* clear all flags */ |
348 | #if 0 |
349 | /* turn off ingress filter */ |
350 | ifnet_set_flags(sc->sc_if, IFF_LINK2, IFF_LINK2); |
351 | #endif |
352 | |
353 | error = ifnet_attach(interface: sc->sc_if, NULL); |
354 | if (error != 0) { |
355 | printf("stfattach: ifnet_attach returned error=%d\n" , error); |
356 | encap_detach(sc->encap_cookie); |
357 | ifnet_release(interface: sc->sc_if); |
358 | goto free_sc; |
359 | } |
360 | |
361 | bpfattach(interface: sc->sc_if, DLT_NULL, header_length: sizeof(u_int)); |
362 | |
363 | return; |
364 | |
365 | free_sc: |
366 | lck_mtx_destroy(lck: &sc->sc_ro_mtx, grp: &stf_mtx_grp); |
367 | kfree_type(struct stf_softc, sc); |
368 | } |
369 | |
370 | static int |
371 | stf_encapcheck( |
372 | const struct mbuf *m, |
373 | __unused int off, |
374 | int proto, |
375 | void *arg) |
376 | { |
377 | struct ip ip; |
378 | struct in6_ifaddr *ia6; |
379 | struct stf_softc *sc; |
380 | struct in_addr a, b; |
381 | |
382 | sc = (struct stf_softc *)arg; |
383 | if (sc == NULL) { |
384 | return 0; |
385 | } |
386 | |
387 | if ((ifnet_flags(interface: sc->sc_if) & IFF_UP) == 0) { |
388 | return 0; |
389 | } |
390 | |
391 | /* IFF_LINK0 means "no decapsulation" */ |
392 | if ((ifnet_flags(interface: sc->sc_if) & IFF_LINK0) != 0) { |
393 | return 0; |
394 | } |
395 | |
396 | if (proto != IPPROTO_IPV6) { |
397 | return 0; |
398 | } |
399 | |
400 | mbuf_copydata(mbuf: (struct mbuf *)(size_t)m, offset: 0, length: sizeof(ip), out_data: &ip); |
401 | |
402 | if (ip.ip_v != 4) { |
403 | return 0; |
404 | } |
405 | |
406 | ia6 = stf_getsrcifa6(sc->sc_if); |
407 | if (ia6 == NULL) { |
408 | return 0; |
409 | } |
410 | |
411 | /* |
412 | * check if IPv4 dst matches the IPv4 address derived from the |
413 | * local 6to4 address. |
414 | * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... |
415 | */ |
416 | IFA_LOCK(&ia6->ia_ifa); |
417 | if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), s2: &ip.ip_dst, |
418 | n: sizeof(ip.ip_dst)) != 0) { |
419 | IFA_UNLOCK(&ia6->ia_ifa); |
420 | ifa_remref(ifa: &ia6->ia_ifa); |
421 | return 0; |
422 | } |
423 | /* |
424 | * check if IPv4 src matches the IPv4 address derived from the |
425 | * local 6to4 address masked by prefixmask. |
426 | * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 |
427 | * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 |
428 | */ |
429 | bzero(s: &a, n: sizeof(a)); |
430 | a.s_addr = GET_V4(&ia6->ia_addr.sin6_addr)->s_addr; |
431 | a.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; |
432 | b = ip.ip_src; |
433 | b.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; |
434 | if (a.s_addr != b.s_addr) { |
435 | IFA_UNLOCK(&ia6->ia_ifa); |
436 | ifa_remref(ifa: &ia6->ia_ifa); |
437 | return 0; |
438 | } |
439 | /* stf interface makes single side match only */ |
440 | IFA_UNLOCK(&ia6->ia_ifa); |
441 | ifa_remref(ifa: &ia6->ia_ifa); |
442 | return 32; |
443 | } |
444 | |
445 | static struct in6_ifaddr * |
446 | stf_getsrcifa6(struct ifnet *ifp) |
447 | { |
448 | struct ifaddr *ia; |
449 | struct in_ifaddr *ia4; |
450 | struct sockaddr_in6 *sin6; |
451 | struct in_addr in; |
452 | |
453 | ifnet_lock_shared(ifp); |
454 | for (ia = ifp->if_addrlist.tqh_first; ia; ia = ia->ifa_list.tqe_next) { |
455 | IFA_LOCK(ia); |
456 | if (ia->ifa_addr == NULL) { |
457 | IFA_UNLOCK(ia); |
458 | continue; |
459 | } |
460 | if (ia->ifa_addr->sa_family != AF_INET6) { |
461 | IFA_UNLOCK(ia); |
462 | continue; |
463 | } |
464 | sin6 = SIN6(ia->ifa_addr); |
465 | if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { |
466 | IFA_UNLOCK(ia); |
467 | continue; |
468 | } |
469 | bcopy(GET_V4(&sin6->sin6_addr), dst: &in, n: sizeof(in)); |
470 | IFA_UNLOCK(ia); |
471 | lck_rw_lock_shared(lck: &in_ifaddr_rwlock); |
472 | for (ia4 = TAILQ_FIRST(&in_ifaddrhead); |
473 | ia4; |
474 | ia4 = TAILQ_NEXT(ia4, ia_link)) { |
475 | IFA_LOCK(&ia4->ia_ifa); |
476 | if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) { |
477 | IFA_UNLOCK(&ia4->ia_ifa); |
478 | break; |
479 | } |
480 | IFA_UNLOCK(&ia4->ia_ifa); |
481 | } |
482 | lck_rw_done(lck: &in_ifaddr_rwlock); |
483 | if (ia4 == NULL) { |
484 | continue; |
485 | } |
486 | |
487 | ifa_addref(ifa: ia); /* for caller */ |
488 | ifnet_lock_done(ifp); |
489 | return (struct in6_ifaddr *)ia; |
490 | } |
491 | ifnet_lock_done(ifp); |
492 | |
493 | return NULL; |
494 | } |
495 | |
496 | int |
497 | stf_pre_output( |
498 | struct ifnet *ifp, |
499 | __unused protocol_family_t protocol_family, |
500 | struct mbuf **m0, |
501 | const struct sockaddr *dst, |
502 | __unused void *route, |
503 | __unused char *desk_linkaddr, |
504 | __unused char *frame_type) |
505 | { |
506 | struct mbuf *m = *m0; |
507 | struct stf_softc *sc; |
508 | const struct sockaddr_in6 *dst6; |
509 | const struct in_addr *in4; |
510 | u_int8_t tos; |
511 | struct ip *ip; |
512 | struct ip6_hdr *ip6; |
513 | struct in6_ifaddr *ia6; |
514 | struct sockaddr_in *dst4; |
515 | struct ip_out_args ipoa; |
516 | errno_t result = 0; |
517 | |
518 | bzero(s: &ipoa, n: sizeof(ipoa)); |
519 | ipoa.ipoa_boundif = IFSCOPE_NONE; |
520 | ipoa.ipoa_flags = IPOAF_SELECT_SRCIF; |
521 | ipoa.ipoa_sotc = SO_TC_UNSPEC; |
522 | ipoa.ipoa_netsvctype = _NET_SERVICE_TYPE_UNSPEC; |
523 | |
524 | sc = ifnet_softc(interface: ifp); |
525 | dst6 = SIN6(dst); |
526 | |
527 | /* just in case */ |
528 | if ((ifnet_flags(interface: ifp) & IFF_UP) == 0) { |
529 | printf("stf: IFF_DOWN\n" ); |
530 | return ENETDOWN; |
531 | } |
532 | |
533 | /* |
534 | * If we don't have an ip4 address that match my inner ip6 address, |
535 | * we shouldn't generate output. Without this check, we'll end up |
536 | * using wrong IPv4 source. |
537 | */ |
538 | ia6 = stf_getsrcifa6(ifp); |
539 | if (ia6 == NULL) { |
540 | return ENETDOWN; |
541 | } |
542 | |
543 | if (mbuf_len(mbuf: m) < sizeof(*ip6)) { |
544 | m = m_pullup(m, sizeof(*ip6)); |
545 | if (!m) { |
546 | *m0 = NULL; /* makes sure this won't be double freed */ |
547 | ifa_remref(ifa: &ia6->ia_ifa); |
548 | return ENOBUFS; |
549 | } |
550 | *m0 = m; |
551 | } |
552 | ip6 = mtod(m, struct ip6_hdr *); |
553 | tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; |
554 | |
555 | /* |
556 | * Pickup the right outer dst addr from the list of candidates. |
557 | * ip6_dst has priority as it may be able to give us shorter IPv4 hops. |
558 | */ |
559 | if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) { |
560 | in4 = GET_V4(&ip6->ip6_dst); |
561 | } else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) { |
562 | in4 = GET_V4(&dst6->sin6_addr); |
563 | } else { |
564 | ifa_remref(ifa: &ia6->ia_ifa); |
565 | return ENETUNREACH; |
566 | } |
567 | |
568 | if (ifp->if_bpf) { |
569 | /* We need to prepend the address family as a four byte field. */ |
570 | u_int32_t af = AF_INET6; |
571 | |
572 | bpf_tap_out(interface: ifp, dlt: 0, packet: m, header: &af, header_len: sizeof(af)); |
573 | } |
574 | |
575 | M_PREPEND(m, sizeof(struct ip), M_DONTWAIT, 1); |
576 | if (m && mbuf_len(mbuf: m) < sizeof(struct ip)) { |
577 | m = m_pullup(m, sizeof(struct ip)); |
578 | } |
579 | if (m == NULL) { |
580 | *m0 = NULL; |
581 | ifa_remref(ifa: &ia6->ia_ifa); |
582 | return ENOBUFS; |
583 | } |
584 | |
585 | *m0 = m; |
586 | ip = mtod(m, struct ip *); |
587 | |
588 | bzero(s: ip, n: sizeof(*ip)); |
589 | |
590 | IFA_LOCK_SPIN(&ia6->ia_ifa); |
591 | bcopy(GET_V4(&(SIN6(&ia6->ia_addr))->sin6_addr), |
592 | dst: &ip->ip_src, n: sizeof(ip->ip_src)); |
593 | IFA_UNLOCK(&ia6->ia_ifa); |
594 | bcopy(src: in4, dst: &ip->ip_dst, n: sizeof(ip->ip_dst)); |
595 | ip->ip_p = IPPROTO_IPV6; |
596 | ip->ip_ttl = ip_stf_ttl; |
597 | ip->ip_len = m->m_pkthdr.len; /*host order*/ |
598 | if (ifp->if_flags & IFF_LINK1) { |
599 | ip_ecn_ingress(ECN_NORMAL, &ip->ip_tos, &tos); |
600 | } else { |
601 | ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); |
602 | } |
603 | |
604 | lck_mtx_lock(lck: &sc->sc_ro_mtx); |
605 | dst4 = SIN(&sc->sc_ro.ro_dst); |
606 | if (ROUTE_UNUSABLE(&sc->sc_ro) || dst4->sin_family != AF_INET || |
607 | bcmp(s1: &dst4->sin_addr, s2: &ip->ip_dst, n: sizeof(ip->ip_dst)) != 0) { |
608 | ROUTE_RELEASE(&sc->sc_ro); |
609 | /* cache route doesn't match: always the case during the first use */ |
610 | dst4->sin_family = AF_INET; |
611 | dst4->sin_len = sizeof(struct sockaddr_in); |
612 | bcopy(src: &ip->ip_dst, dst: &dst4->sin_addr, n: sizeof(dst4->sin_addr)); |
613 | } |
614 | |
615 | result = ip_output(m, NULL, &sc->sc_ro, IP_OUTARGS, NULL, &ipoa); |
616 | lck_mtx_unlock(lck: &sc->sc_ro_mtx); |
617 | |
618 | /* Assumption: ip_output will free mbuf on errors */ |
619 | /* All the output processing is done here, don't let stf_output be called */ |
620 | if (result == 0) { |
621 | result = EJUSTRETURN; |
622 | } |
623 | *m0 = NULL; |
624 | ifa_remref(ifa: &ia6->ia_ifa); |
625 | return result; |
626 | } |
627 | static errno_t |
628 | stf_output( |
629 | __unused ifnet_t ifp, |
630 | __unused mbuf_t m) |
631 | { |
632 | /* All processing is done in stf_pre_output |
633 | * this shouldn't be called as the pre_output returns "EJUSTRETURN" |
634 | */ |
635 | return 0; |
636 | } |
637 | |
638 | static int |
639 | stf_checkaddr4( |
640 | struct stf_softc *sc, |
641 | const struct in_addr *in, |
642 | struct ifnet *inifp) /* incoming interface */ |
643 | { |
644 | struct in_ifaddr *ia4; |
645 | |
646 | /* |
647 | * reject packets with the following address: |
648 | * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 |
649 | */ |
650 | if (IN_MULTICAST(ntohl(in->s_addr))) { |
651 | return -1; |
652 | } |
653 | switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { |
654 | case 0: case 127: case 255: |
655 | return -1; |
656 | } |
657 | |
658 | /* |
659 | * reject packets with broadcast |
660 | */ |
661 | lck_rw_lock_shared(lck: &in_ifaddr_rwlock); |
662 | for (ia4 = TAILQ_FIRST(&in_ifaddrhead); |
663 | ia4; |
664 | ia4 = TAILQ_NEXT(ia4, ia_link)) { |
665 | IFA_LOCK(&ia4->ia_ifa); |
666 | if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) { |
667 | IFA_UNLOCK(&ia4->ia_ifa); |
668 | continue; |
669 | } |
670 | if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) { |
671 | IFA_UNLOCK(&ia4->ia_ifa); |
672 | lck_rw_done(lck: &in_ifaddr_rwlock); |
673 | return -1; |
674 | } |
675 | IFA_UNLOCK(&ia4->ia_ifa); |
676 | } |
677 | lck_rw_done(lck: &in_ifaddr_rwlock); |
678 | |
679 | /* |
680 | * perform ingress filter |
681 | */ |
682 | if (sc && (ifnet_flags(interface: sc->sc_if) & IFF_LINK2) == 0 && inifp) { |
683 | struct sockaddr_in sin; |
684 | struct rtentry *rt; |
685 | |
686 | SOCKADDR_ZERO(&sin, sizeof(sin)); |
687 | sin.sin_family = AF_INET; |
688 | sin.sin_len = sizeof(struct sockaddr_in); |
689 | sin.sin_addr = *in; |
690 | rt = rtalloc1(SA(&sin), 0, 0); |
691 | if (rt != NULL) { |
692 | RT_LOCK(rt); |
693 | } |
694 | if (rt == NULL || rt->rt_ifp != inifp) { |
695 | #if 1 |
696 | log(LOG_WARNING, "%s: packet from 0x%x dropped " |
697 | "due to ingress filter\n" , if_name(sc->sc_if), |
698 | (u_int32_t)ntohl(sin.sin_addr.s_addr)); |
699 | #endif |
700 | if (rt != NULL) { |
701 | RT_UNLOCK(rt); |
702 | rtfree(rt); |
703 | } |
704 | return -1; |
705 | } |
706 | RT_UNLOCK(rt); |
707 | rtfree(rt); |
708 | } |
709 | |
710 | return 0; |
711 | } |
712 | |
713 | static int |
714 | stf_checkaddr6( |
715 | struct stf_softc *sc, |
716 | struct in6_addr *in6, |
717 | struct ifnet *inifp) /* incoming interface */ |
718 | { |
719 | /* |
720 | * check 6to4 addresses |
721 | */ |
722 | if (IN6_IS_ADDR_6TO4(in6)) { |
723 | return stf_checkaddr4(sc, GET_V4(in6), inifp); |
724 | } |
725 | |
726 | /* |
727 | * reject anything that look suspicious. the test is implemented |
728 | * in ip6_input too, but we check here as well to |
729 | * (1) reject bad packets earlier, and |
730 | * (2) to be safe against future ip6_input change. |
731 | */ |
732 | if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) { |
733 | return -1; |
734 | } |
735 | |
736 | return 0; |
737 | } |
738 | |
739 | static void |
740 | in_stf_input( |
741 | struct mbuf *m, |
742 | int off) |
743 | { |
744 | struct stf_softc *sc; |
745 | struct ip *ip; |
746 | struct ip6_hdr ip6; |
747 | u_int8_t otos, itos; |
748 | int proto; |
749 | struct ifnet *ifp; |
750 | struct ifnet_stat_increment_param stats; |
751 | |
752 | ip = mtod(m, struct ip *); |
753 | proto = ip->ip_p; |
754 | |
755 | if (proto != IPPROTO_IPV6) { |
756 | m_freem(m); |
757 | return; |
758 | } |
759 | |
760 | ip = mtod(m, struct ip *); |
761 | |
762 | sc = (struct stf_softc *)encap_getarg(m); |
763 | |
764 | if (sc == NULL || (ifnet_flags(interface: sc->sc_if) & IFF_UP) == 0) { |
765 | m_freem(m); |
766 | return; |
767 | } |
768 | |
769 | ifp = sc->sc_if; |
770 | |
771 | /* |
772 | * perform sanity check against outer src/dst. |
773 | * for source, perform ingress filter as well. |
774 | */ |
775 | if (stf_checkaddr4(sc, in: &ip->ip_dst, NULL) < 0 || |
776 | stf_checkaddr4(sc, in: &ip->ip_src, inifp: m->m_pkthdr.rcvif) < 0) { |
777 | m_freem(m); |
778 | return; |
779 | } |
780 | |
781 | otos = ip->ip_tos; |
782 | if (mbuf_copydata(mbuf: m, offset: off, length: sizeof(ip6), out_data: &ip6)) { |
783 | m_freem(m); |
784 | return; |
785 | } |
786 | |
787 | /* |
788 | * perform sanity check against inner src/dst. |
789 | * for source, perform ingress filter as well. |
790 | */ |
791 | if (stf_checkaddr6(sc, in6: &ip6.ip6_dst, NULL) < 0 || |
792 | stf_checkaddr6(sc, in6: &ip6.ip6_src, inifp: m->m_pkthdr.rcvif) < 0) { |
793 | m_freem(m); |
794 | return; |
795 | } |
796 | |
797 | itos = (ntohl(ip6.ip6_flow) >> 20) & 0xff; |
798 | if ((ifnet_flags(interface: ifp) & IFF_LINK1) != 0) { |
799 | ip_ecn_egress(ECN_NORMAL, &otos, &itos); |
800 | } else { |
801 | ip_ecn_egress(ECN_NOCARE, &otos, &itos); |
802 | } |
803 | ip6.ip6_flow &= ~htonl(0xff << 20); |
804 | ip6.ip6_flow |= htonl((u_int32_t)itos << 20); |
805 | |
806 | m->m_pkthdr.rcvif = ifp; |
807 | mbuf_pkthdr_setheader(mbuf: m, header: mbuf_data(mbuf: m)); |
808 | mbuf_adj(mbuf: m, len: off); |
809 | |
810 | if (ifp->if_bpf) { |
811 | /* We need to prepend the address family as a four byte field. */ |
812 | u_int32_t af = AF_INET6; |
813 | bpf_tap_in(interface: ifp, dlt: 0, packet: m, header: &af, header_len: sizeof(af)); |
814 | } |
815 | |
816 | /* |
817 | * Put the packet to the network layer input queue according to the |
818 | * specified address family. |
819 | * See net/if_gif.c for possible issues with packet processing |
820 | * reorder due to extra queueing. |
821 | */ |
822 | bzero(s: &stats, n: sizeof(stats)); |
823 | stats.packets_in = 1; |
824 | stats.bytes_in = mbuf_pkthdr_len(mbuf: m); |
825 | mbuf_pkthdr_setrcvif(mbuf: m, ifp); |
826 | ifnet_input(interface: ifp, first_packet: m, stats: &stats); |
827 | |
828 | return; |
829 | } |
830 | |
831 | static void |
832 | stf_rtrequest( |
833 | __unused int cmd, |
834 | struct rtentry *rt, |
835 | __unused struct sockaddr *sa) |
836 | { |
837 | if (rt != NULL) { |
838 | RT_LOCK_ASSERT_HELD(rt); |
839 | rt->rt_rmx.rmx_mtu = IPV6_MMTU; |
840 | } |
841 | } |
842 | |
843 | static errno_t |
844 | stf_ioctl( |
845 | ifnet_t ifp, |
846 | u_long cmd, |
847 | void *data) |
848 | { |
849 | struct ifaddr *ifa; |
850 | struct ifreq *ifr; |
851 | struct sockaddr_in6 *sin6; |
852 | int error; |
853 | |
854 | error = 0; |
855 | switch (cmd) { |
856 | case SIOCSIFADDR: |
857 | ifa = (struct ifaddr *)data; |
858 | if (ifa == NULL) { |
859 | error = EAFNOSUPPORT; |
860 | break; |
861 | } |
862 | IFA_LOCK(ifa); |
863 | if (ifa->ifa_addr->sa_family != AF_INET6) { |
864 | IFA_UNLOCK(ifa); |
865 | error = EAFNOSUPPORT; |
866 | break; |
867 | } |
868 | sin6 = SIN6(ifa->ifa_addr); |
869 | if (IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { |
870 | if (!(ifnet_flags( interface: ifp ) & IFF_UP)) { |
871 | /* do this only if the interface is not already up */ |
872 | ifa->ifa_rtrequest = stf_rtrequest; |
873 | IFA_UNLOCK(ifa); |
874 | ifnet_set_flags(interface: ifp, IFF_UP, IFF_UP); |
875 | } else { |
876 | IFA_UNLOCK(ifa); |
877 | } |
878 | } else { |
879 | IFA_UNLOCK(ifa); |
880 | error = EINVAL; |
881 | } |
882 | IFA_LOCK_ASSERT_NOTHELD(ifa); |
883 | break; |
884 | |
885 | case SIOCADDMULTI: |
886 | case SIOCDELMULTI: |
887 | ifr = (struct ifreq *)data; |
888 | if (ifr && ifr->ifr_addr.sa_family == AF_INET6) { |
889 | ; |
890 | } else { |
891 | error = EAFNOSUPPORT; |
892 | } |
893 | break; |
894 | |
895 | default: |
896 | error = EOPNOTSUPP; |
897 | break; |
898 | } |
899 | |
900 | return error; |
901 | } |
902 | |