1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $
32 */
33
34 /*-
35 * Copyright (c) 1982, 1986, 1988, 1993
36 * The Regents of the University of California. All rights reserved.
37 *
38 * Redistribution and use in source and binary forms, with or without
39 * modification, are permitted provided that the following conditions
40 * are met:
41 * 1. Redistributions of source code must retain the above copyright
42 * notice, this list of conditions and the following disclaimer.
43 * 2. Redistributions in binary form must reproduce the above copyright
44 * notice, this list of conditions and the following disclaimer in the
45 * documentation and/or other materials provided with the distribution.
46 * 3. Neither the name of the University nor the names of its contributors
47 * may be used to endorse or promote products derived from this software
48 * without specific prior written permission.
49 *
50 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60 * SUCH DAMAGE.
61 *
62 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94
63 */
64
65 #include <sys/cdefs.h>
66 __FBSDID("$FreeBSD$");
67
68 #define MBUF_PRIVATE /* XXXRW: Optimisation tries to avoid M_EXT mbufs */
69
70 #include "opt_inet.h"
71 #include "opt_inet6.h"
72
73 #include <sys/param.h>
74 #include <sys/domain.h>
75 #include <sys/jail.h>
76 #include <sys/kernel.h>
77 #include <sys/lock.h>
78 #include <sys/malloc.h>
79 #include <sys/mbuf.h>
80 #include <sys/proc.h>
81 #include <sys/protosw.h>
82 #include <sys/signalvar.h>
83 #include <sys/socket.h>
84 #include <sys/socketvar.h>
85 #include <sys/sx.h>
86 #include <sys/syslog.h>
87 #include <sys/systm.h>
88 #include <sys/time.h>
89
90 #include <net/if.h>
91 #include <net/if_var.h>
92 #include <net/if_dl.h>
93 #include <net/if_llatbl.h>
94 #include <net/if_types.h>
95 #include <net/route.h>
96 #include <net/vnet.h>
97
98 #include <netinet/in.h>
99 #include <netinet/in_pcb.h>
100 #include <netinet/in_var.h>
101 #include <netinet/ip6.h>
102 #include <netinet/icmp6.h>
103 #include <netinet/tcp_var.h>
104
105 #include <netinet6/in6_fib.h>
106 #include <netinet6/in6_ifattach.h>
107 #include <netinet6/in6_pcb.h>
108 #include <netinet6/ip6protosw.h>
109 #include <netinet6/ip6_var.h>
110 #include <netinet6/scope6_var.h>
111 #include <netinet6/mld6_var.h>
112 #include <netinet6/nd6.h>
113 #include <netinet6/send.h>
114
115 extern struct domain inet6domain;
116
117 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat);
118 VNET_PCPUSTAT_SYSINIT(icmp6stat);
119
120 #ifdef VIMAGE
121 VNET_PCPUSTAT_SYSUNINIT(icmp6stat);
122 #endif /* VIMAGE */
123
124 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
125 VNET_DECLARE(struct inpcbhead, ripcb);
126 VNET_DECLARE(int, icmp6errppslim);
127 VNET_DEFINE_STATIC(int, icmp6errpps_count) = 0;
128 VNET_DEFINE_STATIC(struct timeval, icmp6errppslim_last);
129 VNET_DECLARE(int, icmp6_nodeinfo);
130
131 #define V_ripcbinfo VNET(ripcbinfo)
132 #define V_ripcb VNET(ripcb)
133 #define V_icmp6errppslim VNET(icmp6errppslim)
134 #define V_icmp6errpps_count VNET(icmp6errpps_count)
135 #define V_icmp6errppslim_last VNET(icmp6errppslim_last)
136 #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo)
137
138 static void icmp6_errcount(int, int);
139 static int icmp6_rip6_input(struct mbuf **, int);
140 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
141 static const char *icmp6_redirect_diag(struct in6_addr *,
142 struct in6_addr *, struct in6_addr *);
143 static struct mbuf *ni6_input(struct mbuf *, int);
144 static struct mbuf *ni6_nametodns(const char *, int, int);
145 static int ni6_dnsmatch(const char *, int, const char *, int);
146 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *,
147 struct ifnet **, struct in6_addr *);
148 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
149 struct ifnet *, int);
150 static int icmp6_notify_error(struct mbuf **, int, int, int);
151
152 /*
153 * Kernel module interface for updating icmp6stat. The argument is an index
154 * into icmp6stat treated as an array of u_quad_t. While this encodes the
155 * general layout of icmp6stat into the caller, it doesn't encode its
156 * location, so that future changes to add, for example, per-CPU stats
157 * support won't cause binary compatibility problems for kernel modules.
158 */
159 void
kmod_icmp6stat_inc(int statnum)160 kmod_icmp6stat_inc(int statnum)
161 {
162
163 counter_u64_add(VNET(icmp6stat)[statnum], 1);
164 }
165
166 static void
icmp6_errcount(int type,int code)167 icmp6_errcount(int type, int code)
168 {
169 switch (type) {
170 case ICMP6_DST_UNREACH:
171 switch (code) {
172 case ICMP6_DST_UNREACH_NOROUTE:
173 ICMP6STAT_INC(icp6s_odst_unreach_noroute);
174 return;
175 case ICMP6_DST_UNREACH_ADMIN:
176 ICMP6STAT_INC(icp6s_odst_unreach_admin);
177 return;
178 case ICMP6_DST_UNREACH_BEYONDSCOPE:
179 ICMP6STAT_INC(icp6s_odst_unreach_beyondscope);
180 return;
181 case ICMP6_DST_UNREACH_ADDR:
182 ICMP6STAT_INC(icp6s_odst_unreach_addr);
183 return;
184 case ICMP6_DST_UNREACH_NOPORT:
185 ICMP6STAT_INC(icp6s_odst_unreach_noport);
186 return;
187 }
188 break;
189 case ICMP6_PACKET_TOO_BIG:
190 ICMP6STAT_INC(icp6s_opacket_too_big);
191 return;
192 case ICMP6_TIME_EXCEEDED:
193 switch (code) {
194 case ICMP6_TIME_EXCEED_TRANSIT:
195 ICMP6STAT_INC(icp6s_otime_exceed_transit);
196 return;
197 case ICMP6_TIME_EXCEED_REASSEMBLY:
198 ICMP6STAT_INC(icp6s_otime_exceed_reassembly);
199 return;
200 }
201 break;
202 case ICMP6_PARAM_PROB:
203 switch (code) {
204 case ICMP6_PARAMPROB_HEADER:
205 ICMP6STAT_INC(icp6s_oparamprob_header);
206 return;
207 case ICMP6_PARAMPROB_NEXTHEADER:
208 ICMP6STAT_INC(icp6s_oparamprob_nextheader);
209 return;
210 case ICMP6_PARAMPROB_OPTION:
211 ICMP6STAT_INC(icp6s_oparamprob_option);
212 return;
213 }
214 break;
215 case ND_REDIRECT:
216 ICMP6STAT_INC(icp6s_oredirect);
217 return;
218 }
219 ICMP6STAT_INC(icp6s_ounknown);
220 }
221
222 /*
223 * A wrapper function for icmp6_error() necessary when the erroneous packet
224 * may not contain enough scope zone information.
225 */
226 void
icmp6_error2(struct mbuf * m,int type,int code,int param,struct ifnet * ifp)227 icmp6_error2(struct mbuf *m, int type, int code, int param,
228 struct ifnet *ifp)
229 {
230 struct ip6_hdr *ip6;
231
232 if (ifp == NULL)
233 return;
234
235 #ifndef PULLDOWN_TEST
236 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
237 #else
238 if (m->m_len < sizeof(struct ip6_hdr)) {
239 m = m_pullup(m, sizeof(struct ip6_hdr));
240 if (m == NULL)
241 return;
242 }
243 #endif
244
245 ip6 = mtod(m, struct ip6_hdr *);
246
247 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
248 return;
249 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
250 return;
251
252 icmp6_error(m, type, code, param);
253 }
254
255 /*
256 * Generate an error packet of type error in response to bad IP6 packet.
257 */
258 void
icmp6_error(struct mbuf * m,int type,int code,int param)259 icmp6_error(struct mbuf *m, int type, int code, int param)
260 {
261 struct ip6_hdr *oip6, *nip6;
262 struct icmp6_hdr *icmp6;
263 u_int preplen;
264 int off;
265 int nxt;
266
267 ICMP6STAT_INC(icp6s_error);
268
269 /* count per-type-code statistics */
270 icmp6_errcount(type, code);
271
272 #ifdef M_DECRYPTED /*not openbsd*/
273 if (m->m_flags & M_DECRYPTED) {
274 ICMP6STAT_INC(icp6s_canterror);
275 goto freeit;
276 }
277 #endif
278
279 #ifndef PULLDOWN_TEST
280 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
281 #else
282 if (m->m_len < sizeof(struct ip6_hdr)) {
283 m = m_pullup(m, sizeof(struct ip6_hdr));
284 if (m == NULL)
285 return;
286 }
287 #endif
288 oip6 = mtod(m, struct ip6_hdr *);
289
290 /*
291 * If the destination address of the erroneous packet is a multicast
292 * address, or the packet was sent using link-layer multicast,
293 * we should basically suppress sending an error (RFC 2463, Section
294 * 2.4).
295 * We have two exceptions (the item e.2 in that section):
296 * - the Packet Too Big message can be sent for path MTU discovery.
297 * - the Parameter Problem Message that can be allowed an icmp6 error
298 * in the option type field. This check has been done in
299 * ip6_unknown_opt(), so we can just check the type and code.
300 */
301 if ((m->m_flags & (M_BCAST|M_MCAST) ||
302 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
303 (type != ICMP6_PACKET_TOO_BIG &&
304 (type != ICMP6_PARAM_PROB ||
305 code != ICMP6_PARAMPROB_OPTION)))
306 goto freeit;
307
308 /*
309 * RFC 2463, 2.4 (e.5): source address check.
310 * XXX: the case of anycast source?
311 */
312 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
313 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
314 goto freeit;
315
316 /*
317 * If we are about to send ICMPv6 against ICMPv6 error/redirect,
318 * don't do it.
319 */
320 nxt = -1;
321 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
322 if (off >= 0 && nxt == IPPROTO_ICMPV6) {
323 struct icmp6_hdr *icp;
324
325 #ifndef PULLDOWN_TEST
326 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
327 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
328 #else
329 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
330 sizeof(*icp));
331 if (icp == NULL) {
332 ICMP6STAT_INC(icp6s_tooshort);
333 return;
334 }
335 #endif
336 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
337 icp->icmp6_type == ND_REDIRECT) {
338 /*
339 * ICMPv6 error
340 * Special case: for redirect (which is
341 * informational) we must not send icmp6 error.
342 */
343 ICMP6STAT_INC(icp6s_canterror);
344 goto freeit;
345 } else {
346 /* ICMPv6 informational - send the error */
347 }
348 } else {
349 /* non-ICMPv6 - send the error */
350 }
351
352 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
353
354 /* Finally, do rate limitation check. */
355 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
356 ICMP6STAT_INC(icp6s_toofreq);
357 goto freeit;
358 }
359
360 /*
361 * OK, ICMP6 can be generated.
362 */
363
364 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
365 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
366
367 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
368 M_PREPEND(m, preplen, M_NOWAIT); /* FIB is also copied over. */
369 if (m == NULL) {
370 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
371 return;
372 }
373
374 nip6 = mtod(m, struct ip6_hdr *);
375 nip6->ip6_src = oip6->ip6_src;
376 nip6->ip6_dst = oip6->ip6_dst;
377
378 in6_clearscope(&oip6->ip6_src);
379 in6_clearscope(&oip6->ip6_dst);
380
381 icmp6 = (struct icmp6_hdr *)(nip6 + 1);
382 icmp6->icmp6_type = type;
383 icmp6->icmp6_code = code;
384 icmp6->icmp6_pptr = htonl((u_int32_t)param);
385
386 ICMP6STAT_INC(icp6s_outhist[type]);
387 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
388
389 return;
390
391 freeit:
392 /*
393 * If we can't tell whether or not we can generate ICMP6, free it.
394 */
395 m_freem(m);
396 }
397
398 /*
399 * Process a received ICMP6 message.
400 */
401 int
icmp6_input(struct mbuf ** mp,int * offp,int proto)402 icmp6_input(struct mbuf **mp, int *offp, int proto)
403 {
404 struct mbuf *m = *mp, *n;
405 struct ifnet *ifp;
406 struct ip6_hdr *ip6, *nip6;
407 struct icmp6_hdr *icmp6, *nicmp6;
408 int off = *offp;
409 int icmp6len = m->m_pkthdr.len - *offp;
410 int code, sum, noff;
411 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
412 int ip6len, error;
413
414 ifp = m->m_pkthdr.rcvif;
415
416 #ifndef PULLDOWN_TEST
417 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
418 /* m might change if M_LOOP. So, call mtod after this */
419 #endif
420
421 /*
422 * Locate icmp6 structure in mbuf, and check
423 * that not corrupted and of at least minimum length
424 */
425
426 ip6 = mtod(m, struct ip6_hdr *);
427 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
428 if (icmp6len < sizeof(struct icmp6_hdr)) {
429 ICMP6STAT_INC(icp6s_tooshort);
430 goto freeit;
431 }
432
433 /*
434 * Check multicast group membership.
435 * Note: SSM filters are not applied for ICMPv6 traffic.
436 */
437 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
438 struct in6_multi *inm;
439
440 inm = in6m_lookup(ifp, &ip6->ip6_dst);
441 if (inm == NULL) {
442 IP6STAT_INC(ip6s_notmember);
443 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
444 goto freeit;
445 }
446 }
447
448 /*
449 * calculate the checksum
450 */
451 #ifndef PULLDOWN_TEST
452 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
453 #else
454 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
455 if (icmp6 == NULL) {
456 ICMP6STAT_INC(icp6s_tooshort);
457 return IPPROTO_DONE;
458 }
459 #endif
460 code = icmp6->icmp6_code;
461
462 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
463 nd6log((LOG_ERR,
464 "ICMP6 checksum error(%d|%x) %s\n",
465 icmp6->icmp6_type, sum,
466 ip6_sprintf(ip6bufs, &ip6->ip6_src)));
467 ICMP6STAT_INC(icp6s_checksum);
468 goto freeit;
469 }
470
471 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
472 icmp6_ifstat_inc(ifp, ifs6_in_msg);
473 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
474 icmp6_ifstat_inc(ifp, ifs6_in_error);
475
476 switch (icmp6->icmp6_type) {
477 case ICMP6_DST_UNREACH:
478 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
479 switch (code) {
480 case ICMP6_DST_UNREACH_NOROUTE:
481 case ICMP6_DST_UNREACH_ADDR: /* PRC_HOSTDEAD is a DOS */
482 code = PRC_UNREACH_NET;
483 break;
484 case ICMP6_DST_UNREACH_ADMIN:
485 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
486 code = PRC_UNREACH_ADMIN_PROHIB;
487 break;
488 case ICMP6_DST_UNREACH_BEYONDSCOPE:
489 /* I mean "source address was incorrect." */
490 code = PRC_PARAMPROB;
491 break;
492 case ICMP6_DST_UNREACH_NOPORT:
493 code = PRC_UNREACH_PORT;
494 break;
495 default:
496 goto badcode;
497 }
498 goto deliver;
499 break;
500
501 case ICMP6_PACKET_TOO_BIG:
502 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
503
504 /* validation is made in icmp6_mtudisc_update */
505
506 code = PRC_MSGSIZE;
507
508 /*
509 * Updating the path MTU will be done after examining
510 * intermediate extension headers.
511 */
512 goto deliver;
513 break;
514
515 case ICMP6_TIME_EXCEEDED:
516 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
517 switch (code) {
518 case ICMP6_TIME_EXCEED_TRANSIT:
519 code = PRC_TIMXCEED_INTRANS;
520 break;
521 case ICMP6_TIME_EXCEED_REASSEMBLY:
522 code = PRC_TIMXCEED_REASS;
523 break;
524 default:
525 goto badcode;
526 }
527 goto deliver;
528 break;
529
530 case ICMP6_PARAM_PROB:
531 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
532 switch (code) {
533 case ICMP6_PARAMPROB_NEXTHEADER:
534 code = PRC_UNREACH_PROTOCOL;
535 break;
536 case ICMP6_PARAMPROB_HEADER:
537 case ICMP6_PARAMPROB_OPTION:
538 code = PRC_PARAMPROB;
539 break;
540 default:
541 goto badcode;
542 }
543 goto deliver;
544 break;
545
546 case ICMP6_ECHO_REQUEST:
547 icmp6_ifstat_inc(ifp, ifs6_in_echo);
548 if (code != 0)
549 goto badcode;
550 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
551 /* Give up remote */
552 break;
553 }
554 if (!M_WRITABLE(n)
555 || n->m_len < off + sizeof(struct icmp6_hdr)) {
556 struct mbuf *n0 = n;
557 int n0len;
558
559 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN);
560 n = m_gethdr(M_NOWAIT, n0->m_type);
561 if (n == NULL) {
562 /* Give up remote */
563 m_freem(n0);
564 break;
565 }
566
567 m_move_pkthdr(n, n0); /* FIB copied. */
568 n0len = n0->m_pkthdr.len; /* save for use below */
569 /*
570 * Copy IPv6 and ICMPv6 only.
571 */
572 nip6 = mtod(n, struct ip6_hdr *);
573 bcopy(ip6, nip6, sizeof(struct ip6_hdr));
574 nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
575 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
576 noff = sizeof(struct ip6_hdr);
577 /* new mbuf contains only ipv6+icmpv6 headers */
578 n->m_len = noff + sizeof(struct icmp6_hdr);
579 /*
580 * Adjust mbuf. ip6_plen will be adjusted in
581 * ip6_output().
582 */
583 m_adj(n0, off + sizeof(struct icmp6_hdr));
584 /* recalculate complete packet size */
585 n->m_pkthdr.len = n0len + (noff - off);
586 n->m_next = n0;
587 } else {
588 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
589 sizeof(*nicmp6));
590 noff = off;
591 }
592 if (n) {
593 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
594 nicmp6->icmp6_code = 0;
595 ICMP6STAT_INC(icp6s_reflect);
596 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
597 icmp6_reflect(n, noff);
598 }
599 break;
600
601 case ICMP6_ECHO_REPLY:
602 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
603 if (code != 0)
604 goto badcode;
605 break;
606
607 case MLD_LISTENER_QUERY:
608 case MLD_LISTENER_REPORT:
609 case MLD_LISTENER_DONE:
610 case MLDV2_LISTENER_REPORT:
611 /*
612 * Drop MLD traffic which is not link-local, has a hop limit
613 * of greater than 1 hop, or which does not have the
614 * IPv6 HBH Router Alert option.
615 * As IPv6 HBH options are stripped in ip6_input() we must
616 * check an mbuf header flag.
617 * XXX Should we also sanity check that these messages
618 * were directed to a link-local multicast prefix?
619 */
620 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
621 goto freeit;
622 if (mld_input(m, off, icmp6len) != 0)
623 return (IPPROTO_DONE);
624 /* m stays. */
625 break;
626
627 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */
628 {
629 enum { WRU, FQDN } mode;
630
631 if (!V_icmp6_nodeinfo)
632 break;
633
634 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
635 mode = WRU;
636 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
637 mode = FQDN;
638 else
639 goto badlen;
640
641 if (mode == FQDN) {
642 #ifndef PULLDOWN_TEST
643 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
644 IPPROTO_DONE);
645 #endif
646 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
647 if (n)
648 n = ni6_input(n, off);
649 /* XXX meaningless if n == NULL */
650 noff = sizeof(struct ip6_hdr);
651 } else {
652 struct prison *pr;
653 u_char *p;
654 int maxhlen, hlen;
655
656 /*
657 * XXX: this combination of flags is pointless,
658 * but should we keep this for compatibility?
659 */
660 if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK |
661 ICMP6_NODEINFO_TMPADDROK)) !=
662 (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK))
663 break;
664
665 if (code != 0)
666 goto badcode;
667
668 CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN);
669 n = m_gethdr(M_NOWAIT, m->m_type);
670 if (n == NULL) {
671 /* Give up remote */
672 break;
673 }
674 if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
675 /*
676 * Previous code did a blind M_COPY_PKTHDR
677 * and said "just for rcvif". If true, then
678 * we could tolerate the dup failing (due to
679 * the deep copy of the tag chain). For now
680 * be conservative and just fail.
681 */
682 m_free(n);
683 n = NULL;
684 break;
685 }
686 maxhlen = M_TRAILINGSPACE(n) -
687 (sizeof(*nip6) + sizeof(*nicmp6) + 4);
688 pr = curthread->td_ucred->cr_prison;
689 mtx_lock(&pr->pr_mtx);
690 hlen = strlen(pr->pr_hostname);
691 if (maxhlen > hlen)
692 maxhlen = hlen;
693 /*
694 * Copy IPv6 and ICMPv6 only.
695 */
696 nip6 = mtod(n, struct ip6_hdr *);
697 bcopy(ip6, nip6, sizeof(struct ip6_hdr));
698 nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
699 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
700 p = (u_char *)(nicmp6 + 1);
701 bzero(p, 4);
702 /* meaningless TTL */
703 bcopy(pr->pr_hostname, p + 4, maxhlen);
704 mtx_unlock(&pr->pr_mtx);
705 noff = sizeof(struct ip6_hdr);
706 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
707 sizeof(struct icmp6_hdr) + 4 + maxhlen;
708 nicmp6->icmp6_type = ICMP6_WRUREPLY;
709 nicmp6->icmp6_code = 0;
710 }
711 if (n) {
712 ICMP6STAT_INC(icp6s_reflect);
713 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
714 icmp6_reflect(n, noff);
715 }
716 break;
717 }
718
719 case ICMP6_WRUREPLY:
720 if (code != 0)
721 goto badcode;
722 break;
723
724 case ND_ROUTER_SOLICIT:
725 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
726 if (code != 0)
727 goto badcode;
728 if (icmp6len < sizeof(struct nd_router_solicit))
729 goto badlen;
730 if (send_sendso_input_hook != NULL) {
731 IP6_EXTHDR_CHECK(m, off, icmp6len, IPPROTO_DONE);
732 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
733 if (error == 0) {
734 m = NULL;
735 goto freeit;
736 }
737 }
738 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
739 nd6_rs_input(m, off, icmp6len);
740 m = n;
741 if (m == NULL)
742 goto freeit;
743 break;
744
745 case ND_ROUTER_ADVERT:
746 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
747 if (code != 0)
748 goto badcode;
749 if (icmp6len < sizeof(struct nd_router_advert))
750 goto badlen;
751 if (send_sendso_input_hook != NULL) {
752 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
753 if (error == 0) {
754 m = NULL;
755 goto freeit;
756 }
757 }
758 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
759 nd6_ra_input(m, off, icmp6len);
760 m = n;
761 if (m == NULL)
762 goto freeit;
763 break;
764
765 case ND_NEIGHBOR_SOLICIT:
766 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
767 if (code != 0)
768 goto badcode;
769 if (icmp6len < sizeof(struct nd_neighbor_solicit))
770 goto badlen;
771 if (send_sendso_input_hook != NULL) {
772 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
773 if (error == 0) {
774 m = NULL;
775 goto freeit;
776 }
777 }
778 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
779 nd6_ns_input(m, off, icmp6len);
780 m = n;
781 if (m == NULL)
782 goto freeit;
783 break;
784
785 case ND_NEIGHBOR_ADVERT:
786 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
787 if (code != 0)
788 goto badcode;
789 if (icmp6len < sizeof(struct nd_neighbor_advert))
790 goto badlen;
791 if (send_sendso_input_hook != NULL) {
792 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
793 if (error == 0) {
794 m = NULL;
795 goto freeit;
796 }
797 }
798 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
799 nd6_na_input(m, off, icmp6len);
800 m = n;
801 if (m == NULL)
802 goto freeit;
803 break;
804
805 case ND_REDIRECT:
806 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
807 if (code != 0)
808 goto badcode;
809 if (icmp6len < sizeof(struct nd_redirect))
810 goto badlen;
811 if (send_sendso_input_hook != NULL) {
812 error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
813 if (error == 0) {
814 m = NULL;
815 goto freeit;
816 }
817 }
818 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
819 icmp6_redirect_input(m, off);
820 m = n;
821 if (m == NULL)
822 goto freeit;
823 break;
824
825 case ICMP6_ROUTER_RENUMBERING:
826 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
827 code != ICMP6_ROUTER_RENUMBERING_RESULT)
828 goto badcode;
829 if (icmp6len < sizeof(struct icmp6_router_renum))
830 goto badlen;
831 break;
832
833 default:
834 nd6log((LOG_DEBUG,
835 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
836 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
837 ip6_sprintf(ip6bufd, &ip6->ip6_dst),
838 ifp ? ifp->if_index : 0));
839 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
840 /* ICMPv6 error: MUST deliver it by spec... */
841 code = PRC_NCMDS;
842 /* deliver */
843 } else {
844 /* ICMPv6 informational: MUST not deliver */
845 break;
846 }
847 deliver:
848 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
849 /* In this case, m should've been freed. */
850 return (IPPROTO_DONE);
851 }
852 break;
853
854 badcode:
855 ICMP6STAT_INC(icp6s_badcode);
856 break;
857
858 badlen:
859 ICMP6STAT_INC(icp6s_badlen);
860 break;
861 }
862
863 /* deliver the packet to appropriate sockets */
864 icmp6_rip6_input(&m, *offp);
865
866 return IPPROTO_DONE;
867
868 freeit:
869 m_freem(m);
870 return IPPROTO_DONE;
871 }
872
873 static int
icmp6_notify_error(struct mbuf ** mp,int off,int icmp6len,int code)874 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
875 {
876 struct mbuf *m = *mp;
877 struct icmp6_hdr *icmp6;
878 struct ip6_hdr *eip6;
879 u_int32_t notifymtu;
880 struct sockaddr_in6 icmp6src, icmp6dst;
881
882 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
883 ICMP6STAT_INC(icp6s_tooshort);
884 goto freeit;
885 }
886 #ifndef PULLDOWN_TEST
887 IP6_EXTHDR_CHECK(m, off,
888 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
889 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
890 #else
891 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
892 sizeof(*icmp6) + sizeof(struct ip6_hdr));
893 if (icmp6 == NULL) {
894 ICMP6STAT_INC(icp6s_tooshort);
895 return (-1);
896 }
897 #endif
898 eip6 = (struct ip6_hdr *)(icmp6 + 1);
899 bzero(&icmp6dst, sizeof(icmp6dst));
900
901 /* Detect the upper level protocol */
902 {
903 void (*ctlfunc)(int, struct sockaddr *, void *);
904 u_int8_t nxt = eip6->ip6_nxt;
905 int eoff = off + sizeof(struct icmp6_hdr) +
906 sizeof(struct ip6_hdr);
907 struct ip6ctlparam ip6cp;
908 int icmp6type = icmp6->icmp6_type;
909 struct ip6_frag *fh;
910 struct ip6_rthdr *rth;
911 struct ip6_rthdr0 *rth0;
912 int rthlen;
913
914 while (1) { /* XXX: should avoid infinite loop explicitly? */
915 struct ip6_ext *eh;
916
917 switch (nxt) {
918 case IPPROTO_HOPOPTS:
919 case IPPROTO_DSTOPTS:
920 case IPPROTO_AH:
921 #ifndef PULLDOWN_TEST
922 IP6_EXTHDR_CHECK(m, 0,
923 eoff + sizeof(struct ip6_ext), -1);
924 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
925 #else
926 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
927 eoff, sizeof(*eh));
928 if (eh == NULL) {
929 ICMP6STAT_INC(icp6s_tooshort);
930 return (-1);
931 }
932 #endif
933
934 if (nxt == IPPROTO_AH)
935 eoff += (eh->ip6e_len + 2) << 2;
936 else
937 eoff += (eh->ip6e_len + 1) << 3;
938 nxt = eh->ip6e_nxt;
939 break;
940 case IPPROTO_ROUTING:
941 /*
942 * When the erroneous packet contains a
943 * routing header, we should examine the
944 * header to determine the final destination.
945 * Otherwise, we can't properly update
946 * information that depends on the final
947 * destination (e.g. path MTU).
948 */
949 #ifndef PULLDOWN_TEST
950 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
951 rth = (struct ip6_rthdr *)
952 (mtod(m, caddr_t) + eoff);
953 #else
954 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
955 eoff, sizeof(*rth));
956 if (rth == NULL) {
957 ICMP6STAT_INC(icp6s_tooshort);
958 return (-1);
959 }
960 #endif
961 rthlen = (rth->ip6r_len + 1) << 3;
962 /*
963 * XXX: currently there is no
964 * officially defined type other
965 * than type-0.
966 * Note that if the segment left field
967 * is 0, all intermediate hops must
968 * have been passed.
969 */
970 if (rth->ip6r_segleft &&
971 rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
972 int hops;
973
974 #ifndef PULLDOWN_TEST
975 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
976 rth0 = (struct ip6_rthdr0 *)
977 (mtod(m, caddr_t) + eoff);
978 #else
979 IP6_EXTHDR_GET(rth0,
980 struct ip6_rthdr0 *, m,
981 eoff, rthlen);
982 if (rth0 == NULL) {
983 ICMP6STAT_INC(icp6s_tooshort);
984 return (-1);
985 }
986 #endif
987 /* just ignore a bogus header */
988 if ((rth0->ip6r0_len % 2) == 0 &&
989 (hops = rth0->ip6r0_len/2))
990 icmp6dst.sin6_addr = *((struct in6_addr *)(rth0 + 1) + (hops - 1));
991 }
992 eoff += rthlen;
993 nxt = rth->ip6r_nxt;
994 break;
995 case IPPROTO_FRAGMENT:
996 #ifndef PULLDOWN_TEST
997 IP6_EXTHDR_CHECK(m, 0, eoff +
998 sizeof(struct ip6_frag), -1);
999 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1000 eoff);
1001 #else
1002 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1003 eoff, sizeof(*fh));
1004 if (fh == NULL) {
1005 ICMP6STAT_INC(icp6s_tooshort);
1006 return (-1);
1007 }
1008 #endif
1009 /*
1010 * Data after a fragment header is meaningless
1011 * unless it is the first fragment, but
1012 * we'll go to the notify label for path MTU
1013 * discovery.
1014 */
1015 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1016 goto notify;
1017
1018 eoff += sizeof(struct ip6_frag);
1019 nxt = fh->ip6f_nxt;
1020 break;
1021 default:
1022 /*
1023 * This case includes ESP and the No Next
1024 * Header. In such cases going to the notify
1025 * label does not have any meaning
1026 * (i.e. ctlfunc will be NULL), but we go
1027 * anyway since we might have to update
1028 * path MTU information.
1029 */
1030 goto notify;
1031 }
1032 }
1033 notify:
1034 #ifndef PULLDOWN_TEST
1035 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1036 #else
1037 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1038 sizeof(*icmp6) + sizeof(struct ip6_hdr));
1039 if (icmp6 == NULL) {
1040 ICMP6STAT_INC(icp6s_tooshort);
1041 return (-1);
1042 }
1043 #endif
1044
1045 /*
1046 * retrieve parameters from the inner IPv6 header, and convert
1047 * them into sockaddr structures.
1048 * XXX: there is no guarantee that the source or destination
1049 * addresses of the inner packet are in the same scope as
1050 * the addresses of the icmp packet. But there is no other
1051 * way to determine the zone.
1052 */
1053 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1054
1055 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1056 icmp6dst.sin6_family = AF_INET6;
1057 if (IN6_IS_ADDR_UNSPECIFIED(&icmp6dst.sin6_addr))
1058 icmp6dst.sin6_addr = eip6->ip6_dst;
1059 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1060 goto freeit;
1061 bzero(&icmp6src, sizeof(icmp6src));
1062 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1063 icmp6src.sin6_family = AF_INET6;
1064 icmp6src.sin6_addr = eip6->ip6_src;
1065 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1066 goto freeit;
1067 icmp6src.sin6_flowinfo =
1068 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1069
1070 ip6cp.ip6c_m = m;
1071 ip6cp.ip6c_icmp6 = icmp6;
1072 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1073 ip6cp.ip6c_off = eoff;
1074 ip6cp.ip6c_finaldst = &icmp6dst.sin6_addr;
1075 ip6cp.ip6c_src = &icmp6src;
1076 ip6cp.ip6c_nxt = nxt;
1077
1078 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1079 notifymtu = ntohl(icmp6->icmp6_mtu);
1080 ip6cp.ip6c_cmdarg = (void *)¬ifymtu;
1081 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/
1082 }
1083
1084 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1085 (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1086 if (ctlfunc) {
1087 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1088 &ip6cp);
1089 }
1090 }
1091 *mp = m;
1092 return (0);
1093
1094 freeit:
1095 m_freem(m);
1096 return (-1);
1097 }
1098
1099 void
icmp6_mtudisc_update(struct ip6ctlparam * ip6cp,int validated)1100 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1101 {
1102 struct in6_addr *dst = ip6cp->ip6c_finaldst;
1103 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1104 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1105 u_int mtu = ntohl(icmp6->icmp6_mtu);
1106 struct in_conninfo inc;
1107
1108 #if 0
1109 /*
1110 * RFC2460 section 5, last paragraph.
1111 * even though minimum link MTU for IPv6 is IPV6_MMTU,
1112 * we may see ICMPv6 too big with mtu < IPV6_MMTU
1113 * due to packet translator in the middle.
1114 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1115 * special handling.
1116 */
1117 if (mtu < IPV6_MMTU)
1118 return;
1119 #endif
1120
1121 /*
1122 * we reject ICMPv6 too big with abnormally small value.
1123 * XXX what is the good definition of "abnormally small"?
1124 */
1125 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1126 return;
1127
1128 if (!validated)
1129 return;
1130
1131 /*
1132 * In case the suggested mtu is less than IPV6_MMTU, we
1133 * only need to remember that it was for above mentioned
1134 * "alwaysfrag" case.
1135 * Try to be as close to the spec as possible.
1136 */
1137 if (mtu < IPV6_MMTU)
1138 mtu = IPV6_MMTU - 8;
1139
1140 bzero(&inc, sizeof(inc));
1141 inc.inc_fibnum = M_GETFIB(m);
1142 inc.inc_flags |= INC_ISIPV6;
1143 inc.inc6_faddr = *dst;
1144 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1145 return;
1146
1147 if (mtu < tcp_maxmtu6(&inc, NULL)) {
1148 tcp_hc_updatemtu(&inc, mtu);
1149 ICMP6STAT_INC(icp6s_pmtuchg);
1150 }
1151 }
1152
1153 /*
1154 * Process a Node Information Query packet, based on
1155 * draft-ietf-ipngwg-icmp-name-lookups-07.
1156 *
1157 * Spec incompatibilities:
1158 * - IPv6 Subject address handling
1159 * - IPv4 Subject address handling support missing
1160 * - Proxy reply (answer even if it's not for me)
1161 * - joins NI group address at in6_ifattach() time only, does not cope
1162 * with hostname changes by sethostname(3)
1163 */
1164 static struct mbuf *
ni6_input(struct mbuf * m,int off)1165 ni6_input(struct mbuf *m, int off)
1166 {
1167 struct icmp6_nodeinfo *ni6, *nni6;
1168 struct mbuf *n = NULL;
1169 struct prison *pr;
1170 u_int16_t qtype;
1171 int subjlen;
1172 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1173 struct ni_reply_fqdn *fqdn;
1174 int addrs; /* for NI_QTYPE_NODEADDR */
1175 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1176 struct in6_addr in6_subj; /* subject address */
1177 struct ip6_hdr *ip6;
1178 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */
1179 char *subj = NULL;
1180 struct in6_ifaddr *ia6 = NULL;
1181
1182 ip6 = mtod(m, struct ip6_hdr *);
1183 #ifndef PULLDOWN_TEST
1184 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1185 #else
1186 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1187 if (ni6 == NULL) {
1188 /* m is already reclaimed */
1189 return (NULL);
1190 }
1191 #endif
1192
1193 /*
1194 * Validate IPv6 source address.
1195 * The default configuration MUST be to refuse answering queries from
1196 * global-scope addresses according to RFC4602.
1197 * Notes:
1198 * - it's not very clear what "refuse" means; this implementation
1199 * simply drops it.
1200 * - it's not very easy to identify global-scope (unicast) addresses
1201 * since there are many prefixes for them. It should be safer
1202 * and in practice sufficient to check "all" but loopback and
1203 * link-local (note that site-local unicast was deprecated and
1204 * ULA is defined as global scope-wise)
1205 */
1206 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1207 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1208 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1209 goto bad;
1210
1211 /*
1212 * Validate IPv6 destination address.
1213 *
1214 * The Responder must discard the Query without further processing
1215 * unless it is one of the Responder's unicast or anycast addresses, or
1216 * a link-local scope multicast address which the Responder has joined.
1217 * [RFC4602, Section 5.]
1218 */
1219 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1220 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1221 goto bad;
1222 /* else it's a link-local multicast, fine */
1223 } else { /* unicast or anycast */
1224 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
1225 if (ia6 == NULL)
1226 goto bad; /* XXX impossible */
1227
1228 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1229 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1230 ifa_free(&ia6->ia_ifa);
1231 nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1232 "a temporary address in %s:%d",
1233 __FILE__, __LINE__));
1234 goto bad;
1235 }
1236 ifa_free(&ia6->ia_ifa);
1237 }
1238
1239 /* validate query Subject field. */
1240 qtype = ntohs(ni6->ni_qtype);
1241 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1242 switch (qtype) {
1243 case NI_QTYPE_NOOP:
1244 case NI_QTYPE_SUPTYPES:
1245 /* 07 draft */
1246 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1247 break;
1248 /* FALLTHROUGH */
1249 case NI_QTYPE_FQDN:
1250 case NI_QTYPE_NODEADDR:
1251 case NI_QTYPE_IPV4ADDR:
1252 switch (ni6->ni_code) {
1253 case ICMP6_NI_SUBJ_IPV6:
1254 #if ICMP6_NI_SUBJ_IPV6 != 0
1255 case 0:
1256 #endif
1257 /*
1258 * backward compatibility - try to accept 03 draft
1259 * format, where no Subject is present.
1260 */
1261 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1262 subjlen == 0) {
1263 oldfqdn++;
1264 break;
1265 }
1266 #if ICMP6_NI_SUBJ_IPV6 != 0
1267 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1268 goto bad;
1269 #endif
1270
1271 if (subjlen != sizeof(struct in6_addr))
1272 goto bad;
1273
1274 /*
1275 * Validate Subject address.
1276 *
1277 * Not sure what exactly "address belongs to the node"
1278 * means in the spec, is it just unicast, or what?
1279 *
1280 * At this moment we consider Subject address as
1281 * "belong to the node" if the Subject address equals
1282 * to the IPv6 destination address; validation for
1283 * IPv6 destination address should have done enough
1284 * check for us.
1285 *
1286 * We do not do proxy at this moment.
1287 */
1288 /* m_pulldown instead of copy? */
1289 m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1290 subjlen, (caddr_t)&in6_subj);
1291 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1292 goto bad;
1293
1294 subj = (char *)&in6_subj;
1295 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1296 break;
1297
1298 /*
1299 * XXX if we are to allow other cases, we should really
1300 * be careful about scope here.
1301 * basically, we should disallow queries toward IPv6
1302 * destination X with subject Y,
1303 * if scope(X) > scope(Y).
1304 * if we allow scope(X) > scope(Y), it will result in
1305 * information leakage across scope boundary.
1306 */
1307 goto bad;
1308
1309 case ICMP6_NI_SUBJ_FQDN:
1310 /*
1311 * Validate Subject name with gethostname(3).
1312 *
1313 * The behavior may need some debate, since:
1314 * - we are not sure if the node has FQDN as
1315 * hostname (returned by gethostname(3)).
1316 * - the code does wildcard match for truncated names.
1317 * however, we are not sure if we want to perform
1318 * wildcard match, if gethostname(3) side has
1319 * truncated hostname.
1320 */
1321 pr = curthread->td_ucred->cr_prison;
1322 mtx_lock(&pr->pr_mtx);
1323 n = ni6_nametodns(pr->pr_hostname,
1324 strlen(pr->pr_hostname), 0);
1325 mtx_unlock(&pr->pr_mtx);
1326 if (!n || n->m_next || n->m_len == 0)
1327 goto bad;
1328 IP6_EXTHDR_GET(subj, char *, m,
1329 off + sizeof(struct icmp6_nodeinfo), subjlen);
1330 if (subj == NULL)
1331 goto bad;
1332 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1333 n->m_len)) {
1334 goto bad;
1335 }
1336 m_freem(n);
1337 n = NULL;
1338 break;
1339
1340 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */
1341 default:
1342 goto bad;
1343 }
1344 break;
1345 }
1346
1347 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */
1348 switch (qtype) {
1349 case NI_QTYPE_FQDN:
1350 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1351 goto bad;
1352 break;
1353 case NI_QTYPE_NODEADDR:
1354 case NI_QTYPE_IPV4ADDR:
1355 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1356 goto bad;
1357 break;
1358 }
1359
1360 /* guess reply length */
1361 switch (qtype) {
1362 case NI_QTYPE_NOOP:
1363 break; /* no reply data */
1364 case NI_QTYPE_SUPTYPES:
1365 replylen += sizeof(u_int32_t);
1366 break;
1367 case NI_QTYPE_FQDN:
1368 /* XXX will append an mbuf */
1369 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1370 break;
1371 case NI_QTYPE_NODEADDR:
1372 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1373 if ((replylen += addrs * (sizeof(struct in6_addr) +
1374 sizeof(u_int32_t))) > MCLBYTES)
1375 replylen = MCLBYTES; /* XXX: will truncate pkt later */
1376 break;
1377 case NI_QTYPE_IPV4ADDR:
1378 /* unsupported - should respond with unknown Qtype? */
1379 break;
1380 default:
1381 /*
1382 * XXX: We must return a reply with the ICMP6 code
1383 * `unknown Qtype' in this case. However we regard the case
1384 * as an FQDN query for backward compatibility.
1385 * Older versions set a random value to this field,
1386 * so it rarely varies in the defined qtypes.
1387 * But the mechanism is not reliable...
1388 * maybe we should obsolete older versions.
1389 */
1390 qtype = NI_QTYPE_FQDN;
1391 /* XXX will append an mbuf */
1392 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1393 oldfqdn++;
1394 break;
1395 }
1396
1397 /* Allocate an mbuf to reply. */
1398 if (replylen > MCLBYTES) {
1399 /*
1400 * XXX: should we try to allocate more? But MCLBYTES
1401 * is probably much larger than IPV6_MMTU...
1402 */
1403 goto bad;
1404 }
1405 if (replylen > MHLEN)
1406 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR);
1407 else
1408 n = m_gethdr(M_NOWAIT, m->m_type);
1409 if (n == NULL) {
1410 m_freem(m);
1411 return (NULL);
1412 }
1413 m_move_pkthdr(n, m); /* just for recvif and FIB */
1414 n->m_pkthdr.len = n->m_len = replylen;
1415
1416 /* copy mbuf header and IPv6 + Node Information base headers */
1417 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1418 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1419 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1420
1421 /* qtype dependent procedure */
1422 switch (qtype) {
1423 case NI_QTYPE_NOOP:
1424 nni6->ni_code = ICMP6_NI_SUCCESS;
1425 nni6->ni_flags = 0;
1426 break;
1427 case NI_QTYPE_SUPTYPES:
1428 {
1429 u_int32_t v;
1430 nni6->ni_code = ICMP6_NI_SUCCESS;
1431 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1432 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1433 v = (u_int32_t)htonl(0x0000000f);
1434 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1435 break;
1436 }
1437 case NI_QTYPE_FQDN:
1438 nni6->ni_code = ICMP6_NI_SUCCESS;
1439 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1440 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1441 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1442 fqdn->ni_fqdn_ttl = 0; /* ditto. */
1443 /*
1444 * XXX do we really have FQDN in hostname?
1445 */
1446 pr = curthread->td_ucred->cr_prison;
1447 mtx_lock(&pr->pr_mtx);
1448 n->m_next = ni6_nametodns(pr->pr_hostname,
1449 strlen(pr->pr_hostname), oldfqdn);
1450 mtx_unlock(&pr->pr_mtx);
1451 if (n->m_next == NULL)
1452 goto bad;
1453 /* XXX we assume that n->m_next is not a chain */
1454 if (n->m_next->m_next != NULL)
1455 goto bad;
1456 n->m_pkthdr.len += n->m_next->m_len;
1457 break;
1458 case NI_QTYPE_NODEADDR:
1459 {
1460 int lenlim, copied;
1461
1462 nni6->ni_code = ICMP6_NI_SUCCESS;
1463 n->m_pkthdr.len = n->m_len =
1464 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1465 lenlim = M_TRAILINGSPACE(n);
1466 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1467 /* XXX: reset mbuf length */
1468 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1469 sizeof(struct icmp6_nodeinfo) + copied;
1470 break;
1471 }
1472 default:
1473 break; /* XXX impossible! */
1474 }
1475
1476 nni6->ni_type = ICMP6_NI_REPLY;
1477 m_freem(m);
1478 return (n);
1479
1480 bad:
1481 m_freem(m);
1482 if (n)
1483 m_freem(n);
1484 return (NULL);
1485 }
1486
1487 /*
1488 * make a mbuf with DNS-encoded string. no compression support.
1489 *
1490 * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1491 * treated as truncated name (two \0 at the end). this is a wild guess.
1492 *
1493 * old - return pascal string if non-zero
1494 */
1495 static struct mbuf *
ni6_nametodns(const char * name,int namelen,int old)1496 ni6_nametodns(const char *name, int namelen, int old)
1497 {
1498 struct mbuf *m;
1499 char *cp, *ep;
1500 const char *p, *q;
1501 int i, len, nterm;
1502
1503 if (old)
1504 len = namelen + 1;
1505 else
1506 len = MCLBYTES;
1507
1508 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */
1509 if (len > MLEN)
1510 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1511 else
1512 m = m_get(M_NOWAIT, MT_DATA);
1513 if (m == NULL)
1514 goto fail;
1515
1516 if (old) {
1517 m->m_len = len;
1518 *mtod(m, char *) = namelen;
1519 bcopy(name, mtod(m, char *) + 1, namelen);
1520 return m;
1521 } else {
1522 m->m_len = 0;
1523 cp = mtod(m, char *);
1524 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1525
1526 /* if not certain about my name, return empty buffer */
1527 if (namelen == 0)
1528 return m;
1529
1530 /*
1531 * guess if it looks like shortened hostname, or FQDN.
1532 * shortened hostname needs two trailing "\0".
1533 */
1534 i = 0;
1535 for (p = name; p < name + namelen; p++) {
1536 if (*p && *p == '.')
1537 i++;
1538 }
1539 if (i < 2)
1540 nterm = 2;
1541 else
1542 nterm = 1;
1543
1544 p = name;
1545 while (cp < ep && p < name + namelen) {
1546 i = 0;
1547 for (q = p; q < name + namelen && *q && *q != '.'; q++)
1548 i++;
1549 /* result does not fit into mbuf */
1550 if (cp + i + 1 >= ep)
1551 goto fail;
1552 /*
1553 * DNS label length restriction, RFC1035 page 8.
1554 * "i == 0" case is included here to avoid returning
1555 * 0-length label on "foo..bar".
1556 */
1557 if (i <= 0 || i >= 64)
1558 goto fail;
1559 *cp++ = i;
1560 bcopy(p, cp, i);
1561 cp += i;
1562 p = q;
1563 if (p < name + namelen && *p == '.')
1564 p++;
1565 }
1566 /* termination */
1567 if (cp + nterm >= ep)
1568 goto fail;
1569 while (nterm-- > 0)
1570 *cp++ = '\0';
1571 m->m_len = cp - mtod(m, char *);
1572 return m;
1573 }
1574
1575 panic("should not reach here");
1576 /* NOTREACHED */
1577
1578 fail:
1579 if (m)
1580 m_freem(m);
1581 return NULL;
1582 }
1583
1584 /*
1585 * check if two DNS-encoded string matches. takes care of truncated
1586 * form (with \0\0 at the end). no compression support.
1587 * XXX upper/lowercase match (see RFC2065)
1588 */
1589 static int
ni6_dnsmatch(const char * a,int alen,const char * b,int blen)1590 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1591 {
1592 const char *a0, *b0;
1593 int l;
1594
1595 /* simplest case - need validation? */
1596 if (alen == blen && bcmp(a, b, alen) == 0)
1597 return 1;
1598
1599 a0 = a;
1600 b0 = b;
1601
1602 /* termination is mandatory */
1603 if (alen < 2 || blen < 2)
1604 return 0;
1605 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1606 return 0;
1607 alen--;
1608 blen--;
1609
1610 while (a - a0 < alen && b - b0 < blen) {
1611 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1612 return 0;
1613
1614 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1615 return 0;
1616 /* we don't support compression yet */
1617 if (a[0] >= 64 || b[0] >= 64)
1618 return 0;
1619
1620 /* truncated case */
1621 if (a[0] == 0 && a - a0 == alen - 1)
1622 return 1;
1623 if (b[0] == 0 && b - b0 == blen - 1)
1624 return 1;
1625 if (a[0] == 0 || b[0] == 0)
1626 return 0;
1627
1628 if (a[0] != b[0])
1629 return 0;
1630 l = a[0];
1631 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1632 return 0;
1633 if (bcmp(a + 1, b + 1, l) != 0)
1634 return 0;
1635
1636 a += 1 + l;
1637 b += 1 + l;
1638 }
1639
1640 if (a - a0 == alen && b - b0 == blen)
1641 return 1;
1642 else
1643 return 0;
1644 }
1645
1646 /*
1647 * calculate the number of addresses to be returned in the node info reply.
1648 */
1649 static int
ni6_addrs(struct icmp6_nodeinfo * ni6,struct mbuf * m,struct ifnet ** ifpp,struct in6_addr * subj)1650 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1651 struct in6_addr *subj)
1652 {
1653 struct ifnet *ifp;
1654 struct in6_ifaddr *ifa6;
1655 struct ifaddr *ifa;
1656 int addrs = 0, addrsofif, iffound = 0;
1657 int niflags = ni6->ni_flags;
1658
1659 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1660 switch (ni6->ni_code) {
1661 case ICMP6_NI_SUBJ_IPV6:
1662 if (subj == NULL) /* must be impossible... */
1663 return (0);
1664 break;
1665 default:
1666 /*
1667 * XXX: we only support IPv6 subject address for
1668 * this Qtype.
1669 */
1670 return (0);
1671 }
1672 }
1673
1674 IFNET_RLOCK_NOSLEEP();
1675 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1676 addrsofif = 0;
1677 IF_ADDR_RLOCK(ifp);
1678 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1679 if (ifa->ifa_addr->sa_family != AF_INET6)
1680 continue;
1681 ifa6 = (struct in6_ifaddr *)ifa;
1682
1683 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1684 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1685 iffound = 1;
1686
1687 /*
1688 * IPv4-mapped addresses can only be returned by a
1689 * Node Information proxy, since they represent
1690 * addresses of IPv4-only nodes, which perforce do
1691 * not implement this protocol.
1692 * [icmp-name-lookups-07, Section 5.4]
1693 * So we don't support NI_NODEADDR_FLAG_COMPAT in
1694 * this function at this moment.
1695 */
1696
1697 /* What do we have to do about ::1? */
1698 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1699 case IPV6_ADDR_SCOPE_LINKLOCAL:
1700 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1701 continue;
1702 break;
1703 case IPV6_ADDR_SCOPE_SITELOCAL:
1704 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1705 continue;
1706 break;
1707 case IPV6_ADDR_SCOPE_GLOBAL:
1708 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1709 continue;
1710 break;
1711 default:
1712 continue;
1713 }
1714
1715 /*
1716 * check if anycast is okay.
1717 * XXX: just experimental. not in the spec.
1718 */
1719 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1720 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1721 continue; /* we need only unicast addresses */
1722 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1723 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1724 continue;
1725 }
1726 addrsofif++; /* count the address */
1727 }
1728 IF_ADDR_RUNLOCK(ifp);
1729 if (iffound) {
1730 *ifpp = ifp;
1731 IFNET_RUNLOCK_NOSLEEP();
1732 return (addrsofif);
1733 }
1734
1735 addrs += addrsofif;
1736 }
1737 IFNET_RUNLOCK_NOSLEEP();
1738
1739 return (addrs);
1740 }
1741
1742 static int
ni6_store_addrs(struct icmp6_nodeinfo * ni6,struct icmp6_nodeinfo * nni6,struct ifnet * ifp0,int resid)1743 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1744 struct ifnet *ifp0, int resid)
1745 {
1746 struct ifnet *ifp;
1747 struct in6_ifaddr *ifa6;
1748 struct ifaddr *ifa;
1749 struct ifnet *ifp_dep = NULL;
1750 int copied = 0, allow_deprecated = 0;
1751 u_char *cp = (u_char *)(nni6 + 1);
1752 int niflags = ni6->ni_flags;
1753 u_int32_t ltime;
1754
1755 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1756 return (0); /* needless to copy */
1757
1758 IFNET_RLOCK_NOSLEEP();
1759 ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet);
1760 again:
1761
1762 for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) {
1763 IF_ADDR_RLOCK(ifp);
1764 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1765 if (ifa->ifa_addr->sa_family != AF_INET6)
1766 continue;
1767 ifa6 = (struct in6_ifaddr *)ifa;
1768
1769 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1770 allow_deprecated == 0) {
1771 /*
1772 * prefererred address should be put before
1773 * deprecated addresses.
1774 */
1775
1776 /* record the interface for later search */
1777 if (ifp_dep == NULL)
1778 ifp_dep = ifp;
1779
1780 continue;
1781 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1782 allow_deprecated != 0)
1783 continue; /* we now collect deprecated addrs */
1784
1785 /* What do we have to do about ::1? */
1786 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1787 case IPV6_ADDR_SCOPE_LINKLOCAL:
1788 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1789 continue;
1790 break;
1791 case IPV6_ADDR_SCOPE_SITELOCAL:
1792 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1793 continue;
1794 break;
1795 case IPV6_ADDR_SCOPE_GLOBAL:
1796 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1797 continue;
1798 break;
1799 default:
1800 continue;
1801 }
1802
1803 /*
1804 * check if anycast is okay.
1805 * XXX: just experimental. not in the spec.
1806 */
1807 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1808 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1809 continue;
1810 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1811 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1812 continue;
1813 }
1814
1815 /* now we can copy the address */
1816 if (resid < sizeof(struct in6_addr) +
1817 sizeof(u_int32_t)) {
1818 IF_ADDR_RUNLOCK(ifp);
1819 /*
1820 * We give up much more copy.
1821 * Set the truncate flag and return.
1822 */
1823 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1824 IFNET_RUNLOCK_NOSLEEP();
1825 return (copied);
1826 }
1827
1828 /*
1829 * Set the TTL of the address.
1830 * The TTL value should be one of the following
1831 * according to the specification:
1832 *
1833 * 1. The remaining lifetime of a DHCP lease on the
1834 * address, or
1835 * 2. The remaining Valid Lifetime of a prefix from
1836 * which the address was derived through Stateless
1837 * Autoconfiguration.
1838 *
1839 * Note that we currently do not support stateful
1840 * address configuration by DHCPv6, so the former
1841 * case can't happen.
1842 */
1843 if (ifa6->ia6_lifetime.ia6t_expire == 0)
1844 ltime = ND6_INFINITE_LIFETIME;
1845 else {
1846 if (ifa6->ia6_lifetime.ia6t_expire >
1847 time_uptime)
1848 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime);
1849 else
1850 ltime = 0;
1851 }
1852
1853 bcopy(<ime, cp, sizeof(u_int32_t));
1854 cp += sizeof(u_int32_t);
1855
1856 /* copy the address itself */
1857 bcopy(&ifa6->ia_addr.sin6_addr, cp,
1858 sizeof(struct in6_addr));
1859 in6_clearscope((struct in6_addr *)cp); /* XXX */
1860 cp += sizeof(struct in6_addr);
1861
1862 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1863 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1864 }
1865 IF_ADDR_RUNLOCK(ifp);
1866 if (ifp0) /* we need search only on the specified IF */
1867 break;
1868 }
1869
1870 if (allow_deprecated == 0 && ifp_dep != NULL) {
1871 ifp = ifp_dep;
1872 allow_deprecated = 1;
1873
1874 goto again;
1875 }
1876
1877 IFNET_RUNLOCK_NOSLEEP();
1878
1879 return (copied);
1880 }
1881
1882 /*
1883 * XXX almost dup'ed code with rip6_input.
1884 */
1885 static int
icmp6_rip6_input(struct mbuf ** mp,int off)1886 icmp6_rip6_input(struct mbuf **mp, int off)
1887 {
1888 struct mbuf *m = *mp;
1889 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1890 struct inpcb *in6p;
1891 struct inpcb *last = NULL;
1892 struct sockaddr_in6 fromsa;
1893 struct icmp6_hdr *icmp6;
1894 struct epoch_tracker et;
1895 struct mbuf *opts = NULL;
1896
1897 #ifndef PULLDOWN_TEST
1898 /* this is assumed to be safe. */
1899 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1900 #else
1901 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1902 if (icmp6 == NULL) {
1903 /* m is already reclaimed */
1904 return (IPPROTO_DONE);
1905 }
1906 #endif
1907
1908 /*
1909 * XXX: the address may have embedded scope zone ID, which should be
1910 * hidden from applications.
1911 */
1912 bzero(&fromsa, sizeof(fromsa));
1913 fromsa.sin6_family = AF_INET6;
1914 fromsa.sin6_len = sizeof(struct sockaddr_in6);
1915 fromsa.sin6_addr = ip6->ip6_src;
1916 if (sa6_recoverscope(&fromsa)) {
1917 m_freem(m);
1918 return (IPPROTO_DONE);
1919 }
1920
1921 INP_INFO_RLOCK_ET(&V_ripcbinfo, et);
1922 CK_LIST_FOREACH(in6p, &V_ripcb, inp_list) {
1923 if ((in6p->inp_vflag & INP_IPV6) == 0)
1924 continue;
1925 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
1926 continue;
1927 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1928 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1929 continue;
1930 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1931 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1932 continue;
1933 INP_RLOCK(in6p);
1934 if (__predict_false(in6p->inp_flags2 & INP_FREED)) {
1935 INP_RUNLOCK(in6p);
1936 continue;
1937 }
1938 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1939 in6p->in6p_icmp6filt)) {
1940 INP_RUNLOCK(in6p);
1941 continue;
1942 }
1943 if (last != NULL) {
1944 struct mbuf *n = NULL;
1945
1946 /*
1947 * Recent network drivers tend to allocate a single
1948 * mbuf cluster, rather than to make a couple of
1949 * mbufs without clusters. Also, since the IPv6 code
1950 * path tries to avoid m_pullup(), it is highly
1951 * probable that we still have an mbuf cluster here
1952 * even though the necessary length can be stored in an
1953 * mbuf's internal buffer.
1954 * Meanwhile, the default size of the receive socket
1955 * buffer for raw sockets is not so large. This means
1956 * the possibility of packet loss is relatively higher
1957 * than before. To avoid this scenario, we copy the
1958 * received data to a separate mbuf that does not use
1959 * a cluster, if possible.
1960 * XXX: it is better to copy the data after stripping
1961 * intermediate headers.
1962 */
1963 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1964 m->m_len <= MHLEN) {
1965 n = m_get(M_NOWAIT, m->m_type);
1966 if (n != NULL) {
1967 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1968 bcopy(m->m_data, n->m_data,
1969 m->m_len);
1970 n->m_len = m->m_len;
1971 } else {
1972 m_free(n);
1973 n = NULL;
1974 }
1975 }
1976 }
1977 if (n != NULL ||
1978 (n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) {
1979 if (last->inp_flags & INP_CONTROLOPTS)
1980 ip6_savecontrol(last, n, &opts);
1981 /* strip intermediate headers */
1982 m_adj(n, off);
1983 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
1984 if (sbappendaddr_locked(
1985 &last->inp_socket->so_rcv,
1986 (struct sockaddr *)&fromsa, n, opts)
1987 == 0) {
1988 /* should notify about lost packet */
1989 m_freem(n);
1990 if (opts) {
1991 m_freem(opts);
1992 }
1993 SOCKBUF_UNLOCK(
1994 &last->inp_socket->so_rcv);
1995 } else
1996 sorwakeup_locked(last->inp_socket);
1997 opts = NULL;
1998 }
1999 INP_RUNLOCK(last);
2000 }
2001 last = in6p;
2002 }
2003 INP_INFO_RUNLOCK_ET(&V_ripcbinfo, et);
2004 if (last != NULL) {
2005 if (last->inp_flags & INP_CONTROLOPTS)
2006 ip6_savecontrol(last, m, &opts);
2007 /* strip intermediate headers */
2008 m_adj(m, off);
2009
2010 /* avoid using mbuf clusters if possible (see above) */
2011 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2012 m->m_len <= MHLEN) {
2013 struct mbuf *n;
2014
2015 n = m_get(M_NOWAIT, m->m_type);
2016 if (n != NULL) {
2017 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2018 bcopy(m->m_data, n->m_data, m->m_len);
2019 n->m_len = m->m_len;
2020
2021 m_freem(m);
2022 m = n;
2023 } else {
2024 m_freem(n);
2025 n = NULL;
2026 }
2027 }
2028 }
2029 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2030 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
2031 (struct sockaddr *)&fromsa, m, opts) == 0) {
2032 m_freem(m);
2033 if (opts)
2034 m_freem(opts);
2035 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
2036 } else
2037 sorwakeup_locked(last->inp_socket);
2038 INP_RUNLOCK(last);
2039 } else {
2040 m_freem(m);
2041 IP6STAT_DEC(ip6s_delivered);
2042 }
2043 return IPPROTO_DONE;
2044 }
2045
2046 /*
2047 * Reflect the ip6 packet back to the source.
2048 * OFF points to the icmp6 header, counted from the top of the mbuf.
2049 */
2050 void
icmp6_reflect(struct mbuf * m,size_t off)2051 icmp6_reflect(struct mbuf *m, size_t off)
2052 {
2053 struct in6_addr src6, *srcp;
2054 struct ip6_hdr *ip6;
2055 struct icmp6_hdr *icmp6;
2056 struct in6_ifaddr *ia = NULL;
2057 struct ifnet *outif = NULL;
2058 int plen;
2059 int type, code, hlim;
2060
2061 /* too short to reflect */
2062 if (off < sizeof(struct ip6_hdr)) {
2063 nd6log((LOG_DEBUG,
2064 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2065 (u_long)off, (u_long)sizeof(struct ip6_hdr),
2066 __FILE__, __LINE__));
2067 goto bad;
2068 }
2069
2070 /*
2071 * If there are extra headers between IPv6 and ICMPv6, strip
2072 * off that header first.
2073 */
2074 #ifdef DIAGNOSTIC
2075 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2076 panic("assumption failed in icmp6_reflect");
2077 #endif
2078 if (off > sizeof(struct ip6_hdr)) {
2079 size_t l;
2080 struct ip6_hdr nip6;
2081
2082 l = off - sizeof(struct ip6_hdr);
2083 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2084 m_adj(m, l);
2085 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2086 if (m->m_len < l) {
2087 if ((m = m_pullup(m, l)) == NULL)
2088 return;
2089 }
2090 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2091 } else /* off == sizeof(struct ip6_hdr) */ {
2092 size_t l;
2093 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2094 if (m->m_len < l) {
2095 if ((m = m_pullup(m, l)) == NULL)
2096 return;
2097 }
2098 }
2099 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2100 ip6 = mtod(m, struct ip6_hdr *);
2101 ip6->ip6_nxt = IPPROTO_ICMPV6;
2102 icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2103 type = icmp6->icmp6_type; /* keep type for statistics */
2104 code = icmp6->icmp6_code; /* ditto. */
2105 hlim = 0;
2106 srcp = NULL;
2107
2108 /*
2109 * If the incoming packet was addressed directly to us (i.e. unicast),
2110 * use dst as the src for the reply.
2111 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2112 * (for example) when we encounter an error while forwarding procedure
2113 * destined to a duplicated address of ours.
2114 */
2115 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
2116 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
2117 if (ia != NULL && !(ia->ia6_flags &
2118 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2119 src6 = ia->ia_addr.sin6_addr;
2120 srcp = &src6;
2121
2122 if (m->m_pkthdr.rcvif != NULL) {
2123 /* XXX: This may not be the outgoing interface */
2124 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2125 } else
2126 hlim = V_ip6_defhlim;
2127 }
2128 if (ia != NULL)
2129 ifa_free(&ia->ia_ifa);
2130 }
2131
2132 if (srcp == NULL) {
2133 int error;
2134 struct in6_addr dst6;
2135 uint32_t scopeid;
2136
2137 /*
2138 * This case matches to multicasts, our anycast, or unicasts
2139 * that we do not own. Select a source address based on the
2140 * source address of the erroneous packet.
2141 */
2142 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid);
2143 error = in6_selectsrc_addr(M_GETFIB(m), &dst6,
2144 scopeid, NULL, &src6, &hlim);
2145
2146 if (error) {
2147 char ip6buf[INET6_ADDRSTRLEN];
2148 nd6log((LOG_DEBUG,
2149 "icmp6_reflect: source can't be determined: "
2150 "dst=%s, error=%d\n",
2151 ip6_sprintf(ip6buf, &ip6->ip6_dst), error));
2152 goto bad;
2153 }
2154 srcp = &src6;
2155 }
2156 /*
2157 * ip6_input() drops a packet if its src is multicast.
2158 * So, the src is never multicast.
2159 */
2160 ip6->ip6_dst = ip6->ip6_src;
2161 ip6->ip6_src = *srcp;
2162 ip6->ip6_flow = 0;
2163 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2164 ip6->ip6_vfc |= IPV6_VERSION;
2165 ip6->ip6_nxt = IPPROTO_ICMPV6;
2166 ip6->ip6_hlim = hlim;
2167
2168 icmp6->icmp6_cksum = 0;
2169 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2170 sizeof(struct ip6_hdr), plen);
2171
2172 /*
2173 * XXX option handling
2174 */
2175
2176 m->m_flags &= ~(M_BCAST|M_MCAST);
2177 m->m_pkthdr.rcvif = NULL;
2178 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2179 if (outif)
2180 icmp6_ifoutstat_inc(outif, type, code);
2181
2182 return;
2183
2184 bad:
2185 m_freem(m);
2186 return;
2187 }
2188
2189 void
icmp6_fasttimo(void)2190 icmp6_fasttimo(void)
2191 {
2192
2193 mld_fasttimo();
2194 }
2195
2196 void
icmp6_slowtimo(void)2197 icmp6_slowtimo(void)
2198 {
2199
2200 mld_slowtimo();
2201 }
2202
2203 static const char *
icmp6_redirect_diag(struct in6_addr * src6,struct in6_addr * dst6,struct in6_addr * tgt6)2204 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2205 struct in6_addr *tgt6)
2206 {
2207 static char buf[1024];
2208 char ip6bufs[INET6_ADDRSTRLEN];
2209 char ip6bufd[INET6_ADDRSTRLEN];
2210 char ip6buft[INET6_ADDRSTRLEN];
2211 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2212 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2213 ip6_sprintf(ip6buft, tgt6));
2214 return buf;
2215 }
2216
2217 void
icmp6_redirect_input(struct mbuf * m,int off)2218 icmp6_redirect_input(struct mbuf *m, int off)
2219 {
2220 struct ifnet *ifp;
2221 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2222 struct nd_redirect *nd_rd;
2223 int icmp6len = ntohs(ip6->ip6_plen);
2224 char *lladdr = NULL;
2225 int lladdrlen = 0;
2226 int is_router;
2227 int is_onlink;
2228 struct in6_addr src6 = ip6->ip6_src;
2229 struct in6_addr redtgt6;
2230 struct in6_addr reddst6;
2231 union nd_opts ndopts;
2232 char ip6buf[INET6_ADDRSTRLEN];
2233
2234 M_ASSERTPKTHDR(m);
2235 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__));
2236
2237 ifp = m->m_pkthdr.rcvif;
2238
2239 /* XXX if we are router, we don't update route by icmp6 redirect */
2240 if (V_ip6_forwarding)
2241 goto freeit;
2242 if (!V_icmp6_rediraccept)
2243 goto freeit;
2244
2245 /* RFC 6980: Nodes MUST silently ignore fragments */
2246 if(m->m_flags & M_FRAGMENTED)
2247 goto freeit;
2248
2249 #ifndef PULLDOWN_TEST
2250 IP6_EXTHDR_CHECK(m, off, icmp6len,);
2251 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2252 #else
2253 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2254 if (nd_rd == NULL) {
2255 ICMP6STAT_INC(icp6s_tooshort);
2256 return;
2257 }
2258 #endif
2259 redtgt6 = nd_rd->nd_rd_target;
2260 reddst6 = nd_rd->nd_rd_dst;
2261
2262 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2263 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2264 goto freeit;
2265 }
2266
2267 /* validation */
2268 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2269 nd6log((LOG_ERR,
2270 "ICMP6 redirect sent from %s rejected; "
2271 "must be from linklocal\n",
2272 ip6_sprintf(ip6buf, &src6)));
2273 goto bad;
2274 }
2275 if (ip6->ip6_hlim != 255) {
2276 nd6log((LOG_ERR,
2277 "ICMP6 redirect sent from %s rejected; "
2278 "hlim=%d (must be 255)\n",
2279 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2280 goto bad;
2281 }
2282 {
2283 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2284 struct nhop6_basic nh6;
2285 struct in6_addr kdst;
2286 uint32_t scopeid;
2287
2288 in6_splitscope(&reddst6, &kdst, &scopeid);
2289 if (fib6_lookup_nh_basic(ifp->if_fib, &kdst, scopeid, 0, 0,&nh6)==0){
2290 if ((nh6.nh_flags & NHF_GATEWAY) == 0) {
2291 nd6log((LOG_ERR,
2292 "ICMP6 redirect rejected; no route "
2293 "with inet6 gateway found for redirect dst: %s\n",
2294 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2295 goto bad;
2296 }
2297
2298 /*
2299 * Embed scope zone id into next hop address, since
2300 * fib6_lookup_nh_basic() returns address without embedded
2301 * scope zone id.
2302 */
2303 if (in6_setscope(&nh6.nh_addr, m->m_pkthdr.rcvif, NULL))
2304 goto freeit;
2305
2306 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) {
2307 nd6log((LOG_ERR,
2308 "ICMP6 redirect rejected; "
2309 "not equal to gw-for-src=%s (must be same): "
2310 "%s\n",
2311 ip6_sprintf(ip6buf, &nh6.nh_addr),
2312 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2313 goto bad;
2314 }
2315 } else {
2316 nd6log((LOG_ERR,
2317 "ICMP6 redirect rejected; "
2318 "no route found for redirect dst: %s\n",
2319 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2320 goto bad;
2321 }
2322 }
2323 if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2324 nd6log((LOG_ERR,
2325 "ICMP6 redirect rejected; "
2326 "redirect dst must be unicast: %s\n",
2327 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2328 goto bad;
2329 }
2330
2331 is_router = is_onlink = 0;
2332 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2333 is_router = 1; /* router case */
2334 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2335 is_onlink = 1; /* on-link destination case */
2336 if (!is_router && !is_onlink) {
2337 nd6log((LOG_ERR,
2338 "ICMP6 redirect rejected; "
2339 "neither router case nor onlink case: %s\n",
2340 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2341 goto bad;
2342 }
2343
2344 icmp6len -= sizeof(*nd_rd);
2345 nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2346 if (nd6_options(&ndopts) < 0) {
2347 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n",
2348 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2349 /* nd6_options have incremented stats */
2350 goto freeit;
2351 }
2352
2353 if (ndopts.nd_opts_tgt_lladdr) {
2354 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2355 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2356 }
2357
2358 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2359 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s "
2360 "(if %d, icmp6 packet %d): %s\n",
2361 __func__, ip6_sprintf(ip6buf, &redtgt6),
2362 ifp->if_addrlen, lladdrlen - 2,
2363 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2364 goto bad;
2365 }
2366
2367 /* Validation passed. */
2368
2369 /* RFC 2461 8.3 */
2370 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2371 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2372
2373 /*
2374 * Install a gateway route in the better-router case or an interface
2375 * route in the on-link-destination case.
2376 */
2377 {
2378 struct sockaddr_in6 sdst;
2379 struct sockaddr_in6 sgw;
2380 struct sockaddr_in6 ssrc;
2381 struct sockaddr *gw;
2382 int rt_flags;
2383 u_int fibnum;
2384
2385 bzero(&sdst, sizeof(sdst));
2386 bzero(&ssrc, sizeof(ssrc));
2387 sdst.sin6_family = ssrc.sin6_family = AF_INET6;
2388 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6);
2389 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2390 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2391 rt_flags = RTF_HOST;
2392 if (is_router) {
2393 bzero(&sgw, sizeof(sgw));
2394 sgw.sin6_family = AF_INET6;
2395 sgw.sin6_len = sizeof(struct sockaddr_in6);
2396 bcopy(&redtgt6, &sgw.sin6_addr,
2397 sizeof(struct in6_addr));
2398 gw = (struct sockaddr *)&sgw;
2399 rt_flags |= RTF_GATEWAY;
2400 } else
2401 gw = ifp->if_addr->ifa_addr;
2402 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
2403 in6_rtredirect((struct sockaddr *)&sdst, gw,
2404 (struct sockaddr *)NULL, rt_flags,
2405 (struct sockaddr *)&ssrc, fibnum);
2406 }
2407 /* finally update cached route in each socket via pfctlinput */
2408 {
2409 struct sockaddr_in6 sdst;
2410
2411 bzero(&sdst, sizeof(sdst));
2412 sdst.sin6_family = AF_INET6;
2413 sdst.sin6_len = sizeof(struct sockaddr_in6);
2414 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2415 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2416 }
2417
2418 freeit:
2419 m_freem(m);
2420 return;
2421
2422 bad:
2423 ICMP6STAT_INC(icp6s_badredirect);
2424 m_freem(m);
2425 }
2426
2427 void
icmp6_redirect_output(struct mbuf * m0,struct rtentry * rt)2428 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2429 {
2430 struct ifnet *ifp; /* my outgoing interface */
2431 struct in6_addr *ifp_ll6;
2432 struct in6_addr *router_ll6;
2433 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */
2434 struct mbuf *m = NULL; /* newly allocated one */
2435 struct m_tag *mtag;
2436 struct ip6_hdr *ip6; /* m as struct ip6_hdr */
2437 struct nd_redirect *nd_rd;
2438 struct llentry *ln = NULL;
2439 size_t maxlen;
2440 u_char *p;
2441 struct ifnet *outif = NULL;
2442 struct sockaddr_in6 src_sa;
2443
2444 icmp6_errcount(ND_REDIRECT, 0);
2445
2446 /* if we are not router, we don't send icmp6 redirect */
2447 if (!V_ip6_forwarding)
2448 goto fail;
2449
2450 /* sanity check */
2451 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2452 goto fail;
2453
2454 /*
2455 * Address check:
2456 * the source address must identify a neighbor, and
2457 * the destination address must not be a multicast address
2458 * [RFC 2461, sec 8.2]
2459 */
2460 sip6 = mtod(m0, struct ip6_hdr *);
2461 bzero(&src_sa, sizeof(src_sa));
2462 src_sa.sin6_family = AF_INET6;
2463 src_sa.sin6_len = sizeof(src_sa);
2464 src_sa.sin6_addr = sip6->ip6_src;
2465 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2466 goto fail;
2467 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2468 goto fail; /* what should we do here? */
2469
2470 /* rate limit */
2471 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2472 goto fail;
2473
2474 /*
2475 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2476 * we almost always ask for an mbuf cluster for simplicity.
2477 * (MHLEN < IPV6_MMTU is almost always true)
2478 */
2479 #if IPV6_MMTU >= MCLBYTES
2480 # error assumption failed about IPV6_MMTU and MCLBYTES
2481 #endif
2482 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2483 if (m == NULL)
2484 goto fail;
2485 M_SETFIB(m, rt->rt_fibnum);
2486 maxlen = M_TRAILINGSPACE(m);
2487 maxlen = min(IPV6_MMTU, maxlen);
2488 /* just for safety */
2489 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2490 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2491 goto fail;
2492 }
2493
2494 {
2495 /* get ip6 linklocal address for ifp(my outgoing interface). */
2496 struct in6_ifaddr *ia;
2497 if ((ia = in6ifa_ifpforlinklocal(ifp,
2498 IN6_IFF_NOTREADY|
2499 IN6_IFF_ANYCAST)) == NULL)
2500 goto fail;
2501 ifp_ll6 = &ia->ia_addr.sin6_addr;
2502 /* XXXRW: reference released prematurely. */
2503 ifa_free(&ia->ia_ifa);
2504 }
2505
2506 /* get ip6 linklocal address for the router. */
2507 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2508 struct sockaddr_in6 *sin6;
2509 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2510 router_ll6 = &sin6->sin6_addr;
2511 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2512 router_ll6 = (struct in6_addr *)NULL;
2513 } else
2514 router_ll6 = (struct in6_addr *)NULL;
2515
2516 /* ip6 */
2517 ip6 = mtod(m, struct ip6_hdr *);
2518 ip6->ip6_flow = 0;
2519 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2520 ip6->ip6_vfc |= IPV6_VERSION;
2521 /* ip6->ip6_plen will be set later */
2522 ip6->ip6_nxt = IPPROTO_ICMPV6;
2523 ip6->ip6_hlim = 255;
2524 /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2525 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2526 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2527
2528 /* ND Redirect */
2529 nd_rd = (struct nd_redirect *)(ip6 + 1);
2530 nd_rd->nd_rd_type = ND_REDIRECT;
2531 nd_rd->nd_rd_code = 0;
2532 nd_rd->nd_rd_reserved = 0;
2533 if (rt->rt_flags & RTF_GATEWAY) {
2534 /*
2535 * nd_rd->nd_rd_target must be a link-local address in
2536 * better router cases.
2537 */
2538 if (!router_ll6)
2539 goto fail;
2540 bcopy(router_ll6, &nd_rd->nd_rd_target,
2541 sizeof(nd_rd->nd_rd_target));
2542 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2543 sizeof(nd_rd->nd_rd_dst));
2544 } else {
2545 /* make sure redtgt == reddst */
2546 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2547 sizeof(nd_rd->nd_rd_target));
2548 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2549 sizeof(nd_rd->nd_rd_dst));
2550 }
2551
2552 p = (u_char *)(nd_rd + 1);
2553
2554 if (!router_ll6)
2555 goto nolladdropt;
2556
2557 {
2558 /* target lladdr option */
2559 int len;
2560 struct nd_opt_hdr *nd_opt;
2561 char *lladdr;
2562
2563 IF_AFDATA_RLOCK(ifp);
2564 ln = nd6_lookup(router_ll6, 0, ifp);
2565 IF_AFDATA_RUNLOCK(ifp);
2566 if (ln == NULL)
2567 goto nolladdropt;
2568
2569 len = sizeof(*nd_opt) + ifp->if_addrlen;
2570 len = (len + 7) & ~7; /* round by 8 */
2571 /* safety check */
2572 if (len + (p - (u_char *)ip6) > maxlen)
2573 goto nolladdropt;
2574
2575 if (ln->la_flags & LLE_VALID) {
2576 nd_opt = (struct nd_opt_hdr *)p;
2577 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2578 nd_opt->nd_opt_len = len >> 3;
2579 lladdr = (char *)(nd_opt + 1);
2580 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen);
2581 p += len;
2582 }
2583 }
2584 nolladdropt:
2585 if (ln != NULL)
2586 LLE_RUNLOCK(ln);
2587
2588 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2589
2590 /* just to be safe */
2591 #ifdef M_DECRYPTED /*not openbsd*/
2592 if (m0->m_flags & M_DECRYPTED)
2593 goto noredhdropt;
2594 #endif
2595 if (p - (u_char *)ip6 > maxlen)
2596 goto noredhdropt;
2597
2598 {
2599 /* redirected header option */
2600 int len;
2601 struct nd_opt_rd_hdr *nd_opt_rh;
2602
2603 /*
2604 * compute the maximum size for icmp6 redirect header option.
2605 * XXX room for auth header?
2606 */
2607 len = maxlen - (p - (u_char *)ip6);
2608 len &= ~7;
2609
2610 /* This is just for simplicity. */
2611 if (m0->m_pkthdr.len != m0->m_len) {
2612 if (m0->m_next) {
2613 m_freem(m0->m_next);
2614 m0->m_next = NULL;
2615 }
2616 m0->m_pkthdr.len = m0->m_len;
2617 }
2618
2619 /*
2620 * Redirected header option spec (RFC2461 4.6.3) talks nothing
2621 * about padding/truncate rule for the original IP packet.
2622 * From the discussion on IPv6imp in Feb 1999,
2623 * the consensus was:
2624 * - "attach as much as possible" is the goal
2625 * - pad if not aligned (original size can be guessed by
2626 * original ip6 header)
2627 * Following code adds the padding if it is simple enough,
2628 * and truncates if not.
2629 */
2630 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2631 panic("assumption failed in %s:%d", __FILE__,
2632 __LINE__);
2633
2634 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2635 /* not enough room, truncate */
2636 m0->m_pkthdr.len = m0->m_len = len -
2637 sizeof(*nd_opt_rh);
2638 } else {
2639 /* enough room, pad or truncate */
2640 size_t extra;
2641
2642 extra = m0->m_pkthdr.len % 8;
2643 if (extra) {
2644 /* pad if easy enough, truncate if not */
2645 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2646 /* pad */
2647 m0->m_len += (8 - extra);
2648 m0->m_pkthdr.len += (8 - extra);
2649 } else {
2650 /* truncate */
2651 m0->m_pkthdr.len -= extra;
2652 m0->m_len -= extra;
2653 }
2654 }
2655 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2656 m0->m_pkthdr.len = m0->m_len = len -
2657 sizeof(*nd_opt_rh);
2658 }
2659
2660 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2661 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2662 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2663 nd_opt_rh->nd_opt_rh_len = len >> 3;
2664 p += sizeof(*nd_opt_rh);
2665 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2666
2667 /* connect m0 to m */
2668 m_tag_delete_chain(m0, NULL);
2669 m0->m_flags &= ~M_PKTHDR;
2670 m->m_next = m0;
2671 m->m_pkthdr.len = m->m_len + m0->m_len;
2672 m0 = NULL;
2673 }
2674 noredhdropt:;
2675 if (m0) {
2676 m_freem(m0);
2677 m0 = NULL;
2678 }
2679
2680 /* XXX: clear embedded link IDs in the inner header */
2681 in6_clearscope(&sip6->ip6_src);
2682 in6_clearscope(&sip6->ip6_dst);
2683 in6_clearscope(&nd_rd->nd_rd_target);
2684 in6_clearscope(&nd_rd->nd_rd_dst);
2685
2686 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2687
2688 nd_rd->nd_rd_cksum = 0;
2689 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2690 sizeof(*ip6), ntohs(ip6->ip6_plen));
2691
2692 if (send_sendso_input_hook != NULL) {
2693 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
2694 M_NOWAIT);
2695 if (mtag == NULL)
2696 goto fail;
2697 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
2698 m_tag_prepend(m, mtag);
2699 }
2700
2701 /* send the packet to outside... */
2702 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2703 if (outif) {
2704 icmp6_ifstat_inc(outif, ifs6_out_msg);
2705 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2706 }
2707 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2708
2709 return;
2710
2711 fail:
2712 if (m)
2713 m_freem(m);
2714 if (m0)
2715 m_freem(m0);
2716 }
2717
2718 /*
2719 * ICMPv6 socket option processing.
2720 */
2721 int
icmp6_ctloutput(struct socket * so,struct sockopt * sopt)2722 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2723 {
2724 int error = 0;
2725 int optlen;
2726 struct inpcb *inp = sotoinpcb(so);
2727 int level, op, optname;
2728
2729 if (sopt) {
2730 level = sopt->sopt_level;
2731 op = sopt->sopt_dir;
2732 optname = sopt->sopt_name;
2733 optlen = sopt->sopt_valsize;
2734 } else
2735 level = op = optname = optlen = 0;
2736
2737 if (level != IPPROTO_ICMPV6) {
2738 return EINVAL;
2739 }
2740
2741 switch (op) {
2742 case PRCO_SETOPT:
2743 switch (optname) {
2744 case ICMP6_FILTER:
2745 {
2746 struct icmp6_filter ic6f;
2747
2748 if (optlen != sizeof(ic6f)) {
2749 error = EMSGSIZE;
2750 break;
2751 }
2752 error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2753 if (error == 0) {
2754 INP_WLOCK(inp);
2755 *inp->in6p_icmp6filt = ic6f;
2756 INP_WUNLOCK(inp);
2757 }
2758 break;
2759 }
2760
2761 default:
2762 error = ENOPROTOOPT;
2763 break;
2764 }
2765 break;
2766
2767 case PRCO_GETOPT:
2768 switch (optname) {
2769 case ICMP6_FILTER:
2770 {
2771 struct icmp6_filter ic6f;
2772
2773 INP_RLOCK(inp);
2774 ic6f = *inp->in6p_icmp6filt;
2775 INP_RUNLOCK(inp);
2776 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2777 break;
2778 }
2779
2780 default:
2781 error = ENOPROTOOPT;
2782 break;
2783 }
2784 break;
2785 }
2786
2787 return (error);
2788 }
2789
2790 /*
2791 * Perform rate limit check.
2792 * Returns 0 if it is okay to send the icmp6 packet.
2793 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2794 * limitation.
2795 *
2796 * XXX per-destination/type check necessary?
2797 *
2798 * dst - not used at this moment
2799 * type - not used at this moment
2800 * code - not used at this moment
2801 */
2802 static int
icmp6_ratelimit(const struct in6_addr * dst,const int type,const int code)2803 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2804 const int code)
2805 {
2806 int ret;
2807
2808 ret = 0; /* okay to send */
2809
2810 /* PPS limit */
2811 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2812 V_icmp6errppslim)) {
2813 /* The packet is subject to rate limit */
2814 ret++;
2815 }
2816
2817 return ret;
2818 }
2819