FreeBSD/Linux Kernel Cross Reference
sys/netinet6/icmp6.c
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: releng/12.0/sys/netinet6/icmp6.c 338831 2018-09-20 15:45:53Z bz $");
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
160 kmod_icmp6stat_inc(int statnum)
161 {
162
163 counter_u64_add(VNET(icmp6stat)[statnum], 1);
164 }
165
166 static void
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
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
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
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
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
900 /* Detect the upper level protocol */
901 {
902 void (*ctlfunc)(int, struct sockaddr *, void *);
903 u_int8_t nxt = eip6->ip6_nxt;
904 int eoff = off + sizeof(struct icmp6_hdr) +
905 sizeof(struct ip6_hdr);
906 struct ip6ctlparam ip6cp;
907 struct in6_addr *finaldst = NULL;
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 finaldst = (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 bzero(&icmp6dst, sizeof(icmp6dst));
1056 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1057 icmp6dst.sin6_family = AF_INET6;
1058 if (finaldst == NULL)
1059 icmp6dst.sin6_addr = eip6->ip6_dst;
1060 else
1061 icmp6dst.sin6_addr = *finaldst;
1062 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1063 goto freeit;
1064 bzero(&icmp6src, sizeof(icmp6src));
1065 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1066 icmp6src.sin6_family = AF_INET6;
1067 icmp6src.sin6_addr = eip6->ip6_src;
1068 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1069 goto freeit;
1070 icmp6src.sin6_flowinfo =
1071 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1072
1073 if (finaldst == NULL)
1074 finaldst = &eip6->ip6_dst;
1075 ip6cp.ip6c_m = m;
1076 ip6cp.ip6c_icmp6 = icmp6;
1077 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1078 ip6cp.ip6c_off = eoff;
1079 ip6cp.ip6c_finaldst = finaldst;
1080 ip6cp.ip6c_src = &icmp6src;
1081 ip6cp.ip6c_nxt = nxt;
1082
1083 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1084 notifymtu = ntohl(icmp6->icmp6_mtu);
1085 ip6cp.ip6c_cmdarg = (void *)¬ifymtu;
1086 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/
1087 }
1088
1089 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1090 (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1091 if (ctlfunc) {
1092 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1093 &ip6cp);
1094 }
1095 }
1096 *mp = m;
1097 return (0);
1098
1099 freeit:
1100 m_freem(m);
1101 return (-1);
1102 }
1103
1104 void
1105 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1106 {
1107 struct in6_addr *dst = ip6cp->ip6c_finaldst;
1108 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1109 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1110 u_int mtu = ntohl(icmp6->icmp6_mtu);
1111 struct in_conninfo inc;
1112
1113 #if 0
1114 /*
1115 * RFC2460 section 5, last paragraph.
1116 * even though minimum link MTU for IPv6 is IPV6_MMTU,
1117 * we may see ICMPv6 too big with mtu < IPV6_MMTU
1118 * due to packet translator in the middle.
1119 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1120 * special handling.
1121 */
1122 if (mtu < IPV6_MMTU)
1123 return;
1124 #endif
1125
1126 /*
1127 * we reject ICMPv6 too big with abnormally small value.
1128 * XXX what is the good definition of "abnormally small"?
1129 */
1130 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1131 return;
1132
1133 if (!validated)
1134 return;
1135
1136 /*
1137 * In case the suggested mtu is less than IPV6_MMTU, we
1138 * only need to remember that it was for above mentioned
1139 * "alwaysfrag" case.
1140 * Try to be as close to the spec as possible.
1141 */
1142 if (mtu < IPV6_MMTU)
1143 mtu = IPV6_MMTU - 8;
1144
1145 bzero(&inc, sizeof(inc));
1146 inc.inc_fibnum = M_GETFIB(m);
1147 inc.inc_flags |= INC_ISIPV6;
1148 inc.inc6_faddr = *dst;
1149 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1150 return;
1151
1152 if (mtu < tcp_maxmtu6(&inc, NULL)) {
1153 tcp_hc_updatemtu(&inc, mtu);
1154 ICMP6STAT_INC(icp6s_pmtuchg);
1155 }
1156 }
1157
1158 /*
1159 * Process a Node Information Query packet, based on
1160 * draft-ietf-ipngwg-icmp-name-lookups-07.
1161 *
1162 * Spec incompatibilities:
1163 * - IPv6 Subject address handling
1164 * - IPv4 Subject address handling support missing
1165 * - Proxy reply (answer even if it's not for me)
1166 * - joins NI group address at in6_ifattach() time only, does not cope
1167 * with hostname changes by sethostname(3)
1168 */
1169 static struct mbuf *
1170 ni6_input(struct mbuf *m, int off)
1171 {
1172 struct icmp6_nodeinfo *ni6, *nni6;
1173 struct mbuf *n = NULL;
1174 struct prison *pr;
1175 u_int16_t qtype;
1176 int subjlen;
1177 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1178 struct ni_reply_fqdn *fqdn;
1179 int addrs; /* for NI_QTYPE_NODEADDR */
1180 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1181 struct in6_addr in6_subj; /* subject address */
1182 struct ip6_hdr *ip6;
1183 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */
1184 char *subj = NULL;
1185 struct in6_ifaddr *ia6 = NULL;
1186
1187 ip6 = mtod(m, struct ip6_hdr *);
1188 #ifndef PULLDOWN_TEST
1189 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1190 #else
1191 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1192 if (ni6 == NULL) {
1193 /* m is already reclaimed */
1194 return (NULL);
1195 }
1196 #endif
1197
1198 /*
1199 * Validate IPv6 source address.
1200 * The default configuration MUST be to refuse answering queries from
1201 * global-scope addresses according to RFC4602.
1202 * Notes:
1203 * - it's not very clear what "refuse" means; this implementation
1204 * simply drops it.
1205 * - it's not very easy to identify global-scope (unicast) addresses
1206 * since there are many prefixes for them. It should be safer
1207 * and in practice sufficient to check "all" but loopback and
1208 * link-local (note that site-local unicast was deprecated and
1209 * ULA is defined as global scope-wise)
1210 */
1211 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1212 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1213 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1214 goto bad;
1215
1216 /*
1217 * Validate IPv6 destination address.
1218 *
1219 * The Responder must discard the Query without further processing
1220 * unless it is one of the Responder's unicast or anycast addresses, or
1221 * a link-local scope multicast address which the Responder has joined.
1222 * [RFC4602, Section 5.]
1223 */
1224 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1225 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1226 goto bad;
1227 /* else it's a link-local multicast, fine */
1228 } else { /* unicast or anycast */
1229 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
1230 if (ia6 == NULL)
1231 goto bad; /* XXX impossible */
1232
1233 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1234 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1235 ifa_free(&ia6->ia_ifa);
1236 nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1237 "a temporary address in %s:%d",
1238 __FILE__, __LINE__));
1239 goto bad;
1240 }
1241 ifa_free(&ia6->ia_ifa);
1242 }
1243
1244 /* validate query Subject field. */
1245 qtype = ntohs(ni6->ni_qtype);
1246 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1247 switch (qtype) {
1248 case NI_QTYPE_NOOP:
1249 case NI_QTYPE_SUPTYPES:
1250 /* 07 draft */
1251 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1252 break;
1253 /* FALLTHROUGH */
1254 case NI_QTYPE_FQDN:
1255 case NI_QTYPE_NODEADDR:
1256 case NI_QTYPE_IPV4ADDR:
1257 switch (ni6->ni_code) {
1258 case ICMP6_NI_SUBJ_IPV6:
1259 #if ICMP6_NI_SUBJ_IPV6 != 0
1260 case 0:
1261 #endif
1262 /*
1263 * backward compatibility - try to accept 03 draft
1264 * format, where no Subject is present.
1265 */
1266 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1267 subjlen == 0) {
1268 oldfqdn++;
1269 break;
1270 }
1271 #if ICMP6_NI_SUBJ_IPV6 != 0
1272 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1273 goto bad;
1274 #endif
1275
1276 if (subjlen != sizeof(struct in6_addr))
1277 goto bad;
1278
1279 /*
1280 * Validate Subject address.
1281 *
1282 * Not sure what exactly "address belongs to the node"
1283 * means in the spec, is it just unicast, or what?
1284 *
1285 * At this moment we consider Subject address as
1286 * "belong to the node" if the Subject address equals
1287 * to the IPv6 destination address; validation for
1288 * IPv6 destination address should have done enough
1289 * check for us.
1290 *
1291 * We do not do proxy at this moment.
1292 */
1293 /* m_pulldown instead of copy? */
1294 m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1295 subjlen, (caddr_t)&in6_subj);
1296 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1297 goto bad;
1298
1299 subj = (char *)&in6_subj;
1300 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1301 break;
1302
1303 /*
1304 * XXX if we are to allow other cases, we should really
1305 * be careful about scope here.
1306 * basically, we should disallow queries toward IPv6
1307 * destination X with subject Y,
1308 * if scope(X) > scope(Y).
1309 * if we allow scope(X) > scope(Y), it will result in
1310 * information leakage across scope boundary.
1311 */
1312 goto bad;
1313
1314 case ICMP6_NI_SUBJ_FQDN:
1315 /*
1316 * Validate Subject name with gethostname(3).
1317 *
1318 * The behavior may need some debate, since:
1319 * - we are not sure if the node has FQDN as
1320 * hostname (returned by gethostname(3)).
1321 * - the code does wildcard match for truncated names.
1322 * however, we are not sure if we want to perform
1323 * wildcard match, if gethostname(3) side has
1324 * truncated hostname.
1325 */
1326 pr = curthread->td_ucred->cr_prison;
1327 mtx_lock(&pr->pr_mtx);
1328 n = ni6_nametodns(pr->pr_hostname,
1329 strlen(pr->pr_hostname), 0);
1330 mtx_unlock(&pr->pr_mtx);
1331 if (!n || n->m_next || n->m_len == 0)
1332 goto bad;
1333 IP6_EXTHDR_GET(subj, char *, m,
1334 off + sizeof(struct icmp6_nodeinfo), subjlen);
1335 if (subj == NULL)
1336 goto bad;
1337 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1338 n->m_len)) {
1339 goto bad;
1340 }
1341 m_freem(n);
1342 n = NULL;
1343 break;
1344
1345 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */
1346 default:
1347 goto bad;
1348 }
1349 break;
1350 }
1351
1352 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */
1353 switch (qtype) {
1354 case NI_QTYPE_FQDN:
1355 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1356 goto bad;
1357 break;
1358 case NI_QTYPE_NODEADDR:
1359 case NI_QTYPE_IPV4ADDR:
1360 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1361 goto bad;
1362 break;
1363 }
1364
1365 /* guess reply length */
1366 switch (qtype) {
1367 case NI_QTYPE_NOOP:
1368 break; /* no reply data */
1369 case NI_QTYPE_SUPTYPES:
1370 replylen += sizeof(u_int32_t);
1371 break;
1372 case NI_QTYPE_FQDN:
1373 /* XXX will append an mbuf */
1374 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1375 break;
1376 case NI_QTYPE_NODEADDR:
1377 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1378 if ((replylen += addrs * (sizeof(struct in6_addr) +
1379 sizeof(u_int32_t))) > MCLBYTES)
1380 replylen = MCLBYTES; /* XXX: will truncate pkt later */
1381 break;
1382 case NI_QTYPE_IPV4ADDR:
1383 /* unsupported - should respond with unknown Qtype? */
1384 break;
1385 default:
1386 /*
1387 * XXX: We must return a reply with the ICMP6 code
1388 * `unknown Qtype' in this case. However we regard the case
1389 * as an FQDN query for backward compatibility.
1390 * Older versions set a random value to this field,
1391 * so it rarely varies in the defined qtypes.
1392 * But the mechanism is not reliable...
1393 * maybe we should obsolete older versions.
1394 */
1395 qtype = NI_QTYPE_FQDN;
1396 /* XXX will append an mbuf */
1397 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1398 oldfqdn++;
1399 break;
1400 }
1401
1402 /* Allocate an mbuf to reply. */
1403 if (replylen > MCLBYTES) {
1404 /*
1405 * XXX: should we try to allocate more? But MCLBYTES
1406 * is probably much larger than IPV6_MMTU...
1407 */
1408 goto bad;
1409 }
1410 if (replylen > MHLEN)
1411 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR);
1412 else
1413 n = m_gethdr(M_NOWAIT, m->m_type);
1414 if (n == NULL) {
1415 m_freem(m);
1416 return (NULL);
1417 }
1418 m_move_pkthdr(n, m); /* just for recvif and FIB */
1419 n->m_pkthdr.len = n->m_len = replylen;
1420
1421 /* copy mbuf header and IPv6 + Node Information base headers */
1422 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1423 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1424 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1425
1426 /* qtype dependent procedure */
1427 switch (qtype) {
1428 case NI_QTYPE_NOOP:
1429 nni6->ni_code = ICMP6_NI_SUCCESS;
1430 nni6->ni_flags = 0;
1431 break;
1432 case NI_QTYPE_SUPTYPES:
1433 {
1434 u_int32_t v;
1435 nni6->ni_code = ICMP6_NI_SUCCESS;
1436 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1437 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1438 v = (u_int32_t)htonl(0x0000000f);
1439 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1440 break;
1441 }
1442 case NI_QTYPE_FQDN:
1443 nni6->ni_code = ICMP6_NI_SUCCESS;
1444 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1445 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1446 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1447 fqdn->ni_fqdn_ttl = 0; /* ditto. */
1448 /*
1449 * XXX do we really have FQDN in hostname?
1450 */
1451 pr = curthread->td_ucred->cr_prison;
1452 mtx_lock(&pr->pr_mtx);
1453 n->m_next = ni6_nametodns(pr->pr_hostname,
1454 strlen(pr->pr_hostname), oldfqdn);
1455 mtx_unlock(&pr->pr_mtx);
1456 if (n->m_next == NULL)
1457 goto bad;
1458 /* XXX we assume that n->m_next is not a chain */
1459 if (n->m_next->m_next != NULL)
1460 goto bad;
1461 n->m_pkthdr.len += n->m_next->m_len;
1462 break;
1463 case NI_QTYPE_NODEADDR:
1464 {
1465 int lenlim, copied;
1466
1467 nni6->ni_code = ICMP6_NI_SUCCESS;
1468 n->m_pkthdr.len = n->m_len =
1469 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1470 lenlim = M_TRAILINGSPACE(n);
1471 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1472 /* XXX: reset mbuf length */
1473 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1474 sizeof(struct icmp6_nodeinfo) + copied;
1475 break;
1476 }
1477 default:
1478 break; /* XXX impossible! */
1479 }
1480
1481 nni6->ni_type = ICMP6_NI_REPLY;
1482 m_freem(m);
1483 return (n);
1484
1485 bad:
1486 m_freem(m);
1487 if (n)
1488 m_freem(n);
1489 return (NULL);
1490 }
1491
1492 /*
1493 * make a mbuf with DNS-encoded string. no compression support.
1494 *
1495 * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1496 * treated as truncated name (two \0 at the end). this is a wild guess.
1497 *
1498 * old - return pascal string if non-zero
1499 */
1500 static struct mbuf *
1501 ni6_nametodns(const char *name, int namelen, int old)
1502 {
1503 struct mbuf *m;
1504 char *cp, *ep;
1505 const char *p, *q;
1506 int i, len, nterm;
1507
1508 if (old)
1509 len = namelen + 1;
1510 else
1511 len = MCLBYTES;
1512
1513 /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */
1514 if (len > MLEN)
1515 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1516 else
1517 m = m_get(M_NOWAIT, MT_DATA);
1518 if (m == NULL)
1519 goto fail;
1520
1521 if (old) {
1522 m->m_len = len;
1523 *mtod(m, char *) = namelen;
1524 bcopy(name, mtod(m, char *) + 1, namelen);
1525 return m;
1526 } else {
1527 m->m_len = 0;
1528 cp = mtod(m, char *);
1529 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1530
1531 /* if not certain about my name, return empty buffer */
1532 if (namelen == 0)
1533 return m;
1534
1535 /*
1536 * guess if it looks like shortened hostname, or FQDN.
1537 * shortened hostname needs two trailing "\0".
1538 */
1539 i = 0;
1540 for (p = name; p < name + namelen; p++) {
1541 if (*p && *p == '.')
1542 i++;
1543 }
1544 if (i < 2)
1545 nterm = 2;
1546 else
1547 nterm = 1;
1548
1549 p = name;
1550 while (cp < ep && p < name + namelen) {
1551 i = 0;
1552 for (q = p; q < name + namelen && *q && *q != '.'; q++)
1553 i++;
1554 /* result does not fit into mbuf */
1555 if (cp + i + 1 >= ep)
1556 goto fail;
1557 /*
1558 * DNS label length restriction, RFC1035 page 8.
1559 * "i == 0" case is included here to avoid returning
1560 * 0-length label on "foo..bar".
1561 */
1562 if (i <= 0 || i >= 64)
1563 goto fail;
1564 *cp++ = i;
1565 bcopy(p, cp, i);
1566 cp += i;
1567 p = q;
1568 if (p < name + namelen && *p == '.')
1569 p++;
1570 }
1571 /* termination */
1572 if (cp + nterm >= ep)
1573 goto fail;
1574 while (nterm-- > 0)
1575 *cp++ = '\0';
1576 m->m_len = cp - mtod(m, char *);
1577 return m;
1578 }
1579
1580 panic("should not reach here");
1581 /* NOTREACHED */
1582
1583 fail:
1584 if (m)
1585 m_freem(m);
1586 return NULL;
1587 }
1588
1589 /*
1590 * check if two DNS-encoded string matches. takes care of truncated
1591 * form (with \0\0 at the end). no compression support.
1592 * XXX upper/lowercase match (see RFC2065)
1593 */
1594 static int
1595 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1596 {
1597 const char *a0, *b0;
1598 int l;
1599
1600 /* simplest case - need validation? */
1601 if (alen == blen && bcmp(a, b, alen) == 0)
1602 return 1;
1603
1604 a0 = a;
1605 b0 = b;
1606
1607 /* termination is mandatory */
1608 if (alen < 2 || blen < 2)
1609 return 0;
1610 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1611 return 0;
1612 alen--;
1613 blen--;
1614
1615 while (a - a0 < alen && b - b0 < blen) {
1616 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1617 return 0;
1618
1619 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1620 return 0;
1621 /* we don't support compression yet */
1622 if (a[0] >= 64 || b[0] >= 64)
1623 return 0;
1624
1625 /* truncated case */
1626 if (a[0] == 0 && a - a0 == alen - 1)
1627 return 1;
1628 if (b[0] == 0 && b - b0 == blen - 1)
1629 return 1;
1630 if (a[0] == 0 || b[0] == 0)
1631 return 0;
1632
1633 if (a[0] != b[0])
1634 return 0;
1635 l = a[0];
1636 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1637 return 0;
1638 if (bcmp(a + 1, b + 1, l) != 0)
1639 return 0;
1640
1641 a += 1 + l;
1642 b += 1 + l;
1643 }
1644
1645 if (a - a0 == alen && b - b0 == blen)
1646 return 1;
1647 else
1648 return 0;
1649 }
1650
1651 /*
1652 * calculate the number of addresses to be returned in the node info reply.
1653 */
1654 static int
1655 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1656 struct in6_addr *subj)
1657 {
1658 struct ifnet *ifp;
1659 struct in6_ifaddr *ifa6;
1660 struct ifaddr *ifa;
1661 int addrs = 0, addrsofif, iffound = 0;
1662 int niflags = ni6->ni_flags;
1663
1664 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1665 switch (ni6->ni_code) {
1666 case ICMP6_NI_SUBJ_IPV6:
1667 if (subj == NULL) /* must be impossible... */
1668 return (0);
1669 break;
1670 default:
1671 /*
1672 * XXX: we only support IPv6 subject address for
1673 * this Qtype.
1674 */
1675 return (0);
1676 }
1677 }
1678
1679 IFNET_RLOCK_NOSLEEP();
1680 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1681 addrsofif = 0;
1682 IF_ADDR_RLOCK(ifp);
1683 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1684 if (ifa->ifa_addr->sa_family != AF_INET6)
1685 continue;
1686 ifa6 = (struct in6_ifaddr *)ifa;
1687
1688 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1689 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1690 iffound = 1;
1691
1692 /*
1693 * IPv4-mapped addresses can only be returned by a
1694 * Node Information proxy, since they represent
1695 * addresses of IPv4-only nodes, which perforce do
1696 * not implement this protocol.
1697 * [icmp-name-lookups-07, Section 5.4]
1698 * So we don't support NI_NODEADDR_FLAG_COMPAT in
1699 * this function at this moment.
1700 */
1701
1702 /* What do we have to do about ::1? */
1703 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1704 case IPV6_ADDR_SCOPE_LINKLOCAL:
1705 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1706 continue;
1707 break;
1708 case IPV6_ADDR_SCOPE_SITELOCAL:
1709 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1710 continue;
1711 break;
1712 case IPV6_ADDR_SCOPE_GLOBAL:
1713 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1714 continue;
1715 break;
1716 default:
1717 continue;
1718 }
1719
1720 /*
1721 * check if anycast is okay.
1722 * XXX: just experimental. not in the spec.
1723 */
1724 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1725 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1726 continue; /* we need only unicast addresses */
1727 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1728 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1729 continue;
1730 }
1731 addrsofif++; /* count the address */
1732 }
1733 IF_ADDR_RUNLOCK(ifp);
1734 if (iffound) {
1735 *ifpp = ifp;
1736 IFNET_RUNLOCK_NOSLEEP();
1737 return (addrsofif);
1738 }
1739
1740 addrs += addrsofif;
1741 }
1742 IFNET_RUNLOCK_NOSLEEP();
1743
1744 return (addrs);
1745 }
1746
1747 static int
1748 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1749 struct ifnet *ifp0, int resid)
1750 {
1751 struct ifnet *ifp;
1752 struct in6_ifaddr *ifa6;
1753 struct ifaddr *ifa;
1754 struct ifnet *ifp_dep = NULL;
1755 int copied = 0, allow_deprecated = 0;
1756 u_char *cp = (u_char *)(nni6 + 1);
1757 int niflags = ni6->ni_flags;
1758 u_int32_t ltime;
1759
1760 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1761 return (0); /* needless to copy */
1762
1763 IFNET_RLOCK_NOSLEEP();
1764 ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet);
1765 again:
1766
1767 for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) {
1768 IF_ADDR_RLOCK(ifp);
1769 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1770 if (ifa->ifa_addr->sa_family != AF_INET6)
1771 continue;
1772 ifa6 = (struct in6_ifaddr *)ifa;
1773
1774 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1775 allow_deprecated == 0) {
1776 /*
1777 * prefererred address should be put before
1778 * deprecated addresses.
1779 */
1780
1781 /* record the interface for later search */
1782 if (ifp_dep == NULL)
1783 ifp_dep = ifp;
1784
1785 continue;
1786 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1787 allow_deprecated != 0)
1788 continue; /* we now collect deprecated addrs */
1789
1790 /* What do we have to do about ::1? */
1791 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1792 case IPV6_ADDR_SCOPE_LINKLOCAL:
1793 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1794 continue;
1795 break;
1796 case IPV6_ADDR_SCOPE_SITELOCAL:
1797 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1798 continue;
1799 break;
1800 case IPV6_ADDR_SCOPE_GLOBAL:
1801 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1802 continue;
1803 break;
1804 default:
1805 continue;
1806 }
1807
1808 /*
1809 * check if anycast is okay.
1810 * XXX: just experimental. not in the spec.
1811 */
1812 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1813 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1814 continue;
1815 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1816 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1817 continue;
1818 }
1819
1820 /* now we can copy the address */
1821 if (resid < sizeof(struct in6_addr) +
1822 sizeof(u_int32_t)) {
1823 IF_ADDR_RUNLOCK(ifp);
1824 /*
1825 * We give up much more copy.
1826 * Set the truncate flag and return.
1827 */
1828 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1829 IFNET_RUNLOCK_NOSLEEP();
1830 return (copied);
1831 }
1832
1833 /*
1834 * Set the TTL of the address.
1835 * The TTL value should be one of the following
1836 * according to the specification:
1837 *
1838 * 1. The remaining lifetime of a DHCP lease on the
1839 * address, or
1840 * 2. The remaining Valid Lifetime of a prefix from
1841 * which the address was derived through Stateless
1842 * Autoconfiguration.
1843 *
1844 * Note that we currently do not support stateful
1845 * address configuration by DHCPv6, so the former
1846 * case can't happen.
1847 */
1848 if (ifa6->ia6_lifetime.ia6t_expire == 0)
1849 ltime = ND6_INFINITE_LIFETIME;
1850 else {
1851 if (ifa6->ia6_lifetime.ia6t_expire >
1852 time_uptime)
1853 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime);
1854 else
1855 ltime = 0;
1856 }
1857
1858 bcopy(<ime, cp, sizeof(u_int32_t));
1859 cp += sizeof(u_int32_t);
1860
1861 /* copy the address itself */
1862 bcopy(&ifa6->ia_addr.sin6_addr, cp,
1863 sizeof(struct in6_addr));
1864 in6_clearscope((struct in6_addr *)cp); /* XXX */
1865 cp += sizeof(struct in6_addr);
1866
1867 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1868 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1869 }
1870 IF_ADDR_RUNLOCK(ifp);
1871 if (ifp0) /* we need search only on the specified IF */
1872 break;
1873 }
1874
1875 if (allow_deprecated == 0 && ifp_dep != NULL) {
1876 ifp = ifp_dep;
1877 allow_deprecated = 1;
1878
1879 goto again;
1880 }
1881
1882 IFNET_RUNLOCK_NOSLEEP();
1883
1884 return (copied);
1885 }
1886
1887 /*
1888 * XXX almost dup'ed code with rip6_input.
1889 */
1890 static int
1891 icmp6_rip6_input(struct mbuf **mp, int off)
1892 {
1893 struct mbuf *m = *mp;
1894 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1895 struct inpcb *in6p;
1896 struct inpcb *last = NULL;
1897 struct sockaddr_in6 fromsa;
1898 struct icmp6_hdr *icmp6;
1899 struct epoch_tracker et;
1900 struct mbuf *opts = NULL;
1901
1902 #ifndef PULLDOWN_TEST
1903 /* this is assumed to be safe. */
1904 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1905 #else
1906 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1907 if (icmp6 == NULL) {
1908 /* m is already reclaimed */
1909 return (IPPROTO_DONE);
1910 }
1911 #endif
1912
1913 /*
1914 * XXX: the address may have embedded scope zone ID, which should be
1915 * hidden from applications.
1916 */
1917 bzero(&fromsa, sizeof(fromsa));
1918 fromsa.sin6_family = AF_INET6;
1919 fromsa.sin6_len = sizeof(struct sockaddr_in6);
1920 fromsa.sin6_addr = ip6->ip6_src;
1921 if (sa6_recoverscope(&fromsa)) {
1922 m_freem(m);
1923 return (IPPROTO_DONE);
1924 }
1925
1926 INP_INFO_RLOCK_ET(&V_ripcbinfo, et);
1927 CK_LIST_FOREACH(in6p, &V_ripcb, inp_list) {
1928 if ((in6p->inp_vflag & INP_IPV6) == 0)
1929 continue;
1930 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
1931 continue;
1932 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1933 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1934 continue;
1935 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1936 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1937 continue;
1938 INP_RLOCK(in6p);
1939 if (__predict_false(in6p->inp_flags2 & INP_FREED)) {
1940 INP_RUNLOCK(in6p);
1941 continue;
1942 }
1943 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1944 in6p->in6p_icmp6filt)) {
1945 INP_RUNLOCK(in6p);
1946 continue;
1947 }
1948 if (last != NULL) {
1949 struct mbuf *n = NULL;
1950
1951 /*
1952 * Recent network drivers tend to allocate a single
1953 * mbuf cluster, rather than to make a couple of
1954 * mbufs without clusters. Also, since the IPv6 code
1955 * path tries to avoid m_pullup(), it is highly
1956 * probable that we still have an mbuf cluster here
1957 * even though the necessary length can be stored in an
1958 * mbuf's internal buffer.
1959 * Meanwhile, the default size of the receive socket
1960 * buffer for raw sockets is not so large. This means
1961 * the possibility of packet loss is relatively higher
1962 * than before. To avoid this scenario, we copy the
1963 * received data to a separate mbuf that does not use
1964 * a cluster, if possible.
1965 * XXX: it is better to copy the data after stripping
1966 * intermediate headers.
1967 */
1968 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1969 m->m_len <= MHLEN) {
1970 n = m_get(M_NOWAIT, m->m_type);
1971 if (n != NULL) {
1972 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1973 bcopy(m->m_data, n->m_data,
1974 m->m_len);
1975 n->m_len = m->m_len;
1976 } else {
1977 m_free(n);
1978 n = NULL;
1979 }
1980 }
1981 }
1982 if (n != NULL ||
1983 (n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) {
1984 if (last->inp_flags & INP_CONTROLOPTS)
1985 ip6_savecontrol(last, n, &opts);
1986 /* strip intermediate headers */
1987 m_adj(n, off);
1988 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
1989 if (sbappendaddr_locked(
1990 &last->inp_socket->so_rcv,
1991 (struct sockaddr *)&fromsa, n, opts)
1992 == 0) {
1993 /* should notify about lost packet */
1994 m_freem(n);
1995 if (opts) {
1996 m_freem(opts);
1997 }
1998 SOCKBUF_UNLOCK(
1999 &last->inp_socket->so_rcv);
2000 } else
2001 sorwakeup_locked(last->inp_socket);
2002 opts = NULL;
2003 }
2004 INP_RUNLOCK(last);
2005 }
2006 last = in6p;
2007 }
2008 INP_INFO_RUNLOCK_ET(&V_ripcbinfo, et);
2009 if (last != NULL) {
2010 if (last->inp_flags & INP_CONTROLOPTS)
2011 ip6_savecontrol(last, m, &opts);
2012 /* strip intermediate headers */
2013 m_adj(m, off);
2014
2015 /* avoid using mbuf clusters if possible (see above) */
2016 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2017 m->m_len <= MHLEN) {
2018 struct mbuf *n;
2019
2020 n = m_get(M_NOWAIT, m->m_type);
2021 if (n != NULL) {
2022 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2023 bcopy(m->m_data, n->m_data, m->m_len);
2024 n->m_len = m->m_len;
2025
2026 m_freem(m);
2027 m = n;
2028 } else {
2029 m_freem(n);
2030 n = NULL;
2031 }
2032 }
2033 }
2034 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2035 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
2036 (struct sockaddr *)&fromsa, m, opts) == 0) {
2037 m_freem(m);
2038 if (opts)
2039 m_freem(opts);
2040 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
2041 } else
2042 sorwakeup_locked(last->inp_socket);
2043 INP_RUNLOCK(last);
2044 } else {
2045 m_freem(m);
2046 IP6STAT_DEC(ip6s_delivered);
2047 }
2048 return IPPROTO_DONE;
2049 }
2050
2051 /*
2052 * Reflect the ip6 packet back to the source.
2053 * OFF points to the icmp6 header, counted from the top of the mbuf.
2054 */
2055 void
2056 icmp6_reflect(struct mbuf *m, size_t off)
2057 {
2058 struct in6_addr src6, *srcp;
2059 struct ip6_hdr *ip6;
2060 struct icmp6_hdr *icmp6;
2061 struct in6_ifaddr *ia = NULL;
2062 struct ifnet *outif = NULL;
2063 int plen;
2064 int type, code, hlim;
2065
2066 /* too short to reflect */
2067 if (off < sizeof(struct ip6_hdr)) {
2068 nd6log((LOG_DEBUG,
2069 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2070 (u_long)off, (u_long)sizeof(struct ip6_hdr),
2071 __FILE__, __LINE__));
2072 goto bad;
2073 }
2074
2075 /*
2076 * If there are extra headers between IPv6 and ICMPv6, strip
2077 * off that header first.
2078 */
2079 #ifdef DIAGNOSTIC
2080 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2081 panic("assumption failed in icmp6_reflect");
2082 #endif
2083 if (off > sizeof(struct ip6_hdr)) {
2084 size_t l;
2085 struct ip6_hdr nip6;
2086
2087 l = off - sizeof(struct ip6_hdr);
2088 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2089 m_adj(m, l);
2090 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2091 if (m->m_len < l) {
2092 if ((m = m_pullup(m, l)) == NULL)
2093 return;
2094 }
2095 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2096 } else /* off == sizeof(struct ip6_hdr) */ {
2097 size_t l;
2098 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2099 if (m->m_len < l) {
2100 if ((m = m_pullup(m, l)) == NULL)
2101 return;
2102 }
2103 }
2104 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2105 ip6 = mtod(m, struct ip6_hdr *);
2106 ip6->ip6_nxt = IPPROTO_ICMPV6;
2107 icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2108 type = icmp6->icmp6_type; /* keep type for statistics */
2109 code = icmp6->icmp6_code; /* ditto. */
2110 hlim = 0;
2111 srcp = NULL;
2112
2113 /*
2114 * If the incoming packet was addressed directly to us (i.e. unicast),
2115 * use dst as the src for the reply.
2116 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2117 * (for example) when we encounter an error while forwarding procedure
2118 * destined to a duplicated address of ours.
2119 */
2120 if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
2121 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
2122 if (ia != NULL && !(ia->ia6_flags &
2123 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2124 src6 = ia->ia_addr.sin6_addr;
2125 srcp = &src6;
2126
2127 if (m->m_pkthdr.rcvif != NULL) {
2128 /* XXX: This may not be the outgoing interface */
2129 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2130 } else
2131 hlim = V_ip6_defhlim;
2132 }
2133 if (ia != NULL)
2134 ifa_free(&ia->ia_ifa);
2135 }
2136
2137 if (srcp == NULL) {
2138 int error;
2139 struct in6_addr dst6;
2140 uint32_t scopeid;
2141
2142 /*
2143 * This case matches to multicasts, our anycast, or unicasts
2144 * that we do not own. Select a source address based on the
2145 * source address of the erroneous packet.
2146 */
2147 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid);
2148 error = in6_selectsrc_addr(M_GETFIB(m), &dst6,
2149 scopeid, NULL, &src6, &hlim);
2150
2151 if (error) {
2152 char ip6buf[INET6_ADDRSTRLEN];
2153 nd6log((LOG_DEBUG,
2154 "icmp6_reflect: source can't be determined: "
2155 "dst=%s, error=%d\n",
2156 ip6_sprintf(ip6buf, &ip6->ip6_dst), error));
2157 goto bad;
2158 }
2159 srcp = &src6;
2160 }
2161 /*
2162 * ip6_input() drops a packet if its src is multicast.
2163 * So, the src is never multicast.
2164 */
2165 ip6->ip6_dst = ip6->ip6_src;
2166 ip6->ip6_src = *srcp;
2167 ip6->ip6_flow = 0;
2168 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2169 ip6->ip6_vfc |= IPV6_VERSION;
2170 ip6->ip6_nxt = IPPROTO_ICMPV6;
2171 ip6->ip6_hlim = hlim;
2172
2173 icmp6->icmp6_cksum = 0;
2174 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2175 sizeof(struct ip6_hdr), plen);
2176
2177 /*
2178 * XXX option handling
2179 */
2180
2181 m->m_flags &= ~(M_BCAST|M_MCAST);
2182 m->m_pkthdr.rcvif = NULL;
2183 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2184 if (outif)
2185 icmp6_ifoutstat_inc(outif, type, code);
2186
2187 return;
2188
2189 bad:
2190 m_freem(m);
2191 return;
2192 }
2193
2194 void
2195 icmp6_fasttimo(void)
2196 {
2197
2198 mld_fasttimo();
2199 }
2200
2201 void
2202 icmp6_slowtimo(void)
2203 {
2204
2205 mld_slowtimo();
2206 }
2207
2208 static const char *
2209 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2210 struct in6_addr *tgt6)
2211 {
2212 static char buf[1024];
2213 char ip6bufs[INET6_ADDRSTRLEN];
2214 char ip6bufd[INET6_ADDRSTRLEN];
2215 char ip6buft[INET6_ADDRSTRLEN];
2216 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2217 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2218 ip6_sprintf(ip6buft, tgt6));
2219 return buf;
2220 }
2221
2222 void
2223 icmp6_redirect_input(struct mbuf *m, int off)
2224 {
2225 struct ifnet *ifp;
2226 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2227 struct nd_redirect *nd_rd;
2228 int icmp6len = ntohs(ip6->ip6_plen);
2229 char *lladdr = NULL;
2230 int lladdrlen = 0;
2231 int is_router;
2232 int is_onlink;
2233 struct in6_addr src6 = ip6->ip6_src;
2234 struct in6_addr redtgt6;
2235 struct in6_addr reddst6;
2236 union nd_opts ndopts;
2237 char ip6buf[INET6_ADDRSTRLEN];
2238
2239 M_ASSERTPKTHDR(m);
2240 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__));
2241
2242 ifp = m->m_pkthdr.rcvif;
2243
2244 /* XXX if we are router, we don't update route by icmp6 redirect */
2245 if (V_ip6_forwarding)
2246 goto freeit;
2247 if (!V_icmp6_rediraccept)
2248 goto freeit;
2249
2250 /* RFC 6980: Nodes MUST silently ignore fragments */
2251 if(m->m_flags & M_FRAGMENTED)
2252 goto freeit;
2253
2254 #ifndef PULLDOWN_TEST
2255 IP6_EXTHDR_CHECK(m, off, icmp6len,);
2256 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2257 #else
2258 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2259 if (nd_rd == NULL) {
2260 ICMP6STAT_INC(icp6s_tooshort);
2261 return;
2262 }
2263 #endif
2264 redtgt6 = nd_rd->nd_rd_target;
2265 reddst6 = nd_rd->nd_rd_dst;
2266
2267 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2268 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2269 goto freeit;
2270 }
2271
2272 /* validation */
2273 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2274 nd6log((LOG_ERR,
2275 "ICMP6 redirect sent from %s rejected; "
2276 "must be from linklocal\n",
2277 ip6_sprintf(ip6buf, &src6)));
2278 goto bad;
2279 }
2280 if (ip6->ip6_hlim != 255) {
2281 nd6log((LOG_ERR,
2282 "ICMP6 redirect sent from %s rejected; "
2283 "hlim=%d (must be 255)\n",
2284 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2285 goto bad;
2286 }
2287 {
2288 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2289 struct nhop6_basic nh6;
2290 struct in6_addr kdst;
2291 uint32_t scopeid;
2292
2293 in6_splitscope(&reddst6, &kdst, &scopeid);
2294 if (fib6_lookup_nh_basic(ifp->if_fib, &kdst, scopeid, 0, 0,&nh6)==0){
2295 if ((nh6.nh_flags & NHF_GATEWAY) == 0) {
2296 nd6log((LOG_ERR,
2297 "ICMP6 redirect rejected; no route "
2298 "with inet6 gateway found for redirect dst: %s\n",
2299 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2300 goto bad;
2301 }
2302
2303 /*
2304 * Embed scope zone id into next hop address, since
2305 * fib6_lookup_nh_basic() returns address without embedded
2306 * scope zone id.
2307 */
2308 if (in6_setscope(&nh6.nh_addr, m->m_pkthdr.rcvif, NULL))
2309 goto freeit;
2310
2311 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) {
2312 nd6log((LOG_ERR,
2313 "ICMP6 redirect rejected; "
2314 "not equal to gw-for-src=%s (must be same): "
2315 "%s\n",
2316 ip6_sprintf(ip6buf, &nh6.nh_addr),
2317 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2318 goto bad;
2319 }
2320 } else {
2321 nd6log((LOG_ERR,
2322 "ICMP6 redirect rejected; "
2323 "no route found for redirect dst: %s\n",
2324 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2325 goto bad;
2326 }
2327 }
2328 if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2329 nd6log((LOG_ERR,
2330 "ICMP6 redirect rejected; "
2331 "redirect dst must be unicast: %s\n",
2332 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2333 goto bad;
2334 }
2335
2336 is_router = is_onlink = 0;
2337 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2338 is_router = 1; /* router case */
2339 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2340 is_onlink = 1; /* on-link destination case */
2341 if (!is_router && !is_onlink) {
2342 nd6log((LOG_ERR,
2343 "ICMP6 redirect rejected; "
2344 "neither router case nor onlink case: %s\n",
2345 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2346 goto bad;
2347 }
2348
2349 icmp6len -= sizeof(*nd_rd);
2350 nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2351 if (nd6_options(&ndopts) < 0) {
2352 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n",
2353 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2354 /* nd6_options have incremented stats */
2355 goto freeit;
2356 }
2357
2358 if (ndopts.nd_opts_tgt_lladdr) {
2359 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2360 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2361 }
2362
2363 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2364 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s "
2365 "(if %d, icmp6 packet %d): %s\n",
2366 __func__, ip6_sprintf(ip6buf, &redtgt6),
2367 ifp->if_addrlen, lladdrlen - 2,
2368 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2369 goto bad;
2370 }
2371
2372 /* Validation passed. */
2373
2374 /* RFC 2461 8.3 */
2375 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2376 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2377
2378 /*
2379 * Install a gateway route in the better-router case or an interface
2380 * route in the on-link-destination case.
2381 */
2382 {
2383 struct sockaddr_in6 sdst;
2384 struct sockaddr_in6 sgw;
2385 struct sockaddr_in6 ssrc;
2386 struct sockaddr *gw;
2387 int rt_flags;
2388 u_int fibnum;
2389
2390 bzero(&sdst, sizeof(sdst));
2391 bzero(&ssrc, sizeof(ssrc));
2392 sdst.sin6_family = ssrc.sin6_family = AF_INET6;
2393 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6);
2394 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2395 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2396 rt_flags = RTF_HOST;
2397 if (is_router) {
2398 bzero(&sgw, sizeof(sgw));
2399 sgw.sin6_family = AF_INET6;
2400 sgw.sin6_len = sizeof(struct sockaddr_in6);
2401 bcopy(&redtgt6, &sgw.sin6_addr,
2402 sizeof(struct in6_addr));
2403 gw = (struct sockaddr *)&sgw;
2404 rt_flags |= RTF_GATEWAY;
2405 } else
2406 gw = ifp->if_addr->ifa_addr;
2407 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
2408 in6_rtredirect((struct sockaddr *)&sdst, gw,
2409 (struct sockaddr *)NULL, rt_flags,
2410 (struct sockaddr *)&ssrc, fibnum);
2411 }
2412 /* finally update cached route in each socket via pfctlinput */
2413 {
2414 struct sockaddr_in6 sdst;
2415
2416 bzero(&sdst, sizeof(sdst));
2417 sdst.sin6_family = AF_INET6;
2418 sdst.sin6_len = sizeof(struct sockaddr_in6);
2419 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2420 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2421 }
2422
2423 freeit:
2424 m_freem(m);
2425 return;
2426
2427 bad:
2428 ICMP6STAT_INC(icp6s_badredirect);
2429 m_freem(m);
2430 }
2431
2432 void
2433 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2434 {
2435 struct ifnet *ifp; /* my outgoing interface */
2436 struct in6_addr *ifp_ll6;
2437 struct in6_addr *router_ll6;
2438 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */
2439 struct mbuf *m = NULL; /* newly allocated one */
2440 struct m_tag *mtag;
2441 struct ip6_hdr *ip6; /* m as struct ip6_hdr */
2442 struct nd_redirect *nd_rd;
2443 struct llentry *ln = NULL;
2444 size_t maxlen;
2445 u_char *p;
2446 struct ifnet *outif = NULL;
2447 struct sockaddr_in6 src_sa;
2448
2449 icmp6_errcount(ND_REDIRECT, 0);
2450
2451 /* if we are not router, we don't send icmp6 redirect */
2452 if (!V_ip6_forwarding)
2453 goto fail;
2454
2455 /* sanity check */
2456 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2457 goto fail;
2458
2459 /*
2460 * Address check:
2461 * the source address must identify a neighbor, and
2462 * the destination address must not be a multicast address
2463 * [RFC 2461, sec 8.2]
2464 */
2465 sip6 = mtod(m0, struct ip6_hdr *);
2466 bzero(&src_sa, sizeof(src_sa));
2467 src_sa.sin6_family = AF_INET6;
2468 src_sa.sin6_len = sizeof(src_sa);
2469 src_sa.sin6_addr = sip6->ip6_src;
2470 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2471 goto fail;
2472 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2473 goto fail; /* what should we do here? */
2474
2475 /* rate limit */
2476 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2477 goto fail;
2478
2479 /*
2480 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2481 * we almost always ask for an mbuf cluster for simplicity.
2482 * (MHLEN < IPV6_MMTU is almost always true)
2483 */
2484 #if IPV6_MMTU >= MCLBYTES
2485 # error assumption failed about IPV6_MMTU and MCLBYTES
2486 #endif
2487 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2488 if (m == NULL)
2489 goto fail;
2490 M_SETFIB(m, rt->rt_fibnum);
2491 maxlen = M_TRAILINGSPACE(m);
2492 maxlen = min(IPV6_MMTU, maxlen);
2493 /* just for safety */
2494 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2495 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2496 goto fail;
2497 }
2498
2499 {
2500 /* get ip6 linklocal address for ifp(my outgoing interface). */
2501 struct in6_ifaddr *ia;
2502 if ((ia = in6ifa_ifpforlinklocal(ifp,
2503 IN6_IFF_NOTREADY|
2504 IN6_IFF_ANYCAST)) == NULL)
2505 goto fail;
2506 ifp_ll6 = &ia->ia_addr.sin6_addr;
2507 /* XXXRW: reference released prematurely. */
2508 ifa_free(&ia->ia_ifa);
2509 }
2510
2511 /* get ip6 linklocal address for the router. */
2512 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2513 struct sockaddr_in6 *sin6;
2514 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2515 router_ll6 = &sin6->sin6_addr;
2516 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2517 router_ll6 = (struct in6_addr *)NULL;
2518 } else
2519 router_ll6 = (struct in6_addr *)NULL;
2520
2521 /* ip6 */
2522 ip6 = mtod(m, struct ip6_hdr *);
2523 ip6->ip6_flow = 0;
2524 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2525 ip6->ip6_vfc |= IPV6_VERSION;
2526 /* ip6->ip6_plen will be set later */
2527 ip6->ip6_nxt = IPPROTO_ICMPV6;
2528 ip6->ip6_hlim = 255;
2529 /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2530 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2531 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2532
2533 /* ND Redirect */
2534 nd_rd = (struct nd_redirect *)(ip6 + 1);
2535 nd_rd->nd_rd_type = ND_REDIRECT;
2536 nd_rd->nd_rd_code = 0;
2537 nd_rd->nd_rd_reserved = 0;
2538 if (rt->rt_flags & RTF_GATEWAY) {
2539 /*
2540 * nd_rd->nd_rd_target must be a link-local address in
2541 * better router cases.
2542 */
2543 if (!router_ll6)
2544 goto fail;
2545 bcopy(router_ll6, &nd_rd->nd_rd_target,
2546 sizeof(nd_rd->nd_rd_target));
2547 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2548 sizeof(nd_rd->nd_rd_dst));
2549 } else {
2550 /* make sure redtgt == reddst */
2551 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2552 sizeof(nd_rd->nd_rd_target));
2553 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2554 sizeof(nd_rd->nd_rd_dst));
2555 }
2556
2557 p = (u_char *)(nd_rd + 1);
2558
2559 if (!router_ll6)
2560 goto nolladdropt;
2561
2562 {
2563 /* target lladdr option */
2564 int len;
2565 struct nd_opt_hdr *nd_opt;
2566 char *lladdr;
2567
2568 IF_AFDATA_RLOCK(ifp);
2569 ln = nd6_lookup(router_ll6, 0, ifp);
2570 IF_AFDATA_RUNLOCK(ifp);
2571 if (ln == NULL)
2572 goto nolladdropt;
2573
2574 len = sizeof(*nd_opt) + ifp->if_addrlen;
2575 len = (len + 7) & ~7; /* round by 8 */
2576 /* safety check */
2577 if (len + (p - (u_char *)ip6) > maxlen)
2578 goto nolladdropt;
2579
2580 if (ln->la_flags & LLE_VALID) {
2581 nd_opt = (struct nd_opt_hdr *)p;
2582 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2583 nd_opt->nd_opt_len = len >> 3;
2584 lladdr = (char *)(nd_opt + 1);
2585 bcopy(ln->ll_addr, lladdr, ifp->if_addrlen);
2586 p += len;
2587 }
2588 }
2589 nolladdropt:
2590 if (ln != NULL)
2591 LLE_RUNLOCK(ln);
2592
2593 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2594
2595 /* just to be safe */
2596 #ifdef M_DECRYPTED /*not openbsd*/
2597 if (m0->m_flags & M_DECRYPTED)
2598 goto noredhdropt;
2599 #endif
2600 if (p - (u_char *)ip6 > maxlen)
2601 goto noredhdropt;
2602
2603 {
2604 /* redirected header option */
2605 int len;
2606 struct nd_opt_rd_hdr *nd_opt_rh;
2607
2608 /*
2609 * compute the maximum size for icmp6 redirect header option.
2610 * XXX room for auth header?
2611 */
2612 len = maxlen - (p - (u_char *)ip6);
2613 len &= ~7;
2614
2615 /* This is just for simplicity. */
2616 if (m0->m_pkthdr.len != m0->m_len) {
2617 if (m0->m_next) {
2618 m_freem(m0->m_next);
2619 m0->m_next = NULL;
2620 }
2621 m0->m_pkthdr.len = m0->m_len;
2622 }
2623
2624 /*
2625 * Redirected header option spec (RFC2461 4.6.3) talks nothing
2626 * about padding/truncate rule for the original IP packet.
2627 * From the discussion on IPv6imp in Feb 1999,
2628 * the consensus was:
2629 * - "attach as much as possible" is the goal
2630 * - pad if not aligned (original size can be guessed by
2631 * original ip6 header)
2632 * Following code adds the padding if it is simple enough,
2633 * and truncates if not.
2634 */
2635 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2636 panic("assumption failed in %s:%d", __FILE__,
2637 __LINE__);
2638
2639 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2640 /* not enough room, truncate */
2641 m0->m_pkthdr.len = m0->m_len = len -
2642 sizeof(*nd_opt_rh);
2643 } else {
2644 /* enough room, pad or truncate */
2645 size_t extra;
2646
2647 extra = m0->m_pkthdr.len % 8;
2648 if (extra) {
2649 /* pad if easy enough, truncate if not */
2650 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2651 /* pad */
2652 m0->m_len += (8 - extra);
2653 m0->m_pkthdr.len += (8 - extra);
2654 } else {
2655 /* truncate */
2656 m0->m_pkthdr.len -= extra;
2657 m0->m_len -= extra;
2658 }
2659 }
2660 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2661 m0->m_pkthdr.len = m0->m_len = len -
2662 sizeof(*nd_opt_rh);
2663 }
2664
2665 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2666 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2667 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2668 nd_opt_rh->nd_opt_rh_len = len >> 3;
2669 p += sizeof(*nd_opt_rh);
2670 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2671
2672 /* connect m0 to m */
2673 m_tag_delete_chain(m0, NULL);
2674 m0->m_flags &= ~M_PKTHDR;
2675 m->m_next = m0;
2676 m->m_pkthdr.len = m->m_len + m0->m_len;
2677 m0 = NULL;
2678 }
2679 noredhdropt:;
2680 if (m0) {
2681 m_freem(m0);
2682 m0 = NULL;
2683 }
2684
2685 /* XXX: clear embedded link IDs in the inner header */
2686 in6_clearscope(&sip6->ip6_src);
2687 in6_clearscope(&sip6->ip6_dst);
2688 in6_clearscope(&nd_rd->nd_rd_target);
2689 in6_clearscope(&nd_rd->nd_rd_dst);
2690
2691 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2692
2693 nd_rd->nd_rd_cksum = 0;
2694 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2695 sizeof(*ip6), ntohs(ip6->ip6_plen));
2696
2697 if (send_sendso_input_hook != NULL) {
2698 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
2699 M_NOWAIT);
2700 if (mtag == NULL)
2701 goto fail;
2702 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
2703 m_tag_prepend(m, mtag);
2704 }
2705
2706 /* send the packet to outside... */
2707 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2708 if (outif) {
2709 icmp6_ifstat_inc(outif, ifs6_out_msg);
2710 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2711 }
2712 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2713
2714 return;
2715
2716 fail:
2717 if (m)
2718 m_freem(m);
2719 if (m0)
2720 m_freem(m0);
2721 }
2722
2723 /*
2724 * ICMPv6 socket option processing.
2725 */
2726 int
2727 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2728 {
2729 int error = 0;
2730 int optlen;
2731 struct inpcb *inp = sotoinpcb(so);
2732 int level, op, optname;
2733
2734 if (sopt) {
2735 level = sopt->sopt_level;
2736 op = sopt->sopt_dir;
2737 optname = sopt->sopt_name;
2738 optlen = sopt->sopt_valsize;
2739 } else
2740 level = op = optname = optlen = 0;
2741
2742 if (level != IPPROTO_ICMPV6) {
2743 return EINVAL;
2744 }
2745
2746 switch (op) {
2747 case PRCO_SETOPT:
2748 switch (optname) {
2749 case ICMP6_FILTER:
2750 {
2751 struct icmp6_filter ic6f;
2752
2753 if (optlen != sizeof(ic6f)) {
2754 error = EMSGSIZE;
2755 break;
2756 }
2757 error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2758 if (error == 0) {
2759 INP_WLOCK(inp);
2760 *inp->in6p_icmp6filt = ic6f;
2761 INP_WUNLOCK(inp);
2762 }
2763 break;
2764 }
2765
2766 default:
2767 error = ENOPROTOOPT;
2768 break;
2769 }
2770 break;
2771
2772 case PRCO_GETOPT:
2773 switch (optname) {
2774 case ICMP6_FILTER:
2775 {
2776 struct icmp6_filter ic6f;
2777
2778 INP_RLOCK(inp);
2779 ic6f = *inp->in6p_icmp6filt;
2780 INP_RUNLOCK(inp);
2781 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2782 break;
2783 }
2784
2785 default:
2786 error = ENOPROTOOPT;
2787 break;
2788 }
2789 break;
2790 }
2791
2792 return (error);
2793 }
2794
2795 /*
2796 * Perform rate limit check.
2797 * Returns 0 if it is okay to send the icmp6 packet.
2798 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2799 * limitation.
2800 *
2801 * XXX per-destination/type check necessary?
2802 *
2803 * dst - not used at this moment
2804 * type - not used at this moment
2805 * code - not used at this moment
2806 */
2807 static int
2808 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2809 const int code)
2810 {
2811 int ret;
2812
2813 ret = 0; /* okay to send */
2814
2815 /* PPS limit */
2816 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2817 V_icmp6errppslim)) {
2818 /* The packet is subject to rate limit */
2819 ret++;
2820 }
2821
2822 return ret;
2823 }
Cache object: 7dbe1507dd1478298564490a1e182ea3
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