FreeBSD/Linux Kernel Cross Reference
sys/netinet6/icmp6.c
1 /*-
2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $
30 */
31
32 /*-
33 * Copyright (c) 1982, 1986, 1988, 1993
34 * The Regents of the University of California. All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions
38 * are met:
39 * 1. Redistributions of source code must retain the above copyright
40 * notice, this list of conditions and the following disclaimer.
41 * 2. Redistributions in binary form must reproduce the above copyright
42 * notice, this list of conditions and the following disclaimer in the
43 * documentation and/or other materials provided with the distribution.
44 * 4. Neither the name of the University nor the names of its contributors
45 * may be used to endorse or promote products derived from this software
46 * without specific prior written permission.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 * SUCH DAMAGE.
59 *
60 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94
61 */
62
63 #include <sys/cdefs.h>
64 __FBSDID("$FreeBSD: releng/9.0/sys/netinet6/icmp6.c 227005 2011-11-01 21:21:36Z qingli $");
65
66 #include "opt_inet.h"
67 #include "opt_inet6.h"
68 #include "opt_ipsec.h"
69
70 #include <sys/param.h>
71 #include <sys/domain.h>
72 #include <sys/jail.h>
73 #include <sys/kernel.h>
74 #include <sys/lock.h>
75 #include <sys/malloc.h>
76 #include <sys/mbuf.h>
77 #include <sys/proc.h>
78 #include <sys/protosw.h>
79 #include <sys/signalvar.h>
80 #include <sys/socket.h>
81 #include <sys/socketvar.h>
82 #include <sys/sx.h>
83 #include <sys/syslog.h>
84 #include <sys/systm.h>
85 #include <sys/time.h>
86
87 #include <net/if.h>
88 #include <net/if_dl.h>
89 #include <net/if_llatbl.h>
90 #include <net/if_types.h>
91 #include <net/route.h>
92 #include <net/vnet.h>
93
94 #include <netinet/in.h>
95 #include <netinet/in_pcb.h>
96 #include <netinet/in_var.h>
97 #include <netinet/ip6.h>
98 #include <netinet/icmp6.h>
99 #include <netinet/tcp_var.h>
100
101 #include <netinet6/in6_ifattach.h>
102 #include <netinet6/in6_pcb.h>
103 #include <netinet6/ip6protosw.h>
104 #include <netinet6/ip6_var.h>
105 #include <netinet6/scope6_var.h>
106 #include <netinet6/mld6_var.h>
107 #include <netinet6/nd6.h>
108 #include <netinet6/send.h>
109
110 #ifdef IPSEC
111 #include <netipsec/ipsec.h>
112 #include <netipsec/key.h>
113 #endif
114
115 extern struct domain inet6domain;
116
117 VNET_DEFINE(struct icmp6stat, icmp6stat);
118
119 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
120 VNET_DECLARE(struct inpcbhead, ripcb);
121 VNET_DECLARE(int, icmp6errppslim);
122 static VNET_DEFINE(int, icmp6errpps_count) = 0;
123 static VNET_DEFINE(struct timeval, icmp6errppslim_last);
124 VNET_DECLARE(int, icmp6_nodeinfo);
125
126 #define V_ripcbinfo VNET(ripcbinfo)
127 #define V_ripcb VNET(ripcb)
128 #define V_icmp6errppslim VNET(icmp6errppslim)
129 #define V_icmp6errpps_count VNET(icmp6errpps_count)
130 #define V_icmp6errppslim_last VNET(icmp6errppslim_last)
131 #define V_icmp6_nodeinfo VNET(icmp6_nodeinfo)
132
133 static void icmp6_errcount(struct icmp6errstat *, int, int);
134 static int icmp6_rip6_input(struct mbuf **, int);
135 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
136 static const char *icmp6_redirect_diag __P((struct in6_addr *,
137 struct in6_addr *, struct in6_addr *));
138 static struct mbuf *ni6_input(struct mbuf *, int);
139 static struct mbuf *ni6_nametodns(const char *, int, int);
140 static int ni6_dnsmatch(const char *, int, const char *, int);
141 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *,
142 struct ifnet **, struct in6_addr *));
143 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
144 struct ifnet *, int));
145 static int icmp6_notify_error(struct mbuf **, int, int, int);
146
147 /*
148 * Kernel module interface for updating icmp6stat. The argument is an index
149 * into icmp6stat treated as an array of u_quad_t. While this encodes the
150 * general layout of icmp6stat into the caller, it doesn't encode its
151 * location, so that future changes to add, for example, per-CPU stats
152 * support won't cause binary compatibility problems for kernel modules.
153 */
154 void
155 kmod_icmp6stat_inc(int statnum)
156 {
157
158 (*((u_quad_t *)&V_icmp6stat + statnum))++;
159 }
160
161 static void
162 icmp6_errcount(struct icmp6errstat *stat, int type, int code)
163 {
164 switch (type) {
165 case ICMP6_DST_UNREACH:
166 switch (code) {
167 case ICMP6_DST_UNREACH_NOROUTE:
168 stat->icp6errs_dst_unreach_noroute++;
169 return;
170 case ICMP6_DST_UNREACH_ADMIN:
171 stat->icp6errs_dst_unreach_admin++;
172 return;
173 case ICMP6_DST_UNREACH_BEYONDSCOPE:
174 stat->icp6errs_dst_unreach_beyondscope++;
175 return;
176 case ICMP6_DST_UNREACH_ADDR:
177 stat->icp6errs_dst_unreach_addr++;
178 return;
179 case ICMP6_DST_UNREACH_NOPORT:
180 stat->icp6errs_dst_unreach_noport++;
181 return;
182 }
183 break;
184 case ICMP6_PACKET_TOO_BIG:
185 stat->icp6errs_packet_too_big++;
186 return;
187 case ICMP6_TIME_EXCEEDED:
188 switch (code) {
189 case ICMP6_TIME_EXCEED_TRANSIT:
190 stat->icp6errs_time_exceed_transit++;
191 return;
192 case ICMP6_TIME_EXCEED_REASSEMBLY:
193 stat->icp6errs_time_exceed_reassembly++;
194 return;
195 }
196 break;
197 case ICMP6_PARAM_PROB:
198 switch (code) {
199 case ICMP6_PARAMPROB_HEADER:
200 stat->icp6errs_paramprob_header++;
201 return;
202 case ICMP6_PARAMPROB_NEXTHEADER:
203 stat->icp6errs_paramprob_nextheader++;
204 return;
205 case ICMP6_PARAMPROB_OPTION:
206 stat->icp6errs_paramprob_option++;
207 return;
208 }
209 break;
210 case ND_REDIRECT:
211 stat->icp6errs_redirect++;
212 return;
213 }
214 stat->icp6errs_unknown++;
215 }
216
217 /*
218 * A wrapper function for icmp6_error() necessary when the erroneous packet
219 * may not contain enough scope zone information.
220 */
221 void
222 icmp6_error2(struct mbuf *m, int type, int code, int param,
223 struct ifnet *ifp)
224 {
225 struct ip6_hdr *ip6;
226
227 if (ifp == NULL)
228 return;
229
230 #ifndef PULLDOWN_TEST
231 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
232 #else
233 if (m->m_len < sizeof(struct ip6_hdr)) {
234 m = m_pullup(m, sizeof(struct ip6_hdr));
235 if (m == NULL)
236 return;
237 }
238 #endif
239
240 ip6 = mtod(m, struct ip6_hdr *);
241
242 if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
243 return;
244 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
245 return;
246
247 icmp6_error(m, type, code, param);
248 }
249
250 /*
251 * Generate an error packet of type error in response to bad IP6 packet.
252 */
253 void
254 icmp6_error(struct mbuf *m, int type, int code, int param)
255 {
256 struct ip6_hdr *oip6, *nip6;
257 struct icmp6_hdr *icmp6;
258 u_int preplen;
259 int off;
260 int nxt;
261
262 ICMP6STAT_INC(icp6s_error);
263
264 /* count per-type-code statistics */
265 icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, type, code);
266
267 #ifdef M_DECRYPTED /*not openbsd*/
268 if (m->m_flags & M_DECRYPTED) {
269 ICMP6STAT_INC(icp6s_canterror);
270 goto freeit;
271 }
272 #endif
273
274 #ifndef PULLDOWN_TEST
275 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
276 #else
277 if (m->m_len < sizeof(struct ip6_hdr)) {
278 m = m_pullup(m, sizeof(struct ip6_hdr));
279 if (m == NULL)
280 return;
281 }
282 #endif
283 oip6 = mtod(m, struct ip6_hdr *);
284
285 /*
286 * If the destination address of the erroneous packet is a multicast
287 * address, or the packet was sent using link-layer multicast,
288 * we should basically suppress sending an error (RFC 2463, Section
289 * 2.4).
290 * We have two exceptions (the item e.2 in that section):
291 * - the Packet Too Big message can be sent for path MTU discovery.
292 * - the Parameter Problem Message that can be allowed an icmp6 error
293 * in the option type field. This check has been done in
294 * ip6_unknown_opt(), so we can just check the type and code.
295 */
296 if ((m->m_flags & (M_BCAST|M_MCAST) ||
297 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
298 (type != ICMP6_PACKET_TOO_BIG &&
299 (type != ICMP6_PARAM_PROB ||
300 code != ICMP6_PARAMPROB_OPTION)))
301 goto freeit;
302
303 /*
304 * RFC 2463, 2.4 (e.5): source address check.
305 * XXX: the case of anycast source?
306 */
307 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
308 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
309 goto freeit;
310
311 /*
312 * If we are about to send ICMPv6 against ICMPv6 error/redirect,
313 * don't do it.
314 */
315 nxt = -1;
316 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
317 if (off >= 0 && nxt == IPPROTO_ICMPV6) {
318 struct icmp6_hdr *icp;
319
320 #ifndef PULLDOWN_TEST
321 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
322 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
323 #else
324 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
325 sizeof(*icp));
326 if (icp == NULL) {
327 ICMP6STAT_INC(icp6s_tooshort);
328 return;
329 }
330 #endif
331 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
332 icp->icmp6_type == ND_REDIRECT) {
333 /*
334 * ICMPv6 error
335 * Special case: for redirect (which is
336 * informational) we must not send icmp6 error.
337 */
338 ICMP6STAT_INC(icp6s_canterror);
339 goto freeit;
340 } else {
341 /* ICMPv6 informational - send the error */
342 }
343 } else {
344 /* non-ICMPv6 - send the error */
345 }
346
347 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
348
349 /* Finally, do rate limitation check. */
350 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
351 ICMP6STAT_INC(icp6s_toofreq);
352 goto freeit;
353 }
354
355 /*
356 * OK, ICMP6 can be generated.
357 */
358
359 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
360 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
361
362 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
363 M_PREPEND(m, preplen, M_DONTWAIT);
364 if (m && m->m_len < preplen)
365 m = m_pullup(m, preplen);
366 if (m == NULL) {
367 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
368 return;
369 }
370
371 nip6 = mtod(m, struct ip6_hdr *);
372 nip6->ip6_src = oip6->ip6_src;
373 nip6->ip6_dst = oip6->ip6_dst;
374
375 in6_clearscope(&oip6->ip6_src);
376 in6_clearscope(&oip6->ip6_dst);
377
378 icmp6 = (struct icmp6_hdr *)(nip6 + 1);
379 icmp6->icmp6_type = type;
380 icmp6->icmp6_code = code;
381 icmp6->icmp6_pptr = htonl((u_int32_t)param);
382
383 /*
384 * icmp6_reflect() is designed to be in the input path.
385 * icmp6_error() can be called from both input and output path,
386 * and if we are in output path rcvif could contain bogus value.
387 * clear m->m_pkthdr.rcvif for safety, we should have enough scope
388 * information in ip header (nip6).
389 */
390 m->m_pkthdr.rcvif = NULL;
391
392 ICMP6STAT_INC(icp6s_outhist[type]);
393 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
394
395 return;
396
397 freeit:
398 /*
399 * If we can't tell whether or not we can generate ICMP6, free it.
400 */
401 m_freem(m);
402 }
403
404 /*
405 * Process a received ICMP6 message.
406 */
407 int
408 icmp6_input(struct mbuf **mp, int *offp, int proto)
409 {
410 struct mbuf *m = *mp, *n;
411 struct ifnet *ifp;
412 struct ip6_hdr *ip6, *nip6;
413 struct icmp6_hdr *icmp6, *nicmp6;
414 int off = *offp;
415 int icmp6len = m->m_pkthdr.len - *offp;
416 int code, sum, noff;
417 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
418 int ip6len, error;
419
420 ifp = m->m_pkthdr.rcvif;
421
422 #ifndef PULLDOWN_TEST
423 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
424 /* m might change if M_LOOP. So, call mtod after this */
425 #endif
426
427 /*
428 * Locate icmp6 structure in mbuf, and check
429 * that not corrupted and of at least minimum length
430 */
431
432 ip6 = mtod(m, struct ip6_hdr *);
433 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
434 if (icmp6len < sizeof(struct icmp6_hdr)) {
435 ICMP6STAT_INC(icp6s_tooshort);
436 goto freeit;
437 }
438
439 /*
440 * Check multicast group membership.
441 * Note: SSM filters are not applied for ICMPv6 traffic.
442 */
443 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
444 struct in6_multi *inm;
445
446 inm = in6m_lookup(ifp, &ip6->ip6_dst);
447 if (inm == NULL) {
448 IP6STAT_INC(ip6s_notmember);
449 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
450 goto freeit;
451 }
452 }
453
454 /*
455 * calculate the checksum
456 */
457 #ifndef PULLDOWN_TEST
458 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
459 #else
460 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
461 if (icmp6 == NULL) {
462 ICMP6STAT_INC(icp6s_tooshort);
463 return IPPROTO_DONE;
464 }
465 #endif
466 code = icmp6->icmp6_code;
467
468 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
469 nd6log((LOG_ERR,
470 "ICMP6 checksum error(%d|%x) %s\n",
471 icmp6->icmp6_type, sum,
472 ip6_sprintf(ip6bufs, &ip6->ip6_src)));
473 ICMP6STAT_INC(icp6s_checksum);
474 goto freeit;
475 }
476
477 if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
478 /*
479 * Deliver very specific ICMP6 type only.
480 * This is important to deliver TOOBIG. Otherwise PMTUD
481 * will not work.
482 */
483 switch (icmp6->icmp6_type) {
484 case ICMP6_DST_UNREACH:
485 case ICMP6_PACKET_TOO_BIG:
486 case ICMP6_TIME_EXCEEDED:
487 break;
488 default:
489 goto freeit;
490 }
491 }
492
493 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
494 icmp6_ifstat_inc(ifp, ifs6_in_msg);
495 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
496 icmp6_ifstat_inc(ifp, ifs6_in_error);
497
498 switch (icmp6->icmp6_type) {
499 case ICMP6_DST_UNREACH:
500 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
501 switch (code) {
502 case ICMP6_DST_UNREACH_NOROUTE:
503 code = PRC_UNREACH_NET;
504 break;
505 case ICMP6_DST_UNREACH_ADMIN:
506 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
507 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
508 break;
509 case ICMP6_DST_UNREACH_ADDR:
510 code = PRC_HOSTDEAD;
511 break;
512 case ICMP6_DST_UNREACH_BEYONDSCOPE:
513 /* I mean "source address was incorrect." */
514 code = PRC_PARAMPROB;
515 break;
516 case ICMP6_DST_UNREACH_NOPORT:
517 code = PRC_UNREACH_PORT;
518 break;
519 default:
520 goto badcode;
521 }
522 goto deliver;
523 break;
524
525 case ICMP6_PACKET_TOO_BIG:
526 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
527
528 /* validation is made in icmp6_mtudisc_update */
529
530 code = PRC_MSGSIZE;
531
532 /*
533 * Updating the path MTU will be done after examining
534 * intermediate extension headers.
535 */
536 goto deliver;
537 break;
538
539 case ICMP6_TIME_EXCEEDED:
540 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
541 switch (code) {
542 case ICMP6_TIME_EXCEED_TRANSIT:
543 code = PRC_TIMXCEED_INTRANS;
544 break;
545 case ICMP6_TIME_EXCEED_REASSEMBLY:
546 code = PRC_TIMXCEED_REASS;
547 break;
548 default:
549 goto badcode;
550 }
551 goto deliver;
552 break;
553
554 case ICMP6_PARAM_PROB:
555 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
556 switch (code) {
557 case ICMP6_PARAMPROB_NEXTHEADER:
558 code = PRC_UNREACH_PROTOCOL;
559 break;
560 case ICMP6_PARAMPROB_HEADER:
561 case ICMP6_PARAMPROB_OPTION:
562 code = PRC_PARAMPROB;
563 break;
564 default:
565 goto badcode;
566 }
567 goto deliver;
568 break;
569
570 case ICMP6_ECHO_REQUEST:
571 icmp6_ifstat_inc(ifp, ifs6_in_echo);
572 if (code != 0)
573 goto badcode;
574 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
575 /* Give up remote */
576 break;
577 }
578 if ((n->m_flags & M_EXT) != 0
579 || n->m_len < off + sizeof(struct icmp6_hdr)) {
580 struct mbuf *n0 = n;
581 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
582 int n0len;
583
584 MGETHDR(n, M_DONTWAIT, n0->m_type);
585 n0len = n0->m_pkthdr.len; /* save for use below */
586 if (n)
587 M_MOVE_PKTHDR(n, n0);
588 if (n && maxlen >= MHLEN) {
589 MCLGET(n, M_DONTWAIT);
590 if ((n->m_flags & M_EXT) == 0) {
591 m_free(n);
592 n = NULL;
593 }
594 }
595 if (n == NULL) {
596 /* Give up remote */
597 m_freem(n0);
598 break;
599 }
600 /*
601 * Copy IPv6 and ICMPv6 only.
602 */
603 nip6 = mtod(n, struct ip6_hdr *);
604 bcopy(ip6, nip6, sizeof(struct ip6_hdr));
605 nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
606 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
607 noff = sizeof(struct ip6_hdr);
608 /* new mbuf contains only ipv6+icmpv6 headers */
609 n->m_len = noff + sizeof(struct icmp6_hdr);
610 /*
611 * Adjust mbuf. ip6_plen will be adjusted in
612 * ip6_output().
613 */
614 m_adj(n0, off + sizeof(struct icmp6_hdr));
615 /* recalculate complete packet size */
616 n->m_pkthdr.len = n0len + (noff - off);
617 n->m_next = n0;
618 } else {
619 nip6 = mtod(n, struct ip6_hdr *);
620 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
621 sizeof(*nicmp6));
622 noff = off;
623 }
624 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
625 nicmp6->icmp6_code = 0;
626 if (n) {
627 ICMP6STAT_INC(icp6s_reflect);
628 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
629 icmp6_reflect(n, noff);
630 }
631 break;
632
633 case ICMP6_ECHO_REPLY:
634 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
635 if (code != 0)
636 goto badcode;
637 break;
638
639 case MLD_LISTENER_QUERY:
640 case MLD_LISTENER_REPORT:
641 case MLD_LISTENER_DONE:
642 case MLDV2_LISTENER_REPORT:
643 /*
644 * Drop MLD traffic which is not link-local, has a hop limit
645 * of greater than 1 hop, or which does not have the
646 * IPv6 HBH Router Alert option.
647 * As IPv6 HBH options are stripped in ip6_input() we must
648 * check an mbuf header flag.
649 * XXX Should we also sanity check that these messages
650 * were directed to a link-local multicast prefix?
651 */
652 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
653 goto freeit;
654 if (mld_input(m, off, icmp6len) != 0)
655 return (IPPROTO_DONE);
656 /* m stays. */
657 break;
658
659 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */
660 {
661 enum { WRU, FQDN } mode;
662
663 if (!V_icmp6_nodeinfo)
664 break;
665
666 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
667 mode = WRU;
668 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
669 mode = FQDN;
670 else
671 goto badlen;
672
673 if (mode == FQDN) {
674 #ifndef PULLDOWN_TEST
675 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
676 IPPROTO_DONE);
677 #endif
678 n = m_copy(m, 0, M_COPYALL);
679 if (n)
680 n = ni6_input(n, off);
681 /* XXX meaningless if n == NULL */
682 noff = sizeof(struct ip6_hdr);
683 } else {
684 struct prison *pr;
685 u_char *p;
686 int maxlen, maxhlen, hlen;
687
688 /*
689 * XXX: this combination of flags is pointless,
690 * but should we keep this for compatibility?
691 */
692 if ((V_icmp6_nodeinfo & 5) != 5)
693 break;
694
695 if (code != 0)
696 goto badcode;
697 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
698 if (maxlen >= MCLBYTES) {
699 /* Give up remote */
700 break;
701 }
702 MGETHDR(n, M_DONTWAIT, m->m_type);
703 if (n && maxlen > MHLEN) {
704 MCLGET(n, M_DONTWAIT);
705 if ((n->m_flags & M_EXT) == 0) {
706 m_free(n);
707 n = NULL;
708 }
709 }
710 if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) {
711 /*
712 * Previous code did a blind M_COPY_PKTHDR
713 * and said "just for rcvif". If true, then
714 * we could tolerate the dup failing (due to
715 * the deep copy of the tag chain). For now
716 * be conservative and just fail.
717 */
718 m_free(n);
719 n = NULL;
720 }
721 if (n == NULL) {
722 /* Give up remote */
723 break;
724 }
725 n->m_pkthdr.rcvif = NULL;
726 n->m_len = 0;
727 maxhlen = M_TRAILINGSPACE(n) - maxlen;
728 pr = curthread->td_ucred->cr_prison;
729 mtx_lock(&pr->pr_mtx);
730 hlen = strlen(pr->pr_hostname);
731 if (maxhlen > hlen)
732 maxhlen = hlen;
733 /*
734 * Copy IPv6 and ICMPv6 only.
735 */
736 nip6 = mtod(n, struct ip6_hdr *);
737 bcopy(ip6, nip6, sizeof(struct ip6_hdr));
738 nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
739 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
740 p = (u_char *)(nicmp6 + 1);
741 bzero(p, 4);
742 /* meaningless TTL */
743 bcopy(pr->pr_hostname, p + 4, maxhlen);
744 mtx_unlock(&pr->pr_mtx);
745 noff = sizeof(struct ip6_hdr);
746 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
747 sizeof(struct icmp6_hdr) + 4 + maxhlen;
748 nicmp6->icmp6_type = ICMP6_WRUREPLY;
749 nicmp6->icmp6_code = 0;
750 }
751 if (n) {
752 ICMP6STAT_INC(icp6s_reflect);
753 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
754 icmp6_reflect(n, noff);
755 }
756 break;
757 }
758
759 case ICMP6_WRUREPLY:
760 if (code != 0)
761 goto badcode;
762 break;
763
764 case ND_ROUTER_SOLICIT:
765 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
766 if (code != 0)
767 goto badcode;
768 if (icmp6len < sizeof(struct nd_router_solicit))
769 goto badlen;
770 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
771 /* give up local */
772
773 /* Send incoming SeND packet to user space. */
774 if (send_sendso_input_hook != NULL) {
775 IP6_EXTHDR_CHECK(m, off,
776 icmp6len, IPPROTO_DONE);
777 error = send_sendso_input_hook(m, ifp,
778 SND_IN, ip6len);
779 /* -1 == no app on SEND socket */
780 if (error == 0)
781 return (IPPROTO_DONE);
782 nd6_rs_input(m, off, icmp6len);
783 } else
784 nd6_rs_input(m, off, icmp6len);
785 m = NULL;
786 goto freeit;
787 }
788 if (send_sendso_input_hook != NULL) {
789 IP6_EXTHDR_CHECK(n, off,
790 icmp6len, IPPROTO_DONE);
791 error = send_sendso_input_hook(n, ifp,
792 SND_IN, ip6len);
793 if (error == 0)
794 goto freeit;
795 /* -1 == no app on SEND socket */
796 nd6_rs_input(n, off, icmp6len);
797 } else
798 nd6_rs_input(n, off, icmp6len);
799 /* m stays. */
800 break;
801
802 case ND_ROUTER_ADVERT:
803 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
804 if (code != 0)
805 goto badcode;
806 if (icmp6len < sizeof(struct nd_router_advert))
807 goto badlen;
808 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
809
810 /* Send incoming SeND-protected/ND packet to user space. */
811 if (send_sendso_input_hook != NULL) {
812 error = send_sendso_input_hook(m, ifp,
813 SND_IN, ip6len);
814 if (error == 0)
815 return (IPPROTO_DONE);
816 nd6_ra_input(m, off, icmp6len);
817 } else
818 nd6_ra_input(m, off, icmp6len);
819 m = NULL;
820 goto freeit;
821 }
822 if (send_sendso_input_hook != NULL) {
823 error = send_sendso_input_hook(n, ifp,
824 SND_IN, ip6len);
825 if (error == 0)
826 goto freeit;
827 nd6_ra_input(n, off, icmp6len);
828 } else
829 nd6_ra_input(n, off, icmp6len);
830 /* m stays. */
831 break;
832
833 case ND_NEIGHBOR_SOLICIT:
834 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
835 if (code != 0)
836 goto badcode;
837 if (icmp6len < sizeof(struct nd_neighbor_solicit))
838 goto badlen;
839 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
840 if (send_sendso_input_hook != NULL) {
841 error = send_sendso_input_hook(m, ifp,
842 SND_IN, ip6len);
843 if (error == 0)
844 return (IPPROTO_DONE);
845 nd6_ns_input(m, off, icmp6len);
846 } else
847 nd6_ns_input(m, off, icmp6len);
848 m = NULL;
849 goto freeit;
850 }
851 if (send_sendso_input_hook != NULL) {
852 error = send_sendso_input_hook(n, ifp,
853 SND_IN, ip6len);
854 if (error == 0)
855 goto freeit;
856 nd6_ns_input(n, off, icmp6len);
857 } else
858 nd6_ns_input(n, off, icmp6len);
859 /* m stays. */
860 break;
861
862 case ND_NEIGHBOR_ADVERT:
863 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
864 if (code != 0)
865 goto badcode;
866 if (icmp6len < sizeof(struct nd_neighbor_advert))
867 goto badlen;
868 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
869
870 /* Send incoming SeND-protected/ND packet to user space. */
871 if (send_sendso_input_hook != NULL) {
872 error = send_sendso_input_hook(m, ifp,
873 SND_IN, ip6len);
874 if (error == 0)
875 return (IPPROTO_DONE);
876 nd6_na_input(m, off, icmp6len);
877 } else
878 nd6_na_input(m, off, icmp6len);
879 m = NULL;
880 goto freeit;
881 }
882 if (send_sendso_input_hook != NULL) {
883 error = send_sendso_input_hook(n, ifp,
884 SND_IN, ip6len);
885 if (error == 0)
886 goto freeit;
887 nd6_na_input(n, off, icmp6len);
888 } else
889 nd6_na_input(n, off, icmp6len);
890 /* m stays. */
891 break;
892
893 case ND_REDIRECT:
894 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
895 if (code != 0)
896 goto badcode;
897 if (icmp6len < sizeof(struct nd_redirect))
898 goto badlen;
899 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
900 if (send_sendso_input_hook != NULL) {
901 error = send_sendso_input_hook(m, ifp,
902 SND_IN, ip6len);
903 if (error == 0)
904 return (IPPROTO_DONE);
905 icmp6_redirect_input(m, off);
906 } else
907 icmp6_redirect_input(m, off);
908 m = NULL;
909 goto freeit;
910 }
911 if (send_sendso_input_hook != NULL) {
912 error = send_sendso_input_hook(n, ifp,
913 SND_IN, ip6len);
914 if (error == 0)
915 goto freeit;
916 icmp6_redirect_input(n, off);
917 } else
918 icmp6_redirect_input(n, off);
919 /* m stays. */
920 break;
921
922 case ICMP6_ROUTER_RENUMBERING:
923 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
924 code != ICMP6_ROUTER_RENUMBERING_RESULT)
925 goto badcode;
926 if (icmp6len < sizeof(struct icmp6_router_renum))
927 goto badlen;
928 break;
929
930 default:
931 nd6log((LOG_DEBUG,
932 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
933 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
934 ip6_sprintf(ip6bufd, &ip6->ip6_dst),
935 ifp ? ifp->if_index : 0));
936 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
937 /* ICMPv6 error: MUST deliver it by spec... */
938 code = PRC_NCMDS;
939 /* deliver */
940 } else {
941 /* ICMPv6 informational: MUST not deliver */
942 break;
943 }
944 deliver:
945 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
946 /* In this case, m should've been freed. */
947 return (IPPROTO_DONE);
948 }
949 break;
950
951 badcode:
952 ICMP6STAT_INC(icp6s_badcode);
953 break;
954
955 badlen:
956 ICMP6STAT_INC(icp6s_badlen);
957 break;
958 }
959
960 /* deliver the packet to appropriate sockets */
961 icmp6_rip6_input(&m, *offp);
962
963 return IPPROTO_DONE;
964
965 freeit:
966 m_freem(m);
967 return IPPROTO_DONE;
968 }
969
970 static int
971 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
972 {
973 struct mbuf *m = *mp;
974 struct icmp6_hdr *icmp6;
975 struct ip6_hdr *eip6;
976 u_int32_t notifymtu;
977 struct sockaddr_in6 icmp6src, icmp6dst;
978
979 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
980 ICMP6STAT_INC(icp6s_tooshort);
981 goto freeit;
982 }
983 #ifndef PULLDOWN_TEST
984 IP6_EXTHDR_CHECK(m, off,
985 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
986 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
987 #else
988 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
989 sizeof(*icmp6) + sizeof(struct ip6_hdr));
990 if (icmp6 == NULL) {
991 ICMP6STAT_INC(icp6s_tooshort);
992 return (-1);
993 }
994 #endif
995 eip6 = (struct ip6_hdr *)(icmp6 + 1);
996
997 /* Detect the upper level protocol */
998 {
999 void (*ctlfunc)(int, struct sockaddr *, void *);
1000 u_int8_t nxt = eip6->ip6_nxt;
1001 int eoff = off + sizeof(struct icmp6_hdr) +
1002 sizeof(struct ip6_hdr);
1003 struct ip6ctlparam ip6cp;
1004 struct in6_addr *finaldst = NULL;
1005 int icmp6type = icmp6->icmp6_type;
1006 struct ip6_frag *fh;
1007 struct ip6_rthdr *rth;
1008 struct ip6_rthdr0 *rth0;
1009 int rthlen;
1010
1011 while (1) { /* XXX: should avoid infinite loop explicitly? */
1012 struct ip6_ext *eh;
1013
1014 switch (nxt) {
1015 case IPPROTO_HOPOPTS:
1016 case IPPROTO_DSTOPTS:
1017 case IPPROTO_AH:
1018 #ifndef PULLDOWN_TEST
1019 IP6_EXTHDR_CHECK(m, 0,
1020 eoff + sizeof(struct ip6_ext), -1);
1021 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
1022 #else
1023 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
1024 eoff, sizeof(*eh));
1025 if (eh == NULL) {
1026 ICMP6STAT_INC(icp6s_tooshort);
1027 return (-1);
1028 }
1029 #endif
1030
1031 if (nxt == IPPROTO_AH)
1032 eoff += (eh->ip6e_len + 2) << 2;
1033 else
1034 eoff += (eh->ip6e_len + 1) << 3;
1035 nxt = eh->ip6e_nxt;
1036 break;
1037 case IPPROTO_ROUTING:
1038 /*
1039 * When the erroneous packet contains a
1040 * routing header, we should examine the
1041 * header to determine the final destination.
1042 * Otherwise, we can't properly update
1043 * information that depends on the final
1044 * destination (e.g. path MTU).
1045 */
1046 #ifndef PULLDOWN_TEST
1047 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
1048 rth = (struct ip6_rthdr *)
1049 (mtod(m, caddr_t) + eoff);
1050 #else
1051 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
1052 eoff, sizeof(*rth));
1053 if (rth == NULL) {
1054 ICMP6STAT_INC(icp6s_tooshort);
1055 return (-1);
1056 }
1057 #endif
1058 rthlen = (rth->ip6r_len + 1) << 3;
1059 /*
1060 * XXX: currently there is no
1061 * officially defined type other
1062 * than type-0.
1063 * Note that if the segment left field
1064 * is 0, all intermediate hops must
1065 * have been passed.
1066 */
1067 if (rth->ip6r_segleft &&
1068 rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
1069 int hops;
1070
1071 #ifndef PULLDOWN_TEST
1072 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
1073 rth0 = (struct ip6_rthdr0 *)
1074 (mtod(m, caddr_t) + eoff);
1075 #else
1076 IP6_EXTHDR_GET(rth0,
1077 struct ip6_rthdr0 *, m,
1078 eoff, rthlen);
1079 if (rth0 == NULL) {
1080 ICMP6STAT_INC(icp6s_tooshort);
1081 return (-1);
1082 }
1083 #endif
1084 /* just ignore a bogus header */
1085 if ((rth0->ip6r0_len % 2) == 0 &&
1086 (hops = rth0->ip6r0_len/2))
1087 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
1088 }
1089 eoff += rthlen;
1090 nxt = rth->ip6r_nxt;
1091 break;
1092 case IPPROTO_FRAGMENT:
1093 #ifndef PULLDOWN_TEST
1094 IP6_EXTHDR_CHECK(m, 0, eoff +
1095 sizeof(struct ip6_frag), -1);
1096 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1097 eoff);
1098 #else
1099 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1100 eoff, sizeof(*fh));
1101 if (fh == NULL) {
1102 ICMP6STAT_INC(icp6s_tooshort);
1103 return (-1);
1104 }
1105 #endif
1106 /*
1107 * Data after a fragment header is meaningless
1108 * unless it is the first fragment, but
1109 * we'll go to the notify label for path MTU
1110 * discovery.
1111 */
1112 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1113 goto notify;
1114
1115 eoff += sizeof(struct ip6_frag);
1116 nxt = fh->ip6f_nxt;
1117 break;
1118 default:
1119 /*
1120 * This case includes ESP and the No Next
1121 * Header. In such cases going to the notify
1122 * label does not have any meaning
1123 * (i.e. ctlfunc will be NULL), but we go
1124 * anyway since we might have to update
1125 * path MTU information.
1126 */
1127 goto notify;
1128 }
1129 }
1130 notify:
1131 #ifndef PULLDOWN_TEST
1132 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1133 #else
1134 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1135 sizeof(*icmp6) + sizeof(struct ip6_hdr));
1136 if (icmp6 == NULL) {
1137 ICMP6STAT_INC(icp6s_tooshort);
1138 return (-1);
1139 }
1140 #endif
1141
1142 /*
1143 * retrieve parameters from the inner IPv6 header, and convert
1144 * them into sockaddr structures.
1145 * XXX: there is no guarantee that the source or destination
1146 * addresses of the inner packet are in the same scope as
1147 * the addresses of the icmp packet. But there is no other
1148 * way to determine the zone.
1149 */
1150 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1151
1152 bzero(&icmp6dst, sizeof(icmp6dst));
1153 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1154 icmp6dst.sin6_family = AF_INET6;
1155 if (finaldst == NULL)
1156 icmp6dst.sin6_addr = eip6->ip6_dst;
1157 else
1158 icmp6dst.sin6_addr = *finaldst;
1159 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1160 goto freeit;
1161 bzero(&icmp6src, sizeof(icmp6src));
1162 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1163 icmp6src.sin6_family = AF_INET6;
1164 icmp6src.sin6_addr = eip6->ip6_src;
1165 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1166 goto freeit;
1167 icmp6src.sin6_flowinfo =
1168 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1169
1170 if (finaldst == NULL)
1171 finaldst = &eip6->ip6_dst;
1172 ip6cp.ip6c_m = m;
1173 ip6cp.ip6c_icmp6 = icmp6;
1174 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1175 ip6cp.ip6c_off = eoff;
1176 ip6cp.ip6c_finaldst = finaldst;
1177 ip6cp.ip6c_src = &icmp6src;
1178 ip6cp.ip6c_nxt = nxt;
1179
1180 m_addr_changed(m);
1181
1182 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1183 notifymtu = ntohl(icmp6->icmp6_mtu);
1184 ip6cp.ip6c_cmdarg = (void *)¬ifymtu;
1185 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/
1186 }
1187
1188 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1189 (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1190 if (ctlfunc) {
1191 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1192 &ip6cp);
1193 }
1194 }
1195 *mp = m;
1196 return (0);
1197
1198 freeit:
1199 m_freem(m);
1200 return (-1);
1201 }
1202
1203 void
1204 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1205 {
1206 struct in6_addr *dst = ip6cp->ip6c_finaldst;
1207 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1208 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1209 u_int mtu = ntohl(icmp6->icmp6_mtu);
1210 struct in_conninfo inc;
1211
1212 #if 0
1213 /*
1214 * RFC2460 section 5, last paragraph.
1215 * even though minimum link MTU for IPv6 is IPV6_MMTU,
1216 * we may see ICMPv6 too big with mtu < IPV6_MMTU
1217 * due to packet translator in the middle.
1218 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1219 * special handling.
1220 */
1221 if (mtu < IPV6_MMTU)
1222 return;
1223 #endif
1224
1225 /*
1226 * we reject ICMPv6 too big with abnormally small value.
1227 * XXX what is the good definition of "abnormally small"?
1228 */
1229 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1230 return;
1231
1232 if (!validated)
1233 return;
1234
1235 /*
1236 * In case the suggested mtu is less than IPV6_MMTU, we
1237 * only need to remember that it was for above mentioned
1238 * "alwaysfrag" case.
1239 * Try to be as close to the spec as possible.
1240 */
1241 if (mtu < IPV6_MMTU)
1242 mtu = IPV6_MMTU - 8;
1243
1244 bzero(&inc, sizeof(inc));
1245 inc.inc_flags |= INC_ISIPV6;
1246 inc.inc6_faddr = *dst;
1247 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1248 return;
1249
1250 if (mtu < tcp_maxmtu6(&inc, NULL)) {
1251 tcp_hc_updatemtu(&inc, mtu);
1252 ICMP6STAT_INC(icp6s_pmtuchg);
1253 }
1254 }
1255
1256 /*
1257 * Process a Node Information Query packet, based on
1258 * draft-ietf-ipngwg-icmp-name-lookups-07.
1259 *
1260 * Spec incompatibilities:
1261 * - IPv6 Subject address handling
1262 * - IPv4 Subject address handling support missing
1263 * - Proxy reply (answer even if it's not for me)
1264 * - joins NI group address at in6_ifattach() time only, does not cope
1265 * with hostname changes by sethostname(3)
1266 */
1267 static struct mbuf *
1268 ni6_input(struct mbuf *m, int off)
1269 {
1270 struct icmp6_nodeinfo *ni6, *nni6;
1271 struct mbuf *n = NULL;
1272 struct prison *pr;
1273 u_int16_t qtype;
1274 int subjlen;
1275 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1276 struct ni_reply_fqdn *fqdn;
1277 int addrs; /* for NI_QTYPE_NODEADDR */
1278 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1279 struct in6_addr in6_subj; /* subject address */
1280 struct ip6_hdr *ip6;
1281 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */
1282 char *subj = NULL;
1283 struct in6_ifaddr *ia6 = NULL;
1284
1285 ip6 = mtod(m, struct ip6_hdr *);
1286 #ifndef PULLDOWN_TEST
1287 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1288 #else
1289 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1290 if (ni6 == NULL) {
1291 /* m is already reclaimed */
1292 return (NULL);
1293 }
1294 #endif
1295
1296 /*
1297 * Validate IPv6 source address.
1298 * The default configuration MUST be to refuse answering queries from
1299 * global-scope addresses according to RFC4602.
1300 * Notes:
1301 * - it's not very clear what "refuse" means; this implementation
1302 * simply drops it.
1303 * - it's not very easy to identify global-scope (unicast) addresses
1304 * since there are many prefixes for them. It should be safer
1305 * and in practice sufficient to check "all" but loopback and
1306 * link-local (note that site-local unicast was deprecated and
1307 * ULA is defined as global scope-wise)
1308 */
1309 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1310 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1311 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1312 goto bad;
1313
1314 /*
1315 * Validate IPv6 destination address.
1316 *
1317 * The Responder must discard the Query without further processing
1318 * unless it is one of the Responder's unicast or anycast addresses, or
1319 * a link-local scope multicast address which the Responder has joined.
1320 * [RFC4602, Section 5.]
1321 */
1322 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1323 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1324 goto bad;
1325 /* else it's a link-local multicast, fine */
1326 } else { /* unicast or anycast */
1327 if ((ia6 = ip6_getdstifaddr(m)) == NULL)
1328 goto bad; /* XXX impossible */
1329
1330 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1331 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1332 ifa_free(&ia6->ia_ifa);
1333 nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1334 "a temporary address in %s:%d",
1335 __FILE__, __LINE__));
1336 goto bad;
1337 }
1338 ifa_free(&ia6->ia_ifa);
1339 }
1340
1341 /* validate query Subject field. */
1342 qtype = ntohs(ni6->ni_qtype);
1343 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1344 switch (qtype) {
1345 case NI_QTYPE_NOOP:
1346 case NI_QTYPE_SUPTYPES:
1347 /* 07 draft */
1348 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1349 break;
1350 /* FALLTHROUGH */
1351 case NI_QTYPE_FQDN:
1352 case NI_QTYPE_NODEADDR:
1353 case NI_QTYPE_IPV4ADDR:
1354 switch (ni6->ni_code) {
1355 case ICMP6_NI_SUBJ_IPV6:
1356 #if ICMP6_NI_SUBJ_IPV6 != 0
1357 case 0:
1358 #endif
1359 /*
1360 * backward compatibility - try to accept 03 draft
1361 * format, where no Subject is present.
1362 */
1363 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1364 subjlen == 0) {
1365 oldfqdn++;
1366 break;
1367 }
1368 #if ICMP6_NI_SUBJ_IPV6 != 0
1369 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1370 goto bad;
1371 #endif
1372
1373 if (subjlen != sizeof(struct in6_addr))
1374 goto bad;
1375
1376 /*
1377 * Validate Subject address.
1378 *
1379 * Not sure what exactly "address belongs to the node"
1380 * means in the spec, is it just unicast, or what?
1381 *
1382 * At this moment we consider Subject address as
1383 * "belong to the node" if the Subject address equals
1384 * to the IPv6 destination address; validation for
1385 * IPv6 destination address should have done enough
1386 * check for us.
1387 *
1388 * We do not do proxy at this moment.
1389 */
1390 /* m_pulldown instead of copy? */
1391 m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1392 subjlen, (caddr_t)&in6_subj);
1393 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1394 goto bad;
1395
1396 subj = (char *)&in6_subj;
1397 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1398 break;
1399
1400 /*
1401 * XXX if we are to allow other cases, we should really
1402 * be careful about scope here.
1403 * basically, we should disallow queries toward IPv6
1404 * destination X with subject Y,
1405 * if scope(X) > scope(Y).
1406 * if we allow scope(X) > scope(Y), it will result in
1407 * information leakage across scope boundary.
1408 */
1409 goto bad;
1410
1411 case ICMP6_NI_SUBJ_FQDN:
1412 /*
1413 * Validate Subject name with gethostname(3).
1414 *
1415 * The behavior may need some debate, since:
1416 * - we are not sure if the node has FQDN as
1417 * hostname (returned by gethostname(3)).
1418 * - the code does wildcard match for truncated names.
1419 * however, we are not sure if we want to perform
1420 * wildcard match, if gethostname(3) side has
1421 * truncated hostname.
1422 */
1423 pr = curthread->td_ucred->cr_prison;
1424 mtx_lock(&pr->pr_mtx);
1425 n = ni6_nametodns(pr->pr_hostname,
1426 strlen(pr->pr_hostname), 0);
1427 mtx_unlock(&pr->pr_mtx);
1428 if (!n || n->m_next || n->m_len == 0)
1429 goto bad;
1430 IP6_EXTHDR_GET(subj, char *, m,
1431 off + sizeof(struct icmp6_nodeinfo), subjlen);
1432 if (subj == NULL)
1433 goto bad;
1434 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1435 n->m_len)) {
1436 goto bad;
1437 }
1438 m_freem(n);
1439 n = NULL;
1440 break;
1441
1442 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */
1443 default:
1444 goto bad;
1445 }
1446 break;
1447 }
1448
1449 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */
1450 switch (qtype) {
1451 case NI_QTYPE_FQDN:
1452 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1453 goto bad;
1454 break;
1455 case NI_QTYPE_NODEADDR:
1456 case NI_QTYPE_IPV4ADDR:
1457 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1458 goto bad;
1459 break;
1460 }
1461
1462 /* guess reply length */
1463 switch (qtype) {
1464 case NI_QTYPE_NOOP:
1465 break; /* no reply data */
1466 case NI_QTYPE_SUPTYPES:
1467 replylen += sizeof(u_int32_t);
1468 break;
1469 case NI_QTYPE_FQDN:
1470 /* XXX will append an mbuf */
1471 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1472 break;
1473 case NI_QTYPE_NODEADDR:
1474 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1475 if ((replylen += addrs * (sizeof(struct in6_addr) +
1476 sizeof(u_int32_t))) > MCLBYTES)
1477 replylen = MCLBYTES; /* XXX: will truncate pkt later */
1478 break;
1479 case NI_QTYPE_IPV4ADDR:
1480 /* unsupported - should respond with unknown Qtype? */
1481 break;
1482 default:
1483 /*
1484 * XXX: We must return a reply with the ICMP6 code
1485 * `unknown Qtype' in this case. However we regard the case
1486 * as an FQDN query for backward compatibility.
1487 * Older versions set a random value to this field,
1488 * so it rarely varies in the defined qtypes.
1489 * But the mechanism is not reliable...
1490 * maybe we should obsolete older versions.
1491 */
1492 qtype = NI_QTYPE_FQDN;
1493 /* XXX will append an mbuf */
1494 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1495 oldfqdn++;
1496 break;
1497 }
1498
1499 /* allocate an mbuf to reply. */
1500 MGETHDR(n, M_DONTWAIT, m->m_type);
1501 if (n == NULL) {
1502 m_freem(m);
1503 return (NULL);
1504 }
1505 M_MOVE_PKTHDR(n, m); /* just for recvif */
1506 if (replylen > MHLEN) {
1507 if (replylen > MCLBYTES) {
1508 /*
1509 * XXX: should we try to allocate more? But MCLBYTES
1510 * is probably much larger than IPV6_MMTU...
1511 */
1512 goto bad;
1513 }
1514 MCLGET(n, M_DONTWAIT);
1515 if ((n->m_flags & M_EXT) == 0) {
1516 goto bad;
1517 }
1518 }
1519 n->m_pkthdr.len = n->m_len = replylen;
1520
1521 /* copy mbuf header and IPv6 + Node Information base headers */
1522 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1523 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1524 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1525
1526 /* qtype dependent procedure */
1527 switch (qtype) {
1528 case NI_QTYPE_NOOP:
1529 nni6->ni_code = ICMP6_NI_SUCCESS;
1530 nni6->ni_flags = 0;
1531 break;
1532 case NI_QTYPE_SUPTYPES:
1533 {
1534 u_int32_t v;
1535 nni6->ni_code = ICMP6_NI_SUCCESS;
1536 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1537 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1538 v = (u_int32_t)htonl(0x0000000f);
1539 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1540 break;
1541 }
1542 case NI_QTYPE_FQDN:
1543 nni6->ni_code = ICMP6_NI_SUCCESS;
1544 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1545 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1546 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1547 fqdn->ni_fqdn_ttl = 0; /* ditto. */
1548 /*
1549 * XXX do we really have FQDN in hostname?
1550 */
1551 pr = curthread->td_ucred->cr_prison;
1552 mtx_lock(&pr->pr_mtx);
1553 n->m_next = ni6_nametodns(pr->pr_hostname,
1554 strlen(pr->pr_hostname), oldfqdn);
1555 mtx_unlock(&pr->pr_mtx);
1556 if (n->m_next == NULL)
1557 goto bad;
1558 /* XXX we assume that n->m_next is not a chain */
1559 if (n->m_next->m_next != NULL)
1560 goto bad;
1561 n->m_pkthdr.len += n->m_next->m_len;
1562 break;
1563 case NI_QTYPE_NODEADDR:
1564 {
1565 int lenlim, copied;
1566
1567 nni6->ni_code = ICMP6_NI_SUCCESS;
1568 n->m_pkthdr.len = n->m_len =
1569 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1570 lenlim = M_TRAILINGSPACE(n);
1571 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1572 /* XXX: reset mbuf length */
1573 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1574 sizeof(struct icmp6_nodeinfo) + copied;
1575 break;
1576 }
1577 default:
1578 break; /* XXX impossible! */
1579 }
1580
1581 nni6->ni_type = ICMP6_NI_REPLY;
1582 m_freem(m);
1583 return (n);
1584
1585 bad:
1586 m_freem(m);
1587 if (n)
1588 m_freem(n);
1589 return (NULL);
1590 }
1591
1592 /*
1593 * make a mbuf with DNS-encoded string. no compression support.
1594 *
1595 * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1596 * treated as truncated name (two \0 at the end). this is a wild guess.
1597 *
1598 * old - return pascal string if non-zero
1599 */
1600 static struct mbuf *
1601 ni6_nametodns(const char *name, int namelen, int old)
1602 {
1603 struct mbuf *m;
1604 char *cp, *ep;
1605 const char *p, *q;
1606 int i, len, nterm;
1607
1608 if (old)
1609 len = namelen + 1;
1610 else
1611 len = MCLBYTES;
1612
1613 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1614 MGET(m, M_DONTWAIT, MT_DATA);
1615 if (m && len > MLEN) {
1616 MCLGET(m, M_DONTWAIT);
1617 if ((m->m_flags & M_EXT) == 0)
1618 goto fail;
1619 }
1620 if (!m)
1621 goto fail;
1622 m->m_next = NULL;
1623
1624 if (old) {
1625 m->m_len = len;
1626 *mtod(m, char *) = namelen;
1627 bcopy(name, mtod(m, char *) + 1, namelen);
1628 return m;
1629 } else {
1630 m->m_len = 0;
1631 cp = mtod(m, char *);
1632 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1633
1634 /* if not certain about my name, return empty buffer */
1635 if (namelen == 0)
1636 return m;
1637
1638 /*
1639 * guess if it looks like shortened hostname, or FQDN.
1640 * shortened hostname needs two trailing "\0".
1641 */
1642 i = 0;
1643 for (p = name; p < name + namelen; p++) {
1644 if (*p && *p == '.')
1645 i++;
1646 }
1647 if (i < 2)
1648 nterm = 2;
1649 else
1650 nterm = 1;
1651
1652 p = name;
1653 while (cp < ep && p < name + namelen) {
1654 i = 0;
1655 for (q = p; q < name + namelen && *q && *q != '.'; q++)
1656 i++;
1657 /* result does not fit into mbuf */
1658 if (cp + i + 1 >= ep)
1659 goto fail;
1660 /*
1661 * DNS label length restriction, RFC1035 page 8.
1662 * "i == 0" case is included here to avoid returning
1663 * 0-length label on "foo..bar".
1664 */
1665 if (i <= 0 || i >= 64)
1666 goto fail;
1667 *cp++ = i;
1668 bcopy(p, cp, i);
1669 cp += i;
1670 p = q;
1671 if (p < name + namelen && *p == '.')
1672 p++;
1673 }
1674 /* termination */
1675 if (cp + nterm >= ep)
1676 goto fail;
1677 while (nterm-- > 0)
1678 *cp++ = '\0';
1679 m->m_len = cp - mtod(m, char *);
1680 return m;
1681 }
1682
1683 panic("should not reach here");
1684 /* NOTREACHED */
1685
1686 fail:
1687 if (m)
1688 m_freem(m);
1689 return NULL;
1690 }
1691
1692 /*
1693 * check if two DNS-encoded string matches. takes care of truncated
1694 * form (with \0\0 at the end). no compression support.
1695 * XXX upper/lowercase match (see RFC2065)
1696 */
1697 static int
1698 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1699 {
1700 const char *a0, *b0;
1701 int l;
1702
1703 /* simplest case - need validation? */
1704 if (alen == blen && bcmp(a, b, alen) == 0)
1705 return 1;
1706
1707 a0 = a;
1708 b0 = b;
1709
1710 /* termination is mandatory */
1711 if (alen < 2 || blen < 2)
1712 return 0;
1713 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1714 return 0;
1715 alen--;
1716 blen--;
1717
1718 while (a - a0 < alen && b - b0 < blen) {
1719 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1720 return 0;
1721
1722 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1723 return 0;
1724 /* we don't support compression yet */
1725 if (a[0] >= 64 || b[0] >= 64)
1726 return 0;
1727
1728 /* truncated case */
1729 if (a[0] == 0 && a - a0 == alen - 1)
1730 return 1;
1731 if (b[0] == 0 && b - b0 == blen - 1)
1732 return 1;
1733 if (a[0] == 0 || b[0] == 0)
1734 return 0;
1735
1736 if (a[0] != b[0])
1737 return 0;
1738 l = a[0];
1739 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1740 return 0;
1741 if (bcmp(a + 1, b + 1, l) != 0)
1742 return 0;
1743
1744 a += 1 + l;
1745 b += 1 + l;
1746 }
1747
1748 if (a - a0 == alen && b - b0 == blen)
1749 return 1;
1750 else
1751 return 0;
1752 }
1753
1754 /*
1755 * calculate the number of addresses to be returned in the node info reply.
1756 */
1757 static int
1758 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1759 struct in6_addr *subj)
1760 {
1761 struct ifnet *ifp;
1762 struct in6_ifaddr *ifa6;
1763 struct ifaddr *ifa;
1764 int addrs = 0, addrsofif, iffound = 0;
1765 int niflags = ni6->ni_flags;
1766
1767 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1768 switch (ni6->ni_code) {
1769 case ICMP6_NI_SUBJ_IPV6:
1770 if (subj == NULL) /* must be impossible... */
1771 return (0);
1772 break;
1773 default:
1774 /*
1775 * XXX: we only support IPv6 subject address for
1776 * this Qtype.
1777 */
1778 return (0);
1779 }
1780 }
1781
1782 IFNET_RLOCK_NOSLEEP();
1783 for (ifp = TAILQ_FIRST(&V_ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1784 addrsofif = 0;
1785 IF_ADDR_LOCK(ifp);
1786 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1787 if (ifa->ifa_addr->sa_family != AF_INET6)
1788 continue;
1789 ifa6 = (struct in6_ifaddr *)ifa;
1790
1791 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1792 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1793 iffound = 1;
1794
1795 /*
1796 * IPv4-mapped addresses can only be returned by a
1797 * Node Information proxy, since they represent
1798 * addresses of IPv4-only nodes, which perforce do
1799 * not implement this protocol.
1800 * [icmp-name-lookups-07, Section 5.4]
1801 * So we don't support NI_NODEADDR_FLAG_COMPAT in
1802 * this function at this moment.
1803 */
1804
1805 /* What do we have to do about ::1? */
1806 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1807 case IPV6_ADDR_SCOPE_LINKLOCAL:
1808 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1809 continue;
1810 break;
1811 case IPV6_ADDR_SCOPE_SITELOCAL:
1812 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1813 continue;
1814 break;
1815 case IPV6_ADDR_SCOPE_GLOBAL:
1816 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1817 continue;
1818 break;
1819 default:
1820 continue;
1821 }
1822
1823 /*
1824 * check if anycast is okay.
1825 * XXX: just experimental. not in the spec.
1826 */
1827 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1828 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1829 continue; /* we need only unicast addresses */
1830 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1831 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1832 continue;
1833 }
1834 addrsofif++; /* count the address */
1835 }
1836 IF_ADDR_UNLOCK(ifp);
1837 if (iffound) {
1838 *ifpp = ifp;
1839 IFNET_RUNLOCK_NOSLEEP();
1840 return (addrsofif);
1841 }
1842
1843 addrs += addrsofif;
1844 }
1845 IFNET_RUNLOCK_NOSLEEP();
1846
1847 return (addrs);
1848 }
1849
1850 static int
1851 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1852 struct ifnet *ifp0, int resid)
1853 {
1854 struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
1855 struct in6_ifaddr *ifa6;
1856 struct ifaddr *ifa;
1857 struct ifnet *ifp_dep = NULL;
1858 int copied = 0, allow_deprecated = 0;
1859 u_char *cp = (u_char *)(nni6 + 1);
1860 int niflags = ni6->ni_flags;
1861 u_int32_t ltime;
1862
1863 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1864 return (0); /* needless to copy */
1865
1866 IFNET_RLOCK_NOSLEEP();
1867 again:
1868
1869 for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1870 IF_ADDR_LOCK(ifp);
1871 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1872 if (ifa->ifa_addr->sa_family != AF_INET6)
1873 continue;
1874 ifa6 = (struct in6_ifaddr *)ifa;
1875
1876 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1877 allow_deprecated == 0) {
1878 /*
1879 * prefererred address should be put before
1880 * deprecated addresses.
1881 */
1882
1883 /* record the interface for later search */
1884 if (ifp_dep == NULL)
1885 ifp_dep = ifp;
1886
1887 continue;
1888 } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1889 allow_deprecated != 0)
1890 continue; /* we now collect deprecated addrs */
1891
1892 /* What do we have to do about ::1? */
1893 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1894 case IPV6_ADDR_SCOPE_LINKLOCAL:
1895 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1896 continue;
1897 break;
1898 case IPV6_ADDR_SCOPE_SITELOCAL:
1899 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1900 continue;
1901 break;
1902 case IPV6_ADDR_SCOPE_GLOBAL:
1903 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1904 continue;
1905 break;
1906 default:
1907 continue;
1908 }
1909
1910 /*
1911 * check if anycast is okay.
1912 * XXX: just experimental. not in the spec.
1913 */
1914 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1915 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1916 continue;
1917 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1918 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1919 continue;
1920 }
1921
1922 /* now we can copy the address */
1923 if (resid < sizeof(struct in6_addr) +
1924 sizeof(u_int32_t)) {
1925 IF_ADDR_UNLOCK(ifp);
1926 /*
1927 * We give up much more copy.
1928 * Set the truncate flag and return.
1929 */
1930 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1931 IFNET_RUNLOCK_NOSLEEP();
1932 return (copied);
1933 }
1934
1935 /*
1936 * Set the TTL of the address.
1937 * The TTL value should be one of the following
1938 * according to the specification:
1939 *
1940 * 1. The remaining lifetime of a DHCP lease on the
1941 * address, or
1942 * 2. The remaining Valid Lifetime of a prefix from
1943 * which the address was derived through Stateless
1944 * Autoconfiguration.
1945 *
1946 * Note that we currently do not support stateful
1947 * address configuration by DHCPv6, so the former
1948 * case can't happen.
1949 */
1950 if (ifa6->ia6_lifetime.ia6t_expire == 0)
1951 ltime = ND6_INFINITE_LIFETIME;
1952 else {
1953 if (ifa6->ia6_lifetime.ia6t_expire >
1954 time_second)
1955 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1956 else
1957 ltime = 0;
1958 }
1959
1960 bcopy(<ime, cp, sizeof(u_int32_t));
1961 cp += sizeof(u_int32_t);
1962
1963 /* copy the address itself */
1964 bcopy(&ifa6->ia_addr.sin6_addr, cp,
1965 sizeof(struct in6_addr));
1966 in6_clearscope((struct in6_addr *)cp); /* XXX */
1967 cp += sizeof(struct in6_addr);
1968
1969 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1970 copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1971 }
1972 IF_ADDR_UNLOCK(ifp);
1973 if (ifp0) /* we need search only on the specified IF */
1974 break;
1975 }
1976
1977 if (allow_deprecated == 0 && ifp_dep != NULL) {
1978 ifp = ifp_dep;
1979 allow_deprecated = 1;
1980
1981 goto again;
1982 }
1983
1984 IFNET_RUNLOCK_NOSLEEP();
1985
1986 return (copied);
1987 }
1988
1989 /*
1990 * XXX almost dup'ed code with rip6_input.
1991 */
1992 static int
1993 icmp6_rip6_input(struct mbuf **mp, int off)
1994 {
1995 struct mbuf *m = *mp;
1996 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1997 struct inpcb *in6p;
1998 struct inpcb *last = NULL;
1999 struct sockaddr_in6 fromsa;
2000 struct icmp6_hdr *icmp6;
2001 struct mbuf *opts = NULL;
2002
2003 #ifndef PULLDOWN_TEST
2004 /* this is assumed to be safe. */
2005 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
2006 #else
2007 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
2008 if (icmp6 == NULL) {
2009 /* m is already reclaimed */
2010 return (IPPROTO_DONE);
2011 }
2012 #endif
2013
2014 /*
2015 * XXX: the address may have embedded scope zone ID, which should be
2016 * hidden from applications.
2017 */
2018 bzero(&fromsa, sizeof(fromsa));
2019 fromsa.sin6_family = AF_INET6;
2020 fromsa.sin6_len = sizeof(struct sockaddr_in6);
2021 fromsa.sin6_addr = ip6->ip6_src;
2022 if (sa6_recoverscope(&fromsa)) {
2023 m_freem(m);
2024 return (IPPROTO_DONE);
2025 }
2026
2027 INP_INFO_RLOCK(&V_ripcbinfo);
2028 LIST_FOREACH(in6p, &V_ripcb, inp_list) {
2029 if ((in6p->inp_vflag & INP_IPV6) == 0)
2030 continue;
2031 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
2032 continue;
2033 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
2034 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
2035 continue;
2036 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
2037 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
2038 continue;
2039 INP_RLOCK(in6p);
2040 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
2041 in6p->in6p_icmp6filt)) {
2042 INP_RUNLOCK(in6p);
2043 continue;
2044 }
2045 if (last != NULL) {
2046 struct mbuf *n = NULL;
2047
2048 /*
2049 * Recent network drivers tend to allocate a single
2050 * mbuf cluster, rather than to make a couple of
2051 * mbufs without clusters. Also, since the IPv6 code
2052 * path tries to avoid m_pullup(), it is highly
2053 * probable that we still have an mbuf cluster here
2054 * even though the necessary length can be stored in an
2055 * mbuf's internal buffer.
2056 * Meanwhile, the default size of the receive socket
2057 * buffer for raw sockets is not so large. This means
2058 * the possibility of packet loss is relatively higher
2059 * than before. To avoid this scenario, we copy the
2060 * received data to a separate mbuf that does not use
2061 * a cluster, if possible.
2062 * XXX: it is better to copy the data after stripping
2063 * intermediate headers.
2064 */
2065 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2066 m->m_len <= MHLEN) {
2067 MGET(n, M_DONTWAIT, m->m_type);
2068 if (n != NULL) {
2069 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2070 bcopy(m->m_data, n->m_data,
2071 m->m_len);
2072 n->m_len = m->m_len;
2073 } else {
2074 m_free(n);
2075 n = NULL;
2076 }
2077 }
2078 }
2079 if (n != NULL ||
2080 (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
2081 if (last->inp_flags & INP_CONTROLOPTS)
2082 ip6_savecontrol(last, n, &opts);
2083 /* strip intermediate headers */
2084 m_adj(n, off);
2085 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2086 if (sbappendaddr_locked(
2087 &last->inp_socket->so_rcv,
2088 (struct sockaddr *)&fromsa, n, opts)
2089 == 0) {
2090 /* should notify about lost packet */
2091 m_freem(n);
2092 if (opts) {
2093 m_freem(opts);
2094 }
2095 SOCKBUF_UNLOCK(
2096 &last->inp_socket->so_rcv);
2097 } else
2098 sorwakeup_locked(last->inp_socket);
2099 opts = NULL;
2100 }
2101 INP_RUNLOCK(last);
2102 }
2103 last = in6p;
2104 }
2105 INP_INFO_RUNLOCK(&V_ripcbinfo);
2106 if (last != NULL) {
2107 if (last->inp_flags & INP_CONTROLOPTS)
2108 ip6_savecontrol(last, m, &opts);
2109 /* strip intermediate headers */
2110 m_adj(m, off);
2111
2112 /* avoid using mbuf clusters if possible (see above) */
2113 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2114 m->m_len <= MHLEN) {
2115 struct mbuf *n;
2116
2117 MGET(n, M_DONTWAIT, m->m_type);
2118 if (n != NULL) {
2119 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2120 bcopy(m->m_data, n->m_data, m->m_len);
2121 n->m_len = m->m_len;
2122
2123 m_freem(m);
2124 m = n;
2125 } else {
2126 m_freem(n);
2127 n = NULL;
2128 }
2129 }
2130 }
2131 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2132 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
2133 (struct sockaddr *)&fromsa, m, opts) == 0) {
2134 m_freem(m);
2135 if (opts)
2136 m_freem(opts);
2137 SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
2138 } else
2139 sorwakeup_locked(last->inp_socket);
2140 INP_RUNLOCK(last);
2141 } else {
2142 m_freem(m);
2143 IP6STAT_DEC(ip6s_delivered);
2144 }
2145 return IPPROTO_DONE;
2146 }
2147
2148 /*
2149 * Reflect the ip6 packet back to the source.
2150 * OFF points to the icmp6 header, counted from the top of the mbuf.
2151 */
2152 void
2153 icmp6_reflect(struct mbuf *m, size_t off)
2154 {
2155 struct ip6_hdr *ip6;
2156 struct icmp6_hdr *icmp6;
2157 struct in6_ifaddr *ia = NULL;
2158 int plen;
2159 int type, code;
2160 struct ifnet *outif = NULL;
2161 struct in6_addr origdst, src, *srcp = NULL;
2162
2163 /* too short to reflect */
2164 if (off < sizeof(struct ip6_hdr)) {
2165 nd6log((LOG_DEBUG,
2166 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2167 (u_long)off, (u_long)sizeof(struct ip6_hdr),
2168 __FILE__, __LINE__));
2169 goto bad;
2170 }
2171
2172 /*
2173 * If there are extra headers between IPv6 and ICMPv6, strip
2174 * off that header first.
2175 */
2176 #ifdef DIAGNOSTIC
2177 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2178 panic("assumption failed in icmp6_reflect");
2179 #endif
2180 if (off > sizeof(struct ip6_hdr)) {
2181 size_t l;
2182 struct ip6_hdr nip6;
2183
2184 l = off - sizeof(struct ip6_hdr);
2185 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2186 m_adj(m, l);
2187 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2188 if (m->m_len < l) {
2189 if ((m = m_pullup(m, l)) == NULL)
2190 return;
2191 }
2192 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2193 } else /* off == sizeof(struct ip6_hdr) */ {
2194 size_t l;
2195 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2196 if (m->m_len < l) {
2197 if ((m = m_pullup(m, l)) == NULL)
2198 return;
2199 }
2200 }
2201 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2202 ip6 = mtod(m, struct ip6_hdr *);
2203 ip6->ip6_nxt = IPPROTO_ICMPV6;
2204 icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2205 type = icmp6->icmp6_type; /* keep type for statistics */
2206 code = icmp6->icmp6_code; /* ditto. */
2207
2208 origdst = ip6->ip6_dst;
2209 /*
2210 * ip6_input() drops a packet if its src is multicast.
2211 * So, the src is never multicast.
2212 */
2213 ip6->ip6_dst = ip6->ip6_src;
2214
2215 /*
2216 * If the incoming packet was addressed directly to us (i.e. unicast),
2217 * use dst as the src for the reply.
2218 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2219 * (for example) when we encounter an error while forwarding procedure
2220 * destined to a duplicated address of ours.
2221 * Note that ip6_getdstifaddr() may fail if we are in an error handling
2222 * procedure of an outgoing packet of our own, in which case we need
2223 * to search in the ifaddr list.
2224 */
2225 if (!IN6_IS_ADDR_MULTICAST(&origdst)) {
2226 if ((ia = ip6_getdstifaddr(m))) {
2227 if (!(ia->ia6_flags &
2228 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)))
2229 srcp = &ia->ia_addr.sin6_addr;
2230 } else {
2231 struct sockaddr_in6 d;
2232
2233 bzero(&d, sizeof(d));
2234 d.sin6_family = AF_INET6;
2235 d.sin6_len = sizeof(d);
2236 d.sin6_addr = origdst;
2237 ia = (struct in6_ifaddr *)
2238 ifa_ifwithaddr((struct sockaddr *)&d);
2239 if (ia &&
2240 !(ia->ia6_flags &
2241 (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2242 srcp = &ia->ia_addr.sin6_addr;
2243 }
2244 }
2245 }
2246
2247 if (srcp == NULL) {
2248 int e;
2249 struct sockaddr_in6 sin6;
2250 struct route_in6 ro;
2251
2252 /*
2253 * This case matches to multicasts, our anycast, or unicasts
2254 * that we do not own. Select a source address based on the
2255 * source address of the erroneous packet.
2256 */
2257 bzero(&sin6, sizeof(sin6));
2258 sin6.sin6_family = AF_INET6;
2259 sin6.sin6_len = sizeof(sin6);
2260 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
2261
2262 bzero(&ro, sizeof(ro));
2263 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src);
2264 if (ro.ro_rt)
2265 RTFREE(ro.ro_rt); /* XXX: we could use this */
2266 if (e) {
2267 char ip6buf[INET6_ADDRSTRLEN];
2268 nd6log((LOG_DEBUG,
2269 "icmp6_reflect: source can't be determined: "
2270 "dst=%s, error=%d\n",
2271 ip6_sprintf(ip6buf, &sin6.sin6_addr), e));
2272 goto bad;
2273 }
2274 srcp = &src;
2275 }
2276
2277 ip6->ip6_src = *srcp;
2278 ip6->ip6_flow = 0;
2279 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2280 ip6->ip6_vfc |= IPV6_VERSION;
2281 ip6->ip6_nxt = IPPROTO_ICMPV6;
2282 if (outif)
2283 ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
2284 else if (m->m_pkthdr.rcvif) {
2285 /* XXX: This may not be the outgoing interface */
2286 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2287 } else
2288 ip6->ip6_hlim = V_ip6_defhlim;
2289
2290 icmp6->icmp6_cksum = 0;
2291 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2292 sizeof(struct ip6_hdr), plen);
2293
2294 /*
2295 * XXX option handling
2296 */
2297
2298 m->m_flags &= ~(M_BCAST|M_MCAST);
2299
2300 m_addr_changed(m);
2301
2302 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2303 if (outif)
2304 icmp6_ifoutstat_inc(outif, type, code);
2305
2306 if (ia != NULL)
2307 ifa_free(&ia->ia_ifa);
2308 return;
2309
2310 bad:
2311 if (ia != NULL)
2312 ifa_free(&ia->ia_ifa);
2313 m_freem(m);
2314 return;
2315 }
2316
2317 void
2318 icmp6_fasttimo(void)
2319 {
2320
2321 mld_fasttimo();
2322 }
2323
2324 void
2325 icmp6_slowtimo(void)
2326 {
2327
2328 mld_slowtimo();
2329 }
2330
2331 static const char *
2332 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2333 struct in6_addr *tgt6)
2334 {
2335 static char buf[1024];
2336 char ip6bufs[INET6_ADDRSTRLEN];
2337 char ip6bufd[INET6_ADDRSTRLEN];
2338 char ip6buft[INET6_ADDRSTRLEN];
2339 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2340 ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2341 ip6_sprintf(ip6buft, tgt6));
2342 return buf;
2343 }
2344
2345 void
2346 icmp6_redirect_input(struct mbuf *m, int off)
2347 {
2348 struct ifnet *ifp;
2349 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2350 struct nd_redirect *nd_rd;
2351 int icmp6len = ntohs(ip6->ip6_plen);
2352 char *lladdr = NULL;
2353 int lladdrlen = 0;
2354 u_char *redirhdr = NULL;
2355 int redirhdrlen = 0;
2356 struct rtentry *rt = NULL;
2357 int is_router;
2358 int is_onlink;
2359 struct in6_addr src6 = ip6->ip6_src;
2360 struct in6_addr redtgt6;
2361 struct in6_addr reddst6;
2362 union nd_opts ndopts;
2363 char ip6buf[INET6_ADDRSTRLEN];
2364
2365 if (!m)
2366 return;
2367
2368 ifp = m->m_pkthdr.rcvif;
2369
2370 if (!ifp)
2371 return;
2372
2373 /* XXX if we are router, we don't update route by icmp6 redirect */
2374 if (V_ip6_forwarding)
2375 goto freeit;
2376 if (!V_icmp6_rediraccept)
2377 goto freeit;
2378
2379 #ifndef PULLDOWN_TEST
2380 IP6_EXTHDR_CHECK(m, off, icmp6len,);
2381 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2382 #else
2383 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2384 if (nd_rd == NULL) {
2385 ICMP6STAT_INC(icp6s_tooshort);
2386 return;
2387 }
2388 #endif
2389 redtgt6 = nd_rd->nd_rd_target;
2390 reddst6 = nd_rd->nd_rd_dst;
2391
2392 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2393 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2394 goto freeit;
2395 }
2396
2397 /* validation */
2398 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2399 nd6log((LOG_ERR,
2400 "ICMP6 redirect sent from %s rejected; "
2401 "must be from linklocal\n",
2402 ip6_sprintf(ip6buf, &src6)));
2403 goto bad;
2404 }
2405 if (ip6->ip6_hlim != 255) {
2406 nd6log((LOG_ERR,
2407 "ICMP6 redirect sent from %s rejected; "
2408 "hlim=%d (must be 255)\n",
2409 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2410 goto bad;
2411 }
2412 {
2413 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2414 struct sockaddr_in6 sin6;
2415 struct in6_addr *gw6;
2416
2417 bzero(&sin6, sizeof(sin6));
2418 sin6.sin6_family = AF_INET6;
2419 sin6.sin6_len = sizeof(struct sockaddr_in6);
2420 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2421 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
2422 if (rt) {
2423 if (rt->rt_gateway == NULL ||
2424 rt->rt_gateway->sa_family != AF_INET6) {
2425 nd6log((LOG_ERR,
2426 "ICMP6 redirect rejected; no route "
2427 "with inet6 gateway found for redirect dst: %s\n",
2428 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2429 RTFREE_LOCKED(rt);
2430 goto bad;
2431 }
2432
2433 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2434 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2435 nd6log((LOG_ERR,
2436 "ICMP6 redirect rejected; "
2437 "not equal to gw-for-src=%s (must be same): "
2438 "%s\n",
2439 ip6_sprintf(ip6buf, gw6),
2440 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2441 RTFREE_LOCKED(rt);
2442 goto bad;
2443 }
2444 } else {
2445 nd6log((LOG_ERR,
2446 "ICMP6 redirect rejected; "
2447 "no route found for redirect dst: %s\n",
2448 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2449 goto bad;
2450 }
2451 RTFREE_LOCKED(rt);
2452 rt = NULL;
2453 }
2454 if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2455 nd6log((LOG_ERR,
2456 "ICMP6 redirect rejected; "
2457 "redirect dst must be unicast: %s\n",
2458 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2459 goto bad;
2460 }
2461
2462 is_router = is_onlink = 0;
2463 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2464 is_router = 1; /* router case */
2465 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2466 is_onlink = 1; /* on-link destination case */
2467 if (!is_router && !is_onlink) {
2468 nd6log((LOG_ERR,
2469 "ICMP6 redirect rejected; "
2470 "neither router case nor onlink case: %s\n",
2471 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2472 goto bad;
2473 }
2474 /* validation passed */
2475
2476 icmp6len -= sizeof(*nd_rd);
2477 nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2478 if (nd6_options(&ndopts) < 0) {
2479 nd6log((LOG_INFO, "icmp6_redirect_input: "
2480 "invalid ND option, rejected: %s\n",
2481 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2482 /* nd6_options have incremented stats */
2483 goto freeit;
2484 }
2485
2486 if (ndopts.nd_opts_tgt_lladdr) {
2487 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2488 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2489 }
2490
2491 if (ndopts.nd_opts_rh) {
2492 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2493 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2494 }
2495
2496 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2497 nd6log((LOG_INFO,
2498 "icmp6_redirect_input: lladdrlen mismatch for %s "
2499 "(if %d, icmp6 packet %d): %s\n",
2500 ip6_sprintf(ip6buf, &redtgt6),
2501 ifp->if_addrlen, lladdrlen - 2,
2502 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2503 goto bad;
2504 }
2505
2506 /* RFC 2461 8.3 */
2507 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2508 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2509
2510 if (!is_onlink) { /* better router case. perform rtredirect. */
2511 /* perform rtredirect */
2512 struct sockaddr_in6 sdst;
2513 struct sockaddr_in6 sgw;
2514 struct sockaddr_in6 ssrc;
2515
2516 bzero(&sdst, sizeof(sdst));
2517 bzero(&sgw, sizeof(sgw));
2518 bzero(&ssrc, sizeof(ssrc));
2519 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2520 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2521 sizeof(struct sockaddr_in6);
2522 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2523 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2524 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2525 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2526 (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2527 (struct sockaddr *)&ssrc);
2528 }
2529 /* finally update cached route in each socket via pfctlinput */
2530 {
2531 struct sockaddr_in6 sdst;
2532
2533 bzero(&sdst, sizeof(sdst));
2534 sdst.sin6_family = AF_INET6;
2535 sdst.sin6_len = sizeof(struct sockaddr_in6);
2536 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2537 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2538 #ifdef IPSEC
2539 key_sa_routechange((struct sockaddr *)&sdst);
2540 #endif /* IPSEC */
2541 }
2542
2543 freeit:
2544 m_freem(m);
2545 return;
2546
2547 bad:
2548 ICMP6STAT_INC(icp6s_badredirect);
2549 m_freem(m);
2550 }
2551
2552 void
2553 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2554 {
2555 struct ifnet *ifp; /* my outgoing interface */
2556 struct in6_addr *ifp_ll6;
2557 struct in6_addr *router_ll6;
2558 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */
2559 struct mbuf *m = NULL; /* newly allocated one */
2560 struct m_tag *mtag;
2561 struct ip6_hdr *ip6; /* m as struct ip6_hdr */
2562 struct nd_redirect *nd_rd;
2563 struct llentry *ln = NULL;
2564 size_t maxlen;
2565 u_char *p;
2566 struct ifnet *outif = NULL;
2567 struct sockaddr_in6 src_sa;
2568
2569 icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2570
2571 /* if we are not router, we don't send icmp6 redirect */
2572 if (!V_ip6_forwarding)
2573 goto fail;
2574
2575 /* sanity check */
2576 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2577 goto fail;
2578
2579 /*
2580 * Address check:
2581 * the source address must identify a neighbor, and
2582 * the destination address must not be a multicast address
2583 * [RFC 2461, sec 8.2]
2584 */
2585 sip6 = mtod(m0, struct ip6_hdr *);
2586 bzero(&src_sa, sizeof(src_sa));
2587 src_sa.sin6_family = AF_INET6;
2588 src_sa.sin6_len = sizeof(src_sa);
2589 src_sa.sin6_addr = sip6->ip6_src;
2590 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2591 goto fail;
2592 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2593 goto fail; /* what should we do here? */
2594
2595 /* rate limit */
2596 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2597 goto fail;
2598
2599 /*
2600 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2601 * we almost always ask for an mbuf cluster for simplicity.
2602 * (MHLEN < IPV6_MMTU is almost always true)
2603 */
2604 #if IPV6_MMTU >= MCLBYTES
2605 # error assumption failed about IPV6_MMTU and MCLBYTES
2606 #endif
2607 MGETHDR(m, M_DONTWAIT, MT_HEADER);
2608 if (m && IPV6_MMTU >= MHLEN)
2609 MCLGET(m, M_DONTWAIT);
2610 if (!m)
2611 goto fail;
2612 m->m_pkthdr.rcvif = NULL;
2613 m->m_len = 0;
2614 maxlen = M_TRAILINGSPACE(m);
2615 maxlen = min(IPV6_MMTU, maxlen);
2616 /* just for safety */
2617 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2618 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2619 goto fail;
2620 }
2621
2622 {
2623 /* get ip6 linklocal address for ifp(my outgoing interface). */
2624 struct in6_ifaddr *ia;
2625 if ((ia = in6ifa_ifpforlinklocal(ifp,
2626 IN6_IFF_NOTREADY|
2627 IN6_IFF_ANYCAST)) == NULL)
2628 goto fail;
2629 ifp_ll6 = &ia->ia_addr.sin6_addr;
2630 /* XXXRW: reference released prematurely. */
2631 ifa_free(&ia->ia_ifa);
2632 }
2633
2634 /* get ip6 linklocal address for the router. */
2635 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2636 struct sockaddr_in6 *sin6;
2637 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2638 router_ll6 = &sin6->sin6_addr;
2639 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2640 router_ll6 = (struct in6_addr *)NULL;
2641 } else
2642 router_ll6 = (struct in6_addr *)NULL;
2643
2644 /* ip6 */
2645 ip6 = mtod(m, struct ip6_hdr *);
2646 ip6->ip6_flow = 0;
2647 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2648 ip6->ip6_vfc |= IPV6_VERSION;
2649 /* ip6->ip6_plen will be set later */
2650 ip6->ip6_nxt = IPPROTO_ICMPV6;
2651 ip6->ip6_hlim = 255;
2652 /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2653 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2654 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2655
2656 /* ND Redirect */
2657 nd_rd = (struct nd_redirect *)(ip6 + 1);
2658 nd_rd->nd_rd_type = ND_REDIRECT;
2659 nd_rd->nd_rd_code = 0;
2660 nd_rd->nd_rd_reserved = 0;
2661 if (rt->rt_flags & RTF_GATEWAY) {
2662 /*
2663 * nd_rd->nd_rd_target must be a link-local address in
2664 * better router cases.
2665 */
2666 if (!router_ll6)
2667 goto fail;
2668 bcopy(router_ll6, &nd_rd->nd_rd_target,
2669 sizeof(nd_rd->nd_rd_target));
2670 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2671 sizeof(nd_rd->nd_rd_dst));
2672 } else {
2673 /* make sure redtgt == reddst */
2674 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2675 sizeof(nd_rd->nd_rd_target));
2676 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2677 sizeof(nd_rd->nd_rd_dst));
2678 }
2679
2680 p = (u_char *)(nd_rd + 1);
2681
2682 if (!router_ll6)
2683 goto nolladdropt;
2684
2685 {
2686 /* target lladdr option */
2687 int len;
2688 struct nd_opt_hdr *nd_opt;
2689 char *lladdr;
2690
2691 IF_AFDATA_LOCK(ifp);
2692 ln = nd6_lookup(router_ll6, 0, ifp);
2693 IF_AFDATA_UNLOCK(ifp);
2694 if (ln == NULL)
2695 goto nolladdropt;
2696
2697 len = sizeof(*nd_opt) + ifp->if_addrlen;
2698 len = (len + 7) & ~7; /* round by 8 */
2699 /* safety check */
2700 if (len + (p - (u_char *)ip6) > maxlen)
2701 goto nolladdropt;
2702
2703 if (ln->la_flags & LLE_VALID) {
2704 nd_opt = (struct nd_opt_hdr *)p;
2705 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2706 nd_opt->nd_opt_len = len >> 3;
2707 lladdr = (char *)(nd_opt + 1);
2708 bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen);
2709 p += len;
2710 }
2711 }
2712 nolladdropt:
2713 if (ln != NULL)
2714 LLE_RUNLOCK(ln);
2715
2716 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2717
2718 /* just to be safe */
2719 #ifdef M_DECRYPTED /*not openbsd*/
2720 if (m0->m_flags & M_DECRYPTED)
2721 goto noredhdropt;
2722 #endif
2723 if (p - (u_char *)ip6 > maxlen)
2724 goto noredhdropt;
2725
2726 {
2727 /* redirected header option */
2728 int len;
2729 struct nd_opt_rd_hdr *nd_opt_rh;
2730
2731 /*
2732 * compute the maximum size for icmp6 redirect header option.
2733 * XXX room for auth header?
2734 */
2735 len = maxlen - (p - (u_char *)ip6);
2736 len &= ~7;
2737
2738 /* This is just for simplicity. */
2739 if (m0->m_pkthdr.len != m0->m_len) {
2740 if (m0->m_next) {
2741 m_freem(m0->m_next);
2742 m0->m_next = NULL;
2743 }
2744 m0->m_pkthdr.len = m0->m_len;
2745 }
2746
2747 /*
2748 * Redirected header option spec (RFC2461 4.6.3) talks nothing
2749 * about padding/truncate rule for the original IP packet.
2750 * From the discussion on IPv6imp in Feb 1999,
2751 * the consensus was:
2752 * - "attach as much as possible" is the goal
2753 * - pad if not aligned (original size can be guessed by
2754 * original ip6 header)
2755 * Following code adds the padding if it is simple enough,
2756 * and truncates if not.
2757 */
2758 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2759 panic("assumption failed in %s:%d", __FILE__,
2760 __LINE__);
2761
2762 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2763 /* not enough room, truncate */
2764 m0->m_pkthdr.len = m0->m_len = len -
2765 sizeof(*nd_opt_rh);
2766 } else {
2767 /* enough room, pad or truncate */
2768 size_t extra;
2769
2770 extra = m0->m_pkthdr.len % 8;
2771 if (extra) {
2772 /* pad if easy enough, truncate if not */
2773 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2774 /* pad */
2775 m0->m_len += (8 - extra);
2776 m0->m_pkthdr.len += (8 - extra);
2777 } else {
2778 /* truncate */
2779 m0->m_pkthdr.len -= extra;
2780 m0->m_len -= extra;
2781 }
2782 }
2783 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2784 m0->m_pkthdr.len = m0->m_len = len -
2785 sizeof(*nd_opt_rh);
2786 }
2787
2788 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2789 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2790 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2791 nd_opt_rh->nd_opt_rh_len = len >> 3;
2792 p += sizeof(*nd_opt_rh);
2793 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2794
2795 /* connect m0 to m */
2796 m_tag_delete_chain(m0, NULL);
2797 m0->m_flags &= ~M_PKTHDR;
2798 m->m_next = m0;
2799 m->m_pkthdr.len = m->m_len + m0->m_len;
2800 m0 = NULL;
2801 }
2802 noredhdropt:;
2803 if (m0) {
2804 m_freem(m0);
2805 m0 = NULL;
2806 }
2807
2808 /* XXX: clear embedded link IDs in the inner header */
2809 in6_clearscope(&sip6->ip6_src);
2810 in6_clearscope(&sip6->ip6_dst);
2811 in6_clearscope(&nd_rd->nd_rd_target);
2812 in6_clearscope(&nd_rd->nd_rd_dst);
2813
2814 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2815
2816 nd_rd->nd_rd_cksum = 0;
2817 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2818 sizeof(*ip6), ntohs(ip6->ip6_plen));
2819
2820 if (send_sendso_input_hook != NULL) {
2821 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
2822 M_NOWAIT);
2823 if (mtag == NULL)
2824 goto fail;
2825 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
2826 m_tag_prepend(m, mtag);
2827 }
2828
2829 /* send the packet to outside... */
2830 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2831 if (outif) {
2832 icmp6_ifstat_inc(outif, ifs6_out_msg);
2833 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2834 }
2835 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2836
2837 return;
2838
2839 fail:
2840 if (m)
2841 m_freem(m);
2842 if (m0)
2843 m_freem(m0);
2844 }
2845
2846 /*
2847 * ICMPv6 socket option processing.
2848 */
2849 int
2850 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2851 {
2852 int error = 0;
2853 int optlen;
2854 struct inpcb *inp = sotoinpcb(so);
2855 int level, op, optname;
2856
2857 if (sopt) {
2858 level = sopt->sopt_level;
2859 op = sopt->sopt_dir;
2860 optname = sopt->sopt_name;
2861 optlen = sopt->sopt_valsize;
2862 } else
2863 level = op = optname = optlen = 0;
2864
2865 if (level != IPPROTO_ICMPV6) {
2866 return EINVAL;
2867 }
2868
2869 switch (op) {
2870 case PRCO_SETOPT:
2871 switch (optname) {
2872 case ICMP6_FILTER:
2873 {
2874 struct icmp6_filter ic6f;
2875
2876 if (optlen != sizeof(ic6f)) {
2877 error = EMSGSIZE;
2878 break;
2879 }
2880 error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2881 if (error == 0) {
2882 INP_WLOCK(inp);
2883 *inp->in6p_icmp6filt = ic6f;
2884 INP_WUNLOCK(inp);
2885 }
2886 break;
2887 }
2888
2889 default:
2890 error = ENOPROTOOPT;
2891 break;
2892 }
2893 break;
2894
2895 case PRCO_GETOPT:
2896 switch (optname) {
2897 case ICMP6_FILTER:
2898 {
2899 struct icmp6_filter ic6f;
2900
2901 INP_RLOCK(inp);
2902 ic6f = *inp->in6p_icmp6filt;
2903 INP_RUNLOCK(inp);
2904 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2905 break;
2906 }
2907
2908 default:
2909 error = ENOPROTOOPT;
2910 break;
2911 }
2912 break;
2913 }
2914
2915 return (error);
2916 }
2917
2918 /*
2919 * Perform rate limit check.
2920 * Returns 0 if it is okay to send the icmp6 packet.
2921 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2922 * limitation.
2923 *
2924 * XXX per-destination/type check necessary?
2925 *
2926 * dst - not used at this moment
2927 * type - not used at this moment
2928 * code - not used at this moment
2929 */
2930 static int
2931 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2932 const int code)
2933 {
2934 int ret;
2935
2936 ret = 0; /* okay to send */
2937
2938 /* PPS limit */
2939 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2940 V_icmp6errppslim)) {
2941 /* The packet is subject to rate limit */
2942 ret++;
2943 }
2944
2945 return ret;
2946 }
Cache object: 9debba4590a775afac4db75ae8168e20
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