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: stable/9/sys/netinet6/icmp6.c 275827 2014-12-16 11:52:15Z ae $");
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(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(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(struct icmp6_nodeinfo *, struct mbuf *,
142 struct ifnet **, struct in6_addr *);
143 static int ni6_store_addrs(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
kmod_icmp6stat_inc(int statnum)155 kmod_icmp6stat_inc(int statnum)
156 {
157
158 (*((u_quad_t *)&V_icmp6stat + statnum))++;
159 }
160
161 static void
icmp6_errcount(int type,int code)162 icmp6_errcount(int type, int code)
163 {
164 switch (type) {
165 case ICMP6_DST_UNREACH:
166 switch (code) {
167 case ICMP6_DST_UNREACH_NOROUTE:
168 ICMP6STAT_INC(icp6s_odst_unreach_noroute);
169 return;
170 case ICMP6_DST_UNREACH_ADMIN:
171 ICMP6STAT_INC(icp6s_odst_unreach_admin);
172 return;
173 case ICMP6_DST_UNREACH_BEYONDSCOPE:
174 ICMP6STAT_INC(icp6s_odst_unreach_beyondscope);
175 return;
176 case ICMP6_DST_UNREACH_ADDR:
177 ICMP6STAT_INC(icp6s_odst_unreach_addr);
178 return;
179 case ICMP6_DST_UNREACH_NOPORT:
180 ICMP6STAT_INC(icp6s_odst_unreach_noport);
181 return;
182 }
183 break;
184 case ICMP6_PACKET_TOO_BIG:
185 ICMP6STAT_INC(icp6s_opacket_too_big);
186 return;
187 case ICMP6_TIME_EXCEEDED:
188 switch (code) {
189 case ICMP6_TIME_EXCEED_TRANSIT:
190 ICMP6STAT_INC(icp6s_otime_exceed_transit);
191 return;
192 case ICMP6_TIME_EXCEED_REASSEMBLY:
193 ICMP6STAT_INC(icp6s_otime_exceed_reassembly);
194 return;
195 }
196 break;
197 case ICMP6_PARAM_PROB:
198 switch (code) {
199 case ICMP6_PARAMPROB_HEADER:
200 ICMP6STAT_INC(icp6s_oparamprob_header);
201 return;
202 case ICMP6_PARAMPROB_NEXTHEADER:
203 ICMP6STAT_INC(icp6s_oparamprob_nextheader);
204 return;
205 case ICMP6_PARAMPROB_OPTION:
206 ICMP6STAT_INC(icp6s_oparamprob_option);
207 return;
208 }
209 break;
210 case ND_REDIRECT:
211 ICMP6STAT_INC(icp6s_oredirect);
212 return;
213 }
214 ICMP6STAT_INC(icp6s_ounknown);
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
icmp6_error2(struct mbuf * m,int type,int code,int param,struct ifnet * ifp)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
icmp6_error(struct mbuf * m,int type,int code,int param)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(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); /* FIB is also copied over. */
364 if (m == NULL) {
365 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
366 return;
367 }
368
369 nip6 = mtod(m, struct ip6_hdr *);
370 nip6->ip6_src = oip6->ip6_src;
371 nip6->ip6_dst = oip6->ip6_dst;
372
373 in6_clearscope(&oip6->ip6_src);
374 in6_clearscope(&oip6->ip6_dst);
375
376 icmp6 = (struct icmp6_hdr *)(nip6 + 1);
377 icmp6->icmp6_type = type;
378 icmp6->icmp6_code = code;
379 icmp6->icmp6_pptr = htonl((u_int32_t)param);
380
381 /*
382 * icmp6_reflect() is designed to be in the input path.
383 * icmp6_error() can be called from both input and output path,
384 * and if we are in output path rcvif could contain bogus value.
385 * clear m->m_pkthdr.rcvif for safety, we should have enough scope
386 * information in ip header (nip6).
387 */
388 m->m_pkthdr.rcvif = NULL;
389
390 ICMP6STAT_INC(icp6s_outhist[type]);
391 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
392
393 return;
394
395 freeit:
396 /*
397 * If we can't tell whether or not we can generate ICMP6, free it.
398 */
399 m_freem(m);
400 }
401
402 /*
403 * Process a received ICMP6 message.
404 */
405 int
icmp6_input(struct mbuf ** mp,int * offp,int proto)406 icmp6_input(struct mbuf **mp, int *offp, int proto)
407 {
408 struct mbuf *m = *mp, *n;
409 struct ifnet *ifp;
410 struct ip6_hdr *ip6, *nip6;
411 struct icmp6_hdr *icmp6, *nicmp6;
412 int off = *offp;
413 int icmp6len = m->m_pkthdr.len - *offp;
414 int code, sum, noff;
415 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
416 int ip6len, error;
417
418 ifp = m->m_pkthdr.rcvif;
419
420 #ifndef PULLDOWN_TEST
421 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
422 /* m might change if M_LOOP. So, call mtod after this */
423 #endif
424
425 /*
426 * Locate icmp6 structure in mbuf, and check
427 * that not corrupted and of at least minimum length
428 */
429
430 ip6 = mtod(m, struct ip6_hdr *);
431 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
432 if (icmp6len < sizeof(struct icmp6_hdr)) {
433 ICMP6STAT_INC(icp6s_tooshort);
434 goto freeit;
435 }
436
437 /*
438 * Check multicast group membership.
439 * Note: SSM filters are not applied for ICMPv6 traffic.
440 */
441 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
442 struct in6_multi *inm;
443
444 inm = in6m_lookup(ifp, &ip6->ip6_dst);
445 if (inm == NULL) {
446 IP6STAT_INC(ip6s_notmember);
447 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
448 goto freeit;
449 }
450 }
451
452 /*
453 * calculate the checksum
454 */
455 #ifndef PULLDOWN_TEST
456 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
457 #else
458 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
459 if (icmp6 == NULL) {
460 ICMP6STAT_INC(icp6s_tooshort);
461 return IPPROTO_DONE;
462 }
463 #endif
464 code = icmp6->icmp6_code;
465
466 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
467 nd6log((LOG_ERR,
468 "ICMP6 checksum error(%d|%x) %s\n",
469 icmp6->icmp6_type, sum,
470 ip6_sprintf(ip6bufs, &ip6->ip6_src)));
471 ICMP6STAT_INC(icp6s_checksum);
472 goto freeit;
473 }
474
475 if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
476 /*
477 * Deliver very specific ICMP6 type only.
478 * This is important to deliver TOOBIG. Otherwise PMTUD
479 * will not work.
480 */
481 switch (icmp6->icmp6_type) {
482 case ICMP6_DST_UNREACH:
483 case ICMP6_PACKET_TOO_BIG:
484 case ICMP6_TIME_EXCEEDED:
485 break;
486 default:
487 goto freeit;
488 }
489 }
490
491 ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
492 icmp6_ifstat_inc(ifp, ifs6_in_msg);
493 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
494 icmp6_ifstat_inc(ifp, ifs6_in_error);
495
496 switch (icmp6->icmp6_type) {
497 case ICMP6_DST_UNREACH:
498 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
499 switch (code) {
500 case ICMP6_DST_UNREACH_NOROUTE:
501 code = PRC_UNREACH_NET;
502 break;
503 case ICMP6_DST_UNREACH_ADMIN:
504 icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
505 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
506 break;
507 case ICMP6_DST_UNREACH_ADDR:
508 code = PRC_HOSTDEAD;
509 break;
510 case ICMP6_DST_UNREACH_BEYONDSCOPE:
511 /* I mean "source address was incorrect." */
512 code = PRC_PARAMPROB;
513 break;
514 case ICMP6_DST_UNREACH_NOPORT:
515 code = PRC_UNREACH_PORT;
516 break;
517 default:
518 goto badcode;
519 }
520 goto deliver;
521 break;
522
523 case ICMP6_PACKET_TOO_BIG:
524 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
525
526 /* validation is made in icmp6_mtudisc_update */
527
528 code = PRC_MSGSIZE;
529
530 /*
531 * Updating the path MTU will be done after examining
532 * intermediate extension headers.
533 */
534 goto deliver;
535 break;
536
537 case ICMP6_TIME_EXCEEDED:
538 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
539 switch (code) {
540 case ICMP6_TIME_EXCEED_TRANSIT:
541 code = PRC_TIMXCEED_INTRANS;
542 break;
543 case ICMP6_TIME_EXCEED_REASSEMBLY:
544 code = PRC_TIMXCEED_REASS;
545 break;
546 default:
547 goto badcode;
548 }
549 goto deliver;
550 break;
551
552 case ICMP6_PARAM_PROB:
553 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
554 switch (code) {
555 case ICMP6_PARAMPROB_NEXTHEADER:
556 code = PRC_UNREACH_PROTOCOL;
557 break;
558 case ICMP6_PARAMPROB_HEADER:
559 case ICMP6_PARAMPROB_OPTION:
560 code = PRC_PARAMPROB;
561 break;
562 default:
563 goto badcode;
564 }
565 goto deliver;
566 break;
567
568 case ICMP6_ECHO_REQUEST:
569 icmp6_ifstat_inc(ifp, ifs6_in_echo);
570 if (code != 0)
571 goto badcode;
572 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
573 /* Give up remote */
574 break;
575 }
576 if ((n->m_flags & M_EXT) != 0
577 || n->m_len < off + sizeof(struct icmp6_hdr)) {
578 struct mbuf *n0 = n;
579 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
580 int n0len;
581
582 MGETHDR(n, M_DONTWAIT, n0->m_type);
583 n0len = n0->m_pkthdr.len; /* save for use below */
584 if (n)
585 M_MOVE_PKTHDR(n, n0); /* FIB copied. */
586 if (n && maxlen >= MHLEN) {
587 MCLGET(n, M_DONTWAIT);
588 if ((n->m_flags & M_EXT) == 0) {
589 m_free(n);
590 n = NULL;
591 }
592 }
593 if (n == NULL) {
594 /* Give up remote */
595 m_freem(n0);
596 break;
597 }
598 /*
599 * Copy IPv6 and ICMPv6 only.
600 */
601 nip6 = mtod(n, struct ip6_hdr *);
602 bcopy(ip6, nip6, sizeof(struct ip6_hdr));
603 nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
604 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
605 noff = sizeof(struct ip6_hdr);
606 /* new mbuf contains only ipv6+icmpv6 headers */
607 n->m_len = noff + sizeof(struct icmp6_hdr);
608 /*
609 * Adjust mbuf. ip6_plen will be adjusted in
610 * ip6_output().
611 */
612 m_adj(n0, off + sizeof(struct icmp6_hdr));
613 /* recalculate complete packet size */
614 n->m_pkthdr.len = n0len + (noff - off);
615 n->m_next = n0;
616 } else {
617 nip6 = mtod(n, struct ip6_hdr *);
618 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
619 sizeof(*nicmp6));
620 noff = off;
621 }
622 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
623 nicmp6->icmp6_code = 0;
624 if (n) {
625 ICMP6STAT_INC(icp6s_reflect);
626 ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
627 icmp6_reflect(n, noff);
628 }
629 break;
630
631 case ICMP6_ECHO_REPLY:
632 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
633 if (code != 0)
634 goto badcode;
635 break;
636
637 case MLD_LISTENER_QUERY:
638 case MLD_LISTENER_REPORT:
639 case MLD_LISTENER_DONE:
640 case MLDV2_LISTENER_REPORT:
641 /*
642 * Drop MLD traffic which is not link-local, has a hop limit
643 * of greater than 1 hop, or which does not have the
644 * IPv6 HBH Router Alert option.
645 * As IPv6 HBH options are stripped in ip6_input() we must
646 * check an mbuf header flag.
647 * XXX Should we also sanity check that these messages
648 * were directed to a link-local multicast prefix?
649 */
650 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
651 goto freeit;
652 if (mld_input(m, off, icmp6len) != 0)
653 return (IPPROTO_DONE);
654 /* m stays. */
655 break;
656
657 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */
658 {
659 enum { WRU, FQDN } mode;
660
661 if (!V_icmp6_nodeinfo)
662 break;
663
664 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
665 mode = WRU;
666 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
667 mode = FQDN;
668 else
669 goto badlen;
670
671 if (mode == FQDN) {
672 #ifndef PULLDOWN_TEST
673 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
674 IPPROTO_DONE);
675 #endif
676 n = m_copy(m, 0, M_COPYALL);
677 if (n)
678 n = ni6_input(n, off);
679 /* XXX meaningless if n == NULL */
680 noff = sizeof(struct ip6_hdr);
681 } else {
682 struct prison *pr;
683 u_char *p;
684 int maxlen, maxhlen, hlen;
685
686 /*
687 * XXX: this combination of flags is pointless,
688 * but should we keep this for compatibility?
689 */
690 if ((V_icmp6_nodeinfo & 5) != 5)
691 break;
692
693 if (code != 0)
694 goto badcode;
695 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
696 if (maxlen >= MCLBYTES) {
697 /* Give up remote */
698 break;
699 }
700 MGETHDR(n, M_DONTWAIT, m->m_type);
701 if (n && maxlen > MHLEN) {
702 MCLGET(n, M_DONTWAIT);
703 if ((n->m_flags & M_EXT) == 0) {
704 m_free(n);
705 n = NULL;
706 }
707 }
708 if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) {
709 /*
710 * Previous code did a blind M_COPY_PKTHDR
711 * and said "just for rcvif". If true, then
712 * we could tolerate the dup failing (due to
713 * the deep copy of the tag chain). For now
714 * be conservative and just fail.
715 */
716 m_free(n);
717 n = NULL;
718 }
719 if (n == NULL) {
720 /* Give up remote */
721 break;
722 }
723 n->m_pkthdr.rcvif = NULL;
724 n->m_len = 0;
725 maxhlen = M_TRAILINGSPACE(n) - maxlen;
726 pr = curthread->td_ucred->cr_prison;
727 mtx_lock(&pr->pr_mtx);
728 hlen = strlen(pr->pr_hostname);
729 if (maxhlen > hlen)
730 maxhlen = hlen;
731 /*
732 * Copy IPv6 and ICMPv6 only.
733 */
734 nip6 = mtod(n, struct ip6_hdr *);
735 bcopy(ip6, nip6, sizeof(struct ip6_hdr));
736 nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
737 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
738 p = (u_char *)(nicmp6 + 1);
739 bzero(p, 4);
740 /* meaningless TTL */
741 bcopy(pr->pr_hostname, p + 4, maxhlen);
742 mtx_unlock(&pr->pr_mtx);
743 noff = sizeof(struct ip6_hdr);
744 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
745 sizeof(struct icmp6_hdr) + 4 + maxhlen;
746 nicmp6->icmp6_type = ICMP6_WRUREPLY;
747 nicmp6->icmp6_code = 0;
748 }
749 if (n) {
750 ICMP6STAT_INC(icp6s_reflect);
751 ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
752 icmp6_reflect(n, noff);
753 }
754 break;
755 }
756
757 case ICMP6_WRUREPLY:
758 if (code != 0)
759 goto badcode;
760 break;
761
762 case ND_ROUTER_SOLICIT:
763 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
764 if (code != 0)
765 goto badcode;
766 if (icmp6len < sizeof(struct nd_router_solicit))
767 goto badlen;
768 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
769 /* give up local */
770
771 /* Send incoming SeND packet to user space. */
772 if (send_sendso_input_hook != NULL) {
773 IP6_EXTHDR_CHECK(m, off,
774 icmp6len, IPPROTO_DONE);
775 error = send_sendso_input_hook(m, ifp,
776 SND_IN, ip6len);
777 /* -1 == no app on SEND socket */
778 if (error == 0)
779 return (IPPROTO_DONE);
780 nd6_rs_input(m, off, icmp6len);
781 } else
782 nd6_rs_input(m, off, icmp6len);
783 m = NULL;
784 goto freeit;
785 }
786 if (send_sendso_input_hook != NULL) {
787 IP6_EXTHDR_CHECK(n, off,
788 icmp6len, IPPROTO_DONE);
789 error = send_sendso_input_hook(n, ifp,
790 SND_IN, ip6len);
791 if (error == 0)
792 goto freeit;
793 /* -1 == no app on SEND socket */
794 nd6_rs_input(n, off, icmp6len);
795 } else
796 nd6_rs_input(n, off, icmp6len);
797 /* m stays. */
798 break;
799
800 case ND_ROUTER_ADVERT:
801 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
802 if (code != 0)
803 goto badcode;
804 if (icmp6len < sizeof(struct nd_router_advert))
805 goto badlen;
806 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
807
808 /* Send incoming SeND-protected/ND packet to user space. */
809 if (send_sendso_input_hook != NULL) {
810 error = send_sendso_input_hook(m, ifp,
811 SND_IN, ip6len);
812 if (error == 0)
813 return (IPPROTO_DONE);
814 nd6_ra_input(m, off, icmp6len);
815 } else
816 nd6_ra_input(m, off, icmp6len);
817 m = NULL;
818 goto freeit;
819 }
820 if (send_sendso_input_hook != NULL) {
821 error = send_sendso_input_hook(n, ifp,
822 SND_IN, ip6len);
823 if (error == 0)
824 goto freeit;
825 nd6_ra_input(n, off, icmp6len);
826 } else
827 nd6_ra_input(n, off, icmp6len);
828 /* m stays. */
829 break;
830
831 case ND_NEIGHBOR_SOLICIT:
832 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
833 if (code != 0)
834 goto badcode;
835 if (icmp6len < sizeof(struct nd_neighbor_solicit))
836 goto badlen;
837 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
838 if (send_sendso_input_hook != NULL) {
839 error = send_sendso_input_hook(m, ifp,
840 SND_IN, ip6len);
841 if (error == 0)
842 return (IPPROTO_DONE);
843 nd6_ns_input(m, off, icmp6len);
844 } else
845 nd6_ns_input(m, off, icmp6len);
846 m = NULL;
847 goto freeit;
848 }
849 if (send_sendso_input_hook != NULL) {
850 error = send_sendso_input_hook(n, ifp,
851 SND_IN, ip6len);
852 if (error == 0)
853 goto freeit;
854 nd6_ns_input(n, off, icmp6len);
855 } else
856 nd6_ns_input(n, off, icmp6len);
857 /* m stays. */
858 break;
859
860 case ND_NEIGHBOR_ADVERT:
861 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
862 if (code != 0)
863 goto badcode;
864 if (icmp6len < sizeof(struct nd_neighbor_advert))
865 goto badlen;
866 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
867
868 /* Send incoming SeND-protected/ND packet to user space. */
869 if (send_sendso_input_hook != NULL) {
870 error = send_sendso_input_hook(m, ifp,
871 SND_IN, ip6len);
872 if (error == 0)
873 return (IPPROTO_DONE);
874 nd6_na_input(m, off, icmp6len);
875 } else
876 nd6_na_input(m, off, icmp6len);
877 m = NULL;
878 goto freeit;
879 }
880 if (send_sendso_input_hook != NULL) {
881 error = send_sendso_input_hook(n, ifp,
882 SND_IN, ip6len);
883 if (error == 0)
884 goto freeit;
885 nd6_na_input(n, off, icmp6len);
886 } else
887 nd6_na_input(n, off, icmp6len);
888 /* m stays. */
889 break;
890
891 case ND_REDIRECT:
892 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
893 if (code != 0)
894 goto badcode;
895 if (icmp6len < sizeof(struct nd_redirect))
896 goto badlen;
897 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
898 if (send_sendso_input_hook != NULL) {
899 error = send_sendso_input_hook(m, ifp,
900 SND_IN, ip6len);
901 if (error == 0)
902 return (IPPROTO_DONE);
903 icmp6_redirect_input(m, off);
904 } else
905 icmp6_redirect_input(m, off);
906 m = NULL;
907 goto freeit;
908 }
909 if (send_sendso_input_hook != NULL) {
910 error = send_sendso_input_hook(n, ifp,
911 SND_IN, ip6len);
912 if (error == 0)
913 goto freeit;
914 icmp6_redirect_input(n, off);
915 } else
916 icmp6_redirect_input(n, off);
917 /* m stays. */
918 break;
919
920 case ICMP6_ROUTER_RENUMBERING:
921 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
922 code != ICMP6_ROUTER_RENUMBERING_RESULT)
923 goto badcode;
924 if (icmp6len < sizeof(struct icmp6_router_renum))
925 goto badlen;
926 break;
927
928 default:
929 nd6log((LOG_DEBUG,
930 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
931 icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
932 ip6_sprintf(ip6bufd, &ip6->ip6_dst),
933 ifp ? ifp->if_index : 0));
934 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
935 /* ICMPv6 error: MUST deliver it by spec... */
936 code = PRC_NCMDS;
937 /* deliver */
938 } else {
939 /* ICMPv6 informational: MUST not deliver */
940 break;
941 }
942 deliver:
943 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
944 /* In this case, m should've been freed. */
945 return (IPPROTO_DONE);
946 }
947 break;
948
949 badcode:
950 ICMP6STAT_INC(icp6s_badcode);
951 break;
952
953 badlen:
954 ICMP6STAT_INC(icp6s_badlen);
955 break;
956 }
957
958 /* deliver the packet to appropriate sockets */
959 icmp6_rip6_input(&m, *offp);
960
961 return IPPROTO_DONE;
962
963 freeit:
964 m_freem(m);
965 return IPPROTO_DONE;
966 }
967
968 static int
icmp6_notify_error(struct mbuf ** mp,int off,int icmp6len,int code)969 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
970 {
971 struct mbuf *m = *mp;
972 struct icmp6_hdr *icmp6;
973 struct ip6_hdr *eip6;
974 u_int32_t notifymtu;
975 struct sockaddr_in6 icmp6src, icmp6dst;
976
977 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
978 ICMP6STAT_INC(icp6s_tooshort);
979 goto freeit;
980 }
981 #ifndef PULLDOWN_TEST
982 IP6_EXTHDR_CHECK(m, off,
983 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
984 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
985 #else
986 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
987 sizeof(*icmp6) + sizeof(struct ip6_hdr));
988 if (icmp6 == NULL) {
989 ICMP6STAT_INC(icp6s_tooshort);
990 return (-1);
991 }
992 #endif
993 eip6 = (struct ip6_hdr *)(icmp6 + 1);
994
995 /* Detect the upper level protocol */
996 {
997 void (*ctlfunc)(int, struct sockaddr *, void *);
998 u_int8_t nxt = eip6->ip6_nxt;
999 int eoff = off + sizeof(struct icmp6_hdr) +
1000 sizeof(struct ip6_hdr);
1001 struct ip6ctlparam ip6cp;
1002 struct in6_addr *finaldst = NULL;
1003 int icmp6type = icmp6->icmp6_type;
1004 struct ip6_frag *fh;
1005 struct ip6_rthdr *rth;
1006 struct ip6_rthdr0 *rth0;
1007 int rthlen;
1008
1009 while (1) { /* XXX: should avoid infinite loop explicitly? */
1010 struct ip6_ext *eh;
1011
1012 switch (nxt) {
1013 case IPPROTO_HOPOPTS:
1014 case IPPROTO_DSTOPTS:
1015 case IPPROTO_AH:
1016 #ifndef PULLDOWN_TEST
1017 IP6_EXTHDR_CHECK(m, 0,
1018 eoff + sizeof(struct ip6_ext), -1);
1019 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
1020 #else
1021 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
1022 eoff, sizeof(*eh));
1023 if (eh == NULL) {
1024 ICMP6STAT_INC(icp6s_tooshort);
1025 return (-1);
1026 }
1027 #endif
1028
1029 if (nxt == IPPROTO_AH)
1030 eoff += (eh->ip6e_len + 2) << 2;
1031 else
1032 eoff += (eh->ip6e_len + 1) << 3;
1033 nxt = eh->ip6e_nxt;
1034 break;
1035 case IPPROTO_ROUTING:
1036 /*
1037 * When the erroneous packet contains a
1038 * routing header, we should examine the
1039 * header to determine the final destination.
1040 * Otherwise, we can't properly update
1041 * information that depends on the final
1042 * destination (e.g. path MTU).
1043 */
1044 #ifndef PULLDOWN_TEST
1045 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
1046 rth = (struct ip6_rthdr *)
1047 (mtod(m, caddr_t) + eoff);
1048 #else
1049 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
1050 eoff, sizeof(*rth));
1051 if (rth == NULL) {
1052 ICMP6STAT_INC(icp6s_tooshort);
1053 return (-1);
1054 }
1055 #endif
1056 rthlen = (rth->ip6r_len + 1) << 3;
1057 /*
1058 * XXX: currently there is no
1059 * officially defined type other
1060 * than type-0.
1061 * Note that if the segment left field
1062 * is 0, all intermediate hops must
1063 * have been passed.
1064 */
1065 if (rth->ip6r_segleft &&
1066 rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
1067 int hops;
1068
1069 #ifndef PULLDOWN_TEST
1070 IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
1071 rth0 = (struct ip6_rthdr0 *)
1072 (mtod(m, caddr_t) + eoff);
1073 #else
1074 IP6_EXTHDR_GET(rth0,
1075 struct ip6_rthdr0 *, m,
1076 eoff, rthlen);
1077 if (rth0 == NULL) {
1078 ICMP6STAT_INC(icp6s_tooshort);
1079 return (-1);
1080 }
1081 #endif
1082 /* just ignore a bogus header */
1083 if ((rth0->ip6r0_len % 2) == 0 &&
1084 (hops = rth0->ip6r0_len/2))
1085 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
1086 }
1087 eoff += rthlen;
1088 nxt = rth->ip6r_nxt;
1089 break;
1090 case IPPROTO_FRAGMENT:
1091 #ifndef PULLDOWN_TEST
1092 IP6_EXTHDR_CHECK(m, 0, eoff +
1093 sizeof(struct ip6_frag), -1);
1094 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1095 eoff);
1096 #else
1097 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1098 eoff, sizeof(*fh));
1099 if (fh == NULL) {
1100 ICMP6STAT_INC(icp6s_tooshort);
1101 return (-1);
1102 }
1103 #endif
1104 /*
1105 * Data after a fragment header is meaningless
1106 * unless it is the first fragment, but
1107 * we'll go to the notify label for path MTU
1108 * discovery.
1109 */
1110 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1111 goto notify;
1112
1113 eoff += sizeof(struct ip6_frag);
1114 nxt = fh->ip6f_nxt;
1115 break;
1116 default:
1117 /*
1118 * This case includes ESP and the No Next
1119 * Header. In such cases going to the notify
1120 * label does not have any meaning
1121 * (i.e. ctlfunc will be NULL), but we go
1122 * anyway since we might have to update
1123 * path MTU information.
1124 */
1125 goto notify;
1126 }
1127 }
1128 notify:
1129 #ifndef PULLDOWN_TEST
1130 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1131 #else
1132 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1133 sizeof(*icmp6) + sizeof(struct ip6_hdr));
1134 if (icmp6 == NULL) {
1135 ICMP6STAT_INC(icp6s_tooshort);
1136 return (-1);
1137 }
1138 #endif
1139
1140 /*
1141 * retrieve parameters from the inner IPv6 header, and convert
1142 * them into sockaddr structures.
1143 * XXX: there is no guarantee that the source or destination
1144 * addresses of the inner packet are in the same scope as
1145 * the addresses of the icmp packet. But there is no other
1146 * way to determine the zone.
1147 */
1148 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1149
1150 bzero(&icmp6dst, sizeof(icmp6dst));
1151 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1152 icmp6dst.sin6_family = AF_INET6;
1153 if (finaldst == NULL)
1154 icmp6dst.sin6_addr = eip6->ip6_dst;
1155 else
1156 icmp6dst.sin6_addr = *finaldst;
1157 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1158 goto freeit;
1159 bzero(&icmp6src, sizeof(icmp6src));
1160 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1161 icmp6src.sin6_family = AF_INET6;
1162 icmp6src.sin6_addr = eip6->ip6_src;
1163 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1164 goto freeit;
1165 icmp6src.sin6_flowinfo =
1166 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1167
1168 if (finaldst == NULL)
1169 finaldst = &eip6->ip6_dst;
1170 ip6cp.ip6c_m = m;
1171 ip6cp.ip6c_icmp6 = icmp6;
1172 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1173 ip6cp.ip6c_off = eoff;
1174 ip6cp.ip6c_finaldst = finaldst;
1175 ip6cp.ip6c_src = &icmp6src;
1176 ip6cp.ip6c_nxt = nxt;
1177
1178 m_addr_changed(m);
1179
1180 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1181 notifymtu = ntohl(icmp6->icmp6_mtu);
1182 ip6cp.ip6c_cmdarg = (void *)¬ifymtu;
1183 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/
1184 }
1185
1186 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1187 (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1188 if (ctlfunc) {
1189 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1190 &ip6cp);
1191 }
1192 }
1193 *mp = m;
1194 return (0);
1195
1196 freeit:
1197 m_freem(m);
1198 return (-1);
1199 }
1200
1201 void
icmp6_mtudisc_update(struct ip6ctlparam * ip6cp,int validated)1202 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1203 {
1204 struct in6_addr *dst = ip6cp->ip6c_finaldst;
1205 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1206 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1207 u_int mtu = ntohl(icmp6->icmp6_mtu);
1208 struct in_conninfo inc;
1209
1210 #if 0
1211 /*
1212 * RFC2460 section 5, last paragraph.
1213 * even though minimum link MTU for IPv6 is IPV6_MMTU,
1214 * we may see ICMPv6 too big with mtu < IPV6_MMTU
1215 * due to packet translator in the middle.
1216 * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1217 * special handling.
1218 */
1219 if (mtu < IPV6_MMTU)
1220 return;
1221 #endif
1222
1223 /*
1224 * we reject ICMPv6 too big with abnormally small value.
1225 * XXX what is the good definition of "abnormally small"?
1226 */
1227 if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1228 return;
1229
1230 if (!validated)
1231 return;
1232
1233 /*
1234 * In case the suggested mtu is less than IPV6_MMTU, we
1235 * only need to remember that it was for above mentioned
1236 * "alwaysfrag" case.
1237 * Try to be as close to the spec as possible.
1238 */
1239 if (mtu < IPV6_MMTU)
1240 mtu = IPV6_MMTU - 8;
1241
1242 bzero(&inc, sizeof(inc));
1243 inc.inc_fibnum = M_GETFIB(m);
1244 inc.inc_flags |= INC_ISIPV6;
1245 inc.inc6_faddr = *dst;
1246 if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1247 return;
1248
1249 if (mtu < tcp_maxmtu6(&inc, NULL)) {
1250 tcp_hc_updatemtu(&inc, mtu);
1251 ICMP6STAT_INC(icp6s_pmtuchg);
1252 }
1253 }
1254
1255 /*
1256 * Process a Node Information Query packet, based on
1257 * draft-ietf-ipngwg-icmp-name-lookups-07.
1258 *
1259 * Spec incompatibilities:
1260 * - IPv6 Subject address handling
1261 * - IPv4 Subject address handling support missing
1262 * - Proxy reply (answer even if it's not for me)
1263 * - joins NI group address at in6_ifattach() time only, does not cope
1264 * with hostname changes by sethostname(3)
1265 */
1266 static struct mbuf *
ni6_input(struct mbuf * m,int off)1267 ni6_input(struct mbuf *m, int off)
1268 {
1269 struct icmp6_nodeinfo *ni6, *nni6;
1270 struct mbuf *n = NULL;
1271 struct prison *pr;
1272 u_int16_t qtype;
1273 int subjlen;
1274 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1275 struct ni_reply_fqdn *fqdn;
1276 int addrs; /* for NI_QTYPE_NODEADDR */
1277 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1278 struct in6_addr in6_subj; /* subject address */
1279 struct ip6_hdr *ip6;
1280 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */
1281 char *subj = NULL;
1282 struct in6_ifaddr *ia6 = NULL;
1283
1284 ip6 = mtod(m, struct ip6_hdr *);
1285 #ifndef PULLDOWN_TEST
1286 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1287 #else
1288 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1289 if (ni6 == NULL) {
1290 /* m is already reclaimed */
1291 return (NULL);
1292 }
1293 #endif
1294
1295 /*
1296 * Validate IPv6 source address.
1297 * The default configuration MUST be to refuse answering queries from
1298 * global-scope addresses according to RFC4602.
1299 * Notes:
1300 * - it's not very clear what "refuse" means; this implementation
1301 * simply drops it.
1302 * - it's not very easy to identify global-scope (unicast) addresses
1303 * since there are many prefixes for them. It should be safer
1304 * and in practice sufficient to check "all" but loopback and
1305 * link-local (note that site-local unicast was deprecated and
1306 * ULA is defined as global scope-wise)
1307 */
1308 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1309 !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1310 !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1311 goto bad;
1312
1313 /*
1314 * Validate IPv6 destination address.
1315 *
1316 * The Responder must discard the Query without further processing
1317 * unless it is one of the Responder's unicast or anycast addresses, or
1318 * a link-local scope multicast address which the Responder has joined.
1319 * [RFC4602, Section 5.]
1320 */
1321 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1322 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1323 goto bad;
1324 /* else it's a link-local multicast, fine */
1325 } else { /* unicast or anycast */
1326 if ((ia6 = ip6_getdstifaddr(m)) == NULL)
1327 goto bad; /* XXX impossible */
1328
1329 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1330 !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1331 ifa_free(&ia6->ia_ifa);
1332 nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1333 "a temporary address in %s:%d",
1334 __FILE__, __LINE__));
1335 goto bad;
1336 }
1337 ifa_free(&ia6->ia_ifa);
1338 }
1339
1340 /* validate query Subject field. */
1341 qtype = ntohs(ni6->ni_qtype);
1342 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1343 switch (qtype) {
1344 case NI_QTYPE_NOOP:
1345 case NI_QTYPE_SUPTYPES:
1346 /* 07 draft */
1347 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1348 break;
1349 /* FALLTHROUGH */
1350 case NI_QTYPE_FQDN:
1351 case NI_QTYPE_NODEADDR:
1352 case NI_QTYPE_IPV4ADDR:
1353 switch (ni6->ni_code) {
1354 case ICMP6_NI_SUBJ_IPV6:
1355 #if ICMP6_NI_SUBJ_IPV6 != 0
1356 case 0:
1357 #endif
1358 /*
1359 * backward compatibility - try to accept 03 draft
1360 * format, where no Subject is present.
1361 */
1362 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1363 subjlen == 0) {
1364 oldfqdn++;
1365 break;
1366 }
1367 #if ICMP6_NI_SUBJ_IPV6 != 0
1368 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1369 goto bad;
1370 #endif
1371
1372 if (subjlen != sizeof(struct in6_addr))
1373 goto bad;
1374
1375 /*
1376 * Validate Subject address.
1377 *
1378 * Not sure what exactly "address belongs to the node"
1379 * means in the spec, is it just unicast, or what?
1380 *
1381 * At this moment we consider Subject address as
1382 * "belong to the node" if the Subject address equals
1383 * to the IPv6 destination address; validation for
1384 * IPv6 destination address should have done enough
1385 * check for us.
1386 *
1387 * We do not do proxy at this moment.
1388 */
1389 /* m_pulldown instead of copy? */
1390 m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1391 subjlen, (caddr_t)&in6_subj);
1392 if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1393 goto bad;
1394
1395 subj = (char *)&in6_subj;
1396 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1397 break;
1398
1399 /*
1400 * XXX if we are to allow other cases, we should really
1401 * be careful about scope here.
1402 * basically, we should disallow queries toward IPv6
1403 * destination X with subject Y,
1404 * if scope(X) > scope(Y).
1405 * if we allow scope(X) > scope(Y), it will result in
1406 * information leakage across scope boundary.
1407 */
1408 goto bad;
1409
1410 case ICMP6_NI_SUBJ_FQDN:
1411 /*
1412 * Validate Subject name with gethostname(3).
1413 *
1414 * The behavior may need some debate, since:
1415 * - we are not sure if the node has FQDN as
1416 * hostname (returned by gethostname(3)).
1417 * - the code does wildcard match for truncated names.
1418 * however, we are not sure if we want to perform
1419 * wildcard match, if gethostname(3) side has
1420 * truncated hostname.
1421 */
1422 pr = curthread->td_ucred->cr_prison;
1423 mtx_lock(&pr->pr_mtx);
1424 n = ni6_nametodns(pr->pr_hostname,
1425 strlen(pr->pr_hostname), 0);
1426 mtx_unlock(&pr->pr_mtx);
1427 if (!n || n->m_next || n->m_len == 0)
1428 goto bad;
1429 IP6_EXTHDR_GET(subj, char *, m,
1430 off + sizeof(struct icmp6_nodeinfo), subjlen);
1431 if (subj == NULL)
1432 goto bad;
1433 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1434 n->m_len)) {
1435 goto bad;
1436 }
1437 m_freem(n);
1438 n = NULL;
1439 break;
1440
1441 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */
1442 default:
1443 goto bad;
1444 }
1445 break;
1446 }
1447
1448 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */
1449 switch (qtype) {
1450 case NI_QTYPE_FQDN:
1451 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1452 goto bad;
1453 break;
1454 case NI_QTYPE_NODEADDR:
1455 case NI_QTYPE_IPV4ADDR:
1456 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1457 goto bad;
1458 break;
1459 }
1460
1461 /* guess reply length */
1462 switch (qtype) {
1463 case NI_QTYPE_NOOP:
1464 break; /* no reply data */
1465 case NI_QTYPE_SUPTYPES:
1466 replylen += sizeof(u_int32_t);
1467 break;
1468 case NI_QTYPE_FQDN:
1469 /* XXX will append an mbuf */
1470 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1471 break;
1472 case NI_QTYPE_NODEADDR:
1473 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1474 if ((replylen += addrs * (sizeof(struct in6_addr) +
1475 sizeof(u_int32_t))) > MCLBYTES)
1476 replylen = MCLBYTES; /* XXX: will truncate pkt later */
1477 break;
1478 case NI_QTYPE_IPV4ADDR:
1479 /* unsupported - should respond with unknown Qtype? */
1480 break;
1481 default:
1482 /*
1483 * XXX: We must return a reply with the ICMP6 code
1484 * `unknown Qtype' in this case. However we regard the case
1485 * as an FQDN query for backward compatibility.
1486 * Older versions set a random value to this field,
1487 * so it rarely varies in the defined qtypes.
1488 * But the mechanism is not reliable...
1489 * maybe we should obsolete older versions.
1490 */
1491 qtype = NI_QTYPE_FQDN;
1492 /* XXX will append an mbuf */
1493 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1494 oldfqdn++;
1495 break;
1496 }
1497
1498 /* allocate an mbuf to reply. */
1499 MGETHDR(n, M_DONTWAIT, m->m_type);
1500 if (n == NULL) {
1501 m_freem(m);
1502 return (NULL);
1503 }
1504 M_MOVE_PKTHDR(n, m); /* just for recvif and FIB */
1505 if (replylen > MHLEN) {
1506 if (replylen > MCLBYTES) {
1507 /*
1508 * XXX: should we try to allocate more? But MCLBYTES
1509 * is probably much larger than IPV6_MMTU...
1510 */
1511 goto bad;
1512 }
1513 MCLGET(n, M_DONTWAIT);
1514 if ((n->m_flags & M_EXT) == 0) {
1515 goto bad;
1516 }
1517 }
1518 n->m_pkthdr.len = n->m_len = replylen;
1519
1520 /* copy mbuf header and IPv6 + Node Information base headers */
1521 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1522 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1523 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1524
1525 /* qtype dependent procedure */
1526 switch (qtype) {
1527 case NI_QTYPE_NOOP:
1528 nni6->ni_code = ICMP6_NI_SUCCESS;
1529 nni6->ni_flags = 0;
1530 break;
1531 case NI_QTYPE_SUPTYPES:
1532 {
1533 u_int32_t v;
1534 nni6->ni_code = ICMP6_NI_SUCCESS;
1535 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1536 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1537 v = (u_int32_t)htonl(0x0000000f);
1538 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1539 break;
1540 }
1541 case NI_QTYPE_FQDN:
1542 nni6->ni_code = ICMP6_NI_SUCCESS;
1543 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1544 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1545 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1546 fqdn->ni_fqdn_ttl = 0; /* ditto. */
1547 /*
1548 * XXX do we really have FQDN in hostname?
1549 */
1550 pr = curthread->td_ucred->cr_prison;
1551 mtx_lock(&pr->pr_mtx);
1552 n->m_next = ni6_nametodns(pr->pr_hostname,
1553 strlen(pr->pr_hostname), oldfqdn);
1554 mtx_unlock(&pr->pr_mtx);
1555 if (n->m_next == NULL)
1556 goto bad;
1557 /* XXX we assume that n->m_next is not a chain */
1558 if (n->m_next->m_next != NULL)
1559 goto bad;
1560 n->m_pkthdr.len += n->m_next->m_len;
1561 break;
1562 case NI_QTYPE_NODEADDR:
1563 {
1564 int lenlim, copied;
1565
1566 nni6->ni_code = ICMP6_NI_SUCCESS;
1567 n->m_pkthdr.len = n->m_len =
1568 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1569 lenlim = M_TRAILINGSPACE(n);
1570 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1571 /* XXX: reset mbuf length */
1572 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1573 sizeof(struct icmp6_nodeinfo) + copied;
1574 break;
1575 }
1576 default:
1577 break; /* XXX impossible! */
1578 }
1579
1580 nni6->ni_type = ICMP6_NI_REPLY;
1581 m_freem(m);
1582 return (n);
1583
1584 bad:
1585 m_freem(m);
1586 if (n)
1587 m_freem(n);
1588 return (NULL);
1589 }
1590
1591 /*
1592 * make a mbuf with DNS-encoded string. no compression support.
1593 *
1594 * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1595 * treated as truncated name (two \0 at the end). this is a wild guess.
1596 *
1597 * old - return pascal string if non-zero
1598 */
1599 static struct mbuf *
ni6_nametodns(const char * name,int namelen,int old)1600 ni6_nametodns(const char *name, int namelen, int old)
1601 {
1602 struct mbuf *m;
1603 char *cp, *ep;
1604 const char *p, *q;
1605 int i, len, nterm;
1606
1607 if (old)
1608 len = namelen + 1;
1609 else
1610 len = MCLBYTES;
1611
1612 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1613 MGET(m, M_DONTWAIT, MT_DATA);
1614 if (m && len > MLEN) {
1615 MCLGET(m, M_DONTWAIT);
1616 if ((m->m_flags & M_EXT) == 0)
1617 goto fail;
1618 }
1619 if (!m)
1620 goto fail;
1621 m->m_next = NULL;
1622
1623 if (old) {
1624 m->m_len = len;
1625 *mtod(m, char *) = namelen;
1626 bcopy(name, mtod(m, char *) + 1, namelen);
1627 return m;
1628 } else {
1629 m->m_len = 0;
1630 cp = mtod(m, char *);
1631 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1632
1633 /* if not certain about my name, return empty buffer */
1634 if (namelen == 0)
1635 return m;
1636
1637 /*
1638 * guess if it looks like shortened hostname, or FQDN.
1639 * shortened hostname needs two trailing "\0".
1640 */
1641 i = 0;
1642 for (p = name; p < name + namelen; p++) {
1643 if (*p && *p == '.')
1644 i++;
1645 }
1646 if (i < 2)
1647 nterm = 2;
1648 else
1649 nterm = 1;
1650
1651 p = name;
1652 while (cp < ep && p < name + namelen) {
1653 i = 0;
1654 for (q = p; q < name + namelen && *q && *q != '.'; q++)
1655 i++;
1656 /* result does not fit into mbuf */
1657 if (cp + i + 1 >= ep)
1658 goto fail;
1659 /*
1660 * DNS label length restriction, RFC1035 page 8.
1661 * "i == 0" case is included here to avoid returning
1662 * 0-length label on "foo..bar".
1663 */
1664 if (i <= 0 || i >= 64)
1665 goto fail;
1666 *cp++ = i;
1667 bcopy(p, cp, i);
1668 cp += i;
1669 p = q;
1670 if (p < name + namelen && *p == '.')
1671 p++;
1672 }
1673 /* termination */
1674 if (cp + nterm >= ep)
1675 goto fail;
1676 while (nterm-- > 0)
1677 *cp++ = '\0';
1678 m->m_len = cp - mtod(m, char *);
1679 return m;
1680 }
1681
1682 panic("should not reach here");
1683 /* NOTREACHED */
1684
1685 fail:
1686 if (m)
1687 m_freem(m);
1688 return NULL;
1689 }
1690
1691 /*
1692 * check if two DNS-encoded string matches. takes care of truncated
1693 * form (with \0\0 at the end). no compression support.
1694 * XXX upper/lowercase match (see RFC2065)
1695 */
1696 static int
ni6_dnsmatch(const char * a,int alen,const char * b,int blen)1697 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1698 {
1699 const char *a0, *b0;
1700 int l;
1701
1702 /* simplest case - need validation? */
1703 if (alen == blen && bcmp(a, b, alen) == 0)
1704 return 1;
1705
1706 a0 = a;
1707 b0 = b;
1708
1709 /* termination is mandatory */
1710 if (alen < 2 || blen < 2)
1711 return 0;
1712 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1713 return 0;
1714 alen--;
1715 blen--;
1716
1717 while (a - a0 < alen && b - b0 < blen) {
1718 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1719 return 0;
1720
1721 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1722 return 0;
1723 /* we don't support compression yet */
1724 if (a[0] >= 64 || b[0] >= 64)
1725 return 0;
1726
1727 /* truncated case */
1728 if (a[0] == 0 && a - a0 == alen - 1)
1729 return 1;
1730 if (b[0] == 0 && b - b0 == blen - 1)
1731 return 1;
1732 if (a[0] == 0 || b[0] == 0)
1733 return 0;
1734
1735 if (a[0] != b[0])
1736 return 0;
1737 l = a[0];
1738 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1739 return 0;
1740 if (bcmp(a + 1, b + 1, l) != 0)
1741 return 0;
1742
1743 a += 1 + l;
1744 b += 1 + l;
1745 }
1746
1747 if (a - a0 == alen && b - b0 == blen)
1748 return 1;
1749 else
1750 return 0;
1751 }
1752
1753 /*
1754 * calculate the number of addresses to be returned in the node info reply.
1755 */
1756 static int
ni6_addrs(struct icmp6_nodeinfo * ni6,struct mbuf * m,struct ifnet ** ifpp,struct in6_addr * subj)1757 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1758 struct in6_addr *subj)
1759 {
1760 struct ifnet *ifp;
1761 struct in6_ifaddr *ifa6;
1762 struct ifaddr *ifa;
1763 int addrs = 0, addrsofif, iffound = 0;
1764 int niflags = ni6->ni_flags;
1765
1766 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1767 switch (ni6->ni_code) {
1768 case ICMP6_NI_SUBJ_IPV6:
1769 if (subj == NULL) /* must be impossible... */
1770 return (0);
1771 break;
1772 default:
1773 /*
1774 * XXX: we only support IPv6 subject address for
1775 * this Qtype.
1776 */
1777 return (0);
1778 }
1779 }
1780
1781 IFNET_RLOCK_NOSLEEP();
1782 TAILQ_FOREACH(ifp, &V_ifnet, if_list) {
1783 addrsofif = 0;
1784 IF_ADDR_RLOCK(ifp);
1785 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1786 if (ifa->ifa_addr->sa_family != AF_INET6)
1787 continue;
1788 ifa6 = (struct in6_ifaddr *)ifa;
1789
1790 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1791 IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1792 iffound = 1;
1793
1794 /*
1795 * IPv4-mapped addresses can only be returned by a
1796 * Node Information proxy, since they represent
1797 * addresses of IPv4-only nodes, which perforce do
1798 * not implement this protocol.
1799 * [icmp-name-lookups-07, Section 5.4]
1800 * So we don't support NI_NODEADDR_FLAG_COMPAT in
1801 * this function at this moment.
1802 */
1803
1804 /* What do we have to do about ::1? */
1805 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1806 case IPV6_ADDR_SCOPE_LINKLOCAL:
1807 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1808 continue;
1809 break;
1810 case IPV6_ADDR_SCOPE_SITELOCAL:
1811 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1812 continue;
1813 break;
1814 case IPV6_ADDR_SCOPE_GLOBAL:
1815 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1816 continue;
1817 break;
1818 default:
1819 continue;
1820 }
1821
1822 /*
1823 * check if anycast is okay.
1824 * XXX: just experimental. not in the spec.
1825 */
1826 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1827 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1828 continue; /* we need only unicast addresses */
1829 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1830 (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1831 continue;
1832 }
1833 addrsofif++; /* count the address */
1834 }
1835 IF_ADDR_RUNLOCK(ifp);
1836 if (iffound) {
1837 *ifpp = ifp;
1838 IFNET_RUNLOCK_NOSLEEP();
1839 return (addrsofif);
1840 }
1841
1842 addrs += addrsofif;
1843 }
1844 IFNET_RUNLOCK_NOSLEEP();
1845
1846 return (addrs);
1847 }
1848
1849 static int
ni6_store_addrs(struct icmp6_nodeinfo * ni6,struct icmp6_nodeinfo * nni6,struct ifnet * ifp0,int resid)1850 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1851 struct ifnet *ifp0, int resid)
1852 {
1853 struct ifnet *ifp;
1854 struct in6_ifaddr *ifa6;
1855 struct ifaddr *ifa;
1856 struct ifnet *ifp_dep = NULL;
1857 int copied = 0, allow_deprecated = 0;
1858 u_char *cp = (u_char *)(nni6 + 1);
1859 int niflags = ni6->ni_flags;
1860 u_int32_t ltime;
1861
1862 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1863 return (0); /* needless to copy */
1864
1865 IFNET_RLOCK_NOSLEEP();
1866 ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
1867 again:
1868
1869 for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1870 IF_ADDR_RLOCK(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_RUNLOCK(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_RUNLOCK(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
icmp6_rip6_input(struct mbuf ** mp,int off)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
icmp6_reflect(struct mbuf * m,size_t off)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
icmp6_fasttimo(void)2318 icmp6_fasttimo(void)
2319 {
2320
2321 mld_fasttimo();
2322 }
2323
2324 void
icmp6_slowtimo(void)2325 icmp6_slowtimo(void)
2326 {
2327
2328 mld_slowtimo();
2329 }
2330
2331 static const char *
icmp6_redirect_diag(struct in6_addr * src6,struct in6_addr * dst6,struct in6_addr * tgt6)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
icmp6_redirect_input(struct mbuf * m,int off)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 struct rtentry *rt = NULL;
2355 int is_router;
2356 int is_onlink;
2357 struct in6_addr src6 = ip6->ip6_src;
2358 struct in6_addr redtgt6;
2359 struct in6_addr reddst6;
2360 union nd_opts ndopts;
2361 char ip6buf[INET6_ADDRSTRLEN];
2362
2363 M_ASSERTPKTHDR(m);
2364 KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__));
2365
2366 ifp = m->m_pkthdr.rcvif;
2367
2368 /* XXX if we are router, we don't update route by icmp6 redirect */
2369 if (V_ip6_forwarding)
2370 goto freeit;
2371 if (!V_icmp6_rediraccept)
2372 goto freeit;
2373
2374 #ifndef PULLDOWN_TEST
2375 IP6_EXTHDR_CHECK(m, off, icmp6len,);
2376 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2377 #else
2378 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2379 if (nd_rd == NULL) {
2380 ICMP6STAT_INC(icp6s_tooshort);
2381 return;
2382 }
2383 #endif
2384 redtgt6 = nd_rd->nd_rd_target;
2385 reddst6 = nd_rd->nd_rd_dst;
2386
2387 if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2388 in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2389 goto freeit;
2390 }
2391
2392 /* validation */
2393 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2394 nd6log((LOG_ERR,
2395 "ICMP6 redirect sent from %s rejected; "
2396 "must be from linklocal\n",
2397 ip6_sprintf(ip6buf, &src6)));
2398 goto bad;
2399 }
2400 if (ip6->ip6_hlim != 255) {
2401 nd6log((LOG_ERR,
2402 "ICMP6 redirect sent from %s rejected; "
2403 "hlim=%d (must be 255)\n",
2404 ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2405 goto bad;
2406 }
2407 {
2408 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2409 struct sockaddr_in6 sin6;
2410 struct in6_addr *gw6;
2411
2412 bzero(&sin6, sizeof(sin6));
2413 sin6.sin6_family = AF_INET6;
2414 sin6.sin6_len = sizeof(struct sockaddr_in6);
2415 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2416 rt = in6_rtalloc1((struct sockaddr *)&sin6, 0, 0UL, RT_DEFAULT_FIB);
2417 if (rt) {
2418 if (rt->rt_gateway == NULL ||
2419 rt->rt_gateway->sa_family != AF_INET6) {
2420 RTFREE_LOCKED(rt);
2421 nd6log((LOG_ERR,
2422 "ICMP6 redirect rejected; no route "
2423 "with inet6 gateway found for redirect dst: %s\n",
2424 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2425 goto bad;
2426 }
2427
2428 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2429 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2430 RTFREE_LOCKED(rt);
2431 nd6log((LOG_ERR,
2432 "ICMP6 redirect rejected; "
2433 "not equal to gw-for-src=%s (must be same): "
2434 "%s\n",
2435 ip6_sprintf(ip6buf, gw6),
2436 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2437 goto bad;
2438 }
2439 } else {
2440 nd6log((LOG_ERR,
2441 "ICMP6 redirect rejected; "
2442 "no route found for redirect dst: %s\n",
2443 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2444 goto bad;
2445 }
2446 RTFREE_LOCKED(rt);
2447 rt = NULL;
2448 }
2449 if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2450 nd6log((LOG_ERR,
2451 "ICMP6 redirect rejected; "
2452 "redirect dst must be unicast: %s\n",
2453 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2454 goto bad;
2455 }
2456
2457 is_router = is_onlink = 0;
2458 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2459 is_router = 1; /* router case */
2460 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2461 is_onlink = 1; /* on-link destination case */
2462 if (!is_router && !is_onlink) {
2463 nd6log((LOG_ERR,
2464 "ICMP6 redirect rejected; "
2465 "neither router case nor onlink case: %s\n",
2466 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2467 goto bad;
2468 }
2469 /* validation passed */
2470
2471 icmp6len -= sizeof(*nd_rd);
2472 nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2473 if (nd6_options(&ndopts) < 0) {
2474 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n",
2475 __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2476 /* nd6_options have incremented stats */
2477 goto freeit;
2478 }
2479
2480 if (ndopts.nd_opts_tgt_lladdr) {
2481 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2482 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2483 }
2484
2485 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2486 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s "
2487 "(if %d, icmp6 packet %d): %s\n",
2488 __func__, ip6_sprintf(ip6buf, &redtgt6),
2489 ifp->if_addrlen, lladdrlen - 2,
2490 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2491 goto bad;
2492 }
2493
2494 /* RFC 2461 8.3 */
2495 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2496 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2497
2498 if (!is_onlink) { /* better router case. perform rtredirect. */
2499 /* perform rtredirect */
2500 struct sockaddr_in6 sdst;
2501 struct sockaddr_in6 sgw;
2502 struct sockaddr_in6 ssrc;
2503 u_int fibnum;
2504
2505 bzero(&sdst, sizeof(sdst));
2506 bzero(&sgw, sizeof(sgw));
2507 bzero(&ssrc, sizeof(ssrc));
2508 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2509 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2510 sizeof(struct sockaddr_in6);
2511 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2512 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2513 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2514 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
2515 in6_rtredirect((struct sockaddr *)&sdst,
2516 (struct sockaddr *)&sgw, (struct sockaddr *)NULL,
2517 RTF_GATEWAY | RTF_HOST, (struct sockaddr *)&ssrc,
2518 fibnum);
2519 }
2520 /* finally update cached route in each socket via pfctlinput */
2521 {
2522 struct sockaddr_in6 sdst;
2523
2524 bzero(&sdst, sizeof(sdst));
2525 sdst.sin6_family = AF_INET6;
2526 sdst.sin6_len = sizeof(struct sockaddr_in6);
2527 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2528 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2529 #ifdef IPSEC
2530 key_sa_routechange((struct sockaddr *)&sdst);
2531 #endif /* IPSEC */
2532 }
2533
2534 freeit:
2535 m_freem(m);
2536 return;
2537
2538 bad:
2539 ICMP6STAT_INC(icp6s_badredirect);
2540 m_freem(m);
2541 }
2542
2543 void
icmp6_redirect_output(struct mbuf * m0,struct rtentry * rt)2544 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2545 {
2546 struct ifnet *ifp; /* my outgoing interface */
2547 struct in6_addr *ifp_ll6;
2548 struct in6_addr *router_ll6;
2549 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */
2550 struct mbuf *m = NULL; /* newly allocated one */
2551 struct m_tag *mtag;
2552 struct ip6_hdr *ip6; /* m as struct ip6_hdr */
2553 struct nd_redirect *nd_rd;
2554 struct llentry *ln = NULL;
2555 size_t maxlen;
2556 u_char *p;
2557 struct ifnet *outif = NULL;
2558 struct sockaddr_in6 src_sa;
2559
2560 icmp6_errcount(ND_REDIRECT, 0);
2561
2562 /* if we are not router, we don't send icmp6 redirect */
2563 if (!V_ip6_forwarding)
2564 goto fail;
2565
2566 /* sanity check */
2567 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2568 goto fail;
2569
2570 /*
2571 * Address check:
2572 * the source address must identify a neighbor, and
2573 * the destination address must not be a multicast address
2574 * [RFC 2461, sec 8.2]
2575 */
2576 sip6 = mtod(m0, struct ip6_hdr *);
2577 bzero(&src_sa, sizeof(src_sa));
2578 src_sa.sin6_family = AF_INET6;
2579 src_sa.sin6_len = sizeof(src_sa);
2580 src_sa.sin6_addr = sip6->ip6_src;
2581 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2582 goto fail;
2583 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2584 goto fail; /* what should we do here? */
2585
2586 /* rate limit */
2587 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2588 goto fail;
2589
2590 /*
2591 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2592 * we almost always ask for an mbuf cluster for simplicity.
2593 * (MHLEN < IPV6_MMTU is almost always true)
2594 */
2595 #if IPV6_MMTU >= MCLBYTES
2596 # error assumption failed about IPV6_MMTU and MCLBYTES
2597 #endif
2598 MGETHDR(m, M_DONTWAIT, MT_HEADER);
2599 if (m && IPV6_MMTU >= MHLEN)
2600 MCLGET(m, M_DONTWAIT);
2601 if (!m)
2602 goto fail;
2603 M_SETFIB(m, rt->rt_fibnum);
2604 m->m_pkthdr.rcvif = NULL;
2605 m->m_len = 0;
2606 maxlen = M_TRAILINGSPACE(m);
2607 maxlen = min(IPV6_MMTU, maxlen);
2608 /* just for safety */
2609 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2610 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2611 goto fail;
2612 }
2613
2614 {
2615 /* get ip6 linklocal address for ifp(my outgoing interface). */
2616 struct in6_ifaddr *ia;
2617 if ((ia = in6ifa_ifpforlinklocal(ifp,
2618 IN6_IFF_NOTREADY|
2619 IN6_IFF_ANYCAST)) == NULL)
2620 goto fail;
2621 ifp_ll6 = &ia->ia_addr.sin6_addr;
2622 /* XXXRW: reference released prematurely. */
2623 ifa_free(&ia->ia_ifa);
2624 }
2625
2626 /* get ip6 linklocal address for the router. */
2627 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2628 struct sockaddr_in6 *sin6;
2629 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2630 router_ll6 = &sin6->sin6_addr;
2631 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2632 router_ll6 = (struct in6_addr *)NULL;
2633 } else
2634 router_ll6 = (struct in6_addr *)NULL;
2635
2636 /* ip6 */
2637 ip6 = mtod(m, struct ip6_hdr *);
2638 ip6->ip6_flow = 0;
2639 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2640 ip6->ip6_vfc |= IPV6_VERSION;
2641 /* ip6->ip6_plen will be set later */
2642 ip6->ip6_nxt = IPPROTO_ICMPV6;
2643 ip6->ip6_hlim = 255;
2644 /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2645 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2646 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2647
2648 /* ND Redirect */
2649 nd_rd = (struct nd_redirect *)(ip6 + 1);
2650 nd_rd->nd_rd_type = ND_REDIRECT;
2651 nd_rd->nd_rd_code = 0;
2652 nd_rd->nd_rd_reserved = 0;
2653 if (rt->rt_flags & RTF_GATEWAY) {
2654 /*
2655 * nd_rd->nd_rd_target must be a link-local address in
2656 * better router cases.
2657 */
2658 if (!router_ll6)
2659 goto fail;
2660 bcopy(router_ll6, &nd_rd->nd_rd_target,
2661 sizeof(nd_rd->nd_rd_target));
2662 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2663 sizeof(nd_rd->nd_rd_dst));
2664 } else {
2665 /* make sure redtgt == reddst */
2666 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2667 sizeof(nd_rd->nd_rd_target));
2668 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2669 sizeof(nd_rd->nd_rd_dst));
2670 }
2671
2672 p = (u_char *)(nd_rd + 1);
2673
2674 if (!router_ll6)
2675 goto nolladdropt;
2676
2677 {
2678 /* target lladdr option */
2679 int len;
2680 struct nd_opt_hdr *nd_opt;
2681 char *lladdr;
2682
2683 IF_AFDATA_RLOCK(ifp);
2684 ln = nd6_lookup(router_ll6, 0, ifp);
2685 IF_AFDATA_RUNLOCK(ifp);
2686 if (ln == NULL)
2687 goto nolladdropt;
2688
2689 len = sizeof(*nd_opt) + ifp->if_addrlen;
2690 len = (len + 7) & ~7; /* round by 8 */
2691 /* safety check */
2692 if (len + (p - (u_char *)ip6) > maxlen)
2693 goto nolladdropt;
2694
2695 if (ln->la_flags & LLE_VALID) {
2696 nd_opt = (struct nd_opt_hdr *)p;
2697 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2698 nd_opt->nd_opt_len = len >> 3;
2699 lladdr = (char *)(nd_opt + 1);
2700 bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen);
2701 p += len;
2702 }
2703 }
2704 nolladdropt:
2705 if (ln != NULL)
2706 LLE_RUNLOCK(ln);
2707
2708 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2709
2710 /* just to be safe */
2711 #ifdef M_DECRYPTED /*not openbsd*/
2712 if (m0->m_flags & M_DECRYPTED)
2713 goto noredhdropt;
2714 #endif
2715 if (p - (u_char *)ip6 > maxlen)
2716 goto noredhdropt;
2717
2718 {
2719 /* redirected header option */
2720 int len;
2721 struct nd_opt_rd_hdr *nd_opt_rh;
2722
2723 /*
2724 * compute the maximum size for icmp6 redirect header option.
2725 * XXX room for auth header?
2726 */
2727 len = maxlen - (p - (u_char *)ip6);
2728 len &= ~7;
2729
2730 /* This is just for simplicity. */
2731 if (m0->m_pkthdr.len != m0->m_len) {
2732 if (m0->m_next) {
2733 m_freem(m0->m_next);
2734 m0->m_next = NULL;
2735 }
2736 m0->m_pkthdr.len = m0->m_len;
2737 }
2738
2739 /*
2740 * Redirected header option spec (RFC2461 4.6.3) talks nothing
2741 * about padding/truncate rule for the original IP packet.
2742 * From the discussion on IPv6imp in Feb 1999,
2743 * the consensus was:
2744 * - "attach as much as possible" is the goal
2745 * - pad if not aligned (original size can be guessed by
2746 * original ip6 header)
2747 * Following code adds the padding if it is simple enough,
2748 * and truncates if not.
2749 */
2750 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2751 panic("assumption failed in %s:%d", __FILE__,
2752 __LINE__);
2753
2754 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2755 /* not enough room, truncate */
2756 m0->m_pkthdr.len = m0->m_len = len -
2757 sizeof(*nd_opt_rh);
2758 } else {
2759 /* enough room, pad or truncate */
2760 size_t extra;
2761
2762 extra = m0->m_pkthdr.len % 8;
2763 if (extra) {
2764 /* pad if easy enough, truncate if not */
2765 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2766 /* pad */
2767 m0->m_len += (8 - extra);
2768 m0->m_pkthdr.len += (8 - extra);
2769 } else {
2770 /* truncate */
2771 m0->m_pkthdr.len -= extra;
2772 m0->m_len -= extra;
2773 }
2774 }
2775 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2776 m0->m_pkthdr.len = m0->m_len = len -
2777 sizeof(*nd_opt_rh);
2778 }
2779
2780 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2781 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2782 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2783 nd_opt_rh->nd_opt_rh_len = len >> 3;
2784 p += sizeof(*nd_opt_rh);
2785 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2786
2787 /* connect m0 to m */
2788 m_tag_delete_chain(m0, NULL);
2789 m0->m_flags &= ~M_PKTHDR;
2790 m->m_next = m0;
2791 m->m_pkthdr.len = m->m_len + m0->m_len;
2792 m0 = NULL;
2793 }
2794 noredhdropt:;
2795 if (m0) {
2796 m_freem(m0);
2797 m0 = NULL;
2798 }
2799
2800 /* XXX: clear embedded link IDs in the inner header */
2801 in6_clearscope(&sip6->ip6_src);
2802 in6_clearscope(&sip6->ip6_dst);
2803 in6_clearscope(&nd_rd->nd_rd_target);
2804 in6_clearscope(&nd_rd->nd_rd_dst);
2805
2806 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2807
2808 nd_rd->nd_rd_cksum = 0;
2809 nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2810 sizeof(*ip6), ntohs(ip6->ip6_plen));
2811
2812 if (send_sendso_input_hook != NULL) {
2813 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
2814 M_NOWAIT);
2815 if (mtag == NULL)
2816 goto fail;
2817 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
2818 m_tag_prepend(m, mtag);
2819 }
2820
2821 /* send the packet to outside... */
2822 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2823 if (outif) {
2824 icmp6_ifstat_inc(outif, ifs6_out_msg);
2825 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2826 }
2827 ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2828
2829 return;
2830
2831 fail:
2832 if (m)
2833 m_freem(m);
2834 if (m0)
2835 m_freem(m0);
2836 }
2837
2838 /*
2839 * ICMPv6 socket option processing.
2840 */
2841 int
icmp6_ctloutput(struct socket * so,struct sockopt * sopt)2842 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2843 {
2844 int error = 0;
2845 int optlen;
2846 struct inpcb *inp = sotoinpcb(so);
2847 int level, op, optname;
2848
2849 if (sopt) {
2850 level = sopt->sopt_level;
2851 op = sopt->sopt_dir;
2852 optname = sopt->sopt_name;
2853 optlen = sopt->sopt_valsize;
2854 } else
2855 level = op = optname = optlen = 0;
2856
2857 if (level != IPPROTO_ICMPV6) {
2858 return EINVAL;
2859 }
2860
2861 switch (op) {
2862 case PRCO_SETOPT:
2863 switch (optname) {
2864 case ICMP6_FILTER:
2865 {
2866 struct icmp6_filter ic6f;
2867
2868 if (optlen != sizeof(ic6f)) {
2869 error = EMSGSIZE;
2870 break;
2871 }
2872 error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2873 if (error == 0) {
2874 INP_WLOCK(inp);
2875 *inp->in6p_icmp6filt = ic6f;
2876 INP_WUNLOCK(inp);
2877 }
2878 break;
2879 }
2880
2881 default:
2882 error = ENOPROTOOPT;
2883 break;
2884 }
2885 break;
2886
2887 case PRCO_GETOPT:
2888 switch (optname) {
2889 case ICMP6_FILTER:
2890 {
2891 struct icmp6_filter ic6f;
2892
2893 INP_RLOCK(inp);
2894 ic6f = *inp->in6p_icmp6filt;
2895 INP_RUNLOCK(inp);
2896 error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2897 break;
2898 }
2899
2900 default:
2901 error = ENOPROTOOPT;
2902 break;
2903 }
2904 break;
2905 }
2906
2907 return (error);
2908 }
2909
2910 /*
2911 * Perform rate limit check.
2912 * Returns 0 if it is okay to send the icmp6 packet.
2913 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2914 * limitation.
2915 *
2916 * XXX per-destination/type check necessary?
2917 *
2918 * dst - not used at this moment
2919 * type - not used at this moment
2920 * code - not used at this moment
2921 */
2922 static int
icmp6_ratelimit(const struct in6_addr * dst,const int type,const int code)2923 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2924 const int code)
2925 {
2926 int ret;
2927
2928 ret = 0; /* okay to send */
2929
2930 /* PPS limit */
2931 if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2932 V_icmp6errppslim)) {
2933 /* The packet is subject to rate limit */
2934 ret++;
2935 }
2936
2937 return ret;
2938 }
2939