1 /* $OpenBSD: icmp6.c,v 1.84 2005/01/17 10:18:03 itojun Exp $ */
2 /* $KAME: icmp6.c,v 1.217 2001/06/20 15:03:29 jinmei Exp $ */
3
4 /*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 /*
34 * Copyright (c) 1982, 1986, 1988, 1993
35 * The Regents of the University of California. All rights reserved.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 * 3. Neither the name of the University nor the names of its contributors
46 * may be used to endorse or promote products derived from this software
47 * without specific prior written permission.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59 * SUCH DAMAGE.
60 *
61 * @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94
62 */
63
64 #include <sys/param.h>
65 #include <sys/systm.h>
66 #include <sys/malloc.h>
67 #include <sys/mbuf.h>
68 #include <sys/protosw.h>
69 #include <sys/socket.h>
70 #include <sys/socketvar.h>
71 #include <sys/time.h>
72 #include <sys/kernel.h>
73 #include <sys/syslog.h>
74 #include <sys/domain.h>
75
76 #include <net/if.h>
77 #include <net/route.h>
78 #include <net/if_dl.h>
79 #include <net/if_types.h>
80
81 #include <netinet/in.h>
82 #include <netinet/in_var.h>
83 #include <netinet/in_systm.h>
84 #include <netinet/ip.h>
85 #include <netinet/ip6.h>
86 #include <netinet6/ip6_var.h>
87 #include <netinet/icmp6.h>
88 #include <netinet6/mld6_var.h>
89 #include <netinet/in_pcb.h>
90 #include <netinet6/nd6.h>
91 #include <netinet6/in6_ifattach.h>
92 #include <netinet6/ip6protosw.h>
93
94 #include "faith.h"
95
96 /* inpcb members */
97 #define in6pcb inpcb
98 #define in6p_laddr inp_laddr6
99 #define in6p_faddr inp_faddr6
100 #define in6p_icmp6filt inp_icmp6filt
101 #define in6p_route inp_route
102 #define in6p_socket inp_socket
103 #define in6p_flags inp_flags
104 #define in6p_moptions inp_moptions6
105 #define in6p_outputopts inp_outputopts6
106 #define in6p_ip6 inp_ipv6
107 #define in6p_flowinfo inp_flowinfo
108 #define in6p_sp inp_sp
109 #define in6p_next inp_next
110 #define in6p_prev inp_prev
111 /* macro names */
112 #define sotoin6pcb sotoinpcb
113 /* function names */
114 #define in6_pcbdetach in_pcbdetach
115 #define in6_rtchange in_rtchange
116
117 /*
118 * for KAME src sync over BSD*'s. XXX: FreeBSD (>=3) are VERY different from
119 * others...
120 */
121 #define in6p_ip6_nxt inp_ipv6.ip6_nxt
122
123 extern struct domain inet6domain;
124 extern struct ip6protosw inet6sw[];
125 extern u_char ip6_protox[];
126
127 struct icmp6stat icmp6stat;
128
129 extern struct inpcbtable rawin6pcbtable;
130 extern int icmp6errppslim;
131 static int icmp6errpps_count = 0;
132 static struct timeval icmp6errppslim_last;
133 extern int icmp6_nodeinfo;
134
135 /*
136 * List of callbacks to notify when Path MTU changes are made.
137 */
138 struct icmp6_mtudisc_callback {
139 LIST_ENTRY(icmp6_mtudisc_callback) mc_list;
140 void (*mc_func)(struct in6_addr *);
141 };
142
143 LIST_HEAD(, icmp6_mtudisc_callback) icmp6_mtudisc_callbacks =
144 LIST_HEAD_INITIALIZER(&icmp6_mtudisc_callbacks);
145
146 static struct rttimer_queue *icmp6_mtudisc_timeout_q = NULL;
147 extern int pmtu_expire;
148
149 /* XXX do these values make any sense? */
150 static int icmp6_mtudisc_hiwat = 1280;
151 static int icmp6_mtudisc_lowat = 256;
152
153 /*
154 * keep track of # of redirect routes.
155 */
156 static struct rttimer_queue *icmp6_redirect_timeout_q = NULL;
157
158 /* XXX experimental, turned off */
159 static int icmp6_redirect_hiwat = -1;
160 static int icmp6_redirect_lowat = -1;
161
162 static void icmp6_errcount(struct icmp6errstat *, int, int);
163 static int icmp6_rip6_input(struct mbuf **, int);
164 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
165 static const char *icmp6_redirect_diag(struct in6_addr *,
166 struct in6_addr *, struct in6_addr *);
167 static struct mbuf *ni6_input(struct mbuf *, int);
168 static struct mbuf *ni6_nametodns(const char *, int, int);
169 static int ni6_dnsmatch(const char *, int, const char *, int);
170 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *,
171 struct ifnet **, char *);
172 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
173 struct ifnet *, int);
174 static int icmp6_notify_error(struct mbuf *, int, int, int);
175 static struct rtentry *icmp6_mtudisc_clone(struct sockaddr *);
176 static void icmp6_mtudisc_timeout(struct rtentry *, struct rttimer *);
177 static void icmp6_redirect_timeout(struct rtentry *, struct rttimer *);
178
179 void
icmp6_init()180 icmp6_init()
181 {
182 mld6_init();
183 icmp6_mtudisc_timeout_q = rt_timer_queue_create(pmtu_expire);
184 icmp6_redirect_timeout_q = rt_timer_queue_create(icmp6_redirtimeout);
185 }
186
187 static void
icmp6_errcount(stat,type,code)188 icmp6_errcount(stat, type, code)
189 struct icmp6errstat *stat;
190 int type, code;
191 {
192 switch (type) {
193 case ICMP6_DST_UNREACH:
194 switch (code) {
195 case ICMP6_DST_UNREACH_NOROUTE:
196 stat->icp6errs_dst_unreach_noroute++;
197 return;
198 case ICMP6_DST_UNREACH_ADMIN:
199 stat->icp6errs_dst_unreach_admin++;
200 return;
201 case ICMP6_DST_UNREACH_BEYONDSCOPE:
202 stat->icp6errs_dst_unreach_beyondscope++;
203 return;
204 case ICMP6_DST_UNREACH_ADDR:
205 stat->icp6errs_dst_unreach_addr++;
206 return;
207 case ICMP6_DST_UNREACH_NOPORT:
208 stat->icp6errs_dst_unreach_noport++;
209 return;
210 }
211 break;
212 case ICMP6_PACKET_TOO_BIG:
213 stat->icp6errs_packet_too_big++;
214 return;
215 case ICMP6_TIME_EXCEEDED:
216 switch (code) {
217 case ICMP6_TIME_EXCEED_TRANSIT:
218 stat->icp6errs_time_exceed_transit++;
219 return;
220 case ICMP6_TIME_EXCEED_REASSEMBLY:
221 stat->icp6errs_time_exceed_reassembly++;
222 return;
223 }
224 break;
225 case ICMP6_PARAM_PROB:
226 switch (code) {
227 case ICMP6_PARAMPROB_HEADER:
228 stat->icp6errs_paramprob_header++;
229 return;
230 case ICMP6_PARAMPROB_NEXTHEADER:
231 stat->icp6errs_paramprob_nextheader++;
232 return;
233 case ICMP6_PARAMPROB_OPTION:
234 stat->icp6errs_paramprob_option++;
235 return;
236 }
237 break;
238 case ND_REDIRECT:
239 stat->icp6errs_redirect++;
240 return;
241 }
242 stat->icp6errs_unknown++;
243 }
244
245 /*
246 * Register a Path MTU Discovery callback.
247 */
248 void
249 icmp6_mtudisc_callback_register(func)
250 void (*func)(struct in6_addr *);
251 {
252 struct icmp6_mtudisc_callback *mc;
253
254 for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL;
255 mc = LIST_NEXT(mc, mc_list)) {
256 if (mc->mc_func == func)
257 return;
258 }
259
260 mc = malloc(sizeof(*mc), M_PCB, M_NOWAIT);
261 if (mc == NULL)
262 panic("icmp6_mtudisc_callback_register");
263
264 mc->mc_func = func;
265 LIST_INSERT_HEAD(&icmp6_mtudisc_callbacks, mc, mc_list);
266 }
267
268 /*
269 * Generate an error packet of type error in response to bad IP6 packet.
270 */
271 void
icmp6_error(m,type,code,param)272 icmp6_error(m, type, code, param)
273 struct mbuf *m;
274 int type, code, param;
275 {
276 struct ip6_hdr *oip6, *nip6;
277 struct icmp6_hdr *icmp6;
278 u_int preplen;
279 int off;
280 int nxt;
281
282 icmp6stat.icp6s_error++;
283
284 /* count per-type-code statistics */
285 icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
286
287 if (m->m_len < sizeof(struct ip6_hdr)) {
288 m = m_pullup(m, sizeof(struct ip6_hdr));
289 if (m == NULL)
290 return;
291 }
292 oip6 = mtod(m, struct ip6_hdr *);
293
294 /*
295 * If the destination address of the erroneous packet is a multicast
296 * address, or the packet was sent using link-layer multicast,
297 * we should basically suppress sending an error (RFC 2463, Section
298 * 2.4).
299 * We have two exceptions (the item e.2 in that section):
300 * - the Pakcet Too Big message can be sent for path MTU discovery.
301 * - the Parameter Problem Message that can be allowed an icmp6 error
302 * in the option type field. This check has been done in
303 * ip6_unknown_opt(), so we can just check the type and code.
304 */
305 if ((m->m_flags & (M_BCAST|M_MCAST) ||
306 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
307 (type != ICMP6_PACKET_TOO_BIG &&
308 (type != ICMP6_PARAM_PROB ||
309 code != ICMP6_PARAMPROB_OPTION)))
310 goto freeit;
311
312 /*
313 * RFC 2463, 2.4 (e.5): source address check.
314 * XXX: the case of anycast source?
315 */
316 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
317 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
318 goto freeit;
319
320 /*
321 * If we are about to send ICMPv6 against ICMPv6 error/redirect,
322 * don't do it.
323 */
324 nxt = -1;
325 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
326 if (off >= 0 && nxt == IPPROTO_ICMPV6) {
327 struct icmp6_hdr *icp;
328
329 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
330 sizeof(*icp));
331 if (icp == NULL) {
332 icmp6stat.icp6s_tooshort++;
333 return;
334 }
335 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
336 icp->icmp6_type == ND_REDIRECT) {
337 /*
338 * ICMPv6 error
339 * Special case: for redirect (which is
340 * informational) we must not send icmp6 error.
341 */
342 icmp6stat.icp6s_canterror++;
343 goto freeit;
344 } else {
345 /* ICMPv6 informational - send the error */
346 }
347 }
348 else {
349 /* non-ICMPv6 - send the error */
350 }
351
352 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
353
354 /* Finally, do rate limitation check. */
355 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
356 icmp6stat.icp6s_toofreq++;
357 goto freeit;
358 }
359
360 /*
361 * OK, ICMP6 can be generated.
362 */
363
364 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
365 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
366
367 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
368 M_PREPEND(m, preplen, M_DONTWAIT);
369 if (m && m->m_len < preplen)
370 m = m_pullup(m, preplen);
371 if (m == NULL) {
372 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
373 return;
374 }
375
376 nip6 = mtod(m, struct ip6_hdr *);
377 nip6->ip6_src = oip6->ip6_src;
378 nip6->ip6_dst = oip6->ip6_dst;
379
380 if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
381 oip6->ip6_src.s6_addr16[1] = 0;
382 if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
383 oip6->ip6_dst.s6_addr16[1] = 0;
384
385 icmp6 = (struct icmp6_hdr *)(nip6 + 1);
386 icmp6->icmp6_type = type;
387 icmp6->icmp6_code = code;
388 icmp6->icmp6_pptr = htonl((u_int32_t)param);
389
390 /*
391 * icmp6_reflect() is designed to be in the input path.
392 * icmp6_error() can be called from both input and outut path,
393 * and if we are in output path rcvif could contain bogus value.
394 * clear m->m_pkthdr.rcvif for safety, we should have enough scope
395 * information in ip header (nip6).
396 */
397 m->m_pkthdr.rcvif = NULL;
398
399 icmp6stat.icp6s_outhist[type]++;
400 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
401
402 return;
403
404 freeit:
405 /*
406 * If we can't tell wheter or not we can generate ICMP6, free it.
407 */
408 m_freem(m);
409 }
410
411 /*
412 * Process a received ICMP6 message.
413 */
414 int
icmp6_input(mp,offp,proto)415 icmp6_input(mp, offp, proto)
416 struct mbuf **mp;
417 int *offp, proto;
418 {
419 struct mbuf *m = *mp, *n;
420 struct ip6_hdr *ip6, *nip6;
421 struct icmp6_hdr *icmp6, *nicmp6;
422 int off = *offp;
423 int icmp6len = m->m_pkthdr.len - *offp;
424 int code, sum, noff;
425
426 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
427
428 /*
429 * Locate icmp6 structure in mbuf, and check
430 * that not corrupted and of at least minimum length
431 */
432
433 ip6 = mtod(m, struct ip6_hdr *);
434 if (icmp6len < sizeof(struct icmp6_hdr)) {
435 icmp6stat.icp6s_tooshort++;
436 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
437 goto freeit;
438 }
439
440 /*
441 * calculate the checksum
442 */
443 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
444 if (icmp6 == NULL) {
445 icmp6stat.icp6s_tooshort++;
446 return IPPROTO_DONE;
447 }
448 code = icmp6->icmp6_code;
449
450 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
451 nd6log((LOG_ERR,
452 "ICMP6 checksum error(%d|%x) %s\n",
453 icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src)));
454 icmp6stat.icp6s_checksum++;
455 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
456 goto freeit;
457 }
458
459 #if defined(NFAITH) && 0 < NFAITH
460 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
461 /*
462 * Deliver very specific ICMP6 type only.
463 * This is important to deliver TOOBIG. Otherwise PMTUD
464 * will not work.
465 */
466 switch (icmp6->icmp6_type) {
467 case ICMP6_DST_UNREACH:
468 case ICMP6_PACKET_TOO_BIG:
469 case ICMP6_TIME_EXCEEDED:
470 break;
471 default:
472 goto freeit;
473 }
474 }
475 #endif
476
477 icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
478
479 switch (icmp6->icmp6_type) {
480 case ICMP6_DST_UNREACH:
481 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
482 switch (code) {
483 case ICMP6_DST_UNREACH_NOROUTE:
484 code = PRC_UNREACH_NET;
485 break;
486 case ICMP6_DST_UNREACH_ADMIN:
487 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
488 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
489 break;
490 case ICMP6_DST_UNREACH_ADDR:
491 code = PRC_HOSTDEAD;
492 break;
493 #ifdef COMPAT_RFC1885
494 case ICMP6_DST_UNREACH_NOTNEIGHBOR:
495 code = PRC_UNREACH_SRCFAIL;
496 break;
497 #else
498 case ICMP6_DST_UNREACH_BEYONDSCOPE:
499 /* I mean "source address was incorrect." */
500 code = PRC_PARAMPROB;
501 break;
502 #endif
503 case ICMP6_DST_UNREACH_NOPORT:
504 code = PRC_UNREACH_PORT;
505 break;
506 default:
507 goto badcode;
508 }
509 goto deliver;
510
511 case ICMP6_PACKET_TOO_BIG:
512 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
513
514 code = PRC_MSGSIZE;
515
516 /*
517 * Updating the path MTU will be done after examining
518 * intermediate extension headers.
519 */
520 goto deliver;
521
522 case ICMP6_TIME_EXCEEDED:
523 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
524 switch (code) {
525 case ICMP6_TIME_EXCEED_TRANSIT:
526 code = PRC_TIMXCEED_INTRANS;
527 break;
528 case ICMP6_TIME_EXCEED_REASSEMBLY:
529 code = PRC_TIMXCEED_REASS;
530 break;
531 default:
532 goto badcode;
533 }
534 goto deliver;
535
536 case ICMP6_PARAM_PROB:
537 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
538 switch (code) {
539 case ICMP6_PARAMPROB_NEXTHEADER:
540 code = PRC_UNREACH_PROTOCOL;
541 break;
542 case ICMP6_PARAMPROB_HEADER:
543 case ICMP6_PARAMPROB_OPTION:
544 code = PRC_PARAMPROB;
545 break;
546 default:
547 goto badcode;
548 }
549 goto deliver;
550
551 case ICMP6_ECHO_REQUEST:
552 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
553 if (code != 0)
554 goto badcode;
555 /*
556 * Copy mbuf to send to two data paths: userland socket(s),
557 * and to the querier (echo reply).
558 * m: a copy for socket, n: a copy for querier
559 */
560 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
561 /* Give up local */
562 n = m;
563 m = NULL;
564 goto deliverecho;
565 }
566 /*
567 * If the first mbuf is shared, or the first mbuf is too short,
568 * copy the first part of the data into a fresh mbuf.
569 * Otherwise, we will wrongly overwrite both copies.
570 */
571 if ((n->m_flags & M_EXT) != 0 ||
572 n->m_len < off + sizeof(struct icmp6_hdr)) {
573 struct mbuf *n0 = n;
574 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
575
576 /*
577 * Prepare an internal mbuf. m_pullup() doesn't
578 * always copy the length we specified.
579 */
580 if (maxlen >= MCLBYTES) {
581 /* Give up remote */
582 m_freem(n0);
583 break;
584 }
585 MGETHDR(n, M_DONTWAIT, n0->m_type);
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 local */
595 m_freem(n0);
596 n = m;
597 m = NULL;
598 goto deliverecho;
599 }
600 M_MOVE_PKTHDR(n, n0);
601 /*
602 * Copy IPv6 and ICMPv6 only.
603 */
604 nip6 = mtod(n, struct ip6_hdr *);
605 bcopy(ip6, nip6, sizeof(struct ip6_hdr));
606 nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
607 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
608 noff = sizeof(struct ip6_hdr);
609 n->m_len = noff + sizeof(struct icmp6_hdr);
610 /*
611 * Adjust mbuf. ip6_plen will be adjusted in
612 * ip6_output().
613 * n->m_pkthdr.len == n0->m_pkthdr.len at this point.
614 */
615 n->m_pkthdr.len += noff + sizeof(struct icmp6_hdr);
616 n->m_pkthdr.len -= (off + sizeof(struct icmp6_hdr));
617 m_adj(n0, off + sizeof(struct icmp6_hdr));
618 n->m_next = n0;
619 } else {
620 deliverecho:
621 nip6 = mtod(n, struct ip6_hdr *);
622 IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
623 sizeof(*nicmp6));
624 noff = off;
625 }
626 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
627 nicmp6->icmp6_code = 0;
628 if (n) {
629 icmp6stat.icp6s_reflect++;
630 icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
631 icmp6_reflect(n, noff);
632 }
633 if (!m)
634 goto freeit;
635 break;
636
637 case ICMP6_ECHO_REPLY:
638 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
639 if (code != 0)
640 goto badcode;
641 break;
642
643 case MLD_LISTENER_QUERY:
644 case MLD_LISTENER_REPORT:
645 if (icmp6len < sizeof(struct mld_hdr))
646 goto badlen;
647 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
648 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
649 else
650 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
651 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
652 /* give up local */
653 mld6_input(m, off);
654 m = NULL;
655 goto freeit;
656 }
657 mld6_input(n, off);
658 /* m stays. */
659 break;
660
661 case MLD_LISTENER_DONE:
662 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
663 if (icmp6len < sizeof(struct mld_hdr)) /* necessary? */
664 goto badlen;
665 break; /* nothing to be done in kernel */
666
667 case MLD_MTRACE_RESP:
668 case MLD_MTRACE:
669 /* XXX: these two are experimental. not officially defined. */
670 /* XXX: per-interface statistics? */
671 break; /* just pass it to applications */
672
673 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */
674 {
675 enum { WRU, FQDN } mode;
676
677 if (!icmp6_nodeinfo)
678 break;
679
680 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
681 mode = WRU;
682 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
683 mode = FQDN;
684 else
685 goto badlen;
686
687 if (mode == FQDN) {
688 n = m_copym(m, 0, M_COPYALL, M_DONTWAIT);
689 if (n)
690 n = ni6_input(n, off);
691 /* XXX meaningless if n == NULL */
692 noff = sizeof(struct ip6_hdr);
693 } else {
694 u_char *p;
695 int maxlen, maxhlen;
696
697 if ((icmp6_nodeinfo & 1) == 0)
698 break;
699
700 if (code != 0)
701 goto badcode;
702 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
703 if (maxlen >= MCLBYTES) {
704 /* Give up remote */
705 break;
706 }
707 MGETHDR(n, M_DONTWAIT, m->m_type);
708 if (n && maxlen > MHLEN) {
709 MCLGET(n, M_DONTWAIT);
710 if ((n->m_flags & M_EXT) == 0) {
711 m_free(n);
712 n = NULL;
713 }
714 }
715 if (n == NULL) {
716 /* Give up remote */
717 break;
718 }
719 n->m_pkthdr.rcvif = NULL;
720 n->m_len = 0;
721 maxhlen = M_TRAILINGSPACE(n) - maxlen;
722 if (maxhlen > hostnamelen)
723 maxhlen = hostnamelen;
724 /*
725 * Copy IPv6 and ICMPv6 only.
726 */
727 nip6 = mtod(n, struct ip6_hdr *);
728 bcopy(ip6, nip6, sizeof(struct ip6_hdr));
729 nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
730 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
731 p = (u_char *)(nicmp6 + 1);
732 bzero(p, 4);
733 bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */
734 noff = sizeof(struct ip6_hdr);
735 M_DUP_PKTHDR(n, m); /* just for rcvif */
736 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
737 sizeof(struct icmp6_hdr) + 4 + maxhlen;
738 nicmp6->icmp6_type = ICMP6_WRUREPLY;
739 nicmp6->icmp6_code = 0;
740 }
741 #undef hostnamelen
742 if (n) {
743 icmp6stat.icp6s_reflect++;
744 icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
745 icmp6_reflect(n, noff);
746 }
747 break;
748 }
749
750 case ICMP6_WRUREPLY:
751 if (code != 0)
752 goto badcode;
753 break;
754
755 case ND_ROUTER_SOLICIT:
756 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
757 if (code != 0)
758 goto badcode;
759 if (icmp6len < sizeof(struct nd_router_solicit))
760 goto badlen;
761 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
762 /* give up local */
763 nd6_rs_input(m, off, icmp6len);
764 m = NULL;
765 goto freeit;
766 }
767 nd6_rs_input(n, off, icmp6len);
768 /* m stays. */
769 break;
770
771 case ND_ROUTER_ADVERT:
772 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
773 if (code != 0)
774 goto badcode;
775 if (icmp6len < sizeof(struct nd_router_advert))
776 goto badlen;
777 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
778 /* give up local */
779 nd6_ra_input(m, off, icmp6len);
780 m = NULL;
781 goto freeit;
782 }
783 nd6_ra_input(n, off, icmp6len);
784 /* m stays. */
785 break;
786
787 case ND_NEIGHBOR_SOLICIT:
788 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
789 if (code != 0)
790 goto badcode;
791 if (icmp6len < sizeof(struct nd_neighbor_solicit))
792 goto badlen;
793 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
794 /* give up local */
795 nd6_ns_input(m, off, icmp6len);
796 m = NULL;
797 goto freeit;
798 }
799 nd6_ns_input(n, off, icmp6len);
800 /* m stays. */
801 break;
802
803 case ND_NEIGHBOR_ADVERT:
804 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
805 if (code != 0)
806 goto badcode;
807 if (icmp6len < sizeof(struct nd_neighbor_advert))
808 goto badlen;
809 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
810 /* give up local */
811 nd6_na_input(m, off, icmp6len);
812 m = NULL;
813 goto freeit;
814 }
815 nd6_na_input(n, off, icmp6len);
816 /* m stays. */
817 break;
818
819 case ND_REDIRECT:
820 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
821 if (code != 0)
822 goto badcode;
823 if (icmp6len < sizeof(struct nd_redirect))
824 goto badlen;
825 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
826 /* give up local */
827 icmp6_redirect_input(m, off);
828 m = NULL;
829 goto freeit;
830 }
831 icmp6_redirect_input(n, off);
832 /* m stays. */
833 break;
834
835 case ICMP6_ROUTER_RENUMBERING:
836 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
837 code != ICMP6_ROUTER_RENUMBERING_RESULT)
838 goto badcode;
839 if (icmp6len < sizeof(struct icmp6_router_renum))
840 goto badlen;
841 break;
842
843 default:
844 nd6log((LOG_DEBUG,
845 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
846 icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src),
847 ip6_sprintf(&ip6->ip6_dst),
848 m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
849 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
850 /* ICMPv6 error: MUST deliver it by spec... */
851 code = PRC_NCMDS;
852 /* deliver */
853 } else {
854 /* ICMPv6 informational: MUST not deliver */
855 break;
856 }
857 deliver:
858 if (icmp6_notify_error(m, off, icmp6len, code)) {
859 /* In this case, m should've been freed. */
860 return (IPPROTO_DONE);
861 }
862 break;
863
864 badcode:
865 icmp6stat.icp6s_badcode++;
866 break;
867
868 badlen:
869 icmp6stat.icp6s_badlen++;
870 break;
871 }
872
873 /* deliver the packet to appropriate sockets */
874 icmp6_rip6_input(&m, *offp);
875
876 return IPPROTO_DONE;
877
878 freeit:
879 m_freem(m);
880 return IPPROTO_DONE;
881 }
882
883 static int
icmp6_notify_error(m,off,icmp6len,code)884 icmp6_notify_error(m, off, icmp6len, code)
885 struct mbuf *m;
886 int off, icmp6len, code;
887 {
888 struct icmp6_hdr *icmp6;
889 struct ip6_hdr *eip6;
890 u_int32_t notifymtu;
891 struct sockaddr_in6 icmp6src, icmp6dst;
892
893 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
894 icmp6stat.icp6s_tooshort++;
895 goto freeit;
896 }
897 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
898 sizeof(*icmp6) + sizeof(struct ip6_hdr));
899 if (icmp6 == NULL) {
900 icmp6stat.icp6s_tooshort++;
901 return (-1);
902 }
903 eip6 = (struct ip6_hdr *)(icmp6 + 1);
904
905 /* Detect the upper level protocol */
906 {
907 void (*ctlfunc)(int, struct sockaddr *, void *);
908 u_int8_t nxt = eip6->ip6_nxt;
909 int eoff = off + sizeof(struct icmp6_hdr) +
910 sizeof(struct ip6_hdr);
911 struct ip6ctlparam ip6cp;
912 struct in6_addr *finaldst = NULL;
913 int icmp6type = icmp6->icmp6_type;
914 struct ip6_frag *fh;
915 struct ip6_rthdr *rth;
916 struct ip6_rthdr0 *rth0;
917 int rthlen;
918
919 while (1) { /* XXX: should avoid infinite loop explicitly? */
920 struct ip6_ext *eh;
921
922 switch (nxt) {
923 case IPPROTO_HOPOPTS:
924 case IPPROTO_DSTOPTS:
925 case IPPROTO_AH:
926 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
927 eoff, sizeof(*eh));
928 if (eh == NULL) {
929 icmp6stat.icp6s_tooshort++;
930 return (-1);
931 }
932
933 if (nxt == IPPROTO_AH)
934 eoff += (eh->ip6e_len + 2) << 2;
935 else
936 eoff += (eh->ip6e_len + 1) << 3;
937 nxt = eh->ip6e_nxt;
938 break;
939 case IPPROTO_ROUTING:
940 /*
941 * When the erroneous packet contains a
942 * routing header, we should examine the
943 * header to determine the final destination.
944 * Otherwise, we can't properly update
945 * information that depends on the final
946 * destination (e.g. path MTU).
947 */
948 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
949 eoff, sizeof(*rth));
950 if (rth == NULL) {
951 icmp6stat.icp6s_tooshort++;
952 return (-1);
953 }
954 rthlen = (rth->ip6r_len + 1) << 3;
955 /*
956 * XXX: currently there is no
957 * officially defined type other
958 * than type-0.
959 * Note that if the segment left field
960 * is 0, all intermediate hops must
961 * have been passed.
962 */
963 if (rth->ip6r_segleft &&
964 rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
965 int hops;
966
967 IP6_EXTHDR_GET(rth0,
968 struct ip6_rthdr0 *, m,
969 eoff, rthlen);
970 if (rth0 == NULL) {
971 icmp6stat.icp6s_tooshort++;
972 return (-1);
973 }
974 /* just ignore a bogus header */
975 if ((rth0->ip6r0_len % 2) == 0 &&
976 (hops = rth0->ip6r0_len/2))
977 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
978 }
979 eoff += rthlen;
980 nxt = rth->ip6r_nxt;
981 break;
982 case IPPROTO_FRAGMENT:
983 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
984 eoff, sizeof(*fh));
985 if (fh == NULL) {
986 icmp6stat.icp6s_tooshort++;
987 return (-1);
988 }
989 /*
990 * Data after a fragment header is meaningless
991 * unless it is the first fragment, but
992 * we'll go to the notify label for path MTU
993 * discovery.
994 */
995 if (fh->ip6f_offlg & IP6F_OFF_MASK)
996 goto notify;
997
998 eoff += sizeof(struct ip6_frag);
999 nxt = fh->ip6f_nxt;
1000 break;
1001 default:
1002 /*
1003 * This case includes ESP and the No Next
1004 * Header. In such cases going to the notify
1005 * label does not have any meaning
1006 * (i.e. ctlfunc will be NULL), but we go
1007 * anyway since we might have to update
1008 * path MTU information.
1009 */
1010 goto notify;
1011 }
1012 }
1013 notify:
1014 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1015 sizeof(*icmp6) + sizeof(struct ip6_hdr));
1016 if (icmp6 == NULL) {
1017 icmp6stat.icp6s_tooshort++;
1018 return (-1);
1019 }
1020
1021 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1022 bzero(&icmp6dst, sizeof(icmp6dst));
1023 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1024 icmp6dst.sin6_family = AF_INET6;
1025 if (finaldst == NULL)
1026 icmp6dst.sin6_addr = eip6->ip6_dst;
1027 else
1028 icmp6dst.sin6_addr = *finaldst;
1029 icmp6dst.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1030 &icmp6dst.sin6_addr);
1031 #ifndef SCOPEDROUTING
1032 if (in6_embedscope(&icmp6dst.sin6_addr, &icmp6dst,
1033 NULL, NULL)) {
1034 /* should be impossbile */
1035 nd6log((LOG_DEBUG,
1036 "icmp6_notify_error: in6_embedscope failed\n"));
1037 goto freeit;
1038 }
1039 #endif
1040
1041 /*
1042 * retrieve parameters from the inner IPv6 header, and convert
1043 * them into sockaddr structures.
1044 */
1045 bzero(&icmp6src, sizeof(icmp6src));
1046 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1047 icmp6src.sin6_family = AF_INET6;
1048 icmp6src.sin6_addr = eip6->ip6_src;
1049 icmp6src.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1050 &icmp6src.sin6_addr);
1051 #ifndef SCOPEDROUTING
1052 if (in6_embedscope(&icmp6src.sin6_addr, &icmp6src,
1053 NULL, NULL)) {
1054 /* should be impossbile */
1055 nd6log((LOG_DEBUG,
1056 "icmp6_notify_error: in6_embedscope failed\n"));
1057 goto freeit;
1058 }
1059 #endif
1060 icmp6src.sin6_flowinfo =
1061 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1062
1063 if (finaldst == NULL)
1064 finaldst = &eip6->ip6_dst;
1065 ip6cp.ip6c_m = m;
1066 ip6cp.ip6c_icmp6 = icmp6;
1067 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1068 ip6cp.ip6c_off = eoff;
1069 ip6cp.ip6c_finaldst = finaldst;
1070 ip6cp.ip6c_src = &icmp6src;
1071 ip6cp.ip6c_nxt = nxt;
1072
1073 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1074 notifymtu = ntohl(icmp6->icmp6_mtu);
1075 ip6cp.ip6c_cmdarg = (void *)¬ifymtu;
1076 }
1077
1078 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1079 (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1080 if (ctlfunc) {
1081 (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1082 &ip6cp);
1083 }
1084 }
1085 return (0);
1086
1087 freeit:
1088 m_freem(m);
1089 return (-1);
1090 }
1091
1092 void
icmp6_mtudisc_update(ip6cp,validated)1093 icmp6_mtudisc_update(ip6cp, validated)
1094 struct ip6ctlparam *ip6cp;
1095 int validated;
1096 {
1097 unsigned long rtcount;
1098 struct icmp6_mtudisc_callback *mc;
1099 struct in6_addr *dst = ip6cp->ip6c_finaldst;
1100 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1101 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1102 u_int mtu = ntohl(icmp6->icmp6_mtu);
1103 struct rtentry *rt = NULL;
1104 struct sockaddr_in6 sin6;
1105
1106 /*
1107 * allow non-validated cases if memory is plenty, to make traffic
1108 * from non-connected pcb happy.
1109 */
1110 rtcount = rt_timer_count(icmp6_mtudisc_timeout_q);
1111 if (validated) {
1112 if (0 <= icmp6_mtudisc_hiwat && rtcount > icmp6_mtudisc_hiwat)
1113 return;
1114 else if (0 <= icmp6_mtudisc_lowat &&
1115 rtcount > icmp6_mtudisc_lowat) {
1116 /*
1117 * XXX nuke a victim, install the new one.
1118 */
1119 }
1120 } else {
1121 if (0 <= icmp6_mtudisc_lowat && rtcount > icmp6_mtudisc_lowat)
1122 return;
1123 }
1124
1125 bzero(&sin6, sizeof(sin6));
1126 sin6.sin6_family = PF_INET6;
1127 sin6.sin6_len = sizeof(struct sockaddr_in6);
1128 sin6.sin6_addr = *dst;
1129 /* XXX normally, this won't happen */
1130 if (IN6_IS_ADDR_LINKLOCAL(dst)) {
1131 sin6.sin6_addr.s6_addr16[1] =
1132 htons(m->m_pkthdr.rcvif->if_index);
1133 }
1134 /* sin6.sin6_scope_id = XXX: should be set if DST is a scoped addr */
1135 rt = icmp6_mtudisc_clone((struct sockaddr *)&sin6);
1136
1137 if (rt && (rt->rt_flags & RTF_HOST) &&
1138 !(rt->rt_rmx.rmx_locks & RTV_MTU) &&
1139 (rt->rt_rmx.rmx_mtu > mtu || rt->rt_rmx.rmx_mtu == 0)) {
1140 if (mtu < IN6_LINKMTU(rt->rt_ifp)) {
1141 icmp6stat.icp6s_pmtuchg++;
1142 rt->rt_rmx.rmx_mtu = mtu;
1143 }
1144 }
1145 if (rt) { /* XXX: need braces to avoid conflict with else in RTFREE. */
1146 RTFREE(rt);
1147 }
1148
1149 /*
1150 * Notify protocols that the MTU for this destination
1151 * has changed.
1152 */
1153 for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL;
1154 mc = LIST_NEXT(mc, mc_list))
1155 (*mc->mc_func)(&sin6.sin6_addr);
1156 }
1157
1158 /*
1159 * Process a Node Information Query packet, based on
1160 * draft-ietf-ipngwg-icmp-name-lookups-07.
1161 *
1162 * Spec incompatibilities:
1163 * - IPv6 Subject address handling
1164 * - IPv4 Subject address handling support missing
1165 * - Proxy reply (answer even if it's not for me)
1166 * - joins NI group address at in6_ifattach() time only, does not cope
1167 * with hostname changes by sethostname(3)
1168 */
1169 #ifndef offsetof /* XXX */
1170 #define offsetof(type, member) ((size_t)(&((type *)0)->member))
1171 #endif
1172 static struct mbuf *
ni6_input(m,off)1173 ni6_input(m, off)
1174 struct mbuf *m;
1175 int off;
1176 {
1177 struct icmp6_nodeinfo *ni6, *nni6;
1178 struct mbuf *n = NULL;
1179 u_int16_t qtype;
1180 int subjlen;
1181 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1182 struct ni_reply_fqdn *fqdn;
1183 int addrs; /* for NI_QTYPE_NODEADDR */
1184 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1185 struct sockaddr_in6 sin6; /* double meaning; ip6_dst and subjectaddr */
1186 struct ip6_hdr *ip6;
1187 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */
1188 char *subj = NULL;
1189
1190 ip6 = mtod(m, struct ip6_hdr *);
1191 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1192 if (ni6 == NULL) {
1193 /* m is already reclaimed */
1194 return NULL;
1195 }
1196
1197 /*
1198 * Validate IPv6 destination address.
1199 *
1200 * The Responder must discard the Query without further processing
1201 * unless it is one of the Responder's unicast or anycast addresses, or
1202 * a link-local scope multicast address which the Responder has joined.
1203 * [icmp-name-lookups-07, Section 4.]
1204 */
1205 bzero(&sin6, sizeof(sin6));
1206 sin6.sin6_family = AF_INET6;
1207 sin6.sin6_len = sizeof(struct sockaddr_in6);
1208 bcopy(&ip6->ip6_dst, &sin6.sin6_addr, sizeof(sin6.sin6_addr));
1209 /* XXX scopeid */
1210 if (ifa_ifwithaddr((struct sockaddr *)&sin6))
1211 ; /* unicast/anycast, fine */
1212 else if (IN6_IS_ADDR_MC_LINKLOCAL(&sin6.sin6_addr))
1213 ; /* link-local multicast, fine */
1214 else
1215 goto bad;
1216
1217 /* validate query Subject field. */
1218 qtype = ntohs(ni6->ni_qtype);
1219 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1220 switch (qtype) {
1221 case NI_QTYPE_NOOP:
1222 case NI_QTYPE_SUPTYPES:
1223 /* 07 draft */
1224 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1225 break;
1226 /* FALLTHROUGH */
1227 case NI_QTYPE_FQDN:
1228 case NI_QTYPE_NODEADDR:
1229 switch (ni6->ni_code) {
1230 case ICMP6_NI_SUBJ_IPV6:
1231 #if ICMP6_NI_SUBJ_IPV6 != 0
1232 case 0:
1233 #endif
1234 /*
1235 * backward compatibility - try to accept 03 draft
1236 * format, where no Subject is present.
1237 */
1238 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1239 subjlen == 0) {
1240 oldfqdn++;
1241 break;
1242 }
1243 #if ICMP6_NI_SUBJ_IPV6 != 0
1244 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1245 goto bad;
1246 #endif
1247
1248 if (subjlen != sizeof(sin6.sin6_addr))
1249 goto bad;
1250
1251 /*
1252 * Validate Subject address.
1253 *
1254 * Not sure what exactly "address belongs to the node"
1255 * means in the spec, is it just unicast, or what?
1256 *
1257 * At this moment we consider Subject address as
1258 * "belong to the node" if the Subject address equals
1259 * to the IPv6 destination address; validation for
1260 * IPv6 destination address should have done enough
1261 * check for us.
1262 *
1263 * We do not do proxy at this moment.
1264 */
1265 /* m_pulldown instead of copy? */
1266 m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1267 subjlen, (caddr_t)&sin6.sin6_addr);
1268 /* XXX kame scope hack */
1269 if (IN6_IS_SCOPE_LINKLOCAL(&sin6.sin6_addr)) {
1270 if ((m->m_flags & M_PKTHDR) != 0 &&
1271 m->m_pkthdr.rcvif) {
1272 sin6.sin6_addr.s6_addr16[1] =
1273 htons(m->m_pkthdr.rcvif->if_index);
1274 }
1275 }
1276 subj = (char *)&sin6;
1277 if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &sin6.sin6_addr))
1278 break;
1279
1280 /*
1281 * XXX if we are to allow other cases, we should really
1282 * be careful about scope here.
1283 * basically, we should disallow queries toward IPv6
1284 * destination X with subject Y, if scope(X) > scope(Y).
1285 * if we allow scope(X) > scope(Y), it will result in
1286 * information leakage across scope boundary.
1287 */
1288 goto bad;
1289
1290 case ICMP6_NI_SUBJ_FQDN:
1291 /*
1292 * Validate Subject name with gethostname(3).
1293 *
1294 * The behavior may need some debate, since:
1295 * - we are not sure if the node has FQDN as
1296 * hostname (returned by gethostname(3)).
1297 * - the code does wildcard match for truncated names.
1298 * however, we are not sure if we want to perform
1299 * wildcard match, if gethostname(3) side has
1300 * truncated hostname.
1301 */
1302 n = ni6_nametodns(hostname, hostnamelen, 0);
1303 if (!n || n->m_next || n->m_len == 0)
1304 goto bad;
1305 IP6_EXTHDR_GET(subj, char *, m,
1306 off + sizeof(struct icmp6_nodeinfo), subjlen);
1307 if (subj == NULL)
1308 goto bad;
1309 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1310 n->m_len)) {
1311 goto bad;
1312 }
1313 m_freem(n);
1314 n = NULL;
1315 break;
1316
1317 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */
1318 default:
1319 goto bad;
1320 }
1321 break;
1322 }
1323
1324 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */
1325 switch (qtype) {
1326 case NI_QTYPE_FQDN:
1327 if ((icmp6_nodeinfo & 1) == 0)
1328 goto bad;
1329 break;
1330 case NI_QTYPE_NODEADDR:
1331 if ((icmp6_nodeinfo & 2) == 0)
1332 goto bad;
1333 break;
1334 }
1335
1336 /* guess reply length */
1337 switch (qtype) {
1338 case NI_QTYPE_NOOP:
1339 break; /* no reply data */
1340 case NI_QTYPE_SUPTYPES:
1341 replylen += sizeof(u_int32_t);
1342 break;
1343 case NI_QTYPE_FQDN:
1344 /* XXX will append an mbuf */
1345 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1346 break;
1347 case NI_QTYPE_NODEADDR:
1348 addrs = ni6_addrs(ni6, m, &ifp, subj);
1349 if ((replylen += addrs * (sizeof(struct in6_addr) +
1350 sizeof(u_int32_t))) > MCLBYTES)
1351 replylen = MCLBYTES; /* XXX: will truncate pkt later */
1352 break;
1353 default:
1354 /*
1355 * XXX: We must return a reply with the ICMP6 code
1356 * `unknown Qtype' in this case. However we regard the case
1357 * as an FQDN query for backward compatibility.
1358 * Older versions set a random value to this field,
1359 * so it rarely varies in the defined qtypes.
1360 * But the mechanism is not reliable...
1361 * maybe we should obsolete older versions.
1362 */
1363 qtype = NI_QTYPE_FQDN;
1364 /* XXX will append an mbuf */
1365 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1366 oldfqdn++;
1367 break;
1368 }
1369
1370 /* allocate an mbuf to reply. */
1371 MGETHDR(n, M_DONTWAIT, m->m_type);
1372 if (n == NULL) {
1373 m_freem(m);
1374 return (NULL);
1375 }
1376 M_DUP_PKTHDR(n, m); /* just for rcvif */
1377 if (replylen > MHLEN) {
1378 if (replylen > MCLBYTES) {
1379 /*
1380 * XXX: should we try to allocate more? But MCLBYTES
1381 * is probably much larger than IPV6_MMTU...
1382 */
1383 goto bad;
1384 }
1385 MCLGET(n, M_DONTWAIT);
1386 if ((n->m_flags & M_EXT) == 0) {
1387 goto bad;
1388 }
1389 }
1390 n->m_pkthdr.len = n->m_len = replylen;
1391
1392 /* copy mbuf header and IPv6 + Node Information base headers */
1393 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1394 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1395 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1396
1397 /* qtype dependent procedure */
1398 switch (qtype) {
1399 case NI_QTYPE_NOOP:
1400 nni6->ni_code = ICMP6_NI_SUCCESS;
1401 nni6->ni_flags = 0;
1402 break;
1403 case NI_QTYPE_SUPTYPES:
1404 {
1405 u_int32_t v;
1406 nni6->ni_code = ICMP6_NI_SUCCESS;
1407 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1408 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1409 v = (u_int32_t)htonl(0x0000000f);
1410 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1411 break;
1412 }
1413 case NI_QTYPE_FQDN:
1414 nni6->ni_code = ICMP6_NI_SUCCESS;
1415 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1416 sizeof(struct ip6_hdr) +
1417 sizeof(struct icmp6_nodeinfo));
1418 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1419 fqdn->ni_fqdn_ttl = 0; /* ditto. */
1420 /*
1421 * XXX do we really have FQDN in variable "hostname"?
1422 */
1423 n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
1424 if (n->m_next == NULL)
1425 goto bad;
1426 /* XXX we assume that n->m_next is not a chain */
1427 if (n->m_next->m_next != NULL)
1428 goto bad;
1429 n->m_pkthdr.len += n->m_next->m_len;
1430 break;
1431 case NI_QTYPE_NODEADDR:
1432 {
1433 int lenlim, copied;
1434
1435 nni6->ni_code = ICMP6_NI_SUCCESS;
1436 n->m_pkthdr.len = n->m_len =
1437 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1438 lenlim = M_TRAILINGSPACE(n);
1439 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1440 /* XXX: reset mbuf length */
1441 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1442 sizeof(struct icmp6_nodeinfo) + copied;
1443 break;
1444 }
1445 default:
1446 break; /* XXX impossible! */
1447 }
1448
1449 nni6->ni_type = ICMP6_NI_REPLY;
1450 m_freem(m);
1451 return (n);
1452
1453 bad:
1454 m_freem(m);
1455 if (n)
1456 m_freem(n);
1457 return (NULL);
1458 }
1459 #undef hostnamelen
1460
1461 #define isupper(x) ('A' <= (x) && (x) <= 'Z')
1462 #define isalpha(x) (('A' <= (x) && (x) <= 'Z') || ('a' <= (x) && (x) <= 'z'))
1463 #define isalnum(x) (isalpha(x) || ('0' <= (x) && (x) <= '9'))
1464 #define tolower(x) (isupper(x) ? (x) + 'a' - 'A' : (x))
1465
1466 /*
1467 * make a mbuf with DNS-encoded string. no compression support.
1468 *
1469 * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1470 * treated as truncated name (two \0 at the end). this is a wild guess.
1471 */
1472 static struct mbuf *
ni6_nametodns(name,namelen,old)1473 ni6_nametodns(name, namelen, old)
1474 const char *name;
1475 int namelen;
1476 int old; /* return pascal string if non-zero */
1477 {
1478 struct mbuf *m;
1479 char *cp, *ep;
1480 const char *p, *q;
1481 int i, len, nterm;
1482
1483 if (old)
1484 len = namelen + 1;
1485 else
1486 len = MCLBYTES;
1487
1488 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1489 MGET(m, M_DONTWAIT, MT_DATA);
1490 if (m && len > MLEN) {
1491 MCLGET(m, M_DONTWAIT);
1492 if ((m->m_flags & M_EXT) == 0)
1493 goto fail;
1494 }
1495 if (!m)
1496 goto fail;
1497 m->m_next = NULL;
1498
1499 if (old) {
1500 m->m_len = len;
1501 *mtod(m, char *) = namelen;
1502 bcopy(name, mtod(m, char *) + 1, namelen);
1503 return m;
1504 } else {
1505 m->m_len = 0;
1506 cp = mtod(m, char *);
1507 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1508
1509 /* if not certain about my name, return empty buffer */
1510 if (namelen == 0)
1511 return m;
1512
1513 /*
1514 * guess if it looks like shortened hostname, or FQDN.
1515 * shortened hostname needs two trailing "\0".
1516 */
1517 i = 0;
1518 for (p = name; p < name + namelen; p++) {
1519 if (*p && *p == '.')
1520 i++;
1521 }
1522 if (i < 2)
1523 nterm = 2;
1524 else
1525 nterm = 1;
1526
1527 p = name;
1528 while (cp < ep && p < name + namelen) {
1529 i = 0;
1530 for (q = p; q < name + namelen && *q && *q != '.'; q++)
1531 i++;
1532 /* result does not fit into mbuf */
1533 if (cp + i + 1 >= ep)
1534 goto fail;
1535 /*
1536 * DNS label length restriction, RFC1035 page 8.
1537 * "i == 0" case is included here to avoid returning
1538 * 0-length label on "foo..bar".
1539 */
1540 if (i <= 0 || i >= 64)
1541 goto fail;
1542 *cp++ = i;
1543 if (!isalpha(p[0]) || !isalnum(p[i - 1]))
1544 goto fail;
1545 while (i > 0) {
1546 if (!isalnum(*p) && *p != '-')
1547 goto fail;
1548 if (isupper(*p)) {
1549 *cp++ = tolower(*p);
1550 p++;
1551 } else
1552 *cp++ = *p++;
1553 i--;
1554 }
1555 p = q;
1556 if (p < name + namelen && *p == '.')
1557 p++;
1558 }
1559 /* termination */
1560 if (cp + nterm >= ep)
1561 goto fail;
1562 while (nterm-- > 0)
1563 *cp++ = '\0';
1564 m->m_len = cp - mtod(m, char *);
1565 return m;
1566 }
1567
1568 panic("should not reach here");
1569 /* NOTREACHED */
1570
1571 fail:
1572 if (m)
1573 m_freem(m);
1574 return NULL;
1575 }
1576
1577 /*
1578 * check if two DNS-encoded string matches. takes care of truncated
1579 * form (with \0\0 at the end). no compression support.
1580 * XXX upper/lowercase match (see RFC2065)
1581 */
1582 static int
ni6_dnsmatch(a,alen,b,blen)1583 ni6_dnsmatch(a, alen, b, blen)
1584 const char *a;
1585 int alen;
1586 const char *b;
1587 int blen;
1588 {
1589 const char *a0, *b0;
1590 int l;
1591
1592 /* simplest case - need validation? */
1593 if (alen == blen && bcmp(a, b, alen) == 0)
1594 return 1;
1595
1596 a0 = a;
1597 b0 = b;
1598
1599 /* termination is mandatory */
1600 if (alen < 2 || blen < 2)
1601 return 0;
1602 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1603 return 0;
1604 alen--;
1605 blen--;
1606
1607 while (a - a0 < alen && b - b0 < blen) {
1608 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1609 return 0;
1610
1611 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1612 return 0;
1613 /* we don't support compression yet */
1614 if (a[0] >= 64 || b[0] >= 64)
1615 return 0;
1616
1617 /* truncated case */
1618 if (a[0] == 0 && a - a0 == alen - 1)
1619 return 1;
1620 if (b[0] == 0 && b - b0 == blen - 1)
1621 return 1;
1622 if (a[0] == 0 || b[0] == 0)
1623 return 0;
1624
1625 if (a[0] != b[0])
1626 return 0;
1627 l = a[0];
1628 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1629 return 0;
1630 if (bcmp(a + 1, b + 1, l) != 0)
1631 return 0;
1632
1633 a += 1 + l;
1634 b += 1 + l;
1635 }
1636
1637 if (a - a0 == alen && b - b0 == blen)
1638 return 1;
1639 else
1640 return 0;
1641 }
1642
1643 /*
1644 * calculate the number of addresses to be returned in the node info reply.
1645 */
1646 static int
ni6_addrs(ni6,m,ifpp,subj)1647 ni6_addrs(ni6, m, ifpp, subj)
1648 struct icmp6_nodeinfo *ni6;
1649 struct mbuf *m;
1650 struct ifnet **ifpp;
1651 char *subj;
1652 {
1653 struct ifnet *ifp;
1654 struct in6_ifaddr *ifa6;
1655 struct ifaddr *ifa;
1656 struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */
1657 int addrs = 0, addrsofif, iffound = 0;
1658 int niflags = ni6->ni_flags;
1659
1660 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1661 switch (ni6->ni_code) {
1662 case ICMP6_NI_SUBJ_IPV6:
1663 if (subj == NULL) /* must be impossible... */
1664 return (0);
1665 subj_ip6 = (struct sockaddr_in6 *)subj;
1666 break;
1667 default:
1668 /*
1669 * XXX: we only support IPv6 subject address for
1670 * this Qtype.
1671 */
1672 return (0);
1673 }
1674 }
1675
1676 for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
1677 {
1678 addrsofif = 0;
1679 for (ifa = ifp->if_addrlist.tqh_first; ifa;
1680 ifa = ifa->ifa_list.tqe_next)
1681 {
1682 if (ifa->ifa_addr->sa_family != AF_INET6)
1683 continue;
1684 ifa6 = (struct in6_ifaddr *)ifa;
1685
1686 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1687 IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr,
1688 &ifa6->ia_addr.sin6_addr))
1689 iffound = 1;
1690
1691 /*
1692 * IPv4-mapped addresses can only be returned by a
1693 * Node Information proxy, since they represent
1694 * addresses of IPv4-only nodes, which perforce do
1695 * not implement this protocol.
1696 * [icmp-name-lookups-07, Section 5.4]
1697 * So we don't support NI_NODEADDR_FLAG_COMPAT in
1698 * this function at this moment.
1699 */
1700
1701 /* What do we have to do about ::1? */
1702 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1703 case IPV6_ADDR_SCOPE_LINKLOCAL:
1704 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1705 continue;
1706 break;
1707 case IPV6_ADDR_SCOPE_SITELOCAL:
1708 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1709 continue;
1710 break;
1711 case IPV6_ADDR_SCOPE_GLOBAL:
1712 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1713 continue;
1714 break;
1715 default:
1716 continue;
1717 }
1718
1719 /*
1720 * check if anycast is okay.
1721 * XXX: just experimental. not in the spec.
1722 */
1723 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1724 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1725 continue; /* we need only unicast addresses */
1726
1727 addrsofif++; /* count the address */
1728 }
1729 if (iffound) {
1730 *ifpp = ifp;
1731 return (addrsofif);
1732 }
1733
1734 addrs += addrsofif;
1735 }
1736
1737 return (addrs);
1738 }
1739
1740 static int
ni6_store_addrs(ni6,nni6,ifp0,resid)1741 ni6_store_addrs(ni6, nni6, ifp0, resid)
1742 struct icmp6_nodeinfo *ni6, *nni6;
1743 struct ifnet *ifp0;
1744 int resid;
1745 {
1746 struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
1747 struct in6_ifaddr *ifa6;
1748 struct ifaddr *ifa;
1749 struct ifnet *ifp_dep = NULL;
1750 int copied = 0, allow_deprecated = 0;
1751 u_char *cp = (u_char *)(nni6 + 1);
1752 int niflags = ni6->ni_flags;
1753 u_int32_t ltime;
1754
1755 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1756 return (0); /* needless to copy */
1757
1758 again:
1759
1760 for (; ifp; ifp = TAILQ_NEXT(ifp, if_list))
1761 {
1762 for (ifa = ifp->if_addrlist.tqh_first; ifa;
1763 ifa = ifa->ifa_list.tqe_next)
1764 {
1765 if (ifa->ifa_addr->sa_family != AF_INET6)
1766 continue;
1767 ifa6 = (struct in6_ifaddr *)ifa;
1768
1769 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1770 allow_deprecated == 0) {
1771 /*
1772 * prefererred address should be put before
1773 * deprecated addresses.
1774 */
1775
1776 /* record the interface for later search */
1777 if (ifp_dep == NULL)
1778 ifp_dep = ifp;
1779
1780 continue;
1781 }
1782 else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1783 allow_deprecated != 0)
1784 continue; /* we now collect deprecated addrs */
1785
1786 /* What do we have to do about ::1? */
1787 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1788 case IPV6_ADDR_SCOPE_LINKLOCAL:
1789 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1790 continue;
1791 break;
1792 case IPV6_ADDR_SCOPE_SITELOCAL:
1793 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1794 continue;
1795 break;
1796 case IPV6_ADDR_SCOPE_GLOBAL:
1797 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1798 continue;
1799 break;
1800 default:
1801 continue;
1802 }
1803
1804 /*
1805 * check if anycast is okay.
1806 * XXX: just experimental. not in the spec.
1807 */
1808 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1809 (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1810 continue;
1811
1812 /* now we can copy the address */
1813 if (resid < sizeof(struct in6_addr) +
1814 sizeof(u_int32_t)) {
1815 /*
1816 * We give up much more copy.
1817 * Set the truncate flag and return.
1818 */
1819 nni6->ni_flags |=
1820 NI_NODEADDR_FLAG_TRUNCATE;
1821 return (copied);
1822 }
1823
1824 /*
1825 * Set the TTL of the address.
1826 * The TTL value should be one of the following
1827 * according to the specification:
1828 *
1829 * 1. The remaining lifetime of a DHCP lease on the
1830 * address, or
1831 * 2. The remaining Valid Lifetime of a prefix from
1832 * which the address was derived through Stateless
1833 * Autoconfiguration.
1834 *
1835 * Note that we currently do not support stateful
1836 * address configuration by DHCPv6, so the former
1837 * case can't happen.
1838 *
1839 * TTL must be 2^31 > TTL >= 0.
1840 */
1841 if (ifa6->ia6_lifetime.ia6t_expire == 0)
1842 ltime = ND6_INFINITE_LIFETIME;
1843 else {
1844 if (ifa6->ia6_lifetime.ia6t_expire >
1845 time.tv_sec)
1846 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time.tv_sec);
1847 else
1848 ltime = 0;
1849 }
1850
1851 bcopy(<ime, cp, sizeof(u_int32_t));
1852 cp += sizeof(u_int32_t);
1853
1854 /* copy the address itself */
1855 bcopy(&ifa6->ia_addr.sin6_addr, cp,
1856 sizeof(struct in6_addr));
1857 /* XXX: KAME link-local hack; remove ifindex */
1858 if (IN6_IS_ADDR_LINKLOCAL(&ifa6->ia_addr.sin6_addr))
1859 ((struct in6_addr *)cp)->s6_addr16[1] = 0;
1860 cp += sizeof(struct in6_addr);
1861
1862 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1863 copied += (sizeof(struct in6_addr) +
1864 sizeof(u_int32_t));
1865 }
1866 if (ifp0) /* we need search only on the specified IF */
1867 break;
1868 }
1869
1870 if (allow_deprecated == 0 && ifp_dep != NULL) {
1871 ifp = ifp_dep;
1872 allow_deprecated = 1;
1873
1874 goto again;
1875 }
1876
1877 return (copied);
1878 }
1879
1880 /*
1881 * XXX almost dup'ed code with rip6_input.
1882 */
1883 static int
icmp6_rip6_input(mp,off)1884 icmp6_rip6_input(mp, off)
1885 struct mbuf **mp;
1886 int off;
1887 {
1888 struct mbuf *m = *mp;
1889 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1890 struct in6pcb *in6p;
1891 struct in6pcb *last = NULL;
1892 struct sockaddr_in6 rip6src;
1893 struct icmp6_hdr *icmp6;
1894 struct mbuf *opts = NULL;
1895
1896 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1897 if (icmp6 == NULL) {
1898 /* m is already reclaimed */
1899 return IPPROTO_DONE;
1900 }
1901
1902 bzero(&rip6src, sizeof(rip6src));
1903 rip6src.sin6_len = sizeof(struct sockaddr_in6);
1904 rip6src.sin6_family = AF_INET6;
1905 /* KAME hack: recover scopeid */
1906 (void)in6_recoverscope(&rip6src, &ip6->ip6_src, m->m_pkthdr.rcvif);
1907
1908 CIRCLEQ_FOREACH(in6p, &rawin6pcbtable.inpt_queue, inp_queue) {
1909 if (!(in6p->in6p_flags & INP_IPV6))
1910 continue;
1911 if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6)
1912 continue;
1913 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1914 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1915 continue;
1916 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1917 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1918 continue;
1919 if (in6p->in6p_icmp6filt
1920 && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1921 in6p->in6p_icmp6filt))
1922 continue;
1923 if (last) {
1924 struct mbuf *n;
1925 if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1926 if (last->in6p_flags & IN6P_CONTROLOPTS)
1927 ip6_savecontrol(last, &opts, ip6, n);
1928 /* strip intermediate headers */
1929 m_adj(n, off);
1930 if (sbappendaddr(&last->in6p_socket->so_rcv,
1931 (struct sockaddr *)&rip6src,
1932 n, opts) == 0) {
1933 /* should notify about lost packet */
1934 m_freem(n);
1935 if (opts)
1936 m_freem(opts);
1937 } else
1938 sorwakeup(last->in6p_socket);
1939 opts = NULL;
1940 }
1941 }
1942 last = in6p;
1943 }
1944 if (last) {
1945 if (last->in6p_flags & IN6P_CONTROLOPTS)
1946 ip6_savecontrol(last, &opts, ip6, m);
1947 /* strip intermediate headers */
1948 m_adj(m, off);
1949 if (sbappendaddr(&last->in6p_socket->so_rcv,
1950 (struct sockaddr *)&rip6src,
1951 m, opts) == 0) {
1952 m_freem(m);
1953 if (opts)
1954 m_freem(opts);
1955 } else
1956 sorwakeup(last->in6p_socket);
1957 } else {
1958 m_freem(m);
1959 ip6stat.ip6s_delivered--;
1960 }
1961 return IPPROTO_DONE;
1962 }
1963
1964 /*
1965 * Reflect the ip6 packet back to the source.
1966 * OFF points to the icmp6 header, counted from the top of the mbuf.
1967 *
1968 * Note: RFC 1885 required that an echo reply should be truncated if it
1969 * did not fit in with (return) path MTU, and KAME code supported the
1970 * behavior. However, as a clarification after the RFC, this limitation
1971 * was removed in a revised version of the spec, RFC 2463. We had kept the
1972 * old behavior, with a (non-default) ifdef block, while the new version of
1973 * the spec was an internet-draft status, and even after the new RFC was
1974 * published. But it would rather make sense to clean the obsoleted part
1975 * up, and to make the code simpler at this stage.
1976 */
1977 void
icmp6_reflect(m,off)1978 icmp6_reflect(m, off)
1979 struct mbuf *m;
1980 size_t off;
1981 {
1982 struct ip6_hdr *ip6;
1983 struct icmp6_hdr *icmp6;
1984 struct in6_ifaddr *ia;
1985 struct in6_addr t, *src = 0;
1986 int plen;
1987 int type, code;
1988 struct ifnet *outif = NULL;
1989 struct sockaddr_in6 sa6_src, sa6_dst;
1990
1991 /* too short to reflect */
1992 if (off < sizeof(struct ip6_hdr)) {
1993 nd6log((LOG_DEBUG,
1994 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
1995 (u_long)off, (u_long)sizeof(struct ip6_hdr),
1996 __FILE__, __LINE__));
1997 goto bad;
1998 }
1999
2000 /*
2001 * If there are extra headers between IPv6 and ICMPv6, strip
2002 * off that header first.
2003 */
2004 #ifdef DIAGNOSTIC
2005 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2006 panic("assumption failed in icmp6_reflect");
2007 #endif
2008 if (off > sizeof(struct ip6_hdr)) {
2009 size_t l;
2010 struct ip6_hdr nip6;
2011
2012 l = off - sizeof(struct ip6_hdr);
2013 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2014 m_adj(m, l);
2015 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2016 if (m->m_len < l) {
2017 if ((m = m_pullup(m, l)) == NULL)
2018 return;
2019 }
2020 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2021 } else /* off == sizeof(struct ip6_hdr) */ {
2022 size_t l;
2023 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2024 if (m->m_len < l) {
2025 if ((m = m_pullup(m, l)) == NULL)
2026 return;
2027 }
2028 }
2029 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2030 ip6 = mtod(m, struct ip6_hdr *);
2031 ip6->ip6_nxt = IPPROTO_ICMPV6;
2032 icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2033 type = icmp6->icmp6_type; /* keep type for statistics */
2034 code = icmp6->icmp6_code; /* ditto. */
2035
2036 t = ip6->ip6_dst;
2037 /*
2038 * ip6_input() drops a packet if its src is multicast.
2039 * So, the src is never multicast.
2040 */
2041 ip6->ip6_dst = ip6->ip6_src;
2042
2043 /*
2044 * XXX: make sure to embed scope zone information, using
2045 * already embedded IDs or the received interface (if any).
2046 * Note that rcvif may be NULL.
2047 * TODO: scoped routing case (XXX).
2048 */
2049 bzero(&sa6_src, sizeof(sa6_src));
2050 sa6_src.sin6_family = AF_INET6;
2051 sa6_src.sin6_len = sizeof(sa6_src);
2052 sa6_src.sin6_addr = ip6->ip6_dst;
2053 in6_recoverscope(&sa6_src, &ip6->ip6_dst, m->m_pkthdr.rcvif);
2054 in6_embedscope(&ip6->ip6_dst, &sa6_src, NULL, NULL);
2055 bzero(&sa6_dst, sizeof(sa6_dst));
2056 sa6_dst.sin6_family = AF_INET6;
2057 sa6_dst.sin6_len = sizeof(sa6_dst);
2058 sa6_dst.sin6_addr = t;
2059 in6_recoverscope(&sa6_dst, &t, m->m_pkthdr.rcvif);
2060 in6_embedscope(&t, &sa6_dst, NULL, NULL);
2061
2062 /*
2063 * If the incoming packet was addressed directly to us (i.e. unicast),
2064 * use dst as the src for the reply.
2065 * The IN6_IFF_NOTREADY case would be VERY rare, but is possible
2066 * (for example) when we encounter an error while forwarding procedure
2067 * destined to a duplicated address of ours.
2068 */
2069 for (ia = in6_ifaddr; ia; ia = ia->ia_next)
2070 if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) &&
2071 (ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) {
2072 src = &t;
2073 break;
2074 }
2075 if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) && (m->m_flags & M_LOOP)) {
2076 /*
2077 * This is the case if the dst is our link-local address
2078 * and the sender is also ourselves.
2079 */
2080 src = &t;
2081 }
2082
2083 if (src == 0) {
2084 int e;
2085 struct route_in6 ro;
2086
2087 /*
2088 * This case matches to multicasts, our anycast, or unicasts
2089 * that we do not own. Select a source address based on the
2090 * source address of the erroneous packet.
2091 */
2092 bzero(&ro, sizeof(ro));
2093 src = in6_selectsrc(&sa6_src, NULL, NULL, &ro, NULL, &e);
2094 if (ro.ro_rt) { /* XXX: see comments in icmp6_mtudisc_update */
2095 RTFREE(ro.ro_rt); /* XXX: we could use this */
2096 }
2097 if (src == NULL) {
2098 nd6log((LOG_DEBUG,
2099 "icmp6_reflect: source can't be determined: "
2100 "dst=%s, error=%d\n",
2101 ip6_sprintf(&sa6_src.sin6_addr), e));
2102 goto bad;
2103 }
2104 }
2105
2106 ip6->ip6_src = *src;
2107
2108 ip6->ip6_flow = 0;
2109 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2110 ip6->ip6_vfc |= IPV6_VERSION;
2111 ip6->ip6_nxt = IPPROTO_ICMPV6;
2112 if (m->m_pkthdr.rcvif) {
2113 /* XXX: This may not be the outgoing interface */
2114 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2115 } else
2116 ip6->ip6_hlim = ip6_defhlim;
2117
2118 icmp6->icmp6_cksum = 0;
2119 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2120 sizeof(struct ip6_hdr), plen);
2121
2122 /*
2123 * XXX option handling
2124 */
2125
2126 m->m_flags &= ~(M_BCAST|M_MCAST);
2127
2128 /*
2129 * To avoid a "too big" situation at an intermediate router
2130 * and the path MTU discovery process, specify the IPV6_MINMTU flag.
2131 * Note that only echo and node information replies are affected,
2132 * since the length of ICMP6 errors is limited to the minimum MTU.
2133 */
2134 if (ip6_output(m, NULL, NULL, IPV6_MINMTU, NULL, &outif) != 0 && outif)
2135 icmp6_ifstat_inc(outif, ifs6_out_error);
2136
2137 if (outif)
2138 icmp6_ifoutstat_inc(outif, type, code);
2139
2140 return;
2141
2142 bad:
2143 m_freem(m);
2144 return;
2145 }
2146
2147 void
icmp6_fasttimo()2148 icmp6_fasttimo()
2149 {
2150
2151 mld6_fasttimeo();
2152 }
2153
2154 static const char *
icmp6_redirect_diag(src6,dst6,tgt6)2155 icmp6_redirect_diag(src6, dst6, tgt6)
2156 struct in6_addr *src6;
2157 struct in6_addr *dst6;
2158 struct in6_addr *tgt6;
2159 {
2160 static char buf[1024];
2161 snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2162 ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6));
2163 return buf;
2164 }
2165
2166 void
icmp6_redirect_input(m,off)2167 icmp6_redirect_input(m, off)
2168 struct mbuf *m;
2169 int off;
2170 {
2171 struct ifnet *ifp = m->m_pkthdr.rcvif;
2172 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2173 struct nd_redirect *nd_rd;
2174 int icmp6len = ntohs(ip6->ip6_plen);
2175 char *lladdr = NULL;
2176 int lladdrlen = 0;
2177 u_char *redirhdr = NULL;
2178 int redirhdrlen = 0;
2179 struct rtentry *rt = NULL;
2180 int is_router;
2181 int is_onlink;
2182 struct in6_addr src6 = ip6->ip6_src;
2183 struct in6_addr redtgt6;
2184 struct in6_addr reddst6;
2185 union nd_opts ndopts;
2186
2187 if (!ifp)
2188 return;
2189
2190 /* XXX if we are router, we don't update route by icmp6 redirect */
2191 if (ip6_forwarding)
2192 goto freeit;
2193 if (!icmp6_rediraccept)
2194 goto freeit;
2195
2196 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2197 if (nd_rd == NULL) {
2198 icmp6stat.icp6s_tooshort++;
2199 return;
2200 }
2201 redtgt6 = nd_rd->nd_rd_target;
2202 reddst6 = nd_rd->nd_rd_dst;
2203
2204 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2205 redtgt6.s6_addr16[1] = htons(ifp->if_index);
2206 if (IN6_IS_ADDR_LINKLOCAL(&reddst6))
2207 reddst6.s6_addr16[1] = htons(ifp->if_index);
2208
2209 /* validation */
2210 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2211 nd6log((LOG_ERR,
2212 "ICMP6 redirect sent from %s rejected; "
2213 "must be from linklocal\n", ip6_sprintf(&src6)));
2214 goto bad;
2215 }
2216 if (ip6->ip6_hlim != 255) {
2217 nd6log((LOG_ERR,
2218 "ICMP6 redirect sent from %s rejected; "
2219 "hlim=%d (must be 255)\n",
2220 ip6_sprintf(&src6), ip6->ip6_hlim));
2221 goto bad;
2222 }
2223 {
2224 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2225 struct sockaddr_in6 sin6;
2226 struct in6_addr *gw6;
2227
2228 bzero(&sin6, sizeof(sin6));
2229 sin6.sin6_family = AF_INET6;
2230 sin6.sin6_len = sizeof(struct sockaddr_in6);
2231 bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2232 rt = rtalloc1((struct sockaddr *)&sin6, 0);
2233 if (rt) {
2234 if (rt->rt_gateway == NULL ||
2235 rt->rt_gateway->sa_family != AF_INET6) {
2236 nd6log((LOG_ERR,
2237 "ICMP6 redirect rejected; no route "
2238 "with inet6 gateway found for redirect dst: %s\n",
2239 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2240 RTFREE(rt);
2241 goto bad;
2242 }
2243
2244 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2245 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2246 nd6log((LOG_ERR,
2247 "ICMP6 redirect rejected; "
2248 "not equal to gw-for-src=%s (must be same): "
2249 "%s\n",
2250 ip6_sprintf(gw6),
2251 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2252 RTFREE(rt);
2253 goto bad;
2254 }
2255 } else {
2256 nd6log((LOG_ERR,
2257 "ICMP6 redirect rejected; "
2258 "no route found for redirect dst: %s\n",
2259 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2260 goto bad;
2261 }
2262 RTFREE(rt);
2263 rt = NULL;
2264 }
2265 if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2266 nd6log((LOG_ERR,
2267 "ICMP6 redirect rejected; "
2268 "redirect dst must be unicast: %s\n",
2269 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2270 goto bad;
2271 }
2272
2273 is_router = is_onlink = 0;
2274 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2275 is_router = 1; /* router case */
2276 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2277 is_onlink = 1; /* on-link destination case */
2278 if (!is_router && !is_onlink) {
2279 nd6log((LOG_ERR,
2280 "ICMP6 redirect rejected; "
2281 "neither router case nor onlink case: %s\n",
2282 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2283 goto bad;
2284 }
2285 /* validation passed */
2286
2287 icmp6len -= sizeof(*nd_rd);
2288 nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2289 if (nd6_options(&ndopts) < 0) {
2290 nd6log((LOG_INFO, "icmp6_redirect_input: "
2291 "invalid ND option, rejected: %s\n",
2292 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2293 /* nd6_options have incremented stats */
2294 goto freeit;
2295 }
2296
2297 if (ndopts.nd_opts_tgt_lladdr) {
2298 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2299 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2300 }
2301
2302 if (ndopts.nd_opts_rh) {
2303 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2304 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2305 }
2306
2307 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2308 nd6log((LOG_INFO,
2309 "icmp6_redirect_input: lladdrlen mismatch for %s "
2310 "(if %d, icmp6 packet %d): %s\n",
2311 ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2,
2312 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2313 goto bad;
2314 }
2315
2316 /* RFC 2461 8.3 */
2317 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2318 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2319
2320 if (!is_onlink) { /* better router case. perform rtredirect. */
2321 /* perform rtredirect */
2322 struct sockaddr_in6 sdst;
2323 struct sockaddr_in6 sgw;
2324 struct sockaddr_in6 ssrc;
2325 unsigned long rtcount;
2326 struct rtentry *newrt = NULL;
2327
2328 /*
2329 * do not install redirect route, if the number of entries
2330 * is too much (> hiwat). note that, the node (= host) will
2331 * work just fine even if we do not install redirect route
2332 * (there will be additional hops, though).
2333 */
2334 rtcount = rt_timer_count(icmp6_redirect_timeout_q);
2335 if (0 <= icmp6_redirect_hiwat && rtcount > icmp6_redirect_hiwat)
2336 return;
2337 else if (0 <= icmp6_redirect_lowat &&
2338 rtcount > icmp6_redirect_lowat) {
2339 /*
2340 * XXX nuke a victim, install the new one.
2341 */
2342 }
2343
2344 bzero(&sdst, sizeof(sdst));
2345 bzero(&sgw, sizeof(sgw));
2346 bzero(&ssrc, sizeof(ssrc));
2347 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2348 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2349 sizeof(struct sockaddr_in6);
2350 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2351 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2352 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2353 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2354 (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2355 (struct sockaddr *)&ssrc,
2356 &newrt);
2357
2358 if (newrt) {
2359 (void)rt_timer_add(newrt, icmp6_redirect_timeout,
2360 icmp6_redirect_timeout_q);
2361 rtfree(newrt);
2362 }
2363 }
2364 /* finally update cached route in each socket via pfctlinput */
2365 {
2366 struct sockaddr_in6 sdst;
2367
2368 bzero(&sdst, sizeof(sdst));
2369 sdst.sin6_family = AF_INET6;
2370 sdst.sin6_len = sizeof(struct sockaddr_in6);
2371 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2372 pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2373 }
2374
2375 freeit:
2376 m_freem(m);
2377 return;
2378
2379 bad:
2380 icmp6stat.icp6s_badredirect++;
2381 m_freem(m);
2382 }
2383
2384 void
icmp6_redirect_output(m0,rt)2385 icmp6_redirect_output(m0, rt)
2386 struct mbuf *m0;
2387 struct rtentry *rt;
2388 {
2389 struct ifnet *ifp; /* my outgoing interface */
2390 struct in6_addr *ifp_ll6;
2391 struct in6_addr *nexthop;
2392 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */
2393 struct mbuf *m = NULL; /* newly allocated one */
2394 struct ip6_hdr *ip6; /* m as struct ip6_hdr */
2395 struct nd_redirect *nd_rd;
2396 size_t maxlen;
2397 u_char *p;
2398 struct sockaddr_in6 src_sa;
2399
2400 icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2401
2402 /* if we are not router, we don't send icmp6 redirect */
2403 if (!ip6_forwarding)
2404 goto fail;
2405
2406 /* sanity check */
2407 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2408 goto fail;
2409
2410 /*
2411 * Address check:
2412 * the source address must identify a neighbor, and
2413 * the destination address must not be a multicast address
2414 * [RFC 2461, sec 8.2]
2415 */
2416 sip6 = mtod(m0, struct ip6_hdr *);
2417 bzero(&src_sa, sizeof(src_sa));
2418 src_sa.sin6_family = AF_INET6;
2419 src_sa.sin6_len = sizeof(src_sa);
2420 src_sa.sin6_addr = sip6->ip6_src;
2421 /* we don't currently use sin6_scope_id, but eventually use it */
2422 src_sa.sin6_scope_id = in6_addr2scopeid(ifp, &sip6->ip6_src);
2423 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2424 goto fail;
2425 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2426 goto fail; /* what should we do here? */
2427
2428 /* rate limit */
2429 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2430 goto fail;
2431
2432 /*
2433 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2434 * we almost always ask for an mbuf cluster for simplicity.
2435 * (MHLEN < IPV6_MMTU is almost always true)
2436 */
2437 #if IPV6_MMTU >= MCLBYTES
2438 # error assumption failed about IPV6_MMTU and MCLBYTES
2439 #endif
2440 MGETHDR(m, M_DONTWAIT, MT_HEADER);
2441 if (m && IPV6_MMTU >= MHLEN)
2442 MCLGET(m, M_DONTWAIT);
2443 if (!m)
2444 goto fail;
2445 m->m_pkthdr.rcvif = NULL;
2446 m->m_len = 0;
2447 maxlen = M_TRAILINGSPACE(m);
2448 maxlen = min(IPV6_MMTU, maxlen);
2449 /* just for safety */
2450 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2451 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2452 goto fail;
2453 }
2454
2455 {
2456 /* get ip6 linklocal address for ifp(my outgoing interface). */
2457 struct in6_ifaddr *ia;
2458 if ((ia = in6ifa_ifpforlinklocal(ifp,
2459 IN6_IFF_NOTREADY|
2460 IN6_IFF_ANYCAST)) == NULL)
2461 goto fail;
2462 ifp_ll6 = &ia->ia_addr.sin6_addr;
2463 }
2464
2465 /* get ip6 linklocal address for the router. */
2466 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2467 struct sockaddr_in6 *sin6;
2468 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2469 nexthop = &sin6->sin6_addr;
2470 if (!IN6_IS_ADDR_LINKLOCAL(nexthop))
2471 nexthop = NULL;
2472 } else
2473 nexthop = NULL;
2474
2475 /* ip6 */
2476 ip6 = mtod(m, struct ip6_hdr *);
2477 ip6->ip6_flow = 0;
2478 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2479 ip6->ip6_vfc |= IPV6_VERSION;
2480 /* ip6->ip6_plen will be set later */
2481 ip6->ip6_nxt = IPPROTO_ICMPV6;
2482 ip6->ip6_hlim = 255;
2483 /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2484 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2485 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2486
2487 /* ND Redirect */
2488 nd_rd = (struct nd_redirect *)(ip6 + 1);
2489 nd_rd->nd_rd_type = ND_REDIRECT;
2490 nd_rd->nd_rd_code = 0;
2491 nd_rd->nd_rd_reserved = 0;
2492 if (rt->rt_flags & RTF_GATEWAY) {
2493 /*
2494 * nd_rd->nd_rd_target must be a link-local address in
2495 * better router cases.
2496 */
2497 if (!nexthop)
2498 goto fail;
2499 bcopy(nexthop, &nd_rd->nd_rd_target,
2500 sizeof(nd_rd->nd_rd_target));
2501 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2502 sizeof(nd_rd->nd_rd_dst));
2503 } else {
2504 /* make sure redtgt == reddst */
2505 nexthop = &sip6->ip6_dst;
2506 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2507 sizeof(nd_rd->nd_rd_target));
2508 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2509 sizeof(nd_rd->nd_rd_dst));
2510 }
2511
2512 p = (u_char *)(nd_rd + 1);
2513
2514 {
2515 /* target lladdr option */
2516 struct rtentry *rt_nexthop = NULL;
2517 int len;
2518 struct sockaddr_dl *sdl;
2519 struct nd_opt_hdr *nd_opt;
2520 char *lladdr;
2521
2522 rt_nexthop = nd6_lookup(nexthop, 0, ifp);
2523 if (!rt_nexthop)
2524 goto nolladdropt;
2525 len = sizeof(*nd_opt) + ifp->if_addrlen;
2526 len = (len + 7) & ~7; /* round by 8 */
2527 /* safety check */
2528 if (len + (p - (u_char *)ip6) > maxlen)
2529 goto nolladdropt;
2530 if (!(rt_nexthop->rt_flags & RTF_GATEWAY) &&
2531 (rt_nexthop->rt_flags & RTF_LLINFO) &&
2532 (rt_nexthop->rt_gateway->sa_family == AF_LINK) &&
2533 (sdl = (struct sockaddr_dl *)rt_nexthop->rt_gateway) &&
2534 sdl->sdl_alen) {
2535 nd_opt = (struct nd_opt_hdr *)p;
2536 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2537 nd_opt->nd_opt_len = len >> 3;
2538 lladdr = (char *)(nd_opt + 1);
2539 bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
2540 p += len;
2541 }
2542 }
2543 nolladdropt:;
2544
2545 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2546
2547 /* just to be safe */
2548 if (p - (u_char *)ip6 > maxlen)
2549 goto noredhdropt;
2550
2551 {
2552 /* redirected header option */
2553 int len;
2554 struct nd_opt_rd_hdr *nd_opt_rh;
2555
2556 /*
2557 * compute the maximum size for icmp6 redirect header option.
2558 * XXX room for auth header?
2559 */
2560 len = maxlen - (p - (u_char *)ip6);
2561 len &= ~7;
2562
2563 /*
2564 * Redirected header option spec (RFC2461 4.6.3) talks nothing
2565 * about padding/truncate rule for the original IP packet.
2566 * From the discussion on IPv6imp in Feb 1999,
2567 * the consensus was:
2568 * - "attach as much as possible" is the goal
2569 * - pad if not aligned (original size can be guessed by
2570 * original ip6 header)
2571 * Following code adds the padding if it is simple enough,
2572 * and truncates if not.
2573 */
2574 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2575 /* not enough room, truncate */
2576 m_adj(m0, (len - sizeof(*nd_opt_rh)) -
2577 m0->m_pkthdr.len);
2578 } else {
2579 /*
2580 * enough room, truncate if not aligned.
2581 * we don't pad here for simplicity.
2582 */
2583 size_t extra;
2584
2585 extra = m0->m_pkthdr.len % 8;
2586 if (extra) {
2587 /* truncate */
2588 m_adj(m0, -extra);
2589 }
2590 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2591 }
2592
2593 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2594 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2595 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2596 nd_opt_rh->nd_opt_rh_len = len >> 3;
2597 p += sizeof(*nd_opt_rh);
2598 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2599
2600 /* connect m0 to m */
2601 m->m_pkthdr.len += m0->m_pkthdr.len;
2602 m_cat(m, m0);
2603 m0 = NULL;
2604 }
2605 noredhdropt:
2606 if (m0) {
2607 m_freem(m0);
2608 m0 = NULL;
2609 }
2610
2611 if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_src))
2612 sip6->ip6_src.s6_addr16[1] = 0;
2613 if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_dst))
2614 sip6->ip6_dst.s6_addr16[1] = 0;
2615 #if 0
2616 if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
2617 ip6->ip6_src.s6_addr16[1] = 0;
2618 if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
2619 ip6->ip6_dst.s6_addr16[1] = 0;
2620 #endif
2621 if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_target))
2622 nd_rd->nd_rd_target.s6_addr16[1] = 0;
2623 if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_dst))
2624 nd_rd->nd_rd_dst.s6_addr16[1] = 0;
2625
2626 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2627
2628 nd_rd->nd_rd_cksum = 0;
2629 nd_rd->nd_rd_cksum
2630 = in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen));
2631
2632 /* send the packet to outside... */
2633 if (ip6_output(m, NULL, NULL, 0, NULL, NULL) != 0)
2634 icmp6_ifstat_inc(ifp, ifs6_out_error);
2635
2636 icmp6_ifstat_inc(ifp, ifs6_out_msg);
2637 icmp6_ifstat_inc(ifp, ifs6_out_redirect);
2638 icmp6stat.icp6s_outhist[ND_REDIRECT]++;
2639
2640 return;
2641
2642 fail:
2643 if (m)
2644 m_freem(m);
2645 if (m0)
2646 m_freem(m0);
2647 }
2648
2649 /* NRL PCB */
2650 #define sotoin6pcb sotoinpcb
2651 #define in6pcb inpcb
2652 #define in6p_icmp6filt inp_icmp6filt
2653
2654 /*
2655 * ICMPv6 socket option processing.
2656 */
2657 int
icmp6_ctloutput(op,so,level,optname,mp)2658 icmp6_ctloutput(op, so, level, optname, mp)
2659 int op;
2660 struct socket *so;
2661 int level, optname;
2662 struct mbuf **mp;
2663 {
2664 int error = 0;
2665 int optlen;
2666 struct in6pcb *in6p = sotoin6pcb(so);
2667 struct mbuf *m = *mp;
2668
2669 optlen = m ? m->m_len : 0;
2670
2671 if (level != IPPROTO_ICMPV6) {
2672 if (op == PRCO_SETOPT && m)
2673 (void)m_free(m);
2674 return EINVAL;
2675 }
2676
2677 switch (op) {
2678 case PRCO_SETOPT:
2679 switch (optname) {
2680 case ICMP6_FILTER:
2681 {
2682 struct icmp6_filter *p;
2683
2684 if (optlen != sizeof(*p)) {
2685 error = EMSGSIZE;
2686 break;
2687 }
2688 p = mtod(m, struct icmp6_filter *);
2689 if (!p || !in6p->in6p_icmp6filt) {
2690 error = EINVAL;
2691 break;
2692 }
2693 bcopy(p, in6p->in6p_icmp6filt,
2694 sizeof(struct icmp6_filter));
2695 error = 0;
2696 break;
2697 }
2698
2699 default:
2700 error = ENOPROTOOPT;
2701 break;
2702 }
2703 if (m)
2704 (void)m_freem(m);
2705 break;
2706
2707 case PRCO_GETOPT:
2708 switch (optname) {
2709 case ICMP6_FILTER:
2710 {
2711 struct icmp6_filter *p;
2712
2713 if (!in6p->in6p_icmp6filt) {
2714 error = EINVAL;
2715 break;
2716 }
2717 *mp = m = m_get(M_WAIT, MT_SOOPTS);
2718 m->m_len = sizeof(struct icmp6_filter);
2719 p = mtod(m, struct icmp6_filter *);
2720 bcopy(in6p->in6p_icmp6filt, p,
2721 sizeof(struct icmp6_filter));
2722 error = 0;
2723 break;
2724 }
2725
2726 default:
2727 error = ENOPROTOOPT;
2728 break;
2729 }
2730 break;
2731 }
2732
2733 return (error);
2734 }
2735
2736 /* NRL PCB */
2737 #undef sotoin6pcb
2738 #undef in6pcb
2739 #undef in6p_icmp6filt
2740
2741 /*
2742 * Perform rate limit check.
2743 * Returns 0 if it is okay to send the icmp6 packet.
2744 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2745 * limitation.
2746 *
2747 * XXX per-destination/type check necessary?
2748 */
2749 static int
icmp6_ratelimit(dst,type,code)2750 icmp6_ratelimit(dst, type, code)
2751 const struct in6_addr *dst; /* not used at this moment */
2752 const int type; /* not used at this moment */
2753 const int code; /* not used at this moment */
2754 {
2755 int ret;
2756
2757 ret = 0; /* okay to send */
2758
2759 /* PPS limit */
2760 if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
2761 icmp6errppslim)) {
2762 /* The packet is subject to rate limit */
2763 ret++;
2764 }
2765
2766 return ret;
2767 }
2768
2769 static struct rtentry *
icmp6_mtudisc_clone(dst)2770 icmp6_mtudisc_clone(dst)
2771 struct sockaddr *dst;
2772 {
2773 struct rtentry *rt;
2774 int error;
2775
2776 rt = rtalloc1(dst, 1);
2777 if (rt == 0)
2778 return NULL;
2779
2780 /* If we didn't get a host route, allocate one */
2781 if ((rt->rt_flags & RTF_HOST) == 0) {
2782 struct rtentry *nrt;
2783
2784 error = rtrequest((int) RTM_ADD, dst,
2785 (struct sockaddr *) rt->rt_gateway,
2786 (struct sockaddr *) 0,
2787 RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt);
2788 if (error) {
2789 rtfree(rt);
2790 return NULL;
2791 }
2792 nrt->rt_rmx = rt->rt_rmx;
2793 rtfree(rt);
2794 rt = nrt;
2795 }
2796 error = rt_timer_add(rt, icmp6_mtudisc_timeout,
2797 icmp6_mtudisc_timeout_q);
2798 if (error) {
2799 rtfree(rt);
2800 return NULL;
2801 }
2802
2803 return rt; /* caller need to call rtfree() */
2804 }
2805
2806 static void
icmp6_mtudisc_timeout(rt,r)2807 icmp6_mtudisc_timeout(rt, r)
2808 struct rtentry *rt;
2809 struct rttimer *r;
2810 {
2811 if (rt == NULL)
2812 panic("icmp6_mtudisc_timeout: bad route to timeout");
2813 if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) ==
2814 (RTF_DYNAMIC | RTF_HOST)) {
2815 rtrequest((int) RTM_DELETE, (struct sockaddr *)rt_key(rt),
2816 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
2817 } else {
2818 if (!(rt->rt_rmx.rmx_locks & RTV_MTU))
2819 rt->rt_rmx.rmx_mtu = 0;
2820 }
2821 }
2822
2823 static void
icmp6_redirect_timeout(rt,r)2824 icmp6_redirect_timeout(rt, r)
2825 struct rtentry *rt;
2826 struct rttimer *r;
2827 {
2828 if (rt == NULL)
2829 panic("icmp6_redirect_timeout: bad route to timeout");
2830 if ((rt->rt_flags & (RTF_GATEWAY | RTF_DYNAMIC | RTF_HOST)) ==
2831 (RTF_GATEWAY | RTF_DYNAMIC | RTF_HOST)) {
2832 rtrequest((int) RTM_DELETE, (struct sockaddr *)rt_key(rt),
2833 rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
2834 }
2835 }
2836
2837 #include <uvm/uvm_extern.h>
2838 #include <sys/sysctl.h>
2839
2840 int *icmpv6ctl_vars[ICMPV6CTL_MAXID] = ICMPV6CTL_VARS;
2841
2842 int
icmp6_sysctl(name,namelen,oldp,oldlenp,newp,newlen)2843 icmp6_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
2844 int *name;
2845 u_int namelen;
2846 void *oldp;
2847 size_t *oldlenp;
2848 void *newp;
2849 size_t newlen;
2850 {
2851
2852 /* All sysctl names at this level are terminal. */
2853 if (namelen != 1)
2854 return ENOTDIR;
2855
2856 switch (name[0]) {
2857
2858 case ICMPV6CTL_STATS:
2859 return sysctl_rdstruct(oldp, oldlenp, newp,
2860 &icmp6stat, sizeof(icmp6stat));
2861 case ICMPV6CTL_ND6_DRLIST:
2862 case ICMPV6CTL_ND6_PRLIST:
2863 return nd6_sysctl(name[0], oldp, oldlenp, newp, newlen);
2864 default:
2865 if (name[0] < ICMPV6CTL_MAXID)
2866 return (sysctl_int_arr(icmpv6ctl_vars, name, namelen,
2867 oldp, oldlenp, newp, newlen));
2868 return ENOPROTOOPT;
2869 }
2870 /* NOTREACHED */
2871 }
2872