1 /* $FreeBSD: src/sys/netinet6/icmp6.c,v 1.6.2.13 2003/05/06 06:46:58 suz Exp $ */
2 /* $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun 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 "opt_inet.h"
65 #include "opt_inet6.h"
66
67 #include <sys/param.h>
68 #include <sys/systm.h>
69 #include <sys/malloc.h>
70 #include <sys/mbuf.h>
71 #include <sys/protosw.h>
72 #include <sys/socket.h>
73 #include <sys/socketvar.h>
74 #include <sys/socketops.h>
75 #include <sys/time.h>
76 #include <sys/kernel.h>
77 #include <sys/syslog.h>
78 #include <sys/domain.h>
79
80 #include <sys/thread2.h>
81 #include <sys/msgport2.h>
82
83 #include <net/if.h>
84 #include <net/route.h>
85 #include <net/if_dl.h>
86 #include <net/if_types.h>
87 #include <net/netisr2.h>
88 #include <net/netmsg2.h>
89
90 #include <netinet/in.h>
91 #include <netinet/in_var.h>
92 #include <netinet/ip6.h>
93 #include <netinet6/ip6_var.h>
94 #include <netinet/icmp6.h>
95 #include <netinet6/mld6_var.h>
96 #include <netinet/in_pcb.h>
97 #include <netinet6/in6_pcb.h>
98 #include <netinet6/nd6.h>
99 #include <netinet6/in6_ifattach.h>
100 #include <netinet6/ip6protosw.h>
101
102 #include <net/net_osdep.h>
103
104 #ifdef HAVE_NRL_INPCB
105 /* inpcb members */
106 #define in6pcb inpcb
107 #define in6p_laddr inp_laddr6
108 #define in6p_faddr inp_faddr6
109 #define in6p_icmp6filt inp_icmp6filt
110 #define in6p_route inp_route
111 #define in6p_socket inp_socket
112 #define in6p_flags inp_flags
113 #define in6p_moptions inp_moptions6
114 #define in6p_outputopts inp_outputopts6
115 #define in6p_ip6 inp_ipv6
116 #define in6p_flowinfo inp_flowinfo
117 #define in6p_next inp_next
118 #define in6p_prev inp_prev
119 /* function names */
120 #define in6_pcbdetach in_pcbdetach
121 #define in6_rtchange in_rtchange
122
123 /*
124 * for KAME src sync over BSD*'s. XXX: FreeBSD (>=3) are VERY different from
125 * others...
126 */
127 #define in6p_ip6_nxt inp_ipv6.ip6_nxt
128 #endif
129
130 #define ICMP6_FASTTIMO (hz / PR_FASTHZ)
131
132 /*
133 * ppratecheck() is available, so define it here.
134 */
135 #define HAVE_PPSRATECHECK
136
137 extern struct domain inet6domain;
138 extern struct protosw inet6sw[];
139 extern u_char ip6_protox[];
140
141 struct icmp6stat icmp6stat;
142
143 extern struct inpcbinfo ripcbinfo;
144 extern int icmp6errppslim;
145 static int icmp6errpps_count = 0;
146 static struct timeval icmp6errppslim_last;
147 extern int icmp6_nodeinfo;
148
149 static void icmp6_errcount (struct icmp6errstat *, int, int);
150 static int icmp6_rip6_input (struct mbuf **, int);
151 static int icmp6_ratelimit (const struct in6_addr *, const int, const int);
152 static const char *icmp6_redirect_diag (struct in6_addr *,
153 struct in6_addr *, struct in6_addr *);
154 #ifndef HAVE_PPSRATECHECK
155 static int ppsratecheck (struct timeval *, int *, int);
156 #endif
157 static struct mbuf *ni6_input (struct mbuf *, int);
158 static struct mbuf *ni6_nametodns (const char *, int, int);
159 static int ni6_dnsmatch (const char *, int, const char *, int);
160 static int ni6_addrs (struct icmp6_nodeinfo *, struct mbuf *,
161 struct ifnet **, char *);
162 static int ni6_store_addrs (struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
163 struct ifnet *, int);
164 static int icmp6_notify_error (struct mbuf *, int, int, int);
165
166 static void icmp6_fasttimo(void *);
167 static void icmp6_fasttimo_dispatch(netmsg_t);
168
169 #ifdef COMPAT_RFC1885
170 static struct route_in6 icmp6_reflect_rt;
171 #endif
172
173 static struct callout icmp6_fasttimo_ch;
174 static struct netmsg_base icmp6_fasttimo_nmsg;
175
176 void
icmp6_init(void)177 icmp6_init(void)
178 {
179
180 mld6_init();
181
182 callout_init_mp(&icmp6_fasttimo_ch);
183 netmsg_init(&icmp6_fasttimo_nmsg, NULL, &netisr_adone_rport,
184 MSGF_PRIORITY, icmp6_fasttimo_dispatch);
185
186 callout_reset_bycpu(&icmp6_fasttimo_ch, ICMP6_FASTTIMO,
187 icmp6_fasttimo, NULL, 0);
188 }
189
190 static void
icmp6_errcount(struct icmp6errstat * stat,int type,int code)191 icmp6_errcount(struct icmp6errstat *stat, int type, int code)
192 {
193 switch (type) {
194 case ICMP6_DST_UNREACH:
195 switch (code) {
196 case ICMP6_DST_UNREACH_NOROUTE:
197 stat->icp6errs_dst_unreach_noroute++;
198 return;
199 case ICMP6_DST_UNREACH_ADMIN:
200 stat->icp6errs_dst_unreach_admin++;
201 return;
202 case ICMP6_DST_UNREACH_BEYONDSCOPE:
203 stat->icp6errs_dst_unreach_beyondscope++;
204 return;
205 case ICMP6_DST_UNREACH_ADDR:
206 stat->icp6errs_dst_unreach_addr++;
207 return;
208 case ICMP6_DST_UNREACH_NOPORT:
209 stat->icp6errs_dst_unreach_noport++;
210 return;
211 }
212 break;
213 case ICMP6_PACKET_TOO_BIG:
214 stat->icp6errs_packet_too_big++;
215 return;
216 case ICMP6_TIME_EXCEEDED:
217 switch (code) {
218 case ICMP6_TIME_EXCEED_TRANSIT:
219 stat->icp6errs_time_exceed_transit++;
220 return;
221 case ICMP6_TIME_EXCEED_REASSEMBLY:
222 stat->icp6errs_time_exceed_reassembly++;
223 return;
224 }
225 break;
226 case ICMP6_PARAM_PROB:
227 switch (code) {
228 case ICMP6_PARAMPROB_HEADER:
229 stat->icp6errs_paramprob_header++;
230 return;
231 case ICMP6_PARAMPROB_NEXTHEADER:
232 stat->icp6errs_paramprob_nextheader++;
233 return;
234 case ICMP6_PARAMPROB_OPTION:
235 stat->icp6errs_paramprob_option++;
236 return;
237 }
238 break;
239 case ND_REDIRECT:
240 stat->icp6errs_redirect++;
241 return;
242 }
243 stat->icp6errs_unknown++;
244 }
245
246 /*
247 * Generate an error packet of type error in response to bad IP6 packet.
248 */
249 void
icmp6_error(struct mbuf * m,int type,int code,int param)250 icmp6_error(struct mbuf *m, int type, int code, int param)
251 {
252 struct ip6_hdr *oip6, *nip6;
253 struct icmp6_hdr *icmp6;
254 u_int preplen;
255 int off;
256 int nxt;
257
258 icmp6stat.icp6s_error++;
259
260 /* count per-type-code statistics */
261 icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
262
263 #ifdef M_DECRYPTED /*not openbsd*/
264 if (m->m_flags & M_DECRYPTED) {
265 icmp6stat.icp6s_canterror++;
266 goto freeit;
267 }
268 #endif
269
270 #ifndef PULLDOWN_TEST
271 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
272 #else
273 if (m->m_len < sizeof(struct ip6_hdr)) {
274 m = m_pullup(m, sizeof(struct ip6_hdr));
275 if (m == NULL)
276 return;
277 }
278 #endif
279 oip6 = mtod(m, struct ip6_hdr *);
280 if ((oip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
281 kprintf("%s to %s not IPv6 (%d != %d)\n",
282 __func__, ip6_sprintf(&oip6->ip6_src),
283 oip6->ip6_vfc & IPV6_VERSION_MASK, IPV6_VERSION);
284 goto freeit;
285 }
286
287 /*
288 * Multicast destination check. For unrecognized option errors,
289 * this check has already done in ip6_unknown_opt(), so we can
290 * check only for other errors.
291 */
292 if ((m->m_flags & (M_BCAST|M_MCAST) ||
293 IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
294 (type != ICMP6_PACKET_TOO_BIG &&
295 (type != ICMP6_PARAM_PROB ||
296 code != ICMP6_PARAMPROB_OPTION)))
297 goto freeit;
298
299 /* Source address check. XXX: the case of anycast source? */
300 if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
301 IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
302 goto freeit;
303
304 /*
305 * If we are about to send ICMPv6 against ICMPv6 error/redirect,
306 * don't do it.
307 */
308 nxt = -1;
309 off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
310 if (off >= 0 && nxt == IPPROTO_ICMPV6) {
311 struct icmp6_hdr *icp;
312
313 #ifndef PULLDOWN_TEST
314 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
315 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
316 #else
317 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
318 sizeof(*icp));
319 if (icp == NULL) {
320 icmp6stat.icp6s_tooshort++;
321 return;
322 }
323 #endif
324 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
325 icp->icmp6_type == ND_REDIRECT) {
326 /*
327 * ICMPv6 error
328 * Special case: for redirect (which is
329 * informational) we must not send icmp6 error.
330 */
331 icmp6stat.icp6s_canterror++;
332 goto freeit;
333 } else {
334 /* ICMPv6 informational - send the error */
335 }
336 } else {
337 /* non-ICMPv6 - send the error */
338 }
339
340 oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
341
342 /* Finally, do rate limitation check. */
343 if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
344 icmp6stat.icp6s_toofreq++;
345 goto freeit;
346 }
347
348 /*
349 * OK, ICMP6 can be generated.
350 */
351
352 if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
353 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
354
355 preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
356 M_PREPEND(m, preplen, M_NOWAIT);
357 if (m && m->m_len < preplen)
358 m = m_pullup(m, preplen);
359 if (m == NULL) {
360 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
361 return;
362 }
363
364 nip6 = mtod(m, struct ip6_hdr *);
365 nip6->ip6_src = oip6->ip6_src;
366 nip6->ip6_dst = oip6->ip6_dst;
367
368 in6_clearscope(&oip6->ip6_src);
369 in6_clearscope(&oip6->ip6_dst);
370
371 icmp6 = (struct icmp6_hdr *)(nip6 + 1);
372 icmp6->icmp6_type = type;
373 icmp6->icmp6_code = code;
374 icmp6->icmp6_pptr = htonl((u_int32_t)param);
375
376 /*
377 * icmp6_reflect() is designed to be in the input path.
378 * icmp6_error() can be called from both input and outut path,
379 * and if we are in output path rcvif could contain bogus value.
380 * clear m->m_pkthdr.rcvif for safety, we should have enough scope
381 * information in ip header (nip6).
382 */
383 m->m_pkthdr.rcvif = NULL;
384
385 icmp6stat.icp6s_outhist[type]++;
386 icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
387
388 return;
389
390 freeit:
391 /*
392 * If we can't tell wheter or not we can generate ICMP6, free it.
393 */
394 m_freem(m);
395 }
396
397 /*
398 * Process a received ICMP6 message.
399 */
400 int
icmp6_input(struct mbuf ** mp,int * offp,int proto)401 icmp6_input(struct mbuf **mp, int *offp, int proto)
402 {
403 struct mbuf *m = *mp, *n;
404 struct ip6_hdr *ip6, *nip6;
405 struct icmp6_hdr *icmp6, *nicmp6;
406 int off = *offp;
407 int icmp6len = m->m_pkthdr.len - *offp;
408 int code, sum, noff;
409
410 #ifndef PULLDOWN_TEST
411 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
412 /* m might change if M_LOOP. So, call mtod after this */
413 #endif
414
415 /*
416 * Locate icmp6 structure in mbuf, and check
417 * that not corrupted and of at least minimum length
418 */
419
420 ip6 = mtod(m, struct ip6_hdr *);
421 if (icmp6len < sizeof(struct icmp6_hdr)) {
422 icmp6stat.icp6s_tooshort++;
423 goto freeit;
424 }
425
426 /*
427 * calculate the checksum
428 */
429 #ifndef PULLDOWN_TEST
430 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
431 #else
432 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
433 if (icmp6 == NULL) {
434 icmp6stat.icp6s_tooshort++;
435 return IPPROTO_DONE;
436 }
437 #endif
438 code = icmp6->icmp6_code;
439
440 if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
441 nd6log((LOG_ERR,
442 "ICMP6 checksum error(%d|%x) %s\n",
443 icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src)));
444 icmp6stat.icp6s_checksum++;
445 goto freeit;
446 }
447
448 icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
449 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
450 if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
451 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
452
453 switch (icmp6->icmp6_type) {
454 case ICMP6_DST_UNREACH:
455 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
456 switch (code) {
457 case ICMP6_DST_UNREACH_NOROUTE:
458 code = PRC_UNREACH_NET;
459 break;
460 case ICMP6_DST_UNREACH_ADMIN:
461 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
462 code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
463 break;
464 case ICMP6_DST_UNREACH_ADDR:
465 code = PRC_HOSTDEAD;
466 break;
467 #ifdef COMPAT_RFC1885
468 case ICMP6_DST_UNREACH_NOTNEIGHBOR:
469 code = PRC_UNREACH_SRCFAIL;
470 break;
471 #else
472 case ICMP6_DST_UNREACH_BEYONDSCOPE:
473 /* I mean "source address was incorrect." */
474 code = PRC_PARAMPROB;
475 break;
476 #endif
477 case ICMP6_DST_UNREACH_NOPORT:
478 code = PRC_UNREACH_PORT;
479 break;
480 default:
481 goto badcode;
482 }
483 goto deliver;
484 break;
485
486 case ICMP6_PACKET_TOO_BIG:
487 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
488 if (code != 0)
489 goto badcode;
490
491 code = PRC_MSGSIZE;
492
493 /*
494 * Updating the path MTU will be done after examining
495 * intermediate extension headers.
496 */
497 goto deliver;
498 break;
499
500 case ICMP6_TIME_EXCEEDED:
501 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
502 switch (code) {
503 case ICMP6_TIME_EXCEED_TRANSIT:
504 case ICMP6_TIME_EXCEED_REASSEMBLY:
505 code += PRC_TIMXCEED_INTRANS;
506 break;
507 default:
508 goto badcode;
509 }
510 goto deliver;
511 break;
512
513 case ICMP6_PARAM_PROB:
514 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
515 switch (code) {
516 case ICMP6_PARAMPROB_NEXTHEADER:
517 code = PRC_UNREACH_PROTOCOL;
518 break;
519 case ICMP6_PARAMPROB_HEADER:
520 case ICMP6_PARAMPROB_OPTION:
521 code = PRC_PARAMPROB;
522 break;
523 default:
524 goto badcode;
525 }
526 goto deliver;
527 break;
528
529 case ICMP6_ECHO_REQUEST:
530 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
531 if (code != 0)
532 goto badcode;
533 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
534 /* Give up remote */
535 break;
536 }
537 if ((n->m_flags & M_EXT) ||
538 n->m_len < off + sizeof(struct icmp6_hdr)) {
539 struct mbuf *n0 = n;
540 const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
541 int n0len;
542
543 /*
544 * Prepare an internal mbuf. m_pullup() doesn't
545 * always copy the length we specified.
546 */
547 if (maxlen >= MCLBYTES) {
548 /* Give up remote */
549 m_freem(n0);
550 break;
551 }
552 n = m_getb(maxlen, M_NOWAIT, n0->m_type, M_PKTHDR);
553 if (n == NULL) {
554 /* Give up remote */
555 m_freem(n0);
556 break;
557 }
558 n0len = n0->m_pkthdr.len; /* save for use below */
559 M_MOVE_PKTHDR(n, n0);
560 /*
561 * Copy IPv6 and ICMPv6 only.
562 */
563 nip6 = mtod(n, struct ip6_hdr *);
564 bcopy(ip6, nip6, sizeof(struct ip6_hdr));
565 nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
566 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
567 noff = sizeof(struct ip6_hdr);
568 /* new mbuf contains only ipv6+icmpv6 headers */
569 n->m_len = noff + sizeof(struct icmp6_hdr);
570 /*
571 * Adjust mbuf. ip6_plen will be adjusted in
572 * ip6_output().
573 */
574 m_adj(n0, off + sizeof(struct icmp6_hdr));
575 /* recalculate complete packet size */
576 n->m_pkthdr.len = n0len + (noff - off);
577 n->m_next = n0;
578 } else {
579 nip6 = mtod(n, struct ip6_hdr *);
580 nicmp6 = (struct icmp6_hdr *)((caddr_t)nip6 + off);
581 noff = off;
582 }
583 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
584 nicmp6->icmp6_code = 0;
585 if (n) {
586 icmp6stat.icp6s_reflect++;
587 icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
588 icmp6_reflect(n, noff);
589 }
590 break;
591
592 case ICMP6_ECHO_REPLY:
593 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
594 if (code != 0)
595 goto badcode;
596 break;
597
598 case MLD_LISTENER_QUERY:
599 case MLD_LISTENER_REPORT:
600 if (icmp6len < sizeof(struct mld_hdr))
601 goto badlen;
602 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
603 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
604 else
605 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
606 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
607 /* give up local */
608 mld6_input(m, off);
609 m = NULL;
610 goto freeit;
611 }
612 mld6_input(n, off);
613 /* m stays. */
614 break;
615
616 case MLD_LISTENER_DONE:
617 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
618 if (icmp6len < sizeof(struct mld_hdr)) /* necessary? */
619 goto badlen;
620 break; /* nothing to be done in kernel */
621
622 case MLD_MTRACE_RESP:
623 case MLD_MTRACE:
624 /* XXX: these two are experimental. not officially defind. */
625 /* XXX: per-interface statistics? */
626 break; /* just pass it to applications */
627
628 case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */
629 {
630 enum { WRU, FQDN } mode;
631
632 if (!icmp6_nodeinfo)
633 break;
634
635 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
636 mode = WRU;
637 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
638 mode = FQDN;
639 else
640 goto badlen;
641
642 #define hostnamelen strlen(hostname)
643 if (mode == FQDN) {
644 #ifndef PULLDOWN_TEST
645 IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
646 IPPROTO_DONE);
647 #endif
648 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
649 if (n != NULL)
650 n = ni6_input(n, off);
651 /* XXX meaningless if n == NULL */
652 noff = sizeof(struct ip6_hdr);
653 } else {
654 u_char *p;
655 int maxlen, maxhlen;
656
657 if ((icmp6_nodeinfo & 5) != 5)
658 break;
659
660 if (code != 0)
661 goto badcode;
662 maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
663 if (maxlen >= MCLBYTES) {
664 /* Give up remote */
665 break;
666 }
667 n = m_getb(maxlen, M_NOWAIT, m->m_type, M_PKTHDR);
668 if (n == NULL) {
669 /* Give up remote */
670 break;
671 }
672 if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
673 /*
674 * Previous code did a blind M_COPY_PKTHDR
675 * and said "just for rcvif". If true, then
676 * we could tolerate the dup failing (due to
677 * the deep copy of the tag chain). For now
678 * be conservative and just fail.
679 */
680 m_free(n);
681 break;
682 }
683 n->m_len = 0;
684 maxhlen = M_TRAILINGSPACE(n) - maxlen;
685 if (maxhlen > hostnamelen)
686 maxhlen = hostnamelen;
687 /*
688 * Copy IPv6 and ICMPv6 only.
689 */
690 nip6 = mtod(n, struct ip6_hdr *);
691 bcopy(ip6, nip6, sizeof(struct ip6_hdr));
692 nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
693 bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
694 p = (u_char *)(nicmp6 + 1);
695 bzero(p, 4);
696 bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */
697 noff = sizeof(struct ip6_hdr);
698 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
699 sizeof(struct icmp6_hdr) + 4 + maxhlen;
700 nicmp6->icmp6_type = ICMP6_WRUREPLY;
701 nicmp6->icmp6_code = 0;
702 }
703 #undef hostnamelen
704 if (n) {
705 icmp6stat.icp6s_reflect++;
706 icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
707 icmp6_reflect(n, noff);
708 }
709 break;
710 }
711
712 case ICMP6_WRUREPLY:
713 if (code != 0)
714 goto badcode;
715 break;
716
717 case ND_ROUTER_SOLICIT:
718 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
719 if (code != 0)
720 goto badcode;
721 if (icmp6len < sizeof(struct nd_router_solicit))
722 goto badlen;
723 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
724 /* give up local */
725 nd6_rs_input(m, off, icmp6len);
726 m = NULL;
727 goto freeit;
728 }
729 nd6_rs_input(n, off, icmp6len);
730 /* m stays. */
731 break;
732
733 case ND_ROUTER_ADVERT:
734 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
735 if (code != 0)
736 goto badcode;
737 if (icmp6len < sizeof(struct nd_router_advert))
738 goto badlen;
739 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
740 /* give up local */
741 nd6_ra_input(m, off, icmp6len);
742 m = NULL;
743 goto freeit;
744 }
745 nd6_ra_input(n, off, icmp6len);
746 /* m stays. */
747 break;
748
749 case ND_NEIGHBOR_SOLICIT:
750 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
751 if (code != 0)
752 goto badcode;
753 if (icmp6len < sizeof(struct nd_neighbor_solicit))
754 goto badlen;
755 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
756 /* give up local */
757 nd6_ns_input(m, off, icmp6len);
758 m = NULL;
759 goto freeit;
760 }
761 nd6_ns_input(n, off, icmp6len);
762 /* m stays. */
763 break;
764
765 case ND_NEIGHBOR_ADVERT:
766 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
767 if (code != 0)
768 goto badcode;
769 if (icmp6len < sizeof(struct nd_neighbor_advert))
770 goto badlen;
771 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
772 /* give up local */
773 nd6_na_input(m, off, icmp6len);
774 m = NULL;
775 goto freeit;
776 }
777 nd6_na_input(n, off, icmp6len);
778 /* m stays. */
779 break;
780
781 case ND_REDIRECT:
782 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
783 if (code != 0)
784 goto badcode;
785 if (icmp6len < sizeof(struct nd_redirect))
786 goto badlen;
787 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
788 /* give up local */
789 icmp6_redirect_input(m, off);
790 m = NULL;
791 goto freeit;
792 }
793 icmp6_redirect_input(n, off);
794 /* m stays. */
795 break;
796
797 case ICMP6_ROUTER_RENUMBERING:
798 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
799 code != ICMP6_ROUTER_RENUMBERING_RESULT)
800 goto badcode;
801 if (icmp6len < sizeof(struct icmp6_router_renum))
802 goto badlen;
803 break;
804
805 default:
806 nd6log((LOG_DEBUG,
807 "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
808 icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src),
809 ip6_sprintf(&ip6->ip6_dst),
810 m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
811 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
812 /* ICMPv6 error: MUST deliver it by spec... */
813 code = PRC_NCMDS;
814 /* deliver */
815 } else {
816 /* ICMPv6 informational: MUST not deliver */
817 break;
818 }
819 deliver:
820 if (icmp6_notify_error(m, off, icmp6len, code)) {
821 /* In this case, m should've been freed. */
822 return (IPPROTO_DONE);
823 }
824 break;
825
826 badcode:
827 icmp6stat.icp6s_badcode++;
828 break;
829
830 badlen:
831 icmp6stat.icp6s_badlen++;
832 break;
833 }
834
835 /* deliver the packet to appropriate sockets */
836 icmp6_rip6_input(&m, *offp);
837
838 return IPPROTO_DONE;
839
840 freeit:
841 m_freem(m);
842 return IPPROTO_DONE;
843 }
844
845 static int
icmp6_notify_error(struct mbuf * m,int off,int icmp6len,int code)846 icmp6_notify_error(struct mbuf *m, int off, int icmp6len, int code)
847 {
848 struct icmp6_hdr *icmp6;
849 struct ip6_hdr *eip6;
850 u_int32_t notifymtu;
851 struct sockaddr_in6 icmp6src, icmp6dst;
852
853 if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
854 icmp6stat.icp6s_tooshort++;
855 goto freeit;
856 }
857 #ifndef PULLDOWN_TEST
858 IP6_EXTHDR_CHECK(m, off,
859 sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr),
860 -1);
861 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
862 #else
863 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
864 sizeof(*icmp6) + sizeof(struct ip6_hdr));
865 if (icmp6 == NULL) {
866 icmp6stat.icp6s_tooshort++;
867 return (-1);
868 }
869 #endif
870 eip6 = (struct ip6_hdr *)(icmp6 + 1);
871
872 /* Detect the upper level protocol */
873 {
874 u_int8_t nxt = eip6->ip6_nxt;
875 int eoff = off + sizeof(struct icmp6_hdr) +
876 sizeof(struct ip6_hdr);
877 struct ip6ctlparam ip6cp;
878 struct in6_addr *finaldst = NULL;
879 int icmp6type = icmp6->icmp6_type;
880 struct ip6_frag *fh;
881 struct ip6_rthdr *rth;
882 int rthlen;
883
884 while (1) { /* XXX: should avoid infinite loop explicitly? */
885 struct ip6_ext *eh;
886
887 switch (nxt) {
888 case IPPROTO_HOPOPTS:
889 case IPPROTO_DSTOPTS:
890 case IPPROTO_AH:
891 #ifndef PULLDOWN_TEST
892 IP6_EXTHDR_CHECK(m, 0,
893 eoff + sizeof(struct ip6_ext), -1);
894 eh = (struct ip6_ext *)
895 (mtod(m, caddr_t) + eoff);
896 #else
897 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
898 eoff, sizeof(*eh));
899 if (eh == NULL) {
900 icmp6stat.icp6s_tooshort++;
901 return (-1);
902 }
903 #endif
904
905 if (nxt == IPPROTO_AH)
906 eoff += (eh->ip6e_len + 2) << 2;
907 else
908 eoff += (eh->ip6e_len + 1) << 3;
909 nxt = eh->ip6e_nxt;
910 break;
911 case IPPROTO_ROUTING:
912 /*
913 * When the erroneous packet contains a
914 * routing header, we should examine the
915 * header to determine the final destination.
916 * Otherwise, we can't properly update
917 * information that depends on the final
918 * destination (e.g. path MTU).
919 */
920 #ifndef PULLDOWN_TEST
921 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth),
922 -1);
923 rth = (struct ip6_rthdr *)(mtod(m, caddr_t)
924 + eoff);
925 #else
926 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
927 eoff, sizeof(*rth));
928 if (rth == NULL) {
929 icmp6stat.icp6s_tooshort++;
930 return (-1);
931 }
932 #endif
933 rthlen = (rth->ip6r_len + 1) << 3;
934 eoff += rthlen;
935 nxt = rth->ip6r_nxt;
936 break;
937 case IPPROTO_FRAGMENT:
938 #ifndef PULLDOWN_TEST
939 IP6_EXTHDR_CHECK(m, 0, eoff +
940 sizeof(struct ip6_frag),
941 -1);
942 fh = (struct ip6_frag *)(mtod(m, caddr_t)
943 + eoff);
944 #else
945 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
946 eoff, sizeof(*fh));
947 if (fh == NULL) {
948 icmp6stat.icp6s_tooshort++;
949 return (-1);
950 }
951 #endif
952 /*
953 * Data after a fragment header is meaningless
954 * unless it is the first fragment, but
955 * we'll go to the notify label for path MTU
956 * discovery.
957 */
958 if (fh->ip6f_offlg & IP6F_OFF_MASK)
959 goto notify;
960
961 eoff += sizeof(struct ip6_frag);
962 nxt = fh->ip6f_nxt;
963 break;
964 default:
965 /*
966 * This case includes ESP and the No Next
967 * Header. In such cases going to the notify
968 * label does not have any meaning
969 * (i.e. pr_ctlinput will be NULL), but we go
970 * anyway since we might have to update
971 * path MTU information.
972 */
973 goto notify;
974 }
975 }
976 notify:
977 #ifndef PULLDOWN_TEST
978 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
979 #else
980 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
981 sizeof(*icmp6) + sizeof(struct ip6_hdr));
982 if (icmp6 == NULL) {
983 icmp6stat.icp6s_tooshort++;
984 return (-1);
985 }
986 #endif
987
988 eip6 = (struct ip6_hdr *)(icmp6 + 1);
989 bzero(&icmp6dst, sizeof(icmp6dst));
990 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
991 icmp6dst.sin6_family = AF_INET6;
992 if (finaldst == NULL)
993 icmp6dst.sin6_addr = eip6->ip6_dst;
994 else
995 icmp6dst.sin6_addr = *finaldst;
996 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &icmp6dst.sin6_addr,
997 &icmp6dst.sin6_scope_id))
998 goto freeit;
999 if (in6_embedscope(&icmp6dst.sin6_addr, &icmp6dst,
1000 NULL, NULL)) {
1001 /* should be impossbile */
1002 nd6log((LOG_DEBUG,
1003 "icmp6_notify_error: in6_embedscope failed\n"));
1004 goto freeit;
1005 }
1006
1007 /*
1008 * retrieve parameters from the inner IPv6 header, and convert
1009 * them into sockaddr structures.
1010 */
1011 bzero(&icmp6src, sizeof(icmp6src));
1012 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1013 icmp6src.sin6_family = AF_INET6;
1014 icmp6src.sin6_addr = eip6->ip6_src;
1015 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &icmp6src.sin6_addr,
1016 &icmp6src.sin6_scope_id))
1017 goto freeit;
1018 if (in6_embedscope(&icmp6src.sin6_addr, &icmp6src,
1019 NULL, NULL)) {
1020 /* should be impossbile */
1021 nd6log((LOG_DEBUG,
1022 "icmp6_notify_error: in6_embedscope failed\n"));
1023 goto freeit;
1024 }
1025 icmp6src.sin6_flowinfo =
1026 (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1027
1028 if (finaldst == NULL)
1029 finaldst = &eip6->ip6_dst;
1030 ip6cp.ip6c_m = m;
1031 ip6cp.ip6c_icmp6 = icmp6;
1032 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1033 ip6cp.ip6c_off = eoff;
1034 ip6cp.ip6c_finaldst = finaldst;
1035 ip6cp.ip6c_src = &icmp6src;
1036 ip6cp.ip6c_nxt = nxt;
1037
1038 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1039 notifymtu = ntohl(icmp6->icmp6_mtu);
1040 ip6cp.ip6c_cmdarg = (void *)¬ifymtu;
1041 icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/
1042 }
1043
1044 so_pr_ctlinput(
1045 &inet6sw[ip6_protox[nxt]],
1046 code, (struct sockaddr *)&icmp6dst, &ip6cp);
1047 }
1048 return (0);
1049
1050 freeit:
1051 m_freem(m);
1052 return (-1);
1053 }
1054
1055 void
icmp6_mtudisc_update(struct ip6ctlparam * ip6cp,int validated)1056 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1057 {
1058 struct in6_addr *dst = ip6cp->ip6c_finaldst;
1059 struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1060 struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1061 u_int mtu = ntohl(icmp6->icmp6_mtu);
1062 struct rtentry *rt = NULL;
1063 struct sockaddr_in6 sin6;
1064
1065 if (!validated)
1066 return;
1067
1068 bzero(&sin6, sizeof(sin6));
1069 sin6.sin6_family = PF_INET6;
1070 sin6.sin6_len = sizeof(struct sockaddr_in6);
1071 sin6.sin6_addr = *dst;
1072 /* XXX normally, this won't happen */
1073 if (IN6_IS_ADDR_LINKLOCAL(dst)) {
1074 sin6.sin6_addr.s6_addr16[1] =
1075 htons(m->m_pkthdr.rcvif->if_index);
1076 }
1077 /* sin6.sin6_scope_id = XXX: should be set if DST is a scoped addr */
1078 rt = rtpurelookup((struct sockaddr *)&sin6);
1079 if (rt != NULL && (rt->rt_flags & RTF_HOST) &&
1080 !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
1081 if (mtu < IPV6_MMTU) { /* XXX */
1082 rt->rt_rmx.rmx_locks |= RTV_MTU;
1083 } else if (mtu < rt->rt_ifp->if_mtu &&
1084 rt->rt_rmx.rmx_mtu > mtu) {
1085 icmp6stat.icp6s_pmtuchg++;
1086 rt->rt_rmx.rmx_mtu = mtu;
1087 }
1088 }
1089 if (rt)
1090 --rt->rt_refcnt;
1091 }
1092
1093 /*
1094 * Process a Node Information Query packet, based on
1095 * draft-ietf-ipngwg-icmp-name-lookups-07.
1096 *
1097 * Spec incompatibilities:
1098 * - IPv6 Subject address handling
1099 * - IPv4 Subject address handling support missing
1100 * - Proxy reply (answer even if it's not for me)
1101 * - joins NI group address at in6_ifattach() time only, does not cope
1102 * with hostname changes by sethostname(3)
1103 */
1104 #define hostnamelen strlen(hostname)
1105 static struct mbuf *
ni6_input(struct mbuf * m,int off)1106 ni6_input(struct mbuf *m, int off)
1107 {
1108 struct icmp6_nodeinfo *ni6, *nni6;
1109 struct mbuf *n = NULL;
1110 u_int16_t qtype;
1111 int subjlen;
1112 int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1113 struct ni_reply_fqdn *fqdn;
1114 int addrs; /* for NI_QTYPE_NODEADDR */
1115 struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1116 struct sockaddr_in6 sin6; /* double meaning; ip6_dst and subjectaddr */
1117 struct sockaddr_in6 sin6_d; /* XXX: we should retrieve this from m_aux */
1118 struct ip6_hdr *ip6;
1119 int oldfqdn = 0; /* if 1, return pascal string (03 draft) */
1120 char *subj = NULL;
1121 struct in6_ifaddr *ia6 = NULL;
1122
1123 ip6 = mtod(m, struct ip6_hdr *);
1124 #ifndef PULLDOWN_TEST
1125 ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1126 #else
1127 IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1128 if (ni6 == NULL) {
1129 /* m is already reclaimed */
1130 return NULL;
1131 }
1132 #endif
1133
1134 /*
1135 * Validate IPv6 destination address.
1136 *
1137 * The Responder must discard the Query without further processing
1138 * unless it is one of the Responder's unicast or anycast addresses, or
1139 * a link-local scope multicast address which the Responder has joined.
1140 * [icmp-name-lookups-07, Section 4.]
1141 */
1142 bzero(&sin6, sizeof(sin6));
1143 sin6.sin6_family = AF_INET6;
1144 sin6.sin6_len = sizeof(struct sockaddr_in6);
1145 bcopy(&ip6->ip6_dst, &sin6.sin6_addr, sizeof(sin6.sin6_addr));
1146 /* XXX scopeid */
1147 if ((ia6 = (struct in6_ifaddr *)ifa_ifwithaddr((struct sockaddr *)&sin6)) != NULL) {
1148 /* unicast/anycast, fine */
1149 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1150 (icmp6_nodeinfo & 4) == 0) {
1151 nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1152 "a temporary address in %s:%d",
1153 __FILE__, __LINE__));
1154 goto bad;
1155 }
1156 } else if (IN6_IS_ADDR_MC_LINKLOCAL(&sin6.sin6_addr))
1157 ; /* link-local multicast, fine */
1158 else
1159 goto bad;
1160
1161 /* validate query Subject field. */
1162 qtype = ntohs(ni6->ni_qtype);
1163 subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1164 switch (qtype) {
1165 case NI_QTYPE_NOOP:
1166 case NI_QTYPE_SUPTYPES:
1167 /* 07 draft */
1168 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1169 break;
1170 /* FALLTHROUGH */
1171 case NI_QTYPE_FQDN:
1172 case NI_QTYPE_NODEADDR:
1173 switch (ni6->ni_code) {
1174 case ICMP6_NI_SUBJ_IPV6:
1175 #if ICMP6_NI_SUBJ_IPV6 != 0
1176 case 0:
1177 #endif
1178 /*
1179 * backward compatibility - try to accept 03 draft
1180 * format, where no Subject is present.
1181 */
1182 if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1183 subjlen == 0) {
1184 oldfqdn++;
1185 break;
1186 }
1187 #if ICMP6_NI_SUBJ_IPV6 != 0
1188 if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1189 goto bad;
1190 #endif
1191
1192 if (subjlen != sizeof(sin6.sin6_addr))
1193 goto bad;
1194
1195 /*
1196 * Validate Subject address.
1197 *
1198 * Not sure what exactly "address belongs to the node"
1199 * means in the spec, is it just unicast, or what?
1200 *
1201 * At this moment we consider Subject address as
1202 * "belong to the node" if the Subject address equals
1203 * to the IPv6 destination address; validation for
1204 * IPv6 destination address should have done enough
1205 * check for us.
1206 *
1207 * We do not do proxy at this moment.
1208 */
1209 /* m_pulldown instead of copy? */
1210 m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1211 subjlen, &sin6.sin6_addr);
1212 if (in6_addr2zoneid(m->m_pkthdr.rcvif,
1213 &sin6.sin6_addr, &sin6.sin6_scope_id))
1214 goto bad;
1215 in6_embedscope(&sin6.sin6_addr, &sin6, NULL, NULL);
1216 bzero(&sin6_d, sizeof(sin6_d));
1217 sin6_d.sin6_family = AF_INET6; /* not used, actually */
1218 sin6_d.sin6_len = sizeof(sin6_d); /* ditto */
1219 sin6_d.sin6_addr = ip6->ip6_dst;
1220 if (in6_addr2zoneid(m->m_pkthdr.rcvif,
1221 &ip6->ip6_dst, &sin6_d.sin6_scope_id))
1222 goto bad;
1223 in6_embedscope(&sin6_d.sin6_addr, &sin6_d, NULL, NULL);
1224 subj = (char *)&sin6;
1225 if (SA6_ARE_ADDR_EQUAL(&sin6, &sin6_d))
1226 break;
1227
1228 /*
1229 * XXX if we are to allow other cases, we should really
1230 * be careful about scope here.
1231 * basically, we should disallow queries toward IPv6
1232 * destination X with subject Y, if scope(X) > scope(Y).
1233 * if we allow scope(X) > scope(Y), it will result in
1234 * information leakage across scope boundary.
1235 */
1236 goto bad;
1237
1238 case ICMP6_NI_SUBJ_FQDN:
1239 /*
1240 * Validate Subject name with gethostname(3).
1241 *
1242 * The behavior may need some debate, since:
1243 * - we are not sure if the node has FQDN as
1244 * hostname (returned by gethostname(3)).
1245 * - the code does wildcard match for truncated names.
1246 * however, we are not sure if we want to perform
1247 * wildcard match, if gethostname(3) side has
1248 * truncated hostname.
1249 */
1250 n = ni6_nametodns(hostname, hostnamelen, 0);
1251 if (!n || n->m_next || n->m_len == 0)
1252 goto bad;
1253 IP6_EXTHDR_GET(subj, char *, m,
1254 off + sizeof(struct icmp6_nodeinfo), subjlen);
1255 if (subj == NULL)
1256 goto bad;
1257 if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1258 n->m_len)) {
1259 goto bad;
1260 }
1261 m_freem(n);
1262 n = NULL;
1263 break;
1264
1265 case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */
1266 default:
1267 goto bad;
1268 }
1269 break;
1270 }
1271
1272 /* refuse based on configuration. XXX ICMP6_NI_REFUSED? */
1273 switch (qtype) {
1274 case NI_QTYPE_FQDN:
1275 if ((icmp6_nodeinfo & 1) == 0)
1276 goto bad;
1277 break;
1278 case NI_QTYPE_NODEADDR:
1279 if ((icmp6_nodeinfo & 2) == 0)
1280 goto bad;
1281 break;
1282 }
1283
1284 /* guess reply length */
1285 switch (qtype) {
1286 case NI_QTYPE_NOOP:
1287 break; /* no reply data */
1288 case NI_QTYPE_SUPTYPES:
1289 replylen += sizeof(u_int32_t);
1290 break;
1291 case NI_QTYPE_FQDN:
1292 /* XXX will append an mbuf */
1293 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1294 break;
1295 case NI_QTYPE_NODEADDR:
1296 addrs = ni6_addrs(ni6, m, &ifp, subj);
1297 if ((replylen += addrs * (sizeof(struct in6_addr) +
1298 sizeof(u_int32_t))) > MCLBYTES)
1299 replylen = MCLBYTES; /* XXX: will truncate pkt later */
1300 break;
1301 default:
1302 /*
1303 * XXX: We must return a reply with the ICMP6 code
1304 * `unknown Qtype' in this case. However we regard the case
1305 * as an FQDN query for backward compatibility.
1306 * Older versions set a random value to this field,
1307 * so it rarely varies in the defined qtypes.
1308 * But the mechanism is not reliable...
1309 * maybe we should obsolete older versions.
1310 */
1311 qtype = NI_QTYPE_FQDN;
1312 /* XXX will append an mbuf */
1313 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1314 oldfqdn++;
1315 break;
1316 }
1317
1318 /* allocate an mbuf to reply. */
1319 if (replylen > MCLBYTES) {
1320 /*
1321 * XXX: should we try to allocate more? But MCLBYTES
1322 * is probably much larger than IPV6_MMTU...
1323 */
1324 goto bad;
1325 }
1326 n = m_getb(replylen, M_NOWAIT, m->m_type, M_PKTHDR);
1327 if (n == NULL) {
1328 m_freem(m);
1329 return (NULL);
1330 }
1331 M_MOVE_PKTHDR(n, m); /* just for recvif */
1332 n->m_pkthdr.len = n->m_len = replylen;
1333
1334 /* copy mbuf header and IPv6 + Node Information base headers */
1335 bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1336 nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1337 bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1338
1339 /* qtype dependent procedure */
1340 switch (qtype) {
1341 case NI_QTYPE_NOOP:
1342 nni6->ni_code = ICMP6_NI_SUCCESS;
1343 nni6->ni_flags = 0;
1344 break;
1345 case NI_QTYPE_SUPTYPES:
1346 {
1347 u_int32_t v;
1348 nni6->ni_code = ICMP6_NI_SUCCESS;
1349 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1350 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1351 v = (u_int32_t)htonl(0x0000000f);
1352 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1353 break;
1354 }
1355 case NI_QTYPE_FQDN:
1356 nni6->ni_code = ICMP6_NI_SUCCESS;
1357 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1358 sizeof(struct ip6_hdr) +
1359 sizeof(struct icmp6_nodeinfo));
1360 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1361 fqdn->ni_fqdn_ttl = 0; /* ditto. */
1362 /*
1363 * XXX do we really have FQDN in variable "hostname"?
1364 */
1365 n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
1366 if (n->m_next == NULL)
1367 goto bad;
1368 /* XXX we assume that n->m_next is not a chain */
1369 if (n->m_next->m_next != NULL)
1370 goto bad;
1371 n->m_pkthdr.len += n->m_next->m_len;
1372 break;
1373 case NI_QTYPE_NODEADDR:
1374 {
1375 int lenlim, copied;
1376
1377 nni6->ni_code = ICMP6_NI_SUCCESS;
1378 n->m_pkthdr.len = n->m_len =
1379 sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1380 lenlim = M_TRAILINGSPACE(n);
1381 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1382 /* XXX: reset mbuf length */
1383 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1384 sizeof(struct icmp6_nodeinfo) + copied;
1385 break;
1386 }
1387 default:
1388 break; /* XXX impossible! */
1389 }
1390
1391 nni6->ni_type = ICMP6_NI_REPLY;
1392 m_freem(m);
1393 return (n);
1394
1395 bad:
1396 m_freem(m);
1397 if (n)
1398 m_freem(n);
1399 return (NULL);
1400 }
1401 #undef hostnamelen
1402
1403 /*
1404 * make a mbuf with DNS-encoded string. no compression support.
1405 *
1406 * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1407 * treated as truncated name (two \0 at the end). this is a wild guess.
1408 */
1409 static struct mbuf *
ni6_nametodns(const char * name,int namelen,int old)1410 ni6_nametodns(const char *name, int namelen,
1411 int old) /* return pascal string if non-zero */
1412 {
1413 struct mbuf *m;
1414 char *cp, *ep;
1415 const char *p, *q;
1416 int i, len, nterm;
1417
1418 if (old)
1419 len = namelen + 1;
1420 else
1421 len = MCLBYTES;
1422
1423 /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1424 m = m_getb(len, M_NOWAIT, MT_DATA, 0);
1425 if (!m)
1426 goto fail;
1427
1428 if (old) {
1429 m->m_len = len;
1430 *mtod(m, char *) = namelen;
1431 bcopy(name, mtod(m, char *) + 1, namelen);
1432 return m;
1433 } else {
1434 m->m_len = 0;
1435 cp = mtod(m, char *);
1436 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1437
1438 /* if not certain about my name, return empty buffer */
1439 if (namelen == 0)
1440 return m;
1441
1442 /*
1443 * guess if it looks like shortened hostname, or FQDN.
1444 * shortened hostname needs two trailing "\0".
1445 */
1446 i = 0;
1447 for (p = name; p < name + namelen; p++) {
1448 if (*p && *p == '.')
1449 i++;
1450 }
1451 if (i < 2)
1452 nterm = 2;
1453 else
1454 nterm = 1;
1455
1456 p = name;
1457 while (cp < ep && p < name + namelen) {
1458 i = 0;
1459 for (q = p; q < name + namelen && *q && *q != '.'; q++)
1460 i++;
1461 /* result does not fit into mbuf */
1462 if (cp + i + 1 >= ep)
1463 goto fail;
1464 /*
1465 * DNS label length restriction, RFC1035 page 8.
1466 * "i == 0" case is included here to avoid returning
1467 * 0-length label on "foo..bar".
1468 */
1469 if (i <= 0 || i >= 64)
1470 goto fail;
1471 *cp++ = i;
1472 bcopy(p, cp, i);
1473 cp += i;
1474 p = q;
1475 if (p < name + namelen && *p == '.')
1476 p++;
1477 }
1478 /* termination */
1479 if (cp + nterm >= ep)
1480 goto fail;
1481 while (nterm-- > 0)
1482 *cp++ = '\0';
1483 m->m_len = cp - mtod(m, char *);
1484 return m;
1485 }
1486
1487 panic("should not reach here");
1488 /* NOTREACHED */
1489
1490 fail:
1491 if (m)
1492 m_freem(m);
1493 return NULL;
1494 }
1495
1496 /*
1497 * check if two DNS-encoded string matches. takes care of truncated
1498 * form (with \0\0 at the end). no compression support.
1499 * XXX upper/lowercase match (see RFC2065)
1500 */
1501 static int
ni6_dnsmatch(const char * a,int alen,const char * b,int blen)1502 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1503 {
1504 const char *a0, *b0;
1505 int l;
1506
1507 /* simplest case - need validation? */
1508 if (alen == blen && bcmp(a, b, alen) == 0)
1509 return 1;
1510
1511 a0 = a;
1512 b0 = b;
1513
1514 /* termination is mandatory */
1515 if (alen < 2 || blen < 2)
1516 return 0;
1517 if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1518 return 0;
1519 alen--;
1520 blen--;
1521
1522 while (a - a0 < alen && b - b0 < blen) {
1523 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1524 return 0;
1525
1526 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1527 return 0;
1528 /* we don't support compression yet */
1529 if (a[0] >= 64 || b[0] >= 64)
1530 return 0;
1531
1532 /* truncated case */
1533 if (a[0] == 0 && a - a0 == alen - 1)
1534 return 1;
1535 if (b[0] == 0 && b - b0 == blen - 1)
1536 return 1;
1537 if (a[0] == 0 || b[0] == 0)
1538 return 0;
1539
1540 if (a[0] != b[0])
1541 return 0;
1542 l = a[0];
1543 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1544 return 0;
1545 if (bcmp(a + 1, b + 1, l) != 0)
1546 return 0;
1547
1548 a += 1 + l;
1549 b += 1 + l;
1550 }
1551
1552 if (a - a0 == alen && b - b0 == blen)
1553 return 1;
1554 else
1555 return 0;
1556 }
1557
1558 /*
1559 * calculate the number of addresses to be returned in the node info reply.
1560 */
1561 static int
ni6_addrs(struct icmp6_nodeinfo * ni6,struct mbuf * m,struct ifnet ** ifpp,char * subj)1562 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1563 char *subj)
1564 {
1565 const struct ifnet_array *arr;
1566 struct in6_ifaddr *ifa6;
1567 struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */
1568 int addrs = 0, addrsofif, iffound = 0;
1569 int niflags = ni6->ni_flags;
1570 int i;
1571
1572 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1573 switch (ni6->ni_code) {
1574 case ICMP6_NI_SUBJ_IPV6:
1575 if (subj == NULL) /* must be impossible... */
1576 return (0);
1577 subj_ip6 = (struct sockaddr_in6 *)subj;
1578 break;
1579 default:
1580 /*
1581 * XXX: we only support IPv6 subject address for
1582 * this Qtype.
1583 */
1584 return (0);
1585 }
1586 }
1587
1588 arr = ifnet_array_get();
1589 for (i = 0; i < arr->ifnet_count; ++i) {
1590 struct ifnet *ifp = arr->ifnet_arr[i];
1591 struct ifaddr_container *ifac;
1592
1593 addrsofif = 0;
1594 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link)
1595 {
1596 struct ifaddr *ifa = ifac->ifa;
1597
1598 if (ifa->ifa_addr->sa_family != AF_INET6)
1599 continue;
1600 ifa6 = (struct in6_ifaddr *)ifa;
1601
1602 if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1603 IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr,
1604 &ifa6->ia_addr.sin6_addr))
1605 iffound = 1;
1606
1607 /*
1608 * IPv4-mapped addresses can only be returned by a
1609 * Node Information proxy, since they represent
1610 * addresses of IPv4-only nodes, which perforce do
1611 * not implement this protocol.
1612 * [icmp-name-lookups-07, Section 5.4]
1613 * So we don't support NI_NODEADDR_FLAG_COMPAT in
1614 * this function at this moment.
1615 */
1616
1617 /* What do we have to do about ::1? */
1618 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1619 case IPV6_ADDR_SCOPE_LINKLOCAL:
1620 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1621 continue;
1622 break;
1623 case IPV6_ADDR_SCOPE_SITELOCAL:
1624 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1625 continue;
1626 break;
1627 case IPV6_ADDR_SCOPE_GLOBAL:
1628 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1629 continue;
1630 break;
1631 default:
1632 continue;
1633 }
1634
1635 /*
1636 * check if anycast is okay.
1637 * XXX: just experimental. not in the spec.
1638 */
1639 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) &&
1640 !(niflags & NI_NODEADDR_FLAG_ANYCAST))
1641 continue; /* we need only unicast addresses */
1642 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) &&
1643 (icmp6_nodeinfo & 4) == 0) {
1644 continue;
1645 }
1646 addrsofif++; /* count the address */
1647 }
1648 if (iffound) {
1649 *ifpp = ifp;
1650 return (addrsofif);
1651 }
1652
1653 addrs += addrsofif;
1654 }
1655
1656 return (addrs);
1657 }
1658
1659 static int
ni6_store_addrs(struct icmp6_nodeinfo * ni6,struct icmp6_nodeinfo * nni6,struct ifnet * ifp0,int resid)1660 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1661 struct ifnet *ifp0, int resid)
1662 {
1663 const struct ifnet_array *arr;
1664 struct in6_ifaddr *ifa6;
1665 int copied = 0, allow_deprecated = 0;
1666 u_char *cp = (u_char *)(nni6 + 1);
1667 int niflags = ni6->ni_flags;
1668 u_int32_t ltime;
1669 int idx, idx_dep = -1;
1670
1671 if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1672 return (0); /* needless to copy */
1673
1674 arr = ifnet_array_get();
1675 if (ifp0 == NULL) {
1676 idx = 0;
1677 } else {
1678 for (idx = 0; idx < arr->ifnet_count; ++idx) {
1679 if (arr->ifnet_arr[idx] == ifp0)
1680 break;
1681 }
1682 }
1683
1684 again:
1685
1686 for (; idx < arr->ifnet_count; ++idx) {
1687 struct ifnet *ifp = arr->ifnet_arr[idx];
1688 struct ifaddr_container *ifac;
1689
1690 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
1691 struct ifaddr *ifa = ifac->ifa;
1692
1693 if (ifa->ifa_addr->sa_family != AF_INET6)
1694 continue;
1695 ifa6 = (struct in6_ifaddr *)ifa;
1696
1697 if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) &&
1698 allow_deprecated == 0) {
1699 /*
1700 * prefererred address should be put before
1701 * deprecated addresses.
1702 */
1703
1704 /* record the interface for later search */
1705 if (idx_dep < 0)
1706 idx_dep = idx;
1707
1708 continue;
1709 }
1710 else if (!(ifa6->ia6_flags & IN6_IFF_DEPRECATED) &&
1711 allow_deprecated != 0)
1712 continue; /* we now collect deprecated addrs */
1713
1714 /* What do we have to do about ::1? */
1715 switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1716 case IPV6_ADDR_SCOPE_LINKLOCAL:
1717 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1718 continue;
1719 break;
1720 case IPV6_ADDR_SCOPE_SITELOCAL:
1721 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1722 continue;
1723 break;
1724 case IPV6_ADDR_SCOPE_GLOBAL:
1725 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1726 continue;
1727 break;
1728 default:
1729 continue;
1730 }
1731
1732 /*
1733 * check if anycast is okay.
1734 * XXX: just experimental. not in the spec.
1735 */
1736 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) &&
1737 !(niflags & NI_NODEADDR_FLAG_ANYCAST))
1738 continue;
1739 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) &&
1740 (icmp6_nodeinfo & 4) == 0) {
1741 continue;
1742 }
1743
1744 /* now we can copy the address */
1745 if (resid < sizeof(struct in6_addr) +
1746 sizeof(u_int32_t)) {
1747 /*
1748 * We give up much more copy.
1749 * Set the truncate flag and return.
1750 */
1751 nni6->ni_flags |=
1752 NI_NODEADDR_FLAG_TRUNCATE;
1753 return (copied);
1754 }
1755
1756 /*
1757 * Set the TTL of the address.
1758 * The TTL value should be one of the following
1759 * according to the specification:
1760 *
1761 * 1. The remaining lifetime of a DHCP lease on the
1762 * address, or
1763 * 2. The remaining Valid Lifetime of a prefix from
1764 * which the address was derived through Stateless
1765 * Autoconfiguration.
1766 *
1767 * Note that we currently do not support stateful
1768 * address configuration by DHCPv6, so the former
1769 * case can't happen.
1770 */
1771 if (ifa6->ia6_lifetime.ia6t_expire == 0)
1772 ltime = ND6_INFINITE_LIFETIME;
1773 else {
1774 if (ifa6->ia6_lifetime.ia6t_expire >
1775 time_uptime)
1776 ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime);
1777 else
1778 ltime = 0;
1779 }
1780
1781 bcopy(<ime, cp, sizeof(u_int32_t));
1782 cp += sizeof(u_int32_t);
1783
1784 /* copy the address itself */
1785 bcopy(&ifa6->ia_addr.sin6_addr, cp,
1786 sizeof(struct in6_addr));
1787 in6_clearscope((struct in6_addr *)cp); /* XXX */
1788 cp += sizeof(struct in6_addr);
1789
1790 resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1791 copied += (sizeof(struct in6_addr) +
1792 sizeof(u_int32_t));
1793 }
1794 if (ifp0) /* we need search only on the specified IF */
1795 break;
1796 }
1797
1798 if (allow_deprecated == 0 && idx_dep >= 0) {
1799 idx = idx_dep;
1800 allow_deprecated = 1;
1801
1802 goto again;
1803 }
1804
1805 return (copied);
1806 }
1807
1808 /*
1809 * XXX almost dup'ed code with rip6_input.
1810 */
1811 static int
icmp6_rip6_input(struct mbuf ** mp,int off)1812 icmp6_rip6_input(struct mbuf **mp, int off)
1813 {
1814 struct mbuf *m = *mp;
1815 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1816 struct in6pcb *in6p;
1817 struct in6pcb *last = NULL;
1818 struct sockaddr_in6 fromsa;
1819 struct icmp6_hdr *icmp6;
1820 struct mbuf *opts = NULL;
1821
1822 #ifndef PULLDOWN_TEST
1823 /* this is assumed to be safe. */
1824 icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1825 #else
1826 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1827 if (icmp6 == NULL) {
1828 /* m is already reclaimed */
1829 return IPPROTO_DONE;
1830 }
1831 #endif
1832
1833 bzero(&fromsa, sizeof(fromsa));
1834 fromsa.sin6_len = sizeof(struct sockaddr_in6);
1835 fromsa.sin6_family = AF_INET6;
1836 /* KAME hack: recover scopeid */
1837 in6_recoverscope(&fromsa, &ip6->ip6_src, m->m_pkthdr.rcvif);
1838
1839 LIST_FOREACH(in6p, &ripcbinfo.pcblisthead, inp_list)
1840 {
1841 if (in6p->inp_flags & INP_PLACEMARKER)
1842 continue;
1843 if (!INP_ISIPV6(in6p))
1844 continue;
1845 if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6)
1846 continue;
1847 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1848 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1849 continue;
1850 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1851 !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1852 continue;
1853 if (in6p->in6p_icmp6filt
1854 && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1855 in6p->in6p_icmp6filt))
1856 continue;
1857 if (last) {
1858 struct socket *so;
1859 struct mbuf *n;
1860
1861 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) {
1862 if (last->in6p_flags & IN6P_CONTROLOPTS)
1863 ip6_savecontrol(last, &opts, ip6, n);
1864 /* strip intermediate headers */
1865 m_adj(n, off);
1866 so = last->in6p_socket;
1867 lwkt_gettoken(&so->so_rcv.ssb_token);
1868 if (ssb_appendaddr(&so->so_rcv,
1869 (struct sockaddr *)&fromsa, n, opts) == 0) {
1870 m_freem(n);
1871 if (opts)
1872 m_freem(opts);
1873 soroverflow(so);
1874 } else {
1875 sorwakeup(so);
1876 }
1877 lwkt_reltoken(&so->so_rcv.ssb_token);
1878 opts = NULL;
1879 }
1880 }
1881 last = in6p;
1882 }
1883 if (last) {
1884 struct socket *so;
1885
1886 if (last->in6p_flags & IN6P_CONTROLOPTS)
1887 ip6_savecontrol(last, &opts, ip6, m);
1888 /* strip intermediate headers */
1889 m_adj(m, off);
1890 so = last->in6p_socket;
1891 lwkt_gettoken(&so->so_rcv.ssb_token);
1892 if (ssb_appendaddr(&so->so_rcv, (struct sockaddr *)&fromsa,
1893 m, opts) == 0) {
1894 m_freem(m);
1895 if (opts)
1896 m_freem(opts);
1897 soroverflow(so);
1898 } else {
1899 sorwakeup(so);
1900 }
1901 lwkt_reltoken(&so->so_rcv.ssb_token);
1902 } else {
1903 m_freem(m);
1904 ip6stat.ip6s_delivered--;
1905 }
1906 return IPPROTO_DONE;
1907 }
1908
1909 /*
1910 * Reflect the ip6 packet back to the source.
1911 * OFF points to the icmp6 header, counted from the top of the mbuf.
1912 */
1913 void
icmp6_reflect(struct mbuf * m,size_t off)1914 icmp6_reflect(struct mbuf *m, size_t off)
1915 {
1916 struct ip6_hdr *ip6;
1917 struct icmp6_hdr *icmp6;
1918 struct in6_ifaddr *ia;
1919 struct in6_addr t, *src = NULL;
1920 int plen;
1921 int type, code;
1922 struct ifnet *outif = NULL;
1923 struct sockaddr_in6 sa6_src, sa6_dst;
1924 #ifdef COMPAT_RFC1885
1925 int mtu = IPV6_MMTU;
1926 struct sockaddr_in6 *sin6 = &icmp6_reflect_rt.ro_dst;
1927 #endif
1928
1929 /* too short to reflect */
1930 if (off < sizeof(struct ip6_hdr)) {
1931 nd6log((LOG_DEBUG,
1932 "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
1933 (u_long)off, (u_long)sizeof(struct ip6_hdr),
1934 __FILE__, __LINE__));
1935 goto bad;
1936 }
1937
1938 /*
1939 * If there are extra headers between IPv6 and ICMPv6, strip
1940 * off that header first.
1941 */
1942 #ifdef DIAGNOSTIC
1943 if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
1944 panic("assumption failed in icmp6_reflect");
1945 #endif
1946 if (off > sizeof(struct ip6_hdr)) {
1947 size_t l;
1948 struct ip6_hdr nip6;
1949
1950 l = off - sizeof(struct ip6_hdr);
1951 m_copydata(m, 0, sizeof(nip6), &nip6);
1952 m_adj(m, l);
1953 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
1954 if (m->m_len < l) {
1955 if ((m = m_pullup(m, l)) == NULL)
1956 return;
1957 }
1958 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
1959 } else /* off == sizeof(struct ip6_hdr) */ {
1960 size_t l;
1961 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
1962 if (m->m_len < l) {
1963 if ((m = m_pullup(m, l)) == NULL)
1964 return;
1965 }
1966 }
1967 plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
1968 ip6 = mtod(m, struct ip6_hdr *);
1969 ip6->ip6_nxt = IPPROTO_ICMPV6;
1970 icmp6 = (struct icmp6_hdr *)(ip6 + 1);
1971 type = icmp6->icmp6_type; /* keep type for statistics */
1972 code = icmp6->icmp6_code; /* ditto. */
1973
1974 t = ip6->ip6_dst;
1975 /*
1976 * ip6_input() drops a packet if its src is multicast.
1977 * So, the src is never multicast.
1978 */
1979 ip6->ip6_dst = ip6->ip6_src;
1980
1981 /*
1982 * XXX: make sure to embed scope zone information, using
1983 * already embedded IDs or the received interface (if any).
1984 * Note that rcvif may be NULL.
1985 * TODO: scoped routing case (XXX).
1986 */
1987 bzero(&sa6_src, sizeof(sa6_src));
1988 sa6_src.sin6_family = AF_INET6;
1989 sa6_src.sin6_len = sizeof(sa6_src);
1990 sa6_src.sin6_addr = ip6->ip6_dst;
1991 in6_recoverscope(&sa6_src, &ip6->ip6_dst, m->m_pkthdr.rcvif);
1992 in6_embedscope(&ip6->ip6_dst, &sa6_src, NULL, NULL);
1993 bzero(&sa6_dst, sizeof(sa6_dst));
1994 sa6_dst.sin6_family = AF_INET6;
1995 sa6_dst.sin6_len = sizeof(sa6_dst);
1996 sa6_dst.sin6_addr = t;
1997 in6_recoverscope(&sa6_dst, &t, m->m_pkthdr.rcvif);
1998 in6_embedscope(&t, &sa6_dst, NULL, NULL);
1999
2000 #ifdef COMPAT_RFC1885
2001 /*
2002 * xxx guess MTU
2003 * RFC 1885 requires that echo reply should be truncated if it
2004 * does not fit in with (return) path MTU, but the description was
2005 * removed in the new spec.
2006 */
2007 if (icmp6_reflect_rt.ro_rt == 0 ||
2008 ! (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_dst))) {
2009 if (icmp6_reflect_rt.ro_rt) {
2010 RTFREE(icmp6_reflect_rt.ro_rt);
2011 icmp6_reflect_rt.ro_rt = 0;
2012 }
2013 bzero(sin6, sizeof(*sin6));
2014 sin6->sin6_family = PF_INET6;
2015 sin6->sin6_len = sizeof(struct sockaddr_in6);
2016 sin6->sin6_addr = ip6->ip6_dst;
2017
2018 rtalloc_ign((struct route *)&icmp6_reflect_rt.ro_rt,
2019 RTF_PRCLONING);
2020 }
2021
2022 if (icmp6_reflect_rt.ro_rt == 0)
2023 goto bad;
2024
2025 if ((icmp6_reflect_rt.ro_rt->rt_flags & RTF_HOST)
2026 && mtu < icmp6_reflect_rt.ro_rt->rt_ifp->if_mtu)
2027 mtu = icmp6_reflect_rt.ro_rt->rt_rmx.rmx_mtu;
2028
2029 if (mtu < m->m_pkthdr.len) {
2030 plen -= (m->m_pkthdr.len - mtu);
2031 m_adj(m, mtu - m->m_pkthdr.len);
2032 }
2033 #endif
2034 /*
2035 * If the incoming packet was addressed directly to us(i.e. unicast),
2036 * use dst as the src for the reply.
2037 * The IN6_IFF_NOTREADY case would be VERY rare, but is possible
2038 * (for example) when we encounter an error while forwarding procedure
2039 * destined to a duplicated address of ours.
2040 */
2041 for (ia = in6_ifaddr; ia; ia = ia->ia_next)
2042 if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) &&
2043 (ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) {
2044 src = &t;
2045 break;
2046 }
2047 if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) && (m->m_flags & M_LOOP)) {
2048 /*
2049 * This is the case if the dst is our link-local address
2050 * and the sender is also ourselves.
2051 */
2052 src = &t;
2053 }
2054
2055 if (src == NULL) {
2056 int e;
2057 struct route_in6 ro;
2058
2059 /*
2060 * This case matches to multicasts, our anycast, or unicasts
2061 * that we do not own. Select a source address based on the
2062 * source address of the erroneous packet.
2063 */
2064 bzero(&ro, sizeof(ro));
2065 src = in6_selectsrc(&sa6_src, NULL, NULL, &ro, NULL, &e, NULL);
2066 if (ro.ro_rt)
2067 RTFREE(ro.ro_rt); /* XXX: we could use this */
2068 if (src == NULL) {
2069 nd6log((LOG_DEBUG,
2070 "icmp6_reflect: source can't be determined: "
2071 "dst=%s, error=%d\n",
2072 ip6_sprintf(&sa6_src.sin6_addr), e));
2073 goto bad;
2074 }
2075 }
2076
2077 ip6->ip6_src = *src;
2078
2079 ip6->ip6_flow = 0;
2080 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2081 ip6->ip6_vfc |= IPV6_VERSION;
2082 ip6->ip6_nxt = IPPROTO_ICMPV6;
2083 if (m->m_pkthdr.rcvif) {
2084 /* XXX: This may not be the outgoing interface */
2085 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2086 if (ip6->ip6_hlim < ip6_minhlim)
2087 ip6->ip6_hlim = ip6_minhlim;
2088 } else {
2089 ip6->ip6_hlim = ip6_defhlim;
2090 }
2091
2092 icmp6->icmp6_cksum = 0;
2093 icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2094 sizeof(struct ip6_hdr), plen);
2095
2096 /*
2097 * XXX option handling
2098 */
2099
2100 m->m_flags &= ~(M_BCAST|M_MCAST);
2101
2102 #ifdef COMPAT_RFC1885
2103 ip6_output(m, NULL, &icmp6_reflect_rt, 0, NULL, &outif, NULL);
2104 #else
2105 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2106 #endif
2107 if (outif)
2108 icmp6_ifoutstat_inc(outif, type, code);
2109
2110 return;
2111
2112 bad:
2113 m_freem(m);
2114 return;
2115 }
2116
2117 static void
icmp6_fasttimo_dispatch(netmsg_t nmsg)2118 icmp6_fasttimo_dispatch(netmsg_t nmsg)
2119 {
2120
2121 ASSERT_NETISR0;
2122
2123 /* Reply ASAP. */
2124 crit_enter();
2125 netisr_replymsg(&nmsg->base, 0);
2126 crit_exit();
2127
2128 mld6_fasttimeo();
2129
2130 callout_reset(&icmp6_fasttimo_ch, ICMP6_FASTTIMO, icmp6_fasttimo, NULL);
2131 }
2132
2133 static void
icmp6_fasttimo(void * dummy __unused)2134 icmp6_fasttimo(void *dummy __unused)
2135 {
2136 struct netmsg_base *nmsg = &icmp6_fasttimo_nmsg;
2137
2138 KKASSERT(mycpuid == 0);
2139
2140 crit_enter();
2141 if (nmsg->lmsg.ms_flags & MSGF_DONE)
2142 netisr_sendmsg_oncpu(nmsg);
2143 crit_exit();
2144 }
2145
2146 static const char *
icmp6_redirect_diag(struct in6_addr * src6,struct in6_addr * dst6,struct in6_addr * tgt6)2147 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2148 struct in6_addr *tgt6)
2149 {
2150 static char buf[1024];
2151 ksnprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2152 ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6));
2153 return buf;
2154 }
2155
2156 void
icmp6_redirect_input(struct mbuf * m,int off)2157 icmp6_redirect_input(struct mbuf *m, int off)
2158 {
2159 struct ifnet *ifp = m->m_pkthdr.rcvif;
2160 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2161 struct nd_redirect *nd_rd;
2162 int icmp6len = ntohs(ip6->ip6_plen);
2163 char *lladdr = NULL;
2164 int lladdrlen = 0;
2165 #if 0
2166 u_char *redirhdr = NULL;
2167 int redirhdrlen = 0;
2168 #endif
2169 struct rtentry *rt = NULL;
2170 int is_router;
2171 int is_onlink;
2172 struct in6_addr src6 = ip6->ip6_src;
2173 struct in6_addr redtgt6;
2174 struct in6_addr reddst6;
2175 union nd_opts ndopts;
2176
2177 if (!m || !ifp)
2178 return;
2179
2180 /* XXX if we are router, we don't update route by icmp6 redirect */
2181 if (ip6_forwarding)
2182 goto freeit;
2183 if (!icmp6_rediraccept)
2184 goto freeit;
2185
2186 #ifndef PULLDOWN_TEST
2187 IP6_EXTHDR_CHECK(m, off, icmp6len,);
2188 nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2189 #else
2190 IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2191 if (nd_rd == NULL) {
2192 icmp6stat.icp6s_tooshort++;
2193 return;
2194 }
2195 #endif
2196 redtgt6 = nd_rd->nd_rd_target;
2197 reddst6 = nd_rd->nd_rd_dst;
2198
2199 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2200 redtgt6.s6_addr16[1] = htons(ifp->if_index);
2201 if (IN6_IS_ADDR_LINKLOCAL(&reddst6))
2202 reddst6.s6_addr16[1] = htons(ifp->if_index);
2203
2204 /* validation */
2205 if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2206 nd6log((LOG_ERR,
2207 "ICMP6 redirect sent from %s rejected; "
2208 "must be from linklocal\n", ip6_sprintf(&src6)));
2209 goto bad;
2210 }
2211 if (ip6->ip6_hlim != 255) {
2212 nd6log((LOG_ERR,
2213 "ICMP6 redirect sent from %s rejected; "
2214 "hlim=%d (must be 255)\n",
2215 ip6_sprintf(&src6), ip6->ip6_hlim));
2216 goto bad;
2217 }
2218 {
2219 /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2220 struct sockaddr_in6 sin6;
2221 struct in6_addr *gw6;
2222
2223 bzero(&sin6, sizeof(sin6));
2224 sin6.sin6_family = AF_INET6;
2225 sin6.sin6_len = sizeof(struct sockaddr_in6);
2226 bcopy(&reddst6, &sin6.sin6_addr, sizeof reddst6);
2227 rt = rtpurelookup((struct sockaddr *)&sin6);
2228 if (rt != NULL) {
2229 if (rt->rt_gateway == NULL ||
2230 rt->rt_gateway->sa_family != AF_INET6) {
2231 nd6log((LOG_ERR,
2232 "ICMP6 redirect rejected; no route "
2233 "with inet6 gateway found for redirect dst: %s\n",
2234 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2235 --rt->rt_refcnt;
2236 goto bad;
2237 }
2238
2239 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2240 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2241 nd6log((LOG_ERR,
2242 "ICMP6 redirect rejected; "
2243 "not equal to gw-for-src=%s (must be same): "
2244 "%s\n",
2245 ip6_sprintf(gw6),
2246 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2247 --rt->rt_refcnt;
2248 goto bad;
2249 }
2250 } else {
2251 nd6log((LOG_ERR,
2252 "ICMP6 redirect rejected; "
2253 "no route found for redirect dst: %s\n",
2254 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2255 goto bad;
2256 }
2257 --rt->rt_refcnt;
2258 rt = NULL;
2259 }
2260 if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2261 nd6log((LOG_ERR,
2262 "ICMP6 redirect rejected; "
2263 "redirect dst must be unicast: %s\n",
2264 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2265 goto bad;
2266 }
2267
2268 is_router = is_onlink = 0;
2269 if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2270 is_router = 1; /* router case */
2271 if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2272 is_onlink = 1; /* on-link destination case */
2273 if (!is_router && !is_onlink) {
2274 nd6log((LOG_ERR,
2275 "ICMP6 redirect rejected; "
2276 "neither router case nor onlink case: %s\n",
2277 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2278 goto bad;
2279 }
2280 /* validation passed */
2281
2282 icmp6len -= sizeof(*nd_rd);
2283 nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2284 if (nd6_options(&ndopts) < 0) {
2285 nd6log((LOG_INFO, "icmp6_redirect_input: "
2286 "invalid ND option, rejected: %s\n",
2287 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2288 /* nd6_options have incremented stats */
2289 goto freeit;
2290 }
2291
2292 if (ndopts.nd_opts_tgt_lladdr) {
2293 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2294 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2295 }
2296
2297 #if 0
2298 if (ndopts.nd_opts_rh) {
2299 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2300 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2301 }
2302 #endif
2303
2304 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2305 nd6log((LOG_INFO,
2306 "icmp6_redirect_input: lladdrlen mismatch for %s "
2307 "(if %d, icmp6 packet %d): %s\n",
2308 ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2,
2309 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2310 goto bad;
2311 }
2312
2313 /* RFC 2461 8.3 */
2314 nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2315 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2316
2317 if (!is_onlink) { /* better router case. perform rtredirect. */
2318 /* perform rtredirect */
2319 struct sockaddr_in6 sdst;
2320 struct sockaddr_in6 sgw;
2321 struct sockaddr_in6 ssrc;
2322
2323 bzero(&sdst, sizeof(sdst));
2324 bzero(&sgw, sizeof(sgw));
2325 bzero(&ssrc, sizeof(ssrc));
2326 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2327 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2328 sizeof(struct sockaddr_in6);
2329 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2330 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2331 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2332 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2333 NULL, RTF_GATEWAY | RTF_HOST,
2334 (struct sockaddr *)&ssrc);
2335 }
2336 /* finally update cached route in each socket via kpfctlinput */
2337 {
2338 struct sockaddr_in6 sdst;
2339
2340 bzero(&sdst, sizeof(sdst));
2341 sdst.sin6_family = AF_INET6;
2342 sdst.sin6_len = sizeof(struct sockaddr_in6);
2343 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2344 kpfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2345 }
2346
2347 freeit:
2348 m_freem(m);
2349 return;
2350
2351 bad:
2352 icmp6stat.icp6s_badredirect++;
2353 m_freem(m);
2354 }
2355
2356 void
icmp6_redirect_output(struct mbuf * m0,struct rtentry * rt)2357 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2358 {
2359 struct ifnet *ifp; /* my outgoing interface */
2360 struct in6_addr *ifp_ll6;
2361 struct in6_addr *router_ll6;
2362 struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */
2363 struct mbuf *m = NULL; /* newly allocated one */
2364 struct ip6_hdr *ip6; /* m as struct ip6_hdr */
2365 struct nd_redirect *nd_rd;
2366 size_t maxlen;
2367 u_char *p;
2368 struct ifnet *outif = NULL;
2369 struct sockaddr_in6 src_sa;
2370
2371 icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2372
2373 /* if we are not router, we don't send icmp6 redirect */
2374 if (!ip6_forwarding)
2375 goto fail;
2376
2377 /* sanity check */
2378 if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2379 goto fail;
2380
2381 /*
2382 * Address check:
2383 * the source address must identify a neighbor, and
2384 * the destination address must not be a multicast address
2385 * [RFC 2461, sec 8.2]
2386 */
2387 sip6 = mtod(m0, struct ip6_hdr *);
2388 bzero(&src_sa, sizeof(src_sa));
2389 src_sa.sin6_family = AF_INET6;
2390 src_sa.sin6_len = sizeof(src_sa);
2391 src_sa.sin6_addr = sip6->ip6_src;
2392 /* we don't currently use sin6_scope_id, but eventually use it */
2393 if (in6_addr2zoneid(ifp, &sip6->ip6_src, &src_sa.sin6_scope_id))
2394 goto fail;
2395 if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2396 goto fail;
2397 if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2398 goto fail; /* what should we do here? */
2399
2400 /* rate limit */
2401 if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2402 goto fail;
2403
2404 /*
2405 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2406 * we almost always ask for an mbuf cluster for simplicity.
2407 * (MHLEN < IPV6_MMTU is almost always true)
2408 */
2409 #if IPV6_MMTU >= MCLBYTES
2410 # error assumption failed about IPV6_MMTU and MCLBYTES
2411 #endif
2412 m = m_getb(IPV6_MMTU, M_NOWAIT, MT_HEADER, M_PKTHDR);
2413 if (!m)
2414 goto fail;
2415 m->m_len = 0;
2416 maxlen = M_TRAILINGSPACE(m);
2417 maxlen = min(IPV6_MMTU, maxlen);
2418 /* just for safety */
2419 if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2420 ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2421 goto fail;
2422 }
2423
2424 {
2425 /* get ip6 linklocal address for ifp(my outgoing interface). */
2426 struct in6_ifaddr *ia;
2427 if ((ia = in6ifa_ifpforlinklocal(ifp,
2428 IN6_IFF_NOTREADY|
2429 IN6_IFF_ANYCAST)) == NULL)
2430 goto fail;
2431 ifp_ll6 = &ia->ia_addr.sin6_addr;
2432 }
2433
2434 /* get ip6 linklocal address for the router. */
2435 if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2436 struct sockaddr_in6 *sin6;
2437 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2438 router_ll6 = &sin6->sin6_addr;
2439 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2440 router_ll6 = NULL;
2441 } else
2442 router_ll6 = NULL;
2443
2444 /* ip6 */
2445 ip6 = mtod(m, struct ip6_hdr *);
2446 ip6->ip6_flow = 0;
2447 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2448 ip6->ip6_vfc |= IPV6_VERSION;
2449 /* ip6->ip6_plen will be set later */
2450 ip6->ip6_nxt = IPPROTO_ICMPV6;
2451 ip6->ip6_hlim = 255;
2452 /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2453 bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2454 bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2455
2456 /* ND Redirect */
2457 nd_rd = (struct nd_redirect *)(ip6 + 1);
2458 nd_rd->nd_rd_type = ND_REDIRECT;
2459 nd_rd->nd_rd_code = 0;
2460 nd_rd->nd_rd_reserved = 0;
2461 if (rt->rt_flags & RTF_GATEWAY) {
2462 /*
2463 * nd_rd->nd_rd_target must be a link-local address in
2464 * better router cases.
2465 */
2466 if (!router_ll6)
2467 goto fail;
2468 bcopy(router_ll6, &nd_rd->nd_rd_target,
2469 sizeof(nd_rd->nd_rd_target));
2470 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2471 sizeof(nd_rd->nd_rd_dst));
2472 } else {
2473 /* make sure redtgt == reddst */
2474 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2475 sizeof(nd_rd->nd_rd_target));
2476 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2477 sizeof(nd_rd->nd_rd_dst));
2478 }
2479
2480 p = (u_char *)(nd_rd + 1);
2481
2482 if (!router_ll6)
2483 goto nolladdropt;
2484
2485 {
2486 /* target lladdr option */
2487 struct rtentry *rt_router = NULL;
2488 int len;
2489 struct sockaddr_dl *sdl;
2490 struct nd_opt_hdr *nd_opt;
2491 char *lladdr;
2492
2493 rt_router = nd6_lookup(router_ll6, 0, ifp);
2494 if (!rt_router)
2495 goto nolladdropt;
2496 len = sizeof(*nd_opt) + ifp->if_addrlen;
2497 len = (len + 7) & ~7; /* round by 8 */
2498 /* safety check */
2499 if (len + (p - (u_char *)ip6) > maxlen)
2500 goto nolladdropt;
2501 if (!(rt_router->rt_flags & RTF_GATEWAY) &&
2502 (rt_router->rt_flags & RTF_LLINFO) &&
2503 (rt_router->rt_gateway->sa_family == AF_LINK) &&
2504 (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) &&
2505 sdl->sdl_alen) {
2506 nd_opt = (struct nd_opt_hdr *)p;
2507 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2508 nd_opt->nd_opt_len = len >> 3;
2509 lladdr = (char *)(nd_opt + 1);
2510 bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
2511 p += len;
2512 }
2513 }
2514 nolladdropt:;
2515
2516 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2517
2518 /* just to be safe */
2519 #ifdef M_DECRYPTED /*not openbsd*/
2520 if (m0->m_flags & M_DECRYPTED)
2521 goto noredhdropt;
2522 #endif
2523 if (p - (u_char *)ip6 > maxlen)
2524 goto noredhdropt;
2525
2526 {
2527 /* redirected header option */
2528 int len;
2529 struct nd_opt_rd_hdr *nd_opt_rh;
2530
2531 /*
2532 * compute the maximum size for icmp6 redirect header option.
2533 * XXX room for auth header?
2534 */
2535 len = maxlen - (p - (u_char *)ip6);
2536 len &= ~7;
2537
2538 /* This is just for simplicity. */
2539 if (m0->m_pkthdr.len != m0->m_len) {
2540 if (m0->m_next) {
2541 m_freem(m0->m_next);
2542 m0->m_next = NULL;
2543 }
2544 m0->m_pkthdr.len = m0->m_len;
2545 }
2546
2547 /*
2548 * Redirected header option spec (RFC2461 4.6.3) talks nothing
2549 * about padding/truncate rule for the original IP packet.
2550 * From the discussion on IPv6imp in Feb 1999, the consensus was:
2551 * - "attach as much as possible" is the goal
2552 * - pad if not aligned (original size can be guessed by original
2553 * ip6 header)
2554 * Following code adds the padding if it is simple enough,
2555 * and truncates if not.
2556 */
2557 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2558 panic("assumption failed in %s:%d", __FILE__, __LINE__);
2559
2560 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2561 /* not enough room, truncate */
2562 m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
2563 } else {
2564 /* enough room, pad or truncate */
2565 size_t extra;
2566
2567 extra = m0->m_pkthdr.len % 8;
2568 if (extra) {
2569 /* pad if easy enough, truncate if not */
2570 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2571 /* pad */
2572 m0->m_len += (8 - extra);
2573 m0->m_pkthdr.len += (8 - extra);
2574 } else {
2575 /* truncate */
2576 m0->m_pkthdr.len -= extra;
2577 m0->m_len -= extra;
2578 }
2579 }
2580 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2581 m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
2582 }
2583
2584 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2585 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2586 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2587 nd_opt_rh->nd_opt_rh_len = len >> 3;
2588 p += sizeof(*nd_opt_rh);
2589 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2590
2591 /* connect m0 to m */
2592 m->m_next = m0;
2593 m->m_pkthdr.len = m->m_len + m0->m_len;
2594 m0 = NULL;
2595 }
2596 noredhdropt:;
2597 if (m0 != NULL) {
2598 m_freem(m0);
2599 m0 = NULL;
2600 }
2601
2602 /* XXX: clear embedded link IDs in the inner header */
2603 in6_clearscope(&sip6->ip6_src);
2604 in6_clearscope(&sip6->ip6_dst);
2605 in6_clearscope(&nd_rd->nd_rd_target);
2606 in6_clearscope(&nd_rd->nd_rd_dst);
2607
2608 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2609
2610 nd_rd->nd_rd_cksum = 0;
2611 nd_rd->nd_rd_cksum
2612 = in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen));
2613
2614 /* send the packet to outside... */
2615 ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2616 if (outif) {
2617 icmp6_ifstat_inc(outif, ifs6_out_msg);
2618 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2619 }
2620 icmp6stat.icp6s_outhist[ND_REDIRECT]++;
2621
2622 return;
2623
2624 fail:
2625 if (m)
2626 m_freem(m);
2627 if (m0)
2628 m_freem(m0);
2629 }
2630
2631 #ifdef HAVE_NRL_INPCB
2632 #define in6pcb inpcb
2633 #define in6p_icmp6filt inp_icmp6filt
2634 #endif
2635 /*
2636 * ICMPv6 socket option processing.
2637 */
2638 void
icmp6_ctloutput(netmsg_t msg)2639 icmp6_ctloutput(netmsg_t msg)
2640 {
2641 struct socket *so = msg->ctloutput.base.nm_so;
2642 struct sockopt *sopt = msg->ctloutput.nm_sopt;
2643 int error = 0;
2644 int optlen;
2645 struct inpcb *inp = so->so_pcb;
2646 int level, op, optname;
2647
2648 if (sopt) {
2649 level = sopt->sopt_level;
2650 op = sopt->sopt_dir;
2651 optname = sopt->sopt_name;
2652 optlen = sopt->sopt_valsize;
2653 } else
2654 level = op = optname = optlen = 0;
2655
2656 if (level != IPPROTO_ICMPV6) {
2657 error = EINVAL;
2658 goto out;
2659 }
2660
2661 switch (op) {
2662 case PRCO_SETOPT:
2663 switch (optname) {
2664 case ICMP6_FILTER:
2665 {
2666 if (optlen != sizeof(struct icmp6_filter)) {
2667 error = EMSGSIZE;
2668 break;
2669 }
2670 if (inp->in6p_icmp6filt == NULL) {
2671 error = EINVAL;
2672 break;
2673 }
2674 error = soopt_to_kbuf(sopt, inp->in6p_icmp6filt, optlen,
2675 optlen);
2676 break;
2677 }
2678
2679 default:
2680 error = ENOPROTOOPT;
2681 break;
2682 }
2683 break;
2684
2685 case PRCO_GETOPT:
2686 switch (optname) {
2687 case ICMP6_FILTER:
2688 {
2689 if (inp->in6p_icmp6filt == NULL) {
2690 error = EINVAL;
2691 break;
2692 }
2693 soopt_from_kbuf(sopt, inp->in6p_icmp6filt,
2694 sizeof(struct icmp6_filter));
2695 break;
2696 }
2697
2698 default:
2699 error = ENOPROTOOPT;
2700 break;
2701 }
2702 break;
2703 }
2704 out:
2705 lwkt_replymsg(&msg->ctloutput.base.lmsg, error);
2706 }
2707 #ifdef HAVE_NRL_INPCB
2708 #undef in6pcb
2709 #undef in6p_icmp6filt
2710 #endif
2711
2712 #ifndef HAVE_PPSRATECHECK
2713 #ifndef timersub
2714 #define timersub(tvp, uvp, vvp) \
2715 do { \
2716 (vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec; \
2717 (vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec; \
2718 if ((vvp)->tv_usec < 0) { \
2719 (vvp)->tv_sec--; \
2720 (vvp)->tv_usec += 1000000; \
2721 } \
2722 } while (0)
2723 #endif
2724
2725 /*
2726 * ppsratecheck(): packets (or events) per second limitation.
2727 */
2728 static int
ppsratecheck(struct timeval * lasttime,int * curpps,int maxpps)2729 ppsratecheck(struct timeval *lasttime, int *curpps,
2730 int maxpps) /* maximum pps allowed */
2731 {
2732 struct timeval tv, delta;
2733 int rv;
2734
2735 microtime(&tv);
2736
2737 timersub(&tv, lasttime, &delta);
2738
2739 /*
2740 * Check for 0,0 so that the message will be seen at least once.
2741 * If more than one second has passed since the last update of
2742 * lasttime, reset the counter.
2743 *
2744 * We do increment *curpps even in *curpps < maxpps case, as some may
2745 * try to use *curpps for stat purposes as well.
2746 */
2747 if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) ||
2748 delta.tv_sec >= 1) {
2749 *lasttime = tv;
2750 *curpps = 0;
2751 rv = 1;
2752 } else if (maxpps < 0)
2753 rv = 1;
2754 else if (*curpps < maxpps)
2755 rv = 1;
2756 else
2757 rv = 0;
2758
2759 #if 1 /* DIAGNOSTIC? */
2760 /* be careful about wrap-around */
2761 if (*curpps + 1 > *curpps)
2762 *curpps = *curpps + 1;
2763 #else
2764 /*
2765 * assume that there's not too many calls to this function.
2766 * not sure if the assumption holds, as it depends on *caller's*
2767 * behavior, not the behavior of this function.
2768 * IMHO it is wrong to make assumption on the caller's behavior,
2769 * so the above #if is #if 1, not #ifdef DIAGNOSTIC.
2770 */
2771 *curpps = *curpps + 1;
2772 #endif
2773
2774 return (rv);
2775 }
2776 #endif
2777
2778 /*
2779 * Perform rate limit check.
2780 * Returns 0 if it is okay to send the icmp6 packet.
2781 * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2782 * limitation.
2783 *
2784 * XXX per-destination/type check necessary?
2785 */
2786 static int
icmp6_ratelimit(const struct in6_addr * dst,const int type,const int code)2787 icmp6_ratelimit(const struct in6_addr *dst, /* not used at this moment */
2788 const int type, /* not used at this moment */
2789 const int code) /* not used at this moment */
2790 {
2791 int ret;
2792
2793 ret = 0; /* okay to send */
2794
2795 /* PPS limit */
2796 if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
2797 icmp6errppslim)) {
2798 /* The packet is subject to rate limit */
2799 ret++;
2800 }
2801
2802 return ret;
2803 }
2804