1 /* $FreeBSD$ */
2 /* $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 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 * 4. 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_input.c 8.2 (Berkeley) 1/4/94
62 */
63
64 #include "opt_inet.h"
65 #include "opt_inet6.h"
66 #include "opt_ipsec.h"
67
68 #include <sys/param.h>
69 #include <sys/systm.h>
70 #include <sys/malloc.h>
71 #include <sys/mbuf.h>
72 #include <sys/proc.h>
73 #include <sys/domain.h>
74 #include <sys/protosw.h>
75 #include <sys/socket.h>
76 #include <sys/socketvar.h>
77 #include <sys/errno.h>
78 #include <sys/time.h>
79 #include <sys/kernel.h>
80 #include <sys/syslog.h>
81
82 #include <net/if.h>
83 #include <net/if_types.h>
84 #include <net/if_dl.h>
85 #include <net/route.h>
86 #include <net/netisr.h>
87 #include <net/pfil.h>
88
89 #include <netinet/in.h>
90 #include <netinet/in_systm.h>
91 #ifdef INET
92 #include <netinet/ip.h>
93 #include <netinet/ip_icmp.h>
94 #endif /* INET */
95 #include <netinet/ip6.h>
96 #include <netinet6/in6_var.h>
97 #include <netinet6/ip6_var.h>
98 #include <netinet/in_pcb.h>
99 #include <netinet/icmp6.h>
100 #include <netinet6/scope6_var.h>
101 #include <netinet6/in6_ifattach.h>
102 #include <netinet6/nd6.h>
103
104 #ifdef IPSEC
105 #include <netipsec/ipsec.h>
106 #include <netinet6/ip6_ipsec.h>
107 #include <netipsec/ipsec6.h>
108 #endif /* IPSEC */
109
110 #include <netinet6/ip6protosw.h>
111
112 extern struct domain inet6domain;
113
114 u_char ip6_protox[IPPROTO_MAX];
115 static struct ifqueue ip6intrq;
116 static int ip6qmaxlen = IFQ_MAXLEN;
117 struct in6_ifaddr *in6_ifaddr;
118
119 extern struct callout in6_tmpaddrtimer_ch;
120
121 int ip6_forward_srcrt; /* XXX */
122 int ip6_sourcecheck; /* XXX */
123 int ip6_sourcecheck_interval; /* XXX */
124
125 int ip6_ours_check_algorithm;
126
127 struct pfil_head inet6_pfil_hook;
128
129 struct ip6stat ip6stat;
130
131 static void ip6_init2 __P((void *));
132 static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *));
133 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *));
134 #ifdef PULLDOWN_TEST
135 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int));
136 #endif
137
138 /*
139 * IP6 initialization: fill in IP6 protocol switch table.
140 * All protocols not implemented in kernel go to raw IP6 protocol handler.
141 */
142 void
143 ip6_init(void)
144 {
145 struct ip6protosw *pr;
146 int i;
147
148 #ifdef DIAGNOSTIC
149 if (sizeof(struct protosw) != sizeof(struct ip6protosw))
150 panic("sizeof(protosw) != sizeof(ip6protosw)");
151 #endif
152 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
153 if (pr == 0)
154 panic("ip6_init");
155
156 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
157 for (i = 0; i < IPPROTO_MAX; i++)
158 ip6_protox[i] = pr - inet6sw;
159 /*
160 * Cycle through IP protocols and put them into the appropriate place
161 * in ip6_protox[].
162 */
163 for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
164 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++)
165 if (pr->pr_domain->dom_family == PF_INET6 &&
166 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
167 /* Be careful to only index valid IP protocols. */
168 if (pr->pr_protocol < IPPROTO_MAX)
169 ip6_protox[pr->pr_protocol] = pr - inet6sw;
170 }
171
172 /* Initialize packet filter hooks. */
173 inet6_pfil_hook.ph_type = PFIL_TYPE_AF;
174 inet6_pfil_hook.ph_af = AF_INET6;
175 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0)
176 printf("%s: WARNING: unable to register pfil hook, "
177 "error %d\n", __func__, i);
178
179 ip6intrq.ifq_maxlen = ip6qmaxlen;
180 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF);
181 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0);
182 scope6_init();
183 addrsel_policy_init();
184 nd6_init();
185 frag6_init();
186 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR;
187 }
188
189 static void
190 ip6_init2(void *dummy)
191 {
192
193 /* nd6_timer_init */
194 callout_init(&nd6_timer_ch, 0);
195 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL);
196
197 /* timer for regeneranation of temporary addresses randomize ID */
198 callout_init(&in6_tmpaddrtimer_ch, 0);
199 callout_reset(&in6_tmpaddrtimer_ch,
200 (ip6_temp_preferred_lifetime - ip6_desync_factor -
201 ip6_temp_regen_advance) * hz,
202 in6_tmpaddrtimer, NULL);
203 }
204
205 /* cheat */
206 /* This must be after route_init(), which is now SI_ORDER_THIRD */
207 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL);
208
209 extern struct route_in6 ip6_forward_rt;
210
211 void
212 ip6_input(struct mbuf *m)
213 {
214 struct ip6_hdr *ip6;
215 int off = sizeof(struct ip6_hdr), nest;
216 u_int32_t plen;
217 u_int32_t rtalert = ~0;
218 int nxt, ours = 0;
219 struct ifnet *deliverifp = NULL;
220 struct in6_addr odst;
221 int srcrt = 0;
222
223 GIANT_REQUIRED; /* XXX for now */
224
225 #ifdef IPSEC
226 /*
227 * should the inner packet be considered authentic?
228 * see comment in ah4_input().
229 * NB: m cannot be NULL when passed to the input routine
230 */
231
232 m->m_flags &= ~M_AUTHIPHDR;
233 m->m_flags &= ~M_AUTHIPDGM;
234
235 #endif /* IPSEC */
236
237 /*
238 * make sure we don't have onion peering information into m_tag.
239 */
240 ip6_delaux(m);
241
242 /*
243 * mbuf statistics
244 */
245 if (m->m_flags & M_EXT) {
246 if (m->m_next)
247 ip6stat.ip6s_mext2m++;
248 else
249 ip6stat.ip6s_mext1++;
250 } else {
251 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0]))
252 if (m->m_next) {
253 if (m->m_flags & M_LOOP) {
254 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */
255 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX)
256 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++;
257 else
258 ip6stat.ip6s_m2m[0]++;
259 } else
260 ip6stat.ip6s_m1++;
261 #undef M2MMAX
262 }
263
264 /* drop the packet if IPv6 operation is disabled on the IF */
265 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) {
266 m_freem(m);
267 return;
268 }
269
270 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
271 ip6stat.ip6s_total++;
272
273 #ifndef PULLDOWN_TEST
274 /*
275 * L2 bridge code and some other code can return mbuf chain
276 * that does not conform to KAME requirement. too bad.
277 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram?
278 */
279 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) {
280 struct mbuf *n;
281
282 MGETHDR(n, M_DONTWAIT, MT_HEADER);
283 if (n)
284 M_MOVE_PKTHDR(n, m);
285 if (n && n->m_pkthdr.len > MHLEN) {
286 MCLGET(n, M_DONTWAIT);
287 if ((n->m_flags & M_EXT) == 0) {
288 m_freem(n);
289 n = NULL;
290 }
291 }
292 if (n == NULL) {
293 m_freem(m);
294 return; /* ENOBUFS */
295 }
296
297 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
298 n->m_len = n->m_pkthdr.len;
299 m_freem(m);
300 m = n;
301 }
302 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */);
303 #endif
304
305 if (m->m_len < sizeof(struct ip6_hdr)) {
306 struct ifnet *inifp;
307 inifp = m->m_pkthdr.rcvif;
308 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
309 ip6stat.ip6s_toosmall++;
310 in6_ifstat_inc(inifp, ifs6_in_hdrerr);
311 return;
312 }
313 }
314
315 ip6 = mtod(m, struct ip6_hdr *);
316
317 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
318 ip6stat.ip6s_badvers++;
319 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
320 goto bad;
321 }
322
323 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++;
324
325 /*
326 * Check against address spoofing/corruption.
327 */
328 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
329 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
330 /*
331 * XXX: "badscope" is not very suitable for a multicast source.
332 */
333 ip6stat.ip6s_badscope++;
334 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
335 goto bad;
336 }
337 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) &&
338 !(m->m_flags & M_LOOP)) {
339 /*
340 * In this case, the packet should come from the loopback
341 * interface. However, we cannot just check the if_flags,
342 * because ip6_mloopback() passes the "actual" interface
343 * as the outgoing/incoming interface.
344 */
345 ip6stat.ip6s_badscope++;
346 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
347 goto bad;
348 }
349
350 #ifdef ALTQ
351 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) {
352 /* packet is dropped by traffic conditioner */
353 return;
354 }
355 #endif
356 /*
357 * The following check is not documented in specs. A malicious
358 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
359 * and bypass security checks (act as if it was from 127.0.0.1 by using
360 * IPv6 src ::ffff:127.0.0.1). Be cautious.
361 *
362 * This check chokes if we are in an SIIT cloud. As none of BSDs
363 * support IPv4-less kernel compilation, we cannot support SIIT
364 * environment at all. So, it makes more sense for us to reject any
365 * malicious packets for non-SIIT environment, than try to do a
366 * partial support for SIIT environment.
367 */
368 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
369 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
370 ip6stat.ip6s_badscope++;
371 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
372 goto bad;
373 }
374 #if 0
375 /*
376 * Reject packets with IPv4 compatible addresses (auto tunnel).
377 *
378 * The code forbids auto tunnel relay case in RFC1933 (the check is
379 * stronger than RFC1933). We may want to re-enable it if mech-xx
380 * is revised to forbid relaying case.
381 */
382 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
383 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
384 ip6stat.ip6s_badscope++;
385 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
386 goto bad;
387 }
388 #endif
389
390 /*
391 * Run through list of hooks for input packets.
392 *
393 * NB: Beware of the destination address changing
394 * (e.g. by NAT rewriting). When this happens,
395 * tell ip6_forward to do the right thing.
396 */
397 odst = ip6->ip6_dst;
398
399 /* Jump over all PFIL processing if hooks are not active. */
400 if (!PFIL_HOOKED(&inet6_pfil_hook))
401 goto passin;
402
403 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL))
404 return;
405 if (m == NULL) /* consumed by filter */
406 return;
407 ip6 = mtod(m, struct ip6_hdr *);
408 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
409
410 passin:
411 /*
412 * Disambiguate address scope zones (if there is ambiguity).
413 * We first make sure that the original source or destination address
414 * is not in our internal form for scoped addresses. Such addresses
415 * are not necessarily invalid spec-wise, but we cannot accept them due
416 * to the usage conflict.
417 * in6_setscope() then also checks and rejects the cases where src or
418 * dst are the loopback address and the receiving interface
419 * is not loopback.
420 */
421 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) {
422 ip6stat.ip6s_badscope++; /* XXX */
423 goto bad;
424 }
425 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) ||
426 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) {
427 ip6stat.ip6s_badscope++;
428 goto bad;
429 }
430
431 /*
432 * Multicast check
433 */
434 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
435 struct in6_multi *in6m = 0;
436
437 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
438 /*
439 * See if we belong to the destination multicast group on the
440 * arrival interface.
441 */
442 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m);
443 if (in6m)
444 ours = 1;
445 else if (!ip6_mrouter) {
446 ip6stat.ip6s_notmember++;
447 ip6stat.ip6s_cantforward++;
448 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
449 goto bad;
450 }
451 deliverifp = m->m_pkthdr.rcvif;
452 goto hbhcheck;
453 }
454
455 /*
456 * Unicast check
457 */
458 if (ip6_forward_rt.ro_rt != NULL &&
459 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 &&
460 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
461 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr))
462 ip6stat.ip6s_forward_cachehit++;
463 else {
464 struct sockaddr_in6 *dst6;
465
466 if (ip6_forward_rt.ro_rt) {
467 /* route is down or destination is different */
468 ip6stat.ip6s_forward_cachemiss++;
469 RTFREE(ip6_forward_rt.ro_rt);
470 ip6_forward_rt.ro_rt = 0;
471 }
472
473 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6));
474 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst;
475 dst6->sin6_len = sizeof(struct sockaddr_in6);
476 dst6->sin6_family = AF_INET6;
477 dst6->sin6_addr = ip6->ip6_dst;
478
479 rtalloc((struct route *)&ip6_forward_rt);
480 }
481
482 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))
483
484 /*
485 * Accept the packet if the forwarding interface to the destination
486 * according to the routing table is the loopback interface,
487 * unless the associated route has a gateway.
488 * Note that this approach causes to accept a packet if there is a
489 * route to the loopback interface for the destination of the packet.
490 * But we think it's even useful in some situations, e.g. when using
491 * a special daemon which wants to intercept the packet.
492 *
493 * XXX: some OSes automatically make a cloned route for the destination
494 * of an outgoing packet. If the outgoing interface of the packet
495 * is a loopback one, the kernel would consider the packet to be
496 * accepted, even if we have no such address assinged on the interface.
497 * We check the cloned flag of the route entry to reject such cases,
498 * assuming that route entries for our own addresses are not made by
499 * cloning (it should be true because in6_addloop explicitly installs
500 * the host route). However, we might have to do an explicit check
501 * while it would be less efficient. Or, should we rather install a
502 * reject route for such a case?
503 */
504 if (ip6_forward_rt.ro_rt &&
505 (ip6_forward_rt.ro_rt->rt_flags &
506 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
507 #ifdef RTF_WASCLONED
508 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) &&
509 #endif
510 #ifdef RTF_CLONED
511 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) &&
512 #endif
513 #if 0
514 /*
515 * The check below is redundant since the comparison of
516 * the destination and the key of the rtentry has
517 * already done through looking up the routing table.
518 */
519 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
520 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr)
521 #endif
522 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) {
523 struct in6_ifaddr *ia6 =
524 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa;
525
526 /*
527 * record address information into m_tag.
528 */
529 (void)ip6_setdstifaddr(m, ia6);
530
531 /*
532 * packets to a tentative, duplicated, or somehow invalid
533 * address must not be accepted.
534 */
535 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
536 /* this address is ready */
537 ours = 1;
538 deliverifp = ia6->ia_ifp; /* correct? */
539 /* Count the packet in the ip address stats */
540 ia6->ia_ifa.if_ipackets++;
541 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
542 goto hbhcheck;
543 } else {
544 char ip6bufs[INET6_ADDRSTRLEN];
545 char ip6bufd[INET6_ADDRSTRLEN];
546 /* address is not ready, so discard the packet. */
547 nd6log((LOG_INFO,
548 "ip6_input: packet to an unready address %s->%s\n",
549 ip6_sprintf(ip6bufs, &ip6->ip6_src),
550 ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
551
552 goto bad;
553 }
554 }
555
556 /*
557 * FAITH (Firewall Aided Internet Translator)
558 */
559 if (ip6_keepfaith) {
560 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp
561 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) {
562 /* XXX do we need more sanity checks? */
563 ours = 1;
564 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */
565 goto hbhcheck;
566 }
567 }
568
569 /*
570 * Now there is no reason to process the packet if it's not our own
571 * and we're not a router.
572 */
573 if (!ip6_forwarding) {
574 ip6stat.ip6s_cantforward++;
575 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
576 goto bad;
577 }
578
579 hbhcheck:
580 /*
581 * record address information into m_tag, if we don't have one yet.
582 * note that we are unable to record it, if the address is not listed
583 * as our interface address (e.g. multicast addresses, addresses
584 * within FAITH prefixes and such).
585 */
586 if (deliverifp && !ip6_getdstifaddr(m)) {
587 struct in6_ifaddr *ia6;
588
589 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
590 if (ia6) {
591 if (!ip6_setdstifaddr(m, ia6)) {
592 /*
593 * XXX maybe we should drop the packet here,
594 * as we could not provide enough information
595 * to the upper layers.
596 */
597 }
598 }
599 }
600
601 /*
602 * Process Hop-by-Hop options header if it's contained.
603 * m may be modified in ip6_hopopts_input().
604 * If a JumboPayload option is included, plen will also be modified.
605 */
606 plen = (u_int32_t)ntohs(ip6->ip6_plen);
607 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
608 struct ip6_hbh *hbh;
609
610 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) {
611 #if 0 /*touches NULL pointer*/
612 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
613 #endif
614 return; /* m have already been freed */
615 }
616
617 /* adjust pointer */
618 ip6 = mtod(m, struct ip6_hdr *);
619
620 /*
621 * if the payload length field is 0 and the next header field
622 * indicates Hop-by-Hop Options header, then a Jumbo Payload
623 * option MUST be included.
624 */
625 if (ip6->ip6_plen == 0 && plen == 0) {
626 /*
627 * Note that if a valid jumbo payload option is
628 * contained, ip6_hopopts_input() must set a valid
629 * (non-zero) payload length to the variable plen.
630 */
631 ip6stat.ip6s_badoptions++;
632 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
633 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
634 icmp6_error(m, ICMP6_PARAM_PROB,
635 ICMP6_PARAMPROB_HEADER,
636 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
637 return;
638 }
639 #ifndef PULLDOWN_TEST
640 /* ip6_hopopts_input() ensures that mbuf is contiguous */
641 hbh = (struct ip6_hbh *)(ip6 + 1);
642 #else
643 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
644 sizeof(struct ip6_hbh));
645 if (hbh == NULL) {
646 ip6stat.ip6s_tooshort++;
647 return;
648 }
649 #endif
650 nxt = hbh->ip6h_nxt;
651
652 /*
653 * If we are acting as a router and the packet contains a
654 * router alert option, see if we know the option value.
655 * Currently, we only support the option value for MLD, in which
656 * case we should pass the packet to the multicast routing
657 * daemon.
658 */
659 if (rtalert != ~0 && ip6_forwarding) {
660 switch (rtalert) {
661 case IP6OPT_RTALERT_MLD:
662 ours = 1;
663 break;
664 default:
665 /*
666 * RFC2711 requires unrecognized values must be
667 * silently ignored.
668 */
669 break;
670 }
671 }
672 } else
673 nxt = ip6->ip6_nxt;
674
675 /*
676 * Check that the amount of data in the buffers
677 * is as at least much as the IPv6 header would have us expect.
678 * Trim mbufs if longer than we expect.
679 * Drop packet if shorter than we expect.
680 */
681 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
682 ip6stat.ip6s_tooshort++;
683 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
684 goto bad;
685 }
686 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
687 if (m->m_len == m->m_pkthdr.len) {
688 m->m_len = sizeof(struct ip6_hdr) + plen;
689 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
690 } else
691 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
692 }
693
694 /*
695 * Forward if desirable.
696 */
697 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
698 /*
699 * If we are acting as a multicast router, all
700 * incoming multicast packets are passed to the
701 * kernel-level multicast forwarding function.
702 * The packet is returned (relatively) intact; if
703 * ip6_mforward() returns a non-zero value, the packet
704 * must be discarded, else it may be accepted below.
705 */
706 if (ip6_mrouter && ip6_mforward &&
707 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
708 ip6stat.ip6s_cantforward++;
709 m_freem(m);
710 return;
711 }
712 if (!ours) {
713 m_freem(m);
714 return;
715 }
716 } else if (!ours) {
717 ip6_forward(m, srcrt);
718 return;
719 }
720
721 ip6 = mtod(m, struct ip6_hdr *);
722
723 /*
724 * Malicious party may be able to use IPv4 mapped addr to confuse
725 * tcp/udp stack and bypass security checks (act as if it was from
726 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious.
727 *
728 * For SIIT end node behavior, you may want to disable the check.
729 * However, you will become vulnerable to attacks using IPv4 mapped
730 * source.
731 */
732 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
733 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
734 ip6stat.ip6s_badscope++;
735 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
736 goto bad;
737 }
738
739 /*
740 * Tell launch routine the next header
741 */
742 ip6stat.ip6s_delivered++;
743 in6_ifstat_inc(deliverifp, ifs6_in_deliver);
744 nest = 0;
745
746 while (nxt != IPPROTO_DONE) {
747 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
748 ip6stat.ip6s_toomanyhdr++;
749 goto bad;
750 }
751
752 /*
753 * protection against faulty packet - there should be
754 * more sanity checks in header chain processing.
755 */
756 if (m->m_pkthdr.len < off) {
757 ip6stat.ip6s_tooshort++;
758 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
759 goto bad;
760 }
761
762 #ifdef IPSEC
763 /*
764 * enforce IPsec policy checking if we are seeing last header.
765 * note that we do not visit this with protocols with pcb layer
766 * code - like udp/tcp/raw ip.
767 */
768 if (ip6_ipsec_input(m, nxt))
769 goto bad;
770 #endif /* IPSEC */
771 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
772 }
773 return;
774 bad:
775 m_freem(m);
776 }
777
778 /*
779 * set/grab in6_ifaddr correspond to IPv6 destination address.
780 * XXX backward compatibility wrapper
781 */
782 static struct ip6aux *
783 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6)
784 {
785 struct ip6aux *ip6a;
786
787 ip6a = ip6_addaux(m);
788 if (ip6a)
789 ip6a->ip6a_dstia6 = ia6;
790 return ip6a; /* NULL if failed to set */
791 }
792
793 struct in6_ifaddr *
794 ip6_getdstifaddr(struct mbuf *m)
795 {
796 struct ip6aux *ip6a;
797
798 ip6a = ip6_findaux(m);
799 if (ip6a)
800 return ip6a->ip6a_dstia6;
801 else
802 return NULL;
803 }
804
805 /*
806 * Hop-by-Hop options header processing. If a valid jumbo payload option is
807 * included, the real payload length will be stored in plenp.
808 *
809 * rtalertp - XXX: should be stored more smart way
810 */
811 static int
812 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp,
813 struct mbuf **mp, int *offp)
814 {
815 struct mbuf *m = *mp;
816 int off = *offp, hbhlen;
817 struct ip6_hbh *hbh;
818 u_int8_t *opt;
819
820 /* validation of the length of the header */
821 #ifndef PULLDOWN_TEST
822 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1);
823 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
824 hbhlen = (hbh->ip6h_len + 1) << 3;
825
826 IP6_EXTHDR_CHECK(m, off, hbhlen, -1);
827 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
828 #else
829 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
830 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
831 if (hbh == NULL) {
832 ip6stat.ip6s_tooshort++;
833 return -1;
834 }
835 hbhlen = (hbh->ip6h_len + 1) << 3;
836 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
837 hbhlen);
838 if (hbh == NULL) {
839 ip6stat.ip6s_tooshort++;
840 return -1;
841 }
842 #endif
843 off += hbhlen;
844 hbhlen -= sizeof(struct ip6_hbh);
845 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh);
846
847 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
848 hbhlen, rtalertp, plenp) < 0)
849 return (-1);
850
851 *offp = off;
852 *mp = m;
853 return (0);
854 }
855
856 /*
857 * Search header for all Hop-by-hop options and process each option.
858 * This function is separate from ip6_hopopts_input() in order to
859 * handle a case where the sending node itself process its hop-by-hop
860 * options header. In such a case, the function is called from ip6_output().
861 *
862 * The function assumes that hbh header is located right after the IPv6 header
863 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
864 * opthead + hbhlen is located in continuous memory region.
865 */
866 int
867 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen,
868 u_int32_t *rtalertp, u_int32_t *plenp)
869 {
870 struct ip6_hdr *ip6;
871 int optlen = 0;
872 u_int8_t *opt = opthead;
873 u_int16_t rtalert_val;
874 u_int32_t jumboplen;
875 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
876
877 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
878 switch (*opt) {
879 case IP6OPT_PAD1:
880 optlen = 1;
881 break;
882 case IP6OPT_PADN:
883 if (hbhlen < IP6OPT_MINLEN) {
884 ip6stat.ip6s_toosmall++;
885 goto bad;
886 }
887 optlen = *(opt + 1) + 2;
888 break;
889 case IP6OPT_ROUTER_ALERT:
890 /* XXX may need check for alignment */
891 if (hbhlen < IP6OPT_RTALERT_LEN) {
892 ip6stat.ip6s_toosmall++;
893 goto bad;
894 }
895 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
896 /* XXX stat */
897 icmp6_error(m, ICMP6_PARAM_PROB,
898 ICMP6_PARAMPROB_HEADER,
899 erroff + opt + 1 - opthead);
900 return (-1);
901 }
902 optlen = IP6OPT_RTALERT_LEN;
903 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
904 *rtalertp = ntohs(rtalert_val);
905 break;
906 case IP6OPT_JUMBO:
907 /* XXX may need check for alignment */
908 if (hbhlen < IP6OPT_JUMBO_LEN) {
909 ip6stat.ip6s_toosmall++;
910 goto bad;
911 }
912 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
913 /* XXX stat */
914 icmp6_error(m, ICMP6_PARAM_PROB,
915 ICMP6_PARAMPROB_HEADER,
916 erroff + opt + 1 - opthead);
917 return (-1);
918 }
919 optlen = IP6OPT_JUMBO_LEN;
920
921 /*
922 * IPv6 packets that have non 0 payload length
923 * must not contain a jumbo payload option.
924 */
925 ip6 = mtod(m, struct ip6_hdr *);
926 if (ip6->ip6_plen) {
927 ip6stat.ip6s_badoptions++;
928 icmp6_error(m, ICMP6_PARAM_PROB,
929 ICMP6_PARAMPROB_HEADER,
930 erroff + opt - opthead);
931 return (-1);
932 }
933
934 /*
935 * We may see jumbolen in unaligned location, so
936 * we'd need to perform bcopy().
937 */
938 bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
939 jumboplen = (u_int32_t)htonl(jumboplen);
940
941 #if 1
942 /*
943 * if there are multiple jumbo payload options,
944 * *plenp will be non-zero and the packet will be
945 * rejected.
946 * the behavior may need some debate in ipngwg -
947 * multiple options does not make sense, however,
948 * there's no explicit mention in specification.
949 */
950 if (*plenp != 0) {
951 ip6stat.ip6s_badoptions++;
952 icmp6_error(m, ICMP6_PARAM_PROB,
953 ICMP6_PARAMPROB_HEADER,
954 erroff + opt + 2 - opthead);
955 return (-1);
956 }
957 #endif
958
959 /*
960 * jumbo payload length must be larger than 65535.
961 */
962 if (jumboplen <= IPV6_MAXPACKET) {
963 ip6stat.ip6s_badoptions++;
964 icmp6_error(m, ICMP6_PARAM_PROB,
965 ICMP6_PARAMPROB_HEADER,
966 erroff + opt + 2 - opthead);
967 return (-1);
968 }
969 *plenp = jumboplen;
970
971 break;
972 default: /* unknown option */
973 if (hbhlen < IP6OPT_MINLEN) {
974 ip6stat.ip6s_toosmall++;
975 goto bad;
976 }
977 optlen = ip6_unknown_opt(opt, m,
978 erroff + opt - opthead);
979 if (optlen == -1)
980 return (-1);
981 optlen += 2;
982 break;
983 }
984 }
985
986 return (0);
987
988 bad:
989 m_freem(m);
990 return (-1);
991 }
992
993 /*
994 * Unknown option processing.
995 * The third argument `off' is the offset from the IPv6 header to the option,
996 * which is necessary if the IPv6 header the and option header and IPv6 header
997 * is not continuous in order to return an ICMPv6 error.
998 */
999 int
1000 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off)
1001 {
1002 struct ip6_hdr *ip6;
1003
1004 switch (IP6OPT_TYPE(*optp)) {
1005 case IP6OPT_TYPE_SKIP: /* ignore the option */
1006 return ((int)*(optp + 1));
1007 case IP6OPT_TYPE_DISCARD: /* silently discard */
1008 m_freem(m);
1009 return (-1);
1010 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
1011 ip6stat.ip6s_badoptions++;
1012 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
1013 return (-1);
1014 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
1015 ip6stat.ip6s_badoptions++;
1016 ip6 = mtod(m, struct ip6_hdr *);
1017 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
1018 (m->m_flags & (M_BCAST|M_MCAST)))
1019 m_freem(m);
1020 else
1021 icmp6_error(m, ICMP6_PARAM_PROB,
1022 ICMP6_PARAMPROB_OPTION, off);
1023 return (-1);
1024 }
1025
1026 m_freem(m); /* XXX: NOTREACHED */
1027 return (-1);
1028 }
1029
1030 /*
1031 * Create the "control" list for this pcb.
1032 * The function will not modify mbuf chain at all.
1033 *
1034 * with KAME mbuf chain restriction:
1035 * The routine will be called from upper layer handlers like tcp6_input().
1036 * Thus the routine assumes that the caller (tcp6_input) have already
1037 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the
1038 * very first mbuf on the mbuf chain.
1039 */
1040 void
1041 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp)
1042 {
1043 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y))
1044 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1045
1046 #ifdef SO_TIMESTAMP
1047 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) {
1048 struct timeval tv;
1049
1050 microtime(&tv);
1051 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1052 SCM_TIMESTAMP, SOL_SOCKET);
1053 if (*mp)
1054 mp = &(*mp)->m_next;
1055 }
1056 #endif
1057
1058 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION)
1059 return;
1060
1061 /* RFC 2292 sec. 5 */
1062 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) {
1063 struct in6_pktinfo pi6;
1064
1065 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
1066 in6_clearscope(&pi6.ipi6_addr); /* XXX */
1067 pi6.ipi6_ifindex =
1068 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0;
1069
1070 *mp = sbcreatecontrol((caddr_t) &pi6,
1071 sizeof(struct in6_pktinfo),
1072 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6);
1073 if (*mp)
1074 mp = &(*mp)->m_next;
1075 }
1076
1077 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) {
1078 int hlim = ip6->ip6_hlim & 0xff;
1079
1080 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int),
1081 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6);
1082 if (*mp)
1083 mp = &(*mp)->m_next;
1084 }
1085
1086 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) {
1087 u_int32_t flowinfo;
1088 int tclass;
1089
1090 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
1091 flowinfo >>= 20;
1092
1093 tclass = flowinfo & 0xff;
1094 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass),
1095 IPV6_TCLASS, IPPROTO_IPV6);
1096 if (*mp)
1097 mp = &(*mp)->m_next;
1098 }
1099
1100 /*
1101 * IPV6_HOPOPTS socket option. Recall that we required super-user
1102 * privilege for the option (see ip6_ctloutput), but it might be too
1103 * strict, since there might be some hop-by-hop options which can be
1104 * returned to normal user.
1105 * See also RFC 2292 section 6 (or RFC 3542 section 8).
1106 */
1107 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) {
1108 /*
1109 * Check if a hop-by-hop options header is contatined in the
1110 * received packet, and if so, store the options as ancillary
1111 * data. Note that a hop-by-hop options header must be
1112 * just after the IPv6 header, which is assured through the
1113 * IPv6 input processing.
1114 */
1115 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
1116 struct ip6_hbh *hbh;
1117 int hbhlen = 0;
1118 #ifdef PULLDOWN_TEST
1119 struct mbuf *ext;
1120 #endif
1121
1122 #ifndef PULLDOWN_TEST
1123 hbh = (struct ip6_hbh *)(ip6 + 1);
1124 hbhlen = (hbh->ip6h_len + 1) << 3;
1125 #else
1126 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
1127 ip6->ip6_nxt);
1128 if (ext == NULL) {
1129 ip6stat.ip6s_tooshort++;
1130 return;
1131 }
1132 hbh = mtod(ext, struct ip6_hbh *);
1133 hbhlen = (hbh->ip6h_len + 1) << 3;
1134 if (hbhlen != ext->m_len) {
1135 m_freem(ext);
1136 ip6stat.ip6s_tooshort++;
1137 return;
1138 }
1139 #endif
1140
1141 /*
1142 * XXX: We copy the whole header even if a
1143 * jumbo payload option is included, the option which
1144 * is to be removed before returning according to
1145 * RFC2292.
1146 * Note: this constraint is removed in RFC3542
1147 */
1148 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
1149 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS),
1150 IPPROTO_IPV6);
1151 if (*mp)
1152 mp = &(*mp)->m_next;
1153 #ifdef PULLDOWN_TEST
1154 m_freem(ext);
1155 #endif
1156 }
1157 }
1158
1159 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) {
1160 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
1161
1162 /*
1163 * Search for destination options headers or routing
1164 * header(s) through the header chain, and stores each
1165 * header as ancillary data.
1166 * Note that the order of the headers remains in
1167 * the chain of ancillary data.
1168 */
1169 while (1) { /* is explicit loop prevention necessary? */
1170 struct ip6_ext *ip6e = NULL;
1171 int elen;
1172 #ifdef PULLDOWN_TEST
1173 struct mbuf *ext = NULL;
1174 #endif
1175
1176 /*
1177 * if it is not an extension header, don't try to
1178 * pull it from the chain.
1179 */
1180 switch (nxt) {
1181 case IPPROTO_DSTOPTS:
1182 case IPPROTO_ROUTING:
1183 case IPPROTO_HOPOPTS:
1184 case IPPROTO_AH: /* is it possible? */
1185 break;
1186 default:
1187 goto loopend;
1188 }
1189
1190 #ifndef PULLDOWN_TEST
1191 if (off + sizeof(*ip6e) > m->m_len)
1192 goto loopend;
1193 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
1194 if (nxt == IPPROTO_AH)
1195 elen = (ip6e->ip6e_len + 2) << 2;
1196 else
1197 elen = (ip6e->ip6e_len + 1) << 3;
1198 if (off + elen > m->m_len)
1199 goto loopend;
1200 #else
1201 ext = ip6_pullexthdr(m, off, nxt);
1202 if (ext == NULL) {
1203 ip6stat.ip6s_tooshort++;
1204 return;
1205 }
1206 ip6e = mtod(ext, struct ip6_ext *);
1207 if (nxt == IPPROTO_AH)
1208 elen = (ip6e->ip6e_len + 2) << 2;
1209 else
1210 elen = (ip6e->ip6e_len + 1) << 3;
1211 if (elen != ext->m_len) {
1212 m_freem(ext);
1213 ip6stat.ip6s_tooshort++;
1214 return;
1215 }
1216 #endif
1217
1218 switch (nxt) {
1219 case IPPROTO_DSTOPTS:
1220 if (!(in6p->in6p_flags & IN6P_DSTOPTS))
1221 break;
1222
1223 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1224 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS),
1225 IPPROTO_IPV6);
1226 if (*mp)
1227 mp = &(*mp)->m_next;
1228 break;
1229 case IPPROTO_ROUTING:
1230 if (!in6p->in6p_flags & IN6P_RTHDR)
1231 break;
1232
1233 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1234 IS2292(IPV6_2292RTHDR, IPV6_RTHDR),
1235 IPPROTO_IPV6);
1236 if (*mp)
1237 mp = &(*mp)->m_next;
1238 break;
1239 case IPPROTO_HOPOPTS:
1240 case IPPROTO_AH: /* is it possible? */
1241 break;
1242
1243 default:
1244 /*
1245 * other cases have been filtered in the above.
1246 * none will visit this case. here we supply
1247 * the code just in case (nxt overwritten or
1248 * other cases).
1249 */
1250 #ifdef PULLDOWN_TEST
1251 m_freem(ext);
1252 #endif
1253 goto loopend;
1254
1255 }
1256
1257 /* proceed with the next header. */
1258 off += elen;
1259 nxt = ip6e->ip6e_nxt;
1260 ip6e = NULL;
1261 #ifdef PULLDOWN_TEST
1262 m_freem(ext);
1263 ext = NULL;
1264 #endif
1265 }
1266 loopend:
1267 ;
1268 }
1269
1270 #undef IS2292
1271 }
1272
1273 void
1274 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu)
1275 {
1276 struct socket *so;
1277 struct mbuf *m_mtu;
1278 struct ip6_mtuinfo mtuctl;
1279
1280 so = in6p->inp_socket;
1281
1282 if (mtu == NULL)
1283 return;
1284
1285 #ifdef DIAGNOSTIC
1286 if (so == NULL) /* I believe this is impossible */
1287 panic("ip6_notify_pmtu: socket is NULL");
1288 #endif
1289
1290 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */
1291 mtuctl.ip6m_mtu = *mtu;
1292 mtuctl.ip6m_addr = *dst;
1293 if (sa6_recoverscope(&mtuctl.ip6m_addr))
1294 return;
1295
1296 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl),
1297 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL)
1298 return;
1299
1300 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu)
1301 == 0) {
1302 m_freem(m_mtu);
1303 /* XXX: should count statistics */
1304 } else
1305 sorwakeup(so);
1306
1307 return;
1308 }
1309
1310 #ifdef PULLDOWN_TEST
1311 /*
1312 * pull single extension header from mbuf chain. returns single mbuf that
1313 * contains the result, or NULL on error.
1314 */
1315 static struct mbuf *
1316 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt)
1317 {
1318 struct ip6_ext ip6e;
1319 size_t elen;
1320 struct mbuf *n;
1321
1322 #ifdef DIAGNOSTIC
1323 switch (nxt) {
1324 case IPPROTO_DSTOPTS:
1325 case IPPROTO_ROUTING:
1326 case IPPROTO_HOPOPTS:
1327 case IPPROTO_AH: /* is it possible? */
1328 break;
1329 default:
1330 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
1331 }
1332 #endif
1333
1334 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1335 if (nxt == IPPROTO_AH)
1336 elen = (ip6e.ip6e_len + 2) << 2;
1337 else
1338 elen = (ip6e.ip6e_len + 1) << 3;
1339
1340 MGET(n, M_DONTWAIT, MT_DATA);
1341 if (n && elen >= MLEN) {
1342 MCLGET(n, M_DONTWAIT);
1343 if ((n->m_flags & M_EXT) == 0) {
1344 m_free(n);
1345 n = NULL;
1346 }
1347 }
1348 if (!n)
1349 return NULL;
1350
1351 n->m_len = 0;
1352 if (elen >= M_TRAILINGSPACE(n)) {
1353 m_free(n);
1354 return NULL;
1355 }
1356
1357 m_copydata(m, off, elen, mtod(n, caddr_t));
1358 n->m_len = elen;
1359 return n;
1360 }
1361 #endif
1362
1363 /*
1364 * Get pointer to the previous header followed by the header
1365 * currently processed.
1366 * XXX: This function supposes that
1367 * M includes all headers,
1368 * the next header field and the header length field of each header
1369 * are valid, and
1370 * the sum of each header length equals to OFF.
1371 * Because of these assumptions, this function must be called very
1372 * carefully. Moreover, it will not be used in the near future when
1373 * we develop `neater' mechanism to process extension headers.
1374 */
1375 char *
1376 ip6_get_prevhdr(struct mbuf *m, int off)
1377 {
1378 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1379
1380 if (off == sizeof(struct ip6_hdr))
1381 return (&ip6->ip6_nxt);
1382 else {
1383 int len, nxt;
1384 struct ip6_ext *ip6e = NULL;
1385
1386 nxt = ip6->ip6_nxt;
1387 len = sizeof(struct ip6_hdr);
1388 while (len < off) {
1389 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);
1390
1391 switch (nxt) {
1392 case IPPROTO_FRAGMENT:
1393 len += sizeof(struct ip6_frag);
1394 break;
1395 case IPPROTO_AH:
1396 len += (ip6e->ip6e_len + 2) << 2;
1397 break;
1398 default:
1399 len += (ip6e->ip6e_len + 1) << 3;
1400 break;
1401 }
1402 nxt = ip6e->ip6e_nxt;
1403 }
1404 if (ip6e)
1405 return (&ip6e->ip6e_nxt);
1406 else
1407 return NULL;
1408 }
1409 }
1410
1411 /*
1412 * get next header offset. m will be retained.
1413 */
1414 int
1415 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp)
1416 {
1417 struct ip6_hdr ip6;
1418 struct ip6_ext ip6e;
1419 struct ip6_frag fh;
1420
1421 /* just in case */
1422 if (m == NULL)
1423 panic("ip6_nexthdr: m == NULL");
1424 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
1425 return -1;
1426
1427 switch (proto) {
1428 case IPPROTO_IPV6:
1429 if (m->m_pkthdr.len < off + sizeof(ip6))
1430 return -1;
1431 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
1432 if (nxtp)
1433 *nxtp = ip6.ip6_nxt;
1434 off += sizeof(ip6);
1435 return off;
1436
1437 case IPPROTO_FRAGMENT:
1438 /*
1439 * terminate parsing if it is not the first fragment,
1440 * it does not make sense to parse through it.
1441 */
1442 if (m->m_pkthdr.len < off + sizeof(fh))
1443 return -1;
1444 m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
1445 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */
1446 if (fh.ip6f_offlg & IP6F_OFF_MASK)
1447 return -1;
1448 if (nxtp)
1449 *nxtp = fh.ip6f_nxt;
1450 off += sizeof(struct ip6_frag);
1451 return off;
1452
1453 case IPPROTO_AH:
1454 if (m->m_pkthdr.len < off + sizeof(ip6e))
1455 return -1;
1456 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1457 if (nxtp)
1458 *nxtp = ip6e.ip6e_nxt;
1459 off += (ip6e.ip6e_len + 2) << 2;
1460 return off;
1461
1462 case IPPROTO_HOPOPTS:
1463 case IPPROTO_ROUTING:
1464 case IPPROTO_DSTOPTS:
1465 if (m->m_pkthdr.len < off + sizeof(ip6e))
1466 return -1;
1467 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1468 if (nxtp)
1469 *nxtp = ip6e.ip6e_nxt;
1470 off += (ip6e.ip6e_len + 1) << 3;
1471 return off;
1472
1473 case IPPROTO_NONE:
1474 case IPPROTO_ESP:
1475 case IPPROTO_IPCOMP:
1476 /* give up */
1477 return -1;
1478
1479 default:
1480 return -1;
1481 }
1482
1483 return -1;
1484 }
1485
1486 /*
1487 * get offset for the last header in the chain. m will be kept untainted.
1488 */
1489 int
1490 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp)
1491 {
1492 int newoff;
1493 int nxt;
1494
1495 if (!nxtp) {
1496 nxt = -1;
1497 nxtp = &nxt;
1498 }
1499 while (1) {
1500 newoff = ip6_nexthdr(m, off, proto, nxtp);
1501 if (newoff < 0)
1502 return off;
1503 else if (newoff < off)
1504 return -1; /* invalid */
1505 else if (newoff == off)
1506 return newoff;
1507
1508 off = newoff;
1509 proto = *nxtp;
1510 }
1511 }
1512
1513 struct ip6aux *
1514 ip6_addaux(struct mbuf *m)
1515 {
1516 struct m_tag *mtag;
1517
1518 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1519 if (!mtag) {
1520 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux),
1521 M_NOWAIT);
1522 if (mtag) {
1523 m_tag_prepend(m, mtag);
1524 bzero(mtag + 1, sizeof(struct ip6aux));
1525 }
1526 }
1527 return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1528 }
1529
1530 struct ip6aux *
1531 ip6_findaux(struct mbuf *m)
1532 {
1533 struct m_tag *mtag;
1534
1535 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1536 return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1537 }
1538
1539 void
1540 ip6_delaux(struct mbuf *m)
1541 {
1542 struct m_tag *mtag;
1543
1544 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1545 if (mtag)
1546 m_tag_delete(m, mtag);
1547 }
1548
1549 /*
1550 * System control for IP6
1551 */
1552
1553 u_char inet6ctlerrmap[PRC_NCMDS] = {
1554 0, 0, 0, 0,
1555 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1556 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1557 EMSGSIZE, EHOSTUNREACH, 0, 0,
1558 0, 0, 0, 0,
1559 ENOPROTOOPT
1560 };
Cache object: 3ba33da8858efb0b337c34908ea4556b
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