1 /* $FreeBSD: releng/6.1/sys/netinet6/ip6_input.c 158179 2006-04-30 16:44:43Z cvs2svn $ */
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_ip6fw.h"
65 #include "opt_inet.h"
66 #include "opt_inet6.h"
67 #include "opt_ipsec.h"
68
69 #include <sys/param.h>
70 #include <sys/systm.h>
71 #include <sys/malloc.h>
72 #include <sys/mbuf.h>
73 #include <sys/proc.h>
74 #include <sys/domain.h>
75 #include <sys/protosw.h>
76 #include <sys/socket.h>
77 #include <sys/socketvar.h>
78 #include <sys/errno.h>
79 #include <sys/time.h>
80 #include <sys/kernel.h>
81 #include <sys/syslog.h>
82
83 #include <net/if.h>
84 #include <net/if_types.h>
85 #include <net/if_dl.h>
86 #include <net/route.h>
87 #include <net/netisr.h>
88 #include <net/pfil.h>
89
90 #include <netinet/in.h>
91 #include <netinet/in_systm.h>
92 #ifdef INET
93 #include <netinet/ip.h>
94 #include <netinet/ip_icmp.h>
95 #endif /* INET */
96 #include <netinet/ip6.h>
97 #include <netinet6/in6_var.h>
98 #include <netinet6/ip6_var.h>
99 #include <netinet/in_pcb.h>
100 #include <netinet/icmp6.h>
101 #include <netinet6/scope6_var.h>
102 #include <netinet6/in6_ifattach.h>
103 #include <netinet6/nd6.h>
104
105 #ifdef IPSEC
106 #include <netinet6/ipsec.h>
107 #ifdef INET6
108 #include <netinet6/ipsec6.h>
109 #endif
110 #endif
111
112 #ifdef FAST_IPSEC
113 #include <netipsec/ipsec.h>
114 #include <netipsec/ipsec6.h>
115 #define IPSEC
116 #endif /* FAST_IPSEC */
117
118 #include <netinet6/ip6_fw.h>
119
120 #include <netinet6/ip6protosw.h>
121
122 #include <net/net_osdep.h>
123
124 extern struct domain inet6domain;
125
126 u_char ip6_protox[IPPROTO_MAX];
127 static struct ifqueue ip6intrq;
128 static int ip6qmaxlen = IFQ_MAXLEN;
129 struct in6_ifaddr *in6_ifaddr;
130
131 extern struct callout in6_tmpaddrtimer_ch;
132
133 int ip6_forward_srcrt; /* XXX */
134 int ip6_sourcecheck; /* XXX */
135 int ip6_sourcecheck_interval; /* XXX */
136
137 int ip6_ours_check_algorithm;
138
139 struct pfil_head inet6_pfil_hook;
140
141 /* firewall hooks */
142 ip6_fw_chk_t *ip6_fw_chk_ptr;
143 ip6_fw_ctl_t *ip6_fw_ctl_ptr;
144 int ip6_fw_enable = 1;
145
146 struct ip6stat ip6stat;
147
148 static void ip6_init2 __P((void *));
149 static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *));
150 static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *));
151 #ifdef PULLDOWN_TEST
152 static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int));
153 #endif
154
155 /*
156 * IP6 initialization: fill in IP6 protocol switch table.
157 * All protocols not implemented in kernel go to raw IP6 protocol handler.
158 */
159 void
160 ip6_init()
161 {
162 struct ip6protosw *pr;
163 int i;
164
165 #ifdef DIAGNOSTIC
166 if (sizeof(struct protosw) != sizeof(struct ip6protosw))
167 panic("sizeof(protosw) != sizeof(ip6protosw)");
168 #endif
169 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
170 if (pr == 0)
171 panic("ip6_init");
172
173 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
174 for (i = 0; i < IPPROTO_MAX; i++)
175 ip6_protox[i] = pr - inet6sw;
176 /*
177 * Cycle through IP protocols and put them into the appropriate place
178 * in ip6_protox[].
179 */
180 for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
181 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++)
182 if (pr->pr_domain->dom_family == PF_INET6 &&
183 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
184 /* Be careful to only index valid IP protocols. */
185 if (pr->pr_protocol < IPPROTO_MAX)
186 ip6_protox[pr->pr_protocol] = pr - inet6sw;
187 }
188
189 /* Initialize packet filter hooks. */
190 inet6_pfil_hook.ph_type = PFIL_TYPE_AF;
191 inet6_pfil_hook.ph_af = AF_INET6;
192 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0)
193 printf("%s: WARNING: unable to register pfil hook, "
194 "error %d\n", __func__, i);
195
196 ip6intrq.ifq_maxlen = ip6qmaxlen;
197 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF);
198 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0);
199 scope6_init();
200 addrsel_policy_init();
201 nd6_init();
202 frag6_init();
203 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR;
204 }
205
206 static void
207 ip6_init2(dummy)
208 void *dummy;
209 {
210
211 /* nd6_timer_init */
212 callout_init(&nd6_timer_ch, 0);
213 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL);
214
215 /* timer for regeneranation of temporary addresses randomize ID */
216 callout_init(&in6_tmpaddrtimer_ch, 0);
217 callout_reset(&in6_tmpaddrtimer_ch,
218 (ip6_temp_preferred_lifetime - ip6_desync_factor -
219 ip6_temp_regen_advance) * hz,
220 in6_tmpaddrtimer, NULL);
221 }
222
223 /* cheat */
224 /* This must be after route_init(), which is now SI_ORDER_THIRD */
225 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL);
226
227 extern struct route_in6 ip6_forward_rt;
228
229 void
230 ip6_input(m)
231 struct mbuf *m;
232 {
233 struct ip6_hdr *ip6;
234 int off = sizeof(struct ip6_hdr), nest;
235 u_int32_t plen;
236 u_int32_t rtalert = ~0;
237 int nxt, ours = 0;
238 struct ifnet *deliverifp = NULL;
239 struct in6_addr odst;
240 int srcrt = 0;
241
242 GIANT_REQUIRED; /* XXX for now */
243 #ifdef IPSEC
244 /*
245 * should the inner packet be considered authentic?
246 * see comment in ah4_input().
247 */
248 if (m) {
249 m->m_flags &= ~M_AUTHIPHDR;
250 m->m_flags &= ~M_AUTHIPDGM;
251 }
252 #endif
253
254 /*
255 * make sure we don't have onion peering information into m_tag.
256 */
257 ip6_delaux(m);
258
259 /*
260 * mbuf statistics
261 */
262 if (m->m_flags & M_EXT) {
263 if (m->m_next)
264 ip6stat.ip6s_mext2m++;
265 else
266 ip6stat.ip6s_mext1++;
267 } else {
268 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0]))
269 if (m->m_next) {
270 if (m->m_flags & M_LOOP) {
271 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */
272 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX)
273 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++;
274 else
275 ip6stat.ip6s_m2m[0]++;
276 } else
277 ip6stat.ip6s_m1++;
278 #undef M2MMAX
279 }
280
281 /* drop the packet if IPv6 operation is disabled on the IF */
282 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) {
283 m_freem(m);
284 return;
285 }
286
287 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
288 ip6stat.ip6s_total++;
289
290 #ifndef PULLDOWN_TEST
291 /*
292 * L2 bridge code and some other code can return mbuf chain
293 * that does not conform to KAME requirement. too bad.
294 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram?
295 */
296 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) {
297 struct mbuf *n;
298
299 MGETHDR(n, M_DONTWAIT, MT_HEADER);
300 if (n)
301 M_MOVE_PKTHDR(n, m);
302 if (n && n->m_pkthdr.len > MHLEN) {
303 MCLGET(n, M_DONTWAIT);
304 if ((n->m_flags & M_EXT) == 0) {
305 m_freem(n);
306 n = NULL;
307 }
308 }
309 if (n == NULL) {
310 m_freem(m);
311 return; /* ENOBUFS */
312 }
313
314 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
315 n->m_len = n->m_pkthdr.len;
316 m_freem(m);
317 m = n;
318 }
319 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */);
320 #endif
321
322 if (m->m_len < sizeof(struct ip6_hdr)) {
323 struct ifnet *inifp;
324 inifp = m->m_pkthdr.rcvif;
325 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
326 ip6stat.ip6s_toosmall++;
327 in6_ifstat_inc(inifp, ifs6_in_hdrerr);
328 return;
329 }
330 }
331
332 ip6 = mtod(m, struct ip6_hdr *);
333
334 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
335 ip6stat.ip6s_badvers++;
336 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
337 goto bad;
338 }
339
340 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++;
341
342 /*
343 * Check against address spoofing/corruption.
344 */
345 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
346 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
347 /*
348 * XXX: "badscope" is not very suitable for a multicast source.
349 */
350 ip6stat.ip6s_badscope++;
351 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
352 goto bad;
353 }
354 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) &&
355 !(m->m_flags & M_LOOP)) {
356 /*
357 * In this case, the packet should come from the loopback
358 * interface. However, we cannot just check the if_flags,
359 * because ip6_mloopback() passes the "actual" interface
360 * as the outgoing/incoming interface.
361 */
362 ip6stat.ip6s_badscope++;
363 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
364 goto bad;
365 }
366
367 #ifdef ALTQ
368 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) {
369 /* packet is dropped by traffic conditioner */
370 return;
371 }
372 #endif
373 /*
374 * The following check is not documented in specs. A malicious
375 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
376 * and bypass security checks (act as if it was from 127.0.0.1 by using
377 * IPv6 src ::ffff:127.0.0.1). Be cautious.
378 *
379 * This check chokes if we are in an SIIT cloud. As none of BSDs
380 * support IPv4-less kernel compilation, we cannot support SIIT
381 * environment at all. So, it makes more sense for us to reject any
382 * malicious packets for non-SIIT environment, than try to do a
383 * partial support for SIIT environment.
384 */
385 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
386 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
387 ip6stat.ip6s_badscope++;
388 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
389 goto bad;
390 }
391 #if 0
392 /*
393 * Reject packets with IPv4 compatible addresses (auto tunnel).
394 *
395 * The code forbids auto tunnel relay case in RFC1933 (the check is
396 * stronger than RFC1933). We may want to re-enable it if mech-xx
397 * is revised to forbid relaying case.
398 */
399 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
400 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
401 ip6stat.ip6s_badscope++;
402 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
403 goto bad;
404 }
405 #endif
406
407 /*
408 * Run through list of hooks for input packets.
409 *
410 * NB: Beware of the destination address changing
411 * (e.g. by NAT rewriting). When this happens,
412 * tell ip6_forward to do the right thing.
413 */
414 odst = ip6->ip6_dst;
415
416 /* Jump over all PFIL processing if hooks are not active. */
417 if (inet6_pfil_hook.ph_busy_count == -1)
418 goto passin;
419
420 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL))
421 return;
422 if (m == NULL) /* consumed by filter */
423 return;
424 ip6 = mtod(m, struct ip6_hdr *);
425 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
426
427 passin:
428 /*
429 * Check with the firewall...
430 */
431 if (ip6_fw_enable && ip6_fw_chk_ptr) {
432 u_short port = 0;
433 /* If ipfw says divert, we have to just drop packet */
434 /* use port as a dummy argument */
435 if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) {
436 m_freem(m);
437 m = NULL;
438 }
439 if (!m)
440 return;
441 }
442
443 /*
444 * Disambiguate address scope zones (if there is ambiguity).
445 * We first make sure that the original source or destination address
446 * is not in our internal form for scoped addresses. Such addresses
447 * are not necessarily invalid spec-wise, but we cannot accept them due
448 * to the usage conflict.
449 * in6_setscope() then also checks and rejects the cases where src or
450 * dst are the loopback address and the receiving interface
451 * is not loopback.
452 */
453 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) {
454 ip6stat.ip6s_badscope++; /* XXX */
455 goto bad;
456 }
457 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) ||
458 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) {
459 ip6stat.ip6s_badscope++;
460 goto bad;
461 }
462
463 /*
464 * Multicast check
465 */
466 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
467 struct in6_multi *in6m = 0;
468
469 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
470 /*
471 * See if we belong to the destination multicast group on the
472 * arrival interface.
473 */
474 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m);
475 if (in6m)
476 ours = 1;
477 else if (!ip6_mrouter) {
478 ip6stat.ip6s_notmember++;
479 ip6stat.ip6s_cantforward++;
480 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
481 goto bad;
482 }
483 deliverifp = m->m_pkthdr.rcvif;
484 goto hbhcheck;
485 }
486
487 /*
488 * Unicast check
489 */
490 if (ip6_forward_rt.ro_rt != NULL &&
491 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 &&
492 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
493 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr))
494 ip6stat.ip6s_forward_cachehit++;
495 else {
496 struct sockaddr_in6 *dst6;
497
498 if (ip6_forward_rt.ro_rt) {
499 /* route is down or destination is different */
500 ip6stat.ip6s_forward_cachemiss++;
501 RTFREE(ip6_forward_rt.ro_rt);
502 ip6_forward_rt.ro_rt = 0;
503 }
504
505 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6));
506 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst;
507 dst6->sin6_len = sizeof(struct sockaddr_in6);
508 dst6->sin6_family = AF_INET6;
509 dst6->sin6_addr = ip6->ip6_dst;
510
511 rtalloc((struct route *)&ip6_forward_rt);
512 }
513
514 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))
515
516 /*
517 * Accept the packet if the forwarding interface to the destination
518 * according to the routing table is the loopback interface,
519 * unless the associated route has a gateway.
520 * Note that this approach causes to accept a packet if there is a
521 * route to the loopback interface for the destination of the packet.
522 * But we think it's even useful in some situations, e.g. when using
523 * a special daemon which wants to intercept the packet.
524 *
525 * XXX: some OSes automatically make a cloned route for the destination
526 * of an outgoing packet. If the outgoing interface of the packet
527 * is a loopback one, the kernel would consider the packet to be
528 * accepted, even if we have no such address assinged on the interface.
529 * We check the cloned flag of the route entry to reject such cases,
530 * assuming that route entries for our own addresses are not made by
531 * cloning (it should be true because in6_addloop explicitly installs
532 * the host route). However, we might have to do an explicit check
533 * while it would be less efficient. Or, should we rather install a
534 * reject route for such a case?
535 */
536 if (ip6_forward_rt.ro_rt &&
537 (ip6_forward_rt.ro_rt->rt_flags &
538 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
539 #ifdef RTF_WASCLONED
540 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) &&
541 #endif
542 #ifdef RTF_CLONED
543 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) &&
544 #endif
545 #if 0
546 /*
547 * The check below is redundant since the comparison of
548 * the destination and the key of the rtentry has
549 * already done through looking up the routing table.
550 */
551 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
552 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr)
553 #endif
554 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) {
555 struct in6_ifaddr *ia6 =
556 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa;
557
558 /*
559 * record address information into m_tag.
560 */
561 (void)ip6_setdstifaddr(m, ia6);
562
563 /*
564 * packets to a tentative, duplicated, or somehow invalid
565 * address must not be accepted.
566 */
567 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
568 /* this address is ready */
569 ours = 1;
570 deliverifp = ia6->ia_ifp; /* correct? */
571 /* Count the packet in the ip address stats */
572 ia6->ia_ifa.if_ipackets++;
573 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
574 goto hbhcheck;
575 } else {
576 /* address is not ready, so discard the packet. */
577 nd6log((LOG_INFO,
578 "ip6_input: packet to an unready address %s->%s\n",
579 ip6_sprintf(&ip6->ip6_src),
580 ip6_sprintf(&ip6->ip6_dst)));
581
582 goto bad;
583 }
584 }
585
586 /*
587 * FAITH (Firewall Aided Internet Translator)
588 */
589 if (ip6_keepfaith) {
590 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp
591 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) {
592 /* XXX do we need more sanity checks? */
593 ours = 1;
594 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */
595 goto hbhcheck;
596 }
597 }
598
599 /*
600 * Now there is no reason to process the packet if it's not our own
601 * and we're not a router.
602 */
603 if (!ip6_forwarding) {
604 ip6stat.ip6s_cantforward++;
605 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
606 goto bad;
607 }
608
609 hbhcheck:
610 /*
611 * record address information into m_tag, if we don't have one yet.
612 * note that we are unable to record it, if the address is not listed
613 * as our interface address (e.g. multicast addresses, addresses
614 * within FAITH prefixes and such).
615 */
616 if (deliverifp && !ip6_getdstifaddr(m)) {
617 struct in6_ifaddr *ia6;
618
619 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
620 if (ia6) {
621 if (!ip6_setdstifaddr(m, ia6)) {
622 /*
623 * XXX maybe we should drop the packet here,
624 * as we could not provide enough information
625 * to the upper layers.
626 */
627 }
628 }
629 }
630
631 /*
632 * Process Hop-by-Hop options header if it's contained.
633 * m may be modified in ip6_hopopts_input().
634 * If a JumboPayload option is included, plen will also be modified.
635 */
636 plen = (u_int32_t)ntohs(ip6->ip6_plen);
637 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
638 struct ip6_hbh *hbh;
639
640 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) {
641 #if 0 /*touches NULL pointer*/
642 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
643 #endif
644 return; /* m have already been freed */
645 }
646
647 /* adjust pointer */
648 ip6 = mtod(m, struct ip6_hdr *);
649
650 /*
651 * if the payload length field is 0 and the next header field
652 * indicates Hop-by-Hop Options header, then a Jumbo Payload
653 * option MUST be included.
654 */
655 if (ip6->ip6_plen == 0 && plen == 0) {
656 /*
657 * Note that if a valid jumbo payload option is
658 * contained, ip6_hopopts_input() must set a valid
659 * (non-zero) payload length to the variable plen.
660 */
661 ip6stat.ip6s_badoptions++;
662 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
663 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
664 icmp6_error(m, ICMP6_PARAM_PROB,
665 ICMP6_PARAMPROB_HEADER,
666 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
667 return;
668 }
669 #ifndef PULLDOWN_TEST
670 /* ip6_hopopts_input() ensures that mbuf is contiguous */
671 hbh = (struct ip6_hbh *)(ip6 + 1);
672 #else
673 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
674 sizeof(struct ip6_hbh));
675 if (hbh == NULL) {
676 ip6stat.ip6s_tooshort++;
677 return;
678 }
679 #endif
680 nxt = hbh->ip6h_nxt;
681
682 /*
683 * accept the packet if a router alert option is included
684 * and we act as an IPv6 router.
685 */
686 if (rtalert != ~0 && ip6_forwarding)
687 ours = 1;
688 } else
689 nxt = ip6->ip6_nxt;
690
691 /*
692 * Check that the amount of data in the buffers
693 * is as at least much as the IPv6 header would have us expect.
694 * Trim mbufs if longer than we expect.
695 * Drop packet if shorter than we expect.
696 */
697 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
698 ip6stat.ip6s_tooshort++;
699 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
700 goto bad;
701 }
702 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
703 if (m->m_len == m->m_pkthdr.len) {
704 m->m_len = sizeof(struct ip6_hdr) + plen;
705 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
706 } else
707 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
708 }
709
710 /*
711 * Forward if desirable.
712 */
713 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
714 /*
715 * If we are acting as a multicast router, all
716 * incoming multicast packets are passed to the
717 * kernel-level multicast forwarding function.
718 * The packet is returned (relatively) intact; if
719 * ip6_mforward() returns a non-zero value, the packet
720 * must be discarded, else it may be accepted below.
721 */
722 if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
723 ip6stat.ip6s_cantforward++;
724 m_freem(m);
725 return;
726 }
727 if (!ours) {
728 m_freem(m);
729 return;
730 }
731 } else if (!ours) {
732 ip6_forward(m, srcrt);
733 return;
734 }
735
736 ip6 = mtod(m, struct ip6_hdr *);
737
738 /*
739 * Malicious party may be able to use IPv4 mapped addr to confuse
740 * tcp/udp stack and bypass security checks (act as if it was from
741 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious.
742 *
743 * For SIIT end node behavior, you may want to disable the check.
744 * However, you will become vulnerable to attacks using IPv4 mapped
745 * source.
746 */
747 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
748 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
749 ip6stat.ip6s_badscope++;
750 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
751 goto bad;
752 }
753
754 /*
755 * Tell launch routine the next header
756 */
757 ip6stat.ip6s_delivered++;
758 in6_ifstat_inc(deliverifp, ifs6_in_deliver);
759 nest = 0;
760
761 while (nxt != IPPROTO_DONE) {
762 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
763 ip6stat.ip6s_toomanyhdr++;
764 goto bad;
765 }
766
767 /*
768 * protection against faulty packet - there should be
769 * more sanity checks in header chain processing.
770 */
771 if (m->m_pkthdr.len < off) {
772 ip6stat.ip6s_tooshort++;
773 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
774 goto bad;
775 }
776
777 #ifdef IPSEC
778 /*
779 * enforce IPsec policy checking if we are seeing last header.
780 * note that we do not visit this with protocols with pcb layer
781 * code - like udp/tcp/raw ip.
782 */
783 if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
784 ipsec6_in_reject(m, NULL)) {
785 ipsec6stat.in_polvio++;
786 goto bad;
787 }
788 #endif
789 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
790 }
791 return;
792 bad:
793 m_freem(m);
794 }
795
796 /*
797 * set/grab in6_ifaddr correspond to IPv6 destination address.
798 * XXX backward compatibility wrapper
799 */
800 static struct ip6aux *
801 ip6_setdstifaddr(m, ia6)
802 struct mbuf *m;
803 struct in6_ifaddr *ia6;
804 {
805 struct ip6aux *ip6a;
806
807 ip6a = ip6_addaux(m);
808 if (ip6a)
809 ip6a->ip6a_dstia6 = ia6;
810 return ip6a; /* NULL if failed to set */
811 }
812
813 struct in6_ifaddr *
814 ip6_getdstifaddr(m)
815 struct mbuf *m;
816 {
817 struct ip6aux *ip6a;
818
819 ip6a = ip6_findaux(m);
820 if (ip6a)
821 return ip6a->ip6a_dstia6;
822 else
823 return NULL;
824 }
825
826 /*
827 * Hop-by-Hop options header processing. If a valid jumbo payload option is
828 * included, the real payload length will be stored in plenp.
829 */
830 static int
831 ip6_hopopts_input(plenp, rtalertp, mp, offp)
832 u_int32_t *plenp;
833 u_int32_t *rtalertp; /* XXX: should be stored more smart way */
834 struct mbuf **mp;
835 int *offp;
836 {
837 struct mbuf *m = *mp;
838 int off = *offp, hbhlen;
839 struct ip6_hbh *hbh;
840 u_int8_t *opt;
841
842 /* validation of the length of the header */
843 #ifndef PULLDOWN_TEST
844 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1);
845 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
846 hbhlen = (hbh->ip6h_len + 1) << 3;
847
848 IP6_EXTHDR_CHECK(m, off, hbhlen, -1);
849 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
850 #else
851 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
852 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
853 if (hbh == NULL) {
854 ip6stat.ip6s_tooshort++;
855 return -1;
856 }
857 hbhlen = (hbh->ip6h_len + 1) << 3;
858 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
859 hbhlen);
860 if (hbh == NULL) {
861 ip6stat.ip6s_tooshort++;
862 return -1;
863 }
864 #endif
865 off += hbhlen;
866 hbhlen -= sizeof(struct ip6_hbh);
867 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh);
868
869 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
870 hbhlen, rtalertp, plenp) < 0)
871 return (-1);
872
873 *offp = off;
874 *mp = m;
875 return (0);
876 }
877
878 /*
879 * Search header for all Hop-by-hop options and process each option.
880 * This function is separate from ip6_hopopts_input() in order to
881 * handle a case where the sending node itself process its hop-by-hop
882 * options header. In such a case, the function is called from ip6_output().
883 *
884 * The function assumes that hbh header is located right after the IPv6 header
885 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
886 * opthead + hbhlen is located in continuous memory region.
887 */
888 int
889 ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp)
890 struct mbuf *m;
891 u_int8_t *opthead;
892 int hbhlen;
893 u_int32_t *rtalertp;
894 u_int32_t *plenp;
895 {
896 struct ip6_hdr *ip6;
897 int optlen = 0;
898 u_int8_t *opt = opthead;
899 u_int16_t rtalert_val;
900 u_int32_t jumboplen;
901 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
902
903 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
904 switch (*opt) {
905 case IP6OPT_PAD1:
906 optlen = 1;
907 break;
908 case IP6OPT_PADN:
909 if (hbhlen < IP6OPT_MINLEN) {
910 ip6stat.ip6s_toosmall++;
911 goto bad;
912 }
913 optlen = *(opt + 1) + 2;
914 break;
915 case IP6OPT_ROUTER_ALERT:
916 /* XXX may need check for alignment */
917 if (hbhlen < IP6OPT_RTALERT_LEN) {
918 ip6stat.ip6s_toosmall++;
919 goto bad;
920 }
921 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
922 /* XXX stat */
923 icmp6_error(m, ICMP6_PARAM_PROB,
924 ICMP6_PARAMPROB_HEADER,
925 erroff + opt + 1 - opthead);
926 return (-1);
927 }
928 optlen = IP6OPT_RTALERT_LEN;
929 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
930 *rtalertp = ntohs(rtalert_val);
931 break;
932 case IP6OPT_JUMBO:
933 /* XXX may need check for alignment */
934 if (hbhlen < IP6OPT_JUMBO_LEN) {
935 ip6stat.ip6s_toosmall++;
936 goto bad;
937 }
938 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
939 /* XXX stat */
940 icmp6_error(m, ICMP6_PARAM_PROB,
941 ICMP6_PARAMPROB_HEADER,
942 erroff + opt + 1 - opthead);
943 return (-1);
944 }
945 optlen = IP6OPT_JUMBO_LEN;
946
947 /*
948 * IPv6 packets that have non 0 payload length
949 * must not contain a jumbo payload option.
950 */
951 ip6 = mtod(m, struct ip6_hdr *);
952 if (ip6->ip6_plen) {
953 ip6stat.ip6s_badoptions++;
954 icmp6_error(m, ICMP6_PARAM_PROB,
955 ICMP6_PARAMPROB_HEADER,
956 erroff + opt - opthead);
957 return (-1);
958 }
959
960 /*
961 * We may see jumbolen in unaligned location, so
962 * we'd need to perform bcopy().
963 */
964 bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
965 jumboplen = (u_int32_t)htonl(jumboplen);
966
967 #if 1
968 /*
969 * if there are multiple jumbo payload options,
970 * *plenp will be non-zero and the packet will be
971 * rejected.
972 * the behavior may need some debate in ipngwg -
973 * multiple options does not make sense, however,
974 * there's no explicit mention in specification.
975 */
976 if (*plenp != 0) {
977 ip6stat.ip6s_badoptions++;
978 icmp6_error(m, ICMP6_PARAM_PROB,
979 ICMP6_PARAMPROB_HEADER,
980 erroff + opt + 2 - opthead);
981 return (-1);
982 }
983 #endif
984
985 /*
986 * jumbo payload length must be larger than 65535.
987 */
988 if (jumboplen <= IPV6_MAXPACKET) {
989 ip6stat.ip6s_badoptions++;
990 icmp6_error(m, ICMP6_PARAM_PROB,
991 ICMP6_PARAMPROB_HEADER,
992 erroff + opt + 2 - opthead);
993 return (-1);
994 }
995 *plenp = jumboplen;
996
997 break;
998 default: /* unknown option */
999 if (hbhlen < IP6OPT_MINLEN) {
1000 ip6stat.ip6s_toosmall++;
1001 goto bad;
1002 }
1003 optlen = ip6_unknown_opt(opt, m,
1004 erroff + opt - opthead);
1005 if (optlen == -1)
1006 return (-1);
1007 optlen += 2;
1008 break;
1009 }
1010 }
1011
1012 return (0);
1013
1014 bad:
1015 m_freem(m);
1016 return (-1);
1017 }
1018
1019 /*
1020 * Unknown option processing.
1021 * The third argument `off' is the offset from the IPv6 header to the option,
1022 * which is necessary if the IPv6 header the and option header and IPv6 header
1023 * is not continuous in order to return an ICMPv6 error.
1024 */
1025 int
1026 ip6_unknown_opt(optp, m, off)
1027 u_int8_t *optp;
1028 struct mbuf *m;
1029 int off;
1030 {
1031 struct ip6_hdr *ip6;
1032
1033 switch (IP6OPT_TYPE(*optp)) {
1034 case IP6OPT_TYPE_SKIP: /* ignore the option */
1035 return ((int)*(optp + 1));
1036 case IP6OPT_TYPE_DISCARD: /* silently discard */
1037 m_freem(m);
1038 return (-1);
1039 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
1040 ip6stat.ip6s_badoptions++;
1041 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
1042 return (-1);
1043 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
1044 ip6stat.ip6s_badoptions++;
1045 ip6 = mtod(m, struct ip6_hdr *);
1046 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
1047 (m->m_flags & (M_BCAST|M_MCAST)))
1048 m_freem(m);
1049 else
1050 icmp6_error(m, ICMP6_PARAM_PROB,
1051 ICMP6_PARAMPROB_OPTION, off);
1052 return (-1);
1053 }
1054
1055 m_freem(m); /* XXX: NOTREACHED */
1056 return (-1);
1057 }
1058
1059 /*
1060 * Create the "control" list for this pcb.
1061 * The function will not modify mbuf chain at all.
1062 *
1063 * with KAME mbuf chain restriction:
1064 * The routine will be called from upper layer handlers like tcp6_input().
1065 * Thus the routine assumes that the caller (tcp6_input) have already
1066 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the
1067 * very first mbuf on the mbuf chain.
1068 */
1069 void
1070 ip6_savecontrol(in6p, m, mp)
1071 struct inpcb *in6p;
1072 struct mbuf *m, **mp;
1073 {
1074 #define IS2292(x, y) ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y))
1075 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1076
1077 #ifdef SO_TIMESTAMP
1078 if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) {
1079 struct timeval tv;
1080
1081 microtime(&tv);
1082 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1083 SCM_TIMESTAMP, SOL_SOCKET);
1084 if (*mp)
1085 mp = &(*mp)->m_next;
1086 }
1087 #endif
1088
1089 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION)
1090 return;
1091
1092 /* RFC 2292 sec. 5 */
1093 if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) {
1094 struct in6_pktinfo pi6;
1095
1096 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
1097 in6_clearscope(&pi6.ipi6_addr); /* XXX */
1098 pi6.ipi6_ifindex =
1099 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0;
1100
1101 *mp = sbcreatecontrol((caddr_t) &pi6,
1102 sizeof(struct in6_pktinfo),
1103 IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6);
1104 if (*mp)
1105 mp = &(*mp)->m_next;
1106 }
1107
1108 if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) {
1109 int hlim = ip6->ip6_hlim & 0xff;
1110
1111 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int),
1112 IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6);
1113 if (*mp)
1114 mp = &(*mp)->m_next;
1115 }
1116
1117 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) {
1118 u_int32_t flowinfo;
1119 int tclass;
1120
1121 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
1122 flowinfo >>= 20;
1123
1124 tclass = flowinfo & 0xff;
1125 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass),
1126 IPV6_TCLASS, IPPROTO_IPV6);
1127 if (*mp)
1128 mp = &(*mp)->m_next;
1129 }
1130
1131 /*
1132 * IPV6_HOPOPTS socket option. Recall that we required super-user
1133 * privilege for the option (see ip6_ctloutput), but it might be too
1134 * strict, since there might be some hop-by-hop options which can be
1135 * returned to normal user.
1136 * See also RFC 2292 section 6 (or RFC 3542 section 8).
1137 */
1138 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) {
1139 /*
1140 * Check if a hop-by-hop options header is contatined in the
1141 * received packet, and if so, store the options as ancillary
1142 * data. Note that a hop-by-hop options header must be
1143 * just after the IPv6 header, which is assured through the
1144 * IPv6 input processing.
1145 */
1146 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
1147 struct ip6_hbh *hbh;
1148 int hbhlen = 0;
1149 #ifdef PULLDOWN_TEST
1150 struct mbuf *ext;
1151 #endif
1152
1153 #ifndef PULLDOWN_TEST
1154 hbh = (struct ip6_hbh *)(ip6 + 1);
1155 hbhlen = (hbh->ip6h_len + 1) << 3;
1156 #else
1157 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
1158 ip6->ip6_nxt);
1159 if (ext == NULL) {
1160 ip6stat.ip6s_tooshort++;
1161 return;
1162 }
1163 hbh = mtod(ext, struct ip6_hbh *);
1164 hbhlen = (hbh->ip6h_len + 1) << 3;
1165 if (hbhlen != ext->m_len) {
1166 m_freem(ext);
1167 ip6stat.ip6s_tooshort++;
1168 return;
1169 }
1170 #endif
1171
1172 /*
1173 * XXX: We copy the whole header even if a
1174 * jumbo payload option is included, the option which
1175 * is to be removed before returning according to
1176 * RFC2292.
1177 * Note: this constraint is removed in RFC3542
1178 */
1179 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
1180 IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS),
1181 IPPROTO_IPV6);
1182 if (*mp)
1183 mp = &(*mp)->m_next;
1184 #ifdef PULLDOWN_TEST
1185 m_freem(ext);
1186 #endif
1187 }
1188 }
1189
1190 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) {
1191 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
1192
1193 /*
1194 * Search for destination options headers or routing
1195 * header(s) through the header chain, and stores each
1196 * header as ancillary data.
1197 * Note that the order of the headers remains in
1198 * the chain of ancillary data.
1199 */
1200 while (1) { /* is explicit loop prevention necessary? */
1201 struct ip6_ext *ip6e = NULL;
1202 int elen;
1203 #ifdef PULLDOWN_TEST
1204 struct mbuf *ext = NULL;
1205 #endif
1206
1207 /*
1208 * if it is not an extension header, don't try to
1209 * pull it from the chain.
1210 */
1211 switch (nxt) {
1212 case IPPROTO_DSTOPTS:
1213 case IPPROTO_ROUTING:
1214 case IPPROTO_HOPOPTS:
1215 case IPPROTO_AH: /* is it possible? */
1216 break;
1217 default:
1218 goto loopend;
1219 }
1220
1221 #ifndef PULLDOWN_TEST
1222 if (off + sizeof(*ip6e) > m->m_len)
1223 goto loopend;
1224 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
1225 if (nxt == IPPROTO_AH)
1226 elen = (ip6e->ip6e_len + 2) << 2;
1227 else
1228 elen = (ip6e->ip6e_len + 1) << 3;
1229 if (off + elen > m->m_len)
1230 goto loopend;
1231 #else
1232 ext = ip6_pullexthdr(m, off, nxt);
1233 if (ext == NULL) {
1234 ip6stat.ip6s_tooshort++;
1235 return;
1236 }
1237 ip6e = mtod(ext, struct ip6_ext *);
1238 if (nxt == IPPROTO_AH)
1239 elen = (ip6e->ip6e_len + 2) << 2;
1240 else
1241 elen = (ip6e->ip6e_len + 1) << 3;
1242 if (elen != ext->m_len) {
1243 m_freem(ext);
1244 ip6stat.ip6s_tooshort++;
1245 return;
1246 }
1247 #endif
1248
1249 switch (nxt) {
1250 case IPPROTO_DSTOPTS:
1251 if (!(in6p->in6p_flags & IN6P_DSTOPTS))
1252 break;
1253
1254 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1255 IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS),
1256 IPPROTO_IPV6);
1257 if (*mp)
1258 mp = &(*mp)->m_next;
1259 break;
1260 case IPPROTO_ROUTING:
1261 if (!in6p->in6p_flags & IN6P_RTHDR)
1262 break;
1263
1264 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1265 IS2292(IPV6_2292RTHDR, IPV6_RTHDR),
1266 IPPROTO_IPV6);
1267 if (*mp)
1268 mp = &(*mp)->m_next;
1269 break;
1270 case IPPROTO_HOPOPTS:
1271 case IPPROTO_AH: /* is it possible? */
1272 break;
1273
1274 default:
1275 /*
1276 * other cases have been filtered in the above.
1277 * none will visit this case. here we supply
1278 * the code just in case (nxt overwritten or
1279 * other cases).
1280 */
1281 #ifdef PULLDOWN_TEST
1282 m_freem(ext);
1283 #endif
1284 goto loopend;
1285
1286 }
1287
1288 /* proceed with the next header. */
1289 off += elen;
1290 nxt = ip6e->ip6e_nxt;
1291 ip6e = NULL;
1292 #ifdef PULLDOWN_TEST
1293 m_freem(ext);
1294 ext = NULL;
1295 #endif
1296 }
1297 loopend:
1298 ;
1299 }
1300
1301 #undef IS2292
1302 }
1303
1304 void
1305 ip6_notify_pmtu(in6p, dst, mtu)
1306 struct inpcb *in6p;
1307 struct sockaddr_in6 *dst;
1308 u_int32_t *mtu;
1309 {
1310 struct socket *so;
1311 struct mbuf *m_mtu;
1312 struct ip6_mtuinfo mtuctl;
1313
1314 so = in6p->inp_socket;
1315
1316 if (mtu == NULL)
1317 return;
1318
1319 #ifdef DIAGNOSTIC
1320 if (so == NULL) /* I believe this is impossible */
1321 panic("ip6_notify_pmtu: socket is NULL");
1322 #endif
1323
1324 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */
1325 mtuctl.ip6m_mtu = *mtu;
1326 mtuctl.ip6m_addr = *dst;
1327 if (sa6_recoverscope(&mtuctl.ip6m_addr))
1328 return;
1329
1330 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl),
1331 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL)
1332 return;
1333
1334 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu)
1335 == 0) {
1336 m_freem(m_mtu);
1337 /* XXX: should count statistics */
1338 } else
1339 sorwakeup(so);
1340
1341 return;
1342 }
1343
1344 #ifdef PULLDOWN_TEST
1345 /*
1346 * pull single extension header from mbuf chain. returns single mbuf that
1347 * contains the result, or NULL on error.
1348 */
1349 static struct mbuf *
1350 ip6_pullexthdr(m, off, nxt)
1351 struct mbuf *m;
1352 size_t off;
1353 int nxt;
1354 {
1355 struct ip6_ext ip6e;
1356 size_t elen;
1357 struct mbuf *n;
1358
1359 #ifdef DIAGNOSTIC
1360 switch (nxt) {
1361 case IPPROTO_DSTOPTS:
1362 case IPPROTO_ROUTING:
1363 case IPPROTO_HOPOPTS:
1364 case IPPROTO_AH: /* is it possible? */
1365 break;
1366 default:
1367 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
1368 }
1369 #endif
1370
1371 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1372 if (nxt == IPPROTO_AH)
1373 elen = (ip6e.ip6e_len + 2) << 2;
1374 else
1375 elen = (ip6e.ip6e_len + 1) << 3;
1376
1377 MGET(n, M_DONTWAIT, MT_DATA);
1378 if (n && elen >= MLEN) {
1379 MCLGET(n, M_DONTWAIT);
1380 if ((n->m_flags & M_EXT) == 0) {
1381 m_free(n);
1382 n = NULL;
1383 }
1384 }
1385 if (!n)
1386 return NULL;
1387
1388 n->m_len = 0;
1389 if (elen >= M_TRAILINGSPACE(n)) {
1390 m_free(n);
1391 return NULL;
1392 }
1393
1394 m_copydata(m, off, elen, mtod(n, caddr_t));
1395 n->m_len = elen;
1396 return n;
1397 }
1398 #endif
1399
1400 /*
1401 * Get pointer to the previous header followed by the header
1402 * currently processed.
1403 * XXX: This function supposes that
1404 * M includes all headers,
1405 * the next header field and the header length field of each header
1406 * are valid, and
1407 * the sum of each header length equals to OFF.
1408 * Because of these assumptions, this function must be called very
1409 * carefully. Moreover, it will not be used in the near future when
1410 * we develop `neater' mechanism to process extension headers.
1411 */
1412 char *
1413 ip6_get_prevhdr(m, off)
1414 struct mbuf *m;
1415 int off;
1416 {
1417 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1418
1419 if (off == sizeof(struct ip6_hdr))
1420 return (&ip6->ip6_nxt);
1421 else {
1422 int len, nxt;
1423 struct ip6_ext *ip6e = NULL;
1424
1425 nxt = ip6->ip6_nxt;
1426 len = sizeof(struct ip6_hdr);
1427 while (len < off) {
1428 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);
1429
1430 switch (nxt) {
1431 case IPPROTO_FRAGMENT:
1432 len += sizeof(struct ip6_frag);
1433 break;
1434 case IPPROTO_AH:
1435 len += (ip6e->ip6e_len + 2) << 2;
1436 break;
1437 default:
1438 len += (ip6e->ip6e_len + 1) << 3;
1439 break;
1440 }
1441 nxt = ip6e->ip6e_nxt;
1442 }
1443 if (ip6e)
1444 return (&ip6e->ip6e_nxt);
1445 else
1446 return NULL;
1447 }
1448 }
1449
1450 /*
1451 * get next header offset. m will be retained.
1452 */
1453 int
1454 ip6_nexthdr(m, off, proto, nxtp)
1455 struct mbuf *m;
1456 int off;
1457 int proto;
1458 int *nxtp;
1459 {
1460 struct ip6_hdr ip6;
1461 struct ip6_ext ip6e;
1462 struct ip6_frag fh;
1463
1464 /* just in case */
1465 if (m == NULL)
1466 panic("ip6_nexthdr: m == NULL");
1467 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
1468 return -1;
1469
1470 switch (proto) {
1471 case IPPROTO_IPV6:
1472 if (m->m_pkthdr.len < off + sizeof(ip6))
1473 return -1;
1474 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
1475 if (nxtp)
1476 *nxtp = ip6.ip6_nxt;
1477 off += sizeof(ip6);
1478 return off;
1479
1480 case IPPROTO_FRAGMENT:
1481 /*
1482 * terminate parsing if it is not the first fragment,
1483 * it does not make sense to parse through it.
1484 */
1485 if (m->m_pkthdr.len < off + sizeof(fh))
1486 return -1;
1487 m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
1488 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */
1489 if (fh.ip6f_offlg & IP6F_OFF_MASK)
1490 return -1;
1491 if (nxtp)
1492 *nxtp = fh.ip6f_nxt;
1493 off += sizeof(struct ip6_frag);
1494 return off;
1495
1496 case IPPROTO_AH:
1497 if (m->m_pkthdr.len < off + sizeof(ip6e))
1498 return -1;
1499 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1500 if (nxtp)
1501 *nxtp = ip6e.ip6e_nxt;
1502 off += (ip6e.ip6e_len + 2) << 2;
1503 return off;
1504
1505 case IPPROTO_HOPOPTS:
1506 case IPPROTO_ROUTING:
1507 case IPPROTO_DSTOPTS:
1508 if (m->m_pkthdr.len < off + sizeof(ip6e))
1509 return -1;
1510 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1511 if (nxtp)
1512 *nxtp = ip6e.ip6e_nxt;
1513 off += (ip6e.ip6e_len + 1) << 3;
1514 return off;
1515
1516 case IPPROTO_NONE:
1517 case IPPROTO_ESP:
1518 case IPPROTO_IPCOMP:
1519 /* give up */
1520 return -1;
1521
1522 default:
1523 return -1;
1524 }
1525
1526 return -1;
1527 }
1528
1529 /*
1530 * get offset for the last header in the chain. m will be kept untainted.
1531 */
1532 int
1533 ip6_lasthdr(m, off, proto, nxtp)
1534 struct mbuf *m;
1535 int off;
1536 int proto;
1537 int *nxtp;
1538 {
1539 int newoff;
1540 int nxt;
1541
1542 if (!nxtp) {
1543 nxt = -1;
1544 nxtp = &nxt;
1545 }
1546 while (1) {
1547 newoff = ip6_nexthdr(m, off, proto, nxtp);
1548 if (newoff < 0)
1549 return off;
1550 else if (newoff < off)
1551 return -1; /* invalid */
1552 else if (newoff == off)
1553 return newoff;
1554
1555 off = newoff;
1556 proto = *nxtp;
1557 }
1558 }
1559
1560 struct ip6aux *
1561 ip6_addaux(m)
1562 struct mbuf *m;
1563 {
1564 struct m_tag *mtag;
1565
1566 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1567 if (!mtag) {
1568 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux),
1569 M_NOWAIT);
1570 if (mtag) {
1571 m_tag_prepend(m, mtag);
1572 bzero(mtag + 1, sizeof(struct ip6aux));
1573 }
1574 }
1575 return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1576 }
1577
1578 struct ip6aux *
1579 ip6_findaux(m)
1580 struct mbuf *m;
1581 {
1582 struct m_tag *mtag;
1583
1584 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1585 return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1586 }
1587
1588 void
1589 ip6_delaux(m)
1590 struct mbuf *m;
1591 {
1592 struct m_tag *mtag;
1593
1594 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1595 if (mtag)
1596 m_tag_delete(m, mtag);
1597 }
1598
1599 /*
1600 * System control for IP6
1601 */
1602
1603 u_char inet6ctlerrmap[PRC_NCMDS] = {
1604 0, 0, 0, 0,
1605 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1606 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1607 EMSGSIZE, EHOSTUNREACH, 0, 0,
1608 0, 0, 0, 0,
1609 ENOPROTOOPT
1610 };
Cache object: fca58adfe15160a87d9541e55946c388
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