1 /*-
2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $
30 */
31
32 /*-
33 * Copyright (c) 1982, 1986, 1988, 1993
34 * The Regents of the University of California. All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions
38 * are met:
39 * 1. Redistributions of source code must retain the above copyright
40 * notice, this list of conditions and the following disclaimer.
41 * 2. Redistributions in binary form must reproduce the above copyright
42 * notice, this list of conditions and the following disclaimer in the
43 * documentation and/or other materials provided with the distribution.
44 * 4. Neither the name of the University nor the names of its contributors
45 * may be used to endorse or promote products derived from this software
46 * without specific prior written permission.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 * SUCH DAMAGE.
59 *
60 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
61 */
62
63 #include <sys/cdefs.h>
64 __FBSDID("$FreeBSD$");
65
66 #include "opt_inet.h"
67 #include "opt_inet6.h"
68 #include "opt_ipsec.h"
69
70 #include <sys/param.h>
71 #include <sys/systm.h>
72 #include <sys/malloc.h>
73 #include <sys/mbuf.h>
74 #include <sys/proc.h>
75 #include <sys/domain.h>
76 #include <sys/protosw.h>
77 #include <sys/socket.h>
78 #include <sys/socketvar.h>
79 #include <sys/errno.h>
80 #include <sys/time.h>
81 #include <sys/kernel.h>
82 #include <sys/syslog.h>
83
84 #include <net/if.h>
85 #include <net/if_types.h>
86 #include <net/if_dl.h>
87 #include <net/route.h>
88 #include <net/netisr.h>
89 #include <net/pfil.h>
90
91 #include <netinet/in.h>
92 #include <netinet/in_systm.h>
93 #ifdef INET
94 #include <netinet/ip.h>
95 #include <netinet/ip_icmp.h>
96 #endif /* INET */
97 #include <netinet/ip6.h>
98 #include <netinet6/in6_var.h>
99 #include <netinet6/ip6_var.h>
100 #include <netinet/in_pcb.h>
101 #include <netinet/icmp6.h>
102 #include <netinet6/scope6_var.h>
103 #include <netinet6/in6_ifattach.h>
104 #include <netinet6/nd6.h>
105
106 #ifdef IPSEC
107 #include <netipsec/ipsec.h>
108 #include <netinet6/ip6_ipsec.h>
109 #include <netipsec/ipsec6.h>
110 #endif /* IPSEC */
111
112 #include <netinet6/ip6protosw.h>
113
114 extern struct domain inet6domain;
115
116 u_char ip6_protox[IPPROTO_MAX];
117 static struct ifqueue ip6intrq;
118 static int ip6qmaxlen = IFQ_MAXLEN;
119 struct in6_ifaddr *in6_ifaddr;
120
121 extern struct callout in6_tmpaddrtimer_ch;
122
123 int ip6_forward_srcrt; /* XXX */
124 int ip6_sourcecheck; /* XXX */
125 int ip6_sourcecheck_interval; /* XXX */
126
127 int ip6_ours_check_algorithm;
128
129 struct pfil_head inet6_pfil_hook;
130
131 struct ip6stat ip6stat;
132
133 static void ip6_init2(void *);
134 static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *);
135 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *);
136 #ifdef PULLDOWN_TEST
137 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int);
138 #endif
139
140 /*
141 * IP6 initialization: fill in IP6 protocol switch table.
142 * All protocols not implemented in kernel go to raw IP6 protocol handler.
143 */
144 void
145 ip6_init(void)
146 {
147 struct ip6protosw *pr;
148 int i;
149
150 #ifdef DIAGNOSTIC
151 if (sizeof(struct protosw) != sizeof(struct ip6protosw))
152 panic("sizeof(protosw) != sizeof(ip6protosw)");
153 #endif
154 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
155 if (pr == 0)
156 panic("ip6_init");
157
158 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
159 for (i = 0; i < IPPROTO_MAX; i++)
160 ip6_protox[i] = pr - inet6sw;
161 /*
162 * Cycle through IP protocols and put them into the appropriate place
163 * in ip6_protox[].
164 */
165 for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
166 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++)
167 if (pr->pr_domain->dom_family == PF_INET6 &&
168 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
169 /* Be careful to only index valid IP protocols. */
170 if (pr->pr_protocol < IPPROTO_MAX)
171 ip6_protox[pr->pr_protocol] = pr - inet6sw;
172 }
173
174 /* Initialize packet filter hooks. */
175 inet6_pfil_hook.ph_type = PFIL_TYPE_AF;
176 inet6_pfil_hook.ph_af = AF_INET6;
177 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0)
178 printf("%s: WARNING: unable to register pfil hook, "
179 "error %d\n", __func__, i);
180
181 ip6intrq.ifq_maxlen = ip6qmaxlen;
182 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF);
183 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0);
184 scope6_init();
185 addrsel_policy_init();
186 nd6_init();
187 frag6_init();
188 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR;
189 }
190
191 static void
192 ip6_init2(void *dummy)
193 {
194
195 /* nd6_timer_init */
196 callout_init(&nd6_timer_ch, 0);
197 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL);
198
199 /* timer for regeneranation of temporary addresses randomize ID */
200 callout_init(&in6_tmpaddrtimer_ch, 0);
201 callout_reset(&in6_tmpaddrtimer_ch,
202 (ip6_temp_preferred_lifetime - ip6_desync_factor -
203 ip6_temp_regen_advance) * hz,
204 in6_tmpaddrtimer, NULL);
205 }
206
207 /* cheat */
208 /* This must be after route_init(), which is now SI_ORDER_THIRD */
209 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL);
210
211 extern struct route_in6 ip6_forward_rt;
212
213 void
214 ip6_input(struct mbuf *m)
215 {
216 struct ip6_hdr *ip6;
217 int off = sizeof(struct ip6_hdr), nest;
218 u_int32_t plen;
219 u_int32_t rtalert = ~0;
220 int nxt, ours = 0;
221 struct ifnet *deliverifp = NULL;
222 struct in6_addr odst;
223 int srcrt = 0;
224
225 GIANT_REQUIRED; /* XXX for now */
226
227 #ifdef IPSEC
228 /*
229 * should the inner packet be considered authentic?
230 * see comment in ah4_input().
231 * NB: m cannot be NULL when passed to the input routine
232 */
233
234 m->m_flags &= ~M_AUTHIPHDR;
235 m->m_flags &= ~M_AUTHIPDGM;
236
237 #endif /* IPSEC */
238
239 /*
240 * make sure we don't have onion peering information into m_tag.
241 */
242 ip6_delaux(m);
243
244 /*
245 * mbuf statistics
246 */
247 if (m->m_flags & M_EXT) {
248 if (m->m_next)
249 ip6stat.ip6s_mext2m++;
250 else
251 ip6stat.ip6s_mext1++;
252 } else {
253 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0]))
254 if (m->m_next) {
255 if (m->m_flags & M_LOOP) {
256 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */
257 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX)
258 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++;
259 else
260 ip6stat.ip6s_m2m[0]++;
261 } else
262 ip6stat.ip6s_m1++;
263 #undef M2MMAX
264 }
265
266 /* drop the packet if IPv6 operation is disabled on the IF */
267 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) {
268 m_freem(m);
269 return;
270 }
271
272 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
273 ip6stat.ip6s_total++;
274
275 #ifndef PULLDOWN_TEST
276 /*
277 * L2 bridge code and some other code can return mbuf chain
278 * that does not conform to KAME requirement. too bad.
279 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram?
280 */
281 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) {
282 struct mbuf *n;
283
284 MGETHDR(n, M_DONTWAIT, MT_HEADER);
285 if (n)
286 M_MOVE_PKTHDR(n, m);
287 if (n && n->m_pkthdr.len > MHLEN) {
288 MCLGET(n, M_DONTWAIT);
289 if ((n->m_flags & M_EXT) == 0) {
290 m_freem(n);
291 n = NULL;
292 }
293 }
294 if (n == NULL) {
295 m_freem(m);
296 return; /* ENOBUFS */
297 }
298
299 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
300 n->m_len = n->m_pkthdr.len;
301 m_freem(m);
302 m = n;
303 }
304 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */);
305 #endif
306
307 if (m->m_len < sizeof(struct ip6_hdr)) {
308 struct ifnet *inifp;
309 inifp = m->m_pkthdr.rcvif;
310 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
311 ip6stat.ip6s_toosmall++;
312 in6_ifstat_inc(inifp, ifs6_in_hdrerr);
313 return;
314 }
315 }
316
317 ip6 = mtod(m, struct ip6_hdr *);
318
319 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
320 ip6stat.ip6s_badvers++;
321 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
322 goto bad;
323 }
324
325 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++;
326
327 /*
328 * Check against address spoofing/corruption.
329 */
330 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
331 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
332 /*
333 * XXX: "badscope" is not very suitable for a multicast source.
334 */
335 ip6stat.ip6s_badscope++;
336 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
337 goto bad;
338 }
339 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) &&
340 !(m->m_flags & M_LOOP)) {
341 /*
342 * In this case, the packet should come from the loopback
343 * interface. However, we cannot just check the if_flags,
344 * because ip6_mloopback() passes the "actual" interface
345 * as the outgoing/incoming interface.
346 */
347 ip6stat.ip6s_badscope++;
348 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
349 goto bad;
350 }
351
352 #ifdef ALTQ
353 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) {
354 /* packet is dropped by traffic conditioner */
355 return;
356 }
357 #endif
358 /*
359 * The following check is not documented in specs. A malicious
360 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
361 * and bypass security checks (act as if it was from 127.0.0.1 by using
362 * IPv6 src ::ffff:127.0.0.1). Be cautious.
363 *
364 * This check chokes if we are in an SIIT cloud. As none of BSDs
365 * support IPv4-less kernel compilation, we cannot support SIIT
366 * environment at all. So, it makes more sense for us to reject any
367 * malicious packets for non-SIIT environment, than try to do a
368 * partial support for SIIT environment.
369 */
370 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
371 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
372 ip6stat.ip6s_badscope++;
373 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
374 goto bad;
375 }
376 #if 0
377 /*
378 * Reject packets with IPv4 compatible addresses (auto tunnel).
379 *
380 * The code forbids auto tunnel relay case in RFC1933 (the check is
381 * stronger than RFC1933). We may want to re-enable it if mech-xx
382 * is revised to forbid relaying case.
383 */
384 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
385 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
386 ip6stat.ip6s_badscope++;
387 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
388 goto bad;
389 }
390 #endif
391
392 /*
393 * Run through list of hooks for input packets.
394 *
395 * NB: Beware of the destination address changing
396 * (e.g. by NAT rewriting). When this happens,
397 * tell ip6_forward to do the right thing.
398 */
399 odst = ip6->ip6_dst;
400
401 /* Jump over all PFIL processing if hooks are not active. */
402 if (!PFIL_HOOKED(&inet6_pfil_hook))
403 goto passin;
404
405 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL))
406 return;
407 if (m == NULL) /* consumed by filter */
408 return;
409 ip6 = mtod(m, struct ip6_hdr *);
410 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
411
412 passin:
413 /*
414 * Disambiguate address scope zones (if there is ambiguity).
415 * We first make sure that the original source or destination address
416 * is not in our internal form for scoped addresses. Such addresses
417 * are not necessarily invalid spec-wise, but we cannot accept them due
418 * to the usage conflict.
419 * in6_setscope() then also checks and rejects the cases where src or
420 * dst are the loopback address and the receiving interface
421 * is not loopback.
422 */
423 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) {
424 ip6stat.ip6s_badscope++; /* XXX */
425 goto bad;
426 }
427 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) ||
428 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) {
429 ip6stat.ip6s_badscope++;
430 goto bad;
431 }
432
433 /*
434 * Multicast check
435 */
436 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
437 struct in6_multi *in6m = 0;
438
439 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
440 /*
441 * See if we belong to the destination multicast group on the
442 * arrival interface.
443 */
444 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m);
445 if (in6m)
446 ours = 1;
447 else if (!ip6_mrouter) {
448 ip6stat.ip6s_notmember++;
449 ip6stat.ip6s_cantforward++;
450 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
451 goto bad;
452 }
453 deliverifp = m->m_pkthdr.rcvif;
454 goto hbhcheck;
455 }
456
457 /*
458 * Unicast check
459 */
460 if (ip6_forward_rt.ro_rt != NULL &&
461 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 &&
462 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
463 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr))
464 ip6stat.ip6s_forward_cachehit++;
465 else {
466 struct sockaddr_in6 *dst6;
467
468 if (ip6_forward_rt.ro_rt) {
469 /* route is down or destination is different */
470 ip6stat.ip6s_forward_cachemiss++;
471 RTFREE(ip6_forward_rt.ro_rt);
472 ip6_forward_rt.ro_rt = 0;
473 }
474
475 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6));
476 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst;
477 dst6->sin6_len = sizeof(struct sockaddr_in6);
478 dst6->sin6_family = AF_INET6;
479 dst6->sin6_addr = ip6->ip6_dst;
480
481 rtalloc((struct route *)&ip6_forward_rt);
482 }
483
484 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))
485
486 /*
487 * Accept the packet if the forwarding interface to the destination
488 * according to the routing table is the loopback interface,
489 * unless the associated route has a gateway.
490 * Note that this approach causes to accept a packet if there is a
491 * route to the loopback interface for the destination of the packet.
492 * But we think it's even useful in some situations, e.g. when using
493 * a special daemon which wants to intercept the packet.
494 *
495 * XXX: some OSes automatically make a cloned route for the destination
496 * of an outgoing packet. If the outgoing interface of the packet
497 * is a loopback one, the kernel would consider the packet to be
498 * accepted, even if we have no such address assinged on the interface.
499 * We check the cloned flag of the route entry to reject such cases,
500 * assuming that route entries for our own addresses are not made by
501 * cloning (it should be true because in6_addloop explicitly installs
502 * the host route). However, we might have to do an explicit check
503 * while it would be less efficient. Or, should we rather install a
504 * reject route for such a case?
505 */
506 if (ip6_forward_rt.ro_rt &&
507 (ip6_forward_rt.ro_rt->rt_flags &
508 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
509 #ifdef RTF_WASCLONED
510 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) &&
511 #endif
512 #ifdef RTF_CLONED
513 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) &&
514 #endif
515 #if 0
516 /*
517 * The check below is redundant since the comparison of
518 * the destination and the key of the rtentry has
519 * already done through looking up the routing table.
520 */
521 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
522 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr)
523 #endif
524 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) {
525 struct in6_ifaddr *ia6 =
526 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa;
527
528 /*
529 * record address information into m_tag.
530 */
531 (void)ip6_setdstifaddr(m, ia6);
532
533 /*
534 * packets to a tentative, duplicated, or somehow invalid
535 * address must not be accepted.
536 */
537 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
538 /* this address is ready */
539 ours = 1;
540 deliverifp = ia6->ia_ifp; /* correct? */
541 /* Count the packet in the ip address stats */
542 ia6->ia_ifa.if_ipackets++;
543 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
544 goto hbhcheck;
545 } else {
546 char ip6bufs[INET6_ADDRSTRLEN];
547 char ip6bufd[INET6_ADDRSTRLEN];
548 /* address is not ready, so discard the packet. */
549 nd6log((LOG_INFO,
550 "ip6_input: packet to an unready address %s->%s\n",
551 ip6_sprintf(ip6bufs, &ip6->ip6_src),
552 ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
553
554 goto bad;
555 }
556 }
557
558 /*
559 * FAITH (Firewall Aided Internet Translator)
560 */
561 if (ip6_keepfaith) {
562 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp
563 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) {
564 /* XXX do we need more sanity checks? */
565 ours = 1;
566 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */
567 goto hbhcheck;
568 }
569 }
570
571 /*
572 * Now there is no reason to process the packet if it's not our own
573 * and we're not a router.
574 */
575 if (!ip6_forwarding) {
576 ip6stat.ip6s_cantforward++;
577 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
578 goto bad;
579 }
580
581 hbhcheck:
582 /*
583 * record address information into m_tag, if we don't have one yet.
584 * note that we are unable to record it, if the address is not listed
585 * as our interface address (e.g. multicast addresses, addresses
586 * within FAITH prefixes and such).
587 */
588 if (deliverifp && !ip6_getdstifaddr(m)) {
589 struct in6_ifaddr *ia6;
590
591 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
592 if (ia6) {
593 if (!ip6_setdstifaddr(m, ia6)) {
594 /*
595 * XXX maybe we should drop the packet here,
596 * as we could not provide enough information
597 * to the upper layers.
598 */
599 }
600 }
601 }
602
603 /*
604 * Process Hop-by-Hop options header if it's contained.
605 * m may be modified in ip6_hopopts_input().
606 * If a JumboPayload option is included, plen will also be modified.
607 */
608 plen = (u_int32_t)ntohs(ip6->ip6_plen);
609 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
610 struct ip6_hbh *hbh;
611
612 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) {
613 #if 0 /*touches NULL pointer*/
614 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
615 #endif
616 return; /* m have already been freed */
617 }
618
619 /* adjust pointer */
620 ip6 = mtod(m, struct ip6_hdr *);
621
622 /*
623 * if the payload length field is 0 and the next header field
624 * indicates Hop-by-Hop Options header, then a Jumbo Payload
625 * option MUST be included.
626 */
627 if (ip6->ip6_plen == 0 && plen == 0) {
628 /*
629 * Note that if a valid jumbo payload option is
630 * contained, ip6_hopopts_input() must set a valid
631 * (non-zero) payload length to the variable plen.
632 */
633 ip6stat.ip6s_badoptions++;
634 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
635 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
636 icmp6_error(m, ICMP6_PARAM_PROB,
637 ICMP6_PARAMPROB_HEADER,
638 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
639 return;
640 }
641 #ifndef PULLDOWN_TEST
642 /* ip6_hopopts_input() ensures that mbuf is contiguous */
643 hbh = (struct ip6_hbh *)(ip6 + 1);
644 #else
645 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
646 sizeof(struct ip6_hbh));
647 if (hbh == NULL) {
648 ip6stat.ip6s_tooshort++;
649 return;
650 }
651 #endif
652 nxt = hbh->ip6h_nxt;
653
654 /*
655 * If we are acting as a router and the packet contains a
656 * router alert option, see if we know the option value.
657 * Currently, we only support the option value for MLD, in which
658 * case we should pass the packet to the multicast routing
659 * daemon.
660 */
661 if (rtalert != ~0 && ip6_forwarding) {
662 switch (rtalert) {
663 case IP6OPT_RTALERT_MLD:
664 ours = 1;
665 break;
666 default:
667 /*
668 * RFC2711 requires unrecognized values must be
669 * silently ignored.
670 */
671 break;
672 }
673 }
674 } else
675 nxt = ip6->ip6_nxt;
676
677 /*
678 * Check that the amount of data in the buffers
679 * is as at least much as the IPv6 header would have us expect.
680 * Trim mbufs if longer than we expect.
681 * Drop packet if shorter than we expect.
682 */
683 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
684 ip6stat.ip6s_tooshort++;
685 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
686 goto bad;
687 }
688 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
689 if (m->m_len == m->m_pkthdr.len) {
690 m->m_len = sizeof(struct ip6_hdr) + plen;
691 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
692 } else
693 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
694 }
695
696 /*
697 * Forward if desirable.
698 */
699 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
700 /*
701 * If we are acting as a multicast router, all
702 * incoming multicast packets are passed to the
703 * kernel-level multicast forwarding function.
704 * The packet is returned (relatively) intact; if
705 * ip6_mforward() returns a non-zero value, the packet
706 * must be discarded, else it may be accepted below.
707 */
708 if (ip6_mrouter && ip6_mforward &&
709 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
710 ip6stat.ip6s_cantforward++;
711 m_freem(m);
712 return;
713 }
714 if (!ours) {
715 m_freem(m);
716 return;
717 }
718 } else if (!ours) {
719 ip6_forward(m, srcrt);
720 return;
721 }
722
723 ip6 = mtod(m, struct ip6_hdr *);
724
725 /*
726 * Malicious party may be able to use IPv4 mapped addr to confuse
727 * tcp/udp stack and bypass security checks (act as if it was from
728 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious.
729 *
730 * For SIIT end node behavior, you may want to disable the check.
731 * However, you will become vulnerable to attacks using IPv4 mapped
732 * source.
733 */
734 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
735 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
736 ip6stat.ip6s_badscope++;
737 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
738 goto bad;
739 }
740
741 /*
742 * Tell launch routine the next header
743 */
744 ip6stat.ip6s_delivered++;
745 in6_ifstat_inc(deliverifp, ifs6_in_deliver);
746 nest = 0;
747
748 while (nxt != IPPROTO_DONE) {
749 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
750 ip6stat.ip6s_toomanyhdr++;
751 goto bad;
752 }
753
754 /*
755 * protection against faulty packet - there should be
756 * more sanity checks in header chain processing.
757 */
758 if (m->m_pkthdr.len < off) {
759 ip6stat.ip6s_tooshort++;
760 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
761 goto bad;
762 }
763
764 #ifdef IPSEC
765 /*
766 * enforce IPsec policy checking if we are seeing last header.
767 * note that we do not visit this with protocols with pcb layer
768 * code - like udp/tcp/raw ip.
769 */
770 if (ip6_ipsec_input(m, nxt))
771 goto bad;
772 #endif /* IPSEC */
773 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
774 }
775 return;
776 bad:
777 m_freem(m);
778 }
779
780 /*
781 * set/grab in6_ifaddr correspond to IPv6 destination address.
782 * XXX backward compatibility wrapper
783 */
784 static struct ip6aux *
785 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6)
786 {
787 struct ip6aux *ip6a;
788
789 ip6a = ip6_addaux(m);
790 if (ip6a)
791 ip6a->ip6a_dstia6 = ia6;
792 return ip6a; /* NULL if failed to set */
793 }
794
795 struct in6_ifaddr *
796 ip6_getdstifaddr(struct mbuf *m)
797 {
798 struct ip6aux *ip6a;
799
800 ip6a = ip6_findaux(m);
801 if (ip6a)
802 return ip6a->ip6a_dstia6;
803 else
804 return NULL;
805 }
806
807 /*
808 * Hop-by-Hop options header processing. If a valid jumbo payload option is
809 * included, the real payload length will be stored in plenp.
810 *
811 * rtalertp - XXX: should be stored more smart way
812 */
813 static int
814 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp,
815 struct mbuf **mp, int *offp)
816 {
817 struct mbuf *m = *mp;
818 int off = *offp, hbhlen;
819 struct ip6_hbh *hbh;
820 u_int8_t *opt;
821
822 /* validation of the length of the header */
823 #ifndef PULLDOWN_TEST
824 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1);
825 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
826 hbhlen = (hbh->ip6h_len + 1) << 3;
827
828 IP6_EXTHDR_CHECK(m, off, hbhlen, -1);
829 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
830 #else
831 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
832 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
833 if (hbh == NULL) {
834 ip6stat.ip6s_tooshort++;
835 return -1;
836 }
837 hbhlen = (hbh->ip6h_len + 1) << 3;
838 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
839 hbhlen);
840 if (hbh == NULL) {
841 ip6stat.ip6s_tooshort++;
842 return -1;
843 }
844 #endif
845 off += hbhlen;
846 hbhlen -= sizeof(struct ip6_hbh);
847 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh);
848
849 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
850 hbhlen, rtalertp, plenp) < 0)
851 return (-1);
852
853 *offp = off;
854 *mp = m;
855 return (0);
856 }
857
858 /*
859 * Search header for all Hop-by-hop options and process each option.
860 * This function is separate from ip6_hopopts_input() in order to
861 * handle a case where the sending node itself process its hop-by-hop
862 * options header. In such a case, the function is called from ip6_output().
863 *
864 * The function assumes that hbh header is located right after the IPv6 header
865 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
866 * opthead + hbhlen is located in continuous memory region.
867 */
868 int
869 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen,
870 u_int32_t *rtalertp, u_int32_t *plenp)
871 {
872 struct ip6_hdr *ip6;
873 int optlen = 0;
874 u_int8_t *opt = opthead;
875 u_int16_t rtalert_val;
876 u_int32_t jumboplen;
877 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
878
879 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
880 switch (*opt) {
881 case IP6OPT_PAD1:
882 optlen = 1;
883 break;
884 case IP6OPT_PADN:
885 if (hbhlen < IP6OPT_MINLEN) {
886 ip6stat.ip6s_toosmall++;
887 goto bad;
888 }
889 optlen = *(opt + 1) + 2;
890 break;
891 case IP6OPT_ROUTER_ALERT:
892 /* XXX may need check for alignment */
893 if (hbhlen < IP6OPT_RTALERT_LEN) {
894 ip6stat.ip6s_toosmall++;
895 goto bad;
896 }
897 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
898 /* XXX stat */
899 icmp6_error(m, ICMP6_PARAM_PROB,
900 ICMP6_PARAMPROB_HEADER,
901 erroff + opt + 1 - opthead);
902 return (-1);
903 }
904 optlen = IP6OPT_RTALERT_LEN;
905 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
906 *rtalertp = ntohs(rtalert_val);
907 break;
908 case IP6OPT_JUMBO:
909 /* XXX may need check for alignment */
910 if (hbhlen < IP6OPT_JUMBO_LEN) {
911 ip6stat.ip6s_toosmall++;
912 goto bad;
913 }
914 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
915 /* XXX stat */
916 icmp6_error(m, ICMP6_PARAM_PROB,
917 ICMP6_PARAMPROB_HEADER,
918 erroff + opt + 1 - opthead);
919 return (-1);
920 }
921 optlen = IP6OPT_JUMBO_LEN;
922
923 /*
924 * IPv6 packets that have non 0 payload length
925 * must not contain a jumbo payload option.
926 */
927 ip6 = mtod(m, struct ip6_hdr *);
928 if (ip6->ip6_plen) {
929 ip6stat.ip6s_badoptions++;
930 icmp6_error(m, ICMP6_PARAM_PROB,
931 ICMP6_PARAMPROB_HEADER,
932 erroff + opt - opthead);
933 return (-1);
934 }
935
936 /*
937 * We may see jumbolen in unaligned location, so
938 * we'd need to perform bcopy().
939 */
940 bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
941 jumboplen = (u_int32_t)htonl(jumboplen);
942
943 #if 1
944 /*
945 * if there are multiple jumbo payload options,
946 * *plenp will be non-zero and the packet will be
947 * rejected.
948 * the behavior may need some debate in ipngwg -
949 * multiple options does not make sense, however,
950 * there's no explicit mention in specification.
951 */
952 if (*plenp != 0) {
953 ip6stat.ip6s_badoptions++;
954 icmp6_error(m, ICMP6_PARAM_PROB,
955 ICMP6_PARAMPROB_HEADER,
956 erroff + opt + 2 - opthead);
957 return (-1);
958 }
959 #endif
960
961 /*
962 * jumbo payload length must be larger than 65535.
963 */
964 if (jumboplen <= IPV6_MAXPACKET) {
965 ip6stat.ip6s_badoptions++;
966 icmp6_error(m, ICMP6_PARAM_PROB,
967 ICMP6_PARAMPROB_HEADER,
968 erroff + opt + 2 - opthead);
969 return (-1);
970 }
971 *plenp = jumboplen;
972
973 break;
974 default: /* unknown option */
975 if (hbhlen < IP6OPT_MINLEN) {
976 ip6stat.ip6s_toosmall++;
977 goto bad;
978 }
979 optlen = ip6_unknown_opt(opt, m,
980 erroff + opt - opthead);
981 if (optlen == -1)
982 return (-1);
983 optlen += 2;
984 break;
985 }
986 }
987
988 return (0);
989
990 bad:
991 m_freem(m);
992 return (-1);
993 }
994
995 /*
996 * Unknown option processing.
997 * The third argument `off' is the offset from the IPv6 header to the option,
998 * which is necessary if the IPv6 header the and option header and IPv6 header
999 * is not continuous in order to return an ICMPv6 error.
1000 */
1001 int
1002 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off)
1003 {
1004 struct ip6_hdr *ip6;
1005
1006 switch (IP6OPT_TYPE(*optp)) {
1007 case IP6OPT_TYPE_SKIP: /* ignore the option */
1008 return ((int)*(optp + 1));
1009 case IP6OPT_TYPE_DISCARD: /* silently discard */
1010 m_freem(m);
1011 return (-1);
1012 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
1013 ip6stat.ip6s_badoptions++;
1014 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
1015 return (-1);
1016 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
1017 ip6stat.ip6s_badoptions++;
1018 ip6 = mtod(m, struct ip6_hdr *);
1019 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
1020 (m->m_flags & (M_BCAST|M_MCAST)))
1021 m_freem(m);
1022 else
1023 icmp6_error(m, ICMP6_PARAM_PROB,
1024 ICMP6_PARAMPROB_OPTION, off);
1025 return (-1);
1026 }
1027
1028 m_freem(m); /* XXX: NOTREACHED */
1029 return (-1);
1030 }
1031
1032 /*
1033 * Create the "control" list for this pcb.
1034 * These functions will not modify mbuf chain at all.
1035 *
1036 * With KAME mbuf chain restriction:
1037 * The routine will be called from upper layer handlers like tcp6_input().
1038 * Thus the routine assumes that the caller (tcp6_input) have already
1039 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the
1040 * very first mbuf on the mbuf chain.
1041 *
1042 * ip6_savecontrol_v4 will handle those options that are possible to be
1043 * set on a v4-mapped socket.
1044 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those
1045 * options and handle the v6-only ones itself.
1046 */
1047 struct mbuf **
1048 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp,
1049 int *v4only)
1050 {
1051 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1052
1053 #ifdef SO_TIMESTAMP
1054 if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) {
1055 struct timeval tv;
1056
1057 microtime(&tv);
1058 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1059 SCM_TIMESTAMP, SOL_SOCKET);
1060 if (*mp)
1061 mp = &(*mp)->m_next;
1062 }
1063 #endif
1064
1065 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1066 if (v4only != NULL)
1067 *v4only = 1;
1068 return (mp);
1069 }
1070
1071 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y))
1072 /* RFC 2292 sec. 5 */
1073 if ((inp->inp_flags & IN6P_PKTINFO) != 0) {
1074 struct in6_pktinfo pi6;
1075
1076 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
1077 in6_clearscope(&pi6.ipi6_addr); /* XXX */
1078 pi6.ipi6_ifindex =
1079 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0;
1080
1081 *mp = sbcreatecontrol((caddr_t) &pi6,
1082 sizeof(struct in6_pktinfo),
1083 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6);
1084 if (*mp)
1085 mp = &(*mp)->m_next;
1086 }
1087
1088 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) {
1089 int hlim = ip6->ip6_hlim & 0xff;
1090
1091 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int),
1092 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT),
1093 IPPROTO_IPV6);
1094 if (*mp)
1095 mp = &(*mp)->m_next;
1096 }
1097
1098 if (v4only != NULL)
1099 *v4only = 0;
1100 return (mp);
1101 }
1102
1103 void
1104 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp)
1105 {
1106 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1107 int v4only = 0;
1108
1109 mp = ip6_savecontrol_v4(in6p, m, mp, &v4only);
1110 if (v4only)
1111 return;
1112
1113 if ((in6p->in6p_flags & IN6P_TCLASS) != 0) {
1114 u_int32_t flowinfo;
1115 int tclass;
1116
1117 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
1118 flowinfo >>= 20;
1119
1120 tclass = flowinfo & 0xff;
1121 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass),
1122 IPV6_TCLASS, IPPROTO_IPV6);
1123 if (*mp)
1124 mp = &(*mp)->m_next;
1125 }
1126
1127 /*
1128 * IPV6_HOPOPTS socket option. Recall that we required super-user
1129 * privilege for the option (see ip6_ctloutput), but it might be too
1130 * strict, since there might be some hop-by-hop options which can be
1131 * returned to normal user.
1132 * See also RFC 2292 section 6 (or RFC 3542 section 8).
1133 */
1134 if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) {
1135 /*
1136 * Check if a hop-by-hop options header is contatined in the
1137 * received packet, and if so, store the options as ancillary
1138 * data. Note that a hop-by-hop options header must be
1139 * just after the IPv6 header, which is assured through the
1140 * IPv6 input processing.
1141 */
1142 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
1143 struct ip6_hbh *hbh;
1144 int hbhlen = 0;
1145 #ifdef PULLDOWN_TEST
1146 struct mbuf *ext;
1147 #endif
1148
1149 #ifndef PULLDOWN_TEST
1150 hbh = (struct ip6_hbh *)(ip6 + 1);
1151 hbhlen = (hbh->ip6h_len + 1) << 3;
1152 #else
1153 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
1154 ip6->ip6_nxt);
1155 if (ext == NULL) {
1156 ip6stat.ip6s_tooshort++;
1157 return;
1158 }
1159 hbh = mtod(ext, struct ip6_hbh *);
1160 hbhlen = (hbh->ip6h_len + 1) << 3;
1161 if (hbhlen != ext->m_len) {
1162 m_freem(ext);
1163 ip6stat.ip6s_tooshort++;
1164 return;
1165 }
1166 #endif
1167
1168 /*
1169 * XXX: We copy the whole header even if a
1170 * jumbo payload option is included, the option which
1171 * is to be removed before returning according to
1172 * RFC2292.
1173 * Note: this constraint is removed in RFC3542
1174 */
1175 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
1176 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS),
1177 IPPROTO_IPV6);
1178 if (*mp)
1179 mp = &(*mp)->m_next;
1180 #ifdef PULLDOWN_TEST
1181 m_freem(ext);
1182 #endif
1183 }
1184 }
1185
1186 if ((in6p->in6p_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) {
1187 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
1188
1189 /*
1190 * Search for destination options headers or routing
1191 * header(s) through the header chain, and stores each
1192 * header as ancillary data.
1193 * Note that the order of the headers remains in
1194 * the chain of ancillary data.
1195 */
1196 while (1) { /* is explicit loop prevention necessary? */
1197 struct ip6_ext *ip6e = NULL;
1198 int elen;
1199 #ifdef PULLDOWN_TEST
1200 struct mbuf *ext = NULL;
1201 #endif
1202
1203 /*
1204 * if it is not an extension header, don't try to
1205 * pull it from the chain.
1206 */
1207 switch (nxt) {
1208 case IPPROTO_DSTOPTS:
1209 case IPPROTO_ROUTING:
1210 case IPPROTO_HOPOPTS:
1211 case IPPROTO_AH: /* is it possible? */
1212 break;
1213 default:
1214 goto loopend;
1215 }
1216
1217 #ifndef PULLDOWN_TEST
1218 if (off + sizeof(*ip6e) > m->m_len)
1219 goto loopend;
1220 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
1221 if (nxt == IPPROTO_AH)
1222 elen = (ip6e->ip6e_len + 2) << 2;
1223 else
1224 elen = (ip6e->ip6e_len + 1) << 3;
1225 if (off + elen > m->m_len)
1226 goto loopend;
1227 #else
1228 ext = ip6_pullexthdr(m, off, nxt);
1229 if (ext == NULL) {
1230 ip6stat.ip6s_tooshort++;
1231 return;
1232 }
1233 ip6e = mtod(ext, struct ip6_ext *);
1234 if (nxt == IPPROTO_AH)
1235 elen = (ip6e->ip6e_len + 2) << 2;
1236 else
1237 elen = (ip6e->ip6e_len + 1) << 3;
1238 if (elen != ext->m_len) {
1239 m_freem(ext);
1240 ip6stat.ip6s_tooshort++;
1241 return;
1242 }
1243 #endif
1244
1245 switch (nxt) {
1246 case IPPROTO_DSTOPTS:
1247 if (!(in6p->in6p_flags & IN6P_DSTOPTS))
1248 break;
1249
1250 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1251 IS2292(in6p,
1252 IPV6_2292DSTOPTS, IPV6_DSTOPTS),
1253 IPPROTO_IPV6);
1254 if (*mp)
1255 mp = &(*mp)->m_next;
1256 break;
1257 case IPPROTO_ROUTING:
1258 if (!in6p->in6p_flags & IN6P_RTHDR)
1259 break;
1260
1261 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1262 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR),
1263 IPPROTO_IPV6);
1264 if (*mp)
1265 mp = &(*mp)->m_next;
1266 break;
1267 case IPPROTO_HOPOPTS:
1268 case IPPROTO_AH: /* is it possible? */
1269 break;
1270
1271 default:
1272 /*
1273 * other cases have been filtered in the above.
1274 * none will visit this case. here we supply
1275 * the code just in case (nxt overwritten or
1276 * other cases).
1277 */
1278 #ifdef PULLDOWN_TEST
1279 m_freem(ext);
1280 #endif
1281 goto loopend;
1282
1283 }
1284
1285 /* proceed with the next header. */
1286 off += elen;
1287 nxt = ip6e->ip6e_nxt;
1288 ip6e = NULL;
1289 #ifdef PULLDOWN_TEST
1290 m_freem(ext);
1291 ext = NULL;
1292 #endif
1293 }
1294 loopend:
1295 ;
1296 }
1297 }
1298 #undef IS2292
1299
1300 void
1301 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu)
1302 {
1303 struct socket *so;
1304 struct mbuf *m_mtu;
1305 struct ip6_mtuinfo mtuctl;
1306
1307 so = in6p->inp_socket;
1308
1309 if (mtu == NULL)
1310 return;
1311
1312 #ifdef DIAGNOSTIC
1313 if (so == NULL) /* I believe this is impossible */
1314 panic("ip6_notify_pmtu: socket is NULL");
1315 #endif
1316
1317 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */
1318 mtuctl.ip6m_mtu = *mtu;
1319 mtuctl.ip6m_addr = *dst;
1320 if (sa6_recoverscope(&mtuctl.ip6m_addr))
1321 return;
1322
1323 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl),
1324 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL)
1325 return;
1326
1327 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu)
1328 == 0) {
1329 m_freem(m_mtu);
1330 /* XXX: should count statistics */
1331 } else
1332 sorwakeup(so);
1333
1334 return;
1335 }
1336
1337 #ifdef PULLDOWN_TEST
1338 /*
1339 * pull single extension header from mbuf chain. returns single mbuf that
1340 * contains the result, or NULL on error.
1341 */
1342 static struct mbuf *
1343 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt)
1344 {
1345 struct ip6_ext ip6e;
1346 size_t elen;
1347 struct mbuf *n;
1348
1349 #ifdef DIAGNOSTIC
1350 switch (nxt) {
1351 case IPPROTO_DSTOPTS:
1352 case IPPROTO_ROUTING:
1353 case IPPROTO_HOPOPTS:
1354 case IPPROTO_AH: /* is it possible? */
1355 break;
1356 default:
1357 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
1358 }
1359 #endif
1360
1361 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1362 if (nxt == IPPROTO_AH)
1363 elen = (ip6e.ip6e_len + 2) << 2;
1364 else
1365 elen = (ip6e.ip6e_len + 1) << 3;
1366
1367 MGET(n, M_DONTWAIT, MT_DATA);
1368 if (n && elen >= MLEN) {
1369 MCLGET(n, M_DONTWAIT);
1370 if ((n->m_flags & M_EXT) == 0) {
1371 m_free(n);
1372 n = NULL;
1373 }
1374 }
1375 if (!n)
1376 return NULL;
1377
1378 n->m_len = 0;
1379 if (elen >= M_TRAILINGSPACE(n)) {
1380 m_free(n);
1381 return NULL;
1382 }
1383
1384 m_copydata(m, off, elen, mtod(n, caddr_t));
1385 n->m_len = elen;
1386 return n;
1387 }
1388 #endif
1389
1390 /*
1391 * Get pointer to the previous header followed by the header
1392 * currently processed.
1393 * XXX: This function supposes that
1394 * M includes all headers,
1395 * the next header field and the header length field of each header
1396 * are valid, and
1397 * the sum of each header length equals to OFF.
1398 * Because of these assumptions, this function must be called very
1399 * carefully. Moreover, it will not be used in the near future when
1400 * we develop `neater' mechanism to process extension headers.
1401 */
1402 char *
1403 ip6_get_prevhdr(struct mbuf *m, int off)
1404 {
1405 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1406
1407 if (off == sizeof(struct ip6_hdr))
1408 return (&ip6->ip6_nxt);
1409 else {
1410 int len, nxt;
1411 struct ip6_ext *ip6e = NULL;
1412
1413 nxt = ip6->ip6_nxt;
1414 len = sizeof(struct ip6_hdr);
1415 while (len < off) {
1416 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);
1417
1418 switch (nxt) {
1419 case IPPROTO_FRAGMENT:
1420 len += sizeof(struct ip6_frag);
1421 break;
1422 case IPPROTO_AH:
1423 len += (ip6e->ip6e_len + 2) << 2;
1424 break;
1425 default:
1426 len += (ip6e->ip6e_len + 1) << 3;
1427 break;
1428 }
1429 nxt = ip6e->ip6e_nxt;
1430 }
1431 if (ip6e)
1432 return (&ip6e->ip6e_nxt);
1433 else
1434 return NULL;
1435 }
1436 }
1437
1438 /*
1439 * get next header offset. m will be retained.
1440 */
1441 int
1442 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp)
1443 {
1444 struct ip6_hdr ip6;
1445 struct ip6_ext ip6e;
1446 struct ip6_frag fh;
1447
1448 /* just in case */
1449 if (m == NULL)
1450 panic("ip6_nexthdr: m == NULL");
1451 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
1452 return -1;
1453
1454 switch (proto) {
1455 case IPPROTO_IPV6:
1456 if (m->m_pkthdr.len < off + sizeof(ip6))
1457 return -1;
1458 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
1459 if (nxtp)
1460 *nxtp = ip6.ip6_nxt;
1461 off += sizeof(ip6);
1462 return off;
1463
1464 case IPPROTO_FRAGMENT:
1465 /*
1466 * terminate parsing if it is not the first fragment,
1467 * it does not make sense to parse through it.
1468 */
1469 if (m->m_pkthdr.len < off + sizeof(fh))
1470 return -1;
1471 m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
1472 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */
1473 if (fh.ip6f_offlg & IP6F_OFF_MASK)
1474 return -1;
1475 if (nxtp)
1476 *nxtp = fh.ip6f_nxt;
1477 off += sizeof(struct ip6_frag);
1478 return off;
1479
1480 case IPPROTO_AH:
1481 if (m->m_pkthdr.len < off + sizeof(ip6e))
1482 return -1;
1483 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1484 if (nxtp)
1485 *nxtp = ip6e.ip6e_nxt;
1486 off += (ip6e.ip6e_len + 2) << 2;
1487 return off;
1488
1489 case IPPROTO_HOPOPTS:
1490 case IPPROTO_ROUTING:
1491 case IPPROTO_DSTOPTS:
1492 if (m->m_pkthdr.len < off + sizeof(ip6e))
1493 return -1;
1494 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1495 if (nxtp)
1496 *nxtp = ip6e.ip6e_nxt;
1497 off += (ip6e.ip6e_len + 1) << 3;
1498 return off;
1499
1500 case IPPROTO_NONE:
1501 case IPPROTO_ESP:
1502 case IPPROTO_IPCOMP:
1503 /* give up */
1504 return -1;
1505
1506 default:
1507 return -1;
1508 }
1509
1510 return -1;
1511 }
1512
1513 /*
1514 * get offset for the last header in the chain. m will be kept untainted.
1515 */
1516 int
1517 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp)
1518 {
1519 int newoff;
1520 int nxt;
1521
1522 if (!nxtp) {
1523 nxt = -1;
1524 nxtp = &nxt;
1525 }
1526 while (1) {
1527 newoff = ip6_nexthdr(m, off, proto, nxtp);
1528 if (newoff < 0)
1529 return off;
1530 else if (newoff < off)
1531 return -1; /* invalid */
1532 else if (newoff == off)
1533 return newoff;
1534
1535 off = newoff;
1536 proto = *nxtp;
1537 }
1538 }
1539
1540 struct ip6aux *
1541 ip6_addaux(struct mbuf *m)
1542 {
1543 struct m_tag *mtag;
1544
1545 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1546 if (!mtag) {
1547 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux),
1548 M_NOWAIT);
1549 if (mtag) {
1550 m_tag_prepend(m, mtag);
1551 bzero(mtag + 1, sizeof(struct ip6aux));
1552 }
1553 }
1554 return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1555 }
1556
1557 struct ip6aux *
1558 ip6_findaux(struct mbuf *m)
1559 {
1560 struct m_tag *mtag;
1561
1562 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1563 return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1564 }
1565
1566 void
1567 ip6_delaux(struct mbuf *m)
1568 {
1569 struct m_tag *mtag;
1570
1571 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1572 if (mtag)
1573 m_tag_delete(m, mtag);
1574 }
1575
1576 /*
1577 * System control for IP6
1578 */
1579
1580 u_char inet6ctlerrmap[PRC_NCMDS] = {
1581 0, 0, 0, 0,
1582 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1583 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1584 EMSGSIZE, EHOSTUNREACH, 0, 0,
1585 0, 0, 0, 0,
1586 ENOPROTOOPT
1587 };
Cache object: 50c62c61534983d52b86d50039c3f186
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