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: releng/7.4/sys/netinet6/ip6_input.c 215368 2010-11-16 04:40:03Z sobomax $");
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 struct in6_ifaddr *in6_ifaddr;
119
120 extern struct callout in6_tmpaddrtimer_ch;
121
122 struct pfil_head inet6_pfil_hook;
123
124 struct ip6stat ip6stat;
125
126 static void ip6_init2(void *);
127 static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *);
128 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *);
129 #ifdef PULLDOWN_TEST
130 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int);
131 #endif
132
133 /*
134 * IP6 initialization: fill in IP6 protocol switch table.
135 * All protocols not implemented in kernel go to raw IP6 protocol handler.
136 */
137 void
138 ip6_init(void)
139 {
140 struct ip6protosw *pr;
141 int i;
142
143 #ifdef DIAGNOSTIC
144 if (sizeof(struct protosw) != sizeof(struct ip6protosw))
145 panic("sizeof(protosw) != sizeof(ip6protosw)");
146 #endif
147 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
148 if (pr == NULL)
149 panic("ip6_init");
150
151 /* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */
152 for (i = 0; i < IPPROTO_MAX; i++)
153 ip6_protox[i] = pr - inet6sw;
154 /*
155 * Cycle through IP protocols and put them into the appropriate place
156 * in ip6_protox[].
157 */
158 for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
159 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++)
160 if (pr->pr_domain->dom_family == PF_INET6 &&
161 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
162 /* Be careful to only index valid IP protocols. */
163 if (pr->pr_protocol < IPPROTO_MAX)
164 ip6_protox[pr->pr_protocol] = pr - inet6sw;
165 }
166
167 /* Initialize packet filter hooks. */
168 inet6_pfil_hook.ph_type = PFIL_TYPE_AF;
169 inet6_pfil_hook.ph_af = AF_INET6;
170 if ((i = pfil_head_register(&inet6_pfil_hook)) != 0)
171 printf("%s: WARNING: unable to register pfil hook, "
172 "error %d\n", __func__, i);
173
174 ip6intrq.ifq_maxlen = ifqmaxlen;
175 mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF);
176 netisr_register(NETISR_IPV6, ip6_input, &ip6intrq, 0);
177 scope6_init();
178 addrsel_policy_init();
179 nd6_init();
180 frag6_init();
181 ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR;
182 }
183
184 /*
185 * The protocol to be inserted into ip6_protox[] must be already registered
186 * in inet6sw[], either statically or through pf_proto_register().
187 */
188 int
189 ip6proto_register(short ip6proto)
190 {
191 struct ip6protosw *pr;
192
193 /* Sanity checks. */
194 if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX)
195 return (EPROTONOSUPPORT);
196
197 /*
198 * The protocol slot must not be occupied by another protocol
199 * already. An index pointing to IPPROTO_RAW is unused.
200 */
201 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
202 if (pr == NULL)
203 return (EPFNOSUPPORT);
204 if (ip6_protox[ip6proto] != pr - inet6sw) /* IPPROTO_RAW */
205 return (EEXIST);
206
207 /*
208 * Find the protocol position in inet6sw[] and set the index.
209 */
210 for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
211 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) {
212 if (pr->pr_domain->dom_family == PF_INET6 &&
213 pr->pr_protocol && pr->pr_protocol == ip6proto) {
214 ip6_protox[pr->pr_protocol] = pr - inet6sw;
215 return (0);
216 }
217 }
218 return (EPROTONOSUPPORT);
219 }
220
221 int
222 ip6proto_unregister(short ip6proto)
223 {
224 struct ip6protosw *pr;
225
226 /* Sanity checks. */
227 if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX)
228 return (EPROTONOSUPPORT);
229
230 /* Check if the protocol was indeed registered. */
231 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
232 if (pr == NULL)
233 return (EPFNOSUPPORT);
234 if (ip6_protox[ip6proto] == pr - inet6sw) /* IPPROTO_RAW */
235 return (ENOENT);
236
237 /* Reset the protocol slot to IPPROTO_RAW. */
238 ip6_protox[ip6proto] = pr - inet6sw;
239 return (0);
240 }
241
242 static void
243 ip6_init2(void *dummy)
244 {
245
246 /* nd6_timer_init */
247 callout_init(&nd6_timer_ch, 0);
248 callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL);
249
250 /* timer for regeneranation of temporary addresses randomize ID */
251 callout_init(&in6_tmpaddrtimer_ch, 0);
252 callout_reset(&in6_tmpaddrtimer_ch,
253 (ip6_temp_preferred_lifetime - ip6_desync_factor -
254 ip6_temp_regen_advance) * hz,
255 in6_tmpaddrtimer, NULL);
256 }
257
258 /* cheat */
259 /* This must be after route_init(), which is now SI_ORDER_THIRD */
260 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL);
261
262 extern struct route_in6 ip6_forward_rt;
263
264 void
265 ip6_input(struct mbuf *m)
266 {
267 struct ip6_hdr *ip6;
268 int off = sizeof(struct ip6_hdr), nest;
269 u_int32_t plen;
270 u_int32_t rtalert = ~0;
271 int nxt, ours = 0;
272 struct ifnet *deliverifp = NULL;
273 struct in6_addr odst;
274 int srcrt = 0;
275
276 GIANT_REQUIRED; /* XXX for now */
277
278 #ifdef IPSEC
279 /*
280 * should the inner packet be considered authentic?
281 * see comment in ah4_input().
282 * NB: m cannot be NULL when passed to the input routine
283 */
284
285 m->m_flags &= ~M_AUTHIPHDR;
286 m->m_flags &= ~M_AUTHIPDGM;
287
288 #endif /* IPSEC */
289
290 /*
291 * make sure we don't have onion peering information into m_tag.
292 */
293 ip6_delaux(m);
294
295 /*
296 * mbuf statistics
297 */
298 if (m->m_flags & M_EXT) {
299 if (m->m_next)
300 ip6stat.ip6s_mext2m++;
301 else
302 ip6stat.ip6s_mext1++;
303 } else {
304 #define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0]))
305 if (m->m_next) {
306 if (m->m_flags & M_LOOP) {
307 ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */
308 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX)
309 ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++;
310 else
311 ip6stat.ip6s_m2m[0]++;
312 } else
313 ip6stat.ip6s_m1++;
314 #undef M2MMAX
315 }
316
317 /* drop the packet if IPv6 operation is disabled on the IF */
318 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) {
319 m_freem(m);
320 return;
321 }
322
323 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
324 ip6stat.ip6s_total++;
325
326 #ifndef PULLDOWN_TEST
327 /*
328 * L2 bridge code and some other code can return mbuf chain
329 * that does not conform to KAME requirement. too bad.
330 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram?
331 */
332 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) {
333 struct mbuf *n;
334
335 MGETHDR(n, M_DONTWAIT, MT_HEADER);
336 if (n)
337 M_MOVE_PKTHDR(n, m);
338 if (n && n->m_pkthdr.len > MHLEN) {
339 MCLGET(n, M_DONTWAIT);
340 if ((n->m_flags & M_EXT) == 0) {
341 m_freem(n);
342 n = NULL;
343 }
344 }
345 if (n == NULL) {
346 m_freem(m);
347 return; /* ENOBUFS */
348 }
349
350 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
351 n->m_len = n->m_pkthdr.len;
352 m_freem(m);
353 m = n;
354 }
355 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */);
356 #endif
357
358 if (m->m_len < sizeof(struct ip6_hdr)) {
359 struct ifnet *inifp;
360 inifp = m->m_pkthdr.rcvif;
361 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
362 ip6stat.ip6s_toosmall++;
363 in6_ifstat_inc(inifp, ifs6_in_hdrerr);
364 return;
365 }
366 }
367
368 ip6 = mtod(m, struct ip6_hdr *);
369
370 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
371 ip6stat.ip6s_badvers++;
372 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
373 goto bad;
374 }
375
376 ip6stat.ip6s_nxthist[ip6->ip6_nxt]++;
377
378 /*
379 * Check against address spoofing/corruption.
380 */
381 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
382 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
383 /*
384 * XXX: "badscope" is not very suitable for a multicast source.
385 */
386 ip6stat.ip6s_badscope++;
387 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
388 goto bad;
389 }
390 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) &&
391 !(m->m_flags & M_LOOP)) {
392 /*
393 * In this case, the packet should come from the loopback
394 * interface. However, we cannot just check the if_flags,
395 * because ip6_mloopback() passes the "actual" interface
396 * as the outgoing/incoming interface.
397 */
398 ip6stat.ip6s_badscope++;
399 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
400 goto bad;
401 }
402
403 #ifdef ALTQ
404 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) {
405 /* packet is dropped by traffic conditioner */
406 return;
407 }
408 #endif
409 /*
410 * The following check is not documented in specs. A malicious
411 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
412 * and bypass security checks (act as if it was from 127.0.0.1 by using
413 * IPv6 src ::ffff:127.0.0.1). Be cautious.
414 *
415 * This check chokes if we are in an SIIT cloud. As none of BSDs
416 * support IPv4-less kernel compilation, we cannot support SIIT
417 * environment at all. So, it makes more sense for us to reject any
418 * malicious packets for non-SIIT environment, than try to do a
419 * partial support for SIIT environment.
420 */
421 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
422 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
423 ip6stat.ip6s_badscope++;
424 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
425 goto bad;
426 }
427 #if 0
428 /*
429 * Reject packets with IPv4 compatible addresses (auto tunnel).
430 *
431 * The code forbids auto tunnel relay case in RFC1933 (the check is
432 * stronger than RFC1933). We may want to re-enable it if mech-xx
433 * is revised to forbid relaying case.
434 */
435 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
436 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
437 ip6stat.ip6s_badscope++;
438 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
439 goto bad;
440 }
441 #endif
442
443 /*
444 * Run through list of hooks for input packets.
445 *
446 * NB: Beware of the destination address changing
447 * (e.g. by NAT rewriting). When this happens,
448 * tell ip6_forward to do the right thing.
449 */
450 odst = ip6->ip6_dst;
451
452 /* Jump over all PFIL processing if hooks are not active. */
453 if (!PFIL_HOOKED(&inet6_pfil_hook))
454 goto passin;
455
456 if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif, PFIL_IN, NULL))
457 return;
458 if (m == NULL) /* consumed by filter */
459 return;
460 ip6 = mtod(m, struct ip6_hdr *);
461 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
462
463 passin:
464 /*
465 * Disambiguate address scope zones (if there is ambiguity).
466 * We first make sure that the original source or destination address
467 * is not in our internal form for scoped addresses. Such addresses
468 * are not necessarily invalid spec-wise, but we cannot accept them due
469 * to the usage conflict.
470 * in6_setscope() then also checks and rejects the cases where src or
471 * dst are the loopback address and the receiving interface
472 * is not loopback.
473 */
474 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) {
475 ip6stat.ip6s_badscope++; /* XXX */
476 goto bad;
477 }
478 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) ||
479 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) {
480 ip6stat.ip6s_badscope++;
481 goto bad;
482 }
483
484 /*
485 * Multicast check
486 */
487 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
488 struct in6_multi *in6m = 0;
489
490 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
491 /*
492 * See if we belong to the destination multicast group on the
493 * arrival interface.
494 */
495 IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m);
496 if (in6m)
497 ours = 1;
498 else if (!ip6_mrouter) {
499 ip6stat.ip6s_notmember++;
500 ip6stat.ip6s_cantforward++;
501 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
502 goto bad;
503 }
504 deliverifp = m->m_pkthdr.rcvif;
505 goto hbhcheck;
506 }
507
508 /*
509 * Unicast check
510 */
511 if (ip6_forward_rt.ro_rt != NULL &&
512 (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 &&
513 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
514 &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr))
515 ip6stat.ip6s_forward_cachehit++;
516 else {
517 struct sockaddr_in6 *dst6;
518
519 if (ip6_forward_rt.ro_rt) {
520 /* route is down or destination is different */
521 ip6stat.ip6s_forward_cachemiss++;
522 RTFREE(ip6_forward_rt.ro_rt);
523 ip6_forward_rt.ro_rt = 0;
524 }
525
526 bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6));
527 dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst;
528 dst6->sin6_len = sizeof(struct sockaddr_in6);
529 dst6->sin6_family = AF_INET6;
530 dst6->sin6_addr = ip6->ip6_dst;
531
532 rtalloc((struct route *)&ip6_forward_rt);
533 }
534
535 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))
536
537 /*
538 * Accept the packet if the forwarding interface to the destination
539 * according to the routing table is the loopback interface,
540 * unless the associated route has a gateway.
541 * Note that this approach causes to accept a packet if there is a
542 * route to the loopback interface for the destination of the packet.
543 * But we think it's even useful in some situations, e.g. when using
544 * a special daemon which wants to intercept the packet.
545 *
546 * XXX: some OSes automatically make a cloned route for the destination
547 * of an outgoing packet. If the outgoing interface of the packet
548 * is a loopback one, the kernel would consider the packet to be
549 * accepted, even if we have no such address assinged on the interface.
550 * We check the cloned flag of the route entry to reject such cases,
551 * assuming that route entries for our own addresses are not made by
552 * cloning (it should be true because in6_addloop explicitly installs
553 * the host route). However, we might have to do an explicit check
554 * while it would be less efficient. Or, should we rather install a
555 * reject route for such a case?
556 */
557 if (ip6_forward_rt.ro_rt &&
558 (ip6_forward_rt.ro_rt->rt_flags &
559 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
560 #ifdef RTF_WASCLONED
561 !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) &&
562 #endif
563 #ifdef RTF_CLONED
564 !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) &&
565 #endif
566 #if 0
567 /*
568 * The check below is redundant since the comparison of
569 * the destination and the key of the rtentry has
570 * already done through looking up the routing table.
571 */
572 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
573 &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr)
574 #endif
575 ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) {
576 struct in6_ifaddr *ia6 =
577 (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa;
578
579 /*
580 * record address information into m_tag.
581 */
582 (void)ip6_setdstifaddr(m, ia6);
583
584 /*
585 * packets to a tentative, duplicated, or somehow invalid
586 * address must not be accepted.
587 */
588 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
589 /* this address is ready */
590 ours = 1;
591 deliverifp = ia6->ia_ifp; /* correct? */
592 /* Count the packet in the ip address stats */
593 ia6->ia_ifa.if_ipackets++;
594 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
595 goto hbhcheck;
596 } else {
597 char ip6bufs[INET6_ADDRSTRLEN];
598 char ip6bufd[INET6_ADDRSTRLEN];
599 /* address is not ready, so discard the packet. */
600 nd6log((LOG_INFO,
601 "ip6_input: packet to an unready address %s->%s\n",
602 ip6_sprintf(ip6bufs, &ip6->ip6_src),
603 ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
604
605 goto bad;
606 }
607 }
608
609 /*
610 * FAITH (Firewall Aided Internet Translator)
611 */
612 if (ip6_keepfaith) {
613 if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp
614 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) {
615 /* XXX do we need more sanity checks? */
616 ours = 1;
617 deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */
618 goto hbhcheck;
619 }
620 }
621
622 /*
623 * Now there is no reason to process the packet if it's not our own
624 * and we're not a router.
625 */
626 if (!ip6_forwarding) {
627 ip6stat.ip6s_cantforward++;
628 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
629 goto bad;
630 }
631
632 hbhcheck:
633 /*
634 * record address information into m_tag, if we don't have one yet.
635 * note that we are unable to record it, if the address is not listed
636 * as our interface address (e.g. multicast addresses, addresses
637 * within FAITH prefixes and such).
638 */
639 if (deliverifp && !ip6_getdstifaddr(m)) {
640 struct in6_ifaddr *ia6;
641
642 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
643 if (ia6) {
644 if (!ip6_setdstifaddr(m, ia6)) {
645 /*
646 * XXX maybe we should drop the packet here,
647 * as we could not provide enough information
648 * to the upper layers.
649 */
650 }
651 }
652 }
653
654 /*
655 * Process Hop-by-Hop options header if it's contained.
656 * m may be modified in ip6_hopopts_input().
657 * If a JumboPayload option is included, plen will also be modified.
658 */
659 plen = (u_int32_t)ntohs(ip6->ip6_plen);
660 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
661 struct ip6_hbh *hbh;
662
663 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) {
664 #if 0 /*touches NULL pointer*/
665 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
666 #endif
667 return; /* m have already been freed */
668 }
669
670 /* adjust pointer */
671 ip6 = mtod(m, struct ip6_hdr *);
672
673 /*
674 * if the payload length field is 0 and the next header field
675 * indicates Hop-by-Hop Options header, then a Jumbo Payload
676 * option MUST be included.
677 */
678 if (ip6->ip6_plen == 0 && plen == 0) {
679 /*
680 * Note that if a valid jumbo payload option is
681 * contained, ip6_hopopts_input() must set a valid
682 * (non-zero) payload length to the variable plen.
683 */
684 ip6stat.ip6s_badoptions++;
685 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
686 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
687 icmp6_error(m, ICMP6_PARAM_PROB,
688 ICMP6_PARAMPROB_HEADER,
689 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
690 return;
691 }
692 #ifndef PULLDOWN_TEST
693 /* ip6_hopopts_input() ensures that mbuf is contiguous */
694 hbh = (struct ip6_hbh *)(ip6 + 1);
695 #else
696 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
697 sizeof(struct ip6_hbh));
698 if (hbh == NULL) {
699 ip6stat.ip6s_tooshort++;
700 return;
701 }
702 #endif
703 nxt = hbh->ip6h_nxt;
704
705 /*
706 * If we are acting as a router and the packet contains a
707 * router alert option, see if we know the option value.
708 * Currently, we only support the option value for MLD, in which
709 * case we should pass the packet to the multicast routing
710 * daemon.
711 */
712 if (rtalert != ~0 && ip6_forwarding) {
713 switch (rtalert) {
714 case IP6OPT_RTALERT_MLD:
715 ours = 1;
716 break;
717 default:
718 /*
719 * RFC2711 requires unrecognized values must be
720 * silently ignored.
721 */
722 break;
723 }
724 }
725 } else
726 nxt = ip6->ip6_nxt;
727
728 /*
729 * Check that the amount of data in the buffers
730 * is as at least much as the IPv6 header would have us expect.
731 * Trim mbufs if longer than we expect.
732 * Drop packet if shorter than we expect.
733 */
734 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
735 ip6stat.ip6s_tooshort++;
736 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
737 goto bad;
738 }
739 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
740 if (m->m_len == m->m_pkthdr.len) {
741 m->m_len = sizeof(struct ip6_hdr) + plen;
742 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
743 } else
744 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
745 }
746
747 /*
748 * Forward if desirable.
749 */
750 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
751 /*
752 * If we are acting as a multicast router, all
753 * incoming multicast packets are passed to the
754 * kernel-level multicast forwarding function.
755 * The packet is returned (relatively) intact; if
756 * ip6_mforward() returns a non-zero value, the packet
757 * must be discarded, else it may be accepted below.
758 */
759 if (ip6_mrouter && ip6_mforward &&
760 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
761 ip6stat.ip6s_cantforward++;
762 m_freem(m);
763 return;
764 }
765 if (!ours) {
766 m_freem(m);
767 return;
768 }
769 } else if (!ours) {
770 ip6_forward(m, srcrt);
771 return;
772 }
773
774 ip6 = mtod(m, struct ip6_hdr *);
775
776 /*
777 * Malicious party may be able to use IPv4 mapped addr to confuse
778 * tcp/udp stack and bypass security checks (act as if it was from
779 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious.
780 *
781 * For SIIT end node behavior, you may want to disable the check.
782 * However, you will become vulnerable to attacks using IPv4 mapped
783 * source.
784 */
785 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
786 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
787 ip6stat.ip6s_badscope++;
788 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
789 goto bad;
790 }
791
792 /*
793 * Tell launch routine the next header
794 */
795 ip6stat.ip6s_delivered++;
796 in6_ifstat_inc(deliverifp, ifs6_in_deliver);
797 nest = 0;
798
799 while (nxt != IPPROTO_DONE) {
800 if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
801 ip6stat.ip6s_toomanyhdr++;
802 goto bad;
803 }
804
805 /*
806 * protection against faulty packet - there should be
807 * more sanity checks in header chain processing.
808 */
809 if (m->m_pkthdr.len < off) {
810 ip6stat.ip6s_tooshort++;
811 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
812 goto bad;
813 }
814
815 #ifdef IPSEC
816 /*
817 * enforce IPsec policy checking if we are seeing last header.
818 * note that we do not visit this with protocols with pcb layer
819 * code - like udp/tcp/raw ip.
820 */
821 if (ip6_ipsec_input(m, nxt))
822 goto bad;
823 #endif /* IPSEC */
824 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
825 }
826 return;
827 bad:
828 m_freem(m);
829 }
830
831 /*
832 * set/grab in6_ifaddr correspond to IPv6 destination address.
833 * XXX backward compatibility wrapper
834 */
835 static struct ip6aux *
836 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6)
837 {
838 struct ip6aux *ip6a;
839
840 ip6a = ip6_addaux(m);
841 if (ip6a)
842 ip6a->ip6a_dstia6 = ia6;
843 return ip6a; /* NULL if failed to set */
844 }
845
846 struct in6_ifaddr *
847 ip6_getdstifaddr(struct mbuf *m)
848 {
849 struct ip6aux *ip6a;
850
851 ip6a = ip6_findaux(m);
852 if (ip6a)
853 return ip6a->ip6a_dstia6;
854 else
855 return NULL;
856 }
857
858 /*
859 * Hop-by-Hop options header processing. If a valid jumbo payload option is
860 * included, the real payload length will be stored in plenp.
861 *
862 * rtalertp - XXX: should be stored more smart way
863 */
864 static int
865 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp,
866 struct mbuf **mp, int *offp)
867 {
868 struct mbuf *m = *mp;
869 int off = *offp, hbhlen;
870 struct ip6_hbh *hbh;
871 u_int8_t *opt;
872
873 /* validation of the length of the header */
874 #ifndef PULLDOWN_TEST
875 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1);
876 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
877 hbhlen = (hbh->ip6h_len + 1) << 3;
878
879 IP6_EXTHDR_CHECK(m, off, hbhlen, -1);
880 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
881 #else
882 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
883 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
884 if (hbh == NULL) {
885 ip6stat.ip6s_tooshort++;
886 return -1;
887 }
888 hbhlen = (hbh->ip6h_len + 1) << 3;
889 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
890 hbhlen);
891 if (hbh == NULL) {
892 ip6stat.ip6s_tooshort++;
893 return -1;
894 }
895 #endif
896 off += hbhlen;
897 hbhlen -= sizeof(struct ip6_hbh);
898 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh);
899
900 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
901 hbhlen, rtalertp, plenp) < 0)
902 return (-1);
903
904 *offp = off;
905 *mp = m;
906 return (0);
907 }
908
909 /*
910 * Search header for all Hop-by-hop options and process each option.
911 * This function is separate from ip6_hopopts_input() in order to
912 * handle a case where the sending node itself process its hop-by-hop
913 * options header. In such a case, the function is called from ip6_output().
914 *
915 * The function assumes that hbh header is located right after the IPv6 header
916 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
917 * opthead + hbhlen is located in continuous memory region.
918 */
919 int
920 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen,
921 u_int32_t *rtalertp, u_int32_t *plenp)
922 {
923 struct ip6_hdr *ip6;
924 int optlen = 0;
925 u_int8_t *opt = opthead;
926 u_int16_t rtalert_val;
927 u_int32_t jumboplen;
928 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
929
930 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
931 switch (*opt) {
932 case IP6OPT_PAD1:
933 optlen = 1;
934 break;
935 case IP6OPT_PADN:
936 if (hbhlen < IP6OPT_MINLEN) {
937 ip6stat.ip6s_toosmall++;
938 goto bad;
939 }
940 optlen = *(opt + 1) + 2;
941 break;
942 case IP6OPT_ROUTER_ALERT:
943 /* XXX may need check for alignment */
944 if (hbhlen < IP6OPT_RTALERT_LEN) {
945 ip6stat.ip6s_toosmall++;
946 goto bad;
947 }
948 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
949 /* XXX stat */
950 icmp6_error(m, ICMP6_PARAM_PROB,
951 ICMP6_PARAMPROB_HEADER,
952 erroff + opt + 1 - opthead);
953 return (-1);
954 }
955 optlen = IP6OPT_RTALERT_LEN;
956 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
957 *rtalertp = ntohs(rtalert_val);
958 break;
959 case IP6OPT_JUMBO:
960 /* XXX may need check for alignment */
961 if (hbhlen < IP6OPT_JUMBO_LEN) {
962 ip6stat.ip6s_toosmall++;
963 goto bad;
964 }
965 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
966 /* XXX stat */
967 icmp6_error(m, ICMP6_PARAM_PROB,
968 ICMP6_PARAMPROB_HEADER,
969 erroff + opt + 1 - opthead);
970 return (-1);
971 }
972 optlen = IP6OPT_JUMBO_LEN;
973
974 /*
975 * IPv6 packets that have non 0 payload length
976 * must not contain a jumbo payload option.
977 */
978 ip6 = mtod(m, struct ip6_hdr *);
979 if (ip6->ip6_plen) {
980 ip6stat.ip6s_badoptions++;
981 icmp6_error(m, ICMP6_PARAM_PROB,
982 ICMP6_PARAMPROB_HEADER,
983 erroff + opt - opthead);
984 return (-1);
985 }
986
987 /*
988 * We may see jumbolen in unaligned location, so
989 * we'd need to perform bcopy().
990 */
991 bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
992 jumboplen = (u_int32_t)htonl(jumboplen);
993
994 #if 1
995 /*
996 * if there are multiple jumbo payload options,
997 * *plenp will be non-zero and the packet will be
998 * rejected.
999 * the behavior may need some debate in ipngwg -
1000 * multiple options does not make sense, however,
1001 * there's no explicit mention in specification.
1002 */
1003 if (*plenp != 0) {
1004 ip6stat.ip6s_badoptions++;
1005 icmp6_error(m, ICMP6_PARAM_PROB,
1006 ICMP6_PARAMPROB_HEADER,
1007 erroff + opt + 2 - opthead);
1008 return (-1);
1009 }
1010 #endif
1011
1012 /*
1013 * jumbo payload length must be larger than 65535.
1014 */
1015 if (jumboplen <= IPV6_MAXPACKET) {
1016 ip6stat.ip6s_badoptions++;
1017 icmp6_error(m, ICMP6_PARAM_PROB,
1018 ICMP6_PARAMPROB_HEADER,
1019 erroff + opt + 2 - opthead);
1020 return (-1);
1021 }
1022 *plenp = jumboplen;
1023
1024 break;
1025 default: /* unknown option */
1026 if (hbhlen < IP6OPT_MINLEN) {
1027 ip6stat.ip6s_toosmall++;
1028 goto bad;
1029 }
1030 optlen = ip6_unknown_opt(opt, m,
1031 erroff + opt - opthead);
1032 if (optlen == -1)
1033 return (-1);
1034 optlen += 2;
1035 break;
1036 }
1037 }
1038
1039 return (0);
1040
1041 bad:
1042 m_freem(m);
1043 return (-1);
1044 }
1045
1046 /*
1047 * Unknown option processing.
1048 * The third argument `off' is the offset from the IPv6 header to the option,
1049 * which is necessary if the IPv6 header the and option header and IPv6 header
1050 * is not continuous in order to return an ICMPv6 error.
1051 */
1052 int
1053 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off)
1054 {
1055 struct ip6_hdr *ip6;
1056
1057 switch (IP6OPT_TYPE(*optp)) {
1058 case IP6OPT_TYPE_SKIP: /* ignore the option */
1059 return ((int)*(optp + 1));
1060 case IP6OPT_TYPE_DISCARD: /* silently discard */
1061 m_freem(m);
1062 return (-1);
1063 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
1064 ip6stat.ip6s_badoptions++;
1065 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
1066 return (-1);
1067 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
1068 ip6stat.ip6s_badoptions++;
1069 ip6 = mtod(m, struct ip6_hdr *);
1070 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
1071 (m->m_flags & (M_BCAST|M_MCAST)))
1072 m_freem(m);
1073 else
1074 icmp6_error(m, ICMP6_PARAM_PROB,
1075 ICMP6_PARAMPROB_OPTION, off);
1076 return (-1);
1077 }
1078
1079 m_freem(m); /* XXX: NOTREACHED */
1080 return (-1);
1081 }
1082
1083 /*
1084 * Create the "control" list for this pcb.
1085 * These functions will not modify mbuf chain at all.
1086 *
1087 * With KAME mbuf chain restriction:
1088 * The routine will be called from upper layer handlers like tcp6_input().
1089 * Thus the routine assumes that the caller (tcp6_input) have already
1090 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the
1091 * very first mbuf on the mbuf chain.
1092 *
1093 * ip6_savecontrol_v4 will handle those options that are possible to be
1094 * set on a v4-mapped socket.
1095 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those
1096 * options and handle the v6-only ones itself.
1097 */
1098 struct mbuf **
1099 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp,
1100 int *v4only)
1101 {
1102 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1103
1104 #ifdef SO_TIMESTAMP
1105 if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) {
1106 struct timeval tv;
1107
1108 microtime(&tv);
1109 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1110 SCM_TIMESTAMP, SOL_SOCKET);
1111 if (*mp)
1112 mp = &(*mp)->m_next;
1113 }
1114 #endif
1115
1116 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1117 if (v4only != NULL)
1118 *v4only = 1;
1119 return (mp);
1120 }
1121
1122 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y))
1123 /* RFC 2292 sec. 5 */
1124 if ((inp->inp_flags & IN6P_PKTINFO) != 0) {
1125 struct in6_pktinfo pi6;
1126
1127 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
1128 in6_clearscope(&pi6.ipi6_addr); /* XXX */
1129 pi6.ipi6_ifindex =
1130 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0;
1131
1132 *mp = sbcreatecontrol((caddr_t) &pi6,
1133 sizeof(struct in6_pktinfo),
1134 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6);
1135 if (*mp)
1136 mp = &(*mp)->m_next;
1137 }
1138
1139 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) {
1140 int hlim = ip6->ip6_hlim & 0xff;
1141
1142 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int),
1143 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT),
1144 IPPROTO_IPV6);
1145 if (*mp)
1146 mp = &(*mp)->m_next;
1147 }
1148
1149 if (v4only != NULL)
1150 *v4only = 0;
1151 return (mp);
1152 }
1153
1154 void
1155 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp)
1156 {
1157 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1158 int v4only = 0;
1159
1160 mp = ip6_savecontrol_v4(in6p, m, mp, &v4only);
1161 if (v4only)
1162 return;
1163
1164 if ((in6p->inp_flags & IN6P_TCLASS) != 0) {
1165 u_int32_t flowinfo;
1166 int tclass;
1167
1168 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
1169 flowinfo >>= 20;
1170
1171 tclass = flowinfo & 0xff;
1172 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass),
1173 IPV6_TCLASS, IPPROTO_IPV6);
1174 if (*mp)
1175 mp = &(*mp)->m_next;
1176 }
1177
1178 /*
1179 * IPV6_HOPOPTS socket option. Recall that we required super-user
1180 * privilege for the option (see ip6_ctloutput), but it might be too
1181 * strict, since there might be some hop-by-hop options which can be
1182 * returned to normal user.
1183 * See also RFC 2292 section 6 (or RFC 3542 section 8).
1184 */
1185 if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) {
1186 /*
1187 * Check if a hop-by-hop options header is contatined in the
1188 * received packet, and if so, store the options as ancillary
1189 * data. Note that a hop-by-hop options header must be
1190 * just after the IPv6 header, which is assured through the
1191 * IPv6 input processing.
1192 */
1193 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
1194 struct ip6_hbh *hbh;
1195 int hbhlen = 0;
1196 #ifdef PULLDOWN_TEST
1197 struct mbuf *ext;
1198 #endif
1199
1200 #ifndef PULLDOWN_TEST
1201 hbh = (struct ip6_hbh *)(ip6 + 1);
1202 hbhlen = (hbh->ip6h_len + 1) << 3;
1203 #else
1204 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
1205 ip6->ip6_nxt);
1206 if (ext == NULL) {
1207 ip6stat.ip6s_tooshort++;
1208 return;
1209 }
1210 hbh = mtod(ext, struct ip6_hbh *);
1211 hbhlen = (hbh->ip6h_len + 1) << 3;
1212 if (hbhlen != ext->m_len) {
1213 m_freem(ext);
1214 ip6stat.ip6s_tooshort++;
1215 return;
1216 }
1217 #endif
1218
1219 /*
1220 * XXX: We copy the whole header even if a
1221 * jumbo payload option is included, the option which
1222 * is to be removed before returning according to
1223 * RFC2292.
1224 * Note: this constraint is removed in RFC3542
1225 */
1226 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
1227 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS),
1228 IPPROTO_IPV6);
1229 if (*mp)
1230 mp = &(*mp)->m_next;
1231 #ifdef PULLDOWN_TEST
1232 m_freem(ext);
1233 #endif
1234 }
1235 }
1236
1237 if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) {
1238 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
1239
1240 /*
1241 * Search for destination options headers or routing
1242 * header(s) through the header chain, and stores each
1243 * header as ancillary data.
1244 * Note that the order of the headers remains in
1245 * the chain of ancillary data.
1246 */
1247 while (1) { /* is explicit loop prevention necessary? */
1248 struct ip6_ext *ip6e = NULL;
1249 int elen;
1250 #ifdef PULLDOWN_TEST
1251 struct mbuf *ext = NULL;
1252 #endif
1253
1254 /*
1255 * if it is not an extension header, don't try to
1256 * pull it from the chain.
1257 */
1258 switch (nxt) {
1259 case IPPROTO_DSTOPTS:
1260 case IPPROTO_ROUTING:
1261 case IPPROTO_HOPOPTS:
1262 case IPPROTO_AH: /* is it possible? */
1263 break;
1264 default:
1265 goto loopend;
1266 }
1267
1268 #ifndef PULLDOWN_TEST
1269 if (off + sizeof(*ip6e) > m->m_len)
1270 goto loopend;
1271 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
1272 if (nxt == IPPROTO_AH)
1273 elen = (ip6e->ip6e_len + 2) << 2;
1274 else
1275 elen = (ip6e->ip6e_len + 1) << 3;
1276 if (off + elen > m->m_len)
1277 goto loopend;
1278 #else
1279 ext = ip6_pullexthdr(m, off, nxt);
1280 if (ext == NULL) {
1281 ip6stat.ip6s_tooshort++;
1282 return;
1283 }
1284 ip6e = mtod(ext, struct ip6_ext *);
1285 if (nxt == IPPROTO_AH)
1286 elen = (ip6e->ip6e_len + 2) << 2;
1287 else
1288 elen = (ip6e->ip6e_len + 1) << 3;
1289 if (elen != ext->m_len) {
1290 m_freem(ext);
1291 ip6stat.ip6s_tooshort++;
1292 return;
1293 }
1294 #endif
1295
1296 switch (nxt) {
1297 case IPPROTO_DSTOPTS:
1298 if (!(in6p->inp_flags & IN6P_DSTOPTS))
1299 break;
1300
1301 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1302 IS2292(in6p,
1303 IPV6_2292DSTOPTS, IPV6_DSTOPTS),
1304 IPPROTO_IPV6);
1305 if (*mp)
1306 mp = &(*mp)->m_next;
1307 break;
1308 case IPPROTO_ROUTING:
1309 if (!in6p->inp_flags & IN6P_RTHDR)
1310 break;
1311
1312 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1313 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR),
1314 IPPROTO_IPV6);
1315 if (*mp)
1316 mp = &(*mp)->m_next;
1317 break;
1318 case IPPROTO_HOPOPTS:
1319 case IPPROTO_AH: /* is it possible? */
1320 break;
1321
1322 default:
1323 /*
1324 * other cases have been filtered in the above.
1325 * none will visit this case. here we supply
1326 * the code just in case (nxt overwritten or
1327 * other cases).
1328 */
1329 #ifdef PULLDOWN_TEST
1330 m_freem(ext);
1331 #endif
1332 goto loopend;
1333
1334 }
1335
1336 /* proceed with the next header. */
1337 off += elen;
1338 nxt = ip6e->ip6e_nxt;
1339 ip6e = NULL;
1340 #ifdef PULLDOWN_TEST
1341 m_freem(ext);
1342 ext = NULL;
1343 #endif
1344 }
1345 loopend:
1346 ;
1347 }
1348 }
1349 #undef IS2292
1350
1351 void
1352 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu)
1353 {
1354 struct socket *so;
1355 struct mbuf *m_mtu;
1356 struct ip6_mtuinfo mtuctl;
1357
1358 so = in6p->inp_socket;
1359
1360 if (mtu == NULL)
1361 return;
1362
1363 #ifdef DIAGNOSTIC
1364 if (so == NULL) /* I believe this is impossible */
1365 panic("ip6_notify_pmtu: socket is NULL");
1366 #endif
1367
1368 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */
1369 mtuctl.ip6m_mtu = *mtu;
1370 mtuctl.ip6m_addr = *dst;
1371 if (sa6_recoverscope(&mtuctl.ip6m_addr))
1372 return;
1373
1374 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl),
1375 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL)
1376 return;
1377
1378 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu)
1379 == 0) {
1380 m_freem(m_mtu);
1381 /* XXX: should count statistics */
1382 } else
1383 sorwakeup(so);
1384
1385 return;
1386 }
1387
1388 #ifdef PULLDOWN_TEST
1389 /*
1390 * pull single extension header from mbuf chain. returns single mbuf that
1391 * contains the result, or NULL on error.
1392 */
1393 static struct mbuf *
1394 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt)
1395 {
1396 struct ip6_ext ip6e;
1397 size_t elen;
1398 struct mbuf *n;
1399
1400 #ifdef DIAGNOSTIC
1401 switch (nxt) {
1402 case IPPROTO_DSTOPTS:
1403 case IPPROTO_ROUTING:
1404 case IPPROTO_HOPOPTS:
1405 case IPPROTO_AH: /* is it possible? */
1406 break;
1407 default:
1408 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
1409 }
1410 #endif
1411
1412 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1413 if (nxt == IPPROTO_AH)
1414 elen = (ip6e.ip6e_len + 2) << 2;
1415 else
1416 elen = (ip6e.ip6e_len + 1) << 3;
1417
1418 MGET(n, M_DONTWAIT, MT_DATA);
1419 if (n && elen >= MLEN) {
1420 MCLGET(n, M_DONTWAIT);
1421 if ((n->m_flags & M_EXT) == 0) {
1422 m_free(n);
1423 n = NULL;
1424 }
1425 }
1426 if (!n)
1427 return NULL;
1428
1429 n->m_len = 0;
1430 if (elen >= M_TRAILINGSPACE(n)) {
1431 m_free(n);
1432 return NULL;
1433 }
1434
1435 m_copydata(m, off, elen, mtod(n, caddr_t));
1436 n->m_len = elen;
1437 return n;
1438 }
1439 #endif
1440
1441 /*
1442 * Get pointer to the previous header followed by the header
1443 * currently processed.
1444 * XXX: This function supposes that
1445 * M includes all headers,
1446 * the next header field and the header length field of each header
1447 * are valid, and
1448 * the sum of each header length equals to OFF.
1449 * Because of these assumptions, this function must be called very
1450 * carefully. Moreover, it will not be used in the near future when
1451 * we develop `neater' mechanism to process extension headers.
1452 */
1453 char *
1454 ip6_get_prevhdr(struct mbuf *m, int off)
1455 {
1456 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1457
1458 if (off == sizeof(struct ip6_hdr))
1459 return (&ip6->ip6_nxt);
1460 else {
1461 int len, nxt;
1462 struct ip6_ext *ip6e = NULL;
1463
1464 nxt = ip6->ip6_nxt;
1465 len = sizeof(struct ip6_hdr);
1466 while (len < off) {
1467 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);
1468
1469 switch (nxt) {
1470 case IPPROTO_FRAGMENT:
1471 len += sizeof(struct ip6_frag);
1472 break;
1473 case IPPROTO_AH:
1474 len += (ip6e->ip6e_len + 2) << 2;
1475 break;
1476 default:
1477 len += (ip6e->ip6e_len + 1) << 3;
1478 break;
1479 }
1480 nxt = ip6e->ip6e_nxt;
1481 }
1482 if (ip6e)
1483 return (&ip6e->ip6e_nxt);
1484 else
1485 return NULL;
1486 }
1487 }
1488
1489 /*
1490 * get next header offset. m will be retained.
1491 */
1492 int
1493 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp)
1494 {
1495 struct ip6_hdr ip6;
1496 struct ip6_ext ip6e;
1497 struct ip6_frag fh;
1498
1499 /* just in case */
1500 if (m == NULL)
1501 panic("ip6_nexthdr: m == NULL");
1502 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
1503 return -1;
1504
1505 switch (proto) {
1506 case IPPROTO_IPV6:
1507 if (m->m_pkthdr.len < off + sizeof(ip6))
1508 return -1;
1509 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
1510 if (nxtp)
1511 *nxtp = ip6.ip6_nxt;
1512 off += sizeof(ip6);
1513 return off;
1514
1515 case IPPROTO_FRAGMENT:
1516 /*
1517 * terminate parsing if it is not the first fragment,
1518 * it does not make sense to parse through it.
1519 */
1520 if (m->m_pkthdr.len < off + sizeof(fh))
1521 return -1;
1522 m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
1523 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */
1524 if (fh.ip6f_offlg & IP6F_OFF_MASK)
1525 return -1;
1526 if (nxtp)
1527 *nxtp = fh.ip6f_nxt;
1528 off += sizeof(struct ip6_frag);
1529 return off;
1530
1531 case IPPROTO_AH:
1532 if (m->m_pkthdr.len < off + sizeof(ip6e))
1533 return -1;
1534 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1535 if (nxtp)
1536 *nxtp = ip6e.ip6e_nxt;
1537 off += (ip6e.ip6e_len + 2) << 2;
1538 return off;
1539
1540 case IPPROTO_HOPOPTS:
1541 case IPPROTO_ROUTING:
1542 case IPPROTO_DSTOPTS:
1543 if (m->m_pkthdr.len < off + sizeof(ip6e))
1544 return -1;
1545 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1546 if (nxtp)
1547 *nxtp = ip6e.ip6e_nxt;
1548 off += (ip6e.ip6e_len + 1) << 3;
1549 return off;
1550
1551 case IPPROTO_NONE:
1552 case IPPROTO_ESP:
1553 case IPPROTO_IPCOMP:
1554 /* give up */
1555 return -1;
1556
1557 default:
1558 return -1;
1559 }
1560
1561 return -1;
1562 }
1563
1564 /*
1565 * get offset for the last header in the chain. m will be kept untainted.
1566 */
1567 int
1568 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp)
1569 {
1570 int newoff;
1571 int nxt;
1572
1573 if (!nxtp) {
1574 nxt = -1;
1575 nxtp = &nxt;
1576 }
1577 while (1) {
1578 newoff = ip6_nexthdr(m, off, proto, nxtp);
1579 if (newoff < 0)
1580 return off;
1581 else if (newoff < off)
1582 return -1; /* invalid */
1583 else if (newoff == off)
1584 return newoff;
1585
1586 off = newoff;
1587 proto = *nxtp;
1588 }
1589 }
1590
1591 struct ip6aux *
1592 ip6_addaux(struct mbuf *m)
1593 {
1594 struct m_tag *mtag;
1595
1596 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1597 if (!mtag) {
1598 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux),
1599 M_NOWAIT);
1600 if (mtag) {
1601 m_tag_prepend(m, mtag);
1602 bzero(mtag + 1, sizeof(struct ip6aux));
1603 }
1604 }
1605 return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1606 }
1607
1608 struct ip6aux *
1609 ip6_findaux(struct mbuf *m)
1610 {
1611 struct m_tag *mtag;
1612
1613 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1614 return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1615 }
1616
1617 void
1618 ip6_delaux(struct mbuf *m)
1619 {
1620 struct m_tag *mtag;
1621
1622 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1623 if (mtag)
1624 m_tag_delete(m, mtag);
1625 }
1626
1627 /*
1628 * System control for IP6
1629 */
1630
1631 u_char inet6ctlerrmap[PRC_NCMDS] = {
1632 0, 0, 0, 0,
1633 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1634 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1635 EMSGSIZE, EHOSTUNREACH, 0, 0,
1636 0, 0, 0, 0,
1637 ENOPROTOOPT
1638 };
Cache object: 139c1b672dcde956e087b3a18ac9c5b8
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