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/8.2/sys/netinet6/ip6_input.c 236953 2012-06-12 12:10:10Z bz $");
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 #include <net/vnet.h>
91
92 #include <netinet/in.h>
93 #include <netinet/in_systm.h>
94 #include <net/if_llatbl.h>
95 #ifdef INET
96 #include <netinet/ip.h>
97 #include <netinet/ip_icmp.h>
98 #endif /* INET */
99 #include <netinet/ip6.h>
100 #include <netinet6/in6_var.h>
101 #include <netinet6/ip6_var.h>
102 #include <netinet/in_pcb.h>
103 #include <netinet/icmp6.h>
104 #include <netinet6/scope6_var.h>
105 #include <netinet6/in6_ifattach.h>
106 #include <netinet6/nd6.h>
107
108 #ifdef IPSEC
109 #include <netipsec/ipsec.h>
110 #include <netinet6/ip6_ipsec.h>
111 #include <netipsec/ipsec6.h>
112 #endif /* IPSEC */
113
114 #include <netinet6/ip6protosw.h>
115
116 extern struct domain inet6domain;
117
118 u_char ip6_protox[IPPROTO_MAX];
119 VNET_DEFINE(struct in6_ifaddrhead, in6_ifaddrhead);
120
121 static struct netisr_handler ip6_nh = {
122 .nh_name = "ip6",
123 .nh_handler = ip6_input,
124 .nh_proto = NETISR_IPV6,
125 .nh_policy = NETISR_POLICY_FLOW,
126 };
127
128 VNET_DECLARE(struct callout, in6_tmpaddrtimer_ch);
129 #define V_in6_tmpaddrtimer_ch VNET(in6_tmpaddrtimer_ch)
130
131 VNET_DEFINE(struct pfil_head, inet6_pfil_hook);
132
133 VNET_DEFINE(struct ip6stat, ip6stat);
134
135 struct rwlock in6_ifaddr_lock;
136 RW_SYSINIT(in6_ifaddr_lock, &in6_ifaddr_lock, "in6_ifaddr_lock");
137
138 static void ip6_init2(void *);
139 static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *);
140 static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *);
141 #ifdef PULLDOWN_TEST
142 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int);
143 #endif
144
145 /*
146 * IP6 initialization: fill in IP6 protocol switch table.
147 * All protocols not implemented in kernel go to raw IP6 protocol handler.
148 */
149 void
150 ip6_init(void)
151 {
152 struct ip6protosw *pr;
153 int i;
154
155 TUNABLE_INT_FETCH("net.inet6.ip6.auto_linklocal",
156 &V_ip6_auto_linklocal);
157
158 TAILQ_INIT(&V_in6_ifaddrhead);
159
160 /* Initialize packet filter hooks. */
161 V_inet6_pfil_hook.ph_type = PFIL_TYPE_AF;
162 V_inet6_pfil_hook.ph_af = AF_INET6;
163 if ((i = pfil_head_register(&V_inet6_pfil_hook)) != 0)
164 printf("%s: WARNING: unable to register pfil hook, "
165 "error %d\n", __func__, i);
166
167 scope6_init();
168 addrsel_policy_init();
169 nd6_init();
170 frag6_init();
171
172 V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR;
173
174 /* Skip global initialization stuff for non-default instances. */
175 if (!IS_DEFAULT_VNET(curvnet))
176 return;
177
178 #ifdef DIAGNOSTIC
179 if (sizeof(struct protosw) != sizeof(struct ip6protosw))
180 panic("sizeof(protosw) != sizeof(ip6protosw)");
181 #endif
182 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
183 if (pr == NULL)
184 panic("ip6_init");
185
186 /* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */
187 for (i = 0; i < IPPROTO_MAX; i++)
188 ip6_protox[i] = pr - inet6sw;
189 /*
190 * Cycle through IP protocols and put them into the appropriate place
191 * in ip6_protox[].
192 */
193 for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
194 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++)
195 if (pr->pr_domain->dom_family == PF_INET6 &&
196 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
197 /* Be careful to only index valid IP protocols. */
198 if (pr->pr_protocol < IPPROTO_MAX)
199 ip6_protox[pr->pr_protocol] = pr - inet6sw;
200 }
201
202 netisr_register(&ip6_nh);
203 }
204
205 /*
206 * The protocol to be inserted into ip6_protox[] must be already registered
207 * in inet6sw[], either statically or through pf_proto_register().
208 */
209 int
210 ip6proto_register(short ip6proto)
211 {
212 struct ip6protosw *pr;
213
214 /* Sanity checks. */
215 if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX)
216 return (EPROTONOSUPPORT);
217
218 /*
219 * The protocol slot must not be occupied by another protocol
220 * already. An index pointing to IPPROTO_RAW is unused.
221 */
222 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
223 if (pr == NULL)
224 return (EPFNOSUPPORT);
225 if (ip6_protox[ip6proto] != pr - inet6sw) /* IPPROTO_RAW */
226 return (EEXIST);
227
228 /*
229 * Find the protocol position in inet6sw[] and set the index.
230 */
231 for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
232 pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) {
233 if (pr->pr_domain->dom_family == PF_INET6 &&
234 pr->pr_protocol && pr->pr_protocol == ip6proto) {
235 ip6_protox[pr->pr_protocol] = pr - inet6sw;
236 return (0);
237 }
238 }
239 return (EPROTONOSUPPORT);
240 }
241
242 int
243 ip6proto_unregister(short ip6proto)
244 {
245 struct ip6protosw *pr;
246
247 /* Sanity checks. */
248 if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX)
249 return (EPROTONOSUPPORT);
250
251 /* Check if the protocol was indeed registered. */
252 pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
253 if (pr == NULL)
254 return (EPFNOSUPPORT);
255 if (ip6_protox[ip6proto] == pr - inet6sw) /* IPPROTO_RAW */
256 return (ENOENT);
257
258 /* Reset the protocol slot to IPPROTO_RAW. */
259 ip6_protox[ip6proto] = pr - inet6sw;
260 return (0);
261 }
262
263 #ifdef VIMAGE
264 void
265 ip6_destroy()
266 {
267
268 nd6_destroy();
269 callout_drain(&V_in6_tmpaddrtimer_ch);
270 }
271 #endif
272
273 static int
274 ip6_init2_vnet(const void *unused __unused)
275 {
276
277 /* nd6_timer_init */
278 callout_init(&V_nd6_timer_ch, 0);
279 callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet);
280
281 /* timer for regeneranation of temporary addresses randomize ID */
282 callout_init(&V_in6_tmpaddrtimer_ch, 0);
283 callout_reset(&V_in6_tmpaddrtimer_ch,
284 (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
285 V_ip6_temp_regen_advance) * hz,
286 in6_tmpaddrtimer, curvnet);
287
288 return (0);
289 }
290
291 static void
292 ip6_init2(void *dummy)
293 {
294
295 ip6_init2_vnet(NULL);
296 }
297
298 /* cheat */
299 /* This must be after route_init(), which is now SI_ORDER_THIRD */
300 SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL);
301
302 void
303 ip6_input(struct mbuf *m)
304 {
305 struct ip6_hdr *ip6;
306 int off = sizeof(struct ip6_hdr), nest;
307 u_int32_t plen;
308 u_int32_t rtalert = ~0;
309 int nxt, ours = 0;
310 struct ifnet *deliverifp = NULL, *ifp = NULL;
311 struct in6_addr odst;
312 struct route_in6 rin6;
313 int srcrt = 0;
314 struct llentry *lle = NULL;
315 struct sockaddr_in6 dst6, *dst;
316
317 bzero(&rin6, sizeof(struct route_in6));
318 #ifdef IPSEC
319 /*
320 * should the inner packet be considered authentic?
321 * see comment in ah4_input().
322 * NB: m cannot be NULL when passed to the input routine
323 */
324
325 m->m_flags &= ~M_AUTHIPHDR;
326 m->m_flags &= ~M_AUTHIPDGM;
327
328 #endif /* IPSEC */
329
330 /*
331 * make sure we don't have onion peering information into m_tag.
332 */
333 ip6_delaux(m);
334
335 /*
336 * mbuf statistics
337 */
338 if (m->m_flags & M_EXT) {
339 if (m->m_next)
340 V_ip6stat.ip6s_mext2m++;
341 else
342 V_ip6stat.ip6s_mext1++;
343 } else {
344 #define M2MMAX (sizeof(V_ip6stat.ip6s_m2m)/sizeof(V_ip6stat.ip6s_m2m[0]))
345 if (m->m_next) {
346 if (m->m_flags & M_LOOP) {
347 V_ip6stat.ip6s_m2m[V_loif->if_index]++;
348 } else if (m->m_pkthdr.rcvif->if_index < M2MMAX)
349 V_ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++;
350 else
351 V_ip6stat.ip6s_m2m[0]++;
352 } else
353 V_ip6stat.ip6s_m1++;
354 #undef M2MMAX
355 }
356
357 /* drop the packet if IPv6 operation is disabled on the IF */
358 if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) {
359 m_freem(m);
360 return;
361 }
362
363 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
364 V_ip6stat.ip6s_total++;
365
366 #ifndef PULLDOWN_TEST
367 /*
368 * L2 bridge code and some other code can return mbuf chain
369 * that does not conform to KAME requirement. too bad.
370 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram?
371 */
372 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) {
373 struct mbuf *n;
374
375 MGETHDR(n, M_DONTWAIT, MT_HEADER);
376 if (n)
377 M_MOVE_PKTHDR(n, m);
378 if (n && n->m_pkthdr.len > MHLEN) {
379 MCLGET(n, M_DONTWAIT);
380 if ((n->m_flags & M_EXT) == 0) {
381 m_freem(n);
382 n = NULL;
383 }
384 }
385 if (n == NULL) {
386 m_freem(m);
387 return; /* ENOBUFS */
388 }
389
390 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
391 n->m_len = n->m_pkthdr.len;
392 m_freem(m);
393 m = n;
394 }
395 IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */);
396 #endif
397
398 if (m->m_len < sizeof(struct ip6_hdr)) {
399 struct ifnet *inifp;
400 inifp = m->m_pkthdr.rcvif;
401 if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
402 V_ip6stat.ip6s_toosmall++;
403 in6_ifstat_inc(inifp, ifs6_in_hdrerr);
404 return;
405 }
406 }
407
408 ip6 = mtod(m, struct ip6_hdr *);
409
410 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
411 V_ip6stat.ip6s_badvers++;
412 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
413 goto bad;
414 }
415
416 V_ip6stat.ip6s_nxthist[ip6->ip6_nxt]++;
417
418 /*
419 * Check against address spoofing/corruption.
420 */
421 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
422 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
423 /*
424 * XXX: "badscope" is not very suitable for a multicast source.
425 */
426 V_ip6stat.ip6s_badscope++;
427 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
428 goto bad;
429 }
430 if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) &&
431 !(m->m_flags & M_LOOP)) {
432 /*
433 * In this case, the packet should come from the loopback
434 * interface. However, we cannot just check the if_flags,
435 * because ip6_mloopback() passes the "actual" interface
436 * as the outgoing/incoming interface.
437 */
438 V_ip6stat.ip6s_badscope++;
439 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
440 goto bad;
441 }
442
443 #ifdef ALTQ
444 if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) {
445 /* packet is dropped by traffic conditioner */
446 return;
447 }
448 #endif
449 /*
450 * The following check is not documented in specs. A malicious
451 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
452 * and bypass security checks (act as if it was from 127.0.0.1 by using
453 * IPv6 src ::ffff:127.0.0.1). Be cautious.
454 *
455 * This check chokes if we are in an SIIT cloud. As none of BSDs
456 * support IPv4-less kernel compilation, we cannot support SIIT
457 * environment at all. So, it makes more sense for us to reject any
458 * malicious packets for non-SIIT environment, than try to do a
459 * partial support for SIIT environment.
460 */
461 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
462 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
463 V_ip6stat.ip6s_badscope++;
464 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
465 goto bad;
466 }
467 #if 0
468 /*
469 * Reject packets with IPv4 compatible addresses (auto tunnel).
470 *
471 * The code forbids auto tunnel relay case in RFC1933 (the check is
472 * stronger than RFC1933). We may want to re-enable it if mech-xx
473 * is revised to forbid relaying case.
474 */
475 if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
476 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
477 V_ip6stat.ip6s_badscope++;
478 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
479 goto bad;
480 }
481 #endif
482
483 /*
484 * Run through list of hooks for input packets.
485 *
486 * NB: Beware of the destination address changing
487 * (e.g. by NAT rewriting). When this happens,
488 * tell ip6_forward to do the right thing.
489 */
490 odst = ip6->ip6_dst;
491
492 /* Jump over all PFIL processing if hooks are not active. */
493 if (!PFIL_HOOKED(&V_inet6_pfil_hook))
494 goto passin;
495
496 if (pfil_run_hooks(&V_inet6_pfil_hook, &m,
497 m->m_pkthdr.rcvif, PFIL_IN, NULL))
498 return;
499 if (m == NULL) /* consumed by filter */
500 return;
501 ip6 = mtod(m, struct ip6_hdr *);
502 srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
503
504 passin:
505 /*
506 * Disambiguate address scope zones (if there is ambiguity).
507 * We first make sure that the original source or destination address
508 * is not in our internal form for scoped addresses. Such addresses
509 * are not necessarily invalid spec-wise, but we cannot accept them due
510 * to the usage conflict.
511 * in6_setscope() then also checks and rejects the cases where src or
512 * dst are the loopback address and the receiving interface
513 * is not loopback.
514 */
515 if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) {
516 V_ip6stat.ip6s_badscope++; /* XXX */
517 goto bad;
518 }
519 if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) ||
520 in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) {
521 V_ip6stat.ip6s_badscope++;
522 goto bad;
523 }
524
525 /*
526 * Multicast check. Assume packet is for us to avoid
527 * prematurely taking locks.
528 */
529 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
530 ours = 1;
531 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
532 deliverifp = m->m_pkthdr.rcvif;
533 goto hbhcheck;
534 }
535
536 /*
537 * Unicast check
538 */
539
540 bzero(&dst6, sizeof(dst6));
541 dst6.sin6_family = AF_INET6;
542 dst6.sin6_len = sizeof(struct sockaddr_in6);
543 dst6.sin6_addr = ip6->ip6_dst;
544 ifp = m->m_pkthdr.rcvif;
545 IF_AFDATA_LOCK(ifp);
546 lle = lla_lookup(LLTABLE6(ifp), 0,
547 (struct sockaddr *)&dst6);
548 IF_AFDATA_UNLOCK(ifp);
549 if ((lle != NULL) && (lle->la_flags & LLE_IFADDR)) {
550 struct ifaddr *ifa;
551 struct in6_ifaddr *ia6;
552 int bad;
553
554 bad = 1;
555 #define sa_equal(a1, a2) \
556 (bcmp((a1), (a2), ((a1))->sin6_len) == 0)
557 IF_ADDR_LOCK(ifp);
558 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
559 if (ifa->ifa_addr->sa_family != dst6.sin6_family)
560 continue;
561 if (sa_equal(&dst6, ifa->ifa_addr))
562 break;
563 }
564 KASSERT(ifa != NULL, ("%s: ifa not found for lle %p",
565 __func__, lle));
566 #undef sa_equal
567
568 ia6 = (struct in6_ifaddr *)ifa;
569 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
570 /* Count the packet in the ip address stats */
571 ia6->ia_ifa.if_ipackets++;
572 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
573
574 /*
575 * record address information into m_tag.
576 */
577 (void)ip6_setdstifaddr(m, ia6);
578
579 bad = 0;
580 } else {
581 char ip6bufs[INET6_ADDRSTRLEN];
582 char ip6bufd[INET6_ADDRSTRLEN];
583 /* address is not ready, so discard the packet. */
584 nd6log((LOG_INFO,
585 "ip6_input: packet to an unready address %s->%s\n",
586 ip6_sprintf(ip6bufs, &ip6->ip6_src),
587 ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
588 }
589 IF_ADDR_UNLOCK(ifp);
590 LLE_RUNLOCK(lle);
591 if (bad)
592 goto bad;
593 else {
594 ours = 1;
595 deliverifp = ifp;
596 goto hbhcheck;
597 }
598 }
599 if (lle != NULL)
600 LLE_RUNLOCK(lle);
601
602 dst = &rin6.ro_dst;
603 dst->sin6_len = sizeof(struct sockaddr_in6);
604 dst->sin6_family = AF_INET6;
605 dst->sin6_addr = ip6->ip6_dst;
606 rin6.ro_rt = rtalloc1((struct sockaddr *)dst, 0, 0);
607 if (rin6.ro_rt)
608 RT_UNLOCK(rin6.ro_rt);
609
610 #define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))
611
612 /*
613 * Accept the packet if the forwarding interface to the destination
614 * according to the routing table is the loopback interface,
615 * unless the associated route has a gateway.
616 * Note that this approach causes to accept a packet if there is a
617 * route to the loopback interface for the destination of the packet.
618 * But we think it's even useful in some situations, e.g. when using
619 * a special daemon which wants to intercept the packet.
620 *
621 * XXX: some OSes automatically make a cloned route for the destination
622 * of an outgoing packet. If the outgoing interface of the packet
623 * is a loopback one, the kernel would consider the packet to be
624 * accepted, even if we have no such address assinged on the interface.
625 * We check the cloned flag of the route entry to reject such cases,
626 * assuming that route entries for our own addresses are not made by
627 * cloning (it should be true because in6_addloop explicitly installs
628 * the host route). However, we might have to do an explicit check
629 * while it would be less efficient. Or, should we rather install a
630 * reject route for such a case?
631 */
632 if (rin6.ro_rt &&
633 (rin6.ro_rt->rt_flags &
634 (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
635 #ifdef RTF_WASCLONED
636 !(rin6.ro_rt->rt_flags & RTF_WASCLONED) &&
637 #endif
638 #ifdef RTF_CLONED
639 !(rin6.ro_rt->rt_flags & RTF_CLONED) &&
640 #endif
641 #if 0
642 /*
643 * The check below is redundant since the comparison of
644 * the destination and the key of the rtentry has
645 * already done through looking up the routing table.
646 */
647 IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
648 &rt6_key(rin6.ro_rt)->sin6_addr)
649 #endif
650 rin6.ro_rt->rt_ifp->if_type == IFT_LOOP) {
651 int free_ia6 = 0;
652 struct in6_ifaddr *ia6;
653
654 /*
655 * found the loopback route to the interface address
656 */
657 if (rin6.ro_rt->rt_gateway->sa_family == AF_LINK) {
658 struct sockaddr_in6 dest6;
659
660 bzero(&dest6, sizeof(dest6));
661 dest6.sin6_family = AF_INET6;
662 dest6.sin6_len = sizeof(dest6);
663 dest6.sin6_addr = ip6->ip6_dst;
664 ia6 = (struct in6_ifaddr *)
665 ifa_ifwithaddr((struct sockaddr *)&dest6);
666 if (ia6 == NULL)
667 goto bad;
668 free_ia6 = 1;
669 }
670 else
671 ia6 = (struct in6_ifaddr *)rin6.ro_rt->rt_ifa;
672
673 /*
674 * record address information into m_tag.
675 */
676 (void)ip6_setdstifaddr(m, ia6);
677
678 /*
679 * packets to a tentative, duplicated, or somehow invalid
680 * address must not be accepted.
681 */
682 if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
683 /* this address is ready */
684 ours = 1;
685 deliverifp = ia6->ia_ifp; /* correct? */
686 /* Count the packet in the ip address stats */
687 ia6->ia_ifa.if_ipackets++;
688 ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
689 if (ia6 != NULL && free_ia6 != 0)
690 ifa_free(&ia6->ia_ifa);
691 goto hbhcheck;
692 } else {
693 char ip6bufs[INET6_ADDRSTRLEN];
694 char ip6bufd[INET6_ADDRSTRLEN];
695 /* address is not ready, so discard the packet. */
696 nd6log((LOG_INFO,
697 "ip6_input: packet to an unready address %s->%s\n",
698 ip6_sprintf(ip6bufs, &ip6->ip6_src),
699 ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
700
701 if (ia6 != NULL && free_ia6 != 0)
702 ifa_free(&ia6->ia_ifa);
703 goto bad;
704 }
705 }
706
707 /*
708 * FAITH (Firewall Aided Internet Translator)
709 */
710 if (V_ip6_keepfaith) {
711 if (rin6.ro_rt && rin6.ro_rt->rt_ifp &&
712 rin6.ro_rt->rt_ifp->if_type == IFT_FAITH) {
713 /* XXX do we need more sanity checks? */
714 ours = 1;
715 deliverifp = rin6.ro_rt->rt_ifp; /* faith */
716 goto hbhcheck;
717 }
718 }
719
720 /*
721 * Now there is no reason to process the packet if it's not our own
722 * and we're not a router.
723 */
724 if (!V_ip6_forwarding) {
725 V_ip6stat.ip6s_cantforward++;
726 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
727 goto bad;
728 }
729
730 hbhcheck:
731 /*
732 * record address information into m_tag, if we don't have one yet.
733 * note that we are unable to record it, if the address is not listed
734 * as our interface address (e.g. multicast addresses, addresses
735 * within FAITH prefixes and such).
736 */
737 if (deliverifp) {
738 struct in6_ifaddr *ia6;
739
740 if ((ia6 = ip6_getdstifaddr(m)) != NULL) {
741 ifa_free(&ia6->ia_ifa);
742 } else {
743 ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
744 if (ia6) {
745 if (!ip6_setdstifaddr(m, ia6)) {
746 /*
747 * XXX maybe we should drop the packet here,
748 * as we could not provide enough information
749 * to the upper layers.
750 */
751 }
752 ifa_free(&ia6->ia_ifa);
753 }
754 }
755 }
756
757 /*
758 * Process Hop-by-Hop options header if it's contained.
759 * m may be modified in ip6_hopopts_input().
760 * If a JumboPayload option is included, plen will also be modified.
761 */
762 plen = (u_int32_t)ntohs(ip6->ip6_plen);
763 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
764 struct ip6_hbh *hbh;
765
766 if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) {
767 #if 0 /*touches NULL pointer*/
768 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
769 #endif
770 goto out; /* m have already been freed */
771 }
772
773 /* adjust pointer */
774 ip6 = mtod(m, struct ip6_hdr *);
775
776 /*
777 * if the payload length field is 0 and the next header field
778 * indicates Hop-by-Hop Options header, then a Jumbo Payload
779 * option MUST be included.
780 */
781 if (ip6->ip6_plen == 0 && plen == 0) {
782 /*
783 * Note that if a valid jumbo payload option is
784 * contained, ip6_hopopts_input() must set a valid
785 * (non-zero) payload length to the variable plen.
786 */
787 V_ip6stat.ip6s_badoptions++;
788 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
789 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
790 icmp6_error(m, ICMP6_PARAM_PROB,
791 ICMP6_PARAMPROB_HEADER,
792 (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
793 goto out;
794 }
795 #ifndef PULLDOWN_TEST
796 /* ip6_hopopts_input() ensures that mbuf is contiguous */
797 hbh = (struct ip6_hbh *)(ip6 + 1);
798 #else
799 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
800 sizeof(struct ip6_hbh));
801 if (hbh == NULL) {
802 V_ip6stat.ip6s_tooshort++;
803 goto out;
804 }
805 #endif
806 nxt = hbh->ip6h_nxt;
807
808 /*
809 * If we are acting as a router and the packet contains a
810 * router alert option, see if we know the option value.
811 * Currently, we only support the option value for MLD, in which
812 * case we should pass the packet to the multicast routing
813 * daemon.
814 */
815 if (rtalert != ~0) {
816 switch (rtalert) {
817 case IP6OPT_RTALERT_MLD:
818 if (V_ip6_forwarding)
819 ours = 1;
820 break;
821 default:
822 /*
823 * RFC2711 requires unrecognized values must be
824 * silently ignored.
825 */
826 break;
827 }
828 }
829 } else
830 nxt = ip6->ip6_nxt;
831
832 /*
833 * Check that the amount of data in the buffers
834 * is as at least much as the IPv6 header would have us expect.
835 * Trim mbufs if longer than we expect.
836 * Drop packet if shorter than we expect.
837 */
838 if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
839 V_ip6stat.ip6s_tooshort++;
840 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
841 goto bad;
842 }
843 if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
844 if (m->m_len == m->m_pkthdr.len) {
845 m->m_len = sizeof(struct ip6_hdr) + plen;
846 m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
847 } else
848 m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
849 }
850
851 /*
852 * Forward if desirable.
853 */
854 if (V_ip6_mrouter &&
855 IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
856 /*
857 * If we are acting as a multicast router, all
858 * incoming multicast packets are passed to the
859 * kernel-level multicast forwarding function.
860 * The packet is returned (relatively) intact; if
861 * ip6_mforward() returns a non-zero value, the packet
862 * must be discarded, else it may be accepted below.
863 *
864 * XXX TODO: Check hlim and multicast scope here to avoid
865 * unnecessarily calling into ip6_mforward().
866 */
867 if (ip6_mforward &&
868 ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
869 IP6STAT_INC(ip6s_cantforward);
870 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
871 goto bad;
872 }
873 } else if (!ours) {
874 ip6_forward(m, srcrt);
875 goto out;
876 }
877
878 ip6 = mtod(m, struct ip6_hdr *);
879
880 /*
881 * Malicious party may be able to use IPv4 mapped addr to confuse
882 * tcp/udp stack and bypass security checks (act as if it was from
883 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious.
884 *
885 * For SIIT end node behavior, you may want to disable the check.
886 * However, you will become vulnerable to attacks using IPv4 mapped
887 * source.
888 */
889 if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
890 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
891 V_ip6stat.ip6s_badscope++;
892 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
893 goto bad;
894 }
895
896 /*
897 * Tell launch routine the next header
898 */
899 V_ip6stat.ip6s_delivered++;
900 in6_ifstat_inc(deliverifp, ifs6_in_deliver);
901 nest = 0;
902
903 while (nxt != IPPROTO_DONE) {
904 if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
905 V_ip6stat.ip6s_toomanyhdr++;
906 goto bad;
907 }
908
909 /*
910 * protection against faulty packet - there should be
911 * more sanity checks in header chain processing.
912 */
913 if (m->m_pkthdr.len < off) {
914 V_ip6stat.ip6s_tooshort++;
915 in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
916 goto bad;
917 }
918
919 #ifdef IPSEC
920 /*
921 * enforce IPsec policy checking if we are seeing last header.
922 * note that we do not visit this with protocols with pcb layer
923 * code - like udp/tcp/raw ip.
924 */
925 if (ip6_ipsec_input(m, nxt))
926 goto bad;
927 #endif /* IPSEC */
928
929 /*
930 * Use mbuf flags to propagate Router Alert option to
931 * ICMPv6 layer, as hop-by-hop options have been stripped.
932 */
933 if (nxt == IPPROTO_ICMPV6 && rtalert != ~0)
934 m->m_flags |= M_RTALERT_MLD;
935
936 nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
937 }
938 goto out;
939 bad:
940 m_freem(m);
941 out:
942 if (rin6.ro_rt)
943 RTFREE(rin6.ro_rt);
944 }
945
946 /*
947 * set/grab in6_ifaddr correspond to IPv6 destination address.
948 * XXX backward compatibility wrapper
949 *
950 * XXXRW: We should bump the refcount on ia6 before sticking it in the m_tag,
951 * and then bump it when the tag is copied, and release it when the tag is
952 * freed. Unfortunately, m_tags don't support deep copies (yet), so instead
953 * we just bump the ia refcount when we receive it. This should be fixed.
954 */
955 static struct ip6aux *
956 ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6)
957 {
958 struct ip6aux *ip6a;
959
960 ip6a = ip6_addaux(m);
961 if (ip6a)
962 ip6a->ip6a_dstia6 = ia6;
963 return ip6a; /* NULL if failed to set */
964 }
965
966 struct in6_ifaddr *
967 ip6_getdstifaddr(struct mbuf *m)
968 {
969 struct ip6aux *ip6a;
970 struct in6_ifaddr *ia;
971
972 ip6a = ip6_findaux(m);
973 if (ip6a) {
974 ia = ip6a->ip6a_dstia6;
975 ifa_ref(&ia->ia_ifa);
976 return ia;
977 } else
978 return NULL;
979 }
980
981 /*
982 * Hop-by-Hop options header processing. If a valid jumbo payload option is
983 * included, the real payload length will be stored in plenp.
984 *
985 * rtalertp - XXX: should be stored more smart way
986 */
987 static int
988 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp,
989 struct mbuf **mp, int *offp)
990 {
991 struct mbuf *m = *mp;
992 int off = *offp, hbhlen;
993 struct ip6_hbh *hbh;
994 u_int8_t *opt;
995
996 /* validation of the length of the header */
997 #ifndef PULLDOWN_TEST
998 IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1);
999 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
1000 hbhlen = (hbh->ip6h_len + 1) << 3;
1001
1002 IP6_EXTHDR_CHECK(m, off, hbhlen, -1);
1003 hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
1004 #else
1005 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
1006 sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
1007 if (hbh == NULL) {
1008 V_ip6stat.ip6s_tooshort++;
1009 return -1;
1010 }
1011 hbhlen = (hbh->ip6h_len + 1) << 3;
1012 IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
1013 hbhlen);
1014 if (hbh == NULL) {
1015 V_ip6stat.ip6s_tooshort++;
1016 return -1;
1017 }
1018 #endif
1019 off += hbhlen;
1020 hbhlen -= sizeof(struct ip6_hbh);
1021 opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh);
1022
1023 if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
1024 hbhlen, rtalertp, plenp) < 0)
1025 return (-1);
1026
1027 *offp = off;
1028 *mp = m;
1029 return (0);
1030 }
1031
1032 /*
1033 * Search header for all Hop-by-hop options and process each option.
1034 * This function is separate from ip6_hopopts_input() in order to
1035 * handle a case where the sending node itself process its hop-by-hop
1036 * options header. In such a case, the function is called from ip6_output().
1037 *
1038 * The function assumes that hbh header is located right after the IPv6 header
1039 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
1040 * opthead + hbhlen is located in continuous memory region.
1041 */
1042 int
1043 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen,
1044 u_int32_t *rtalertp, u_int32_t *plenp)
1045 {
1046 struct ip6_hdr *ip6;
1047 int optlen = 0;
1048 u_int8_t *opt = opthead;
1049 u_int16_t rtalert_val;
1050 u_int32_t jumboplen;
1051 const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
1052
1053 for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
1054 switch (*opt) {
1055 case IP6OPT_PAD1:
1056 optlen = 1;
1057 break;
1058 case IP6OPT_PADN:
1059 if (hbhlen < IP6OPT_MINLEN) {
1060 V_ip6stat.ip6s_toosmall++;
1061 goto bad;
1062 }
1063 optlen = *(opt + 1) + 2;
1064 break;
1065 case IP6OPT_ROUTER_ALERT:
1066 /* XXX may need check for alignment */
1067 if (hbhlen < IP6OPT_RTALERT_LEN) {
1068 V_ip6stat.ip6s_toosmall++;
1069 goto bad;
1070 }
1071 if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
1072 /* XXX stat */
1073 icmp6_error(m, ICMP6_PARAM_PROB,
1074 ICMP6_PARAMPROB_HEADER,
1075 erroff + opt + 1 - opthead);
1076 return (-1);
1077 }
1078 optlen = IP6OPT_RTALERT_LEN;
1079 bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
1080 *rtalertp = ntohs(rtalert_val);
1081 break;
1082 case IP6OPT_JUMBO:
1083 /* XXX may need check for alignment */
1084 if (hbhlen < IP6OPT_JUMBO_LEN) {
1085 V_ip6stat.ip6s_toosmall++;
1086 goto bad;
1087 }
1088 if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
1089 /* XXX stat */
1090 icmp6_error(m, ICMP6_PARAM_PROB,
1091 ICMP6_PARAMPROB_HEADER,
1092 erroff + opt + 1 - opthead);
1093 return (-1);
1094 }
1095 optlen = IP6OPT_JUMBO_LEN;
1096
1097 /*
1098 * IPv6 packets that have non 0 payload length
1099 * must not contain a jumbo payload option.
1100 */
1101 ip6 = mtod(m, struct ip6_hdr *);
1102 if (ip6->ip6_plen) {
1103 V_ip6stat.ip6s_badoptions++;
1104 icmp6_error(m, ICMP6_PARAM_PROB,
1105 ICMP6_PARAMPROB_HEADER,
1106 erroff + opt - opthead);
1107 return (-1);
1108 }
1109
1110 /*
1111 * We may see jumbolen in unaligned location, so
1112 * we'd need to perform bcopy().
1113 */
1114 bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
1115 jumboplen = (u_int32_t)htonl(jumboplen);
1116
1117 #if 1
1118 /*
1119 * if there are multiple jumbo payload options,
1120 * *plenp will be non-zero and the packet will be
1121 * rejected.
1122 * the behavior may need some debate in ipngwg -
1123 * multiple options does not make sense, however,
1124 * there's no explicit mention in specification.
1125 */
1126 if (*plenp != 0) {
1127 V_ip6stat.ip6s_badoptions++;
1128 icmp6_error(m, ICMP6_PARAM_PROB,
1129 ICMP6_PARAMPROB_HEADER,
1130 erroff + opt + 2 - opthead);
1131 return (-1);
1132 }
1133 #endif
1134
1135 /*
1136 * jumbo payload length must be larger than 65535.
1137 */
1138 if (jumboplen <= IPV6_MAXPACKET) {
1139 V_ip6stat.ip6s_badoptions++;
1140 icmp6_error(m, ICMP6_PARAM_PROB,
1141 ICMP6_PARAMPROB_HEADER,
1142 erroff + opt + 2 - opthead);
1143 return (-1);
1144 }
1145 *plenp = jumboplen;
1146
1147 break;
1148 default: /* unknown option */
1149 if (hbhlen < IP6OPT_MINLEN) {
1150 V_ip6stat.ip6s_toosmall++;
1151 goto bad;
1152 }
1153 optlen = ip6_unknown_opt(opt, m,
1154 erroff + opt - opthead);
1155 if (optlen == -1)
1156 return (-1);
1157 optlen += 2;
1158 break;
1159 }
1160 }
1161
1162 return (0);
1163
1164 bad:
1165 m_freem(m);
1166 return (-1);
1167 }
1168
1169 /*
1170 * Unknown option processing.
1171 * The third argument `off' is the offset from the IPv6 header to the option,
1172 * which is necessary if the IPv6 header the and option header and IPv6 header
1173 * is not continuous in order to return an ICMPv6 error.
1174 */
1175 int
1176 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off)
1177 {
1178 struct ip6_hdr *ip6;
1179
1180 switch (IP6OPT_TYPE(*optp)) {
1181 case IP6OPT_TYPE_SKIP: /* ignore the option */
1182 return ((int)*(optp + 1));
1183 case IP6OPT_TYPE_DISCARD: /* silently discard */
1184 m_freem(m);
1185 return (-1);
1186 case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
1187 V_ip6stat.ip6s_badoptions++;
1188 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
1189 return (-1);
1190 case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
1191 V_ip6stat.ip6s_badoptions++;
1192 ip6 = mtod(m, struct ip6_hdr *);
1193 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
1194 (m->m_flags & (M_BCAST|M_MCAST)))
1195 m_freem(m);
1196 else
1197 icmp6_error(m, ICMP6_PARAM_PROB,
1198 ICMP6_PARAMPROB_OPTION, off);
1199 return (-1);
1200 }
1201
1202 m_freem(m); /* XXX: NOTREACHED */
1203 return (-1);
1204 }
1205
1206 /*
1207 * Create the "control" list for this pcb.
1208 * These functions will not modify mbuf chain at all.
1209 *
1210 * With KAME mbuf chain restriction:
1211 * The routine will be called from upper layer handlers like tcp6_input().
1212 * Thus the routine assumes that the caller (tcp6_input) have already
1213 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the
1214 * very first mbuf on the mbuf chain.
1215 *
1216 * ip6_savecontrol_v4 will handle those options that are possible to be
1217 * set on a v4-mapped socket.
1218 * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those
1219 * options and handle the v6-only ones itself.
1220 */
1221 struct mbuf **
1222 ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp,
1223 int *v4only)
1224 {
1225 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1226
1227 #ifdef SO_TIMESTAMP
1228 if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) {
1229 struct timeval tv;
1230
1231 microtime(&tv);
1232 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1233 SCM_TIMESTAMP, SOL_SOCKET);
1234 if (*mp)
1235 mp = &(*mp)->m_next;
1236 }
1237 #endif
1238
1239 if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
1240 if (v4only != NULL)
1241 *v4only = 1;
1242 return (mp);
1243 }
1244
1245 #define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y))
1246 /* RFC 2292 sec. 5 */
1247 if ((inp->inp_flags & IN6P_PKTINFO) != 0) {
1248 struct in6_pktinfo pi6;
1249
1250 bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
1251 in6_clearscope(&pi6.ipi6_addr); /* XXX */
1252 pi6.ipi6_ifindex =
1253 (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0;
1254
1255 *mp = sbcreatecontrol((caddr_t) &pi6,
1256 sizeof(struct in6_pktinfo),
1257 IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6);
1258 if (*mp)
1259 mp = &(*mp)->m_next;
1260 }
1261
1262 if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) {
1263 int hlim = ip6->ip6_hlim & 0xff;
1264
1265 *mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int),
1266 IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT),
1267 IPPROTO_IPV6);
1268 if (*mp)
1269 mp = &(*mp)->m_next;
1270 }
1271
1272 if (v4only != NULL)
1273 *v4only = 0;
1274 return (mp);
1275 }
1276
1277 void
1278 ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp)
1279 {
1280 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1281 int v4only = 0;
1282
1283 mp = ip6_savecontrol_v4(in6p, m, mp, &v4only);
1284 if (v4only)
1285 return;
1286
1287 if ((in6p->inp_flags & IN6P_TCLASS) != 0) {
1288 u_int32_t flowinfo;
1289 int tclass;
1290
1291 flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
1292 flowinfo >>= 20;
1293
1294 tclass = flowinfo & 0xff;
1295 *mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass),
1296 IPV6_TCLASS, IPPROTO_IPV6);
1297 if (*mp)
1298 mp = &(*mp)->m_next;
1299 }
1300
1301 /*
1302 * IPV6_HOPOPTS socket option. Recall that we required super-user
1303 * privilege for the option (see ip6_ctloutput), but it might be too
1304 * strict, since there might be some hop-by-hop options which can be
1305 * returned to normal user.
1306 * See also RFC 2292 section 6 (or RFC 3542 section 8).
1307 */
1308 if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) {
1309 /*
1310 * Check if a hop-by-hop options header is contatined in the
1311 * received packet, and if so, store the options as ancillary
1312 * data. Note that a hop-by-hop options header must be
1313 * just after the IPv6 header, which is assured through the
1314 * IPv6 input processing.
1315 */
1316 if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
1317 struct ip6_hbh *hbh;
1318 int hbhlen = 0;
1319 #ifdef PULLDOWN_TEST
1320 struct mbuf *ext;
1321 #endif
1322
1323 #ifndef PULLDOWN_TEST
1324 hbh = (struct ip6_hbh *)(ip6 + 1);
1325 hbhlen = (hbh->ip6h_len + 1) << 3;
1326 #else
1327 ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
1328 ip6->ip6_nxt);
1329 if (ext == NULL) {
1330 V_ip6stat.ip6s_tooshort++;
1331 return;
1332 }
1333 hbh = mtod(ext, struct ip6_hbh *);
1334 hbhlen = (hbh->ip6h_len + 1) << 3;
1335 if (hbhlen != ext->m_len) {
1336 m_freem(ext);
1337 V_ip6stat.ip6s_tooshort++;
1338 return;
1339 }
1340 #endif
1341
1342 /*
1343 * XXX: We copy the whole header even if a
1344 * jumbo payload option is included, the option which
1345 * is to be removed before returning according to
1346 * RFC2292.
1347 * Note: this constraint is removed in RFC3542
1348 */
1349 *mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
1350 IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS),
1351 IPPROTO_IPV6);
1352 if (*mp)
1353 mp = &(*mp)->m_next;
1354 #ifdef PULLDOWN_TEST
1355 m_freem(ext);
1356 #endif
1357 }
1358 }
1359
1360 if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) {
1361 int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
1362
1363 /*
1364 * Search for destination options headers or routing
1365 * header(s) through the header chain, and stores each
1366 * header as ancillary data.
1367 * Note that the order of the headers remains in
1368 * the chain of ancillary data.
1369 */
1370 while (1) { /* is explicit loop prevention necessary? */
1371 struct ip6_ext *ip6e = NULL;
1372 int elen;
1373 #ifdef PULLDOWN_TEST
1374 struct mbuf *ext = NULL;
1375 #endif
1376
1377 /*
1378 * if it is not an extension header, don't try to
1379 * pull it from the chain.
1380 */
1381 switch (nxt) {
1382 case IPPROTO_DSTOPTS:
1383 case IPPROTO_ROUTING:
1384 case IPPROTO_HOPOPTS:
1385 case IPPROTO_AH: /* is it possible? */
1386 break;
1387 default:
1388 goto loopend;
1389 }
1390
1391 #ifndef PULLDOWN_TEST
1392 if (off + sizeof(*ip6e) > m->m_len)
1393 goto loopend;
1394 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
1395 if (nxt == IPPROTO_AH)
1396 elen = (ip6e->ip6e_len + 2) << 2;
1397 else
1398 elen = (ip6e->ip6e_len + 1) << 3;
1399 if (off + elen > m->m_len)
1400 goto loopend;
1401 #else
1402 ext = ip6_pullexthdr(m, off, nxt);
1403 if (ext == NULL) {
1404 V_ip6stat.ip6s_tooshort++;
1405 return;
1406 }
1407 ip6e = mtod(ext, struct ip6_ext *);
1408 if (nxt == IPPROTO_AH)
1409 elen = (ip6e->ip6e_len + 2) << 2;
1410 else
1411 elen = (ip6e->ip6e_len + 1) << 3;
1412 if (elen != ext->m_len) {
1413 m_freem(ext);
1414 V_ip6stat.ip6s_tooshort++;
1415 return;
1416 }
1417 #endif
1418
1419 switch (nxt) {
1420 case IPPROTO_DSTOPTS:
1421 if (!(in6p->inp_flags & IN6P_DSTOPTS))
1422 break;
1423
1424 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1425 IS2292(in6p,
1426 IPV6_2292DSTOPTS, IPV6_DSTOPTS),
1427 IPPROTO_IPV6);
1428 if (*mp)
1429 mp = &(*mp)->m_next;
1430 break;
1431 case IPPROTO_ROUTING:
1432 if (!in6p->inp_flags & IN6P_RTHDR)
1433 break;
1434
1435 *mp = sbcreatecontrol((caddr_t)ip6e, elen,
1436 IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR),
1437 IPPROTO_IPV6);
1438 if (*mp)
1439 mp = &(*mp)->m_next;
1440 break;
1441 case IPPROTO_HOPOPTS:
1442 case IPPROTO_AH: /* is it possible? */
1443 break;
1444
1445 default:
1446 /*
1447 * other cases have been filtered in the above.
1448 * none will visit this case. here we supply
1449 * the code just in case (nxt overwritten or
1450 * other cases).
1451 */
1452 #ifdef PULLDOWN_TEST
1453 m_freem(ext);
1454 #endif
1455 goto loopend;
1456
1457 }
1458
1459 /* proceed with the next header. */
1460 off += elen;
1461 nxt = ip6e->ip6e_nxt;
1462 ip6e = NULL;
1463 #ifdef PULLDOWN_TEST
1464 m_freem(ext);
1465 ext = NULL;
1466 #endif
1467 }
1468 loopend:
1469 ;
1470 }
1471 }
1472 #undef IS2292
1473
1474 void
1475 ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu)
1476 {
1477 struct socket *so;
1478 struct mbuf *m_mtu;
1479 struct ip6_mtuinfo mtuctl;
1480
1481 so = in6p->inp_socket;
1482
1483 if (mtu == NULL)
1484 return;
1485
1486 #ifdef DIAGNOSTIC
1487 if (so == NULL) /* I believe this is impossible */
1488 panic("ip6_notify_pmtu: socket is NULL");
1489 #endif
1490
1491 bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */
1492 mtuctl.ip6m_mtu = *mtu;
1493 mtuctl.ip6m_addr = *dst;
1494 if (sa6_recoverscope(&mtuctl.ip6m_addr))
1495 return;
1496
1497 if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl),
1498 IPV6_PATHMTU, IPPROTO_IPV6)) == NULL)
1499 return;
1500
1501 if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu)
1502 == 0) {
1503 m_freem(m_mtu);
1504 /* XXX: should count statistics */
1505 } else
1506 sorwakeup(so);
1507
1508 return;
1509 }
1510
1511 #ifdef PULLDOWN_TEST
1512 /*
1513 * pull single extension header from mbuf chain. returns single mbuf that
1514 * contains the result, or NULL on error.
1515 */
1516 static struct mbuf *
1517 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt)
1518 {
1519 struct ip6_ext ip6e;
1520 size_t elen;
1521 struct mbuf *n;
1522
1523 #ifdef DIAGNOSTIC
1524 switch (nxt) {
1525 case IPPROTO_DSTOPTS:
1526 case IPPROTO_ROUTING:
1527 case IPPROTO_HOPOPTS:
1528 case IPPROTO_AH: /* is it possible? */
1529 break;
1530 default:
1531 printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
1532 }
1533 #endif
1534
1535 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1536 if (nxt == IPPROTO_AH)
1537 elen = (ip6e.ip6e_len + 2) << 2;
1538 else
1539 elen = (ip6e.ip6e_len + 1) << 3;
1540
1541 MGET(n, M_DONTWAIT, MT_DATA);
1542 if (n && elen >= MLEN) {
1543 MCLGET(n, M_DONTWAIT);
1544 if ((n->m_flags & M_EXT) == 0) {
1545 m_free(n);
1546 n = NULL;
1547 }
1548 }
1549 if (!n)
1550 return NULL;
1551
1552 n->m_len = 0;
1553 if (elen >= M_TRAILINGSPACE(n)) {
1554 m_free(n);
1555 return NULL;
1556 }
1557
1558 m_copydata(m, off, elen, mtod(n, caddr_t));
1559 n->m_len = elen;
1560 return n;
1561 }
1562 #endif
1563
1564 /*
1565 * Get pointer to the previous header followed by the header
1566 * currently processed.
1567 * XXX: This function supposes that
1568 * M includes all headers,
1569 * the next header field and the header length field of each header
1570 * are valid, and
1571 * the sum of each header length equals to OFF.
1572 * Because of these assumptions, this function must be called very
1573 * carefully. Moreover, it will not be used in the near future when
1574 * we develop `neater' mechanism to process extension headers.
1575 */
1576 char *
1577 ip6_get_prevhdr(struct mbuf *m, int off)
1578 {
1579 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1580
1581 if (off == sizeof(struct ip6_hdr))
1582 return (&ip6->ip6_nxt);
1583 else {
1584 int len, nxt;
1585 struct ip6_ext *ip6e = NULL;
1586
1587 nxt = ip6->ip6_nxt;
1588 len = sizeof(struct ip6_hdr);
1589 while (len < off) {
1590 ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);
1591
1592 switch (nxt) {
1593 case IPPROTO_FRAGMENT:
1594 len += sizeof(struct ip6_frag);
1595 break;
1596 case IPPROTO_AH:
1597 len += (ip6e->ip6e_len + 2) << 2;
1598 break;
1599 default:
1600 len += (ip6e->ip6e_len + 1) << 3;
1601 break;
1602 }
1603 nxt = ip6e->ip6e_nxt;
1604 }
1605 if (ip6e)
1606 return (&ip6e->ip6e_nxt);
1607 else
1608 return NULL;
1609 }
1610 }
1611
1612 /*
1613 * get next header offset. m will be retained.
1614 */
1615 int
1616 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp)
1617 {
1618 struct ip6_hdr ip6;
1619 struct ip6_ext ip6e;
1620 struct ip6_frag fh;
1621
1622 /* just in case */
1623 if (m == NULL)
1624 panic("ip6_nexthdr: m == NULL");
1625 if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
1626 return -1;
1627
1628 switch (proto) {
1629 case IPPROTO_IPV6:
1630 if (m->m_pkthdr.len < off + sizeof(ip6))
1631 return -1;
1632 m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
1633 if (nxtp)
1634 *nxtp = ip6.ip6_nxt;
1635 off += sizeof(ip6);
1636 return off;
1637
1638 case IPPROTO_FRAGMENT:
1639 /*
1640 * terminate parsing if it is not the first fragment,
1641 * it does not make sense to parse through it.
1642 */
1643 if (m->m_pkthdr.len < off + sizeof(fh))
1644 return -1;
1645 m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
1646 /* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */
1647 if (fh.ip6f_offlg & IP6F_OFF_MASK)
1648 return -1;
1649 if (nxtp)
1650 *nxtp = fh.ip6f_nxt;
1651 off += sizeof(struct ip6_frag);
1652 return off;
1653
1654 case IPPROTO_AH:
1655 if (m->m_pkthdr.len < off + sizeof(ip6e))
1656 return -1;
1657 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1658 if (nxtp)
1659 *nxtp = ip6e.ip6e_nxt;
1660 off += (ip6e.ip6e_len + 2) << 2;
1661 return off;
1662
1663 case IPPROTO_HOPOPTS:
1664 case IPPROTO_ROUTING:
1665 case IPPROTO_DSTOPTS:
1666 if (m->m_pkthdr.len < off + sizeof(ip6e))
1667 return -1;
1668 m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
1669 if (nxtp)
1670 *nxtp = ip6e.ip6e_nxt;
1671 off += (ip6e.ip6e_len + 1) << 3;
1672 return off;
1673
1674 case IPPROTO_NONE:
1675 case IPPROTO_ESP:
1676 case IPPROTO_IPCOMP:
1677 /* give up */
1678 return -1;
1679
1680 default:
1681 return -1;
1682 }
1683
1684 return -1;
1685 }
1686
1687 /*
1688 * get offset for the last header in the chain. m will be kept untainted.
1689 */
1690 int
1691 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp)
1692 {
1693 int newoff;
1694 int nxt;
1695
1696 if (!nxtp) {
1697 nxt = -1;
1698 nxtp = &nxt;
1699 }
1700 while (1) {
1701 newoff = ip6_nexthdr(m, off, proto, nxtp);
1702 if (newoff < 0)
1703 return off;
1704 else if (newoff < off)
1705 return -1; /* invalid */
1706 else if (newoff == off)
1707 return newoff;
1708
1709 off = newoff;
1710 proto = *nxtp;
1711 }
1712 }
1713
1714 struct ip6aux *
1715 ip6_addaux(struct mbuf *m)
1716 {
1717 struct m_tag *mtag;
1718
1719 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1720 if (!mtag) {
1721 mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux),
1722 M_NOWAIT);
1723 if (mtag) {
1724 m_tag_prepend(m, mtag);
1725 bzero(mtag + 1, sizeof(struct ip6aux));
1726 }
1727 }
1728 return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1729 }
1730
1731 struct ip6aux *
1732 ip6_findaux(struct mbuf *m)
1733 {
1734 struct m_tag *mtag;
1735
1736 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1737 return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
1738 }
1739
1740 void
1741 ip6_delaux(struct mbuf *m)
1742 {
1743 struct m_tag *mtag;
1744
1745 mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
1746 if (mtag)
1747 m_tag_delete(m, mtag);
1748 }
1749
1750 /*
1751 * System control for IP6
1752 */
1753
1754 u_char inet6ctlerrmap[PRC_NCMDS] = {
1755 0, 0, 0, 0,
1756 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1757 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1758 EMSGSIZE, EHOSTUNREACH, 0, 0,
1759 0, 0, 0, 0,
1760 ENOPROTOOPT
1761 };
Cache object: 60a3258c628ab79c68bf005db79fcce4
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