xref: /netbsd-src/sys/netinet6/ip6_input.c (revision 7863ba460b0a05b553c754e5dbc29247dddec322)
1 /*	$NetBSD: ip6_input.c,v 1.195 2018/03/21 14:23:54 roy Exp $	*/
2 /*	$KAME: ip6_input.c,v 1.188 2001/03/29 05:34:31 itojun Exp $	*/
3 
4 /*
5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1982, 1986, 1988, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  *
61  *	@(#)ip_input.c	8.2 (Berkeley) 1/4/94
62  */
63 
64 #include <sys/cdefs.h>
65 __KERNEL_RCSID(0, "$NetBSD: ip6_input.c,v 1.195 2018/03/21 14:23:54 roy Exp $");
66 
67 #ifdef _KERNEL_OPT
68 #include "opt_gateway.h"
69 #include "opt_inet.h"
70 #include "opt_inet6.h"
71 #include "opt_ipsec.h"
72 #include "opt_net_mpsafe.h"
73 #endif
74 
75 #include <sys/param.h>
76 #include <sys/systm.h>
77 #include <sys/mbuf.h>
78 #include <sys/domain.h>
79 #include <sys/protosw.h>
80 #include <sys/socket.h>
81 #include <sys/socketvar.h>
82 #include <sys/errno.h>
83 #include <sys/time.h>
84 #include <sys/kernel.h>
85 #include <sys/syslog.h>
86 #include <sys/proc.h>
87 #include <sys/sysctl.h>
88 #include <sys/cprng.h>
89 #include <sys/percpu.h>
90 
91 #include <net/if.h>
92 #include <net/if_types.h>
93 #include <net/if_dl.h>
94 #include <net/route.h>
95 #include <net/pktqueue.h>
96 #include <net/pfil.h>
97 
98 #include <netinet/in.h>
99 #include <netinet/in_systm.h>
100 #ifdef INET
101 #include <netinet/ip.h>
102 #include <netinet/ip_var.h>
103 #include <netinet/ip_icmp.h>
104 #endif /* INET */
105 #include <netinet/ip6.h>
106 #include <netinet/portalgo.h>
107 #include <netinet6/in6_var.h>
108 #include <netinet6/ip6_var.h>
109 #include <netinet6/ip6_private.h>
110 #include <netinet6/in6_pcb.h>
111 #include <netinet/icmp6.h>
112 #include <netinet6/scope6_var.h>
113 #include <netinet6/in6_ifattach.h>
114 #include <netinet6/nd6.h>
115 
116 #ifdef IPSEC
117 #include <netipsec/ipsec.h>
118 #include <netipsec/ipsec6.h>
119 #include <netipsec/key.h>
120 #endif /* IPSEC */
121 
122 #include <netinet6/ip6protosw.h>
123 
124 #include "faith.h"
125 
126 #include <net/net_osdep.h>
127 
128 extern struct domain inet6domain;
129 
130 u_char ip6_protox[IPPROTO_MAX];
131 pktqueue_t *ip6_pktq __read_mostly;
132 
133 pfil_head_t *inet6_pfil_hook;
134 
135 percpu_t *ip6stat_percpu;
136 
137 percpu_t *ip6_forward_rt_percpu __cacheline_aligned;
138 
139 static void ip6_init2(void);
140 static void ip6intr(void *);
141 static struct m_tag *ip6_setdstifaddr(struct mbuf *, const struct in6_ifaddr *);
142 
143 static int ip6_process_hopopts(struct mbuf *, u_int8_t *, int, u_int32_t *,
144     u_int32_t *);
145 static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int);
146 static void sysctl_net_inet6_ip6_setup(struct sysctllog **);
147 
148 #ifdef NET_MPSAFE
149 #define	SOFTNET_LOCK()		mutex_enter(softnet_lock)
150 #define	SOFTNET_UNLOCK()	mutex_exit(softnet_lock)
151 #else
152 #define	SOFTNET_LOCK()		KASSERT(mutex_owned(softnet_lock))
153 #define	SOFTNET_UNLOCK()	KASSERT(mutex_owned(softnet_lock))
154 #endif
155 
156 /*
157  * IP6 initialization: fill in IP6 protocol switch table.
158  * All protocols not implemented in kernel go to raw IP6 protocol handler.
159  */
160 void
161 ip6_init(void)
162 {
163 	const struct ip6protosw *pr;
164 	int i;
165 
166 	in6_init();
167 
168 	sysctl_net_inet6_ip6_setup(NULL);
169 	pr = (const struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
170 	if (pr == 0)
171 		panic("ip6_init");
172 	for (i = 0; i < IPPROTO_MAX; i++)
173 		ip6_protox[i] = pr - inet6sw;
174 	for (pr = (const struct ip6protosw *)inet6domain.dom_protosw;
175 	    pr < (const struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++)
176 		if (pr->pr_domain->dom_family == PF_INET6 &&
177 		    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
178 			ip6_protox[pr->pr_protocol] = pr - inet6sw;
179 
180 	ip6_pktq = pktq_create(IFQ_MAXLEN, ip6intr, NULL);
181 	KASSERT(ip6_pktq != NULL);
182 
183 	scope6_init();
184 	addrsel_policy_init();
185 	nd6_init();
186 	frag6_init();
187 	ip6_desync_factor = cprng_fast32() % MAX_TEMP_DESYNC_FACTOR;
188 
189 	ip6_init2();
190 #ifdef GATEWAY
191 	ip6flow_init(ip6_hashsize);
192 #endif
193 	/* Register our Packet Filter hook. */
194 	inet6_pfil_hook = pfil_head_create(PFIL_TYPE_AF, (void *)AF_INET6);
195 	KASSERT(inet6_pfil_hook != NULL);
196 
197 	ip6stat_percpu = percpu_alloc(sizeof(uint64_t) * IP6_NSTATS);
198 	ip6_forward_rt_percpu = percpu_alloc(sizeof(struct route));
199 }
200 
201 static void
202 ip6_init2(void)
203 {
204 
205 	/* timer for regeneration of temporary addresses randomize ID */
206 	callout_init(&in6_tmpaddrtimer_ch, CALLOUT_MPSAFE);
207 	callout_reset(&in6_tmpaddrtimer_ch,
208 		      (ip6_temp_preferred_lifetime - ip6_desync_factor -
209 		       ip6_temp_regen_advance) * hz,
210 		      in6_tmpaddrtimer, NULL);
211 }
212 
213 /*
214  * IP6 input interrupt handling. Just pass the packet to ip6_input.
215  */
216 static void
217 ip6intr(void *arg __unused)
218 {
219 	struct mbuf *m;
220 
221 	SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE();
222 	while ((m = pktq_dequeue(ip6_pktq)) != NULL) {
223 		struct psref psref;
224 		struct ifnet *rcvif = m_get_rcvif_psref(m, &psref);
225 
226 		if (rcvif == NULL) {
227 			m_freem(m);
228 			continue;
229 		}
230 		/*
231 		 * Drop the packet if IPv6 is disabled on the interface.
232 		 */
233 		if ((ND_IFINFO(rcvif)->flags & ND6_IFF_IFDISABLED)) {
234 			m_put_rcvif_psref(rcvif, &psref);
235 			m_freem(m);
236 			continue;
237 		}
238 		ip6_input(m, rcvif);
239 		m_put_rcvif_psref(rcvif, &psref);
240 	}
241 	SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE();
242 }
243 
244 void
245 ip6_input(struct mbuf *m, struct ifnet *rcvif)
246 {
247 	struct ip6_hdr *ip6;
248 	int hit, off = sizeof(struct ip6_hdr), nest;
249 	u_int32_t plen;
250 	u_int32_t rtalert = ~0;
251 	int nxt, ours = 0, rh_present = 0, frg_present;
252 	struct ifnet *deliverifp = NULL;
253 	int srcrt = 0;
254 	struct rtentry *rt = NULL;
255 	union {
256 		struct sockaddr		dst;
257 		struct sockaddr_in6	dst6;
258 	} u;
259 	struct route *ro;
260 
261 	KASSERT(rcvif != NULL);
262 
263 	/*
264 	 * make sure we don't have onion peering information into m_tag.
265 	 */
266 	ip6_delaux(m);
267 
268 	/*
269 	 * mbuf statistics
270 	 */
271 	if (m->m_flags & M_EXT) {
272 		if (m->m_next)
273 			IP6_STATINC(IP6_STAT_MEXT2M);
274 		else
275 			IP6_STATINC(IP6_STAT_MEXT1);
276 	} else {
277 #define M2MMAX	32
278 		if (m->m_next) {
279 			if (m->m_flags & M_LOOP)
280 			/*XXX*/	IP6_STATINC(IP6_STAT_M2M + lo0ifp->if_index);
281 			else if (rcvif->if_index < M2MMAX)
282 				IP6_STATINC(IP6_STAT_M2M + rcvif->if_index);
283 			else
284 				IP6_STATINC(IP6_STAT_M2M);
285 		} else
286 			IP6_STATINC(IP6_STAT_M1);
287 #undef M2MMAX
288 	}
289 
290 	in6_ifstat_inc(rcvif, ifs6_in_receive);
291 	IP6_STATINC(IP6_STAT_TOTAL);
292 
293 	/*
294 	 * If the IPv6 header is not aligned, slurp it up into a new
295 	 * mbuf with space for link headers, in the event we forward
296 	 * it.  Otherwise, if it is aligned, make sure the entire base
297 	 * IPv6 header is in the first mbuf of the chain.
298 	 */
299 	if (IP6_HDR_ALIGNED_P(mtod(m, void *)) == 0) {
300 		if ((m = m_copyup(m, sizeof(struct ip6_hdr),
301 		    (max_linkhdr + 3) & ~3)) == NULL) {
302 			/* XXXJRT new stat, please */
303 			IP6_STATINC(IP6_STAT_TOOSMALL);
304 			in6_ifstat_inc(rcvif, ifs6_in_hdrerr);
305 			return;
306 		}
307 	} else if (__predict_false(m->m_len < sizeof(struct ip6_hdr))) {
308 		if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
309 			IP6_STATINC(IP6_STAT_TOOSMALL);
310 			in6_ifstat_inc(rcvif, ifs6_in_hdrerr);
311 			return;
312 		}
313 	}
314 
315 	ip6 = mtod(m, struct ip6_hdr *);
316 
317 	if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
318 		IP6_STATINC(IP6_STAT_BADVERS);
319 		in6_ifstat_inc(rcvif, ifs6_in_hdrerr);
320 		goto bad;
321 	}
322 
323 	/*
324 	 * Check against address spoofing/corruption.
325 	 */
326 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
327 	    IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
328 		/*
329 		 * XXX: "badscope" is not very suitable for a multicast source.
330 		 */
331 		IP6_STATINC(IP6_STAT_BADSCOPE);
332 		in6_ifstat_inc(rcvif, ifs6_in_addrerr);
333 		goto bad;
334 	}
335 
336 	/*
337 	 * The following check is not documented in specs.  A malicious
338 	 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
339 	 * and bypass security checks (act as if it was from 127.0.0.1 by using
340 	 * IPv6 src ::ffff:127.0.0.1).  Be cautious.
341 	 *
342 	 * This check chokes if we are in an SIIT cloud.  As none of BSDs
343 	 * support IPv4-less kernel compilation, we cannot support SIIT
344 	 * environment at all.  So, it makes more sense for us to reject any
345 	 * malicious packets for non-SIIT environment, than try to do a
346 	 * partial support for SIIT environment.
347 	 */
348 	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
349 	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
350 		IP6_STATINC(IP6_STAT_BADSCOPE);
351 		in6_ifstat_inc(rcvif, ifs6_in_addrerr);
352 		goto bad;
353 	}
354 
355 #if 0
356 	/*
357 	 * Reject packets with IPv4 compatible addresses (auto tunnel).
358 	 *
359 	 * The code forbids auto tunnel relay case in RFC1933 (the check is
360 	 * stronger than RFC1933).  We may want to re-enable it if mech-xx
361 	 * is revised to forbid relaying case.
362 	 */
363 	if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
364 	    IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
365 		IP6_STATINC(IP6_STAT_BADSCOPE);
366 		in6_ifstat_inc(rcvif, ifs6_in_addrerr);
367 		goto bad;
368 	}
369 #endif
370 
371 	/*
372 	 * Assume that we can create a fast-forward IP flow entry
373 	 * based on this packet.
374 	 */
375 	m->m_flags |= M_CANFASTFWD;
376 
377 	/*
378 	 * Run through list of hooks for input packets.  If there are any
379 	 * filters which require that additional packets in the flow are
380 	 * not fast-forwarded, they must clear the M_CANFASTFWD flag.
381 	 * Note that filters must _never_ set this flag, as another filter
382 	 * in the list may have previously cleared it.
383 	 */
384 	/*
385 	 * let ipfilter look at packet on the wire,
386 	 * not the decapsulated packet.
387 	 */
388 #if defined(IPSEC)
389 	if (!ipsec_used || !ipsec_indone(m))
390 #else
391 	if (1)
392 #endif
393 	{
394 		struct in6_addr odst;
395 
396 		odst = ip6->ip6_dst;
397 		if (pfil_run_hooks(inet6_pfil_hook, &m, rcvif, PFIL_IN) != 0)
398 			return;
399 		if (m == NULL)
400 			return;
401 		ip6 = mtod(m, struct ip6_hdr *);
402 		srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
403 	}
404 
405 	IP6_STATINC(IP6_STAT_NXTHIST + ip6->ip6_nxt);
406 
407 #ifdef ALTQ
408 	if (altq_input != NULL) {
409 		SOFTNET_LOCK();
410 		if ((*altq_input)(m, AF_INET6) == 0) {
411 			SOFTNET_UNLOCK();
412 			/* packet is dropped by traffic conditioner */
413 			return;
414 		}
415 		SOFTNET_UNLOCK();
416 	}
417 #endif
418 
419 	/*
420 	 * Disambiguate address scope zones (if there is ambiguity).
421 	 * We first make sure that the original source or destination address
422 	 * is not in our internal form for scoped addresses.  Such addresses
423 	 * are not necessarily invalid spec-wise, but we cannot accept them due
424 	 * to the usage conflict.
425 	 * in6_setscope() then also checks and rejects the cases where src or
426 	 * dst are the loopback address and the receiving interface
427 	 * is not loopback.
428 	 */
429 	if (__predict_false(
430 	    m_makewritable(&m, 0, sizeof(struct ip6_hdr), M_DONTWAIT)))
431 		goto bad;
432 	ip6 = mtod(m, struct ip6_hdr *);
433 	if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) {
434 		IP6_STATINC(IP6_STAT_BADSCOPE);	/* XXX */
435 		goto bad;
436 	}
437 	if (in6_setscope(&ip6->ip6_src, rcvif, NULL) ||
438 	    in6_setscope(&ip6->ip6_dst, rcvif, NULL)) {
439 		IP6_STATINC(IP6_STAT_BADSCOPE);
440 		goto bad;
441 	}
442 
443 	ro = percpu_getref(ip6_forward_rt_percpu);
444 
445 	/*
446 	 * Multicast check
447 	 */
448 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
449 		bool ingroup;
450 
451 		in6_ifstat_inc(rcvif, ifs6_in_mcast);
452 		/*
453 		 * See if we belong to the destination multicast group on the
454 		 * arrival interface.
455 		 */
456 		ingroup = in6_multi_group(&ip6->ip6_dst, rcvif);
457 		if (ingroup) {
458 			ours = 1;
459 		} else if (!ip6_mrouter) {
460 			uint64_t *ip6s = IP6_STAT_GETREF();
461 			ip6s[IP6_STAT_NOTMEMBER]++;
462 			ip6s[IP6_STAT_CANTFORWARD]++;
463 			IP6_STAT_PUTREF();
464 			in6_ifstat_inc(rcvif, ifs6_in_discard);
465 			goto bad_unref;
466 		}
467 		deliverifp = rcvif;
468 		goto hbhcheck;
469 	}
470 
471 	sockaddr_in6_init(&u.dst6, &ip6->ip6_dst, 0, 0, 0);
472 
473 	/*
474 	 * Unicast check
475 	 */
476 	rt = rtcache_lookup2(ro, &u.dst, 1, &hit);
477 	if (hit)
478 		IP6_STATINC(IP6_STAT_FORWARD_CACHEHIT);
479 	else
480 		IP6_STATINC(IP6_STAT_FORWARD_CACHEMISS);
481 
482 	/*
483 	 * Accept the packet if the forwarding interface to the destination
484 	 * (according to the routing table) is the loopback interface,
485 	 * unless the associated route has a gateway.
486 	 *
487 	 * We don't explicitly match ip6_dst against an interface here. It
488 	 * is already done in rtcache_lookup2: rt->rt_ifp->if_type will be
489 	 * IFT_LOOP if the packet is for us.
490 	 *
491 	 * Note that this approach causes to accept a packet if there is a
492 	 * route to the loopback interface for the destination of the packet.
493 	 * But we think it's even useful in some situations, e.g. when using
494 	 * a special daemon which wants to intercept the packet.
495 	 */
496 	if (rt != NULL &&
497 	    (rt->rt_flags & (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
498 	    rt->rt_ifp->if_type == IFT_LOOP) {
499 		struct in6_ifaddr *ia6 = (struct in6_ifaddr *)rt->rt_ifa;
500 		int addrok;
501 
502 		if (ia6->ia6_flags & IN6_IFF_ANYCAST)
503 			m->m_flags |= M_ANYCAST6;
504 		/*
505 		 * packets to a tentative, duplicated, or somehow invalid
506 		 * address must not be accepted.
507 		 */
508 		if (ia6->ia6_flags & IN6_IFF_NOTREADY)
509 			addrok = 0;
510 		else if (ia6->ia6_flags & IN6_IFF_DETACHED &&
511 		    !IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src))
512 		{
513 			/* Allow internal traffic to DETACHED addresses */
514 			struct sockaddr_in6 sin6;
515 			int s;
516 
517 			memset(&sin6, 0, sizeof(sin6));
518 			sin6.sin6_family = AF_INET6;
519 			sin6.sin6_len = sizeof(sin6);
520 			sin6.sin6_addr = ip6->ip6_src;
521 			s = pserialize_read_enter();
522 			addrok = (ifa_ifwithaddr(sin6tosa(&sin6)) != NULL);
523 			pserialize_read_exit(s);
524 		} else
525 			addrok = 1;
526 		if (addrok) {
527 			/* this address is ready */
528 			ours = 1;
529 			deliverifp = ia6->ia_ifp;	/* correct? */
530 			goto hbhcheck;
531 		} else {
532 			/* address is not ready, so discard the packet. */
533 			char ip6bufs[INET6_ADDRSTRLEN];
534 			char ip6bufd[INET6_ADDRSTRLEN];
535 			nd6log(LOG_INFO, "packet to an unready address %s->%s\n",
536 			    IN6_PRINT(ip6bufs, &ip6->ip6_src),
537 			    IN6_PRINT(ip6bufd, &ip6->ip6_dst));
538 
539 			goto bad_unref;
540 		}
541 	}
542 
543 	/*
544 	 * FAITH (Firewall Aided Internet Translator)
545 	 */
546 #if defined(NFAITH) && 0 < NFAITH
547 	if (ip6_keepfaith) {
548 		if (rt != NULL && rt->rt_ifp != NULL &&
549 		    rt->rt_ifp->if_type == IFT_FAITH) {
550 			/* XXX do we need more sanity checks? */
551 			ours = 1;
552 			deliverifp = rt->rt_ifp; /* faith */
553 			goto hbhcheck;
554 		}
555 	}
556 #endif
557 
558 	/*
559 	 * Now there is no reason to process the packet if it's not our own
560 	 * and we're not a router.
561 	 */
562 	if (!ip6_forwarding) {
563 		IP6_STATINC(IP6_STAT_CANTFORWARD);
564 		in6_ifstat_inc(rcvif, ifs6_in_discard);
565 		goto bad_unref;
566 	}
567 
568 hbhcheck:
569 	/*
570 	 * Record address information into m_tag, if we don't have one yet.
571 	 * Note that we are unable to record it, if the address is not listed
572 	 * as our interface address (e.g. multicast addresses, addresses
573 	 * within FAITH prefixes and such).
574 	 */
575 	if (deliverifp && ip6_getdstifaddr(m) == NULL) {
576 		struct in6_ifaddr *ia6;
577 		int s = pserialize_read_enter();
578 
579 		ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
580 		/* Depends on ip6_setdstifaddr never sleep */
581 		if (ia6 != NULL && ip6_setdstifaddr(m, ia6) == NULL) {
582 			/*
583 			 * XXX maybe we should drop the packet here,
584 			 * as we could not provide enough information
585 			 * to the upper layers.
586 			 */
587 		}
588 		pserialize_read_exit(s);
589 	}
590 
591 	/*
592 	 * Process Hop-by-Hop options header if it's contained.
593 	 * m may be modified in ip6_hopopts_input().
594 	 * If a JumboPayload option is included, plen will also be modified.
595 	 */
596 	plen = (u_int32_t)ntohs(ip6->ip6_plen);
597 	if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
598 		struct ip6_hbh *hbh;
599 
600 		if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) {
601 			/* m already freed */
602 			in6_ifstat_inc(rcvif, ifs6_in_discard);
603 			rtcache_unref(rt, ro);
604 			percpu_putref(ip6_forward_rt_percpu);
605 			return;
606 		}
607 
608 		/* adjust pointer */
609 		ip6 = mtod(m, struct ip6_hdr *);
610 
611 		/*
612 		 * if the payload length field is 0 and the next header field
613 		 * indicates Hop-by-Hop Options header, then a Jumbo Payload
614 		 * option MUST be included.
615 		 */
616 		if (ip6->ip6_plen == 0 && plen == 0) {
617 			/*
618 			 * Note that if a valid jumbo payload option is
619 			 * contained, ip6_hopopts_input() must set a valid
620 			 * (non-zero) payload length to the variable plen.
621 			 */
622 			IP6_STATINC(IP6_STAT_BADOPTIONS);
623 			in6_ifstat_inc(rcvif, ifs6_in_discard);
624 			in6_ifstat_inc(rcvif, ifs6_in_hdrerr);
625 			icmp6_error(m, ICMP6_PARAM_PROB,
626 				    ICMP6_PARAMPROB_HEADER,
627 				    (char *)&ip6->ip6_plen - (char *)ip6);
628 			rtcache_unref(rt, ro);
629 			percpu_putref(ip6_forward_rt_percpu);
630 			return;
631 		}
632 		IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
633 			sizeof(struct ip6_hbh));
634 		if (hbh == NULL) {
635 			IP6_STATINC(IP6_STAT_TOOSHORT);
636 			rtcache_unref(rt, ro);
637 			percpu_putref(ip6_forward_rt_percpu);
638 			return;
639 		}
640 		KASSERT(IP6_HDR_ALIGNED_P(hbh));
641 		nxt = hbh->ip6h_nxt;
642 
643 		/*
644 		 * accept the packet if a router alert option is included
645 		 * and we act as an IPv6 router.
646 		 */
647 		if (rtalert != ~0 && ip6_forwarding)
648 			ours = 1;
649 	} else
650 		nxt = ip6->ip6_nxt;
651 
652 	/*
653 	 * Check that the amount of data in the buffers is at least much as
654 	 * the IPv6 header would have us expect. Trim mbufs if longer than we
655 	 * expect. Drop packet if shorter than we expect.
656 	 */
657 	if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
658 		IP6_STATINC(IP6_STAT_TOOSHORT);
659 		in6_ifstat_inc(rcvif, ifs6_in_truncated);
660 		goto bad_unref;
661 	}
662 	if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
663 		if (m->m_len == m->m_pkthdr.len) {
664 			m->m_len = sizeof(struct ip6_hdr) + plen;
665 			m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
666 		} else
667 			m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
668 	}
669 
670 	/*
671 	 * Forward if desirable.
672 	 */
673 	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
674 		/*
675 		 * If we are acting as a multicast router, all
676 		 * incoming multicast packets are passed to the
677 		 * kernel-level multicast forwarding function.
678 		 * The packet is returned (relatively) intact; if
679 		 * ip6_mforward() returns a non-zero value, the packet
680 		 * must be discarded, else it may be accepted below.
681 		 */
682 		if (ip6_mrouter != NULL) {
683 			int error;
684 
685 			SOFTNET_LOCK();
686 			error = ip6_mforward(ip6, rcvif, m);
687 			SOFTNET_UNLOCK();
688 
689 			if (error != 0) {
690 				rtcache_unref(rt, ro);
691 				percpu_putref(ip6_forward_rt_percpu);
692 				IP6_STATINC(IP6_STAT_CANTFORWARD);
693 				goto bad;
694 			}
695 		}
696 		if (!ours)
697 			goto bad_unref;
698 	} else if (!ours) {
699 		rtcache_unref(rt, ro);
700 		percpu_putref(ip6_forward_rt_percpu);
701 		ip6_forward(m, srcrt);
702 		return;
703 	}
704 
705 	ip6 = mtod(m, struct ip6_hdr *);
706 
707 	/*
708 	 * Malicious party may be able to use IPv4 mapped addr to confuse
709 	 * tcp/udp stack and bypass security checks (act as if it was from
710 	 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1).  Be cautious.
711 	 *
712 	 * For SIIT end node behavior, you may want to disable the check.
713 	 * However, you will  become vulnerable to attacks using IPv4 mapped
714 	 * source.
715 	 */
716 	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
717 	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
718 		IP6_STATINC(IP6_STAT_BADSCOPE);
719 		in6_ifstat_inc(rcvif, ifs6_in_addrerr);
720 		goto bad_unref;
721 	}
722 
723 #ifdef IFA_STATS
724 	if (deliverifp != NULL) {
725 		struct in6_ifaddr *ia6;
726 		int s = pserialize_read_enter();
727 		ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
728 		if (ia6)
729 			ia6->ia_ifa.ifa_data.ifad_inbytes += m->m_pkthdr.len;
730 		pserialize_read_exit(s);
731 	}
732 #endif
733 	IP6_STATINC(IP6_STAT_DELIVERED);
734 	in6_ifstat_inc(deliverifp, ifs6_in_deliver);
735 	nest = 0;
736 
737 	if (rt != NULL) {
738 		rtcache_unref(rt, ro);
739 		rt = NULL;
740 	}
741 	percpu_putref(ip6_forward_rt_percpu);
742 
743 	rh_present = 0;
744 	frg_present = 0;
745 	while (nxt != IPPROTO_DONE) {
746 		if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
747 			IP6_STATINC(IP6_STAT_TOOMANYHDR);
748 			in6_ifstat_inc(rcvif, ifs6_in_hdrerr);
749 			goto bad;
750 		}
751 
752 		/*
753 		 * protection against faulty packet - there should be
754 		 * more sanity checks in header chain processing.
755 		 */
756 		if (m->m_pkthdr.len < off) {
757 			IP6_STATINC(IP6_STAT_TOOSHORT);
758 			in6_ifstat_inc(rcvif, ifs6_in_truncated);
759 			goto bad;
760 		}
761 
762 		if (nxt == IPPROTO_ROUTING) {
763 			if (rh_present++) {
764 				in6_ifstat_inc(rcvif, ifs6_in_hdrerr);
765 				IP6_STATINC(IP6_STAT_BADOPTIONS);
766 				goto bad;
767 			}
768 		} else if (nxt == IPPROTO_FRAGMENT) {
769 			if (frg_present++) {
770 				in6_ifstat_inc(rcvif, ifs6_in_hdrerr);
771 				IP6_STATINC(IP6_STAT_BADOPTIONS);
772 				goto bad;
773 			}
774 		}
775 
776 #ifdef IPSEC
777 		if (ipsec_used) {
778 			/*
779 			 * Enforce IPsec policy checking if we are seeing last
780 			 * header. Note that we do not visit this with
781 			 * protocols with pcb layer code - like udp/tcp/raw ip.
782 			 */
783 			if ((inet6sw[ip_protox[nxt]].pr_flags
784 			    & PR_LASTHDR) != 0) {
785 				int error;
786 
787 				error = ipsec6_input(m);
788 				if (error)
789 					goto bad;
790 			}
791 		}
792 #endif
793 
794 		nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
795 	}
796 	return;
797 
798 bad_unref:
799 	rtcache_unref(rt, ro);
800 	percpu_putref(ip6_forward_rt_percpu);
801 bad:
802 	m_freem(m);
803 	return;
804 }
805 
806 /*
807  * set/grab in6_ifaddr correspond to IPv6 destination address.
808  */
809 static struct m_tag *
810 ip6_setdstifaddr(struct mbuf *m, const struct in6_ifaddr *ia)
811 {
812 	struct m_tag *mtag;
813 	struct ip6aux *ip6a;
814 
815 	mtag = ip6_addaux(m);
816 	if (mtag == NULL)
817 		return NULL;
818 
819 	ip6a = (struct ip6aux *)(mtag + 1);
820 	if (in6_setscope(&ip6a->ip6a_src, ia->ia_ifp, &ip6a->ip6a_scope_id)) {
821 		IP6_STATINC(IP6_STAT_BADSCOPE);
822 		return NULL;
823 	}
824 
825 	ip6a->ip6a_src = ia->ia_addr.sin6_addr;
826 	ip6a->ip6a_flags = ia->ia6_flags;
827 	return mtag;
828 }
829 
830 const struct ip6aux *
831 ip6_getdstifaddr(struct mbuf *m)
832 {
833 	struct m_tag *mtag;
834 
835 	mtag = ip6_findaux(m);
836 	if (mtag != NULL)
837 		return (struct ip6aux *)(mtag + 1);
838 	else
839 		return NULL;
840 }
841 
842 /*
843  * Hop-by-Hop options header processing. If a valid jumbo payload option is
844  * included, the real payload length will be stored in plenp.
845  *
846  * rtalertp - XXX: should be stored more smart way
847  */
848 int
849 ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp,
850 	struct mbuf **mp, int *offp)
851 {
852 	struct mbuf *m = *mp;
853 	int off = *offp, hbhlen;
854 	struct ip6_hbh *hbh;
855 
856 	/* validation of the length of the header */
857 	IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
858 	    sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
859 	if (hbh == NULL) {
860 		IP6_STATINC(IP6_STAT_TOOSHORT);
861 		return -1;
862 	}
863 	hbhlen = (hbh->ip6h_len + 1) << 3;
864 	IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
865 	    hbhlen);
866 	if (hbh == NULL) {
867 		IP6_STATINC(IP6_STAT_TOOSHORT);
868 		return -1;
869 	}
870 	KASSERT(IP6_HDR_ALIGNED_P(hbh));
871 	off += hbhlen;
872 	hbhlen -= sizeof(struct ip6_hbh);
873 
874 	if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
875 	    hbhlen, rtalertp, plenp) < 0)
876 		return -1;
877 
878 	*offp = off;
879 	*mp = m;
880 	return 0;
881 }
882 
883 /*
884  * Search header for all Hop-by-hop options and process each option.
885  * This function is separate from ip6_hopopts_input() in order to
886  * handle a case where the sending node itself process its hop-by-hop
887  * options header. In such a case, the function is called from ip6_output().
888  *
889  * The function assumes that hbh header is located right after the IPv6 header
890  * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
891  * opthead + hbhlen is located in continuous memory region.
892  */
893 static int
894 ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen,
895 	u_int32_t *rtalertp, u_int32_t *plenp)
896 {
897 	struct ip6_hdr *ip6;
898 	int optlen = 0;
899 	u_int8_t *opt = opthead;
900 	u_int16_t rtalert_val;
901 	u_int32_t jumboplen;
902 	const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
903 
904 	for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
905 		switch (*opt) {
906 		case IP6OPT_PAD1:
907 			optlen = 1;
908 			break;
909 		case IP6OPT_PADN:
910 			if (hbhlen < IP6OPT_MINLEN) {
911 				IP6_STATINC(IP6_STAT_TOOSMALL);
912 				goto bad;
913 			}
914 			optlen = *(opt + 1) + 2;
915 			break;
916 		case IP6OPT_RTALERT:
917 			/* XXX may need check for alignment */
918 			if (hbhlen < IP6OPT_RTALERT_LEN) {
919 				IP6_STATINC(IP6_STAT_TOOSMALL);
920 				goto bad;
921 			}
922 			if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
923 				/* XXX stat */
924 				icmp6_error(m, ICMP6_PARAM_PROB,
925 				    ICMP6_PARAMPROB_HEADER,
926 				    erroff + opt + 1 - opthead);
927 				return (-1);
928 			}
929 			optlen = IP6OPT_RTALERT_LEN;
930 			memcpy((void *)&rtalert_val, (void *)(opt + 2), 2);
931 			*rtalertp = ntohs(rtalert_val);
932 			break;
933 		case IP6OPT_JUMBO:
934 			/* XXX may need check for alignment */
935 			if (hbhlen < IP6OPT_JUMBO_LEN) {
936 				IP6_STATINC(IP6_STAT_TOOSMALL);
937 				goto bad;
938 			}
939 			if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
940 				/* XXX stat */
941 				icmp6_error(m, ICMP6_PARAM_PROB,
942 				    ICMP6_PARAMPROB_HEADER,
943 				    erroff + opt + 1 - opthead);
944 				return (-1);
945 			}
946 			optlen = IP6OPT_JUMBO_LEN;
947 
948 			/*
949 			 * IPv6 packets that have non 0 payload length
950 			 * must not contain a jumbo payload option.
951 			 */
952 			ip6 = mtod(m, struct ip6_hdr *);
953 			if (ip6->ip6_plen) {
954 				IP6_STATINC(IP6_STAT_BADOPTIONS);
955 				icmp6_error(m, ICMP6_PARAM_PROB,
956 				    ICMP6_PARAMPROB_HEADER,
957 				    erroff + opt - opthead);
958 				return (-1);
959 			}
960 
961 			/*
962 			 * We may see jumbolen in unaligned location, so
963 			 * we'd need to perform memcpy().
964 			 */
965 			memcpy(&jumboplen, opt + 2, sizeof(jumboplen));
966 			jumboplen = (u_int32_t)htonl(jumboplen);
967 
968 #if 1
969 			/*
970 			 * if there are multiple jumbo payload options,
971 			 * *plenp will be non-zero and the packet will be
972 			 * rejected.
973 			 * the behavior may need some debate in ipngwg -
974 			 * multiple options does not make sense, however,
975 			 * there's no explicit mention in specification.
976 			 */
977 			if (*plenp != 0) {
978 				IP6_STATINC(IP6_STAT_BADOPTIONS);
979 				icmp6_error(m, ICMP6_PARAM_PROB,
980 				    ICMP6_PARAMPROB_HEADER,
981 				    erroff + opt + 2 - opthead);
982 				return (-1);
983 			}
984 #endif
985 
986 			/*
987 			 * jumbo payload length must be larger than 65535.
988 			 */
989 			if (jumboplen <= IPV6_MAXPACKET) {
990 				IP6_STATINC(IP6_STAT_BADOPTIONS);
991 				icmp6_error(m, ICMP6_PARAM_PROB,
992 				    ICMP6_PARAMPROB_HEADER,
993 				    erroff + opt + 2 - opthead);
994 				return (-1);
995 			}
996 			*plenp = jumboplen;
997 
998 			break;
999 		default:		/* unknown option */
1000 			if (hbhlen < IP6OPT_MINLEN) {
1001 				IP6_STATINC(IP6_STAT_TOOSMALL);
1002 				goto bad;
1003 			}
1004 			optlen = ip6_unknown_opt(opt, m,
1005 			    erroff + opt - opthead);
1006 			if (optlen == -1)
1007 				return (-1);
1008 			optlen += 2;
1009 			break;
1010 		}
1011 	}
1012 
1013 	return (0);
1014 
1015   bad:
1016 	m_freem(m);
1017 	return (-1);
1018 }
1019 
1020 /*
1021  * Unknown option processing.
1022  * The third argument `off' is the offset from the IPv6 header to the option,
1023  * which is necessary if the IPv6 header the and option header and IPv6 header
1024  * is not continuous in order to return an ICMPv6 error.
1025  */
1026 int
1027 ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off)
1028 {
1029 	struct ip6_hdr *ip6;
1030 
1031 	switch (IP6OPT_TYPE(*optp)) {
1032 	case IP6OPT_TYPE_SKIP: /* ignore the option */
1033 		return ((int)*(optp + 1));
1034 	case IP6OPT_TYPE_DISCARD:	/* silently discard */
1035 		m_freem(m);
1036 		return (-1);
1037 	case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
1038 		IP6_STATINC(IP6_STAT_BADOPTIONS);
1039 		icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
1040 		return (-1);
1041 	case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
1042 		IP6_STATINC(IP6_STAT_BADOPTIONS);
1043 		ip6 = mtod(m, struct ip6_hdr *);
1044 		if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
1045 		    (m->m_flags & (M_BCAST|M_MCAST)))
1046 			m_freem(m);
1047 		else
1048 			icmp6_error(m, ICMP6_PARAM_PROB,
1049 				    ICMP6_PARAMPROB_OPTION, off);
1050 		return (-1);
1051 	}
1052 
1053 	m_freem(m);		/* XXX: NOTREACHED */
1054 	return (-1);
1055 }
1056 
1057 /*
1058  * Create the "control" list for this pcb.
1059  *
1060  * The routine will be called from upper layer handlers like tcp6_input().
1061  * Thus the routine assumes that the caller (tcp6_input) have already
1062  * called IP6_EXTHDR_CHECK() and all the extension headers are located in the
1063  * very first mbuf on the mbuf chain.
1064  * We may want to add some infinite loop prevention or sanity checks for safety.
1065  * (This applies only when you are using KAME mbuf chain restriction, i.e.
1066  * you are using IP6_EXTHDR_CHECK() not m_pulldown())
1067  */
1068 void
1069 ip6_savecontrol(struct in6pcb *in6p, struct mbuf **mp,
1070 	struct ip6_hdr *ip6, struct mbuf *m)
1071 {
1072 	struct socket *so = in6p->in6p_socket;
1073 #ifdef RFC2292
1074 #define IS2292(x, y)	((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y))
1075 #else
1076 #define IS2292(x, y)	(y)
1077 #endif
1078 
1079 	if (SOOPT_TIMESTAMP(so->so_options))
1080 		mp = sbsavetimestamp(so->so_options, m, mp);
1081 
1082 	/* some OSes call this logic with IPv4 packet, for SO_TIMESTAMP */
1083 	if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION)
1084 		return;
1085 
1086 	/* RFC 2292 sec. 5 */
1087 	if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) {
1088 		struct in6_pktinfo pi6;
1089 
1090 		memcpy(&pi6.ipi6_addr, &ip6->ip6_dst, sizeof(struct in6_addr));
1091 		in6_clearscope(&pi6.ipi6_addr);	/* XXX */
1092 		pi6.ipi6_ifindex = m->m_pkthdr.rcvif_index;
1093 		*mp = sbcreatecontrol(&pi6, sizeof(pi6),
1094 		    IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6);
1095 		if (*mp)
1096 			mp = &(*mp)->m_next;
1097 	}
1098 
1099 	if (in6p->in6p_flags & IN6P_HOPLIMIT) {
1100 		int hlim = ip6->ip6_hlim & 0xff;
1101 
1102 		*mp = sbcreatecontrol(&hlim, sizeof(hlim),
1103 		    IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6);
1104 		if (*mp)
1105 			mp = &(*mp)->m_next;
1106 	}
1107 
1108 	if ((in6p->in6p_flags & IN6P_TCLASS) != 0) {
1109 		u_int32_t flowinfo;
1110 		int tclass;
1111 
1112 		flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
1113 		flowinfo >>= 20;
1114 
1115 		tclass = flowinfo & 0xff;
1116 		*mp = sbcreatecontrol(&tclass, sizeof(tclass),
1117 		    IPV6_TCLASS, IPPROTO_IPV6);
1118 
1119 		if (*mp)
1120 			mp = &(*mp)->m_next;
1121 	}
1122 
1123 	/*
1124 	 * IPV6_HOPOPTS socket option.  Recall that we required super-user
1125 	 * privilege for the option (see ip6_ctloutput), but it might be too
1126 	 * strict, since there might be some hop-by-hop options which can be
1127 	 * returned to normal user.
1128 	 * See also RFC3542 section 8 (or RFC2292 section 6).
1129 	 */
1130 	if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) {
1131 		/*
1132 		 * Check if a hop-by-hop options header is contatined in the
1133 		 * received packet, and if so, store the options as ancillary
1134 		 * data. Note that a hop-by-hop options header must be
1135 		 * just after the IPv6 header, which fact is assured through
1136 		 * the IPv6 input processing.
1137 		 */
1138 		struct ip6_hdr *xip6 = mtod(m, struct ip6_hdr *);
1139 		if (xip6->ip6_nxt == IPPROTO_HOPOPTS) {
1140 			struct ip6_hbh *hbh;
1141 			int hbhlen;
1142 			struct mbuf *ext;
1143 
1144 			ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
1145 			    xip6->ip6_nxt);
1146 			if (ext == NULL) {
1147 				IP6_STATINC(IP6_STAT_TOOSHORT);
1148 				return;
1149 			}
1150 			hbh = mtod(ext, struct ip6_hbh *);
1151 			hbhlen = (hbh->ip6h_len + 1) << 3;
1152 			if (hbhlen != ext->m_len) {
1153 				m_freem(ext);
1154 				IP6_STATINC(IP6_STAT_TOOSHORT);
1155 				return;
1156 			}
1157 
1158 			/*
1159 			 * XXX: We copy whole the header even if a jumbo
1160 			 * payload option is included, which option is to
1161 			 * be removed before returning in the RFC 2292.
1162 			 * Note: this constraint is removed in RFC3542.
1163 			 */
1164 			*mp = sbcreatecontrol(hbh, hbhlen,
1165 			    IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS),
1166 			    IPPROTO_IPV6);
1167 			if (*mp)
1168 				mp = &(*mp)->m_next;
1169 			m_freem(ext);
1170 		}
1171 	}
1172 
1173 	/* IPV6_DSTOPTS and IPV6_RTHDR socket options */
1174 	if (in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDR)) {
1175 		struct ip6_hdr *xip6 = mtod(m, struct ip6_hdr *);
1176 		int nxt = xip6->ip6_nxt, off = sizeof(struct ip6_hdr);
1177 
1178 		/*
1179 		 * Search for destination options headers or routing
1180 		 * header(s) through the header chain, and stores each
1181 		 * header as ancillary data.
1182 		 * Note that the order of the headers remains in
1183 		 * the chain of ancillary data.
1184 		 */
1185 		for (;;) {	/* is explicit loop prevention necessary? */
1186 			struct ip6_ext *ip6e = NULL;
1187 			int elen;
1188 			struct mbuf *ext = NULL;
1189 
1190 			/*
1191 			 * if it is not an extension header, don't try to
1192 			 * pull it from the chain.
1193 			 */
1194 			switch (nxt) {
1195 			case IPPROTO_DSTOPTS:
1196 			case IPPROTO_ROUTING:
1197 			case IPPROTO_HOPOPTS:
1198 			case IPPROTO_AH: /* is it possible? */
1199 				break;
1200 			default:
1201 				goto loopend;
1202 			}
1203 
1204 			ext = ip6_pullexthdr(m, off, nxt);
1205 			if (ext == NULL) {
1206 				IP6_STATINC(IP6_STAT_TOOSHORT);
1207 				return;
1208 			}
1209 			ip6e = mtod(ext, struct ip6_ext *);
1210 			if (nxt == IPPROTO_AH)
1211 				elen = (ip6e->ip6e_len + 2) << 2;
1212 			else
1213 				elen = (ip6e->ip6e_len + 1) << 3;
1214 			if (elen != ext->m_len) {
1215 				m_freem(ext);
1216 				IP6_STATINC(IP6_STAT_TOOSHORT);
1217 				return;
1218 			}
1219 			KASSERT(IP6_HDR_ALIGNED_P(ip6e));
1220 
1221 			switch (nxt) {
1222 			case IPPROTO_DSTOPTS:
1223 				if (!(in6p->in6p_flags & IN6P_DSTOPTS))
1224 					break;
1225 
1226 				*mp = sbcreatecontrol(ip6e, elen,
1227 				    IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS),
1228 				    IPPROTO_IPV6);
1229 				if (*mp)
1230 					mp = &(*mp)->m_next;
1231 				break;
1232 
1233 			case IPPROTO_ROUTING:
1234 				if (!(in6p->in6p_flags & IN6P_RTHDR))
1235 					break;
1236 
1237 				*mp = sbcreatecontrol(ip6e, elen,
1238 				    IS2292(IPV6_2292RTHDR, IPV6_RTHDR),
1239 				    IPPROTO_IPV6);
1240 				if (*mp)
1241 					mp = &(*mp)->m_next;
1242 				break;
1243 
1244 			case IPPROTO_HOPOPTS:
1245 			case IPPROTO_AH: /* is it possible? */
1246 				break;
1247 
1248 			default:
1249 				/*
1250 			 	 * other cases have been filtered in the above.
1251 				 * none will visit this case.  here we supply
1252 				 * the code just in case (nxt overwritten or
1253 				 * other cases).
1254 				 */
1255 				m_freem(ext);
1256 				goto loopend;
1257 
1258 			}
1259 
1260 			/* proceed with the next header. */
1261 			off += elen;
1262 			nxt = ip6e->ip6e_nxt;
1263 			ip6e = NULL;
1264 			m_freem(ext);
1265 			ext = NULL;
1266 		}
1267 	  loopend:
1268 	  	;
1269 	}
1270 }
1271 #undef IS2292
1272 
1273 
1274 void
1275 ip6_notify_pmtu(struct in6pcb *in6p, const struct sockaddr_in6 *dst,
1276     uint32_t *mtu)
1277 {
1278 	struct socket *so;
1279 	struct mbuf *m_mtu;
1280 	struct ip6_mtuinfo mtuctl;
1281 
1282 	so = in6p->in6p_socket;
1283 
1284 	if (mtu == NULL)
1285 		return;
1286 
1287 	KASSERT(so != NULL);
1288 
1289 	memset(&mtuctl, 0, sizeof(mtuctl));	/* zero-clear for safety */
1290 	mtuctl.ip6m_mtu = *mtu;
1291 	mtuctl.ip6m_addr = *dst;
1292 	if (sa6_recoverscope(&mtuctl.ip6m_addr))
1293 		return;
1294 
1295 	if ((m_mtu = sbcreatecontrol(&mtuctl, sizeof(mtuctl),
1296 	    IPV6_PATHMTU, IPPROTO_IPV6)) == NULL)
1297 		return;
1298 
1299 	if (sbappendaddr(&so->so_rcv, (const struct sockaddr *)dst, NULL, m_mtu)
1300 	    == 0) {
1301 		soroverflow(so);
1302 		m_freem(m_mtu);
1303 	} else
1304 		sorwakeup(so);
1305 
1306 	return;
1307 }
1308 
1309 /*
1310  * pull single extension header from mbuf chain.  returns single mbuf that
1311  * contains the result, or NULL on error.
1312  */
1313 static struct mbuf *
1314 ip6_pullexthdr(struct mbuf *m, size_t off, int nxt)
1315 {
1316 	struct ip6_ext ip6e;
1317 	size_t elen;
1318 	struct mbuf *n;
1319 
1320 #ifdef DIAGNOSTIC
1321 	switch (nxt) {
1322 	case IPPROTO_DSTOPTS:
1323 	case IPPROTO_ROUTING:
1324 	case IPPROTO_HOPOPTS:
1325 	case IPPROTO_AH: /* is it possible? */
1326 		break;
1327 	default:
1328 		printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
1329 	}
1330 #endif
1331 
1332 	m_copydata(m, off, sizeof(ip6e), (void *)&ip6e);
1333 	if (nxt == IPPROTO_AH)
1334 		elen = (ip6e.ip6e_len + 2) << 2;
1335 	else
1336 		elen = (ip6e.ip6e_len + 1) << 3;
1337 
1338 	MGET(n, M_DONTWAIT, MT_DATA);
1339 	if (n && elen >= MLEN) {
1340 		MCLGET(n, M_DONTWAIT);
1341 		if ((n->m_flags & M_EXT) == 0) {
1342 			m_free(n);
1343 			n = NULL;
1344 		}
1345 	}
1346 	if (!n)
1347 		return NULL;
1348 
1349 	n->m_len = 0;
1350 	if (elen >= M_TRAILINGSPACE(n)) {
1351 		m_free(n);
1352 		return NULL;
1353 	}
1354 
1355 	m_copydata(m, off, elen, mtod(n, void *));
1356 	n->m_len = elen;
1357 	return n;
1358 }
1359 
1360 /*
1361  * Get offset to the previous header followed by the header
1362  * currently processed.
1363  */
1364 int
1365 ip6_get_prevhdr(struct mbuf *m, int off)
1366 {
1367 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1368 
1369 	if (off == sizeof(struct ip6_hdr)) {
1370 		return offsetof(struct ip6_hdr, ip6_nxt);
1371 	} else if (off < sizeof(struct ip6_hdr)) {
1372 		panic("%s: off < sizeof(struct ip6_hdr)", __func__);
1373 	} else {
1374 		int len, nlen, nxt;
1375 		struct ip6_ext ip6e;
1376 
1377 		nxt = ip6->ip6_nxt;
1378 		len = sizeof(struct ip6_hdr);
1379 		nlen = 0;
1380 		while (len < off) {
1381 			m_copydata(m, len, sizeof(ip6e), &ip6e);
1382 
1383 			switch (nxt) {
1384 			case IPPROTO_FRAGMENT:
1385 				nlen = sizeof(struct ip6_frag);
1386 				break;
1387 			case IPPROTO_AH:
1388 				nlen = (ip6e.ip6e_len + 2) << 2;
1389 				break;
1390 			default:
1391 				nlen = (ip6e.ip6e_len + 1) << 3;
1392 				break;
1393 			}
1394 			len += nlen;
1395 			nxt = ip6e.ip6e_nxt;
1396 		}
1397 
1398 		return (len - nlen);
1399 	}
1400 }
1401 
1402 /*
1403  * get next header offset.  m will be retained.
1404  */
1405 int
1406 ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp)
1407 {
1408 	struct ip6_hdr ip6;
1409 	struct ip6_ext ip6e;
1410 	struct ip6_frag fh;
1411 
1412 	/* just in case */
1413 	if (m == NULL)
1414 		panic("%s: m == NULL", __func__);
1415 	if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
1416 		return -1;
1417 
1418 	switch (proto) {
1419 	case IPPROTO_IPV6:
1420 		/* do not chase beyond intermediate IPv6 headers */
1421 		if (off != 0)
1422 			return -1;
1423 		if (m->m_pkthdr.len < off + sizeof(ip6))
1424 			return -1;
1425 		m_copydata(m, off, sizeof(ip6), (void *)&ip6);
1426 		if (nxtp)
1427 			*nxtp = ip6.ip6_nxt;
1428 		off += sizeof(ip6);
1429 		return off;
1430 
1431 	case IPPROTO_FRAGMENT:
1432 		/*
1433 		 * terminate parsing if it is not the first fragment,
1434 		 * it does not make sense to parse through it.
1435 		 */
1436 		if (m->m_pkthdr.len < off + sizeof(fh))
1437 			return -1;
1438 		m_copydata(m, off, sizeof(fh), (void *)&fh);
1439 		if ((fh.ip6f_offlg & IP6F_OFF_MASK) != 0)
1440 			return -1;
1441 		if (nxtp)
1442 			*nxtp = fh.ip6f_nxt;
1443 		off += sizeof(struct ip6_frag);
1444 		return off;
1445 
1446 	case IPPROTO_AH:
1447 		if (m->m_pkthdr.len < off + sizeof(ip6e))
1448 			return -1;
1449 		m_copydata(m, off, sizeof(ip6e), (void *)&ip6e);
1450 		if (nxtp)
1451 			*nxtp = ip6e.ip6e_nxt;
1452 		off += (ip6e.ip6e_len + 2) << 2;
1453 		if (m->m_pkthdr.len < off)
1454 			return -1;
1455 		return off;
1456 
1457 	case IPPROTO_HOPOPTS:
1458 	case IPPROTO_ROUTING:
1459 	case IPPROTO_DSTOPTS:
1460 		if (m->m_pkthdr.len < off + sizeof(ip6e))
1461 			return -1;
1462 		m_copydata(m, off, sizeof(ip6e), (void *)&ip6e);
1463 		if (nxtp)
1464 			*nxtp = ip6e.ip6e_nxt;
1465 		off += (ip6e.ip6e_len + 1) << 3;
1466 		if (m->m_pkthdr.len < off)
1467 			return -1;
1468 		return off;
1469 
1470 	case IPPROTO_NONE:
1471 	case IPPROTO_ESP:
1472 	case IPPROTO_IPCOMP:
1473 		/* give up */
1474 		return -1;
1475 
1476 	default:
1477 		return -1;
1478 	}
1479 }
1480 
1481 /*
1482  * get offset for the last header in the chain.  m will be kept untainted.
1483  */
1484 int
1485 ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp)
1486 {
1487 	int newoff;
1488 	int nxt;
1489 
1490 	if (!nxtp) {
1491 		nxt = -1;
1492 		nxtp = &nxt;
1493 	}
1494 	for (;;) {
1495 		newoff = ip6_nexthdr(m, off, proto, nxtp);
1496 		if (newoff < 0)
1497 			return off;
1498 		else if (newoff < off)
1499 			return -1;	/* invalid */
1500 		else if (newoff == off)
1501 			return newoff;
1502 
1503 		off = newoff;
1504 		proto = *nxtp;
1505 	}
1506 }
1507 
1508 struct m_tag *
1509 ip6_addaux(struct mbuf *m)
1510 {
1511 	struct m_tag *mtag;
1512 
1513 	mtag = m_tag_find(m, PACKET_TAG_INET6, NULL);
1514 	if (!mtag) {
1515 		mtag = m_tag_get(PACKET_TAG_INET6, sizeof(struct ip6aux),
1516 		    M_NOWAIT);
1517 		if (mtag) {
1518 			m_tag_prepend(m, mtag);
1519 			memset(mtag + 1, 0, sizeof(struct ip6aux));
1520 		}
1521 	}
1522 	return mtag;
1523 }
1524 
1525 struct m_tag *
1526 ip6_findaux(struct mbuf *m)
1527 {
1528 	struct m_tag *mtag;
1529 
1530 	mtag = m_tag_find(m, PACKET_TAG_INET6, NULL);
1531 	return mtag;
1532 }
1533 
1534 void
1535 ip6_delaux(struct mbuf *m)
1536 {
1537 	struct m_tag *mtag;
1538 
1539 	mtag = m_tag_find(m, PACKET_TAG_INET6, NULL);
1540 	if (mtag)
1541 		m_tag_delete(m, mtag);
1542 }
1543 
1544 /*
1545  * System control for IP6
1546  */
1547 
1548 const u_char inet6ctlerrmap[PRC_NCMDS] = {
1549 	0,		0,		0,		0,
1550 	0,		EMSGSIZE,	EHOSTDOWN,	EHOSTUNREACH,
1551 	EHOSTUNREACH,	EHOSTUNREACH,	ECONNREFUSED,	ECONNREFUSED,
1552 	EMSGSIZE,	EHOSTUNREACH,	0,		0,
1553 	0,		0,		0,		0,
1554 	ENOPROTOOPT
1555 };
1556 
1557 extern int sysctl_net_inet6_addrctlpolicy(SYSCTLFN_ARGS);
1558 
1559 static int
1560 sysctl_net_inet6_ip6_stats(SYSCTLFN_ARGS)
1561 {
1562 
1563 	return (NETSTAT_SYSCTL(ip6stat_percpu, IP6_NSTATS));
1564 }
1565 
1566 static void
1567 sysctl_net_inet6_ip6_setup(struct sysctllog **clog)
1568 {
1569 
1570 	sysctl_createv(clog, 0, NULL, NULL,
1571 		       CTLFLAG_PERMANENT,
1572 		       CTLTYPE_NODE, "inet6",
1573 		       SYSCTL_DESCR("PF_INET6 related settings"),
1574 		       NULL, 0, NULL, 0,
1575 		       CTL_NET, PF_INET6, CTL_EOL);
1576 	sysctl_createv(clog, 0, NULL, NULL,
1577 		       CTLFLAG_PERMANENT,
1578 		       CTLTYPE_NODE, "ip6",
1579 		       SYSCTL_DESCR("IPv6 related settings"),
1580 		       NULL, 0, NULL, 0,
1581 		       CTL_NET, PF_INET6, IPPROTO_IPV6, CTL_EOL);
1582 
1583 	sysctl_createv(clog, 0, NULL, NULL,
1584 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1585 		       CTLTYPE_INT, "forwarding",
1586 		       SYSCTL_DESCR("Enable forwarding of INET6 datagrams"),
1587 		       NULL, 0, &ip6_forwarding, 0,
1588 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1589 		       IPV6CTL_FORWARDING, CTL_EOL);
1590 	sysctl_createv(clog, 0, NULL, NULL,
1591 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1592 		       CTLTYPE_INT, "redirect",
1593 		       SYSCTL_DESCR("Enable sending of ICMPv6 redirect messages"),
1594 		       NULL, 0, &ip6_sendredirects, 0,
1595 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1596 		       IPV6CTL_SENDREDIRECTS, CTL_EOL);
1597 	sysctl_createv(clog, 0, NULL, NULL,
1598 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1599 		       CTLTYPE_INT, "hlim",
1600 		       SYSCTL_DESCR("Hop limit for an INET6 datagram"),
1601 		       NULL, 0, &ip6_defhlim, 0,
1602 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1603 		       IPV6CTL_DEFHLIM, CTL_EOL);
1604 	sysctl_createv(clog, 0, NULL, NULL,
1605 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1606 		       CTLTYPE_INT, "maxfragpackets",
1607 		       SYSCTL_DESCR("Maximum number of fragments to buffer "
1608 				    "for reassembly"),
1609 		       NULL, 0, &ip6_maxfragpackets, 0,
1610 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1611 		       IPV6CTL_MAXFRAGPACKETS, CTL_EOL);
1612 	sysctl_createv(clog, 0, NULL, NULL,
1613 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1614 		       CTLTYPE_INT, "accept_rtadv",
1615 		       SYSCTL_DESCR("Accept router advertisements"),
1616 		       NULL, 0, &ip6_accept_rtadv, 0,
1617 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1618 		       IPV6CTL_ACCEPT_RTADV, CTL_EOL);
1619 	sysctl_createv(clog, 0, NULL, NULL,
1620 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1621 		       CTLTYPE_INT, "rtadv_maxroutes",
1622 		       SYSCTL_DESCR("Maximum number of routes accepted via router advertisements"),
1623 		       NULL, 0, &ip6_rtadv_maxroutes, 0,
1624 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1625 		       IPV6CTL_RTADV_MAXROUTES, CTL_EOL);
1626 	sysctl_createv(clog, 0, NULL, NULL,
1627 		       CTLFLAG_PERMANENT,
1628 		       CTLTYPE_INT, "rtadv_numroutes",
1629 		       SYSCTL_DESCR("Current number of routes accepted via router advertisements"),
1630 		       NULL, 0, &nd6_numroutes, 0,
1631 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1632 		       IPV6CTL_RTADV_NUMROUTES, CTL_EOL);
1633 	sysctl_createv(clog, 0, NULL, NULL,
1634 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1635 		       CTLTYPE_INT, "keepfaith",
1636 		       SYSCTL_DESCR("Activate faith interface"),
1637 		       NULL, 0, &ip6_keepfaith, 0,
1638 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1639 		       IPV6CTL_KEEPFAITH, CTL_EOL);
1640 	sysctl_createv(clog, 0, NULL, NULL,
1641 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1642 		       CTLTYPE_INT, "log_interval",
1643 		       SYSCTL_DESCR("Minimum interval between logging "
1644 				    "unroutable packets"),
1645 		       NULL, 0, &ip6_log_interval, 0,
1646 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1647 		       IPV6CTL_LOG_INTERVAL, CTL_EOL);
1648 	sysctl_createv(clog, 0, NULL, NULL,
1649 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1650 		       CTLTYPE_INT, "hdrnestlimit",
1651 		       SYSCTL_DESCR("Maximum number of nested IPv6 headers"),
1652 		       NULL, 0, &ip6_hdrnestlimit, 0,
1653 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1654 		       IPV6CTL_HDRNESTLIMIT, CTL_EOL);
1655 	sysctl_createv(clog, 0, NULL, NULL,
1656 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1657 		       CTLTYPE_INT, "dad_count",
1658 		       SYSCTL_DESCR("Number of Duplicate Address Detection "
1659 				    "probes to send"),
1660 		       NULL, 0, &ip6_dad_count, 0,
1661 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1662 		       IPV6CTL_DAD_COUNT, CTL_EOL);
1663 	sysctl_createv(clog, 0, NULL, NULL,
1664 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1665 		       CTLTYPE_INT, "auto_flowlabel",
1666 		       SYSCTL_DESCR("Assign random IPv6 flow labels"),
1667 		       NULL, 0, &ip6_auto_flowlabel, 0,
1668 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1669 		       IPV6CTL_AUTO_FLOWLABEL, CTL_EOL);
1670 	sysctl_createv(clog, 0, NULL, NULL,
1671 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1672 		       CTLTYPE_INT, "defmcasthlim",
1673 		       SYSCTL_DESCR("Default multicast hop limit"),
1674 		       NULL, 0, &ip6_defmcasthlim, 0,
1675 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1676 		       IPV6CTL_DEFMCASTHLIM, CTL_EOL);
1677 	sysctl_createv(clog, 0, NULL, NULL,
1678 		       CTLFLAG_PERMANENT,
1679 		       CTLTYPE_STRING, "kame_version",
1680 		       SYSCTL_DESCR("KAME Version"),
1681 		       NULL, 0, __UNCONST(__KAME_VERSION), 0,
1682 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1683 		       IPV6CTL_KAME_VERSION, CTL_EOL);
1684 	sysctl_createv(clog, 0, NULL, NULL,
1685 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1686 		       CTLTYPE_INT, "use_deprecated",
1687 		       SYSCTL_DESCR("Allow use of deprecated addresses as "
1688 				    "source addresses"),
1689 		       NULL, 0, &ip6_use_deprecated, 0,
1690 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1691 		       IPV6CTL_USE_DEPRECATED, CTL_EOL);
1692 	sysctl_createv(clog, 0, NULL, NULL,
1693 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1694 		       CTLTYPE_INT, "rr_prune", NULL,
1695 		       NULL, 0, &ip6_rr_prune, 0,
1696 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1697 		       IPV6CTL_RR_PRUNE, CTL_EOL);
1698 	sysctl_createv(clog, 0, NULL, NULL,
1699 		       CTLFLAG_PERMANENT
1700 #ifndef INET6_BINDV6ONLY
1701 		       |CTLFLAG_READWRITE,
1702 #endif
1703 		       CTLTYPE_INT, "v6only",
1704 		       SYSCTL_DESCR("Disallow PF_INET6 sockets from connecting "
1705 				    "to PF_INET sockets"),
1706 		       NULL, 0, &ip6_v6only, 0,
1707 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1708 		       IPV6CTL_V6ONLY, CTL_EOL);
1709 	sysctl_createv(clog, 0, NULL, NULL,
1710 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1711 		       CTLTYPE_INT, "anonportmin",
1712 		       SYSCTL_DESCR("Lowest ephemeral port number to assign"),
1713 		       sysctl_net_inet_ip_ports, 0, &ip6_anonportmin, 0,
1714 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1715 		       IPV6CTL_ANONPORTMIN, CTL_EOL);
1716 	sysctl_createv(clog, 0, NULL, NULL,
1717 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1718 		       CTLTYPE_INT, "anonportmax",
1719 		       SYSCTL_DESCR("Highest ephemeral port number to assign"),
1720 		       sysctl_net_inet_ip_ports, 0, &ip6_anonportmax, 0,
1721 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1722 		       IPV6CTL_ANONPORTMAX, CTL_EOL);
1723 #ifndef IPNOPRIVPORTS
1724 	sysctl_createv(clog, 0, NULL, NULL,
1725 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1726 		       CTLTYPE_INT, "lowportmin",
1727 		       SYSCTL_DESCR("Lowest privileged ephemeral port number "
1728 				    "to assign"),
1729 		       sysctl_net_inet_ip_ports, 0, &ip6_lowportmin, 0,
1730 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1731 		       IPV6CTL_LOWPORTMIN, CTL_EOL);
1732 	sysctl_createv(clog, 0, NULL, NULL,
1733 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1734 		       CTLTYPE_INT, "lowportmax",
1735 		       SYSCTL_DESCR("Highest privileged ephemeral port number "
1736 				    "to assign"),
1737 		       sysctl_net_inet_ip_ports, 0, &ip6_lowportmax, 0,
1738 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1739 		       IPV6CTL_LOWPORTMAX, CTL_EOL);
1740 #endif /* IPNOPRIVPORTS */
1741 	sysctl_createv(clog, 0, NULL, NULL,
1742 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1743 		       CTLTYPE_INT, "auto_linklocal",
1744 		       SYSCTL_DESCR("Default value of per-interface flag for "
1745 		                    "adding an IPv6 link-local address to "
1746 				    "interfaces when attached"),
1747 		       NULL, 0, &ip6_auto_linklocal, 0,
1748 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1749 		       IPV6CTL_AUTO_LINKLOCAL, CTL_EOL);
1750 	sysctl_createv(clog, 0, NULL, NULL,
1751 		       CTLFLAG_PERMANENT|CTLFLAG_READONLY,
1752 		       CTLTYPE_STRUCT, "addctlpolicy",
1753 		       SYSCTL_DESCR("Return the current address control"
1754 			   " policy"),
1755 		       sysctl_net_inet6_addrctlpolicy, 0, NULL, 0,
1756 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1757 		       IPV6CTL_ADDRCTLPOLICY, CTL_EOL);
1758 	sysctl_createv(clog, 0, NULL, NULL,
1759 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1760 		       CTLTYPE_INT, "use_tempaddr",
1761 		       SYSCTL_DESCR("Use temporary address"),
1762 		       NULL, 0, &ip6_use_tempaddr, 0,
1763 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1764 		       CTL_CREATE, CTL_EOL);
1765 	sysctl_createv(clog, 0, NULL, NULL,
1766 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1767 		       CTLTYPE_INT, "prefer_tempaddr",
1768 		       SYSCTL_DESCR("Prefer temporary address as source "
1769 		                    "address"),
1770 		       NULL, 0, &ip6_prefer_tempaddr, 0,
1771 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1772 		       CTL_CREATE, CTL_EOL);
1773 	sysctl_createv(clog, 0, NULL, NULL,
1774 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1775 		       CTLTYPE_INT, "temppltime",
1776 		       SYSCTL_DESCR("preferred lifetime of a temporary address"),
1777 		       NULL, 0, &ip6_temp_preferred_lifetime, 0,
1778 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1779 		       CTL_CREATE, CTL_EOL);
1780 	sysctl_createv(clog, 0, NULL, NULL,
1781 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1782 		       CTLTYPE_INT, "tempvltime",
1783 		       SYSCTL_DESCR("valid lifetime of a temporary address"),
1784 		       NULL, 0, &ip6_temp_valid_lifetime, 0,
1785 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1786 		       CTL_CREATE, CTL_EOL);
1787 	sysctl_createv(clog, 0, NULL, NULL,
1788 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1789 		       CTLTYPE_INT, "maxfrags",
1790 		       SYSCTL_DESCR("Maximum fragments in reassembly queue"),
1791 		       NULL, 0, &ip6_maxfrags, 0,
1792 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1793 		       IPV6CTL_MAXFRAGS, CTL_EOL);
1794 	sysctl_createv(clog, 0, NULL, NULL,
1795 		       CTLFLAG_PERMANENT,
1796 		       CTLTYPE_STRUCT, "stats",
1797 		       SYSCTL_DESCR("IPv6 statistics"),
1798 		       sysctl_net_inet6_ip6_stats, 0, NULL, 0,
1799 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1800 		       IPV6CTL_STATS, CTL_EOL);
1801 	sysctl_createv(clog, 0, NULL, NULL,
1802 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1803 		       CTLTYPE_INT, "use_defaultzone",
1804 		       SYSCTL_DESCR("Whether to use the default scope zones"),
1805 		       NULL, 0, &ip6_use_defzone, 0,
1806 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1807 		       IPV6CTL_USE_DEFAULTZONE, CTL_EOL);
1808 	sysctl_createv(clog, 0, NULL, NULL,
1809 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1810 		       CTLTYPE_INT, "mcast_pmtu",
1811 		       SYSCTL_DESCR("Enable pMTU discovery for multicast packet"),
1812 		       NULL, 0, &ip6_mcast_pmtu, 0,
1813 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1814 		       CTL_CREATE, CTL_EOL);
1815 	/* anonportalgo RFC6056 subtree */
1816 	const struct sysctlnode *portalgo_node;
1817 	sysctl_createv(clog, 0, NULL, &portalgo_node,
1818 		       CTLFLAG_PERMANENT,
1819 		       CTLTYPE_NODE, "anonportalgo",
1820 		       SYSCTL_DESCR("Anonymous port algorithm selection (RFC 6056)"),
1821 	    	       NULL, 0, NULL, 0,
1822 		       CTL_NET, PF_INET6, IPPROTO_IPV6, CTL_CREATE, CTL_EOL);
1823 	sysctl_createv(clog, 0, &portalgo_node, NULL,
1824 		       CTLFLAG_PERMANENT,
1825 		       CTLTYPE_STRING, "available",
1826 		       SYSCTL_DESCR("available algorithms"),
1827 		       sysctl_portalgo_available, 0, NULL, PORTALGO_MAXLEN,
1828 		       CTL_CREATE, CTL_EOL);
1829 	sysctl_createv(clog, 0, &portalgo_node, NULL,
1830 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1831 		       CTLTYPE_STRING, "selected",
1832 		       SYSCTL_DESCR("selected algorithm"),
1833 	               sysctl_portalgo_selected6, 0, NULL, PORTALGO_MAXLEN,
1834 		       CTL_CREATE, CTL_EOL);
1835 	sysctl_createv(clog, 0, &portalgo_node, NULL,
1836 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1837 		       CTLTYPE_STRUCT, "reserve",
1838 		       SYSCTL_DESCR("bitmap of reserved ports"),
1839 		       sysctl_portalgo_reserve6, 0, NULL, 0,
1840 		       CTL_CREATE, CTL_EOL);
1841 	sysctl_createv(clog, 0, NULL, NULL,
1842 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1843 		       CTLTYPE_INT, "neighborgcthresh",
1844 		       SYSCTL_DESCR("Maximum number of entries in neighbor"
1845 			" cache"),
1846 		       NULL, 1, &ip6_neighborgcthresh, 0,
1847 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1848 		       CTL_CREATE, CTL_EOL);
1849 	sysctl_createv(clog, 0, NULL, NULL,
1850 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1851 		       CTLTYPE_INT, "maxifprefixes",
1852 		       SYSCTL_DESCR("Maximum number of prefixes created by"
1853 			   " route advertisement per interface"),
1854 		       NULL, 1, &ip6_maxifprefixes, 0,
1855 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1856 		       CTL_CREATE, CTL_EOL);
1857 	sysctl_createv(clog, 0, NULL, NULL,
1858 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1859 		       CTLTYPE_INT, "maxifdefrouters",
1860 		       SYSCTL_DESCR("Maximum number of default routers created"
1861 			   " by route advertisement per interface"),
1862 		       NULL, 1, &ip6_maxifdefrouters, 0,
1863 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1864 		       CTL_CREATE, CTL_EOL);
1865 	sysctl_createv(clog, 0, NULL, NULL,
1866 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1867 		       CTLTYPE_INT, "maxdynroutes",
1868 		       SYSCTL_DESCR("Maximum number of routes created via"
1869 			   " redirect"),
1870 		       NULL, 1, &ip6_maxdynroutes, 0,
1871 		       CTL_NET, PF_INET6, IPPROTO_IPV6,
1872 		       CTL_CREATE, CTL_EOL);
1873 }
1874 
1875 void
1876 ip6_statinc(u_int stat)
1877 {
1878 
1879 	KASSERT(stat < IP6_NSTATS);
1880 	IP6_STATINC(stat);
1881 }
1882