xref: /openbsd/sys/netinet6/in6_pcb.c (revision e5dd7070)
1 /*	$OpenBSD: in6_pcb.c,v 1.110 2019/11/29 16:41:01 nayden Exp $	*/
2 
3 /*
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*
33  *	@(#)COPYRIGHT	1.1 (NRL) 17 January 1995
34  *
35  * NRL grants permission for redistribution and use in source and binary
36  * forms, with or without modification, of the software and documentation
37  * created at NRL provided that the following conditions are met:
38  *
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  * 3. All advertising materials mentioning features or use of this software
45  *    must display the following acknowledgements:
46  *	This product includes software developed by the University of
47  *	California, Berkeley and its contributors.
48  *	This product includes software developed at the Information
49  *	Technology Division, US Naval Research Laboratory.
50  * 4. Neither the name of the NRL nor the names of its contributors
51  *    may be used to endorse or promote products derived from this software
52  *    without specific prior written permission.
53  *
54  * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL AND CONTRIBUTORS ``AS
55  * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
56  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
57  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL NRL OR
58  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
59  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
60  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
61  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
62  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
63  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
64  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
65  *
66  * The views and conclusions contained in the software and documentation
67  * are those of the authors and should not be interpreted as representing
68  * official policies, either expressed or implied, of the US Naval
69  * Research Laboratory (NRL).
70  */
71 
72 /*
73  * Copyright (c) 1982, 1986, 1990, 1993, 1995
74  *	Regents of the University of California.  All rights reserved.
75  *
76  * Redistribution and use in source and binary forms, with or without
77  * modification, are permitted provided that the following conditions
78  * are met:
79  * 1. Redistributions of source code must retain the above copyright
80  *    notice, this list of conditions and the following disclaimer.
81  * 2. Redistributions in binary form must reproduce the above copyright
82  *    notice, this list of conditions and the following disclaimer in the
83  *    documentation and/or other materials provided with the distribution.
84  * 3. Neither the name of the University nor the names of its contributors
85  *    may be used to endorse or promote products derived from this software
86  *    without specific prior written permission.
87  *
88  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
89  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
90  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
91  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
92  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
93  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
94  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
95  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
96  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
97  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
98  * SUCH DAMAGE.
99  *
100  */
101 
102 #include "pf.h"
103 
104 #include <sys/param.h>
105 #include <sys/systm.h>
106 #include <sys/mbuf.h>
107 #include <sys/protosw.h>
108 #include <sys/socket.h>
109 #include <sys/socketvar.h>
110 
111 #include <net/if.h>
112 #include <net/if_var.h>
113 #include <net/pfvar.h>
114 
115 #include <netinet/in.h>
116 #include <netinet/ip.h>
117 #include <netinet/ip_var.h>
118 #include <netinet/in_pcb.h>
119 
120 #include <netinet6/in6_var.h>
121 
122 const struct in6_addr zeroin6_addr;
123 
124 struct inpcbhead *
125 in6_pcbhash(struct inpcbtable *table, int rdom,
126     const struct in6_addr *faddr, u_short fport,
127     const struct in6_addr *laddr, u_short lport)
128 {
129 	SIPHASH_CTX ctx;
130 	u_int32_t nrdom = htonl(rdom);
131 
132 	SipHash24_Init(&ctx, &table->inpt_key);
133 	SipHash24_Update(&ctx, &nrdom, sizeof(nrdom));
134 	SipHash24_Update(&ctx, faddr, sizeof(*faddr));
135 	SipHash24_Update(&ctx, &fport, sizeof(fport));
136 	SipHash24_Update(&ctx, laddr, sizeof(*laddr));
137 	SipHash24_Update(&ctx, &lport, sizeof(lport));
138 
139 	return (&table->inpt_hashtbl[SipHash24_End(&ctx) & table->inpt_mask]);
140 }
141 
142 int
143 in6_pcbaddrisavail(struct inpcb *inp, struct sockaddr_in6 *sin6, int wild,
144     struct proc *p)
145 {
146 	struct socket *so = inp->inp_socket;
147 	struct inpcbtable *table = inp->inp_table;
148 	u_short lport = sin6->sin6_port;
149 	int reuseport = (so->so_options & SO_REUSEPORT);
150 
151 	wild |= INPLOOKUP_IPV6;
152 	/* KAME hack: embed scopeid */
153 	if (in6_embedscope(&sin6->sin6_addr, sin6, inp) != 0)
154 		return (EINVAL);
155 	/* this must be cleared for ifa_ifwithaddr() */
156 	sin6->sin6_scope_id = 0;
157 	/* reject IPv4 mapped address, we have no support for it */
158 	if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
159 		return (EADDRNOTAVAIL);
160 
161 	if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) {
162 		/*
163 		 * Treat SO_REUSEADDR as SO_REUSEPORT for multicast;
164 		 * allow complete duplication of binding if
165 		 * SO_REUSEPORT is set, or if SO_REUSEADDR is set
166 		 * and a multicast address is bound on both
167 		 * new and duplicated sockets.
168 		 */
169 		if (so->so_options & (SO_REUSEADDR|SO_REUSEPORT))
170 			reuseport = SO_REUSEADDR | SO_REUSEPORT;
171 	} else if (!IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
172 		struct ifaddr *ifa = NULL;
173 
174 		sin6->sin6_port = 0;  /*
175 				       * Yechhhh, because of upcoming
176 				       * call to ifa_ifwithaddr(), which
177 				       * does bcmp's over the PORTS as
178 				       * well.  (What about flow?)
179 				       */
180 		sin6->sin6_flowinfo = 0;
181 		if (!(so->so_options & SO_BINDANY) &&
182 		    (ifa = ifa_ifwithaddr(sin6tosa(sin6),
183 		    inp->inp_rtableid)) == NULL)
184 			return (EADDRNOTAVAIL);
185 		sin6->sin6_port = lport;
186 
187 		/*
188 		 * bind to an anycast address might accidentally
189 		 * cause sending a packet with an anycast source
190 		 * address, so we forbid it.
191 		 *
192 		 * We should allow to bind to a deprecated address,
193 		 * since the application dare to use it.
194 		 * But, can we assume that they are careful enough
195 		 * to check if the address is deprecated or not?
196 		 * Maybe, as a safeguard, we should have a setsockopt
197 		 * flag to control the bind(2) behavior against
198 		 * deprecated addresses (default: forbid bind(2)).
199 		 */
200 		if (ifa && ifatoia6(ifa)->ia6_flags & (IN6_IFF_ANYCAST|
201 		    IN6_IFF_TENTATIVE|IN6_IFF_DUPLICATED|IN6_IFF_DETACHED))
202 			return (EADDRNOTAVAIL);
203 	}
204 	if (lport) {
205 		struct inpcb *t;
206 
207 		if (so->so_euid) {
208 			t = in_pcblookup_local(table,
209 			    (struct in_addr *)&sin6->sin6_addr, lport,
210 			    INPLOOKUP_WILDCARD | INPLOOKUP_IPV6,
211 			    inp->inp_rtableid);
212 			if (t && (so->so_euid != t->inp_socket->so_euid))
213 				return (EADDRINUSE);
214 		}
215 		t = in_pcblookup_local(table,
216 		    (struct in_addr *)&sin6->sin6_addr, lport,
217 		    wild, inp->inp_rtableid);
218 		if (t && (reuseport & t->inp_socket->so_options) == 0)
219 			return (EADDRINUSE);
220 	}
221 	return (0);
222 }
223 
224 /*
225  * Connect from a socket to a specified address.
226  * Both address and port must be specified in argument sin6.
227  * Eventually, flow labels will have to be dealt with here, as well.
228  *
229  * If don't have a local address for this socket yet,
230  * then pick one.
231  */
232 int
233 in6_pcbconnect(struct inpcb *inp, struct mbuf *nam)
234 {
235 	struct in6_addr *in6a = NULL;
236 	struct sockaddr_in6 *sin6;
237 	int error;
238 	struct sockaddr_in6 tmp;
239 
240 	KASSERT(inp->inp_flags & INP_IPV6);
241 
242 	if ((error = in6_nam2sin6(nam, &sin6)))
243 		return (error);
244 	if (sin6->sin6_port == 0)
245 		return (EADDRNOTAVAIL);
246 	/* reject IPv4 mapped address, we have no support for it */
247 	if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
248 		return (EADDRNOTAVAIL);
249 
250 	/* protect *sin6 from overwrites */
251 	tmp = *sin6;
252 	sin6 = &tmp;
253 
254 	/* KAME hack: embed scopeid */
255 	if (in6_embedscope(&sin6->sin6_addr, sin6, inp) != 0)
256 		return EINVAL;
257 	/* this must be cleared for ifa_ifwithaddr() */
258 	sin6->sin6_scope_id = 0;
259 
260 	/* Source address selection. */
261 	/*
262 	 * XXX: in6_selectsrc might replace the bound local address
263 	 * with the address specified by setsockopt(IPV6_PKTINFO).
264 	 * Is it the intended behavior?
265 	 */
266 	error = in6_pcbselsrc(&in6a, sin6, inp, inp->inp_outputopts6);
267 	if (error)
268 		return (error);
269 
270 	inp->inp_ipv6.ip6_hlim = (u_int8_t)in6_selecthlim(inp);
271 
272 	if (in6_pcbhashlookup(inp->inp_table, &sin6->sin6_addr, sin6->sin6_port,
273 	    IN6_IS_ADDR_UNSPECIFIED(&inp->inp_laddr6) ? in6a : &inp->inp_laddr6,
274 	    inp->inp_lport, inp->inp_rtableid) != NULL) {
275 		return (EADDRINUSE);
276 	}
277 
278 	KASSERT(IN6_IS_ADDR_UNSPECIFIED(&inp->inp_laddr6) || inp->inp_lport);
279 
280 	if (IN6_IS_ADDR_UNSPECIFIED(&inp->inp_laddr6)) {
281 		if (inp->inp_lport == 0) {
282 			error = in_pcbbind(inp, NULL, curproc);
283 			if (error)
284 				return (error);
285 			if (in6_pcbhashlookup(inp->inp_table, &sin6->sin6_addr,
286 			    sin6->sin6_port, in6a, inp->inp_lport,
287 			    inp->inp_rtableid) != NULL) {
288 				inp->inp_lport = 0;
289 				return (EADDRINUSE);
290 			}
291 		}
292 		inp->inp_laddr6 = *in6a;
293 	}
294 	inp->inp_faddr6 = sin6->sin6_addr;
295 	inp->inp_fport = sin6->sin6_port;
296 	inp->inp_flowinfo &= ~IPV6_FLOWLABEL_MASK;
297 	if (ip6_auto_flowlabel)
298 		inp->inp_flowinfo |=
299 		    (htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK);
300 	in_pcbrehash(inp);
301 	return (0);
302 }
303 
304 /*
305  * Get the local address/port, and put it in a sockaddr_in6.
306  * This services the getsockname(2) call.
307  */
308 void
309 in6_setsockaddr(struct inpcb *inp, struct mbuf *nam)
310 {
311 	struct sockaddr_in6 *sin6;
312 
313 	nam->m_len = sizeof(struct sockaddr_in6);
314 	sin6 = mtod(nam,struct sockaddr_in6 *);
315 
316 	bzero ((caddr_t)sin6,sizeof(struct sockaddr_in6));
317 	sin6->sin6_family = AF_INET6;
318 	sin6->sin6_len = sizeof(struct sockaddr_in6);
319 	sin6->sin6_port = inp->inp_lport;
320 	sin6->sin6_addr = inp->inp_laddr6;
321 	/* KAME hack: recover scopeid */
322 	in6_recoverscope(sin6, &inp->inp_laddr6);
323 }
324 
325 /*
326  * Get the foreign address/port, and put it in a sockaddr_in6.
327  * This services the getpeername(2) call.
328  */
329 void
330 in6_setpeeraddr(struct inpcb *inp, struct mbuf *nam)
331 {
332 	struct sockaddr_in6 *sin6;
333 
334 	nam->m_len = sizeof(struct sockaddr_in6);
335 	sin6 = mtod(nam,struct sockaddr_in6 *);
336 
337 	bzero ((caddr_t)sin6,sizeof(struct sockaddr_in6));
338 	sin6->sin6_family = AF_INET6;
339 	sin6->sin6_len = sizeof(struct sockaddr_in6);
340 	sin6->sin6_port = inp->inp_fport;
341 	sin6->sin6_addr = inp->inp_faddr6;
342 	/* KAME hack: recover scopeid */
343 	in6_recoverscope(sin6, &inp->inp_faddr6);
344 }
345 
346 /*
347  * Pass some notification to all connections of a protocol
348  * associated with address dst.  The local address and/or port numbers
349  * may be specified to limit the search.  The "usual action" will be
350  * taken, depending on the ctlinput cmd.  The caller must filter any
351  * cmds that are uninteresting (e.g., no error in the map).
352  * Call the protocol specific routine (if any) to report
353  * any errors for each matching socket.
354  *
355  * Also perform input-side security policy check
356  *    once PCB to be notified has been located.
357  */
358 int
359 in6_pcbnotify(struct inpcbtable *table, struct sockaddr_in6 *dst,
360     uint fport_arg, const struct sockaddr_in6 *src, uint lport_arg,
361     u_int rtable, int cmd, void *cmdarg, void (*notify)(struct inpcb *, int))
362 {
363 	struct inpcb *inp, *ninp;
364 	u_short fport = fport_arg, lport = lport_arg;
365 	struct sockaddr_in6 sa6_src;
366 	int errno, nmatch = 0;
367 	u_int32_t flowinfo;
368 	u_int rdomain;
369 
370 	NET_ASSERT_LOCKED();
371 
372 	if ((unsigned)cmd >= PRC_NCMDS)
373 		return (0);
374 
375 	if (IN6_IS_ADDR_UNSPECIFIED(&dst->sin6_addr))
376 		return (0);
377 	if (IN6_IS_ADDR_V4MAPPED(&dst->sin6_addr)) {
378 #ifdef DIAGNOSTIC
379 		printf("%s: Huh?  Thought we never got "
380 		       "called with mapped!\n", __func__);
381 #endif
382 		return (0);
383 	}
384 
385 	/*
386 	 * note that src can be NULL when we get notify by local fragmentation.
387 	 */
388 	sa6_src = (src == NULL) ? sa6_any : *src;
389 	flowinfo = sa6_src.sin6_flowinfo;
390 
391 	/*
392 	 * Redirects go to all references to the destination,
393 	 * and use in_rtchange to invalidate the route cache.
394 	 * Dead host indications: also use in_rtchange to invalidate
395 	 * the cache, and deliver the error to all the sockets.
396 	 * Otherwise, if we have knowledge of the local port and address,
397 	 * deliver only to that socket.
398 	 */
399 	if (PRC_IS_REDIRECT(cmd) || cmd == PRC_HOSTDEAD) {
400 		fport = 0;
401 		lport = 0;
402 		sa6_src.sin6_addr = in6addr_any;
403 
404 		if (cmd != PRC_HOSTDEAD)
405 			notify = in_rtchange;
406 	}
407 	errno = inet6ctlerrmap[cmd];
408 
409 	rdomain = rtable_l2(rtable);
410 	TAILQ_FOREACH_SAFE(inp, &table->inpt_queue, inp_queue, ninp) {
411 		if ((inp->inp_flags & INP_IPV6) == 0)
412 			continue;
413 
414 		/*
415 		 * Under the following condition, notify of redirects
416 		 * to the pcb, without making address matches against inpcb.
417 		 * - redirect notification is arrived.
418 		 * - the inpcb is unconnected.
419 		 * - the inpcb is caching !RTF_HOST routing entry.
420 		 * - the ICMPv6 notification is from the gateway cached in the
421 		 *   inpcb.  i.e. ICMPv6 notification is from nexthop gateway
422 		 *   the inpcb used very recently.
423 		 *
424 		 * This is to improve interaction between netbsd/openbsd
425 		 * redirect handling code, and inpcb route cache code.
426 		 * without the clause, !RTF_HOST routing entry (which carries
427 		 * gateway used by inpcb right before the ICMPv6 redirect)
428 		 * will be cached forever in unconnected inpcb.
429 		 *
430 		 * There still is a question regarding to what is TRT:
431 		 * - On bsdi/freebsd, RTF_HOST (cloned) routing entry will be
432 		 *   generated on packet output.  inpcb will always cache
433 		 *   RTF_HOST routing entry so there's no need for the clause
434 		 *   (ICMPv6 redirect will update RTF_HOST routing entry,
435 		 *   and inpcb is caching it already).
436 		 *   However, bsdi/freebsd are vulnerable to local DoS attacks
437 		 *   due to the cloned routing entries.
438 		 * - Specwise, "destination cache" is mentioned in RFC2461.
439 		 *   Jinmei says that it implies bsdi/freebsd behavior, itojun
440 		 *   is not really convinced.
441 		 * - Having hiwat/lowat on # of cloned host route (redirect/
442 		 *   pmtud) may be a good idea.  netbsd/openbsd has it.  see
443 		 *   icmp6_mtudisc_update().
444 		 */
445 		if ((PRC_IS_REDIRECT(cmd) || cmd == PRC_HOSTDEAD) &&
446 		    IN6_IS_ADDR_UNSPECIFIED(&inp->inp_laddr6) &&
447 		    inp->inp_route.ro_rt &&
448 		    !(inp->inp_route.ro_rt->rt_flags & RTF_HOST)) {
449 			struct sockaddr_in6 *dst6;
450 
451 			dst6 = satosin6(&inp->inp_route.ro_dst);
452 			if (IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr,
453 			    &dst->sin6_addr))
454 				goto do_notify;
455 		}
456 
457 		/*
458 		 * Detect if we should notify the error. If no source and
459 		 * destination ports are specified, but non-zero flowinfo and
460 		 * local address match, notify the error. This is the case
461 		 * when the error is delivered with an encrypted buffer
462 		 * by ESP. Otherwise, just compare addresses and ports
463 		 * as usual.
464 		 */
465 		if (lport == 0 && fport == 0 && flowinfo &&
466 		    inp->inp_socket != NULL &&
467 		    flowinfo == (inp->inp_flowinfo & IPV6_FLOWLABEL_MASK) &&
468 		    IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6, &sa6_src.sin6_addr))
469 			goto do_notify;
470 		else if (!IN6_ARE_ADDR_EQUAL(&inp->inp_faddr6,
471 					     &dst->sin6_addr) ||
472 			 rtable_l2(inp->inp_rtableid) != rdomain ||
473 			 inp->inp_socket == NULL ||
474 			 (lport && inp->inp_lport != lport) ||
475 			 (!IN6_IS_ADDR_UNSPECIFIED(&sa6_src.sin6_addr) &&
476 			  !IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6,
477 					      &sa6_src.sin6_addr)) ||
478 			 (fport && inp->inp_fport != fport)) {
479 			continue;
480 		}
481 	  do_notify:
482 		nmatch++;
483 		if (notify)
484 			(*notify)(inp, errno);
485 	}
486 	return (nmatch);
487 }
488 
489 struct inpcb *
490 in6_pcbhashlookup(struct inpcbtable *table, const struct in6_addr *faddr,
491     u_int fport_arg, const struct in6_addr *laddr, u_int lport_arg,
492     u_int rtable)
493 {
494 	struct inpcbhead *head;
495 	struct inpcb *inp;
496 	u_int16_t fport = fport_arg, lport = lport_arg;
497 	u_int rdomain;
498 
499 	rdomain = rtable_l2(rtable);
500 	head = in6_pcbhash(table, rdomain, faddr, fport, laddr, lport);
501 	LIST_FOREACH(inp, head, inp_hash) {
502 		if (!(inp->inp_flags & INP_IPV6))
503 			continue;
504 		if (IN6_ARE_ADDR_EQUAL(&inp->inp_faddr6, faddr) &&
505 		    inp->inp_fport == fport && inp->inp_lport == lport &&
506 		    IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6, laddr) &&
507 		    rtable_l2(inp->inp_rtableid) == rdomain) {
508 			/*
509 			 * Move this PCB to the head of hash chain so that
510 			 * repeated accesses are quicker.  This is analogous to
511 			 * the historic single-entry PCB cache.
512 			 */
513 			if (inp != LIST_FIRST(head)) {
514 				LIST_REMOVE(inp, inp_hash);
515 				LIST_INSERT_HEAD(head, inp, inp_hash);
516 			}
517 			break;
518 		}
519 	}
520 #ifdef DIAGNOSTIC
521 	if (inp == NULL && in_pcbnotifymiss) {
522 		printf("%s: faddr= fport=%d laddr= lport=%d rdom=%u\n",
523 		    __func__, ntohs(fport), ntohs(lport), rdomain);
524 	}
525 #endif
526 	return (inp);
527 }
528 
529 struct inpcb *
530 in6_pcblookup_listen(struct inpcbtable *table, struct in6_addr *laddr,
531     u_int lport_arg, struct mbuf *m, u_int rtable)
532 {
533 	struct inpcbhead *head;
534 	const struct in6_addr *key1, *key2;
535 	struct inpcb *inp;
536 	u_int16_t lport = lport_arg;
537 	u_int rdomain;
538 
539 	key1 = laddr;
540 	key2 = &zeroin6_addr;
541 #if NPF > 0
542 	if (m && m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) {
543 		struct pf_divert *divert;
544 
545 		divert = pf_find_divert(m);
546 		KASSERT(divert != NULL);
547 		switch (divert->type) {
548 		case PF_DIVERT_TO:
549 			key1 = key2 = &divert->addr.v6;
550 			lport = divert->port;
551 			break;
552 		case PF_DIVERT_REPLY:
553 			return (NULL);
554 		default:
555 			panic("%s: unknown divert type %d, mbuf %p, divert %p",
556 			    __func__, divert->type, m, divert);
557 		}
558 	} else if (m && m->m_pkthdr.pf.flags & PF_TAG_TRANSLATE_LOCALHOST) {
559 		/*
560 		 * Redirected connections should not be treated the same
561 		 * as connections directed to ::1 since localhost
562 		 * can only be accessed from the host itself.
563 		 */
564 		key1 = &zeroin6_addr;
565 		key2 = laddr;
566 	}
567 #endif
568 
569 	rdomain = rtable_l2(rtable);
570 	head = in6_pcbhash(table, rdomain, &zeroin6_addr, 0, key1, lport);
571 	LIST_FOREACH(inp, head, inp_hash) {
572 		if (!(inp->inp_flags & INP_IPV6))
573 			continue;
574 		if (inp->inp_lport == lport && inp->inp_fport == 0 &&
575 		    IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6, key1) &&
576 		    IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6) &&
577 		    rtable_l2(inp->inp_rtableid) == rdomain)
578 			break;
579 	}
580 	if (inp == NULL && ! IN6_ARE_ADDR_EQUAL(key1, key2)) {
581 		head = in6_pcbhash(table, rdomain,
582 		    &zeroin6_addr, 0, key2, lport);
583 		LIST_FOREACH(inp, head, inp_hash) {
584 			if (!(inp->inp_flags & INP_IPV6))
585 				continue;
586 			if (inp->inp_lport == lport && inp->inp_fport == 0 &&
587 			    IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6, key2) &&
588 			    IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6) &&
589 			    rtable_l2(inp->inp_rtableid) == rdomain)
590 				break;
591 		}
592 	}
593 	/*
594 	 * Move this PCB to the head of hash chain so that
595 	 * repeated accesses are quicker.  This is analogous to
596 	 * the historic single-entry PCB cache.
597 	 */
598 	if (inp != NULL && inp != LIST_FIRST(head)) {
599 		LIST_REMOVE(inp, inp_hash);
600 		LIST_INSERT_HEAD(head, inp, inp_hash);
601 	}
602 #ifdef DIAGNOSTIC
603 	if (inp == NULL && in_pcbnotifymiss) {
604 		printf("%s: laddr= lport=%d rdom=%u\n",
605 		    __func__, ntohs(lport), rdomain);
606 	}
607 #endif
608 	return (inp);
609 }
610