xref: /openbsd-src/sys/netinet6/in6_pcb.c (revision 9f11ffb7133c203312a01e4b986886bc88c7d74b)
1 /*	$OpenBSD: in6_pcb.c,v 1.108 2018/10/04 17:33:41 bluhm 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 int
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 	return 0;
325 }
326 
327 /*
328  * Get the foreign address/port, and put it in a sockaddr_in6.
329  * This services the getpeername(2) call.
330  */
331 int
332 in6_setpeeraddr(struct inpcb *inp, struct mbuf *nam)
333 {
334 	struct sockaddr_in6 *sin6;
335 
336 	nam->m_len = sizeof(struct sockaddr_in6);
337 	sin6 = mtod(nam,struct sockaddr_in6 *);
338 
339 	bzero ((caddr_t)sin6,sizeof(struct sockaddr_in6));
340 	sin6->sin6_family = AF_INET6;
341 	sin6->sin6_len = sizeof(struct sockaddr_in6);
342 	sin6->sin6_port = inp->inp_fport;
343 	sin6->sin6_addr = inp->inp_faddr6;
344 	/* KAME hack: recover scopeid */
345 	in6_recoverscope(sin6, &inp->inp_faddr6);
346 
347 	return 0;
348 }
349 
350 /*
351  * Pass some notification to all connections of a protocol
352  * associated with address dst.  The local address and/or port numbers
353  * may be specified to limit the search.  The "usual action" will be
354  * taken, depending on the ctlinput cmd.  The caller must filter any
355  * cmds that are uninteresting (e.g., no error in the map).
356  * Call the protocol specific routine (if any) to report
357  * any errors for each matching socket.
358  *
359  * Also perform input-side security policy check
360  *    once PCB to be notified has been located.
361  */
362 int
363 in6_pcbnotify(struct inpcbtable *table, struct sockaddr_in6 *dst,
364     uint fport_arg, const struct sockaddr_in6 *src, uint lport_arg,
365     u_int rtable, int cmd, void *cmdarg, void (*notify)(struct inpcb *, int))
366 {
367 	struct inpcb *inp, *ninp;
368 	u_short fport = fport_arg, lport = lport_arg;
369 	struct sockaddr_in6 sa6_src;
370 	int errno, nmatch = 0;
371 	u_int32_t flowinfo;
372 	u_int rdomain;
373 
374 	NET_ASSERT_LOCKED();
375 
376 	if ((unsigned)cmd >= PRC_NCMDS)
377 		return (0);
378 
379 	if (IN6_IS_ADDR_UNSPECIFIED(&dst->sin6_addr))
380 		return (0);
381 	if (IN6_IS_ADDR_V4MAPPED(&dst->sin6_addr)) {
382 #ifdef DIAGNOSTIC
383 		printf("Huh?  Thought in6_pcbnotify() never got "
384 		       "called with mapped!\n");
385 #endif
386 		return (0);
387 	}
388 
389 	/*
390 	 * note that src can be NULL when we get notify by local fragmentation.
391 	 */
392 	sa6_src = (src == NULL) ? sa6_any : *src;
393 	flowinfo = sa6_src.sin6_flowinfo;
394 
395 	/*
396 	 * Redirects go to all references to the destination,
397 	 * and use in_rtchange to invalidate the route cache.
398 	 * Dead host indications: also use in_rtchange to invalidate
399 	 * the cache, and deliver the error to all the sockets.
400 	 * Otherwise, if we have knowledge of the local port and address,
401 	 * deliver only to that socket.
402 	 */
403 	if (PRC_IS_REDIRECT(cmd) || cmd == PRC_HOSTDEAD) {
404 		fport = 0;
405 		lport = 0;
406 		sa6_src.sin6_addr = in6addr_any;
407 
408 		if (cmd != PRC_HOSTDEAD)
409 			notify = in_rtchange;
410 	}
411 	errno = inet6ctlerrmap[cmd];
412 
413 	rdomain = rtable_l2(rtable);
414 	TAILQ_FOREACH_SAFE(inp, &table->inpt_queue, inp_queue, ninp) {
415 		if ((inp->inp_flags & INP_IPV6) == 0)
416 			continue;
417 
418 		/*
419 		 * Under the following condition, notify of redirects
420 		 * to the pcb, without making address matches against inpcb.
421 		 * - redirect notification is arrived.
422 		 * - the inpcb is unconnected.
423 		 * - the inpcb is caching !RTF_HOST routing entry.
424 		 * - the ICMPv6 notification is from the gateway cached in the
425 		 *   inpcb.  i.e. ICMPv6 notification is from nexthop gateway
426 		 *   the inpcb used very recently.
427 		 *
428 		 * This is to improve interaction between netbsd/openbsd
429 		 * redirect handling code, and inpcb route cache code.
430 		 * without the clause, !RTF_HOST routing entry (which carries
431 		 * gateway used by inpcb right before the ICMPv6 redirect)
432 		 * will be cached forever in unconnected inpcb.
433 		 *
434 		 * There still is a question regarding to what is TRT:
435 		 * - On bsdi/freebsd, RTF_HOST (cloned) routing entry will be
436 		 *   generated on packet output.  inpcb will always cache
437 		 *   RTF_HOST routing entry so there's no need for the clause
438 		 *   (ICMPv6 redirect will update RTF_HOST routing entry,
439 		 *   and inpcb is caching it already).
440 		 *   However, bsdi/freebsd are vulnerable to local DoS attacks
441 		 *   due to the cloned routing entries.
442 		 * - Specwise, "destination cache" is mentioned in RFC2461.
443 		 *   Jinmei says that it implies bsdi/freebsd behavior, itojun
444 		 *   is not really convinced.
445 		 * - Having hiwat/lowat on # of cloned host route (redirect/
446 		 *   pmtud) may be a good idea.  netbsd/openbsd has it.  see
447 		 *   icmp6_mtudisc_update().
448 		 */
449 		if ((PRC_IS_REDIRECT(cmd) || cmd == PRC_HOSTDEAD) &&
450 		    IN6_IS_ADDR_UNSPECIFIED(&inp->inp_laddr6) &&
451 		    inp->inp_route.ro_rt &&
452 		    !(inp->inp_route.ro_rt->rt_flags & RTF_HOST)) {
453 			struct sockaddr_in6 *dst6;
454 
455 			dst6 = satosin6(&inp->inp_route.ro_dst);
456 			if (IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr,
457 			    &dst->sin6_addr))
458 				goto do_notify;
459 		}
460 
461 		/*
462 		 * Detect if we should notify the error. If no source and
463 		 * destination ports are specified, but non-zero flowinfo and
464 		 * local address match, notify the error. This is the case
465 		 * when the error is delivered with an encrypted buffer
466 		 * by ESP. Otherwise, just compare addresses and ports
467 		 * as usual.
468 		 */
469 		if (lport == 0 && fport == 0 && flowinfo &&
470 		    inp->inp_socket != NULL &&
471 		    flowinfo == (inp->inp_flowinfo & IPV6_FLOWLABEL_MASK) &&
472 		    IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6, &sa6_src.sin6_addr))
473 			goto do_notify;
474 		else if (!IN6_ARE_ADDR_EQUAL(&inp->inp_faddr6,
475 					     &dst->sin6_addr) ||
476 			 rtable_l2(inp->inp_rtableid) != rdomain ||
477 			 inp->inp_socket == NULL ||
478 			 (lport && inp->inp_lport != lport) ||
479 			 (!IN6_IS_ADDR_UNSPECIFIED(&sa6_src.sin6_addr) &&
480 			  !IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6,
481 					      &sa6_src.sin6_addr)) ||
482 			 (fport && inp->inp_fport != fport)) {
483 			continue;
484 		}
485 	  do_notify:
486 		nmatch++;
487 		if (notify)
488 			(*notify)(inp, errno);
489 	}
490 	return (nmatch);
491 }
492 
493 struct inpcb *
494 in6_pcbhashlookup(struct inpcbtable *table, const struct in6_addr *faddr,
495     u_int fport_arg, const struct in6_addr *laddr, u_int lport_arg,
496     u_int rtable)
497 {
498 	struct inpcbhead *head;
499 	struct inpcb *inp;
500 	u_int16_t fport = fport_arg, lport = lport_arg;
501 	u_int rdomain;
502 
503 	rdomain = rtable_l2(rtable);
504 	head = in6_pcbhash(table, rdomain, faddr, fport, laddr, lport);
505 	LIST_FOREACH(inp, head, inp_hash) {
506 		if (!(inp->inp_flags & INP_IPV6))
507 			continue;
508 		if (IN6_ARE_ADDR_EQUAL(&inp->inp_faddr6, faddr) &&
509 		    inp->inp_fport == fport && inp->inp_lport == lport &&
510 		    IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6, laddr) &&
511 		    rtable_l2(inp->inp_rtableid) == rdomain) {
512 			/*
513 			 * Move this PCB to the head of hash chain so that
514 			 * repeated accesses are quicker.  This is analogous to
515 			 * the historic single-entry PCB cache.
516 			 */
517 			if (inp != LIST_FIRST(head)) {
518 				LIST_REMOVE(inp, inp_hash);
519 				LIST_INSERT_HEAD(head, inp, inp_hash);
520 			}
521 			break;
522 		}
523 	}
524 #ifdef DIAGNOSTIC
525 	if (inp == NULL && in_pcbnotifymiss) {
526 		printf("%s: faddr= fport=%d laddr= lport=%d rdom=%u\n",
527 		    __func__, ntohs(fport), ntohs(lport), rdomain);
528 	}
529 #endif
530 	return (inp);
531 }
532 
533 struct inpcb *
534 in6_pcblookup_listen(struct inpcbtable *table, struct in6_addr *laddr,
535     u_int lport_arg, struct mbuf *m, u_int rtable)
536 {
537 	struct inpcbhead *head;
538 	const struct in6_addr *key1, *key2;
539 	struct inpcb *inp;
540 	u_int16_t lport = lport_arg;
541 	u_int rdomain;
542 
543 	key1 = laddr;
544 	key2 = &zeroin6_addr;
545 #if NPF > 0
546 	if (m && m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) {
547 		struct pf_divert *divert;
548 
549 		divert = pf_find_divert(m);
550 		KASSERT(divert != NULL);
551 		switch (divert->type) {
552 		case PF_DIVERT_TO:
553 			key1 = key2 = &divert->addr.v6;
554 			lport = divert->port;
555 			break;
556 		case PF_DIVERT_REPLY:
557 			return (NULL);
558 		default:
559 			panic("%s: unknown divert type %d, mbuf %p, divert %p",
560 			    __func__, divert->type, m, divert);
561 		}
562 	} else if (m && m->m_pkthdr.pf.flags & PF_TAG_TRANSLATE_LOCALHOST) {
563 		/*
564 		 * Redirected connections should not be treated the same
565 		 * as connections directed to ::1 since localhost
566 		 * can only be accessed from the host itself.
567 		 */
568 		key1 = &zeroin6_addr;
569 		key2 = laddr;
570 	}
571 #endif
572 
573 	rdomain = rtable_l2(rtable);
574 	head = in6_pcbhash(table, rdomain, &zeroin6_addr, 0, key1, lport);
575 	LIST_FOREACH(inp, head, inp_hash) {
576 		if (!(inp->inp_flags & INP_IPV6))
577 			continue;
578 		if (inp->inp_lport == lport && inp->inp_fport == 0 &&
579 		    IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6, key1) &&
580 		    IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6) &&
581 		    rtable_l2(inp->inp_rtableid) == rdomain)
582 			break;
583 	}
584 	if (inp == NULL && ! IN6_ARE_ADDR_EQUAL(key1, key2)) {
585 		head = in6_pcbhash(table, rdomain,
586 		    &zeroin6_addr, 0, key2, lport);
587 		LIST_FOREACH(inp, head, inp_hash) {
588 			if (!(inp->inp_flags & INP_IPV6))
589 				continue;
590 			if (inp->inp_lport == lport && inp->inp_fport == 0 &&
591 			    IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6, key2) &&
592 			    IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6) &&
593 			    rtable_l2(inp->inp_rtableid) == rdomain)
594 				break;
595 		}
596 	}
597 	/*
598 	 * Move this PCB to the head of hash chain so that
599 	 * repeated accesses are quicker.  This is analogous to
600 	 * the historic single-entry PCB cache.
601 	 */
602 	if (inp != NULL && inp != LIST_FIRST(head)) {
603 		LIST_REMOVE(inp, inp_hash);
604 		LIST_INSERT_HEAD(head, inp, inp_hash);
605 	}
606 #ifdef DIAGNOSTIC
607 	if (inp == NULL && in_pcbnotifymiss) {
608 		printf("%s: laddr= lport=%d rdom=%u\n",
609 		    __func__, ntohs(lport), rdomain);
610 	}
611 #endif
612 	return (inp);
613 }
614