xref: /openbsd-src/sys/netinet/in_pcb.c (revision d1df930ffab53da22f3324c32bed7ac5709915e6)
1 /*	$OpenBSD: in_pcb.c,v 1.246 2018/09/20 18:59:10 bluhm Exp $	*/
2 /*	$NetBSD: in_pcb.c,v 1.25 1996/02/13 23:41:53 christos Exp $	*/
3 
4 /*
5  * Copyright (c) 1982, 1986, 1991, 1993
6  *	The Regents of the University of California.  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 University 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 REGENTS 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 REGENTS 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  *	@(#)COPYRIGHT	1.1 (NRL) 17 January 1995
33  *
34  * NRL grants permission for redistribution and use in source and binary
35  * forms, with or without modification, of the software and documentation
36  * created at NRL provided that the following conditions are met:
37  *
38  * 1. Redistributions of source code must retain the above copyright
39  *    notice, this list of conditions and the following disclaimer.
40  * 2. Redistributions in binary form must reproduce the above copyright
41  *    notice, this list of conditions and the following disclaimer in the
42  *    documentation and/or other materials provided with the distribution.
43  * 3. All advertising materials mentioning features or use of this software
44  *    must display the following acknowledgements:
45  *	This product includes software developed by the University of
46  *	California, Berkeley and its contributors.
47  *	This product includes software developed at the Information
48  *	Technology Division, US Naval Research Laboratory.
49  * 4. Neither the name of the NRL nor the names of its contributors
50  *    may be used to endorse or promote products derived from this software
51  *    without specific prior written permission.
52  *
53  * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL AND CONTRIBUTORS ``AS
54  * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
55  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
56  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL NRL OR
57  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
58  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
59  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
60  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
61  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
62  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
63  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
64  *
65  * The views and conclusions contained in the software and documentation
66  * are those of the authors and should not be interpreted as representing
67  * official policies, either expressed or implied, of the US Naval
68  * Research Laboratory (NRL).
69  */
70 
71 #include "pf.h"
72 
73 #include <sys/param.h>
74 #include <sys/systm.h>
75 #include <sys/mbuf.h>
76 #include <sys/protosw.h>
77 #include <sys/socket.h>
78 #include <sys/socketvar.h>
79 #include <sys/domain.h>
80 #include <sys/mount.h>
81 #include <sys/pool.h>
82 #include <sys/proc.h>
83 
84 #include <net/if.h>
85 #include <net/if_var.h>
86 #include <net/pfvar.h>
87 #include <net/route.h>
88 
89 #include <netinet/in.h>
90 #include <netinet/in_var.h>
91 #include <netinet/ip.h>
92 #include <netinet/ip_var.h>
93 #include <netinet/in_pcb.h>
94 #ifdef IPSEC
95 #include <netinet/ip_esp.h>
96 #endif /* IPSEC */
97 
98 const struct in_addr zeroin_addr;
99 
100 union {
101 	struct in_addr	za_in;
102 	struct in6_addr	za_in6;
103 } zeroin46_addr;
104 
105 /*
106  * These configure the range of local port addresses assigned to
107  * "unspecified" outgoing connections/packets/whatever.
108  */
109 int ipport_firstauto = IPPORT_RESERVED;
110 int ipport_lastauto = IPPORT_USERRESERVED;
111 int ipport_hifirstauto = IPPORT_HIFIRSTAUTO;
112 int ipport_hilastauto = IPPORT_HILASTAUTO;
113 
114 /* Protect PCB table queues, lookup hashes and existence of inpcb. */
115 struct mutex inpcbtable_mtx = MUTEX_INITIALIZER(IPL_SOFTNET);
116 
117 struct baddynamicports baddynamicports;
118 struct baddynamicports rootonlyports;
119 struct pool inpcb_pool;
120 int inpcb_pool_initialized = 0;
121 
122 void	in_pcbrehash_locked(struct inpcb *);
123 int	in_pcbresize(struct inpcbtable *, int);
124 
125 #define	INPCBHASH_LOADFACTOR(_x)	(((_x) * 3) / 4)
126 
127 struct inpcbhead *in_pcbhash(struct inpcbtable *, int,
128     const struct in_addr *, u_short, const struct in_addr *, u_short);
129 struct inpcbhead *in_pcblhash(struct inpcbtable *, int, u_short);
130 
131 struct inpcbhead *
132 in_pcbhash(struct inpcbtable *table, int rdom,
133     const struct in_addr *faddr, u_short fport,
134     const struct in_addr *laddr, u_short lport)
135 {
136 	SIPHASH_CTX ctx;
137 	u_int32_t nrdom = htonl(rdom);
138 
139 	SipHash24_Init(&ctx, &table->inpt_key);
140 	SipHash24_Update(&ctx, &nrdom, sizeof(nrdom));
141 	SipHash24_Update(&ctx, faddr, sizeof(*faddr));
142 	SipHash24_Update(&ctx, &fport, sizeof(fport));
143 	SipHash24_Update(&ctx, laddr, sizeof(*laddr));
144 	SipHash24_Update(&ctx, &lport, sizeof(lport));
145 
146 	return (&table->inpt_hashtbl[SipHash24_End(&ctx) & table->inpt_mask]);
147 }
148 
149 struct inpcbhead *
150 in_pcblhash(struct inpcbtable *table, int rdom, u_short lport)
151 {
152 	SIPHASH_CTX ctx;
153 	u_int32_t nrdom = htonl(rdom);
154 
155 	SipHash24_Init(&ctx, &table->inpt_lkey);
156 	SipHash24_Update(&ctx, &nrdom, sizeof(nrdom));
157 	SipHash24_Update(&ctx, &lport, sizeof(lport));
158 
159 	return (&table->inpt_lhashtbl[SipHash24_End(&ctx) & table->inpt_lmask]);
160 }
161 
162 void
163 in_pcbinit(struct inpcbtable *table, int hashsize)
164 {
165 
166 	mtx_enter(&inpcbtable_mtx);
167 	TAILQ_INIT(&table->inpt_queue);
168 	table->inpt_hashtbl = hashinit(hashsize, M_PCB, M_NOWAIT,
169 	    &table->inpt_mask);
170 	if (table->inpt_hashtbl == NULL)
171 		panic("in_pcbinit: hashinit failed");
172 	table->inpt_lhashtbl = hashinit(hashsize, M_PCB, M_NOWAIT,
173 	    &table->inpt_lmask);
174 	if (table->inpt_lhashtbl == NULL)
175 		panic("in_pcbinit: hashinit failed for lport");
176 	table->inpt_count = 0;
177 	table->inpt_size = hashsize;
178 	arc4random_buf(&table->inpt_key, sizeof(table->inpt_key));
179 	arc4random_buf(&table->inpt_lkey, sizeof(table->inpt_lkey));
180 	mtx_leave(&inpcbtable_mtx);
181 }
182 
183 /*
184  * Check if the specified port is invalid for dynamic allocation.
185  */
186 int
187 in_baddynamic(u_int16_t port, u_int16_t proto)
188 {
189 	switch (proto) {
190 	case IPPROTO_TCP:
191 		return (DP_ISSET(baddynamicports.tcp, port));
192 	case IPPROTO_UDP:
193 #ifdef IPSEC
194 		/* Cannot preset this as it is a sysctl */
195 		if (port == udpencap_port)
196 			return (1);
197 #endif
198 		return (DP_ISSET(baddynamicports.udp, port));
199 	default:
200 		return (0);
201 	}
202 }
203 
204 int
205 in_rootonly(u_int16_t port, u_int16_t proto)
206 {
207 	switch (proto) {
208 	case IPPROTO_TCP:
209 		return (port < IPPORT_RESERVED ||
210 		    DP_ISSET(rootonlyports.tcp, port));
211 	case IPPROTO_UDP:
212 		return (port < IPPORT_RESERVED ||
213 		    DP_ISSET(rootonlyports.udp, port));
214 	default:
215 		return (0);
216 	}
217 }
218 
219 int
220 in_pcballoc(struct socket *so, struct inpcbtable *table)
221 {
222 	struct inpcb *inp;
223 	struct inpcbhead *head;
224 
225 	NET_ASSERT_LOCKED();
226 
227 	if (inpcb_pool_initialized == 0) {
228 		pool_init(&inpcb_pool, sizeof(struct inpcb), 0,
229 		    IPL_SOFTNET, 0, "inpcbpl", NULL);
230 		inpcb_pool_initialized = 1;
231 	}
232 	inp = pool_get(&inpcb_pool, PR_NOWAIT|PR_ZERO);
233 	if (inp == NULL)
234 		return (ENOBUFS);
235 	inp->inp_table = table;
236 	inp->inp_socket = so;
237 	refcnt_init(&inp->inp_refcnt);
238 	inp->inp_seclevel[SL_AUTH] = IPSEC_AUTH_LEVEL_DEFAULT;
239 	inp->inp_seclevel[SL_ESP_TRANS] = IPSEC_ESP_TRANS_LEVEL_DEFAULT;
240 	inp->inp_seclevel[SL_ESP_NETWORK] = IPSEC_ESP_NETWORK_LEVEL_DEFAULT;
241 	inp->inp_seclevel[SL_IPCOMP] = IPSEC_IPCOMP_LEVEL_DEFAULT;
242 	inp->inp_rtableid = curproc->p_p->ps_rtableid;
243 	inp->inp_hops = -1;
244 #ifdef INET6
245 	/*
246 	 * Small change in this function to set the INP_IPV6 flag so routines
247 	 * outside pcb-specific routines don't need to use sotopf(), and all
248 	 * of its pointer chasing, later.
249 	 */
250 	if (sotopf(so) == PF_INET6)
251 		inp->inp_flags = INP_IPV6;
252 	inp->inp_cksum6 = -1;
253 #endif /* INET6 */
254 
255 	mtx_enter(&inpcbtable_mtx);
256 	if (table->inpt_count++ > INPCBHASH_LOADFACTOR(table->inpt_size))
257 		(void)in_pcbresize(table, table->inpt_size * 2);
258 	TAILQ_INSERT_HEAD(&table->inpt_queue, inp, inp_queue);
259 	head = in_pcblhash(table, inp->inp_rtableid, inp->inp_lport);
260 	LIST_INSERT_HEAD(head, inp, inp_lhash);
261 #ifdef INET6
262 	if (sotopf(so) == PF_INET6)
263 		head = in6_pcbhash(table, rtable_l2(inp->inp_rtableid),
264 		    &inp->inp_faddr6, inp->inp_fport,
265 		    &inp->inp_laddr6, inp->inp_lport);
266 	else
267 #endif /* INET6 */
268 		head = in_pcbhash(table, rtable_l2(inp->inp_rtableid),
269 		    &inp->inp_faddr, inp->inp_fport,
270 		    &inp->inp_laddr, inp->inp_lport);
271 	LIST_INSERT_HEAD(head, inp, inp_hash);
272 	mtx_leave(&inpcbtable_mtx);
273 
274 	so->so_pcb = inp;
275 
276 	return (0);
277 }
278 
279 int
280 in_pcbbind(struct inpcb *inp, struct mbuf *nam, struct proc *p)
281 {
282 	struct socket *so = inp->inp_socket;
283 	u_int16_t lport = 0;
284 	int wild = 0;
285 	void *laddr = &zeroin46_addr;
286 	int error;
287 
288 	if (inp->inp_lport)
289 		return (EINVAL);
290 
291 	if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0 &&
292 	    ((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 ||
293 	     (so->so_options & SO_ACCEPTCONN) == 0))
294 		wild = INPLOOKUP_WILDCARD;
295 
296 	switch (sotopf(so)) {
297 #ifdef INET6
298 	case PF_INET6:
299 		if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_laddr6))
300 			return (EINVAL);
301 		wild |= INPLOOKUP_IPV6;
302 
303 		if (nam) {
304 			struct sockaddr_in6 *sin6;
305 
306 			if ((error = in6_nam2sin6(nam, &sin6)))
307 				return (error);
308 			if ((error = in6_pcbaddrisavail(inp, sin6, wild, p)))
309 				return (error);
310 			laddr = &sin6->sin6_addr;
311 			lport = sin6->sin6_port;
312 		}
313 		break;
314 #endif
315 	case PF_INET:
316 		if (inp->inp_laddr.s_addr != INADDR_ANY)
317 			return (EINVAL);
318 
319 		if (nam) {
320 			struct sockaddr_in *sin;
321 
322 			if ((error = in_nam2sin(nam, &sin)))
323 				return (error);
324 			if ((error = in_pcbaddrisavail(inp, sin, wild, p)))
325 				return (error);
326 			laddr = &sin->sin_addr;
327 			lport = sin->sin_port;
328 		}
329 		break;
330 	default:
331 		return (EINVAL);
332 	}
333 
334 	if (lport == 0) {
335 		if ((error = in_pcbpickport(&lport, laddr, wild, inp, p)))
336 			return (error);
337 	} else {
338 		if (in_rootonly(ntohs(lport), so->so_proto->pr_protocol) &&
339 		    suser(p) != 0)
340 			return (EACCES);
341 	}
342 	if (nam) {
343 		switch (sotopf(so)) {
344 #ifdef INET6
345 		case PF_INET6:
346 			inp->inp_laddr6 = *(struct in6_addr *)laddr;
347 			break;
348 #endif
349 		case PF_INET:
350 			inp->inp_laddr = *(struct in_addr *)laddr;
351 			break;
352 		}
353 	}
354 	inp->inp_lport = lport;
355 	in_pcbrehash(inp);
356 	return (0);
357 }
358 
359 int
360 in_pcbaddrisavail(struct inpcb *inp, struct sockaddr_in *sin, int wild,
361     struct proc *p)
362 {
363 	struct socket *so = inp->inp_socket;
364 	struct inpcbtable *table = inp->inp_table;
365 	u_int16_t lport = sin->sin_port;
366 	int reuseport = (so->so_options & SO_REUSEPORT);
367 
368 	if (IN_MULTICAST(sin->sin_addr.s_addr)) {
369 		/*
370 		 * Treat SO_REUSEADDR as SO_REUSEPORT for multicast;
371 		 * allow complete duplication of binding if
372 		 * SO_REUSEPORT is set, or if SO_REUSEADDR is set
373 		 * and a multicast address is bound on both
374 		 * new and duplicated sockets.
375 		 */
376 		if (so->so_options & (SO_REUSEADDR|SO_REUSEPORT))
377 			reuseport = SO_REUSEADDR|SO_REUSEPORT;
378 	} else if (sin->sin_addr.s_addr != INADDR_ANY) {
379 		/*
380 		 * we must check that we are binding to an address we
381 		 * own except when:
382 		 * - SO_BINDANY is set or
383 		 * - we are binding a UDP socket to 255.255.255.255 or
384 		 * - we are binding a UDP socket to one of our broadcast
385 		 *   addresses
386 		 */
387 		if (!ISSET(so->so_options, SO_BINDANY) &&
388 		    !(so->so_type == SOCK_DGRAM &&
389 		    sin->sin_addr.s_addr == INADDR_BROADCAST) &&
390 		    !(so->so_type == SOCK_DGRAM &&
391 		    in_broadcast(sin->sin_addr, inp->inp_rtableid))) {
392 			struct ifaddr *ia;
393 
394 			sin->sin_port = 0;
395 			memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
396 			ia = ifa_ifwithaddr(sintosa(sin), inp->inp_rtableid);
397 			sin->sin_port = lport;
398 
399 			if (ia == NULL)
400 				return (EADDRNOTAVAIL);
401 		}
402 	}
403 	if (lport) {
404 		struct inpcb *t;
405 
406 		if (so->so_euid) {
407 			t = in_pcblookup_local(table, &sin->sin_addr, lport,
408 			    INPLOOKUP_WILDCARD, inp->inp_rtableid);
409 			if (t && (so->so_euid != t->inp_socket->so_euid))
410 				return (EADDRINUSE);
411 		}
412 		t = in_pcblookup_local(table, &sin->sin_addr, lport,
413 		    wild, inp->inp_rtableid);
414 		if (t && (reuseport & t->inp_socket->so_options) == 0)
415 			return (EADDRINUSE);
416 	}
417 
418 	return (0);
419 }
420 
421 int
422 in_pcbpickport(u_int16_t *lport, void *laddr, int wild, struct inpcb *inp,
423     struct proc *p)
424 {
425 	struct socket *so = inp->inp_socket;
426 	struct inpcbtable *table = inp->inp_table;
427 	u_int16_t first, last, lower, higher, candidate, localport;
428 	int count;
429 
430 	if (inp->inp_flags & INP_HIGHPORT) {
431 		first = ipport_hifirstauto;	/* sysctl */
432 		last = ipport_hilastauto;
433 	} else if (inp->inp_flags & INP_LOWPORT) {
434 		if (suser(p))
435 			return (EACCES);
436 		first = IPPORT_RESERVED-1; /* 1023 */
437 		last = 600;		   /* not IPPORT_RESERVED/2 */
438 	} else {
439 		first = ipport_firstauto;	/* sysctl */
440 		last = ipport_lastauto;
441 	}
442 	if (first < last) {
443 		lower = first;
444 		higher = last;
445 	} else {
446 		lower = last;
447 		higher = first;
448 	}
449 
450 	/*
451 	 * Simple check to ensure all ports are not used up causing
452 	 * a deadlock here.
453 	 */
454 
455 	count = higher - lower;
456 	candidate = lower + arc4random_uniform(count);
457 
458 	do {
459 		if (count-- < 0)	/* completely used? */
460 			return (EADDRNOTAVAIL);
461 		++candidate;
462 		if (candidate < lower || candidate > higher)
463 			candidate = lower;
464 		localport = htons(candidate);
465 	} while (in_baddynamic(candidate, so->so_proto->pr_protocol) ||
466 	    in_pcblookup_local(table, laddr, localport, wild,
467 	    inp->inp_rtableid));
468 	*lport = localport;
469 
470 	return (0);
471 }
472 
473 /*
474  * Connect from a socket to a specified address.
475  * Both address and port must be specified in argument sin.
476  * If don't have a local address for this socket yet,
477  * then pick one.
478  */
479 int
480 in_pcbconnect(struct inpcb *inp, struct mbuf *nam)
481 {
482 	struct in_addr *ina = NULL;
483 	struct sockaddr_in *sin;
484 	int error;
485 
486 #ifdef INET6
487 	if (sotopf(inp->inp_socket) == PF_INET6)
488 		return (in6_pcbconnect(inp, nam));
489 	KASSERT((inp->inp_flags & INP_IPV6) == 0);
490 #endif /* INET6 */
491 
492 	if ((error = in_nam2sin(nam, &sin)))
493 		return (error);
494 	if (sin->sin_port == 0)
495 		return (EADDRNOTAVAIL);
496 	error = in_pcbselsrc(&ina, sin, inp);
497 	if (error)
498 		return (error);
499 
500 	if (in_pcbhashlookup(inp->inp_table, sin->sin_addr, sin->sin_port,
501 	    *ina, inp->inp_lport, inp->inp_rtableid) != NULL)
502 		return (EADDRINUSE);
503 
504 	KASSERT(inp->inp_laddr.s_addr == INADDR_ANY || inp->inp_lport);
505 
506 	if (inp->inp_laddr.s_addr == INADDR_ANY) {
507 		if (inp->inp_lport == 0) {
508 			error = in_pcbbind(inp, NULL, curproc);
509 			if (error)
510 				return (error);
511 			if (in_pcbhashlookup(inp->inp_table, sin->sin_addr,
512 			    sin->sin_port, *ina, inp->inp_lport,
513 			    inp->inp_rtableid) != NULL) {
514 				inp->inp_lport = 0;
515 				return (EADDRINUSE);
516 			}
517 		}
518 		inp->inp_laddr = *ina;
519 	}
520 	inp->inp_faddr = sin->sin_addr;
521 	inp->inp_fport = sin->sin_port;
522 	in_pcbrehash(inp);
523 #ifdef IPSEC
524 	{
525 		/* Cause an IPsec SA to be established. */
526 		/* error is just ignored */
527 		ipsp_spd_inp(NULL, AF_INET, 0, &error, IPSP_DIRECTION_OUT,
528 		    NULL, inp, NULL);
529 	}
530 #endif
531 	return (0);
532 }
533 
534 void
535 in_pcbdisconnect(struct inpcb *inp)
536 {
537 	switch (sotopf(inp->inp_socket)) {
538 #ifdef INET6
539 	case PF_INET6:
540 		inp->inp_faddr6 = in6addr_any;
541 		break;
542 #endif
543 	case PF_INET:
544 		inp->inp_faddr.s_addr = INADDR_ANY;
545 		break;
546 	}
547 
548 	inp->inp_fport = 0;
549 	in_pcbrehash(inp);
550 	if (inp->inp_socket->so_state & SS_NOFDREF)
551 		in_pcbdetach(inp);
552 }
553 
554 void
555 in_pcbdetach(struct inpcb *inp)
556 {
557 	struct socket *so;
558 
559 	NET_ASSERT_LOCKED();
560 
561 	mtx_enter(&inp->inp_mtx);
562 	so = inp->inp_socket;
563 	inp->inp_socket = NULL;
564 	mtx_leave(&inp->inp_mtx);
565 
566 	so->so_pcb = NULL;
567 	/*
568 	 * As long as the NET_LOCK() is the default lock for Internet
569 	 * sockets, do not release it to not introduce new sleeping
570 	 * points.
571 	 */
572 	sofree(so, SL_NOUNLOCK);
573 	m_freem(inp->inp_options);
574 	if (inp->inp_route.ro_rt) {
575 		rtfree(inp->inp_route.ro_rt);
576 		inp->inp_route.ro_rt = NULL;
577 	}
578 #ifdef INET6
579 	if (inp->inp_flags & INP_IPV6) {
580 		ip6_freepcbopts(inp->inp_outputopts6);
581 		ip6_freemoptions(inp->inp_moptions6);
582 	} else
583 #endif
584 		ip_freemoptions(inp->inp_moptions);
585 #if NPF > 0
586 	if (inp->inp_pf_sk) {
587 		pf_remove_divert_state(inp->inp_pf_sk);
588 		/* pf_remove_divert_state() may have detached the state */
589 		pf_inp_unlink(inp);
590 	}
591 #endif
592 	mtx_enter(&inpcbtable_mtx);
593 	LIST_REMOVE(inp, inp_lhash);
594 	LIST_REMOVE(inp, inp_hash);
595 	TAILQ_REMOVE(&inp->inp_table->inpt_queue, inp, inp_queue);
596 	inp->inp_table->inpt_count--;
597 	mtx_leave(&inpcbtable_mtx);
598 	in_pcbunref(inp);
599 }
600 
601 struct inpcb *
602 in_pcbref(struct inpcb *inp)
603 {
604 	if (inp != NULL)
605 		refcnt_take(&inp->inp_refcnt);
606 	return inp;
607 }
608 
609 void
610 in_pcbunref(struct inpcb *inp)
611 {
612 	if (refcnt_rele(&inp->inp_refcnt)) {
613 		KASSERT(inp->inp_socket == NULL);
614 		KASSERT((LIST_NEXT(inp, inp_hash) == NULL) ||
615 		    (LIST_NEXT(inp, inp_hash) == _Q_INVALID));
616 		KASSERT((LIST_NEXT(inp, inp_lhash) == NULL) ||
617 		    (LIST_NEXT(inp, inp_lhash) == _Q_INVALID));
618 		KASSERT((TAILQ_NEXT(inp, inp_queue) == NULL) ||
619 		    (TAILQ_NEXT(inp, inp_queue) == _Q_INVALID));
620 		pool_put(&inpcb_pool, inp);
621 	}
622 }
623 
624 void
625 in_setsockaddr(struct inpcb *inp, struct mbuf *nam)
626 {
627 	struct sockaddr_in *sin;
628 
629 	nam->m_len = sizeof(*sin);
630 	sin = mtod(nam, struct sockaddr_in *);
631 	memset(sin, 0, sizeof(*sin));
632 	sin->sin_family = AF_INET;
633 	sin->sin_len = sizeof(*sin);
634 	sin->sin_port = inp->inp_lport;
635 	sin->sin_addr = inp->inp_laddr;
636 }
637 
638 void
639 in_setpeeraddr(struct inpcb *inp, struct mbuf *nam)
640 {
641 	struct sockaddr_in *sin;
642 
643 #ifdef INET6
644 	if (sotopf(inp->inp_socket) == PF_INET6) {
645 		in6_setpeeraddr(inp, nam);
646 		return;
647 	}
648 #endif /* INET6 */
649 
650 	nam->m_len = sizeof(*sin);
651 	sin = mtod(nam, struct sockaddr_in *);
652 	memset(sin, 0, sizeof(*sin));
653 	sin->sin_family = AF_INET;
654 	sin->sin_len = sizeof(*sin);
655 	sin->sin_port = inp->inp_fport;
656 	sin->sin_addr = inp->inp_faddr;
657 }
658 
659 /*
660  * Pass some notification to all connections of a protocol
661  * associated with address dst.  The "usual action" will be
662  * taken, depending on the ctlinput cmd.  The caller must filter any
663  * cmds that are uninteresting (e.g., no error in the map).
664  * Call the protocol specific routine (if any) to report
665  * any errors for each matching socket.
666  */
667 void
668 in_pcbnotifyall(struct inpcbtable *table, struct sockaddr *dst, u_int rtable,
669     int errno, void (*notify)(struct inpcb *, int))
670 {
671 	struct inpcb *inp, *ninp;
672 	struct in_addr faddr;
673 	u_int rdomain;
674 
675 	NET_ASSERT_LOCKED();
676 
677 #ifdef INET6
678 	/*
679 	 * See in6_pcbnotify() for IPv6 codepath.  By the time this
680 	 * gets called, the addresses passed are either definitely IPv4 or
681 	 * IPv6; *_pcbnotify() never gets called with v4-mapped v6 addresses.
682 	 */
683 #endif /* INET6 */
684 
685 	if (dst->sa_family != AF_INET)
686 		return;
687 	faddr = satosin(dst)->sin_addr;
688 	if (faddr.s_addr == INADDR_ANY)
689 		return;
690 
691 	rdomain = rtable_l2(rtable);
692 	KERNEL_LOCK();
693 	mtx_enter(&inpcbtable_mtx);
694 	TAILQ_FOREACH_SAFE(inp, &table->inpt_queue, inp_queue, ninp) {
695 #ifdef INET6
696 		if (inp->inp_flags & INP_IPV6)
697 			continue;
698 #endif
699 		if (inp->inp_faddr.s_addr != faddr.s_addr ||
700 		    rtable_l2(inp->inp_rtableid) != rdomain ||
701 		    inp->inp_socket == NULL) {
702 			continue;
703 		}
704 		/*
705 		 * The notify functions may grab the kernel lock.  Sometimes
706 		 * we already hold the kernel lock when we acquire the pcb
707 		 * mutex.  So do an extra kernel lock before the mutex outside
708 		 * of this loop.  XXXSMP
709 		 */
710 		if (notify)
711 			(*notify)(inp, errno);
712 	}
713 	mtx_leave(&inpcbtable_mtx);
714 	KERNEL_UNLOCK();
715 }
716 
717 /*
718  * Check for alternatives when higher level complains
719  * about service problems.  For now, invalidate cached
720  * routing information.  If the route was created dynamically
721  * (by a redirect), time to try a default gateway again.
722  */
723 void
724 in_losing(struct inpcb *inp)
725 {
726 	struct rtentry *rt = inp->inp_route.ro_rt;
727 
728 	if (rt) {
729 		inp->inp_route.ro_rt = NULL;
730 
731 		if (rt->rt_flags & RTF_DYNAMIC) {
732 			struct ifnet *ifp;
733 
734 			ifp = if_get(rt->rt_ifidx);
735 			/*
736 			 * If the interface is gone, all its attached
737 			 * route entries have been removed from the table,
738 			 * so we're dealing with a stale cache and have
739 			 * nothing to do.
740 			 */
741 			if (ifp != NULL)
742 				rtdeletemsg(rt, ifp, inp->inp_rtableid);
743 			if_put(ifp);
744 		}
745 		/*
746 		 * A new route can be allocated
747 		 * the next time output is attempted.
748 		 * rtfree() needs to be called in anycase because the inp
749 		 * is still holding a reference to rt.
750 		 */
751 		rtfree(rt);
752 	}
753 }
754 
755 /*
756  * After a routing change, flush old routing
757  * and allocate a (hopefully) better one.
758  */
759 void
760 in_rtchange(struct inpcb *inp, int errno)
761 {
762 	if (inp->inp_route.ro_rt) {
763 		rtfree(inp->inp_route.ro_rt);
764 		inp->inp_route.ro_rt = 0;
765 		/*
766 		 * A new route can be allocated the next time
767 		 * output is attempted.
768 		 */
769 	}
770 }
771 
772 struct inpcb *
773 in_pcblookup_local(struct inpcbtable *table, void *laddrp, u_int lport_arg,
774     int flags, u_int rtable)
775 {
776 	struct inpcb *inp, *match = NULL;
777 	int matchwild = 3, wildcard;
778 	u_int16_t lport = lport_arg;
779 	struct in_addr laddr = *(struct in_addr *)laddrp;
780 #ifdef INET6
781 	struct in6_addr *laddr6 = (struct in6_addr *)laddrp;
782 #endif
783 	struct inpcbhead *head;
784 	u_int rdomain;
785 
786 	rdomain = rtable_l2(rtable);
787 	mtx_enter(&inpcbtable_mtx);
788 	head = in_pcblhash(table, rdomain, lport);
789 	LIST_FOREACH(inp, head, inp_lhash) {
790 		if (rtable_l2(inp->inp_rtableid) != rdomain)
791 			continue;
792 		if (inp->inp_lport != lport)
793 			continue;
794 		wildcard = 0;
795 #ifdef INET6
796 		if (ISSET(flags, INPLOOKUP_IPV6)) {
797 			if (!ISSET(inp->inp_flags, INP_IPV6))
798 				continue;
799 
800 			if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6))
801 				wildcard++;
802 
803 			if (!IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6, laddr6)) {
804 				if (IN6_IS_ADDR_UNSPECIFIED(&inp->inp_laddr6) ||
805 				    IN6_IS_ADDR_UNSPECIFIED(laddr6))
806 					wildcard++;
807 				else
808 					continue;
809 			}
810 
811 		} else
812 #endif /* INET6 */
813 		{
814 #ifdef INET6
815 			if (ISSET(inp->inp_flags, INP_IPV6))
816 				continue;
817 #endif /* INET6 */
818 
819 			if (inp->inp_faddr.s_addr != INADDR_ANY)
820 				wildcard++;
821 
822 			if (inp->inp_laddr.s_addr != laddr.s_addr) {
823 				if (inp->inp_laddr.s_addr == INADDR_ANY ||
824 				    laddr.s_addr == INADDR_ANY)
825 					wildcard++;
826 				else
827 					continue;
828 			}
829 
830 		}
831 		if ((!wildcard || (flags & INPLOOKUP_WILDCARD)) &&
832 		    wildcard < matchwild) {
833 			match = inp;
834 			if ((matchwild = wildcard) == 0)
835 				break;
836 		}
837 	}
838 	mtx_leave(&inpcbtable_mtx);
839 
840 	return (match);
841 }
842 
843 struct rtentry *
844 in_pcbrtentry(struct inpcb *inp)
845 {
846 	struct route *ro;
847 
848 	ro = &inp->inp_route;
849 
850 	/* check if route is still valid */
851 	if (!rtisvalid(ro->ro_rt)) {
852 		rtfree(ro->ro_rt);
853 		ro->ro_rt = NULL;
854 	}
855 
856 	/*
857 	 * No route yet, so try to acquire one.
858 	 */
859 	if (ro->ro_rt == NULL) {
860 #ifdef INET6
861 		memset(ro, 0, sizeof(struct route_in6));
862 #else
863 		memset(ro, 0, sizeof(struct route));
864 #endif
865 
866 		switch(sotopf(inp->inp_socket)) {
867 #ifdef INET6
868 		case PF_INET6:
869 			if (IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6))
870 				break;
871 			ro->ro_dst.sa_family = AF_INET6;
872 			ro->ro_dst.sa_len = sizeof(struct sockaddr_in6);
873 			satosin6(&ro->ro_dst)->sin6_addr = inp->inp_faddr6;
874 			ro->ro_tableid = inp->inp_rtableid;
875 			ro->ro_rt = rtalloc_mpath(&ro->ro_dst,
876 			    &inp->inp_laddr6.s6_addr32[0], ro->ro_tableid);
877 			break;
878 #endif /* INET6 */
879 		case PF_INET:
880 			if (inp->inp_faddr.s_addr == INADDR_ANY)
881 				break;
882 			ro->ro_dst.sa_family = AF_INET;
883 			ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
884 			satosin(&ro->ro_dst)->sin_addr = inp->inp_faddr;
885 			ro->ro_tableid = inp->inp_rtableid;
886 			ro->ro_rt = rtalloc_mpath(&ro->ro_dst,
887 			    &inp->inp_laddr.s_addr, ro->ro_tableid);
888 			break;
889 		}
890 	}
891 	return (ro->ro_rt);
892 }
893 
894 /*
895  * Return an IPv4 address, which is the most appropriate for a given
896  * destination.
897  * If necessary, this function lookups the routing table and returns
898  * an entry to the caller for later use.
899  */
900 int
901 in_pcbselsrc(struct in_addr **insrc, struct sockaddr_in *sin,
902     struct inpcb *inp)
903 {
904 	struct ip_moptions *mopts = inp->inp_moptions;
905 	struct route *ro = &inp->inp_route;
906 	struct in_addr *laddr = &inp->inp_laddr;
907 	u_int rtableid = inp->inp_rtableid;
908 
909 	struct sockaddr_in *sin2;
910 	struct in_ifaddr *ia = NULL;
911 
912 	/*
913 	 * If the socket(if any) is already bound, use that bound address
914 	 * unless it is INADDR_ANY or INADDR_BROADCAST.
915 	 */
916 	if (laddr && laddr->s_addr != INADDR_ANY &&
917 	    laddr->s_addr != INADDR_BROADCAST) {
918 		*insrc = laddr;
919 		return (0);
920 	}
921 
922 	/*
923 	 * If the destination address is multicast and an outgoing
924 	 * interface has been set as a multicast option, use the
925 	 * address of that interface as our source address.
926 	 */
927 	if (IN_MULTICAST(sin->sin_addr.s_addr) && mopts != NULL) {
928 		struct ifnet *ifp;
929 
930 		ifp = if_get(mopts->imo_ifidx);
931 		if (ifp != NULL) {
932 			if (ifp->if_rdomain == rtable_l2(rtableid))
933 				IFP_TO_IA(ifp, ia);
934 			if (ia == NULL) {
935 				if_put(ifp);
936 				return (EADDRNOTAVAIL);
937 			}
938 
939 			*insrc = &ia->ia_addr.sin_addr;
940 			if_put(ifp);
941 			return (0);
942 		}
943 	}
944 	/*
945 	 * If route is known or can be allocated now,
946 	 * our src addr is taken from the i/f, else punt.
947 	 */
948 	if (!rtisvalid(ro->ro_rt) || (ro->ro_tableid != rtableid) ||
949 	    (satosin(&ro->ro_dst)->sin_addr.s_addr != sin->sin_addr.s_addr)) {
950 		rtfree(ro->ro_rt);
951 		ro->ro_rt = NULL;
952 	}
953 	if (ro->ro_rt == NULL) {
954 		/* No route yet, so try to acquire one */
955 		ro->ro_dst.sa_family = AF_INET;
956 		ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
957 		satosin(&ro->ro_dst)->sin_addr = sin->sin_addr;
958 		ro->ro_tableid = rtableid;
959 		ro->ro_rt = rtalloc_mpath(&ro->ro_dst, NULL, ro->ro_tableid);
960 
961 		/*
962 		 * It is important to zero out the rest of the
963 		 * struct sockaddr_in when mixing v6 & v4!
964 		 */
965 		sin2 = satosin(&ro->ro_dst);
966 		memset(sin2->sin_zero, 0, sizeof(sin2->sin_zero));
967 	}
968 	/*
969 	 * If we found a route, use the address
970 	 * corresponding to the outgoing interface.
971 	 */
972 	if (ro->ro_rt != NULL)
973 		ia = ifatoia(ro->ro_rt->rt_ifa);
974 
975 	if (ia == NULL)
976 		return (EADDRNOTAVAIL);
977 
978 	*insrc = &ia->ia_addr.sin_addr;
979 	return (0);
980 }
981 
982 void
983 in_pcbrehash(struct inpcb *inp)
984 {
985 	mtx_enter(&inpcbtable_mtx);
986 	in_pcbrehash_locked(inp);
987 	mtx_leave(&inpcbtable_mtx);
988 }
989 
990 void
991 in_pcbrehash_locked(struct inpcb *inp)
992 {
993 	struct inpcbtable *table = inp->inp_table;
994 	struct inpcbhead *head;
995 
996 	NET_ASSERT_LOCKED();
997 	MUTEX_ASSERT_LOCKED(&inpcbtable_mtx);
998 
999 	LIST_REMOVE(inp, inp_lhash);
1000 	head = in_pcblhash(table, inp->inp_rtableid, inp->inp_lport);
1001 	LIST_INSERT_HEAD(head, inp, inp_lhash);
1002 	LIST_REMOVE(inp, inp_hash);
1003 #ifdef INET6
1004 	if (inp->inp_flags & INP_IPV6)
1005 		head = in6_pcbhash(table, rtable_l2(inp->inp_rtableid),
1006 		    &inp->inp_faddr6, inp->inp_fport,
1007 		    &inp->inp_laddr6, inp->inp_lport);
1008 	else
1009 #endif /* INET6 */
1010 		head = in_pcbhash(table, rtable_l2(inp->inp_rtableid),
1011 		    &inp->inp_faddr, inp->inp_fport,
1012 		    &inp->inp_laddr, inp->inp_lport);
1013 	LIST_INSERT_HEAD(head, inp, inp_hash);
1014 }
1015 
1016 int
1017 in_pcbresize(struct inpcbtable *table, int hashsize)
1018 {
1019 	u_long nmask, nlmask;
1020 	int osize;
1021 	void *nhashtbl, *nlhashtbl, *ohashtbl, *olhashtbl;
1022 	struct inpcb *inp;
1023 
1024 	MUTEX_ASSERT_LOCKED(&inpcbtable_mtx);
1025 
1026 	ohashtbl = table->inpt_hashtbl;
1027 	olhashtbl = table->inpt_lhashtbl;
1028 	osize = table->inpt_size;
1029 
1030 	nhashtbl = hashinit(hashsize, M_PCB, M_NOWAIT, &nmask);
1031 	if (nhashtbl == NULL)
1032 		return ENOBUFS;
1033 	nlhashtbl = hashinit(hashsize, M_PCB, M_NOWAIT, &nlmask);
1034 	if (nlhashtbl == NULL) {
1035 		hashfree(nhashtbl, hashsize, M_PCB);
1036 		return ENOBUFS;
1037 	}
1038 	table->inpt_hashtbl = nhashtbl;
1039 	table->inpt_lhashtbl = nlhashtbl;
1040 	table->inpt_mask = nmask;
1041 	table->inpt_lmask = nlmask;
1042 	table->inpt_size = hashsize;
1043 	arc4random_buf(&table->inpt_key, sizeof(table->inpt_key));
1044 	arc4random_buf(&table->inpt_lkey, sizeof(table->inpt_lkey));
1045 
1046 	TAILQ_FOREACH(inp, &table->inpt_queue, inp_queue) {
1047 		in_pcbrehash_locked(inp);
1048 	}
1049 	hashfree(ohashtbl, osize, M_PCB);
1050 	hashfree(olhashtbl, osize, M_PCB);
1051 
1052 	return (0);
1053 }
1054 
1055 #ifdef DIAGNOSTIC
1056 int	in_pcbnotifymiss = 0;
1057 #endif
1058 
1059 /*
1060  * The in(6)_pcbhashlookup functions are used to locate connected sockets
1061  * quickly:
1062  *     faddr.fport <-> laddr.lport
1063  * No wildcard matching is done so that listening sockets are not found.
1064  * If the functions return NULL in(6)_pcblookup_listen can be used to
1065  * find a listening/bound socket that may accept the connection.
1066  * After those two lookups no other are necessary.
1067  */
1068 struct inpcb *
1069 in_pcbhashlookup(struct inpcbtable *table, struct in_addr faddr,
1070     u_int fport_arg, struct in_addr laddr, u_int lport_arg, u_int rtable)
1071 {
1072 	struct inpcbhead *head;
1073 	struct inpcb *inp;
1074 	u_int16_t fport = fport_arg, lport = lport_arg;
1075 	u_int rdomain;
1076 
1077 	rdomain = rtable_l2(rtable);
1078 	mtx_enter(&inpcbtable_mtx);
1079 	head = in_pcbhash(table, rdomain, &faddr, fport, &laddr, lport);
1080 	LIST_FOREACH(inp, head, inp_hash) {
1081 #ifdef INET6
1082 		if (inp->inp_flags & INP_IPV6)
1083 			continue;	/*XXX*/
1084 #endif
1085 		if (inp->inp_faddr.s_addr == faddr.s_addr &&
1086 		    inp->inp_fport == fport && inp->inp_lport == lport &&
1087 		    inp->inp_laddr.s_addr == laddr.s_addr &&
1088 		    rtable_l2(inp->inp_rtableid) == rdomain) {
1089 			/*
1090 			 * Move this PCB to the head of hash chain so that
1091 			 * repeated accesses are quicker.  This is analogous to
1092 			 * the historic single-entry PCB cache.
1093 			 */
1094 			if (inp != LIST_FIRST(head)) {
1095 				LIST_REMOVE(inp, inp_hash);
1096 				LIST_INSERT_HEAD(head, inp, inp_hash);
1097 			}
1098 			break;
1099 		}
1100 	}
1101 	mtx_leave(&inpcbtable_mtx);
1102 #ifdef DIAGNOSTIC
1103 	if (inp == NULL && in_pcbnotifymiss) {
1104 		printf("%s: faddr=%08x fport=%d laddr=%08x lport=%d rdom=%u\n",
1105 		    __func__, ntohl(faddr.s_addr), ntohs(fport),
1106 		    ntohl(laddr.s_addr), ntohs(lport), rdomain);
1107 	}
1108 #endif
1109 	return (inp);
1110 }
1111 
1112 /*
1113  * The in(6)_pcblookup_listen functions are used to locate listening
1114  * sockets quickly.  This are sockets with unspecified foreign address
1115  * and port:
1116  *		*.*     <-> laddr.lport
1117  *		*.*     <->     *.lport
1118  */
1119 struct inpcb *
1120 in_pcblookup_listen(struct inpcbtable *table, struct in_addr laddr,
1121     u_int lport_arg, struct mbuf *m, u_int rtable)
1122 {
1123 	struct inpcbhead *head;
1124 	const struct in_addr *key1, *key2;
1125 	struct inpcb *inp;
1126 	u_int16_t lport = lport_arg;
1127 	u_int rdomain;
1128 
1129 	key1 = &laddr;
1130 	key2 = &zeroin_addr;
1131 #if NPF > 0
1132 	if (m && m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) {
1133 		struct pf_divert *divert;
1134 
1135 		divert = pf_find_divert(m);
1136 		KASSERT(divert != NULL);
1137 		switch (divert->type) {
1138 		case PF_DIVERT_TO:
1139 			key1 = key2 = &divert->addr.v4;
1140 			lport = divert->port;
1141 			break;
1142 		case PF_DIVERT_REPLY:
1143 			return (NULL);
1144 		default:
1145 			panic("%s: unknown divert type %d, mbuf %p, divert %p",
1146 			    __func__, divert->type, m, divert);
1147 		}
1148 	} else if (m && m->m_pkthdr.pf.flags & PF_TAG_TRANSLATE_LOCALHOST) {
1149 		/*
1150 		 * Redirected connections should not be treated the same
1151 		 * as connections directed to 127.0.0.0/8 since localhost
1152 		 * can only be accessed from the host itself.
1153 		 * For example portmap(8) grants more permissions for
1154 		 * connections to the socket bound to 127.0.0.1 than
1155 		 * to the * socket.
1156 		 */
1157 		key1 = &zeroin_addr;
1158 		key2 = &laddr;
1159 	}
1160 #endif
1161 
1162 	rdomain = rtable_l2(rtable);
1163 	mtx_enter(&inpcbtable_mtx);
1164 	head = in_pcbhash(table, rdomain, &zeroin_addr, 0, key1, lport);
1165 	LIST_FOREACH(inp, head, inp_hash) {
1166 #ifdef INET6
1167 		if (inp->inp_flags & INP_IPV6)
1168 			continue;	/*XXX*/
1169 #endif
1170 		if (inp->inp_lport == lport && inp->inp_fport == 0 &&
1171 		    inp->inp_laddr.s_addr == key1->s_addr &&
1172 		    inp->inp_faddr.s_addr == INADDR_ANY &&
1173 		    rtable_l2(inp->inp_rtableid) == rdomain)
1174 			break;
1175 	}
1176 	if (inp == NULL && key1->s_addr != key2->s_addr) {
1177 		head = in_pcbhash(table, rdomain,
1178 		    &zeroin_addr, 0, key2, lport);
1179 		LIST_FOREACH(inp, head, inp_hash) {
1180 #ifdef INET6
1181 			if (inp->inp_flags & INP_IPV6)
1182 				continue;	/*XXX*/
1183 #endif
1184 			if (inp->inp_lport == lport && inp->inp_fport == 0 &&
1185 			    inp->inp_laddr.s_addr == key2->s_addr &&
1186 			    inp->inp_faddr.s_addr == INADDR_ANY &&
1187 			    rtable_l2(inp->inp_rtableid) == rdomain)
1188 				break;
1189 		}
1190 	}
1191 	/*
1192 	 * Move this PCB to the head of hash chain so that
1193 	 * repeated accesses are quicker.  This is analogous to
1194 	 * the historic single-entry PCB cache.
1195 	 */
1196 	if (inp != NULL && inp != LIST_FIRST(head)) {
1197 		LIST_REMOVE(inp, inp_hash);
1198 		LIST_INSERT_HEAD(head, inp, inp_hash);
1199 	}
1200 	mtx_leave(&inpcbtable_mtx);
1201 #ifdef DIAGNOSTIC
1202 	if (inp == NULL && in_pcbnotifymiss) {
1203 		printf("%s: laddr=%08x lport=%d rdom=%u\n",
1204 		    __func__, ntohl(laddr.s_addr), ntohs(lport), rdomain);
1205 	}
1206 #endif
1207 	return (inp);
1208 }
1209