xref: /freebsd/sys/netinet/in_pcb.c (revision 87569f75a91f298c52a71823c04d41cf53c88889)
1 /*-
2  * Copyright (c) 1982, 1986, 1991, 1993, 1995
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)in_pcb.c	8.4 (Berkeley) 5/24/95
30  * $FreeBSD$
31  */
32 
33 #include "opt_ipsec.h"
34 #include "opt_inet6.h"
35 #include "opt_mac.h"
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/mac.h>
40 #include <sys/malloc.h>
41 #include <sys/mbuf.h>
42 #include <sys/domain.h>
43 #include <sys/protosw.h>
44 #include <sys/socket.h>
45 #include <sys/socketvar.h>
46 #include <sys/proc.h>
47 #include <sys/jail.h>
48 #include <sys/kernel.h>
49 #include <sys/sysctl.h>
50 
51 #include <vm/uma.h>
52 
53 #include <net/if.h>
54 #include <net/if_types.h>
55 #include <net/route.h>
56 
57 #include <netinet/in.h>
58 #include <netinet/in_pcb.h>
59 #include <netinet/in_var.h>
60 #include <netinet/ip_var.h>
61 #include <netinet/tcp_var.h>
62 #include <netinet/udp.h>
63 #include <netinet/udp_var.h>
64 #ifdef INET6
65 #include <netinet/ip6.h>
66 #include <netinet6/ip6_var.h>
67 #endif /* INET6 */
68 
69 #ifdef IPSEC
70 #include <netinet6/ipsec.h>
71 #include <netkey/key.h>
72 #endif /* IPSEC */
73 
74 #ifdef FAST_IPSEC
75 #if defined(IPSEC) || defined(IPSEC_ESP)
76 #error "Bad idea: don't compile with both IPSEC and FAST_IPSEC!"
77 #endif
78 
79 #include <netipsec/ipsec.h>
80 #include <netipsec/key.h>
81 #endif /* FAST_IPSEC */
82 
83 /*
84  * These configure the range of local port addresses assigned to
85  * "unspecified" outgoing connections/packets/whatever.
86  */
87 int	ipport_lowfirstauto  = IPPORT_RESERVED - 1;	/* 1023 */
88 int	ipport_lowlastauto = IPPORT_RESERVEDSTART;	/* 600 */
89 int	ipport_firstauto = IPPORT_HIFIRSTAUTO;		/* 49152 */
90 int	ipport_lastauto  = IPPORT_HILASTAUTO;		/* 65535 */
91 int	ipport_hifirstauto = IPPORT_HIFIRSTAUTO;	/* 49152 */
92 int	ipport_hilastauto  = IPPORT_HILASTAUTO;		/* 65535 */
93 
94 /*
95  * Reserved ports accessible only to root. There are significant
96  * security considerations that must be accounted for when changing these,
97  * but the security benefits can be great. Please be careful.
98  */
99 int	ipport_reservedhigh = IPPORT_RESERVED - 1;	/* 1023 */
100 int	ipport_reservedlow = 0;
101 
102 /* Variables dealing with random ephemeral port allocation. */
103 int	ipport_randomized = 1;	/* user controlled via sysctl */
104 int	ipport_randomcps = 10;	/* user controlled via sysctl */
105 int	ipport_randomtime = 45;	/* user controlled via sysctl */
106 int	ipport_stoprandom = 0;	/* toggled by ipport_tick */
107 int	ipport_tcpallocs;
108 int	ipport_tcplastcount;
109 
110 #define RANGECHK(var, min, max) \
111 	if ((var) < (min)) { (var) = (min); } \
112 	else if ((var) > (max)) { (var) = (max); }
113 
114 static int
115 sysctl_net_ipport_check(SYSCTL_HANDLER_ARGS)
116 {
117 	int error;
118 
119 	error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
120 	if (error == 0) {
121 		RANGECHK(ipport_lowfirstauto, 1, IPPORT_RESERVED - 1);
122 		RANGECHK(ipport_lowlastauto, 1, IPPORT_RESERVED - 1);
123 		RANGECHK(ipport_firstauto, IPPORT_RESERVED, IPPORT_MAX);
124 		RANGECHK(ipport_lastauto, IPPORT_RESERVED, IPPORT_MAX);
125 		RANGECHK(ipport_hifirstauto, IPPORT_RESERVED, IPPORT_MAX);
126 		RANGECHK(ipport_hilastauto, IPPORT_RESERVED, IPPORT_MAX);
127 	}
128 	return (error);
129 }
130 
131 #undef RANGECHK
132 
133 SYSCTL_NODE(_net_inet_ip, IPPROTO_IP, portrange, CTLFLAG_RW, 0, "IP Ports");
134 
135 SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, lowfirst, CTLTYPE_INT|CTLFLAG_RW,
136 	   &ipport_lowfirstauto, 0, &sysctl_net_ipport_check, "I", "");
137 SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, lowlast, CTLTYPE_INT|CTLFLAG_RW,
138 	   &ipport_lowlastauto, 0, &sysctl_net_ipport_check, "I", "");
139 SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, first, CTLTYPE_INT|CTLFLAG_RW,
140 	   &ipport_firstauto, 0, &sysctl_net_ipport_check, "I", "");
141 SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, last, CTLTYPE_INT|CTLFLAG_RW,
142 	   &ipport_lastauto, 0, &sysctl_net_ipport_check, "I", "");
143 SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, hifirst, CTLTYPE_INT|CTLFLAG_RW,
144 	   &ipport_hifirstauto, 0, &sysctl_net_ipport_check, "I", "");
145 SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, hilast, CTLTYPE_INT|CTLFLAG_RW,
146 	   &ipport_hilastauto, 0, &sysctl_net_ipport_check, "I", "");
147 SYSCTL_INT(_net_inet_ip_portrange, OID_AUTO, reservedhigh,
148 	   CTLFLAG_RW|CTLFLAG_SECURE, &ipport_reservedhigh, 0, "");
149 SYSCTL_INT(_net_inet_ip_portrange, OID_AUTO, reservedlow,
150 	   CTLFLAG_RW|CTLFLAG_SECURE, &ipport_reservedlow, 0, "");
151 SYSCTL_INT(_net_inet_ip_portrange, OID_AUTO, randomized, CTLFLAG_RW,
152 	   &ipport_randomized, 0, "Enable random port allocation");
153 SYSCTL_INT(_net_inet_ip_portrange, OID_AUTO, randomcps, CTLFLAG_RW,
154 	   &ipport_randomcps, 0, "Maximum number of random port "
155 	   "allocations before switching to a sequental one");
156 SYSCTL_INT(_net_inet_ip_portrange, OID_AUTO, randomtime, CTLFLAG_RW,
157 	   &ipport_randomtime, 0, "Minimum time to keep sequental port "
158 	   "allocation before switching to a random one");
159 
160 /*
161  * in_pcb.c: manage the Protocol Control Blocks.
162  *
163  * NOTE: It is assumed that most of these functions will be called with
164  * the pcbinfo lock held, and often, the inpcb lock held, as these utility
165  * functions often modify hash chains or addresses in pcbs.
166  */
167 
168 /*
169  * Allocate a PCB and associate it with the socket.
170  */
171 int
172 in_pcballoc(struct socket *so, struct inpcbinfo *pcbinfo, const char *type)
173 {
174 	struct inpcb *inp;
175 	int error;
176 
177 	INP_INFO_WLOCK_ASSERT(pcbinfo);
178 	error = 0;
179 	inp = uma_zalloc(pcbinfo->ipi_zone, M_NOWAIT | M_ZERO);
180 	if (inp == NULL)
181 		return (ENOBUFS);
182 	inp->inp_gencnt = ++pcbinfo->ipi_gencnt;
183 	inp->inp_pcbinfo = pcbinfo;
184 	inp->inp_socket = so;
185 #ifdef MAC
186 	error = mac_init_inpcb(inp, M_NOWAIT);
187 	if (error != 0)
188 		goto out;
189 	SOCK_LOCK(so);
190 	mac_create_inpcb_from_socket(so, inp);
191 	SOCK_UNLOCK(so);
192 #endif
193 #if defined(IPSEC) || defined(FAST_IPSEC)
194 #ifdef FAST_IPSEC
195 	error = ipsec_init_policy(so, &inp->inp_sp);
196 #else
197 	error = ipsec_init_pcbpolicy(so, &inp->inp_sp);
198 #endif
199 	if (error != 0)
200 		goto out;
201 #endif /*IPSEC*/
202 #if defined(INET6)
203 	if (INP_SOCKAF(so) == AF_INET6) {
204 		inp->inp_vflag |= INP_IPV6PROTO;
205 		if (ip6_v6only)
206 			inp->inp_flags |= IN6P_IPV6_V6ONLY;
207 	}
208 #endif
209 	LIST_INSERT_HEAD(pcbinfo->listhead, inp, inp_list);
210 	pcbinfo->ipi_count++;
211 	so->so_pcb = (caddr_t)inp;
212 	INP_LOCK_INIT(inp, "inp", type);
213 #ifdef INET6
214 	if (ip6_auto_flowlabel)
215 		inp->inp_flags |= IN6P_AUTOFLOWLABEL;
216 #endif
217 #if defined(IPSEC) || defined(FAST_IPSEC) || defined(MAC)
218 out:
219 	if (error != 0)
220 		uma_zfree(pcbinfo->ipi_zone, inp);
221 #endif
222 	return (error);
223 }
224 
225 int
226 in_pcbbind(struct inpcb *inp, struct sockaddr *nam, struct ucred *cred)
227 {
228 	int anonport, error;
229 
230 	INP_INFO_WLOCK_ASSERT(inp->inp_pcbinfo);
231 	INP_LOCK_ASSERT(inp);
232 
233 	if (inp->inp_lport != 0 || inp->inp_laddr.s_addr != INADDR_ANY)
234 		return (EINVAL);
235 	anonport = inp->inp_lport == 0 && (nam == NULL ||
236 	    ((struct sockaddr_in *)nam)->sin_port == 0);
237 	error = in_pcbbind_setup(inp, nam, &inp->inp_laddr.s_addr,
238 	    &inp->inp_lport, cred);
239 	if (error)
240 		return (error);
241 	if (in_pcbinshash(inp) != 0) {
242 		inp->inp_laddr.s_addr = INADDR_ANY;
243 		inp->inp_lport = 0;
244 		return (EAGAIN);
245 	}
246 	if (anonport)
247 		inp->inp_flags |= INP_ANONPORT;
248 	return (0);
249 }
250 
251 /*
252  * Set up a bind operation on a PCB, performing port allocation
253  * as required, but do not actually modify the PCB. Callers can
254  * either complete the bind by setting inp_laddr/inp_lport and
255  * calling in_pcbinshash(), or they can just use the resulting
256  * port and address to authorise the sending of a once-off packet.
257  *
258  * On error, the values of *laddrp and *lportp are not changed.
259  */
260 int
261 in_pcbbind_setup(struct inpcb *inp, struct sockaddr *nam, in_addr_t *laddrp,
262     u_short *lportp, struct ucred *cred)
263 {
264 	struct socket *so = inp->inp_socket;
265 	unsigned short *lastport;
266 	struct sockaddr_in *sin;
267 	struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
268 	struct in_addr laddr;
269 	u_short lport = 0;
270 	int wild = 0, reuseport = (so->so_options & SO_REUSEPORT);
271 	int error, prison = 0;
272 	int dorandom;
273 
274 	INP_INFO_WLOCK_ASSERT(pcbinfo);
275 	INP_LOCK_ASSERT(inp);
276 
277 	if (TAILQ_EMPTY(&in_ifaddrhead)) /* XXX broken! */
278 		return (EADDRNOTAVAIL);
279 	laddr.s_addr = *laddrp;
280 	if (nam != NULL && laddr.s_addr != INADDR_ANY)
281 		return (EINVAL);
282 	if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0)
283 		wild = 1;
284 	if (nam) {
285 		sin = (struct sockaddr_in *)nam;
286 		if (nam->sa_len != sizeof (*sin))
287 			return (EINVAL);
288 #ifdef notdef
289 		/*
290 		 * We should check the family, but old programs
291 		 * incorrectly fail to initialize it.
292 		 */
293 		if (sin->sin_family != AF_INET)
294 			return (EAFNOSUPPORT);
295 #endif
296 		if (sin->sin_addr.s_addr != INADDR_ANY)
297 			if (prison_ip(cred, 0, &sin->sin_addr.s_addr))
298 				return(EINVAL);
299 		if (sin->sin_port != *lportp) {
300 			/* Don't allow the port to change. */
301 			if (*lportp != 0)
302 				return (EINVAL);
303 			lport = sin->sin_port;
304 		}
305 		/* NB: lport is left as 0 if the port isn't being changed. */
306 		if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr))) {
307 			/*
308 			 * Treat SO_REUSEADDR as SO_REUSEPORT for multicast;
309 			 * allow complete duplication of binding if
310 			 * SO_REUSEPORT is set, or if SO_REUSEADDR is set
311 			 * and a multicast address is bound on both
312 			 * new and duplicated sockets.
313 			 */
314 			if (so->so_options & SO_REUSEADDR)
315 				reuseport = SO_REUSEADDR|SO_REUSEPORT;
316 		} else if (sin->sin_addr.s_addr != INADDR_ANY) {
317 			sin->sin_port = 0;		/* yech... */
318 			bzero(&sin->sin_zero, sizeof(sin->sin_zero));
319 			if (ifa_ifwithaddr((struct sockaddr *)sin) == 0)
320 				return (EADDRNOTAVAIL);
321 		}
322 		laddr = sin->sin_addr;
323 		if (lport) {
324 			struct inpcb *t;
325 			/* GROSS */
326 			if (ntohs(lport) <= ipport_reservedhigh &&
327 			    ntohs(lport) >= ipport_reservedlow &&
328 			    suser_cred(cred, SUSER_ALLOWJAIL))
329 				return (EACCES);
330 			if (jailed(cred))
331 				prison = 1;
332 			if (so->so_cred->cr_uid != 0 &&
333 			    !IN_MULTICAST(ntohl(sin->sin_addr.s_addr))) {
334 				t = in_pcblookup_local(inp->inp_pcbinfo,
335 				    sin->sin_addr, lport,
336 				    prison ? 0 :  INPLOOKUP_WILDCARD);
337 	/*
338 	 * XXX
339 	 * This entire block sorely needs a rewrite.
340 	 */
341 				if (t &&
342 				    ((t->inp_vflag & INP_TIMEWAIT) == 0) &&
343 				    (so->so_type != SOCK_STREAM ||
344 				     ntohl(t->inp_faddr.s_addr) == INADDR_ANY) &&
345 				    (ntohl(sin->sin_addr.s_addr) != INADDR_ANY ||
346 				     ntohl(t->inp_laddr.s_addr) != INADDR_ANY ||
347 				     (t->inp_socket->so_options &
348 					 SO_REUSEPORT) == 0) &&
349 				    (so->so_cred->cr_uid !=
350 				     t->inp_socket->so_cred->cr_uid))
351 					return (EADDRINUSE);
352 			}
353 			if (prison && prison_ip(cred, 0, &sin->sin_addr.s_addr))
354 				return (EADDRNOTAVAIL);
355 			t = in_pcblookup_local(pcbinfo, sin->sin_addr,
356 			    lport, prison ? 0 : wild);
357 			if (t && (t->inp_vflag & INP_TIMEWAIT)) {
358 				if ((reuseport & intotw(t)->tw_so_options) == 0)
359 					return (EADDRINUSE);
360 			} else
361 			if (t &&
362 			    (reuseport & t->inp_socket->so_options) == 0) {
363 #if defined(INET6)
364 				if (ntohl(sin->sin_addr.s_addr) !=
365 				    INADDR_ANY ||
366 				    ntohl(t->inp_laddr.s_addr) !=
367 				    INADDR_ANY ||
368 				    INP_SOCKAF(so) ==
369 				    INP_SOCKAF(t->inp_socket))
370 #endif /* defined(INET6) */
371 				return (EADDRINUSE);
372 			}
373 		}
374 	}
375 	if (*lportp != 0)
376 		lport = *lportp;
377 	if (lport == 0) {
378 		u_short first, last;
379 		int count;
380 
381 		if (laddr.s_addr != INADDR_ANY)
382 			if (prison_ip(cred, 0, &laddr.s_addr))
383 				return (EINVAL);
384 
385 		if (inp->inp_flags & INP_HIGHPORT) {
386 			first = ipport_hifirstauto;	/* sysctl */
387 			last  = ipport_hilastauto;
388 			lastport = &pcbinfo->lasthi;
389 		} else if (inp->inp_flags & INP_LOWPORT) {
390 			if ((error = suser_cred(cred, SUSER_ALLOWJAIL)) != 0)
391 				return error;
392 			first = ipport_lowfirstauto;	/* 1023 */
393 			last  = ipport_lowlastauto;	/* 600 */
394 			lastport = &pcbinfo->lastlow;
395 		} else {
396 			first = ipport_firstauto;	/* sysctl */
397 			last  = ipport_lastauto;
398 			lastport = &pcbinfo->lastport;
399 		}
400 		/*
401 		 * For UDP, use random port allocation as long as the user
402 		 * allows it.  For TCP (and as of yet unknown) connections,
403 		 * use random port allocation only if the user allows it AND
404 		 * ipport_tick() allows it.
405 		 */
406 		if (ipport_randomized &&
407 			(!ipport_stoprandom || pcbinfo == &udbinfo))
408 			dorandom = 1;
409 		else
410 			dorandom = 0;
411 		/*
412 		 * It makes no sense to do random port allocation if
413 		 * we have the only port available.
414 		 */
415 		if (first == last)
416 			dorandom = 0;
417 		/* Make sure to not include UDP packets in the count. */
418 		if (pcbinfo != &udbinfo)
419 			ipport_tcpallocs++;
420 		/*
421 		 * Simple check to ensure all ports are not used up causing
422 		 * a deadlock here.
423 		 *
424 		 * We split the two cases (up and down) so that the direction
425 		 * is not being tested on each round of the loop.
426 		 */
427 		if (first > last) {
428 			/*
429 			 * counting down
430 			 */
431 			if (dorandom)
432 				*lastport = first -
433 					    (arc4random() % (first - last));
434 			count = first - last;
435 
436 			do {
437 				if (count-- < 0)	/* completely used? */
438 					return (EADDRNOTAVAIL);
439 				--*lastport;
440 				if (*lastport > first || *lastport < last)
441 					*lastport = first;
442 				lport = htons(*lastport);
443 			} while (in_pcblookup_local(pcbinfo, laddr, lport,
444 			    wild));
445 		} else {
446 			/*
447 			 * counting up
448 			 */
449 			if (dorandom)
450 				*lastport = first +
451 					    (arc4random() % (last - first));
452 			count = last - first;
453 
454 			do {
455 				if (count-- < 0)	/* completely used? */
456 					return (EADDRNOTAVAIL);
457 				++*lastport;
458 				if (*lastport < first || *lastport > last)
459 					*lastport = first;
460 				lport = htons(*lastport);
461 			} while (in_pcblookup_local(pcbinfo, laddr, lport,
462 			    wild));
463 		}
464 	}
465 	if (prison_ip(cred, 0, &laddr.s_addr))
466 		return (EINVAL);
467 	*laddrp = laddr.s_addr;
468 	*lportp = lport;
469 	return (0);
470 }
471 
472 /*
473  * Connect from a socket to a specified address.
474  * Both address and port must be specified in argument sin.
475  * If don't have a local address for this socket yet,
476  * then pick one.
477  */
478 int
479 in_pcbconnect(struct inpcb *inp, struct sockaddr *nam, struct ucred *cred)
480 {
481 	u_short lport, fport;
482 	in_addr_t laddr, faddr;
483 	int anonport, error;
484 
485 	INP_INFO_WLOCK_ASSERT(inp->inp_pcbinfo);
486 	INP_LOCK_ASSERT(inp);
487 
488 	lport = inp->inp_lport;
489 	laddr = inp->inp_laddr.s_addr;
490 	anonport = (lport == 0);
491 	error = in_pcbconnect_setup(inp, nam, &laddr, &lport, &faddr, &fport,
492 	    NULL, cred);
493 	if (error)
494 		return (error);
495 
496 	/* Do the initial binding of the local address if required. */
497 	if (inp->inp_laddr.s_addr == INADDR_ANY && inp->inp_lport == 0) {
498 		inp->inp_lport = lport;
499 		inp->inp_laddr.s_addr = laddr;
500 		if (in_pcbinshash(inp) != 0) {
501 			inp->inp_laddr.s_addr = INADDR_ANY;
502 			inp->inp_lport = 0;
503 			return (EAGAIN);
504 		}
505 	}
506 
507 	/* Commit the remaining changes. */
508 	inp->inp_lport = lport;
509 	inp->inp_laddr.s_addr = laddr;
510 	inp->inp_faddr.s_addr = faddr;
511 	inp->inp_fport = fport;
512 	in_pcbrehash(inp);
513 #ifdef IPSEC
514 	if (inp->inp_socket->so_type == SOCK_STREAM)
515 		ipsec_pcbconn(inp->inp_sp);
516 #endif
517 	if (anonport)
518 		inp->inp_flags |= INP_ANONPORT;
519 	return (0);
520 }
521 
522 /*
523  * Set up for a connect from a socket to the specified address.
524  * On entry, *laddrp and *lportp should contain the current local
525  * address and port for the PCB; these are updated to the values
526  * that should be placed in inp_laddr and inp_lport to complete
527  * the connect.
528  *
529  * On success, *faddrp and *fportp will be set to the remote address
530  * and port. These are not updated in the error case.
531  *
532  * If the operation fails because the connection already exists,
533  * *oinpp will be set to the PCB of that connection so that the
534  * caller can decide to override it. In all other cases, *oinpp
535  * is set to NULL.
536  */
537 int
538 in_pcbconnect_setup(struct inpcb *inp, struct sockaddr *nam,
539     in_addr_t *laddrp, u_short *lportp, in_addr_t *faddrp, u_short *fportp,
540     struct inpcb **oinpp, struct ucred *cred)
541 {
542 	struct sockaddr_in *sin = (struct sockaddr_in *)nam;
543 	struct in_ifaddr *ia;
544 	struct sockaddr_in sa;
545 	struct ucred *socred;
546 	struct inpcb *oinp;
547 	struct in_addr laddr, faddr;
548 	u_short lport, fport;
549 	int error;
550 
551 	INP_INFO_WLOCK_ASSERT(inp->inp_pcbinfo);
552 	INP_LOCK_ASSERT(inp);
553 
554 	if (oinpp != NULL)
555 		*oinpp = NULL;
556 	if (nam->sa_len != sizeof (*sin))
557 		return (EINVAL);
558 	if (sin->sin_family != AF_INET)
559 		return (EAFNOSUPPORT);
560 	if (sin->sin_port == 0)
561 		return (EADDRNOTAVAIL);
562 	laddr.s_addr = *laddrp;
563 	lport = *lportp;
564 	faddr = sin->sin_addr;
565 	fport = sin->sin_port;
566 	socred = inp->inp_socket->so_cred;
567 	if (laddr.s_addr == INADDR_ANY && jailed(socred)) {
568 		bzero(&sa, sizeof(sa));
569 		sa.sin_addr.s_addr = htonl(prison_getip(socred));
570 		sa.sin_len = sizeof(sa);
571 		sa.sin_family = AF_INET;
572 		error = in_pcbbind_setup(inp, (struct sockaddr *)&sa,
573 		    &laddr.s_addr, &lport, cred);
574 		if (error)
575 			return (error);
576 	}
577 	if (!TAILQ_EMPTY(&in_ifaddrhead)) {
578 		/*
579 		 * If the destination address is INADDR_ANY,
580 		 * use the primary local address.
581 		 * If the supplied address is INADDR_BROADCAST,
582 		 * and the primary interface supports broadcast,
583 		 * choose the broadcast address for that interface.
584 		 */
585 		if (faddr.s_addr == INADDR_ANY)
586 			faddr = IA_SIN(TAILQ_FIRST(&in_ifaddrhead))->sin_addr;
587 		else if (faddr.s_addr == (u_long)INADDR_BROADCAST &&
588 		    (TAILQ_FIRST(&in_ifaddrhead)->ia_ifp->if_flags &
589 		    IFF_BROADCAST))
590 			faddr = satosin(&TAILQ_FIRST(
591 			    &in_ifaddrhead)->ia_broadaddr)->sin_addr;
592 	}
593 	if (laddr.s_addr == INADDR_ANY) {
594 		ia = (struct in_ifaddr *)0;
595 		/*
596 		 * If route is known our src addr is taken from the i/f,
597 		 * else punt.
598 		 *
599 		 * Find out route to destination
600 		 */
601 		if ((inp->inp_socket->so_options & SO_DONTROUTE) == 0)
602 			ia = ip_rtaddr(faddr);
603 		/*
604 		 * If we found a route, use the address corresponding to
605 		 * the outgoing interface.
606 		 *
607 		 * Otherwise assume faddr is reachable on a directly connected
608 		 * network and try to find a corresponding interface to take
609 		 * the source address from.
610 		 */
611 		if (ia == 0) {
612 			bzero(&sa, sizeof(sa));
613 			sa.sin_addr = faddr;
614 			sa.sin_len = sizeof(sa);
615 			sa.sin_family = AF_INET;
616 
617 			ia = ifatoia(ifa_ifwithdstaddr(sintosa(&sa)));
618 			if (ia == 0)
619 				ia = ifatoia(ifa_ifwithnet(sintosa(&sa)));
620 			if (ia == 0)
621 				return (ENETUNREACH);
622 		}
623 		/*
624 		 * If the destination address is multicast and an outgoing
625 		 * interface has been set as a multicast option, use the
626 		 * address of that interface as our source address.
627 		 */
628 		if (IN_MULTICAST(ntohl(faddr.s_addr)) &&
629 		    inp->inp_moptions != NULL) {
630 			struct ip_moptions *imo;
631 			struct ifnet *ifp;
632 
633 			imo = inp->inp_moptions;
634 			if (imo->imo_multicast_ifp != NULL) {
635 				ifp = imo->imo_multicast_ifp;
636 				TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link)
637 					if (ia->ia_ifp == ifp)
638 						break;
639 				if (ia == 0)
640 					return (EADDRNOTAVAIL);
641 			}
642 		}
643 		laddr = ia->ia_addr.sin_addr;
644 	}
645 
646 	oinp = in_pcblookup_hash(inp->inp_pcbinfo, faddr, fport, laddr, lport,
647 	    0, NULL);
648 	if (oinp != NULL) {
649 		if (oinpp != NULL)
650 			*oinpp = oinp;
651 		return (EADDRINUSE);
652 	}
653 	if (lport == 0) {
654 		error = in_pcbbind_setup(inp, NULL, &laddr.s_addr, &lport,
655 		    cred);
656 		if (error)
657 			return (error);
658 	}
659 	*laddrp = laddr.s_addr;
660 	*lportp = lport;
661 	*faddrp = faddr.s_addr;
662 	*fportp = fport;
663 	return (0);
664 }
665 
666 void
667 in_pcbdisconnect(struct inpcb *inp)
668 {
669 
670 	INP_INFO_WLOCK_ASSERT(inp->inp_pcbinfo);
671 	INP_LOCK_ASSERT(inp);
672 
673 	inp->inp_faddr.s_addr = INADDR_ANY;
674 	inp->inp_fport = 0;
675 	in_pcbrehash(inp);
676 #ifdef IPSEC
677 	ipsec_pcbdisconn(inp->inp_sp);
678 #endif
679 	if (inp->inp_socket->so_state & SS_NOFDREF)
680 		in_pcbdetach(inp);
681 }
682 
683 void
684 in_pcbdetach(struct inpcb *inp)
685 {
686 	struct socket *so = inp->inp_socket;
687 	struct inpcbinfo *ipi = inp->inp_pcbinfo;
688 
689 	INP_INFO_WLOCK_ASSERT(ipi);
690 	INP_LOCK_ASSERT(inp);
691 
692 #if defined(IPSEC) || defined(FAST_IPSEC)
693 	ipsec4_delete_pcbpolicy(inp);
694 #endif /*IPSEC*/
695 	inp->inp_gencnt = ++ipi->ipi_gencnt;
696 	in_pcbremlists(inp);
697 	if (so) {
698 		ACCEPT_LOCK();
699 		SOCK_LOCK(so);
700 		so->so_pcb = NULL;
701 		sotryfree(so);
702 	}
703 	if (inp->inp_options)
704 		(void)m_free(inp->inp_options);
705 	ip_freemoptions(inp->inp_moptions);
706 	inp->inp_vflag = 0;
707 	INP_LOCK_DESTROY(inp);
708 #ifdef MAC
709 	mac_destroy_inpcb(inp);
710 #endif
711 	uma_zfree(ipi->ipi_zone, inp);
712 }
713 
714 struct sockaddr *
715 in_sockaddr(in_port_t port, struct in_addr *addr_p)
716 {
717 	struct sockaddr_in *sin;
718 
719 	MALLOC(sin, struct sockaddr_in *, sizeof *sin, M_SONAME,
720 		M_WAITOK | M_ZERO);
721 	sin->sin_family = AF_INET;
722 	sin->sin_len = sizeof(*sin);
723 	sin->sin_addr = *addr_p;
724 	sin->sin_port = port;
725 
726 	return (struct sockaddr *)sin;
727 }
728 
729 /*
730  * The wrapper function will pass down the pcbinfo for this function to lock.
731  * The socket must have a valid
732  * (i.e., non-nil) PCB, but it should be impossible to get an invalid one
733  * except through a kernel programming error, so it is acceptable to panic
734  * (or in this case trap) if the PCB is invalid.  (Actually, we don't trap
735  * because there actually /is/ a programming error somewhere... XXX)
736  */
737 int
738 in_setsockaddr(struct socket *so, struct sockaddr **nam,
739     struct inpcbinfo *pcbinfo)
740 {
741 	struct inpcb *inp;
742 	struct in_addr addr;
743 	in_port_t port;
744 
745 	INP_INFO_RLOCK(pcbinfo);
746 	inp = sotoinpcb(so);
747 	if (!inp) {
748 		INP_INFO_RUNLOCK(pcbinfo);
749 		return ECONNRESET;
750 	}
751 	INP_LOCK(inp);
752 	port = inp->inp_lport;
753 	addr = inp->inp_laddr;
754 	INP_UNLOCK(inp);
755 	INP_INFO_RUNLOCK(pcbinfo);
756 
757 	*nam = in_sockaddr(port, &addr);
758 	return 0;
759 }
760 
761 /*
762  * The wrapper function will pass down the pcbinfo for this function to lock.
763  */
764 int
765 in_setpeeraddr(struct socket *so, struct sockaddr **nam,
766     struct inpcbinfo *pcbinfo)
767 {
768 	struct inpcb *inp;
769 	struct in_addr addr;
770 	in_port_t port;
771 
772 	INP_INFO_RLOCK(pcbinfo);
773 	inp = sotoinpcb(so);
774 	if (!inp) {
775 		INP_INFO_RUNLOCK(pcbinfo);
776 		return ECONNRESET;
777 	}
778 	INP_LOCK(inp);
779 	port = inp->inp_fport;
780 	addr = inp->inp_faddr;
781 	INP_UNLOCK(inp);
782 	INP_INFO_RUNLOCK(pcbinfo);
783 
784 	*nam = in_sockaddr(port, &addr);
785 	return 0;
786 }
787 
788 void
789 in_pcbnotifyall(struct inpcbinfo *pcbinfo, struct in_addr faddr, int errno,
790     struct inpcb *(*notify)(struct inpcb *, int))
791 {
792 	struct inpcb *inp, *ninp;
793 	struct inpcbhead *head;
794 
795 	INP_INFO_WLOCK(pcbinfo);
796 	head = pcbinfo->listhead;
797 	for (inp = LIST_FIRST(head); inp != NULL; inp = ninp) {
798 		INP_LOCK(inp);
799 		ninp = LIST_NEXT(inp, inp_list);
800 #ifdef INET6
801 		if ((inp->inp_vflag & INP_IPV4) == 0) {
802 			INP_UNLOCK(inp);
803 			continue;
804 		}
805 #endif
806 		if (inp->inp_faddr.s_addr != faddr.s_addr ||
807 		    inp->inp_socket == NULL) {
808 			INP_UNLOCK(inp);
809 			continue;
810 		}
811 		if ((*notify)(inp, errno))
812 			INP_UNLOCK(inp);
813 	}
814 	INP_INFO_WUNLOCK(pcbinfo);
815 }
816 
817 void
818 in_pcbpurgeif0(struct inpcbinfo *pcbinfo, struct ifnet *ifp)
819 {
820 	struct inpcb *inp;
821 	struct ip_moptions *imo;
822 	int i, gap;
823 
824 	INP_INFO_RLOCK(pcbinfo);
825 	LIST_FOREACH(inp, pcbinfo->listhead, inp_list) {
826 		INP_LOCK(inp);
827 		imo = inp->inp_moptions;
828 		if ((inp->inp_vflag & INP_IPV4) &&
829 		    imo != NULL) {
830 			/*
831 			 * Unselect the outgoing interface if it is being
832 			 * detached.
833 			 */
834 			if (imo->imo_multicast_ifp == ifp)
835 				imo->imo_multicast_ifp = NULL;
836 
837 			/*
838 			 * Drop multicast group membership if we joined
839 			 * through the interface being detached.
840 			 */
841 			for (i = 0, gap = 0; i < imo->imo_num_memberships;
842 			    i++) {
843 				if (imo->imo_membership[i]->inm_ifp == ifp) {
844 					in_delmulti(imo->imo_membership[i]);
845 					gap++;
846 				} else if (gap != 0)
847 					imo->imo_membership[i - gap] =
848 					    imo->imo_membership[i];
849 			}
850 			imo->imo_num_memberships -= gap;
851 		}
852 		INP_UNLOCK(inp);
853 	}
854 	INP_INFO_RUNLOCK(pcbinfo);
855 }
856 
857 /*
858  * Lookup a PCB based on the local address and port.
859  */
860 #define INP_LOOKUP_MAPPED_PCB_COST	3
861 struct inpcb *
862 in_pcblookup_local(struct inpcbinfo *pcbinfo, struct in_addr laddr,
863     u_int lport_arg, int wild_okay)
864 {
865 	struct inpcb *inp;
866 #ifdef INET6
867 	int matchwild = 3 + INP_LOOKUP_MAPPED_PCB_COST;
868 #else
869 	int matchwild = 3;
870 #endif
871 	int wildcard;
872 	u_short lport = lport_arg;
873 
874 	INP_INFO_WLOCK_ASSERT(pcbinfo);
875 
876 	if (!wild_okay) {
877 		struct inpcbhead *head;
878 		/*
879 		 * Look for an unconnected (wildcard foreign addr) PCB that
880 		 * matches the local address and port we're looking for.
881 		 */
882 		head = &pcbinfo->hashbase[INP_PCBHASH(INADDR_ANY, lport, 0, pcbinfo->hashmask)];
883 		LIST_FOREACH(inp, head, inp_hash) {
884 #ifdef INET6
885 			if ((inp->inp_vflag & INP_IPV4) == 0)
886 				continue;
887 #endif
888 			if (inp->inp_faddr.s_addr == INADDR_ANY &&
889 			    inp->inp_laddr.s_addr == laddr.s_addr &&
890 			    inp->inp_lport == lport) {
891 				/*
892 				 * Found.
893 				 */
894 				return (inp);
895 			}
896 		}
897 		/*
898 		 * Not found.
899 		 */
900 		return (NULL);
901 	} else {
902 		struct inpcbporthead *porthash;
903 		struct inpcbport *phd;
904 		struct inpcb *match = NULL;
905 		/*
906 		 * Best fit PCB lookup.
907 		 *
908 		 * First see if this local port is in use by looking on the
909 		 * port hash list.
910 		 */
911 		retrylookup:
912 		porthash = &pcbinfo->porthashbase[INP_PCBPORTHASH(lport,
913 		    pcbinfo->porthashmask)];
914 		LIST_FOREACH(phd, porthash, phd_hash) {
915 			if (phd->phd_port == lport)
916 				break;
917 		}
918 		if (phd != NULL) {
919 			/*
920 			 * Port is in use by one or more PCBs. Look for best
921 			 * fit.
922 			 */
923 			LIST_FOREACH(inp, &phd->phd_pcblist, inp_portlist) {
924 				wildcard = 0;
925 #ifdef INET6
926 				if ((inp->inp_vflag & INP_IPV4) == 0)
927 					continue;
928 				/*
929 				 * We never select the PCB that has
930 				 * INP_IPV6 flag and is bound to :: if
931 				 * we have another PCB which is bound
932 				 * to 0.0.0.0.  If a PCB has the
933 				 * INP_IPV6 flag, then we set its cost
934 				 * higher than IPv4 only PCBs.
935 				 *
936 				 * Note that the case only happens
937 				 * when a socket is bound to ::, under
938 				 * the condition that the use of the
939 				 * mapped address is allowed.
940 				 */
941 				if ((inp->inp_vflag & INP_IPV6) != 0)
942 					wildcard += INP_LOOKUP_MAPPED_PCB_COST;
943 #endif
944 				/*
945 				 * Clean out old time_wait sockets if they
946 				 * are clogging up needed local ports.
947 				 */
948 				if ((inp->inp_vflag & INP_TIMEWAIT) != 0) {
949 					if (tcp_twrecycleable((struct tcptw *)inp->inp_ppcb)) {
950 						INP_LOCK(inp);
951 						tcp_twclose((struct tcptw *)inp->inp_ppcb, 0);
952 						match = NULL;
953 						goto retrylookup;
954 					}
955 				}
956 				if (inp->inp_faddr.s_addr != INADDR_ANY)
957 					wildcard++;
958 				if (inp->inp_laddr.s_addr != INADDR_ANY) {
959 					if (laddr.s_addr == INADDR_ANY)
960 						wildcard++;
961 					else if (inp->inp_laddr.s_addr != laddr.s_addr)
962 						continue;
963 				} else {
964 					if (laddr.s_addr != INADDR_ANY)
965 						wildcard++;
966 				}
967 				if (wildcard < matchwild) {
968 					match = inp;
969 					matchwild = wildcard;
970 					if (matchwild == 0) {
971 						break;
972 					}
973 				}
974 			}
975 		}
976 		return (match);
977 	}
978 }
979 #undef INP_LOOKUP_MAPPED_PCB_COST
980 
981 /*
982  * Lookup PCB in hash list.
983  */
984 struct inpcb *
985 in_pcblookup_hash(struct inpcbinfo *pcbinfo, struct in_addr faddr,
986     u_int fport_arg, struct in_addr laddr, u_int lport_arg, int wildcard,
987     struct ifnet *ifp)
988 {
989 	struct inpcbhead *head;
990 	struct inpcb *inp;
991 	u_short fport = fport_arg, lport = lport_arg;
992 
993 	INP_INFO_RLOCK_ASSERT(pcbinfo);
994 	/*
995 	 * First look for an exact match.
996 	 */
997 	head = &pcbinfo->hashbase[INP_PCBHASH(faddr.s_addr, lport, fport, pcbinfo->hashmask)];
998 	LIST_FOREACH(inp, head, inp_hash) {
999 #ifdef INET6
1000 		if ((inp->inp_vflag & INP_IPV4) == 0)
1001 			continue;
1002 #endif
1003 		if (inp->inp_faddr.s_addr == faddr.s_addr &&
1004 		    inp->inp_laddr.s_addr == laddr.s_addr &&
1005 		    inp->inp_fport == fport &&
1006 		    inp->inp_lport == lport) {
1007 			/*
1008 			 * Found.
1009 			 */
1010 			return (inp);
1011 		}
1012 	}
1013 	if (wildcard) {
1014 		struct inpcb *local_wild = NULL;
1015 #if defined(INET6)
1016 		struct inpcb *local_wild_mapped = NULL;
1017 #endif /* defined(INET6) */
1018 
1019 		head = &pcbinfo->hashbase[INP_PCBHASH(INADDR_ANY, lport, 0, pcbinfo->hashmask)];
1020 		LIST_FOREACH(inp, head, inp_hash) {
1021 #ifdef INET6
1022 			if ((inp->inp_vflag & INP_IPV4) == 0)
1023 				continue;
1024 #endif
1025 			if (inp->inp_faddr.s_addr == INADDR_ANY &&
1026 			    inp->inp_lport == lport) {
1027 				if (ifp && ifp->if_type == IFT_FAITH &&
1028 				    (inp->inp_flags & INP_FAITH) == 0)
1029 					continue;
1030 				if (inp->inp_laddr.s_addr == laddr.s_addr)
1031 					return (inp);
1032 				else if (inp->inp_laddr.s_addr == INADDR_ANY) {
1033 #if defined(INET6)
1034 					if (INP_CHECK_SOCKAF(inp->inp_socket,
1035 							     AF_INET6))
1036 						local_wild_mapped = inp;
1037 					else
1038 #endif /* defined(INET6) */
1039 					local_wild = inp;
1040 				}
1041 			}
1042 		}
1043 #if defined(INET6)
1044 		if (local_wild == NULL)
1045 			return (local_wild_mapped);
1046 #endif /* defined(INET6) */
1047 		return (local_wild);
1048 	}
1049 
1050 	/*
1051 	 * Not found.
1052 	 */
1053 	return (NULL);
1054 }
1055 
1056 /*
1057  * Insert PCB onto various hash lists.
1058  */
1059 int
1060 in_pcbinshash(struct inpcb *inp)
1061 {
1062 	struct inpcbhead *pcbhash;
1063 	struct inpcbporthead *pcbporthash;
1064 	struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
1065 	struct inpcbport *phd;
1066 	u_int32_t hashkey_faddr;
1067 
1068 	INP_INFO_WLOCK_ASSERT(pcbinfo);
1069 #ifdef INET6
1070 	if (inp->inp_vflag & INP_IPV6)
1071 		hashkey_faddr = inp->in6p_faddr.s6_addr32[3] /* XXX */;
1072 	else
1073 #endif /* INET6 */
1074 	hashkey_faddr = inp->inp_faddr.s_addr;
1075 
1076 	pcbhash = &pcbinfo->hashbase[INP_PCBHASH(hashkey_faddr,
1077 		 inp->inp_lport, inp->inp_fport, pcbinfo->hashmask)];
1078 
1079 	pcbporthash = &pcbinfo->porthashbase[INP_PCBPORTHASH(inp->inp_lport,
1080 	    pcbinfo->porthashmask)];
1081 
1082 	/*
1083 	 * Go through port list and look for a head for this lport.
1084 	 */
1085 	LIST_FOREACH(phd, pcbporthash, phd_hash) {
1086 		if (phd->phd_port == inp->inp_lport)
1087 			break;
1088 	}
1089 	/*
1090 	 * If none exists, malloc one and tack it on.
1091 	 */
1092 	if (phd == NULL) {
1093 		MALLOC(phd, struct inpcbport *, sizeof(struct inpcbport), M_PCB, M_NOWAIT);
1094 		if (phd == NULL) {
1095 			return (ENOBUFS); /* XXX */
1096 		}
1097 		phd->phd_port = inp->inp_lport;
1098 		LIST_INIT(&phd->phd_pcblist);
1099 		LIST_INSERT_HEAD(pcbporthash, phd, phd_hash);
1100 	}
1101 	inp->inp_phd = phd;
1102 	LIST_INSERT_HEAD(&phd->phd_pcblist, inp, inp_portlist);
1103 	LIST_INSERT_HEAD(pcbhash, inp, inp_hash);
1104 	return (0);
1105 }
1106 
1107 /*
1108  * Move PCB to the proper hash bucket when { faddr, fport } have  been
1109  * changed. NOTE: This does not handle the case of the lport changing (the
1110  * hashed port list would have to be updated as well), so the lport must
1111  * not change after in_pcbinshash() has been called.
1112  */
1113 void
1114 in_pcbrehash(struct inpcb *inp)
1115 {
1116 	struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
1117 	struct inpcbhead *head;
1118 	u_int32_t hashkey_faddr;
1119 
1120 	INP_INFO_WLOCK_ASSERT(pcbinfo);
1121 	INP_LOCK_ASSERT(inp);
1122 #ifdef INET6
1123 	if (inp->inp_vflag & INP_IPV6)
1124 		hashkey_faddr = inp->in6p_faddr.s6_addr32[3] /* XXX */;
1125 	else
1126 #endif /* INET6 */
1127 	hashkey_faddr = inp->inp_faddr.s_addr;
1128 
1129 	head = &pcbinfo->hashbase[INP_PCBHASH(hashkey_faddr,
1130 		inp->inp_lport, inp->inp_fport, pcbinfo->hashmask)];
1131 
1132 	LIST_REMOVE(inp, inp_hash);
1133 	LIST_INSERT_HEAD(head, inp, inp_hash);
1134 }
1135 
1136 /*
1137  * Remove PCB from various lists.
1138  */
1139 void
1140 in_pcbremlists(struct inpcb *inp)
1141 {
1142 	struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
1143 
1144 	INP_INFO_WLOCK_ASSERT(pcbinfo);
1145 	INP_LOCK_ASSERT(inp);
1146 
1147 	inp->inp_gencnt = ++pcbinfo->ipi_gencnt;
1148 	if (inp->inp_lport) {
1149 		struct inpcbport *phd = inp->inp_phd;
1150 
1151 		LIST_REMOVE(inp, inp_hash);
1152 		LIST_REMOVE(inp, inp_portlist);
1153 		if (LIST_FIRST(&phd->phd_pcblist) == NULL) {
1154 			LIST_REMOVE(phd, phd_hash);
1155 			free(phd, M_PCB);
1156 		}
1157 	}
1158 	LIST_REMOVE(inp, inp_list);
1159 	pcbinfo->ipi_count--;
1160 }
1161 
1162 /*
1163  * A set label operation has occurred at the socket layer, propagate the
1164  * label change into the in_pcb for the socket.
1165  */
1166 void
1167 in_pcbsosetlabel(struct socket *so)
1168 {
1169 #ifdef MAC
1170 	struct inpcb *inp;
1171 
1172 	inp = (struct inpcb *)so->so_pcb;
1173 	INP_LOCK(inp);
1174 	SOCK_LOCK(so);
1175 	mac_inpcb_sosetlabel(so, inp);
1176 	SOCK_UNLOCK(so);
1177 	INP_UNLOCK(inp);
1178 #endif
1179 }
1180 
1181 /*
1182  * ipport_tick runs once per second, determining if random port
1183  * allocation should be continued.  If more than ipport_randomcps
1184  * ports have been allocated in the last second, then we return to
1185  * sequential port allocation. We return to random allocation only
1186  * once we drop below ipport_randomcps for at least ipport_randomtime
1187  * seconds.
1188  */
1189 
1190 void
1191 ipport_tick(void *xtp)
1192 {
1193 	if (ipport_tcpallocs > ipport_tcplastcount + ipport_randomcps) {
1194 		ipport_stoprandom = ipport_randomtime;
1195 	} else {
1196 		if (ipport_stoprandom > 0)
1197 			ipport_stoprandom--;
1198 	}
1199 	ipport_tcplastcount = ipport_tcpallocs;
1200 	callout_reset(&ipport_tick_callout, hz, ipport_tick, NULL);
1201 }
1202