xref: /dragonfly/sys/kern/uipc_socket2.c (revision 2038fb68)
1 /*
2  * Copyright (c) 2005 Jeffrey M. Hsu.  All rights reserved.
3  * Copyright (c) 1982, 1986, 1988, 1990, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *	This product includes software developed by the University of
17  *	California, Berkeley and its contributors.
18  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)uipc_socket2.c	8.1 (Berkeley) 6/10/93
35  * $FreeBSD: src/sys/kern/uipc_socket2.c,v 1.55.2.17 2002/08/31 19:04:55 dwmalone Exp $
36  * $DragonFly: src/sys/kern/uipc_socket2.c,v 1.33 2008/09/02 16:17:52 dillon Exp $
37  */
38 
39 #include "opt_param.h"
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/domain.h>
43 #include <sys/file.h>	/* for maxfiles */
44 #include <sys/kernel.h>
45 #include <sys/proc.h>
46 #include <sys/malloc.h>
47 #include <sys/mbuf.h>
48 #include <sys/protosw.h>
49 #include <sys/resourcevar.h>
50 #include <sys/stat.h>
51 #include <sys/socket.h>
52 #include <sys/socketvar.h>
53 #include <sys/signalvar.h>
54 #include <sys/sysctl.h>
55 #include <sys/aio.h> /* for aio_swake proto */
56 #include <sys/event.h>
57 
58 #include <sys/thread2.h>
59 #include <sys/msgport2.h>
60 
61 int	maxsockets;
62 
63 /*
64  * Primitive routines for operating on sockets and socket buffers
65  */
66 
67 u_long	sb_max = SB_MAX;
68 u_long	sb_max_adj =
69     SB_MAX * MCLBYTES / (MSIZE + MCLBYTES); /* adjusted sb_max */
70 
71 static	u_long sb_efficiency = 8;	/* parameter for sbreserve() */
72 
73 /************************************************************************
74  * signalsockbuf procedures						*
75  ************************************************************************/
76 
77 /*
78  * Wait for data to arrive at/drain from a socket buffer.
79  */
80 int
81 ssb_wait(struct signalsockbuf *ssb)
82 {
83 
84 	ssb->ssb_flags |= SSB_WAIT;
85 	return (tsleep((caddr_t)&ssb->ssb_cc,
86 			((ssb->ssb_flags & SSB_NOINTR) ? 0 : PCATCH),
87 			"sbwait",
88 			ssb->ssb_timeo));
89 }
90 
91 /*
92  * Lock a sockbuf already known to be locked;
93  * return any error returned from sleep (EINTR).
94  */
95 int
96 _ssb_lock(struct signalsockbuf *ssb)
97 {
98 	int error;
99 
100 	while (ssb->ssb_flags & SSB_LOCK) {
101 		ssb->ssb_flags |= SSB_WANT;
102 		error = tsleep((caddr_t)&ssb->ssb_flags,
103 			    ((ssb->ssb_flags & SSB_NOINTR) ? 0 : PCATCH),
104 			    "sblock", 0);
105 		if (error)
106 			return (error);
107 	}
108 	ssb->ssb_flags |= SSB_LOCK;
109 	return (0);
110 }
111 
112 /*
113  * This does the same for sockbufs.  Note that the xsockbuf structure,
114  * since it is always embedded in a socket, does not include a self
115  * pointer nor a length.  We make this entry point public in case
116  * some other mechanism needs it.
117  */
118 void
119 ssbtoxsockbuf(struct signalsockbuf *ssb, struct xsockbuf *xsb)
120 {
121 	xsb->sb_cc = ssb->ssb_cc;
122 	xsb->sb_hiwat = ssb->ssb_hiwat;
123 	xsb->sb_mbcnt = ssb->ssb_mbcnt;
124 	xsb->sb_mbmax = ssb->ssb_mbmax;
125 	xsb->sb_lowat = ssb->ssb_lowat;
126 	xsb->sb_flags = ssb->ssb_flags;
127 	xsb->sb_timeo = ssb->ssb_timeo;
128 }
129 
130 
131 /************************************************************************
132  * Procedures which manipulate socket state flags, wakeups, etc.	*
133  ************************************************************************
134  *
135  * Normal sequence from the active (originating) side is that
136  * soisconnecting() is called during processing of connect() call, resulting
137  * in an eventual call to soisconnected() if/when the connection is
138  * established.  When the connection is torn down soisdisconnecting() is
139  * called during processing of disconnect() call, and soisdisconnected() is
140  * called when the connection to the peer is totally severed.
141  *
142  * The semantics of these routines are such that connectionless protocols
143  * can call soisconnected() and soisdisconnected() only, bypassing the
144  * in-progress calls when setting up a ``connection'' takes no time.
145  *
146  * From the passive side, a socket is created with two queues of sockets:
147  * so_incomp for connections in progress and so_comp for connections
148  * already made and awaiting user acceptance.  As a protocol is preparing
149  * incoming connections, it creates a socket structure queued on so_incomp
150  * by calling sonewconn().  When the connection is established,
151  * soisconnected() is called, and transfers the socket structure to so_comp,
152  * making it available to accept().
153  *
154  * If a socket is closed with sockets on either so_incomp or so_comp, these
155  * sockets are dropped.
156  *
157  * If higher level protocols are implemented in the kernel, the wakeups
158  * done here will sometimes cause software-interrupt process scheduling.
159  */
160 
161 void
162 soisconnecting(struct socket *so)
163 {
164 	so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
165 	so->so_state |= SS_ISCONNECTING;
166 }
167 
168 void
169 soisconnected(struct socket *so)
170 {
171 	struct socket *head = so->so_head;
172 
173 	so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
174 	so->so_state |= SS_ISCONNECTED;
175 	if (head && (so->so_state & SS_INCOMP)) {
176 		if ((so->so_options & SO_ACCEPTFILTER) != 0) {
177 			so->so_upcall = head->so_accf->so_accept_filter->accf_callback;
178 			so->so_upcallarg = head->so_accf->so_accept_filter_arg;
179 			so->so_rcv.ssb_flags |= SSB_UPCALL;
180 			so->so_options &= ~SO_ACCEPTFILTER;
181 			so->so_upcall(so, so->so_upcallarg, 0);
182 			return;
183 		}
184 		TAILQ_REMOVE(&head->so_incomp, so, so_list);
185 		head->so_incqlen--;
186 		so->so_state &= ~SS_INCOMP;
187 		TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
188 		head->so_qlen++;
189 		so->so_state |= SS_COMP;
190 		sorwakeup(head);
191 		wakeup_one(&head->so_timeo);
192 	} else {
193 		wakeup(&so->so_timeo);
194 		sorwakeup(so);
195 		sowwakeup(so);
196 	}
197 }
198 
199 void
200 soisdisconnecting(struct socket *so)
201 {
202 	so->so_state &= ~SS_ISCONNECTING;
203 	so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE);
204 	wakeup((caddr_t)&so->so_timeo);
205 	sowwakeup(so);
206 	sorwakeup(so);
207 }
208 
209 void
210 soisdisconnected(struct socket *so)
211 {
212 	so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
213 	so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED);
214 	wakeup((caddr_t)&so->so_timeo);
215 	sbdrop(&so->so_snd.sb, so->so_snd.ssb_cc);
216 	sowwakeup(so);
217 	sorwakeup(so);
218 }
219 
220 /*
221  * When an attempt at a new connection is noted on a socket
222  * which accepts connections, sonewconn is called.  If the
223  * connection is possible (subject to space constraints, etc.)
224  * then we allocate a new structure, propoerly linked into the
225  * data structure of the original socket, and return this.
226  * Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED.
227  */
228 struct socket *
229 sonewconn(struct socket *head, int connstatus)
230 {
231 	struct socket *so;
232 	struct socket *sp;
233 	struct pru_attach_info ai;
234 
235 	if (head->so_qlen > 3 * head->so_qlimit / 2)
236 		return (NULL);
237 	so = soalloc(1);
238 	if (so == NULL)
239 		return (NULL);
240 	if ((head->so_options & SO_ACCEPTFILTER) != 0)
241 		connstatus = 0;
242 	so->so_head = head;
243 	so->so_type = head->so_type;
244 	so->so_options = head->so_options &~ SO_ACCEPTCONN;
245 	so->so_linger = head->so_linger;
246 	so->so_state = head->so_state | SS_NOFDREF;
247 	so->so_proto = head->so_proto;
248 	so->so_timeo = head->so_timeo;
249 	so->so_cred = crhold(head->so_cred);
250 	ai.sb_rlimit = NULL;
251 	ai.p_ucred = NULL;
252 	ai.fd_rdir = NULL;		/* jail code cruft XXX JH */
253 	if (soreserve(so, head->so_snd.ssb_hiwat, head->so_rcv.ssb_hiwat, NULL) ||
254 	    /* Directly call function since we're already at protocol level. */
255 	    (*so->so_proto->pr_usrreqs->pru_attach)(so, 0, &ai)) {
256 		sodealloc(so);
257 		return (NULL);
258 	}
259 
260 	if (connstatus) {
261 		TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
262 		so->so_state |= SS_COMP;
263 		head->so_qlen++;
264 	} else {
265 		if (head->so_incqlen > head->so_qlimit) {
266 			sp = TAILQ_FIRST(&head->so_incomp);
267 			TAILQ_REMOVE(&head->so_incomp, sp, so_list);
268 			head->so_incqlen--;
269 			sp->so_state &= ~SS_INCOMP;
270 			sp->so_head = NULL;
271 			soaborta(sp);
272 		}
273 		TAILQ_INSERT_TAIL(&head->so_incomp, so, so_list);
274 		so->so_state |= SS_INCOMP;
275 		head->so_incqlen++;
276 	}
277 	if (connstatus) {
278 		sorwakeup(head);
279 		wakeup((caddr_t)&head->so_timeo);
280 		so->so_state |= connstatus;
281 	}
282 	return (so);
283 }
284 
285 /*
286  * Socantsendmore indicates that no more data will be sent on the
287  * socket; it would normally be applied to a socket when the user
288  * informs the system that no more data is to be sent, by the protocol
289  * code (in case PRU_SHUTDOWN).  Socantrcvmore indicates that no more data
290  * will be received, and will normally be applied to the socket by a
291  * protocol when it detects that the peer will send no more data.
292  * Data queued for reading in the socket may yet be read.
293  */
294 void
295 socantsendmore(struct socket *so)
296 {
297 	so->so_state |= SS_CANTSENDMORE;
298 	sowwakeup(so);
299 }
300 
301 void
302 socantrcvmore(struct socket *so)
303 {
304 	so->so_state |= SS_CANTRCVMORE;
305 	sorwakeup(so);
306 }
307 
308 /*
309  * Wakeup processes waiting on a socket buffer.  Do asynchronous notification
310  * via SIGIO if the socket has the SS_ASYNC flag set.
311  */
312 void
313 sowakeup(struct socket *so, struct signalsockbuf *ssb)
314 {
315 	struct selinfo *selinfo = &ssb->ssb_sel;
316 
317 	selwakeup(selinfo);
318 	ssb->ssb_flags &= ~SSB_SEL;
319 	if (ssb->ssb_flags & SSB_WAIT) {
320 		ssb->ssb_flags &= ~SSB_WAIT;
321 		wakeup((caddr_t)&ssb->ssb_cc);
322 	}
323 	if ((so->so_state & SS_ASYNC) && so->so_sigio != NULL)
324 		pgsigio(so->so_sigio, SIGIO, 0);
325 	if (ssb->ssb_flags & SSB_UPCALL)
326 		(*so->so_upcall)(so, so->so_upcallarg, MB_DONTWAIT);
327 	if (ssb->ssb_flags & SSB_AIO)
328 		aio_swake(so, ssb);
329 	KNOTE(&selinfo->si_note, 0);
330 	if (ssb->ssb_flags & SSB_MEVENT) {
331 		struct netmsg_so_notify *msg, *nmsg;
332 
333 		TAILQ_FOREACH_MUTABLE(msg, &selinfo->si_mlist, nm_list, nmsg) {
334 			if (msg->nm_predicate(&msg->nm_netmsg)) {
335 				TAILQ_REMOVE(&selinfo->si_mlist, msg, nm_list);
336 				lwkt_replymsg(&msg->nm_netmsg.nm_lmsg,
337 					      msg->nm_netmsg.nm_lmsg.ms_error);
338 			}
339 		}
340 		if (TAILQ_EMPTY(&ssb->ssb_sel.si_mlist))
341 			ssb->ssb_flags &= ~SSB_MEVENT;
342 	}
343 }
344 
345 /*
346  * Socket buffer (struct signalsockbuf) utility routines.
347  *
348  * Each socket contains two socket buffers: one for sending data and
349  * one for receiving data.  Each buffer contains a queue of mbufs,
350  * information about the number of mbufs and amount of data in the
351  * queue, and other fields allowing select() statements and notification
352  * on data availability to be implemented.
353  *
354  * Data stored in a socket buffer is maintained as a list of records.
355  * Each record is a list of mbufs chained together with the m_next
356  * field.  Records are chained together with the m_nextpkt field. The upper
357  * level routine soreceive() expects the following conventions to be
358  * observed when placing information in the receive buffer:
359  *
360  * 1. If the protocol requires each message be preceded by the sender's
361  *    name, then a record containing that name must be present before
362  *    any associated data (mbuf's must be of type MT_SONAME).
363  * 2. If the protocol supports the exchange of ``access rights'' (really
364  *    just additional data associated with the message), and there are
365  *    ``rights'' to be received, then a record containing this data
366  *    should be present (mbuf's must be of type MT_RIGHTS).
367  * 3. If a name or rights record exists, then it must be followed by
368  *    a data record, perhaps of zero length.
369  *
370  * Before using a new socket structure it is first necessary to reserve
371  * buffer space to the socket, by calling sbreserve().  This should commit
372  * some of the available buffer space in the system buffer pool for the
373  * socket (currently, it does nothing but enforce limits).  The space
374  * should be released by calling ssb_release() when the socket is destroyed.
375  */
376 int
377 soreserve(struct socket *so, u_long sndcc, u_long rcvcc, struct rlimit *rl)
378 {
379 	if (ssb_reserve(&so->so_snd, sndcc, so, rl) == 0)
380 		goto bad;
381 	if (ssb_reserve(&so->so_rcv, rcvcc, so, rl) == 0)
382 		goto bad2;
383 	if (so->so_rcv.ssb_lowat == 0)
384 		so->so_rcv.ssb_lowat = 1;
385 	if (so->so_snd.ssb_lowat == 0)
386 		so->so_snd.ssb_lowat = MCLBYTES;
387 	if (so->so_snd.ssb_lowat > so->so_snd.ssb_hiwat)
388 		so->so_snd.ssb_lowat = so->so_snd.ssb_hiwat;
389 	return (0);
390 bad2:
391 	ssb_release(&so->so_snd, so);
392 bad:
393 	return (ENOBUFS);
394 }
395 
396 static int
397 sysctl_handle_sb_max(SYSCTL_HANDLER_ARGS)
398 {
399 	int error = 0;
400 	u_long old_sb_max = sb_max;
401 
402 	error = SYSCTL_OUT(req, arg1, sizeof(int));
403 	if (error || !req->newptr)
404 		return (error);
405 	error = SYSCTL_IN(req, arg1, sizeof(int));
406 	if (error)
407 		return (error);
408 	if (sb_max < MSIZE + MCLBYTES) {
409 		sb_max = old_sb_max;
410 		return (EINVAL);
411 	}
412 	sb_max_adj = (u_quad_t)sb_max * MCLBYTES / (MSIZE + MCLBYTES);
413 	return (0);
414 }
415 
416 /*
417  * Allot mbufs to a signalsockbuf.
418  * Attempt to scale mbmax so that mbcnt doesn't become limiting
419  * if buffering efficiency is near the normal case.
420  */
421 int
422 ssb_reserve(struct signalsockbuf *ssb, u_long cc, struct socket *so,
423 	    struct rlimit *rl)
424 {
425 	/*
426 	 * rl will only be NULL when we're in an interrupt (eg, in tcp_input)
427 	 * or when called from netgraph (ie, ngd_attach)
428 	 */
429 	if (cc > sb_max_adj)
430 		cc = sb_max_adj;
431 	if (!chgsbsize(so->so_cred->cr_uidinfo, &ssb->ssb_hiwat, cc,
432 		       rl ? rl->rlim_cur : RLIM_INFINITY)) {
433 		return (0);
434 	}
435 	ssb->ssb_mbmax = min(cc * sb_efficiency, sb_max);
436 	if (ssb->ssb_lowat > ssb->ssb_hiwat)
437 		ssb->ssb_lowat = ssb->ssb_hiwat;
438 	return (1);
439 }
440 
441 /*
442  * Free mbufs held by a socket, and reserved mbuf space.
443  */
444 void
445 ssb_release(struct signalsockbuf *ssb, struct socket *so)
446 {
447 	sbflush(&ssb->sb);
448 	(void)chgsbsize(so->so_cred->cr_uidinfo, &ssb->ssb_hiwat, 0,
449 	    RLIM_INFINITY);
450 	ssb->ssb_mbmax = 0;
451 }
452 
453 /*
454  * Some routines that return EOPNOTSUPP for entry points that are not
455  * supported by a protocol.  Fill in as needed.
456  */
457 int
458 pru_accept_notsupp(struct socket *so, struct sockaddr **nam)
459 {
460 	return EOPNOTSUPP;
461 }
462 
463 int
464 pru_bind_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
465 {
466 	return EOPNOTSUPP;
467 }
468 
469 int
470 pru_connect_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
471 {
472 	return EOPNOTSUPP;
473 }
474 
475 int
476 pru_connect2_notsupp(struct socket *so1, struct socket *so2)
477 {
478 	return EOPNOTSUPP;
479 }
480 
481 int
482 pru_control_notsupp(struct socket *so, u_long cmd, caddr_t data,
483 		    struct ifnet *ifp, struct thread *td)
484 {
485 	return EOPNOTSUPP;
486 }
487 
488 int
489 pru_disconnect_notsupp(struct socket *so)
490 {
491 	return EOPNOTSUPP;
492 }
493 
494 int
495 pru_listen_notsupp(struct socket *so, struct thread *td)
496 {
497 	return EOPNOTSUPP;
498 }
499 
500 int
501 pru_peeraddr_notsupp(struct socket *so, struct sockaddr **nam)
502 {
503 	return EOPNOTSUPP;
504 }
505 
506 int
507 pru_rcvd_notsupp(struct socket *so, int flags)
508 {
509 	return EOPNOTSUPP;
510 }
511 
512 int
513 pru_rcvoob_notsupp(struct socket *so, struct mbuf *m, int flags)
514 {
515 	return EOPNOTSUPP;
516 }
517 
518 int
519 pru_shutdown_notsupp(struct socket *so)
520 {
521 	return EOPNOTSUPP;
522 }
523 
524 int
525 pru_sockaddr_notsupp(struct socket *so, struct sockaddr **nam)
526 {
527 	return EOPNOTSUPP;
528 }
529 
530 int
531 pru_sosend_notsupp(struct socket *so, struct sockaddr *addr, struct uio *uio,
532 	   struct mbuf *top, struct mbuf *control, int flags,
533 	   struct thread *td)
534 {
535 	if (top)
536 		m_freem(top);
537 	if (control)
538 		m_freem(control);
539 	return (EOPNOTSUPP);
540 }
541 
542 int
543 pru_soreceive_notsupp(struct socket *so, struct sockaddr **paddr,
544 		      struct uio *uio, struct sockbuf *sio,
545 		      struct mbuf **controlp, int *flagsp)
546 {
547 	return (EOPNOTSUPP);
548 }
549 
550 int
551 pru_sopoll_notsupp(struct socket *so, int events,
552 		   struct ucred *cred, struct thread *td)
553 {
554 	return (EOPNOTSUPP);
555 }
556 
557 int
558 pru_ctloutput_notsupp(struct socket *so, struct sockopt *sopt)
559 {
560 	return (EOPNOTSUPP);
561 }
562 
563 /*
564  * This isn't really a ``null'' operation, but it's the default one
565  * and doesn't do anything destructive.
566  */
567 int
568 pru_sense_null(struct socket *so, struct stat *sb)
569 {
570 	sb->st_blksize = so->so_snd.ssb_hiwat;
571 	return 0;
572 }
573 
574 /*
575  * Make a copy of a sockaddr in a malloced buffer of type M_SONAME.  Callers
576  * of this routine assume that it always succeeds, so we have to use a
577  * blockable allocation even though we might be called from a critical thread.
578  */
579 struct sockaddr *
580 dup_sockaddr(const struct sockaddr *sa)
581 {
582 	struct sockaddr *sa2;
583 
584 	sa2 = kmalloc(sa->sa_len, M_SONAME, M_INTWAIT);
585 	bcopy(sa, sa2, sa->sa_len);
586 	return (sa2);
587 }
588 
589 /*
590  * Create an external-format (``xsocket'') structure using the information
591  * in the kernel-format socket structure pointed to by so.  This is done
592  * to reduce the spew of irrelevant information over this interface,
593  * to isolate user code from changes in the kernel structure, and
594  * potentially to provide information-hiding if we decide that
595  * some of this information should be hidden from users.
596  */
597 void
598 sotoxsocket(struct socket *so, struct xsocket *xso)
599 {
600 	xso->xso_len = sizeof *xso;
601 	xso->xso_so = so;
602 	xso->so_type = so->so_type;
603 	xso->so_options = so->so_options;
604 	xso->so_linger = so->so_linger;
605 	xso->so_state = so->so_state;
606 	xso->so_pcb = so->so_pcb;
607 	xso->xso_protocol = so->so_proto->pr_protocol;
608 	xso->xso_family = so->so_proto->pr_domain->dom_family;
609 	xso->so_qlen = so->so_qlen;
610 	xso->so_incqlen = so->so_incqlen;
611 	xso->so_qlimit = so->so_qlimit;
612 	xso->so_timeo = so->so_timeo;
613 	xso->so_error = so->so_error;
614 	xso->so_pgid = so->so_sigio ? so->so_sigio->sio_pgid : 0;
615 	xso->so_oobmark = so->so_oobmark;
616 	ssbtoxsockbuf(&so->so_snd, &xso->so_snd);
617 	ssbtoxsockbuf(&so->so_rcv, &xso->so_rcv);
618 	xso->so_uid = so->so_cred->cr_uid;
619 }
620 
621 /*
622  * Here is the definition of some of the basic objects in the kern.ipc
623  * branch of the MIB.
624  */
625 SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW, 0, "IPC");
626 
627 /* This takes the place of kern.maxsockbuf, which moved to kern.ipc. */
628 static int dummy;
629 SYSCTL_INT(_kern, KERN_DUMMY, dummy, CTLFLAG_RW, &dummy, 0, "");
630 SYSCTL_OID(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf, CTLTYPE_INT|CTLFLAG_RW,
631     &sb_max, 0, sysctl_handle_sb_max, "I", "Maximum socket buffer size");
632 SYSCTL_INT(_kern_ipc, OID_AUTO, maxsockets, CTLFLAG_RD,
633     &maxsockets, 0, "Maximum number of sockets available");
634 SYSCTL_INT(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW,
635     &sb_efficiency, 0, "");
636 
637 /*
638  * Initialize maxsockets
639  */
640 static void
641 init_maxsockets(void *ignored)
642 {
643     TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets);
644     maxsockets = imax(maxsockets, imax(maxfiles, nmbclusters));
645 }
646 SYSINIT(param, SI_BOOT1_TUNABLES, SI_ORDER_ANY,
647 	init_maxsockets, NULL);
648 
649