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.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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.
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
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 $
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>
46 #include <sys/malloc.h>
48 #include <sys/protosw.h>
49 #include <sys/resourcevar.h>
51 #include <sys/socket.h>
52 #include <sys/socketvar.h>
53 #include <sys/socketops.h>
54 #include <sys/signalvar.h>
55 #include <sys/sysctl.h>
56 #include <sys/aio.h> /* for aio_swake proto */
57 #include <sys/event.h>
59 #include <sys/thread2.h>
60 #include <sys/msgport2.h>
61 #include <sys/socketvar2.h>
66 * Primitive routines for operating on sockets and socket buffers
69 u_long sb_max = SB_MAX;
71 SB_MAX * MCLBYTES / (MSIZE + MCLBYTES); /* adjusted sb_max */
73 static u_long sb_efficiency = 8; /* parameter for sbreserve() */
75 /************************************************************************
76 * signalsockbuf procedures *
77 ************************************************************************/
80 * Wait for data to arrive at/drain from a socket buffer.
82 * NOTE: Caller must generally hold the ssb_lock (client side lock) since
83 * WAIT/WAKEUP only works for one client at a time.
85 * NOTE: Caller always retries whatever operation it was waiting on.
88 ssb_wait(struct signalsockbuf *ssb)
94 pflags = (ssb->ssb_flags & SSB_NOINTR) ? 0 : PCATCH;
97 flags = ssb->ssb_flags;
101 * WAKEUP and WAIT interlock eachother. We can catch the
102 * race by checking to see if WAKEUP has already been set,
103 * and only setting WAIT if WAKEUP is clear.
105 if (flags & SSB_WAKEUP) {
106 if (atomic_cmpset_int(&ssb->ssb_flags, flags,
107 flags & ~SSB_WAKEUP)) {
115 * Only set WAIT if WAKEUP is clear.
117 tsleep_interlock(&ssb->ssb_cc, pflags);
118 if (atomic_cmpset_int(&ssb->ssb_flags, flags,
120 error = tsleep(&ssb->ssb_cc, pflags | PINTERLOCKED,
121 "sbwait", ssb->ssb_timeo);
129 * Lock a sockbuf already known to be locked;
130 * return any error returned from sleep (EINTR).
133 _ssb_lock(struct signalsockbuf *ssb)
139 pflags = (ssb->ssb_flags & SSB_NOINTR) ? 0 : PCATCH;
142 flags = ssb->ssb_flags;
144 if (flags & SSB_LOCK) {
145 tsleep_interlock(&ssb->ssb_flags, pflags);
146 if (atomic_cmpset_int(&ssb->ssb_flags, flags,
148 error = tsleep(&ssb->ssb_flags,
149 pflags | PINTERLOCKED,
155 if (atomic_cmpset_int(&ssb->ssb_flags, flags,
157 lwkt_gettoken(&ssb->ssb_token);
167 * This does the same for sockbufs. Note that the xsockbuf structure,
168 * since it is always embedded in a socket, does not include a self
169 * pointer nor a length. We make this entry point public in case
170 * some other mechanism needs it.
173 ssbtoxsockbuf(struct signalsockbuf *ssb, struct xsockbuf *xsb)
175 xsb->sb_cc = ssb->ssb_cc;
176 xsb->sb_hiwat = ssb->ssb_hiwat;
177 xsb->sb_mbcnt = ssb->ssb_mbcnt;
178 xsb->sb_mbmax = ssb->ssb_mbmax;
179 xsb->sb_lowat = ssb->ssb_lowat;
180 xsb->sb_flags = ssb->ssb_flags;
181 xsb->sb_timeo = ssb->ssb_timeo;
185 /************************************************************************
186 * Procedures which manipulate socket state flags, wakeups, etc. *
187 ************************************************************************
189 * Normal sequence from the active (originating) side is that
190 * soisconnecting() is called during processing of connect() call, resulting
191 * in an eventual call to soisconnected() if/when the connection is
192 * established. When the connection is torn down soisdisconnecting() is
193 * called during processing of disconnect() call, and soisdisconnected() is
194 * called when the connection to the peer is totally severed.
196 * The semantics of these routines are such that connectionless protocols
197 * can call soisconnected() and soisdisconnected() only, bypassing the
198 * in-progress calls when setting up a ``connection'' takes no time.
200 * From the passive side, a socket is created with two queues of sockets:
201 * so_incomp for connections in progress and so_comp for connections
202 * already made and awaiting user acceptance. As a protocol is preparing
203 * incoming connections, it creates a socket structure queued on so_incomp
204 * by calling sonewconn(). When the connection is established,
205 * soisconnected() is called, and transfers the socket structure to so_comp,
206 * making it available to accept().
208 * If a socket is closed with sockets on either so_incomp or so_comp, these
209 * sockets are dropped.
211 * If higher level protocols are implemented in the kernel, the wakeups
212 * done here will sometimes cause software-interrupt process scheduling.
216 soisconnecting(struct socket *so)
218 soclrstate(so, SS_ISCONNECTED | SS_ISDISCONNECTING);
219 sosetstate(so, SS_ISCONNECTING);
223 soisconnected(struct socket *so)
225 struct socket *head = so->so_head;
227 soclrstate(so, SS_ISCONNECTING | SS_ISDISCONNECTING | SS_ISCONFIRMING);
228 sosetstate(so, SS_ISCONNECTED);
229 if (head && (so->so_state & SS_INCOMP)) {
230 if ((so->so_options & SO_ACCEPTFILTER) != 0) {
231 so->so_upcall = head->so_accf->so_accept_filter->accf_callback;
232 so->so_upcallarg = head->so_accf->so_accept_filter_arg;
233 atomic_set_int(&so->so_rcv.ssb_flags, SSB_UPCALL);
234 so->so_options &= ~SO_ACCEPTFILTER;
235 so->so_upcall(so, so->so_upcallarg, 0);
240 * Listen socket are not per-cpu.
242 lwkt_gettoken(&head->so_rcv.ssb_token);
243 TAILQ_REMOVE(&head->so_incomp, so, so_list);
245 TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
247 sosetstate(so, SS_COMP);
248 soclrstate(so, SS_INCOMP);
249 lwkt_reltoken(&head->so_rcv.ssb_token);
252 * XXX head may be on a different protocol thread.
253 * sorwakeup()->sowakeup() is hacked atm.
256 wakeup_one(&head->so_timeo);
258 wakeup(&so->so_timeo);
265 soisdisconnecting(struct socket *so)
267 soclrstate(so, SS_ISCONNECTING);
268 sosetstate(so, SS_ISDISCONNECTING | SS_CANTRCVMORE | SS_CANTSENDMORE);
269 wakeup((caddr_t)&so->so_timeo);
275 soisdisconnected(struct socket *so)
277 soclrstate(so, SS_ISCONNECTING | SS_ISCONNECTED | SS_ISDISCONNECTING);
278 sosetstate(so, SS_CANTRCVMORE | SS_CANTSENDMORE | SS_ISDISCONNECTED);
279 wakeup((caddr_t)&so->so_timeo);
280 sbdrop(&so->so_snd.sb, so->so_snd.ssb_cc);
286 soisreconnecting(struct socket *so)
288 soclrstate(so, SS_ISDISCONNECTING | SS_ISDISCONNECTED |
289 SS_CANTRCVMORE | SS_CANTSENDMORE);
290 sosetstate(so, SS_ISCONNECTING);
294 soisreconnected(struct socket *so)
296 soclrstate(so, SS_ISDISCONNECTED | SS_CANTRCVMORE | SS_CANTSENDMORE);
301 * Set or change the message port a socket receives commands on.
306 sosetport(struct socket *so, lwkt_port_t port)
312 * When an attempt at a new connection is noted on a socket
313 * which accepts connections, sonewconn is called. If the
314 * connection is possible (subject to space constraints, etc.)
315 * then we allocate a new structure, propoerly linked into the
316 * data structure of the original socket, and return this.
317 * Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED.
319 * The new socket is returned with one ref and so_pcb assigned.
320 * The reference is implied by so_pcb.
323 sonewconn(struct socket *head, int connstatus)
327 struct pru_attach_info ai;
329 if (head->so_qlen > 3 * head->so_qlimit / 2)
336 * Set the port prior to attaching the inpcb to the current
337 * cpu's protocol thread (which should be the current thread
338 * but might not be in all cases). This serializes any pcb ops
339 * which occur to our cpu allowing us to complete the attachment
340 * without racing anything.
342 sosetport(so, cpu_portfn(mycpu->gd_cpuid));
343 if ((head->so_options & SO_ACCEPTFILTER) != 0)
346 so->so_type = head->so_type;
347 so->so_options = head->so_options &~ SO_ACCEPTCONN;
348 so->so_linger = head->so_linger;
351 * NOTE: Clearing NOFDREF implies referencing the so with
354 so->so_state = head->so_state | SS_NOFDREF | SS_ASSERTINPROG;
355 so->so_proto = head->so_proto;
356 so->so_cred = crhold(head->so_cred);
359 ai.fd_rdir = NULL; /* jail code cruft XXX JH */
362 * Reserve space and call pru_attach. We can direct-call the
363 * function since we're already in the protocol thread.
365 if (soreserve(so, head->so_snd.ssb_hiwat,
366 head->so_rcv.ssb_hiwat, NULL) ||
367 so_pru_attach_direct(so, 0, &ai)) {
369 soclrstate(so, SS_ASSERTINPROG);
370 sofree(so); /* remove implied pcb ref */
373 KKASSERT(so->so_refs == 2); /* attach + our base ref */
375 KKASSERT(so->so_port != NULL);
376 so->so_rcv.ssb_lowat = head->so_rcv.ssb_lowat;
377 so->so_snd.ssb_lowat = head->so_snd.ssb_lowat;
378 so->so_rcv.ssb_timeo = head->so_rcv.ssb_timeo;
379 so->so_snd.ssb_timeo = head->so_snd.ssb_timeo;
380 so->so_rcv.ssb_flags |= head->so_rcv.ssb_flags &
381 (SSB_AUTOSIZE | SSB_AUTOLOWAT);
382 so->so_snd.ssb_flags |= head->so_snd.ssb_flags &
383 (SSB_AUTOSIZE | SSB_AUTOLOWAT);
384 lwkt_gettoken(&head->so_rcv.ssb_token);
386 TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
387 sosetstate(so, SS_COMP);
390 if (head->so_incqlen > head->so_qlimit) {
391 sp = TAILQ_FIRST(&head->so_incomp);
392 TAILQ_REMOVE(&head->so_incomp, sp, so_list);
394 soclrstate(sp, SS_INCOMP);
398 TAILQ_INSERT_TAIL(&head->so_incomp, so, so_list);
399 sosetstate(so, SS_INCOMP);
402 lwkt_reltoken(&head->so_rcv.ssb_token);
405 * XXX head may be on a different protocol thread.
406 * sorwakeup()->sowakeup() is hacked atm.
409 wakeup((caddr_t)&head->so_timeo);
410 sosetstate(so, connstatus);
412 soclrstate(so, SS_ASSERTINPROG);
417 * Socantsendmore indicates that no more data will be sent on the
418 * socket; it would normally be applied to a socket when the user
419 * informs the system that no more data is to be sent, by the protocol
420 * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data
421 * will be received, and will normally be applied to the socket by a
422 * protocol when it detects that the peer will send no more data.
423 * Data queued for reading in the socket may yet be read.
426 socantsendmore(struct socket *so)
428 sosetstate(so, SS_CANTSENDMORE);
433 socantrcvmore(struct socket *so)
435 sosetstate(so, SS_CANTRCVMORE);
440 * Wakeup processes waiting on a socket buffer. Do asynchronous notification
441 * via SIGIO if the socket has the SS_ASYNC flag set.
443 * For users waiting on send/recv try to avoid unnecessary context switch
444 * thrashing. Particularly for senders of large buffers (needs to be
445 * extended to sel and aio? XXX)
447 * WARNING! Can be called on a foreign socket from the wrong protocol
448 * thread. aka is called on the 'head' listen socket when
449 * a new connection comes in.
452 sowakeup(struct socket *so, struct signalsockbuf *ssb)
454 struct kqinfo *kqinfo = &ssb->ssb_kq;
458 * Check conditions, set the WAKEUP flag, and clear and signal if
459 * the WAIT flag is found to be set. This interlocks against the
463 flags = ssb->ssb_flags;
466 if ((ssb == &so->so_snd && ssb_space(ssb) >= ssb->ssb_lowat) ||
467 (ssb == &so->so_rcv && ssb->ssb_cc >= ssb->ssb_lowat) ||
468 (ssb == &so->so_snd && (so->so_state & SS_CANTSENDMORE)) ||
469 (ssb == &so->so_rcv && (so->so_state & SS_CANTRCVMORE))
471 if (atomic_cmpset_int(&ssb->ssb_flags, flags,
472 (flags | SSB_WAKEUP) & ~SSB_WAIT)) {
473 if (flags & SSB_WAIT)
474 wakeup(&ssb->ssb_cc);
485 if ((so->so_state & SS_ASYNC) && so->so_sigio != NULL)
486 pgsigio(so->so_sigio, SIGIO, 0);
487 if (ssb->ssb_flags & SSB_UPCALL)
488 (*so->so_upcall)(so, so->so_upcallarg, MB_DONTWAIT);
489 if (ssb->ssb_flags & SSB_AIO)
491 KNOTE(&kqinfo->ki_note, 0);
494 * This is a bit of a hack. Multiple threads can wind up scanning
495 * ki_mlist concurrently due to the fact that this function can be
496 * called on a foreign socket, so we can't afford to block here.
498 if (ssb->ssb_flags & SSB_MEVENT) {
499 struct netmsg_so_notify *msg, *nmsg;
501 lwkt_gettoken(&kq_token);
502 lwkt_gettoken_hard(&ssb->ssb_token);
503 TAILQ_FOREACH_MUTABLE(msg, &kqinfo->ki_mlist, nm_list, nmsg) {
504 if (msg->nm_predicate(msg)) {
505 TAILQ_REMOVE(&kqinfo->ki_mlist, msg, nm_list);
506 lwkt_replymsg(&msg->base.lmsg,
507 msg->base.lmsg.ms_error);
510 if (TAILQ_EMPTY(&ssb->ssb_kq.ki_mlist))
511 atomic_clear_int(&ssb->ssb_flags, SSB_MEVENT);
512 lwkt_reltoken_hard(&ssb->ssb_token);
513 lwkt_reltoken(&kq_token);
518 * Socket buffer (struct signalsockbuf) utility routines.
520 * Each socket contains two socket buffers: one for sending data and
521 * one for receiving data. Each buffer contains a queue of mbufs,
522 * information about the number of mbufs and amount of data in the
523 * queue, and other fields allowing kevent()/select()/poll() statements
524 * and notification on data availability to be implemented.
526 * Data stored in a socket buffer is maintained as a list of records.
527 * Each record is a list of mbufs chained together with the m_next
528 * field. Records are chained together with the m_nextpkt field. The upper
529 * level routine soreceive() expects the following conventions to be
530 * observed when placing information in the receive buffer:
532 * 1. If the protocol requires each message be preceded by the sender's
533 * name, then a record containing that name must be present before
534 * any associated data (mbuf's must be of type MT_SONAME).
535 * 2. If the protocol supports the exchange of ``access rights'' (really
536 * just additional data associated with the message), and there are
537 * ``rights'' to be received, then a record containing this data
538 * should be present (mbuf's must be of type MT_RIGHTS).
539 * 3. If a name or rights record exists, then it must be followed by
540 * a data record, perhaps of zero length.
542 * Before using a new socket structure it is first necessary to reserve
543 * buffer space to the socket, by calling sbreserve(). This should commit
544 * some of the available buffer space in the system buffer pool for the
545 * socket (currently, it does nothing but enforce limits). The space
546 * should be released by calling ssb_release() when the socket is destroyed.
549 soreserve(struct socket *so, u_long sndcc, u_long rcvcc, struct rlimit *rl)
551 if (so->so_snd.ssb_lowat == 0)
552 atomic_set_int(&so->so_snd.ssb_flags, SSB_AUTOLOWAT);
553 if (ssb_reserve(&so->so_snd, sndcc, so, rl) == 0)
555 if (ssb_reserve(&so->so_rcv, rcvcc, so, rl) == 0)
557 if (so->so_rcv.ssb_lowat == 0)
558 so->so_rcv.ssb_lowat = 1;
559 if (so->so_snd.ssb_lowat == 0)
560 so->so_snd.ssb_lowat = MCLBYTES;
561 if (so->so_snd.ssb_lowat > so->so_snd.ssb_hiwat)
562 so->so_snd.ssb_lowat = so->so_snd.ssb_hiwat;
565 ssb_release(&so->so_snd, so);
571 sysctl_handle_sb_max(SYSCTL_HANDLER_ARGS)
574 u_long old_sb_max = sb_max;
576 error = SYSCTL_OUT(req, arg1, sizeof(int));
577 if (error || !req->newptr)
579 error = SYSCTL_IN(req, arg1, sizeof(int));
582 if (sb_max < MSIZE + MCLBYTES) {
586 sb_max_adj = (u_quad_t)sb_max * MCLBYTES / (MSIZE + MCLBYTES);
591 * Allot mbufs to a signalsockbuf.
593 * Attempt to scale mbmax so that mbcnt doesn't become limiting
594 * if buffering efficiency is near the normal case.
596 * sb_max only applies to user-sockets (where rl != NULL). It does
597 * not apply to kernel sockets or kernel-controlled sockets. Note
598 * that NFS overrides the sockbuf limits created when nfsd creates
602 ssb_reserve(struct signalsockbuf *ssb, u_long cc, struct socket *so,
606 * rl will only be NULL when we're in an interrupt (eg, in tcp_input)
607 * or when called from netgraph (ie, ngd_attach)
609 if (rl && cc > sb_max_adj)
611 if (!chgsbsize(so->so_cred->cr_uidinfo, &ssb->ssb_hiwat, cc,
612 rl ? rl->rlim_cur : RLIM_INFINITY)) {
616 ssb->ssb_mbmax = min(cc * sb_efficiency, sb_max);
618 ssb->ssb_mbmax = cc * sb_efficiency;
621 * AUTOLOWAT is set on send buffers and prevents large writes
622 * from generating a huge number of context switches.
624 if (ssb->ssb_flags & SSB_AUTOLOWAT) {
625 ssb->ssb_lowat = ssb->ssb_hiwat / 2;
626 if (ssb->ssb_lowat < MCLBYTES)
627 ssb->ssb_lowat = MCLBYTES;
629 if (ssb->ssb_lowat > ssb->ssb_hiwat)
630 ssb->ssb_lowat = ssb->ssb_hiwat;
635 * Free mbufs held by a socket, and reserved mbuf space.
638 ssb_release(struct signalsockbuf *ssb, struct socket *so)
641 (void)chgsbsize(so->so_cred->cr_uidinfo, &ssb->ssb_hiwat, 0,
647 * Some routines that return EOPNOTSUPP for entry points that are not
648 * supported by a protocol. Fill in as needed.
651 pr_generic_notsupp(netmsg_t msg)
653 lwkt_replymsg(&msg->lmsg, EOPNOTSUPP);
657 pru_sosend_notsupp(struct socket *so, struct sockaddr *addr, struct uio *uio,
658 struct mbuf *top, struct mbuf *control, int flags,
669 pru_soreceive_notsupp(struct socket *so, struct sockaddr **paddr,
670 struct uio *uio, struct sockbuf *sio,
671 struct mbuf **controlp, int *flagsp)
677 * This isn't really a ``null'' operation, but it's the default one
678 * and doesn't do anything destructive.
681 pru_sense_null(netmsg_t msg)
683 msg->sense.nm_stat->st_blksize = msg->base.nm_so->so_snd.ssb_hiwat;
684 lwkt_replymsg(&msg->lmsg, 0);
688 * Make a copy of a sockaddr in a malloced buffer of type M_SONAME. Callers
689 * of this routine assume that it always succeeds, so we have to use a
690 * blockable allocation even though we might be called from a critical thread.
693 dup_sockaddr(const struct sockaddr *sa)
695 struct sockaddr *sa2;
697 sa2 = kmalloc(sa->sa_len, M_SONAME, M_INTWAIT);
698 bcopy(sa, sa2, sa->sa_len);
703 * Create an external-format (``xsocket'') structure using the information
704 * in the kernel-format socket structure pointed to by so. This is done
705 * to reduce the spew of irrelevant information over this interface,
706 * to isolate user code from changes in the kernel structure, and
707 * potentially to provide information-hiding if we decide that
708 * some of this information should be hidden from users.
711 sotoxsocket(struct socket *so, struct xsocket *xso)
713 xso->xso_len = sizeof *xso;
715 xso->so_type = so->so_type;
716 xso->so_options = so->so_options;
717 xso->so_linger = so->so_linger;
718 xso->so_state = so->so_state;
719 xso->so_pcb = so->so_pcb;
720 xso->xso_protocol = so->so_proto->pr_protocol;
721 xso->xso_family = so->so_proto->pr_domain->dom_family;
722 xso->so_qlen = so->so_qlen;
723 xso->so_incqlen = so->so_incqlen;
724 xso->so_qlimit = so->so_qlimit;
725 xso->so_timeo = so->so_timeo;
726 xso->so_error = so->so_error;
727 xso->so_pgid = so->so_sigio ? so->so_sigio->sio_pgid : 0;
728 xso->so_oobmark = so->so_oobmark;
729 ssbtoxsockbuf(&so->so_snd, &xso->so_snd);
730 ssbtoxsockbuf(&so->so_rcv, &xso->so_rcv);
731 xso->so_uid = so->so_cred->cr_uid;
735 * Here is the definition of some of the basic objects in the kern.ipc
738 SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW, 0, "IPC");
741 * This takes the place of kern.maxsockbuf, which moved to kern.ipc.
743 * NOTE! sb_max only applies to user-created socket buffers.
746 SYSCTL_INT(_kern, KERN_DUMMY, dummy, CTLFLAG_RW, &dummy, 0, "");
747 SYSCTL_OID(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf, CTLTYPE_INT|CTLFLAG_RW,
748 &sb_max, 0, sysctl_handle_sb_max, "I", "Maximum socket buffer size");
749 SYSCTL_INT(_kern_ipc, OID_AUTO, maxsockets, CTLFLAG_RD,
750 &maxsockets, 0, "Maximum number of sockets available");
751 SYSCTL_INT(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW,
752 &sb_efficiency, 0, "");
755 * Initialize maxsockets
758 init_maxsockets(void *ignored)
760 TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets);
761 maxsockets = imax(maxsockets, imax(maxfiles, nmbclusters));
763 SYSINIT(param, SI_BOOT1_TUNABLES, SI_ORDER_ANY,
764 init_maxsockets, NULL);