1/*
2 * Copyright (c) 1998-2012 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
29/*
30 * Copyright (c) 1982, 1986, 1988, 1990, 1993
31 *	The Regents of the University of California.  All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without
34 * modification, are permitted provided that the following conditions
35 * are met:
36 * 1. Redistributions of source code must retain the above copyright
37 *    notice, this list of conditions and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright
39 *    notice, this list of conditions and the following disclaimer in the
40 *    documentation and/or other materials provided with the distribution.
41 * 3. All advertising materials mentioning features or use of this software
42 *    must display the following acknowledgement:
43 *	This product includes software developed by the University of
44 *	California, Berkeley and its contributors.
45 * 4. Neither the name of the University nor the names of its contributors
46 *    may be used to endorse or promote products derived from this software
47 *    without specific prior written permission.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59 * SUCH DAMAGE.
60 *
61 *	@(#)uipc_socket2.c	8.1 (Berkeley) 6/10/93
62 * $FreeBSD: src/sys/kern/uipc_socket2.c,v 1.55.2.9 2001/07/26 18:53:02 peter Exp $
63 */
64/*
65 * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
66 * support for mandatory and extensible security protections.  This notice
67 * is included in support of clause 2.2 (b) of the Apple Public License,
68 * Version 2.0.
69 */
70
71#include <sys/param.h>
72#include <sys/systm.h>
73#include <sys/domain.h>
74#include <sys/kernel.h>
75#include <sys/proc_internal.h>
76#include <sys/kauth.h>
77#include <sys/malloc.h>
78#include <sys/mbuf.h>
79#include <sys/mcache.h>
80#include <sys/protosw.h>
81#include <sys/stat.h>
82#include <sys/socket.h>
83#include <sys/socketvar.h>
84#include <sys/signalvar.h>
85#include <sys/sysctl.h>
86#include <sys/ev.h>
87#include <kern/locks.h>
88#include <net/route.h>
89#include <netinet/in.h>
90#include <netinet/in_pcb.h>
91#include <sys/kdebug.h>
92#include <libkern/OSAtomic.h>
93
94#if CONFIG_MACF
95#include <security/mac_framework.h>
96#endif
97
98#include <mach/vm_param.h>
99
100/* TODO: this should be in a header file somewhere */
101extern void postevent(struct socket *, struct sockbuf *, int);
102
103#define DBG_FNC_SBDROP	NETDBG_CODE(DBG_NETSOCK, 4)
104#define DBG_FNC_SBAPPEND	NETDBG_CODE(DBG_NETSOCK, 5)
105
106static inline void sbcompress(struct sockbuf *, struct mbuf *, struct mbuf *);
107static struct socket *sonewconn_internal(struct socket *, int);
108static int sbappendaddr_internal(struct sockbuf *, struct sockaddr *,
109    struct mbuf *, struct mbuf *);
110static int sbappendcontrol_internal(struct sockbuf *, struct mbuf *,
111    struct mbuf *);
112
113/*
114 * Primitive routines for operating on sockets and socket buffers
115 */
116static int soqlimitcompat = 1;
117static int soqlencomp = 0;
118
119/* Based on the number of mbuf clusters configured, high_sb_max and sb_max can get
120 * scaled up or down to suit that memory configuration. high_sb_max is a higher
121 * limit on sb_max that is checked when sb_max gets set through sysctl.
122 */
123
124u_int32_t	sb_max = SB_MAX;		/* XXX should be static */
125u_int32_t	high_sb_max = SB_MAX;
126
127static	u_int32_t sb_efficiency = 8;	/* parameter for sbreserve() */
128__private_extern__ int32_t total_sbmb_cnt = 0;
129
130/* Control whether to throttle sockets eligible to be throttled */
131__private_extern__ u_int32_t net_io_policy_throttled = 0;
132static int sysctl_io_policy_throttled SYSCTL_HANDLER_ARGS;
133
134/*
135 * Procedures to manipulate state flags of socket
136 * and do appropriate wakeups.  Normal sequence from the
137 * active (originating) side is that soisconnecting() is
138 * called during processing of connect() call,
139 * resulting in an eventual call to soisconnected() if/when the
140 * connection is established.  When the connection is torn down
141 * soisdisconnecting() is called during processing of disconnect() call,
142 * and soisdisconnected() is called when the connection to the peer
143 * is totally severed.  The semantics of these routines are such that
144 * connectionless protocols can call soisconnected() and soisdisconnected()
145 * only, bypassing the in-progress calls when setting up a ``connection''
146 * takes no time.
147 *
148 * From the passive side, a socket is created with
149 * two queues of sockets: so_incomp for connections in progress
150 * and so_comp for connections already made and awaiting user acceptance.
151 * As a protocol is preparing incoming connections, it creates a socket
152 * structure queued on so_incomp by calling sonewconn().  When the connection
153 * is established, soisconnected() is called, and transfers the
154 * socket structure to so_comp, making it available to accept().
155 *
156 * If a socket is closed with sockets on either
157 * so_incomp or so_comp, these sockets are dropped.
158 *
159 * If higher level protocols are implemented in
160 * the kernel, the wakeups done here will sometimes
161 * cause software-interrupt process scheduling.
162 */
163void
164soisconnecting(struct socket *so)
165{
166
167	so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
168	so->so_state |= SS_ISCONNECTING;
169
170	sflt_notify(so, sock_evt_connecting, NULL);
171}
172
173void
174soisconnected(struct socket *so)
175{
176	struct socket *head = so->so_head;
177
178	so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
179	so->so_state |= SS_ISCONNECTED;
180
181	sflt_notify(so, sock_evt_connected, NULL);
182
183	if (head && (so->so_state & SS_INCOMP)) {
184		so->so_state &= ~SS_INCOMP;
185		so->so_state |= SS_COMP;
186		if (head->so_proto->pr_getlock != NULL) {
187			socket_unlock(so, 0);
188			socket_lock(head, 1);
189		}
190		postevent(head, 0, EV_RCONN);
191		TAILQ_REMOVE(&head->so_incomp, so, so_list);
192		head->so_incqlen--;
193		TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
194		sorwakeup(head);
195		wakeup_one((caddr_t)&head->so_timeo);
196		if (head->so_proto->pr_getlock != NULL) {
197			socket_unlock(head, 1);
198			socket_lock(so, 0);
199		}
200	} else {
201		postevent(so, 0, EV_WCONN);
202		wakeup((caddr_t)&so->so_timeo);
203		sorwakeup(so);
204		sowwakeup(so);
205		soevent(so, SO_FILT_HINT_LOCKED);
206	}
207}
208
209void
210soisdisconnecting(struct socket *so)
211{
212	so->so_state &= ~SS_ISCONNECTING;
213	so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE);
214	soevent(so, SO_FILT_HINT_LOCKED);
215	sflt_notify(so, sock_evt_disconnecting, NULL);
216	wakeup((caddr_t)&so->so_timeo);
217	sowwakeup(so);
218	sorwakeup(so);
219}
220
221void
222soisdisconnected(struct socket *so)
223{
224	so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
225	so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED);
226	soevent(so, SO_FILT_HINT_LOCKED);
227	sflt_notify(so, sock_evt_disconnected, NULL);
228	wakeup((caddr_t)&so->so_timeo);
229	sowwakeup(so);
230	sorwakeup(so);
231}
232
233/* This function will issue a wakeup like soisdisconnected but it will not
234 * notify the socket filters. This will avoid unlocking the socket
235 * in the midst of closing it.
236 */
237void
238sodisconnectwakeup(struct socket *so)
239{
240	so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
241	so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED);
242	soevent(so, SO_FILT_HINT_LOCKED);
243	wakeup((caddr_t)&so->so_timeo);
244	sowwakeup(so);
245	sorwakeup(so);
246}
247
248/*
249 * When an attempt at a new connection is noted on a socket
250 * which accepts connections, sonewconn is called.  If the
251 * connection is possible (subject to space constraints, etc.)
252 * then we allocate a new structure, propoerly linked into the
253 * data structure of the original socket, and return this.
254 * Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED.
255 */
256static struct socket *
257sonewconn_internal(struct socket *head, int connstatus)
258{
259	int so_qlen, error = 0;
260	struct socket *so;
261	lck_mtx_t *mutex_held;
262
263	if (head->so_proto->pr_getlock != NULL)
264		mutex_held = (*head->so_proto->pr_getlock)(head, 0);
265	else
266		mutex_held = head->so_proto->pr_domain->dom_mtx;
267	lck_mtx_assert(mutex_held, LCK_MTX_ASSERT_OWNED);
268
269	if (!soqlencomp) {
270		/*
271		 * This is the default case; so_qlen represents the
272		 * sum of both incomplete and completed queues.
273		 */
274		so_qlen = head->so_qlen;
275	} else {
276		/*
277		 * When kern.ipc.soqlencomp is set to 1, so_qlen
278		 * represents only the completed queue.  Since we
279		 * cannot let the incomplete queue goes unbounded
280		 * (in case of SYN flood), we cap the incomplete
281		 * queue length to at most somaxconn, and use that
282		 * as so_qlen so that we fail immediately below.
283		 */
284		so_qlen = head->so_qlen - head->so_incqlen;
285		if (head->so_incqlen > somaxconn)
286			so_qlen = somaxconn;
287	}
288
289	if (so_qlen >=
290	    (soqlimitcompat ? head->so_qlimit : (3 * head->so_qlimit / 2)))
291		return ((struct socket *)0);
292	so = soalloc(1, head->so_proto->pr_domain->dom_family,
293	    head->so_type);
294	if (so == NULL)
295		return ((struct socket *)0);
296	/* check if head was closed during the soalloc */
297	if (head->so_proto == NULL) {
298		sodealloc(so);
299		return ((struct socket *)0);
300	}
301
302	so->so_type = head->so_type;
303	so->so_options = head->so_options &~ SO_ACCEPTCONN;
304	so->so_linger = head->so_linger;
305	so->so_state = head->so_state | SS_NOFDREF;
306	so->so_proto = head->so_proto;
307	so->so_timeo = head->so_timeo;
308	so->so_pgid  = head->so_pgid;
309	kauth_cred_ref(head->so_cred);
310	so->so_cred = head->so_cred;
311	so->last_pid = head->last_pid;
312	so->last_upid = head->last_upid;
313	/* inherit socket options stored in so_flags */
314	so->so_flags = head->so_flags & (SOF_NOSIGPIPE |
315					 SOF_NOADDRAVAIL |
316					 SOF_REUSESHAREUID |
317					 SOF_NOTIFYCONFLICT |
318					 SOF_BINDRANDOMPORT |
319					 SOF_NPX_SETOPTSHUT |
320					 SOF_NODEFUNCT |
321					 SOF_PRIVILEGED_TRAFFIC_CLASS|
322					 SOF_NOTSENT_LOWAT |
323					 SOF_USELRO);
324	so->so_usecount = 1;
325	so->next_lock_lr = 0;
326	so->next_unlock_lr = 0;
327
328#ifdef __APPLE__
329	so->so_rcv.sb_flags |= SB_RECV;	/* XXX */
330	so->so_rcv.sb_so = so->so_snd.sb_so = so;
331	TAILQ_INIT(&so->so_evlist);
332#endif
333
334#if CONFIG_MACF_SOCKET
335	mac_socket_label_associate_accept(head, so);
336#endif
337
338	/* inherit traffic management properties of listener */
339	so->so_traffic_mgt_flags = head->so_traffic_mgt_flags & (TRAFFIC_MGT_SO_BACKGROUND);
340	so->so_background_thread = head->so_background_thread;
341	so->so_traffic_class = head->so_traffic_class;
342
343	if (soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat)) {
344		sodealloc(so);
345		return ((struct socket *)0);
346	}
347	so->so_rcv.sb_flags |= (head->so_rcv.sb_flags & SB_USRSIZE);
348	so->so_snd.sb_flags |= (head->so_snd.sb_flags & SB_USRSIZE);
349
350	/*
351	 * Must be done with head unlocked to avoid deadlock
352	 * for protocol with per socket mutexes.
353	 */
354	if (head->so_proto->pr_unlock)
355		socket_unlock(head, 0);
356	if (((*so->so_proto->pr_usrreqs->pru_attach)(so, 0, NULL) != 0) ||
357	    error) {
358		sodealloc(so);
359		if (head->so_proto->pr_unlock)
360			socket_lock(head, 0);
361		return ((struct socket *)0);
362	}
363	if (head->so_proto->pr_unlock) {
364		socket_lock(head, 0);
365		/* Radar 7385998 Recheck that the head is still accepting
366		 * to avoid race condition when head is getting closed.
367		 */
368		if ((head->so_options & SO_ACCEPTCONN) == 0) {
369			so->so_state &= ~SS_NOFDREF;
370			soclose(so);
371			return ((struct socket *)0);
372		}
373	}
374
375#ifdef __APPLE__
376	so->so_proto->pr_domain->dom_refs++;
377#endif
378	/* Insert in head appropriate lists */
379	so->so_head = head;
380
381	/* Since this socket is going to be inserted into the incomp
382	 * queue, it can be picked up by another thread in
383	 * tcp_dropdropablreq to get dropped before it is setup..
384	 * To prevent this race, set in-progress flag which can be
385	 * cleared later
386	 */
387	so->so_flags |= SOF_INCOMP_INPROGRESS;
388
389	if (connstatus) {
390		TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
391		so->so_state |= SS_COMP;
392	} else {
393		TAILQ_INSERT_TAIL(&head->so_incomp, so, so_list);
394		so->so_state |= SS_INCOMP;
395		head->so_incqlen++;
396	}
397	head->so_qlen++;
398
399#ifdef __APPLE__
400	/* Attach socket filters for this protocol */
401	sflt_initsock(so);
402#endif
403
404	if (connstatus) {
405		so->so_state |= connstatus;
406		sorwakeup(head);
407		wakeup((caddr_t)&head->so_timeo);
408	}
409	return (so);
410}
411
412
413struct socket *
414sonewconn(struct socket *head, int connstatus, const struct sockaddr *from)
415{
416	int error = sflt_connectin(head, from);
417	if (error) {
418		return (NULL);
419	}
420
421	return (sonewconn_internal(head, connstatus));
422}
423
424/*
425 * Socantsendmore indicates that no more data will be sent on the
426 * socket; it would normally be applied to a socket when the user
427 * informs the system that no more data is to be sent, by the protocol
428 * code (in case PRU_SHUTDOWN).  Socantrcvmore indicates that no more data
429 * will be received, and will normally be applied to the socket by a
430 * protocol when it detects that the peer will send no more data.
431 * Data queued for reading in the socket may yet be read.
432 */
433
434void
435socantsendmore(struct socket *so)
436{
437	so->so_state |= SS_CANTSENDMORE;
438	soevent(so, SO_FILT_HINT_LOCKED);
439	sflt_notify(so, sock_evt_cantsendmore, NULL);
440	sowwakeup(so);
441}
442
443void
444socantrcvmore(struct socket *so)
445{
446	so->so_state |= SS_CANTRCVMORE;
447	soevent(so, SO_FILT_HINT_LOCKED);
448	sflt_notify(so, sock_evt_cantrecvmore, NULL);
449	sorwakeup(so);
450}
451
452/*
453 * Wait for data to arrive at/drain from a socket buffer.
454 *
455 * Returns:	0			Success
456 *		EBADF
457 *	msleep:EINTR
458 */
459int
460sbwait(struct sockbuf *sb)
461{
462	int error = 0;
463	uintptr_t lr_saved;
464	struct socket *so = sb->sb_so;
465	lck_mtx_t *mutex_held;
466	struct timespec ts;
467
468	lr_saved = (uintptr_t) __builtin_return_address(0);
469
470	if (so->so_proto->pr_getlock != NULL)
471		mutex_held = (*so->so_proto->pr_getlock)(so, 0);
472	else
473		mutex_held = so->so_proto->pr_domain->dom_mtx;
474	lck_mtx_assert(mutex_held, LCK_MTX_ASSERT_OWNED);
475
476	sb->sb_flags |= SB_WAIT;
477
478	if (so->so_usecount < 1)
479		panic("sbwait: so=%p refcount=%d\n", so, so->so_usecount);
480	ts.tv_sec = sb->sb_timeo.tv_sec;
481	ts.tv_nsec = sb->sb_timeo.tv_usec * 1000;
482	error = msleep((caddr_t)&sb->sb_cc, mutex_held,
483	    (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH, "sbwait", &ts);
484
485	lck_mtx_assert(mutex_held, LCK_MTX_ASSERT_OWNED);
486
487	if (so->so_usecount < 1)
488		panic("sbwait: so=%p refcount=%d\n", so, so->so_usecount);
489
490	if ((so->so_state & SS_DRAINING) || (so->so_flags & SOF_DEFUNCT)) {
491		error = EBADF;
492		if (so->so_flags & SOF_DEFUNCT) {
493			SODEFUNCTLOG(("%s[%d]: defunct so %p [%d,%d] (%d)\n",
494			    __func__, proc_selfpid(), so, INP_SOCKAF(so),
495			    INP_SOCKTYPE(so), error));
496		}
497	}
498
499	return (error);
500}
501
502/*
503 * Lock a sockbuf already known to be locked;
504 * return any error returned from sleep (EINTR).
505 *
506 * Returns:	0			Success
507 *		EINTR
508 */
509int
510sb_lock(struct sockbuf *sb)
511{
512	struct socket *so = sb->sb_so;
513	lck_mtx_t *mutex_held;
514	int error = 0;
515
516	if (so == NULL)
517		panic("sb_lock: null so back pointer sb=%p\n", sb);
518
519	while (sb->sb_flags & SB_LOCK) {
520		sb->sb_flags |= SB_WANT;
521
522		if (so->so_proto->pr_getlock != NULL)
523			mutex_held = (*so->so_proto->pr_getlock)(so, 0);
524		else
525			mutex_held = so->so_proto->pr_domain->dom_mtx;
526		lck_mtx_assert(mutex_held, LCK_MTX_ASSERT_OWNED);
527
528		if (so->so_usecount < 1)
529			panic("sb_lock: so=%p refcount=%d\n", so,
530			    so->so_usecount);
531
532		error = msleep((caddr_t)&sb->sb_flags, mutex_held,
533		    (sb->sb_flags & SB_NOINTR) ? PSOCK : PSOCK | PCATCH,
534		    "sb_lock", 0);
535		if (so->so_usecount < 1)
536			panic("sb_lock: 2 so=%p refcount=%d\n", so,
537			    so->so_usecount);
538
539		if (error == 0 && (so->so_flags & SOF_DEFUNCT)) {
540			error = EBADF;
541			SODEFUNCTLOG(("%s[%d]: defunct so %p [%d,%d] (%d)\n",
542			    __func__, proc_selfpid(), so, INP_SOCKAF(so),
543			    INP_SOCKTYPE(so), error));
544		}
545
546		if (error)
547			return (error);
548	}
549	sb->sb_flags |= SB_LOCK;
550	return (0);
551}
552
553void
554sbwakeup(struct sockbuf *sb)
555{
556	if (sb->sb_flags & SB_WAIT) {
557		sb->sb_flags &= ~SB_WAIT;
558		wakeup((caddr_t)&sb->sb_cc);
559	}
560}
561
562/*
563 * Wakeup processes waiting on a socket buffer.
564 * Do asynchronous notification via SIGIO
565 * if the socket has the SS_ASYNC flag set.
566 */
567void
568sowakeup(struct socket *so, struct sockbuf *sb)
569{
570	if (so->so_flags & SOF_DEFUNCT) {
571		SODEFUNCTLOG(("%s[%d]: defunct so %p [%d,%d] si 0x%x, "
572		    "fl 0x%x [%s]\n", __func__, proc_selfpid(), so,
573		    INP_SOCKAF(so), INP_SOCKTYPE(so),
574		    (uint32_t)sb->sb_sel.si_flags, (uint16_t)sb->sb_flags,
575		    (sb->sb_flags & SB_RECV) ? "rcv" : "snd"));
576	}
577
578	sb->sb_flags &= ~SB_SEL;
579	selwakeup(&sb->sb_sel);
580	sbwakeup(sb);
581	if (so->so_state & SS_ASYNC) {
582		if (so->so_pgid < 0)
583			gsignal(-so->so_pgid, SIGIO);
584		else if (so->so_pgid > 0)
585			proc_signal(so->so_pgid, SIGIO);
586	}
587	if (sb->sb_flags & SB_KNOTE) {
588		KNOTE(&sb->sb_sel.si_note, SO_FILT_HINT_LOCKED);
589	}
590	if (sb->sb_flags & SB_UPCALL) {
591		void (*so_upcall)(struct socket *, caddr_t, int);
592		caddr_t so_upcallarg;
593
594		so_upcall = so->so_upcall;
595		so_upcallarg = so->so_upcallarg;
596		/* Let close know that we're about to do an upcall */
597		so->so_upcallusecount++;
598
599		socket_unlock(so, 0);
600		(*so_upcall)(so, so_upcallarg, M_DONTWAIT);
601		socket_lock(so, 0);
602
603		so->so_upcallusecount--;
604		/* Tell close that it's safe to proceed */
605		if (so->so_flags & SOF_CLOSEWAIT && so->so_upcallusecount == 0)
606			wakeup((caddr_t)&so->so_upcall);
607	}
608}
609
610/*
611 * Socket buffer (struct sockbuf) utility routines.
612 *
613 * Each socket contains two socket buffers: one for sending data and
614 * one for receiving data.  Each buffer contains a queue of mbufs,
615 * information about the number of mbufs and amount of data in the
616 * queue, and other fields allowing select() statements and notification
617 * on data availability to be implemented.
618 *
619 * Data stored in a socket buffer is maintained as a list of records.
620 * Each record is a list of mbufs chained together with the m_next
621 * field.  Records are chained together with the m_nextpkt field. The upper
622 * level routine soreceive() expects the following conventions to be
623 * observed when placing information in the receive buffer:
624 *
625 * 1. If the protocol requires each message be preceded by the sender's
626 *    name, then a record containing that name must be present before
627 *    any associated data (mbuf's must be of type MT_SONAME).
628 * 2. If the protocol supports the exchange of ``access rights'' (really
629 *    just additional data associated with the message), and there are
630 *    ``rights'' to be received, then a record containing this data
631 *    should be present (mbuf's must be of type MT_RIGHTS).
632 * 3. If a name or rights record exists, then it must be followed by
633 *    a data record, perhaps of zero length.
634 *
635 * Before using a new socket structure it is first necessary to reserve
636 * buffer space to the socket, by calling sbreserve().  This should commit
637 * some of the available buffer space in the system buffer pool for the
638 * socket (currently, it does nothing but enforce limits).  The space
639 * should be released by calling sbrelease() when the socket is destroyed.
640 */
641
642/*
643 * Returns:	0			Success
644 *		ENOBUFS
645 */
646int
647soreserve(struct socket *so, u_int32_t sndcc, u_int32_t rcvcc)
648{
649
650	if (sbreserve(&so->so_snd, sndcc) == 0)
651		goto bad;
652	else
653		so->so_snd.sb_idealsize = sndcc;
654
655	if (sbreserve(&so->so_rcv, rcvcc) == 0)
656		goto bad2;
657	else
658		so->so_rcv.sb_idealsize = rcvcc;
659
660	if (so->so_rcv.sb_lowat == 0)
661		so->so_rcv.sb_lowat = 1;
662	if (so->so_snd.sb_lowat == 0)
663		so->so_snd.sb_lowat = MCLBYTES;
664	if (so->so_snd.sb_lowat > so->so_snd.sb_hiwat)
665		so->so_snd.sb_lowat = so->so_snd.sb_hiwat;
666	return (0);
667bad2:
668#ifdef __APPLE__
669	selthreadclear(&so->so_snd.sb_sel);
670#endif
671	sbrelease(&so->so_snd);
672bad:
673	return (ENOBUFS);
674}
675
676/*
677 * Allot mbufs to a sockbuf.
678 * Attempt to scale mbmax so that mbcnt doesn't become limiting
679 * if buffering efficiency is near the normal case.
680 */
681int
682sbreserve(struct sockbuf *sb, u_int32_t cc)
683{
684	if ((u_quad_t)cc > (u_quad_t)sb_max * MCLBYTES / (MSIZE + MCLBYTES))
685		return (0);
686	sb->sb_hiwat = cc;
687	sb->sb_mbmax = min(cc * sb_efficiency, sb_max);
688	if (sb->sb_lowat > sb->sb_hiwat)
689		sb->sb_lowat = sb->sb_hiwat;
690	return (1);
691}
692
693/*
694 * Free mbufs held by a socket, and reserved mbuf space.
695 */
696/*  WARNING needs to do selthreadclear() before calling this */
697void
698sbrelease(struct sockbuf *sb)
699{
700	sbflush(sb);
701	sb->sb_hiwat = 0;
702	sb->sb_mbmax = 0;
703}
704
705/*
706 * Routines to add and remove
707 * data from an mbuf queue.
708 *
709 * The routines sbappend() or sbappendrecord() are normally called to
710 * append new mbufs to a socket buffer, after checking that adequate
711 * space is available, comparing the function sbspace() with the amount
712 * of data to be added.  sbappendrecord() differs from sbappend() in
713 * that data supplied is treated as the beginning of a new record.
714 * To place a sender's address, optional access rights, and data in a
715 * socket receive buffer, sbappendaddr() should be used.  To place
716 * access rights and data in a socket receive buffer, sbappendrights()
717 * should be used.  In either case, the new data begins a new record.
718 * Note that unlike sbappend() and sbappendrecord(), these routines check
719 * for the caller that there will be enough space to store the data.
720 * Each fails if there is not enough space, or if it cannot find mbufs
721 * to store additional information in.
722 *
723 * Reliable protocols may use the socket send buffer to hold data
724 * awaiting acknowledgement.  Data is normally copied from a socket
725 * send buffer in a protocol with m_copy for output to a peer,
726 * and then removing the data from the socket buffer with sbdrop()
727 * or sbdroprecord() when the data is acknowledged by the peer.
728 */
729
730/*
731 * Append mbuf chain m to the last record in the
732 * socket buffer sb.  The additional space associated
733 * the mbuf chain is recorded in sb.  Empty mbufs are
734 * discarded and mbufs are compacted where possible.
735 */
736int
737sbappend(struct sockbuf *sb, struct mbuf *m)
738{
739	struct socket *so = sb->sb_so;
740
741	if (m == NULL || (sb->sb_flags & SB_DROP)) {
742		if (m != NULL)
743			m_freem(m);
744		return (0);
745	}
746
747	SBLASTRECORDCHK(sb, "sbappend 1");
748
749	if (sb->sb_lastrecord != NULL && (sb->sb_mbtail->m_flags & M_EOR))
750		return (sbappendrecord(sb, m));
751
752	if (sb->sb_flags & SB_RECV) {
753		int error = sflt_data_in(so, NULL, &m, NULL, 0);
754		SBLASTRECORDCHK(sb, "sbappend 2");
755		if (error != 0) {
756			if (error != EJUSTRETURN)
757				m_freem(m);
758			return (0);
759		}
760	}
761
762	/* If this is the first record, it's also the last record */
763	if (sb->sb_lastrecord == NULL)
764		sb->sb_lastrecord = m;
765
766	sbcompress(sb, m, sb->sb_mbtail);
767	SBLASTRECORDCHK(sb, "sbappend 3");
768	return (1);
769}
770
771/*
772 * Similar to sbappend, except that this is optimized for stream sockets.
773 */
774int
775sbappendstream(struct sockbuf *sb, struct mbuf *m)
776{
777	struct socket *so = sb->sb_so;
778
779	if (m->m_nextpkt != NULL || (sb->sb_mb != sb->sb_lastrecord))
780		panic("sbappendstream: nexpkt %p || mb %p != lastrecord %p\n",
781		    m->m_nextpkt, sb->sb_mb, sb->sb_lastrecord);
782
783	SBLASTMBUFCHK(sb, __func__);
784
785	if (m == NULL || (sb->sb_flags & SB_DROP)) {
786		if (m != NULL)
787			m_freem(m);
788		return (0);
789	}
790
791	if (sb->sb_flags & SB_RECV) {
792		int error = sflt_data_in(so, NULL, &m, NULL, 0);
793		SBLASTRECORDCHK(sb, "sbappendstream 1");
794		if (error != 0) {
795			if (error != EJUSTRETURN)
796				m_freem(m);
797			return (0);
798		}
799	}
800
801	sbcompress(sb, m, sb->sb_mbtail);
802	sb->sb_lastrecord = sb->sb_mb;
803	SBLASTRECORDCHK(sb, "sbappendstream 2");
804	return (1);
805}
806
807#ifdef SOCKBUF_DEBUG
808void
809sbcheck(struct sockbuf *sb)
810{
811	struct mbuf *m;
812	struct mbuf *n = 0;
813	u_int32_t len = 0, mbcnt = 0;
814	lck_mtx_t *mutex_held;
815
816	if (sb->sb_so->so_proto->pr_getlock != NULL)
817		mutex_held = (*sb->sb_so->so_proto->pr_getlock)(sb->sb_so, 0);
818	else
819		mutex_held = sb->sb_so->so_proto->pr_domain->dom_mtx;
820
821	lck_mtx_assert(mutex_held, LCK_MTX_ASSERT_OWNED);
822
823	if (sbchecking == 0)
824		return;
825
826	for (m = sb->sb_mb; m; m = n) {
827		n = m->m_nextpkt;
828		for (; m; m = m->m_next) {
829			len += m->m_len;
830			mbcnt += MSIZE;
831			/* XXX pretty sure this is bogus */
832			if (m->m_flags & M_EXT)
833				mbcnt += m->m_ext.ext_size;
834		}
835	}
836	if (len != sb->sb_cc || mbcnt != sb->sb_mbcnt) {
837		panic("cc %ld != %ld || mbcnt %ld != %ld\n", len, sb->sb_cc,
838		    mbcnt, sb->sb_mbcnt);
839	}
840}
841#endif
842
843void
844sblastrecordchk(struct sockbuf *sb, const char *where)
845{
846	struct mbuf *m = sb->sb_mb;
847
848	while (m && m->m_nextpkt)
849		m = m->m_nextpkt;
850
851	if (m != sb->sb_lastrecord) {
852		printf("sblastrecordchk: mb %p lastrecord %p last %p\n",
853		    sb->sb_mb, sb->sb_lastrecord, m);
854		printf("packet chain:\n");
855		for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt)
856			printf("\t%p\n", m);
857		panic("sblastrecordchk from %s", where);
858	}
859}
860
861void
862sblastmbufchk(struct sockbuf *sb, const char *where)
863{
864	struct mbuf *m = sb->sb_mb;
865	struct mbuf *n;
866
867	while (m && m->m_nextpkt)
868		m = m->m_nextpkt;
869
870	while (m && m->m_next)
871		m = m->m_next;
872
873	if (m != sb->sb_mbtail) {
874		printf("sblastmbufchk: mb %p mbtail %p last %p\n",
875		    sb->sb_mb, sb->sb_mbtail, m);
876		printf("packet tree:\n");
877		for (m = sb->sb_mb; m != NULL; m = m->m_nextpkt) {
878			printf("\t");
879			for (n = m; n != NULL; n = n->m_next)
880				printf("%p ", n);
881			printf("\n");
882		}
883		panic("sblastmbufchk from %s", where);
884	}
885}
886
887/*
888 * Similar to sbappend, except the mbuf chain begins a new record.
889 */
890int
891sbappendrecord(struct sockbuf *sb, struct mbuf *m0)
892{
893	struct mbuf *m;
894	int space = 0;
895
896	if (m0 == NULL || (sb->sb_flags & SB_DROP)) {
897		if (m0 != NULL)
898			m_freem(m0);
899		return (0);
900	}
901
902	for (m = m0; m != NULL; m = m->m_next)
903		space += m->m_len;
904
905	if (space > sbspace(sb) && !(sb->sb_flags & SB_UNIX)) {
906		m_freem(m0);
907		return (0);
908	}
909
910	if (sb->sb_flags & SB_RECV) {
911		int error = sflt_data_in(sb->sb_so, NULL, &m0, NULL,
912		    sock_data_filt_flag_record);
913		if (error != 0) {
914			SBLASTRECORDCHK(sb, "sbappendrecord 1");
915			if (error != EJUSTRETURN)
916				m_freem(m0);
917			return (0);
918		}
919	}
920
921	/*
922	 * Note this permits zero length records.
923	 */
924	sballoc(sb, m0);
925	SBLASTRECORDCHK(sb, "sbappendrecord 2");
926	if (sb->sb_lastrecord != NULL) {
927		sb->sb_lastrecord->m_nextpkt = m0;
928	}  else {
929		sb->sb_mb = m0;
930	}
931	sb->sb_lastrecord = m0;
932	sb->sb_mbtail = m0;
933
934	m = m0->m_next;
935	m0->m_next = 0;
936	if (m && (m0->m_flags & M_EOR)) {
937		m0->m_flags &= ~M_EOR;
938		m->m_flags |= M_EOR;
939	}
940	sbcompress(sb, m, m0);
941	SBLASTRECORDCHK(sb, "sbappendrecord 3");
942	return (1);
943}
944
945/*
946 * As above except that OOB data
947 * is inserted at the beginning of the sockbuf,
948 * but after any other OOB data.
949 */
950int
951sbinsertoob(struct sockbuf *sb, struct mbuf *m0)
952{
953	struct mbuf *m;
954	struct mbuf **mp;
955
956	if (m0 == 0)
957		return (0);
958
959	SBLASTRECORDCHK(sb, "sbinsertoob 1");
960
961	if ((sb->sb_flags & SB_RECV) != 0) {
962		int error = sflt_data_in(sb->sb_so, NULL, &m0, NULL,
963		    sock_data_filt_flag_oob);
964
965		SBLASTRECORDCHK(sb, "sbinsertoob 2");
966		if (error) {
967			if (error != EJUSTRETURN) {
968				m_freem(m0);
969			}
970			return (0);
971		}
972	}
973
974	for (mp = &sb->sb_mb; *mp; mp = &((*mp)->m_nextpkt)) {
975		m = *mp;
976again:
977		switch (m->m_type) {
978
979		case MT_OOBDATA:
980			continue;		/* WANT next train */
981
982		case MT_CONTROL:
983			m = m->m_next;
984			if (m)
985				goto again;	/* inspect THIS train further */
986		}
987		break;
988	}
989	/*
990	 * Put the first mbuf on the queue.
991	 * Note this permits zero length records.
992	 */
993	sballoc(sb, m0);
994	m0->m_nextpkt = *mp;
995	if (*mp == NULL) {
996		/* m0 is actually the new tail */
997		sb->sb_lastrecord = m0;
998	}
999	*mp = m0;
1000	m = m0->m_next;
1001	m0->m_next = 0;
1002	if (m && (m0->m_flags & M_EOR)) {
1003		m0->m_flags &= ~M_EOR;
1004		m->m_flags |= M_EOR;
1005	}
1006	sbcompress(sb, m, m0);
1007	SBLASTRECORDCHK(sb, "sbinsertoob 3");
1008	return (1);
1009}
1010
1011/*
1012 * Append address and data, and optionally, control (ancillary) data
1013 * to the receive queue of a socket.  If present,
1014 * m0 must include a packet header with total length.
1015 * Returns 0 if no space in sockbuf or insufficient mbufs.
1016 *
1017 * Returns:	0			No space/out of mbufs
1018 *		1			Success
1019 */
1020static int
1021sbappendaddr_internal(struct sockbuf *sb, struct sockaddr *asa,
1022    struct mbuf *m0, struct mbuf *control)
1023{
1024	struct mbuf *m, *n, *nlast;
1025	int space = asa->sa_len;
1026
1027	if (m0 && (m0->m_flags & M_PKTHDR) == 0)
1028		panic("sbappendaddr");
1029
1030	if (m0)
1031		space += m0->m_pkthdr.len;
1032	for (n = control; n; n = n->m_next) {
1033		space += n->m_len;
1034		if (n->m_next == 0)	/* keep pointer to last control buf */
1035			break;
1036	}
1037	if (space > sbspace(sb))
1038		return (0);
1039	if (asa->sa_len > MLEN)
1040		return (0);
1041	MGET(m, M_DONTWAIT, MT_SONAME);
1042	if (m == 0)
1043		return (0);
1044	m->m_len = asa->sa_len;
1045	bcopy((caddr_t)asa, mtod(m, caddr_t), asa->sa_len);
1046	if (n)
1047		n->m_next = m0;		/* concatenate data to control */
1048	else
1049		control = m0;
1050	m->m_next = control;
1051
1052	SBLASTRECORDCHK(sb, "sbappendadddr 1");
1053
1054	for (n = m; n->m_next != NULL; n = n->m_next)
1055		sballoc(sb, n);
1056	sballoc(sb, n);
1057	nlast = n;
1058
1059	if (sb->sb_lastrecord != NULL) {
1060		sb->sb_lastrecord->m_nextpkt = m;
1061	} else {
1062		sb->sb_mb = m;
1063	}
1064	sb->sb_lastrecord = m;
1065	sb->sb_mbtail = nlast;
1066
1067	SBLASTMBUFCHK(sb, __func__);
1068	SBLASTRECORDCHK(sb, "sbappendadddr 2");
1069
1070	postevent(0, sb, EV_RWBYTES);
1071	return (1);
1072}
1073
1074/*
1075 * Returns:	0			Error: No space/out of mbufs/etc.
1076 *		1			Success
1077 *
1078 * Imputed:	(*error_out)		errno for error
1079 *		ENOBUFS
1080 *	sflt_data_in:???		[whatever a filter author chooses]
1081 */
1082int
1083sbappendaddr(struct sockbuf *sb, struct sockaddr *asa, struct mbuf *m0,
1084    struct mbuf *control, int *error_out)
1085{
1086	int result = 0;
1087	boolean_t sb_unix = (sb->sb_flags & SB_UNIX);
1088
1089	if (error_out)
1090		*error_out = 0;
1091
1092	if (m0 && (m0->m_flags & M_PKTHDR) == 0)
1093		panic("sbappendaddrorfree");
1094
1095	if (sb->sb_flags & SB_DROP) {
1096		if (m0 != NULL)
1097			m_freem(m0);
1098		if (control != NULL && !sb_unix)
1099			m_freem(control);
1100		if (error_out != NULL)
1101			*error_out = EINVAL;
1102		return (0);
1103	}
1104
1105	/* Call socket data in filters */
1106	if ((sb->sb_flags & SB_RECV) != 0) {
1107		int error;
1108		error = sflt_data_in(sb->sb_so, asa, &m0, &control, 0);
1109		SBLASTRECORDCHK(sb, __func__);
1110		if (error) {
1111			if (error != EJUSTRETURN) {
1112				if (m0)
1113					m_freem(m0);
1114				if (control != NULL && !sb_unix)
1115					m_freem(control);
1116				if (error_out)
1117					*error_out = error;
1118			}
1119			return (0);
1120		}
1121	}
1122
1123	result = sbappendaddr_internal(sb, asa, m0, control);
1124	if (result == 0) {
1125		if (m0)
1126			m_freem(m0);
1127		if (control != NULL && !sb_unix)
1128			m_freem(control);
1129		if (error_out)
1130			*error_out = ENOBUFS;
1131	}
1132
1133	return (result);
1134}
1135
1136static int
1137sbappendcontrol_internal(struct sockbuf *sb, struct mbuf *m0,
1138    struct mbuf *control)
1139{
1140	struct mbuf *m, *mlast, *n;
1141	int space = 0;
1142
1143	if (control == 0)
1144		panic("sbappendcontrol");
1145
1146	for (m = control; ; m = m->m_next) {
1147		space += m->m_len;
1148		if (m->m_next == 0)
1149			break;
1150	}
1151	n = m;			/* save pointer to last control buffer */
1152	for (m = m0; m; m = m->m_next)
1153		space += m->m_len;
1154	if (space > sbspace(sb) && !(sb->sb_flags & SB_UNIX))
1155		return (0);
1156	n->m_next = m0;			/* concatenate data to control */
1157
1158	SBLASTRECORDCHK(sb, "sbappendcontrol 1");
1159
1160	for (m = control; m->m_next != NULL; m = m->m_next)
1161		sballoc(sb, m);
1162	sballoc(sb, m);
1163	mlast = m;
1164
1165	if (sb->sb_lastrecord != NULL) {
1166		sb->sb_lastrecord->m_nextpkt = control;
1167	} else {
1168		sb->sb_mb = control;
1169	}
1170	sb->sb_lastrecord = control;
1171	sb->sb_mbtail = mlast;
1172
1173	SBLASTMBUFCHK(sb, __func__);
1174	SBLASTRECORDCHK(sb, "sbappendcontrol 2");
1175
1176	postevent(0, sb, EV_RWBYTES);
1177	return (1);
1178}
1179
1180int
1181sbappendcontrol(struct sockbuf *sb, struct mbuf	*m0, struct mbuf *control,
1182    int *error_out)
1183{
1184	int result = 0;
1185	boolean_t sb_unix = (sb->sb_flags & SB_UNIX);
1186
1187	if (error_out)
1188		*error_out = 0;
1189
1190	if (sb->sb_flags & SB_DROP) {
1191		if (m0 != NULL)
1192			m_freem(m0);
1193		if (control != NULL && !sb_unix)
1194			m_freem(control);
1195		if (error_out != NULL)
1196			*error_out = EINVAL;
1197		return (0);
1198	}
1199
1200	if (sb->sb_flags & SB_RECV) {
1201		int error;
1202
1203		error = sflt_data_in(sb->sb_so, NULL, &m0, &control, 0);
1204		SBLASTRECORDCHK(sb, __func__);
1205		if (error) {
1206			if (error != EJUSTRETURN) {
1207				if (m0)
1208					m_freem(m0);
1209				if (control != NULL && !sb_unix)
1210					m_freem(control);
1211				if (error_out)
1212					*error_out = error;
1213			}
1214			return (0);
1215		}
1216	}
1217
1218	result = sbappendcontrol_internal(sb, m0, control);
1219	if (result == 0) {
1220		if (m0)
1221			m_freem(m0);
1222		if (control != NULL && !sb_unix)
1223			m_freem(control);
1224		if (error_out)
1225			*error_out = ENOBUFS;
1226	}
1227
1228	return (result);
1229}
1230
1231/*
1232 * Compress mbuf chain m into the socket
1233 * buffer sb following mbuf n.  If n
1234 * is null, the buffer is presumed empty.
1235 */
1236static inline void
1237sbcompress(struct sockbuf *sb, struct mbuf *m, struct mbuf *n)
1238{
1239	int eor = 0;
1240	struct mbuf *o;
1241
1242	if (m == NULL) {
1243		/* There is nothing to compress; just update the tail */
1244		for (; n->m_next != NULL; n = n->m_next)
1245			;
1246		sb->sb_mbtail = n;
1247		goto done;
1248	}
1249
1250	while (m) {
1251		eor |= m->m_flags & M_EOR;
1252		if (m->m_len == 0 && (eor == 0 ||
1253		    (((o = m->m_next) || (o = n)) && o->m_type == m->m_type))) {
1254			if (sb->sb_lastrecord == m)
1255				sb->sb_lastrecord = m->m_next;
1256			m = m_free(m);
1257			continue;
1258		}
1259		if (n && (n->m_flags & M_EOR) == 0 &&
1260#ifndef __APPLE__
1261		    M_WRITABLE(n) &&
1262#endif
1263		    m->m_len <= MCLBYTES / 4 && /* XXX: Don't copy too much */
1264		    m->m_len <= M_TRAILINGSPACE(n) &&
1265		    n->m_type == m->m_type) {
1266			bcopy(mtod(m, caddr_t), mtod(n, caddr_t) + n->m_len,
1267			    (unsigned)m->m_len);
1268			n->m_len += m->m_len;
1269			sb->sb_cc += m->m_len;
1270			if (m->m_type != MT_DATA && m->m_type != MT_HEADER &&
1271				m->m_type != MT_OOBDATA)
1272				/* XXX: Probably don't need.*/
1273				sb->sb_ctl += m->m_len;
1274			m = m_free(m);
1275			continue;
1276		}
1277		if (n)
1278			n->m_next = m;
1279		else
1280			sb->sb_mb = m;
1281		sb->sb_mbtail = m;
1282		sballoc(sb, m);
1283		n = m;
1284		m->m_flags &= ~M_EOR;
1285		m = m->m_next;
1286		n->m_next = 0;
1287	}
1288	if (eor) {
1289		if (n)
1290			n->m_flags |= eor;
1291		else
1292			printf("semi-panic: sbcompress\n");
1293	}
1294done:
1295	SBLASTMBUFCHK(sb, __func__);
1296	postevent(0, sb, EV_RWBYTES);
1297}
1298
1299void
1300sb_empty_assert(struct sockbuf *sb, const char *where)
1301{
1302	if (!(sb->sb_cc == 0 && sb->sb_mb == NULL && sb->sb_mbcnt == 0 &&
1303	    sb->sb_mbtail == NULL && sb->sb_lastrecord == NULL)) {
1304		panic("%s: sb %p so %p cc %d mbcnt %d mb %p mbtail %p "
1305		    "lastrecord %p\n", where, sb, sb->sb_so, sb->sb_cc,
1306		    sb->sb_mbcnt, sb->sb_mb, sb->sb_mbtail, sb->sb_lastrecord);
1307		/* NOTREACHED */
1308	}
1309}
1310
1311/*
1312 * Free all mbufs in a sockbuf.
1313 * Check that all resources are reclaimed.
1314 */
1315void
1316sbflush(struct sockbuf *sb)
1317{
1318	if (sb->sb_so == NULL)
1319		panic("sbflush sb->sb_so already null sb=%p\n", sb);
1320	(void) sblock(sb, M_WAIT);
1321	while (sb->sb_mbcnt) {
1322		/*
1323		 * Don't call sbdrop(sb, 0) if the leading mbuf is non-empty:
1324		 * we would loop forever. Panic instead.
1325		 */
1326		if (!sb->sb_cc && (sb->sb_mb == NULL || sb->sb_mb->m_len))
1327			break;
1328		sbdrop(sb, (int)sb->sb_cc);
1329	}
1330	sb_empty_assert(sb, __func__);
1331	postevent(0, sb, EV_RWBYTES);
1332	sbunlock(sb, 1);	/* keep socket locked */
1333
1334}
1335
1336/*
1337 * Drop data from (the front of) a sockbuf.
1338 * use m_freem_list to free the mbuf structures
1339 * under a single lock... this is done by pruning
1340 * the top of the tree from the body by keeping track
1341 * of where we get to in the tree and then zeroing the
1342 * two pertinent pointers m_nextpkt and m_next
1343 * the socket buffer is then updated to point at the new
1344 * top of the tree and the pruned area is released via
1345 * m_freem_list.
1346 */
1347void
1348sbdrop(struct sockbuf *sb, int len)
1349{
1350	struct mbuf *m, *free_list, *ml;
1351	struct mbuf *next, *last;
1352
1353	KERNEL_DEBUG((DBG_FNC_SBDROP | DBG_FUNC_START), sb, len, 0, 0, 0);
1354
1355	next = (m = sb->sb_mb) ? m->m_nextpkt : 0;
1356	free_list = last = m;
1357	ml = (struct mbuf *)0;
1358
1359	while (len > 0) {
1360		if (m == 0) {
1361			if (next == 0) {
1362				/*
1363				 * temporarily replacing this panic with printf
1364				 * because it occurs occasionally when closing
1365				 * a socket when there is no harm in ignoring
1366				 * it. This problem will be investigated
1367				 * further.
1368				 */
1369				/* panic("sbdrop"); */
1370				printf("sbdrop - count not zero\n");
1371				len = 0;
1372				/*
1373				 * zero the counts. if we have no mbufs,
1374				 * we have no data (PR-2986815)
1375				 */
1376				sb->sb_cc = 0;
1377				sb->sb_mbcnt = 0;
1378				break;
1379			}
1380			m = last = next;
1381			next = m->m_nextpkt;
1382			continue;
1383		}
1384		if (m->m_len > len) {
1385			m->m_len -= len;
1386			m->m_data += len;
1387			sb->sb_cc -= len;
1388			if (m->m_type != MT_DATA && m->m_type != MT_HEADER &&
1389				m->m_type != MT_OOBDATA)
1390				sb->sb_ctl -= len;
1391			break;
1392		}
1393		len -= m->m_len;
1394		sbfree(sb, m);
1395
1396		ml = m;
1397		m = m->m_next;
1398	}
1399	while (m && m->m_len == 0) {
1400		sbfree(sb, m);
1401
1402		ml = m;
1403		m = m->m_next;
1404	}
1405	if (ml) {
1406		ml->m_next = (struct mbuf *)0;
1407		last->m_nextpkt = (struct mbuf *)0;
1408		m_freem_list(free_list);
1409	}
1410	if (m) {
1411		sb->sb_mb = m;
1412		m->m_nextpkt = next;
1413	} else {
1414		sb->sb_mb = next;
1415	}
1416
1417	/*
1418	 * First part is an inline SB_EMPTY_FIXUP().  Second part
1419	 * makes sure sb_lastrecord is up-to-date if we dropped
1420	 * part of the last record.
1421	 */
1422	m = sb->sb_mb;
1423	if (m == NULL) {
1424		sb->sb_mbtail = NULL;
1425		sb->sb_lastrecord = NULL;
1426	} else if (m->m_nextpkt == NULL) {
1427		sb->sb_lastrecord = m;
1428	}
1429
1430	postevent(0, sb, EV_RWBYTES);
1431
1432	KERNEL_DEBUG((DBG_FNC_SBDROP | DBG_FUNC_END), sb, 0, 0, 0, 0);
1433}
1434
1435/*
1436 * Drop a record off the front of a sockbuf
1437 * and move the next record to the front.
1438 */
1439void
1440sbdroprecord(struct sockbuf *sb)
1441{
1442	struct mbuf *m, *mn;
1443
1444	m = sb->sb_mb;
1445	if (m) {
1446		sb->sb_mb = m->m_nextpkt;
1447		do {
1448			sbfree(sb, m);
1449			MFREE(m, mn);
1450			m = mn;
1451		} while (m);
1452	}
1453	SB_EMPTY_FIXUP(sb);
1454	postevent(0, sb, EV_RWBYTES);
1455}
1456
1457/*
1458 * Create a "control" mbuf containing the specified data
1459 * with the specified type for presentation on a socket buffer.
1460 */
1461struct mbuf *
1462sbcreatecontrol(caddr_t p, int size, int type, int level)
1463{
1464	struct cmsghdr *cp;
1465	struct mbuf *m;
1466
1467	if (CMSG_SPACE((u_int)size) > MLEN)
1468		return ((struct mbuf *)NULL);
1469	if ((m = m_get(M_DONTWAIT, MT_CONTROL)) == NULL)
1470		return ((struct mbuf *)NULL);
1471	cp = mtod(m, struct cmsghdr *);
1472	VERIFY(IS_P2ALIGNED(cp, sizeof (u_int32_t)));
1473	/* XXX check size? */
1474	(void) memcpy(CMSG_DATA(cp), p, size);
1475	m->m_len = CMSG_SPACE(size);
1476	cp->cmsg_len = CMSG_LEN(size);
1477	cp->cmsg_level = level;
1478	cp->cmsg_type = type;
1479	return (m);
1480}
1481
1482struct mbuf**
1483sbcreatecontrol_mbuf(caddr_t p, int size, int type, int level, struct mbuf** mp)
1484{
1485	struct mbuf* m;
1486	struct cmsghdr *cp;
1487
1488	if (*mp == NULL){
1489		*mp = sbcreatecontrol(p, size, type, level);
1490		return mp;
1491	}
1492
1493	if (CMSG_SPACE((u_int)size) + (*mp)->m_len > MLEN){
1494		mp = &(*mp)->m_next;
1495		*mp = sbcreatecontrol(p, size, type, level);
1496		return mp;
1497	}
1498
1499	m = *mp;
1500
1501	cp = (struct cmsghdr *)(void *)(mtod(m, char *) + m->m_len);
1502	/* CMSG_SPACE ensures 32-bit alignment */
1503	VERIFY(IS_P2ALIGNED(cp, sizeof (u_int32_t)));
1504	m->m_len += CMSG_SPACE(size);
1505
1506	/* XXX check size? */
1507	(void) memcpy(CMSG_DATA(cp), p, size);
1508	cp->cmsg_len = CMSG_LEN(size);
1509	cp->cmsg_level = level;
1510	cp->cmsg_type = type;
1511
1512	return mp;
1513}
1514
1515
1516/*
1517 * Some routines that return EOPNOTSUPP for entry points that are not
1518 * supported by a protocol.  Fill in as needed.
1519 */
1520int
1521pru_abort_notsupp(__unused struct socket *so)
1522{
1523	return (EOPNOTSUPP);
1524}
1525
1526int
1527pru_accept_notsupp(__unused struct socket *so, __unused struct sockaddr **nam)
1528{
1529	return (EOPNOTSUPP);
1530}
1531
1532int
1533pru_attach_notsupp(__unused struct socket *so, __unused int proto,
1534    __unused struct proc *p)
1535{
1536	return (EOPNOTSUPP);
1537}
1538
1539int
1540pru_bind_notsupp(__unused struct socket *so, __unused struct sockaddr *nam,
1541    __unused struct proc *p)
1542{
1543	return (EOPNOTSUPP);
1544}
1545
1546int
1547pru_connect_notsupp(__unused struct socket *so, __unused struct sockaddr *nam,
1548    __unused struct proc *p)
1549{
1550	return (EOPNOTSUPP);
1551}
1552
1553int
1554pru_connect2_notsupp(__unused struct socket *so1, __unused struct socket *so2)
1555{
1556	return (EOPNOTSUPP);
1557}
1558
1559int
1560pru_control_notsupp(__unused struct socket *so, __unused u_long  cmd,
1561    __unused caddr_t data, __unused struct ifnet *ifp, __unused struct proc *p)
1562{
1563	return (EOPNOTSUPP);
1564}
1565
1566int
1567pru_detach_notsupp(__unused struct socket *so)
1568{
1569	return (EOPNOTSUPP);
1570}
1571
1572int
1573pru_disconnect_notsupp(__unused struct socket *so)
1574{
1575	return (EOPNOTSUPP);
1576}
1577
1578int
1579pru_listen_notsupp(__unused struct socket *so, __unused struct proc *p)
1580{
1581	return (EOPNOTSUPP);
1582}
1583
1584int
1585pru_peeraddr_notsupp(__unused struct socket *so, __unused struct sockaddr **nam)
1586{
1587	return (EOPNOTSUPP);
1588}
1589
1590int
1591pru_rcvd_notsupp(__unused struct socket *so, __unused int flags)
1592{
1593	return (EOPNOTSUPP);
1594}
1595
1596int
1597pru_rcvoob_notsupp(__unused struct socket *so, __unused struct mbuf *m,
1598    __unused int flags)
1599{
1600	return (EOPNOTSUPP);
1601}
1602
1603int
1604pru_send_notsupp(__unused struct socket *so, __unused int flags,
1605    __unused struct mbuf *m, __unused struct sockaddr *addr,
1606    __unused struct mbuf *control, __unused struct proc *p)
1607
1608{
1609	return (EOPNOTSUPP);
1610}
1611
1612
1613/*
1614 * This isn't really a ``null'' operation, but it's the default one
1615 * and doesn't do anything destructive.
1616 */
1617int
1618pru_sense_null(struct socket *so, void *ub, int isstat64)
1619{
1620	if (isstat64 != 0) {
1621		struct stat64 *sb64;
1622
1623		sb64 = (struct stat64 *)ub;
1624		sb64->st_blksize = so->so_snd.sb_hiwat;
1625	} else {
1626		struct stat *sb;
1627
1628		sb = (struct stat *)ub;
1629		sb->st_blksize = so->so_snd.sb_hiwat;
1630	}
1631
1632	return (0);
1633}
1634
1635
1636int
1637pru_sosend_notsupp(__unused struct socket *so, __unused struct sockaddr *addr,
1638    __unused struct uio *uio, __unused struct mbuf *top,
1639    __unused struct mbuf *control, __unused int flags)
1640
1641{
1642	return (EOPNOTSUPP);
1643}
1644
1645int
1646pru_soreceive_notsupp(__unused struct socket *so,
1647    __unused struct sockaddr **paddr,
1648    __unused struct uio *uio, __unused struct mbuf **mp0,
1649    __unused struct mbuf **controlp, __unused int *flagsp)
1650{
1651	return (EOPNOTSUPP);
1652}
1653
1654int
1655pru_shutdown_notsupp(__unused struct socket *so)
1656{
1657	return (EOPNOTSUPP);
1658}
1659
1660int
1661pru_sockaddr_notsupp(__unused struct socket *so, __unused struct sockaddr **nam)
1662{
1663	return (EOPNOTSUPP);
1664}
1665
1666int
1667pru_sopoll_notsupp(__unused struct socket *so, __unused int events,
1668    __unused kauth_cred_t cred, __unused void *wql)
1669{
1670	return (EOPNOTSUPP);
1671}
1672
1673
1674#ifdef __APPLE__
1675/*
1676 * The following are macros on BSD and functions on Darwin
1677 */
1678
1679/*
1680 * Do we need to notify the other side when I/O is possible?
1681 */
1682
1683int
1684sb_notify(struct sockbuf *sb)
1685{
1686	return ((sb->sb_flags &
1687	    (SB_WAIT|SB_SEL|SB_ASYNC|SB_UPCALL|SB_KNOTE)) != 0);
1688}
1689
1690/*
1691 * How much space is there in a socket buffer (so->so_snd or so->so_rcv)?
1692 * This is problematical if the fields are unsigned, as the space might
1693 * still be negative (cc > hiwat or mbcnt > mbmax).  Should detect
1694 * overflow and return 0.
1695 */
1696int
1697sbspace(struct sockbuf *sb)
1698{
1699	int space =
1700		imin((int)(sb->sb_hiwat - sb->sb_cc),
1701	    	(int)(sb->sb_mbmax - sb->sb_mbcnt));
1702	if (space < 0)
1703		space = 0;
1704
1705	return space;
1706}
1707
1708/* do we have to send all at once on a socket? */
1709int
1710sosendallatonce(struct socket *so)
1711{
1712	return (so->so_proto->pr_flags & PR_ATOMIC);
1713}
1714
1715/* can we read something from so? */
1716int
1717soreadable(struct socket *so)
1718{
1719	return (so->so_rcv.sb_cc >= so->so_rcv.sb_lowat ||
1720	    (so->so_state & SS_CANTRCVMORE) ||
1721	    so->so_comp.tqh_first || so->so_error);
1722}
1723
1724/* can we write something to so? */
1725
1726int
1727sowriteable(struct socket *so)
1728{
1729	return ((!so_wait_for_if_feedback(so) &&
1730	    sbspace(&(so)->so_snd) >= (so)->so_snd.sb_lowat &&
1731	    ((so->so_state & SS_ISCONNECTED) ||
1732	    (so->so_proto->pr_flags & PR_CONNREQUIRED) == 0)) ||
1733	    (so->so_state & SS_CANTSENDMORE) ||
1734	    so->so_error);
1735}
1736
1737/* adjust counters in sb reflecting allocation of m */
1738
1739void
1740sballoc(struct sockbuf *sb, struct mbuf *m)
1741{
1742	u_int32_t cnt = 1;
1743	sb->sb_cc += m->m_len;
1744	if (m->m_type != MT_DATA && m->m_type != MT_HEADER &&
1745		m->m_type != MT_OOBDATA)
1746		sb->sb_ctl += m->m_len;
1747	sb->sb_mbcnt += MSIZE;
1748
1749	if (m->m_flags & M_EXT) {
1750		sb->sb_mbcnt += m->m_ext.ext_size;
1751		cnt += (m->m_ext.ext_size >> MSIZESHIFT) ;
1752	}
1753	OSAddAtomic(cnt, &total_sbmb_cnt);
1754	VERIFY(total_sbmb_cnt > 0);
1755}
1756
1757/* adjust counters in sb reflecting freeing of m */
1758void
1759sbfree(struct sockbuf *sb, struct mbuf *m)
1760{
1761	int cnt = -1;
1762
1763	sb->sb_cc -= m->m_len;
1764	if (m->m_type != MT_DATA && m->m_type != MT_HEADER &&
1765		m->m_type != MT_OOBDATA)
1766		sb->sb_ctl -= m->m_len;
1767	sb->sb_mbcnt -= MSIZE;
1768	if (m->m_flags & M_EXT) {
1769		sb->sb_mbcnt -= m->m_ext.ext_size;
1770		cnt -= (m->m_ext.ext_size >> MSIZESHIFT) ;
1771	}
1772	OSAddAtomic(cnt, &total_sbmb_cnt);
1773	VERIFY(total_sbmb_cnt >= 0);
1774}
1775
1776/*
1777 * Set lock on sockbuf sb; sleep if lock is already held.
1778 * Unless SB_NOINTR is set on sockbuf, sleep is interruptible.
1779 * Returns error without lock if sleep is interrupted.
1780 *
1781 * Returns:	0			Success
1782 *		EWOULDBLOCK
1783 *	sb_lock:EINTR
1784 */
1785int
1786sblock(struct sockbuf *sb, int wf)
1787{
1788	int error = 0;
1789
1790	if (sb->sb_flags & SB_LOCK)
1791		error = (wf == M_WAIT) ? sb_lock(sb) : EWOULDBLOCK;
1792	else
1793		sb->sb_flags |= SB_LOCK;
1794
1795	return (error);
1796}
1797
1798/* release lock on sockbuf sb */
1799void
1800sbunlock(struct sockbuf *sb, int keeplocked)
1801{
1802	struct socket *so = sb->sb_so;
1803	void *lr_saved;
1804	lck_mtx_t *mutex_held;
1805
1806	lr_saved = __builtin_return_address(0);
1807
1808	sb->sb_flags &= ~SB_LOCK;
1809
1810	if (sb->sb_flags & SB_WANT) {
1811		sb->sb_flags &= ~SB_WANT;
1812		if (so->so_usecount < 0) {
1813			panic("sbunlock: b4 wakeup so=%p ref=%d lr=%p "
1814			    "sb_flags=%x lrh= %s\n", sb->sb_so, so->so_usecount,
1815			    lr_saved, sb->sb_flags, solockhistory_nr(so));
1816			/* NOTREACHED */
1817		}
1818		wakeup((caddr_t)&(sb)->sb_flags);
1819	}
1820	if (keeplocked == 0) {	/* unlock on exit */
1821		if (so->so_proto->pr_getlock != NULL)
1822			mutex_held = (*so->so_proto->pr_getlock)(so, 0);
1823		else
1824			mutex_held = so->so_proto->pr_domain->dom_mtx;
1825
1826		lck_mtx_assert(mutex_held, LCK_MTX_ASSERT_OWNED);
1827
1828		so->so_usecount--;
1829		if (so->so_usecount < 0)
1830			panic("sbunlock: unlock on exit so=%p ref=%d lr=%p "
1831			    "sb_flags=%x lrh= %s\n", so, so->so_usecount, lr_saved,
1832			    sb->sb_flags, solockhistory_nr(so));
1833		so->unlock_lr[so->next_unlock_lr] = lr_saved;
1834		so->next_unlock_lr = (so->next_unlock_lr+1) % SO_LCKDBG_MAX;
1835		lck_mtx_unlock(mutex_held);
1836	}
1837}
1838
1839void
1840sorwakeup(struct socket *so)
1841{
1842	if (sb_notify(&so->so_rcv))
1843		sowakeup(so, &so->so_rcv);
1844}
1845
1846void
1847sowwakeup(struct socket *so)
1848{
1849	if (sb_notify(&so->so_snd))
1850		sowakeup(so, &so->so_snd);
1851}
1852
1853void
1854soevent(struct socket *so, long hint)
1855{
1856	if (so->so_flags & SOF_KNOTE)
1857		KNOTE(&so->so_klist, hint);
1858}
1859
1860#endif /* __APPLE__ */
1861
1862/*
1863 * Make a copy of a sockaddr in a malloced buffer of type M_SONAME.
1864 */
1865struct sockaddr *
1866dup_sockaddr(struct sockaddr *sa, int canwait)
1867{
1868	struct sockaddr *sa2;
1869
1870	MALLOC(sa2, struct sockaddr *, sa->sa_len, M_SONAME,
1871	    canwait ? M_WAITOK : M_NOWAIT);
1872	if (sa2)
1873		bcopy(sa, sa2, sa->sa_len);
1874	return (sa2);
1875}
1876
1877/*
1878 * Create an external-format (``xsocket'') structure using the information
1879 * in the kernel-format socket structure pointed to by so.  This is done
1880 * to reduce the spew of irrelevant information over this interface,
1881 * to isolate user code from changes in the kernel structure, and
1882 * potentially to provide information-hiding if we decide that
1883 * some of this information should be hidden from users.
1884 */
1885void
1886sotoxsocket(struct socket *so, struct xsocket *xso)
1887{
1888	xso->xso_len = sizeof (*xso);
1889	xso->xso_so = (_XSOCKET_PTR(struct socket *))VM_KERNEL_ADDRPERM(so);
1890	xso->so_type = so->so_type;
1891	xso->so_options = (short)(so->so_options & 0xffff);
1892	xso->so_linger = so->so_linger;
1893	xso->so_state = so->so_state;
1894	xso->so_pcb = (_XSOCKET_PTR(caddr_t))VM_KERNEL_ADDRPERM(so->so_pcb);
1895	if (so->so_proto) {
1896		xso->xso_protocol = so->so_proto->pr_protocol;
1897		xso->xso_family = so->so_proto->pr_domain->dom_family;
1898	} else {
1899		xso->xso_protocol = xso->xso_family = 0;
1900	}
1901	xso->so_qlen = so->so_qlen;
1902	xso->so_incqlen = so->so_incqlen;
1903	xso->so_qlimit = so->so_qlimit;
1904	xso->so_timeo = so->so_timeo;
1905	xso->so_error = so->so_error;
1906	xso->so_pgid = so->so_pgid;
1907	xso->so_oobmark = so->so_oobmark;
1908	sbtoxsockbuf(&so->so_snd, &xso->so_snd);
1909	sbtoxsockbuf(&so->so_rcv, &xso->so_rcv);
1910	xso->so_uid = kauth_cred_getuid(so->so_cred);
1911}
1912
1913
1914#if !CONFIG_EMBEDDED
1915
1916void
1917sotoxsocket64(struct socket *so, struct xsocket64 *xso)
1918{
1919        xso->xso_len = sizeof (*xso);
1920        xso->xso_so = (u_int64_t)VM_KERNEL_ADDRPERM(so);
1921        xso->so_type = so->so_type;
1922        xso->so_options = (short)(so->so_options & 0xffff);
1923        xso->so_linger = so->so_linger;
1924        xso->so_state = so->so_state;
1925        xso->so_pcb = (u_int64_t)VM_KERNEL_ADDRPERM(so->so_pcb);
1926        if (so->so_proto) {
1927                xso->xso_protocol = so->so_proto->pr_protocol;
1928                xso->xso_family = so->so_proto->pr_domain->dom_family;
1929        } else {
1930                xso->xso_protocol = xso->xso_family = 0;
1931        }
1932        xso->so_qlen = so->so_qlen;
1933        xso->so_incqlen = so->so_incqlen;
1934        xso->so_qlimit = so->so_qlimit;
1935        xso->so_timeo = so->so_timeo;
1936        xso->so_error = so->so_error;
1937        xso->so_pgid = so->so_pgid;
1938        xso->so_oobmark = so->so_oobmark;
1939        sbtoxsockbuf(&so->so_snd, &xso->so_snd);
1940        sbtoxsockbuf(&so->so_rcv, &xso->so_rcv);
1941        xso->so_uid = kauth_cred_getuid(so->so_cred);
1942}
1943
1944#endif /* !CONFIG_EMBEDDED */
1945
1946/*
1947 * This does the same for sockbufs.  Note that the xsockbuf structure,
1948 * since it is always embedded in a socket, does not include a self
1949 * pointer nor a length.  We make this entry point public in case
1950 * some other mechanism needs it.
1951 */
1952void
1953sbtoxsockbuf(struct sockbuf *sb, struct xsockbuf *xsb)
1954{
1955	xsb->sb_cc = sb->sb_cc;
1956	xsb->sb_hiwat = sb->sb_hiwat;
1957	xsb->sb_mbcnt = sb->sb_mbcnt;
1958	xsb->sb_mbmax = sb->sb_mbmax;
1959	xsb->sb_lowat = sb->sb_lowat;
1960	xsb->sb_flags = sb->sb_flags;
1961	xsb->sb_timeo = (short)
1962	    (sb->sb_timeo.tv_sec * hz) + sb->sb_timeo.tv_usec / tick;
1963	if (xsb->sb_timeo == 0 && sb->sb_timeo.tv_usec != 0)
1964		xsb->sb_timeo = 1;
1965}
1966
1967/*
1968 * Based on the policy set by an all knowing decison maker, throttle sockets
1969 * that either have been marked as belonging to "background" process.
1970 */
1971int
1972soisthrottled(struct socket *so)
1973{
1974	/*
1975	 * On non-embedded, we rely on implicit throttling by the application,
1976	 * as we're missing the system-wide "decision maker".
1977	 */
1978	return (
1979#if CONFIG_EMBEDDED
1980	    net_io_policy_throttled &&
1981#endif /* CONFIG_EMBEDDED */
1982	    (so->so_traffic_mgt_flags & TRAFFIC_MGT_SO_BACKGROUND));
1983}
1984
1985int
1986soisprivilegedtraffic(struct socket *so)
1987{
1988	return (so->so_flags & SOF_PRIVILEGED_TRAFFIC_CLASS);
1989}
1990
1991/*
1992 * Here is the definition of some of the basic objects in the kern.ipc
1993 * branch of the MIB.
1994 */
1995SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW|CTLFLAG_LOCKED|CTLFLAG_ANYBODY, 0, "IPC");
1996
1997/* Check that the maximum socket buffer size is within a range */
1998
1999static int
2000sysctl_sb_max(__unused struct sysctl_oid *oidp, __unused void *arg1,
2001	__unused int arg2, struct sysctl_req *req)
2002{
2003	u_int32_t new_value;
2004	int changed = 0;
2005	int error = sysctl_io_number(req, sb_max, sizeof(u_int32_t), &new_value,
2006		&changed);
2007	if (!error && changed) {
2008		if (new_value > LOW_SB_MAX &&
2009			new_value <= high_sb_max ) {
2010			sb_max = new_value;
2011		} else {
2012			error = ERANGE;
2013		}
2014	}
2015	return error;
2016}
2017
2018static int
2019sysctl_io_policy_throttled SYSCTL_HANDLER_ARGS
2020{
2021#pragma unused(arg1, arg2)
2022	int i, err;
2023
2024	i = net_io_policy_throttled;
2025
2026	err = sysctl_handle_int(oidp, &i, 0, req);
2027	if (err != 0 || req->newptr == USER_ADDR_NULL)
2028		return (err);
2029
2030	if (i != net_io_policy_throttled)
2031		SOTHROTTLELOG(("throttle: network IO policy throttling is "
2032		    "now %s\n", i ? "ON" : "OFF"));
2033
2034	net_io_policy_throttled = i;
2035
2036	return (err);
2037}
2038
2039SYSCTL_PROC(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
2040    &sb_max, 0, &sysctl_sb_max, "IU", "Maximum socket buffer size");
2041
2042SYSCTL_INT(_kern_ipc, OID_AUTO, maxsockets, CTLFLAG_RD | CTLFLAG_LOCKED,
2043    &maxsockets, 0, "Maximum number of sockets avaliable");
2044SYSCTL_INT(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW | CTLFLAG_LOCKED,
2045    &sb_efficiency, 0, "");
2046SYSCTL_INT(_kern_ipc, KIPC_NMBCLUSTERS, nmbclusters, CTLFLAG_RD | CTLFLAG_LOCKED,
2047    &nmbclusters, 0, "");
2048SYSCTL_INT(_kern_ipc, OID_AUTO, njcl, CTLFLAG_RD | CTLFLAG_LOCKED, &njcl, 0, "");
2049SYSCTL_INT(_kern_ipc, OID_AUTO, njclbytes, CTLFLAG_RD | CTLFLAG_LOCKED, &njclbytes, 0, "");
2050SYSCTL_INT(_kern_ipc, KIPC_SOQLIMITCOMPAT, soqlimitcompat, CTLFLAG_RW | CTLFLAG_LOCKED,
2051    &soqlimitcompat, 1, "Enable socket queue limit compatibility");
2052SYSCTL_INT(_kern_ipc, OID_AUTO, soqlencomp, CTLFLAG_RW | CTLFLAG_LOCKED,
2053    &soqlencomp, 0, "Listen backlog represents only complete queue");
2054
2055SYSCTL_NODE(_kern_ipc, OID_AUTO, io_policy, CTLFLAG_RW, 0, "network IO policy");
2056
2057SYSCTL_PROC(_kern_ipc_io_policy, OID_AUTO, throttled,
2058    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &net_io_policy_throttled, 0,
2059    sysctl_io_policy_throttled, "I", "");
2060