xref: /freebsd/sys/kern/uipc_socket.c (revision 63d1fd5970ec814904aa0f4580b10a0d302d08b2)
1 /*-
2  * Copyright (c) 1982, 1986, 1988, 1990, 1993
3  *	The Regents of the University of California.
4  * Copyright (c) 2004 The FreeBSD Foundation
5  * Copyright (c) 2004-2008 Robert N. M. Watson
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)uipc_socket.c	8.3 (Berkeley) 4/15/94
33  */
34 
35 /*
36  * Comments on the socket life cycle:
37  *
38  * soalloc() sets of socket layer state for a socket, called only by
39  * socreate() and sonewconn().  Socket layer private.
40  *
41  * sodealloc() tears down socket layer state for a socket, called only by
42  * sofree() and sonewconn().  Socket layer private.
43  *
44  * pru_attach() associates protocol layer state with an allocated socket;
45  * called only once, may fail, aborting socket allocation.  This is called
46  * from socreate() and sonewconn().  Socket layer private.
47  *
48  * pru_detach() disassociates protocol layer state from an attached socket,
49  * and will be called exactly once for sockets in which pru_attach() has
50  * been successfully called.  If pru_attach() returned an error,
51  * pru_detach() will not be called.  Socket layer private.
52  *
53  * pru_abort() and pru_close() notify the protocol layer that the last
54  * consumer of a socket is starting to tear down the socket, and that the
55  * protocol should terminate the connection.  Historically, pru_abort() also
56  * detached protocol state from the socket state, but this is no longer the
57  * case.
58  *
59  * socreate() creates a socket and attaches protocol state.  This is a public
60  * interface that may be used by socket layer consumers to create new
61  * sockets.
62  *
63  * sonewconn() creates a socket and attaches protocol state.  This is a
64  * public interface  that may be used by protocols to create new sockets when
65  * a new connection is received and will be available for accept() on a
66  * listen socket.
67  *
68  * soclose() destroys a socket after possibly waiting for it to disconnect.
69  * This is a public interface that socket consumers should use to close and
70  * release a socket when done with it.
71  *
72  * soabort() destroys a socket without waiting for it to disconnect (used
73  * only for incoming connections that are already partially or fully
74  * connected).  This is used internally by the socket layer when clearing
75  * listen socket queues (due to overflow or close on the listen socket), but
76  * is also a public interface protocols may use to abort connections in
77  * their incomplete listen queues should they no longer be required.  Sockets
78  * placed in completed connection listen queues should not be aborted for
79  * reasons described in the comment above the soclose() implementation.  This
80  * is not a general purpose close routine, and except in the specific
81  * circumstances described here, should not be used.
82  *
83  * sofree() will free a socket and its protocol state if all references on
84  * the socket have been released, and is the public interface to attempt to
85  * free a socket when a reference is removed.  This is a socket layer private
86  * interface.
87  *
88  * NOTE: In addition to socreate() and soclose(), which provide a single
89  * socket reference to the consumer to be managed as required, there are two
90  * calls to explicitly manage socket references, soref(), and sorele().
91  * Currently, these are generally required only when transitioning a socket
92  * from a listen queue to a file descriptor, in order to prevent garbage
93  * collection of the socket at an untimely moment.  For a number of reasons,
94  * these interfaces are not preferred, and should be avoided.
95  *
96  * NOTE: With regard to VNETs the general rule is that callers do not set
97  * curvnet. Exceptions to this rule include soabort(), sodisconnect(),
98  * sofree() (and with that sorele(), sotryfree()), as well as sonewconn()
99  * and sorflush(), which are usually called from a pre-set VNET context.
100  * sopoll() currently does not need a VNET context to be set.
101  */
102 
103 #include <sys/cdefs.h>
104 __FBSDID("$FreeBSD$");
105 
106 #include "opt_inet.h"
107 #include "opt_inet6.h"
108 #include "opt_compat.h"
109 
110 #include <sys/param.h>
111 #include <sys/systm.h>
112 #include <sys/fcntl.h>
113 #include <sys/limits.h>
114 #include <sys/lock.h>
115 #include <sys/mac.h>
116 #include <sys/malloc.h>
117 #include <sys/mbuf.h>
118 #include <sys/mutex.h>
119 #include <sys/domain.h>
120 #include <sys/file.h>			/* for struct knote */
121 #include <sys/hhook.h>
122 #include <sys/kernel.h>
123 #include <sys/khelp.h>
124 #include <sys/event.h>
125 #include <sys/eventhandler.h>
126 #include <sys/poll.h>
127 #include <sys/proc.h>
128 #include <sys/protosw.h>
129 #include <sys/socket.h>
130 #include <sys/socketvar.h>
131 #include <sys/resourcevar.h>
132 #include <net/route.h>
133 #include <sys/signalvar.h>
134 #include <sys/stat.h>
135 #include <sys/sx.h>
136 #include <sys/sysctl.h>
137 #include <sys/taskqueue.h>
138 #include <sys/uio.h>
139 #include <sys/jail.h>
140 #include <sys/syslog.h>
141 #include <netinet/in.h>
142 
143 #include <net/vnet.h>
144 
145 #include <security/mac/mac_framework.h>
146 
147 #include <vm/uma.h>
148 
149 #ifdef COMPAT_FREEBSD32
150 #include <sys/mount.h>
151 #include <sys/sysent.h>
152 #include <compat/freebsd32/freebsd32.h>
153 #endif
154 
155 static int	soreceive_rcvoob(struct socket *so, struct uio *uio,
156 		    int flags);
157 
158 static void	filt_sordetach(struct knote *kn);
159 static int	filt_soread(struct knote *kn, long hint);
160 static void	filt_sowdetach(struct knote *kn);
161 static int	filt_sowrite(struct knote *kn, long hint);
162 static int	filt_solisten(struct knote *kn, long hint);
163 static int inline hhook_run_socket(struct socket *so, void *hctx, int32_t h_id);
164 fo_kqfilter_t	soo_kqfilter;
165 
166 static struct filterops solisten_filtops = {
167 	.f_isfd = 1,
168 	.f_detach = filt_sordetach,
169 	.f_event = filt_solisten,
170 };
171 static struct filterops soread_filtops = {
172 	.f_isfd = 1,
173 	.f_detach = filt_sordetach,
174 	.f_event = filt_soread,
175 };
176 static struct filterops sowrite_filtops = {
177 	.f_isfd = 1,
178 	.f_detach = filt_sowdetach,
179 	.f_event = filt_sowrite,
180 };
181 
182 so_gen_t	so_gencnt;	/* generation count for sockets */
183 
184 MALLOC_DEFINE(M_SONAME, "soname", "socket name");
185 MALLOC_DEFINE(M_PCB, "pcb", "protocol control block");
186 
187 #define	VNET_SO_ASSERT(so)						\
188 	VNET_ASSERT(curvnet != NULL,					\
189 	    ("%s:%d curvnet is NULL, so=%p", __func__, __LINE__, (so)));
190 
191 VNET_DEFINE(struct hhook_head *, socket_hhh[HHOOK_SOCKET_LAST + 1]);
192 #define	V_socket_hhh		VNET(socket_hhh)
193 
194 /*
195  * Limit on the number of connections in the listen queue waiting
196  * for accept(2).
197  * NB: The original sysctl somaxconn is still available but hidden
198  * to prevent confusion about the actual purpose of this number.
199  */
200 static u_int somaxconn = SOMAXCONN;
201 
202 static int
203 sysctl_somaxconn(SYSCTL_HANDLER_ARGS)
204 {
205 	int error;
206 	int val;
207 
208 	val = somaxconn;
209 	error = sysctl_handle_int(oidp, &val, 0, req);
210 	if (error || !req->newptr )
211 		return (error);
212 
213 	/*
214 	 * The purpose of the UINT_MAX / 3 limit, is so that the formula
215 	 *   3 * so_qlimit / 2
216 	 * below, will not overflow.
217          */
218 
219 	if (val < 1 || val > UINT_MAX / 3)
220 		return (EINVAL);
221 
222 	somaxconn = val;
223 	return (0);
224 }
225 SYSCTL_PROC(_kern_ipc, OID_AUTO, soacceptqueue, CTLTYPE_UINT | CTLFLAG_RW,
226     0, sizeof(int), sysctl_somaxconn, "I",
227     "Maximum listen socket pending connection accept queue size");
228 SYSCTL_PROC(_kern_ipc, KIPC_SOMAXCONN, somaxconn,
229     CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_SKIP,
230     0, sizeof(int), sysctl_somaxconn, "I",
231     "Maximum listen socket pending connection accept queue size (compat)");
232 
233 static int numopensockets;
234 SYSCTL_INT(_kern_ipc, OID_AUTO, numopensockets, CTLFLAG_RD,
235     &numopensockets, 0, "Number of open sockets");
236 
237 /*
238  * accept_mtx locks down per-socket fields relating to accept queues.  See
239  * socketvar.h for an annotation of the protected fields of struct socket.
240  */
241 struct mtx accept_mtx;
242 MTX_SYSINIT(accept_mtx, &accept_mtx, "accept", MTX_DEF);
243 
244 /*
245  * so_global_mtx protects so_gencnt, numopensockets, and the per-socket
246  * so_gencnt field.
247  */
248 static struct mtx so_global_mtx;
249 MTX_SYSINIT(so_global_mtx, &so_global_mtx, "so_glabel", MTX_DEF);
250 
251 /*
252  * General IPC sysctl name space, used by sockets and a variety of other IPC
253  * types.
254  */
255 SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW, 0, "IPC");
256 
257 /*
258  * Initialize the socket subsystem and set up the socket
259  * memory allocator.
260  */
261 static uma_zone_t socket_zone;
262 int	maxsockets;
263 
264 static void
265 socket_zone_change(void *tag)
266 {
267 
268 	maxsockets = uma_zone_set_max(socket_zone, maxsockets);
269 }
270 
271 static void
272 socket_hhook_register(int subtype)
273 {
274 
275 	if (hhook_head_register(HHOOK_TYPE_SOCKET, subtype,
276 	    &V_socket_hhh[subtype],
277 	    HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
278 		printf("%s: WARNING: unable to register hook\n", __func__);
279 }
280 
281 static void
282 socket_hhook_deregister(int subtype)
283 {
284 
285 	if (hhook_head_deregister(V_socket_hhh[subtype]) != 0)
286 		printf("%s: WARNING: unable to deregister hook\n", __func__);
287 }
288 
289 static void
290 socket_init(void *tag)
291 {
292 
293 	socket_zone = uma_zcreate("socket", sizeof(struct socket), NULL, NULL,
294 	    NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
295 	maxsockets = uma_zone_set_max(socket_zone, maxsockets);
296 	uma_zone_set_warning(socket_zone, "kern.ipc.maxsockets limit reached");
297 	EVENTHANDLER_REGISTER(maxsockets_change, socket_zone_change, NULL,
298 	    EVENTHANDLER_PRI_FIRST);
299 }
300 SYSINIT(socket, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY, socket_init, NULL);
301 
302 static void
303 socket_vnet_init(const void *unused __unused)
304 {
305 	int i;
306 
307 	/* We expect a contiguous range */
308 	for (i = 0; i <= HHOOK_SOCKET_LAST; i++)
309 		socket_hhook_register(i);
310 }
311 VNET_SYSINIT(socket_vnet_init, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY,
312     socket_vnet_init, NULL);
313 
314 static void
315 socket_vnet_uninit(const void *unused __unused)
316 {
317 	int i;
318 
319 	for (i = 0; i <= HHOOK_SOCKET_LAST; i++)
320 		socket_hhook_deregister(i);
321 }
322 VNET_SYSUNINIT(socket_vnet_uninit, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY,
323     socket_vnet_uninit, NULL);
324 
325 /*
326  * Initialise maxsockets.  This SYSINIT must be run after
327  * tunable_mbinit().
328  */
329 static void
330 init_maxsockets(void *ignored)
331 {
332 
333 	TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets);
334 	maxsockets = imax(maxsockets, maxfiles);
335 }
336 SYSINIT(param, SI_SUB_TUNABLES, SI_ORDER_ANY, init_maxsockets, NULL);
337 
338 /*
339  * Sysctl to get and set the maximum global sockets limit.  Notify protocols
340  * of the change so that they can update their dependent limits as required.
341  */
342 static int
343 sysctl_maxsockets(SYSCTL_HANDLER_ARGS)
344 {
345 	int error, newmaxsockets;
346 
347 	newmaxsockets = maxsockets;
348 	error = sysctl_handle_int(oidp, &newmaxsockets, 0, req);
349 	if (error == 0 && req->newptr) {
350 		if (newmaxsockets > maxsockets &&
351 		    newmaxsockets <= maxfiles) {
352 			maxsockets = newmaxsockets;
353 			EVENTHANDLER_INVOKE(maxsockets_change);
354 		} else
355 			error = EINVAL;
356 	}
357 	return (error);
358 }
359 SYSCTL_PROC(_kern_ipc, OID_AUTO, maxsockets, CTLTYPE_INT|CTLFLAG_RW,
360     &maxsockets, 0, sysctl_maxsockets, "IU",
361     "Maximum number of sockets available");
362 
363 /*
364  * Socket operation routines.  These routines are called by the routines in
365  * sys_socket.c or from a system process, and implement the semantics of
366  * socket operations by switching out to the protocol specific routines.
367  */
368 
369 /*
370  * Get a socket structure from our zone, and initialize it.  Note that it
371  * would probably be better to allocate socket and PCB at the same time, but
372  * I'm not convinced that all the protocols can be easily modified to do
373  * this.
374  *
375  * soalloc() returns a socket with a ref count of 0.
376  */
377 static struct socket *
378 soalloc(struct vnet *vnet)
379 {
380 	struct socket *so;
381 
382 	so = uma_zalloc(socket_zone, M_NOWAIT | M_ZERO);
383 	if (so == NULL)
384 		return (NULL);
385 #ifdef MAC
386 	if (mac_socket_init(so, M_NOWAIT) != 0) {
387 		uma_zfree(socket_zone, so);
388 		return (NULL);
389 	}
390 #endif
391 	if (khelp_init_osd(HELPER_CLASS_SOCKET, &so->osd)) {
392 		uma_zfree(socket_zone, so);
393 		return (NULL);
394 	}
395 
396 	SOCKBUF_LOCK_INIT(&so->so_snd, "so_snd");
397 	SOCKBUF_LOCK_INIT(&so->so_rcv, "so_rcv");
398 	sx_init(&so->so_snd.sb_sx, "so_snd_sx");
399 	sx_init(&so->so_rcv.sb_sx, "so_rcv_sx");
400 	TAILQ_INIT(&so->so_snd.sb_aiojobq);
401 	TAILQ_INIT(&so->so_rcv.sb_aiojobq);
402 	TASK_INIT(&so->so_snd.sb_aiotask, 0, soaio_snd, so);
403 	TASK_INIT(&so->so_rcv.sb_aiotask, 0, soaio_rcv, so);
404 #ifdef VIMAGE
405 	VNET_ASSERT(vnet != NULL, ("%s:%d vnet is NULL, so=%p",
406 	    __func__, __LINE__, so));
407 	so->so_vnet = vnet;
408 #endif
409 	/* We shouldn't need the so_global_mtx */
410 	if (hhook_run_socket(so, NULL, HHOOK_SOCKET_CREATE)) {
411 		/* Do we need more comprehensive error returns? */
412 		uma_zfree(socket_zone, so);
413 		return (NULL);
414 	}
415 	mtx_lock(&so_global_mtx);
416 	so->so_gencnt = ++so_gencnt;
417 	++numopensockets;
418 #ifdef VIMAGE
419 	vnet->vnet_sockcnt++;
420 #endif
421 	mtx_unlock(&so_global_mtx);
422 
423 	return (so);
424 }
425 
426 /*
427  * Free the storage associated with a socket at the socket layer, tear down
428  * locks, labels, etc.  All protocol state is assumed already to have been
429  * torn down (and possibly never set up) by the caller.
430  */
431 static void
432 sodealloc(struct socket *so)
433 {
434 
435 	KASSERT(so->so_count == 0, ("sodealloc(): so_count %d", so->so_count));
436 	KASSERT(so->so_pcb == NULL, ("sodealloc(): so_pcb != NULL"));
437 
438 	mtx_lock(&so_global_mtx);
439 	so->so_gencnt = ++so_gencnt;
440 	--numopensockets;	/* Could be below, but faster here. */
441 #ifdef VIMAGE
442 	VNET_ASSERT(so->so_vnet != NULL, ("%s:%d so_vnet is NULL, so=%p",
443 	    __func__, __LINE__, so));
444 	so->so_vnet->vnet_sockcnt--;
445 #endif
446 	mtx_unlock(&so_global_mtx);
447 	if (so->so_rcv.sb_hiwat)
448 		(void)chgsbsize(so->so_cred->cr_uidinfo,
449 		    &so->so_rcv.sb_hiwat, 0, RLIM_INFINITY);
450 	if (so->so_snd.sb_hiwat)
451 		(void)chgsbsize(so->so_cred->cr_uidinfo,
452 		    &so->so_snd.sb_hiwat, 0, RLIM_INFINITY);
453 	/* remove accept filter if one is present. */
454 	if (so->so_accf != NULL)
455 		do_setopt_accept_filter(so, NULL);
456 #ifdef MAC
457 	mac_socket_destroy(so);
458 #endif
459 	hhook_run_socket(so, NULL, HHOOK_SOCKET_CLOSE);
460 
461 	crfree(so->so_cred);
462 	khelp_destroy_osd(&so->osd);
463 	sx_destroy(&so->so_snd.sb_sx);
464 	sx_destroy(&so->so_rcv.sb_sx);
465 	SOCKBUF_LOCK_DESTROY(&so->so_snd);
466 	SOCKBUF_LOCK_DESTROY(&so->so_rcv);
467 	uma_zfree(socket_zone, so);
468 }
469 
470 /*
471  * socreate returns a socket with a ref count of 1.  The socket should be
472  * closed with soclose().
473  */
474 int
475 socreate(int dom, struct socket **aso, int type, int proto,
476     struct ucred *cred, struct thread *td)
477 {
478 	struct protosw *prp;
479 	struct socket *so;
480 	int error;
481 
482 	if (proto)
483 		prp = pffindproto(dom, proto, type);
484 	else
485 		prp = pffindtype(dom, type);
486 
487 	if (prp == NULL) {
488 		/* No support for domain. */
489 		if (pffinddomain(dom) == NULL)
490 			return (EAFNOSUPPORT);
491 		/* No support for socket type. */
492 		if (proto == 0 && type != 0)
493 			return (EPROTOTYPE);
494 		return (EPROTONOSUPPORT);
495 	}
496 	if (prp->pr_usrreqs->pru_attach == NULL ||
497 	    prp->pr_usrreqs->pru_attach == pru_attach_notsupp)
498 		return (EPROTONOSUPPORT);
499 
500 	if (prison_check_af(cred, prp->pr_domain->dom_family) != 0)
501 		return (EPROTONOSUPPORT);
502 
503 	if (prp->pr_type != type)
504 		return (EPROTOTYPE);
505 	so = soalloc(CRED_TO_VNET(cred));
506 	if (so == NULL)
507 		return (ENOBUFS);
508 
509 	TAILQ_INIT(&so->so_incomp);
510 	TAILQ_INIT(&so->so_comp);
511 	so->so_type = type;
512 	so->so_cred = crhold(cred);
513 	if ((prp->pr_domain->dom_family == PF_INET) ||
514 	    (prp->pr_domain->dom_family == PF_INET6) ||
515 	    (prp->pr_domain->dom_family == PF_ROUTE))
516 		so->so_fibnum = td->td_proc->p_fibnum;
517 	else
518 		so->so_fibnum = 0;
519 	so->so_proto = prp;
520 #ifdef MAC
521 	mac_socket_create(cred, so);
522 #endif
523 	knlist_init_mtx(&so->so_rcv.sb_sel.si_note, SOCKBUF_MTX(&so->so_rcv));
524 	knlist_init_mtx(&so->so_snd.sb_sel.si_note, SOCKBUF_MTX(&so->so_snd));
525 	so->so_count = 1;
526 	/*
527 	 * Auto-sizing of socket buffers is managed by the protocols and
528 	 * the appropriate flags must be set in the pru_attach function.
529 	 */
530 	CURVNET_SET(so->so_vnet);
531 	error = (*prp->pr_usrreqs->pru_attach)(so, proto, td);
532 	CURVNET_RESTORE();
533 	if (error) {
534 		KASSERT(so->so_count == 1, ("socreate: so_count %d",
535 		    so->so_count));
536 		so->so_count = 0;
537 		sodealloc(so);
538 		return (error);
539 	}
540 	*aso = so;
541 	return (0);
542 }
543 
544 #ifdef REGRESSION
545 static int regression_sonewconn_earlytest = 1;
546 SYSCTL_INT(_regression, OID_AUTO, sonewconn_earlytest, CTLFLAG_RW,
547     &regression_sonewconn_earlytest, 0, "Perform early sonewconn limit test");
548 #endif
549 
550 /*
551  * When an attempt at a new connection is noted on a socket which accepts
552  * connections, sonewconn is called.  If the connection is possible (subject
553  * to space constraints, etc.) then we allocate a new structure, properly
554  * linked into the data structure of the original socket, and return this.
555  * Connstatus may be 0, or SS_ISCONFIRMING, or SS_ISCONNECTED.
556  *
557  * Note: the ref count on the socket is 0 on return.
558  */
559 struct socket *
560 sonewconn(struct socket *head, int connstatus)
561 {
562 	static struct timeval lastover;
563 	static struct timeval overinterval = { 60, 0 };
564 	static int overcount;
565 
566 	struct socket *so;
567 	int over;
568 
569 	ACCEPT_LOCK();
570 	over = (head->so_qlen > 3 * head->so_qlimit / 2);
571 	ACCEPT_UNLOCK();
572 #ifdef REGRESSION
573 	if (regression_sonewconn_earlytest && over) {
574 #else
575 	if (over) {
576 #endif
577 		overcount++;
578 
579 		if (ratecheck(&lastover, &overinterval)) {
580 			log(LOG_DEBUG, "%s: pcb %p: Listen queue overflow: "
581 			    "%i already in queue awaiting acceptance "
582 			    "(%d occurrences)\n",
583 			    __func__, head->so_pcb, head->so_qlen, overcount);
584 
585 			overcount = 0;
586 		}
587 
588 		return (NULL);
589 	}
590 	VNET_ASSERT(head->so_vnet != NULL, ("%s:%d so_vnet is NULL, head=%p",
591 	    __func__, __LINE__, head));
592 	so = soalloc(head->so_vnet);
593 	if (so == NULL) {
594 		log(LOG_DEBUG, "%s: pcb %p: New socket allocation failure: "
595 		    "limit reached or out of memory\n",
596 		    __func__, head->so_pcb);
597 		return (NULL);
598 	}
599 	if ((head->so_options & SO_ACCEPTFILTER) != 0)
600 		connstatus = 0;
601 	so->so_head = head;
602 	so->so_type = head->so_type;
603 	so->so_options = head->so_options &~ SO_ACCEPTCONN;
604 	so->so_linger = head->so_linger;
605 	so->so_state = head->so_state | SS_NOFDREF;
606 	so->so_fibnum = head->so_fibnum;
607 	so->so_proto = head->so_proto;
608 	so->so_cred = crhold(head->so_cred);
609 #ifdef MAC
610 	mac_socket_newconn(head, so);
611 #endif
612 	knlist_init_mtx(&so->so_rcv.sb_sel.si_note, SOCKBUF_MTX(&so->so_rcv));
613 	knlist_init_mtx(&so->so_snd.sb_sel.si_note, SOCKBUF_MTX(&so->so_snd));
614 	VNET_SO_ASSERT(head);
615 	if (soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat)) {
616 		sodealloc(so);
617 		log(LOG_DEBUG, "%s: pcb %p: soreserve() failed\n",
618 		    __func__, head->so_pcb);
619 		return (NULL);
620 	}
621 	if ((*so->so_proto->pr_usrreqs->pru_attach)(so, 0, NULL)) {
622 		sodealloc(so);
623 		log(LOG_DEBUG, "%s: pcb %p: pru_attach() failed\n",
624 		    __func__, head->so_pcb);
625 		return (NULL);
626 	}
627 	so->so_rcv.sb_lowat = head->so_rcv.sb_lowat;
628 	so->so_snd.sb_lowat = head->so_snd.sb_lowat;
629 	so->so_rcv.sb_timeo = head->so_rcv.sb_timeo;
630 	so->so_snd.sb_timeo = head->so_snd.sb_timeo;
631 	so->so_rcv.sb_flags |= head->so_rcv.sb_flags & SB_AUTOSIZE;
632 	so->so_snd.sb_flags |= head->so_snd.sb_flags & SB_AUTOSIZE;
633 	so->so_state |= connstatus;
634 	ACCEPT_LOCK();
635 	/*
636 	 * The accept socket may be tearing down but we just
637 	 * won a race on the ACCEPT_LOCK.
638 	 * However, if sctp_peeloff() is called on a 1-to-many
639 	 * style socket, the SO_ACCEPTCONN doesn't need to be set.
640 	 */
641 	if (!(head->so_options & SO_ACCEPTCONN) &&
642 	    ((head->so_proto->pr_protocol != IPPROTO_SCTP) ||
643 	     (head->so_type != SOCK_SEQPACKET))) {
644 		SOCK_LOCK(so);
645 		so->so_head = NULL;
646 		sofree(so);		/* NB: returns ACCEPT_UNLOCK'ed. */
647 		return (NULL);
648 	}
649 	if (connstatus) {
650 		TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
651 		so->so_qstate |= SQ_COMP;
652 		head->so_qlen++;
653 	} else {
654 		/*
655 		 * Keep removing sockets from the head until there's room for
656 		 * us to insert on the tail.  In pre-locking revisions, this
657 		 * was a simple if(), but as we could be racing with other
658 		 * threads and soabort() requires dropping locks, we must
659 		 * loop waiting for the condition to be true.
660 		 */
661 		while (head->so_incqlen > head->so_qlimit) {
662 			struct socket *sp;
663 			sp = TAILQ_FIRST(&head->so_incomp);
664 			TAILQ_REMOVE(&head->so_incomp, sp, so_list);
665 			head->so_incqlen--;
666 			sp->so_qstate &= ~SQ_INCOMP;
667 			sp->so_head = NULL;
668 			ACCEPT_UNLOCK();
669 			soabort(sp);
670 			ACCEPT_LOCK();
671 		}
672 		TAILQ_INSERT_TAIL(&head->so_incomp, so, so_list);
673 		so->so_qstate |= SQ_INCOMP;
674 		head->so_incqlen++;
675 	}
676 	ACCEPT_UNLOCK();
677 	if (connstatus) {
678 		sorwakeup(head);
679 		wakeup_one(&head->so_timeo);
680 	}
681 	return (so);
682 }
683 
684 int
685 sobind(struct socket *so, struct sockaddr *nam, struct thread *td)
686 {
687 	int error;
688 
689 	CURVNET_SET(so->so_vnet);
690 	error = (*so->so_proto->pr_usrreqs->pru_bind)(so, nam, td);
691 	CURVNET_RESTORE();
692 	return (error);
693 }
694 
695 int
696 sobindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
697 {
698 	int error;
699 
700 	CURVNET_SET(so->so_vnet);
701 	error = (*so->so_proto->pr_usrreqs->pru_bindat)(fd, so, nam, td);
702 	CURVNET_RESTORE();
703 	return (error);
704 }
705 
706 /*
707  * solisten() transitions a socket from a non-listening state to a listening
708  * state, but can also be used to update the listen queue depth on an
709  * existing listen socket.  The protocol will call back into the sockets
710  * layer using solisten_proto_check() and solisten_proto() to check and set
711  * socket-layer listen state.  Call backs are used so that the protocol can
712  * acquire both protocol and socket layer locks in whatever order is required
713  * by the protocol.
714  *
715  * Protocol implementors are advised to hold the socket lock across the
716  * socket-layer test and set to avoid races at the socket layer.
717  */
718 int
719 solisten(struct socket *so, int backlog, struct thread *td)
720 {
721 	int error;
722 
723 	CURVNET_SET(so->so_vnet);
724 	error = (*so->so_proto->pr_usrreqs->pru_listen)(so, backlog, td);
725 	CURVNET_RESTORE();
726 	return (error);
727 }
728 
729 int
730 solisten_proto_check(struct socket *so)
731 {
732 
733 	SOCK_LOCK_ASSERT(so);
734 
735 	if (so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING |
736 	    SS_ISDISCONNECTING))
737 		return (EINVAL);
738 	return (0);
739 }
740 
741 void
742 solisten_proto(struct socket *so, int backlog)
743 {
744 
745 	SOCK_LOCK_ASSERT(so);
746 
747 	if (backlog < 0 || backlog > somaxconn)
748 		backlog = somaxconn;
749 	so->so_qlimit = backlog;
750 	so->so_options |= SO_ACCEPTCONN;
751 }
752 
753 /*
754  * Evaluate the reference count and named references on a socket; if no
755  * references remain, free it.  This should be called whenever a reference is
756  * released, such as in sorele(), but also when named reference flags are
757  * cleared in socket or protocol code.
758  *
759  * sofree() will free the socket if:
760  *
761  * - There are no outstanding file descriptor references or related consumers
762  *   (so_count == 0).
763  *
764  * - The socket has been closed by user space, if ever open (SS_NOFDREF).
765  *
766  * - The protocol does not have an outstanding strong reference on the socket
767  *   (SS_PROTOREF).
768  *
769  * - The socket is not in a completed connection queue, so a process has been
770  *   notified that it is present.  If it is removed, the user process may
771  *   block in accept() despite select() saying the socket was ready.
772  */
773 void
774 sofree(struct socket *so)
775 {
776 	struct protosw *pr = so->so_proto;
777 	struct socket *head;
778 
779 	ACCEPT_LOCK_ASSERT();
780 	SOCK_LOCK_ASSERT(so);
781 
782 	if ((so->so_state & SS_NOFDREF) == 0 || so->so_count != 0 ||
783 	    (so->so_state & SS_PROTOREF) || (so->so_qstate & SQ_COMP)) {
784 		SOCK_UNLOCK(so);
785 		ACCEPT_UNLOCK();
786 		return;
787 	}
788 
789 	head = so->so_head;
790 	if (head != NULL) {
791 		KASSERT((so->so_qstate & SQ_COMP) != 0 ||
792 		    (so->so_qstate & SQ_INCOMP) != 0,
793 		    ("sofree: so_head != NULL, but neither SQ_COMP nor "
794 		    "SQ_INCOMP"));
795 		KASSERT((so->so_qstate & SQ_COMP) == 0 ||
796 		    (so->so_qstate & SQ_INCOMP) == 0,
797 		    ("sofree: so->so_qstate is SQ_COMP and also SQ_INCOMP"));
798 		TAILQ_REMOVE(&head->so_incomp, so, so_list);
799 		head->so_incqlen--;
800 		so->so_qstate &= ~SQ_INCOMP;
801 		so->so_head = NULL;
802 	}
803 	KASSERT((so->so_qstate & SQ_COMP) == 0 &&
804 	    (so->so_qstate & SQ_INCOMP) == 0,
805 	    ("sofree: so_head == NULL, but still SQ_COMP(%d) or SQ_INCOMP(%d)",
806 	    so->so_qstate & SQ_COMP, so->so_qstate & SQ_INCOMP));
807 	if (so->so_options & SO_ACCEPTCONN) {
808 		KASSERT((TAILQ_EMPTY(&so->so_comp)),
809 		    ("sofree: so_comp populated"));
810 		KASSERT((TAILQ_EMPTY(&so->so_incomp)),
811 		    ("sofree: so_incomp populated"));
812 	}
813 	SOCK_UNLOCK(so);
814 	ACCEPT_UNLOCK();
815 
816 	VNET_SO_ASSERT(so);
817 	if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose != NULL)
818 		(*pr->pr_domain->dom_dispose)(so);
819 	if (pr->pr_usrreqs->pru_detach != NULL)
820 		(*pr->pr_usrreqs->pru_detach)(so);
821 
822 	/*
823 	 * From this point on, we assume that no other references to this
824 	 * socket exist anywhere else in the stack.  Therefore, no locks need
825 	 * to be acquired or held.
826 	 *
827 	 * We used to do a lot of socket buffer and socket locking here, as
828 	 * well as invoke sorflush() and perform wakeups.  The direct call to
829 	 * dom_dispose() and sbrelease_internal() are an inlining of what was
830 	 * necessary from sorflush().
831 	 *
832 	 * Notice that the socket buffer and kqueue state are torn down
833 	 * before calling pru_detach.  This means that protocols shold not
834 	 * assume they can perform socket wakeups, etc, in their detach code.
835 	 */
836 	sbdestroy(&so->so_snd, so);
837 	sbdestroy(&so->so_rcv, so);
838 	seldrain(&so->so_snd.sb_sel);
839 	seldrain(&so->so_rcv.sb_sel);
840 	knlist_destroy(&so->so_rcv.sb_sel.si_note);
841 	knlist_destroy(&so->so_snd.sb_sel.si_note);
842 	sodealloc(so);
843 }
844 
845 /*
846  * Close a socket on last file table reference removal.  Initiate disconnect
847  * if connected.  Free socket when disconnect complete.
848  *
849  * This function will sorele() the socket.  Note that soclose() may be called
850  * prior to the ref count reaching zero.  The actual socket structure will
851  * not be freed until the ref count reaches zero.
852  */
853 int
854 soclose(struct socket *so)
855 {
856 	int error = 0;
857 
858 	KASSERT(!(so->so_state & SS_NOFDREF), ("soclose: SS_NOFDREF on enter"));
859 
860 	CURVNET_SET(so->so_vnet);
861 	funsetown(&so->so_sigio);
862 	if (so->so_state & SS_ISCONNECTED) {
863 		if ((so->so_state & SS_ISDISCONNECTING) == 0) {
864 			error = sodisconnect(so);
865 			if (error) {
866 				if (error == ENOTCONN)
867 					error = 0;
868 				goto drop;
869 			}
870 		}
871 		if (so->so_options & SO_LINGER) {
872 			if ((so->so_state & SS_ISDISCONNECTING) &&
873 			    (so->so_state & SS_NBIO))
874 				goto drop;
875 			while (so->so_state & SS_ISCONNECTED) {
876 				error = tsleep(&so->so_timeo,
877 				    PSOCK | PCATCH, "soclos",
878 				    so->so_linger * hz);
879 				if (error)
880 					break;
881 			}
882 		}
883 	}
884 
885 drop:
886 	if (so->so_proto->pr_usrreqs->pru_close != NULL)
887 		(*so->so_proto->pr_usrreqs->pru_close)(so);
888 	ACCEPT_LOCK();
889 	if (so->so_options & SO_ACCEPTCONN) {
890 		struct socket *sp;
891 		/*
892 		 * Prevent new additions to the accept queues due
893 		 * to ACCEPT_LOCK races while we are draining them.
894 		 */
895 		so->so_options &= ~SO_ACCEPTCONN;
896 		while ((sp = TAILQ_FIRST(&so->so_incomp)) != NULL) {
897 			TAILQ_REMOVE(&so->so_incomp, sp, so_list);
898 			so->so_incqlen--;
899 			sp->so_qstate &= ~SQ_INCOMP;
900 			sp->so_head = NULL;
901 			ACCEPT_UNLOCK();
902 			soabort(sp);
903 			ACCEPT_LOCK();
904 		}
905 		while ((sp = TAILQ_FIRST(&so->so_comp)) != NULL) {
906 			TAILQ_REMOVE(&so->so_comp, sp, so_list);
907 			so->so_qlen--;
908 			sp->so_qstate &= ~SQ_COMP;
909 			sp->so_head = NULL;
910 			ACCEPT_UNLOCK();
911 			soabort(sp);
912 			ACCEPT_LOCK();
913 		}
914 		KASSERT((TAILQ_EMPTY(&so->so_comp)),
915 		    ("%s: so_comp populated", __func__));
916 		KASSERT((TAILQ_EMPTY(&so->so_incomp)),
917 		    ("%s: so_incomp populated", __func__));
918 	}
919 	SOCK_LOCK(so);
920 	KASSERT((so->so_state & SS_NOFDREF) == 0, ("soclose: NOFDREF"));
921 	so->so_state |= SS_NOFDREF;
922 	sorele(so);			/* NB: Returns with ACCEPT_UNLOCK(). */
923 	CURVNET_RESTORE();
924 	return (error);
925 }
926 
927 /*
928  * soabort() is used to abruptly tear down a connection, such as when a
929  * resource limit is reached (listen queue depth exceeded), or if a listen
930  * socket is closed while there are sockets waiting to be accepted.
931  *
932  * This interface is tricky, because it is called on an unreferenced socket,
933  * and must be called only by a thread that has actually removed the socket
934  * from the listen queue it was on, or races with other threads are risked.
935  *
936  * This interface will call into the protocol code, so must not be called
937  * with any socket locks held.  Protocols do call it while holding their own
938  * recursible protocol mutexes, but this is something that should be subject
939  * to review in the future.
940  */
941 void
942 soabort(struct socket *so)
943 {
944 
945 	/*
946 	 * In as much as is possible, assert that no references to this
947 	 * socket are held.  This is not quite the same as asserting that the
948 	 * current thread is responsible for arranging for no references, but
949 	 * is as close as we can get for now.
950 	 */
951 	KASSERT(so->so_count == 0, ("soabort: so_count"));
952 	KASSERT((so->so_state & SS_PROTOREF) == 0, ("soabort: SS_PROTOREF"));
953 	KASSERT(so->so_state & SS_NOFDREF, ("soabort: !SS_NOFDREF"));
954 	KASSERT((so->so_state & SQ_COMP) == 0, ("soabort: SQ_COMP"));
955 	KASSERT((so->so_state & SQ_INCOMP) == 0, ("soabort: SQ_INCOMP"));
956 	VNET_SO_ASSERT(so);
957 
958 	if (so->so_proto->pr_usrreqs->pru_abort != NULL)
959 		(*so->so_proto->pr_usrreqs->pru_abort)(so);
960 	ACCEPT_LOCK();
961 	SOCK_LOCK(so);
962 	sofree(so);
963 }
964 
965 int
966 soaccept(struct socket *so, struct sockaddr **nam)
967 {
968 	int error;
969 
970 	SOCK_LOCK(so);
971 	KASSERT((so->so_state & SS_NOFDREF) != 0, ("soaccept: !NOFDREF"));
972 	so->so_state &= ~SS_NOFDREF;
973 	SOCK_UNLOCK(so);
974 
975 	CURVNET_SET(so->so_vnet);
976 	error = (*so->so_proto->pr_usrreqs->pru_accept)(so, nam);
977 	CURVNET_RESTORE();
978 	return (error);
979 }
980 
981 int
982 soconnect(struct socket *so, struct sockaddr *nam, struct thread *td)
983 {
984 
985 	return (soconnectat(AT_FDCWD, so, nam, td));
986 }
987 
988 int
989 soconnectat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
990 {
991 	int error;
992 
993 	if (so->so_options & SO_ACCEPTCONN)
994 		return (EOPNOTSUPP);
995 
996 	CURVNET_SET(so->so_vnet);
997 	/*
998 	 * If protocol is connection-based, can only connect once.
999 	 * Otherwise, if connected, try to disconnect first.  This allows
1000 	 * user to disconnect by connecting to, e.g., a null address.
1001 	 */
1002 	if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
1003 	    ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
1004 	    (error = sodisconnect(so)))) {
1005 		error = EISCONN;
1006 	} else {
1007 		/*
1008 		 * Prevent accumulated error from previous connection from
1009 		 * biting us.
1010 		 */
1011 		so->so_error = 0;
1012 		if (fd == AT_FDCWD) {
1013 			error = (*so->so_proto->pr_usrreqs->pru_connect)(so,
1014 			    nam, td);
1015 		} else {
1016 			error = (*so->so_proto->pr_usrreqs->pru_connectat)(fd,
1017 			    so, nam, td);
1018 		}
1019 	}
1020 	CURVNET_RESTORE();
1021 
1022 	return (error);
1023 }
1024 
1025 int
1026 soconnect2(struct socket *so1, struct socket *so2)
1027 {
1028 	int error;
1029 
1030 	CURVNET_SET(so1->so_vnet);
1031 	error = (*so1->so_proto->pr_usrreqs->pru_connect2)(so1, so2);
1032 	CURVNET_RESTORE();
1033 	return (error);
1034 }
1035 
1036 int
1037 sodisconnect(struct socket *so)
1038 {
1039 	int error;
1040 
1041 	if ((so->so_state & SS_ISCONNECTED) == 0)
1042 		return (ENOTCONN);
1043 	if (so->so_state & SS_ISDISCONNECTING)
1044 		return (EALREADY);
1045 	VNET_SO_ASSERT(so);
1046 	error = (*so->so_proto->pr_usrreqs->pru_disconnect)(so);
1047 	return (error);
1048 }
1049 
1050 #define	SBLOCKWAIT(f)	(((f) & MSG_DONTWAIT) ? 0 : SBL_WAIT)
1051 
1052 int
1053 sosend_dgram(struct socket *so, struct sockaddr *addr, struct uio *uio,
1054     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
1055 {
1056 	long space;
1057 	ssize_t resid;
1058 	int clen = 0, error, dontroute;
1059 
1060 	KASSERT(so->so_type == SOCK_DGRAM, ("sosend_dgram: !SOCK_DGRAM"));
1061 	KASSERT(so->so_proto->pr_flags & PR_ATOMIC,
1062 	    ("sosend_dgram: !PR_ATOMIC"));
1063 
1064 	if (uio != NULL)
1065 		resid = uio->uio_resid;
1066 	else
1067 		resid = top->m_pkthdr.len;
1068 	/*
1069 	 * In theory resid should be unsigned.  However, space must be
1070 	 * signed, as it might be less than 0 if we over-committed, and we
1071 	 * must use a signed comparison of space and resid.  On the other
1072 	 * hand, a negative resid causes us to loop sending 0-length
1073 	 * segments to the protocol.
1074 	 */
1075 	if (resid < 0) {
1076 		error = EINVAL;
1077 		goto out;
1078 	}
1079 
1080 	dontroute =
1081 	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0;
1082 	if (td != NULL)
1083 		td->td_ru.ru_msgsnd++;
1084 	if (control != NULL)
1085 		clen = control->m_len;
1086 
1087 	SOCKBUF_LOCK(&so->so_snd);
1088 	if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
1089 		SOCKBUF_UNLOCK(&so->so_snd);
1090 		error = EPIPE;
1091 		goto out;
1092 	}
1093 	if (so->so_error) {
1094 		error = so->so_error;
1095 		so->so_error = 0;
1096 		SOCKBUF_UNLOCK(&so->so_snd);
1097 		goto out;
1098 	}
1099 	if ((so->so_state & SS_ISCONNECTED) == 0) {
1100 		/*
1101 		 * `sendto' and `sendmsg' is allowed on a connection-based
1102 		 * socket if it supports implied connect.  Return ENOTCONN if
1103 		 * not connected and no address is supplied.
1104 		 */
1105 		if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
1106 		    (so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
1107 			if ((so->so_state & SS_ISCONFIRMING) == 0 &&
1108 			    !(resid == 0 && clen != 0)) {
1109 				SOCKBUF_UNLOCK(&so->so_snd);
1110 				error = ENOTCONN;
1111 				goto out;
1112 			}
1113 		} else if (addr == NULL) {
1114 			if (so->so_proto->pr_flags & PR_CONNREQUIRED)
1115 				error = ENOTCONN;
1116 			else
1117 				error = EDESTADDRREQ;
1118 			SOCKBUF_UNLOCK(&so->so_snd);
1119 			goto out;
1120 		}
1121 	}
1122 
1123 	/*
1124 	 * Do we need MSG_OOB support in SOCK_DGRAM?  Signs here may be a
1125 	 * problem and need fixing.
1126 	 */
1127 	space = sbspace(&so->so_snd);
1128 	if (flags & MSG_OOB)
1129 		space += 1024;
1130 	space -= clen;
1131 	SOCKBUF_UNLOCK(&so->so_snd);
1132 	if (resid > space) {
1133 		error = EMSGSIZE;
1134 		goto out;
1135 	}
1136 	if (uio == NULL) {
1137 		resid = 0;
1138 		if (flags & MSG_EOR)
1139 			top->m_flags |= M_EOR;
1140 	} else {
1141 		/*
1142 		 * Copy the data from userland into a mbuf chain.
1143 		 * If no data is to be copied in, a single empty mbuf
1144 		 * is returned.
1145 		 */
1146 		top = m_uiotombuf(uio, M_WAITOK, space, max_hdr,
1147 		    (M_PKTHDR | ((flags & MSG_EOR) ? M_EOR : 0)));
1148 		if (top == NULL) {
1149 			error = EFAULT;	/* only possible error */
1150 			goto out;
1151 		}
1152 		space -= resid - uio->uio_resid;
1153 		resid = uio->uio_resid;
1154 	}
1155 	KASSERT(resid == 0, ("sosend_dgram: resid != 0"));
1156 	/*
1157 	 * XXXRW: Frobbing SO_DONTROUTE here is even worse without sblock
1158 	 * than with.
1159 	 */
1160 	if (dontroute) {
1161 		SOCK_LOCK(so);
1162 		so->so_options |= SO_DONTROUTE;
1163 		SOCK_UNLOCK(so);
1164 	}
1165 	/*
1166 	 * XXX all the SBS_CANTSENDMORE checks previously done could be out
1167 	 * of date.  We could have received a reset packet in an interrupt or
1168 	 * maybe we slept while doing page faults in uiomove() etc.  We could
1169 	 * probably recheck again inside the locking protection here, but
1170 	 * there are probably other places that this also happens.  We must
1171 	 * rethink this.
1172 	 */
1173 	VNET_SO_ASSERT(so);
1174 	error = (*so->so_proto->pr_usrreqs->pru_send)(so,
1175 	    (flags & MSG_OOB) ? PRUS_OOB :
1176 	/*
1177 	 * If the user set MSG_EOF, the protocol understands this flag and
1178 	 * nothing left to send then use PRU_SEND_EOF instead of PRU_SEND.
1179 	 */
1180 	    ((flags & MSG_EOF) &&
1181 	     (so->so_proto->pr_flags & PR_IMPLOPCL) &&
1182 	     (resid <= 0)) ?
1183 		PRUS_EOF :
1184 		/* If there is more to send set PRUS_MORETOCOME */
1185 		(flags & MSG_MORETOCOME) ||
1186 		(resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
1187 		top, addr, control, td);
1188 	if (dontroute) {
1189 		SOCK_LOCK(so);
1190 		so->so_options &= ~SO_DONTROUTE;
1191 		SOCK_UNLOCK(so);
1192 	}
1193 	clen = 0;
1194 	control = NULL;
1195 	top = NULL;
1196 out:
1197 	if (top != NULL)
1198 		m_freem(top);
1199 	if (control != NULL)
1200 		m_freem(control);
1201 	return (error);
1202 }
1203 
1204 /*
1205  * Send on a socket.  If send must go all at once and message is larger than
1206  * send buffering, then hard error.  Lock against other senders.  If must go
1207  * all at once and not enough room now, then inform user that this would
1208  * block and do nothing.  Otherwise, if nonblocking, send as much as
1209  * possible.  The data to be sent is described by "uio" if nonzero, otherwise
1210  * by the mbuf chain "top" (which must be null if uio is not).  Data provided
1211  * in mbuf chain must be small enough to send all at once.
1212  *
1213  * Returns nonzero on error, timeout or signal; callers must check for short
1214  * counts if EINTR/ERESTART are returned.  Data and control buffers are freed
1215  * on return.
1216  */
1217 int
1218 sosend_generic(struct socket *so, struct sockaddr *addr, struct uio *uio,
1219     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
1220 {
1221 	long space;
1222 	ssize_t resid;
1223 	int clen = 0, error, dontroute;
1224 	int atomic = sosendallatonce(so) || top;
1225 
1226 	if (uio != NULL)
1227 		resid = uio->uio_resid;
1228 	else
1229 		resid = top->m_pkthdr.len;
1230 	/*
1231 	 * In theory resid should be unsigned.  However, space must be
1232 	 * signed, as it might be less than 0 if we over-committed, and we
1233 	 * must use a signed comparison of space and resid.  On the other
1234 	 * hand, a negative resid causes us to loop sending 0-length
1235 	 * segments to the protocol.
1236 	 *
1237 	 * Also check to make sure that MSG_EOR isn't used on SOCK_STREAM
1238 	 * type sockets since that's an error.
1239 	 */
1240 	if (resid < 0 || (so->so_type == SOCK_STREAM && (flags & MSG_EOR))) {
1241 		error = EINVAL;
1242 		goto out;
1243 	}
1244 
1245 	dontroute =
1246 	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
1247 	    (so->so_proto->pr_flags & PR_ATOMIC);
1248 	if (td != NULL)
1249 		td->td_ru.ru_msgsnd++;
1250 	if (control != NULL)
1251 		clen = control->m_len;
1252 
1253 	error = sblock(&so->so_snd, SBLOCKWAIT(flags));
1254 	if (error)
1255 		goto out;
1256 
1257 restart:
1258 	do {
1259 		SOCKBUF_LOCK(&so->so_snd);
1260 		if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
1261 			SOCKBUF_UNLOCK(&so->so_snd);
1262 			error = EPIPE;
1263 			goto release;
1264 		}
1265 		if (so->so_error) {
1266 			error = so->so_error;
1267 			so->so_error = 0;
1268 			SOCKBUF_UNLOCK(&so->so_snd);
1269 			goto release;
1270 		}
1271 		if ((so->so_state & SS_ISCONNECTED) == 0) {
1272 			/*
1273 			 * `sendto' and `sendmsg' is allowed on a connection-
1274 			 * based socket if it supports implied connect.
1275 			 * Return ENOTCONN if not connected and no address is
1276 			 * supplied.
1277 			 */
1278 			if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
1279 			    (so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
1280 				if ((so->so_state & SS_ISCONFIRMING) == 0 &&
1281 				    !(resid == 0 && clen != 0)) {
1282 					SOCKBUF_UNLOCK(&so->so_snd);
1283 					error = ENOTCONN;
1284 					goto release;
1285 				}
1286 			} else if (addr == NULL) {
1287 				SOCKBUF_UNLOCK(&so->so_snd);
1288 				if (so->so_proto->pr_flags & PR_CONNREQUIRED)
1289 					error = ENOTCONN;
1290 				else
1291 					error = EDESTADDRREQ;
1292 				goto release;
1293 			}
1294 		}
1295 		space = sbspace(&so->so_snd);
1296 		if (flags & MSG_OOB)
1297 			space += 1024;
1298 		if ((atomic && resid > so->so_snd.sb_hiwat) ||
1299 		    clen > so->so_snd.sb_hiwat) {
1300 			SOCKBUF_UNLOCK(&so->so_snd);
1301 			error = EMSGSIZE;
1302 			goto release;
1303 		}
1304 		if (space < resid + clen &&
1305 		    (atomic || space < so->so_snd.sb_lowat || space < clen)) {
1306 			if ((so->so_state & SS_NBIO) || (flags & MSG_NBIO)) {
1307 				SOCKBUF_UNLOCK(&so->so_snd);
1308 				error = EWOULDBLOCK;
1309 				goto release;
1310 			}
1311 			error = sbwait(&so->so_snd);
1312 			SOCKBUF_UNLOCK(&so->so_snd);
1313 			if (error)
1314 				goto release;
1315 			goto restart;
1316 		}
1317 		SOCKBUF_UNLOCK(&so->so_snd);
1318 		space -= clen;
1319 		do {
1320 			if (uio == NULL) {
1321 				resid = 0;
1322 				if (flags & MSG_EOR)
1323 					top->m_flags |= M_EOR;
1324 			} else {
1325 				/*
1326 				 * Copy the data from userland into a mbuf
1327 				 * chain.  If resid is 0, which can happen
1328 				 * only if we have control to send, then
1329 				 * a single empty mbuf is returned.  This
1330 				 * is a workaround to prevent protocol send
1331 				 * methods to panic.
1332 				 */
1333 				top = m_uiotombuf(uio, M_WAITOK, space,
1334 				    (atomic ? max_hdr : 0),
1335 				    (atomic ? M_PKTHDR : 0) |
1336 				    ((flags & MSG_EOR) ? M_EOR : 0));
1337 				if (top == NULL) {
1338 					error = EFAULT; /* only possible error */
1339 					goto release;
1340 				}
1341 				space -= resid - uio->uio_resid;
1342 				resid = uio->uio_resid;
1343 			}
1344 			if (dontroute) {
1345 				SOCK_LOCK(so);
1346 				so->so_options |= SO_DONTROUTE;
1347 				SOCK_UNLOCK(so);
1348 			}
1349 			/*
1350 			 * XXX all the SBS_CANTSENDMORE checks previously
1351 			 * done could be out of date.  We could have received
1352 			 * a reset packet in an interrupt or maybe we slept
1353 			 * while doing page faults in uiomove() etc.  We
1354 			 * could probably recheck again inside the locking
1355 			 * protection here, but there are probably other
1356 			 * places that this also happens.  We must rethink
1357 			 * this.
1358 			 */
1359 			VNET_SO_ASSERT(so);
1360 			error = (*so->so_proto->pr_usrreqs->pru_send)(so,
1361 			    (flags & MSG_OOB) ? PRUS_OOB :
1362 			/*
1363 			 * If the user set MSG_EOF, the protocol understands
1364 			 * this flag and nothing left to send then use
1365 			 * PRU_SEND_EOF instead of PRU_SEND.
1366 			 */
1367 			    ((flags & MSG_EOF) &&
1368 			     (so->so_proto->pr_flags & PR_IMPLOPCL) &&
1369 			     (resid <= 0)) ?
1370 				PRUS_EOF :
1371 			/* If there is more to send set PRUS_MORETOCOME. */
1372 			    (flags & MSG_MORETOCOME) ||
1373 			    (resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
1374 			    top, addr, control, td);
1375 			if (dontroute) {
1376 				SOCK_LOCK(so);
1377 				so->so_options &= ~SO_DONTROUTE;
1378 				SOCK_UNLOCK(so);
1379 			}
1380 			clen = 0;
1381 			control = NULL;
1382 			top = NULL;
1383 			if (error)
1384 				goto release;
1385 		} while (resid && space > 0);
1386 	} while (resid);
1387 
1388 release:
1389 	sbunlock(&so->so_snd);
1390 out:
1391 	if (top != NULL)
1392 		m_freem(top);
1393 	if (control != NULL)
1394 		m_freem(control);
1395 	return (error);
1396 }
1397 
1398 int
1399 sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
1400     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
1401 {
1402 	int error;
1403 
1404 	CURVNET_SET(so->so_vnet);
1405 	error = so->so_proto->pr_usrreqs->pru_sosend(so, addr, uio, top,
1406 	    control, flags, td);
1407 	CURVNET_RESTORE();
1408 	return (error);
1409 }
1410 
1411 /*
1412  * The part of soreceive() that implements reading non-inline out-of-band
1413  * data from a socket.  For more complete comments, see soreceive(), from
1414  * which this code originated.
1415  *
1416  * Note that soreceive_rcvoob(), unlike the remainder of soreceive(), is
1417  * unable to return an mbuf chain to the caller.
1418  */
1419 static int
1420 soreceive_rcvoob(struct socket *so, struct uio *uio, int flags)
1421 {
1422 	struct protosw *pr = so->so_proto;
1423 	struct mbuf *m;
1424 	int error;
1425 
1426 	KASSERT(flags & MSG_OOB, ("soreceive_rcvoob: (flags & MSG_OOB) == 0"));
1427 	VNET_SO_ASSERT(so);
1428 
1429 	m = m_get(M_WAITOK, MT_DATA);
1430 	error = (*pr->pr_usrreqs->pru_rcvoob)(so, m, flags & MSG_PEEK);
1431 	if (error)
1432 		goto bad;
1433 	do {
1434 		error = uiomove(mtod(m, void *),
1435 		    (int) min(uio->uio_resid, m->m_len), uio);
1436 		m = m_free(m);
1437 	} while (uio->uio_resid && error == 0 && m);
1438 bad:
1439 	if (m != NULL)
1440 		m_freem(m);
1441 	return (error);
1442 }
1443 
1444 /*
1445  * Following replacement or removal of the first mbuf on the first mbuf chain
1446  * of a socket buffer, push necessary state changes back into the socket
1447  * buffer so that other consumers see the values consistently.  'nextrecord'
1448  * is the callers locally stored value of the original value of
1449  * sb->sb_mb->m_nextpkt which must be restored when the lead mbuf changes.
1450  * NOTE: 'nextrecord' may be NULL.
1451  */
1452 static __inline void
1453 sockbuf_pushsync(struct sockbuf *sb, struct mbuf *nextrecord)
1454 {
1455 
1456 	SOCKBUF_LOCK_ASSERT(sb);
1457 	/*
1458 	 * First, update for the new value of nextrecord.  If necessary, make
1459 	 * it the first record.
1460 	 */
1461 	if (sb->sb_mb != NULL)
1462 		sb->sb_mb->m_nextpkt = nextrecord;
1463 	else
1464 		sb->sb_mb = nextrecord;
1465 
1466 	/*
1467 	 * Now update any dependent socket buffer fields to reflect the new
1468 	 * state.  This is an expanded inline of SB_EMPTY_FIXUP(), with the
1469 	 * addition of a second clause that takes care of the case where
1470 	 * sb_mb has been updated, but remains the last record.
1471 	 */
1472 	if (sb->sb_mb == NULL) {
1473 		sb->sb_mbtail = NULL;
1474 		sb->sb_lastrecord = NULL;
1475 	} else if (sb->sb_mb->m_nextpkt == NULL)
1476 		sb->sb_lastrecord = sb->sb_mb;
1477 }
1478 
1479 /*
1480  * Implement receive operations on a socket.  We depend on the way that
1481  * records are added to the sockbuf by sbappend.  In particular, each record
1482  * (mbufs linked through m_next) must begin with an address if the protocol
1483  * so specifies, followed by an optional mbuf or mbufs containing ancillary
1484  * data, and then zero or more mbufs of data.  In order to allow parallelism
1485  * between network receive and copying to user space, as well as avoid
1486  * sleeping with a mutex held, we release the socket buffer mutex during the
1487  * user space copy.  Although the sockbuf is locked, new data may still be
1488  * appended, and thus we must maintain consistency of the sockbuf during that
1489  * time.
1490  *
1491  * The caller may receive the data as a single mbuf chain by supplying an
1492  * mbuf **mp0 for use in returning the chain.  The uio is then used only for
1493  * the count in uio_resid.
1494  */
1495 int
1496 soreceive_generic(struct socket *so, struct sockaddr **psa, struct uio *uio,
1497     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
1498 {
1499 	struct mbuf *m, **mp;
1500 	int flags, error, offset;
1501 	ssize_t len;
1502 	struct protosw *pr = so->so_proto;
1503 	struct mbuf *nextrecord;
1504 	int moff, type = 0;
1505 	ssize_t orig_resid = uio->uio_resid;
1506 
1507 	mp = mp0;
1508 	if (psa != NULL)
1509 		*psa = NULL;
1510 	if (controlp != NULL)
1511 		*controlp = NULL;
1512 	if (flagsp != NULL)
1513 		flags = *flagsp &~ MSG_EOR;
1514 	else
1515 		flags = 0;
1516 	if (flags & MSG_OOB)
1517 		return (soreceive_rcvoob(so, uio, flags));
1518 	if (mp != NULL)
1519 		*mp = NULL;
1520 	if ((pr->pr_flags & PR_WANTRCVD) && (so->so_state & SS_ISCONFIRMING)
1521 	    && uio->uio_resid) {
1522 		VNET_SO_ASSERT(so);
1523 		(*pr->pr_usrreqs->pru_rcvd)(so, 0);
1524 	}
1525 
1526 	error = sblock(&so->so_rcv, SBLOCKWAIT(flags));
1527 	if (error)
1528 		return (error);
1529 
1530 restart:
1531 	SOCKBUF_LOCK(&so->so_rcv);
1532 	m = so->so_rcv.sb_mb;
1533 	/*
1534 	 * If we have less data than requested, block awaiting more (subject
1535 	 * to any timeout) if:
1536 	 *   1. the current count is less than the low water mark, or
1537 	 *   2. MSG_DONTWAIT is not set
1538 	 */
1539 	if (m == NULL || (((flags & MSG_DONTWAIT) == 0 &&
1540 	    sbavail(&so->so_rcv) < uio->uio_resid) &&
1541 	    sbavail(&so->so_rcv) < so->so_rcv.sb_lowat &&
1542 	    m->m_nextpkt == NULL && (pr->pr_flags & PR_ATOMIC) == 0)) {
1543 		KASSERT(m != NULL || !sbavail(&so->so_rcv),
1544 		    ("receive: m == %p sbavail == %u",
1545 		    m, sbavail(&so->so_rcv)));
1546 		if (so->so_error) {
1547 			if (m != NULL)
1548 				goto dontblock;
1549 			error = so->so_error;
1550 			if ((flags & MSG_PEEK) == 0)
1551 				so->so_error = 0;
1552 			SOCKBUF_UNLOCK(&so->so_rcv);
1553 			goto release;
1554 		}
1555 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1556 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
1557 			if (m == NULL) {
1558 				SOCKBUF_UNLOCK(&so->so_rcv);
1559 				goto release;
1560 			} else
1561 				goto dontblock;
1562 		}
1563 		for (; m != NULL; m = m->m_next)
1564 			if (m->m_type == MT_OOBDATA  || (m->m_flags & M_EOR)) {
1565 				m = so->so_rcv.sb_mb;
1566 				goto dontblock;
1567 			}
1568 		if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
1569 		    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
1570 			SOCKBUF_UNLOCK(&so->so_rcv);
1571 			error = ENOTCONN;
1572 			goto release;
1573 		}
1574 		if (uio->uio_resid == 0) {
1575 			SOCKBUF_UNLOCK(&so->so_rcv);
1576 			goto release;
1577 		}
1578 		if ((so->so_state & SS_NBIO) ||
1579 		    (flags & (MSG_DONTWAIT|MSG_NBIO))) {
1580 			SOCKBUF_UNLOCK(&so->so_rcv);
1581 			error = EWOULDBLOCK;
1582 			goto release;
1583 		}
1584 		SBLASTRECORDCHK(&so->so_rcv);
1585 		SBLASTMBUFCHK(&so->so_rcv);
1586 		error = sbwait(&so->so_rcv);
1587 		SOCKBUF_UNLOCK(&so->so_rcv);
1588 		if (error)
1589 			goto release;
1590 		goto restart;
1591 	}
1592 dontblock:
1593 	/*
1594 	 * From this point onward, we maintain 'nextrecord' as a cache of the
1595 	 * pointer to the next record in the socket buffer.  We must keep the
1596 	 * various socket buffer pointers and local stack versions of the
1597 	 * pointers in sync, pushing out modifications before dropping the
1598 	 * socket buffer mutex, and re-reading them when picking it up.
1599 	 *
1600 	 * Otherwise, we will race with the network stack appending new data
1601 	 * or records onto the socket buffer by using inconsistent/stale
1602 	 * versions of the field, possibly resulting in socket buffer
1603 	 * corruption.
1604 	 *
1605 	 * By holding the high-level sblock(), we prevent simultaneous
1606 	 * readers from pulling off the front of the socket buffer.
1607 	 */
1608 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1609 	if (uio->uio_td)
1610 		uio->uio_td->td_ru.ru_msgrcv++;
1611 	KASSERT(m == so->so_rcv.sb_mb, ("soreceive: m != so->so_rcv.sb_mb"));
1612 	SBLASTRECORDCHK(&so->so_rcv);
1613 	SBLASTMBUFCHK(&so->so_rcv);
1614 	nextrecord = m->m_nextpkt;
1615 	if (pr->pr_flags & PR_ADDR) {
1616 		KASSERT(m->m_type == MT_SONAME,
1617 		    ("m->m_type == %d", m->m_type));
1618 		orig_resid = 0;
1619 		if (psa != NULL)
1620 			*psa = sodupsockaddr(mtod(m, struct sockaddr *),
1621 			    M_NOWAIT);
1622 		if (flags & MSG_PEEK) {
1623 			m = m->m_next;
1624 		} else {
1625 			sbfree(&so->so_rcv, m);
1626 			so->so_rcv.sb_mb = m_free(m);
1627 			m = so->so_rcv.sb_mb;
1628 			sockbuf_pushsync(&so->so_rcv, nextrecord);
1629 		}
1630 	}
1631 
1632 	/*
1633 	 * Process one or more MT_CONTROL mbufs present before any data mbufs
1634 	 * in the first mbuf chain on the socket buffer.  If MSG_PEEK, we
1635 	 * just copy the data; if !MSG_PEEK, we call into the protocol to
1636 	 * perform externalization (or freeing if controlp == NULL).
1637 	 */
1638 	if (m != NULL && m->m_type == MT_CONTROL) {
1639 		struct mbuf *cm = NULL, *cmn;
1640 		struct mbuf **cme = &cm;
1641 
1642 		do {
1643 			if (flags & MSG_PEEK) {
1644 				if (controlp != NULL) {
1645 					*controlp = m_copym(m, 0, m->m_len,
1646 					    M_NOWAIT);
1647 					controlp = &(*controlp)->m_next;
1648 				}
1649 				m = m->m_next;
1650 			} else {
1651 				sbfree(&so->so_rcv, m);
1652 				so->so_rcv.sb_mb = m->m_next;
1653 				m->m_next = NULL;
1654 				*cme = m;
1655 				cme = &(*cme)->m_next;
1656 				m = so->so_rcv.sb_mb;
1657 			}
1658 		} while (m != NULL && m->m_type == MT_CONTROL);
1659 		if ((flags & MSG_PEEK) == 0)
1660 			sockbuf_pushsync(&so->so_rcv, nextrecord);
1661 		while (cm != NULL) {
1662 			cmn = cm->m_next;
1663 			cm->m_next = NULL;
1664 			if (pr->pr_domain->dom_externalize != NULL) {
1665 				SOCKBUF_UNLOCK(&so->so_rcv);
1666 				VNET_SO_ASSERT(so);
1667 				error = (*pr->pr_domain->dom_externalize)
1668 				    (cm, controlp, flags);
1669 				SOCKBUF_LOCK(&so->so_rcv);
1670 			} else if (controlp != NULL)
1671 				*controlp = cm;
1672 			else
1673 				m_freem(cm);
1674 			if (controlp != NULL) {
1675 				orig_resid = 0;
1676 				while (*controlp != NULL)
1677 					controlp = &(*controlp)->m_next;
1678 			}
1679 			cm = cmn;
1680 		}
1681 		if (m != NULL)
1682 			nextrecord = so->so_rcv.sb_mb->m_nextpkt;
1683 		else
1684 			nextrecord = so->so_rcv.sb_mb;
1685 		orig_resid = 0;
1686 	}
1687 	if (m != NULL) {
1688 		if ((flags & MSG_PEEK) == 0) {
1689 			KASSERT(m->m_nextpkt == nextrecord,
1690 			    ("soreceive: post-control, nextrecord !sync"));
1691 			if (nextrecord == NULL) {
1692 				KASSERT(so->so_rcv.sb_mb == m,
1693 				    ("soreceive: post-control, sb_mb!=m"));
1694 				KASSERT(so->so_rcv.sb_lastrecord == m,
1695 				    ("soreceive: post-control, lastrecord!=m"));
1696 			}
1697 		}
1698 		type = m->m_type;
1699 		if (type == MT_OOBDATA)
1700 			flags |= MSG_OOB;
1701 	} else {
1702 		if ((flags & MSG_PEEK) == 0) {
1703 			KASSERT(so->so_rcv.sb_mb == nextrecord,
1704 			    ("soreceive: sb_mb != nextrecord"));
1705 			if (so->so_rcv.sb_mb == NULL) {
1706 				KASSERT(so->so_rcv.sb_lastrecord == NULL,
1707 				    ("soreceive: sb_lastercord != NULL"));
1708 			}
1709 		}
1710 	}
1711 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1712 	SBLASTRECORDCHK(&so->so_rcv);
1713 	SBLASTMBUFCHK(&so->so_rcv);
1714 
1715 	/*
1716 	 * Now continue to read any data mbufs off of the head of the socket
1717 	 * buffer until the read request is satisfied.  Note that 'type' is
1718 	 * used to store the type of any mbuf reads that have happened so far
1719 	 * such that soreceive() can stop reading if the type changes, which
1720 	 * causes soreceive() to return only one of regular data and inline
1721 	 * out-of-band data in a single socket receive operation.
1722 	 */
1723 	moff = 0;
1724 	offset = 0;
1725 	while (m != NULL && !(m->m_flags & M_NOTAVAIL) && uio->uio_resid > 0
1726 	    && error == 0) {
1727 		/*
1728 		 * If the type of mbuf has changed since the last mbuf
1729 		 * examined ('type'), end the receive operation.
1730 		 */
1731 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1732 		if (m->m_type == MT_OOBDATA || m->m_type == MT_CONTROL) {
1733 			if (type != m->m_type)
1734 				break;
1735 		} else if (type == MT_OOBDATA)
1736 			break;
1737 		else
1738 		    KASSERT(m->m_type == MT_DATA,
1739 			("m->m_type == %d", m->m_type));
1740 		so->so_rcv.sb_state &= ~SBS_RCVATMARK;
1741 		len = uio->uio_resid;
1742 		if (so->so_oobmark && len > so->so_oobmark - offset)
1743 			len = so->so_oobmark - offset;
1744 		if (len > m->m_len - moff)
1745 			len = m->m_len - moff;
1746 		/*
1747 		 * If mp is set, just pass back the mbufs.  Otherwise copy
1748 		 * them out via the uio, then free.  Sockbuf must be
1749 		 * consistent here (points to current mbuf, it points to next
1750 		 * record) when we drop priority; we must note any additions
1751 		 * to the sockbuf when we block interrupts again.
1752 		 */
1753 		if (mp == NULL) {
1754 			SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1755 			SBLASTRECORDCHK(&so->so_rcv);
1756 			SBLASTMBUFCHK(&so->so_rcv);
1757 			SOCKBUF_UNLOCK(&so->so_rcv);
1758 			error = uiomove(mtod(m, char *) + moff, (int)len, uio);
1759 			SOCKBUF_LOCK(&so->so_rcv);
1760 			if (error) {
1761 				/*
1762 				 * The MT_SONAME mbuf has already been removed
1763 				 * from the record, so it is necessary to
1764 				 * remove the data mbufs, if any, to preserve
1765 				 * the invariant in the case of PR_ADDR that
1766 				 * requires MT_SONAME mbufs at the head of
1767 				 * each record.
1768 				 */
1769 				if (m && pr->pr_flags & PR_ATOMIC &&
1770 				    ((flags & MSG_PEEK) == 0))
1771 					(void)sbdroprecord_locked(&so->so_rcv);
1772 				SOCKBUF_UNLOCK(&so->so_rcv);
1773 				goto release;
1774 			}
1775 		} else
1776 			uio->uio_resid -= len;
1777 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1778 		if (len == m->m_len - moff) {
1779 			if (m->m_flags & M_EOR)
1780 				flags |= MSG_EOR;
1781 			if (flags & MSG_PEEK) {
1782 				m = m->m_next;
1783 				moff = 0;
1784 			} else {
1785 				nextrecord = m->m_nextpkt;
1786 				sbfree(&so->so_rcv, m);
1787 				if (mp != NULL) {
1788 					m->m_nextpkt = NULL;
1789 					*mp = m;
1790 					mp = &m->m_next;
1791 					so->so_rcv.sb_mb = m = m->m_next;
1792 					*mp = NULL;
1793 				} else {
1794 					so->so_rcv.sb_mb = m_free(m);
1795 					m = so->so_rcv.sb_mb;
1796 				}
1797 				sockbuf_pushsync(&so->so_rcv, nextrecord);
1798 				SBLASTRECORDCHK(&so->so_rcv);
1799 				SBLASTMBUFCHK(&so->so_rcv);
1800 			}
1801 		} else {
1802 			if (flags & MSG_PEEK)
1803 				moff += len;
1804 			else {
1805 				if (mp != NULL) {
1806 					if (flags & MSG_DONTWAIT) {
1807 						*mp = m_copym(m, 0, len,
1808 						    M_NOWAIT);
1809 						if (*mp == NULL) {
1810 							/*
1811 							 * m_copym() couldn't
1812 							 * allocate an mbuf.
1813 							 * Adjust uio_resid back
1814 							 * (it was adjusted
1815 							 * down by len bytes,
1816 							 * which we didn't end
1817 							 * up "copying" over).
1818 							 */
1819 							uio->uio_resid += len;
1820 							break;
1821 						}
1822 					} else {
1823 						SOCKBUF_UNLOCK(&so->so_rcv);
1824 						*mp = m_copym(m, 0, len,
1825 						    M_WAITOK);
1826 						SOCKBUF_LOCK(&so->so_rcv);
1827 					}
1828 				}
1829 				sbcut_locked(&so->so_rcv, len);
1830 			}
1831 		}
1832 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1833 		if (so->so_oobmark) {
1834 			if ((flags & MSG_PEEK) == 0) {
1835 				so->so_oobmark -= len;
1836 				if (so->so_oobmark == 0) {
1837 					so->so_rcv.sb_state |= SBS_RCVATMARK;
1838 					break;
1839 				}
1840 			} else {
1841 				offset += len;
1842 				if (offset == so->so_oobmark)
1843 					break;
1844 			}
1845 		}
1846 		if (flags & MSG_EOR)
1847 			break;
1848 		/*
1849 		 * If the MSG_WAITALL flag is set (for non-atomic socket), we
1850 		 * must not quit until "uio->uio_resid == 0" or an error
1851 		 * termination.  If a signal/timeout occurs, return with a
1852 		 * short count but without error.  Keep sockbuf locked
1853 		 * against other readers.
1854 		 */
1855 		while (flags & MSG_WAITALL && m == NULL && uio->uio_resid > 0 &&
1856 		    !sosendallatonce(so) && nextrecord == NULL) {
1857 			SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1858 			if (so->so_error ||
1859 			    so->so_rcv.sb_state & SBS_CANTRCVMORE)
1860 				break;
1861 			/*
1862 			 * Notify the protocol that some data has been
1863 			 * drained before blocking.
1864 			 */
1865 			if (pr->pr_flags & PR_WANTRCVD) {
1866 				SOCKBUF_UNLOCK(&so->so_rcv);
1867 				VNET_SO_ASSERT(so);
1868 				(*pr->pr_usrreqs->pru_rcvd)(so, flags);
1869 				SOCKBUF_LOCK(&so->so_rcv);
1870 			}
1871 			SBLASTRECORDCHK(&so->so_rcv);
1872 			SBLASTMBUFCHK(&so->so_rcv);
1873 			/*
1874 			 * We could receive some data while was notifying
1875 			 * the protocol. Skip blocking in this case.
1876 			 */
1877 			if (so->so_rcv.sb_mb == NULL) {
1878 				error = sbwait(&so->so_rcv);
1879 				if (error) {
1880 					SOCKBUF_UNLOCK(&so->so_rcv);
1881 					goto release;
1882 				}
1883 			}
1884 			m = so->so_rcv.sb_mb;
1885 			if (m != NULL)
1886 				nextrecord = m->m_nextpkt;
1887 		}
1888 	}
1889 
1890 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1891 	if (m != NULL && pr->pr_flags & PR_ATOMIC) {
1892 		flags |= MSG_TRUNC;
1893 		if ((flags & MSG_PEEK) == 0)
1894 			(void) sbdroprecord_locked(&so->so_rcv);
1895 	}
1896 	if ((flags & MSG_PEEK) == 0) {
1897 		if (m == NULL) {
1898 			/*
1899 			 * First part is an inline SB_EMPTY_FIXUP().  Second
1900 			 * part makes sure sb_lastrecord is up-to-date if
1901 			 * there is still data in the socket buffer.
1902 			 */
1903 			so->so_rcv.sb_mb = nextrecord;
1904 			if (so->so_rcv.sb_mb == NULL) {
1905 				so->so_rcv.sb_mbtail = NULL;
1906 				so->so_rcv.sb_lastrecord = NULL;
1907 			} else if (nextrecord->m_nextpkt == NULL)
1908 				so->so_rcv.sb_lastrecord = nextrecord;
1909 		}
1910 		SBLASTRECORDCHK(&so->so_rcv);
1911 		SBLASTMBUFCHK(&so->so_rcv);
1912 		/*
1913 		 * If soreceive() is being done from the socket callback,
1914 		 * then don't need to generate ACK to peer to update window,
1915 		 * since ACK will be generated on return to TCP.
1916 		 */
1917 		if (!(flags & MSG_SOCALLBCK) &&
1918 		    (pr->pr_flags & PR_WANTRCVD)) {
1919 			SOCKBUF_UNLOCK(&so->so_rcv);
1920 			VNET_SO_ASSERT(so);
1921 			(*pr->pr_usrreqs->pru_rcvd)(so, flags);
1922 			SOCKBUF_LOCK(&so->so_rcv);
1923 		}
1924 	}
1925 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1926 	if (orig_resid == uio->uio_resid && orig_resid &&
1927 	    (flags & MSG_EOR) == 0 && (so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0) {
1928 		SOCKBUF_UNLOCK(&so->so_rcv);
1929 		goto restart;
1930 	}
1931 	SOCKBUF_UNLOCK(&so->so_rcv);
1932 
1933 	if (flagsp != NULL)
1934 		*flagsp |= flags;
1935 release:
1936 	sbunlock(&so->so_rcv);
1937 	return (error);
1938 }
1939 
1940 /*
1941  * Optimized version of soreceive() for stream (TCP) sockets.
1942  * XXXAO: (MSG_WAITALL | MSG_PEEK) isn't properly handled.
1943  */
1944 int
1945 soreceive_stream(struct socket *so, struct sockaddr **psa, struct uio *uio,
1946     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
1947 {
1948 	int len = 0, error = 0, flags, oresid;
1949 	struct sockbuf *sb;
1950 	struct mbuf *m, *n = NULL;
1951 
1952 	/* We only do stream sockets. */
1953 	if (so->so_type != SOCK_STREAM)
1954 		return (EINVAL);
1955 	if (psa != NULL)
1956 		*psa = NULL;
1957 	if (controlp != NULL)
1958 		return (EINVAL);
1959 	if (flagsp != NULL)
1960 		flags = *flagsp &~ MSG_EOR;
1961 	else
1962 		flags = 0;
1963 	if (flags & MSG_OOB)
1964 		return (soreceive_rcvoob(so, uio, flags));
1965 	if (mp0 != NULL)
1966 		*mp0 = NULL;
1967 
1968 	sb = &so->so_rcv;
1969 
1970 	/* Prevent other readers from entering the socket. */
1971 	error = sblock(sb, SBLOCKWAIT(flags));
1972 	if (error)
1973 		goto out;
1974 	SOCKBUF_LOCK(sb);
1975 
1976 	/* Easy one, no space to copyout anything. */
1977 	if (uio->uio_resid == 0) {
1978 		error = EINVAL;
1979 		goto out;
1980 	}
1981 	oresid = uio->uio_resid;
1982 
1983 	/* We will never ever get anything unless we are or were connected. */
1984 	if (!(so->so_state & (SS_ISCONNECTED|SS_ISDISCONNECTED))) {
1985 		error = ENOTCONN;
1986 		goto out;
1987 	}
1988 
1989 restart:
1990 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1991 
1992 	/* Abort if socket has reported problems. */
1993 	if (so->so_error) {
1994 		if (sbavail(sb) > 0)
1995 			goto deliver;
1996 		if (oresid > uio->uio_resid)
1997 			goto out;
1998 		error = so->so_error;
1999 		if (!(flags & MSG_PEEK))
2000 			so->so_error = 0;
2001 		goto out;
2002 	}
2003 
2004 	/* Door is closed.  Deliver what is left, if any. */
2005 	if (sb->sb_state & SBS_CANTRCVMORE) {
2006 		if (sbavail(sb) > 0)
2007 			goto deliver;
2008 		else
2009 			goto out;
2010 	}
2011 
2012 	/* Socket buffer is empty and we shall not block. */
2013 	if (sbavail(sb) == 0 &&
2014 	    ((so->so_state & SS_NBIO) || (flags & (MSG_DONTWAIT|MSG_NBIO)))) {
2015 		error = EAGAIN;
2016 		goto out;
2017 	}
2018 
2019 	/* Socket buffer got some data that we shall deliver now. */
2020 	if (sbavail(sb) > 0 && !(flags & MSG_WAITALL) &&
2021 	    ((so->so_state & SS_NBIO) ||
2022 	     (flags & (MSG_DONTWAIT|MSG_NBIO)) ||
2023 	     sbavail(sb) >= sb->sb_lowat ||
2024 	     sbavail(sb) >= uio->uio_resid ||
2025 	     sbavail(sb) >= sb->sb_hiwat) ) {
2026 		goto deliver;
2027 	}
2028 
2029 	/* On MSG_WAITALL we must wait until all data or error arrives. */
2030 	if ((flags & MSG_WAITALL) &&
2031 	    (sbavail(sb) >= uio->uio_resid || sbavail(sb) >= sb->sb_hiwat))
2032 		goto deliver;
2033 
2034 	/*
2035 	 * Wait and block until (more) data comes in.
2036 	 * NB: Drops the sockbuf lock during wait.
2037 	 */
2038 	error = sbwait(sb);
2039 	if (error)
2040 		goto out;
2041 	goto restart;
2042 
2043 deliver:
2044 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2045 	KASSERT(sbavail(sb) > 0, ("%s: sockbuf empty", __func__));
2046 	KASSERT(sb->sb_mb != NULL, ("%s: sb_mb == NULL", __func__));
2047 
2048 	/* Statistics. */
2049 	if (uio->uio_td)
2050 		uio->uio_td->td_ru.ru_msgrcv++;
2051 
2052 	/* Fill uio until full or current end of socket buffer is reached. */
2053 	len = min(uio->uio_resid, sbavail(sb));
2054 	if (mp0 != NULL) {
2055 		/* Dequeue as many mbufs as possible. */
2056 		if (!(flags & MSG_PEEK) && len >= sb->sb_mb->m_len) {
2057 			if (*mp0 == NULL)
2058 				*mp0 = sb->sb_mb;
2059 			else
2060 				m_cat(*mp0, sb->sb_mb);
2061 			for (m = sb->sb_mb;
2062 			     m != NULL && m->m_len <= len;
2063 			     m = m->m_next) {
2064 				KASSERT(!(m->m_flags & M_NOTAVAIL),
2065 				    ("%s: m %p not available", __func__, m));
2066 				len -= m->m_len;
2067 				uio->uio_resid -= m->m_len;
2068 				sbfree(sb, m);
2069 				n = m;
2070 			}
2071 			n->m_next = NULL;
2072 			sb->sb_mb = m;
2073 			sb->sb_lastrecord = sb->sb_mb;
2074 			if (sb->sb_mb == NULL)
2075 				SB_EMPTY_FIXUP(sb);
2076 		}
2077 		/* Copy the remainder. */
2078 		if (len > 0) {
2079 			KASSERT(sb->sb_mb != NULL,
2080 			    ("%s: len > 0 && sb->sb_mb empty", __func__));
2081 
2082 			m = m_copym(sb->sb_mb, 0, len, M_NOWAIT);
2083 			if (m == NULL)
2084 				len = 0;	/* Don't flush data from sockbuf. */
2085 			else
2086 				uio->uio_resid -= len;
2087 			if (*mp0 != NULL)
2088 				m_cat(*mp0, m);
2089 			else
2090 				*mp0 = m;
2091 			if (*mp0 == NULL) {
2092 				error = ENOBUFS;
2093 				goto out;
2094 			}
2095 		}
2096 	} else {
2097 		/* NB: Must unlock socket buffer as uiomove may sleep. */
2098 		SOCKBUF_UNLOCK(sb);
2099 		error = m_mbuftouio(uio, sb->sb_mb, len);
2100 		SOCKBUF_LOCK(sb);
2101 		if (error)
2102 			goto out;
2103 	}
2104 	SBLASTRECORDCHK(sb);
2105 	SBLASTMBUFCHK(sb);
2106 
2107 	/*
2108 	 * Remove the delivered data from the socket buffer unless we
2109 	 * were only peeking.
2110 	 */
2111 	if (!(flags & MSG_PEEK)) {
2112 		if (len > 0)
2113 			sbdrop_locked(sb, len);
2114 
2115 		/* Notify protocol that we drained some data. */
2116 		if ((so->so_proto->pr_flags & PR_WANTRCVD) &&
2117 		    (((flags & MSG_WAITALL) && uio->uio_resid > 0) ||
2118 		     !(flags & MSG_SOCALLBCK))) {
2119 			SOCKBUF_UNLOCK(sb);
2120 			VNET_SO_ASSERT(so);
2121 			(*so->so_proto->pr_usrreqs->pru_rcvd)(so, flags);
2122 			SOCKBUF_LOCK(sb);
2123 		}
2124 	}
2125 
2126 	/*
2127 	 * For MSG_WAITALL we may have to loop again and wait for
2128 	 * more data to come in.
2129 	 */
2130 	if ((flags & MSG_WAITALL) && uio->uio_resid > 0)
2131 		goto restart;
2132 out:
2133 	SOCKBUF_LOCK_ASSERT(sb);
2134 	SBLASTRECORDCHK(sb);
2135 	SBLASTMBUFCHK(sb);
2136 	SOCKBUF_UNLOCK(sb);
2137 	sbunlock(sb);
2138 	return (error);
2139 }
2140 
2141 /*
2142  * Optimized version of soreceive() for simple datagram cases from userspace.
2143  * Unlike in the stream case, we're able to drop a datagram if copyout()
2144  * fails, and because we handle datagrams atomically, we don't need to use a
2145  * sleep lock to prevent I/O interlacing.
2146  */
2147 int
2148 soreceive_dgram(struct socket *so, struct sockaddr **psa, struct uio *uio,
2149     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2150 {
2151 	struct mbuf *m, *m2;
2152 	int flags, error;
2153 	ssize_t len;
2154 	struct protosw *pr = so->so_proto;
2155 	struct mbuf *nextrecord;
2156 
2157 	if (psa != NULL)
2158 		*psa = NULL;
2159 	if (controlp != NULL)
2160 		*controlp = NULL;
2161 	if (flagsp != NULL)
2162 		flags = *flagsp &~ MSG_EOR;
2163 	else
2164 		flags = 0;
2165 
2166 	/*
2167 	 * For any complicated cases, fall back to the full
2168 	 * soreceive_generic().
2169 	 */
2170 	if (mp0 != NULL || (flags & MSG_PEEK) || (flags & MSG_OOB))
2171 		return (soreceive_generic(so, psa, uio, mp0, controlp,
2172 		    flagsp));
2173 
2174 	/*
2175 	 * Enforce restrictions on use.
2176 	 */
2177 	KASSERT((pr->pr_flags & PR_WANTRCVD) == 0,
2178 	    ("soreceive_dgram: wantrcvd"));
2179 	KASSERT(pr->pr_flags & PR_ATOMIC, ("soreceive_dgram: !atomic"));
2180 	KASSERT((so->so_rcv.sb_state & SBS_RCVATMARK) == 0,
2181 	    ("soreceive_dgram: SBS_RCVATMARK"));
2182 	KASSERT((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0,
2183 	    ("soreceive_dgram: P_CONNREQUIRED"));
2184 
2185 	/*
2186 	 * Loop blocking while waiting for a datagram.
2187 	 */
2188 	SOCKBUF_LOCK(&so->so_rcv);
2189 	while ((m = so->so_rcv.sb_mb) == NULL) {
2190 		KASSERT(sbavail(&so->so_rcv) == 0,
2191 		    ("soreceive_dgram: sb_mb NULL but sbavail %u",
2192 		    sbavail(&so->so_rcv)));
2193 		if (so->so_error) {
2194 			error = so->so_error;
2195 			so->so_error = 0;
2196 			SOCKBUF_UNLOCK(&so->so_rcv);
2197 			return (error);
2198 		}
2199 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE ||
2200 		    uio->uio_resid == 0) {
2201 			SOCKBUF_UNLOCK(&so->so_rcv);
2202 			return (0);
2203 		}
2204 		if ((so->so_state & SS_NBIO) ||
2205 		    (flags & (MSG_DONTWAIT|MSG_NBIO))) {
2206 			SOCKBUF_UNLOCK(&so->so_rcv);
2207 			return (EWOULDBLOCK);
2208 		}
2209 		SBLASTRECORDCHK(&so->so_rcv);
2210 		SBLASTMBUFCHK(&so->so_rcv);
2211 		error = sbwait(&so->so_rcv);
2212 		if (error) {
2213 			SOCKBUF_UNLOCK(&so->so_rcv);
2214 			return (error);
2215 		}
2216 	}
2217 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2218 
2219 	if (uio->uio_td)
2220 		uio->uio_td->td_ru.ru_msgrcv++;
2221 	SBLASTRECORDCHK(&so->so_rcv);
2222 	SBLASTMBUFCHK(&so->so_rcv);
2223 	nextrecord = m->m_nextpkt;
2224 	if (nextrecord == NULL) {
2225 		KASSERT(so->so_rcv.sb_lastrecord == m,
2226 		    ("soreceive_dgram: lastrecord != m"));
2227 	}
2228 
2229 	KASSERT(so->so_rcv.sb_mb->m_nextpkt == nextrecord,
2230 	    ("soreceive_dgram: m_nextpkt != nextrecord"));
2231 
2232 	/*
2233 	 * Pull 'm' and its chain off the front of the packet queue.
2234 	 */
2235 	so->so_rcv.sb_mb = NULL;
2236 	sockbuf_pushsync(&so->so_rcv, nextrecord);
2237 
2238 	/*
2239 	 * Walk 'm's chain and free that many bytes from the socket buffer.
2240 	 */
2241 	for (m2 = m; m2 != NULL; m2 = m2->m_next)
2242 		sbfree(&so->so_rcv, m2);
2243 
2244 	/*
2245 	 * Do a few last checks before we let go of the lock.
2246 	 */
2247 	SBLASTRECORDCHK(&so->so_rcv);
2248 	SBLASTMBUFCHK(&so->so_rcv);
2249 	SOCKBUF_UNLOCK(&so->so_rcv);
2250 
2251 	if (pr->pr_flags & PR_ADDR) {
2252 		KASSERT(m->m_type == MT_SONAME,
2253 		    ("m->m_type == %d", m->m_type));
2254 		if (psa != NULL)
2255 			*psa = sodupsockaddr(mtod(m, struct sockaddr *),
2256 			    M_NOWAIT);
2257 		m = m_free(m);
2258 	}
2259 	if (m == NULL) {
2260 		/* XXXRW: Can this happen? */
2261 		return (0);
2262 	}
2263 
2264 	/*
2265 	 * Packet to copyout() is now in 'm' and it is disconnected from the
2266 	 * queue.
2267 	 *
2268 	 * Process one or more MT_CONTROL mbufs present before any data mbufs
2269 	 * in the first mbuf chain on the socket buffer.  We call into the
2270 	 * protocol to perform externalization (or freeing if controlp ==
2271 	 * NULL). In some cases there can be only MT_CONTROL mbufs without
2272 	 * MT_DATA mbufs.
2273 	 */
2274 	if (m->m_type == MT_CONTROL) {
2275 		struct mbuf *cm = NULL, *cmn;
2276 		struct mbuf **cme = &cm;
2277 
2278 		do {
2279 			m2 = m->m_next;
2280 			m->m_next = NULL;
2281 			*cme = m;
2282 			cme = &(*cme)->m_next;
2283 			m = m2;
2284 		} while (m != NULL && m->m_type == MT_CONTROL);
2285 		while (cm != NULL) {
2286 			cmn = cm->m_next;
2287 			cm->m_next = NULL;
2288 			if (pr->pr_domain->dom_externalize != NULL) {
2289 				error = (*pr->pr_domain->dom_externalize)
2290 				    (cm, controlp, flags);
2291 			} else if (controlp != NULL)
2292 				*controlp = cm;
2293 			else
2294 				m_freem(cm);
2295 			if (controlp != NULL) {
2296 				while (*controlp != NULL)
2297 					controlp = &(*controlp)->m_next;
2298 			}
2299 			cm = cmn;
2300 		}
2301 	}
2302 	KASSERT(m == NULL || m->m_type == MT_DATA,
2303 	    ("soreceive_dgram: !data"));
2304 	while (m != NULL && uio->uio_resid > 0) {
2305 		len = uio->uio_resid;
2306 		if (len > m->m_len)
2307 			len = m->m_len;
2308 		error = uiomove(mtod(m, char *), (int)len, uio);
2309 		if (error) {
2310 			m_freem(m);
2311 			return (error);
2312 		}
2313 		if (len == m->m_len)
2314 			m = m_free(m);
2315 		else {
2316 			m->m_data += len;
2317 			m->m_len -= len;
2318 		}
2319 	}
2320 	if (m != NULL) {
2321 		flags |= MSG_TRUNC;
2322 		m_freem(m);
2323 	}
2324 	if (flagsp != NULL)
2325 		*flagsp |= flags;
2326 	return (0);
2327 }
2328 
2329 int
2330 soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
2331     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2332 {
2333 	int error;
2334 
2335 	CURVNET_SET(so->so_vnet);
2336 	error = (so->so_proto->pr_usrreqs->pru_soreceive(so, psa, uio, mp0,
2337 	    controlp, flagsp));
2338 	CURVNET_RESTORE();
2339 	return (error);
2340 }
2341 
2342 int
2343 soshutdown(struct socket *so, int how)
2344 {
2345 	struct protosw *pr = so->so_proto;
2346 	int error;
2347 
2348 	if (!(how == SHUT_RD || how == SHUT_WR || how == SHUT_RDWR))
2349 		return (EINVAL);
2350 	if ((so->so_state &
2351 	    (SS_ISCONNECTED | SS_ISCONNECTING | SS_ISDISCONNECTING)) == 0)
2352 		return (ENOTCONN);
2353 
2354 	CURVNET_SET(so->so_vnet);
2355 	if (pr->pr_usrreqs->pru_flush != NULL)
2356 		(*pr->pr_usrreqs->pru_flush)(so, how);
2357 	if (how != SHUT_WR)
2358 		sorflush(so);
2359 	if (how != SHUT_RD) {
2360 		error = (*pr->pr_usrreqs->pru_shutdown)(so);
2361 		wakeup(&so->so_timeo);
2362 		CURVNET_RESTORE();
2363 		return (error);
2364 	}
2365 	wakeup(&so->so_timeo);
2366 	CURVNET_RESTORE();
2367 	return (0);
2368 }
2369 
2370 void
2371 sorflush(struct socket *so)
2372 {
2373 	struct sockbuf *sb = &so->so_rcv;
2374 	struct protosw *pr = so->so_proto;
2375 	struct socket aso;
2376 
2377 	VNET_SO_ASSERT(so);
2378 
2379 	/*
2380 	 * In order to avoid calling dom_dispose with the socket buffer mutex
2381 	 * held, and in order to generally avoid holding the lock for a long
2382 	 * time, we make a copy of the socket buffer and clear the original
2383 	 * (except locks, state).  The new socket buffer copy won't have
2384 	 * initialized locks so we can only call routines that won't use or
2385 	 * assert those locks.
2386 	 *
2387 	 * Dislodge threads currently blocked in receive and wait to acquire
2388 	 * a lock against other simultaneous readers before clearing the
2389 	 * socket buffer.  Don't let our acquire be interrupted by a signal
2390 	 * despite any existing socket disposition on interruptable waiting.
2391 	 */
2392 	socantrcvmore(so);
2393 	(void) sblock(sb, SBL_WAIT | SBL_NOINTR);
2394 
2395 	/*
2396 	 * Invalidate/clear most of the sockbuf structure, but leave selinfo
2397 	 * and mutex data unchanged.
2398 	 */
2399 	SOCKBUF_LOCK(sb);
2400 	bzero(&aso, sizeof(aso));
2401 	aso.so_pcb = so->so_pcb;
2402 	bcopy(&sb->sb_startzero, &aso.so_rcv.sb_startzero,
2403 	    sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
2404 	bzero(&sb->sb_startzero,
2405 	    sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
2406 	SOCKBUF_UNLOCK(sb);
2407 	sbunlock(sb);
2408 
2409 	/*
2410 	 * Dispose of special rights and flush the copied socket.  Don't call
2411 	 * any unsafe routines (that rely on locks being initialized) on aso.
2412 	 */
2413 	if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose != NULL)
2414 		(*pr->pr_domain->dom_dispose)(&aso);
2415 	sbrelease_internal(&aso.so_rcv, so);
2416 }
2417 
2418 /*
2419  * Wrapper for Socket established helper hook.
2420  * Parameters: socket, context of the hook point, hook id.
2421  */
2422 static int inline
2423 hhook_run_socket(struct socket *so, void *hctx, int32_t h_id)
2424 {
2425 	struct socket_hhook_data hhook_data = {
2426 		.so = so,
2427 		.hctx = hctx,
2428 		.m = NULL,
2429 		.status = 0
2430 	};
2431 
2432 	CURVNET_SET(so->so_vnet);
2433 	HHOOKS_RUN_IF(V_socket_hhh[h_id], &hhook_data, &so->osd);
2434 	CURVNET_RESTORE();
2435 
2436 	/* Ugly but needed, since hhooks return void for now */
2437 	return (hhook_data.status);
2438 }
2439 
2440 /*
2441  * Perhaps this routine, and sooptcopyout(), below, ought to come in an
2442  * additional variant to handle the case where the option value needs to be
2443  * some kind of integer, but not a specific size.  In addition to their use
2444  * here, these functions are also called by the protocol-level pr_ctloutput()
2445  * routines.
2446  */
2447 int
2448 sooptcopyin(struct sockopt *sopt, void *buf, size_t len, size_t minlen)
2449 {
2450 	size_t	valsize;
2451 
2452 	/*
2453 	 * If the user gives us more than we wanted, we ignore it, but if we
2454 	 * don't get the minimum length the caller wants, we return EINVAL.
2455 	 * On success, sopt->sopt_valsize is set to however much we actually
2456 	 * retrieved.
2457 	 */
2458 	if ((valsize = sopt->sopt_valsize) < minlen)
2459 		return EINVAL;
2460 	if (valsize > len)
2461 		sopt->sopt_valsize = valsize = len;
2462 
2463 	if (sopt->sopt_td != NULL)
2464 		return (copyin(sopt->sopt_val, buf, valsize));
2465 
2466 	bcopy(sopt->sopt_val, buf, valsize);
2467 	return (0);
2468 }
2469 
2470 /*
2471  * Kernel version of setsockopt(2).
2472  *
2473  * XXX: optlen is size_t, not socklen_t
2474  */
2475 int
2476 so_setsockopt(struct socket *so, int level, int optname, void *optval,
2477     size_t optlen)
2478 {
2479 	struct sockopt sopt;
2480 
2481 	sopt.sopt_level = level;
2482 	sopt.sopt_name = optname;
2483 	sopt.sopt_dir = SOPT_SET;
2484 	sopt.sopt_val = optval;
2485 	sopt.sopt_valsize = optlen;
2486 	sopt.sopt_td = NULL;
2487 	return (sosetopt(so, &sopt));
2488 }
2489 
2490 int
2491 sosetopt(struct socket *so, struct sockopt *sopt)
2492 {
2493 	int	error, optval;
2494 	struct	linger l;
2495 	struct	timeval tv;
2496 	sbintime_t val;
2497 	uint32_t val32;
2498 #ifdef MAC
2499 	struct mac extmac;
2500 #endif
2501 
2502 	CURVNET_SET(so->so_vnet);
2503 	error = 0;
2504 	if (sopt->sopt_level != SOL_SOCKET) {
2505 		if (so->so_proto->pr_ctloutput != NULL) {
2506 			error = (*so->so_proto->pr_ctloutput)(so, sopt);
2507 			CURVNET_RESTORE();
2508 			return (error);
2509 		}
2510 		error = ENOPROTOOPT;
2511 	} else {
2512 		switch (sopt->sopt_name) {
2513 		case SO_ACCEPTFILTER:
2514 			error = do_setopt_accept_filter(so, sopt);
2515 			if (error)
2516 				goto bad;
2517 			break;
2518 
2519 		case SO_LINGER:
2520 			error = sooptcopyin(sopt, &l, sizeof l, sizeof l);
2521 			if (error)
2522 				goto bad;
2523 
2524 			SOCK_LOCK(so);
2525 			so->so_linger = l.l_linger;
2526 			if (l.l_onoff)
2527 				so->so_options |= SO_LINGER;
2528 			else
2529 				so->so_options &= ~SO_LINGER;
2530 			SOCK_UNLOCK(so);
2531 			break;
2532 
2533 		case SO_DEBUG:
2534 		case SO_KEEPALIVE:
2535 		case SO_DONTROUTE:
2536 		case SO_USELOOPBACK:
2537 		case SO_BROADCAST:
2538 		case SO_REUSEADDR:
2539 		case SO_REUSEPORT:
2540 		case SO_OOBINLINE:
2541 		case SO_TIMESTAMP:
2542 		case SO_BINTIME:
2543 		case SO_NOSIGPIPE:
2544 		case SO_NO_DDP:
2545 		case SO_NO_OFFLOAD:
2546 			error = sooptcopyin(sopt, &optval, sizeof optval,
2547 			    sizeof optval);
2548 			if (error)
2549 				goto bad;
2550 			SOCK_LOCK(so);
2551 			if (optval)
2552 				so->so_options |= sopt->sopt_name;
2553 			else
2554 				so->so_options &= ~sopt->sopt_name;
2555 			SOCK_UNLOCK(so);
2556 			break;
2557 
2558 		case SO_SETFIB:
2559 			error = sooptcopyin(sopt, &optval, sizeof optval,
2560 			    sizeof optval);
2561 			if (error)
2562 				goto bad;
2563 
2564 			if (optval < 0 || optval >= rt_numfibs) {
2565 				error = EINVAL;
2566 				goto bad;
2567 			}
2568 			if (((so->so_proto->pr_domain->dom_family == PF_INET) ||
2569 			   (so->so_proto->pr_domain->dom_family == PF_INET6) ||
2570 			   (so->so_proto->pr_domain->dom_family == PF_ROUTE)))
2571 				so->so_fibnum = optval;
2572 			else
2573 				so->so_fibnum = 0;
2574 			break;
2575 
2576 		case SO_USER_COOKIE:
2577 			error = sooptcopyin(sopt, &val32, sizeof val32,
2578 			    sizeof val32);
2579 			if (error)
2580 				goto bad;
2581 			so->so_user_cookie = val32;
2582 			break;
2583 
2584 		case SO_SNDBUF:
2585 		case SO_RCVBUF:
2586 		case SO_SNDLOWAT:
2587 		case SO_RCVLOWAT:
2588 			error = sooptcopyin(sopt, &optval, sizeof optval,
2589 			    sizeof optval);
2590 			if (error)
2591 				goto bad;
2592 
2593 			/*
2594 			 * Values < 1 make no sense for any of these options,
2595 			 * so disallow them.
2596 			 */
2597 			if (optval < 1) {
2598 				error = EINVAL;
2599 				goto bad;
2600 			}
2601 
2602 			switch (sopt->sopt_name) {
2603 			case SO_SNDBUF:
2604 			case SO_RCVBUF:
2605 				if (sbreserve(sopt->sopt_name == SO_SNDBUF ?
2606 				    &so->so_snd : &so->so_rcv, (u_long)optval,
2607 				    so, curthread) == 0) {
2608 					error = ENOBUFS;
2609 					goto bad;
2610 				}
2611 				(sopt->sopt_name == SO_SNDBUF ? &so->so_snd :
2612 				    &so->so_rcv)->sb_flags &= ~SB_AUTOSIZE;
2613 				break;
2614 
2615 			/*
2616 			 * Make sure the low-water is never greater than the
2617 			 * high-water.
2618 			 */
2619 			case SO_SNDLOWAT:
2620 				SOCKBUF_LOCK(&so->so_snd);
2621 				so->so_snd.sb_lowat =
2622 				    (optval > so->so_snd.sb_hiwat) ?
2623 				    so->so_snd.sb_hiwat : optval;
2624 				SOCKBUF_UNLOCK(&so->so_snd);
2625 				break;
2626 			case SO_RCVLOWAT:
2627 				SOCKBUF_LOCK(&so->so_rcv);
2628 				so->so_rcv.sb_lowat =
2629 				    (optval > so->so_rcv.sb_hiwat) ?
2630 				    so->so_rcv.sb_hiwat : optval;
2631 				SOCKBUF_UNLOCK(&so->so_rcv);
2632 				break;
2633 			}
2634 			break;
2635 
2636 		case SO_SNDTIMEO:
2637 		case SO_RCVTIMEO:
2638 #ifdef COMPAT_FREEBSD32
2639 			if (SV_CURPROC_FLAG(SV_ILP32)) {
2640 				struct timeval32 tv32;
2641 
2642 				error = sooptcopyin(sopt, &tv32, sizeof tv32,
2643 				    sizeof tv32);
2644 				CP(tv32, tv, tv_sec);
2645 				CP(tv32, tv, tv_usec);
2646 			} else
2647 #endif
2648 				error = sooptcopyin(sopt, &tv, sizeof tv,
2649 				    sizeof tv);
2650 			if (error)
2651 				goto bad;
2652 			if (tv.tv_sec < 0 || tv.tv_usec < 0 ||
2653 			    tv.tv_usec >= 1000000) {
2654 				error = EDOM;
2655 				goto bad;
2656 			}
2657 			if (tv.tv_sec > INT32_MAX)
2658 				val = SBT_MAX;
2659 			else
2660 				val = tvtosbt(tv);
2661 			switch (sopt->sopt_name) {
2662 			case SO_SNDTIMEO:
2663 				so->so_snd.sb_timeo = val;
2664 				break;
2665 			case SO_RCVTIMEO:
2666 				so->so_rcv.sb_timeo = val;
2667 				break;
2668 			}
2669 			break;
2670 
2671 		case SO_LABEL:
2672 #ifdef MAC
2673 			error = sooptcopyin(sopt, &extmac, sizeof extmac,
2674 			    sizeof extmac);
2675 			if (error)
2676 				goto bad;
2677 			error = mac_setsockopt_label(sopt->sopt_td->td_ucred,
2678 			    so, &extmac);
2679 #else
2680 			error = EOPNOTSUPP;
2681 #endif
2682 			break;
2683 
2684 		default:
2685 			if (V_socket_hhh[HHOOK_SOCKET_OPT]->hhh_nhooks > 0)
2686 				error = hhook_run_socket(so, sopt,
2687 				    HHOOK_SOCKET_OPT);
2688 			else
2689 				error = ENOPROTOOPT;
2690 			break;
2691 		}
2692 		if (error == 0 && so->so_proto->pr_ctloutput != NULL)
2693 			(void)(*so->so_proto->pr_ctloutput)(so, sopt);
2694 	}
2695 bad:
2696 	CURVNET_RESTORE();
2697 	return (error);
2698 }
2699 
2700 /*
2701  * Helper routine for getsockopt.
2702  */
2703 int
2704 sooptcopyout(struct sockopt *sopt, const void *buf, size_t len)
2705 {
2706 	int	error;
2707 	size_t	valsize;
2708 
2709 	error = 0;
2710 
2711 	/*
2712 	 * Documented get behavior is that we always return a value, possibly
2713 	 * truncated to fit in the user's buffer.  Traditional behavior is
2714 	 * that we always tell the user precisely how much we copied, rather
2715 	 * than something useful like the total amount we had available for
2716 	 * her.  Note that this interface is not idempotent; the entire
2717 	 * answer must be generated ahead of time.
2718 	 */
2719 	valsize = min(len, sopt->sopt_valsize);
2720 	sopt->sopt_valsize = valsize;
2721 	if (sopt->sopt_val != NULL) {
2722 		if (sopt->sopt_td != NULL)
2723 			error = copyout(buf, sopt->sopt_val, valsize);
2724 		else
2725 			bcopy(buf, sopt->sopt_val, valsize);
2726 	}
2727 	return (error);
2728 }
2729 
2730 int
2731 sogetopt(struct socket *so, struct sockopt *sopt)
2732 {
2733 	int	error, optval;
2734 	struct	linger l;
2735 	struct	timeval tv;
2736 #ifdef MAC
2737 	struct mac extmac;
2738 #endif
2739 
2740 	CURVNET_SET(so->so_vnet);
2741 	error = 0;
2742 	if (sopt->sopt_level != SOL_SOCKET) {
2743 		if (so->so_proto->pr_ctloutput != NULL)
2744 			error = (*so->so_proto->pr_ctloutput)(so, sopt);
2745 		else
2746 			error = ENOPROTOOPT;
2747 		CURVNET_RESTORE();
2748 		return (error);
2749 	} else {
2750 		switch (sopt->sopt_name) {
2751 		case SO_ACCEPTFILTER:
2752 			error = do_getopt_accept_filter(so, sopt);
2753 			break;
2754 
2755 		case SO_LINGER:
2756 			SOCK_LOCK(so);
2757 			l.l_onoff = so->so_options & SO_LINGER;
2758 			l.l_linger = so->so_linger;
2759 			SOCK_UNLOCK(so);
2760 			error = sooptcopyout(sopt, &l, sizeof l);
2761 			break;
2762 
2763 		case SO_USELOOPBACK:
2764 		case SO_DONTROUTE:
2765 		case SO_DEBUG:
2766 		case SO_KEEPALIVE:
2767 		case SO_REUSEADDR:
2768 		case SO_REUSEPORT:
2769 		case SO_BROADCAST:
2770 		case SO_OOBINLINE:
2771 		case SO_ACCEPTCONN:
2772 		case SO_TIMESTAMP:
2773 		case SO_BINTIME:
2774 		case SO_NOSIGPIPE:
2775 			optval = so->so_options & sopt->sopt_name;
2776 integer:
2777 			error = sooptcopyout(sopt, &optval, sizeof optval);
2778 			break;
2779 
2780 		case SO_TYPE:
2781 			optval = so->so_type;
2782 			goto integer;
2783 
2784 		case SO_PROTOCOL:
2785 			optval = so->so_proto->pr_protocol;
2786 			goto integer;
2787 
2788 		case SO_ERROR:
2789 			SOCK_LOCK(so);
2790 			optval = so->so_error;
2791 			so->so_error = 0;
2792 			SOCK_UNLOCK(so);
2793 			goto integer;
2794 
2795 		case SO_SNDBUF:
2796 			optval = so->so_snd.sb_hiwat;
2797 			goto integer;
2798 
2799 		case SO_RCVBUF:
2800 			optval = so->so_rcv.sb_hiwat;
2801 			goto integer;
2802 
2803 		case SO_SNDLOWAT:
2804 			optval = so->so_snd.sb_lowat;
2805 			goto integer;
2806 
2807 		case SO_RCVLOWAT:
2808 			optval = so->so_rcv.sb_lowat;
2809 			goto integer;
2810 
2811 		case SO_SNDTIMEO:
2812 		case SO_RCVTIMEO:
2813 			tv = sbttotv(sopt->sopt_name == SO_SNDTIMEO ?
2814 			    so->so_snd.sb_timeo : so->so_rcv.sb_timeo);
2815 #ifdef COMPAT_FREEBSD32
2816 			if (SV_CURPROC_FLAG(SV_ILP32)) {
2817 				struct timeval32 tv32;
2818 
2819 				CP(tv, tv32, tv_sec);
2820 				CP(tv, tv32, tv_usec);
2821 				error = sooptcopyout(sopt, &tv32, sizeof tv32);
2822 			} else
2823 #endif
2824 				error = sooptcopyout(sopt, &tv, sizeof tv);
2825 			break;
2826 
2827 		case SO_LABEL:
2828 #ifdef MAC
2829 			error = sooptcopyin(sopt, &extmac, sizeof(extmac),
2830 			    sizeof(extmac));
2831 			if (error)
2832 				goto bad;
2833 			error = mac_getsockopt_label(sopt->sopt_td->td_ucred,
2834 			    so, &extmac);
2835 			if (error)
2836 				goto bad;
2837 			error = sooptcopyout(sopt, &extmac, sizeof extmac);
2838 #else
2839 			error = EOPNOTSUPP;
2840 #endif
2841 			break;
2842 
2843 		case SO_PEERLABEL:
2844 #ifdef MAC
2845 			error = sooptcopyin(sopt, &extmac, sizeof(extmac),
2846 			    sizeof(extmac));
2847 			if (error)
2848 				goto bad;
2849 			error = mac_getsockopt_peerlabel(
2850 			    sopt->sopt_td->td_ucred, so, &extmac);
2851 			if (error)
2852 				goto bad;
2853 			error = sooptcopyout(sopt, &extmac, sizeof extmac);
2854 #else
2855 			error = EOPNOTSUPP;
2856 #endif
2857 			break;
2858 
2859 		case SO_LISTENQLIMIT:
2860 			optval = so->so_qlimit;
2861 			goto integer;
2862 
2863 		case SO_LISTENQLEN:
2864 			optval = so->so_qlen;
2865 			goto integer;
2866 
2867 		case SO_LISTENINCQLEN:
2868 			optval = so->so_incqlen;
2869 			goto integer;
2870 
2871 		default:
2872 			if (V_socket_hhh[HHOOK_SOCKET_OPT]->hhh_nhooks > 0)
2873 				error = hhook_run_socket(so, sopt,
2874 				    HHOOK_SOCKET_OPT);
2875 			else
2876 				error = ENOPROTOOPT;
2877 			break;
2878 		}
2879 	}
2880 #ifdef MAC
2881 bad:
2882 #endif
2883 	CURVNET_RESTORE();
2884 	return (error);
2885 }
2886 
2887 int
2888 soopt_getm(struct sockopt *sopt, struct mbuf **mp)
2889 {
2890 	struct mbuf *m, *m_prev;
2891 	int sopt_size = sopt->sopt_valsize;
2892 
2893 	MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
2894 	if (m == NULL)
2895 		return ENOBUFS;
2896 	if (sopt_size > MLEN) {
2897 		MCLGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT);
2898 		if ((m->m_flags & M_EXT) == 0) {
2899 			m_free(m);
2900 			return ENOBUFS;
2901 		}
2902 		m->m_len = min(MCLBYTES, sopt_size);
2903 	} else {
2904 		m->m_len = min(MLEN, sopt_size);
2905 	}
2906 	sopt_size -= m->m_len;
2907 	*mp = m;
2908 	m_prev = m;
2909 
2910 	while (sopt_size) {
2911 		MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
2912 		if (m == NULL) {
2913 			m_freem(*mp);
2914 			return ENOBUFS;
2915 		}
2916 		if (sopt_size > MLEN) {
2917 			MCLGET(m, sopt->sopt_td != NULL ? M_WAITOK :
2918 			    M_NOWAIT);
2919 			if ((m->m_flags & M_EXT) == 0) {
2920 				m_freem(m);
2921 				m_freem(*mp);
2922 				return ENOBUFS;
2923 			}
2924 			m->m_len = min(MCLBYTES, sopt_size);
2925 		} else {
2926 			m->m_len = min(MLEN, sopt_size);
2927 		}
2928 		sopt_size -= m->m_len;
2929 		m_prev->m_next = m;
2930 		m_prev = m;
2931 	}
2932 	return (0);
2933 }
2934 
2935 int
2936 soopt_mcopyin(struct sockopt *sopt, struct mbuf *m)
2937 {
2938 	struct mbuf *m0 = m;
2939 
2940 	if (sopt->sopt_val == NULL)
2941 		return (0);
2942 	while (m != NULL && sopt->sopt_valsize >= m->m_len) {
2943 		if (sopt->sopt_td != NULL) {
2944 			int error;
2945 
2946 			error = copyin(sopt->sopt_val, mtod(m, char *),
2947 			    m->m_len);
2948 			if (error != 0) {
2949 				m_freem(m0);
2950 				return(error);
2951 			}
2952 		} else
2953 			bcopy(sopt->sopt_val, mtod(m, char *), m->m_len);
2954 		sopt->sopt_valsize -= m->m_len;
2955 		sopt->sopt_val = (char *)sopt->sopt_val + m->m_len;
2956 		m = m->m_next;
2957 	}
2958 	if (m != NULL) /* should be allocated enoughly at ip6_sooptmcopyin() */
2959 		panic("ip6_sooptmcopyin");
2960 	return (0);
2961 }
2962 
2963 int
2964 soopt_mcopyout(struct sockopt *sopt, struct mbuf *m)
2965 {
2966 	struct mbuf *m0 = m;
2967 	size_t valsize = 0;
2968 
2969 	if (sopt->sopt_val == NULL)
2970 		return (0);
2971 	while (m != NULL && sopt->sopt_valsize >= m->m_len) {
2972 		if (sopt->sopt_td != NULL) {
2973 			int error;
2974 
2975 			error = copyout(mtod(m, char *), sopt->sopt_val,
2976 			    m->m_len);
2977 			if (error != 0) {
2978 				m_freem(m0);
2979 				return(error);
2980 			}
2981 		} else
2982 			bcopy(mtod(m, char *), sopt->sopt_val, m->m_len);
2983 		sopt->sopt_valsize -= m->m_len;
2984 		sopt->sopt_val = (char *)sopt->sopt_val + m->m_len;
2985 		valsize += m->m_len;
2986 		m = m->m_next;
2987 	}
2988 	if (m != NULL) {
2989 		/* enough soopt buffer should be given from user-land */
2990 		m_freem(m0);
2991 		return(EINVAL);
2992 	}
2993 	sopt->sopt_valsize = valsize;
2994 	return (0);
2995 }
2996 
2997 /*
2998  * sohasoutofband(): protocol notifies socket layer of the arrival of new
2999  * out-of-band data, which will then notify socket consumers.
3000  */
3001 void
3002 sohasoutofband(struct socket *so)
3003 {
3004 
3005 	if (so->so_sigio != NULL)
3006 		pgsigio(&so->so_sigio, SIGURG, 0);
3007 	selwakeuppri(&so->so_rcv.sb_sel, PSOCK);
3008 }
3009 
3010 int
3011 sopoll(struct socket *so, int events, struct ucred *active_cred,
3012     struct thread *td)
3013 {
3014 
3015 	/*
3016 	 * We do not need to set or assert curvnet as long as everyone uses
3017 	 * sopoll_generic().
3018 	 */
3019 	return (so->so_proto->pr_usrreqs->pru_sopoll(so, events, active_cred,
3020 	    td));
3021 }
3022 
3023 int
3024 sopoll_generic(struct socket *so, int events, struct ucred *active_cred,
3025     struct thread *td)
3026 {
3027 	int revents = 0;
3028 
3029 	SOCKBUF_LOCK(&so->so_snd);
3030 	SOCKBUF_LOCK(&so->so_rcv);
3031 	if (events & (POLLIN | POLLRDNORM))
3032 		if (soreadabledata(so))
3033 			revents |= events & (POLLIN | POLLRDNORM);
3034 
3035 	if (events & (POLLOUT | POLLWRNORM))
3036 		if (sowriteable(so))
3037 			revents |= events & (POLLOUT | POLLWRNORM);
3038 
3039 	if (events & (POLLPRI | POLLRDBAND))
3040 		if (so->so_oobmark || (so->so_rcv.sb_state & SBS_RCVATMARK))
3041 			revents |= events & (POLLPRI | POLLRDBAND);
3042 
3043 	if ((events & POLLINIGNEOF) == 0) {
3044 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
3045 			revents |= events & (POLLIN | POLLRDNORM);
3046 			if (so->so_snd.sb_state & SBS_CANTSENDMORE)
3047 				revents |= POLLHUP;
3048 		}
3049 	}
3050 
3051 	if (revents == 0) {
3052 		if (events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) {
3053 			selrecord(td, &so->so_rcv.sb_sel);
3054 			so->so_rcv.sb_flags |= SB_SEL;
3055 		}
3056 
3057 		if (events & (POLLOUT | POLLWRNORM)) {
3058 			selrecord(td, &so->so_snd.sb_sel);
3059 			so->so_snd.sb_flags |= SB_SEL;
3060 		}
3061 	}
3062 
3063 	SOCKBUF_UNLOCK(&so->so_rcv);
3064 	SOCKBUF_UNLOCK(&so->so_snd);
3065 	return (revents);
3066 }
3067 
3068 int
3069 soo_kqfilter(struct file *fp, struct knote *kn)
3070 {
3071 	struct socket *so = kn->kn_fp->f_data;
3072 	struct sockbuf *sb;
3073 
3074 	switch (kn->kn_filter) {
3075 	case EVFILT_READ:
3076 		if (so->so_options & SO_ACCEPTCONN)
3077 			kn->kn_fop = &solisten_filtops;
3078 		else
3079 			kn->kn_fop = &soread_filtops;
3080 		sb = &so->so_rcv;
3081 		break;
3082 	case EVFILT_WRITE:
3083 		kn->kn_fop = &sowrite_filtops;
3084 		sb = &so->so_snd;
3085 		break;
3086 	default:
3087 		return (EINVAL);
3088 	}
3089 
3090 	SOCKBUF_LOCK(sb);
3091 	knlist_add(&sb->sb_sel.si_note, kn, 1);
3092 	sb->sb_flags |= SB_KNOTE;
3093 	SOCKBUF_UNLOCK(sb);
3094 	return (0);
3095 }
3096 
3097 /*
3098  * Some routines that return EOPNOTSUPP for entry points that are not
3099  * supported by a protocol.  Fill in as needed.
3100  */
3101 int
3102 pru_accept_notsupp(struct socket *so, struct sockaddr **nam)
3103 {
3104 
3105 	return EOPNOTSUPP;
3106 }
3107 
3108 int
3109 pru_aio_queue_notsupp(struct socket *so, struct kaiocb *job)
3110 {
3111 
3112 	return EOPNOTSUPP;
3113 }
3114 
3115 int
3116 pru_attach_notsupp(struct socket *so, int proto, struct thread *td)
3117 {
3118 
3119 	return EOPNOTSUPP;
3120 }
3121 
3122 int
3123 pru_bind_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
3124 {
3125 
3126 	return EOPNOTSUPP;
3127 }
3128 
3129 int
3130 pru_bindat_notsupp(int fd, struct socket *so, struct sockaddr *nam,
3131     struct thread *td)
3132 {
3133 
3134 	return EOPNOTSUPP;
3135 }
3136 
3137 int
3138 pru_connect_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
3139 {
3140 
3141 	return EOPNOTSUPP;
3142 }
3143 
3144 int
3145 pru_connectat_notsupp(int fd, struct socket *so, struct sockaddr *nam,
3146     struct thread *td)
3147 {
3148 
3149 	return EOPNOTSUPP;
3150 }
3151 
3152 int
3153 pru_connect2_notsupp(struct socket *so1, struct socket *so2)
3154 {
3155 
3156 	return EOPNOTSUPP;
3157 }
3158 
3159 int
3160 pru_control_notsupp(struct socket *so, u_long cmd, caddr_t data,
3161     struct ifnet *ifp, struct thread *td)
3162 {
3163 
3164 	return EOPNOTSUPP;
3165 }
3166 
3167 int
3168 pru_disconnect_notsupp(struct socket *so)
3169 {
3170 
3171 	return EOPNOTSUPP;
3172 }
3173 
3174 int
3175 pru_listen_notsupp(struct socket *so, int backlog, struct thread *td)
3176 {
3177 
3178 	return EOPNOTSUPP;
3179 }
3180 
3181 int
3182 pru_peeraddr_notsupp(struct socket *so, struct sockaddr **nam)
3183 {
3184 
3185 	return EOPNOTSUPP;
3186 }
3187 
3188 int
3189 pru_rcvd_notsupp(struct socket *so, int flags)
3190 {
3191 
3192 	return EOPNOTSUPP;
3193 }
3194 
3195 int
3196 pru_rcvoob_notsupp(struct socket *so, struct mbuf *m, int flags)
3197 {
3198 
3199 	return EOPNOTSUPP;
3200 }
3201 
3202 int
3203 pru_send_notsupp(struct socket *so, int flags, struct mbuf *m,
3204     struct sockaddr *addr, struct mbuf *control, struct thread *td)
3205 {
3206 
3207 	return EOPNOTSUPP;
3208 }
3209 
3210 int
3211 pru_ready_notsupp(struct socket *so, struct mbuf *m, int count)
3212 {
3213 
3214 	return (EOPNOTSUPP);
3215 }
3216 
3217 /*
3218  * This isn't really a ``null'' operation, but it's the default one and
3219  * doesn't do anything destructive.
3220  */
3221 int
3222 pru_sense_null(struct socket *so, struct stat *sb)
3223 {
3224 
3225 	sb->st_blksize = so->so_snd.sb_hiwat;
3226 	return 0;
3227 }
3228 
3229 int
3230 pru_shutdown_notsupp(struct socket *so)
3231 {
3232 
3233 	return EOPNOTSUPP;
3234 }
3235 
3236 int
3237 pru_sockaddr_notsupp(struct socket *so, struct sockaddr **nam)
3238 {
3239 
3240 	return EOPNOTSUPP;
3241 }
3242 
3243 int
3244 pru_sosend_notsupp(struct socket *so, struct sockaddr *addr, struct uio *uio,
3245     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
3246 {
3247 
3248 	return EOPNOTSUPP;
3249 }
3250 
3251 int
3252 pru_soreceive_notsupp(struct socket *so, struct sockaddr **paddr,
3253     struct uio *uio, struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
3254 {
3255 
3256 	return EOPNOTSUPP;
3257 }
3258 
3259 int
3260 pru_sopoll_notsupp(struct socket *so, int events, struct ucred *cred,
3261     struct thread *td)
3262 {
3263 
3264 	return EOPNOTSUPP;
3265 }
3266 
3267 static void
3268 filt_sordetach(struct knote *kn)
3269 {
3270 	struct socket *so = kn->kn_fp->f_data;
3271 
3272 	SOCKBUF_LOCK(&so->so_rcv);
3273 	knlist_remove(&so->so_rcv.sb_sel.si_note, kn, 1);
3274 	if (knlist_empty(&so->so_rcv.sb_sel.si_note))
3275 		so->so_rcv.sb_flags &= ~SB_KNOTE;
3276 	SOCKBUF_UNLOCK(&so->so_rcv);
3277 }
3278 
3279 /*ARGSUSED*/
3280 static int
3281 filt_soread(struct knote *kn, long hint)
3282 {
3283 	struct socket *so;
3284 
3285 	so = kn->kn_fp->f_data;
3286 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
3287 
3288 	kn->kn_data = sbavail(&so->so_rcv) - so->so_rcv.sb_ctl;
3289 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
3290 		kn->kn_flags |= EV_EOF;
3291 		kn->kn_fflags = so->so_error;
3292 		return (1);
3293 	} else if (so->so_error)	/* temporary udp error */
3294 		return (1);
3295 
3296 	if (kn->kn_sfflags & NOTE_LOWAT) {
3297 		if (kn->kn_data >= kn->kn_sdata)
3298 			return 1;
3299 	} else {
3300 		if (sbavail(&so->so_rcv) >= so->so_rcv.sb_lowat)
3301 			return 1;
3302 	}
3303 
3304 	/* This hook returning non-zero indicates an event, not error */
3305 	return (hhook_run_socket(so, NULL, HHOOK_FILT_SOREAD));
3306 }
3307 
3308 static void
3309 filt_sowdetach(struct knote *kn)
3310 {
3311 	struct socket *so = kn->kn_fp->f_data;
3312 
3313 	SOCKBUF_LOCK(&so->so_snd);
3314 	knlist_remove(&so->so_snd.sb_sel.si_note, kn, 1);
3315 	if (knlist_empty(&so->so_snd.sb_sel.si_note))
3316 		so->so_snd.sb_flags &= ~SB_KNOTE;
3317 	SOCKBUF_UNLOCK(&so->so_snd);
3318 }
3319 
3320 /*ARGSUSED*/
3321 static int
3322 filt_sowrite(struct knote *kn, long hint)
3323 {
3324 	struct socket *so;
3325 
3326 	so = kn->kn_fp->f_data;
3327 	SOCKBUF_LOCK_ASSERT(&so->so_snd);
3328 	kn->kn_data = sbspace(&so->so_snd);
3329 
3330 	hhook_run_socket(so, kn, HHOOK_FILT_SOWRITE);
3331 
3332 	if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
3333 		kn->kn_flags |= EV_EOF;
3334 		kn->kn_fflags = so->so_error;
3335 		return (1);
3336 	} else if (so->so_error)	/* temporary udp error */
3337 		return (1);
3338 	else if (((so->so_state & SS_ISCONNECTED) == 0) &&
3339 	    (so->so_proto->pr_flags & PR_CONNREQUIRED))
3340 		return (0);
3341 	else if (kn->kn_sfflags & NOTE_LOWAT)
3342 		return (kn->kn_data >= kn->kn_sdata);
3343 	else
3344 		return (kn->kn_data >= so->so_snd.sb_lowat);
3345 }
3346 
3347 /*ARGSUSED*/
3348 static int
3349 filt_solisten(struct knote *kn, long hint)
3350 {
3351 	struct socket *so = kn->kn_fp->f_data;
3352 
3353 	kn->kn_data = so->so_qlen;
3354 	return (!TAILQ_EMPTY(&so->so_comp));
3355 }
3356 
3357 int
3358 socheckuid(struct socket *so, uid_t uid)
3359 {
3360 
3361 	if (so == NULL)
3362 		return (EPERM);
3363 	if (so->so_cred->cr_uid != uid)
3364 		return (EPERM);
3365 	return (0);
3366 }
3367 
3368 /*
3369  * These functions are used by protocols to notify the socket layer (and its
3370  * consumers) of state changes in the sockets driven by protocol-side events.
3371  */
3372 
3373 /*
3374  * Procedures to manipulate state flags of socket and do appropriate wakeups.
3375  *
3376  * Normal sequence from the active (originating) side is that
3377  * soisconnecting() is called during processing of connect() call, resulting
3378  * in an eventual call to soisconnected() if/when the connection is
3379  * established.  When the connection is torn down soisdisconnecting() is
3380  * called during processing of disconnect() call, and soisdisconnected() is
3381  * called when the connection to the peer is totally severed.  The semantics
3382  * of these routines are such that connectionless protocols can call
3383  * soisconnected() and soisdisconnected() only, bypassing the in-progress
3384  * calls when setting up a ``connection'' takes no time.
3385  *
3386  * From the passive side, a socket is created with two queues of sockets:
3387  * so_incomp for connections in progress and so_comp for connections already
3388  * made and awaiting user acceptance.  As a protocol is preparing incoming
3389  * connections, it creates a socket structure queued on so_incomp by calling
3390  * sonewconn().  When the connection is established, soisconnected() is
3391  * called, and transfers the socket structure to so_comp, making it available
3392  * to accept().
3393  *
3394  * If a socket is closed with sockets on either so_incomp or so_comp, these
3395  * sockets are dropped.
3396  *
3397  * If higher-level protocols are implemented in the kernel, the wakeups done
3398  * here will sometimes cause software-interrupt process scheduling.
3399  */
3400 void
3401 soisconnecting(struct socket *so)
3402 {
3403 
3404 	SOCK_LOCK(so);
3405 	so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
3406 	so->so_state |= SS_ISCONNECTING;
3407 	SOCK_UNLOCK(so);
3408 }
3409 
3410 void
3411 soisconnected(struct socket *so)
3412 {
3413 	struct socket *head;
3414 	int ret;
3415 
3416 restart:
3417 	ACCEPT_LOCK();
3418 	SOCK_LOCK(so);
3419 	so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
3420 	so->so_state |= SS_ISCONNECTED;
3421 	head = so->so_head;
3422 	if (head != NULL && (so->so_qstate & SQ_INCOMP)) {
3423 		if ((so->so_options & SO_ACCEPTFILTER) == 0) {
3424 			SOCK_UNLOCK(so);
3425 			TAILQ_REMOVE(&head->so_incomp, so, so_list);
3426 			head->so_incqlen--;
3427 			so->so_qstate &= ~SQ_INCOMP;
3428 			TAILQ_INSERT_TAIL(&head->so_comp, so, so_list);
3429 			head->so_qlen++;
3430 			so->so_qstate |= SQ_COMP;
3431 			ACCEPT_UNLOCK();
3432 			sorwakeup(head);
3433 			wakeup_one(&head->so_timeo);
3434 		} else {
3435 			ACCEPT_UNLOCK();
3436 			soupcall_set(so, SO_RCV,
3437 			    head->so_accf->so_accept_filter->accf_callback,
3438 			    head->so_accf->so_accept_filter_arg);
3439 			so->so_options &= ~SO_ACCEPTFILTER;
3440 			ret = head->so_accf->so_accept_filter->accf_callback(so,
3441 			    head->so_accf->so_accept_filter_arg, M_NOWAIT);
3442 			if (ret == SU_ISCONNECTED)
3443 				soupcall_clear(so, SO_RCV);
3444 			SOCK_UNLOCK(so);
3445 			if (ret == SU_ISCONNECTED)
3446 				goto restart;
3447 		}
3448 		return;
3449 	}
3450 	SOCK_UNLOCK(so);
3451 	ACCEPT_UNLOCK();
3452 	wakeup(&so->so_timeo);
3453 	sorwakeup(so);
3454 	sowwakeup(so);
3455 }
3456 
3457 void
3458 soisdisconnecting(struct socket *so)
3459 {
3460 
3461 	/*
3462 	 * Note: This code assumes that SOCK_LOCK(so) and
3463 	 * SOCKBUF_LOCK(&so->so_rcv) are the same.
3464 	 */
3465 	SOCKBUF_LOCK(&so->so_rcv);
3466 	so->so_state &= ~SS_ISCONNECTING;
3467 	so->so_state |= SS_ISDISCONNECTING;
3468 	socantrcvmore_locked(so);
3469 	SOCKBUF_LOCK(&so->so_snd);
3470 	socantsendmore_locked(so);
3471 	wakeup(&so->so_timeo);
3472 }
3473 
3474 void
3475 soisdisconnected(struct socket *so)
3476 {
3477 
3478 	/*
3479 	 * Note: This code assumes that SOCK_LOCK(so) and
3480 	 * SOCKBUF_LOCK(&so->so_rcv) are the same.
3481 	 */
3482 	SOCKBUF_LOCK(&so->so_rcv);
3483 	so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
3484 	so->so_state |= SS_ISDISCONNECTED;
3485 	socantrcvmore_locked(so);
3486 	SOCKBUF_LOCK(&so->so_snd);
3487 	sbdrop_locked(&so->so_snd, sbused(&so->so_snd));
3488 	socantsendmore_locked(so);
3489 	wakeup(&so->so_timeo);
3490 }
3491 
3492 /*
3493  * Make a copy of a sockaddr in a malloced buffer of type M_SONAME.
3494  */
3495 struct sockaddr *
3496 sodupsockaddr(const struct sockaddr *sa, int mflags)
3497 {
3498 	struct sockaddr *sa2;
3499 
3500 	sa2 = malloc(sa->sa_len, M_SONAME, mflags);
3501 	if (sa2)
3502 		bcopy(sa, sa2, sa->sa_len);
3503 	return sa2;
3504 }
3505 
3506 /*
3507  * Register per-socket buffer upcalls.
3508  */
3509 void
3510 soupcall_set(struct socket *so, int which,
3511     int (*func)(struct socket *, void *, int), void *arg)
3512 {
3513 	struct sockbuf *sb;
3514 
3515 	switch (which) {
3516 	case SO_RCV:
3517 		sb = &so->so_rcv;
3518 		break;
3519 	case SO_SND:
3520 		sb = &so->so_snd;
3521 		break;
3522 	default:
3523 		panic("soupcall_set: bad which");
3524 	}
3525 	SOCKBUF_LOCK_ASSERT(sb);
3526 #if 0
3527 	/* XXX: accf_http actually wants to do this on purpose. */
3528 	KASSERT(sb->sb_upcall == NULL, ("soupcall_set: overwriting upcall"));
3529 #endif
3530 	sb->sb_upcall = func;
3531 	sb->sb_upcallarg = arg;
3532 	sb->sb_flags |= SB_UPCALL;
3533 }
3534 
3535 void
3536 soupcall_clear(struct socket *so, int which)
3537 {
3538 	struct sockbuf *sb;
3539 
3540 	switch (which) {
3541 	case SO_RCV:
3542 		sb = &so->so_rcv;
3543 		break;
3544 	case SO_SND:
3545 		sb = &so->so_snd;
3546 		break;
3547 	default:
3548 		panic("soupcall_clear: bad which");
3549 	}
3550 	SOCKBUF_LOCK_ASSERT(sb);
3551 	KASSERT(sb->sb_upcall != NULL, ("soupcall_clear: no upcall to clear"));
3552 	sb->sb_upcall = NULL;
3553 	sb->sb_upcallarg = NULL;
3554 	sb->sb_flags &= ~SB_UPCALL;
3555 }
3556 
3557 /*
3558  * Create an external-format (``xsocket'') structure using the information in
3559  * the kernel-format socket structure pointed to by so.  This is done to
3560  * reduce the spew of irrelevant information over this interface, to isolate
3561  * user code from changes in the kernel structure, and potentially to provide
3562  * information-hiding if we decide that some of this information should be
3563  * hidden from users.
3564  */
3565 void
3566 sotoxsocket(struct socket *so, struct xsocket *xso)
3567 {
3568 
3569 	xso->xso_len = sizeof *xso;
3570 	xso->xso_so = so;
3571 	xso->so_type = so->so_type;
3572 	xso->so_options = so->so_options;
3573 	xso->so_linger = so->so_linger;
3574 	xso->so_state = so->so_state;
3575 	xso->so_pcb = so->so_pcb;
3576 	xso->xso_protocol = so->so_proto->pr_protocol;
3577 	xso->xso_family = so->so_proto->pr_domain->dom_family;
3578 	xso->so_qlen = so->so_qlen;
3579 	xso->so_incqlen = so->so_incqlen;
3580 	xso->so_qlimit = so->so_qlimit;
3581 	xso->so_timeo = so->so_timeo;
3582 	xso->so_error = so->so_error;
3583 	xso->so_pgid = so->so_sigio ? so->so_sigio->sio_pgid : 0;
3584 	xso->so_oobmark = so->so_oobmark;
3585 	sbtoxsockbuf(&so->so_snd, &xso->so_snd);
3586 	sbtoxsockbuf(&so->so_rcv, &xso->so_rcv);
3587 	xso->so_uid = so->so_cred->cr_uid;
3588 }
3589 
3590 
3591 /*
3592  * Socket accessor functions to provide external consumers with
3593  * a safe interface to socket state
3594  *
3595  */
3596 
3597 void
3598 so_listeners_apply_all(struct socket *so, void (*func)(struct socket *, void *),
3599     void *arg)
3600 {
3601 
3602 	TAILQ_FOREACH(so, &so->so_comp, so_list)
3603 		func(so, arg);
3604 }
3605 
3606 struct sockbuf *
3607 so_sockbuf_rcv(struct socket *so)
3608 {
3609 
3610 	return (&so->so_rcv);
3611 }
3612 
3613 struct sockbuf *
3614 so_sockbuf_snd(struct socket *so)
3615 {
3616 
3617 	return (&so->so_snd);
3618 }
3619 
3620 int
3621 so_state_get(const struct socket *so)
3622 {
3623 
3624 	return (so->so_state);
3625 }
3626 
3627 void
3628 so_state_set(struct socket *so, int val)
3629 {
3630 
3631 	so->so_state = val;
3632 }
3633 
3634 int
3635 so_options_get(const struct socket *so)
3636 {
3637 
3638 	return (so->so_options);
3639 }
3640 
3641 void
3642 so_options_set(struct socket *so, int val)
3643 {
3644 
3645 	so->so_options = val;
3646 }
3647 
3648 int
3649 so_error_get(const struct socket *so)
3650 {
3651 
3652 	return (so->so_error);
3653 }
3654 
3655 void
3656 so_error_set(struct socket *so, int val)
3657 {
3658 
3659 	so->so_error = val;
3660 }
3661 
3662 int
3663 so_linger_get(const struct socket *so)
3664 {
3665 
3666 	return (so->so_linger);
3667 }
3668 
3669 void
3670 so_linger_set(struct socket *so, int val)
3671 {
3672 
3673 	so->so_linger = val;
3674 }
3675 
3676 struct protosw *
3677 so_protosw_get(const struct socket *so)
3678 {
3679 
3680 	return (so->so_proto);
3681 }
3682 
3683 void
3684 so_protosw_set(struct socket *so, struct protosw *val)
3685 {
3686 
3687 	so->so_proto = val;
3688 }
3689 
3690 void
3691 so_sorwakeup(struct socket *so)
3692 {
3693 
3694 	sorwakeup(so);
3695 }
3696 
3697 void
3698 so_sowwakeup(struct socket *so)
3699 {
3700 
3701 	sowwakeup(so);
3702 }
3703 
3704 void
3705 so_sorwakeup_locked(struct socket *so)
3706 {
3707 
3708 	sorwakeup_locked(so);
3709 }
3710 
3711 void
3712 so_sowwakeup_locked(struct socket *so)
3713 {
3714 
3715 	sowwakeup_locked(so);
3716 }
3717 
3718 void
3719 so_lock(struct socket *so)
3720 {
3721 
3722 	SOCK_LOCK(so);
3723 }
3724 
3725 void
3726 so_unlock(struct socket *so)
3727 {
3728 
3729 	SOCK_UNLOCK(so);
3730 }
3731