xref: /freebsd/sys/kern/uipc_socket.c (revision 123af6ec70016f5556da5972d4d63c7d175c06d3)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1988, 1990, 1993
5  *	The Regents of the University of California.
6  * Copyright (c) 2004 The FreeBSD Foundation
7  * Copyright (c) 2004-2008 Robert N. M. Watson
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)uipc_socket.c	8.3 (Berkeley) 4/15/94
35  */
36 
37 /*
38  * Comments on the socket life cycle:
39  *
40  * soalloc() sets of socket layer state for a socket, called only by
41  * socreate() and sonewconn().  Socket layer private.
42  *
43  * sodealloc() tears down socket layer state for a socket, called only by
44  * sofree() and sonewconn().  Socket layer private.
45  *
46  * pru_attach() associates protocol layer state with an allocated socket;
47  * called only once, may fail, aborting socket allocation.  This is called
48  * from socreate() and sonewconn().  Socket layer private.
49  *
50  * pru_detach() disassociates protocol layer state from an attached socket,
51  * and will be called exactly once for sockets in which pru_attach() has
52  * been successfully called.  If pru_attach() returned an error,
53  * pru_detach() will not be called.  Socket layer private.
54  *
55  * pru_abort() and pru_close() notify the protocol layer that the last
56  * consumer of a socket is starting to tear down the socket, and that the
57  * protocol should terminate the connection.  Historically, pru_abort() also
58  * detached protocol state from the socket state, but this is no longer the
59  * case.
60  *
61  * socreate() creates a socket and attaches protocol state.  This is a public
62  * interface that may be used by socket layer consumers to create new
63  * sockets.
64  *
65  * sonewconn() creates a socket and attaches protocol state.  This is a
66  * public interface  that may be used by protocols to create new sockets when
67  * a new connection is received and will be available for accept() on a
68  * listen socket.
69  *
70  * soclose() destroys a socket after possibly waiting for it to disconnect.
71  * This is a public interface that socket consumers should use to close and
72  * release a socket when done with it.
73  *
74  * soabort() destroys a socket without waiting for it to disconnect (used
75  * only for incoming connections that are already partially or fully
76  * connected).  This is used internally by the socket layer when clearing
77  * listen socket queues (due to overflow or close on the listen socket), but
78  * is also a public interface protocols may use to abort connections in
79  * their incomplete listen queues should they no longer be required.  Sockets
80  * placed in completed connection listen queues should not be aborted for
81  * reasons described in the comment above the soclose() implementation.  This
82  * is not a general purpose close routine, and except in the specific
83  * circumstances described here, should not be used.
84  *
85  * sofree() will free a socket and its protocol state if all references on
86  * the socket have been released, and is the public interface to attempt to
87  * free a socket when a reference is removed.  This is a socket layer private
88  * interface.
89  *
90  * NOTE: In addition to socreate() and soclose(), which provide a single
91  * socket reference to the consumer to be managed as required, there are two
92  * calls to explicitly manage socket references, soref(), and sorele().
93  * Currently, these are generally required only when transitioning a socket
94  * from a listen queue to a file descriptor, in order to prevent garbage
95  * collection of the socket at an untimely moment.  For a number of reasons,
96  * these interfaces are not preferred, and should be avoided.
97  *
98  * NOTE: With regard to VNETs the general rule is that callers do not set
99  * curvnet. Exceptions to this rule include soabort(), sodisconnect(),
100  * sofree() (and with that sorele(), sotryfree()), as well as sonewconn()
101  * and sorflush(), which are usually called from a pre-set VNET context.
102  * sopoll() currently does not need a VNET context to be set.
103  */
104 
105 #include <sys/cdefs.h>
106 __FBSDID("$FreeBSD$");
107 
108 #include "opt_inet.h"
109 #include "opt_inet6.h"
110 #include "opt_sctp.h"
111 
112 #include <sys/param.h>
113 #include <sys/systm.h>
114 #include <sys/fcntl.h>
115 #include <sys/limits.h>
116 #include <sys/lock.h>
117 #include <sys/mac.h>
118 #include <sys/malloc.h>
119 #include <sys/mbuf.h>
120 #include <sys/mutex.h>
121 #include <sys/domain.h>
122 #include <sys/file.h>			/* for struct knote */
123 #include <sys/hhook.h>
124 #include <sys/kernel.h>
125 #include <sys/khelp.h>
126 #include <sys/event.h>
127 #include <sys/eventhandler.h>
128 #include <sys/poll.h>
129 #include <sys/proc.h>
130 #include <sys/protosw.h>
131 #include <sys/socket.h>
132 #include <sys/socketvar.h>
133 #include <sys/resourcevar.h>
134 #include <net/route.h>
135 #include <sys/signalvar.h>
136 #include <sys/stat.h>
137 #include <sys/sx.h>
138 #include <sys/sysctl.h>
139 #include <sys/taskqueue.h>
140 #include <sys/uio.h>
141 #include <sys/jail.h>
142 #include <sys/syslog.h>
143 #include <netinet/in.h>
144 
145 #include <net/vnet.h>
146 
147 #include <security/mac/mac_framework.h>
148 
149 #include <vm/uma.h>
150 
151 #ifdef COMPAT_FREEBSD32
152 #include <sys/mount.h>
153 #include <sys/sysent.h>
154 #include <compat/freebsd32/freebsd32.h>
155 #endif
156 
157 static int	soreceive_rcvoob(struct socket *so, struct uio *uio,
158 		    int flags);
159 static void	so_rdknl_lock(void *);
160 static void	so_rdknl_unlock(void *);
161 static void	so_rdknl_assert_locked(void *);
162 static void	so_rdknl_assert_unlocked(void *);
163 static void	so_wrknl_lock(void *);
164 static void	so_wrknl_unlock(void *);
165 static void	so_wrknl_assert_locked(void *);
166 static void	so_wrknl_assert_unlocked(void *);
167 
168 static void	filt_sordetach(struct knote *kn);
169 static int	filt_soread(struct knote *kn, long hint);
170 static void	filt_sowdetach(struct knote *kn);
171 static int	filt_sowrite(struct knote *kn, long hint);
172 static int	filt_soempty(struct knote *kn, long hint);
173 static int inline hhook_run_socket(struct socket *so, void *hctx, int32_t h_id);
174 fo_kqfilter_t	soo_kqfilter;
175 
176 static struct filterops soread_filtops = {
177 	.f_isfd = 1,
178 	.f_detach = filt_sordetach,
179 	.f_event = filt_soread,
180 };
181 static struct filterops sowrite_filtops = {
182 	.f_isfd = 1,
183 	.f_detach = filt_sowdetach,
184 	.f_event = filt_sowrite,
185 };
186 static struct filterops soempty_filtops = {
187 	.f_isfd = 1,
188 	.f_detach = filt_sowdetach,
189 	.f_event = filt_soempty,
190 };
191 
192 so_gen_t	so_gencnt;	/* generation count for sockets */
193 
194 MALLOC_DEFINE(M_SONAME, "soname", "socket name");
195 MALLOC_DEFINE(M_PCB, "pcb", "protocol control block");
196 
197 #define	VNET_SO_ASSERT(so)						\
198 	VNET_ASSERT(curvnet != NULL,					\
199 	    ("%s:%d curvnet is NULL, so=%p", __func__, __LINE__, (so)));
200 
201 VNET_DEFINE(struct hhook_head *, socket_hhh[HHOOK_SOCKET_LAST + 1]);
202 #define	V_socket_hhh		VNET(socket_hhh)
203 
204 /*
205  * Limit on the number of connections in the listen queue waiting
206  * for accept(2).
207  * NB: The original sysctl somaxconn is still available but hidden
208  * to prevent confusion about the actual purpose of this number.
209  */
210 static u_int somaxconn = SOMAXCONN;
211 
212 static int
213 sysctl_somaxconn(SYSCTL_HANDLER_ARGS)
214 {
215 	int error;
216 	int val;
217 
218 	val = somaxconn;
219 	error = sysctl_handle_int(oidp, &val, 0, req);
220 	if (error || !req->newptr )
221 		return (error);
222 
223 	/*
224 	 * The purpose of the UINT_MAX / 3 limit, is so that the formula
225 	 *   3 * so_qlimit / 2
226 	 * below, will not overflow.
227          */
228 
229 	if (val < 1 || val > UINT_MAX / 3)
230 		return (EINVAL);
231 
232 	somaxconn = val;
233 	return (0);
234 }
235 SYSCTL_PROC(_kern_ipc, OID_AUTO, soacceptqueue, CTLTYPE_UINT | CTLFLAG_RW,
236     0, sizeof(int), sysctl_somaxconn, "I",
237     "Maximum listen socket pending connection accept queue size");
238 SYSCTL_PROC(_kern_ipc, KIPC_SOMAXCONN, somaxconn,
239     CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_SKIP,
240     0, sizeof(int), sysctl_somaxconn, "I",
241     "Maximum listen socket pending connection accept queue size (compat)");
242 
243 static int numopensockets;
244 SYSCTL_INT(_kern_ipc, OID_AUTO, numopensockets, CTLFLAG_RD,
245     &numopensockets, 0, "Number of open sockets");
246 
247 /*
248  * accept_mtx locks down per-socket fields relating to accept queues.  See
249  * socketvar.h for an annotation of the protected fields of struct socket.
250  */
251 struct mtx accept_mtx;
252 MTX_SYSINIT(accept_mtx, &accept_mtx, "accept", MTX_DEF);
253 
254 /*
255  * so_global_mtx protects so_gencnt, numopensockets, and the per-socket
256  * so_gencnt field.
257  */
258 static struct mtx so_global_mtx;
259 MTX_SYSINIT(so_global_mtx, &so_global_mtx, "so_glabel", MTX_DEF);
260 
261 /*
262  * General IPC sysctl name space, used by sockets and a variety of other IPC
263  * types.
264  */
265 SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW, 0, "IPC");
266 
267 /*
268  * Initialize the socket subsystem and set up the socket
269  * memory allocator.
270  */
271 static uma_zone_t socket_zone;
272 int	maxsockets;
273 
274 static void
275 socket_zone_change(void *tag)
276 {
277 
278 	maxsockets = uma_zone_set_max(socket_zone, maxsockets);
279 }
280 
281 static void
282 socket_hhook_register(int subtype)
283 {
284 
285 	if (hhook_head_register(HHOOK_TYPE_SOCKET, subtype,
286 	    &V_socket_hhh[subtype],
287 	    HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
288 		printf("%s: WARNING: unable to register hook\n", __func__);
289 }
290 
291 static void
292 socket_hhook_deregister(int subtype)
293 {
294 
295 	if (hhook_head_deregister(V_socket_hhh[subtype]) != 0)
296 		printf("%s: WARNING: unable to deregister hook\n", __func__);
297 }
298 
299 static void
300 socket_init(void *tag)
301 {
302 
303 	socket_zone = uma_zcreate("socket", sizeof(struct socket), NULL, NULL,
304 	    NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
305 	maxsockets = uma_zone_set_max(socket_zone, maxsockets);
306 	uma_zone_set_warning(socket_zone, "kern.ipc.maxsockets limit reached");
307 	EVENTHANDLER_REGISTER(maxsockets_change, socket_zone_change, NULL,
308 	    EVENTHANDLER_PRI_FIRST);
309 }
310 SYSINIT(socket, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY, socket_init, NULL);
311 
312 static void
313 socket_vnet_init(const void *unused __unused)
314 {
315 	int i;
316 
317 	/* We expect a contiguous range */
318 	for (i = 0; i <= HHOOK_SOCKET_LAST; i++)
319 		socket_hhook_register(i);
320 }
321 VNET_SYSINIT(socket_vnet_init, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY,
322     socket_vnet_init, NULL);
323 
324 static void
325 socket_vnet_uninit(const void *unused __unused)
326 {
327 	int i;
328 
329 	for (i = 0; i <= HHOOK_SOCKET_LAST; i++)
330 		socket_hhook_deregister(i);
331 }
332 VNET_SYSUNINIT(socket_vnet_uninit, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY,
333     socket_vnet_uninit, NULL);
334 
335 /*
336  * Initialise maxsockets.  This SYSINIT must be run after
337  * tunable_mbinit().
338  */
339 static void
340 init_maxsockets(void *ignored)
341 {
342 
343 	TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets);
344 	maxsockets = imax(maxsockets, maxfiles);
345 }
346 SYSINIT(param, SI_SUB_TUNABLES, SI_ORDER_ANY, init_maxsockets, NULL);
347 
348 /*
349  * Sysctl to get and set the maximum global sockets limit.  Notify protocols
350  * of the change so that they can update their dependent limits as required.
351  */
352 static int
353 sysctl_maxsockets(SYSCTL_HANDLER_ARGS)
354 {
355 	int error, newmaxsockets;
356 
357 	newmaxsockets = maxsockets;
358 	error = sysctl_handle_int(oidp, &newmaxsockets, 0, req);
359 	if (error == 0 && req->newptr) {
360 		if (newmaxsockets > maxsockets &&
361 		    newmaxsockets <= maxfiles) {
362 			maxsockets = newmaxsockets;
363 			EVENTHANDLER_INVOKE(maxsockets_change);
364 		} else
365 			error = EINVAL;
366 	}
367 	return (error);
368 }
369 SYSCTL_PROC(_kern_ipc, OID_AUTO, maxsockets, CTLTYPE_INT|CTLFLAG_RW,
370     &maxsockets, 0, sysctl_maxsockets, "IU",
371     "Maximum number of sockets available");
372 
373 /*
374  * Socket operation routines.  These routines are called by the routines in
375  * sys_socket.c or from a system process, and implement the semantics of
376  * socket operations by switching out to the protocol specific routines.
377  */
378 
379 /*
380  * Get a socket structure from our zone, and initialize it.  Note that it
381  * would probably be better to allocate socket and PCB at the same time, but
382  * I'm not convinced that all the protocols can be easily modified to do
383  * this.
384  *
385  * soalloc() returns a socket with a ref count of 0.
386  */
387 static struct socket *
388 soalloc(struct vnet *vnet)
389 {
390 	struct socket *so;
391 
392 	so = uma_zalloc(socket_zone, M_NOWAIT | M_ZERO);
393 	if (so == NULL)
394 		return (NULL);
395 #ifdef MAC
396 	if (mac_socket_init(so, M_NOWAIT) != 0) {
397 		uma_zfree(socket_zone, so);
398 		return (NULL);
399 	}
400 #endif
401 	if (khelp_init_osd(HELPER_CLASS_SOCKET, &so->osd)) {
402 		uma_zfree(socket_zone, so);
403 		return (NULL);
404 	}
405 
406 	/*
407 	 * The socket locking protocol allows to lock 2 sockets at a time,
408 	 * however, the first one must be a listening socket.  WITNESS lacks
409 	 * a feature to change class of an existing lock, so we use DUPOK.
410 	 */
411 	mtx_init(&so->so_lock, "socket", NULL, MTX_DEF | MTX_DUPOK);
412 	SOCKBUF_LOCK_INIT(&so->so_snd, "so_snd");
413 	SOCKBUF_LOCK_INIT(&so->so_rcv, "so_rcv");
414 	so->so_rcv.sb_sel = &so->so_rdsel;
415 	so->so_snd.sb_sel = &so->so_wrsel;
416 	sx_init(&so->so_snd.sb_sx, "so_snd_sx");
417 	sx_init(&so->so_rcv.sb_sx, "so_rcv_sx");
418 	TAILQ_INIT(&so->so_snd.sb_aiojobq);
419 	TAILQ_INIT(&so->so_rcv.sb_aiojobq);
420 	TASK_INIT(&so->so_snd.sb_aiotask, 0, soaio_snd, so);
421 	TASK_INIT(&so->so_rcv.sb_aiotask, 0, soaio_rcv, so);
422 #ifdef VIMAGE
423 	VNET_ASSERT(vnet != NULL, ("%s:%d vnet is NULL, so=%p",
424 	    __func__, __LINE__, so));
425 	so->so_vnet = vnet;
426 #endif
427 	/* We shouldn't need the so_global_mtx */
428 	if (hhook_run_socket(so, NULL, HHOOK_SOCKET_CREATE)) {
429 		/* Do we need more comprehensive error returns? */
430 		uma_zfree(socket_zone, so);
431 		return (NULL);
432 	}
433 	mtx_lock(&so_global_mtx);
434 	so->so_gencnt = ++so_gencnt;
435 	++numopensockets;
436 #ifdef VIMAGE
437 	vnet->vnet_sockcnt++;
438 #endif
439 	mtx_unlock(&so_global_mtx);
440 
441 	return (so);
442 }
443 
444 /*
445  * Free the storage associated with a socket at the socket layer, tear down
446  * locks, labels, etc.  All protocol state is assumed already to have been
447  * torn down (and possibly never set up) by the caller.
448  */
449 static void
450 sodealloc(struct socket *so)
451 {
452 
453 	KASSERT(so->so_count == 0, ("sodealloc(): so_count %d", so->so_count));
454 	KASSERT(so->so_pcb == NULL, ("sodealloc(): so_pcb != NULL"));
455 
456 	mtx_lock(&so_global_mtx);
457 	so->so_gencnt = ++so_gencnt;
458 	--numopensockets;	/* Could be below, but faster here. */
459 #ifdef VIMAGE
460 	VNET_ASSERT(so->so_vnet != NULL, ("%s:%d so_vnet is NULL, so=%p",
461 	    __func__, __LINE__, so));
462 	so->so_vnet->vnet_sockcnt--;
463 #endif
464 	mtx_unlock(&so_global_mtx);
465 #ifdef MAC
466 	mac_socket_destroy(so);
467 #endif
468 	hhook_run_socket(so, NULL, HHOOK_SOCKET_CLOSE);
469 
470 	crfree(so->so_cred);
471 	khelp_destroy_osd(&so->osd);
472 	if (SOLISTENING(so)) {
473 		if (so->sol_accept_filter != NULL)
474 			accept_filt_setopt(so, NULL);
475 	} else {
476 		if (so->so_rcv.sb_hiwat)
477 			(void)chgsbsize(so->so_cred->cr_uidinfo,
478 			    &so->so_rcv.sb_hiwat, 0, RLIM_INFINITY);
479 		if (so->so_snd.sb_hiwat)
480 			(void)chgsbsize(so->so_cred->cr_uidinfo,
481 			    &so->so_snd.sb_hiwat, 0, RLIM_INFINITY);
482 		sx_destroy(&so->so_snd.sb_sx);
483 		sx_destroy(&so->so_rcv.sb_sx);
484 		SOCKBUF_LOCK_DESTROY(&so->so_snd);
485 		SOCKBUF_LOCK_DESTROY(&so->so_rcv);
486 	}
487 	mtx_destroy(&so->so_lock);
488 	uma_zfree(socket_zone, so);
489 }
490 
491 /*
492  * socreate returns a socket with a ref count of 1.  The socket should be
493  * closed with soclose().
494  */
495 int
496 socreate(int dom, struct socket **aso, int type, int proto,
497     struct ucred *cred, struct thread *td)
498 {
499 	struct protosw *prp;
500 	struct socket *so;
501 	int error;
502 
503 	if (proto)
504 		prp = pffindproto(dom, proto, type);
505 	else
506 		prp = pffindtype(dom, type);
507 
508 	if (prp == NULL) {
509 		/* No support for domain. */
510 		if (pffinddomain(dom) == NULL)
511 			return (EAFNOSUPPORT);
512 		/* No support for socket type. */
513 		if (proto == 0 && type != 0)
514 			return (EPROTOTYPE);
515 		return (EPROTONOSUPPORT);
516 	}
517 	if (prp->pr_usrreqs->pru_attach == NULL ||
518 	    prp->pr_usrreqs->pru_attach == pru_attach_notsupp)
519 		return (EPROTONOSUPPORT);
520 
521 	if (prison_check_af(cred, prp->pr_domain->dom_family) != 0)
522 		return (EPROTONOSUPPORT);
523 
524 	if (prp->pr_type != type)
525 		return (EPROTOTYPE);
526 	so = soalloc(CRED_TO_VNET(cred));
527 	if (so == NULL)
528 		return (ENOBUFS);
529 
530 	so->so_type = type;
531 	so->so_cred = crhold(cred);
532 	if ((prp->pr_domain->dom_family == PF_INET) ||
533 	    (prp->pr_domain->dom_family == PF_INET6) ||
534 	    (prp->pr_domain->dom_family == PF_ROUTE))
535 		so->so_fibnum = td->td_proc->p_fibnum;
536 	else
537 		so->so_fibnum = 0;
538 	so->so_proto = prp;
539 #ifdef MAC
540 	mac_socket_create(cred, so);
541 #endif
542 	knlist_init(&so->so_rdsel.si_note, so, so_rdknl_lock, so_rdknl_unlock,
543 	    so_rdknl_assert_locked, so_rdknl_assert_unlocked);
544 	knlist_init(&so->so_wrsel.si_note, so, so_wrknl_lock, so_wrknl_unlock,
545 	    so_wrknl_assert_locked, so_wrknl_assert_unlocked);
546 	/*
547 	 * Auto-sizing of socket buffers is managed by the protocols and
548 	 * the appropriate flags must be set in the pru_attach function.
549 	 */
550 	CURVNET_SET(so->so_vnet);
551 	error = (*prp->pr_usrreqs->pru_attach)(so, proto, td);
552 	CURVNET_RESTORE();
553 	if (error) {
554 		sodealloc(so);
555 		return (error);
556 	}
557 	soref(so);
558 	*aso = so;
559 	return (0);
560 }
561 
562 #ifdef REGRESSION
563 static int regression_sonewconn_earlytest = 1;
564 SYSCTL_INT(_regression, OID_AUTO, sonewconn_earlytest, CTLFLAG_RW,
565     &regression_sonewconn_earlytest, 0, "Perform early sonewconn limit test");
566 #endif
567 
568 /*
569  * When an attempt at a new connection is noted on a socket which accepts
570  * connections, sonewconn is called.  If the connection is possible (subject
571  * to space constraints, etc.) then we allocate a new structure, properly
572  * linked into the data structure of the original socket, and return this.
573  * Connstatus may be 0, or SS_ISCONFIRMING, or SS_ISCONNECTED.
574  *
575  * Note: the ref count on the socket is 0 on return.
576  */
577 struct socket *
578 sonewconn(struct socket *head, int connstatus)
579 {
580 	static struct timeval lastover;
581 	static struct timeval overinterval = { 60, 0 };
582 	static int overcount;
583 
584 	struct socket *so;
585 	u_int over;
586 
587 	SOLISTEN_LOCK(head);
588 	over = (head->sol_qlen > 3 * head->sol_qlimit / 2);
589 	SOLISTEN_UNLOCK(head);
590 #ifdef REGRESSION
591 	if (regression_sonewconn_earlytest && over) {
592 #else
593 	if (over) {
594 #endif
595 		overcount++;
596 
597 		if (ratecheck(&lastover, &overinterval)) {
598 			log(LOG_DEBUG, "%s: pcb %p: Listen queue overflow: "
599 			    "%i already in queue awaiting acceptance "
600 			    "(%d occurrences)\n",
601 			    __func__, head->so_pcb, head->sol_qlen, overcount);
602 
603 			overcount = 0;
604 		}
605 
606 		return (NULL);
607 	}
608 	VNET_ASSERT(head->so_vnet != NULL, ("%s: so %p vnet is NULL",
609 	    __func__, head));
610 	so = soalloc(head->so_vnet);
611 	if (so == NULL) {
612 		log(LOG_DEBUG, "%s: pcb %p: New socket allocation failure: "
613 		    "limit reached or out of memory\n",
614 		    __func__, head->so_pcb);
615 		return (NULL);
616 	}
617 	so->so_listen = head;
618 	so->so_type = head->so_type;
619 	so->so_linger = head->so_linger;
620 	so->so_state = head->so_state | SS_NOFDREF;
621 	so->so_fibnum = head->so_fibnum;
622 	so->so_proto = head->so_proto;
623 	so->so_cred = crhold(head->so_cred);
624 #ifdef MAC
625 	mac_socket_newconn(head, so);
626 #endif
627 	knlist_init(&so->so_rdsel.si_note, so, so_rdknl_lock, so_rdknl_unlock,
628 	    so_rdknl_assert_locked, so_rdknl_assert_unlocked);
629 	knlist_init(&so->so_wrsel.si_note, so, so_wrknl_lock, so_wrknl_unlock,
630 	    so_wrknl_assert_locked, so_wrknl_assert_unlocked);
631 	VNET_SO_ASSERT(head);
632 	if (soreserve(so, head->sol_sbsnd_hiwat, head->sol_sbrcv_hiwat)) {
633 		sodealloc(so);
634 		log(LOG_DEBUG, "%s: pcb %p: soreserve() failed\n",
635 		    __func__, head->so_pcb);
636 		return (NULL);
637 	}
638 	if ((*so->so_proto->pr_usrreqs->pru_attach)(so, 0, NULL)) {
639 		sodealloc(so);
640 		log(LOG_DEBUG, "%s: pcb %p: pru_attach() failed\n",
641 		    __func__, head->so_pcb);
642 		return (NULL);
643 	}
644 	so->so_rcv.sb_lowat = head->sol_sbrcv_lowat;
645 	so->so_snd.sb_lowat = head->sol_sbsnd_lowat;
646 	so->so_rcv.sb_timeo = head->sol_sbrcv_timeo;
647 	so->so_snd.sb_timeo = head->sol_sbsnd_timeo;
648 	so->so_rcv.sb_flags |= head->sol_sbrcv_flags & SB_AUTOSIZE;
649 	so->so_snd.sb_flags |= head->sol_sbsnd_flags & SB_AUTOSIZE;
650 
651 	SOLISTEN_LOCK(head);
652 	if (head->sol_accept_filter != NULL)
653 		connstatus = 0;
654 	so->so_state |= connstatus;
655 	so->so_options = head->so_options & ~SO_ACCEPTCONN;
656 	soref(head); /* A socket on (in)complete queue refs head. */
657 	if (connstatus) {
658 		TAILQ_INSERT_TAIL(&head->sol_comp, so, so_list);
659 		so->so_qstate = SQ_COMP;
660 		head->sol_qlen++;
661 		solisten_wakeup(head);	/* unlocks */
662 	} else {
663 		/*
664 		 * Keep removing sockets from the head until there's room for
665 		 * us to insert on the tail.  In pre-locking revisions, this
666 		 * was a simple if(), but as we could be racing with other
667 		 * threads and soabort() requires dropping locks, we must
668 		 * loop waiting for the condition to be true.
669 		 */
670 		while (head->sol_incqlen > head->sol_qlimit) {
671 			struct socket *sp;
672 
673 			sp = TAILQ_FIRST(&head->sol_incomp);
674 			TAILQ_REMOVE(&head->sol_incomp, sp, so_list);
675 			head->sol_incqlen--;
676 			SOCK_LOCK(sp);
677 			sp->so_qstate = SQ_NONE;
678 			sp->so_listen = NULL;
679 			SOCK_UNLOCK(sp);
680 			sorele(head);	/* does SOLISTEN_UNLOCK, head stays */
681 			soabort(sp);
682 			SOLISTEN_LOCK(head);
683 		}
684 		TAILQ_INSERT_TAIL(&head->sol_incomp, so, so_list);
685 		so->so_qstate = SQ_INCOMP;
686 		head->sol_incqlen++;
687 		SOLISTEN_UNLOCK(head);
688 	}
689 	return (so);
690 }
691 
692 #ifdef SCTP
693 /*
694  * Socket part of sctp_peeloff().  Detach a new socket from an
695  * association.  The new socket is returned with a reference.
696  */
697 struct socket *
698 sopeeloff(struct socket *head)
699 {
700 	struct socket *so;
701 
702 	VNET_ASSERT(head->so_vnet != NULL, ("%s:%d so_vnet is NULL, head=%p",
703 	    __func__, __LINE__, head));
704 	so = soalloc(head->so_vnet);
705 	if (so == NULL) {
706 		log(LOG_DEBUG, "%s: pcb %p: New socket allocation failure: "
707 		    "limit reached or out of memory\n",
708 		    __func__, head->so_pcb);
709 		return (NULL);
710 	}
711 	so->so_type = head->so_type;
712 	so->so_options = head->so_options;
713 	so->so_linger = head->so_linger;
714 	so->so_state = (head->so_state & SS_NBIO) | SS_ISCONNECTED;
715 	so->so_fibnum = head->so_fibnum;
716 	so->so_proto = head->so_proto;
717 	so->so_cred = crhold(head->so_cred);
718 #ifdef MAC
719 	mac_socket_newconn(head, so);
720 #endif
721 	knlist_init(&so->so_rdsel.si_note, so, so_rdknl_lock, so_rdknl_unlock,
722 	    so_rdknl_assert_locked, so_rdknl_assert_unlocked);
723 	knlist_init(&so->so_wrsel.si_note, so, so_wrknl_lock, so_wrknl_unlock,
724 	    so_wrknl_assert_locked, so_wrknl_assert_unlocked);
725 	VNET_SO_ASSERT(head);
726 	if (soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat)) {
727 		sodealloc(so);
728 		log(LOG_DEBUG, "%s: pcb %p: soreserve() failed\n",
729 		    __func__, head->so_pcb);
730 		return (NULL);
731 	}
732 	if ((*so->so_proto->pr_usrreqs->pru_attach)(so, 0, NULL)) {
733 		sodealloc(so);
734 		log(LOG_DEBUG, "%s: pcb %p: pru_attach() failed\n",
735 		    __func__, head->so_pcb);
736 		return (NULL);
737 	}
738 	so->so_rcv.sb_lowat = head->so_rcv.sb_lowat;
739 	so->so_snd.sb_lowat = head->so_snd.sb_lowat;
740 	so->so_rcv.sb_timeo = head->so_rcv.sb_timeo;
741 	so->so_snd.sb_timeo = head->so_snd.sb_timeo;
742 	so->so_rcv.sb_flags |= head->so_rcv.sb_flags & SB_AUTOSIZE;
743 	so->so_snd.sb_flags |= head->so_snd.sb_flags & SB_AUTOSIZE;
744 
745 	soref(so);
746 
747 	return (so);
748 }
749 #endif	/* SCTP */
750 
751 int
752 sobind(struct socket *so, struct sockaddr *nam, struct thread *td)
753 {
754 	int error;
755 
756 	CURVNET_SET(so->so_vnet);
757 	error = (*so->so_proto->pr_usrreqs->pru_bind)(so, nam, td);
758 	CURVNET_RESTORE();
759 	return (error);
760 }
761 
762 int
763 sobindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
764 {
765 	int error;
766 
767 	CURVNET_SET(so->so_vnet);
768 	error = (*so->so_proto->pr_usrreqs->pru_bindat)(fd, so, nam, td);
769 	CURVNET_RESTORE();
770 	return (error);
771 }
772 
773 /*
774  * solisten() transitions a socket from a non-listening state to a listening
775  * state, but can also be used to update the listen queue depth on an
776  * existing listen socket.  The protocol will call back into the sockets
777  * layer using solisten_proto_check() and solisten_proto() to check and set
778  * socket-layer listen state.  Call backs are used so that the protocol can
779  * acquire both protocol and socket layer locks in whatever order is required
780  * by the protocol.
781  *
782  * Protocol implementors are advised to hold the socket lock across the
783  * socket-layer test and set to avoid races at the socket layer.
784  */
785 int
786 solisten(struct socket *so, int backlog, struct thread *td)
787 {
788 	int error;
789 
790 	CURVNET_SET(so->so_vnet);
791 	error = (*so->so_proto->pr_usrreqs->pru_listen)(so, backlog, td);
792 	CURVNET_RESTORE();
793 	return (error);
794 }
795 
796 int
797 solisten_proto_check(struct socket *so)
798 {
799 
800 	SOCK_LOCK_ASSERT(so);
801 
802 	if (so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING |
803 	    SS_ISDISCONNECTING))
804 		return (EINVAL);
805 	return (0);
806 }
807 
808 void
809 solisten_proto(struct socket *so, int backlog)
810 {
811 	int sbrcv_lowat, sbsnd_lowat;
812 	u_int sbrcv_hiwat, sbsnd_hiwat;
813 	short sbrcv_flags, sbsnd_flags;
814 	sbintime_t sbrcv_timeo, sbsnd_timeo;
815 
816 	SOCK_LOCK_ASSERT(so);
817 
818 	if (SOLISTENING(so))
819 		goto listening;
820 
821 	/*
822 	 * Change this socket to listening state.
823 	 */
824 	sbrcv_lowat = so->so_rcv.sb_lowat;
825 	sbsnd_lowat = so->so_snd.sb_lowat;
826 	sbrcv_hiwat = so->so_rcv.sb_hiwat;
827 	sbsnd_hiwat = so->so_snd.sb_hiwat;
828 	sbrcv_flags = so->so_rcv.sb_flags;
829 	sbsnd_flags = so->so_snd.sb_flags;
830 	sbrcv_timeo = so->so_rcv.sb_timeo;
831 	sbsnd_timeo = so->so_snd.sb_timeo;
832 
833 	sbdestroy(&so->so_snd, so);
834 	sbdestroy(&so->so_rcv, so);
835 	sx_destroy(&so->so_snd.sb_sx);
836 	sx_destroy(&so->so_rcv.sb_sx);
837 	SOCKBUF_LOCK_DESTROY(&so->so_snd);
838 	SOCKBUF_LOCK_DESTROY(&so->so_rcv);
839 
840 #ifdef INVARIANTS
841 	bzero(&so->so_rcv,
842 	    sizeof(struct socket) - offsetof(struct socket, so_rcv));
843 #endif
844 
845 	so->sol_sbrcv_lowat = sbrcv_lowat;
846 	so->sol_sbsnd_lowat = sbsnd_lowat;
847 	so->sol_sbrcv_hiwat = sbrcv_hiwat;
848 	so->sol_sbsnd_hiwat = sbsnd_hiwat;
849 	so->sol_sbrcv_flags = sbrcv_flags;
850 	so->sol_sbsnd_flags = sbsnd_flags;
851 	so->sol_sbrcv_timeo = sbrcv_timeo;
852 	so->sol_sbsnd_timeo = sbsnd_timeo;
853 
854 	so->sol_qlen = so->sol_incqlen = 0;
855 	TAILQ_INIT(&so->sol_incomp);
856 	TAILQ_INIT(&so->sol_comp);
857 
858 	so->sol_accept_filter = NULL;
859 	so->sol_accept_filter_arg = NULL;
860 	so->sol_accept_filter_str = NULL;
861 
862 	so->sol_upcall = NULL;
863 	so->sol_upcallarg = NULL;
864 
865 	so->so_options |= SO_ACCEPTCONN;
866 
867 listening:
868 	if (backlog < 0 || backlog > somaxconn)
869 		backlog = somaxconn;
870 	so->sol_qlimit = backlog;
871 }
872 
873 /*
874  * Wakeup listeners/subsystems once we have a complete connection.
875  * Enters with lock, returns unlocked.
876  */
877 void
878 solisten_wakeup(struct socket *sol)
879 {
880 
881 	if (sol->sol_upcall != NULL)
882 		(void )sol->sol_upcall(sol, sol->sol_upcallarg, M_NOWAIT);
883 	else {
884 		selwakeuppri(&sol->so_rdsel, PSOCK);
885 		KNOTE_LOCKED(&sol->so_rdsel.si_note, 0);
886 	}
887 	SOLISTEN_UNLOCK(sol);
888 	wakeup_one(&sol->sol_comp);
889 	if ((sol->so_state & SS_ASYNC) && sol->so_sigio != NULL)
890 		pgsigio(&sol->so_sigio, SIGIO, 0);
891 }
892 
893 /*
894  * Return single connection off a listening socket queue.  Main consumer of
895  * the function is kern_accept4().  Some modules, that do their own accept
896  * management also use the function.
897  *
898  * Listening socket must be locked on entry and is returned unlocked on
899  * return.
900  * The flags argument is set of accept4(2) flags and ACCEPT4_INHERIT.
901  */
902 int
903 solisten_dequeue(struct socket *head, struct socket **ret, int flags)
904 {
905 	struct socket *so;
906 	int error;
907 
908 	SOLISTEN_LOCK_ASSERT(head);
909 
910 	while (!(head->so_state & SS_NBIO) && TAILQ_EMPTY(&head->sol_comp) &&
911 	    head->so_error == 0) {
912 		error = msleep(&head->sol_comp, &head->so_lock, PSOCK | PCATCH,
913 		    "accept", 0);
914 		if (error != 0) {
915 			SOLISTEN_UNLOCK(head);
916 			return (error);
917 		}
918 	}
919 	if (head->so_error) {
920 		error = head->so_error;
921 		head->so_error = 0;
922 	} else if ((head->so_state & SS_NBIO) && TAILQ_EMPTY(&head->sol_comp))
923 		error = EWOULDBLOCK;
924 	else
925 		error = 0;
926 	if (error) {
927 		SOLISTEN_UNLOCK(head);
928 		return (error);
929 	}
930 	so = TAILQ_FIRST(&head->sol_comp);
931 	SOCK_LOCK(so);
932 	KASSERT(so->so_qstate == SQ_COMP,
933 	    ("%s: so %p not SQ_COMP", __func__, so));
934 	soref(so);
935 	head->sol_qlen--;
936 	so->so_qstate = SQ_NONE;
937 	so->so_listen = NULL;
938 	TAILQ_REMOVE(&head->sol_comp, so, so_list);
939 	if (flags & ACCEPT4_INHERIT)
940 		so->so_state |= (head->so_state & SS_NBIO);
941 	else
942 		so->so_state |= (flags & SOCK_NONBLOCK) ? SS_NBIO : 0;
943 	SOCK_UNLOCK(so);
944 	sorele(head);
945 
946 	*ret = so;
947 	return (0);
948 }
949 
950 /*
951  * Evaluate the reference count and named references on a socket; if no
952  * references remain, free it.  This should be called whenever a reference is
953  * released, such as in sorele(), but also when named reference flags are
954  * cleared in socket or protocol code.
955  *
956  * sofree() will free the socket if:
957  *
958  * - There are no outstanding file descriptor references or related consumers
959  *   (so_count == 0).
960  *
961  * - The socket has been closed by user space, if ever open (SS_NOFDREF).
962  *
963  * - The protocol does not have an outstanding strong reference on the socket
964  *   (SS_PROTOREF).
965  *
966  * - The socket is not in a completed connection queue, so a process has been
967  *   notified that it is present.  If it is removed, the user process may
968  *   block in accept() despite select() saying the socket was ready.
969  */
970 void
971 sofree(struct socket *so)
972 {
973 	struct protosw *pr = so->so_proto;
974 
975 	SOCK_LOCK_ASSERT(so);
976 
977 	if ((so->so_state & SS_NOFDREF) == 0 || so->so_count != 0 ||
978 	    (so->so_state & SS_PROTOREF) || (so->so_qstate == SQ_COMP)) {
979 		SOCK_UNLOCK(so);
980 		return;
981 	}
982 
983 	if (!SOLISTENING(so) && so->so_qstate == SQ_INCOMP) {
984 		struct socket *sol;
985 
986 		sol = so->so_listen;
987 		KASSERT(sol, ("%s: so %p on incomp of NULL", __func__, so));
988 
989 		/*
990 		 * To solve race between close of a listening socket and
991 		 * a socket on its incomplete queue, we need to lock both.
992 		 * The order is first listening socket, then regular.
993 		 * Since we don't have SS_NOFDREF neither SS_PROTOREF, this
994 		 * function and the listening socket are the only pointers
995 		 * to so.  To preserve so and sol, we reference both and then
996 		 * relock.
997 		 * After relock the socket may not move to so_comp since it
998 		 * doesn't have PCB already, but it may be removed from
999 		 * so_incomp. If that happens, we share responsiblity on
1000 		 * freeing the socket, but soclose() has already removed
1001 		 * it from queue.
1002 		 */
1003 		soref(sol);
1004 		soref(so);
1005 		SOCK_UNLOCK(so);
1006 		SOLISTEN_LOCK(sol);
1007 		SOCK_LOCK(so);
1008 		if (so->so_qstate == SQ_INCOMP) {
1009 			KASSERT(so->so_listen == sol,
1010 			    ("%s: so %p migrated out of sol %p",
1011 			    __func__, so, sol));
1012 			TAILQ_REMOVE(&sol->sol_incomp, so, so_list);
1013 			sol->sol_incqlen--;
1014 			/* This is guarenteed not to be the last. */
1015 			refcount_release(&sol->so_count);
1016 			so->so_qstate = SQ_NONE;
1017 			so->so_listen = NULL;
1018 		} else
1019 			KASSERT(so->so_listen == NULL,
1020 			    ("%s: so %p not on (in)comp with so_listen",
1021 			    __func__, so));
1022 		sorele(sol);
1023 		KASSERT(so->so_count == 1,
1024 		    ("%s: so %p count %u", __func__, so, so->so_count));
1025 		so->so_count = 0;
1026 	}
1027 	if (SOLISTENING(so))
1028 		so->so_error = ECONNABORTED;
1029 	SOCK_UNLOCK(so);
1030 
1031 	if (so->so_dtor != NULL)
1032 		so->so_dtor(so);
1033 
1034 	VNET_SO_ASSERT(so);
1035 	if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose != NULL)
1036 		(*pr->pr_domain->dom_dispose)(so);
1037 	if (pr->pr_usrreqs->pru_detach != NULL)
1038 		(*pr->pr_usrreqs->pru_detach)(so);
1039 
1040 	/*
1041 	 * From this point on, we assume that no other references to this
1042 	 * socket exist anywhere else in the stack.  Therefore, no locks need
1043 	 * to be acquired or held.
1044 	 *
1045 	 * We used to do a lot of socket buffer and socket locking here, as
1046 	 * well as invoke sorflush() and perform wakeups.  The direct call to
1047 	 * dom_dispose() and sbrelease_internal() are an inlining of what was
1048 	 * necessary from sorflush().
1049 	 *
1050 	 * Notice that the socket buffer and kqueue state are torn down
1051 	 * before calling pru_detach.  This means that protocols shold not
1052 	 * assume they can perform socket wakeups, etc, in their detach code.
1053 	 */
1054 	if (!SOLISTENING(so)) {
1055 		sbdestroy(&so->so_snd, so);
1056 		sbdestroy(&so->so_rcv, so);
1057 	}
1058 	seldrain(&so->so_rdsel);
1059 	seldrain(&so->so_wrsel);
1060 	knlist_destroy(&so->so_rdsel.si_note);
1061 	knlist_destroy(&so->so_wrsel.si_note);
1062 	sodealloc(so);
1063 }
1064 
1065 /*
1066  * Close a socket on last file table reference removal.  Initiate disconnect
1067  * if connected.  Free socket when disconnect complete.
1068  *
1069  * This function will sorele() the socket.  Note that soclose() may be called
1070  * prior to the ref count reaching zero.  The actual socket structure will
1071  * not be freed until the ref count reaches zero.
1072  */
1073 int
1074 soclose(struct socket *so)
1075 {
1076 	struct accept_queue lqueue;
1077 	bool listening;
1078 	int error = 0;
1079 
1080 	KASSERT(!(so->so_state & SS_NOFDREF), ("soclose: SS_NOFDREF on enter"));
1081 
1082 	CURVNET_SET(so->so_vnet);
1083 	funsetown(&so->so_sigio);
1084 	if (so->so_state & SS_ISCONNECTED) {
1085 		if ((so->so_state & SS_ISDISCONNECTING) == 0) {
1086 			error = sodisconnect(so);
1087 			if (error) {
1088 				if (error == ENOTCONN)
1089 					error = 0;
1090 				goto drop;
1091 			}
1092 		}
1093 		if (so->so_options & SO_LINGER) {
1094 			if ((so->so_state & SS_ISDISCONNECTING) &&
1095 			    (so->so_state & SS_NBIO))
1096 				goto drop;
1097 			while (so->so_state & SS_ISCONNECTED) {
1098 				error = tsleep(&so->so_timeo,
1099 				    PSOCK | PCATCH, "soclos",
1100 				    so->so_linger * hz);
1101 				if (error)
1102 					break;
1103 			}
1104 		}
1105 	}
1106 
1107 drop:
1108 	if (so->so_proto->pr_usrreqs->pru_close != NULL)
1109 		(*so->so_proto->pr_usrreqs->pru_close)(so);
1110 
1111 	SOCK_LOCK(so);
1112 	if ((listening = (so->so_options & SO_ACCEPTCONN))) {
1113 		struct socket *sp;
1114 
1115 		TAILQ_INIT(&lqueue);
1116 		TAILQ_SWAP(&lqueue, &so->sol_incomp, socket, so_list);
1117 		TAILQ_CONCAT(&lqueue, &so->sol_comp, so_list);
1118 
1119 		so->sol_qlen = so->sol_incqlen = 0;
1120 
1121 		TAILQ_FOREACH(sp, &lqueue, so_list) {
1122 			SOCK_LOCK(sp);
1123 			sp->so_qstate = SQ_NONE;
1124 			sp->so_listen = NULL;
1125 			SOCK_UNLOCK(sp);
1126 			/* Guaranteed not to be the last. */
1127 			refcount_release(&so->so_count);
1128 		}
1129 	}
1130 	KASSERT((so->so_state & SS_NOFDREF) == 0, ("soclose: NOFDREF"));
1131 	so->so_state |= SS_NOFDREF;
1132 	sorele(so);
1133 	if (listening) {
1134 		struct socket *sp;
1135 
1136 		TAILQ_FOREACH(sp, &lqueue, so_list) {
1137 			SOCK_LOCK(sp);
1138 			if (sp->so_count == 0) {
1139 				SOCK_UNLOCK(sp);
1140 				soabort(sp);
1141 			} else
1142 				/* sp is now in sofree() */
1143 				SOCK_UNLOCK(sp);
1144 		}
1145 	}
1146 	CURVNET_RESTORE();
1147 	return (error);
1148 }
1149 
1150 /*
1151  * soabort() is used to abruptly tear down a connection, such as when a
1152  * resource limit is reached (listen queue depth exceeded), or if a listen
1153  * socket is closed while there are sockets waiting to be accepted.
1154  *
1155  * This interface is tricky, because it is called on an unreferenced socket,
1156  * and must be called only by a thread that has actually removed the socket
1157  * from the listen queue it was on, or races with other threads are risked.
1158  *
1159  * This interface will call into the protocol code, so must not be called
1160  * with any socket locks held.  Protocols do call it while holding their own
1161  * recursible protocol mutexes, but this is something that should be subject
1162  * to review in the future.
1163  */
1164 void
1165 soabort(struct socket *so)
1166 {
1167 
1168 	/*
1169 	 * In as much as is possible, assert that no references to this
1170 	 * socket are held.  This is not quite the same as asserting that the
1171 	 * current thread is responsible for arranging for no references, but
1172 	 * is as close as we can get for now.
1173 	 */
1174 	KASSERT(so->so_count == 0, ("soabort: so_count"));
1175 	KASSERT((so->so_state & SS_PROTOREF) == 0, ("soabort: SS_PROTOREF"));
1176 	KASSERT(so->so_state & SS_NOFDREF, ("soabort: !SS_NOFDREF"));
1177 	VNET_SO_ASSERT(so);
1178 
1179 	if (so->so_proto->pr_usrreqs->pru_abort != NULL)
1180 		(*so->so_proto->pr_usrreqs->pru_abort)(so);
1181 	SOCK_LOCK(so);
1182 	sofree(so);
1183 }
1184 
1185 int
1186 soaccept(struct socket *so, struct sockaddr **nam)
1187 {
1188 	int error;
1189 
1190 	SOCK_LOCK(so);
1191 	KASSERT((so->so_state & SS_NOFDREF) != 0, ("soaccept: !NOFDREF"));
1192 	so->so_state &= ~SS_NOFDREF;
1193 	SOCK_UNLOCK(so);
1194 
1195 	CURVNET_SET(so->so_vnet);
1196 	error = (*so->so_proto->pr_usrreqs->pru_accept)(so, nam);
1197 	CURVNET_RESTORE();
1198 	return (error);
1199 }
1200 
1201 int
1202 soconnect(struct socket *so, struct sockaddr *nam, struct thread *td)
1203 {
1204 
1205 	return (soconnectat(AT_FDCWD, so, nam, td));
1206 }
1207 
1208 int
1209 soconnectat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
1210 {
1211 	int error;
1212 
1213 	if (so->so_options & SO_ACCEPTCONN)
1214 		return (EOPNOTSUPP);
1215 
1216 	CURVNET_SET(so->so_vnet);
1217 	/*
1218 	 * If protocol is connection-based, can only connect once.
1219 	 * Otherwise, if connected, try to disconnect first.  This allows
1220 	 * user to disconnect by connecting to, e.g., a null address.
1221 	 */
1222 	if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
1223 	    ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
1224 	    (error = sodisconnect(so)))) {
1225 		error = EISCONN;
1226 	} else {
1227 		/*
1228 		 * Prevent accumulated error from previous connection from
1229 		 * biting us.
1230 		 */
1231 		so->so_error = 0;
1232 		if (fd == AT_FDCWD) {
1233 			error = (*so->so_proto->pr_usrreqs->pru_connect)(so,
1234 			    nam, td);
1235 		} else {
1236 			error = (*so->so_proto->pr_usrreqs->pru_connectat)(fd,
1237 			    so, nam, td);
1238 		}
1239 	}
1240 	CURVNET_RESTORE();
1241 
1242 	return (error);
1243 }
1244 
1245 int
1246 soconnect2(struct socket *so1, struct socket *so2)
1247 {
1248 	int error;
1249 
1250 	CURVNET_SET(so1->so_vnet);
1251 	error = (*so1->so_proto->pr_usrreqs->pru_connect2)(so1, so2);
1252 	CURVNET_RESTORE();
1253 	return (error);
1254 }
1255 
1256 int
1257 sodisconnect(struct socket *so)
1258 {
1259 	int error;
1260 
1261 	if ((so->so_state & SS_ISCONNECTED) == 0)
1262 		return (ENOTCONN);
1263 	if (so->so_state & SS_ISDISCONNECTING)
1264 		return (EALREADY);
1265 	VNET_SO_ASSERT(so);
1266 	error = (*so->so_proto->pr_usrreqs->pru_disconnect)(so);
1267 	return (error);
1268 }
1269 
1270 #define	SBLOCKWAIT(f)	(((f) & MSG_DONTWAIT) ? 0 : SBL_WAIT)
1271 
1272 int
1273 sosend_dgram(struct socket *so, struct sockaddr *addr, struct uio *uio,
1274     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
1275 {
1276 	long space;
1277 	ssize_t resid;
1278 	int clen = 0, error, dontroute;
1279 
1280 	KASSERT(so->so_type == SOCK_DGRAM, ("sosend_dgram: !SOCK_DGRAM"));
1281 	KASSERT(so->so_proto->pr_flags & PR_ATOMIC,
1282 	    ("sosend_dgram: !PR_ATOMIC"));
1283 
1284 	if (uio != NULL)
1285 		resid = uio->uio_resid;
1286 	else
1287 		resid = top->m_pkthdr.len;
1288 	/*
1289 	 * In theory resid should be unsigned.  However, space must be
1290 	 * signed, as it might be less than 0 if we over-committed, and we
1291 	 * must use a signed comparison of space and resid.  On the other
1292 	 * hand, a negative resid causes us to loop sending 0-length
1293 	 * segments to the protocol.
1294 	 */
1295 	if (resid < 0) {
1296 		error = EINVAL;
1297 		goto out;
1298 	}
1299 
1300 	dontroute =
1301 	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0;
1302 	if (td != NULL)
1303 		td->td_ru.ru_msgsnd++;
1304 	if (control != NULL)
1305 		clen = control->m_len;
1306 
1307 	SOCKBUF_LOCK(&so->so_snd);
1308 	if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
1309 		SOCKBUF_UNLOCK(&so->so_snd);
1310 		error = EPIPE;
1311 		goto out;
1312 	}
1313 	if (so->so_error) {
1314 		error = so->so_error;
1315 		so->so_error = 0;
1316 		SOCKBUF_UNLOCK(&so->so_snd);
1317 		goto out;
1318 	}
1319 	if ((so->so_state & SS_ISCONNECTED) == 0) {
1320 		/*
1321 		 * `sendto' and `sendmsg' is allowed on a connection-based
1322 		 * socket if it supports implied connect.  Return ENOTCONN if
1323 		 * not connected and no address is supplied.
1324 		 */
1325 		if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
1326 		    (so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
1327 			if ((so->so_state & SS_ISCONFIRMING) == 0 &&
1328 			    !(resid == 0 && clen != 0)) {
1329 				SOCKBUF_UNLOCK(&so->so_snd);
1330 				error = ENOTCONN;
1331 				goto out;
1332 			}
1333 		} else if (addr == NULL) {
1334 			if (so->so_proto->pr_flags & PR_CONNREQUIRED)
1335 				error = ENOTCONN;
1336 			else
1337 				error = EDESTADDRREQ;
1338 			SOCKBUF_UNLOCK(&so->so_snd);
1339 			goto out;
1340 		}
1341 	}
1342 
1343 	/*
1344 	 * Do we need MSG_OOB support in SOCK_DGRAM?  Signs here may be a
1345 	 * problem and need fixing.
1346 	 */
1347 	space = sbspace(&so->so_snd);
1348 	if (flags & MSG_OOB)
1349 		space += 1024;
1350 	space -= clen;
1351 	SOCKBUF_UNLOCK(&so->so_snd);
1352 	if (resid > space) {
1353 		error = EMSGSIZE;
1354 		goto out;
1355 	}
1356 	if (uio == NULL) {
1357 		resid = 0;
1358 		if (flags & MSG_EOR)
1359 			top->m_flags |= M_EOR;
1360 	} else {
1361 		/*
1362 		 * Copy the data from userland into a mbuf chain.
1363 		 * If no data is to be copied in, a single empty mbuf
1364 		 * is returned.
1365 		 */
1366 		top = m_uiotombuf(uio, M_WAITOK, space, max_hdr,
1367 		    (M_PKTHDR | ((flags & MSG_EOR) ? M_EOR : 0)));
1368 		if (top == NULL) {
1369 			error = EFAULT;	/* only possible error */
1370 			goto out;
1371 		}
1372 		space -= resid - uio->uio_resid;
1373 		resid = uio->uio_resid;
1374 	}
1375 	KASSERT(resid == 0, ("sosend_dgram: resid != 0"));
1376 	/*
1377 	 * XXXRW: Frobbing SO_DONTROUTE here is even worse without sblock
1378 	 * than with.
1379 	 */
1380 	if (dontroute) {
1381 		SOCK_LOCK(so);
1382 		so->so_options |= SO_DONTROUTE;
1383 		SOCK_UNLOCK(so);
1384 	}
1385 	/*
1386 	 * XXX all the SBS_CANTSENDMORE checks previously done could be out
1387 	 * of date.  We could have received a reset packet in an interrupt or
1388 	 * maybe we slept while doing page faults in uiomove() etc.  We could
1389 	 * probably recheck again inside the locking protection here, but
1390 	 * there are probably other places that this also happens.  We must
1391 	 * rethink this.
1392 	 */
1393 	VNET_SO_ASSERT(so);
1394 	error = (*so->so_proto->pr_usrreqs->pru_send)(so,
1395 	    (flags & MSG_OOB) ? PRUS_OOB :
1396 	/*
1397 	 * If the user set MSG_EOF, the protocol understands this flag and
1398 	 * nothing left to send then use PRU_SEND_EOF instead of PRU_SEND.
1399 	 */
1400 	    ((flags & MSG_EOF) &&
1401 	     (so->so_proto->pr_flags & PR_IMPLOPCL) &&
1402 	     (resid <= 0)) ?
1403 		PRUS_EOF :
1404 		/* If there is more to send set PRUS_MORETOCOME */
1405 		(flags & MSG_MORETOCOME) ||
1406 		(resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
1407 		top, addr, control, td);
1408 	if (dontroute) {
1409 		SOCK_LOCK(so);
1410 		so->so_options &= ~SO_DONTROUTE;
1411 		SOCK_UNLOCK(so);
1412 	}
1413 	clen = 0;
1414 	control = NULL;
1415 	top = NULL;
1416 out:
1417 	if (top != NULL)
1418 		m_freem(top);
1419 	if (control != NULL)
1420 		m_freem(control);
1421 	return (error);
1422 }
1423 
1424 /*
1425  * Send on a socket.  If send must go all at once and message is larger than
1426  * send buffering, then hard error.  Lock against other senders.  If must go
1427  * all at once and not enough room now, then inform user that this would
1428  * block and do nothing.  Otherwise, if nonblocking, send as much as
1429  * possible.  The data to be sent is described by "uio" if nonzero, otherwise
1430  * by the mbuf chain "top" (which must be null if uio is not).  Data provided
1431  * in mbuf chain must be small enough to send all at once.
1432  *
1433  * Returns nonzero on error, timeout or signal; callers must check for short
1434  * counts if EINTR/ERESTART are returned.  Data and control buffers are freed
1435  * on return.
1436  */
1437 int
1438 sosend_generic(struct socket *so, struct sockaddr *addr, struct uio *uio,
1439     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
1440 {
1441 	long space;
1442 	ssize_t resid;
1443 	int clen = 0, error, dontroute;
1444 	int atomic = sosendallatonce(so) || top;
1445 
1446 	if (uio != NULL)
1447 		resid = uio->uio_resid;
1448 	else
1449 		resid = top->m_pkthdr.len;
1450 	/*
1451 	 * In theory resid should be unsigned.  However, space must be
1452 	 * signed, as it might be less than 0 if we over-committed, and we
1453 	 * must use a signed comparison of space and resid.  On the other
1454 	 * hand, a negative resid causes us to loop sending 0-length
1455 	 * segments to the protocol.
1456 	 *
1457 	 * Also check to make sure that MSG_EOR isn't used on SOCK_STREAM
1458 	 * type sockets since that's an error.
1459 	 */
1460 	if (resid < 0 || (so->so_type == SOCK_STREAM && (flags & MSG_EOR))) {
1461 		error = EINVAL;
1462 		goto out;
1463 	}
1464 
1465 	dontroute =
1466 	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
1467 	    (so->so_proto->pr_flags & PR_ATOMIC);
1468 	if (td != NULL)
1469 		td->td_ru.ru_msgsnd++;
1470 	if (control != NULL)
1471 		clen = control->m_len;
1472 
1473 	error = sblock(&so->so_snd, SBLOCKWAIT(flags));
1474 	if (error)
1475 		goto out;
1476 
1477 restart:
1478 	do {
1479 		SOCKBUF_LOCK(&so->so_snd);
1480 		if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
1481 			SOCKBUF_UNLOCK(&so->so_snd);
1482 			error = EPIPE;
1483 			goto release;
1484 		}
1485 		if (so->so_error) {
1486 			error = so->so_error;
1487 			so->so_error = 0;
1488 			SOCKBUF_UNLOCK(&so->so_snd);
1489 			goto release;
1490 		}
1491 		if ((so->so_state & SS_ISCONNECTED) == 0) {
1492 			/*
1493 			 * `sendto' and `sendmsg' is allowed on a connection-
1494 			 * based socket if it supports implied connect.
1495 			 * Return ENOTCONN if not connected and no address is
1496 			 * supplied.
1497 			 */
1498 			if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
1499 			    (so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
1500 				if ((so->so_state & SS_ISCONFIRMING) == 0 &&
1501 				    !(resid == 0 && clen != 0)) {
1502 					SOCKBUF_UNLOCK(&so->so_snd);
1503 					error = ENOTCONN;
1504 					goto release;
1505 				}
1506 			} else if (addr == NULL) {
1507 				SOCKBUF_UNLOCK(&so->so_snd);
1508 				if (so->so_proto->pr_flags & PR_CONNREQUIRED)
1509 					error = ENOTCONN;
1510 				else
1511 					error = EDESTADDRREQ;
1512 				goto release;
1513 			}
1514 		}
1515 		space = sbspace(&so->so_snd);
1516 		if (flags & MSG_OOB)
1517 			space += 1024;
1518 		if ((atomic && resid > so->so_snd.sb_hiwat) ||
1519 		    clen > so->so_snd.sb_hiwat) {
1520 			SOCKBUF_UNLOCK(&so->so_snd);
1521 			error = EMSGSIZE;
1522 			goto release;
1523 		}
1524 		if (space < resid + clen &&
1525 		    (atomic || space < so->so_snd.sb_lowat || space < clen)) {
1526 			if ((so->so_state & SS_NBIO) ||
1527 			    (flags & (MSG_NBIO | MSG_DONTWAIT)) != 0) {
1528 				SOCKBUF_UNLOCK(&so->so_snd);
1529 				error = EWOULDBLOCK;
1530 				goto release;
1531 			}
1532 			error = sbwait(&so->so_snd);
1533 			SOCKBUF_UNLOCK(&so->so_snd);
1534 			if (error)
1535 				goto release;
1536 			goto restart;
1537 		}
1538 		SOCKBUF_UNLOCK(&so->so_snd);
1539 		space -= clen;
1540 		do {
1541 			if (uio == NULL) {
1542 				resid = 0;
1543 				if (flags & MSG_EOR)
1544 					top->m_flags |= M_EOR;
1545 			} else {
1546 				/*
1547 				 * Copy the data from userland into a mbuf
1548 				 * chain.  If resid is 0, which can happen
1549 				 * only if we have control to send, then
1550 				 * a single empty mbuf is returned.  This
1551 				 * is a workaround to prevent protocol send
1552 				 * methods to panic.
1553 				 */
1554 				top = m_uiotombuf(uio, M_WAITOK, space,
1555 				    (atomic ? max_hdr : 0),
1556 				    (atomic ? M_PKTHDR : 0) |
1557 				    ((flags & MSG_EOR) ? M_EOR : 0));
1558 				if (top == NULL) {
1559 					error = EFAULT; /* only possible error */
1560 					goto release;
1561 				}
1562 				space -= resid - uio->uio_resid;
1563 				resid = uio->uio_resid;
1564 			}
1565 			if (dontroute) {
1566 				SOCK_LOCK(so);
1567 				so->so_options |= SO_DONTROUTE;
1568 				SOCK_UNLOCK(so);
1569 			}
1570 			/*
1571 			 * XXX all the SBS_CANTSENDMORE checks previously
1572 			 * done could be out of date.  We could have received
1573 			 * a reset packet in an interrupt or maybe we slept
1574 			 * while doing page faults in uiomove() etc.  We
1575 			 * could probably recheck again inside the locking
1576 			 * protection here, but there are probably other
1577 			 * places that this also happens.  We must rethink
1578 			 * this.
1579 			 */
1580 			VNET_SO_ASSERT(so);
1581 			error = (*so->so_proto->pr_usrreqs->pru_send)(so,
1582 			    (flags & MSG_OOB) ? PRUS_OOB :
1583 			/*
1584 			 * If the user set MSG_EOF, the protocol understands
1585 			 * this flag and nothing left to send then use
1586 			 * PRU_SEND_EOF instead of PRU_SEND.
1587 			 */
1588 			    ((flags & MSG_EOF) &&
1589 			     (so->so_proto->pr_flags & PR_IMPLOPCL) &&
1590 			     (resid <= 0)) ?
1591 				PRUS_EOF :
1592 			/* If there is more to send set PRUS_MORETOCOME. */
1593 			    (flags & MSG_MORETOCOME) ||
1594 			    (resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
1595 			    top, addr, control, td);
1596 			if (dontroute) {
1597 				SOCK_LOCK(so);
1598 				so->so_options &= ~SO_DONTROUTE;
1599 				SOCK_UNLOCK(so);
1600 			}
1601 			clen = 0;
1602 			control = NULL;
1603 			top = NULL;
1604 			if (error)
1605 				goto release;
1606 		} while (resid && space > 0);
1607 	} while (resid);
1608 
1609 release:
1610 	sbunlock(&so->so_snd);
1611 out:
1612 	if (top != NULL)
1613 		m_freem(top);
1614 	if (control != NULL)
1615 		m_freem(control);
1616 	return (error);
1617 }
1618 
1619 int
1620 sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
1621     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
1622 {
1623 	int error;
1624 
1625 	CURVNET_SET(so->so_vnet);
1626 	if (!SOLISTENING(so))
1627 		error = so->so_proto->pr_usrreqs->pru_sosend(so, addr, uio,
1628 		    top, control, flags, td);
1629 	else {
1630 		m_freem(top);
1631 		m_freem(control);
1632 		error = ENOTCONN;
1633 	}
1634 	CURVNET_RESTORE();
1635 	return (error);
1636 }
1637 
1638 /*
1639  * The part of soreceive() that implements reading non-inline out-of-band
1640  * data from a socket.  For more complete comments, see soreceive(), from
1641  * which this code originated.
1642  *
1643  * Note that soreceive_rcvoob(), unlike the remainder of soreceive(), is
1644  * unable to return an mbuf chain to the caller.
1645  */
1646 static int
1647 soreceive_rcvoob(struct socket *so, struct uio *uio, int flags)
1648 {
1649 	struct protosw *pr = so->so_proto;
1650 	struct mbuf *m;
1651 	int error;
1652 
1653 	KASSERT(flags & MSG_OOB, ("soreceive_rcvoob: (flags & MSG_OOB) == 0"));
1654 	VNET_SO_ASSERT(so);
1655 
1656 	m = m_get(M_WAITOK, MT_DATA);
1657 	error = (*pr->pr_usrreqs->pru_rcvoob)(so, m, flags & MSG_PEEK);
1658 	if (error)
1659 		goto bad;
1660 	do {
1661 		error = uiomove(mtod(m, void *),
1662 		    (int) min(uio->uio_resid, m->m_len), uio);
1663 		m = m_free(m);
1664 	} while (uio->uio_resid && error == 0 && m);
1665 bad:
1666 	if (m != NULL)
1667 		m_freem(m);
1668 	return (error);
1669 }
1670 
1671 /*
1672  * Following replacement or removal of the first mbuf on the first mbuf chain
1673  * of a socket buffer, push necessary state changes back into the socket
1674  * buffer so that other consumers see the values consistently.  'nextrecord'
1675  * is the callers locally stored value of the original value of
1676  * sb->sb_mb->m_nextpkt which must be restored when the lead mbuf changes.
1677  * NOTE: 'nextrecord' may be NULL.
1678  */
1679 static __inline void
1680 sockbuf_pushsync(struct sockbuf *sb, struct mbuf *nextrecord)
1681 {
1682 
1683 	SOCKBUF_LOCK_ASSERT(sb);
1684 	/*
1685 	 * First, update for the new value of nextrecord.  If necessary, make
1686 	 * it the first record.
1687 	 */
1688 	if (sb->sb_mb != NULL)
1689 		sb->sb_mb->m_nextpkt = nextrecord;
1690 	else
1691 		sb->sb_mb = nextrecord;
1692 
1693 	/*
1694 	 * Now update any dependent socket buffer fields to reflect the new
1695 	 * state.  This is an expanded inline of SB_EMPTY_FIXUP(), with the
1696 	 * addition of a second clause that takes care of the case where
1697 	 * sb_mb has been updated, but remains the last record.
1698 	 */
1699 	if (sb->sb_mb == NULL) {
1700 		sb->sb_mbtail = NULL;
1701 		sb->sb_lastrecord = NULL;
1702 	} else if (sb->sb_mb->m_nextpkt == NULL)
1703 		sb->sb_lastrecord = sb->sb_mb;
1704 }
1705 
1706 /*
1707  * Implement receive operations on a socket.  We depend on the way that
1708  * records are added to the sockbuf by sbappend.  In particular, each record
1709  * (mbufs linked through m_next) must begin with an address if the protocol
1710  * so specifies, followed by an optional mbuf or mbufs containing ancillary
1711  * data, and then zero or more mbufs of data.  In order to allow parallelism
1712  * between network receive and copying to user space, as well as avoid
1713  * sleeping with a mutex held, we release the socket buffer mutex during the
1714  * user space copy.  Although the sockbuf is locked, new data may still be
1715  * appended, and thus we must maintain consistency of the sockbuf during that
1716  * time.
1717  *
1718  * The caller may receive the data as a single mbuf chain by supplying an
1719  * mbuf **mp0 for use in returning the chain.  The uio is then used only for
1720  * the count in uio_resid.
1721  */
1722 int
1723 soreceive_generic(struct socket *so, struct sockaddr **psa, struct uio *uio,
1724     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
1725 {
1726 	struct mbuf *m, **mp;
1727 	int flags, error, offset;
1728 	ssize_t len;
1729 	struct protosw *pr = so->so_proto;
1730 	struct mbuf *nextrecord;
1731 	int moff, type = 0;
1732 	ssize_t orig_resid = uio->uio_resid;
1733 
1734 	mp = mp0;
1735 	if (psa != NULL)
1736 		*psa = NULL;
1737 	if (controlp != NULL)
1738 		*controlp = NULL;
1739 	if (flagsp != NULL)
1740 		flags = *flagsp &~ MSG_EOR;
1741 	else
1742 		flags = 0;
1743 	if (flags & MSG_OOB)
1744 		return (soreceive_rcvoob(so, uio, flags));
1745 	if (mp != NULL)
1746 		*mp = NULL;
1747 	if ((pr->pr_flags & PR_WANTRCVD) && (so->so_state & SS_ISCONFIRMING)
1748 	    && uio->uio_resid) {
1749 		VNET_SO_ASSERT(so);
1750 		(*pr->pr_usrreqs->pru_rcvd)(so, 0);
1751 	}
1752 
1753 	error = sblock(&so->so_rcv, SBLOCKWAIT(flags));
1754 	if (error)
1755 		return (error);
1756 
1757 restart:
1758 	SOCKBUF_LOCK(&so->so_rcv);
1759 	m = so->so_rcv.sb_mb;
1760 	/*
1761 	 * If we have less data than requested, block awaiting more (subject
1762 	 * to any timeout) if:
1763 	 *   1. the current count is less than the low water mark, or
1764 	 *   2. MSG_DONTWAIT is not set
1765 	 */
1766 	if (m == NULL || (((flags & MSG_DONTWAIT) == 0 &&
1767 	    sbavail(&so->so_rcv) < uio->uio_resid) &&
1768 	    sbavail(&so->so_rcv) < so->so_rcv.sb_lowat &&
1769 	    m->m_nextpkt == NULL && (pr->pr_flags & PR_ATOMIC) == 0)) {
1770 		KASSERT(m != NULL || !sbavail(&so->so_rcv),
1771 		    ("receive: m == %p sbavail == %u",
1772 		    m, sbavail(&so->so_rcv)));
1773 		if (so->so_error) {
1774 			if (m != NULL)
1775 				goto dontblock;
1776 			error = so->so_error;
1777 			if ((flags & MSG_PEEK) == 0)
1778 				so->so_error = 0;
1779 			SOCKBUF_UNLOCK(&so->so_rcv);
1780 			goto release;
1781 		}
1782 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1783 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
1784 			if (m == NULL) {
1785 				SOCKBUF_UNLOCK(&so->so_rcv);
1786 				goto release;
1787 			} else
1788 				goto dontblock;
1789 		}
1790 		for (; m != NULL; m = m->m_next)
1791 			if (m->m_type == MT_OOBDATA  || (m->m_flags & M_EOR)) {
1792 				m = so->so_rcv.sb_mb;
1793 				goto dontblock;
1794 			}
1795 		if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
1796 		    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
1797 			SOCKBUF_UNLOCK(&so->so_rcv);
1798 			error = ENOTCONN;
1799 			goto release;
1800 		}
1801 		if (uio->uio_resid == 0) {
1802 			SOCKBUF_UNLOCK(&so->so_rcv);
1803 			goto release;
1804 		}
1805 		if ((so->so_state & SS_NBIO) ||
1806 		    (flags & (MSG_DONTWAIT|MSG_NBIO))) {
1807 			SOCKBUF_UNLOCK(&so->so_rcv);
1808 			error = EWOULDBLOCK;
1809 			goto release;
1810 		}
1811 		SBLASTRECORDCHK(&so->so_rcv);
1812 		SBLASTMBUFCHK(&so->so_rcv);
1813 		error = sbwait(&so->so_rcv);
1814 		SOCKBUF_UNLOCK(&so->so_rcv);
1815 		if (error)
1816 			goto release;
1817 		goto restart;
1818 	}
1819 dontblock:
1820 	/*
1821 	 * From this point onward, we maintain 'nextrecord' as a cache of the
1822 	 * pointer to the next record in the socket buffer.  We must keep the
1823 	 * various socket buffer pointers and local stack versions of the
1824 	 * pointers in sync, pushing out modifications before dropping the
1825 	 * socket buffer mutex, and re-reading them when picking it up.
1826 	 *
1827 	 * Otherwise, we will race with the network stack appending new data
1828 	 * or records onto the socket buffer by using inconsistent/stale
1829 	 * versions of the field, possibly resulting in socket buffer
1830 	 * corruption.
1831 	 *
1832 	 * By holding the high-level sblock(), we prevent simultaneous
1833 	 * readers from pulling off the front of the socket buffer.
1834 	 */
1835 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1836 	if (uio->uio_td)
1837 		uio->uio_td->td_ru.ru_msgrcv++;
1838 	KASSERT(m == so->so_rcv.sb_mb, ("soreceive: m != so->so_rcv.sb_mb"));
1839 	SBLASTRECORDCHK(&so->so_rcv);
1840 	SBLASTMBUFCHK(&so->so_rcv);
1841 	nextrecord = m->m_nextpkt;
1842 	if (pr->pr_flags & PR_ADDR) {
1843 		KASSERT(m->m_type == MT_SONAME,
1844 		    ("m->m_type == %d", m->m_type));
1845 		orig_resid = 0;
1846 		if (psa != NULL)
1847 			*psa = sodupsockaddr(mtod(m, struct sockaddr *),
1848 			    M_NOWAIT);
1849 		if (flags & MSG_PEEK) {
1850 			m = m->m_next;
1851 		} else {
1852 			sbfree(&so->so_rcv, m);
1853 			so->so_rcv.sb_mb = m_free(m);
1854 			m = so->so_rcv.sb_mb;
1855 			sockbuf_pushsync(&so->so_rcv, nextrecord);
1856 		}
1857 	}
1858 
1859 	/*
1860 	 * Process one or more MT_CONTROL mbufs present before any data mbufs
1861 	 * in the first mbuf chain on the socket buffer.  If MSG_PEEK, we
1862 	 * just copy the data; if !MSG_PEEK, we call into the protocol to
1863 	 * perform externalization (or freeing if controlp == NULL).
1864 	 */
1865 	if (m != NULL && m->m_type == MT_CONTROL) {
1866 		struct mbuf *cm = NULL, *cmn;
1867 		struct mbuf **cme = &cm;
1868 
1869 		do {
1870 			if (flags & MSG_PEEK) {
1871 				if (controlp != NULL) {
1872 					*controlp = m_copym(m, 0, m->m_len,
1873 					    M_NOWAIT);
1874 					controlp = &(*controlp)->m_next;
1875 				}
1876 				m = m->m_next;
1877 			} else {
1878 				sbfree(&so->so_rcv, m);
1879 				so->so_rcv.sb_mb = m->m_next;
1880 				m->m_next = NULL;
1881 				*cme = m;
1882 				cme = &(*cme)->m_next;
1883 				m = so->so_rcv.sb_mb;
1884 			}
1885 		} while (m != NULL && m->m_type == MT_CONTROL);
1886 		if ((flags & MSG_PEEK) == 0)
1887 			sockbuf_pushsync(&so->so_rcv, nextrecord);
1888 		while (cm != NULL) {
1889 			cmn = cm->m_next;
1890 			cm->m_next = NULL;
1891 			if (pr->pr_domain->dom_externalize != NULL) {
1892 				SOCKBUF_UNLOCK(&so->so_rcv);
1893 				VNET_SO_ASSERT(so);
1894 				error = (*pr->pr_domain->dom_externalize)
1895 				    (cm, controlp, flags);
1896 				SOCKBUF_LOCK(&so->so_rcv);
1897 			} else if (controlp != NULL)
1898 				*controlp = cm;
1899 			else
1900 				m_freem(cm);
1901 			if (controlp != NULL) {
1902 				orig_resid = 0;
1903 				while (*controlp != NULL)
1904 					controlp = &(*controlp)->m_next;
1905 			}
1906 			cm = cmn;
1907 		}
1908 		if (m != NULL)
1909 			nextrecord = so->so_rcv.sb_mb->m_nextpkt;
1910 		else
1911 			nextrecord = so->so_rcv.sb_mb;
1912 		orig_resid = 0;
1913 	}
1914 	if (m != NULL) {
1915 		if ((flags & MSG_PEEK) == 0) {
1916 			KASSERT(m->m_nextpkt == nextrecord,
1917 			    ("soreceive: post-control, nextrecord !sync"));
1918 			if (nextrecord == NULL) {
1919 				KASSERT(so->so_rcv.sb_mb == m,
1920 				    ("soreceive: post-control, sb_mb!=m"));
1921 				KASSERT(so->so_rcv.sb_lastrecord == m,
1922 				    ("soreceive: post-control, lastrecord!=m"));
1923 			}
1924 		}
1925 		type = m->m_type;
1926 		if (type == MT_OOBDATA)
1927 			flags |= MSG_OOB;
1928 	} else {
1929 		if ((flags & MSG_PEEK) == 0) {
1930 			KASSERT(so->so_rcv.sb_mb == nextrecord,
1931 			    ("soreceive: sb_mb != nextrecord"));
1932 			if (so->so_rcv.sb_mb == NULL) {
1933 				KASSERT(so->so_rcv.sb_lastrecord == NULL,
1934 				    ("soreceive: sb_lastercord != NULL"));
1935 			}
1936 		}
1937 	}
1938 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1939 	SBLASTRECORDCHK(&so->so_rcv);
1940 	SBLASTMBUFCHK(&so->so_rcv);
1941 
1942 	/*
1943 	 * Now continue to read any data mbufs off of the head of the socket
1944 	 * buffer until the read request is satisfied.  Note that 'type' is
1945 	 * used to store the type of any mbuf reads that have happened so far
1946 	 * such that soreceive() can stop reading if the type changes, which
1947 	 * causes soreceive() to return only one of regular data and inline
1948 	 * out-of-band data in a single socket receive operation.
1949 	 */
1950 	moff = 0;
1951 	offset = 0;
1952 	while (m != NULL && !(m->m_flags & M_NOTAVAIL) && uio->uio_resid > 0
1953 	    && error == 0) {
1954 		/*
1955 		 * If the type of mbuf has changed since the last mbuf
1956 		 * examined ('type'), end the receive operation.
1957 		 */
1958 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1959 		if (m->m_type == MT_OOBDATA || m->m_type == MT_CONTROL) {
1960 			if (type != m->m_type)
1961 				break;
1962 		} else if (type == MT_OOBDATA)
1963 			break;
1964 		else
1965 		    KASSERT(m->m_type == MT_DATA,
1966 			("m->m_type == %d", m->m_type));
1967 		so->so_rcv.sb_state &= ~SBS_RCVATMARK;
1968 		len = uio->uio_resid;
1969 		if (so->so_oobmark && len > so->so_oobmark - offset)
1970 			len = so->so_oobmark - offset;
1971 		if (len > m->m_len - moff)
1972 			len = m->m_len - moff;
1973 		/*
1974 		 * If mp is set, just pass back the mbufs.  Otherwise copy
1975 		 * them out via the uio, then free.  Sockbuf must be
1976 		 * consistent here (points to current mbuf, it points to next
1977 		 * record) when we drop priority; we must note any additions
1978 		 * to the sockbuf when we block interrupts again.
1979 		 */
1980 		if (mp == NULL) {
1981 			SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1982 			SBLASTRECORDCHK(&so->so_rcv);
1983 			SBLASTMBUFCHK(&so->so_rcv);
1984 			SOCKBUF_UNLOCK(&so->so_rcv);
1985 			error = uiomove(mtod(m, char *) + moff, (int)len, uio);
1986 			SOCKBUF_LOCK(&so->so_rcv);
1987 			if (error) {
1988 				/*
1989 				 * The MT_SONAME mbuf has already been removed
1990 				 * from the record, so it is necessary to
1991 				 * remove the data mbufs, if any, to preserve
1992 				 * the invariant in the case of PR_ADDR that
1993 				 * requires MT_SONAME mbufs at the head of
1994 				 * each record.
1995 				 */
1996 				if (pr->pr_flags & PR_ATOMIC &&
1997 				    ((flags & MSG_PEEK) == 0))
1998 					(void)sbdroprecord_locked(&so->so_rcv);
1999 				SOCKBUF_UNLOCK(&so->so_rcv);
2000 				goto release;
2001 			}
2002 		} else
2003 			uio->uio_resid -= len;
2004 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2005 		if (len == m->m_len - moff) {
2006 			if (m->m_flags & M_EOR)
2007 				flags |= MSG_EOR;
2008 			if (flags & MSG_PEEK) {
2009 				m = m->m_next;
2010 				moff = 0;
2011 			} else {
2012 				nextrecord = m->m_nextpkt;
2013 				sbfree(&so->so_rcv, m);
2014 				if (mp != NULL) {
2015 					m->m_nextpkt = NULL;
2016 					*mp = m;
2017 					mp = &m->m_next;
2018 					so->so_rcv.sb_mb = m = m->m_next;
2019 					*mp = NULL;
2020 				} else {
2021 					so->so_rcv.sb_mb = m_free(m);
2022 					m = so->so_rcv.sb_mb;
2023 				}
2024 				sockbuf_pushsync(&so->so_rcv, nextrecord);
2025 				SBLASTRECORDCHK(&so->so_rcv);
2026 				SBLASTMBUFCHK(&so->so_rcv);
2027 			}
2028 		} else {
2029 			if (flags & MSG_PEEK)
2030 				moff += len;
2031 			else {
2032 				if (mp != NULL) {
2033 					if (flags & MSG_DONTWAIT) {
2034 						*mp = m_copym(m, 0, len,
2035 						    M_NOWAIT);
2036 						if (*mp == NULL) {
2037 							/*
2038 							 * m_copym() couldn't
2039 							 * allocate an mbuf.
2040 							 * Adjust uio_resid back
2041 							 * (it was adjusted
2042 							 * down by len bytes,
2043 							 * which we didn't end
2044 							 * up "copying" over).
2045 							 */
2046 							uio->uio_resid += len;
2047 							break;
2048 						}
2049 					} else {
2050 						SOCKBUF_UNLOCK(&so->so_rcv);
2051 						*mp = m_copym(m, 0, len,
2052 						    M_WAITOK);
2053 						SOCKBUF_LOCK(&so->so_rcv);
2054 					}
2055 				}
2056 				sbcut_locked(&so->so_rcv, len);
2057 			}
2058 		}
2059 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2060 		if (so->so_oobmark) {
2061 			if ((flags & MSG_PEEK) == 0) {
2062 				so->so_oobmark -= len;
2063 				if (so->so_oobmark == 0) {
2064 					so->so_rcv.sb_state |= SBS_RCVATMARK;
2065 					break;
2066 				}
2067 			} else {
2068 				offset += len;
2069 				if (offset == so->so_oobmark)
2070 					break;
2071 			}
2072 		}
2073 		if (flags & MSG_EOR)
2074 			break;
2075 		/*
2076 		 * If the MSG_WAITALL flag is set (for non-atomic socket), we
2077 		 * must not quit until "uio->uio_resid == 0" or an error
2078 		 * termination.  If a signal/timeout occurs, return with a
2079 		 * short count but without error.  Keep sockbuf locked
2080 		 * against other readers.
2081 		 */
2082 		while (flags & MSG_WAITALL && m == NULL && uio->uio_resid > 0 &&
2083 		    !sosendallatonce(so) && nextrecord == NULL) {
2084 			SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2085 			if (so->so_error ||
2086 			    so->so_rcv.sb_state & SBS_CANTRCVMORE)
2087 				break;
2088 			/*
2089 			 * Notify the protocol that some data has been
2090 			 * drained before blocking.
2091 			 */
2092 			if (pr->pr_flags & PR_WANTRCVD) {
2093 				SOCKBUF_UNLOCK(&so->so_rcv);
2094 				VNET_SO_ASSERT(so);
2095 				(*pr->pr_usrreqs->pru_rcvd)(so, flags);
2096 				SOCKBUF_LOCK(&so->so_rcv);
2097 			}
2098 			SBLASTRECORDCHK(&so->so_rcv);
2099 			SBLASTMBUFCHK(&so->so_rcv);
2100 			/*
2101 			 * We could receive some data while was notifying
2102 			 * the protocol. Skip blocking in this case.
2103 			 */
2104 			if (so->so_rcv.sb_mb == NULL) {
2105 				error = sbwait(&so->so_rcv);
2106 				if (error) {
2107 					SOCKBUF_UNLOCK(&so->so_rcv);
2108 					goto release;
2109 				}
2110 			}
2111 			m = so->so_rcv.sb_mb;
2112 			if (m != NULL)
2113 				nextrecord = m->m_nextpkt;
2114 		}
2115 	}
2116 
2117 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2118 	if (m != NULL && pr->pr_flags & PR_ATOMIC) {
2119 		flags |= MSG_TRUNC;
2120 		if ((flags & MSG_PEEK) == 0)
2121 			(void) sbdroprecord_locked(&so->so_rcv);
2122 	}
2123 	if ((flags & MSG_PEEK) == 0) {
2124 		if (m == NULL) {
2125 			/*
2126 			 * First part is an inline SB_EMPTY_FIXUP().  Second
2127 			 * part makes sure sb_lastrecord is up-to-date if
2128 			 * there is still data in the socket buffer.
2129 			 */
2130 			so->so_rcv.sb_mb = nextrecord;
2131 			if (so->so_rcv.sb_mb == NULL) {
2132 				so->so_rcv.sb_mbtail = NULL;
2133 				so->so_rcv.sb_lastrecord = NULL;
2134 			} else if (nextrecord->m_nextpkt == NULL)
2135 				so->so_rcv.sb_lastrecord = nextrecord;
2136 		}
2137 		SBLASTRECORDCHK(&so->so_rcv);
2138 		SBLASTMBUFCHK(&so->so_rcv);
2139 		/*
2140 		 * If soreceive() is being done from the socket callback,
2141 		 * then don't need to generate ACK to peer to update window,
2142 		 * since ACK will be generated on return to TCP.
2143 		 */
2144 		if (!(flags & MSG_SOCALLBCK) &&
2145 		    (pr->pr_flags & PR_WANTRCVD)) {
2146 			SOCKBUF_UNLOCK(&so->so_rcv);
2147 			VNET_SO_ASSERT(so);
2148 			(*pr->pr_usrreqs->pru_rcvd)(so, flags);
2149 			SOCKBUF_LOCK(&so->so_rcv);
2150 		}
2151 	}
2152 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2153 	if (orig_resid == uio->uio_resid && orig_resid &&
2154 	    (flags & MSG_EOR) == 0 && (so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0) {
2155 		SOCKBUF_UNLOCK(&so->so_rcv);
2156 		goto restart;
2157 	}
2158 	SOCKBUF_UNLOCK(&so->so_rcv);
2159 
2160 	if (flagsp != NULL)
2161 		*flagsp |= flags;
2162 release:
2163 	sbunlock(&so->so_rcv);
2164 	return (error);
2165 }
2166 
2167 /*
2168  * Optimized version of soreceive() for stream (TCP) sockets.
2169  */
2170 int
2171 soreceive_stream(struct socket *so, struct sockaddr **psa, struct uio *uio,
2172     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2173 {
2174 	int len = 0, error = 0, flags, oresid;
2175 	struct sockbuf *sb;
2176 	struct mbuf *m, *n = NULL;
2177 
2178 	/* We only do stream sockets. */
2179 	if (so->so_type != SOCK_STREAM)
2180 		return (EINVAL);
2181 	if (psa != NULL)
2182 		*psa = NULL;
2183 	if (flagsp != NULL)
2184 		flags = *flagsp &~ MSG_EOR;
2185 	else
2186 		flags = 0;
2187 	if (controlp != NULL)
2188 		*controlp = NULL;
2189 	if (flags & MSG_OOB)
2190 		return (soreceive_rcvoob(so, uio, flags));
2191 	if (mp0 != NULL)
2192 		*mp0 = NULL;
2193 
2194 	sb = &so->so_rcv;
2195 
2196 	/* Prevent other readers from entering the socket. */
2197 	error = sblock(sb, SBLOCKWAIT(flags));
2198 	if (error)
2199 		goto out;
2200 	SOCKBUF_LOCK(sb);
2201 
2202 	/* Easy one, no space to copyout anything. */
2203 	if (uio->uio_resid == 0) {
2204 		error = EINVAL;
2205 		goto out;
2206 	}
2207 	oresid = uio->uio_resid;
2208 
2209 	/* We will never ever get anything unless we are or were connected. */
2210 	if (!(so->so_state & (SS_ISCONNECTED|SS_ISDISCONNECTED))) {
2211 		error = ENOTCONN;
2212 		goto out;
2213 	}
2214 
2215 restart:
2216 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2217 
2218 	/* Abort if socket has reported problems. */
2219 	if (so->so_error) {
2220 		if (sbavail(sb) > 0)
2221 			goto deliver;
2222 		if (oresid > uio->uio_resid)
2223 			goto out;
2224 		error = so->so_error;
2225 		if (!(flags & MSG_PEEK))
2226 			so->so_error = 0;
2227 		goto out;
2228 	}
2229 
2230 	/* Door is closed.  Deliver what is left, if any. */
2231 	if (sb->sb_state & SBS_CANTRCVMORE) {
2232 		if (sbavail(sb) > 0)
2233 			goto deliver;
2234 		else
2235 			goto out;
2236 	}
2237 
2238 	/* Socket buffer is empty and we shall not block. */
2239 	if (sbavail(sb) == 0 &&
2240 	    ((so->so_state & SS_NBIO) || (flags & (MSG_DONTWAIT|MSG_NBIO)))) {
2241 		error = EAGAIN;
2242 		goto out;
2243 	}
2244 
2245 	/* Socket buffer got some data that we shall deliver now. */
2246 	if (sbavail(sb) > 0 && !(flags & MSG_WAITALL) &&
2247 	    ((so->so_state & SS_NBIO) ||
2248 	     (flags & (MSG_DONTWAIT|MSG_NBIO)) ||
2249 	     sbavail(sb) >= sb->sb_lowat ||
2250 	     sbavail(sb) >= uio->uio_resid ||
2251 	     sbavail(sb) >= sb->sb_hiwat) ) {
2252 		goto deliver;
2253 	}
2254 
2255 	/* On MSG_WAITALL we must wait until all data or error arrives. */
2256 	if ((flags & MSG_WAITALL) &&
2257 	    (sbavail(sb) >= uio->uio_resid || sbavail(sb) >= sb->sb_hiwat))
2258 		goto deliver;
2259 
2260 	/*
2261 	 * Wait and block until (more) data comes in.
2262 	 * NB: Drops the sockbuf lock during wait.
2263 	 */
2264 	error = sbwait(sb);
2265 	if (error)
2266 		goto out;
2267 	goto restart;
2268 
2269 deliver:
2270 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2271 	KASSERT(sbavail(sb) > 0, ("%s: sockbuf empty", __func__));
2272 	KASSERT(sb->sb_mb != NULL, ("%s: sb_mb == NULL", __func__));
2273 
2274 	/* Statistics. */
2275 	if (uio->uio_td)
2276 		uio->uio_td->td_ru.ru_msgrcv++;
2277 
2278 	/* Fill uio until full or current end of socket buffer is reached. */
2279 	len = min(uio->uio_resid, sbavail(sb));
2280 	if (mp0 != NULL) {
2281 		/* Dequeue as many mbufs as possible. */
2282 		if (!(flags & MSG_PEEK) && len >= sb->sb_mb->m_len) {
2283 			if (*mp0 == NULL)
2284 				*mp0 = sb->sb_mb;
2285 			else
2286 				m_cat(*mp0, sb->sb_mb);
2287 			for (m = sb->sb_mb;
2288 			     m != NULL && m->m_len <= len;
2289 			     m = m->m_next) {
2290 				KASSERT(!(m->m_flags & M_NOTAVAIL),
2291 				    ("%s: m %p not available", __func__, m));
2292 				len -= m->m_len;
2293 				uio->uio_resid -= m->m_len;
2294 				sbfree(sb, m);
2295 				n = m;
2296 			}
2297 			n->m_next = NULL;
2298 			sb->sb_mb = m;
2299 			sb->sb_lastrecord = sb->sb_mb;
2300 			if (sb->sb_mb == NULL)
2301 				SB_EMPTY_FIXUP(sb);
2302 		}
2303 		/* Copy the remainder. */
2304 		if (len > 0) {
2305 			KASSERT(sb->sb_mb != NULL,
2306 			    ("%s: len > 0 && sb->sb_mb empty", __func__));
2307 
2308 			m = m_copym(sb->sb_mb, 0, len, M_NOWAIT);
2309 			if (m == NULL)
2310 				len = 0;	/* Don't flush data from sockbuf. */
2311 			else
2312 				uio->uio_resid -= len;
2313 			if (*mp0 != NULL)
2314 				m_cat(*mp0, m);
2315 			else
2316 				*mp0 = m;
2317 			if (*mp0 == NULL) {
2318 				error = ENOBUFS;
2319 				goto out;
2320 			}
2321 		}
2322 	} else {
2323 		/* NB: Must unlock socket buffer as uiomove may sleep. */
2324 		SOCKBUF_UNLOCK(sb);
2325 		error = m_mbuftouio(uio, sb->sb_mb, len);
2326 		SOCKBUF_LOCK(sb);
2327 		if (error)
2328 			goto out;
2329 	}
2330 	SBLASTRECORDCHK(sb);
2331 	SBLASTMBUFCHK(sb);
2332 
2333 	/*
2334 	 * Remove the delivered data from the socket buffer unless we
2335 	 * were only peeking.
2336 	 */
2337 	if (!(flags & MSG_PEEK)) {
2338 		if (len > 0)
2339 			sbdrop_locked(sb, len);
2340 
2341 		/* Notify protocol that we drained some data. */
2342 		if ((so->so_proto->pr_flags & PR_WANTRCVD) &&
2343 		    (((flags & MSG_WAITALL) && uio->uio_resid > 0) ||
2344 		     !(flags & MSG_SOCALLBCK))) {
2345 			SOCKBUF_UNLOCK(sb);
2346 			VNET_SO_ASSERT(so);
2347 			(*so->so_proto->pr_usrreqs->pru_rcvd)(so, flags);
2348 			SOCKBUF_LOCK(sb);
2349 		}
2350 	}
2351 
2352 	/*
2353 	 * For MSG_WAITALL we may have to loop again and wait for
2354 	 * more data to come in.
2355 	 */
2356 	if ((flags & MSG_WAITALL) && uio->uio_resid > 0)
2357 		goto restart;
2358 out:
2359 	SOCKBUF_LOCK_ASSERT(sb);
2360 	SBLASTRECORDCHK(sb);
2361 	SBLASTMBUFCHK(sb);
2362 	SOCKBUF_UNLOCK(sb);
2363 	sbunlock(sb);
2364 	return (error);
2365 }
2366 
2367 /*
2368  * Optimized version of soreceive() for simple datagram cases from userspace.
2369  * Unlike in the stream case, we're able to drop a datagram if copyout()
2370  * fails, and because we handle datagrams atomically, we don't need to use a
2371  * sleep lock to prevent I/O interlacing.
2372  */
2373 int
2374 soreceive_dgram(struct socket *so, struct sockaddr **psa, struct uio *uio,
2375     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2376 {
2377 	struct mbuf *m, *m2;
2378 	int flags, error;
2379 	ssize_t len;
2380 	struct protosw *pr = so->so_proto;
2381 	struct mbuf *nextrecord;
2382 
2383 	if (psa != NULL)
2384 		*psa = NULL;
2385 	if (controlp != NULL)
2386 		*controlp = NULL;
2387 	if (flagsp != NULL)
2388 		flags = *flagsp &~ MSG_EOR;
2389 	else
2390 		flags = 0;
2391 
2392 	/*
2393 	 * For any complicated cases, fall back to the full
2394 	 * soreceive_generic().
2395 	 */
2396 	if (mp0 != NULL || (flags & MSG_PEEK) || (flags & MSG_OOB))
2397 		return (soreceive_generic(so, psa, uio, mp0, controlp,
2398 		    flagsp));
2399 
2400 	/*
2401 	 * Enforce restrictions on use.
2402 	 */
2403 	KASSERT((pr->pr_flags & PR_WANTRCVD) == 0,
2404 	    ("soreceive_dgram: wantrcvd"));
2405 	KASSERT(pr->pr_flags & PR_ATOMIC, ("soreceive_dgram: !atomic"));
2406 	KASSERT((so->so_rcv.sb_state & SBS_RCVATMARK) == 0,
2407 	    ("soreceive_dgram: SBS_RCVATMARK"));
2408 	KASSERT((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0,
2409 	    ("soreceive_dgram: P_CONNREQUIRED"));
2410 
2411 	/*
2412 	 * Loop blocking while waiting for a datagram.
2413 	 */
2414 	SOCKBUF_LOCK(&so->so_rcv);
2415 	while ((m = so->so_rcv.sb_mb) == NULL) {
2416 		KASSERT(sbavail(&so->so_rcv) == 0,
2417 		    ("soreceive_dgram: sb_mb NULL but sbavail %u",
2418 		    sbavail(&so->so_rcv)));
2419 		if (so->so_error) {
2420 			error = so->so_error;
2421 			so->so_error = 0;
2422 			SOCKBUF_UNLOCK(&so->so_rcv);
2423 			return (error);
2424 		}
2425 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE ||
2426 		    uio->uio_resid == 0) {
2427 			SOCKBUF_UNLOCK(&so->so_rcv);
2428 			return (0);
2429 		}
2430 		if ((so->so_state & SS_NBIO) ||
2431 		    (flags & (MSG_DONTWAIT|MSG_NBIO))) {
2432 			SOCKBUF_UNLOCK(&so->so_rcv);
2433 			return (EWOULDBLOCK);
2434 		}
2435 		SBLASTRECORDCHK(&so->so_rcv);
2436 		SBLASTMBUFCHK(&so->so_rcv);
2437 		error = sbwait(&so->so_rcv);
2438 		if (error) {
2439 			SOCKBUF_UNLOCK(&so->so_rcv);
2440 			return (error);
2441 		}
2442 	}
2443 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2444 
2445 	if (uio->uio_td)
2446 		uio->uio_td->td_ru.ru_msgrcv++;
2447 	SBLASTRECORDCHK(&so->so_rcv);
2448 	SBLASTMBUFCHK(&so->so_rcv);
2449 	nextrecord = m->m_nextpkt;
2450 	if (nextrecord == NULL) {
2451 		KASSERT(so->so_rcv.sb_lastrecord == m,
2452 		    ("soreceive_dgram: lastrecord != m"));
2453 	}
2454 
2455 	KASSERT(so->so_rcv.sb_mb->m_nextpkt == nextrecord,
2456 	    ("soreceive_dgram: m_nextpkt != nextrecord"));
2457 
2458 	/*
2459 	 * Pull 'm' and its chain off the front of the packet queue.
2460 	 */
2461 	so->so_rcv.sb_mb = NULL;
2462 	sockbuf_pushsync(&so->so_rcv, nextrecord);
2463 
2464 	/*
2465 	 * Walk 'm's chain and free that many bytes from the socket buffer.
2466 	 */
2467 	for (m2 = m; m2 != NULL; m2 = m2->m_next)
2468 		sbfree(&so->so_rcv, m2);
2469 
2470 	/*
2471 	 * Do a few last checks before we let go of the lock.
2472 	 */
2473 	SBLASTRECORDCHK(&so->so_rcv);
2474 	SBLASTMBUFCHK(&so->so_rcv);
2475 	SOCKBUF_UNLOCK(&so->so_rcv);
2476 
2477 	if (pr->pr_flags & PR_ADDR) {
2478 		KASSERT(m->m_type == MT_SONAME,
2479 		    ("m->m_type == %d", m->m_type));
2480 		if (psa != NULL)
2481 			*psa = sodupsockaddr(mtod(m, struct sockaddr *),
2482 			    M_NOWAIT);
2483 		m = m_free(m);
2484 	}
2485 	if (m == NULL) {
2486 		/* XXXRW: Can this happen? */
2487 		return (0);
2488 	}
2489 
2490 	/*
2491 	 * Packet to copyout() is now in 'm' and it is disconnected from the
2492 	 * queue.
2493 	 *
2494 	 * Process one or more MT_CONTROL mbufs present before any data mbufs
2495 	 * in the first mbuf chain on the socket buffer.  We call into the
2496 	 * protocol to perform externalization (or freeing if controlp ==
2497 	 * NULL). In some cases there can be only MT_CONTROL mbufs without
2498 	 * MT_DATA mbufs.
2499 	 */
2500 	if (m->m_type == MT_CONTROL) {
2501 		struct mbuf *cm = NULL, *cmn;
2502 		struct mbuf **cme = &cm;
2503 
2504 		do {
2505 			m2 = m->m_next;
2506 			m->m_next = NULL;
2507 			*cme = m;
2508 			cme = &(*cme)->m_next;
2509 			m = m2;
2510 		} while (m != NULL && m->m_type == MT_CONTROL);
2511 		while (cm != NULL) {
2512 			cmn = cm->m_next;
2513 			cm->m_next = NULL;
2514 			if (pr->pr_domain->dom_externalize != NULL) {
2515 				error = (*pr->pr_domain->dom_externalize)
2516 				    (cm, controlp, flags);
2517 			} else if (controlp != NULL)
2518 				*controlp = cm;
2519 			else
2520 				m_freem(cm);
2521 			if (controlp != NULL) {
2522 				while (*controlp != NULL)
2523 					controlp = &(*controlp)->m_next;
2524 			}
2525 			cm = cmn;
2526 		}
2527 	}
2528 	KASSERT(m == NULL || m->m_type == MT_DATA,
2529 	    ("soreceive_dgram: !data"));
2530 	while (m != NULL && uio->uio_resid > 0) {
2531 		len = uio->uio_resid;
2532 		if (len > m->m_len)
2533 			len = m->m_len;
2534 		error = uiomove(mtod(m, char *), (int)len, uio);
2535 		if (error) {
2536 			m_freem(m);
2537 			return (error);
2538 		}
2539 		if (len == m->m_len)
2540 			m = m_free(m);
2541 		else {
2542 			m->m_data += len;
2543 			m->m_len -= len;
2544 		}
2545 	}
2546 	if (m != NULL) {
2547 		flags |= MSG_TRUNC;
2548 		m_freem(m);
2549 	}
2550 	if (flagsp != NULL)
2551 		*flagsp |= flags;
2552 	return (0);
2553 }
2554 
2555 int
2556 soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
2557     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2558 {
2559 	int error;
2560 
2561 	CURVNET_SET(so->so_vnet);
2562 	if (!SOLISTENING(so))
2563 		error = (so->so_proto->pr_usrreqs->pru_soreceive(so, psa, uio,
2564 		    mp0, controlp, flagsp));
2565 	else
2566 		error = ENOTCONN;
2567 	CURVNET_RESTORE();
2568 	return (error);
2569 }
2570 
2571 int
2572 soshutdown(struct socket *so, int how)
2573 {
2574 	struct protosw *pr = so->so_proto;
2575 	int error, soerror_enotconn;
2576 
2577 	if (!(how == SHUT_RD || how == SHUT_WR || how == SHUT_RDWR))
2578 		return (EINVAL);
2579 
2580 	soerror_enotconn = 0;
2581 	if ((so->so_state &
2582 	    (SS_ISCONNECTED | SS_ISCONNECTING | SS_ISDISCONNECTING)) == 0) {
2583 		/*
2584 		 * POSIX mandates us to return ENOTCONN when shutdown(2) is
2585 		 * invoked on a datagram sockets, however historically we would
2586 		 * actually tear socket down. This is known to be leveraged by
2587 		 * some applications to unblock process waiting in recvXXX(2)
2588 		 * by other process that it shares that socket with. Try to meet
2589 		 * both backward-compatibility and POSIX requirements by forcing
2590 		 * ENOTCONN but still asking protocol to perform pru_shutdown().
2591 		 */
2592 		if (so->so_type != SOCK_DGRAM && !SOLISTENING(so))
2593 			return (ENOTCONN);
2594 		soerror_enotconn = 1;
2595 	}
2596 
2597 	if (SOLISTENING(so)) {
2598 		if (how != SHUT_WR) {
2599 			SOLISTEN_LOCK(so);
2600 			so->so_error = ECONNABORTED;
2601 			solisten_wakeup(so);	/* unlocks so */
2602 		}
2603 		goto done;
2604 	}
2605 
2606 	CURVNET_SET(so->so_vnet);
2607 	if (pr->pr_usrreqs->pru_flush != NULL)
2608 		(*pr->pr_usrreqs->pru_flush)(so, how);
2609 	if (how != SHUT_WR)
2610 		sorflush(so);
2611 	if (how != SHUT_RD) {
2612 		error = (*pr->pr_usrreqs->pru_shutdown)(so);
2613 		wakeup(&so->so_timeo);
2614 		CURVNET_RESTORE();
2615 		return ((error == 0 && soerror_enotconn) ? ENOTCONN : error);
2616 	}
2617 	wakeup(&so->so_timeo);
2618 	CURVNET_RESTORE();
2619 
2620 done:
2621 	return (soerror_enotconn ? ENOTCONN : 0);
2622 }
2623 
2624 void
2625 sorflush(struct socket *so)
2626 {
2627 	struct sockbuf *sb = &so->so_rcv;
2628 	struct protosw *pr = so->so_proto;
2629 	struct socket aso;
2630 
2631 	VNET_SO_ASSERT(so);
2632 
2633 	/*
2634 	 * In order to avoid calling dom_dispose with the socket buffer mutex
2635 	 * held, and in order to generally avoid holding the lock for a long
2636 	 * time, we make a copy of the socket buffer and clear the original
2637 	 * (except locks, state).  The new socket buffer copy won't have
2638 	 * initialized locks so we can only call routines that won't use or
2639 	 * assert those locks.
2640 	 *
2641 	 * Dislodge threads currently blocked in receive and wait to acquire
2642 	 * a lock against other simultaneous readers before clearing the
2643 	 * socket buffer.  Don't let our acquire be interrupted by a signal
2644 	 * despite any existing socket disposition on interruptable waiting.
2645 	 */
2646 	socantrcvmore(so);
2647 	(void) sblock(sb, SBL_WAIT | SBL_NOINTR);
2648 
2649 	/*
2650 	 * Invalidate/clear most of the sockbuf structure, but leave selinfo
2651 	 * and mutex data unchanged.
2652 	 */
2653 	SOCKBUF_LOCK(sb);
2654 	bzero(&aso, sizeof(aso));
2655 	aso.so_pcb = so->so_pcb;
2656 	bcopy(&sb->sb_startzero, &aso.so_rcv.sb_startzero,
2657 	    sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
2658 	bzero(&sb->sb_startzero,
2659 	    sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
2660 	SOCKBUF_UNLOCK(sb);
2661 	sbunlock(sb);
2662 
2663 	/*
2664 	 * Dispose of special rights and flush the copied socket.  Don't call
2665 	 * any unsafe routines (that rely on locks being initialized) on aso.
2666 	 */
2667 	if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose != NULL)
2668 		(*pr->pr_domain->dom_dispose)(&aso);
2669 	sbrelease_internal(&aso.so_rcv, so);
2670 }
2671 
2672 /*
2673  * Wrapper for Socket established helper hook.
2674  * Parameters: socket, context of the hook point, hook id.
2675  */
2676 static int inline
2677 hhook_run_socket(struct socket *so, void *hctx, int32_t h_id)
2678 {
2679 	struct socket_hhook_data hhook_data = {
2680 		.so = so,
2681 		.hctx = hctx,
2682 		.m = NULL,
2683 		.status = 0
2684 	};
2685 
2686 	CURVNET_SET(so->so_vnet);
2687 	HHOOKS_RUN_IF(V_socket_hhh[h_id], &hhook_data, &so->osd);
2688 	CURVNET_RESTORE();
2689 
2690 	/* Ugly but needed, since hhooks return void for now */
2691 	return (hhook_data.status);
2692 }
2693 
2694 /*
2695  * Perhaps this routine, and sooptcopyout(), below, ought to come in an
2696  * additional variant to handle the case where the option value needs to be
2697  * some kind of integer, but not a specific size.  In addition to their use
2698  * here, these functions are also called by the protocol-level pr_ctloutput()
2699  * routines.
2700  */
2701 int
2702 sooptcopyin(struct sockopt *sopt, void *buf, size_t len, size_t minlen)
2703 {
2704 	size_t	valsize;
2705 
2706 	/*
2707 	 * If the user gives us more than we wanted, we ignore it, but if we
2708 	 * don't get the minimum length the caller wants, we return EINVAL.
2709 	 * On success, sopt->sopt_valsize is set to however much we actually
2710 	 * retrieved.
2711 	 */
2712 	if ((valsize = sopt->sopt_valsize) < minlen)
2713 		return EINVAL;
2714 	if (valsize > len)
2715 		sopt->sopt_valsize = valsize = len;
2716 
2717 	if (sopt->sopt_td != NULL)
2718 		return (copyin(sopt->sopt_val, buf, valsize));
2719 
2720 	bcopy(sopt->sopt_val, buf, valsize);
2721 	return (0);
2722 }
2723 
2724 /*
2725  * Kernel version of setsockopt(2).
2726  *
2727  * XXX: optlen is size_t, not socklen_t
2728  */
2729 int
2730 so_setsockopt(struct socket *so, int level, int optname, void *optval,
2731     size_t optlen)
2732 {
2733 	struct sockopt sopt;
2734 
2735 	sopt.sopt_level = level;
2736 	sopt.sopt_name = optname;
2737 	sopt.sopt_dir = SOPT_SET;
2738 	sopt.sopt_val = optval;
2739 	sopt.sopt_valsize = optlen;
2740 	sopt.sopt_td = NULL;
2741 	return (sosetopt(so, &sopt));
2742 }
2743 
2744 int
2745 sosetopt(struct socket *so, struct sockopt *sopt)
2746 {
2747 	int	error, optval;
2748 	struct	linger l;
2749 	struct	timeval tv;
2750 	sbintime_t val;
2751 	uint32_t val32;
2752 #ifdef MAC
2753 	struct mac extmac;
2754 #endif
2755 
2756 	CURVNET_SET(so->so_vnet);
2757 	error = 0;
2758 	if (sopt->sopt_level != SOL_SOCKET) {
2759 		if (so->so_proto->pr_ctloutput != NULL)
2760 			error = (*so->so_proto->pr_ctloutput)(so, sopt);
2761 		else
2762 			error = ENOPROTOOPT;
2763 	} else {
2764 		switch (sopt->sopt_name) {
2765 		case SO_ACCEPTFILTER:
2766 			error = accept_filt_setopt(so, sopt);
2767 			if (error)
2768 				goto bad;
2769 			break;
2770 
2771 		case SO_LINGER:
2772 			error = sooptcopyin(sopt, &l, sizeof l, sizeof l);
2773 			if (error)
2774 				goto bad;
2775 
2776 			SOCK_LOCK(so);
2777 			so->so_linger = l.l_linger;
2778 			if (l.l_onoff)
2779 				so->so_options |= SO_LINGER;
2780 			else
2781 				so->so_options &= ~SO_LINGER;
2782 			SOCK_UNLOCK(so);
2783 			break;
2784 
2785 		case SO_DEBUG:
2786 		case SO_KEEPALIVE:
2787 		case SO_DONTROUTE:
2788 		case SO_USELOOPBACK:
2789 		case SO_BROADCAST:
2790 		case SO_REUSEADDR:
2791 		case SO_REUSEPORT:
2792 		case SO_REUSEPORT_LB:
2793 		case SO_OOBINLINE:
2794 		case SO_TIMESTAMP:
2795 		case SO_BINTIME:
2796 		case SO_NOSIGPIPE:
2797 		case SO_NO_DDP:
2798 		case SO_NO_OFFLOAD:
2799 			error = sooptcopyin(sopt, &optval, sizeof optval,
2800 			    sizeof optval);
2801 			if (error)
2802 				goto bad;
2803 			SOCK_LOCK(so);
2804 			if (optval)
2805 				so->so_options |= sopt->sopt_name;
2806 			else
2807 				so->so_options &= ~sopt->sopt_name;
2808 			SOCK_UNLOCK(so);
2809 			break;
2810 
2811 		case SO_SETFIB:
2812 			error = sooptcopyin(sopt, &optval, sizeof optval,
2813 			    sizeof optval);
2814 			if (error)
2815 				goto bad;
2816 
2817 			if (optval < 0 || optval >= rt_numfibs) {
2818 				error = EINVAL;
2819 				goto bad;
2820 			}
2821 			if (((so->so_proto->pr_domain->dom_family == PF_INET) ||
2822 			   (so->so_proto->pr_domain->dom_family == PF_INET6) ||
2823 			   (so->so_proto->pr_domain->dom_family == PF_ROUTE)))
2824 				so->so_fibnum = optval;
2825 			else
2826 				so->so_fibnum = 0;
2827 			break;
2828 
2829 		case SO_USER_COOKIE:
2830 			error = sooptcopyin(sopt, &val32, sizeof val32,
2831 			    sizeof val32);
2832 			if (error)
2833 				goto bad;
2834 			so->so_user_cookie = val32;
2835 			break;
2836 
2837 		case SO_SNDBUF:
2838 		case SO_RCVBUF:
2839 		case SO_SNDLOWAT:
2840 		case SO_RCVLOWAT:
2841 			error = sooptcopyin(sopt, &optval, sizeof optval,
2842 			    sizeof optval);
2843 			if (error)
2844 				goto bad;
2845 
2846 			/*
2847 			 * Values < 1 make no sense for any of these options,
2848 			 * so disallow them.
2849 			 */
2850 			if (optval < 1) {
2851 				error = EINVAL;
2852 				goto bad;
2853 			}
2854 
2855 			error = sbsetopt(so, sopt->sopt_name, optval);
2856 			break;
2857 
2858 		case SO_SNDTIMEO:
2859 		case SO_RCVTIMEO:
2860 #ifdef COMPAT_FREEBSD32
2861 			if (SV_CURPROC_FLAG(SV_ILP32)) {
2862 				struct timeval32 tv32;
2863 
2864 				error = sooptcopyin(sopt, &tv32, sizeof tv32,
2865 				    sizeof tv32);
2866 				CP(tv32, tv, tv_sec);
2867 				CP(tv32, tv, tv_usec);
2868 			} else
2869 #endif
2870 				error = sooptcopyin(sopt, &tv, sizeof tv,
2871 				    sizeof tv);
2872 			if (error)
2873 				goto bad;
2874 			if (tv.tv_sec < 0 || tv.tv_usec < 0 ||
2875 			    tv.tv_usec >= 1000000) {
2876 				error = EDOM;
2877 				goto bad;
2878 			}
2879 			if (tv.tv_sec > INT32_MAX)
2880 				val = SBT_MAX;
2881 			else
2882 				val = tvtosbt(tv);
2883 			switch (sopt->sopt_name) {
2884 			case SO_SNDTIMEO:
2885 				so->so_snd.sb_timeo = val;
2886 				break;
2887 			case SO_RCVTIMEO:
2888 				so->so_rcv.sb_timeo = val;
2889 				break;
2890 			}
2891 			break;
2892 
2893 		case SO_LABEL:
2894 #ifdef MAC
2895 			error = sooptcopyin(sopt, &extmac, sizeof extmac,
2896 			    sizeof extmac);
2897 			if (error)
2898 				goto bad;
2899 			error = mac_setsockopt_label(sopt->sopt_td->td_ucred,
2900 			    so, &extmac);
2901 #else
2902 			error = EOPNOTSUPP;
2903 #endif
2904 			break;
2905 
2906 		case SO_TS_CLOCK:
2907 			error = sooptcopyin(sopt, &optval, sizeof optval,
2908 			    sizeof optval);
2909 			if (error)
2910 				goto bad;
2911 			if (optval < 0 || optval > SO_TS_CLOCK_MAX) {
2912 				error = EINVAL;
2913 				goto bad;
2914 			}
2915 			so->so_ts_clock = optval;
2916 			break;
2917 
2918 		case SO_MAX_PACING_RATE:
2919 			error = sooptcopyin(sopt, &val32, sizeof(val32),
2920 			    sizeof(val32));
2921 			if (error)
2922 				goto bad;
2923 			so->so_max_pacing_rate = val32;
2924 			break;
2925 
2926 		default:
2927 			if (V_socket_hhh[HHOOK_SOCKET_OPT]->hhh_nhooks > 0)
2928 				error = hhook_run_socket(so, sopt,
2929 				    HHOOK_SOCKET_OPT);
2930 			else
2931 				error = ENOPROTOOPT;
2932 			break;
2933 		}
2934 		if (error == 0 && so->so_proto->pr_ctloutput != NULL)
2935 			(void)(*so->so_proto->pr_ctloutput)(so, sopt);
2936 	}
2937 bad:
2938 	CURVNET_RESTORE();
2939 	return (error);
2940 }
2941 
2942 /*
2943  * Helper routine for getsockopt.
2944  */
2945 int
2946 sooptcopyout(struct sockopt *sopt, const void *buf, size_t len)
2947 {
2948 	int	error;
2949 	size_t	valsize;
2950 
2951 	error = 0;
2952 
2953 	/*
2954 	 * Documented get behavior is that we always return a value, possibly
2955 	 * truncated to fit in the user's buffer.  Traditional behavior is
2956 	 * that we always tell the user precisely how much we copied, rather
2957 	 * than something useful like the total amount we had available for
2958 	 * her.  Note that this interface is not idempotent; the entire
2959 	 * answer must be generated ahead of time.
2960 	 */
2961 	valsize = min(len, sopt->sopt_valsize);
2962 	sopt->sopt_valsize = valsize;
2963 	if (sopt->sopt_val != NULL) {
2964 		if (sopt->sopt_td != NULL)
2965 			error = copyout(buf, sopt->sopt_val, valsize);
2966 		else
2967 			bcopy(buf, sopt->sopt_val, valsize);
2968 	}
2969 	return (error);
2970 }
2971 
2972 int
2973 sogetopt(struct socket *so, struct sockopt *sopt)
2974 {
2975 	int	error, optval;
2976 	struct	linger l;
2977 	struct	timeval tv;
2978 #ifdef MAC
2979 	struct mac extmac;
2980 #endif
2981 
2982 	CURVNET_SET(so->so_vnet);
2983 	error = 0;
2984 	if (sopt->sopt_level != SOL_SOCKET) {
2985 		if (so->so_proto->pr_ctloutput != NULL)
2986 			error = (*so->so_proto->pr_ctloutput)(so, sopt);
2987 		else
2988 			error = ENOPROTOOPT;
2989 		CURVNET_RESTORE();
2990 		return (error);
2991 	} else {
2992 		switch (sopt->sopt_name) {
2993 		case SO_ACCEPTFILTER:
2994 			error = accept_filt_getopt(so, sopt);
2995 			break;
2996 
2997 		case SO_LINGER:
2998 			SOCK_LOCK(so);
2999 			l.l_onoff = so->so_options & SO_LINGER;
3000 			l.l_linger = so->so_linger;
3001 			SOCK_UNLOCK(so);
3002 			error = sooptcopyout(sopt, &l, sizeof l);
3003 			break;
3004 
3005 		case SO_USELOOPBACK:
3006 		case SO_DONTROUTE:
3007 		case SO_DEBUG:
3008 		case SO_KEEPALIVE:
3009 		case SO_REUSEADDR:
3010 		case SO_REUSEPORT:
3011 		case SO_REUSEPORT_LB:
3012 		case SO_BROADCAST:
3013 		case SO_OOBINLINE:
3014 		case SO_ACCEPTCONN:
3015 		case SO_TIMESTAMP:
3016 		case SO_BINTIME:
3017 		case SO_NOSIGPIPE:
3018 			optval = so->so_options & sopt->sopt_name;
3019 integer:
3020 			error = sooptcopyout(sopt, &optval, sizeof optval);
3021 			break;
3022 
3023 		case SO_DOMAIN:
3024 			optval = so->so_proto->pr_domain->dom_family;
3025 			goto integer;
3026 
3027 		case SO_TYPE:
3028 			optval = so->so_type;
3029 			goto integer;
3030 
3031 		case SO_PROTOCOL:
3032 			optval = so->so_proto->pr_protocol;
3033 			goto integer;
3034 
3035 		case SO_ERROR:
3036 			SOCK_LOCK(so);
3037 			optval = so->so_error;
3038 			so->so_error = 0;
3039 			SOCK_UNLOCK(so);
3040 			goto integer;
3041 
3042 		case SO_SNDBUF:
3043 			optval = SOLISTENING(so) ? so->sol_sbsnd_hiwat :
3044 			    so->so_snd.sb_hiwat;
3045 			goto integer;
3046 
3047 		case SO_RCVBUF:
3048 			optval = SOLISTENING(so) ? so->sol_sbrcv_hiwat :
3049 			    so->so_rcv.sb_hiwat;
3050 			goto integer;
3051 
3052 		case SO_SNDLOWAT:
3053 			optval = SOLISTENING(so) ? so->sol_sbsnd_lowat :
3054 			    so->so_snd.sb_lowat;
3055 			goto integer;
3056 
3057 		case SO_RCVLOWAT:
3058 			optval = SOLISTENING(so) ? so->sol_sbrcv_lowat :
3059 			    so->so_rcv.sb_lowat;
3060 			goto integer;
3061 
3062 		case SO_SNDTIMEO:
3063 		case SO_RCVTIMEO:
3064 			tv = sbttotv(sopt->sopt_name == SO_SNDTIMEO ?
3065 			    so->so_snd.sb_timeo : so->so_rcv.sb_timeo);
3066 #ifdef COMPAT_FREEBSD32
3067 			if (SV_CURPROC_FLAG(SV_ILP32)) {
3068 				struct timeval32 tv32;
3069 
3070 				CP(tv, tv32, tv_sec);
3071 				CP(tv, tv32, tv_usec);
3072 				error = sooptcopyout(sopt, &tv32, sizeof tv32);
3073 			} else
3074 #endif
3075 				error = sooptcopyout(sopt, &tv, sizeof tv);
3076 			break;
3077 
3078 		case SO_LABEL:
3079 #ifdef MAC
3080 			error = sooptcopyin(sopt, &extmac, sizeof(extmac),
3081 			    sizeof(extmac));
3082 			if (error)
3083 				goto bad;
3084 			error = mac_getsockopt_label(sopt->sopt_td->td_ucred,
3085 			    so, &extmac);
3086 			if (error)
3087 				goto bad;
3088 			error = sooptcopyout(sopt, &extmac, sizeof extmac);
3089 #else
3090 			error = EOPNOTSUPP;
3091 #endif
3092 			break;
3093 
3094 		case SO_PEERLABEL:
3095 #ifdef MAC
3096 			error = sooptcopyin(sopt, &extmac, sizeof(extmac),
3097 			    sizeof(extmac));
3098 			if (error)
3099 				goto bad;
3100 			error = mac_getsockopt_peerlabel(
3101 			    sopt->sopt_td->td_ucred, so, &extmac);
3102 			if (error)
3103 				goto bad;
3104 			error = sooptcopyout(sopt, &extmac, sizeof extmac);
3105 #else
3106 			error = EOPNOTSUPP;
3107 #endif
3108 			break;
3109 
3110 		case SO_LISTENQLIMIT:
3111 			optval = SOLISTENING(so) ? so->sol_qlimit : 0;
3112 			goto integer;
3113 
3114 		case SO_LISTENQLEN:
3115 			optval = SOLISTENING(so) ? so->sol_qlen : 0;
3116 			goto integer;
3117 
3118 		case SO_LISTENINCQLEN:
3119 			optval = SOLISTENING(so) ? so->sol_incqlen : 0;
3120 			goto integer;
3121 
3122 		case SO_TS_CLOCK:
3123 			optval = so->so_ts_clock;
3124 			goto integer;
3125 
3126 		case SO_MAX_PACING_RATE:
3127 			optval = so->so_max_pacing_rate;
3128 			goto integer;
3129 
3130 		default:
3131 			if (V_socket_hhh[HHOOK_SOCKET_OPT]->hhh_nhooks > 0)
3132 				error = hhook_run_socket(so, sopt,
3133 				    HHOOK_SOCKET_OPT);
3134 			else
3135 				error = ENOPROTOOPT;
3136 			break;
3137 		}
3138 	}
3139 #ifdef MAC
3140 bad:
3141 #endif
3142 	CURVNET_RESTORE();
3143 	return (error);
3144 }
3145 
3146 int
3147 soopt_getm(struct sockopt *sopt, struct mbuf **mp)
3148 {
3149 	struct mbuf *m, *m_prev;
3150 	int sopt_size = sopt->sopt_valsize;
3151 
3152 	MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
3153 	if (m == NULL)
3154 		return ENOBUFS;
3155 	if (sopt_size > MLEN) {
3156 		MCLGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT);
3157 		if ((m->m_flags & M_EXT) == 0) {
3158 			m_free(m);
3159 			return ENOBUFS;
3160 		}
3161 		m->m_len = min(MCLBYTES, sopt_size);
3162 	} else {
3163 		m->m_len = min(MLEN, sopt_size);
3164 	}
3165 	sopt_size -= m->m_len;
3166 	*mp = m;
3167 	m_prev = m;
3168 
3169 	while (sopt_size) {
3170 		MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
3171 		if (m == NULL) {
3172 			m_freem(*mp);
3173 			return ENOBUFS;
3174 		}
3175 		if (sopt_size > MLEN) {
3176 			MCLGET(m, sopt->sopt_td != NULL ? M_WAITOK :
3177 			    M_NOWAIT);
3178 			if ((m->m_flags & M_EXT) == 0) {
3179 				m_freem(m);
3180 				m_freem(*mp);
3181 				return ENOBUFS;
3182 			}
3183 			m->m_len = min(MCLBYTES, sopt_size);
3184 		} else {
3185 			m->m_len = min(MLEN, sopt_size);
3186 		}
3187 		sopt_size -= m->m_len;
3188 		m_prev->m_next = m;
3189 		m_prev = m;
3190 	}
3191 	return (0);
3192 }
3193 
3194 int
3195 soopt_mcopyin(struct sockopt *sopt, struct mbuf *m)
3196 {
3197 	struct mbuf *m0 = m;
3198 
3199 	if (sopt->sopt_val == NULL)
3200 		return (0);
3201 	while (m != NULL && sopt->sopt_valsize >= m->m_len) {
3202 		if (sopt->sopt_td != NULL) {
3203 			int error;
3204 
3205 			error = copyin(sopt->sopt_val, mtod(m, char *),
3206 			    m->m_len);
3207 			if (error != 0) {
3208 				m_freem(m0);
3209 				return(error);
3210 			}
3211 		} else
3212 			bcopy(sopt->sopt_val, mtod(m, char *), m->m_len);
3213 		sopt->sopt_valsize -= m->m_len;
3214 		sopt->sopt_val = (char *)sopt->sopt_val + m->m_len;
3215 		m = m->m_next;
3216 	}
3217 	if (m != NULL) /* should be allocated enoughly at ip6_sooptmcopyin() */
3218 		panic("ip6_sooptmcopyin");
3219 	return (0);
3220 }
3221 
3222 int
3223 soopt_mcopyout(struct sockopt *sopt, struct mbuf *m)
3224 {
3225 	struct mbuf *m0 = m;
3226 	size_t valsize = 0;
3227 
3228 	if (sopt->sopt_val == NULL)
3229 		return (0);
3230 	while (m != NULL && sopt->sopt_valsize >= m->m_len) {
3231 		if (sopt->sopt_td != NULL) {
3232 			int error;
3233 
3234 			error = copyout(mtod(m, char *), sopt->sopt_val,
3235 			    m->m_len);
3236 			if (error != 0) {
3237 				m_freem(m0);
3238 				return(error);
3239 			}
3240 		} else
3241 			bcopy(mtod(m, char *), sopt->sopt_val, m->m_len);
3242 		sopt->sopt_valsize -= m->m_len;
3243 		sopt->sopt_val = (char *)sopt->sopt_val + m->m_len;
3244 		valsize += m->m_len;
3245 		m = m->m_next;
3246 	}
3247 	if (m != NULL) {
3248 		/* enough soopt buffer should be given from user-land */
3249 		m_freem(m0);
3250 		return(EINVAL);
3251 	}
3252 	sopt->sopt_valsize = valsize;
3253 	return (0);
3254 }
3255 
3256 /*
3257  * sohasoutofband(): protocol notifies socket layer of the arrival of new
3258  * out-of-band data, which will then notify socket consumers.
3259  */
3260 void
3261 sohasoutofband(struct socket *so)
3262 {
3263 
3264 	if (so->so_sigio != NULL)
3265 		pgsigio(&so->so_sigio, SIGURG, 0);
3266 	selwakeuppri(&so->so_rdsel, PSOCK);
3267 }
3268 
3269 int
3270 sopoll(struct socket *so, int events, struct ucred *active_cred,
3271     struct thread *td)
3272 {
3273 
3274 	/*
3275 	 * We do not need to set or assert curvnet as long as everyone uses
3276 	 * sopoll_generic().
3277 	 */
3278 	return (so->so_proto->pr_usrreqs->pru_sopoll(so, events, active_cred,
3279 	    td));
3280 }
3281 
3282 int
3283 sopoll_generic(struct socket *so, int events, struct ucred *active_cred,
3284     struct thread *td)
3285 {
3286 	int revents;
3287 
3288 	SOCK_LOCK(so);
3289 	if (SOLISTENING(so)) {
3290 		if (!(events & (POLLIN | POLLRDNORM)))
3291 			revents = 0;
3292 		else if (!TAILQ_EMPTY(&so->sol_comp))
3293 			revents = events & (POLLIN | POLLRDNORM);
3294 		else if ((events & POLLINIGNEOF) == 0 && so->so_error)
3295 			revents = (events & (POLLIN | POLLRDNORM)) | POLLHUP;
3296 		else {
3297 			selrecord(td, &so->so_rdsel);
3298 			revents = 0;
3299 		}
3300 	} else {
3301 		revents = 0;
3302 		SOCKBUF_LOCK(&so->so_snd);
3303 		SOCKBUF_LOCK(&so->so_rcv);
3304 		if (events & (POLLIN | POLLRDNORM))
3305 			if (soreadabledata(so))
3306 				revents |= events & (POLLIN | POLLRDNORM);
3307 		if (events & (POLLOUT | POLLWRNORM))
3308 			if (sowriteable(so))
3309 				revents |= events & (POLLOUT | POLLWRNORM);
3310 		if (events & (POLLPRI | POLLRDBAND))
3311 			if (so->so_oobmark ||
3312 			    (so->so_rcv.sb_state & SBS_RCVATMARK))
3313 				revents |= events & (POLLPRI | POLLRDBAND);
3314 		if ((events & POLLINIGNEOF) == 0) {
3315 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
3316 				revents |= events & (POLLIN | POLLRDNORM);
3317 				if (so->so_snd.sb_state & SBS_CANTSENDMORE)
3318 					revents |= POLLHUP;
3319 			}
3320 		}
3321 		if (revents == 0) {
3322 			if (events &
3323 			    (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) {
3324 				selrecord(td, &so->so_rdsel);
3325 				so->so_rcv.sb_flags |= SB_SEL;
3326 			}
3327 			if (events & (POLLOUT | POLLWRNORM)) {
3328 				selrecord(td, &so->so_wrsel);
3329 				so->so_snd.sb_flags |= SB_SEL;
3330 			}
3331 		}
3332 		SOCKBUF_UNLOCK(&so->so_rcv);
3333 		SOCKBUF_UNLOCK(&so->so_snd);
3334 	}
3335 	SOCK_UNLOCK(so);
3336 	return (revents);
3337 }
3338 
3339 int
3340 soo_kqfilter(struct file *fp, struct knote *kn)
3341 {
3342 	struct socket *so = kn->kn_fp->f_data;
3343 	struct sockbuf *sb;
3344 	struct knlist *knl;
3345 
3346 	switch (kn->kn_filter) {
3347 	case EVFILT_READ:
3348 		kn->kn_fop = &soread_filtops;
3349 		knl = &so->so_rdsel.si_note;
3350 		sb = &so->so_rcv;
3351 		break;
3352 	case EVFILT_WRITE:
3353 		kn->kn_fop = &sowrite_filtops;
3354 		knl = &so->so_wrsel.si_note;
3355 		sb = &so->so_snd;
3356 		break;
3357 	case EVFILT_EMPTY:
3358 		kn->kn_fop = &soempty_filtops;
3359 		knl = &so->so_wrsel.si_note;
3360 		sb = &so->so_snd;
3361 		break;
3362 	default:
3363 		return (EINVAL);
3364 	}
3365 
3366 	SOCK_LOCK(so);
3367 	if (SOLISTENING(so)) {
3368 		knlist_add(knl, kn, 1);
3369 	} else {
3370 		SOCKBUF_LOCK(sb);
3371 		knlist_add(knl, kn, 1);
3372 		sb->sb_flags |= SB_KNOTE;
3373 		SOCKBUF_UNLOCK(sb);
3374 	}
3375 	SOCK_UNLOCK(so);
3376 	return (0);
3377 }
3378 
3379 /*
3380  * Some routines that return EOPNOTSUPP for entry points that are not
3381  * supported by a protocol.  Fill in as needed.
3382  */
3383 int
3384 pru_accept_notsupp(struct socket *so, struct sockaddr **nam)
3385 {
3386 
3387 	return EOPNOTSUPP;
3388 }
3389 
3390 int
3391 pru_aio_queue_notsupp(struct socket *so, struct kaiocb *job)
3392 {
3393 
3394 	return EOPNOTSUPP;
3395 }
3396 
3397 int
3398 pru_attach_notsupp(struct socket *so, int proto, struct thread *td)
3399 {
3400 
3401 	return EOPNOTSUPP;
3402 }
3403 
3404 int
3405 pru_bind_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
3406 {
3407 
3408 	return EOPNOTSUPP;
3409 }
3410 
3411 int
3412 pru_bindat_notsupp(int fd, struct socket *so, struct sockaddr *nam,
3413     struct thread *td)
3414 {
3415 
3416 	return EOPNOTSUPP;
3417 }
3418 
3419 int
3420 pru_connect_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
3421 {
3422 
3423 	return EOPNOTSUPP;
3424 }
3425 
3426 int
3427 pru_connectat_notsupp(int fd, struct socket *so, struct sockaddr *nam,
3428     struct thread *td)
3429 {
3430 
3431 	return EOPNOTSUPP;
3432 }
3433 
3434 int
3435 pru_connect2_notsupp(struct socket *so1, struct socket *so2)
3436 {
3437 
3438 	return EOPNOTSUPP;
3439 }
3440 
3441 int
3442 pru_control_notsupp(struct socket *so, u_long cmd, caddr_t data,
3443     struct ifnet *ifp, struct thread *td)
3444 {
3445 
3446 	return EOPNOTSUPP;
3447 }
3448 
3449 int
3450 pru_disconnect_notsupp(struct socket *so)
3451 {
3452 
3453 	return EOPNOTSUPP;
3454 }
3455 
3456 int
3457 pru_listen_notsupp(struct socket *so, int backlog, struct thread *td)
3458 {
3459 
3460 	return EOPNOTSUPP;
3461 }
3462 
3463 int
3464 pru_peeraddr_notsupp(struct socket *so, struct sockaddr **nam)
3465 {
3466 
3467 	return EOPNOTSUPP;
3468 }
3469 
3470 int
3471 pru_rcvd_notsupp(struct socket *so, int flags)
3472 {
3473 
3474 	return EOPNOTSUPP;
3475 }
3476 
3477 int
3478 pru_rcvoob_notsupp(struct socket *so, struct mbuf *m, int flags)
3479 {
3480 
3481 	return EOPNOTSUPP;
3482 }
3483 
3484 int
3485 pru_send_notsupp(struct socket *so, int flags, struct mbuf *m,
3486     struct sockaddr *addr, struct mbuf *control, struct thread *td)
3487 {
3488 
3489 	return EOPNOTSUPP;
3490 }
3491 
3492 int
3493 pru_ready_notsupp(struct socket *so, struct mbuf *m, int count)
3494 {
3495 
3496 	return (EOPNOTSUPP);
3497 }
3498 
3499 /*
3500  * This isn't really a ``null'' operation, but it's the default one and
3501  * doesn't do anything destructive.
3502  */
3503 int
3504 pru_sense_null(struct socket *so, struct stat *sb)
3505 {
3506 
3507 	sb->st_blksize = so->so_snd.sb_hiwat;
3508 	return 0;
3509 }
3510 
3511 int
3512 pru_shutdown_notsupp(struct socket *so)
3513 {
3514 
3515 	return EOPNOTSUPP;
3516 }
3517 
3518 int
3519 pru_sockaddr_notsupp(struct socket *so, struct sockaddr **nam)
3520 {
3521 
3522 	return EOPNOTSUPP;
3523 }
3524 
3525 int
3526 pru_sosend_notsupp(struct socket *so, struct sockaddr *addr, struct uio *uio,
3527     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
3528 {
3529 
3530 	return EOPNOTSUPP;
3531 }
3532 
3533 int
3534 pru_soreceive_notsupp(struct socket *so, struct sockaddr **paddr,
3535     struct uio *uio, struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
3536 {
3537 
3538 	return EOPNOTSUPP;
3539 }
3540 
3541 int
3542 pru_sopoll_notsupp(struct socket *so, int events, struct ucred *cred,
3543     struct thread *td)
3544 {
3545 
3546 	return EOPNOTSUPP;
3547 }
3548 
3549 static void
3550 filt_sordetach(struct knote *kn)
3551 {
3552 	struct socket *so = kn->kn_fp->f_data;
3553 
3554 	so_rdknl_lock(so);
3555 	knlist_remove(&so->so_rdsel.si_note, kn, 1);
3556 	if (!SOLISTENING(so) && knlist_empty(&so->so_rdsel.si_note))
3557 		so->so_rcv.sb_flags &= ~SB_KNOTE;
3558 	so_rdknl_unlock(so);
3559 }
3560 
3561 /*ARGSUSED*/
3562 static int
3563 filt_soread(struct knote *kn, long hint)
3564 {
3565 	struct socket *so;
3566 
3567 	so = kn->kn_fp->f_data;
3568 
3569 	if (SOLISTENING(so)) {
3570 		SOCK_LOCK_ASSERT(so);
3571 		kn->kn_data = so->sol_qlen;
3572 		if (so->so_error) {
3573 			kn->kn_flags |= EV_EOF;
3574 			kn->kn_fflags = so->so_error;
3575 			return (1);
3576 		}
3577 		return (!TAILQ_EMPTY(&so->sol_comp));
3578 	}
3579 
3580 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
3581 
3582 	kn->kn_data = sbavail(&so->so_rcv) - so->so_rcv.sb_ctl;
3583 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
3584 		kn->kn_flags |= EV_EOF;
3585 		kn->kn_fflags = so->so_error;
3586 		return (1);
3587 	} else if (so->so_error)	/* temporary udp error */
3588 		return (1);
3589 
3590 	if (kn->kn_sfflags & NOTE_LOWAT) {
3591 		if (kn->kn_data >= kn->kn_sdata)
3592 			return (1);
3593 	} else if (sbavail(&so->so_rcv) >= so->so_rcv.sb_lowat)
3594 		return (1);
3595 
3596 	/* This hook returning non-zero indicates an event, not error */
3597 	return (hhook_run_socket(so, NULL, HHOOK_FILT_SOREAD));
3598 }
3599 
3600 static void
3601 filt_sowdetach(struct knote *kn)
3602 {
3603 	struct socket *so = kn->kn_fp->f_data;
3604 
3605 	so_wrknl_lock(so);
3606 	knlist_remove(&so->so_wrsel.si_note, kn, 1);
3607 	if (!SOLISTENING(so) && knlist_empty(&so->so_wrsel.si_note))
3608 		so->so_snd.sb_flags &= ~SB_KNOTE;
3609 	so_wrknl_unlock(so);
3610 }
3611 
3612 /*ARGSUSED*/
3613 static int
3614 filt_sowrite(struct knote *kn, long hint)
3615 {
3616 	struct socket *so;
3617 
3618 	so = kn->kn_fp->f_data;
3619 
3620 	if (SOLISTENING(so))
3621 		return (0);
3622 
3623 	SOCKBUF_LOCK_ASSERT(&so->so_snd);
3624 	kn->kn_data = sbspace(&so->so_snd);
3625 
3626 	hhook_run_socket(so, kn, HHOOK_FILT_SOWRITE);
3627 
3628 	if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
3629 		kn->kn_flags |= EV_EOF;
3630 		kn->kn_fflags = so->so_error;
3631 		return (1);
3632 	} else if (so->so_error)	/* temporary udp error */
3633 		return (1);
3634 	else if (((so->so_state & SS_ISCONNECTED) == 0) &&
3635 	    (so->so_proto->pr_flags & PR_CONNREQUIRED))
3636 		return (0);
3637 	else if (kn->kn_sfflags & NOTE_LOWAT)
3638 		return (kn->kn_data >= kn->kn_sdata);
3639 	else
3640 		return (kn->kn_data >= so->so_snd.sb_lowat);
3641 }
3642 
3643 static int
3644 filt_soempty(struct knote *kn, long hint)
3645 {
3646 	struct socket *so;
3647 
3648 	so = kn->kn_fp->f_data;
3649 
3650 	if (SOLISTENING(so))
3651 		return (1);
3652 
3653 	SOCKBUF_LOCK_ASSERT(&so->so_snd);
3654 	kn->kn_data = sbused(&so->so_snd);
3655 
3656 	if (kn->kn_data == 0)
3657 		return (1);
3658 	else
3659 		return (0);
3660 }
3661 
3662 int
3663 socheckuid(struct socket *so, uid_t uid)
3664 {
3665 
3666 	if (so == NULL)
3667 		return (EPERM);
3668 	if (so->so_cred->cr_uid != uid)
3669 		return (EPERM);
3670 	return (0);
3671 }
3672 
3673 /*
3674  * These functions are used by protocols to notify the socket layer (and its
3675  * consumers) of state changes in the sockets driven by protocol-side events.
3676  */
3677 
3678 /*
3679  * Procedures to manipulate state flags of socket and do appropriate wakeups.
3680  *
3681  * Normal sequence from the active (originating) side is that
3682  * soisconnecting() is called during processing of connect() call, resulting
3683  * in an eventual call to soisconnected() if/when the connection is
3684  * established.  When the connection is torn down soisdisconnecting() is
3685  * called during processing of disconnect() call, and soisdisconnected() is
3686  * called when the connection to the peer is totally severed.  The semantics
3687  * of these routines are such that connectionless protocols can call
3688  * soisconnected() and soisdisconnected() only, bypassing the in-progress
3689  * calls when setting up a ``connection'' takes no time.
3690  *
3691  * From the passive side, a socket is created with two queues of sockets:
3692  * so_incomp for connections in progress and so_comp for connections already
3693  * made and awaiting user acceptance.  As a protocol is preparing incoming
3694  * connections, it creates a socket structure queued on so_incomp by calling
3695  * sonewconn().  When the connection is established, soisconnected() is
3696  * called, and transfers the socket structure to so_comp, making it available
3697  * to accept().
3698  *
3699  * If a socket is closed with sockets on either so_incomp or so_comp, these
3700  * sockets are dropped.
3701  *
3702  * If higher-level protocols are implemented in the kernel, the wakeups done
3703  * here will sometimes cause software-interrupt process scheduling.
3704  */
3705 void
3706 soisconnecting(struct socket *so)
3707 {
3708 
3709 	SOCK_LOCK(so);
3710 	so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
3711 	so->so_state |= SS_ISCONNECTING;
3712 	SOCK_UNLOCK(so);
3713 }
3714 
3715 void
3716 soisconnected(struct socket *so)
3717 {
3718 
3719 	SOCK_LOCK(so);
3720 	so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
3721 	so->so_state |= SS_ISCONNECTED;
3722 
3723 	if (so->so_qstate == SQ_INCOMP) {
3724 		struct socket *head = so->so_listen;
3725 		int ret;
3726 
3727 		KASSERT(head, ("%s: so %p on incomp of NULL", __func__, so));
3728 		/*
3729 		 * Promoting a socket from incomplete queue to complete, we
3730 		 * need to go through reverse order of locking.  We first do
3731 		 * trylock, and if that doesn't succeed, we go the hard way
3732 		 * leaving a reference and rechecking consistency after proper
3733 		 * locking.
3734 		 */
3735 		if (__predict_false(SOLISTEN_TRYLOCK(head) == 0)) {
3736 			soref(head);
3737 			SOCK_UNLOCK(so);
3738 			SOLISTEN_LOCK(head);
3739 			SOCK_LOCK(so);
3740 			if (__predict_false(head != so->so_listen)) {
3741 				/*
3742 				 * The socket went off the listen queue,
3743 				 * should be lost race to close(2) of sol.
3744 				 * The socket is about to soabort().
3745 				 */
3746 				SOCK_UNLOCK(so);
3747 				sorele(head);
3748 				return;
3749 			}
3750 			/* Not the last one, as so holds a ref. */
3751 			refcount_release(&head->so_count);
3752 		}
3753 again:
3754 		if ((so->so_options & SO_ACCEPTFILTER) == 0) {
3755 			TAILQ_REMOVE(&head->sol_incomp, so, so_list);
3756 			head->sol_incqlen--;
3757 			TAILQ_INSERT_TAIL(&head->sol_comp, so, so_list);
3758 			head->sol_qlen++;
3759 			so->so_qstate = SQ_COMP;
3760 			SOCK_UNLOCK(so);
3761 			solisten_wakeup(head);	/* unlocks */
3762 		} else {
3763 			SOCKBUF_LOCK(&so->so_rcv);
3764 			soupcall_set(so, SO_RCV,
3765 			    head->sol_accept_filter->accf_callback,
3766 			    head->sol_accept_filter_arg);
3767 			so->so_options &= ~SO_ACCEPTFILTER;
3768 			ret = head->sol_accept_filter->accf_callback(so,
3769 			    head->sol_accept_filter_arg, M_NOWAIT);
3770 			if (ret == SU_ISCONNECTED) {
3771 				soupcall_clear(so, SO_RCV);
3772 				SOCKBUF_UNLOCK(&so->so_rcv);
3773 				goto again;
3774 			}
3775 			SOCKBUF_UNLOCK(&so->so_rcv);
3776 			SOCK_UNLOCK(so);
3777 			SOLISTEN_UNLOCK(head);
3778 		}
3779 		return;
3780 	}
3781 	SOCK_UNLOCK(so);
3782 	wakeup(&so->so_timeo);
3783 	sorwakeup(so);
3784 	sowwakeup(so);
3785 }
3786 
3787 void
3788 soisdisconnecting(struct socket *so)
3789 {
3790 
3791 	SOCK_LOCK(so);
3792 	so->so_state &= ~SS_ISCONNECTING;
3793 	so->so_state |= SS_ISDISCONNECTING;
3794 
3795 	if (!SOLISTENING(so)) {
3796 		SOCKBUF_LOCK(&so->so_rcv);
3797 		socantrcvmore_locked(so);
3798 		SOCKBUF_LOCK(&so->so_snd);
3799 		socantsendmore_locked(so);
3800 	}
3801 	SOCK_UNLOCK(so);
3802 	wakeup(&so->so_timeo);
3803 }
3804 
3805 void
3806 soisdisconnected(struct socket *so)
3807 {
3808 
3809 	SOCK_LOCK(so);
3810 	so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
3811 	so->so_state |= SS_ISDISCONNECTED;
3812 
3813 	if (!SOLISTENING(so)) {
3814 		SOCK_UNLOCK(so);
3815 		SOCKBUF_LOCK(&so->so_rcv);
3816 		socantrcvmore_locked(so);
3817 		SOCKBUF_LOCK(&so->so_snd);
3818 		sbdrop_locked(&so->so_snd, sbused(&so->so_snd));
3819 		socantsendmore_locked(so);
3820 	} else
3821 		SOCK_UNLOCK(so);
3822 	wakeup(&so->so_timeo);
3823 }
3824 
3825 /*
3826  * Make a copy of a sockaddr in a malloced buffer of type M_SONAME.
3827  */
3828 struct sockaddr *
3829 sodupsockaddr(const struct sockaddr *sa, int mflags)
3830 {
3831 	struct sockaddr *sa2;
3832 
3833 	sa2 = malloc(sa->sa_len, M_SONAME, mflags);
3834 	if (sa2)
3835 		bcopy(sa, sa2, sa->sa_len);
3836 	return sa2;
3837 }
3838 
3839 /*
3840  * Register per-socket destructor.
3841  */
3842 void
3843 sodtor_set(struct socket *so, so_dtor_t *func)
3844 {
3845 
3846 	SOCK_LOCK_ASSERT(so);
3847 	so->so_dtor = func;
3848 }
3849 
3850 /*
3851  * Register per-socket buffer upcalls.
3852  */
3853 void
3854 soupcall_set(struct socket *so, int which, so_upcall_t func, void *arg)
3855 {
3856 	struct sockbuf *sb;
3857 
3858 	KASSERT(!SOLISTENING(so), ("%s: so %p listening", __func__, so));
3859 
3860 	switch (which) {
3861 	case SO_RCV:
3862 		sb = &so->so_rcv;
3863 		break;
3864 	case SO_SND:
3865 		sb = &so->so_snd;
3866 		break;
3867 	default:
3868 		panic("soupcall_set: bad which");
3869 	}
3870 	SOCKBUF_LOCK_ASSERT(sb);
3871 	sb->sb_upcall = func;
3872 	sb->sb_upcallarg = arg;
3873 	sb->sb_flags |= SB_UPCALL;
3874 }
3875 
3876 void
3877 soupcall_clear(struct socket *so, int which)
3878 {
3879 	struct sockbuf *sb;
3880 
3881 	KASSERT(!SOLISTENING(so), ("%s: so %p listening", __func__, so));
3882 
3883 	switch (which) {
3884 	case SO_RCV:
3885 		sb = &so->so_rcv;
3886 		break;
3887 	case SO_SND:
3888 		sb = &so->so_snd;
3889 		break;
3890 	default:
3891 		panic("soupcall_clear: bad which");
3892 	}
3893 	SOCKBUF_LOCK_ASSERT(sb);
3894 	KASSERT(sb->sb_upcall != NULL,
3895 	    ("%s: so %p no upcall to clear", __func__, so));
3896 	sb->sb_upcall = NULL;
3897 	sb->sb_upcallarg = NULL;
3898 	sb->sb_flags &= ~SB_UPCALL;
3899 }
3900 
3901 void
3902 solisten_upcall_set(struct socket *so, so_upcall_t func, void *arg)
3903 {
3904 
3905 	SOLISTEN_LOCK_ASSERT(so);
3906 	so->sol_upcall = func;
3907 	so->sol_upcallarg = arg;
3908 }
3909 
3910 static void
3911 so_rdknl_lock(void *arg)
3912 {
3913 	struct socket *so = arg;
3914 
3915 	if (SOLISTENING(so))
3916 		SOCK_LOCK(so);
3917 	else
3918 		SOCKBUF_LOCK(&so->so_rcv);
3919 }
3920 
3921 static void
3922 so_rdknl_unlock(void *arg)
3923 {
3924 	struct socket *so = arg;
3925 
3926 	if (SOLISTENING(so))
3927 		SOCK_UNLOCK(so);
3928 	else
3929 		SOCKBUF_UNLOCK(&so->so_rcv);
3930 }
3931 
3932 static void
3933 so_rdknl_assert_locked(void *arg)
3934 {
3935 	struct socket *so = arg;
3936 
3937 	if (SOLISTENING(so))
3938 		SOCK_LOCK_ASSERT(so);
3939 	else
3940 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
3941 }
3942 
3943 static void
3944 so_rdknl_assert_unlocked(void *arg)
3945 {
3946 	struct socket *so = arg;
3947 
3948 	if (SOLISTENING(so))
3949 		SOCK_UNLOCK_ASSERT(so);
3950 	else
3951 		SOCKBUF_UNLOCK_ASSERT(&so->so_rcv);
3952 }
3953 
3954 static void
3955 so_wrknl_lock(void *arg)
3956 {
3957 	struct socket *so = arg;
3958 
3959 	if (SOLISTENING(so))
3960 		SOCK_LOCK(so);
3961 	else
3962 		SOCKBUF_LOCK(&so->so_snd);
3963 }
3964 
3965 static void
3966 so_wrknl_unlock(void *arg)
3967 {
3968 	struct socket *so = arg;
3969 
3970 	if (SOLISTENING(so))
3971 		SOCK_UNLOCK(so);
3972 	else
3973 		SOCKBUF_UNLOCK(&so->so_snd);
3974 }
3975 
3976 static void
3977 so_wrknl_assert_locked(void *arg)
3978 {
3979 	struct socket *so = arg;
3980 
3981 	if (SOLISTENING(so))
3982 		SOCK_LOCK_ASSERT(so);
3983 	else
3984 		SOCKBUF_LOCK_ASSERT(&so->so_snd);
3985 }
3986 
3987 static void
3988 so_wrknl_assert_unlocked(void *arg)
3989 {
3990 	struct socket *so = arg;
3991 
3992 	if (SOLISTENING(so))
3993 		SOCK_UNLOCK_ASSERT(so);
3994 	else
3995 		SOCKBUF_UNLOCK_ASSERT(&so->so_snd);
3996 }
3997 
3998 /*
3999  * Create an external-format (``xsocket'') structure using the information in
4000  * the kernel-format socket structure pointed to by so.  This is done to
4001  * reduce the spew of irrelevant information over this interface, to isolate
4002  * user code from changes in the kernel structure, and potentially to provide
4003  * information-hiding if we decide that some of this information should be
4004  * hidden from users.
4005  */
4006 void
4007 sotoxsocket(struct socket *so, struct xsocket *xso)
4008 {
4009 
4010 	bzero(xso, sizeof(*xso));
4011 	xso->xso_len = sizeof *xso;
4012 	xso->xso_so = (uintptr_t)so;
4013 	xso->so_type = so->so_type;
4014 	xso->so_options = so->so_options;
4015 	xso->so_linger = so->so_linger;
4016 	xso->so_state = so->so_state;
4017 	xso->so_pcb = (uintptr_t)so->so_pcb;
4018 	xso->xso_protocol = so->so_proto->pr_protocol;
4019 	xso->xso_family = so->so_proto->pr_domain->dom_family;
4020 	xso->so_timeo = so->so_timeo;
4021 	xso->so_error = so->so_error;
4022 	xso->so_uid = so->so_cred->cr_uid;
4023 	xso->so_pgid = so->so_sigio ? so->so_sigio->sio_pgid : 0;
4024 	if (SOLISTENING(so)) {
4025 		xso->so_qlen = so->sol_qlen;
4026 		xso->so_incqlen = so->sol_incqlen;
4027 		xso->so_qlimit = so->sol_qlimit;
4028 		xso->so_oobmark = 0;
4029 	} else {
4030 		xso->so_state |= so->so_qstate;
4031 		xso->so_qlen = xso->so_incqlen = xso->so_qlimit = 0;
4032 		xso->so_oobmark = so->so_oobmark;
4033 		sbtoxsockbuf(&so->so_snd, &xso->so_snd);
4034 		sbtoxsockbuf(&so->so_rcv, &xso->so_rcv);
4035 	}
4036 }
4037 
4038 struct sockbuf *
4039 so_sockbuf_rcv(struct socket *so)
4040 {
4041 
4042 	return (&so->so_rcv);
4043 }
4044 
4045 struct sockbuf *
4046 so_sockbuf_snd(struct socket *so)
4047 {
4048 
4049 	return (&so->so_snd);
4050 }
4051 
4052 int
4053 so_state_get(const struct socket *so)
4054 {
4055 
4056 	return (so->so_state);
4057 }
4058 
4059 void
4060 so_state_set(struct socket *so, int val)
4061 {
4062 
4063 	so->so_state = val;
4064 }
4065 
4066 int
4067 so_options_get(const struct socket *so)
4068 {
4069 
4070 	return (so->so_options);
4071 }
4072 
4073 void
4074 so_options_set(struct socket *so, int val)
4075 {
4076 
4077 	so->so_options = val;
4078 }
4079 
4080 int
4081 so_error_get(const struct socket *so)
4082 {
4083 
4084 	return (so->so_error);
4085 }
4086 
4087 void
4088 so_error_set(struct socket *so, int val)
4089 {
4090 
4091 	so->so_error = val;
4092 }
4093 
4094 int
4095 so_linger_get(const struct socket *so)
4096 {
4097 
4098 	return (so->so_linger);
4099 }
4100 
4101 void
4102 so_linger_set(struct socket *so, int val)
4103 {
4104 
4105 	so->so_linger = val;
4106 }
4107 
4108 struct protosw *
4109 so_protosw_get(const struct socket *so)
4110 {
4111 
4112 	return (so->so_proto);
4113 }
4114 
4115 void
4116 so_protosw_set(struct socket *so, struct protosw *val)
4117 {
4118 
4119 	so->so_proto = val;
4120 }
4121 
4122 void
4123 so_sorwakeup(struct socket *so)
4124 {
4125 
4126 	sorwakeup(so);
4127 }
4128 
4129 void
4130 so_sowwakeup(struct socket *so)
4131 {
4132 
4133 	sowwakeup(so);
4134 }
4135 
4136 void
4137 so_sorwakeup_locked(struct socket *so)
4138 {
4139 
4140 	sorwakeup_locked(so);
4141 }
4142 
4143 void
4144 so_sowwakeup_locked(struct socket *so)
4145 {
4146 
4147 	sowwakeup_locked(so);
4148 }
4149 
4150 void
4151 so_lock(struct socket *so)
4152 {
4153 
4154 	SOCK_LOCK(so);
4155 }
4156 
4157 void
4158 so_unlock(struct socket *so)
4159 {
4160 
4161 	SOCK_UNLOCK(so);
4162 }
4163