xref: /freebsd/sys/kern/uipc_socket.c (revision c99b67a7947ea215f9c1d44ec022680e98920cd1)
1 /*-
2  * Copyright (c) 1982, 1986, 1988, 1990, 1993
3  *	The Regents of the University of California.
4  * Copyright (c) 2004 The FreeBSD Foundation
5  * Copyright (c) 2004-2008 Robert N. M. Watson
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)uipc_socket.c	8.3 (Berkeley) 4/15/94
33  */
34 
35 /*
36  * Comments on the socket life cycle:
37  *
38  * soalloc() sets of socket layer state for a socket, called only by
39  * socreate() and sonewconn().  Socket layer private.
40  *
41  * sodealloc() tears down socket layer state for a socket, called only by
42  * sofree() and sonewconn().  Socket layer private.
43  *
44  * pru_attach() associates protocol layer state with an allocated socket;
45  * called only once, may fail, aborting socket allocation.  This is called
46  * from socreate() and sonewconn().  Socket layer private.
47  *
48  * pru_detach() disassociates protocol layer state from an attached socket,
49  * and will be called exactly once for sockets in which pru_attach() has
50  * been successfully called.  If pru_attach() returned an error,
51  * pru_detach() will not be called.  Socket layer private.
52  *
53  * pru_abort() and pru_close() notify the protocol layer that the last
54  * consumer of a socket is starting to tear down the socket, and that the
55  * protocol should terminate the connection.  Historically, pru_abort() also
56  * detached protocol state from the socket state, but this is no longer the
57  * case.
58  *
59  * socreate() creates a socket and attaches protocol state.  This is a public
60  * interface that may be used by socket layer consumers to create new
61  * sockets.
62  *
63  * sonewconn() creates a socket and attaches protocol state.  This is a
64  * public interface  that may be used by protocols to create new sockets when
65  * a new connection is received and will be available for accept() on a
66  * listen socket.
67  *
68  * soclose() destroys a socket after possibly waiting for it to disconnect.
69  * This is a public interface that socket consumers should use to close and
70  * release a socket when done with it.
71  *
72  * soabort() destroys a socket without waiting for it to disconnect (used
73  * only for incoming connections that are already partially or fully
74  * connected).  This is used internally by the socket layer when clearing
75  * listen socket queues (due to overflow or close on the listen socket), but
76  * is also a public interface protocols may use to abort connections in
77  * their incomplete listen queues should they no longer be required.  Sockets
78  * placed in completed connection listen queues should not be aborted for
79  * reasons described in the comment above the soclose() implementation.  This
80  * is not a general purpose close routine, and except in the specific
81  * circumstances described here, should not be used.
82  *
83  * sofree() will free a socket and its protocol state if all references on
84  * the socket have been released, and is the public interface to attempt to
85  * free a socket when a reference is removed.  This is a socket layer private
86  * interface.
87  *
88  * NOTE: In addition to socreate() and soclose(), which provide a single
89  * socket reference to the consumer to be managed as required, there are two
90  * calls to explicitly manage socket references, soref(), and sorele().
91  * Currently, these are generally required only when transitioning a socket
92  * from a listen queue to a file descriptor, in order to prevent garbage
93  * collection of the socket at an untimely moment.  For a number of reasons,
94  * these interfaces are not preferred, and should be avoided.
95  *
96  * NOTE: With regard to VNETs the general rule is that callers do not set
97  * curvnet. Exceptions to this rule include soabort(), sodisconnect(),
98  * sofree() (and with that sorele(), sotryfree()), as well as sonewconn()
99  * and sorflush(), which are usually called from a pre-set VNET context.
100  * sopoll() currently does not need a VNET context to be set.
101  */
102 
103 #include <sys/cdefs.h>
104 __FBSDID("$FreeBSD$");
105 
106 #include "opt_inet.h"
107 #include "opt_inet6.h"
108 #include "opt_compat.h"
109 #include "opt_sctp.h"
110 
111 #include <sys/param.h>
112 #include <sys/systm.h>
113 #include <sys/fcntl.h>
114 #include <sys/limits.h>
115 #include <sys/lock.h>
116 #include <sys/mac.h>
117 #include <sys/malloc.h>
118 #include <sys/mbuf.h>
119 #include <sys/mutex.h>
120 #include <sys/domain.h>
121 #include <sys/file.h>			/* for struct knote */
122 #include <sys/hhook.h>
123 #include <sys/kernel.h>
124 #include <sys/khelp.h>
125 #include <sys/event.h>
126 #include <sys/eventhandler.h>
127 #include <sys/poll.h>
128 #include <sys/proc.h>
129 #include <sys/protosw.h>
130 #include <sys/socket.h>
131 #include <sys/socketvar.h>
132 #include <sys/resourcevar.h>
133 #include <net/route.h>
134 #include <sys/signalvar.h>
135 #include <sys/stat.h>
136 #include <sys/sx.h>
137 #include <sys/sysctl.h>
138 #include <sys/taskqueue.h>
139 #include <sys/uio.h>
140 #include <sys/jail.h>
141 #include <sys/syslog.h>
142 #include <netinet/in.h>
143 
144 #include <net/vnet.h>
145 
146 #include <security/mac/mac_framework.h>
147 
148 #include <vm/uma.h>
149 
150 #ifdef COMPAT_FREEBSD32
151 #include <sys/mount.h>
152 #include <sys/sysent.h>
153 #include <compat/freebsd32/freebsd32.h>
154 #endif
155 
156 static int	soreceive_rcvoob(struct socket *so, struct uio *uio,
157 		    int flags);
158 static void	so_rdknl_lock(void *);
159 static void	so_rdknl_unlock(void *);
160 static void	so_rdknl_assert_locked(void *);
161 static void	so_rdknl_assert_unlocked(void *);
162 static void	so_wrknl_lock(void *);
163 static void	so_wrknl_unlock(void *);
164 static void	so_wrknl_assert_locked(void *);
165 static void	so_wrknl_assert_unlocked(void *);
166 
167 static void	filt_sordetach(struct knote *kn);
168 static int	filt_soread(struct knote *kn, long hint);
169 static void	filt_sowdetach(struct knote *kn);
170 static int	filt_sowrite(struct knote *kn, long hint);
171 static int	filt_soempty(struct knote *kn, long hint);
172 static int inline hhook_run_socket(struct socket *so, void *hctx, int32_t h_id);
173 fo_kqfilter_t	soo_kqfilter;
174 
175 static struct filterops soread_filtops = {
176 	.f_isfd = 1,
177 	.f_detach = filt_sordetach,
178 	.f_event = filt_soread,
179 };
180 static struct filterops sowrite_filtops = {
181 	.f_isfd = 1,
182 	.f_detach = filt_sowdetach,
183 	.f_event = filt_sowrite,
184 };
185 static struct filterops soempty_filtops = {
186 	.f_isfd = 1,
187 	.f_detach = filt_sowdetach,
188 	.f_event = filt_soempty,
189 };
190 
191 so_gen_t	so_gencnt;	/* generation count for sockets */
192 
193 MALLOC_DEFINE(M_SONAME, "soname", "socket name");
194 MALLOC_DEFINE(M_PCB, "pcb", "protocol control block");
195 
196 #define	VNET_SO_ASSERT(so)						\
197 	VNET_ASSERT(curvnet != NULL,					\
198 	    ("%s:%d curvnet is NULL, so=%p", __func__, __LINE__, (so)));
199 
200 VNET_DEFINE(struct hhook_head *, socket_hhh[HHOOK_SOCKET_LAST + 1]);
201 #define	V_socket_hhh		VNET(socket_hhh)
202 
203 /*
204  * Limit on the number of connections in the listen queue waiting
205  * for accept(2).
206  * NB: The original sysctl somaxconn is still available but hidden
207  * to prevent confusion about the actual purpose of this number.
208  */
209 static u_int somaxconn = SOMAXCONN;
210 
211 static int
212 sysctl_somaxconn(SYSCTL_HANDLER_ARGS)
213 {
214 	int error;
215 	int val;
216 
217 	val = somaxconn;
218 	error = sysctl_handle_int(oidp, &val, 0, req);
219 	if (error || !req->newptr )
220 		return (error);
221 
222 	/*
223 	 * The purpose of the UINT_MAX / 3 limit, is so that the formula
224 	 *   3 * so_qlimit / 2
225 	 * below, will not overflow.
226          */
227 
228 	if (val < 1 || val > UINT_MAX / 3)
229 		return (EINVAL);
230 
231 	somaxconn = val;
232 	return (0);
233 }
234 SYSCTL_PROC(_kern_ipc, OID_AUTO, soacceptqueue, CTLTYPE_UINT | CTLFLAG_RW,
235     0, sizeof(int), sysctl_somaxconn, "I",
236     "Maximum listen socket pending connection accept queue size");
237 SYSCTL_PROC(_kern_ipc, KIPC_SOMAXCONN, somaxconn,
238     CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_SKIP,
239     0, sizeof(int), sysctl_somaxconn, "I",
240     "Maximum listen socket pending connection accept queue size (compat)");
241 
242 static int numopensockets;
243 SYSCTL_INT(_kern_ipc, OID_AUTO, numopensockets, CTLFLAG_RD,
244     &numopensockets, 0, "Number of open sockets");
245 
246 /*
247  * accept_mtx locks down per-socket fields relating to accept queues.  See
248  * socketvar.h for an annotation of the protected fields of struct socket.
249  */
250 struct mtx accept_mtx;
251 MTX_SYSINIT(accept_mtx, &accept_mtx, "accept", MTX_DEF);
252 
253 /*
254  * so_global_mtx protects so_gencnt, numopensockets, and the per-socket
255  * so_gencnt field.
256  */
257 static struct mtx so_global_mtx;
258 MTX_SYSINIT(so_global_mtx, &so_global_mtx, "so_glabel", MTX_DEF);
259 
260 /*
261  * General IPC sysctl name space, used by sockets and a variety of other IPC
262  * types.
263  */
264 SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW, 0, "IPC");
265 
266 /*
267  * Initialize the socket subsystem and set up the socket
268  * memory allocator.
269  */
270 static uma_zone_t socket_zone;
271 int	maxsockets;
272 
273 static void
274 socket_zone_change(void *tag)
275 {
276 
277 	maxsockets = uma_zone_set_max(socket_zone, maxsockets);
278 }
279 
280 static void
281 socket_hhook_register(int subtype)
282 {
283 
284 	if (hhook_head_register(HHOOK_TYPE_SOCKET, subtype,
285 	    &V_socket_hhh[subtype],
286 	    HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
287 		printf("%s: WARNING: unable to register hook\n", __func__);
288 }
289 
290 static void
291 socket_hhook_deregister(int subtype)
292 {
293 
294 	if (hhook_head_deregister(V_socket_hhh[subtype]) != 0)
295 		printf("%s: WARNING: unable to deregister hook\n", __func__);
296 }
297 
298 static void
299 socket_init(void *tag)
300 {
301 
302 	socket_zone = uma_zcreate("socket", sizeof(struct socket), NULL, NULL,
303 	    NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
304 	maxsockets = uma_zone_set_max(socket_zone, maxsockets);
305 	uma_zone_set_warning(socket_zone, "kern.ipc.maxsockets limit reached");
306 	EVENTHANDLER_REGISTER(maxsockets_change, socket_zone_change, NULL,
307 	    EVENTHANDLER_PRI_FIRST);
308 }
309 SYSINIT(socket, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY, socket_init, NULL);
310 
311 static void
312 socket_vnet_init(const void *unused __unused)
313 {
314 	int i;
315 
316 	/* We expect a contiguous range */
317 	for (i = 0; i <= HHOOK_SOCKET_LAST; i++)
318 		socket_hhook_register(i);
319 }
320 VNET_SYSINIT(socket_vnet_init, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY,
321     socket_vnet_init, NULL);
322 
323 static void
324 socket_vnet_uninit(const void *unused __unused)
325 {
326 	int i;
327 
328 	for (i = 0; i <= HHOOK_SOCKET_LAST; i++)
329 		socket_hhook_deregister(i);
330 }
331 VNET_SYSUNINIT(socket_vnet_uninit, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY,
332     socket_vnet_uninit, NULL);
333 
334 /*
335  * Initialise maxsockets.  This SYSINIT must be run after
336  * tunable_mbinit().
337  */
338 static void
339 init_maxsockets(void *ignored)
340 {
341 
342 	TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets);
343 	maxsockets = imax(maxsockets, maxfiles);
344 }
345 SYSINIT(param, SI_SUB_TUNABLES, SI_ORDER_ANY, init_maxsockets, NULL);
346 
347 /*
348  * Sysctl to get and set the maximum global sockets limit.  Notify protocols
349  * of the change so that they can update their dependent limits as required.
350  */
351 static int
352 sysctl_maxsockets(SYSCTL_HANDLER_ARGS)
353 {
354 	int error, newmaxsockets;
355 
356 	newmaxsockets = maxsockets;
357 	error = sysctl_handle_int(oidp, &newmaxsockets, 0, req);
358 	if (error == 0 && req->newptr) {
359 		if (newmaxsockets > maxsockets &&
360 		    newmaxsockets <= maxfiles) {
361 			maxsockets = newmaxsockets;
362 			EVENTHANDLER_INVOKE(maxsockets_change);
363 		} else
364 			error = EINVAL;
365 	}
366 	return (error);
367 }
368 SYSCTL_PROC(_kern_ipc, OID_AUTO, maxsockets, CTLTYPE_INT|CTLFLAG_RW,
369     &maxsockets, 0, sysctl_maxsockets, "IU",
370     "Maximum number of sockets available");
371 
372 /*
373  * Socket operation routines.  These routines are called by the routines in
374  * sys_socket.c or from a system process, and implement the semantics of
375  * socket operations by switching out to the protocol specific routines.
376  */
377 
378 /*
379  * Get a socket structure from our zone, and initialize it.  Note that it
380  * would probably be better to allocate socket and PCB at the same time, but
381  * I'm not convinced that all the protocols can be easily modified to do
382  * this.
383  *
384  * soalloc() returns a socket with a ref count of 0.
385  */
386 static struct socket *
387 soalloc(struct vnet *vnet)
388 {
389 	struct socket *so;
390 
391 	so = uma_zalloc(socket_zone, M_NOWAIT | M_ZERO);
392 	if (so == NULL)
393 		return (NULL);
394 #ifdef MAC
395 	if (mac_socket_init(so, M_NOWAIT) != 0) {
396 		uma_zfree(socket_zone, so);
397 		return (NULL);
398 	}
399 #endif
400 	if (khelp_init_osd(HELPER_CLASS_SOCKET, &so->osd)) {
401 		uma_zfree(socket_zone, so);
402 		return (NULL);
403 	}
404 
405 	/*
406 	 * The socket locking protocol allows to lock 2 sockets at a time,
407 	 * however, the first one must be a listening socket.  WITNESS lacks
408 	 * a feature to change class of an existing lock, so we use DUPOK.
409 	 */
410 	mtx_init(&so->so_lock, "socket", NULL, MTX_DEF | MTX_DUPOK);
411 	SOCKBUF_LOCK_INIT(&so->so_snd, "so_snd");
412 	SOCKBUF_LOCK_INIT(&so->so_rcv, "so_rcv");
413 	so->so_rcv.sb_sel = &so->so_rdsel;
414 	so->so_snd.sb_sel = &so->so_wrsel;
415 	sx_init(&so->so_snd.sb_sx, "so_snd_sx");
416 	sx_init(&so->so_rcv.sb_sx, "so_rcv_sx");
417 	TAILQ_INIT(&so->so_snd.sb_aiojobq);
418 	TAILQ_INIT(&so->so_rcv.sb_aiojobq);
419 	TASK_INIT(&so->so_snd.sb_aiotask, 0, soaio_snd, so);
420 	TASK_INIT(&so->so_rcv.sb_aiotask, 0, soaio_rcv, so);
421 #ifdef VIMAGE
422 	VNET_ASSERT(vnet != NULL, ("%s:%d vnet is NULL, so=%p",
423 	    __func__, __LINE__, so));
424 	so->so_vnet = vnet;
425 #endif
426 	/* We shouldn't need the so_global_mtx */
427 	if (hhook_run_socket(so, NULL, HHOOK_SOCKET_CREATE)) {
428 		/* Do we need more comprehensive error returns? */
429 		uma_zfree(socket_zone, so);
430 		return (NULL);
431 	}
432 	mtx_lock(&so_global_mtx);
433 	so->so_gencnt = ++so_gencnt;
434 	++numopensockets;
435 #ifdef VIMAGE
436 	vnet->vnet_sockcnt++;
437 #endif
438 	mtx_unlock(&so_global_mtx);
439 
440 	return (so);
441 }
442 
443 /*
444  * Free the storage associated with a socket at the socket layer, tear down
445  * locks, labels, etc.  All protocol state is assumed already to have been
446  * torn down (and possibly never set up) by the caller.
447  */
448 static void
449 sodealloc(struct socket *so)
450 {
451 
452 	KASSERT(so->so_count == 0, ("sodealloc(): so_count %d", so->so_count));
453 	KASSERT(so->so_pcb == NULL, ("sodealloc(): so_pcb != NULL"));
454 
455 	mtx_lock(&so_global_mtx);
456 	so->so_gencnt = ++so_gencnt;
457 	--numopensockets;	/* Could be below, but faster here. */
458 #ifdef VIMAGE
459 	VNET_ASSERT(so->so_vnet != NULL, ("%s:%d so_vnet is NULL, so=%p",
460 	    __func__, __LINE__, so));
461 	so->so_vnet->vnet_sockcnt--;
462 #endif
463 	mtx_unlock(&so_global_mtx);
464 	if (so->so_rcv.sb_hiwat)
465 		(void)chgsbsize(so->so_cred->cr_uidinfo,
466 		    &so->so_rcv.sb_hiwat, 0, RLIM_INFINITY);
467 	if (so->so_snd.sb_hiwat)
468 		(void)chgsbsize(so->so_cred->cr_uidinfo,
469 		    &so->so_snd.sb_hiwat, 0, RLIM_INFINITY);
470 #ifdef MAC
471 	mac_socket_destroy(so);
472 #endif
473 	hhook_run_socket(so, NULL, HHOOK_SOCKET_CLOSE);
474 
475 	crfree(so->so_cred);
476 	khelp_destroy_osd(&so->osd);
477 	if (SOLISTENING(so)) {
478 		if (so->sol_accept_filter != NULL)
479 			accept_filt_setopt(so, NULL);
480 	} else {
481 		sx_destroy(&so->so_snd.sb_sx);
482 		sx_destroy(&so->so_rcv.sb_sx);
483 		SOCKBUF_LOCK_DESTROY(&so->so_snd);
484 		SOCKBUF_LOCK_DESTROY(&so->so_rcv);
485 	}
486 	mtx_destroy(&so->so_lock);
487 	uma_zfree(socket_zone, so);
488 }
489 
490 /*
491  * socreate returns a socket with a ref count of 1.  The socket should be
492  * closed with soclose().
493  */
494 int
495 socreate(int dom, struct socket **aso, int type, int proto,
496     struct ucred *cred, struct thread *td)
497 {
498 	struct protosw *prp;
499 	struct socket *so;
500 	int error;
501 
502 	if (proto)
503 		prp = pffindproto(dom, proto, type);
504 	else
505 		prp = pffindtype(dom, type);
506 
507 	if (prp == NULL) {
508 		/* No support for domain. */
509 		if (pffinddomain(dom) == NULL)
510 			return (EAFNOSUPPORT);
511 		/* No support for socket type. */
512 		if (proto == 0 && type != 0)
513 			return (EPROTOTYPE);
514 		return (EPROTONOSUPPORT);
515 	}
516 	if (prp->pr_usrreqs->pru_attach == NULL ||
517 	    prp->pr_usrreqs->pru_attach == pru_attach_notsupp)
518 		return (EPROTONOSUPPORT);
519 
520 	if (prison_check_af(cred, prp->pr_domain->dom_family) != 0)
521 		return (EPROTONOSUPPORT);
522 
523 	if (prp->pr_type != type)
524 		return (EPROTOTYPE);
525 	so = soalloc(CRED_TO_VNET(cred));
526 	if (so == NULL)
527 		return (ENOBUFS);
528 
529 	so->so_type = type;
530 	so->so_cred = crhold(cred);
531 	if ((prp->pr_domain->dom_family == PF_INET) ||
532 	    (prp->pr_domain->dom_family == PF_INET6) ||
533 	    (prp->pr_domain->dom_family == PF_ROUTE))
534 		so->so_fibnum = td->td_proc->p_fibnum;
535 	else
536 		so->so_fibnum = 0;
537 	so->so_proto = prp;
538 #ifdef MAC
539 	mac_socket_create(cred, so);
540 #endif
541 	knlist_init(&so->so_rdsel.si_note, so, so_rdknl_lock, so_rdknl_unlock,
542 	    so_rdknl_assert_locked, so_rdknl_assert_unlocked);
543 	knlist_init(&so->so_wrsel.si_note, so, so_wrknl_lock, so_wrknl_unlock,
544 	    so_wrknl_assert_locked, so_wrknl_assert_unlocked);
545 	/*
546 	 * Auto-sizing of socket buffers is managed by the protocols and
547 	 * the appropriate flags must be set in the pru_attach function.
548 	 */
549 	CURVNET_SET(so->so_vnet);
550 	error = (*prp->pr_usrreqs->pru_attach)(so, proto, td);
551 	CURVNET_RESTORE();
552 	if (error) {
553 		sodealloc(so);
554 		return (error);
555 	}
556 	soref(so);
557 	*aso = so;
558 	return (0);
559 }
560 
561 #ifdef REGRESSION
562 static int regression_sonewconn_earlytest = 1;
563 SYSCTL_INT(_regression, OID_AUTO, sonewconn_earlytest, CTLFLAG_RW,
564     &regression_sonewconn_earlytest, 0, "Perform early sonewconn limit test");
565 #endif
566 
567 /*
568  * When an attempt at a new connection is noted on a socket which accepts
569  * connections, sonewconn is called.  If the connection is possible (subject
570  * to space constraints, etc.) then we allocate a new structure, properly
571  * linked into the data structure of the original socket, and return this.
572  * Connstatus may be 0, or SS_ISCONFIRMING, or SS_ISCONNECTED.
573  *
574  * Note: the ref count on the socket is 0 on return.
575  */
576 struct socket *
577 sonewconn(struct socket *head, int connstatus)
578 {
579 	static struct timeval lastover;
580 	static struct timeval overinterval = { 60, 0 };
581 	static int overcount;
582 
583 	struct socket *so;
584 	u_int over;
585 
586 	SOLISTEN_LOCK(head);
587 	over = (head->sol_qlen > 3 * head->sol_qlimit / 2);
588 	SOLISTEN_UNLOCK(head);
589 #ifdef REGRESSION
590 	if (regression_sonewconn_earlytest && over) {
591 #else
592 	if (over) {
593 #endif
594 		overcount++;
595 
596 		if (ratecheck(&lastover, &overinterval)) {
597 			log(LOG_DEBUG, "%s: pcb %p: Listen queue overflow: "
598 			    "%i already in queue awaiting acceptance "
599 			    "(%d occurrences)\n",
600 			    __func__, head->so_pcb, head->sol_qlen, overcount);
601 
602 			overcount = 0;
603 		}
604 
605 		return (NULL);
606 	}
607 	VNET_ASSERT(head->so_vnet != NULL, ("%s: so %p vnet is NULL",
608 	    __func__, head));
609 	so = soalloc(head->so_vnet);
610 	if (so == NULL) {
611 		log(LOG_DEBUG, "%s: pcb %p: New socket allocation failure: "
612 		    "limit reached or out of memory\n",
613 		    __func__, head->so_pcb);
614 		return (NULL);
615 	}
616 	so->so_listen = head;
617 	so->so_type = head->so_type;
618 	so->so_linger = head->so_linger;
619 	so->so_state = head->so_state | SS_NOFDREF;
620 	so->so_fibnum = head->so_fibnum;
621 	so->so_proto = head->so_proto;
622 	so->so_cred = crhold(head->so_cred);
623 #ifdef MAC
624 	mac_socket_newconn(head, so);
625 #endif
626 	knlist_init(&so->so_rdsel.si_note, so, so_rdknl_lock, so_rdknl_unlock,
627 	    so_rdknl_assert_locked, so_rdknl_assert_unlocked);
628 	knlist_init(&so->so_wrsel.si_note, so, so_wrknl_lock, so_wrknl_unlock,
629 	    so_wrknl_assert_locked, so_wrknl_assert_unlocked);
630 	VNET_SO_ASSERT(head);
631 	if (soreserve(so, head->sol_sbsnd_hiwat, head->sol_sbrcv_hiwat)) {
632 		sodealloc(so);
633 		log(LOG_DEBUG, "%s: pcb %p: soreserve() failed\n",
634 		    __func__, head->so_pcb);
635 		return (NULL);
636 	}
637 	if ((*so->so_proto->pr_usrreqs->pru_attach)(so, 0, NULL)) {
638 		sodealloc(so);
639 		log(LOG_DEBUG, "%s: pcb %p: pru_attach() failed\n",
640 		    __func__, head->so_pcb);
641 		return (NULL);
642 	}
643 	so->so_rcv.sb_lowat = head->sol_sbrcv_lowat;
644 	so->so_snd.sb_lowat = head->sol_sbsnd_lowat;
645 	so->so_rcv.sb_timeo = head->sol_sbrcv_timeo;
646 	so->so_snd.sb_timeo = head->sol_sbsnd_timeo;
647 	so->so_rcv.sb_flags |= head->sol_sbrcv_flags & SB_AUTOSIZE;
648 	so->so_snd.sb_flags |= head->sol_sbsnd_flags & SB_AUTOSIZE;
649 
650 	SOLISTEN_LOCK(head);
651 	if (head->sol_accept_filter != NULL)
652 		connstatus = 0;
653 	so->so_state |= connstatus;
654 	so->so_options = head->so_options & ~SO_ACCEPTCONN;
655 	soref(head); /* A socket on (in)complete queue refs head. */
656 	if (connstatus) {
657 		TAILQ_INSERT_TAIL(&head->sol_comp, so, so_list);
658 		so->so_qstate = SQ_COMP;
659 		head->sol_qlen++;
660 		solisten_wakeup(head);	/* unlocks */
661 	} else {
662 		/*
663 		 * Keep removing sockets from the head until there's room for
664 		 * us to insert on the tail.  In pre-locking revisions, this
665 		 * was a simple if(), but as we could be racing with other
666 		 * threads and soabort() requires dropping locks, we must
667 		 * loop waiting for the condition to be true.
668 		 */
669 		while (head->sol_incqlen > head->sol_qlimit) {
670 			struct socket *sp;
671 
672 			sp = TAILQ_FIRST(&head->sol_incomp);
673 			TAILQ_REMOVE(&head->sol_incomp, sp, so_list);
674 			head->sol_incqlen--;
675 			SOCK_LOCK(sp);
676 			sp->so_qstate = SQ_NONE;
677 			sp->so_listen = NULL;
678 			SOCK_UNLOCK(sp);
679 			sorele(head);	/* does SOLISTEN_UNLOCK, head stays */
680 			soabort(sp);
681 			SOLISTEN_LOCK(head);
682 		}
683 		TAILQ_INSERT_TAIL(&head->sol_incomp, so, so_list);
684 		so->so_qstate = SQ_INCOMP;
685 		head->sol_incqlen++;
686 		SOLISTEN_UNLOCK(head);
687 	}
688 	return (so);
689 }
690 
691 #ifdef SCTP
692 /*
693  * Socket part of sctp_peeloff().  Detach a new socket from an
694  * association.  The new socket is returned with a reference.
695  */
696 struct socket *
697 sopeeloff(struct socket *head)
698 {
699 	struct socket *so;
700 
701 	VNET_ASSERT(head->so_vnet != NULL, ("%s:%d so_vnet is NULL, head=%p",
702 	    __func__, __LINE__, head));
703 	so = soalloc(head->so_vnet);
704 	if (so == NULL) {
705 		log(LOG_DEBUG, "%s: pcb %p: New socket allocation failure: "
706 		    "limit reached or out of memory\n",
707 		    __func__, head->so_pcb);
708 		return (NULL);
709 	}
710 	so->so_type = head->so_type;
711 	so->so_options = head->so_options;
712 	so->so_linger = head->so_linger;
713 	so->so_state = (head->so_state & SS_NBIO) | SS_ISCONNECTED;
714 	so->so_fibnum = head->so_fibnum;
715 	so->so_proto = head->so_proto;
716 	so->so_cred = crhold(head->so_cred);
717 #ifdef MAC
718 	mac_socket_newconn(head, so);
719 #endif
720 	knlist_init(&so->so_rdsel.si_note, so, so_rdknl_lock, so_rdknl_unlock,
721 	    so_rdknl_assert_locked, so_rdknl_assert_unlocked);
722 	knlist_init(&so->so_wrsel.si_note, so, so_wrknl_lock, so_wrknl_unlock,
723 	    so_wrknl_assert_locked, so_wrknl_assert_unlocked);
724 	VNET_SO_ASSERT(head);
725 	if (soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat)) {
726 		sodealloc(so);
727 		log(LOG_DEBUG, "%s: pcb %p: soreserve() failed\n",
728 		    __func__, head->so_pcb);
729 		return (NULL);
730 	}
731 	if ((*so->so_proto->pr_usrreqs->pru_attach)(so, 0, NULL)) {
732 		sodealloc(so);
733 		log(LOG_DEBUG, "%s: pcb %p: pru_attach() failed\n",
734 		    __func__, head->so_pcb);
735 		return (NULL);
736 	}
737 	so->so_rcv.sb_lowat = head->so_rcv.sb_lowat;
738 	so->so_snd.sb_lowat = head->so_snd.sb_lowat;
739 	so->so_rcv.sb_timeo = head->so_rcv.sb_timeo;
740 	so->so_snd.sb_timeo = head->so_snd.sb_timeo;
741 	so->so_rcv.sb_flags |= head->so_rcv.sb_flags & SB_AUTOSIZE;
742 	so->so_snd.sb_flags |= head->so_snd.sb_flags & SB_AUTOSIZE;
743 
744 	soref(so);
745 
746 	return (so);
747 }
748 #endif	/* SCTP */
749 
750 int
751 sobind(struct socket *so, struct sockaddr *nam, struct thread *td)
752 {
753 	int error;
754 
755 	CURVNET_SET(so->so_vnet);
756 	error = (*so->so_proto->pr_usrreqs->pru_bind)(so, nam, td);
757 	CURVNET_RESTORE();
758 	return (error);
759 }
760 
761 int
762 sobindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
763 {
764 	int error;
765 
766 	CURVNET_SET(so->so_vnet);
767 	error = (*so->so_proto->pr_usrreqs->pru_bindat)(fd, so, nam, td);
768 	CURVNET_RESTORE();
769 	return (error);
770 }
771 
772 /*
773  * solisten() transitions a socket from a non-listening state to a listening
774  * state, but can also be used to update the listen queue depth on an
775  * existing listen socket.  The protocol will call back into the sockets
776  * layer using solisten_proto_check() and solisten_proto() to check and set
777  * socket-layer listen state.  Call backs are used so that the protocol can
778  * acquire both protocol and socket layer locks in whatever order is required
779  * by the protocol.
780  *
781  * Protocol implementors are advised to hold the socket lock across the
782  * socket-layer test and set to avoid races at the socket layer.
783  */
784 int
785 solisten(struct socket *so, int backlog, struct thread *td)
786 {
787 	int error;
788 
789 	CURVNET_SET(so->so_vnet);
790 	error = (*so->so_proto->pr_usrreqs->pru_listen)(so, backlog, td);
791 	CURVNET_RESTORE();
792 	return (error);
793 }
794 
795 int
796 solisten_proto_check(struct socket *so)
797 {
798 
799 	SOCK_LOCK_ASSERT(so);
800 
801 	if (so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING |
802 	    SS_ISDISCONNECTING))
803 		return (EINVAL);
804 	return (0);
805 }
806 
807 void
808 solisten_proto(struct socket *so, int backlog)
809 {
810 	int sbrcv_lowat, sbsnd_lowat;
811 	u_int sbrcv_hiwat, sbsnd_hiwat;
812 	short sbrcv_flags, sbsnd_flags;
813 	sbintime_t sbrcv_timeo, sbsnd_timeo;
814 
815 	SOCK_LOCK_ASSERT(so);
816 
817 	if (SOLISTENING(so))
818 		goto listening;
819 
820 	/*
821 	 * Change this socket to listening state.
822 	 */
823 	sbrcv_lowat = so->so_rcv.sb_lowat;
824 	sbsnd_lowat = so->so_snd.sb_lowat;
825 	sbrcv_hiwat = so->so_rcv.sb_hiwat;
826 	sbsnd_hiwat = so->so_snd.sb_hiwat;
827 	sbrcv_flags = so->so_rcv.sb_flags;
828 	sbsnd_flags = so->so_snd.sb_flags;
829 	sbrcv_timeo = so->so_rcv.sb_timeo;
830 	sbsnd_timeo = so->so_snd.sb_timeo;
831 
832 	sbdestroy(&so->so_snd, so);
833 	sbdestroy(&so->so_rcv, so);
834 	sx_destroy(&so->so_snd.sb_sx);
835 	sx_destroy(&so->so_rcv.sb_sx);
836 	SOCKBUF_LOCK_DESTROY(&so->so_snd);
837 	SOCKBUF_LOCK_DESTROY(&so->so_rcv);
838 
839 #ifdef INVARIANTS
840 	bzero(&so->so_rcv,
841 	    sizeof(struct socket) - offsetof(struct socket, so_rcv));
842 #endif
843 
844 	so->sol_sbrcv_lowat = sbrcv_lowat;
845 	so->sol_sbsnd_lowat = sbsnd_lowat;
846 	so->sol_sbrcv_hiwat = sbrcv_hiwat;
847 	so->sol_sbsnd_hiwat = sbsnd_hiwat;
848 	so->sol_sbrcv_flags = sbrcv_flags;
849 	so->sol_sbsnd_flags = sbsnd_flags;
850 	so->sol_sbrcv_timeo = sbrcv_timeo;
851 	so->sol_sbsnd_timeo = sbsnd_timeo;
852 
853 	so->sol_qlen = so->sol_incqlen = 0;
854 	TAILQ_INIT(&so->sol_incomp);
855 	TAILQ_INIT(&so->sol_comp);
856 
857 	so->sol_accept_filter = NULL;
858 	so->sol_accept_filter_arg = NULL;
859 	so->sol_accept_filter_str = NULL;
860 
861 	so->so_options |= SO_ACCEPTCONN;
862 
863 listening:
864 	if (backlog < 0 || backlog > somaxconn)
865 		backlog = somaxconn;
866 	so->sol_qlimit = backlog;
867 }
868 
869 /*
870  * Wakeup listeners/subsystems once we have a complete connection.
871  * Enters with lock, returns unlocked.
872  */
873 void
874 solisten_wakeup(struct socket *sol)
875 {
876 
877 	if (sol->sol_upcall != NULL)
878 		(void )sol->sol_upcall(sol, sol->sol_upcallarg, M_NOWAIT);
879 	else {
880 		selwakeuppri(&sol->so_rdsel, PSOCK);
881 		KNOTE_LOCKED(&sol->so_rdsel.si_note, 0);
882 	}
883 	SOLISTEN_UNLOCK(sol);
884 	wakeup_one(&sol->sol_comp);
885 }
886 
887 /*
888  * Return single connection off a listening socket queue.  Main consumer of
889  * the function is kern_accept4().  Some modules, that do their own accept
890  * management also use the function.
891  *
892  * Listening socket must be locked on entry and is returned unlocked on
893  * return.
894  * The flags argument is set of accept4(2) flags and ACCEPT4_INHERIT.
895  */
896 int
897 solisten_dequeue(struct socket *head, struct socket **ret, int flags)
898 {
899 	struct socket *so;
900 	int error;
901 
902 	SOLISTEN_LOCK_ASSERT(head);
903 
904 	while (!(head->so_state & SS_NBIO) && TAILQ_EMPTY(&head->sol_comp) &&
905 	    head->so_error == 0) {
906 		error = msleep(&head->sol_comp, &head->so_lock, PSOCK | PCATCH,
907 		    "accept", 0);
908 		if (error != 0) {
909 			SOLISTEN_UNLOCK(head);
910 			return (error);
911 		}
912 	}
913 	if (head->so_error) {
914 		error = head->so_error;
915 		head->so_error = 0;
916 		SOLISTEN_UNLOCK(head);
917 		return (error);
918         }
919 	if ((head->so_state & SS_NBIO) && TAILQ_EMPTY(&head->sol_comp)) {
920 		SOLISTEN_UNLOCK(head);
921 		return (EWOULDBLOCK);
922 	}
923 	so = TAILQ_FIRST(&head->sol_comp);
924 	SOCK_LOCK(so);
925 	KASSERT(so->so_qstate == SQ_COMP,
926 	    ("%s: so %p not SQ_COMP", __func__, so));
927 	soref(so);
928 	head->sol_qlen--;
929 	so->so_qstate = SQ_NONE;
930 	so->so_listen = NULL;
931 	TAILQ_REMOVE(&head->sol_comp, so, so_list);
932 	if (flags & ACCEPT4_INHERIT)
933 		so->so_state |= (head->so_state & SS_NBIO);
934 	else
935 		so->so_state |= (flags & SOCK_NONBLOCK) ? SS_NBIO : 0;
936 	SOCK_UNLOCK(so);
937 	sorele(head);
938 
939 	*ret = so;
940 	return (0);
941 }
942 
943 /*
944  * Evaluate the reference count and named references on a socket; if no
945  * references remain, free it.  This should be called whenever a reference is
946  * released, such as in sorele(), but also when named reference flags are
947  * cleared in socket or protocol code.
948  *
949  * sofree() will free the socket if:
950  *
951  * - There are no outstanding file descriptor references or related consumers
952  *   (so_count == 0).
953  *
954  * - The socket has been closed by user space, if ever open (SS_NOFDREF).
955  *
956  * - The protocol does not have an outstanding strong reference on the socket
957  *   (SS_PROTOREF).
958  *
959  * - The socket is not in a completed connection queue, so a process has been
960  *   notified that it is present.  If it is removed, the user process may
961  *   block in accept() despite select() saying the socket was ready.
962  */
963 void
964 sofree(struct socket *so)
965 {
966 	struct protosw *pr = so->so_proto;
967 
968 	SOCK_LOCK_ASSERT(so);
969 
970 	if ((so->so_state & SS_NOFDREF) == 0 || so->so_count != 0 ||
971 	    (so->so_state & SS_PROTOREF) || (so->so_qstate == SQ_COMP)) {
972 		SOCK_UNLOCK(so);
973 		return;
974 	}
975 
976 	if (!SOLISTENING(so) && so->so_qstate == SQ_INCOMP) {
977 		struct socket *sol;
978 
979 		sol = so->so_listen;
980 		KASSERT(sol, ("%s: so %p on incomp of NULL", __func__, so));
981 
982 		/*
983 		 * To solve race between close of a listening socket and
984 		 * a socket on its incomplete queue, we need to lock both.
985 		 * The order is first listening socket, then regular.
986 		 * Since we don't have SS_NOFDREF neither SS_PROTOREF, this
987 		 * function and the listening socket are the only pointers
988 		 * to so.  To preserve so and sol, we reference both and then
989 		 * relock.
990 		 * After relock the socket may not move to so_comp since it
991 		 * doesn't have PCB already, but it may be removed from
992 		 * so_incomp. If that happens, we share responsiblity on
993 		 * freeing the socket, but soclose() has already removed
994 		 * it from queue.
995 		 */
996 		soref(sol);
997 		soref(so);
998 		SOCK_UNLOCK(so);
999 		SOLISTEN_LOCK(sol);
1000 		SOCK_LOCK(so);
1001 		if (so->so_qstate == SQ_INCOMP) {
1002 			KASSERT(so->so_listen == sol,
1003 			    ("%s: so %p migrated out of sol %p",
1004 			    __func__, so, sol));
1005 			TAILQ_REMOVE(&sol->sol_incomp, so, so_list);
1006 			sol->sol_incqlen--;
1007 			/* This is guarenteed not to be the last. */
1008 			refcount_release(&sol->so_count);
1009 			so->so_qstate = SQ_NONE;
1010 			so->so_listen = NULL;
1011 		} else
1012 			KASSERT(so->so_listen == NULL,
1013 			    ("%s: so %p not on (in)comp with so_listen",
1014 			    __func__, so));
1015 		sorele(sol);
1016 		KASSERT(so->so_count == 1,
1017 		    ("%s: so %p count %u", __func__, so, so->so_count));
1018 		so->so_count = 0;
1019 	}
1020 	if (SOLISTENING(so))
1021 		so->so_error = ECONNABORTED;
1022 	SOCK_UNLOCK(so);
1023 
1024 	VNET_SO_ASSERT(so);
1025 	if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose != NULL)
1026 		(*pr->pr_domain->dom_dispose)(so);
1027 	if (pr->pr_usrreqs->pru_detach != NULL)
1028 		(*pr->pr_usrreqs->pru_detach)(so);
1029 
1030 	/*
1031 	 * From this point on, we assume that no other references to this
1032 	 * socket exist anywhere else in the stack.  Therefore, no locks need
1033 	 * to be acquired or held.
1034 	 *
1035 	 * We used to do a lot of socket buffer and socket locking here, as
1036 	 * well as invoke sorflush() and perform wakeups.  The direct call to
1037 	 * dom_dispose() and sbrelease_internal() are an inlining of what was
1038 	 * necessary from sorflush().
1039 	 *
1040 	 * Notice that the socket buffer and kqueue state are torn down
1041 	 * before calling pru_detach.  This means that protocols shold not
1042 	 * assume they can perform socket wakeups, etc, in their detach code.
1043 	 */
1044 	if (!SOLISTENING(so)) {
1045 		sbdestroy(&so->so_snd, so);
1046 		sbdestroy(&so->so_rcv, so);
1047 	}
1048 	seldrain(&so->so_rdsel);
1049 	seldrain(&so->so_wrsel);
1050 	knlist_destroy(&so->so_rdsel.si_note);
1051 	knlist_destroy(&so->so_wrsel.si_note);
1052 	sodealloc(so);
1053 }
1054 
1055 /*
1056  * Close a socket on last file table reference removal.  Initiate disconnect
1057  * if connected.  Free socket when disconnect complete.
1058  *
1059  * This function will sorele() the socket.  Note that soclose() may be called
1060  * prior to the ref count reaching zero.  The actual socket structure will
1061  * not be freed until the ref count reaches zero.
1062  */
1063 int
1064 soclose(struct socket *so)
1065 {
1066 	struct accept_queue lqueue;
1067 	bool listening;
1068 	int error = 0;
1069 
1070 	KASSERT(!(so->so_state & SS_NOFDREF), ("soclose: SS_NOFDREF on enter"));
1071 
1072 	CURVNET_SET(so->so_vnet);
1073 	funsetown(&so->so_sigio);
1074 	if (so->so_state & SS_ISCONNECTED) {
1075 		if ((so->so_state & SS_ISDISCONNECTING) == 0) {
1076 			error = sodisconnect(so);
1077 			if (error) {
1078 				if (error == ENOTCONN)
1079 					error = 0;
1080 				goto drop;
1081 			}
1082 		}
1083 		if (so->so_options & SO_LINGER) {
1084 			if ((so->so_state & SS_ISDISCONNECTING) &&
1085 			    (so->so_state & SS_NBIO))
1086 				goto drop;
1087 			while (so->so_state & SS_ISCONNECTED) {
1088 				error = tsleep(&so->so_timeo,
1089 				    PSOCK | PCATCH, "soclos",
1090 				    so->so_linger * hz);
1091 				if (error)
1092 					break;
1093 			}
1094 		}
1095 	}
1096 
1097 drop:
1098 	if (so->so_proto->pr_usrreqs->pru_close != NULL)
1099 		(*so->so_proto->pr_usrreqs->pru_close)(so);
1100 
1101 	SOCK_LOCK(so);
1102 	if ((listening = (so->so_options & SO_ACCEPTCONN))) {
1103 		struct socket *sp;
1104 
1105 		TAILQ_INIT(&lqueue);
1106 		TAILQ_SWAP(&lqueue, &so->sol_incomp, socket, so_list);
1107 		TAILQ_CONCAT(&lqueue, &so->sol_comp, so_list);
1108 
1109 		so->sol_qlen = so->sol_incqlen = 0;
1110 
1111 		TAILQ_FOREACH(sp, &lqueue, so_list) {
1112 			SOCK_LOCK(sp);
1113 			sp->so_qstate = SQ_NONE;
1114 			sp->so_listen = NULL;
1115 			SOCK_UNLOCK(sp);
1116 			/* Guaranteed not to be the last. */
1117 			refcount_release(&so->so_count);
1118 		}
1119 	}
1120 	KASSERT((so->so_state & SS_NOFDREF) == 0, ("soclose: NOFDREF"));
1121 	so->so_state |= SS_NOFDREF;
1122 	sorele(so);
1123 	if (listening) {
1124 		struct socket *sp;
1125 
1126 		TAILQ_FOREACH(sp, &lqueue, so_list) {
1127 			SOCK_LOCK(sp);
1128 			if (sp->so_count == 0) {
1129 				SOCK_UNLOCK(sp);
1130 				soabort(sp);
1131 			} else
1132 				/* sp is now in sofree() */
1133 				SOCK_UNLOCK(sp);
1134 		}
1135 	}
1136 	CURVNET_RESTORE();
1137 	return (error);
1138 }
1139 
1140 /*
1141  * soabort() is used to abruptly tear down a connection, such as when a
1142  * resource limit is reached (listen queue depth exceeded), or if a listen
1143  * socket is closed while there are sockets waiting to be accepted.
1144  *
1145  * This interface is tricky, because it is called on an unreferenced socket,
1146  * and must be called only by a thread that has actually removed the socket
1147  * from the listen queue it was on, or races with other threads are risked.
1148  *
1149  * This interface will call into the protocol code, so must not be called
1150  * with any socket locks held.  Protocols do call it while holding their own
1151  * recursible protocol mutexes, but this is something that should be subject
1152  * to review in the future.
1153  */
1154 void
1155 soabort(struct socket *so)
1156 {
1157 
1158 	/*
1159 	 * In as much as is possible, assert that no references to this
1160 	 * socket are held.  This is not quite the same as asserting that the
1161 	 * current thread is responsible for arranging for no references, but
1162 	 * is as close as we can get for now.
1163 	 */
1164 	KASSERT(so->so_count == 0, ("soabort: so_count"));
1165 	KASSERT((so->so_state & SS_PROTOREF) == 0, ("soabort: SS_PROTOREF"));
1166 	KASSERT(so->so_state & SS_NOFDREF, ("soabort: !SS_NOFDREF"));
1167 	KASSERT(so->so_qstate == SQ_NONE, ("soabort: !SQ_NONE"));
1168 	VNET_SO_ASSERT(so);
1169 
1170 	if (so->so_proto->pr_usrreqs->pru_abort != NULL)
1171 		(*so->so_proto->pr_usrreqs->pru_abort)(so);
1172 	SOCK_LOCK(so);
1173 	sofree(so);
1174 }
1175 
1176 int
1177 soaccept(struct socket *so, struct sockaddr **nam)
1178 {
1179 	int error;
1180 
1181 	SOCK_LOCK(so);
1182 	KASSERT((so->so_state & SS_NOFDREF) != 0, ("soaccept: !NOFDREF"));
1183 	so->so_state &= ~SS_NOFDREF;
1184 	SOCK_UNLOCK(so);
1185 
1186 	CURVNET_SET(so->so_vnet);
1187 	error = (*so->so_proto->pr_usrreqs->pru_accept)(so, nam);
1188 	CURVNET_RESTORE();
1189 	return (error);
1190 }
1191 
1192 int
1193 soconnect(struct socket *so, struct sockaddr *nam, struct thread *td)
1194 {
1195 
1196 	return (soconnectat(AT_FDCWD, so, nam, td));
1197 }
1198 
1199 int
1200 soconnectat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
1201 {
1202 	int error;
1203 
1204 	if (so->so_options & SO_ACCEPTCONN)
1205 		return (EOPNOTSUPP);
1206 
1207 	CURVNET_SET(so->so_vnet);
1208 	/*
1209 	 * If protocol is connection-based, can only connect once.
1210 	 * Otherwise, if connected, try to disconnect first.  This allows
1211 	 * user to disconnect by connecting to, e.g., a null address.
1212 	 */
1213 	if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
1214 	    ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
1215 	    (error = sodisconnect(so)))) {
1216 		error = EISCONN;
1217 	} else {
1218 		/*
1219 		 * Prevent accumulated error from previous connection from
1220 		 * biting us.
1221 		 */
1222 		so->so_error = 0;
1223 		if (fd == AT_FDCWD) {
1224 			error = (*so->so_proto->pr_usrreqs->pru_connect)(so,
1225 			    nam, td);
1226 		} else {
1227 			error = (*so->so_proto->pr_usrreqs->pru_connectat)(fd,
1228 			    so, nam, td);
1229 		}
1230 	}
1231 	CURVNET_RESTORE();
1232 
1233 	return (error);
1234 }
1235 
1236 int
1237 soconnect2(struct socket *so1, struct socket *so2)
1238 {
1239 	int error;
1240 
1241 	CURVNET_SET(so1->so_vnet);
1242 	error = (*so1->so_proto->pr_usrreqs->pru_connect2)(so1, so2);
1243 	CURVNET_RESTORE();
1244 	return (error);
1245 }
1246 
1247 int
1248 sodisconnect(struct socket *so)
1249 {
1250 	int error;
1251 
1252 	if ((so->so_state & SS_ISCONNECTED) == 0)
1253 		return (ENOTCONN);
1254 	if (so->so_state & SS_ISDISCONNECTING)
1255 		return (EALREADY);
1256 	VNET_SO_ASSERT(so);
1257 	error = (*so->so_proto->pr_usrreqs->pru_disconnect)(so);
1258 	return (error);
1259 }
1260 
1261 #define	SBLOCKWAIT(f)	(((f) & MSG_DONTWAIT) ? 0 : SBL_WAIT)
1262 
1263 int
1264 sosend_dgram(struct socket *so, struct sockaddr *addr, struct uio *uio,
1265     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
1266 {
1267 	long space;
1268 	ssize_t resid;
1269 	int clen = 0, error, dontroute;
1270 
1271 	KASSERT(so->so_type == SOCK_DGRAM, ("sosend_dgram: !SOCK_DGRAM"));
1272 	KASSERT(so->so_proto->pr_flags & PR_ATOMIC,
1273 	    ("sosend_dgram: !PR_ATOMIC"));
1274 
1275 	if (uio != NULL)
1276 		resid = uio->uio_resid;
1277 	else
1278 		resid = top->m_pkthdr.len;
1279 	/*
1280 	 * In theory resid should be unsigned.  However, space must be
1281 	 * signed, as it might be less than 0 if we over-committed, and we
1282 	 * must use a signed comparison of space and resid.  On the other
1283 	 * hand, a negative resid causes us to loop sending 0-length
1284 	 * segments to the protocol.
1285 	 */
1286 	if (resid < 0) {
1287 		error = EINVAL;
1288 		goto out;
1289 	}
1290 
1291 	dontroute =
1292 	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0;
1293 	if (td != NULL)
1294 		td->td_ru.ru_msgsnd++;
1295 	if (control != NULL)
1296 		clen = control->m_len;
1297 
1298 	SOCKBUF_LOCK(&so->so_snd);
1299 	if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
1300 		SOCKBUF_UNLOCK(&so->so_snd);
1301 		error = EPIPE;
1302 		goto out;
1303 	}
1304 	if (so->so_error) {
1305 		error = so->so_error;
1306 		so->so_error = 0;
1307 		SOCKBUF_UNLOCK(&so->so_snd);
1308 		goto out;
1309 	}
1310 	if ((so->so_state & SS_ISCONNECTED) == 0) {
1311 		/*
1312 		 * `sendto' and `sendmsg' is allowed on a connection-based
1313 		 * socket if it supports implied connect.  Return ENOTCONN if
1314 		 * not connected and no address is supplied.
1315 		 */
1316 		if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
1317 		    (so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
1318 			if ((so->so_state & SS_ISCONFIRMING) == 0 &&
1319 			    !(resid == 0 && clen != 0)) {
1320 				SOCKBUF_UNLOCK(&so->so_snd);
1321 				error = ENOTCONN;
1322 				goto out;
1323 			}
1324 		} else if (addr == NULL) {
1325 			if (so->so_proto->pr_flags & PR_CONNREQUIRED)
1326 				error = ENOTCONN;
1327 			else
1328 				error = EDESTADDRREQ;
1329 			SOCKBUF_UNLOCK(&so->so_snd);
1330 			goto out;
1331 		}
1332 	}
1333 
1334 	/*
1335 	 * Do we need MSG_OOB support in SOCK_DGRAM?  Signs here may be a
1336 	 * problem and need fixing.
1337 	 */
1338 	space = sbspace(&so->so_snd);
1339 	if (flags & MSG_OOB)
1340 		space += 1024;
1341 	space -= clen;
1342 	SOCKBUF_UNLOCK(&so->so_snd);
1343 	if (resid > space) {
1344 		error = EMSGSIZE;
1345 		goto out;
1346 	}
1347 	if (uio == NULL) {
1348 		resid = 0;
1349 		if (flags & MSG_EOR)
1350 			top->m_flags |= M_EOR;
1351 	} else {
1352 		/*
1353 		 * Copy the data from userland into a mbuf chain.
1354 		 * If no data is to be copied in, a single empty mbuf
1355 		 * is returned.
1356 		 */
1357 		top = m_uiotombuf(uio, M_WAITOK, space, max_hdr,
1358 		    (M_PKTHDR | ((flags & MSG_EOR) ? M_EOR : 0)));
1359 		if (top == NULL) {
1360 			error = EFAULT;	/* only possible error */
1361 			goto out;
1362 		}
1363 		space -= resid - uio->uio_resid;
1364 		resid = uio->uio_resid;
1365 	}
1366 	KASSERT(resid == 0, ("sosend_dgram: resid != 0"));
1367 	/*
1368 	 * XXXRW: Frobbing SO_DONTROUTE here is even worse without sblock
1369 	 * than with.
1370 	 */
1371 	if (dontroute) {
1372 		SOCK_LOCK(so);
1373 		so->so_options |= SO_DONTROUTE;
1374 		SOCK_UNLOCK(so);
1375 	}
1376 	/*
1377 	 * XXX all the SBS_CANTSENDMORE checks previously done could be out
1378 	 * of date.  We could have received a reset packet in an interrupt or
1379 	 * maybe we slept while doing page faults in uiomove() etc.  We could
1380 	 * probably recheck again inside the locking protection here, but
1381 	 * there are probably other places that this also happens.  We must
1382 	 * rethink this.
1383 	 */
1384 	VNET_SO_ASSERT(so);
1385 	error = (*so->so_proto->pr_usrreqs->pru_send)(so,
1386 	    (flags & MSG_OOB) ? PRUS_OOB :
1387 	/*
1388 	 * If the user set MSG_EOF, the protocol understands this flag and
1389 	 * nothing left to send then use PRU_SEND_EOF instead of PRU_SEND.
1390 	 */
1391 	    ((flags & MSG_EOF) &&
1392 	     (so->so_proto->pr_flags & PR_IMPLOPCL) &&
1393 	     (resid <= 0)) ?
1394 		PRUS_EOF :
1395 		/* If there is more to send set PRUS_MORETOCOME */
1396 		(flags & MSG_MORETOCOME) ||
1397 		(resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
1398 		top, addr, control, td);
1399 	if (dontroute) {
1400 		SOCK_LOCK(so);
1401 		so->so_options &= ~SO_DONTROUTE;
1402 		SOCK_UNLOCK(so);
1403 	}
1404 	clen = 0;
1405 	control = NULL;
1406 	top = NULL;
1407 out:
1408 	if (top != NULL)
1409 		m_freem(top);
1410 	if (control != NULL)
1411 		m_freem(control);
1412 	return (error);
1413 }
1414 
1415 /*
1416  * Send on a socket.  If send must go all at once and message is larger than
1417  * send buffering, then hard error.  Lock against other senders.  If must go
1418  * all at once and not enough room now, then inform user that this would
1419  * block and do nothing.  Otherwise, if nonblocking, send as much as
1420  * possible.  The data to be sent is described by "uio" if nonzero, otherwise
1421  * by the mbuf chain "top" (which must be null if uio is not).  Data provided
1422  * in mbuf chain must be small enough to send all at once.
1423  *
1424  * Returns nonzero on error, timeout or signal; callers must check for short
1425  * counts if EINTR/ERESTART are returned.  Data and control buffers are freed
1426  * on return.
1427  */
1428 int
1429 sosend_generic(struct socket *so, struct sockaddr *addr, struct uio *uio,
1430     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
1431 {
1432 	long space;
1433 	ssize_t resid;
1434 	int clen = 0, error, dontroute;
1435 	int atomic = sosendallatonce(so) || top;
1436 
1437 	if (uio != NULL)
1438 		resid = uio->uio_resid;
1439 	else
1440 		resid = top->m_pkthdr.len;
1441 	/*
1442 	 * In theory resid should be unsigned.  However, space must be
1443 	 * signed, as it might be less than 0 if we over-committed, and we
1444 	 * must use a signed comparison of space and resid.  On the other
1445 	 * hand, a negative resid causes us to loop sending 0-length
1446 	 * segments to the protocol.
1447 	 *
1448 	 * Also check to make sure that MSG_EOR isn't used on SOCK_STREAM
1449 	 * type sockets since that's an error.
1450 	 */
1451 	if (resid < 0 || (so->so_type == SOCK_STREAM && (flags & MSG_EOR))) {
1452 		error = EINVAL;
1453 		goto out;
1454 	}
1455 
1456 	dontroute =
1457 	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
1458 	    (so->so_proto->pr_flags & PR_ATOMIC);
1459 	if (td != NULL)
1460 		td->td_ru.ru_msgsnd++;
1461 	if (control != NULL)
1462 		clen = control->m_len;
1463 
1464 	error = sblock(&so->so_snd, SBLOCKWAIT(flags));
1465 	if (error)
1466 		goto out;
1467 
1468 restart:
1469 	do {
1470 		SOCKBUF_LOCK(&so->so_snd);
1471 		if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
1472 			SOCKBUF_UNLOCK(&so->so_snd);
1473 			error = EPIPE;
1474 			goto release;
1475 		}
1476 		if (so->so_error) {
1477 			error = so->so_error;
1478 			so->so_error = 0;
1479 			SOCKBUF_UNLOCK(&so->so_snd);
1480 			goto release;
1481 		}
1482 		if ((so->so_state & SS_ISCONNECTED) == 0) {
1483 			/*
1484 			 * `sendto' and `sendmsg' is allowed on a connection-
1485 			 * based socket if it supports implied connect.
1486 			 * Return ENOTCONN if not connected and no address is
1487 			 * supplied.
1488 			 */
1489 			if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
1490 			    (so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
1491 				if ((so->so_state & SS_ISCONFIRMING) == 0 &&
1492 				    !(resid == 0 && clen != 0)) {
1493 					SOCKBUF_UNLOCK(&so->so_snd);
1494 					error = ENOTCONN;
1495 					goto release;
1496 				}
1497 			} else if (addr == NULL) {
1498 				SOCKBUF_UNLOCK(&so->so_snd);
1499 				if (so->so_proto->pr_flags & PR_CONNREQUIRED)
1500 					error = ENOTCONN;
1501 				else
1502 					error = EDESTADDRREQ;
1503 				goto release;
1504 			}
1505 		}
1506 		space = sbspace(&so->so_snd);
1507 		if (flags & MSG_OOB)
1508 			space += 1024;
1509 		if ((atomic && resid > so->so_snd.sb_hiwat) ||
1510 		    clen > so->so_snd.sb_hiwat) {
1511 			SOCKBUF_UNLOCK(&so->so_snd);
1512 			error = EMSGSIZE;
1513 			goto release;
1514 		}
1515 		if (space < resid + clen &&
1516 		    (atomic || space < so->so_snd.sb_lowat || space < clen)) {
1517 			if ((so->so_state & SS_NBIO) || (flags & MSG_NBIO)) {
1518 				SOCKBUF_UNLOCK(&so->so_snd);
1519 				error = EWOULDBLOCK;
1520 				goto release;
1521 			}
1522 			error = sbwait(&so->so_snd);
1523 			SOCKBUF_UNLOCK(&so->so_snd);
1524 			if (error)
1525 				goto release;
1526 			goto restart;
1527 		}
1528 		SOCKBUF_UNLOCK(&so->so_snd);
1529 		space -= clen;
1530 		do {
1531 			if (uio == NULL) {
1532 				resid = 0;
1533 				if (flags & MSG_EOR)
1534 					top->m_flags |= M_EOR;
1535 			} else {
1536 				/*
1537 				 * Copy the data from userland into a mbuf
1538 				 * chain.  If resid is 0, which can happen
1539 				 * only if we have control to send, then
1540 				 * a single empty mbuf is returned.  This
1541 				 * is a workaround to prevent protocol send
1542 				 * methods to panic.
1543 				 */
1544 				top = m_uiotombuf(uio, M_WAITOK, space,
1545 				    (atomic ? max_hdr : 0),
1546 				    (atomic ? M_PKTHDR : 0) |
1547 				    ((flags & MSG_EOR) ? M_EOR : 0));
1548 				if (top == NULL) {
1549 					error = EFAULT; /* only possible error */
1550 					goto release;
1551 				}
1552 				space -= resid - uio->uio_resid;
1553 				resid = uio->uio_resid;
1554 			}
1555 			if (dontroute) {
1556 				SOCK_LOCK(so);
1557 				so->so_options |= SO_DONTROUTE;
1558 				SOCK_UNLOCK(so);
1559 			}
1560 			/*
1561 			 * XXX all the SBS_CANTSENDMORE checks previously
1562 			 * done could be out of date.  We could have received
1563 			 * a reset packet in an interrupt or maybe we slept
1564 			 * while doing page faults in uiomove() etc.  We
1565 			 * could probably recheck again inside the locking
1566 			 * protection here, but there are probably other
1567 			 * places that this also happens.  We must rethink
1568 			 * this.
1569 			 */
1570 			VNET_SO_ASSERT(so);
1571 			error = (*so->so_proto->pr_usrreqs->pru_send)(so,
1572 			    (flags & MSG_OOB) ? PRUS_OOB :
1573 			/*
1574 			 * If the user set MSG_EOF, the protocol understands
1575 			 * this flag and nothing left to send then use
1576 			 * PRU_SEND_EOF instead of PRU_SEND.
1577 			 */
1578 			    ((flags & MSG_EOF) &&
1579 			     (so->so_proto->pr_flags & PR_IMPLOPCL) &&
1580 			     (resid <= 0)) ?
1581 				PRUS_EOF :
1582 			/* If there is more to send set PRUS_MORETOCOME. */
1583 			    (flags & MSG_MORETOCOME) ||
1584 			    (resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
1585 			    top, addr, control, td);
1586 			if (dontroute) {
1587 				SOCK_LOCK(so);
1588 				so->so_options &= ~SO_DONTROUTE;
1589 				SOCK_UNLOCK(so);
1590 			}
1591 			clen = 0;
1592 			control = NULL;
1593 			top = NULL;
1594 			if (error)
1595 				goto release;
1596 		} while (resid && space > 0);
1597 	} while (resid);
1598 
1599 release:
1600 	sbunlock(&so->so_snd);
1601 out:
1602 	if (top != NULL)
1603 		m_freem(top);
1604 	if (control != NULL)
1605 		m_freem(control);
1606 	return (error);
1607 }
1608 
1609 int
1610 sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
1611     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
1612 {
1613 	int error;
1614 
1615 	CURVNET_SET(so->so_vnet);
1616 	if (!SOLISTENING(so))
1617 		error = so->so_proto->pr_usrreqs->pru_sosend(so, addr, uio,
1618 		    top, control, flags, td);
1619 	else {
1620 		m_freem(top);
1621 		m_freem(control);
1622 		error = ENOTCONN;
1623 	}
1624 	CURVNET_RESTORE();
1625 	return (error);
1626 }
1627 
1628 /*
1629  * The part of soreceive() that implements reading non-inline out-of-band
1630  * data from a socket.  For more complete comments, see soreceive(), from
1631  * which this code originated.
1632  *
1633  * Note that soreceive_rcvoob(), unlike the remainder of soreceive(), is
1634  * unable to return an mbuf chain to the caller.
1635  */
1636 static int
1637 soreceive_rcvoob(struct socket *so, struct uio *uio, int flags)
1638 {
1639 	struct protosw *pr = so->so_proto;
1640 	struct mbuf *m;
1641 	int error;
1642 
1643 	KASSERT(flags & MSG_OOB, ("soreceive_rcvoob: (flags & MSG_OOB) == 0"));
1644 	VNET_SO_ASSERT(so);
1645 
1646 	m = m_get(M_WAITOK, MT_DATA);
1647 	error = (*pr->pr_usrreqs->pru_rcvoob)(so, m, flags & MSG_PEEK);
1648 	if (error)
1649 		goto bad;
1650 	do {
1651 		error = uiomove(mtod(m, void *),
1652 		    (int) min(uio->uio_resid, m->m_len), uio);
1653 		m = m_free(m);
1654 	} while (uio->uio_resid && error == 0 && m);
1655 bad:
1656 	if (m != NULL)
1657 		m_freem(m);
1658 	return (error);
1659 }
1660 
1661 /*
1662  * Following replacement or removal of the first mbuf on the first mbuf chain
1663  * of a socket buffer, push necessary state changes back into the socket
1664  * buffer so that other consumers see the values consistently.  'nextrecord'
1665  * is the callers locally stored value of the original value of
1666  * sb->sb_mb->m_nextpkt which must be restored when the lead mbuf changes.
1667  * NOTE: 'nextrecord' may be NULL.
1668  */
1669 static __inline void
1670 sockbuf_pushsync(struct sockbuf *sb, struct mbuf *nextrecord)
1671 {
1672 
1673 	SOCKBUF_LOCK_ASSERT(sb);
1674 	/*
1675 	 * First, update for the new value of nextrecord.  If necessary, make
1676 	 * it the first record.
1677 	 */
1678 	if (sb->sb_mb != NULL)
1679 		sb->sb_mb->m_nextpkt = nextrecord;
1680 	else
1681 		sb->sb_mb = nextrecord;
1682 
1683 	/*
1684 	 * Now update any dependent socket buffer fields to reflect the new
1685 	 * state.  This is an expanded inline of SB_EMPTY_FIXUP(), with the
1686 	 * addition of a second clause that takes care of the case where
1687 	 * sb_mb has been updated, but remains the last record.
1688 	 */
1689 	if (sb->sb_mb == NULL) {
1690 		sb->sb_mbtail = NULL;
1691 		sb->sb_lastrecord = NULL;
1692 	} else if (sb->sb_mb->m_nextpkt == NULL)
1693 		sb->sb_lastrecord = sb->sb_mb;
1694 }
1695 
1696 /*
1697  * Implement receive operations on a socket.  We depend on the way that
1698  * records are added to the sockbuf by sbappend.  In particular, each record
1699  * (mbufs linked through m_next) must begin with an address if the protocol
1700  * so specifies, followed by an optional mbuf or mbufs containing ancillary
1701  * data, and then zero or more mbufs of data.  In order to allow parallelism
1702  * between network receive and copying to user space, as well as avoid
1703  * sleeping with a mutex held, we release the socket buffer mutex during the
1704  * user space copy.  Although the sockbuf is locked, new data may still be
1705  * appended, and thus we must maintain consistency of the sockbuf during that
1706  * time.
1707  *
1708  * The caller may receive the data as a single mbuf chain by supplying an
1709  * mbuf **mp0 for use in returning the chain.  The uio is then used only for
1710  * the count in uio_resid.
1711  */
1712 int
1713 soreceive_generic(struct socket *so, struct sockaddr **psa, struct uio *uio,
1714     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
1715 {
1716 	struct mbuf *m, **mp;
1717 	int flags, error, offset;
1718 	ssize_t len;
1719 	struct protosw *pr = so->so_proto;
1720 	struct mbuf *nextrecord;
1721 	int moff, type = 0;
1722 	ssize_t orig_resid = uio->uio_resid;
1723 
1724 	mp = mp0;
1725 	if (psa != NULL)
1726 		*psa = NULL;
1727 	if (controlp != NULL)
1728 		*controlp = NULL;
1729 	if (flagsp != NULL)
1730 		flags = *flagsp &~ MSG_EOR;
1731 	else
1732 		flags = 0;
1733 	if (flags & MSG_OOB)
1734 		return (soreceive_rcvoob(so, uio, flags));
1735 	if (mp != NULL)
1736 		*mp = NULL;
1737 	if ((pr->pr_flags & PR_WANTRCVD) && (so->so_state & SS_ISCONFIRMING)
1738 	    && uio->uio_resid) {
1739 		VNET_SO_ASSERT(so);
1740 		(*pr->pr_usrreqs->pru_rcvd)(so, 0);
1741 	}
1742 
1743 	error = sblock(&so->so_rcv, SBLOCKWAIT(flags));
1744 	if (error)
1745 		return (error);
1746 
1747 restart:
1748 	SOCKBUF_LOCK(&so->so_rcv);
1749 	m = so->so_rcv.sb_mb;
1750 	/*
1751 	 * If we have less data than requested, block awaiting more (subject
1752 	 * to any timeout) if:
1753 	 *   1. the current count is less than the low water mark, or
1754 	 *   2. MSG_DONTWAIT is not set
1755 	 */
1756 	if (m == NULL || (((flags & MSG_DONTWAIT) == 0 &&
1757 	    sbavail(&so->so_rcv) < uio->uio_resid) &&
1758 	    sbavail(&so->so_rcv) < so->so_rcv.sb_lowat &&
1759 	    m->m_nextpkt == NULL && (pr->pr_flags & PR_ATOMIC) == 0)) {
1760 		KASSERT(m != NULL || !sbavail(&so->so_rcv),
1761 		    ("receive: m == %p sbavail == %u",
1762 		    m, sbavail(&so->so_rcv)));
1763 		if (so->so_error) {
1764 			if (m != NULL)
1765 				goto dontblock;
1766 			error = so->so_error;
1767 			if ((flags & MSG_PEEK) == 0)
1768 				so->so_error = 0;
1769 			SOCKBUF_UNLOCK(&so->so_rcv);
1770 			goto release;
1771 		}
1772 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1773 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
1774 			if (m == NULL) {
1775 				SOCKBUF_UNLOCK(&so->so_rcv);
1776 				goto release;
1777 			} else
1778 				goto dontblock;
1779 		}
1780 		for (; m != NULL; m = m->m_next)
1781 			if (m->m_type == MT_OOBDATA  || (m->m_flags & M_EOR)) {
1782 				m = so->so_rcv.sb_mb;
1783 				goto dontblock;
1784 			}
1785 		if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
1786 		    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
1787 			SOCKBUF_UNLOCK(&so->so_rcv);
1788 			error = ENOTCONN;
1789 			goto release;
1790 		}
1791 		if (uio->uio_resid == 0) {
1792 			SOCKBUF_UNLOCK(&so->so_rcv);
1793 			goto release;
1794 		}
1795 		if ((so->so_state & SS_NBIO) ||
1796 		    (flags & (MSG_DONTWAIT|MSG_NBIO))) {
1797 			SOCKBUF_UNLOCK(&so->so_rcv);
1798 			error = EWOULDBLOCK;
1799 			goto release;
1800 		}
1801 		SBLASTRECORDCHK(&so->so_rcv);
1802 		SBLASTMBUFCHK(&so->so_rcv);
1803 		error = sbwait(&so->so_rcv);
1804 		SOCKBUF_UNLOCK(&so->so_rcv);
1805 		if (error)
1806 			goto release;
1807 		goto restart;
1808 	}
1809 dontblock:
1810 	/*
1811 	 * From this point onward, we maintain 'nextrecord' as a cache of the
1812 	 * pointer to the next record in the socket buffer.  We must keep the
1813 	 * various socket buffer pointers and local stack versions of the
1814 	 * pointers in sync, pushing out modifications before dropping the
1815 	 * socket buffer mutex, and re-reading them when picking it up.
1816 	 *
1817 	 * Otherwise, we will race with the network stack appending new data
1818 	 * or records onto the socket buffer by using inconsistent/stale
1819 	 * versions of the field, possibly resulting in socket buffer
1820 	 * corruption.
1821 	 *
1822 	 * By holding the high-level sblock(), we prevent simultaneous
1823 	 * readers from pulling off the front of the socket buffer.
1824 	 */
1825 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1826 	if (uio->uio_td)
1827 		uio->uio_td->td_ru.ru_msgrcv++;
1828 	KASSERT(m == so->so_rcv.sb_mb, ("soreceive: m != so->so_rcv.sb_mb"));
1829 	SBLASTRECORDCHK(&so->so_rcv);
1830 	SBLASTMBUFCHK(&so->so_rcv);
1831 	nextrecord = m->m_nextpkt;
1832 	if (pr->pr_flags & PR_ADDR) {
1833 		KASSERT(m->m_type == MT_SONAME,
1834 		    ("m->m_type == %d", m->m_type));
1835 		orig_resid = 0;
1836 		if (psa != NULL)
1837 			*psa = sodupsockaddr(mtod(m, struct sockaddr *),
1838 			    M_NOWAIT);
1839 		if (flags & MSG_PEEK) {
1840 			m = m->m_next;
1841 		} else {
1842 			sbfree(&so->so_rcv, m);
1843 			so->so_rcv.sb_mb = m_free(m);
1844 			m = so->so_rcv.sb_mb;
1845 			sockbuf_pushsync(&so->so_rcv, nextrecord);
1846 		}
1847 	}
1848 
1849 	/*
1850 	 * Process one or more MT_CONTROL mbufs present before any data mbufs
1851 	 * in the first mbuf chain on the socket buffer.  If MSG_PEEK, we
1852 	 * just copy the data; if !MSG_PEEK, we call into the protocol to
1853 	 * perform externalization (or freeing if controlp == NULL).
1854 	 */
1855 	if (m != NULL && m->m_type == MT_CONTROL) {
1856 		struct mbuf *cm = NULL, *cmn;
1857 		struct mbuf **cme = &cm;
1858 
1859 		do {
1860 			if (flags & MSG_PEEK) {
1861 				if (controlp != NULL) {
1862 					*controlp = m_copym(m, 0, m->m_len,
1863 					    M_NOWAIT);
1864 					controlp = &(*controlp)->m_next;
1865 				}
1866 				m = m->m_next;
1867 			} else {
1868 				sbfree(&so->so_rcv, m);
1869 				so->so_rcv.sb_mb = m->m_next;
1870 				m->m_next = NULL;
1871 				*cme = m;
1872 				cme = &(*cme)->m_next;
1873 				m = so->so_rcv.sb_mb;
1874 			}
1875 		} while (m != NULL && m->m_type == MT_CONTROL);
1876 		if ((flags & MSG_PEEK) == 0)
1877 			sockbuf_pushsync(&so->so_rcv, nextrecord);
1878 		while (cm != NULL) {
1879 			cmn = cm->m_next;
1880 			cm->m_next = NULL;
1881 			if (pr->pr_domain->dom_externalize != NULL) {
1882 				SOCKBUF_UNLOCK(&so->so_rcv);
1883 				VNET_SO_ASSERT(so);
1884 				error = (*pr->pr_domain->dom_externalize)
1885 				    (cm, controlp, flags);
1886 				SOCKBUF_LOCK(&so->so_rcv);
1887 			} else if (controlp != NULL)
1888 				*controlp = cm;
1889 			else
1890 				m_freem(cm);
1891 			if (controlp != NULL) {
1892 				orig_resid = 0;
1893 				while (*controlp != NULL)
1894 					controlp = &(*controlp)->m_next;
1895 			}
1896 			cm = cmn;
1897 		}
1898 		if (m != NULL)
1899 			nextrecord = so->so_rcv.sb_mb->m_nextpkt;
1900 		else
1901 			nextrecord = so->so_rcv.sb_mb;
1902 		orig_resid = 0;
1903 	}
1904 	if (m != NULL) {
1905 		if ((flags & MSG_PEEK) == 0) {
1906 			KASSERT(m->m_nextpkt == nextrecord,
1907 			    ("soreceive: post-control, nextrecord !sync"));
1908 			if (nextrecord == NULL) {
1909 				KASSERT(so->so_rcv.sb_mb == m,
1910 				    ("soreceive: post-control, sb_mb!=m"));
1911 				KASSERT(so->so_rcv.sb_lastrecord == m,
1912 				    ("soreceive: post-control, lastrecord!=m"));
1913 			}
1914 		}
1915 		type = m->m_type;
1916 		if (type == MT_OOBDATA)
1917 			flags |= MSG_OOB;
1918 	} else {
1919 		if ((flags & MSG_PEEK) == 0) {
1920 			KASSERT(so->so_rcv.sb_mb == nextrecord,
1921 			    ("soreceive: sb_mb != nextrecord"));
1922 			if (so->so_rcv.sb_mb == NULL) {
1923 				KASSERT(so->so_rcv.sb_lastrecord == NULL,
1924 				    ("soreceive: sb_lastercord != NULL"));
1925 			}
1926 		}
1927 	}
1928 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1929 	SBLASTRECORDCHK(&so->so_rcv);
1930 	SBLASTMBUFCHK(&so->so_rcv);
1931 
1932 	/*
1933 	 * Now continue to read any data mbufs off of the head of the socket
1934 	 * buffer until the read request is satisfied.  Note that 'type' is
1935 	 * used to store the type of any mbuf reads that have happened so far
1936 	 * such that soreceive() can stop reading if the type changes, which
1937 	 * causes soreceive() to return only one of regular data and inline
1938 	 * out-of-band data in a single socket receive operation.
1939 	 */
1940 	moff = 0;
1941 	offset = 0;
1942 	while (m != NULL && !(m->m_flags & M_NOTAVAIL) && uio->uio_resid > 0
1943 	    && error == 0) {
1944 		/*
1945 		 * If the type of mbuf has changed since the last mbuf
1946 		 * examined ('type'), end the receive operation.
1947 		 */
1948 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1949 		if (m->m_type == MT_OOBDATA || m->m_type == MT_CONTROL) {
1950 			if (type != m->m_type)
1951 				break;
1952 		} else if (type == MT_OOBDATA)
1953 			break;
1954 		else
1955 		    KASSERT(m->m_type == MT_DATA,
1956 			("m->m_type == %d", m->m_type));
1957 		so->so_rcv.sb_state &= ~SBS_RCVATMARK;
1958 		len = uio->uio_resid;
1959 		if (so->so_oobmark && len > so->so_oobmark - offset)
1960 			len = so->so_oobmark - offset;
1961 		if (len > m->m_len - moff)
1962 			len = m->m_len - moff;
1963 		/*
1964 		 * If mp is set, just pass back the mbufs.  Otherwise copy
1965 		 * them out via the uio, then free.  Sockbuf must be
1966 		 * consistent here (points to current mbuf, it points to next
1967 		 * record) when we drop priority; we must note any additions
1968 		 * to the sockbuf when we block interrupts again.
1969 		 */
1970 		if (mp == NULL) {
1971 			SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1972 			SBLASTRECORDCHK(&so->so_rcv);
1973 			SBLASTMBUFCHK(&so->so_rcv);
1974 			SOCKBUF_UNLOCK(&so->so_rcv);
1975 			error = uiomove(mtod(m, char *) + moff, (int)len, uio);
1976 			SOCKBUF_LOCK(&so->so_rcv);
1977 			if (error) {
1978 				/*
1979 				 * The MT_SONAME mbuf has already been removed
1980 				 * from the record, so it is necessary to
1981 				 * remove the data mbufs, if any, to preserve
1982 				 * the invariant in the case of PR_ADDR that
1983 				 * requires MT_SONAME mbufs at the head of
1984 				 * each record.
1985 				 */
1986 				if (pr->pr_flags & PR_ATOMIC &&
1987 				    ((flags & MSG_PEEK) == 0))
1988 					(void)sbdroprecord_locked(&so->so_rcv);
1989 				SOCKBUF_UNLOCK(&so->so_rcv);
1990 				goto release;
1991 			}
1992 		} else
1993 			uio->uio_resid -= len;
1994 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1995 		if (len == m->m_len - moff) {
1996 			if (m->m_flags & M_EOR)
1997 				flags |= MSG_EOR;
1998 			if (flags & MSG_PEEK) {
1999 				m = m->m_next;
2000 				moff = 0;
2001 			} else {
2002 				nextrecord = m->m_nextpkt;
2003 				sbfree(&so->so_rcv, m);
2004 				if (mp != NULL) {
2005 					m->m_nextpkt = NULL;
2006 					*mp = m;
2007 					mp = &m->m_next;
2008 					so->so_rcv.sb_mb = m = m->m_next;
2009 					*mp = NULL;
2010 				} else {
2011 					so->so_rcv.sb_mb = m_free(m);
2012 					m = so->so_rcv.sb_mb;
2013 				}
2014 				sockbuf_pushsync(&so->so_rcv, nextrecord);
2015 				SBLASTRECORDCHK(&so->so_rcv);
2016 				SBLASTMBUFCHK(&so->so_rcv);
2017 			}
2018 		} else {
2019 			if (flags & MSG_PEEK)
2020 				moff += len;
2021 			else {
2022 				if (mp != NULL) {
2023 					if (flags & MSG_DONTWAIT) {
2024 						*mp = m_copym(m, 0, len,
2025 						    M_NOWAIT);
2026 						if (*mp == NULL) {
2027 							/*
2028 							 * m_copym() couldn't
2029 							 * allocate an mbuf.
2030 							 * Adjust uio_resid back
2031 							 * (it was adjusted
2032 							 * down by len bytes,
2033 							 * which we didn't end
2034 							 * up "copying" over).
2035 							 */
2036 							uio->uio_resid += len;
2037 							break;
2038 						}
2039 					} else {
2040 						SOCKBUF_UNLOCK(&so->so_rcv);
2041 						*mp = m_copym(m, 0, len,
2042 						    M_WAITOK);
2043 						SOCKBUF_LOCK(&so->so_rcv);
2044 					}
2045 				}
2046 				sbcut_locked(&so->so_rcv, len);
2047 			}
2048 		}
2049 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2050 		if (so->so_oobmark) {
2051 			if ((flags & MSG_PEEK) == 0) {
2052 				so->so_oobmark -= len;
2053 				if (so->so_oobmark == 0) {
2054 					so->so_rcv.sb_state |= SBS_RCVATMARK;
2055 					break;
2056 				}
2057 			} else {
2058 				offset += len;
2059 				if (offset == so->so_oobmark)
2060 					break;
2061 			}
2062 		}
2063 		if (flags & MSG_EOR)
2064 			break;
2065 		/*
2066 		 * If the MSG_WAITALL flag is set (for non-atomic socket), we
2067 		 * must not quit until "uio->uio_resid == 0" or an error
2068 		 * termination.  If a signal/timeout occurs, return with a
2069 		 * short count but without error.  Keep sockbuf locked
2070 		 * against other readers.
2071 		 */
2072 		while (flags & MSG_WAITALL && m == NULL && uio->uio_resid > 0 &&
2073 		    !sosendallatonce(so) && nextrecord == NULL) {
2074 			SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2075 			if (so->so_error ||
2076 			    so->so_rcv.sb_state & SBS_CANTRCVMORE)
2077 				break;
2078 			/*
2079 			 * Notify the protocol that some data has been
2080 			 * drained before blocking.
2081 			 */
2082 			if (pr->pr_flags & PR_WANTRCVD) {
2083 				SOCKBUF_UNLOCK(&so->so_rcv);
2084 				VNET_SO_ASSERT(so);
2085 				(*pr->pr_usrreqs->pru_rcvd)(so, flags);
2086 				SOCKBUF_LOCK(&so->so_rcv);
2087 			}
2088 			SBLASTRECORDCHK(&so->so_rcv);
2089 			SBLASTMBUFCHK(&so->so_rcv);
2090 			/*
2091 			 * We could receive some data while was notifying
2092 			 * the protocol. Skip blocking in this case.
2093 			 */
2094 			if (so->so_rcv.sb_mb == NULL) {
2095 				error = sbwait(&so->so_rcv);
2096 				if (error) {
2097 					SOCKBUF_UNLOCK(&so->so_rcv);
2098 					goto release;
2099 				}
2100 			}
2101 			m = so->so_rcv.sb_mb;
2102 			if (m != NULL)
2103 				nextrecord = m->m_nextpkt;
2104 		}
2105 	}
2106 
2107 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2108 	if (m != NULL && pr->pr_flags & PR_ATOMIC) {
2109 		flags |= MSG_TRUNC;
2110 		if ((flags & MSG_PEEK) == 0)
2111 			(void) sbdroprecord_locked(&so->so_rcv);
2112 	}
2113 	if ((flags & MSG_PEEK) == 0) {
2114 		if (m == NULL) {
2115 			/*
2116 			 * First part is an inline SB_EMPTY_FIXUP().  Second
2117 			 * part makes sure sb_lastrecord is up-to-date if
2118 			 * there is still data in the socket buffer.
2119 			 */
2120 			so->so_rcv.sb_mb = nextrecord;
2121 			if (so->so_rcv.sb_mb == NULL) {
2122 				so->so_rcv.sb_mbtail = NULL;
2123 				so->so_rcv.sb_lastrecord = NULL;
2124 			} else if (nextrecord->m_nextpkt == NULL)
2125 				so->so_rcv.sb_lastrecord = nextrecord;
2126 		}
2127 		SBLASTRECORDCHK(&so->so_rcv);
2128 		SBLASTMBUFCHK(&so->so_rcv);
2129 		/*
2130 		 * If soreceive() is being done from the socket callback,
2131 		 * then don't need to generate ACK to peer to update window,
2132 		 * since ACK will be generated on return to TCP.
2133 		 */
2134 		if (!(flags & MSG_SOCALLBCK) &&
2135 		    (pr->pr_flags & PR_WANTRCVD)) {
2136 			SOCKBUF_UNLOCK(&so->so_rcv);
2137 			VNET_SO_ASSERT(so);
2138 			(*pr->pr_usrreqs->pru_rcvd)(so, flags);
2139 			SOCKBUF_LOCK(&so->so_rcv);
2140 		}
2141 	}
2142 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2143 	if (orig_resid == uio->uio_resid && orig_resid &&
2144 	    (flags & MSG_EOR) == 0 && (so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0) {
2145 		SOCKBUF_UNLOCK(&so->so_rcv);
2146 		goto restart;
2147 	}
2148 	SOCKBUF_UNLOCK(&so->so_rcv);
2149 
2150 	if (flagsp != NULL)
2151 		*flagsp |= flags;
2152 release:
2153 	sbunlock(&so->so_rcv);
2154 	return (error);
2155 }
2156 
2157 /*
2158  * Optimized version of soreceive() for stream (TCP) sockets.
2159  * XXXAO: (MSG_WAITALL | MSG_PEEK) isn't properly handled.
2160  */
2161 int
2162 soreceive_stream(struct socket *so, struct sockaddr **psa, struct uio *uio,
2163     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2164 {
2165 	int len = 0, error = 0, flags, oresid;
2166 	struct sockbuf *sb;
2167 	struct mbuf *m, *n = NULL;
2168 
2169 	/* We only do stream sockets. */
2170 	if (so->so_type != SOCK_STREAM)
2171 		return (EINVAL);
2172 	if (psa != NULL)
2173 		*psa = NULL;
2174 	if (controlp != NULL)
2175 		return (EINVAL);
2176 	if (flagsp != NULL)
2177 		flags = *flagsp &~ MSG_EOR;
2178 	else
2179 		flags = 0;
2180 	if (flags & MSG_OOB)
2181 		return (soreceive_rcvoob(so, uio, flags));
2182 	if (mp0 != NULL)
2183 		*mp0 = NULL;
2184 
2185 	sb = &so->so_rcv;
2186 
2187 	/* Prevent other readers from entering the socket. */
2188 	error = sblock(sb, SBLOCKWAIT(flags));
2189 	if (error)
2190 		goto out;
2191 	SOCKBUF_LOCK(sb);
2192 
2193 	/* Easy one, no space to copyout anything. */
2194 	if (uio->uio_resid == 0) {
2195 		error = EINVAL;
2196 		goto out;
2197 	}
2198 	oresid = uio->uio_resid;
2199 
2200 	/* We will never ever get anything unless we are or were connected. */
2201 	if (!(so->so_state & (SS_ISCONNECTED|SS_ISDISCONNECTED))) {
2202 		error = ENOTCONN;
2203 		goto out;
2204 	}
2205 
2206 restart:
2207 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2208 
2209 	/* Abort if socket has reported problems. */
2210 	if (so->so_error) {
2211 		if (sbavail(sb) > 0)
2212 			goto deliver;
2213 		if (oresid > uio->uio_resid)
2214 			goto out;
2215 		error = so->so_error;
2216 		if (!(flags & MSG_PEEK))
2217 			so->so_error = 0;
2218 		goto out;
2219 	}
2220 
2221 	/* Door is closed.  Deliver what is left, if any. */
2222 	if (sb->sb_state & SBS_CANTRCVMORE) {
2223 		if (sbavail(sb) > 0)
2224 			goto deliver;
2225 		else
2226 			goto out;
2227 	}
2228 
2229 	/* Socket buffer is empty and we shall not block. */
2230 	if (sbavail(sb) == 0 &&
2231 	    ((so->so_state & SS_NBIO) || (flags & (MSG_DONTWAIT|MSG_NBIO)))) {
2232 		error = EAGAIN;
2233 		goto out;
2234 	}
2235 
2236 	/* Socket buffer got some data that we shall deliver now. */
2237 	if (sbavail(sb) > 0 && !(flags & MSG_WAITALL) &&
2238 	    ((so->so_state & SS_NBIO) ||
2239 	     (flags & (MSG_DONTWAIT|MSG_NBIO)) ||
2240 	     sbavail(sb) >= sb->sb_lowat ||
2241 	     sbavail(sb) >= uio->uio_resid ||
2242 	     sbavail(sb) >= sb->sb_hiwat) ) {
2243 		goto deliver;
2244 	}
2245 
2246 	/* On MSG_WAITALL we must wait until all data or error arrives. */
2247 	if ((flags & MSG_WAITALL) &&
2248 	    (sbavail(sb) >= uio->uio_resid || sbavail(sb) >= sb->sb_hiwat))
2249 		goto deliver;
2250 
2251 	/*
2252 	 * Wait and block until (more) data comes in.
2253 	 * NB: Drops the sockbuf lock during wait.
2254 	 */
2255 	error = sbwait(sb);
2256 	if (error)
2257 		goto out;
2258 	goto restart;
2259 
2260 deliver:
2261 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2262 	KASSERT(sbavail(sb) > 0, ("%s: sockbuf empty", __func__));
2263 	KASSERT(sb->sb_mb != NULL, ("%s: sb_mb == NULL", __func__));
2264 
2265 	/* Statistics. */
2266 	if (uio->uio_td)
2267 		uio->uio_td->td_ru.ru_msgrcv++;
2268 
2269 	/* Fill uio until full or current end of socket buffer is reached. */
2270 	len = min(uio->uio_resid, sbavail(sb));
2271 	if (mp0 != NULL) {
2272 		/* Dequeue as many mbufs as possible. */
2273 		if (!(flags & MSG_PEEK) && len >= sb->sb_mb->m_len) {
2274 			if (*mp0 == NULL)
2275 				*mp0 = sb->sb_mb;
2276 			else
2277 				m_cat(*mp0, sb->sb_mb);
2278 			for (m = sb->sb_mb;
2279 			     m != NULL && m->m_len <= len;
2280 			     m = m->m_next) {
2281 				KASSERT(!(m->m_flags & M_NOTAVAIL),
2282 				    ("%s: m %p not available", __func__, m));
2283 				len -= m->m_len;
2284 				uio->uio_resid -= m->m_len;
2285 				sbfree(sb, m);
2286 				n = m;
2287 			}
2288 			n->m_next = NULL;
2289 			sb->sb_mb = m;
2290 			sb->sb_lastrecord = sb->sb_mb;
2291 			if (sb->sb_mb == NULL)
2292 				SB_EMPTY_FIXUP(sb);
2293 		}
2294 		/* Copy the remainder. */
2295 		if (len > 0) {
2296 			KASSERT(sb->sb_mb != NULL,
2297 			    ("%s: len > 0 && sb->sb_mb empty", __func__));
2298 
2299 			m = m_copym(sb->sb_mb, 0, len, M_NOWAIT);
2300 			if (m == NULL)
2301 				len = 0;	/* Don't flush data from sockbuf. */
2302 			else
2303 				uio->uio_resid -= len;
2304 			if (*mp0 != NULL)
2305 				m_cat(*mp0, m);
2306 			else
2307 				*mp0 = m;
2308 			if (*mp0 == NULL) {
2309 				error = ENOBUFS;
2310 				goto out;
2311 			}
2312 		}
2313 	} else {
2314 		/* NB: Must unlock socket buffer as uiomove may sleep. */
2315 		SOCKBUF_UNLOCK(sb);
2316 		error = m_mbuftouio(uio, sb->sb_mb, len);
2317 		SOCKBUF_LOCK(sb);
2318 		if (error)
2319 			goto out;
2320 	}
2321 	SBLASTRECORDCHK(sb);
2322 	SBLASTMBUFCHK(sb);
2323 
2324 	/*
2325 	 * Remove the delivered data from the socket buffer unless we
2326 	 * were only peeking.
2327 	 */
2328 	if (!(flags & MSG_PEEK)) {
2329 		if (len > 0)
2330 			sbdrop_locked(sb, len);
2331 
2332 		/* Notify protocol that we drained some data. */
2333 		if ((so->so_proto->pr_flags & PR_WANTRCVD) &&
2334 		    (((flags & MSG_WAITALL) && uio->uio_resid > 0) ||
2335 		     !(flags & MSG_SOCALLBCK))) {
2336 			SOCKBUF_UNLOCK(sb);
2337 			VNET_SO_ASSERT(so);
2338 			(*so->so_proto->pr_usrreqs->pru_rcvd)(so, flags);
2339 			SOCKBUF_LOCK(sb);
2340 		}
2341 	}
2342 
2343 	/*
2344 	 * For MSG_WAITALL we may have to loop again and wait for
2345 	 * more data to come in.
2346 	 */
2347 	if ((flags & MSG_WAITALL) && uio->uio_resid > 0)
2348 		goto restart;
2349 out:
2350 	SOCKBUF_LOCK_ASSERT(sb);
2351 	SBLASTRECORDCHK(sb);
2352 	SBLASTMBUFCHK(sb);
2353 	SOCKBUF_UNLOCK(sb);
2354 	sbunlock(sb);
2355 	return (error);
2356 }
2357 
2358 /*
2359  * Optimized version of soreceive() for simple datagram cases from userspace.
2360  * Unlike in the stream case, we're able to drop a datagram if copyout()
2361  * fails, and because we handle datagrams atomically, we don't need to use a
2362  * sleep lock to prevent I/O interlacing.
2363  */
2364 int
2365 soreceive_dgram(struct socket *so, struct sockaddr **psa, struct uio *uio,
2366     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2367 {
2368 	struct mbuf *m, *m2;
2369 	int flags, error;
2370 	ssize_t len;
2371 	struct protosw *pr = so->so_proto;
2372 	struct mbuf *nextrecord;
2373 
2374 	if (psa != NULL)
2375 		*psa = NULL;
2376 	if (controlp != NULL)
2377 		*controlp = NULL;
2378 	if (flagsp != NULL)
2379 		flags = *flagsp &~ MSG_EOR;
2380 	else
2381 		flags = 0;
2382 
2383 	/*
2384 	 * For any complicated cases, fall back to the full
2385 	 * soreceive_generic().
2386 	 */
2387 	if (mp0 != NULL || (flags & MSG_PEEK) || (flags & MSG_OOB))
2388 		return (soreceive_generic(so, psa, uio, mp0, controlp,
2389 		    flagsp));
2390 
2391 	/*
2392 	 * Enforce restrictions on use.
2393 	 */
2394 	KASSERT((pr->pr_flags & PR_WANTRCVD) == 0,
2395 	    ("soreceive_dgram: wantrcvd"));
2396 	KASSERT(pr->pr_flags & PR_ATOMIC, ("soreceive_dgram: !atomic"));
2397 	KASSERT((so->so_rcv.sb_state & SBS_RCVATMARK) == 0,
2398 	    ("soreceive_dgram: SBS_RCVATMARK"));
2399 	KASSERT((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0,
2400 	    ("soreceive_dgram: P_CONNREQUIRED"));
2401 
2402 	/*
2403 	 * Loop blocking while waiting for a datagram.
2404 	 */
2405 	SOCKBUF_LOCK(&so->so_rcv);
2406 	while ((m = so->so_rcv.sb_mb) == NULL) {
2407 		KASSERT(sbavail(&so->so_rcv) == 0,
2408 		    ("soreceive_dgram: sb_mb NULL but sbavail %u",
2409 		    sbavail(&so->so_rcv)));
2410 		if (so->so_error) {
2411 			error = so->so_error;
2412 			so->so_error = 0;
2413 			SOCKBUF_UNLOCK(&so->so_rcv);
2414 			return (error);
2415 		}
2416 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE ||
2417 		    uio->uio_resid == 0) {
2418 			SOCKBUF_UNLOCK(&so->so_rcv);
2419 			return (0);
2420 		}
2421 		if ((so->so_state & SS_NBIO) ||
2422 		    (flags & (MSG_DONTWAIT|MSG_NBIO))) {
2423 			SOCKBUF_UNLOCK(&so->so_rcv);
2424 			return (EWOULDBLOCK);
2425 		}
2426 		SBLASTRECORDCHK(&so->so_rcv);
2427 		SBLASTMBUFCHK(&so->so_rcv);
2428 		error = sbwait(&so->so_rcv);
2429 		if (error) {
2430 			SOCKBUF_UNLOCK(&so->so_rcv);
2431 			return (error);
2432 		}
2433 	}
2434 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2435 
2436 	if (uio->uio_td)
2437 		uio->uio_td->td_ru.ru_msgrcv++;
2438 	SBLASTRECORDCHK(&so->so_rcv);
2439 	SBLASTMBUFCHK(&so->so_rcv);
2440 	nextrecord = m->m_nextpkt;
2441 	if (nextrecord == NULL) {
2442 		KASSERT(so->so_rcv.sb_lastrecord == m,
2443 		    ("soreceive_dgram: lastrecord != m"));
2444 	}
2445 
2446 	KASSERT(so->so_rcv.sb_mb->m_nextpkt == nextrecord,
2447 	    ("soreceive_dgram: m_nextpkt != nextrecord"));
2448 
2449 	/*
2450 	 * Pull 'm' and its chain off the front of the packet queue.
2451 	 */
2452 	so->so_rcv.sb_mb = NULL;
2453 	sockbuf_pushsync(&so->so_rcv, nextrecord);
2454 
2455 	/*
2456 	 * Walk 'm's chain and free that many bytes from the socket buffer.
2457 	 */
2458 	for (m2 = m; m2 != NULL; m2 = m2->m_next)
2459 		sbfree(&so->so_rcv, m2);
2460 
2461 	/*
2462 	 * Do a few last checks before we let go of the lock.
2463 	 */
2464 	SBLASTRECORDCHK(&so->so_rcv);
2465 	SBLASTMBUFCHK(&so->so_rcv);
2466 	SOCKBUF_UNLOCK(&so->so_rcv);
2467 
2468 	if (pr->pr_flags & PR_ADDR) {
2469 		KASSERT(m->m_type == MT_SONAME,
2470 		    ("m->m_type == %d", m->m_type));
2471 		if (psa != NULL)
2472 			*psa = sodupsockaddr(mtod(m, struct sockaddr *),
2473 			    M_NOWAIT);
2474 		m = m_free(m);
2475 	}
2476 	if (m == NULL) {
2477 		/* XXXRW: Can this happen? */
2478 		return (0);
2479 	}
2480 
2481 	/*
2482 	 * Packet to copyout() is now in 'm' and it is disconnected from the
2483 	 * queue.
2484 	 *
2485 	 * Process one or more MT_CONTROL mbufs present before any data mbufs
2486 	 * in the first mbuf chain on the socket buffer.  We call into the
2487 	 * protocol to perform externalization (or freeing if controlp ==
2488 	 * NULL). In some cases there can be only MT_CONTROL mbufs without
2489 	 * MT_DATA mbufs.
2490 	 */
2491 	if (m->m_type == MT_CONTROL) {
2492 		struct mbuf *cm = NULL, *cmn;
2493 		struct mbuf **cme = &cm;
2494 
2495 		do {
2496 			m2 = m->m_next;
2497 			m->m_next = NULL;
2498 			*cme = m;
2499 			cme = &(*cme)->m_next;
2500 			m = m2;
2501 		} while (m != NULL && m->m_type == MT_CONTROL);
2502 		while (cm != NULL) {
2503 			cmn = cm->m_next;
2504 			cm->m_next = NULL;
2505 			if (pr->pr_domain->dom_externalize != NULL) {
2506 				error = (*pr->pr_domain->dom_externalize)
2507 				    (cm, controlp, flags);
2508 			} else if (controlp != NULL)
2509 				*controlp = cm;
2510 			else
2511 				m_freem(cm);
2512 			if (controlp != NULL) {
2513 				while (*controlp != NULL)
2514 					controlp = &(*controlp)->m_next;
2515 			}
2516 			cm = cmn;
2517 		}
2518 	}
2519 	KASSERT(m == NULL || m->m_type == MT_DATA,
2520 	    ("soreceive_dgram: !data"));
2521 	while (m != NULL && uio->uio_resid > 0) {
2522 		len = uio->uio_resid;
2523 		if (len > m->m_len)
2524 			len = m->m_len;
2525 		error = uiomove(mtod(m, char *), (int)len, uio);
2526 		if (error) {
2527 			m_freem(m);
2528 			return (error);
2529 		}
2530 		if (len == m->m_len)
2531 			m = m_free(m);
2532 		else {
2533 			m->m_data += len;
2534 			m->m_len -= len;
2535 		}
2536 	}
2537 	if (m != NULL) {
2538 		flags |= MSG_TRUNC;
2539 		m_freem(m);
2540 	}
2541 	if (flagsp != NULL)
2542 		*flagsp |= flags;
2543 	return (0);
2544 }
2545 
2546 int
2547 soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
2548     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2549 {
2550 	int error;
2551 
2552 	CURVNET_SET(so->so_vnet);
2553 	if (!SOLISTENING(so))
2554 		error = (so->so_proto->pr_usrreqs->pru_soreceive(so, psa, uio,
2555 		    mp0, controlp, flagsp));
2556 	else
2557 		error = ENOTCONN;
2558 	CURVNET_RESTORE();
2559 	return (error);
2560 }
2561 
2562 int
2563 soshutdown(struct socket *so, int how)
2564 {
2565 	struct protosw *pr = so->so_proto;
2566 	int error, soerror_enotconn;
2567 
2568 	if (!(how == SHUT_RD || how == SHUT_WR || how == SHUT_RDWR))
2569 		return (EINVAL);
2570 
2571 	soerror_enotconn = 0;
2572 	if ((so->so_state &
2573 	    (SS_ISCONNECTED | SS_ISCONNECTING | SS_ISDISCONNECTING)) == 0) {
2574 		/*
2575 		 * POSIX mandates us to return ENOTCONN when shutdown(2) is
2576 		 * invoked on a datagram sockets, however historically we would
2577 		 * actually tear socket down. This is known to be leveraged by
2578 		 * some applications to unblock process waiting in recvXXX(2)
2579 		 * by other process that it shares that socket with. Try to meet
2580 		 * both backward-compatibility and POSIX requirements by forcing
2581 		 * ENOTCONN but still asking protocol to perform pru_shutdown().
2582 		 */
2583 		if (so->so_type != SOCK_DGRAM)
2584 			return (ENOTCONN);
2585 		soerror_enotconn = 1;
2586 	}
2587 
2588 	CURVNET_SET(so->so_vnet);
2589 	if (pr->pr_usrreqs->pru_flush != NULL)
2590 		(*pr->pr_usrreqs->pru_flush)(so, how);
2591 	if (how != SHUT_WR)
2592 		sorflush(so);
2593 	if (how != SHUT_RD) {
2594 		error = (*pr->pr_usrreqs->pru_shutdown)(so);
2595 		wakeup(&so->so_timeo);
2596 		CURVNET_RESTORE();
2597 		return ((error == 0 && soerror_enotconn) ? ENOTCONN : error);
2598 	}
2599 	wakeup(&so->so_timeo);
2600 	CURVNET_RESTORE();
2601 
2602 	return (soerror_enotconn ? ENOTCONN : 0);
2603 }
2604 
2605 void
2606 sorflush(struct socket *so)
2607 {
2608 	struct sockbuf *sb = &so->so_rcv;
2609 	struct protosw *pr = so->so_proto;
2610 	struct socket aso;
2611 
2612 	VNET_SO_ASSERT(so);
2613 
2614 	/*
2615 	 * In order to avoid calling dom_dispose with the socket buffer mutex
2616 	 * held, and in order to generally avoid holding the lock for a long
2617 	 * time, we make a copy of the socket buffer and clear the original
2618 	 * (except locks, state).  The new socket buffer copy won't have
2619 	 * initialized locks so we can only call routines that won't use or
2620 	 * assert those locks.
2621 	 *
2622 	 * Dislodge threads currently blocked in receive and wait to acquire
2623 	 * a lock against other simultaneous readers before clearing the
2624 	 * socket buffer.  Don't let our acquire be interrupted by a signal
2625 	 * despite any existing socket disposition on interruptable waiting.
2626 	 */
2627 	socantrcvmore(so);
2628 	(void) sblock(sb, SBL_WAIT | SBL_NOINTR);
2629 
2630 	/*
2631 	 * Invalidate/clear most of the sockbuf structure, but leave selinfo
2632 	 * and mutex data unchanged.
2633 	 */
2634 	SOCKBUF_LOCK(sb);
2635 	bzero(&aso, sizeof(aso));
2636 	aso.so_pcb = so->so_pcb;
2637 	bcopy(&sb->sb_startzero, &aso.so_rcv.sb_startzero,
2638 	    sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
2639 	bzero(&sb->sb_startzero,
2640 	    sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
2641 	SOCKBUF_UNLOCK(sb);
2642 	sbunlock(sb);
2643 
2644 	/*
2645 	 * Dispose of special rights and flush the copied socket.  Don't call
2646 	 * any unsafe routines (that rely on locks being initialized) on aso.
2647 	 */
2648 	if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose != NULL)
2649 		(*pr->pr_domain->dom_dispose)(&aso);
2650 	sbrelease_internal(&aso.so_rcv, so);
2651 }
2652 
2653 /*
2654  * Wrapper for Socket established helper hook.
2655  * Parameters: socket, context of the hook point, hook id.
2656  */
2657 static int inline
2658 hhook_run_socket(struct socket *so, void *hctx, int32_t h_id)
2659 {
2660 	struct socket_hhook_data hhook_data = {
2661 		.so = so,
2662 		.hctx = hctx,
2663 		.m = NULL,
2664 		.status = 0
2665 	};
2666 
2667 	CURVNET_SET(so->so_vnet);
2668 	HHOOKS_RUN_IF(V_socket_hhh[h_id], &hhook_data, &so->osd);
2669 	CURVNET_RESTORE();
2670 
2671 	/* Ugly but needed, since hhooks return void for now */
2672 	return (hhook_data.status);
2673 }
2674 
2675 /*
2676  * Perhaps this routine, and sooptcopyout(), below, ought to come in an
2677  * additional variant to handle the case where the option value needs to be
2678  * some kind of integer, but not a specific size.  In addition to their use
2679  * here, these functions are also called by the protocol-level pr_ctloutput()
2680  * routines.
2681  */
2682 int
2683 sooptcopyin(struct sockopt *sopt, void *buf, size_t len, size_t minlen)
2684 {
2685 	size_t	valsize;
2686 
2687 	/*
2688 	 * If the user gives us more than we wanted, we ignore it, but if we
2689 	 * don't get the minimum length the caller wants, we return EINVAL.
2690 	 * On success, sopt->sopt_valsize is set to however much we actually
2691 	 * retrieved.
2692 	 */
2693 	if ((valsize = sopt->sopt_valsize) < minlen)
2694 		return EINVAL;
2695 	if (valsize > len)
2696 		sopt->sopt_valsize = valsize = len;
2697 
2698 	if (sopt->sopt_td != NULL)
2699 		return (copyin(sopt->sopt_val, buf, valsize));
2700 
2701 	bcopy(sopt->sopt_val, buf, valsize);
2702 	return (0);
2703 }
2704 
2705 /*
2706  * Kernel version of setsockopt(2).
2707  *
2708  * XXX: optlen is size_t, not socklen_t
2709  */
2710 int
2711 so_setsockopt(struct socket *so, int level, int optname, void *optval,
2712     size_t optlen)
2713 {
2714 	struct sockopt sopt;
2715 
2716 	sopt.sopt_level = level;
2717 	sopt.sopt_name = optname;
2718 	sopt.sopt_dir = SOPT_SET;
2719 	sopt.sopt_val = optval;
2720 	sopt.sopt_valsize = optlen;
2721 	sopt.sopt_td = NULL;
2722 	return (sosetopt(so, &sopt));
2723 }
2724 
2725 int
2726 sosetopt(struct socket *so, struct sockopt *sopt)
2727 {
2728 	int	error, optval;
2729 	struct	linger l;
2730 	struct	timeval tv;
2731 	sbintime_t val;
2732 	uint32_t val32;
2733 #ifdef MAC
2734 	struct mac extmac;
2735 #endif
2736 
2737 	CURVNET_SET(so->so_vnet);
2738 	error = 0;
2739 	if (sopt->sopt_level != SOL_SOCKET) {
2740 		if (so->so_proto->pr_ctloutput != NULL) {
2741 			error = (*so->so_proto->pr_ctloutput)(so, sopt);
2742 			CURVNET_RESTORE();
2743 			return (error);
2744 		}
2745 		error = ENOPROTOOPT;
2746 	} else {
2747 		switch (sopt->sopt_name) {
2748 		case SO_ACCEPTFILTER:
2749 			error = accept_filt_setopt(so, sopt);
2750 			if (error)
2751 				goto bad;
2752 			break;
2753 
2754 		case SO_LINGER:
2755 			error = sooptcopyin(sopt, &l, sizeof l, sizeof l);
2756 			if (error)
2757 				goto bad;
2758 
2759 			SOCK_LOCK(so);
2760 			so->so_linger = l.l_linger;
2761 			if (l.l_onoff)
2762 				so->so_options |= SO_LINGER;
2763 			else
2764 				so->so_options &= ~SO_LINGER;
2765 			SOCK_UNLOCK(so);
2766 			break;
2767 
2768 		case SO_DEBUG:
2769 		case SO_KEEPALIVE:
2770 		case SO_DONTROUTE:
2771 		case SO_USELOOPBACK:
2772 		case SO_BROADCAST:
2773 		case SO_REUSEADDR:
2774 		case SO_REUSEPORT:
2775 		case SO_OOBINLINE:
2776 		case SO_TIMESTAMP:
2777 		case SO_BINTIME:
2778 		case SO_NOSIGPIPE:
2779 		case SO_NO_DDP:
2780 		case SO_NO_OFFLOAD:
2781 			error = sooptcopyin(sopt, &optval, sizeof optval,
2782 			    sizeof optval);
2783 			if (error)
2784 				goto bad;
2785 			SOCK_LOCK(so);
2786 			if (optval)
2787 				so->so_options |= sopt->sopt_name;
2788 			else
2789 				so->so_options &= ~sopt->sopt_name;
2790 			SOCK_UNLOCK(so);
2791 			break;
2792 
2793 		case SO_SETFIB:
2794 			error = sooptcopyin(sopt, &optval, sizeof optval,
2795 			    sizeof optval);
2796 			if (error)
2797 				goto bad;
2798 
2799 			if (optval < 0 || optval >= rt_numfibs) {
2800 				error = EINVAL;
2801 				goto bad;
2802 			}
2803 			if (((so->so_proto->pr_domain->dom_family == PF_INET) ||
2804 			   (so->so_proto->pr_domain->dom_family == PF_INET6) ||
2805 			   (so->so_proto->pr_domain->dom_family == PF_ROUTE)))
2806 				so->so_fibnum = optval;
2807 			else
2808 				so->so_fibnum = 0;
2809 			break;
2810 
2811 		case SO_USER_COOKIE:
2812 			error = sooptcopyin(sopt, &val32, sizeof val32,
2813 			    sizeof val32);
2814 			if (error)
2815 				goto bad;
2816 			so->so_user_cookie = val32;
2817 			break;
2818 
2819 		case SO_SNDBUF:
2820 		case SO_RCVBUF:
2821 		case SO_SNDLOWAT:
2822 		case SO_RCVLOWAT:
2823 			error = sooptcopyin(sopt, &optval, sizeof optval,
2824 			    sizeof optval);
2825 			if (error)
2826 				goto bad;
2827 
2828 			/*
2829 			 * Values < 1 make no sense for any of these options,
2830 			 * so disallow them.
2831 			 */
2832 			if (optval < 1) {
2833 				error = EINVAL;
2834 				goto bad;
2835 			}
2836 
2837 			switch (sopt->sopt_name) {
2838 			case SO_SNDBUF:
2839 			case SO_RCVBUF:
2840 				if (sbreserve(sopt->sopt_name == SO_SNDBUF ?
2841 				    &so->so_snd : &so->so_rcv, (u_long)optval,
2842 				    so, curthread) == 0) {
2843 					error = ENOBUFS;
2844 					goto bad;
2845 				}
2846 				(sopt->sopt_name == SO_SNDBUF ? &so->so_snd :
2847 				    &so->so_rcv)->sb_flags &= ~SB_AUTOSIZE;
2848 				break;
2849 
2850 			/*
2851 			 * Make sure the low-water is never greater than the
2852 			 * high-water.
2853 			 */
2854 			case SO_SNDLOWAT:
2855 				SOCKBUF_LOCK(&so->so_snd);
2856 				so->so_snd.sb_lowat =
2857 				    (optval > so->so_snd.sb_hiwat) ?
2858 				    so->so_snd.sb_hiwat : optval;
2859 				SOCKBUF_UNLOCK(&so->so_snd);
2860 				break;
2861 			case SO_RCVLOWAT:
2862 				SOCKBUF_LOCK(&so->so_rcv);
2863 				so->so_rcv.sb_lowat =
2864 				    (optval > so->so_rcv.sb_hiwat) ?
2865 				    so->so_rcv.sb_hiwat : optval;
2866 				SOCKBUF_UNLOCK(&so->so_rcv);
2867 				break;
2868 			}
2869 			break;
2870 
2871 		case SO_SNDTIMEO:
2872 		case SO_RCVTIMEO:
2873 #ifdef COMPAT_FREEBSD32
2874 			if (SV_CURPROC_FLAG(SV_ILP32)) {
2875 				struct timeval32 tv32;
2876 
2877 				error = sooptcopyin(sopt, &tv32, sizeof tv32,
2878 				    sizeof tv32);
2879 				CP(tv32, tv, tv_sec);
2880 				CP(tv32, tv, tv_usec);
2881 			} else
2882 #endif
2883 				error = sooptcopyin(sopt, &tv, sizeof tv,
2884 				    sizeof tv);
2885 			if (error)
2886 				goto bad;
2887 			if (tv.tv_sec < 0 || tv.tv_usec < 0 ||
2888 			    tv.tv_usec >= 1000000) {
2889 				error = EDOM;
2890 				goto bad;
2891 			}
2892 			if (tv.tv_sec > INT32_MAX)
2893 				val = SBT_MAX;
2894 			else
2895 				val = tvtosbt(tv);
2896 			switch (sopt->sopt_name) {
2897 			case SO_SNDTIMEO:
2898 				so->so_snd.sb_timeo = val;
2899 				break;
2900 			case SO_RCVTIMEO:
2901 				so->so_rcv.sb_timeo = val;
2902 				break;
2903 			}
2904 			break;
2905 
2906 		case SO_LABEL:
2907 #ifdef MAC
2908 			error = sooptcopyin(sopt, &extmac, sizeof extmac,
2909 			    sizeof extmac);
2910 			if (error)
2911 				goto bad;
2912 			error = mac_setsockopt_label(sopt->sopt_td->td_ucred,
2913 			    so, &extmac);
2914 #else
2915 			error = EOPNOTSUPP;
2916 #endif
2917 			break;
2918 
2919 		case SO_TS_CLOCK:
2920 			error = sooptcopyin(sopt, &optval, sizeof optval,
2921 			    sizeof optval);
2922 			if (error)
2923 				goto bad;
2924 			if (optval < 0 || optval > SO_TS_CLOCK_MAX) {
2925 				error = EINVAL;
2926 				goto bad;
2927 			}
2928 			so->so_ts_clock = optval;
2929 			break;
2930 
2931 		case SO_MAX_PACING_RATE:
2932 			error = sooptcopyin(sopt, &val32, sizeof(val32),
2933 			    sizeof(val32));
2934 			if (error)
2935 				goto bad;
2936 			so->so_max_pacing_rate = val32;
2937 			break;
2938 
2939 		default:
2940 			if (V_socket_hhh[HHOOK_SOCKET_OPT]->hhh_nhooks > 0)
2941 				error = hhook_run_socket(so, sopt,
2942 				    HHOOK_SOCKET_OPT);
2943 			else
2944 				error = ENOPROTOOPT;
2945 			break;
2946 		}
2947 		if (error == 0 && so->so_proto->pr_ctloutput != NULL)
2948 			(void)(*so->so_proto->pr_ctloutput)(so, sopt);
2949 	}
2950 bad:
2951 	CURVNET_RESTORE();
2952 	return (error);
2953 }
2954 
2955 /*
2956  * Helper routine for getsockopt.
2957  */
2958 int
2959 sooptcopyout(struct sockopt *sopt, const void *buf, size_t len)
2960 {
2961 	int	error;
2962 	size_t	valsize;
2963 
2964 	error = 0;
2965 
2966 	/*
2967 	 * Documented get behavior is that we always return a value, possibly
2968 	 * truncated to fit in the user's buffer.  Traditional behavior is
2969 	 * that we always tell the user precisely how much we copied, rather
2970 	 * than something useful like the total amount we had available for
2971 	 * her.  Note that this interface is not idempotent; the entire
2972 	 * answer must be generated ahead of time.
2973 	 */
2974 	valsize = min(len, sopt->sopt_valsize);
2975 	sopt->sopt_valsize = valsize;
2976 	if (sopt->sopt_val != NULL) {
2977 		if (sopt->sopt_td != NULL)
2978 			error = copyout(buf, sopt->sopt_val, valsize);
2979 		else
2980 			bcopy(buf, sopt->sopt_val, valsize);
2981 	}
2982 	return (error);
2983 }
2984 
2985 int
2986 sogetopt(struct socket *so, struct sockopt *sopt)
2987 {
2988 	int	error, optval;
2989 	struct	linger l;
2990 	struct	timeval tv;
2991 #ifdef MAC
2992 	struct mac extmac;
2993 #endif
2994 
2995 	CURVNET_SET(so->so_vnet);
2996 	error = 0;
2997 	if (sopt->sopt_level != SOL_SOCKET) {
2998 		if (so->so_proto->pr_ctloutput != NULL)
2999 			error = (*so->so_proto->pr_ctloutput)(so, sopt);
3000 		else
3001 			error = ENOPROTOOPT;
3002 		CURVNET_RESTORE();
3003 		return (error);
3004 	} else {
3005 		switch (sopt->sopt_name) {
3006 		case SO_ACCEPTFILTER:
3007 			error = accept_filt_getopt(so, sopt);
3008 			break;
3009 
3010 		case SO_LINGER:
3011 			SOCK_LOCK(so);
3012 			l.l_onoff = so->so_options & SO_LINGER;
3013 			l.l_linger = so->so_linger;
3014 			SOCK_UNLOCK(so);
3015 			error = sooptcopyout(sopt, &l, sizeof l);
3016 			break;
3017 
3018 		case SO_USELOOPBACK:
3019 		case SO_DONTROUTE:
3020 		case SO_DEBUG:
3021 		case SO_KEEPALIVE:
3022 		case SO_REUSEADDR:
3023 		case SO_REUSEPORT:
3024 		case SO_BROADCAST:
3025 		case SO_OOBINLINE:
3026 		case SO_ACCEPTCONN:
3027 		case SO_TIMESTAMP:
3028 		case SO_BINTIME:
3029 		case SO_NOSIGPIPE:
3030 			optval = so->so_options & sopt->sopt_name;
3031 integer:
3032 			error = sooptcopyout(sopt, &optval, sizeof optval);
3033 			break;
3034 
3035 		case SO_TYPE:
3036 			optval = so->so_type;
3037 			goto integer;
3038 
3039 		case SO_PROTOCOL:
3040 			optval = so->so_proto->pr_protocol;
3041 			goto integer;
3042 
3043 		case SO_ERROR:
3044 			SOCK_LOCK(so);
3045 			optval = so->so_error;
3046 			so->so_error = 0;
3047 			SOCK_UNLOCK(so);
3048 			goto integer;
3049 
3050 		case SO_SNDBUF:
3051 			optval = so->so_snd.sb_hiwat;
3052 			goto integer;
3053 
3054 		case SO_RCVBUF:
3055 			optval = so->so_rcv.sb_hiwat;
3056 			goto integer;
3057 
3058 		case SO_SNDLOWAT:
3059 			optval = so->so_snd.sb_lowat;
3060 			goto integer;
3061 
3062 		case SO_RCVLOWAT:
3063 			optval = so->so_rcv.sb_lowat;
3064 			goto integer;
3065 
3066 		case SO_SNDTIMEO:
3067 		case SO_RCVTIMEO:
3068 			tv = sbttotv(sopt->sopt_name == SO_SNDTIMEO ?
3069 			    so->so_snd.sb_timeo : so->so_rcv.sb_timeo);
3070 #ifdef COMPAT_FREEBSD32
3071 			if (SV_CURPROC_FLAG(SV_ILP32)) {
3072 				struct timeval32 tv32;
3073 
3074 				CP(tv, tv32, tv_sec);
3075 				CP(tv, tv32, tv_usec);
3076 				error = sooptcopyout(sopt, &tv32, sizeof tv32);
3077 			} else
3078 #endif
3079 				error = sooptcopyout(sopt, &tv, sizeof tv);
3080 			break;
3081 
3082 		case SO_LABEL:
3083 #ifdef MAC
3084 			error = sooptcopyin(sopt, &extmac, sizeof(extmac),
3085 			    sizeof(extmac));
3086 			if (error)
3087 				goto bad;
3088 			error = mac_getsockopt_label(sopt->sopt_td->td_ucred,
3089 			    so, &extmac);
3090 			if (error)
3091 				goto bad;
3092 			error = sooptcopyout(sopt, &extmac, sizeof extmac);
3093 #else
3094 			error = EOPNOTSUPP;
3095 #endif
3096 			break;
3097 
3098 		case SO_PEERLABEL:
3099 #ifdef MAC
3100 			error = sooptcopyin(sopt, &extmac, sizeof(extmac),
3101 			    sizeof(extmac));
3102 			if (error)
3103 				goto bad;
3104 			error = mac_getsockopt_peerlabel(
3105 			    sopt->sopt_td->td_ucred, so, &extmac);
3106 			if (error)
3107 				goto bad;
3108 			error = sooptcopyout(sopt, &extmac, sizeof extmac);
3109 #else
3110 			error = EOPNOTSUPP;
3111 #endif
3112 			break;
3113 
3114 		case SO_LISTENQLIMIT:
3115 			optval = SOLISTENING(so) ? so->sol_qlimit : 0;
3116 			goto integer;
3117 
3118 		case SO_LISTENQLEN:
3119 			optval = SOLISTENING(so) ? so->sol_qlen : 0;
3120 			goto integer;
3121 
3122 		case SO_LISTENINCQLEN:
3123 			optval = SOLISTENING(so) ? so->sol_incqlen : 0;
3124 			goto integer;
3125 
3126 		case SO_TS_CLOCK:
3127 			optval = so->so_ts_clock;
3128 			goto integer;
3129 
3130 		case SO_MAX_PACING_RATE:
3131 			optval = so->so_max_pacing_rate;
3132 			goto integer;
3133 
3134 		default:
3135 			if (V_socket_hhh[HHOOK_SOCKET_OPT]->hhh_nhooks > 0)
3136 				error = hhook_run_socket(so, sopt,
3137 				    HHOOK_SOCKET_OPT);
3138 			else
3139 				error = ENOPROTOOPT;
3140 			break;
3141 		}
3142 	}
3143 #ifdef MAC
3144 bad:
3145 #endif
3146 	CURVNET_RESTORE();
3147 	return (error);
3148 }
3149 
3150 int
3151 soopt_getm(struct sockopt *sopt, struct mbuf **mp)
3152 {
3153 	struct mbuf *m, *m_prev;
3154 	int sopt_size = sopt->sopt_valsize;
3155 
3156 	MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
3157 	if (m == NULL)
3158 		return ENOBUFS;
3159 	if (sopt_size > MLEN) {
3160 		MCLGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT);
3161 		if ((m->m_flags & M_EXT) == 0) {
3162 			m_free(m);
3163 			return ENOBUFS;
3164 		}
3165 		m->m_len = min(MCLBYTES, sopt_size);
3166 	} else {
3167 		m->m_len = min(MLEN, sopt_size);
3168 	}
3169 	sopt_size -= m->m_len;
3170 	*mp = m;
3171 	m_prev = m;
3172 
3173 	while (sopt_size) {
3174 		MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
3175 		if (m == NULL) {
3176 			m_freem(*mp);
3177 			return ENOBUFS;
3178 		}
3179 		if (sopt_size > MLEN) {
3180 			MCLGET(m, sopt->sopt_td != NULL ? M_WAITOK :
3181 			    M_NOWAIT);
3182 			if ((m->m_flags & M_EXT) == 0) {
3183 				m_freem(m);
3184 				m_freem(*mp);
3185 				return ENOBUFS;
3186 			}
3187 			m->m_len = min(MCLBYTES, sopt_size);
3188 		} else {
3189 			m->m_len = min(MLEN, sopt_size);
3190 		}
3191 		sopt_size -= m->m_len;
3192 		m_prev->m_next = m;
3193 		m_prev = m;
3194 	}
3195 	return (0);
3196 }
3197 
3198 int
3199 soopt_mcopyin(struct sockopt *sopt, struct mbuf *m)
3200 {
3201 	struct mbuf *m0 = m;
3202 
3203 	if (sopt->sopt_val == NULL)
3204 		return (0);
3205 	while (m != NULL && sopt->sopt_valsize >= m->m_len) {
3206 		if (sopt->sopt_td != NULL) {
3207 			int error;
3208 
3209 			error = copyin(sopt->sopt_val, mtod(m, char *),
3210 			    m->m_len);
3211 			if (error != 0) {
3212 				m_freem(m0);
3213 				return(error);
3214 			}
3215 		} else
3216 			bcopy(sopt->sopt_val, mtod(m, char *), m->m_len);
3217 		sopt->sopt_valsize -= m->m_len;
3218 		sopt->sopt_val = (char *)sopt->sopt_val + m->m_len;
3219 		m = m->m_next;
3220 	}
3221 	if (m != NULL) /* should be allocated enoughly at ip6_sooptmcopyin() */
3222 		panic("ip6_sooptmcopyin");
3223 	return (0);
3224 }
3225 
3226 int
3227 soopt_mcopyout(struct sockopt *sopt, struct mbuf *m)
3228 {
3229 	struct mbuf *m0 = m;
3230 	size_t valsize = 0;
3231 
3232 	if (sopt->sopt_val == NULL)
3233 		return (0);
3234 	while (m != NULL && sopt->sopt_valsize >= m->m_len) {
3235 		if (sopt->sopt_td != NULL) {
3236 			int error;
3237 
3238 			error = copyout(mtod(m, char *), sopt->sopt_val,
3239 			    m->m_len);
3240 			if (error != 0) {
3241 				m_freem(m0);
3242 				return(error);
3243 			}
3244 		} else
3245 			bcopy(mtod(m, char *), sopt->sopt_val, m->m_len);
3246 		sopt->sopt_valsize -= m->m_len;
3247 		sopt->sopt_val = (char *)sopt->sopt_val + m->m_len;
3248 		valsize += m->m_len;
3249 		m = m->m_next;
3250 	}
3251 	if (m != NULL) {
3252 		/* enough soopt buffer should be given from user-land */
3253 		m_freem(m0);
3254 		return(EINVAL);
3255 	}
3256 	sopt->sopt_valsize = valsize;
3257 	return (0);
3258 }
3259 
3260 /*
3261  * sohasoutofband(): protocol notifies socket layer of the arrival of new
3262  * out-of-band data, which will then notify socket consumers.
3263  */
3264 void
3265 sohasoutofband(struct socket *so)
3266 {
3267 
3268 	if (so->so_sigio != NULL)
3269 		pgsigio(&so->so_sigio, SIGURG, 0);
3270 	selwakeuppri(&so->so_rdsel, PSOCK);
3271 }
3272 
3273 int
3274 sopoll(struct socket *so, int events, struct ucred *active_cred,
3275     struct thread *td)
3276 {
3277 
3278 	/*
3279 	 * We do not need to set or assert curvnet as long as everyone uses
3280 	 * sopoll_generic().
3281 	 */
3282 	return (so->so_proto->pr_usrreqs->pru_sopoll(so, events, active_cred,
3283 	    td));
3284 }
3285 
3286 int
3287 sopoll_generic(struct socket *so, int events, struct ucred *active_cred,
3288     struct thread *td)
3289 {
3290 	int revents;
3291 
3292 	SOCK_LOCK(so);
3293 	if (SOLISTENING(so)) {
3294 		if (!(events & (POLLIN | POLLRDNORM)))
3295 			revents = 0;
3296 		else if (!TAILQ_EMPTY(&so->sol_comp))
3297 			revents = events & (POLLIN | POLLRDNORM);
3298 		else {
3299 			selrecord(td, &so->so_rdsel);
3300 			revents = 0;
3301 		}
3302 	} else {
3303 		revents = 0;
3304 		SOCKBUF_LOCK(&so->so_snd);
3305 		SOCKBUF_LOCK(&so->so_rcv);
3306 		if (events & (POLLIN | POLLRDNORM))
3307 			if (soreadabledata(so))
3308 				revents |= events & (POLLIN | POLLRDNORM);
3309 		if (events & (POLLOUT | POLLWRNORM))
3310 			if (sowriteable(so))
3311 				revents |= events & (POLLOUT | POLLWRNORM);
3312 		if (events & (POLLPRI | POLLRDBAND))
3313 			if (so->so_oobmark ||
3314 			    (so->so_rcv.sb_state & SBS_RCVATMARK))
3315 				revents |= events & (POLLPRI | POLLRDBAND);
3316 		if ((events & POLLINIGNEOF) == 0) {
3317 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
3318 				revents |= events & (POLLIN | POLLRDNORM);
3319 				if (so->so_snd.sb_state & SBS_CANTSENDMORE)
3320 					revents |= POLLHUP;
3321 			}
3322 		}
3323 		if (revents == 0) {
3324 			if (events &
3325 			    (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) {
3326 				selrecord(td, &so->so_rdsel);
3327 				so->so_rcv.sb_flags |= SB_SEL;
3328 			}
3329 			if (events & (POLLOUT | POLLWRNORM)) {
3330 				selrecord(td, &so->so_wrsel);
3331 				so->so_snd.sb_flags |= SB_SEL;
3332 			}
3333 		}
3334 		SOCKBUF_UNLOCK(&so->so_rcv);
3335 		SOCKBUF_UNLOCK(&so->so_snd);
3336 	}
3337 	SOCK_UNLOCK(so);
3338 	return (revents);
3339 }
3340 
3341 int
3342 soo_kqfilter(struct file *fp, struct knote *kn)
3343 {
3344 	struct socket *so = kn->kn_fp->f_data;
3345 	struct sockbuf *sb;
3346 	struct knlist *knl;
3347 
3348 	switch (kn->kn_filter) {
3349 	case EVFILT_READ:
3350 		kn->kn_fop = &soread_filtops;
3351 		knl = &so->so_rdsel.si_note;
3352 		sb = &so->so_rcv;
3353 		break;
3354 	case EVFILT_WRITE:
3355 		kn->kn_fop = &sowrite_filtops;
3356 		knl = &so->so_wrsel.si_note;
3357 		sb = &so->so_snd;
3358 		break;
3359 	case EVFILT_EMPTY:
3360 		kn->kn_fop = &soempty_filtops;
3361 		knl = &so->so_wrsel.si_note;
3362 		sb = &so->so_snd;
3363 		break;
3364 	default:
3365 		return (EINVAL);
3366 	}
3367 
3368 	SOCK_LOCK(so);
3369 	if (SOLISTENING(so)) {
3370 		knlist_add(knl, kn, 1);
3371 	} else {
3372 		SOCKBUF_LOCK(sb);
3373 		knlist_add(knl, kn, 1);
3374 		sb->sb_flags |= SB_KNOTE;
3375 		SOCKBUF_UNLOCK(sb);
3376 	}
3377 	SOCK_UNLOCK(so);
3378 	return (0);
3379 }
3380 
3381 /*
3382  * Some routines that return EOPNOTSUPP for entry points that are not
3383  * supported by a protocol.  Fill in as needed.
3384  */
3385 int
3386 pru_accept_notsupp(struct socket *so, struct sockaddr **nam)
3387 {
3388 
3389 	return EOPNOTSUPP;
3390 }
3391 
3392 int
3393 pru_aio_queue_notsupp(struct socket *so, struct kaiocb *job)
3394 {
3395 
3396 	return EOPNOTSUPP;
3397 }
3398 
3399 int
3400 pru_attach_notsupp(struct socket *so, int proto, struct thread *td)
3401 {
3402 
3403 	return EOPNOTSUPP;
3404 }
3405 
3406 int
3407 pru_bind_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
3408 {
3409 
3410 	return EOPNOTSUPP;
3411 }
3412 
3413 int
3414 pru_bindat_notsupp(int fd, struct socket *so, struct sockaddr *nam,
3415     struct thread *td)
3416 {
3417 
3418 	return EOPNOTSUPP;
3419 }
3420 
3421 int
3422 pru_connect_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
3423 {
3424 
3425 	return EOPNOTSUPP;
3426 }
3427 
3428 int
3429 pru_connectat_notsupp(int fd, struct socket *so, struct sockaddr *nam,
3430     struct thread *td)
3431 {
3432 
3433 	return EOPNOTSUPP;
3434 }
3435 
3436 int
3437 pru_connect2_notsupp(struct socket *so1, struct socket *so2)
3438 {
3439 
3440 	return EOPNOTSUPP;
3441 }
3442 
3443 int
3444 pru_control_notsupp(struct socket *so, u_long cmd, caddr_t data,
3445     struct ifnet *ifp, struct thread *td)
3446 {
3447 
3448 	return EOPNOTSUPP;
3449 }
3450 
3451 int
3452 pru_disconnect_notsupp(struct socket *so)
3453 {
3454 
3455 	return EOPNOTSUPP;
3456 }
3457 
3458 int
3459 pru_listen_notsupp(struct socket *so, int backlog, struct thread *td)
3460 {
3461 
3462 	return EOPNOTSUPP;
3463 }
3464 
3465 int
3466 pru_peeraddr_notsupp(struct socket *so, struct sockaddr **nam)
3467 {
3468 
3469 	return EOPNOTSUPP;
3470 }
3471 
3472 int
3473 pru_rcvd_notsupp(struct socket *so, int flags)
3474 {
3475 
3476 	return EOPNOTSUPP;
3477 }
3478 
3479 int
3480 pru_rcvoob_notsupp(struct socket *so, struct mbuf *m, int flags)
3481 {
3482 
3483 	return EOPNOTSUPP;
3484 }
3485 
3486 int
3487 pru_send_notsupp(struct socket *so, int flags, struct mbuf *m,
3488     struct sockaddr *addr, struct mbuf *control, struct thread *td)
3489 {
3490 
3491 	return EOPNOTSUPP;
3492 }
3493 
3494 int
3495 pru_ready_notsupp(struct socket *so, struct mbuf *m, int count)
3496 {
3497 
3498 	return (EOPNOTSUPP);
3499 }
3500 
3501 /*
3502  * This isn't really a ``null'' operation, but it's the default one and
3503  * doesn't do anything destructive.
3504  */
3505 int
3506 pru_sense_null(struct socket *so, struct stat *sb)
3507 {
3508 
3509 	sb->st_blksize = so->so_snd.sb_hiwat;
3510 	return 0;
3511 }
3512 
3513 int
3514 pru_shutdown_notsupp(struct socket *so)
3515 {
3516 
3517 	return EOPNOTSUPP;
3518 }
3519 
3520 int
3521 pru_sockaddr_notsupp(struct socket *so, struct sockaddr **nam)
3522 {
3523 
3524 	return EOPNOTSUPP;
3525 }
3526 
3527 int
3528 pru_sosend_notsupp(struct socket *so, struct sockaddr *addr, struct uio *uio,
3529     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
3530 {
3531 
3532 	return EOPNOTSUPP;
3533 }
3534 
3535 int
3536 pru_soreceive_notsupp(struct socket *so, struct sockaddr **paddr,
3537     struct uio *uio, struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
3538 {
3539 
3540 	return EOPNOTSUPP;
3541 }
3542 
3543 int
3544 pru_sopoll_notsupp(struct socket *so, int events, struct ucred *cred,
3545     struct thread *td)
3546 {
3547 
3548 	return EOPNOTSUPP;
3549 }
3550 
3551 static void
3552 filt_sordetach(struct knote *kn)
3553 {
3554 	struct socket *so = kn->kn_fp->f_data;
3555 
3556 	so_rdknl_lock(so);
3557 	knlist_remove(&so->so_rdsel.si_note, kn, 1);
3558 	if (!SOLISTENING(so) && knlist_empty(&so->so_rdsel.si_note))
3559 		so->so_rcv.sb_flags &= ~SB_KNOTE;
3560 	so_rdknl_unlock(so);
3561 }
3562 
3563 /*ARGSUSED*/
3564 static int
3565 filt_soread(struct knote *kn, long hint)
3566 {
3567 	struct socket *so;
3568 
3569 	so = kn->kn_fp->f_data;
3570 
3571 	if (SOLISTENING(so)) {
3572 		SOCK_LOCK_ASSERT(so);
3573 		kn->kn_data = so->sol_qlen;
3574 		return (!TAILQ_EMPTY(&so->sol_comp));
3575 	}
3576 
3577 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
3578 
3579 	kn->kn_data = sbavail(&so->so_rcv) - so->so_rcv.sb_ctl;
3580 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
3581 		kn->kn_flags |= EV_EOF;
3582 		kn->kn_fflags = so->so_error;
3583 		return (1);
3584 	} else if (so->so_error)	/* temporary udp error */
3585 		return (1);
3586 
3587 	if (kn->kn_sfflags & NOTE_LOWAT) {
3588 		if (kn->kn_data >= kn->kn_sdata)
3589 			return (1);
3590 	} else if (sbavail(&so->so_rcv) >= so->so_rcv.sb_lowat)
3591 		return (1);
3592 
3593 	/* This hook returning non-zero indicates an event, not error */
3594 	return (hhook_run_socket(so, NULL, HHOOK_FILT_SOREAD));
3595 }
3596 
3597 static void
3598 filt_sowdetach(struct knote *kn)
3599 {
3600 	struct socket *so = kn->kn_fp->f_data;
3601 
3602 	so_wrknl_lock(so);
3603 	knlist_remove(&so->so_wrsel.si_note, kn, 1);
3604 	if (!SOLISTENING(so) && knlist_empty(&so->so_wrsel.si_note))
3605 		so->so_snd.sb_flags &= ~SB_KNOTE;
3606 	so_wrknl_unlock(so);
3607 }
3608 
3609 /*ARGSUSED*/
3610 static int
3611 filt_sowrite(struct knote *kn, long hint)
3612 {
3613 	struct socket *so;
3614 
3615 	so = kn->kn_fp->f_data;
3616 
3617 	if (SOLISTENING(so))
3618 		return (0);
3619 
3620 	SOCKBUF_LOCK_ASSERT(&so->so_snd);
3621 	kn->kn_data = sbspace(&so->so_snd);
3622 
3623 	hhook_run_socket(so, kn, HHOOK_FILT_SOWRITE);
3624 
3625 	if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
3626 		kn->kn_flags |= EV_EOF;
3627 		kn->kn_fflags = so->so_error;
3628 		return (1);
3629 	} else if (so->so_error)	/* temporary udp error */
3630 		return (1);
3631 	else if (((so->so_state & SS_ISCONNECTED) == 0) &&
3632 	    (so->so_proto->pr_flags & PR_CONNREQUIRED))
3633 		return (0);
3634 	else if (kn->kn_sfflags & NOTE_LOWAT)
3635 		return (kn->kn_data >= kn->kn_sdata);
3636 	else
3637 		return (kn->kn_data >= so->so_snd.sb_lowat);
3638 }
3639 
3640 static int
3641 filt_soempty(struct knote *kn, long hint)
3642 {
3643 	struct socket *so;
3644 
3645 	so = kn->kn_fp->f_data;
3646 
3647 	if (SOLISTENING(so))
3648 		return (1);
3649 
3650 	SOCKBUF_LOCK_ASSERT(&so->so_snd);
3651 	kn->kn_data = sbused(&so->so_snd);
3652 
3653 	if (kn->kn_data == 0)
3654 		return (1);
3655 	else
3656 		return (0);
3657 }
3658 
3659 int
3660 socheckuid(struct socket *so, uid_t uid)
3661 {
3662 
3663 	if (so == NULL)
3664 		return (EPERM);
3665 	if (so->so_cred->cr_uid != uid)
3666 		return (EPERM);
3667 	return (0);
3668 }
3669 
3670 /*
3671  * These functions are used by protocols to notify the socket layer (and its
3672  * consumers) of state changes in the sockets driven by protocol-side events.
3673  */
3674 
3675 /*
3676  * Procedures to manipulate state flags of socket and do appropriate wakeups.
3677  *
3678  * Normal sequence from the active (originating) side is that
3679  * soisconnecting() is called during processing of connect() call, resulting
3680  * in an eventual call to soisconnected() if/when the connection is
3681  * established.  When the connection is torn down soisdisconnecting() is
3682  * called during processing of disconnect() call, and soisdisconnected() is
3683  * called when the connection to the peer is totally severed.  The semantics
3684  * of these routines are such that connectionless protocols can call
3685  * soisconnected() and soisdisconnected() only, bypassing the in-progress
3686  * calls when setting up a ``connection'' takes no time.
3687  *
3688  * From the passive side, a socket is created with two queues of sockets:
3689  * so_incomp for connections in progress and so_comp for connections already
3690  * made and awaiting user acceptance.  As a protocol is preparing incoming
3691  * connections, it creates a socket structure queued on so_incomp by calling
3692  * sonewconn().  When the connection is established, soisconnected() is
3693  * called, and transfers the socket structure to so_comp, making it available
3694  * to accept().
3695  *
3696  * If a socket is closed with sockets on either so_incomp or so_comp, these
3697  * sockets are dropped.
3698  *
3699  * If higher-level protocols are implemented in the kernel, the wakeups done
3700  * here will sometimes cause software-interrupt process scheduling.
3701  */
3702 void
3703 soisconnecting(struct socket *so)
3704 {
3705 
3706 	SOCK_LOCK(so);
3707 	so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
3708 	so->so_state |= SS_ISCONNECTING;
3709 	SOCK_UNLOCK(so);
3710 }
3711 
3712 void
3713 soisconnected(struct socket *so)
3714 {
3715 	struct socket *head;
3716 	int ret;
3717 
3718 	/*
3719 	 * XXXGL: this is the only place where we acquire socket locks
3720 	 * in reverse order: first child, then listening socket.  To
3721 	 * avoid possible LOR, use try semantics.
3722 	 */
3723 restart:
3724 	SOCK_LOCK(so);
3725 	if ((head = so->so_listen) != NULL &&
3726 	    __predict_false(SOLISTEN_TRYLOCK(head) == 0)) {
3727 		SOCK_UNLOCK(so);
3728 		goto restart;
3729 	}
3730 	so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
3731 	so->so_state |= SS_ISCONNECTED;
3732 	if (head != NULL && (so->so_qstate == SQ_INCOMP)) {
3733 again:
3734 		if ((so->so_options & SO_ACCEPTFILTER) == 0) {
3735 			TAILQ_REMOVE(&head->sol_incomp, so, so_list);
3736 			head->sol_incqlen--;
3737 			TAILQ_INSERT_TAIL(&head->sol_comp, so, so_list);
3738 			head->sol_qlen++;
3739 			so->so_qstate = SQ_COMP;
3740 			SOCK_UNLOCK(so);
3741 			solisten_wakeup(head);	/* unlocks */
3742 		} else {
3743 			SOCKBUF_LOCK(&so->so_rcv);
3744 			soupcall_set(so, SO_RCV,
3745 			    head->sol_accept_filter->accf_callback,
3746 			    head->sol_accept_filter_arg);
3747 			so->so_options &= ~SO_ACCEPTFILTER;
3748 			ret = head->sol_accept_filter->accf_callback(so,
3749 			    head->sol_accept_filter_arg, M_NOWAIT);
3750 			if (ret == SU_ISCONNECTED) {
3751 				soupcall_clear(so, SO_RCV);
3752 				SOCKBUF_UNLOCK(&so->so_rcv);
3753 				goto again;
3754 			}
3755 			SOCKBUF_UNLOCK(&so->so_rcv);
3756 			SOCK_UNLOCK(so);
3757 			SOLISTEN_UNLOCK(head);
3758 		}
3759 		return;
3760 	}
3761 	if (head != NULL)
3762 		SOLISTEN_UNLOCK(head);
3763 	SOCK_UNLOCK(so);
3764 	wakeup(&so->so_timeo);
3765 	sorwakeup(so);
3766 	sowwakeup(so);
3767 }
3768 
3769 void
3770 soisdisconnecting(struct socket *so)
3771 {
3772 
3773 	SOCK_LOCK(so);
3774 	so->so_state &= ~SS_ISCONNECTING;
3775 	so->so_state |= SS_ISDISCONNECTING;
3776 
3777 	if (!SOLISTENING(so)) {
3778 		SOCKBUF_LOCK(&so->so_rcv);
3779 		socantrcvmore_locked(so);
3780 		SOCKBUF_LOCK(&so->so_snd);
3781 		socantsendmore_locked(so);
3782 	}
3783 	SOCK_UNLOCK(so);
3784 	wakeup(&so->so_timeo);
3785 }
3786 
3787 void
3788 soisdisconnected(struct socket *so)
3789 {
3790 
3791 	SOCK_LOCK(so);
3792 	so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
3793 	so->so_state |= SS_ISDISCONNECTED;
3794 
3795 	if (!SOLISTENING(so)) {
3796 		SOCKBUF_LOCK(&so->so_rcv);
3797 		socantrcvmore_locked(so);
3798 		SOCKBUF_LOCK(&so->so_snd);
3799 		sbdrop_locked(&so->so_snd, sbused(&so->so_snd));
3800 		socantsendmore_locked(so);
3801 	}
3802 	SOCK_UNLOCK(so);
3803 	wakeup(&so->so_timeo);
3804 }
3805 
3806 /*
3807  * Make a copy of a sockaddr in a malloced buffer of type M_SONAME.
3808  */
3809 struct sockaddr *
3810 sodupsockaddr(const struct sockaddr *sa, int mflags)
3811 {
3812 	struct sockaddr *sa2;
3813 
3814 	sa2 = malloc(sa->sa_len, M_SONAME, mflags);
3815 	if (sa2)
3816 		bcopy(sa, sa2, sa->sa_len);
3817 	return sa2;
3818 }
3819 
3820 /*
3821  * Register per-socket buffer upcalls.
3822  */
3823 void
3824 soupcall_set(struct socket *so, int which, so_upcall_t func, void *arg)
3825 {
3826 	struct sockbuf *sb;
3827 
3828 	KASSERT(!SOLISTENING(so), ("%s: so %p listening", __func__, so));
3829 
3830 	switch (which) {
3831 	case SO_RCV:
3832 		sb = &so->so_rcv;
3833 		break;
3834 	case SO_SND:
3835 		sb = &so->so_snd;
3836 		break;
3837 	default:
3838 		panic("soupcall_set: bad which");
3839 	}
3840 	SOCKBUF_LOCK_ASSERT(sb);
3841 	sb->sb_upcall = func;
3842 	sb->sb_upcallarg = arg;
3843 	sb->sb_flags |= SB_UPCALL;
3844 }
3845 
3846 void
3847 soupcall_clear(struct socket *so, int which)
3848 {
3849 	struct sockbuf *sb;
3850 
3851 	KASSERT(!SOLISTENING(so), ("%s: so %p listening", __func__, so));
3852 
3853 	switch (which) {
3854 	case SO_RCV:
3855 		sb = &so->so_rcv;
3856 		break;
3857 	case SO_SND:
3858 		sb = &so->so_snd;
3859 		break;
3860 	default:
3861 		panic("soupcall_clear: bad which");
3862 	}
3863 	SOCKBUF_LOCK_ASSERT(sb);
3864 	KASSERT(sb->sb_upcall != NULL,
3865 	    ("%s: so %p no upcall to clear", __func__, so));
3866 	sb->sb_upcall = NULL;
3867 	sb->sb_upcallarg = NULL;
3868 	sb->sb_flags &= ~SB_UPCALL;
3869 }
3870 
3871 void
3872 solisten_upcall_set(struct socket *so, so_upcall_t func, void *arg)
3873 {
3874 
3875 	SOLISTEN_LOCK_ASSERT(so);
3876 	so->sol_upcall = func;
3877 	so->sol_upcallarg = arg;
3878 }
3879 
3880 static void
3881 so_rdknl_lock(void *arg)
3882 {
3883 	struct socket *so = arg;
3884 
3885 	if (SOLISTENING(so))
3886 		SOCK_LOCK(so);
3887 	else
3888 		SOCKBUF_LOCK(&so->so_rcv);
3889 }
3890 
3891 static void
3892 so_rdknl_unlock(void *arg)
3893 {
3894 	struct socket *so = arg;
3895 
3896 	if (SOLISTENING(so))
3897 		SOCK_UNLOCK(so);
3898 	else
3899 		SOCKBUF_UNLOCK(&so->so_rcv);
3900 }
3901 
3902 static void
3903 so_rdknl_assert_locked(void *arg)
3904 {
3905 	struct socket *so = arg;
3906 
3907 	if (SOLISTENING(so))
3908 		SOCK_LOCK_ASSERT(so);
3909 	else
3910 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
3911 }
3912 
3913 static void
3914 so_rdknl_assert_unlocked(void *arg)
3915 {
3916 	struct socket *so = arg;
3917 
3918 	if (SOLISTENING(so))
3919 		SOCK_UNLOCK_ASSERT(so);
3920 	else
3921 		SOCKBUF_UNLOCK_ASSERT(&so->so_rcv);
3922 }
3923 
3924 static void
3925 so_wrknl_lock(void *arg)
3926 {
3927 	struct socket *so = arg;
3928 
3929 	if (SOLISTENING(so))
3930 		SOCK_LOCK(so);
3931 	else
3932 		SOCKBUF_LOCK(&so->so_snd);
3933 }
3934 
3935 static void
3936 so_wrknl_unlock(void *arg)
3937 {
3938 	struct socket *so = arg;
3939 
3940 	if (SOLISTENING(so))
3941 		SOCK_UNLOCK(so);
3942 	else
3943 		SOCKBUF_UNLOCK(&so->so_snd);
3944 }
3945 
3946 static void
3947 so_wrknl_assert_locked(void *arg)
3948 {
3949 	struct socket *so = arg;
3950 
3951 	if (SOLISTENING(so))
3952 		SOCK_LOCK_ASSERT(so);
3953 	else
3954 		SOCKBUF_LOCK_ASSERT(&so->so_snd);
3955 }
3956 
3957 static void
3958 so_wrknl_assert_unlocked(void *arg)
3959 {
3960 	struct socket *so = arg;
3961 
3962 	if (SOLISTENING(so))
3963 		SOCK_UNLOCK_ASSERT(so);
3964 	else
3965 		SOCKBUF_UNLOCK_ASSERT(&so->so_snd);
3966 }
3967 
3968 /*
3969  * Create an external-format (``xsocket'') structure using the information in
3970  * the kernel-format socket structure pointed to by so.  This is done to
3971  * reduce the spew of irrelevant information over this interface, to isolate
3972  * user code from changes in the kernel structure, and potentially to provide
3973  * information-hiding if we decide that some of this information should be
3974  * hidden from users.
3975  */
3976 void
3977 sotoxsocket(struct socket *so, struct xsocket *xso)
3978 {
3979 
3980 	xso->xso_len = sizeof *xso;
3981 	xso->xso_so = so;
3982 	xso->so_type = so->so_type;
3983 	xso->so_options = so->so_options;
3984 	xso->so_linger = so->so_linger;
3985 	xso->so_state = so->so_state;
3986 	xso->so_pcb = so->so_pcb;
3987 	xso->xso_protocol = so->so_proto->pr_protocol;
3988 	xso->xso_family = so->so_proto->pr_domain->dom_family;
3989 	xso->so_timeo = so->so_timeo;
3990 	xso->so_error = so->so_error;
3991 	xso->so_uid = so->so_cred->cr_uid;
3992 	xso->so_pgid = so->so_sigio ? so->so_sigio->sio_pgid : 0;
3993 	if (SOLISTENING(so)) {
3994 		xso->so_qlen = so->sol_qlen;
3995 		xso->so_incqlen = so->sol_incqlen;
3996 		xso->so_qlimit = so->sol_qlimit;
3997 		xso->so_oobmark = 0;
3998 		bzero(&xso->so_snd, sizeof(xso->so_snd));
3999 		bzero(&xso->so_rcv, sizeof(xso->so_rcv));
4000 	} else {
4001 		xso->so_state |= so->so_qstate;
4002 		xso->so_qlen = xso->so_incqlen = xso->so_qlimit = 0;
4003 		xso->so_oobmark = so->so_oobmark;
4004 		sbtoxsockbuf(&so->so_snd, &xso->so_snd);
4005 		sbtoxsockbuf(&so->so_rcv, &xso->so_rcv);
4006 	}
4007 }
4008 
4009 struct sockbuf *
4010 so_sockbuf_rcv(struct socket *so)
4011 {
4012 
4013 	return (&so->so_rcv);
4014 }
4015 
4016 struct sockbuf *
4017 so_sockbuf_snd(struct socket *so)
4018 {
4019 
4020 	return (&so->so_snd);
4021 }
4022 
4023 int
4024 so_state_get(const struct socket *so)
4025 {
4026 
4027 	return (so->so_state);
4028 }
4029 
4030 void
4031 so_state_set(struct socket *so, int val)
4032 {
4033 
4034 	so->so_state = val;
4035 }
4036 
4037 int
4038 so_options_get(const struct socket *so)
4039 {
4040 
4041 	return (so->so_options);
4042 }
4043 
4044 void
4045 so_options_set(struct socket *so, int val)
4046 {
4047 
4048 	so->so_options = val;
4049 }
4050 
4051 int
4052 so_error_get(const struct socket *so)
4053 {
4054 
4055 	return (so->so_error);
4056 }
4057 
4058 void
4059 so_error_set(struct socket *so, int val)
4060 {
4061 
4062 	so->so_error = val;
4063 }
4064 
4065 int
4066 so_linger_get(const struct socket *so)
4067 {
4068 
4069 	return (so->so_linger);
4070 }
4071 
4072 void
4073 so_linger_set(struct socket *so, int val)
4074 {
4075 
4076 	so->so_linger = val;
4077 }
4078 
4079 struct protosw *
4080 so_protosw_get(const struct socket *so)
4081 {
4082 
4083 	return (so->so_proto);
4084 }
4085 
4086 void
4087 so_protosw_set(struct socket *so, struct protosw *val)
4088 {
4089 
4090 	so->so_proto = val;
4091 }
4092 
4093 void
4094 so_sorwakeup(struct socket *so)
4095 {
4096 
4097 	sorwakeup(so);
4098 }
4099 
4100 void
4101 so_sowwakeup(struct socket *so)
4102 {
4103 
4104 	sowwakeup(so);
4105 }
4106 
4107 void
4108 so_sorwakeup_locked(struct socket *so)
4109 {
4110 
4111 	sorwakeup_locked(so);
4112 }
4113 
4114 void
4115 so_sowwakeup_locked(struct socket *so)
4116 {
4117 
4118 	sowwakeup_locked(so);
4119 }
4120 
4121 void
4122 so_lock(struct socket *so)
4123 {
4124 
4125 	SOCK_LOCK(so);
4126 }
4127 
4128 void
4129 so_unlock(struct socket *so)
4130 {
4131 
4132 	SOCK_UNLOCK(so);
4133 }
4134