xref: /freebsd/sys/kern/uipc_socket.c (revision 4f52dfbb)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1988, 1990, 1993
5  *	The Regents of the University of California.
6  * Copyright (c) 2004 The FreeBSD Foundation
7  * Copyright (c) 2004-2008 Robert N. M. Watson
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)uipc_socket.c	8.3 (Berkeley) 4/15/94
35  */
36 
37 /*
38  * Comments on the socket life cycle:
39  *
40  * soalloc() sets of socket layer state for a socket, called only by
41  * socreate() and sonewconn().  Socket layer private.
42  *
43  * sodealloc() tears down socket layer state for a socket, called only by
44  * sofree() and sonewconn().  Socket layer private.
45  *
46  * pru_attach() associates protocol layer state with an allocated socket;
47  * called only once, may fail, aborting socket allocation.  This is called
48  * from socreate() and sonewconn().  Socket layer private.
49  *
50  * pru_detach() disassociates protocol layer state from an attached socket,
51  * and will be called exactly once for sockets in which pru_attach() has
52  * been successfully called.  If pru_attach() returned an error,
53  * pru_detach() will not be called.  Socket layer private.
54  *
55  * pru_abort() and pru_close() notify the protocol layer that the last
56  * consumer of a socket is starting to tear down the socket, and that the
57  * protocol should terminate the connection.  Historically, pru_abort() also
58  * detached protocol state from the socket state, but this is no longer the
59  * case.
60  *
61  * socreate() creates a socket and attaches protocol state.  This is a public
62  * interface that may be used by socket layer consumers to create new
63  * sockets.
64  *
65  * sonewconn() creates a socket and attaches protocol state.  This is a
66  * public interface  that may be used by protocols to create new sockets when
67  * a new connection is received and will be available for accept() on a
68  * listen socket.
69  *
70  * soclose() destroys a socket after possibly waiting for it to disconnect.
71  * This is a public interface that socket consumers should use to close and
72  * release a socket when done with it.
73  *
74  * soabort() destroys a socket without waiting for it to disconnect (used
75  * only for incoming connections that are already partially or fully
76  * connected).  This is used internally by the socket layer when clearing
77  * listen socket queues (due to overflow or close on the listen socket), but
78  * is also a public interface protocols may use to abort connections in
79  * their incomplete listen queues should they no longer be required.  Sockets
80  * placed in completed connection listen queues should not be aborted for
81  * reasons described in the comment above the soclose() implementation.  This
82  * is not a general purpose close routine, and except in the specific
83  * circumstances described here, should not be used.
84  *
85  * sofree() will free a socket and its protocol state if all references on
86  * the socket have been released, and is the public interface to attempt to
87  * free a socket when a reference is removed.  This is a socket layer private
88  * interface.
89  *
90  * NOTE: In addition to socreate() and soclose(), which provide a single
91  * socket reference to the consumer to be managed as required, there are two
92  * calls to explicitly manage socket references, soref(), and sorele().
93  * Currently, these are generally required only when transitioning a socket
94  * from a listen queue to a file descriptor, in order to prevent garbage
95  * collection of the socket at an untimely moment.  For a number of reasons,
96  * these interfaces are not preferred, and should be avoided.
97  *
98  * NOTE: With regard to VNETs the general rule is that callers do not set
99  * curvnet. Exceptions to this rule include soabort(), sodisconnect(),
100  * sofree() (and with that sorele(), sotryfree()), as well as sonewconn()
101  * and sorflush(), which are usually called from a pre-set VNET context.
102  * sopoll() currently does not need a VNET context to be set.
103  */
104 
105 #include <sys/cdefs.h>
106 __FBSDID("$FreeBSD$");
107 
108 #include "opt_inet.h"
109 #include "opt_inet6.h"
110 #include "opt_sctp.h"
111 
112 #include <sys/param.h>
113 #include <sys/systm.h>
114 #include <sys/fcntl.h>
115 #include <sys/limits.h>
116 #include <sys/lock.h>
117 #include <sys/mac.h>
118 #include <sys/malloc.h>
119 #include <sys/mbuf.h>
120 #include <sys/mutex.h>
121 #include <sys/domain.h>
122 #include <sys/file.h>			/* for struct knote */
123 #include <sys/hhook.h>
124 #include <sys/kernel.h>
125 #include <sys/khelp.h>
126 #include <sys/event.h>
127 #include <sys/eventhandler.h>
128 #include <sys/poll.h>
129 #include <sys/proc.h>
130 #include <sys/protosw.h>
131 #include <sys/socket.h>
132 #include <sys/socketvar.h>
133 #include <sys/resourcevar.h>
134 #include <net/route.h>
135 #include <sys/signalvar.h>
136 #include <sys/stat.h>
137 #include <sys/sx.h>
138 #include <sys/sysctl.h>
139 #include <sys/taskqueue.h>
140 #include <sys/uio.h>
141 #include <sys/jail.h>
142 #include <sys/syslog.h>
143 #include <netinet/in.h>
144 
145 #include <net/vnet.h>
146 
147 #include <security/mac/mac_framework.h>
148 
149 #include <vm/uma.h>
150 
151 #ifdef COMPAT_FREEBSD32
152 #include <sys/mount.h>
153 #include <sys/sysent.h>
154 #include <compat/freebsd32/freebsd32.h>
155 #endif
156 
157 static int	soreceive_rcvoob(struct socket *so, struct uio *uio,
158 		    int flags);
159 static void	so_rdknl_lock(void *);
160 static void	so_rdknl_unlock(void *);
161 static void	so_rdknl_assert_locked(void *);
162 static void	so_rdknl_assert_unlocked(void *);
163 static void	so_wrknl_lock(void *);
164 static void	so_wrknl_unlock(void *);
165 static void	so_wrknl_assert_locked(void *);
166 static void	so_wrknl_assert_unlocked(void *);
167 
168 static void	filt_sordetach(struct knote *kn);
169 static int	filt_soread(struct knote *kn, long hint);
170 static void	filt_sowdetach(struct knote *kn);
171 static int	filt_sowrite(struct knote *kn, long hint);
172 static int	filt_soempty(struct knote *kn, long hint);
173 static int inline hhook_run_socket(struct socket *so, void *hctx, int32_t h_id);
174 fo_kqfilter_t	soo_kqfilter;
175 
176 static struct filterops soread_filtops = {
177 	.f_isfd = 1,
178 	.f_detach = filt_sordetach,
179 	.f_event = filt_soread,
180 };
181 static struct filterops sowrite_filtops = {
182 	.f_isfd = 1,
183 	.f_detach = filt_sowdetach,
184 	.f_event = filt_sowrite,
185 };
186 static struct filterops soempty_filtops = {
187 	.f_isfd = 1,
188 	.f_detach = filt_sowdetach,
189 	.f_event = filt_soempty,
190 };
191 
192 so_gen_t	so_gencnt;	/* generation count for sockets */
193 
194 MALLOC_DEFINE(M_SONAME, "soname", "socket name");
195 MALLOC_DEFINE(M_PCB, "pcb", "protocol control block");
196 
197 #define	VNET_SO_ASSERT(so)						\
198 	VNET_ASSERT(curvnet != NULL,					\
199 	    ("%s:%d curvnet is NULL, so=%p", __func__, __LINE__, (so)));
200 
201 VNET_DEFINE(struct hhook_head *, socket_hhh[HHOOK_SOCKET_LAST + 1]);
202 #define	V_socket_hhh		VNET(socket_hhh)
203 
204 /*
205  * Limit on the number of connections in the listen queue waiting
206  * for accept(2).
207  * NB: The original sysctl somaxconn is still available but hidden
208  * to prevent confusion about the actual purpose of this number.
209  */
210 static u_int somaxconn = SOMAXCONN;
211 
212 static int
213 sysctl_somaxconn(SYSCTL_HANDLER_ARGS)
214 {
215 	int error;
216 	int val;
217 
218 	val = somaxconn;
219 	error = sysctl_handle_int(oidp, &val, 0, req);
220 	if (error || !req->newptr )
221 		return (error);
222 
223 	/*
224 	 * The purpose of the UINT_MAX / 3 limit, is so that the formula
225 	 *   3 * so_qlimit / 2
226 	 * below, will not overflow.
227          */
228 
229 	if (val < 1 || val > UINT_MAX / 3)
230 		return (EINVAL);
231 
232 	somaxconn = val;
233 	return (0);
234 }
235 SYSCTL_PROC(_kern_ipc, OID_AUTO, soacceptqueue, CTLTYPE_UINT | CTLFLAG_RW,
236     0, sizeof(int), sysctl_somaxconn, "I",
237     "Maximum listen socket pending connection accept queue size");
238 SYSCTL_PROC(_kern_ipc, KIPC_SOMAXCONN, somaxconn,
239     CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_SKIP,
240     0, sizeof(int), sysctl_somaxconn, "I",
241     "Maximum listen socket pending connection accept queue size (compat)");
242 
243 static int numopensockets;
244 SYSCTL_INT(_kern_ipc, OID_AUTO, numopensockets, CTLFLAG_RD,
245     &numopensockets, 0, "Number of open sockets");
246 
247 /*
248  * accept_mtx locks down per-socket fields relating to accept queues.  See
249  * socketvar.h for an annotation of the protected fields of struct socket.
250  */
251 struct mtx accept_mtx;
252 MTX_SYSINIT(accept_mtx, &accept_mtx, "accept", MTX_DEF);
253 
254 /*
255  * so_global_mtx protects so_gencnt, numopensockets, and the per-socket
256  * so_gencnt field.
257  */
258 static struct mtx so_global_mtx;
259 MTX_SYSINIT(so_global_mtx, &so_global_mtx, "so_glabel", MTX_DEF);
260 
261 /*
262  * General IPC sysctl name space, used by sockets and a variety of other IPC
263  * types.
264  */
265 SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW, 0, "IPC");
266 
267 /*
268  * Initialize the socket subsystem and set up the socket
269  * memory allocator.
270  */
271 static uma_zone_t socket_zone;
272 int	maxsockets;
273 
274 static void
275 socket_zone_change(void *tag)
276 {
277 
278 	maxsockets = uma_zone_set_max(socket_zone, maxsockets);
279 }
280 
281 static void
282 socket_hhook_register(int subtype)
283 {
284 
285 	if (hhook_head_register(HHOOK_TYPE_SOCKET, subtype,
286 	    &V_socket_hhh[subtype],
287 	    HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
288 		printf("%s: WARNING: unable to register hook\n", __func__);
289 }
290 
291 static void
292 socket_hhook_deregister(int subtype)
293 {
294 
295 	if (hhook_head_deregister(V_socket_hhh[subtype]) != 0)
296 		printf("%s: WARNING: unable to deregister hook\n", __func__);
297 }
298 
299 static void
300 socket_init(void *tag)
301 {
302 
303 	socket_zone = uma_zcreate("socket", sizeof(struct socket), NULL, NULL,
304 	    NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
305 	maxsockets = uma_zone_set_max(socket_zone, maxsockets);
306 	uma_zone_set_warning(socket_zone, "kern.ipc.maxsockets limit reached");
307 	EVENTHANDLER_REGISTER(maxsockets_change, socket_zone_change, NULL,
308 	    EVENTHANDLER_PRI_FIRST);
309 }
310 SYSINIT(socket, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY, socket_init, NULL);
311 
312 static void
313 socket_vnet_init(const void *unused __unused)
314 {
315 	int i;
316 
317 	/* We expect a contiguous range */
318 	for (i = 0; i <= HHOOK_SOCKET_LAST; i++)
319 		socket_hhook_register(i);
320 }
321 VNET_SYSINIT(socket_vnet_init, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY,
322     socket_vnet_init, NULL);
323 
324 static void
325 socket_vnet_uninit(const void *unused __unused)
326 {
327 	int i;
328 
329 	for (i = 0; i <= HHOOK_SOCKET_LAST; i++)
330 		socket_hhook_deregister(i);
331 }
332 VNET_SYSUNINIT(socket_vnet_uninit, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY,
333     socket_vnet_uninit, NULL);
334 
335 /*
336  * Initialise maxsockets.  This SYSINIT must be run after
337  * tunable_mbinit().
338  */
339 static void
340 init_maxsockets(void *ignored)
341 {
342 
343 	TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets);
344 	maxsockets = imax(maxsockets, maxfiles);
345 }
346 SYSINIT(param, SI_SUB_TUNABLES, SI_ORDER_ANY, init_maxsockets, NULL);
347 
348 /*
349  * Sysctl to get and set the maximum global sockets limit.  Notify protocols
350  * of the change so that they can update their dependent limits as required.
351  */
352 static int
353 sysctl_maxsockets(SYSCTL_HANDLER_ARGS)
354 {
355 	int error, newmaxsockets;
356 
357 	newmaxsockets = maxsockets;
358 	error = sysctl_handle_int(oidp, &newmaxsockets, 0, req);
359 	if (error == 0 && req->newptr) {
360 		if (newmaxsockets > maxsockets &&
361 		    newmaxsockets <= maxfiles) {
362 			maxsockets = newmaxsockets;
363 			EVENTHANDLER_INVOKE(maxsockets_change);
364 		} else
365 			error = EINVAL;
366 	}
367 	return (error);
368 }
369 SYSCTL_PROC(_kern_ipc, OID_AUTO, maxsockets, CTLTYPE_INT|CTLFLAG_RW,
370     &maxsockets, 0, sysctl_maxsockets, "IU",
371     "Maximum number of sockets available");
372 
373 /*
374  * Socket operation routines.  These routines are called by the routines in
375  * sys_socket.c or from a system process, and implement the semantics of
376  * socket operations by switching out to the protocol specific routines.
377  */
378 
379 /*
380  * Get a socket structure from our zone, and initialize it.  Note that it
381  * would probably be better to allocate socket and PCB at the same time, but
382  * I'm not convinced that all the protocols can be easily modified to do
383  * this.
384  *
385  * soalloc() returns a socket with a ref count of 0.
386  */
387 static struct socket *
388 soalloc(struct vnet *vnet)
389 {
390 	struct socket *so;
391 
392 	so = uma_zalloc(socket_zone, M_NOWAIT | M_ZERO);
393 	if (so == NULL)
394 		return (NULL);
395 #ifdef MAC
396 	if (mac_socket_init(so, M_NOWAIT) != 0) {
397 		uma_zfree(socket_zone, so);
398 		return (NULL);
399 	}
400 #endif
401 	if (khelp_init_osd(HELPER_CLASS_SOCKET, &so->osd)) {
402 		uma_zfree(socket_zone, so);
403 		return (NULL);
404 	}
405 
406 	/*
407 	 * The socket locking protocol allows to lock 2 sockets at a time,
408 	 * however, the first one must be a listening socket.  WITNESS lacks
409 	 * a feature to change class of an existing lock, so we use DUPOK.
410 	 */
411 	mtx_init(&so->so_lock, "socket", NULL, MTX_DEF | MTX_DUPOK);
412 	SOCKBUF_LOCK_INIT(&so->so_snd, "so_snd");
413 	SOCKBUF_LOCK_INIT(&so->so_rcv, "so_rcv");
414 	so->so_rcv.sb_sel = &so->so_rdsel;
415 	so->so_snd.sb_sel = &so->so_wrsel;
416 	sx_init(&so->so_snd.sb_sx, "so_snd_sx");
417 	sx_init(&so->so_rcv.sb_sx, "so_rcv_sx");
418 	TAILQ_INIT(&so->so_snd.sb_aiojobq);
419 	TAILQ_INIT(&so->so_rcv.sb_aiojobq);
420 	TASK_INIT(&so->so_snd.sb_aiotask, 0, soaio_snd, so);
421 	TASK_INIT(&so->so_rcv.sb_aiotask, 0, soaio_rcv, so);
422 #ifdef VIMAGE
423 	VNET_ASSERT(vnet != NULL, ("%s:%d vnet is NULL, so=%p",
424 	    __func__, __LINE__, so));
425 	so->so_vnet = vnet;
426 #endif
427 	/* We shouldn't need the so_global_mtx */
428 	if (hhook_run_socket(so, NULL, HHOOK_SOCKET_CREATE)) {
429 		/* Do we need more comprehensive error returns? */
430 		uma_zfree(socket_zone, so);
431 		return (NULL);
432 	}
433 	mtx_lock(&so_global_mtx);
434 	so->so_gencnt = ++so_gencnt;
435 	++numopensockets;
436 #ifdef VIMAGE
437 	vnet->vnet_sockcnt++;
438 #endif
439 	mtx_unlock(&so_global_mtx);
440 
441 	return (so);
442 }
443 
444 /*
445  * Free the storage associated with a socket at the socket layer, tear down
446  * locks, labels, etc.  All protocol state is assumed already to have been
447  * torn down (and possibly never set up) by the caller.
448  */
449 static void
450 sodealloc(struct socket *so)
451 {
452 
453 	KASSERT(so->so_count == 0, ("sodealloc(): so_count %d", so->so_count));
454 	KASSERT(so->so_pcb == NULL, ("sodealloc(): so_pcb != NULL"));
455 
456 	mtx_lock(&so_global_mtx);
457 	so->so_gencnt = ++so_gencnt;
458 	--numopensockets;	/* Could be below, but faster here. */
459 #ifdef VIMAGE
460 	VNET_ASSERT(so->so_vnet != NULL, ("%s:%d so_vnet is NULL, so=%p",
461 	    __func__, __LINE__, so));
462 	so->so_vnet->vnet_sockcnt--;
463 #endif
464 	mtx_unlock(&so_global_mtx);
465 #ifdef MAC
466 	mac_socket_destroy(so);
467 #endif
468 	hhook_run_socket(so, NULL, HHOOK_SOCKET_CLOSE);
469 
470 	crfree(so->so_cred);
471 	khelp_destroy_osd(&so->osd);
472 	if (SOLISTENING(so)) {
473 		if (so->sol_accept_filter != NULL)
474 			accept_filt_setopt(so, NULL);
475 	} else {
476 		if (so->so_rcv.sb_hiwat)
477 			(void)chgsbsize(so->so_cred->cr_uidinfo,
478 			    &so->so_rcv.sb_hiwat, 0, RLIM_INFINITY);
479 		if (so->so_snd.sb_hiwat)
480 			(void)chgsbsize(so->so_cred->cr_uidinfo,
481 			    &so->so_snd.sb_hiwat, 0, RLIM_INFINITY);
482 		sx_destroy(&so->so_snd.sb_sx);
483 		sx_destroy(&so->so_rcv.sb_sx);
484 		SOCKBUF_LOCK_DESTROY(&so->so_snd);
485 		SOCKBUF_LOCK_DESTROY(&so->so_rcv);
486 	}
487 	mtx_destroy(&so->so_lock);
488 	uma_zfree(socket_zone, so);
489 }
490 
491 /*
492  * socreate returns a socket with a ref count of 1.  The socket should be
493  * closed with soclose().
494  */
495 int
496 socreate(int dom, struct socket **aso, int type, int proto,
497     struct ucred *cred, struct thread *td)
498 {
499 	struct protosw *prp;
500 	struct socket *so;
501 	int error;
502 
503 	if (proto)
504 		prp = pffindproto(dom, proto, type);
505 	else
506 		prp = pffindtype(dom, type);
507 
508 	if (prp == NULL) {
509 		/* No support for domain. */
510 		if (pffinddomain(dom) == NULL)
511 			return (EAFNOSUPPORT);
512 		/* No support for socket type. */
513 		if (proto == 0 && type != 0)
514 			return (EPROTOTYPE);
515 		return (EPROTONOSUPPORT);
516 	}
517 	if (prp->pr_usrreqs->pru_attach == NULL ||
518 	    prp->pr_usrreqs->pru_attach == pru_attach_notsupp)
519 		return (EPROTONOSUPPORT);
520 
521 	if (prison_check_af(cred, prp->pr_domain->dom_family) != 0)
522 		return (EPROTONOSUPPORT);
523 
524 	if (prp->pr_type != type)
525 		return (EPROTOTYPE);
526 	so = soalloc(CRED_TO_VNET(cred));
527 	if (so == NULL)
528 		return (ENOBUFS);
529 
530 	so->so_type = type;
531 	so->so_cred = crhold(cred);
532 	if ((prp->pr_domain->dom_family == PF_INET) ||
533 	    (prp->pr_domain->dom_family == PF_INET6) ||
534 	    (prp->pr_domain->dom_family == PF_ROUTE))
535 		so->so_fibnum = td->td_proc->p_fibnum;
536 	else
537 		so->so_fibnum = 0;
538 	so->so_proto = prp;
539 #ifdef MAC
540 	mac_socket_create(cred, so);
541 #endif
542 	knlist_init(&so->so_rdsel.si_note, so, so_rdknl_lock, so_rdknl_unlock,
543 	    so_rdknl_assert_locked, so_rdknl_assert_unlocked);
544 	knlist_init(&so->so_wrsel.si_note, so, so_wrknl_lock, so_wrknl_unlock,
545 	    so_wrknl_assert_locked, so_wrknl_assert_unlocked);
546 	/*
547 	 * Auto-sizing of socket buffers is managed by the protocols and
548 	 * the appropriate flags must be set in the pru_attach function.
549 	 */
550 	CURVNET_SET(so->so_vnet);
551 	error = (*prp->pr_usrreqs->pru_attach)(so, proto, td);
552 	CURVNET_RESTORE();
553 	if (error) {
554 		sodealloc(so);
555 		return (error);
556 	}
557 	soref(so);
558 	*aso = so;
559 	return (0);
560 }
561 
562 #ifdef REGRESSION
563 static int regression_sonewconn_earlytest = 1;
564 SYSCTL_INT(_regression, OID_AUTO, sonewconn_earlytest, CTLFLAG_RW,
565     &regression_sonewconn_earlytest, 0, "Perform early sonewconn limit test");
566 #endif
567 
568 /*
569  * When an attempt at a new connection is noted on a socket which accepts
570  * connections, sonewconn is called.  If the connection is possible (subject
571  * to space constraints, etc.) then we allocate a new structure, properly
572  * linked into the data structure of the original socket, and return this.
573  * Connstatus may be 0, or SS_ISCONFIRMING, or SS_ISCONNECTED.
574  *
575  * Note: the ref count on the socket is 0 on return.
576  */
577 struct socket *
578 sonewconn(struct socket *head, int connstatus)
579 {
580 	static struct timeval lastover;
581 	static struct timeval overinterval = { 60, 0 };
582 	static int overcount;
583 
584 	struct socket *so;
585 	u_int over;
586 
587 	SOLISTEN_LOCK(head);
588 	over = (head->sol_qlen > 3 * head->sol_qlimit / 2);
589 	SOLISTEN_UNLOCK(head);
590 #ifdef REGRESSION
591 	if (regression_sonewconn_earlytest && over) {
592 #else
593 	if (over) {
594 #endif
595 		overcount++;
596 
597 		if (ratecheck(&lastover, &overinterval)) {
598 			log(LOG_DEBUG, "%s: pcb %p: Listen queue overflow: "
599 			    "%i already in queue awaiting acceptance "
600 			    "(%d occurrences)\n",
601 			    __func__, head->so_pcb, head->sol_qlen, overcount);
602 
603 			overcount = 0;
604 		}
605 
606 		return (NULL);
607 	}
608 	VNET_ASSERT(head->so_vnet != NULL, ("%s: so %p vnet is NULL",
609 	    __func__, head));
610 	so = soalloc(head->so_vnet);
611 	if (so == NULL) {
612 		log(LOG_DEBUG, "%s: pcb %p: New socket allocation failure: "
613 		    "limit reached or out of memory\n",
614 		    __func__, head->so_pcb);
615 		return (NULL);
616 	}
617 	so->so_listen = head;
618 	so->so_type = head->so_type;
619 	so->so_linger = head->so_linger;
620 	so->so_state = head->so_state | SS_NOFDREF;
621 	so->so_fibnum = head->so_fibnum;
622 	so->so_proto = head->so_proto;
623 	so->so_cred = crhold(head->so_cred);
624 #ifdef MAC
625 	mac_socket_newconn(head, so);
626 #endif
627 	knlist_init(&so->so_rdsel.si_note, so, so_rdknl_lock, so_rdknl_unlock,
628 	    so_rdknl_assert_locked, so_rdknl_assert_unlocked);
629 	knlist_init(&so->so_wrsel.si_note, so, so_wrknl_lock, so_wrknl_unlock,
630 	    so_wrknl_assert_locked, so_wrknl_assert_unlocked);
631 	VNET_SO_ASSERT(head);
632 	if (soreserve(so, head->sol_sbsnd_hiwat, head->sol_sbrcv_hiwat)) {
633 		sodealloc(so);
634 		log(LOG_DEBUG, "%s: pcb %p: soreserve() failed\n",
635 		    __func__, head->so_pcb);
636 		return (NULL);
637 	}
638 	if ((*so->so_proto->pr_usrreqs->pru_attach)(so, 0, NULL)) {
639 		sodealloc(so);
640 		log(LOG_DEBUG, "%s: pcb %p: pru_attach() failed\n",
641 		    __func__, head->so_pcb);
642 		return (NULL);
643 	}
644 	so->so_rcv.sb_lowat = head->sol_sbrcv_lowat;
645 	so->so_snd.sb_lowat = head->sol_sbsnd_lowat;
646 	so->so_rcv.sb_timeo = head->sol_sbrcv_timeo;
647 	so->so_snd.sb_timeo = head->sol_sbsnd_timeo;
648 	so->so_rcv.sb_flags |= head->sol_sbrcv_flags & SB_AUTOSIZE;
649 	so->so_snd.sb_flags |= head->sol_sbsnd_flags & SB_AUTOSIZE;
650 
651 	SOLISTEN_LOCK(head);
652 	if (head->sol_accept_filter != NULL)
653 		connstatus = 0;
654 	so->so_state |= connstatus;
655 	so->so_options = head->so_options & ~SO_ACCEPTCONN;
656 	soref(head); /* A socket on (in)complete queue refs head. */
657 	if (connstatus) {
658 		TAILQ_INSERT_TAIL(&head->sol_comp, so, so_list);
659 		so->so_qstate = SQ_COMP;
660 		head->sol_qlen++;
661 		solisten_wakeup(head);	/* unlocks */
662 	} else {
663 		/*
664 		 * Keep removing sockets from the head until there's room for
665 		 * us to insert on the tail.  In pre-locking revisions, this
666 		 * was a simple if(), but as we could be racing with other
667 		 * threads and soabort() requires dropping locks, we must
668 		 * loop waiting for the condition to be true.
669 		 */
670 		while (head->sol_incqlen > head->sol_qlimit) {
671 			struct socket *sp;
672 
673 			sp = TAILQ_FIRST(&head->sol_incomp);
674 			TAILQ_REMOVE(&head->sol_incomp, sp, so_list);
675 			head->sol_incqlen--;
676 			SOCK_LOCK(sp);
677 			sp->so_qstate = SQ_NONE;
678 			sp->so_listen = NULL;
679 			SOCK_UNLOCK(sp);
680 			sorele(head);	/* does SOLISTEN_UNLOCK, head stays */
681 			soabort(sp);
682 			SOLISTEN_LOCK(head);
683 		}
684 		TAILQ_INSERT_TAIL(&head->sol_incomp, so, so_list);
685 		so->so_qstate = SQ_INCOMP;
686 		head->sol_incqlen++;
687 		SOLISTEN_UNLOCK(head);
688 	}
689 	return (so);
690 }
691 
692 #ifdef SCTP
693 /*
694  * Socket part of sctp_peeloff().  Detach a new socket from an
695  * association.  The new socket is returned with a reference.
696  */
697 struct socket *
698 sopeeloff(struct socket *head)
699 {
700 	struct socket *so;
701 
702 	VNET_ASSERT(head->so_vnet != NULL, ("%s:%d so_vnet is NULL, head=%p",
703 	    __func__, __LINE__, head));
704 	so = soalloc(head->so_vnet);
705 	if (so == NULL) {
706 		log(LOG_DEBUG, "%s: pcb %p: New socket allocation failure: "
707 		    "limit reached or out of memory\n",
708 		    __func__, head->so_pcb);
709 		return (NULL);
710 	}
711 	so->so_type = head->so_type;
712 	so->so_options = head->so_options;
713 	so->so_linger = head->so_linger;
714 	so->so_state = (head->so_state & SS_NBIO) | SS_ISCONNECTED;
715 	so->so_fibnum = head->so_fibnum;
716 	so->so_proto = head->so_proto;
717 	so->so_cred = crhold(head->so_cred);
718 #ifdef MAC
719 	mac_socket_newconn(head, so);
720 #endif
721 	knlist_init(&so->so_rdsel.si_note, so, so_rdknl_lock, so_rdknl_unlock,
722 	    so_rdknl_assert_locked, so_rdknl_assert_unlocked);
723 	knlist_init(&so->so_wrsel.si_note, so, so_wrknl_lock, so_wrknl_unlock,
724 	    so_wrknl_assert_locked, so_wrknl_assert_unlocked);
725 	VNET_SO_ASSERT(head);
726 	if (soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat)) {
727 		sodealloc(so);
728 		log(LOG_DEBUG, "%s: pcb %p: soreserve() failed\n",
729 		    __func__, head->so_pcb);
730 		return (NULL);
731 	}
732 	if ((*so->so_proto->pr_usrreqs->pru_attach)(so, 0, NULL)) {
733 		sodealloc(so);
734 		log(LOG_DEBUG, "%s: pcb %p: pru_attach() failed\n",
735 		    __func__, head->so_pcb);
736 		return (NULL);
737 	}
738 	so->so_rcv.sb_lowat = head->so_rcv.sb_lowat;
739 	so->so_snd.sb_lowat = head->so_snd.sb_lowat;
740 	so->so_rcv.sb_timeo = head->so_rcv.sb_timeo;
741 	so->so_snd.sb_timeo = head->so_snd.sb_timeo;
742 	so->so_rcv.sb_flags |= head->so_rcv.sb_flags & SB_AUTOSIZE;
743 	so->so_snd.sb_flags |= head->so_snd.sb_flags & SB_AUTOSIZE;
744 
745 	soref(so);
746 
747 	return (so);
748 }
749 #endif	/* SCTP */
750 
751 int
752 sobind(struct socket *so, struct sockaddr *nam, struct thread *td)
753 {
754 	int error;
755 
756 	CURVNET_SET(so->so_vnet);
757 	error = (*so->so_proto->pr_usrreqs->pru_bind)(so, nam, td);
758 	CURVNET_RESTORE();
759 	return (error);
760 }
761 
762 int
763 sobindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
764 {
765 	int error;
766 
767 	CURVNET_SET(so->so_vnet);
768 	error = (*so->so_proto->pr_usrreqs->pru_bindat)(fd, so, nam, td);
769 	CURVNET_RESTORE();
770 	return (error);
771 }
772 
773 /*
774  * solisten() transitions a socket from a non-listening state to a listening
775  * state, but can also be used to update the listen queue depth on an
776  * existing listen socket.  The protocol will call back into the sockets
777  * layer using solisten_proto_check() and solisten_proto() to check and set
778  * socket-layer listen state.  Call backs are used so that the protocol can
779  * acquire both protocol and socket layer locks in whatever order is required
780  * by the protocol.
781  *
782  * Protocol implementors are advised to hold the socket lock across the
783  * socket-layer test and set to avoid races at the socket layer.
784  */
785 int
786 solisten(struct socket *so, int backlog, struct thread *td)
787 {
788 	int error;
789 
790 	CURVNET_SET(so->so_vnet);
791 	error = (*so->so_proto->pr_usrreqs->pru_listen)(so, backlog, td);
792 	CURVNET_RESTORE();
793 	return (error);
794 }
795 
796 int
797 solisten_proto_check(struct socket *so)
798 {
799 
800 	SOCK_LOCK_ASSERT(so);
801 
802 	if (so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING |
803 	    SS_ISDISCONNECTING))
804 		return (EINVAL);
805 	return (0);
806 }
807 
808 void
809 solisten_proto(struct socket *so, int backlog)
810 {
811 	int sbrcv_lowat, sbsnd_lowat;
812 	u_int sbrcv_hiwat, sbsnd_hiwat;
813 	short sbrcv_flags, sbsnd_flags;
814 	sbintime_t sbrcv_timeo, sbsnd_timeo;
815 
816 	SOCK_LOCK_ASSERT(so);
817 
818 	if (SOLISTENING(so))
819 		goto listening;
820 
821 	/*
822 	 * Change this socket to listening state.
823 	 */
824 	sbrcv_lowat = so->so_rcv.sb_lowat;
825 	sbsnd_lowat = so->so_snd.sb_lowat;
826 	sbrcv_hiwat = so->so_rcv.sb_hiwat;
827 	sbsnd_hiwat = so->so_snd.sb_hiwat;
828 	sbrcv_flags = so->so_rcv.sb_flags;
829 	sbsnd_flags = so->so_snd.sb_flags;
830 	sbrcv_timeo = so->so_rcv.sb_timeo;
831 	sbsnd_timeo = so->so_snd.sb_timeo;
832 
833 	sbdestroy(&so->so_snd, so);
834 	sbdestroy(&so->so_rcv, so);
835 	sx_destroy(&so->so_snd.sb_sx);
836 	sx_destroy(&so->so_rcv.sb_sx);
837 	SOCKBUF_LOCK_DESTROY(&so->so_snd);
838 	SOCKBUF_LOCK_DESTROY(&so->so_rcv);
839 
840 #ifdef INVARIANTS
841 	bzero(&so->so_rcv,
842 	    sizeof(struct socket) - offsetof(struct socket, so_rcv));
843 #endif
844 
845 	so->sol_sbrcv_lowat = sbrcv_lowat;
846 	so->sol_sbsnd_lowat = sbsnd_lowat;
847 	so->sol_sbrcv_hiwat = sbrcv_hiwat;
848 	so->sol_sbsnd_hiwat = sbsnd_hiwat;
849 	so->sol_sbrcv_flags = sbrcv_flags;
850 	so->sol_sbsnd_flags = sbsnd_flags;
851 	so->sol_sbrcv_timeo = sbrcv_timeo;
852 	so->sol_sbsnd_timeo = sbsnd_timeo;
853 
854 	so->sol_qlen = so->sol_incqlen = 0;
855 	TAILQ_INIT(&so->sol_incomp);
856 	TAILQ_INIT(&so->sol_comp);
857 
858 	so->sol_accept_filter = NULL;
859 	so->sol_accept_filter_arg = NULL;
860 	so->sol_accept_filter_str = NULL;
861 
862 	so->sol_upcall = NULL;
863 	so->sol_upcallarg = NULL;
864 
865 	so->so_options |= SO_ACCEPTCONN;
866 
867 listening:
868 	if (backlog < 0 || backlog > somaxconn)
869 		backlog = somaxconn;
870 	so->sol_qlimit = backlog;
871 }
872 
873 /*
874  * Wakeup listeners/subsystems once we have a complete connection.
875  * Enters with lock, returns unlocked.
876  */
877 void
878 solisten_wakeup(struct socket *sol)
879 {
880 
881 	if (sol->sol_upcall != NULL)
882 		(void )sol->sol_upcall(sol, sol->sol_upcallarg, M_NOWAIT);
883 	else {
884 		selwakeuppri(&sol->so_rdsel, PSOCK);
885 		KNOTE_LOCKED(&sol->so_rdsel.si_note, 0);
886 	}
887 	SOLISTEN_UNLOCK(sol);
888 	wakeup_one(&sol->sol_comp);
889 }
890 
891 /*
892  * Return single connection off a listening socket queue.  Main consumer of
893  * the function is kern_accept4().  Some modules, that do their own accept
894  * management also use the function.
895  *
896  * Listening socket must be locked on entry and is returned unlocked on
897  * return.
898  * The flags argument is set of accept4(2) flags and ACCEPT4_INHERIT.
899  */
900 int
901 solisten_dequeue(struct socket *head, struct socket **ret, int flags)
902 {
903 	struct socket *so;
904 	int error;
905 
906 	SOLISTEN_LOCK_ASSERT(head);
907 
908 	while (!(head->so_state & SS_NBIO) && TAILQ_EMPTY(&head->sol_comp) &&
909 	    head->so_error == 0) {
910 		error = msleep(&head->sol_comp, &head->so_lock, PSOCK | PCATCH,
911 		    "accept", 0);
912 		if (error != 0) {
913 			SOLISTEN_UNLOCK(head);
914 			return (error);
915 		}
916 	}
917 	if (head->so_error) {
918 		error = head->so_error;
919 		head->so_error = 0;
920 		SOLISTEN_UNLOCK(head);
921 		return (error);
922         }
923 	if ((head->so_state & SS_NBIO) && TAILQ_EMPTY(&head->sol_comp)) {
924 		SOLISTEN_UNLOCK(head);
925 		return (EWOULDBLOCK);
926 	}
927 	so = TAILQ_FIRST(&head->sol_comp);
928 	SOCK_LOCK(so);
929 	KASSERT(so->so_qstate == SQ_COMP,
930 	    ("%s: so %p not SQ_COMP", __func__, so));
931 	soref(so);
932 	head->sol_qlen--;
933 	so->so_qstate = SQ_NONE;
934 	so->so_listen = NULL;
935 	TAILQ_REMOVE(&head->sol_comp, so, so_list);
936 	if (flags & ACCEPT4_INHERIT)
937 		so->so_state |= (head->so_state & SS_NBIO);
938 	else
939 		so->so_state |= (flags & SOCK_NONBLOCK) ? SS_NBIO : 0;
940 	SOCK_UNLOCK(so);
941 	sorele(head);
942 
943 	*ret = so;
944 	return (0);
945 }
946 
947 /*
948  * Evaluate the reference count and named references on a socket; if no
949  * references remain, free it.  This should be called whenever a reference is
950  * released, such as in sorele(), but also when named reference flags are
951  * cleared in socket or protocol code.
952  *
953  * sofree() will free the socket if:
954  *
955  * - There are no outstanding file descriptor references or related consumers
956  *   (so_count == 0).
957  *
958  * - The socket has been closed by user space, if ever open (SS_NOFDREF).
959  *
960  * - The protocol does not have an outstanding strong reference on the socket
961  *   (SS_PROTOREF).
962  *
963  * - The socket is not in a completed connection queue, so a process has been
964  *   notified that it is present.  If it is removed, the user process may
965  *   block in accept() despite select() saying the socket was ready.
966  */
967 void
968 sofree(struct socket *so)
969 {
970 	struct protosw *pr = so->so_proto;
971 
972 	SOCK_LOCK_ASSERT(so);
973 
974 	if ((so->so_state & SS_NOFDREF) == 0 || so->so_count != 0 ||
975 	    (so->so_state & SS_PROTOREF) || (so->so_qstate == SQ_COMP)) {
976 		SOCK_UNLOCK(so);
977 		return;
978 	}
979 
980 	if (!SOLISTENING(so) && so->so_qstate == SQ_INCOMP) {
981 		struct socket *sol;
982 
983 		sol = so->so_listen;
984 		KASSERT(sol, ("%s: so %p on incomp of NULL", __func__, so));
985 
986 		/*
987 		 * To solve race between close of a listening socket and
988 		 * a socket on its incomplete queue, we need to lock both.
989 		 * The order is first listening socket, then regular.
990 		 * Since we don't have SS_NOFDREF neither SS_PROTOREF, this
991 		 * function and the listening socket are the only pointers
992 		 * to so.  To preserve so and sol, we reference both and then
993 		 * relock.
994 		 * After relock the socket may not move to so_comp since it
995 		 * doesn't have PCB already, but it may be removed from
996 		 * so_incomp. If that happens, we share responsiblity on
997 		 * freeing the socket, but soclose() has already removed
998 		 * it from queue.
999 		 */
1000 		soref(sol);
1001 		soref(so);
1002 		SOCK_UNLOCK(so);
1003 		SOLISTEN_LOCK(sol);
1004 		SOCK_LOCK(so);
1005 		if (so->so_qstate == SQ_INCOMP) {
1006 			KASSERT(so->so_listen == sol,
1007 			    ("%s: so %p migrated out of sol %p",
1008 			    __func__, so, sol));
1009 			TAILQ_REMOVE(&sol->sol_incomp, so, so_list);
1010 			sol->sol_incqlen--;
1011 			/* This is guarenteed not to be the last. */
1012 			refcount_release(&sol->so_count);
1013 			so->so_qstate = SQ_NONE;
1014 			so->so_listen = NULL;
1015 		} else
1016 			KASSERT(so->so_listen == NULL,
1017 			    ("%s: so %p not on (in)comp with so_listen",
1018 			    __func__, so));
1019 		sorele(sol);
1020 		KASSERT(so->so_count == 1,
1021 		    ("%s: so %p count %u", __func__, so, so->so_count));
1022 		so->so_count = 0;
1023 	}
1024 	if (SOLISTENING(so))
1025 		so->so_error = ECONNABORTED;
1026 	SOCK_UNLOCK(so);
1027 
1028 	VNET_SO_ASSERT(so);
1029 	if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose != NULL)
1030 		(*pr->pr_domain->dom_dispose)(so);
1031 	if (pr->pr_usrreqs->pru_detach != NULL)
1032 		(*pr->pr_usrreqs->pru_detach)(so);
1033 
1034 	/*
1035 	 * From this point on, we assume that no other references to this
1036 	 * socket exist anywhere else in the stack.  Therefore, no locks need
1037 	 * to be acquired or held.
1038 	 *
1039 	 * We used to do a lot of socket buffer and socket locking here, as
1040 	 * well as invoke sorflush() and perform wakeups.  The direct call to
1041 	 * dom_dispose() and sbrelease_internal() are an inlining of what was
1042 	 * necessary from sorflush().
1043 	 *
1044 	 * Notice that the socket buffer and kqueue state are torn down
1045 	 * before calling pru_detach.  This means that protocols shold not
1046 	 * assume they can perform socket wakeups, etc, in their detach code.
1047 	 */
1048 	if (!SOLISTENING(so)) {
1049 		sbdestroy(&so->so_snd, so);
1050 		sbdestroy(&so->so_rcv, so);
1051 	}
1052 	seldrain(&so->so_rdsel);
1053 	seldrain(&so->so_wrsel);
1054 	knlist_destroy(&so->so_rdsel.si_note);
1055 	knlist_destroy(&so->so_wrsel.si_note);
1056 	sodealloc(so);
1057 }
1058 
1059 /*
1060  * Close a socket on last file table reference removal.  Initiate disconnect
1061  * if connected.  Free socket when disconnect complete.
1062  *
1063  * This function will sorele() the socket.  Note that soclose() may be called
1064  * prior to the ref count reaching zero.  The actual socket structure will
1065  * not be freed until the ref count reaches zero.
1066  */
1067 int
1068 soclose(struct socket *so)
1069 {
1070 	struct accept_queue lqueue;
1071 	bool listening;
1072 	int error = 0;
1073 
1074 	KASSERT(!(so->so_state & SS_NOFDREF), ("soclose: SS_NOFDREF on enter"));
1075 
1076 	CURVNET_SET(so->so_vnet);
1077 	funsetown(&so->so_sigio);
1078 	if (so->so_state & SS_ISCONNECTED) {
1079 		if ((so->so_state & SS_ISDISCONNECTING) == 0) {
1080 			error = sodisconnect(so);
1081 			if (error) {
1082 				if (error == ENOTCONN)
1083 					error = 0;
1084 				goto drop;
1085 			}
1086 		}
1087 		if (so->so_options & SO_LINGER) {
1088 			if ((so->so_state & SS_ISDISCONNECTING) &&
1089 			    (so->so_state & SS_NBIO))
1090 				goto drop;
1091 			while (so->so_state & SS_ISCONNECTED) {
1092 				error = tsleep(&so->so_timeo,
1093 				    PSOCK | PCATCH, "soclos",
1094 				    so->so_linger * hz);
1095 				if (error)
1096 					break;
1097 			}
1098 		}
1099 	}
1100 
1101 drop:
1102 	if (so->so_proto->pr_usrreqs->pru_close != NULL)
1103 		(*so->so_proto->pr_usrreqs->pru_close)(so);
1104 
1105 	SOCK_LOCK(so);
1106 	if ((listening = (so->so_options & SO_ACCEPTCONN))) {
1107 		struct socket *sp;
1108 
1109 		TAILQ_INIT(&lqueue);
1110 		TAILQ_SWAP(&lqueue, &so->sol_incomp, socket, so_list);
1111 		TAILQ_CONCAT(&lqueue, &so->sol_comp, so_list);
1112 
1113 		so->sol_qlen = so->sol_incqlen = 0;
1114 
1115 		TAILQ_FOREACH(sp, &lqueue, so_list) {
1116 			SOCK_LOCK(sp);
1117 			sp->so_qstate = SQ_NONE;
1118 			sp->so_listen = NULL;
1119 			SOCK_UNLOCK(sp);
1120 			/* Guaranteed not to be the last. */
1121 			refcount_release(&so->so_count);
1122 		}
1123 	}
1124 	KASSERT((so->so_state & SS_NOFDREF) == 0, ("soclose: NOFDREF"));
1125 	so->so_state |= SS_NOFDREF;
1126 	sorele(so);
1127 	if (listening) {
1128 		struct socket *sp;
1129 
1130 		TAILQ_FOREACH(sp, &lqueue, so_list) {
1131 			SOCK_LOCK(sp);
1132 			if (sp->so_count == 0) {
1133 				SOCK_UNLOCK(sp);
1134 				soabort(sp);
1135 			} else
1136 				/* sp is now in sofree() */
1137 				SOCK_UNLOCK(sp);
1138 		}
1139 	}
1140 	CURVNET_RESTORE();
1141 	return (error);
1142 }
1143 
1144 /*
1145  * soabort() is used to abruptly tear down a connection, such as when a
1146  * resource limit is reached (listen queue depth exceeded), or if a listen
1147  * socket is closed while there are sockets waiting to be accepted.
1148  *
1149  * This interface is tricky, because it is called on an unreferenced socket,
1150  * and must be called only by a thread that has actually removed the socket
1151  * from the listen queue it was on, or races with other threads are risked.
1152  *
1153  * This interface will call into the protocol code, so must not be called
1154  * with any socket locks held.  Protocols do call it while holding their own
1155  * recursible protocol mutexes, but this is something that should be subject
1156  * to review in the future.
1157  */
1158 void
1159 soabort(struct socket *so)
1160 {
1161 
1162 	/*
1163 	 * In as much as is possible, assert that no references to this
1164 	 * socket are held.  This is not quite the same as asserting that the
1165 	 * current thread is responsible for arranging for no references, but
1166 	 * is as close as we can get for now.
1167 	 */
1168 	KASSERT(so->so_count == 0, ("soabort: so_count"));
1169 	KASSERT((so->so_state & SS_PROTOREF) == 0, ("soabort: SS_PROTOREF"));
1170 	KASSERT(so->so_state & SS_NOFDREF, ("soabort: !SS_NOFDREF"));
1171 	KASSERT(so->so_qstate == SQ_NONE, ("soabort: !SQ_NONE"));
1172 	VNET_SO_ASSERT(so);
1173 
1174 	if (so->so_proto->pr_usrreqs->pru_abort != NULL)
1175 		(*so->so_proto->pr_usrreqs->pru_abort)(so);
1176 	SOCK_LOCK(so);
1177 	sofree(so);
1178 }
1179 
1180 int
1181 soaccept(struct socket *so, struct sockaddr **nam)
1182 {
1183 	int error;
1184 
1185 	SOCK_LOCK(so);
1186 	KASSERT((so->so_state & SS_NOFDREF) != 0, ("soaccept: !NOFDREF"));
1187 	so->so_state &= ~SS_NOFDREF;
1188 	SOCK_UNLOCK(so);
1189 
1190 	CURVNET_SET(so->so_vnet);
1191 	error = (*so->so_proto->pr_usrreqs->pru_accept)(so, nam);
1192 	CURVNET_RESTORE();
1193 	return (error);
1194 }
1195 
1196 int
1197 soconnect(struct socket *so, struct sockaddr *nam, struct thread *td)
1198 {
1199 
1200 	return (soconnectat(AT_FDCWD, so, nam, td));
1201 }
1202 
1203 int
1204 soconnectat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
1205 {
1206 	int error;
1207 
1208 	if (so->so_options & SO_ACCEPTCONN)
1209 		return (EOPNOTSUPP);
1210 
1211 	CURVNET_SET(so->so_vnet);
1212 	/*
1213 	 * If protocol is connection-based, can only connect once.
1214 	 * Otherwise, if connected, try to disconnect first.  This allows
1215 	 * user to disconnect by connecting to, e.g., a null address.
1216 	 */
1217 	if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
1218 	    ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
1219 	    (error = sodisconnect(so)))) {
1220 		error = EISCONN;
1221 	} else {
1222 		/*
1223 		 * Prevent accumulated error from previous connection from
1224 		 * biting us.
1225 		 */
1226 		so->so_error = 0;
1227 		if (fd == AT_FDCWD) {
1228 			error = (*so->so_proto->pr_usrreqs->pru_connect)(so,
1229 			    nam, td);
1230 		} else {
1231 			error = (*so->so_proto->pr_usrreqs->pru_connectat)(fd,
1232 			    so, nam, td);
1233 		}
1234 	}
1235 	CURVNET_RESTORE();
1236 
1237 	return (error);
1238 }
1239 
1240 int
1241 soconnect2(struct socket *so1, struct socket *so2)
1242 {
1243 	int error;
1244 
1245 	CURVNET_SET(so1->so_vnet);
1246 	error = (*so1->so_proto->pr_usrreqs->pru_connect2)(so1, so2);
1247 	CURVNET_RESTORE();
1248 	return (error);
1249 }
1250 
1251 int
1252 sodisconnect(struct socket *so)
1253 {
1254 	int error;
1255 
1256 	if ((so->so_state & SS_ISCONNECTED) == 0)
1257 		return (ENOTCONN);
1258 	if (so->so_state & SS_ISDISCONNECTING)
1259 		return (EALREADY);
1260 	VNET_SO_ASSERT(so);
1261 	error = (*so->so_proto->pr_usrreqs->pru_disconnect)(so);
1262 	return (error);
1263 }
1264 
1265 #define	SBLOCKWAIT(f)	(((f) & MSG_DONTWAIT) ? 0 : SBL_WAIT)
1266 
1267 int
1268 sosend_dgram(struct socket *so, struct sockaddr *addr, struct uio *uio,
1269     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
1270 {
1271 	long space;
1272 	ssize_t resid;
1273 	int clen = 0, error, dontroute;
1274 
1275 	KASSERT(so->so_type == SOCK_DGRAM, ("sosend_dgram: !SOCK_DGRAM"));
1276 	KASSERT(so->so_proto->pr_flags & PR_ATOMIC,
1277 	    ("sosend_dgram: !PR_ATOMIC"));
1278 
1279 	if (uio != NULL)
1280 		resid = uio->uio_resid;
1281 	else
1282 		resid = top->m_pkthdr.len;
1283 	/*
1284 	 * In theory resid should be unsigned.  However, space must be
1285 	 * signed, as it might be less than 0 if we over-committed, and we
1286 	 * must use a signed comparison of space and resid.  On the other
1287 	 * hand, a negative resid causes us to loop sending 0-length
1288 	 * segments to the protocol.
1289 	 */
1290 	if (resid < 0) {
1291 		error = EINVAL;
1292 		goto out;
1293 	}
1294 
1295 	dontroute =
1296 	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0;
1297 	if (td != NULL)
1298 		td->td_ru.ru_msgsnd++;
1299 	if (control != NULL)
1300 		clen = control->m_len;
1301 
1302 	SOCKBUF_LOCK(&so->so_snd);
1303 	if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
1304 		SOCKBUF_UNLOCK(&so->so_snd);
1305 		error = EPIPE;
1306 		goto out;
1307 	}
1308 	if (so->so_error) {
1309 		error = so->so_error;
1310 		so->so_error = 0;
1311 		SOCKBUF_UNLOCK(&so->so_snd);
1312 		goto out;
1313 	}
1314 	if ((so->so_state & SS_ISCONNECTED) == 0) {
1315 		/*
1316 		 * `sendto' and `sendmsg' is allowed on a connection-based
1317 		 * socket if it supports implied connect.  Return ENOTCONN if
1318 		 * not connected and no address is supplied.
1319 		 */
1320 		if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
1321 		    (so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
1322 			if ((so->so_state & SS_ISCONFIRMING) == 0 &&
1323 			    !(resid == 0 && clen != 0)) {
1324 				SOCKBUF_UNLOCK(&so->so_snd);
1325 				error = ENOTCONN;
1326 				goto out;
1327 			}
1328 		} else if (addr == NULL) {
1329 			if (so->so_proto->pr_flags & PR_CONNREQUIRED)
1330 				error = ENOTCONN;
1331 			else
1332 				error = EDESTADDRREQ;
1333 			SOCKBUF_UNLOCK(&so->so_snd);
1334 			goto out;
1335 		}
1336 	}
1337 
1338 	/*
1339 	 * Do we need MSG_OOB support in SOCK_DGRAM?  Signs here may be a
1340 	 * problem and need fixing.
1341 	 */
1342 	space = sbspace(&so->so_snd);
1343 	if (flags & MSG_OOB)
1344 		space += 1024;
1345 	space -= clen;
1346 	SOCKBUF_UNLOCK(&so->so_snd);
1347 	if (resid > space) {
1348 		error = EMSGSIZE;
1349 		goto out;
1350 	}
1351 	if (uio == NULL) {
1352 		resid = 0;
1353 		if (flags & MSG_EOR)
1354 			top->m_flags |= M_EOR;
1355 	} else {
1356 		/*
1357 		 * Copy the data from userland into a mbuf chain.
1358 		 * If no data is to be copied in, a single empty mbuf
1359 		 * is returned.
1360 		 */
1361 		top = m_uiotombuf(uio, M_WAITOK, space, max_hdr,
1362 		    (M_PKTHDR | ((flags & MSG_EOR) ? M_EOR : 0)));
1363 		if (top == NULL) {
1364 			error = EFAULT;	/* only possible error */
1365 			goto out;
1366 		}
1367 		space -= resid - uio->uio_resid;
1368 		resid = uio->uio_resid;
1369 	}
1370 	KASSERT(resid == 0, ("sosend_dgram: resid != 0"));
1371 	/*
1372 	 * XXXRW: Frobbing SO_DONTROUTE here is even worse without sblock
1373 	 * than with.
1374 	 */
1375 	if (dontroute) {
1376 		SOCK_LOCK(so);
1377 		so->so_options |= SO_DONTROUTE;
1378 		SOCK_UNLOCK(so);
1379 	}
1380 	/*
1381 	 * XXX all the SBS_CANTSENDMORE checks previously done could be out
1382 	 * of date.  We could have received a reset packet in an interrupt or
1383 	 * maybe we slept while doing page faults in uiomove() etc.  We could
1384 	 * probably recheck again inside the locking protection here, but
1385 	 * there are probably other places that this also happens.  We must
1386 	 * rethink this.
1387 	 */
1388 	VNET_SO_ASSERT(so);
1389 	error = (*so->so_proto->pr_usrreqs->pru_send)(so,
1390 	    (flags & MSG_OOB) ? PRUS_OOB :
1391 	/*
1392 	 * If the user set MSG_EOF, the protocol understands this flag and
1393 	 * nothing left to send then use PRU_SEND_EOF instead of PRU_SEND.
1394 	 */
1395 	    ((flags & MSG_EOF) &&
1396 	     (so->so_proto->pr_flags & PR_IMPLOPCL) &&
1397 	     (resid <= 0)) ?
1398 		PRUS_EOF :
1399 		/* If there is more to send set PRUS_MORETOCOME */
1400 		(flags & MSG_MORETOCOME) ||
1401 		(resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
1402 		top, addr, control, td);
1403 	if (dontroute) {
1404 		SOCK_LOCK(so);
1405 		so->so_options &= ~SO_DONTROUTE;
1406 		SOCK_UNLOCK(so);
1407 	}
1408 	clen = 0;
1409 	control = NULL;
1410 	top = NULL;
1411 out:
1412 	if (top != NULL)
1413 		m_freem(top);
1414 	if (control != NULL)
1415 		m_freem(control);
1416 	return (error);
1417 }
1418 
1419 /*
1420  * Send on a socket.  If send must go all at once and message is larger than
1421  * send buffering, then hard error.  Lock against other senders.  If must go
1422  * all at once and not enough room now, then inform user that this would
1423  * block and do nothing.  Otherwise, if nonblocking, send as much as
1424  * possible.  The data to be sent is described by "uio" if nonzero, otherwise
1425  * by the mbuf chain "top" (which must be null if uio is not).  Data provided
1426  * in mbuf chain must be small enough to send all at once.
1427  *
1428  * Returns nonzero on error, timeout or signal; callers must check for short
1429  * counts if EINTR/ERESTART are returned.  Data and control buffers are freed
1430  * on return.
1431  */
1432 int
1433 sosend_generic(struct socket *so, struct sockaddr *addr, struct uio *uio,
1434     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
1435 {
1436 	long space;
1437 	ssize_t resid;
1438 	int clen = 0, error, dontroute;
1439 	int atomic = sosendallatonce(so) || top;
1440 
1441 	if (uio != NULL)
1442 		resid = uio->uio_resid;
1443 	else
1444 		resid = top->m_pkthdr.len;
1445 	/*
1446 	 * In theory resid should be unsigned.  However, space must be
1447 	 * signed, as it might be less than 0 if we over-committed, and we
1448 	 * must use a signed comparison of space and resid.  On the other
1449 	 * hand, a negative resid causes us to loop sending 0-length
1450 	 * segments to the protocol.
1451 	 *
1452 	 * Also check to make sure that MSG_EOR isn't used on SOCK_STREAM
1453 	 * type sockets since that's an error.
1454 	 */
1455 	if (resid < 0 || (so->so_type == SOCK_STREAM && (flags & MSG_EOR))) {
1456 		error = EINVAL;
1457 		goto out;
1458 	}
1459 
1460 	dontroute =
1461 	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
1462 	    (so->so_proto->pr_flags & PR_ATOMIC);
1463 	if (td != NULL)
1464 		td->td_ru.ru_msgsnd++;
1465 	if (control != NULL)
1466 		clen = control->m_len;
1467 
1468 	error = sblock(&so->so_snd, SBLOCKWAIT(flags));
1469 	if (error)
1470 		goto out;
1471 
1472 restart:
1473 	do {
1474 		SOCKBUF_LOCK(&so->so_snd);
1475 		if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
1476 			SOCKBUF_UNLOCK(&so->so_snd);
1477 			error = EPIPE;
1478 			goto release;
1479 		}
1480 		if (so->so_error) {
1481 			error = so->so_error;
1482 			so->so_error = 0;
1483 			SOCKBUF_UNLOCK(&so->so_snd);
1484 			goto release;
1485 		}
1486 		if ((so->so_state & SS_ISCONNECTED) == 0) {
1487 			/*
1488 			 * `sendto' and `sendmsg' is allowed on a connection-
1489 			 * based socket if it supports implied connect.
1490 			 * Return ENOTCONN if not connected and no address is
1491 			 * supplied.
1492 			 */
1493 			if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
1494 			    (so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
1495 				if ((so->so_state & SS_ISCONFIRMING) == 0 &&
1496 				    !(resid == 0 && clen != 0)) {
1497 					SOCKBUF_UNLOCK(&so->so_snd);
1498 					error = ENOTCONN;
1499 					goto release;
1500 				}
1501 			} else if (addr == NULL) {
1502 				SOCKBUF_UNLOCK(&so->so_snd);
1503 				if (so->so_proto->pr_flags & PR_CONNREQUIRED)
1504 					error = ENOTCONN;
1505 				else
1506 					error = EDESTADDRREQ;
1507 				goto release;
1508 			}
1509 		}
1510 		space = sbspace(&so->so_snd);
1511 		if (flags & MSG_OOB)
1512 			space += 1024;
1513 		if ((atomic && resid > so->so_snd.sb_hiwat) ||
1514 		    clen > so->so_snd.sb_hiwat) {
1515 			SOCKBUF_UNLOCK(&so->so_snd);
1516 			error = EMSGSIZE;
1517 			goto release;
1518 		}
1519 		if (space < resid + clen &&
1520 		    (atomic || space < so->so_snd.sb_lowat || space < clen)) {
1521 			if ((so->so_state & SS_NBIO) || (flags & MSG_NBIO)) {
1522 				SOCKBUF_UNLOCK(&so->so_snd);
1523 				error = EWOULDBLOCK;
1524 				goto release;
1525 			}
1526 			error = sbwait(&so->so_snd);
1527 			SOCKBUF_UNLOCK(&so->so_snd);
1528 			if (error)
1529 				goto release;
1530 			goto restart;
1531 		}
1532 		SOCKBUF_UNLOCK(&so->so_snd);
1533 		space -= clen;
1534 		do {
1535 			if (uio == NULL) {
1536 				resid = 0;
1537 				if (flags & MSG_EOR)
1538 					top->m_flags |= M_EOR;
1539 			} else {
1540 				/*
1541 				 * Copy the data from userland into a mbuf
1542 				 * chain.  If resid is 0, which can happen
1543 				 * only if we have control to send, then
1544 				 * a single empty mbuf is returned.  This
1545 				 * is a workaround to prevent protocol send
1546 				 * methods to panic.
1547 				 */
1548 				top = m_uiotombuf(uio, M_WAITOK, space,
1549 				    (atomic ? max_hdr : 0),
1550 				    (atomic ? M_PKTHDR : 0) |
1551 				    ((flags & MSG_EOR) ? M_EOR : 0));
1552 				if (top == NULL) {
1553 					error = EFAULT; /* only possible error */
1554 					goto release;
1555 				}
1556 				space -= resid - uio->uio_resid;
1557 				resid = uio->uio_resid;
1558 			}
1559 			if (dontroute) {
1560 				SOCK_LOCK(so);
1561 				so->so_options |= SO_DONTROUTE;
1562 				SOCK_UNLOCK(so);
1563 			}
1564 			/*
1565 			 * XXX all the SBS_CANTSENDMORE checks previously
1566 			 * done could be out of date.  We could have received
1567 			 * a reset packet in an interrupt or maybe we slept
1568 			 * while doing page faults in uiomove() etc.  We
1569 			 * could probably recheck again inside the locking
1570 			 * protection here, but there are probably other
1571 			 * places that this also happens.  We must rethink
1572 			 * this.
1573 			 */
1574 			VNET_SO_ASSERT(so);
1575 			error = (*so->so_proto->pr_usrreqs->pru_send)(so,
1576 			    (flags & MSG_OOB) ? PRUS_OOB :
1577 			/*
1578 			 * If the user set MSG_EOF, the protocol understands
1579 			 * this flag and nothing left to send then use
1580 			 * PRU_SEND_EOF instead of PRU_SEND.
1581 			 */
1582 			    ((flags & MSG_EOF) &&
1583 			     (so->so_proto->pr_flags & PR_IMPLOPCL) &&
1584 			     (resid <= 0)) ?
1585 				PRUS_EOF :
1586 			/* If there is more to send set PRUS_MORETOCOME. */
1587 			    (flags & MSG_MORETOCOME) ||
1588 			    (resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
1589 			    top, addr, control, td);
1590 			if (dontroute) {
1591 				SOCK_LOCK(so);
1592 				so->so_options &= ~SO_DONTROUTE;
1593 				SOCK_UNLOCK(so);
1594 			}
1595 			clen = 0;
1596 			control = NULL;
1597 			top = NULL;
1598 			if (error)
1599 				goto release;
1600 		} while (resid && space > 0);
1601 	} while (resid);
1602 
1603 release:
1604 	sbunlock(&so->so_snd);
1605 out:
1606 	if (top != NULL)
1607 		m_freem(top);
1608 	if (control != NULL)
1609 		m_freem(control);
1610 	return (error);
1611 }
1612 
1613 int
1614 sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
1615     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
1616 {
1617 	int error;
1618 
1619 	CURVNET_SET(so->so_vnet);
1620 	if (!SOLISTENING(so))
1621 		error = so->so_proto->pr_usrreqs->pru_sosend(so, addr, uio,
1622 		    top, control, flags, td);
1623 	else {
1624 		m_freem(top);
1625 		m_freem(control);
1626 		error = ENOTCONN;
1627 	}
1628 	CURVNET_RESTORE();
1629 	return (error);
1630 }
1631 
1632 /*
1633  * The part of soreceive() that implements reading non-inline out-of-band
1634  * data from a socket.  For more complete comments, see soreceive(), from
1635  * which this code originated.
1636  *
1637  * Note that soreceive_rcvoob(), unlike the remainder of soreceive(), is
1638  * unable to return an mbuf chain to the caller.
1639  */
1640 static int
1641 soreceive_rcvoob(struct socket *so, struct uio *uio, int flags)
1642 {
1643 	struct protosw *pr = so->so_proto;
1644 	struct mbuf *m;
1645 	int error;
1646 
1647 	KASSERT(flags & MSG_OOB, ("soreceive_rcvoob: (flags & MSG_OOB) == 0"));
1648 	VNET_SO_ASSERT(so);
1649 
1650 	m = m_get(M_WAITOK, MT_DATA);
1651 	error = (*pr->pr_usrreqs->pru_rcvoob)(so, m, flags & MSG_PEEK);
1652 	if (error)
1653 		goto bad;
1654 	do {
1655 		error = uiomove(mtod(m, void *),
1656 		    (int) min(uio->uio_resid, m->m_len), uio);
1657 		m = m_free(m);
1658 	} while (uio->uio_resid && error == 0 && m);
1659 bad:
1660 	if (m != NULL)
1661 		m_freem(m);
1662 	return (error);
1663 }
1664 
1665 /*
1666  * Following replacement or removal of the first mbuf on the first mbuf chain
1667  * of a socket buffer, push necessary state changes back into the socket
1668  * buffer so that other consumers see the values consistently.  'nextrecord'
1669  * is the callers locally stored value of the original value of
1670  * sb->sb_mb->m_nextpkt which must be restored when the lead mbuf changes.
1671  * NOTE: 'nextrecord' may be NULL.
1672  */
1673 static __inline void
1674 sockbuf_pushsync(struct sockbuf *sb, struct mbuf *nextrecord)
1675 {
1676 
1677 	SOCKBUF_LOCK_ASSERT(sb);
1678 	/*
1679 	 * First, update for the new value of nextrecord.  If necessary, make
1680 	 * it the first record.
1681 	 */
1682 	if (sb->sb_mb != NULL)
1683 		sb->sb_mb->m_nextpkt = nextrecord;
1684 	else
1685 		sb->sb_mb = nextrecord;
1686 
1687 	/*
1688 	 * Now update any dependent socket buffer fields to reflect the new
1689 	 * state.  This is an expanded inline of SB_EMPTY_FIXUP(), with the
1690 	 * addition of a second clause that takes care of the case where
1691 	 * sb_mb has been updated, but remains the last record.
1692 	 */
1693 	if (sb->sb_mb == NULL) {
1694 		sb->sb_mbtail = NULL;
1695 		sb->sb_lastrecord = NULL;
1696 	} else if (sb->sb_mb->m_nextpkt == NULL)
1697 		sb->sb_lastrecord = sb->sb_mb;
1698 }
1699 
1700 /*
1701  * Implement receive operations on a socket.  We depend on the way that
1702  * records are added to the sockbuf by sbappend.  In particular, each record
1703  * (mbufs linked through m_next) must begin with an address if the protocol
1704  * so specifies, followed by an optional mbuf or mbufs containing ancillary
1705  * data, and then zero or more mbufs of data.  In order to allow parallelism
1706  * between network receive and copying to user space, as well as avoid
1707  * sleeping with a mutex held, we release the socket buffer mutex during the
1708  * user space copy.  Although the sockbuf is locked, new data may still be
1709  * appended, and thus we must maintain consistency of the sockbuf during that
1710  * time.
1711  *
1712  * The caller may receive the data as a single mbuf chain by supplying an
1713  * mbuf **mp0 for use in returning the chain.  The uio is then used only for
1714  * the count in uio_resid.
1715  */
1716 int
1717 soreceive_generic(struct socket *so, struct sockaddr **psa, struct uio *uio,
1718     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
1719 {
1720 	struct mbuf *m, **mp;
1721 	int flags, error, offset;
1722 	ssize_t len;
1723 	struct protosw *pr = so->so_proto;
1724 	struct mbuf *nextrecord;
1725 	int moff, type = 0;
1726 	ssize_t orig_resid = uio->uio_resid;
1727 
1728 	mp = mp0;
1729 	if (psa != NULL)
1730 		*psa = NULL;
1731 	if (controlp != NULL)
1732 		*controlp = NULL;
1733 	if (flagsp != NULL)
1734 		flags = *flagsp &~ MSG_EOR;
1735 	else
1736 		flags = 0;
1737 	if (flags & MSG_OOB)
1738 		return (soreceive_rcvoob(so, uio, flags));
1739 	if (mp != NULL)
1740 		*mp = NULL;
1741 	if ((pr->pr_flags & PR_WANTRCVD) && (so->so_state & SS_ISCONFIRMING)
1742 	    && uio->uio_resid) {
1743 		VNET_SO_ASSERT(so);
1744 		(*pr->pr_usrreqs->pru_rcvd)(so, 0);
1745 	}
1746 
1747 	error = sblock(&so->so_rcv, SBLOCKWAIT(flags));
1748 	if (error)
1749 		return (error);
1750 
1751 restart:
1752 	SOCKBUF_LOCK(&so->so_rcv);
1753 	m = so->so_rcv.sb_mb;
1754 	/*
1755 	 * If we have less data than requested, block awaiting more (subject
1756 	 * to any timeout) if:
1757 	 *   1. the current count is less than the low water mark, or
1758 	 *   2. MSG_DONTWAIT is not set
1759 	 */
1760 	if (m == NULL || (((flags & MSG_DONTWAIT) == 0 &&
1761 	    sbavail(&so->so_rcv) < uio->uio_resid) &&
1762 	    sbavail(&so->so_rcv) < so->so_rcv.sb_lowat &&
1763 	    m->m_nextpkt == NULL && (pr->pr_flags & PR_ATOMIC) == 0)) {
1764 		KASSERT(m != NULL || !sbavail(&so->so_rcv),
1765 		    ("receive: m == %p sbavail == %u",
1766 		    m, sbavail(&so->so_rcv)));
1767 		if (so->so_error) {
1768 			if (m != NULL)
1769 				goto dontblock;
1770 			error = so->so_error;
1771 			if ((flags & MSG_PEEK) == 0)
1772 				so->so_error = 0;
1773 			SOCKBUF_UNLOCK(&so->so_rcv);
1774 			goto release;
1775 		}
1776 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1777 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
1778 			if (m == NULL) {
1779 				SOCKBUF_UNLOCK(&so->so_rcv);
1780 				goto release;
1781 			} else
1782 				goto dontblock;
1783 		}
1784 		for (; m != NULL; m = m->m_next)
1785 			if (m->m_type == MT_OOBDATA  || (m->m_flags & M_EOR)) {
1786 				m = so->so_rcv.sb_mb;
1787 				goto dontblock;
1788 			}
1789 		if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
1790 		    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
1791 			SOCKBUF_UNLOCK(&so->so_rcv);
1792 			error = ENOTCONN;
1793 			goto release;
1794 		}
1795 		if (uio->uio_resid == 0) {
1796 			SOCKBUF_UNLOCK(&so->so_rcv);
1797 			goto release;
1798 		}
1799 		if ((so->so_state & SS_NBIO) ||
1800 		    (flags & (MSG_DONTWAIT|MSG_NBIO))) {
1801 			SOCKBUF_UNLOCK(&so->so_rcv);
1802 			error = EWOULDBLOCK;
1803 			goto release;
1804 		}
1805 		SBLASTRECORDCHK(&so->so_rcv);
1806 		SBLASTMBUFCHK(&so->so_rcv);
1807 		error = sbwait(&so->so_rcv);
1808 		SOCKBUF_UNLOCK(&so->so_rcv);
1809 		if (error)
1810 			goto release;
1811 		goto restart;
1812 	}
1813 dontblock:
1814 	/*
1815 	 * From this point onward, we maintain 'nextrecord' as a cache of the
1816 	 * pointer to the next record in the socket buffer.  We must keep the
1817 	 * various socket buffer pointers and local stack versions of the
1818 	 * pointers in sync, pushing out modifications before dropping the
1819 	 * socket buffer mutex, and re-reading them when picking it up.
1820 	 *
1821 	 * Otherwise, we will race with the network stack appending new data
1822 	 * or records onto the socket buffer by using inconsistent/stale
1823 	 * versions of the field, possibly resulting in socket buffer
1824 	 * corruption.
1825 	 *
1826 	 * By holding the high-level sblock(), we prevent simultaneous
1827 	 * readers from pulling off the front of the socket buffer.
1828 	 */
1829 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1830 	if (uio->uio_td)
1831 		uio->uio_td->td_ru.ru_msgrcv++;
1832 	KASSERT(m == so->so_rcv.sb_mb, ("soreceive: m != so->so_rcv.sb_mb"));
1833 	SBLASTRECORDCHK(&so->so_rcv);
1834 	SBLASTMBUFCHK(&so->so_rcv);
1835 	nextrecord = m->m_nextpkt;
1836 	if (pr->pr_flags & PR_ADDR) {
1837 		KASSERT(m->m_type == MT_SONAME,
1838 		    ("m->m_type == %d", m->m_type));
1839 		orig_resid = 0;
1840 		if (psa != NULL)
1841 			*psa = sodupsockaddr(mtod(m, struct sockaddr *),
1842 			    M_NOWAIT);
1843 		if (flags & MSG_PEEK) {
1844 			m = m->m_next;
1845 		} else {
1846 			sbfree(&so->so_rcv, m);
1847 			so->so_rcv.sb_mb = m_free(m);
1848 			m = so->so_rcv.sb_mb;
1849 			sockbuf_pushsync(&so->so_rcv, nextrecord);
1850 		}
1851 	}
1852 
1853 	/*
1854 	 * Process one or more MT_CONTROL mbufs present before any data mbufs
1855 	 * in the first mbuf chain on the socket buffer.  If MSG_PEEK, we
1856 	 * just copy the data; if !MSG_PEEK, we call into the protocol to
1857 	 * perform externalization (or freeing if controlp == NULL).
1858 	 */
1859 	if (m != NULL && m->m_type == MT_CONTROL) {
1860 		struct mbuf *cm = NULL, *cmn;
1861 		struct mbuf **cme = &cm;
1862 
1863 		do {
1864 			if (flags & MSG_PEEK) {
1865 				if (controlp != NULL) {
1866 					*controlp = m_copym(m, 0, m->m_len,
1867 					    M_NOWAIT);
1868 					controlp = &(*controlp)->m_next;
1869 				}
1870 				m = m->m_next;
1871 			} else {
1872 				sbfree(&so->so_rcv, m);
1873 				so->so_rcv.sb_mb = m->m_next;
1874 				m->m_next = NULL;
1875 				*cme = m;
1876 				cme = &(*cme)->m_next;
1877 				m = so->so_rcv.sb_mb;
1878 			}
1879 		} while (m != NULL && m->m_type == MT_CONTROL);
1880 		if ((flags & MSG_PEEK) == 0)
1881 			sockbuf_pushsync(&so->so_rcv, nextrecord);
1882 		while (cm != NULL) {
1883 			cmn = cm->m_next;
1884 			cm->m_next = NULL;
1885 			if (pr->pr_domain->dom_externalize != NULL) {
1886 				SOCKBUF_UNLOCK(&so->so_rcv);
1887 				VNET_SO_ASSERT(so);
1888 				error = (*pr->pr_domain->dom_externalize)
1889 				    (cm, controlp, flags);
1890 				SOCKBUF_LOCK(&so->so_rcv);
1891 			} else if (controlp != NULL)
1892 				*controlp = cm;
1893 			else
1894 				m_freem(cm);
1895 			if (controlp != NULL) {
1896 				orig_resid = 0;
1897 				while (*controlp != NULL)
1898 					controlp = &(*controlp)->m_next;
1899 			}
1900 			cm = cmn;
1901 		}
1902 		if (m != NULL)
1903 			nextrecord = so->so_rcv.sb_mb->m_nextpkt;
1904 		else
1905 			nextrecord = so->so_rcv.sb_mb;
1906 		orig_resid = 0;
1907 	}
1908 	if (m != NULL) {
1909 		if ((flags & MSG_PEEK) == 0) {
1910 			KASSERT(m->m_nextpkt == nextrecord,
1911 			    ("soreceive: post-control, nextrecord !sync"));
1912 			if (nextrecord == NULL) {
1913 				KASSERT(so->so_rcv.sb_mb == m,
1914 				    ("soreceive: post-control, sb_mb!=m"));
1915 				KASSERT(so->so_rcv.sb_lastrecord == m,
1916 				    ("soreceive: post-control, lastrecord!=m"));
1917 			}
1918 		}
1919 		type = m->m_type;
1920 		if (type == MT_OOBDATA)
1921 			flags |= MSG_OOB;
1922 	} else {
1923 		if ((flags & MSG_PEEK) == 0) {
1924 			KASSERT(so->so_rcv.sb_mb == nextrecord,
1925 			    ("soreceive: sb_mb != nextrecord"));
1926 			if (so->so_rcv.sb_mb == NULL) {
1927 				KASSERT(so->so_rcv.sb_lastrecord == NULL,
1928 				    ("soreceive: sb_lastercord != NULL"));
1929 			}
1930 		}
1931 	}
1932 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1933 	SBLASTRECORDCHK(&so->so_rcv);
1934 	SBLASTMBUFCHK(&so->so_rcv);
1935 
1936 	/*
1937 	 * Now continue to read any data mbufs off of the head of the socket
1938 	 * buffer until the read request is satisfied.  Note that 'type' is
1939 	 * used to store the type of any mbuf reads that have happened so far
1940 	 * such that soreceive() can stop reading if the type changes, which
1941 	 * causes soreceive() to return only one of regular data and inline
1942 	 * out-of-band data in a single socket receive operation.
1943 	 */
1944 	moff = 0;
1945 	offset = 0;
1946 	while (m != NULL && !(m->m_flags & M_NOTAVAIL) && uio->uio_resid > 0
1947 	    && error == 0) {
1948 		/*
1949 		 * If the type of mbuf has changed since the last mbuf
1950 		 * examined ('type'), end the receive operation.
1951 		 */
1952 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1953 		if (m->m_type == MT_OOBDATA || m->m_type == MT_CONTROL) {
1954 			if (type != m->m_type)
1955 				break;
1956 		} else if (type == MT_OOBDATA)
1957 			break;
1958 		else
1959 		    KASSERT(m->m_type == MT_DATA,
1960 			("m->m_type == %d", m->m_type));
1961 		so->so_rcv.sb_state &= ~SBS_RCVATMARK;
1962 		len = uio->uio_resid;
1963 		if (so->so_oobmark && len > so->so_oobmark - offset)
1964 			len = so->so_oobmark - offset;
1965 		if (len > m->m_len - moff)
1966 			len = m->m_len - moff;
1967 		/*
1968 		 * If mp is set, just pass back the mbufs.  Otherwise copy
1969 		 * them out via the uio, then free.  Sockbuf must be
1970 		 * consistent here (points to current mbuf, it points to next
1971 		 * record) when we drop priority; we must note any additions
1972 		 * to the sockbuf when we block interrupts again.
1973 		 */
1974 		if (mp == NULL) {
1975 			SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1976 			SBLASTRECORDCHK(&so->so_rcv);
1977 			SBLASTMBUFCHK(&so->so_rcv);
1978 			SOCKBUF_UNLOCK(&so->so_rcv);
1979 			error = uiomove(mtod(m, char *) + moff, (int)len, uio);
1980 			SOCKBUF_LOCK(&so->so_rcv);
1981 			if (error) {
1982 				/*
1983 				 * The MT_SONAME mbuf has already been removed
1984 				 * from the record, so it is necessary to
1985 				 * remove the data mbufs, if any, to preserve
1986 				 * the invariant in the case of PR_ADDR that
1987 				 * requires MT_SONAME mbufs at the head of
1988 				 * each record.
1989 				 */
1990 				if (pr->pr_flags & PR_ATOMIC &&
1991 				    ((flags & MSG_PEEK) == 0))
1992 					(void)sbdroprecord_locked(&so->so_rcv);
1993 				SOCKBUF_UNLOCK(&so->so_rcv);
1994 				goto release;
1995 			}
1996 		} else
1997 			uio->uio_resid -= len;
1998 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
1999 		if (len == m->m_len - moff) {
2000 			if (m->m_flags & M_EOR)
2001 				flags |= MSG_EOR;
2002 			if (flags & MSG_PEEK) {
2003 				m = m->m_next;
2004 				moff = 0;
2005 			} else {
2006 				nextrecord = m->m_nextpkt;
2007 				sbfree(&so->so_rcv, m);
2008 				if (mp != NULL) {
2009 					m->m_nextpkt = NULL;
2010 					*mp = m;
2011 					mp = &m->m_next;
2012 					so->so_rcv.sb_mb = m = m->m_next;
2013 					*mp = NULL;
2014 				} else {
2015 					so->so_rcv.sb_mb = m_free(m);
2016 					m = so->so_rcv.sb_mb;
2017 				}
2018 				sockbuf_pushsync(&so->so_rcv, nextrecord);
2019 				SBLASTRECORDCHK(&so->so_rcv);
2020 				SBLASTMBUFCHK(&so->so_rcv);
2021 			}
2022 		} else {
2023 			if (flags & MSG_PEEK)
2024 				moff += len;
2025 			else {
2026 				if (mp != NULL) {
2027 					if (flags & MSG_DONTWAIT) {
2028 						*mp = m_copym(m, 0, len,
2029 						    M_NOWAIT);
2030 						if (*mp == NULL) {
2031 							/*
2032 							 * m_copym() couldn't
2033 							 * allocate an mbuf.
2034 							 * Adjust uio_resid back
2035 							 * (it was adjusted
2036 							 * down by len bytes,
2037 							 * which we didn't end
2038 							 * up "copying" over).
2039 							 */
2040 							uio->uio_resid += len;
2041 							break;
2042 						}
2043 					} else {
2044 						SOCKBUF_UNLOCK(&so->so_rcv);
2045 						*mp = m_copym(m, 0, len,
2046 						    M_WAITOK);
2047 						SOCKBUF_LOCK(&so->so_rcv);
2048 					}
2049 				}
2050 				sbcut_locked(&so->so_rcv, len);
2051 			}
2052 		}
2053 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2054 		if (so->so_oobmark) {
2055 			if ((flags & MSG_PEEK) == 0) {
2056 				so->so_oobmark -= len;
2057 				if (so->so_oobmark == 0) {
2058 					so->so_rcv.sb_state |= SBS_RCVATMARK;
2059 					break;
2060 				}
2061 			} else {
2062 				offset += len;
2063 				if (offset == so->so_oobmark)
2064 					break;
2065 			}
2066 		}
2067 		if (flags & MSG_EOR)
2068 			break;
2069 		/*
2070 		 * If the MSG_WAITALL flag is set (for non-atomic socket), we
2071 		 * must not quit until "uio->uio_resid == 0" or an error
2072 		 * termination.  If a signal/timeout occurs, return with a
2073 		 * short count but without error.  Keep sockbuf locked
2074 		 * against other readers.
2075 		 */
2076 		while (flags & MSG_WAITALL && m == NULL && uio->uio_resid > 0 &&
2077 		    !sosendallatonce(so) && nextrecord == NULL) {
2078 			SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2079 			if (so->so_error ||
2080 			    so->so_rcv.sb_state & SBS_CANTRCVMORE)
2081 				break;
2082 			/*
2083 			 * Notify the protocol that some data has been
2084 			 * drained before blocking.
2085 			 */
2086 			if (pr->pr_flags & PR_WANTRCVD) {
2087 				SOCKBUF_UNLOCK(&so->so_rcv);
2088 				VNET_SO_ASSERT(so);
2089 				(*pr->pr_usrreqs->pru_rcvd)(so, flags);
2090 				SOCKBUF_LOCK(&so->so_rcv);
2091 			}
2092 			SBLASTRECORDCHK(&so->so_rcv);
2093 			SBLASTMBUFCHK(&so->so_rcv);
2094 			/*
2095 			 * We could receive some data while was notifying
2096 			 * the protocol. Skip blocking in this case.
2097 			 */
2098 			if (so->so_rcv.sb_mb == NULL) {
2099 				error = sbwait(&so->so_rcv);
2100 				if (error) {
2101 					SOCKBUF_UNLOCK(&so->so_rcv);
2102 					goto release;
2103 				}
2104 			}
2105 			m = so->so_rcv.sb_mb;
2106 			if (m != NULL)
2107 				nextrecord = m->m_nextpkt;
2108 		}
2109 	}
2110 
2111 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2112 	if (m != NULL && pr->pr_flags & PR_ATOMIC) {
2113 		flags |= MSG_TRUNC;
2114 		if ((flags & MSG_PEEK) == 0)
2115 			(void) sbdroprecord_locked(&so->so_rcv);
2116 	}
2117 	if ((flags & MSG_PEEK) == 0) {
2118 		if (m == NULL) {
2119 			/*
2120 			 * First part is an inline SB_EMPTY_FIXUP().  Second
2121 			 * part makes sure sb_lastrecord is up-to-date if
2122 			 * there is still data in the socket buffer.
2123 			 */
2124 			so->so_rcv.sb_mb = nextrecord;
2125 			if (so->so_rcv.sb_mb == NULL) {
2126 				so->so_rcv.sb_mbtail = NULL;
2127 				so->so_rcv.sb_lastrecord = NULL;
2128 			} else if (nextrecord->m_nextpkt == NULL)
2129 				so->so_rcv.sb_lastrecord = nextrecord;
2130 		}
2131 		SBLASTRECORDCHK(&so->so_rcv);
2132 		SBLASTMBUFCHK(&so->so_rcv);
2133 		/*
2134 		 * If soreceive() is being done from the socket callback,
2135 		 * then don't need to generate ACK to peer to update window,
2136 		 * since ACK will be generated on return to TCP.
2137 		 */
2138 		if (!(flags & MSG_SOCALLBCK) &&
2139 		    (pr->pr_flags & PR_WANTRCVD)) {
2140 			SOCKBUF_UNLOCK(&so->so_rcv);
2141 			VNET_SO_ASSERT(so);
2142 			(*pr->pr_usrreqs->pru_rcvd)(so, flags);
2143 			SOCKBUF_LOCK(&so->so_rcv);
2144 		}
2145 	}
2146 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2147 	if (orig_resid == uio->uio_resid && orig_resid &&
2148 	    (flags & MSG_EOR) == 0 && (so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0) {
2149 		SOCKBUF_UNLOCK(&so->so_rcv);
2150 		goto restart;
2151 	}
2152 	SOCKBUF_UNLOCK(&so->so_rcv);
2153 
2154 	if (flagsp != NULL)
2155 		*flagsp |= flags;
2156 release:
2157 	sbunlock(&so->so_rcv);
2158 	return (error);
2159 }
2160 
2161 /*
2162  * Optimized version of soreceive() for stream (TCP) sockets.
2163  * XXXAO: (MSG_WAITALL | MSG_PEEK) isn't properly handled.
2164  */
2165 int
2166 soreceive_stream(struct socket *so, struct sockaddr **psa, struct uio *uio,
2167     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2168 {
2169 	int len = 0, error = 0, flags, oresid;
2170 	struct sockbuf *sb;
2171 	struct mbuf *m, *n = NULL;
2172 
2173 	/* We only do stream sockets. */
2174 	if (so->so_type != SOCK_STREAM)
2175 		return (EINVAL);
2176 	if (psa != NULL)
2177 		*psa = NULL;
2178 	if (controlp != NULL)
2179 		return (EINVAL);
2180 	if (flagsp != NULL)
2181 		flags = *flagsp &~ MSG_EOR;
2182 	else
2183 		flags = 0;
2184 	if (flags & MSG_OOB)
2185 		return (soreceive_rcvoob(so, uio, flags));
2186 	if (mp0 != NULL)
2187 		*mp0 = NULL;
2188 
2189 	sb = &so->so_rcv;
2190 
2191 	/* Prevent other readers from entering the socket. */
2192 	error = sblock(sb, SBLOCKWAIT(flags));
2193 	if (error)
2194 		goto out;
2195 	SOCKBUF_LOCK(sb);
2196 
2197 	/* Easy one, no space to copyout anything. */
2198 	if (uio->uio_resid == 0) {
2199 		error = EINVAL;
2200 		goto out;
2201 	}
2202 	oresid = uio->uio_resid;
2203 
2204 	/* We will never ever get anything unless we are or were connected. */
2205 	if (!(so->so_state & (SS_ISCONNECTED|SS_ISDISCONNECTED))) {
2206 		error = ENOTCONN;
2207 		goto out;
2208 	}
2209 
2210 restart:
2211 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2212 
2213 	/* Abort if socket has reported problems. */
2214 	if (so->so_error) {
2215 		if (sbavail(sb) > 0)
2216 			goto deliver;
2217 		if (oresid > uio->uio_resid)
2218 			goto out;
2219 		error = so->so_error;
2220 		if (!(flags & MSG_PEEK))
2221 			so->so_error = 0;
2222 		goto out;
2223 	}
2224 
2225 	/* Door is closed.  Deliver what is left, if any. */
2226 	if (sb->sb_state & SBS_CANTRCVMORE) {
2227 		if (sbavail(sb) > 0)
2228 			goto deliver;
2229 		else
2230 			goto out;
2231 	}
2232 
2233 	/* Socket buffer is empty and we shall not block. */
2234 	if (sbavail(sb) == 0 &&
2235 	    ((so->so_state & SS_NBIO) || (flags & (MSG_DONTWAIT|MSG_NBIO)))) {
2236 		error = EAGAIN;
2237 		goto out;
2238 	}
2239 
2240 	/* Socket buffer got some data that we shall deliver now. */
2241 	if (sbavail(sb) > 0 && !(flags & MSG_WAITALL) &&
2242 	    ((so->so_state & SS_NBIO) ||
2243 	     (flags & (MSG_DONTWAIT|MSG_NBIO)) ||
2244 	     sbavail(sb) >= sb->sb_lowat ||
2245 	     sbavail(sb) >= uio->uio_resid ||
2246 	     sbavail(sb) >= sb->sb_hiwat) ) {
2247 		goto deliver;
2248 	}
2249 
2250 	/* On MSG_WAITALL we must wait until all data or error arrives. */
2251 	if ((flags & MSG_WAITALL) &&
2252 	    (sbavail(sb) >= uio->uio_resid || sbavail(sb) >= sb->sb_hiwat))
2253 		goto deliver;
2254 
2255 	/*
2256 	 * Wait and block until (more) data comes in.
2257 	 * NB: Drops the sockbuf lock during wait.
2258 	 */
2259 	error = sbwait(sb);
2260 	if (error)
2261 		goto out;
2262 	goto restart;
2263 
2264 deliver:
2265 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2266 	KASSERT(sbavail(sb) > 0, ("%s: sockbuf empty", __func__));
2267 	KASSERT(sb->sb_mb != NULL, ("%s: sb_mb == NULL", __func__));
2268 
2269 	/* Statistics. */
2270 	if (uio->uio_td)
2271 		uio->uio_td->td_ru.ru_msgrcv++;
2272 
2273 	/* Fill uio until full or current end of socket buffer is reached. */
2274 	len = min(uio->uio_resid, sbavail(sb));
2275 	if (mp0 != NULL) {
2276 		/* Dequeue as many mbufs as possible. */
2277 		if (!(flags & MSG_PEEK) && len >= sb->sb_mb->m_len) {
2278 			if (*mp0 == NULL)
2279 				*mp0 = sb->sb_mb;
2280 			else
2281 				m_cat(*mp0, sb->sb_mb);
2282 			for (m = sb->sb_mb;
2283 			     m != NULL && m->m_len <= len;
2284 			     m = m->m_next) {
2285 				KASSERT(!(m->m_flags & M_NOTAVAIL),
2286 				    ("%s: m %p not available", __func__, m));
2287 				len -= m->m_len;
2288 				uio->uio_resid -= m->m_len;
2289 				sbfree(sb, m);
2290 				n = m;
2291 			}
2292 			n->m_next = NULL;
2293 			sb->sb_mb = m;
2294 			sb->sb_lastrecord = sb->sb_mb;
2295 			if (sb->sb_mb == NULL)
2296 				SB_EMPTY_FIXUP(sb);
2297 		}
2298 		/* Copy the remainder. */
2299 		if (len > 0) {
2300 			KASSERT(sb->sb_mb != NULL,
2301 			    ("%s: len > 0 && sb->sb_mb empty", __func__));
2302 
2303 			m = m_copym(sb->sb_mb, 0, len, M_NOWAIT);
2304 			if (m == NULL)
2305 				len = 0;	/* Don't flush data from sockbuf. */
2306 			else
2307 				uio->uio_resid -= len;
2308 			if (*mp0 != NULL)
2309 				m_cat(*mp0, m);
2310 			else
2311 				*mp0 = m;
2312 			if (*mp0 == NULL) {
2313 				error = ENOBUFS;
2314 				goto out;
2315 			}
2316 		}
2317 	} else {
2318 		/* NB: Must unlock socket buffer as uiomove may sleep. */
2319 		SOCKBUF_UNLOCK(sb);
2320 		error = m_mbuftouio(uio, sb->sb_mb, len);
2321 		SOCKBUF_LOCK(sb);
2322 		if (error)
2323 			goto out;
2324 	}
2325 	SBLASTRECORDCHK(sb);
2326 	SBLASTMBUFCHK(sb);
2327 
2328 	/*
2329 	 * Remove the delivered data from the socket buffer unless we
2330 	 * were only peeking.
2331 	 */
2332 	if (!(flags & MSG_PEEK)) {
2333 		if (len > 0)
2334 			sbdrop_locked(sb, len);
2335 
2336 		/* Notify protocol that we drained some data. */
2337 		if ((so->so_proto->pr_flags & PR_WANTRCVD) &&
2338 		    (((flags & MSG_WAITALL) && uio->uio_resid > 0) ||
2339 		     !(flags & MSG_SOCALLBCK))) {
2340 			SOCKBUF_UNLOCK(sb);
2341 			VNET_SO_ASSERT(so);
2342 			(*so->so_proto->pr_usrreqs->pru_rcvd)(so, flags);
2343 			SOCKBUF_LOCK(sb);
2344 		}
2345 	}
2346 
2347 	/*
2348 	 * For MSG_WAITALL we may have to loop again and wait for
2349 	 * more data to come in.
2350 	 */
2351 	if ((flags & MSG_WAITALL) && uio->uio_resid > 0)
2352 		goto restart;
2353 out:
2354 	SOCKBUF_LOCK_ASSERT(sb);
2355 	SBLASTRECORDCHK(sb);
2356 	SBLASTMBUFCHK(sb);
2357 	SOCKBUF_UNLOCK(sb);
2358 	sbunlock(sb);
2359 	return (error);
2360 }
2361 
2362 /*
2363  * Optimized version of soreceive() for simple datagram cases from userspace.
2364  * Unlike in the stream case, we're able to drop a datagram if copyout()
2365  * fails, and because we handle datagrams atomically, we don't need to use a
2366  * sleep lock to prevent I/O interlacing.
2367  */
2368 int
2369 soreceive_dgram(struct socket *so, struct sockaddr **psa, struct uio *uio,
2370     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2371 {
2372 	struct mbuf *m, *m2;
2373 	int flags, error;
2374 	ssize_t len;
2375 	struct protosw *pr = so->so_proto;
2376 	struct mbuf *nextrecord;
2377 
2378 	if (psa != NULL)
2379 		*psa = NULL;
2380 	if (controlp != NULL)
2381 		*controlp = NULL;
2382 	if (flagsp != NULL)
2383 		flags = *flagsp &~ MSG_EOR;
2384 	else
2385 		flags = 0;
2386 
2387 	/*
2388 	 * For any complicated cases, fall back to the full
2389 	 * soreceive_generic().
2390 	 */
2391 	if (mp0 != NULL || (flags & MSG_PEEK) || (flags & MSG_OOB))
2392 		return (soreceive_generic(so, psa, uio, mp0, controlp,
2393 		    flagsp));
2394 
2395 	/*
2396 	 * Enforce restrictions on use.
2397 	 */
2398 	KASSERT((pr->pr_flags & PR_WANTRCVD) == 0,
2399 	    ("soreceive_dgram: wantrcvd"));
2400 	KASSERT(pr->pr_flags & PR_ATOMIC, ("soreceive_dgram: !atomic"));
2401 	KASSERT((so->so_rcv.sb_state & SBS_RCVATMARK) == 0,
2402 	    ("soreceive_dgram: SBS_RCVATMARK"));
2403 	KASSERT((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0,
2404 	    ("soreceive_dgram: P_CONNREQUIRED"));
2405 
2406 	/*
2407 	 * Loop blocking while waiting for a datagram.
2408 	 */
2409 	SOCKBUF_LOCK(&so->so_rcv);
2410 	while ((m = so->so_rcv.sb_mb) == NULL) {
2411 		KASSERT(sbavail(&so->so_rcv) == 0,
2412 		    ("soreceive_dgram: sb_mb NULL but sbavail %u",
2413 		    sbavail(&so->so_rcv)));
2414 		if (so->so_error) {
2415 			error = so->so_error;
2416 			so->so_error = 0;
2417 			SOCKBUF_UNLOCK(&so->so_rcv);
2418 			return (error);
2419 		}
2420 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE ||
2421 		    uio->uio_resid == 0) {
2422 			SOCKBUF_UNLOCK(&so->so_rcv);
2423 			return (0);
2424 		}
2425 		if ((so->so_state & SS_NBIO) ||
2426 		    (flags & (MSG_DONTWAIT|MSG_NBIO))) {
2427 			SOCKBUF_UNLOCK(&so->so_rcv);
2428 			return (EWOULDBLOCK);
2429 		}
2430 		SBLASTRECORDCHK(&so->so_rcv);
2431 		SBLASTMBUFCHK(&so->so_rcv);
2432 		error = sbwait(&so->so_rcv);
2433 		if (error) {
2434 			SOCKBUF_UNLOCK(&so->so_rcv);
2435 			return (error);
2436 		}
2437 	}
2438 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2439 
2440 	if (uio->uio_td)
2441 		uio->uio_td->td_ru.ru_msgrcv++;
2442 	SBLASTRECORDCHK(&so->so_rcv);
2443 	SBLASTMBUFCHK(&so->so_rcv);
2444 	nextrecord = m->m_nextpkt;
2445 	if (nextrecord == NULL) {
2446 		KASSERT(so->so_rcv.sb_lastrecord == m,
2447 		    ("soreceive_dgram: lastrecord != m"));
2448 	}
2449 
2450 	KASSERT(so->so_rcv.sb_mb->m_nextpkt == nextrecord,
2451 	    ("soreceive_dgram: m_nextpkt != nextrecord"));
2452 
2453 	/*
2454 	 * Pull 'm' and its chain off the front of the packet queue.
2455 	 */
2456 	so->so_rcv.sb_mb = NULL;
2457 	sockbuf_pushsync(&so->so_rcv, nextrecord);
2458 
2459 	/*
2460 	 * Walk 'm's chain and free that many bytes from the socket buffer.
2461 	 */
2462 	for (m2 = m; m2 != NULL; m2 = m2->m_next)
2463 		sbfree(&so->so_rcv, m2);
2464 
2465 	/*
2466 	 * Do a few last checks before we let go of the lock.
2467 	 */
2468 	SBLASTRECORDCHK(&so->so_rcv);
2469 	SBLASTMBUFCHK(&so->so_rcv);
2470 	SOCKBUF_UNLOCK(&so->so_rcv);
2471 
2472 	if (pr->pr_flags & PR_ADDR) {
2473 		KASSERT(m->m_type == MT_SONAME,
2474 		    ("m->m_type == %d", m->m_type));
2475 		if (psa != NULL)
2476 			*psa = sodupsockaddr(mtod(m, struct sockaddr *),
2477 			    M_NOWAIT);
2478 		m = m_free(m);
2479 	}
2480 	if (m == NULL) {
2481 		/* XXXRW: Can this happen? */
2482 		return (0);
2483 	}
2484 
2485 	/*
2486 	 * Packet to copyout() is now in 'm' and it is disconnected from the
2487 	 * queue.
2488 	 *
2489 	 * Process one or more MT_CONTROL mbufs present before any data mbufs
2490 	 * in the first mbuf chain on the socket buffer.  We call into the
2491 	 * protocol to perform externalization (or freeing if controlp ==
2492 	 * NULL). In some cases there can be only MT_CONTROL mbufs without
2493 	 * MT_DATA mbufs.
2494 	 */
2495 	if (m->m_type == MT_CONTROL) {
2496 		struct mbuf *cm = NULL, *cmn;
2497 		struct mbuf **cme = &cm;
2498 
2499 		do {
2500 			m2 = m->m_next;
2501 			m->m_next = NULL;
2502 			*cme = m;
2503 			cme = &(*cme)->m_next;
2504 			m = m2;
2505 		} while (m != NULL && m->m_type == MT_CONTROL);
2506 		while (cm != NULL) {
2507 			cmn = cm->m_next;
2508 			cm->m_next = NULL;
2509 			if (pr->pr_domain->dom_externalize != NULL) {
2510 				error = (*pr->pr_domain->dom_externalize)
2511 				    (cm, controlp, flags);
2512 			} else if (controlp != NULL)
2513 				*controlp = cm;
2514 			else
2515 				m_freem(cm);
2516 			if (controlp != NULL) {
2517 				while (*controlp != NULL)
2518 					controlp = &(*controlp)->m_next;
2519 			}
2520 			cm = cmn;
2521 		}
2522 	}
2523 	KASSERT(m == NULL || m->m_type == MT_DATA,
2524 	    ("soreceive_dgram: !data"));
2525 	while (m != NULL && uio->uio_resid > 0) {
2526 		len = uio->uio_resid;
2527 		if (len > m->m_len)
2528 			len = m->m_len;
2529 		error = uiomove(mtod(m, char *), (int)len, uio);
2530 		if (error) {
2531 			m_freem(m);
2532 			return (error);
2533 		}
2534 		if (len == m->m_len)
2535 			m = m_free(m);
2536 		else {
2537 			m->m_data += len;
2538 			m->m_len -= len;
2539 		}
2540 	}
2541 	if (m != NULL) {
2542 		flags |= MSG_TRUNC;
2543 		m_freem(m);
2544 	}
2545 	if (flagsp != NULL)
2546 		*flagsp |= flags;
2547 	return (0);
2548 }
2549 
2550 int
2551 soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
2552     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2553 {
2554 	int error;
2555 
2556 	CURVNET_SET(so->so_vnet);
2557 	if (!SOLISTENING(so))
2558 		error = (so->so_proto->pr_usrreqs->pru_soreceive(so, psa, uio,
2559 		    mp0, controlp, flagsp));
2560 	else
2561 		error = ENOTCONN;
2562 	CURVNET_RESTORE();
2563 	return (error);
2564 }
2565 
2566 int
2567 soshutdown(struct socket *so, int how)
2568 {
2569 	struct protosw *pr = so->so_proto;
2570 	int error, soerror_enotconn;
2571 
2572 	if (!(how == SHUT_RD || how == SHUT_WR || how == SHUT_RDWR))
2573 		return (EINVAL);
2574 
2575 	soerror_enotconn = 0;
2576 	if ((so->so_state &
2577 	    (SS_ISCONNECTED | SS_ISCONNECTING | SS_ISDISCONNECTING)) == 0) {
2578 		/*
2579 		 * POSIX mandates us to return ENOTCONN when shutdown(2) is
2580 		 * invoked on a datagram sockets, however historically we would
2581 		 * actually tear socket down. This is known to be leveraged by
2582 		 * some applications to unblock process waiting in recvXXX(2)
2583 		 * by other process that it shares that socket with. Try to meet
2584 		 * both backward-compatibility and POSIX requirements by forcing
2585 		 * ENOTCONN but still asking protocol to perform pru_shutdown().
2586 		 */
2587 		if (so->so_type != SOCK_DGRAM)
2588 			return (ENOTCONN);
2589 		soerror_enotconn = 1;
2590 	}
2591 
2592 	CURVNET_SET(so->so_vnet);
2593 	if (pr->pr_usrreqs->pru_flush != NULL)
2594 		(*pr->pr_usrreqs->pru_flush)(so, how);
2595 	if (how != SHUT_WR)
2596 		sorflush(so);
2597 	if (how != SHUT_RD) {
2598 		error = (*pr->pr_usrreqs->pru_shutdown)(so);
2599 		wakeup(&so->so_timeo);
2600 		CURVNET_RESTORE();
2601 		return ((error == 0 && soerror_enotconn) ? ENOTCONN : error);
2602 	}
2603 	wakeup(&so->so_timeo);
2604 	CURVNET_RESTORE();
2605 
2606 	return (soerror_enotconn ? ENOTCONN : 0);
2607 }
2608 
2609 void
2610 sorflush(struct socket *so)
2611 {
2612 	struct sockbuf *sb = &so->so_rcv;
2613 	struct protosw *pr = so->so_proto;
2614 	struct socket aso;
2615 
2616 	VNET_SO_ASSERT(so);
2617 
2618 	/*
2619 	 * In order to avoid calling dom_dispose with the socket buffer mutex
2620 	 * held, and in order to generally avoid holding the lock for a long
2621 	 * time, we make a copy of the socket buffer and clear the original
2622 	 * (except locks, state).  The new socket buffer copy won't have
2623 	 * initialized locks so we can only call routines that won't use or
2624 	 * assert those locks.
2625 	 *
2626 	 * Dislodge threads currently blocked in receive and wait to acquire
2627 	 * a lock against other simultaneous readers before clearing the
2628 	 * socket buffer.  Don't let our acquire be interrupted by a signal
2629 	 * despite any existing socket disposition on interruptable waiting.
2630 	 */
2631 	socantrcvmore(so);
2632 	(void) sblock(sb, SBL_WAIT | SBL_NOINTR);
2633 
2634 	/*
2635 	 * Invalidate/clear most of the sockbuf structure, but leave selinfo
2636 	 * and mutex data unchanged.
2637 	 */
2638 	SOCKBUF_LOCK(sb);
2639 	bzero(&aso, sizeof(aso));
2640 	aso.so_pcb = so->so_pcb;
2641 	bcopy(&sb->sb_startzero, &aso.so_rcv.sb_startzero,
2642 	    sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
2643 	bzero(&sb->sb_startzero,
2644 	    sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
2645 	SOCKBUF_UNLOCK(sb);
2646 	sbunlock(sb);
2647 
2648 	/*
2649 	 * Dispose of special rights and flush the copied socket.  Don't call
2650 	 * any unsafe routines (that rely on locks being initialized) on aso.
2651 	 */
2652 	if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose != NULL)
2653 		(*pr->pr_domain->dom_dispose)(&aso);
2654 	sbrelease_internal(&aso.so_rcv, so);
2655 }
2656 
2657 /*
2658  * Wrapper for Socket established helper hook.
2659  * Parameters: socket, context of the hook point, hook id.
2660  */
2661 static int inline
2662 hhook_run_socket(struct socket *so, void *hctx, int32_t h_id)
2663 {
2664 	struct socket_hhook_data hhook_data = {
2665 		.so = so,
2666 		.hctx = hctx,
2667 		.m = NULL,
2668 		.status = 0
2669 	};
2670 
2671 	CURVNET_SET(so->so_vnet);
2672 	HHOOKS_RUN_IF(V_socket_hhh[h_id], &hhook_data, &so->osd);
2673 	CURVNET_RESTORE();
2674 
2675 	/* Ugly but needed, since hhooks return void for now */
2676 	return (hhook_data.status);
2677 }
2678 
2679 /*
2680  * Perhaps this routine, and sooptcopyout(), below, ought to come in an
2681  * additional variant to handle the case where the option value needs to be
2682  * some kind of integer, but not a specific size.  In addition to their use
2683  * here, these functions are also called by the protocol-level pr_ctloutput()
2684  * routines.
2685  */
2686 int
2687 sooptcopyin(struct sockopt *sopt, void *buf, size_t len, size_t minlen)
2688 {
2689 	size_t	valsize;
2690 
2691 	/*
2692 	 * If the user gives us more than we wanted, we ignore it, but if we
2693 	 * don't get the minimum length the caller wants, we return EINVAL.
2694 	 * On success, sopt->sopt_valsize is set to however much we actually
2695 	 * retrieved.
2696 	 */
2697 	if ((valsize = sopt->sopt_valsize) < minlen)
2698 		return EINVAL;
2699 	if (valsize > len)
2700 		sopt->sopt_valsize = valsize = len;
2701 
2702 	if (sopt->sopt_td != NULL)
2703 		return (copyin(sopt->sopt_val, buf, valsize));
2704 
2705 	bcopy(sopt->sopt_val, buf, valsize);
2706 	return (0);
2707 }
2708 
2709 /*
2710  * Kernel version of setsockopt(2).
2711  *
2712  * XXX: optlen is size_t, not socklen_t
2713  */
2714 int
2715 so_setsockopt(struct socket *so, int level, int optname, void *optval,
2716     size_t optlen)
2717 {
2718 	struct sockopt sopt;
2719 
2720 	sopt.sopt_level = level;
2721 	sopt.sopt_name = optname;
2722 	sopt.sopt_dir = SOPT_SET;
2723 	sopt.sopt_val = optval;
2724 	sopt.sopt_valsize = optlen;
2725 	sopt.sopt_td = NULL;
2726 	return (sosetopt(so, &sopt));
2727 }
2728 
2729 int
2730 sosetopt(struct socket *so, struct sockopt *sopt)
2731 {
2732 	int	error, optval;
2733 	struct	linger l;
2734 	struct	timeval tv;
2735 	sbintime_t val;
2736 	uint32_t val32;
2737 #ifdef MAC
2738 	struct mac extmac;
2739 #endif
2740 
2741 	CURVNET_SET(so->so_vnet);
2742 	error = 0;
2743 	if (sopt->sopt_level != SOL_SOCKET) {
2744 		if (so->so_proto->pr_ctloutput != NULL) {
2745 			error = (*so->so_proto->pr_ctloutput)(so, sopt);
2746 			CURVNET_RESTORE();
2747 			return (error);
2748 		}
2749 		error = ENOPROTOOPT;
2750 	} else {
2751 		switch (sopt->sopt_name) {
2752 		case SO_ACCEPTFILTER:
2753 			error = accept_filt_setopt(so, sopt);
2754 			if (error)
2755 				goto bad;
2756 			break;
2757 
2758 		case SO_LINGER:
2759 			error = sooptcopyin(sopt, &l, sizeof l, sizeof l);
2760 			if (error)
2761 				goto bad;
2762 
2763 			SOCK_LOCK(so);
2764 			so->so_linger = l.l_linger;
2765 			if (l.l_onoff)
2766 				so->so_options |= SO_LINGER;
2767 			else
2768 				so->so_options &= ~SO_LINGER;
2769 			SOCK_UNLOCK(so);
2770 			break;
2771 
2772 		case SO_DEBUG:
2773 		case SO_KEEPALIVE:
2774 		case SO_DONTROUTE:
2775 		case SO_USELOOPBACK:
2776 		case SO_BROADCAST:
2777 		case SO_REUSEADDR:
2778 		case SO_REUSEPORT:
2779 		case SO_OOBINLINE:
2780 		case SO_TIMESTAMP:
2781 		case SO_BINTIME:
2782 		case SO_NOSIGPIPE:
2783 		case SO_NO_DDP:
2784 		case SO_NO_OFFLOAD:
2785 			error = sooptcopyin(sopt, &optval, sizeof optval,
2786 			    sizeof optval);
2787 			if (error)
2788 				goto bad;
2789 			SOCK_LOCK(so);
2790 			if (optval)
2791 				so->so_options |= sopt->sopt_name;
2792 			else
2793 				so->so_options &= ~sopt->sopt_name;
2794 			SOCK_UNLOCK(so);
2795 			break;
2796 
2797 		case SO_SETFIB:
2798 			error = sooptcopyin(sopt, &optval, sizeof optval,
2799 			    sizeof optval);
2800 			if (error)
2801 				goto bad;
2802 
2803 			if (optval < 0 || optval >= rt_numfibs) {
2804 				error = EINVAL;
2805 				goto bad;
2806 			}
2807 			if (((so->so_proto->pr_domain->dom_family == PF_INET) ||
2808 			   (so->so_proto->pr_domain->dom_family == PF_INET6) ||
2809 			   (so->so_proto->pr_domain->dom_family == PF_ROUTE)))
2810 				so->so_fibnum = optval;
2811 			else
2812 				so->so_fibnum = 0;
2813 			break;
2814 
2815 		case SO_USER_COOKIE:
2816 			error = sooptcopyin(sopt, &val32, sizeof val32,
2817 			    sizeof val32);
2818 			if (error)
2819 				goto bad;
2820 			so->so_user_cookie = val32;
2821 			break;
2822 
2823 		case SO_SNDBUF:
2824 		case SO_RCVBUF:
2825 		case SO_SNDLOWAT:
2826 		case SO_RCVLOWAT:
2827 			error = sooptcopyin(sopt, &optval, sizeof optval,
2828 			    sizeof optval);
2829 			if (error)
2830 				goto bad;
2831 
2832 			/*
2833 			 * Values < 1 make no sense for any of these options,
2834 			 * so disallow them.
2835 			 */
2836 			if (optval < 1) {
2837 				error = EINVAL;
2838 				goto bad;
2839 			}
2840 
2841 			error = sbsetopt(so, sopt->sopt_name, optval);
2842 			break;
2843 
2844 		case SO_SNDTIMEO:
2845 		case SO_RCVTIMEO:
2846 #ifdef COMPAT_FREEBSD32
2847 			if (SV_CURPROC_FLAG(SV_ILP32)) {
2848 				struct timeval32 tv32;
2849 
2850 				error = sooptcopyin(sopt, &tv32, sizeof tv32,
2851 				    sizeof tv32);
2852 				CP(tv32, tv, tv_sec);
2853 				CP(tv32, tv, tv_usec);
2854 			} else
2855 #endif
2856 				error = sooptcopyin(sopt, &tv, sizeof tv,
2857 				    sizeof tv);
2858 			if (error)
2859 				goto bad;
2860 			if (tv.tv_sec < 0 || tv.tv_usec < 0 ||
2861 			    tv.tv_usec >= 1000000) {
2862 				error = EDOM;
2863 				goto bad;
2864 			}
2865 			if (tv.tv_sec > INT32_MAX)
2866 				val = SBT_MAX;
2867 			else
2868 				val = tvtosbt(tv);
2869 			switch (sopt->sopt_name) {
2870 			case SO_SNDTIMEO:
2871 				so->so_snd.sb_timeo = val;
2872 				break;
2873 			case SO_RCVTIMEO:
2874 				so->so_rcv.sb_timeo = val;
2875 				break;
2876 			}
2877 			break;
2878 
2879 		case SO_LABEL:
2880 #ifdef MAC
2881 			error = sooptcopyin(sopt, &extmac, sizeof extmac,
2882 			    sizeof extmac);
2883 			if (error)
2884 				goto bad;
2885 			error = mac_setsockopt_label(sopt->sopt_td->td_ucred,
2886 			    so, &extmac);
2887 #else
2888 			error = EOPNOTSUPP;
2889 #endif
2890 			break;
2891 
2892 		case SO_TS_CLOCK:
2893 			error = sooptcopyin(sopt, &optval, sizeof optval,
2894 			    sizeof optval);
2895 			if (error)
2896 				goto bad;
2897 			if (optval < 0 || optval > SO_TS_CLOCK_MAX) {
2898 				error = EINVAL;
2899 				goto bad;
2900 			}
2901 			so->so_ts_clock = optval;
2902 			break;
2903 
2904 		case SO_MAX_PACING_RATE:
2905 			error = sooptcopyin(sopt, &val32, sizeof(val32),
2906 			    sizeof(val32));
2907 			if (error)
2908 				goto bad;
2909 			so->so_max_pacing_rate = val32;
2910 			break;
2911 
2912 		default:
2913 			if (V_socket_hhh[HHOOK_SOCKET_OPT]->hhh_nhooks > 0)
2914 				error = hhook_run_socket(so, sopt,
2915 				    HHOOK_SOCKET_OPT);
2916 			else
2917 				error = ENOPROTOOPT;
2918 			break;
2919 		}
2920 		if (error == 0 && so->so_proto->pr_ctloutput != NULL)
2921 			(void)(*so->so_proto->pr_ctloutput)(so, sopt);
2922 	}
2923 bad:
2924 	CURVNET_RESTORE();
2925 	return (error);
2926 }
2927 
2928 /*
2929  * Helper routine for getsockopt.
2930  */
2931 int
2932 sooptcopyout(struct sockopt *sopt, const void *buf, size_t len)
2933 {
2934 	int	error;
2935 	size_t	valsize;
2936 
2937 	error = 0;
2938 
2939 	/*
2940 	 * Documented get behavior is that we always return a value, possibly
2941 	 * truncated to fit in the user's buffer.  Traditional behavior is
2942 	 * that we always tell the user precisely how much we copied, rather
2943 	 * than something useful like the total amount we had available for
2944 	 * her.  Note that this interface is not idempotent; the entire
2945 	 * answer must be generated ahead of time.
2946 	 */
2947 	valsize = min(len, sopt->sopt_valsize);
2948 	sopt->sopt_valsize = valsize;
2949 	if (sopt->sopt_val != NULL) {
2950 		if (sopt->sopt_td != NULL)
2951 			error = copyout(buf, sopt->sopt_val, valsize);
2952 		else
2953 			bcopy(buf, sopt->sopt_val, valsize);
2954 	}
2955 	return (error);
2956 }
2957 
2958 int
2959 sogetopt(struct socket *so, struct sockopt *sopt)
2960 {
2961 	int	error, optval;
2962 	struct	linger l;
2963 	struct	timeval tv;
2964 #ifdef MAC
2965 	struct mac extmac;
2966 #endif
2967 
2968 	CURVNET_SET(so->so_vnet);
2969 	error = 0;
2970 	if (sopt->sopt_level != SOL_SOCKET) {
2971 		if (so->so_proto->pr_ctloutput != NULL)
2972 			error = (*so->so_proto->pr_ctloutput)(so, sopt);
2973 		else
2974 			error = ENOPROTOOPT;
2975 		CURVNET_RESTORE();
2976 		return (error);
2977 	} else {
2978 		switch (sopt->sopt_name) {
2979 		case SO_ACCEPTFILTER:
2980 			error = accept_filt_getopt(so, sopt);
2981 			break;
2982 
2983 		case SO_LINGER:
2984 			SOCK_LOCK(so);
2985 			l.l_onoff = so->so_options & SO_LINGER;
2986 			l.l_linger = so->so_linger;
2987 			SOCK_UNLOCK(so);
2988 			error = sooptcopyout(sopt, &l, sizeof l);
2989 			break;
2990 
2991 		case SO_USELOOPBACK:
2992 		case SO_DONTROUTE:
2993 		case SO_DEBUG:
2994 		case SO_KEEPALIVE:
2995 		case SO_REUSEADDR:
2996 		case SO_REUSEPORT:
2997 		case SO_BROADCAST:
2998 		case SO_OOBINLINE:
2999 		case SO_ACCEPTCONN:
3000 		case SO_TIMESTAMP:
3001 		case SO_BINTIME:
3002 		case SO_NOSIGPIPE:
3003 			optval = so->so_options & sopt->sopt_name;
3004 integer:
3005 			error = sooptcopyout(sopt, &optval, sizeof optval);
3006 			break;
3007 
3008 		case SO_TYPE:
3009 			optval = so->so_type;
3010 			goto integer;
3011 
3012 		case SO_PROTOCOL:
3013 			optval = so->so_proto->pr_protocol;
3014 			goto integer;
3015 
3016 		case SO_ERROR:
3017 			SOCK_LOCK(so);
3018 			optval = so->so_error;
3019 			so->so_error = 0;
3020 			SOCK_UNLOCK(so);
3021 			goto integer;
3022 
3023 		case SO_SNDBUF:
3024 			optval = SOLISTENING(so) ? so->sol_sbsnd_hiwat :
3025 			    so->so_snd.sb_hiwat;
3026 			goto integer;
3027 
3028 		case SO_RCVBUF:
3029 			optval = SOLISTENING(so) ? so->sol_sbrcv_hiwat :
3030 			    so->so_rcv.sb_hiwat;
3031 			goto integer;
3032 
3033 		case SO_SNDLOWAT:
3034 			optval = SOLISTENING(so) ? so->sol_sbsnd_lowat :
3035 			    so->so_snd.sb_lowat;
3036 			goto integer;
3037 
3038 		case SO_RCVLOWAT:
3039 			optval = SOLISTENING(so) ? so->sol_sbrcv_lowat :
3040 			    so->so_rcv.sb_lowat;
3041 			goto integer;
3042 
3043 		case SO_SNDTIMEO:
3044 		case SO_RCVTIMEO:
3045 			tv = sbttotv(sopt->sopt_name == SO_SNDTIMEO ?
3046 			    so->so_snd.sb_timeo : so->so_rcv.sb_timeo);
3047 #ifdef COMPAT_FREEBSD32
3048 			if (SV_CURPROC_FLAG(SV_ILP32)) {
3049 				struct timeval32 tv32;
3050 
3051 				CP(tv, tv32, tv_sec);
3052 				CP(tv, tv32, tv_usec);
3053 				error = sooptcopyout(sopt, &tv32, sizeof tv32);
3054 			} else
3055 #endif
3056 				error = sooptcopyout(sopt, &tv, sizeof tv);
3057 			break;
3058 
3059 		case SO_LABEL:
3060 #ifdef MAC
3061 			error = sooptcopyin(sopt, &extmac, sizeof(extmac),
3062 			    sizeof(extmac));
3063 			if (error)
3064 				goto bad;
3065 			error = mac_getsockopt_label(sopt->sopt_td->td_ucred,
3066 			    so, &extmac);
3067 			if (error)
3068 				goto bad;
3069 			error = sooptcopyout(sopt, &extmac, sizeof extmac);
3070 #else
3071 			error = EOPNOTSUPP;
3072 #endif
3073 			break;
3074 
3075 		case SO_PEERLABEL:
3076 #ifdef MAC
3077 			error = sooptcopyin(sopt, &extmac, sizeof(extmac),
3078 			    sizeof(extmac));
3079 			if (error)
3080 				goto bad;
3081 			error = mac_getsockopt_peerlabel(
3082 			    sopt->sopt_td->td_ucred, so, &extmac);
3083 			if (error)
3084 				goto bad;
3085 			error = sooptcopyout(sopt, &extmac, sizeof extmac);
3086 #else
3087 			error = EOPNOTSUPP;
3088 #endif
3089 			break;
3090 
3091 		case SO_LISTENQLIMIT:
3092 			optval = SOLISTENING(so) ? so->sol_qlimit : 0;
3093 			goto integer;
3094 
3095 		case SO_LISTENQLEN:
3096 			optval = SOLISTENING(so) ? so->sol_qlen : 0;
3097 			goto integer;
3098 
3099 		case SO_LISTENINCQLEN:
3100 			optval = SOLISTENING(so) ? so->sol_incqlen : 0;
3101 			goto integer;
3102 
3103 		case SO_TS_CLOCK:
3104 			optval = so->so_ts_clock;
3105 			goto integer;
3106 
3107 		case SO_MAX_PACING_RATE:
3108 			optval = so->so_max_pacing_rate;
3109 			goto integer;
3110 
3111 		default:
3112 			if (V_socket_hhh[HHOOK_SOCKET_OPT]->hhh_nhooks > 0)
3113 				error = hhook_run_socket(so, sopt,
3114 				    HHOOK_SOCKET_OPT);
3115 			else
3116 				error = ENOPROTOOPT;
3117 			break;
3118 		}
3119 	}
3120 #ifdef MAC
3121 bad:
3122 #endif
3123 	CURVNET_RESTORE();
3124 	return (error);
3125 }
3126 
3127 int
3128 soopt_getm(struct sockopt *sopt, struct mbuf **mp)
3129 {
3130 	struct mbuf *m, *m_prev;
3131 	int sopt_size = sopt->sopt_valsize;
3132 
3133 	MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
3134 	if (m == NULL)
3135 		return ENOBUFS;
3136 	if (sopt_size > MLEN) {
3137 		MCLGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT);
3138 		if ((m->m_flags & M_EXT) == 0) {
3139 			m_free(m);
3140 			return ENOBUFS;
3141 		}
3142 		m->m_len = min(MCLBYTES, sopt_size);
3143 	} else {
3144 		m->m_len = min(MLEN, sopt_size);
3145 	}
3146 	sopt_size -= m->m_len;
3147 	*mp = m;
3148 	m_prev = m;
3149 
3150 	while (sopt_size) {
3151 		MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
3152 		if (m == NULL) {
3153 			m_freem(*mp);
3154 			return ENOBUFS;
3155 		}
3156 		if (sopt_size > MLEN) {
3157 			MCLGET(m, sopt->sopt_td != NULL ? M_WAITOK :
3158 			    M_NOWAIT);
3159 			if ((m->m_flags & M_EXT) == 0) {
3160 				m_freem(m);
3161 				m_freem(*mp);
3162 				return ENOBUFS;
3163 			}
3164 			m->m_len = min(MCLBYTES, sopt_size);
3165 		} else {
3166 			m->m_len = min(MLEN, sopt_size);
3167 		}
3168 		sopt_size -= m->m_len;
3169 		m_prev->m_next = m;
3170 		m_prev = m;
3171 	}
3172 	return (0);
3173 }
3174 
3175 int
3176 soopt_mcopyin(struct sockopt *sopt, struct mbuf *m)
3177 {
3178 	struct mbuf *m0 = m;
3179 
3180 	if (sopt->sopt_val == NULL)
3181 		return (0);
3182 	while (m != NULL && sopt->sopt_valsize >= m->m_len) {
3183 		if (sopt->sopt_td != NULL) {
3184 			int error;
3185 
3186 			error = copyin(sopt->sopt_val, mtod(m, char *),
3187 			    m->m_len);
3188 			if (error != 0) {
3189 				m_freem(m0);
3190 				return(error);
3191 			}
3192 		} else
3193 			bcopy(sopt->sopt_val, mtod(m, char *), m->m_len);
3194 		sopt->sopt_valsize -= m->m_len;
3195 		sopt->sopt_val = (char *)sopt->sopt_val + m->m_len;
3196 		m = m->m_next;
3197 	}
3198 	if (m != NULL) /* should be allocated enoughly at ip6_sooptmcopyin() */
3199 		panic("ip6_sooptmcopyin");
3200 	return (0);
3201 }
3202 
3203 int
3204 soopt_mcopyout(struct sockopt *sopt, struct mbuf *m)
3205 {
3206 	struct mbuf *m0 = m;
3207 	size_t valsize = 0;
3208 
3209 	if (sopt->sopt_val == NULL)
3210 		return (0);
3211 	while (m != NULL && sopt->sopt_valsize >= m->m_len) {
3212 		if (sopt->sopt_td != NULL) {
3213 			int error;
3214 
3215 			error = copyout(mtod(m, char *), sopt->sopt_val,
3216 			    m->m_len);
3217 			if (error != 0) {
3218 				m_freem(m0);
3219 				return(error);
3220 			}
3221 		} else
3222 			bcopy(mtod(m, char *), sopt->sopt_val, m->m_len);
3223 		sopt->sopt_valsize -= m->m_len;
3224 		sopt->sopt_val = (char *)sopt->sopt_val + m->m_len;
3225 		valsize += m->m_len;
3226 		m = m->m_next;
3227 	}
3228 	if (m != NULL) {
3229 		/* enough soopt buffer should be given from user-land */
3230 		m_freem(m0);
3231 		return(EINVAL);
3232 	}
3233 	sopt->sopt_valsize = valsize;
3234 	return (0);
3235 }
3236 
3237 /*
3238  * sohasoutofband(): protocol notifies socket layer of the arrival of new
3239  * out-of-band data, which will then notify socket consumers.
3240  */
3241 void
3242 sohasoutofband(struct socket *so)
3243 {
3244 
3245 	if (so->so_sigio != NULL)
3246 		pgsigio(&so->so_sigio, SIGURG, 0);
3247 	selwakeuppri(&so->so_rdsel, PSOCK);
3248 }
3249 
3250 int
3251 sopoll(struct socket *so, int events, struct ucred *active_cred,
3252     struct thread *td)
3253 {
3254 
3255 	/*
3256 	 * We do not need to set or assert curvnet as long as everyone uses
3257 	 * sopoll_generic().
3258 	 */
3259 	return (so->so_proto->pr_usrreqs->pru_sopoll(so, events, active_cred,
3260 	    td));
3261 }
3262 
3263 int
3264 sopoll_generic(struct socket *so, int events, struct ucred *active_cred,
3265     struct thread *td)
3266 {
3267 	int revents;
3268 
3269 	SOCK_LOCK(so);
3270 	if (SOLISTENING(so)) {
3271 		if (!(events & (POLLIN | POLLRDNORM)))
3272 			revents = 0;
3273 		else if (!TAILQ_EMPTY(&so->sol_comp))
3274 			revents = events & (POLLIN | POLLRDNORM);
3275 		else {
3276 			selrecord(td, &so->so_rdsel);
3277 			revents = 0;
3278 		}
3279 	} else {
3280 		revents = 0;
3281 		SOCKBUF_LOCK(&so->so_snd);
3282 		SOCKBUF_LOCK(&so->so_rcv);
3283 		if (events & (POLLIN | POLLRDNORM))
3284 			if (soreadabledata(so))
3285 				revents |= events & (POLLIN | POLLRDNORM);
3286 		if (events & (POLLOUT | POLLWRNORM))
3287 			if (sowriteable(so))
3288 				revents |= events & (POLLOUT | POLLWRNORM);
3289 		if (events & (POLLPRI | POLLRDBAND))
3290 			if (so->so_oobmark ||
3291 			    (so->so_rcv.sb_state & SBS_RCVATMARK))
3292 				revents |= events & (POLLPRI | POLLRDBAND);
3293 		if ((events & POLLINIGNEOF) == 0) {
3294 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
3295 				revents |= events & (POLLIN | POLLRDNORM);
3296 				if (so->so_snd.sb_state & SBS_CANTSENDMORE)
3297 					revents |= POLLHUP;
3298 			}
3299 		}
3300 		if (revents == 0) {
3301 			if (events &
3302 			    (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) {
3303 				selrecord(td, &so->so_rdsel);
3304 				so->so_rcv.sb_flags |= SB_SEL;
3305 			}
3306 			if (events & (POLLOUT | POLLWRNORM)) {
3307 				selrecord(td, &so->so_wrsel);
3308 				so->so_snd.sb_flags |= SB_SEL;
3309 			}
3310 		}
3311 		SOCKBUF_UNLOCK(&so->so_rcv);
3312 		SOCKBUF_UNLOCK(&so->so_snd);
3313 	}
3314 	SOCK_UNLOCK(so);
3315 	return (revents);
3316 }
3317 
3318 int
3319 soo_kqfilter(struct file *fp, struct knote *kn)
3320 {
3321 	struct socket *so = kn->kn_fp->f_data;
3322 	struct sockbuf *sb;
3323 	struct knlist *knl;
3324 
3325 	switch (kn->kn_filter) {
3326 	case EVFILT_READ:
3327 		kn->kn_fop = &soread_filtops;
3328 		knl = &so->so_rdsel.si_note;
3329 		sb = &so->so_rcv;
3330 		break;
3331 	case EVFILT_WRITE:
3332 		kn->kn_fop = &sowrite_filtops;
3333 		knl = &so->so_wrsel.si_note;
3334 		sb = &so->so_snd;
3335 		break;
3336 	case EVFILT_EMPTY:
3337 		kn->kn_fop = &soempty_filtops;
3338 		knl = &so->so_wrsel.si_note;
3339 		sb = &so->so_snd;
3340 		break;
3341 	default:
3342 		return (EINVAL);
3343 	}
3344 
3345 	SOCK_LOCK(so);
3346 	if (SOLISTENING(so)) {
3347 		knlist_add(knl, kn, 1);
3348 	} else {
3349 		SOCKBUF_LOCK(sb);
3350 		knlist_add(knl, kn, 1);
3351 		sb->sb_flags |= SB_KNOTE;
3352 		SOCKBUF_UNLOCK(sb);
3353 	}
3354 	SOCK_UNLOCK(so);
3355 	return (0);
3356 }
3357 
3358 /*
3359  * Some routines that return EOPNOTSUPP for entry points that are not
3360  * supported by a protocol.  Fill in as needed.
3361  */
3362 int
3363 pru_accept_notsupp(struct socket *so, struct sockaddr **nam)
3364 {
3365 
3366 	return EOPNOTSUPP;
3367 }
3368 
3369 int
3370 pru_aio_queue_notsupp(struct socket *so, struct kaiocb *job)
3371 {
3372 
3373 	return EOPNOTSUPP;
3374 }
3375 
3376 int
3377 pru_attach_notsupp(struct socket *so, int proto, struct thread *td)
3378 {
3379 
3380 	return EOPNOTSUPP;
3381 }
3382 
3383 int
3384 pru_bind_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
3385 {
3386 
3387 	return EOPNOTSUPP;
3388 }
3389 
3390 int
3391 pru_bindat_notsupp(int fd, struct socket *so, struct sockaddr *nam,
3392     struct thread *td)
3393 {
3394 
3395 	return EOPNOTSUPP;
3396 }
3397 
3398 int
3399 pru_connect_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
3400 {
3401 
3402 	return EOPNOTSUPP;
3403 }
3404 
3405 int
3406 pru_connectat_notsupp(int fd, struct socket *so, struct sockaddr *nam,
3407     struct thread *td)
3408 {
3409 
3410 	return EOPNOTSUPP;
3411 }
3412 
3413 int
3414 pru_connect2_notsupp(struct socket *so1, struct socket *so2)
3415 {
3416 
3417 	return EOPNOTSUPP;
3418 }
3419 
3420 int
3421 pru_control_notsupp(struct socket *so, u_long cmd, caddr_t data,
3422     struct ifnet *ifp, struct thread *td)
3423 {
3424 
3425 	return EOPNOTSUPP;
3426 }
3427 
3428 int
3429 pru_disconnect_notsupp(struct socket *so)
3430 {
3431 
3432 	return EOPNOTSUPP;
3433 }
3434 
3435 int
3436 pru_listen_notsupp(struct socket *so, int backlog, struct thread *td)
3437 {
3438 
3439 	return EOPNOTSUPP;
3440 }
3441 
3442 int
3443 pru_peeraddr_notsupp(struct socket *so, struct sockaddr **nam)
3444 {
3445 
3446 	return EOPNOTSUPP;
3447 }
3448 
3449 int
3450 pru_rcvd_notsupp(struct socket *so, int flags)
3451 {
3452 
3453 	return EOPNOTSUPP;
3454 }
3455 
3456 int
3457 pru_rcvoob_notsupp(struct socket *so, struct mbuf *m, int flags)
3458 {
3459 
3460 	return EOPNOTSUPP;
3461 }
3462 
3463 int
3464 pru_send_notsupp(struct socket *so, int flags, struct mbuf *m,
3465     struct sockaddr *addr, struct mbuf *control, struct thread *td)
3466 {
3467 
3468 	return EOPNOTSUPP;
3469 }
3470 
3471 int
3472 pru_ready_notsupp(struct socket *so, struct mbuf *m, int count)
3473 {
3474 
3475 	return (EOPNOTSUPP);
3476 }
3477 
3478 /*
3479  * This isn't really a ``null'' operation, but it's the default one and
3480  * doesn't do anything destructive.
3481  */
3482 int
3483 pru_sense_null(struct socket *so, struct stat *sb)
3484 {
3485 
3486 	sb->st_blksize = so->so_snd.sb_hiwat;
3487 	return 0;
3488 }
3489 
3490 int
3491 pru_shutdown_notsupp(struct socket *so)
3492 {
3493 
3494 	return EOPNOTSUPP;
3495 }
3496 
3497 int
3498 pru_sockaddr_notsupp(struct socket *so, struct sockaddr **nam)
3499 {
3500 
3501 	return EOPNOTSUPP;
3502 }
3503 
3504 int
3505 pru_sosend_notsupp(struct socket *so, struct sockaddr *addr, struct uio *uio,
3506     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
3507 {
3508 
3509 	return EOPNOTSUPP;
3510 }
3511 
3512 int
3513 pru_soreceive_notsupp(struct socket *so, struct sockaddr **paddr,
3514     struct uio *uio, struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
3515 {
3516 
3517 	return EOPNOTSUPP;
3518 }
3519 
3520 int
3521 pru_sopoll_notsupp(struct socket *so, int events, struct ucred *cred,
3522     struct thread *td)
3523 {
3524 
3525 	return EOPNOTSUPP;
3526 }
3527 
3528 static void
3529 filt_sordetach(struct knote *kn)
3530 {
3531 	struct socket *so = kn->kn_fp->f_data;
3532 
3533 	so_rdknl_lock(so);
3534 	knlist_remove(&so->so_rdsel.si_note, kn, 1);
3535 	if (!SOLISTENING(so) && knlist_empty(&so->so_rdsel.si_note))
3536 		so->so_rcv.sb_flags &= ~SB_KNOTE;
3537 	so_rdknl_unlock(so);
3538 }
3539 
3540 /*ARGSUSED*/
3541 static int
3542 filt_soread(struct knote *kn, long hint)
3543 {
3544 	struct socket *so;
3545 
3546 	so = kn->kn_fp->f_data;
3547 
3548 	if (SOLISTENING(so)) {
3549 		SOCK_LOCK_ASSERT(so);
3550 		kn->kn_data = so->sol_qlen;
3551 		return (!TAILQ_EMPTY(&so->sol_comp));
3552 	}
3553 
3554 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
3555 
3556 	kn->kn_data = sbavail(&so->so_rcv) - so->so_rcv.sb_ctl;
3557 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
3558 		kn->kn_flags |= EV_EOF;
3559 		kn->kn_fflags = so->so_error;
3560 		return (1);
3561 	} else if (so->so_error)	/* temporary udp error */
3562 		return (1);
3563 
3564 	if (kn->kn_sfflags & NOTE_LOWAT) {
3565 		if (kn->kn_data >= kn->kn_sdata)
3566 			return (1);
3567 	} else if (sbavail(&so->so_rcv) >= so->so_rcv.sb_lowat)
3568 		return (1);
3569 
3570 	/* This hook returning non-zero indicates an event, not error */
3571 	return (hhook_run_socket(so, NULL, HHOOK_FILT_SOREAD));
3572 }
3573 
3574 static void
3575 filt_sowdetach(struct knote *kn)
3576 {
3577 	struct socket *so = kn->kn_fp->f_data;
3578 
3579 	so_wrknl_lock(so);
3580 	knlist_remove(&so->so_wrsel.si_note, kn, 1);
3581 	if (!SOLISTENING(so) && knlist_empty(&so->so_wrsel.si_note))
3582 		so->so_snd.sb_flags &= ~SB_KNOTE;
3583 	so_wrknl_unlock(so);
3584 }
3585 
3586 /*ARGSUSED*/
3587 static int
3588 filt_sowrite(struct knote *kn, long hint)
3589 {
3590 	struct socket *so;
3591 
3592 	so = kn->kn_fp->f_data;
3593 
3594 	if (SOLISTENING(so))
3595 		return (0);
3596 
3597 	SOCKBUF_LOCK_ASSERT(&so->so_snd);
3598 	kn->kn_data = sbspace(&so->so_snd);
3599 
3600 	hhook_run_socket(so, kn, HHOOK_FILT_SOWRITE);
3601 
3602 	if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
3603 		kn->kn_flags |= EV_EOF;
3604 		kn->kn_fflags = so->so_error;
3605 		return (1);
3606 	} else if (so->so_error)	/* temporary udp error */
3607 		return (1);
3608 	else if (((so->so_state & SS_ISCONNECTED) == 0) &&
3609 	    (so->so_proto->pr_flags & PR_CONNREQUIRED))
3610 		return (0);
3611 	else if (kn->kn_sfflags & NOTE_LOWAT)
3612 		return (kn->kn_data >= kn->kn_sdata);
3613 	else
3614 		return (kn->kn_data >= so->so_snd.sb_lowat);
3615 }
3616 
3617 static int
3618 filt_soempty(struct knote *kn, long hint)
3619 {
3620 	struct socket *so;
3621 
3622 	so = kn->kn_fp->f_data;
3623 
3624 	if (SOLISTENING(so))
3625 		return (1);
3626 
3627 	SOCKBUF_LOCK_ASSERT(&so->so_snd);
3628 	kn->kn_data = sbused(&so->so_snd);
3629 
3630 	if (kn->kn_data == 0)
3631 		return (1);
3632 	else
3633 		return (0);
3634 }
3635 
3636 int
3637 socheckuid(struct socket *so, uid_t uid)
3638 {
3639 
3640 	if (so == NULL)
3641 		return (EPERM);
3642 	if (so->so_cred->cr_uid != uid)
3643 		return (EPERM);
3644 	return (0);
3645 }
3646 
3647 /*
3648  * These functions are used by protocols to notify the socket layer (and its
3649  * consumers) of state changes in the sockets driven by protocol-side events.
3650  */
3651 
3652 /*
3653  * Procedures to manipulate state flags of socket and do appropriate wakeups.
3654  *
3655  * Normal sequence from the active (originating) side is that
3656  * soisconnecting() is called during processing of connect() call, resulting
3657  * in an eventual call to soisconnected() if/when the connection is
3658  * established.  When the connection is torn down soisdisconnecting() is
3659  * called during processing of disconnect() call, and soisdisconnected() is
3660  * called when the connection to the peer is totally severed.  The semantics
3661  * of these routines are such that connectionless protocols can call
3662  * soisconnected() and soisdisconnected() only, bypassing the in-progress
3663  * calls when setting up a ``connection'' takes no time.
3664  *
3665  * From the passive side, a socket is created with two queues of sockets:
3666  * so_incomp for connections in progress and so_comp for connections already
3667  * made and awaiting user acceptance.  As a protocol is preparing incoming
3668  * connections, it creates a socket structure queued on so_incomp by calling
3669  * sonewconn().  When the connection is established, soisconnected() is
3670  * called, and transfers the socket structure to so_comp, making it available
3671  * to accept().
3672  *
3673  * If a socket is closed with sockets on either so_incomp or so_comp, these
3674  * sockets are dropped.
3675  *
3676  * If higher-level protocols are implemented in the kernel, the wakeups done
3677  * here will sometimes cause software-interrupt process scheduling.
3678  */
3679 void
3680 soisconnecting(struct socket *so)
3681 {
3682 
3683 	SOCK_LOCK(so);
3684 	so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
3685 	so->so_state |= SS_ISCONNECTING;
3686 	SOCK_UNLOCK(so);
3687 }
3688 
3689 void
3690 soisconnected(struct socket *so)
3691 {
3692 
3693 	SOCK_LOCK(so);
3694 	so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING);
3695 	so->so_state |= SS_ISCONNECTED;
3696 
3697 	if (so->so_qstate == SQ_INCOMP) {
3698 		struct socket *head = so->so_listen;
3699 		int ret;
3700 
3701 		KASSERT(head, ("%s: so %p on incomp of NULL", __func__, so));
3702 		/*
3703 		 * Promoting a socket from incomplete queue to complete, we
3704 		 * need to go through reverse order of locking.  We first do
3705 		 * trylock, and if that doesn't succeed, we go the hard way
3706 		 * leaving a reference and rechecking consistency after proper
3707 		 * locking.
3708 		 */
3709 		if (__predict_false(SOLISTEN_TRYLOCK(head) == 0)) {
3710 			soref(head);
3711 			SOCK_UNLOCK(so);
3712 			SOLISTEN_LOCK(head);
3713 			SOCK_LOCK(so);
3714 			if (__predict_false(head != so->so_listen)) {
3715 				/*
3716 				 * The socket went off the listen queue,
3717 				 * should be lost race to close(2) of sol.
3718 				 * The socket is about to soabort().
3719 				 */
3720 				SOCK_UNLOCK(so);
3721 				sorele(head);
3722 				return;
3723 			}
3724 			/* Not the last one, as so holds a ref. */
3725 			refcount_release(&head->so_count);
3726 		}
3727 again:
3728 		if ((so->so_options & SO_ACCEPTFILTER) == 0) {
3729 			TAILQ_REMOVE(&head->sol_incomp, so, so_list);
3730 			head->sol_incqlen--;
3731 			TAILQ_INSERT_TAIL(&head->sol_comp, so, so_list);
3732 			head->sol_qlen++;
3733 			so->so_qstate = SQ_COMP;
3734 			SOCK_UNLOCK(so);
3735 			solisten_wakeup(head);	/* unlocks */
3736 		} else {
3737 			SOCKBUF_LOCK(&so->so_rcv);
3738 			soupcall_set(so, SO_RCV,
3739 			    head->sol_accept_filter->accf_callback,
3740 			    head->sol_accept_filter_arg);
3741 			so->so_options &= ~SO_ACCEPTFILTER;
3742 			ret = head->sol_accept_filter->accf_callback(so,
3743 			    head->sol_accept_filter_arg, M_NOWAIT);
3744 			if (ret == SU_ISCONNECTED) {
3745 				soupcall_clear(so, SO_RCV);
3746 				SOCKBUF_UNLOCK(&so->so_rcv);
3747 				goto again;
3748 			}
3749 			SOCKBUF_UNLOCK(&so->so_rcv);
3750 			SOCK_UNLOCK(so);
3751 			SOLISTEN_UNLOCK(head);
3752 		}
3753 		return;
3754 	}
3755 	SOCK_UNLOCK(so);
3756 	wakeup(&so->so_timeo);
3757 	sorwakeup(so);
3758 	sowwakeup(so);
3759 }
3760 
3761 void
3762 soisdisconnecting(struct socket *so)
3763 {
3764 
3765 	SOCK_LOCK(so);
3766 	so->so_state &= ~SS_ISCONNECTING;
3767 	so->so_state |= SS_ISDISCONNECTING;
3768 
3769 	if (!SOLISTENING(so)) {
3770 		SOCKBUF_LOCK(&so->so_rcv);
3771 		socantrcvmore_locked(so);
3772 		SOCKBUF_LOCK(&so->so_snd);
3773 		socantsendmore_locked(so);
3774 	}
3775 	SOCK_UNLOCK(so);
3776 	wakeup(&so->so_timeo);
3777 }
3778 
3779 void
3780 soisdisconnected(struct socket *so)
3781 {
3782 
3783 	SOCK_LOCK(so);
3784 	so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
3785 	so->so_state |= SS_ISDISCONNECTED;
3786 
3787 	if (!SOLISTENING(so)) {
3788 		SOCK_UNLOCK(so);
3789 		SOCKBUF_LOCK(&so->so_rcv);
3790 		socantrcvmore_locked(so);
3791 		SOCKBUF_LOCK(&so->so_snd);
3792 		sbdrop_locked(&so->so_snd, sbused(&so->so_snd));
3793 		socantsendmore_locked(so);
3794 	} else
3795 		SOCK_UNLOCK(so);
3796 	wakeup(&so->so_timeo);
3797 }
3798 
3799 /*
3800  * Make a copy of a sockaddr in a malloced buffer of type M_SONAME.
3801  */
3802 struct sockaddr *
3803 sodupsockaddr(const struct sockaddr *sa, int mflags)
3804 {
3805 	struct sockaddr *sa2;
3806 
3807 	sa2 = malloc(sa->sa_len, M_SONAME, mflags);
3808 	if (sa2)
3809 		bcopy(sa, sa2, sa->sa_len);
3810 	return sa2;
3811 }
3812 
3813 /*
3814  * Register per-socket buffer upcalls.
3815  */
3816 void
3817 soupcall_set(struct socket *so, int which, so_upcall_t func, void *arg)
3818 {
3819 	struct sockbuf *sb;
3820 
3821 	KASSERT(!SOLISTENING(so), ("%s: so %p listening", __func__, so));
3822 
3823 	switch (which) {
3824 	case SO_RCV:
3825 		sb = &so->so_rcv;
3826 		break;
3827 	case SO_SND:
3828 		sb = &so->so_snd;
3829 		break;
3830 	default:
3831 		panic("soupcall_set: bad which");
3832 	}
3833 	SOCKBUF_LOCK_ASSERT(sb);
3834 	sb->sb_upcall = func;
3835 	sb->sb_upcallarg = arg;
3836 	sb->sb_flags |= SB_UPCALL;
3837 }
3838 
3839 void
3840 soupcall_clear(struct socket *so, int which)
3841 {
3842 	struct sockbuf *sb;
3843 
3844 	KASSERT(!SOLISTENING(so), ("%s: so %p listening", __func__, so));
3845 
3846 	switch (which) {
3847 	case SO_RCV:
3848 		sb = &so->so_rcv;
3849 		break;
3850 	case SO_SND:
3851 		sb = &so->so_snd;
3852 		break;
3853 	default:
3854 		panic("soupcall_clear: bad which");
3855 	}
3856 	SOCKBUF_LOCK_ASSERT(sb);
3857 	KASSERT(sb->sb_upcall != NULL,
3858 	    ("%s: so %p no upcall to clear", __func__, so));
3859 	sb->sb_upcall = NULL;
3860 	sb->sb_upcallarg = NULL;
3861 	sb->sb_flags &= ~SB_UPCALL;
3862 }
3863 
3864 void
3865 solisten_upcall_set(struct socket *so, so_upcall_t func, void *arg)
3866 {
3867 
3868 	SOLISTEN_LOCK_ASSERT(so);
3869 	so->sol_upcall = func;
3870 	so->sol_upcallarg = arg;
3871 }
3872 
3873 static void
3874 so_rdknl_lock(void *arg)
3875 {
3876 	struct socket *so = arg;
3877 
3878 	if (SOLISTENING(so))
3879 		SOCK_LOCK(so);
3880 	else
3881 		SOCKBUF_LOCK(&so->so_rcv);
3882 }
3883 
3884 static void
3885 so_rdknl_unlock(void *arg)
3886 {
3887 	struct socket *so = arg;
3888 
3889 	if (SOLISTENING(so))
3890 		SOCK_UNLOCK(so);
3891 	else
3892 		SOCKBUF_UNLOCK(&so->so_rcv);
3893 }
3894 
3895 static void
3896 so_rdknl_assert_locked(void *arg)
3897 {
3898 	struct socket *so = arg;
3899 
3900 	if (SOLISTENING(so))
3901 		SOCK_LOCK_ASSERT(so);
3902 	else
3903 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
3904 }
3905 
3906 static void
3907 so_rdknl_assert_unlocked(void *arg)
3908 {
3909 	struct socket *so = arg;
3910 
3911 	if (SOLISTENING(so))
3912 		SOCK_UNLOCK_ASSERT(so);
3913 	else
3914 		SOCKBUF_UNLOCK_ASSERT(&so->so_rcv);
3915 }
3916 
3917 static void
3918 so_wrknl_lock(void *arg)
3919 {
3920 	struct socket *so = arg;
3921 
3922 	if (SOLISTENING(so))
3923 		SOCK_LOCK(so);
3924 	else
3925 		SOCKBUF_LOCK(&so->so_snd);
3926 }
3927 
3928 static void
3929 so_wrknl_unlock(void *arg)
3930 {
3931 	struct socket *so = arg;
3932 
3933 	if (SOLISTENING(so))
3934 		SOCK_UNLOCK(so);
3935 	else
3936 		SOCKBUF_UNLOCK(&so->so_snd);
3937 }
3938 
3939 static void
3940 so_wrknl_assert_locked(void *arg)
3941 {
3942 	struct socket *so = arg;
3943 
3944 	if (SOLISTENING(so))
3945 		SOCK_LOCK_ASSERT(so);
3946 	else
3947 		SOCKBUF_LOCK_ASSERT(&so->so_snd);
3948 }
3949 
3950 static void
3951 so_wrknl_assert_unlocked(void *arg)
3952 {
3953 	struct socket *so = arg;
3954 
3955 	if (SOLISTENING(so))
3956 		SOCK_UNLOCK_ASSERT(so);
3957 	else
3958 		SOCKBUF_UNLOCK_ASSERT(&so->so_snd);
3959 }
3960 
3961 /*
3962  * Create an external-format (``xsocket'') structure using the information in
3963  * the kernel-format socket structure pointed to by so.  This is done to
3964  * reduce the spew of irrelevant information over this interface, to isolate
3965  * user code from changes in the kernel structure, and potentially to provide
3966  * information-hiding if we decide that some of this information should be
3967  * hidden from users.
3968  */
3969 void
3970 sotoxsocket(struct socket *so, struct xsocket *xso)
3971 {
3972 
3973 	xso->xso_len = sizeof *xso;
3974 	xso->xso_so = so;
3975 	xso->so_type = so->so_type;
3976 	xso->so_options = so->so_options;
3977 	xso->so_linger = so->so_linger;
3978 	xso->so_state = so->so_state;
3979 	xso->so_pcb = so->so_pcb;
3980 	xso->xso_protocol = so->so_proto->pr_protocol;
3981 	xso->xso_family = so->so_proto->pr_domain->dom_family;
3982 	xso->so_timeo = so->so_timeo;
3983 	xso->so_error = so->so_error;
3984 	xso->so_uid = so->so_cred->cr_uid;
3985 	xso->so_pgid = so->so_sigio ? so->so_sigio->sio_pgid : 0;
3986 	if (SOLISTENING(so)) {
3987 		xso->so_qlen = so->sol_qlen;
3988 		xso->so_incqlen = so->sol_incqlen;
3989 		xso->so_qlimit = so->sol_qlimit;
3990 		xso->so_oobmark = 0;
3991 		bzero(&xso->so_snd, sizeof(xso->so_snd));
3992 		bzero(&xso->so_rcv, sizeof(xso->so_rcv));
3993 	} else {
3994 		xso->so_state |= so->so_qstate;
3995 		xso->so_qlen = xso->so_incqlen = xso->so_qlimit = 0;
3996 		xso->so_oobmark = so->so_oobmark;
3997 		sbtoxsockbuf(&so->so_snd, &xso->so_snd);
3998 		sbtoxsockbuf(&so->so_rcv, &xso->so_rcv);
3999 	}
4000 }
4001 
4002 struct sockbuf *
4003 so_sockbuf_rcv(struct socket *so)
4004 {
4005 
4006 	return (&so->so_rcv);
4007 }
4008 
4009 struct sockbuf *
4010 so_sockbuf_snd(struct socket *so)
4011 {
4012 
4013 	return (&so->so_snd);
4014 }
4015 
4016 int
4017 so_state_get(const struct socket *so)
4018 {
4019 
4020 	return (so->so_state);
4021 }
4022 
4023 void
4024 so_state_set(struct socket *so, int val)
4025 {
4026 
4027 	so->so_state = val;
4028 }
4029 
4030 int
4031 so_options_get(const struct socket *so)
4032 {
4033 
4034 	return (so->so_options);
4035 }
4036 
4037 void
4038 so_options_set(struct socket *so, int val)
4039 {
4040 
4041 	so->so_options = val;
4042 }
4043 
4044 int
4045 so_error_get(const struct socket *so)
4046 {
4047 
4048 	return (so->so_error);
4049 }
4050 
4051 void
4052 so_error_set(struct socket *so, int val)
4053 {
4054 
4055 	so->so_error = val;
4056 }
4057 
4058 int
4059 so_linger_get(const struct socket *so)
4060 {
4061 
4062 	return (so->so_linger);
4063 }
4064 
4065 void
4066 so_linger_set(struct socket *so, int val)
4067 {
4068 
4069 	so->so_linger = val;
4070 }
4071 
4072 struct protosw *
4073 so_protosw_get(const struct socket *so)
4074 {
4075 
4076 	return (so->so_proto);
4077 }
4078 
4079 void
4080 so_protosw_set(struct socket *so, struct protosw *val)
4081 {
4082 
4083 	so->so_proto = val;
4084 }
4085 
4086 void
4087 so_sorwakeup(struct socket *so)
4088 {
4089 
4090 	sorwakeup(so);
4091 }
4092 
4093 void
4094 so_sowwakeup(struct socket *so)
4095 {
4096 
4097 	sowwakeup(so);
4098 }
4099 
4100 void
4101 so_sorwakeup_locked(struct socket *so)
4102 {
4103 
4104 	sorwakeup_locked(so);
4105 }
4106 
4107 void
4108 so_sowwakeup_locked(struct socket *so)
4109 {
4110 
4111 	sowwakeup_locked(so);
4112 }
4113 
4114 void
4115 so_lock(struct socket *so)
4116 {
4117 
4118 	SOCK_LOCK(so);
4119 }
4120 
4121 void
4122 so_unlock(struct socket *so)
4123 {
4124 
4125 	SOCK_UNLOCK(so);
4126 }
4127