xref: /freebsd/sys/kern/uipc_socket.c (revision 95eb4b873b6a8b527c5bd78d7191975dfca38998)
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 
35 /*
36  * Comments on the socket life cycle:
37  *
38  * soalloc() sets of socket layer state for a socket, called only by
39  * socreate() and sonewconn().  Socket layer private.
40  *
41  * sodealloc() tears down socket layer state for a socket, called only by
42  * sofree() and sonewconn().  Socket layer private.
43  *
44  * pru_attach() associates protocol layer state with an allocated socket;
45  * called only once, may fail, aborting socket allocation.  This is called
46  * from socreate() and sonewconn().  Socket layer private.
47  *
48  * pru_detach() disassociates protocol layer state from an attached socket,
49  * and will be called exactly once for sockets in which pru_attach() has
50  * been successfully called.  If pru_attach() returned an error,
51  * pru_detach() will not be called.  Socket layer private.
52  *
53  * pru_abort() and pru_close() notify the protocol layer that the last
54  * consumer of a socket is starting to tear down the socket, and that the
55  * protocol should terminate the connection.  Historically, pru_abort() also
56  * detached protocol state from the socket state, but this is no longer the
57  * case.
58  *
59  * socreate() creates a socket and attaches protocol state.  This is a public
60  * interface that may be used by socket layer consumers to create new
61  * sockets.
62  *
63  * sonewconn() creates a socket and attaches protocol state.  This is a
64  * public interface  that may be used by protocols to create new sockets when
65  * a new connection is received and will be available for accept() on a
66  * listen socket.
67  *
68  * soclose() destroys a socket after possibly waiting for it to disconnect.
69  * This is a public interface that socket consumers should use to close and
70  * release a socket when done with it.
71  *
72  * soabort() destroys a socket without waiting for it to disconnect (used
73  * only for incoming connections that are already partially or fully
74  * connected).  This is used internally by the socket layer when clearing
75  * listen socket queues (due to overflow or close on the listen socket), but
76  * is also a public interface protocols may use to abort connections in
77  * their incomplete listen queues should they no longer be required.  Sockets
78  * placed in completed connection listen queues should not be aborted for
79  * reasons described in the comment above the soclose() implementation.  This
80  * is not a general purpose close routine, and except in the specific
81  * circumstances described here, should not be used.
82  *
83  * sofree() will free a socket and its protocol state if all references on
84  * the socket have been released, and is the public interface to attempt to
85  * free a socket when a reference is removed.  This is a socket layer private
86  * interface.
87  *
88  * NOTE: In addition to socreate() and soclose(), which provide a single
89  * socket reference to the consumer to be managed as required, there are two
90  * calls to explicitly manage socket references, soref(), and sorele().
91  * Currently, these are generally required only when transitioning a socket
92  * from a listen queue to a file descriptor, in order to prevent garbage
93  * collection of the socket at an untimely moment.  For a number of reasons,
94  * these interfaces are not preferred, and should be avoided.
95  *
96  * NOTE: With regard to VNETs the general rule is that callers do not set
97  * curvnet. Exceptions to this rule include soabort(), sodisconnect(),
98  * sofree(), sorele(), sonewconn() and sorflush(), which are usually called
99  * from a pre-set VNET context.  sopoll() currently does not need a VNET
100  * context to be set.
101  */
102 
103 #include <sys/cdefs.h>
104 #include "opt_inet.h"
105 #include "opt_inet6.h"
106 #include "opt_kern_tls.h"
107 #include "opt_ktrace.h"
108 #include "opt_sctp.h"
109 
110 #include <sys/param.h>
111 #include <sys/systm.h>
112 #include <sys/capsicum.h>
113 #include <sys/fcntl.h>
114 #include <sys/limits.h>
115 #include <sys/lock.h>
116 #include <sys/mac.h>
117 #include <sys/malloc.h>
118 #include <sys/mbuf.h>
119 #include <sys/mutex.h>
120 #include <sys/domain.h>
121 #include <sys/file.h>			/* for struct knote */
122 #include <sys/hhook.h>
123 #include <sys/kernel.h>
124 #include <sys/khelp.h>
125 #include <sys/ktls.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/sbuf.h>
132 #include <sys/socket.h>
133 #include <sys/socketvar.h>
134 #include <sys/resourcevar.h>
135 #include <net/route.h>
136 #include <sys/signalvar.h>
137 #include <sys/stat.h>
138 #include <sys/sx.h>
139 #include <sys/sysctl.h>
140 #include <sys/taskqueue.h>
141 #include <sys/uio.h>
142 #include <sys/un.h>
143 #include <sys/unpcb.h>
144 #include <sys/jail.h>
145 #include <sys/syslog.h>
146 #include <netinet/in.h>
147 #include <netinet/in_pcb.h>
148 #include <netinet/tcp.h>
149 
150 #include <net/vnet.h>
151 
152 #include <security/mac/mac_framework.h>
153 
154 #include <vm/uma.h>
155 
156 #ifdef COMPAT_FREEBSD32
157 #include <sys/mount.h>
158 #include <sys/sysent.h>
159 #include <compat/freebsd32/freebsd32.h>
160 #endif
161 
162 static int	soreceive_rcvoob(struct socket *so, struct uio *uio,
163 		    int flags);
164 static void	so_rdknl_lock(void *);
165 static void	so_rdknl_unlock(void *);
166 static void	so_rdknl_assert_lock(void *, int);
167 static void	so_wrknl_lock(void *);
168 static void	so_wrknl_unlock(void *);
169 static void	so_wrknl_assert_lock(void *, int);
170 
171 static void	filt_sordetach(struct knote *kn);
172 static int	filt_soread(struct knote *kn, long hint);
173 static void	filt_sowdetach(struct knote *kn);
174 static int	filt_sowrite(struct knote *kn, long hint);
175 static int	filt_soempty(struct knote *kn, long hint);
176 fo_kqfilter_t	soo_kqfilter;
177 
178 static struct filterops soread_filtops = {
179 	.f_isfd = 1,
180 	.f_detach = filt_sordetach,
181 	.f_event = filt_soread,
182 };
183 static struct filterops sowrite_filtops = {
184 	.f_isfd = 1,
185 	.f_detach = filt_sowdetach,
186 	.f_event = filt_sowrite,
187 };
188 static struct filterops soempty_filtops = {
189 	.f_isfd = 1,
190 	.f_detach = filt_sowdetach,
191 	.f_event = filt_soempty,
192 };
193 
194 so_gen_t	so_gencnt;	/* generation count for sockets */
195 
196 MALLOC_DEFINE(M_SONAME, "soname", "socket name");
197 MALLOC_DEFINE(M_PCB, "pcb", "protocol control block");
198 
199 #define	VNET_SO_ASSERT(so)						\
200 	VNET_ASSERT(curvnet != NULL,					\
201 	    ("%s:%d curvnet is NULL, so=%p", __func__, __LINE__, (so)));
202 
203 #ifdef SOCKET_HHOOK
204 VNET_DEFINE(struct hhook_head *, socket_hhh[HHOOK_SOCKET_LAST + 1]);
205 #define	V_socket_hhh		VNET(socket_hhh)
206 static inline int hhook_run_socket(struct socket *, void *, int32_t);
207 #endif
208 
209 /*
210  * Limit on the number of connections in the listen queue waiting
211  * for accept(2).
212  * NB: The original sysctl somaxconn is still available but hidden
213  * to prevent confusion about the actual purpose of this number.
214  */
215 static u_int somaxconn = SOMAXCONN;
216 
217 static int
218 sysctl_somaxconn(SYSCTL_HANDLER_ARGS)
219 {
220 	int error;
221 	int val;
222 
223 	val = somaxconn;
224 	error = sysctl_handle_int(oidp, &val, 0, req);
225 	if (error || !req->newptr )
226 		return (error);
227 
228 	/*
229 	 * The purpose of the UINT_MAX / 3 limit, is so that the formula
230 	 *   3 * so_qlimit / 2
231 	 * below, will not overflow.
232          */
233 
234 	if (val < 1 || val > UINT_MAX / 3)
235 		return (EINVAL);
236 
237 	somaxconn = val;
238 	return (0);
239 }
240 SYSCTL_PROC(_kern_ipc, OID_AUTO, soacceptqueue,
241     CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, sizeof(int),
242     sysctl_somaxconn, "I",
243     "Maximum listen socket pending connection accept queue size");
244 SYSCTL_PROC(_kern_ipc, KIPC_SOMAXCONN, somaxconn,
245     CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_SKIP | CTLFLAG_MPSAFE, 0,
246     sizeof(int), sysctl_somaxconn, "I",
247     "Maximum listen socket pending connection accept queue size (compat)");
248 
249 static int numopensockets;
250 SYSCTL_INT(_kern_ipc, OID_AUTO, numopensockets, CTLFLAG_RD,
251     &numopensockets, 0, "Number of open sockets");
252 
253 /*
254  * so_global_mtx protects so_gencnt, numopensockets, and the per-socket
255  * so_gencnt field.
256  */
257 static struct mtx so_global_mtx;
258 MTX_SYSINIT(so_global_mtx, &so_global_mtx, "so_glabel", MTX_DEF);
259 
260 /*
261  * General IPC sysctl name space, used by sockets and a variety of other IPC
262  * types.
263  */
264 SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
265     "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_init(void *tag)
283 {
284 
285 	socket_zone = uma_zcreate("socket", sizeof(struct socket), NULL, NULL,
286 	    NULL, NULL, UMA_ALIGN_PTR, 0);
287 	maxsockets = uma_zone_set_max(socket_zone, maxsockets);
288 	uma_zone_set_warning(socket_zone, "kern.ipc.maxsockets limit reached");
289 	EVENTHANDLER_REGISTER(maxsockets_change, socket_zone_change, NULL,
290 	    EVENTHANDLER_PRI_FIRST);
291 }
292 SYSINIT(socket, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY, socket_init, NULL);
293 
294 #ifdef SOCKET_HHOOK
295 static void
296 socket_hhook_register(int subtype)
297 {
298 
299 	if (hhook_head_register(HHOOK_TYPE_SOCKET, subtype,
300 	    &V_socket_hhh[subtype],
301 	    HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
302 		printf("%s: WARNING: unable to register hook\n", __func__);
303 }
304 
305 static void
306 socket_hhook_deregister(int subtype)
307 {
308 
309 	if (hhook_head_deregister(V_socket_hhh[subtype]) != 0)
310 		printf("%s: WARNING: unable to deregister hook\n", __func__);
311 }
312 
313 static void
314 socket_vnet_init(const void *unused __unused)
315 {
316 	int i;
317 
318 	/* We expect a contiguous range */
319 	for (i = 0; i <= HHOOK_SOCKET_LAST; i++)
320 		socket_hhook_register(i);
321 }
322 VNET_SYSINIT(socket_vnet_init, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY,
323     socket_vnet_init, NULL);
324 
325 static void
326 socket_vnet_uninit(const void *unused __unused)
327 {
328 	int i;
329 
330 	for (i = 0; i <= HHOOK_SOCKET_LAST; i++)
331 		socket_hhook_deregister(i);
332 }
333 VNET_SYSUNINIT(socket_vnet_uninit, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY,
334     socket_vnet_uninit, NULL);
335 #endif	/* SOCKET_HHOOK */
336 
337 /*
338  * Initialise maxsockets.  This SYSINIT must be run after
339  * tunable_mbinit().
340  */
341 static void
342 init_maxsockets(void *ignored)
343 {
344 
345 	TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets);
346 	maxsockets = imax(maxsockets, maxfiles);
347 }
348 SYSINIT(param, SI_SUB_TUNABLES, SI_ORDER_ANY, init_maxsockets, NULL);
349 
350 /*
351  * Sysctl to get and set the maximum global sockets limit.  Notify protocols
352  * of the change so that they can update their dependent limits as required.
353  */
354 static int
355 sysctl_maxsockets(SYSCTL_HANDLER_ARGS)
356 {
357 	int error, newmaxsockets;
358 
359 	newmaxsockets = maxsockets;
360 	error = sysctl_handle_int(oidp, &newmaxsockets, 0, req);
361 	if (error == 0 && req->newptr && newmaxsockets != maxsockets) {
362 		if (newmaxsockets > maxsockets &&
363 		    newmaxsockets <= maxfiles) {
364 			maxsockets = newmaxsockets;
365 			EVENTHANDLER_INVOKE(maxsockets_change);
366 		} else
367 			error = EINVAL;
368 	}
369 	return (error);
370 }
371 SYSCTL_PROC(_kern_ipc, OID_AUTO, maxsockets,
372     CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE,
373     &maxsockets, 0, sysctl_maxsockets, "IU",
374     "Maximum number of sockets available");
375 
376 /*
377  * Socket operation routines.  These routines are called by the routines in
378  * sys_socket.c or from a system process, and implement the semantics of
379  * socket operations by switching out to the protocol specific routines.
380  */
381 
382 /*
383  * Get a socket structure from our zone, and initialize it.  Note that it
384  * would probably be better to allocate socket and PCB at the same time, but
385  * I'm not convinced that all the protocols can be easily modified to do
386  * this.
387  *
388  * soalloc() returns a socket with a ref count of 0.
389  */
390 static struct socket *
391 soalloc(struct vnet *vnet)
392 {
393 	struct socket *so;
394 
395 	so = uma_zalloc(socket_zone, M_NOWAIT | M_ZERO);
396 	if (so == NULL)
397 		return (NULL);
398 #ifdef MAC
399 	if (mac_socket_init(so, M_NOWAIT) != 0) {
400 		uma_zfree(socket_zone, so);
401 		return (NULL);
402 	}
403 #endif
404 	if (khelp_init_osd(HELPER_CLASS_SOCKET, &so->osd)) {
405 		uma_zfree(socket_zone, so);
406 		return (NULL);
407 	}
408 
409 	/*
410 	 * The socket locking protocol allows to lock 2 sockets at a time,
411 	 * however, the first one must be a listening socket.  WITNESS lacks
412 	 * a feature to change class of an existing lock, so we use DUPOK.
413 	 */
414 	mtx_init(&so->so_lock, "socket", NULL, MTX_DEF | MTX_DUPOK);
415 	mtx_init(&so->so_snd_mtx, "so_snd", NULL, MTX_DEF);
416 	mtx_init(&so->so_rcv_mtx, "so_rcv", NULL, MTX_DEF);
417 	so->so_rcv.sb_sel = &so->so_rdsel;
418 	so->so_snd.sb_sel = &so->so_wrsel;
419 	sx_init(&so->so_snd_sx, "so_snd_sx");
420 	sx_init(&so->so_rcv_sx, "so_rcv_sx");
421 	TAILQ_INIT(&so->so_snd.sb_aiojobq);
422 	TAILQ_INIT(&so->so_rcv.sb_aiojobq);
423 	TASK_INIT(&so->so_snd.sb_aiotask, 0, soaio_snd, so);
424 	TASK_INIT(&so->so_rcv.sb_aiotask, 0, soaio_rcv, so);
425 #ifdef VIMAGE
426 	VNET_ASSERT(vnet != NULL, ("%s:%d vnet is NULL, so=%p",
427 	    __func__, __LINE__, so));
428 	so->so_vnet = vnet;
429 #endif
430 #ifdef SOCKET_HHOOK
431 	/* We shouldn't need the so_global_mtx */
432 	if (hhook_run_socket(so, NULL, HHOOK_SOCKET_CREATE)) {
433 		/* Do we need more comprehensive error returns? */
434 		uma_zfree(socket_zone, so);
435 		return (NULL);
436 	}
437 #endif
438 	mtx_lock(&so_global_mtx);
439 	so->so_gencnt = ++so_gencnt;
440 	++numopensockets;
441 #ifdef VIMAGE
442 	vnet->vnet_sockcnt++;
443 #endif
444 	mtx_unlock(&so_global_mtx);
445 
446 	return (so);
447 }
448 
449 /*
450  * Free the storage associated with a socket at the socket layer, tear down
451  * locks, labels, etc.  All protocol state is assumed already to have been
452  * torn down (and possibly never set up) by the caller.
453  */
454 void
455 sodealloc(struct socket *so)
456 {
457 
458 	KASSERT(so->so_count == 0, ("sodealloc(): so_count %d", so->so_count));
459 	KASSERT(so->so_pcb == NULL, ("sodealloc(): so_pcb != NULL"));
460 
461 	mtx_lock(&so_global_mtx);
462 	so->so_gencnt = ++so_gencnt;
463 	--numopensockets;	/* Could be below, but faster here. */
464 #ifdef VIMAGE
465 	VNET_ASSERT(so->so_vnet != NULL, ("%s:%d so_vnet is NULL, so=%p",
466 	    __func__, __LINE__, so));
467 	so->so_vnet->vnet_sockcnt--;
468 #endif
469 	mtx_unlock(&so_global_mtx);
470 #ifdef MAC
471 	mac_socket_destroy(so);
472 #endif
473 #ifdef SOCKET_HHOOK
474 	hhook_run_socket(so, NULL, HHOOK_SOCKET_CLOSE);
475 #endif
476 
477 	khelp_destroy_osd(&so->osd);
478 	if (SOLISTENING(so)) {
479 		if (so->sol_accept_filter != NULL)
480 			accept_filt_setopt(so, NULL);
481 	} else {
482 		if (so->so_rcv.sb_hiwat)
483 			(void)chgsbsize(so->so_cred->cr_uidinfo,
484 			    &so->so_rcv.sb_hiwat, 0, RLIM_INFINITY);
485 		if (so->so_snd.sb_hiwat)
486 			(void)chgsbsize(so->so_cred->cr_uidinfo,
487 			    &so->so_snd.sb_hiwat, 0, RLIM_INFINITY);
488 		sx_destroy(&so->so_snd_sx);
489 		sx_destroy(&so->so_rcv_sx);
490 		mtx_destroy(&so->so_snd_mtx);
491 		mtx_destroy(&so->so_rcv_mtx);
492 	}
493 	crfree(so->so_cred);
494 	mtx_destroy(&so->so_lock);
495 	uma_zfree(socket_zone, so);
496 }
497 
498 /*
499  * socreate returns a socket with a ref count of 1 and a file descriptor
500  * reference.  The socket should be closed with soclose().
501  */
502 int
503 socreate(int dom, struct socket **aso, int type, int proto,
504     struct ucred *cred, struct thread *td)
505 {
506 	struct protosw *prp;
507 	struct socket *so;
508 	int error;
509 
510 	/*
511 	 * XXX: divert(4) historically abused PF_INET.  Keep this compatibility
512 	 * shim until all applications have been updated.
513 	 */
514 	if (__predict_false(dom == PF_INET && type == SOCK_RAW &&
515 	    proto == IPPROTO_DIVERT)) {
516 		dom = PF_DIVERT;
517 		printf("%s uses obsolete way to create divert(4) socket\n",
518 		    td->td_proc->p_comm);
519 	}
520 
521 	prp = pffindproto(dom, type, proto);
522 	if (prp == NULL) {
523 		/* No support for domain. */
524 		if (pffinddomain(dom) == NULL)
525 			return (EAFNOSUPPORT);
526 		/* No support for socket type. */
527 		if (proto == 0 && type != 0)
528 			return (EPROTOTYPE);
529 		return (EPROTONOSUPPORT);
530 	}
531 
532 	MPASS(prp->pr_attach);
533 
534 	if ((prp->pr_flags & PR_CAPATTACH) == 0) {
535 		if (CAP_TRACING(td))
536 			ktrcapfail(CAPFAIL_PROTO, &proto);
537 		if (IN_CAPABILITY_MODE(td))
538 			return (ECAPMODE);
539 	}
540 
541 	if (prison_check_af(cred, prp->pr_domain->dom_family) != 0)
542 		return (EPROTONOSUPPORT);
543 
544 	so = soalloc(CRED_TO_VNET(cred));
545 	if (so == NULL)
546 		return (ENOBUFS);
547 
548 	so->so_type = type;
549 	so->so_cred = crhold(cred);
550 	if ((prp->pr_domain->dom_family == PF_INET) ||
551 	    (prp->pr_domain->dom_family == PF_INET6) ||
552 	    (prp->pr_domain->dom_family == PF_ROUTE))
553 		so->so_fibnum = td->td_proc->p_fibnum;
554 	else
555 		so->so_fibnum = 0;
556 	so->so_proto = prp;
557 #ifdef MAC
558 	mac_socket_create(cred, so);
559 #endif
560 	knlist_init(&so->so_rdsel.si_note, so, so_rdknl_lock, so_rdknl_unlock,
561 	    so_rdknl_assert_lock);
562 	knlist_init(&so->so_wrsel.si_note, so, so_wrknl_lock, so_wrknl_unlock,
563 	    so_wrknl_assert_lock);
564 	if ((prp->pr_flags & PR_SOCKBUF) == 0) {
565 		so->so_snd.sb_mtx = &so->so_snd_mtx;
566 		so->so_rcv.sb_mtx = &so->so_rcv_mtx;
567 	}
568 	/*
569 	 * Auto-sizing of socket buffers is managed by the protocols and
570 	 * the appropriate flags must be set in the pru_attach function.
571 	 */
572 	CURVNET_SET(so->so_vnet);
573 	error = prp->pr_attach(so, proto, td);
574 	CURVNET_RESTORE();
575 	if (error) {
576 		sodealloc(so);
577 		return (error);
578 	}
579 	soref(so);
580 	*aso = so;
581 	return (0);
582 }
583 
584 #ifdef REGRESSION
585 static int regression_sonewconn_earlytest = 1;
586 SYSCTL_INT(_regression, OID_AUTO, sonewconn_earlytest, CTLFLAG_RW,
587     &regression_sonewconn_earlytest, 0, "Perform early sonewconn limit test");
588 #endif
589 
590 static int sooverprio = LOG_DEBUG;
591 SYSCTL_INT(_kern_ipc, OID_AUTO, sooverprio, CTLFLAG_RW,
592     &sooverprio, 0, "Log priority for listen socket overflows: 0..7 or -1 to disable");
593 
594 static struct timeval overinterval = { 60, 0 };
595 SYSCTL_TIMEVAL_SEC(_kern_ipc, OID_AUTO, sooverinterval, CTLFLAG_RW,
596     &overinterval,
597     "Delay in seconds between warnings for listen socket overflows");
598 
599 /*
600  * When an attempt at a new connection is noted on a socket which supports
601  * accept(2), the protocol has two options:
602  * 1) Call legacy sonewconn() function, which would call protocol attach
603  *    method, same as used for socket(2).
604  * 2) Call solisten_clone(), do attach that is specific to a cloned connection,
605  *    and then call solisten_enqueue().
606  *
607  * Note: the ref count on the socket is 0 on return.
608  */
609 struct socket *
610 solisten_clone(struct socket *head)
611 {
612 	struct sbuf descrsb;
613 	struct socket *so;
614 	int len, overcount;
615 	u_int qlen;
616 	const char localprefix[] = "local:";
617 	char descrbuf[SUNPATHLEN + sizeof(localprefix)];
618 #if defined(INET6)
619 	char addrbuf[INET6_ADDRSTRLEN];
620 #elif defined(INET)
621 	char addrbuf[INET_ADDRSTRLEN];
622 #endif
623 	bool dolog, over;
624 
625 	SOLISTEN_LOCK(head);
626 	over = (head->sol_qlen > 3 * head->sol_qlimit / 2);
627 #ifdef REGRESSION
628 	if (regression_sonewconn_earlytest && over) {
629 #else
630 	if (over) {
631 #endif
632 		head->sol_overcount++;
633 		dolog = (sooverprio >= 0) &&
634 			!!ratecheck(&head->sol_lastover, &overinterval);
635 
636 		/*
637 		 * If we're going to log, copy the overflow count and queue
638 		 * length from the listen socket before dropping the lock.
639 		 * Also, reset the overflow count.
640 		 */
641 		if (dolog) {
642 			overcount = head->sol_overcount;
643 			head->sol_overcount = 0;
644 			qlen = head->sol_qlen;
645 		}
646 		SOLISTEN_UNLOCK(head);
647 
648 		if (dolog) {
649 			/*
650 			 * Try to print something descriptive about the
651 			 * socket for the error message.
652 			 */
653 			sbuf_new(&descrsb, descrbuf, sizeof(descrbuf),
654 			    SBUF_FIXEDLEN);
655 			switch (head->so_proto->pr_domain->dom_family) {
656 #if defined(INET) || defined(INET6)
657 #ifdef INET
658 			case AF_INET:
659 #endif
660 #ifdef INET6
661 			case AF_INET6:
662 				if (head->so_proto->pr_domain->dom_family ==
663 				    AF_INET6 ||
664 				    (sotoinpcb(head)->inp_inc.inc_flags &
665 				    INC_ISIPV6)) {
666 					ip6_sprintf(addrbuf,
667 					    &sotoinpcb(head)->inp_inc.inc6_laddr);
668 					sbuf_printf(&descrsb, "[%s]", addrbuf);
669 				} else
670 #endif
671 				{
672 #ifdef INET
673 					inet_ntoa_r(
674 					    sotoinpcb(head)->inp_inc.inc_laddr,
675 					    addrbuf);
676 					sbuf_cat(&descrsb, addrbuf);
677 #endif
678 				}
679 				sbuf_printf(&descrsb, ":%hu (proto %u)",
680 				    ntohs(sotoinpcb(head)->inp_inc.inc_lport),
681 				    head->so_proto->pr_protocol);
682 				break;
683 #endif /* INET || INET6 */
684 			case AF_UNIX:
685 				sbuf_cat(&descrsb, localprefix);
686 				if (sotounpcb(head)->unp_addr != NULL)
687 					len =
688 					    sotounpcb(head)->unp_addr->sun_len -
689 					    offsetof(struct sockaddr_un,
690 					    sun_path);
691 				else
692 					len = 0;
693 				if (len > 0)
694 					sbuf_bcat(&descrsb,
695 					    sotounpcb(head)->unp_addr->sun_path,
696 					    len);
697 				else
698 					sbuf_cat(&descrsb, "(unknown)");
699 				break;
700 			}
701 
702 			/*
703 			 * If we can't print something more specific, at least
704 			 * print the domain name.
705 			 */
706 			if (sbuf_finish(&descrsb) != 0 ||
707 			    sbuf_len(&descrsb) <= 0) {
708 				sbuf_clear(&descrsb);
709 				sbuf_cat(&descrsb,
710 				    head->so_proto->pr_domain->dom_name ?:
711 				    "unknown");
712 				sbuf_finish(&descrsb);
713 			}
714 			KASSERT(sbuf_len(&descrsb) > 0,
715 			    ("%s: sbuf creation failed", __func__));
716 			/*
717 			 * Preserve the historic listen queue overflow log
718 			 * message, that starts with "sonewconn:".  It has
719 			 * been known to sysadmins for years and also test
720 			 * sys/kern/sonewconn_overflow checks for it.
721 			 */
722 			if (head->so_cred == 0) {
723 				log(LOG_PRI(sooverprio),
724 				    "sonewconn: pcb %p (%s): "
725 				    "Listen queue overflow: %i already in "
726 				    "queue awaiting acceptance (%d "
727 				    "occurrences)\n", head->so_pcb,
728 				    sbuf_data(&descrsb),
729 			    	qlen, overcount);
730 			} else {
731 				log(LOG_PRI(sooverprio),
732 				    "sonewconn: pcb %p (%s): "
733 				    "Listen queue overflow: "
734 				    "%i already in queue awaiting acceptance "
735 				    "(%d occurrences), euid %d, rgid %d, jail %s\n",
736 				    head->so_pcb, sbuf_data(&descrsb), qlen,
737 				    overcount, head->so_cred->cr_uid,
738 				    head->so_cred->cr_rgid,
739 				    head->so_cred->cr_prison ?
740 					head->so_cred->cr_prison->pr_name :
741 					"not_jailed");
742 			}
743 			sbuf_delete(&descrsb);
744 
745 			overcount = 0;
746 		}
747 
748 		return (NULL);
749 	}
750 	SOLISTEN_UNLOCK(head);
751 	VNET_ASSERT(head->so_vnet != NULL, ("%s: so %p vnet is NULL",
752 	    __func__, head));
753 	so = soalloc(head->so_vnet);
754 	if (so == NULL) {
755 		log(LOG_DEBUG, "%s: pcb %p: New socket allocation failure: "
756 		    "limit reached or out of memory\n",
757 		    __func__, head->so_pcb);
758 		return (NULL);
759 	}
760 	so->so_listen = head;
761 	so->so_type = head->so_type;
762 	/*
763 	 * POSIX is ambiguous on what options an accept(2)ed socket should
764 	 * inherit from the listener.  Words "create a new socket" may be
765 	 * interpreted as not inheriting anything.  Best programming practice
766 	 * for application developers is to not rely on such inheritance.
767 	 * FreeBSD had historically inherited all so_options excluding
768 	 * SO_ACCEPTCONN, which virtually means all SOL_SOCKET level options,
769 	 * including those completely irrelevant to a new born socket.  For
770 	 * compatibility with older versions we will inherit a list of
771 	 * meaningful options.
772 	 * The crucial bit to inherit is SO_ACCEPTFILTER.  We need it present
773 	 * in the child socket for soisconnected() promoting socket from the
774 	 * incomplete queue to complete.  It will be cleared before the child
775 	 * gets available to accept(2).
776 	 */
777 	so->so_options = head->so_options & (SO_ACCEPTFILTER | SO_KEEPALIVE |
778 	    SO_DONTROUTE | SO_LINGER | SO_OOBINLINE | SO_NOSIGPIPE);
779 	so->so_linger = head->so_linger;
780 	so->so_state = head->so_state;
781 	so->so_fibnum = head->so_fibnum;
782 	so->so_proto = head->so_proto;
783 	so->so_cred = crhold(head->so_cred);
784 #ifdef SOCKET_HHOOK
785 	if (V_socket_hhh[HHOOK_SOCKET_NEWCONN]->hhh_nhooks > 0) {
786 		if (hhook_run_socket(so, head, HHOOK_SOCKET_NEWCONN)) {
787 			sodealloc(so);
788 			log(LOG_DEBUG, "%s: hhook run failed\n", __func__);
789 			return (NULL);
790 		}
791 	}
792 #endif
793 #ifdef MAC
794 	mac_socket_newconn(head, so);
795 #endif
796 	knlist_init(&so->so_rdsel.si_note, so, so_rdknl_lock, so_rdknl_unlock,
797 	    so_rdknl_assert_lock);
798 	knlist_init(&so->so_wrsel.si_note, so, so_wrknl_lock, so_wrknl_unlock,
799 	    so_wrknl_assert_lock);
800 	VNET_SO_ASSERT(head);
801 	if (soreserve(so, head->sol_sbsnd_hiwat, head->sol_sbrcv_hiwat)) {
802 		sodealloc(so);
803 		log(LOG_DEBUG, "%s: pcb %p: soreserve() failed\n",
804 		    __func__, head->so_pcb);
805 		return (NULL);
806 	}
807 	so->so_rcv.sb_lowat = head->sol_sbrcv_lowat;
808 	so->so_snd.sb_lowat = head->sol_sbsnd_lowat;
809 	so->so_rcv.sb_timeo = head->sol_sbrcv_timeo;
810 	so->so_snd.sb_timeo = head->sol_sbsnd_timeo;
811 	so->so_rcv.sb_flags = head->sol_sbrcv_flags & SB_AUTOSIZE;
812 	so->so_snd.sb_flags = head->sol_sbsnd_flags & SB_AUTOSIZE;
813 	if ((so->so_proto->pr_flags & PR_SOCKBUF) == 0) {
814 		so->so_snd.sb_mtx = &so->so_snd_mtx;
815 		so->so_rcv.sb_mtx = &so->so_rcv_mtx;
816 	}
817 
818 	return (so);
819 }
820 
821 /* Connstatus may be 0 or SS_ISCONNECTED. */
822 struct socket *
823 sonewconn(struct socket *head, int connstatus)
824 {
825 	struct socket *so;
826 
827 	if ((so = solisten_clone(head)) == NULL)
828 		return (NULL);
829 
830 	if (so->so_proto->pr_attach(so, 0, NULL) != 0) {
831 		sodealloc(so);
832 		log(LOG_DEBUG, "%s: pcb %p: pr_attach() failed\n",
833 		    __func__, head->so_pcb);
834 		return (NULL);
835 	}
836 
837 	(void)solisten_enqueue(so, connstatus);
838 
839 	return (so);
840 }
841 
842 /*
843  * Enqueue socket cloned by solisten_clone() to the listen queue of the
844  * listener it has been cloned from.
845  *
846  * Return 'true' if socket landed on complete queue, otherwise 'false'.
847  */
848 bool
849 solisten_enqueue(struct socket *so, int connstatus)
850 {
851 	struct socket *head = so->so_listen;
852 
853 	MPASS(refcount_load(&so->so_count) == 0);
854 	refcount_init(&so->so_count, 1);
855 
856 	SOLISTEN_LOCK(head);
857 	if (head->sol_accept_filter != NULL)
858 		connstatus = 0;
859 	so->so_state |= connstatus;
860 	soref(head); /* A socket on (in)complete queue refs head. */
861 	if (connstatus) {
862 		TAILQ_INSERT_TAIL(&head->sol_comp, so, so_list);
863 		so->so_qstate = SQ_COMP;
864 		head->sol_qlen++;
865 		solisten_wakeup(head);	/* unlocks */
866 		return (true);
867 	} else {
868 		/*
869 		 * Keep removing sockets from the head until there's room for
870 		 * us to insert on the tail.  In pre-locking revisions, this
871 		 * was a simple if(), but as we could be racing with other
872 		 * threads and soabort() requires dropping locks, we must
873 		 * loop waiting for the condition to be true.
874 		 */
875 		while (head->sol_incqlen > head->sol_qlimit) {
876 			struct socket *sp;
877 
878 			sp = TAILQ_FIRST(&head->sol_incomp);
879 			TAILQ_REMOVE(&head->sol_incomp, sp, so_list);
880 			head->sol_incqlen--;
881 			SOCK_LOCK(sp);
882 			sp->so_qstate = SQ_NONE;
883 			sp->so_listen = NULL;
884 			SOCK_UNLOCK(sp);
885 			sorele_locked(head);	/* does SOLISTEN_UNLOCK, head stays */
886 			soabort(sp);
887 			SOLISTEN_LOCK(head);
888 		}
889 		TAILQ_INSERT_TAIL(&head->sol_incomp, so, so_list);
890 		so->so_qstate = SQ_INCOMP;
891 		head->sol_incqlen++;
892 		SOLISTEN_UNLOCK(head);
893 		return (false);
894 	}
895 }
896 
897 #if defined(SCTP) || defined(SCTP_SUPPORT)
898 /*
899  * Socket part of sctp_peeloff().  Detach a new socket from an
900  * association.  The new socket is returned with a reference.
901  *
902  * XXXGL: reduce copy-paste with solisten_clone().
903  */
904 struct socket *
905 sopeeloff(struct socket *head)
906 {
907 	struct socket *so;
908 
909 	VNET_ASSERT(head->so_vnet != NULL, ("%s:%d so_vnet is NULL, head=%p",
910 	    __func__, __LINE__, head));
911 	so = soalloc(head->so_vnet);
912 	if (so == NULL) {
913 		log(LOG_DEBUG, "%s: pcb %p: New socket allocation failure: "
914 		    "limit reached or out of memory\n",
915 		    __func__, head->so_pcb);
916 		return (NULL);
917 	}
918 	so->so_type = head->so_type;
919 	so->so_options = head->so_options;
920 	so->so_linger = head->so_linger;
921 	so->so_state = (head->so_state & SS_NBIO) | SS_ISCONNECTED;
922 	so->so_fibnum = head->so_fibnum;
923 	so->so_proto = head->so_proto;
924 	so->so_cred = crhold(head->so_cred);
925 #ifdef MAC
926 	mac_socket_newconn(head, so);
927 #endif
928 	knlist_init(&so->so_rdsel.si_note, so, so_rdknl_lock, so_rdknl_unlock,
929 	    so_rdknl_assert_lock);
930 	knlist_init(&so->so_wrsel.si_note, so, so_wrknl_lock, so_wrknl_unlock,
931 	    so_wrknl_assert_lock);
932 	VNET_SO_ASSERT(head);
933 	if (soreserve(so, head->so_snd.sb_hiwat, head->so_rcv.sb_hiwat)) {
934 		sodealloc(so);
935 		log(LOG_DEBUG, "%s: pcb %p: soreserve() failed\n",
936 		    __func__, head->so_pcb);
937 		return (NULL);
938 	}
939 	if ((*so->so_proto->pr_attach)(so, 0, NULL)) {
940 		sodealloc(so);
941 		log(LOG_DEBUG, "%s: pcb %p: pru_attach() failed\n",
942 		    __func__, head->so_pcb);
943 		return (NULL);
944 	}
945 	so->so_rcv.sb_lowat = head->so_rcv.sb_lowat;
946 	so->so_snd.sb_lowat = head->so_snd.sb_lowat;
947 	so->so_rcv.sb_timeo = head->so_rcv.sb_timeo;
948 	so->so_snd.sb_timeo = head->so_snd.sb_timeo;
949 	so->so_rcv.sb_flags |= head->so_rcv.sb_flags & SB_AUTOSIZE;
950 	so->so_snd.sb_flags |= head->so_snd.sb_flags & SB_AUTOSIZE;
951 	if ((so->so_proto->pr_flags & PR_SOCKBUF) == 0) {
952 		so->so_snd.sb_mtx = &so->so_snd_mtx;
953 		so->so_rcv.sb_mtx = &so->so_rcv_mtx;
954 	}
955 
956 	soref(so);
957 
958 	return (so);
959 }
960 #endif	/* SCTP */
961 
962 int
963 sobind(struct socket *so, struct sockaddr *nam, struct thread *td)
964 {
965 	int error;
966 
967 	CURVNET_SET(so->so_vnet);
968 	error = so->so_proto->pr_bind(so, nam, td);
969 	CURVNET_RESTORE();
970 	return (error);
971 }
972 
973 int
974 sobindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
975 {
976 	int error;
977 
978 	CURVNET_SET(so->so_vnet);
979 	error = so->so_proto->pr_bindat(fd, so, nam, td);
980 	CURVNET_RESTORE();
981 	return (error);
982 }
983 
984 /*
985  * solisten() transitions a socket from a non-listening state to a listening
986  * state, but can also be used to update the listen queue depth on an
987  * existing listen socket.  The protocol will call back into the sockets
988  * layer using solisten_proto_check() and solisten_proto() to check and set
989  * socket-layer listen state.  Call backs are used so that the protocol can
990  * acquire both protocol and socket layer locks in whatever order is required
991  * by the protocol.
992  *
993  * Protocol implementors are advised to hold the socket lock across the
994  * socket-layer test and set to avoid races at the socket layer.
995  */
996 int
997 solisten(struct socket *so, int backlog, struct thread *td)
998 {
999 	int error;
1000 
1001 	CURVNET_SET(so->so_vnet);
1002 	error = so->so_proto->pr_listen(so, backlog, td);
1003 	CURVNET_RESTORE();
1004 	return (error);
1005 }
1006 
1007 /*
1008  * Prepare for a call to solisten_proto().  Acquire all socket buffer locks in
1009  * order to interlock with socket I/O.
1010  */
1011 int
1012 solisten_proto_check(struct socket *so)
1013 {
1014 	SOCK_LOCK_ASSERT(so);
1015 
1016 	if ((so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING |
1017 	    SS_ISDISCONNECTING)) != 0)
1018 		return (EINVAL);
1019 
1020 	/*
1021 	 * Sleeping is not permitted here, so simply fail if userspace is
1022 	 * attempting to transmit or receive on the socket.  This kind of
1023 	 * transient failure is not ideal, but it should occur only if userspace
1024 	 * is misusing the socket interfaces.
1025 	 */
1026 	if (!sx_try_xlock(&so->so_snd_sx))
1027 		return (EAGAIN);
1028 	if (!sx_try_xlock(&so->so_rcv_sx)) {
1029 		sx_xunlock(&so->so_snd_sx);
1030 		return (EAGAIN);
1031 	}
1032 	mtx_lock(&so->so_snd_mtx);
1033 	mtx_lock(&so->so_rcv_mtx);
1034 
1035 	/* Interlock with soo_aio_queue() and KTLS. */
1036 	if (!SOLISTENING(so)) {
1037 		bool ktls;
1038 
1039 #ifdef KERN_TLS
1040 		ktls = so->so_snd.sb_tls_info != NULL ||
1041 		    so->so_rcv.sb_tls_info != NULL;
1042 #else
1043 		ktls = false;
1044 #endif
1045 		if (ktls ||
1046 		    (so->so_snd.sb_flags & (SB_AIO | SB_AIO_RUNNING)) != 0 ||
1047 		    (so->so_rcv.sb_flags & (SB_AIO | SB_AIO_RUNNING)) != 0) {
1048 			solisten_proto_abort(so);
1049 			return (EINVAL);
1050 		}
1051 	}
1052 
1053 	return (0);
1054 }
1055 
1056 /*
1057  * Undo the setup done by solisten_proto_check().
1058  */
1059 void
1060 solisten_proto_abort(struct socket *so)
1061 {
1062 	mtx_unlock(&so->so_snd_mtx);
1063 	mtx_unlock(&so->so_rcv_mtx);
1064 	sx_xunlock(&so->so_snd_sx);
1065 	sx_xunlock(&so->so_rcv_sx);
1066 }
1067 
1068 void
1069 solisten_proto(struct socket *so, int backlog)
1070 {
1071 	int sbrcv_lowat, sbsnd_lowat;
1072 	u_int sbrcv_hiwat, sbsnd_hiwat;
1073 	short sbrcv_flags, sbsnd_flags;
1074 	sbintime_t sbrcv_timeo, sbsnd_timeo;
1075 
1076 	SOCK_LOCK_ASSERT(so);
1077 	KASSERT((so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING |
1078 	    SS_ISDISCONNECTING)) == 0,
1079 	    ("%s: bad socket state %p", __func__, so));
1080 
1081 	if (SOLISTENING(so))
1082 		goto listening;
1083 
1084 	/*
1085 	 * Change this socket to listening state.
1086 	 */
1087 	sbrcv_lowat = so->so_rcv.sb_lowat;
1088 	sbsnd_lowat = so->so_snd.sb_lowat;
1089 	sbrcv_hiwat = so->so_rcv.sb_hiwat;
1090 	sbsnd_hiwat = so->so_snd.sb_hiwat;
1091 	sbrcv_flags = so->so_rcv.sb_flags;
1092 	sbsnd_flags = so->so_snd.sb_flags;
1093 	sbrcv_timeo = so->so_rcv.sb_timeo;
1094 	sbsnd_timeo = so->so_snd.sb_timeo;
1095 
1096 	if (!(so->so_proto->pr_flags & PR_SOCKBUF)) {
1097 		sbdestroy(so, SO_SND);
1098 		sbdestroy(so, SO_RCV);
1099 	}
1100 
1101 #ifdef INVARIANTS
1102 	bzero(&so->so_rcv,
1103 	    sizeof(struct socket) - offsetof(struct socket, so_rcv));
1104 #endif
1105 
1106 	so->sol_sbrcv_lowat = sbrcv_lowat;
1107 	so->sol_sbsnd_lowat = sbsnd_lowat;
1108 	so->sol_sbrcv_hiwat = sbrcv_hiwat;
1109 	so->sol_sbsnd_hiwat = sbsnd_hiwat;
1110 	so->sol_sbrcv_flags = sbrcv_flags;
1111 	so->sol_sbsnd_flags = sbsnd_flags;
1112 	so->sol_sbrcv_timeo = sbrcv_timeo;
1113 	so->sol_sbsnd_timeo = sbsnd_timeo;
1114 
1115 	so->sol_qlen = so->sol_incqlen = 0;
1116 	TAILQ_INIT(&so->sol_incomp);
1117 	TAILQ_INIT(&so->sol_comp);
1118 
1119 	so->sol_accept_filter = NULL;
1120 	so->sol_accept_filter_arg = NULL;
1121 	so->sol_accept_filter_str = NULL;
1122 
1123 	so->sol_upcall = NULL;
1124 	so->sol_upcallarg = NULL;
1125 
1126 	so->so_options |= SO_ACCEPTCONN;
1127 
1128 listening:
1129 	if (backlog < 0 || backlog > somaxconn)
1130 		backlog = somaxconn;
1131 	so->sol_qlimit = backlog;
1132 
1133 	mtx_unlock(&so->so_snd_mtx);
1134 	mtx_unlock(&so->so_rcv_mtx);
1135 	sx_xunlock(&so->so_snd_sx);
1136 	sx_xunlock(&so->so_rcv_sx);
1137 }
1138 
1139 /*
1140  * Wakeup listeners/subsystems once we have a complete connection.
1141  * Enters with lock, returns unlocked.
1142  */
1143 void
1144 solisten_wakeup(struct socket *sol)
1145 {
1146 
1147 	if (sol->sol_upcall != NULL)
1148 		(void )sol->sol_upcall(sol, sol->sol_upcallarg, M_NOWAIT);
1149 	else {
1150 		selwakeuppri(&sol->so_rdsel, PSOCK);
1151 		KNOTE_LOCKED(&sol->so_rdsel.si_note, 0);
1152 	}
1153 	SOLISTEN_UNLOCK(sol);
1154 	wakeup_one(&sol->sol_comp);
1155 	if ((sol->so_state & SS_ASYNC) && sol->so_sigio != NULL)
1156 		pgsigio(&sol->so_sigio, SIGIO, 0);
1157 }
1158 
1159 /*
1160  * Return single connection off a listening socket queue.  Main consumer of
1161  * the function is kern_accept4().  Some modules, that do their own accept
1162  * management also use the function.  The socket reference held by the
1163  * listen queue is handed to the caller.
1164  *
1165  * Listening socket must be locked on entry and is returned unlocked on
1166  * return.
1167  * The flags argument is set of accept4(2) flags and ACCEPT4_INHERIT.
1168  */
1169 int
1170 solisten_dequeue(struct socket *head, struct socket **ret, int flags)
1171 {
1172 	struct socket *so;
1173 	int error;
1174 
1175 	SOLISTEN_LOCK_ASSERT(head);
1176 
1177 	while (!(head->so_state & SS_NBIO) && TAILQ_EMPTY(&head->sol_comp) &&
1178 	    head->so_error == 0) {
1179 		error = msleep(&head->sol_comp, SOCK_MTX(head), PSOCK | PCATCH,
1180 		    "accept", 0);
1181 		if (error != 0) {
1182 			SOLISTEN_UNLOCK(head);
1183 			return (error);
1184 		}
1185 	}
1186 	if (head->so_error) {
1187 		error = head->so_error;
1188 		head->so_error = 0;
1189 	} else if ((head->so_state & SS_NBIO) && TAILQ_EMPTY(&head->sol_comp))
1190 		error = EWOULDBLOCK;
1191 	else
1192 		error = 0;
1193 	if (error) {
1194 		SOLISTEN_UNLOCK(head);
1195 		return (error);
1196 	}
1197 	so = TAILQ_FIRST(&head->sol_comp);
1198 	SOCK_LOCK(so);
1199 	KASSERT(so->so_qstate == SQ_COMP,
1200 	    ("%s: so %p not SQ_COMP", __func__, so));
1201 	head->sol_qlen--;
1202 	so->so_qstate = SQ_NONE;
1203 	so->so_listen = NULL;
1204 	TAILQ_REMOVE(&head->sol_comp, so, so_list);
1205 	if (flags & ACCEPT4_INHERIT)
1206 		so->so_state |= (head->so_state & SS_NBIO);
1207 	else
1208 		so->so_state |= (flags & SOCK_NONBLOCK) ? SS_NBIO : 0;
1209 	SOCK_UNLOCK(so);
1210 	sorele_locked(head);
1211 
1212 	*ret = so;
1213 	return (0);
1214 }
1215 
1216 /*
1217  * Free socket upon release of the very last reference.
1218  */
1219 static void
1220 sofree(struct socket *so)
1221 {
1222 	struct protosw *pr = so->so_proto;
1223 
1224 	SOCK_LOCK_ASSERT(so);
1225 	KASSERT(refcount_load(&so->so_count) == 0,
1226 	    ("%s: so %p has references", __func__, so));
1227 	KASSERT(SOLISTENING(so) || so->so_qstate == SQ_NONE,
1228 	    ("%s: so %p is on listen queue", __func__, so));
1229 
1230 	SOCK_UNLOCK(so);
1231 
1232 	if (so->so_dtor != NULL)
1233 		so->so_dtor(so);
1234 
1235 	VNET_SO_ASSERT(so);
1236 	if (pr->pr_detach != NULL)
1237 		pr->pr_detach(so);
1238 
1239 	/*
1240 	 * From this point on, we assume that no other references to this
1241 	 * socket exist anywhere else in the stack.  Therefore, no locks need
1242 	 * to be acquired or held.
1243 	 */
1244 	if (!(pr->pr_flags & PR_SOCKBUF) && !SOLISTENING(so)) {
1245 		sbdestroy(so, SO_SND);
1246 		sbdestroy(so, SO_RCV);
1247 	}
1248 	seldrain(&so->so_rdsel);
1249 	seldrain(&so->so_wrsel);
1250 	knlist_destroy(&so->so_rdsel.si_note);
1251 	knlist_destroy(&so->so_wrsel.si_note);
1252 	sodealloc(so);
1253 }
1254 
1255 /*
1256  * Release a reference on a socket while holding the socket lock.
1257  * Unlocks the socket lock before returning.
1258  */
1259 void
1260 sorele_locked(struct socket *so)
1261 {
1262 	SOCK_LOCK_ASSERT(so);
1263 	if (refcount_release(&so->so_count))
1264 		sofree(so);
1265 	else
1266 		SOCK_UNLOCK(so);
1267 }
1268 
1269 /*
1270  * Close a socket on last file table reference removal.  Initiate disconnect
1271  * if connected.  Free socket when disconnect complete.
1272  *
1273  * This function will sorele() the socket.  Note that soclose() may be called
1274  * prior to the ref count reaching zero.  The actual socket structure will
1275  * not be freed until the ref count reaches zero.
1276  */
1277 int
1278 soclose(struct socket *so)
1279 {
1280 	struct accept_queue lqueue;
1281 	int error = 0;
1282 	bool listening, last __diagused;
1283 
1284 	CURVNET_SET(so->so_vnet);
1285 	funsetown(&so->so_sigio);
1286 	if (so->so_state & SS_ISCONNECTED) {
1287 		if ((so->so_state & SS_ISDISCONNECTING) == 0) {
1288 			error = sodisconnect(so);
1289 			if (error) {
1290 				if (error == ENOTCONN)
1291 					error = 0;
1292 				goto drop;
1293 			}
1294 		}
1295 
1296 		if ((so->so_options & SO_LINGER) != 0 && so->so_linger != 0) {
1297 			if ((so->so_state & SS_ISDISCONNECTING) &&
1298 			    (so->so_state & SS_NBIO))
1299 				goto drop;
1300 			while (so->so_state & SS_ISCONNECTED) {
1301 				error = tsleep(&so->so_timeo,
1302 				    PSOCK | PCATCH, "soclos",
1303 				    so->so_linger * hz);
1304 				if (error)
1305 					break;
1306 			}
1307 		}
1308 	}
1309 
1310 drop:
1311 	if (so->so_proto->pr_close != NULL)
1312 		so->so_proto->pr_close(so);
1313 
1314 	SOCK_LOCK(so);
1315 	if ((listening = SOLISTENING(so))) {
1316 		struct socket *sp;
1317 
1318 		TAILQ_INIT(&lqueue);
1319 		TAILQ_SWAP(&lqueue, &so->sol_incomp, socket, so_list);
1320 		TAILQ_CONCAT(&lqueue, &so->sol_comp, so_list);
1321 
1322 		so->sol_qlen = so->sol_incqlen = 0;
1323 
1324 		TAILQ_FOREACH(sp, &lqueue, so_list) {
1325 			SOCK_LOCK(sp);
1326 			sp->so_qstate = SQ_NONE;
1327 			sp->so_listen = NULL;
1328 			SOCK_UNLOCK(sp);
1329 			last = refcount_release(&so->so_count);
1330 			KASSERT(!last, ("%s: released last reference for %p",
1331 			    __func__, so));
1332 		}
1333 	}
1334 	sorele_locked(so);
1335 	if (listening) {
1336 		struct socket *sp, *tsp;
1337 
1338 		TAILQ_FOREACH_SAFE(sp, &lqueue, so_list, tsp)
1339 			soabort(sp);
1340 	}
1341 	CURVNET_RESTORE();
1342 	return (error);
1343 }
1344 
1345 /*
1346  * soabort() is used to abruptly tear down a connection, such as when a
1347  * resource limit is reached (listen queue depth exceeded), or if a listen
1348  * socket is closed while there are sockets waiting to be accepted.
1349  *
1350  * This interface is tricky, because it is called on an unreferenced socket,
1351  * and must be called only by a thread that has actually removed the socket
1352  * from the listen queue it was on.  Likely this thread holds the last
1353  * reference on the socket and soabort() will proceed with sofree().  But
1354  * it might be not the last, as the sockets on the listen queues are seen
1355  * from the protocol side.
1356  *
1357  * This interface will call into the protocol code, so must not be called
1358  * with any socket locks held.  Protocols do call it while holding their own
1359  * recursible protocol mutexes, but this is something that should be subject
1360  * to review in the future.
1361  *
1362  * Usually socket should have a single reference left, but this is not a
1363  * requirement.  In the past, when we have had named references for file
1364  * descriptor and protocol, we asserted that none of them are being held.
1365  */
1366 void
1367 soabort(struct socket *so)
1368 {
1369 
1370 	VNET_SO_ASSERT(so);
1371 
1372 	if (so->so_proto->pr_abort != NULL)
1373 		so->so_proto->pr_abort(so);
1374 	SOCK_LOCK(so);
1375 	sorele_locked(so);
1376 }
1377 
1378 int
1379 soaccept(struct socket *so, struct sockaddr *sa)
1380 {
1381 #ifdef INVARIANTS
1382 	u_char len = sa->sa_len;
1383 #endif
1384 	int error;
1385 
1386 	CURVNET_SET(so->so_vnet);
1387 	error = so->so_proto->pr_accept(so, sa);
1388 	KASSERT(sa->sa_len <= len,
1389 	    ("%s: protocol %p sockaddr overflow", __func__, so->so_proto));
1390 	CURVNET_RESTORE();
1391 	return (error);
1392 }
1393 
1394 int
1395 sopeeraddr(struct socket *so, struct sockaddr *sa)
1396 {
1397 #ifdef INVARIANTS
1398 	u_char len = sa->sa_len;
1399 #endif
1400 	int error;
1401 
1402 	CURVNET_SET(so->so_vnet);
1403 	error = so->so_proto->pr_peeraddr(so, sa);
1404 	KASSERT(sa->sa_len <= len,
1405 	    ("%s: protocol %p sockaddr overflow", __func__, so->so_proto));
1406 	CURVNET_RESTORE();
1407 
1408 	return (error);
1409 }
1410 
1411 int
1412 sosockaddr(struct socket *so, struct sockaddr *sa)
1413 {
1414 #ifdef INVARIANTS
1415 	u_char len = sa->sa_len;
1416 #endif
1417 	int error;
1418 
1419 	CURVNET_SET(so->so_vnet);
1420 	error = so->so_proto->pr_sockaddr(so, sa);
1421 	KASSERT(sa->sa_len <= len,
1422 	    ("%s: protocol %p sockaddr overflow", __func__, so->so_proto));
1423 	CURVNET_RESTORE();
1424 
1425 	return (error);
1426 }
1427 
1428 int
1429 soconnect(struct socket *so, struct sockaddr *nam, struct thread *td)
1430 {
1431 
1432 	return (soconnectat(AT_FDCWD, so, nam, td));
1433 }
1434 
1435 int
1436 soconnectat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
1437 {
1438 	int error;
1439 
1440 	CURVNET_SET(so->so_vnet);
1441 
1442 	/*
1443 	 * If protocol is connection-based, can only connect once.
1444 	 * Otherwise, if connected, try to disconnect first.  This allows
1445 	 * user to disconnect by connecting to, e.g., a null address.
1446 	 *
1447 	 * Note, this check is racy and may need to be re-evaluated at the
1448 	 * protocol layer.
1449 	 */
1450 	if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
1451 	    ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
1452 	    (error = sodisconnect(so)))) {
1453 		error = EISCONN;
1454 	} else {
1455 		/*
1456 		 * Prevent accumulated error from previous connection from
1457 		 * biting us.
1458 		 */
1459 		so->so_error = 0;
1460 		if (fd == AT_FDCWD) {
1461 			error = so->so_proto->pr_connect(so, nam, td);
1462 		} else {
1463 			error = so->so_proto->pr_connectat(fd, so, nam, td);
1464 		}
1465 	}
1466 	CURVNET_RESTORE();
1467 
1468 	return (error);
1469 }
1470 
1471 int
1472 soconnect2(struct socket *so1, struct socket *so2)
1473 {
1474 	int error;
1475 
1476 	CURVNET_SET(so1->so_vnet);
1477 	error = so1->so_proto->pr_connect2(so1, so2);
1478 	CURVNET_RESTORE();
1479 	return (error);
1480 }
1481 
1482 int
1483 sodisconnect(struct socket *so)
1484 {
1485 	int error;
1486 
1487 	if ((so->so_state & SS_ISCONNECTED) == 0)
1488 		return (ENOTCONN);
1489 	if (so->so_state & SS_ISDISCONNECTING)
1490 		return (EALREADY);
1491 	VNET_SO_ASSERT(so);
1492 	error = so->so_proto->pr_disconnect(so);
1493 	return (error);
1494 }
1495 
1496 int
1497 sosend_dgram(struct socket *so, struct sockaddr *addr, struct uio *uio,
1498     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
1499 {
1500 	long space;
1501 	ssize_t resid;
1502 	int clen = 0, error, dontroute;
1503 
1504 	KASSERT(so->so_type == SOCK_DGRAM, ("sosend_dgram: !SOCK_DGRAM"));
1505 	KASSERT(so->so_proto->pr_flags & PR_ATOMIC,
1506 	    ("sosend_dgram: !PR_ATOMIC"));
1507 
1508 	if (uio != NULL)
1509 		resid = uio->uio_resid;
1510 	else
1511 		resid = top->m_pkthdr.len;
1512 	/*
1513 	 * In theory resid should be unsigned.  However, space must be
1514 	 * signed, as it might be less than 0 if we over-committed, and we
1515 	 * must use a signed comparison of space and resid.  On the other
1516 	 * hand, a negative resid causes us to loop sending 0-length
1517 	 * segments to the protocol.
1518 	 */
1519 	if (resid < 0) {
1520 		error = EINVAL;
1521 		goto out;
1522 	}
1523 
1524 	dontroute =
1525 	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0;
1526 	if (td != NULL)
1527 		td->td_ru.ru_msgsnd++;
1528 	if (control != NULL)
1529 		clen = control->m_len;
1530 
1531 	SOCKBUF_LOCK(&so->so_snd);
1532 	if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
1533 		SOCKBUF_UNLOCK(&so->so_snd);
1534 		error = EPIPE;
1535 		goto out;
1536 	}
1537 	if (so->so_error) {
1538 		error = so->so_error;
1539 		so->so_error = 0;
1540 		SOCKBUF_UNLOCK(&so->so_snd);
1541 		goto out;
1542 	}
1543 	if ((so->so_state & SS_ISCONNECTED) == 0) {
1544 		/*
1545 		 * `sendto' and `sendmsg' is allowed on a connection-based
1546 		 * socket if it supports implied connect.  Return ENOTCONN if
1547 		 * not connected and no address is supplied.
1548 		 */
1549 		if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
1550 		    (so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
1551 			if (!(resid == 0 && clen != 0)) {
1552 				SOCKBUF_UNLOCK(&so->so_snd);
1553 				error = ENOTCONN;
1554 				goto out;
1555 			}
1556 		} else if (addr == NULL) {
1557 			if (so->so_proto->pr_flags & PR_CONNREQUIRED)
1558 				error = ENOTCONN;
1559 			else
1560 				error = EDESTADDRREQ;
1561 			SOCKBUF_UNLOCK(&so->so_snd);
1562 			goto out;
1563 		}
1564 	}
1565 
1566 	/*
1567 	 * Do we need MSG_OOB support in SOCK_DGRAM?  Signs here may be a
1568 	 * problem and need fixing.
1569 	 */
1570 	space = sbspace(&so->so_snd);
1571 	if (flags & MSG_OOB)
1572 		space += 1024;
1573 	space -= clen;
1574 	SOCKBUF_UNLOCK(&so->so_snd);
1575 	if (resid > space) {
1576 		error = EMSGSIZE;
1577 		goto out;
1578 	}
1579 	if (uio == NULL) {
1580 		resid = 0;
1581 		if (flags & MSG_EOR)
1582 			top->m_flags |= M_EOR;
1583 	} else {
1584 		/*
1585 		 * Copy the data from userland into a mbuf chain.
1586 		 * If no data is to be copied in, a single empty mbuf
1587 		 * is returned.
1588 		 */
1589 		top = m_uiotombuf(uio, M_WAITOK, space, max_hdr,
1590 		    (M_PKTHDR | ((flags & MSG_EOR) ? M_EOR : 0)));
1591 		if (top == NULL) {
1592 			error = EFAULT;	/* only possible error */
1593 			goto out;
1594 		}
1595 		space -= resid - uio->uio_resid;
1596 		resid = uio->uio_resid;
1597 	}
1598 	KASSERT(resid == 0, ("sosend_dgram: resid != 0"));
1599 	/*
1600 	 * XXXRW: Frobbing SO_DONTROUTE here is even worse without sblock
1601 	 * than with.
1602 	 */
1603 	if (dontroute) {
1604 		SOCK_LOCK(so);
1605 		so->so_options |= SO_DONTROUTE;
1606 		SOCK_UNLOCK(so);
1607 	}
1608 	/*
1609 	 * XXX all the SBS_CANTSENDMORE checks previously done could be out
1610 	 * of date.  We could have received a reset packet in an interrupt or
1611 	 * maybe we slept while doing page faults in uiomove() etc.  We could
1612 	 * probably recheck again inside the locking protection here, but
1613 	 * there are probably other places that this also happens.  We must
1614 	 * rethink this.
1615 	 */
1616 	VNET_SO_ASSERT(so);
1617 	error = so->so_proto->pr_send(so, (flags & MSG_OOB) ? PRUS_OOB :
1618 	/*
1619 	 * If the user set MSG_EOF, the protocol understands this flag and
1620 	 * nothing left to send then use PRU_SEND_EOF instead of PRU_SEND.
1621 	 */
1622 	    ((flags & MSG_EOF) &&
1623 	     (so->so_proto->pr_flags & PR_IMPLOPCL) &&
1624 	     (resid <= 0)) ?
1625 		PRUS_EOF :
1626 		/* If there is more to send set PRUS_MORETOCOME */
1627 		(flags & MSG_MORETOCOME) ||
1628 		(resid > 0 && space > 0) ? PRUS_MORETOCOME : 0,
1629 		top, addr, control, td);
1630 	if (dontroute) {
1631 		SOCK_LOCK(so);
1632 		so->so_options &= ~SO_DONTROUTE;
1633 		SOCK_UNLOCK(so);
1634 	}
1635 	clen = 0;
1636 	control = NULL;
1637 	top = NULL;
1638 out:
1639 	if (top != NULL)
1640 		m_freem(top);
1641 	if (control != NULL)
1642 		m_freem(control);
1643 	return (error);
1644 }
1645 
1646 /*
1647  * Send on a socket.  If send must go all at once and message is larger than
1648  * send buffering, then hard error.  Lock against other senders.  If must go
1649  * all at once and not enough room now, then inform user that this would
1650  * block and do nothing.  Otherwise, if nonblocking, send as much as
1651  * possible.  The data to be sent is described by "uio" if nonzero, otherwise
1652  * by the mbuf chain "top" (which must be null if uio is not).  Data provided
1653  * in mbuf chain must be small enough to send all at once.
1654  *
1655  * Returns nonzero on error, timeout or signal; callers must check for short
1656  * counts if EINTR/ERESTART are returned.  Data and control buffers are freed
1657  * on return.
1658  */
1659 int
1660 sosend_generic(struct socket *so, struct sockaddr *addr, struct uio *uio,
1661     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
1662 {
1663 	long space;
1664 	ssize_t resid;
1665 	int clen = 0, error, dontroute;
1666 	int atomic = sosendallatonce(so) || top;
1667 	int pr_send_flag;
1668 #ifdef KERN_TLS
1669 	struct ktls_session *tls;
1670 	int tls_enq_cnt, tls_send_flag;
1671 	uint8_t tls_rtype;
1672 
1673 	tls = NULL;
1674 	tls_rtype = TLS_RLTYPE_APP;
1675 #endif
1676 	if (uio != NULL)
1677 		resid = uio->uio_resid;
1678 	else if ((top->m_flags & M_PKTHDR) != 0)
1679 		resid = top->m_pkthdr.len;
1680 	else
1681 		resid = m_length(top, NULL);
1682 	/*
1683 	 * In theory resid should be unsigned.  However, space must be
1684 	 * signed, as it might be less than 0 if we over-committed, and we
1685 	 * must use a signed comparison of space and resid.  On the other
1686 	 * hand, a negative resid causes us to loop sending 0-length
1687 	 * segments to the protocol.
1688 	 *
1689 	 * Also check to make sure that MSG_EOR isn't used on SOCK_STREAM
1690 	 * type sockets since that's an error.
1691 	 */
1692 	if (resid < 0 || (so->so_type == SOCK_STREAM && (flags & MSG_EOR))) {
1693 		error = EINVAL;
1694 		goto out;
1695 	}
1696 
1697 	dontroute =
1698 	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
1699 	    (so->so_proto->pr_flags & PR_ATOMIC);
1700 	if (td != NULL)
1701 		td->td_ru.ru_msgsnd++;
1702 	if (control != NULL)
1703 		clen = control->m_len;
1704 
1705 	error = SOCK_IO_SEND_LOCK(so, SBLOCKWAIT(flags));
1706 	if (error)
1707 		goto out;
1708 
1709 #ifdef KERN_TLS
1710 	tls_send_flag = 0;
1711 	tls = ktls_hold(so->so_snd.sb_tls_info);
1712 	if (tls != NULL) {
1713 		if (tls->mode == TCP_TLS_MODE_SW)
1714 			tls_send_flag = PRUS_NOTREADY;
1715 
1716 		if (control != NULL) {
1717 			struct cmsghdr *cm = mtod(control, struct cmsghdr *);
1718 
1719 			if (clen >= sizeof(*cm) &&
1720 			    cm->cmsg_type == TLS_SET_RECORD_TYPE) {
1721 				tls_rtype = *((uint8_t *)CMSG_DATA(cm));
1722 				clen = 0;
1723 				m_freem(control);
1724 				control = NULL;
1725 				atomic = 1;
1726 			}
1727 		}
1728 
1729 		if (resid == 0 && !ktls_permit_empty_frames(tls)) {
1730 			error = EINVAL;
1731 			goto release;
1732 		}
1733 	}
1734 #endif
1735 
1736 restart:
1737 	do {
1738 		SOCKBUF_LOCK(&so->so_snd);
1739 		if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
1740 			SOCKBUF_UNLOCK(&so->so_snd);
1741 			error = EPIPE;
1742 			goto release;
1743 		}
1744 		if (so->so_error) {
1745 			error = so->so_error;
1746 			so->so_error = 0;
1747 			SOCKBUF_UNLOCK(&so->so_snd);
1748 			goto release;
1749 		}
1750 		if ((so->so_state & SS_ISCONNECTED) == 0) {
1751 			/*
1752 			 * `sendto' and `sendmsg' is allowed on a connection-
1753 			 * based socket if it supports implied connect.
1754 			 * Return ENOTCONN if not connected and no address is
1755 			 * supplied.
1756 			 */
1757 			if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
1758 			    (so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
1759 				if (!(resid == 0 && clen != 0)) {
1760 					SOCKBUF_UNLOCK(&so->so_snd);
1761 					error = ENOTCONN;
1762 					goto release;
1763 				}
1764 			} else if (addr == NULL) {
1765 				SOCKBUF_UNLOCK(&so->so_snd);
1766 				if (so->so_proto->pr_flags & PR_CONNREQUIRED)
1767 					error = ENOTCONN;
1768 				else
1769 					error = EDESTADDRREQ;
1770 				goto release;
1771 			}
1772 		}
1773 		space = sbspace(&so->so_snd);
1774 		if (flags & MSG_OOB)
1775 			space += 1024;
1776 		if ((atomic && resid > so->so_snd.sb_hiwat) ||
1777 		    clen > so->so_snd.sb_hiwat) {
1778 			SOCKBUF_UNLOCK(&so->so_snd);
1779 			error = EMSGSIZE;
1780 			goto release;
1781 		}
1782 		if (space < resid + clen &&
1783 		    (atomic || space < so->so_snd.sb_lowat || space < clen)) {
1784 			if ((so->so_state & SS_NBIO) ||
1785 			    (flags & (MSG_NBIO | MSG_DONTWAIT)) != 0) {
1786 				SOCKBUF_UNLOCK(&so->so_snd);
1787 				error = EWOULDBLOCK;
1788 				goto release;
1789 			}
1790 			error = sbwait(so, SO_SND);
1791 			SOCKBUF_UNLOCK(&so->so_snd);
1792 			if (error)
1793 				goto release;
1794 			goto restart;
1795 		}
1796 		SOCKBUF_UNLOCK(&so->so_snd);
1797 		space -= clen;
1798 		do {
1799 			if (uio == NULL) {
1800 				resid = 0;
1801 				if (flags & MSG_EOR)
1802 					top->m_flags |= M_EOR;
1803 #ifdef KERN_TLS
1804 				if (tls != NULL) {
1805 					ktls_frame(top, tls, &tls_enq_cnt,
1806 					    tls_rtype);
1807 					tls_rtype = TLS_RLTYPE_APP;
1808 				}
1809 #endif
1810 			} else {
1811 				/*
1812 				 * Copy the data from userland into a mbuf
1813 				 * chain.  If resid is 0, which can happen
1814 				 * only if we have control to send, then
1815 				 * a single empty mbuf is returned.  This
1816 				 * is a workaround to prevent protocol send
1817 				 * methods to panic.
1818 				 */
1819 #ifdef KERN_TLS
1820 				if (tls != NULL) {
1821 					top = m_uiotombuf(uio, M_WAITOK, space,
1822 					    tls->params.max_frame_len,
1823 					    M_EXTPG |
1824 					    ((flags & MSG_EOR) ? M_EOR : 0));
1825 					if (top != NULL) {
1826 						ktls_frame(top, tls,
1827 						    &tls_enq_cnt, tls_rtype);
1828 					}
1829 					tls_rtype = TLS_RLTYPE_APP;
1830 				} else
1831 #endif
1832 					top = m_uiotombuf(uio, M_WAITOK, space,
1833 					    (atomic ? max_hdr : 0),
1834 					    (atomic ? M_PKTHDR : 0) |
1835 					    ((flags & MSG_EOR) ? M_EOR : 0));
1836 				if (top == NULL) {
1837 					error = EFAULT; /* only possible error */
1838 					goto release;
1839 				}
1840 				space -= resid - uio->uio_resid;
1841 				resid = uio->uio_resid;
1842 			}
1843 			if (dontroute) {
1844 				SOCK_LOCK(so);
1845 				so->so_options |= SO_DONTROUTE;
1846 				SOCK_UNLOCK(so);
1847 			}
1848 			/*
1849 			 * XXX all the SBS_CANTSENDMORE checks previously
1850 			 * done could be out of date.  We could have received
1851 			 * a reset packet in an interrupt or maybe we slept
1852 			 * while doing page faults in uiomove() etc.  We
1853 			 * could probably recheck again inside the locking
1854 			 * protection here, but there are probably other
1855 			 * places that this also happens.  We must rethink
1856 			 * this.
1857 			 */
1858 			VNET_SO_ASSERT(so);
1859 
1860 			pr_send_flag = (flags & MSG_OOB) ? PRUS_OOB :
1861 			/*
1862 			 * If the user set MSG_EOF, the protocol understands
1863 			 * this flag and nothing left to send then use
1864 			 * PRU_SEND_EOF instead of PRU_SEND.
1865 			 */
1866 			    ((flags & MSG_EOF) &&
1867 			     (so->so_proto->pr_flags & PR_IMPLOPCL) &&
1868 			     (resid <= 0)) ?
1869 				PRUS_EOF :
1870 			/* If there is more to send set PRUS_MORETOCOME. */
1871 			    (flags & MSG_MORETOCOME) ||
1872 			    (resid > 0 && space > 0) ? PRUS_MORETOCOME : 0;
1873 
1874 #ifdef KERN_TLS
1875 			pr_send_flag |= tls_send_flag;
1876 #endif
1877 
1878 			error = so->so_proto->pr_send(so, pr_send_flag, top,
1879 			    addr, control, td);
1880 
1881 			if (dontroute) {
1882 				SOCK_LOCK(so);
1883 				so->so_options &= ~SO_DONTROUTE;
1884 				SOCK_UNLOCK(so);
1885 			}
1886 
1887 #ifdef KERN_TLS
1888 			if (tls != NULL && tls->mode == TCP_TLS_MODE_SW) {
1889 				if (error != 0) {
1890 					m_freem(top);
1891 					top = NULL;
1892 				} else {
1893 					soref(so);
1894 					ktls_enqueue(top, so, tls_enq_cnt);
1895 				}
1896 			}
1897 #endif
1898 			clen = 0;
1899 			control = NULL;
1900 			top = NULL;
1901 			if (error)
1902 				goto release;
1903 		} while (resid && space > 0);
1904 	} while (resid);
1905 
1906 release:
1907 	SOCK_IO_SEND_UNLOCK(so);
1908 out:
1909 #ifdef KERN_TLS
1910 	if (tls != NULL)
1911 		ktls_free(tls);
1912 #endif
1913 	if (top != NULL)
1914 		m_freem(top);
1915 	if (control != NULL)
1916 		m_freem(control);
1917 	return (error);
1918 }
1919 
1920 /*
1921  * Send to a socket from a kernel thread.
1922  *
1923  * XXXGL: in almost all cases uio is NULL and the mbuf is supplied.
1924  * Exception is nfs/bootp_subr.c.  It is arguable that the VNET context needs
1925  * to be set at all.  This function should just boil down to a static inline
1926  * calling the protocol method.
1927  */
1928 int
1929 sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
1930     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
1931 {
1932 	int error;
1933 
1934 	CURVNET_SET(so->so_vnet);
1935 	error = so->so_proto->pr_sosend(so, addr, uio,
1936 	    top, control, flags, td);
1937 	CURVNET_RESTORE();
1938 	return (error);
1939 }
1940 
1941 /*
1942  * send(2), write(2) or aio_write(2) on a socket.
1943  */
1944 int
1945 sousrsend(struct socket *so, struct sockaddr *addr, struct uio *uio,
1946     struct mbuf *control, int flags, struct proc *userproc)
1947 {
1948 	struct thread *td;
1949 	ssize_t len;
1950 	int error;
1951 
1952 	td = uio->uio_td;
1953 	len = uio->uio_resid;
1954 	CURVNET_SET(so->so_vnet);
1955 	error = so->so_proto->pr_sosend(so, addr, uio, NULL, control, flags,
1956 	    td);
1957 	CURVNET_RESTORE();
1958 	if (error != 0) {
1959 		/*
1960 		 * Clear transient errors for stream protocols if they made
1961 		 * some progress.  Make exclusion for aio(4) that would
1962 		 * schedule a new write in case of EWOULDBLOCK and clear
1963 		 * error itself.  See soaio_process_job().
1964 		 */
1965 		if (uio->uio_resid != len &&
1966 		    (so->so_proto->pr_flags & PR_ATOMIC) == 0 &&
1967 		    userproc == NULL &&
1968 		    (error == ERESTART || error == EINTR ||
1969 		    error == EWOULDBLOCK))
1970 			error = 0;
1971 		/* Generation of SIGPIPE can be controlled per socket. */
1972 		if (error == EPIPE && (so->so_options & SO_NOSIGPIPE) == 0 &&
1973 		    (flags & MSG_NOSIGNAL) == 0) {
1974 			if (userproc != NULL) {
1975 				/* aio(4) job */
1976 				PROC_LOCK(userproc);
1977 				kern_psignal(userproc, SIGPIPE);
1978 				PROC_UNLOCK(userproc);
1979 			} else {
1980 				PROC_LOCK(td->td_proc);
1981 				tdsignal(td, SIGPIPE);
1982 				PROC_UNLOCK(td->td_proc);
1983 			}
1984 		}
1985 	}
1986 	return (error);
1987 }
1988 
1989 /*
1990  * The part of soreceive() that implements reading non-inline out-of-band
1991  * data from a socket.  For more complete comments, see soreceive(), from
1992  * which this code originated.
1993  *
1994  * Note that soreceive_rcvoob(), unlike the remainder of soreceive(), is
1995  * unable to return an mbuf chain to the caller.
1996  */
1997 static int
1998 soreceive_rcvoob(struct socket *so, struct uio *uio, int flags)
1999 {
2000 	struct protosw *pr = so->so_proto;
2001 	struct mbuf *m;
2002 	int error;
2003 
2004 	KASSERT(flags & MSG_OOB, ("soreceive_rcvoob: (flags & MSG_OOB) == 0"));
2005 	VNET_SO_ASSERT(so);
2006 
2007 	m = m_get(M_WAITOK, MT_DATA);
2008 	error = pr->pr_rcvoob(so, m, flags & MSG_PEEK);
2009 	if (error)
2010 		goto bad;
2011 	do {
2012 		error = uiomove(mtod(m, void *),
2013 		    (int) min(uio->uio_resid, m->m_len), uio);
2014 		m = m_free(m);
2015 	} while (uio->uio_resid && error == 0 && m);
2016 bad:
2017 	if (m != NULL)
2018 		m_freem(m);
2019 	return (error);
2020 }
2021 
2022 /*
2023  * Following replacement or removal of the first mbuf on the first mbuf chain
2024  * of a socket buffer, push necessary state changes back into the socket
2025  * buffer so that other consumers see the values consistently.  'nextrecord'
2026  * is the callers locally stored value of the original value of
2027  * sb->sb_mb->m_nextpkt which must be restored when the lead mbuf changes.
2028  * NOTE: 'nextrecord' may be NULL.
2029  */
2030 static __inline void
2031 sockbuf_pushsync(struct sockbuf *sb, struct mbuf *nextrecord)
2032 {
2033 
2034 	SOCKBUF_LOCK_ASSERT(sb);
2035 	/*
2036 	 * First, update for the new value of nextrecord.  If necessary, make
2037 	 * it the first record.
2038 	 */
2039 	if (sb->sb_mb != NULL)
2040 		sb->sb_mb->m_nextpkt = nextrecord;
2041 	else
2042 		sb->sb_mb = nextrecord;
2043 
2044 	/*
2045 	 * Now update any dependent socket buffer fields to reflect the new
2046 	 * state.  This is an expanded inline of SB_EMPTY_FIXUP(), with the
2047 	 * addition of a second clause that takes care of the case where
2048 	 * sb_mb has been updated, but remains the last record.
2049 	 */
2050 	if (sb->sb_mb == NULL) {
2051 		sb->sb_mbtail = NULL;
2052 		sb->sb_lastrecord = NULL;
2053 	} else if (sb->sb_mb->m_nextpkt == NULL)
2054 		sb->sb_lastrecord = sb->sb_mb;
2055 }
2056 
2057 /*
2058  * Implement receive operations on a socket.  We depend on the way that
2059  * records are added to the sockbuf by sbappend.  In particular, each record
2060  * (mbufs linked through m_next) must begin with an address if the protocol
2061  * so specifies, followed by an optional mbuf or mbufs containing ancillary
2062  * data, and then zero or more mbufs of data.  In order to allow parallelism
2063  * between network receive and copying to user space, as well as avoid
2064  * sleeping with a mutex held, we release the socket buffer mutex during the
2065  * user space copy.  Although the sockbuf is locked, new data may still be
2066  * appended, and thus we must maintain consistency of the sockbuf during that
2067  * time.
2068  *
2069  * The caller may receive the data as a single mbuf chain by supplying an
2070  * mbuf **mp0 for use in returning the chain.  The uio is then used only for
2071  * the count in uio_resid.
2072  */
2073 int
2074 soreceive_generic(struct socket *so, struct sockaddr **psa, struct uio *uio,
2075     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2076 {
2077 	struct mbuf *m, **mp;
2078 	int flags, error, offset;
2079 	ssize_t len;
2080 	struct protosw *pr = so->so_proto;
2081 	struct mbuf *nextrecord;
2082 	int moff, type = 0;
2083 	ssize_t orig_resid = uio->uio_resid;
2084 	bool report_real_len = false;
2085 
2086 	mp = mp0;
2087 	if (psa != NULL)
2088 		*psa = NULL;
2089 	if (controlp != NULL)
2090 		*controlp = NULL;
2091 	if (flagsp != NULL) {
2092 		report_real_len = *flagsp & MSG_TRUNC;
2093 		*flagsp &= ~MSG_TRUNC;
2094 		flags = *flagsp &~ MSG_EOR;
2095 	} else
2096 		flags = 0;
2097 	if (flags & MSG_OOB)
2098 		return (soreceive_rcvoob(so, uio, flags));
2099 	if (mp != NULL)
2100 		*mp = NULL;
2101 
2102 	error = SOCK_IO_RECV_LOCK(so, SBLOCKWAIT(flags));
2103 	if (error)
2104 		return (error);
2105 
2106 restart:
2107 	SOCKBUF_LOCK(&so->so_rcv);
2108 	m = so->so_rcv.sb_mb;
2109 	/*
2110 	 * If we have less data than requested, block awaiting more (subject
2111 	 * to any timeout) if:
2112 	 *   1. the current count is less than the low water mark, or
2113 	 *   2. MSG_DONTWAIT is not set
2114 	 */
2115 	if (m == NULL || (((flags & MSG_DONTWAIT) == 0 &&
2116 	    sbavail(&so->so_rcv) < uio->uio_resid) &&
2117 	    sbavail(&so->so_rcv) < so->so_rcv.sb_lowat &&
2118 	    m->m_nextpkt == NULL && (pr->pr_flags & PR_ATOMIC) == 0)) {
2119 		KASSERT(m != NULL || !sbavail(&so->so_rcv),
2120 		    ("receive: m == %p sbavail == %u",
2121 		    m, sbavail(&so->so_rcv)));
2122 		if (so->so_error || so->so_rerror) {
2123 			if (m != NULL)
2124 				goto dontblock;
2125 			if (so->so_error)
2126 				error = so->so_error;
2127 			else
2128 				error = so->so_rerror;
2129 			if ((flags & MSG_PEEK) == 0) {
2130 				if (so->so_error)
2131 					so->so_error = 0;
2132 				else
2133 					so->so_rerror = 0;
2134 			}
2135 			SOCKBUF_UNLOCK(&so->so_rcv);
2136 			goto release;
2137 		}
2138 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2139 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
2140 			if (m != NULL)
2141 				goto dontblock;
2142 #ifdef KERN_TLS
2143 			else if (so->so_rcv.sb_tlsdcc == 0 &&
2144 			    so->so_rcv.sb_tlscc == 0) {
2145 #else
2146 			else {
2147 #endif
2148 				SOCKBUF_UNLOCK(&so->so_rcv);
2149 				goto release;
2150 			}
2151 		}
2152 		for (; m != NULL; m = m->m_next)
2153 			if (m->m_type == MT_OOBDATA  || (m->m_flags & M_EOR)) {
2154 				m = so->so_rcv.sb_mb;
2155 				goto dontblock;
2156 			}
2157 		if ((so->so_state & (SS_ISCONNECTING | SS_ISCONNECTED |
2158 		    SS_ISDISCONNECTING | SS_ISDISCONNECTED)) == 0 &&
2159 		    (so->so_proto->pr_flags & PR_CONNREQUIRED) != 0) {
2160 			SOCKBUF_UNLOCK(&so->so_rcv);
2161 			error = ENOTCONN;
2162 			goto release;
2163 		}
2164 		if (uio->uio_resid == 0 && !report_real_len) {
2165 			SOCKBUF_UNLOCK(&so->so_rcv);
2166 			goto release;
2167 		}
2168 		if ((so->so_state & SS_NBIO) ||
2169 		    (flags & (MSG_DONTWAIT|MSG_NBIO))) {
2170 			SOCKBUF_UNLOCK(&so->so_rcv);
2171 			error = EWOULDBLOCK;
2172 			goto release;
2173 		}
2174 		SBLASTRECORDCHK(&so->so_rcv);
2175 		SBLASTMBUFCHK(&so->so_rcv);
2176 		error = sbwait(so, SO_RCV);
2177 		SOCKBUF_UNLOCK(&so->so_rcv);
2178 		if (error)
2179 			goto release;
2180 		goto restart;
2181 	}
2182 dontblock:
2183 	/*
2184 	 * From this point onward, we maintain 'nextrecord' as a cache of the
2185 	 * pointer to the next record in the socket buffer.  We must keep the
2186 	 * various socket buffer pointers and local stack versions of the
2187 	 * pointers in sync, pushing out modifications before dropping the
2188 	 * socket buffer mutex, and re-reading them when picking it up.
2189 	 *
2190 	 * Otherwise, we will race with the network stack appending new data
2191 	 * or records onto the socket buffer by using inconsistent/stale
2192 	 * versions of the field, possibly resulting in socket buffer
2193 	 * corruption.
2194 	 *
2195 	 * By holding the high-level sblock(), we prevent simultaneous
2196 	 * readers from pulling off the front of the socket buffer.
2197 	 */
2198 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2199 	if (uio->uio_td)
2200 		uio->uio_td->td_ru.ru_msgrcv++;
2201 	KASSERT(m == so->so_rcv.sb_mb, ("soreceive: m != so->so_rcv.sb_mb"));
2202 	SBLASTRECORDCHK(&so->so_rcv);
2203 	SBLASTMBUFCHK(&so->so_rcv);
2204 	nextrecord = m->m_nextpkt;
2205 	if (pr->pr_flags & PR_ADDR) {
2206 		KASSERT(m->m_type == MT_SONAME,
2207 		    ("m->m_type == %d", m->m_type));
2208 		orig_resid = 0;
2209 		if (psa != NULL)
2210 			*psa = sodupsockaddr(mtod(m, struct sockaddr *),
2211 			    M_NOWAIT);
2212 		if (flags & MSG_PEEK) {
2213 			m = m->m_next;
2214 		} else {
2215 			sbfree(&so->so_rcv, m);
2216 			so->so_rcv.sb_mb = m_free(m);
2217 			m = so->so_rcv.sb_mb;
2218 			sockbuf_pushsync(&so->so_rcv, nextrecord);
2219 		}
2220 	}
2221 
2222 	/*
2223 	 * Process one or more MT_CONTROL mbufs present before any data mbufs
2224 	 * in the first mbuf chain on the socket buffer.  If MSG_PEEK, we
2225 	 * just copy the data; if !MSG_PEEK, we call into the protocol to
2226 	 * perform externalization (or freeing if controlp == NULL).
2227 	 */
2228 	if (m != NULL && m->m_type == MT_CONTROL) {
2229 		struct mbuf *cm = NULL, *cmn;
2230 		struct mbuf **cme = &cm;
2231 #ifdef KERN_TLS
2232 		struct cmsghdr *cmsg;
2233 		struct tls_get_record tgr;
2234 
2235 		/*
2236 		 * For MSG_TLSAPPDATA, check for an alert record.
2237 		 * If found, return ENXIO without removing
2238 		 * it from the receive queue.  This allows a subsequent
2239 		 * call without MSG_TLSAPPDATA to receive it.
2240 		 * Note that, for TLS, there should only be a single
2241 		 * control mbuf with the TLS_GET_RECORD message in it.
2242 		 */
2243 		if (flags & MSG_TLSAPPDATA) {
2244 			cmsg = mtod(m, struct cmsghdr *);
2245 			if (cmsg->cmsg_type == TLS_GET_RECORD &&
2246 			    cmsg->cmsg_len == CMSG_LEN(sizeof(tgr))) {
2247 				memcpy(&tgr, CMSG_DATA(cmsg), sizeof(tgr));
2248 				if (__predict_false(tgr.tls_type ==
2249 				    TLS_RLTYPE_ALERT)) {
2250 					SOCKBUF_UNLOCK(&so->so_rcv);
2251 					error = ENXIO;
2252 					goto release;
2253 				}
2254 			}
2255 		}
2256 #endif
2257 
2258 		do {
2259 			if (flags & MSG_PEEK) {
2260 				if (controlp != NULL) {
2261 					*controlp = m_copym(m, 0, m->m_len,
2262 					    M_NOWAIT);
2263 					controlp = &(*controlp)->m_next;
2264 				}
2265 				m = m->m_next;
2266 			} else {
2267 				sbfree(&so->so_rcv, m);
2268 				so->so_rcv.sb_mb = m->m_next;
2269 				m->m_next = NULL;
2270 				*cme = m;
2271 				cme = &(*cme)->m_next;
2272 				m = so->so_rcv.sb_mb;
2273 			}
2274 		} while (m != NULL && m->m_type == MT_CONTROL);
2275 		if ((flags & MSG_PEEK) == 0)
2276 			sockbuf_pushsync(&so->so_rcv, nextrecord);
2277 		while (cm != NULL) {
2278 			cmn = cm->m_next;
2279 			cm->m_next = NULL;
2280 			if (pr->pr_domain->dom_externalize != NULL) {
2281 				SOCKBUF_UNLOCK(&so->so_rcv);
2282 				VNET_SO_ASSERT(so);
2283 				error = (*pr->pr_domain->dom_externalize)
2284 				    (cm, controlp, flags);
2285 				SOCKBUF_LOCK(&so->so_rcv);
2286 			} else if (controlp != NULL)
2287 				*controlp = cm;
2288 			else
2289 				m_freem(cm);
2290 			if (controlp != NULL) {
2291 				while (*controlp != NULL)
2292 					controlp = &(*controlp)->m_next;
2293 			}
2294 			cm = cmn;
2295 		}
2296 		if (m != NULL)
2297 			nextrecord = so->so_rcv.sb_mb->m_nextpkt;
2298 		else
2299 			nextrecord = so->so_rcv.sb_mb;
2300 		orig_resid = 0;
2301 	}
2302 	if (m != NULL) {
2303 		if ((flags & MSG_PEEK) == 0) {
2304 			KASSERT(m->m_nextpkt == nextrecord,
2305 			    ("soreceive: post-control, nextrecord !sync"));
2306 			if (nextrecord == NULL) {
2307 				KASSERT(so->so_rcv.sb_mb == m,
2308 				    ("soreceive: post-control, sb_mb!=m"));
2309 				KASSERT(so->so_rcv.sb_lastrecord == m,
2310 				    ("soreceive: post-control, lastrecord!=m"));
2311 			}
2312 		}
2313 		type = m->m_type;
2314 		if (type == MT_OOBDATA)
2315 			flags |= MSG_OOB;
2316 	} else {
2317 		if ((flags & MSG_PEEK) == 0) {
2318 			KASSERT(so->so_rcv.sb_mb == nextrecord,
2319 			    ("soreceive: sb_mb != nextrecord"));
2320 			if (so->so_rcv.sb_mb == NULL) {
2321 				KASSERT(so->so_rcv.sb_lastrecord == NULL,
2322 				    ("soreceive: sb_lastercord != NULL"));
2323 			}
2324 		}
2325 	}
2326 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2327 	SBLASTRECORDCHK(&so->so_rcv);
2328 	SBLASTMBUFCHK(&so->so_rcv);
2329 
2330 	/*
2331 	 * Now continue to read any data mbufs off of the head of the socket
2332 	 * buffer until the read request is satisfied.  Note that 'type' is
2333 	 * used to store the type of any mbuf reads that have happened so far
2334 	 * such that soreceive() can stop reading if the type changes, which
2335 	 * causes soreceive() to return only one of regular data and inline
2336 	 * out-of-band data in a single socket receive operation.
2337 	 */
2338 	moff = 0;
2339 	offset = 0;
2340 	while (m != NULL && !(m->m_flags & M_NOTAVAIL) && uio->uio_resid > 0
2341 	    && error == 0) {
2342 		/*
2343 		 * If the type of mbuf has changed since the last mbuf
2344 		 * examined ('type'), end the receive operation.
2345 		 */
2346 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2347 		if (m->m_type == MT_OOBDATA || m->m_type == MT_CONTROL) {
2348 			if (type != m->m_type)
2349 				break;
2350 		} else if (type == MT_OOBDATA)
2351 			break;
2352 		else
2353 		    KASSERT(m->m_type == MT_DATA,
2354 			("m->m_type == %d", m->m_type));
2355 		so->so_rcv.sb_state &= ~SBS_RCVATMARK;
2356 		len = uio->uio_resid;
2357 		if (so->so_oobmark && len > so->so_oobmark - offset)
2358 			len = so->so_oobmark - offset;
2359 		if (len > m->m_len - moff)
2360 			len = m->m_len - moff;
2361 		/*
2362 		 * If mp is set, just pass back the mbufs.  Otherwise copy
2363 		 * them out via the uio, then free.  Sockbuf must be
2364 		 * consistent here (points to current mbuf, it points to next
2365 		 * record) when we drop priority; we must note any additions
2366 		 * to the sockbuf when we block interrupts again.
2367 		 */
2368 		if (mp == NULL) {
2369 			SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2370 			SBLASTRECORDCHK(&so->so_rcv);
2371 			SBLASTMBUFCHK(&so->so_rcv);
2372 			SOCKBUF_UNLOCK(&so->so_rcv);
2373 			if ((m->m_flags & M_EXTPG) != 0)
2374 				error = m_unmapped_uiomove(m, moff, uio,
2375 				    (int)len);
2376 			else
2377 				error = uiomove(mtod(m, char *) + moff,
2378 				    (int)len, uio);
2379 			SOCKBUF_LOCK(&so->so_rcv);
2380 			if (error) {
2381 				/*
2382 				 * The MT_SONAME mbuf has already been removed
2383 				 * from the record, so it is necessary to
2384 				 * remove the data mbufs, if any, to preserve
2385 				 * the invariant in the case of PR_ADDR that
2386 				 * requires MT_SONAME mbufs at the head of
2387 				 * each record.
2388 				 */
2389 				if (pr->pr_flags & PR_ATOMIC &&
2390 				    ((flags & MSG_PEEK) == 0))
2391 					(void)sbdroprecord_locked(&so->so_rcv);
2392 				SOCKBUF_UNLOCK(&so->so_rcv);
2393 				goto release;
2394 			}
2395 		} else
2396 			uio->uio_resid -= len;
2397 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2398 		if (len == m->m_len - moff) {
2399 			if (m->m_flags & M_EOR)
2400 				flags |= MSG_EOR;
2401 			if (flags & MSG_PEEK) {
2402 				m = m->m_next;
2403 				moff = 0;
2404 			} else {
2405 				nextrecord = m->m_nextpkt;
2406 				sbfree(&so->so_rcv, m);
2407 				if (mp != NULL) {
2408 					m->m_nextpkt = NULL;
2409 					*mp = m;
2410 					mp = &m->m_next;
2411 					so->so_rcv.sb_mb = m = m->m_next;
2412 					*mp = NULL;
2413 				} else {
2414 					so->so_rcv.sb_mb = m_free(m);
2415 					m = so->so_rcv.sb_mb;
2416 				}
2417 				sockbuf_pushsync(&so->so_rcv, nextrecord);
2418 				SBLASTRECORDCHK(&so->so_rcv);
2419 				SBLASTMBUFCHK(&so->so_rcv);
2420 			}
2421 		} else {
2422 			if (flags & MSG_PEEK)
2423 				moff += len;
2424 			else {
2425 				if (mp != NULL) {
2426 					if (flags & MSG_DONTWAIT) {
2427 						*mp = m_copym(m, 0, len,
2428 						    M_NOWAIT);
2429 						if (*mp == NULL) {
2430 							/*
2431 							 * m_copym() couldn't
2432 							 * allocate an mbuf.
2433 							 * Adjust uio_resid back
2434 							 * (it was adjusted
2435 							 * down by len bytes,
2436 							 * which we didn't end
2437 							 * up "copying" over).
2438 							 */
2439 							uio->uio_resid += len;
2440 							break;
2441 						}
2442 					} else {
2443 						SOCKBUF_UNLOCK(&so->so_rcv);
2444 						*mp = m_copym(m, 0, len,
2445 						    M_WAITOK);
2446 						SOCKBUF_LOCK(&so->so_rcv);
2447 					}
2448 				}
2449 				sbcut_locked(&so->so_rcv, len);
2450 			}
2451 		}
2452 		SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2453 		if (so->so_oobmark) {
2454 			if ((flags & MSG_PEEK) == 0) {
2455 				so->so_oobmark -= len;
2456 				if (so->so_oobmark == 0) {
2457 					so->so_rcv.sb_state |= SBS_RCVATMARK;
2458 					break;
2459 				}
2460 			} else {
2461 				offset += len;
2462 				if (offset == so->so_oobmark)
2463 					break;
2464 			}
2465 		}
2466 		if (flags & MSG_EOR)
2467 			break;
2468 		/*
2469 		 * If the MSG_WAITALL flag is set (for non-atomic socket), we
2470 		 * must not quit until "uio->uio_resid == 0" or an error
2471 		 * termination.  If a signal/timeout occurs, return with a
2472 		 * short count but without error.  Keep sockbuf locked
2473 		 * against other readers.
2474 		 */
2475 		while (flags & MSG_WAITALL && m == NULL && uio->uio_resid > 0 &&
2476 		    !sosendallatonce(so) && nextrecord == NULL) {
2477 			SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2478 			if (so->so_error || so->so_rerror ||
2479 			    so->so_rcv.sb_state & SBS_CANTRCVMORE)
2480 				break;
2481 			/*
2482 			 * Notify the protocol that some data has been
2483 			 * drained before blocking.
2484 			 */
2485 			if (pr->pr_flags & PR_WANTRCVD) {
2486 				SOCKBUF_UNLOCK(&so->so_rcv);
2487 				VNET_SO_ASSERT(so);
2488 				pr->pr_rcvd(so, flags);
2489 				SOCKBUF_LOCK(&so->so_rcv);
2490 				if (__predict_false(so->so_rcv.sb_mb == NULL &&
2491 				    (so->so_error || so->so_rerror ||
2492 				    so->so_rcv.sb_state & SBS_CANTRCVMORE)))
2493 					break;
2494 			}
2495 			SBLASTRECORDCHK(&so->so_rcv);
2496 			SBLASTMBUFCHK(&so->so_rcv);
2497 			/*
2498 			 * We could receive some data while was notifying
2499 			 * the protocol. Skip blocking in this case.
2500 			 */
2501 			if (so->so_rcv.sb_mb == NULL) {
2502 				error = sbwait(so, SO_RCV);
2503 				if (error) {
2504 					SOCKBUF_UNLOCK(&so->so_rcv);
2505 					goto release;
2506 				}
2507 			}
2508 			m = so->so_rcv.sb_mb;
2509 			if (m != NULL)
2510 				nextrecord = m->m_nextpkt;
2511 		}
2512 	}
2513 
2514 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2515 	if (m != NULL && pr->pr_flags & PR_ATOMIC) {
2516 		if (report_real_len)
2517 			uio->uio_resid -= m_length(m, NULL) - moff;
2518 		flags |= MSG_TRUNC;
2519 		if ((flags & MSG_PEEK) == 0)
2520 			(void) sbdroprecord_locked(&so->so_rcv);
2521 	}
2522 	if ((flags & MSG_PEEK) == 0) {
2523 		if (m == NULL) {
2524 			/*
2525 			 * First part is an inline SB_EMPTY_FIXUP().  Second
2526 			 * part makes sure sb_lastrecord is up-to-date if
2527 			 * there is still data in the socket buffer.
2528 			 */
2529 			so->so_rcv.sb_mb = nextrecord;
2530 			if (so->so_rcv.sb_mb == NULL) {
2531 				so->so_rcv.sb_mbtail = NULL;
2532 				so->so_rcv.sb_lastrecord = NULL;
2533 			} else if (nextrecord->m_nextpkt == NULL)
2534 				so->so_rcv.sb_lastrecord = nextrecord;
2535 		}
2536 		SBLASTRECORDCHK(&so->so_rcv);
2537 		SBLASTMBUFCHK(&so->so_rcv);
2538 		/*
2539 		 * If soreceive() is being done from the socket callback,
2540 		 * then don't need to generate ACK to peer to update window,
2541 		 * since ACK will be generated on return to TCP.
2542 		 */
2543 		if (!(flags & MSG_SOCALLBCK) &&
2544 		    (pr->pr_flags & PR_WANTRCVD)) {
2545 			SOCKBUF_UNLOCK(&so->so_rcv);
2546 			VNET_SO_ASSERT(so);
2547 			pr->pr_rcvd(so, flags);
2548 			SOCKBUF_LOCK(&so->so_rcv);
2549 		}
2550 	}
2551 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2552 	if (orig_resid == uio->uio_resid && orig_resid &&
2553 	    (flags & MSG_EOR) == 0 && (so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0) {
2554 		SOCKBUF_UNLOCK(&so->so_rcv);
2555 		goto restart;
2556 	}
2557 	SOCKBUF_UNLOCK(&so->so_rcv);
2558 
2559 	if (flagsp != NULL)
2560 		*flagsp |= flags;
2561 release:
2562 	SOCK_IO_RECV_UNLOCK(so);
2563 	return (error);
2564 }
2565 
2566 /*
2567  * Optimized version of soreceive() for stream (TCP) sockets.
2568  */
2569 int
2570 soreceive_stream(struct socket *so, struct sockaddr **psa, struct uio *uio,
2571     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2572 {
2573 	int len = 0, error = 0, flags, oresid;
2574 	struct sockbuf *sb;
2575 	struct mbuf *m, *n = NULL;
2576 
2577 	/* We only do stream sockets. */
2578 	if (so->so_type != SOCK_STREAM)
2579 		return (EINVAL);
2580 	if (psa != NULL)
2581 		*psa = NULL;
2582 	if (flagsp != NULL)
2583 		flags = *flagsp &~ MSG_EOR;
2584 	else
2585 		flags = 0;
2586 	if (controlp != NULL)
2587 		*controlp = NULL;
2588 	if (flags & MSG_OOB)
2589 		return (soreceive_rcvoob(so, uio, flags));
2590 	if (mp0 != NULL)
2591 		*mp0 = NULL;
2592 
2593 	sb = &so->so_rcv;
2594 
2595 #ifdef KERN_TLS
2596 	/*
2597 	 * KTLS store TLS records as records with a control message to
2598 	 * describe the framing.
2599 	 *
2600 	 * We check once here before acquiring locks to optimize the
2601 	 * common case.
2602 	 */
2603 	if (sb->sb_tls_info != NULL)
2604 		return (soreceive_generic(so, psa, uio, mp0, controlp,
2605 		    flagsp));
2606 #endif
2607 
2608 	/* Prevent other readers from entering the socket. */
2609 	error = SOCK_IO_RECV_LOCK(so, SBLOCKWAIT(flags));
2610 	if (error)
2611 		return (error);
2612 #ifdef KERN_TLS
2613 	if (__predict_false(sb->sb_tls_info != NULL)) {
2614 		SOCK_IO_RECV_UNLOCK(so);
2615 		return (soreceive_generic(so, psa, uio, mp0, controlp,
2616 		    flagsp));
2617 	}
2618 #endif
2619 
2620 	SOCKBUF_LOCK(sb);
2621 	/* Easy one, no space to copyout anything. */
2622 	if (uio->uio_resid == 0) {
2623 		error = EINVAL;
2624 		goto out;
2625 	}
2626 	oresid = uio->uio_resid;
2627 
2628 	/* We will never ever get anything unless we are or were connected. */
2629 	if (!(so->so_state & (SS_ISCONNECTED|SS_ISDISCONNECTED))) {
2630 		error = ENOTCONN;
2631 		goto out;
2632 	}
2633 
2634 restart:
2635 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2636 
2637 	/* Abort if socket has reported problems. */
2638 	if (so->so_error) {
2639 		if (sbavail(sb) > 0)
2640 			goto deliver;
2641 		if (oresid > uio->uio_resid)
2642 			goto out;
2643 		error = so->so_error;
2644 		if (!(flags & MSG_PEEK))
2645 			so->so_error = 0;
2646 		goto out;
2647 	}
2648 
2649 	/* Door is closed.  Deliver what is left, if any. */
2650 	if (sb->sb_state & SBS_CANTRCVMORE) {
2651 		if (sbavail(sb) > 0)
2652 			goto deliver;
2653 		else
2654 			goto out;
2655 	}
2656 
2657 	/* Socket buffer is empty and we shall not block. */
2658 	if (sbavail(sb) == 0 &&
2659 	    ((so->so_state & SS_NBIO) || (flags & (MSG_DONTWAIT|MSG_NBIO)))) {
2660 		error = EAGAIN;
2661 		goto out;
2662 	}
2663 
2664 	/* Socket buffer got some data that we shall deliver now. */
2665 	if (sbavail(sb) > 0 && !(flags & MSG_WAITALL) &&
2666 	    ((so->so_state & SS_NBIO) ||
2667 	     (flags & (MSG_DONTWAIT|MSG_NBIO)) ||
2668 	     sbavail(sb) >= sb->sb_lowat ||
2669 	     sbavail(sb) >= uio->uio_resid ||
2670 	     sbavail(sb) >= sb->sb_hiwat) ) {
2671 		goto deliver;
2672 	}
2673 
2674 	/* On MSG_WAITALL we must wait until all data or error arrives. */
2675 	if ((flags & MSG_WAITALL) &&
2676 	    (sbavail(sb) >= uio->uio_resid || sbavail(sb) >= sb->sb_hiwat))
2677 		goto deliver;
2678 
2679 	/*
2680 	 * Wait and block until (more) data comes in.
2681 	 * NB: Drops the sockbuf lock during wait.
2682 	 */
2683 	error = sbwait(so, SO_RCV);
2684 	if (error)
2685 		goto out;
2686 	goto restart;
2687 
2688 deliver:
2689 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2690 	KASSERT(sbavail(sb) > 0, ("%s: sockbuf empty", __func__));
2691 	KASSERT(sb->sb_mb != NULL, ("%s: sb_mb == NULL", __func__));
2692 
2693 	/* Statistics. */
2694 	if (uio->uio_td)
2695 		uio->uio_td->td_ru.ru_msgrcv++;
2696 
2697 	/* Fill uio until full or current end of socket buffer is reached. */
2698 	len = min(uio->uio_resid, sbavail(sb));
2699 	if (mp0 != NULL) {
2700 		/* Dequeue as many mbufs as possible. */
2701 		if (!(flags & MSG_PEEK) && len >= sb->sb_mb->m_len) {
2702 			if (*mp0 == NULL)
2703 				*mp0 = sb->sb_mb;
2704 			else
2705 				m_cat(*mp0, sb->sb_mb);
2706 			for (m = sb->sb_mb;
2707 			     m != NULL && m->m_len <= len;
2708 			     m = m->m_next) {
2709 				KASSERT(!(m->m_flags & M_NOTAVAIL),
2710 				    ("%s: m %p not available", __func__, m));
2711 				len -= m->m_len;
2712 				uio->uio_resid -= m->m_len;
2713 				sbfree(sb, m);
2714 				n = m;
2715 			}
2716 			n->m_next = NULL;
2717 			sb->sb_mb = m;
2718 			sb->sb_lastrecord = sb->sb_mb;
2719 			if (sb->sb_mb == NULL)
2720 				SB_EMPTY_FIXUP(sb);
2721 		}
2722 		/* Copy the remainder. */
2723 		if (len > 0) {
2724 			KASSERT(sb->sb_mb != NULL,
2725 			    ("%s: len > 0 && sb->sb_mb empty", __func__));
2726 
2727 			m = m_copym(sb->sb_mb, 0, len, M_NOWAIT);
2728 			if (m == NULL)
2729 				len = 0;	/* Don't flush data from sockbuf. */
2730 			else
2731 				uio->uio_resid -= len;
2732 			if (*mp0 != NULL)
2733 				m_cat(*mp0, m);
2734 			else
2735 				*mp0 = m;
2736 			if (*mp0 == NULL) {
2737 				error = ENOBUFS;
2738 				goto out;
2739 			}
2740 		}
2741 	} else {
2742 		/* NB: Must unlock socket buffer as uiomove may sleep. */
2743 		SOCKBUF_UNLOCK(sb);
2744 		error = m_mbuftouio(uio, sb->sb_mb, len);
2745 		SOCKBUF_LOCK(sb);
2746 		if (error)
2747 			goto out;
2748 	}
2749 	SBLASTRECORDCHK(sb);
2750 	SBLASTMBUFCHK(sb);
2751 
2752 	/*
2753 	 * Remove the delivered data from the socket buffer unless we
2754 	 * were only peeking.
2755 	 */
2756 	if (!(flags & MSG_PEEK)) {
2757 		if (len > 0)
2758 			sbdrop_locked(sb, len);
2759 
2760 		/* Notify protocol that we drained some data. */
2761 		if ((so->so_proto->pr_flags & PR_WANTRCVD) &&
2762 		    (((flags & MSG_WAITALL) && uio->uio_resid > 0) ||
2763 		     !(flags & MSG_SOCALLBCK))) {
2764 			SOCKBUF_UNLOCK(sb);
2765 			VNET_SO_ASSERT(so);
2766 			so->so_proto->pr_rcvd(so, flags);
2767 			SOCKBUF_LOCK(sb);
2768 		}
2769 	}
2770 
2771 	/*
2772 	 * For MSG_WAITALL we may have to loop again and wait for
2773 	 * more data to come in.
2774 	 */
2775 	if ((flags & MSG_WAITALL) && uio->uio_resid > 0)
2776 		goto restart;
2777 out:
2778 	SBLASTRECORDCHK(sb);
2779 	SBLASTMBUFCHK(sb);
2780 	SOCKBUF_UNLOCK(sb);
2781 	SOCK_IO_RECV_UNLOCK(so);
2782 	return (error);
2783 }
2784 
2785 /*
2786  * Optimized version of soreceive() for simple datagram cases from userspace.
2787  * Unlike in the stream case, we're able to drop a datagram if copyout()
2788  * fails, and because we handle datagrams atomically, we don't need to use a
2789  * sleep lock to prevent I/O interlacing.
2790  */
2791 int
2792 soreceive_dgram(struct socket *so, struct sockaddr **psa, struct uio *uio,
2793     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2794 {
2795 	struct mbuf *m, *m2;
2796 	int flags, error;
2797 	ssize_t len;
2798 	struct protosw *pr = so->so_proto;
2799 	struct mbuf *nextrecord;
2800 
2801 	if (psa != NULL)
2802 		*psa = NULL;
2803 	if (controlp != NULL)
2804 		*controlp = NULL;
2805 	if (flagsp != NULL)
2806 		flags = *flagsp &~ MSG_EOR;
2807 	else
2808 		flags = 0;
2809 
2810 	/*
2811 	 * For any complicated cases, fall back to the full
2812 	 * soreceive_generic().
2813 	 */
2814 	if (mp0 != NULL || (flags & (MSG_PEEK | MSG_OOB | MSG_TRUNC)))
2815 		return (soreceive_generic(so, psa, uio, mp0, controlp,
2816 		    flagsp));
2817 
2818 	/*
2819 	 * Enforce restrictions on use.
2820 	 */
2821 	KASSERT((pr->pr_flags & PR_WANTRCVD) == 0,
2822 	    ("soreceive_dgram: wantrcvd"));
2823 	KASSERT(pr->pr_flags & PR_ATOMIC, ("soreceive_dgram: !atomic"));
2824 	KASSERT((so->so_rcv.sb_state & SBS_RCVATMARK) == 0,
2825 	    ("soreceive_dgram: SBS_RCVATMARK"));
2826 	KASSERT((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0,
2827 	    ("soreceive_dgram: P_CONNREQUIRED"));
2828 
2829 	/*
2830 	 * Loop blocking while waiting for a datagram.
2831 	 */
2832 	SOCKBUF_LOCK(&so->so_rcv);
2833 	while ((m = so->so_rcv.sb_mb) == NULL) {
2834 		KASSERT(sbavail(&so->so_rcv) == 0,
2835 		    ("soreceive_dgram: sb_mb NULL but sbavail %u",
2836 		    sbavail(&so->so_rcv)));
2837 		if (so->so_error) {
2838 			error = so->so_error;
2839 			so->so_error = 0;
2840 			SOCKBUF_UNLOCK(&so->so_rcv);
2841 			return (error);
2842 		}
2843 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE ||
2844 		    uio->uio_resid == 0) {
2845 			SOCKBUF_UNLOCK(&so->so_rcv);
2846 			return (0);
2847 		}
2848 		if ((so->so_state & SS_NBIO) ||
2849 		    (flags & (MSG_DONTWAIT|MSG_NBIO))) {
2850 			SOCKBUF_UNLOCK(&so->so_rcv);
2851 			return (EWOULDBLOCK);
2852 		}
2853 		SBLASTRECORDCHK(&so->so_rcv);
2854 		SBLASTMBUFCHK(&so->so_rcv);
2855 		error = sbwait(so, SO_RCV);
2856 		if (error) {
2857 			SOCKBUF_UNLOCK(&so->so_rcv);
2858 			return (error);
2859 		}
2860 	}
2861 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2862 
2863 	if (uio->uio_td)
2864 		uio->uio_td->td_ru.ru_msgrcv++;
2865 	SBLASTRECORDCHK(&so->so_rcv);
2866 	SBLASTMBUFCHK(&so->so_rcv);
2867 	nextrecord = m->m_nextpkt;
2868 	if (nextrecord == NULL) {
2869 		KASSERT(so->so_rcv.sb_lastrecord == m,
2870 		    ("soreceive_dgram: lastrecord != m"));
2871 	}
2872 
2873 	KASSERT(so->so_rcv.sb_mb->m_nextpkt == nextrecord,
2874 	    ("soreceive_dgram: m_nextpkt != nextrecord"));
2875 
2876 	/*
2877 	 * Pull 'm' and its chain off the front of the packet queue.
2878 	 */
2879 	so->so_rcv.sb_mb = NULL;
2880 	sockbuf_pushsync(&so->so_rcv, nextrecord);
2881 
2882 	/*
2883 	 * Walk 'm's chain and free that many bytes from the socket buffer.
2884 	 */
2885 	for (m2 = m; m2 != NULL; m2 = m2->m_next)
2886 		sbfree(&so->so_rcv, m2);
2887 
2888 	/*
2889 	 * Do a few last checks before we let go of the lock.
2890 	 */
2891 	SBLASTRECORDCHK(&so->so_rcv);
2892 	SBLASTMBUFCHK(&so->so_rcv);
2893 	SOCKBUF_UNLOCK(&so->so_rcv);
2894 
2895 	if (pr->pr_flags & PR_ADDR) {
2896 		KASSERT(m->m_type == MT_SONAME,
2897 		    ("m->m_type == %d", m->m_type));
2898 		if (psa != NULL)
2899 			*psa = sodupsockaddr(mtod(m, struct sockaddr *),
2900 			    M_WAITOK);
2901 		m = m_free(m);
2902 	}
2903 	KASSERT(m, ("%s: no data or control after soname", __func__));
2904 
2905 	/*
2906 	 * Packet to copyout() is now in 'm' and it is disconnected from the
2907 	 * queue.
2908 	 *
2909 	 * Process one or more MT_CONTROL mbufs present before any data mbufs
2910 	 * in the first mbuf chain on the socket buffer.  We call into the
2911 	 * protocol to perform externalization (or freeing if controlp ==
2912 	 * NULL). In some cases there can be only MT_CONTROL mbufs without
2913 	 * MT_DATA mbufs.
2914 	 */
2915 	if (m->m_type == MT_CONTROL) {
2916 		struct mbuf *cm = NULL, *cmn;
2917 		struct mbuf **cme = &cm;
2918 
2919 		do {
2920 			m2 = m->m_next;
2921 			m->m_next = NULL;
2922 			*cme = m;
2923 			cme = &(*cme)->m_next;
2924 			m = m2;
2925 		} while (m != NULL && m->m_type == MT_CONTROL);
2926 		while (cm != NULL) {
2927 			cmn = cm->m_next;
2928 			cm->m_next = NULL;
2929 			if (pr->pr_domain->dom_externalize != NULL) {
2930 				error = (*pr->pr_domain->dom_externalize)
2931 				    (cm, controlp, flags);
2932 			} else if (controlp != NULL)
2933 				*controlp = cm;
2934 			else
2935 				m_freem(cm);
2936 			if (controlp != NULL) {
2937 				while (*controlp != NULL)
2938 					controlp = &(*controlp)->m_next;
2939 			}
2940 			cm = cmn;
2941 		}
2942 	}
2943 	KASSERT(m == NULL || m->m_type == MT_DATA,
2944 	    ("soreceive_dgram: !data"));
2945 	while (m != NULL && uio->uio_resid > 0) {
2946 		len = uio->uio_resid;
2947 		if (len > m->m_len)
2948 			len = m->m_len;
2949 		error = uiomove(mtod(m, char *), (int)len, uio);
2950 		if (error) {
2951 			m_freem(m);
2952 			return (error);
2953 		}
2954 		if (len == m->m_len)
2955 			m = m_free(m);
2956 		else {
2957 			m->m_data += len;
2958 			m->m_len -= len;
2959 		}
2960 	}
2961 	if (m != NULL) {
2962 		flags |= MSG_TRUNC;
2963 		m_freem(m);
2964 	}
2965 	if (flagsp != NULL)
2966 		*flagsp |= flags;
2967 	return (0);
2968 }
2969 
2970 int
2971 soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
2972     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2973 {
2974 	int error;
2975 
2976 	CURVNET_SET(so->so_vnet);
2977 	error = so->so_proto->pr_soreceive(so, psa, uio, mp0, controlp, flagsp);
2978 	CURVNET_RESTORE();
2979 	return (error);
2980 }
2981 
2982 int
2983 soshutdown(struct socket *so, enum shutdown_how how)
2984 {
2985 	int error;
2986 
2987 	CURVNET_SET(so->so_vnet);
2988 	error = so->so_proto->pr_shutdown(so, how);
2989 	CURVNET_RESTORE();
2990 
2991 	return (error);
2992 }
2993 
2994 /*
2995  * Used by several pr_shutdown implementations that use generic socket buffers.
2996  */
2997 void
2998 sorflush(struct socket *so)
2999 {
3000 	int error;
3001 
3002 	VNET_SO_ASSERT(so);
3003 
3004 	/*
3005 	 * Dislodge threads currently blocked in receive and wait to acquire
3006 	 * a lock against other simultaneous readers before clearing the
3007 	 * socket buffer.  Don't let our acquire be interrupted by a signal
3008 	 * despite any existing socket disposition on interruptable waiting.
3009 	 *
3010 	 * The SOCK_IO_RECV_LOCK() is important here as there some pr_soreceive
3011 	 * methods that read the top of the socket buffer without acquisition
3012 	 * of the socket buffer mutex, assuming that top of the buffer
3013 	 * exclusively belongs to the read(2) syscall.  This is handy when
3014 	 * performing MSG_PEEK.
3015 	 */
3016 	socantrcvmore(so);
3017 
3018 	error = SOCK_IO_RECV_LOCK(so, SBL_WAIT | SBL_NOINTR);
3019 	if (error != 0) {
3020 		KASSERT(SOLISTENING(so),
3021 		    ("%s: soiolock(%p) failed", __func__, so));
3022 		return;
3023 	}
3024 
3025 	sbrelease(so, SO_RCV);
3026 	SOCK_IO_RECV_UNLOCK(so);
3027 
3028 }
3029 
3030 #ifdef SOCKET_HHOOK
3031 /*
3032  * Wrapper for Socket established helper hook.
3033  * Parameters: socket, context of the hook point, hook id.
3034  */
3035 static inline int
3036 hhook_run_socket(struct socket *so, void *hctx, int32_t h_id)
3037 {
3038 	struct socket_hhook_data hhook_data = {
3039 		.so = so,
3040 		.hctx = hctx,
3041 		.m = NULL,
3042 		.status = 0
3043 	};
3044 
3045 	CURVNET_SET(so->so_vnet);
3046 	HHOOKS_RUN_IF(V_socket_hhh[h_id], &hhook_data, &so->osd);
3047 	CURVNET_RESTORE();
3048 
3049 	/* Ugly but needed, since hhooks return void for now */
3050 	return (hhook_data.status);
3051 }
3052 #endif
3053 
3054 /*
3055  * Perhaps this routine, and sooptcopyout(), below, ought to come in an
3056  * additional variant to handle the case where the option value needs to be
3057  * some kind of integer, but not a specific size.  In addition to their use
3058  * here, these functions are also called by the protocol-level pr_ctloutput()
3059  * routines.
3060  */
3061 int
3062 sooptcopyin(struct sockopt *sopt, void *buf, size_t len, size_t minlen)
3063 {
3064 	size_t	valsize;
3065 
3066 	/*
3067 	 * If the user gives us more than we wanted, we ignore it, but if we
3068 	 * don't get the minimum length the caller wants, we return EINVAL.
3069 	 * On success, sopt->sopt_valsize is set to however much we actually
3070 	 * retrieved.
3071 	 */
3072 	if ((valsize = sopt->sopt_valsize) < minlen)
3073 		return EINVAL;
3074 	if (valsize > len)
3075 		sopt->sopt_valsize = valsize = len;
3076 
3077 	if (sopt->sopt_td != NULL)
3078 		return (copyin(sopt->sopt_val, buf, valsize));
3079 
3080 	bcopy(sopt->sopt_val, buf, valsize);
3081 	return (0);
3082 }
3083 
3084 /*
3085  * Kernel version of setsockopt(2).
3086  *
3087  * XXX: optlen is size_t, not socklen_t
3088  */
3089 int
3090 so_setsockopt(struct socket *so, int level, int optname, void *optval,
3091     size_t optlen)
3092 {
3093 	struct sockopt sopt;
3094 
3095 	sopt.sopt_level = level;
3096 	sopt.sopt_name = optname;
3097 	sopt.sopt_dir = SOPT_SET;
3098 	sopt.sopt_val = optval;
3099 	sopt.sopt_valsize = optlen;
3100 	sopt.sopt_td = NULL;
3101 	return (sosetopt(so, &sopt));
3102 }
3103 
3104 int
3105 sosetopt(struct socket *so, struct sockopt *sopt)
3106 {
3107 	int	error, optval;
3108 	struct	linger l;
3109 	struct	timeval tv;
3110 	sbintime_t val, *valp;
3111 	uint32_t val32;
3112 #ifdef MAC
3113 	struct mac extmac;
3114 #endif
3115 
3116 	CURVNET_SET(so->so_vnet);
3117 	error = 0;
3118 	if (sopt->sopt_level != SOL_SOCKET) {
3119 		if (so->so_proto->pr_ctloutput != NULL)
3120 			error = (*so->so_proto->pr_ctloutput)(so, sopt);
3121 		else
3122 			error = ENOPROTOOPT;
3123 	} else {
3124 		switch (sopt->sopt_name) {
3125 		case SO_ACCEPTFILTER:
3126 			error = accept_filt_setopt(so, sopt);
3127 			if (error)
3128 				goto bad;
3129 			break;
3130 
3131 		case SO_LINGER:
3132 			error = sooptcopyin(sopt, &l, sizeof l, sizeof l);
3133 			if (error)
3134 				goto bad;
3135 			if (l.l_linger < 0 ||
3136 			    l.l_linger > USHRT_MAX ||
3137 			    l.l_linger > (INT_MAX / hz)) {
3138 				error = EDOM;
3139 				goto bad;
3140 			}
3141 			SOCK_LOCK(so);
3142 			so->so_linger = l.l_linger;
3143 			if (l.l_onoff)
3144 				so->so_options |= SO_LINGER;
3145 			else
3146 				so->so_options &= ~SO_LINGER;
3147 			SOCK_UNLOCK(so);
3148 			break;
3149 
3150 		case SO_DEBUG:
3151 		case SO_KEEPALIVE:
3152 		case SO_DONTROUTE:
3153 		case SO_USELOOPBACK:
3154 		case SO_BROADCAST:
3155 		case SO_REUSEADDR:
3156 		case SO_REUSEPORT:
3157 		case SO_REUSEPORT_LB:
3158 		case SO_OOBINLINE:
3159 		case SO_TIMESTAMP:
3160 		case SO_BINTIME:
3161 		case SO_NOSIGPIPE:
3162 		case SO_NO_DDP:
3163 		case SO_NO_OFFLOAD:
3164 		case SO_RERROR:
3165 			error = sooptcopyin(sopt, &optval, sizeof optval,
3166 			    sizeof optval);
3167 			if (error)
3168 				goto bad;
3169 			SOCK_LOCK(so);
3170 			if (optval)
3171 				so->so_options |= sopt->sopt_name;
3172 			else
3173 				so->so_options &= ~sopt->sopt_name;
3174 			SOCK_UNLOCK(so);
3175 			break;
3176 
3177 		case SO_SETFIB:
3178 			error = sooptcopyin(sopt, &optval, sizeof optval,
3179 			    sizeof optval);
3180 			if (error)
3181 				goto bad;
3182 
3183 			if (optval < 0 || optval >= rt_numfibs) {
3184 				error = EINVAL;
3185 				goto bad;
3186 			}
3187 			if (((so->so_proto->pr_domain->dom_family == PF_INET) ||
3188 			   (so->so_proto->pr_domain->dom_family == PF_INET6) ||
3189 			   (so->so_proto->pr_domain->dom_family == PF_ROUTE)))
3190 				so->so_fibnum = optval;
3191 			else
3192 				so->so_fibnum = 0;
3193 			break;
3194 
3195 		case SO_USER_COOKIE:
3196 			error = sooptcopyin(sopt, &val32, sizeof val32,
3197 			    sizeof val32);
3198 			if (error)
3199 				goto bad;
3200 			so->so_user_cookie = val32;
3201 			break;
3202 
3203 		case SO_SNDBUF:
3204 		case SO_RCVBUF:
3205 		case SO_SNDLOWAT:
3206 		case SO_RCVLOWAT:
3207 			error = so->so_proto->pr_setsbopt(so, sopt);
3208 			if (error)
3209 				goto bad;
3210 			break;
3211 
3212 		case SO_SNDTIMEO:
3213 		case SO_RCVTIMEO:
3214 #ifdef COMPAT_FREEBSD32
3215 			if (SV_CURPROC_FLAG(SV_ILP32)) {
3216 				struct timeval32 tv32;
3217 
3218 				error = sooptcopyin(sopt, &tv32, sizeof tv32,
3219 				    sizeof tv32);
3220 				CP(tv32, tv, tv_sec);
3221 				CP(tv32, tv, tv_usec);
3222 			} else
3223 #endif
3224 				error = sooptcopyin(sopt, &tv, sizeof tv,
3225 				    sizeof tv);
3226 			if (error)
3227 				goto bad;
3228 			if (tv.tv_sec < 0 || tv.tv_usec < 0 ||
3229 			    tv.tv_usec >= 1000000) {
3230 				error = EDOM;
3231 				goto bad;
3232 			}
3233 			if (tv.tv_sec > INT32_MAX)
3234 				val = SBT_MAX;
3235 			else
3236 				val = tvtosbt(tv);
3237 			SOCK_LOCK(so);
3238 			valp = sopt->sopt_name == SO_SNDTIMEO ?
3239 			    (SOLISTENING(so) ? &so->sol_sbsnd_timeo :
3240 			    &so->so_snd.sb_timeo) :
3241 			    (SOLISTENING(so) ? &so->sol_sbrcv_timeo :
3242 			    &so->so_rcv.sb_timeo);
3243 			*valp = val;
3244 			SOCK_UNLOCK(so);
3245 			break;
3246 
3247 		case SO_LABEL:
3248 #ifdef MAC
3249 			error = sooptcopyin(sopt, &extmac, sizeof extmac,
3250 			    sizeof extmac);
3251 			if (error)
3252 				goto bad;
3253 			error = mac_setsockopt_label(sopt->sopt_td->td_ucred,
3254 			    so, &extmac);
3255 #else
3256 			error = EOPNOTSUPP;
3257 #endif
3258 			break;
3259 
3260 		case SO_TS_CLOCK:
3261 			error = sooptcopyin(sopt, &optval, sizeof optval,
3262 			    sizeof optval);
3263 			if (error)
3264 				goto bad;
3265 			if (optval < 0 || optval > SO_TS_CLOCK_MAX) {
3266 				error = EINVAL;
3267 				goto bad;
3268 			}
3269 			so->so_ts_clock = optval;
3270 			break;
3271 
3272 		case SO_MAX_PACING_RATE:
3273 			error = sooptcopyin(sopt, &val32, sizeof(val32),
3274 			    sizeof(val32));
3275 			if (error)
3276 				goto bad;
3277 			so->so_max_pacing_rate = val32;
3278 			break;
3279 
3280 		default:
3281 #ifdef SOCKET_HHOOK
3282 			if (V_socket_hhh[HHOOK_SOCKET_OPT]->hhh_nhooks > 0)
3283 				error = hhook_run_socket(so, sopt,
3284 				    HHOOK_SOCKET_OPT);
3285 			else
3286 #endif
3287 				error = ENOPROTOOPT;
3288 			break;
3289 		}
3290 		if (error == 0 && so->so_proto->pr_ctloutput != NULL)
3291 			(void)(*so->so_proto->pr_ctloutput)(so, sopt);
3292 	}
3293 bad:
3294 	CURVNET_RESTORE();
3295 	return (error);
3296 }
3297 
3298 /*
3299  * Helper routine for getsockopt.
3300  */
3301 int
3302 sooptcopyout(struct sockopt *sopt, const void *buf, size_t len)
3303 {
3304 	int	error;
3305 	size_t	valsize;
3306 
3307 	error = 0;
3308 
3309 	/*
3310 	 * Documented get behavior is that we always return a value, possibly
3311 	 * truncated to fit in the user's buffer.  Traditional behavior is
3312 	 * that we always tell the user precisely how much we copied, rather
3313 	 * than something useful like the total amount we had available for
3314 	 * her.  Note that this interface is not idempotent; the entire
3315 	 * answer must be generated ahead of time.
3316 	 */
3317 	valsize = min(len, sopt->sopt_valsize);
3318 	sopt->sopt_valsize = valsize;
3319 	if (sopt->sopt_val != NULL) {
3320 		if (sopt->sopt_td != NULL)
3321 			error = copyout(buf, sopt->sopt_val, valsize);
3322 		else
3323 			bcopy(buf, sopt->sopt_val, valsize);
3324 	}
3325 	return (error);
3326 }
3327 
3328 int
3329 sogetopt(struct socket *so, struct sockopt *sopt)
3330 {
3331 	int	error, optval;
3332 	struct	linger l;
3333 	struct	timeval tv;
3334 #ifdef MAC
3335 	struct mac extmac;
3336 #endif
3337 
3338 	CURVNET_SET(so->so_vnet);
3339 	error = 0;
3340 	if (sopt->sopt_level != SOL_SOCKET) {
3341 		if (so->so_proto->pr_ctloutput != NULL)
3342 			error = (*so->so_proto->pr_ctloutput)(so, sopt);
3343 		else
3344 			error = ENOPROTOOPT;
3345 		CURVNET_RESTORE();
3346 		return (error);
3347 	} else {
3348 		switch (sopt->sopt_name) {
3349 		case SO_ACCEPTFILTER:
3350 			error = accept_filt_getopt(so, sopt);
3351 			break;
3352 
3353 		case SO_LINGER:
3354 			SOCK_LOCK(so);
3355 			l.l_onoff = so->so_options & SO_LINGER;
3356 			l.l_linger = so->so_linger;
3357 			SOCK_UNLOCK(so);
3358 			error = sooptcopyout(sopt, &l, sizeof l);
3359 			break;
3360 
3361 		case SO_USELOOPBACK:
3362 		case SO_DONTROUTE:
3363 		case SO_DEBUG:
3364 		case SO_KEEPALIVE:
3365 		case SO_REUSEADDR:
3366 		case SO_REUSEPORT:
3367 		case SO_REUSEPORT_LB:
3368 		case SO_BROADCAST:
3369 		case SO_OOBINLINE:
3370 		case SO_ACCEPTCONN:
3371 		case SO_TIMESTAMP:
3372 		case SO_BINTIME:
3373 		case SO_NOSIGPIPE:
3374 		case SO_NO_DDP:
3375 		case SO_NO_OFFLOAD:
3376 		case SO_RERROR:
3377 			optval = so->so_options & sopt->sopt_name;
3378 integer:
3379 			error = sooptcopyout(sopt, &optval, sizeof optval);
3380 			break;
3381 
3382 		case SO_DOMAIN:
3383 			optval = so->so_proto->pr_domain->dom_family;
3384 			goto integer;
3385 
3386 		case SO_TYPE:
3387 			optval = so->so_type;
3388 			goto integer;
3389 
3390 		case SO_PROTOCOL:
3391 			optval = so->so_proto->pr_protocol;
3392 			goto integer;
3393 
3394 		case SO_ERROR:
3395 			SOCK_LOCK(so);
3396 			if (so->so_error) {
3397 				optval = so->so_error;
3398 				so->so_error = 0;
3399 			} else {
3400 				optval = so->so_rerror;
3401 				so->so_rerror = 0;
3402 			}
3403 			SOCK_UNLOCK(so);
3404 			goto integer;
3405 
3406 		case SO_SNDBUF:
3407 			optval = SOLISTENING(so) ? so->sol_sbsnd_hiwat :
3408 			    so->so_snd.sb_hiwat;
3409 			goto integer;
3410 
3411 		case SO_RCVBUF:
3412 			optval = SOLISTENING(so) ? so->sol_sbrcv_hiwat :
3413 			    so->so_rcv.sb_hiwat;
3414 			goto integer;
3415 
3416 		case SO_SNDLOWAT:
3417 			optval = SOLISTENING(so) ? so->sol_sbsnd_lowat :
3418 			    so->so_snd.sb_lowat;
3419 			goto integer;
3420 
3421 		case SO_RCVLOWAT:
3422 			optval = SOLISTENING(so) ? so->sol_sbrcv_lowat :
3423 			    so->so_rcv.sb_lowat;
3424 			goto integer;
3425 
3426 		case SO_SNDTIMEO:
3427 		case SO_RCVTIMEO:
3428 			SOCK_LOCK(so);
3429 			tv = sbttotv(sopt->sopt_name == SO_SNDTIMEO ?
3430 			    (SOLISTENING(so) ? so->sol_sbsnd_timeo :
3431 			    so->so_snd.sb_timeo) :
3432 			    (SOLISTENING(so) ? so->sol_sbrcv_timeo :
3433 			    so->so_rcv.sb_timeo));
3434 			SOCK_UNLOCK(so);
3435 #ifdef COMPAT_FREEBSD32
3436 			if (SV_CURPROC_FLAG(SV_ILP32)) {
3437 				struct timeval32 tv32;
3438 
3439 				CP(tv, tv32, tv_sec);
3440 				CP(tv, tv32, tv_usec);
3441 				error = sooptcopyout(sopt, &tv32, sizeof tv32);
3442 			} else
3443 #endif
3444 				error = sooptcopyout(sopt, &tv, sizeof tv);
3445 			break;
3446 
3447 		case SO_LABEL:
3448 #ifdef MAC
3449 			error = sooptcopyin(sopt, &extmac, sizeof(extmac),
3450 			    sizeof(extmac));
3451 			if (error)
3452 				goto bad;
3453 			error = mac_getsockopt_label(sopt->sopt_td->td_ucred,
3454 			    so, &extmac);
3455 			if (error)
3456 				goto bad;
3457 			/* Don't copy out extmac, it is unchanged. */
3458 #else
3459 			error = EOPNOTSUPP;
3460 #endif
3461 			break;
3462 
3463 		case SO_PEERLABEL:
3464 #ifdef MAC
3465 			error = sooptcopyin(sopt, &extmac, sizeof(extmac),
3466 			    sizeof(extmac));
3467 			if (error)
3468 				goto bad;
3469 			error = mac_getsockopt_peerlabel(
3470 			    sopt->sopt_td->td_ucred, so, &extmac);
3471 			if (error)
3472 				goto bad;
3473 			/* Don't copy out extmac, it is unchanged. */
3474 #else
3475 			error = EOPNOTSUPP;
3476 #endif
3477 			break;
3478 
3479 		case SO_LISTENQLIMIT:
3480 			optval = SOLISTENING(so) ? so->sol_qlimit : 0;
3481 			goto integer;
3482 
3483 		case SO_LISTENQLEN:
3484 			optval = SOLISTENING(so) ? so->sol_qlen : 0;
3485 			goto integer;
3486 
3487 		case SO_LISTENINCQLEN:
3488 			optval = SOLISTENING(so) ? so->sol_incqlen : 0;
3489 			goto integer;
3490 
3491 		case SO_TS_CLOCK:
3492 			optval = so->so_ts_clock;
3493 			goto integer;
3494 
3495 		case SO_MAX_PACING_RATE:
3496 			optval = so->so_max_pacing_rate;
3497 			goto integer;
3498 
3499 		default:
3500 #ifdef SOCKET_HHOOK
3501 			if (V_socket_hhh[HHOOK_SOCKET_OPT]->hhh_nhooks > 0)
3502 				error = hhook_run_socket(so, sopt,
3503 				    HHOOK_SOCKET_OPT);
3504 			else
3505 #endif
3506 				error = ENOPROTOOPT;
3507 			break;
3508 		}
3509 	}
3510 #ifdef MAC
3511 bad:
3512 #endif
3513 	CURVNET_RESTORE();
3514 	return (error);
3515 }
3516 
3517 int
3518 soopt_getm(struct sockopt *sopt, struct mbuf **mp)
3519 {
3520 	struct mbuf *m, *m_prev;
3521 	int sopt_size = sopt->sopt_valsize;
3522 
3523 	MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
3524 	if (m == NULL)
3525 		return ENOBUFS;
3526 	if (sopt_size > MLEN) {
3527 		MCLGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT);
3528 		if ((m->m_flags & M_EXT) == 0) {
3529 			m_free(m);
3530 			return ENOBUFS;
3531 		}
3532 		m->m_len = min(MCLBYTES, sopt_size);
3533 	} else {
3534 		m->m_len = min(MLEN, sopt_size);
3535 	}
3536 	sopt_size -= m->m_len;
3537 	*mp = m;
3538 	m_prev = m;
3539 
3540 	while (sopt_size) {
3541 		MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
3542 		if (m == NULL) {
3543 			m_freem(*mp);
3544 			return ENOBUFS;
3545 		}
3546 		if (sopt_size > MLEN) {
3547 			MCLGET(m, sopt->sopt_td != NULL ? M_WAITOK :
3548 			    M_NOWAIT);
3549 			if ((m->m_flags & M_EXT) == 0) {
3550 				m_freem(m);
3551 				m_freem(*mp);
3552 				return ENOBUFS;
3553 			}
3554 			m->m_len = min(MCLBYTES, sopt_size);
3555 		} else {
3556 			m->m_len = min(MLEN, sopt_size);
3557 		}
3558 		sopt_size -= m->m_len;
3559 		m_prev->m_next = m;
3560 		m_prev = m;
3561 	}
3562 	return (0);
3563 }
3564 
3565 int
3566 soopt_mcopyin(struct sockopt *sopt, struct mbuf *m)
3567 {
3568 	struct mbuf *m0 = m;
3569 
3570 	if (sopt->sopt_val == NULL)
3571 		return (0);
3572 	while (m != NULL && sopt->sopt_valsize >= m->m_len) {
3573 		if (sopt->sopt_td != NULL) {
3574 			int error;
3575 
3576 			error = copyin(sopt->sopt_val, mtod(m, char *),
3577 			    m->m_len);
3578 			if (error != 0) {
3579 				m_freem(m0);
3580 				return(error);
3581 			}
3582 		} else
3583 			bcopy(sopt->sopt_val, mtod(m, char *), m->m_len);
3584 		sopt->sopt_valsize -= m->m_len;
3585 		sopt->sopt_val = (char *)sopt->sopt_val + m->m_len;
3586 		m = m->m_next;
3587 	}
3588 	if (m != NULL) /* should be allocated enoughly at ip6_sooptmcopyin() */
3589 		panic("ip6_sooptmcopyin");
3590 	return (0);
3591 }
3592 
3593 int
3594 soopt_mcopyout(struct sockopt *sopt, struct mbuf *m)
3595 {
3596 	struct mbuf *m0 = m;
3597 	size_t valsize = 0;
3598 
3599 	if (sopt->sopt_val == NULL)
3600 		return (0);
3601 	while (m != NULL && sopt->sopt_valsize >= m->m_len) {
3602 		if (sopt->sopt_td != NULL) {
3603 			int error;
3604 
3605 			error = copyout(mtod(m, char *), sopt->sopt_val,
3606 			    m->m_len);
3607 			if (error != 0) {
3608 				m_freem(m0);
3609 				return(error);
3610 			}
3611 		} else
3612 			bcopy(mtod(m, char *), sopt->sopt_val, m->m_len);
3613 		sopt->sopt_valsize -= m->m_len;
3614 		sopt->sopt_val = (char *)sopt->sopt_val + m->m_len;
3615 		valsize += m->m_len;
3616 		m = m->m_next;
3617 	}
3618 	if (m != NULL) {
3619 		/* enough soopt buffer should be given from user-land */
3620 		m_freem(m0);
3621 		return(EINVAL);
3622 	}
3623 	sopt->sopt_valsize = valsize;
3624 	return (0);
3625 }
3626 
3627 /*
3628  * sohasoutofband(): protocol notifies socket layer of the arrival of new
3629  * out-of-band data, which will then notify socket consumers.
3630  */
3631 void
3632 sohasoutofband(struct socket *so)
3633 {
3634 
3635 	if (so->so_sigio != NULL)
3636 		pgsigio(&so->so_sigio, SIGURG, 0);
3637 	selwakeuppri(&so->so_rdsel, PSOCK);
3638 }
3639 
3640 int
3641 sopoll(struct socket *so, int events, struct ucred *active_cred,
3642     struct thread *td)
3643 {
3644 
3645 	/*
3646 	 * We do not need to set or assert curvnet as long as everyone uses
3647 	 * sopoll_generic().
3648 	 */
3649 	return (so->so_proto->pr_sopoll(so, events, active_cred, td));
3650 }
3651 
3652 int
3653 sopoll_generic(struct socket *so, int events, struct ucred *active_cred,
3654     struct thread *td)
3655 {
3656 	int revents;
3657 
3658 	SOCK_LOCK(so);
3659 	if (SOLISTENING(so)) {
3660 		if (!(events & (POLLIN | POLLRDNORM)))
3661 			revents = 0;
3662 		else if (!TAILQ_EMPTY(&so->sol_comp))
3663 			revents = events & (POLLIN | POLLRDNORM);
3664 		else if ((events & POLLINIGNEOF) == 0 && so->so_error)
3665 			revents = (events & (POLLIN | POLLRDNORM)) | POLLHUP;
3666 		else {
3667 			selrecord(td, &so->so_rdsel);
3668 			revents = 0;
3669 		}
3670 	} else {
3671 		revents = 0;
3672 		SOCK_SENDBUF_LOCK(so);
3673 		SOCK_RECVBUF_LOCK(so);
3674 		if (events & (POLLIN | POLLRDNORM))
3675 			if (soreadabledata(so))
3676 				revents |= events & (POLLIN | POLLRDNORM);
3677 		if (events & (POLLOUT | POLLWRNORM))
3678 			if (sowriteable(so))
3679 				revents |= events & (POLLOUT | POLLWRNORM);
3680 		if (events & (POLLPRI | POLLRDBAND))
3681 			if (so->so_oobmark ||
3682 			    (so->so_rcv.sb_state & SBS_RCVATMARK))
3683 				revents |= events & (POLLPRI | POLLRDBAND);
3684 		if ((events & POLLINIGNEOF) == 0) {
3685 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
3686 				revents |= events & (POLLIN | POLLRDNORM);
3687 				if (so->so_snd.sb_state & SBS_CANTSENDMORE)
3688 					revents |= POLLHUP;
3689 			}
3690 		}
3691 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE)
3692 			revents |= events & POLLRDHUP;
3693 		if (revents == 0) {
3694 			if (events &
3695 			    (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND | POLLRDHUP)) {
3696 				selrecord(td, &so->so_rdsel);
3697 				so->so_rcv.sb_flags |= SB_SEL;
3698 			}
3699 			if (events & (POLLOUT | POLLWRNORM)) {
3700 				selrecord(td, &so->so_wrsel);
3701 				so->so_snd.sb_flags |= SB_SEL;
3702 			}
3703 		}
3704 		SOCK_RECVBUF_UNLOCK(so);
3705 		SOCK_SENDBUF_UNLOCK(so);
3706 	}
3707 	SOCK_UNLOCK(so);
3708 	return (revents);
3709 }
3710 
3711 int
3712 soo_kqfilter(struct file *fp, struct knote *kn)
3713 {
3714 	struct socket *so = kn->kn_fp->f_data;
3715 	struct sockbuf *sb;
3716 	sb_which which;
3717 	struct knlist *knl;
3718 
3719 	switch (kn->kn_filter) {
3720 	case EVFILT_READ:
3721 		kn->kn_fop = &soread_filtops;
3722 		knl = &so->so_rdsel.si_note;
3723 		sb = &so->so_rcv;
3724 		which = SO_RCV;
3725 		break;
3726 	case EVFILT_WRITE:
3727 		kn->kn_fop = &sowrite_filtops;
3728 		knl = &so->so_wrsel.si_note;
3729 		sb = &so->so_snd;
3730 		which = SO_SND;
3731 		break;
3732 	case EVFILT_EMPTY:
3733 		kn->kn_fop = &soempty_filtops;
3734 		knl = &so->so_wrsel.si_note;
3735 		sb = &so->so_snd;
3736 		which = SO_SND;
3737 		break;
3738 	default:
3739 		return (EINVAL);
3740 	}
3741 
3742 	SOCK_LOCK(so);
3743 	if (SOLISTENING(so)) {
3744 		knlist_add(knl, kn, 1);
3745 	} else {
3746 		SOCK_BUF_LOCK(so, which);
3747 		knlist_add(knl, kn, 1);
3748 		sb->sb_flags |= SB_KNOTE;
3749 		SOCK_BUF_UNLOCK(so, which);
3750 	}
3751 	SOCK_UNLOCK(so);
3752 	return (0);
3753 }
3754 
3755 static void
3756 filt_sordetach(struct knote *kn)
3757 {
3758 	struct socket *so = kn->kn_fp->f_data;
3759 
3760 	so_rdknl_lock(so);
3761 	knlist_remove(&so->so_rdsel.si_note, kn, 1);
3762 	if (!SOLISTENING(so) && knlist_empty(&so->so_rdsel.si_note))
3763 		so->so_rcv.sb_flags &= ~SB_KNOTE;
3764 	so_rdknl_unlock(so);
3765 }
3766 
3767 /*ARGSUSED*/
3768 static int
3769 filt_soread(struct knote *kn, long hint)
3770 {
3771 	struct socket *so;
3772 
3773 	so = kn->kn_fp->f_data;
3774 
3775 	if (SOLISTENING(so)) {
3776 		SOCK_LOCK_ASSERT(so);
3777 		kn->kn_data = so->sol_qlen;
3778 		if (so->so_error) {
3779 			kn->kn_flags |= EV_EOF;
3780 			kn->kn_fflags = so->so_error;
3781 			return (1);
3782 		}
3783 		return (!TAILQ_EMPTY(&so->sol_comp));
3784 	}
3785 
3786 	SOCK_RECVBUF_LOCK_ASSERT(so);
3787 
3788 	kn->kn_data = sbavail(&so->so_rcv) - so->so_rcv.sb_ctl;
3789 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
3790 		kn->kn_flags |= EV_EOF;
3791 		kn->kn_fflags = so->so_error;
3792 		return (1);
3793 	} else if (so->so_error || so->so_rerror)
3794 		return (1);
3795 
3796 	if (kn->kn_sfflags & NOTE_LOWAT) {
3797 		if (kn->kn_data >= kn->kn_sdata)
3798 			return (1);
3799 	} else if (sbavail(&so->so_rcv) >= so->so_rcv.sb_lowat)
3800 		return (1);
3801 
3802 #ifdef SOCKET_HHOOK
3803 	/* This hook returning non-zero indicates an event, not error */
3804 	return (hhook_run_socket(so, NULL, HHOOK_FILT_SOREAD));
3805 #else
3806 	return (0);
3807 #endif
3808 }
3809 
3810 static void
3811 filt_sowdetach(struct knote *kn)
3812 {
3813 	struct socket *so = kn->kn_fp->f_data;
3814 
3815 	so_wrknl_lock(so);
3816 	knlist_remove(&so->so_wrsel.si_note, kn, 1);
3817 	if (!SOLISTENING(so) && knlist_empty(&so->so_wrsel.si_note))
3818 		so->so_snd.sb_flags &= ~SB_KNOTE;
3819 	so_wrknl_unlock(so);
3820 }
3821 
3822 /*ARGSUSED*/
3823 static int
3824 filt_sowrite(struct knote *kn, long hint)
3825 {
3826 	struct socket *so;
3827 
3828 	so = kn->kn_fp->f_data;
3829 
3830 	if (SOLISTENING(so))
3831 		return (0);
3832 
3833 	SOCK_SENDBUF_LOCK_ASSERT(so);
3834 	kn->kn_data = sbspace(&so->so_snd);
3835 
3836 #ifdef SOCKET_HHOOK
3837 	hhook_run_socket(so, kn, HHOOK_FILT_SOWRITE);
3838 #endif
3839 
3840 	if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
3841 		kn->kn_flags |= EV_EOF;
3842 		kn->kn_fflags = so->so_error;
3843 		return (1);
3844 	} else if (so->so_error)	/* temporary udp error */
3845 		return (1);
3846 	else if (((so->so_state & SS_ISCONNECTED) == 0) &&
3847 	    (so->so_proto->pr_flags & PR_CONNREQUIRED))
3848 		return (0);
3849 	else if (kn->kn_sfflags & NOTE_LOWAT)
3850 		return (kn->kn_data >= kn->kn_sdata);
3851 	else
3852 		return (kn->kn_data >= so->so_snd.sb_lowat);
3853 }
3854 
3855 static int
3856 filt_soempty(struct knote *kn, long hint)
3857 {
3858 	struct socket *so;
3859 
3860 	so = kn->kn_fp->f_data;
3861 
3862 	if (SOLISTENING(so))
3863 		return (1);
3864 
3865 	SOCK_SENDBUF_LOCK_ASSERT(so);
3866 	kn->kn_data = sbused(&so->so_snd);
3867 
3868 	if (kn->kn_data == 0)
3869 		return (1);
3870 	else
3871 		return (0);
3872 }
3873 
3874 int
3875 socheckuid(struct socket *so, uid_t uid)
3876 {
3877 
3878 	if (so == NULL)
3879 		return (EPERM);
3880 	if (so->so_cred->cr_uid != uid)
3881 		return (EPERM);
3882 	return (0);
3883 }
3884 
3885 /*
3886  * These functions are used by protocols to notify the socket layer (and its
3887  * consumers) of state changes in the sockets driven by protocol-side events.
3888  */
3889 
3890 /*
3891  * Procedures to manipulate state flags of socket and do appropriate wakeups.
3892  *
3893  * Normal sequence from the active (originating) side is that
3894  * soisconnecting() is called during processing of connect() call, resulting
3895  * in an eventual call to soisconnected() if/when the connection is
3896  * established.  When the connection is torn down soisdisconnecting() is
3897  * called during processing of disconnect() call, and soisdisconnected() is
3898  * called when the connection to the peer is totally severed.  The semantics
3899  * of these routines are such that connectionless protocols can call
3900  * soisconnected() and soisdisconnected() only, bypassing the in-progress
3901  * calls when setting up a ``connection'' takes no time.
3902  *
3903  * From the passive side, a socket is created with two queues of sockets:
3904  * so_incomp for connections in progress and so_comp for connections already
3905  * made and awaiting user acceptance.  As a protocol is preparing incoming
3906  * connections, it creates a socket structure queued on so_incomp by calling
3907  * sonewconn().  When the connection is established, soisconnected() is
3908  * called, and transfers the socket structure to so_comp, making it available
3909  * to accept().
3910  *
3911  * If a socket is closed with sockets on either so_incomp or so_comp, these
3912  * sockets are dropped.
3913  *
3914  * If higher-level protocols are implemented in the kernel, the wakeups done
3915  * here will sometimes cause software-interrupt process scheduling.
3916  */
3917 void
3918 soisconnecting(struct socket *so)
3919 {
3920 
3921 	SOCK_LOCK(so);
3922 	so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
3923 	so->so_state |= SS_ISCONNECTING;
3924 	SOCK_UNLOCK(so);
3925 }
3926 
3927 void
3928 soisconnected(struct socket *so)
3929 {
3930 	bool last __diagused;
3931 
3932 	SOCK_LOCK(so);
3933 	so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING);
3934 	so->so_state |= SS_ISCONNECTED;
3935 
3936 	if (so->so_qstate == SQ_INCOMP) {
3937 		struct socket *head = so->so_listen;
3938 		int ret;
3939 
3940 		KASSERT(head, ("%s: so %p on incomp of NULL", __func__, so));
3941 		/*
3942 		 * Promoting a socket from incomplete queue to complete, we
3943 		 * need to go through reverse order of locking.  We first do
3944 		 * trylock, and if that doesn't succeed, we go the hard way
3945 		 * leaving a reference and rechecking consistency after proper
3946 		 * locking.
3947 		 */
3948 		if (__predict_false(SOLISTEN_TRYLOCK(head) == 0)) {
3949 			soref(head);
3950 			SOCK_UNLOCK(so);
3951 			SOLISTEN_LOCK(head);
3952 			SOCK_LOCK(so);
3953 			if (__predict_false(head != so->so_listen)) {
3954 				/*
3955 				 * The socket went off the listen queue,
3956 				 * should be lost race to close(2) of sol.
3957 				 * The socket is about to soabort().
3958 				 */
3959 				SOCK_UNLOCK(so);
3960 				sorele_locked(head);
3961 				return;
3962 			}
3963 			last = refcount_release(&head->so_count);
3964 			KASSERT(!last, ("%s: released last reference for %p",
3965 			    __func__, head));
3966 		}
3967 again:
3968 		if ((so->so_options & SO_ACCEPTFILTER) == 0) {
3969 			TAILQ_REMOVE(&head->sol_incomp, so, so_list);
3970 			head->sol_incqlen--;
3971 			TAILQ_INSERT_TAIL(&head->sol_comp, so, so_list);
3972 			head->sol_qlen++;
3973 			so->so_qstate = SQ_COMP;
3974 			SOCK_UNLOCK(so);
3975 			solisten_wakeup(head);	/* unlocks */
3976 		} else {
3977 			SOCK_RECVBUF_LOCK(so);
3978 			soupcall_set(so, SO_RCV,
3979 			    head->sol_accept_filter->accf_callback,
3980 			    head->sol_accept_filter_arg);
3981 			so->so_options &= ~SO_ACCEPTFILTER;
3982 			ret = head->sol_accept_filter->accf_callback(so,
3983 			    head->sol_accept_filter_arg, M_NOWAIT);
3984 			if (ret == SU_ISCONNECTED) {
3985 				soupcall_clear(so, SO_RCV);
3986 				SOCK_RECVBUF_UNLOCK(so);
3987 				goto again;
3988 			}
3989 			SOCK_RECVBUF_UNLOCK(so);
3990 			SOCK_UNLOCK(so);
3991 			SOLISTEN_UNLOCK(head);
3992 		}
3993 		return;
3994 	}
3995 	SOCK_UNLOCK(so);
3996 	wakeup(&so->so_timeo);
3997 	sorwakeup(so);
3998 	sowwakeup(so);
3999 }
4000 
4001 void
4002 soisdisconnecting(struct socket *so)
4003 {
4004 
4005 	SOCK_LOCK(so);
4006 	so->so_state &= ~SS_ISCONNECTING;
4007 	so->so_state |= SS_ISDISCONNECTING;
4008 
4009 	if (!SOLISTENING(so)) {
4010 		SOCK_RECVBUF_LOCK(so);
4011 		socantrcvmore_locked(so);
4012 		SOCK_SENDBUF_LOCK(so);
4013 		socantsendmore_locked(so);
4014 	}
4015 	SOCK_UNLOCK(so);
4016 	wakeup(&so->so_timeo);
4017 }
4018 
4019 void
4020 soisdisconnected(struct socket *so)
4021 {
4022 
4023 	SOCK_LOCK(so);
4024 
4025 	/*
4026 	 * There is at least one reader of so_state that does not
4027 	 * acquire socket lock, namely soreceive_generic().  Ensure
4028 	 * that it never sees all flags that track connection status
4029 	 * cleared, by ordering the update with a barrier semantic of
4030 	 * our release thread fence.
4031 	 */
4032 	so->so_state |= SS_ISDISCONNECTED;
4033 	atomic_thread_fence_rel();
4034 	so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
4035 
4036 	if (!SOLISTENING(so)) {
4037 		SOCK_UNLOCK(so);
4038 		SOCK_RECVBUF_LOCK(so);
4039 		socantrcvmore_locked(so);
4040 		SOCK_SENDBUF_LOCK(so);
4041 		sbdrop_locked(&so->so_snd, sbused(&so->so_snd));
4042 		socantsendmore_locked(so);
4043 	} else
4044 		SOCK_UNLOCK(so);
4045 	wakeup(&so->so_timeo);
4046 }
4047 
4048 int
4049 soiolock(struct socket *so, struct sx *sx, int flags)
4050 {
4051 	int error;
4052 
4053 	KASSERT((flags & SBL_VALID) == flags,
4054 	    ("soiolock: invalid flags %#x", flags));
4055 
4056 	if ((flags & SBL_WAIT) != 0) {
4057 		if ((flags & SBL_NOINTR) != 0) {
4058 			sx_xlock(sx);
4059 		} else {
4060 			error = sx_xlock_sig(sx);
4061 			if (error != 0)
4062 				return (error);
4063 		}
4064 	} else if (!sx_try_xlock(sx)) {
4065 		return (EWOULDBLOCK);
4066 	}
4067 
4068 	if (__predict_false(SOLISTENING(so))) {
4069 		sx_xunlock(sx);
4070 		return (ENOTCONN);
4071 	}
4072 	return (0);
4073 }
4074 
4075 void
4076 soiounlock(struct sx *sx)
4077 {
4078 	sx_xunlock(sx);
4079 }
4080 
4081 /*
4082  * Make a copy of a sockaddr in a malloced buffer of type M_SONAME.
4083  */
4084 struct sockaddr *
4085 sodupsockaddr(const struct sockaddr *sa, int mflags)
4086 {
4087 	struct sockaddr *sa2;
4088 
4089 	sa2 = malloc(sa->sa_len, M_SONAME, mflags);
4090 	if (sa2)
4091 		bcopy(sa, sa2, sa->sa_len);
4092 	return sa2;
4093 }
4094 
4095 /*
4096  * Register per-socket destructor.
4097  */
4098 void
4099 sodtor_set(struct socket *so, so_dtor_t *func)
4100 {
4101 
4102 	SOCK_LOCK_ASSERT(so);
4103 	so->so_dtor = func;
4104 }
4105 
4106 /*
4107  * Register per-socket buffer upcalls.
4108  */
4109 void
4110 soupcall_set(struct socket *so, sb_which which, so_upcall_t func, void *arg)
4111 {
4112 	struct sockbuf *sb;
4113 
4114 	KASSERT(!SOLISTENING(so), ("%s: so %p listening", __func__, so));
4115 
4116 	switch (which) {
4117 	case SO_RCV:
4118 		sb = &so->so_rcv;
4119 		break;
4120 	case SO_SND:
4121 		sb = &so->so_snd;
4122 		break;
4123 	}
4124 	SOCK_BUF_LOCK_ASSERT(so, which);
4125 	sb->sb_upcall = func;
4126 	sb->sb_upcallarg = arg;
4127 	sb->sb_flags |= SB_UPCALL;
4128 }
4129 
4130 void
4131 soupcall_clear(struct socket *so, sb_which which)
4132 {
4133 	struct sockbuf *sb;
4134 
4135 	KASSERT(!SOLISTENING(so), ("%s: so %p listening", __func__, so));
4136 
4137 	switch (which) {
4138 	case SO_RCV:
4139 		sb = &so->so_rcv;
4140 		break;
4141 	case SO_SND:
4142 		sb = &so->so_snd;
4143 		break;
4144 	}
4145 	SOCK_BUF_LOCK_ASSERT(so, which);
4146 	KASSERT(sb->sb_upcall != NULL,
4147 	    ("%s: so %p no upcall to clear", __func__, so));
4148 	sb->sb_upcall = NULL;
4149 	sb->sb_upcallarg = NULL;
4150 	sb->sb_flags &= ~SB_UPCALL;
4151 }
4152 
4153 void
4154 solisten_upcall_set(struct socket *so, so_upcall_t func, void *arg)
4155 {
4156 
4157 	SOLISTEN_LOCK_ASSERT(so);
4158 	so->sol_upcall = func;
4159 	so->sol_upcallarg = arg;
4160 }
4161 
4162 static void
4163 so_rdknl_lock(void *arg)
4164 {
4165 	struct socket *so = arg;
4166 
4167 retry:
4168 	if (SOLISTENING(so)) {
4169 		SOLISTEN_LOCK(so);
4170 	} else {
4171 		SOCK_RECVBUF_LOCK(so);
4172 		if (__predict_false(SOLISTENING(so))) {
4173 			SOCK_RECVBUF_UNLOCK(so);
4174 			goto retry;
4175 		}
4176 	}
4177 }
4178 
4179 static void
4180 so_rdknl_unlock(void *arg)
4181 {
4182 	struct socket *so = arg;
4183 
4184 	if (SOLISTENING(so))
4185 		SOLISTEN_UNLOCK(so);
4186 	else
4187 		SOCK_RECVBUF_UNLOCK(so);
4188 }
4189 
4190 static void
4191 so_rdknl_assert_lock(void *arg, int what)
4192 {
4193 	struct socket *so = arg;
4194 
4195 	if (what == LA_LOCKED) {
4196 		if (SOLISTENING(so))
4197 			SOLISTEN_LOCK_ASSERT(so);
4198 		else
4199 			SOCK_RECVBUF_LOCK_ASSERT(so);
4200 	} else {
4201 		if (SOLISTENING(so))
4202 			SOLISTEN_UNLOCK_ASSERT(so);
4203 		else
4204 			SOCK_RECVBUF_UNLOCK_ASSERT(so);
4205 	}
4206 }
4207 
4208 static void
4209 so_wrknl_lock(void *arg)
4210 {
4211 	struct socket *so = arg;
4212 
4213 retry:
4214 	if (SOLISTENING(so)) {
4215 		SOLISTEN_LOCK(so);
4216 	} else {
4217 		SOCK_SENDBUF_LOCK(so);
4218 		if (__predict_false(SOLISTENING(so))) {
4219 			SOCK_SENDBUF_UNLOCK(so);
4220 			goto retry;
4221 		}
4222 	}
4223 }
4224 
4225 static void
4226 so_wrknl_unlock(void *arg)
4227 {
4228 	struct socket *so = arg;
4229 
4230 	if (SOLISTENING(so))
4231 		SOLISTEN_UNLOCK(so);
4232 	else
4233 		SOCK_SENDBUF_UNLOCK(so);
4234 }
4235 
4236 static void
4237 so_wrknl_assert_lock(void *arg, int what)
4238 {
4239 	struct socket *so = arg;
4240 
4241 	if (what == LA_LOCKED) {
4242 		if (SOLISTENING(so))
4243 			SOLISTEN_LOCK_ASSERT(so);
4244 		else
4245 			SOCK_SENDBUF_LOCK_ASSERT(so);
4246 	} else {
4247 		if (SOLISTENING(so))
4248 			SOLISTEN_UNLOCK_ASSERT(so);
4249 		else
4250 			SOCK_SENDBUF_UNLOCK_ASSERT(so);
4251 	}
4252 }
4253 
4254 /*
4255  * Create an external-format (``xsocket'') structure using the information in
4256  * the kernel-format socket structure pointed to by so.  This is done to
4257  * reduce the spew of irrelevant information over this interface, to isolate
4258  * user code from changes in the kernel structure, and potentially to provide
4259  * information-hiding if we decide that some of this information should be
4260  * hidden from users.
4261  */
4262 void
4263 sotoxsocket(struct socket *so, struct xsocket *xso)
4264 {
4265 
4266 	bzero(xso, sizeof(*xso));
4267 	xso->xso_len = sizeof *xso;
4268 	xso->xso_so = (uintptr_t)so;
4269 	xso->so_type = so->so_type;
4270 	xso->so_options = so->so_options;
4271 	xso->so_linger = so->so_linger;
4272 	xso->so_state = so->so_state;
4273 	xso->so_pcb = (uintptr_t)so->so_pcb;
4274 	xso->xso_protocol = so->so_proto->pr_protocol;
4275 	xso->xso_family = so->so_proto->pr_domain->dom_family;
4276 	xso->so_timeo = so->so_timeo;
4277 	xso->so_error = so->so_error;
4278 	xso->so_uid = so->so_cred->cr_uid;
4279 	xso->so_pgid = so->so_sigio ? so->so_sigio->sio_pgid : 0;
4280 	if (SOLISTENING(so)) {
4281 		xso->so_qlen = so->sol_qlen;
4282 		xso->so_incqlen = so->sol_incqlen;
4283 		xso->so_qlimit = so->sol_qlimit;
4284 		xso->so_oobmark = 0;
4285 	} else {
4286 		xso->so_state |= so->so_qstate;
4287 		xso->so_qlen = xso->so_incqlen = xso->so_qlimit = 0;
4288 		xso->so_oobmark = so->so_oobmark;
4289 		sbtoxsockbuf(&so->so_snd, &xso->so_snd);
4290 		sbtoxsockbuf(&so->so_rcv, &xso->so_rcv);
4291 	}
4292 }
4293 
4294 int
4295 so_options_get(const struct socket *so)
4296 {
4297 
4298 	return (so->so_options);
4299 }
4300 
4301 void
4302 so_options_set(struct socket *so, int val)
4303 {
4304 
4305 	so->so_options = val;
4306 }
4307 
4308 int
4309 so_error_get(const struct socket *so)
4310 {
4311 
4312 	return (so->so_error);
4313 }
4314 
4315 void
4316 so_error_set(struct socket *so, int val)
4317 {
4318 
4319 	so->so_error = val;
4320 }
4321