xref: /freebsd/sys/kern/uipc_socket.c (revision e63d20b70ee1dbee9b075f29de6f30cdcfe1abe1)
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 	SOCKBUF_LOCK(sb);
2613 
2614 #ifdef KERN_TLS
2615 	if (sb->sb_tls_info != NULL) {
2616 		SOCKBUF_UNLOCK(sb);
2617 		SOCK_IO_RECV_UNLOCK(so);
2618 		return (soreceive_generic(so, psa, uio, mp0, controlp,
2619 		    flagsp));
2620 	}
2621 #endif
2622 
2623 	/* Easy one, no space to copyout anything. */
2624 	if (uio->uio_resid == 0) {
2625 		error = EINVAL;
2626 		goto out;
2627 	}
2628 	oresid = uio->uio_resid;
2629 
2630 	/* We will never ever get anything unless we are or were connected. */
2631 	if (!(so->so_state & (SS_ISCONNECTED|SS_ISDISCONNECTED))) {
2632 		error = ENOTCONN;
2633 		goto out;
2634 	}
2635 
2636 restart:
2637 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2638 
2639 	/* Abort if socket has reported problems. */
2640 	if (so->so_error) {
2641 		if (sbavail(sb) > 0)
2642 			goto deliver;
2643 		if (oresid > uio->uio_resid)
2644 			goto out;
2645 		error = so->so_error;
2646 		if (!(flags & MSG_PEEK))
2647 			so->so_error = 0;
2648 		goto out;
2649 	}
2650 
2651 	/* Door is closed.  Deliver what is left, if any. */
2652 	if (sb->sb_state & SBS_CANTRCVMORE) {
2653 		if (sbavail(sb) > 0)
2654 			goto deliver;
2655 		else
2656 			goto out;
2657 	}
2658 
2659 	/* Socket buffer is empty and we shall not block. */
2660 	if (sbavail(sb) == 0 &&
2661 	    ((so->so_state & SS_NBIO) || (flags & (MSG_DONTWAIT|MSG_NBIO)))) {
2662 		error = EAGAIN;
2663 		goto out;
2664 	}
2665 
2666 	/* Socket buffer got some data that we shall deliver now. */
2667 	if (sbavail(sb) > 0 && !(flags & MSG_WAITALL) &&
2668 	    ((so->so_state & SS_NBIO) ||
2669 	     (flags & (MSG_DONTWAIT|MSG_NBIO)) ||
2670 	     sbavail(sb) >= sb->sb_lowat ||
2671 	     sbavail(sb) >= uio->uio_resid ||
2672 	     sbavail(sb) >= sb->sb_hiwat) ) {
2673 		goto deliver;
2674 	}
2675 
2676 	/* On MSG_WAITALL we must wait until all data or error arrives. */
2677 	if ((flags & MSG_WAITALL) &&
2678 	    (sbavail(sb) >= uio->uio_resid || sbavail(sb) >= sb->sb_hiwat))
2679 		goto deliver;
2680 
2681 	/*
2682 	 * Wait and block until (more) data comes in.
2683 	 * NB: Drops the sockbuf lock during wait.
2684 	 */
2685 	error = sbwait(so, SO_RCV);
2686 	if (error)
2687 		goto out;
2688 	goto restart;
2689 
2690 deliver:
2691 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2692 	KASSERT(sbavail(sb) > 0, ("%s: sockbuf empty", __func__));
2693 	KASSERT(sb->sb_mb != NULL, ("%s: sb_mb == NULL", __func__));
2694 
2695 	/* Statistics. */
2696 	if (uio->uio_td)
2697 		uio->uio_td->td_ru.ru_msgrcv++;
2698 
2699 	/* Fill uio until full or current end of socket buffer is reached. */
2700 	len = min(uio->uio_resid, sbavail(sb));
2701 	if (mp0 != NULL) {
2702 		/* Dequeue as many mbufs as possible. */
2703 		if (!(flags & MSG_PEEK) && len >= sb->sb_mb->m_len) {
2704 			if (*mp0 == NULL)
2705 				*mp0 = sb->sb_mb;
2706 			else
2707 				m_cat(*mp0, sb->sb_mb);
2708 			for (m = sb->sb_mb;
2709 			     m != NULL && m->m_len <= len;
2710 			     m = m->m_next) {
2711 				KASSERT(!(m->m_flags & M_NOTAVAIL),
2712 				    ("%s: m %p not available", __func__, m));
2713 				len -= m->m_len;
2714 				uio->uio_resid -= m->m_len;
2715 				sbfree(sb, m);
2716 				n = m;
2717 			}
2718 			n->m_next = NULL;
2719 			sb->sb_mb = m;
2720 			sb->sb_lastrecord = sb->sb_mb;
2721 			if (sb->sb_mb == NULL)
2722 				SB_EMPTY_FIXUP(sb);
2723 		}
2724 		/* Copy the remainder. */
2725 		if (len > 0) {
2726 			KASSERT(sb->sb_mb != NULL,
2727 			    ("%s: len > 0 && sb->sb_mb empty", __func__));
2728 
2729 			m = m_copym(sb->sb_mb, 0, len, M_NOWAIT);
2730 			if (m == NULL)
2731 				len = 0;	/* Don't flush data from sockbuf. */
2732 			else
2733 				uio->uio_resid -= len;
2734 			if (*mp0 != NULL)
2735 				m_cat(*mp0, m);
2736 			else
2737 				*mp0 = m;
2738 			if (*mp0 == NULL) {
2739 				error = ENOBUFS;
2740 				goto out;
2741 			}
2742 		}
2743 	} else {
2744 		/* NB: Must unlock socket buffer as uiomove may sleep. */
2745 		SOCKBUF_UNLOCK(sb);
2746 		error = m_mbuftouio(uio, sb->sb_mb, len);
2747 		SOCKBUF_LOCK(sb);
2748 		if (error)
2749 			goto out;
2750 	}
2751 	SBLASTRECORDCHK(sb);
2752 	SBLASTMBUFCHK(sb);
2753 
2754 	/*
2755 	 * Remove the delivered data from the socket buffer unless we
2756 	 * were only peeking.
2757 	 */
2758 	if (!(flags & MSG_PEEK)) {
2759 		if (len > 0)
2760 			sbdrop_locked(sb, len);
2761 
2762 		/* Notify protocol that we drained some data. */
2763 		if ((so->so_proto->pr_flags & PR_WANTRCVD) &&
2764 		    (((flags & MSG_WAITALL) && uio->uio_resid > 0) ||
2765 		     !(flags & MSG_SOCALLBCK))) {
2766 			SOCKBUF_UNLOCK(sb);
2767 			VNET_SO_ASSERT(so);
2768 			so->so_proto->pr_rcvd(so, flags);
2769 			SOCKBUF_LOCK(sb);
2770 		}
2771 	}
2772 
2773 	/*
2774 	 * For MSG_WAITALL we may have to loop again and wait for
2775 	 * more data to come in.
2776 	 */
2777 	if ((flags & MSG_WAITALL) && uio->uio_resid > 0)
2778 		goto restart;
2779 out:
2780 	SBLASTRECORDCHK(sb);
2781 	SBLASTMBUFCHK(sb);
2782 	SOCKBUF_UNLOCK(sb);
2783 	SOCK_IO_RECV_UNLOCK(so);
2784 	return (error);
2785 }
2786 
2787 /*
2788  * Optimized version of soreceive() for simple datagram cases from userspace.
2789  * Unlike in the stream case, we're able to drop a datagram if copyout()
2790  * fails, and because we handle datagrams atomically, we don't need to use a
2791  * sleep lock to prevent I/O interlacing.
2792  */
2793 int
2794 soreceive_dgram(struct socket *so, struct sockaddr **psa, struct uio *uio,
2795     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2796 {
2797 	struct mbuf *m, *m2;
2798 	int flags, error;
2799 	ssize_t len;
2800 	struct protosw *pr = so->so_proto;
2801 	struct mbuf *nextrecord;
2802 
2803 	if (psa != NULL)
2804 		*psa = NULL;
2805 	if (controlp != NULL)
2806 		*controlp = NULL;
2807 	if (flagsp != NULL)
2808 		flags = *flagsp &~ MSG_EOR;
2809 	else
2810 		flags = 0;
2811 
2812 	/*
2813 	 * For any complicated cases, fall back to the full
2814 	 * soreceive_generic().
2815 	 */
2816 	if (mp0 != NULL || (flags & (MSG_PEEK | MSG_OOB | MSG_TRUNC)))
2817 		return (soreceive_generic(so, psa, uio, mp0, controlp,
2818 		    flagsp));
2819 
2820 	/*
2821 	 * Enforce restrictions on use.
2822 	 */
2823 	KASSERT((pr->pr_flags & PR_WANTRCVD) == 0,
2824 	    ("soreceive_dgram: wantrcvd"));
2825 	KASSERT(pr->pr_flags & PR_ATOMIC, ("soreceive_dgram: !atomic"));
2826 	KASSERT((so->so_rcv.sb_state & SBS_RCVATMARK) == 0,
2827 	    ("soreceive_dgram: SBS_RCVATMARK"));
2828 	KASSERT((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0,
2829 	    ("soreceive_dgram: P_CONNREQUIRED"));
2830 
2831 	/*
2832 	 * Loop blocking while waiting for a datagram.
2833 	 */
2834 	SOCKBUF_LOCK(&so->so_rcv);
2835 	while ((m = so->so_rcv.sb_mb) == NULL) {
2836 		KASSERT(sbavail(&so->so_rcv) == 0,
2837 		    ("soreceive_dgram: sb_mb NULL but sbavail %u",
2838 		    sbavail(&so->so_rcv)));
2839 		if (so->so_error) {
2840 			error = so->so_error;
2841 			so->so_error = 0;
2842 			SOCKBUF_UNLOCK(&so->so_rcv);
2843 			return (error);
2844 		}
2845 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE ||
2846 		    uio->uio_resid == 0) {
2847 			SOCKBUF_UNLOCK(&so->so_rcv);
2848 			return (0);
2849 		}
2850 		if ((so->so_state & SS_NBIO) ||
2851 		    (flags & (MSG_DONTWAIT|MSG_NBIO))) {
2852 			SOCKBUF_UNLOCK(&so->so_rcv);
2853 			return (EWOULDBLOCK);
2854 		}
2855 		SBLASTRECORDCHK(&so->so_rcv);
2856 		SBLASTMBUFCHK(&so->so_rcv);
2857 		error = sbwait(so, SO_RCV);
2858 		if (error) {
2859 			SOCKBUF_UNLOCK(&so->so_rcv);
2860 			return (error);
2861 		}
2862 	}
2863 	SOCKBUF_LOCK_ASSERT(&so->so_rcv);
2864 
2865 	if (uio->uio_td)
2866 		uio->uio_td->td_ru.ru_msgrcv++;
2867 	SBLASTRECORDCHK(&so->so_rcv);
2868 	SBLASTMBUFCHK(&so->so_rcv);
2869 	nextrecord = m->m_nextpkt;
2870 	if (nextrecord == NULL) {
2871 		KASSERT(so->so_rcv.sb_lastrecord == m,
2872 		    ("soreceive_dgram: lastrecord != m"));
2873 	}
2874 
2875 	KASSERT(so->so_rcv.sb_mb->m_nextpkt == nextrecord,
2876 	    ("soreceive_dgram: m_nextpkt != nextrecord"));
2877 
2878 	/*
2879 	 * Pull 'm' and its chain off the front of the packet queue.
2880 	 */
2881 	so->so_rcv.sb_mb = NULL;
2882 	sockbuf_pushsync(&so->so_rcv, nextrecord);
2883 
2884 	/*
2885 	 * Walk 'm's chain and free that many bytes from the socket buffer.
2886 	 */
2887 	for (m2 = m; m2 != NULL; m2 = m2->m_next)
2888 		sbfree(&so->so_rcv, m2);
2889 
2890 	/*
2891 	 * Do a few last checks before we let go of the lock.
2892 	 */
2893 	SBLASTRECORDCHK(&so->so_rcv);
2894 	SBLASTMBUFCHK(&so->so_rcv);
2895 	SOCKBUF_UNLOCK(&so->so_rcv);
2896 
2897 	if (pr->pr_flags & PR_ADDR) {
2898 		KASSERT(m->m_type == MT_SONAME,
2899 		    ("m->m_type == %d", m->m_type));
2900 		if (psa != NULL)
2901 			*psa = sodupsockaddr(mtod(m, struct sockaddr *),
2902 			    M_WAITOK);
2903 		m = m_free(m);
2904 	}
2905 	KASSERT(m, ("%s: no data or control after soname", __func__));
2906 
2907 	/*
2908 	 * Packet to copyout() is now in 'm' and it is disconnected from the
2909 	 * queue.
2910 	 *
2911 	 * Process one or more MT_CONTROL mbufs present before any data mbufs
2912 	 * in the first mbuf chain on the socket buffer.  We call into the
2913 	 * protocol to perform externalization (or freeing if controlp ==
2914 	 * NULL). In some cases there can be only MT_CONTROL mbufs without
2915 	 * MT_DATA mbufs.
2916 	 */
2917 	if (m->m_type == MT_CONTROL) {
2918 		struct mbuf *cm = NULL, *cmn;
2919 		struct mbuf **cme = &cm;
2920 
2921 		do {
2922 			m2 = m->m_next;
2923 			m->m_next = NULL;
2924 			*cme = m;
2925 			cme = &(*cme)->m_next;
2926 			m = m2;
2927 		} while (m != NULL && m->m_type == MT_CONTROL);
2928 		while (cm != NULL) {
2929 			cmn = cm->m_next;
2930 			cm->m_next = NULL;
2931 			if (pr->pr_domain->dom_externalize != NULL) {
2932 				error = (*pr->pr_domain->dom_externalize)
2933 				    (cm, controlp, flags);
2934 			} else if (controlp != NULL)
2935 				*controlp = cm;
2936 			else
2937 				m_freem(cm);
2938 			if (controlp != NULL) {
2939 				while (*controlp != NULL)
2940 					controlp = &(*controlp)->m_next;
2941 			}
2942 			cm = cmn;
2943 		}
2944 	}
2945 	KASSERT(m == NULL || m->m_type == MT_DATA,
2946 	    ("soreceive_dgram: !data"));
2947 	while (m != NULL && uio->uio_resid > 0) {
2948 		len = uio->uio_resid;
2949 		if (len > m->m_len)
2950 			len = m->m_len;
2951 		error = uiomove(mtod(m, char *), (int)len, uio);
2952 		if (error) {
2953 			m_freem(m);
2954 			return (error);
2955 		}
2956 		if (len == m->m_len)
2957 			m = m_free(m);
2958 		else {
2959 			m->m_data += len;
2960 			m->m_len -= len;
2961 		}
2962 	}
2963 	if (m != NULL) {
2964 		flags |= MSG_TRUNC;
2965 		m_freem(m);
2966 	}
2967 	if (flagsp != NULL)
2968 		*flagsp |= flags;
2969 	return (0);
2970 }
2971 
2972 int
2973 soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
2974     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
2975 {
2976 	int error;
2977 
2978 	CURVNET_SET(so->so_vnet);
2979 	error = so->so_proto->pr_soreceive(so, psa, uio, mp0, controlp, flagsp);
2980 	CURVNET_RESTORE();
2981 	return (error);
2982 }
2983 
2984 int
2985 soshutdown(struct socket *so, enum shutdown_how how)
2986 {
2987 	int error;
2988 
2989 	CURVNET_SET(so->so_vnet);
2990 	error = so->so_proto->pr_shutdown(so, how);
2991 	CURVNET_RESTORE();
2992 
2993 	return (error);
2994 }
2995 
2996 /*
2997  * Used by several pr_shutdown implementations that use generic socket buffers.
2998  */
2999 void
3000 sorflush(struct socket *so)
3001 {
3002 	int error;
3003 
3004 	VNET_SO_ASSERT(so);
3005 
3006 	/*
3007 	 * Dislodge threads currently blocked in receive and wait to acquire
3008 	 * a lock against other simultaneous readers before clearing the
3009 	 * socket buffer.  Don't let our acquire be interrupted by a signal
3010 	 * despite any existing socket disposition on interruptable waiting.
3011 	 *
3012 	 * The SOCK_IO_RECV_LOCK() is important here as there some pr_soreceive
3013 	 * methods that read the top of the socket buffer without acquisition
3014 	 * of the socket buffer mutex, assuming that top of the buffer
3015 	 * exclusively belongs to the read(2) syscall.  This is handy when
3016 	 * performing MSG_PEEK.
3017 	 */
3018 	socantrcvmore(so);
3019 
3020 	error = SOCK_IO_RECV_LOCK(so, SBL_WAIT | SBL_NOINTR);
3021 	if (error != 0) {
3022 		KASSERT(SOLISTENING(so),
3023 		    ("%s: soiolock(%p) failed", __func__, so));
3024 		return;
3025 	}
3026 
3027 	sbrelease(so, SO_RCV);
3028 	SOCK_IO_RECV_UNLOCK(so);
3029 
3030 }
3031 
3032 #ifdef SOCKET_HHOOK
3033 /*
3034  * Wrapper for Socket established helper hook.
3035  * Parameters: socket, context of the hook point, hook id.
3036  */
3037 static inline int
3038 hhook_run_socket(struct socket *so, void *hctx, int32_t h_id)
3039 {
3040 	struct socket_hhook_data hhook_data = {
3041 		.so = so,
3042 		.hctx = hctx,
3043 		.m = NULL,
3044 		.status = 0
3045 	};
3046 
3047 	CURVNET_SET(so->so_vnet);
3048 	HHOOKS_RUN_IF(V_socket_hhh[h_id], &hhook_data, &so->osd);
3049 	CURVNET_RESTORE();
3050 
3051 	/* Ugly but needed, since hhooks return void for now */
3052 	return (hhook_data.status);
3053 }
3054 #endif
3055 
3056 /*
3057  * Perhaps this routine, and sooptcopyout(), below, ought to come in an
3058  * additional variant to handle the case where the option value needs to be
3059  * some kind of integer, but not a specific size.  In addition to their use
3060  * here, these functions are also called by the protocol-level pr_ctloutput()
3061  * routines.
3062  */
3063 int
3064 sooptcopyin(struct sockopt *sopt, void *buf, size_t len, size_t minlen)
3065 {
3066 	size_t	valsize;
3067 
3068 	/*
3069 	 * If the user gives us more than we wanted, we ignore it, but if we
3070 	 * don't get the minimum length the caller wants, we return EINVAL.
3071 	 * On success, sopt->sopt_valsize is set to however much we actually
3072 	 * retrieved.
3073 	 */
3074 	if ((valsize = sopt->sopt_valsize) < minlen)
3075 		return EINVAL;
3076 	if (valsize > len)
3077 		sopt->sopt_valsize = valsize = len;
3078 
3079 	if (sopt->sopt_td != NULL)
3080 		return (copyin(sopt->sopt_val, buf, valsize));
3081 
3082 	bcopy(sopt->sopt_val, buf, valsize);
3083 	return (0);
3084 }
3085 
3086 /*
3087  * Kernel version of setsockopt(2).
3088  *
3089  * XXX: optlen is size_t, not socklen_t
3090  */
3091 int
3092 so_setsockopt(struct socket *so, int level, int optname, void *optval,
3093     size_t optlen)
3094 {
3095 	struct sockopt sopt;
3096 
3097 	sopt.sopt_level = level;
3098 	sopt.sopt_name = optname;
3099 	sopt.sopt_dir = SOPT_SET;
3100 	sopt.sopt_val = optval;
3101 	sopt.sopt_valsize = optlen;
3102 	sopt.sopt_td = NULL;
3103 	return (sosetopt(so, &sopt));
3104 }
3105 
3106 int
3107 sosetopt(struct socket *so, struct sockopt *sopt)
3108 {
3109 	int	error, optval;
3110 	struct	linger l;
3111 	struct	timeval tv;
3112 	sbintime_t val, *valp;
3113 	uint32_t val32;
3114 #ifdef MAC
3115 	struct mac extmac;
3116 #endif
3117 
3118 	CURVNET_SET(so->so_vnet);
3119 	error = 0;
3120 	if (sopt->sopt_level != SOL_SOCKET) {
3121 		if (so->so_proto->pr_ctloutput != NULL)
3122 			error = (*so->so_proto->pr_ctloutput)(so, sopt);
3123 		else
3124 			error = ENOPROTOOPT;
3125 	} else {
3126 		switch (sopt->sopt_name) {
3127 		case SO_ACCEPTFILTER:
3128 			error = accept_filt_setopt(so, sopt);
3129 			if (error)
3130 				goto bad;
3131 			break;
3132 
3133 		case SO_LINGER:
3134 			error = sooptcopyin(sopt, &l, sizeof l, sizeof l);
3135 			if (error)
3136 				goto bad;
3137 			if (l.l_linger < 0 ||
3138 			    l.l_linger > USHRT_MAX ||
3139 			    l.l_linger > (INT_MAX / hz)) {
3140 				error = EDOM;
3141 				goto bad;
3142 			}
3143 			SOCK_LOCK(so);
3144 			so->so_linger = l.l_linger;
3145 			if (l.l_onoff)
3146 				so->so_options |= SO_LINGER;
3147 			else
3148 				so->so_options &= ~SO_LINGER;
3149 			SOCK_UNLOCK(so);
3150 			break;
3151 
3152 		case SO_DEBUG:
3153 		case SO_KEEPALIVE:
3154 		case SO_DONTROUTE:
3155 		case SO_USELOOPBACK:
3156 		case SO_BROADCAST:
3157 		case SO_REUSEADDR:
3158 		case SO_REUSEPORT:
3159 		case SO_REUSEPORT_LB:
3160 		case SO_OOBINLINE:
3161 		case SO_TIMESTAMP:
3162 		case SO_BINTIME:
3163 		case SO_NOSIGPIPE:
3164 		case SO_NO_DDP:
3165 		case SO_NO_OFFLOAD:
3166 		case SO_RERROR:
3167 			error = sooptcopyin(sopt, &optval, sizeof optval,
3168 			    sizeof optval);
3169 			if (error)
3170 				goto bad;
3171 			SOCK_LOCK(so);
3172 			if (optval)
3173 				so->so_options |= sopt->sopt_name;
3174 			else
3175 				so->so_options &= ~sopt->sopt_name;
3176 			SOCK_UNLOCK(so);
3177 			break;
3178 
3179 		case SO_SETFIB:
3180 			error = sooptcopyin(sopt, &optval, sizeof optval,
3181 			    sizeof optval);
3182 			if (error)
3183 				goto bad;
3184 
3185 			if (optval < 0 || optval >= rt_numfibs) {
3186 				error = EINVAL;
3187 				goto bad;
3188 			}
3189 			if (((so->so_proto->pr_domain->dom_family == PF_INET) ||
3190 			   (so->so_proto->pr_domain->dom_family == PF_INET6) ||
3191 			   (so->so_proto->pr_domain->dom_family == PF_ROUTE)))
3192 				so->so_fibnum = optval;
3193 			else
3194 				so->so_fibnum = 0;
3195 			break;
3196 
3197 		case SO_USER_COOKIE:
3198 			error = sooptcopyin(sopt, &val32, sizeof val32,
3199 			    sizeof val32);
3200 			if (error)
3201 				goto bad;
3202 			so->so_user_cookie = val32;
3203 			break;
3204 
3205 		case SO_SNDBUF:
3206 		case SO_RCVBUF:
3207 		case SO_SNDLOWAT:
3208 		case SO_RCVLOWAT:
3209 			error = so->so_proto->pr_setsbopt(so, sopt);
3210 			if (error)
3211 				goto bad;
3212 			break;
3213 
3214 		case SO_SNDTIMEO:
3215 		case SO_RCVTIMEO:
3216 #ifdef COMPAT_FREEBSD32
3217 			if (SV_CURPROC_FLAG(SV_ILP32)) {
3218 				struct timeval32 tv32;
3219 
3220 				error = sooptcopyin(sopt, &tv32, sizeof tv32,
3221 				    sizeof tv32);
3222 				CP(tv32, tv, tv_sec);
3223 				CP(tv32, tv, tv_usec);
3224 			} else
3225 #endif
3226 				error = sooptcopyin(sopt, &tv, sizeof tv,
3227 				    sizeof tv);
3228 			if (error)
3229 				goto bad;
3230 			if (tv.tv_sec < 0 || tv.tv_usec < 0 ||
3231 			    tv.tv_usec >= 1000000) {
3232 				error = EDOM;
3233 				goto bad;
3234 			}
3235 			if (tv.tv_sec > INT32_MAX)
3236 				val = SBT_MAX;
3237 			else
3238 				val = tvtosbt(tv);
3239 			SOCK_LOCK(so);
3240 			valp = sopt->sopt_name == SO_SNDTIMEO ?
3241 			    (SOLISTENING(so) ? &so->sol_sbsnd_timeo :
3242 			    &so->so_snd.sb_timeo) :
3243 			    (SOLISTENING(so) ? &so->sol_sbrcv_timeo :
3244 			    &so->so_rcv.sb_timeo);
3245 			*valp = val;
3246 			SOCK_UNLOCK(so);
3247 			break;
3248 
3249 		case SO_LABEL:
3250 #ifdef MAC
3251 			error = sooptcopyin(sopt, &extmac, sizeof extmac,
3252 			    sizeof extmac);
3253 			if (error)
3254 				goto bad;
3255 			error = mac_setsockopt_label(sopt->sopt_td->td_ucred,
3256 			    so, &extmac);
3257 #else
3258 			error = EOPNOTSUPP;
3259 #endif
3260 			break;
3261 
3262 		case SO_TS_CLOCK:
3263 			error = sooptcopyin(sopt, &optval, sizeof optval,
3264 			    sizeof optval);
3265 			if (error)
3266 				goto bad;
3267 			if (optval < 0 || optval > SO_TS_CLOCK_MAX) {
3268 				error = EINVAL;
3269 				goto bad;
3270 			}
3271 			so->so_ts_clock = optval;
3272 			break;
3273 
3274 		case SO_MAX_PACING_RATE:
3275 			error = sooptcopyin(sopt, &val32, sizeof(val32),
3276 			    sizeof(val32));
3277 			if (error)
3278 				goto bad;
3279 			so->so_max_pacing_rate = val32;
3280 			break;
3281 
3282 		default:
3283 #ifdef SOCKET_HHOOK
3284 			if (V_socket_hhh[HHOOK_SOCKET_OPT]->hhh_nhooks > 0)
3285 				error = hhook_run_socket(so, sopt,
3286 				    HHOOK_SOCKET_OPT);
3287 			else
3288 #endif
3289 				error = ENOPROTOOPT;
3290 			break;
3291 		}
3292 		if (error == 0 && so->so_proto->pr_ctloutput != NULL)
3293 			(void)(*so->so_proto->pr_ctloutput)(so, sopt);
3294 	}
3295 bad:
3296 	CURVNET_RESTORE();
3297 	return (error);
3298 }
3299 
3300 /*
3301  * Helper routine for getsockopt.
3302  */
3303 int
3304 sooptcopyout(struct sockopt *sopt, const void *buf, size_t len)
3305 {
3306 	int	error;
3307 	size_t	valsize;
3308 
3309 	error = 0;
3310 
3311 	/*
3312 	 * Documented get behavior is that we always return a value, possibly
3313 	 * truncated to fit in the user's buffer.  Traditional behavior is
3314 	 * that we always tell the user precisely how much we copied, rather
3315 	 * than something useful like the total amount we had available for
3316 	 * her.  Note that this interface is not idempotent; the entire
3317 	 * answer must be generated ahead of time.
3318 	 */
3319 	valsize = min(len, sopt->sopt_valsize);
3320 	sopt->sopt_valsize = valsize;
3321 	if (sopt->sopt_val != NULL) {
3322 		if (sopt->sopt_td != NULL)
3323 			error = copyout(buf, sopt->sopt_val, valsize);
3324 		else
3325 			bcopy(buf, sopt->sopt_val, valsize);
3326 	}
3327 	return (error);
3328 }
3329 
3330 int
3331 sogetopt(struct socket *so, struct sockopt *sopt)
3332 {
3333 	int	error, optval;
3334 	struct	linger l;
3335 	struct	timeval tv;
3336 #ifdef MAC
3337 	struct mac extmac;
3338 #endif
3339 
3340 	CURVNET_SET(so->so_vnet);
3341 	error = 0;
3342 	if (sopt->sopt_level != SOL_SOCKET) {
3343 		if (so->so_proto->pr_ctloutput != NULL)
3344 			error = (*so->so_proto->pr_ctloutput)(so, sopt);
3345 		else
3346 			error = ENOPROTOOPT;
3347 		CURVNET_RESTORE();
3348 		return (error);
3349 	} else {
3350 		switch (sopt->sopt_name) {
3351 		case SO_ACCEPTFILTER:
3352 			error = accept_filt_getopt(so, sopt);
3353 			break;
3354 
3355 		case SO_LINGER:
3356 			SOCK_LOCK(so);
3357 			l.l_onoff = so->so_options & SO_LINGER;
3358 			l.l_linger = so->so_linger;
3359 			SOCK_UNLOCK(so);
3360 			error = sooptcopyout(sopt, &l, sizeof l);
3361 			break;
3362 
3363 		case SO_USELOOPBACK:
3364 		case SO_DONTROUTE:
3365 		case SO_DEBUG:
3366 		case SO_KEEPALIVE:
3367 		case SO_REUSEADDR:
3368 		case SO_REUSEPORT:
3369 		case SO_REUSEPORT_LB:
3370 		case SO_BROADCAST:
3371 		case SO_OOBINLINE:
3372 		case SO_ACCEPTCONN:
3373 		case SO_TIMESTAMP:
3374 		case SO_BINTIME:
3375 		case SO_NOSIGPIPE:
3376 		case SO_NO_DDP:
3377 		case SO_NO_OFFLOAD:
3378 		case SO_RERROR:
3379 			optval = so->so_options & sopt->sopt_name;
3380 integer:
3381 			error = sooptcopyout(sopt, &optval, sizeof optval);
3382 			break;
3383 
3384 		case SO_DOMAIN:
3385 			optval = so->so_proto->pr_domain->dom_family;
3386 			goto integer;
3387 
3388 		case SO_TYPE:
3389 			optval = so->so_type;
3390 			goto integer;
3391 
3392 		case SO_PROTOCOL:
3393 			optval = so->so_proto->pr_protocol;
3394 			goto integer;
3395 
3396 		case SO_ERROR:
3397 			SOCK_LOCK(so);
3398 			if (so->so_error) {
3399 				optval = so->so_error;
3400 				so->so_error = 0;
3401 			} else {
3402 				optval = so->so_rerror;
3403 				so->so_rerror = 0;
3404 			}
3405 			SOCK_UNLOCK(so);
3406 			goto integer;
3407 
3408 		case SO_SNDBUF:
3409 			optval = SOLISTENING(so) ? so->sol_sbsnd_hiwat :
3410 			    so->so_snd.sb_hiwat;
3411 			goto integer;
3412 
3413 		case SO_RCVBUF:
3414 			optval = SOLISTENING(so) ? so->sol_sbrcv_hiwat :
3415 			    so->so_rcv.sb_hiwat;
3416 			goto integer;
3417 
3418 		case SO_SNDLOWAT:
3419 			optval = SOLISTENING(so) ? so->sol_sbsnd_lowat :
3420 			    so->so_snd.sb_lowat;
3421 			goto integer;
3422 
3423 		case SO_RCVLOWAT:
3424 			optval = SOLISTENING(so) ? so->sol_sbrcv_lowat :
3425 			    so->so_rcv.sb_lowat;
3426 			goto integer;
3427 
3428 		case SO_SNDTIMEO:
3429 		case SO_RCVTIMEO:
3430 			SOCK_LOCK(so);
3431 			tv = sbttotv(sopt->sopt_name == SO_SNDTIMEO ?
3432 			    (SOLISTENING(so) ? so->sol_sbsnd_timeo :
3433 			    so->so_snd.sb_timeo) :
3434 			    (SOLISTENING(so) ? so->sol_sbrcv_timeo :
3435 			    so->so_rcv.sb_timeo));
3436 			SOCK_UNLOCK(so);
3437 #ifdef COMPAT_FREEBSD32
3438 			if (SV_CURPROC_FLAG(SV_ILP32)) {
3439 				struct timeval32 tv32;
3440 
3441 				CP(tv, tv32, tv_sec);
3442 				CP(tv, tv32, tv_usec);
3443 				error = sooptcopyout(sopt, &tv32, sizeof tv32);
3444 			} else
3445 #endif
3446 				error = sooptcopyout(sopt, &tv, sizeof tv);
3447 			break;
3448 
3449 		case SO_LABEL:
3450 #ifdef MAC
3451 			error = sooptcopyin(sopt, &extmac, sizeof(extmac),
3452 			    sizeof(extmac));
3453 			if (error)
3454 				goto bad;
3455 			error = mac_getsockopt_label(sopt->sopt_td->td_ucred,
3456 			    so, &extmac);
3457 			if (error)
3458 				goto bad;
3459 			/* Don't copy out extmac, it is unchanged. */
3460 #else
3461 			error = EOPNOTSUPP;
3462 #endif
3463 			break;
3464 
3465 		case SO_PEERLABEL:
3466 #ifdef MAC
3467 			error = sooptcopyin(sopt, &extmac, sizeof(extmac),
3468 			    sizeof(extmac));
3469 			if (error)
3470 				goto bad;
3471 			error = mac_getsockopt_peerlabel(
3472 			    sopt->sopt_td->td_ucred, so, &extmac);
3473 			if (error)
3474 				goto bad;
3475 			/* Don't copy out extmac, it is unchanged. */
3476 #else
3477 			error = EOPNOTSUPP;
3478 #endif
3479 			break;
3480 
3481 		case SO_LISTENQLIMIT:
3482 			optval = SOLISTENING(so) ? so->sol_qlimit : 0;
3483 			goto integer;
3484 
3485 		case SO_LISTENQLEN:
3486 			optval = SOLISTENING(so) ? so->sol_qlen : 0;
3487 			goto integer;
3488 
3489 		case SO_LISTENINCQLEN:
3490 			optval = SOLISTENING(so) ? so->sol_incqlen : 0;
3491 			goto integer;
3492 
3493 		case SO_TS_CLOCK:
3494 			optval = so->so_ts_clock;
3495 			goto integer;
3496 
3497 		case SO_MAX_PACING_RATE:
3498 			optval = so->so_max_pacing_rate;
3499 			goto integer;
3500 
3501 		default:
3502 #ifdef SOCKET_HHOOK
3503 			if (V_socket_hhh[HHOOK_SOCKET_OPT]->hhh_nhooks > 0)
3504 				error = hhook_run_socket(so, sopt,
3505 				    HHOOK_SOCKET_OPT);
3506 			else
3507 #endif
3508 				error = ENOPROTOOPT;
3509 			break;
3510 		}
3511 	}
3512 #ifdef MAC
3513 bad:
3514 #endif
3515 	CURVNET_RESTORE();
3516 	return (error);
3517 }
3518 
3519 int
3520 soopt_getm(struct sockopt *sopt, struct mbuf **mp)
3521 {
3522 	struct mbuf *m, *m_prev;
3523 	int sopt_size = sopt->sopt_valsize;
3524 
3525 	MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
3526 	if (m == NULL)
3527 		return ENOBUFS;
3528 	if (sopt_size > MLEN) {
3529 		MCLGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT);
3530 		if ((m->m_flags & M_EXT) == 0) {
3531 			m_free(m);
3532 			return ENOBUFS;
3533 		}
3534 		m->m_len = min(MCLBYTES, sopt_size);
3535 	} else {
3536 		m->m_len = min(MLEN, sopt_size);
3537 	}
3538 	sopt_size -= m->m_len;
3539 	*mp = m;
3540 	m_prev = m;
3541 
3542 	while (sopt_size) {
3543 		MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
3544 		if (m == NULL) {
3545 			m_freem(*mp);
3546 			return ENOBUFS;
3547 		}
3548 		if (sopt_size > MLEN) {
3549 			MCLGET(m, sopt->sopt_td != NULL ? M_WAITOK :
3550 			    M_NOWAIT);
3551 			if ((m->m_flags & M_EXT) == 0) {
3552 				m_freem(m);
3553 				m_freem(*mp);
3554 				return ENOBUFS;
3555 			}
3556 			m->m_len = min(MCLBYTES, sopt_size);
3557 		} else {
3558 			m->m_len = min(MLEN, sopt_size);
3559 		}
3560 		sopt_size -= m->m_len;
3561 		m_prev->m_next = m;
3562 		m_prev = m;
3563 	}
3564 	return (0);
3565 }
3566 
3567 int
3568 soopt_mcopyin(struct sockopt *sopt, struct mbuf *m)
3569 {
3570 	struct mbuf *m0 = m;
3571 
3572 	if (sopt->sopt_val == NULL)
3573 		return (0);
3574 	while (m != NULL && sopt->sopt_valsize >= m->m_len) {
3575 		if (sopt->sopt_td != NULL) {
3576 			int error;
3577 
3578 			error = copyin(sopt->sopt_val, mtod(m, char *),
3579 			    m->m_len);
3580 			if (error != 0) {
3581 				m_freem(m0);
3582 				return(error);
3583 			}
3584 		} else
3585 			bcopy(sopt->sopt_val, mtod(m, char *), m->m_len);
3586 		sopt->sopt_valsize -= m->m_len;
3587 		sopt->sopt_val = (char *)sopt->sopt_val + m->m_len;
3588 		m = m->m_next;
3589 	}
3590 	if (m != NULL) /* should be allocated enoughly at ip6_sooptmcopyin() */
3591 		panic("ip6_sooptmcopyin");
3592 	return (0);
3593 }
3594 
3595 int
3596 soopt_mcopyout(struct sockopt *sopt, struct mbuf *m)
3597 {
3598 	struct mbuf *m0 = m;
3599 	size_t valsize = 0;
3600 
3601 	if (sopt->sopt_val == NULL)
3602 		return (0);
3603 	while (m != NULL && sopt->sopt_valsize >= m->m_len) {
3604 		if (sopt->sopt_td != NULL) {
3605 			int error;
3606 
3607 			error = copyout(mtod(m, char *), sopt->sopt_val,
3608 			    m->m_len);
3609 			if (error != 0) {
3610 				m_freem(m0);
3611 				return(error);
3612 			}
3613 		} else
3614 			bcopy(mtod(m, char *), sopt->sopt_val, m->m_len);
3615 		sopt->sopt_valsize -= m->m_len;
3616 		sopt->sopt_val = (char *)sopt->sopt_val + m->m_len;
3617 		valsize += m->m_len;
3618 		m = m->m_next;
3619 	}
3620 	if (m != NULL) {
3621 		/* enough soopt buffer should be given from user-land */
3622 		m_freem(m0);
3623 		return(EINVAL);
3624 	}
3625 	sopt->sopt_valsize = valsize;
3626 	return (0);
3627 }
3628 
3629 /*
3630  * sohasoutofband(): protocol notifies socket layer of the arrival of new
3631  * out-of-band data, which will then notify socket consumers.
3632  */
3633 void
3634 sohasoutofband(struct socket *so)
3635 {
3636 
3637 	if (so->so_sigio != NULL)
3638 		pgsigio(&so->so_sigio, SIGURG, 0);
3639 	selwakeuppri(&so->so_rdsel, PSOCK);
3640 }
3641 
3642 int
3643 sopoll(struct socket *so, int events, struct ucred *active_cred,
3644     struct thread *td)
3645 {
3646 
3647 	/*
3648 	 * We do not need to set or assert curvnet as long as everyone uses
3649 	 * sopoll_generic().
3650 	 */
3651 	return (so->so_proto->pr_sopoll(so, events, active_cred, td));
3652 }
3653 
3654 int
3655 sopoll_generic(struct socket *so, int events, struct ucred *active_cred,
3656     struct thread *td)
3657 {
3658 	int revents;
3659 
3660 	SOCK_LOCK(so);
3661 	if (SOLISTENING(so)) {
3662 		if (!(events & (POLLIN | POLLRDNORM)))
3663 			revents = 0;
3664 		else if (!TAILQ_EMPTY(&so->sol_comp))
3665 			revents = events & (POLLIN | POLLRDNORM);
3666 		else if ((events & POLLINIGNEOF) == 0 && so->so_error)
3667 			revents = (events & (POLLIN | POLLRDNORM)) | POLLHUP;
3668 		else {
3669 			selrecord(td, &so->so_rdsel);
3670 			revents = 0;
3671 		}
3672 	} else {
3673 		revents = 0;
3674 		SOCK_SENDBUF_LOCK(so);
3675 		SOCK_RECVBUF_LOCK(so);
3676 		if (events & (POLLIN | POLLRDNORM))
3677 			if (soreadabledata(so))
3678 				revents |= events & (POLLIN | POLLRDNORM);
3679 		if (events & (POLLOUT | POLLWRNORM))
3680 			if (sowriteable(so))
3681 				revents |= events & (POLLOUT | POLLWRNORM);
3682 		if (events & (POLLPRI | POLLRDBAND))
3683 			if (so->so_oobmark ||
3684 			    (so->so_rcv.sb_state & SBS_RCVATMARK))
3685 				revents |= events & (POLLPRI | POLLRDBAND);
3686 		if ((events & POLLINIGNEOF) == 0) {
3687 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
3688 				revents |= events & (POLLIN | POLLRDNORM);
3689 				if (so->so_snd.sb_state & SBS_CANTSENDMORE)
3690 					revents |= POLLHUP;
3691 			}
3692 		}
3693 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE)
3694 			revents |= events & POLLRDHUP;
3695 		if (revents == 0) {
3696 			if (events &
3697 			    (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND | POLLRDHUP)) {
3698 				selrecord(td, &so->so_rdsel);
3699 				so->so_rcv.sb_flags |= SB_SEL;
3700 			}
3701 			if (events & (POLLOUT | POLLWRNORM)) {
3702 				selrecord(td, &so->so_wrsel);
3703 				so->so_snd.sb_flags |= SB_SEL;
3704 			}
3705 		}
3706 		SOCK_RECVBUF_UNLOCK(so);
3707 		SOCK_SENDBUF_UNLOCK(so);
3708 	}
3709 	SOCK_UNLOCK(so);
3710 	return (revents);
3711 }
3712 
3713 int
3714 soo_kqfilter(struct file *fp, struct knote *kn)
3715 {
3716 	struct socket *so = kn->kn_fp->f_data;
3717 	struct sockbuf *sb;
3718 	sb_which which;
3719 	struct knlist *knl;
3720 
3721 	switch (kn->kn_filter) {
3722 	case EVFILT_READ:
3723 		kn->kn_fop = &soread_filtops;
3724 		knl = &so->so_rdsel.si_note;
3725 		sb = &so->so_rcv;
3726 		which = SO_RCV;
3727 		break;
3728 	case EVFILT_WRITE:
3729 		kn->kn_fop = &sowrite_filtops;
3730 		knl = &so->so_wrsel.si_note;
3731 		sb = &so->so_snd;
3732 		which = SO_SND;
3733 		break;
3734 	case EVFILT_EMPTY:
3735 		kn->kn_fop = &soempty_filtops;
3736 		knl = &so->so_wrsel.si_note;
3737 		sb = &so->so_snd;
3738 		which = SO_SND;
3739 		break;
3740 	default:
3741 		return (EINVAL);
3742 	}
3743 
3744 	SOCK_LOCK(so);
3745 	if (SOLISTENING(so)) {
3746 		knlist_add(knl, kn, 1);
3747 	} else {
3748 		SOCK_BUF_LOCK(so, which);
3749 		knlist_add(knl, kn, 1);
3750 		sb->sb_flags |= SB_KNOTE;
3751 		SOCK_BUF_UNLOCK(so, which);
3752 	}
3753 	SOCK_UNLOCK(so);
3754 	return (0);
3755 }
3756 
3757 static void
3758 filt_sordetach(struct knote *kn)
3759 {
3760 	struct socket *so = kn->kn_fp->f_data;
3761 
3762 	so_rdknl_lock(so);
3763 	knlist_remove(&so->so_rdsel.si_note, kn, 1);
3764 	if (!SOLISTENING(so) && knlist_empty(&so->so_rdsel.si_note))
3765 		so->so_rcv.sb_flags &= ~SB_KNOTE;
3766 	so_rdknl_unlock(so);
3767 }
3768 
3769 /*ARGSUSED*/
3770 static int
3771 filt_soread(struct knote *kn, long hint)
3772 {
3773 	struct socket *so;
3774 
3775 	so = kn->kn_fp->f_data;
3776 
3777 	if (SOLISTENING(so)) {
3778 		SOCK_LOCK_ASSERT(so);
3779 		kn->kn_data = so->sol_qlen;
3780 		if (so->so_error) {
3781 			kn->kn_flags |= EV_EOF;
3782 			kn->kn_fflags = so->so_error;
3783 			return (1);
3784 		}
3785 		return (!TAILQ_EMPTY(&so->sol_comp));
3786 	}
3787 
3788 	SOCK_RECVBUF_LOCK_ASSERT(so);
3789 
3790 	kn->kn_data = sbavail(&so->so_rcv) - so->so_rcv.sb_ctl;
3791 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
3792 		kn->kn_flags |= EV_EOF;
3793 		kn->kn_fflags = so->so_error;
3794 		return (1);
3795 	} else if (so->so_error || so->so_rerror)
3796 		return (1);
3797 
3798 	if (kn->kn_sfflags & NOTE_LOWAT) {
3799 		if (kn->kn_data >= kn->kn_sdata)
3800 			return (1);
3801 	} else if (sbavail(&so->so_rcv) >= so->so_rcv.sb_lowat)
3802 		return (1);
3803 
3804 #ifdef SOCKET_HHOOK
3805 	/* This hook returning non-zero indicates an event, not error */
3806 	return (hhook_run_socket(so, NULL, HHOOK_FILT_SOREAD));
3807 #else
3808 	return (0);
3809 #endif
3810 }
3811 
3812 static void
3813 filt_sowdetach(struct knote *kn)
3814 {
3815 	struct socket *so = kn->kn_fp->f_data;
3816 
3817 	so_wrknl_lock(so);
3818 	knlist_remove(&so->so_wrsel.si_note, kn, 1);
3819 	if (!SOLISTENING(so) && knlist_empty(&so->so_wrsel.si_note))
3820 		so->so_snd.sb_flags &= ~SB_KNOTE;
3821 	so_wrknl_unlock(so);
3822 }
3823 
3824 /*ARGSUSED*/
3825 static int
3826 filt_sowrite(struct knote *kn, long hint)
3827 {
3828 	struct socket *so;
3829 
3830 	so = kn->kn_fp->f_data;
3831 
3832 	if (SOLISTENING(so))
3833 		return (0);
3834 
3835 	SOCK_SENDBUF_LOCK_ASSERT(so);
3836 	kn->kn_data = sbspace(&so->so_snd);
3837 
3838 #ifdef SOCKET_HHOOK
3839 	hhook_run_socket(so, kn, HHOOK_FILT_SOWRITE);
3840 #endif
3841 
3842 	if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
3843 		kn->kn_flags |= EV_EOF;
3844 		kn->kn_fflags = so->so_error;
3845 		return (1);
3846 	} else if (so->so_error)	/* temporary udp error */
3847 		return (1);
3848 	else if (((so->so_state & SS_ISCONNECTED) == 0) &&
3849 	    (so->so_proto->pr_flags & PR_CONNREQUIRED))
3850 		return (0);
3851 	else if (kn->kn_sfflags & NOTE_LOWAT)
3852 		return (kn->kn_data >= kn->kn_sdata);
3853 	else
3854 		return (kn->kn_data >= so->so_snd.sb_lowat);
3855 }
3856 
3857 static int
3858 filt_soempty(struct knote *kn, long hint)
3859 {
3860 	struct socket *so;
3861 
3862 	so = kn->kn_fp->f_data;
3863 
3864 	if (SOLISTENING(so))
3865 		return (1);
3866 
3867 	SOCK_SENDBUF_LOCK_ASSERT(so);
3868 	kn->kn_data = sbused(&so->so_snd);
3869 
3870 	if (kn->kn_data == 0)
3871 		return (1);
3872 	else
3873 		return (0);
3874 }
3875 
3876 int
3877 socheckuid(struct socket *so, uid_t uid)
3878 {
3879 
3880 	if (so == NULL)
3881 		return (EPERM);
3882 	if (so->so_cred->cr_uid != uid)
3883 		return (EPERM);
3884 	return (0);
3885 }
3886 
3887 /*
3888  * These functions are used by protocols to notify the socket layer (and its
3889  * consumers) of state changes in the sockets driven by protocol-side events.
3890  */
3891 
3892 /*
3893  * Procedures to manipulate state flags of socket and do appropriate wakeups.
3894  *
3895  * Normal sequence from the active (originating) side is that
3896  * soisconnecting() is called during processing of connect() call, resulting
3897  * in an eventual call to soisconnected() if/when the connection is
3898  * established.  When the connection is torn down soisdisconnecting() is
3899  * called during processing of disconnect() call, and soisdisconnected() is
3900  * called when the connection to the peer is totally severed.  The semantics
3901  * of these routines are such that connectionless protocols can call
3902  * soisconnected() and soisdisconnected() only, bypassing the in-progress
3903  * calls when setting up a ``connection'' takes no time.
3904  *
3905  * From the passive side, a socket is created with two queues of sockets:
3906  * so_incomp for connections in progress and so_comp for connections already
3907  * made and awaiting user acceptance.  As a protocol is preparing incoming
3908  * connections, it creates a socket structure queued on so_incomp by calling
3909  * sonewconn().  When the connection is established, soisconnected() is
3910  * called, and transfers the socket structure to so_comp, making it available
3911  * to accept().
3912  *
3913  * If a socket is closed with sockets on either so_incomp or so_comp, these
3914  * sockets are dropped.
3915  *
3916  * If higher-level protocols are implemented in the kernel, the wakeups done
3917  * here will sometimes cause software-interrupt process scheduling.
3918  */
3919 void
3920 soisconnecting(struct socket *so)
3921 {
3922 
3923 	SOCK_LOCK(so);
3924 	so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING);
3925 	so->so_state |= SS_ISCONNECTING;
3926 	SOCK_UNLOCK(so);
3927 }
3928 
3929 void
3930 soisconnected(struct socket *so)
3931 {
3932 	bool last __diagused;
3933 
3934 	SOCK_LOCK(so);
3935 	so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING);
3936 	so->so_state |= SS_ISCONNECTED;
3937 
3938 	if (so->so_qstate == SQ_INCOMP) {
3939 		struct socket *head = so->so_listen;
3940 		int ret;
3941 
3942 		KASSERT(head, ("%s: so %p on incomp of NULL", __func__, so));
3943 		/*
3944 		 * Promoting a socket from incomplete queue to complete, we
3945 		 * need to go through reverse order of locking.  We first do
3946 		 * trylock, and if that doesn't succeed, we go the hard way
3947 		 * leaving a reference and rechecking consistency after proper
3948 		 * locking.
3949 		 */
3950 		if (__predict_false(SOLISTEN_TRYLOCK(head) == 0)) {
3951 			soref(head);
3952 			SOCK_UNLOCK(so);
3953 			SOLISTEN_LOCK(head);
3954 			SOCK_LOCK(so);
3955 			if (__predict_false(head != so->so_listen)) {
3956 				/*
3957 				 * The socket went off the listen queue,
3958 				 * should be lost race to close(2) of sol.
3959 				 * The socket is about to soabort().
3960 				 */
3961 				SOCK_UNLOCK(so);
3962 				sorele_locked(head);
3963 				return;
3964 			}
3965 			last = refcount_release(&head->so_count);
3966 			KASSERT(!last, ("%s: released last reference for %p",
3967 			    __func__, head));
3968 		}
3969 again:
3970 		if ((so->so_options & SO_ACCEPTFILTER) == 0) {
3971 			TAILQ_REMOVE(&head->sol_incomp, so, so_list);
3972 			head->sol_incqlen--;
3973 			TAILQ_INSERT_TAIL(&head->sol_comp, so, so_list);
3974 			head->sol_qlen++;
3975 			so->so_qstate = SQ_COMP;
3976 			SOCK_UNLOCK(so);
3977 			solisten_wakeup(head);	/* unlocks */
3978 		} else {
3979 			SOCK_RECVBUF_LOCK(so);
3980 			soupcall_set(so, SO_RCV,
3981 			    head->sol_accept_filter->accf_callback,
3982 			    head->sol_accept_filter_arg);
3983 			so->so_options &= ~SO_ACCEPTFILTER;
3984 			ret = head->sol_accept_filter->accf_callback(so,
3985 			    head->sol_accept_filter_arg, M_NOWAIT);
3986 			if (ret == SU_ISCONNECTED) {
3987 				soupcall_clear(so, SO_RCV);
3988 				SOCK_RECVBUF_UNLOCK(so);
3989 				goto again;
3990 			}
3991 			SOCK_RECVBUF_UNLOCK(so);
3992 			SOCK_UNLOCK(so);
3993 			SOLISTEN_UNLOCK(head);
3994 		}
3995 		return;
3996 	}
3997 	SOCK_UNLOCK(so);
3998 	wakeup(&so->so_timeo);
3999 	sorwakeup(so);
4000 	sowwakeup(so);
4001 }
4002 
4003 void
4004 soisdisconnecting(struct socket *so)
4005 {
4006 
4007 	SOCK_LOCK(so);
4008 	so->so_state &= ~SS_ISCONNECTING;
4009 	so->so_state |= SS_ISDISCONNECTING;
4010 
4011 	if (!SOLISTENING(so)) {
4012 		SOCK_RECVBUF_LOCK(so);
4013 		socantrcvmore_locked(so);
4014 		SOCK_SENDBUF_LOCK(so);
4015 		socantsendmore_locked(so);
4016 	}
4017 	SOCK_UNLOCK(so);
4018 	wakeup(&so->so_timeo);
4019 }
4020 
4021 void
4022 soisdisconnected(struct socket *so)
4023 {
4024 
4025 	SOCK_LOCK(so);
4026 
4027 	/*
4028 	 * There is at least one reader of so_state that does not
4029 	 * acquire socket lock, namely soreceive_generic().  Ensure
4030 	 * that it never sees all flags that track connection status
4031 	 * cleared, by ordering the update with a barrier semantic of
4032 	 * our release thread fence.
4033 	 */
4034 	so->so_state |= SS_ISDISCONNECTED;
4035 	atomic_thread_fence_rel();
4036 	so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING);
4037 
4038 	if (!SOLISTENING(so)) {
4039 		SOCK_UNLOCK(so);
4040 		SOCK_RECVBUF_LOCK(so);
4041 		socantrcvmore_locked(so);
4042 		SOCK_SENDBUF_LOCK(so);
4043 		sbdrop_locked(&so->so_snd, sbused(&so->so_snd));
4044 		socantsendmore_locked(so);
4045 	} else
4046 		SOCK_UNLOCK(so);
4047 	wakeup(&so->so_timeo);
4048 }
4049 
4050 int
4051 soiolock(struct socket *so, struct sx *sx, int flags)
4052 {
4053 	int error;
4054 
4055 	KASSERT((flags & SBL_VALID) == flags,
4056 	    ("soiolock: invalid flags %#x", flags));
4057 
4058 	if ((flags & SBL_WAIT) != 0) {
4059 		if ((flags & SBL_NOINTR) != 0) {
4060 			sx_xlock(sx);
4061 		} else {
4062 			error = sx_xlock_sig(sx);
4063 			if (error != 0)
4064 				return (error);
4065 		}
4066 	} else if (!sx_try_xlock(sx)) {
4067 		return (EWOULDBLOCK);
4068 	}
4069 
4070 	if (__predict_false(SOLISTENING(so))) {
4071 		sx_xunlock(sx);
4072 		return (ENOTCONN);
4073 	}
4074 	return (0);
4075 }
4076 
4077 void
4078 soiounlock(struct sx *sx)
4079 {
4080 	sx_xunlock(sx);
4081 }
4082 
4083 /*
4084  * Make a copy of a sockaddr in a malloced buffer of type M_SONAME.
4085  */
4086 struct sockaddr *
4087 sodupsockaddr(const struct sockaddr *sa, int mflags)
4088 {
4089 	struct sockaddr *sa2;
4090 
4091 	sa2 = malloc(sa->sa_len, M_SONAME, mflags);
4092 	if (sa2)
4093 		bcopy(sa, sa2, sa->sa_len);
4094 	return sa2;
4095 }
4096 
4097 /*
4098  * Register per-socket destructor.
4099  */
4100 void
4101 sodtor_set(struct socket *so, so_dtor_t *func)
4102 {
4103 
4104 	SOCK_LOCK_ASSERT(so);
4105 	so->so_dtor = func;
4106 }
4107 
4108 /*
4109  * Register per-socket buffer upcalls.
4110  */
4111 void
4112 soupcall_set(struct socket *so, sb_which which, so_upcall_t func, void *arg)
4113 {
4114 	struct sockbuf *sb;
4115 
4116 	KASSERT(!SOLISTENING(so), ("%s: so %p listening", __func__, so));
4117 
4118 	switch (which) {
4119 	case SO_RCV:
4120 		sb = &so->so_rcv;
4121 		break;
4122 	case SO_SND:
4123 		sb = &so->so_snd;
4124 		break;
4125 	}
4126 	SOCK_BUF_LOCK_ASSERT(so, which);
4127 	sb->sb_upcall = func;
4128 	sb->sb_upcallarg = arg;
4129 	sb->sb_flags |= SB_UPCALL;
4130 }
4131 
4132 void
4133 soupcall_clear(struct socket *so, sb_which which)
4134 {
4135 	struct sockbuf *sb;
4136 
4137 	KASSERT(!SOLISTENING(so), ("%s: so %p listening", __func__, so));
4138 
4139 	switch (which) {
4140 	case SO_RCV:
4141 		sb = &so->so_rcv;
4142 		break;
4143 	case SO_SND:
4144 		sb = &so->so_snd;
4145 		break;
4146 	}
4147 	SOCK_BUF_LOCK_ASSERT(so, which);
4148 	KASSERT(sb->sb_upcall != NULL,
4149 	    ("%s: so %p no upcall to clear", __func__, so));
4150 	sb->sb_upcall = NULL;
4151 	sb->sb_upcallarg = NULL;
4152 	sb->sb_flags &= ~SB_UPCALL;
4153 }
4154 
4155 void
4156 solisten_upcall_set(struct socket *so, so_upcall_t func, void *arg)
4157 {
4158 
4159 	SOLISTEN_LOCK_ASSERT(so);
4160 	so->sol_upcall = func;
4161 	so->sol_upcallarg = arg;
4162 }
4163 
4164 static void
4165 so_rdknl_lock(void *arg)
4166 {
4167 	struct socket *so = arg;
4168 
4169 retry:
4170 	if (SOLISTENING(so)) {
4171 		SOLISTEN_LOCK(so);
4172 	} else {
4173 		SOCK_RECVBUF_LOCK(so);
4174 		if (__predict_false(SOLISTENING(so))) {
4175 			SOCK_RECVBUF_UNLOCK(so);
4176 			goto retry;
4177 		}
4178 	}
4179 }
4180 
4181 static void
4182 so_rdknl_unlock(void *arg)
4183 {
4184 	struct socket *so = arg;
4185 
4186 	if (SOLISTENING(so))
4187 		SOLISTEN_UNLOCK(so);
4188 	else
4189 		SOCK_RECVBUF_UNLOCK(so);
4190 }
4191 
4192 static void
4193 so_rdknl_assert_lock(void *arg, int what)
4194 {
4195 	struct socket *so = arg;
4196 
4197 	if (what == LA_LOCKED) {
4198 		if (SOLISTENING(so))
4199 			SOLISTEN_LOCK_ASSERT(so);
4200 		else
4201 			SOCK_RECVBUF_LOCK_ASSERT(so);
4202 	} else {
4203 		if (SOLISTENING(so))
4204 			SOLISTEN_UNLOCK_ASSERT(so);
4205 		else
4206 			SOCK_RECVBUF_UNLOCK_ASSERT(so);
4207 	}
4208 }
4209 
4210 static void
4211 so_wrknl_lock(void *arg)
4212 {
4213 	struct socket *so = arg;
4214 
4215 retry:
4216 	if (SOLISTENING(so)) {
4217 		SOLISTEN_LOCK(so);
4218 	} else {
4219 		SOCK_SENDBUF_LOCK(so);
4220 		if (__predict_false(SOLISTENING(so))) {
4221 			SOCK_SENDBUF_UNLOCK(so);
4222 			goto retry;
4223 		}
4224 	}
4225 }
4226 
4227 static void
4228 so_wrknl_unlock(void *arg)
4229 {
4230 	struct socket *so = arg;
4231 
4232 	if (SOLISTENING(so))
4233 		SOLISTEN_UNLOCK(so);
4234 	else
4235 		SOCK_SENDBUF_UNLOCK(so);
4236 }
4237 
4238 static void
4239 so_wrknl_assert_lock(void *arg, int what)
4240 {
4241 	struct socket *so = arg;
4242 
4243 	if (what == LA_LOCKED) {
4244 		if (SOLISTENING(so))
4245 			SOLISTEN_LOCK_ASSERT(so);
4246 		else
4247 			SOCK_SENDBUF_LOCK_ASSERT(so);
4248 	} else {
4249 		if (SOLISTENING(so))
4250 			SOLISTEN_UNLOCK_ASSERT(so);
4251 		else
4252 			SOCK_SENDBUF_UNLOCK_ASSERT(so);
4253 	}
4254 }
4255 
4256 /*
4257  * Create an external-format (``xsocket'') structure using the information in
4258  * the kernel-format socket structure pointed to by so.  This is done to
4259  * reduce the spew of irrelevant information over this interface, to isolate
4260  * user code from changes in the kernel structure, and potentially to provide
4261  * information-hiding if we decide that some of this information should be
4262  * hidden from users.
4263  */
4264 void
4265 sotoxsocket(struct socket *so, struct xsocket *xso)
4266 {
4267 
4268 	bzero(xso, sizeof(*xso));
4269 	xso->xso_len = sizeof *xso;
4270 	xso->xso_so = (uintptr_t)so;
4271 	xso->so_type = so->so_type;
4272 	xso->so_options = so->so_options;
4273 	xso->so_linger = so->so_linger;
4274 	xso->so_state = so->so_state;
4275 	xso->so_pcb = (uintptr_t)so->so_pcb;
4276 	xso->xso_protocol = so->so_proto->pr_protocol;
4277 	xso->xso_family = so->so_proto->pr_domain->dom_family;
4278 	xso->so_timeo = so->so_timeo;
4279 	xso->so_error = so->so_error;
4280 	xso->so_uid = so->so_cred->cr_uid;
4281 	xso->so_pgid = so->so_sigio ? so->so_sigio->sio_pgid : 0;
4282 	if (SOLISTENING(so)) {
4283 		xso->so_qlen = so->sol_qlen;
4284 		xso->so_incqlen = so->sol_incqlen;
4285 		xso->so_qlimit = so->sol_qlimit;
4286 		xso->so_oobmark = 0;
4287 	} else {
4288 		xso->so_state |= so->so_qstate;
4289 		xso->so_qlen = xso->so_incqlen = xso->so_qlimit = 0;
4290 		xso->so_oobmark = so->so_oobmark;
4291 		sbtoxsockbuf(&so->so_snd, &xso->so_snd);
4292 		sbtoxsockbuf(&so->so_rcv, &xso->so_rcv);
4293 	}
4294 }
4295 
4296 int
4297 so_options_get(const struct socket *so)
4298 {
4299 
4300 	return (so->so_options);
4301 }
4302 
4303 void
4304 so_options_set(struct socket *so, int val)
4305 {
4306 
4307 	so->so_options = val;
4308 }
4309 
4310 int
4311 so_error_get(const struct socket *so)
4312 {
4313 
4314 	return (so->so_error);
4315 }
4316 
4317 void
4318 so_error_set(struct socket *so, int val)
4319 {
4320 
4321 	so->so_error = val;
4322 }
4323