xref: /openbsd-src/sys/kern/uipc_socket.c (revision c6ec13d01ead3cb21587769029671b30cdcfaa3b)
1 /*	$OpenBSD: uipc_socket.c,v 1.351 2024/12/30 12:12:35 mvs Exp $	*/
2 /*	$NetBSD: uipc_socket.c,v 1.21 1996/02/04 02:17:52 christos Exp $	*/
3 
4 /*
5  * Copyright (c) 1982, 1986, 1988, 1990, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)uipc_socket.c	8.3 (Berkeley) 4/15/94
33  */
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/proc.h>
38 #include <sys/file.h>
39 #include <sys/filedesc.h>
40 #include <sys/malloc.h>
41 #include <sys/mbuf.h>
42 #include <sys/domain.h>
43 #include <sys/event.h>
44 #include <sys/protosw.h>
45 #include <sys/socket.h>
46 #include <sys/unpcb.h>
47 #include <sys/socketvar.h>
48 #include <sys/signalvar.h>
49 #include <sys/pool.h>
50 #include <sys/atomic.h>
51 #include <sys/rwlock.h>
52 #include <sys/time.h>
53 #include <sys/refcnt.h>
54 
55 #ifdef DDB
56 #include <machine/db_machdep.h>
57 #endif
58 
59 void	sbsync(struct sockbuf *, struct mbuf *);
60 
61 int	sosplice(struct socket *, int, off_t, struct timeval *);
62 void	sounsplice(struct socket *, struct socket *, int);
63 void	soidle(void *);
64 void	sotask(void *);
65 int	somove(struct socket *, int);
66 void	sorflush(struct socket *);
67 
68 void	filt_sordetach(struct knote *kn);
69 int	filt_soread(struct knote *kn, long hint);
70 void	filt_sowdetach(struct knote *kn);
71 int	filt_sowrite(struct knote *kn, long hint);
72 int	filt_soexcept(struct knote *kn, long hint);
73 
74 int	filt_sowmodify(struct kevent *kev, struct knote *kn);
75 int	filt_sowprocess(struct knote *kn, struct kevent *kev);
76 
77 int	filt_sormodify(struct kevent *kev, struct knote *kn);
78 int	filt_sorprocess(struct knote *kn, struct kevent *kev);
79 
80 const struct filterops soread_filtops = {
81 	.f_flags	= FILTEROP_ISFD | FILTEROP_MPSAFE,
82 	.f_attach	= NULL,
83 	.f_detach	= filt_sordetach,
84 	.f_event	= filt_soread,
85 	.f_modify	= filt_sormodify,
86 	.f_process	= filt_sorprocess,
87 };
88 
89 const struct filterops sowrite_filtops = {
90 	.f_flags	= FILTEROP_ISFD | FILTEROP_MPSAFE,
91 	.f_attach	= NULL,
92 	.f_detach	= filt_sowdetach,
93 	.f_event	= filt_sowrite,
94 	.f_modify	= filt_sowmodify,
95 	.f_process	= filt_sowprocess,
96 };
97 
98 const struct filterops soexcept_filtops = {
99 	.f_flags	= FILTEROP_ISFD | FILTEROP_MPSAFE,
100 	.f_attach	= NULL,
101 	.f_detach	= filt_sordetach,
102 	.f_event	= filt_soexcept,
103 	.f_modify	= filt_sormodify,
104 	.f_process	= filt_sorprocess,
105 };
106 
107 #ifndef SOMINCONN
108 #define SOMINCONN 80
109 #endif /* SOMINCONN */
110 
111 int	somaxconn = SOMAXCONN;
112 int	sominconn = SOMINCONN;
113 
114 struct pool socket_pool;
115 #ifdef SOCKET_SPLICE
116 struct pool sosplice_pool;
117 struct taskq *sosplice_taskq;
118 struct rwlock sosplice_lock = RWLOCK_INITIALIZER("sosplicelk");
119 #endif
120 
121 void
122 soinit(void)
123 {
124 	pool_init(&socket_pool, sizeof(struct socket), 0, IPL_SOFTNET, 0,
125 	    "sockpl", NULL);
126 #ifdef SOCKET_SPLICE
127 	pool_init(&sosplice_pool, sizeof(struct sosplice), 0, IPL_SOFTNET, 0,
128 	    "sosppl", NULL);
129 #endif
130 }
131 
132 struct socket *
133 soalloc(const struct protosw *prp, int wait)
134 {
135 	const struct domain *dp = prp->pr_domain;
136 	struct socket *so;
137 
138 	so = pool_get(&socket_pool, (wait == M_WAIT ? PR_WAITOK : PR_NOWAIT) |
139 	    PR_ZERO);
140 	if (so == NULL)
141 		return (NULL);
142 	rw_init_flags(&so->so_lock, dp->dom_name, RWL_DUPOK);
143 	refcnt_init(&so->so_refcnt);
144 	rw_init(&so->so_rcv.sb_lock, "sbufrcv");
145 	rw_init(&so->so_snd.sb_lock, "sbufsnd");
146 	mtx_init_flags(&so->so_rcv.sb_mtx, IPL_MPFLOOR, "sbrcv", 0);
147 	mtx_init_flags(&so->so_snd.sb_mtx, IPL_MPFLOOR, "sbsnd", 0);
148 	klist_init_mutex(&so->so_rcv.sb_klist, &so->so_rcv.sb_mtx);
149 	klist_init_mutex(&so->so_snd.sb_klist, &so->so_snd.sb_mtx);
150 	sigio_init(&so->so_sigio);
151 	TAILQ_INIT(&so->so_q0);
152 	TAILQ_INIT(&so->so_q);
153 
154 	switch (dp->dom_family) {
155 	case AF_INET:
156 	case AF_INET6:
157 		switch (prp->pr_type) {
158 		case SOCK_RAW:
159 		case SOCK_DGRAM:
160 			so->so_snd.sb_flags |= SB_MTXLOCK;
161 			/* FALLTHROUGH */
162 		case SOCK_STREAM:
163 			so->so_rcv.sb_flags |= SB_MTXLOCK;
164 			break;
165 		}
166 		break;
167 	case AF_KEY:
168 	case AF_ROUTE:
169 	case AF_UNIX:
170 	case AF_FRAME:
171 		so->so_snd.sb_flags |= SB_MTXLOCK;
172 		so->so_rcv.sb_flags |= SB_MTXLOCK;
173 		break;
174 	}
175 
176 	return (so);
177 }
178 
179 /*
180  * Socket operation routines.
181  * These routines are called by the routines in
182  * sys_socket.c or from a system process, and
183  * implement the semantics of socket operations by
184  * switching out to the protocol specific routines.
185  */
186 int
187 socreate(int dom, struct socket **aso, int type, int proto)
188 {
189 	struct proc *p = curproc;		/* XXX */
190 	const struct protosw *prp;
191 	struct socket *so;
192 	int error;
193 
194 	if (proto)
195 		prp = pffindproto(dom, proto, type);
196 	else
197 		prp = pffindtype(dom, type);
198 	if (prp == NULL || prp->pr_usrreqs == NULL)
199 		return (EPROTONOSUPPORT);
200 	if (prp->pr_type != type)
201 		return (EPROTOTYPE);
202 	so = soalloc(prp, M_WAIT);
203 	so->so_type = type;
204 	if (suser(p) == 0)
205 		so->so_state = SS_PRIV;
206 	so->so_ruid = p->p_ucred->cr_ruid;
207 	so->so_euid = p->p_ucred->cr_uid;
208 	so->so_rgid = p->p_ucred->cr_rgid;
209 	so->so_egid = p->p_ucred->cr_gid;
210 	so->so_cpid = p->p_p->ps_pid;
211 	so->so_proto = prp;
212 	so->so_snd.sb_timeo_nsecs = INFSLP;
213 	so->so_rcv.sb_timeo_nsecs = INFSLP;
214 
215 	solock(so);
216 	error = pru_attach(so, proto, M_WAIT);
217 	if (error) {
218 		so->so_state |= SS_NOFDREF;
219 		/* sofree() calls sounlock(). */
220 		sofree(so, 0);
221 		return (error);
222 	}
223 	sounlock(so);
224 	*aso = so;
225 	return (0);
226 }
227 
228 int
229 sobind(struct socket *so, struct mbuf *nam, struct proc *p)
230 {
231 	soassertlocked(so);
232 	return pru_bind(so, nam, p);
233 }
234 
235 int
236 solisten(struct socket *so, int backlog)
237 {
238 	int somaxconn_local = atomic_load_int(&somaxconn);
239 	int sominconn_local = atomic_load_int(&sominconn);
240 	int error;
241 
242 	switch (so->so_type) {
243 	case SOCK_STREAM:
244 	case SOCK_SEQPACKET:
245 		break;
246 	default:
247 		return (EOPNOTSUPP);
248 	}
249 
250 	soassertlocked(so);
251 
252 	if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING|SS_ISDISCONNECTING))
253 		return (EINVAL);
254 #ifdef SOCKET_SPLICE
255 	if (isspliced(so) || issplicedback(so))
256 		return (EOPNOTSUPP);
257 #endif /* SOCKET_SPLICE */
258 	error = pru_listen(so);
259 	if (error)
260 		return (error);
261 	if (TAILQ_FIRST(&so->so_q) == NULL)
262 		so->so_options |= SO_ACCEPTCONN;
263 	if (backlog < 0 || backlog > somaxconn_local)
264 		backlog = somaxconn_local;
265 	if (backlog < sominconn_local)
266 		backlog = sominconn_local;
267 	so->so_qlimit = backlog;
268 	return (0);
269 }
270 
271 void
272 sorele(struct socket *so, int keep_lock)
273 {
274 	int need_lock = (((so->so_snd.sb_flags & SB_MTXLOCK) == 0) &&
275 	    keep_lock == 0);
276 
277 	if (keep_lock == 0)
278 		sounlock(so);
279 
280 	if (refcnt_rele(&so->so_refcnt) == 0)
281 		return;
282 
283 	sigio_free(&so->so_sigio);
284 	klist_free(&so->so_rcv.sb_klist);
285 	klist_free(&so->so_snd.sb_klist);
286 
287 	if (need_lock)
288 		solock(so);
289 	mtx_enter(&so->so_snd.sb_mtx);
290 	sbrelease(so, &so->so_snd);
291 	mtx_leave(&so->so_snd.sb_mtx);
292 	if (need_lock)
293 		sounlock(so);
294 
295 	if (so->so_proto->pr_flags & PR_RIGHTS &&
296 	    so->so_proto->pr_domain->dom_dispose)
297 		(*so->so_proto->pr_domain->dom_dispose)(so->so_rcv.sb_mb);
298 	m_purge(so->so_rcv.sb_mb);
299 
300 #ifdef SOCKET_SPLICE
301 	if (so->so_sp)
302 		pool_put(&sosplice_pool, so->so_sp);
303 #endif
304 	pool_put(&socket_pool, so);
305 }
306 
307 #define SOSP_FREEING_READ	1
308 #define SOSP_FREEING_WRITE	2
309 void
310 sofree(struct socket *so, int keep_lock)
311 {
312 	int persocket = solock_persocket(so);
313 
314 	soassertlocked(so);
315 
316 	if (so->so_pcb || (so->so_state & SS_NOFDREF) == 0) {
317 		if (!keep_lock)
318 			sounlock(so);
319 		return;
320 	}
321 	if (so->so_head) {
322 		struct socket *head = so->so_head;
323 
324 		/*
325 		 * We must not decommission a socket that's on the accept(2)
326 		 * queue.  If we do, then accept(2) may hang after select(2)
327 		 * indicated that the listening socket was ready.
328 		 */
329 		if (so->so_onq == &head->so_q) {
330 			if (!keep_lock)
331 				sounlock(so);
332 			return;
333 		}
334 
335 		if (persocket) {
336 			soref(head);
337 			sounlock(so);
338 			solock(head);
339 			solock(so);
340 
341 			if (so->so_onq != &head->so_q0) {
342 				sounlock(so);
343 				sorele(head, 0);
344 				return;
345 			}
346 		}
347 
348 		soqremque(so, 0);
349 
350 		if (persocket)
351 			sorele(head, 0);
352 	}
353 
354 	sorele(so, keep_lock);
355 }
356 
357 static inline uint64_t
358 solinger_nsec(struct socket *so)
359 {
360 	if (so->so_linger == 0)
361 		return INFSLP;
362 
363 	return SEC_TO_NSEC(so->so_linger);
364 }
365 
366 /*
367  * Close a socket on last file table reference removal.
368  * Initiate disconnect if connected.
369  * Free socket when disconnect complete.
370  */
371 int
372 soclose(struct socket *so, int flags)
373 {
374 	struct socket *so2;
375 	int error = 0;
376 
377 	solock(so);
378 	/* Revoke async IO early. There is a final revocation in sofree(). */
379 	sigio_free(&so->so_sigio);
380 	if (so->so_state & SS_ISCONNECTED) {
381 		if (so->so_pcb == NULL)
382 			goto discard;
383 		if ((so->so_state & SS_ISDISCONNECTING) == 0) {
384 			error = sodisconnect(so);
385 			if (error)
386 				goto drop;
387 		}
388 		if (so->so_options & SO_LINGER) {
389 			if ((so->so_state & SS_ISDISCONNECTING) &&
390 			    (flags & MSG_DONTWAIT))
391 				goto drop;
392 			while (so->so_state & SS_ISCONNECTED) {
393 				error = sosleep_nsec(so, &so->so_timeo,
394 				    PSOCK | PCATCH, "netcls",
395 				    solinger_nsec(so));
396 				if (error)
397 					break;
398 			}
399 		}
400 	}
401 drop:
402 	if (so->so_pcb) {
403 		int error2;
404 		error2 = pru_detach(so);
405 		if (error == 0)
406 			error = error2;
407 	}
408 	if (so->so_options & SO_ACCEPTCONN) {
409 		int persocket = solock_persocket(so);
410 
411 		while ((so2 = TAILQ_FIRST(&so->so_q0)) != NULL) {
412 			if (persocket)
413 				solock(so2);
414 			(void) soqremque(so2, 0);
415 			if (persocket)
416 				sounlock(so);
417 			soabort(so2);
418 			if (persocket)
419 				solock(so);
420 		}
421 		while ((so2 = TAILQ_FIRST(&so->so_q)) != NULL) {
422 			if (persocket)
423 				solock(so2);
424 			(void) soqremque(so2, 1);
425 			if (persocket)
426 				sounlock(so);
427 			soabort(so2);
428 			if (persocket)
429 				solock(so);
430 		}
431 	}
432 discard:
433 #ifdef SOCKET_SPLICE
434 	if (so->so_sp) {
435 		struct socket *soback;
436 
437 		sounlock(so);
438 		mtx_enter(&so->so_snd.sb_mtx);
439 		/*
440 		 * Concurrent sounsplice() locks `sb_mtx' mutexes on
441 		 * both `so_snd' and `so_rcv' before unsplice sockets.
442 		 */
443 		if ((soback = so->so_sp->ssp_soback) == NULL) {
444 			mtx_leave(&so->so_snd.sb_mtx);
445 			goto notsplicedback;
446 		}
447 		soref(soback);
448 		mtx_leave(&so->so_snd.sb_mtx);
449 
450 		/*
451 		 * `so' can be only unspliced, and never spliced again.
452 		 * Thus if issplicedback(so) check is positive, socket is
453 		 * still spliced and `ssp_soback' points to the same
454 		 * socket that `soback'.
455 		 */
456 		sblock(&soback->so_rcv, SBL_WAIT | SBL_NOINTR);
457 		if (issplicedback(so)) {
458 			int freeing = SOSP_FREEING_WRITE;
459 
460 			if (so->so_sp->ssp_soback == so)
461 				freeing |= SOSP_FREEING_READ;
462 			solock(soback);
463 			sounsplice(so->so_sp->ssp_soback, so, freeing);
464 			sounlock(soback);
465 		}
466 		sbunlock(&soback->so_rcv);
467 		solock(soback);
468 		sorele(soback, 0);
469 
470 notsplicedback:
471 		sblock(&so->so_rcv, SBL_WAIT | SBL_NOINTR);
472 		if (isspliced(so)) {
473 			int freeing = SOSP_FREEING_READ;
474 
475 			if (so == so->so_sp->ssp_socket)
476 				freeing |= SOSP_FREEING_WRITE;
477 			solock(so);
478 			sounsplice(so, so->so_sp->ssp_socket, freeing);
479 			sounlock(so);
480 		}
481 		sbunlock(&so->so_rcv);
482 
483 		timeout_del_barrier(&so->so_sp->ssp_idleto);
484 		task_del(sosplice_taskq, &so->so_sp->ssp_task);
485 		taskq_barrier(sosplice_taskq);
486 
487 		solock(so);
488 	}
489 #endif /* SOCKET_SPLICE */
490 
491 	if (so->so_state & SS_NOFDREF)
492 		panic("soclose NOFDREF: so %p, so_type %d", so, so->so_type);
493 	so->so_state |= SS_NOFDREF;
494 
495 	/* sofree() calls sounlock(). */
496 	sofree(so, 0);
497 	return (error);
498 }
499 
500 void
501 soabort(struct socket *so)
502 {
503 	soassertlocked(so);
504 	pru_abort(so);
505 }
506 
507 int
508 soaccept(struct socket *so, struct mbuf *nam)
509 {
510 	int error = 0;
511 
512 	soassertlocked(so);
513 
514 	if ((so->so_state & SS_NOFDREF) == 0)
515 		panic("soaccept !NOFDREF: so %p, so_type %d", so, so->so_type);
516 	so->so_state &= ~SS_NOFDREF;
517 	if ((so->so_state & SS_ISDISCONNECTED) == 0 ||
518 	    (so->so_proto->pr_flags & PR_ABRTACPTDIS) == 0)
519 		error = pru_accept(so, nam);
520 	else
521 		error = ECONNABORTED;
522 	return (error);
523 }
524 
525 int
526 soconnect(struct socket *so, struct mbuf *nam)
527 {
528 	int error;
529 
530 	soassertlocked(so);
531 
532 	if (so->so_options & SO_ACCEPTCONN)
533 		return (EOPNOTSUPP);
534 	/*
535 	 * If protocol is connection-based, can only connect once.
536 	 * Otherwise, if connected, try to disconnect first.
537 	 * This allows user to disconnect by connecting to, e.g.,
538 	 * a null address.
539 	 */
540 	if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
541 	    ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
542 	    (error = sodisconnect(so))))
543 		error = EISCONN;
544 	else
545 		error = pru_connect(so, nam);
546 	return (error);
547 }
548 
549 int
550 soconnect2(struct socket *so1, struct socket *so2)
551 {
552 	int persocket, error;
553 
554 	if ((persocket = solock_persocket(so1)))
555 		solock_pair(so1, so2);
556 	else
557 		solock(so1);
558 
559 	error = pru_connect2(so1, so2);
560 
561 	if (persocket)
562 		sounlock(so2);
563 	sounlock(so1);
564 	return (error);
565 }
566 
567 int
568 sodisconnect(struct socket *so)
569 {
570 	int error;
571 
572 	soassertlocked(so);
573 
574 	if ((so->so_state & SS_ISCONNECTED) == 0)
575 		return (ENOTCONN);
576 	if (so->so_state & SS_ISDISCONNECTING)
577 		return (EALREADY);
578 	error = pru_disconnect(so);
579 	return (error);
580 }
581 
582 int m_getuio(struct mbuf **, int, long, struct uio *);
583 
584 #define	SBLOCKWAIT(f)	(((f) & MSG_DONTWAIT) ? 0 : SBL_WAIT)
585 /*
586  * Send on a socket.
587  * If send must go all at once and message is larger than
588  * send buffering, then hard error.
589  * Lock against other senders.
590  * If must go all at once and not enough room now, then
591  * inform user that this would block and do nothing.
592  * Otherwise, if nonblocking, send as much as possible.
593  * The data to be sent is described by "uio" if nonzero,
594  * otherwise by the mbuf chain "top" (which must be null
595  * if uio is not).  Data provided in mbuf chain must be small
596  * enough to send all at once.
597  *
598  * Returns nonzero on error, timeout or signal; callers
599  * must check for short counts if EINTR/ERESTART are returned.
600  * Data and control buffers are freed on return.
601  */
602 int
603 sosend(struct socket *so, struct mbuf *addr, struct uio *uio, struct mbuf *top,
604     struct mbuf *control, int flags)
605 {
606 	long space, clen = 0;
607 	size_t resid;
608 	int error;
609 	int atomic = sosendallatonce(so) || top;
610 	int dosolock = ((so->so_snd.sb_flags & SB_MTXLOCK) == 0);
611 
612 	if (uio)
613 		resid = uio->uio_resid;
614 	else
615 		resid = top->m_pkthdr.len;
616 	/* MSG_EOR on a SOCK_STREAM socket is invalid. */
617 	if (so->so_type == SOCK_STREAM && (flags & MSG_EOR)) {
618 		m_freem(top);
619 		m_freem(control);
620 		return (EINVAL);
621 	}
622 	if (uio && uio->uio_procp)
623 		uio->uio_procp->p_ru.ru_msgsnd++;
624 	if (control) {
625 		/*
626 		 * In theory clen should be unsigned (since control->m_len is).
627 		 * However, space must be signed, as it might be less than 0
628 		 * if we over-committed, and we must use a signed comparison
629 		 * of space and clen.
630 		 */
631 		clen = control->m_len;
632 		/* reserve extra space for AF_UNIX's internalize */
633 		if (so->so_proto->pr_domain->dom_family == AF_UNIX &&
634 		    clen >= CMSG_ALIGN(sizeof(struct cmsghdr)) &&
635 		    mtod(control, struct cmsghdr *)->cmsg_type == SCM_RIGHTS)
636 			clen = CMSG_SPACE(
637 			    (clen - CMSG_ALIGN(sizeof(struct cmsghdr))) *
638 			    (sizeof(struct fdpass) / sizeof(int)));
639 	}
640 
641 #define	snderr(errno)	{ error = errno; goto release; }
642 
643 restart:
644 	if ((error = sblock(&so->so_snd, SBLOCKWAIT(flags))) != 0)
645 		goto out;
646 	if (dosolock)
647 		solock_shared(so);
648 	sb_mtx_lock(&so->so_snd);
649 	so->so_snd.sb_state |= SS_ISSENDING;
650 	do {
651 		if (so->so_snd.sb_state & SS_CANTSENDMORE)
652 			snderr(EPIPE);
653 		if ((error = READ_ONCE(so->so_error))) {
654 			so->so_error = 0;
655 			snderr(error);
656 		}
657 		if ((so->so_state & SS_ISCONNECTED) == 0) {
658 			if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
659 				if (!(resid == 0 && clen != 0))
660 					snderr(ENOTCONN);
661 			} else if (addr == NULL)
662 				snderr(EDESTADDRREQ);
663 		}
664 		space = sbspace_locked(so, &so->so_snd);
665 		if (flags & MSG_OOB)
666 			space += 1024;
667 		if (so->so_proto->pr_domain->dom_family == AF_UNIX) {
668 			if (atomic && resid > so->so_snd.sb_hiwat)
669 				snderr(EMSGSIZE);
670 		} else {
671 			if (clen > so->so_snd.sb_hiwat ||
672 			    (atomic && resid > so->so_snd.sb_hiwat - clen))
673 				snderr(EMSGSIZE);
674 		}
675 		if (space < clen ||
676 		    (space - clen < resid &&
677 		    (atomic || space < so->so_snd.sb_lowat))) {
678 			if (flags & MSG_DONTWAIT)
679 				snderr(EWOULDBLOCK);
680 			sbunlock(&so->so_snd);
681 			error = sbwait(so, &so->so_snd);
682 			so->so_snd.sb_state &= ~SS_ISSENDING;
683 			sb_mtx_unlock(&so->so_snd);
684 			if (dosolock)
685 				sounlock_shared(so);
686 			if (error)
687 				goto out;
688 			goto restart;
689 		}
690 		space -= clen;
691 		do {
692 			if (uio == NULL) {
693 				/*
694 				 * Data is prepackaged in "top".
695 				 */
696 				resid = 0;
697 				if (flags & MSG_EOR)
698 					top->m_flags |= M_EOR;
699 			} else {
700 				sb_mtx_unlock(&so->so_snd);
701 				if (dosolock)
702 					sounlock_shared(so);
703 				error = m_getuio(&top, atomic, space, uio);
704 				if (dosolock)
705 					solock_shared(so);
706 				sb_mtx_lock(&so->so_snd);
707 				if (error)
708 					goto release;
709 				space -= top->m_pkthdr.len;
710 				resid = uio->uio_resid;
711 				if (flags & MSG_EOR)
712 					top->m_flags |= M_EOR;
713 			}
714 			if (resid == 0)
715 				so->so_snd.sb_state &= ~SS_ISSENDING;
716 			if (top && so->so_options & SO_ZEROIZE)
717 				top->m_flags |= M_ZEROIZE;
718 			sb_mtx_unlock(&so->so_snd);
719 			if (!dosolock)
720 				solock_shared(so);
721 			if (flags & MSG_OOB)
722 				error = pru_sendoob(so, top, addr, control);
723 			else
724 				error = pru_send(so, top, addr, control);
725 			if (!dosolock)
726 				sounlock_shared(so);
727 			sb_mtx_lock(&so->so_snd);
728 			clen = 0;
729 			control = NULL;
730 			top = NULL;
731 			if (error)
732 				goto release;
733 		} while (resid && space > 0);
734 	} while (resid);
735 
736 release:
737 	so->so_snd.sb_state &= ~SS_ISSENDING;
738 	sb_mtx_unlock(&so->so_snd);
739 	if (dosolock)
740 		sounlock_shared(so);
741 	sbunlock(&so->so_snd);
742 out:
743 	m_freem(top);
744 	m_freem(control);
745 	return (error);
746 }
747 
748 int
749 m_getuio(struct mbuf **mp, int atomic, long space, struct uio *uio)
750 {
751 	struct mbuf *m, *top = NULL;
752 	struct mbuf **nextp = &top;
753 	u_long len, mlen;
754 	size_t resid = uio->uio_resid;
755 	int error;
756 
757 	do {
758 		if (top == NULL) {
759 			MGETHDR(m, M_WAIT, MT_DATA);
760 			mlen = MHLEN;
761 		} else {
762 			MGET(m, M_WAIT, MT_DATA);
763 			mlen = MLEN;
764 		}
765 		/* chain mbuf together */
766 		*nextp = m;
767 		nextp = &m->m_next;
768 
769 		resid = ulmin(resid, space);
770 		if (resid >= MINCLSIZE) {
771 			MCLGETL(m, M_NOWAIT, ulmin(resid, MAXMCLBYTES));
772 			if ((m->m_flags & M_EXT) == 0)
773 				MCLGETL(m, M_NOWAIT, MCLBYTES);
774 			if ((m->m_flags & M_EXT) == 0)
775 				goto nopages;
776 			mlen = m->m_ext.ext_size;
777 			len = ulmin(mlen, resid);
778 			/*
779 			 * For datagram protocols, leave room
780 			 * for protocol headers in first mbuf.
781 			 */
782 			if (atomic && m == top && len < mlen - max_hdr)
783 				m->m_data += max_hdr;
784 		} else {
785 nopages:
786 			len = ulmin(mlen, resid);
787 			/*
788 			 * For datagram protocols, leave room
789 			 * for protocol headers in first mbuf.
790 			 */
791 			if (atomic && m == top && len < mlen - max_hdr)
792 				m_align(m, len);
793 		}
794 
795 		error = uiomove(mtod(m, caddr_t), len, uio);
796 		if (error) {
797 			m_freem(top);
798 			return (error);
799 		}
800 
801 		/* adjust counters */
802 		resid = uio->uio_resid;
803 		space -= len;
804 		m->m_len = len;
805 		top->m_pkthdr.len += len;
806 
807 		/* Is there more space and more data? */
808 	} while (space > 0 && resid > 0);
809 
810 	*mp = top;
811 	return 0;
812 }
813 
814 /*
815  * Following replacement or removal of the first mbuf on the first
816  * mbuf chain of a socket buffer, push necessary state changes back
817  * into the socket buffer so that other consumers see the values
818  * consistently.  'nextrecord' is the callers locally stored value of
819  * the original value of sb->sb_mb->m_nextpkt which must be restored
820  * when the lead mbuf changes.  NOTE: 'nextrecord' may be NULL.
821  */
822 void
823 sbsync(struct sockbuf *sb, struct mbuf *nextrecord)
824 {
825 
826 	/*
827 	 * First, update for the new value of nextrecord.  If necessary,
828 	 * make it the first record.
829 	 */
830 	if (sb->sb_mb != NULL)
831 		sb->sb_mb->m_nextpkt = nextrecord;
832 	else
833 		sb->sb_mb = nextrecord;
834 
835 	/*
836 	 * Now update any dependent socket buffer fields to reflect
837 	 * the new state.  This is an inline of SB_EMPTY_FIXUP, with
838 	 * the addition of a second clause that takes care of the
839 	 * case where sb_mb has been updated, but remains the last
840 	 * record.
841 	 */
842 	if (sb->sb_mb == NULL) {
843 		sb->sb_mbtail = NULL;
844 		sb->sb_lastrecord = NULL;
845 	} else if (sb->sb_mb->m_nextpkt == NULL)
846 		sb->sb_lastrecord = sb->sb_mb;
847 }
848 
849 /*
850  * Implement receive operations on a socket.
851  * We depend on the way that records are added to the sockbuf
852  * by sbappend*.  In particular, each record (mbufs linked through m_next)
853  * must begin with an address if the protocol so specifies,
854  * followed by an optional mbuf or mbufs containing ancillary data,
855  * and then zero or more mbufs of data.
856  * In order to avoid blocking network for the entire time here, we release
857  * the solock() while doing the actual copy to user space.
858  * Although the sockbuf is locked, new data may still be appended,
859  * and thus we must maintain consistency of the sockbuf during that time.
860  *
861  * The caller may receive the data as a single mbuf chain by supplying
862  * an mbuf **mp0 for use in returning the chain.  The uio is then used
863  * only for the count in uio_resid.
864  */
865 int
866 soreceive(struct socket *so, struct mbuf **paddr, struct uio *uio,
867     struct mbuf **mp0, struct mbuf **controlp, int *flagsp,
868     socklen_t controllen)
869 {
870 	struct mbuf *m, **mp;
871 	struct mbuf *cm;
872 	u_long len, offset, moff;
873 	int flags, error, error2, type, uio_error = 0;
874 	const struct protosw *pr = so->so_proto;
875 	struct mbuf *nextrecord;
876 	size_t resid, orig_resid = uio->uio_resid;
877 	int dosolock = ((so->so_rcv.sb_flags & SB_MTXLOCK) == 0);
878 
879 	mp = mp0;
880 	if (paddr)
881 		*paddr = NULL;
882 	if (controlp)
883 		*controlp = NULL;
884 	if (flagsp)
885 		flags = *flagsp &~ MSG_EOR;
886 	else
887 		flags = 0;
888 	if (flags & MSG_OOB) {
889 		m = m_get(M_WAIT, MT_DATA);
890 		solock_shared(so);
891 		error = pru_rcvoob(so, m, flags & MSG_PEEK);
892 		sounlock_shared(so);
893 		if (error)
894 			goto bad;
895 		do {
896 			error = uiomove(mtod(m, caddr_t),
897 			    ulmin(uio->uio_resid, m->m_len), uio);
898 			m = m_free(m);
899 		} while (uio->uio_resid && error == 0 && m);
900 bad:
901 		m_freem(m);
902 		return (error);
903 	}
904 	if (mp)
905 		*mp = NULL;
906 
907 restart:
908 	if ((error = sblock(&so->so_rcv, SBLOCKWAIT(flags))) != 0)
909 		return (error);
910 	if (dosolock)
911 		solock_shared(so);
912 	sb_mtx_lock(&so->so_rcv);
913 
914 	m = so->so_rcv.sb_mb;
915 #ifdef SOCKET_SPLICE
916 	if (isspliced(so))
917 		m = NULL;
918 #endif /* SOCKET_SPLICE */
919 	/*
920 	 * If we have less data than requested, block awaiting more
921 	 * (subject to any timeout) if:
922 	 *   1. the current count is less than the low water mark,
923 	 *   2. MSG_WAITALL is set, and it is possible to do the entire
924 	 *	receive operation at once if we block (resid <= hiwat), or
925 	 *   3. MSG_DONTWAIT is not set.
926 	 * If MSG_WAITALL is set but resid is larger than the receive buffer,
927 	 * we have to do the receive in sections, and thus risk returning
928 	 * a short count if a timeout or signal occurs after we start.
929 	 */
930 	if (m == NULL || (((flags & MSG_DONTWAIT) == 0 &&
931 	    so->so_rcv.sb_cc < uio->uio_resid) &&
932 	    (so->so_rcv.sb_cc < so->so_rcv.sb_lowat ||
933 	    ((flags & MSG_WAITALL) && uio->uio_resid <= so->so_rcv.sb_hiwat)) &&
934 	    m->m_nextpkt == NULL && (pr->pr_flags & PR_ATOMIC) == 0)) {
935 #ifdef DIAGNOSTIC
936 		if (m == NULL && so->so_rcv.sb_cc)
937 #ifdef SOCKET_SPLICE
938 		    if (!isspliced(so))
939 #endif /* SOCKET_SPLICE */
940 			panic("receive 1: so %p, so_type %d, sb_cc %lu",
941 			    so, so->so_type, so->so_rcv.sb_cc);
942 #endif
943 		if ((error2 = READ_ONCE(so->so_error))) {
944 			if (m)
945 				goto dontblock;
946 			error = error2;
947 			if ((flags & MSG_PEEK) == 0)
948 				so->so_error = 0;
949 			goto release;
950 		}
951 		if (so->so_rcv.sb_state & SS_CANTRCVMORE) {
952 			if (m)
953 				goto dontblock;
954 			else if (so->so_rcv.sb_cc == 0)
955 				goto release;
956 		}
957 		for (; m; m = m->m_next)
958 			if (m->m_type == MT_OOBDATA  || (m->m_flags & M_EOR)) {
959 				m = so->so_rcv.sb_mb;
960 				goto dontblock;
961 			}
962 		if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
963 		    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
964 			error = ENOTCONN;
965 			goto release;
966 		}
967 		if (uio->uio_resid == 0 && controlp == NULL)
968 			goto release;
969 		if (flags & MSG_DONTWAIT) {
970 			error = EWOULDBLOCK;
971 			goto release;
972 		}
973 		SBLASTRECORDCHK(&so->so_rcv, "soreceive sbwait 1");
974 		SBLASTMBUFCHK(&so->so_rcv, "soreceive sbwait 1");
975 
976 		sbunlock(&so->so_rcv);
977 		error = sbwait(so, &so->so_rcv);
978 		sb_mtx_unlock(&so->so_rcv);
979 		if (dosolock)
980 			sounlock_shared(so);
981 		if (error)
982 			return (error);
983 		goto restart;
984 	}
985 dontblock:
986 	/*
987 	 * On entry here, m points to the first record of the socket buffer.
988 	 * From this point onward, we maintain 'nextrecord' as a cache of the
989 	 * pointer to the next record in the socket buffer.  We must keep the
990 	 * various socket buffer pointers and local stack versions of the
991 	 * pointers in sync, pushing out modifications before operations that
992 	 * may sleep, and re-reading them afterwards.
993 	 *
994 	 * Otherwise, we will race with the network stack appending new data
995 	 * or records onto the socket buffer by using inconsistent/stale
996 	 * versions of the field, possibly resulting in socket buffer
997 	 * corruption.
998 	 */
999 	if (uio->uio_procp)
1000 		uio->uio_procp->p_ru.ru_msgrcv++;
1001 	KASSERT(m == so->so_rcv.sb_mb);
1002 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 1");
1003 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 1");
1004 	nextrecord = m->m_nextpkt;
1005 	if (pr->pr_flags & PR_ADDR) {
1006 #ifdef DIAGNOSTIC
1007 		if (m->m_type != MT_SONAME)
1008 			panic("receive 1a: so %p, so_type %d, m %p, m_type %d",
1009 			    so, so->so_type, m, m->m_type);
1010 #endif
1011 		orig_resid = 0;
1012 		if (flags & MSG_PEEK) {
1013 			if (paddr)
1014 				*paddr = m_copym(m, 0, m->m_len, M_NOWAIT);
1015 			m = m->m_next;
1016 		} else {
1017 			sbfree(so, &so->so_rcv, m);
1018 			if (paddr) {
1019 				*paddr = m;
1020 				so->so_rcv.sb_mb = m->m_next;
1021 				m->m_next = NULL;
1022 				m = so->so_rcv.sb_mb;
1023 			} else {
1024 				so->so_rcv.sb_mb = m_free(m);
1025 				m = so->so_rcv.sb_mb;
1026 			}
1027 			sbsync(&so->so_rcv, nextrecord);
1028 		}
1029 	}
1030 	while (m && m->m_type == MT_CONTROL && error == 0) {
1031 		int skip = 0;
1032 		if (flags & MSG_PEEK) {
1033 			if (mtod(m, struct cmsghdr *)->cmsg_type ==
1034 			    SCM_RIGHTS) {
1035 				/* don't leak internalized SCM_RIGHTS msgs */
1036 				skip = 1;
1037 			} else if (controlp)
1038 				*controlp = m_copym(m, 0, m->m_len, M_NOWAIT);
1039 			m = m->m_next;
1040 		} else {
1041 			sbfree(so, &so->so_rcv, m);
1042 			so->so_rcv.sb_mb = m->m_next;
1043 			m->m_nextpkt = m->m_next = NULL;
1044 			cm = m;
1045 			m = so->so_rcv.sb_mb;
1046 			sbsync(&so->so_rcv, nextrecord);
1047 			if (controlp) {
1048 				if (pr->pr_domain->dom_externalize) {
1049 					sb_mtx_unlock(&so->so_rcv);
1050 					if (dosolock)
1051 						sounlock_shared(so);
1052 					error =
1053 					    (*pr->pr_domain->dom_externalize)
1054 					    (cm, controllen, flags);
1055 					if (dosolock)
1056 						solock_shared(so);
1057 					sb_mtx_lock(&so->so_rcv);
1058 				}
1059 				*controlp = cm;
1060 			} else {
1061 				/*
1062 				 * Dispose of any SCM_RIGHTS message that went
1063 				 * through the read path rather than recv.
1064 				 */
1065 				if (pr->pr_domain->dom_dispose) {
1066 					sb_mtx_unlock(&so->so_rcv);
1067 					pr->pr_domain->dom_dispose(cm);
1068 					sb_mtx_lock(&so->so_rcv);
1069 				}
1070 				m_free(cm);
1071 			}
1072 		}
1073 		if (m != NULL)
1074 			nextrecord = so->so_rcv.sb_mb->m_nextpkt;
1075 		else
1076 			nextrecord = so->so_rcv.sb_mb;
1077 		if (controlp && !skip)
1078 			controlp = &(*controlp)->m_next;
1079 		orig_resid = 0;
1080 	}
1081 
1082 	/* If m is non-NULL, we have some data to read. */
1083 	if (m) {
1084 		type = m->m_type;
1085 		if (type == MT_OOBDATA)
1086 			flags |= MSG_OOB;
1087 		if (m->m_flags & M_BCAST)
1088 			flags |= MSG_BCAST;
1089 		if (m->m_flags & M_MCAST)
1090 			flags |= MSG_MCAST;
1091 	}
1092 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 2");
1093 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 2");
1094 
1095 	moff = 0;
1096 	offset = 0;
1097 	while (m && uio->uio_resid > 0 && error == 0) {
1098 		if (m->m_type == MT_OOBDATA) {
1099 			if (type != MT_OOBDATA)
1100 				break;
1101 		} else if (type == MT_OOBDATA) {
1102 			break;
1103 		} else if (m->m_type == MT_CONTROL) {
1104 			/*
1105 			 * If there is more than one control message in the
1106 			 * stream, we do a short read.  Next can be received
1107 			 * or disposed by another system call.
1108 			 */
1109 			break;
1110 #ifdef DIAGNOSTIC
1111 		} else if (m->m_type != MT_DATA && m->m_type != MT_HEADER) {
1112 			panic("receive 3: so %p, so_type %d, m %p, m_type %d",
1113 			    so, so->so_type, m, m->m_type);
1114 #endif
1115 		}
1116 		so->so_rcv.sb_state &= ~SS_RCVATMARK;
1117 		len = uio->uio_resid;
1118 		if (so->so_oobmark && len > so->so_oobmark - offset)
1119 			len = so->so_oobmark - offset;
1120 		if (len > m->m_len - moff)
1121 			len = m->m_len - moff;
1122 		/*
1123 		 * If mp is set, just pass back the mbufs.
1124 		 * Otherwise copy them out via the uio, then free.
1125 		 * Sockbuf must be consistent here (points to current mbuf,
1126 		 * it points to next record) when we drop priority;
1127 		 * we must note any additions to the sockbuf when we
1128 		 * block interrupts again.
1129 		 */
1130 		if (mp == NULL && uio_error == 0) {
1131 			SBLASTRECORDCHK(&so->so_rcv, "soreceive uiomove");
1132 			SBLASTMBUFCHK(&so->so_rcv, "soreceive uiomove");
1133 			resid = uio->uio_resid;
1134 			sb_mtx_unlock(&so->so_rcv);
1135 			if (dosolock)
1136 				sounlock_shared(so);
1137 			uio_error = uiomove(mtod(m, caddr_t) + moff, len, uio);
1138 			if (dosolock)
1139 				solock_shared(so);
1140 			sb_mtx_lock(&so->so_rcv);
1141 			if (uio_error)
1142 				uio->uio_resid = resid - len;
1143 		} else
1144 			uio->uio_resid -= len;
1145 		if (len == m->m_len - moff) {
1146 			if (m->m_flags & M_EOR)
1147 				flags |= MSG_EOR;
1148 			if (flags & MSG_PEEK) {
1149 				m = m->m_next;
1150 				moff = 0;
1151 				orig_resid = 0;
1152 			} else {
1153 				nextrecord = m->m_nextpkt;
1154 				sbfree(so, &so->so_rcv, m);
1155 				if (mp) {
1156 					*mp = m;
1157 					mp = &m->m_next;
1158 					so->so_rcv.sb_mb = m = m->m_next;
1159 					*mp = NULL;
1160 				} else {
1161 					so->so_rcv.sb_mb = m_free(m);
1162 					m = so->so_rcv.sb_mb;
1163 				}
1164 				/*
1165 				 * If m != NULL, we also know that
1166 				 * so->so_rcv.sb_mb != NULL.
1167 				 */
1168 				KASSERT(so->so_rcv.sb_mb == m);
1169 				if (m) {
1170 					m->m_nextpkt = nextrecord;
1171 					if (nextrecord == NULL)
1172 						so->so_rcv.sb_lastrecord = m;
1173 				} else {
1174 					so->so_rcv.sb_mb = nextrecord;
1175 					SB_EMPTY_FIXUP(&so->so_rcv);
1176 				}
1177 				SBLASTRECORDCHK(&so->so_rcv, "soreceive 3");
1178 				SBLASTMBUFCHK(&so->so_rcv, "soreceive 3");
1179 			}
1180 		} else {
1181 			if (flags & MSG_PEEK) {
1182 				moff += len;
1183 				orig_resid = 0;
1184 			} else {
1185 				if (mp)
1186 					*mp = m_copym(m, 0, len, M_WAIT);
1187 				m->m_data += len;
1188 				m->m_len -= len;
1189 				so->so_rcv.sb_cc -= len;
1190 				so->so_rcv.sb_datacc -= len;
1191 			}
1192 		}
1193 		if (so->so_oobmark) {
1194 			if ((flags & MSG_PEEK) == 0) {
1195 				so->so_oobmark -= len;
1196 				if (so->so_oobmark == 0) {
1197 					so->so_rcv.sb_state |= SS_RCVATMARK;
1198 					break;
1199 				}
1200 			} else {
1201 				offset += len;
1202 				if (offset == so->so_oobmark)
1203 					break;
1204 			}
1205 		}
1206 		if (flags & MSG_EOR)
1207 			break;
1208 		/*
1209 		 * If the MSG_WAITALL flag is set (for non-atomic socket),
1210 		 * we must not quit until "uio->uio_resid == 0" or an error
1211 		 * termination.  If a signal/timeout occurs, return
1212 		 * with a short count but without error.
1213 		 * Keep sockbuf locked against other readers.
1214 		 */
1215 		while (flags & MSG_WAITALL && m == NULL && uio->uio_resid > 0 &&
1216 		    !sosendallatonce(so) && !nextrecord) {
1217 			if (so->so_rcv.sb_state & SS_CANTRCVMORE ||
1218 			    so->so_error)
1219 				break;
1220 			SBLASTRECORDCHK(&so->so_rcv, "soreceive sbwait 2");
1221 			SBLASTMBUFCHK(&so->so_rcv, "soreceive sbwait 2");
1222 			if (sbwait(so, &so->so_rcv)) {
1223 				sb_mtx_unlock(&so->so_rcv);
1224 				if (dosolock)
1225 					sounlock_shared(so);
1226 				sbunlock(&so->so_rcv);
1227 				return (0);
1228 			}
1229 			if ((m = so->so_rcv.sb_mb) != NULL)
1230 				nextrecord = m->m_nextpkt;
1231 		}
1232 	}
1233 
1234 	if (m && pr->pr_flags & PR_ATOMIC) {
1235 		flags |= MSG_TRUNC;
1236 		if ((flags & MSG_PEEK) == 0)
1237 			(void) sbdroprecord(so, &so->so_rcv);
1238 	}
1239 	if ((flags & MSG_PEEK) == 0) {
1240 		if (m == NULL) {
1241 			/*
1242 			 * First part is an inline SB_EMPTY_FIXUP().  Second
1243 			 * part makes sure sb_lastrecord is up-to-date if
1244 			 * there is still data in the socket buffer.
1245 			 */
1246 			so->so_rcv.sb_mb = nextrecord;
1247 			if (so->so_rcv.sb_mb == NULL) {
1248 				so->so_rcv.sb_mbtail = NULL;
1249 				so->so_rcv.sb_lastrecord = NULL;
1250 			} else if (nextrecord->m_nextpkt == NULL)
1251 				so->so_rcv.sb_lastrecord = nextrecord;
1252 		}
1253 		SBLASTRECORDCHK(&so->so_rcv, "soreceive 4");
1254 		SBLASTMBUFCHK(&so->so_rcv, "soreceive 4");
1255 		if (pr->pr_flags & PR_WANTRCVD) {
1256 			sb_mtx_unlock(&so->so_rcv);
1257 			if (!dosolock)
1258 				solock_shared(so);
1259 			pru_rcvd(so);
1260 			if (!dosolock)
1261 				sounlock_shared(so);
1262 			sb_mtx_lock(&so->so_rcv);
1263 		}
1264 	}
1265 	if (orig_resid == uio->uio_resid && orig_resid &&
1266 	    (flags & MSG_EOR) == 0 &&
1267 	    (so->so_rcv.sb_state & SS_CANTRCVMORE) == 0) {
1268 		sb_mtx_unlock(&so->so_rcv);
1269 		sbunlock(&so->so_rcv);
1270 		goto restart;
1271 	}
1272 
1273 	if (uio_error)
1274 		error = uio_error;
1275 
1276 	if (flagsp)
1277 		*flagsp |= flags;
1278 release:
1279 	sb_mtx_unlock(&so->so_rcv);
1280 	if (dosolock)
1281 		sounlock_shared(so);
1282 	sbunlock(&so->so_rcv);
1283 	return (error);
1284 }
1285 
1286 int
1287 soshutdown(struct socket *so, int how)
1288 {
1289 	int error = 0;
1290 
1291 	switch (how) {
1292 	case SHUT_RD:
1293 		sorflush(so);
1294 		break;
1295 	case SHUT_RDWR:
1296 		sorflush(so);
1297 		/* FALLTHROUGH */
1298 	case SHUT_WR:
1299 		solock(so);
1300 		error = pru_shutdown(so);
1301 		sounlock(so);
1302 		break;
1303 	default:
1304 		error = EINVAL;
1305 		break;
1306 	}
1307 
1308 	return (error);
1309 }
1310 
1311 void
1312 sorflush(struct socket *so)
1313 {
1314 	struct sockbuf *sb = &so->so_rcv;
1315 	struct mbuf *m;
1316 	const struct protosw *pr = so->so_proto;
1317 	int error;
1318 
1319 	error = sblock(sb, SBL_WAIT | SBL_NOINTR);
1320 	/* with SBL_WAIT and SLB_NOINTR sblock() must not fail */
1321 	KASSERT(error == 0);
1322 
1323 	solock_shared(so);
1324 	socantrcvmore(so);
1325 	mtx_enter(&sb->sb_mtx);
1326 	m = sb->sb_mb;
1327 	memset(&sb->sb_startzero, 0,
1328 	     (caddr_t)&sb->sb_endzero - (caddr_t)&sb->sb_startzero);
1329 	sb->sb_timeo_nsecs = INFSLP;
1330 	mtx_leave(&sb->sb_mtx);
1331 	sounlock_shared(so);
1332 	sbunlock(sb);
1333 
1334 	if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose)
1335 		(*pr->pr_domain->dom_dispose)(m);
1336 	m_purge(m);
1337 }
1338 
1339 #ifdef SOCKET_SPLICE
1340 
1341 #define so_splicelen	so_sp->ssp_len
1342 #define so_splicemax	so_sp->ssp_max
1343 #define so_idletv	so_sp->ssp_idletv
1344 #define so_idleto	so_sp->ssp_idleto
1345 #define so_splicetask	so_sp->ssp_task
1346 
1347 int
1348 sosplice(struct socket *so, int fd, off_t max, struct timeval *tv)
1349 {
1350 	struct file	*fp;
1351 	struct socket	*sosp;
1352 	struct taskq	*tq;
1353 	int		 error = 0;
1354 
1355 	if ((so->so_proto->pr_flags & PR_SPLICE) == 0)
1356 		return (EPROTONOSUPPORT);
1357 	if (max && max < 0)
1358 		return (EINVAL);
1359 	if (tv && (tv->tv_sec < 0 || !timerisvalid(tv)))
1360 		return (EINVAL);
1361 
1362 	/* If no fd is given, unsplice by removing existing link. */
1363 	if (fd < 0) {
1364 		if ((error = sblock(&so->so_rcv, SBL_WAIT)) != 0)
1365 			return (error);
1366 		solock(so);
1367 		if (so->so_options & SO_ACCEPTCONN) {
1368 			error = EOPNOTSUPP;
1369 			goto out;
1370 		}
1371 		if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
1372 		    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
1373 			error = ENOTCONN;
1374 			goto out;
1375 		}
1376 
1377 		if (so->so_sp && so->so_sp->ssp_socket)
1378 			sounsplice(so, so->so_sp->ssp_socket, 0);
1379  out:
1380 		sounlock(so);
1381 		sbunlock(&so->so_rcv);
1382 		return (error);
1383 	}
1384 
1385 	if (sosplice_taskq == NULL) {
1386 		rw_enter_write(&sosplice_lock);
1387 		if (sosplice_taskq == NULL) {
1388 			tq = taskq_create("sosplice", 1, IPL_SOFTNET,
1389 			    TASKQ_MPSAFE);
1390 			if (tq == NULL) {
1391 				rw_exit_write(&sosplice_lock);
1392 				return (ENOMEM);
1393 			}
1394 			/* Ensure the taskq is fully visible to other CPUs. */
1395 			membar_producer();
1396 			sosplice_taskq = tq;
1397 		}
1398 		rw_exit_write(&sosplice_lock);
1399 	} else {
1400 		/* Ensure the taskq is fully visible on this CPU. */
1401 		membar_consumer();
1402 	}
1403 
1404 	/* Find sosp, the drain socket where data will be spliced into. */
1405 	if ((error = getsock(curproc, fd, &fp)) != 0)
1406 		return (error);
1407 	sosp = fp->f_data;
1408 
1409 	if (sosp->so_proto->pr_usrreqs->pru_send !=
1410 	    so->so_proto->pr_usrreqs->pru_send) {
1411 		error = EPROTONOSUPPORT;
1412 		goto frele;
1413 	}
1414 
1415 	if ((error = sblock(&so->so_rcv, SBL_WAIT)) != 0)
1416 		goto frele;
1417 	if ((error = sblock(&sosp->so_snd, SBL_WAIT)) != 0) {
1418 		sbunlock(&so->so_rcv);
1419 		goto frele;
1420 	}
1421 	solock(so);
1422 
1423 	if ((so->so_options & SO_ACCEPTCONN) ||
1424 	    (sosp->so_options & SO_ACCEPTCONN)) {
1425 		error = EOPNOTSUPP;
1426 		goto release;
1427 	}
1428 	if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
1429 	    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
1430 		error = ENOTCONN;
1431 		goto release;
1432 	}
1433 	if ((sosp->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0) {
1434 		error = ENOTCONN;
1435 		goto release;
1436 	}
1437 	if (so->so_sp == NULL)
1438 		so->so_sp = pool_get(&sosplice_pool, PR_WAITOK | PR_ZERO);
1439 	if (sosp->so_sp == NULL)
1440 		sosp->so_sp = pool_get(&sosplice_pool, PR_WAITOK | PR_ZERO);
1441 	if (so->so_sp->ssp_socket || sosp->so_sp->ssp_soback) {
1442 		error = EBUSY;
1443 		goto release;
1444 	}
1445 
1446 	so->so_splicelen = 0;
1447 	so->so_splicemax = max;
1448 	if (tv)
1449 		so->so_idletv = *tv;
1450 	else
1451 		timerclear(&so->so_idletv);
1452 	timeout_set_flags(&so->so_idleto, soidle, so,
1453 	    KCLOCK_NONE, TIMEOUT_PROC | TIMEOUT_MPSAFE);
1454 	task_set(&so->so_splicetask, sotask, so);
1455 
1456 	/*
1457 	 * To prevent sorwakeup() calling somove() before this somove()
1458 	 * has finished, the socket buffers are not marked as spliced yet.
1459 	 */
1460 
1461 	/* Splice so and sosp together. */
1462 	mtx_enter(&so->so_rcv.sb_mtx);
1463 	mtx_enter(&sosp->so_snd.sb_mtx);
1464 	so->so_sp->ssp_socket = sosp;
1465 	sosp->so_sp->ssp_soback = so;
1466 	mtx_leave(&sosp->so_snd.sb_mtx);
1467 	mtx_leave(&so->so_rcv.sb_mtx);
1468 
1469 	if ((so->so_proto->pr_flags & PR_WANTRCVD) == 0)
1470 		sounlock(so);
1471 	if (somove(so, M_WAIT)) {
1472 		mtx_enter(&so->so_rcv.sb_mtx);
1473 		mtx_enter(&sosp->so_snd.sb_mtx);
1474 		so->so_rcv.sb_flags |= SB_SPLICE;
1475 		sosp->so_snd.sb_flags |= SB_SPLICE;
1476 		mtx_leave(&sosp->so_snd.sb_mtx);
1477 		mtx_leave(&so->so_rcv.sb_mtx);
1478 	}
1479 	if ((so->so_proto->pr_flags & PR_WANTRCVD) == 0)
1480 		solock(so);
1481 
1482  release:
1483 	sounlock(so);
1484 	sbunlock(&sosp->so_snd);
1485 	sbunlock(&so->so_rcv);
1486  frele:
1487 	FRELE(fp, curproc);
1488 
1489 	return (error);
1490 }
1491 
1492 void
1493 sounsplice(struct socket *so, struct socket *sosp, int freeing)
1494 {
1495 	sbassertlocked(&so->so_rcv);
1496 	soassertlocked(so);
1497 
1498 	task_del(sosplice_taskq, &so->so_splicetask);
1499 	timeout_del(&so->so_idleto);
1500 
1501 	mtx_enter(&so->so_rcv.sb_mtx);
1502 	mtx_enter(&sosp->so_snd.sb_mtx);
1503 	so->so_rcv.sb_flags &= ~SB_SPLICE;
1504 	sosp->so_snd.sb_flags &= ~SB_SPLICE;
1505 	so->so_sp->ssp_socket = sosp->so_sp->ssp_soback = NULL;
1506 	mtx_leave(&sosp->so_snd.sb_mtx);
1507 	mtx_leave(&so->so_rcv.sb_mtx);
1508 
1509 	/* Do not wakeup a socket that is about to be freed. */
1510 	if ((freeing & SOSP_FREEING_READ) == 0 && soreadable(so))
1511 		sorwakeup(so);
1512 	if ((freeing & SOSP_FREEING_WRITE) == 0 && sowriteable(sosp))
1513 		sowwakeup(sosp);
1514 }
1515 
1516 void
1517 soidle(void *arg)
1518 {
1519 	struct socket *so = arg;
1520 
1521 	sblock(&so->so_rcv, SBL_WAIT | SBL_NOINTR);
1522 	solock(so);
1523 	/*
1524 	 * Depending on socket type, sblock(&so->so_rcv) or solock()
1525 	 * is always held while modifying SB_SPLICE and
1526 	 * so->so_sp->ssp_socket.
1527 	 */
1528 	if (so->so_rcv.sb_flags & SB_SPLICE) {
1529 		so->so_error = ETIMEDOUT;
1530 		sounsplice(so, so->so_sp->ssp_socket, 0);
1531 	}
1532 	sounlock(so);
1533 	sbunlock(&so->so_rcv);
1534 }
1535 
1536 void
1537 sotask(void *arg)
1538 {
1539 	struct socket *so = arg;
1540 	int doyield = 0;
1541 	int sockstream = (so->so_proto->pr_flags & PR_WANTRCVD);
1542 
1543 	/*
1544 	 * sblock() on `so_rcv' protects sockets from being unspliced
1545 	 * for UDP case. TCP sockets still rely on solock().
1546 	 */
1547 
1548 	sblock(&so->so_rcv, SBL_WAIT | SBL_NOINTR);
1549 	if (so->so_rcv.sb_flags & SB_SPLICE) {
1550 		struct socket *sosp = so->so_sp->ssp_socket;
1551 
1552 		if (sockstream) {
1553 			sblock(&sosp->so_snd, SBL_WAIT | SBL_NOINTR);
1554 			solock(so);
1555 			doyield = 1;
1556 		}
1557 
1558 		somove(so, M_DONTWAIT);
1559 
1560 		if (sockstream) {
1561 			sounlock(so);
1562 			sbunlock(&sosp->so_snd);
1563 		}
1564 	}
1565 
1566 	sbunlock(&so->so_rcv);
1567 
1568 	if (doyield) {
1569 		/* Avoid user land starvation. */
1570 		yield();
1571 	}
1572 }
1573 
1574 /*
1575  * Move data from receive buffer of spliced source socket to send
1576  * buffer of drain socket.  Try to move as much as possible in one
1577  * big chunk.  It is a TCP only implementation.
1578  * Return value 0 means splicing has been finished, 1 continue.
1579  */
1580 int
1581 somove(struct socket *so, int wait)
1582 {
1583 	struct socket	*sosp = so->so_sp->ssp_socket;
1584 	struct mbuf	*m, **mp, *nextrecord;
1585 	u_long		 len, off, oobmark;
1586 	long		 space;
1587 	int		 error = 0, maxreached = 0, unsplice = 0;
1588 	unsigned int	 rcvstate;
1589 	int		 sockdgram = ((so->so_proto->pr_flags &
1590 			     PR_WANTRCVD) == 0);
1591 
1592 	if (sockdgram)
1593 		sbassertlocked(&so->so_rcv);
1594 	else {
1595 		sbassertlocked(&sosp->so_snd);
1596 		soassertlocked(so);
1597 	}
1598 
1599 	mtx_enter(&so->so_rcv.sb_mtx);
1600 	mtx_enter(&sosp->so_snd.sb_mtx);
1601 
1602  nextpkt:
1603 	if ((error = READ_ONCE(so->so_error)))
1604 		goto release;
1605 	if (sosp->so_snd.sb_state & SS_CANTSENDMORE) {
1606 		error = EPIPE;
1607 		goto release;
1608 	}
1609 
1610 	error = READ_ONCE(sosp->so_error);
1611 	if (error) {
1612 		if (error != ETIMEDOUT && error != EFBIG && error != ELOOP)
1613 			goto release;
1614 		error = 0;
1615 	}
1616 	if ((sosp->so_state & SS_ISCONNECTED) == 0)
1617 		goto release;
1618 
1619 	/* Calculate how many bytes can be copied now. */
1620 	len = so->so_rcv.sb_datacc;
1621 	if (so->so_splicemax) {
1622 		KASSERT(so->so_splicelen < so->so_splicemax);
1623 		if (so->so_splicemax <= so->so_splicelen + len) {
1624 			len = so->so_splicemax - so->so_splicelen;
1625 			maxreached = 1;
1626 		}
1627 	}
1628 	space = sbspace_locked(sosp, &sosp->so_snd);
1629 	if (so->so_oobmark && so->so_oobmark < len &&
1630 	    so->so_oobmark < space + 1024)
1631 		space += 1024;
1632 	if (space <= 0) {
1633 		maxreached = 0;
1634 		goto release;
1635 	}
1636 	if (space < len) {
1637 		maxreached = 0;
1638 		if (space < sosp->so_snd.sb_lowat)
1639 			goto release;
1640 		len = space;
1641 	}
1642 	sosp->so_snd.sb_state |= SS_ISSENDING;
1643 
1644 	SBLASTRECORDCHK(&so->so_rcv, "somove 1");
1645 	SBLASTMBUFCHK(&so->so_rcv, "somove 1");
1646 	m = so->so_rcv.sb_mb;
1647 	if (m == NULL)
1648 		goto release;
1649 	nextrecord = m->m_nextpkt;
1650 
1651 	/* Drop address and control information not used with splicing. */
1652 	if (so->so_proto->pr_flags & PR_ADDR) {
1653 #ifdef DIAGNOSTIC
1654 		if (m->m_type != MT_SONAME)
1655 			panic("somove soname: so %p, so_type %d, m %p, "
1656 			    "m_type %d", so, so->so_type, m, m->m_type);
1657 #endif
1658 		m = m->m_next;
1659 	}
1660 	while (m && m->m_type == MT_CONTROL)
1661 		m = m->m_next;
1662 	if (m == NULL) {
1663 		sbdroprecord(so, &so->so_rcv);
1664 		if (so->so_proto->pr_flags & PR_WANTRCVD) {
1665 			mtx_leave(&sosp->so_snd.sb_mtx);
1666 			mtx_leave(&so->so_rcv.sb_mtx);
1667 			pru_rcvd(so);
1668 			mtx_enter(&so->so_rcv.sb_mtx);
1669 			mtx_enter(&sosp->so_snd.sb_mtx);
1670 		}
1671 		goto nextpkt;
1672 	}
1673 
1674 	/*
1675 	 * By splicing sockets connected to localhost, userland might create a
1676 	 * loop.  Dissolve splicing with error if loop is detected by counter.
1677 	 *
1678 	 * If we deal with looped broadcast/multicast packet we bail out with
1679 	 * no error to suppress splice termination.
1680 	 */
1681 	if ((m->m_flags & M_PKTHDR) &&
1682 	    ((m->m_pkthdr.ph_loopcnt++ >= M_MAXLOOP) ||
1683 	    ((m->m_flags & M_LOOP) && (m->m_flags & (M_BCAST|M_MCAST))))) {
1684 		error = ELOOP;
1685 		goto release;
1686 	}
1687 
1688 	if (so->so_proto->pr_flags & PR_ATOMIC) {
1689 		if ((m->m_flags & M_PKTHDR) == 0)
1690 			panic("somove !PKTHDR: so %p, so_type %d, m %p, "
1691 			    "m_type %d", so, so->so_type, m, m->m_type);
1692 		if (sosp->so_snd.sb_hiwat < m->m_pkthdr.len) {
1693 			error = EMSGSIZE;
1694 			goto release;
1695 		}
1696 		if (len < m->m_pkthdr.len)
1697 			goto release;
1698 		if (m->m_pkthdr.len < len) {
1699 			maxreached = 0;
1700 			len = m->m_pkthdr.len;
1701 		}
1702 		/*
1703 		 * Throw away the name mbuf after it has been assured
1704 		 * that the whole first record can be processed.
1705 		 */
1706 		m = so->so_rcv.sb_mb;
1707 		sbfree(so, &so->so_rcv, m);
1708 		so->so_rcv.sb_mb = m_free(m);
1709 		sbsync(&so->so_rcv, nextrecord);
1710 	}
1711 	/*
1712 	 * Throw away the control mbufs after it has been assured
1713 	 * that the whole first record can be processed.
1714 	 */
1715 	m = so->so_rcv.sb_mb;
1716 	while (m && m->m_type == MT_CONTROL) {
1717 		sbfree(so, &so->so_rcv, m);
1718 		so->so_rcv.sb_mb = m_free(m);
1719 		m = so->so_rcv.sb_mb;
1720 		sbsync(&so->so_rcv, nextrecord);
1721 	}
1722 
1723 	SBLASTRECORDCHK(&so->so_rcv, "somove 2");
1724 	SBLASTMBUFCHK(&so->so_rcv, "somove 2");
1725 
1726 	/* Take at most len mbufs out of receive buffer. */
1727 	for (off = 0, mp = &m; off <= len && *mp;
1728 	    off += (*mp)->m_len, mp = &(*mp)->m_next) {
1729 		u_long size = len - off;
1730 
1731 #ifdef DIAGNOSTIC
1732 		if ((*mp)->m_type != MT_DATA && (*mp)->m_type != MT_HEADER)
1733 			panic("somove type: so %p, so_type %d, m %p, "
1734 			    "m_type %d", so, so->so_type, *mp, (*mp)->m_type);
1735 #endif
1736 		if ((*mp)->m_len > size) {
1737 			/*
1738 			 * Move only a partial mbuf at maximum splice length or
1739 			 * if the drain buffer is too small for this large mbuf.
1740 			 */
1741 			if (!maxreached && sosp->so_snd.sb_datacc > 0) {
1742 				len -= size;
1743 				break;
1744 			}
1745 			*mp = m_copym(so->so_rcv.sb_mb, 0, size, wait);
1746 			if (*mp == NULL) {
1747 				len -= size;
1748 				break;
1749 			}
1750 			so->so_rcv.sb_mb->m_data += size;
1751 			so->so_rcv.sb_mb->m_len -= size;
1752 			so->so_rcv.sb_cc -= size;
1753 			so->so_rcv.sb_datacc -= size;
1754 		} else {
1755 			*mp = so->so_rcv.sb_mb;
1756 			sbfree(so, &so->so_rcv, *mp);
1757 			so->so_rcv.sb_mb = (*mp)->m_next;
1758 			sbsync(&so->so_rcv, nextrecord);
1759 		}
1760 	}
1761 	*mp = NULL;
1762 
1763 	SBLASTRECORDCHK(&so->so_rcv, "somove 3");
1764 	SBLASTMBUFCHK(&so->so_rcv, "somove 3");
1765 	SBCHECK(so, &so->so_rcv);
1766 	if (m == NULL)
1767 		goto release;
1768 	m->m_nextpkt = NULL;
1769 	if (m->m_flags & M_PKTHDR) {
1770 		m_resethdr(m);
1771 		m->m_pkthdr.len = len;
1772 	}
1773 
1774 	/* Send window update to source peer as receive buffer has changed. */
1775 	if (so->so_proto->pr_flags & PR_WANTRCVD) {
1776 		mtx_leave(&sosp->so_snd.sb_mtx);
1777 		mtx_leave(&so->so_rcv.sb_mtx);
1778 		pru_rcvd(so);
1779 		mtx_enter(&so->so_rcv.sb_mtx);
1780 		mtx_enter(&sosp->so_snd.sb_mtx);
1781 	}
1782 
1783 	/* Receive buffer did shrink by len bytes, adjust oob. */
1784 	rcvstate = so->so_rcv.sb_state;
1785 	so->so_rcv.sb_state &= ~SS_RCVATMARK;
1786 	oobmark = so->so_oobmark;
1787 	so->so_oobmark = oobmark > len ? oobmark - len : 0;
1788 	if (oobmark) {
1789 		if (oobmark == len)
1790 			so->so_rcv.sb_state |= SS_RCVATMARK;
1791 		if (oobmark >= len)
1792 			oobmark = 0;
1793 	}
1794 
1795 	/*
1796 	 * Handle oob data.  If any malloc fails, ignore error.
1797 	 * TCP urgent data is not very reliable anyway.
1798 	 */
1799 	while (((rcvstate & SS_RCVATMARK) || oobmark) &&
1800 	    (so->so_options & SO_OOBINLINE)) {
1801 		struct mbuf *o = NULL;
1802 
1803 		if (rcvstate & SS_RCVATMARK) {
1804 			o = m_get(wait, MT_DATA);
1805 			rcvstate &= ~SS_RCVATMARK;
1806 		} else if (oobmark) {
1807 			o = m_split(m, oobmark, wait);
1808 			if (o) {
1809 				mtx_leave(&sosp->so_snd.sb_mtx);
1810 				mtx_leave(&so->so_rcv.sb_mtx);
1811 				error = pru_send(sosp, m, NULL, NULL);
1812 				mtx_enter(&so->so_rcv.sb_mtx);
1813 				mtx_enter(&sosp->so_snd.sb_mtx);
1814 
1815 				if (error) {
1816 					if (sosp->so_snd.sb_state &
1817 					    SS_CANTSENDMORE)
1818 						error = EPIPE;
1819 					m_freem(o);
1820 					goto release;
1821 				}
1822 				len -= oobmark;
1823 				so->so_splicelen += oobmark;
1824 				m = o;
1825 				o = m_get(wait, MT_DATA);
1826 			}
1827 			oobmark = 0;
1828 		}
1829 		if (o) {
1830 			o->m_len = 1;
1831 			*mtod(o, caddr_t) = *mtod(m, caddr_t);
1832 
1833 			mtx_leave(&sosp->so_snd.sb_mtx);
1834 			mtx_leave(&so->so_rcv.sb_mtx);
1835 			error = pru_sendoob(sosp, o, NULL, NULL);
1836 			mtx_enter(&so->so_rcv.sb_mtx);
1837 			mtx_enter(&sosp->so_snd.sb_mtx);
1838 
1839 			if (error) {
1840 				if (sosp->so_snd.sb_state & SS_CANTSENDMORE)
1841 					error = EPIPE;
1842 				m_freem(m);
1843 				goto release;
1844 			}
1845 			len -= 1;
1846 			so->so_splicelen += 1;
1847 			if (oobmark) {
1848 				oobmark -= 1;
1849 				if (oobmark == 0)
1850 					rcvstate |= SS_RCVATMARK;
1851 			}
1852 			m_adj(m, 1);
1853 		}
1854 	}
1855 
1856 	/* Append all remaining data to drain socket. */
1857 	if (so->so_rcv.sb_cc == 0 || maxreached)
1858 		sosp->so_snd.sb_state &= ~SS_ISSENDING;
1859 
1860 	mtx_leave(&sosp->so_snd.sb_mtx);
1861 	mtx_leave(&so->so_rcv.sb_mtx);
1862 
1863 	if (sockdgram)
1864 		solock_shared(sosp);
1865 	error = pru_send(sosp, m, NULL, NULL);
1866 	if (sockdgram)
1867 		sounlock_shared(sosp);
1868 
1869 	mtx_enter(&so->so_rcv.sb_mtx);
1870 	mtx_enter(&sosp->so_snd.sb_mtx);
1871 
1872 	if (error) {
1873 		if (sosp->so_snd.sb_state & SS_CANTSENDMORE ||
1874 		    sosp->so_pcb == NULL)
1875 			error = EPIPE;
1876 		goto release;
1877 	}
1878 	so->so_splicelen += len;
1879 
1880 	/* Move several packets if possible. */
1881 	if (!maxreached && nextrecord)
1882 		goto nextpkt;
1883 
1884  release:
1885 	sosp->so_snd.sb_state &= ~SS_ISSENDING;
1886 
1887 	if (!error && maxreached && so->so_splicemax == so->so_splicelen)
1888 		error = EFBIG;
1889 	if (error)
1890 		WRITE_ONCE(so->so_error, error);
1891 
1892 	if (((so->so_rcv.sb_state & SS_CANTRCVMORE) &&
1893 	    so->so_rcv.sb_cc == 0) ||
1894 	    (sosp->so_snd.sb_state & SS_CANTSENDMORE) ||
1895 	    maxreached || error)
1896 		unsplice = 1;
1897 
1898 	mtx_leave(&sosp->so_snd.sb_mtx);
1899 	mtx_leave(&so->so_rcv.sb_mtx);
1900 
1901 	if (unsplice) {
1902 		if (sockdgram)
1903 			solock(so);
1904 		sounsplice(so, sosp, 0);
1905 		if (sockdgram)
1906 			sounlock(so);
1907 
1908 		return (0);
1909 	}
1910 	if (timerisset(&so->so_idletv))
1911 		timeout_add_tv(&so->so_idleto, &so->so_idletv);
1912 	return (1);
1913 }
1914 #endif /* SOCKET_SPLICE */
1915 
1916 void
1917 sorwakeup(struct socket *so)
1918 {
1919 	if ((so->so_rcv.sb_flags & SB_MTXLOCK) == 0)
1920 		soassertlocked_readonly(so);
1921 
1922 #ifdef SOCKET_SPLICE
1923 	if (so->so_proto->pr_flags & PR_SPLICE) {
1924 		sb_mtx_lock(&so->so_rcv);
1925 		if (so->so_rcv.sb_flags & SB_SPLICE)
1926 			task_add(sosplice_taskq, &so->so_splicetask);
1927 		if (isspliced(so)) {
1928 			sb_mtx_unlock(&so->so_rcv);
1929 			return;
1930 		}
1931 		sb_mtx_unlock(&so->so_rcv);
1932 	}
1933 #endif
1934 	sowakeup(so, &so->so_rcv);
1935 	if (so->so_upcall)
1936 		(*(so->so_upcall))(so, so->so_upcallarg, M_DONTWAIT);
1937 }
1938 
1939 void
1940 sowwakeup(struct socket *so)
1941 {
1942 	if ((so->so_snd.sb_flags & SB_MTXLOCK) == 0)
1943 		soassertlocked_readonly(so);
1944 
1945 #ifdef SOCKET_SPLICE
1946 	if (so->so_proto->pr_flags & PR_SPLICE) {
1947 		sb_mtx_lock(&so->so_snd);
1948 		if (so->so_snd.sb_flags & SB_SPLICE)
1949 			task_add(sosplice_taskq,
1950 			    &so->so_sp->ssp_soback->so_splicetask);
1951 		if (issplicedback(so)) {
1952 			sb_mtx_unlock(&so->so_snd);
1953 			return;
1954 		}
1955 		sb_mtx_unlock(&so->so_snd);
1956 	}
1957 #endif
1958 	sowakeup(so, &so->so_snd);
1959 }
1960 
1961 int
1962 sosetopt(struct socket *so, int level, int optname, struct mbuf *m)
1963 {
1964 	int error = 0;
1965 
1966 	if (level != SOL_SOCKET) {
1967 		if (so->so_proto->pr_ctloutput) {
1968 			solock(so);
1969 			error = (*so->so_proto->pr_ctloutput)(PRCO_SETOPT, so,
1970 			    level, optname, m);
1971 			sounlock(so);
1972 			return (error);
1973 		}
1974 		error = ENOPROTOOPT;
1975 	} else {
1976 		switch (optname) {
1977 
1978 		case SO_LINGER:
1979 			if (m == NULL || m->m_len != sizeof (struct linger) ||
1980 			    mtod(m, struct linger *)->l_linger < 0 ||
1981 			    mtod(m, struct linger *)->l_linger > SHRT_MAX)
1982 				return (EINVAL);
1983 
1984 			solock(so);
1985 			so->so_linger = mtod(m, struct linger *)->l_linger;
1986 			if (*mtod(m, int *))
1987 				so->so_options |= optname;
1988 			else
1989 				so->so_options &= ~optname;
1990 			sounlock(so);
1991 
1992 			break;
1993 		case SO_BINDANY:
1994 			if ((error = suser(curproc)) != 0)	/* XXX */
1995 				return (error);
1996 			/* FALLTHROUGH */
1997 
1998 		case SO_DEBUG:
1999 		case SO_KEEPALIVE:
2000 		case SO_USELOOPBACK:
2001 		case SO_BROADCAST:
2002 		case SO_REUSEADDR:
2003 		case SO_REUSEPORT:
2004 		case SO_OOBINLINE:
2005 		case SO_TIMESTAMP:
2006 		case SO_ZEROIZE:
2007 			if (m == NULL || m->m_len < sizeof (int))
2008 				return (EINVAL);
2009 
2010 			solock(so);
2011 			if (*mtod(m, int *))
2012 				so->so_options |= optname;
2013 			else
2014 				so->so_options &= ~optname;
2015 			sounlock(so);
2016 
2017 			break;
2018 		case SO_DONTROUTE:
2019 			if (m == NULL || m->m_len < sizeof (int))
2020 				return (EINVAL);
2021 			if (*mtod(m, int *))
2022 				error = EOPNOTSUPP;
2023 			break;
2024 
2025 		case SO_SNDBUF:
2026 		case SO_RCVBUF:
2027 		case SO_SNDLOWAT:
2028 		case SO_RCVLOWAT:
2029 		    {
2030 			struct sockbuf *sb = (optname == SO_SNDBUF ||
2031 			    optname == SO_SNDLOWAT ?
2032 			    &so->so_snd : &so->so_rcv);
2033 			u_long cnt;
2034 
2035 			if (m == NULL || m->m_len < sizeof (int))
2036 				return (EINVAL);
2037 			cnt = *mtod(m, int *);
2038 			if ((long)cnt <= 0)
2039 				cnt = 1;
2040 
2041 			if (((sb->sb_flags & SB_MTXLOCK) == 0))
2042 				solock(so);
2043 			mtx_enter(&sb->sb_mtx);
2044 
2045 			switch (optname) {
2046 			case SO_SNDBUF:
2047 			case SO_RCVBUF:
2048 				if (sb->sb_state &
2049 				    (SS_CANTSENDMORE | SS_CANTRCVMORE)) {
2050 					error = EINVAL;
2051 					break;
2052 				}
2053 				if (sbcheckreserve(cnt, sb->sb_wat) ||
2054 				    sbreserve(so, sb, cnt)) {
2055 					error = ENOBUFS;
2056 					break;
2057 				}
2058 				sb->sb_wat = cnt;
2059 				break;
2060 			case SO_SNDLOWAT:
2061 			case SO_RCVLOWAT:
2062 				sb->sb_lowat = (cnt > sb->sb_hiwat) ?
2063 				    sb->sb_hiwat : cnt;
2064 				break;
2065 			}
2066 
2067 			mtx_leave(&sb->sb_mtx);
2068 			if (((sb->sb_flags & SB_MTXLOCK) == 0))
2069 				sounlock(so);
2070 
2071 			break;
2072 		    }
2073 
2074 		case SO_SNDTIMEO:
2075 		case SO_RCVTIMEO:
2076 		    {
2077 			struct sockbuf *sb = (optname == SO_SNDTIMEO ?
2078 			    &so->so_snd : &so->so_rcv);
2079 			struct timeval tv;
2080 			uint64_t nsecs;
2081 
2082 			if (m == NULL || m->m_len < sizeof (tv))
2083 				return (EINVAL);
2084 			memcpy(&tv, mtod(m, struct timeval *), sizeof tv);
2085 			if (!timerisvalid(&tv))
2086 				return (EINVAL);
2087 			nsecs = TIMEVAL_TO_NSEC(&tv);
2088 			if (nsecs == UINT64_MAX)
2089 				return (EDOM);
2090 			if (nsecs == 0)
2091 				nsecs = INFSLP;
2092 
2093 			mtx_enter(&sb->sb_mtx);
2094 			sb->sb_timeo_nsecs = nsecs;
2095 			mtx_leave(&sb->sb_mtx);
2096 			break;
2097 		    }
2098 
2099 		case SO_RTABLE:
2100 			if (so->so_proto->pr_domain &&
2101 			    so->so_proto->pr_domain->dom_protosw &&
2102 			    so->so_proto->pr_ctloutput) {
2103 				const struct domain *dom =
2104 				    so->so_proto->pr_domain;
2105 
2106 				level = dom->dom_protosw->pr_protocol;
2107 				solock(so);
2108 				error = (*so->so_proto->pr_ctloutput)
2109 				    (PRCO_SETOPT, so, level, optname, m);
2110 				sounlock(so);
2111 			} else
2112 				error = ENOPROTOOPT;
2113 			break;
2114 #ifdef SOCKET_SPLICE
2115 		case SO_SPLICE:
2116 			if (m == NULL) {
2117 				error = sosplice(so, -1, 0, NULL);
2118 			} else if (m->m_len < sizeof(int)) {
2119 				error = EINVAL;
2120 			} else if (m->m_len < sizeof(struct splice)) {
2121 				error = sosplice(so, *mtod(m, int *), 0, NULL);
2122 			} else {
2123 				error = sosplice(so,
2124 				    mtod(m, struct splice *)->sp_fd,
2125 				    mtod(m, struct splice *)->sp_max,
2126 				   &mtod(m, struct splice *)->sp_idle);
2127 			}
2128 			break;
2129 #endif /* SOCKET_SPLICE */
2130 
2131 		default:
2132 			error = ENOPROTOOPT;
2133 			break;
2134 		}
2135 	}
2136 
2137 	return (error);
2138 }
2139 
2140 int
2141 sogetopt(struct socket *so, int level, int optname, struct mbuf *m)
2142 {
2143 	int error = 0;
2144 
2145 	if (level != SOL_SOCKET) {
2146 		if (so->so_proto->pr_ctloutput) {
2147 			m->m_len = 0;
2148 
2149 			solock(so);
2150 			error = (*so->so_proto->pr_ctloutput)(PRCO_GETOPT, so,
2151 			    level, optname, m);
2152 			sounlock(so);
2153 			return (error);
2154 		} else
2155 			return (ENOPROTOOPT);
2156 	} else {
2157 		m->m_len = sizeof (int);
2158 
2159 		switch (optname) {
2160 
2161 		case SO_LINGER:
2162 			m->m_len = sizeof (struct linger);
2163 			solock_shared(so);
2164 			mtod(m, struct linger *)->l_onoff =
2165 				so->so_options & SO_LINGER;
2166 			mtod(m, struct linger *)->l_linger = so->so_linger;
2167 			sounlock_shared(so);
2168 			break;
2169 
2170 		case SO_BINDANY:
2171 		case SO_USELOOPBACK:
2172 		case SO_DEBUG:
2173 		case SO_KEEPALIVE:
2174 		case SO_REUSEADDR:
2175 		case SO_REUSEPORT:
2176 		case SO_BROADCAST:
2177 		case SO_OOBINLINE:
2178 		case SO_ACCEPTCONN:
2179 		case SO_TIMESTAMP:
2180 		case SO_ZEROIZE:
2181 			*mtod(m, int *) = so->so_options & optname;
2182 			break;
2183 
2184 		case SO_DONTROUTE:
2185 			*mtod(m, int *) = 0;
2186 			break;
2187 
2188 		case SO_TYPE:
2189 			*mtod(m, int *) = so->so_type;
2190 			break;
2191 
2192 		case SO_ERROR:
2193 			solock(so);
2194 			*mtod(m, int *) = so->so_error;
2195 			so->so_error = 0;
2196 			sounlock(so);
2197 
2198 			break;
2199 
2200 		case SO_DOMAIN:
2201 			*mtod(m, int *) = so->so_proto->pr_domain->dom_family;
2202 			break;
2203 
2204 		case SO_PROTOCOL:
2205 			*mtod(m, int *) = so->so_proto->pr_protocol;
2206 			break;
2207 
2208 		case SO_SNDBUF:
2209 			*mtod(m, int *) = so->so_snd.sb_hiwat;
2210 			break;
2211 
2212 		case SO_RCVBUF:
2213 			*mtod(m, int *) = so->so_rcv.sb_hiwat;
2214 			break;
2215 
2216 		case SO_SNDLOWAT:
2217 			*mtod(m, int *) = so->so_snd.sb_lowat;
2218 			break;
2219 
2220 		case SO_RCVLOWAT:
2221 			*mtod(m, int *) = so->so_rcv.sb_lowat;
2222 			break;
2223 
2224 		case SO_SNDTIMEO:
2225 		case SO_RCVTIMEO:
2226 		    {
2227 			struct sockbuf *sb = (optname == SO_SNDTIMEO ?
2228 			    &so->so_snd : &so->so_rcv);
2229 			struct timeval tv;
2230 			uint64_t nsecs;
2231 
2232 			mtx_enter(&sb->sb_mtx);
2233 			nsecs = sb->sb_timeo_nsecs;
2234 			mtx_leave(&sb->sb_mtx);
2235 
2236 			m->m_len = sizeof(struct timeval);
2237 			memset(&tv, 0, sizeof(tv));
2238 			if (nsecs != INFSLP)
2239 				NSEC_TO_TIMEVAL(nsecs, &tv);
2240 			memcpy(mtod(m, struct timeval *), &tv, sizeof tv);
2241 			break;
2242 		    }
2243 
2244 		case SO_RTABLE:
2245 			if (so->so_proto->pr_domain &&
2246 			    so->so_proto->pr_domain->dom_protosw &&
2247 			    so->so_proto->pr_ctloutput) {
2248 				const struct domain *dom =
2249 				    so->so_proto->pr_domain;
2250 
2251 				level = dom->dom_protosw->pr_protocol;
2252 				solock(so);
2253 				error = (*so->so_proto->pr_ctloutput)
2254 				    (PRCO_GETOPT, so, level, optname, m);
2255 				sounlock(so);
2256 				if (error)
2257 					return (error);
2258 				break;
2259 			}
2260 			return (ENOPROTOOPT);
2261 
2262 #ifdef SOCKET_SPLICE
2263 		case SO_SPLICE:
2264 		    {
2265 			off_t len;
2266 
2267 			m->m_len = sizeof(off_t);
2268 			solock_shared(so);
2269 			len = so->so_sp ? so->so_sp->ssp_len : 0;
2270 			sounlock_shared(so);
2271 			memcpy(mtod(m, off_t *), &len, sizeof(off_t));
2272 			break;
2273 		    }
2274 #endif /* SOCKET_SPLICE */
2275 
2276 		case SO_PEERCRED:
2277 			if (so->so_proto->pr_protocol == AF_UNIX) {
2278 				struct unpcb *unp = sotounpcb(so);
2279 
2280 				solock(so);
2281 				if (unp->unp_flags & UNP_FEIDS) {
2282 					m->m_len = sizeof(unp->unp_connid);
2283 					memcpy(mtod(m, caddr_t),
2284 					    &(unp->unp_connid), m->m_len);
2285 					sounlock(so);
2286 					break;
2287 				}
2288 				sounlock(so);
2289 
2290 				return (ENOTCONN);
2291 			}
2292 			return (EOPNOTSUPP);
2293 
2294 		default:
2295 			return (ENOPROTOOPT);
2296 		}
2297 		return (0);
2298 	}
2299 }
2300 
2301 void
2302 sohasoutofband(struct socket *so)
2303 {
2304 	pgsigio(&so->so_sigio, SIGURG, 0);
2305 	knote(&so->so_rcv.sb_klist, 0);
2306 }
2307 
2308 void
2309 sofilt_lock(struct socket *so, struct sockbuf *sb)
2310 {
2311 	switch (so->so_proto->pr_domain->dom_family) {
2312 	case PF_INET:
2313 	case PF_INET6:
2314 		NET_LOCK_SHARED();
2315 		break;
2316 	default:
2317 		rw_enter_write(&so->so_lock);
2318 		break;
2319 	}
2320 
2321 	mtx_enter(&sb->sb_mtx);
2322 }
2323 
2324 void
2325 sofilt_unlock(struct socket *so, struct sockbuf *sb)
2326 {
2327 	mtx_leave(&sb->sb_mtx);
2328 
2329 	switch (so->so_proto->pr_domain->dom_family) {
2330 	case PF_INET:
2331 	case PF_INET6:
2332 		NET_UNLOCK_SHARED();
2333 		break;
2334 	default:
2335 		rw_exit_write(&so->so_lock);
2336 		break;
2337 	}
2338 }
2339 
2340 int
2341 soo_kqfilter(struct file *fp, struct knote *kn)
2342 {
2343 	struct socket *so = kn->kn_fp->f_data;
2344 	struct sockbuf *sb;
2345 
2346 	switch (kn->kn_filter) {
2347 	case EVFILT_READ:
2348 		kn->kn_fop = &soread_filtops;
2349 		sb = &so->so_rcv;
2350 		break;
2351 	case EVFILT_WRITE:
2352 		kn->kn_fop = &sowrite_filtops;
2353 		sb = &so->so_snd;
2354 		break;
2355 	case EVFILT_EXCEPT:
2356 		kn->kn_fop = &soexcept_filtops;
2357 		sb = &so->so_rcv;
2358 		break;
2359 	default:
2360 		return (EINVAL);
2361 	}
2362 
2363 	klist_insert(&sb->sb_klist, kn);
2364 
2365 	return (0);
2366 }
2367 
2368 void
2369 filt_sordetach(struct knote *kn)
2370 {
2371 	struct socket *so = kn->kn_fp->f_data;
2372 
2373 	klist_remove(&so->so_rcv.sb_klist, kn);
2374 }
2375 
2376 int
2377 filt_soread(struct knote *kn, long hint)
2378 {
2379 	struct socket *so = kn->kn_fp->f_data;
2380 	u_int state = READ_ONCE(so->so_state);
2381 	u_int error = READ_ONCE(so->so_error);
2382 	int rv = 0;
2383 
2384 	MUTEX_ASSERT_LOCKED(&so->so_rcv.sb_mtx);
2385 	if ((so->so_rcv.sb_flags & SB_MTXLOCK) == 0)
2386 		soassertlocked_readonly(so);
2387 
2388 	if (so->so_options & SO_ACCEPTCONN) {
2389 		short qlen = READ_ONCE(so->so_qlen);
2390 
2391 		if (so->so_rcv.sb_flags & SB_MTXLOCK)
2392 			soassertlocked_readonly(so);
2393 
2394 		kn->kn_data = qlen;
2395 		rv = (kn->kn_data != 0);
2396 
2397 		if (kn->kn_flags & (__EV_POLL | __EV_SELECT)) {
2398 			if (state & SS_ISDISCONNECTED) {
2399 				kn->kn_flags |= __EV_HUP;
2400 				rv = 1;
2401 			} else {
2402 				rv = qlen || soreadable(so);
2403 			}
2404 		}
2405 
2406 		return rv;
2407 	}
2408 
2409 	kn->kn_data = so->so_rcv.sb_cc;
2410 #ifdef SOCKET_SPLICE
2411 	if (isspliced(so)) {
2412 		rv = 0;
2413 	} else
2414 #endif /* SOCKET_SPLICE */
2415 	if (so->so_rcv.sb_state & SS_CANTRCVMORE) {
2416 		kn->kn_flags |= EV_EOF;
2417 		if (kn->kn_flags & __EV_POLL) {
2418 			if (state & SS_ISDISCONNECTED)
2419 				kn->kn_flags |= __EV_HUP;
2420 		}
2421 		kn->kn_fflags = error;
2422 		rv = 1;
2423 	} else if (error) {
2424 		rv = 1;
2425 	} else if (kn->kn_sfflags & NOTE_LOWAT) {
2426 		rv = (kn->kn_data >= kn->kn_sdata);
2427 	} else {
2428 		rv = (kn->kn_data >= so->so_rcv.sb_lowat);
2429 	}
2430 
2431 	return rv;
2432 }
2433 
2434 void
2435 filt_sowdetach(struct knote *kn)
2436 {
2437 	struct socket *so = kn->kn_fp->f_data;
2438 
2439 	klist_remove(&so->so_snd.sb_klist, kn);
2440 }
2441 
2442 int
2443 filt_sowrite(struct knote *kn, long hint)
2444 {
2445 	struct socket *so = kn->kn_fp->f_data;
2446 	u_int state = READ_ONCE(so->so_state);
2447 	u_int error = READ_ONCE(so->so_error);
2448 	int rv;
2449 
2450 	MUTEX_ASSERT_LOCKED(&so->so_snd.sb_mtx);
2451 	if ((so->so_snd.sb_flags & SB_MTXLOCK) == 0)
2452 		soassertlocked_readonly(so);
2453 
2454 	kn->kn_data = sbspace_locked(so, &so->so_snd);
2455 	if (so->so_snd.sb_state & SS_CANTSENDMORE) {
2456 		kn->kn_flags |= EV_EOF;
2457 		if (kn->kn_flags & __EV_POLL) {
2458 			if (state & SS_ISDISCONNECTED)
2459 				kn->kn_flags |= __EV_HUP;
2460 		}
2461 		kn->kn_fflags = error;
2462 		rv = 1;
2463 	} else if (error) {
2464 		rv = 1;
2465 	} else if (((state & SS_ISCONNECTED) == 0) &&
2466 	    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
2467 		rv = 0;
2468 	} else if (kn->kn_sfflags & NOTE_LOWAT) {
2469 		rv = (kn->kn_data >= kn->kn_sdata);
2470 	} else {
2471 		rv = (kn->kn_data >= so->so_snd.sb_lowat);
2472 	}
2473 
2474 	return (rv);
2475 }
2476 
2477 int
2478 filt_soexcept(struct knote *kn, long hint)
2479 {
2480 	struct socket *so = kn->kn_fp->f_data;
2481 	int rv = 0;
2482 
2483 	MUTEX_ASSERT_LOCKED(&so->so_rcv.sb_mtx);
2484 	if ((so->so_rcv.sb_flags & SB_MTXLOCK) == 0)
2485 		soassertlocked_readonly(so);
2486 
2487 #ifdef SOCKET_SPLICE
2488 	if (isspliced(so)) {
2489 		rv = 0;
2490 	} else
2491 #endif /* SOCKET_SPLICE */
2492 	if (kn->kn_sfflags & NOTE_OOB) {
2493 		if (so->so_oobmark || (so->so_rcv.sb_state & SS_RCVATMARK)) {
2494 			kn->kn_fflags |= NOTE_OOB;
2495 			kn->kn_data -= so->so_oobmark;
2496 			rv = 1;
2497 		}
2498 	}
2499 
2500 	if (kn->kn_flags & __EV_POLL) {
2501 		u_int state = READ_ONCE(so->so_state);
2502 
2503 		if (state & SS_ISDISCONNECTED) {
2504 			kn->kn_flags |= __EV_HUP;
2505 			rv = 1;
2506 		}
2507 	}
2508 
2509 	return rv;
2510 }
2511 
2512 int
2513 filt_sowmodify(struct kevent *kev, struct knote *kn)
2514 {
2515 	struct socket *so = kn->kn_fp->f_data;
2516 	int rv;
2517 
2518 	sofilt_lock(so, &so->so_snd);
2519 	rv = knote_modify(kev, kn);
2520 	sofilt_unlock(so, &so->so_snd);
2521 
2522 	return (rv);
2523 }
2524 
2525 int
2526 filt_sowprocess(struct knote *kn, struct kevent *kev)
2527 {
2528 	struct socket *so = kn->kn_fp->f_data;
2529 	int rv;
2530 
2531 	sofilt_lock(so, &so->so_snd);
2532 	rv = knote_process(kn, kev);
2533 	sofilt_unlock(so, &so->so_snd);
2534 
2535 	return (rv);
2536 }
2537 
2538 int
2539 filt_sormodify(struct kevent *kev, struct knote *kn)
2540 {
2541 	struct socket *so = kn->kn_fp->f_data;
2542 	int rv;
2543 
2544 	sofilt_lock(so, &so->so_rcv);
2545 	rv = knote_modify(kev, kn);
2546 	sofilt_unlock(so, &so->so_rcv);
2547 
2548 	return (rv);
2549 }
2550 
2551 int
2552 filt_sorprocess(struct knote *kn, struct kevent *kev)
2553 {
2554 	struct socket *so = kn->kn_fp->f_data;
2555 	int rv;
2556 
2557 	sofilt_lock(so, &so->so_rcv);
2558 	rv = knote_process(kn, kev);
2559 	sofilt_unlock(so, &so->so_rcv);
2560 
2561 	return (rv);
2562 }
2563 
2564 #ifdef DDB
2565 void
2566 sobuf_print(struct sockbuf *,
2567     int (*)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))));
2568 
2569 void
2570 sobuf_print(struct sockbuf *sb,
2571     int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))))
2572 {
2573 	(*pr)("\tsb_cc: %lu\n", sb->sb_cc);
2574 	(*pr)("\tsb_datacc: %lu\n", sb->sb_datacc);
2575 	(*pr)("\tsb_hiwat: %lu\n", sb->sb_hiwat);
2576 	(*pr)("\tsb_wat: %lu\n", sb->sb_wat);
2577 	(*pr)("\tsb_mbcnt: %lu\n", sb->sb_mbcnt);
2578 	(*pr)("\tsb_mbmax: %lu\n", sb->sb_mbmax);
2579 	(*pr)("\tsb_lowat: %ld\n", sb->sb_lowat);
2580 	(*pr)("\tsb_mb: %p\n", sb->sb_mb);
2581 	(*pr)("\tsb_mbtail: %p\n", sb->sb_mbtail);
2582 	(*pr)("\tsb_lastrecord: %p\n", sb->sb_lastrecord);
2583 	(*pr)("\tsb_flags: %04x\n", sb->sb_flags);
2584 	(*pr)("\tsb_state: %04x\n", sb->sb_state);
2585 	(*pr)("\tsb_timeo_nsecs: %llu\n", sb->sb_timeo_nsecs);
2586 }
2587 
2588 void
2589 so_print(void *v,
2590     int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))))
2591 {
2592 	struct socket *so = v;
2593 
2594 	(*pr)("socket %p\n", so);
2595 	(*pr)("so_type: %i\n", so->so_type);
2596 	(*pr)("so_options: 0x%04x\n", so->so_options); /* %b */
2597 	(*pr)("so_linger: %i\n", so->so_linger);
2598 	(*pr)("so_state: 0x%04x\n", so->so_state);
2599 	(*pr)("so_pcb: %p\n", so->so_pcb);
2600 	(*pr)("so_proto: %p\n", so->so_proto);
2601 	(*pr)("so_sigio: %p\n", so->so_sigio.sir_sigio);
2602 
2603 	(*pr)("so_head: %p\n", so->so_head);
2604 	(*pr)("so_onq: %p\n", so->so_onq);
2605 	(*pr)("so_q0: @%p first: %p\n", &so->so_q0, TAILQ_FIRST(&so->so_q0));
2606 	(*pr)("so_q: @%p first: %p\n", &so->so_q, TAILQ_FIRST(&so->so_q));
2607 	(*pr)("so_eq: next: %p\n", TAILQ_NEXT(so, so_qe));
2608 	(*pr)("so_q0len: %i\n", so->so_q0len);
2609 	(*pr)("so_qlen: %i\n", so->so_qlen);
2610 	(*pr)("so_qlimit: %i\n", so->so_qlimit);
2611 	(*pr)("so_timeo: %i\n", so->so_timeo);
2612 	(*pr)("so_obmark: %lu\n", so->so_oobmark);
2613 
2614 	(*pr)("so_sp: %p\n", so->so_sp);
2615 	if (so->so_sp != NULL) {
2616 		(*pr)("\tssp_socket: %p\n", so->so_sp->ssp_socket);
2617 		(*pr)("\tssp_soback: %p\n", so->so_sp->ssp_soback);
2618 		(*pr)("\tssp_len: %lld\n",
2619 		    (unsigned long long)so->so_sp->ssp_len);
2620 		(*pr)("\tssp_max: %lld\n",
2621 		    (unsigned long long)so->so_sp->ssp_max);
2622 		(*pr)("\tssp_idletv: %lld %ld\n", so->so_sp->ssp_idletv.tv_sec,
2623 		    so->so_sp->ssp_idletv.tv_usec);
2624 		(*pr)("\tssp_idleto: %spending (@%i)\n",
2625 		    timeout_pending(&so->so_sp->ssp_idleto) ? "" : "not ",
2626 		    so->so_sp->ssp_idleto.to_time);
2627 	}
2628 
2629 	(*pr)("so_rcv:\n");
2630 	sobuf_print(&so->so_rcv, pr);
2631 	(*pr)("so_snd:\n");
2632 	sobuf_print(&so->so_snd, pr);
2633 
2634 	(*pr)("so_upcall: %p so_upcallarg: %p\n",
2635 	    so->so_upcall, so->so_upcallarg);
2636 
2637 	(*pr)("so_euid: %d so_ruid: %d\n", so->so_euid, so->so_ruid);
2638 	(*pr)("so_egid: %d so_rgid: %d\n", so->so_egid, so->so_rgid);
2639 	(*pr)("so_cpid: %d\n", so->so_cpid);
2640 }
2641 #endif
2642