xref: /openbsd-src/sys/kern/uipc_socket.c (revision c5202efadda0c487890a6e959e19d379d7f83f6f)
1 /*	$OpenBSD: uipc_socket.c,v 1.349 2024/12/27 10:18:04 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 #define SOSP_FREEING_READ	1
272 #define SOSP_FREEING_WRITE	2
273 void
274 sofree(struct socket *so, int keep_lock)
275 {
276 	int persocket = solock_persocket(so);
277 
278 	soassertlocked(so);
279 
280 	if (so->so_pcb || (so->so_state & SS_NOFDREF) == 0) {
281 		if (!keep_lock)
282 			sounlock(so);
283 		return;
284 	}
285 	if (so->so_head) {
286 		struct socket *head = so->so_head;
287 
288 		/*
289 		 * We must not decommission a socket that's on the accept(2)
290 		 * queue.  If we do, then accept(2) may hang after select(2)
291 		 * indicated that the listening socket was ready.
292 		 */
293 		if (so->so_onq == &head->so_q) {
294 			if (!keep_lock)
295 				sounlock(so);
296 			return;
297 		}
298 
299 		if (persocket) {
300 			/*
301 			 * Concurrent close of `head' could
302 			 * abort `so' due to re-lock.
303 			 */
304 			soref(so);
305 			soref(head);
306 			sounlock(so);
307 			solock(head);
308 			solock(so);
309 
310 			if (so->so_onq != &head->so_q0) {
311 				sounlock(head);
312 				sounlock(so);
313 				sorele(head);
314 				sorele(so);
315 				return;
316 			}
317 
318 			sorele(head);
319 			sorele(so);
320 		}
321 
322 		soqremque(so, 0);
323 
324 		if (persocket)
325 			sounlock(head);
326 	}
327 
328 	if (!keep_lock) {
329 		/*
330 		 * sofree() was called from soclose(). Sleep is safe
331 		 * even for tcp(4) sockets.
332 		 */
333 		sounlock(so);
334 		refcnt_finalize(&so->so_refcnt, "sofinal");
335 		solock(so);
336 	}
337 
338 	sigio_free(&so->so_sigio);
339 	klist_free(&so->so_rcv.sb_klist);
340 	klist_free(&so->so_snd.sb_klist);
341 
342 	mtx_enter(&so->so_snd.sb_mtx);
343 	sbrelease(so, &so->so_snd);
344 	mtx_leave(&so->so_snd.sb_mtx);
345 
346 	/*
347 	 * Unlocked dispose and cleanup is safe. Socket is unlinked
348 	 * from everywhere. Even concurrent sotask() thread will not
349 	 * call somove().
350 	 */
351 	if (so->so_proto->pr_flags & PR_RIGHTS &&
352 	    so->so_proto->pr_domain->dom_dispose)
353 		(*so->so_proto->pr_domain->dom_dispose)(so->so_rcv.sb_mb);
354 	m_purge(so->so_rcv.sb_mb);
355 
356 	if (!keep_lock) {
357 		sounlock(so);
358 
359 #ifdef SOCKET_SPLICE
360 		if (so->so_sp) {
361 			timeout_del_barrier(&so->so_sp->ssp_idleto);
362 			task_del(sosplice_taskq, &so->so_sp->ssp_task);
363 			taskq_barrier(sosplice_taskq);
364 			pool_put(&sosplice_pool, so->so_sp);
365 		}
366 #endif /* SOCKET_SPLICE */
367 	}
368 
369 	pool_put(&socket_pool, so);
370 }
371 
372 static inline uint64_t
373 solinger_nsec(struct socket *so)
374 {
375 	if (so->so_linger == 0)
376 		return INFSLP;
377 
378 	return SEC_TO_NSEC(so->so_linger);
379 }
380 
381 /*
382  * Close a socket on last file table reference removal.
383  * Initiate disconnect if connected.
384  * Free socket when disconnect complete.
385  */
386 int
387 soclose(struct socket *so, int flags)
388 {
389 	struct socket *so2;
390 	int error = 0;
391 
392 	solock(so);
393 	/* Revoke async IO early. There is a final revocation in sofree(). */
394 	sigio_free(&so->so_sigio);
395 	if (so->so_state & SS_ISCONNECTED) {
396 		if (so->so_pcb == NULL)
397 			goto discard;
398 		if ((so->so_state & SS_ISDISCONNECTING) == 0) {
399 			error = sodisconnect(so);
400 			if (error)
401 				goto drop;
402 		}
403 		if (so->so_options & SO_LINGER) {
404 			if ((so->so_state & SS_ISDISCONNECTING) &&
405 			    (flags & MSG_DONTWAIT))
406 				goto drop;
407 			while (so->so_state & SS_ISCONNECTED) {
408 				error = sosleep_nsec(so, &so->so_timeo,
409 				    PSOCK | PCATCH, "netcls",
410 				    solinger_nsec(so));
411 				if (error)
412 					break;
413 			}
414 		}
415 	}
416 drop:
417 	if (so->so_pcb) {
418 		int error2;
419 		error2 = pru_detach(so);
420 		if (error == 0)
421 			error = error2;
422 	}
423 	if (so->so_options & SO_ACCEPTCONN) {
424 		int persocket = solock_persocket(so);
425 
426 		while ((so2 = TAILQ_FIRST(&so->so_q0)) != NULL) {
427 			if (persocket)
428 				solock(so2);
429 			(void) soqremque(so2, 0);
430 			if (persocket)
431 				sounlock(so);
432 			soabort(so2);
433 			if (persocket)
434 				solock(so);
435 		}
436 		while ((so2 = TAILQ_FIRST(&so->so_q)) != NULL) {
437 			if (persocket)
438 				solock(so2);
439 			(void) soqremque(so2, 1);
440 			if (persocket)
441 				sounlock(so);
442 			soabort(so2);
443 			if (persocket)
444 				solock(so);
445 		}
446 	}
447 discard:
448 #ifdef SOCKET_SPLICE
449 	if (so->so_sp) {
450 		struct socket *soback;
451 
452 		sounlock(so);
453 		mtx_enter(&so->so_snd.sb_mtx);
454 		/*
455 		 * Concurrent sounsplice() locks `sb_mtx' mutexes on
456 		 * both `so_snd' and `so_rcv' before unsplice sockets.
457 		 */
458 		if ((soback = so->so_sp->ssp_soback) == NULL) {
459 			mtx_leave(&so->so_snd.sb_mtx);
460 			goto notsplicedback;
461 		}
462 		soref(soback);
463 		mtx_leave(&so->so_snd.sb_mtx);
464 
465 		/*
466 		 * `so' can be only unspliced, and never spliced again.
467 		 * Thus if issplicedback(so) check is positive, socket is
468 		 * still spliced and `ssp_soback' points to the same
469 		 * socket that `soback'.
470 		 */
471 		sblock(&soback->so_rcv, SBL_WAIT | SBL_NOINTR);
472 		if (issplicedback(so)) {
473 			int freeing = SOSP_FREEING_WRITE;
474 
475 			if (so->so_sp->ssp_soback == so)
476 				freeing |= SOSP_FREEING_READ;
477 			solock(soback);
478 			sounsplice(so->so_sp->ssp_soback, so, freeing);
479 			sounlock(soback);
480 		}
481 		sbunlock(&soback->so_rcv);
482 		sorele(soback);
483 
484 notsplicedback:
485 		sblock(&so->so_rcv, SBL_WAIT | SBL_NOINTR);
486 		if (isspliced(so)) {
487 			int freeing = SOSP_FREEING_READ;
488 
489 			if (so == so->so_sp->ssp_socket)
490 				freeing |= SOSP_FREEING_WRITE;
491 			solock(so);
492 			sounsplice(so, so->so_sp->ssp_socket, freeing);
493 			sounlock(so);
494 		}
495 		sbunlock(&so->so_rcv);
496 
497 		solock(so);
498 	}
499 #endif /* SOCKET_SPLICE */
500 
501 	if (so->so_state & SS_NOFDREF)
502 		panic("soclose NOFDREF: so %p, so_type %d", so, so->so_type);
503 	so->so_state |= SS_NOFDREF;
504 
505 	/* sofree() calls sounlock(). */
506 	sofree(so, 0);
507 	return (error);
508 }
509 
510 void
511 soabort(struct socket *so)
512 {
513 	soassertlocked(so);
514 	pru_abort(so);
515 }
516 
517 int
518 soaccept(struct socket *so, struct mbuf *nam)
519 {
520 	int error = 0;
521 
522 	soassertlocked(so);
523 
524 	if ((so->so_state & SS_NOFDREF) == 0)
525 		panic("soaccept !NOFDREF: so %p, so_type %d", so, so->so_type);
526 	so->so_state &= ~SS_NOFDREF;
527 	if ((so->so_state & SS_ISDISCONNECTED) == 0 ||
528 	    (so->so_proto->pr_flags & PR_ABRTACPTDIS) == 0)
529 		error = pru_accept(so, nam);
530 	else
531 		error = ECONNABORTED;
532 	return (error);
533 }
534 
535 int
536 soconnect(struct socket *so, struct mbuf *nam)
537 {
538 	int error;
539 
540 	soassertlocked(so);
541 
542 	if (so->so_options & SO_ACCEPTCONN)
543 		return (EOPNOTSUPP);
544 	/*
545 	 * If protocol is connection-based, can only connect once.
546 	 * Otherwise, if connected, try to disconnect first.
547 	 * This allows user to disconnect by connecting to, e.g.,
548 	 * a null address.
549 	 */
550 	if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
551 	    ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
552 	    (error = sodisconnect(so))))
553 		error = EISCONN;
554 	else
555 		error = pru_connect(so, nam);
556 	return (error);
557 }
558 
559 int
560 soconnect2(struct socket *so1, struct socket *so2)
561 {
562 	int persocket, error;
563 
564 	if ((persocket = solock_persocket(so1)))
565 		solock_pair(so1, so2);
566 	else
567 		solock(so1);
568 
569 	error = pru_connect2(so1, so2);
570 
571 	if (persocket)
572 		sounlock(so2);
573 	sounlock(so1);
574 	return (error);
575 }
576 
577 int
578 sodisconnect(struct socket *so)
579 {
580 	int error;
581 
582 	soassertlocked(so);
583 
584 	if ((so->so_state & SS_ISCONNECTED) == 0)
585 		return (ENOTCONN);
586 	if (so->so_state & SS_ISDISCONNECTING)
587 		return (EALREADY);
588 	error = pru_disconnect(so);
589 	return (error);
590 }
591 
592 int m_getuio(struct mbuf **, int, long, struct uio *);
593 
594 #define	SBLOCKWAIT(f)	(((f) & MSG_DONTWAIT) ? 0 : SBL_WAIT)
595 /*
596  * Send on a socket.
597  * If send must go all at once and message is larger than
598  * send buffering, then hard error.
599  * Lock against other senders.
600  * If must go all at once and not enough room now, then
601  * inform user that this would block and do nothing.
602  * Otherwise, if nonblocking, send as much as possible.
603  * The data to be sent is described by "uio" if nonzero,
604  * otherwise by the mbuf chain "top" (which must be null
605  * if uio is not).  Data provided in mbuf chain must be small
606  * enough to send all at once.
607  *
608  * Returns nonzero on error, timeout or signal; callers
609  * must check for short counts if EINTR/ERESTART are returned.
610  * Data and control buffers are freed on return.
611  */
612 int
613 sosend(struct socket *so, struct mbuf *addr, struct uio *uio, struct mbuf *top,
614     struct mbuf *control, int flags)
615 {
616 	long space, clen = 0;
617 	size_t resid;
618 	int error;
619 	int atomic = sosendallatonce(so) || top;
620 	int dosolock = ((so->so_snd.sb_flags & SB_MTXLOCK) == 0);
621 
622 	if (uio)
623 		resid = uio->uio_resid;
624 	else
625 		resid = top->m_pkthdr.len;
626 	/* MSG_EOR on a SOCK_STREAM socket is invalid. */
627 	if (so->so_type == SOCK_STREAM && (flags & MSG_EOR)) {
628 		m_freem(top);
629 		m_freem(control);
630 		return (EINVAL);
631 	}
632 	if (uio && uio->uio_procp)
633 		uio->uio_procp->p_ru.ru_msgsnd++;
634 	if (control) {
635 		/*
636 		 * In theory clen should be unsigned (since control->m_len is).
637 		 * However, space must be signed, as it might be less than 0
638 		 * if we over-committed, and we must use a signed comparison
639 		 * of space and clen.
640 		 */
641 		clen = control->m_len;
642 		/* reserve extra space for AF_UNIX's internalize */
643 		if (so->so_proto->pr_domain->dom_family == AF_UNIX &&
644 		    clen >= CMSG_ALIGN(sizeof(struct cmsghdr)) &&
645 		    mtod(control, struct cmsghdr *)->cmsg_type == SCM_RIGHTS)
646 			clen = CMSG_SPACE(
647 			    (clen - CMSG_ALIGN(sizeof(struct cmsghdr))) *
648 			    (sizeof(struct fdpass) / sizeof(int)));
649 	}
650 
651 #define	snderr(errno)	{ error = errno; goto release; }
652 
653 restart:
654 	if ((error = sblock(&so->so_snd, SBLOCKWAIT(flags))) != 0)
655 		goto out;
656 	if (dosolock)
657 		solock_shared(so);
658 	sb_mtx_lock(&so->so_snd);
659 	so->so_snd.sb_state |= SS_ISSENDING;
660 	do {
661 		if (so->so_snd.sb_state & SS_CANTSENDMORE)
662 			snderr(EPIPE);
663 		if ((error = READ_ONCE(so->so_error))) {
664 			so->so_error = 0;
665 			snderr(error);
666 		}
667 		if ((so->so_state & SS_ISCONNECTED) == 0) {
668 			if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
669 				if (!(resid == 0 && clen != 0))
670 					snderr(ENOTCONN);
671 			} else if (addr == NULL)
672 				snderr(EDESTADDRREQ);
673 		}
674 		space = sbspace_locked(so, &so->so_snd);
675 		if (flags & MSG_OOB)
676 			space += 1024;
677 		if (so->so_proto->pr_domain->dom_family == AF_UNIX) {
678 			if (atomic && resid > so->so_snd.sb_hiwat)
679 				snderr(EMSGSIZE);
680 		} else {
681 			if (clen > so->so_snd.sb_hiwat ||
682 			    (atomic && resid > so->so_snd.sb_hiwat - clen))
683 				snderr(EMSGSIZE);
684 		}
685 		if (space < clen ||
686 		    (space - clen < resid &&
687 		    (atomic || space < so->so_snd.sb_lowat))) {
688 			if (flags & MSG_DONTWAIT)
689 				snderr(EWOULDBLOCK);
690 			sbunlock(&so->so_snd);
691 			error = sbwait(so, &so->so_snd);
692 			so->so_snd.sb_state &= ~SS_ISSENDING;
693 			sb_mtx_unlock(&so->so_snd);
694 			if (dosolock)
695 				sounlock_shared(so);
696 			if (error)
697 				goto out;
698 			goto restart;
699 		}
700 		space -= clen;
701 		do {
702 			if (uio == NULL) {
703 				/*
704 				 * Data is prepackaged in "top".
705 				 */
706 				resid = 0;
707 				if (flags & MSG_EOR)
708 					top->m_flags |= M_EOR;
709 			} else {
710 				sb_mtx_unlock(&so->so_snd);
711 				if (dosolock)
712 					sounlock_shared(so);
713 				error = m_getuio(&top, atomic, space, uio);
714 				if (dosolock)
715 					solock_shared(so);
716 				sb_mtx_lock(&so->so_snd);
717 				if (error)
718 					goto release;
719 				space -= top->m_pkthdr.len;
720 				resid = uio->uio_resid;
721 				if (flags & MSG_EOR)
722 					top->m_flags |= M_EOR;
723 			}
724 			if (resid == 0)
725 				so->so_snd.sb_state &= ~SS_ISSENDING;
726 			if (top && so->so_options & SO_ZEROIZE)
727 				top->m_flags |= M_ZEROIZE;
728 			sb_mtx_unlock(&so->so_snd);
729 			if (!dosolock)
730 				solock_shared(so);
731 			if (flags & MSG_OOB)
732 				error = pru_sendoob(so, top, addr, control);
733 			else
734 				error = pru_send(so, top, addr, control);
735 			if (!dosolock)
736 				sounlock_shared(so);
737 			sb_mtx_lock(&so->so_snd);
738 			clen = 0;
739 			control = NULL;
740 			top = NULL;
741 			if (error)
742 				goto release;
743 		} while (resid && space > 0);
744 	} while (resid);
745 
746 release:
747 	so->so_snd.sb_state &= ~SS_ISSENDING;
748 	sb_mtx_unlock(&so->so_snd);
749 	if (dosolock)
750 		sounlock_shared(so);
751 	sbunlock(&so->so_snd);
752 out:
753 	m_freem(top);
754 	m_freem(control);
755 	return (error);
756 }
757 
758 int
759 m_getuio(struct mbuf **mp, int atomic, long space, struct uio *uio)
760 {
761 	struct mbuf *m, *top = NULL;
762 	struct mbuf **nextp = &top;
763 	u_long len, mlen;
764 	size_t resid = uio->uio_resid;
765 	int error;
766 
767 	do {
768 		if (top == NULL) {
769 			MGETHDR(m, M_WAIT, MT_DATA);
770 			mlen = MHLEN;
771 		} else {
772 			MGET(m, M_WAIT, MT_DATA);
773 			mlen = MLEN;
774 		}
775 		/* chain mbuf together */
776 		*nextp = m;
777 		nextp = &m->m_next;
778 
779 		resid = ulmin(resid, space);
780 		if (resid >= MINCLSIZE) {
781 			MCLGETL(m, M_NOWAIT, ulmin(resid, MAXMCLBYTES));
782 			if ((m->m_flags & M_EXT) == 0)
783 				MCLGETL(m, M_NOWAIT, MCLBYTES);
784 			if ((m->m_flags & M_EXT) == 0)
785 				goto nopages;
786 			mlen = m->m_ext.ext_size;
787 			len = ulmin(mlen, resid);
788 			/*
789 			 * For datagram protocols, leave room
790 			 * for protocol headers in first mbuf.
791 			 */
792 			if (atomic && m == top && len < mlen - max_hdr)
793 				m->m_data += max_hdr;
794 		} else {
795 nopages:
796 			len = ulmin(mlen, resid);
797 			/*
798 			 * For datagram protocols, leave room
799 			 * for protocol headers in first mbuf.
800 			 */
801 			if (atomic && m == top && len < mlen - max_hdr)
802 				m_align(m, len);
803 		}
804 
805 		error = uiomove(mtod(m, caddr_t), len, uio);
806 		if (error) {
807 			m_freem(top);
808 			return (error);
809 		}
810 
811 		/* adjust counters */
812 		resid = uio->uio_resid;
813 		space -= len;
814 		m->m_len = len;
815 		top->m_pkthdr.len += len;
816 
817 		/* Is there more space and more data? */
818 	} while (space > 0 && resid > 0);
819 
820 	*mp = top;
821 	return 0;
822 }
823 
824 /*
825  * Following replacement or removal of the first mbuf on the first
826  * mbuf chain of a socket buffer, push necessary state changes back
827  * into the socket buffer so that other consumers see the values
828  * consistently.  'nextrecord' is the callers locally stored value of
829  * the original value of sb->sb_mb->m_nextpkt which must be restored
830  * when the lead mbuf changes.  NOTE: 'nextrecord' may be NULL.
831  */
832 void
833 sbsync(struct sockbuf *sb, struct mbuf *nextrecord)
834 {
835 
836 	/*
837 	 * First, update for the new value of nextrecord.  If necessary,
838 	 * make it the first record.
839 	 */
840 	if (sb->sb_mb != NULL)
841 		sb->sb_mb->m_nextpkt = nextrecord;
842 	else
843 		sb->sb_mb = nextrecord;
844 
845 	/*
846 	 * Now update any dependent socket buffer fields to reflect
847 	 * the new state.  This is an inline of SB_EMPTY_FIXUP, with
848 	 * the addition of a second clause that takes care of the
849 	 * case where sb_mb has been updated, but remains the last
850 	 * record.
851 	 */
852 	if (sb->sb_mb == NULL) {
853 		sb->sb_mbtail = NULL;
854 		sb->sb_lastrecord = NULL;
855 	} else if (sb->sb_mb->m_nextpkt == NULL)
856 		sb->sb_lastrecord = sb->sb_mb;
857 }
858 
859 /*
860  * Implement receive operations on a socket.
861  * We depend on the way that records are added to the sockbuf
862  * by sbappend*.  In particular, each record (mbufs linked through m_next)
863  * must begin with an address if the protocol so specifies,
864  * followed by an optional mbuf or mbufs containing ancillary data,
865  * and then zero or more mbufs of data.
866  * In order to avoid blocking network for the entire time here, we release
867  * the solock() while doing the actual copy to user space.
868  * Although the sockbuf is locked, new data may still be appended,
869  * and thus we must maintain consistency of the sockbuf during that time.
870  *
871  * The caller may receive the data as a single mbuf chain by supplying
872  * an mbuf **mp0 for use in returning the chain.  The uio is then used
873  * only for the count in uio_resid.
874  */
875 int
876 soreceive(struct socket *so, struct mbuf **paddr, struct uio *uio,
877     struct mbuf **mp0, struct mbuf **controlp, int *flagsp,
878     socklen_t controllen)
879 {
880 	struct mbuf *m, **mp;
881 	struct mbuf *cm;
882 	u_long len, offset, moff;
883 	int flags, error, error2, type, uio_error = 0;
884 	const struct protosw *pr = so->so_proto;
885 	struct mbuf *nextrecord;
886 	size_t resid, orig_resid = uio->uio_resid;
887 	int dosolock = ((so->so_rcv.sb_flags & SB_MTXLOCK) == 0);
888 
889 	mp = mp0;
890 	if (paddr)
891 		*paddr = NULL;
892 	if (controlp)
893 		*controlp = NULL;
894 	if (flagsp)
895 		flags = *flagsp &~ MSG_EOR;
896 	else
897 		flags = 0;
898 	if (flags & MSG_OOB) {
899 		m = m_get(M_WAIT, MT_DATA);
900 		solock_shared(so);
901 		error = pru_rcvoob(so, m, flags & MSG_PEEK);
902 		sounlock_shared(so);
903 		if (error)
904 			goto bad;
905 		do {
906 			error = uiomove(mtod(m, caddr_t),
907 			    ulmin(uio->uio_resid, m->m_len), uio);
908 			m = m_free(m);
909 		} while (uio->uio_resid && error == 0 && m);
910 bad:
911 		m_freem(m);
912 		return (error);
913 	}
914 	if (mp)
915 		*mp = NULL;
916 
917 restart:
918 	if ((error = sblock(&so->so_rcv, SBLOCKWAIT(flags))) != 0)
919 		return (error);
920 	if (dosolock)
921 		solock_shared(so);
922 	sb_mtx_lock(&so->so_rcv);
923 
924 	m = so->so_rcv.sb_mb;
925 #ifdef SOCKET_SPLICE
926 	if (isspliced(so))
927 		m = NULL;
928 #endif /* SOCKET_SPLICE */
929 	/*
930 	 * If we have less data than requested, block awaiting more
931 	 * (subject to any timeout) if:
932 	 *   1. the current count is less than the low water mark,
933 	 *   2. MSG_WAITALL is set, and it is possible to do the entire
934 	 *	receive operation at once if we block (resid <= hiwat), or
935 	 *   3. MSG_DONTWAIT is not set.
936 	 * If MSG_WAITALL is set but resid is larger than the receive buffer,
937 	 * we have to do the receive in sections, and thus risk returning
938 	 * a short count if a timeout or signal occurs after we start.
939 	 */
940 	if (m == NULL || (((flags & MSG_DONTWAIT) == 0 &&
941 	    so->so_rcv.sb_cc < uio->uio_resid) &&
942 	    (so->so_rcv.sb_cc < so->so_rcv.sb_lowat ||
943 	    ((flags & MSG_WAITALL) && uio->uio_resid <= so->so_rcv.sb_hiwat)) &&
944 	    m->m_nextpkt == NULL && (pr->pr_flags & PR_ATOMIC) == 0)) {
945 #ifdef DIAGNOSTIC
946 		if (m == NULL && so->so_rcv.sb_cc)
947 #ifdef SOCKET_SPLICE
948 		    if (!isspliced(so))
949 #endif /* SOCKET_SPLICE */
950 			panic("receive 1: so %p, so_type %d, sb_cc %lu",
951 			    so, so->so_type, so->so_rcv.sb_cc);
952 #endif
953 		if ((error2 = READ_ONCE(so->so_error))) {
954 			if (m)
955 				goto dontblock;
956 			error = error2;
957 			if ((flags & MSG_PEEK) == 0)
958 				so->so_error = 0;
959 			goto release;
960 		}
961 		if (so->so_rcv.sb_state & SS_CANTRCVMORE) {
962 			if (m)
963 				goto dontblock;
964 			else if (so->so_rcv.sb_cc == 0)
965 				goto release;
966 		}
967 		for (; m; m = m->m_next)
968 			if (m->m_type == MT_OOBDATA  || (m->m_flags & M_EOR)) {
969 				m = so->so_rcv.sb_mb;
970 				goto dontblock;
971 			}
972 		if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
973 		    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
974 			error = ENOTCONN;
975 			goto release;
976 		}
977 		if (uio->uio_resid == 0 && controlp == NULL)
978 			goto release;
979 		if (flags & MSG_DONTWAIT) {
980 			error = EWOULDBLOCK;
981 			goto release;
982 		}
983 		SBLASTRECORDCHK(&so->so_rcv, "soreceive sbwait 1");
984 		SBLASTMBUFCHK(&so->so_rcv, "soreceive sbwait 1");
985 
986 		sbunlock(&so->so_rcv);
987 		error = sbwait(so, &so->so_rcv);
988 		sb_mtx_unlock(&so->so_rcv);
989 		if (dosolock)
990 			sounlock_shared(so);
991 		if (error)
992 			return (error);
993 		goto restart;
994 	}
995 dontblock:
996 	/*
997 	 * On entry here, m points to the first record of the socket buffer.
998 	 * From this point onward, we maintain 'nextrecord' as a cache of the
999 	 * pointer to the next record in the socket buffer.  We must keep the
1000 	 * various socket buffer pointers and local stack versions of the
1001 	 * pointers in sync, pushing out modifications before operations that
1002 	 * may sleep, and re-reading them afterwards.
1003 	 *
1004 	 * Otherwise, we will race with the network stack appending new data
1005 	 * or records onto the socket buffer by using inconsistent/stale
1006 	 * versions of the field, possibly resulting in socket buffer
1007 	 * corruption.
1008 	 */
1009 	if (uio->uio_procp)
1010 		uio->uio_procp->p_ru.ru_msgrcv++;
1011 	KASSERT(m == so->so_rcv.sb_mb);
1012 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 1");
1013 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 1");
1014 	nextrecord = m->m_nextpkt;
1015 	if (pr->pr_flags & PR_ADDR) {
1016 #ifdef DIAGNOSTIC
1017 		if (m->m_type != MT_SONAME)
1018 			panic("receive 1a: so %p, so_type %d, m %p, m_type %d",
1019 			    so, so->so_type, m, m->m_type);
1020 #endif
1021 		orig_resid = 0;
1022 		if (flags & MSG_PEEK) {
1023 			if (paddr)
1024 				*paddr = m_copym(m, 0, m->m_len, M_NOWAIT);
1025 			m = m->m_next;
1026 		} else {
1027 			sbfree(so, &so->so_rcv, m);
1028 			if (paddr) {
1029 				*paddr = m;
1030 				so->so_rcv.sb_mb = m->m_next;
1031 				m->m_next = NULL;
1032 				m = so->so_rcv.sb_mb;
1033 			} else {
1034 				so->so_rcv.sb_mb = m_free(m);
1035 				m = so->so_rcv.sb_mb;
1036 			}
1037 			sbsync(&so->so_rcv, nextrecord);
1038 		}
1039 	}
1040 	while (m && m->m_type == MT_CONTROL && error == 0) {
1041 		int skip = 0;
1042 		if (flags & MSG_PEEK) {
1043 			if (mtod(m, struct cmsghdr *)->cmsg_type ==
1044 			    SCM_RIGHTS) {
1045 				/* don't leak internalized SCM_RIGHTS msgs */
1046 				skip = 1;
1047 			} else if (controlp)
1048 				*controlp = m_copym(m, 0, m->m_len, M_NOWAIT);
1049 			m = m->m_next;
1050 		} else {
1051 			sbfree(so, &so->so_rcv, m);
1052 			so->so_rcv.sb_mb = m->m_next;
1053 			m->m_nextpkt = m->m_next = NULL;
1054 			cm = m;
1055 			m = so->so_rcv.sb_mb;
1056 			sbsync(&so->so_rcv, nextrecord);
1057 			if (controlp) {
1058 				if (pr->pr_domain->dom_externalize) {
1059 					sb_mtx_unlock(&so->so_rcv);
1060 					if (dosolock)
1061 						sounlock_shared(so);
1062 					error =
1063 					    (*pr->pr_domain->dom_externalize)
1064 					    (cm, controllen, flags);
1065 					if (dosolock)
1066 						solock_shared(so);
1067 					sb_mtx_lock(&so->so_rcv);
1068 				}
1069 				*controlp = cm;
1070 			} else {
1071 				/*
1072 				 * Dispose of any SCM_RIGHTS message that went
1073 				 * through the read path rather than recv.
1074 				 */
1075 				if (pr->pr_domain->dom_dispose) {
1076 					sb_mtx_unlock(&so->so_rcv);
1077 					pr->pr_domain->dom_dispose(cm);
1078 					sb_mtx_lock(&so->so_rcv);
1079 				}
1080 				m_free(cm);
1081 			}
1082 		}
1083 		if (m != NULL)
1084 			nextrecord = so->so_rcv.sb_mb->m_nextpkt;
1085 		else
1086 			nextrecord = so->so_rcv.sb_mb;
1087 		if (controlp && !skip)
1088 			controlp = &(*controlp)->m_next;
1089 		orig_resid = 0;
1090 	}
1091 
1092 	/* If m is non-NULL, we have some data to read. */
1093 	if (m) {
1094 		type = m->m_type;
1095 		if (type == MT_OOBDATA)
1096 			flags |= MSG_OOB;
1097 		if (m->m_flags & M_BCAST)
1098 			flags |= MSG_BCAST;
1099 		if (m->m_flags & M_MCAST)
1100 			flags |= MSG_MCAST;
1101 	}
1102 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 2");
1103 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 2");
1104 
1105 	moff = 0;
1106 	offset = 0;
1107 	while (m && uio->uio_resid > 0 && error == 0) {
1108 		if (m->m_type == MT_OOBDATA) {
1109 			if (type != MT_OOBDATA)
1110 				break;
1111 		} else if (type == MT_OOBDATA) {
1112 			break;
1113 		} else if (m->m_type == MT_CONTROL) {
1114 			/*
1115 			 * If there is more than one control message in the
1116 			 * stream, we do a short read.  Next can be received
1117 			 * or disposed by another system call.
1118 			 */
1119 			break;
1120 #ifdef DIAGNOSTIC
1121 		} else if (m->m_type != MT_DATA && m->m_type != MT_HEADER) {
1122 			panic("receive 3: so %p, so_type %d, m %p, m_type %d",
1123 			    so, so->so_type, m, m->m_type);
1124 #endif
1125 		}
1126 		so->so_rcv.sb_state &= ~SS_RCVATMARK;
1127 		len = uio->uio_resid;
1128 		if (so->so_oobmark && len > so->so_oobmark - offset)
1129 			len = so->so_oobmark - offset;
1130 		if (len > m->m_len - moff)
1131 			len = m->m_len - moff;
1132 		/*
1133 		 * If mp is set, just pass back the mbufs.
1134 		 * Otherwise copy them out via the uio, then free.
1135 		 * Sockbuf must be consistent here (points to current mbuf,
1136 		 * it points to next record) when we drop priority;
1137 		 * we must note any additions to the sockbuf when we
1138 		 * block interrupts again.
1139 		 */
1140 		if (mp == NULL && uio_error == 0) {
1141 			SBLASTRECORDCHK(&so->so_rcv, "soreceive uiomove");
1142 			SBLASTMBUFCHK(&so->so_rcv, "soreceive uiomove");
1143 			resid = uio->uio_resid;
1144 			sb_mtx_unlock(&so->so_rcv);
1145 			if (dosolock)
1146 				sounlock_shared(so);
1147 			uio_error = uiomove(mtod(m, caddr_t) + moff, len, uio);
1148 			if (dosolock)
1149 				solock_shared(so);
1150 			sb_mtx_lock(&so->so_rcv);
1151 			if (uio_error)
1152 				uio->uio_resid = resid - len;
1153 		} else
1154 			uio->uio_resid -= len;
1155 		if (len == m->m_len - moff) {
1156 			if (m->m_flags & M_EOR)
1157 				flags |= MSG_EOR;
1158 			if (flags & MSG_PEEK) {
1159 				m = m->m_next;
1160 				moff = 0;
1161 				orig_resid = 0;
1162 			} else {
1163 				nextrecord = m->m_nextpkt;
1164 				sbfree(so, &so->so_rcv, m);
1165 				if (mp) {
1166 					*mp = m;
1167 					mp = &m->m_next;
1168 					so->so_rcv.sb_mb = m = m->m_next;
1169 					*mp = NULL;
1170 				} else {
1171 					so->so_rcv.sb_mb = m_free(m);
1172 					m = so->so_rcv.sb_mb;
1173 				}
1174 				/*
1175 				 * If m != NULL, we also know that
1176 				 * so->so_rcv.sb_mb != NULL.
1177 				 */
1178 				KASSERT(so->so_rcv.sb_mb == m);
1179 				if (m) {
1180 					m->m_nextpkt = nextrecord;
1181 					if (nextrecord == NULL)
1182 						so->so_rcv.sb_lastrecord = m;
1183 				} else {
1184 					so->so_rcv.sb_mb = nextrecord;
1185 					SB_EMPTY_FIXUP(&so->so_rcv);
1186 				}
1187 				SBLASTRECORDCHK(&so->so_rcv, "soreceive 3");
1188 				SBLASTMBUFCHK(&so->so_rcv, "soreceive 3");
1189 			}
1190 		} else {
1191 			if (flags & MSG_PEEK) {
1192 				moff += len;
1193 				orig_resid = 0;
1194 			} else {
1195 				if (mp)
1196 					*mp = m_copym(m, 0, len, M_WAIT);
1197 				m->m_data += len;
1198 				m->m_len -= len;
1199 				so->so_rcv.sb_cc -= len;
1200 				so->so_rcv.sb_datacc -= len;
1201 			}
1202 		}
1203 		if (so->so_oobmark) {
1204 			if ((flags & MSG_PEEK) == 0) {
1205 				so->so_oobmark -= len;
1206 				if (so->so_oobmark == 0) {
1207 					so->so_rcv.sb_state |= SS_RCVATMARK;
1208 					break;
1209 				}
1210 			} else {
1211 				offset += len;
1212 				if (offset == so->so_oobmark)
1213 					break;
1214 			}
1215 		}
1216 		if (flags & MSG_EOR)
1217 			break;
1218 		/*
1219 		 * If the MSG_WAITALL flag is set (for non-atomic socket),
1220 		 * we must not quit until "uio->uio_resid == 0" or an error
1221 		 * termination.  If a signal/timeout occurs, return
1222 		 * with a short count but without error.
1223 		 * Keep sockbuf locked against other readers.
1224 		 */
1225 		while (flags & MSG_WAITALL && m == NULL && uio->uio_resid > 0 &&
1226 		    !sosendallatonce(so) && !nextrecord) {
1227 			if (so->so_rcv.sb_state & SS_CANTRCVMORE ||
1228 			    so->so_error)
1229 				break;
1230 			SBLASTRECORDCHK(&so->so_rcv, "soreceive sbwait 2");
1231 			SBLASTMBUFCHK(&so->so_rcv, "soreceive sbwait 2");
1232 			if (sbwait(so, &so->so_rcv)) {
1233 				sb_mtx_unlock(&so->so_rcv);
1234 				if (dosolock)
1235 					sounlock_shared(so);
1236 				sbunlock(&so->so_rcv);
1237 				return (0);
1238 			}
1239 			if ((m = so->so_rcv.sb_mb) != NULL)
1240 				nextrecord = m->m_nextpkt;
1241 		}
1242 	}
1243 
1244 	if (m && pr->pr_flags & PR_ATOMIC) {
1245 		flags |= MSG_TRUNC;
1246 		if ((flags & MSG_PEEK) == 0)
1247 			(void) sbdroprecord(so, &so->so_rcv);
1248 	}
1249 	if ((flags & MSG_PEEK) == 0) {
1250 		if (m == NULL) {
1251 			/*
1252 			 * First part is an inline SB_EMPTY_FIXUP().  Second
1253 			 * part makes sure sb_lastrecord is up-to-date if
1254 			 * there is still data in the socket buffer.
1255 			 */
1256 			so->so_rcv.sb_mb = nextrecord;
1257 			if (so->so_rcv.sb_mb == NULL) {
1258 				so->so_rcv.sb_mbtail = NULL;
1259 				so->so_rcv.sb_lastrecord = NULL;
1260 			} else if (nextrecord->m_nextpkt == NULL)
1261 				so->so_rcv.sb_lastrecord = nextrecord;
1262 		}
1263 		SBLASTRECORDCHK(&so->so_rcv, "soreceive 4");
1264 		SBLASTMBUFCHK(&so->so_rcv, "soreceive 4");
1265 		if (pr->pr_flags & PR_WANTRCVD) {
1266 			sb_mtx_unlock(&so->so_rcv);
1267 			if (!dosolock)
1268 				solock_shared(so);
1269 			pru_rcvd(so);
1270 			if (!dosolock)
1271 				sounlock_shared(so);
1272 			sb_mtx_lock(&so->so_rcv);
1273 		}
1274 	}
1275 	if (orig_resid == uio->uio_resid && orig_resid &&
1276 	    (flags & MSG_EOR) == 0 &&
1277 	    (so->so_rcv.sb_state & SS_CANTRCVMORE) == 0) {
1278 		sb_mtx_unlock(&so->so_rcv);
1279 		sbunlock(&so->so_rcv);
1280 		goto restart;
1281 	}
1282 
1283 	if (uio_error)
1284 		error = uio_error;
1285 
1286 	if (flagsp)
1287 		*flagsp |= flags;
1288 release:
1289 	sb_mtx_unlock(&so->so_rcv);
1290 	if (dosolock)
1291 		sounlock_shared(so);
1292 	sbunlock(&so->so_rcv);
1293 	return (error);
1294 }
1295 
1296 int
1297 soshutdown(struct socket *so, int how)
1298 {
1299 	int error = 0;
1300 
1301 	switch (how) {
1302 	case SHUT_RD:
1303 		sorflush(so);
1304 		break;
1305 	case SHUT_RDWR:
1306 		sorflush(so);
1307 		/* FALLTHROUGH */
1308 	case SHUT_WR:
1309 		solock(so);
1310 		error = pru_shutdown(so);
1311 		sounlock(so);
1312 		break;
1313 	default:
1314 		error = EINVAL;
1315 		break;
1316 	}
1317 
1318 	return (error);
1319 }
1320 
1321 void
1322 sorflush(struct socket *so)
1323 {
1324 	struct sockbuf *sb = &so->so_rcv;
1325 	struct mbuf *m;
1326 	const struct protosw *pr = so->so_proto;
1327 	int error;
1328 
1329 	error = sblock(sb, SBL_WAIT | SBL_NOINTR);
1330 	/* with SBL_WAIT and SLB_NOINTR sblock() must not fail */
1331 	KASSERT(error == 0);
1332 
1333 	solock_shared(so);
1334 	socantrcvmore(so);
1335 	mtx_enter(&sb->sb_mtx);
1336 	m = sb->sb_mb;
1337 	memset(&sb->sb_startzero, 0,
1338 	     (caddr_t)&sb->sb_endzero - (caddr_t)&sb->sb_startzero);
1339 	sb->sb_timeo_nsecs = INFSLP;
1340 	mtx_leave(&sb->sb_mtx);
1341 	sounlock_shared(so);
1342 	sbunlock(sb);
1343 
1344 	if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose)
1345 		(*pr->pr_domain->dom_dispose)(m);
1346 	m_purge(m);
1347 }
1348 
1349 #ifdef SOCKET_SPLICE
1350 
1351 #define so_splicelen	so_sp->ssp_len
1352 #define so_splicemax	so_sp->ssp_max
1353 #define so_idletv	so_sp->ssp_idletv
1354 #define so_idleto	so_sp->ssp_idleto
1355 #define so_splicetask	so_sp->ssp_task
1356 
1357 int
1358 sosplice(struct socket *so, int fd, off_t max, struct timeval *tv)
1359 {
1360 	struct file	*fp;
1361 	struct socket	*sosp;
1362 	struct taskq	*tq;
1363 	int		 error = 0;
1364 
1365 	if ((so->so_proto->pr_flags & PR_SPLICE) == 0)
1366 		return (EPROTONOSUPPORT);
1367 	if (max && max < 0)
1368 		return (EINVAL);
1369 	if (tv && (tv->tv_sec < 0 || !timerisvalid(tv)))
1370 		return (EINVAL);
1371 
1372 	/* If no fd is given, unsplice by removing existing link. */
1373 	if (fd < 0) {
1374 		if ((error = sblock(&so->so_rcv, SBL_WAIT)) != 0)
1375 			return (error);
1376 		solock(so);
1377 		if (so->so_options & SO_ACCEPTCONN) {
1378 			error = EOPNOTSUPP;
1379 			goto out;
1380 		}
1381 		if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
1382 		    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
1383 			error = ENOTCONN;
1384 			goto out;
1385 		}
1386 
1387 		if (so->so_sp && so->so_sp->ssp_socket)
1388 			sounsplice(so, so->so_sp->ssp_socket, 0);
1389  out:
1390 		sounlock(so);
1391 		sbunlock(&so->so_rcv);
1392 		return (error);
1393 	}
1394 
1395 	if (sosplice_taskq == NULL) {
1396 		rw_enter_write(&sosplice_lock);
1397 		if (sosplice_taskq == NULL) {
1398 			tq = taskq_create("sosplice", 1, IPL_SOFTNET,
1399 			    TASKQ_MPSAFE);
1400 			if (tq == NULL) {
1401 				rw_exit_write(&sosplice_lock);
1402 				return (ENOMEM);
1403 			}
1404 			/* Ensure the taskq is fully visible to other CPUs. */
1405 			membar_producer();
1406 			sosplice_taskq = tq;
1407 		}
1408 		rw_exit_write(&sosplice_lock);
1409 	} else {
1410 		/* Ensure the taskq is fully visible on this CPU. */
1411 		membar_consumer();
1412 	}
1413 
1414 	/* Find sosp, the drain socket where data will be spliced into. */
1415 	if ((error = getsock(curproc, fd, &fp)) != 0)
1416 		return (error);
1417 	sosp = fp->f_data;
1418 
1419 	if (sosp->so_proto->pr_usrreqs->pru_send !=
1420 	    so->so_proto->pr_usrreqs->pru_send) {
1421 		error = EPROTONOSUPPORT;
1422 		goto frele;
1423 	}
1424 
1425 	if ((error = sblock(&so->so_rcv, SBL_WAIT)) != 0)
1426 		goto frele;
1427 	if ((error = sblock(&sosp->so_snd, SBL_WAIT)) != 0) {
1428 		sbunlock(&so->so_rcv);
1429 		goto frele;
1430 	}
1431 	solock(so);
1432 
1433 	if ((so->so_options & SO_ACCEPTCONN) ||
1434 	    (sosp->so_options & SO_ACCEPTCONN)) {
1435 		error = EOPNOTSUPP;
1436 		goto release;
1437 	}
1438 	if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
1439 	    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
1440 		error = ENOTCONN;
1441 		goto release;
1442 	}
1443 	if ((sosp->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0) {
1444 		error = ENOTCONN;
1445 		goto release;
1446 	}
1447 	if (so->so_sp == NULL)
1448 		so->so_sp = pool_get(&sosplice_pool, PR_WAITOK | PR_ZERO);
1449 	if (sosp->so_sp == NULL)
1450 		sosp->so_sp = pool_get(&sosplice_pool, PR_WAITOK | PR_ZERO);
1451 	if (so->so_sp->ssp_socket || sosp->so_sp->ssp_soback) {
1452 		error = EBUSY;
1453 		goto release;
1454 	}
1455 
1456 	so->so_splicelen = 0;
1457 	so->so_splicemax = max;
1458 	if (tv)
1459 		so->so_idletv = *tv;
1460 	else
1461 		timerclear(&so->so_idletv);
1462 	timeout_set_flags(&so->so_idleto, soidle, so,
1463 	    KCLOCK_NONE, TIMEOUT_PROC | TIMEOUT_MPSAFE);
1464 	task_set(&so->so_splicetask, sotask, so);
1465 
1466 	/*
1467 	 * To prevent sorwakeup() calling somove() before this somove()
1468 	 * has finished, the socket buffers are not marked as spliced yet.
1469 	 */
1470 
1471 	/* Splice so and sosp together. */
1472 	mtx_enter(&so->so_rcv.sb_mtx);
1473 	mtx_enter(&sosp->so_snd.sb_mtx);
1474 	so->so_sp->ssp_socket = sosp;
1475 	sosp->so_sp->ssp_soback = so;
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 		sounlock(so);
1481 	if (somove(so, M_WAIT)) {
1482 		mtx_enter(&so->so_rcv.sb_mtx);
1483 		mtx_enter(&sosp->so_snd.sb_mtx);
1484 		so->so_rcv.sb_flags |= SB_SPLICE;
1485 		sosp->so_snd.sb_flags |= SB_SPLICE;
1486 		mtx_leave(&sosp->so_snd.sb_mtx);
1487 		mtx_leave(&so->so_rcv.sb_mtx);
1488 	}
1489 	if ((so->so_proto->pr_flags & PR_WANTRCVD) == 0)
1490 		solock(so);
1491 
1492  release:
1493 	sounlock(so);
1494 	sbunlock(&sosp->so_snd);
1495 	sbunlock(&so->so_rcv);
1496  frele:
1497 	FRELE(fp, curproc);
1498 
1499 	return (error);
1500 }
1501 
1502 void
1503 sounsplice(struct socket *so, struct socket *sosp, int freeing)
1504 {
1505 	sbassertlocked(&so->so_rcv);
1506 	soassertlocked(so);
1507 
1508 	task_del(sosplice_taskq, &so->so_splicetask);
1509 	timeout_del(&so->so_idleto);
1510 
1511 	mtx_enter(&so->so_rcv.sb_mtx);
1512 	mtx_enter(&sosp->so_snd.sb_mtx);
1513 	so->so_rcv.sb_flags &= ~SB_SPLICE;
1514 	sosp->so_snd.sb_flags &= ~SB_SPLICE;
1515 	so->so_sp->ssp_socket = sosp->so_sp->ssp_soback = NULL;
1516 	mtx_leave(&sosp->so_snd.sb_mtx);
1517 	mtx_leave(&so->so_rcv.sb_mtx);
1518 
1519 	/* Do not wakeup a socket that is about to be freed. */
1520 	if ((freeing & SOSP_FREEING_READ) == 0 && soreadable(so))
1521 		sorwakeup(so);
1522 	if ((freeing & SOSP_FREEING_WRITE) == 0 && sowriteable(sosp))
1523 		sowwakeup(sosp);
1524 }
1525 
1526 void
1527 soidle(void *arg)
1528 {
1529 	struct socket *so = arg;
1530 
1531 	sblock(&so->so_rcv, SBL_WAIT | SBL_NOINTR);
1532 	solock(so);
1533 	/*
1534 	 * Depending on socket type, sblock(&so->so_rcv) or solock()
1535 	 * is always held while modifying SB_SPLICE and
1536 	 * so->so_sp->ssp_socket.
1537 	 */
1538 	if (so->so_rcv.sb_flags & SB_SPLICE) {
1539 		so->so_error = ETIMEDOUT;
1540 		sounsplice(so, so->so_sp->ssp_socket, 0);
1541 	}
1542 	sounlock(so);
1543 	sbunlock(&so->so_rcv);
1544 }
1545 
1546 void
1547 sotask(void *arg)
1548 {
1549 	struct socket *so = arg;
1550 	int doyield = 0;
1551 	int sockstream = (so->so_proto->pr_flags & PR_WANTRCVD);
1552 
1553 	/*
1554 	 * sblock() on `so_rcv' protects sockets from being unspliced
1555 	 * for UDP case. TCP sockets still rely on solock().
1556 	 */
1557 
1558 	sblock(&so->so_rcv, SBL_WAIT | SBL_NOINTR);
1559 	if (so->so_rcv.sb_flags & SB_SPLICE) {
1560 		struct socket *sosp = so->so_sp->ssp_socket;
1561 
1562 		if (sockstream) {
1563 			sblock(&sosp->so_snd, SBL_WAIT | SBL_NOINTR);
1564 			solock(so);
1565 			doyield = 1;
1566 		}
1567 
1568 		somove(so, M_DONTWAIT);
1569 
1570 		if (sockstream) {
1571 			sounlock(so);
1572 			sbunlock(&sosp->so_snd);
1573 		}
1574 	}
1575 
1576 	sbunlock(&so->so_rcv);
1577 
1578 	if (doyield) {
1579 		/* Avoid user land starvation. */
1580 		yield();
1581 	}
1582 }
1583 
1584 /*
1585  * Move data from receive buffer of spliced source socket to send
1586  * buffer of drain socket.  Try to move as much as possible in one
1587  * big chunk.  It is a TCP only implementation.
1588  * Return value 0 means splicing has been finished, 1 continue.
1589  */
1590 int
1591 somove(struct socket *so, int wait)
1592 {
1593 	struct socket	*sosp = so->so_sp->ssp_socket;
1594 	struct mbuf	*m, **mp, *nextrecord;
1595 	u_long		 len, off, oobmark;
1596 	long		 space;
1597 	int		 error = 0, maxreached = 0, unsplice = 0;
1598 	unsigned int	 rcvstate;
1599 	int		 sockdgram = ((so->so_proto->pr_flags &
1600 			     PR_WANTRCVD) == 0);
1601 
1602 	if (sockdgram)
1603 		sbassertlocked(&so->so_rcv);
1604 	else {
1605 		sbassertlocked(&sosp->so_snd);
1606 		soassertlocked(so);
1607 	}
1608 
1609 	mtx_enter(&so->so_rcv.sb_mtx);
1610 	mtx_enter(&sosp->so_snd.sb_mtx);
1611 
1612  nextpkt:
1613 	if ((error = READ_ONCE(so->so_error)))
1614 		goto release;
1615 	if (sosp->so_snd.sb_state & SS_CANTSENDMORE) {
1616 		error = EPIPE;
1617 		goto release;
1618 	}
1619 
1620 	error = READ_ONCE(sosp->so_error);
1621 	if (error) {
1622 		if (error != ETIMEDOUT && error != EFBIG && error != ELOOP)
1623 			goto release;
1624 		error = 0;
1625 	}
1626 	if ((sosp->so_state & SS_ISCONNECTED) == 0)
1627 		goto release;
1628 
1629 	/* Calculate how many bytes can be copied now. */
1630 	len = so->so_rcv.sb_datacc;
1631 	if (so->so_splicemax) {
1632 		KASSERT(so->so_splicelen < so->so_splicemax);
1633 		if (so->so_splicemax <= so->so_splicelen + len) {
1634 			len = so->so_splicemax - so->so_splicelen;
1635 			maxreached = 1;
1636 		}
1637 	}
1638 	space = sbspace_locked(sosp, &sosp->so_snd);
1639 	if (so->so_oobmark && so->so_oobmark < len &&
1640 	    so->so_oobmark < space + 1024)
1641 		space += 1024;
1642 	if (space <= 0) {
1643 		maxreached = 0;
1644 		goto release;
1645 	}
1646 	if (space < len) {
1647 		maxreached = 0;
1648 		if (space < sosp->so_snd.sb_lowat)
1649 			goto release;
1650 		len = space;
1651 	}
1652 	sosp->so_snd.sb_state |= SS_ISSENDING;
1653 
1654 	SBLASTRECORDCHK(&so->so_rcv, "somove 1");
1655 	SBLASTMBUFCHK(&so->so_rcv, "somove 1");
1656 	m = so->so_rcv.sb_mb;
1657 	if (m == NULL)
1658 		goto release;
1659 	nextrecord = m->m_nextpkt;
1660 
1661 	/* Drop address and control information not used with splicing. */
1662 	if (so->so_proto->pr_flags & PR_ADDR) {
1663 #ifdef DIAGNOSTIC
1664 		if (m->m_type != MT_SONAME)
1665 			panic("somove soname: so %p, so_type %d, m %p, "
1666 			    "m_type %d", so, so->so_type, m, m->m_type);
1667 #endif
1668 		m = m->m_next;
1669 	}
1670 	while (m && m->m_type == MT_CONTROL)
1671 		m = m->m_next;
1672 	if (m == NULL) {
1673 		sbdroprecord(so, &so->so_rcv);
1674 		if (so->so_proto->pr_flags & PR_WANTRCVD) {
1675 			mtx_leave(&sosp->so_snd.sb_mtx);
1676 			mtx_leave(&so->so_rcv.sb_mtx);
1677 			pru_rcvd(so);
1678 			mtx_enter(&so->so_rcv.sb_mtx);
1679 			mtx_enter(&sosp->so_snd.sb_mtx);
1680 		}
1681 		goto nextpkt;
1682 	}
1683 
1684 	/*
1685 	 * By splicing sockets connected to localhost, userland might create a
1686 	 * loop.  Dissolve splicing with error if loop is detected by counter.
1687 	 *
1688 	 * If we deal with looped broadcast/multicast packet we bail out with
1689 	 * no error to suppress splice termination.
1690 	 */
1691 	if ((m->m_flags & M_PKTHDR) &&
1692 	    ((m->m_pkthdr.ph_loopcnt++ >= M_MAXLOOP) ||
1693 	    ((m->m_flags & M_LOOP) && (m->m_flags & (M_BCAST|M_MCAST))))) {
1694 		error = ELOOP;
1695 		goto release;
1696 	}
1697 
1698 	if (so->so_proto->pr_flags & PR_ATOMIC) {
1699 		if ((m->m_flags & M_PKTHDR) == 0)
1700 			panic("somove !PKTHDR: so %p, so_type %d, m %p, "
1701 			    "m_type %d", so, so->so_type, m, m->m_type);
1702 		if (sosp->so_snd.sb_hiwat < m->m_pkthdr.len) {
1703 			error = EMSGSIZE;
1704 			goto release;
1705 		}
1706 		if (len < m->m_pkthdr.len)
1707 			goto release;
1708 		if (m->m_pkthdr.len < len) {
1709 			maxreached = 0;
1710 			len = m->m_pkthdr.len;
1711 		}
1712 		/*
1713 		 * Throw away the name mbuf after it has been assured
1714 		 * that the whole first record can be processed.
1715 		 */
1716 		m = so->so_rcv.sb_mb;
1717 		sbfree(so, &so->so_rcv, m);
1718 		so->so_rcv.sb_mb = m_free(m);
1719 		sbsync(&so->so_rcv, nextrecord);
1720 	}
1721 	/*
1722 	 * Throw away the control mbufs after it has been assured
1723 	 * that the whole first record can be processed.
1724 	 */
1725 	m = so->so_rcv.sb_mb;
1726 	while (m && m->m_type == MT_CONTROL) {
1727 		sbfree(so, &so->so_rcv, m);
1728 		so->so_rcv.sb_mb = m_free(m);
1729 		m = so->so_rcv.sb_mb;
1730 		sbsync(&so->so_rcv, nextrecord);
1731 	}
1732 
1733 	SBLASTRECORDCHK(&so->so_rcv, "somove 2");
1734 	SBLASTMBUFCHK(&so->so_rcv, "somove 2");
1735 
1736 	/* Take at most len mbufs out of receive buffer. */
1737 	for (off = 0, mp = &m; off <= len && *mp;
1738 	    off += (*mp)->m_len, mp = &(*mp)->m_next) {
1739 		u_long size = len - off;
1740 
1741 #ifdef DIAGNOSTIC
1742 		if ((*mp)->m_type != MT_DATA && (*mp)->m_type != MT_HEADER)
1743 			panic("somove type: so %p, so_type %d, m %p, "
1744 			    "m_type %d", so, so->so_type, *mp, (*mp)->m_type);
1745 #endif
1746 		if ((*mp)->m_len > size) {
1747 			/*
1748 			 * Move only a partial mbuf at maximum splice length or
1749 			 * if the drain buffer is too small for this large mbuf.
1750 			 */
1751 			if (!maxreached && sosp->so_snd.sb_datacc > 0) {
1752 				len -= size;
1753 				break;
1754 			}
1755 			*mp = m_copym(so->so_rcv.sb_mb, 0, size, wait);
1756 			if (*mp == NULL) {
1757 				len -= size;
1758 				break;
1759 			}
1760 			so->so_rcv.sb_mb->m_data += size;
1761 			so->so_rcv.sb_mb->m_len -= size;
1762 			so->so_rcv.sb_cc -= size;
1763 			so->so_rcv.sb_datacc -= size;
1764 		} else {
1765 			*mp = so->so_rcv.sb_mb;
1766 			sbfree(so, &so->so_rcv, *mp);
1767 			so->so_rcv.sb_mb = (*mp)->m_next;
1768 			sbsync(&so->so_rcv, nextrecord);
1769 		}
1770 	}
1771 	*mp = NULL;
1772 
1773 	SBLASTRECORDCHK(&so->so_rcv, "somove 3");
1774 	SBLASTMBUFCHK(&so->so_rcv, "somove 3");
1775 	SBCHECK(so, &so->so_rcv);
1776 	if (m == NULL)
1777 		goto release;
1778 	m->m_nextpkt = NULL;
1779 	if (m->m_flags & M_PKTHDR) {
1780 		m_resethdr(m);
1781 		m->m_pkthdr.len = len;
1782 	}
1783 
1784 	/* Send window update to source peer as receive buffer has changed. */
1785 	if (so->so_proto->pr_flags & PR_WANTRCVD) {
1786 		mtx_leave(&sosp->so_snd.sb_mtx);
1787 		mtx_leave(&so->so_rcv.sb_mtx);
1788 		pru_rcvd(so);
1789 		mtx_enter(&so->so_rcv.sb_mtx);
1790 		mtx_enter(&sosp->so_snd.sb_mtx);
1791 	}
1792 
1793 	/* Receive buffer did shrink by len bytes, adjust oob. */
1794 	rcvstate = so->so_rcv.sb_state;
1795 	so->so_rcv.sb_state &= ~SS_RCVATMARK;
1796 	oobmark = so->so_oobmark;
1797 	so->so_oobmark = oobmark > len ? oobmark - len : 0;
1798 	if (oobmark) {
1799 		if (oobmark == len)
1800 			so->so_rcv.sb_state |= SS_RCVATMARK;
1801 		if (oobmark >= len)
1802 			oobmark = 0;
1803 	}
1804 
1805 	/*
1806 	 * Handle oob data.  If any malloc fails, ignore error.
1807 	 * TCP urgent data is not very reliable anyway.
1808 	 */
1809 	while (((rcvstate & SS_RCVATMARK) || oobmark) &&
1810 	    (so->so_options & SO_OOBINLINE)) {
1811 		struct mbuf *o = NULL;
1812 
1813 		if (rcvstate & SS_RCVATMARK) {
1814 			o = m_get(wait, MT_DATA);
1815 			rcvstate &= ~SS_RCVATMARK;
1816 		} else if (oobmark) {
1817 			o = m_split(m, oobmark, wait);
1818 			if (o) {
1819 				mtx_leave(&sosp->so_snd.sb_mtx);
1820 				mtx_leave(&so->so_rcv.sb_mtx);
1821 				error = pru_send(sosp, m, NULL, NULL);
1822 				mtx_enter(&so->so_rcv.sb_mtx);
1823 				mtx_enter(&sosp->so_snd.sb_mtx);
1824 
1825 				if (error) {
1826 					if (sosp->so_snd.sb_state &
1827 					    SS_CANTSENDMORE)
1828 						error = EPIPE;
1829 					m_freem(o);
1830 					goto release;
1831 				}
1832 				len -= oobmark;
1833 				so->so_splicelen += oobmark;
1834 				m = o;
1835 				o = m_get(wait, MT_DATA);
1836 			}
1837 			oobmark = 0;
1838 		}
1839 		if (o) {
1840 			o->m_len = 1;
1841 			*mtod(o, caddr_t) = *mtod(m, caddr_t);
1842 
1843 			mtx_leave(&sosp->so_snd.sb_mtx);
1844 			mtx_leave(&so->so_rcv.sb_mtx);
1845 			error = pru_sendoob(sosp, o, NULL, NULL);
1846 			mtx_enter(&so->so_rcv.sb_mtx);
1847 			mtx_enter(&sosp->so_snd.sb_mtx);
1848 
1849 			if (error) {
1850 				if (sosp->so_snd.sb_state & SS_CANTSENDMORE)
1851 					error = EPIPE;
1852 				m_freem(m);
1853 				goto release;
1854 			}
1855 			len -= 1;
1856 			so->so_splicelen += 1;
1857 			if (oobmark) {
1858 				oobmark -= 1;
1859 				if (oobmark == 0)
1860 					rcvstate |= SS_RCVATMARK;
1861 			}
1862 			m_adj(m, 1);
1863 		}
1864 	}
1865 
1866 	/* Append all remaining data to drain socket. */
1867 	if (so->so_rcv.sb_cc == 0 || maxreached)
1868 		sosp->so_snd.sb_state &= ~SS_ISSENDING;
1869 
1870 	mtx_leave(&sosp->so_snd.sb_mtx);
1871 	mtx_leave(&so->so_rcv.sb_mtx);
1872 
1873 	if (sockdgram)
1874 		solock_shared(sosp);
1875 	error = pru_send(sosp, m, NULL, NULL);
1876 	if (sockdgram)
1877 		sounlock_shared(sosp);
1878 
1879 	mtx_enter(&so->so_rcv.sb_mtx);
1880 	mtx_enter(&sosp->so_snd.sb_mtx);
1881 
1882 	if (error) {
1883 		if (sosp->so_snd.sb_state & SS_CANTSENDMORE ||
1884 		    sosp->so_pcb == NULL)
1885 			error = EPIPE;
1886 		goto release;
1887 	}
1888 	so->so_splicelen += len;
1889 
1890 	/* Move several packets if possible. */
1891 	if (!maxreached && nextrecord)
1892 		goto nextpkt;
1893 
1894  release:
1895 	sosp->so_snd.sb_state &= ~SS_ISSENDING;
1896 
1897 	if (!error && maxreached && so->so_splicemax == so->so_splicelen)
1898 		error = EFBIG;
1899 	if (error)
1900 		WRITE_ONCE(so->so_error, error);
1901 
1902 	if (((so->so_rcv.sb_state & SS_CANTRCVMORE) &&
1903 	    so->so_rcv.sb_cc == 0) ||
1904 	    (sosp->so_snd.sb_state & SS_CANTSENDMORE) ||
1905 	    maxreached || error)
1906 		unsplice = 1;
1907 
1908 	mtx_leave(&sosp->so_snd.sb_mtx);
1909 	mtx_leave(&so->so_rcv.sb_mtx);
1910 
1911 	if (unsplice) {
1912 		if (sockdgram)
1913 			solock(so);
1914 		sounsplice(so, sosp, 0);
1915 		if (sockdgram)
1916 			sounlock(so);
1917 
1918 		return (0);
1919 	}
1920 	if (timerisset(&so->so_idletv))
1921 		timeout_add_tv(&so->so_idleto, &so->so_idletv);
1922 	return (1);
1923 }
1924 #endif /* SOCKET_SPLICE */
1925 
1926 void
1927 sorwakeup(struct socket *so)
1928 {
1929 	if ((so->so_rcv.sb_flags & SB_MTXLOCK) == 0)
1930 		soassertlocked_readonly(so);
1931 
1932 #ifdef SOCKET_SPLICE
1933 	if (so->so_proto->pr_flags & PR_SPLICE) {
1934 		sb_mtx_lock(&so->so_rcv);
1935 		if (so->so_rcv.sb_flags & SB_SPLICE)
1936 			task_add(sosplice_taskq, &so->so_splicetask);
1937 		if (isspliced(so)) {
1938 			sb_mtx_unlock(&so->so_rcv);
1939 			return;
1940 		}
1941 		sb_mtx_unlock(&so->so_rcv);
1942 	}
1943 #endif
1944 	sowakeup(so, &so->so_rcv);
1945 	if (so->so_upcall)
1946 		(*(so->so_upcall))(so, so->so_upcallarg, M_DONTWAIT);
1947 }
1948 
1949 void
1950 sowwakeup(struct socket *so)
1951 {
1952 	if ((so->so_snd.sb_flags & SB_MTXLOCK) == 0)
1953 		soassertlocked_readonly(so);
1954 
1955 #ifdef SOCKET_SPLICE
1956 	if (so->so_proto->pr_flags & PR_SPLICE) {
1957 		sb_mtx_lock(&so->so_snd);
1958 		if (so->so_snd.sb_flags & SB_SPLICE)
1959 			task_add(sosplice_taskq,
1960 			    &so->so_sp->ssp_soback->so_splicetask);
1961 		if (issplicedback(so)) {
1962 			sb_mtx_unlock(&so->so_snd);
1963 			return;
1964 		}
1965 		sb_mtx_unlock(&so->so_snd);
1966 	}
1967 #endif
1968 	sowakeup(so, &so->so_snd);
1969 }
1970 
1971 int
1972 sosetopt(struct socket *so, int level, int optname, struct mbuf *m)
1973 {
1974 	int error = 0;
1975 
1976 	if (level != SOL_SOCKET) {
1977 		if (so->so_proto->pr_ctloutput) {
1978 			solock(so);
1979 			error = (*so->so_proto->pr_ctloutput)(PRCO_SETOPT, so,
1980 			    level, optname, m);
1981 			sounlock(so);
1982 			return (error);
1983 		}
1984 		error = ENOPROTOOPT;
1985 	} else {
1986 		switch (optname) {
1987 
1988 		case SO_LINGER:
1989 			if (m == NULL || m->m_len != sizeof (struct linger) ||
1990 			    mtod(m, struct linger *)->l_linger < 0 ||
1991 			    mtod(m, struct linger *)->l_linger > SHRT_MAX)
1992 				return (EINVAL);
1993 
1994 			solock(so);
1995 			so->so_linger = mtod(m, struct linger *)->l_linger;
1996 			if (*mtod(m, int *))
1997 				so->so_options |= optname;
1998 			else
1999 				so->so_options &= ~optname;
2000 			sounlock(so);
2001 
2002 			break;
2003 		case SO_BINDANY:
2004 			if ((error = suser(curproc)) != 0)	/* XXX */
2005 				return (error);
2006 			/* FALLTHROUGH */
2007 
2008 		case SO_DEBUG:
2009 		case SO_KEEPALIVE:
2010 		case SO_USELOOPBACK:
2011 		case SO_BROADCAST:
2012 		case SO_REUSEADDR:
2013 		case SO_REUSEPORT:
2014 		case SO_OOBINLINE:
2015 		case SO_TIMESTAMP:
2016 		case SO_ZEROIZE:
2017 			if (m == NULL || m->m_len < sizeof (int))
2018 				return (EINVAL);
2019 
2020 			solock(so);
2021 			if (*mtod(m, int *))
2022 				so->so_options |= optname;
2023 			else
2024 				so->so_options &= ~optname;
2025 			sounlock(so);
2026 
2027 			break;
2028 		case SO_DONTROUTE:
2029 			if (m == NULL || m->m_len < sizeof (int))
2030 				return (EINVAL);
2031 			if (*mtod(m, int *))
2032 				error = EOPNOTSUPP;
2033 			break;
2034 
2035 		case SO_SNDBUF:
2036 		case SO_RCVBUF:
2037 		case SO_SNDLOWAT:
2038 		case SO_RCVLOWAT:
2039 		    {
2040 			struct sockbuf *sb = (optname == SO_SNDBUF ||
2041 			    optname == SO_SNDLOWAT ?
2042 			    &so->so_snd : &so->so_rcv);
2043 			u_long cnt;
2044 
2045 			if (m == NULL || m->m_len < sizeof (int))
2046 				return (EINVAL);
2047 			cnt = *mtod(m, int *);
2048 			if ((long)cnt <= 0)
2049 				cnt = 1;
2050 
2051 			if (((sb->sb_flags & SB_MTXLOCK) == 0))
2052 				solock(so);
2053 			mtx_enter(&sb->sb_mtx);
2054 
2055 			switch (optname) {
2056 			case SO_SNDBUF:
2057 			case SO_RCVBUF:
2058 				if (sb->sb_state &
2059 				    (SS_CANTSENDMORE | SS_CANTRCVMORE)) {
2060 					error = EINVAL;
2061 					break;
2062 				}
2063 				if (sbcheckreserve(cnt, sb->sb_wat) ||
2064 				    sbreserve(so, sb, cnt)) {
2065 					error = ENOBUFS;
2066 					break;
2067 				}
2068 				sb->sb_wat = cnt;
2069 				break;
2070 			case SO_SNDLOWAT:
2071 			case SO_RCVLOWAT:
2072 				sb->sb_lowat = (cnt > sb->sb_hiwat) ?
2073 				    sb->sb_hiwat : cnt;
2074 				break;
2075 			}
2076 
2077 			mtx_leave(&sb->sb_mtx);
2078 			if (((sb->sb_flags & SB_MTXLOCK) == 0))
2079 				sounlock(so);
2080 
2081 			break;
2082 		    }
2083 
2084 		case SO_SNDTIMEO:
2085 		case SO_RCVTIMEO:
2086 		    {
2087 			struct sockbuf *sb = (optname == SO_SNDTIMEO ?
2088 			    &so->so_snd : &so->so_rcv);
2089 			struct timeval tv;
2090 			uint64_t nsecs;
2091 
2092 			if (m == NULL || m->m_len < sizeof (tv))
2093 				return (EINVAL);
2094 			memcpy(&tv, mtod(m, struct timeval *), sizeof tv);
2095 			if (!timerisvalid(&tv))
2096 				return (EINVAL);
2097 			nsecs = TIMEVAL_TO_NSEC(&tv);
2098 			if (nsecs == UINT64_MAX)
2099 				return (EDOM);
2100 			if (nsecs == 0)
2101 				nsecs = INFSLP;
2102 
2103 			mtx_enter(&sb->sb_mtx);
2104 			sb->sb_timeo_nsecs = nsecs;
2105 			mtx_leave(&sb->sb_mtx);
2106 			break;
2107 		    }
2108 
2109 		case SO_RTABLE:
2110 			if (so->so_proto->pr_domain &&
2111 			    so->so_proto->pr_domain->dom_protosw &&
2112 			    so->so_proto->pr_ctloutput) {
2113 				const struct domain *dom =
2114 				    so->so_proto->pr_domain;
2115 
2116 				level = dom->dom_protosw->pr_protocol;
2117 				solock(so);
2118 				error = (*so->so_proto->pr_ctloutput)
2119 				    (PRCO_SETOPT, so, level, optname, m);
2120 				sounlock(so);
2121 			} else
2122 				error = ENOPROTOOPT;
2123 			break;
2124 #ifdef SOCKET_SPLICE
2125 		case SO_SPLICE:
2126 			if (m == NULL) {
2127 				error = sosplice(so, -1, 0, NULL);
2128 			} else if (m->m_len < sizeof(int)) {
2129 				error = EINVAL;
2130 			} else if (m->m_len < sizeof(struct splice)) {
2131 				error = sosplice(so, *mtod(m, int *), 0, NULL);
2132 			} else {
2133 				error = sosplice(so,
2134 				    mtod(m, struct splice *)->sp_fd,
2135 				    mtod(m, struct splice *)->sp_max,
2136 				   &mtod(m, struct splice *)->sp_idle);
2137 			}
2138 			break;
2139 #endif /* SOCKET_SPLICE */
2140 
2141 		default:
2142 			error = ENOPROTOOPT;
2143 			break;
2144 		}
2145 	}
2146 
2147 	return (error);
2148 }
2149 
2150 int
2151 sogetopt(struct socket *so, int level, int optname, struct mbuf *m)
2152 {
2153 	int error = 0;
2154 
2155 	if (level != SOL_SOCKET) {
2156 		if (so->so_proto->pr_ctloutput) {
2157 			m->m_len = 0;
2158 
2159 			solock(so);
2160 			error = (*so->so_proto->pr_ctloutput)(PRCO_GETOPT, so,
2161 			    level, optname, m);
2162 			sounlock(so);
2163 			return (error);
2164 		} else
2165 			return (ENOPROTOOPT);
2166 	} else {
2167 		m->m_len = sizeof (int);
2168 
2169 		switch (optname) {
2170 
2171 		case SO_LINGER:
2172 			m->m_len = sizeof (struct linger);
2173 			solock_shared(so);
2174 			mtod(m, struct linger *)->l_onoff =
2175 				so->so_options & SO_LINGER;
2176 			mtod(m, struct linger *)->l_linger = so->so_linger;
2177 			sounlock_shared(so);
2178 			break;
2179 
2180 		case SO_BINDANY:
2181 		case SO_USELOOPBACK:
2182 		case SO_DEBUG:
2183 		case SO_KEEPALIVE:
2184 		case SO_REUSEADDR:
2185 		case SO_REUSEPORT:
2186 		case SO_BROADCAST:
2187 		case SO_OOBINLINE:
2188 		case SO_ACCEPTCONN:
2189 		case SO_TIMESTAMP:
2190 		case SO_ZEROIZE:
2191 			*mtod(m, int *) = so->so_options & optname;
2192 			break;
2193 
2194 		case SO_DONTROUTE:
2195 			*mtod(m, int *) = 0;
2196 			break;
2197 
2198 		case SO_TYPE:
2199 			*mtod(m, int *) = so->so_type;
2200 			break;
2201 
2202 		case SO_ERROR:
2203 			solock(so);
2204 			*mtod(m, int *) = so->so_error;
2205 			so->so_error = 0;
2206 			sounlock(so);
2207 
2208 			break;
2209 
2210 		case SO_DOMAIN:
2211 			*mtod(m, int *) = so->so_proto->pr_domain->dom_family;
2212 			break;
2213 
2214 		case SO_PROTOCOL:
2215 			*mtod(m, int *) = so->so_proto->pr_protocol;
2216 			break;
2217 
2218 		case SO_SNDBUF:
2219 			*mtod(m, int *) = so->so_snd.sb_hiwat;
2220 			break;
2221 
2222 		case SO_RCVBUF:
2223 			*mtod(m, int *) = so->so_rcv.sb_hiwat;
2224 			break;
2225 
2226 		case SO_SNDLOWAT:
2227 			*mtod(m, int *) = so->so_snd.sb_lowat;
2228 			break;
2229 
2230 		case SO_RCVLOWAT:
2231 			*mtod(m, int *) = so->so_rcv.sb_lowat;
2232 			break;
2233 
2234 		case SO_SNDTIMEO:
2235 		case SO_RCVTIMEO:
2236 		    {
2237 			struct sockbuf *sb = (optname == SO_SNDTIMEO ?
2238 			    &so->so_snd : &so->so_rcv);
2239 			struct timeval tv;
2240 			uint64_t nsecs;
2241 
2242 			mtx_enter(&sb->sb_mtx);
2243 			nsecs = sb->sb_timeo_nsecs;
2244 			mtx_leave(&sb->sb_mtx);
2245 
2246 			m->m_len = sizeof(struct timeval);
2247 			memset(&tv, 0, sizeof(tv));
2248 			if (nsecs != INFSLP)
2249 				NSEC_TO_TIMEVAL(nsecs, &tv);
2250 			memcpy(mtod(m, struct timeval *), &tv, sizeof tv);
2251 			break;
2252 		    }
2253 
2254 		case SO_RTABLE:
2255 			if (so->so_proto->pr_domain &&
2256 			    so->so_proto->pr_domain->dom_protosw &&
2257 			    so->so_proto->pr_ctloutput) {
2258 				const struct domain *dom =
2259 				    so->so_proto->pr_domain;
2260 
2261 				level = dom->dom_protosw->pr_protocol;
2262 				solock(so);
2263 				error = (*so->so_proto->pr_ctloutput)
2264 				    (PRCO_GETOPT, so, level, optname, m);
2265 				sounlock(so);
2266 				if (error)
2267 					return (error);
2268 				break;
2269 			}
2270 			return (ENOPROTOOPT);
2271 
2272 #ifdef SOCKET_SPLICE
2273 		case SO_SPLICE:
2274 		    {
2275 			off_t len;
2276 
2277 			m->m_len = sizeof(off_t);
2278 			solock_shared(so);
2279 			len = so->so_sp ? so->so_sp->ssp_len : 0;
2280 			sounlock_shared(so);
2281 			memcpy(mtod(m, off_t *), &len, sizeof(off_t));
2282 			break;
2283 		    }
2284 #endif /* SOCKET_SPLICE */
2285 
2286 		case SO_PEERCRED:
2287 			if (so->so_proto->pr_protocol == AF_UNIX) {
2288 				struct unpcb *unp = sotounpcb(so);
2289 
2290 				solock(so);
2291 				if (unp->unp_flags & UNP_FEIDS) {
2292 					m->m_len = sizeof(unp->unp_connid);
2293 					memcpy(mtod(m, caddr_t),
2294 					    &(unp->unp_connid), m->m_len);
2295 					sounlock(so);
2296 					break;
2297 				}
2298 				sounlock(so);
2299 
2300 				return (ENOTCONN);
2301 			}
2302 			return (EOPNOTSUPP);
2303 
2304 		default:
2305 			return (ENOPROTOOPT);
2306 		}
2307 		return (0);
2308 	}
2309 }
2310 
2311 void
2312 sohasoutofband(struct socket *so)
2313 {
2314 	pgsigio(&so->so_sigio, SIGURG, 0);
2315 	knote(&so->so_rcv.sb_klist, 0);
2316 }
2317 
2318 void
2319 sofilt_lock(struct socket *so, struct sockbuf *sb)
2320 {
2321 	switch (so->so_proto->pr_domain->dom_family) {
2322 	case PF_INET:
2323 	case PF_INET6:
2324 		NET_LOCK_SHARED();
2325 		break;
2326 	default:
2327 		rw_enter_write(&so->so_lock);
2328 		break;
2329 	}
2330 
2331 	mtx_enter(&sb->sb_mtx);
2332 }
2333 
2334 void
2335 sofilt_unlock(struct socket *so, struct sockbuf *sb)
2336 {
2337 	mtx_leave(&sb->sb_mtx);
2338 
2339 	switch (so->so_proto->pr_domain->dom_family) {
2340 	case PF_INET:
2341 	case PF_INET6:
2342 		NET_UNLOCK_SHARED();
2343 		break;
2344 	default:
2345 		rw_exit_write(&so->so_lock);
2346 		break;
2347 	}
2348 }
2349 
2350 int
2351 soo_kqfilter(struct file *fp, struct knote *kn)
2352 {
2353 	struct socket *so = kn->kn_fp->f_data;
2354 	struct sockbuf *sb;
2355 
2356 	switch (kn->kn_filter) {
2357 	case EVFILT_READ:
2358 		kn->kn_fop = &soread_filtops;
2359 		sb = &so->so_rcv;
2360 		break;
2361 	case EVFILT_WRITE:
2362 		kn->kn_fop = &sowrite_filtops;
2363 		sb = &so->so_snd;
2364 		break;
2365 	case EVFILT_EXCEPT:
2366 		kn->kn_fop = &soexcept_filtops;
2367 		sb = &so->so_rcv;
2368 		break;
2369 	default:
2370 		return (EINVAL);
2371 	}
2372 
2373 	klist_insert(&sb->sb_klist, kn);
2374 
2375 	return (0);
2376 }
2377 
2378 void
2379 filt_sordetach(struct knote *kn)
2380 {
2381 	struct socket *so = kn->kn_fp->f_data;
2382 
2383 	klist_remove(&so->so_rcv.sb_klist, kn);
2384 }
2385 
2386 int
2387 filt_soread(struct knote *kn, long hint)
2388 {
2389 	struct socket *so = kn->kn_fp->f_data;
2390 	u_int state = READ_ONCE(so->so_state);
2391 	u_int error = READ_ONCE(so->so_error);
2392 	int rv = 0;
2393 
2394 	MUTEX_ASSERT_LOCKED(&so->so_rcv.sb_mtx);
2395 	if ((so->so_rcv.sb_flags & SB_MTXLOCK) == 0)
2396 		soassertlocked_readonly(so);
2397 
2398 	if (so->so_options & SO_ACCEPTCONN) {
2399 		short qlen = READ_ONCE(so->so_qlen);
2400 
2401 		if (so->so_rcv.sb_flags & SB_MTXLOCK)
2402 			soassertlocked_readonly(so);
2403 
2404 		kn->kn_data = qlen;
2405 		rv = (kn->kn_data != 0);
2406 
2407 		if (kn->kn_flags & (__EV_POLL | __EV_SELECT)) {
2408 			if (state & SS_ISDISCONNECTED) {
2409 				kn->kn_flags |= __EV_HUP;
2410 				rv = 1;
2411 			} else {
2412 				rv = qlen || soreadable(so);
2413 			}
2414 		}
2415 
2416 		return rv;
2417 	}
2418 
2419 	kn->kn_data = so->so_rcv.sb_cc;
2420 #ifdef SOCKET_SPLICE
2421 	if (isspliced(so)) {
2422 		rv = 0;
2423 	} else
2424 #endif /* SOCKET_SPLICE */
2425 	if (so->so_rcv.sb_state & SS_CANTRCVMORE) {
2426 		kn->kn_flags |= EV_EOF;
2427 		if (kn->kn_flags & __EV_POLL) {
2428 			if (state & SS_ISDISCONNECTED)
2429 				kn->kn_flags |= __EV_HUP;
2430 		}
2431 		kn->kn_fflags = error;
2432 		rv = 1;
2433 	} else if (error) {
2434 		rv = 1;
2435 	} else if (kn->kn_sfflags & NOTE_LOWAT) {
2436 		rv = (kn->kn_data >= kn->kn_sdata);
2437 	} else {
2438 		rv = (kn->kn_data >= so->so_rcv.sb_lowat);
2439 	}
2440 
2441 	return rv;
2442 }
2443 
2444 void
2445 filt_sowdetach(struct knote *kn)
2446 {
2447 	struct socket *so = kn->kn_fp->f_data;
2448 
2449 	klist_remove(&so->so_snd.sb_klist, kn);
2450 }
2451 
2452 int
2453 filt_sowrite(struct knote *kn, long hint)
2454 {
2455 	struct socket *so = kn->kn_fp->f_data;
2456 	u_int state = READ_ONCE(so->so_state);
2457 	u_int error = READ_ONCE(so->so_error);
2458 	int rv;
2459 
2460 	MUTEX_ASSERT_LOCKED(&so->so_snd.sb_mtx);
2461 	if ((so->so_snd.sb_flags & SB_MTXLOCK) == 0)
2462 		soassertlocked_readonly(so);
2463 
2464 	kn->kn_data = sbspace_locked(so, &so->so_snd);
2465 	if (so->so_snd.sb_state & SS_CANTSENDMORE) {
2466 		kn->kn_flags |= EV_EOF;
2467 		if (kn->kn_flags & __EV_POLL) {
2468 			if (state & SS_ISDISCONNECTED)
2469 				kn->kn_flags |= __EV_HUP;
2470 		}
2471 		kn->kn_fflags = error;
2472 		rv = 1;
2473 	} else if (error) {
2474 		rv = 1;
2475 	} else if (((state & SS_ISCONNECTED) == 0) &&
2476 	    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
2477 		rv = 0;
2478 	} else if (kn->kn_sfflags & NOTE_LOWAT) {
2479 		rv = (kn->kn_data >= kn->kn_sdata);
2480 	} else {
2481 		rv = (kn->kn_data >= so->so_snd.sb_lowat);
2482 	}
2483 
2484 	return (rv);
2485 }
2486 
2487 int
2488 filt_soexcept(struct knote *kn, long hint)
2489 {
2490 	struct socket *so = kn->kn_fp->f_data;
2491 	int rv = 0;
2492 
2493 	MUTEX_ASSERT_LOCKED(&so->so_rcv.sb_mtx);
2494 	if ((so->so_rcv.sb_flags & SB_MTXLOCK) == 0)
2495 		soassertlocked_readonly(so);
2496 
2497 #ifdef SOCKET_SPLICE
2498 	if (isspliced(so)) {
2499 		rv = 0;
2500 	} else
2501 #endif /* SOCKET_SPLICE */
2502 	if (kn->kn_sfflags & NOTE_OOB) {
2503 		if (so->so_oobmark || (so->so_rcv.sb_state & SS_RCVATMARK)) {
2504 			kn->kn_fflags |= NOTE_OOB;
2505 			kn->kn_data -= so->so_oobmark;
2506 			rv = 1;
2507 		}
2508 	}
2509 
2510 	if (kn->kn_flags & __EV_POLL) {
2511 		u_int state = READ_ONCE(so->so_state);
2512 
2513 		if (state & SS_ISDISCONNECTED) {
2514 			kn->kn_flags |= __EV_HUP;
2515 			rv = 1;
2516 		}
2517 	}
2518 
2519 	return rv;
2520 }
2521 
2522 int
2523 filt_sowmodify(struct kevent *kev, struct knote *kn)
2524 {
2525 	struct socket *so = kn->kn_fp->f_data;
2526 	int rv;
2527 
2528 	sofilt_lock(so, &so->so_snd);
2529 	rv = knote_modify(kev, kn);
2530 	sofilt_unlock(so, &so->so_snd);
2531 
2532 	return (rv);
2533 }
2534 
2535 int
2536 filt_sowprocess(struct knote *kn, struct kevent *kev)
2537 {
2538 	struct socket *so = kn->kn_fp->f_data;
2539 	int rv;
2540 
2541 	sofilt_lock(so, &so->so_snd);
2542 	rv = knote_process(kn, kev);
2543 	sofilt_unlock(so, &so->so_snd);
2544 
2545 	return (rv);
2546 }
2547 
2548 int
2549 filt_sormodify(struct kevent *kev, struct knote *kn)
2550 {
2551 	struct socket *so = kn->kn_fp->f_data;
2552 	int rv;
2553 
2554 	sofilt_lock(so, &so->so_rcv);
2555 	rv = knote_modify(kev, kn);
2556 	sofilt_unlock(so, &so->so_rcv);
2557 
2558 	return (rv);
2559 }
2560 
2561 int
2562 filt_sorprocess(struct knote *kn, struct kevent *kev)
2563 {
2564 	struct socket *so = kn->kn_fp->f_data;
2565 	int rv;
2566 
2567 	sofilt_lock(so, &so->so_rcv);
2568 	rv = knote_process(kn, kev);
2569 	sofilt_unlock(so, &so->so_rcv);
2570 
2571 	return (rv);
2572 }
2573 
2574 #ifdef DDB
2575 void
2576 sobuf_print(struct sockbuf *,
2577     int (*)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))));
2578 
2579 void
2580 sobuf_print(struct sockbuf *sb,
2581     int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))))
2582 {
2583 	(*pr)("\tsb_cc: %lu\n", sb->sb_cc);
2584 	(*pr)("\tsb_datacc: %lu\n", sb->sb_datacc);
2585 	(*pr)("\tsb_hiwat: %lu\n", sb->sb_hiwat);
2586 	(*pr)("\tsb_wat: %lu\n", sb->sb_wat);
2587 	(*pr)("\tsb_mbcnt: %lu\n", sb->sb_mbcnt);
2588 	(*pr)("\tsb_mbmax: %lu\n", sb->sb_mbmax);
2589 	(*pr)("\tsb_lowat: %ld\n", sb->sb_lowat);
2590 	(*pr)("\tsb_mb: %p\n", sb->sb_mb);
2591 	(*pr)("\tsb_mbtail: %p\n", sb->sb_mbtail);
2592 	(*pr)("\tsb_lastrecord: %p\n", sb->sb_lastrecord);
2593 	(*pr)("\tsb_flags: %04x\n", sb->sb_flags);
2594 	(*pr)("\tsb_state: %04x\n", sb->sb_state);
2595 	(*pr)("\tsb_timeo_nsecs: %llu\n", sb->sb_timeo_nsecs);
2596 }
2597 
2598 void
2599 so_print(void *v,
2600     int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))))
2601 {
2602 	struct socket *so = v;
2603 
2604 	(*pr)("socket %p\n", so);
2605 	(*pr)("so_type: %i\n", so->so_type);
2606 	(*pr)("so_options: 0x%04x\n", so->so_options); /* %b */
2607 	(*pr)("so_linger: %i\n", so->so_linger);
2608 	(*pr)("so_state: 0x%04x\n", so->so_state);
2609 	(*pr)("so_pcb: %p\n", so->so_pcb);
2610 	(*pr)("so_proto: %p\n", so->so_proto);
2611 	(*pr)("so_sigio: %p\n", so->so_sigio.sir_sigio);
2612 
2613 	(*pr)("so_head: %p\n", so->so_head);
2614 	(*pr)("so_onq: %p\n", so->so_onq);
2615 	(*pr)("so_q0: @%p first: %p\n", &so->so_q0, TAILQ_FIRST(&so->so_q0));
2616 	(*pr)("so_q: @%p first: %p\n", &so->so_q, TAILQ_FIRST(&so->so_q));
2617 	(*pr)("so_eq: next: %p\n", TAILQ_NEXT(so, so_qe));
2618 	(*pr)("so_q0len: %i\n", so->so_q0len);
2619 	(*pr)("so_qlen: %i\n", so->so_qlen);
2620 	(*pr)("so_qlimit: %i\n", so->so_qlimit);
2621 	(*pr)("so_timeo: %i\n", so->so_timeo);
2622 	(*pr)("so_obmark: %lu\n", so->so_oobmark);
2623 
2624 	(*pr)("so_sp: %p\n", so->so_sp);
2625 	if (so->so_sp != NULL) {
2626 		(*pr)("\tssp_socket: %p\n", so->so_sp->ssp_socket);
2627 		(*pr)("\tssp_soback: %p\n", so->so_sp->ssp_soback);
2628 		(*pr)("\tssp_len: %lld\n",
2629 		    (unsigned long long)so->so_sp->ssp_len);
2630 		(*pr)("\tssp_max: %lld\n",
2631 		    (unsigned long long)so->so_sp->ssp_max);
2632 		(*pr)("\tssp_idletv: %lld %ld\n", so->so_sp->ssp_idletv.tv_sec,
2633 		    so->so_sp->ssp_idletv.tv_usec);
2634 		(*pr)("\tssp_idleto: %spending (@%i)\n",
2635 		    timeout_pending(&so->so_sp->ssp_idleto) ? "" : "not ",
2636 		    so->so_sp->ssp_idleto.to_time);
2637 	}
2638 
2639 	(*pr)("so_rcv:\n");
2640 	sobuf_print(&so->so_rcv, pr);
2641 	(*pr)("so_snd:\n");
2642 	sobuf_print(&so->so_snd, pr);
2643 
2644 	(*pr)("so_upcall: %p so_upcallarg: %p\n",
2645 	    so->so_upcall, so->so_upcallarg);
2646 
2647 	(*pr)("so_euid: %d so_ruid: %d\n", so->so_euid, so->so_ruid);
2648 	(*pr)("so_egid: %d so_rgid: %d\n", so->so_egid, so->so_rgid);
2649 	(*pr)("so_cpid: %d\n", so->so_cpid);
2650 }
2651 #endif
2652