xref: /dragonfly/sys/kern/uipc_socket.c (revision 43778e29)
1 /*
2  * Copyright (c) 2004 Jeffrey M. Hsu.  All rights reserved.
3  * Copyright (c) 2004 The DragonFly Project.  All rights reserved.
4  *
5  * This code is derived from software contributed to The DragonFly Project
6  * by Jeffrey M. Hsu.
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 DragonFly Project nor the names of its
17  *    contributors may be used to endorse or promote products derived
18  *    from this software without specific, prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
24  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
30  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * Copyright (c) 1982, 1986, 1988, 1990, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. Neither the name of the University nor the names of its contributors
47  *    may be used to endorse or promote products derived from this software
48  *    without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60  * SUCH DAMAGE.
61  *
62  *	@(#)uipc_socket.c	8.3 (Berkeley) 4/15/94
63  * $FreeBSD: src/sys/kern/uipc_socket.c,v 1.68.2.24 2003/11/11 17:18:18 silby Exp $
64  */
65 
66 #include "opt_inet.h"
67 
68 #include <sys/param.h>
69 #include <sys/systm.h>
70 #include <sys/fcntl.h>
71 #include <sys/malloc.h>
72 #include <sys/mbuf.h>
73 #include <sys/domain.h>
74 #include <sys/file.h>			/* for struct knote */
75 #include <sys/kernel.h>
76 #include <sys/event.h>
77 #include <sys/proc.h>
78 #include <sys/protosw.h>
79 #include <sys/socket.h>
80 #include <sys/socketvar.h>
81 #include <sys/socketops.h>
82 #include <sys/resourcevar.h>
83 #include <sys/signalvar.h>
84 #include <sys/sysctl.h>
85 #include <sys/uio.h>
86 #include <sys/jail.h>
87 #include <vm/vm_zone.h>
88 #include <vm/pmap.h>
89 #include <net/netmsg2.h>
90 #include <net/netisr2.h>
91 
92 #include <sys/socketvar2.h>
93 #include <sys/spinlock2.h>
94 
95 #include <machine/limits.h>
96 
97 #ifdef INET
98 extern int tcp_sosend_agglim;
99 extern int tcp_sosend_async;
100 extern int tcp_sosend_jcluster;
101 extern int udp_sosend_async;
102 extern int udp_sosend_prepend;
103 
104 static int	 do_setopt_accept_filter(struct socket *so, struct sockopt *sopt);
105 #endif /* INET */
106 
107 static void 	filt_sordetach(struct knote *kn);
108 static int 	filt_soread(struct knote *kn, long hint);
109 static void 	filt_sowdetach(struct knote *kn);
110 static int	filt_sowrite(struct knote *kn, long hint);
111 static int	filt_solisten(struct knote *kn, long hint);
112 
113 static int	soclose_sync(struct socket *so, int fflag);
114 static void	soclose_fast(struct socket *so);
115 
116 static struct filterops solisten_filtops =
117 	{ FILTEROP_ISFD|FILTEROP_MPSAFE, NULL, filt_sordetach, filt_solisten };
118 static struct filterops soread_filtops =
119 	{ FILTEROP_ISFD|FILTEROP_MPSAFE, NULL, filt_sordetach, filt_soread };
120 static struct filterops sowrite_filtops =
121 	{ FILTEROP_ISFD|FILTEROP_MPSAFE, NULL, filt_sowdetach, filt_sowrite };
122 static struct filterops soexcept_filtops =
123 	{ FILTEROP_ISFD|FILTEROP_MPSAFE, NULL, filt_sordetach, filt_soread };
124 
125 MALLOC_DEFINE(M_SOCKET, "socket", "socket struct");
126 MALLOC_DEFINE(M_SONAME, "soname", "socket name");
127 MALLOC_DEFINE(M_PCB, "pcb", "protocol control block");
128 
129 
130 static int somaxconn = SOMAXCONN;
131 SYSCTL_INT(_kern_ipc, KIPC_SOMAXCONN, somaxconn, CTLFLAG_RW,
132     &somaxconn, 0, "Maximum pending socket connection queue size");
133 
134 static int use_soclose_fast = 1;
135 SYSCTL_INT(_kern_ipc, OID_AUTO, soclose_fast, CTLFLAG_RW,
136     &use_soclose_fast, 0, "Fast socket close");
137 
138 int use_soaccept_pred_fast = 1;
139 SYSCTL_INT(_kern_ipc, OID_AUTO, soaccept_pred_fast, CTLFLAG_RW,
140     &use_soaccept_pred_fast, 0, "Fast socket accept predication");
141 
142 int use_sendfile_async = 1;
143 SYSCTL_INT(_kern_ipc, OID_AUTO, sendfile_async, CTLFLAG_RW,
144     &use_sendfile_async, 0, "sendfile uses asynchronized pru_send");
145 
146 int use_soconnect_async = 1;
147 SYSCTL_INT(_kern_ipc, OID_AUTO, soconnect_async, CTLFLAG_RW,
148     &use_soconnect_async, 0, "soconnect uses asynchronized pru_connect");
149 
150 static int use_socreate_fast = 1;
151 SYSCTL_INT(_kern_ipc, OID_AUTO, socreate_fast, CTLFLAG_RW,
152     &use_socreate_fast, 0, "Fast socket creation");
153 
154 static int soavailconn = 32;
155 SYSCTL_INT(_kern_ipc, OID_AUTO, soavailconn, CTLFLAG_RW,
156     &soavailconn, 0, "Maximum available socket connection queue size");
157 
158 /*
159  * Socket operation routines.
160  * These routines are called by the routines in
161  * sys_socket.c or from a system process, and
162  * implement the semantics of socket operations by
163  * switching out to the protocol specific routines.
164  */
165 
166 /*
167  * Get a socket structure, and initialize it.
168  * Note that it would probably be better to allocate socket
169  * and PCB at the same time, but I'm not convinced that all
170  * the protocols can be easily modified to do this.
171  */
172 struct socket *
173 soalloc(int waitok, struct protosw *pr)
174 {
175 	globaldata_t gd = mycpu;
176 	struct socket *so;
177 	unsigned waitmask;
178 
179 	waitmask = waitok ? M_WAITOK : M_NOWAIT;
180 	so = kmalloc(sizeof(struct socket), M_SOCKET, M_ZERO|waitmask);
181 	if (so) {
182 		/* XXX race condition for reentrant kernel */
183 		so->so_proto = pr;
184 		TAILQ_INIT(&so->so_aiojobq);
185 		TAILQ_INIT(&so->so_rcv.ssb_mlist);
186 		TAILQ_INIT(&so->so_snd.ssb_mlist);
187 		lwkt_token_init(&so->so_rcv.ssb_token, "rcvtok");
188 		lwkt_token_init(&so->so_snd.ssb_token, "sndtok");
189 		spin_init(&so->so_rcvd_spin, "soalloc");
190 		netmsg_init(&so->so_rcvd_msg.base, so, &netisr_adone_rport,
191 		    MSGF_DROPABLE | MSGF_PRIORITY,
192 		    so->so_proto->pr_usrreqs->pru_rcvd);
193 		so->so_rcvd_msg.nm_pru_flags |= PRUR_ASYNC;
194 		so->so_state = SS_NOFDREF;
195 		so->so_refs = 1;
196 		so->so_inum = gd->gd_anoninum++ * ncpus + gd->gd_cpuid + 2;
197 	}
198 	return so;
199 }
200 
201 int
202 socreate(int dom, struct socket **aso, int type,
203 	int proto, struct thread *td)
204 {
205 	struct proc *p = td->td_proc;
206 	struct protosw *prp;
207 	struct socket *so;
208 	struct pru_attach_info ai;
209 	struct prison *pr = p->p_ucred->cr_prison;
210 	int error;
211 
212 	if (proto)
213 		prp = pffindproto(dom, proto, type);
214 	else
215 		prp = pffindtype(dom, type);
216 
217 	if (prp == NULL || prp->pr_usrreqs->pru_attach == 0)
218 		return (EPROTONOSUPPORT);
219 
220 	if (pr && PRISON_CAP_ISSET(pr->pr_caps, PRISON_CAP_NET_UNIXIPROUTE) &&
221 	    prp->pr_domain->dom_family != PF_LOCAL &&
222 	    prp->pr_domain->dom_family != PF_INET &&
223 	    prp->pr_domain->dom_family != PF_INET6 &&
224 	    prp->pr_domain->dom_family != PF_ROUTE) {
225 		return (EPROTONOSUPPORT);
226 	}
227 
228 	if (prp->pr_type != type)
229 		return (EPROTOTYPE);
230 	so = soalloc(p != NULL, prp);
231 	if (so == NULL)
232 		return (ENOBUFS);
233 
234 	/*
235 	 * Callers of socreate() presumably will connect up a descriptor
236 	 * and call soclose() if they cannot.  This represents our so_refs
237 	 * (which should be 1) from soalloc().
238 	 */
239 	soclrstate(so, SS_NOFDREF);
240 
241 	/*
242 	 * Set a default port for protocol processing.  No action will occur
243 	 * on the socket on this port until an inpcb is attached to it and
244 	 * is able to match incoming packets, or until the socket becomes
245 	 * available to userland.
246 	 *
247 	 * We normally default the socket to the protocol thread on cpu 0,
248 	 * if protocol does not provide its own method to initialize the
249 	 * default port.
250 	 *
251 	 * If PR_SYNC_PORT is set (unix domain sockets) there is no protocol
252 	 * thread and all pr_*()/pru_*() calls are executed synchronously.
253 	 */
254 	if (prp->pr_flags & PR_SYNC_PORT)
255 		so->so_port = &netisr_sync_port;
256 	else if (prp->pr_initport != NULL)
257 		so->so_port = prp->pr_initport();
258 	else
259 		so->so_port = netisr_cpuport(0);
260 
261 	TAILQ_INIT(&so->so_incomp);
262 	TAILQ_INIT(&so->so_comp);
263 	so->so_type = type;
264 	so->so_cred = crhold(p->p_ucred);
265 	ai.sb_rlimit = &p->p_rlimit[RLIMIT_SBSIZE];
266 	ai.p_ucred = p->p_ucred;
267 	ai.fd_rdir = p->p_fd->fd_rdir;
268 
269 	/*
270 	 * Auto-sizing of socket buffers is managed by the protocols and
271 	 * the appropriate flags must be set in the pru_attach function.
272 	 */
273 	if (use_socreate_fast && prp->pr_usrreqs->pru_preattach)
274 		error = so_pru_attach_fast(so, proto, &ai);
275 	else
276 		error = so_pru_attach(so, proto, &ai);
277 	if (error) {
278 		sosetstate(so, SS_NOFDREF);
279 		sofree(so);	/* from soalloc */
280 		return error;
281 	}
282 
283 	/*
284 	 * NOTE: Returns referenced socket.
285 	 */
286 	*aso = so;
287 	return (0);
288 }
289 
290 int
291 sobind(struct socket *so, struct sockaddr *nam, struct thread *td)
292 {
293 	int error;
294 
295 	error = so_pru_bind(so, nam, td);
296 	return (error);
297 }
298 
299 static void
300 sodealloc(struct socket *so)
301 {
302 	KKASSERT((so->so_state & (SS_INCOMP | SS_COMP)) == 0);
303 
304 #ifdef INVARIANTS
305 	if (so->so_options & SO_ACCEPTCONN) {
306 		KASSERT(TAILQ_EMPTY(&so->so_comp), ("so_comp is not empty"));
307 		KASSERT(TAILQ_EMPTY(&so->so_incomp),
308 		    ("so_incomp is not empty"));
309 	}
310 #endif
311 
312 	if (so->so_rcv.ssb_hiwat)
313 		(void)chgsbsize(so->so_cred->cr_uidinfo,
314 		    &so->so_rcv.ssb_hiwat, 0, RLIM_INFINITY);
315 	if (so->so_snd.ssb_hiwat)
316 		(void)chgsbsize(so->so_cred->cr_uidinfo,
317 		    &so->so_snd.ssb_hiwat, 0, RLIM_INFINITY);
318 #ifdef INET
319 	/* remove accept filter if present */
320 	if (so->so_accf != NULL)
321 		do_setopt_accept_filter(so, NULL);
322 #endif /* INET */
323 	crfree(so->so_cred);
324 	if (so->so_faddr != NULL)
325 		kfree(so->so_faddr, M_SONAME);
326 	kfree(so, M_SOCKET);
327 }
328 
329 int
330 solisten(struct socket *so, int backlog, struct thread *td)
331 {
332 	if (so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING))
333 		return (EINVAL);
334 
335 	lwkt_gettoken(&so->so_rcv.ssb_token);
336 	if (TAILQ_EMPTY(&so->so_comp))
337 		so->so_options |= SO_ACCEPTCONN;
338 	lwkt_reltoken(&so->so_rcv.ssb_token);
339 	if (backlog < 0 || backlog > somaxconn)
340 		backlog = somaxconn;
341 	so->so_qlimit = backlog;
342 	return so_pru_listen(so, td);
343 }
344 
345 static void
346 soqflush(struct socket *so)
347 {
348 	lwkt_getpooltoken(so);
349 	if (so->so_options & SO_ACCEPTCONN) {
350 		struct socket *sp;
351 
352 		while ((sp = TAILQ_FIRST(&so->so_incomp)) != NULL) {
353 			KKASSERT((sp->so_state & (SS_INCOMP | SS_COMP)) ==
354 			    SS_INCOMP);
355 			TAILQ_REMOVE(&so->so_incomp, sp, so_list);
356 			so->so_incqlen--;
357 			soclrstate(sp, SS_INCOMP);
358 			soabort_async(sp, TRUE);
359 		}
360 		while ((sp = TAILQ_FIRST(&so->so_comp)) != NULL) {
361 			KKASSERT((sp->so_state & (SS_INCOMP | SS_COMP)) ==
362 			    SS_COMP);
363 			TAILQ_REMOVE(&so->so_comp, sp, so_list);
364 			so->so_qlen--;
365 			soclrstate(sp, SS_COMP);
366 			soabort_async(sp, TRUE);
367 		}
368 	}
369 	lwkt_relpooltoken(so);
370 }
371 
372 /*
373  * Destroy a disconnected socket.  This routine is a NOP if entities
374  * still have a reference on the socket:
375  *
376  *	so_pcb -	The protocol stack still has a reference
377  *	SS_NOFDREF -	There is no longer a file pointer reference
378  */
379 void
380 sofree(struct socket *so)
381 {
382 	struct socket *head;
383 
384 	/*
385 	 * This is a bit hackish at the moment.  We need to interlock
386 	 * any accept queue we are on before we potentially lose the
387 	 * last reference to avoid races against a re-reference from
388 	 * someone operating on the queue.
389 	 */
390 	while ((head = so->so_head) != NULL) {
391 		lwkt_getpooltoken(head);
392 		if (so->so_head == head)
393 			break;
394 		lwkt_relpooltoken(head);
395 	}
396 
397 	/*
398 	 * Arbitrage the last free.
399 	 */
400 	KKASSERT(so->so_refs > 0);
401 	if (atomic_fetchadd_int(&so->so_refs, -1) != 1) {
402 		if (head)
403 			lwkt_relpooltoken(head);
404 		return;
405 	}
406 
407 	KKASSERT(so->so_pcb == NULL && (so->so_state & SS_NOFDREF));
408 	KKASSERT((so->so_state & SS_ASSERTINPROG) == 0);
409 
410 	if (head != NULL) {
411 		/*
412 		 * We're done, remove ourselves from the accept queue we are
413 		 * on, if we are on one.
414 		 */
415 		if (so->so_state & SS_INCOMP) {
416 			KKASSERT((so->so_state & (SS_INCOMP | SS_COMP)) ==
417 			    SS_INCOMP);
418 			TAILQ_REMOVE(&head->so_incomp, so, so_list);
419 			head->so_incqlen--;
420 		} else if (so->so_state & SS_COMP) {
421 			/*
422 			 * We must not decommission a socket that's
423 			 * on the accept(2) queue.  If we do, then
424 			 * accept(2) may hang after select(2) indicated
425 			 * that the listening socket was ready.
426 			 */
427 			KKASSERT((so->so_state & (SS_INCOMP | SS_COMP)) ==
428 			    SS_COMP);
429 			lwkt_relpooltoken(head);
430 			return;
431 		} else {
432 			panic("sofree: not queued");
433 		}
434 		soclrstate(so, SS_INCOMP);
435 		so->so_head = NULL;
436 		lwkt_relpooltoken(head);
437 	} else {
438 		/* Flush accept queues, if we are accepting. */
439 		soqflush(so);
440 	}
441 	ssb_release(&so->so_snd, so);
442 	sorflush(so);
443 	sodealloc(so);
444 }
445 
446 /*
447  * Close a socket on last file table reference removal.
448  * Initiate disconnect if connected.
449  * Free socket when disconnect complete.
450  */
451 int
452 soclose(struct socket *so, int fflag)
453 {
454 	int error;
455 
456 	funsetown(&so->so_sigio);
457 	sosetstate(so, SS_ISCLOSING);
458 	if (!use_soclose_fast ||
459 	    (so->so_proto->pr_flags & PR_SYNC_PORT) ||
460 	    ((so->so_state & SS_ISCONNECTED) &&
461 	     (so->so_options & SO_LINGER) &&
462 	     so->so_linger != 0)) {
463 		error = soclose_sync(so, fflag);
464 	} else {
465 		soclose_fast(so);
466 		error = 0;
467 	}
468 	return error;
469 }
470 
471 void
472 sodiscard(struct socket *so)
473 {
474 	if (so->so_state & SS_NOFDREF)
475 		panic("soclose: NOFDREF");
476 	sosetstate(so, SS_NOFDREF);	/* take ref */
477 }
478 
479 /*
480  * Append the completed queue of head to head_inh (inherting listen socket).
481  */
482 void
483 soinherit(struct socket *head, struct socket *head_inh)
484 {
485 	boolean_t do_wakeup = FALSE;
486 
487 	KASSERT(head->so_options & SO_ACCEPTCONN,
488 	    ("head does not accept connection"));
489 	KASSERT(head_inh->so_options & SO_ACCEPTCONN,
490 	    ("head_inh does not accept connection"));
491 
492 	lwkt_getpooltoken(head);
493 	lwkt_getpooltoken(head_inh);
494 
495 	if (head->so_qlen > 0)
496 		do_wakeup = TRUE;
497 
498 	while (!TAILQ_EMPTY(&head->so_comp)) {
499 		struct ucred *old_cr;
500 		struct socket *sp;
501 
502 		sp = TAILQ_FIRST(&head->so_comp);
503 		KKASSERT((sp->so_state & (SS_INCOMP | SS_COMP)) == SS_COMP);
504 
505 		/*
506 		 * Remove this socket from the current listen socket
507 		 * completed queue.
508 		 */
509 		TAILQ_REMOVE(&head->so_comp, sp, so_list);
510 		head->so_qlen--;
511 
512 		/* Save the old ucred for later free. */
513 		old_cr = sp->so_cred;
514 
515 		/*
516 		 * Install this socket to the inheriting listen socket
517 		 * completed queue.
518 		 */
519 		sp->so_cred = crhold(head_inh->so_cred); /* non-blocking */
520 		sp->so_head = head_inh;
521 
522 		TAILQ_INSERT_TAIL(&head_inh->so_comp, sp, so_list);
523 		head_inh->so_qlen++;
524 
525 		/*
526 		 * NOTE:
527 		 * crfree() may block and release the tokens temporarily.
528 		 * However, we are fine here, since the transition is done.
529 		 */
530 		crfree(old_cr);
531 	}
532 
533 	lwkt_relpooltoken(head_inh);
534 	lwkt_relpooltoken(head);
535 
536 	if (do_wakeup) {
537 		/*
538 		 * "New" connections have arrived
539 		 */
540 		sorwakeup(head_inh);
541 		wakeup(&head_inh->so_timeo);
542 	}
543 }
544 
545 static int
546 soclose_sync(struct socket *so, int fflag)
547 {
548 	int error = 0;
549 
550 	if ((so->so_proto->pr_flags & PR_SYNC_PORT) == 0)
551 		so_pru_sync(so); /* unpend async prus */
552 
553 	if (so->so_pcb == NULL)
554 		goto discard;
555 
556 	if (so->so_state & SS_ISCONNECTED) {
557 		if ((so->so_state & SS_ISDISCONNECTING) == 0) {
558 			error = sodisconnect(so);
559 			if (error)
560 				goto drop;
561 		}
562 		if (so->so_options & SO_LINGER) {
563 			if ((so->so_state & SS_ISDISCONNECTING) &&
564 			    (fflag & FNONBLOCK))
565 				goto drop;
566 			while (so->so_state & SS_ISCONNECTED) {
567 				error = tsleep(&so->so_timeo, PCATCH,
568 					       "soclos", so->so_linger * hz);
569 				if (error)
570 					break;
571 			}
572 		}
573 	}
574 drop:
575 	if (so->so_pcb) {
576 		int error2;
577 
578 		error2 = so_pru_detach(so);
579 		if (error2 == EJUSTRETURN) {
580 			/*
581 			 * Protocol will call sodiscard()
582 			 * and sofree() for us.
583 			 */
584 			return error;
585 		}
586 		if (error == 0)
587 			error = error2;
588 	}
589 discard:
590 	sodiscard(so);
591 	sofree(so);		/* dispose of ref */
592 
593 	return (error);
594 }
595 
596 static void
597 soclose_fast_handler(netmsg_t msg)
598 {
599 	struct socket *so = msg->base.nm_so;
600 
601 	if (so->so_pcb == NULL)
602 		goto discard;
603 
604 	if ((so->so_state & SS_ISCONNECTED) &&
605 	    (so->so_state & SS_ISDISCONNECTING) == 0)
606 		so_pru_disconnect_direct(so);
607 
608 	if (so->so_pcb) {
609 		int error;
610 
611 		error = so_pru_detach_direct(so);
612 		if (error == EJUSTRETURN) {
613 			/*
614 			 * Protocol will call sodiscard()
615 			 * and sofree() for us.
616 			 */
617 			return;
618 		}
619 	}
620 discard:
621 	sodiscard(so);
622 	sofree(so);
623 }
624 
625 static void
626 soclose_fast(struct socket *so)
627 {
628 	struct netmsg_base *base = &so->so_clomsg;
629 
630 	netmsg_init(base, so, &netisr_apanic_rport, 0,
631 	    soclose_fast_handler);
632 	if (so->so_port == netisr_curport())
633 		lwkt_sendmsg_oncpu(so->so_port, &base->lmsg);
634 	else
635 		lwkt_sendmsg(so->so_port, &base->lmsg);
636 }
637 
638 /*
639  * Abort and destroy a socket.  Only one abort can be in progress
640  * at any given moment.
641  */
642 void
643 soabort_async(struct socket *so, boolean_t clr_head)
644 {
645 	/*
646 	 * Keep a reference before clearing the so_head
647 	 * to avoid racing socket close in netisr.
648 	 */
649 	soreference(so);
650 	if (clr_head)
651 		so->so_head = NULL;
652 	so_pru_abort_async(so);
653 }
654 
655 void
656 soabort_direct(struct socket *so)
657 {
658 	soreference(so);
659 	so_pru_abort_direct(so);
660 }
661 
662 /*
663  * so is passed in ref'd, which becomes owned by
664  * the cleared SS_NOFDREF flag.
665  */
666 void
667 soaccept_generic(struct socket *so)
668 {
669 	if ((so->so_state & SS_NOFDREF) == 0)
670 		panic("soaccept: !NOFDREF");
671 	soclrstate(so, SS_NOFDREF);	/* owned by lack of SS_NOFDREF */
672 }
673 
674 int
675 soaccept(struct socket *so, struct sockaddr **nam)
676 {
677 	int error;
678 
679 	soaccept_generic(so);
680 	error = so_pru_accept(so, nam);
681 	return (error);
682 }
683 
684 int
685 soconnect(struct socket *so, struct sockaddr *nam, struct thread *td,
686     boolean_t sync)
687 {
688 	int error;
689 
690 	if (so->so_options & SO_ACCEPTCONN)
691 		return (EOPNOTSUPP);
692 	/*
693 	 * If protocol is connection-based, can only connect once.
694 	 * Otherwise, if connected, try to disconnect first.
695 	 * This allows user to disconnect by connecting to, e.g.,
696 	 * a null address.
697 	 */
698 	if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
699 	    ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
700 	    (error = sodisconnect(so)))) {
701 		error = EISCONN;
702 	} else {
703 		/*
704 		 * Prevent accumulated error from previous connection
705 		 * from biting us.
706 		 */
707 		so->so_error = 0;
708 		if (!sync && so->so_proto->pr_usrreqs->pru_preconnect)
709 			error = so_pru_connect_async(so, nam, td);
710 		else
711 			error = so_pru_connect(so, nam, td);
712 	}
713 	return (error);
714 }
715 
716 int
717 soconnect2(struct socket *so1, struct socket *so2, struct ucred *cred)
718 {
719 	int error;
720 
721 	error = so_pru_connect2(so1, so2, cred);
722 	return (error);
723 }
724 
725 int
726 sodisconnect(struct socket *so)
727 {
728 	int error;
729 
730 	if ((so->so_state & SS_ISCONNECTED) == 0) {
731 		error = ENOTCONN;
732 		goto bad;
733 	}
734 	if (so->so_state & SS_ISDISCONNECTING) {
735 		error = EALREADY;
736 		goto bad;
737 	}
738 	error = so_pru_disconnect(so);
739 bad:
740 	return (error);
741 }
742 
743 #define	SBLOCKWAIT(f)	(((f) & MSG_DONTWAIT) ? M_NOWAIT : M_WAITOK)
744 /*
745  * Send on a socket.
746  * If send must go all at once and message is larger than
747  * send buffering, then hard error.
748  * Lock against other senders.
749  * If must go all at once and not enough room now, then
750  * inform user that this would block and do nothing.
751  * Otherwise, if nonblocking, send as much as possible.
752  * The data to be sent is described by "uio" if nonzero,
753  * otherwise by the mbuf chain "top" (which must be null
754  * if uio is not).  Data provided in mbuf chain must be small
755  * enough to send all at once.
756  *
757  * Returns nonzero on error, timeout or signal; callers
758  * must check for short counts if EINTR/ERESTART are returned.
759  * Data and control buffers are freed on return.
760  */
761 int
762 sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
763 	struct mbuf *top, struct mbuf *control, int flags,
764 	struct thread *td)
765 {
766 	struct mbuf **mp;
767 	struct mbuf *m;
768 	size_t resid;
769 	int space, len;
770 	int clen = 0, error, dontroute, mlen;
771 	int atomic = sosendallatonce(so) || top;
772 	int pru_flags;
773 
774 	if (uio) {
775 		resid = uio->uio_resid;
776 	} else {
777 		resid = (size_t)top->m_pkthdr.len;
778 #ifdef INVARIANTS
779 		len = 0;
780 		for (m = top; m; m = m->m_next)
781 			len += m->m_len;
782 		KKASSERT(top->m_pkthdr.len == len);
783 #endif
784 	}
785 
786 	/*
787 	 * WARNING!  resid is unsigned, space and len are signed.  space
788 	 * 	     can wind up negative if the sockbuf is overcommitted.
789 	 *
790 	 * Also check to make sure that MSG_EOR isn't used on SOCK_STREAM
791 	 * type sockets since that's an error.
792 	 */
793 	if (so->so_type == SOCK_STREAM && (flags & MSG_EOR)) {
794 		error = EINVAL;
795 		goto out;
796 	}
797 
798 	dontroute =
799 	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
800 	    (so->so_proto->pr_flags & PR_ATOMIC);
801 	if (td->td_lwp != NULL)
802 		td->td_lwp->lwp_ru.ru_msgsnd++;
803 	if (control)
804 		clen = control->m_len;
805 #define	gotoerr(errcode)	{ error = errcode; goto release; }
806 
807 restart:
808 	error = ssb_lock(&so->so_snd, SBLOCKWAIT(flags));
809 	if (error)
810 		goto out;
811 
812 	do {
813 		if (so->so_state & SS_CANTSENDMORE)
814 			gotoerr(EPIPE);
815 		if (so->so_error) {
816 			error = so->so_error;
817 			so->so_error = 0;
818 			goto release;
819 		}
820 		if ((so->so_state & SS_ISCONNECTED) == 0) {
821 			/*
822 			 * `sendto' and `sendmsg' is allowed on a connection-
823 			 * based socket if it supports implied connect.
824 			 * Return ENOTCONN if not connected and no address is
825 			 * supplied.
826 			 */
827 			if ((so->so_proto->pr_flags & PR_CONNREQUIRED) &&
828 			    (so->so_proto->pr_flags & PR_IMPLOPCL) == 0) {
829 				if ((so->so_state & SS_ISCONFIRMING) == 0 &&
830 				    !(resid == 0 && clen != 0))
831 					gotoerr(ENOTCONN);
832 			} else if (addr == NULL)
833 			    gotoerr(so->so_proto->pr_flags & PR_CONNREQUIRED ?
834 				   ENOTCONN : EDESTADDRREQ);
835 		}
836 		if ((atomic && resid > so->so_snd.ssb_hiwat) ||
837 		    clen > so->so_snd.ssb_hiwat) {
838 			gotoerr(EMSGSIZE);
839 		}
840 		space = ssb_space(&so->so_snd);
841 		if (flags & MSG_OOB)
842 			space += 1024;
843 		if ((space < 0 || (size_t)space < resid + clen) && uio &&
844 		    (atomic || space < so->so_snd.ssb_lowat || space < clen)) {
845 			if (flags & (MSG_FNONBLOCKING|MSG_DONTWAIT))
846 				gotoerr(EWOULDBLOCK);
847 			ssb_unlock(&so->so_snd);
848 			error = ssb_wait(&so->so_snd);
849 			if (error)
850 				goto out;
851 			goto restart;
852 		}
853 		mp = &top;
854 		space -= clen;
855 		do {
856 		    if (uio == NULL) {
857 			/*
858 			 * Data is prepackaged in "top".
859 			 */
860 			resid = 0;
861 			if (flags & MSG_EOR)
862 				top->m_flags |= M_EOR;
863 		    } else do {
864 			if (resid > INT_MAX)
865 				resid = INT_MAX;
866 			m = m_getl((int)resid, M_WAITOK, MT_DATA,
867 				   top == NULL ? M_PKTHDR : 0, &mlen);
868 			if (top == NULL) {
869 				m->m_pkthdr.len = 0;
870 				m->m_pkthdr.rcvif = NULL;
871 			}
872 			len = imin((int)szmin(mlen, resid), space);
873 			if (resid < MINCLSIZE) {
874 				/*
875 				 * For datagram protocols, leave room
876 				 * for protocol headers in first mbuf.
877 				 */
878 				if (atomic && top == NULL && len < mlen)
879 					MH_ALIGN(m, len);
880 			}
881 			space -= len;
882 			error = uiomove(mtod(m, caddr_t), (size_t)len, uio);
883 			resid = uio->uio_resid;
884 			m->m_len = len;
885 			*mp = m;
886 			top->m_pkthdr.len += len;
887 			if (error)
888 				goto release;
889 			mp = &m->m_next;
890 			if (resid == 0) {
891 				if (flags & MSG_EOR)
892 					top->m_flags |= M_EOR;
893 				break;
894 			}
895 		    } while (space > 0 && atomic);
896 		    if (dontroute)
897 			    so->so_options |= SO_DONTROUTE;
898 		    if (flags & MSG_OOB) {
899 		    	    pru_flags = PRUS_OOB;
900 		    } else if ((flags & MSG_EOF) &&
901 		    	       (so->so_proto->pr_flags & PR_IMPLOPCL) &&
902 			       (resid == 0)) {
903 			    /*
904 			     * If the user set MSG_EOF, the protocol
905 			     * understands this flag and nothing left to
906 			     * send then use PRU_SEND_EOF instead of PRU_SEND.
907 			     */
908 		    	    pru_flags = PRUS_EOF;
909 		    } else if (resid > 0 && space > 0) {
910 			    /* If there is more to send, set PRUS_MORETOCOME */
911 		    	    pru_flags = PRUS_MORETOCOME;
912 		    } else {
913 		    	    pru_flags = 0;
914 		    }
915 		    /*
916 		     * XXX all the SS_CANTSENDMORE checks previously
917 		     * done could be out of date.  We could have recieved
918 		     * a reset packet in an interrupt or maybe we slept
919 		     * while doing page faults in uiomove() etc. We could
920 		     * probably recheck again inside the splnet() protection
921 		     * here, but there are probably other places that this
922 		     * also happens.  We must rethink this.
923 		     */
924 		    error = so_pru_send(so, pru_flags, top, addr, control, td);
925 		    if (dontroute)
926 			    so->so_options &= ~SO_DONTROUTE;
927 		    clen = 0;
928 		    control = NULL;
929 		    top = NULL;
930 		    mp = &top;
931 		    if (error)
932 			    goto release;
933 		} while (resid && space > 0);
934 	} while (resid);
935 
936 release:
937 	ssb_unlock(&so->so_snd);
938 out:
939 	if (top)
940 		m_freem(top);
941 	if (control)
942 		m_freem(control);
943 	return (error);
944 }
945 
946 #ifdef INET
947 /*
948  * A specialization of sosend() for UDP based on protocol-specific knowledge:
949  *   so->so_proto->pr_flags has the PR_ATOMIC field set.  This means that
950  *	sosendallatonce() returns true,
951  *	the "atomic" variable is true,
952  *	and sosendudp() blocks until space is available for the entire send.
953  *   so->so_proto->pr_flags does not have the PR_CONNREQUIRED or
954  *	PR_IMPLOPCL flags set.
955  *   UDP has no out-of-band data.
956  *   UDP has no control data.
957  *   UDP does not support MSG_EOR.
958  */
959 int
960 sosendudp(struct socket *so, struct sockaddr *addr, struct uio *uio,
961 	  struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
962 {
963 	size_t resid;
964 	int error, pru_flags = 0;
965 	int space;
966 
967 	if (td->td_lwp != NULL)
968 		td->td_lwp->lwp_ru.ru_msgsnd++;
969 
970 	KASSERT((uio && !top) || (top && !uio), ("bad arguments to sosendudp"));
971 	resid = uio ? uio->uio_resid : (size_t)top->m_pkthdr.len;
972 
973 restart:
974 	error = ssb_lock(&so->so_snd, SBLOCKWAIT(flags));
975 	if (error)
976 		goto out;
977 
978 	if (so->so_state & SS_CANTSENDMORE)
979 		gotoerr(EPIPE);
980 	if (so->so_error) {
981 		error = so->so_error;
982 		so->so_error = 0;
983 		goto release;
984 	}
985 	if (!(so->so_state & SS_ISCONNECTED) && addr == NULL)
986 		gotoerr(EDESTADDRREQ);
987 	if (resid > so->so_snd.ssb_hiwat)
988 		gotoerr(EMSGSIZE);
989 	space = ssb_space(&so->so_snd);
990 	if (uio && (space < 0 || (size_t)space < resid)) {
991 		if (flags & (MSG_FNONBLOCKING|MSG_DONTWAIT))
992 			gotoerr(EWOULDBLOCK);
993 		ssb_unlock(&so->so_snd);
994 		error = ssb_wait(&so->so_snd);
995 		if (error)
996 			goto out;
997 		goto restart;
998 	}
999 
1000 	if (uio) {
1001 		int hdrlen = max_hdr;
1002 
1003 		/*
1004 		 * We try to optimize out the additional mbuf
1005 		 * allocations in M_PREPEND() on output path, e.g.
1006 		 * - udp_output(), when it tries to prepend protocol
1007 		 *   headers.
1008 		 * - Link layer output function, when it tries to
1009 		 *   prepend link layer header.
1010 		 *
1011 		 * This probably will not benefit any data that will
1012 		 * be fragmented, so this optimization is only performed
1013 		 * when the size of data and max size of protocol+link
1014 		 * headers fit into one mbuf cluster.
1015 		 */
1016 		if (uio->uio_resid > MCLBYTES - hdrlen ||
1017 		    !udp_sosend_prepend) {
1018 			top = m_uiomove(uio);
1019 			if (top == NULL)
1020 				goto release;
1021 		} else {
1022 			int nsize;
1023 
1024 			top = m_getl(uio->uio_resid + hdrlen, M_WAITOK,
1025 			    MT_DATA, M_PKTHDR, &nsize);
1026 			KASSERT(nsize >= uio->uio_resid + hdrlen,
1027 			    ("sosendudp invalid nsize %d, "
1028 			     "resid %zu, hdrlen %d",
1029 			     nsize, uio->uio_resid, hdrlen));
1030 
1031 			top->m_len = uio->uio_resid;
1032 			top->m_pkthdr.len = uio->uio_resid;
1033 			top->m_data += hdrlen;
1034 
1035 			error = uiomove(mtod(top, caddr_t), top->m_len, uio);
1036 			if (error)
1037 				goto out;
1038 		}
1039 	}
1040 
1041 	if (flags & MSG_DONTROUTE)
1042 		pru_flags |= PRUS_DONTROUTE;
1043 
1044 	if (udp_sosend_async && (flags & MSG_SYNC) == 0) {
1045 		so_pru_send_async(so, pru_flags, top, addr, control, td);
1046 		error = 0;
1047 	} else {
1048 		error = so_pru_send(so, pru_flags, top, addr, control, td);
1049 	}
1050 
1051 	/* sent or freed in lower layer */
1052 	control = NULL;
1053 	top = NULL;
1054 
1055 release:
1056 	ssb_unlock(&so->so_snd);
1057 out:
1058 	if (top)
1059 		m_freem(top);
1060 	if (control)
1061 		m_freem(control);
1062 	return (error);
1063 }
1064 
1065 int
1066 sosendtcp(struct socket *so, struct sockaddr *addr, struct uio *uio,
1067 	struct mbuf *top, struct mbuf *control, int flags,
1068 	struct thread *td)
1069 {
1070 	struct mbuf **mp;
1071 	struct mbuf *m;
1072 	size_t resid;
1073 	int space, len;
1074 	int error, mlen;
1075 	int allatonce;
1076 	int pru_flags;
1077 
1078 	if (uio) {
1079 		KKASSERT(top == NULL);
1080 		allatonce = 0;
1081 		resid = uio->uio_resid;
1082 	} else {
1083 		allatonce = 1;
1084 		resid = (size_t)top->m_pkthdr.len;
1085 #ifdef INVARIANTS
1086 		len = 0;
1087 		for (m = top; m; m = m->m_next)
1088 			len += m->m_len;
1089 		KKASSERT(top->m_pkthdr.len == len);
1090 #endif
1091 	}
1092 
1093 	/*
1094 	 * WARNING!  resid is unsigned, space and len are signed.  space
1095 	 * 	     can wind up negative if the sockbuf is overcommitted.
1096 	 *
1097 	 * Also check to make sure that MSG_EOR isn't used on TCP
1098 	 */
1099 	if (flags & MSG_EOR) {
1100 		error = EINVAL;
1101 		goto out;
1102 	}
1103 
1104 	if (control) {
1105 		/* TCP doesn't do control messages (rights, creds, etc) */
1106 		if (control->m_len) {
1107 			error = EINVAL;
1108 			goto out;
1109 		}
1110 		m_freem(control);	/* empty control, just free it */
1111 		control = NULL;
1112 	}
1113 
1114 	if (td->td_lwp != NULL)
1115 		td->td_lwp->lwp_ru.ru_msgsnd++;
1116 
1117 #define	gotoerr(errcode)	{ error = errcode; goto release; }
1118 
1119 restart:
1120 	error = ssb_lock(&so->so_snd, SBLOCKWAIT(flags));
1121 	if (error)
1122 		goto out;
1123 
1124 	do {
1125 		if (so->so_state & SS_CANTSENDMORE)
1126 			gotoerr(EPIPE);
1127 		if (so->so_error) {
1128 			error = so->so_error;
1129 			so->so_error = 0;
1130 			goto release;
1131 		}
1132 		if ((so->so_state & SS_ISCONNECTED) == 0 &&
1133 		    (so->so_state & SS_ISCONFIRMING) == 0)
1134 			gotoerr(ENOTCONN);
1135 		if (allatonce && resid > so->so_snd.ssb_hiwat)
1136 			gotoerr(EMSGSIZE);
1137 
1138 		space = ssb_space_prealloc(&so->so_snd);
1139 		if (flags & MSG_OOB)
1140 			space += 1024;
1141 		if ((space < 0 || (size_t)space < resid) && !allatonce &&
1142 		    space < so->so_snd.ssb_lowat) {
1143 			if (flags & (MSG_FNONBLOCKING|MSG_DONTWAIT))
1144 				gotoerr(EWOULDBLOCK);
1145 			ssb_unlock(&so->so_snd);
1146 			error = ssb_wait(&so->so_snd);
1147 			if (error)
1148 				goto out;
1149 			goto restart;
1150 		}
1151 		mp = &top;
1152 		do {
1153 		    int cnt = 0, async = 0;
1154 
1155 		    if (uio == NULL) {
1156 			/*
1157 			 * Data is prepackaged in "top".
1158 			 */
1159 			resid = 0;
1160 		    } else do {
1161 			if (resid > INT_MAX)
1162 				resid = INT_MAX;
1163 			if (tcp_sosend_jcluster) {
1164 				m = m_getlj((int)resid, M_WAITOK, MT_DATA,
1165 					   top == NULL ? M_PKTHDR : 0, &mlen);
1166 			} else {
1167 				m = m_getl((int)resid, M_WAITOK, MT_DATA,
1168 					   top == NULL ? M_PKTHDR : 0, &mlen);
1169 			}
1170 			if (top == NULL) {
1171 				m->m_pkthdr.len = 0;
1172 				m->m_pkthdr.rcvif = NULL;
1173 			}
1174 			len = imin((int)szmin(mlen, resid), space);
1175 			space -= len;
1176 			error = uiomove(mtod(m, caddr_t), (size_t)len, uio);
1177 			resid = uio->uio_resid;
1178 			m->m_len = len;
1179 			*mp = m;
1180 			top->m_pkthdr.len += len;
1181 			if (error)
1182 				goto release;
1183 			mp = &m->m_next;
1184 			if (resid == 0)
1185 				break;
1186 			++cnt;
1187 		    } while (space > 0 && cnt < tcp_sosend_agglim);
1188 
1189 		    if (tcp_sosend_async)
1190 			    async = 1;
1191 
1192 		    if (flags & MSG_OOB) {
1193 		    	    pru_flags = PRUS_OOB;
1194 			    async = 0;
1195 		    } else if ((flags & MSG_EOF) && resid == 0) {
1196 			    pru_flags = PRUS_EOF;
1197 		    } else if (resid > 0 && space > 0) {
1198 			    /* If there is more to send, set PRUS_MORETOCOME */
1199 		    	    pru_flags = PRUS_MORETOCOME;
1200 			    async = 1;
1201 		    } else {
1202 		    	    pru_flags = 0;
1203 		    }
1204 
1205 		    if (flags & MSG_SYNC)
1206 			    async = 0;
1207 
1208 		    /*
1209 		     * XXX all the SS_CANTSENDMORE checks previously
1210 		     * done could be out of date.  We could have recieved
1211 		     * a reset packet in an interrupt or maybe we slept
1212 		     * while doing page faults in uiomove() etc. We could
1213 		     * probably recheck again inside the splnet() protection
1214 		     * here, but there are probably other places that this
1215 		     * also happens.  We must rethink this.
1216 		     */
1217 		    for (m = top; m; m = m->m_next)
1218 			    ssb_preallocstream(&so->so_snd, m);
1219 		    if (!async) {
1220 			    error = so_pru_send(so, pru_flags, top,
1221 			        NULL, NULL, td);
1222 		    } else {
1223 			    so_pru_send_async(so, pru_flags, top,
1224 			        NULL, NULL, td);
1225 			    error = 0;
1226 		    }
1227 
1228 		    top = NULL;
1229 		    mp = &top;
1230 		    if (error)
1231 			    goto release;
1232 		} while (resid && space > 0);
1233 	} while (resid);
1234 
1235 release:
1236 	ssb_unlock(&so->so_snd);
1237 out:
1238 	if (top)
1239 		m_freem(top);
1240 	if (control)
1241 		m_freem(control);
1242 	return (error);
1243 }
1244 #endif
1245 
1246 /*
1247  * Implement receive operations on a socket.
1248  *
1249  * We depend on the way that records are added to the signalsockbuf
1250  * by sbappend*.  In particular, each record (mbufs linked through m_next)
1251  * must begin with an address if the protocol so specifies,
1252  * followed by an optional mbuf or mbufs containing ancillary data,
1253  * and then zero or more mbufs of data.
1254  *
1255  * Although the signalsockbuf is locked, new data may still be appended.
1256  * A token inside the ssb_lock deals with MP issues and still allows
1257  * the network to access the socket if we block in a uio.
1258  *
1259  * The caller may receive the data as a single mbuf chain by supplying
1260  * sio for use in returning the chain.
1261  */
1262 int
1263 soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
1264 	  struct sockbuf *sio, struct mbuf **controlp, int *flagsp)
1265 {
1266 	struct mbuf *m, *n;
1267 	struct mbuf *free_chain = NULL;
1268 	int flags, len, error, offset;
1269 	struct protosw *pr = so->so_proto;
1270 	int moff, type = 0;
1271 	size_t resid, orig_resid;
1272 	boolean_t free_rights = FALSE;
1273 
1274 	if (uio)
1275 		resid = uio->uio_resid;
1276 	else
1277 		resid = (size_t)(sio->sb_climit - sio->sb_cc);
1278 	orig_resid = resid;
1279 
1280 	if (psa)
1281 		*psa = NULL;
1282 	if (controlp)
1283 		*controlp = NULL;
1284 	if (flagsp)
1285 		flags = *flagsp &~ MSG_EOR;
1286 	else
1287 		flags = 0;
1288 	if (flags & MSG_OOB) {
1289 		m = m_get(M_WAITOK, MT_DATA);
1290 		if (m == NULL)
1291 			return (ENOBUFS);
1292 		error = so_pru_rcvoob(so, m, flags & MSG_PEEK);
1293 		if (error)
1294 			goto bad;
1295 		if (sio) {
1296 			do {
1297 				sbappend(sio, m);
1298 				KKASSERT(resid >= (size_t)m->m_len);
1299 				resid -= (size_t)m->m_len;
1300 				m = m_free(m);
1301 			} while (resid > 0 && m);
1302 		} else {
1303 			do {
1304 				uio->uio_resid = resid;
1305 				error = uiomove(mtod(m, caddr_t),
1306 						(int)szmin(resid, m->m_len),
1307 						uio);
1308 				resid = uio->uio_resid;
1309 				m = m_free(m);
1310 			} while (uio->uio_resid && error == 0 && m);
1311 		}
1312 bad:
1313 		if (m)
1314 			m_freem(m);
1315 		return (error);
1316 	}
1317 	if ((so->so_state & SS_ISCONFIRMING) && resid)
1318 		so_pru_rcvd(so, 0);
1319 
1320 	/*
1321 	 * The token interlocks against the protocol thread while
1322 	 * ssb_lock is a blocking lock against other userland entities.
1323 	 */
1324 	lwkt_gettoken(&so->so_rcv.ssb_token);
1325 restart:
1326 	error = ssb_lock(&so->so_rcv, SBLOCKWAIT(flags));
1327 	if (error)
1328 		goto done;
1329 
1330 	m = so->so_rcv.ssb_mb;
1331 	/*
1332 	 * If we have less data than requested, block awaiting more
1333 	 * (subject to any timeout) if:
1334 	 *   1. the current count is less than the low water mark, or
1335 	 *   2. MSG_WAITALL is set, and it is possible to do the entire
1336 	 *	receive operation at once if we block (resid <= hiwat).
1337 	 *   3. MSG_DONTWAIT is not set
1338 	 * If MSG_WAITALL is set but resid is larger than the receive buffer,
1339 	 * we have to do the receive in sections, and thus risk returning
1340 	 * a short count if a timeout or signal occurs after we start.
1341 	 */
1342 	if (m == NULL || (((flags & MSG_DONTWAIT) == 0 &&
1343 	    (size_t)so->so_rcv.ssb_cc < resid) &&
1344 	    (so->so_rcv.ssb_cc < so->so_rcv.ssb_lowat ||
1345 	    ((flags & MSG_WAITALL) && resid <= (size_t)so->so_rcv.ssb_hiwat)) &&
1346 	    m->m_nextpkt == 0 && (pr->pr_flags & PR_ATOMIC) == 0)) {
1347 		KASSERT(m != NULL || !so->so_rcv.ssb_cc, ("receive 1"));
1348 		if (so->so_error || so->so_rerror) {
1349 			if (m)
1350 				goto dontblock;
1351 			if (so->so_error)
1352 				error = so->so_error;
1353 			else
1354 				error = so->so_rerror;
1355 			if ((flags & MSG_PEEK) == 0) {
1356 				if (so->so_error)
1357 					so->so_error = 0;
1358 				else
1359 					so->so_rerror = 0;
1360 			}
1361 			goto release;
1362 		}
1363 		if (so->so_state & SS_CANTRCVMORE) {
1364 			if (m)
1365 				goto dontblock;
1366 			else
1367 				goto release;
1368 		}
1369 		for (; m; m = m->m_next) {
1370 			if (m->m_type == MT_OOBDATA  || (m->m_flags & M_EOR)) {
1371 				m = so->so_rcv.ssb_mb;
1372 				goto dontblock;
1373 			}
1374 		}
1375 		if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
1376 		    (pr->pr_flags & PR_CONNREQUIRED)) {
1377 			error = ENOTCONN;
1378 			goto release;
1379 		}
1380 		if (resid == 0)
1381 			goto release;
1382 		if (flags & (MSG_FNONBLOCKING|MSG_DONTWAIT)) {
1383 			error = EWOULDBLOCK;
1384 			goto release;
1385 		}
1386 		ssb_unlock(&so->so_rcv);
1387 		error = ssb_wait(&so->so_rcv);
1388 		if (error)
1389 			goto done;
1390 		goto restart;
1391 	}
1392 dontblock:
1393 	if (uio && uio->uio_td && uio->uio_td->td_proc)
1394 		uio->uio_td->td_lwp->lwp_ru.ru_msgrcv++;
1395 
1396 	/*
1397 	 * note: m should be == sb_mb here.  Cache the next record while
1398 	 * cleaning up.  Note that calling m_free*() will break out critical
1399 	 * section.
1400 	 */
1401 	KKASSERT(m == so->so_rcv.ssb_mb);
1402 
1403 	/*
1404 	 * Skip any address mbufs prepending the record.
1405 	 */
1406 	if (pr->pr_flags & PR_ADDR) {
1407 		KASSERT(m->m_type == MT_SONAME, ("receive 1a"));
1408 		orig_resid = 0;
1409 		if (psa)
1410 			*psa = dup_sockaddr(mtod(m, struct sockaddr *));
1411 		if (flags & MSG_PEEK)
1412 			m = m->m_next;
1413 		else
1414 			m = sbunlinkmbuf(&so->so_rcv.sb, m, &free_chain);
1415 	}
1416 
1417 	/*
1418 	 * Skip any control mbufs prepending the record.
1419 	 */
1420 	while (m && m->m_type == MT_CONTROL && error == 0) {
1421 		if (flags & MSG_PEEK) {
1422 			if (controlp)
1423 				*controlp = m_copy(m, 0, m->m_len);
1424 			m = m->m_next;	/* XXX race */
1425 		} else {
1426 			const struct cmsghdr *cm = mtod(m, struct cmsghdr *);
1427 
1428 			if (controlp) {
1429 				n = sbunlinkmbuf(&so->so_rcv.sb, m, NULL);
1430 				if (pr->pr_domain->dom_externalize &&
1431 				    cm->cmsg_level == SOL_SOCKET &&
1432 				    cm->cmsg_type == SCM_RIGHTS) {
1433 					error = pr->pr_domain->dom_externalize
1434 					    (m, flags);
1435 				}
1436 				*controlp = m;
1437 				m = n;
1438 			} else {
1439 				if (cm->cmsg_level == SOL_SOCKET &&
1440 				    cm->cmsg_type == SCM_RIGHTS)
1441 					free_rights = TRUE;
1442 				m = sbunlinkmbuf(&so->so_rcv.sb, m, &free_chain);
1443 			}
1444 		}
1445 		if (controlp && *controlp) {
1446 			orig_resid = 0;
1447 			controlp = &(*controlp)->m_next;
1448 		}
1449 	}
1450 
1451 	/*
1452 	 * flag OOB data.
1453 	 */
1454 	if (m) {
1455 		type = m->m_type;
1456 		if (type == MT_OOBDATA)
1457 			flags |= MSG_OOB;
1458 	}
1459 
1460 	/*
1461 	 * Copy to the UIO or mbuf return chain (*mp).
1462 	 */
1463 	moff = 0;
1464 	offset = 0;
1465 	while (m && resid > 0 && error == 0) {
1466 		if (m->m_type == MT_OOBDATA) {
1467 			if (type != MT_OOBDATA)
1468 				break;
1469 		} else if (type == MT_OOBDATA)
1470 			break;
1471 		else
1472 		    KASSERT(m->m_type == MT_DATA || m->m_type == MT_HEADER,
1473 			("receive 3"));
1474 		soclrstate(so, SS_RCVATMARK);
1475 		len = (resid > INT_MAX) ? INT_MAX : resid;
1476 		if (so->so_oobmark && len > so->so_oobmark - offset)
1477 			len = so->so_oobmark - offset;
1478 		if (len > m->m_len - moff)
1479 			len = m->m_len - moff;
1480 
1481 		/*
1482 		 * Copy out to the UIO or pass the mbufs back to the SIO.
1483 		 * The SIO is dealt with when we eat the mbuf, but deal
1484 		 * with the resid here either way.
1485 		 */
1486 		if (uio) {
1487 			uio->uio_resid = resid;
1488 			error = uiomove(mtod(m, caddr_t) + moff, len, uio);
1489 			resid = uio->uio_resid;
1490 			if (error)
1491 				goto release;
1492 		} else {
1493 			resid -= (size_t)len;
1494 		}
1495 
1496 		/*
1497 		 * Eat the entire mbuf or just a piece of it
1498 		 */
1499 		if (len == m->m_len - moff) {
1500 			if (m->m_flags & M_EOR)
1501 				flags |= MSG_EOR;
1502 			if (flags & MSG_PEEK) {
1503 				m = m->m_next;
1504 				moff = 0;
1505 			} else {
1506 				if (sio) {
1507 					n = sbunlinkmbuf(&so->so_rcv.sb, m, NULL);
1508 					sbappend(sio, m);
1509 					m = n;
1510 				} else {
1511 					m = sbunlinkmbuf(&so->so_rcv.sb, m, &free_chain);
1512 				}
1513 			}
1514 		} else {
1515 			if (flags & MSG_PEEK) {
1516 				moff += len;
1517 			} else {
1518 				if (sio) {
1519 					n = m_copym(m, 0, len, M_WAITOK);
1520 					if (n)
1521 						sbappend(sio, n);
1522 				}
1523 				m->m_data += len;
1524 				m->m_len -= len;
1525 				so->so_rcv.ssb_cc -= len;
1526 			}
1527 		}
1528 		if (so->so_oobmark) {
1529 			if ((flags & MSG_PEEK) == 0) {
1530 				so->so_oobmark -= len;
1531 				if (so->so_oobmark == 0) {
1532 					sosetstate(so, SS_RCVATMARK);
1533 					break;
1534 				}
1535 			} else {
1536 				offset += len;
1537 				if (offset == so->so_oobmark)
1538 					break;
1539 			}
1540 		}
1541 		if (flags & MSG_EOR)
1542 			break;
1543 		/*
1544 		 * If the MSG_WAITALL flag is set (for non-atomic socket),
1545 		 * we must not quit until resid == 0 or an error
1546 		 * termination.  If a signal/timeout occurs, return
1547 		 * with a short count but without error.
1548 		 * Keep signalsockbuf locked against other readers.
1549 		 */
1550 		while ((flags & MSG_WAITALL) && m == NULL &&
1551 		       resid > 0 && !sosendallatonce(so) &&
1552 		       so->so_rcv.ssb_mb == NULL) {
1553 			if (so->so_error || so->so_rerror ||
1554 			    so->so_state & SS_CANTRCVMORE)
1555 				break;
1556 			/*
1557 			 * The window might have closed to zero, make
1558 			 * sure we send an ack now that we've drained
1559 			 * the buffer or we might end up blocking until
1560 			 * the idle takes over (5 seconds).
1561 			 */
1562 			if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
1563 				so_pru_rcvd(so, flags);
1564 			error = ssb_wait(&so->so_rcv);
1565 			if (error) {
1566 				ssb_unlock(&so->so_rcv);
1567 				error = 0;
1568 				goto done;
1569 			}
1570 			m = so->so_rcv.ssb_mb;
1571 		}
1572 	}
1573 
1574 	/*
1575 	 * If an atomic read was requested but unread data still remains
1576 	 * in the record, set MSG_TRUNC.
1577 	 */
1578 	if (m && pr->pr_flags & PR_ATOMIC)
1579 		flags |= MSG_TRUNC;
1580 
1581 	/*
1582 	 * Cleanup.  If an atomic read was requested drop any unread data.
1583 	 */
1584 	if ((flags & MSG_PEEK) == 0) {
1585 		if (m && (pr->pr_flags & PR_ATOMIC))
1586 			sbdroprecord(&so->so_rcv.sb);
1587 		if ((pr->pr_flags & PR_WANTRCVD) && so->so_pcb)
1588 			so_pru_rcvd(so, flags);
1589 	}
1590 
1591 	if (orig_resid == resid && orig_resid &&
1592 	    (flags & MSG_EOR) == 0 && (so->so_state & SS_CANTRCVMORE) == 0) {
1593 		ssb_unlock(&so->so_rcv);
1594 		goto restart;
1595 	}
1596 
1597 	if (flagsp)
1598 		*flagsp |= flags;
1599 release:
1600 	ssb_unlock(&so->so_rcv);
1601 done:
1602 	lwkt_reltoken(&so->so_rcv.ssb_token);
1603 	if (free_chain) {
1604 		if (free_rights && (pr->pr_flags & PR_RIGHTS) &&
1605 		    pr->pr_domain->dom_dispose)
1606 			pr->pr_domain->dom_dispose(free_chain);
1607 		m_freem(free_chain);
1608 	}
1609 	return (error);
1610 }
1611 
1612 int
1613 sorecvtcp(struct socket *so, struct sockaddr **psa, struct uio *uio,
1614 	  struct sockbuf *sio, struct mbuf **controlp, int *flagsp)
1615 {
1616 	struct mbuf *m, *n;
1617 	struct mbuf *free_chain = NULL;
1618 	int flags, len, error, offset;
1619 	struct protosw *pr = so->so_proto;
1620 	int moff;
1621 	int didoob;
1622 	size_t resid, orig_resid, restmp;
1623 
1624 	if (uio)
1625 		resid = uio->uio_resid;
1626 	else
1627 		resid = (size_t)(sio->sb_climit - sio->sb_cc);
1628 	orig_resid = resid;
1629 
1630 	if (psa)
1631 		*psa = NULL;
1632 	if (controlp)
1633 		*controlp = NULL;
1634 	if (flagsp)
1635 		flags = *flagsp &~ MSG_EOR;
1636 	else
1637 		flags = 0;
1638 	if (flags & MSG_OOB) {
1639 		m = m_get(M_WAITOK, MT_DATA);
1640 		if (m == NULL)
1641 			return (ENOBUFS);
1642 		error = so_pru_rcvoob(so, m, flags & MSG_PEEK);
1643 		if (error)
1644 			goto bad;
1645 		if (sio) {
1646 			do {
1647 				sbappend(sio, m);
1648 				KKASSERT(resid >= (size_t)m->m_len);
1649 				resid -= (size_t)m->m_len;
1650 			} while (resid > 0 && m);
1651 		} else {
1652 			do {
1653 				uio->uio_resid = resid;
1654 				error = uiomove(mtod(m, caddr_t),
1655 						(int)szmin(resid, m->m_len),
1656 						uio);
1657 				resid = uio->uio_resid;
1658 				m = m_free(m);
1659 			} while (uio->uio_resid && error == 0 && m);
1660 		}
1661 bad:
1662 		if (m)
1663 			m_freem(m);
1664 		return (error);
1665 	}
1666 
1667 	/*
1668 	 * The token interlocks against the protocol thread while
1669 	 * ssb_lock is a blocking lock against other userland entities.
1670 	 *
1671 	 * Lock a limited number of mbufs (not all, so sbcompress() still
1672 	 * works well).  The token is used as an interlock for sbwait() so
1673 	 * release it afterwords.
1674 	 */
1675 restart:
1676 	error = ssb_lock(&so->so_rcv, SBLOCKWAIT(flags));
1677 	if (error)
1678 		goto done;
1679 
1680 	lwkt_gettoken(&so->so_rcv.ssb_token);
1681 	m = so->so_rcv.ssb_mb;
1682 
1683 	/*
1684 	 * If we have less data than requested, block awaiting more
1685 	 * (subject to any timeout) if:
1686 	 *   1. the current count is less than the low water mark, or
1687 	 *   2. MSG_WAITALL is set, and it is possible to do the entire
1688 	 *	receive operation at once if we block (resid <= hiwat).
1689 	 *   3. MSG_DONTWAIT is not set
1690 	 * If MSG_WAITALL is set but resid is larger than the receive buffer,
1691 	 * we have to do the receive in sections, and thus risk returning
1692 	 * a short count if a timeout or signal occurs after we start.
1693 	 */
1694 	if (m == NULL || (((flags & MSG_DONTWAIT) == 0 &&
1695 	    (size_t)so->so_rcv.ssb_cc < resid) &&
1696 	    (so->so_rcv.ssb_cc < so->so_rcv.ssb_lowat ||
1697 	   ((flags & MSG_WAITALL) && resid <= (size_t)so->so_rcv.ssb_hiwat)))) {
1698 		KASSERT(m != NULL || !so->so_rcv.ssb_cc, ("receive 1"));
1699 		if (so->so_error) {
1700 			if (m)
1701 				goto dontblock;
1702 			lwkt_reltoken(&so->so_rcv.ssb_token);
1703 			error = so->so_error;
1704 			if ((flags & MSG_PEEK) == 0)
1705 				so->so_error = 0;
1706 			goto release;
1707 		}
1708 		if (so->so_state & SS_CANTRCVMORE) {
1709 			if (m)
1710 				goto dontblock;
1711 			lwkt_reltoken(&so->so_rcv.ssb_token);
1712 			goto release;
1713 		}
1714 		if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
1715 		    (pr->pr_flags & PR_CONNREQUIRED)) {
1716 			lwkt_reltoken(&so->so_rcv.ssb_token);
1717 			error = ENOTCONN;
1718 			goto release;
1719 		}
1720 		if (resid == 0) {
1721 			lwkt_reltoken(&so->so_rcv.ssb_token);
1722 			goto release;
1723 		}
1724 		if (flags & (MSG_FNONBLOCKING|MSG_DONTWAIT)) {
1725 			lwkt_reltoken(&so->so_rcv.ssb_token);
1726 			error = EWOULDBLOCK;
1727 			goto release;
1728 		}
1729 		ssb_unlock(&so->so_rcv);
1730 		error = ssb_wait(&so->so_rcv);
1731 		lwkt_reltoken(&so->so_rcv.ssb_token);
1732 		if (error)
1733 			goto done;
1734 		goto restart;
1735 	}
1736 
1737 	/*
1738 	 * Token still held
1739 	 */
1740 dontblock:
1741 	n = m;
1742 	restmp = 0;
1743 	while (n && restmp < resid) {
1744 		n->m_flags |= M_SOLOCKED;
1745 		restmp += n->m_len;
1746 		if (n->m_next == NULL)
1747 			n = n->m_nextpkt;
1748 		else
1749 			n = n->m_next;
1750 	}
1751 
1752 	/*
1753 	 * Release token for loop
1754 	 */
1755 	lwkt_reltoken(&so->so_rcv.ssb_token);
1756 	if (uio && uio->uio_td && uio->uio_td->td_proc)
1757 		uio->uio_td->td_lwp->lwp_ru.ru_msgrcv++;
1758 
1759 	/*
1760 	 * note: m should be == sb_mb here.  Cache the next record while
1761 	 * cleaning up.  Note that calling m_free*() will break out critical
1762 	 * section.
1763 	 */
1764 	KKASSERT(m == so->so_rcv.ssb_mb);
1765 
1766 	/*
1767 	 * Copy to the UIO or mbuf return chain (*mp).
1768 	 *
1769 	 * NOTE: Token is not held for loop
1770 	 */
1771 	moff = 0;
1772 	offset = 0;
1773 	didoob = 0;
1774 
1775 	while (m && (m->m_flags & M_SOLOCKED) && resid > 0 && error == 0) {
1776 		KASSERT(m->m_type == MT_DATA || m->m_type == MT_HEADER,
1777 		    ("receive 3"));
1778 
1779 		soclrstate(so, SS_RCVATMARK);
1780 		len = (resid > INT_MAX) ? INT_MAX : resid;
1781 		if (so->so_oobmark && len > so->so_oobmark - offset)
1782 			len = so->so_oobmark - offset;
1783 		if (len > m->m_len - moff)
1784 			len = m->m_len - moff;
1785 
1786 		/*
1787 		 * Copy out to the UIO or pass the mbufs back to the SIO.
1788 		 * The SIO is dealt with when we eat the mbuf, but deal
1789 		 * with the resid here either way.
1790 		 */
1791 		if (uio) {
1792 			uio->uio_resid = resid;
1793 			error = uiomove(mtod(m, caddr_t) + moff, len, uio);
1794 			resid = uio->uio_resid;
1795 			if (error)
1796 				goto release;
1797 		} else {
1798 			resid -= (size_t)len;
1799 		}
1800 
1801 		/*
1802 		 * Eat the entire mbuf or just a piece of it
1803 		 */
1804 		offset += len;
1805 		if (len == m->m_len - moff) {
1806 			m = m->m_next;
1807 			moff = 0;
1808 		} else {
1809 			moff += len;
1810 		}
1811 
1812 		/*
1813 		 * Check oobmark
1814 		 */
1815 		if (so->so_oobmark && offset == so->so_oobmark) {
1816 			didoob = 1;
1817 			break;
1818 		}
1819 	}
1820 
1821 	/*
1822 	 * Synchronize sockbuf with data we read.
1823 	 *
1824 	 * NOTE: (m) is junk on entry (it could be left over from the
1825 	 *	 previous loop).
1826 	 */
1827 	if ((flags & MSG_PEEK) == 0) {
1828 		lwkt_gettoken(&so->so_rcv.ssb_token);
1829 		m = so->so_rcv.ssb_mb;
1830 		while (m && offset >= m->m_len) {
1831 			if (so->so_oobmark) {
1832 				so->so_oobmark -= m->m_len;
1833 				if (so->so_oobmark == 0) {
1834 					sosetstate(so, SS_RCVATMARK);
1835 					didoob = 1;
1836 				}
1837 			}
1838 			offset -= m->m_len;
1839 			if (sio) {
1840 				n = sbunlinkmbuf(&so->so_rcv.sb, m, NULL);
1841 				sbappend(sio, m);
1842 				m = n;
1843 			} else {
1844 				m = sbunlinkmbuf(&so->so_rcv.sb,
1845 						 m, &free_chain);
1846 			}
1847 		}
1848 		if (offset) {
1849 			KKASSERT(m);
1850 			if (sio) {
1851 				n = m_copym(m, 0, offset, M_WAITOK);
1852 				if (n)
1853 					sbappend(sio, n);
1854 			}
1855 			m->m_data += offset;
1856 			m->m_len -= offset;
1857 			so->so_rcv.ssb_cc -= offset;
1858 			if (so->so_oobmark) {
1859 				so->so_oobmark -= offset;
1860 				if (so->so_oobmark == 0) {
1861 					sosetstate(so, SS_RCVATMARK);
1862 					didoob = 1;
1863 				}
1864 			}
1865 			offset = 0;
1866 		}
1867 		lwkt_reltoken(&so->so_rcv.ssb_token);
1868 	}
1869 
1870 	/*
1871 	 * If the MSG_WAITALL flag is set (for non-atomic socket),
1872 	 * we must not quit until resid == 0 or an error termination.
1873 	 *
1874 	 * If a signal/timeout occurs, return with a short count but without
1875 	 * error.
1876 	 *
1877 	 * Keep signalsockbuf locked against other readers.
1878 	 *
1879 	 * XXX if MSG_PEEK we currently do quit.
1880 	 */
1881 	if ((flags & MSG_WAITALL) && !(flags & MSG_PEEK) &&
1882 	    didoob == 0 && resid > 0 &&
1883 	    !sosendallatonce(so)) {
1884 		lwkt_gettoken(&so->so_rcv.ssb_token);
1885 		error = 0;
1886 		while ((m = so->so_rcv.ssb_mb) == NULL) {
1887 			if (so->so_error || (so->so_state & SS_CANTRCVMORE)) {
1888 				error = so->so_error;
1889 				break;
1890 			}
1891 			/*
1892 			 * The window might have closed to zero, make
1893 			 * sure we send an ack now that we've drained
1894 			 * the buffer or we might end up blocking until
1895 			 * the idle takes over (5 seconds).
1896 			 */
1897 			if (so->so_pcb)
1898 				so_pru_rcvd_async(so);
1899 			if (so->so_rcv.ssb_mb == NULL)
1900 				error = ssb_wait(&so->so_rcv);
1901 			if (error) {
1902 				lwkt_reltoken(&so->so_rcv.ssb_token);
1903 				ssb_unlock(&so->so_rcv);
1904 				error = 0;
1905 				goto done;
1906 			}
1907 		}
1908 		if (m && error == 0)
1909 			goto dontblock;
1910 		lwkt_reltoken(&so->so_rcv.ssb_token);
1911 	}
1912 
1913 	/*
1914 	 * Token not held here.
1915 	 *
1916 	 * Cleanup.  If an atomic read was requested drop any unread data XXX
1917 	 */
1918 	if ((flags & MSG_PEEK) == 0) {
1919 		if (so->so_pcb)
1920 			so_pru_rcvd_async(so);
1921 	}
1922 
1923 	if (orig_resid == resid && orig_resid &&
1924 	    (so->so_state & SS_CANTRCVMORE) == 0) {
1925 		ssb_unlock(&so->so_rcv);
1926 		goto restart;
1927 	}
1928 
1929 	if (flagsp)
1930 		*flagsp |= flags;
1931 release:
1932 	ssb_unlock(&so->so_rcv);
1933 done:
1934 	if (free_chain)
1935 		m_freem(free_chain);
1936 	return (error);
1937 }
1938 
1939 /*
1940  * Shut a socket down.  Note that we do not get a frontend lock as we
1941  * want to be able to shut the socket down even if another thread is
1942  * blocked in a read(), thus waking it up.
1943  */
1944 int
1945 soshutdown(struct socket *so, int how)
1946 {
1947 	if (!(how == SHUT_RD || how == SHUT_WR || how == SHUT_RDWR))
1948 		return (EINVAL);
1949 
1950 	if (how != SHUT_WR) {
1951 		/*ssb_lock(&so->so_rcv, M_WAITOK);*/
1952 		sorflush(so);
1953 		/*ssb_unlock(&so->so_rcv);*/
1954 	}
1955 	if (how != SHUT_RD)
1956 		return (so_pru_shutdown(so));
1957 	return (0);
1958 }
1959 
1960 void
1961 sorflush(struct socket *so)
1962 {
1963 	struct signalsockbuf *ssb = &so->so_rcv;
1964 	struct protosw *pr = so->so_proto;
1965 	struct signalsockbuf asb;
1966 
1967 	atomic_set_int(&ssb->ssb_flags, SSB_NOINTR);
1968 
1969 	lwkt_gettoken(&ssb->ssb_token);
1970 	socantrcvmore(so);
1971 	asb = *ssb;
1972 
1973 	/*
1974 	 * Can't just blow up the ssb structure here
1975 	 */
1976 	bzero(&ssb->sb, sizeof(ssb->sb));
1977 	ssb->ssb_timeo = 0;
1978 	ssb->ssb_lowat = 0;
1979 	ssb->ssb_hiwat = 0;
1980 	ssb->ssb_mbmax = 0;
1981 	atomic_clear_int(&ssb->ssb_flags, SSB_CLEAR_MASK);
1982 
1983 	if ((pr->pr_flags & PR_RIGHTS) && pr->pr_domain->dom_dispose)
1984 		(*pr->pr_domain->dom_dispose)(asb.ssb_mb);
1985 	ssb_release(&asb, so);
1986 
1987 	lwkt_reltoken(&ssb->ssb_token);
1988 }
1989 
1990 #ifdef INET
1991 static int
1992 do_setopt_accept_filter(struct socket *so, struct sockopt *sopt)
1993 {
1994 	struct accept_filter_arg	*afap = NULL;
1995 	struct accept_filter	*afp;
1996 	struct so_accf	*af = so->so_accf;
1997 	int	error = 0;
1998 
1999 	/* do not set/remove accept filters on non listen sockets */
2000 	if ((so->so_options & SO_ACCEPTCONN) == 0) {
2001 		error = EINVAL;
2002 		goto out;
2003 	}
2004 
2005 	/* removing the filter */
2006 	if (sopt == NULL) {
2007 		if (af != NULL) {
2008 			if (af->so_accept_filter != NULL &&
2009 				af->so_accept_filter->accf_destroy != NULL) {
2010 				af->so_accept_filter->accf_destroy(so);
2011 			}
2012 			if (af->so_accept_filter_str != NULL) {
2013 				kfree(af->so_accept_filter_str, M_ACCF);
2014 			}
2015 			kfree(af, M_ACCF);
2016 			so->so_accf = NULL;
2017 		}
2018 		so->so_options &= ~SO_ACCEPTFILTER;
2019 		return (0);
2020 	}
2021 	/* adding a filter */
2022 	/* must remove previous filter first */
2023 	if (af != NULL) {
2024 		error = EINVAL;
2025 		goto out;
2026 	}
2027 	/* don't put large objects on the kernel stack */
2028 	afap = kmalloc(sizeof(*afap), M_TEMP, M_WAITOK);
2029 	error = sooptcopyin(sopt, afap, sizeof *afap, sizeof *afap);
2030 	afap->af_name[sizeof(afap->af_name)-1] = '\0';
2031 	afap->af_arg[sizeof(afap->af_arg)-1] = '\0';
2032 	if (error)
2033 		goto out;
2034 	afp = accept_filt_get(afap->af_name);
2035 	if (afp == NULL) {
2036 		error = ENOENT;
2037 		goto out;
2038 	}
2039 	af = kmalloc(sizeof(*af), M_ACCF, M_WAITOK | M_ZERO);
2040 	if (afp->accf_create != NULL) {
2041 		if (afap->af_name[0] != '\0') {
2042 			int len = strlen(afap->af_name) + 1;
2043 
2044 			af->so_accept_filter_str = kmalloc(len, M_ACCF,
2045 							   M_WAITOK);
2046 			strcpy(af->so_accept_filter_str, afap->af_name);
2047 		}
2048 		af->so_accept_filter_arg = afp->accf_create(so, afap->af_arg);
2049 		if (af->so_accept_filter_arg == NULL) {
2050 			kfree(af->so_accept_filter_str, M_ACCF);
2051 			kfree(af, M_ACCF);
2052 			so->so_accf = NULL;
2053 			error = EINVAL;
2054 			goto out;
2055 		}
2056 	}
2057 	af->so_accept_filter = afp;
2058 	so->so_accf = af;
2059 	so->so_options |= SO_ACCEPTFILTER;
2060 out:
2061 	if (afap != NULL)
2062 		kfree(afap, M_TEMP);
2063 	return (error);
2064 }
2065 #endif /* INET */
2066 
2067 /*
2068  * Perhaps this routine, and sooptcopyout(), below, ought to come in
2069  * an additional variant to handle the case where the option value needs
2070  * to be some kind of integer, but not a specific size.
2071  * In addition to their use here, these functions are also called by the
2072  * protocol-level pr_ctloutput() routines.
2073  */
2074 int
2075 sooptcopyin(struct sockopt *sopt, void *buf, size_t len, size_t minlen)
2076 {
2077 	return soopt_to_kbuf(sopt, buf, len, minlen);
2078 }
2079 
2080 int
2081 soopt_to_kbuf(struct sockopt *sopt, void *buf, size_t len, size_t minlen)
2082 {
2083 	size_t	valsize;
2084 
2085 	KKASSERT(!sopt->sopt_val || kva_p(sopt->sopt_val));
2086 	KKASSERT(kva_p(buf));
2087 
2088 	/*
2089 	 * If the user gives us more than we wanted, we ignore it,
2090 	 * but if we don't get the minimum length the caller
2091 	 * wants, we return EINVAL.  On success, sopt->sopt_valsize
2092 	 * is set to however much we actually retrieved.
2093 	 */
2094 	if ((valsize = sopt->sopt_valsize) < minlen)
2095 		return EINVAL;
2096 	if (valsize > len)
2097 		sopt->sopt_valsize = valsize = len;
2098 
2099 	bcopy(sopt->sopt_val, buf, valsize);
2100 	return 0;
2101 }
2102 
2103 
2104 int
2105 sosetopt(struct socket *so, struct sockopt *sopt)
2106 {
2107 	int	error, optval;
2108 	struct	linger l;
2109 	struct	timeval tv;
2110 	u_long  val;
2111 	struct signalsockbuf *sotmp;
2112 
2113 	error = 0;
2114 	sopt->sopt_dir = SOPT_SET;
2115 	if (sopt->sopt_level != SOL_SOCKET) {
2116 		if (so->so_proto && so->so_proto->pr_ctloutput) {
2117 			return (so_pr_ctloutput(so, sopt));
2118 		}
2119 		error = ENOPROTOOPT;
2120 	} else {
2121 		switch (sopt->sopt_name) {
2122 #ifdef INET
2123 		case SO_ACCEPTFILTER:
2124 			error = do_setopt_accept_filter(so, sopt);
2125 			if (error)
2126 				goto bad;
2127 			break;
2128 #endif /* INET */
2129 		case SO_LINGER:
2130 			error = sooptcopyin(sopt, &l, sizeof l, sizeof l);
2131 			if (error)
2132 				goto bad;
2133 
2134 			so->so_linger = l.l_linger;
2135 			if (l.l_onoff)
2136 				so->so_options |= SO_LINGER;
2137 			else
2138 				so->so_options &= ~SO_LINGER;
2139 			break;
2140 
2141 		case SO_DEBUG:
2142 		case SO_KEEPALIVE:
2143 		case SO_DONTROUTE:
2144 		case SO_USELOOPBACK:
2145 		case SO_BROADCAST:
2146 		case SO_REUSEADDR:
2147 		case SO_REUSEPORT:
2148 		case SO_OOBINLINE:
2149 		case SO_TIMESTAMP:
2150 		case SO_NOSIGPIPE:
2151 		case SO_RERROR:
2152 		case SO_PASSCRED:
2153 			error = sooptcopyin(sopt, &optval, sizeof optval,
2154 					    sizeof optval);
2155 			if (error)
2156 				goto bad;
2157 			if (optval)
2158 				so->so_options |= sopt->sopt_name;
2159 			else
2160 				so->so_options &= ~sopt->sopt_name;
2161 			break;
2162 
2163 		case SO_SNDBUF:
2164 		case SO_RCVBUF:
2165 		case SO_SNDLOWAT:
2166 		case SO_RCVLOWAT:
2167 			error = sooptcopyin(sopt, &optval, sizeof optval,
2168 					    sizeof optval);
2169 			if (error)
2170 				goto bad;
2171 
2172 			/*
2173 			 * Values < 1 make no sense for any of these
2174 			 * options, so disallow them.
2175 			 */
2176 			if (optval < 1) {
2177 				error = EINVAL;
2178 				goto bad;
2179 			}
2180 
2181 			switch (sopt->sopt_name) {
2182 			case SO_SNDBUF:
2183 			case SO_RCVBUF:
2184 				if (ssb_reserve(sopt->sopt_name == SO_SNDBUF ?
2185 				    &so->so_snd : &so->so_rcv, (u_long)optval,
2186 				    so,
2187 				    &curproc->p_rlimit[RLIMIT_SBSIZE]) == 0) {
2188 					error = ENOBUFS;
2189 					goto bad;
2190 				}
2191 				sotmp = (sopt->sopt_name == SO_SNDBUF) ?
2192 						&so->so_snd : &so->so_rcv;
2193 				atomic_clear_int(&sotmp->ssb_flags,
2194 						 SSB_AUTOSIZE);
2195 				break;
2196 
2197 			/*
2198 			 * Make sure the low-water is never greater than
2199 			 * the high-water.
2200 			 */
2201 			case SO_SNDLOWAT:
2202 				so->so_snd.ssb_lowat =
2203 				    (optval > so->so_snd.ssb_hiwat) ?
2204 				    so->so_snd.ssb_hiwat : optval;
2205 				atomic_clear_int(&so->so_snd.ssb_flags,
2206 						 SSB_AUTOLOWAT);
2207 				break;
2208 			case SO_RCVLOWAT:
2209 				so->so_rcv.ssb_lowat =
2210 				    (optval > so->so_rcv.ssb_hiwat) ?
2211 				    so->so_rcv.ssb_hiwat : optval;
2212 				atomic_clear_int(&so->so_rcv.ssb_flags,
2213 						 SSB_AUTOLOWAT);
2214 				break;
2215 			}
2216 			break;
2217 
2218 		case SO_SNDTIMEO:
2219 		case SO_RCVTIMEO:
2220 			error = sooptcopyin(sopt, &tv, sizeof tv,
2221 					    sizeof tv);
2222 			if (error)
2223 				goto bad;
2224 
2225 			/* assert(hz > 0); */
2226 			if (tv.tv_sec < 0 || tv.tv_sec > INT_MAX / hz ||
2227 			    tv.tv_usec < 0 || tv.tv_usec >= 1000000) {
2228 				error = EDOM;
2229 				goto bad;
2230 			}
2231 			/* assert(tick > 0); */
2232 			/* assert(ULONG_MAX - INT_MAX >= 1000000); */
2233 			val = (u_long)(tv.tv_sec * hz) + tv.tv_usec / ustick;
2234 			if (val > INT_MAX) {
2235 				error = EDOM;
2236 				goto bad;
2237 			}
2238 			if (val == 0 && tv.tv_usec != 0)
2239 				val = 1;
2240 
2241 			switch (sopt->sopt_name) {
2242 			case SO_SNDTIMEO:
2243 				so->so_snd.ssb_timeo = val;
2244 				break;
2245 			case SO_RCVTIMEO:
2246 				so->so_rcv.ssb_timeo = val;
2247 				break;
2248 			}
2249 			break;
2250 		default:
2251 			error = ENOPROTOOPT;
2252 			break;
2253 		}
2254 		if (error == 0 && so->so_proto && so->so_proto->pr_ctloutput) {
2255 			(void) so_pr_ctloutput(so, sopt);
2256 		}
2257 	}
2258 bad:
2259 	return (error);
2260 }
2261 
2262 /* Helper routine for getsockopt */
2263 int
2264 sooptcopyout(struct sockopt *sopt, const void *buf, size_t len)
2265 {
2266 	soopt_from_kbuf(sopt, buf, len);
2267 	return 0;
2268 }
2269 
2270 void
2271 soopt_from_kbuf(struct sockopt *sopt, const void *buf, size_t len)
2272 {
2273 	size_t	valsize;
2274 
2275 	if (len == 0) {
2276 		sopt->sopt_valsize = 0;
2277 		return;
2278 	}
2279 
2280 	KKASSERT(!sopt->sopt_val || kva_p(sopt->sopt_val));
2281 	KKASSERT(kva_p(buf));
2282 
2283 	/*
2284 	 * Documented get behavior is that we always return a value,
2285 	 * possibly truncated to fit in the user's buffer.
2286 	 * Traditional behavior is that we always tell the user
2287 	 * precisely how much we copied, rather than something useful
2288 	 * like the total amount we had available for her.
2289 	 * Note that this interface is not idempotent; the entire answer must
2290 	 * generated ahead of time.
2291 	 */
2292 	valsize = szmin(len, sopt->sopt_valsize);
2293 	sopt->sopt_valsize = valsize;
2294 	if (sopt->sopt_val != 0) {
2295 		bcopy(buf, sopt->sopt_val, valsize);
2296 	}
2297 }
2298 
2299 int
2300 sogetopt(struct socket *so, struct sockopt *sopt)
2301 {
2302 	int	error, optval;
2303 	long	optval_l;
2304 	struct	linger l;
2305 	struct	timeval tv;
2306 #ifdef INET
2307 	struct accept_filter_arg *afap;
2308 #endif
2309 
2310 	error = 0;
2311 	sopt->sopt_dir = SOPT_GET;
2312 	if (sopt->sopt_level != SOL_SOCKET) {
2313 		if (so->so_proto && so->so_proto->pr_ctloutput) {
2314 			return (so_pr_ctloutput(so, sopt));
2315 		} else
2316 			return (ENOPROTOOPT);
2317 	} else {
2318 		switch (sopt->sopt_name) {
2319 #ifdef INET
2320 		case SO_ACCEPTFILTER:
2321 			if ((so->so_options & SO_ACCEPTCONN) == 0)
2322 				return (EINVAL);
2323 			afap = kmalloc(sizeof(*afap), M_TEMP,
2324 				       M_WAITOK | M_ZERO);
2325 			if ((so->so_options & SO_ACCEPTFILTER) != 0) {
2326 				strcpy(afap->af_name, so->so_accf->so_accept_filter->accf_name);
2327 				if (so->so_accf->so_accept_filter_str != NULL)
2328 					strcpy(afap->af_arg, so->so_accf->so_accept_filter_str);
2329 			}
2330 			error = sooptcopyout(sopt, afap, sizeof(*afap));
2331 			kfree(afap, M_TEMP);
2332 			break;
2333 #endif /* INET */
2334 
2335 		case SO_LINGER:
2336 			l.l_onoff = so->so_options & SO_LINGER;
2337 			l.l_linger = so->so_linger;
2338 			error = sooptcopyout(sopt, &l, sizeof l);
2339 			break;
2340 
2341 		case SO_USELOOPBACK:
2342 		case SO_DONTROUTE:
2343 		case SO_DEBUG:
2344 		case SO_KEEPALIVE:
2345 		case SO_REUSEADDR:
2346 		case SO_REUSEPORT:
2347 		case SO_BROADCAST:
2348 		case SO_OOBINLINE:
2349 		case SO_TIMESTAMP:
2350 		case SO_NOSIGPIPE:
2351 		case SO_RERROR:
2352 		case SO_PASSCRED:
2353 			optval = so->so_options & sopt->sopt_name;
2354 integer:
2355 			error = sooptcopyout(sopt, &optval, sizeof optval);
2356 			break;
2357 
2358 		case SO_TYPE:
2359 			optval = so->so_type;
2360 			goto integer;
2361 
2362 		case SO_ERROR:
2363 			if (so->so_error) {
2364 				optval = so->so_error;
2365 				so->so_error = 0;
2366 			} else {
2367 				optval = so->so_rerror;
2368 				so->so_rerror = 0;
2369 			}
2370 			goto integer;
2371 
2372 		case SO_SNDBUF:
2373 			optval = so->so_snd.ssb_hiwat;
2374 			goto integer;
2375 
2376 		case SO_RCVBUF:
2377 			optval = so->so_rcv.ssb_hiwat;
2378 			goto integer;
2379 
2380 		case SO_SNDLOWAT:
2381 			optval = so->so_snd.ssb_lowat;
2382 			goto integer;
2383 
2384 		case SO_RCVLOWAT:
2385 			optval = so->so_rcv.ssb_lowat;
2386 			goto integer;
2387 
2388 		case SO_SNDTIMEO:
2389 		case SO_RCVTIMEO:
2390 			optval = (sopt->sopt_name == SO_SNDTIMEO ?
2391 				  so->so_snd.ssb_timeo : so->so_rcv.ssb_timeo);
2392 
2393 			tv.tv_sec = optval / hz;
2394 			tv.tv_usec = (optval % hz) * ustick;
2395 			error = sooptcopyout(sopt, &tv, sizeof tv);
2396 			break;
2397 
2398 		case SO_SNDSPACE:
2399 			optval_l = ssb_space(&so->so_snd);
2400 			error = sooptcopyout(sopt, &optval_l, sizeof(optval_l));
2401 			break;
2402 
2403 		case SO_CPUHINT:
2404 			optval = -1; /* no hint */
2405 			goto integer;
2406 
2407 		default:
2408 			error = ENOPROTOOPT;
2409 			break;
2410 		}
2411 		if (error == 0 && so->so_proto && so->so_proto->pr_ctloutput)
2412 			so_pr_ctloutput(so, sopt);
2413 		return (error);
2414 	}
2415 }
2416 
2417 /* XXX; prepare mbuf for (__FreeBSD__ < 3) routines. */
2418 int
2419 soopt_getm(struct sockopt *sopt, struct mbuf **mp)
2420 {
2421 	struct mbuf *m, *m_prev;
2422 	int sopt_size = sopt->sopt_valsize, msize;
2423 
2424 	m = m_getl(sopt_size, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA,
2425 		   0, &msize);
2426 	if (m == NULL)
2427 		return (ENOBUFS);
2428 	m->m_len = min(msize, sopt_size);
2429 	sopt_size -= m->m_len;
2430 	*mp = m;
2431 	m_prev = m;
2432 
2433 	while (sopt_size > 0) {
2434 		m = m_getl(sopt_size, sopt->sopt_td ? M_WAITOK : M_NOWAIT,
2435 			   MT_DATA, 0, &msize);
2436 		if (m == NULL) {
2437 			m_freem(*mp);
2438 			return (ENOBUFS);
2439 		}
2440 		m->m_len = min(msize, sopt_size);
2441 		sopt_size -= m->m_len;
2442 		m_prev->m_next = m;
2443 		m_prev = m;
2444 	}
2445 	return (0);
2446 }
2447 
2448 /* XXX; copyin sopt data into mbuf chain for (__FreeBSD__ < 3) routines. */
2449 int
2450 soopt_mcopyin(struct sockopt *sopt, struct mbuf *m)
2451 {
2452 	soopt_to_mbuf(sopt, m);
2453 	return 0;
2454 }
2455 
2456 void
2457 soopt_to_mbuf(struct sockopt *sopt, struct mbuf *m)
2458 {
2459 	size_t valsize;
2460 	void *val;
2461 
2462 	KKASSERT(!sopt->sopt_val || kva_p(sopt->sopt_val));
2463 	KKASSERT(kva_p(m));
2464 	if (sopt->sopt_val == NULL)
2465 		return;
2466 	val = sopt->sopt_val;
2467 	valsize = sopt->sopt_valsize;
2468 	while (m != NULL && valsize >= m->m_len) {
2469 		bcopy(val, mtod(m, char *), m->m_len);
2470 		valsize -= m->m_len;
2471 		val = (caddr_t)val + m->m_len;
2472 		m = m->m_next;
2473 	}
2474 	if (m != NULL) /* should be allocated enoughly at ip6_sooptmcopyin() */
2475 		panic("ip6_sooptmcopyin");
2476 }
2477 
2478 /* XXX; copyout mbuf chain data into soopt for (__FreeBSD__ < 3) routines. */
2479 int
2480 soopt_mcopyout(struct sockopt *sopt, struct mbuf *m)
2481 {
2482 	return soopt_from_mbuf(sopt, m);
2483 }
2484 
2485 int
2486 soopt_from_mbuf(struct sockopt *sopt, struct mbuf *m)
2487 {
2488 	struct mbuf *m0 = m;
2489 	size_t valsize = 0;
2490 	size_t maxsize;
2491 	void *val;
2492 
2493 	KKASSERT(!sopt->sopt_val || kva_p(sopt->sopt_val));
2494 	KKASSERT(kva_p(m));
2495 	if (sopt->sopt_val == NULL)
2496 		return 0;
2497 	val = sopt->sopt_val;
2498 	maxsize = sopt->sopt_valsize;
2499 	while (m != NULL && maxsize >= m->m_len) {
2500 		bcopy(mtod(m, char *), val, m->m_len);
2501 	       maxsize -= m->m_len;
2502 	       val = (caddr_t)val + m->m_len;
2503 	       valsize += m->m_len;
2504 	       m = m->m_next;
2505 	}
2506 	if (m != NULL) {
2507 		/* enough soopt buffer should be given from user-land */
2508 		m_freem(m0);
2509 		return (EINVAL);
2510 	}
2511 	sopt->sopt_valsize = valsize;
2512 	return 0;
2513 }
2514 
2515 void
2516 sohasoutofband(struct socket *so)
2517 {
2518 	if (so->so_sigio != NULL)
2519 		pgsigio(so->so_sigio, SIGURG, 0);
2520 	/*
2521 	 * NOTE:
2522 	 * There is no need to use NOTE_OOB as KNOTE hint here:
2523 	 * soread filter depends on so_oobmark and SS_RCVATMARK
2524 	 * so_state.  NOTE_OOB would cause unnecessary penalty
2525 	 * in KNOTE, if there was knote processing contention.
2526 	 */
2527 	KNOTE(&so->so_rcv.ssb_kq.ki_note, 0);
2528 }
2529 
2530 int
2531 sokqfilter(struct file *fp, struct knote *kn)
2532 {
2533 	struct socket *so = (struct socket *)kn->kn_fp->f_data;
2534 	struct signalsockbuf *ssb;
2535 
2536 	switch (kn->kn_filter) {
2537 	case EVFILT_READ:
2538 		if (so->so_options & SO_ACCEPTCONN)
2539 			kn->kn_fop = &solisten_filtops;
2540 		else
2541 			kn->kn_fop = &soread_filtops;
2542 		ssb = &so->so_rcv;
2543 		break;
2544 	case EVFILT_WRITE:
2545 		kn->kn_fop = &sowrite_filtops;
2546 		ssb = &so->so_snd;
2547 		break;
2548 	case EVFILT_EXCEPT:
2549 		kn->kn_fop = &soexcept_filtops;
2550 		ssb = &so->so_rcv;
2551 		break;
2552 	default:
2553 		return (EOPNOTSUPP);
2554 	}
2555 
2556 	knote_insert(&ssb->ssb_kq.ki_note, kn);
2557 	atomic_set_int(&ssb->ssb_flags, SSB_KNOTE);
2558 	return (0);
2559 }
2560 
2561 static void
2562 filt_sordetach(struct knote *kn)
2563 {
2564 	struct socket *so = (struct socket *)kn->kn_fp->f_data;
2565 
2566 	knote_remove(&so->so_rcv.ssb_kq.ki_note, kn);
2567 	if (SLIST_EMPTY(&so->so_rcv.ssb_kq.ki_note))
2568 		atomic_clear_int(&so->so_rcv.ssb_flags, SSB_KNOTE);
2569 }
2570 
2571 /*ARGSUSED*/
2572 static int
2573 filt_soread(struct knote *kn, long hint __unused)
2574 {
2575 	struct socket *so = (struct socket *)kn->kn_fp->f_data;
2576 
2577 	if (kn->kn_sfflags & NOTE_OOB) {
2578 		if ((so->so_oobmark || (so->so_state & SS_RCVATMARK))) {
2579 			kn->kn_fflags |= NOTE_OOB;
2580 			return (1);
2581 		}
2582 		return (0);
2583 	}
2584 	kn->kn_data = so->so_rcv.ssb_cc;
2585 
2586 	if (so->so_state & SS_CANTRCVMORE) {
2587 		/*
2588 		 * Only set NODATA if all data has been exhausted.
2589 		 *
2590 		 * If HUPONLY is flagged, linux only issues the HUP on
2591 		 * a fully closed socket, not a half-closed socket.
2592 		 *
2593 		 * LOWAT is not applicable with a pending EOF.
2594 		 *
2595 		 * WARNING: If we issue a spurious event to poll() it will
2596 		 *	    de-register the event.
2597 		 */
2598 		if (kn->kn_data == 0)
2599 			kn->kn_flags |= EV_NODATA;
2600 		kn->kn_flags |= EV_EOF;
2601 		kn->kn_fflags = so->so_error;
2602 		if (so->so_state & SS_CANTSENDMORE) {
2603 			kn->kn_flags |= EV_HUP;
2604 			return (1);
2605 		}
2606 		if ((kn->kn_sfflags & NOTE_HUPONLY) == 0)
2607 			return (1);
2608 		return 0;
2609 	}
2610 	if (so->so_error || so->so_rerror)
2611 		return (1);
2612 
2613 	/*
2614 	 * Normal operation if HUPONLY is not set.  If HUPONLY is set
2615 	 * we only return positive on EOF/HUP above.
2616 	 *
2617 	 * WARNING: If we issue a spurious event to poll() it will de-register
2618 	 *	    the event.
2619 	 */
2620 	if ((kn->kn_sfflags & NOTE_HUPONLY) == 0) {
2621 		if (kn->kn_sfflags & NOTE_LOWAT)
2622 			return (kn->kn_data >= kn->kn_sdata);
2623 		return ((kn->kn_data >= so->so_rcv.ssb_lowat) ||
2624 			!TAILQ_EMPTY(&so->so_comp));
2625 	}
2626 	return 0;
2627 }
2628 
2629 static void
2630 filt_sowdetach(struct knote *kn)
2631 {
2632 	struct socket *so = (struct socket *)kn->kn_fp->f_data;
2633 
2634 	knote_remove(&so->so_snd.ssb_kq.ki_note, kn);
2635 	if (SLIST_EMPTY(&so->so_snd.ssb_kq.ki_note))
2636 		atomic_clear_int(&so->so_snd.ssb_flags, SSB_KNOTE);
2637 }
2638 
2639 /*ARGSUSED*/
2640 static int
2641 filt_sowrite(struct knote *kn, long hint __unused)
2642 {
2643 	struct socket *so = (struct socket *)kn->kn_fp->f_data;
2644 
2645 	if (so->so_snd.ssb_flags & SSB_PREALLOC)
2646 		kn->kn_data = ssb_space_prealloc(&so->so_snd);
2647 	else
2648 		kn->kn_data = ssb_space(&so->so_snd);
2649 
2650 	if (so->so_state & SS_CANTSENDMORE) {
2651 		kn->kn_flags |= (EV_EOF | EV_NODATA);
2652 		if (so->so_state & SS_CANTRCVMORE)
2653 			kn->kn_flags |= EV_HUP;
2654 		kn->kn_fflags = so->so_error;
2655 		return (1);
2656 	}
2657 	if (so->so_error)	/* temporary udp error */
2658 		return (1);
2659 	if (((so->so_state & SS_ISCONNECTED) == 0) &&
2660 	    (so->so_proto->pr_flags & PR_CONNREQUIRED))
2661 		return (0);
2662 	if (kn->kn_sfflags & NOTE_LOWAT)
2663 		return (kn->kn_data >= kn->kn_sdata);
2664 	return (kn->kn_data >= so->so_snd.ssb_lowat);
2665 }
2666 
2667 /*ARGSUSED*/
2668 static int
2669 filt_solisten(struct knote *kn, long hint __unused)
2670 {
2671 	struct socket *so = (struct socket *)kn->kn_fp->f_data;
2672 	int qlen = so->so_qlen;
2673 
2674 	if (soavailconn > 0 && qlen > soavailconn)
2675 		qlen = soavailconn;
2676 	kn->kn_data = qlen;
2677 
2678 	return (!TAILQ_EMPTY(&so->so_comp));
2679 }
2680