xref: /netbsd-src/sys/kern/uipc_socket.c (revision ba65fde2d7fefa7d39838fa5fa855e62bd606b5e)
1 /*	$NetBSD: uipc_socket.c,v 1.213 2013/02/14 21:57:58 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2002, 2007, 2008, 2009 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe of Wasabi Systems, Inc, and by Andrew Doran.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 2004 The FreeBSD Foundation
34  * Copyright (c) 2004 Robert Watson
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	8.6 (Berkeley) 5/2/95
63  */
64 
65 #include <sys/cdefs.h>
66 __KERNEL_RCSID(0, "$NetBSD: uipc_socket.c,v 1.213 2013/02/14 21:57:58 christos Exp $");
67 
68 #include "opt_compat_netbsd.h"
69 #include "opt_sock_counters.h"
70 #include "opt_sosend_loan.h"
71 #include "opt_mbuftrace.h"
72 #include "opt_somaxkva.h"
73 #include "opt_multiprocessor.h"	/* XXX */
74 
75 #include <sys/param.h>
76 #include <sys/systm.h>
77 #include <sys/proc.h>
78 #include <sys/file.h>
79 #include <sys/filedesc.h>
80 #include <sys/kmem.h>
81 #include <sys/mbuf.h>
82 #include <sys/domain.h>
83 #include <sys/kernel.h>
84 #include <sys/protosw.h>
85 #include <sys/socket.h>
86 #include <sys/socketvar.h>
87 #include <sys/signalvar.h>
88 #include <sys/resourcevar.h>
89 #include <sys/uidinfo.h>
90 #include <sys/event.h>
91 #include <sys/poll.h>
92 #include <sys/kauth.h>
93 #include <sys/mutex.h>
94 #include <sys/condvar.h>
95 #include <sys/kthread.h>
96 
97 #ifdef COMPAT_50
98 #include <compat/sys/time.h>
99 #include <compat/sys/socket.h>
100 #endif
101 
102 #include <uvm/uvm_extern.h>
103 #include <uvm/uvm_loan.h>
104 #include <uvm/uvm_page.h>
105 
106 MALLOC_DEFINE(M_SOOPTS, "soopts", "socket options");
107 MALLOC_DEFINE(M_SONAME, "soname", "socket name");
108 
109 extern const struct fileops socketops;
110 
111 extern int	somaxconn;			/* patchable (XXX sysctl) */
112 int		somaxconn = SOMAXCONN;
113 kmutex_t	*softnet_lock;
114 
115 #ifdef SOSEND_COUNTERS
116 #include <sys/device.h>
117 
118 static struct evcnt sosend_loan_big = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
119     NULL, "sosend", "loan big");
120 static struct evcnt sosend_copy_big = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
121     NULL, "sosend", "copy big");
122 static struct evcnt sosend_copy_small = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
123     NULL, "sosend", "copy small");
124 static struct evcnt sosend_kvalimit = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
125     NULL, "sosend", "kva limit");
126 
127 #define	SOSEND_COUNTER_INCR(ev)		(ev)->ev_count++
128 
129 EVCNT_ATTACH_STATIC(sosend_loan_big);
130 EVCNT_ATTACH_STATIC(sosend_copy_big);
131 EVCNT_ATTACH_STATIC(sosend_copy_small);
132 EVCNT_ATTACH_STATIC(sosend_kvalimit);
133 #else
134 
135 #define	SOSEND_COUNTER_INCR(ev)		/* nothing */
136 
137 #endif /* SOSEND_COUNTERS */
138 
139 #if defined(SOSEND_NO_LOAN) || defined(MULTIPROCESSOR)
140 int sock_loan_thresh = -1;
141 #else
142 int sock_loan_thresh = 4096;
143 #endif
144 
145 static kmutex_t so_pendfree_lock;
146 static struct mbuf *so_pendfree = NULL;
147 
148 #ifndef SOMAXKVA
149 #define	SOMAXKVA (16 * 1024 * 1024)
150 #endif
151 int somaxkva = SOMAXKVA;
152 static int socurkva;
153 static kcondvar_t socurkva_cv;
154 
155 static kauth_listener_t socket_listener;
156 
157 #define	SOCK_LOAN_CHUNK		65536
158 
159 static void sopendfree_thread(void *);
160 static kcondvar_t pendfree_thread_cv;
161 static lwp_t *sopendfree_lwp;
162 
163 static void sysctl_kern_socket_setup(void);
164 static struct sysctllog *socket_sysctllog;
165 
166 static vsize_t
167 sokvareserve(struct socket *so, vsize_t len)
168 {
169 	int error;
170 
171 	mutex_enter(&so_pendfree_lock);
172 	while (socurkva + len > somaxkva) {
173 		SOSEND_COUNTER_INCR(&sosend_kvalimit);
174 		error = cv_wait_sig(&socurkva_cv, &so_pendfree_lock);
175 		if (error) {
176 			len = 0;
177 			break;
178 		}
179 	}
180 	socurkva += len;
181 	mutex_exit(&so_pendfree_lock);
182 	return len;
183 }
184 
185 static void
186 sokvaunreserve(vsize_t len)
187 {
188 
189 	mutex_enter(&so_pendfree_lock);
190 	socurkva -= len;
191 	cv_broadcast(&socurkva_cv);
192 	mutex_exit(&so_pendfree_lock);
193 }
194 
195 /*
196  * sokvaalloc: allocate kva for loan.
197  */
198 
199 vaddr_t
200 sokvaalloc(vaddr_t sva, vsize_t len, struct socket *so)
201 {
202 	vaddr_t lva;
203 
204 	/*
205 	 * reserve kva.
206 	 */
207 
208 	if (sokvareserve(so, len) == 0)
209 		return 0;
210 
211 	/*
212 	 * allocate kva.
213 	 */
214 
215 	lva = uvm_km_alloc(kernel_map, len, atop(sva) & uvmexp.colormask,
216 	    UVM_KMF_COLORMATCH | UVM_KMF_VAONLY | UVM_KMF_WAITVA);
217 	if (lva == 0) {
218 		sokvaunreserve(len);
219 		return (0);
220 	}
221 
222 	return lva;
223 }
224 
225 /*
226  * sokvafree: free kva for loan.
227  */
228 
229 void
230 sokvafree(vaddr_t sva, vsize_t len)
231 {
232 
233 	/*
234 	 * free kva.
235 	 */
236 
237 	uvm_km_free(kernel_map, sva, len, UVM_KMF_VAONLY);
238 
239 	/*
240 	 * unreserve kva.
241 	 */
242 
243 	sokvaunreserve(len);
244 }
245 
246 static void
247 sodoloanfree(struct vm_page **pgs, void *buf, size_t size)
248 {
249 	vaddr_t sva, eva;
250 	vsize_t len;
251 	int npgs;
252 
253 	KASSERT(pgs != NULL);
254 
255 	eva = round_page((vaddr_t) buf + size);
256 	sva = trunc_page((vaddr_t) buf);
257 	len = eva - sva;
258 	npgs = len >> PAGE_SHIFT;
259 
260 	pmap_kremove(sva, len);
261 	pmap_update(pmap_kernel());
262 	uvm_unloan(pgs, npgs, UVM_LOAN_TOPAGE);
263 	sokvafree(sva, len);
264 }
265 
266 /*
267  * sopendfree_thread: free mbufs on "pendfree" list.
268  * unlock and relock so_pendfree_lock when freeing mbufs.
269  */
270 
271 static void
272 sopendfree_thread(void *v)
273 {
274 	struct mbuf *m, *next;
275 	size_t rv;
276 
277 	mutex_enter(&so_pendfree_lock);
278 
279 	for (;;) {
280 		rv = 0;
281 		while (so_pendfree != NULL) {
282 			m = so_pendfree;
283 			so_pendfree = NULL;
284 			mutex_exit(&so_pendfree_lock);
285 
286 			for (; m != NULL; m = next) {
287 				next = m->m_next;
288 				KASSERT((~m->m_flags & (M_EXT|M_EXT_PAGES)) == 0);
289 				KASSERT(m->m_ext.ext_refcnt == 0);
290 
291 				rv += m->m_ext.ext_size;
292 				sodoloanfree(m->m_ext.ext_pgs, m->m_ext.ext_buf,
293 				    m->m_ext.ext_size);
294 				pool_cache_put(mb_cache, m);
295 			}
296 
297 			mutex_enter(&so_pendfree_lock);
298 		}
299 		if (rv)
300 			cv_broadcast(&socurkva_cv);
301 		cv_wait(&pendfree_thread_cv, &so_pendfree_lock);
302 	}
303 	panic("sopendfree_thread");
304 	/* NOTREACHED */
305 }
306 
307 void
308 soloanfree(struct mbuf *m, void *buf, size_t size, void *arg)
309 {
310 
311 	KASSERT(m != NULL);
312 
313 	/*
314 	 * postpone freeing mbuf.
315 	 *
316 	 * we can't do it in interrupt context
317 	 * because we need to put kva back to kernel_map.
318 	 */
319 
320 	mutex_enter(&so_pendfree_lock);
321 	m->m_next = so_pendfree;
322 	so_pendfree = m;
323 	cv_signal(&pendfree_thread_cv);
324 	mutex_exit(&so_pendfree_lock);
325 }
326 
327 static long
328 sosend_loan(struct socket *so, struct uio *uio, struct mbuf *m, long space)
329 {
330 	struct iovec *iov = uio->uio_iov;
331 	vaddr_t sva, eva;
332 	vsize_t len;
333 	vaddr_t lva;
334 	int npgs, error;
335 	vaddr_t va;
336 	int i;
337 
338 	if (VMSPACE_IS_KERNEL_P(uio->uio_vmspace))
339 		return (0);
340 
341 	if (iov->iov_len < (size_t) space)
342 		space = iov->iov_len;
343 	if (space > SOCK_LOAN_CHUNK)
344 		space = SOCK_LOAN_CHUNK;
345 
346 	eva = round_page((vaddr_t) iov->iov_base + space);
347 	sva = trunc_page((vaddr_t) iov->iov_base);
348 	len = eva - sva;
349 	npgs = len >> PAGE_SHIFT;
350 
351 	KASSERT(npgs <= M_EXT_MAXPAGES);
352 
353 	lva = sokvaalloc(sva, len, so);
354 	if (lva == 0)
355 		return 0;
356 
357 	error = uvm_loan(&uio->uio_vmspace->vm_map, sva, len,
358 	    m->m_ext.ext_pgs, UVM_LOAN_TOPAGE);
359 	if (error) {
360 		sokvafree(lva, len);
361 		return (0);
362 	}
363 
364 	for (i = 0, va = lva; i < npgs; i++, va += PAGE_SIZE)
365 		pmap_kenter_pa(va, VM_PAGE_TO_PHYS(m->m_ext.ext_pgs[i]),
366 		    VM_PROT_READ, 0);
367 	pmap_update(pmap_kernel());
368 
369 	lva += (vaddr_t) iov->iov_base & PAGE_MASK;
370 
371 	MEXTADD(m, (void *) lva, space, M_MBUF, soloanfree, so);
372 	m->m_flags |= M_EXT_PAGES | M_EXT_ROMAP;
373 
374 	uio->uio_resid -= space;
375 	/* uio_offset not updated, not set/used for write(2) */
376 	uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + space;
377 	uio->uio_iov->iov_len -= space;
378 	if (uio->uio_iov->iov_len == 0) {
379 		uio->uio_iov++;
380 		uio->uio_iovcnt--;
381 	}
382 
383 	return (space);
384 }
385 
386 struct mbuf *
387 getsombuf(struct socket *so, int type)
388 {
389 	struct mbuf *m;
390 
391 	m = m_get(M_WAIT, type);
392 	MCLAIM(m, so->so_mowner);
393 	return m;
394 }
395 
396 static int
397 socket_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
398     void *arg0, void *arg1, void *arg2, void *arg3)
399 {
400 	int result;
401 	enum kauth_network_req req;
402 
403 	result = KAUTH_RESULT_DEFER;
404 	req = (enum kauth_network_req)arg0;
405 
406 	if ((action != KAUTH_NETWORK_SOCKET) &&
407 	    (action != KAUTH_NETWORK_BIND))
408 		return result;
409 
410 	switch (req) {
411 	case KAUTH_REQ_NETWORK_BIND_PORT:
412 		result = KAUTH_RESULT_ALLOW;
413 		break;
414 
415 	case KAUTH_REQ_NETWORK_SOCKET_DROP: {
416 		/* Normal users can only drop their own connections. */
417 		struct socket *so = (struct socket *)arg1;
418 
419 		if (proc_uidmatch(cred, so->so_cred))
420 			result = KAUTH_RESULT_ALLOW;
421 
422 		break;
423 		}
424 
425 	case KAUTH_REQ_NETWORK_SOCKET_OPEN:
426 		/* We allow "raw" routing/bluetooth sockets to anyone. */
427 		if ((u_long)arg1 == PF_ROUTE || (u_long)arg1 == PF_OROUTE
428 		    || (u_long)arg1 == PF_BLUETOOTH) {
429 			result = KAUTH_RESULT_ALLOW;
430 		} else {
431 			/* Privileged, let secmodel handle this. */
432 			if ((u_long)arg2 == SOCK_RAW)
433 				break;
434 		}
435 
436 		result = KAUTH_RESULT_ALLOW;
437 
438 		break;
439 
440 	case KAUTH_REQ_NETWORK_SOCKET_CANSEE:
441 		result = KAUTH_RESULT_ALLOW;
442 
443 		break;
444 
445 	default:
446 		break;
447 	}
448 
449 	return result;
450 }
451 
452 void
453 soinit(void)
454 {
455 
456 	sysctl_kern_socket_setup();
457 
458 	mutex_init(&so_pendfree_lock, MUTEX_DEFAULT, IPL_VM);
459 	softnet_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE);
460 	cv_init(&socurkva_cv, "sokva");
461 	cv_init(&pendfree_thread_cv, "sopendfr");
462 	soinit2();
463 
464 	/* Set the initial adjusted socket buffer size. */
465 	if (sb_max_set(sb_max))
466 		panic("bad initial sb_max value: %lu", sb_max);
467 
468 	socket_listener = kauth_listen_scope(KAUTH_SCOPE_NETWORK,
469 	    socket_listener_cb, NULL);
470 }
471 
472 void
473 soinit1(void)
474 {
475 	int error = kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL,
476 	    sopendfree_thread, NULL, &sopendfree_lwp, "sopendfree");
477 	if (error)
478 		panic("soinit1 %d", error);
479 }
480 
481 /*
482  * Socket operation routines.
483  * These routines are called by the routines in
484  * sys_socket.c or from a system process, and
485  * implement the semantics of socket operations by
486  * switching out to the protocol specific routines.
487  */
488 /*ARGSUSED*/
489 int
490 socreate(int dom, struct socket **aso, int type, int proto, struct lwp *l,
491 	 struct socket *lockso)
492 {
493 	const struct protosw	*prp;
494 	struct socket	*so;
495 	uid_t		uid;
496 	int		error;
497 	kmutex_t	*lock;
498 
499 	error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_SOCKET,
500 	    KAUTH_REQ_NETWORK_SOCKET_OPEN, KAUTH_ARG(dom), KAUTH_ARG(type),
501 	    KAUTH_ARG(proto));
502 	if (error != 0)
503 		return error;
504 
505 	if (proto)
506 		prp = pffindproto(dom, proto, type);
507 	else
508 		prp = pffindtype(dom, type);
509 	if (prp == NULL) {
510 		/* no support for domain */
511 		if (pffinddomain(dom) == 0)
512 			return EAFNOSUPPORT;
513 		/* no support for socket type */
514 		if (proto == 0 && type != 0)
515 			return EPROTOTYPE;
516 		return EPROTONOSUPPORT;
517 	}
518 	if (prp->pr_usrreq == NULL)
519 		return EPROTONOSUPPORT;
520 	if (prp->pr_type != type)
521 		return EPROTOTYPE;
522 
523 	so = soget(true);
524 	so->so_type = type;
525 	so->so_proto = prp;
526 	so->so_send = sosend;
527 	so->so_receive = soreceive;
528 #ifdef MBUFTRACE
529 	so->so_rcv.sb_mowner = &prp->pr_domain->dom_mowner;
530 	so->so_snd.sb_mowner = &prp->pr_domain->dom_mowner;
531 	so->so_mowner = &prp->pr_domain->dom_mowner;
532 #endif
533 	uid = kauth_cred_geteuid(l->l_cred);
534 	so->so_uidinfo = uid_find(uid);
535 	so->so_cpid = l->l_proc->p_pid;
536 	if (lockso != NULL) {
537 		/* Caller wants us to share a lock. */
538 		lock = lockso->so_lock;
539 		so->so_lock = lock;
540 		mutex_obj_hold(lock);
541 		mutex_enter(lock);
542 	} else {
543 		/* Lock assigned and taken during PRU_ATTACH. */
544 	}
545 	error = (*prp->pr_usrreq)(so, PRU_ATTACH, NULL,
546 	    (struct mbuf *)(long)proto, NULL, l);
547 	KASSERT(solocked(so));
548 	if (error != 0) {
549 		so->so_state |= SS_NOFDREF;
550 		sofree(so);
551 		return error;
552 	}
553 	so->so_cred = kauth_cred_dup(l->l_cred);
554 	sounlock(so);
555 	*aso = so;
556 	return 0;
557 }
558 
559 /* On success, write file descriptor to fdout and return zero.  On
560  * failure, return non-zero; *fdout will be undefined.
561  */
562 int
563 fsocreate(int domain, struct socket **sop, int type, int protocol,
564     struct lwp *l, int *fdout)
565 {
566 	struct socket	*so;
567 	struct file	*fp;
568 	int		fd, error;
569 	int		flags = type & SOCK_FLAGS_MASK;
570 
571 	type &= ~SOCK_FLAGS_MASK;
572 	if ((error = fd_allocfile(&fp, &fd)) != 0)
573 		return error;
574 	fd_set_exclose(l, fd, (flags & SOCK_CLOEXEC) != 0);
575 	fp->f_flag = FREAD|FWRITE|((flags & SOCK_NONBLOCK) ? FNONBLOCK : 0)|
576 	    ((flags & SOCK_NOSIGPIPE) ? FNOSIGPIPE : 0);
577 	fp->f_type = DTYPE_SOCKET;
578 	fp->f_ops = &socketops;
579 	error = socreate(domain, &so, type, protocol, l, NULL);
580 	if (error != 0) {
581 		fd_abort(curproc, fp, fd);
582 	} else {
583 		if (sop != NULL)
584 			*sop = so;
585 		fp->f_data = so;
586 		fd_affix(curproc, fp, fd);
587 		*fdout = fd;
588 		if (flags & SOCK_NONBLOCK)
589 			so->so_state |= SS_NBIO;
590 	}
591 	return error;
592 }
593 
594 int
595 sofamily(const struct socket *so)
596 {
597 	const struct protosw *pr;
598 	const struct domain *dom;
599 
600 	if ((pr = so->so_proto) == NULL)
601 		return AF_UNSPEC;
602 	if ((dom = pr->pr_domain) == NULL)
603 		return AF_UNSPEC;
604 	return dom->dom_family;
605 }
606 
607 int
608 sobind(struct socket *so, struct mbuf *nam, struct lwp *l)
609 {
610 	int	error;
611 
612 	solock(so);
613 	error = (*so->so_proto->pr_usrreq)(so, PRU_BIND, NULL, nam, NULL, l);
614 	sounlock(so);
615 	return error;
616 }
617 
618 int
619 solisten(struct socket *so, int backlog, struct lwp *l)
620 {
621 	int	error;
622 
623 	solock(so);
624 	if ((so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING |
625 	    SS_ISDISCONNECTING)) != 0) {
626 	    	sounlock(so);
627 		return (EINVAL);
628 	}
629 	error = (*so->so_proto->pr_usrreq)(so, PRU_LISTEN, NULL,
630 	    NULL, NULL, l);
631 	if (error != 0) {
632 		sounlock(so);
633 		return error;
634 	}
635 	if (TAILQ_EMPTY(&so->so_q))
636 		so->so_options |= SO_ACCEPTCONN;
637 	if (backlog < 0)
638 		backlog = 0;
639 	so->so_qlimit = min(backlog, somaxconn);
640 	sounlock(so);
641 	return 0;
642 }
643 
644 void
645 sofree(struct socket *so)
646 {
647 	u_int refs;
648 
649 	KASSERT(solocked(so));
650 
651 	if (so->so_pcb || (so->so_state & SS_NOFDREF) == 0) {
652 		sounlock(so);
653 		return;
654 	}
655 	if (so->so_head) {
656 		/*
657 		 * We must not decommission a socket that's on the accept(2)
658 		 * queue.  If we do, then accept(2) may hang after select(2)
659 		 * indicated that the listening socket was ready.
660 		 */
661 		if (!soqremque(so, 0)) {
662 			sounlock(so);
663 			return;
664 		}
665 	}
666 	if (so->so_rcv.sb_hiwat)
667 		(void)chgsbsize(so->so_uidinfo, &so->so_rcv.sb_hiwat, 0,
668 		    RLIM_INFINITY);
669 	if (so->so_snd.sb_hiwat)
670 		(void)chgsbsize(so->so_uidinfo, &so->so_snd.sb_hiwat, 0,
671 		    RLIM_INFINITY);
672 	sbrelease(&so->so_snd, so);
673 	KASSERT(!cv_has_waiters(&so->so_cv));
674 	KASSERT(!cv_has_waiters(&so->so_rcv.sb_cv));
675 	KASSERT(!cv_has_waiters(&so->so_snd.sb_cv));
676 	sorflush(so);
677 	refs = so->so_aborting;	/* XXX */
678 	/* Remove acccept filter if one is present. */
679 	if (so->so_accf != NULL)
680 		(void)accept_filt_clear(so);
681 	sounlock(so);
682 	if (refs == 0)		/* XXX */
683 		soput(so);
684 }
685 
686 /*
687  * Close a socket on last file table reference removal.
688  * Initiate disconnect if connected.
689  * Free socket when disconnect complete.
690  */
691 int
692 soclose(struct socket *so)
693 {
694 	struct socket	*so2;
695 	int		error;
696 	int		error2;
697 
698 	error = 0;
699 	solock(so);
700 	if (so->so_options & SO_ACCEPTCONN) {
701 		for (;;) {
702 			if ((so2 = TAILQ_FIRST(&so->so_q0)) != 0) {
703 				KASSERT(solocked2(so, so2));
704 				(void) soqremque(so2, 0);
705 				/* soabort drops the lock. */
706 				(void) soabort(so2);
707 				solock(so);
708 				continue;
709 			}
710 			if ((so2 = TAILQ_FIRST(&so->so_q)) != 0) {
711 				KASSERT(solocked2(so, so2));
712 				(void) soqremque(so2, 1);
713 				/* soabort drops the lock. */
714 				(void) soabort(so2);
715 				solock(so);
716 				continue;
717 			}
718 			break;
719 		}
720 	}
721 	if (so->so_pcb == 0)
722 		goto discard;
723 	if (so->so_state & SS_ISCONNECTED) {
724 		if ((so->so_state & SS_ISDISCONNECTING) == 0) {
725 			error = sodisconnect(so);
726 			if (error)
727 				goto drop;
728 		}
729 		if (so->so_options & SO_LINGER) {
730 			if ((so->so_state & (SS_ISDISCONNECTING|SS_NBIO)) ==
731 			    (SS_ISDISCONNECTING|SS_NBIO))
732 				goto drop;
733 			while (so->so_state & SS_ISCONNECTED) {
734 				error = sowait(so, true, so->so_linger * hz);
735 				if (error)
736 					break;
737 			}
738 		}
739 	}
740  drop:
741 	if (so->so_pcb) {
742 		error2 = (*so->so_proto->pr_usrreq)(so, PRU_DETACH,
743 		    NULL, NULL, NULL, NULL);
744 		if (error == 0)
745 			error = error2;
746 	}
747  discard:
748 	if (so->so_state & SS_NOFDREF)
749 		panic("soclose: NOFDREF");
750 	kauth_cred_free(so->so_cred);
751 	so->so_state |= SS_NOFDREF;
752 	sofree(so);
753 	return (error);
754 }
755 
756 /*
757  * Must be called with the socket locked..  Will return with it unlocked.
758  */
759 int
760 soabort(struct socket *so)
761 {
762 	u_int refs;
763 	int error;
764 
765 	KASSERT(solocked(so));
766 	KASSERT(so->so_head == NULL);
767 
768 	so->so_aborting++;		/* XXX */
769 	error = (*so->so_proto->pr_usrreq)(so, PRU_ABORT, NULL,
770 	    NULL, NULL, NULL);
771 	refs = --so->so_aborting;	/* XXX */
772 	if (error || (refs == 0)) {
773 		sofree(so);
774 	} else {
775 		sounlock(so);
776 	}
777 	return error;
778 }
779 
780 int
781 soaccept(struct socket *so, struct mbuf *nam)
782 {
783 	int	error;
784 
785 	KASSERT(solocked(so));
786 
787 	error = 0;
788 	if ((so->so_state & SS_NOFDREF) == 0)
789 		panic("soaccept: !NOFDREF");
790 	so->so_state &= ~SS_NOFDREF;
791 	if ((so->so_state & SS_ISDISCONNECTED) == 0 ||
792 	    (so->so_proto->pr_flags & PR_ABRTACPTDIS) == 0)
793 		error = (*so->so_proto->pr_usrreq)(so, PRU_ACCEPT,
794 		    NULL, nam, NULL, NULL);
795 	else
796 		error = ECONNABORTED;
797 
798 	return (error);
799 }
800 
801 int
802 soconnect(struct socket *so, struct mbuf *nam, struct lwp *l)
803 {
804 	int		error;
805 
806 	KASSERT(solocked(so));
807 
808 	if (so->so_options & SO_ACCEPTCONN)
809 		return (EOPNOTSUPP);
810 	/*
811 	 * If protocol is connection-based, can only connect once.
812 	 * Otherwise, if connected, try to disconnect first.
813 	 * This allows user to disconnect by connecting to, e.g.,
814 	 * a null address.
815 	 */
816 	if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
817 	    ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
818 	    (error = sodisconnect(so))))
819 		error = EISCONN;
820 	else
821 		error = (*so->so_proto->pr_usrreq)(so, PRU_CONNECT,
822 		    NULL, nam, NULL, l);
823 	return (error);
824 }
825 
826 int
827 soconnect2(struct socket *so1, struct socket *so2)
828 {
829 	int	error;
830 
831 	KASSERT(solocked2(so1, so2));
832 
833 	error = (*so1->so_proto->pr_usrreq)(so1, PRU_CONNECT2,
834 	    NULL, (struct mbuf *)so2, NULL, NULL);
835 	return (error);
836 }
837 
838 int
839 sodisconnect(struct socket *so)
840 {
841 	int	error;
842 
843 	KASSERT(solocked(so));
844 
845 	if ((so->so_state & SS_ISCONNECTED) == 0) {
846 		error = ENOTCONN;
847 	} else if (so->so_state & SS_ISDISCONNECTING) {
848 		error = EALREADY;
849 	} else {
850 		error = (*so->so_proto->pr_usrreq)(so, PRU_DISCONNECT,
851 		    NULL, NULL, NULL, NULL);
852 	}
853 	return (error);
854 }
855 
856 #define	SBLOCKWAIT(f)	(((f) & MSG_DONTWAIT) ? M_NOWAIT : M_WAITOK)
857 /*
858  * Send on a socket.
859  * If send must go all at once and message is larger than
860  * send buffering, then hard error.
861  * Lock against other senders.
862  * If must go all at once and not enough room now, then
863  * inform user that this would block and do nothing.
864  * Otherwise, if nonblocking, send as much as possible.
865  * The data to be sent is described by "uio" if nonzero,
866  * otherwise by the mbuf chain "top" (which must be null
867  * if uio is not).  Data provided in mbuf chain must be small
868  * enough to send all at once.
869  *
870  * Returns nonzero on error, timeout or signal; callers
871  * must check for short counts if EINTR/ERESTART are returned.
872  * Data and control buffers are freed on return.
873  */
874 int
875 sosend(struct socket *so, struct mbuf *addr, struct uio *uio, struct mbuf *top,
876 	struct mbuf *control, int flags, struct lwp *l)
877 {
878 	struct mbuf	**mp, *m;
879 	struct proc	*p;
880 	long		space, len, resid, clen, mlen;
881 	int		error, s, dontroute, atomic;
882 	short		wakeup_state = 0;
883 
884 	p = l->l_proc;
885 	clen = 0;
886 
887 	/*
888 	 * solock() provides atomicity of access.  splsoftnet() prevents
889 	 * protocol processing soft interrupts from interrupting us and
890 	 * blocking (expensive).
891 	 */
892 	s = splsoftnet();
893 	solock(so);
894 	atomic = sosendallatonce(so) || top;
895 	if (uio)
896 		resid = uio->uio_resid;
897 	else
898 		resid = top->m_pkthdr.len;
899 	/*
900 	 * In theory resid should be unsigned.
901 	 * However, space must be signed, as it might be less than 0
902 	 * if we over-committed, and we must use a signed comparison
903 	 * of space and resid.  On the other hand, a negative resid
904 	 * causes us to loop sending 0-length segments to the protocol.
905 	 */
906 	if (resid < 0) {
907 		error = EINVAL;
908 		goto out;
909 	}
910 	dontroute =
911 	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
912 	    (so->so_proto->pr_flags & PR_ATOMIC);
913 	l->l_ru.ru_msgsnd++;
914 	if (control)
915 		clen = control->m_len;
916  restart:
917 	if ((error = sblock(&so->so_snd, SBLOCKWAIT(flags))) != 0)
918 		goto out;
919 	do {
920 		if (so->so_state & SS_CANTSENDMORE) {
921 			error = EPIPE;
922 			goto release;
923 		}
924 		if (so->so_error) {
925 			error = so->so_error;
926 			so->so_error = 0;
927 			goto release;
928 		}
929 		if ((so->so_state & SS_ISCONNECTED) == 0) {
930 			if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
931 				if ((so->so_state & SS_ISCONFIRMING) == 0 &&
932 				    !(resid == 0 && clen != 0)) {
933 					error = ENOTCONN;
934 					goto release;
935 				}
936 			} else if (addr == 0) {
937 				error = EDESTADDRREQ;
938 				goto release;
939 			}
940 		}
941 		space = sbspace(&so->so_snd);
942 		if (flags & MSG_OOB)
943 			space += 1024;
944 		if ((atomic && resid > so->so_snd.sb_hiwat) ||
945 		    clen > so->so_snd.sb_hiwat) {
946 			error = EMSGSIZE;
947 			goto release;
948 		}
949 		if (space < resid + clen &&
950 		    (atomic || space < so->so_snd.sb_lowat || space < clen)) {
951 			if ((so->so_state & SS_NBIO) || (flags & MSG_NBIO)) {
952 				error = EWOULDBLOCK;
953 				goto release;
954 			}
955 			sbunlock(&so->so_snd);
956 			if (wakeup_state & SS_RESTARTSYS) {
957 				error = ERESTART;
958 				goto out;
959 			}
960 			error = sbwait(&so->so_snd);
961 			if (error)
962 				goto out;
963 			wakeup_state = so->so_state;
964 			goto restart;
965 		}
966 		wakeup_state = 0;
967 		mp = &top;
968 		space -= clen;
969 		do {
970 			if (uio == NULL) {
971 				/*
972 				 * Data is prepackaged in "top".
973 				 */
974 				resid = 0;
975 				if (flags & MSG_EOR)
976 					top->m_flags |= M_EOR;
977 			} else do {
978 				sounlock(so);
979 				splx(s);
980 				if (top == NULL) {
981 					m = m_gethdr(M_WAIT, MT_DATA);
982 					mlen = MHLEN;
983 					m->m_pkthdr.len = 0;
984 					m->m_pkthdr.rcvif = NULL;
985 				} else {
986 					m = m_get(M_WAIT, MT_DATA);
987 					mlen = MLEN;
988 				}
989 				MCLAIM(m, so->so_snd.sb_mowner);
990 				if (sock_loan_thresh >= 0 &&
991 				    uio->uio_iov->iov_len >= sock_loan_thresh &&
992 				    space >= sock_loan_thresh &&
993 				    (len = sosend_loan(so, uio, m,
994 						       space)) != 0) {
995 					SOSEND_COUNTER_INCR(&sosend_loan_big);
996 					space -= len;
997 					goto have_data;
998 				}
999 				if (resid >= MINCLSIZE && space >= MCLBYTES) {
1000 					SOSEND_COUNTER_INCR(&sosend_copy_big);
1001 					m_clget(m, M_DONTWAIT);
1002 					if ((m->m_flags & M_EXT) == 0)
1003 						goto nopages;
1004 					mlen = MCLBYTES;
1005 					if (atomic && top == 0) {
1006 						len = lmin(MCLBYTES - max_hdr,
1007 						    resid);
1008 						m->m_data += max_hdr;
1009 					} else
1010 						len = lmin(MCLBYTES, resid);
1011 					space -= len;
1012 				} else {
1013  nopages:
1014 					SOSEND_COUNTER_INCR(&sosend_copy_small);
1015 					len = lmin(lmin(mlen, resid), space);
1016 					space -= len;
1017 					/*
1018 					 * For datagram protocols, leave room
1019 					 * for protocol headers in first mbuf.
1020 					 */
1021 					if (atomic && top == 0 && len < mlen)
1022 						MH_ALIGN(m, len);
1023 				}
1024 				error = uiomove(mtod(m, void *), (int)len, uio);
1025  have_data:
1026 				resid = uio->uio_resid;
1027 				m->m_len = len;
1028 				*mp = m;
1029 				top->m_pkthdr.len += len;
1030 				s = splsoftnet();
1031 				solock(so);
1032 				if (error != 0)
1033 					goto release;
1034 				mp = &m->m_next;
1035 				if (resid <= 0) {
1036 					if (flags & MSG_EOR)
1037 						top->m_flags |= M_EOR;
1038 					break;
1039 				}
1040 			} while (space > 0 && atomic);
1041 
1042 			if (so->so_state & SS_CANTSENDMORE) {
1043 				error = EPIPE;
1044 				goto release;
1045 			}
1046 			if (dontroute)
1047 				so->so_options |= SO_DONTROUTE;
1048 			if (resid > 0)
1049 				so->so_state |= SS_MORETOCOME;
1050 			error = (*so->so_proto->pr_usrreq)(so,
1051 			    (flags & MSG_OOB) ? PRU_SENDOOB : PRU_SEND,
1052 			    top, addr, control, curlwp);
1053 			if (dontroute)
1054 				so->so_options &= ~SO_DONTROUTE;
1055 			if (resid > 0)
1056 				so->so_state &= ~SS_MORETOCOME;
1057 			clen = 0;
1058 			control = NULL;
1059 			top = NULL;
1060 			mp = &top;
1061 			if (error != 0)
1062 				goto release;
1063 		} while (resid && space > 0);
1064 	} while (resid);
1065 
1066  release:
1067 	sbunlock(&so->so_snd);
1068  out:
1069 	sounlock(so);
1070 	splx(s);
1071 	if (top)
1072 		m_freem(top);
1073 	if (control)
1074 		m_freem(control);
1075 	return (error);
1076 }
1077 
1078 /*
1079  * Following replacement or removal of the first mbuf on the first
1080  * mbuf chain of a socket buffer, push necessary state changes back
1081  * into the socket buffer so that other consumers see the values
1082  * consistently.  'nextrecord' is the callers locally stored value of
1083  * the original value of sb->sb_mb->m_nextpkt which must be restored
1084  * when the lead mbuf changes.  NOTE: 'nextrecord' may be NULL.
1085  */
1086 static void
1087 sbsync(struct sockbuf *sb, struct mbuf *nextrecord)
1088 {
1089 
1090 	KASSERT(solocked(sb->sb_so));
1091 
1092 	/*
1093 	 * First, update for the new value of nextrecord.  If necessary,
1094 	 * make it the first record.
1095 	 */
1096 	if (sb->sb_mb != NULL)
1097 		sb->sb_mb->m_nextpkt = nextrecord;
1098 	else
1099 		sb->sb_mb = nextrecord;
1100 
1101         /*
1102          * Now update any dependent socket buffer fields to reflect
1103          * the new state.  This is an inline of SB_EMPTY_FIXUP, with
1104          * the addition of a second clause that takes care of the
1105          * case where sb_mb has been updated, but remains the last
1106          * record.
1107          */
1108         if (sb->sb_mb == NULL) {
1109                 sb->sb_mbtail = NULL;
1110                 sb->sb_lastrecord = NULL;
1111         } else if (sb->sb_mb->m_nextpkt == NULL)
1112                 sb->sb_lastrecord = sb->sb_mb;
1113 }
1114 
1115 /*
1116  * Implement receive operations on a socket.
1117  * We depend on the way that records are added to the sockbuf
1118  * by sbappend*.  In particular, each record (mbufs linked through m_next)
1119  * must begin with an address if the protocol so specifies,
1120  * followed by an optional mbuf or mbufs containing ancillary data,
1121  * and then zero or more mbufs of data.
1122  * In order to avoid blocking network interrupts for the entire time here,
1123  * we splx() while doing the actual copy to user space.
1124  * Although the sockbuf is locked, new data may still be appended,
1125  * and thus we must maintain consistency of the sockbuf during that time.
1126  *
1127  * The caller may receive the data as a single mbuf chain by supplying
1128  * an mbuf **mp0 for use in returning the chain.  The uio is then used
1129  * only for the count in uio_resid.
1130  */
1131 int
1132 soreceive(struct socket *so, struct mbuf **paddr, struct uio *uio,
1133 	struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
1134 {
1135 	struct lwp *l = curlwp;
1136 	struct mbuf	*m, **mp, *mt;
1137 	size_t len, offset, moff, orig_resid;
1138 	int atomic, flags, error, s, type;
1139 	const struct protosw	*pr;
1140 	struct mbuf	*nextrecord;
1141 	int		mbuf_removed = 0;
1142 	const struct domain *dom;
1143 	short		wakeup_state = 0;
1144 
1145 	pr = so->so_proto;
1146 	atomic = pr->pr_flags & PR_ATOMIC;
1147 	dom = pr->pr_domain;
1148 	mp = mp0;
1149 	type = 0;
1150 	orig_resid = uio->uio_resid;
1151 
1152 	if (paddr != NULL)
1153 		*paddr = NULL;
1154 	if (controlp != NULL)
1155 		*controlp = NULL;
1156 	if (flagsp != NULL)
1157 		flags = *flagsp &~ MSG_EOR;
1158 	else
1159 		flags = 0;
1160 
1161 	if (flags & MSG_OOB) {
1162 		m = m_get(M_WAIT, MT_DATA);
1163 		solock(so);
1164 		error = (*pr->pr_usrreq)(so, PRU_RCVOOB, m,
1165 		    (struct mbuf *)(long)(flags & MSG_PEEK), NULL, l);
1166 		sounlock(so);
1167 		if (error)
1168 			goto bad;
1169 		do {
1170 			error = uiomove(mtod(m, void *),
1171 			    MIN(uio->uio_resid, m->m_len), uio);
1172 			m = m_free(m);
1173 		} while (uio->uio_resid > 0 && error == 0 && m);
1174  bad:
1175 		if (m != NULL)
1176 			m_freem(m);
1177 		return error;
1178 	}
1179 	if (mp != NULL)
1180 		*mp = NULL;
1181 
1182 	/*
1183 	 * solock() provides atomicity of access.  splsoftnet() prevents
1184 	 * protocol processing soft interrupts from interrupting us and
1185 	 * blocking (expensive).
1186 	 */
1187 	s = splsoftnet();
1188 	solock(so);
1189 	if (so->so_state & SS_ISCONFIRMING && uio->uio_resid)
1190 		(*pr->pr_usrreq)(so, PRU_RCVD, NULL, NULL, NULL, l);
1191 
1192  restart:
1193 	if ((error = sblock(&so->so_rcv, SBLOCKWAIT(flags))) != 0) {
1194 		sounlock(so);
1195 		splx(s);
1196 		return error;
1197 	}
1198 
1199 	m = so->so_rcv.sb_mb;
1200 	/*
1201 	 * If we have less data than requested, block awaiting more
1202 	 * (subject to any timeout) if:
1203 	 *   1. the current count is less than the low water mark,
1204 	 *   2. MSG_WAITALL is set, and it is possible to do the entire
1205 	 *	receive operation at once if we block (resid <= hiwat), or
1206 	 *   3. MSG_DONTWAIT is not set.
1207 	 * If MSG_WAITALL is set but resid is larger than the receive buffer,
1208 	 * we have to do the receive in sections, and thus risk returning
1209 	 * a short count if a timeout or signal occurs after we start.
1210 	 */
1211 	if (m == NULL ||
1212 	    ((flags & MSG_DONTWAIT) == 0 &&
1213 	     so->so_rcv.sb_cc < uio->uio_resid &&
1214 	     (so->so_rcv.sb_cc < so->so_rcv.sb_lowat ||
1215 	      ((flags & MSG_WAITALL) &&
1216 	       uio->uio_resid <= so->so_rcv.sb_hiwat)) &&
1217 	     m->m_nextpkt == NULL && !atomic)) {
1218 #ifdef DIAGNOSTIC
1219 		if (m == NULL && so->so_rcv.sb_cc)
1220 			panic("receive 1");
1221 #endif
1222 		if (so->so_error) {
1223 			if (m != NULL)
1224 				goto dontblock;
1225 			error = so->so_error;
1226 			if ((flags & MSG_PEEK) == 0)
1227 				so->so_error = 0;
1228 			goto release;
1229 		}
1230 		if (so->so_state & SS_CANTRCVMORE) {
1231 			if (m != NULL)
1232 				goto dontblock;
1233 			else
1234 				goto release;
1235 		}
1236 		for (; m != NULL; m = m->m_next)
1237 			if (m->m_type == MT_OOBDATA  || (m->m_flags & M_EOR)) {
1238 				m = so->so_rcv.sb_mb;
1239 				goto dontblock;
1240 			}
1241 		if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
1242 		    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
1243 			error = ENOTCONN;
1244 			goto release;
1245 		}
1246 		if (uio->uio_resid == 0)
1247 			goto release;
1248 		if ((so->so_state & SS_NBIO) ||
1249 		    (flags & (MSG_DONTWAIT|MSG_NBIO))) {
1250 			error = EWOULDBLOCK;
1251 			goto release;
1252 		}
1253 		SBLASTRECORDCHK(&so->so_rcv, "soreceive sbwait 1");
1254 		SBLASTMBUFCHK(&so->so_rcv, "soreceive sbwait 1");
1255 		sbunlock(&so->so_rcv);
1256 		if (wakeup_state & SS_RESTARTSYS)
1257 			error = ERESTART;
1258 		else
1259 			error = sbwait(&so->so_rcv);
1260 		if (error != 0) {
1261 			sounlock(so);
1262 			splx(s);
1263 			return error;
1264 		}
1265 		wakeup_state = so->so_state;
1266 		goto restart;
1267 	}
1268  dontblock:
1269 	/*
1270 	 * On entry here, m points to the first record of the socket buffer.
1271 	 * From this point onward, we maintain 'nextrecord' as a cache of the
1272 	 * pointer to the next record in the socket buffer.  We must keep the
1273 	 * various socket buffer pointers and local stack versions of the
1274 	 * pointers in sync, pushing out modifications before dropping the
1275 	 * socket lock, and re-reading them when picking it up.
1276 	 *
1277 	 * Otherwise, we will race with the network stack appending new data
1278 	 * or records onto the socket buffer by using inconsistent/stale
1279 	 * versions of the field, possibly resulting in socket buffer
1280 	 * corruption.
1281 	 *
1282 	 * By holding the high-level sblock(), we prevent simultaneous
1283 	 * readers from pulling off the front of the socket buffer.
1284 	 */
1285 	if (l != NULL)
1286 		l->l_ru.ru_msgrcv++;
1287 	KASSERT(m == so->so_rcv.sb_mb);
1288 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 1");
1289 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 1");
1290 	nextrecord = m->m_nextpkt;
1291 	if (pr->pr_flags & PR_ADDR) {
1292 #ifdef DIAGNOSTIC
1293 		if (m->m_type != MT_SONAME)
1294 			panic("receive 1a");
1295 #endif
1296 		orig_resid = 0;
1297 		if (flags & MSG_PEEK) {
1298 			if (paddr)
1299 				*paddr = m_copy(m, 0, m->m_len);
1300 			m = m->m_next;
1301 		} else {
1302 			sbfree(&so->so_rcv, m);
1303 			mbuf_removed = 1;
1304 			if (paddr != NULL) {
1305 				*paddr = m;
1306 				so->so_rcv.sb_mb = m->m_next;
1307 				m->m_next = NULL;
1308 				m = so->so_rcv.sb_mb;
1309 			} else {
1310 				MFREE(m, so->so_rcv.sb_mb);
1311 				m = so->so_rcv.sb_mb;
1312 			}
1313 			sbsync(&so->so_rcv, nextrecord);
1314 		}
1315 	}
1316 
1317 	/*
1318 	 * Process one or more MT_CONTROL mbufs present before any data mbufs
1319 	 * in the first mbuf chain on the socket buffer.  If MSG_PEEK, we
1320 	 * just copy the data; if !MSG_PEEK, we call into the protocol to
1321 	 * perform externalization (or freeing if controlp == NULL).
1322 	 */
1323 	if (__predict_false(m != NULL && m->m_type == MT_CONTROL)) {
1324 		struct mbuf *cm = NULL, *cmn;
1325 		struct mbuf **cme = &cm;
1326 
1327 		do {
1328 			if (flags & MSG_PEEK) {
1329 				if (controlp != NULL) {
1330 					*controlp = m_copy(m, 0, m->m_len);
1331 					controlp = &(*controlp)->m_next;
1332 				}
1333 				m = m->m_next;
1334 			} else {
1335 				sbfree(&so->so_rcv, m);
1336 				so->so_rcv.sb_mb = m->m_next;
1337 				m->m_next = NULL;
1338 				*cme = m;
1339 				cme = &(*cme)->m_next;
1340 				m = so->so_rcv.sb_mb;
1341 			}
1342 		} while (m != NULL && m->m_type == MT_CONTROL);
1343 		if ((flags & MSG_PEEK) == 0)
1344 			sbsync(&so->so_rcv, nextrecord);
1345 		for (; cm != NULL; cm = cmn) {
1346 			cmn = cm->m_next;
1347 			cm->m_next = NULL;
1348 			type = mtod(cm, struct cmsghdr *)->cmsg_type;
1349 			if (controlp != NULL) {
1350 				if (dom->dom_externalize != NULL &&
1351 				    type == SCM_RIGHTS) {
1352 					sounlock(so);
1353 					splx(s);
1354 					error = (*dom->dom_externalize)(cm, l,
1355 					    (flags & MSG_CMSG_CLOEXEC) ?
1356 					    O_CLOEXEC : 0);
1357 					s = splsoftnet();
1358 					solock(so);
1359 				}
1360 				*controlp = cm;
1361 				while (*controlp != NULL)
1362 					controlp = &(*controlp)->m_next;
1363 			} else {
1364 				/*
1365 				 * Dispose of any SCM_RIGHTS message that went
1366 				 * through the read path rather than recv.
1367 				 */
1368 				if (dom->dom_dispose != NULL &&
1369 				    type == SCM_RIGHTS) {
1370 				    	sounlock(so);
1371 					(*dom->dom_dispose)(cm);
1372 					solock(so);
1373 				}
1374 				m_freem(cm);
1375 			}
1376 		}
1377 		if (m != NULL)
1378 			nextrecord = so->so_rcv.sb_mb->m_nextpkt;
1379 		else
1380 			nextrecord = so->so_rcv.sb_mb;
1381 		orig_resid = 0;
1382 	}
1383 
1384 	/* If m is non-NULL, we have some data to read. */
1385 	if (__predict_true(m != NULL)) {
1386 		type = m->m_type;
1387 		if (type == MT_OOBDATA)
1388 			flags |= MSG_OOB;
1389 	}
1390 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 2");
1391 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 2");
1392 
1393 	moff = 0;
1394 	offset = 0;
1395 	while (m != NULL && uio->uio_resid > 0 && error == 0) {
1396 		if (m->m_type == MT_OOBDATA) {
1397 			if (type != MT_OOBDATA)
1398 				break;
1399 		} else if (type == MT_OOBDATA)
1400 			break;
1401 #ifdef DIAGNOSTIC
1402 		else if (m->m_type != MT_DATA && m->m_type != MT_HEADER)
1403 			panic("receive 3");
1404 #endif
1405 		so->so_state &= ~SS_RCVATMARK;
1406 		wakeup_state = 0;
1407 		len = uio->uio_resid;
1408 		if (so->so_oobmark && len > so->so_oobmark - offset)
1409 			len = so->so_oobmark - offset;
1410 		if (len > m->m_len - moff)
1411 			len = m->m_len - moff;
1412 		/*
1413 		 * If mp is set, just pass back the mbufs.
1414 		 * Otherwise copy them out via the uio, then free.
1415 		 * Sockbuf must be consistent here (points to current mbuf,
1416 		 * it points to next record) when we drop priority;
1417 		 * we must note any additions to the sockbuf when we
1418 		 * block interrupts again.
1419 		 */
1420 		if (mp == NULL) {
1421 			SBLASTRECORDCHK(&so->so_rcv, "soreceive uiomove");
1422 			SBLASTMBUFCHK(&so->so_rcv, "soreceive uiomove");
1423 			sounlock(so);
1424 			splx(s);
1425 			error = uiomove(mtod(m, char *) + moff, len, uio);
1426 			s = splsoftnet();
1427 			solock(so);
1428 			if (error != 0) {
1429 				/*
1430 				 * If any part of the record has been removed
1431 				 * (such as the MT_SONAME mbuf, which will
1432 				 * happen when PR_ADDR, and thus also
1433 				 * PR_ATOMIC, is set), then drop the entire
1434 				 * record to maintain the atomicity of the
1435 				 * receive operation.
1436 				 *
1437 				 * This avoids a later panic("receive 1a")
1438 				 * when compiled with DIAGNOSTIC.
1439 				 */
1440 				if (m && mbuf_removed && atomic)
1441 					(void) sbdroprecord(&so->so_rcv);
1442 
1443 				goto release;
1444 			}
1445 		} else
1446 			uio->uio_resid -= len;
1447 		if (len == m->m_len - moff) {
1448 			if (m->m_flags & M_EOR)
1449 				flags |= MSG_EOR;
1450 			if (flags & MSG_PEEK) {
1451 				m = m->m_next;
1452 				moff = 0;
1453 			} else {
1454 				nextrecord = m->m_nextpkt;
1455 				sbfree(&so->so_rcv, m);
1456 				if (mp) {
1457 					*mp = m;
1458 					mp = &m->m_next;
1459 					so->so_rcv.sb_mb = m = m->m_next;
1460 					*mp = NULL;
1461 				} else {
1462 					MFREE(m, so->so_rcv.sb_mb);
1463 					m = so->so_rcv.sb_mb;
1464 				}
1465 				/*
1466 				 * If m != NULL, we also know that
1467 				 * so->so_rcv.sb_mb != NULL.
1468 				 */
1469 				KASSERT(so->so_rcv.sb_mb == m);
1470 				if (m) {
1471 					m->m_nextpkt = nextrecord;
1472 					if (nextrecord == NULL)
1473 						so->so_rcv.sb_lastrecord = m;
1474 				} else {
1475 					so->so_rcv.sb_mb = nextrecord;
1476 					SB_EMPTY_FIXUP(&so->so_rcv);
1477 				}
1478 				SBLASTRECORDCHK(&so->so_rcv, "soreceive 3");
1479 				SBLASTMBUFCHK(&so->so_rcv, "soreceive 3");
1480 			}
1481 		} else if (flags & MSG_PEEK)
1482 			moff += len;
1483 		else {
1484 			if (mp != NULL) {
1485 				mt = m_copym(m, 0, len, M_NOWAIT);
1486 				if (__predict_false(mt == NULL)) {
1487 					sounlock(so);
1488 					mt = m_copym(m, 0, len, M_WAIT);
1489 					solock(so);
1490 				}
1491 				*mp = mt;
1492 			}
1493 			m->m_data += len;
1494 			m->m_len -= len;
1495 			so->so_rcv.sb_cc -= len;
1496 		}
1497 		if (so->so_oobmark) {
1498 			if ((flags & MSG_PEEK) == 0) {
1499 				so->so_oobmark -= len;
1500 				if (so->so_oobmark == 0) {
1501 					so->so_state |= SS_RCVATMARK;
1502 					break;
1503 				}
1504 			} else {
1505 				offset += len;
1506 				if (offset == so->so_oobmark)
1507 					break;
1508 			}
1509 		}
1510 		if (flags & MSG_EOR)
1511 			break;
1512 		/*
1513 		 * If the MSG_WAITALL flag is set (for non-atomic socket),
1514 		 * we must not quit until "uio->uio_resid == 0" or an error
1515 		 * termination.  If a signal/timeout occurs, return
1516 		 * with a short count but without error.
1517 		 * Keep sockbuf locked against other readers.
1518 		 */
1519 		while (flags & MSG_WAITALL && m == NULL && uio->uio_resid > 0 &&
1520 		    !sosendallatonce(so) && !nextrecord) {
1521 			if (so->so_error || so->so_state & SS_CANTRCVMORE)
1522 				break;
1523 			/*
1524 			 * If we are peeking and the socket receive buffer is
1525 			 * full, stop since we can't get more data to peek at.
1526 			 */
1527 			if ((flags & MSG_PEEK) && sbspace(&so->so_rcv) <= 0)
1528 				break;
1529 			/*
1530 			 * If we've drained the socket buffer, tell the
1531 			 * protocol in case it needs to do something to
1532 			 * get it filled again.
1533 			 */
1534 			if ((pr->pr_flags & PR_WANTRCVD) && so->so_pcb)
1535 				(*pr->pr_usrreq)(so, PRU_RCVD,
1536 				    NULL, (struct mbuf *)(long)flags, NULL, l);
1537 			SBLASTRECORDCHK(&so->so_rcv, "soreceive sbwait 2");
1538 			SBLASTMBUFCHK(&so->so_rcv, "soreceive sbwait 2");
1539 			if (wakeup_state & SS_RESTARTSYS)
1540 				error = ERESTART;
1541 			else
1542 				error = sbwait(&so->so_rcv);
1543 			if (error != 0) {
1544 				sbunlock(&so->so_rcv);
1545 				sounlock(so);
1546 				splx(s);
1547 				return 0;
1548 			}
1549 			if ((m = so->so_rcv.sb_mb) != NULL)
1550 				nextrecord = m->m_nextpkt;
1551 			wakeup_state = so->so_state;
1552 		}
1553 	}
1554 
1555 	if (m && atomic) {
1556 		flags |= MSG_TRUNC;
1557 		if ((flags & MSG_PEEK) == 0)
1558 			(void) sbdroprecord(&so->so_rcv);
1559 	}
1560 	if ((flags & MSG_PEEK) == 0) {
1561 		if (m == NULL) {
1562 			/*
1563 			 * First part is an inline SB_EMPTY_FIXUP().  Second
1564 			 * part makes sure sb_lastrecord is up-to-date if
1565 			 * there is still data in the socket buffer.
1566 			 */
1567 			so->so_rcv.sb_mb = nextrecord;
1568 			if (so->so_rcv.sb_mb == NULL) {
1569 				so->so_rcv.sb_mbtail = NULL;
1570 				so->so_rcv.sb_lastrecord = NULL;
1571 			} else if (nextrecord->m_nextpkt == NULL)
1572 				so->so_rcv.sb_lastrecord = nextrecord;
1573 		}
1574 		SBLASTRECORDCHK(&so->so_rcv, "soreceive 4");
1575 		SBLASTMBUFCHK(&so->so_rcv, "soreceive 4");
1576 		if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
1577 			(*pr->pr_usrreq)(so, PRU_RCVD, NULL,
1578 			    (struct mbuf *)(long)flags, NULL, l);
1579 	}
1580 	if (orig_resid == uio->uio_resid && orig_resid &&
1581 	    (flags & MSG_EOR) == 0 && (so->so_state & SS_CANTRCVMORE) == 0) {
1582 		sbunlock(&so->so_rcv);
1583 		goto restart;
1584 	}
1585 
1586 	if (flagsp != NULL)
1587 		*flagsp |= flags;
1588  release:
1589 	sbunlock(&so->so_rcv);
1590 	sounlock(so);
1591 	splx(s);
1592 	return error;
1593 }
1594 
1595 int
1596 soshutdown(struct socket *so, int how)
1597 {
1598 	const struct protosw	*pr;
1599 	int	error;
1600 
1601 	KASSERT(solocked(so));
1602 
1603 	pr = so->so_proto;
1604 	if (!(how == SHUT_RD || how == SHUT_WR || how == SHUT_RDWR))
1605 		return (EINVAL);
1606 
1607 	if (how == SHUT_RD || how == SHUT_RDWR) {
1608 		sorflush(so);
1609 		error = 0;
1610 	}
1611 	if (how == SHUT_WR || how == SHUT_RDWR)
1612 		error = (*pr->pr_usrreq)(so, PRU_SHUTDOWN, NULL,
1613 		    NULL, NULL, NULL);
1614 
1615 	return error;
1616 }
1617 
1618 void
1619 sorestart(struct socket *so)
1620 {
1621 	/*
1622 	 * An application has called close() on an fd on which another
1623 	 * of its threads has called a socket system call.
1624 	 * Mark this and wake everyone up, and code that would block again
1625 	 * instead returns ERESTART.
1626 	 * On system call re-entry the fd is validated and EBADF returned.
1627 	 * Any other fd will block again on the 2nd syscall.
1628 	 */
1629 	solock(so);
1630 	so->so_state |= SS_RESTARTSYS;
1631 	cv_broadcast(&so->so_cv);
1632 	cv_broadcast(&so->so_snd.sb_cv);
1633 	cv_broadcast(&so->so_rcv.sb_cv);
1634 	sounlock(so);
1635 }
1636 
1637 void
1638 sorflush(struct socket *so)
1639 {
1640 	struct sockbuf	*sb, asb;
1641 	const struct protosw	*pr;
1642 
1643 	KASSERT(solocked(so));
1644 
1645 	sb = &so->so_rcv;
1646 	pr = so->so_proto;
1647 	socantrcvmore(so);
1648 	sb->sb_flags |= SB_NOINTR;
1649 	(void )sblock(sb, M_WAITOK);
1650 	sbunlock(sb);
1651 	asb = *sb;
1652 	/*
1653 	 * Clear most of the sockbuf structure, but leave some of the
1654 	 * fields valid.
1655 	 */
1656 	memset(&sb->sb_startzero, 0,
1657 	    sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
1658 	if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose) {
1659 		sounlock(so);
1660 		(*pr->pr_domain->dom_dispose)(asb.sb_mb);
1661 		solock(so);
1662 	}
1663 	sbrelease(&asb, so);
1664 }
1665 
1666 /*
1667  * internal set SOL_SOCKET options
1668  */
1669 static int
1670 sosetopt1(struct socket *so, const struct sockopt *sopt)
1671 {
1672 	int error = EINVAL, optval, opt;
1673 	struct linger l;
1674 	struct timeval tv;
1675 
1676 	switch ((opt = sopt->sopt_name)) {
1677 
1678 	case SO_ACCEPTFILTER:
1679 		error = accept_filt_setopt(so, sopt);
1680 		KASSERT(solocked(so));
1681 		break;
1682 
1683   	case SO_LINGER:
1684  		error = sockopt_get(sopt, &l, sizeof(l));
1685 		solock(so);
1686  		if (error)
1687  			break;
1688  		if (l.l_linger < 0 || l.l_linger > USHRT_MAX ||
1689  		    l.l_linger > (INT_MAX / hz)) {
1690 			error = EDOM;
1691 			break;
1692 		}
1693  		so->so_linger = l.l_linger;
1694  		if (l.l_onoff)
1695  			so->so_options |= SO_LINGER;
1696  		else
1697  			so->so_options &= ~SO_LINGER;
1698    		break;
1699 
1700 	case SO_DEBUG:
1701 	case SO_KEEPALIVE:
1702 	case SO_DONTROUTE:
1703 	case SO_USELOOPBACK:
1704 	case SO_BROADCAST:
1705 	case SO_REUSEADDR:
1706 	case SO_REUSEPORT:
1707 	case SO_OOBINLINE:
1708 	case SO_TIMESTAMP:
1709 	case SO_NOSIGPIPE:
1710 #ifdef SO_OTIMESTAMP
1711 	case SO_OTIMESTAMP:
1712 #endif
1713 		error = sockopt_getint(sopt, &optval);
1714 		solock(so);
1715 		if (error)
1716 			break;
1717 		if (optval)
1718 			so->so_options |= opt;
1719 		else
1720 			so->so_options &= ~opt;
1721 		break;
1722 
1723 	case SO_SNDBUF:
1724 	case SO_RCVBUF:
1725 	case SO_SNDLOWAT:
1726 	case SO_RCVLOWAT:
1727 		error = sockopt_getint(sopt, &optval);
1728 		solock(so);
1729 		if (error)
1730 			break;
1731 
1732 		/*
1733 		 * Values < 1 make no sense for any of these
1734 		 * options, so disallow them.
1735 		 */
1736 		if (optval < 1) {
1737 			error = EINVAL;
1738 			break;
1739 		}
1740 
1741 		switch (opt) {
1742 		case SO_SNDBUF:
1743 			if (sbreserve(&so->so_snd, (u_long)optval, so) == 0) {
1744 				error = ENOBUFS;
1745 				break;
1746 			}
1747 			so->so_snd.sb_flags &= ~SB_AUTOSIZE;
1748 			break;
1749 
1750 		case SO_RCVBUF:
1751 			if (sbreserve(&so->so_rcv, (u_long)optval, so) == 0) {
1752 				error = ENOBUFS;
1753 				break;
1754 			}
1755 			so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
1756 			break;
1757 
1758 		/*
1759 		 * Make sure the low-water is never greater than
1760 		 * the high-water.
1761 		 */
1762 		case SO_SNDLOWAT:
1763 			if (optval > so->so_snd.sb_hiwat)
1764 				optval = so->so_snd.sb_hiwat;
1765 
1766 			so->so_snd.sb_lowat = optval;
1767 			break;
1768 
1769 		case SO_RCVLOWAT:
1770 			if (optval > so->so_rcv.sb_hiwat)
1771 				optval = so->so_rcv.sb_hiwat;
1772 
1773 			so->so_rcv.sb_lowat = optval;
1774 			break;
1775 		}
1776 		break;
1777 
1778 #ifdef COMPAT_50
1779 	case SO_OSNDTIMEO:
1780 	case SO_ORCVTIMEO: {
1781 		struct timeval50 otv;
1782 		error = sockopt_get(sopt, &otv, sizeof(otv));
1783 		if (error) {
1784 			solock(so);
1785 			break;
1786 		}
1787 		timeval50_to_timeval(&otv, &tv);
1788 		opt = opt == SO_OSNDTIMEO ? SO_SNDTIMEO : SO_RCVTIMEO;
1789 		error = 0;
1790 		/*FALLTHROUGH*/
1791 	}
1792 #endif /* COMPAT_50 */
1793 
1794 	case SO_SNDTIMEO:
1795 	case SO_RCVTIMEO:
1796 		if (error)
1797 			error = sockopt_get(sopt, &tv, sizeof(tv));
1798 		solock(so);
1799 		if (error)
1800 			break;
1801 
1802 		if (tv.tv_sec > (INT_MAX - tv.tv_usec / tick) / hz) {
1803 			error = EDOM;
1804 			break;
1805 		}
1806 
1807 		optval = tv.tv_sec * hz + tv.tv_usec / tick;
1808 		if (optval == 0 && tv.tv_usec != 0)
1809 			optval = 1;
1810 
1811 		switch (opt) {
1812 		case SO_SNDTIMEO:
1813 			so->so_snd.sb_timeo = optval;
1814 			break;
1815 		case SO_RCVTIMEO:
1816 			so->so_rcv.sb_timeo = optval;
1817 			break;
1818 		}
1819 		break;
1820 
1821 	default:
1822 		solock(so);
1823 		error = ENOPROTOOPT;
1824 		break;
1825 	}
1826 	KASSERT(solocked(so));
1827 	return error;
1828 }
1829 
1830 int
1831 sosetopt(struct socket *so, struct sockopt *sopt)
1832 {
1833 	int error, prerr;
1834 
1835 	if (sopt->sopt_level == SOL_SOCKET) {
1836 		error = sosetopt1(so, sopt);
1837 		KASSERT(solocked(so));
1838 	} else {
1839 		error = ENOPROTOOPT;
1840 		solock(so);
1841 	}
1842 
1843 	if ((error == 0 || error == ENOPROTOOPT) &&
1844 	    so->so_proto != NULL && so->so_proto->pr_ctloutput != NULL) {
1845 		/* give the protocol stack a shot */
1846 		prerr = (*so->so_proto->pr_ctloutput)(PRCO_SETOPT, so, sopt);
1847 		if (prerr == 0)
1848 			error = 0;
1849 		else if (prerr != ENOPROTOOPT)
1850 			error = prerr;
1851 	}
1852 	sounlock(so);
1853 	return error;
1854 }
1855 
1856 /*
1857  * so_setsockopt() is a wrapper providing a sockopt structure for sosetopt()
1858  */
1859 int
1860 so_setsockopt(struct lwp *l, struct socket *so, int level, int name,
1861     const void *val, size_t valsize)
1862 {
1863 	struct sockopt sopt;
1864 	int error;
1865 
1866 	KASSERT(valsize == 0 || val != NULL);
1867 
1868 	sockopt_init(&sopt, level, name, valsize);
1869 	sockopt_set(&sopt, val, valsize);
1870 
1871 	error = sosetopt(so, &sopt);
1872 
1873 	sockopt_destroy(&sopt);
1874 
1875 	return error;
1876 }
1877 
1878 /*
1879  * internal get SOL_SOCKET options
1880  */
1881 static int
1882 sogetopt1(struct socket *so, struct sockopt *sopt)
1883 {
1884 	int error, optval, opt;
1885 	struct linger l;
1886 	struct timeval tv;
1887 
1888 	switch ((opt = sopt->sopt_name)) {
1889 
1890 	case SO_ACCEPTFILTER:
1891 		error = accept_filt_getopt(so, sopt);
1892 		break;
1893 
1894 	case SO_LINGER:
1895 		l.l_onoff = (so->so_options & SO_LINGER) ? 1 : 0;
1896 		l.l_linger = so->so_linger;
1897 
1898 		error = sockopt_set(sopt, &l, sizeof(l));
1899 		break;
1900 
1901 	case SO_USELOOPBACK:
1902 	case SO_DONTROUTE:
1903 	case SO_DEBUG:
1904 	case SO_KEEPALIVE:
1905 	case SO_REUSEADDR:
1906 	case SO_REUSEPORT:
1907 	case SO_BROADCAST:
1908 	case SO_OOBINLINE:
1909 	case SO_TIMESTAMP:
1910 	case SO_NOSIGPIPE:
1911 #ifdef SO_OTIMESTAMP
1912 	case SO_OTIMESTAMP:
1913 #endif
1914 		error = sockopt_setint(sopt, (so->so_options & opt) ? 1 : 0);
1915 		break;
1916 
1917 	case SO_TYPE:
1918 		error = sockopt_setint(sopt, so->so_type);
1919 		break;
1920 
1921 	case SO_ERROR:
1922 		error = sockopt_setint(sopt, so->so_error);
1923 		so->so_error = 0;
1924 		break;
1925 
1926 	case SO_SNDBUF:
1927 		error = sockopt_setint(sopt, so->so_snd.sb_hiwat);
1928 		break;
1929 
1930 	case SO_RCVBUF:
1931 		error = sockopt_setint(sopt, so->so_rcv.sb_hiwat);
1932 		break;
1933 
1934 	case SO_SNDLOWAT:
1935 		error = sockopt_setint(sopt, so->so_snd.sb_lowat);
1936 		break;
1937 
1938 	case SO_RCVLOWAT:
1939 		error = sockopt_setint(sopt, so->so_rcv.sb_lowat);
1940 		break;
1941 
1942 #ifdef COMPAT_50
1943 	case SO_OSNDTIMEO:
1944 	case SO_ORCVTIMEO: {
1945 		struct timeval50 otv;
1946 
1947 		optval = (opt == SO_OSNDTIMEO ?
1948 		     so->so_snd.sb_timeo : so->so_rcv.sb_timeo);
1949 
1950 		otv.tv_sec = optval / hz;
1951 		otv.tv_usec = (optval % hz) * tick;
1952 
1953 		error = sockopt_set(sopt, &otv, sizeof(otv));
1954 		break;
1955 	}
1956 #endif /* COMPAT_50 */
1957 
1958 	case SO_SNDTIMEO:
1959 	case SO_RCVTIMEO:
1960 		optval = (opt == SO_SNDTIMEO ?
1961 		     so->so_snd.sb_timeo : so->so_rcv.sb_timeo);
1962 
1963 		tv.tv_sec = optval / hz;
1964 		tv.tv_usec = (optval % hz) * tick;
1965 
1966 		error = sockopt_set(sopt, &tv, sizeof(tv));
1967 		break;
1968 
1969 	case SO_OVERFLOWED:
1970 		error = sockopt_setint(sopt, so->so_rcv.sb_overflowed);
1971 		break;
1972 
1973 	default:
1974 		error = ENOPROTOOPT;
1975 		break;
1976 	}
1977 
1978 	return (error);
1979 }
1980 
1981 int
1982 sogetopt(struct socket *so, struct sockopt *sopt)
1983 {
1984 	int		error;
1985 
1986 	solock(so);
1987 	if (sopt->sopt_level != SOL_SOCKET) {
1988 		if (so->so_proto && so->so_proto->pr_ctloutput) {
1989 			error = ((*so->so_proto->pr_ctloutput)
1990 			    (PRCO_GETOPT, so, sopt));
1991 		} else
1992 			error = (ENOPROTOOPT);
1993 	} else {
1994 		error = sogetopt1(so, sopt);
1995 	}
1996 	sounlock(so);
1997 	return (error);
1998 }
1999 
2000 /*
2001  * alloc sockopt data buffer buffer
2002  *	- will be released at destroy
2003  */
2004 static int
2005 sockopt_alloc(struct sockopt *sopt, size_t len, km_flag_t kmflag)
2006 {
2007 
2008 	KASSERT(sopt->sopt_size == 0);
2009 
2010 	if (len > sizeof(sopt->sopt_buf)) {
2011 		sopt->sopt_data = kmem_zalloc(len, kmflag);
2012 		if (sopt->sopt_data == NULL)
2013 			return ENOMEM;
2014 	} else
2015 		sopt->sopt_data = sopt->sopt_buf;
2016 
2017 	sopt->sopt_size = len;
2018 	return 0;
2019 }
2020 
2021 /*
2022  * initialise sockopt storage
2023  *	- MAY sleep during allocation
2024  */
2025 void
2026 sockopt_init(struct sockopt *sopt, int level, int name, size_t size)
2027 {
2028 
2029 	memset(sopt, 0, sizeof(*sopt));
2030 
2031 	sopt->sopt_level = level;
2032 	sopt->sopt_name = name;
2033 	(void)sockopt_alloc(sopt, size, KM_SLEEP);
2034 }
2035 
2036 /*
2037  * destroy sockopt storage
2038  *	- will release any held memory references
2039  */
2040 void
2041 sockopt_destroy(struct sockopt *sopt)
2042 {
2043 
2044 	if (sopt->sopt_data != sopt->sopt_buf)
2045 		kmem_free(sopt->sopt_data, sopt->sopt_size);
2046 
2047 	memset(sopt, 0, sizeof(*sopt));
2048 }
2049 
2050 /*
2051  * set sockopt value
2052  *	- value is copied into sockopt
2053  * 	- memory is allocated when necessary, will not sleep
2054  */
2055 int
2056 sockopt_set(struct sockopt *sopt, const void *buf, size_t len)
2057 {
2058 	int error;
2059 
2060 	if (sopt->sopt_size == 0) {
2061 		error = sockopt_alloc(sopt, len, KM_NOSLEEP);
2062 		if (error)
2063 			return error;
2064 	}
2065 
2066 	KASSERT(sopt->sopt_size == len);
2067 	memcpy(sopt->sopt_data, buf, len);
2068 	return 0;
2069 }
2070 
2071 /*
2072  * common case of set sockopt integer value
2073  */
2074 int
2075 sockopt_setint(struct sockopt *sopt, int val)
2076 {
2077 
2078 	return sockopt_set(sopt, &val, sizeof(int));
2079 }
2080 
2081 /*
2082  * get sockopt value
2083  *	- correct size must be given
2084  */
2085 int
2086 sockopt_get(const struct sockopt *sopt, void *buf, size_t len)
2087 {
2088 
2089 	if (sopt->sopt_size != len)
2090 		return EINVAL;
2091 
2092 	memcpy(buf, sopt->sopt_data, len);
2093 	return 0;
2094 }
2095 
2096 /*
2097  * common case of get sockopt integer value
2098  */
2099 int
2100 sockopt_getint(const struct sockopt *sopt, int *valp)
2101 {
2102 
2103 	return sockopt_get(sopt, valp, sizeof(int));
2104 }
2105 
2106 /*
2107  * set sockopt value from mbuf
2108  *	- ONLY for legacy code
2109  *	- mbuf is released by sockopt
2110  *	- will not sleep
2111  */
2112 int
2113 sockopt_setmbuf(struct sockopt *sopt, struct mbuf *m)
2114 {
2115 	size_t len;
2116 	int error;
2117 
2118 	len = m_length(m);
2119 
2120 	if (sopt->sopt_size == 0) {
2121 		error = sockopt_alloc(sopt, len, KM_NOSLEEP);
2122 		if (error)
2123 			return error;
2124 	}
2125 
2126 	KASSERT(sopt->sopt_size == len);
2127 	m_copydata(m, 0, len, sopt->sopt_data);
2128 	m_freem(m);
2129 
2130 	return 0;
2131 }
2132 
2133 /*
2134  * get sockopt value into mbuf
2135  *	- ONLY for legacy code
2136  *	- mbuf to be released by the caller
2137  *	- will not sleep
2138  */
2139 struct mbuf *
2140 sockopt_getmbuf(const struct sockopt *sopt)
2141 {
2142 	struct mbuf *m;
2143 
2144 	if (sopt->sopt_size > MCLBYTES)
2145 		return NULL;
2146 
2147 	m = m_get(M_DONTWAIT, MT_SOOPTS);
2148 	if (m == NULL)
2149 		return NULL;
2150 
2151 	if (sopt->sopt_size > MLEN) {
2152 		MCLGET(m, M_DONTWAIT);
2153 		if ((m->m_flags & M_EXT) == 0) {
2154 			m_free(m);
2155 			return NULL;
2156 		}
2157 	}
2158 
2159 	memcpy(mtod(m, void *), sopt->sopt_data, sopt->sopt_size);
2160 	m->m_len = sopt->sopt_size;
2161 
2162 	return m;
2163 }
2164 
2165 void
2166 sohasoutofband(struct socket *so)
2167 {
2168 
2169 	fownsignal(so->so_pgid, SIGURG, POLL_PRI, POLLPRI|POLLRDBAND, so);
2170 	selnotify(&so->so_rcv.sb_sel, POLLPRI | POLLRDBAND, NOTE_SUBMIT);
2171 }
2172 
2173 static void
2174 filt_sordetach(struct knote *kn)
2175 {
2176 	struct socket	*so;
2177 
2178 	so = ((file_t *)kn->kn_obj)->f_data;
2179 	solock(so);
2180 	SLIST_REMOVE(&so->so_rcv.sb_sel.sel_klist, kn, knote, kn_selnext);
2181 	if (SLIST_EMPTY(&so->so_rcv.sb_sel.sel_klist))
2182 		so->so_rcv.sb_flags &= ~SB_KNOTE;
2183 	sounlock(so);
2184 }
2185 
2186 /*ARGSUSED*/
2187 static int
2188 filt_soread(struct knote *kn, long hint)
2189 {
2190 	struct socket	*so;
2191 	int rv;
2192 
2193 	so = ((file_t *)kn->kn_obj)->f_data;
2194 	if (hint != NOTE_SUBMIT)
2195 		solock(so);
2196 	kn->kn_data = so->so_rcv.sb_cc;
2197 	if (so->so_state & SS_CANTRCVMORE) {
2198 		kn->kn_flags |= EV_EOF;
2199 		kn->kn_fflags = so->so_error;
2200 		rv = 1;
2201 	} else if (so->so_error)	/* temporary udp error */
2202 		rv = 1;
2203 	else if (kn->kn_sfflags & NOTE_LOWAT)
2204 		rv = (kn->kn_data >= kn->kn_sdata);
2205 	else
2206 		rv = (kn->kn_data >= so->so_rcv.sb_lowat);
2207 	if (hint != NOTE_SUBMIT)
2208 		sounlock(so);
2209 	return rv;
2210 }
2211 
2212 static void
2213 filt_sowdetach(struct knote *kn)
2214 {
2215 	struct socket	*so;
2216 
2217 	so = ((file_t *)kn->kn_obj)->f_data;
2218 	solock(so);
2219 	SLIST_REMOVE(&so->so_snd.sb_sel.sel_klist, kn, knote, kn_selnext);
2220 	if (SLIST_EMPTY(&so->so_snd.sb_sel.sel_klist))
2221 		so->so_snd.sb_flags &= ~SB_KNOTE;
2222 	sounlock(so);
2223 }
2224 
2225 /*ARGSUSED*/
2226 static int
2227 filt_sowrite(struct knote *kn, long hint)
2228 {
2229 	struct socket	*so;
2230 	int rv;
2231 
2232 	so = ((file_t *)kn->kn_obj)->f_data;
2233 	if (hint != NOTE_SUBMIT)
2234 		solock(so);
2235 	kn->kn_data = sbspace(&so->so_snd);
2236 	if (so->so_state & SS_CANTSENDMORE) {
2237 		kn->kn_flags |= EV_EOF;
2238 		kn->kn_fflags = so->so_error;
2239 		rv = 1;
2240 	} else if (so->so_error)	/* temporary udp error */
2241 		rv = 1;
2242 	else if (((so->so_state & SS_ISCONNECTED) == 0) &&
2243 	    (so->so_proto->pr_flags & PR_CONNREQUIRED))
2244 		rv = 0;
2245 	else if (kn->kn_sfflags & NOTE_LOWAT)
2246 		rv = (kn->kn_data >= kn->kn_sdata);
2247 	else
2248 		rv = (kn->kn_data >= so->so_snd.sb_lowat);
2249 	if (hint != NOTE_SUBMIT)
2250 		sounlock(so);
2251 	return rv;
2252 }
2253 
2254 /*ARGSUSED*/
2255 static int
2256 filt_solisten(struct knote *kn, long hint)
2257 {
2258 	struct socket	*so;
2259 	int rv;
2260 
2261 	so = ((file_t *)kn->kn_obj)->f_data;
2262 
2263 	/*
2264 	 * Set kn_data to number of incoming connections, not
2265 	 * counting partial (incomplete) connections.
2266 	 */
2267 	if (hint != NOTE_SUBMIT)
2268 		solock(so);
2269 	kn->kn_data = so->so_qlen;
2270 	rv = (kn->kn_data > 0);
2271 	if (hint != NOTE_SUBMIT)
2272 		sounlock(so);
2273 	return rv;
2274 }
2275 
2276 static const struct filterops solisten_filtops =
2277 	{ 1, NULL, filt_sordetach, filt_solisten };
2278 static const struct filterops soread_filtops =
2279 	{ 1, NULL, filt_sordetach, filt_soread };
2280 static const struct filterops sowrite_filtops =
2281 	{ 1, NULL, filt_sowdetach, filt_sowrite };
2282 
2283 int
2284 soo_kqfilter(struct file *fp, struct knote *kn)
2285 {
2286 	struct socket	*so;
2287 	struct sockbuf	*sb;
2288 
2289 	so = ((file_t *)kn->kn_obj)->f_data;
2290 	solock(so);
2291 	switch (kn->kn_filter) {
2292 	case EVFILT_READ:
2293 		if (so->so_options & SO_ACCEPTCONN)
2294 			kn->kn_fop = &solisten_filtops;
2295 		else
2296 			kn->kn_fop = &soread_filtops;
2297 		sb = &so->so_rcv;
2298 		break;
2299 	case EVFILT_WRITE:
2300 		kn->kn_fop = &sowrite_filtops;
2301 		sb = &so->so_snd;
2302 		break;
2303 	default:
2304 		sounlock(so);
2305 		return (EINVAL);
2306 	}
2307 	SLIST_INSERT_HEAD(&sb->sb_sel.sel_klist, kn, kn_selnext);
2308 	sb->sb_flags |= SB_KNOTE;
2309 	sounlock(so);
2310 	return (0);
2311 }
2312 
2313 static int
2314 sodopoll(struct socket *so, int events)
2315 {
2316 	int revents;
2317 
2318 	revents = 0;
2319 
2320 	if (events & (POLLIN | POLLRDNORM))
2321 		if (soreadable(so))
2322 			revents |= events & (POLLIN | POLLRDNORM);
2323 
2324 	if (events & (POLLOUT | POLLWRNORM))
2325 		if (sowritable(so))
2326 			revents |= events & (POLLOUT | POLLWRNORM);
2327 
2328 	if (events & (POLLPRI | POLLRDBAND))
2329 		if (so->so_oobmark || (so->so_state & SS_RCVATMARK))
2330 			revents |= events & (POLLPRI | POLLRDBAND);
2331 
2332 	return revents;
2333 }
2334 
2335 int
2336 sopoll(struct socket *so, int events)
2337 {
2338 	int revents = 0;
2339 
2340 #ifndef DIAGNOSTIC
2341 	/*
2342 	 * Do a quick, unlocked check in expectation that the socket
2343 	 * will be ready for I/O.  Don't do this check if DIAGNOSTIC,
2344 	 * as the solocked() assertions will fail.
2345 	 */
2346 	if ((revents = sodopoll(so, events)) != 0)
2347 		return revents;
2348 #endif
2349 
2350 	solock(so);
2351 	if ((revents = sodopoll(so, events)) == 0) {
2352 		if (events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) {
2353 			selrecord(curlwp, &so->so_rcv.sb_sel);
2354 			so->so_rcv.sb_flags |= SB_NOTIFY;
2355 		}
2356 
2357 		if (events & (POLLOUT | POLLWRNORM)) {
2358 			selrecord(curlwp, &so->so_snd.sb_sel);
2359 			so->so_snd.sb_flags |= SB_NOTIFY;
2360 		}
2361 	}
2362 	sounlock(so);
2363 
2364 	return revents;
2365 }
2366 
2367 
2368 #include <sys/sysctl.h>
2369 
2370 static int sysctl_kern_somaxkva(SYSCTLFN_PROTO);
2371 static int sysctl_kern_sbmax(SYSCTLFN_PROTO);
2372 
2373 /*
2374  * sysctl helper routine for kern.somaxkva.  ensures that the given
2375  * value is not too small.
2376  * (XXX should we maybe make sure it's not too large as well?)
2377  */
2378 static int
2379 sysctl_kern_somaxkva(SYSCTLFN_ARGS)
2380 {
2381 	int error, new_somaxkva;
2382 	struct sysctlnode node;
2383 
2384 	new_somaxkva = somaxkva;
2385 	node = *rnode;
2386 	node.sysctl_data = &new_somaxkva;
2387 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
2388 	if (error || newp == NULL)
2389 		return (error);
2390 
2391 	if (new_somaxkva < (16 * 1024 * 1024)) /* sanity */
2392 		return (EINVAL);
2393 
2394 	mutex_enter(&so_pendfree_lock);
2395 	somaxkva = new_somaxkva;
2396 	cv_broadcast(&socurkva_cv);
2397 	mutex_exit(&so_pendfree_lock);
2398 
2399 	return (error);
2400 }
2401 
2402 /*
2403  * sysctl helper routine for kern.sbmax. Basically just ensures that
2404  * any new value is not too small.
2405  */
2406 static int
2407 sysctl_kern_sbmax(SYSCTLFN_ARGS)
2408 {
2409 	int error, new_sbmax;
2410 	struct sysctlnode node;
2411 
2412 	new_sbmax = sb_max;
2413 	node = *rnode;
2414 	node.sysctl_data = &new_sbmax;
2415 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
2416 	if (error || newp == NULL)
2417 		return (error);
2418 
2419 	KERNEL_LOCK(1, NULL);
2420 	error = sb_max_set(new_sbmax);
2421 	KERNEL_UNLOCK_ONE(NULL);
2422 
2423 	return (error);
2424 }
2425 
2426 static void
2427 sysctl_kern_socket_setup(void)
2428 {
2429 
2430 	KASSERT(socket_sysctllog == NULL);
2431 	sysctl_createv(&socket_sysctllog, 0, NULL, NULL,
2432 		       CTLFLAG_PERMANENT,
2433 		       CTLTYPE_NODE, "kern", NULL,
2434 		       NULL, 0, NULL, 0,
2435 		       CTL_KERN, CTL_EOL);
2436 
2437 	sysctl_createv(&socket_sysctllog, 0, NULL, NULL,
2438 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2439 		       CTLTYPE_INT, "somaxkva",
2440 		       SYSCTL_DESCR("Maximum amount of kernel memory to be "
2441 				    "used for socket buffers"),
2442 		       sysctl_kern_somaxkva, 0, NULL, 0,
2443 		       CTL_KERN, KERN_SOMAXKVA, CTL_EOL);
2444 
2445 	sysctl_createv(&socket_sysctllog, 0, NULL, NULL,
2446 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
2447 		       CTLTYPE_INT, "sbmax",
2448 		       SYSCTL_DESCR("Maximum socket buffer size"),
2449 		       sysctl_kern_sbmax, 0, NULL, 0,
2450 		       CTL_KERN, KERN_SBMAX, CTL_EOL);
2451 }
2452