Home | History | Annotate | Line # | Download | only in kern
uipc_socket.c revision 1.296
      1 /*	$NetBSD: uipc_socket.c,v 1.296 2021/09/26 01:16:10 thorpej 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 /*
     66  * Socket operation routines.
     67  *
     68  * These routines are called by the routines in sys_socket.c or from a
     69  * system process, and implement the semantics of socket operations by
     70  * switching out to the protocol specific routines.
     71  */
     72 
     73 #include <sys/cdefs.h>
     74 __KERNEL_RCSID(0, "$NetBSD: uipc_socket.c,v 1.296 2021/09/26 01:16:10 thorpej Exp $");
     75 
     76 #ifdef _KERNEL_OPT
     77 #include "opt_compat_netbsd.h"
     78 #include "opt_sock_counters.h"
     79 #include "opt_sosend_loan.h"
     80 #include "opt_mbuftrace.h"
     81 #include "opt_somaxkva.h"
     82 #include "opt_multiprocessor.h"	/* XXX */
     83 #include "opt_sctp.h"
     84 #endif
     85 
     86 #include <sys/param.h>
     87 #include <sys/systm.h>
     88 #include <sys/proc.h>
     89 #include <sys/file.h>
     90 #include <sys/filedesc.h>
     91 #include <sys/kmem.h>
     92 #include <sys/mbuf.h>
     93 #include <sys/domain.h>
     94 #include <sys/kernel.h>
     95 #include <sys/protosw.h>
     96 #include <sys/socket.h>
     97 #include <sys/socketvar.h>
     98 #include <sys/signalvar.h>
     99 #include <sys/resourcevar.h>
    100 #include <sys/uidinfo.h>
    101 #include <sys/event.h>
    102 #include <sys/poll.h>
    103 #include <sys/kauth.h>
    104 #include <sys/mutex.h>
    105 #include <sys/condvar.h>
    106 #include <sys/kthread.h>
    107 #include <sys/compat_stub.h>
    108 
    109 #include <compat/sys/time.h>
    110 #include <compat/sys/socket.h>
    111 
    112 #include <uvm/uvm_extern.h>
    113 #include <uvm/uvm_loan.h>
    114 #include <uvm/uvm_page.h>
    115 
    116 #ifdef SCTP
    117 #include <netinet/sctp_route.h>
    118 #endif
    119 
    120 MALLOC_DEFINE(M_SONAME, "soname", "socket name");
    121 
    122 extern const struct fileops socketops;
    123 
    124 static int	sooptions;
    125 extern int	somaxconn;			/* patchable (XXX sysctl) */
    126 int		somaxconn = SOMAXCONN;
    127 kmutex_t	*softnet_lock;
    128 
    129 #ifdef SOSEND_COUNTERS
    130 #include <sys/device.h>
    131 
    132 static struct evcnt sosend_loan_big = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
    133     NULL, "sosend", "loan big");
    134 static struct evcnt sosend_copy_big = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
    135     NULL, "sosend", "copy big");
    136 static struct evcnt sosend_copy_small = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
    137     NULL, "sosend", "copy small");
    138 static struct evcnt sosend_kvalimit = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
    139     NULL, "sosend", "kva limit");
    140 
    141 #define	SOSEND_COUNTER_INCR(ev)		(ev)->ev_count++
    142 
    143 EVCNT_ATTACH_STATIC(sosend_loan_big);
    144 EVCNT_ATTACH_STATIC(sosend_copy_big);
    145 EVCNT_ATTACH_STATIC(sosend_copy_small);
    146 EVCNT_ATTACH_STATIC(sosend_kvalimit);
    147 #else
    148 
    149 #define	SOSEND_COUNTER_INCR(ev)		/* nothing */
    150 
    151 #endif /* SOSEND_COUNTERS */
    152 
    153 #if defined(SOSEND_NO_LOAN) || defined(MULTIPROCESSOR)
    154 int sock_loan_thresh = -1;
    155 #else
    156 int sock_loan_thresh = 4096;
    157 #endif
    158 
    159 static kmutex_t so_pendfree_lock;
    160 static struct mbuf *so_pendfree = NULL;
    161 
    162 #ifndef SOMAXKVA
    163 #define	SOMAXKVA (16 * 1024 * 1024)
    164 #endif
    165 int somaxkva = SOMAXKVA;
    166 static int socurkva;
    167 static kcondvar_t socurkva_cv;
    168 
    169 #ifndef SOFIXEDBUF
    170 #define SOFIXEDBUF true
    171 #endif
    172 bool sofixedbuf = SOFIXEDBUF;
    173 
    174 static kauth_listener_t socket_listener;
    175 
    176 #define	SOCK_LOAN_CHUNK		65536
    177 
    178 static void sopendfree_thread(void *);
    179 static kcondvar_t pendfree_thread_cv;
    180 static lwp_t *sopendfree_lwp;
    181 
    182 static void sysctl_kern_socket_setup(void);
    183 static struct sysctllog *socket_sysctllog;
    184 
    185 static vsize_t
    186 sokvareserve(struct socket *so, vsize_t len)
    187 {
    188 	int error;
    189 
    190 	mutex_enter(&so_pendfree_lock);
    191 	while (socurkva + len > somaxkva) {
    192 		SOSEND_COUNTER_INCR(&sosend_kvalimit);
    193 		error = cv_wait_sig(&socurkva_cv, &so_pendfree_lock);
    194 		if (error) {
    195 			len = 0;
    196 			break;
    197 		}
    198 	}
    199 	socurkva += len;
    200 	mutex_exit(&so_pendfree_lock);
    201 	return len;
    202 }
    203 
    204 static void
    205 sokvaunreserve(vsize_t len)
    206 {
    207 
    208 	mutex_enter(&so_pendfree_lock);
    209 	socurkva -= len;
    210 	cv_broadcast(&socurkva_cv);
    211 	mutex_exit(&so_pendfree_lock);
    212 }
    213 
    214 /*
    215  * sokvaalloc: allocate kva for loan.
    216  */
    217 vaddr_t
    218 sokvaalloc(vaddr_t sva, vsize_t len, struct socket *so)
    219 {
    220 	vaddr_t lva;
    221 
    222 	if (sokvareserve(so, len) == 0)
    223 		return 0;
    224 
    225 	lva = uvm_km_alloc(kernel_map, len, atop(sva) & uvmexp.colormask,
    226 	    UVM_KMF_COLORMATCH | UVM_KMF_VAONLY | UVM_KMF_WAITVA);
    227 	if (lva == 0) {
    228 		sokvaunreserve(len);
    229 		return 0;
    230 	}
    231 
    232 	return lva;
    233 }
    234 
    235 /*
    236  * sokvafree: free kva for loan.
    237  */
    238 void
    239 sokvafree(vaddr_t sva, vsize_t len)
    240 {
    241 
    242 	uvm_km_free(kernel_map, sva, len, UVM_KMF_VAONLY);
    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. Unlock and relock
    268  * so_pendfree_lock when freeing mbufs.
    269  */
    270 static void
    271 sopendfree_thread(void *v)
    272 {
    273 	struct mbuf *m, *next;
    274 	size_t rv;
    275 
    276 	mutex_enter(&so_pendfree_lock);
    277 
    278 	for (;;) {
    279 		rv = 0;
    280 		while (so_pendfree != NULL) {
    281 			m = so_pendfree;
    282 			so_pendfree = NULL;
    283 			mutex_exit(&so_pendfree_lock);
    284 
    285 			for (; m != NULL; m = next) {
    286 				next = m->m_next;
    287 				KASSERT((~m->m_flags & (M_EXT|M_EXT_PAGES)) ==
    288 				    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 static int
    387 socket_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
    388     void *arg0, void *arg1, void *arg2, void *arg3)
    389 {
    390 	int result;
    391 	enum kauth_network_req req;
    392 
    393 	result = KAUTH_RESULT_DEFER;
    394 	req = (enum kauth_network_req)(uintptr_t)arg0;
    395 
    396 	if ((action != KAUTH_NETWORK_SOCKET) &&
    397 	    (action != KAUTH_NETWORK_BIND))
    398 		return result;
    399 
    400 	switch (req) {
    401 	case KAUTH_REQ_NETWORK_BIND_PORT:
    402 		result = KAUTH_RESULT_ALLOW;
    403 		break;
    404 
    405 	case KAUTH_REQ_NETWORK_SOCKET_DROP: {
    406 		/* Normal users can only drop their own connections. */
    407 		struct socket *so = (struct socket *)arg1;
    408 
    409 		if (so->so_cred && proc_uidmatch(cred, so->so_cred) == 0)
    410 			result = KAUTH_RESULT_ALLOW;
    411 
    412 		break;
    413 		}
    414 
    415 	case KAUTH_REQ_NETWORK_SOCKET_OPEN:
    416 		/* We allow "raw" routing/bluetooth sockets to anyone. */
    417 		switch ((u_long)arg1) {
    418 		case PF_ROUTE:
    419 		case PF_OROUTE:
    420 		case PF_BLUETOOTH:
    421 		case PF_CAN:
    422 			result = KAUTH_RESULT_ALLOW;
    423 			break;
    424 		default:
    425 			/* Privileged, let secmodel handle this. */
    426 			if ((u_long)arg2 == SOCK_RAW)
    427 				break;
    428 			result = KAUTH_RESULT_ALLOW;
    429 			break;
    430 		}
    431 		break;
    432 
    433 	case KAUTH_REQ_NETWORK_SOCKET_CANSEE:
    434 		result = KAUTH_RESULT_ALLOW;
    435 
    436 		break;
    437 
    438 	default:
    439 		break;
    440 	}
    441 
    442 	return result;
    443 }
    444 
    445 void
    446 soinit(void)
    447 {
    448 
    449 	sysctl_kern_socket_setup();
    450 
    451 #ifdef SCTP
    452 	/* Update the SCTP function hooks if necessary*/
    453 
    454         vec_sctp_add_ip_address = sctp_add_ip_address;
    455         vec_sctp_delete_ip_address = sctp_delete_ip_address;
    456 #endif
    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  * socreate: create a new socket of the specified type and the protocol.
    483  *
    484  * => Caller may specify another socket for lock sharing (must not be held).
    485  * => Returns the new socket without lock held.
    486  */
    487 int
    488 socreate(int dom, struct socket **aso, int type, int proto, struct lwp *l,
    489     struct socket *lockso)
    490 {
    491 	const struct protosw *prp;
    492 	struct socket *so;
    493 	uid_t uid;
    494 	int error;
    495 	kmutex_t *lock;
    496 
    497 	error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_SOCKET,
    498 	    KAUTH_REQ_NETWORK_SOCKET_OPEN, KAUTH_ARG(dom), KAUTH_ARG(type),
    499 	    KAUTH_ARG(proto));
    500 	if (error != 0)
    501 		return error;
    502 
    503 	if (proto)
    504 		prp = pffindproto(dom, proto, type);
    505 	else
    506 		prp = pffindtype(dom, type);
    507 	if (prp == NULL) {
    508 		/* no support for domain */
    509 		if (pffinddomain(dom) == 0)
    510 			return EAFNOSUPPORT;
    511 		/* no support for socket type */
    512 		if (proto == 0 && type != 0)
    513 			return EPROTOTYPE;
    514 		return EPROTONOSUPPORT;
    515 	}
    516 	if (prp->pr_usrreqs == NULL)
    517 		return EPROTONOSUPPORT;
    518 	if (prp->pr_type != type)
    519 		return EPROTOTYPE;
    520 
    521 	so = soget(true);
    522 	so->so_type = type;
    523 	so->so_proto = prp;
    524 	so->so_send = sosend;
    525 	so->so_receive = soreceive;
    526 	so->so_options = sooptions;
    527 #ifdef MBUFTRACE
    528 	so->so_rcv.sb_mowner = &prp->pr_domain->dom_mowner;
    529 	so->so_snd.sb_mowner = &prp->pr_domain->dom_mowner;
    530 	so->so_mowner = &prp->pr_domain->dom_mowner;
    531 #endif
    532 	uid = kauth_cred_geteuid(l->l_cred);
    533 	so->so_uidinfo = uid_find(uid);
    534 	so->so_egid = kauth_cred_getegid(l->l_cred);
    535 	so->so_cpid = l->l_proc->p_pid;
    536 
    537 	/*
    538 	 * Lock assigned and taken during PCB attach, unless we share
    539 	 * the lock with another socket, e.g. socketpair(2) case.
    540 	 */
    541 	if (lockso) {
    542 		lock = lockso->so_lock;
    543 		so->so_lock = lock;
    544 		mutex_obj_hold(lock);
    545 		mutex_enter(lock);
    546 	}
    547 
    548 	/* Attach the PCB (returns with the socket lock held). */
    549 	error = (*prp->pr_usrreqs->pr_attach)(so, proto);
    550 	KASSERT(solocked(so));
    551 
    552 	if (error) {
    553 		KASSERT(so->so_pcb == NULL);
    554 		so->so_state |= SS_NOFDREF;
    555 		sofree(so);
    556 		return error;
    557 	}
    558 	so->so_cred = kauth_cred_dup(l->l_cred);
    559 	sounlock(so);
    560 
    561 	*aso = so;
    562 	return 0;
    563 }
    564 
    565 /*
    566  * fsocreate: create a socket and a file descriptor associated with it.
    567  *
    568  * => On success, write file descriptor to fdout and return zero.
    569  * => On failure, return non-zero; *fdout will be undefined.
    570  */
    571 int
    572 fsocreate(int domain, struct socket **sop, int type, int proto, int *fdout)
    573 {
    574 	lwp_t *l = curlwp;
    575 	int error, fd, flags;
    576 	struct socket *so;
    577 	struct file *fp;
    578 
    579 	if ((error = fd_allocfile(&fp, &fd)) != 0) {
    580 		return error;
    581 	}
    582 	flags = type & SOCK_FLAGS_MASK;
    583 	fd_set_exclose(l, fd, (flags & SOCK_CLOEXEC) != 0);
    584 	fp->f_flag = FREAD|FWRITE|((flags & SOCK_NONBLOCK) ? FNONBLOCK : 0)|
    585 	    ((flags & SOCK_NOSIGPIPE) ? FNOSIGPIPE : 0);
    586 	fp->f_type = DTYPE_SOCKET;
    587 	fp->f_ops = &socketops;
    588 
    589 	type &= ~SOCK_FLAGS_MASK;
    590 	error = socreate(domain, &so, type, proto, l, NULL);
    591 	if (error) {
    592 		fd_abort(curproc, fp, fd);
    593 		return error;
    594 	}
    595 	if (flags & SOCK_NONBLOCK) {
    596 		so->so_state |= SS_NBIO;
    597 	}
    598 	fp->f_socket = so;
    599 	fd_affix(curproc, fp, fd);
    600 
    601 	if (sop != NULL) {
    602 		*sop = so;
    603 	}
    604 	*fdout = fd;
    605 	return error;
    606 }
    607 
    608 int
    609 sofamily(const struct socket *so)
    610 {
    611 	const struct protosw *pr;
    612 	const struct domain *dom;
    613 
    614 	if ((pr = so->so_proto) == NULL)
    615 		return AF_UNSPEC;
    616 	if ((dom = pr->pr_domain) == NULL)
    617 		return AF_UNSPEC;
    618 	return dom->dom_family;
    619 }
    620 
    621 int
    622 sobind(struct socket *so, struct sockaddr *nam, struct lwp *l)
    623 {
    624 	int error;
    625 
    626 	solock(so);
    627 	if (nam->sa_family != so->so_proto->pr_domain->dom_family) {
    628 		sounlock(so);
    629 		return EAFNOSUPPORT;
    630 	}
    631 	error = (*so->so_proto->pr_usrreqs->pr_bind)(so, nam, l);
    632 	sounlock(so);
    633 	return error;
    634 }
    635 
    636 int
    637 solisten(struct socket *so, int backlog, struct lwp *l)
    638 {
    639 	int error;
    640 	short oldopt, oldqlimit;
    641 
    642 	solock(so);
    643 	if ((so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING |
    644 	    SS_ISDISCONNECTING)) != 0) {
    645 		sounlock(so);
    646 		return EINVAL;
    647 	}
    648 	oldopt = so->so_options;
    649 	oldqlimit = so->so_qlimit;
    650 	if (TAILQ_EMPTY(&so->so_q))
    651 		so->so_options |= SO_ACCEPTCONN;
    652 	if (backlog < 0)
    653 		backlog = 0;
    654 	so->so_qlimit = uimin(backlog, somaxconn);
    655 
    656 	error = (*so->so_proto->pr_usrreqs->pr_listen)(so, l);
    657 	if (error != 0) {
    658 		so->so_options = oldopt;
    659 		so->so_qlimit = oldqlimit;
    660 		sounlock(so);
    661 		return error;
    662 	}
    663 	sounlock(so);
    664 	return 0;
    665 }
    666 
    667 void
    668 sofree(struct socket *so)
    669 {
    670 	u_int refs;
    671 
    672 	KASSERT(solocked(so));
    673 
    674 	if (so->so_pcb || (so->so_state & SS_NOFDREF) == 0) {
    675 		sounlock(so);
    676 		return;
    677 	}
    678 	if (so->so_head) {
    679 		/*
    680 		 * We must not decommission a socket that's on the accept(2)
    681 		 * queue.  If we do, then accept(2) may hang after select(2)
    682 		 * indicated that the listening socket was ready.
    683 		 */
    684 		if (!soqremque(so, 0)) {
    685 			sounlock(so);
    686 			return;
    687 		}
    688 	}
    689 	if (so->so_rcv.sb_hiwat)
    690 		(void)chgsbsize(so->so_uidinfo, &so->so_rcv.sb_hiwat, 0,
    691 		    RLIM_INFINITY);
    692 	if (so->so_snd.sb_hiwat)
    693 		(void)chgsbsize(so->so_uidinfo, &so->so_snd.sb_hiwat, 0,
    694 		    RLIM_INFINITY);
    695 	sbrelease(&so->so_snd, so);
    696 	KASSERT(!cv_has_waiters(&so->so_cv));
    697 	KASSERT(!cv_has_waiters(&so->so_rcv.sb_cv));
    698 	KASSERT(!cv_has_waiters(&so->so_snd.sb_cv));
    699 	sorflush(so);
    700 	refs = so->so_aborting;	/* XXX */
    701 	/* Remove acccept filter if one is present. */
    702 	if (so->so_accf != NULL)
    703 		(void)accept_filt_clear(so);
    704 	sounlock(so);
    705 	if (refs == 0)		/* XXX */
    706 		soput(so);
    707 }
    708 
    709 /*
    710  * soclose: close a socket on last file table reference removal.
    711  * Initiate disconnect if connected.  Free socket when disconnect complete.
    712  */
    713 int
    714 soclose(struct socket *so)
    715 {
    716 	struct socket *so2;
    717 	int error = 0;
    718 
    719 	solock(so);
    720 	if (so->so_options & SO_ACCEPTCONN) {
    721 		for (;;) {
    722 			if ((so2 = TAILQ_FIRST(&so->so_q0)) != 0) {
    723 				KASSERT(solocked2(so, so2));
    724 				(void) soqremque(so2, 0);
    725 				/* soabort drops the lock. */
    726 				(void) soabort(so2);
    727 				solock(so);
    728 				continue;
    729 			}
    730 			if ((so2 = TAILQ_FIRST(&so->so_q)) != 0) {
    731 				KASSERT(solocked2(so, so2));
    732 				(void) soqremque(so2, 1);
    733 				/* soabort drops the lock. */
    734 				(void) soabort(so2);
    735 				solock(so);
    736 				continue;
    737 			}
    738 			break;
    739 		}
    740 	}
    741 	if (so->so_pcb == NULL)
    742 		goto discard;
    743 	if (so->so_state & SS_ISCONNECTED) {
    744 		if ((so->so_state & SS_ISDISCONNECTING) == 0) {
    745 			error = sodisconnect(so);
    746 			if (error)
    747 				goto drop;
    748 		}
    749 		if (so->so_options & SO_LINGER) {
    750 			if ((so->so_state & (SS_ISDISCONNECTING|SS_NBIO)) ==
    751 			    (SS_ISDISCONNECTING|SS_NBIO))
    752 				goto drop;
    753 			while (so->so_state & SS_ISCONNECTED) {
    754 				error = sowait(so, true, so->so_linger * hz);
    755 				if (error)
    756 					break;
    757 			}
    758 		}
    759 	}
    760  drop:
    761 	if (so->so_pcb) {
    762 		KASSERT(solocked(so));
    763 		(*so->so_proto->pr_usrreqs->pr_detach)(so);
    764 	}
    765  discard:
    766 	KASSERT((so->so_state & SS_NOFDREF) == 0);
    767 	kauth_cred_free(so->so_cred);
    768 	so->so_cred = NULL;
    769 	so->so_state |= SS_NOFDREF;
    770 	sofree(so);
    771 	return error;
    772 }
    773 
    774 /*
    775  * Must be called with the socket locked..  Will return with it unlocked.
    776  */
    777 int
    778 soabort(struct socket *so)
    779 {
    780 	u_int refs;
    781 	int error;
    782 
    783 	KASSERT(solocked(so));
    784 	KASSERT(so->so_head == NULL);
    785 
    786 	so->so_aborting++;		/* XXX */
    787 	error = (*so->so_proto->pr_usrreqs->pr_abort)(so);
    788 	refs = --so->so_aborting;	/* XXX */
    789 	if (error || (refs == 0)) {
    790 		sofree(so);
    791 	} else {
    792 		sounlock(so);
    793 	}
    794 	return error;
    795 }
    796 
    797 int
    798 soaccept(struct socket *so, struct sockaddr *nam)
    799 {
    800 	int error;
    801 
    802 	KASSERT(solocked(so));
    803 	KASSERT((so->so_state & SS_NOFDREF) != 0);
    804 
    805 	so->so_state &= ~SS_NOFDREF;
    806 	if ((so->so_state & SS_ISDISCONNECTED) == 0 ||
    807 	    (so->so_proto->pr_flags & PR_ABRTACPTDIS) == 0)
    808 		error = (*so->so_proto->pr_usrreqs->pr_accept)(so, nam);
    809 	else
    810 		error = ECONNABORTED;
    811 
    812 	return error;
    813 }
    814 
    815 int
    816 soconnect(struct socket *so, struct sockaddr *nam, struct lwp *l)
    817 {
    818 	int error;
    819 
    820 	KASSERT(solocked(so));
    821 
    822 	if (so->so_options & SO_ACCEPTCONN)
    823 		return EOPNOTSUPP;
    824 	/*
    825 	 * If protocol is connection-based, can only connect once.
    826 	 * Otherwise, if connected, try to disconnect first.
    827 	 * This allows user to disconnect by connecting to, e.g.,
    828 	 * a null address.
    829 	 */
    830 	if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
    831 	    ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
    832 	    (error = sodisconnect(so)))) {
    833 		error = EISCONN;
    834 	} else {
    835 		if (nam->sa_family != so->so_proto->pr_domain->dom_family) {
    836 			return EAFNOSUPPORT;
    837 		}
    838 		error = (*so->so_proto->pr_usrreqs->pr_connect)(so, nam, l);
    839 	}
    840 
    841 	return error;
    842 }
    843 
    844 int
    845 soconnect2(struct socket *so1, struct socket *so2)
    846 {
    847 	KASSERT(solocked2(so1, so2));
    848 
    849 	return (*so1->so_proto->pr_usrreqs->pr_connect2)(so1, so2);
    850 }
    851 
    852 int
    853 sodisconnect(struct socket *so)
    854 {
    855 	int error;
    856 
    857 	KASSERT(solocked(so));
    858 
    859 	if ((so->so_state & SS_ISCONNECTED) == 0) {
    860 		error = ENOTCONN;
    861 	} else if (so->so_state & SS_ISDISCONNECTING) {
    862 		error = EALREADY;
    863 	} else {
    864 		error = (*so->so_proto->pr_usrreqs->pr_disconnect)(so);
    865 	}
    866 	return error;
    867 }
    868 
    869 #define	SBLOCKWAIT(f)	(((f) & MSG_DONTWAIT) ? M_NOWAIT : M_WAITOK)
    870 /*
    871  * Send on a socket.
    872  * If send must go all at once and message is larger than
    873  * send buffering, then hard error.
    874  * Lock against other senders.
    875  * If must go all at once and not enough room now, then
    876  * inform user that this would block and do nothing.
    877  * Otherwise, if nonblocking, send as much as possible.
    878  * The data to be sent is described by "uio" if nonzero,
    879  * otherwise by the mbuf chain "top" (which must be null
    880  * if uio is not).  Data provided in mbuf chain must be small
    881  * enough to send all at once.
    882  *
    883  * Returns nonzero on error, timeout or signal; callers
    884  * must check for short counts if EINTR/ERESTART are returned.
    885  * Data and control buffers are freed on return.
    886  */
    887 int
    888 sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
    889 	struct mbuf *top, struct mbuf *control, int flags, struct lwp *l)
    890 {
    891 	struct mbuf **mp, *m;
    892 	long space, len, resid, clen, mlen;
    893 	int error, s, dontroute, atomic;
    894 	short wakeup_state = 0;
    895 
    896 	clen = 0;
    897 
    898 	/*
    899 	 * solock() provides atomicity of access.  splsoftnet() prevents
    900 	 * protocol processing soft interrupts from interrupting us and
    901 	 * blocking (expensive).
    902 	 */
    903 	s = splsoftnet();
    904 	solock(so);
    905 	atomic = sosendallatonce(so) || top;
    906 	if (uio)
    907 		resid = uio->uio_resid;
    908 	else
    909 		resid = top->m_pkthdr.len;
    910 	/*
    911 	 * In theory resid should be unsigned.
    912 	 * However, space must be signed, as it might be less than 0
    913 	 * if we over-committed, and we must use a signed comparison
    914 	 * of space and resid.  On the other hand, a negative resid
    915 	 * causes us to loop sending 0-length segments to the protocol.
    916 	 */
    917 	if (resid < 0) {
    918 		error = EINVAL;
    919 		goto out;
    920 	}
    921 	dontroute =
    922 	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
    923 	    (so->so_proto->pr_flags & PR_ATOMIC);
    924 	l->l_ru.ru_msgsnd++;
    925 	if (control)
    926 		clen = control->m_len;
    927  restart:
    928 	if ((error = sblock(&so->so_snd, SBLOCKWAIT(flags))) != 0)
    929 		goto out;
    930 	do {
    931 		if (so->so_state & SS_CANTSENDMORE) {
    932 			error = EPIPE;
    933 			goto release;
    934 		}
    935 		if (so->so_error) {
    936 			error = so->so_error;
    937 			if ((flags & MSG_PEEK) == 0)
    938 				so->so_error = 0;
    939 			goto release;
    940 		}
    941 		if ((so->so_state & SS_ISCONNECTED) == 0) {
    942 			if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
    943 				if (resid || clen == 0) {
    944 					error = ENOTCONN;
    945 					goto release;
    946 				}
    947 			} else if (addr == NULL) {
    948 				error = EDESTADDRREQ;
    949 				goto release;
    950 			}
    951 		}
    952 		space = sbspace(&so->so_snd);
    953 		if (flags & MSG_OOB)
    954 			space += 1024;
    955 		if ((atomic && resid > so->so_snd.sb_hiwat) ||
    956 		    clen > so->so_snd.sb_hiwat) {
    957 			error = EMSGSIZE;
    958 			goto release;
    959 		}
    960 		if (space < resid + clen &&
    961 		    (atomic || space < so->so_snd.sb_lowat || space < clen)) {
    962 			if ((so->so_state & SS_NBIO) || (flags & MSG_NBIO)) {
    963 				error = EWOULDBLOCK;
    964 				goto release;
    965 			}
    966 			sbunlock(&so->so_snd);
    967 			if (wakeup_state & SS_RESTARTSYS) {
    968 				error = ERESTART;
    969 				goto out;
    970 			}
    971 			error = sbwait(&so->so_snd);
    972 			if (error)
    973 				goto out;
    974 			wakeup_state = so->so_state;
    975 			goto restart;
    976 		}
    977 		wakeup_state = 0;
    978 		mp = &top;
    979 		space -= clen;
    980 		do {
    981 			if (uio == NULL) {
    982 				/*
    983 				 * Data is prepackaged in "top".
    984 				 */
    985 				resid = 0;
    986 				if (flags & MSG_EOR)
    987 					top->m_flags |= M_EOR;
    988 			} else do {
    989 				sounlock(so);
    990 				splx(s);
    991 				if (top == NULL) {
    992 					m = m_gethdr(M_WAIT, MT_DATA);
    993 					mlen = MHLEN;
    994 					m->m_pkthdr.len = 0;
    995 					m_reset_rcvif(m);
    996 				} else {
    997 					m = m_get(M_WAIT, MT_DATA);
    998 					mlen = MLEN;
    999 				}
   1000 				MCLAIM(m, so->so_snd.sb_mowner);
   1001 				if (sock_loan_thresh >= 0 &&
   1002 				    uio->uio_iov->iov_len >= sock_loan_thresh &&
   1003 				    space >= sock_loan_thresh &&
   1004 				    (len = sosend_loan(so, uio, m,
   1005 						       space)) != 0) {
   1006 					SOSEND_COUNTER_INCR(&sosend_loan_big);
   1007 					space -= len;
   1008 					goto have_data;
   1009 				}
   1010 				if (resid >= MINCLSIZE && space >= MCLBYTES) {
   1011 					SOSEND_COUNTER_INCR(&sosend_copy_big);
   1012 					m_clget(m, M_DONTWAIT);
   1013 					if ((m->m_flags & M_EXT) == 0)
   1014 						goto nopages;
   1015 					mlen = MCLBYTES;
   1016 					if (atomic && top == 0) {
   1017 						len = lmin(MCLBYTES - max_hdr,
   1018 						    resid);
   1019 						m->m_data += max_hdr;
   1020 					} else
   1021 						len = lmin(MCLBYTES, resid);
   1022 					space -= len;
   1023 				} else {
   1024  nopages:
   1025 					SOSEND_COUNTER_INCR(&sosend_copy_small);
   1026 					len = lmin(lmin(mlen, resid), space);
   1027 					space -= len;
   1028 					/*
   1029 					 * For datagram protocols, leave room
   1030 					 * for protocol headers in first mbuf.
   1031 					 */
   1032 					if (atomic && top == 0 && len < mlen)
   1033 						m_align(m, len);
   1034 				}
   1035 				error = uiomove(mtod(m, void *), (int)len, uio);
   1036  have_data:
   1037 				resid = uio->uio_resid;
   1038 				m->m_len = len;
   1039 				*mp = m;
   1040 				top->m_pkthdr.len += len;
   1041 				s = splsoftnet();
   1042 				solock(so);
   1043 				if (error != 0)
   1044 					goto release;
   1045 				mp = &m->m_next;
   1046 				if (resid <= 0) {
   1047 					if (flags & MSG_EOR)
   1048 						top->m_flags |= M_EOR;
   1049 					break;
   1050 				}
   1051 			} while (space > 0 && atomic);
   1052 
   1053 			if (so->so_state & SS_CANTSENDMORE) {
   1054 				error = EPIPE;
   1055 				goto release;
   1056 			}
   1057 			if (dontroute)
   1058 				so->so_options |= SO_DONTROUTE;
   1059 			if (resid > 0)
   1060 				so->so_state |= SS_MORETOCOME;
   1061 			if (flags & MSG_OOB) {
   1062 				error = (*so->so_proto->pr_usrreqs->pr_sendoob)(
   1063 				    so, top, control);
   1064 			} else {
   1065 				error = (*so->so_proto->pr_usrreqs->pr_send)(so,
   1066 				    top, addr, control, l);
   1067 			}
   1068 			if (dontroute)
   1069 				so->so_options &= ~SO_DONTROUTE;
   1070 			if (resid > 0)
   1071 				so->so_state &= ~SS_MORETOCOME;
   1072 			clen = 0;
   1073 			control = NULL;
   1074 			top = NULL;
   1075 			mp = &top;
   1076 			if (error != 0)
   1077 				goto release;
   1078 		} while (resid && space > 0);
   1079 	} while (resid);
   1080 
   1081  release:
   1082 	sbunlock(&so->so_snd);
   1083  out:
   1084 	sounlock(so);
   1085 	splx(s);
   1086 	if (top)
   1087 		m_freem(top);
   1088 	if (control)
   1089 		m_freem(control);
   1090 	return error;
   1091 }
   1092 
   1093 /*
   1094  * Following replacement or removal of the first mbuf on the first
   1095  * mbuf chain of a socket buffer, push necessary state changes back
   1096  * into the socket buffer so that other consumers see the values
   1097  * consistently.  'nextrecord' is the caller's locally stored value of
   1098  * the original value of sb->sb_mb->m_nextpkt which must be restored
   1099  * when the lead mbuf changes.  NOTE: 'nextrecord' may be NULL.
   1100  */
   1101 static void
   1102 sbsync(struct sockbuf *sb, struct mbuf *nextrecord)
   1103 {
   1104 
   1105 	KASSERT(solocked(sb->sb_so));
   1106 
   1107 	/*
   1108 	 * First, update for the new value of nextrecord.  If necessary,
   1109 	 * make it the first record.
   1110 	 */
   1111 	if (sb->sb_mb != NULL)
   1112 		sb->sb_mb->m_nextpkt = nextrecord;
   1113 	else
   1114 		sb->sb_mb = nextrecord;
   1115 
   1116         /*
   1117          * Now update any dependent socket buffer fields to reflect
   1118          * the new state.  This is an inline of SB_EMPTY_FIXUP, with
   1119          * the addition of a second clause that takes care of the
   1120          * case where sb_mb has been updated, but remains the last
   1121          * record.
   1122          */
   1123         if (sb->sb_mb == NULL) {
   1124                 sb->sb_mbtail = NULL;
   1125                 sb->sb_lastrecord = NULL;
   1126         } else if (sb->sb_mb->m_nextpkt == NULL)
   1127                 sb->sb_lastrecord = sb->sb_mb;
   1128 }
   1129 
   1130 /*
   1131  * Implement receive operations on a socket.
   1132  *
   1133  * We depend on the way that records are added to the sockbuf by sbappend*. In
   1134  * particular, each record (mbufs linked through m_next) must begin with an
   1135  * address if the protocol so specifies, followed by an optional mbuf or mbufs
   1136  * containing ancillary data, and then zero or more mbufs of data.
   1137  *
   1138  * In order to avoid blocking network interrupts for the entire time here, we
   1139  * splx() while doing the actual copy to user space. Although the sockbuf is
   1140  * locked, new data may still be appended, and thus we must maintain
   1141  * consistency of the sockbuf during that time.
   1142  *
   1143  * The caller may receive the data as a single mbuf chain by supplying an mbuf
   1144  * **mp0 for use in returning the chain. The uio is then used only for the
   1145  * count in uio_resid.
   1146  */
   1147 int
   1148 soreceive(struct socket *so, struct mbuf **paddr, struct uio *uio,
   1149     struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
   1150 {
   1151 	struct lwp *l = curlwp;
   1152 	struct mbuf *m, **mp, *mt;
   1153 	size_t len, offset, moff, orig_resid;
   1154 	int atomic, flags, error, s, type;
   1155 	const struct protosw *pr;
   1156 	struct mbuf *nextrecord;
   1157 	int mbuf_removed = 0;
   1158 	const struct domain *dom;
   1159 	short wakeup_state = 0;
   1160 
   1161 	pr = so->so_proto;
   1162 	atomic = pr->pr_flags & PR_ATOMIC;
   1163 	dom = pr->pr_domain;
   1164 	mp = mp0;
   1165 	type = 0;
   1166 	orig_resid = uio->uio_resid;
   1167 
   1168 	if (paddr != NULL)
   1169 		*paddr = NULL;
   1170 	if (controlp != NULL)
   1171 		*controlp = NULL;
   1172 	if (flagsp != NULL)
   1173 		flags = *flagsp &~ MSG_EOR;
   1174 	else
   1175 		flags = 0;
   1176 
   1177 	if (flags & MSG_OOB) {
   1178 		m = m_get(M_WAIT, MT_DATA);
   1179 		solock(so);
   1180 		error = (*pr->pr_usrreqs->pr_recvoob)(so, m, flags & MSG_PEEK);
   1181 		sounlock(so);
   1182 		if (error)
   1183 			goto bad;
   1184 		do {
   1185 			error = uiomove(mtod(m, void *),
   1186 			    MIN(uio->uio_resid, m->m_len), uio);
   1187 			m = m_free(m);
   1188 		} while (uio->uio_resid > 0 && error == 0 && m);
   1189 bad:
   1190 		if (m != NULL)
   1191 			m_freem(m);
   1192 		return error;
   1193 	}
   1194 	if (mp != NULL)
   1195 		*mp = NULL;
   1196 
   1197 	/*
   1198 	 * solock() provides atomicity of access.  splsoftnet() prevents
   1199 	 * protocol processing soft interrupts from interrupting us and
   1200 	 * blocking (expensive).
   1201 	 */
   1202 	s = splsoftnet();
   1203 	solock(so);
   1204 restart:
   1205 	if ((error = sblock(&so->so_rcv, SBLOCKWAIT(flags))) != 0) {
   1206 		sounlock(so);
   1207 		splx(s);
   1208 		return error;
   1209 	}
   1210 	m = so->so_rcv.sb_mb;
   1211 
   1212 	/*
   1213 	 * If we have less data than requested, block awaiting more
   1214 	 * (subject to any timeout) if:
   1215 	 *   1. the current count is less than the low water mark,
   1216 	 *   2. MSG_WAITALL is set, and it is possible to do the entire
   1217 	 *	receive operation at once if we block (resid <= hiwat), or
   1218 	 *   3. MSG_DONTWAIT is not set.
   1219 	 * If MSG_WAITALL is set but resid is larger than the receive buffer,
   1220 	 * we have to do the receive in sections, and thus risk returning
   1221 	 * a short count if a timeout or signal occurs after we start.
   1222 	 */
   1223 	if (m == NULL ||
   1224 	    ((flags & MSG_DONTWAIT) == 0 &&
   1225 	     so->so_rcv.sb_cc < uio->uio_resid &&
   1226 	     (so->so_rcv.sb_cc < so->so_rcv.sb_lowat ||
   1227 	      ((flags & MSG_WAITALL) &&
   1228 	       uio->uio_resid <= so->so_rcv.sb_hiwat)) &&
   1229 	     m->m_nextpkt == NULL && !atomic)) {
   1230 #ifdef DIAGNOSTIC
   1231 		if (m == NULL && so->so_rcv.sb_cc)
   1232 			panic("receive 1");
   1233 #endif
   1234 		if (so->so_error || so->so_rerror) {
   1235 			u_short *e;
   1236 			if (m != NULL)
   1237 				goto dontblock;
   1238 			e = so->so_error ? &so->so_error : &so->so_rerror;
   1239 			error = *e;
   1240 			if ((flags & MSG_PEEK) == 0)
   1241 				*e = 0;
   1242 			goto release;
   1243 		}
   1244 		if (so->so_state & SS_CANTRCVMORE) {
   1245 			if (m != NULL)
   1246 				goto dontblock;
   1247 			else
   1248 				goto release;
   1249 		}
   1250 		for (; m != NULL; m = m->m_next)
   1251 			if (m->m_type == MT_OOBDATA  || (m->m_flags & M_EOR)) {
   1252 				m = so->so_rcv.sb_mb;
   1253 				goto dontblock;
   1254 			}
   1255 		if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
   1256 		    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
   1257 			error = ENOTCONN;
   1258 			goto release;
   1259 		}
   1260 		if (uio->uio_resid == 0)
   1261 			goto release;
   1262 		if ((so->so_state & SS_NBIO) ||
   1263 		    (flags & (MSG_DONTWAIT|MSG_NBIO))) {
   1264 			error = EWOULDBLOCK;
   1265 			goto release;
   1266 		}
   1267 		SBLASTRECORDCHK(&so->so_rcv, "soreceive sbwait 1");
   1268 		SBLASTMBUFCHK(&so->so_rcv, "soreceive sbwait 1");
   1269 		sbunlock(&so->so_rcv);
   1270 		if (wakeup_state & SS_RESTARTSYS)
   1271 			error = ERESTART;
   1272 		else
   1273 			error = sbwait(&so->so_rcv);
   1274 		if (error != 0) {
   1275 			sounlock(so);
   1276 			splx(s);
   1277 			return error;
   1278 		}
   1279 		wakeup_state = so->so_state;
   1280 		goto restart;
   1281 	}
   1282 
   1283 dontblock:
   1284 	/*
   1285 	 * On entry here, m points to the first record of the socket buffer.
   1286 	 * From this point onward, we maintain 'nextrecord' as a cache of the
   1287 	 * pointer to the next record in the socket buffer.  We must keep the
   1288 	 * various socket buffer pointers and local stack versions of the
   1289 	 * pointers in sync, pushing out modifications before dropping the
   1290 	 * socket lock, and re-reading them when picking it up.
   1291 	 *
   1292 	 * Otherwise, we will race with the network stack appending new data
   1293 	 * or records onto the socket buffer by using inconsistent/stale
   1294 	 * versions of the field, possibly resulting in socket buffer
   1295 	 * corruption.
   1296 	 *
   1297 	 * By holding the high-level sblock(), we prevent simultaneous
   1298 	 * readers from pulling off the front of the socket buffer.
   1299 	 */
   1300 	if (l != NULL)
   1301 		l->l_ru.ru_msgrcv++;
   1302 	KASSERT(m == so->so_rcv.sb_mb);
   1303 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 1");
   1304 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 1");
   1305 	nextrecord = m->m_nextpkt;
   1306 
   1307 	if (pr->pr_flags & PR_ADDR) {
   1308 		KASSERT(m->m_type == MT_SONAME);
   1309 		orig_resid = 0;
   1310 		if (flags & MSG_PEEK) {
   1311 			if (paddr)
   1312 				*paddr = m_copym(m, 0, m->m_len, M_DONTWAIT);
   1313 			m = m->m_next;
   1314 		} else {
   1315 			sbfree(&so->so_rcv, m);
   1316 			mbuf_removed = 1;
   1317 			if (paddr != NULL) {
   1318 				*paddr = m;
   1319 				so->so_rcv.sb_mb = m->m_next;
   1320 				m->m_next = NULL;
   1321 				m = so->so_rcv.sb_mb;
   1322 			} else {
   1323 				m = so->so_rcv.sb_mb = m_free(m);
   1324 			}
   1325 			sbsync(&so->so_rcv, nextrecord);
   1326 		}
   1327 	}
   1328 
   1329 	if (pr->pr_flags & PR_ADDR_OPT) {
   1330 		/*
   1331 		 * For SCTP we may be getting a whole message OR a partial
   1332 		 * delivery.
   1333 		 */
   1334 		if (m->m_type == MT_SONAME) {
   1335 			orig_resid = 0;
   1336 			if (flags & MSG_PEEK) {
   1337 				if (paddr)
   1338 					*paddr = m_copym(m, 0, m->m_len, M_DONTWAIT);
   1339 				m = m->m_next;
   1340 			} else {
   1341 				sbfree(&so->so_rcv, m);
   1342 				mbuf_removed = 1;
   1343 				if (paddr) {
   1344 					*paddr = m;
   1345 					so->so_rcv.sb_mb = m->m_next;
   1346 					m->m_next = 0;
   1347 					m = so->so_rcv.sb_mb;
   1348 				} else {
   1349 					m = so->so_rcv.sb_mb = m_free(m);
   1350 				}
   1351 				sbsync(&so->so_rcv, nextrecord);
   1352 			}
   1353 		}
   1354 	}
   1355 
   1356 	/*
   1357 	 * Process one or more MT_CONTROL mbufs present before any data mbufs
   1358 	 * in the first mbuf chain on the socket buffer.  If MSG_PEEK, we
   1359 	 * just copy the data; if !MSG_PEEK, we call into the protocol to
   1360 	 * perform externalization (or freeing if controlp == NULL).
   1361 	 */
   1362 	if (__predict_false(m != NULL && m->m_type == MT_CONTROL)) {
   1363 		struct mbuf *cm = NULL, *cmn;
   1364 		struct mbuf **cme = &cm;
   1365 
   1366 		do {
   1367 			if (flags & MSG_PEEK) {
   1368 				if (controlp != NULL) {
   1369 					*controlp = m_copym(m, 0, m->m_len, M_DONTWAIT);
   1370 					controlp = &(*controlp)->m_next;
   1371 				}
   1372 				m = m->m_next;
   1373 			} else {
   1374 				sbfree(&so->so_rcv, m);
   1375 				so->so_rcv.sb_mb = m->m_next;
   1376 				m->m_next = NULL;
   1377 				*cme = m;
   1378 				cme = &(*cme)->m_next;
   1379 				m = so->so_rcv.sb_mb;
   1380 			}
   1381 		} while (m != NULL && m->m_type == MT_CONTROL);
   1382 		if ((flags & MSG_PEEK) == 0)
   1383 			sbsync(&so->so_rcv, nextrecord);
   1384 
   1385 		for (; cm != NULL; cm = cmn) {
   1386 			cmn = cm->m_next;
   1387 			cm->m_next = NULL;
   1388 			type = mtod(cm, struct cmsghdr *)->cmsg_type;
   1389 			if (controlp != NULL) {
   1390 				if (dom->dom_externalize != NULL &&
   1391 				    type == SCM_RIGHTS) {
   1392 					sounlock(so);
   1393 					splx(s);
   1394 					error = (*dom->dom_externalize)(cm, l,
   1395 					    (flags & MSG_CMSG_CLOEXEC) ?
   1396 					    O_CLOEXEC : 0);
   1397 					s = splsoftnet();
   1398 					solock(so);
   1399 				}
   1400 				*controlp = cm;
   1401 				while (*controlp != NULL)
   1402 					controlp = &(*controlp)->m_next;
   1403 			} else {
   1404 				/*
   1405 				 * Dispose of any SCM_RIGHTS message that went
   1406 				 * through the read path rather than recv.
   1407 				 */
   1408 				if (dom->dom_dispose != NULL &&
   1409 				    type == SCM_RIGHTS) {
   1410 					sounlock(so);
   1411 					(*dom->dom_dispose)(cm);
   1412 					solock(so);
   1413 				}
   1414 				m_freem(cm);
   1415 			}
   1416 		}
   1417 		if (m != NULL)
   1418 			nextrecord = so->so_rcv.sb_mb->m_nextpkt;
   1419 		else
   1420 			nextrecord = so->so_rcv.sb_mb;
   1421 		orig_resid = 0;
   1422 	}
   1423 
   1424 	/* If m is non-NULL, we have some data to read. */
   1425 	if (__predict_true(m != NULL)) {
   1426 		type = m->m_type;
   1427 		if (type == MT_OOBDATA)
   1428 			flags |= MSG_OOB;
   1429 	}
   1430 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 2");
   1431 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 2");
   1432 
   1433 	moff = 0;
   1434 	offset = 0;
   1435 	while (m != NULL && uio->uio_resid > 0 && error == 0) {
   1436 		/*
   1437 		 * If the type of mbuf has changed, end the receive
   1438 		 * operation and do a short read.
   1439 		 */
   1440 		if (m->m_type == MT_OOBDATA) {
   1441 			if (type != MT_OOBDATA)
   1442 				break;
   1443 		} else if (type == MT_OOBDATA) {
   1444 			break;
   1445 		} else if (m->m_type == MT_CONTROL) {
   1446 			break;
   1447 		}
   1448 #ifdef DIAGNOSTIC
   1449 		else if (m->m_type != MT_DATA && m->m_type != MT_HEADER) {
   1450 			panic("%s: m_type=%d", __func__, m->m_type);
   1451 		}
   1452 #endif
   1453 
   1454 		so->so_state &= ~SS_RCVATMARK;
   1455 		wakeup_state = 0;
   1456 		len = uio->uio_resid;
   1457 		if (so->so_oobmark && len > so->so_oobmark - offset)
   1458 			len = so->so_oobmark - offset;
   1459 		if (len > m->m_len - moff)
   1460 			len = m->m_len - moff;
   1461 
   1462 		/*
   1463 		 * If mp is set, just pass back the mbufs.
   1464 		 * Otherwise copy them out via the uio, then free.
   1465 		 * Sockbuf must be consistent here (points to current mbuf,
   1466 		 * it points to next record) when we drop priority;
   1467 		 * we must note any additions to the sockbuf when we
   1468 		 * block interrupts again.
   1469 		 */
   1470 		if (mp == NULL) {
   1471 			SBLASTRECORDCHK(&so->so_rcv, "soreceive uiomove");
   1472 			SBLASTMBUFCHK(&so->so_rcv, "soreceive uiomove");
   1473 			sounlock(so);
   1474 			splx(s);
   1475 			error = uiomove(mtod(m, char *) + moff, len, uio);
   1476 			s = splsoftnet();
   1477 			solock(so);
   1478 			if (error != 0) {
   1479 				/*
   1480 				 * If any part of the record has been removed
   1481 				 * (such as the MT_SONAME mbuf, which will
   1482 				 * happen when PR_ADDR, and thus also
   1483 				 * PR_ATOMIC, is set), then drop the entire
   1484 				 * record to maintain the atomicity of the
   1485 				 * receive operation.
   1486 				 *
   1487 				 * This avoids a later panic("receive 1a")
   1488 				 * when compiled with DIAGNOSTIC.
   1489 				 */
   1490 				if (m && mbuf_removed && atomic)
   1491 					(void) sbdroprecord(&so->so_rcv);
   1492 
   1493 				goto release;
   1494 			}
   1495 		} else {
   1496 			uio->uio_resid -= len;
   1497 		}
   1498 
   1499 		if (len == m->m_len - moff) {
   1500 			if (m->m_flags & M_EOR)
   1501 				flags |= MSG_EOR;
   1502 #ifdef SCTP
   1503 			if (m->m_flags & M_NOTIFICATION)
   1504 				flags |= MSG_NOTIFICATION;
   1505 #endif
   1506 			if (flags & MSG_PEEK) {
   1507 				m = m->m_next;
   1508 				moff = 0;
   1509 			} else {
   1510 				nextrecord = m->m_nextpkt;
   1511 				sbfree(&so->so_rcv, m);
   1512 				if (mp) {
   1513 					*mp = m;
   1514 					mp = &m->m_next;
   1515 					so->so_rcv.sb_mb = m = m->m_next;
   1516 					*mp = NULL;
   1517 				} else {
   1518 					m = so->so_rcv.sb_mb = m_free(m);
   1519 				}
   1520 				/*
   1521 				 * If m != NULL, we also know that
   1522 				 * so->so_rcv.sb_mb != NULL.
   1523 				 */
   1524 				KASSERT(so->so_rcv.sb_mb == m);
   1525 				if (m) {
   1526 					m->m_nextpkt = nextrecord;
   1527 					if (nextrecord == NULL)
   1528 						so->so_rcv.sb_lastrecord = m;
   1529 				} else {
   1530 					so->so_rcv.sb_mb = nextrecord;
   1531 					SB_EMPTY_FIXUP(&so->so_rcv);
   1532 				}
   1533 				SBLASTRECORDCHK(&so->so_rcv, "soreceive 3");
   1534 				SBLASTMBUFCHK(&so->so_rcv, "soreceive 3");
   1535 			}
   1536 		} else if (flags & MSG_PEEK) {
   1537 			moff += len;
   1538 		} else {
   1539 			if (mp != NULL) {
   1540 				mt = m_copym(m, 0, len, M_NOWAIT);
   1541 				if (__predict_false(mt == NULL)) {
   1542 					sounlock(so);
   1543 					mt = m_copym(m, 0, len, M_WAIT);
   1544 					solock(so);
   1545 				}
   1546 				*mp = mt;
   1547 			}
   1548 			m->m_data += len;
   1549 			m->m_len -= len;
   1550 			so->so_rcv.sb_cc -= len;
   1551 		}
   1552 
   1553 		if (so->so_oobmark) {
   1554 			if ((flags & MSG_PEEK) == 0) {
   1555 				so->so_oobmark -= len;
   1556 				if (so->so_oobmark == 0) {
   1557 					so->so_state |= SS_RCVATMARK;
   1558 					break;
   1559 				}
   1560 			} else {
   1561 				offset += len;
   1562 				if (offset == so->so_oobmark)
   1563 					break;
   1564 			}
   1565 		} else {
   1566 			so->so_state &= ~SS_POLLRDBAND;
   1567 		}
   1568 		if (flags & MSG_EOR)
   1569 			break;
   1570 
   1571 		/*
   1572 		 * If the MSG_WAITALL flag is set (for non-atomic socket),
   1573 		 * we must not quit until "uio->uio_resid == 0" or an error
   1574 		 * termination.  If a signal/timeout occurs, return
   1575 		 * with a short count but without error.
   1576 		 * Keep sockbuf locked against other readers.
   1577 		 */
   1578 		while (flags & MSG_WAITALL && m == NULL && uio->uio_resid > 0 &&
   1579 		    !sosendallatonce(so) && !nextrecord) {
   1580 			if (so->so_error || so->so_rerror ||
   1581 			    so->so_state & SS_CANTRCVMORE)
   1582 				break;
   1583 			/*
   1584 			 * If we are peeking and the socket receive buffer is
   1585 			 * full, stop since we can't get more data to peek at.
   1586 			 */
   1587 			if ((flags & MSG_PEEK) && sbspace(&so->so_rcv) <= 0)
   1588 				break;
   1589 			/*
   1590 			 * If we've drained the socket buffer, tell the
   1591 			 * protocol in case it needs to do something to
   1592 			 * get it filled again.
   1593 			 */
   1594 			if ((pr->pr_flags & PR_WANTRCVD) && so->so_pcb)
   1595 				(*pr->pr_usrreqs->pr_rcvd)(so, flags, l);
   1596 			SBLASTRECORDCHK(&so->so_rcv, "soreceive sbwait 2");
   1597 			SBLASTMBUFCHK(&so->so_rcv, "soreceive sbwait 2");
   1598 			if (wakeup_state & SS_RESTARTSYS)
   1599 				error = ERESTART;
   1600 			else
   1601 				error = sbwait(&so->so_rcv);
   1602 			if (error != 0) {
   1603 				sbunlock(&so->so_rcv);
   1604 				sounlock(so);
   1605 				splx(s);
   1606 				return 0;
   1607 			}
   1608 			if ((m = so->so_rcv.sb_mb) != NULL)
   1609 				nextrecord = m->m_nextpkt;
   1610 			wakeup_state = so->so_state;
   1611 		}
   1612 	}
   1613 
   1614 	if (m && atomic) {
   1615 		flags |= MSG_TRUNC;
   1616 		if ((flags & MSG_PEEK) == 0)
   1617 			(void) sbdroprecord(&so->so_rcv);
   1618 	}
   1619 	if ((flags & MSG_PEEK) == 0) {
   1620 		if (m == NULL) {
   1621 			/*
   1622 			 * First part is an inline SB_EMPTY_FIXUP().  Second
   1623 			 * part makes sure sb_lastrecord is up-to-date if
   1624 			 * there is still data in the socket buffer.
   1625 			 */
   1626 			so->so_rcv.sb_mb = nextrecord;
   1627 			if (so->so_rcv.sb_mb == NULL) {
   1628 				so->so_rcv.sb_mbtail = NULL;
   1629 				so->so_rcv.sb_lastrecord = NULL;
   1630 			} else if (nextrecord->m_nextpkt == NULL)
   1631 				so->so_rcv.sb_lastrecord = nextrecord;
   1632 		}
   1633 		SBLASTRECORDCHK(&so->so_rcv, "soreceive 4");
   1634 		SBLASTMBUFCHK(&so->so_rcv, "soreceive 4");
   1635 		if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
   1636 			(*pr->pr_usrreqs->pr_rcvd)(so, flags, l);
   1637 	}
   1638 	if (orig_resid == uio->uio_resid && orig_resid &&
   1639 	    (flags & MSG_EOR) == 0 && (so->so_state & SS_CANTRCVMORE) == 0) {
   1640 		sbunlock(&so->so_rcv);
   1641 		goto restart;
   1642 	}
   1643 
   1644 	if (flagsp != NULL)
   1645 		*flagsp |= flags;
   1646 release:
   1647 	sbunlock(&so->so_rcv);
   1648 	sounlock(so);
   1649 	splx(s);
   1650 	return error;
   1651 }
   1652 
   1653 int
   1654 soshutdown(struct socket *so, int how)
   1655 {
   1656 	const struct protosw *pr;
   1657 	int error;
   1658 
   1659 	KASSERT(solocked(so));
   1660 
   1661 	pr = so->so_proto;
   1662 	if (!(how == SHUT_RD || how == SHUT_WR || how == SHUT_RDWR))
   1663 		return EINVAL;
   1664 
   1665 	if (how == SHUT_RD || how == SHUT_RDWR) {
   1666 		sorflush(so);
   1667 		error = 0;
   1668 	}
   1669 	if (how == SHUT_WR || how == SHUT_RDWR)
   1670 		error = (*pr->pr_usrreqs->pr_shutdown)(so);
   1671 
   1672 	return error;
   1673 }
   1674 
   1675 void
   1676 sorestart(struct socket *so)
   1677 {
   1678 	/*
   1679 	 * An application has called close() on an fd on which another
   1680 	 * of its threads has called a socket system call.
   1681 	 * Mark this and wake everyone up, and code that would block again
   1682 	 * instead returns ERESTART.
   1683 	 * On system call re-entry the fd is validated and EBADF returned.
   1684 	 * Any other fd will block again on the 2nd syscall.
   1685 	 */
   1686 	solock(so);
   1687 	so->so_state |= SS_RESTARTSYS;
   1688 	cv_broadcast(&so->so_cv);
   1689 	cv_broadcast(&so->so_snd.sb_cv);
   1690 	cv_broadcast(&so->so_rcv.sb_cv);
   1691 	sounlock(so);
   1692 }
   1693 
   1694 void
   1695 sorflush(struct socket *so)
   1696 {
   1697 	struct sockbuf *sb, asb;
   1698 	const struct protosw *pr;
   1699 
   1700 	KASSERT(solocked(so));
   1701 
   1702 	sb = &so->so_rcv;
   1703 	pr = so->so_proto;
   1704 	socantrcvmore(so);
   1705 	sb->sb_flags |= SB_NOINTR;
   1706 	(void )sblock(sb, M_WAITOK);
   1707 	sbunlock(sb);
   1708 	asb = *sb;
   1709 	/*
   1710 	 * Clear most of the sockbuf structure, but leave some of the
   1711 	 * fields valid.
   1712 	 */
   1713 	memset(&sb->sb_startzero, 0,
   1714 	    sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
   1715 	if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose) {
   1716 		sounlock(so);
   1717 		(*pr->pr_domain->dom_dispose)(asb.sb_mb);
   1718 		solock(so);
   1719 	}
   1720 	sbrelease(&asb, so);
   1721 }
   1722 
   1723 /*
   1724  * internal set SOL_SOCKET options
   1725  */
   1726 static int
   1727 sosetopt1(struct socket *so, const struct sockopt *sopt)
   1728 {
   1729 	int error, opt;
   1730 	int optval = 0; /* XXX: gcc */
   1731 	struct linger l;
   1732 	struct timeval tv;
   1733 
   1734 	opt = sopt->sopt_name;
   1735 
   1736 	switch (opt) {
   1737 
   1738 	case SO_ACCEPTFILTER:
   1739 		error = accept_filt_setopt(so, sopt);
   1740 		KASSERT(solocked(so));
   1741 		break;
   1742 
   1743 	case SO_LINGER:
   1744 		error = sockopt_get(sopt, &l, sizeof(l));
   1745 		solock(so);
   1746 		if (error)
   1747 			break;
   1748 		if (l.l_linger < 0 || l.l_linger > USHRT_MAX ||
   1749 		    l.l_linger > (INT_MAX / hz)) {
   1750 			error = EDOM;
   1751 			break;
   1752 		}
   1753 		so->so_linger = l.l_linger;
   1754 		if (l.l_onoff)
   1755 			so->so_options |= SO_LINGER;
   1756 		else
   1757 			so->so_options &= ~SO_LINGER;
   1758 		break;
   1759 
   1760 	case SO_DEBUG:
   1761 	case SO_KEEPALIVE:
   1762 	case SO_DONTROUTE:
   1763 	case SO_USELOOPBACK:
   1764 	case SO_BROADCAST:
   1765 	case SO_REUSEADDR:
   1766 	case SO_REUSEPORT:
   1767 	case SO_OOBINLINE:
   1768 	case SO_TIMESTAMP:
   1769 	case SO_NOSIGPIPE:
   1770 	case SO_RERROR:
   1771 		error = sockopt_getint(sopt, &optval);
   1772 		solock(so);
   1773 		if (error)
   1774 			break;
   1775 		if (optval)
   1776 			so->so_options |= opt;
   1777 		else
   1778 			so->so_options &= ~opt;
   1779 		break;
   1780 
   1781 	case SO_SNDBUF:
   1782 	case SO_RCVBUF:
   1783 	case SO_SNDLOWAT:
   1784 	case SO_RCVLOWAT:
   1785 		error = sockopt_getint(sopt, &optval);
   1786 		solock(so);
   1787 		if (error)
   1788 			break;
   1789 
   1790 		/*
   1791 		 * Values < 1 make no sense for any of these
   1792 		 * options, so disallow them.
   1793 		 */
   1794 		if (optval < 1) {
   1795 			error = EINVAL;
   1796 			break;
   1797 		}
   1798 
   1799 		switch (opt) {
   1800 		case SO_SNDBUF:
   1801 			if (sbreserve(&so->so_snd, (u_long)optval, so) == 0) {
   1802 				error = ENOBUFS;
   1803 				break;
   1804 			}
   1805 			if (sofixedbuf)
   1806 				so->so_snd.sb_flags &= ~SB_AUTOSIZE;
   1807 			break;
   1808 
   1809 		case SO_RCVBUF:
   1810 			if (sbreserve(&so->so_rcv, (u_long)optval, so) == 0) {
   1811 				error = ENOBUFS;
   1812 				break;
   1813 			}
   1814 			if (sofixedbuf)
   1815 				so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
   1816 			break;
   1817 
   1818 		/*
   1819 		 * Make sure the low-water is never greater than
   1820 		 * the high-water.
   1821 		 */
   1822 		case SO_SNDLOWAT:
   1823 			if (optval > so->so_snd.sb_hiwat)
   1824 				optval = so->so_snd.sb_hiwat;
   1825 
   1826 			so->so_snd.sb_lowat = optval;
   1827 			break;
   1828 
   1829 		case SO_RCVLOWAT:
   1830 			if (optval > so->so_rcv.sb_hiwat)
   1831 				optval = so->so_rcv.sb_hiwat;
   1832 
   1833 			so->so_rcv.sb_lowat = optval;
   1834 			break;
   1835 		}
   1836 		break;
   1837 
   1838 	case SO_SNDTIMEO:
   1839 	case SO_RCVTIMEO:
   1840 		solock(so);
   1841 		error = sockopt_get(sopt, &tv, sizeof(tv));
   1842 		if (error)
   1843 			break;
   1844 
   1845 		if (tv.tv_sec < 0 || tv.tv_usec < 0 || tv.tv_usec >= 1000000) {
   1846 			error = EDOM;
   1847 			break;
   1848 		}
   1849 		if (tv.tv_sec > (INT_MAX - tv.tv_usec / tick) / hz) {
   1850 			error = EDOM;
   1851 			break;
   1852 		}
   1853 
   1854 		optval = tv.tv_sec * hz + tv.tv_usec / tick;
   1855 		if (optval == 0 && tv.tv_usec != 0)
   1856 			optval = 1;
   1857 
   1858 		switch (opt) {
   1859 		case SO_SNDTIMEO:
   1860 			so->so_snd.sb_timeo = optval;
   1861 			break;
   1862 		case SO_RCVTIMEO:
   1863 			so->so_rcv.sb_timeo = optval;
   1864 			break;
   1865 		}
   1866 		break;
   1867 
   1868 	default:
   1869 		MODULE_HOOK_CALL(uipc_socket_50_setopt1_hook,
   1870 		    (opt, so, sopt), enosys(), error);
   1871 		if (error == ENOSYS || error == EPASSTHROUGH) {
   1872 			solock(so);
   1873 			error = ENOPROTOOPT;
   1874 		}
   1875 		break;
   1876 	}
   1877 	KASSERT(solocked(so));
   1878 	return error;
   1879 }
   1880 
   1881 int
   1882 sosetopt(struct socket *so, struct sockopt *sopt)
   1883 {
   1884 	int error, prerr;
   1885 
   1886 	if (sopt->sopt_level == SOL_SOCKET) {
   1887 		error = sosetopt1(so, sopt);
   1888 		KASSERT(solocked(so));
   1889 	} else {
   1890 		error = ENOPROTOOPT;
   1891 		solock(so);
   1892 	}
   1893 
   1894 	if ((error == 0 || error == ENOPROTOOPT) &&
   1895 	    so->so_proto != NULL && so->so_proto->pr_ctloutput != NULL) {
   1896 		/* give the protocol stack a shot */
   1897 		prerr = (*so->so_proto->pr_ctloutput)(PRCO_SETOPT, so, sopt);
   1898 		if (prerr == 0)
   1899 			error = 0;
   1900 		else if (prerr != ENOPROTOOPT)
   1901 			error = prerr;
   1902 	}
   1903 	sounlock(so);
   1904 	return error;
   1905 }
   1906 
   1907 /*
   1908  * so_setsockopt() is a wrapper providing a sockopt structure for sosetopt()
   1909  */
   1910 int
   1911 so_setsockopt(struct lwp *l, struct socket *so, int level, int name,
   1912     const void *val, size_t valsize)
   1913 {
   1914 	struct sockopt sopt;
   1915 	int error;
   1916 
   1917 	KASSERT(valsize == 0 || val != NULL);
   1918 
   1919 	sockopt_init(&sopt, level, name, valsize);
   1920 	sockopt_set(&sopt, val, valsize);
   1921 
   1922 	error = sosetopt(so, &sopt);
   1923 
   1924 	sockopt_destroy(&sopt);
   1925 
   1926 	return error;
   1927 }
   1928 
   1929 /*
   1930  * internal get SOL_SOCKET options
   1931  */
   1932 static int
   1933 sogetopt1(struct socket *so, struct sockopt *sopt)
   1934 {
   1935 	int error, optval, opt;
   1936 	struct linger l;
   1937 	struct timeval tv;
   1938 
   1939 	switch ((opt = sopt->sopt_name)) {
   1940 
   1941 	case SO_ACCEPTFILTER:
   1942 		error = accept_filt_getopt(so, sopt);
   1943 		break;
   1944 
   1945 	case SO_LINGER:
   1946 		l.l_onoff = (so->so_options & SO_LINGER) ? 1 : 0;
   1947 		l.l_linger = so->so_linger;
   1948 
   1949 		error = sockopt_set(sopt, &l, sizeof(l));
   1950 		break;
   1951 
   1952 	case SO_USELOOPBACK:
   1953 	case SO_DONTROUTE:
   1954 	case SO_DEBUG:
   1955 	case SO_KEEPALIVE:
   1956 	case SO_REUSEADDR:
   1957 	case SO_REUSEPORT:
   1958 	case SO_BROADCAST:
   1959 	case SO_OOBINLINE:
   1960 	case SO_TIMESTAMP:
   1961 	case SO_NOSIGPIPE:
   1962 	case SO_RERROR:
   1963 	case SO_ACCEPTCONN:
   1964 		error = sockopt_setint(sopt, (so->so_options & opt) ? 1 : 0);
   1965 		break;
   1966 
   1967 	case SO_TYPE:
   1968 		error = sockopt_setint(sopt, so->so_type);
   1969 		break;
   1970 
   1971 	case SO_ERROR:
   1972 		if (so->so_error == 0) {
   1973 			so->so_error = so->so_rerror;
   1974 			so->so_rerror = 0;
   1975 		}
   1976 		error = sockopt_setint(sopt, so->so_error);
   1977 		so->so_error = 0;
   1978 		break;
   1979 
   1980 	case SO_SNDBUF:
   1981 		error = sockopt_setint(sopt, so->so_snd.sb_hiwat);
   1982 		break;
   1983 
   1984 	case SO_RCVBUF:
   1985 		error = sockopt_setint(sopt, so->so_rcv.sb_hiwat);
   1986 		break;
   1987 
   1988 	case SO_SNDLOWAT:
   1989 		error = sockopt_setint(sopt, so->so_snd.sb_lowat);
   1990 		break;
   1991 
   1992 	case SO_RCVLOWAT:
   1993 		error = sockopt_setint(sopt, so->so_rcv.sb_lowat);
   1994 		break;
   1995 
   1996 	case SO_SNDTIMEO:
   1997 	case SO_RCVTIMEO:
   1998 		optval = (opt == SO_SNDTIMEO ?
   1999 		     so->so_snd.sb_timeo : so->so_rcv.sb_timeo);
   2000 
   2001 		memset(&tv, 0, sizeof(tv));
   2002 		tv.tv_sec = optval / hz;
   2003 		tv.tv_usec = (optval % hz) * tick;
   2004 
   2005 		error = sockopt_set(sopt, &tv, sizeof(tv));
   2006 		break;
   2007 
   2008 	case SO_OVERFLOWED:
   2009 		error = sockopt_setint(sopt, so->so_rcv.sb_overflowed);
   2010 		break;
   2011 
   2012 	default:
   2013 		MODULE_HOOK_CALL(uipc_socket_50_getopt1_hook,
   2014 		    (opt, so, sopt), enosys(), error);
   2015 		if (error)
   2016 			error = ENOPROTOOPT;
   2017 		break;
   2018 	}
   2019 
   2020 	return error;
   2021 }
   2022 
   2023 int
   2024 sogetopt(struct socket *so, struct sockopt *sopt)
   2025 {
   2026 	int error;
   2027 
   2028 	solock(so);
   2029 	if (sopt->sopt_level != SOL_SOCKET) {
   2030 		if (so->so_proto && so->so_proto->pr_ctloutput) {
   2031 			error = ((*so->so_proto->pr_ctloutput)
   2032 			    (PRCO_GETOPT, so, sopt));
   2033 		} else
   2034 			error = (ENOPROTOOPT);
   2035 	} else {
   2036 		error = sogetopt1(so, sopt);
   2037 	}
   2038 	sounlock(so);
   2039 	return error;
   2040 }
   2041 
   2042 /*
   2043  * alloc sockopt data buffer buffer
   2044  *	- will be released at destroy
   2045  */
   2046 static int
   2047 sockopt_alloc(struct sockopt *sopt, size_t len, km_flag_t kmflag)
   2048 {
   2049 	void *data;
   2050 
   2051 	KASSERT(sopt->sopt_size == 0);
   2052 
   2053 	if (len > sizeof(sopt->sopt_buf)) {
   2054 		data = kmem_zalloc(len, kmflag);
   2055 		if (data == NULL)
   2056 			return ENOMEM;
   2057 		sopt->sopt_data = data;
   2058 	} else
   2059 		sopt->sopt_data = sopt->sopt_buf;
   2060 
   2061 	sopt->sopt_size = len;
   2062 	return 0;
   2063 }
   2064 
   2065 /*
   2066  * initialise sockopt storage
   2067  *	- MAY sleep during allocation
   2068  */
   2069 void
   2070 sockopt_init(struct sockopt *sopt, int level, int name, size_t size)
   2071 {
   2072 
   2073 	memset(sopt, 0, sizeof(*sopt));
   2074 
   2075 	sopt->sopt_level = level;
   2076 	sopt->sopt_name = name;
   2077 	(void)sockopt_alloc(sopt, size, KM_SLEEP);
   2078 }
   2079 
   2080 /*
   2081  * destroy sockopt storage
   2082  *	- will release any held memory references
   2083  */
   2084 void
   2085 sockopt_destroy(struct sockopt *sopt)
   2086 {
   2087 
   2088 	if (sopt->sopt_data != sopt->sopt_buf)
   2089 		kmem_free(sopt->sopt_data, sopt->sopt_size);
   2090 
   2091 	memset(sopt, 0, sizeof(*sopt));
   2092 }
   2093 
   2094 /*
   2095  * set sockopt value
   2096  *	- value is copied into sockopt
   2097  *	- memory is allocated when necessary, will not sleep
   2098  */
   2099 int
   2100 sockopt_set(struct sockopt *sopt, const void *buf, size_t len)
   2101 {
   2102 	int error;
   2103 
   2104 	if (sopt->sopt_size == 0) {
   2105 		error = sockopt_alloc(sopt, len, KM_NOSLEEP);
   2106 		if (error)
   2107 			return error;
   2108 	}
   2109 
   2110 	sopt->sopt_retsize = MIN(sopt->sopt_size, len);
   2111 	if (sopt->sopt_retsize > 0) {
   2112 		memcpy(sopt->sopt_data, buf, sopt->sopt_retsize);
   2113 	}
   2114 
   2115 	return 0;
   2116 }
   2117 
   2118 /*
   2119  * common case of set sockopt integer value
   2120  */
   2121 int
   2122 sockopt_setint(struct sockopt *sopt, int val)
   2123 {
   2124 
   2125 	return sockopt_set(sopt, &val, sizeof(int));
   2126 }
   2127 
   2128 /*
   2129  * get sockopt value
   2130  *	- correct size must be given
   2131  */
   2132 int
   2133 sockopt_get(const struct sockopt *sopt, void *buf, size_t len)
   2134 {
   2135 
   2136 	if (sopt->sopt_size != len)
   2137 		return EINVAL;
   2138 
   2139 	memcpy(buf, sopt->sopt_data, len);
   2140 	return 0;
   2141 }
   2142 
   2143 /*
   2144  * common case of get sockopt integer value
   2145  */
   2146 int
   2147 sockopt_getint(const struct sockopt *sopt, int *valp)
   2148 {
   2149 
   2150 	return sockopt_get(sopt, valp, sizeof(int));
   2151 }
   2152 
   2153 /*
   2154  * set sockopt value from mbuf
   2155  *	- ONLY for legacy code
   2156  *	- mbuf is released by sockopt
   2157  *	- will not sleep
   2158  */
   2159 int
   2160 sockopt_setmbuf(struct sockopt *sopt, struct mbuf *m)
   2161 {
   2162 	size_t len;
   2163 	int error;
   2164 
   2165 	len = m_length(m);
   2166 
   2167 	if (sopt->sopt_size == 0) {
   2168 		error = sockopt_alloc(sopt, len, KM_NOSLEEP);
   2169 		if (error)
   2170 			return error;
   2171 	}
   2172 
   2173 	sopt->sopt_retsize = MIN(sopt->sopt_size, len);
   2174 	m_copydata(m, 0, sopt->sopt_retsize, sopt->sopt_data);
   2175 	m_freem(m);
   2176 
   2177 	return 0;
   2178 }
   2179 
   2180 /*
   2181  * get sockopt value into mbuf
   2182  *	- ONLY for legacy code
   2183  *	- mbuf to be released by the caller
   2184  *	- will not sleep
   2185  */
   2186 struct mbuf *
   2187 sockopt_getmbuf(const struct sockopt *sopt)
   2188 {
   2189 	struct mbuf *m;
   2190 
   2191 	if (sopt->sopt_size > MCLBYTES)
   2192 		return NULL;
   2193 
   2194 	m = m_get(M_DONTWAIT, MT_SOOPTS);
   2195 	if (m == NULL)
   2196 		return NULL;
   2197 
   2198 	if (sopt->sopt_size > MLEN) {
   2199 		MCLGET(m, M_DONTWAIT);
   2200 		if ((m->m_flags & M_EXT) == 0) {
   2201 			m_free(m);
   2202 			return NULL;
   2203 		}
   2204 	}
   2205 
   2206 	memcpy(mtod(m, void *), sopt->sopt_data, sopt->sopt_size);
   2207 	m->m_len = sopt->sopt_size;
   2208 
   2209 	return m;
   2210 }
   2211 
   2212 void
   2213 sohasoutofband(struct socket *so)
   2214 {
   2215 
   2216 	so->so_state |= SS_POLLRDBAND;
   2217 	fownsignal(so->so_pgid, SIGURG, POLL_PRI, POLLPRI|POLLRDBAND, so);
   2218 	selnotify(&so->so_rcv.sb_sel, POLLPRI | POLLRDBAND, NOTE_SUBMIT);
   2219 }
   2220 
   2221 static void
   2222 filt_sordetach(struct knote *kn)
   2223 {
   2224 	struct socket *so;
   2225 
   2226 	so = ((file_t *)kn->kn_obj)->f_socket;
   2227 	solock(so);
   2228 	selremove_knote(&so->so_rcv.sb_sel, kn);
   2229 	if (SLIST_EMPTY(&so->so_rcv.sb_sel.sel_klist))	/* XXX select/kqueue */
   2230 		so->so_rcv.sb_flags &= ~SB_KNOTE;	/* XXX internals */
   2231 	sounlock(so);
   2232 }
   2233 
   2234 /*ARGSUSED*/
   2235 static int
   2236 filt_soread(struct knote *kn, long hint)
   2237 {
   2238 	struct socket *so;
   2239 	int rv;
   2240 
   2241 	so = ((file_t *)kn->kn_obj)->f_socket;
   2242 	if (hint != NOTE_SUBMIT)
   2243 		solock(so);
   2244 	kn->kn_data = so->so_rcv.sb_cc;
   2245 	if (so->so_state & SS_CANTRCVMORE) {
   2246 		kn->kn_flags |= EV_EOF;
   2247 		kn->kn_fflags = so->so_error;
   2248 		rv = 1;
   2249 	} else if (so->so_error || so->so_rerror)
   2250 		rv = 1;
   2251 	else if (kn->kn_sfflags & NOTE_LOWAT)
   2252 		rv = (kn->kn_data >= kn->kn_sdata);
   2253 	else
   2254 		rv = (kn->kn_data >= so->so_rcv.sb_lowat);
   2255 	if (hint != NOTE_SUBMIT)
   2256 		sounlock(so);
   2257 	return rv;
   2258 }
   2259 
   2260 static void
   2261 filt_sowdetach(struct knote *kn)
   2262 {
   2263 	struct socket *so;
   2264 
   2265 	so = ((file_t *)kn->kn_obj)->f_socket;
   2266 	solock(so);
   2267 	selremove_knote(&so->so_snd.sb_sel, kn);
   2268 	if (SLIST_EMPTY(&so->so_snd.sb_sel.sel_klist))	/* XXX select/kqueue */
   2269 		so->so_snd.sb_flags &= ~SB_KNOTE;	/* XXX internals */
   2270 	sounlock(so);
   2271 }
   2272 
   2273 /*ARGSUSED*/
   2274 static int
   2275 filt_sowrite(struct knote *kn, long hint)
   2276 {
   2277 	struct socket *so;
   2278 	int rv;
   2279 
   2280 	so = ((file_t *)kn->kn_obj)->f_socket;
   2281 	if (hint != NOTE_SUBMIT)
   2282 		solock(so);
   2283 	kn->kn_data = sbspace(&so->so_snd);
   2284 	if (so->so_state & SS_CANTSENDMORE) {
   2285 		kn->kn_flags |= EV_EOF;
   2286 		kn->kn_fflags = so->so_error;
   2287 		rv = 1;
   2288 	} else if (so->so_error)
   2289 		rv = 1;
   2290 	else if (((so->so_state & SS_ISCONNECTED) == 0) &&
   2291 	    (so->so_proto->pr_flags & PR_CONNREQUIRED))
   2292 		rv = 0;
   2293 	else if (kn->kn_sfflags & NOTE_LOWAT)
   2294 		rv = (kn->kn_data >= kn->kn_sdata);
   2295 	else
   2296 		rv = (kn->kn_data >= so->so_snd.sb_lowat);
   2297 	if (hint != NOTE_SUBMIT)
   2298 		sounlock(so);
   2299 	return rv;
   2300 }
   2301 
   2302 /*ARGSUSED*/
   2303 static int
   2304 filt_solisten(struct knote *kn, long hint)
   2305 {
   2306 	struct socket *so;
   2307 	int rv;
   2308 
   2309 	so = ((file_t *)kn->kn_obj)->f_socket;
   2310 
   2311 	/*
   2312 	 * Set kn_data to number of incoming connections, not
   2313 	 * counting partial (incomplete) connections.
   2314 	 */
   2315 	if (hint != NOTE_SUBMIT)
   2316 		solock(so);
   2317 	kn->kn_data = so->so_qlen;
   2318 	rv = (kn->kn_data > 0);
   2319 	if (hint != NOTE_SUBMIT)
   2320 		sounlock(so);
   2321 	return rv;
   2322 }
   2323 
   2324 static const struct filterops solisten_filtops = {
   2325 	.f_flags = FILTEROP_ISFD,
   2326 	.f_attach = NULL,
   2327 	.f_detach = filt_sordetach,
   2328 	.f_event = filt_solisten,
   2329 };
   2330 
   2331 static const struct filterops soread_filtops = {
   2332 	.f_flags = FILTEROP_ISFD,
   2333 	.f_attach = NULL,
   2334 	.f_detach = filt_sordetach,
   2335 	.f_event = filt_soread,
   2336 };
   2337 
   2338 static const struct filterops sowrite_filtops = {
   2339 	.f_flags = FILTEROP_ISFD,
   2340 	.f_attach = NULL,
   2341 	.f_detach = filt_sowdetach,
   2342 	.f_event = filt_sowrite,
   2343 };
   2344 
   2345 int
   2346 soo_kqfilter(struct file *fp, struct knote *kn)
   2347 {
   2348 	struct socket *so;
   2349 	struct sockbuf *sb;
   2350 
   2351 	so = ((file_t *)kn->kn_obj)->f_socket;
   2352 	solock(so);
   2353 	switch (kn->kn_filter) {
   2354 	case EVFILT_READ:
   2355 		if (so->so_options & SO_ACCEPTCONN)
   2356 			kn->kn_fop = &solisten_filtops;
   2357 		else
   2358 			kn->kn_fop = &soread_filtops;
   2359 		sb = &so->so_rcv;
   2360 		break;
   2361 	case EVFILT_WRITE:
   2362 		kn->kn_fop = &sowrite_filtops;
   2363 		sb = &so->so_snd;
   2364 		break;
   2365 	default:
   2366 		sounlock(so);
   2367 		return EINVAL;
   2368 	}
   2369 	selrecord_knote(&sb->sb_sel, kn);
   2370 	sb->sb_flags |= SB_KNOTE;
   2371 	sounlock(so);
   2372 	return 0;
   2373 }
   2374 
   2375 static int
   2376 sodopoll(struct socket *so, int events)
   2377 {
   2378 	int revents;
   2379 
   2380 	revents = 0;
   2381 
   2382 	if (events & (POLLIN | POLLRDNORM))
   2383 		if (soreadable(so))
   2384 			revents |= events & (POLLIN | POLLRDNORM);
   2385 
   2386 	if (events & (POLLOUT | POLLWRNORM))
   2387 		if (sowritable(so))
   2388 			revents |= events & (POLLOUT | POLLWRNORM);
   2389 
   2390 	if (events & (POLLPRI | POLLRDBAND))
   2391 		if (so->so_state & SS_POLLRDBAND)
   2392 			revents |= events & (POLLPRI | POLLRDBAND);
   2393 
   2394 	return revents;
   2395 }
   2396 
   2397 int
   2398 sopoll(struct socket *so, int events)
   2399 {
   2400 	int revents = 0;
   2401 
   2402 #ifndef DIAGNOSTIC
   2403 	/*
   2404 	 * Do a quick, unlocked check in expectation that the socket
   2405 	 * will be ready for I/O.  Don't do this check if DIAGNOSTIC,
   2406 	 * as the solocked() assertions will fail.
   2407 	 */
   2408 	if ((revents = sodopoll(so, events)) != 0)
   2409 		return revents;
   2410 #endif
   2411 
   2412 	solock(so);
   2413 	if ((revents = sodopoll(so, events)) == 0) {
   2414 		if (events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) {
   2415 			selrecord(curlwp, &so->so_rcv.sb_sel);
   2416 			so->so_rcv.sb_flags |= SB_NOTIFY;
   2417 		}
   2418 
   2419 		if (events & (POLLOUT | POLLWRNORM)) {
   2420 			selrecord(curlwp, &so->so_snd.sb_sel);
   2421 			so->so_snd.sb_flags |= SB_NOTIFY;
   2422 		}
   2423 	}
   2424 	sounlock(so);
   2425 
   2426 	return revents;
   2427 }
   2428 
   2429 struct mbuf **
   2430 sbsavetimestamp(int opt, struct mbuf **mp)
   2431 {
   2432 	struct timeval tv;
   2433 	int error;
   2434 
   2435 	memset(&tv, 0, sizeof(tv));
   2436 	microtime(&tv);
   2437 
   2438 	MODULE_HOOK_CALL(uipc_socket_50_sbts_hook, (opt, &mp), enosys(), error);
   2439 	if (error == 0)
   2440 		return mp;
   2441 
   2442 	if (opt & SO_TIMESTAMP) {
   2443 		*mp = sbcreatecontrol(&tv, sizeof(tv),
   2444 		    SCM_TIMESTAMP, SOL_SOCKET);
   2445 		if (*mp)
   2446 			mp = &(*mp)->m_next;
   2447 	}
   2448 	return mp;
   2449 }
   2450 
   2451 
   2452 #include <sys/sysctl.h>
   2453 
   2454 static int sysctl_kern_somaxkva(SYSCTLFN_PROTO);
   2455 static int sysctl_kern_sbmax(SYSCTLFN_PROTO);
   2456 
   2457 /*
   2458  * sysctl helper routine for kern.somaxkva.  ensures that the given
   2459  * value is not too small.
   2460  * (XXX should we maybe make sure it's not too large as well?)
   2461  */
   2462 static int
   2463 sysctl_kern_somaxkva(SYSCTLFN_ARGS)
   2464 {
   2465 	int error, new_somaxkva;
   2466 	struct sysctlnode node;
   2467 
   2468 	new_somaxkva = somaxkva;
   2469 	node = *rnode;
   2470 	node.sysctl_data = &new_somaxkva;
   2471 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
   2472 	if (error || newp == NULL)
   2473 		return error;
   2474 
   2475 	if (new_somaxkva < (16 * 1024 * 1024)) /* sanity */
   2476 		return EINVAL;
   2477 
   2478 	mutex_enter(&so_pendfree_lock);
   2479 	somaxkva = new_somaxkva;
   2480 	cv_broadcast(&socurkva_cv);
   2481 	mutex_exit(&so_pendfree_lock);
   2482 
   2483 	return error;
   2484 }
   2485 
   2486 /*
   2487  * sysctl helper routine for kern.sbmax. Basically just ensures that
   2488  * any new value is not too small.
   2489  */
   2490 static int
   2491 sysctl_kern_sbmax(SYSCTLFN_ARGS)
   2492 {
   2493 	int error, new_sbmax;
   2494 	struct sysctlnode node;
   2495 
   2496 	new_sbmax = sb_max;
   2497 	node = *rnode;
   2498 	node.sysctl_data = &new_sbmax;
   2499 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
   2500 	if (error || newp == NULL)
   2501 		return error;
   2502 
   2503 	KERNEL_LOCK(1, NULL);
   2504 	error = sb_max_set(new_sbmax);
   2505 	KERNEL_UNLOCK_ONE(NULL);
   2506 
   2507 	return error;
   2508 }
   2509 
   2510 /*
   2511  * sysctl helper routine for kern.sooptions. Ensures that only allowed
   2512  * options can be set.
   2513  */
   2514 static int
   2515 sysctl_kern_sooptions(SYSCTLFN_ARGS)
   2516 {
   2517 	int error, new_options;
   2518 	struct sysctlnode node;
   2519 
   2520 	new_options = sooptions;
   2521 	node = *rnode;
   2522 	node.sysctl_data = &new_options;
   2523 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
   2524 	if (error || newp == NULL)
   2525 		return error;
   2526 
   2527 	if (new_options & ~SO_DEFOPTS)
   2528 		return EINVAL;
   2529 
   2530 	sooptions = new_options;
   2531 
   2532 	return 0;
   2533 }
   2534 
   2535 static void
   2536 sysctl_kern_socket_setup(void)
   2537 {
   2538 
   2539 	KASSERT(socket_sysctllog == NULL);
   2540 
   2541 	sysctl_createv(&socket_sysctllog, 0, NULL, NULL,
   2542 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2543 		       CTLTYPE_INT, "somaxkva",
   2544 		       SYSCTL_DESCR("Maximum amount of kernel memory to be "
   2545 		                    "used for socket buffers"),
   2546 		       sysctl_kern_somaxkva, 0, NULL, 0,
   2547 		       CTL_KERN, KERN_SOMAXKVA, CTL_EOL);
   2548 
   2549 	sysctl_createv(&socket_sysctllog, 0, NULL, NULL,
   2550 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2551 		       CTLTYPE_BOOL, "sofixedbuf",
   2552 		       SYSCTL_DESCR("Prevent scaling of fixed socket buffers"),
   2553 		       NULL, 0, &sofixedbuf, 0,
   2554 		       CTL_KERN, KERN_SOFIXEDBUF, CTL_EOL);
   2555 
   2556 	sysctl_createv(&socket_sysctllog, 0, NULL, NULL,
   2557 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2558 		       CTLTYPE_INT, "sbmax",
   2559 		       SYSCTL_DESCR("Maximum socket buffer size"),
   2560 		       sysctl_kern_sbmax, 0, NULL, 0,
   2561 		       CTL_KERN, KERN_SBMAX, CTL_EOL);
   2562 
   2563 	sysctl_createv(&socket_sysctllog, 0, NULL, NULL,
   2564 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2565 		       CTLTYPE_INT, "sooptions",
   2566 		       SYSCTL_DESCR("Default socket options"),
   2567 		       sysctl_kern_sooptions, 0, NULL, 0,
   2568 		       CTL_KERN, CTL_CREATE, CTL_EOL);
   2569 }
   2570