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uipc_socket.c revision 1.115.2.3
      1 /*	$NetBSD: uipc_socket.c,v 1.115.2.3 2005/12/31 11:34:26 yamt Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2002 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.
      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  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the NetBSD
     21  *	Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 /*
     40  * Copyright (c) 1982, 1986, 1988, 1990, 1993
     41  *	The Regents of the University of California.  All rights reserved.
     42  *
     43  * Redistribution and use in source and binary forms, with or without
     44  * modification, are permitted provided that the following conditions
     45  * are met:
     46  * 1. Redistributions of source code must retain the above copyright
     47  *    notice, this list of conditions and the following disclaimer.
     48  * 2. Redistributions in binary form must reproduce the above copyright
     49  *    notice, this list of conditions and the following disclaimer in the
     50  *    documentation and/or other materials provided with the distribution.
     51  * 3. Neither the name of the University nor the names of its contributors
     52  *    may be used to endorse or promote products derived from this software
     53  *    without specific prior written permission.
     54  *
     55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     65  * SUCH DAMAGE.
     66  *
     67  *	@(#)uipc_socket.c	8.6 (Berkeley) 5/2/95
     68  */
     69 
     70 #include <sys/cdefs.h>
     71 __KERNEL_RCSID(0, "$NetBSD: uipc_socket.c,v 1.115.2.3 2005/12/31 11:34:26 yamt Exp $");
     72 
     73 #include "opt_sock_counters.h"
     74 #include "opt_sosend_loan.h"
     75 #include "opt_mbuftrace.h"
     76 #include "opt_somaxkva.h"
     77 
     78 #include <sys/param.h>
     79 #include <sys/systm.h>
     80 #include <sys/proc.h>
     81 #include <sys/file.h>
     82 #include <sys/malloc.h>
     83 #include <sys/mbuf.h>
     84 #include <sys/domain.h>
     85 #include <sys/kernel.h>
     86 #include <sys/protosw.h>
     87 #include <sys/socket.h>
     88 #include <sys/socketvar.h>
     89 #include <sys/signalvar.h>
     90 #include <sys/resourcevar.h>
     91 #include <sys/pool.h>
     92 #include <sys/event.h>
     93 #include <sys/poll.h>
     94 
     95 #include <uvm/uvm.h>
     96 
     97 POOL_INIT(socket_pool, sizeof(struct socket), 0, 0, 0, "sockpl", NULL);
     98 
     99 MALLOC_DEFINE(M_SOOPTS, "soopts", "socket options");
    100 MALLOC_DEFINE(M_SONAME, "soname", "socket name");
    101 
    102 extern int	somaxconn;			/* patchable (XXX sysctl) */
    103 int		somaxconn = SOMAXCONN;
    104 
    105 #ifdef SOSEND_COUNTERS
    106 #include <sys/device.h>
    107 
    108 static struct evcnt sosend_loan_big = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
    109     NULL, "sosend", "loan big");
    110 static struct evcnt sosend_copy_big = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
    111     NULL, "sosend", "copy big");
    112 static struct evcnt sosend_copy_small = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
    113     NULL, "sosend", "copy small");
    114 static struct evcnt sosend_kvalimit = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
    115     NULL, "sosend", "kva limit");
    116 
    117 #define	SOSEND_COUNTER_INCR(ev)		(ev)->ev_count++
    118 
    119 EVCNT_ATTACH_STATIC(sosend_loan_big);
    120 EVCNT_ATTACH_STATIC(sosend_copy_big);
    121 EVCNT_ATTACH_STATIC(sosend_copy_small);
    122 EVCNT_ATTACH_STATIC(sosend_kvalimit);
    123 #else
    124 
    125 #define	SOSEND_COUNTER_INCR(ev)		/* nothing */
    126 
    127 #endif /* SOSEND_COUNTERS */
    128 
    129 void
    130 soinit(void)
    131 {
    132 
    133 	/* Set the initial adjusted socket buffer size. */
    134 	if (sb_max_set(sb_max))
    135 		panic("bad initial sb_max value: %lu", sb_max);
    136 
    137 }
    138 
    139 #ifdef SOSEND_NO_LOAN
    140 int use_sosend_loan = 0;
    141 #else
    142 int use_sosend_loan = 1;
    143 #endif
    144 
    145 static struct simplelock so_pendfree_slock = SIMPLELOCK_INITIALIZER;
    146 static struct mbuf *so_pendfree;
    147 
    148 #ifndef SOMAXKVA
    149 #define	SOMAXKVA (16 * 1024 * 1024)
    150 #endif
    151 int somaxkva = SOMAXKVA;
    152 static int socurkva;
    153 static int sokvawaiters;
    154 
    155 #define	SOCK_LOAN_THRESH	4096
    156 #define	SOCK_LOAN_CHUNK		65536
    157 
    158 static size_t sodopendfree(struct socket *);
    159 static size_t sodopendfreel(struct socket *);
    160 
    161 static vsize_t
    162 sokvareserve(struct socket *so, vsize_t len)
    163 {
    164 	int s;
    165 	int error;
    166 
    167 	s = splvm();
    168 	simple_lock(&so_pendfree_slock);
    169 	while (socurkva + len > somaxkva) {
    170 		size_t freed;
    171 
    172 		/*
    173 		 * try to do pendfree.
    174 		 */
    175 
    176 		freed = sodopendfreel(so);
    177 
    178 		/*
    179 		 * if some kva was freed, try again.
    180 		 */
    181 
    182 		if (freed)
    183 			continue;
    184 
    185 		SOSEND_COUNTER_INCR(&sosend_kvalimit);
    186 		sokvawaiters++;
    187 		error = ltsleep(&socurkva, PVM | PCATCH, "sokva", 0,
    188 		    &so_pendfree_slock);
    189 		sokvawaiters--;
    190 		if (error) {
    191 			len = 0;
    192 			break;
    193 		}
    194 	}
    195 	socurkva += len;
    196 	simple_unlock(&so_pendfree_slock);
    197 	splx(s);
    198 	return len;
    199 }
    200 
    201 static void
    202 sokvaunreserve(vsize_t len)
    203 {
    204 	int s;
    205 
    206 	s = splvm();
    207 	simple_lock(&so_pendfree_slock);
    208 	socurkva -= len;
    209 	if (sokvawaiters)
    210 		wakeup(&socurkva);
    211 	simple_unlock(&so_pendfree_slock);
    212 	splx(s);
    213 }
    214 
    215 /*
    216  * sokvaalloc: allocate kva for loan.
    217  */
    218 
    219 vaddr_t
    220 sokvaalloc(vsize_t len, struct socket *so)
    221 {
    222 	vaddr_t lva;
    223 
    224 	/*
    225 	 * reserve kva.
    226 	 */
    227 
    228 	if (sokvareserve(so, len) == 0)
    229 		return 0;
    230 
    231 	/*
    232 	 * allocate kva.
    233 	 */
    234 
    235 	lva = uvm_km_alloc(kernel_map, len, 0, UVM_KMF_VAONLY | UVM_KMF_WAITVA);
    236 	if (lva == 0) {
    237 		sokvaunreserve(len);
    238 		return (0);
    239 	}
    240 
    241 	return lva;
    242 }
    243 
    244 /*
    245  * sokvafree: free kva for loan.
    246  */
    247 
    248 void
    249 sokvafree(vaddr_t sva, vsize_t len)
    250 {
    251 
    252 	/*
    253 	 * free kva.
    254 	 */
    255 
    256 	uvm_km_free(kernel_map, sva, len, UVM_KMF_VAONLY);
    257 
    258 	/*
    259 	 * unreserve kva.
    260 	 */
    261 
    262 	sokvaunreserve(len);
    263 }
    264 
    265 static void
    266 sodoloanfree(struct vm_page **pgs, caddr_t buf, size_t size)
    267 {
    268 	vaddr_t va, sva, eva;
    269 	vsize_t len;
    270 	paddr_t pa;
    271 	int i, npgs;
    272 
    273 	eva = round_page((vaddr_t) buf + size);
    274 	sva = trunc_page((vaddr_t) buf);
    275 	len = eva - sva;
    276 	npgs = len >> PAGE_SHIFT;
    277 
    278 	if (__predict_false(pgs == NULL)) {
    279 		pgs = alloca(npgs * sizeof(*pgs));
    280 
    281 		for (i = 0, va = sva; va < eva; i++, va += PAGE_SIZE) {
    282 			if (pmap_extract(pmap_kernel(), va, &pa) == FALSE)
    283 				panic("sodoloanfree: va 0x%lx not mapped", va);
    284 			pgs[i] = PHYS_TO_VM_PAGE(pa);
    285 		}
    286 	}
    287 
    288 	pmap_kremove(sva, len);
    289 	pmap_update(pmap_kernel());
    290 	uvm_unloan(pgs, npgs, UVM_LOAN_TOPAGE);
    291 	sokvafree(sva, len);
    292 }
    293 
    294 static size_t
    295 sodopendfree(struct socket *so)
    296 {
    297 	int s;
    298 	size_t rv;
    299 
    300 	s = splvm();
    301 	simple_lock(&so_pendfree_slock);
    302 	rv = sodopendfreel(so);
    303 	simple_unlock(&so_pendfree_slock);
    304 	splx(s);
    305 
    306 	return rv;
    307 }
    308 
    309 /*
    310  * sodopendfreel: free mbufs on "pendfree" list.
    311  * unlock and relock so_pendfree_slock when freeing mbufs.
    312  *
    313  * => called with so_pendfree_slock held.
    314  * => called at splvm.
    315  */
    316 
    317 static size_t
    318 sodopendfreel(struct socket *so)
    319 {
    320 	size_t rv = 0;
    321 
    322 	LOCK_ASSERT(simple_lock_held(&so_pendfree_slock));
    323 
    324 	for (;;) {
    325 		struct mbuf *m;
    326 		struct mbuf *next;
    327 
    328 		m = so_pendfree;
    329 		if (m == NULL)
    330 			break;
    331 		so_pendfree = NULL;
    332 		simple_unlock(&so_pendfree_slock);
    333 		/* XXX splx */
    334 
    335 		for (; m != NULL; m = next) {
    336 			next = m->m_next;
    337 
    338 			rv += m->m_ext.ext_size;
    339 			sodoloanfree((m->m_flags & M_EXT_PAGES) ?
    340 			    m->m_ext.ext_pgs : NULL, m->m_ext.ext_buf,
    341 			    m->m_ext.ext_size);
    342 			pool_cache_put(&mbpool_cache, m);
    343 		}
    344 
    345 		/* XXX splvm */
    346 		simple_lock(&so_pendfree_slock);
    347 	}
    348 
    349 	return (rv);
    350 }
    351 
    352 void
    353 soloanfree(struct mbuf *m, caddr_t buf, size_t size, void *arg)
    354 {
    355 	int s;
    356 
    357 	if (m == NULL) {
    358 
    359 		/*
    360 		 * called from MEXTREMOVE.
    361 		 */
    362 
    363 		sodoloanfree(NULL, buf, size);
    364 		return;
    365 	}
    366 
    367 	/*
    368 	 * postpone freeing mbuf.
    369 	 *
    370 	 * we can't do it in interrupt context
    371 	 * because we need to put kva back to kernel_map.
    372 	 */
    373 
    374 	s = splvm();
    375 	simple_lock(&so_pendfree_slock);
    376 	m->m_next = so_pendfree;
    377 	so_pendfree = m;
    378 	if (sokvawaiters)
    379 		wakeup(&socurkva);
    380 	simple_unlock(&so_pendfree_slock);
    381 	splx(s);
    382 }
    383 
    384 static long
    385 sosend_loan(struct socket *so, struct uio *uio, struct mbuf *m, long space)
    386 {
    387 	struct iovec *iov = uio->uio_iov;
    388 	vaddr_t sva, eva;
    389 	vsize_t len;
    390 	vaddr_t lva, va;
    391 	int npgs, i, error;
    392 
    393 	if (VMSPACE_IS_KERNEL(uio->uio_vmspace))
    394 		return (0);
    395 
    396 	if (iov->iov_len < (size_t) space)
    397 		space = iov->iov_len;
    398 	if (space > SOCK_LOAN_CHUNK)
    399 		space = SOCK_LOAN_CHUNK;
    400 
    401 	eva = round_page((vaddr_t) iov->iov_base + space);
    402 	sva = trunc_page((vaddr_t) iov->iov_base);
    403 	len = eva - sva;
    404 	npgs = len >> PAGE_SHIFT;
    405 
    406 	/* XXX KDASSERT */
    407 	KASSERT(npgs <= M_EXT_MAXPAGES);
    408 
    409 	lva = sokvaalloc(len, so);
    410 	if (lva == 0)
    411 		return 0;
    412 
    413 	error = uvm_loan(&uio->uio_vmspace->vm_map, sva, len,
    414 	    m->m_ext.ext_pgs, UVM_LOAN_TOPAGE);
    415 	if (error) {
    416 		sokvafree(lva, len);
    417 		return (0);
    418 	}
    419 
    420 	for (i = 0, va = lva; i < npgs; i++, va += PAGE_SIZE)
    421 		pmap_kenter_pa(va, VM_PAGE_TO_PHYS(m->m_ext.ext_pgs[i]),
    422 		    VM_PROT_READ);
    423 	pmap_update(pmap_kernel());
    424 
    425 	lva += (vaddr_t) iov->iov_base & PAGE_MASK;
    426 
    427 	MEXTADD(m, (caddr_t) lva, space, M_MBUF, soloanfree, so);
    428 	m->m_flags |= M_EXT_PAGES | M_EXT_ROMAP;
    429 
    430 	uio->uio_resid -= space;
    431 	/* uio_offset not updated, not set/used for write(2) */
    432 	uio->uio_iov->iov_base = (caddr_t) uio->uio_iov->iov_base + space;
    433 	uio->uio_iov->iov_len -= space;
    434 	if (uio->uio_iov->iov_len == 0) {
    435 		uio->uio_iov++;
    436 		uio->uio_iovcnt--;
    437 	}
    438 
    439 	return (space);
    440 }
    441 
    442 /*
    443  * Socket operation routines.
    444  * These routines are called by the routines in
    445  * sys_socket.c or from a system process, and
    446  * implement the semantics of socket operations by
    447  * switching out to the protocol specific routines.
    448  */
    449 /*ARGSUSED*/
    450 int
    451 socreate(int dom, struct socket **aso, int type, int proto, struct lwp *l)
    452 {
    453 	const struct protosw	*prp;
    454 	struct socket	*so;
    455 	uid_t		uid;
    456 	int		error, s;
    457 
    458 	if (proto)
    459 		prp = pffindproto(dom, proto, type);
    460 	else
    461 		prp = pffindtype(dom, type);
    462 	if (prp == 0 || prp->pr_usrreq == 0)
    463 		return (EPROTONOSUPPORT);
    464 	if (prp->pr_type != type)
    465 		return (EPROTOTYPE);
    466 	s = splsoftnet();
    467 	so = pool_get(&socket_pool, PR_WAITOK);
    468 	memset((caddr_t)so, 0, sizeof(*so));
    469 	TAILQ_INIT(&so->so_q0);
    470 	TAILQ_INIT(&so->so_q);
    471 	so->so_type = type;
    472 	so->so_proto = prp;
    473 	so->so_send = sosend;
    474 	so->so_receive = soreceive;
    475 #ifdef MBUFTRACE
    476 	so->so_rcv.sb_mowner = &prp->pr_domain->dom_mowner;
    477 	so->so_snd.sb_mowner = &prp->pr_domain->dom_mowner;
    478 	so->so_mowner = &prp->pr_domain->dom_mowner;
    479 #endif
    480 	if (l != NULL) {
    481 		uid = l->l_proc->p_ucred->cr_uid;
    482 	} else {
    483 		uid = 0;
    484 	}
    485 	so->so_uidinfo = uid_find(uid);
    486 	error = (*prp->pr_usrreq)(so, PRU_ATTACH, (struct mbuf *)0,
    487 	    (struct mbuf *)(long)proto, (struct mbuf *)0, l);
    488 	if (error) {
    489 		so->so_state |= SS_NOFDREF;
    490 		sofree(so);
    491 		splx(s);
    492 		return (error);
    493 	}
    494 	splx(s);
    495 	*aso = so;
    496 	return (0);
    497 }
    498 
    499 int
    500 sobind(struct socket *so, struct mbuf *nam, struct lwp *l)
    501 {
    502 	int	s, error;
    503 
    504 	s = splsoftnet();
    505 	error = (*so->so_proto->pr_usrreq)(so, PRU_BIND, (struct mbuf *)0,
    506 	    nam, (struct mbuf *)0, l);
    507 	splx(s);
    508 	return (error);
    509 }
    510 
    511 int
    512 solisten(struct socket *so, int backlog)
    513 {
    514 	int	s, error;
    515 
    516 	s = splsoftnet();
    517 	error = (*so->so_proto->pr_usrreq)(so, PRU_LISTEN, (struct mbuf *)0,
    518 	    (struct mbuf *)0, (struct mbuf *)0, (struct lwp *)0);
    519 	if (error) {
    520 		splx(s);
    521 		return (error);
    522 	}
    523 	if (TAILQ_EMPTY(&so->so_q))
    524 		so->so_options |= SO_ACCEPTCONN;
    525 	if (backlog < 0)
    526 		backlog = 0;
    527 	so->so_qlimit = min(backlog, somaxconn);
    528 	splx(s);
    529 	return (0);
    530 }
    531 
    532 void
    533 sofree(struct socket *so)
    534 {
    535 
    536 	if (so->so_pcb || (so->so_state & SS_NOFDREF) == 0)
    537 		return;
    538 	if (so->so_head) {
    539 		/*
    540 		 * We must not decommission a socket that's on the accept(2)
    541 		 * queue.  If we do, then accept(2) may hang after select(2)
    542 		 * indicated that the listening socket was ready.
    543 		 */
    544 		if (!soqremque(so, 0))
    545 			return;
    546 	}
    547 	if (so->so_rcv.sb_hiwat)
    548 		(void)chgsbsize(so->so_uidinfo, &so->so_rcv.sb_hiwat, 0,
    549 		    RLIM_INFINITY);
    550 	if (so->so_snd.sb_hiwat)
    551 		(void)chgsbsize(so->so_uidinfo, &so->so_snd.sb_hiwat, 0,
    552 		    RLIM_INFINITY);
    553 	sbrelease(&so->so_snd, so);
    554 	sorflush(so);
    555 	pool_put(&socket_pool, so);
    556 }
    557 
    558 /*
    559  * Close a socket on last file table reference removal.
    560  * Initiate disconnect if connected.
    561  * Free socket when disconnect complete.
    562  */
    563 int
    564 soclose(struct socket *so)
    565 {
    566 	struct socket	*so2;
    567 	int		s, error;
    568 
    569 	error = 0;
    570 	s = splsoftnet();		/* conservative */
    571 	if (so->so_options & SO_ACCEPTCONN) {
    572 		while ((so2 = TAILQ_FIRST(&so->so_q0)) != 0) {
    573 			(void) soqremque(so2, 0);
    574 			(void) soabort(so2);
    575 		}
    576 		while ((so2 = TAILQ_FIRST(&so->so_q)) != 0) {
    577 			(void) soqremque(so2, 1);
    578 			(void) soabort(so2);
    579 		}
    580 	}
    581 	if (so->so_pcb == 0)
    582 		goto discard;
    583 	if (so->so_state & SS_ISCONNECTED) {
    584 		if ((so->so_state & SS_ISDISCONNECTING) == 0) {
    585 			error = sodisconnect(so);
    586 			if (error)
    587 				goto drop;
    588 		}
    589 		if (so->so_options & SO_LINGER) {
    590 			if ((so->so_state & SS_ISDISCONNECTING) &&
    591 			    (so->so_state & SS_NBIO))
    592 				goto drop;
    593 			while (so->so_state & SS_ISCONNECTED) {
    594 				error = tsleep((caddr_t)&so->so_timeo,
    595 					       PSOCK | PCATCH, netcls,
    596 					       so->so_linger * hz);
    597 				if (error)
    598 					break;
    599 			}
    600 		}
    601 	}
    602  drop:
    603 	if (so->so_pcb) {
    604 		int error2 = (*so->so_proto->pr_usrreq)(so, PRU_DETACH,
    605 		    (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0,
    606 		    (struct lwp *)0);
    607 		if (error == 0)
    608 			error = error2;
    609 	}
    610  discard:
    611 	if (so->so_state & SS_NOFDREF)
    612 		panic("soclose: NOFDREF");
    613 	so->so_state |= SS_NOFDREF;
    614 	sofree(so);
    615 	splx(s);
    616 	return (error);
    617 }
    618 
    619 /*
    620  * Must be called at splsoftnet...
    621  */
    622 int
    623 soabort(struct socket *so)
    624 {
    625 
    626 	return (*so->so_proto->pr_usrreq)(so, PRU_ABORT, (struct mbuf *)0,
    627 	    (struct mbuf *)0, (struct mbuf *)0, (struct lwp *)0);
    628 }
    629 
    630 int
    631 soaccept(struct socket *so, struct mbuf *nam)
    632 {
    633 	int	s, error;
    634 
    635 	error = 0;
    636 	s = splsoftnet();
    637 	if ((so->so_state & SS_NOFDREF) == 0)
    638 		panic("soaccept: !NOFDREF");
    639 	so->so_state &= ~SS_NOFDREF;
    640 	if ((so->so_state & SS_ISDISCONNECTED) == 0 ||
    641 	    (so->so_proto->pr_flags & PR_ABRTACPTDIS) == 0)
    642 		error = (*so->so_proto->pr_usrreq)(so, PRU_ACCEPT,
    643 		    (struct mbuf *)0, nam, (struct mbuf *)0, (struct lwp *)0);
    644 	else
    645 		error = ECONNABORTED;
    646 
    647 	splx(s);
    648 	return (error);
    649 }
    650 
    651 int
    652 soconnect(struct socket *so, struct mbuf *nam, struct lwp *l)
    653 {
    654 	int		s, error;
    655 
    656 	if (so->so_options & SO_ACCEPTCONN)
    657 		return (EOPNOTSUPP);
    658 	s = splsoftnet();
    659 	/*
    660 	 * If protocol is connection-based, can only connect once.
    661 	 * Otherwise, if connected, try to disconnect first.
    662 	 * This allows user to disconnect by connecting to, e.g.,
    663 	 * a null address.
    664 	 */
    665 	if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
    666 	    ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
    667 	    (error = sodisconnect(so))))
    668 		error = EISCONN;
    669 	else
    670 		error = (*so->so_proto->pr_usrreq)(so, PRU_CONNECT,
    671 		    (struct mbuf *)0, nam, (struct mbuf *)0, l);
    672 	splx(s);
    673 	return (error);
    674 }
    675 
    676 int
    677 soconnect2(struct socket *so1, struct socket *so2)
    678 {
    679 	int	s, error;
    680 
    681 	s = splsoftnet();
    682 	error = (*so1->so_proto->pr_usrreq)(so1, PRU_CONNECT2,
    683 	    (struct mbuf *)0, (struct mbuf *)so2, (struct mbuf *)0,
    684 	    (struct lwp *)0);
    685 	splx(s);
    686 	return (error);
    687 }
    688 
    689 int
    690 sodisconnect(struct socket *so)
    691 {
    692 	int	s, error;
    693 
    694 	s = splsoftnet();
    695 	if ((so->so_state & SS_ISCONNECTED) == 0) {
    696 		error = ENOTCONN;
    697 		goto bad;
    698 	}
    699 	if (so->so_state & SS_ISDISCONNECTING) {
    700 		error = EALREADY;
    701 		goto bad;
    702 	}
    703 	error = (*so->so_proto->pr_usrreq)(so, PRU_DISCONNECT,
    704 	    (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0,
    705 	    (struct lwp *)0);
    706  bad:
    707 	splx(s);
    708 	sodopendfree(so);
    709 	return (error);
    710 }
    711 
    712 #define	SBLOCKWAIT(f)	(((f) & MSG_DONTWAIT) ? M_NOWAIT : M_WAITOK)
    713 /*
    714  * Send on a socket.
    715  * If send must go all at once and message is larger than
    716  * send buffering, then hard error.
    717  * Lock against other senders.
    718  * If must go all at once and not enough room now, then
    719  * inform user that this would block and do nothing.
    720  * Otherwise, if nonblocking, send as much as possible.
    721  * The data to be sent is described by "uio" if nonzero,
    722  * otherwise by the mbuf chain "top" (which must be null
    723  * if uio is not).  Data provided in mbuf chain must be small
    724  * enough to send all at once.
    725  *
    726  * Returns nonzero on error, timeout or signal; callers
    727  * must check for short counts if EINTR/ERESTART are returned.
    728  * Data and control buffers are freed on return.
    729  */
    730 int
    731 sosend(struct socket *so, struct mbuf *addr, struct uio *uio, struct mbuf *top,
    732 	struct mbuf *control, int flags, struct lwp *l)
    733 {
    734 	struct mbuf	**mp, *m;
    735 	struct proc	*p;
    736 	long		space, len, resid, clen, mlen;
    737 	int		error, s, dontroute, atomic;
    738 
    739 	p = l->l_proc;
    740 	sodopendfree(so);
    741 
    742 	clen = 0;
    743 	atomic = sosendallatonce(so) || top;
    744 	if (uio)
    745 		resid = uio->uio_resid;
    746 	else
    747 		resid = top->m_pkthdr.len;
    748 	/*
    749 	 * In theory resid should be unsigned.
    750 	 * However, space must be signed, as it might be less than 0
    751 	 * if we over-committed, and we must use a signed comparison
    752 	 * of space and resid.  On the other hand, a negative resid
    753 	 * causes us to loop sending 0-length segments to the protocol.
    754 	 */
    755 	if (resid < 0) {
    756 		error = EINVAL;
    757 		goto out;
    758 	}
    759 	dontroute =
    760 	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
    761 	    (so->so_proto->pr_flags & PR_ATOMIC);
    762 	if (p)
    763 		p->p_stats->p_ru.ru_msgsnd++;
    764 	if (control)
    765 		clen = control->m_len;
    766 #define	snderr(errno)	{ error = errno; splx(s); goto release; }
    767 
    768  restart:
    769 	if ((error = sblock(&so->so_snd, SBLOCKWAIT(flags))) != 0)
    770 		goto out;
    771 	do {
    772 		s = splsoftnet();
    773 		if (so->so_state & SS_CANTSENDMORE)
    774 			snderr(EPIPE);
    775 		if (so->so_error) {
    776 			error = so->so_error;
    777 			so->so_error = 0;
    778 			splx(s);
    779 			goto release;
    780 		}
    781 		if ((so->so_state & SS_ISCONNECTED) == 0) {
    782 			if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
    783 				if ((so->so_state & SS_ISCONFIRMING) == 0 &&
    784 				    !(resid == 0 && clen != 0))
    785 					snderr(ENOTCONN);
    786 			} else if (addr == 0)
    787 				snderr(EDESTADDRREQ);
    788 		}
    789 		space = sbspace(&so->so_snd);
    790 		if (flags & MSG_OOB)
    791 			space += 1024;
    792 		if ((atomic && resid > so->so_snd.sb_hiwat) ||
    793 		    clen > so->so_snd.sb_hiwat)
    794 			snderr(EMSGSIZE);
    795 		if (space < resid + clen &&
    796 		    (atomic || space < so->so_snd.sb_lowat || space < clen)) {
    797 			if (so->so_state & SS_NBIO)
    798 				snderr(EWOULDBLOCK);
    799 			sbunlock(&so->so_snd);
    800 			error = sbwait(&so->so_snd);
    801 			splx(s);
    802 			if (error)
    803 				goto out;
    804 			goto restart;
    805 		}
    806 		splx(s);
    807 		mp = &top;
    808 		space -= clen;
    809 		do {
    810 			if (uio == NULL) {
    811 				/*
    812 				 * Data is prepackaged in "top".
    813 				 */
    814 				resid = 0;
    815 				if (flags & MSG_EOR)
    816 					top->m_flags |= M_EOR;
    817 			} else do {
    818 				if (top == 0) {
    819 					m = m_gethdr(M_WAIT, MT_DATA);
    820 					mlen = MHLEN;
    821 					m->m_pkthdr.len = 0;
    822 					m->m_pkthdr.rcvif = (struct ifnet *)0;
    823 				} else {
    824 					m = m_get(M_WAIT, MT_DATA);
    825 					mlen = MLEN;
    826 				}
    827 				MCLAIM(m, so->so_snd.sb_mowner);
    828 				if (use_sosend_loan &&
    829 				    uio->uio_iov->iov_len >= SOCK_LOAN_THRESH &&
    830 				    space >= SOCK_LOAN_THRESH &&
    831 				    (len = sosend_loan(so, uio, m,
    832 						       space)) != 0) {
    833 					SOSEND_COUNTER_INCR(&sosend_loan_big);
    834 					space -= len;
    835 					goto have_data;
    836 				}
    837 				if (resid >= MINCLSIZE && space >= MCLBYTES) {
    838 					SOSEND_COUNTER_INCR(&sosend_copy_big);
    839 					m_clget(m, M_WAIT);
    840 					if ((m->m_flags & M_EXT) == 0)
    841 						goto nopages;
    842 					mlen = MCLBYTES;
    843 					if (atomic && top == 0) {
    844 						len = lmin(MCLBYTES - max_hdr,
    845 						    resid);
    846 						m->m_data += max_hdr;
    847 					} else
    848 						len = lmin(MCLBYTES, resid);
    849 					space -= len;
    850 				} else {
    851  nopages:
    852 					SOSEND_COUNTER_INCR(&sosend_copy_small);
    853 					len = lmin(lmin(mlen, resid), space);
    854 					space -= len;
    855 					/*
    856 					 * For datagram protocols, leave room
    857 					 * for protocol headers in first mbuf.
    858 					 */
    859 					if (atomic && top == 0 && len < mlen)
    860 						MH_ALIGN(m, len);
    861 				}
    862 				error = uiomove(mtod(m, caddr_t), (int)len,
    863 				    uio);
    864  have_data:
    865 				resid = uio->uio_resid;
    866 				m->m_len = len;
    867 				*mp = m;
    868 				top->m_pkthdr.len += len;
    869 				if (error)
    870 					goto release;
    871 				mp = &m->m_next;
    872 				if (resid <= 0) {
    873 					if (flags & MSG_EOR)
    874 						top->m_flags |= M_EOR;
    875 					break;
    876 				}
    877 			} while (space > 0 && atomic);
    878 
    879 			s = splsoftnet();
    880 
    881 			if (so->so_state & SS_CANTSENDMORE)
    882 				snderr(EPIPE);
    883 
    884 			if (dontroute)
    885 				so->so_options |= SO_DONTROUTE;
    886 			if (resid > 0)
    887 				so->so_state |= SS_MORETOCOME;
    888 			error = (*so->so_proto->pr_usrreq)(so,
    889 			    (flags & MSG_OOB) ? PRU_SENDOOB : PRU_SEND,
    890 			    top, addr, control, curlwp);	/* XXX */
    891 			if (dontroute)
    892 				so->so_options &= ~SO_DONTROUTE;
    893 			if (resid > 0)
    894 				so->so_state &= ~SS_MORETOCOME;
    895 			splx(s);
    896 
    897 			clen = 0;
    898 			control = 0;
    899 			top = 0;
    900 			mp = &top;
    901 			if (error)
    902 				goto release;
    903 		} while (resid && space > 0);
    904 	} while (resid);
    905 
    906  release:
    907 	sbunlock(&so->so_snd);
    908  out:
    909 	if (top)
    910 		m_freem(top);
    911 	if (control)
    912 		m_freem(control);
    913 	return (error);
    914 }
    915 
    916 /*
    917  * Implement receive operations on a socket.
    918  * We depend on the way that records are added to the sockbuf
    919  * by sbappend*.  In particular, each record (mbufs linked through m_next)
    920  * must begin with an address if the protocol so specifies,
    921  * followed by an optional mbuf or mbufs containing ancillary data,
    922  * and then zero or more mbufs of data.
    923  * In order to avoid blocking network interrupts for the entire time here,
    924  * we splx() while doing the actual copy to user space.
    925  * Although the sockbuf is locked, new data may still be appended,
    926  * and thus we must maintain consistency of the sockbuf during that time.
    927  *
    928  * The caller may receive the data as a single mbuf chain by supplying
    929  * an mbuf **mp0 for use in returning the chain.  The uio is then used
    930  * only for the count in uio_resid.
    931  */
    932 int
    933 soreceive(struct socket *so, struct mbuf **paddr, struct uio *uio,
    934 	struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
    935 {
    936 	struct lwp *l = curlwp;
    937 	struct mbuf	*m, **mp;
    938 	int		flags, len, error, s, offset, moff, type, orig_resid;
    939 	const struct protosw	*pr;
    940 	struct mbuf	*nextrecord;
    941 	int		mbuf_removed = 0;
    942 
    943 	pr = so->so_proto;
    944 	mp = mp0;
    945 	type = 0;
    946 	orig_resid = uio->uio_resid;
    947 
    948 	if (paddr)
    949 		*paddr = 0;
    950 	if (controlp)
    951 		*controlp = 0;
    952 	if (flagsp)
    953 		flags = *flagsp &~ MSG_EOR;
    954 	else
    955 		flags = 0;
    956 
    957 	if ((flags & MSG_DONTWAIT) == 0)
    958 		sodopendfree(so);
    959 
    960 	if (flags & MSG_OOB) {
    961 		m = m_get(M_WAIT, MT_DATA);
    962 		error = (*pr->pr_usrreq)(so, PRU_RCVOOB, m,
    963 		    (struct mbuf *)(long)(flags & MSG_PEEK),
    964 		    (struct mbuf *)0, l);
    965 		if (error)
    966 			goto bad;
    967 		do {
    968 			error = uiomove(mtod(m, caddr_t),
    969 			    (int) min(uio->uio_resid, m->m_len), uio);
    970 			m = m_free(m);
    971 		} while (uio->uio_resid && error == 0 && m);
    972  bad:
    973 		if (m)
    974 			m_freem(m);
    975 		return (error);
    976 	}
    977 	if (mp)
    978 		*mp = (struct mbuf *)0;
    979 	if (so->so_state & SS_ISCONFIRMING && uio->uio_resid)
    980 		(*pr->pr_usrreq)(so, PRU_RCVD, (struct mbuf *)0,
    981 		    (struct mbuf *)0, (struct mbuf *)0, l);
    982 
    983  restart:
    984 	if ((error = sblock(&so->so_rcv, SBLOCKWAIT(flags))) != 0)
    985 		return (error);
    986 	s = splsoftnet();
    987 
    988 	m = so->so_rcv.sb_mb;
    989 	/*
    990 	 * If we have less data than requested, block awaiting more
    991 	 * (subject to any timeout) if:
    992 	 *   1. the current count is less than the low water mark,
    993 	 *   2. MSG_WAITALL is set, and it is possible to do the entire
    994 	 *	receive operation at once if we block (resid <= hiwat), or
    995 	 *   3. MSG_DONTWAIT is not set.
    996 	 * If MSG_WAITALL is set but resid is larger than the receive buffer,
    997 	 * we have to do the receive in sections, and thus risk returning
    998 	 * a short count if a timeout or signal occurs after we start.
    999 	 */
   1000 	if (m == 0 || (((flags & MSG_DONTWAIT) == 0 &&
   1001 	    so->so_rcv.sb_cc < uio->uio_resid) &&
   1002 	    (so->so_rcv.sb_cc < so->so_rcv.sb_lowat ||
   1003 	    ((flags & MSG_WAITALL) && uio->uio_resid <= so->so_rcv.sb_hiwat)) &&
   1004 	    m->m_nextpkt == 0 && (pr->pr_flags & PR_ATOMIC) == 0)) {
   1005 #ifdef DIAGNOSTIC
   1006 		if (m == 0 && so->so_rcv.sb_cc)
   1007 			panic("receive 1");
   1008 #endif
   1009 		if (so->so_error) {
   1010 			if (m)
   1011 				goto dontblock;
   1012 			error = so->so_error;
   1013 			if ((flags & MSG_PEEK) == 0)
   1014 				so->so_error = 0;
   1015 			goto release;
   1016 		}
   1017 		if (so->so_state & SS_CANTRCVMORE) {
   1018 			if (m)
   1019 				goto dontblock;
   1020 			else
   1021 				goto release;
   1022 		}
   1023 		for (; m; m = m->m_next)
   1024 			if (m->m_type == MT_OOBDATA  || (m->m_flags & M_EOR)) {
   1025 				m = so->so_rcv.sb_mb;
   1026 				goto dontblock;
   1027 			}
   1028 		if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
   1029 		    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
   1030 			error = ENOTCONN;
   1031 			goto release;
   1032 		}
   1033 		if (uio->uio_resid == 0)
   1034 			goto release;
   1035 		if ((so->so_state & SS_NBIO) || (flags & MSG_DONTWAIT)) {
   1036 			error = EWOULDBLOCK;
   1037 			goto release;
   1038 		}
   1039 		SBLASTRECORDCHK(&so->so_rcv, "soreceive sbwait 1");
   1040 		SBLASTMBUFCHK(&so->so_rcv, "soreceive sbwait 1");
   1041 		sbunlock(&so->so_rcv);
   1042 		error = sbwait(&so->so_rcv);
   1043 		splx(s);
   1044 		if (error)
   1045 			return (error);
   1046 		goto restart;
   1047 	}
   1048  dontblock:
   1049 	/*
   1050 	 * On entry here, m points to the first record of the socket buffer.
   1051 	 * While we process the initial mbufs containing address and control
   1052 	 * info, we save a copy of m->m_nextpkt into nextrecord.
   1053 	 */
   1054 	if (l)
   1055 		l->l_proc->p_stats->p_ru.ru_msgrcv++;
   1056 	KASSERT(m == so->so_rcv.sb_mb);
   1057 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 1");
   1058 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 1");
   1059 	nextrecord = m->m_nextpkt;
   1060 	if (pr->pr_flags & PR_ADDR) {
   1061 #ifdef DIAGNOSTIC
   1062 		if (m->m_type != MT_SONAME)
   1063 			panic("receive 1a");
   1064 #endif
   1065 		orig_resid = 0;
   1066 		if (flags & MSG_PEEK) {
   1067 			if (paddr)
   1068 				*paddr = m_copy(m, 0, m->m_len);
   1069 			m = m->m_next;
   1070 		} else {
   1071 			sbfree(&so->so_rcv, m);
   1072 			mbuf_removed = 1;
   1073 			if (paddr) {
   1074 				*paddr = m;
   1075 				so->so_rcv.sb_mb = m->m_next;
   1076 				m->m_next = 0;
   1077 				m = so->so_rcv.sb_mb;
   1078 			} else {
   1079 				MFREE(m, so->so_rcv.sb_mb);
   1080 				m = so->so_rcv.sb_mb;
   1081 			}
   1082 		}
   1083 	}
   1084 	while (m && m->m_type == MT_CONTROL && error == 0) {
   1085 		if (flags & MSG_PEEK) {
   1086 			if (controlp)
   1087 				*controlp = m_copy(m, 0, m->m_len);
   1088 			m = m->m_next;
   1089 		} else {
   1090 			sbfree(&so->so_rcv, m);
   1091 			mbuf_removed = 1;
   1092 			if (controlp) {
   1093 				struct domain *dom = pr->pr_domain;
   1094 				if (dom->dom_externalize && l &&
   1095 				    mtod(m, struct cmsghdr *)->cmsg_type ==
   1096 				    SCM_RIGHTS)
   1097 					error = (*dom->dom_externalize)(m, l);
   1098 				*controlp = m;
   1099 				so->so_rcv.sb_mb = m->m_next;
   1100 				m->m_next = 0;
   1101 				m = so->so_rcv.sb_mb;
   1102 			} else {
   1103 				/*
   1104 				 * Dispose of any SCM_RIGHTS message that went
   1105 				 * through the read path rather than recv.
   1106 				 */
   1107 				if (pr->pr_domain->dom_dispose &&
   1108 				    mtod(m, struct cmsghdr *)->cmsg_type == SCM_RIGHTS)
   1109 					(*pr->pr_domain->dom_dispose)(m);
   1110 				MFREE(m, so->so_rcv.sb_mb);
   1111 				m = so->so_rcv.sb_mb;
   1112 			}
   1113 		}
   1114 		if (controlp) {
   1115 			orig_resid = 0;
   1116 			controlp = &(*controlp)->m_next;
   1117 		}
   1118 	}
   1119 
   1120 	/*
   1121 	 * If m is non-NULL, we have some data to read.  From now on,
   1122 	 * make sure to keep sb_lastrecord consistent when working on
   1123 	 * the last packet on the chain (nextrecord == NULL) and we
   1124 	 * change m->m_nextpkt.
   1125 	 */
   1126 	if (m) {
   1127 		if ((flags & MSG_PEEK) == 0) {
   1128 			m->m_nextpkt = nextrecord;
   1129 			/*
   1130 			 * If nextrecord == NULL (this is a single chain),
   1131 			 * then sb_lastrecord may not be valid here if m
   1132 			 * was changed earlier.
   1133 			 */
   1134 			if (nextrecord == NULL) {
   1135 				KASSERT(so->so_rcv.sb_mb == m);
   1136 				so->so_rcv.sb_lastrecord = m;
   1137 			}
   1138 		}
   1139 		type = m->m_type;
   1140 		if (type == MT_OOBDATA)
   1141 			flags |= MSG_OOB;
   1142 	} else {
   1143 		if ((flags & MSG_PEEK) == 0) {
   1144 			KASSERT(so->so_rcv.sb_mb == m);
   1145 			so->so_rcv.sb_mb = nextrecord;
   1146 			SB_EMPTY_FIXUP(&so->so_rcv);
   1147 		}
   1148 	}
   1149 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 2");
   1150 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 2");
   1151 
   1152 	moff = 0;
   1153 	offset = 0;
   1154 	while (m && uio->uio_resid > 0 && error == 0) {
   1155 		if (m->m_type == MT_OOBDATA) {
   1156 			if (type != MT_OOBDATA)
   1157 				break;
   1158 		} else if (type == MT_OOBDATA)
   1159 			break;
   1160 #ifdef DIAGNOSTIC
   1161 		else if (m->m_type != MT_DATA && m->m_type != MT_HEADER)
   1162 			panic("receive 3");
   1163 #endif
   1164 		so->so_state &= ~SS_RCVATMARK;
   1165 		len = uio->uio_resid;
   1166 		if (so->so_oobmark && len > so->so_oobmark - offset)
   1167 			len = so->so_oobmark - offset;
   1168 		if (len > m->m_len - moff)
   1169 			len = m->m_len - moff;
   1170 		/*
   1171 		 * If mp is set, just pass back the mbufs.
   1172 		 * Otherwise copy them out via the uio, then free.
   1173 		 * Sockbuf must be consistent here (points to current mbuf,
   1174 		 * it points to next record) when we drop priority;
   1175 		 * we must note any additions to the sockbuf when we
   1176 		 * block interrupts again.
   1177 		 */
   1178 		if (mp == 0) {
   1179 			SBLASTRECORDCHK(&so->so_rcv, "soreceive uiomove");
   1180 			SBLASTMBUFCHK(&so->so_rcv, "soreceive uiomove");
   1181 			splx(s);
   1182 			error = uiomove(mtod(m, caddr_t) + moff, (int)len, uio);
   1183 			s = splsoftnet();
   1184 			if (error) {
   1185 				/*
   1186 				 * If any part of the record has been removed
   1187 				 * (such as the MT_SONAME mbuf, which will
   1188 				 * happen when PR_ADDR, and thus also
   1189 				 * PR_ATOMIC, is set), then drop the entire
   1190 				 * record to maintain the atomicity of the
   1191 				 * receive operation.
   1192 				 *
   1193 				 * This avoids a later panic("receive 1a")
   1194 				 * when compiled with DIAGNOSTIC.
   1195 				 */
   1196 				if (m && mbuf_removed
   1197 				    && (pr->pr_flags & PR_ATOMIC))
   1198 					(void) sbdroprecord(&so->so_rcv);
   1199 
   1200 				goto release;
   1201 			}
   1202 		} else
   1203 			uio->uio_resid -= len;
   1204 		if (len == m->m_len - moff) {
   1205 			if (m->m_flags & M_EOR)
   1206 				flags |= MSG_EOR;
   1207 			if (flags & MSG_PEEK) {
   1208 				m = m->m_next;
   1209 				moff = 0;
   1210 			} else {
   1211 				nextrecord = m->m_nextpkt;
   1212 				sbfree(&so->so_rcv, m);
   1213 				if (mp) {
   1214 					*mp = m;
   1215 					mp = &m->m_next;
   1216 					so->so_rcv.sb_mb = m = m->m_next;
   1217 					*mp = (struct mbuf *)0;
   1218 				} else {
   1219 					MFREE(m, so->so_rcv.sb_mb);
   1220 					m = so->so_rcv.sb_mb;
   1221 				}
   1222 				/*
   1223 				 * If m != NULL, we also know that
   1224 				 * so->so_rcv.sb_mb != NULL.
   1225 				 */
   1226 				KASSERT(so->so_rcv.sb_mb == m);
   1227 				if (m) {
   1228 					m->m_nextpkt = nextrecord;
   1229 					if (nextrecord == NULL)
   1230 						so->so_rcv.sb_lastrecord = m;
   1231 				} else {
   1232 					so->so_rcv.sb_mb = nextrecord;
   1233 					SB_EMPTY_FIXUP(&so->so_rcv);
   1234 				}
   1235 				SBLASTRECORDCHK(&so->so_rcv, "soreceive 3");
   1236 				SBLASTMBUFCHK(&so->so_rcv, "soreceive 3");
   1237 			}
   1238 		} else {
   1239 			if (flags & MSG_PEEK)
   1240 				moff += len;
   1241 			else {
   1242 				if (mp)
   1243 					*mp = m_copym(m, 0, len, M_WAIT);
   1244 				m->m_data += len;
   1245 				m->m_len -= len;
   1246 				so->so_rcv.sb_cc -= len;
   1247 			}
   1248 		}
   1249 		if (so->so_oobmark) {
   1250 			if ((flags & MSG_PEEK) == 0) {
   1251 				so->so_oobmark -= len;
   1252 				if (so->so_oobmark == 0) {
   1253 					so->so_state |= SS_RCVATMARK;
   1254 					break;
   1255 				}
   1256 			} else {
   1257 				offset += len;
   1258 				if (offset == so->so_oobmark)
   1259 					break;
   1260 			}
   1261 		}
   1262 		if (flags & MSG_EOR)
   1263 			break;
   1264 		/*
   1265 		 * If the MSG_WAITALL flag is set (for non-atomic socket),
   1266 		 * we must not quit until "uio->uio_resid == 0" or an error
   1267 		 * termination.  If a signal/timeout occurs, return
   1268 		 * with a short count but without error.
   1269 		 * Keep sockbuf locked against other readers.
   1270 		 */
   1271 		while (flags & MSG_WAITALL && m == 0 && uio->uio_resid > 0 &&
   1272 		    !sosendallatonce(so) && !nextrecord) {
   1273 			if (so->so_error || so->so_state & SS_CANTRCVMORE)
   1274 				break;
   1275 			/*
   1276 			 * If we are peeking and the socket receive buffer is
   1277 			 * full, stop since we can't get more data to peek at.
   1278 			 */
   1279 			if ((flags & MSG_PEEK) && sbspace(&so->so_rcv) <= 0)
   1280 				break;
   1281 			/*
   1282 			 * If we've drained the socket buffer, tell the
   1283 			 * protocol in case it needs to do something to
   1284 			 * get it filled again.
   1285 			 */
   1286 			if ((pr->pr_flags & PR_WANTRCVD) && so->so_pcb)
   1287 				(*pr->pr_usrreq)(so, PRU_RCVD,
   1288 				    (struct mbuf *)0,
   1289 				    (struct mbuf *)(long)flags,
   1290 				    (struct mbuf *)0, l);
   1291 			SBLASTRECORDCHK(&so->so_rcv, "soreceive sbwait 2");
   1292 			SBLASTMBUFCHK(&so->so_rcv, "soreceive sbwait 2");
   1293 			error = sbwait(&so->so_rcv);
   1294 			if (error) {
   1295 				sbunlock(&so->so_rcv);
   1296 				splx(s);
   1297 				return (0);
   1298 			}
   1299 			if ((m = so->so_rcv.sb_mb) != NULL)
   1300 				nextrecord = m->m_nextpkt;
   1301 		}
   1302 	}
   1303 
   1304 	if (m && pr->pr_flags & PR_ATOMIC) {
   1305 		flags |= MSG_TRUNC;
   1306 		if ((flags & MSG_PEEK) == 0)
   1307 			(void) sbdroprecord(&so->so_rcv);
   1308 	}
   1309 	if ((flags & MSG_PEEK) == 0) {
   1310 		if (m == 0) {
   1311 			/*
   1312 			 * First part is an inline SB_EMPTY_FIXUP().  Second
   1313 			 * part makes sure sb_lastrecord is up-to-date if
   1314 			 * there is still data in the socket buffer.
   1315 			 */
   1316 			so->so_rcv.sb_mb = nextrecord;
   1317 			if (so->so_rcv.sb_mb == NULL) {
   1318 				so->so_rcv.sb_mbtail = NULL;
   1319 				so->so_rcv.sb_lastrecord = NULL;
   1320 			} else if (nextrecord->m_nextpkt == NULL)
   1321 				so->so_rcv.sb_lastrecord = nextrecord;
   1322 		}
   1323 		SBLASTRECORDCHK(&so->so_rcv, "soreceive 4");
   1324 		SBLASTMBUFCHK(&so->so_rcv, "soreceive 4");
   1325 		if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
   1326 			(*pr->pr_usrreq)(so, PRU_RCVD, (struct mbuf *)0,
   1327 			    (struct mbuf *)(long)flags, (struct mbuf *)0, l);
   1328 	}
   1329 	if (orig_resid == uio->uio_resid && orig_resid &&
   1330 	    (flags & MSG_EOR) == 0 && (so->so_state & SS_CANTRCVMORE) == 0) {
   1331 		sbunlock(&so->so_rcv);
   1332 		splx(s);
   1333 		goto restart;
   1334 	}
   1335 
   1336 	if (flagsp)
   1337 		*flagsp |= flags;
   1338  release:
   1339 	sbunlock(&so->so_rcv);
   1340 	splx(s);
   1341 	return (error);
   1342 }
   1343 
   1344 int
   1345 soshutdown(struct socket *so, int how)
   1346 {
   1347 	const struct protosw	*pr;
   1348 
   1349 	pr = so->so_proto;
   1350 	if (!(how == SHUT_RD || how == SHUT_WR || how == SHUT_RDWR))
   1351 		return (EINVAL);
   1352 
   1353 	if (how == SHUT_RD || how == SHUT_RDWR)
   1354 		sorflush(so);
   1355 	if (how == SHUT_WR || how == SHUT_RDWR)
   1356 		return (*pr->pr_usrreq)(so, PRU_SHUTDOWN, (struct mbuf *)0,
   1357 		    (struct mbuf *)0, (struct mbuf *)0, (struct lwp *)0);
   1358 	return (0);
   1359 }
   1360 
   1361 void
   1362 sorflush(struct socket *so)
   1363 {
   1364 	struct sockbuf	*sb, asb;
   1365 	const struct protosw	*pr;
   1366 	int		s;
   1367 
   1368 	sb = &so->so_rcv;
   1369 	pr = so->so_proto;
   1370 	sb->sb_flags |= SB_NOINTR;
   1371 	(void) sblock(sb, M_WAITOK);
   1372 	s = splnet();
   1373 	socantrcvmore(so);
   1374 	sbunlock(sb);
   1375 	asb = *sb;
   1376 	/*
   1377 	 * Clear most of the sockbuf structure, but leave some of the
   1378 	 * fields valid.
   1379 	 */
   1380 	memset(&sb->sb_startzero, 0,
   1381 	    sizeof(*sb) - offsetof(struct sockbuf, sb_startzero));
   1382 	splx(s);
   1383 	if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose)
   1384 		(*pr->pr_domain->dom_dispose)(asb.sb_mb);
   1385 	sbrelease(&asb, so);
   1386 }
   1387 
   1388 int
   1389 sosetopt(struct socket *so, int level, int optname, struct mbuf *m0)
   1390 {
   1391 	int		error;
   1392 	struct mbuf	*m;
   1393 
   1394 	error = 0;
   1395 	m = m0;
   1396 	if (level != SOL_SOCKET) {
   1397 		if (so->so_proto && so->so_proto->pr_ctloutput)
   1398 			return ((*so->so_proto->pr_ctloutput)
   1399 				  (PRCO_SETOPT, so, level, optname, &m0));
   1400 		error = ENOPROTOOPT;
   1401 	} else {
   1402 		switch (optname) {
   1403 
   1404 		case SO_LINGER:
   1405 			if (m == NULL || m->m_len != sizeof(struct linger)) {
   1406 				error = EINVAL;
   1407 				goto bad;
   1408 			}
   1409 			if (mtod(m, struct linger *)->l_linger < 0 ||
   1410 			    mtod(m, struct linger *)->l_linger > (INT_MAX / hz)) {
   1411 				error = EDOM;
   1412 				goto bad;
   1413 			}
   1414 			so->so_linger = mtod(m, struct linger *)->l_linger;
   1415 			/* fall thru... */
   1416 
   1417 		case SO_DEBUG:
   1418 		case SO_KEEPALIVE:
   1419 		case SO_DONTROUTE:
   1420 		case SO_USELOOPBACK:
   1421 		case SO_BROADCAST:
   1422 		case SO_REUSEADDR:
   1423 		case SO_REUSEPORT:
   1424 		case SO_OOBINLINE:
   1425 		case SO_TIMESTAMP:
   1426 			if (m == NULL || m->m_len < sizeof(int)) {
   1427 				error = EINVAL;
   1428 				goto bad;
   1429 			}
   1430 			if (*mtod(m, int *))
   1431 				so->so_options |= optname;
   1432 			else
   1433 				so->so_options &= ~optname;
   1434 			break;
   1435 
   1436 		case SO_SNDBUF:
   1437 		case SO_RCVBUF:
   1438 		case SO_SNDLOWAT:
   1439 		case SO_RCVLOWAT:
   1440 		    {
   1441 			int optval;
   1442 
   1443 			if (m == NULL || m->m_len < sizeof(int)) {
   1444 				error = EINVAL;
   1445 				goto bad;
   1446 			}
   1447 
   1448 			/*
   1449 			 * Values < 1 make no sense for any of these
   1450 			 * options, so disallow them.
   1451 			 */
   1452 			optval = *mtod(m, int *);
   1453 			if (optval < 1) {
   1454 				error = EINVAL;
   1455 				goto bad;
   1456 			}
   1457 
   1458 			switch (optname) {
   1459 
   1460 			case SO_SNDBUF:
   1461 			case SO_RCVBUF:
   1462 				if (sbreserve(optname == SO_SNDBUF ?
   1463 				    &so->so_snd : &so->so_rcv,
   1464 				    (u_long) optval, so) == 0) {
   1465 					error = ENOBUFS;
   1466 					goto bad;
   1467 				}
   1468 				break;
   1469 
   1470 			/*
   1471 			 * Make sure the low-water is never greater than
   1472 			 * the high-water.
   1473 			 */
   1474 			case SO_SNDLOWAT:
   1475 				so->so_snd.sb_lowat =
   1476 				    (optval > so->so_snd.sb_hiwat) ?
   1477 				    so->so_snd.sb_hiwat : optval;
   1478 				break;
   1479 			case SO_RCVLOWAT:
   1480 				so->so_rcv.sb_lowat =
   1481 				    (optval > so->so_rcv.sb_hiwat) ?
   1482 				    so->so_rcv.sb_hiwat : optval;
   1483 				break;
   1484 			}
   1485 			break;
   1486 		    }
   1487 
   1488 		case SO_SNDTIMEO:
   1489 		case SO_RCVTIMEO:
   1490 		    {
   1491 			struct timeval *tv;
   1492 			int val;
   1493 
   1494 			if (m == NULL || m->m_len < sizeof(*tv)) {
   1495 				error = EINVAL;
   1496 				goto bad;
   1497 			}
   1498 			tv = mtod(m, struct timeval *);
   1499 			if (tv->tv_sec > (INT_MAX - tv->tv_usec / tick) / hz) {
   1500 				error = EDOM;
   1501 				goto bad;
   1502 			}
   1503 			val = tv->tv_sec * hz + tv->tv_usec / tick;
   1504 			if (val == 0 && tv->tv_usec != 0)
   1505 				val = 1;
   1506 
   1507 			switch (optname) {
   1508 
   1509 			case SO_SNDTIMEO:
   1510 				so->so_snd.sb_timeo = val;
   1511 				break;
   1512 			case SO_RCVTIMEO:
   1513 				so->so_rcv.sb_timeo = val;
   1514 				break;
   1515 			}
   1516 			break;
   1517 		    }
   1518 
   1519 		default:
   1520 			error = ENOPROTOOPT;
   1521 			break;
   1522 		}
   1523 		if (error == 0 && so->so_proto && so->so_proto->pr_ctloutput) {
   1524 			(void) ((*so->so_proto->pr_ctloutput)
   1525 				  (PRCO_SETOPT, so, level, optname, &m0));
   1526 			m = NULL;	/* freed by protocol */
   1527 		}
   1528 	}
   1529  bad:
   1530 	if (m)
   1531 		(void) m_free(m);
   1532 	return (error);
   1533 }
   1534 
   1535 int
   1536 sogetopt(struct socket *so, int level, int optname, struct mbuf **mp)
   1537 {
   1538 	struct mbuf	*m;
   1539 
   1540 	if (level != SOL_SOCKET) {
   1541 		if (so->so_proto && so->so_proto->pr_ctloutput) {
   1542 			return ((*so->so_proto->pr_ctloutput)
   1543 				  (PRCO_GETOPT, so, level, optname, mp));
   1544 		} else
   1545 			return (ENOPROTOOPT);
   1546 	} else {
   1547 		m = m_get(M_WAIT, MT_SOOPTS);
   1548 		m->m_len = sizeof(int);
   1549 
   1550 		switch (optname) {
   1551 
   1552 		case SO_LINGER:
   1553 			m->m_len = sizeof(struct linger);
   1554 			mtod(m, struct linger *)->l_onoff =
   1555 				so->so_options & SO_LINGER;
   1556 			mtod(m, struct linger *)->l_linger = so->so_linger;
   1557 			break;
   1558 
   1559 		case SO_USELOOPBACK:
   1560 		case SO_DONTROUTE:
   1561 		case SO_DEBUG:
   1562 		case SO_KEEPALIVE:
   1563 		case SO_REUSEADDR:
   1564 		case SO_REUSEPORT:
   1565 		case SO_BROADCAST:
   1566 		case SO_OOBINLINE:
   1567 		case SO_TIMESTAMP:
   1568 			*mtod(m, int *) = so->so_options & optname;
   1569 			break;
   1570 
   1571 		case SO_TYPE:
   1572 			*mtod(m, int *) = so->so_type;
   1573 			break;
   1574 
   1575 		case SO_ERROR:
   1576 			*mtod(m, int *) = so->so_error;
   1577 			so->so_error = 0;
   1578 			break;
   1579 
   1580 		case SO_SNDBUF:
   1581 			*mtod(m, int *) = so->so_snd.sb_hiwat;
   1582 			break;
   1583 
   1584 		case SO_RCVBUF:
   1585 			*mtod(m, int *) = so->so_rcv.sb_hiwat;
   1586 			break;
   1587 
   1588 		case SO_SNDLOWAT:
   1589 			*mtod(m, int *) = so->so_snd.sb_lowat;
   1590 			break;
   1591 
   1592 		case SO_RCVLOWAT:
   1593 			*mtod(m, int *) = so->so_rcv.sb_lowat;
   1594 			break;
   1595 
   1596 		case SO_SNDTIMEO:
   1597 		case SO_RCVTIMEO:
   1598 		    {
   1599 			int val = (optname == SO_SNDTIMEO ?
   1600 			     so->so_snd.sb_timeo : so->so_rcv.sb_timeo);
   1601 
   1602 			m->m_len = sizeof(struct timeval);
   1603 			mtod(m, struct timeval *)->tv_sec = val / hz;
   1604 			mtod(m, struct timeval *)->tv_usec =
   1605 			    (val % hz) * tick;
   1606 			break;
   1607 		    }
   1608 
   1609 		case SO_OVERFLOWED:
   1610 			*mtod(m, int *) = so->so_rcv.sb_overflowed;
   1611 			break;
   1612 
   1613 		default:
   1614 			(void)m_free(m);
   1615 			return (ENOPROTOOPT);
   1616 		}
   1617 		*mp = m;
   1618 		return (0);
   1619 	}
   1620 }
   1621 
   1622 void
   1623 sohasoutofband(struct socket *so)
   1624 {
   1625 	fownsignal(so->so_pgid, SIGURG, POLL_PRI, POLLPRI|POLLRDBAND, so);
   1626 	selwakeup(&so->so_rcv.sb_sel);
   1627 }
   1628 
   1629 static void
   1630 filt_sordetach(struct knote *kn)
   1631 {
   1632 	struct socket	*so;
   1633 
   1634 	so = (struct socket *)kn->kn_fp->f_data;
   1635 	SLIST_REMOVE(&so->so_rcv.sb_sel.sel_klist, kn, knote, kn_selnext);
   1636 	if (SLIST_EMPTY(&so->so_rcv.sb_sel.sel_klist))
   1637 		so->so_rcv.sb_flags &= ~SB_KNOTE;
   1638 }
   1639 
   1640 /*ARGSUSED*/
   1641 static int
   1642 filt_soread(struct knote *kn, long hint)
   1643 {
   1644 	struct socket	*so;
   1645 
   1646 	so = (struct socket *)kn->kn_fp->f_data;
   1647 	kn->kn_data = so->so_rcv.sb_cc;
   1648 	if (so->so_state & SS_CANTRCVMORE) {
   1649 		kn->kn_flags |= EV_EOF;
   1650 		kn->kn_fflags = so->so_error;
   1651 		return (1);
   1652 	}
   1653 	if (so->so_error)	/* temporary udp error */
   1654 		return (1);
   1655 	if (kn->kn_sfflags & NOTE_LOWAT)
   1656 		return (kn->kn_data >= kn->kn_sdata);
   1657 	return (kn->kn_data >= so->so_rcv.sb_lowat);
   1658 }
   1659 
   1660 static void
   1661 filt_sowdetach(struct knote *kn)
   1662 {
   1663 	struct socket	*so;
   1664 
   1665 	so = (struct socket *)kn->kn_fp->f_data;
   1666 	SLIST_REMOVE(&so->so_snd.sb_sel.sel_klist, kn, knote, kn_selnext);
   1667 	if (SLIST_EMPTY(&so->so_snd.sb_sel.sel_klist))
   1668 		so->so_snd.sb_flags &= ~SB_KNOTE;
   1669 }
   1670 
   1671 /*ARGSUSED*/
   1672 static int
   1673 filt_sowrite(struct knote *kn, long hint)
   1674 {
   1675 	struct socket	*so;
   1676 
   1677 	so = (struct socket *)kn->kn_fp->f_data;
   1678 	kn->kn_data = sbspace(&so->so_snd);
   1679 	if (so->so_state & SS_CANTSENDMORE) {
   1680 		kn->kn_flags |= EV_EOF;
   1681 		kn->kn_fflags = so->so_error;
   1682 		return (1);
   1683 	}
   1684 	if (so->so_error)	/* temporary udp error */
   1685 		return (1);
   1686 	if (((so->so_state & SS_ISCONNECTED) == 0) &&
   1687 	    (so->so_proto->pr_flags & PR_CONNREQUIRED))
   1688 		return (0);
   1689 	if (kn->kn_sfflags & NOTE_LOWAT)
   1690 		return (kn->kn_data >= kn->kn_sdata);
   1691 	return (kn->kn_data >= so->so_snd.sb_lowat);
   1692 }
   1693 
   1694 /*ARGSUSED*/
   1695 static int
   1696 filt_solisten(struct knote *kn, long hint)
   1697 {
   1698 	struct socket	*so;
   1699 
   1700 	so = (struct socket *)kn->kn_fp->f_data;
   1701 
   1702 	/*
   1703 	 * Set kn_data to number of incoming connections, not
   1704 	 * counting partial (incomplete) connections.
   1705 	 */
   1706 	kn->kn_data = so->so_qlen;
   1707 	return (kn->kn_data > 0);
   1708 }
   1709 
   1710 static const struct filterops solisten_filtops =
   1711 	{ 1, NULL, filt_sordetach, filt_solisten };
   1712 static const struct filterops soread_filtops =
   1713 	{ 1, NULL, filt_sordetach, filt_soread };
   1714 static const struct filterops sowrite_filtops =
   1715 	{ 1, NULL, filt_sowdetach, filt_sowrite };
   1716 
   1717 int
   1718 soo_kqfilter(struct file *fp, struct knote *kn)
   1719 {
   1720 	struct socket	*so;
   1721 	struct sockbuf	*sb;
   1722 
   1723 	so = (struct socket *)kn->kn_fp->f_data;
   1724 	switch (kn->kn_filter) {
   1725 	case EVFILT_READ:
   1726 		if (so->so_options & SO_ACCEPTCONN)
   1727 			kn->kn_fop = &solisten_filtops;
   1728 		else
   1729 			kn->kn_fop = &soread_filtops;
   1730 		sb = &so->so_rcv;
   1731 		break;
   1732 	case EVFILT_WRITE:
   1733 		kn->kn_fop = &sowrite_filtops;
   1734 		sb = &so->so_snd;
   1735 		break;
   1736 	default:
   1737 		return (1);
   1738 	}
   1739 	SLIST_INSERT_HEAD(&sb->sb_sel.sel_klist, kn, kn_selnext);
   1740 	sb->sb_flags |= SB_KNOTE;
   1741 	return (0);
   1742 }
   1743 
   1744 #include <sys/sysctl.h>
   1745 
   1746 static int sysctl_kern_somaxkva(SYSCTLFN_PROTO);
   1747 
   1748 /*
   1749  * sysctl helper routine for kern.somaxkva.  ensures that the given
   1750  * value is not too small.
   1751  * (XXX should we maybe make sure it's not too large as well?)
   1752  */
   1753 static int
   1754 sysctl_kern_somaxkva(SYSCTLFN_ARGS)
   1755 {
   1756 	int error, new_somaxkva;
   1757 	struct sysctlnode node;
   1758 	int s;
   1759 
   1760 	new_somaxkva = somaxkva;
   1761 	node = *rnode;
   1762 	node.sysctl_data = &new_somaxkva;
   1763 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
   1764 	if (error || newp == NULL)
   1765 		return (error);
   1766 
   1767 	if (new_somaxkva < (16 * 1024 * 1024)) /* sanity */
   1768 		return (EINVAL);
   1769 
   1770 	s = splvm();
   1771 	simple_lock(&so_pendfree_slock);
   1772 	somaxkva = new_somaxkva;
   1773 	wakeup(&socurkva);
   1774 	simple_unlock(&so_pendfree_slock);
   1775 	splx(s);
   1776 
   1777 	return (error);
   1778 }
   1779 
   1780 SYSCTL_SETUP(sysctl_kern_somaxkva_setup, "sysctl kern.somaxkva setup")
   1781 {
   1782 
   1783 	sysctl_createv(clog, 0, NULL, NULL,
   1784 		       CTLFLAG_PERMANENT,
   1785 		       CTLTYPE_NODE, "kern", NULL,
   1786 		       NULL, 0, NULL, 0,
   1787 		       CTL_KERN, CTL_EOL);
   1788 
   1789 	sysctl_createv(clog, 0, NULL, NULL,
   1790 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   1791 		       CTLTYPE_INT, "somaxkva",
   1792 		       SYSCTL_DESCR("Maximum amount of kernel memory to be "
   1793 				    "used for socket buffers"),
   1794 		       sysctl_kern_somaxkva, 0, NULL, 0,
   1795 		       CTL_KERN, KERN_SOMAXKVA, CTL_EOL);
   1796 }
   1797