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File: [cvs.NetBSD.org] / src / sys / kern / uipc_socket.c (download)

Revision 1.66.4.2, Fri Nov 8 09:31:35 2002 UTC (12 years, 1 month ago) by tron
Branch: netbsd-1-6
CVS Tags: netbsd-1-6-PATCH002-RELEASE, netbsd-1-6-PATCH002-RC4, netbsd-1-6-PATCH002-RC3, netbsd-1-6-PATCH002-RC2, netbsd-1-6-PATCH002-RC1, netbsd-1-6-PATCH002, netbsd-1-6-PATCH001-RELEASE, netbsd-1-6-PATCH001-RC3, netbsd-1-6-PATCH001-RC2, netbsd-1-6-PATCH001-RC1, netbsd-1-6-PATCH001
Changes since 1.66.4.1: +17 -0 lines

Pull up revision 1.68 (requested by thorpej in ticket #429):
Fix 2 bugs with MSG_WAITALL.  The first is to not block forever if one is
trying to MSG_PEEK for more than the socket can hold.  The second is that
before sleeping waiting for more data, upcall the protocol telling it you
have just received data so it can kick itself to re-fill the just drained
socket buffer.

/*	$NetBSD: uipc_socket.c,v 1.66.4.2 2002/11/08 09:31:35 tron Exp $	*/

/*-
 * Copyright (c) 2002 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe of Wasabi Systems, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the NetBSD
 *	Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Copyright (c) 1982, 1986, 1988, 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)uipc_socket.c	8.6 (Berkeley) 5/2/95
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: uipc_socket.c,v 1.66.4.2 2002/11/08 09:31:35 tron Exp $");

#include "opt_sock_counters.h"
#include "opt_sosend_loan.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/kernel.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/signalvar.h>
#include <sys/resourcevar.h>
#include <sys/pool.h>

#include <uvm/uvm.h>

struct pool	socket_pool;

extern int	somaxconn;			/* patchable (XXX sysctl) */
int		somaxconn = SOMAXCONN;

#ifdef SOSEND_COUNTERS
#include <sys/device.h>

struct evcnt sosend_loan_big = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
    NULL, "sosend", "loan big");
struct evcnt sosend_copy_big = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
    NULL, "sosend", "copy big");
struct evcnt sosend_copy_small = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
    NULL, "sosend", "copy small");
struct evcnt sosend_kvalimit = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
    NULL, "sosend", "kva limit");

#define	SOSEND_COUNTER_INCR(ev)		(ev)->ev_count++

#else

#define	SOSEND_COUNTER_INCR(ev)		/* nothing */

#endif /* SOSEND_COUNTERS */

void
soinit(void)
{

	pool_init(&socket_pool, sizeof(struct socket), 0, 0, 0,
	    "sockpl", NULL);

#ifdef SOSEND_COUNTERS
	evcnt_attach_static(&sosend_loan_big);
	evcnt_attach_static(&sosend_copy_big);
	evcnt_attach_static(&sosend_copy_small);
	evcnt_attach_static(&sosend_kvalimit);
#endif /* SOSEND_COUNTERS */
}

#ifdef SOSEND_LOAN
int use_sosend_loan = 1;
#else
int use_sosend_loan = 0;
#endif

struct mbuf *so_pendfree;

int somaxkva = 16 * 1024 * 1024;
int socurkva;
int sokvawaiters;

#define	SOCK_LOAN_THRESH	4096
#define	SOCK_LOAN_CHUNK		65536

static void
sodoloanfree(caddr_t buf, u_int size)
{
	struct vm_page **pgs;
	vaddr_t va, sva, eva;
	vsize_t len;
	paddr_t pa;
	int i, npgs;

	eva = round_page((vaddr_t) buf + size);
	sva = trunc_page((vaddr_t) buf);
	len = eva - sva;
	npgs = len >> PAGE_SHIFT;

	pgs = alloca(npgs * sizeof(*pgs));

	for (i = 0, va = sva; va < eva; i++, va += PAGE_SIZE) {
		if (pmap_extract(pmap_kernel(), va, &pa) == FALSE)
			panic("sodoloanfree: va 0x%lx not mapped", va);
		pgs[i] = PHYS_TO_VM_PAGE(pa);
	}

	pmap_kremove(sva, len);
	pmap_update(pmap_kernel());
	uvm_unloan(pgs, npgs, UVM_LOAN_TOPAGE);
	uvm_km_free(kernel_map, sva, len);
	socurkva -= len;
	if (sokvawaiters)
		wakeup(&socurkva);
}

static size_t
sodopendfree(struct socket *so)
{
	struct mbuf *m;
	size_t rv = 0;
	int s;

	s = splvm();

	for (;;) {
		m = so_pendfree;
		if (m == NULL)
			break;
		so_pendfree = m->m_next;
		splx(s);

		rv += m->m_ext.ext_size;
		sodoloanfree(m->m_ext.ext_buf, m->m_ext.ext_size);
		s = splvm();
		pool_cache_put(&mbpool_cache, m);
	}

	for (;;) {
		m = so->so_pendfree;
		if (m == NULL)
			break;
		so->so_pendfree = m->m_next;
		splx(s);

		rv += m->m_ext.ext_size;
		sodoloanfree(m->m_ext.ext_buf, m->m_ext.ext_size);
		s = splvm();
		pool_cache_put(&mbpool_cache, m);
	}

	splx(s);
	return (rv);
}

static void
soloanfree(struct mbuf *m, caddr_t buf, u_int size, void *arg)
{
	struct socket *so = arg;
	int s;

	if (m == NULL) {
		sodoloanfree(buf, size);
		return;
	}

	s = splvm();
	m->m_next = so->so_pendfree;
	so->so_pendfree = m;
	splx(s);
	if (sokvawaiters)
		wakeup(&socurkva);
}

static long
sosend_loan(struct socket *so, struct uio *uio, struct mbuf *m, long space)
{
	struct iovec *iov = uio->uio_iov;
	vaddr_t sva, eva;
	vsize_t len;
	struct vm_page **pgs;
	vaddr_t lva, va;
	int npgs, s, i, error;

	if (uio->uio_segflg != UIO_USERSPACE)
		return (0);

	if (iov->iov_len < (size_t) space)
		space = iov->iov_len;
	if (space > SOCK_LOAN_CHUNK)
		space = SOCK_LOAN_CHUNK;

	eva = round_page((vaddr_t) iov->iov_base + space);
	sva = trunc_page((vaddr_t) iov->iov_base);
	len = eva - sva;
	npgs = len >> PAGE_SHIFT;

	while (socurkva + len > somaxkva) {
		if (sodopendfree(so))
			continue;
		SOSEND_COUNTER_INCR(&sosend_kvalimit);
		s = splvm();
		sokvawaiters++;
		(void) tsleep(&socurkva, PVM, "sokva", 0);
		sokvawaiters--;
		splx(s);
	}

	lva = uvm_km_valloc_wait(kernel_map, len);
	if (lva == 0)
		return (0);
	socurkva += len;

	pgs = alloca(npgs * sizeof(*pgs));

	error = uvm_loan(&uio->uio_procp->p_vmspace->vm_map, sva, len,
	    pgs, UVM_LOAN_TOPAGE);
	if (error) {
		uvm_km_free(kernel_map, lva, len);
		socurkva -= len;
		return (0);
	}

	for (i = 0, va = lva; i < npgs; i++, va += PAGE_SIZE)
		pmap_kenter_pa(va, VM_PAGE_TO_PHYS(pgs[i]), VM_PROT_READ);
	pmap_update(pmap_kernel());

	lva += (vaddr_t) iov->iov_base & PAGE_MASK;

	MEXTADD(m, (caddr_t) lva, space, M_MBUF, soloanfree, so);

	uio->uio_resid -= space;
	/* uio_offset not updated, not set/used for write(2) */
	uio->uio_iov->iov_base = (caddr_t) uio->uio_iov->iov_base + space;
	uio->uio_iov->iov_len -= space;
	if (uio->uio_iov->iov_len == 0) {
		uio->uio_iov++;
		uio->uio_iovcnt--;
	}

	return (space);
}

/*
 * Socket operation routines.
 * These routines are called by the routines in
 * sys_socket.c or from a system process, and
 * implement the semantics of socket operations by
 * switching out to the protocol specific routines.
 */
/*ARGSUSED*/
int
socreate(int dom, struct socket **aso, int type, int proto)
{
	struct proc	*p;
	struct protosw	*prp;
	struct socket	*so;
	int		error, s;

	p = curproc;		/* XXX */
	if (proto)
		prp = pffindproto(dom, proto, type);
	else
		prp = pffindtype(dom, type);
	if (prp == 0 || prp->pr_usrreq == 0)
		return (EPROTONOSUPPORT);
	if (prp->pr_type != type)
		return (EPROTOTYPE);
	s = splsoftnet();
	so = pool_get(&socket_pool, PR_WAITOK);
	memset((caddr_t)so, 0, sizeof(*so));
	TAILQ_INIT(&so->so_q0);
	TAILQ_INIT(&so->so_q);
	so->so_type = type;
	so->so_proto = prp;
	so->so_send = sosend;
	so->so_receive = soreceive;
	if (p != 0)
		so->so_uid = p->p_ucred->cr_uid;
	error = (*prp->pr_usrreq)(so, PRU_ATTACH, (struct mbuf *)0,
	    (struct mbuf *)(long)proto, (struct mbuf *)0, p);
	if (error) {
		so->so_state |= SS_NOFDREF;
		sofree(so);
		splx(s);
		return (error);
	}
	splx(s);
	*aso = so;
	return (0);
}

int
sobind(struct socket *so, struct mbuf *nam, struct proc *p)
{
	int	s, error;

	s = splsoftnet();
	error = (*so->so_proto->pr_usrreq)(so, PRU_BIND, (struct mbuf *)0,
	    nam, (struct mbuf *)0, p);
	splx(s);
	return (error);
}

int
solisten(struct socket *so, int backlog)
{
	int	s, error;

	s = splsoftnet();
	error = (*so->so_proto->pr_usrreq)(so, PRU_LISTEN, (struct mbuf *)0,
	    (struct mbuf *)0, (struct mbuf *)0, (struct proc *)0);
	if (error) {
		splx(s);
		return (error);
	}
	if (TAILQ_EMPTY(&so->so_q))
		so->so_options |= SO_ACCEPTCONN;
	if (backlog < 0)
		backlog = 0;
	so->so_qlimit = min(backlog, somaxconn);
	splx(s);
	return (0);
}

void
sofree(struct socket *so)
{
	struct mbuf *m;

	if (so->so_pcb || (so->so_state & SS_NOFDREF) == 0)
		return;
	if (so->so_head) {
		/*
		 * We must not decommission a socket that's on the accept(2)
		 * queue.  If we do, then accept(2) may hang after select(2)
		 * indicated that the listening socket was ready.
		 */
		if (!soqremque(so, 0))
			return;
	}
	sbrelease(&so->so_snd);
	sorflush(so);
	while ((m = so->so_pendfree) != NULL) {
		so->so_pendfree = m->m_next;
		m->m_next = so_pendfree;
		so_pendfree = m;
	}
	pool_put(&socket_pool, so);
}

/*
 * Close a socket on last file table reference removal.
 * Initiate disconnect if connected.
 * Free socket when disconnect complete.
 */
int
soclose(struct socket *so)
{
	struct socket	*so2;
	int		s, error;

	error = 0;
	s = splsoftnet();		/* conservative */
	if (so->so_options & SO_ACCEPTCONN) {
		while ((so2 = TAILQ_FIRST(&so->so_q0)) != 0) {
			(void) soqremque(so2, 0);
			(void) soabort(so2);
		}
		while ((so2 = TAILQ_FIRST(&so->so_q)) != 0) {
			(void) soqremque(so2, 1);
			(void) soabort(so2);
		}
	}
	if (so->so_pcb == 0)
		goto discard;
	if (so->so_state & SS_ISCONNECTED) {
		if ((so->so_state & SS_ISDISCONNECTING) == 0) {
			error = sodisconnect(so);
			if (error)
				goto drop;
		}
		if (so->so_options & SO_LINGER) {
			if ((so->so_state & SS_ISDISCONNECTING) &&
			    (so->so_state & SS_NBIO))
				goto drop;
			while (so->so_state & SS_ISCONNECTED) {
				error = tsleep((caddr_t)&so->so_timeo,
					       PSOCK | PCATCH, netcls,
					       so->so_linger * hz);
				if (error)
					break;
			}
		}
	}
 drop:
	if (so->so_pcb) {
		int error2 = (*so->so_proto->pr_usrreq)(so, PRU_DETACH,
		    (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0,
		    (struct proc *)0);
		if (error == 0)
			error = error2;
	}
 discard:
	if (so->so_state & SS_NOFDREF)
		panic("soclose: NOFDREF");
	so->so_state |= SS_NOFDREF;
	sofree(so);
	splx(s);
	return (error);
}

/*
 * Must be called at splsoftnet...
 */
int
soabort(struct socket *so)
{

	return (*so->so_proto->pr_usrreq)(so, PRU_ABORT, (struct mbuf *)0,
	    (struct mbuf *)0, (struct mbuf *)0, (struct proc *)0);
}

int
soaccept(struct socket *so, struct mbuf *nam)
{
	int	s, error;

	error = 0;
	s = splsoftnet();
	if ((so->so_state & SS_NOFDREF) == 0)
		panic("soaccept: !NOFDREF");
	so->so_state &= ~SS_NOFDREF;
	if ((so->so_state & SS_ISDISCONNECTED) == 0 ||
	    (so->so_proto->pr_flags & PR_ABRTACPTDIS) == 0)
		error = (*so->so_proto->pr_usrreq)(so, PRU_ACCEPT,
		    (struct mbuf *)0, nam, (struct mbuf *)0, (struct proc *)0);
	else
		error = ECONNABORTED;

	splx(s);
	return (error);
}

int
soconnect(struct socket *so, struct mbuf *nam)
{
	struct proc	*p;
	int		s, error;

	p = curproc;		/* XXX */
	if (so->so_options & SO_ACCEPTCONN)
		return (EOPNOTSUPP);
	s = splsoftnet();
	/*
	 * If protocol is connection-based, can only connect once.
	 * Otherwise, if connected, try to disconnect first.
	 * This allows user to disconnect by connecting to, e.g.,
	 * a null address.
	 */
	if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
	    ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
	    (error = sodisconnect(so))))
		error = EISCONN;
	else
		error = (*so->so_proto->pr_usrreq)(so, PRU_CONNECT,
		    (struct mbuf *)0, nam, (struct mbuf *)0, p);
	splx(s);
	return (error);
}

int
soconnect2(struct socket *so1, struct socket *so2)
{
	int	s, error;

	s = splsoftnet();
	error = (*so1->so_proto->pr_usrreq)(so1, PRU_CONNECT2,
	    (struct mbuf *)0, (struct mbuf *)so2, (struct mbuf *)0,
	    (struct proc *)0);
	splx(s);
	return (error);
}

int
sodisconnect(struct socket *so)
{
	int	s, error;

	s = splsoftnet();
	if ((so->so_state & SS_ISCONNECTED) == 0) {
		error = ENOTCONN;
		goto bad;
	}
	if (so->so_state & SS_ISDISCONNECTING) {
		error = EALREADY;
		goto bad;
	}
	error = (*so->so_proto->pr_usrreq)(so, PRU_DISCONNECT,
	    (struct mbuf *)0, (struct mbuf *)0, (struct mbuf *)0,
	    (struct proc *)0);
 bad:
	splx(s);
	sodopendfree(so);
	return (error);
}

#define	SBLOCKWAIT(f)	(((f) & MSG_DONTWAIT) ? M_NOWAIT : M_WAITOK)
/*
 * Send on a socket.
 * If send must go all at once and message is larger than
 * send buffering, then hard error.
 * Lock against other senders.
 * If must go all at once and not enough room now, then
 * inform user that this would block and do nothing.
 * Otherwise, if nonblocking, send as much as possible.
 * The data to be sent is described by "uio" if nonzero,
 * otherwise by the mbuf chain "top" (which must be null
 * if uio is not).  Data provided in mbuf chain must be small
 * enough to send all at once.
 *
 * Returns nonzero on error, timeout or signal; callers
 * must check for short counts if EINTR/ERESTART are returned.
 * Data and control buffers are freed on return.
 */
int
sosend(struct socket *so, struct mbuf *addr, struct uio *uio, struct mbuf *top,
	struct mbuf *control, int flags)
{
	struct proc	*p;
	struct mbuf	**mp, *m;
	long		space, len, resid, clen, mlen;
	int		error, s, dontroute, atomic;

	sodopendfree(so);

	p = curproc;		/* XXX */
	clen = 0;
	atomic = sosendallatonce(so) || top;
	if (uio)
		resid = uio->uio_resid;
	else
		resid = top->m_pkthdr.len;
	/*
	 * In theory resid should be unsigned.
	 * However, space must be signed, as it might be less than 0
	 * if we over-committed, and we must use a signed comparison
	 * of space and resid.  On the other hand, a negative resid
	 * causes us to loop sending 0-length segments to the protocol.
	 */
	if (resid < 0) {
		error = EINVAL;
		goto out;
	}
	dontroute =
	    (flags & MSG_DONTROUTE) && (so->so_options & SO_DONTROUTE) == 0 &&
	    (so->so_proto->pr_flags & PR_ATOMIC);
	p->p_stats->p_ru.ru_msgsnd++;
	if (control)
		clen = control->m_len;
#define	snderr(errno)	{ error = errno; splx(s); goto release; }

 restart:
	if ((error = sblock(&so->so_snd, SBLOCKWAIT(flags))) != 0)
		goto out;
	do {
		s = splsoftnet();
		if (so->so_state & SS_CANTSENDMORE)
			snderr(EPIPE);
		if (so->so_error) {
			error = so->so_error;
			so->so_error = 0;
			splx(s);
			goto release;
		}
		if ((so->so_state & SS_ISCONNECTED) == 0) {
			if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
				if ((so->so_state & SS_ISCONFIRMING) == 0 &&
				    !(resid == 0 && clen != 0))
					snderr(ENOTCONN);
			} else if (addr == 0)
				snderr(EDESTADDRREQ);
		}
		space = sbspace(&so->so_snd);
		if (flags & MSG_OOB)
			space += 1024;
		if ((atomic && resid > so->so_snd.sb_hiwat) ||
		    clen > so->so_snd.sb_hiwat)
			snderr(EMSGSIZE);
		if (space < resid + clen && uio &&
		    (atomic || space < so->so_snd.sb_lowat || space < clen)) {
			if (so->so_state & SS_NBIO)
				snderr(EWOULDBLOCK);
			sbunlock(&so->so_snd);
			error = sbwait(&so->so_snd);
			splx(s);
			if (error)
				goto out;
			goto restart;
		}
		splx(s);
		mp = &top;
		space -= clen;
		do {
			if (uio == NULL) {
				/*
				 * Data is prepackaged in "top".
				 */
				resid = 0;
				if (flags & MSG_EOR)
					top->m_flags |= M_EOR;
			} else do {
				if (top == 0) {
					MGETHDR(m, M_WAIT, MT_DATA);
					mlen = MHLEN;
					m->m_pkthdr.len = 0;
					m->m_pkthdr.rcvif = (struct ifnet *)0;
				} else {
					MGET(m, M_WAIT, MT_DATA);
					mlen = MLEN;
				}
				if (use_sosend_loan &&
				    uio->uio_iov->iov_len >= SOCK_LOAN_THRESH &&
				    space >= SOCK_LOAN_THRESH &&
				    (len = sosend_loan(so, uio, m,
						       space)) != 0) {
					SOSEND_COUNTER_INCR(&sosend_loan_big);
					space -= len;
					goto have_data;
				}
				if (resid >= MINCLSIZE && space >= MCLBYTES) {
					SOSEND_COUNTER_INCR(&sosend_copy_big);
					MCLGET(m, M_WAIT);
					if ((m->m_flags & M_EXT) == 0)
						goto nopages;
					mlen = MCLBYTES;
					if (atomic && top == 0) {
						len = lmin(MCLBYTES - max_hdr,
						    resid);
						m->m_data += max_hdr;
					} else
						len = lmin(MCLBYTES, resid);
					space -= len;
				} else {
 nopages:
					SOSEND_COUNTER_INCR(&sosend_copy_small);
					len = lmin(lmin(mlen, resid), space);
					space -= len;
					/*
					 * For datagram protocols, leave room
					 * for protocol headers in first mbuf.
					 */
					if (atomic && top == 0 && len < mlen)
						MH_ALIGN(m, len);
				}
				error = uiomove(mtod(m, caddr_t), (int)len,
				    uio);
 have_data:
				resid = uio->uio_resid;
				m->m_len = len;
				*mp = m;
				top->m_pkthdr.len += len;
				if (error)
					goto release;
				mp = &m->m_next;
				if (resid <= 0) {
					if (flags & MSG_EOR)
						top->m_flags |= M_EOR;
					break;
				}
			} while (space > 0 && atomic);
			
			s = splsoftnet();

			if (so->so_state & SS_CANTSENDMORE)
				snderr(EPIPE);

			if (dontroute)
				so->so_options |= SO_DONTROUTE;
			if (resid > 0)
				so->so_state |= SS_MORETOCOME;
			error = (*so->so_proto->pr_usrreq)(so,
			    (flags & MSG_OOB) ? PRU_SENDOOB : PRU_SEND,
			    top, addr, control, p);
			if (dontroute)
				so->so_options &= ~SO_DONTROUTE;
			if (resid > 0)
				so->so_state &= ~SS_MORETOCOME;
			splx(s);

			clen = 0;
			control = 0;
			top = 0;
			mp = &top;
			if (error)
				goto release;
		} while (resid && space > 0);
	} while (resid);

 release:
	sbunlock(&so->so_snd);
 out:
	if (top)
		m_freem(top);
	if (control)
		m_freem(control);
	return (error);
}

/*
 * Implement receive operations on a socket.
 * We depend on the way that records are added to the sockbuf
 * by sbappend*.  In particular, each record (mbufs linked through m_next)
 * must begin with an address if the protocol so specifies,
 * followed by an optional mbuf or mbufs containing ancillary data,
 * and then zero or more mbufs of data.
 * In order to avoid blocking network interrupts for the entire time here,
 * we splx() while doing the actual copy to user space.
 * Although the sockbuf is locked, new data may still be appended,
 * and thus we must maintain consistency of the sockbuf during that time.
 *
 * The caller may receive the data as a single mbuf chain by supplying
 * an mbuf **mp0 for use in returning the chain.  The uio is then used
 * only for the count in uio_resid.
 */
int
soreceive(struct socket *so, struct mbuf **paddr, struct uio *uio,
	struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
{
	struct mbuf	*m, **mp;
	int		flags, len, error, s, offset, moff, type, orig_resid;
	struct protosw	*pr;
	struct mbuf	*nextrecord;
	int		mbuf_removed = 0;

	pr = so->so_proto;
	mp = mp0;
	type = 0;
	orig_resid = uio->uio_resid;
	if (paddr)
		*paddr = 0;
	if (controlp)
		*controlp = 0;
	if (flagsp)
		flags = *flagsp &~ MSG_EOR;
	else
		flags = 0;

	if ((flags & MSG_DONTWAIT) == 0)
		sodopendfree(so);

	if (flags & MSG_OOB) {
		m = m_get(M_WAIT, MT_DATA);
		error = (*pr->pr_usrreq)(so, PRU_RCVOOB, m,
		    (struct mbuf *)(long)(flags & MSG_PEEK), (struct mbuf *)0,
		    (struct proc *)0);
		if (error)
			goto bad;
		do {
			error = uiomove(mtod(m, caddr_t),
			    (int) min(uio->uio_resid, m->m_len), uio);
			m = m_free(m);
		} while (uio->uio_resid && error == 0 && m);
 bad:
		if (m)
			m_freem(m);
		return (error);
	}
	if (mp)
		*mp = (struct mbuf *)0;
	if (so->so_state & SS_ISCONFIRMING && uio->uio_resid)
		(*pr->pr_usrreq)(so, PRU_RCVD, (struct mbuf *)0,
		    (struct mbuf *)0, (struct mbuf *)0, (struct proc *)0);

 restart:
	if ((error = sblock(&so->so_rcv, SBLOCKWAIT(flags))) != 0)
		return (error);
	s = splsoftnet();

	m = so->so_rcv.sb_mb;
	/*
	 * If we have less data than requested, block awaiting more
	 * (subject to any timeout) if:
	 *   1. the current count is less than the low water mark,
	 *   2. MSG_WAITALL is set, and it is possible to do the entire
	 *	receive operation at once if we block (resid <= hiwat), or
	 *   3. MSG_DONTWAIT is not set.
	 * If MSG_WAITALL is set but resid is larger than the receive buffer,
	 * we have to do the receive in sections, and thus risk returning
	 * a short count if a timeout or signal occurs after we start.
	 */
	if (m == 0 || (((flags & MSG_DONTWAIT) == 0 &&
	    so->so_rcv.sb_cc < uio->uio_resid) &&
	    (so->so_rcv.sb_cc < so->so_rcv.sb_lowat ||
	    ((flags & MSG_WAITALL) && uio->uio_resid <= so->so_rcv.sb_hiwat)) &&
	    m->m_nextpkt == 0 && (pr->pr_flags & PR_ATOMIC) == 0)) {
#ifdef DIAGNOSTIC
		if (m == 0 && so->so_rcv.sb_cc)
			panic("receive 1");
#endif
		if (so->so_error) {
			if (m)
				goto dontblock;
			error = so->so_error;
			if ((flags & MSG_PEEK) == 0)
				so->so_error = 0;
			goto release;
		}
		if (so->so_state & SS_CANTRCVMORE) {
			if (m)
				goto dontblock;
			else
				goto release;
		}
		for (; m; m = m->m_next)
			if (m->m_type == MT_OOBDATA  || (m->m_flags & M_EOR)) {
				m = so->so_rcv.sb_mb;
				goto dontblock;
			}
		if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
		    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
			error = ENOTCONN;
			goto release;
		}
		if (uio->uio_resid == 0)
			goto release;
		if ((so->so_state & SS_NBIO) || (flags & MSG_DONTWAIT)) {
			error = EWOULDBLOCK;
			goto release;
		}
		sbunlock(&so->so_rcv);
		error = sbwait(&so->so_rcv);
		splx(s);
		if (error)
			return (error);
		goto restart;
	}
 dontblock:
#ifdef notyet /* XXXX */
	if (uio->uio_procp)
		uio->uio_procp->p_stats->p_ru.ru_msgrcv++;
#endif
	nextrecord = m->m_nextpkt;
	if (pr->pr_flags & PR_ADDR) {
#ifdef DIAGNOSTIC
		if (m->m_type != MT_SONAME)
			panic("receive 1a");
#endif
		orig_resid = 0;
		if (flags & MSG_PEEK) {
			if (paddr)
				*paddr = m_copy(m, 0, m->m_len);
			m = m->m_next;
		} else {
			sbfree(&so->so_rcv, m);
			mbuf_removed = 1;
			if (paddr) {
				*paddr = m;
				so->so_rcv.sb_mb = m->m_next;
				m->m_next = 0;
				m = so->so_rcv.sb_mb;
			} else {
				MFREE(m, so->so_rcv.sb_mb);
				m = so->so_rcv.sb_mb;
			}
		}
	}
	while (m && m->m_type == MT_CONTROL && error == 0) {
		if (flags & MSG_PEEK) {
			if (controlp)
				*controlp = m_copy(m, 0, m->m_len);
			m = m->m_next;
		} else {
			sbfree(&so->so_rcv, m);
			mbuf_removed = 1;
			if (controlp) {
				if (pr->pr_domain->dom_externalize &&
				    mtod(m, struct cmsghdr *)->cmsg_type ==
				    SCM_RIGHTS)
					error = (*pr->pr_domain->dom_externalize)(m);
				*controlp = m;
				so->so_rcv.sb_mb = m->m_next;
				m->m_next = 0;
				m = so->so_rcv.sb_mb;
			} else {
				MFREE(m, so->so_rcv.sb_mb);
				m = so->so_rcv.sb_mb;
			}
		}
		if (controlp) {
			orig_resid = 0;
			controlp = &(*controlp)->m_next;
		}
	}
	if (m) {
		if ((flags & MSG_PEEK) == 0)
			m->m_nextpkt = nextrecord;
		type = m->m_type;
		if (type == MT_OOBDATA)
			flags |= MSG_OOB;
	}
	moff = 0;
	offset = 0;
	while (m && uio->uio_resid > 0 && error == 0) {
		if (m->m_type == MT_OOBDATA) {
			if (type != MT_OOBDATA)
				break;
		} else if (type == MT_OOBDATA)
			break;
#ifdef DIAGNOSTIC
		else if (m->m_type != MT_DATA && m->m_type != MT_HEADER)
			panic("receive 3");
#endif
		so->so_state &= ~SS_RCVATMARK;
		len = uio->uio_resid;
		if (so->so_oobmark && len > so->so_oobmark - offset)
			len = so->so_oobmark - offset;
		if (len > m->m_len - moff)
			len = m->m_len - moff;
		/*
		 * If mp is set, just pass back the mbufs.
		 * Otherwise copy them out via the uio, then free.
		 * Sockbuf must be consistent here (points to current mbuf,
		 * it points to next record) when we drop priority;
		 * we must note any additions to the sockbuf when we
		 * block interrupts again.
		 */
		if (mp == 0) {
			splx(s);
			error = uiomove(mtod(m, caddr_t) + moff, (int)len, uio);
			s = splsoftnet();
			if (error) {
				/*
				 * If any part of the record has been removed
				 * (such as the MT_SONAME mbuf, which will
				 * happen when PR_ADDR, and thus also
				 * PR_ATOMIC, is set), then drop the entire
				 * record to maintain the atomicity of the
				 * receive operation.
				 *
				 * This avoids a later panic("receive 1a")
				 * when compiled with DIAGNOSTIC.
				 */
				if (m && mbuf_removed
				    && (pr->pr_flags & PR_ATOMIC))
					(void) sbdroprecord(&so->so_rcv);

				goto release;
			}
		} else
			uio->uio_resid -= len;
		if (len == m->m_len - moff) {
			if (m->m_flags & M_EOR)
				flags |= MSG_EOR;
			if (flags & MSG_PEEK) {
				m = m->m_next;
				moff = 0;
			} else {
				nextrecord = m->m_nextpkt;
				sbfree(&so->so_rcv, m);
				if (mp) {
					*mp = m;
					mp = &m->m_next;
					so->so_rcv.sb_mb = m = m->m_next;
					*mp = (struct mbuf *)0;
				} else {
					MFREE(m, so->so_rcv.sb_mb);
					m = so->so_rcv.sb_mb;
				}
				if (m)
					m->m_nextpkt = nextrecord;
			}
		} else {
			if (flags & MSG_PEEK)
				moff += len;
			else {
				if (mp)
					*mp = m_copym(m, 0, len, M_WAIT);
				m->m_data += len;
				m->m_len -= len;
				so->so_rcv.sb_cc -= len;
			}
		}
		if (so->so_oobmark) {
			if ((flags & MSG_PEEK) == 0) {
				so->so_oobmark -= len;
				if (so->so_oobmark == 0) {
					so->so_state |= SS_RCVATMARK;
					break;
				}
			} else {
				offset += len;
				if (offset == so->so_oobmark)
					break;
			}
		}
		if (flags & MSG_EOR)
			break;
		/*
		 * If the MSG_WAITALL flag is set (for non-atomic socket),
		 * we must not quit until "uio->uio_resid == 0" or an error
		 * termination.  If a signal/timeout occurs, return
		 * with a short count but without error.
		 * Keep sockbuf locked against other readers.
		 */
		while (flags & MSG_WAITALL && m == 0 && uio->uio_resid > 0 &&
		    !sosendallatonce(so) && !nextrecord) {
			if (so->so_error || so->so_state & SS_CANTRCVMORE)
				break;
			/*
			 * If we are peeking and the socket receive buffer is
			 * full, stop since we can't get more data to peek at.
			 */
			if ((flags & MSG_PEEK) && sbspace(&so->so_rcv) <= 0)
				break;
			/*
			 * If we've drained the socket buffer, tell the
			 * protocol in case it needs to do something to
			 * get it filled again.
			 */
			if ((pr->pr_flags & PR_WANTRCVD) && so->so_pcb)
				(*pr->pr_usrreq)(so, PRU_RCVD,
				    (struct mbuf *)0,
				    (struct mbuf *)(long)flags,
				    (struct mbuf *)0,
				    (struct proc *)0);
			error = sbwait(&so->so_rcv);
			if (error) {
				sbunlock(&so->so_rcv);
				splx(s);
				return (0);
			}
			if ((m = so->so_rcv.sb_mb) != NULL)
				nextrecord = m->m_nextpkt;
		}
	}

	if (m && pr->pr_flags & PR_ATOMIC) {
		flags |= MSG_TRUNC;
		if ((flags & MSG_PEEK) == 0)
			(void) sbdroprecord(&so->so_rcv);
	}
	if ((flags & MSG_PEEK) == 0) {
		if (m == 0)
			so->so_rcv.sb_mb = nextrecord;
		if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
			(*pr->pr_usrreq)(so, PRU_RCVD, (struct mbuf *)0,
			    (struct mbuf *)(long)flags, (struct mbuf *)0,
			    (struct proc *)0);
	}
	if (orig_resid == uio->uio_resid && orig_resid &&
	    (flags & MSG_EOR) == 0 && (so->so_state & SS_CANTRCVMORE) == 0) {
		sbunlock(&so->so_rcv);
		splx(s);
		goto restart;
	}
		
	if (flagsp)
		*flagsp |= flags;
 release:
	sbunlock(&so->so_rcv);
	splx(s);
	return (error);
}

int
soshutdown(struct socket *so, int how)
{
	struct protosw	*pr;

	pr = so->so_proto;
	if (!(how == SHUT_RD || how == SHUT_WR || how == SHUT_RDWR))
		return (EINVAL);

	if (how == SHUT_RD || how == SHUT_RDWR)
		sorflush(so);
	if (how == SHUT_WR || how == SHUT_RDWR)
		return (*pr->pr_usrreq)(so, PRU_SHUTDOWN, (struct mbuf *)0,
		    (struct mbuf *)0, (struct mbuf *)0, (struct proc *)0);
	return (0);
}

void
sorflush(struct socket *so)
{
	struct sockbuf	*sb, asb;
	struct protosw	*pr;
	int		s;

	sb = &so->so_rcv;
	pr = so->so_proto;
	sb->sb_flags |= SB_NOINTR;
	(void) sblock(sb, M_WAITOK);
	s = splnet();
	socantrcvmore(so);
	sbunlock(sb);
	asb = *sb;
	memset((caddr_t)sb, 0, sizeof(*sb));
	splx(s);
	if (pr->pr_flags & PR_RIGHTS && pr->pr_domain->dom_dispose)
		(*pr->pr_domain->dom_dispose)(asb.sb_mb);
	sbrelease(&asb);
}

int
sosetopt(struct socket *so, int level, int optname, struct mbuf *m0)
{
	int		error;
	struct mbuf	*m;

	error = 0;
	m = m0;
	if (level != SOL_SOCKET) {
		if (so->so_proto && so->so_proto->pr_ctloutput)
			return ((*so->so_proto->pr_ctloutput)
				  (PRCO_SETOPT, so, level, optname, &m0));
		error = ENOPROTOOPT;
	} else {
		switch (optname) {

		case SO_LINGER:
			if (m == NULL || m->m_len != sizeof(struct linger)) {
				error = EINVAL;
				goto bad;
			}
			so->so_linger = mtod(m, struct linger *)->l_linger;
			/* fall thru... */

		case SO_DEBUG:
		case SO_KEEPALIVE:
		case SO_DONTROUTE:
		case SO_USELOOPBACK:
		case SO_BROADCAST:
		case SO_REUSEADDR:
		case SO_REUSEPORT:
		case SO_OOBINLINE:
		case SO_TIMESTAMP:
			if (m == NULL || m->m_len < sizeof(int)) {
				error = EINVAL;
				goto bad;
			}
			if (*mtod(m, int *))
				so->so_options |= optname;
			else
				so->so_options &= ~optname;
			break;

		case SO_SNDBUF:
		case SO_RCVBUF:
		case SO_SNDLOWAT:
		case SO_RCVLOWAT:
		    {
			int optval;

			if (m == NULL || m->m_len < sizeof(int)) {
				error = EINVAL;
				goto bad;
			}

			/*
			 * Values < 1 make no sense for any of these
			 * options, so disallow them.
			 */
			optval = *mtod(m, int *);
			if (optval < 1) {
				error = EINVAL;
				goto bad;
			}

			switch (optname) {

			case SO_SNDBUF:
			case SO_RCVBUF:
				if (sbreserve(optname == SO_SNDBUF ?
				    &so->so_snd : &so->so_rcv,
				    (u_long) optval) == 0) {
					error = ENOBUFS;
					goto bad;
				}
				break;

			/*
			 * Make sure the low-water is never greater than
			 * the high-water.
			 */
			case SO_SNDLOWAT:
				so->so_snd.sb_lowat =
				    (optval > so->so_snd.sb_hiwat) ?
				    so->so_snd.sb_hiwat : optval;
				break;
			case SO_RCVLOWAT:
				so->so_rcv.sb_lowat =
				    (optval > so->so_rcv.sb_hiwat) ?
				    so->so_rcv.sb_hiwat : optval;
				break;
			}
			break;
		    }

		case SO_SNDTIMEO:
		case SO_RCVTIMEO:
		    {
			struct timeval *tv;
			short val;

			if (m == NULL || m->m_len < sizeof(*tv)) {
				error = EINVAL;
				goto bad;
			}
			tv = mtod(m, struct timeval *);
			if (tv->tv_sec * hz + tv->tv_usec / tick > SHRT_MAX) {
				error = EDOM;
				goto bad;
			}
			val = tv->tv_sec * hz + tv->tv_usec / tick;

			switch (optname) {

			case SO_SNDTIMEO:
				so->so_snd.sb_timeo = val;
				break;
			case SO_RCVTIMEO:
				so->so_rcv.sb_timeo = val;
				break;
			}
			break;
		    }

		default:
			error = ENOPROTOOPT;
			break;
		}
		if (error == 0 && so->so_proto && so->so_proto->pr_ctloutput) {
			(void) ((*so->so_proto->pr_ctloutput)
				  (PRCO_SETOPT, so, level, optname, &m0));
			m = NULL;	/* freed by protocol */
		}
	}
 bad:
	if (m)
		(void) m_free(m);
	return (error);
}

int
sogetopt(struct socket *so, int level, int optname, struct mbuf **mp)
{
	struct mbuf	*m;

	if (level != SOL_SOCKET) {
		if (so->so_proto && so->so_proto->pr_ctloutput) {
			return ((*so->so_proto->pr_ctloutput)
				  (PRCO_GETOPT, so, level, optname, mp));
		} else
			return (ENOPROTOOPT);
	} else {
		m = m_get(M_WAIT, MT_SOOPTS);
		m->m_len = sizeof(int);

		switch (optname) {

		case SO_LINGER:
			m->m_len = sizeof(struct linger);
			mtod(m, struct linger *)->l_onoff =
				so->so_options & SO_LINGER;
			mtod(m, struct linger *)->l_linger = so->so_linger;
			break;

		case SO_USELOOPBACK:
		case SO_DONTROUTE:
		case SO_DEBUG:
		case SO_KEEPALIVE:
		case SO_REUSEADDR:
		case SO_REUSEPORT:
		case SO_BROADCAST:
		case SO_OOBINLINE:
		case SO_TIMESTAMP:
			*mtod(m, int *) = so->so_options & optname;
			break;

		case SO_TYPE:
			*mtod(m, int *) = so->so_type;
			break;

		case SO_ERROR:
			*mtod(m, int *) = so->so_error;
			so->so_error = 0;
			break;

		case SO_SNDBUF:
			*mtod(m, int *) = so->so_snd.sb_hiwat;
			break;

		case SO_RCVBUF:
			*mtod(m, int *) = so->so_rcv.sb_hiwat;
			break;

		case SO_SNDLOWAT:
			*mtod(m, int *) = so->so_snd.sb_lowat;
			break;

		case SO_RCVLOWAT:
			*mtod(m, int *) = so->so_rcv.sb_lowat;
			break;

		case SO_SNDTIMEO:
		case SO_RCVTIMEO:
		    {
			int val = (optname == SO_SNDTIMEO ?
			     so->so_snd.sb_timeo : so->so_rcv.sb_timeo);

			m->m_len = sizeof(struct timeval);
			mtod(m, struct timeval *)->tv_sec = val / hz;
			mtod(m, struct timeval *)->tv_usec =
			    (val % hz) * tick;
			break;
		    }

		default:
			(void)m_free(m);
			return (ENOPROTOOPT);
		}
		*mp = m;
		return (0);
	}
}

void
sohasoutofband(struct socket *so)
{
	struct proc *p;

	if (so->so_pgid < 0)
		gsignal(-so->so_pgid, SIGURG);
	else if (so->so_pgid > 0 && (p = pfind(so->so_pgid)) != 0)
		psignal(p, SIGURG);
	selwakeup(&so->so_rcv.sb_sel);
}