sys/kern/uipc_syscalls.c

/*
 * Copyright (c) 1982, 1986, 1989, 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * sendfile(2) and related extensions:
 * Copyright (c) 1998, David Greenman. 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_syscalls.c	8.4 (Berkeley) 2/21/94
 * $FreeBSD: src/sys/kern/uipc_syscalls.c,v 1.65.2.17 2003/04/04 17:11:16 tegge Exp $
 * $DragonFly: src/sys/kern/uipc_syscalls.c,v 1.27 2004/03/14 14:35:23 joerg Exp $
 */

#include "opt_ktrace.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/sysproto.h>
#include <sys/malloc.h>
#include <sys/filedesc.h>
#include <sys/event.h>
#include <sys/proc.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/filio.h>
#include <sys/kern_syscall.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/sfbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/socketops.h>
#include <sys/uio.h>
#include <sys/vnode.h>
#include <sys/lock.h>
#include <sys/mount.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
#include <vm/vm.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_kern.h>
#include <vm/vm_extern.h>
#include <sys/file2.h>
#include <sys/signalvar.h>

/*
 * System call interface to the socket abstraction.
 */

extern	struct fileops socketops;

/*
 * socket_args(int domain, int type, int protocol)
 */
int
kern_socket(int domain, int type, int protocol, int *res)
{
	struct thread *td = curthread;
	struct proc *p = td->td_proc;
	struct filedesc *fdp;
	struct socket *so;
	struct file *fp;
	int fd, error;

	KKASSERT(p);
	fdp = p->p_fd;

	error = falloc(p, &fp, &fd);
	if (error)
		return (error);
	fhold(fp);
	error = socreate(domain, &so, type, protocol, td);
	if (error) {
		if (fdp->fd_ofiles[fd] == fp) {
			fdp->fd_ofiles[fd] = NULL;
			fdrop(fp, td);
		}
	} else {
		fp->f_data = (caddr_t)so;
		fp->f_flag = FREAD|FWRITE;
		fp->f_ops = &socketops;
		fp->f_type = DTYPE_SOCKET;
		*res = fd;
	}
	fdrop(fp, td);
	return (error);
}

int
socket(struct socket_args *uap)
{
	int error;

	error = kern_socket(uap->domain, uap->type, uap->protocol,
	    &uap->sysmsg_result);

	return (error);
}

int
kern_bind(int s, struct sockaddr *sa)
{
	struct thread *td = curthread;
	struct proc *p = td->td_proc;
	struct file *fp;
	int error;

	KKASSERT(p);
	error = holdsock(p->p_fd, s, &fp);
	if (error)
		return (error);
	error = sobind((struct socket *)fp->f_data, sa, td);
	fdrop(fp, td);
	return (error);
}

/*
 * bind_args(int s, caddr_t name, int namelen)
 */
int
bind(struct bind_args *uap)
{
	struct sockaddr *sa;
	int error;

	error = getsockaddr(&sa, uap->name, uap->namelen);
	if (error)
		return (error);
	error = kern_bind(uap->s, sa);
	FREE(sa, M_SONAME);

	return (error);
}

int
kern_listen(int s, int backlog)
{
	struct thread *td = curthread;
	struct proc *p = td->td_proc;
	struct file *fp;
	int error;

	KKASSERT(p);
	error = holdsock(p->p_fd, s, &fp);
	if (error)
		return (error);
	error = solisten((struct socket *)fp->f_data, backlog, td);
	fdrop(fp, td);
	return(error);
}

/*
 * listen_args(int s, int backlog)
 */
int
listen(struct listen_args *uap)
{
	int error;

	error = kern_listen(uap->s, uap->backlog);
	return (error);
}

/*
 * The second argument to kern_accept() is a handle to a struct sockaddr.
 * This allows kern_accept() to return a pointer to an allocated struct
 * sockaddr which must be freed later with FREE().  The caller must
 * initialize *name to NULL.
 */
int
kern_accept(int s, struct sockaddr **name, int *namelen, int *res)
{
	struct thread *td = curthread;
	struct proc *p = td->td_proc;
	struct filedesc *fdp = p->p_fd;
	struct file *lfp = NULL;
	struct file *nfp = NULL;
	struct sockaddr *sa;
	int error, s1;
	struct socket *head, *so;
	int fd;
	u_int fflag;		/* type must match fp->f_flag */
	int tmp;

	if (name && namelen && *namelen < 0)
		return (EINVAL);

	error = holdsock(fdp, s, &lfp);
	if (error)
		return (error);
	s1 = splnet();
	head = (struct socket *)lfp->f_data;
	if ((head->so_options & SO_ACCEPTCONN) == 0) {
		splx(s1);
		error = EINVAL;
		goto done;
	}
	while (TAILQ_EMPTY(&head->so_comp) && head->so_error == 0) {
		if (head->so_state & SS_CANTRCVMORE) {
			head->so_error = ECONNABORTED;
			break;
		}
		if ((head->so_state & SS_NBIO) != 0) {
			head->so_error = EWOULDBLOCK;
			break;
		}
		error = tsleep((caddr_t)&head->so_timeo, PCATCH, "accept", 0);
		if (error) {
			splx(s1);
			goto done;
		}
	}
	if (head->so_error) {
		error = head->so_error;
		head->so_error = 0;
		splx(s1);
		goto done;
	}

	/*
	 * At this point we know that there is at least one connection
	 * ready to be accepted. Remove it from the queue prior to
	 * allocating the file descriptor for it since falloc() may
	 * block allowing another process to accept the connection
	 * instead.
	 */
	so = TAILQ_FIRST(&head->so_comp);
	TAILQ_REMOVE(&head->so_comp, so, so_list);
	head->so_qlen--;

	fflag = lfp->f_flag;
	error = falloc(p, &nfp, &fd);
	if (error) {
		/*
		 * Probably ran out of file descriptors. Put the
		 * unaccepted connection back onto the queue and
		 * do another wakeup so some other process might
		 * have a chance at it.
		 */
		TAILQ_INSERT_HEAD(&head->so_comp, so, so_list);
		head->so_qlen++;
		wakeup_one(&head->so_timeo);
		splx(s1);
		goto done;
	}
	fhold(nfp);
	*res = fd;

	/* connection has been removed from the listen queue */
	KNOTE(&head->so_rcv.sb_sel.si_note, 0);

	so->so_state &= ~SS_COMP;
	so->so_head = NULL;
	if (head->so_sigio != NULL)
		fsetown(fgetown(head->so_sigio), &so->so_sigio);

	nfp->f_data = (caddr_t)so;
	nfp->f_flag = fflag;
	nfp->f_ops = &socketops;
	nfp->f_type = DTYPE_SOCKET;
	/* Sync socket nonblocking/async state with file flags */
	tmp = fflag & FNONBLOCK;
	(void) fo_ioctl(nfp, FIONBIO, (caddr_t)&tmp, td);
	tmp = fflag & FASYNC;
	(void) fo_ioctl(nfp, FIOASYNC, (caddr_t)&tmp, td);

	sa = NULL;
	error = soaccept(so, &sa);

	/*
	 * Set the returned name and namelen as applicable.  Set the returned
	 * namelen to 0 for older code which might ignore the return value
	 * from accept.
	 */
	if (error == 0) {
		if (sa && name && namelen) {
			if (*namelen > sa->sa_len)
				*namelen = sa->sa_len;
			*name = sa;
		} else {
			if (sa)
				FREE(sa, M_SONAME);
		}
	}

	/*
	 * close the new descriptor, assuming someone hasn't ripped it
	 * out from under us.  Note that *res is normally ignored if an
	 * error is returned but a syscall message will still have access
	 * to the result code.
	 */
	if (error) {
		*res = -1;
		if (fdp->fd_ofiles[fd] == nfp) {
			fdp->fd_ofiles[fd] = NULL;
			fdrop(nfp, td);
		}
	}
	splx(s1);

	/*
	 * Release explicitly held references before returning.
	 */
done:
	if (nfp != NULL)
		fdrop(nfp, td);
	fdrop(lfp, td);
	return (error);
}

/*
 * accept_args(int s, caddr_t name, int *anamelen)
 */
int
accept(struct accept_args *uap)
{
	struct sockaddr *sa = NULL;
	int sa_len;
	int error;

	if (uap->name) {
		error = copyin(uap->anamelen, &sa_len, sizeof(sa_len));
		if (error)
			return (error);

		error = kern_accept(uap->s, &sa, &sa_len, &uap->sysmsg_result);

		if (error == 0)
			error = copyout(sa, uap->name, sa_len);
		if (error == 0) {
			error = copyout(&sa_len, uap->anamelen,
			    sizeof(*uap->anamelen));
		}
		if (sa)
			FREE(sa, M_SONAME);
	} else {
		error = kern_accept(uap->s, NULL, 0, &uap->sysmsg_result);
	}
	return (error);
}

int
kern_connect(int s, struct sockaddr *sa)
{
	struct thread *td = curthread;
	struct proc *p = td->td_proc;
	struct file *fp;
	struct socket *so;
	int error;

	error = holdsock(p->p_fd, s, &fp);
	if (error)
		return (error);
	so = (struct socket *)fp->f_data;
	if ((so->so_state & SS_NBIO) && (so->so_state & SS_ISCONNECTING)) {
		error = EALREADY;
		goto done;
	}
	error = soconnect(so, sa, td);
	if (error)
		goto bad;
	if ((so->so_state & SS_NBIO) && (so->so_state & SS_ISCONNECTING)) {
		error = EINPROGRESS;
		goto done;
	}
	s = splnet();
	while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
		error = tsleep((caddr_t)&so->so_timeo, PCATCH, "connec", 0);
		if (error)
			break;
	}
	if (error == 0) {
		error = so->so_error;
		so->so_error = 0;
	}
	splx(s);
bad:
	so->so_state &= ~SS_ISCONNECTING;
	if (error == ERESTART)
		error = EINTR;
done:
	fdrop(fp, td);
	return (error);
}

/*
 * connect_args(int s, caddr_t name, int namelen)
 */
int
connect(struct connect_args *uap)
{
	struct sockaddr *sa;
	int error;

	error = getsockaddr(&sa, uap->name, uap->namelen);
	if (error)
		return (error);
	error = kern_connect(uap->s, sa);
	FREE(sa, M_SONAME);

	return (error);
}

int
kern_socketpair(int domain, int type, int protocol, int *sv)
{
	struct thread *td = curthread;
	struct proc *p = td->td_proc;
	struct filedesc *fdp;
	struct file *fp1, *fp2;
	struct socket *so1, *so2;
	int fd, error;

	KKASSERT(p);
	fdp = p->p_fd;
	error = socreate(domain, &so1, type, protocol, td);
	if (error)
		return (error);
	error = socreate(domain, &so2, type, protocol, td);
	if (error)
		goto free1;
	error = falloc(p, &fp1, &fd);
	if (error)
		goto free2;
	fhold(fp1);
	sv[0] = fd;
	fp1->f_data = (caddr_t)so1;
	error = falloc(p, &fp2, &fd);
	if (error)
		goto free3;
	fhold(fp2);
	fp2->f_data = (caddr_t)so2;
	sv[1] = fd;
	error = soconnect2(so1, so2);
	if (error)
		goto free4;
	if (type == SOCK_DGRAM) {
		/*
		 * Datagram socket connection is asymmetric.
		 */
		 error = soconnect2(so2, so1);
		 if (error)
			goto free4;
	}
	fp1->f_flag = fp2->f_flag = FREAD|FWRITE;
	fp1->f_ops = fp2->f_ops = &socketops;
	fp1->f_type = fp2->f_type = DTYPE_SOCKET;
	fdrop(fp1, td);
	fdrop(fp2, td);
	return (error);
free4:
	if (fdp->fd_ofiles[sv[1]] == fp2) {
		fdp->fd_ofiles[sv[1]] = NULL;
		fdrop(fp2, td);
	}
	fdrop(fp2, td);
free3:
	if (fdp->fd_ofiles[sv[0]] == fp1) {
		fdp->fd_ofiles[sv[0]] = NULL;
		fdrop(fp1, td);
	}
	fdrop(fp1, td);
free2:
	(void)soclose(so2);
free1:
	(void)soclose(so1);
	return (error);
}

/*
 * socketpair(int domain, int type, int protocol, int *rsv)
 */
int
socketpair(struct socketpair_args *uap)
{
	int error, sockv[2];

	error = kern_socketpair(uap->domain, uap->type, uap->protocol, sockv);

	if (error == 0)
		error = copyout(sockv, uap->rsv, sizeof(sockv));
	return (error);
}

int
kern_sendmsg(int s, struct sockaddr *sa, struct uio *auio,
    struct mbuf *control, int flags, int *res)
{
	struct thread *td = curthread;
	struct proc *p = td->td_proc;
	struct file *fp;
	int len, error;
	struct socket *so;
#ifdef KTRACE
	struct iovec *ktriov = NULL;
	struct uio ktruio;
#endif

	error = holdsock(p->p_fd, s, &fp);
	if (error)
		return (error);
	if (auio->uio_resid < 0) {
		error = EINVAL;
		goto done;
	}
#ifdef KTRACE
	if (KTRPOINT(td, KTR_GENIO)) {
		int iovlen = auio->uio_iovcnt * sizeof (struct iovec);

		MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
		bcopy((caddr_t)auio->uio_iov, (caddr_t)ktriov, iovlen);
		ktruio = *auio;
	}
#endif
	len = auio->uio_resid;
	so = (struct socket *)fp->f_data;
	error = so_pru_sosend(so, sa, auio, NULL, control, flags, td);
	if (error) {
		if (auio->uio_resid != len && (error == ERESTART ||
		    error == EINTR || error == EWOULDBLOCK))
			error = 0;
		if (error == EPIPE)
			psignal(p, SIGPIPE);
	}
#ifdef KTRACE
	if (ktriov != NULL) {
		if (error == 0) {
			ktruio.uio_iov = ktriov;
			ktruio.uio_resid = len - auio->uio_resid;
			ktrgenio(p->p_tracep, s, UIO_WRITE, &ktruio, error);
		}
		FREE(ktriov, M_TEMP);
	}
#endif
	if (error == 0)
		*res  = len - auio->uio_resid;
done:
	fdrop(fp, td);
	return (error);
}

/*
 * sendto_args(int s, caddr_t buf, size_t len, int flags, caddr_t to, int tolen)
 */
int
sendto(struct sendto_args *uap)
{
	struct thread *td = curthread;
	struct uio auio;
	struct iovec aiov;
	struct sockaddr *sa = NULL;
	int error;

	if (uap->to) {
		error = getsockaddr(&sa, uap->to, uap->tolen);
		if (error)
			return (error);
	}
	aiov.iov_base = uap->buf;
	aiov.iov_len = uap->len;
	auio.uio_iov = &aiov;
	auio.uio_iovcnt = 1;
	auio.uio_offset = 0;
	auio.uio_resid = uap->len;
	auio.uio_segflg = UIO_USERSPACE;
	auio.uio_rw = UIO_WRITE;
	auio.uio_td = td;

	error = kern_sendmsg(uap->s, sa, &auio, NULL, uap->flags,
	    &uap->sysmsg_result);

	if (sa)
		FREE(sa, M_SONAME);
	return (error);
}

/*
 * sendmsg_args(int s, caddr_t msg, int flags)
 */
int
sendmsg(struct sendmsg_args *uap)
{
	struct thread *td = curthread;
	struct msghdr msg;
	struct uio auio;
	struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
	struct sockaddr *sa = NULL;
	struct mbuf *control = NULL;
	int error;

	error = copyin(uap->msg, (caddr_t)&msg, sizeof(msg));
	if (error)
		return (error);

	/*
	 * Conditionally copyin msg.msg_name.
	 */
	if (msg.msg_name) {
		error = getsockaddr(&sa, msg.msg_name, msg.msg_namelen);
		if (error)
			return (error);
	}

	/*
	 * Populate auio.
	 */
	error = iovec_copyin(msg.msg_iov, &iov, aiov, msg.msg_iovlen,
	    &auio.uio_resid);
	if (error)
		goto cleanup;
	auio.uio_iov = iov;
	auio.uio_iovcnt = msg.msg_iovlen;
	auio.uio_offset = 0;
	auio.uio_segflg = UIO_USERSPACE;
	auio.uio_rw = UIO_WRITE;
	auio.uio_td = td;

	/*
	 * Conditionally copyin msg.msg_control.
	 */
	if (msg.msg_control) {
		if (msg.msg_controllen < sizeof(struct cmsghdr) ||
		    msg.msg_controllen > MLEN) {
			error = EINVAL;
			goto cleanup;
		}
		control = m_get(M_WAIT, MT_CONTROL);
		if (control == NULL) {
			error = ENOBUFS;
			goto cleanup;
		}
		control->m_len = msg.msg_controllen;
		error = copyin(msg.msg_control, mtod(control, caddr_t),
		    msg.msg_controllen);
		if (error) {
			m_free(control);
			goto cleanup;
		}
	}

	error = kern_sendmsg(uap->s, sa, &auio, control, uap->flags,
	    &uap->sysmsg_result);

cleanup:
	if (sa)
		FREE(sa, M_SONAME);
	iovec_free(&iov, aiov);
	return (error);
}

/*
 * kern_recvmsg() takes a handle to sa and control.  If the handle is non-
 * null, it returns a dynamically allocated struct sockaddr and an mbuf.
 * Don't forget to FREE() and m_free() these if they are returned.
 */
int
kern_recvmsg(int s, struct sockaddr **sa, struct uio *auio,
    struct mbuf **control, int *flags, int *res)
{
	struct thread *td = curthread;
	struct proc *p = td->td_proc;
	struct file *fp;
	int len, error;
	struct socket *so;
#ifdef KTRACE
	struct iovec *ktriov = NULL;
	struct uio ktruio;
#endif

	error = holdsock(p->p_fd, s, &fp);
	if (error)
		return (error);
	if (auio->uio_resid < 0) {
		error = EINVAL;
		goto done;
	}
#ifdef KTRACE
	if (KTRPOINT(td, KTR_GENIO)) {
		int iovlen = auio->uio_iovcnt * sizeof (struct iovec);

		MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
		bcopy(auio->uio_iov, ktriov, iovlen);
		ktruio = *auio;
	}
#endif
	len = auio->uio_resid;
	so = (struct socket *)fp->f_data;
	error = so_pru_soreceive(so, sa, auio, NULL, control, flags);
	if (error) {
		if (auio->uio_resid != len && (error == ERESTART ||
		    error == EINTR || error == EWOULDBLOCK))
			error = 0;
	}
#ifdef KTRACE
	if (ktriov != NULL) {
		if (error == 0) {
			ktruio.uio_iov = ktriov;
			ktruio.uio_resid = len - auio->uio_resid;
			ktrgenio(p->p_tracep, s, UIO_READ, &ktruio, error);
		}
		FREE(ktriov, M_TEMP);
	}
#endif
	if (error == 0)
		*res = len - auio->uio_resid;
done:
	fdrop(fp, td);
	return (error);
}

/*
 * recvfrom_args(int s, caddr_t buf, size_t len, int flags,
 *			caddr_t from, int *fromlenaddr)
 */
int
recvfrom(struct recvfrom_args *uap)
{
	struct thread *td = curthread;
	struct uio auio;
	struct iovec aiov;
	struct sockaddr *sa = NULL;
	int error, fromlen;

	if (uap->from && uap->fromlenaddr) {
		error = copyin(uap->fromlenaddr, &fromlen, sizeof(fromlen));
		if (error)
			return (error);
		if (fromlen < 0)
			return (EINVAL);
	} else {
		fromlen = 0;
	}
	aiov.iov_base = uap->buf;
	aiov.iov_len = uap->len;
	auio.uio_iov = &aiov;
	auio.uio_iovcnt = 1;
	auio.uio_offset = 0;
	auio.uio_resid = uap->len;
	auio.uio_segflg = UIO_USERSPACE;
	auio.uio_rw = UIO_READ;
	auio.uio_td = td;

	error = kern_recvmsg(uap->s, uap->from ? &sa : NULL, &auio, NULL,
	    &uap->flags, &uap->sysmsg_result);

	if (error == 0 && uap->from) {
		/* note: sa may still be NULL */
		if (sa) {
			fromlen = MIN(fromlen, sa->sa_len);
			error = copyout(sa, uap->from, fromlen);
		} else {
			fromlen = 0;
		}
		if (error == 0) {
			error = copyout(&fromlen, uap->fromlenaddr,
					sizeof(fromlen));
		}
	}
	if (sa)
		FREE(sa, M_SONAME);

	return (error);
}

/*
 * recvmsg_args(int s, struct msghdr *msg, int flags)
 */
int
recvmsg(struct recvmsg_args *uap)
{
	struct thread *td = curthread;
	struct msghdr msg;
	struct uio auio;
	struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
	struct mbuf *m, *control = NULL;
	struct sockaddr *sa = NULL;
	caddr_t ctlbuf;
	socklen_t *ufromlenp, *ucontrollenp;
	int error, fromlen, controllen, len, flags, *uflagsp;

	/*
	 * This copyin handles everything except the iovec.
	 */
	error = copyin(uap->msg, &msg, sizeof(msg));
	if (error)
		return (error);

	if (msg.msg_name && msg.msg_namelen < 0)
		return (EINVAL);
	if (msg.msg_control && msg.msg_controllen < 0)
		return (EINVAL);

	ufromlenp = (socklen_t *)((caddr_t)uap->msg + offsetof(struct msghdr,
	    msg_namelen));
	ucontrollenp = (socklen_t *)((caddr_t)uap->msg + offsetof(struct msghdr,
	    msg_controllen));
	uflagsp = (int *)((caddr_t)uap->msg + offsetof(struct msghdr,
	    msg_flags));

	/*
	 * Populate auio.
	 */
	error = iovec_copyin(msg.msg_iov, &iov, aiov, msg.msg_iovlen,
	    &auio.uio_resid);
	if (error)
		return (error);
	auio.uio_iov = iov;
	auio.uio_iovcnt = msg.msg_iovlen;
	auio.uio_offset = 0;
	auio.uio_segflg = UIO_USERSPACE;
	auio.uio_rw = UIO_READ;
	auio.uio_td = td;

	flags = msg.msg_flags;

	error = kern_recvmsg(uap->s, msg.msg_name ? &sa : NULL, &auio,
	    msg.msg_control ? &control : NULL, &flags, &uap->sysmsg_result);

	/*
	 * Conditionally copyout the name and populate the namelen field.
	 */
	if (error == 0 && msg.msg_name) {
		fromlen = MIN(msg.msg_namelen, sa->sa_len);
		error = copyout(sa, msg.msg_name, fromlen);
		if (error == 0)
			error = copyout(&fromlen, ufromlenp,
			    sizeof(*ufromlenp));
	}

	/*
	 * Copyout msg.msg_control and msg.msg_controllen.
	 */
	if (error == 0 && msg.msg_control) {
		len = msg.msg_controllen;
		m = control;
		ctlbuf = (caddr_t)msg.msg_control;

		while(m && len > 0) {
			unsigned int tocopy;

			if (len >= m->m_len) {
				tocopy = m->m_len;
			} else {
				msg.msg_flags |= MSG_CTRUNC;
				tocopy = len;
			}

			error = copyout(mtod(m, caddr_t), ctlbuf, tocopy);
			if (error)
				goto cleanup;

			ctlbuf += tocopy;
			len -= tocopy;
			m = m->m_next;
		}
		controllen = ctlbuf - (caddr_t)msg.msg_control;
		error = copyout(&controllen, ucontrollenp,
		    sizeof(*ucontrollenp));
	}

	if (error == 0)
		error = copyout(&flags, uflagsp, sizeof(*uflagsp));

cleanup:
	if (sa)
		FREE(sa, M_SONAME);
	iovec_free(&iov, aiov);
	if (control)
		m_freem(control);
	return (error);
}

/*
 * shutdown_args(int s, int how)
 */
int
kern_shutdown(int s, int how)
{
	struct thread *td = curthread;
	struct proc *p = td->td_proc;
	struct file *fp;
	int error;

	KKASSERT(p);
	error = holdsock(p->p_fd, s, &fp);
	if (error)
		return (error);
	error = soshutdown((struct socket *)fp->f_data, how);
	fdrop(fp, td);
	return(error);
}

int
shutdown(struct shutdown_args *uap)
{
	int error;

	error = kern_shutdown(uap->s, uap->how);

	return (error);
}

/*
 * If sopt->sopt_td == NULL, then sopt->sopt_val is treated as an
 * in kernel pointer instead of a userland pointer.  This allows us
 * to manipulate socket options in the emulation code.
 */
int
kern_setsockopt(int s, struct sockopt *sopt)
{
	struct thread *td = curthread;
	struct proc *p = td->td_proc;
	struct file *fp;
	int error;

	if (sopt->sopt_val == 0 && sopt->sopt_valsize != 0)
		return (EFAULT);
	if (sopt->sopt_valsize < 0)
		return (EINVAL);

	error = holdsock(p->p_fd, s, &fp);
	if (error)
		return (error);

	error = sosetopt((struct socket *)fp->f_data, sopt);
	fdrop(fp, td);
	return (error);
}

/*
 * setsockopt_args(int s, int level, int name, caddr_t val, int valsize)
 */
int
setsockopt(struct setsockopt_args *uap)
{
	struct thread *td = curthread;
	struct sockopt sopt;
	int error;

	sopt.sopt_dir = SOPT_SET;
	sopt.sopt_level = uap->level;
	sopt.sopt_name = uap->name;
	sopt.sopt_val = uap->val;
	sopt.sopt_valsize = uap->valsize;
	sopt.sopt_td = td;

	error = kern_setsockopt(uap->s, &sopt);
	return(error);
}

/*
 * If sopt->sopt_td == NULL, then sopt->sopt_val is treated as an
 * in kernel pointer instead of a userland pointer.  This allows us
 * to manipulate socket options in the emulation code.
 */
int
kern_getsockopt(int s, struct sockopt *sopt)
{
	struct thread *td = curthread;
	struct proc *p = td->td_proc;
	struct file *fp;
	int error;

	if (sopt->sopt_val == 0 && sopt->sopt_valsize != 0)
		return (EFAULT);
	if (sopt->sopt_valsize < 0)
		return (EINVAL);

	error = holdsock(p->p_fd, s, &fp);
	if (error)
		return (error);

	error = sogetopt((struct socket *)fp->f_data, sopt);
	fdrop(fp, td);
	return (error);
}

/*
 * getsockopt_Args(int s, int level, int name, caddr_t val, int *avalsize)
 */
int
getsockopt(struct getsockopt_args *uap)
{
	struct thread *td = curthread;
	struct	sockopt sopt;
	int	error, valsize;

	if (uap->val) {
		error = copyin(uap->avalsize, &valsize, sizeof(valsize));
		if (error)
			return (error);
		if (valsize < 0)
			return (EINVAL);
	} else {
		valsize = 0;
	}

	sopt.sopt_dir = SOPT_GET;
	sopt.sopt_level = uap->level;
	sopt.sopt_name = uap->name;
	sopt.sopt_val = uap->val;
	sopt.sopt_valsize = valsize;
	sopt.sopt_td = td;

	error = kern_getsockopt(uap->s, &sopt);
	if (error == 0) {
		valsize = sopt.sopt_valsize;
		error = copyout(&valsize, uap->avalsize, sizeof(valsize));
	}
	return (error);
}

/*
 * The second argument to kern_getsockname() is a handle to a struct sockaddr.
 * This allows kern_getsockname() to return a pointer to an allocated struct
 * sockaddr which must be freed later with FREE().  The caller must
 * initialize *name to NULL.
 */
int
kern_getsockname(int s, struct sockaddr **name, int *namelen)
{
	struct thread *td = curthread;
	struct proc *p = td->td_proc;
	struct file *fp;
	struct socket *so;
	struct sockaddr *sa = NULL;
	int error;

	error = holdsock(p->p_fd, s, &fp);
	if (error)
		return (error);
	if (*namelen < 0) {
		fdrop(fp, td);
		return (EINVAL);
	}
	so = (struct socket *)fp->f_data;
	error = so_pru_sockaddr(so, &sa);
	if (error == 0) {
		if (sa == 0) {
			*namelen = 0;
		} else {
			*namelen = MIN(*namelen, sa->sa_len);
			*name = sa;
		}
	}

	fdrop(fp, td);
	return (error);
}

/*
 * getsockname_args(int fdes, caddr_t asa, int *alen)
 *
 * Get socket name.
 */
int
getsockname(struct getsockname_args *uap)
{
	struct sockaddr *sa = NULL;
	int error, sa_len;

	error = copyin(uap->alen, &sa_len, sizeof(sa_len));
	if (error)
		return (error);

	error = kern_getsockname(uap->fdes, &sa, &sa_len);

	if (error == 0)
		error = copyout(sa, uap->asa, sa_len);
	if (error == 0)
		error = copyout(&sa_len, uap->alen, sizeof(*uap->alen));
	if (sa)
		FREE(sa, M_SONAME);
	return (error);
}

/*
 * The second argument to kern_getpeername() is a handle to a struct sockaddr.
 * This allows kern_getpeername() to return a pointer to an allocated struct
 * sockaddr which must be freed later with FREE().  The caller must
 * initialize *name to NULL.
 */
int
kern_getpeername(int s, struct sockaddr **name, int *namelen)
{
	struct thread *td = curthread;
	struct proc *p = td->td_proc;
	struct file *fp;
	struct socket *so;
	struct sockaddr *sa = NULL;
	int error;

	error = holdsock(p->p_fd, s, &fp);
	if (error)
		return (error);
	if (*namelen < 0) {
		fdrop(fp, td);
		return (EINVAL);
	}
	so = (struct socket *)fp->f_data;
	if ((so->so_state & (SS_ISCONNECTED|SS_ISCONFIRMING)) == 0) {
		fdrop(fp, td);
		return (ENOTCONN);
	}
	error = so_pru_peeraddr(so, &sa);
	if (error == 0) {
		if (sa == 0) {
			*namelen = 0;
		} else {
			*namelen = MIN(*namelen, sa->sa_len);
			*name = sa;
		}
	}

	fdrop(fp, td);
	return (error);
}

/*
 * getpeername_args(int fdes, caddr_t asa, int *alen)
 *
 * Get name of peer for connected socket.
 */
int
getpeername(struct getpeername_args *uap)
{
	struct sockaddr *sa = NULL;
	int error, sa_len;

	error = copyin(uap->alen, &sa_len, sizeof(sa_len));
	if (error)
		return (error);

	error = kern_getpeername(uap->fdes, &sa, &sa_len);

	if (error == 0)
		error = copyout(sa, uap->asa, sa_len);
	if (error == 0)
		error = copyout(&sa_len, uap->alen, sizeof(*uap->alen));
	if (sa)
		FREE(sa, M_SONAME);
	return (error);
}

int
getsockaddr(struct sockaddr **namp, caddr_t uaddr, size_t len)
{
	struct sockaddr *sa;
	int error;

	*namp = NULL;
	if (len > SOCK_MAXADDRLEN)
		return ENAMETOOLONG;
	if (len < offsetof(struct sockaddr, sa_data[0]))
		return EDOM;
	MALLOC(sa, struct sockaddr *, len, M_SONAME, M_WAITOK);
	error = copyin(uaddr, sa, len);
	if (error) {
		FREE(sa, M_SONAME);
	} else {
#if BYTE_ORDER != BIG_ENDIAN
		/*
		 * The bind(), connect(), and sendto() syscalls were not
		 * versioned for COMPAT_43.  Thus, this check must stay.
		 */
		if (sa->sa_family == 0 && sa->sa_len < AF_MAX)
			sa->sa_family = sa->sa_len;
#endif
		sa->sa_len = len;
		*namp = sa;
	}
	return error;
}

/*
 * holdsock() - load the struct file pointer associated
 * with a socket into *fpp.  If an error occurs, non-zero
 * will be returned and *fpp will be set to NULL.
 */
int
holdsock(fdp, fdes, fpp)
	struct filedesc *fdp;
	int fdes;
	struct file **fpp;
{
	struct file *fp = NULL;
	int error = 0;

	if ((unsigned)fdes >= fdp->fd_nfiles ||
	    (fp = fdp->fd_ofiles[fdes]) == NULL) {
		error = EBADF;
	} else if (fp->f_type != DTYPE_SOCKET) {
		error = ENOTSOCK;
		fp = NULL;
	} else {
		fhold(fp);
	}
	*fpp = fp;
	return(error);
}

/*
 * sendfile(2).
 * int sendfile(int fd, int s, off_t offset, size_t nbytes,
 *	 struct sf_hdtr *hdtr, off_t *sbytes, int flags)
 *
 * Send a file specified by 'fd' and starting at 'offset' to a socket
 * specified by 's'. Send only 'nbytes' of the file or until EOF if
 * nbytes == 0. Optionally add a header and/or trailer to the socket
 * output. If specified, write the total number of bytes sent into *sbytes.
 *
 * In FreeBSD kern/uipc_syscalls.c,v 1.103, a bug was fixed that caused
 * the headers to count against the remaining bytes to be sent from
 * the file descriptor.  We may wish to implement a compatibility syscall
 * in the future.
 */
int
sendfile(struct sendfile_args *uap)
{
	struct thread *td = curthread;
	struct proc *p = td->td_proc;
	struct file *fp;
	struct filedesc *fdp;
	struct vnode *vp = NULL;
	struct sf_hdtr hdtr;
	struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
	struct uio auio;
	off_t hdtr_size = 0, sbytes;
	int error, res;

	KKASSERT(p);
	fdp = p->p_fd;

	/*
	 * Do argument checking. Must be a regular file in, stream
	 * type and connected socket out, positive offset.
	 */
	fp = holdfp(fdp, uap->fd, FREAD);
	if (fp == NULL) {
		return (EBADF);
	}
	if (fp->f_type != DTYPE_VNODE) {
		fdrop(fp, td);
		return (EINVAL);
	}
	vp = (struct vnode *)fp->f_data;
	vref(vp);
	fdrop(fp, td);

	/*
	 * If specified, get the pointer to the sf_hdtr struct for
	 * any headers/trailers.
	 */
	if (uap->hdtr) {
		error = copyin(uap->hdtr, &hdtr, sizeof(hdtr));
		if (error)
			goto done;
		/*
		 * Send any headers.
		 */
		if (hdtr.headers) {
			error = iovec_copyin(hdtr.headers, &iov, aiov,
			    hdtr.hdr_cnt, &auio.uio_resid);
			if (error)
				goto done;
			auio.uio_iov = iov;
			auio.uio_iovcnt = hdtr.hdr_cnt;
			auio.uio_offset = 0;
			auio.uio_segflg = UIO_USERSPACE;
			auio.uio_rw = UIO_WRITE;
			auio.uio_td = td;

			error = kern_sendmsg(uap->s, NULL, &auio, NULL, 0,
			    &res);

			iovec_free(&iov, aiov);
			if (error)
				goto done;
			hdtr_size += res;
		}
	}

	error = kern_sendfile(vp, uap->s, uap->offset, uap->nbytes,
	    &sbytes, uap->flags);
	if (error)
		goto done;

	/*
	 * Send trailers. Wimp out and use writev(2).
	 */
	if (uap->hdtr != NULL && hdtr.trailers != NULL) {
		error = iovec_copyin(hdtr.trailers, &iov, aiov,
		    hdtr.trl_cnt, &auio.uio_resid);
		if (error)
			goto done;
		auio.uio_iov = iov;
		auio.uio_iovcnt = hdtr.trl_cnt;
		auio.uio_offset = 0;
		auio.uio_segflg = UIO_USERSPACE;
		auio.uio_rw = UIO_WRITE;
		auio.uio_td = td;

		error = kern_sendmsg(uap->s, NULL, &auio, NULL, 0, &res);

		iovec_free(&iov, aiov);
		if (error)
			goto done;
		hdtr_size += res;
	}

done:
	if (uap->sbytes != NULL) {
		sbytes += hdtr_size;
		copyout(&sbytes, uap->sbytes, sizeof(off_t));
	}
	if (vp)
		vrele(vp);
	return (error);
}

int
kern_sendfile(struct vnode *vp, int s, off_t offset, size_t nbytes,
    off_t *sbytes, int flags)
{
	struct thread *td = curthread;
	struct proc *p = td->td_proc;
	struct vm_object *obj;
	struct socket *so;
	struct file *fp;
	struct mbuf *m;
	struct sf_buf *sf;
	struct vm_page *pg;
	off_t off, xfsize;
	int error = 0;

	if (vp->v_type != VREG || VOP_GETVOBJECT(vp, &obj) != 0) {
		error = EINVAL;
		goto done;
	}
	error = holdsock(p->p_fd, s, &fp);
	if (error)
		goto done;
	so = (struct socket *)fp->f_data;
	if (so->so_type != SOCK_STREAM) {
		error = EINVAL;
		goto done;
	}
	if ((so->so_state & SS_ISCONNECTED) == 0) {
		error = ENOTCONN;
		goto done;
	}
	if (offset < 0) {
		error = EINVAL;
		goto done;
	}

	*sbytes = 0;
	/*
	 * Protect against multiple writers to the socket.
	 */
	(void) sblock(&so->so_snd, M_WAITOK);

	/*
	 * Loop through the pages in the file, starting with the requested
	 * offset. Get a file page (do I/O if necessary), map the file page
	 * into an sf_buf, attach an mbuf header to the sf_buf, and queue
	 * it on the socket.
	 */
	for (off = offset; ; off += xfsize, *sbytes += xfsize) {
		vm_pindex_t pindex;
		vm_offset_t pgoff;

		pindex = OFF_TO_IDX(off);
retry_lookup:
		/*
		 * Calculate the amount to transfer. Not to exceed a page,
		 * the EOF, or the passed in nbytes.
		 */
		xfsize = obj->un_pager.vnp.vnp_size - off;
		if (xfsize > PAGE_SIZE)
			xfsize = PAGE_SIZE;
		pgoff = (vm_offset_t)(off & PAGE_MASK);
		if (PAGE_SIZE - pgoff < xfsize)
			xfsize = PAGE_SIZE - pgoff;
		if (nbytes && xfsize > (nbytes - *sbytes))
			xfsize = nbytes - *sbytes;
		if (xfsize <= 0)
			break;
		/*
		 * Optimize the non-blocking case by looking at the socket space
		 * before going to the extra work of constituting the sf_buf.
		 */
		if ((so->so_state & SS_NBIO) && sbspace(&so->so_snd) <= 0) {
			if (so->so_state & SS_CANTSENDMORE)
				error = EPIPE;
			else
				error = EAGAIN;
			sbunlock(&so->so_snd);
			goto done;
		}
		/*
		 * Attempt to look up the page.
		 *
		 *	Allocate if not found
		 *
		 *	Wait and loop if busy.
		 */
		pg = vm_page_lookup(obj, pindex);

		if (pg == NULL) {
			pg = vm_page_alloc(obj, pindex, VM_ALLOC_NORMAL);
			if (pg == NULL) {
				VM_WAIT;
				goto retry_lookup;
			}
			vm_page_wakeup(pg);
		} else if (vm_page_sleep_busy(pg, TRUE, "sfpbsy")) {
			goto retry_lookup;
		}

		/*
		 * Wire the page so it does not get ripped out from under
		 * us.
		 */

		vm_page_wire(pg);

		/*
		 * If page is not valid for what we need, initiate I/O
		 */

		if (!pg->valid || !vm_page_is_valid(pg, pgoff, xfsize)) {
			struct uio auio;
			struct iovec aiov;
			int bsize;

			/*
			 * Ensure that our page is still around when the I/O
			 * completes.
			 */
			vm_page_io_start(pg);

			/*
			 * Get the page from backing store.
			 */
			bsize = vp->v_mount->mnt_stat.f_iosize;
			auio.uio_iov = &aiov;
			auio.uio_iovcnt = 1;
			aiov.iov_base = 0;
			aiov.iov_len = MAXBSIZE;
			auio.uio_resid = MAXBSIZE;
			auio.uio_offset = trunc_page(off);
			auio.uio_segflg = UIO_NOCOPY;
			auio.uio_rw = UIO_READ;
			auio.uio_td = td;
			vn_lock(vp, NULL, LK_SHARED | LK_NOPAUSE | LK_RETRY, td);
			error = VOP_READ(vp, &auio,
				    IO_VMIO | ((MAXBSIZE / bsize) << 16),
				    p->p_ucred);
			VOP_UNLOCK(vp, NULL, 0, td);
			vm_page_flag_clear(pg, PG_ZERO);
			vm_page_io_finish(pg);
			if (error) {
				vm_page_unwire(pg, 0);
				/*
				 * See if anyone else might know about this page.
				 * If not and it is not valid, then free it.
				 */
				if (pg->wire_count == 0 && pg->valid == 0 &&
				    pg->busy == 0 && !(pg->flags & PG_BUSY) &&
				    pg->hold_count == 0) {
					vm_page_busy(pg);
					vm_page_free(pg);
				}
				sbunlock(&so->so_snd);
				goto done;
			}
		}


		/*
		 * Get a sendfile buf. We usually wait as long as necessary,
		 * but this wait can be interrupted.
		 */
		if ((sf = sf_buf_alloc(pg)) == NULL) {
			s = splvm();
			vm_page_unwire(pg, 0);
			if (pg->wire_count == 0 && pg->object == NULL)
				vm_page_free(pg);
			splx(s);
			sbunlock(&so->so_snd);
			error = EINTR;
			goto done;
		}

		/*
		 * Get an mbuf header and set it up as having external storage.
		 */
		MGETHDR(m, M_WAIT, MT_DATA);
		if (m == NULL) {
			error = ENOBUFS;
			sf_buf_free((void *)sf->kva, PAGE_SIZE);
			sbunlock(&so->so_snd);
			goto done;
		}
		m->m_ext.ext_free = sf_buf_free;
		m->m_ext.ext_ref = sf_buf_ref;
		m->m_ext.ext_buf = (void *)sf->kva;
		m->m_ext.ext_size = PAGE_SIZE;
		m->m_data = (char *) sf->kva + pgoff;
		m->m_flags |= M_EXT;
		m->m_pkthdr.len = m->m_len = xfsize;
		/*
		 * Add the buffer to the socket buffer chain.
		 */
		s = splnet();
retry_space:
		/*
		 * Make sure that the socket is still able to take more data.
		 * CANTSENDMORE being true usually means that the connection
		 * was closed. so_error is true when an error was sensed after
		 * a previous send.
		 * The state is checked after the page mapping and buffer
		 * allocation above since those operations may block and make
		 * any socket checks stale. From this point forward, nothing
		 * blocks before the pru_send (or more accurately, any blocking
		 * results in a loop back to here to re-check).
		 */
		if ((so->so_state & SS_CANTSENDMORE) || so->so_error) {
			if (so->so_state & SS_CANTSENDMORE) {
				error = EPIPE;
			} else {
				error = so->so_error;
				so->so_error = 0;
			}
			m_freem(m);
			sbunlock(&so->so_snd);
			splx(s);
			goto done;
		}
		/*
		 * Wait for socket space to become available. We do this just
		 * after checking the connection state above in order to avoid
		 * a race condition with sbwait().
		 */
		if (sbspace(&so->so_snd) < so->so_snd.sb_lowat) {
			if (so->so_state & SS_NBIO) {
				m_freem(m);
				sbunlock(&so->so_snd);
				splx(s);
				error = EAGAIN;
				goto done;
			}
			error = sbwait(&so->so_snd);
			/*
			 * An error from sbwait usually indicates that we've
			 * been interrupted by a signal. If we've sent anything
			 * then return bytes sent, otherwise return the error.
			 */
			if (error) {
				m_freem(m);
				sbunlock(&so->so_snd);
				splx(s);
				goto done;
			}
			goto retry_space;
		}
		error = so_pru_send(so, 0, m, NULL, NULL, td);
		splx(s);
		if (error) {
			sbunlock(&so->so_snd);
			goto done;
		}
	}
	sbunlock(&so->so_snd);

done:
	if (fp)
		fdrop(fp, td);
	return (error);
}