sys_generic.c

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/*	$NetBSD: sys_generic.c,v 1.24 1996/03/29 00:25:32 cgd Exp $	*/

/*
 * Copyright (c) 1982, 1986, 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, 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 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.
 *
 *	@(#)sys_generic.c	8.5 (Berkeley) 1/21/94
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/filedesc.h>
#include <sys/ioctl.h>
#include <sys/file.h>
#include <sys/proc.h>
#include <sys/socketvar.h>
#include <sys/signalvar.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/stat.h>
#include <sys/malloc.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif

#include <sys/mount.h>
#include <sys/syscallargs.h>

int selscan __P((struct proc *, fd_set *, fd_set *, int, register_t *));
int seltrue __P((dev_t, int, struct proc *));

/*
 * Read system call.
 */
/* ARGSUSED */
int
sys_read(p, v, retval)
	struct proc *p;
	void *v;
	register_t *retval;
{
	register struct sys_read_args /* {
		syscallarg(int) fd;
		syscallarg(char *) buf;
		syscallarg(u_int) nbyte;
	} */ *uap = v;
	register struct file *fp;
	register struct filedesc *fdp = p->p_fd;
	struct uio auio;
	struct iovec aiov;
	long cnt, error = 0;
#ifdef KTRACE
	struct iovec ktriov;
#endif

	if (((u_int)SCARG(uap, fd)) >= fdp->fd_nfiles ||
	    (fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL ||
	    (fp->f_flag & FREAD) == 0)
		return (EBADF);
	aiov.iov_base = (caddr_t)SCARG(uap, buf);
	aiov.iov_len = SCARG(uap, nbyte);
	auio.uio_iov = &aiov;
	auio.uio_iovcnt = 1;
	auio.uio_resid = SCARG(uap, nbyte);
	auio.uio_rw = UIO_READ;
	auio.uio_segflg = UIO_USERSPACE;
	auio.uio_procp = p;
	if (auio.uio_resid < 0)
		return EINVAL;
#ifdef KTRACE
	/*
	 * if tracing, save a copy of iovec
	 */
	if (KTRPOINT(p, KTR_GENIO))
		ktriov = aiov;
#endif
	cnt = SCARG(uap, nbyte);
	error = (*fp->f_ops->fo_read)(fp, &auio, fp->f_cred);
	if (error)
		if (auio.uio_resid != cnt && (error == ERESTART ||
		    error == EINTR || error == EWOULDBLOCK))
			error = 0;
	cnt -= auio.uio_resid;
#ifdef KTRACE
	if (KTRPOINT(p, KTR_GENIO) && error == 0)
		ktrgenio(p->p_tracep, SCARG(uap, fd), UIO_READ, &ktriov,
		    cnt, error);
#endif
	*retval = cnt;
	return (error);
}

/*
 * Scatter read system call.
 */
int
sys_readv(p, v, retval)
	struct proc *p;
	void *v;
	register_t *retval;
{
	register struct sys_readv_args /* {
		syscallarg(int) fd;
		syscallarg(struct iovec *) iovp;
		syscallarg(u_int) iovcnt;
	} */ *uap = v;
	register struct file *fp;
	register struct filedesc *fdp = p->p_fd;
	struct uio auio;
	register struct iovec *iov;
	struct iovec *needfree;
	struct iovec aiov[UIO_SMALLIOV];
	long i, cnt, error = 0;
	u_int iovlen;
#ifdef KTRACE
	struct iovec *ktriov = NULL;
#endif

	if (((u_int)SCARG(uap, fd)) >= fdp->fd_nfiles ||
	    (fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL ||
	    (fp->f_flag & FREAD) == 0)
		return (EBADF);
	/* note: can't use iovlen until iovcnt is validated */
	iovlen = SCARG(uap, iovcnt) * sizeof (struct iovec);
	if (SCARG(uap, iovcnt) > UIO_SMALLIOV) {
		if (SCARG(uap, iovcnt) > UIO_MAXIOV)
			return (EINVAL);
		MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK);
		needfree = iov;
	} else {
		iov = aiov;
		needfree = NULL;
	}
	auio.uio_iov = iov;
	auio.uio_iovcnt = SCARG(uap, iovcnt);
	auio.uio_rw = UIO_READ;
	auio.uio_segflg = UIO_USERSPACE;
	auio.uio_procp = p;
	error = copyin((caddr_t)SCARG(uap, iovp), (caddr_t)iov, iovlen);
	if (error)
		goto done;
	auio.uio_resid = 0;
	for (i = 0; i < SCARG(uap, iovcnt); i++) {
#if 0
		/* Cannot happen iov_len is unsigned */
		if (iov->iov_len < 0) {
			error = EINVAL;
			goto done;
		}
#endif
		auio.uio_resid += iov->iov_len;
		if (auio.uio_resid < 0) {
			error = EINVAL;
			goto done;
		}
		iov++;
	}
#ifdef KTRACE
	/*
	 * if tracing, save a copy of iovec
	 */
	if (KTRPOINT(p, KTR_GENIO))  {
		MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
		bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen);
	}
#endif
	cnt = auio.uio_resid;
	error = (*fp->f_ops->fo_read)(fp, &auio, fp->f_cred);
	if (error)
		if (auio.uio_resid != cnt && (error == ERESTART ||
		    error == EINTR || error == EWOULDBLOCK))
			error = 0;
	cnt -= auio.uio_resid;
#ifdef KTRACE
	if (ktriov != NULL) {
		if (error == 0)
			ktrgenio(p->p_tracep, SCARG(uap, fd), UIO_READ, ktriov,
			    cnt, error);
		FREE(ktriov, M_TEMP);
	}
#endif
	*retval = cnt;
done:
	if (needfree)
		FREE(needfree, M_IOV);
	return (error);
}

/*
 * Write system call
 */
int
sys_write(p, v, retval)
	struct proc *p;
	void *v;
	register_t *retval;
{
	register struct sys_write_args /* {
		syscallarg(int) fd;
		syscallarg(char *) buf;
		syscallarg(u_int) nbyte;
	} */ *uap = v;
	register struct file *fp;
	register struct filedesc *fdp = p->p_fd;
	struct uio auio;
	struct iovec aiov;
	long cnt, error = 0;
#ifdef KTRACE
	struct iovec ktriov;
#endif

	if (((u_int)SCARG(uap, fd)) >= fdp->fd_nfiles ||
	    (fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL ||
	    (fp->f_flag & FWRITE) == 0)
		return (EBADF);
	aiov.iov_base = (caddr_t)SCARG(uap, buf);
	aiov.iov_len = SCARG(uap, nbyte);
	auio.uio_iov = &aiov;
	auio.uio_iovcnt = 1;
	auio.uio_resid = SCARG(uap, nbyte);
	auio.uio_rw = UIO_WRITE;
	auio.uio_segflg = UIO_USERSPACE;
	auio.uio_procp = p;
	if (auio.uio_resid < 0)
		return EINVAL;
#ifdef KTRACE
	/*
	 * if tracing, save a copy of iovec
	 */
	if (KTRPOINT(p, KTR_GENIO))
		ktriov = aiov;
#endif
	cnt = SCARG(uap, nbyte);
	error = (*fp->f_ops->fo_write)(fp, &auio, fp->f_cred);
	if (error) {
		if (auio.uio_resid != cnt && (error == ERESTART ||
		    error == EINTR || error == EWOULDBLOCK))
			error = 0;
		if (error == EPIPE)
			psignal(p, SIGPIPE);
	}
	cnt -= auio.uio_resid;
#ifdef KTRACE
	if (KTRPOINT(p, KTR_GENIO) && error == 0)
		ktrgenio(p->p_tracep, SCARG(uap, fd), UIO_WRITE,
		    &ktriov, cnt, error);
#endif
	*retval = cnt;
	return (error);
}

/*
 * Gather write system call
 */
int
sys_writev(p, v, retval)
	struct proc *p;
	void *v;
	register_t *retval;
{
	register struct sys_writev_args /* {
		syscallarg(int) fd;
		syscallarg(struct iovec *) iovp;
		syscallarg(u_int) iovcnt;
	} */ *uap = v;
	register struct file *fp;
	register struct filedesc *fdp = p->p_fd;
	struct uio auio;
	register struct iovec *iov;
	struct iovec *needfree;
	struct iovec aiov[UIO_SMALLIOV];
	long i, cnt, error = 0;
	u_int iovlen;
#ifdef KTRACE
	struct iovec *ktriov = NULL;
#endif

	if (((u_int)SCARG(uap, fd)) >= fdp->fd_nfiles ||
	    (fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL ||
	    (fp->f_flag & FWRITE) == 0)
		return (EBADF);
	/* note: can't use iovlen until iovcnt is validated */
	iovlen = SCARG(uap, iovcnt) * sizeof (struct iovec);
	if (SCARG(uap, iovcnt) > UIO_SMALLIOV) {
		if (SCARG(uap, iovcnt) > UIO_MAXIOV)
			return (EINVAL);
		MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK);
		needfree = iov;
	} else {
		iov = aiov;
		needfree = NULL;
	}
	auio.uio_iov = iov;
	auio.uio_iovcnt = SCARG(uap, iovcnt);
	auio.uio_rw = UIO_WRITE;
	auio.uio_segflg = UIO_USERSPACE;
	auio.uio_procp = p;
	error = copyin((caddr_t)SCARG(uap, iovp), (caddr_t)iov, iovlen);
	if (error)
		goto done;
	auio.uio_resid = 0;
	for (i = 0; i < SCARG(uap, iovcnt); i++) {
#if 0
		/* Cannot happen iov_len is unsigned */
		if (iov->iov_len < 0) {
			error = EINVAL;
			goto done;
		}
#endif
		auio.uio_resid += iov->iov_len;
		if (auio.uio_resid < 0) {
			error = EINVAL;
			goto done;
		}
		iov++;
	}
#ifdef KTRACE
	/*
	 * if tracing, save a copy of iovec
	 */
	if (KTRPOINT(p, KTR_GENIO))  {
		MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
		bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen);
	}
#endif
	cnt = auio.uio_resid;
	error = (*fp->f_ops->fo_write)(fp, &auio, fp->f_cred);
	if (error) {
		if (auio.uio_resid != cnt && (error == ERESTART ||