move.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* University Copyright- Copyright (c) 1982, 1986, 1988
* The Regents of the University of California
* All Rights Reserved
*
* University Acknowledgment- Portions of this document are derived from
* software developed by the University of California, Berkeley, and its
* contributors.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/types.h>
#include <sys/sysmacros.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <sys/errno.h>
/*
* Move "n" bytes at byte address "p"; "rw" indicates the direction
* of the move, and the I/O parameters are provided in "uio", which is
* update to reflect the data which was moved. Returns 0 on success or
* a non-zero errno on failure.
*/
int
uiomove(void *p, size_t n, enum uio_rw rw, struct uio *uio)
{
struct iovec *iov;
ulong_t cnt;
int error;
while (n && uio->uio_resid) {
iov = uio->uio_iov;
cnt = MIN(iov->iov_len, n);
if (cnt == 0l) {
uio->uio_iov++;
uio->uio_iovcnt--;
continue;
}
switch (uio->uio_segflg) {
case UIO_USERSPACE:
case UIO_USERISPACE:
if (rw == UIO_READ) {
error = xcopyout_nta(p, iov->iov_base, cnt,
(uio->uio_extflg & UIO_COPY_CACHED));
} else {
error = xcopyin_nta(iov->iov_base, p, cnt,
(uio->uio_extflg & UIO_COPY_CACHED));
}
if (error)
return (error);
break;
case UIO_SYSSPACE:
if (rw == UIO_READ)
error = kcopy_nta(p, iov->iov_base, cnt,
(uio->uio_extflg & UIO_COPY_CACHED));
else
error = kcopy_nta(iov->iov_base, p, cnt,
(uio->uio_extflg & UIO_COPY_CACHED));
if (error)
return (error);
break;
}
iov->iov_base += cnt;
iov->iov_len -= cnt;
uio->uio_resid -= cnt;
uio->uio_loffset += cnt;
p = (caddr_t)p + cnt;
n -= cnt;
}
return (0);
}
/*
* transfer a character value into the address space
* delineated by a uio and update fields within the
* uio for next character. Return 0 for success, EFAULT
* for error.
*/
int
ureadc(int val, struct uio *uiop)
{
struct iovec *iovp;
unsigned char c;
/*
* first determine if uio is valid. uiop should be
* non-NULL and the resid count > 0.
*/
if (!(uiop && uiop->uio_resid > 0))
return (EFAULT);
/*
* scan through iovecs until one is found that is non-empty.
* Return EFAULT if none found.
*/
while (uiop->uio_iovcnt > 0) {
iovp = uiop->uio_iov;
if (iovp->iov_len <= 0) {
uiop->uio_iovcnt--;
uiop->uio_iov++;
} else
break;
}
if (uiop->uio_iovcnt <= 0)
return (EFAULT);
/*
* Transfer character to uio space.
*/
c = (unsigned char) (val & 0xFF);
switch (uiop->uio_segflg) {
case UIO_USERISPACE:
case UIO_USERSPACE:
if (copyout(&c, iovp->iov_base, sizeof (unsigned char)))
return (EFAULT);
break;
case UIO_SYSSPACE: /* can do direct copy since kernel-kernel */
*iovp->iov_base = c;
break;
default:
return (EFAULT); /* invalid segflg value */
}
/*
* bump up/down iovec and uio members to reflect transfer.
*/
iovp->iov_base++;
iovp->iov_len--;
uiop->uio_resid--;
uiop->uio_loffset++;
return (0); /* success */
}
/*
* return a character value from the address space
* delineated by a uio and update fields within the
* uio for next character. Return the character for success,
* -1 for error.
*/
int
uwritec(struct uio *uiop)
{
struct iovec *iovp;
unsigned char c;
/*
* verify we were passed a valid uio structure.
* (1) non-NULL uiop, (2) positive resid count
* (3) there is an iovec with positive length
*/
if (!(uiop && uiop->uio_resid > 0))
return (-1);
while (uiop->uio_iovcnt > 0) {
iovp = uiop->uio_iov;
if (iovp->iov_len <= 0) {
uiop->uio_iovcnt--;
uiop->uio_iov++;
} else
break;
}
if (uiop->uio_iovcnt <= 0)
return (-1);
/*
* Get the character from the uio address space.
*/
switch (uiop->uio_segflg) {
case UIO_USERISPACE:
case UIO_USERSPACE:
if (copyin(iovp->iov_base, &c, sizeof (unsigned char)))
return (-1);
break;
case UIO_SYSSPACE:
c = *iovp->iov_base;
break;
default:
return (-1); /* invalid segflg */
}
/*
* Adjust fields of iovec and uio appropriately.
*/
iovp->iov_base++;
iovp->iov_len--;
uiop->uio_resid--;
uiop->uio_loffset++;
return ((int)c & 0xFF); /* success */
}
/*
* Drop the next n chars out of *uiop.
*/
void
uioskip(uio_t *uiop, size_t n)
{
if (n > uiop->uio_resid)
return;
while (n != 0) {
register iovec_t *iovp = uiop->uio_iov;
register size_t niovb = MIN(iovp->iov_len, n);
if (niovb == 0) {
uiop->uio_iov++;
uiop->uio_iovcnt--;
continue;
}
iovp->iov_base += niovb;
uiop->uio_loffset += niovb;
iovp->iov_len -= niovb;
uiop->uio_resid -= niovb;
n -= niovb;
}
}
/*
* Dup the suio into the duio and diovec of size diov_cnt. If diov
* is too small to dup suio then an error will be returned, else 0.
*/
int
uiodup(uio_t *suio, uio_t *duio, iovec_t *diov, int diov_cnt)
{
int ix;
iovec_t *siov = suio->uio_iov;
*duio = *suio;
for (ix = 0; ix < suio->uio_iovcnt; ix++) {
diov[ix] = siov[ix];
if (ix >= diov_cnt)
return (1);
}
duio->uio_iov = diov;
return (0);
}