opensolaris_uio.c revision 302408 
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
27/*        All Rights Reserved   */
28
29/*
30 * University Copyright- Copyright (c) 1982, 1986, 1988
31 * The Regents of the University of California
32 * All Rights Reserved
33 *
34 * University Acknowledgment- Portions of this document are derived from
35 * software developed by the University of California, Berkeley, and its
36 * contributors.
37 */
38
39/*
40 * $FreeBSD: stable/11/sys/cddl/compat/opensolaris/kern/opensolaris_uio.c 209962 2010-07-12 23:49:04Z mm $
41 */
42
43#include <sys/types.h>
44#include <sys/uio.h>
45
46/*
47 * same as uiomove() but doesn't modify uio structure.
48 * return in cbytes how many bytes were copied.
49 */
50int
51uiocopy(void *p, size_t n, enum uio_rw rw, struct uio *uio, size_t *cbytes)
52{
53	struct iovec *iov;
54	ulong_t cnt;
55	int error, iovcnt;
56
57	iovcnt = uio->uio_iovcnt;
58	*cbytes = 0;
59
60	for (iov = uio->uio_iov; n > 0 && iovcnt > 0; iov++, iovcnt--) {
61		cnt = MIN(iov->iov_len, n);
62		if (cnt == 0)
63			continue;
64
65		switch (uio->uio_segflg) {
66		case UIO_USERSPACE:
67			if (rw == UIO_READ)
68				error = copyout(p, iov->iov_base, cnt);
69			else
70				error = copyin(iov->iov_base, p, cnt);
71			if (error)
72				return (error);
73			break;
74		case UIO_SYSSPACE:
75			if (uio->uio_rw == UIO_READ)
76				bcopy(p, iov->iov_base, cnt);
77			else
78				bcopy(iov->iov_base, p, cnt);
79			break;
80		}
81
82		p = (caddr_t)p + cnt;
83		n -= cnt;
84		*cbytes += cnt;
85	}
86	return (0);
87}
88
89/*
90 * Drop the next n chars out of *uiop.
91 */
92void
93uioskip(uio_t *uiop, size_t n)
94{
95	if (n > uiop->uio_resid)
96		return;
97	while (n != 0) {
98		register iovec_t	*iovp = uiop->uio_iov;
99		register size_t		niovb = MIN(iovp->iov_len, n);
100
101		if (niovb == 0) {
102			uiop->uio_iov++;
103			uiop->uio_iovcnt--;
104			continue;
105		}
106		iovp->iov_base += niovb;
107		uiop->uio_loffset += niovb;
108		iovp->iov_len -= niovb;
109		uiop->uio_resid -= niovb;
110		n -= niovb;
111	}
112}
113