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  * $FreeBSD$
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  */
50 int
51 uiocopy(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  */
92 void
93 uioskip(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