xref: /386bsd/usr/src/kernel/include/sys/uio.h (revision a2142627)
1 /*
2  * Copyright (c) 1982, 1986 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	$Id$
34  */
35 
36 #ifndef _UIO_H_
37 #define	_UIO_H_
38 
39 struct iovec {
40 	caddr_t	iov_base;
41 	int	iov_len;
42 };
43 
44 enum	uio_rw { UIO_READ, UIO_WRITE };
45 
46 /*
47  * Segment flag values.
48  */
49 enum	uio_seg {
50 	UIO_USERSPACE,		/* from user data space */
51 	UIO_SYSSPACE,		/* from system space */
52 	/* UIO_USERISPACE	/* from user I space */
53 };
54 
55 struct uio {
56 	struct	iovec *uio_iov;
57 	int	uio_iovcnt;
58 	off_t	uio_offset;
59 	int	uio_resid;
60 	enum	uio_seg uio_segflg;
61 	enum	uio_rw uio_rw;
62 	struct	proc *uio_procp;
63 };
64 
65  /*
66   * Limits
67   */
68 #define UIO_MAXIOV	1024		/* max 1K of iov's */
69 #define UIO_SMALLIOV	8		/* 8 on stack, else malloc */
70 
71 #ifndef	KERNEL
72 
73 #include <sys/cdefs.h>
74 
75 __BEGIN_DECLS
76 int	readv __P((int, const struct iovec *, int));
77 int	writev __P((int, const struct iovec *, int));
78 __END_DECLS
79 
80 #else
81 struct iovec *uio_advance(struct uio *uio, struct iovec *iov, int cnt);
82 int uiomove(caddr_t cp, int len, struct uio *uio);
83 
84 /*
85  * Advance a uio and its iov by cnt bytes, returning next iov.
86  */
87 extern inline struct iovec *
88 uio_advance(struct uio *uio, struct iovec *iov, int cnt) {
89 
90 	/* consume an iov, possibly fetching the next one */
91 	iov->iov_base += cnt;
92 	iov->iov_len -= cnt;
93 	if (iov->iov_len == 0) {
94 		iov = ++uio->uio_iov;
95 		uio->uio_iovcnt--;
96 	}
97 
98 	uio->uio_resid -= cnt;
99 	uio->uio_offset += cnt;
100 
101 	return (iov);
102 }
103 
104 #define	uio_base(uio)	(uio)->uio_iov->iov_base
105 #define	uio_len(uio)	(uio)->uio_iov->iov_len
106 
107 #endif	/* !KERNEL */
108 
109 #endif /* !_UIO_H_ */
110