4.3BSD-Reno/src/sys/sys/uio.h

/*
 * Copyright (c) 1982, 1986 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution is only permitted until one year after the first shipment
 * of 4.4BSD by the Regents.  Otherwise, redistribution and use in source and
 * binary forms are permitted provided that: (1) source distributions retain
 * this entire copyright notice and comment, and (2) distributions including
 * binaries display the following acknowledgement:  This product includes
 * software developed by the University of California, Berkeley and its
 * contributors'' in the documentation or other materials provided with the
 * distribution and in all advertising materials mentioning features or use
 * of this software.  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 AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *	@(#)uio.h	7.5 (Berkeley) 6/28/90
 */

#ifndef _UIO_
#define	_UIO_

struct iovec {
	caddr_t	iov_base;
	int	iov_len;
};

enum	uio_rw { UIO_READ, UIO_WRITE };

/*
 * Segment flag values.
 */
enum	uio_seg {
	UIO_USERSPACE,		/* from user data space */
	UIO_SYSSPACE,		/* from system space */
	UIO_USERISPACE		/* from user I space */
};

struct uio {
	struct	iovec *uio_iov;
	int	uio_iovcnt;
	off_t	uio_offset;
	int	uio_resid;
	enum	uio_seg uio_segflg;
	enum	uio_rw uio_rw;
};

 /*
  * Limits
  */
#define UIO_MAXIOV	1024		/* max 1K of iov's */
#define UIO_SMALLIOV	8		/* 8 on stack, else malloc */

#endif /* !_UIO_ */