[unix-history] / usr / src / sys / sys / uio.h

/*
* Copyright (c) 1982, 1986 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley.  The name of the
* University may not 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       7.4 (Berkeley) %G%
*/

#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_ */