source: rtems/cpukit/libnetworking/sys/uio.h @ ee613aa

/*
 * Copyright (c) 1982, 1986, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)uio.h       8.5 (Berkeley) 2/22/94
 * $FreeBSD: src/sys/sys/uio.h,v 1.40 2006/11/29 19:08:45 alfred Exp $
 */

/*
 * $Id$
 */

#ifndef _SYS_UIO_H_
#define _SYS_UIO_H_

#include <sys/cdefs.h>
#include <sys/types.h>

/*
 *  POSIX compliant iovec definition
 */
struct iovec {
  void    *iov_base;  /* pointer to data to be written */
  size_t   iov_len;   /* length of this data block */
};

#if __BSD_VISIBLE
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_NOCOPY              /* don't copy, already in object */
};
#endif

#ifdef _KERNEL

struct uio {
        struct  iovec *uio_iov;         /* scatter/gather list */
        int     uio_iovcnt;             /* length of scatter/gather list */
        off_t   uio_offset;             /* offset in target object */
        ssize_t uio_resid;              /* remaining bytes to process */
        enum    uio_seg uio_segflg;     /* address space */
        enum    uio_rw uio_rw;          /* operation */
#if !defined(__rtems__)
        struct  thread *uio_td;         /* owner */
#else
        struct  proc *uio_procp;
#endif /* !__rtems__ */
};

/*
 * Limits
 *
 * N.B.: UIO_MAXIOV must be no less than IOV_MAX from <sys/syslimits.h>
 * which in turn must be no less than _XOPEN_IOV_MAX from <limits.h>.  If
 * we ever make this tunable (probably pointless), then IOV_MAX should be
 * removed from <sys/syslimits.h> and applications would be expected to use
 * sysconf(3) to find out the correct value, or else assume the worst
 * (_XOPEN_IOV_MAX).  Perhaps UIO_MAXIOV should be simply defined as
 * IOV_MAX.
 */
#define UIO_MAXIOV      1024            /* max 1K of iov's */

int     uiomove(void *cp, int n, struct uio *uio);

#else /* !_KERNEL */

__BEGIN_DECLS
ssize_t readv(int, const struct iovec *, int);
ssize_t writev(int, const struct iovec *, int);
__END_DECLS

#endif /* _KERNEL */

#endif /* !_SYS_UIO_H_ */