'\" te
.\" Copyright (c) 2004, Sun Microsystems, Inc.  All Rights Reserved
.\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
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.TH MCOPYOUT 9F "Jun 9, 2004"
.SH NAME
mcopyout \- Convert an M_IOCTL or M_IOCDATA message to an M_COPYOUT
.SH SYNOPSIS
.nf
#include <sys/stream.h>
#include <sys/strsun.h>



\fBvoid\fR \fBmcopyout\fR(\fBmblk_t *\fR\fImp\fR, \fBvoid *\fR\fIprivate\fR, \fBsize_t\fR \fIsize\fR, \fBvoid *\fR\fIuseraddr\fR,
      \fBmblk_t *\fR\fIdp\fR);
.fi

.SH INTERFACE LEVEL
illumos DDI specific (illumos DDI).
.SH PARAMETERS
.ne 2
.na
\fB\fImp\fR\fR
.ad
.RS 12n
M_IOCTL or M_IOCDATA message.
.RE

.sp
.ne 2
.na
\fB\fIprivate\fR\fR
.ad
.RS 12n
Value to set the cq_private field of the \fBcopyreq\fR(9S) to.
.RE

.sp
.ne 2
.na
\fB\fIsize\fR\fR
.ad
.RS 12n
Value to set the cq_size field of the \fBcopyreq\fR(9S) to.
.RE

.sp
.ne 2
.na
\fB\fIuseraddr\fR\fR
.ad
.RS 12n
Optionally, the value to set the cq_addr field of the \fBcopyreq\fR(9S) to.
.RE

.sp
.ne 2
.na
\fB\fIdp\fR\fR
.ad
.RS 12n
Optionally, the payload to copy out.
.RE

.SH DESCRIPTION
The \fBmcopyout()\fR function converts an M_IOCTL or M_IOCDATA message into an
M_COPYOUT message using the supplied arguments.
.sp
.LP
To convert the message, \fBmcopyout()\fR changes the message type to M_COPYOUT,
and its payload from a \fBiocblk\fR(9S) to a \fBcopyreq\fR(9S). Since the
\fBiocblk\fR(9S) and \fBcopyreq\fR(9S) are designed to overlay one another, the
only fields which must be updated are \fBcq_private\fR, \fBcq_size\fR, and
\fBcq_addr\fR, which are set to the supplied values. If \fIuseraddr\fR is
passed as NULL, the M_IOCTL must be transparent and \fBcq_addr\fR is assigned
the pointer-sized quantity found at \fBmp->b_cont->b_rptr\fR.
.sp
.LP
If \fIdp\fR is not NULL, any trailing message blocks associated with \fImp\fR
are freed, \fBmp->b_cont\fR is reset to \fIdp\fR and \fBdp->b_wptr\fR is set to
\fBdp->b_rptr + size\fR. Otherwise, any trailing message blocks are unaffected.
.SH RETURN VALUES
None.
.SH CONTEXT
This function can be called from user, kernel or interrupt context.
.SH SEE ALSO
\fBmcopyin\fR(9F), \fBcopyreq\fR(9S), \fBiocblk\fR(9S)
.sp
.LP
\fISTREAMS Programming Guide\fR