'\" te
.\" Copyright (c) 2003, 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 LDI_PUTMSG 9F "Jun 3, 2003"
.SH NAME
ldi_putmsg, ldi_getmsg \- Read/write message blocks from/to a stream
.SH SYNOPSIS
.LP
.nf
#include <sys/sunldi.h>

\fBint\fR \fBldi_putmsg\fR(\fBldi_handle_t\fR\fI lh\fR, \fBmblk_t *\fR\fIsmp\fR);
.fi

.LP
.nf
\fBint\fR \fB ldi_getmsg\fR(\fBldi_handle_t\fR \fIlh\fR, \fBmblk_t **\fR\fIrmp\fR, \fBtimestruc_t *\fR\fItimeo\fR);
.fi

.SH PARAMETERS
.sp
.ne 2
.na
\fB\fIlh\fR \fR
.ad
.RS 10n
Layered handle.
.RE

.sp
.ne 2
.na
\fB\fIsmp\fR \fR
.ad
.RS 10n
Message block to send.
.RE

.sp
.ne 2
.na
\fB\fIrmp\fR \fR
.ad
.RS 10n
Message block to receive.
.RE

.sp
.ne 2
.na
\fB\fItimeo\fR \fR
.ad
.RS 10n
Optional timeout for data reception.
.RE

.SH DESCRIPTION
.sp
.LP
The \fBldi_putmsg\fR function allows a caller to send a message block to a
streams device specified by the layered handle \fIlh\fR. Once the message (smp)
has been passed to \fBldi_putmsg()\fR, the caller must not free the message
even if an error occurs.
.sp
.LP
The \fBldi_getmsg()\fR function allows a caller to receive a message block from
a streams device specified by the layered handle \fIlh\fR. Callers must free
the message received with \fBfreemsg\fR(9F).
.sp
.LP
If a NULL timeout value is specified when the caller receives a message, the
caller sleeps until a message is received.
.SH RETURN VALUES
.sp
.LP
The \fBldi_putmsg()\fR and \fBldi_getmsg()\fR functions return \fB0\fR upon
success. If a failure occurs before the request is passed to the device, the
possible return values are shown below. Otherwise any other error number may be
returned by the device.
.sp
.ne 2
.na
\fBEINVAL\fR
.ad
.RS 11n
Invalid input parameters.
.RE

.sp
.ne 2
.na
\fBENOTSUP\fR
.ad
.RS 11n
Operation is not supported for this device.
.sp
The \fBldi_getmsg()\fR function may also return:
.sp
.ne 2
.na
\fBETIME\fR
.ad
.RS 9n
Returned if the timeout \fBtimeo\fR expires with no messages received.
.RE

.RE

.SH CONTEXT
.sp
.LP
These functions may be called from user or kernel context.