.TH linkblk "" "" "STREAMS Data Structure"
.PC "Structure for a STREAMS multiplexor link"
.B "#include <sys/stream.h>"
.PP
The structure
.B linkblk
contains the information that a driver needs to establish
or break a multiplexor link.
It is part of the
.B M_DATA
portion of
.B M_IOCTL
messages generated the
.B ioctl()
calls
.BR I_LINK ,
.BR I_UNLINK ,
.BR I_PLINK ,
and
.BR I_PUNLINK .
The driver does not create this structure.
.PP
A driver or module can use the following fields within
.BR linkblk :
.IP "\fBqueue_t *l_qtop\fR" 1.25i
The address of the multiplexing driver's write queue.
Set this field to NULL if the link persists across a close of the driver.
.IP "\fBqueue_t *l_qbot\fR"
The address of the lower stream's upper write queue.
These queues'
.B qinit
structures
are those that the driver's
.B streamtab
structure specifies for lower processing.
.IP "\fBint l_index\fR"
The multiplexing link in the system.
.SH "See Also"
.B
datab,
DDI/DKI data structures,
iocblk,
msgb,
qinit,
streamtab
.R
