Code associated with Thomas F. Herbert's "Implementing Network Protocols and Drivers with Streams" April 1997 on page 28

Listing 1
Multiplexing module declarations.

#include <stream.h>
static int mopen(queue_t *q, int dev, int flag, int 
   sflag);
static int mclose(queue_t *q);
static int murput(queue_t *q, mblk_t *mp);
static int mursrv(queue_t *q);
static int muwput(queue_t *q, mblk_t *mp);
static int muwsrv(queue_t *q);
/*
 * The following 4 routines allow this module
 * to support lower multiplexing.
 */
static int mlrput(queue_t *q, mblk_t *mp);
static int mlrsrv(queue_t *q);
static int mlwput(queue_t *q, mblk_t *mp);
static int mlwsrv(queue_t *q);
/* 
 * The module_info structure below consists of:
 * Mod ID, Name, Min Size, Max Size, Hi wat, Lo wat
 */
static struct module_info muinfo = {
   0, ³mod², 0, INFPSZ, 1024, 256};

static struct qinit murinit = { /* upper read */
   murput, mursrc, mopen, mclose, NULL, &muinfo, 
   NULL 
};
static struct qinit muwinit = { /* upper write */
   muwput, muwsrc, NULL, NULL, NULL, &muinfo, NULL 
};
/*
 * The following 2 structures are to support lower 
 * multiplexing.
 */
static struct qinit mlrinit = { /* lower read */
   mlrput, mlrsrc, NULL, NULL, NULL, &muinfo, NULL };
static struct qinit mlwinit = { /* lower write */
   mlwput, mlwsrc, NULL, NULL, NULL, &muinfo, NULL };
/* The following declaration must be global */
struct streamtab minfo = {
   murinit; /* Upper read q */
   mwinit;  /* Upper write q*/
/* The next 2 queues are for multiplexing.*/
   mlrinit; /* Lower read q */
   mlwinit; /* Lower write q*/
}