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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (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.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 1997, by Sun Microsystems, Inc.
* All rights reserved.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* This module switches the read and write flush bits for each
* M_FLUSH control message it receives. It's intended usage is to
* properly flush a STREAMS-based pipe.
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/errno.h>
#include <sys/stream.h>
#include <sys/stropts.h>
#include <sys/conf.h>
#include <sys/modctl.h>
/*ARGSUSED*/
static int
pipeopen(queue_t *rqp, dev_t *devp, int flag, int sflag, cred_t *crp)
{
qprocson(rqp);
return (0);
}
/*ARGSUSED*/
static int
pipeclose(queue_t *q, int cflag, cred_t *crp)
{
qprocsoff(q);
return (0);
}
/*
* Use same put procedure for write and read queues.
* If mp is an M_FLUSH message, switch the FLUSHW to FLUSHR and
* the FLUSHR to FLUSHW and send the message on. If mp is not an
* M_FLUSH message, send it on with out processing.
*/
static int
pipeput(queue_t *qp, mblk_t *mp)
{
switch (mp->b_datap->db_type) {
case M_FLUSH:
if (!(*mp->b_rptr & FLUSHR && *mp->b_rptr & FLUSHW)) {
if (*mp->b_rptr & FLUSHW) {
*mp->b_rptr |= FLUSHR;
*mp->b_rptr &= ~FLUSHW;
} else {
*mp->b_rptr |= FLUSHW;
*mp->b_rptr &= ~FLUSHR;
}
}
break;
default:
break;
}
putnext(qp, mp);
return (0);
}
static struct module_info pipe_info = {
1003, "pipemod", 0, INFPSZ, STRHIGH, STRLOW
};
static struct qinit piperinit = {
pipeput, NULL, pipeopen, pipeclose, NULL, &pipe_info, NULL
};
static struct qinit pipewinit = {
pipeput, NULL, NULL, NULL, NULL, &pipe_info, NULL
};
static struct streamtab pipeinfo = { &piperinit, &pipewinit, NULL, NULL };
static struct fmodsw fsw = {
"pipemod",
&pipeinfo,
D_NEW | D_MP
};
static struct modlstrmod modlstrmod = {
&mod_strmodops, "pipe flushing module", &fsw
};
static struct modlinkage modlinkage = {
MODREV_1, &modlstrmod, NULL
};
int
_init(void)
{
return (mod_install(&modlinkage));
}
int
_fini(void)
{
return (mod_remove(&modlinkage));
}
int
_info(struct modinfo *modinfop)
{
return (mod_info(&modlinkage, modinfop));
}
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