xref: /onnv-gate/usr/src/uts/common/io/pipemod.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright (c) 1997, by Sun Microsystems, Inc.
24*0Sstevel@tonic-gate  * All rights reserved.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28*0Sstevel@tonic-gate /*	  All Rights Reserved  	*/
29*0Sstevel@tonic-gate 
30*0Sstevel@tonic-gate 
31*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
32*0Sstevel@tonic-gate 
33*0Sstevel@tonic-gate /*
34*0Sstevel@tonic-gate  * This module switches the read and write flush bits for each
35*0Sstevel@tonic-gate  * M_FLUSH control message it receives. It's intended usage is to
36*0Sstevel@tonic-gate  * properly flush a STREAMS-based pipe.
37*0Sstevel@tonic-gate  */
38*0Sstevel@tonic-gate #include <sys/types.h>
39*0Sstevel@tonic-gate #include <sys/param.h>
40*0Sstevel@tonic-gate #include <sys/errno.h>
41*0Sstevel@tonic-gate #include <sys/stream.h>
42*0Sstevel@tonic-gate #include <sys/stropts.h>
43*0Sstevel@tonic-gate 
44*0Sstevel@tonic-gate #include <sys/conf.h>
45*0Sstevel@tonic-gate #include <sys/modctl.h>
46*0Sstevel@tonic-gate 
47*0Sstevel@tonic-gate /*ARGSUSED*/
48*0Sstevel@tonic-gate static int
pipeopen(queue_t * rqp,dev_t * devp,int flag,int sflag,cred_t * crp)49*0Sstevel@tonic-gate pipeopen(queue_t *rqp, dev_t *devp, int flag, int sflag, cred_t *crp)
50*0Sstevel@tonic-gate {
51*0Sstevel@tonic-gate 	qprocson(rqp);
52*0Sstevel@tonic-gate 	return (0);
53*0Sstevel@tonic-gate }
54*0Sstevel@tonic-gate 
55*0Sstevel@tonic-gate /*ARGSUSED*/
56*0Sstevel@tonic-gate static int
pipeclose(queue_t * q,int cflag,cred_t * crp)57*0Sstevel@tonic-gate pipeclose(queue_t *q, int cflag, cred_t *crp)
58*0Sstevel@tonic-gate {
59*0Sstevel@tonic-gate 	qprocsoff(q);
60*0Sstevel@tonic-gate 	return (0);
61*0Sstevel@tonic-gate }
62*0Sstevel@tonic-gate 
63*0Sstevel@tonic-gate /*
64*0Sstevel@tonic-gate  * Use same put procedure for write and read queues.
65*0Sstevel@tonic-gate  * If mp is an M_FLUSH message, switch the FLUSHW to FLUSHR and
66*0Sstevel@tonic-gate  * the FLUSHR to FLUSHW and send the message on.  If mp is not an
67*0Sstevel@tonic-gate  * M_FLUSH message, send it on with out processing.
68*0Sstevel@tonic-gate  */
69*0Sstevel@tonic-gate static int
pipeput(queue_t * qp,mblk_t * mp)70*0Sstevel@tonic-gate pipeput(queue_t *qp, mblk_t *mp)
71*0Sstevel@tonic-gate {
72*0Sstevel@tonic-gate 	switch (mp->b_datap->db_type) {
73*0Sstevel@tonic-gate 	case M_FLUSH:
74*0Sstevel@tonic-gate 		if (!(*mp->b_rptr & FLUSHR && *mp->b_rptr & FLUSHW)) {
75*0Sstevel@tonic-gate 			if (*mp->b_rptr & FLUSHW) {
76*0Sstevel@tonic-gate 				*mp->b_rptr |= FLUSHR;
77*0Sstevel@tonic-gate 				*mp->b_rptr &= ~FLUSHW;
78*0Sstevel@tonic-gate 			} else {
79*0Sstevel@tonic-gate 				*mp->b_rptr |= FLUSHW;
80*0Sstevel@tonic-gate 				*mp->b_rptr &= ~FLUSHR;
81*0Sstevel@tonic-gate 			}
82*0Sstevel@tonic-gate 		}
83*0Sstevel@tonic-gate 		break;
84*0Sstevel@tonic-gate 
85*0Sstevel@tonic-gate 	default:
86*0Sstevel@tonic-gate 		break;
87*0Sstevel@tonic-gate 	}
88*0Sstevel@tonic-gate 	putnext(qp, mp);
89*0Sstevel@tonic-gate 	return (0);
90*0Sstevel@tonic-gate }
91*0Sstevel@tonic-gate 
92*0Sstevel@tonic-gate static struct module_info pipe_info = {
93*0Sstevel@tonic-gate 	1003, "pipemod", 0, INFPSZ, STRHIGH, STRLOW
94*0Sstevel@tonic-gate };
95*0Sstevel@tonic-gate 
96*0Sstevel@tonic-gate static struct qinit piperinit = {
97*0Sstevel@tonic-gate 	pipeput, NULL, pipeopen, pipeclose, NULL, &pipe_info, NULL
98*0Sstevel@tonic-gate };
99*0Sstevel@tonic-gate 
100*0Sstevel@tonic-gate static struct qinit pipewinit = {
101*0Sstevel@tonic-gate 	pipeput, NULL, NULL, NULL, NULL, &pipe_info, NULL
102*0Sstevel@tonic-gate };
103*0Sstevel@tonic-gate 
104*0Sstevel@tonic-gate static struct streamtab pipeinfo = { &piperinit, &pipewinit, NULL, NULL };
105*0Sstevel@tonic-gate 
106*0Sstevel@tonic-gate static struct fmodsw fsw = {
107*0Sstevel@tonic-gate 	"pipemod",
108*0Sstevel@tonic-gate 	&pipeinfo,
109*0Sstevel@tonic-gate 	D_NEW | D_MP
110*0Sstevel@tonic-gate };
111*0Sstevel@tonic-gate 
112*0Sstevel@tonic-gate static struct modlstrmod modlstrmod = {
113*0Sstevel@tonic-gate 	&mod_strmodops, "pipe flushing module", &fsw
114*0Sstevel@tonic-gate };
115*0Sstevel@tonic-gate 
116*0Sstevel@tonic-gate static struct modlinkage modlinkage = {
117*0Sstevel@tonic-gate 	MODREV_1, &modlstrmod, NULL
118*0Sstevel@tonic-gate };
119*0Sstevel@tonic-gate 
120*0Sstevel@tonic-gate int
_init(void)121*0Sstevel@tonic-gate _init(void)
122*0Sstevel@tonic-gate {
123*0Sstevel@tonic-gate 	return (mod_install(&modlinkage));
124*0Sstevel@tonic-gate }
125*0Sstevel@tonic-gate 
126*0Sstevel@tonic-gate int
_fini(void)127*0Sstevel@tonic-gate _fini(void)
128*0Sstevel@tonic-gate {
129*0Sstevel@tonic-gate 	return (mod_remove(&modlinkage));
130*0Sstevel@tonic-gate }
131*0Sstevel@tonic-gate 
132*0Sstevel@tonic-gate int
_info(struct modinfo * modinfop)133*0Sstevel@tonic-gate _info(struct modinfo *modinfop)
134*0Sstevel@tonic-gate {
135*0Sstevel@tonic-gate 	return (mod_info(&modlinkage, modinfop));
136*0Sstevel@tonic-gate }
137