xref: /illumos-gate/usr/src/uts/common/io/strredirm.c (revision 71269a2275bf5a143dad6461eee2710a344e7261)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * Redirection STREAMS module.
31  *
32  * This module is intended for use in conjunction with instantiations of the
33  * redirection driver.  Its purpose in life is to detect when the stream that
34  * it's pushed on is closed, thereupon calling back into the redirection
35  * driver so that the driver can cancel redirection to the stream.
36  * It passes all messages on unchanged, in both directions.
37  */
38 
39 #include <sys/types.h>
40 #include <sys/param.h>
41 #include <sys/errno.h>
42 #include <sys/stream.h>
43 #include <sys/stropts.h>
44 #include <sys/debug.h>
45 #include <sys/strredir.h>
46 #include <sys/strsubr.h>
47 #include <sys/strsun.h>
48 #include <sys/conf.h>
49 #include <sys/ddi.h>
50 #include <sys/sunddi.h>
51 #include <sys/modctl.h>
52 
53 /*
54  * Forward declarations for private routines.
55  */
56 static int	wcmopen(queue_t	*, dev_t *, int, int, cred_t *);
57 static int	wcmclose(queue_t *, int, cred_t *);
58 static int	wcmrput(queue_t *, mblk_t *);
59 
60 static struct module_info	wcminfo = {
61 	STRREDIR_MODID,
62 	STRREDIR_MOD,
63 	0,
64 	INFPSZ,
65 	5120,
66 	1024
67 };
68 
69 static struct qinit	wcmrinit = {
70 	wcmrput,		/* put */
71 	NULL,			/* service */
72 	wcmopen,		/* open */
73 	wcmclose,		/* close */
74 	NULL,			/* qadmin */
75 	&wcminfo,
76 	NULL			/* mstat */
77 };
78 
79 static struct qinit	wcmwinit = {
80 	(int (*)())putnext,	/* put */
81 	NULL,			/* service */
82 	wcmopen,		/* open */
83 	wcmclose,		/* close */
84 	NULL,			/* qadmin */
85 	&wcminfo,
86 	NULL			/* mstat */
87 };
88 
89 static struct streamtab	redirminfo = {
90 	&wcmrinit,
91 	&wcmwinit,
92 	NULL,
93 	NULL
94 };
95 
96 static struct fmodsw fsw = {
97 	"redirmod",
98 	&redirminfo,
99 	D_MP
100 };
101 
102 static struct modlstrmod modlstrmod = {
103 	&mod_strmodops,
104 	"redirection module",
105 	&fsw
106 };
107 
108 static struct modlinkage modlinkage = {
109 	MODREV_1, &modlstrmod, NULL
110 };
111 
112 int
113 _init()
114 {
115 	return (mod_install(&modlinkage));
116 }
117 
118 int
119 _fini()
120 {
121 	return (EBUSY);
122 }
123 
124 int
125 _info(struct modinfo *modinfop)
126 {
127 	return (mod_info(&modlinkage, modinfop));
128 }
129 
130 /* ARGSUSED */
131 static int
132 wcmopen(queue_t *q, dev_t *dev, int flag, int sflag, cred_t *cred)
133 {
134 	if (sflag != MODOPEN)
135 		return (EINVAL);
136 	qprocson(q);
137 	return (0);
138 }
139 
140 /* ARGSUSED */
141 static int
142 wcmclose(queue_t *q, int flag, cred_t *cred)
143 {
144 	qprocsoff(q);
145 	srpop(q->q_stream->sd_vnode, B_TRUE);
146 	return (0);
147 }
148 
149 /*
150  * Upstream messages are passed unchanged.
151  * If a hangup occurs the target is no longer usable, so deprecate it.
152  */
153 static int
154 wcmrput(queue_t *q, mblk_t *mp)
155 {
156 	if (DB_TYPE(mp) == M_HANGUP)
157 		/* Don't block waiting for outstanding operations to complete */
158 		srpop(q->q_stream->sd_vnode, B_FALSE);
159 	putnext(q, mp);
160 	return (0);
161 }
162