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, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright (c) 1997-2001 by Sun Microsystems, Inc.
24 * All rights reserved.
25 */
26
27 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 /*
30 * Log I/O Backend
31 *
32 * This backend provides the ability to form a T in an iob's output routine.
33 * We use this capability to provide interactive session logging. We create
34 * a log i/o and give it a pointer to another i/o backend representing the
35 * log file, and then stack this on top of the existing stdio i/o backend.
36 * As each write occurs, the log i/o writes to the log file, and also passes
37 * the write request along to io->io_next.
38 */
39
40 #include <mdb/mdb_modapi.h>
41 #include <mdb/mdb_err.h>
42 #include <mdb/mdb_io_impl.h>
43 #include <mdb/mdb.h>
44
45 static ssize_t
logio_read(mdb_io_t * io,void * buf,size_t nbytes)46 logio_read(mdb_io_t *io, void *buf, size_t nbytes)
47 {
48 mdb_io_t *logio = io->io_data;
49 ssize_t rbytes;
50
51 if (io->io_next != NULL) {
52 rbytes = IOP_READ(io->io_next, buf, nbytes);
53
54 if (rbytes > 0) {
55 (void) IOP_WRITE(logio, mdb.m_prompt, mdb.m_promptlen);
56 (void) IOP_WRITE(logio, buf, rbytes);
57 }
58
59 return (rbytes);
60 }
61
62 return (-1);
63 }
64
65 static ssize_t
logio_write(mdb_io_t * io,const void * buf,size_t nbytes)66 logio_write(mdb_io_t *io, const void *buf, size_t nbytes)
67 {
68 mdb_io_t *logio = io->io_data;
69 ssize_t wbytes;
70
71 if (io->io_next != NULL) {
72 wbytes = IOP_WRITE(io->io_next, buf, nbytes);
73
74 if (wbytes > 0)
75 (void) IOP_WRITE(logio, buf, wbytes);
76
77 return (wbytes);
78 }
79
80 return (-1);
81 }
82
83 static void
logio_close(mdb_io_t * io)84 logio_close(mdb_io_t *io)
85 {
86 mdb_io_rele(io->io_data);
87 }
88
89 static const char *
logio_name(mdb_io_t * io)90 logio_name(mdb_io_t *io)
91 {
92 if (io->io_next != NULL)
93 return (IOP_NAME(io->io_next));
94
95 return ("(log)");
96 }
97
98 static const mdb_io_ops_t logio_ops = {
99 logio_read,
100 logio_write,
101 no_io_seek,
102 no_io_ctl,
103 logio_close,
104 logio_name,
105 no_io_link,
106 no_io_unlink,
107 no_io_setattr,
108 no_io_suspend,
109 no_io_resume
110 };
111
112 mdb_io_t *
mdb_logio_create(mdb_io_t * logio)113 mdb_logio_create(mdb_io_t *logio)
114 {
115 mdb_io_t *io = mdb_alloc(sizeof (mdb_io_t), UM_SLEEP);
116
117 io->io_ops = &logio_ops;
118 io->io_data = mdb_io_hold(logio);
119 io->io_next = NULL;
120 io->io_refcnt = 0;
121
122 return (io);
123 }
124