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 /*
28 * Log I/O Backend
29 *
30 * This backend provides the ability to form a T in an iob's output routine.
31 * We use this capability to provide interactive session logging. We create
32 * a log i/o and give it a pointer to another i/o backend representing the
33 * log file, and then stack this on top of the existing stdio i/o backend.
34 * As each write occurs, the log i/o writes to the log file, and also passes
35 * the write request along to io->io_next.
36 */
37
38 #include <mdb/mdb_modapi.h>
39 #include <mdb/mdb_err.h>
40 #include <mdb/mdb_io_impl.h>
41 #include <mdb/mdb.h>
42
43 static ssize_t
logio_read(mdb_io_t * io,void * buf,size_t nbytes)44 logio_read(mdb_io_t *io, void *buf, size_t nbytes)
45 {
46 mdb_io_t *logio = io->io_data;
47 ssize_t rbytes;
48
49 if (io->io_next != NULL) {
50 rbytes = IOP_READ(io->io_next, buf, nbytes);
51
52 if (rbytes > 0) {
53 (void) IOP_WRITE(logio, mdb.m_prompt, mdb.m_promptlen);
54 (void) IOP_WRITE(logio, buf, rbytes);
55 }
56
57 return (rbytes);
58 }
59
60 return (-1);
61 }
62
63 static ssize_t
logio_write(mdb_io_t * io,const void * buf,size_t nbytes)64 logio_write(mdb_io_t *io, const void *buf, size_t nbytes)
65 {
66 mdb_io_t *logio = io->io_data;
67 ssize_t wbytes;
68
69 if (io->io_next != NULL) {
70 wbytes = IOP_WRITE(io->io_next, buf, nbytes);
71
72 if (wbytes > 0)
73 (void) IOP_WRITE(logio, buf, wbytes);
74
75 return (wbytes);
76 }
77
78 return (-1);
79 }
80
81 static void
logio_close(mdb_io_t * io)82 logio_close(mdb_io_t *io)
83 {
84 mdb_io_rele(io->io_data);
85 }
86
87 static const char *
logio_name(mdb_io_t * io)88 logio_name(mdb_io_t *io)
89 {
90 if (io->io_next != NULL)
91 return (IOP_NAME(io->io_next));
92
93 return ("(log)");
94 }
95
96 static const mdb_io_ops_t logio_ops = {
97 .io_read = logio_read,
98 .io_write = logio_write,
99 .io_seek = no_io_seek,
100 .io_ctl = no_io_ctl,
101 .io_close = logio_close,
102 .io_name = logio_name,
103 .io_link = no_io_link,
104 .io_unlink = no_io_unlink,
105 .io_setattr = no_io_setattr,
106 .io_suspend = no_io_suspend,
107 .io_resume = no_io_resume
108 };
109
110 mdb_io_t *
mdb_logio_create(mdb_io_t * logio)111 mdb_logio_create(mdb_io_t *logio)
112 {
113 mdb_io_t *io = mdb_alloc(sizeof (mdb_io_t), UM_SLEEP);
114
115 io->io_ops = &logio_ops;
116 io->io_data = mdb_io_hold(logio);
117 io->io_next = NULL;
118 io->io_refcnt = 0;
119
120 return (io);
121 }
122