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 * String I/O Backend
31 *
32 * Simple backend to provide the ability to perform i/o reads from an in-memory
33 * string. This allows us to mdb_eval() a string -- by creating an i/o object
34 * out of it, we can then pass it to the parser as stdin.
35 */
36
37 #include <mdb/mdb_modapi.h>
38 #include <mdb/mdb_io_impl.h>
39 #include <mdb/mdb_string.h>
40 #include <mdb/mdb_err.h>
41
42 typedef struct str_data {
43 char *str_base; /* Pointer to private copy of string */
44 char *str_ptr; /* Current seek pointer */
45 size_t str_len; /* Length of string */
46 } str_data_t;
47
48 static ssize_t
strio_read(mdb_io_t * io,void * buf,size_t nbytes)49 strio_read(mdb_io_t *io, void *buf, size_t nbytes)
50 {
51 str_data_t *sd = io->io_data;
52 size_t left = sd->str_base + sd->str_len - sd->str_ptr;
53
54 if (left != 0) {
55 size_t obytes = nbytes < left ? nbytes : left;
56 (void) strncpy(buf, sd->str_ptr, obytes);
57 sd->str_ptr += obytes;
58 return (obytes);
59 }
60
61 return (0); /* At end of string: return EOF */
62 }
63
64 static off64_t
strio_seek(mdb_io_t * io,off64_t offset,int whence)65 strio_seek(mdb_io_t *io, off64_t offset, int whence)
66 {
67 str_data_t *sd = io->io_data;
68 char *nptr;
69
70 if (io->io_next != NULL)
71 return (IOP_SEEK(io->io_next, offset, whence));
72
73 switch (whence) {
74 case SEEK_SET:
75 nptr = sd->str_base + offset;
76 break;
77 case SEEK_CUR:
78 nptr = sd->str_ptr + offset;
79 break;
80 case SEEK_END:
81 nptr = sd->str_base + sd->str_len + offset;
82 break;
83 default:
84 return (set_errno(EINVAL));
85 }
86
87 if (nptr < sd->str_base || nptr > sd->str_ptr + sd->str_len)
88 return (set_errno(EINVAL));
89
90 sd->str_ptr = nptr;
91 return ((off64_t)(nptr - sd->str_base));
92 }
93
94 static void
strio_close(mdb_io_t * io)95 strio_close(mdb_io_t *io)
96 {
97 str_data_t *sd = io->io_data;
98
99 strfree(sd->str_base);
100 mdb_free(sd, sizeof (str_data_t));
101 }
102
103 static const char *
strio_name(mdb_io_t * io)104 strio_name(mdb_io_t *io)
105 {
106 if (io->io_next != NULL)
107 return (IOP_NAME(io->io_next));
108
109 return ("(string)");
110 }
111
112 static const mdb_io_ops_t strio_ops = {
113 strio_read,
114 no_io_write,
115 strio_seek,
116 no_io_ctl,
117 strio_close,
118 strio_name,
119 no_io_link,
120 no_io_unlink,
121 no_io_setattr,
122 no_io_suspend,
123 no_io_resume
124 };
125
126 mdb_io_t *
mdb_strio_create(const char * s)127 mdb_strio_create(const char *s)
128 {
129 mdb_io_t *io = mdb_alloc(sizeof (mdb_io_t), UM_SLEEP);
130 str_data_t *sd = mdb_alloc(sizeof (str_data_t), UM_SLEEP);
131
132 /*
133 * Our parser expects each command to end with '\n' or ';'. To
134 * simplify things for the caller, we append a trailing newline
135 * so the argvec string can be passed directly sans modifications.
136 */
137 sd->str_len = strlen(s) + 1;
138 sd->str_base = strndup(s, sd->str_len);
139 (void) strcat(sd->str_base, "\n");
140 sd->str_ptr = sd->str_base;
141
142 io->io_ops = &strio_ops;
143 io->io_data = sd;
144 io->io_next = NULL;
145 io->io_refcnt = 0;
146
147 return (io);
148 }
149
150 int
mdb_iob_isastr(mdb_iob_t * iob)151 mdb_iob_isastr(mdb_iob_t *iob)
152 {
153 mdb_io_t *io;
154
155 for (io = iob->iob_iop; io != NULL; io = io->io_next) {
156 if (io->io_ops == &strio_ops)
157 return (1);
158 }
159
160 return (0);
161 }
162