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 * String I/O Backend
29 *
30 * Simple backend to provide the ability to perform i/o reads from an in-memory
31 * string. This allows us to mdb_eval() a string -- by creating an i/o object
32 * out of it, we can then pass it to the parser as stdin.
33 */
34
35 #include <mdb/mdb_modapi.h>
36 #include <mdb/mdb_io_impl.h>
37 #include <mdb/mdb_string.h>
38 #include <mdb/mdb_err.h>
39
40 typedef struct str_data {
41 char *str_base; /* Pointer to private copy of string */
42 char *str_ptr; /* Current seek pointer */
43 size_t str_len; /* Length of string */
44 } str_data_t;
45
46 static ssize_t
strio_read(mdb_io_t * io,void * buf,size_t nbytes)47 strio_read(mdb_io_t *io, void *buf, size_t nbytes)
48 {
49 str_data_t *sd = io->io_data;
50 size_t left = sd->str_base + sd->str_len - sd->str_ptr;
51
52 if (left != 0) {
53 size_t obytes = nbytes < left ? nbytes : left;
54 (void) strncpy(buf, sd->str_ptr, obytes);
55 sd->str_ptr += obytes;
56 return (obytes);
57 }
58
59 return (0); /* At end of string: return EOF */
60 }
61
62 static off64_t
strio_seek(mdb_io_t * io,off64_t offset,int whence)63 strio_seek(mdb_io_t *io, off64_t offset, int whence)
64 {
65 str_data_t *sd = io->io_data;
66 char *nptr;
67
68 if (io->io_next != NULL)
69 return (IOP_SEEK(io->io_next, offset, whence));
70
71 switch (whence) {
72 case SEEK_SET:
73 nptr = sd->str_base + offset;
74 break;
75 case SEEK_CUR:
76 nptr = sd->str_ptr + offset;
77 break;
78 case SEEK_END:
79 nptr = sd->str_base + sd->str_len + offset;
80 break;
81 default:
82 return (set_errno(EINVAL));
83 }
84
85 if (nptr < sd->str_base || nptr > sd->str_ptr + sd->str_len)
86 return (set_errno(EINVAL));
87
88 sd->str_ptr = nptr;
89 return ((off64_t)(nptr - sd->str_base));
90 }
91
92 static void
strio_close(mdb_io_t * io)93 strio_close(mdb_io_t *io)
94 {
95 str_data_t *sd = io->io_data;
96
97 strfree(sd->str_base);
98 mdb_free(sd, sizeof (str_data_t));
99 }
100
101 static const char *
strio_name(mdb_io_t * io)102 strio_name(mdb_io_t *io)
103 {
104 if (io->io_next != NULL)
105 return (IOP_NAME(io->io_next));
106
107 return ("(string)");
108 }
109
110 static const mdb_io_ops_t strio_ops = {
111 .io_read = strio_read,
112 .io_write = no_io_write,
113 .io_seek = strio_seek,
114 .io_ctl = no_io_ctl,
115 .io_close = strio_close,
116 .io_name = strio_name,
117 .io_link = no_io_link,
118 .io_unlink = no_io_unlink,
119 .io_setattr = no_io_setattr,
120 .io_suspend = no_io_suspend,
121 .io_resume = no_io_resume,
122 };
123
124 mdb_io_t *
mdb_strio_create(const char * s)125 mdb_strio_create(const char *s)
126 {
127 mdb_io_t *io = mdb_alloc(sizeof (mdb_io_t), UM_SLEEP);
128 str_data_t *sd = mdb_alloc(sizeof (str_data_t), UM_SLEEP);
129
130 /*
131 * Our parser expects each command to end with '\n' or ';'. To
132 * simplify things for the caller, we append a trailing newline
133 * so the argvec string can be passed directly sans modifications.
134 */
135 sd->str_len = strlen(s) + 1;
136 sd->str_base = strndup(s, sd->str_len);
137 (void) strcat(sd->str_base, "\n");
138 sd->str_ptr = sd->str_base;
139
140 io->io_ops = &strio_ops;
141 io->io_data = sd;
142 io->io_next = NULL;
143 io->io_refcnt = 0;
144
145 return (io);
146 }
147
148 int
mdb_iob_isastr(mdb_iob_t * iob)149 mdb_iob_isastr(mdb_iob_t *iob)
150 {
151 mdb_io_t *io;
152
153 for (io = iob->iob_iop; io != NULL; io = io->io_next) {
154 if (io->io_ops == &strio_ops)
155 return (1);
156 }
157
158 return (0);
159 }
160