xref: /freebsd/sys/geom/virstor/binstream.c (revision 19fae0f66023a97a9b464b3beeeabb2081f575b3)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2005 Ivan Voras <ivoras@gmail.com>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 // $Id: binstream.c,v 1.1 2006/07/05 10:47:54 ivoras Exp $
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/endian.h>
35 #include <sys/param.h>
36 
37 #include <geom/virstor/binstream.h>
38 
39 /* "Open" a binary stream for reading */
40 void
41 bs_open(bin_stream_t * bs, void *data)
42 {
43 	bs->data = (char *)data;
44 	bs->pos = 0;
45 }
46 
47 /* "Reset" position in binary stream to zero */
48 void
49 bs_reset(bin_stream_t * bs)
50 {
51 	bs->pos = 0;
52 }
53 
54 /* Write a zero-terminated string; return next position */
55 unsigned
56 bs_write_str(bin_stream_t * bs, char *data)
57 {
58 	int		len = 0;
59 	do {
60 		*(bs->data + bs->pos + len) = *data;
61 		len++;
62 	} while (*(data++) != '\0');
63 	bs->pos += len;
64 	return bs->pos;
65 }
66 
67 /* Write an arbitrary buffer; return next position */
68 unsigned
69 bs_write_buf(bin_stream_t * bs, char *data, unsigned data_size)
70 {
71 	unsigned	i;
72 	for (i = 0; i < data_size; i++)
73 		*(bs->data + bs->pos + i) = *(data + i);
74 	bs->pos += data_size;
75 	return bs->pos;
76 }
77 
78 /* Write a 8bit uint; return next position. */
79 unsigned
80 bs_write_u8(bin_stream_t * bs, uint8_t data)
81 {
82 	*((uint8_t *) (bs->data + bs->pos)) = data;
83 	return ++(bs->pos);
84 }
85 
86 /* Write a 16bit uint; return next position. */
87 unsigned
88 bs_write_u16(bin_stream_t * bs, uint16_t data)
89 {
90 	le16enc(bs->data + bs->pos, data);
91 	return (bs->pos += 2);
92 }
93 
94 /* Write a 32bit uint; return next position. */
95 unsigned
96 bs_write_u32(bin_stream_t * bs, uint32_t data)
97 {
98 	le32enc(bs->data + bs->pos, data);
99 	return (bs->pos += 4);
100 }
101 
102 /* Write a 64bit uint; return next position. */
103 unsigned
104 bs_write_u64(bin_stream_t * bs, uint64_t data)
105 {
106 	le64enc(bs->data + bs->pos, data);
107 	return (bs->pos += 8);
108 }
109 
110 /* Read a 8bit uint & return it */
111 uint8_t
112 bs_read_u8(bin_stream_t * bs)
113 {
114 	uint8_t		data = *((uint8_t *) (bs->data + bs->pos));
115 	bs->pos++;
116 	return data;
117 }
118 
119 /*
120  * Read a null-terminated string from stream into a buffer; buf_size is size
121  * of the buffer, including the final \0. Returns buf pointer or NULL if
122  * garbage input.
123  */
124 char*
125 bs_read_str(bin_stream_t * bs, char *buf, unsigned buf_size)
126 {
127 	unsigned	len = 0;
128 	char           *work_buf = buf;
129 	if (buf == NULL || buf_size < 1)
130 		return NULL;
131 	do {
132 		*work_buf = *(bs->data + bs->pos + len);
133 	} while (len++ < buf_size - 1 && *(work_buf++) != '\0');
134 	*(buf + buf_size - 1) = '\0';
135 	bs->pos += len;
136 	return buf;
137 }
138 
139 /* Read an arbitrary buffer. */
140 void
141 bs_read_buf(bin_stream_t * bs, char *buf, unsigned buf_size)
142 {
143 	unsigned	i;
144 	for (i = 0; i < buf_size; i++)
145 		*(buf + i) = *(bs->data + bs->pos + i);
146 	bs->pos += buf_size;
147 }
148 
149 /* Read a 16bit uint & return it */
150 uint16_t
151 bs_read_u16(bin_stream_t * bs)
152 {
153 	uint16_t	data = le16dec(bs->data + bs->pos);
154 	bs->pos += 2;
155 	return data;
156 }
157 
158 /* Read a 32bit uint & return it */
159 uint32_t
160 bs_read_u32(bin_stream_t * bs)
161 {
162 	uint32_t	data = le32dec(bs->data + bs->pos);
163 	bs->pos += 4;
164 	return data;
165 }
166 
167 /* Read a 64bit uint & return it */
168 uint64_t
169 bs_read_u64(bin_stream_t * bs)
170 {
171 	uint64_t	data = le64dec(bs->data + bs->pos);
172 	bs->pos += 8;
173 	return data;
174 }
175