xref: /freebsd/sys/geom/virstor/binstream.c (revision 41059135ce931c0f1014a999ffabc6bc470ce856)
1 /*-
2  * Copyright (c) 2005 Ivan Voras <ivoras@gmail.com>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 // $Id: binstream.c,v 1.1 2006/07/05 10:47:54 ivoras Exp $
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/endian.h>
33 #include <sys/param.h>
34 
35 #include <geom/virstor/binstream.h>
36 
37 
38 /* "Open" a binary stream for reading */
39 void
40 bs_open(bin_stream_t * bs, void *data)
41 {
42 	bs->data = (char *)data;
43 	bs->pos = 0;
44 }
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 
68 /* Write an arbitrary buffer; return next position */
69 unsigned
70 bs_write_buf(bin_stream_t * bs, char *data, unsigned data_size)
71 {
72 	unsigned	i;
73 	for (i = 0; i < data_size; i++)
74 		*(bs->data + bs->pos + i) = *(data + i);
75 	bs->pos += data_size;
76 	return bs->pos;
77 }
78 
79 
80 /* Write a 8bit uint; return next position. */
81 unsigned
82 bs_write_u8(bin_stream_t * bs, uint8_t data)
83 {
84 	*((uint8_t *) (bs->data + bs->pos)) = data;
85 	return ++(bs->pos);
86 }
87 
88 
89 /* Write a 16bit uint; return next position. */
90 unsigned
91 bs_write_u16(bin_stream_t * bs, uint16_t data)
92 {
93 	le16enc(bs->data + bs->pos, data);
94 	return (bs->pos += 2);
95 }
96 
97 
98 /* Write a 32bit uint; return next position. */
99 unsigned
100 bs_write_u32(bin_stream_t * bs, uint32_t data)
101 {
102 	le32enc(bs->data + bs->pos, data);
103 	return (bs->pos += 4);
104 }
105 
106 
107 /* Write a 64bit uint; return next position. */
108 unsigned
109 bs_write_u64(bin_stream_t * bs, uint64_t data)
110 {
111 	le64enc(bs->data + bs->pos, data);
112 	return (bs->pos += 8);
113 }
114 
115 
116 /* Read a 8bit uint & return it */
117 uint8_t
118 bs_read_u8(bin_stream_t * bs)
119 {
120 	uint8_t		data = *((uint8_t *) (bs->data + bs->pos));
121 	bs->pos++;
122 	return data;
123 }
124 
125 
126 /*
127  * Read a null-terminated string from stream into a buffer; buf_size is size
128  * of the buffer, including the final \0. Returns buf pointer or NULL if
129  * garbage input.
130  */
131 char*
132 bs_read_str(bin_stream_t * bs, char *buf, unsigned buf_size)
133 {
134 	unsigned	len = 0;
135 	char           *work_buf = buf;
136 	if (buf == NULL || buf_size < 1)
137 		return NULL;
138 	do {
139 		*work_buf = *(bs->data + bs->pos + len);
140 	} while (len++ < buf_size - 1 && *(work_buf++) != '\0');
141 	*(buf + buf_size - 1) = '\0';
142 	bs->pos += len;
143 	return buf;
144 }
145 
146 
147 /* Read an arbitrary buffer. */
148 void
149 bs_read_buf(bin_stream_t * bs, char *buf, unsigned buf_size)
150 {
151 	unsigned	i;
152 	for (i = 0; i < buf_size; i++)
153 		*(buf + i) = *(bs->data + bs->pos + i);
154 	bs->pos += buf_size;
155 }
156 
157 
158 /* Read a 16bit uint & return it */
159 uint16_t
160 bs_read_u16(bin_stream_t * bs)
161 {
162 	uint16_t	data = le16dec(bs->data + bs->pos);
163 	bs->pos += 2;
164 	return data;
165 }
166 
167 
168 /* Read a 32bit uint & return it */
169 uint32_t
170 bs_read_u32(bin_stream_t * bs)
171 {
172 	uint32_t	data = le32dec(bs->data + bs->pos);
173 	bs->pos += 4;
174 	return data;
175 }
176 
177 
178 /* Read a 64bit uint & return it */
179 uint64_t
180 bs_read_u64(bin_stream_t * bs)
181 {
182 	uint64_t	data = le64dec(bs->data + bs->pos);
183 	bs->pos += 8;
184 	return data;
185 }
186