1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
|
/*
* section and descriptor parser
*
* Copyright (C) 2005 Kenneth Aafloy (kenneth@linuxtv.org)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
#ifndef _UCSI_DESCRIPTOR_H
#define _UCSI_DESCRIPTOR_H 1
#ifdef __cplusplus
extern "C"
{
#endif
#include <libucsi/endianops.h>
#include <stdint.h>
#include <stdlib.h>
/**
* Generic descriptor header.
*/
struct descriptor {
uint8_t tag;
uint8_t len;
} __ucsi_packed;
/**
* Retreive pointer to the next descriptor structure.
*
* @param buf The buffer of descriptors.
* @param len Size of the buffer.
* @param pos Current descriptor.
* @return Pointer to next descriptor, or NULL if there are none.
*/
static inline struct descriptor *
next_descriptor(uint8_t * buf, size_t len, struct descriptor * pos)
{
uint8_t* next;
if (pos == NULL)
return NULL;
next = (uint8_t*) pos + 2 + pos->len;
if (next >= buf + len)
return NULL;
return (struct descriptor *) next;
}
/**
* The unknown descriptor.
*/
struct unknown_descriptor {
struct descriptor d;
/* uint8_t data [] */
} __ucsi_packed;
/**
* Retrieve pointer to the unknown descriptor's data field.
*
* @param d The descriptor.
* @return Pointer to the data field.
*/
static inline uint8_t *
unknown_descriptor_data(struct unknown_descriptor *d)
{
return (uint8_t *) d + sizeof(struct unknown_descriptor);
}
/**
* Retrieve size of unknown descriptor's data field.
*
* @param d The descriptor.
* @return Size of data field in bytes.
*/
static inline int
unknown_descriptor_data_size(struct unknown_descriptor *d)
{
return d->d.len;
}
/******************************** PRIVATE CODE ********************************/
static inline int verify_descriptors(uint8_t * buf, size_t len)
{
size_t pos = 0;
while (pos < len) {
if ((pos + 2) > len)
return -1;
pos += 2 + buf[pos+1];
}
if (pos != len)
return -1;
return 0;
}
#ifdef __cplusplus
}
#endif
#endif
|
