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
|
// OpenVPN -- An application to securely tunnel IP networks
// over a single port, with support for SSL/TLS-based
// session authentication and key exchange,
// packet encryption, packet authentication, and
// packet compression.
//
// Copyright (C) 2012- OpenVPN Inc.
//
// SPDX-License-Identifier: MPL-2.0 OR AGPL-3.0-only WITH openvpn3-openssl-exception
//
// A general-purpose circular list collection class.
// Used by the OpenVPN anti-replay logic.
#ifndef OPENVPN_COMMON_CIRC_LIST_H
#define OPENVPN_COMMON_CIRC_LIST_H
#include <vector>
#include <openvpn/common/size.hpp>
#include <openvpn/common/exception.hpp>
namespace openvpn {
template <typename T>
class CircList
{
public:
OPENVPN_SIMPLE_EXCEPTION(circ_list_reset);
OPENVPN_SIMPLE_EXCEPTION(circ_list_index);
OPENVPN_SIMPLE_EXCEPTION(circ_list_const_index);
OPENVPN_SIMPLE_EXCEPTION(circ_list_push);
CircList()
{
init(0);
}
explicit CircList(const size_t capacity)
{
init(capacity);
}
void init(const size_t capacity)
{
if (capacity)
{
data_.reserve(capacity);
capacity_ = capacity;
reset();
}
else
{
head_ = capacity_ = 0;
data_.clear();
}
}
void reset()
{
if (capacity_)
{
head_ = capacity_ - 1;
data_.clear();
}
else
throw circ_list_reset();
}
size_t size() const
{
return data_.size();
}
bool defined() const
{
return capacity_ > 0;
}
void push(const T &item)
{
if (++head_ >= capacity_)
head_ = 0;
if (head_ < data_.size())
data_[head_] = item;
else if (head_ == data_.size() && data_.size() < capacity_)
data_.push_back(item);
else
throw circ_list_push(); // could occur if object isn't properly initialized
}
T &operator[](const size_t index)
{
if (index >= data_.size())
throw circ_list_index();
else if (index <= head_)
return data_[head_ - index];
else
return data_[head_ + capacity_ - index];
}
const T &operator[](const size_t index) const
{
if (index >= data_.size())
throw circ_list_const_index();
else if (index <= head_)
return data_[head_ - index];
else
return data_[head_ + capacity_ - index];
}
private:
size_t capacity_;
size_t head_;
std::vector<T> data_;
};
} // namespace openvpn
#endif // OPENVPN_COMMON_CIRC_LIST_H
|
