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
130
|
// Copyright (C) 2016-2022 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
#ifndef OPTION6_PDEXCLUDE_H
#define OPTION6_PDEXCLUDE_H
#include <asiolink/io_address.h>
#include <dhcp/option.h>
#include <boost/shared_ptr.hpp>
#include <stdint.h>
namespace isc {
namespace dhcp {
/// @brief DHCPv6 option class representing Prefix Exclude Option (RFC 6603).
///
/// This class represents DHCPv6 Prefix Exclude option (67). This option is
/// carried in the IA Prefix option and it conveys a single prefix which is
/// used by the delegating router to communicate with a requesting router on
/// the requesting router's uplink. This prefix is not used on the
/// requesting router's downlinks (is excluded from other delegated prefixes).
class Option6PDExclude: public Option {
public:
/// @brief Constructor.
///
/// @param delegated_prefix Delegated prefix.
/// @param delegated_prefix_length Delegated prefix length.
/// @param excluded_prefix Excluded prefix.
/// @param excluded_prefix_length Excluded prefix length.
///
/// @throw BadValue if prefixes are invalid, if excluded prefix length
/// is not greater than delegated prefix length or if common parts of
/// prefixes does not match.
Option6PDExclude(const isc::asiolink::IOAddress& delegated_prefix,
const uint8_t delegated_prefix_length,
const isc::asiolink::IOAddress& excluded_prefix,
const uint8_t excluded_prefix_length);
/// @brief Constructor, creates option instance from part of the buffer.
///
/// This constructor is mostly used to parse Prefix Exclude options in the
/// received messages.
///
/// @param begin Lower bound of the buffer to create option from.
/// @param end Upper bound of the buffer to create option from.
Option6PDExclude(OptionBufferConstIter begin, OptionBufferConstIter end);
/// @brief Copies this option and returns a pointer to the copy.
virtual OptionPtr clone() const;
/// @brief Writes option in wire-format to a buffer.
///
/// Writes option in wire-format to buffer, returns pointer to first unused
/// byte after stored option (that is useful for writing options one after
/// another).
///
/// The format of the option includes excluded prefix length specified as
/// a number of bits. It also includes IPv6 subnet ID field which is
/// computed from the delegated and excluded prefixes, according to the
/// section 4.2 of RFC 6603.
///
/// @param [out] buf Pointer to a buffer.
/// @param check if set to false, allows options larger than 255 for v4
virtual void pack(isc::util::OutputBuffer& buf, bool check = true) const;
/// @brief Parses received buffer.
///
/// @param begin iterator to first byte of option data
/// @param end iterator to end of option data (first byte after option end)
virtual void unpack(OptionBufferConstIter begin, OptionBufferConstIter end);
/// @brief Returns length of the complete option (data length + DHCPv6
/// option header)
///
/// @return length of the option
virtual uint16_t len() const;
/// @brief Returns Prefix Exclude option in textual format.
///
/// @param indent Number of spaces to be inserted before the text.
virtual std::string toText(int indent = 0) const;
/// @brief Returns excluded prefix.
///
/// Assembles excluded prefix from a delegated prefix and IPv6 subnet id
/// specified as in RFC6603, section 4.2.
///
/// @param delegated_prefix Delegated prefix for which excluded prefix will
/// be returned.
/// @param delegated_prefix_length Delegated prefix length.
asiolink::IOAddress
getExcludedPrefix(const asiolink::IOAddress& delegated_prefix,
const uint8_t delegated_prefix_length) const;
/// @brief Returns excluded prefix length.
uint8_t getExcludedPrefixLength() const {
return (excluded_prefix_length_);
}
/// @brief Returns an excluded prefix in a binary format.
const std::vector<uint8_t>& getExcludedPrefixSubnetID() const {
return (subnet_id_);
}
private:
/// @brief Returns IPv6 subnet ID length in octets.
///
/// The IPv6 subnet ID length is between 1 and 16 octets.
uint8_t getSubnetIDLength(const uint8_t delegated_prefix_length,
const uint8_t excluded_prefix_length) const;
/// @brief Holds excluded prefix length.
uint8_t excluded_prefix_length_;
/// @brief Subnet identifier as described in RFC6603, section 4.2.
std::vector<uint8_t> subnet_id_;
};
/// @brief Pointer to the @ref Option6PDExclude object.
typedef boost::shared_ptr<Option6PDExclude> Option6PDExcludePtr;
} // isc::dhcp namespace
} // isc namespace
#endif // OPTION6_PDEXCLUDE_H
|
