Kea 2.5.9
option6_iaprefix.cc
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1// Copyright (C) 2013-2024 Internet Systems Consortium, Inc. ("ISC")
2//
3// This Source Code Form is subject to the terms of the Mozilla Public
4// License, v. 2.0. If a copy of the MPL was not distributed with this
5// file, You can obtain one at http://mozilla.org/MPL/2.0/.
6
7#include <config.h>
8
10#include <dhcp/dhcp6.h>
11#include <dhcp/libdhcp++.h>
13#include <dhcp/option_space.h>
15#include <util/io.h>
16
17#include <sstream>
18
19#include <stdint.h>
20#include <arpa/inet.h>
21
22using namespace std;
23using namespace isc::asiolink;
24using namespace isc::util;
25
26namespace isc {
27namespace dhcp {
28
30 uint8_t prefix_len, uint32_t pref, uint32_t valid)
31 :Option6IAAddr(type, prefix, pref, valid), prefix_len_(prefix_len) {
33 // Option6IAAddr will check if prefix is IPv6 and will throw if it is not
34 if (prefix_len > 128) {
35 isc_throw(BadValue, static_cast<unsigned>(prefix_len)
36 << " is not a valid prefix length. "
37 << "Allowed range is 0..128");
38 }
39}
40
41Option6IAPrefix::Option6IAPrefix(uint32_t type, OptionBuffer::const_iterator begin,
42 OptionBuffer::const_iterator end)
43 :Option6IAAddr(type, begin, end) {
45 unpack(begin, end);
46}
47
50 return (cloneInternal<Option6IAPrefix>());
51}
52
54 if (!addr_.isV6()) {
55 isc_throw(isc::BadValue, addr_ << " is not an IPv6 address");
56 }
57
58 buf.writeUint16(type_);
59
60 // len() returns complete option length. len field contains
61 // length without 4-byte option header
62 buf.writeUint16(len() - getHeaderLen());
63
66 buf.writeUint8(prefix_len_);
67
68 buf.writeData(&addr_.toBytes()[0], isc::asiolink::V6ADDRESS_LEN);
69
70 // store encapsulated options (the only defined so far is PD_EXCLUDE)
71 packOptions(buf);
72}
73
74void Option6IAPrefix::unpack(OptionBuffer::const_iterator begin,
75 OptionBuffer::const_iterator end) {
76 if ( distance(begin, end) < OPTION6_IAPREFIX_LEN) {
77 isc_throw(OutOfRange, "Option " << type_ << " truncated");
78 }
79
80 preferred_ = readUint32(&(*begin), distance(begin, end));
81 begin += sizeof(uint32_t);
82
83 valid_ = readUint32(&(*begin), distance(begin, end));
84 begin += sizeof(uint32_t);
85
86 prefix_len_ = *begin;
87 begin += sizeof(uint8_t);
88
89 // 16 bytes: IPv6 address
90 OptionBuffer address_with_mask;
91 mask(begin, begin + V6ADDRESS_LEN, prefix_len_, address_with_mask);
92 addr_ = IOAddress::fromBytes(AF_INET6, &(*address_with_mask.begin()));
93 begin += V6ADDRESS_LEN;
94
95 // unpack encapsulated options (the only defined so far is PD_EXCLUDE)
96 unpackOptions(OptionBuffer(begin, end));
97}
98
99std::string Option6IAPrefix::toText(int indent) const {
100 std::stringstream output;
101 output << headerToText(indent, "IAPREFIX") << ": "
102 << "prefix=" << addr_ << "/" << static_cast<int>(prefix_len_)
103 << ", preferred-lft=" << preferred_
104 << ", valid-lft=" << valid_;
105
106 output << suboptionsToText(indent + 2);
107 return (output.str());
108}
109
110uint16_t Option6IAPrefix::len() const {
111
112 uint16_t length = OPTION6_HDR_LEN + OPTION6_IAPREFIX_LEN;
113
114 // length of all suboptions
115 for (auto const& it : options_) {
116 length += it.second->len();
117 }
118 return (length);
119}
120
121void
122Option6IAPrefix::mask(OptionBuffer::const_iterator begin,
123 OptionBuffer::const_iterator end,
124 const uint8_t len,
125 OptionBuffer& output_address) const {
126 output_address.resize(16, 0);
127 if (len >= 128) {
128 std::copy(begin, end, output_address.begin());
129 } else if (len > 0) {
130 // All the bits that represent whole octets of the prefix are copied with
131 // no change.
132 std::copy(begin, begin + static_cast<uint8_t>(len/8), output_address.begin());
133 // The remaining significant bits of the last octet have to be left unchanged,
134 // but the remaining bits of this octet must be set to zero. The number of
135 // significant bits is calculated as a reminder from the division of the
136 // prefix length by 8 (by size of the octet). The number of bits to be set
137 // to zero is therefore calculated as: 8 - (len % 8).
138 // Next, the mask is created by shifting the 0xFF by the number of bits
139 // to be set to 0. By performing logical AND of this mask with the original
140 // value of the last octet we get the final value for the new octet.
141 output_address[len/8] = (*(begin + len/8) & (0xFF << (8 - (len % 8))));
142 }
143}
144
145
146} // end of namespace isc::dhcp
147} // end of namespace isc
A generic exception that is thrown if a parameter given to a method is considered invalid in that con...
A generic exception that is thrown if a parameter given to a method would refer to or modify out-of-r...
unsigned int valid_
contains valid-lifetime timer (in seconds)
isc::asiolink::IOAddress addr_
contains an IPv6 address
unsigned int preferred_
contains preferred-lifetime timer (in seconds)
static const size_t OPTION6_IAPREFIX_LEN
length of the fixed part of the IAPREFIX option
virtual std::string toText(int indent=0) const
Returns string representation of the option.
virtual void unpack(OptionBufferConstIter begin, OptionBufferConstIter end)
Parses received buffer.
Option6IAPrefix(uint16_t type, const isc::asiolink::IOAddress &addr, uint8_t prefix_length, uint32_t preferred, uint32_t valid)
Constructor, used for options constructed (during transmission).
virtual OptionPtr clone() const
Copies this option and returns a pointer to the copy.
virtual uint16_t len() const
returns data length (data length + DHCPv4/DHCPv6 option header)
void pack(isc::util::OutputBuffer &buf, bool check=true) const
Writes option in wire-format.
uint16_t type_
option type (0-255 for DHCPv4, 0-65535 for DHCPv6)
Definition: option.h:590
std::string headerToText(const int indent=0, const std::string &type_name="") const
Returns option header in the textual format.
Definition: option.cc:288
std::string suboptionsToText(const int indent=0) const
Returns collection of suboptions in the textual format.
Definition: option.cc:307
void setEncapsulatedSpace(const std::string &encapsulated_space)
Sets the name of the option space encapsulated by this option.
Definition: option.h:435
virtual uint16_t getHeaderLen() const
Returns length of header (2 for v4, 4 for v6)
Definition: option.cc:321
void unpackOptions(const OptionBuffer &buf)
Builds a collection of sub options from the buffer.
Definition: option.cc:155
void packOptions(isc::util::OutputBuffer &buf, bool check=true) const
Store sub options in a buffer.
Definition: option.cc:136
static const size_t OPTION6_HDR_LEN
length of any DHCPv6 option header
Definition: option.h:80
OptionCollection options_
collection for storing suboptions
Definition: option.h:596
The OutputBuffer class is a buffer abstraction for manipulating mutable data.
Definition: buffer.h:343
void writeUint8(uint8_t data)
Write an unsigned 8-bit integer into the buffer.
Definition: buffer.h:473
void writeUint16(uint16_t data)
Write an unsigned 16-bit integer in host byte order into the buffer in network byte order.
Definition: buffer.h:498
void writeData(const void *data, size_t len)
Copy an arbitrary length of data into the buffer.
Definition: buffer.h:556
void writeUint32(uint32_t data)
Write an unsigned 32-bit integer in host byte order into the buffer in network byte order.
Definition: buffer.h:528
#define isc_throw(type, stream)
A shortcut macro to insert known values into exception arguments.
std::vector< uint8_t > OptionBuffer
buffer types used in DHCP code.
Definition: option.h:24
boost::shared_ptr< Option > OptionPtr
Definition: option.h:37
uint32_t readUint32(void const *const buffer, size_t const length)
uint32_t wrapper over readUint.
Definition: io.h:82
Defines the logger used by the top-level component of kea-lfc.
#define DHCP6_OPTION_SPACE