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// Copyright (C) 2023-2024 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/.
#include <config.h>
#include <dhcp/option6_dnr.h>
using namespace isc::asiolink;
namespace isc {
namespace dhcp {
Option6Dnr::Option6Dnr(OptionBufferConstIter begin, OptionBufferConstIter end)
: Option(V6, D6O_V6_DNR), DnrInstance(V6) {
unpack(begin, end);
}
OptionPtr
Option6Dnr::clone() const {
return (cloneInternal<Option6Dnr>());
}
void
Option6Dnr::pack(util::OutputBuffer& buf, bool check) const {
packHeader(buf, check);
buf.writeUint16(service_priority_);
buf.writeUint16(adn_length_);
packAdn(buf);
if (adn_only_mode_) {
return;
}
buf.writeUint16(addr_length_);
packAddresses(buf);
packSvcParams(buf);
}
void
Option6Dnr::packAddresses(util::OutputBuffer& buf) const {
for (auto const& address : ip_addresses_) {
if (!address.isV6()) {
isc_throw(isc::BadValue, getLogPrefix()
<< address.toText() << " is not an IPv6 address");
}
buf.writeData(&address.toBytes()[0], V6ADDRESS_LEN);
}
}
void
Option6Dnr::unpack(OptionBufferConstIter begin, OptionBufferConstIter end) {
if (std::distance(begin, end) < getMinimalLength()) {
isc_throw(OutOfRange, getLogPrefix()
<< "data truncated to size " << std::distance(begin, end));
}
setData(begin, end);
// First two octets of Option data is Service Priority - this is mandatory field.
unpackServicePriority(begin);
// Next come two octets of ADN Length plus the ADN data itself (variable length).
// This is Opaque Data Tuple so let's use this class to retrieve the ADN data.
unpackAdn(begin, end);
if (begin == end) {
// ADN only mode, other fields are not included.
return;
}
adn_only_mode_ = false;
unpackAddresses(begin, end);
// SvcParams (variable length) field is last.
unpackSvcParams(begin, end);
}
std::string
Option6Dnr::toText(int indent) const {
std::ostringstream stream;
std::string in(indent, ' '); // base indentation
stream << in << "type=" << type_ << "(V6_DNR), "
<< "len=" << (len() - getHeaderLen()) << ", " << getDnrInstanceAsText();
return (stream.str());
}
uint16_t
Option6Dnr::len() const {
return (OPTION6_HDR_LEN + dnrInstanceLen());
}
void
Option6Dnr::unpackAddresses(OptionBufferConstIter& begin, OptionBufferConstIter end) {
if (std::distance(begin, end) < getAddrLengthSize()) {
isc_throw(OutOfRange, getLogPrefix() << "after"
" ADN field, there should be at least "
"2 bytes long Addr Length field");
}
// Next come two octets of Addr Length.
addr_length_ = isc::util::readUint16(&(*begin), getAddrLengthSize());
begin += getAddrLengthSize();
// It MUST be a multiple of 16.
if ((addr_length_ % V6ADDRESS_LEN) != 0) {
isc_throw(OutOfRange, getLogPrefix()
<< "Addr Len=" << addr_length_ << " is not divisible by 16");
}
// As per draft-ietf-add-dnr 3.1.8:
// If additional data is supplied (i.e. not ADN only mode),
// the option includes at least one valid IP address.
if (addr_length_ == 0) {
isc_throw(OutOfRange, getLogPrefix()
<< "Addr Len=" << addr_length_
<< " but it must contain at least one valid IP address");
}
// Check if IPv6 Address(es) field is not truncated.
if (std::distance(begin, end) < addr_length_) {
isc_throw(OutOfRange, getLogPrefix() << "Addr Len=" << addr_length_
<< " but IPv6 address(es) are truncated to len="
<< std::distance(begin, end));
}
// Let's unpack the ipv6-address(es).
auto addr_end = begin + addr_length_;
while (begin != addr_end) {
try {
ip_addresses_.push_back(IOAddress::fromBytes(AF_INET6, &(*begin)));
} catch (const Exception& ex) {
isc_throw(BadValue, getLogPrefix() << "failed to parse IPv6 address"
<< " - " << ex.what());
}
begin += V6ADDRESS_LEN;
}
}
} // namespace dhcp
} // namespace isc
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