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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/**
* Copyright (c) 2013-2014 Regents of the University of California.
*
* This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
*
* ndn-cxx 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 3 of the License, or (at your option) any later version.
*
* ndn-cxx 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 copies of the GNU General Public License and GNU Lesser
* General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
* <http://www.gnu.org/licenses/>.
*
* See AUTHORS.md for complete list of ndn-cxx authors and contributors.
*
* Based on code originally written by Jeff Thompson <jefft0@remap.ucla.edu>
*/
#include "interest.hpp"
#include "util/random.hpp"
#include "util/crypto.hpp"
#include "util/concepts.hpp"
#include "data.hpp"
namespace ndn {
BOOST_CONCEPT_ASSERT((boost::EqualityComparable<Interest>));
BOOST_CONCEPT_ASSERT((WireEncodable<Interest>));
BOOST_CONCEPT_ASSERT((WireDecodable<Interest>));
static_assert(std::is_base_of<tlv::Error, Interest::Error>::value,
"Interest::Error must inherit from tlv::Error");
uint32_t
Interest::getNonce() const
{
if (!m_nonce.hasWire())
const_cast<Interest*>(this)->setNonce(random::generateWord32());
if (m_nonce.value_size() == sizeof(uint32_t))
return *reinterpret_cast<const uint32_t*>(m_nonce.value());
else {
// for compatibility reasons. Should be removed eventually
return readNonNegativeInteger(m_nonce);
}
}
Interest&
Interest::setNonce(uint32_t nonce)
{
if (m_wire.hasWire() && m_nonce.value_size() == sizeof(uint32_t)) {
std::memcpy(const_cast<uint8_t*>(m_nonce.value()), &nonce, sizeof(nonce));
}
else {
m_nonce = dataBlock(tlv::Nonce,
reinterpret_cast<const uint8_t*>(&nonce),
sizeof(nonce));
m_wire.reset();
}
return *this;
}
void
Interest::refreshNonce()
{
if (!hasNonce())
return;
uint32_t oldNonce = getNonce();
uint32_t newNonce = oldNonce;
while (newNonce == oldNonce)
newNonce = random::generateWord32();
setNonce(newNonce);
}
bool
Interest::matchesName(const Name& name) const
{
if (name.size() < m_name.size())
return false;
if (!m_name.isPrefixOf(name))
return false;
if (getMinSuffixComponents() >= 0 &&
// name must include implicit digest
!(name.size() - m_name.size() >= static_cast<size_t>(getMinSuffixComponents())))
return false;
if (getMaxSuffixComponents() >= 0 &&
// name must include implicit digest
!(name.size() - m_name.size() <= static_cast<size_t>(getMaxSuffixComponents())))
return false;
if (!getExclude().empty() &&
name.size() > m_name.size() &&
getExclude().isExcluded(name[m_name.size()]))
return false;
return true;
}
bool
Interest::matchesData(const Data& data) const
{
size_t interestNameLength = m_name.size();
const Name& dataName = data.getName();
size_t fullNameLength = dataName.size() + 1;
// check MinSuffixComponents
bool hasMinSuffixComponents = getMinSuffixComponents() >= 0;
size_t minSuffixComponents = hasMinSuffixComponents ?
static_cast<size_t>(getMinSuffixComponents()) : 0;
if (!(interestNameLength + minSuffixComponents <= fullNameLength))
return false;
// check MaxSuffixComponents
bool hasMaxSuffixComponents = getMaxSuffixComponents() >= 0;
if (hasMaxSuffixComponents &&
!(interestNameLength + getMaxSuffixComponents() >= fullNameLength))
return false;
// check prefix
if (interestNameLength == fullNameLength) {
if (m_name.get(-1).isImplicitSha256Digest()) {
if (m_name != data.getFullName())
return false;
}
else {
// Interest Name is same length as Data full Name, but last component isn't digest
// so there's no possibility of matching
return false;
}
}
else {
// Interest Name is a strict prefix of Data full Name
if (!m_name.isPrefixOf(dataName))
return false;
}
// check Exclude
// Exclude won't be violated if Interest Name is same as Data full Name
if (!getExclude().empty() && fullNameLength > interestNameLength) {
if (interestNameLength == fullNameLength - 1) {
// component to exclude is the digest
if (getExclude().isExcluded(data.getFullName().get(interestNameLength)))
return false;
// There's opportunity to inspect the Exclude filter and determine whether
// the digest would make a difference.
// eg. "Exclude=<Any>AA" won't exclude any digest - fullName not needed
// "Exclude=ZZ<Any>" excludes all digests - fullName not needed
// "Exclude=<Any>80000000000000000000000000000000"
// excludes half of the digests - fullName required
// But Interests that contain the exact Data Name before digest and also
// contain Exclude filter is too rare to optimize for, so we request
// fullName no mater what's in the Exclude filter.
}
else {
// component to exclude is not the digest
if (getExclude().isExcluded(dataName.get(interestNameLength)))
return false;
}
}
// check PublisherPublicKeyLocator
const KeyLocator& publisherPublicKeyLocator = this->getPublisherPublicKeyLocator();
if (!publisherPublicKeyLocator.empty()) {
const Signature& signature = data.getSignature();
const Block& signatureInfo = signature.getInfo();
Block::element_const_iterator it = signatureInfo.find(tlv::KeyLocator);
if (it == signatureInfo.elements_end()) {
return false;
}
if (publisherPublicKeyLocator.wireEncode() != *it) {
return false;
}
}
return true;
}
template<bool T>
size_t
Interest::wireEncode(EncodingImpl<T>& block) const
{
size_t totalLength = 0;
// Interest ::= INTEREST-TYPE TLV-LENGTH
// Name
// Selectors?
// Nonce
// Scope?
// InterestLifetime?
// (reverse encoding)
// InterestLifetime
if (getInterestLifetime() >= time::milliseconds::zero() &&
getInterestLifetime() != DEFAULT_INTEREST_LIFETIME)
{
totalLength += prependNonNegativeIntegerBlock(block,
tlv::InterestLifetime,
getInterestLifetime().count());
}
// Scope
if (getScope() >= 0)
{
totalLength += prependNonNegativeIntegerBlock(block, tlv::Scope, getScope());
}
// Nonce
getNonce(); // to ensure that Nonce is properly set
totalLength += block.prependBlock(m_nonce);
// Selectors
if (hasSelectors())
{
totalLength += getSelectors().wireEncode(block);
}
// Name
totalLength += getName().wireEncode(block);
totalLength += block.prependVarNumber(totalLength);
totalLength += block.prependVarNumber(tlv::Interest);
return totalLength;
}
template size_t
Interest::wireEncode<true>(EncodingImpl<true>& block) const;
template size_t
Interest::wireEncode<false>(EncodingImpl<false>& block) const;
const Block&
Interest::wireEncode() const
{
if (m_wire.hasWire())
return m_wire;
EncodingEstimator estimator;
size_t estimatedSize = wireEncode(estimator);
EncodingBuffer buffer(estimatedSize, 0);
wireEncode(buffer);
// to ensure that Nonce block points to the right memory location
const_cast<Interest*>(this)->wireDecode(buffer.block());
return m_wire;
}
void
Interest::wireDecode(const Block& wire)
{
m_wire = wire;
m_wire.parse();
// Interest ::= INTEREST-TYPE TLV-LENGTH
// Name
// Selectors?
// Nonce
// Scope?
// InterestLifetime?
if (m_wire.type() != tlv::Interest)
throw Error("Unexpected TLV number when decoding Interest");
// Name
m_name.wireDecode(m_wire.get(tlv::Name));
// Selectors
Block::element_const_iterator val = m_wire.find(tlv::Selectors);
if (val != m_wire.elements_end())
{
m_selectors.wireDecode(*val);
}
else
m_selectors = Selectors();
// Nonce
m_nonce = m_wire.get(tlv::Nonce);
// Scope
val = m_wire.find(tlv::Scope);
if (val != m_wire.elements_end())
{
m_scope = readNonNegativeInteger(*val);
}
else
m_scope = -1;
// InterestLifetime
val = m_wire.find(tlv::InterestLifetime);
if (val != m_wire.elements_end())
{
m_interestLifetime = time::milliseconds(readNonNegativeInteger(*val));
}
else
{
m_interestLifetime = DEFAULT_INTEREST_LIFETIME;
}
}
std::ostream&
operator<<(std::ostream& os, const Interest& interest)
{
os << interest.getName();
char delim = '?';
if (interest.getMinSuffixComponents() >= 0) {
os << delim << "ndn.MinSuffixComponents=" << interest.getMinSuffixComponents();
delim = '&';
}
if (interest.getMaxSuffixComponents() >= 0) {
os << delim << "ndn.MaxSuffixComponents=" << interest.getMaxSuffixComponents();
delim = '&';
}
if (interest.getChildSelector() >= 0) {
os << delim << "ndn.ChildSelector=" << interest.getChildSelector();
delim = '&';
}
if (interest.getMustBeFresh()) {
os << delim << "ndn.MustBeFresh=" << interest.getMustBeFresh();
delim = '&';
}
if (interest.getScope() >= 0) {
os << delim << "ndn.Scope=" << interest.getScope();
delim = '&';
}
if (interest.getInterestLifetime() >= time::milliseconds::zero()
&& interest.getInterestLifetime() != DEFAULT_INTEREST_LIFETIME) {
os << delim << "ndn.InterestLifetime=" << interest.getInterestLifetime().count();
delim = '&';
}
if (interest.hasNonce()) {
os << delim << "ndn.Nonce=" << interest.getNonce();
delim = '&';
}
if (!interest.getExclude().empty()) {
os << delim << "ndn.Exclude=" << interest.getExclude();
delim = '&';
}
return os;
}
}