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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2013-2018 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.
*/
#include "interest.hpp"
#include "util/random.hpp"
#include "data.hpp"
#include <cstring>
#include <sstream>
namespace ndn {
BOOST_CONCEPT_ASSERT((boost::EqualityComparable<Interest>));
BOOST_CONCEPT_ASSERT((WireEncodable<Interest>));
BOOST_CONCEPT_ASSERT((WireEncodableWithEncodingBuffer<Interest>));
BOOST_CONCEPT_ASSERT((WireDecodable<Interest>));
static_assert(std::is_base_of<tlv::Error, Interest::Error>::value,
"Interest::Error must inherit from tlv::Error");
Interest::Interest(const Name& name, time::milliseconds lifetime)
: m_name(name)
, m_interestLifetime(lifetime)
{
if (lifetime < time::milliseconds::zero()) {
BOOST_THROW_EXCEPTION(std::invalid_argument("InterestLifetime must be >= 0"));
}
}
Interest::Interest(const Block& wire)
{
wireDecode(wire);
}
// ---- encode and decode ----
template<encoding::Tag TAG>
size_t
Interest::wireEncode(EncodingImpl<TAG>& encoder) const
{
size_t totalLength = 0;
// Interest ::= INTEREST-TYPE TLV-LENGTH
// Name
// Selectors?
// Nonce
// InterestLifetime?
// ForwardingHint?
// (reverse encoding)
// ForwardingHint
if (m_forwardingHint.size() > 0) {
totalLength += m_forwardingHint.wireEncode(encoder);
}
// InterestLifetime
if (getInterestLifetime() != DEFAULT_INTEREST_LIFETIME) {
totalLength += prependNonNegativeIntegerBlock(encoder,
tlv::InterestLifetime,
getInterestLifetime().count());
}
// Nonce
uint32_t nonce = this->getNonce(); // assigns random Nonce if needed
totalLength += encoder.prependByteArray(reinterpret_cast<uint8_t*>(&nonce), sizeof(nonce));
totalLength += encoder.prependVarNumber(sizeof(nonce));
totalLength += encoder.prependVarNumber(tlv::Nonce);
// Selectors
if (hasSelectors()) {
totalLength += getSelectors().wireEncode(encoder);
}
// Name
totalLength += getName().wireEncode(encoder);
totalLength += encoder.prependVarNumber(totalLength);
totalLength += encoder.prependVarNumber(tlv::Interest);
return totalLength;
}
NDN_CXX_DEFINE_WIRE_ENCODE_INSTANTIATIONS(Interest);
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);
const_cast<Interest*>(this)->wireDecode(buffer.block());
return m_wire;
}
void
Interest::wireDecode(const Block& wire)
{
m_wire = wire;
m_wire.parse();
if (m_wire.type() != tlv::Interest) {
BOOST_THROW_EXCEPTION(Error("expecting Interest element, got " + to_string(m_wire.type())));
}
if (!decode02()) {
decode03();
if (!hasNonce()) {
setNonce(getNonce());
}
}
}
bool
Interest::decode02()
{
auto ele = m_wire.elements_begin();
// Name
if (ele != m_wire.elements_end() && ele->type() == tlv::Name) {
m_name.wireDecode(*ele);
++ele;
}
else {
return false;
}
// Selectors?
if (ele != m_wire.elements_end() && ele->type() == tlv::Selectors) {
m_selectors.wireDecode(*ele);
++ele;
}
else {
m_selectors = Selectors();
}
// Nonce
if (ele != m_wire.elements_end() && ele->type() == tlv::Nonce) {
uint32_t nonce = 0;
if (ele->value_size() != sizeof(nonce)) {
BOOST_THROW_EXCEPTION(Error("Nonce element is malformed"));
}
std::memcpy(&nonce, ele->value(), sizeof(nonce));
m_nonce = nonce;
++ele;
}
else {
return false;
}
// InterestLifetime?
if (ele != m_wire.elements_end() && ele->type() == tlv::InterestLifetime) {
m_interestLifetime = time::milliseconds(readNonNegativeInteger(*ele));
++ele;
}
else {
m_interestLifetime = DEFAULT_INTEREST_LIFETIME;
}
// ForwardingHint?
if (ele != m_wire.elements_end() && ele->type() == tlv::ForwardingHint) {
m_forwardingHint.wireDecode(*ele, false);
++ele;
}
else {
m_forwardingHint = DelegationList();
}
return ele == m_wire.elements_end();
}
void
Interest::decode03()
{
// Interest ::= INTEREST-TYPE TLV-LENGTH
// Name
// CanBePrefix?
// MustBeFresh?
// ForwardingHint?
// Nonce?
// InterestLifetime?
// HopLimit?
// Parameters?
bool hasName = false;
m_selectors = Selectors().setMaxSuffixComponents(1); // CanBePrefix=0
m_nonce.reset();
m_interestLifetime = DEFAULT_INTEREST_LIFETIME;
m_forwardingHint = DelegationList();
int lastEle = 0; // last recognized element index, in spec order
for (const Block& ele : m_wire.elements()) {
switch (ele.type()) {
case tlv::Name: {
if (lastEle >= 1) {
BOOST_THROW_EXCEPTION(Error("Name element is out of order"));
}
hasName = true;
m_name.wireDecode(ele);
if (m_name.empty()) {
BOOST_THROW_EXCEPTION(Error("Name has zero name components"));
}
lastEle = 1;
break;
}
case tlv::CanBePrefix: {
if (lastEle >= 2) {
BOOST_THROW_EXCEPTION(Error("CanBePrefix element is out of order"));
}
if (ele.value_size() != 0) {
BOOST_THROW_EXCEPTION(Error("CanBePrefix element has non-zero TLV-LENGTH"));
}
m_selectors.setMaxSuffixComponents(-1);
lastEle = 2;
break;
}
case tlv::MustBeFresh: {
if (lastEle >= 3) {
BOOST_THROW_EXCEPTION(Error("MustBeFresh element is out of order"));
}
if (ele.value_size() != 0) {
BOOST_THROW_EXCEPTION(Error("MustBeFresh element has non-zero TLV-LENGTH"));
}
m_selectors.setMustBeFresh(true);
lastEle = 3;
break;
}
case tlv::ForwardingHint: {
if (lastEle >= 4) {
BOOST_THROW_EXCEPTION(Error("ForwardingHint element is out of order"));
}
m_forwardingHint.wireDecode(ele);
lastEle = 4;
break;
}
case tlv::Nonce: {
if (lastEle >= 5) {
BOOST_THROW_EXCEPTION(Error("Nonce element is out of order"));
}
uint32_t nonce = 0;
if (ele.value_size() != sizeof(nonce)) {
BOOST_THROW_EXCEPTION(Error("Nonce element is malformed"));
}
std::memcpy(&nonce, ele.value(), sizeof(nonce));
m_nonce = nonce;
lastEle = 5;
break;
}
case tlv::InterestLifetime: {
if (lastEle >= 6) {
BOOST_THROW_EXCEPTION(Error("InterestLifetime element is out of order"));
}
m_interestLifetime = time::milliseconds(readNonNegativeInteger(ele));
lastEle = 6;
break;
}
case tlv::HopLimit: {
if (lastEle >= 7) {
break; // HopLimit is non-critical, ignore out-of-order appearance
}
if (ele.value_size() != 1) {
BOOST_THROW_EXCEPTION(Error("HopLimit element is malformed"));
}
// TLV-VALUE is ignored
lastEle = 7;
break;
}
case tlv::Parameters: {
if (lastEle >= 8) {
BOOST_THROW_EXCEPTION(Error("Parameters element is out of order"));
}
// TLV-VALUE is ignored
lastEle = 8;
break;
}
default: {
if (tlv::isCriticalType(ele.type())) {
BOOST_THROW_EXCEPTION(Error("unrecognized element of critical type " +
to_string(ele.type())));
}
break;
}
}
}
if (!hasName) {
BOOST_THROW_EXCEPTION(Error("Name element is missing"));
}
}
std::string
Interest::toUri() const
{
std::ostringstream os;
os << *this;
return os.str();
}
// ---- matching ----
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. "<GenericNameComponent>AA</GenericNameComponent><Any/>" doesn't exclude
// any digest - fullName not needed;
// "<Any/><GenericNameComponent>AA</GenericNameComponent>" and
// "<Any/><ImplicitSha256DigestComponent>ffffffffffffffffffffffffffffffff
// </ImplicitSha256DigestComponent>"
// excludes all digests - fullName not needed;
// "<Any/><ImplicitSha256DigestComponent>80000000000000000000000000000000
// </ImplicitSha256DigestComponent>"
// excludes some 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 matter 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;
}
bool
Interest::matchesInterest(const Interest& other) const
{
/// @todo #3162 match ForwardingHint field
return (this->getName() == other.getName() &&
this->getSelectors() == other.getSelectors());
}
// ---- field accessors ----
uint32_t
Interest::getNonce() const
{
if (!m_nonce) {
m_nonce = random::generateWord32();
}
return *m_nonce;
}
Interest&
Interest::setNonce(uint32_t nonce)
{
m_nonce = 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);
}
Interest&
Interest::setInterestLifetime(time::milliseconds lifetime)
{
if (lifetime < time::milliseconds::zero()) {
BOOST_THROW_EXCEPTION(std::invalid_argument("InterestLifetime must be >= 0"));
}
m_interestLifetime = lifetime;
m_wire.reset();
return *this;
}
Interest&
Interest::setForwardingHint(const DelegationList& value)
{
m_forwardingHint = value;
m_wire.reset();
return *this;
}
// ---- operators ----
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() != DEFAULT_CHILD_SELECTOR) {
os << delim << "ndn.ChildSelector=" << interest.getChildSelector();
delim = '&';
}
if (interest.getMustBeFresh()) {
os << delim << "ndn.MustBeFresh=" << interest.getMustBeFresh();
delim = '&';
}
if (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;
}
} // namespace ndn