NDN Interest packet. More...

#include <ndn/interest.hpp>

Public Member Functions
	Interest ()=default
	Default constructor.

	Interest (const Name &name)
	Create an Interest with a specified Name.

Encoding
Error	encode (uint8_t *buf, size_t bufSize, size_t &encodedLen) const
	Encode the Interest to TLV wire format.

Name field
const Name &	name () const
	Get the Name (const reference)

Name &	name ()
	Get the Name (reference)

Interest &	setName (const Name &name)
	Set the Name (supports method chaining)

Error	setName (std::string_view uri)
	Set the Name from a URI string.

Nonce field
std::optional< uint32_t >	nonce () const
	Get the Nonce.

Interest &	setNonce (uint32_t nonce)
	Set the Nonce.

Interest &	generateNonce ()
	Generate and set a random Nonce.

InterestLifetime field
uint32_t	lifetime () const
	Get the InterestLifetime.

Interest &	setLifetime (uint32_t lifetimeMs)
	Set the InterestLifetime.

HopLimit field
std::optional< uint8_t >	hopLimit () const
	Get the HopLimit.

Interest &	setHopLimit (uint8_t limit)
	Set the HopLimit.

Interest &	decrementHopLimit ()
	Decrement the HopLimit by 1.

CanBePrefix field
bool	canBePrefix () const
	Get the CanBePrefix flag.

Interest &	setCanBePrefix (bool canBePrefix)
	Set the CanBePrefix flag.

MustBeFresh field
bool	mustBeFresh () const
	Get the MustBeFresh flag.

Interest &	setMustBeFresh (bool mustBeFresh)
	Set the MustBeFresh flag.

ForwardingHint field
Error	addForwardingHint (const Name &name)
	Add a ForwardingHint.

Error	addForwardingHint (std::string_view uri)
	Add a ForwardingHint from a URI string.

size_t	forwardingHintCount () const
	Get the number of ForwardingHints.

const Name *	forwardingHint (size_t index) const
	Get a ForwardingHint by index.

void	clearForwardingHints ()
	Clear all ForwardingHints.

bool	hasForwardingHint () const
	Check if ForwardingHints are set.

ApplicationParameters field
const uint8_t *	applicationParameters () const
	Get the ApplicationParameters.

size_t	applicationParametersSize () const
	Get the size of ApplicationParameters.

Interest &	setApplicationParameters (const uint8_t *params, size_t len)
	Set ApplicationParameters.

Signature fields
bool	isSigned () const
	Check if the Interest is signed.

SignatureType	signatureType () const
	Get the signature type.

const uint8_t *	signatureNonce () const
	Get the signature nonce.

std::optional< uint64_t >	signatureTime () const
	Get the signature time.

std::optional< uint64_t >	signatureSeqNum () const
	Get the signature sequence number.

Interest &	setSignatureSeqNum (uint64_t seqNum)
	Set the signature sequence number.

const Name *	keyLocator () const
	Get the KeyLocator.

bool	hasKeyLocator () const
	Check if KeyLocator is set.

Interest &	setKeyLocator (const Name &name)
	Set the KeyLocator.

Interest &	clearKeyLocator ()
	Clear the KeyLocator.

const uint8_t *	signatureValue () const
	Get a pointer to the signature value.

size_t	signatureValueSize () const
	Get the size of the signature value.

Error	signWithDigestSha256 ()
	Sign with DigestSha256.

Error	signWithHmac (const uint8_t *key, size_t keyLen)
	Sign with HMAC-SHA256.

bool	verifyDigestSha256 () const
	Verify a DigestSha256 signature.

bool	verifyHmac (const uint8_t *key, size_t keyLen) const
	Verify an HMAC-SHA256 signature.

Error	signWithEcdsa (const uint8_t *privKey)
	Sign with ECDSA P-256.

bool	verifyEcdsa (const uint8_t *pubKey) const
	Verify an ECDSA P-256 signature.

Static Public Member Functions
Decoding
static Result< Interest >	fromWire (const uint8_t *buf, size_t len)
	Decode an Interest from TLV wire format.

Detailed Description

NDN Interest packet.

An Interest packet is sent by a consumer to request data. Only the Name field is required; all other fields are optional.

// Create and configure an Interest
ndn::Interest interest;
interest.setName("/sensor/temperature");
interest.setLifetime(5000);
interest.generateNonce();
 
// Encode
uint8_t buf[128];
size_t len = 0;
if (interest.encode(buf, sizeof(buf), len) == ndn::Error::Success) {
    // Send buf over the network
}
 
// Decode
auto result = ndn::Interest::fromWire(buf, len);
if (result.ok()) {
    printf("Interest for: %s\n", result.value.name().toUri(...));
}

Definition at line 50 of file interest.hpp.

Constructor & Destructor Documentation

◆ Interest() [1/2]

ndn::Interest::Interest ( )

default

Default constructor.

Creates an empty Interest. Name is empty, Nonce is unset, and lifetime is set to the default value (4000ms).

◆ Interest() [2/2]

ndn::Interest::Interest ( const Name & name )

explicit

Create an Interest with a specified Name.

Parameters

name	The Interest name

Definition at line 11 of file interest.cpp.

Member Function Documentation

◆ addForwardingHint() [1/2]

Error ndn::Interest::addForwardingHint ( const Name & name )

Add a ForwardingHint.

ForwardingHint is a list of Names indicating routes to the producer. Delegations obtained from a Link Object can be set here.

Parameters

name	Name to add

Returns: Error::Success on success, Error::Full when at capacity

Definition at line 64 of file interest.cpp.

References name().

Referenced by addForwardingHint().

◆ addForwardingHint() [2/2]

Error ndn::Interest::addForwardingHint ( std::string_view uri )

Add a ForwardingHint from a URI string.

Parameters

uri	URI string

Returns: Error::Success on success

Definition at line 72 of file interest.cpp.

References addForwardingHint(), and ndn::Name::fromUri().

◆ applicationParameters()

const uint8_t * ndn::Interest::applicationParameters ( ) const

inline

Get the ApplicationParameters.

Returns: Pointer to the parameter data, nullptr if unset

Definition at line 307 of file interest.hpp.

◆ applicationParametersSize()

size_t ndn::Interest::applicationParametersSize ( ) const

inline

Get the size of ApplicationParameters.

Returns: Size of the parameters in bytes

Definition at line 315 of file interest.hpp.

◆ canBePrefix()

bool ndn::Interest::canBePrefix ( ) const

inline

Get the CanBePrefix flag.

When true, this Interest also accepts Data whose Name matches as a prefix.

Returns: CanBePrefix flag (default is false)

Definition at line 220 of file interest.hpp.

Referenced by setCanBePrefix().

◆ clearForwardingHints()

void ndn::Interest::clearForwardingHints ( )

Clear all ForwardingHints.

Definition at line 87 of file interest.cpp.

◆ clearKeyLocator()

Interest & ndn::Interest::clearKeyLocator ( )

Clear the KeyLocator.

Returns: Reference to this Interest

Definition at line 109 of file interest.cpp.

◆ decrementHopLimit()

Interest & ndn::Interest::decrementHopLimit ( )

Decrement the HopLimit by 1.

If HopLimit is set, decrements it by 1. If it is already 0, it remains 0.

Returns: Reference to this Interest

Definition at line 47 of file interest.cpp.

◆ encode()

Error ndn::Interest::encode	(	uint8_t *	buf,
		size_t	bufSize,
		size_t &	encodedLen
	)		const

Encode the Interest to TLV wire format.

Parameters

buf	Output buffer
bufSize	Buffer size
encodedLen	Stores the number of encoded bytes

Returns: Error::Success on success, Error::BufferTooSmall if buffer is insufficient

Definition at line 350 of file interest.cpp.

References ndn::tlv::ApplicationParameters, ndn::tlv::CanBePrefix, ndn::TlvEncoder::current(), ndn::Name::encode(), ndn::tlv::ForwardingHint, ndn::tlv::HopLimit, ndn::tlv::Interest, ndn::INTEREST_DEFAULT_LIFETIME_MS, ndn::tlv::InterestLifetime, ndn::tlv::InterestSignatureValue, ndn::tlv::MustBeFresh, ndn::tlv::Nonce, ndn::PACKET_MAX_SIZE, ndn::TlvEncoder::position(), ndn::TlvEncoder::remaining(), ndn::TlvEncoder::setPosition(), ndn::TlvEncoder::size(), ndn::varNumberSize(), ndn::TlvEncoder::writeBytes(), ndn::TlvEncoder::writeLength(), ndn::TlvEncoder::writeTlv(), ndn::TlvEncoder::writeTlvNonNegativeInteger(), and ndn::TlvEncoder::writeType().

◆ forwardingHint()

const Name * ndn::Interest::forwardingHint ( size_t index ) const

Get a ForwardingHint by index.

Parameters

index Index (starting from 0)

Returns: Pointer to the Name at the given index, nullptr if out of range

Definition at line 80 of file interest.cpp.

◆ forwardingHintCount()

size_t ndn::Interest::forwardingHintCount ( ) const

inline

Get the number of ForwardingHints.

Returns: Number of ForwardingHints

Definition at line 278 of file interest.hpp.

◆ fromWire()

Result< Interest > ndn::Interest::fromWire	(	const uint8_t *	buf,
		size_t	len
	)

static

Decode an Interest from TLV wire format.

Parameters

buf	Input buffer
len	Buffer length

Returns: Interest and Error::Success on success, Error::InvalidPacket if TLV Type is not 0x05, Error::InvalidPacket if Name is missing

Definition at line 580 of file interest.cpp.

References ndn::tlv::ApplicationParameters, ndn::tlv::CanBePrefix, ndn::TlvDecoder::current(), ndn::tlv::ForwardingHint, ndn::Name::fromWire(), ndn::tlv::HopLimit, ndn::tlv::Interest, ndn::tlv::InterestLifetime, ndn::tlv::InterestSignatureInfo, ndn::tlv::InterestSignatureValue, ndn::tlv::MustBeFresh, ndn::tlv::Name, ndn::tlv::Nonce, ndn::TlvDecoder::position(), ndn::TlvDecoder::readBytes(), ndn::TlvDecoder::readNonNegativeInteger(), ndn::TlvDecoder::readTlvHeader(), ndn::TlvDecoder::remaining(), ndn::TlvDecoder::setPosition(), ndn::SIGNATURE_MAX_SIZE, and ndn::TlvDecoder::skip().

◆ generateNonce()

Interest & ndn::Interest::generateNonce ( )

Generate and set a random Nonce.

Returns: Reference to this Interest

Definition at line 32 of file interest.cpp.

References ndn::generateRandomNonce().

◆ hasForwardingHint()

bool ndn::Interest::hasForwardingHint ( ) const

inline

Check if ForwardingHints are set.

Returns: true if ForwardingHints are present

Definition at line 296 of file interest.hpp.

◆ hasKeyLocator()

bool ndn::Interest::hasKeyLocator ( ) const

inline

Check if KeyLocator is set.

Returns: true if KeyLocator is present

Definition at line 391 of file interest.hpp.

◆ hopLimit()

std::optional< uint8_t > ndn::Interest::hopLimit ( ) const

inline

Get the HopLimit.

HopLimit is the maximum number of hops an Interest can traverse. It decreases by 1 at each hop and is not forwarded when it reaches 0.

Returns: HopLimit value (0-255) if set, nullopt if unset

Definition at line 189 of file interest.hpp.

◆ isSigned()

bool ndn::Interest::isSigned ( ) const

inline

Check if the Interest is signed.

Returns: true if a signature is present

Definition at line 337 of file interest.hpp.

◆ keyLocator()

const Name * ndn::Interest::keyLocator ( ) const

inline

Get the KeyLocator.

Returns the reference information (Name) of the key used for signing.

Returns: KeyLocator Name if set, nullptr if unset

Definition at line 385 of file interest.hpp.

◆ lifetime()

uint32_t ndn::Interest::lifetime ( ) const

inline

Get the InterestLifetime.

Returns the Interest's lifetime in milliseconds. Default value is 4000ms (INTEREST_DEFAULT_LIFETIME_MS).

Returns: InterestLifetime (milliseconds)

Definition at line 167 of file interest.hpp.

Referenced by ndn::Pit::insert().

◆ mustBeFresh()

bool ndn::Interest::mustBeFresh ( ) const

inline

Get the MustBeFresh flag.

When true, Data returned from the Content Store must be fresh (within its FreshnessPeriod).

Returns: MustBeFresh flag (default is false)

Definition at line 242 of file interest.hpp.

Referenced by setMustBeFresh().

◆ name() [1/2]

Name & ndn::Interest::name ( )

inline

Get the Name (reference)

Returns: Reference to the Name

Definition at line 111 of file interest.hpp.

◆ name() [2/2]

const Name & ndn::Interest::name ( ) const

inline

Get the Name (const reference)

Returns: Const reference to the Name

Definition at line 105 of file interest.hpp.

Referenced by addForwardingHint(), ndn::Pit::insert(), setKeyLocator(), and setName().

◆ nonce()

std::optional< uint32_t > ndn::Interest::nonce ( ) const

inline

Get the Nonce.

The Nonce is a 32-bit random value used for loop detection.

Returns: Nonce value if set, nullopt if unset

Definition at line 139 of file interest.hpp.

Referenced by ndn::Pit::insert(), and setNonce().

◆ setApplicationParameters()

Interest & ndn::Interest::setApplicationParameters	(	const uint8_t *	params,
		size_t	len
	)

Set ApplicationParameters.

Data is copied to an internal buffer.

Parameters

params	Pointer to the parameter data
len	Size of the parameters in bytes

Returns: Reference to this Interest

Definition at line 91 of file interest.cpp.

◆ setCanBePrefix()

Interest & ndn::Interest::setCanBePrefix ( bool canBePrefix )

Set the CanBePrefix flag.

Parameters

canBePrefix true to allow prefix matching

Returns: Reference to this Interest

Definition at line 54 of file interest.cpp.

References canBePrefix().

◆ setHopLimit()

Interest & ndn::Interest::setHopLimit ( uint8_t limit )

Set the HopLimit.

Parameters

limit HopLimit value (0-255)

Returns: Reference to this Interest

Definition at line 42 of file interest.cpp.

◆ setKeyLocator()

Interest & ndn::Interest::setKeyLocator ( const Name & name )

Set the KeyLocator.

Parameters

name	Name identifying the key

Returns: Reference to this Interest

Definition at line 103 of file interest.cpp.

References name().

◆ setLifetime()

Interest & ndn::Interest::setLifetime ( uint32_t lifetimeMs )

Set the InterestLifetime.

Parameters

lifetimeMs Lifetime (milliseconds)

Returns: Reference to this Interest

Definition at line 37 of file interest.cpp.

◆ setMustBeFresh()

Interest & ndn::Interest::setMustBeFresh ( bool mustBeFresh )

Set the MustBeFresh flag.

Parameters

mustBeFresh true to accept only fresh Data

Returns: Reference to this Interest

Definition at line 59 of file interest.cpp.

References mustBeFresh().

◆ setName() [1/2]

Interest & ndn::Interest::setName ( const Name & name )

Set the Name (supports method chaining)

Parameters

name	Name to set

Returns: Reference to this Interest

Definition at line 13 of file interest.cpp.

References name().

◆ setName() [2/2]

Error ndn::Interest::setName ( std::string_view uri )

Set the Name from a URI string.

Parameters

uri	URI string (e.g., "/sensor/temperature")

Returns: Error::Success on success, error code on parse failure

Definition at line 18 of file interest.cpp.

References ndn::Name::fromUri().

◆ setNonce()

Interest & ndn::Interest::setNonce ( uint32_t nonce )

Set the Nonce.

Parameters

nonce Nonce value to set

Returns: Reference to this Interest

Definition at line 27 of file interest.cpp.

References nonce().

◆ setSignatureSeqNum()

Interest & ndn::Interest::setSignatureSeqNum ( uint64_t seqNum )

Set the signature sequence number.

Parameters

seqNum Sequence number

Returns: Reference to this Interest

Definition at line 98 of file interest.cpp.

◆ signatureNonce()

const uint8_t * ndn::Interest::signatureNonce ( ) const

inline

Get the signature nonce.

A random value for replay attack prevention.

Returns: Pointer to the signature nonce (8 bytes), nullptr if unset

Definition at line 352 of file interest.hpp.

◆ signatureSeqNum()

std::optional< uint64_t > ndn::Interest::signatureSeqNum ( ) const

inline

Get the signature sequence number.

A sequence number for replay attack prevention. Can be used in combination with SignatureNonce and SignatureTime.

Returns: Sequence number if set, nullopt if unset

Definition at line 369 of file interest.hpp.

◆ signatureTime()

std::optional< uint64_t > ndn::Interest::signatureTime ( ) const

inline

Get the signature time.

Returns: Signature time (milliseconds Unix epoch) if set, nullopt if unset

Definition at line 359 of file interest.hpp.

◆ signatureType()

SignatureType ndn::Interest::signatureType ( ) const

inline

Get the signature type.

Returns: Signature type

Definition at line 343 of file interest.hpp.

◆ signatureValue()

const uint8_t * ndn::Interest::signatureValue ( ) const

inline

Get a pointer to the signature value.

Returns: Pointer to the signature value buffer

Definition at line 410 of file interest.hpp.

◆ signatureValueSize()

size_t ndn::Interest::signatureValueSize ( ) const

inline

Get the size of the signature value.

Returns: Size of the signature value in bytes

Definition at line 416 of file interest.hpp.

◆ signWithDigestSha256()

Error ndn::Interest::signWithDigestSha256 ( )

Sign with DigestSha256.

Computes a SHA-256 digest from the TLV starting at ApplicationParameters, and stores it in InterestSignatureValue.

Returns: Error::Success on success

Definition at line 196 of file interest.cpp.

References ndn::currentTimeMs(), ndn::PACKET_MAX_SIZE, and ndn::SHA256_DIGEST_SIZE.

◆ signWithEcdsa()

Error ndn::Interest::signWithEcdsa ( const uint8_t * privKey )

Sign with ECDSA P-256.

Computes an ECDSA signature using the specified private key and stores it in InterestSignatureValue. It is recommended to set the KeyLocator beforehand.

Parameters

privKey Private key (32 bytes)

Returns: Error::Success on success

Definition at line 303 of file interest.cpp.

References ndn::currentTimeMs(), and ndn::PACKET_MAX_SIZE.

◆ signWithHmac()

Error ndn::Interest::signWithHmac	(	const uint8_t *	key,
		size_t	keyLen
	)

Sign with HMAC-SHA256.

Computes HMAC-SHA256 using the specified key and stores it in InterestSignatureValue.

Parameters

key	Pointer to the key data
keyLen	Key length (bytes)

Returns: Error::Success on success

Definition at line 219 of file interest.cpp.

References ndn::currentTimeMs(), ndn::HMAC_SHA256_SIZE, and ndn::PACKET_MAX_SIZE.

◆ verifyDigestSha256()

bool ndn::Interest::verifyDigestSha256 ( ) const

Verify a DigestSha256 signature.

Returns: true if the signature is valid

Definition at line 246 of file interest.cpp.

References ndn::PACKET_MAX_SIZE, and ndn::SHA256_DIGEST_SIZE.

◆ verifyEcdsa()

bool ndn::Interest::verifyEcdsa ( const uint8_t * pubKey ) const

Verify an ECDSA P-256 signature.

Parameters

pubKey Public key (65 bytes, uncompressed form)

Returns: true if the signature is valid

Definition at line 326 of file interest.cpp.

References ndn::ECDSA_P256_SIG_MAX_SIZE, and ndn::PACKET_MAX_SIZE.

◆ verifyHmac()

bool ndn::Interest::verifyHmac	(	const uint8_t *	key,
		size_t	keyLen
	)		const

Verify an HMAC-SHA256 signature.

Parameters

key	Pointer to the key data
keyLen	Key length (bytes)

Returns: true if the signature is valid

Definition at line 273 of file interest.cpp.

References ndn::HMAC_SHA256_SIZE, and ndn::PACKET_MAX_SIZE.

The documentation for this class was generated from the following files:

include/ndn/interest.hpp
src/interest.cpp

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ Interest() [1/2]

◆ Interest() [2/2]

Member Function Documentation

◆ addForwardingHint() [1/2]

◆ addForwardingHint() [2/2]

◆ applicationParameters()

◆ applicationParametersSize()

◆ canBePrefix()

◆ clearForwardingHints()

◆ clearKeyLocator()

◆ decrementHopLimit()

◆ encode()

◆ forwardingHint()

◆ forwardingHintCount()

◆ fromWire()

◆ generateNonce()

◆ hasForwardingHint()

◆ hasKeyLocator()

◆ hopLimit()

◆ isSigned()

◆ keyLocator()

◆ lifetime()

◆ mustBeFresh()

◆ name() [1/2]

◆ name() [2/2]

◆ nonce()

◆ setApplicationParameters()

◆ setCanBePrefix()

◆ setHopLimit()

◆ setKeyLocator()

◆ setLifetime()

◆ setMustBeFresh()

◆ setName() [1/2]

◆ setName() [2/2]

◆ setNonce()

◆ setSignatureSeqNum()

◆ signatureNonce()

◆ signatureSeqNum()

◆ signatureTime()

◆ signatureType()

◆ signatureValue()

◆ signatureValueSize()

◆ signWithDigestSha256()

◆ signWithEcdsa()

◆ signWithHmac()

◆ verifyDigestSha256()

◆ verifyEcdsa()

◆ verifyHmac()