NDN Data packet. More...

#include <ndn/data.hpp>

Public Member Functions
	Data ()=default
	Default constructor.

	Data (const Name &name)
	Create a Data packet with a specified Name.

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

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

Name &	name ()
	Get the Name (reference)

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

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

Content field
const uint8_t *	content () const
	Get a pointer to the content data.

size_t	contentSize () const
	Get the content size.

bool	hasContent () const
	Check if content is set.

Error	setContent (const uint8_t *data, size_t size)
	Set binary data as content.

Error	setContent (std::string_view str)
	Set a string as content.

ContentType field
ContentType	contentType () const
	Get the content type.

Data &	setContentType (ContentType type)
	Set the content type.

bool	isLink () const
	Check if this is a Link Object.

FreshnessPeriod field
std::optional< uint32_t >	freshnessPeriod () const
	Get the FreshnessPeriod.

Data &	setFreshnessPeriod (uint32_t periodMs)
	Set the FreshnessPeriod.

FinalBlockId field
std::optional< uint64_t >	finalBlockId () const
	Get the FinalBlockId.

bool	hasFinalBlockId () const
	Check if FinalBlockId is set.

Data &	setFinalBlockId (uint64_t segmentNum)
	Set the FinalBlockId.

Data &	clearFinalBlockId ()
	Clear the FinalBlockId.

Signature fields
SignatureType	signatureType () const
	Get the signature type.

Data &	setSignatureType (SignatureType type)
	Set the signature type.

const Name *	keyLocator () const
	Get the KeyLocator.

bool	hasKeyLocator () const
	Check if KeyLocator is set.

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

Data &	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.

bool	hasSignature () const
	Check if a signature is set.

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< Data >	fromWire (const uint8_t *buf, size_t len)
	Decode a Data packet from TLV wire format.

Detailed Description

NDN Data packet.

A Data packet contains the content returned by a producer in response to an Interest. Only the Name field is required; Content and FreshnessPeriod are optional.

// Create and configure a Data packet
ndn::Data data;
data.setName("/sensor/temperature");
data.setContent("25.5 C");
data.setFreshnessPeriod(10000);  // Valid for 10 seconds
 
// Encode
uint8_t buf[256];
size_t len = 0;
if (data.encode(buf, sizeof(buf), len) == ndn::Error::Success) {
    // Send buf over the network
}
 
// Decode
auto result = ndn::Data::fromWire(buf, len);
if (result.ok()) {
    printf("Content: %.*s\n",
           (int)result.value.contentSize(),
           result.value.content());
}

Definition at line 49 of file data.hpp.

Constructor & Destructor Documentation

◆ Data() [1/2]

ndn::Data::Data ( )

default

Default constructor.

Creates an empty Data packet. Name is empty, Content is empty, and FreshnessPeriod is unset.

◆ Data() [2/2]

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

explicit

Create a Data packet with a specified Name.

Parameters

name	The Data name

Definition at line 10 of file data.cpp.

Member Function Documentation

◆ clearFinalBlockId()

Data & ndn::Data::clearFinalBlockId ( )

Clear the FinalBlockId.

Returns: Reference to this Data

Definition at line 49 of file data.cpp.

◆ clearKeyLocator()

Data & ndn::Data::clearKeyLocator ( )

Clear the KeyLocator.

Returns: Reference to this Data

Definition at line 70 of file data.cpp.

◆ content()

const uint8_t * ndn::Data::content ( ) const

inline

Get a pointer to the content data.

Returns: Pointer to the content buffer

Definition at line 135 of file data.hpp.

Referenced by ndn::Certificate::fromData(), and ndn::Link::fromData().

◆ contentSize()

size_t ndn::Data::contentSize ( ) const

inline

Get the content size.

Returns: Content size in bytes

Definition at line 141 of file data.hpp.

Referenced by ndn::Certificate::fromData(), and ndn::Link::fromData().

◆ contentType()

ContentType ndn::Data::contentType ( ) const

inline

Get the content type.

Returns: Content type

Definition at line 177 of file data.hpp.

Referenced by ndn::Certificate::fromData(), and ndn::Link::fromData().

◆ encode()

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

Encode the Data packet 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 317 of file data.cpp.

References ndn::TlvEncoder::current(), ndn::tlv::Data, ndn::PACKET_MAX_SIZE, ndn::TlvEncoder::position(), ndn::TlvEncoder::remaining(), ndn::TlvEncoder::setPosition(), ndn::tlv::SignatureValue, ndn::TlvEncoder::size(), ndn::varNumberSize(), ndn::TlvEncoder::writeBytes(), ndn::TlvEncoder::writeLength(), ndn::TlvEncoder::writeTlv(), and ndn::TlvEncoder::writeType().

◆ finalBlockId()

std::optional< uint64_t > ndn::Data::finalBlockId ( ) const

inline

Get the FinalBlockId.

FinalBlockId indicates the last segment number in segmented transfer. The segment number is typically used as the last component of the Name.

Returns: FinalBlockId value if set, nullopt if unset

Definition at line 227 of file data.hpp.

◆ freshnessPeriod()

std::optional< uint32_t > ndn::Data::freshnessPeriod ( ) const

inline

Get the FreshnessPeriod.

FreshnessPeriod indicates the freshness duration of the Data (milliseconds). Within this period, cached responses from the Content Store are possible.

Returns: FreshnessPeriod (milliseconds) if set, nullopt if unset

Definition at line 205 of file data.hpp.

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

◆ fromWire()

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

static

Decode a Data packet from TLV wire format.

Parameters

buf	Input buffer
len	Buffer length

Returns: Data and Error::Success on success, Error::InvalidPacket if TLV Type is not 0x06, Error::InvalidPacket if Name is missing

Definition at line 362 of file data.cpp.

References ndn::tlv::Content, ndn::tlv::ContentType, ndn::TlvDecoder::current(), ndn::tlv::Data, ndn::DATA_MAX_CONTENT_SIZE, ndn::tlv::FinalBlockId, ndn::tlv::FreshnessPeriod, ndn::Name::fromWire(), ndn::tlv::KeyLocator, ndn::tlv::MetaInfo, ndn::tlv::Name, ndn::TlvDecoder::position(), ndn::TlvDecoder::readBytes(), ndn::TlvDecoder::readNonNegativeInteger(), ndn::TlvDecoder::readTlvHeader(), ndn::TlvDecoder::remaining(), ndn::TlvDecoder::setPosition(), ndn::SIGNATURE_MAX_SIZE, ndn::tlv::SignatureInfo, ndn::tlv::SignatureType, ndn::tlv::SignatureValue, and ndn::TlvDecoder::skip().

Referenced by ndn::Certificate::fromWire().

◆ hasContent()

bool ndn::Data::hasContent ( ) const

inline

Check if content is set.

Returns: true if content is present

Definition at line 147 of file data.hpp.

Referenced by ndn::Certificate::fromData(), and ndn::Link::fromData().

◆ hasFinalBlockId()

bool ndn::Data::hasFinalBlockId ( ) const

inline

Check if FinalBlockId is set.

Returns: true if FinalBlockId is present

Definition at line 233 of file data.hpp.

◆ hasKeyLocator()

bool ndn::Data::hasKeyLocator ( ) const

inline

Check if KeyLocator is set.

Returns: true if KeyLocator is present

Definition at line 283 of file data.hpp.

◆ hasSignature()

bool ndn::Data::hasSignature ( ) const

inline

Check if a signature is set.

Returns: true if a signature is present

Definition at line 314 of file data.hpp.

Referenced by ndn::Certificate::fromData().

◆ isLink()

bool ndn::Data::isLink ( ) const

inline

Check if this is a Link Object.

Returns: true if ContentType::Link

Definition at line 190 of file data.hpp.

◆ keyLocator()

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

inline

Get the KeyLocator.

Returns the reference information (Name) of the key used for signing. Required for RSA/ECDSA/Ed25519 signatures, prohibited for DigestSha256.

Returns: KeyLocator Name if set, nullptr if unset

Definition at line 277 of file data.hpp.

◆ name() [1/2]

Name & ndn::Data::name ( )

inline

Get the Name (reference)

Returns: Reference to the Name

Definition at line 110 of file data.hpp.

◆ name() [2/2]

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

inline

Get the Name (const reference)

Returns: Const reference to the Name

Definition at line 104 of file data.hpp.

Referenced by ndn::Certificate::fromData(), ndn::Link::fromData(), ndn::ContentStore::insert(), ndn::Forwarder::putData(), setKeyLocator(), and setName().

◆ setContent() [1/2]

Error ndn::Data::setContent	(	const uint8_t *	data,
		size_t	size
	)

Set binary data as content.

Parameters

data	Pointer to the content data
size	Data size (bytes)

Returns: Error::Success on success, Error::BufferTooSmall if size exceeds DATA_MAX_CONTENT_SIZE

Definition at line 26 of file data.cpp.

References ndn::DATA_MAX_CONTENT_SIZE.

Referenced by setContent(), ndn::Certificate::toData(), and ndn::Link::toData().

◆ setContent() [2/2]

Error ndn::Data::setContent ( std::string_view str )

Set a string as content.

Parameters

str	Content string

Returns: Error::Success on success, Error::BufferTooSmall if size exceeds DATA_MAX_CONTENT_SIZE

Definition at line 35 of file data.cpp.

References setContent().

◆ setContentType()

Data & ndn::Data::setContentType ( ContentType type )

Set the content type.

Parameters

type	Content type

Returns: Reference to this Data

Definition at line 54 of file data.cpp.

Referenced by ndn::Certificate::toData(), and ndn::Link::toData().

◆ setFinalBlockId()

Data & ndn::Data::setFinalBlockId ( uint64_t segmentNum )

Set the FinalBlockId.

Sets the last segment number in segmented transfer.

Parameters

segmentNum Last segment number

Returns: Reference to this Data

Definition at line 44 of file data.cpp.

◆ setFreshnessPeriod()

Data & ndn::Data::setFreshnessPeriod ( uint32_t periodMs )

Set the FreshnessPeriod.

Parameters

periodMs Freshness period (milliseconds)

Returns: Reference to this Data

Definition at line 39 of file data.cpp.

Referenced by ndn::Certificate::toData().

◆ setKeyLocator()

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

Set the KeyLocator.

Parameters

name	Name identifying the key

Returns: Reference to this Data

Definition at line 64 of file data.cpp.

References name().

◆ setName() [1/2]

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

Set the Name (supports method chaining)

Parameters

name	Name to set

Returns: Reference to this Data

Definition at line 12 of file data.cpp.

References name().

Referenced by ndn::Certificate::toData(), and ndn::Link::toData().

◆ setName() [2/2]

Error ndn::Data::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 17 of file data.cpp.

References ndn::Name::fromUri().

◆ setSignatureType()

Data & ndn::Data::setSignatureType ( SignatureType type )

Set the signature type.

Parameters

type	Signature type

Returns: Reference to this Data

Definition at line 59 of file data.cpp.

Referenced by ndn::Certificate::toData().

◆ signatureType()

SignatureType ndn::Data::signatureType ( ) const

inline

Get the signature type.

Returns: Signature type

Definition at line 260 of file data.hpp.

Referenced by ndn::Certificate::fromData().

◆ signatureValue()

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

inline

Get a pointer to the signature value.

Returns: Pointer to the signature value buffer

Definition at line 302 of file data.hpp.

Referenced by ndn::Certificate::fromData().

◆ signatureValueSize()

size_t ndn::Data::signatureValueSize ( ) const

inline

Get the size of the signature value.

Returns: Size of the signature value in bytes

Definition at line 308 of file data.hpp.

Referenced by ndn::Certificate::fromData().

◆ signWithDigestSha256()

Error ndn::Data::signWithDigestSha256 ( )

Sign with DigestSha256.

Computes a SHA-256 digest from Name, MetaInfo, Content, and SignatureInfo, and stores it in SignatureValue. signatureType is set to DigestSha256.

Returns: Error::Success on success

Definition at line 169 of file data.cpp.

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

◆ signWithEcdsa()

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

Sign with ECDSA P-256.

Computes an ECDSA signature using the specified private key and stores it in SignatureValue. signatureType is set to SignatureSha256WithEcdsa. It is recommended to set the KeyLocator beforehand.

Parameters

privKey Private key (32 bytes)

Returns: Error::Success on success

Definition at line 272 of file data.cpp.

References ndn::PACKET_MAX_SIZE.

◆ signWithHmac()

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

Sign with HMAC-SHA256.

Computes HMAC-SHA256 using the specified key and stores it in SignatureValue. signatureType is set to SignatureHmacWithSha256.

Parameters

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

Returns: Error::Success on success

Definition at line 190 of file data.cpp.

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

◆ verifyDigestSha256()

bool ndn::Data::verifyDigestSha256 ( ) const

Verify a DigestSha256 signature.

Returns: true if the signature is valid

Definition at line 215 of file data.cpp.

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

◆ verifyEcdsa()

bool ndn::Data::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 293 of file data.cpp.

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

◆ verifyHmac()

bool ndn::Data::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 242 of file data.cpp.

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

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

include/ndn/data.hpp
src/data.cpp

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ Data() [1/2]

◆ Data() [2/2]

Member Function Documentation

◆ clearFinalBlockId()

◆ clearKeyLocator()

◆ content()

◆ contentSize()

◆ contentType()

◆ encode()

◆ finalBlockId()

◆ freshnessPeriod()

◆ fromWire()

◆ hasContent()

◆ hasFinalBlockId()

◆ hasKeyLocator()

◆ hasSignature()

◆ isLink()

◆ keyLocator()

◆ name() [1/2]

◆ name() [2/2]

◆ setContent() [1/2]

◆ setContent() [2/2]

◆ setContentType()

◆ setFinalBlockId()

◆ setFreshnessPeriod()

◆ setKeyLocator()

◆ setName() [1/2]

◆ setName() [2/2]

◆ setSignatureType()

◆ signatureType()

◆ signatureValue()

◆ signatureValueSize()

◆ signWithDigestSha256()

◆ signWithEcdsa()

◆ signWithHmac()

◆ verifyDigestSha256()

◆ verifyEcdsa()

◆ verifyHmac()