Class: Packet

Constructor

new Packet(dataopt)

Parameters:

Name Type Attributes Description

data

Object

Packet data, options object, or existing packet

Properties

Name	Type	Attributes	Description
`buffer`	Buffer	<optional>	Raw packet buffer for parsing existing packets
`iface`	Object	<optional>	Network interface configuration

Source: packet.js, line 33

Examples

// Create an ICMP echo request packet
const packet = new Packet({ iface: 'eth0' })
  .Ethernet({ dst: 'ff:ff:ff:ff:ff:ff', src: '00:11:22:33:44:55' })
  .IPv4({ src: '192.168.1.1', dst: '8.8.8.8', timeToLive: 64 })
  .ICMP({ type: 8, code: 0, id: 12345, sequence: 1 });

// Parse existing packet
const packet = new Packet({ buffer: rawBuffer });
console.log(packet.layers.IPv4.src);

Extends

LayersList

Members

buffer

Raw buffer containing the complete packet data Automatically builds packet if layers were added

Source: packet.js, line 297

Methods

ARP(data) → {Packet}

Adds ARP layer to the packet stack

Parameters:

Name Type Description

data

Object

The layer data

Properties

Name	Type	Description
`hardwareType`	number	Hardware type (HTYPE)
`protocolType`	number	Protocol type (PTYPE)
`hardwareLength`	number	Hardware address length (HLEN)
`protocolLength`	number	Protocol length (PLEN)
`opcode`	'who-has' \| 'is-at'	Operation: 1 (request) for `who-has`, 2 (reply) for `is-at`.
`hardwareSrc`	string	Sender hardware address (SHA)
`protocolSrc`	string	Sender protocol address (SPA)
`hardwareDst`	string	Target hardware address (THA)
`protocolDst`	string	Target protocol address (TPA)

Returns:

the packet instance

Type:: Packet

DHCP(data) → {Packet}

Adds DHCP layer to the packet stack

Parameters:

Name Type Description

data

Object

The layer data

Properties

Name	Type	Description
`opCode`	number	BootP opcode.
`hardwareType`	number	Hardware type (1 = Ethernet).
`hardwareAddressLength`	number	Hardware address length (6 = MAC).
`hops`	number	Hop count.
`transactionId`	number	DHCP transaction ID.
`clientIpAddress`	string	Client IPv4 address (string form).
`yourIpAddress`	string	Your IPv4 address (string form).
`serverIpAddress`	number	Server IPv4 address as raw uint32.
`gatewayIpAddress`	string	Gateway IPv4 address (string form).
`clientHardwareAddress`	string	Client hardware address (MAC, first 6 bytes of 16).
`serverName`	string	BootP server name (C-string).
`bootFilename`	string	BootP boot file name (C-string).
`magicNumber`	number	DHCP magic number (0x63825363).

Returns:

the packet instance

Type:: Packet

DNS(data) → {Packet}

Adds DNS layer to the packet stack

Parameters:

Name Type Description

data

Object

The layer data

Properties

Name	Type	Description
`id`	number	Transaction identifier.
`qr`	number	Query/response flag (0 = query, 1 = response).
`opcode`	number	4-bit query opcode.
`aa`	number	Authoritative answer flag.
`tc`	number	Truncation flag.
`rd`	number	Recursion desired flag.
`ra`	number	Recursion available flag.
`rcode`	number	4-bit response code.
`qdCount`	number	Number of questions.
`anCount`	number	Number of answers.
`nsCount`	number	Number of authority records.
`arCount`	number	Number of additional records.

Returns:

the packet instance

Type:: Packet

Ethernet(data) → {Packet}

Adds Ethernet layer to the packet stack

Parameters:

Name Type Description

data

Object

The layer data

Properties

Name	Type	Description
`src`	string	Source MAC address.
`dst`	string	Destination MAC address.
`type`	number	Protocol type.

Returns:

the packet instance

Type:: Packet

GRE(data) → {Packet}

Adds GRE layer to the packet stack

Parameters:

Name Type Description

data

Object

The layer data

Properties

Name	Type	Description
`version`	number	Version number, must be 0 for standard GRE.
`protocol`	number	EtherType of the encapsulated protocol.
`checksumFlag`	number	Indicates that the checksum field is present.
`keyFlag`	number	Indicates that the key field is present.
`sequenceFlag`	number	Indicates that the sequence number field is present.

Returns:

the packet instance

Type:: Packet

ICMP(data) → {Packet}

Adds ICMP layer to the packet stack

Parameters:

Name Type Description

data

Object

The layer data

Properties

Name	Type	Description
`type`	number	ICMP message type (see ICMPTypes)
`code`	number	ICMP message code
`checksum`	number	ICMP checksum
`typeName`	string	Human-readable name of the ICMP message type
`isEchoRequest`	boolean	True for type=8 (EchoRequest).
`isEchoReply`	boolean	True for type=0 (EchoReply).
`isDestinationUnreachable`	boolean	True for type=3.
`isTimeExceeded`	boolean	True for type=11.
`isParameterProblem`	boolean	True for type=12.
`isTimestampRequest`	boolean	True for type=13.
`isTimestampReply`	boolean	True for type=14.

Returns:

the packet instance

Type:: Packet

ICMPv6(data) → {Packet}

Adds ICMPv6 layer to the packet stack

Parameters:

Name Type Description

data

Object

The layer data

Properties

Name	Type	Description
`type`	number	ICMPv6 message type (see ICMPv6Types).
`code`	number	ICMPv6 message code.
`checksum`	number	ICMPv6 checksum.

Returns:

the packet instance

Type:: Packet

IPv4(data) → {Packet}

Adds IPv4 layer to the packet stack

Parameters:

Name Type Description

data

Object

The layer data

Properties

Name	Type	Description
`headerLength`	number	IP header length, has the value of 5 for IPv4.
`version`	number	IP version number, has the value of 4 for IPv4.
`typeOfService`	number	Type of service / DSCP.
`totalLength`	number	Entire packet (fragment) size, including header and data, in bytes.
`id`	number	Identification field used for fragmentation.
`fragmentOffsetRaw`	number	Fragment offset field (raw, includes flags) @LE.
`timeToLive`	number	Hop count.
`protocol`	number	Encapsulated protocol number (one of IPProtocolTypes).
`checksum`	number	Header checksum.
`src`	string	IPv4 address of the sender.
`dst`	string	IPv4 address of the receiver.

Returns:

the packet instance

Type:: Packet

IPv6(data) → {Packet}

Adds IPv6 layer to the packet stack

Parameters:

Name Type Description

data

Object

The layer data

Properties

Name	Type	Description
`version`	number	IP version, has the value of 6 for IPv6.
`trafficClass`	number	Traffic class (DSCP + ECN), 8 bits.
`flowLabel`	number	Flow label, 20 bits.
`payloadLength`	number	Length of payload following the header in bytes.
`nextHeader`	number	Next header type. Must be one of ::IPProtocolTypes.
`hopLimit`	number	Hop limit, decremented by each forwarder.
`src`	string	IPv6 source address in human-readable form.
`dst`	string	IPv6 destination address in human-readable form.

Returns:

the packet instance

Type:: Packet

NTP(data) → {Packet}

Adds NTP layer to the packet stack

Parameters:

Name Type Description

data

Object

The layer data

Properties

Name	Type	Description
`li`	number	Leap indicator (0..3).
`vn`	number	Version number (typically 3 or 4).
`mode`	number	Mode (1=symmetric active, 3=client, 4=server, 5=broadcast).
`stratum`	number	Stratum level (0=unspecified, 1=primary, 2-15=secondary).
`poll`	number	Poll interval as signed log2 seconds.
`precision`	number	Precision as signed log2 seconds.
`rootDelay`	number	32-bit fixed-point root delay.
`rootDispersion`	number	32-bit fixed-point root dispersion.
`referenceId`	number	Reference identifier (4 bytes; IPv4 or 4-char ASCII).
`referenceTimestamp`	Date \| null	Time at which the local clock was last set.
`originTimestamp`	Date \| null	Time at the client when the request was sent.
`receiveTimestamp`	Date \| null	Time at the server when the request was received.
`transmitTimestamp`	Date \| null	Time at the server when the response was sent.

Returns:

the packet instance

Type:: Packet

Payload(data) → {Packet}

Adds Payload layer to the packet stack

Parameters:

Name	Type	Description
`data`	Object	The layer data

Returns:

the packet instance

Type:: Packet

TCP(data) → {Packet}

Adds TCP layer to the packet stack

Parameters:

Name Type Description

data

Object

The layer data

Properties

Name	Type	Description
`src`	number	Source TCP port.
`dst`	number	Destination TCP port.
`seq`	number	Sequence number.
`ack`	number	Acknowledgment number.
`windowSize`	number	Receive window size.
`checksum`	number	Header + data checksum.
`urgentPointer`	number	Urgent data byte offset (when URG is set).
`flags`	TCPFlags	TCP flags.

Returns:

the packet instance

Type:: Packet

UDP(data) → {Packet}

Adds UDP layer to the packet stack

Parameters:

Name Type Description

data

Object

The layer data

Properties

Name	Type	Description
`src`	number	Source UDP port.
`dst`	number	Destination UDP port.
`totalLength`	number	Length in bytes of the UDP datagram (header + data).
`checksum`	number	16-bit checksum field for error-checking.

Returns:

the packet instance

Type:: Packet

Vlan(data) → {Packet}

Adds Vlan layer to the packet stack

Parameters:

Name Type Description

data

Object

The layer data

Properties

Name	Type	Description
`vid`	number	12-bit VLAN identifier (0..4095).
`dei`	number	Drop Eligible Indicator (0 or 1).
`pcp`	number	Priority Code Point (0..7).
`etherType`	number	EtherType of the encapsulated payload.

Returns:

the packet instance

Type:: Packet

clone() → {Packet}

Creates a deep clone of the packet Preserves all layers, timestamps, and interface settings

Source: packet.js, line 310

Returns:

New packet instance identical to this one

Type:: Packet

equals(pkt) → {boolean}

Compares this packet with another packet for equality

Parameters:

Name	Type	Description
`pkt`	Packet	The packet to compare with

Source: packet.js, line 100

Returns:

True if packets are identical (same interface, timestamp, and buffer content)

Type:: boolean

Example

const packet1 = new Packet({ buffer: data });
const packet2 = new Packet({ buffer: data });
if (packet1.equals(packet2)) {
  console.log('Packets are identical');
}

toObject() → {Object|Object|Object}

Converts the packet to a plain JavaScript object

Source: packet.js, line 266

Returns:

Plain object representation
Type:
Object
returns.iface - Interface configuration
Type:
Object
returns.layers - Layer objects with their fields
Type:
Object

Example

const obj = packet.toObject();
console.log(obj.layers.IPv4.src);