header

import "github.com/TheManticoreProject/Manticore/network/llmnr/message/header"

Index

Constants
type Flags
type Header

Constants

Size of LLMNR message header in bytes

const HeaderSize = 12

type Flags

type Flags uint16

LLMNR Header Flags

const (
    FlagQR Flags = 1 << 15 // Query/Response flag
    FlagOP Flags = 1 << 14 // Operation code
    FlagC  Flags = 1 << 13 // Conflict flag
    FlagTC Flags = 1 << 12 // Truncation flag
    FlagT  Flags = 1 << 11 // Tentative flag
)

func (Flags) IsConflict

func (f Flags) IsConflict() bool

IsConflict returns true if the conflict flag is set.

func (Flags) IsQuery

func (f Flags) IsQuery() bool

IsQuery returns true if the flags are set for a query.

func (Flags) IsResponse

func (f Flags) IsResponse() bool

IsResponse returns true if the flags are set for a response.

func (Flags) IsTentative

func (f Flags) IsTentative() bool

IsTentative returns true if the tentative flag is set.

func (Flags) IsTruncation

func (f Flags) IsTruncation() bool

IsTruncation returns true if the truncation flag is set.

func (*Flags) Marshal

func (f *Flags) Marshal() ([]byte, error)

Marshal encodes the Flags into a 2-byte big-endian representation.

func (Flags) String

func (f Flags) String() string

String returns a string representation of the flags.

The QR label is emitted only when the QR bit is set (response), matching the convention used in DNS trace output. Query messages (QR=0) produce no QR label. OPCODE is a separate 4-bit field and is not derived from the QR bit.

func (*Flags) Unmarshal

func (f *Flags) Unmarshal(data []byte) (int, error)

Unmarshal decodes a 2-byte big-endian representation into the Flags receiver. It returns an error if the input slice is not exactly 2 bytes.

Header represents the LLMNR message header.

The header contains essential information about the LLMNR message, including the message ID, flags, and counts of various sections such as questions, answers, authority records, and additional records.

Fields:

Identifier: A 16-bit identifier assigned by the program that generates any kind of query. This identifier is copied to the corresponding reply and can be used by the requester to match up replies to outstanding queries.
Flags: A 16-bit field containing various flags that control the message flow and interpretation. These flags include the Query/Response flag (QR), Operation code (OP), Conflict flag (C), Truncation flag (TC), and Tentative flag (T).
QDCount: An unsigned 16-bit integer specifying the number of entries in the question section of the message.
ANCount: An unsigned 16-bit integer specifying the number of resource records in the answer section of the message.
NSCount: An unsigned 16-bit integer specifying the number of name server resource records in the authority records section of the message.
ARCount: An unsigned 16-bit integer specifying the number of resource records in the additional records section of the message.

Usage example:

header := Header{
    Identifier: 12345,
    Flags:   FlagQR,
    QDCount: 1,
    ANCount: 0,
    NSCount: 0,
    ARCount: 0,
}

type Header struct {
    Identifier uint16 `json:"identifier"`
    Flags      Flags  `json:"flags"`
    QDCount    uint16 `json:"qd_count"` // Question count
    ANCount    uint16 `json:"an_count"` // Answer count
    NSCount    uint16 `json:"ns_count"` // Authority count
    ARCount    uint16 `json:"ar_count"` // Additional count
}

func (h *Header) Describe(indent int)

Describe prints a detailed description of the Header struct. Parameters: - indent: An integer value specifying the indentation level for the output.

func (h *Header) Marshal() ([]byte, error)

Marshal encodes the Header into a 12-byte big-endian representation.

func (h *Header) Unmarshal(data []byte) (int, error)

Unmarshal decodes a 12-byte big-endian representation into the Header receiver. It returns an error if the input slice is not exactly 12 bytes.