packet

Documentation

Index

• func Assemble(p ParsedPacket, max int) ([]byte, error)
• func EncodeName(n Namelabel) (payload []byte)
• func ParseSoaTtl(buf []byte) uint32
• type EdnsAttribute
• type EdnsRecord
• type Namelabel
  • func NewNamelabel(name []string) Namelabel
  • func NewNamelabelString(str string) Namelabel
  • func ParseName(buf []byte) (Namelabel, error)
  • func (l Namelabel) IsChildOf(parent Namelabel) bool
  • func (l Namelabel) Len() int
  • func (l Namelabel) PoppedLabel(n int) Namelabel
  • func (l Namelabel) String() string
  • func (l Namelabel) ToLower() Namelabel
• type ParsedPacket
  • func Parse(buf []byte) (p *ParsedPacket, perr error)
• type ParsedPacketHeader
• type QuestionFormat
• type ResourceRecordFormat

Functions

func Assemble

func Assemble(p ParsedPacket, max int) ([]byte, error)

Assemble returns a possibly truncated payload for a ParsedPacket. Setting max to a negative value disables truncation.

func EncodeName

func EncodeName(n Namelabel) (payload []byte)

EncodeName encodes a namelabel into the DNS on-wire format: <strlen1><rawstr1><strlen2><rawstr2>

func ParseSoaTtl

func ParseSoaTtl(buf []byte) uint32

Types

type EdnsAttribute

type EdnsAttribute struct {
	Code uint16
	Data []byte
}

type EdnsRecord

type EdnsRecord struct {
	// Whether or not EDNS data is present.
	Present bool
	Version uint8

	UdpPayloadSize uint16
	FlagDnssecOk   bool
	Attributes     []EdnsAttribute
	// contains filtered or unexported fields
}

type Namelabel

type Namelabel struct {
	// contains filtered or unexported fields
}

String array typed to describe DNS labels

func NewNamelabel

func NewNamelabel(name []string) Namelabel

func NewNamelabelString

func NewNamelabelString(str string) Namelabel

NewNamelabelString returns a new absolute namelabel from given string.

func ParseName

func ParseName(buf []byte) (Namelabel, error)

func (Namelabel) IsChildOf

func (l Namelabel) IsChildOf(parent Namelabel) bool

Returns true if given namelabel is a child of *parent

func (Namelabel) Len

func (l Namelabel) Len() int

Returs the number of labels in the list (1 == .)

func (Namelabel) PoppedLabel

func (l Namelabel) PoppedLabel(n int) Namelabel

Pops a label from the label list, walking the hierarchy

func (Namelabel) String

func (l Namelabel) String() string

func (Namelabel) ToLower

func (l Namelabel) ToLower() Namelabel

ToLower returns a lowercased version of the namelabel.

type ParsedPacket

type ParsedPacket struct {
	Header      ParsedPacketHeader
	Questions   []QuestionFormat
	Answers     []ResourceRecordFormat
	Nameservers []ResourceRecordFormat
	Additionals []ResourceRecordFormat
	Edns        EdnsRecord
}

A fully parsed DNS packet

func Parse

func Parse(buf []byte) (p *ParsedPacket, perr error)

type ParsedPacketHeader

type ParsedPacketHeader struct {
	Id              uint16 // Id of this query
	Response        bool   // `true' if this is a response (qr)
	Opcode          uint8  // The RFC1035 opcode of this query (usually OP_QUERY)
	Authoritative   bool   // `true' if we have authorative data in the reply
	Truncated       bool   // `true' if the query was truncated and might be re-done using TCP or EDNS
	RecDesired      bool   // `true' if the client asked us to resolve recursively
	RecAvailable    bool   // indicates if the host generating this reply is willing to do recursive queries
	ResponseCode    uint16 // RFC1035 or EDNS response code, such as NXDOMAIN
	QuestionCount   uint16 // Number of questions in this packet
	AnswerCount     uint16 // Number of items in the answer section
	NameserverCount uint16 // Number of items in the NS section
	AdditionalCount uint16 // Number of items in the additional section
}

The parsed representation of a DNS header

type QuestionFormat

type QuestionFormat struct {
	Name  Namelabel
	Type  uint16
	Class uint16
}

Question section of the DNS packet

type ResourceRecordFormat

type ResourceRecordFormat struct {
	Name  Namelabel
	Type  uint16
	Class uint16
	Ttl   uint32
	Data  []byte // note: this is RAW data!
}

RR section of a DNS packet