packet

Documentation

Index

• Constants
• func GenICMP(srcIP, dstIP IP, ipid uint16, icmpType, icmpCode uint8, payload []byte) []byte
• func Hexdump(b []byte) string
• type IP
  • func NewIP(b net.IP) IP
  • func (ip IP) String() string
• type IPProto
  • func (p IPProto) String() string
• type QDecode
  • func (q *QDecode) Decode(b []byte)
  • func (q *QDecode) EchoRespond() []byte
  • func (q *QDecode) IsEchoRequest() bool
  • func (q *QDecode) IsEchoResponse() bool
  • func (q *QDecode) IsError() bool
  • func (q *QDecode) IsTCPSyn() bool
  • func (q *QDecode) String() string
  • func (q *QDecode) Sub(begin, n int) []byte
  • func (q *QDecode) Trim() []byte

Constants

const (
	ICMPEchoReply    = 0x00
	ICMPEchoRequest  = 0x08
	ICMPUnreachable  = 0x03
	ICMPTimeExceeded = 0x0b
)

ICMP types.

const (
	TCPSyn    = 0x02
	TCPAck    = 0x10
	TCPSynAck = TCPSyn | TCPAck
)

Functions

func GenICMP

func GenICMP(srcIP, dstIP IP, ipid uint16, icmpType, icmpCode uint8, payload []byte) []byte

GenICMP returns the bytes of an ICMP packet. If payload is too short or too long, it returns nil.

func Hexdump

func Hexdump(b []byte) string

Types

type IP

type IP uint32

IP is an IPv4 address.

func NewIP

func NewIP(b net.IP) IP

NewIP converts a standard library IP address into an IP. It panics if b is not an IPv4 address.

func (IP) String

func (ip IP) String() string

type IPProto

type IPProto int

const (
	Junk IPProto = iota
	Fragment
	ICMP
	UDP
	TCP
)

func (IPProto) String

func (p IPProto) String() string

type QDecode

type QDecode struct {
	IPProto  IPProto // IP subprotocol (UDP, TCP, etc)
	SrcIP    IP      // IP source address
	DstIP    IP      // IP destination address
	SrcPort  uint16  // TCP/UDP source port
	DstPort  uint16  // TCP/UDP destination port
	TCPFlags uint8   // TCP flags (SYN, ACK, etc)
	// contains filtered or unexported fields
}

func (*QDecode) Decode

func (q *QDecode) Decode(b []byte)

An extremely simple packet decoder for basic IPv4 packet types. It extracts only the subprotocol id, IP addresses, and (if any) ports, and shouldn't need any memory allocation.

func (*QDecode) EchoRespond

func (q *QDecode) EchoRespond() []byte

EchoResponse returns an IPv4 ICMP echo reply to the request in q.

func (*QDecode) IsEchoRequest

func (q *QDecode) IsEchoRequest() bool

IsEchoRequest reports whether q is an IPv4 ICMP Echo Request.

func (*QDecode) IsEchoResponse

func (q *QDecode) IsEchoResponse() bool

IsEchoRequest reports whether q is an IPv4 ICMP Echo Response.

func (*QDecode) IsError

func (q *QDecode) IsError() bool

IsError reports whether q is an IPv4 ICMP "Error" packet.

func (*QDecode) IsTCPSyn

func (q *QDecode) IsTCPSyn() bool

IsTCPSyn reports whether q is a TCP SYN packet (i.e. the first packet in a new connection).

func (*QDecode) String

func (q *QDecode) String() string

func (*QDecode) Sub

func (q *QDecode) Sub(begin, n int) []byte

Returns a subset of the IP subprotocol section.

func (*QDecode) Trim

func (q *QDecode) Trim() []byte

Trim trims the buffer to its IPv4 length. Sometimes packets arrive from an interface with extra bytes on the end. This removes them.