common

Documentation

Overview

Package common contains common functionality for both TCP and UDP traceroute implementations

Index

• Variables
• func LocalAddrForHost(destIP net.IP, destPort uint16) (*net.UDPAddr, net.Conn, error)
• type CanceledError
  • func (c CanceledError) Error() string
• type Hop
• type MatcherFunc
• type MismatchError
  • func (m MismatchError) Error() string
• type ProbeResponse
  • func TracerouteParallel(ctx context.Context, t TracerouteDriver, p TracerouteParallelParams) ([]*ProbeResponse, error)
• type Results
• type TracerouteDriver
• type TracerouteParallelParams

Variables

var ErrReceiveProbeNoPkt = errors.New("ReceiveProbe() doesn't have new packets")

ErrReceiveProbeNoPkt is returned when ReceiveProbe() didn't find anything new. This is normal if the RTT is long

Functions

func LocalAddrForHost

func LocalAddrForHost(destIP net.IP, destPort uint16) (*net.UDPAddr, net.Conn, error)

LocalAddrForHost takes in a destionation IP and port and returns the local address that should be used to connect to the destination. The returned connection should be closed by the caller when the the local UDP port is no longer needed

Types

type CanceledError

type CanceledError string

CanceledError is sent when a listener is canceled

func (CanceledError) Error

func (c CanceledError) Error() string

Error implements the error interface for CanceledError

type Hop

type Hop struct {
	IP       net.IP
	Port     uint16
	ICMPType uint8
	ICMPCode uint8
	RTT      time.Duration
	IsDest   bool
}

Hop encapsulates information about a single hop in a traceroute

type MatcherFunc

type MatcherFunc func(*ipv4.Header, []byte, net.IP, uint16, net.IP, uint16, uint32) (net.IP, error)

MatcherFunc defines functions for matching a packet from the wire to a traceroute based on the source/destination addresses and an identifier

type MismatchError

type MismatchError string

MismatchError is an error type that indicates a MatcherFunc failed due to one or more fields from the packet not matching the expected information

func (MismatchError) Error

func (m MismatchError) Error() string

Error implements the error interface for MismatchError

type ProbeResponse

type ProbeResponse struct {
	// TTL is the Time To Live of the probe that was originally sent
	TTL uint8
	// IP is the IP address of the responding host
	IP netip.Addr
	// RTT is the round-trip time of the probe
	RTT time.Duration
	// IsDest is true if the responding host is the destination
	IsDest bool
}

ProbeResponse is the response of a single probe in a traceroute

func TracerouteParallel

func TracerouteParallel(ctx context.Context, t TracerouteDriver, p TracerouteParallelParams) ([]*ProbeResponse, error)

TracerouteParallel runs a traceroute in parallel

type Results

type Results struct {
	Source     net.IP
	SourcePort uint16
	Target     net.IP
	DstPort    uint16
	Hops       []*Hop
}

Results encapsulates a response from the traceroute

type TracerouteDriver

type TracerouteDriver interface {
	// SendProbe sends a traceroute packet with a specific TTL
	SendProbe(ttl uint8) error
	// ReceiveProbe polls to get a traceroute response with a timeout
	ReceiveProbe(timeout time.Duration) (*ProbeResponse, error)
}

TracerouteDriver is an implementation of traceroute send+receive of packets

type TracerouteParallelParams

type TracerouteParallelParams struct {
	// MinTTL is the TTL to start the traceroute at
	MinTTL uint8
	// MaxTTL is the TTL to end the traceroute at
	MaxTTL uint8
	// TracerouteTimeout is the maximum time to wait for a response
	TracerouteTimeout time.Duration
	// PollFrequency is how often to poll for a response
	PollFrequency time.Duration
	// SendDelay is the delay between sending probes (typically small)
	SendDelay time.Duration
}

TracerouteParallelParams are the parameters for TracerouteParallel