snowflake_proxy

Documentation

Overview

Package snowflake_proxy provides functionality for creating, starting, and stopping a snowflake proxy.

To run a proxy, you must first create a proxy configuration. Unconfigured fields will be set to the defined defaults.

proxy := snowflake_proxy.SnowflakeProxy{
	BrokerURL: "https://snowflake-broker.example.com",
	STUNURL: "stun:stun.l.google.com:19302",
	// ...
}

You may then start and stop the proxy. Stopping the proxy will close existing connections and the proxy will not poll for more clients.

go func() {
	err := proxy.Start()
	// handle error
}

// ...

proxy.Stop()

Index

• Constants
• func NewProxyEventLogger(logPeriod time.Duration, output io.Writer) event.SnowflakeEventReceiver
• type SignalingServer
  • func (s *SignalingServer) Post(path string, payload io.Reader) ([]byte, error)
• type SnowflakeProxy
  • func (sf *SnowflakeProxy) Start() error
  • func (sf *SnowflakeProxy) Stop()

Constants

const (
	// NATUnknown represents a NAT type which is unknown.
	NATUnknown = "unknown"
	// NATRestricted represents a restricted NAT.
	NATRestricted = "restricted"
	// NATUnrestricted represents an unrestricted NAT.
	NATUnrestricted = "unrestricted"
)

const DefaultBrokerURL = "https://snowflake-broker.torproject.net/"

const DefaultNATProbeURL = "https://snowflake-broker.torproject.net:8443/probe"

const DefaultProxyType = "standalone"

const DefaultRelayURL = "wss://snowflake.bamsoftware.com/"

const DefaultSTUNURL = "stun:stun.l.google.com:19302"

Functions

func NewProxyEventLogger

func NewProxyEventLogger(logPeriod time.Duration, output io.Writer) event.SnowflakeEventReceiver

Types

type SignalingServer

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

SignalingServer keeps track of the SignalingServer in use by the Snowflake

func (*SignalingServer) Post

func (s *SignalingServer) Post(path string, payload io.Reader) ([]byte, error)

Post sends a POST request to the SignalingServer

type SnowflakeProxy

type SnowflakeProxy struct {
	// Capacity is the maximum number of clients a Snowflake will serve.
	// Proxies with a capacity of 0 will accept an unlimited number of clients.
	Capacity uint
	// STUNURL is the URL of the STUN server the proxy will use
	STUNURL string
	// BrokerURL is the URL of the Snowflake broker
	BrokerURL string
	// KeepLocalAddresses indicates whether local SDP candidates will be sent to the broker
	KeepLocalAddresses bool
	// RelayURL is the URL of the Snowflake server that all traffic will be relayed to
	RelayURL string
	// Ephemeral*Port limits the pool of ports that ICE UDP connections can allocate from
	EphemeralMinPort uint16
	EphemeralMaxPort uint16
	// RelayDomainNamePattern is the pattern specify allowed domain name for relay
	// If the pattern starts with ^ then an exact match is required.
	// The rest of pattern is the suffix of domain name.
	// There is no look ahead assertion when matching domain name suffix,
	// thus the string prepend the suffix does not need to be empty or ends with a dot.
	RelayDomainNamePattern string
	AllowNonTLSRelay       bool
	// NATProbeURL is the URL of the probe service we use for NAT checks
	NATProbeURL string
	// NATTypeMeasurementInterval is time before NAT type is retested
	NATTypeMeasurementInterval time.Duration
	// ProxyType is the type reported to the broker, if not provided it "standalone" will be used
	ProxyType       string
	EventDispatcher event.SnowflakeEventDispatcher
	// contains filtered or unexported fields
}

SnowflakeProxy is used to configure an embedded Snowflake in another Go application.

func (*SnowflakeProxy) Start

func (sf *SnowflakeProxy) Start() error

Start configures and starts a Snowflake, fully formed and special. Configuration values that are unset will default to their corresponding default values.

func (*SnowflakeProxy) Stop

func (sf *SnowflakeProxy) Stop()

Stop closes all existing connections and shuts down the Snowflake.