wgengine

Documentation

Index

• Variables
• type BIRDClient
• type Config
• type Engine
  • func NewFakeUserspaceEngine(logf logger.Logf, opts ...any) (Engine, error)
  • func NewUserspaceEngine(logf logger.Logf, conf Config) (_ Engine, reterr error)
  • func NewWatchdog(e Engine) Engine
• type NetInfoCallback
• type NetworkMapCallback
• type PeerForIP
• type Status
• type StatusCallback

Variables

var ErrEngineClosing = errors.New("engine closing; no status")

var ErrNoChanges = errors.New("no changes made to Engine config")

ErrNoChanges is returned by Engine.Reconfig if no changes were made.

Types

type BIRDClient

type BIRDClient interface {
	EnableProtocol(proto string) error
	DisableProtocol(proto string) error
	Close() error
}

BIRDClient handles communication with the BIRD Internet Routing Daemon.

type Config

type Config struct {
	// Tun is the device used by the Engine to exchange packets with
	// the OS.
	// If nil, a fake Device that does nothing is used.
	Tun tun.Device

	// IsTAP is whether Tun is actually a TAP (Layer 2) device that'll
	// require ethernet headers.
	IsTAP bool

	// Router interfaces the Engine to the OS network stack.
	// If nil, a fake Router that does nothing is used.
	Router router.Router

	// DNS interfaces the Engine to the OS DNS resolver configuration.
	// If nil, a fake OSConfigurator that does nothing is used.
	DNS dns.OSConfigurator

	// NetMon optionally provides an existing network monitor to re-use.
	// If nil, a new network monitor is created.
	NetMon *netmon.Monitor

	// Dialer is the dialer to use for outbound connections.
	// If nil, a new Dialer is created
	Dialer *tsdial.Dialer

	// ListenPort is the port on which the engine will listen.
	// If zero, a port is automatically selected.
	ListenPort uint16

	// RespondToPing determines whether this engine should internally
	// reply to ICMP pings, without involving the OS.
	// Used in "fake" mode for development.
	RespondToPing bool

	// BIRDClient, if non-nil, will be used to configure BIRD whenever
	// this node is a primary subnet router.
	BIRDClient BIRDClient

	// SetSubsystem, if non-nil, is called for each new subsystem created, just before a successful return.
	SetSubsystem func(any)
}

Config is the engine configuration.

type Engine

type Engine interface {
	// Reconfig reconfigures WireGuard and makes sure it's running.
	// This also handles setting up any kernel routes.
	//
	// This is called whenever tailcontrol (the control plane)
	// sends an updated network map.
	//
	// The returned error is ErrNoChanges if no changes were made.
	Reconfig(*wgcfg.Config, *router.Config, *dns.Config) error

	// PeerForIP returns the node to which the provided IP routes,
	// if any. If none is found, (nil, false) is returned.
	PeerForIP(netip.Addr) (_ PeerForIP, ok bool)

	// GetFilter returns the current packet filter, if any.
	GetFilter() *filter.Filter

	// SetFilter updates the packet filter.
	SetFilter(*filter.Filter)

	// SetStatusCallback sets the function to call when the
	// WireGuard status changes.
	SetStatusCallback(StatusCallback)

	// RequestStatus requests a WireGuard status update right
	// away, sent to the callback registered via SetStatusCallback.
	RequestStatus()

	// Close shuts down this wireguard instance, remove any routes
	// it added, etc. To bring it up again later, you'll need a
	// new Engine.
	Close()

	// Wait waits until the Engine's Close method is called or the
	// engine aborts with an error. You don't have to call this.
	// TODO: return an error?
	Wait()

	// LinkChange informs the engine that the system network
	// link has changed.
	//
	// The isExpensive parameter is not used.
	//
	// LinkChange should be called whenever something changed with
	// the network, no matter how minor.
	//
	// Deprecated: don't use this method. It was removed shortly
	// before the Tailscale 1.6 release when we remembered that
	// Android doesn't use the Linux-based network monitor and has
	// its own mechanism that uses LinkChange. Android is the only
	// caller of this method now. Don't add more.
	LinkChange(isExpensive bool)

	// SetDERPMap controls which (if any) DERP servers are used.
	// If nil, DERP is disabled. It starts disabled until a DERP map
	// is configured.
	SetDERPMap(*tailcfg.DERPMap)

	// SetNetworkMap informs the engine of the latest network map
	// from the server. The network map's DERPMap field should be
	// ignored as as it might be disabled; get it from SetDERPMap
	// instead.
	// The network map should only be read from.
	SetNetworkMap(*netmap.NetworkMap)

	// AddNetworkMapCallback adds a function to a list of callbacks
	// that are called when the network map updates. It returns a
	// function that when called would remove the function from the
	// list of callbacks.
	AddNetworkMapCallback(NetworkMapCallback) (removeCallback func())

	// SetNetInfoCallback sets the function to call when a
	// new NetInfo summary is available.
	SetNetInfoCallback(NetInfoCallback)

	// DiscoPublicKey gets the public key used for path discovery
	// messages.
	DiscoPublicKey() key.DiscoPublic

	// UpdateStatus populates the network state using the provided
	// status builder.
	UpdateStatus(*ipnstate.StatusBuilder)

	// Ping is a request to start a ping of the given message size to the peer
	// handling the given IP, then call cb with its ping latency & method.
	//
	// If size is zero too small, it is ignored. See tailscale.PingOpts for details.
	Ping(ip netip.Addr, pingType tailcfg.PingType, size int, cb func(*ipnstate.PingResult))

	// RegisterIPPortIdentity registers a given node (identified by its
	// Tailscale IP) as temporarily having the given IP:port for whois lookups.
	// The IP:port is generally a localhost IP and an ephemeral port, used
	// while proxying connections to localhost when tailscaled is running
	// in netstack mode.
	RegisterIPPortIdentity(netip.AddrPort, netip.Addr)

	// UnregisterIPPortIdentity removes a temporary IP:port registration
	// made previously by RegisterIPPortIdentity.
	UnregisterIPPortIdentity(netip.AddrPort)

	// WhoIsIPPort looks up an IP:port in the temporary registrations,
	// and returns a matching Tailscale IP, if it exists.
	WhoIsIPPort(netip.AddrPort) (netip.Addr, bool)

	// InstallCaptureHook registers a function to be called to capture
	// packets traversing the data path. The hook can be uninstalled by
	// calling this function with a nil value.
	InstallCaptureHook(capture.Callback)
}

Engine is the Tailscale WireGuard engine interface.

func NewFakeUserspaceEngine

func NewFakeUserspaceEngine(logf logger.Logf, opts ...any) (Engine, error)

NewFakeUserspaceEngine returns a new userspace engine for testing.

The opts may contain the following types:

• int or uint16: to set the ListenPort.

func NewUserspaceEngine

func NewUserspaceEngine(logf logger.Logf, conf Config) (_ Engine, reterr error)

NewUserspaceEngine creates the named tun device and returns a Tailscale Engine running on it.

func NewWatchdog

func NewWatchdog(e Engine) Engine

NewWatchdog wraps an Engine and makes sure that all methods complete within a reasonable amount of time.

If they do not, the watchdog crashes the process.

type NetInfoCallback

type NetInfoCallback func(*tailcfg.NetInfo)

NetInfoCallback is the type used by Engine.SetNetInfoCallback.

type NetworkMapCallback

type NetworkMapCallback func(*netmap.NetworkMap)

NetworkMapCallback is the type used by callbacks that hook into network map updates.

type PeerForIP

type PeerForIP struct {
	// Node is the matched node. It's always a valid value when
	// Engine.PeerForIP returns ok==true.
	Node tailcfg.NodeView

	// IsSelf is whether the Node is the local process.
	IsSelf bool

	// Route is the route that matched the IP provided
	// to Engine.PeerForIP.
	Route netip.Prefix
}

PeerForIP is the type returned by Engine.PeerForIP.

type Status

type Status struct {
	AsOf       time.Time // the time at which the status was calculated
	Peers      []ipnstate.PeerStatusLite
	LocalAddrs []tailcfg.Endpoint // the set of possible endpoints for the magic conn
	DERPs      int                // number of active DERP connections
}

Status is the Engine status.

TODO(bradfitz): remove this, subset of ipnstate? Need to migrate users.

type StatusCallback

type StatusCallback func(*Status, error)

StatusCallback is the type of status callbacks used by Engine.SetStatusCallback.

Exactly one of Status or error is non-nil.