type BIRDClient interface {EnableProtocol(protostring)errorDisableProtocol(protostring)errorClose()error}

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.Tuntun.Device// IsTAP is whether Tun is actually a TAP (Layer 2) device that'll// require ethernet headers.IsTAPbool// Router interfaces the Engine to the OS network stack.// If nil, a fake Router that does nothing is used.Routerrouter.Router// DNS interfaces the Engine to the OS DNS resolver configuration.// If nil, a fake OSConfigurator that does nothing is used.DNSdns.OSConfigurator// ReconfigureVPN provides an optional hook for platforms like Android to// know when it's time to reconfigure their VPN implementation. Such// platforms can only set their entire VPN configuration (routes, DNS, etc)// at all once and can't make piecemeal incremental changes, so this// provides a hook to "flush" a batch of Router and/or DNS changes.ReconfigureVPN func()error// NetMon optionally provides an existing network monitor to re-use.// If nil, a new network monitor is created.NetMon *netmon.Monitor// HealthTracker, if non-nil, is the health tracker to use.HealthTracker *health.Tracker// Metrics is the usermetrics registry to use.// Mandatory, if not set, an error is returned.Metrics *usermetric.Registry// Dialer is the dialer to use for outbound connections.// If nil, a new Dialer is created.Dialer *tsdial.Dialer// ControlKnobs is the set of control plane-provied knobs// to use.// If nil, defaults are used.ControlKnobs *controlknobs.Knobs// ListenPort is the port on which the engine will listen.// If zero, a port is automatically selected.ListenPortuint16// RespondToPing determines whether this engine should internally// reply to ICMP pings, without involving the OS.// Used in "fake" mode for development.RespondToPingbool// BIRDClient, if non-nil, will be used to configure BIRD whenever// this node is a primary subnet router.BIRDClientBIRDClient// SetSubsystem, if non-nil, is called for each new subsystem created, just before a successful return.SetSubsystem func(any)// DriveForLocal, if populated, will cause the engine to expose a Taildrive// listener at 100.100.100.100:8080.DriveForLocaldrive.FileSystemForLocal// EventBus, if non-nil, is used for event publication and subscription by// the Engine and its subsystems.//// TODO(creachadair): As of 2025-03-19 this is optional, but is intended to// become required non-nil.EventBus *eventbus.Bus}

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// ResetAndStop resets the engine to a clean state (like calling Reconfig// with all pointers to zero values) and waits for it to be fully stopped,// with no live peers or DERPs.//// Unlike Reconfig, it does not return ErrNoChanges.ResetAndStop() (*Status,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, okbool)// GetFilter returns the current packet filter, if any.GetFilter() *filter.Filter// SetFilter updates the packet filter.SetFilter(*filter.Filter)// GetJailedFilter returns the current packet filter for jailed nodes,// if any.GetJailedFilter() *filter.Filter// SetJailedFilter updates the packet filter for jailed nodes.SetJailedFilter(*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()// PeerByKey returns the WireGuard status of the provided peer.// If the peer is not found, ok is false.PeerByKey(key.NodePublic) (_wgint.Peer, okbool)// 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()// Done returns a channel that is closed when the Engine's// Close method is called, the engine aborts with an error,// or it shuts down due to the closure of the underlying device.// You don't have to call this.Done() <-chan struct{}// 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)// 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(ipnetip.Addr, pingTypetailcfg.PingType, sizeint, cb func(*ipnstate.PingResult))// 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(packet.CaptureCallback)}

funcNewFakeUserspaceEngine¶

func NewFakeUserspaceEngine(logflogger.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.

funcNewUserspaceEngine¶

func NewUserspaceEngine(logflogger.Logf, confConfig) (_Engine, reterrerror)

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

funcNewWatchdog¶

func NewWatchdog(eEngine)Engine

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

If they do not, the watchdog crashes the process.

type NetworkMapCallback func(*netmap.NetworkMap)

type PeerForIP struct {// Node is the matched node. It's always a valid value when// Engine.PeerForIP returns ok==true.Nodetailcfg.NodeView// IsSelf is whether the Node is the local process.IsSelfbool// Route is the route that matched the IP provided// to Engine.PeerForIP.Routenetip.Prefix}

type Status struct {AsOftime.Time// the time at which the status was calculatedPeers      []ipnstate.PeerStatusLiteLocalAddrs []tailcfg.Endpoint// the set of possible endpoints for the magic connDERPsint// number of active DERP connections}

type StatusCallback func(*Status,error)