Struct userspaceEngine

wgengine/userspace.go:74–165

const networkLoggerUploadTimeout = 5 * time.Second

type userspaceEngine struct {
	// eventBus will eventually become required, but for now may be nil.
	eventBus    *eventbus.Bus
	eventClient *eventbus.Client

	linkChangeQueue execqueue.ExecQueue

	logf           logger.Logf
	wgLogger       *wglog.Logger // a wireguard-go logging wrapper
	reqCh          chan struct{}
	waitCh         chan struct{} // chan is closed when first Close call completes; contrast with closing bool
	timeNow        func() mono.Time
	tundev         *tstun.Wrapper
	wgdev          *device.Device
	router         router.Router
	dialer         *tsdial.Dialer
	confListenPort uint16 // original conf.ListenPort
	dns            *dns.Manager
	magicConn      *magicsock.Conn
	netMon         *netmon.Monitor
	health         *health.Tracker
	netMonOwned    bool                // whether we created netMon (and thus need to close it)
	birdClient     BIRDClient          // or nil
	controlKnobs   *controlknobs.Knobs // or nil

	testMaybeReconfigHook func()                        // for tests; if non-nil, fires if maybeReconfigWireguardLocked called
	testDiscoChangedHook  func(map[key.NodePublic]bool) // for tests; if non-nil, fires after assembling discoChanged map

	// isLocalAddr reports the whether an IP is assigned to the local
	// tunnel interface. It's used to reflect local packets
	// incorrectly sent to us.
	isLocalAddr syncs.AtomicValue[func(netip.Addr) bool]

	// isDNSIPOverTailscale reports the whether a DNS resolver's IP
	// is being routed over Tailscale.
	isDNSIPOverTailscale syncs.AtomicValue[func(netip.Addr) bool]

	wgLock sync.Mutex // serializes all wgdev operations; see lock order comment below

	// peerByIPRoute is a longest-prefix-match table built from
	// lastCfgFull.Peers AllowedIPs. It's the slow path for
	// SetPeerByIPPacketFunc, used when LocalBackend's exact-IP fast path
	// (nodeByAddr) misses — i.e. for subnet routes and exit-node default
	// routes. Built from lastCfgFull (the wireguard-filtered peer list)
	// rather than the netmap so that exit-node selection is honored: the
	// netmap has 0.0.0.0/0 in AllowedIPs for every exit-capable peer, but
	// lastCfgFull only has it for the currently-selected exit node.
	//
	// Replaced (not mutated) by maybeReconfigWireguardLocked. Read by
	// the per-packet wgdev callback without locking.
	peerByIPRoute atomic.Pointer[bart.Table[key.NodePublic]]

	lastCfgFull        wgcfg.Config
	lastRouter         *router.Config
	lastDNSConfig      dns.ConfigView    // or invalid if none
	lastIsSubnetRouter bool              // was the node a primary subnet router in the last run.
	reconfigureVPN     func() error      // or nil
	conn25PacketHooks  Conn25PacketHooks // or nil