Move Linux client & common packages into a public repo.

ipn/backend.go

@@ -0,0 +1,79 @@
+// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ipn
+
+import (
+	"tailscale.com/control/controlclient"
+	"tailscale.com/tailcfg"
+	"tailscale.com/wgengine"
+	"time"
+)
+
+type State int
+
+const (
+	NoState = State(iota)
+	NeedsLogin
+	NeedsMachineAuth
+	Stopped
+	Starting
+	Running
+)
+
+func (s State) String() string {
+	return [...]string{"NoState", "NeedsLogin", "NeedsMachineAuth",
+		"Stopped", "Starting", "Running"}[s]
+}
+
+type EngineStatus struct {
+	RBytes, WBytes wgengine.ByteCount
+	NumLive        int
+	LivePeers      map[tailcfg.NodeKey]wgengine.PeerStatus
+}
+
+type NetworkMap = controlclient.NetworkMap
+
+// In any given notification, any or all of these may be nil, meaning
+// that they have not changed.
+type Notify struct {
+	Version       string        // version number of IPN backend
+	ErrMessage    *string       // critical error message, if any
+	LoginFinished *struct{}     // event: login process succeeded
+	State         *State        // current IPN state has changed
+	Prefs         *Prefs        // preferences were changed
+	NetMap        *NetworkMap   // new netmap received
+	Engine        *EngineStatus // wireguard engine stats
+	BrowseToURL   *string       // UI should open a browser right now
+	BackendLogID  *string       // public logtail id used by backend
+}
+
+type Options struct {
+	FrontendLogID string // public logtail id used by frontend
+	ServerURL     string
+	Prefs         Prefs
+	LoginFlags    controlclient.LoginFlags
+	Notify        func(n Notify) `json:"-"`
+}
+
+type Backend interface {
+	// Start or restart the backend, because a new Handle has connected.
+	Start(opts Options) error
+	// Start a new interactive login. This should trigger a new
+	// BrowseToURL notification eventually.
+	StartLoginInteractive()
+	// Terminate the current login session and stop the wireguard engine.
+	Logout()
+	// Install a new set of user preferences, including WantRunning.
+	// This may cause the wireguard engine to reconfigure or stop.
+	SetPrefs(new Prefs)
+	// Poll for an update from the wireguard engine. Only needed if
+	// you want to display byte counts. Connection events are emitted
+	// automatically without polling.
+	RequestEngineStatus()
+	// Pretend the current key is going to expire after duration x.
+	// This is useful for testing GUIs to make sure they react properly
+	// with keys that are going to expire.
+	FakeExpireAfter(x time.Duration)
+}