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tailscale/ipn/backend.go

250 lines
8.5 KiB
Go

// 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 (
"fmt"
"strings"
"time"
"tailscale.com/ipn/ipnstate"
"tailscale.com/tailcfg"
"tailscale.com/types/empty"
"tailscale.com/types/key"
"tailscale.com/types/netmap"
"tailscale.com/types/structs"
)
type State int
const (
NoState = State(iota)
InUseOtherUser
NeedsLogin
NeedsMachineAuth
Stopped
Starting
Running
)
// GoogleIDToken Type is the tailcfg.Oauth2Token.TokenType for the Google
// ID tokens used by the Android client.
const GoogleIDTokenType = "ts_android_google_login"
func (s State) String() string {
return [...]string{
"NoState",
"InUseOtherUser",
"NeedsLogin",
"NeedsMachineAuth",
"Stopped",
"Starting",
"Running"}[s]
}
// EngineStatus contains WireGuard engine stats.
type EngineStatus struct {
RBytes, WBytes int64
NumLive int
LiveDERPs int // number of active DERP connections
LivePeers map[key.NodePublic]ipnstate.PeerStatusLite
}
// Notify is a communication from a backend (e.g. tailscaled) to a frontend
// (cmd/tailscale, iOS, macOS, Win Tasktray).
// In any given notification, any or all of these may be nil, meaning
// that they have not changed.
// They are JSON-encoded on the wire, despite the lack of struct tags.
type Notify struct {
_ structs.Incomparable
Version string // version number of IPN backend
// ErrMessage, if non-nil, contains a critical error message.
// For State InUseOtherUser, ErrMessage is not critical and just contains the details.
ErrMessage *string
LoginFinished *empty.Message // non-nil when/if the login process succeeded
State *State // if non-nil, the new or current IPN state
Prefs PrefsView // if Valid, the new or current preferences
NetMap *netmap.NetworkMap // if non-nil, the new or current netmap
Engine *EngineStatus // if non-nil, the new or current wireguard stats
BrowseToURL *string // if non-nil, UI should open a browser right now
BackendLogID *string // if non-nil, the public logtail ID used by backend
// FilesWaiting if non-nil means that files are buffered in
// the Tailscale daemon and ready for local transfer to the
// user's preferred storage location.
FilesWaiting *empty.Message `json:",omitempty"`
// IncomingFiles, if non-nil, specifies which files are in the
// process of being received. A nil IncomingFiles means this
// Notify should not update the state of file transfers. A non-nil
// but empty IncomingFiles means that no files are in the middle
// of being transferred.
IncomingFiles []PartialFile `json:",omitempty"`
// LocalTCPPort, if non-nil, informs the UI frontend which
// (non-zero) localhost TCP port it's listening on.
// This is currently only used by Tailscale when run in the
// macOS Network Extension.
LocalTCPPort *uint16 `json:",omitempty"`
// type is mirrored in xcode/Shared/IPN.swift
}
func (n Notify) String() string {
var sb strings.Builder
sb.WriteString("Notify{")
if n.ErrMessage != nil {
fmt.Fprintf(&sb, "err=%q ", *n.ErrMessage)
}
if n.LoginFinished != nil {
sb.WriteString("LoginFinished ")
}
if n.State != nil {
fmt.Fprintf(&sb, "state=%v ", *n.State)
}
if n.Prefs.Valid() {
fmt.Fprintf(&sb, "%v ", n.Prefs.Pretty())
}
if n.NetMap != nil {
sb.WriteString("NetMap{...} ")
}
if n.Engine != nil {
fmt.Fprintf(&sb, "wg=%v ", *n.Engine)
}
if n.BrowseToURL != nil {
sb.WriteString("URL=<...> ")
}
if n.BackendLogID != nil {
sb.WriteString("BackendLogID ")
}
if n.FilesWaiting != nil {
sb.WriteString("FilesWaiting ")
}
if len(n.IncomingFiles) != 0 {
sb.WriteString("IncomingFiles ")
}
if n.LocalTCPPort != nil {
fmt.Fprintf(&sb, "tcpport=%v ", n.LocalTCPPort)
}
s := sb.String()
return s[0:len(s)-1] + "}"
}
// PartialFile represents an in-progress file transfer.
type PartialFile struct {
Name string // e.g. "foo.jpg"
Started time.Time // time transfer started
DeclaredSize int64 // or -1 if unknown
Received int64 // bytes copied thus far
// PartialPath is set non-empty in "direct" file mode to the
// in-progress '*.partial' file's path when the peerapi isn't
// being used; see LocalBackend.SetDirectFileRoot.
PartialPath string `json:",omitempty"`
// Done is set in "direct" mode when the partial file has been
// closed and is ready for the caller to rename away the
// ".partial" suffix.
Done bool `json:",omitempty"`
}
// StateKey is an opaque identifier for a set of LocalBackend state
// (preferences, private keys, etc.).
//
// The reason we need this is that the Tailscale agent may be running
// on a multi-user machine, in a context where a single daemon is
// shared by several consecutive users. Ideally we would just use the
// username of the connected frontend as the StateKey.
//
// Various platforms currently set StateKey in different ways:
//
// - the macOS/iOS GUI apps set it to "ipn-go-bridge"
// - the Android app sets it to "ipn-android"
// - on Windows, it's the empty string (in client mode) or, via
// LocalBackend.userID, a string like "user-$USER_ID" (used in
// server mode).
// - on Linux/etc, it's always "_daemon" (ipn.GlobalDaemonStateKey)
//
// Additionally, the StateKey can be debug setting name:
//
// - "_debug_magicsock_until" with value being a unix timestamp stringified
// - "_debug_<component>_until" with value being a unix timestamp stringified
type StateKey string
type Options struct {
// FrontendLogID is the public logtail id used by the frontend.
FrontendLogID string
// StateKey and Prefs together define the state the backend should
// use:
// - StateKey=="" && Prefs!=nil: use Prefs for internal state,
// don't persist changes in the backend, except for the machine key
// for migration purposes.
// - StateKey!="" && Prefs==nil: load the given backend-side
// state and use/update that.
// - StateKey!="" && Prefs!=nil: like the previous case, but do
// an initial overwrite of backend state with Prefs.
//
// NOTE(apenwarr): The above means that this Prefs field does not do
// what you probably think it does. It will overwrite your encryption
// keys. Do not use unless you know what you're doing.
StateKey StateKey
Prefs *Prefs
// UpdatePrefs, if provided, overrides Options.Prefs *and* the Prefs
// already stored in the backend state, *except* for the Persist
// Persist member. If you just want to provide prefs, this is
// probably what you want.
//
// UpdatePrefs.Persist is always ignored. Prefs.Persist will still
// be used even if UpdatePrefs is provided. Other than Persist,
// UpdatePrefs takes precedence over Prefs.
//
// This is intended as a purely temporary workaround for the
// currently unexpected behaviour of Options.Prefs.
//
// TODO(apenwarr): Remove this, or rename Prefs to something else
// and rename this to Prefs. Or, move Prefs.Persist elsewhere
// entirely (as it always should have been), and then we wouldn't
// need two separate fields at all. Or, move the fancy state
// migration stuff out of Start().
UpdatePrefs *Prefs
// AuthKey is an optional node auth key used to authorize a
// new node key without user interaction.
AuthKey string
}
// Backend is the interface between Tailscale frontends
// (e.g. cmd/tailscale, iOS/MacOS/Windows GUIs) and the tailscale
// backend (e.g. cmd/tailscaled) running on the same machine.
// (It has nothing to do with the interface between the backends
// and the cloud control plane.)
type Backend interface {
// SetNotifyCallback sets the callback to be called on updates
// from the backend to the client.
SetNotifyCallback(func(Notify))
// Start starts or restarts the backend, typically when a
// frontend client connects.
Start(Options) error
// StartLoginInteractive requests to start a new interactive login
// flow. This should trigger a new BrowseToURL notification
// eventually.
StartLoginInteractive()
// Login logs in with an OAuth2 token.
Login(token *tailcfg.Oauth2Token)
// Logout terminates the current login session and stops the
// wireguard engine.
Logout()
// SetPrefs installs a new set of user preferences, including
// WantRunning. This may cause the wireguard engine to
// reconfigure or stop.
SetPrefs(*Prefs)
// RequestEngineStatus polls for an update from the wireguard
// engine. Only needed if you want to display byte
// counts. Connection events are emitted automatically without
// polling.
RequestEngineStatus()
}