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tailscale-android/cmd/tailscale/main.go

1697 lines
46 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 main
import (
"cmp"
"context"
"crypto/rand"
"crypto/sha1"
"encoding/hex"
"errors"
"fmt"
"io"
"log"
"mime"
"net"
"net/http"
"net/netip"
"net/url"
"os"
"path/filepath"
"sort"
"strings"
"sync/atomic"
"time"
"unsafe"
"gioui.org/app"
"gioui.org/io/key"
"gioui.org/io/system"
"gioui.org/layout"
"gioui.org/op"
"golang.org/x/exp/maps"
"inet.af/netaddr"
"github.com/tailscale/tailscale-android/cmd/jni"
"github.com/tailscale/tailscale-android/cmd/localapiservice"
"tailscale.com/client/tailscale/apitype"
"tailscale.com/hostinfo"
"tailscale.com/ipn"
"tailscale.com/ipn/ipnlocal"
"tailscale.com/ipn/localapi"
"tailscale.com/net/dns"
"tailscale.com/net/interfaces"
"tailscale.com/net/netns"
"tailscale.com/paths"
"tailscale.com/tailcfg"
"tailscale.com/types/logid"
"tailscale.com/types/netmap"
"tailscale.com/util/syspolicy"
"tailscale.com/wgengine/router"
)
type App struct {
jvm *jni.JVM
// appCtx is a global reference to the com.tailscale.ipn.App instance.
appCtx jni.Object
store *stateStore
logIDPublicAtomic atomic.Pointer[logid.PublicID]
localAPI *localapiservice.LocalAPIService
backend *ipnlocal.LocalBackend
// netStates receives the most recent network state.
netStates chan BackendState
// prefs receives new preferences from the backend.
prefs chan *ipn.Prefs
// browseURLs receives URLs when the backend wants to browse.
browseURLs chan string
// targetsLoaded receives lists of file targets.
targetsLoaded chan FileTargets
// invalidates receives whenever the window should be refreshed.
invalidates chan struct{}
// bugReport receives the bug report from the backend's localapi call
bugReport chan string
}
var (
// googleClass is a global reference to the com.tailscale.ipn.Google class.
googleClass jni.Class
)
type FileTargets struct {
Targets []*apitype.FileTarget
Err error
}
type File struct {
Type FileType
Name string
Size int64
MIMEType string
// URI of the file, valid if Type is FileTypeURI.
URI string
// Text is the content of the file, if Type is FileTypeText.
Text string
}
// FileSendInfo describes the state of an ongoing file send operation.
type FileSendInfo struct {
State FileSendState
// Progress tracks the progress of the transfer from 0.0 to 1.0. Valid
// only when State is FileSendStarted.
Progress float64
}
type clientState struct {
browseURL string
backend BackendState
// query is the search query, in lowercase.
query string
Peers []UIPeer
}
type FileType uint8
// FileType constants are known to IPNActivity.java.
const (
FileTypeText FileType = 1
FileTypeURI FileType = 2
)
type ExitStatus uint8
const (
// No exit node selected.
ExitNone ExitStatus = iota
// Exit node selected and exists, but is offline or missing.
ExitOffline
// Exit node selected and online.
ExitOnline
)
type FileSendState uint8
const (
FileSendNotStarted FileSendState = iota
FileSendConnecting
FileSendTransferring
FileSendComplete
FileSendFailed
)
type Peer struct {
Label string
Online bool
ID tailcfg.StableNodeID
Location *tailcfg.Location
PreferredExitNode bool
}
type BackendState struct {
Prefs *ipn.Prefs
State ipn.State
NetworkMap *netmap.NetworkMap
LostInternet bool
// Exits are the peers that can act as exit node.
Exits []Peer
// ExitState describes the state of our exit node.
ExitStatus ExitStatus
// Exit is our current exit node, if any.
Exit Peer
}
// UIEvent is an event flowing from the UI to the backend.
type UIEvent interface{}
type RouteAllEvent struct {
ID tailcfg.StableNodeID
}
type ConnectEvent struct {
Enable bool
SettingsRestoreEvent
}
type CopyEvent struct {
Text string
}
type SearchEvent struct {
Query string
}
type OAuth2Event struct {
Token *tailcfg.Oauth2Token
}
type FileSendEvent struct {
Target *apitype.FileTarget
Context context.Context
Updates func(FileSendInfo)
}
type SetLoginServerEvent struct {
URL string
}
type WebAuthEvent struct {
SettingsRestoreEvent
}
// UIEvent types.
type (
ReauthEvent struct{}
BugEvent struct{}
GoogleAuthEvent struct{}
LogoutEvent struct{}
OSSLicensesEvent struct{}
BeExitNodeEvent bool
ExitAllowLANEvent bool
)
// RestoreEvent represents an event that might restore user settings persisted across sessions.
type RestoreEvent interface {
SetURL(url string)
GetURL() string
SetExitNodeID(exitNodeID tailcfg.StableNodeID)
GetExitNodeID() tailcfg.StableNodeID
SetExitAllowLAN(allowLAN bool)
GetExitAllowLAN() bool
}
type SettingsRestoreEvent struct {
// Custom server login URL
URL string
ExitNodeID tailcfg.StableNodeID
ExitAllowLAN bool
}
func (e *SettingsRestoreEvent) SetURL(url string) {
e.URL = url
}
func (e *SettingsRestoreEvent) GetURL() string {
return e.URL
}
func (e *SettingsRestoreEvent) SetExitNodeID(exitNodeID tailcfg.StableNodeID) {
e.ExitNodeID = exitNodeID
}
func (e *SettingsRestoreEvent) GetExitNodeID() tailcfg.StableNodeID {
return e.ExitNodeID
}
func (e *SettingsRestoreEvent) SetExitAllowLAN(allowLAN bool) {
e.ExitAllowLAN = allowLAN
}
func (e *SettingsRestoreEvent) GetExitAllowLAN() bool {
return e.ExitAllowLAN
}
// serverOAuthID is the OAuth ID of the tailscale-android server, used
// by GoogleSignInOptions.Builder.requestIdToken.
const serverOAuthID = "744055068597-hv4opg0h7vskq1hv37nq3u26t8c15qk0.apps.googleusercontent.com"
// releaseCertFingerprint is the SHA-1 fingerprint of the Google Play Store signing key.
// It is used to check whether the app is signed for release.
const releaseCertFingerprint = "86:9D:11:8B:63:1E:F8:35:C6:D9:C2:66:53:BC:28:22:2F:B8:C1:AE"
// backendEvents receives events from the UI (Activity, Tile etc.) to the backend.
var backendEvents = make(chan UIEvent)
func main() {
a := &App{
jvm: (*jni.JVM)(unsafe.Pointer(app.JavaVM())),
appCtx: jni.Object(app.AppContext()),
netStates: make(chan BackendState, 1),
browseURLs: make(chan string, 1),
prefs: make(chan *ipn.Prefs, 1),
targetsLoaded: make(chan FileTargets, 1),
invalidates: make(chan struct{}, 1),
bugReport: make(chan string, 1),
}
err := a.loadJNIGlobalClassRefs()
if err != nil {
fatalErr(err)
}
a.store = newStateStore(a.jvm, a.appCtx)
interfaces.RegisterInterfaceGetter(a.getInterfaces)
syspolicy.RegisterHandler(androidHandler{a: a})
go func() {
ctx := context.Background()
if err := a.runBackend(ctx); err != nil {
fatalErr(err)
}
}()
go func() {
if err := a.runUI(); err != nil {
fatalErr(err)
}
}()
app.Main()
}
// Loads the global JNI class references. Failures here are fatal if the
// class ref is required for the app to function.
func (a *App) loadJNIGlobalClassRefs() error {
return jni.Do(a.jvm, func(env *jni.Env) error {
loader := jni.ClassLoaderFor(env, a.appCtx)
cl, err := jni.LoadClass(env, loader, "com.tailscale.ipn.Google")
if err != nil {
// Ignore load errors; the Google class is not included in F-Droid builds.
return nil
}
googleClass = jni.Class(jni.NewGlobalRef(env, jni.Object(cl)))
return nil
})
}
func (a *App) runBackend(ctx context.Context) error {
appDir, err := app.DataDir()
if err != nil {
fatalErr(err)
}
paths.AppSharedDir.Store(appDir)
hostinfo.SetOSVersion(a.osVersion())
if !googleSignInEnabled() {
hostinfo.SetPackage("nogoogle")
}
deviceModel := a.modelName()
if a.isChromeOS() {
deviceModel = "ChromeOS: " + deviceModel
}
hostinfo.SetDeviceModel(deviceModel)
type configPair struct {
rcfg *router.Config
dcfg *dns.OSConfig
}
configs := make(chan configPair)
configErrs := make(chan error)
b, err := newBackend(appDir, a.jvm, a.appCtx, a.store, func(rcfg *router.Config, dcfg *dns.OSConfig) error {
if rcfg == nil {
return nil
}
configs <- configPair{rcfg, dcfg}
return <-configErrs
})
if err != nil {
return err
}
a.logIDPublicAtomic.Store(&b.logIDPublic)
a.backend = b.backend
defer b.CloseTUNs()
h := localapi.NewHandler(b.backend, log.Printf, b.sys.NetMon.Get(), *a.logIDPublicAtomic.Load())
h.PermitRead = true
h.PermitWrite = true
a.localAPI = localapiservice.New(h)
localapiservice.ConfigureShim(a.jvm, a.appCtx, a.localAPI, b.backend)
// Contrary to the documentation for VpnService.Builder.addDnsServer,
// ChromeOS doesn't fall back to the underlying network nameservers if
// we don't provide any.
b.avoidEmptyDNS = a.isChromeOS()
var timer *time.Timer
var alarmChan <-chan time.Time
alarm := func(t *time.Timer) {
if timer != nil {
timer.Stop()
}
timer = t
if timer != nil {
alarmChan = timer.C
}
}
notifications := make(chan ipn.Notify, 1)
startErr := make(chan error)
// Start from a goroutine to avoid deadlock when Start
// calls the callback.
go func() {
startErr <- b.Start(func(n ipn.Notify) {
notifications <- n
})
}()
var (
cfg configPair
state BackendState
service jni.Object // of IPNService
signingIn bool
)
var (
waitingFilesDone = make(chan struct{})
waitingFiles bool
processingFiles bool
)
processFiles := func() {
if !waitingFiles || processingFiles {
return
}
processingFiles = true
waitingFiles = false
go func() {
if err := a.processWaitingFiles(b.backend); err != nil {
log.Printf("processWaitingFiles: %v", err)
}
waitingFilesDone <- struct{}{}
}()
}
for {
select {
case err := <-startErr:
if err != nil {
return err
}
case <-waitingFilesDone:
processingFiles = false
processFiles()
case s := <-configs:
cfg = s
if b == nil || service == 0 || cfg.rcfg == nil {
configErrs <- nil
break
}
configErrs <- b.updateTUN(service, cfg.rcfg, cfg.dcfg)
case n := <-notifications:
exitWasOnline := state.ExitStatus == ExitOnline
if p := n.Prefs; p != nil && n.Prefs.Valid() {
state.Prefs = p.AsStruct()
state.updateExitNodes()
a.setPrefs(state.Prefs)
}
first := state.Prefs == nil
if first {
state.Prefs = ipn.NewPrefs()
state.Prefs.Hostname = a.hostname()
go b.backend.SetPrefs(state.Prefs)
a.setPrefs(state.Prefs)
}
if s := n.State; s != nil {
oldState := state.State
state.State = *s
if service != 0 {
if cfg.rcfg != nil && state.State >= ipn.Starting {
if err := b.updateTUN(service, cfg.rcfg, cfg.dcfg); err != nil {
if errors.Is(err, errMultipleUsers) {
a.pushNotify(service, "Multiple Users", multipleUsersText)
}
log.Printf("VPN update failed: %v", err)
notifyVPNClosed()
}
} else {
b.CloseTUNs()
}
}
// Stop VPN if we logged out.
if oldState > ipn.Stopped && state.State <= ipn.Stopped {
if err := a.callVoidMethod(a.appCtx, "stopVPN", "()V"); err != nil {
fatalErr(err)
}
}
a.notify(state)
if service != 0 {
a.updateNotification(service, state.State, state.ExitStatus, state.Exit)
}
}
if u := n.BrowseToURL; u != nil {
signingIn = false
a.setURL(*u)
}
if m := n.NetMap; m != nil {
state.NetworkMap = m
state.updateExitNodes()
a.notify(state)
if service != 0 {
alarm(a.notifyExpiry(service, m.Expiry))
}
}
// Notify if a previously online exit is not longer online (or missing).
if service != 0 && exitWasOnline && state.ExitStatus == ExitOffline {
a.pushNotify(service, "Connection Lost", "Your exit node is offline. Disable your exit node or contact your network admin for help.")
}
targets, err := b.backend.FileTargets()
if err != nil {
// Construct a user-visible error message.
if b.backend.State() != ipn.Running {
err = fmt.Errorf("Not connected to tailscale")
} else {
err = fmt.Errorf("Failed to load device list")
}
}
a.targetsLoaded <- FileTargets{targets, err}
waitingFiles = n.FilesWaiting != nil
processFiles()
case <-onWriteStorageGranted:
processFiles()
case <-alarmChan:
if m := state.NetworkMap; m != nil && service != 0 {
alarm(a.notifyExpiry(service, m.Expiry))
}
case e := <-backendEvents:
switch e := e.(type) {
case BugEvent:
backendLogIDStr := a.logIDPublicAtomic.Load().String()
fallbackLog := fmt.Sprintf("BUG-%v-%v-%v", backendLogIDStr, time.Now().UTC().Format("20060102150405Z"), randHex(8))
a.localAPI.GetBugReportID(ctx, a.bugReport, fallbackLog)
case OAuth2Event:
go b.backend.Login(e.Token)
case BeExitNodeEvent:
state.Prefs.SetAdvertiseExitNode(bool(e))
go b.backend.SetPrefs(state.Prefs)
case ExitAllowLANEvent:
state.Prefs.ExitNodeAllowLANAccess = bool(e)
a.store.WriteBool(exitAllowLANPrefKey, true)
go b.backend.SetPrefs(state.Prefs)
case WebAuthEvent:
if !signingIn {
setCustomServer, setExitNode, setAllowLANAccess := a.restoreSettings(&e, state, service)
signingIn = true
go func() {
if setCustomServer || setExitNode || setAllowLANAccess {
b.backend.SetPrefs(state.Prefs)
}
if setCustomServer {
// Need to restart to force the login URL to be regenerated
// with the new control URL. Start from a goroutine to avoid
// deadlock.
err := b.backend.Start(ipn.Options{})
if err != nil {
fatalErr(err)
}
}
b.backend.StartLoginInteractive()
}()
}
case SetLoginServerEvent:
state.Prefs.ControlURL = e.URL
a.store.WriteString(customLoginServerPrefKey, e.URL)
b.backend.SetPrefs(state.Prefs)
// Need to restart to force the login URL to be regenerated
// with the new control URL. Start from a goroutine to avoid
// deadlock.
go func() {
err := b.backend.Start(ipn.Options{})
if err != nil {
fatalErr(err)
}
}()
case LogoutEvent:
go a.localAPI.Logout(ctx, a.backend)
case ConnectEvent:
first := state.Prefs == nil
// A ConnectEvent might be sent before the first notification
// arrives, such as in the case of Always-on VPN.
if first {
state.Prefs = ipn.NewPrefs()
}
state.Prefs.WantRunning = e.Enable
setCustomServer, _, _ := a.restoreSettings(&e, state, service)
go func() {
b.backend.SetPrefs(state.Prefs)
if setCustomServer {
// Need to restart to force the login URL to be regenerated
// with the new control URL. Start from a goroutine to avoid
// deadlock.
err := b.backend.Start(ipn.Options{})
if err != nil {
fatalErr(err)
}
}
}()
case RouteAllEvent:
state.Prefs.ExitNodeID = e.ID
go b.backend.SetPrefs(state.Prefs)
a.store.WriteString(exitNodePrefKey, string(e.ID))
state.updateExitNodes()
a.notify(state)
if service != 0 {
a.updateNotification(service, state.State, state.ExitStatus, state.Exit)
}
}
case s := <-onVPNRequested:
jni.Do(a.jvm, func(env *jni.Env) error {
if jni.IsSameObject(env, s, service) {
// We already have a reference.
jni.DeleteGlobalRef(env, s)
return nil
}
if service != 0 {
jni.DeleteGlobalRef(env, service)
}
netns.SetAndroidProtectFunc(func(fd int) error {
return jni.Do(a.jvm, func(env *jni.Env) error {
// Call https://developer.android.com/reference/android/net/VpnService#protect(int)
// to mark fd as a socket that should bypass the VPN and use the underlying network.
cls := jni.GetObjectClass(env, s)
m := jni.GetMethodID(env, cls, "protect", "(I)Z")
ok, err := jni.CallBooleanMethod(env, s, m, jni.Value(fd))
// TODO(bradfitz): return an error back up to netns if this fails, once
// we've had some experience with this and analyzed the logs over a wide
// range of Android phones. For now we're being paranoid and conservative
// and do the JNI call to protect best effort, only logging if it fails.
// The risk of returning an error is that it breaks users on some Android
// versions even when they're not using exit nodes. I'd rather the
// relatively few number of exit node users file bug reports if Tailscale
// doesn't work and then we can look for this log print.
if err != nil || !ok {
log.Printf("[unexpected] VpnService.protect(%d) = %v, %v", fd, ok, err)
}
return nil // even on error. see big TODO above.
})
})
log.Printf("onVPNRequested: rebind required")
// TODO(catzkorn): When we start the android application
// we bind sockets before we have access to the VpnService.protect()
// function which is needed to avoid routing loops. When we activate
// the service we get access to the protect, but do not retrospectively
// protect the sockets already opened, which breaks connectivity.
// As a temporary fix, we rebind and protect the magicsock.Conn on connect
// which restores connectivity.
// See https://github.com/tailscale/corp/issues/13814
b.backend.DebugRebind()
service = s
return nil
})
a.updateNotification(service, state.State, state.ExitStatus, state.Exit)
if m := state.NetworkMap; m != nil {
alarm(a.notifyExpiry(service, m.Expiry))
}
if cfg.rcfg != nil && state.State >= ipn.Starting {
if err := b.updateTUN(service, cfg.rcfg, cfg.dcfg); err != nil {
log.Printf("VPN update failed: %v", err)
notifyVPNClosed()
}
}
case s := <-onDisconnect:
b.CloseTUNs()
jni.Do(a.jvm, func(env *jni.Env) error {
defer jni.DeleteGlobalRef(env, s)
if jni.IsSameObject(env, service, s) {
netns.SetAndroidProtectFunc(nil)
jni.DeleteGlobalRef(env, service)
service = 0
}
return nil
})
if state.State >= ipn.Starting {
notifyVPNClosed()
}
case <-onDNSConfigChanged:
if b != nil {
go b.NetworkChanged()
}
a.notify(state)
}
}
}
func (a *App) restoreSettings(e RestoreEvent, state BackendState, service jni.Object) (bool, bool, bool) {
var setCustomServer bool
var setExitNode bool
var setAllowLANAccess bool
if URL := e.GetURL(); URL != "" {
state.Prefs.ControlURL = URL
setCustomServer = true
}
if nodeID := e.GetExitNodeID(); nodeID != "" {
state.Prefs.ExitNodeID = nodeID
state.updateExitNodes()
a.notify(state)
if service != 0 {
a.updateNotification(service, state.State, state.ExitStatus, state.Exit)
}
setExitNode = true
}
if e.GetExitAllowLAN() {
state.Prefs.ExitNodeAllowLANAccess = true
}
return setCustomServer, setExitNode, setAllowLANAccess
}
func (a *App) processWaitingFiles(b *ipnlocal.LocalBackend) error {
files, err := b.WaitingFiles()
if err != nil {
return err
}
var aerr error
for _, f := range files {
if err := a.downloadFile(b, f); err != nil && aerr == nil {
aerr = err
}
}
return aerr
}
func (a *App) downloadFile(b *ipnlocal.LocalBackend, f apitype.WaitingFile) (cerr error) {
in, _, err := b.OpenFile(f.Name)
if err != nil {
return err
}
defer in.Close()
ext := filepath.Ext(f.Name)
mimeType := mime.TypeByExtension(ext)
var mediaURI string
err = jni.Do(a.jvm, func(env *jni.Env) error {
cls := jni.GetObjectClass(env, a.appCtx)
insertMedia := jni.GetMethodID(env, cls, "insertMedia", "(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;")
jname := jni.JavaString(env, f.Name)
jmime := jni.JavaString(env, mimeType)
uri, err := jni.CallObjectMethod(env, a.appCtx, insertMedia, jni.Value(jname), jni.Value(jmime))
if err != nil {
return err
}
mediaURI = jni.GoString(env, jni.String(uri))
return nil
})
if err != nil {
return fmt.Errorf("insertMedia: %w", err)
}
deleteURI := func(uri string) error {
return jni.Do(a.jvm, func(env *jni.Env) error {
cls := jni.GetObjectClass(env, a.appCtx)
m := jni.GetMethodID(env, cls, "deleteUri", "(Ljava/lang/String;)V")
juri := jni.JavaString(env, uri)
return jni.CallVoidMethod(env, a.appCtx, m, jni.Value(juri))
})
}
out, err := a.openURI(mediaURI, "w")
if err != nil {
deleteURI(mediaURI)
return fmt.Errorf("openUri: %w", err)
}
if _, err := io.Copy(out, in); err != nil {
deleteURI(mediaURI)
return fmt.Errorf("copy: %w", err)
}
if err := out.Close(); err != nil {
deleteURI(mediaURI)
return fmt.Errorf("close: %w", err)
}
if err := a.notifyFile(mediaURI, f.Name); err != nil {
fatalErr(err)
}
return b.DeleteFile(f.Name)
}
// openURI calls a.appCtx.getContentResolver().openFileDescriptor on uri and
// mode and returns the detached file descriptor.
func (a *App) openURI(uri, mode string) (*os.File, error) {
var f *os.File
err := jni.Do(a.jvm, func(env *jni.Env) error {
cls := jni.GetObjectClass(env, a.appCtx)
openURI := jni.GetMethodID(env, cls, "openUri", "(Ljava/lang/String;Ljava/lang/String;)I")
juri := jni.JavaString(env, uri)
jmode := jni.JavaString(env, mode)
fd, err := jni.CallIntMethod(env, a.appCtx, openURI, jni.Value(juri), jni.Value(jmode))
if err != nil {
return err
}
f = os.NewFile(uintptr(fd), "media-store")
return nil
})
return f, err
}
func (a *App) isChromeOS() bool {
var chromeOS bool
err := jni.Do(a.jvm, func(env *jni.Env) error {
cls := jni.GetObjectClass(env, a.appCtx)
m := jni.GetMethodID(env, cls, "isChromeOS", "()Z")
b, err := jni.CallBooleanMethod(env, a.appCtx, m)
chromeOS = b
return err
})
if err != nil {
panic(err)
}
return chromeOS
}
func (s *BackendState) updateExitNodes() {
s.ExitStatus = ExitNone
var exitID tailcfg.StableNodeID
if p := s.Prefs; p != nil {
exitID = p.ExitNodeID
if exitID != "" {
s.ExitStatus = ExitOffline
}
}
hasMyExit := exitID == ""
s.Exits = nil
var peers []tailcfg.NodeView
if s.NetworkMap != nil {
peers = s.NetworkMap.Peers
}
for _, p := range peers {
canRoute := false
for i := range p.AllowedIPs().Len() {
r := p.AllowedIPs().At(i)
if r == netip.MustParsePrefix("0.0.0.0/0") || r == netip.MustParsePrefix("::/0") {
canRoute = true
break
}
}
myExit := p.StableID() == exitID
hasMyExit = hasMyExit || myExit
exit := Peer{
Label: p.DisplayName(true),
Online: canRoute,
ID: p.StableID(),
Location: p.Hostinfo().Location(),
}
if exit.Location != nil {
// We want to shorten what the users sees here,
// so override the display name with the computed
// name.
exit.Label = p.ComputedName()
}
if myExit {
s.Exit = exit
if canRoute {
s.ExitStatus = ExitOnline
}
}
if canRoute || myExit {
s.Exits = append(s.Exits, exit)
}
}
locationBasedExitPeersMap := make(map[string]Peer)
var nonLocationBasedExitPeers []Peer
var allLocationBasedExitPeers []Peer
for _, peer := range s.Exits {
if peer.Location != nil {
countryCityLocation, ok := locationBasedExitPeersMap[fmt.Sprintf("%s (%s)", peer.Location.Country, peer.Location.City)]
if !ok {
// If we have not seen the country/city combination, add it to the
// map.
locationBasedExitPeersMap[fmt.Sprintf("%s (%s)", peer.Location.Country, peer.Location.City)] = peer
continue
}
if countryCityLocation.Location.Priority < peer.Location.Priority {
// If the priority for the location based exit node is higher than
// the current option, replace it.
locationBasedExitPeersMap[fmt.Sprintf("%s (%s)", peer.Location.Country, peer.Location.City)] = peer
}
allLocationBasedExitPeers = append(allLocationBasedExitPeers, peer)
continue
}
nonLocationBasedExitPeers = append(nonLocationBasedExitPeers, peer)
}
// We want to order the exit nodes to be display to the user in
// the order of non location based exit nodes, the best exit
// node per location, and then all of the location based exit nodes.
// Non location based exit nodes.
s.Exits = nonLocationBasedExitPeers
sort.Slice(s.Exits, func(i, j int) bool {
return s.Exits[i].Label < s.Exits[j].Label
})
// Best location based exit nodes
locationBasedExitPeersMapValues := maps.Values(locationBasedExitPeersMap)
if len(locationBasedExitPeersMapValues) > 0 {
var preferredLocationBasedExitPeers []Peer
for _, peer := range locationBasedExitPeersMapValues {
peerCopy := peer
peerCopy.PreferredExitNode = true
peerCopy.Label = fmt.Sprintf("%s - %s (%s)", peerCopy.Location.Country, peerCopy.Location.City, peerCopy.Label)
preferredLocationBasedExitPeers = append(preferredLocationBasedExitPeers, peerCopy)
}
sort.Slice(preferredLocationBasedExitPeers, func(i, j int) bool {
// Sort the order by country, and cities.
res := cmp.Compare(preferredLocationBasedExitPeers[i].Location.Country, preferredLocationBasedExitPeers[j].Location.Country)
switch res {
case -1:
return true
case 1:
return false
default:
// If the two peers have the same country, sort by city.
return preferredLocationBasedExitPeers[i].Location.City < preferredLocationBasedExitPeers[j].Location.City
}
})
s.Exits = append(s.Exits, preferredLocationBasedExitPeers...)
}
if len(allLocationBasedExitPeers) > 0 {
// All location based exit nodes at the end.
sort.Slice(allLocationBasedExitPeers, func(i, j int) bool {
// Sort the order by label
return allLocationBasedExitPeers[i].Label < allLocationBasedExitPeers[j].Label
})
s.Exits = append(s.Exits, allLocationBasedExitPeers...)
}
if !hasMyExit {
// Insert node missing from netmap.
s.Exit = Peer{Label: "Unknown device", ID: exitID}
s.Exits = append([]Peer{s.Exit}, s.Exits...)
}
}
// hostname builds a hostname from android.os.Build fields, in place of a
// useless os.Hostname().
func (a *App) hostname() string {
var hostname string
err := jni.Do(a.jvm, func(env *jni.Env) error {
cls := jni.GetObjectClass(env, a.appCtx)
getHostname := jni.GetMethodID(env, cls, "getHostname", "()Ljava/lang/String;")
n, err := jni.CallObjectMethod(env, a.appCtx, getHostname)
hostname = jni.GoString(env, jni.String(n))
return err
})
if err != nil {
panic(err)
}
return hostname
}
// osVersion returns android.os.Build.VERSION.RELEASE. " [nogoogle]" is appended
// if Google Play services are not compiled in.
func (a *App) osVersion() string {
var version string
err := jni.Do(a.jvm, func(env *jni.Env) error {
cls := jni.GetObjectClass(env, a.appCtx)
m := jni.GetMethodID(env, cls, "getOSVersion", "()Ljava/lang/String;")
n, err := jni.CallObjectMethod(env, a.appCtx, m)
version = jni.GoString(env, jni.String(n))
return err
})
if err != nil {
panic(err)
}
return version
}
// modelName return the MANUFACTURER + MODEL from
// android.os.Build.
func (a *App) modelName() string {
var model string
err := jni.Do(a.jvm, func(env *jni.Env) error {
cls := jni.GetObjectClass(env, a.appCtx)
m := jni.GetMethodID(env, cls, "getModelName", "()Ljava/lang/String;")
n, err := jni.CallObjectMethod(env, a.appCtx, m)
model = jni.GoString(env, jni.String(n))
return err
})
if err != nil {
panic(err)
}
return model
}
func googleSignInEnabled() bool {
return googleClass != 0
}
// updateNotification updates the foreground persistent status notification.
func (a *App) updateNotification(service jni.Object, state ipn.State, exitStatus ExitStatus, exit Peer) error {
var msg, title string
switch state {
case ipn.Starting:
title, msg = "Connecting...", ""
case ipn.Running:
title = "Connected"
switch exitStatus {
case ExitOnline:
msg = fmt.Sprintf("Exit node: %s", exit.Label)
default:
msg = ""
}
default:
return nil
}
return jni.Do(a.jvm, func(env *jni.Env) error {
cls := jni.GetObjectClass(env, service)
update := jni.GetMethodID(env, cls, "updateStatusNotification", "(Ljava/lang/String;Ljava/lang/String;)V")
jtitle := jni.JavaString(env, title)
jmessage := jni.JavaString(env, msg)
return jni.CallVoidMethod(env, service, update, jni.Value(jtitle), jni.Value(jmessage))
})
}
// notifyExpiry notifies the user of imminent session expiry and
// returns a new timer that triggers when the user should be notified
// again.
func (a *App) notifyExpiry(service jni.Object, expiry time.Time) *time.Timer {
if expiry.IsZero() {
return nil
}
d := time.Until(expiry)
var title string
const msg = "Reauthenticate to maintain the connection to your network."
var t *time.Timer
const (
aday = 24 * time.Hour
soon = 5 * time.Minute
)
switch {
case d <= 0:
title = "Your authentication has expired!"
case d <= soon:
title = "Your authentication expires soon!"
t = time.NewTimer(d)
case d <= aday:
title = "Your authentication expires in a day."
t = time.NewTimer(d - soon)
default:
return time.NewTimer(d - aday)
}
if err := a.pushNotify(service, title, msg); err != nil {
fatalErr(err)
}
return t
}
func (a *App) notifyFile(uri, msg string) error {
return jni.Do(a.jvm, func(env *jni.Env) error {
cls := jni.GetObjectClass(env, a.appCtx)
notify := jni.GetMethodID(env, cls, "notifyFile", "(Ljava/lang/String;Ljava/lang/String;)V")
juri := jni.JavaString(env, uri)
jmsg := jni.JavaString(env, msg)
return jni.CallVoidMethod(env, a.appCtx, notify, jni.Value(juri), jni.Value(jmsg))
})
}
func (a *App) pushNotify(service jni.Object, title, msg string) error {
return jni.Do(a.jvm, func(env *jni.Env) error {
cls := jni.GetObjectClass(env, service)
notify := jni.GetMethodID(env, cls, "notify", "(Ljava/lang/String;Ljava/lang/String;)V")
jtitle := jni.JavaString(env, title)
jmessage := jni.JavaString(env, msg)
return jni.CallVoidMethod(env, service, notify, jni.Value(jtitle), jni.Value(jmessage))
})
}
func (a *App) notify(state BackendState) {
select {
case <-a.netStates:
default:
}
a.netStates <- state
ready := jni.Bool(state.State >= ipn.Stopped)
if err := a.callVoidMethod(a.appCtx, "setTileReady", "(Z)V", jni.Value(ready)); err != nil {
fatalErr(err)
}
}
func (a *App) setPrefs(prefs *ipn.Prefs) {
wantRunning := jni.Bool(prefs.WantRunning)
if err := a.callVoidMethod(a.appCtx, "setTileStatus", "(Z)V", jni.Value(wantRunning)); err != nil {
fatalErr(err)
}
select {
case <-a.prefs:
default:
}
a.prefs <- prefs
}
func (a *App) setURL(url string) {
select {
case <-a.browseURLs:
default:
}
a.browseURLs <- url
}
func (a *App) runUI() error {
w := app.NewWindow()
ui, err := newUI(a.store)
if err != nil {
return err
}
var ops op.Ops
state := new(clientState)
var (
// activity is the most recent Android Activity reference as reported
// by Gio ViewEvents.
activity jni.Object
// files is list of files from the most recent file sharing intent.
files []File
)
deleteActivityRef := func() {
if activity == 0 {
return
}
jni.Do(a.jvm, func(env *jni.Env) error {
jni.DeleteGlobalRef(env, activity)
return nil
})
activity = 0
}
defer deleteActivityRef()
for {
select {
case <-onVPNClosed:
requestBackend(ConnectEvent{Enable: false})
case tok := <-onGoogleToken:
ui.signinType = noSignin
if tok != "" {
requestBackend(OAuth2Event{
Token: &tailcfg.Oauth2Token{
AccessToken: tok,
TokenType: ipn.GoogleIDTokenType,
},
})
} else {
// Warn about possible debug certificate.
if !a.isReleaseSigned() {
ui.ShowMessage("Google Sign-In failed because the app is not signed for Play Store")
w.Invalidate()
}
}
case p := <-a.prefs:
ui.enabled.Value = p.WantRunning
ui.runningExit = p.AdvertisesExitNode()
ui.exitLAN.Value = p.ExitNodeAllowLANAccess
w.Invalidate()
case url := <-a.browseURLs:
ui.signinType = noSignin
if a.isTV() {
ui.ShowQRCode(url)
} else {
state.browseURL = url
}
w.Invalidate()
a.updateState(activity, state)
case newState := <-a.netStates:
oldState := state.backend.State
state.backend = newState
a.updateState(activity, state)
w.Invalidate()
if activity != 0 {
newState := state.backend.State
// Start VPN if we just logged in.
if oldState <= ipn.Stopped && newState > ipn.Stopped {
if err := a.prepareVPN(activity); err != nil {
fatalErr(err)
}
}
}
case <-onVPNPrepared:
if state.backend.State > ipn.Stopped {
if err := a.callVoidMethod(a.appCtx, "startVPN", "()V"); err != nil {
return err
}
if activity != 0 {
if err := a.callVoidMethod(a.appCtx, "requestWriteStoragePermission", "(Landroid/app/Activity;)V", jni.Value(activity)); err != nil {
return err
}
}
}
case <-onVPNRevoked:
ui.ShowMessage("VPN access denied or another VPN service is always-on")
w.Invalidate()
case files = <-onFileShare:
ui.ShowShareDialog()
w.Invalidate()
case t := <-a.targetsLoaded:
ui.FillShareDialog(t.Targets, t.Err)
w.Invalidate()
case <-a.invalidates:
w.Invalidate()
case e := <-w.Events():
switch e := e.(type) {
case app.ViewEvent:
deleteActivityRef()
view := jni.Object(e.View)
if view == 0 {
break
}
activity = a.contextForView(view)
w.Invalidate()
a.attachPeer(activity)
if state.backend.State > ipn.Stopped {
if err := a.prepareVPN(activity); err != nil {
return err
}
}
case system.DestroyEvent:
return e.Err
case key.Event:
if e.Name == key.NameBack {
if ui.onBack() {
w.Invalidate()
}
}
case system.FrameEvent:
ins := e.Insets
e.Insets = system.Insets{}
gtx := layout.NewContext(&ops, e)
events := ui.layout(gtx, ins, state)
e.Frame(gtx.Ops)
a.processUIEvents(w, events, activity, state, files)
}
}
}
}
func (a *App) isTV() bool {
var istv bool
err := jni.Do(a.jvm, func(env *jni.Env) error {
cls := jni.GetObjectClass(env, a.appCtx)
m := jni.GetMethodID(env, cls, "isTV", "()Z")
b, err := jni.CallBooleanMethod(env, a.appCtx, m)
istv = b
return err
})
if err != nil {
fatalErr(err)
}
return istv
}
// isReleaseSigned reports whether the app is signed with a release
// signature.
func (a *App) isReleaseSigned() bool {
var cert []byte
err := jni.Do(a.jvm, func(env *jni.Env) error {
cls := jni.GetObjectClass(env, a.appCtx)
m := jni.GetMethodID(env, cls, "getPackageCertificate", "()[B")
str, err := jni.CallObjectMethod(env, a.appCtx, m)
if err != nil {
return err
}
cert = jni.GetByteArrayElements(env, jni.ByteArray(str))
return nil
})
if err != nil {
fatalErr(err)
}
h := sha1.New()
h.Write(cert)
fingerprint := h.Sum(nil)
hex := fmt.Sprintf("%x", fingerprint)
// Strip colons and convert to lower case to ease comparing.
wantFingerprint := strings.ReplaceAll(strings.ToLower(releaseCertFingerprint), ":", "")
return hex == wantFingerprint
}
// attachPeer registers an Android Fragment instance for
// handling onActivityResult callbacks.
func (a *App) attachPeer(act jni.Object) {
err := a.callVoidMethod(a.appCtx, "attachPeer", "(Landroid/app/Activity;)V", jni.Value(act))
if err != nil {
fatalErr(err)
}
}
func (a *App) updateState(act jni.Object, state *clientState) {
if act != 0 && state.browseURL != "" {
a.browseToURL(act, state.browseURL)
state.browseURL = ""
}
netmap := state.backend.NetworkMap
var (
peers []tailcfg.NodeView
myID tailcfg.UserID
)
if netmap != nil {
peers = netmap.Peers
myID = netmap.User()
}
// Split into sections.
users := make(map[tailcfg.UserID]struct{})
var uiPeers []UIPeer
for _, p := range peers {
if p.Hostinfo().Valid() && p.Hostinfo().ShareeNode() {
// Don't show nodes that only exist in the netmap because they're
// owned by somebody the user shared a node with. We can't see their
// details (including their name) anyway, so there's nothing
// interesting to render.
continue
}
if q := state.query; q != "" {
// Filter peers according to search query.
host := strings.ToLower(p.Hostinfo().Hostname())
name := strings.ToLower(p.Name())
var addr string
if p.Addresses().Len() > 0 {
addr = p.Addresses().At(0).Addr().String()
}
if !strings.Contains(host, q) && !strings.Contains(name, q) && !strings.Contains(addr, q) {
continue
}
}
uid := p.SharerOrUser()
users[uid] = struct{}{}
uiPeers = append(uiPeers, UIPeer{
Owner: uid,
Peer: p.AsStruct(),
})
}
// Add section (user) headers.
for u := range users {
name := netmap.UserProfiles[u].DisplayName
name = strings.ToUpper(name)
uiPeers = append(uiPeers, UIPeer{Owner: u, Name: name})
}
sort.Slice(uiPeers, func(i, j int) bool {
lhs, rhs := uiPeers[i], uiPeers[j]
if lu, ru := lhs.Owner, rhs.Owner; ru != lu {
// Sort own peers first.
if lu == myID {
return true
}
if ru == myID {
return false
}
return lu < ru
}
lp, rp := lhs.Peer, rhs.Peer
// Sort headers first.
if lp == nil {
return true
}
if rp == nil {
return false
}
lName := lp.DisplayName(lp.User == myID)
rName := rp.DisplayName(rp.User == myID)
return lName < rName || lName == rName && lp.ID < rp.ID
})
state.Peers = uiPeers
}
func (a *App) prepareVPN(act jni.Object) error {
return a.callVoidMethod(a.appCtx, "prepareVPN", "(Landroid/app/Activity;I)V",
jni.Value(act), jni.Value(requestPrepareVPN))
}
func requestBackend(e UIEvent) {
go func() {
backendEvents <- e
}()
}
func (a *App) processUIEvents(w *app.Window, events []UIEvent, act jni.Object, state *clientState, files []File) {
for _, e := range events {
switch e := e.(type) {
case ReauthEvent:
method, _ := a.store.ReadString(loginMethodPrefKey, loginMethodWeb)
switch method {
case loginMethodGoogle:
a.googleSignIn(act)
default:
requestBackend(WebAuthEvent{})
}
case BugEvent:
// clear the channel in case there's an old bug report hanging out there
select {
case oldReport := <-a.bugReport:
log.Printf("clearing old bug report in channel: %s", oldReport)
default:
break
}
requestBackend(e)
select {
case bug := <-a.bugReport:
w.WriteClipboard(bug)
case <-time.After(2 * time.Second):
// if we don't get a bug through the channel, fall back and create bug report here
backendLogID := a.logIDPublicAtomic.Load()
logMarker := fmt.Sprintf("BUG-%v-%v-%v", backendLogID, time.Now().UTC().Format("20060102150405Z"), randHex(8))
log.Printf("bug report fallback because timed out. fallback report: %s", logMarker)
w.WriteClipboard(logMarker)
}
case BeExitNodeEvent:
requestBackend(e)
case ExitAllowLANEvent:
requestBackend(e)
case WebAuthEvent:
a.decorateEventWithStoredSettings(&e, state)
a.store.WriteString(loginMethodPrefKey, loginMethodWeb)
requestBackend(e)
case SetLoginServerEvent:
a.store.WriteString(customLoginServerPrefKey, e.URL)
requestBackend(e)
case LogoutEvent:
a.signOut()
requestBackend(e)
case ConnectEvent:
a.decorateEventWithStoredSettings(&e, state)
requestBackend(e)
case RouteAllEvent:
requestBackend(e)
case CopyEvent:
w.WriteClipboard(e.Text)
case GoogleAuthEvent:
a.store.WriteString(loginMethodPrefKey, loginMethodGoogle)
a.googleSignIn(act)
case SearchEvent:
state.query = strings.ToLower(e.Query)
a.updateState(act, state)
case FileSendEvent:
a.sendFiles(e, files)
case OSSLicensesEvent:
a.setURL("https://tailscale.com/licenses/android")
}
}
}
func (a *App) decorateEventWithStoredSettings(e RestoreEvent, state *clientState) {
srv, _ := a.store.ReadString(customLoginServerPrefKey, "")
if srv != "" && srv != state.backend.Prefs.ControlURL {
e.SetURL(srv)
}
exitstr, _ := a.store.ReadString(exitNodePrefKey, "")
exitNodeID := tailcfg.StableNodeID(exitstr)
if exitNodeID != "" && exitNodeID != state.backend.Prefs.ExitNodeID {
e.SetExitNodeID(exitNodeID)
}
allowlan, _ := a.store.ReadBool(exitAllowLANPrefKey, false)
if allowlan {
e.SetExitAllowLAN(allowlan)
}
}
func (a *App) sendFiles(e FileSendEvent, files []File) {
go func() {
var totalSize int64
for _, f := range files {
totalSize += f.Size
}
if totalSize == 0 {
totalSize = 1
}
var totalSent int64
progress := func(n int64) {
totalSent += n
e.Updates(FileSendInfo{
State: FileSendTransferring,
Progress: float64(totalSent) / float64(totalSize),
})
a.invalidate()
}
defer a.invalidate()
for _, f := range files {
if err := a.sendFile(e.Context, e.Target, f, progress); err != nil {
if errors.Is(err, context.Canceled) {
return
}
e.Updates(FileSendInfo{
State: FileSendFailed,
})
return
}
}
e.Updates(FileSendInfo{
State: FileSendComplete,
})
}()
}
func (a *App) invalidate() {
select {
case a.invalidates <- struct{}{}:
default:
}
}
func (a *App) sendFile(ctx context.Context, target *apitype.FileTarget, f File, progress func(n int64)) error {
var body io.Reader
switch f.Type {
case FileTypeText:
body = strings.NewReader(f.Text)
case FileTypeURI:
f, err := a.openURI(f.URI, "r")
if err != nil {
return err
}
defer f.Close()
body = f
default:
panic("unknown file type")
}
body = &progressReader{r: body, size: f.Size, progress: progress}
dstURL := target.PeerAPIURL + "/v0/put/" + url.PathEscape(f.Name)
req, err := http.NewRequestWithContext(ctx, "PUT", dstURL, body)
if err != nil {
return err
}
req.ContentLength = f.Size
res, err := http.DefaultClient.Do(req)
if err != nil {
return err
}
defer res.Body.Close()
if res.StatusCode != 200 {
return fmt.Errorf("PUT failed: %s", res.Status)
}
return nil
}
// progressReader wraps an io.Reader to call a progress function
// on every non-zero Read.
type progressReader struct {
r io.Reader
bytes int64
size int64
eof bool
progress func(n int64)
}
func (r *progressReader) Read(p []byte) (int, error) {
n, err := r.r.Read(p)
// The request body may be read after http.Client.Do returns, see
// https://github.com/golang/go/issues/30597. Don't update progress if the
// file has been read.
r.eof = r.eof || errors.Is(err, io.EOF)
if !r.eof && r.bytes < r.size {
r.progress(int64(n))
r.bytes += int64(n)
}
return n, err
}
func (a *App) signOut() {
if googleClass == 0 {
return
}
err := jni.Do(a.jvm, func(env *jni.Env) error {
m := jni.GetStaticMethodID(env, googleClass,
"googleSignOut", "(Landroid/content/Context;)V")
return jni.CallStaticVoidMethod(env, googleClass, m, jni.Value(a.appCtx))
})
if err != nil {
fatalErr(err)
}
}
func (a *App) googleSignIn(act jni.Object) {
if act == 0 || googleClass == 0 {
return
}
err := jni.Do(a.jvm, func(env *jni.Env) error {
sid := jni.JavaString(env, serverOAuthID)
m := jni.GetStaticMethodID(env, googleClass,
"googleSignIn", "(Landroid/app/Activity;Ljava/lang/String;I)V")
return jni.CallStaticVoidMethod(env, googleClass, m,
jni.Value(act), jni.Value(sid), jni.Value(requestSignin))
})
if err != nil {
fatalErr(err)
}
}
func (a *App) browseToURL(act jni.Object, url string) {
if act == 0 {
return
}
err := jni.Do(a.jvm, func(env *jni.Env) error {
jurl := jni.JavaString(env, url)
return a.callVoidMethod(a.appCtx, "showURL", "(Landroid/app/Activity;Ljava/lang/String;)V", jni.Value(act), jni.Value(jurl))
})
if err != nil {
fatalErr(err)
}
}
func (a *App) callVoidMethod(obj jni.Object, name, sig string, args ...jni.Value) error {
if obj == 0 {
panic("invalid object")
}
return jni.Do(a.jvm, func(env *jni.Env) error {
cls := jni.GetObjectClass(env, obj)
m := jni.GetMethodID(env, cls, name, sig)
return jni.CallVoidMethod(env, obj, m, args...)
})
}
// activityForView calls View.getContext and returns a global
// reference to the result.
func (a *App) contextForView(view jni.Object) jni.Object {
if view == 0 {
panic("invalid object")
}
var ctx jni.Object
err := jni.Do(a.jvm, func(env *jni.Env) error {
cls := jni.GetObjectClass(env, view)
m := jni.GetMethodID(env, cls, "getContext", "()Landroid/content/Context;")
var err error
ctx, err = jni.CallObjectMethod(env, view, m)
ctx = jni.NewGlobalRef(env, ctx)
return err
})
if err != nil {
panic(err)
}
return ctx
}
// Report interfaces in the device in net.Interface format.
func (a *App) getInterfaces() ([]interfaces.Interface, error) {
var ifaceString string
err := jni.Do(a.jvm, func(env *jni.Env) error {
cls := jni.GetObjectClass(env, a.appCtx)
m := jni.GetMethodID(env, cls, "getInterfacesAsString", "()Ljava/lang/String;")
n, err := jni.CallObjectMethod(env, a.appCtx, m)
ifaceString = jni.GoString(env, jni.String(n))
return err
})
var ifaces []interfaces.Interface
if err != nil {
return ifaces, err
}
for _, iface := range strings.Split(ifaceString, "\n") {
// Example of the strings we're processing:
// wlan0 30 1500 true true false false true | fe80::2f60:2c82:4163:8389%wlan0/64 10.1.10.131/24
// r_rmnet_data0 21 1500 true false false false false | fe80::9318:6093:d1ad:ba7f%r_rmnet_data0/64
// mnet_data2 12 1500 true false false false false | fe80::3c8c:44dc:46a9:9907%rmnet_data2/64
if strings.TrimSpace(iface) == "" {
continue
}
fields := strings.Split(iface, "|")
if len(fields) != 2 {
log.Printf("getInterfaces: unable to split %q", iface)
continue
}
var name string
var index, mtu int
var up, broadcast, loopback, pointToPoint, multicast bool
_, err := fmt.Sscanf(fields[0], "%s %d %d %t %t %t %t %t",
&name, &index, &mtu, &up, &broadcast, &loopback, &pointToPoint, &multicast)
if err != nil {
log.Printf("getInterfaces: unable to parse %q: %v", iface, err)
continue
}
newIf := interfaces.Interface{
Interface: &net.Interface{
Name: name,
Index: index,
MTU: mtu,
},
AltAddrs: []net.Addr{}, // non-nil to avoid Go using netlink
}
if up {
newIf.Flags |= net.FlagUp
}
if broadcast {
newIf.Flags |= net.FlagBroadcast
}
if loopback {
newIf.Flags |= net.FlagLoopback
}
if pointToPoint {
newIf.Flags |= net.FlagPointToPoint
}
if multicast {
newIf.Flags |= net.FlagMulticast
}
addrs := strings.Trim(fields[1], " \n")
for _, addr := range strings.Split(addrs, " ") {
ip, err := netaddr.ParseIPPrefix(addr)
if err == nil {
newIf.AltAddrs = append(newIf.AltAddrs, ip.IPNet())
}
}
ifaces = append(ifaces, newIf)
}
return ifaces, nil
}
func fatalErr(err error) {
// TODO: expose in UI.
log.Printf("fatal error: %v", err)
}
func randHex(n int) string {
b := make([]byte, n)
rand.Read(b)
return hex.EncodeToString(b)
}
const multipleUsersText = "Tailscale can't start due to an Android bug when multiple users are present on this device. " +
"Please see https://tailscale.com/s/multi-user-bug for more information."