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tailscale/ipn/ipnlocal/local.go
Tom DNetto a515fc517b ipn/ipnlocal: make tkaSyncIfNeeded exclusive with a mutex 
Running corp/ipn#TestNetworkLockE2E has a 1/300 chance of failing, and
deskchecking suggests thats whats happening are two netmaps are racing each
other to be processed through tkaSyncIfNeededLocked. This happens in the
first place because we release b.mu during network RPCs.

To fix this, we make the tka sync logic an exclusive section, so two
netmaps will need to wait for tka sync to complete serially (which is what
we would want anyway, as the second run through probably wont need to
sync).

Signed-off-by: Tom DNetto <tom@tailscale.com>
2022-10-14 12:42:43 -07:00

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// 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 ipnlocal
import (
"context"
"errors"
"fmt"
"io"
"net"
"net/http"
"net/netip"
"os"
"os/user"
"path/filepath"
"runtime"
"sort"
"strconv"
"strings"
"sync"
"sync/atomic"
"time"
"go4.org/netipx"
"golang.org/x/exp/slices"
"tailscale.com/client/tailscale/apitype"
"tailscale.com/control/controlclient"
"tailscale.com/doctor"
"tailscale.com/doctor/routetable"
"tailscale.com/envknob"
"tailscale.com/health"
"tailscale.com/hostinfo"
"tailscale.com/ipn"
"tailscale.com/ipn/ipnstate"
"tailscale.com/ipn/policy"
"tailscale.com/net/dns"
"tailscale.com/net/dnsfallback"
"tailscale.com/net/interfaces"
"tailscale.com/net/netutil"
"tailscale.com/net/tsaddr"
"tailscale.com/net/tsdial"
"tailscale.com/paths"
"tailscale.com/portlist"
"tailscale.com/syncs"
"tailscale.com/tailcfg"
"tailscale.com/tka"
"tailscale.com/types/dnstype"
"tailscale.com/types/empty"
"tailscale.com/types/key"
"tailscale.com/types/logger"
"tailscale.com/types/netmap"
"tailscale.com/types/persist"
"tailscale.com/types/preftype"
"tailscale.com/types/views"
"tailscale.com/util/deephash"
"tailscale.com/util/dnsname"
"tailscale.com/util/mak"
"tailscale.com/util/multierr"
"tailscale.com/util/osshare"
"tailscale.com/util/systemd"
"tailscale.com/version"
"tailscale.com/version/distro"
"tailscale.com/wgengine"
"tailscale.com/wgengine/filter"
"tailscale.com/wgengine/magicsock"
"tailscale.com/wgengine/router"
"tailscale.com/wgengine/wgcfg"
"tailscale.com/wgengine/wgcfg/nmcfg"
)
var controlDebugFlags = getControlDebugFlags()
func getControlDebugFlags() []string {
if e := envknob.String("TS_DEBUG_CONTROL_FLAGS"); e != "" {
return strings.Split(e, ",")
}
return nil
}
// SSHServer is the interface of the conditionally linked ssh/tailssh.server.
type SSHServer interface {
HandleSSHConn(net.Conn) error
// OnPolicyChange is called when the SSH access policy changes,
// so that existing sessions can be re-evaluated for validity
// and closed if they'd no longer be accepted.
OnPolicyChange()
// Shutdown is called when tailscaled is shutting down.
Shutdown()
}
type newSSHServerFunc func(logger.Logf, *LocalBackend) (SSHServer, error)
var newSSHServer newSSHServerFunc // or nil
// RegisterNewSSHServer lets the conditionally linked ssh/tailssh package register itself.
func RegisterNewSSHServer(fn newSSHServerFunc) {
newSSHServer = fn
}
// LocalBackend is the glue between the major pieces of the Tailscale
// network software: the cloud control plane (via controlclient), the
// network data plane (via wgengine), and the user-facing UIs and CLIs
// (collectively called "frontends", via LocalBackend's implementation
// of the Backend interface).
//
// LocalBackend implements the overall state machine for the Tailscale
// application. Frontends, controlclient and wgengine can feed events
// into LocalBackend to advance the state machine, and advancing the
// state machine generates events back out to zero or more components.
type LocalBackend struct {
// Elements that are thread-safe or constant after construction.
ctx context.Context // canceled by Close
ctxCancel context.CancelFunc // cancels ctx
logf logger.Logf // general logging
keyLogf logger.Logf // for printing list of peers on change
statsLogf logger.Logf // for printing peers stats on change
e wgengine.Engine
store ipn.StateStore
dialer *tsdial.Dialer // non-nil
backendLogID string
unregisterLinkMon func()
unregisterHealthWatch func()
portpoll *portlist.Poller // may be nil
portpollOnce sync.Once // guards starting readPoller
gotPortPollRes chan struct{} // closed upon first readPoller result
serverURL string // tailcontrol URL
newDecompressor func() (controlclient.Decompressor, error)
varRoot string // or empty if SetVarRoot never called
sshAtomicBool atomic.Bool
shutdownCalled bool // if Shutdown has been called
filterAtomic atomic.Pointer[filter.Filter]
containsViaIPFuncAtomic syncs.AtomicValue[func(netip.Addr) bool]
// The mutex protects the following elements.
mu sync.Mutex
filterHash deephash.Sum
httpTestClient *http.Client // for controlclient. nil by default, used by tests.
ccGen clientGen // function for producing controlclient; lazily populated
sshServer SSHServer // or nil, initialized lazily.
notify func(ipn.Notify)
cc controlclient.Client
ccAuto *controlclient.Auto // if cc is of type *controlclient.Auto
stateKey ipn.StateKey // computed in part from user-provided value
userID string // current controlling user ID (for Windows, primarily)
prefs *ipn.Prefs
inServerMode bool
machinePrivKey key.MachinePrivate
nlPrivKey key.NLPrivate
tka *tkaState
state ipn.State
capFileSharing bool // whether netMap contains the file sharing capability
// hostinfo is mutated in-place while mu is held.
hostinfo *tailcfg.Hostinfo
// netMap is not mutated in-place once set.
netMap *netmap.NetworkMap
nodeByAddr map[netip.Addr]*tailcfg.Node
activeLogin string // last logged LoginName from netMap
engineStatus ipn.EngineStatus
endpoints []tailcfg.Endpoint
blocked bool
keyExpired bool
authURL string // cleared on Notify
authURLSticky string // not cleared on Notify
interact bool
egg bool
prevIfState *interfaces.State
peerAPIServer *peerAPIServer // or nil
peerAPIListeners []*peerAPIListener
loginFlags controlclient.LoginFlags
incomingFiles map[*incomingFile]bool
lastStatusTime time.Time // status.AsOf value of the last processed status update
// directFileRoot, if non-empty, means to write received files
// directly to this directory, without staging them in an
// intermediate buffered directory for "pick-up" later. If
// empty, the files are received in a daemon-owned location
// and the localapi is used to enumerate, download, and delete
// them. This is used on macOS where the GUI lifetime is the
// same as the Network Extension lifetime and we can thus avoid
// double-copying files by writing them to the right location
// immediately.
// It's also used on several NAS platforms (Synology, TrueNAS, etc)
// but in that case DoFinalRename is also set true, which moves the
// *.partial file to its final name on completion.
directFileRoot string
directFileDoFinalRename bool // false on macOS, true on several NAS platforms
componentLogUntil map[string]componentLogState
// statusLock must be held before calling statusChanged.Wait() or
// statusChanged.Broadcast().
statusLock sync.Mutex
statusChanged *sync.Cond
// dialPlan is any dial plan that we've received from the control
// server during a previous connection; it is cleared on logout.
dialPlan atomic.Pointer[tailcfg.ControlDialPlan]
// tkaSyncLock is used to make tkaSyncIfNeeded an exclusive
// section. This is needed to stop two map-responses in quick succession
// from racing each other through TKA sync logic / RPCs.
//
// tkaSyncLock MUST be taken before mu (or inversely, mu must not be held
// at the moment that tkaSyncLock is taken).
tkaSyncLock sync.Mutex
}
// clientGen is a func that creates a control plane client.
// It's the type used by LocalBackend.SetControlClientGetterForTesting.
type clientGen func(controlclient.Options) (controlclient.Client, error)
// NewLocalBackend returns a new LocalBackend that is ready to run,
// but is not actually running.
//
// If dialer is nil, a new one is made.
func NewLocalBackend(logf logger.Logf, logid string, store ipn.StateStore, dialer *tsdial.Dialer, e wgengine.Engine, loginFlags controlclient.LoginFlags) (*LocalBackend, error) {
if e == nil {
panic("ipn.NewLocalBackend: engine must not be nil")
}
hi := hostinfo.New()
logf.JSON(1, "Hostinfo", hi)
envknob.LogCurrent(logf)
if dialer == nil {
dialer = &tsdial.Dialer{Logf: logf}
}
osshare.SetFileSharingEnabled(false, logf)
ctx, cancel := context.WithCancel(context.Background())
portpoll, err := portlist.NewPoller()
if err != nil {
logf("skipping portlist: %s", err)
}
b := &LocalBackend{
ctx: ctx,
ctxCancel: cancel,
logf: logf,
keyLogf: logger.LogOnChange(logf, 5*time.Minute, time.Now),
statsLogf: logger.LogOnChange(logf, 5*time.Minute, time.Now),
e: e,
store: store,
dialer: dialer,
backendLogID: logid,
state: ipn.NoState,
portpoll: portpoll,
gotPortPollRes: make(chan struct{}),
loginFlags: loginFlags,
}
// Default filter blocks everything and logs nothing, until Start() is called.
b.setFilter(filter.NewAllowNone(logf, &netipx.IPSet{}))
b.statusChanged = sync.NewCond(&b.statusLock)
b.e.SetStatusCallback(b.setWgengineStatus)
linkMon := e.GetLinkMonitor()
b.prevIfState = linkMon.InterfaceState()
// Call our linkChange code once with the current state, and
// then also whenever it changes:
b.linkChange(false, linkMon.InterfaceState())
b.unregisterLinkMon = linkMon.RegisterChangeCallback(b.linkChange)
b.unregisterHealthWatch = health.RegisterWatcher(b.onHealthChange)
wiredPeerAPIPort := false
if ig, ok := e.(wgengine.InternalsGetter); ok {
if tunWrap, _, _, ok := ig.GetInternals(); ok {
tunWrap.PeerAPIPort = b.GetPeerAPIPort
wiredPeerAPIPort = true
}
}
if !wiredPeerAPIPort {
b.logf("[unexpected] failed to wire up peer API port for engine %T", e)
}
for _, component := range debuggableComponents {
key := componentStateKey(component)
if ut, err := ipn.ReadStoreInt(store, key); err == nil {
if until := time.Unix(ut, 0); until.After(time.Now()) {
// conditional to avoid log spam at start when off
b.SetComponentDebugLogging(component, until)
}
}
}
return b, nil
}
type componentLogState struct {
until time.Time
timer *time.Timer // if non-nil, the AfterFunc to disable it
}
var debuggableComponents = []string{
"magicsock",
}
func componentStateKey(component string) ipn.StateKey {
return ipn.StateKey("_debug_" + component + "_until")
}
// SetComponentDebugLogging sets component's debug logging enabled until the until time.
// If until is in the past, the component's debug logging is disabled.
//
// The following components are recognized:
//
// - magicsock
func (b *LocalBackend) SetComponentDebugLogging(component string, until time.Time) error {
b.mu.Lock()
defer b.mu.Unlock()
var setEnabled func(bool)
switch component {
case "magicsock":
mc, err := b.magicConn()
if err != nil {
return err
}
setEnabled = mc.SetDebugLoggingEnabled
}
if setEnabled == nil || !slices.Contains(debuggableComponents, component) {
return fmt.Errorf("unknown component %q", component)
}
timeUnixOrZero := func(t time.Time) int64 {
if t.IsZero() {
return 0
}
return t.Unix()
}
ipn.PutStoreInt(b.store, componentStateKey(component), timeUnixOrZero(until))
now := time.Now()
on := now.Before(until)
setEnabled(on)
var onFor time.Duration
if on {
onFor = until.Sub(now)
b.logf("debugging logging for component %q enabled for %v (until %v)", component, onFor.Round(time.Second), until.UTC().Format(time.RFC3339))
} else {
b.logf("debugging logging for component %q disabled", component)
}
if oldSt, ok := b.componentLogUntil[component]; ok && oldSt.timer != nil {
oldSt.timer.Stop()
}
newSt := componentLogState{until: until}
if on {
newSt.timer = time.AfterFunc(onFor, func() {
// Turn off logging after the timer fires, as long as the state is
// unchanged when the timer actually fires.
b.mu.Lock()
defer b.mu.Unlock()
if ls := b.componentLogUntil[component]; ls.until == until {
setEnabled(false)
b.logf("debugging logging for component %q disabled (by timer)", component)
}
})
}
mak.Set(&b.componentLogUntil, component, newSt)
return nil
}
// Dialer returns the backend's dialer.
func (b *LocalBackend) Dialer() *tsdial.Dialer {
return b.dialer
}
// SetDirectFileRoot sets the directory to download files to directly,
// without buffering them through an intermediate daemon-owned
// tailcfg.UserID-specific directory.
//
// This must be called before the LocalBackend starts being used.
func (b *LocalBackend) SetDirectFileRoot(dir string) {
b.mu.Lock()
defer b.mu.Unlock()
b.directFileRoot = dir
}
// SetDirectFileDoFinalRename sets whether the peerapi file server should rename
// a received "name.partial" file to "name" when the download is complete.
//
// This only applies when SetDirectFileRoot is non-empty.
// The default is false.
func (b *LocalBackend) SetDirectFileDoFinalRename(v bool) {
b.mu.Lock()
defer b.mu.Unlock()
b.directFileDoFinalRename = v
}
// b.mu must be held.
func (b *LocalBackend) maybePauseControlClientLocked() {
if b.cc == nil {
return
}
networkUp := b.prevIfState.AnyInterfaceUp()
b.cc.SetPaused((b.state == ipn.Stopped && b.netMap != nil) || !networkUp)
}
// linkChange is our link monitor callback, called whenever the network changes.
// major is whether ifst is different than earlier.
func (b *LocalBackend) linkChange(major bool, ifst *interfaces.State) {
b.mu.Lock()
defer b.mu.Unlock()
hadPAC := b.prevIfState.HasPAC()
b.prevIfState = ifst
b.maybePauseControlClientLocked()
// If the PAC-ness of the network changed, reconfig wireguard+route to
// add/remove subnets.
if hadPAC != ifst.HasPAC() {
b.logf("linkChange: in state %v; PAC changed from %v->%v", b.state, hadPAC, ifst.HasPAC())
switch b.state {
case ipn.NoState, ipn.Stopped:
// Do nothing.
default:
go b.authReconfig()
}
}
// If the local network configuration has changed, our filter may
// need updating to tweak default routes.
b.updateFilterLocked(b.netMap, b.prefs)
if peerAPIListenAsync && b.netMap != nil && b.state == ipn.Running {
want := len(b.netMap.Addresses)
if len(b.peerAPIListeners) < want {
b.logf("linkChange: peerAPIListeners too low; trying again")
go b.initPeerAPIListener()
}
}
}
func (b *LocalBackend) onHealthChange(sys health.Subsystem, err error) {
if err == nil {
b.logf("health(%q): ok", sys)
} else {
b.logf("health(%q): error: %v", sys, err)
}
}
// Shutdown halts the backend and all its sub-components. The backend
// can no longer be used after Shutdown returns.
func (b *LocalBackend) Shutdown() {
b.mu.Lock()
if b.shutdownCalled {
b.mu.Unlock()
return
}
b.shutdownCalled = true
if b.loginFlags&controlclient.LoginEphemeral != 0 {
b.mu.Unlock()
ctx, cancel := context.WithTimeout(b.ctx, 5*time.Second)
defer cancel()
b.LogoutSync(ctx) // best effort
b.mu.Lock()
}
cc := b.cc
if b.sshServer != nil {
b.sshServer.Shutdown()
b.sshServer = nil
}
b.closePeerAPIListenersLocked()
b.mu.Unlock()
b.unregisterLinkMon()
b.unregisterHealthWatch()
if cc != nil {
cc.Shutdown()
}
b.ctxCancel()
b.e.Close()
b.e.Wait()
}
// Prefs returns a copy of b's current prefs, with any private keys removed.
func (b *LocalBackend) Prefs() *ipn.Prefs {
b.mu.Lock()
defer b.mu.Unlock()
p := b.prefs.Clone()
if p != nil && p.Persist != nil {
p.Persist.LegacyFrontendPrivateMachineKey = key.MachinePrivate{}
p.Persist.PrivateNodeKey = key.NodePrivate{}
p.Persist.OldPrivateNodeKey = key.NodePrivate{}
}
return p
}
// Status returns the latest status of the backend and its
// sub-components.
func (b *LocalBackend) Status() *ipnstate.Status {
sb := new(ipnstate.StatusBuilder)
b.UpdateStatus(sb)
return sb.Status()
}
// StatusWithoutPeers is like Status but omits any details
// of peers.
func (b *LocalBackend) StatusWithoutPeers() *ipnstate.Status {
sb := new(ipnstate.StatusBuilder)
b.updateStatus(sb, nil)
return sb.Status()
}
// UpdateStatus implements ipnstate.StatusUpdater.
func (b *LocalBackend) UpdateStatus(sb *ipnstate.StatusBuilder) {
b.e.UpdateStatus(sb)
b.updateStatus(sb, b.populatePeerStatusLocked)
}
// updateStatus populates sb with status.
//
// extraLocked, if non-nil, is called while b.mu is still held.
func (b *LocalBackend) updateStatus(sb *ipnstate.StatusBuilder, extraLocked func(*ipnstate.StatusBuilder)) {
b.mu.Lock()
defer b.mu.Unlock()
sb.MutateStatus(func(s *ipnstate.Status) {
s.Version = version.Long
s.BackendState = b.state.String()
s.AuthURL = b.authURLSticky
if err := health.OverallError(); err != nil {
switch e := err.(type) {
case multierr.Error:
for _, err := range e.Errors() {
s.Health = append(s.Health, err.Error())
}
default:
s.Health = append(s.Health, err.Error())
}
}
if m := b.sshOnButUnusableHealthCheckMessageLocked(); m != "" {
s.Health = append(s.Health, m)
}
if b.netMap != nil {
s.CertDomains = append([]string(nil), b.netMap.DNS.CertDomains...)
s.MagicDNSSuffix = b.netMap.MagicDNSSuffix()
if s.CurrentTailnet == nil {
s.CurrentTailnet = &ipnstate.TailnetStatus{}
}
s.CurrentTailnet.MagicDNSSuffix = b.netMap.MagicDNSSuffix()
s.CurrentTailnet.MagicDNSEnabled = b.netMap.DNS.Proxied
s.CurrentTailnet.Name = b.netMap.Domain
if b.prefs != nil && !b.prefs.ExitNodeID.IsZero() {
if exitPeer, ok := b.netMap.PeerWithStableID(b.prefs.ExitNodeID); ok {
var online = false
if exitPeer.Online != nil {
online = *exitPeer.Online
}
s.ExitNodeStatus = &ipnstate.ExitNodeStatus{
ID: b.prefs.ExitNodeID,
Online: online,
TailscaleIPs: exitPeer.Addresses,
}
}
}
}
})
sb.MutateSelfStatus(func(ss *ipnstate.PeerStatus) {
ss.Online = health.GetInPollNetMap()
if b.netMap != nil {
ss.HostName = b.netMap.Hostinfo.Hostname
ss.DNSName = b.netMap.Name
ss.UserID = b.netMap.User
if sn := b.netMap.SelfNode; sn != nil {
ss.ID = sn.StableID
if c := sn.Capabilities; len(c) > 0 {
ss.Capabilities = append([]string(nil), c...)
}
}
} else {
ss.HostName, _ = os.Hostname()
}
for _, pln := range b.peerAPIListeners {
ss.PeerAPIURL = append(ss.PeerAPIURL, pln.urlStr)
}
})
// TODO: hostinfo, and its networkinfo
// TODO: EngineStatus copy (and deprecate it?)
if extraLocked != nil {
extraLocked(sb)
}
}
func (b *LocalBackend) populatePeerStatusLocked(sb *ipnstate.StatusBuilder) {
if b.netMap == nil {
return
}
for id, up := range b.netMap.UserProfiles {
sb.AddUser(id, up)
}
for _, p := range b.netMap.Peers {
var lastSeen time.Time
if p.LastSeen != nil {
lastSeen = *p.LastSeen
}
var tailscaleIPs = make([]netip.Addr, 0, len(p.Addresses))
for _, addr := range p.Addresses {
if addr.IsSingleIP() && tsaddr.IsTailscaleIP(addr.Addr()) {
tailscaleIPs = append(tailscaleIPs, addr.Addr())
}
}
exitNodeOption := tsaddr.PrefixesContainsFunc(p.AllowedIPs, func(r netip.Prefix) bool {
return r.Bits() == 0
})
var tags *views.Slice[string]
var primaryRoutes *views.IPPrefixSlice
if p.Tags != nil {
v := views.SliceOf(p.Tags)
tags = &v
}
if p.PrimaryRoutes != nil {
v := views.IPPrefixSliceOf(p.PrimaryRoutes)
primaryRoutes = &v
}
sb.AddPeer(p.Key, &ipnstate.PeerStatus{
InNetworkMap: true,
ID: p.StableID,
UserID: p.User,
TailscaleIPs: tailscaleIPs,
Tags: tags,
PrimaryRoutes: primaryRoutes,
HostName: p.Hostinfo.Hostname(),
DNSName: p.Name,
OS: p.Hostinfo.OS(),
KeepAlive: p.KeepAlive,
Created: p.Created,
LastSeen: lastSeen,
Online: p.Online != nil && *p.Online,
ShareeNode: p.Hostinfo.ShareeNode(),
ExitNode: p.StableID != "" && p.StableID == b.prefs.ExitNodeID,
ExitNodeOption: exitNodeOption,
SSH_HostKeys: p.Hostinfo.SSH_HostKeys().AsSlice(),
})
}
}
// WhoIs reports the node and user who owns the node with the given IP:port.
// If the IP address is a Tailscale IP, the provided port may be 0.
// If ok == true, n and u are valid.
func (b *LocalBackend) WhoIs(ipp netip.AddrPort) (n *tailcfg.Node, u tailcfg.UserProfile, ok bool) {
b.mu.Lock()
defer b.mu.Unlock()
n, ok = b.nodeByAddr[ipp.Addr()]
if !ok {
var ip netip.Addr
if ipp.Port() != 0 {
ip, ok = b.e.WhoIsIPPort(ipp)
}
if !ok {
return nil, u, false
}
n, ok = b.nodeByAddr[ip]
if !ok {
return nil, u, false
}
}
u, ok = b.netMap.UserProfiles[n.User]
if !ok {
return nil, u, false
}
return n, u, true
}
// PeerCaps returns the capabilities that remote src IP has to
// ths current node.
func (b *LocalBackend) PeerCaps(src netip.Addr) []string {
b.mu.Lock()
defer b.mu.Unlock()
return b.peerCapsLocked(src)
}
func (b *LocalBackend) peerCapsLocked(src netip.Addr) []string {
if b.netMap == nil {
return nil
}
filt := b.filterAtomic.Load()
if filt == nil {
return nil
}
for _, a := range b.netMap.Addresses {
if !a.IsSingleIP() {
continue
}
dst := a.Addr()
if dst.BitLen() == src.BitLen() { // match on family
return filt.AppendCaps(nil, src, dst)
}
}
return nil
}
// SetDecompressor sets a decompression function, which must be a zstd
// reader.
//
// This exists because the iOS/Mac NetworkExtension is very resource
// constrained, and the zstd package is too heavy to fit in the
// constrained RSS limit.
func (b *LocalBackend) SetDecompressor(fn func() (controlclient.Decompressor, error)) {
b.newDecompressor = fn
}
// setClientStatus is the callback invoked by the control client whenever it posts a new status.
// Among other things, this is where we update the netmap, packet filters, DNS and DERP maps.
func (b *LocalBackend) setClientStatus(st controlclient.Status) {
// The following do not depend on any data for which we need to lock b.
if st.Err != nil {
// TODO(crawshaw): display in the UI.
if errors.Is(st.Err, io.EOF) {
b.logf("[v1] Received error: EOF")
return
}
b.logf("Received error: %v", st.Err)
var uerr controlclient.UserVisibleError
if errors.As(st.Err, &uerr) {
s := uerr.UserVisibleError()
b.send(ipn.Notify{ErrMessage: &s})
}
return
}
b.mu.Lock()
wasBlocked := b.blocked
keyExpiryExtended := false
if st.NetMap != nil {
wasExpired := b.keyExpired
isExpired := !st.NetMap.Expiry.IsZero() && st.NetMap.Expiry.Before(time.Now())
if wasExpired && !isExpired {
keyExpiryExtended = true
}
b.keyExpired = isExpired
}
b.mu.Unlock()
if keyExpiryExtended && wasBlocked {
// Key extended, unblock the engine
b.blockEngineUpdates(false)
}
if st.LoginFinished != nil && wasBlocked {
// Auth completed, unblock the engine
b.blockEngineUpdates(false)
b.authReconfig()
b.send(ipn.Notify{LoginFinished: &empty.Message{}})
}
prefsChanged := false
// Lock b once and do only the things that require locking.
b.mu.Lock()
if st.LogoutFinished != nil {
// Since we're logged out now, our netmap cache is invalid.
// Since st.NetMap==nil means "netmap is unchanged", there is
// no other way to represent this change.
b.setNetMapLocked(nil)
b.e.SetNetworkMap(new(netmap.NetworkMap))
}
prefs := b.prefs
stateKey := b.stateKey
netMap := b.netMap
interact := b.interact
if prefs.ControlURL == "" {
// Once we get a message from the control plane, set
// our ControlURL pref explicitly. This causes a
// future "tailscale up" to start checking for
// implicit setting reverts, which it doesn't do when
// ControlURL is blank.
prefs.ControlURL = prefs.ControlURLOrDefault()
prefsChanged = true
}
if st.Persist != nil {
if !b.prefs.Persist.Equals(st.Persist) {
prefsChanged = true
b.prefs.Persist = st.Persist.Clone()
}
}
if st.NetMap != nil {
b.mu.Unlock() // respect locking rules for tkaSyncIfNeeded
if err := b.tkaSyncIfNeeded(st.NetMap); err != nil {
b.logf("[v1] TKA sync error: %v", err)
}
b.mu.Lock()
if !envknob.TKASkipSignatureCheck() {
b.tkaFilterNetmapLocked(st.NetMap)
}
if b.findExitNodeIDLocked(st.NetMap) {
prefsChanged = true
}
b.setNetMapLocked(st.NetMap)
}
if st.URL != "" {
b.authURL = st.URL
b.authURLSticky = st.URL
}
if wasBlocked && st.LoginFinished != nil {
// Interactive login finished successfully (URL visited).
// After an interactive login, the user always wants
// WantRunning.
if !b.prefs.WantRunning || b.prefs.LoggedOut {
prefsChanged = true
}
b.prefs.WantRunning = true
b.prefs.LoggedOut = false
}
// Prefs will be written out; this is not safe unless locked or cloned.
if prefsChanged {
prefs = b.prefs.Clone()
}
if st.NetMap != nil {
b.updateFilterLocked(st.NetMap, prefs)
}
b.mu.Unlock()
// Now complete the lock-free parts of what we started while locked.
if prefsChanged {
if stateKey != "" {
if err := b.store.WriteState(stateKey, prefs.ToBytes()); err != nil {
b.logf("Failed to save new controlclient state: %v", err)
}
}
b.send(ipn.Notify{Prefs: prefs})
}
if st.NetMap != nil {
if netMap != nil {
diff := st.NetMap.ConciseDiffFrom(netMap)
if strings.TrimSpace(diff) == "" {
b.logf("[v1] netmap diff: (none)")
} else {
b.logf("[v1] netmap diff:\n%v", diff)
}
}
b.e.SetNetworkMap(st.NetMap)
b.e.SetDERPMap(st.NetMap.DERPMap)
// Update our cached DERP map
dnsfallback.UpdateCache(st.NetMap.DERPMap)
b.send(ipn.Notify{NetMap: st.NetMap})
}
if st.URL != "" {
b.logf("Received auth URL: %.20v...", st.URL)
if interact {
b.popBrowserAuthNow()
}
}
b.stateMachine()
// This is currently (2020-07-28) necessary; conditionally disabling it is fragile!
// This is where netmap information gets propagated to router and magicsock.
b.authReconfig()
}
// findExitNodeIDLocked updates b.prefs to reference an exit node by ID,
// rather than by IP. It returns whether prefs was mutated.
func (b *LocalBackend) findExitNodeIDLocked(nm *netmap.NetworkMap) (prefsChanged bool) {
if nm == nil {
// No netmap, can't resolve anything.
return false
}
// If we have a desired IP on file, try to find the corresponding
// node.
if !b.prefs.ExitNodeIP.IsValid() {
return false
}
// IP takes precedence over ID, so if both are set, clear ID.
if b.prefs.ExitNodeID != "" {
b.prefs.ExitNodeID = ""
prefsChanged = true
}
for _, peer := range nm.Peers {
for _, addr := range peer.Addresses {
if !addr.IsSingleIP() || addr.Addr() != b.prefs.ExitNodeIP {
continue
}
// Found the node being referenced, upgrade prefs to
// reference it directly for next time.
b.prefs.ExitNodeID = peer.StableID
b.prefs.ExitNodeIP = netip.Addr{}
return true
}
}
return false
}
// setWgengineStatus is the callback by the wireguard engine whenever it posts a new status.
// This updates the endpoints both in the backend and in the control client.
func (b *LocalBackend) setWgengineStatus(s *wgengine.Status, err error) {
if err != nil {
b.logf("wgengine status error: %v", err)
b.broadcastStatusChanged()
return
}
if s == nil {
b.logf("[unexpected] non-error wgengine update with status=nil: %v", s)
b.broadcastStatusChanged()
return
}
b.mu.Lock()
if s.AsOf.Before(b.lastStatusTime) {
// Don't process a status update that is older than the one we have
// already processed. (corp#2579)
b.mu.Unlock()
return
}
b.lastStatusTime = s.AsOf
es := b.parseWgStatusLocked(s)
cc := b.cc
b.engineStatus = es
needUpdateEndpoints := !endpointsEqual(s.LocalAddrs, b.endpoints)
if needUpdateEndpoints {
b.endpoints = append([]tailcfg.Endpoint{}, s.LocalAddrs...)
}
b.mu.Unlock()
if cc != nil {
if needUpdateEndpoints {
cc.UpdateEndpoints(s.LocalAddrs)
}
b.stateMachine()
}
b.broadcastStatusChanged()
b.send(ipn.Notify{Engine: &es})
}
func (b *LocalBackend) broadcastStatusChanged() {
// The sync.Cond docs say: "It is allowed but not required for the caller to hold c.L during the call."
// In this particular case, we must acquire b.statusLock. Otherwise we might broadcast before
// the waiter (in requestEngineStatusAndWait) starts to wait, in which case
// the waiter can get stuck indefinitely. See PR 2865.
b.statusLock.Lock()
b.statusChanged.Broadcast()
b.statusLock.Unlock()
}
func endpointsEqual(x, y []tailcfg.Endpoint) bool {
if len(x) != len(y) {
return false
}
for i := range x {
if x[i] != y[i] {
return false
}
}
return true
}
func (b *LocalBackend) SetNotifyCallback(notify func(ipn.Notify)) {
b.mu.Lock()
defer b.mu.Unlock()
b.notify = notify
}
// SetHTTPTestClient sets an alternate HTTP client to use with
// connections to the coordination server. It exists for
// testing. Using nil means to use the default.
func (b *LocalBackend) SetHTTPTestClient(c *http.Client) {
b.mu.Lock()
defer b.mu.Unlock()
b.httpTestClient = c
}
// SetControlClientGetterForTesting sets the func that creates a
// control plane client. It can be called at most once, before Start.
func (b *LocalBackend) SetControlClientGetterForTesting(newControlClient func(controlclient.Options) (controlclient.Client, error)) {
b.mu.Lock()
defer b.mu.Unlock()
if b.ccGen != nil {
panic("invalid use of SetControlClientGetterForTesting after Start")
}
b.ccGen = newControlClient
}
func (b *LocalBackend) getNewControlClientFunc() clientGen {
b.mu.Lock()
defer b.mu.Unlock()
if b.ccGen == nil {
// Initialize it rather than just returning the
// default to make any future call to
// SetControlClientGetterForTesting panic.
b.ccGen = func(opts controlclient.Options) (controlclient.Client, error) {
return controlclient.New(opts)
}
}
return b.ccGen
}
// startIsNoopLocked reports whether a Start call on this LocalBackend
// with the provided Start Options would be a useless no-op.
//
// TODO(apenwarr): we shouldn't need this. The state machine is now
// nearly clean enough where it can accept a new connection while in
// any state, not just Running, and on any platform. We'd want to add
// a few more tests to state_test.go to ensure this continues to work
// as expected.
//
// b.mu must be held.
func (b *LocalBackend) startIsNoopLocked(opts ipn.Options) bool {
// Options has 5 fields; check all of them:
// * FrontendLogID
// * StateKey
// * Prefs
// * UpdatePrefs
// * AuthKey
return b.state == ipn.Running &&
b.hostinfo != nil &&
b.hostinfo.FrontendLogID == opts.FrontendLogID &&
b.stateKey == opts.StateKey &&
opts.Prefs == nil &&
opts.UpdatePrefs == nil &&
opts.AuthKey == ""
}
// Start applies the configuration specified in opts, and starts the
// state machine.
//
// TODO(danderson): this function is trying to do too many things at
// once: it loads state, or imports it, or updates prefs sometimes,
// contains some settings that are one-shot things done by `tailscale
// up` because we had nowhere else to put them, and there's no clear
// guarantee that switching from one user's state to another is
// actually a supported operation (it should be, but it's very unclear
// from the following whether or not that is a safe transition).
func (b *LocalBackend) Start(opts ipn.Options) error {
if opts.Prefs == nil && opts.StateKey == "" {
return errors.New("no state key or prefs provided")
}
if opts.Prefs != nil {
b.logf("Start: %v", opts.Prefs.Pretty())
} else {
b.logf("Start")
}
b.mu.Lock()
// The iOS client sends a "Start" whenever its UI screen comes
// up, just because it wants a netmap. That should be fixed,
// but meanwhile we can make Start cheaper here for such a
// case and not restart the world (which takes a few seconds).
// Instead, just send a notify with the state that iOS needs.
if b.startIsNoopLocked(opts) {
b.logf("Start: already running; sending notify")
nm := b.netMap
state := b.state
b.mu.Unlock()
b.send(ipn.Notify{
State: &state,
NetMap: nm,
Prefs: b.prefs,
LoginFinished: new(empty.Message),
})
return nil
}
hostinfo := hostinfo.New()
hostinfo.BackendLogID = b.backendLogID
hostinfo.FrontendLogID = opts.FrontendLogID
hostinfo.Userspace.Set(wgengine.IsNetstack(b.e))
hostinfo.UserspaceRouter.Set(wgengine.IsNetstackRouter(b.e))
if b.cc != nil {
// TODO(apenwarr): avoid the need to reinit controlclient.
// This will trigger a full relogin/reconfigure cycle every
// time a Handle reconnects to the backend. Ideally, we
// would send the new Prefs and everything would get back
// into sync with the minimal changes. But that's not how it
// is right now, which is a sign that the code is still too
// complicated.
b.mu.Unlock()
b.cc.Shutdown()
b.mu.Lock()
}
httpTestClient := b.httpTestClient
if b.hostinfo != nil {
hostinfo.Services = b.hostinfo.Services // keep any previous services
}
b.hostinfo = hostinfo
b.state = ipn.NoState
if err := b.loadStateLocked(opts.StateKey, opts.Prefs); err != nil {
b.mu.Unlock()
return fmt.Errorf("loading requested state: %v", err)
}
if opts.UpdatePrefs != nil {
newPrefs := opts.UpdatePrefs
newPrefs.Persist = b.prefs.Persist
b.prefs = newPrefs
if opts.StateKey != "" {
if err := b.store.WriteState(opts.StateKey, b.prefs.ToBytes()); err != nil {
b.logf("failed to save UpdatePrefs state: %v", err)
}
}
b.setAtomicValuesFromPrefs(b.prefs)
}
wantRunning := b.prefs.WantRunning
if wantRunning {
if err := b.initMachineKeyLocked(); err != nil {
return fmt.Errorf("initMachineKeyLocked: %w", err)
}
}
if err := b.initNLKeyLocked(); err != nil {
return fmt.Errorf("initNLKeyLocked: %w", err)
}
loggedOut := b.prefs.LoggedOut
b.inServerMode = b.prefs.ForceDaemon
b.serverURL = b.prefs.ControlURLOrDefault()
if b.inServerMode || runtime.GOOS == "windows" {
b.logf("Start: serverMode=%v", b.inServerMode)
}
b.applyPrefsToHostinfo(hostinfo, b.prefs)
b.setNetMapLocked(nil)
persistv := b.prefs.Persist
b.updateFilterLocked(nil, nil)
b.mu.Unlock()
if b.portpoll != nil {
b.portpollOnce.Do(func() {
go b.portpoll.Run(b.ctx)
go b.readPoller()
// Give the poller a second to get results to
// prevent it from restarting our map poll
// HTTP request (via doSetHostinfoFilterServices >
// cli.SetHostinfo). In practice this is very quick.
t0 := time.Now()
timer := time.NewTimer(time.Second)
select {
case <-b.gotPortPollRes:
b.logf("[v1] got initial portlist info in %v", time.Since(t0).Round(time.Millisecond))
timer.Stop()
case <-timer.C:
b.logf("timeout waiting for initial portlist")
}
})
}
discoPublic := b.e.DiscoPublicKey()
var err error
if persistv == nil {
// let controlclient initialize it
persistv = &persist.Persist{}
}
isNetstack := wgengine.IsNetstackRouter(b.e)
debugFlags := controlDebugFlags
if isNetstack {
debugFlags = append([]string{"netstack"}, debugFlags...)
}
// TODO(apenwarr): The only way to change the ServerURL is to
// re-run b.Start(), because this is the only place we create a
// new controlclient. SetPrefs() allows you to overwrite ServerURL,
// but it won't take effect until the next Start().
cc, err := b.getNewControlClientFunc()(controlclient.Options{
GetMachinePrivateKey: b.createGetMachinePrivateKeyFunc(),
GetNLPrivateKey: b.createGetNLPrivateKeyFunc(),
Logf: logger.WithPrefix(b.logf, "control: "),
Persist: *persistv,
ServerURL: b.serverURL,
AuthKey: opts.AuthKey,
Hostinfo: hostinfo,
KeepAlive: true,
NewDecompressor: b.newDecompressor,
HTTPTestClient: httpTestClient,
DiscoPublicKey: discoPublic,
DebugFlags: debugFlags,
LinkMonitor: b.e.GetLinkMonitor(),
Pinger: b,
PopBrowserURL: b.tellClientToBrowseToURL,
Dialer: b.Dialer(),
Status: b.setClientStatus,
C2NHandler: http.HandlerFunc(b.handleC2N),
DialPlan: &b.dialPlan, // pointer because it can't be copied
// Don't warn about broken Linux IP forwarding when
// netstack is being used.
SkipIPForwardingCheck: isNetstack,
})
if err != nil {
return err
}
b.mu.Lock()
b.cc = cc
b.ccAuto, _ = cc.(*controlclient.Auto)
endpoints := b.endpoints
b.mu.Unlock()
if endpoints != nil {
cc.UpdateEndpoints(endpoints)
}
b.e.SetNetInfoCallback(b.setNetInfo)
b.mu.Lock()
prefs := b.prefs.Clone()
b.mu.Unlock()
blid := b.backendLogID
b.logf("Backend: logs: be:%v fe:%v", blid, opts.FrontendLogID)
b.send(ipn.Notify{BackendLogID: &blid})
b.send(ipn.Notify{Prefs: prefs})
if !loggedOut && b.hasNodeKey() {
// Even if !WantRunning, we should verify our key, if there
// is one. If you want tailscaled to be completely idle,
// use logout instead.
cc.Login(nil, controlclient.LoginDefault)
}
b.stateMachine()
return nil
}
// updateFilterLocked updates the packet filter in wgengine based on the
// given netMap and user preferences.
//
// b.mu must be held.
func (b *LocalBackend) updateFilterLocked(netMap *netmap.NetworkMap, prefs *ipn.Prefs) {
// NOTE(danderson): keep change detection as the first thing in
// this function. Don't try to optimize by returning early, more
// likely than not you'll just end up breaking the change
// detection and end up with the wrong filter installed. This is
// quite hard to debug, so save yourself the trouble.
var (
haveNetmap = netMap != nil
addrs []netip.Prefix
packetFilter []filter.Match
localNetsB netipx.IPSetBuilder
logNetsB netipx.IPSetBuilder
shieldsUp = prefs == nil || prefs.ShieldsUp // Be conservative when not ready
)
// Log traffic for Tailscale IPs.
logNetsB.AddPrefix(tsaddr.CGNATRange())
logNetsB.AddPrefix(tsaddr.TailscaleULARange())
logNetsB.RemovePrefix(tsaddr.ChromeOSVMRange())
if haveNetmap {
addrs = netMap.Addresses
for _, p := range addrs {
localNetsB.AddPrefix(p)
}
packetFilter = netMap.PacketFilter
}
if prefs != nil {
for _, r := range prefs.AdvertiseRoutes {
if r.Bits() == 0 {
// When offering a default route to the world, we
// filter out locally reachable LANs, so that the
// default route effectively appears to be a "guest
// wifi": you get internet access, but to additionally
// get LAN access the LAN(s) need to be offered
// explicitly as well.
localInterfaceRoutes, hostIPs, err := interfaceRoutes()
if err != nil {
b.logf("getting local interface routes: %v", err)
continue
}
s, err := shrinkDefaultRoute(r, localInterfaceRoutes, hostIPs)
if err != nil {
b.logf("computing default route filter: %v", err)
continue
}
localNetsB.AddSet(s)
} else {
localNetsB.AddPrefix(r)
// When advertising a non-default route, we assume
// this is a corporate subnet that should be present
// in the audit logs.
logNetsB.AddPrefix(r)
}
}
}
localNets, _ := localNetsB.IPSet()
logNets, _ := logNetsB.IPSet()
var sshPol tailcfg.SSHPolicy
if haveNetmap && netMap.SSHPolicy != nil {
sshPol = *netMap.SSHPolicy
}
changed := deephash.Update(&b.filterHash, &struct {
HaveNetmap bool
Addrs []netip.Prefix
FilterMatch []filter.Match
LocalNets []netipx.IPRange
LogNets []netipx.IPRange
ShieldsUp bool
SSHPolicy tailcfg.SSHPolicy
}{haveNetmap, addrs, packetFilter, localNets.Ranges(), logNets.Ranges(), shieldsUp, sshPol})
if !changed {
return
}
if !haveNetmap {
b.logf("[v1] netmap packet filter: (not ready yet)")
b.setFilter(filter.NewAllowNone(b.logf, logNets))
return
}
oldFilter := b.e.GetFilter()
if shieldsUp {
b.logf("[v1] netmap packet filter: (shields up)")
b.setFilter(filter.NewShieldsUpFilter(localNets, logNets, oldFilter, b.logf))
} else {
b.logf("[v1] netmap packet filter: %v filters", len(packetFilter))
b.setFilter(filter.New(packetFilter, localNets, logNets, oldFilter, b.logf))
}
if b.sshServer != nil {
go b.sshServer.OnPolicyChange()
}
}
func (b *LocalBackend) setFilter(f *filter.Filter) {
b.filterAtomic.Store(f)
b.e.SetFilter(f)
}
var removeFromDefaultRoute = []netip.Prefix{
// RFC1918 LAN ranges
netip.MustParsePrefix("192.168.0.0/16"),
netip.MustParsePrefix("172.16.0.0/12"),
netip.MustParsePrefix("10.0.0.0/8"),
// IPv4 link-local
netip.MustParsePrefix("169.254.0.0/16"),
// IPv4 multicast
netip.MustParsePrefix("224.0.0.0/4"),
// Tailscale IPv4 range
tsaddr.CGNATRange(),
// IPv6 Link-local addresses
netip.MustParsePrefix("fe80::/10"),
// IPv6 multicast
netip.MustParsePrefix("ff00::/8"),
// Tailscale IPv6 range
tsaddr.TailscaleULARange(),
}
// internalAndExternalInterfaces splits interface routes into "internal"
// and "external" sets. Internal routes are those of virtual ethernet
// network interfaces used by guest VMs and containers, such as WSL and
// Docker.
//
// Given that "internal" routes don't leave the device, we choose to
// trust them more, allowing access to them when an Exit Node is enabled.
func internalAndExternalInterfaces() (internal, external []netip.Prefix, err error) {
il, err := interfaces.GetList()
if err != nil {
return nil, nil, err
}
return internalAndExternalInterfacesFrom(il, runtime.GOOS)
}
func internalAndExternalInterfacesFrom(il interfaces.List, goos string) (internal, external []netip.Prefix, err error) {
// We use an IPSetBuilder here to canonicalize the prefixes
// and to remove any duplicate entries.
var internalBuilder, externalBuilder netipx.IPSetBuilder
if err := il.ForeachInterfaceAddress(func(iface interfaces.Interface, pfx netip.Prefix) {
if tsaddr.IsTailscaleIP(pfx.Addr()) {
return
}
if pfx.IsSingleIP() {
return
}
if iface.IsLoopback() {
internalBuilder.AddPrefix(pfx)
return
}
if goos == "windows" {
// Windows Hyper-V prefixes all MAC addresses with 00:15:5d.
// https://docs.microsoft.com/en-us/troubleshoot/windows-server/virtualization/default-limit-256-dynamic-mac-addresses
//
// This includes WSL2 vEthernet.
// Importantly: by default WSL2 /etc/resolv.conf points to
// a stub resolver running on the host vEthernet IP.
// So enabling exit nodes with the default tailnet
// configuration breaks WSL2 DNS without this.
mac := iface.Interface.HardwareAddr
if len(mac) == 6 && mac[0] == 0x00 && mac[1] == 0x15 && mac[2] == 0x5d {
internalBuilder.AddPrefix(pfx)
return
}
}
externalBuilder.AddPrefix(pfx)
}); err != nil {
return nil, nil, err
}
iSet, err := internalBuilder.IPSet()
if err != nil {
return nil, nil, err
}
eSet, err := externalBuilder.IPSet()
if err != nil {
return nil, nil, err
}
return iSet.Prefixes(), eSet.Prefixes(), nil
}
func interfaceRoutes() (ips *netipx.IPSet, hostIPs []netip.Addr, err error) {
var b netipx.IPSetBuilder
if err := interfaces.ForeachInterfaceAddress(func(_ interfaces.Interface, pfx netip.Prefix) {
if tsaddr.IsTailscaleIP(pfx.Addr()) {
return
}
if pfx.IsSingleIP() {
return
}
hostIPs = append(hostIPs, pfx.Addr())
b.AddPrefix(pfx)
}); err != nil {
return nil, nil, err
}
ipSet, _ := b.IPSet()
return ipSet, hostIPs, nil
}
// shrinkDefaultRoute returns an IPSet representing the IPs in route,
// minus those in removeFromDefaultRoute and localInterfaceRoutes,
// plus the IPs in hostIPs.
func shrinkDefaultRoute(route netip.Prefix, localInterfaceRoutes *netipx.IPSet, hostIPs []netip.Addr) (*netipx.IPSet, error) {
var b netipx.IPSetBuilder
// Add the default route.
b.AddPrefix(route)
// Remove the local interface routes.
b.RemoveSet(localInterfaceRoutes)
// Having removed all the LAN subnets, re-add the hosts's own
// IPs. It's fine for clients to connect to an exit node's public
// IP address, just not the attached subnet.
//
// Truly forbidden subnets (in removeFromDefaultRoute) will still
// be stripped back out by the next step.
for _, ip := range hostIPs {
if route.Contains(ip) {
b.Add(ip)
}
}
for _, pfx := range removeFromDefaultRoute {
b.RemovePrefix(pfx)
}
return b.IPSet()
}
// dnsCIDRsEqual determines whether two CIDR lists are equal
// for DNS map construction purposes (that is, only the first entry counts).
func dnsCIDRsEqual(newAddr, oldAddr []netip.Prefix) bool {
if len(newAddr) != len(oldAddr) {
return false
}
if len(newAddr) == 0 || newAddr[0] == oldAddr[0] {
return true
}
return false
}
// dnsMapsEqual determines whether the new and the old network map
// induce the same DNS map. It does so without allocating memory,
// at the expense of giving false negatives if peers are reordered.
func dnsMapsEqual(new, old *netmap.NetworkMap) bool {
if (old == nil) != (new == nil) {
return false
}
if old == nil && new == nil {
return true
}
if len(new.Peers) != len(old.Peers) {
return false
}
if new.Name != old.Name {
return false
}
if !dnsCIDRsEqual(new.Addresses, old.Addresses) {
return false
}
for i, newPeer := range new.Peers {
oldPeer := old.Peers[i]
if newPeer.Name != oldPeer.Name {
return false
}
if !dnsCIDRsEqual(newPeer.Addresses, oldPeer.Addresses) {
return false
}
}
return true
}
// readPoller is a goroutine that receives service lists from
// b.portpoll and propagates them into the controlclient's HostInfo.
func (b *LocalBackend) readPoller() {
n := 0
for {
ports, ok := <-b.portpoll.C
if !ok {
return
}
sl := []tailcfg.Service{}
for _, p := range ports {
s := tailcfg.Service{
Proto: tailcfg.ServiceProto(p.Proto),
Port: p.Port,
Description: p.Process,
}
if policy.IsInterestingService(s, version.OS()) {
sl = append(sl, s)
}
}
b.mu.Lock()
if b.hostinfo == nil {
b.hostinfo = new(tailcfg.Hostinfo)
}
b.hostinfo.Services = sl
hi := b.hostinfo
b.mu.Unlock()
b.doSetHostinfoFilterServices(hi)
n++
if n == 1 {
close(b.gotPortPollRes)
}
}
}
// send delivers n to the connected frontend. If no frontend is
// connected, the notification is dropped without being delivered.
func (b *LocalBackend) send(n ipn.Notify) {
b.mu.Lock()
notifyFunc := b.notify
apiSrv := b.peerAPIServer
b.mu.Unlock()
if notifyFunc == nil {
return
}
if apiSrv.hasFilesWaiting() {
n.FilesWaiting = &empty.Message{}
}
n.Version = version.Long
notifyFunc(n)
}
func (b *LocalBackend) sendFileNotify() {
var n ipn.Notify
b.mu.Lock()
notifyFunc := b.notify
apiSrv := b.peerAPIServer
if notifyFunc == nil || apiSrv == nil {
b.mu.Unlock()
return
}
// Make sure we always set n.IncomingFiles non-nil so it gets encoded
// in JSON to clients. They distinguish between empty and non-nil
// to know whether a Notify should be able about files.
n.IncomingFiles = make([]ipn.PartialFile, 0)
for f := range b.incomingFiles {
n.IncomingFiles = append(n.IncomingFiles, f.PartialFile())
}
b.mu.Unlock()
sort.Slice(n.IncomingFiles, func(i, j int) bool {
return n.IncomingFiles[i].Started.Before(n.IncomingFiles[j].Started)
})
b.send(n)
}
// popBrowserAuthNow shuts down the data plane and sends an auth URL
// to the connected frontend, if any.
func (b *LocalBackend) popBrowserAuthNow() {
b.mu.Lock()
url := b.authURL
b.interact = false
b.authURL = "" // but NOT clearing authURLSticky
b.mu.Unlock()
b.logf("popBrowserAuthNow: url=%v", url != "")
b.blockEngineUpdates(true)
b.stopEngineAndWait()
b.tellClientToBrowseToURL(url)
if b.State() == ipn.Running {
b.enterState(ipn.Starting)
}
}
func (b *LocalBackend) tellClientToBrowseToURL(url string) {
if url != "" {
b.send(ipn.Notify{BrowseToURL: &url})
}
}
// For testing lazy machine key generation.
var panicOnMachineKeyGeneration = envknob.RegisterBool("TS_DEBUG_PANIC_MACHINE_KEY")
func (b *LocalBackend) createGetMachinePrivateKeyFunc() func() (key.MachinePrivate, error) {
var cache syncs.AtomicValue[key.MachinePrivate]
return func() (key.MachinePrivate, error) {
if panicOnMachineKeyGeneration() {
panic("machine key generated")
}
if v, ok := cache.LoadOk(); ok {
return v, nil
}
b.mu.Lock()
defer b.mu.Unlock()
if v, ok := cache.LoadOk(); ok {
return v, nil
}
if err := b.initMachineKeyLocked(); err != nil {
return key.MachinePrivate{}, err
}
cache.Store(b.machinePrivKey)
return b.machinePrivKey, nil
}
}
func (b *LocalBackend) createGetNLPrivateKeyFunc() func() (key.NLPrivate, error) {
var cache syncs.AtomicValue[key.NLPrivate]
return func() (key.NLPrivate, error) {
b.mu.Lock()
defer b.mu.Unlock()
if v, ok := cache.LoadOk(); ok {
return v, nil
}
priv := b.nlPrivKey
cache.Store(priv)
return priv, nil
}
}
// initMachineKeyLocked is called to initialize b.machinePrivKey.
//
// b.prefs must already be initialized.
// b.stateKey should be set too, but just for nicer log messages.
// b.mu must be held.
func (b *LocalBackend) initMachineKeyLocked() (err error) {
if !b.machinePrivKey.IsZero() {
// Already set.
return nil
}
var legacyMachineKey key.MachinePrivate
if b.prefs.Persist != nil {
legacyMachineKey = b.prefs.Persist.LegacyFrontendPrivateMachineKey
}
keyText, err := b.store.ReadState(ipn.MachineKeyStateKey)
if err == nil {
if err := b.machinePrivKey.UnmarshalText(keyText); err != nil {
return fmt.Errorf("invalid key in %s key of %v: %w", ipn.MachineKeyStateKey, b.store, err)
}
if b.machinePrivKey.IsZero() {
return fmt.Errorf("invalid zero key stored in %v key of %v", ipn.MachineKeyStateKey, b.store)
}
if !legacyMachineKey.IsZero() && !legacyMachineKey.Equal(b.machinePrivKey) {
b.logf("frontend-provided legacy machine key ignored; used value from server state")
}
return nil
}
if err != ipn.ErrStateNotExist {
return fmt.Errorf("error reading %v key of %v: %w", ipn.MachineKeyStateKey, b.store, err)
}
// If we didn't find one already on disk and the prefs already
// have a legacy machine key, use that. Otherwise generate a
// new one.
if !legacyMachineKey.IsZero() {
if b.stateKey == "" {
b.logf("using frontend-provided legacy machine key")
} else {
b.logf("using legacy machine key from state key %q", b.stateKey)
}
b.machinePrivKey = legacyMachineKey
} else {
b.logf("generating new machine key")
b.machinePrivKey = key.NewMachine()
}
keyText, _ = b.machinePrivKey.MarshalText()
if err := b.store.WriteState(ipn.MachineKeyStateKey, keyText); err != nil {
b.logf("error writing machine key to store: %v", err)
return err
}
b.logf("machine key written to store")
return nil
}
// initNLKeyLocked is called to initialize b.nlPrivKey.
//
// b.prefs must already be initialized.
// b.stateKey should be set too, but just for nicer log messages.
// b.mu must be held.
func (b *LocalBackend) initNLKeyLocked() (err error) {
if !b.nlPrivKey.IsZero() {
// Already set.
return nil
}
keyText, err := b.store.ReadState(ipn.NLKeyStateKey)
if err == nil {
if err := b.nlPrivKey.UnmarshalText(keyText); err != nil {
return fmt.Errorf("invalid key in %s key of %v: %w", ipn.NLKeyStateKey, b.store, err)
}
if b.nlPrivKey.IsZero() {
return fmt.Errorf("invalid zero key stored in %v key of %v", ipn.NLKeyStateKey, b.store)
}
return nil
}
if err != ipn.ErrStateNotExist {
return fmt.Errorf("error reading %v key of %v: %w", ipn.NLKeyStateKey, b.store, err)
}
// If we didn't find one already on disk, generate a new one.
b.logf("generating new network-lock key")
b.nlPrivKey = key.NewNLPrivate()
keyText, _ = b.nlPrivKey.MarshalText()
if err := b.store.WriteState(ipn.NLKeyStateKey, keyText); err != nil {
b.logf("error writing network-lock key to store: %v", err)
return err
}
b.logf("network-lock key written to store")
return nil
}
// writeServerModeStartState stores the ServerModeStartKey value based on the current
// user and prefs. If userID is blank or prefs is blank, no work is done.
//
// b.mu may either be held or not.
func (b *LocalBackend) writeServerModeStartState(userID string, prefs *ipn.Prefs) {
if userID == "" || prefs == nil {
return
}
if prefs.ForceDaemon {
stateKey := ipn.StateKey("user-" + userID)
if err := b.store.WriteState(ipn.ServerModeStartKey, []byte(stateKey)); err != nil {
b.logf("WriteState error: %v", err)
}
// It's important we do this here too, even if it looks
// redundant with the one in the 'if stateKey != ""'
// check block above. That one won't fire in the case
// where the Windows client started up in client mode.
// This happens when we transition into server mode:
if err := b.store.WriteState(stateKey, prefs.ToBytes()); err != nil {
b.logf("WriteState error: %v", err)
}
} else {
if err := b.store.WriteState(ipn.ServerModeStartKey, nil); err != nil {
b.logf("WriteState error: %v", err)
}
}
}
// loadStateLocked sets b.prefs and b.stateKey based on a complex
// combination of key, prefs, and legacyPath. b.mu must be held when
// calling.
func (b *LocalBackend) loadStateLocked(key ipn.StateKey, prefs *ipn.Prefs) (err error) {
if prefs == nil && key == "" {
panic("state key and prefs are both unset")
}
// Optimistically set stateKey (for initMachineKeyLocked's
// logging), but revert it if we return an error so a later SetPrefs
// call can't pick it up if it's bogus.
b.stateKey = key
defer func() {
if err != nil {
b.stateKey = ""
}
}()
if key == "" {
// Frontend owns the state, we just need to obey it.
//
// If the frontend (e.g. on Windows) supplied the
// optional/legacy machine key then it's used as the
// value instead of making up a new one.
b.logf("using frontend prefs: %s", prefs.Pretty())
b.prefs = prefs.Clone()
b.writeServerModeStartState(b.userID, b.prefs)
return nil
}
if prefs != nil {
// Backend owns the state, but frontend is trying to migrate
// state into the backend.
b.logf("importing frontend prefs into backend store; frontend prefs: %s", prefs.Pretty())
if err := b.store.WriteState(key, prefs.ToBytes()); err != nil {
return fmt.Errorf("store.WriteState: %v", err)
}
}
bs, err := b.store.ReadState(key)
switch {
case errors.Is(err, ipn.ErrStateNotExist):
b.prefs = ipn.NewPrefs()
b.prefs.WantRunning = false
b.logf("using backend prefs; created empty state for %q: %s", key, b.prefs.Pretty())
return nil
case err != nil:
return fmt.Errorf("backend prefs: store.ReadState(%q): %v", key, err)
}
b.prefs, err = ipn.PrefsFromBytes(bs)
if err != nil {
b.logf("using backend prefs for %q", key)
return fmt.Errorf("PrefsFromBytes: %v", err)
}
// Ignore any old stored preferences for https://login.tailscale.com
// as the control server that would override the new default of
// controlplane.tailscale.com.
// This makes sure that mobile clients go through the new
// frontends where we're (2021-10-02) doing battery
// optimization work ahead of turning down the old backends.
if b.prefs != nil && b.prefs.ControlURL != "" &&
b.prefs.ControlURL != ipn.DefaultControlURL &&
ipn.IsLoginServerSynonym(b.prefs.ControlURL) {
b.prefs.ControlURL = ""
}
b.logf("using backend prefs for %q: %s", key, b.prefs.Pretty())
b.setAtomicValuesFromPrefs(b.prefs)
return nil
}
// setAtomicValuesFromPrefs populates sshAtomicBool and containsViaIPFuncAtomic
// from the prefs p, which may be nil.
func (b *LocalBackend) setAtomicValuesFromPrefs(p *ipn.Prefs) {
b.sshAtomicBool.Store(p != nil && p.RunSSH && envknob.CanSSHD())
if p == nil {
b.containsViaIPFuncAtomic.Store(tsaddr.NewContainsIPFunc(nil))
} else {
b.containsViaIPFuncAtomic.Store(tsaddr.NewContainsIPFunc(tsaddr.FilterPrefixesCopy(p.AdvertiseRoutes, tsaddr.IsViaPrefix)))
}
}
// State returns the backend state machine's current state.
func (b *LocalBackend) State() ipn.State {
b.mu.Lock()
defer b.mu.Unlock()
return b.state
}
func (b *LocalBackend) InServerMode() bool {
b.mu.Lock()
defer b.mu.Unlock()
return b.inServerMode
}
// Login implements Backend.
// As of 2022-02-17, this is only exists for tests.
func (b *LocalBackend) Login(token *tailcfg.Oauth2Token) {
b.mu.Lock()
b.assertClientLocked()
cc := b.cc
b.mu.Unlock()
cc.Login(token, b.loginFlags|controlclient.LoginInteractive)
}
// StartLoginInteractive implements Backend. It requests a new
// interactive login from controlclient, unless such a flow is already
// in progress, in which case StartLoginInteractive attempts to pick
// up the in-progress flow where it left off.
func (b *LocalBackend) StartLoginInteractive() {
b.mu.Lock()
b.assertClientLocked()
b.interact = true
url := b.authURL
cc := b.cc
b.mu.Unlock()
b.logf("StartLoginInteractive: url=%v", url != "")
if url != "" {
b.popBrowserAuthNow()
} else {
cc.Login(nil, b.loginFlags|controlclient.LoginInteractive)
}
}
func (b *LocalBackend) Ping(ctx context.Context, ip netip.Addr, pingType tailcfg.PingType) (*ipnstate.PingResult, error) {
if pingType == tailcfg.PingPeerAPI {
t0 := time.Now()
node, base, err := b.pingPeerAPI(ctx, ip)
if err != nil && ctx.Err() != nil {
return nil, ctx.Err()
}
d := time.Since(t0)
pr := &ipnstate.PingResult{
IP: ip.String(),
NodeIP: ip.String(),
LatencySeconds: d.Seconds(),
PeerAPIURL: base,
}
if err != nil {
pr.Err = err.Error()
}
if node != nil {
pr.NodeName = node.Name
}
return pr, nil
}
ch := make(chan *ipnstate.PingResult, 1)
b.e.Ping(ip, pingType, func(pr *ipnstate.PingResult) {
select {
case ch <- pr:
default:
}
})
select {
case pr := <-ch:
return pr, nil
case <-ctx.Done():
return nil, ctx.Err()
}
}
func (b *LocalBackend) pingPeerAPI(ctx context.Context, ip netip.Addr) (peer *tailcfg.Node, peerBase string, err error) {
ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
defer cancel()
nm := b.NetMap()
if nm == nil {
return nil, "", errors.New("no netmap")
}
peer, ok := nm.PeerByTailscaleIP(ip)
if !ok {
return nil, "", fmt.Errorf("no peer found with Tailscale IP %v", ip)
}
base := peerAPIBase(nm, peer)
if base == "" {
return nil, "", fmt.Errorf("no peer API base found for peer %v (%v)", peer.ID, ip)
}
outReq, err := http.NewRequestWithContext(ctx, "HEAD", base, nil)
if err != nil {
return nil, "", err
}
tr := b.Dialer().PeerAPITransport()
res, err := tr.RoundTrip(outReq)
if err != nil {
return nil, "", err
}
defer res.Body.Close() // but unnecessary on HEAD responses
if res.StatusCode != http.StatusOK {
return nil, "", fmt.Errorf("HTTP status %v", res.Status)
}
return peer, base, nil
}
// parseWgStatusLocked returns an EngineStatus based on s.
//
// b.mu must be held; mostly because the caller is about to anyway, and doing so
// gives us slightly better guarantees about the two peers stats lines not
// being intermixed if there are concurrent calls to our caller.
func (b *LocalBackend) parseWgStatusLocked(s *wgengine.Status) (ret ipn.EngineStatus) {
var peerStats, peerKeys strings.Builder
ret.LiveDERPs = s.DERPs
ret.LivePeers = map[key.NodePublic]ipnstate.PeerStatusLite{}
for _, p := range s.Peers {
if !p.LastHandshake.IsZero() {
fmt.Fprintf(&peerStats, "%d/%d ", p.RxBytes, p.TxBytes)
fmt.Fprintf(&peerKeys, "%s ", p.NodeKey.ShortString())
ret.NumLive++
ret.LivePeers[p.NodeKey] = p
}
ret.RBytes += p.RxBytes
ret.WBytes += p.TxBytes
}
// [GRINDER STATS LINES] - please don't remove (used for log parsing)
if peerStats.Len() > 0 {
b.keyLogf("[v1] peer keys: %s", strings.TrimSpace(peerKeys.String()))
b.statsLogf("[v1] v%v peers: %v", version.Long, strings.TrimSpace(peerStats.String()))
}
return ret
}
// shouldUploadServices reports whether this node should include services
// in Hostinfo. When the user preferences currently request "shields up"
// mode, all inbound connections are refused, so services are not reported.
// Otherwise, shouldUploadServices respects NetMap.CollectServices.
func (b *LocalBackend) shouldUploadServices() bool {
b.mu.Lock()
defer b.mu.Unlock()
if b.prefs == nil || b.netMap == nil {
return false // default to safest setting
}
return !b.prefs.ShieldsUp && b.netMap.CollectServices
}
func (b *LocalBackend) SetCurrentUserID(uid string) {
b.mu.Lock()
b.userID = uid
b.mu.Unlock()
}
func (b *LocalBackend) CheckPrefs(p *ipn.Prefs) error {
b.mu.Lock()
defer b.mu.Unlock()
return b.checkPrefsLocked(p)
}
func (b *LocalBackend) checkPrefsLocked(p *ipn.Prefs) error {
var errs []error
if p.Hostname == "badhostname.tailscale." {
// Keep this one just for testing.
errs = append(errs, errors.New("bad hostname [test]"))
}
if err := b.checkSSHPrefsLocked(p); err != nil {
errs = append(errs, err)
}
return multierr.New(errs...)
}
func (b *LocalBackend) checkSSHPrefsLocked(p *ipn.Prefs) error {
if !p.RunSSH {
return nil
}
switch runtime.GOOS {
case "linux":
if distro.Get() == distro.Synology && !envknob.UseWIPCode() {
return errors.New("The Tailscale SSH server does not run on Synology.")
}
if distro.Get() == distro.QNAP && !envknob.UseWIPCode() {
return errors.New("The Tailscale SSH server does not run on QNAP.")
}
// otherwise okay
case "darwin":
// okay only in tailscaled mode for now.
if version.IsSandboxedMacOS() {
return errors.New("The Tailscale SSH server does not run in sandboxed Tailscale GUI builds.")
}
if !envknob.UseWIPCode() {
return errors.New("The Tailscale SSH server is disabled on macOS tailscaled by default. To try, set env TAILSCALE_USE_WIP_CODE=1")
}
default:
return errors.New("The Tailscale SSH server is not supported on " + runtime.GOOS)
}
if !envknob.CanSSHD() {
return errors.New("The Tailscale SSH server has been administratively disabled.")
}
if envknob.SSHIgnoreTailnetPolicy() || envknob.SSHPolicyFile() != "" {
return nil
}
if b.netMap != nil {
if !hasCapability(b.netMap, tailcfg.CapabilitySSH) {
if b.isDefaultServerLocked() {
return errors.New("Unable to enable local Tailscale SSH server; not enabled on Tailnet. See https://tailscale.com/s/ssh")
}
return errors.New("Unable to enable local Tailscale SSH server; not enabled on Tailnet.")
}
}
return nil
}
func (b *LocalBackend) sshOnButUnusableHealthCheckMessageLocked() (healthMessage string) {
if b.prefs == nil || !b.prefs.RunSSH {
return ""
}
if envknob.SSHIgnoreTailnetPolicy() || envknob.SSHPolicyFile() != "" {
return "development SSH policy in use"
}
nm := b.netMap
if nm == nil {
return ""
}
if nm.SSHPolicy != nil && len(nm.SSHPolicy.Rules) > 0 {
return ""
}
isDefault := b.isDefaultServerLocked()
isAdmin := hasCapability(nm, tailcfg.CapabilityAdmin)
if !isAdmin {
return "Tailscale SSH enabled, but access controls don't allow anyone to access this device. Ask your admin to update your tailnet's ACLs to allow access."
}
if !isDefault {
return "Tailscale SSH enabled, but access controls don't allow anyone to access this device. Update your tailnet's ACLs to allow access."
}
return "Tailscale SSH enabled, but access controls don't allow anyone to access this device. Update your tailnet's ACLs at https://tailscale.com/s/ssh-policy"
}
func (b *LocalBackend) isDefaultServerLocked() bool {
if b.prefs == nil {
return true // assume true until set otherwise
}
return b.prefs.ControlURLOrDefault() == ipn.DefaultControlURL
}
func (b *LocalBackend) EditPrefs(mp *ipn.MaskedPrefs) (*ipn.Prefs, error) {
b.mu.Lock()
if mp.EggSet {
mp.EggSet = false
b.egg = true
go b.doSetHostinfoFilterServices(b.hostinfo.Clone())
}
p0 := b.prefs.Clone()
p1 := b.prefs.Clone()
p1.ApplyEdits(mp)
if err := b.checkPrefsLocked(p1); err != nil {
b.mu.Unlock()
b.logf("EditPrefs check error: %v", err)
return nil, err
}
if p1.RunSSH && !envknob.CanSSHD() {
b.mu.Unlock()
b.logf("EditPrefs requests SSH, but disabled by envknob; returning error")
return nil, errors.New("Tailscale SSH server administratively disabled.")
}
if p1.Equals(p0) {
b.mu.Unlock()
return p1, nil
}
b.logf("EditPrefs: %v", mp.Pretty())
b.setPrefsLockedOnEntry("EditPrefs", p1) // does a b.mu.Unlock
// Note: don't perform any actions for the new prefs here. Not
// every prefs change goes through EditPrefs. Put your actions
// in setPrefsLocksOnEntry instead.
return p1, nil
}
// SetPrefs saves new user preferences and propagates them throughout
// the system. Implements Backend.
func (b *LocalBackend) SetPrefs(newp *ipn.Prefs) {
if newp == nil {
panic("SetPrefs got nil prefs")
}
b.mu.Lock()
b.setPrefsLockedOnEntry("SetPrefs", newp)
}
// setPrefsLockedOnEntry requires b.mu be held to call it, but it
// unlocks b.mu when done. newp ownership passes to this function.
func (b *LocalBackend) setPrefsLockedOnEntry(caller string, newp *ipn.Prefs) {
netMap := b.netMap
stateKey := b.stateKey
b.setAtomicValuesFromPrefs(newp)
oldp := b.prefs
newp.Persist = oldp.Persist // caller isn't allowed to override this
b.prefs = newp
// findExitNodeIDLocked returns whether it updated b.prefs, but
// everything in this function treats b.prefs as completely new
// anyway. No-op if no exit node resolution is needed.
b.findExitNodeIDLocked(netMap)
b.inServerMode = newp.ForceDaemon
// We do this to avoid holding the lock while doing everything else.
newp = b.prefs.Clone()
oldHi := b.hostinfo
newHi := oldHi.Clone()
b.applyPrefsToHostinfo(newHi, newp)
b.hostinfo = newHi
hostInfoChanged := !oldHi.Equal(newHi)
userID := b.userID
cc := b.cc
// [GRINDER STATS LINE] - please don't remove (used for log parsing)
if caller == "SetPrefs" {
b.logf("SetPrefs: %v", newp.Pretty())
}
b.updateFilterLocked(netMap, newp)
if oldp.ShouldSSHBeRunning() && !newp.ShouldSSHBeRunning() {
if b.sshServer != nil {
go b.sshServer.Shutdown()
b.sshServer = nil
}
}
b.mu.Unlock()
if stateKey != "" {
if err := b.store.WriteState(stateKey, newp.ToBytes()); err != nil {
b.logf("failed to save new controlclient state: %v", err)
}
}
b.writeServerModeStartState(userID, newp)
if netMap != nil {
if login := netMap.UserProfiles[netMap.User].LoginName; login != "" {
if newp.Persist == nil {
b.logf("active login: %s", login)
} else if newp.Persist.LoginName != login {
// Corp issue 461: sometimes the wrong prefs are
// logged; the frontend isn't always getting
// notified (to update its prefs/persist) on
// account switch. Log this while we figure it
// out.
b.logf("active login: %q ([unexpected] corp#461, not %q)", newp.Persist.LoginName, login)
}
}
}
if oldp.ShieldsUp != newp.ShieldsUp || hostInfoChanged {
b.doSetHostinfoFilterServices(newHi)
}
if netMap != nil {
b.e.SetDERPMap(netMap.DERPMap)
}
if !oldp.WantRunning && newp.WantRunning {
b.logf("transitioning to running; doing Login...")
cc.Login(nil, controlclient.LoginDefault)
}
if oldp.WantRunning != newp.WantRunning {
b.stateMachine()
} else {
b.authReconfig()
}
b.send(ipn.Notify{Prefs: newp})
}
// GetPeerAPIPort returns the port number for the peerapi server
// running on the provided IP.
func (b *LocalBackend) GetPeerAPIPort(ip netip.Addr) (port uint16, ok bool) {
b.mu.Lock()
defer b.mu.Unlock()
for _, pln := range b.peerAPIListeners {
if pln.ip == ip {
return uint16(pln.port), true
}
}
return 0, false
}
// ServePeerAPIConnection serves an already-accepted connection c.
//
// The remote parameter is the remote address.
// The local parameter is the local address (either a Tailscale IPv4
// or IPv6 IP and the peerapi port for that address).
//
// The connection will be closed by ServePeerAPIConnection.
func (b *LocalBackend) ServePeerAPIConnection(remote, local netip.AddrPort, c net.Conn) {
b.mu.Lock()
defer b.mu.Unlock()
for _, pln := range b.peerAPIListeners {
if pln.ip == local.Addr() {
go pln.ServeConn(remote, c)
return
}
}
b.logf("[unexpected] no peerAPI listener found for %v", local)
c.Close()
return
}
func (b *LocalBackend) peerAPIServicesLocked() (ret []tailcfg.Service) {
for _, pln := range b.peerAPIListeners {
proto := tailcfg.PeerAPI4
if pln.ip.Is6() {
proto = tailcfg.PeerAPI6
}
ret = append(ret, tailcfg.Service{
Proto: proto,
Port: uint16(pln.port),
})
}
switch runtime.GOOS {
case "linux", "freebsd", "openbsd", "illumos", "darwin", "windows":
// These are the platforms currently supported by
// net/dns/resolver/tsdns.go:Resolver.HandleExitNodeDNSQuery.
ret = append(ret, tailcfg.Service{
Proto: tailcfg.PeerAPIDNS,
Port: 1, // version
})
}
return ret
}
// doSetHostinfoFilterServices calls SetHostinfo on the controlclient,
// possibly after mangling the given hostinfo.
//
// TODO(danderson): we shouldn't be mangling hostinfo here after
// painstakingly constructing it in twelvety other places.
func (b *LocalBackend) doSetHostinfoFilterServices(hi *tailcfg.Hostinfo) {
if hi == nil {
b.logf("[unexpected] doSetHostinfoFilterServices with nil hostinfo")
return
}
b.mu.Lock()
cc := b.cc
if cc == nil {
// Control client isn't up yet.
b.mu.Unlock()
return
}
peerAPIServices := b.peerAPIServicesLocked()
if b.egg {
peerAPIServices = append(peerAPIServices, tailcfg.Service{Proto: "egg"})
}
b.mu.Unlock()
// Make a shallow copy of hostinfo so we can mutate
// at the Service field.
hi2 := *hi // shallow copy
if !b.shouldUploadServices() {
hi2.Services = []tailcfg.Service{}
}
// Don't mutate hi.Service's underlying array. Append to
// the slice with no free capacity.
c := len(hi2.Services)
hi2.Services = append(hi2.Services[:c:c], peerAPIServices...)
cc.SetHostinfo(&hi2)
}
// NetMap returns the latest cached network map received from
// controlclient, or nil if no network map was received yet.
func (b *LocalBackend) NetMap() *netmap.NetworkMap {
b.mu.Lock()
defer b.mu.Unlock()
return b.netMap
}
func (b *LocalBackend) isEngineBlocked() bool {
b.mu.Lock()
defer b.mu.Unlock()
return b.blocked
}
// blockEngineUpdate sets b.blocked to block, while holding b.mu. Its
// indirect effect is to turn b.authReconfig() into a no-op if block
// is true.
func (b *LocalBackend) blockEngineUpdates(block bool) {
b.logf("blockEngineUpdates(%v)", block)
b.mu.Lock()
b.blocked = block
b.mu.Unlock()
}
// authReconfig pushes a new configuration into wgengine, if engine
// updates are not currently blocked, based on the cached netmap and
// user prefs.
func (b *LocalBackend) authReconfig() {
b.mu.Lock()
blocked := b.blocked
prefs := b.prefs
nm := b.netMap
hasPAC := b.prevIfState.HasPAC()
disableSubnetsIfPAC := nm != nil && nm.Debug != nil && nm.Debug.DisableSubnetsIfPAC.EqualBool(true)
b.mu.Unlock()
if blocked {
b.logf("[v1] authReconfig: blocked, skipping.")
return
}
if nm == nil {
b.logf("[v1] authReconfig: netmap not yet valid. Skipping.")
return
}
if !prefs.WantRunning {
b.logf("[v1] authReconfig: skipping because !WantRunning.")
return
}
var flags netmap.WGConfigFlags
if prefs.RouteAll {
flags |= netmap.AllowSubnetRoutes
}
if prefs.AllowSingleHosts {
flags |= netmap.AllowSingleHosts
}
if hasPAC && disableSubnetsIfPAC {
if flags&netmap.AllowSubnetRoutes != 0 {
b.logf("authReconfig: have PAC; disabling subnet routes")
flags &^= netmap.AllowSubnetRoutes
}
}
// Keep the dialer updated about whether we're supposed to use
// an exit node's DNS server (so SOCKS5/HTTP outgoing dials
// can use it for name resolution)
if dohURL, ok := exitNodeCanProxyDNS(nm, prefs.ExitNodeID); ok {
b.dialer.SetExitDNSDoH(dohURL)
} else {
b.dialer.SetExitDNSDoH("")
}
cfg, err := nmcfg.WGCfg(nm, b.logf, flags, prefs.ExitNodeID)
if err != nil {
b.logf("wgcfg: %v", err)
return
}
oneCGNATRoute := shouldUseOneCGNATRoute(nm, b.logf, version.OS())
rcfg := b.routerConfig(cfg, prefs, oneCGNATRoute)
dcfg := dnsConfigForNetmap(nm, prefs, b.logf, version.OS())
err = b.e.Reconfig(cfg, rcfg, dcfg, nm.Debug)
if err == wgengine.ErrNoChanges {
return
}
b.logf("[v1] authReconfig: ra=%v dns=%v 0x%02x: %v", prefs.RouteAll, prefs.CorpDNS, flags, err)
b.initPeerAPIListener()
}
// shouldUseOneCGNATRoute reports whether we should prefer to make one big
// CGNAT /10 route rather than a /32 per peer.
//
// The versionOS is a Tailscale-style version ("iOS", "macOS") and not
// a runtime.GOOS.
func shouldUseOneCGNATRoute(nm *netmap.NetworkMap, logf logger.Logf, versionOS string) bool {
// Explicit enabling or disabling always take precedence.
if nm.Debug != nil {
if v, ok := nm.Debug.OneCGNATRoute.Get(); ok {
logf("[v1] shouldUseOneCGNATRoute: explicit=%v", v)
return v
}
}
// Also prefer to do this on the Mac, so that we don't need to constantly
// update the network extension configuration (which is disruptive to
// Chrome, see https://github.com/tailscale/tailscale/issues/3102). Only
// use fine-grained routes if another interfaces is also using the CGNAT
// IP range.
if versionOS == "macOS" {
hasCGNATInterface, err := interfaces.HasCGNATInterface()
if err != nil {
logf("shouldUseOneCGNATRoute: Could not determine if any interfaces use CGNAT: %v", err)
return false
}
logf("[v1] shouldUseOneCGNATRoute: macOS automatic=%v", !hasCGNATInterface)
if !hasCGNATInterface {
return true
}
}
return false
}
// dnsConfigForNetmap returns a *dns.Config for the given netmap,
// prefs, client OS version, and cloud hosting environment.
//
// The versionOS is a Tailscale-style version ("iOS", "macOS") and not
// a runtime.GOOS.
func dnsConfigForNetmap(nm *netmap.NetworkMap, prefs *ipn.Prefs, logf logger.Logf, versionOS string) *dns.Config {
dcfg := &dns.Config{
Routes: map[dnsname.FQDN][]*dnstype.Resolver{},
Hosts: map[dnsname.FQDN][]netip.Addr{},
}
// selfV6Only is whether we only have IPv6 addresses ourselves.
selfV6Only := tsaddr.PrefixesContainsFunc(nm.Addresses, tsaddr.PrefixIs6) &&
!tsaddr.PrefixesContainsFunc(nm.Addresses, tsaddr.PrefixIs4)
dcfg.OnlyIPv6 = selfV6Only
// Populate MagicDNS records. We do this unconditionally so that
// quad-100 can always respond to MagicDNS queries, even if the OS
// isn't configured to make MagicDNS resolution truly
// magic. Details in
// https://github.com/tailscale/tailscale/issues/1886.
set := func(name string, addrs []netip.Prefix) {
if len(addrs) == 0 || name == "" {
return
}
fqdn, err := dnsname.ToFQDN(name)
if err != nil {
return // TODO: propagate error?
}
have4 := tsaddr.PrefixesContainsFunc(addrs, tsaddr.PrefixIs4)
var ips []netip.Addr
for _, addr := range addrs {
if selfV6Only {
if addr.Addr().Is6() {
ips = append(ips, addr.Addr())
}
continue
}
// If this node has an IPv4 address, then
// remove peers' IPv6 addresses for now, as we
// don't guarantee that the peer node actually
// can speak IPv6 correctly.
//
// https://github.com/tailscale/tailscale/issues/1152
// tracks adding the right capability reporting to
// enable AAAA in MagicDNS.
if addr.Addr().Is6() && have4 {
continue
}
ips = append(ips, addr.Addr())
}
dcfg.Hosts[fqdn] = ips
}
set(nm.Name, nm.Addresses)
for _, peer := range nm.Peers {
set(peer.Name, peer.Addresses)
}
for _, rec := range nm.DNS.ExtraRecords {
switch rec.Type {
case "", "A", "AAAA":
// Treat these all the same for now: infer from the value
default:
// TODO: more
continue
}
ip, err := netip.ParseAddr(rec.Value)
if err != nil {
// Ignore.
continue
}
fqdn, err := dnsname.ToFQDN(rec.Name)
if err != nil {
continue
}
dcfg.Hosts[fqdn] = append(dcfg.Hosts[fqdn], ip)
}
if !prefs.CorpDNS {
return dcfg
}
for _, dom := range nm.DNS.Domains {
fqdn, err := dnsname.ToFQDN(dom)
if err != nil {
logf("[unexpected] non-FQDN search domain %q", dom)
}
dcfg.SearchDomains = append(dcfg.SearchDomains, fqdn)
}
if nm.DNS.Proxied { // actually means "enable MagicDNS"
for _, dom := range magicDNSRootDomains(nm) {
dcfg.Routes[dom] = nil // resolve internally with dcfg.Hosts
}
}
addDefault := func(resolvers []*dnstype.Resolver) {
for _, r := range resolvers {
dcfg.DefaultResolvers = append(dcfg.DefaultResolvers, r)
}
}
// If we're using an exit node and that exit node is new enough (1.19.x+)
// to run a DoH DNS proxy, then send all our DNS traffic through it.
if dohURL, ok := exitNodeCanProxyDNS(nm, prefs.ExitNodeID); ok {
addDefault([]*dnstype.Resolver{{Addr: dohURL}})
return dcfg
}
addDefault(nm.DNS.Resolvers)
for suffix, resolvers := range nm.DNS.Routes {
fqdn, err := dnsname.ToFQDN(suffix)
if err != nil {
logf("[unexpected] non-FQDN route suffix %q", suffix)
}
// Create map entry even if len(resolvers) == 0; Issue 2706.
// This lets the control plane send ExtraRecords for which we
// can authoritatively answer "name not exists" for when the
// control plane also sends this explicit but empty route
// making it as something we handle.
//
// While we're already populating it, might as well size the
// slice appropriately.
dcfg.Routes[fqdn] = make([]*dnstype.Resolver, 0, len(resolvers))
for _, r := range resolvers {
dcfg.Routes[fqdn] = append(dcfg.Routes[fqdn], r)
}
}
// Set FallbackResolvers as the default resolvers in the
// scenarios that can't handle a purely split-DNS config. See
// https://github.com/tailscale/tailscale/issues/1743 for
// details.
switch {
case len(dcfg.DefaultResolvers) != 0:
// Default resolvers already set.
case !prefs.ExitNodeID.IsZero():
// When using exit nodes, it's very likely the LAN
// resolvers will become unreachable. So, force use of the
// fallback resolvers until we implement DNS forwarding to
// exit nodes.
//
// This is especially important on Apple OSes, where
// adding the default route to the tunnel interface makes
// it "primary", and we MUST provide VPN-sourced DNS
// settings or we break all DNS resolution.
//
// https://github.com/tailscale/tailscale/issues/1713
addDefault(nm.DNS.FallbackResolvers)
case len(dcfg.Routes) == 0:
// No settings requiring split DNS, no problem.
}
return dcfg
}
// SetTailnetKeyAuthority sets the key authority which should be
// used for locked tailnets.
//
// It should only be called before the LocalBackend is used.
func (b *LocalBackend) SetTailnetKeyAuthority(a *tka.Authority, storage *tka.FS) {
b.tka = &tkaState{
authority: a,
storage: storage,
}
}
// SetVarRoot sets the root directory of Tailscale's writable
// storage area . (e.g. "/var/lib/tailscale")
//
// It should only be called before the LocalBackend is used.
func (b *LocalBackend) SetVarRoot(dir string) {
b.varRoot = dir
}
// TailscaleVarRoot returns the root directory of Tailscale's writable
// storage area. (e.g. "/var/lib/tailscale")
//
// It returns an empty string if there's no configured or discovered
// location.
func (b *LocalBackend) TailscaleVarRoot() string {
if b.varRoot != "" {
return b.varRoot
}
switch runtime.GOOS {
case "ios", "android", "darwin":
return paths.AppSharedDir.Load()
}
return ""
}
func (b *LocalBackend) fileRootLocked(uid tailcfg.UserID) string {
if v := b.directFileRoot; v != "" {
return v
}
varRoot := b.TailscaleVarRoot()
if varRoot == "" {
b.logf("Taildrop disabled; no state directory")
return ""
}
baseDir := fmt.Sprintf("%s-uid-%d",
strings.ReplaceAll(b.activeLogin, "@", "-"),
uid)
dir := filepath.Join(varRoot, "files", baseDir)
if err := os.MkdirAll(dir, 0700); err != nil {
b.logf("Taildrop disabled; error making directory: %v", err)
return ""
}
return dir
}
// closePeerAPIListenersLocked closes any existing peer API listeners
// and clears out the peer API server state.
//
// It does not kick off any Hostinfo update with new services.
//
// b.mu must be held.
func (b *LocalBackend) closePeerAPIListenersLocked() {
b.peerAPIServer = nil
for _, pln := range b.peerAPIListeners {
pln.Close()
}
b.peerAPIListeners = nil
}
// peerAPIListenAsync is whether the operating system requires that we
// retry listening on the peerAPI ip/port for whatever reason.
//
// On Windows, see Issue 1620.
// On Android, see Issue 1960.
const peerAPIListenAsync = runtime.GOOS == "windows" || runtime.GOOS == "android"
func (b *LocalBackend) initPeerAPIListener() {
b.mu.Lock()
defer b.mu.Unlock()
if b.shutdownCalled {
return
}
if b.netMap == nil {
// We're called from authReconfig which checks that
// netMap is non-nil, but if a concurrent Logout,
// ResetForClientDisconnect, or Start happens when its
// mutex was released, the netMap could be
// nil'ed out (Issue 1996). Bail out early here if so.
return
}
if len(b.netMap.Addresses) == len(b.peerAPIListeners) {
allSame := true
for i, pln := range b.peerAPIListeners {
if pln.ip != b.netMap.Addresses[i].Addr() {
allSame = false
break
}
}
if allSame {
// Nothing to do.
return
}
}
b.closePeerAPIListenersLocked()
selfNode := b.netMap.SelfNode
if len(b.netMap.Addresses) == 0 || selfNode == nil {
return
}
fileRoot := b.fileRootLocked(selfNode.User)
if fileRoot == "" {
b.logf("peerapi starting without Taildrop directory configured")
}
ps := &peerAPIServer{
b: b,
rootDir: fileRoot,
selfNode: selfNode,
directFileMode: b.directFileRoot != "",
directFileDoFinalRename: b.directFileDoFinalRename,
}
if re, ok := b.e.(wgengine.ResolvingEngine); ok {
if r, ok := re.GetResolver(); ok {
ps.resolver = r
}
}
b.peerAPIServer = ps
isNetstack := wgengine.IsNetstack(b.e)
for i, a := range b.netMap.Addresses {
var ln net.Listener
var err error
skipListen := i > 0 && isNetstack
if !skipListen {
ln, err = ps.listen(a.Addr(), b.prevIfState)
if err != nil {
if peerAPIListenAsync {
// Expected. But we fix it later in linkChange
// ("peerAPIListeners too low").
continue
}
b.logf("[unexpected] peerapi listen(%q) error: %v", a.Addr(), err)
continue
}
}
pln := &peerAPIListener{
ps: ps,
ip: a.Addr(),
ln: ln, // nil for 2nd+ on netstack
lb: b,
}
if skipListen {
pln.port = b.peerAPIListeners[0].port
} else {
pln.port = ln.Addr().(*net.TCPAddr).Port
}
pln.urlStr = "http://" + net.JoinHostPort(a.Addr().String(), strconv.Itoa(pln.port))
b.logf("peerapi: serving on %s", pln.urlStr)
go pln.serve()
b.peerAPIListeners = append(b.peerAPIListeners, pln)
}
go b.doSetHostinfoFilterServices(b.hostinfo.Clone())
}
// magicDNSRootDomains returns the subset of nm.DNS.Domains that are the search domains for MagicDNS.
func magicDNSRootDomains(nm *netmap.NetworkMap) []dnsname.FQDN {
if v := nm.MagicDNSSuffix(); v != "" {
fqdn, err := dnsname.ToFQDN(v)
if err != nil {
// TODO: propagate error
return nil
}
ret := []dnsname.FQDN{
fqdn,
dnsname.FQDN("0.e.1.a.c.5.1.1.a.7.d.f.ip6.arpa."),
}
for i := 64; i <= 127; i++ {
fqdn, err = dnsname.ToFQDN(fmt.Sprintf("%d.100.in-addr.arpa.", i))
if err != nil {
// TODO: propagate error
continue
}
ret = append(ret, fqdn)
}
return ret
}
return nil
}
var (
ipv4Default = netip.MustParsePrefix("0.0.0.0/0")
ipv6Default = netip.MustParsePrefix("::/0")
)
// peerRoutes returns the routerConfig.Routes to access peers.
// If there are over cgnatThreshold CGNAT routes, one big CGNAT route
// is used instead.
func peerRoutes(peers []wgcfg.Peer, cgnatThreshold int) (routes []netip.Prefix) {
tsULA := tsaddr.TailscaleULARange()
cgNAT := tsaddr.CGNATRange()
var didULA bool
var cgNATIPs []netip.Prefix
for _, peer := range peers {
for _, aip := range peer.AllowedIPs {
aip = unmapIPPrefix(aip)
// Only add the Tailscale IPv6 ULA once, if we see anybody using part of it.
if aip.Addr().Is6() && aip.IsSingleIP() && tsULA.Contains(aip.Addr()) {
if !didULA {
didULA = true
routes = append(routes, tsULA)
}
continue
}
if aip.IsSingleIP() && cgNAT.Contains(aip.Addr()) {
cgNATIPs = append(cgNATIPs, aip)
} else {
routes = append(routes, aip)
}
}
}
if len(cgNATIPs) > cgnatThreshold {
// Probably the hello server. Just append one big route.
routes = append(routes, cgNAT)
} else {
routes = append(routes, cgNATIPs...)
}
sort.Slice(routes, func(i, j int) bool {
return ipPrefixLess(routes[i], routes[j])
})
return routes
}
func ipPrefixLess(ri, rj netip.Prefix) bool {
if ri.Addr() == rj.Addr() {
return ri.Bits() < rj.Bits()
}
return ri.Addr().Less(rj.Addr())
}
// routerConfig produces a router.Config from a wireguard config and IPN prefs.
func (b *LocalBackend) routerConfig(cfg *wgcfg.Config, prefs *ipn.Prefs, oneCGNATRoute bool) *router.Config {
singleRouteThreshold := 10_000
if oneCGNATRoute {
singleRouteThreshold = 1
}
rs := &router.Config{
LocalAddrs: unmapIPPrefixes(cfg.Addresses),
SubnetRoutes: unmapIPPrefixes(prefs.AdvertiseRoutes),
SNATSubnetRoutes: !prefs.NoSNAT,
NetfilterMode: prefs.NetfilterMode,
Routes: peerRoutes(cfg.Peers, singleRouteThreshold),
}
if distro.Get() == distro.Synology {
// Issue 1995: we don't use iptables on Synology.
rs.NetfilterMode = preftype.NetfilterOff
}
// Sanity check: we expect the control server to program both a v4
// and a v6 default route, if default routing is on. Fill in
// blackhole routes appropriately if we're missing some. This is
// likely to break some functionality, but if the user expressed a
// preference for routing remotely, we want to avoid leaking
// traffic at the expense of functionality.
if prefs.ExitNodeID != "" || prefs.ExitNodeIP.IsValid() {
var default4, default6 bool
for _, route := range rs.Routes {
switch route {
case ipv4Default:
default4 = true
case ipv6Default:
default6 = true
}
if default4 && default6 {
break
}
}
if !default4 {
rs.Routes = append(rs.Routes, ipv4Default)
}
if !default6 {
rs.Routes = append(rs.Routes, ipv6Default)
}
internalIPs, externalIPs, err := internalAndExternalInterfaces()
if err != nil {
b.logf("failed to discover interface ips: %v", err)
}
if runtime.GOOS == "linux" || runtime.GOOS == "darwin" || runtime.GOOS == "windows" {
rs.LocalRoutes = internalIPs // unconditionally allow access to guest VM networks
if prefs.ExitNodeAllowLANAccess {
rs.LocalRoutes = append(rs.LocalRoutes, externalIPs...)
} else {
// Explicitly add routes to the local network so that we do not
// leak any traffic.
rs.Routes = append(rs.Routes, externalIPs...)
}
b.logf("allowing exit node access to local IPs: %v", rs.LocalRoutes)
}
}
if tsaddr.PrefixesContainsFunc(rs.LocalAddrs, tsaddr.PrefixIs4) {
rs.Routes = append(rs.Routes, netip.PrefixFrom(tsaddr.TailscaleServiceIP(), 32))
}
return rs
}
func unmapIPPrefix(ipp netip.Prefix) netip.Prefix {
return netip.PrefixFrom(ipp.Addr().Unmap(), ipp.Bits())
}
func unmapIPPrefixes(ippsList ...[]netip.Prefix) (ret []netip.Prefix) {
for _, ipps := range ippsList {
for _, ipp := range ipps {
ret = append(ret, unmapIPPrefix(ipp))
}
}
return ret
}
// Warning: b.mu might be held. Currently (2022-02-17) both callers hold it.
func (b *LocalBackend) applyPrefsToHostinfo(hi *tailcfg.Hostinfo, prefs *ipn.Prefs) {
if h := prefs.Hostname; h != "" {
hi.Hostname = h
}
hi.RoutableIPs = append(prefs.AdvertiseRoutes[:0:0], prefs.AdvertiseRoutes...)
hi.RequestTags = append(prefs.AdvertiseTags[:0:0], prefs.AdvertiseTags...)
hi.ShieldsUp = prefs.ShieldsUp
var sshHostKeys []string
if prefs.RunSSH && envknob.CanSSHD() {
// TODO(bradfitz): this is called with b.mu held. Not ideal.
// If the filesystem gets wedged or something we could block for
// a long time. But probably fine.
sshHostKeys = b.getSSHHostKeyPublicStrings()
}
hi.SSH_HostKeys = sshHostKeys
}
// enterState transitions the backend into newState, updating internal
// state and propagating events out as needed.
//
// TODO(danderson): while this isn't a lie, exactly, a ton of other
// places twiddle IPN internal state without going through here, so
// really this is more "one of several places in which random things
// happen".
func (b *LocalBackend) enterState(newState ipn.State) {
b.mu.Lock()
oldState := b.state
b.state = newState
prefs := b.prefs
netMap := b.netMap
activeLogin := b.activeLogin
authURL := b.authURL
if newState == ipn.Running {
b.authURL = ""
b.authURLSticky = ""
} else if oldState == ipn.Running {
// Transitioning away from running.
b.closePeerAPIListenersLocked()
}
b.maybePauseControlClientLocked()
b.mu.Unlock()
// prefs may change irrespective of state; WantRunning should be explicitly
// set before potential early return even if the state is unchanged.
health.SetIPNState(newState.String(), prefs.WantRunning)
if oldState == newState {
return
}
b.logf("Switching ipn state %v -> %v (WantRunning=%v, nm=%v)",
oldState, newState, prefs.WantRunning, netMap != nil)
b.send(ipn.Notify{State: &newState})
switch newState {
case ipn.NeedsLogin:
systemd.Status("Needs login: %s", authURL)
b.blockEngineUpdates(true)
fallthrough
case ipn.Stopped:
err := b.e.Reconfig(&wgcfg.Config{}, &router.Config{}, &dns.Config{}, nil)
if err != nil {
b.logf("Reconfig(down): %v", err)
}
if authURL == "" {
systemd.Status("Stopped; run 'tailscale up' to log in")
}
case ipn.Starting, ipn.NeedsMachineAuth:
b.authReconfig()
// Needed so that UpdateEndpoints can run
b.e.RequestStatus()
case ipn.Running:
var addrs []string
for _, addr := range netMap.Addresses {
addrs = append(addrs, addr.Addr().String())
}
systemd.Status("Connected; %s; %s", activeLogin, strings.Join(addrs, " "))
default:
b.logf("[unexpected] unknown newState %#v", newState)
}
}
func (b *LocalBackend) hasNodeKey() bool {
// we can't use b.Prefs(), because it strips the keys, oops!
b.mu.Lock()
p := b.prefs
b.mu.Unlock()
return p.Persist != nil && !p.Persist.PrivateNodeKey.IsZero()
}
// nextState returns the state the backend seems to be in, based on
// its internal state.
func (b *LocalBackend) nextState() ipn.State {
b.mu.Lock()
b.assertClientLocked()
var (
cc = b.cc
netMap = b.netMap
state = b.state
blocked = b.blocked
wantRunning = b.prefs.WantRunning
loggedOut = b.prefs.LoggedOut
st = b.engineStatus
keyExpired = b.keyExpired
)
b.mu.Unlock()
switch {
case !wantRunning && !loggedOut && !blocked && b.hasNodeKey():
return ipn.Stopped
case netMap == nil:
if cc.AuthCantContinue() || loggedOut {
// Auth was interrupted or waiting for URL visit,
// so it won't proceed without human help.
return ipn.NeedsLogin
}
switch state {
case ipn.Stopped:
// If we were already in the Stopped state, then
// we can assume auth is in good shape (or we would
// have been in NeedsLogin), so transition to Starting
// right away.
return ipn.Starting
case ipn.NoState:
// Our first time connecting to control, and we
// don't know if we'll NeedsLogin or not yet.
// UIs should print "Loading..." in this state.
return ipn.NoState
case ipn.Starting, ipn.Running, ipn.NeedsLogin:
return state
default:
b.logf("unexpected no-netmap state transition for %v", state)
return state
}
case !wantRunning:
return ipn.Stopped
case keyExpired:
// NetMap must be non-nil for us to get here.
// The node key expired, need to relogin.
return ipn.NeedsLogin
case netMap.MachineStatus != tailcfg.MachineAuthorized:
// TODO(crawshaw): handle tailcfg.MachineInvalid
return ipn.NeedsMachineAuth
case state == ipn.NeedsMachineAuth:
// (if we get here, we know MachineAuthorized == true)
return ipn.Starting
case state == ipn.Starting:
if st.NumLive > 0 || st.LiveDERPs > 0 {
return ipn.Running
} else {
return state
}
case state == ipn.Running:
return ipn.Running
default:
return ipn.Starting
}
}
// RequestEngineStatus implements Backend.
func (b *LocalBackend) RequestEngineStatus() {
b.e.RequestStatus()
}
// stateMachine updates the state machine state based on other things
// that have happened. It is invoked from the various callbacks that
// feed events into LocalBackend.
//
// TODO(apenwarr): use a channel or something to prevent reentrancy?
// Or maybe just call the state machine from fewer places.
func (b *LocalBackend) stateMachine() {
b.enterState(b.nextState())
}
// stopEngineAndWait deconfigures the local network data plane, and
// waits for it to deliver a status update before returning.
//
// TODO(danderson): this may be racy. We could unblock upon receiving
// a status update that predates the "I've shut down" update.
func (b *LocalBackend) stopEngineAndWait() {
b.logf("stopEngineAndWait...")
b.e.Reconfig(&wgcfg.Config{}, &router.Config{}, &dns.Config{}, nil)
b.requestEngineStatusAndWait()
b.logf("stopEngineAndWait: done.")
}
// Requests the wgengine status, and does not return until the status
// was delivered (to the usual callback).
func (b *LocalBackend) requestEngineStatusAndWait() {
b.logf("requestEngineStatusAndWait")
b.statusLock.Lock()
go b.e.RequestStatus()
b.logf("requestEngineStatusAndWait: waiting...")
b.statusChanged.Wait() // temporarily releases lock while waiting
b.logf("requestEngineStatusAndWait: got status update.")
b.statusLock.Unlock()
}
// ResetForClientDisconnect resets the backend for GUI clients running
// in interactive (non-headless) mode. This is currently used only by
// Windows. This causes all state to be cleared, lest an unrelated user
// connect to tailscaled next. But it does not trigger a logout; we
// don't want to the user to have to reauthenticate in the future
// when they restart the GUI.
func (b *LocalBackend) ResetForClientDisconnect() {
defer b.enterState(ipn.Stopped)
b.mu.Lock()
defer b.mu.Unlock()
b.logf("LocalBackend.ResetForClientDisconnect")
if b.cc != nil {
go b.cc.Shutdown()
b.cc = nil
}
b.stateKey = ""
b.userID = ""
b.setNetMapLocked(nil)
b.prefs = new(ipn.Prefs)
b.keyExpired = false
b.authURL = ""
b.authURLSticky = ""
b.activeLogin = ""
b.setAtomicValuesFromPrefs(nil)
}
func (b *LocalBackend) ShouldRunSSH() bool { return b.sshAtomicBool.Load() && envknob.CanSSHD() }
// ShouldHandleViaIP reports whether ip is an IPv6 address in the
// Tailscale ULA's v6 "via" range embedding an IPv4 address to be forwarded to
// by Tailscale.
func (b *LocalBackend) ShouldHandleViaIP(ip netip.Addr) bool {
if f, ok := b.containsViaIPFuncAtomic.LoadOk(); ok {
return f(ip)
}
return false
}
// Logout tells the controlclient that we want to log out, and
// transitions the local engine to the logged-out state without
// waiting for controlclient to be in that state.
func (b *LocalBackend) Logout() {
b.logout(context.Background(), false)
}
func (b *LocalBackend) LogoutSync(ctx context.Context) error {
return b.logout(ctx, true)
}
func (b *LocalBackend) logout(ctx context.Context, sync bool) error {
b.mu.Lock()
cc := b.cc
b.mu.Unlock()
b.EditPrefs(&ipn.MaskedPrefs{
WantRunningSet: true,
LoggedOutSet: true,
Prefs: ipn.Prefs{WantRunning: false, LoggedOut: true},
})
// Clear any previous dial plan(s), if set.
b.dialPlan.Store(nil)
if cc == nil {
// Double Logout can happen via repeated IPN
// connections to ipnserver making it repeatedly
// transition from 1->0 total connections, which on
// Windows by default ("client mode") causes a Logout
// on the transition to zero.
// Previously this crashed when we asserted that c was non-nil
// here.
return errors.New("no controlclient")
}
var err error
if sync {
err = cc.Logout(ctx)
} else {
cc.StartLogout()
}
b.stateMachine()
return err
}
// assertClientLocked crashes if there is no controlclient in this backend.
func (b *LocalBackend) assertClientLocked() {
if b.cc == nil {
panic("LocalBackend.assertClient: b.cc == nil")
}
}
// setNetInfo sets b.hostinfo.NetInfo to ni, and passes ni along to the
// controlclient, if one exists.
func (b *LocalBackend) setNetInfo(ni *tailcfg.NetInfo) {
b.mu.Lock()
cc := b.cc
b.mu.Unlock()
if cc == nil {
return
}
cc.SetNetInfo(ni)
}
func hasCapability(nm *netmap.NetworkMap, cap string) bool {
if nm != nil && nm.SelfNode != nil {
for _, c := range nm.SelfNode.Capabilities {
if c == cap {
return true
}
}
}
return false
}
func (b *LocalBackend) setNetMapLocked(nm *netmap.NetworkMap) {
b.dialer.SetNetMap(nm)
var login string
if nm != nil {
login = nm.UserProfiles[nm.User].LoginName
if login == "" {
login = "<missing-profile>"
}
}
b.netMap = nm
if login != b.activeLogin {
b.logf("active login: %v", login)
b.activeLogin = login
}
b.maybePauseControlClientLocked()
if nm != nil {
health.SetControlHealth(nm.ControlHealth)
} else {
health.SetControlHealth(nil)
}
// Determine if file sharing is enabled
fs := hasCapability(nm, tailcfg.CapabilityFileSharing)
if fs != b.capFileSharing {
osshare.SetFileSharingEnabled(fs, b.logf)
}
b.capFileSharing = fs
if nm == nil {
b.nodeByAddr = nil
return
}
// Update the nodeByAddr index.
if b.nodeByAddr == nil {
b.nodeByAddr = map[netip.Addr]*tailcfg.Node{}
}
// First pass, mark everything unwanted.
for k := range b.nodeByAddr {
b.nodeByAddr[k] = nil
}
addNode := func(n *tailcfg.Node) {
for _, ipp := range n.Addresses {
if ipp.IsSingleIP() {
b.nodeByAddr[ipp.Addr()] = n
}
}
}
if nm.SelfNode != nil {
addNode(nm.SelfNode)
}
for _, p := range nm.Peers {
addNode(p)
}
// Third pass, actually delete the unwanted items.
for k, v := range b.nodeByAddr {
if v == nil {
delete(b.nodeByAddr, k)
}
}
}
// operatorUserName returns the current pref's OperatorUser's name, or the
// empty string if none.
func (b *LocalBackend) operatorUserName() string {
b.mu.Lock()
defer b.mu.Unlock()
if b.prefs == nil {
return ""
}
return b.prefs.OperatorUser
}
// OperatorUserID returns the current pref's OperatorUser's ID (in
// os/user.User.Uid string form), or the empty string if none.
func (b *LocalBackend) OperatorUserID() string {
b.mu.Lock()
if b.prefs == nil {
b.mu.Unlock()
return ""
}
opUserName := b.prefs.OperatorUser
b.mu.Unlock()
if opUserName == "" {
return ""
}
u, err := user.Lookup(opUserName)
if err != nil {
b.logf("error looking up operator %q uid: %v", opUserName, err)
return ""
}
return u.Uid
}
// TestOnlyPublicKeys returns the current machine and node public
// keys. Used in tests only to facilitate automated node authorization
// in the test harness.
func (b *LocalBackend) TestOnlyPublicKeys() (machineKey key.MachinePublic, nodeKey key.NodePublic) {
b.mu.Lock()
prefs := b.prefs
machinePrivKey := b.machinePrivKey
b.mu.Unlock()
if prefs == nil || machinePrivKey.IsZero() {
return
}
mk := machinePrivKey.Public()
nk := prefs.Persist.PrivateNodeKey.Public()
return mk, nk
}
func (b *LocalBackend) WaitingFiles() ([]apitype.WaitingFile, error) {
b.mu.Lock()
apiSrv := b.peerAPIServer
b.mu.Unlock()
return apiSrv.WaitingFiles()
}
func (b *LocalBackend) DeleteFile(name string) error {
b.mu.Lock()
apiSrv := b.peerAPIServer
b.mu.Unlock()
return apiSrv.DeleteFile(name)
}
func (b *LocalBackend) OpenFile(name string) (rc io.ReadCloser, size int64, err error) {
b.mu.Lock()
apiSrv := b.peerAPIServer
b.mu.Unlock()
return apiSrv.OpenFile(name)
}
// hasCapFileSharing reports whether the current node has the file
// sharing capability enabled.
func (b *LocalBackend) hasCapFileSharing() bool {
b.mu.Lock()
defer b.mu.Unlock()
return b.capFileSharing
}
// FileTargets lists nodes that the current node can send files to.
func (b *LocalBackend) FileTargets() ([]*apitype.FileTarget, error) {
var ret []*apitype.FileTarget
b.mu.Lock()
defer b.mu.Unlock()
nm := b.netMap
if b.state != ipn.Running || nm == nil {
return nil, errors.New("not connected to the tailnet")
}
if !b.capFileSharing {
return nil, errors.New("file sharing not enabled by Tailscale admin")
}
for _, p := range nm.Peers {
if !b.peerIsTaildropTargetLocked(p) {
continue
}
peerAPI := peerAPIBase(b.netMap, p)
if peerAPI == "" {
continue
}
ret = append(ret, &apitype.FileTarget{
Node: p,
PeerAPIURL: peerAPI,
})
}
// TODO: sort a different way than the netmap already is?
return ret, nil
}
// peerIsTaildropTargetLocked reports whether p is a valid Taildrop file
// recipient from this node according to its ownership and the capabilities in
// the netmap.
//
// b.mu must be locked.
func (b *LocalBackend) peerIsTaildropTargetLocked(p *tailcfg.Node) bool {
if b.netMap == nil || p == nil {
return false
}
if b.netMap.User == p.User {
return true
}
if len(p.Addresses) > 0 &&
b.peerHasCapLocked(p.Addresses[0].Addr(), tailcfg.CapabilityFileSharingTarget) {
// Explicitly noted in the netmap ACL caps as a target.
return true
}
return false
}
func (b *LocalBackend) peerHasCapLocked(addr netip.Addr, wantCap string) bool {
for _, hasCap := range b.peerCapsLocked(addr) {
if hasCap == wantCap {
return true
}
}
return false
}
// SetDNS adds a DNS record for the given domain name & TXT record
// value.
//
// It's meant for use with dns-01 ACME (LetsEncrypt) challenges.
//
// This is the low-level interface. Other layers will provide more
// friendly options to get HTTPS certs.
func (b *LocalBackend) SetDNS(ctx context.Context, name, value string) error {
req := &tailcfg.SetDNSRequest{
Version: 1, // TODO(bradfitz,maisem): use tailcfg.CurrentCapabilityVersion when using the Noise transport
Type: "TXT",
Name: name,
Value: value,
}
b.mu.Lock()
cc := b.ccAuto
if prefs := b.prefs; prefs != nil {
req.NodeKey = prefs.Persist.PrivateNodeKey.Public()
}
b.mu.Unlock()
if cc == nil {
return errors.New("not connected")
}
if req.NodeKey.IsZero() {
return errors.New("no nodekey")
}
if name == "" {
return errors.New("missing 'name'")
}
if value == "" {
return errors.New("missing 'value'")
}
return cc.SetDNS(ctx, req)
}
func (b *LocalBackend) registerIncomingFile(inf *incomingFile, active bool) {
b.mu.Lock()
defer b.mu.Unlock()
if b.incomingFiles == nil {
b.incomingFiles = make(map[*incomingFile]bool)
}
if active {
b.incomingFiles[inf] = true
} else {
delete(b.incomingFiles, inf)
}
}
// peerAPIBase returns the "http://ip:port" URL base to reach peer's peerAPI.
// It returns the empty string if the peer doesn't support the peerapi
// or there's no matching address family based on the netmap's own addresses.
func peerAPIBase(nm *netmap.NetworkMap, peer *tailcfg.Node) string {
if nm == nil || peer == nil || !peer.Hostinfo.Valid() {
return ""
}
var have4, have6 bool
for _, a := range nm.Addresses {
if !a.IsSingleIP() {
continue
}
switch {
case a.Addr().Is4():
have4 = true
case a.Addr().Is6():
have6 = true
}
}
var p4, p6 uint16
svcs := peer.Hostinfo.Services()
for i, n := 0, svcs.Len(); i < n; i++ {
s := svcs.At(i)
switch s.Proto {
case tailcfg.PeerAPI4:
p4 = s.Port
case tailcfg.PeerAPI6:
p6 = s.Port
}
}
var ipp netip.AddrPort
switch {
case have4 && p4 != 0:
ipp = netip.AddrPortFrom(nodeIP(peer, netip.Addr.Is4), p4)
case have6 && p6 != 0:
ipp = netip.AddrPortFrom(nodeIP(peer, netip.Addr.Is6), p6)
}
if !ipp.Addr().IsValid() {
return ""
}
return fmt.Sprintf("http://%v", ipp)
}
func nodeIP(n *tailcfg.Node, pred func(netip.Addr) bool) netip.Addr {
for _, a := range n.Addresses {
if a.IsSingleIP() && pred(a.Addr()) {
return a.Addr()
}
}
return netip.Addr{}
}
func (b *LocalBackend) CheckIPForwarding() error {
if wgengine.IsNetstackRouter(b.e) {
return nil
}
// TODO: let the caller pass in the ranges.
warn, err := netutil.CheckIPForwarding(tsaddr.ExitRoutes(), nil)
if err != nil {
return err
}
return warn
}
// DERPMap returns the current DERPMap in use, or nil if not connected.
func (b *LocalBackend) DERPMap() *tailcfg.DERPMap {
b.mu.Lock()
defer b.mu.Unlock()
if b.netMap == nil {
return nil
}
return b.netMap.DERPMap
}
// OfferingExitNode reports whether b is currently offering exit node
// access.
func (b *LocalBackend) OfferingExitNode() bool {
b.mu.Lock()
defer b.mu.Unlock()
if b.prefs == nil {
return false
}
var def4, def6 bool
for _, r := range b.prefs.AdvertiseRoutes {
if r.Bits() != 0 {
continue
}
if r.Addr().Is4() {
def4 = true
} else if r.Addr().Is6() {
def6 = true
}
}
return def4 && def6
}
// allowExitNodeDNSProxyToServeName reports whether the Exit Node DNS
// proxy is allowed to serve responses for the provided DNS name.
func (b *LocalBackend) allowExitNodeDNSProxyToServeName(name string) bool {
b.mu.Lock()
defer b.mu.Unlock()
nm := b.netMap
if nm == nil {
return false
}
name = strings.ToLower(name)
for _, bad := range nm.DNS.ExitNodeFilteredSet {
if bad == "" {
// Invalid, ignore.
continue
}
if bad[0] == '.' {
// Entries beginning with a dot are suffix matches.
if dnsname.HasSuffix(name, bad) {
return false
}
continue
}
// Otherwise entries are exact matches. They're
// guaranteed to be lowercase already.
if name == bad {
return false
}
}
return true
}
// SetExpiry updates the expiry of the current node key to t, as long as it's
// only sooner than the old expiry.
//
// If t is in the past, the key is expired immediately.
// If t is after the current expiry, an error is returned.
func (b *LocalBackend) SetExpirySooner(ctx context.Context, expiry time.Time) error {
b.mu.Lock()
cc := b.ccAuto
b.mu.Unlock()
if cc == nil {
return errors.New("not running")
}
return cc.SetExpirySooner(ctx, expiry)
}
// exitNodeCanProxyDNS reports the DoH base URL ("http://foo/dns-query") without query parameters
// to exitNodeID's DoH service, if available.
//
// If exitNodeID is the zero valid, it returns "", false.
func exitNodeCanProxyDNS(nm *netmap.NetworkMap, exitNodeID tailcfg.StableNodeID) (dohURL string, ok bool) {
if exitNodeID.IsZero() {
return "", false
}
for _, p := range nm.Peers {
if p.StableID != exitNodeID {
continue
}
services := p.Hostinfo.Services()
for i, n := 0, services.Len(); i < n; i++ {
s := services.At(i)
if s.Proto == tailcfg.PeerAPIDNS && s.Port >= 1 {
return peerAPIBase(nm, p) + "/dns-query", true
}
}
}
return "", false
}
func (b *LocalBackend) DebugRebind() error {
mc, err := b.magicConn()
if err != nil {
return err
}
mc.Rebind()
return nil
}
func (b *LocalBackend) DebugReSTUN() error {
mc, err := b.magicConn()
if err != nil {
return err
}
mc.ReSTUN("explicit-debug")
return nil
}
func (b *LocalBackend) magicConn() (*magicsock.Conn, error) {
ig, ok := b.e.(wgengine.InternalsGetter)
if !ok {
return nil, errors.New("engine isn't InternalsGetter")
}
_, mc, _, ok := ig.GetInternals()
if !ok {
return nil, errors.New("failed to get internals")
}
return mc, nil
}
// DoNoiseRequest sends a request to URL over the control plane
// Noise connection.
func (b *LocalBackend) DoNoiseRequest(req *http.Request) (*http.Response, error) {
b.mu.Lock()
cc := b.ccAuto
b.mu.Unlock()
if cc == nil {
return nil, errors.New("no client")
}
return cc.DoNoiseRequest(req)
}
// tailscaleSSHEnabled reports whether Tailscale SSH is currently enabled based
// on prefs. It returns false if there are no prefs set.
func (b *LocalBackend) tailscaleSSHEnabled() bool {
b.mu.Lock()
defer b.mu.Unlock()
if b.prefs == nil {
return false
}
return b.prefs.RunSSH
}
func (b *LocalBackend) sshServerOrInit() (_ SSHServer, err error) {
b.mu.Lock()
defer b.mu.Unlock()
if b.sshServer != nil {
return b.sshServer, nil
}
if newSSHServer == nil {
return nil, errors.New("no SSH server support")
}
b.sshServer, err = newSSHServer(b.logf, b)
if err != nil {
return nil, fmt.Errorf("newSSHServer: %w", err)
}
return b.sshServer, nil
}
func (b *LocalBackend) HandleSSHConn(c net.Conn) (err error) {
s, err := b.sshServerOrInit()
if err != nil {
return err
}
return s.HandleSSHConn(c)
}
// HandleQuad100Port80Conn serves http://100.100.100.100/ on port 80 (and
// the equivalent tsaddr.TailscaleServiceIPv6 address).
func (b *LocalBackend) HandleQuad100Port80Conn(c net.Conn) {
var s http.Server
s.Handler = http.HandlerFunc(b.handleQuad100Port80Conn)
s.Serve(netutil.NewOneConnListener(c, nil))
}
func (b *LocalBackend) handleQuad100Port80Conn(w http.ResponseWriter, r *http.Request) {
w.Header().Set("X-Frame-Options", "DENY")
w.Header().Set("Content-Security-Policy", "default-src 'self';")
if r.Method != "GET" && r.Method != "HEAD" {
http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
return
}
b.mu.Lock()
defer b.mu.Unlock()
io.WriteString(w, "<h1>Tailscale</h1>\n")
if b.netMap == nil {
io.WriteString(w, "No netmap.\n")
return
}
if len(b.netMap.Addresses) == 0 {
io.WriteString(w, "No local addresses.\n")
return
}
io.WriteString(w, "<p>Local addresses:</p><ul>\n")
for _, ipp := range b.netMap.Addresses {
fmt.Fprintf(w, "<li>%v</li>\n", ipp.Addr())
}
io.WriteString(w, "</ul>\n")
}
func (b *LocalBackend) Doctor(ctx context.Context, logf logger.Logf) {
var checks []doctor.Check
checks = append(checks, routetable.Check{})
// TODO(andrew): more
numChecks := len(checks)
checks = append(checks, doctor.CheckFunc("numchecks", func(_ context.Context, log logger.Logf) error {
log("%d checks", numChecks)
return nil
}))
doctor.RunChecks(ctx, logf, checks...)
}
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