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tailscale/ipn/local.go

1401 lines
37 KiB
Go

// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package ipn
import (
"bytes"
"context"
"errors"
"fmt"
"os"
"strings"
"sync"
"time"
"github.com/tailscale/wireguard-go/wgcfg"
"golang.org/x/oauth2"
"inet.af/netaddr"
"tailscale.com/control/controlclient"
"tailscale.com/internal/deepprint"
"tailscale.com/ipn/ipnstate"
"tailscale.com/ipn/policy"
"tailscale.com/net/interfaces"
"tailscale.com/net/tsaddr"
"tailscale.com/portlist"
"tailscale.com/tailcfg"
"tailscale.com/types/empty"
"tailscale.com/types/key"
"tailscale.com/types/logger"
"tailscale.com/version"
"tailscale.com/wgengine"
"tailscale.com/wgengine/filter"
"tailscale.com/wgengine/router"
"tailscale.com/wgengine/router/dns"
"tailscale.com/wgengine/tsdns"
)
// 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
e wgengine.Engine
store StateStore
backendLogID string
portpoll *portlist.Poller // may be nil
portpollOnce sync.Once
serverURL string // tailcontrol URL
newDecompressor func() (controlclient.Decompressor, error)
filterHash string
// The mutex protects the following elements.
mu sync.Mutex
notify func(Notify)
c *controlclient.Client
stateKey StateKey
prefs *Prefs
machinePrivKey wgcfg.PrivateKey
state State
// hostinfo is mutated in-place while mu is held.
hostinfo *tailcfg.Hostinfo
// netMap is not mutated in-place once set.
netMap *controlclient.NetworkMap
engineStatus EngineStatus
endpoints []string
blocked bool
authURL string
interact int
prevIfState *interfaces.State
// statusLock must be held before calling statusChanged.Wait() or
// statusChanged.Broadcast().
statusLock sync.Mutex
statusChanged *sync.Cond
}
// NewLocalBackend returns a new LocalBackend that is ready to run,
// but is not actually running.
func NewLocalBackend(logf logger.Logf, logid string, store StateStore, e wgengine.Engine) (*LocalBackend, error) {
if e == nil {
panic("ipn.NewLocalBackend: wgengine must not be nil")
}
// Default filter blocks everything, until Start() is called.
e.SetFilter(filter.NewAllowNone(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),
e: e,
store: store,
backendLogID: logid,
state: NoState,
portpoll: portpoll,
}
e.SetLinkChangeCallback(b.linkChange)
b.statusChanged = sync.NewCond(&b.statusLock)
return b, nil
}
// linkChange is called (in a new goroutine) by wgengine when its link monitor
// detects a network change.
func (b *LocalBackend) linkChange(major bool, ifst *interfaces.State) {
b.mu.Lock()
defer b.mu.Unlock()
// On transition from no PAC to PAC, assume we're
// roaming into some corp network where the corp HTTP
// proxy & Windows Domain Controller & DNS etc all
// might be behind subnet routes that we've otherwise
// shadowed.
//
// So remove all our routes and reset the control connections
gotPAC := ifst.PAC != "" && b.prevIfState != nil && b.prevIfState.PAC == ""
if gotPAC {
b.logf("linkChange: entering PAC network, resetting; state=%v", b.state)
b.e.Reconfig(&wgcfg.Config{}, &router.Config{})
b.logf("linkChange: did wg+router reset")
if b.c != nil && b.state != Stopped {
// Pause and unpause the client to reset its
// HTTP connections.
// TODO(bradfitz): this is somewhat gross. Add
// a more explicit method to the client.
b.c.SetPaused(true)
b.c.SetPaused(false)
b.logf("linkChange: did control client reset")
}
}
b.prevIfState = ifst
}
// 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()
cli := b.c
b.mu.Unlock()
if cli != nil {
cli.Shutdown()
}
b.ctxCancel()
b.e.Close()
b.e.Wait()
}
// 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()
}
// UpdateStatus implements ipnstate.StatusUpdater.
func (b *LocalBackend) UpdateStatus(sb *ipnstate.StatusBuilder) {
b.e.UpdateStatus(sb)
b.mu.Lock()
defer b.mu.Unlock()
sb.SetBackendState(b.state.String())
// TODO: hostinfo, and its networkinfo
// TODO: EngineStatus copy (and deprecate it?)
if b.netMap != nil {
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 tailAddr string
if len(p.Addresses) > 0 {
tailAddr = strings.TrimSuffix(p.Addresses[0].String(), "/32")
}
sb.AddPeer(key.Public(p.Key), &ipnstate.PeerStatus{
InNetworkMap: true,
UserID: p.User,
TailAddr: tailAddr,
HostName: p.Hostinfo.Hostname,
DNSName: p.Name,
OS: p.Hostinfo.OS,
KeepAlive: p.KeepAlive,
Created: p.Created,
LastSeen: lastSeen,
})
}
}
}
// 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 != "" {
// TODO(crawshaw): display in the UI.
b.logf("Received error: %v", st.Err)
return
}
if st.LoginFinished != nil {
// Auth completed, unblock the engine
b.blockEngineUpdates(false)
b.authReconfig()
b.send(Notify{LoginFinished: &empty.Message{}})
}
prefsChanged := false
// Lock b once and do only the things that require locking.
b.mu.Lock()
prefs := b.prefs
stateKey := b.stateKey
netMap := b.netMap
interact := b.interact
if st.Persist != nil {
if !b.prefs.Persist.Equals(st.Persist) {
prefsChanged = true
b.prefs.Persist = st.Persist.Clone()
}
}
if st.NetMap != nil {
b.netMap = st.NetMap
}
if st.URL != "" {
b.authURL = st.URL
}
if b.state == NeedsLogin {
if !b.prefs.WantRunning {
prefsChanged = true
}
b.prefs.WantRunning = true
}
// Prefs will be written out; this is not safe unless locked or cloned.
if prefsChanged {
prefs = b.prefs.Clone()
}
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(Notify{Prefs: prefs})
}
if st.NetMap != nil {
if netMap != nil {
diff := st.NetMap.ConciseDiffFrom(netMap)
if strings.TrimSpace(diff) == "" {
b.logf("netmap diff: (none)")
} else {
b.logf("netmap diff:\n%v", diff)
}
}
b.updateFilter(st.NetMap, prefs)
b.e.SetNetworkMap(st.NetMap)
if !dnsMapsEqual(st.NetMap, netMap) {
b.updateDNSMap(st.NetMap)
}
b.e.SetDERPMap(st.NetMap.DERPMap)
b.send(Notify{NetMap: st.NetMap})
}
if st.URL != "" {
b.logf("Received auth URL: %.20v...", st.URL)
if interact > 0 {
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()
}
// 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)
return
}
if s == nil {
b.logf("[unexpected] non-error wgengine update with status=nil: %v", s)
return
}
es := b.parseWgStatus(s)
b.mu.Lock()
c := b.c
b.engineStatus = es
b.endpoints = append([]string{}, s.LocalAddrs...)
b.mu.Unlock()
if c != nil {
c.UpdateEndpoints(0, s.LocalAddrs)
}
b.stateMachine()
b.statusLock.Lock()
b.statusChanged.Broadcast()
b.statusLock.Unlock()
b.send(Notify{Engine: &es})
}
// 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 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")
}
hostinfo := controlclient.NewHostinfo()
hostinfo.BackendLogID = b.backendLogID
hostinfo.FrontendLogID = opts.FrontendLogID
b.mu.Lock()
if b.c != 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.c.Shutdown()
}
if b.hostinfo != nil {
hostinfo.Services = b.hostinfo.Services // keep any previous session and netinfo
hostinfo.NetInfo = b.hostinfo.NetInfo
}
b.hostinfo = hostinfo
b.state = NoState
if err := b.loadStateLocked(opts.StateKey, opts.Prefs, opts.LegacyConfigPath); err != nil {
b.mu.Unlock()
return fmt.Errorf("loading requested state: %v", err)
}
b.serverURL = b.prefs.ControlURL
hostinfo.RoutableIPs = append(hostinfo.RoutableIPs, b.prefs.AdvertiseRoutes...)
hostinfo.RequestTags = append(hostinfo.RequestTags, b.prefs.AdvertiseTags...)
applyPrefsToHostinfo(hostinfo, b.prefs)
b.notify = opts.Notify
b.netMap = nil
persist := b.prefs.Persist
machinePrivKey := b.machinePrivKey
b.mu.Unlock()
b.updateFilter(nil, nil)
var discoPublic tailcfg.DiscoKey
if controlclient.Debug.Disco {
discoPublic = b.e.DiscoPublicKey()
}
var err error
if persist == nil {
// let controlclient initialize it
persist = &controlclient.Persist{}
}
cli, err := controlclient.New(controlclient.Options{
MachinePrivateKey: machinePrivKey,
Logf: logger.WithPrefix(b.logf, "control: "),
Persist: *persist,
ServerURL: b.serverURL,
AuthKey: opts.AuthKey,
Hostinfo: hostinfo,
KeepAlive: true,
NewDecompressor: b.newDecompressor,
HTTPTestClient: opts.HTTPTestClient,
DiscoPublicKey: discoPublic,
})
if err != nil {
return err
}
// At this point, we have finished using hostinfo without synchronization,
// so it is safe to start readPoller which concurrently writes to it.
if b.portpoll != nil {
b.portpollOnce.Do(func() {
go b.portpoll.Run(b.ctx)
go b.readPoller()
})
}
b.mu.Lock()
b.c = cli
endpoints := b.endpoints
b.mu.Unlock()
if endpoints != nil {
cli.UpdateEndpoints(0, endpoints)
}
cli.SetStatusFunc(b.setClientStatus)
b.e.SetStatusCallback(b.setWgengineStatus)
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(Notify{BackendLogID: &blid})
b.send(Notify{Prefs: prefs})
cli.Login(nil, controlclient.LoginDefault)
return nil
}
// updateFilter updates the packet filter in wgengine based on the
// given netMap and user preferences.
func (b *LocalBackend) updateFilter(netMap *controlclient.NetworkMap, prefs *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 []wgcfg.CIDR
packetFilter filter.Matches
advRoutes []wgcfg.CIDR
shieldsUp = prefs == nil || prefs.ShieldsUp // Be conservative when not ready
)
if haveNetmap {
addrs = netMap.Addresses
packetFilter = netMap.PacketFilter
}
if prefs != nil {
advRoutes = prefs.AdvertiseRoutes
}
changed := deepprint.UpdateHash(&b.filterHash, haveNetmap, addrs, packetFilter, advRoutes, shieldsUp)
if !changed {
return
}
if !haveNetmap {
b.logf("netmap packet filter: (not ready yet)")
b.e.SetFilter(filter.NewAllowNone(b.logf))
return
}
localNets := wgCIDRsToFilter(netMap.Addresses, advRoutes)
if shieldsUp {
b.logf("netmap packet filter: (shields up)")
var prevFilter *filter.Filter // don't reuse old filter state
b.e.SetFilter(filter.New(filter.Matches{}, localNets, prevFilter, b.logf))
} else {
b.logf("netmap packet filter: %v", packetFilter)
b.e.SetFilter(filter.New(packetFilter, localNets, b.e.GetFilter(), b.logf))
}
}
// dnsCIDRsEqual determines whether two CIDR lists are equal
// for DNS map construction purposes (that is, only the first entry counts).
func dnsCIDRsEqual(newAddr, oldAddr []wgcfg.CIDR) 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 *controlclient.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
}
// updateDNSMap updates the domain map in the DNS resolver in wgengine
// based on the given netMap and user preferences.
func (b *LocalBackend) updateDNSMap(netMap *controlclient.NetworkMap) {
if netMap == nil {
b.logf("dns map: (not ready)")
return
}
nameToIP := make(map[string]netaddr.IP)
set := func(name string, addrs []wgcfg.CIDR) {
if len(addrs) == 0 || name == "" {
return
}
nameToIP[name] = netaddr.IPFrom16(addrs[0].IP.Addr)
}
for _, peer := range netMap.Peers {
set(peer.Name, peer.Addresses)
}
set(netMap.Name, netMap.Addresses)
dnsMap := tsdns.NewMap(nameToIP, domainsForProxying(netMap))
// map diff will be logged in tsdns.Resolver.SetMap.
b.e.SetDNSMap(dnsMap)
}
// readPoller is a goroutine that receives service lists from
// b.portpoll and propagates them into the controlclient's HostInfo.
func (b *LocalBackend) readPoller() {
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)
}
}
// send delivers n to the connected frontend. If no frontend is
// connected, the notification is dropped without being delivered.
func (b *LocalBackend) send(n Notify) {
b.mu.Lock()
notify := b.notify
b.mu.Unlock()
if notify != nil {
n.Version = version.LONG
notify(n)
} else {
b.logf("nil notify callback; dropping %+v", 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 = 0
b.authURL = ""
b.mu.Unlock()
b.logf("popBrowserAuthNow: url=%v", url != "")
b.blockEngineUpdates(true)
b.stopEngineAndWait()
b.send(Notify{BrowseToURL: &url})
if b.State() == Running {
b.enterState(Starting)
}
}
// initMachineKeyLocked is called to initialize b.machinePrivKey.
//
// b.prefs must already be initialized.
// b.mu must be held.
func (b *LocalBackend) initMachineKeyLocked() error {
if !b.machinePrivKey.IsZero() {
// Already set.
return nil
}
var legacyMachineKey wgcfg.PrivateKey
if b.prefs.Persist != nil {
legacyMachineKey = b.prefs.Persist.LegacyFrontendPrivateMachineKey
}
keyText, err := b.store.ReadState(MachineKeyStateKey)
if err == nil {
if err := b.machinePrivKey.UnmarshalText(keyText); err != nil {
return fmt.Errorf("invalid key in %s key of %v: %w", MachineKeyStateKey, b.store, err)
}
if b.machinePrivKey.IsZero() {
return fmt.Errorf("invalid zero key stored in %v key of %v", MachineKeyStateKey, b.store)
}
if !legacyMachineKey.IsZero() && !bytes.Equal(legacyMachineKey[:], b.machinePrivKey[:]) {
b.logf("frontend-provided legacy machine key ignored; used value from server state")
}
return nil
}
if err != ErrStateNotExist {
return fmt.Errorf("error reading %v key of %v: %w", 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() {
b.logf("using frontend-provided legacy machine key")
b.machinePrivKey = legacyMachineKey
} else {
b.logf("generating new machine key")
var err error
b.machinePrivKey, err = wgcfg.NewPrivateKey()
if err != nil {
return fmt.Errorf("initializing new machine key: %w", err)
}
}
keyText, _ = b.machinePrivKey.MarshalText()
if err := b.store.WriteState(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
}
// 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 StateKey, prefs *Prefs, legacyPath string) error {
if prefs == nil && key == "" {
panic("state key and prefs are both unset")
}
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")
b.prefs = prefs.Clone()
if err := b.initMachineKeyLocked(); err != nil {
return fmt.Errorf("initMachineKeyLocked: %w", err)
}
b.stateKey = ""
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")
if err := b.store.WriteState(key, prefs.ToBytes()); err != nil {
return fmt.Errorf("store.WriteState: %v", err)
}
}
b.logf("Using backend prefs")
bs, err := b.store.ReadState(key)
if err != nil {
if errors.Is(err, ErrStateNotExist) {
if legacyPath != "" {
b.prefs, err = LoadPrefs(legacyPath)
if err != nil {
if !os.IsNotExist(err) {
b.logf("Failed to load legacy prefs: %v", err)
}
b.prefs = NewPrefs()
} else {
b.logf("Imported state from relaynode for %q", key)
}
} else {
b.prefs = NewPrefs()
b.logf("Created empty state for %q", key)
}
if err := b.initMachineKeyLocked(); err != nil {
return fmt.Errorf("initMachineKeyLocked: %w", err)
}
b.stateKey = key
return nil
}
return fmt.Errorf("store.ReadState(%q): %v", key, err)
}
b.prefs, err = PrefsFromBytes(bs, false)
if err != nil {
return fmt.Errorf("PrefsFromBytes: %v", err)
}
b.stateKey = key
if err := b.initMachineKeyLocked(); err != nil {
return fmt.Errorf("initMachineKeyLocked: %w", err)
}
return nil
}
// State returns the backend state machine's current state.
func (b *LocalBackend) State() State {
b.mu.Lock()
defer b.mu.Unlock()
return b.state
}
// getEngineStatus returns a copy of b.engineStatus.
//
// TODO(bradfitz): remove this and use Status() throughout.
func (b *LocalBackend) getEngineStatus() EngineStatus {
b.mu.Lock()
defer b.mu.Unlock()
return b.engineStatus
}
// Login implements Backend.
func (b *LocalBackend) Login(token *oauth2.Token) {
b.mu.Lock()
b.assertClientLocked()
c := b.c
b.mu.Unlock()
c.Login(token, 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++
url := b.authURL
c := b.c
b.mu.Unlock()
b.logf("StartLoginInteractive: url=%v", url != "")
if url != "" {
b.popBrowserAuthNow()
} else {
c.Login(nil, controlclient.LoginInteractive)
}
}
// FakeExpireAfter implements Backend.
func (b *LocalBackend) FakeExpireAfter(x time.Duration) {
b.logf("FakeExpireAfter: %v", x)
b.mu.Lock()
defer b.mu.Unlock()
if b.netMap == nil {
return
}
// This function is called very rarely,
// so we prefer to fully copy the netmap over introducing in-place modification here.
mapCopy := *b.netMap
e := mapCopy.Expiry
if e.IsZero() || time.Until(e) > x {
mapCopy.Expiry = time.Now().Add(x)
}
b.netMap = &mapCopy
b.send(Notify{NetMap: b.netMap})
}
func (b *LocalBackend) Ping(ipStr string) {
ip, err := netaddr.ParseIP(ipStr)
if err != nil {
b.logf("ignoring Ping request to invalid IP %q", ipStr)
return
}
b.e.Ping(ip, func(pr *ipnstate.PingResult) {
b.send(Notify{PingResult: pr})
})
}
func (b *LocalBackend) parseWgStatus(s *wgengine.Status) (ret EngineStatus) {
var (
peerStats []string
peerKeys []string
)
ret.LiveDERPs = s.DERPs
ret.LivePeers = map[tailcfg.NodeKey]wgengine.PeerStatus{}
for _, p := range s.Peers {
if !p.LastHandshake.IsZero() {
peerStats = append(peerStats, fmt.Sprintf("%d/%d", p.RxBytes, p.TxBytes))
ret.NumLive++
ret.LivePeers[p.NodeKey] = p
peerKeys = append(peerKeys, p.NodeKey.ShortString())
}
ret.RBytes += p.RxBytes
ret.WBytes += p.TxBytes
}
if len(peerStats) > 0 {
// [GRINDER STATS LINE] - please don't remove (used for log parsing)
b.keyLogf("peer keys: %s", strings.Join(peerKeys, " "))
// [GRINDER STATS LINE] - please don't remove (used for log parsing)
b.logf("v%v peers: %v", version.LONG, strings.Join(peerStats, " "))
}
return ret
}
// shieldsAreUp returns whether user preferences currently request
// "shields up" mode, which disallows all inbound connections.
func (b *LocalBackend) shieldsAreUp() bool {
b.mu.Lock()
defer b.mu.Unlock()
if b.prefs == nil {
return true // default to safest setting
}
return b.prefs.ShieldsUp
}
func (b *LocalBackend) SetWantRunning(wantRunning bool) {
b.mu.Lock()
new := b.prefs.Clone()
b.mu.Unlock()
if new.WantRunning == wantRunning {
return
}
new.WantRunning = wantRunning
b.logf("SetWantRunning: %v", wantRunning)
b.SetPrefs(new)
}
// SetPrefs saves new user preferences and propagates them throughout
// the system. Implements Backend.
func (b *LocalBackend) SetPrefs(new *Prefs) {
if new == nil {
panic("SetPrefs got nil prefs")
}
b.mu.Lock()
netMap := b.netMap
stateKey := b.stateKey
old := b.prefs
new.Persist = old.Persist // caller isn't allowed to override this
b.prefs = new
// We do this to avoid holding the lock while doing everything else.
new = b.prefs.Clone()
oldHi := b.hostinfo
newHi := oldHi.Clone()
newHi.RoutableIPs = append([]wgcfg.CIDR(nil), b.prefs.AdvertiseRoutes...)
applyPrefsToHostinfo(newHi, new)
b.hostinfo = newHi
hostInfoChanged := !oldHi.Equal(newHi)
b.mu.Unlock()
if stateKey != "" {
if err := b.store.WriteState(stateKey, new.ToBytes()); err != nil {
b.logf("Failed to save new controlclient state: %v", err)
}
}
// [GRINDER STATS LINE] - please don't remove (used for log parsing)
b.logf("SetPrefs: %v", new.Pretty())
if old.ShieldsUp != new.ShieldsUp || hostInfoChanged {
b.doSetHostinfoFilterServices(newHi)
}
b.updateFilter(netMap, new)
if netMap != nil {
b.e.SetDERPMap(netMap.DERPMap)
}
if old.WantRunning != new.WantRunning {
b.stateMachine()
} else {
b.authReconfig()
}
b.send(Notify{Prefs: new})
}
// 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) {
hi2 := *hi
if b.shieldsAreUp() {
// No local services are available, since ShieldsUp will block
// them all.
hi2.Services = []tailcfg.Service{}
}
b.mu.Lock()
cli := b.c
b.mu.Unlock()
// b.c might not be started yet
if cli != nil {
cli.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() *controlclient.NetworkMap {
b.mu.Lock()
defer b.mu.Unlock()
return b.netMap
}
// 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
uc := b.prefs
nm := b.netMap
b.mu.Unlock()
if blocked {
b.logf("authReconfig: blocked, skipping.")
return
}
if nm == nil {
b.logf("authReconfig: netmap not yet valid. Skipping.")
return
}
if !uc.WantRunning {
b.logf("authReconfig: skipping because !WantRunning.")
return
}
var flags controlclient.WGConfigFlags
if uc.RouteAll {
flags |= controlclient.AllowDefaultRoute
// TODO(apenwarr): Make subnet routes a different pref?
flags |= controlclient.AllowSubnetRoutes
}
if uc.AllowSingleHosts {
flags |= controlclient.AllowSingleHosts
}
cfg, err := nm.WGCfg(b.logf, flags)
if err != nil {
b.logf("wgcfg: %v", err)
return
}
rcfg := routerConfig(cfg, uc)
// If CorpDNS is false, rcfg.DNS remains the zero value.
if uc.CorpDNS {
domains := nm.DNS.Domains
proxied := nm.DNS.Proxied
if proxied {
if len(nm.DNS.Nameservers) == 0 {
b.logf("[unexpected] dns proxied but no nameservers")
proxied = false
} else {
// Domains for proxying should come first to avoid leaking queries.
domains = append(domainsForProxying(nm), domains...)
}
}
rcfg.DNS = dns.Config{
Nameservers: nm.DNS.Nameservers,
Domains: domains,
PerDomain: nm.DNS.PerDomain,
Proxied: proxied,
}
}
err = b.e.Reconfig(cfg, rcfg)
if err == wgengine.ErrNoChanges {
return
}
b.logf("authReconfig: ra=%v dns=%v 0x%02x: %v", uc.RouteAll, uc.CorpDNS, flags, err)
}
// domainsForProxying produces a list of search domains for proxied DNS.
func domainsForProxying(nm *controlclient.NetworkMap) []string {
var domains []string
if idx := strings.IndexByte(nm.Name, '.'); idx != -1 {
domains = append(domains, nm.Name[idx+1:])
}
for _, peer := range nm.Peers {
idx := strings.IndexByte(peer.Name, '.')
if idx == -1 {
continue
}
domain := peer.Name[idx+1:]
seen := false
// In theory this makes the function O(n^2) worst case,
// but in practice we expect domains to contain very few elements
// (only one until invitations are introduced).
for _, seenDomain := range domains {
if domain == seenDomain {
seen = true
}
}
if !seen {
domains = append(domains, domain)
}
}
return domains
}
// routerConfig produces a router.Config from a wireguard config and IPN prefs.
func routerConfig(cfg *wgcfg.Config, prefs *Prefs) *router.Config {
var addrs []wgcfg.CIDR
for _, addr := range cfg.Addresses {
addrs = append(addrs, wgcfg.CIDR{
IP: addr.IP,
Mask: 32,
})
}
rs := &router.Config{
LocalAddrs: wgCIDRToNetaddr(addrs),
SubnetRoutes: wgCIDRToNetaddr(prefs.AdvertiseRoutes),
SNATSubnetRoutes: !prefs.NoSNAT,
NetfilterMode: prefs.NetfilterMode,
}
for _, peer := range cfg.Peers {
rs.Routes = append(rs.Routes, wgCIDRToNetaddr(peer.AllowedIPs)...)
}
rs.Routes = append(rs.Routes, netaddr.IPPrefix{
IP: tsaddr.TailscaleServiceIP(),
Bits: 32,
})
return rs
}
// wgCIDRsToFilter converts lists of wgcfg.CIDR into a single list of
// filter.Net.
func wgCIDRsToFilter(cidrLists ...[]wgcfg.CIDR) (ret []filter.Net) {
for _, cidrs := range cidrLists {
for _, cidr := range cidrs {
if !cidr.IP.Is4() {
continue
}
ret = append(ret, filter.Net{
IP: filter.NewIP(cidr.IP.IP()),
Mask: filter.Netmask(int(cidr.Mask)),
})
}
}
return ret
}
func wgCIDRToNetaddr(cidrs []wgcfg.CIDR) (ret []netaddr.IPPrefix) {
for _, cidr := range cidrs {
ncidr, ok := netaddr.FromStdIPNet(cidr.IPNet())
if !ok {
panic(fmt.Sprintf("conversion of %s from wgcfg to netaddr IPNet failed", cidr))
}
ncidr.IP = ncidr.IP.Unmap()
ret = append(ret, ncidr)
}
return ret
}
func applyPrefsToHostinfo(hi *tailcfg.Hostinfo, prefs *Prefs) {
if h := prefs.Hostname; h != "" {
hi.Hostname = h
}
if v := prefs.OSVersion; v != "" {
hi.OSVersion = v
}
if m := prefs.DeviceModel; m != "" {
hi.DeviceModel = m
}
}
// 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 State) {
b.mu.Lock()
state := b.state
b.state = newState
prefs := b.prefs
notify := b.notify
bc := b.c
b.mu.Unlock()
if state == newState {
return
}
b.logf("Switching ipn state %v -> %v (WantRunning=%v)",
state, newState, prefs.WantRunning)
if notify != nil {
b.send(Notify{State: &newState})
}
if bc != nil {
bc.SetPaused(newState == Stopped)
}
switch newState {
case NeedsLogin:
b.blockEngineUpdates(true)
fallthrough
case Stopped:
err := b.e.Reconfig(&wgcfg.Config{}, &router.Config{})
if err != nil {
b.logf("Reconfig(down): %v", err)
}
case Starting, NeedsMachineAuth:
b.authReconfig()
// Needed so that UpdateEndpoints can run
b.e.RequestStatus()
case Running:
break
default:
b.logf("[unexpected] unknown newState %#v", newState)
}
}
// nextState returns the state the backend seems to be in, based on
// its internal state.
func (b *LocalBackend) nextState() State {
b.mu.Lock()
b.assertClientLocked()
var (
c = b.c
netMap = b.netMap
state = b.state
wantRunning = b.prefs.WantRunning
)
b.mu.Unlock()
switch {
case netMap == nil:
if c.AuthCantContinue() {
// Auth was interrupted or waiting for URL visit,
// so it won't proceed without human help.
return NeedsLogin
} else {
// Auth or map request needs to finish
return state
}
case !wantRunning:
return Stopped
case !netMap.Expiry.IsZero() && time.Until(netMap.Expiry) <= 0:
return NeedsLogin
case netMap.MachineStatus != tailcfg.MachineAuthorized:
// TODO(crawshaw): handle tailcfg.MachineInvalid
return NeedsMachineAuth
case state == NeedsMachineAuth:
// (if we get here, we know MachineAuthorized == true)
return Starting
case state == Starting:
if st := b.getEngineStatus(); st.NumLive > 0 || st.LiveDERPs > 0 {
return Running
} else {
return state
}
case state == Running:
return Running
default:
return Starting
}
}
// RequestEngineStatus implements Backend.
func (b *LocalBackend) RequestEngineStatus() {
b.e.RequestStatus()
}
// RequestStatus implements Backend.
func (b *LocalBackend) RequestStatus() {
st := b.Status()
b.send(Notify{Status: st})
}
// 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 re-entrancy?
// 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{})
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()
}
// 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.
//
// TODO(danderson): controlclient Logout does nothing useful, and we
// shouldn't be transitioning to a state based on what we believe
// controlclient may have done.
//
// NOTE(apenwarr): No easy way to persist logged-out status.
// Maybe that's for the better; if someone logs out accidentally,
// rebooting will fix it.
func (b *LocalBackend) Logout() {
b.mu.Lock()
c := b.c
b.netMap = nil
b.mu.Unlock()
if c == 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
}
c.Logout()
b.mu.Lock()
b.netMap = nil
b.mu.Unlock()
b.stateMachine()
}
// assertClientLocked crashes if there is no controlclient in this backend.
func (b *LocalBackend) assertClientLocked() {
if b.c == nil {
panic("LocalBackend.assertClient: b.c == 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()
c := b.c
if b.hostinfo != nil {
b.hostinfo.NetInfo = ni.Clone()
}
b.mu.Unlock()
if c == nil {
return
}
c.SetNetInfo(ni)
}
// 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 tailcfg.MachineKey, nodeKey tailcfg.NodeKey) {
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 tailcfg.MachineKey(mk), tailcfg.NodeKey(nk)
}