// Copyright (c) Tailscale Inc & AUTHORS // SPDX-License-Identifier: BSD-3-Clause package ipnlocal import ( "bytes" "context" "encoding/base64" "encoding/json" "errors" "fmt" "io" "net" "net/http" "net/http/httputil" "net/netip" "net/url" "os" "os/exec" "os/user" "path/filepath" "runtime" "sort" "strconv" "strings" "sync" "sync/atomic" "time" "go4.org/mem" "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/health/healthmsg" "tailscale.com/hostinfo" "tailscale.com/ipn" "tailscale.com/ipn/ipnauth" "tailscale.com/ipn/ipnstate" "tailscale.com/ipn/policy" "tailscale.com/net/dns" "tailscale.com/net/dnscache" "tailscale.com/net/dnsfallback" "tailscale.com/net/interfaces" "tailscale.com/net/netns" "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/ptr" "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/set" "tailscale.com/util/systemd" "tailscale.com/util/uniq" "tailscale.com/version" "tailscale.com/version/distro" "tailscale.com/wgengine" "tailscale.com/wgengine/capture" "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 pm *profileManager 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 newDecompressor func() (controlclient.Decompressor, error) varRoot string // or empty if SetVarRoot never called logFlushFunc func() // or nil if SetLogFlusher wasn't called em *expiryManager // non-nil sshAtomicBool atomic.Bool shutdownCalled bool // if Shutdown has been called debugSink *capture.Sink // getTCPHandlerForFunnelFlow returns a handler for an incoming TCP flow for // the provided srcAddr and dstPort if one exists. // // srcAddr is the source address of the flow, not the address of the Funnel // node relaying the flow. // dstPort is the destination port of the flow. // // It returns nil if there is no known handler for this flow. // // This is specifically used to handle TCP flows for Funnel connections to tsnet // servers. // // It is set once during initialization, and can be nil if SetTCPHandlerForFunnelFlow // is never called. getTCPHandlerForFunnelFlow func(srcAddr netip.AddrPort, dstPort uint16) (handler func(net.Conn)) // lastProfileID tracks the last profile we've seen from the ProfileManager. // It's used to detect when the user has changed their profile. lastProfileID ipn.ProfileID filterAtomic atomic.Pointer[filter.Filter] containsViaIPFuncAtomic syncs.AtomicValue[func(netip.Addr) bool] shouldInterceptTCPPortAtomic syncs.AtomicValue[func(uint16) bool] numClientStatusCalls atomic.Uint32 // 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 machinePrivKey key.MachinePrivate tka *tkaState state ipn.State capFileSharing bool // whether netMap contains the file sharing capability capTailnetLock bool // whether netMap contains the tailnet lock capability // hostinfo is mutated in-place while mu is held. hostinfo *tailcfg.Hostinfo // netMap is not mutated in-place once set. netMap *netmap.NetworkMap nmExpiryTimer *time.Timer // for updating netMap on node expiry; can be nil 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 fileWaiters set.HandleSet[context.CancelFunc] // of wake-up funcs notifyWatchers set.HandleSet[chan *ipn.Notify] 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 // ServeConfig fields. (also guarded by mu) lastServeConfJSON mem.RO // last JSON that was parsed into serveConfig serveConfig ipn.ServeConfigView // or !Valid if none serveListeners map[netip.AddrPort]*serveListener // addrPort => serveListener serveProxyHandlers sync.Map // string (HTTPHandler.Proxy) => *httputil.ReverseProxy // 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") } pm, err := newProfileManager(store, logf) if err != nil { return nil, err } 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, pm: pm, store: pm.Store(), dialer: dialer, backendLogID: logid, state: ipn.NoState, portpoll: portpoll, em: newExpiryManager(logf), 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.setTCPPortsIntercepted(nil) 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 PeerAPI port for engine %T", e) } for _, component := range debuggableComponents { key := componentStateKey(component) if ut, err := ipn.ReadStoreInt(pm.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 } // GetComponentDebugLogging gets the time that component's debug logging is // enabled until, or the zero time if component's time is not currently // enabled. func (b *LocalBackend) GetComponentDebugLogging(component string) time.Time { b.mu.Lock() defer b.mu.Unlock() now := time.Now() ls := b.componentLogUntil[component] if ls.until.IsZero() || ls.until.Before(now) { return time.Time{} } return ls.until } // 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.pm.CurrentPrefs()) 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() if b.debugSink != nil { b.e.InstallCaptureHook(nil) b.debugSink.Close() b.debugSink = nil } b.mu.Unlock() b.unregisterLinkMon() b.unregisterHealthWatch() if cc != nil { cc.Shutdown() } b.ctxCancel() b.e.Close() b.e.Wait() } func stripKeysFromPrefs(p ipn.PrefsView) ipn.PrefsView { if !p.Valid() || !p.Persist().Valid() { return p } p2 := p.AsStruct() p2.Persist.LegacyFrontendPrivateMachineKey = key.MachinePrivate{} p2.Persist.PrivateNodeKey = key.NodePrivate{} p2.Persist.OldPrivateNodeKey = key.NodePrivate{} p2.Persist.NetworkLockKey = key.NLPrivate{} return p2.View() } // Prefs returns a copy of b's current prefs, with any private keys removed. func (b *LocalBackend) Prefs() ipn.PrefsView { b.mu.Lock() defer b.mu.Unlock() return b.sanitizedPrefsLocked() } func (b *LocalBackend) sanitizedPrefsLocked() ipn.PrefsView { return stripKeysFromPrefs(b.pm.CurrentPrefs()) } // Status returns the latest status of the backend and its // sub-components. func (b *LocalBackend) Status() *ipnstate.Status { sb := &ipnstate.StatusBuilder{WantPeers: true} b.UpdateStatus(sb) return sb.Status() } // StatusWithoutPeers is like Status but omits any details // of peers. func (b *LocalBackend) StatusWithoutPeers() *ipnstate.Status { sb := &ipnstate.StatusBuilder{WantPeers: false} b.UpdateStatus(sb) return sb.Status() } // UpdateStatus implements ipnstate.StatusUpdater. func (b *LocalBackend) UpdateStatus(sb *ipnstate.StatusBuilder) { b.e.UpdateStatus(sb) var extraLocked func(*ipnstate.StatusBuilder) if sb.WantPeers { extraLocked = b.populatePeerStatusLocked } b.updateStatus(sb, extraLocked) } // 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.TUN = !wgengine.IsNetstack(b.e) 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 version.IsUnstableBuild() { s.Health = append(s.Health, "This is an unstable (development) version of Tailscale; frequent updates and bugs are likely") } 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 prefs := b.pm.CurrentPrefs(); prefs.Valid() { if !prefs.RouteAll() && b.netMap.AnyPeersAdvertiseRoutes() { s.Health = append(s.Health, healthmsg.WarnAcceptRoutesOff) } if !prefs.ExitNodeID().IsZero() { if exitPeer, ok := b.netMap.PeerWithStableID(prefs.ExitNodeID()); ok { var online = false if exitPeer.Online != nil { online = *exitPeer.Online } s.ExitNodeStatus = &ipnstate.ExitNodeStatus{ ID: prefs.ExitNodeID(), Online: online, TailscaleIPs: exitPeer.Addresses, } } } } } }) sb.MutateSelfStatus(func(ss *ipnstate.PeerStatus) { ss.Online = health.GetInPollNetMap() if b.netMap != nil { ss.InNetworkMap = true ss.HostName = b.netMap.Hostinfo.Hostname ss.DNSName = b.netMap.Name ss.UserID = b.netMap.User if sn := b.netMap.SelfNode; sn != nil { peerStatusFromNode(ss, sn) 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) } exitNodeID := b.pm.CurrentPrefs().ExitNodeID() 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()) } } ps := &ipnstate.PeerStatus{ InNetworkMap: true, UserID: p.User, TailscaleIPs: tailscaleIPs, HostName: p.Hostinfo.Hostname(), DNSName: p.Name, OS: p.Hostinfo.OS(), KeepAlive: p.KeepAlive, LastSeen: lastSeen, Online: p.Online != nil && *p.Online, ShareeNode: p.Hostinfo.ShareeNode(), ExitNode: p.StableID != "" && p.StableID == exitNodeID, SSH_HostKeys: p.Hostinfo.SSH_HostKeys().AsSlice(), } peerStatusFromNode(ps, p) p4, p6 := peerAPIPorts(p) if u := peerAPIURL(nodeIP(p, netip.Addr.Is4), p4); u != "" { ps.PeerAPIURL = append(ps.PeerAPIURL, u) } if u := peerAPIURL(nodeIP(p, netip.Addr.Is6), p6); u != "" { ps.PeerAPIURL = append(ps.PeerAPIURL, u) } sb.AddPeer(p.Key, ps) } } // peerStatusFromNode copies fields that exist in the Node struct for // current node and peers into the provided PeerStatus. func peerStatusFromNode(ps *ipnstate.PeerStatus, n *tailcfg.Node) { ps.ID = n.StableID ps.Created = n.Created ps.ExitNodeOption = tsaddr.ContainsExitRoutes(n.AllowedIPs) if n.Tags != nil { v := views.SliceOf(n.Tags) ps.Tags = &v } if n.PrimaryRoutes != nil { v := views.IPPrefixSliceOf(n.PrimaryRoutes) ps.PrimaryRoutes = &v } if n.Expired { ps.Expired = true } if t := n.KeyExpiry; !t.IsZero() { t = t.Round(time.Second) ps.KeyExpiry = &t } } // 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 } // Track the number of calls currCall := b.numClientStatusCalls.Add(1) b.mu.Lock() // Handle node expiry in the netmap if st.NetMap != nil { now := time.Now() b.em.flagExpiredPeers(st.NetMap, now) // Always stop the existing netmap timer if we have a netmap; // it's possible that we have no nodes expiring, so we should // always cancel the timer and then possibly restart it below. if b.nmExpiryTimer != nil { // Ignore if we can't stop; the atomic check in the // AfterFunc (below) will skip running. b.nmExpiryTimer.Stop() // Nil so we don't attempt to stop on the next netmap b.nmExpiryTimer = nil } // Figure out when the next node in the netmap is expiring so we can // start a timer to reconfigure at that point. nextExpiry := b.em.nextPeerExpiry(st.NetMap, now) if !nextExpiry.IsZero() { tmrDuration := nextExpiry.Sub(now) + 10*time.Second b.nmExpiryTimer = time.AfterFunc(tmrDuration, func() { // Skip if the world has moved on past the // saved call (e.g. if we race stopping this // timer). if b.numClientStatusCalls.Load() != currCall { return } b.logf("setClientStatus: netmap expiry timer triggered after %v", tmrDuration) // Call ourselves with the current status again; the logic in // setClientStatus will take care of updating the expired field // of peers in the netmap. b.setClientStatus(st) }) } } 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{}}) } // Lock b once and do only the things that require locking. b.mu.Lock() if st.LogoutFinished != nil { if p := b.pm.CurrentPrefs(); !p.Persist().Valid() || p.Persist().LoginName() == "" { b.mu.Unlock() return } if err := b.pm.DeleteProfile(b.pm.CurrentProfile().ID); err != nil { b.logf("error deleting profile: %v", err) } if err := b.resetForProfileChangeLockedOnEntry(); err != nil { b.logf("resetForProfileChangeLockedOnEntry err: %v", err) } return } prefsChanged := false prefs := b.pm.CurrentPrefs().AsStruct() 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 && st.Persist.Valid() { if !prefs.Persist.View().Equals(*st.Persist) { prefsChanged = true prefs.Persist = st.Persist.AsStruct() } } 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 !prefs.WantRunning || prefs.LoggedOut { prefsChanged = true } prefs.WantRunning = true prefs.LoggedOut = false } if findExitNodeIDLocked(prefs, st.NetMap) { prefsChanged = true } // Perform all mutations of prefs based on the netmap here. if st.NetMap != nil { if b.updatePersistFromNetMapLocked(st.NetMap, prefs) { prefsChanged = true } } // Prefs will be written out if stale; this is not safe unless locked or cloned. if prefsChanged { if err := b.pm.SetPrefs(prefs.View()); err != nil { b.logf("Failed to save new controlclient state: %v", err) } } // initTKALocked is dependent on CurrentProfile.ID, which is initialized // (for new profiles) on the first call to b.pm.SetPrefs. if err := b.initTKALocked(); err != nil { b.logf("initTKALocked: %v", err) } // Perform all reconfiguration based on the netmap here. if st.NetMap != nil { b.capTailnetLock = hasCapability(st.NetMap, tailcfg.CapabilityTailnetLockAlpha) b.mu.Unlock() // respect locking rules for tkaSyncIfNeeded if err := b.tkaSyncIfNeeded(st.NetMap, prefs.View()); err != nil { b.logf("[v1] TKA sync error: %v", err) } b.mu.Lock() if b.tka != nil { head, err := b.tka.authority.Head().MarshalText() if err != nil { b.logf("[v1] error marshalling tka head: %v", err) } else { b.cc.SetTKAHead(string(head)) } } else { b.cc.SetTKAHead("") } if !envknob.TKASkipSignatureCheck() { b.tkaFilterNetmapLocked(st.NetMap) } b.setNetMapLocked(st.NetMap) b.updateFilterLocked(st.NetMap, prefs.View()) } b.mu.Unlock() // Now complete the lock-free parts of what we started while locked. if prefsChanged { b.send(ipn.Notify{Prefs: ptr.To(prefs.View())}) } if st.NetMap != nil { if envknob.NoLogsNoSupport() && hasCapability(st.NetMap, tailcfg.CapabilityDataPlaneAuditLogs) { msg := "tailnet requires logging to be enabled. Remove --no-logs-no-support from tailscaled command line." health.SetLocalLogConfigHealth(errors.New(msg)) // Connecting to this tailnet without logging is forbidden; boot us outta here. b.mu.Lock() prefs.WantRunning = false p := prefs.View() if err := b.pm.SetPrefs(p); err != nil { b.logf("Failed to save new controlclient state: %v", err) } b.mu.Unlock() b.send(ipn.Notify{ErrMessage: &msg, Prefs: &p}) return } 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 prefs to reference an exit node by ID, rather // than by IP. It returns whether prefs was mutated. func findExitNodeIDLocked(prefs *ipn.Prefs, 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 !prefs.ExitNodeIP.IsValid() { return false } // IP takes precedence over ID, so if both are set, clear ID. if prefs.ExitNodeID != "" { prefs.ExitNodeID = "" prefsChanged = true } for _, peer := range nm.Peers { for _, addr := range peer.Addresses { if !addr.IsSingleIP() || addr.Addr() != prefs.ExitNodeIP { continue } // Found the node being referenced, upgrade prefs to // reference it directly for next time. prefs.ExitNodeID = peer.StableID prefs.ExitNodeIP = netip.Addr{} return true } } return prefsChanged } // 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 && opts.LegacyMigrationPrefs == 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.LegacyMigrationPrefs == nil && !b.pm.CurrentPrefs().Valid() { return errors.New("no prefs provided") } if opts.LegacyMigrationPrefs != nil { b.logf("Start: %v", opts.LegacyMigrationPrefs.Pretty()) } else { b.logf("Start") } b.mu.Lock() if opts.UpdatePrefs != nil { if err := b.checkPrefsLocked(opts.UpdatePrefs); err != nil { b.mu.Unlock() return err } } else if opts.LegacyMigrationPrefs != nil { if err := b.checkPrefsLocked(opts.LegacyMigrationPrefs); err != nil { b.mu.Unlock() return err } } profileID := b.pm.CurrentProfile().ID // 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) && profileID == b.lastProfileID { b.logf("Start: already running; sending notify") nm := b.netMap state := b.state p := b.pm.CurrentPrefs() b.mu.Unlock() b.send(ipn.Notify{ State: &state, NetMap: nm, Prefs: &p, 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.resetControlClientLockedAsync() } 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.migrateStateLocked(opts.LegacyMigrationPrefs); err != nil { b.mu.Unlock() return fmt.Errorf("loading requested state: %v", err) } if opts.UpdatePrefs != nil { oldPrefs := b.pm.CurrentPrefs() newPrefs := opts.UpdatePrefs.Clone() newPrefs.Persist = oldPrefs.Persist().AsStruct() pv := newPrefs.View() if err := b.pm.SetPrefs(pv); err != nil { b.logf("failed to save UpdatePrefs state: %v", err) } b.setAtomicValuesFromPrefsLocked(pv) } prefs := b.pm.CurrentPrefs() wantRunning := prefs.WantRunning() if wantRunning { if err := b.initMachineKeyLocked(); err != nil { return fmt.Errorf("initMachineKeyLocked: %w", err) } } loggedOut := prefs.LoggedOut() serverURL := prefs.ControlURLOrDefault() if inServerMode := prefs.ForceDaemon(); inServerMode || runtime.GOOS == "windows" { b.logf("Start: serverMode=%v", inServerMode) } b.applyPrefsToHostinfoLocked(hostinfo, prefs) b.setNetMapLocked(nil) persistv := prefs.Persist().AsStruct() if persistv == nil { persistv = new(persist.Persist) } b.updateFilterLocked(nil, ipn.PrefsView{}) 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 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(), Logf: logger.WithPrefix(b.logf, "control: "), Persist: *persistv, ServerURL: 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, OnClientVersion: b.onClientVersion, OnControlTime: b.em.onControlTime, 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 if err := b.initTKALocked(); err != nil { b.logf("initTKALocked: %v", err) } var tkaHead string if b.tka != nil { head, err := b.tka.authority.Head().MarshalText() if err != nil { b.mu.Unlock() return fmt.Errorf("marshalling tka head: %w", err) } tkaHead = string(head) } b.mu.Unlock() if endpoints != nil { cc.UpdateEndpoints(endpoints) } cc.SetTKAHead(tkaHead) b.e.SetNetInfoCallback(b.setNetInfo) 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 } var warnInvalidUnsignedNodes = health.NewWarnable() // 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.PrefsView) { // 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.Valid() || 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 packetFilterPermitsUnlockedNodes(netMap.Peers, packetFilter) { err := errors.New("server sent invalid packet filter permitting traffic to unlocked nodes; rejecting all packets for safety") warnInvalidUnsignedNodes.Set(err) packetFilter = nil } else { warnInvalidUnsignedNodes.Set(nil) } } if prefs.Valid() { ar := prefs.AdvertiseRoutes() for i := 0; i < ar.Len(); i++ { r := ar.At(i) 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() } } // packetFilterPermitsUnlockedNodes reports any peer in peers with the // UnsignedPeerAPIOnly bool set true has any of its allowed IPs in the packet // filter. // // If this reports true, the packet filter is invalid (the server is either broken // or malicious) and should be ignored for safety. func packetFilterPermitsUnlockedNodes(peers []*tailcfg.Node, packetFilter []filter.Match) bool { var b netipx.IPSetBuilder var numUnlocked int for _, p := range peers { if !p.UnsignedPeerAPIOnly { continue } numUnlocked++ for _, a := range p.AllowedIPs { // not only addresses! b.AddPrefix(a) } } if numUnlocked == 0 { return false } s, err := b.IPSet() if err != nil { // Shouldn't happen, but if it does, fail closed. return true } for _, m := range packetFilter { for _, r := range m.Srcs { if !s.OverlapsPrefix(r) { continue } if len(m.Dsts) != 0 { return true } } } return false } 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.Updates() 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) } } } // ResendHostinfoIfNeeded is called to recompute the Hostinfo and send // the new version to the control server. func (b *LocalBackend) ResendHostinfoIfNeeded() { hi := hostinfo.New() b.mu.Lock() if b.hostinfo != nil { hi.Services = b.hostinfo.Services } b.hostinfo = hi b.mu.Unlock() b.doSetHostinfoFilterServices(hi) } // WatchNotifications subscribes to the ipn.Notify message bus notification // messages. // // WatchNotifications blocks until ctx is done. // // The provided onWatchAdded, if non-nil, will be called once the watcher // is installed. // // The provided fn will be called for each notification. It will only be // called with non-nil pointers. The caller must not modify roNotify. If // fn returns false, the watch also stops. // // Failure to consume many notifications in a row will result in dropped // notifications. There is currently (2022-11-22) no mechanism provided to // detect when a message has been dropped. func (b *LocalBackend) WatchNotifications(ctx context.Context, mask ipn.NotifyWatchOpt, onWatchAdded func(), fn func(roNotify *ipn.Notify) (keepGoing bool)) { ch := make(chan *ipn.Notify, 128) origFn := fn if mask&ipn.NotifyNoPrivateKeys != 0 { fn = func(n *ipn.Notify) bool { if n.NetMap == nil || n.NetMap.PrivateKey.IsZero() { return origFn(n) } // The netmap in n is shared across all watchers, so to mutate it for a // single watcher we have to clone the notify and the netmap. We can // make shallow clones, at least. nm2 := *n.NetMap n2 := *n n2.NetMap = &nm2 n2.NetMap.PrivateKey = key.NodePrivate{} return origFn(&n2) } } var ini *ipn.Notify b.mu.Lock() const initialBits = ipn.NotifyInitialState | ipn.NotifyInitialPrefs | ipn.NotifyInitialNetMap if mask&initialBits != 0 { ini = &ipn.Notify{Version: version.Long()} if mask&ipn.NotifyInitialState != 0 { ini.State = ptr.To(b.state) if b.state == ipn.NeedsLogin { ini.BrowseToURL = ptr.To(b.authURLSticky) } } if mask&ipn.NotifyInitialPrefs != 0 { ini.Prefs = ptr.To(b.sanitizedPrefsLocked()) } if mask&ipn.NotifyInitialNetMap != 0 { ini.NetMap = b.netMap } } handle := b.notifyWatchers.Add(ch) b.mu.Unlock() defer func() { b.mu.Lock() delete(b.notifyWatchers, handle) b.mu.Unlock() }() if onWatchAdded != nil { onWatchAdded() } if ini != nil { if !fn(ini) { return } } // The GUI clients want to know when peers become active or inactive. // They've historically got this information by polling for it, which is // wasteful. As a step towards making it efficient, they now set this // NotifyWatchEngineUpdates bit to ask for us to send it to them only on // change. That's not yet (as of 2022-11-26) plumbed everywhere in // tailscaled yet, so just do the polling here. This ends up causing all IPN // bus watchers to get the notification every 2 seconds instead of just the // GUI client's bus watcher, but in practice there's only 1 total connection // anyway. And if we're polling, at least the client isn't making a new HTTP // request every 2 seconds. // TODO(bradfitz): plumb this further and only send a Notify on change. if mask&ipn.NotifyWatchEngineUpdates != 0 { ctx, cancel := context.WithCancel(ctx) defer cancel() go b.pollRequestEngineStatus(ctx) } for { select { case <-ctx.Done(): return case n := <-ch: if !fn(n) { return } } } } // pollRequestEngineStatus calls b.RequestEngineStatus every 2 seconds until ctx // is done. func (b *LocalBackend) pollRequestEngineStatus(ctx context.Context) { ticker := time.NewTicker(2 * time.Second) defer ticker.Stop() for { select { case <-ticker.C: b.RequestEngineStatus() case <-ctx.Done(): return } } } // DebugNotify injects a fake notify message to clients. // // It should only be used via the LocalAPI's debug handler. func (b *LocalBackend) DebugNotify(n ipn.Notify) { b.send(n) } // send delivers n to the connected frontend and any API watchers from // LocalBackend.WatchNotifications (via the LocalAPI). // // If no frontend is connected or API watchers are backed up, the notification // is dropped without being delivered. // // If n contains Prefs, those will be sanitized before being delivered. // // b.mu must not be held. func (b *LocalBackend) send(n ipn.Notify) { if n.Prefs != nil { n.Prefs = ptr.To(stripKeysFromPrefs(*n.Prefs)) } if n.Version == "" { n.Version = version.Long() } b.mu.Lock() notifyFunc := b.notify apiSrv := b.peerAPIServer if apiSrv.hasFilesWaiting() { n.FilesWaiting = &empty.Message{} } for _, ch := range b.notifyWatchers { select { case ch <- &n: default: // Drop the notification if the channel is full. } } b.mu.Unlock() if notifyFunc != nil { notifyFunc(n) } } func (b *LocalBackend) sendFileNotify() { var n ipn.Notify b.mu.Lock() for _, wakeWaiter := range b.fileWaiters { wakeWaiter() } 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) } } // validPopBrowserURL reports whether urlStr is a valid value for a // control server to send in a *URL field. // // b.mu must *not* be held. func (b *LocalBackend) validPopBrowserURL(urlStr string) bool { if urlStr == "" { return false } u, err := url.Parse(urlStr) if err != nil { return false } switch u.Scheme { case "https": return true case "http": serverURL := b.Prefs().ControlURLOrDefault() // If the control server is using plain HTTP (likely a dev server), // then permit http://. return strings.HasPrefix(serverURL, "http://") } return false } func (b *LocalBackend) tellClientToBrowseToURL(url string) { if b.validPopBrowserURL(url) { b.send(ipn.Notify{BrowseToURL: &url}) } } // onClientVersion is called on MapResponse updates when a MapResponse contains // a non-nil ClientVersion message. func (b *LocalBackend) onClientVersion(v *tailcfg.ClientVersion) { switch runtime.GOOS { case "darwin", "ios": // These auto-update well enough, and we haven't converted the // ClientVersion types to Swift yet, so don't send them in ipn.Notify // messages. default: // But everything else is a Go client and can deal with this field, even // if they ignore it. b.send(ipn.Notify{ClientVersion: v}) } } // 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 } } // 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 p := b.pm.CurrentPrefs().Persist(); p.Valid() { legacyMachineKey = p.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() { 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 } // clearMachineKeyLocked is called to clear the persisted and in-memory // machine key, so that initMachineKeyLocked (called as part of starting) // generates a new machine key. // // b.mu must be held. func (b *LocalBackend) clearMachineKeyLocked() error { if err := b.store.WriteState(ipn.MachineKeyStateKey, nil); err != nil { return err } b.machinePrivKey = key.MachinePrivate{} b.logf("machine key cleared") return nil } // migrateStateLocked migrates state from the frontend to the backend. // It is a no-op if prefs is nil // b.mu must be held. func (b *LocalBackend) migrateStateLocked(prefs *ipn.Prefs) (err error) { if prefs == nil && !b.pm.CurrentPrefs().Valid() { return fmt.Errorf("no prefs provided and no current profile") } 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.pm.SetPrefs(prefs.View()); err != nil { return fmt.Errorf("store.WriteState: %v", err) } } b.setAtomicValuesFromPrefsLocked(b.pm.CurrentPrefs()) return nil } // setTCPPortsIntercepted populates b.shouldInterceptTCPPortAtomic with an // efficient func for ShouldInterceptTCPPort to use, which is called on every // incoming packet. func (b *LocalBackend) setTCPPortsIntercepted(ports []uint16) { slices.Sort(ports) uniq.ModifySlice(&ports) var f func(uint16) bool switch len(ports) { case 0: f = func(uint16) bool { return false } case 1: f = func(p uint16) bool { return ports[0] == p } case 2: f = func(p uint16) bool { return ports[0] == p || ports[1] == p } case 3: f = func(p uint16) bool { return ports[0] == p || ports[1] == p || ports[2] == p } default: if len(ports) > 16 { m := map[uint16]bool{} for _, p := range ports { m[p] = true } f = func(p uint16) bool { return m[p] } } else { f = func(p uint16) bool { for _, x := range ports { if p == x { return true } } return false } } } b.shouldInterceptTCPPortAtomic.Store(f) } // setAtomicValuesFromPrefsLocked populates sshAtomicBool, containsViaIPFuncAtomic // and shouldInterceptTCPPortAtomic from the prefs p, which may be !Valid(). func (b *LocalBackend) setAtomicValuesFromPrefsLocked(p ipn.PrefsView) { b.sshAtomicBool.Store(p.Valid() && p.RunSSH() && envknob.CanSSHD()) if !p.Valid() { b.containsViaIPFuncAtomic.Store(tsaddr.NewContainsIPFunc(nil)) b.setTCPPortsIntercepted(nil) b.lastServeConfJSON = mem.B(nil) b.serveConfig = ipn.ServeConfigView{} } else { b.containsViaIPFuncAtomic.Store(tsaddr.NewContainsIPFunc(p.AdvertiseRoutes().Filter(tsaddr.IsViaPrefix))) b.setTCPPortsInterceptedFromNetmapAndPrefsLocked(p) } } // 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 } // InServerMode reports whether the Tailscale backend is explicitly running in // "server mode" where it continues to run despite whatever the platform's // default is. In practice, this is only used on Windows, where the default // tailscaled behavior is to shut down whenever the GUI disconnects. // // On non-Windows platforms, this usually returns false (because people don't // set unattended mode on other platforms) and also isn't checked on other // platforms. // // TODO(bradfitz): rename to InWindowsUnattendedMode or something? Or make this // return true on Linux etc and always be called? It's kinda messy now. func (b *LocalBackend) InServerMode() bool { b.mu.Lock() defer b.mu.Unlock() return b.pm.CurrentPrefs().ForceDaemon() } // CheckIPNConnectionAllowed returns an error if the identity in ci should not // be allowed to connect or make requests to the LocalAPI currently. // // Currently (as of 2022-11-23), this is only used on Windows to check if // we started in server mode and ci is from an identity other than the one // that started the server. func (b *LocalBackend) CheckIPNConnectionAllowed(ci *ipnauth.ConnIdentity) error { b.mu.Lock() defer b.mu.Unlock() serverModeUid := b.pm.CurrentUserID() if serverModeUid == "" { // Either this platform isn't a "multi-user" platform or we're not yet // running as one. return nil } if !b.pm.CurrentPrefs().ForceDaemon() { return nil } uid := ci.WindowsUserID() if uid == "" { return errors.New("empty user uid in connection identity") } if uid != serverModeUid { return fmt.Errorf("Tailscale running in server mode (%q); connection from %q not allowed", b.tryLookupUserName(string(serverModeUid)), b.tryLookupUserName(string(uid))) } return nil } // tryLookupUserName tries to look up the username for the uid. // It returns the username on success, or the UID on failure. func (b *LocalBackend) tryLookupUserName(uid string) string { u, err := ipnauth.LookupUserFromID(b.logf, uid) if err != nil { return uid } return u.Username } // Login implements Backend. // As of 2022-11-15, this is only exists for Android. 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) } if peer.Expired { return nil, "", errors.New("peer's node key has expired") } base := peerAPIBase(nm, peer) if base == "" { return nil, "", fmt.Errorf("no PeerAPI 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() p := b.pm.CurrentPrefs() if !p.Valid() || b.netMap == nil { return false // default to safest setting } return !p.ShieldsUp() && b.netMap.CollectServices } // SetCurrentUserID is used to implement support for multi-user systems (only // Windows 2022-11-25). On such systems, the uid is used to determine which // user's state should be used. The current user is maintained by active // connections open to the backend. // // When the backend initially starts it will typically start with no user. Then, // the first connection to the backend from the GUI frontend will set the // current user. Once set, the current user cannot be changed until all previous // connections are closed. The user is also used to determine which // LoginProfiles are accessible. // // In unattended mode, the backend will start with the user which enabled // unattended mode. The user must disable unattended mode before the user can be // changed. // // On non-multi-user systems, the uid should be set to empty string. func (b *LocalBackend) SetCurrentUserID(uid ipn.WindowsUserID) { b.mu.Lock() if b.pm.CurrentUserID() == uid { b.mu.Unlock() return } if err := b.pm.SetCurrentUserID(uid); err != nil { b.mu.Unlock() return } b.resetForProfileChangeLockedOnEntry() } 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.checkProfileNameLocked(p); err != nil { errs = append(errs, err) } if err := b.checkSSHPrefsLocked(p); err != nil { errs = append(errs, err) } if err := b.checkExitNodePrefsLocked(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.") } checkSELinux() // 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.") } case "freebsd", "openbsd": 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 p := b.pm.CurrentPrefs(); !p.Valid() || !p.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 healthmsg.TailscaleSSHOnBut + "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 healthmsg.TailscaleSSHOnBut + "access controls don't allow anyone to access this device. Update your tailnet's ACLs to allow access." } return healthmsg.TailscaleSSHOnBut + "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 { prefs := b.pm.CurrentPrefs() if !prefs.Valid() { return true // assume true until set otherwise } return prefs.ControlURLOrDefault() == ipn.DefaultControlURL } func (b *LocalBackend) checkExitNodePrefsLocked(p *ipn.Prefs) error { if (p.ExitNodeIP.IsValid() || p.ExitNodeID != "") && p.AdvertisesExitNode() { return errors.New("Cannot advertise an exit node and use an exit node at the same time.") } return nil } func (b *LocalBackend) EditPrefs(mp *ipn.MaskedPrefs) (ipn.PrefsView, error) { b.mu.Lock() if mp.EggSet { mp.EggSet = false b.egg = true go b.doSetHostinfoFilterServices(b.hostinfo.Clone()) } p0 := b.pm.CurrentPrefs() p1 := b.pm.CurrentPrefs().AsStruct() p1.ApplyEdits(mp) if err := b.checkPrefsLocked(p1); err != nil { b.mu.Unlock() b.logf("EditPrefs check error: %v", err) return ipn.PrefsView{}, err } if p1.RunSSH && !envknob.CanSSHD() { b.mu.Unlock() b.logf("EditPrefs requests SSH, but disabled by envknob; returning error") return ipn.PrefsView{}, errors.New("Tailscale SSH server administratively disabled.") } if p1.View().Equals(p0) { b.mu.Unlock() return stripKeysFromPrefs(p0), nil } b.logf("EditPrefs: %v", mp.Pretty()) newPrefs := 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. // This should return the public prefs, not the private ones. return stripKeysFromPrefs(newPrefs), nil } func (b *LocalBackend) checkProfileNameLocked(p *ipn.Prefs) error { if p.ProfileName == "" { // It is always okay to clear the profile name. return nil } id := b.pm.ProfileIDForName(p.ProfileName) if id == "" { // No profile with that name exists. That's fine. return nil } if id != b.pm.CurrentProfile().ID { // Name is already in use by another profile. return fmt.Errorf("profile name %q already in use", p.ProfileName) } return 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) } // wantIngressLocked reports whether this node has ingress configured. This bool // is sent to the coordination server (in Hostinfo.WireIngress) as an // optimization hint to know primarily which nodes are NOT using ingress, to // avoid doing work for regular nodes. // // Even if the user's ServeConfig.AllowFunnel map was manually edited in raw // mode and contains map entries with false values, sending true (from Len > 0) // is still fine. This is only an optimization hint for the control plane and // doesn't affect security or correctness. And we also don't expect people to // modify their ServeConfig in raw mode. func (b *LocalBackend) wantIngressLocked() bool { return b.serveConfig.Valid() && b.serveConfig.AllowFunnel().Len() > 0 } // setPrefsLockedOnEntry requires b.mu be held to call it, but it // unlocks b.mu when done. newp ownership passes to this function. // It returns a readonly copy of the new prefs. func (b *LocalBackend) setPrefsLockedOnEntry(caller string, newp *ipn.Prefs) ipn.PrefsView { netMap := b.netMap b.setAtomicValuesFromPrefsLocked(newp.View()) oldp := b.pm.CurrentPrefs() if oldp.Valid() { newp.Persist = oldp.Persist().AsStruct() // caller isn't allowed to override this } // 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. findExitNodeIDLocked(newp, netMap) // We do this to avoid holding the lock while doing everything else. oldHi := b.hostinfo newHi := oldHi.Clone() b.applyPrefsToHostinfoLocked(newHi, newp.View()) b.hostinfo = newHi hostInfoChanged := !oldHi.Equal(newHi) 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.View()) if oldp.ShouldSSHBeRunning() && !newp.ShouldSSHBeRunning() { if b.sshServer != nil { go b.sshServer.Shutdown() b.sshServer = nil } } if netMap != nil { up := netMap.UserProfiles[netMap.User] if login := up.LoginName; login != "" { if newp.Persist == nil { b.logf("active login: %s", login) } else { if newp.Persist.LoginName != login { b.logf("active login: %q (changed from %q)", login, newp.Persist.LoginName) newp.Persist.LoginName = login } newp.Persist.UserProfile = up } } } prefs := newp.View() if err := b.pm.SetPrefs(prefs); err != nil { b.logf("failed to save new controlclient state: %v", err) } b.lastProfileID = b.pm.CurrentProfile().ID b.mu.Unlock() 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: &prefs}) return prefs } // 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", Port: 1}) } 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.pm.CurrentPrefs() 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.PrefsView, 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 := slices.ContainsFunc(nm.Addresses, tsaddr.PrefixIs6) && !slices.ContainsFunc(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 := slices.ContainsFunc(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 an exit node, we send all DNS traffic to the exit node, so // we don't need a fallback resolver. // // However, if the exit node is too old to run a DoH DNS proxy, then we // need to use a fallback resolver as it's very likely the LAN resolvers // will become unreachable. // // 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 } // SetTCPHandlerForFunnelFlow sets the TCP handler for Funnel flows. // It should only be called before the LocalBackend is used. func (b *LocalBackend) SetTCPHandlerForFunnelFlow(h func(src netip.AddrPort, dstPort uint16) (handler func(net.Conn))) { b.getTCPHandlerForFunnelFlow = h } // 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 } // SetLogFlusher sets a func to be called to flush log uploads. // // It should only be called before the LocalBackend is used. func (b *LocalBackend) SetLogFlusher(flushFunc func()) { b.logFlushFunc = flushFunc } // TryFlushLogs calls the log flush function. It returns false if a log flush // function was never initialized with SetLogFlusher. // // TryFlushLogs should not block. func (b *LocalBackend) TryFlushLogs() bool { if b.logFlushFunc == nil { return false } b.logFlushFunc() return true } // 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 PeerAPI listeners // and clears out the PeerAPI 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, 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(logf logger.Logf, 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) // Ensure that we're only accepting properly-masked // prefixes; the control server should be masking // these, so if we get them, skip. if mm := aip.Masked(); aip != mm { // To avoid a DoS where a peer could cause all // reconfigs to fail by sending a bad prefix, we just // skip, but don't error, on an unmasked route. logf("advertised route %s from %s has non-address bits set; expected %s", aip, peer.PublicKey.ShortString(), mm) continue } // 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...) } tsaddr.SortPrefixes(routes) return routes } // routerConfig produces a router.Config from a wireguard config and IPN prefs. func (b *LocalBackend) routerConfig(cfg *wgcfg.Config, prefs ipn.PrefsView, oneCGNATRoute bool) *router.Config { singleRouteThreshold := 10_000 if oneCGNATRoute { singleRouteThreshold = 1 } rs := &router.Config{ LocalAddrs: unmapIPPrefixes(cfg.Addresses), SubnetRoutes: unmapIPPrefixes(prefs.AdvertiseRoutes().AsSlice()), SNATSubnetRoutes: !prefs.NoSNAT(), NetfilterMode: prefs.NetfilterMode(), Routes: peerRoutes(b.logf, 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 slices.ContainsFunc(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 } // b.mu must be held. func (b *LocalBackend) applyPrefsToHostinfoLocked(hi *tailcfg.Hostinfo, prefs ipn.PrefsView) { if h := prefs.Hostname(); h != "" { hi.Hostname = h } hi.RoutableIPs = prefs.AdvertiseRoutes().AsSlice() hi.RequestTags = prefs.AdvertiseTags().AsSlice() 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 // The Hostinfo.WantIngress field tells control whether this node wants to // be wired up for ingress connections. If harmless if it's accidentally // true; the actual policy is controlled in tailscaled by ServeConfig. But // if this is accidentally false, then control may not configure DNS // properly. This exists as an optimization to control to program fewer DNS // records that have ingress enabled but are not actually being used. hi.WireIngress = b.wantIngressLocked() } // 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() b.enterStateLockedOnEntry(newState) } // enterStateLockedOnEntry is like enterState but requires b.mu be held to call // it, but it unlocks b.mu when done. func (b *LocalBackend) enterStateLockedOnEntry(newState ipn.State) { oldState := b.state b.state = newState prefs := b.pm.CurrentPrefs() 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.Valid() && 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, " ")) case ipn.NoState: // Do nothing. 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() defer b.mu.Unlock() p := b.pm.CurrentPrefs() return p.Valid() && p.Persist().Valid() && !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() var ( cc = b.cc netMap = b.netMap state = b.state blocked = b.blocked st = b.engineStatus keyExpired = b.keyExpired wantRunning = false loggedOut = false ) if p := b.pm.CurrentPrefs(); p.Valid() { wantRunning = p.WantRunning() loggedOut = p.LoggedOut() } b.mu.Unlock() switch { case !wantRunning && !loggedOut && !blocked && b.hasNodeKey(): return ipn.Stopped case netMap == nil: if (cc != nil && 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() } // resetControlClientLockedAsync sets b.cc to nil, and starts a // goroutine to Shutdown the old client. It does not wait for the // shutdown to complete. func (b *LocalBackend) resetControlClientLockedAsync() { if b.cc == nil { return } // When we clear the control client, stop any outstanding netmap expiry // timer; synthesizing a new netmap while we don't have a control // client will break things. // // See https://github.com/tailscale/tailscale/issues/7392 if b.nmExpiryTimer != nil { b.nmExpiryTimer.Stop() b.nmExpiryTimer = nil // Also bump the epoch to ensure that if the timer started, it // will abort. b.numClientStatusCalls.Add(1) } go b.cc.Shutdown() b.cc = nil b.ccAuto = nil } // 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") b.resetControlClientLockedAsync() b.setNetMapLocked(nil) b.pm.Reset() b.keyExpired = false b.authURL = "" b.authURLSticky = "" b.activeLogin = "" b.setAtomicValuesFromPrefsLocked(ipn.PrefsView{}) } 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) updatePersistFromNetMapLocked(nm *netmap.NetworkMap, prefs *ipn.Prefs) (changed bool) { if nm == nil || nm.SelfNode == nil { return } up := nm.UserProfiles[nm.User] if prefs.Persist.UserProfile.ID != up.ID { // If the current profile doesn't match the // network map's user profile, then we need to // update the persisted UserProfile to match. prefs.Persist.UserProfile = up changed = true } if prefs.Persist.NodeID == "" { // If the current profile doesn't have a NodeID, // then we need to update the persisted NodeID to // match. prefs.Persist.NodeID = nm.SelfNode.StableID changed = true } return changed } 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 = "" } } 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 b.setDebugLogsByCapabilityLocked(nm) // See the netns package for documentation on what this capability does. netns.SetBindToInterfaceByRoute(hasCapability(nm, tailcfg.CapabilityBindToInterfaceByRoute)) netns.SetDisableBindConnToInterface(hasCapability(nm, tailcfg.CapabilityDebugDisableBindConnToInterface)) b.setTCPPortsInterceptedFromNetmapAndPrefsLocked(b.pm.CurrentPrefs()) 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) } } } // setDebugLogsByCapabilityLocked sets debug logging based on the self node's // capabilities in the provided NetMap. func (b *LocalBackend) setDebugLogsByCapabilityLocked(nm *netmap.NetworkMap) { // These are sufficiently cheap (atomic bools) that we don't need to // store state and compare. if hasCapability(nm, tailcfg.CapabilityDebugTSDNSResolution) { dnscache.SetDebugLoggingEnabled(true) } else { dnscache.SetDebugLoggingEnabled(false) } } func (b *LocalBackend) reloadServeConfigLocked(prefs ipn.PrefsView) { if b.netMap == nil || b.netMap.SelfNode == nil || !prefs.Valid() || b.pm.CurrentProfile().ID == "" { // We're not logged in, so we don't have a profile. // Don't try to load the serve config. b.lastServeConfJSON = mem.B(nil) b.serveConfig = ipn.ServeConfigView{} return } confKey := ipn.ServeConfigKey(b.pm.CurrentProfile().ID) // TODO(maisem,bradfitz): prevent reading the config from disk // if the profile has not changed. confj, err := b.store.ReadState(confKey) if err != nil { b.lastServeConfJSON = mem.B(nil) b.serveConfig = ipn.ServeConfigView{} return } if b.lastServeConfJSON.Equal(mem.B(confj)) { return } b.lastServeConfJSON = mem.B(confj) var conf ipn.ServeConfig if err := json.Unmarshal(confj, &conf); err != nil { b.logf("invalid ServeConfig %q in StateStore: %v", confKey, err) b.serveConfig = ipn.ServeConfigView{} return } b.serveConfig = conf.View() } // setTCPPortsInterceptedFromNetmapAndPrefsLocked calls setTCPPortsIntercepted with // the ports that tailscaled should handle as a function of b.netMap and b.prefs. // // b.mu must be held. func (b *LocalBackend) setTCPPortsInterceptedFromNetmapAndPrefsLocked(prefs ipn.PrefsView) { handlePorts := make([]uint16, 0, 4) if prefs.Valid() && prefs.RunSSH() && envknob.CanSSHD() { handlePorts = append(handlePorts, 22) } b.reloadServeConfigLocked(prefs) if b.serveConfig.Valid() { servePorts := make([]uint16, 0, 3) b.serveConfig.TCP().Range(func(port uint16, _ ipn.TCPPortHandlerView) bool { if port > 0 { servePorts = append(servePorts, uint16(port)) } return true }) handlePorts = append(handlePorts, servePorts...) b.setServeProxyHandlersLocked() // don't listen on netmap addresses if we're in userspace mode if !wgengine.IsNetstack(b.e) { b.updateServeTCPPortNetMapAddrListenersLocked(servePorts) } } // Kick off a Hostinfo update to control if WireIngress changed. if wire := b.wantIngressLocked(); b.hostinfo != nil && b.hostinfo.WireIngress != wire { b.logf("Hostinfo.WireIngress changed to %v", wire) b.hostinfo.WireIngress = wire go b.doSetHostinfoFilterServices(b.hostinfo.Clone()) } b.setTCPPortsIntercepted(handlePorts) } // setServeProxyHandlersLocked ensures there is an http proxy handler for each // backend specified in serveConfig. It expects serveConfig to be valid and // up-to-date, so should be called after reloadServeConfigLocked. func (b *LocalBackend) setServeProxyHandlersLocked() { if !b.serveConfig.Valid() { return } var backends map[string]bool b.serveConfig.Web().Range(func(_ ipn.HostPort, conf ipn.WebServerConfigView) (cont bool) { conf.Handlers().Range(func(_ string, h ipn.HTTPHandlerView) (cont bool) { backend := h.Proxy() mak.Set(&backends, backend, true) if _, ok := b.serveProxyHandlers.Load(backend); ok { return true } b.logf("serve: creating a new proxy handler for %s", backend) p, err := b.proxyHandlerForBackend(backend) if err != nil { // The backend endpoint (h.Proxy) should have been validated by expandProxyTarget // in the CLI, so just log the error here. b.logf("[unexpected] could not create proxy for %v: %s", backend, err) return true } b.serveProxyHandlers.Store(backend, p) return true }) return true }) // Clean up handlers for proxy backends that are no longer present // in configuration. b.serveProxyHandlers.Range(func(key, value any) bool { backend := key.(string) if !backends[backend] { b.logf("serve: closing idle connections to %s", backend) value.(*httputil.ReverseProxy).Transport.(*http.Transport).CloseIdleConnections() b.serveProxyHandlers.Delete(backend) } return true }) } // 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() prefs := b.pm.CurrentPrefs() if !prefs.Valid() { return "" } return 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 { opUserName := b.operatorUserName() 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() machinePrivKey := b.machinePrivKey prefs := b.pm.CurrentPrefs() b.mu.Unlock() if !prefs.Valid() || machinePrivKey.IsZero() { return } mk := machinePrivKey.Public() nk := prefs.Persist().PublicNodeKey() return mk, nk } func (b *LocalBackend) removeFileWaiter(handle set.Handle) { b.mu.Lock() defer b.mu.Unlock() delete(b.fileWaiters, handle) } func (b *LocalBackend) addFileWaiter(wakeWaiter context.CancelFunc) set.Handle { b.mu.Lock() defer b.mu.Unlock() return b.fileWaiters.Add(wakeWaiter) } func (b *LocalBackend) WaitingFiles() ([]apitype.WaitingFile, error) { b.mu.Lock() apiSrv := b.peerAPIServer b.mu.Unlock() return apiSrv.WaitingFiles() } // AwaitWaitingFiles is like WaitingFiles but blocks while ctx is not done, // waiting for any files to be available. // // On return, exactly one of the results will be non-empty or non-nil, // respectively. func (b *LocalBackend) AwaitWaitingFiles(ctx context.Context) ([]apitype.WaitingFile, error) { if ff, err := b.WaitingFiles(); err != nil || len(ff) > 0 { return ff, err } for { gotFile, gotFileCancel := context.WithCancel(context.Background()) defer gotFileCancel() handle := b.addFileWaiter(gotFileCancel) defer b.removeFileWaiter(handle) // Now that we've registered ourselves, check again, in case // of race. Otherwise there's a small window where we could // miss a file arrival and wait forever. if ff, err := b.WaitingFiles(); err != nil || len(ff) > 0 { return ff, err } select { case <-gotFile.Done(): if ff, err := b.WaitingFiles(); err != nil || len(ff) > 0 { return ff, err } case <-ctx.Done(): return nil, ctx.Err() } } } 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.pm.CurrentPrefs(); prefs.Valid() && prefs.Persist().Valid() { 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) } } func peerAPIPorts(peer *tailcfg.Node) (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 } } return } // peerAPIURL returns an HTTP URL for the peer's peerapi service, // without a trailing slash. // // If ip or port is the zero value then it returns the empty string. func peerAPIURL(ip netip.Addr, port uint16) string { if port == 0 || !ip.IsValid() { return "" } return fmt.Sprintf("http://%v", netip.AddrPortFrom(ip, port)) } // 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 } } p4, p6 := peerAPIPorts(peer) switch { case have4 && p4 != 0: return peerAPIURL(nodeIP(peer, netip.Addr.Is4), p4) case have6 && p6 != 0: return peerAPIURL(nodeIP(peer, netip.Addr.Is6), p6) } return "" } 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.pm.CurrentPrefs().Valid() { return false } var def4, def6 bool ar := b.pm.CurrentPrefs().AdvertiseRoutes() for i := 0; i < ar.Len(); i++ { r := ar.At(i) 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 && peerCanProxyDNS(p) { return peerAPIBase(nm, p) + "/dns-query", true } } return "", false } func peerCanProxyDNS(p *tailcfg.Node) bool { if p.Cap >= 26 { // Actually added at 25 // (https://github.com/tailscale/tailscale/blob/3ae6f898cfdb58fd0e30937147dd6ce28c6808dd/tailcfg/tailcfg.go#L51) // so anything >= 26 can do it. return true } // If p.Cap is not populated (e.g. older control server), then do the old // thing of searching through services. 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 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 } type keyProvingNoiseRoundTripper struct { b *LocalBackend } func (n keyProvingNoiseRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) { b := n.b var priv key.NodePrivate b.mu.Lock() cc := b.ccAuto if nm := b.netMap; nm != nil { priv = nm.PrivateKey } b.mu.Unlock() if cc == nil { return nil, errors.New("no client") } if priv.IsZero() { return nil, errors.New("no netmap or private key") } rt, ep, err := cc.GetSingleUseNoiseRoundTripper(req.Context()) if err != nil { return nil, err } if ep == nil || ep.NodeKeyChallenge.IsZero() { go rt.RoundTrip(new(http.Request)) // return our reservation with a bogus request return nil, errors.New("this coordination server does not support API calls over the Noise channel") } // QueryEscape the node key since it has a colon in it. nk := url.QueryEscape(priv.Public().String()) req.SetBasicAuth(nk, "") // genNodeProofHeaderValue returns the Tailscale-Node-Proof header's value to prove // to chalPub that we control claimedPrivate. genNodeProofHeaderValue := func(claimedPrivate key.NodePrivate, chalPub key.ChallengePublic) string { // TODO(bradfitz): cache this somewhere? box := claimedPrivate.SealToChallenge(chalPub, []byte(chalPub.String())) return claimedPrivate.Public().String() + " " + base64.StdEncoding.EncodeToString(box) } // And prove we have the private key corresponding to the public key sent // tin the basic auth username. req.Header.Set("Tailscale-Node-Proof", genNodeProofHeaderValue(priv, ep.NodeKeyChallenge)) return rt.RoundTrip(req) } // KeyProvingNoiseRoundTripper returns an http.RoundTripper that uses the LocalBackend's // DoNoiseRequest method and mutates the request to add an authorization header // to prove the client's nodekey. func (b *LocalBackend) KeyProvingNoiseRoundTripper() http.RoundTripper { return keyProvingNoiseRoundTripper{b} } // 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() p := b.pm.CurrentPrefs() return p.Valid() && p.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 } var warnSSHSELinux = health.NewWarnable() func checkSELinux() { if runtime.GOOS != "linux" { return } out, _ := exec.Command("getenforce").Output() if string(bytes.TrimSpace(out)) == "Enforcing" { warnSSHSELinux.Set(errors.New("SELinux is enabled; Tailscale SSH may not work. See https://tailscale.com/s/ssh-selinux")) } else { warnSSHSELinux.Set(nil) } } func (b *LocalBackend) HandleSSHConn(c net.Conn) (err error) { s, err := b.sshServerOrInit() if err != nil { return err } checkSELinux() 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 validQuad100Host(h string) bool { switch h { case "", tsaddr.TailscaleServiceIPString, tsaddr.TailscaleServiceIPv6String, "[" + tsaddr.TailscaleServiceIPv6String + "]": return true } return false } 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 } if !validQuad100Host(r.Host) { http.Error(w, "bad request", http.StatusBadRequest) return } b.mu.Lock() defer b.mu.Unlock() io.WriteString(w, "

Tailscale

\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, "

Local addresses:

\n") } func (b *LocalBackend) Doctor(ctx context.Context, logf logger.Logf) { // We can write logs too fast for logtail to handle, even when // opting-out of rate limits. Limit ourselves to at most one message // per 20ms and a burst of 60 log lines, which should be fast enough to // not block for too long but slow enough that we can upload all lines. logf = logger.SlowLoggerWithClock(ctx, logf, 20*time.Millisecond, 60, time.Now) var checks []doctor.Check checks = append(checks, routetable.Check{}) // Print a log message if any of the global DNS resolvers are Tailscale // IPs; this can interfere with our ability to connect to the Tailscale // controlplane. checks = append(checks, doctor.CheckFunc("dns-resolvers", func(_ context.Context, logf logger.Logf) error { b.mu.Lock() nm := b.netMap b.mu.Unlock() if nm == nil { return nil } for i, resolver := range nm.DNS.Resolvers { ipp, ok := resolver.IPPort() if ok && tsaddr.IsTailscaleIP(ipp.Addr()) { logf("resolver %d is a Tailscale address: %v", i, resolver) } } for i, resolver := range nm.DNS.FallbackResolvers { ipp, ok := resolver.IPPort() if ok && tsaddr.IsTailscaleIP(ipp.Addr()) { logf("fallback resolver %d is a Tailscale address: %v", i, resolver) } } return nil })) // 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...) } // SetDevStateStore updates the LocalBackend's state storage to the provided values. // // It's meant only for development. func (b *LocalBackend) SetDevStateStore(key, value string) error { if b.store == nil { return errors.New("no state store") } err := b.store.WriteState(ipn.StateKey(key), []byte(value)) b.logf("SetDevStateStore(%q, %q) = %v", key, value, err) if err != nil { return err } b.mu.Lock() defer b.mu.Unlock() b.setTCPPortsInterceptedFromNetmapAndPrefsLocked(b.pm.CurrentPrefs()) return nil } // ShouldInterceptTCPPort reports whether the given TCP port number to a // Tailscale IP (not a subnet router, service IP, etc) should be intercepted by // Tailscaled and handled in-process. func (b *LocalBackend) ShouldInterceptTCPPort(port uint16) bool { return b.shouldInterceptTCPPortAtomic.Load()(port) } // SwitchProfile switches to the profile with the given id. // It will restart the backend on success. // If the profile is not known, it returns an errProfileNotFound. func (b *LocalBackend) SwitchProfile(profile ipn.ProfileID) error { if b.CurrentProfile().ID == profile { return nil } b.mu.Lock() if err := b.pm.SwitchProfile(profile); err != nil { b.mu.Unlock() return err } return b.resetForProfileChangeLockedOnEntry() } func (b *LocalBackend) initTKALocked() error { cp := b.pm.CurrentProfile() if cp.ID == "" { b.tka = nil return nil } if b.tka != nil { if b.tka.profile == cp.ID { // Already initialized. return nil } // As we're switching profiles, we need to reset the TKA to nil. b.tka = nil } root := b.TailscaleVarRoot() if root == "" { b.tka = nil b.logf("network-lock unavailable; no state directory") return nil } chonkDir := b.chonkPathLocked() if _, err := os.Stat(chonkDir); err == nil { // The directory exists, which means network-lock has been initialized. storage, err := tka.ChonkDir(chonkDir) if err != nil { return fmt.Errorf("opening tailchonk: %v", err) } authority, err := tka.Open(storage) if err != nil { return fmt.Errorf("initializing tka: %v", err) } if err := authority.Compact(storage, tkaCompactionDefaults); err != nil { b.logf("tka compaction failed: %v", err) } b.tka = &tkaState{ profile: cp.ID, authority: authority, storage: storage, } b.logf("tka initialized at head %x", authority.Head()) } return nil } // resetForProfileChangeLockedOnEntry resets the backend for a profile change. func (b *LocalBackend) resetForProfileChangeLockedOnEntry() error { b.setNetMapLocked(nil) // Reset netmap. // Reset the NetworkMap in the engine b.e.SetNetworkMap(new(netmap.NetworkMap)) if err := b.initTKALocked(); err != nil { return err } b.lastServeConfJSON = mem.B(nil) b.serveConfig = ipn.ServeConfigView{} b.enterStateLockedOnEntry(ipn.NoState) // Reset state. health.SetLocalLogConfigHealth(nil) return b.Start(ipn.Options{}) } // DeleteProfile deletes a profile with the given ID. // If the profile is not known, it is a no-op. func (b *LocalBackend) DeleteProfile(p ipn.ProfileID) error { b.mu.Lock() defer b.mu.Unlock() needToRestart := b.pm.CurrentProfile().ID == p if err := b.pm.DeleteProfile(p); err != nil { if err == errProfileNotFound { return nil } return err } if !needToRestart { return nil } return b.resetForProfileChangeLockedOnEntry() } // CurrentProfile returns the current LoginProfile. // The value may be zero if the profile is not persisted. func (b *LocalBackend) CurrentProfile() ipn.LoginProfile { b.mu.Lock() defer b.mu.Unlock() return b.pm.CurrentProfile() } // NewProfile creates and switches to the new profile. func (b *LocalBackend) NewProfile() error { b.mu.Lock() b.pm.NewProfile() return b.resetForProfileChangeLockedOnEntry() } // ListProfiles returns a list of all LoginProfiles. func (b *LocalBackend) ListProfiles() []ipn.LoginProfile { b.mu.Lock() defer b.mu.Unlock() return b.pm.Profiles() } // ResetAuth resets the authentication state, including persisted keys. Also // has the side effect of removing all profiles and reseting preferences. The // backend is left with a new profile, ready for StartLoginInterative to be // called to register it as new node. func (b *LocalBackend) ResetAuth() error { b.mu.Lock() b.resetControlClientLockedAsync() if err := b.clearMachineKeyLocked(); err != nil { b.mu.Unlock() return err } if err := b.pm.DeleteAllProfiles(); err != nil { b.mu.Unlock() return err } return b.resetForProfileChangeLockedOnEntry() } // StreamDebugCapture writes a pcap stream of packets traversing // tailscaled to the provided response writer. func (b *LocalBackend) StreamDebugCapture(ctx context.Context, w io.Writer) error { var s *capture.Sink b.mu.Lock() if b.debugSink == nil { s = capture.New() b.debugSink = s b.e.InstallCaptureHook(s.LogPacket) } else { s = b.debugSink } b.mu.Unlock() unregister := s.RegisterOutput(w) select { case <-ctx.Done(): case <-s.WaitCh(): } unregister() // Shut down & uninstall the sink if there are no longer // any outputs on it. b.mu.Lock() defer b.mu.Unlock() select { case <-b.ctx.Done(): return nil default: } if b.debugSink != nil && b.debugSink.NumOutputs() == 0 { s := b.debugSink b.e.InstallCaptureHook(nil) b.debugSink = nil return s.Close() } return nil } func (b *LocalBackend) GetPeerEndpointChanges(ctx context.Context, ip netip.Addr) ([]magicsock.EndpointChange, error) { pip, ok := b.e.PeerForIP(ip) if !ok { return nil, fmt.Errorf("no matching peer") } if pip.IsSelf { return nil, fmt.Errorf("%v is local Tailscale IP", ip) } peer := pip.Node mc, err := b.magicConn() if err != nil { return nil, fmt.Errorf("getting magicsock conn: %w", err) } chs, err := mc.GetEndpointChanges(peer) if err != nil { return nil, fmt.Errorf("getting endpoint changes: %w", err) } return chs, nil }