// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package controlclient import ( "bytes" "context" "crypto/rand" "encoding/binary" "encoding/json" "errors" "flag" "fmt" "io" "io/ioutil" "log" "net/http" "net/url" "os" "os/exec" "path/filepath" "reflect" "runtime" "strconv" "strings" "sync" "sync/atomic" "time" "golang.org/x/crypto/nacl/box" "inet.af/netaddr" "tailscale.com/health" "tailscale.com/log/logheap" "tailscale.com/net/dnscache" "tailscale.com/net/dnsfallback" "tailscale.com/net/interfaces" "tailscale.com/net/netns" "tailscale.com/net/tlsdial" "tailscale.com/net/tshttpproxy" "tailscale.com/tailcfg" "tailscale.com/types/logger" "tailscale.com/types/netmap" "tailscale.com/types/opt" "tailscale.com/types/persist" "tailscale.com/types/wgkey" "tailscale.com/util/dnsname" "tailscale.com/util/systemd" "tailscale.com/version" "tailscale.com/wgengine/monitor" ) // Direct is the client that connects to a tailcontrol server for a node. type Direct struct { httpc *http.Client // HTTP client used to talk to tailcontrol serverURL string // URL of the tailcontrol server timeNow func() time.Time lastPrintMap time.Time newDecompressor func() (Decompressor, error) keepAlive bool logf logger.Logf linkMon *monitor.Mon // or nil discoPubKey tailcfg.DiscoKey getMachinePrivKey func() (wgkey.Private, error) debugFlags []string keepSharerAndUserSplit bool skipIPForwardingCheck bool mu sync.Mutex // mutex guards the following fields serverKey wgkey.Key persist persist.Persist authKey string tryingNewKey wgkey.Private expiry *time.Time // hostinfo is mutated in-place while mu is held. hostinfo *tailcfg.Hostinfo // always non-nil endpoints []tailcfg.Endpoint everEndpoints bool // whether we've ever had non-empty endpoints localPort uint16 // or zero to mean auto } type Options struct { Persist persist.Persist // initial persistent data GetMachinePrivateKey func() (wgkey.Private, error) // returns the machine key to use ServerURL string // URL of the tailcontrol server AuthKey string // optional node auth key for auto registration TimeNow func() time.Time // time.Now implementation used by Client Hostinfo *tailcfg.Hostinfo // non-nil passes ownership, nil means to use default using os.Hostname, etc DiscoPublicKey tailcfg.DiscoKey NewDecompressor func() (Decompressor, error) KeepAlive bool Logf logger.Logf HTTPTestClient *http.Client // optional HTTP client to use (for tests only) DebugFlags []string // debug settings to send to control LinkMonitor *monitor.Mon // optional link monitor // KeepSharerAndUserSplit controls whether the client // understands Node.Sharer. If false, the Sharer is mapped to the User. KeepSharerAndUserSplit bool // SkipIPForwardingCheck declares that the host's IP // forwarding works and should not be double-checked by the // controlclient package. SkipIPForwardingCheck bool } type Decompressor interface { DecodeAll(input, dst []byte) ([]byte, error) Close() } // NewDirect returns a new Direct client. func NewDirect(opts Options) (*Direct, error) { if opts.ServerURL == "" { return nil, errors.New("controlclient.New: no server URL specified") } if opts.GetMachinePrivateKey == nil { return nil, errors.New("controlclient.New: no GetMachinePrivateKey specified") } opts.ServerURL = strings.TrimRight(opts.ServerURL, "/") serverURL, err := url.Parse(opts.ServerURL) if err != nil { return nil, err } if opts.TimeNow == nil { opts.TimeNow = time.Now } if opts.Logf == nil { // TODO(apenwarr): remove this default and fail instead. // TODO(bradfitz): ... but then it shouldn't be in Options. opts.Logf = log.Printf } httpc := opts.HTTPTestClient if httpc == nil { dnsCache := &dnscache.Resolver{ Forward: dnscache.Get().Forward, // use default cache's forwarder UseLastGood: true, LookupIPFallback: dnsfallback.Lookup, } dialer := netns.NewDialer() tr := http.DefaultTransport.(*http.Transport).Clone() tr.Proxy = tshttpproxy.ProxyFromEnvironment tshttpproxy.SetTransportGetProxyConnectHeader(tr) tr.TLSClientConfig = tlsdial.Config(serverURL.Hostname(), tr.TLSClientConfig) tr.DialContext = dnscache.Dialer(dialer.DialContext, dnsCache) tr.DialTLSContext = dnscache.TLSDialer(dialer.DialContext, dnsCache, tr.TLSClientConfig) tr.ForceAttemptHTTP2 = true httpc = &http.Client{Transport: tr} } c := &Direct{ httpc: httpc, getMachinePrivKey: opts.GetMachinePrivateKey, serverURL: opts.ServerURL, timeNow: opts.TimeNow, logf: opts.Logf, newDecompressor: opts.NewDecompressor, keepAlive: opts.KeepAlive, persist: opts.Persist, authKey: opts.AuthKey, discoPubKey: opts.DiscoPublicKey, debugFlags: opts.DebugFlags, keepSharerAndUserSplit: opts.KeepSharerAndUserSplit, linkMon: opts.LinkMonitor, skipIPForwardingCheck: opts.SkipIPForwardingCheck, } if opts.Hostinfo == nil { c.SetHostinfo(NewHostinfo()) } else { c.SetHostinfo(opts.Hostinfo) } return c, nil } var osVersion func() string // non-nil on some platforms func NewHostinfo() *tailcfg.Hostinfo { hostname, _ := os.Hostname() hostname = dnsname.FirstLabel(hostname) var osv string if osVersion != nil { osv = osVersion() } return &tailcfg.Hostinfo{ IPNVersion: version.Long, Hostname: hostname, OS: version.OS(), OSVersion: osv, Package: packageType(), GoArch: runtime.GOARCH, } } func packageType() string { switch runtime.GOOS { case "windows": if _, err := os.Stat(`C:\ProgramData\chocolatey\lib\tailscale`); err == nil { return "choco" } case "darwin": // Using tailscaled or IPNExtension? exe, _ := os.Executable() return filepath.Base(exe) } return "" } // SetHostinfo clones the provided Hostinfo and remembers it for the // next update. It reports whether the Hostinfo has changed. func (c *Direct) SetHostinfo(hi *tailcfg.Hostinfo) bool { if hi == nil { panic("nil Hostinfo") } c.mu.Lock() defer c.mu.Unlock() if hi.Equal(c.hostinfo) { return false } c.hostinfo = hi.Clone() j, _ := json.Marshal(c.hostinfo) c.logf("HostInfo: %s", j) return true } // SetNetInfo clones the provided NetInfo and remembers it for the // next update. It reports whether the NetInfo has changed. func (c *Direct) SetNetInfo(ni *tailcfg.NetInfo) bool { if ni == nil { panic("nil NetInfo") } c.mu.Lock() defer c.mu.Unlock() if c.hostinfo == nil { c.logf("[unexpected] SetNetInfo called with no HostInfo; ignoring NetInfo update: %+v", ni) return false } if reflect.DeepEqual(ni, c.hostinfo.NetInfo) { return false } c.hostinfo.NetInfo = ni.Clone() return true } func (c *Direct) GetPersist() persist.Persist { c.mu.Lock() defer c.mu.Unlock() return c.persist } func (c *Direct) TryLogout(ctx context.Context) error { c.logf("direct.TryLogout()") mustRegen, newURL, err := c.doLogin(ctx, loginOpt{Logout: true}) c.logf("TryLogout control response: mustRegen=%v, newURL=%v, err=%v", mustRegen, newURL, err) c.mu.Lock() c.persist = persist.Persist{} c.mu.Unlock() return err } func (c *Direct) TryLogin(ctx context.Context, t *tailcfg.Oauth2Token, flags LoginFlags) (url string, err error) { c.logf("direct.TryLogin(token=%v, flags=%v)", t != nil, flags) return c.doLoginOrRegen(ctx, loginOpt{Token: t, Flags: flags}) } // WaitLoginURL sits in a long poll waiting for the user to authenticate at url. // // On success, newURL and err will both be nil. func (c *Direct) WaitLoginURL(ctx context.Context, url string) (newURL string, err error) { c.logf("direct.WaitLoginURL") return c.doLoginOrRegen(ctx, loginOpt{URL: url}) } func (c *Direct) doLoginOrRegen(ctx context.Context, opt loginOpt) (newURL string, err error) { mustRegen, url, err := c.doLogin(ctx, opt) if err != nil { return url, err } if mustRegen { opt.Regen = true _, url, err = c.doLogin(ctx, opt) } return url, err } type loginOpt struct { Token *tailcfg.Oauth2Token Flags LoginFlags Regen bool URL string Logout bool } func (c *Direct) doLogin(ctx context.Context, opt loginOpt) (mustRegen bool, newURL string, err error) { c.mu.Lock() persist := c.persist tryingNewKey := c.tryingNewKey serverKey := c.serverKey authKey := c.authKey hostinfo := c.hostinfo.Clone() backendLogID := hostinfo.BackendLogID expired := c.expiry != nil && !c.expiry.IsZero() && c.expiry.Before(c.timeNow()) c.mu.Unlock() machinePrivKey, err := c.getMachinePrivKey() if err != nil { return false, "", fmt.Errorf("getMachinePrivKey: %w", err) } if machinePrivKey.IsZero() { return false, "", errors.New("getMachinePrivKey returned zero key") } regen := opt.Regen if opt.Logout { c.logf("logging out...") } else { if expired { c.logf("Old key expired -> regen=true") systemd.Status("key expired; run 'tailscale up' to authenticate") regen = true } if (opt.Flags & LoginInteractive) != 0 { c.logf("LoginInteractive -> regen=true") regen = true } } c.logf("doLogin(regen=%v, hasUrl=%v)", regen, opt.URL != "") if serverKey.IsZero() { var err error serverKey, err = loadServerKey(ctx, c.httpc, c.serverURL) if err != nil { return regen, opt.URL, err } c.mu.Lock() c.serverKey = serverKey c.mu.Unlock() } var oldNodeKey wgkey.Key switch { case opt.Logout: tryingNewKey = persist.PrivateNodeKey case opt.URL != "": // Nothing. case regen || persist.PrivateNodeKey.IsZero(): c.logf("Generating a new nodekey.") persist.OldPrivateNodeKey = persist.PrivateNodeKey key, err := wgkey.NewPrivate() if err != nil { c.logf("login keygen: %v", err) return regen, opt.URL, err } tryingNewKey = key default: // Try refreshing the current key first tryingNewKey = persist.PrivateNodeKey } if !persist.OldPrivateNodeKey.IsZero() { oldNodeKey = persist.OldPrivateNodeKey.Public() } if tryingNewKey.IsZero() { if opt.Logout { return false, "", errors.New("no nodekey to log out") } log.Fatalf("tryingNewKey is empty, give up") } if backendLogID == "" { err = errors.New("hostinfo: BackendLogID missing") return regen, opt.URL, err } now := time.Now().Round(time.Second) request := tailcfg.RegisterRequest{ Version: 1, OldNodeKey: tailcfg.NodeKey(oldNodeKey), NodeKey: tailcfg.NodeKey(tryingNewKey.Public()), Hostinfo: hostinfo, Followup: opt.URL, Timestamp: &now, } if opt.Logout { request.Expiry = time.Unix(123, 0) // far in the past } c.logf("RegisterReq: onode=%v node=%v fup=%v", request.OldNodeKey.ShortString(), request.NodeKey.ShortString(), opt.URL != "") request.Auth.Oauth2Token = opt.Token request.Auth.Provider = persist.Provider request.Auth.LoginName = persist.LoginName request.Auth.AuthKey = authKey err = signRegisterRequest(&request, c.serverURL, c.serverKey, machinePrivKey.Public()) if err != nil { // If signing failed, clear all related fields request.SignatureType = tailcfg.SignatureNone request.Timestamp = nil request.DeviceCert = nil request.Signature = nil // Don't log the common error types. Signatures are not usually enabled, // so these are expected. if !errors.Is(err, errCertificateNotConfigured) && !errors.Is(err, errNoCertStore) { c.logf("RegisterReq sign error: %v", err) } } if debugRegister { j, _ := json.MarshalIndent(request, "", "\t") c.logf("RegisterRequest: %s", j) } bodyData, err := encode(request, &serverKey, &machinePrivKey) if err != nil { return regen, opt.URL, err } body := bytes.NewReader(bodyData) u := fmt.Sprintf("%s/machine/%s", c.serverURL, machinePrivKey.Public().HexString()) req, err := http.NewRequest("POST", u, body) if err != nil { return regen, opt.URL, err } req = req.WithContext(ctx) res, err := c.httpc.Do(req) if err != nil { return regen, opt.URL, fmt.Errorf("register request: %v", err) } if res.StatusCode != 200 { msg, _ := ioutil.ReadAll(res.Body) res.Body.Close() return regen, opt.URL, fmt.Errorf("register request: http %d: %.200s", res.StatusCode, strings.TrimSpace(string(msg))) } resp := tailcfg.RegisterResponse{} if err := decode(res, &resp, &serverKey, &machinePrivKey); err != nil { c.logf("error decoding RegisterResponse with server key %s and machine key %s: %v", serverKey, machinePrivKey.Public(), err) return regen, opt.URL, fmt.Errorf("register request: %v", err) } if debugRegister { j, _ := json.MarshalIndent(resp, "", "\t") c.logf("RegisterResponse: %s", j) } // Log without PII: c.logf("RegisterReq: got response; nodeKeyExpired=%v, machineAuthorized=%v; authURL=%v", resp.NodeKeyExpired, resp.MachineAuthorized, resp.AuthURL != "") if resp.NodeKeyExpired { if regen { return true, "", fmt.Errorf("weird: regen=true but server says NodeKeyExpired: %v", request.NodeKey) } c.logf("server reports new node key %v has expired", request.NodeKey.ShortString()) return true, "", nil } if resp.Login.Provider != "" { persist.Provider = resp.Login.Provider } if resp.Login.LoginName != "" { persist.LoginName = resp.Login.LoginName } // TODO(crawshaw): RegisterResponse should be able to mechanically // communicate some extra instructions from the server: // - new node key required // - machine key no longer supported // - user is disabled if resp.AuthURL != "" { c.logf("AuthURL is %v", resp.AuthURL) } else { c.logf("No AuthURL") } c.mu.Lock() if resp.AuthURL == "" { // key rotation is complete persist.PrivateNodeKey = tryingNewKey } else { // save it for the retry-with-URL c.tryingNewKey = tryingNewKey } c.persist = persist c.mu.Unlock() if err != nil { return regen, "", err } if ctx.Err() != nil { return regen, "", ctx.Err() } return false, resp.AuthURL, nil } func sameEndpoints(a, b []tailcfg.Endpoint) bool { if len(a) != len(b) { return false } for i := range a { if a[i] != b[i] { return false } } return true } // newEndpoints acquires c.mu and sets the local port and endpoints and reports // whether they've changed. // // It does not retain the provided slice. func (c *Direct) newEndpoints(localPort uint16, endpoints []tailcfg.Endpoint) (changed bool) { c.mu.Lock() defer c.mu.Unlock() // Nothing new? if c.localPort == localPort && sameEndpoints(c.endpoints, endpoints) { return false // unchanged } var epStrs []string for _, ep := range endpoints { epStrs = append(epStrs, ep.Addr.String()) } c.logf("client.newEndpoints(%v, %v)", localPort, epStrs) c.localPort = localPort c.endpoints = append(c.endpoints[:0], endpoints...) if len(endpoints) > 0 { c.everEndpoints = true } return true // changed } // SetEndpoints updates the list of locally advertised endpoints. // It won't be replicated to the server until a *fresh* call to PollNetMap(). // You don't need to restart PollNetMap if we return changed==false. func (c *Direct) SetEndpoints(localPort uint16, endpoints []tailcfg.Endpoint) (changed bool) { // (no log message on function entry, because it clutters the logs // if endpoints haven't changed. newEndpoints() will log it.) return c.newEndpoints(localPort, endpoints) } func inTest() bool { return flag.Lookup("test.v") != nil } // PollNetMap makes a /map request to download the network map, calling cb with // each new netmap. // // maxPolls is how many network maps to download; common values are 1 // or -1 (to keep a long-poll query open to the server). func (c *Direct) PollNetMap(ctx context.Context, maxPolls int, cb func(*netmap.NetworkMap)) error { return c.sendMapRequest(ctx, maxPolls, cb) } // SendLiteMapUpdate makes a /map request to update the server of our latest state, // but does not fetch anything. It returns an error if the server did not return a // successful 200 OK response. func (c *Direct) SendLiteMapUpdate(ctx context.Context) error { return c.sendMapRequest(ctx, 1, nil) } // If we go more than pollTimeout without hearing from the server, // end the long poll. We should be receiving a keep alive ping // every minute. const pollTimeout = 120 * time.Second // cb nil means to omit peers. func (c *Direct) sendMapRequest(ctx context.Context, maxPolls int, cb func(*netmap.NetworkMap)) error { c.mu.Lock() persist := c.persist serverURL := c.serverURL serverKey := c.serverKey hostinfo := c.hostinfo.Clone() backendLogID := hostinfo.BackendLogID localPort := c.localPort var epStrs []string var epTypes []tailcfg.EndpointType for _, ep := range c.endpoints { epStrs = append(epStrs, ep.Addr.String()) epTypes = append(epTypes, ep.Type) } everEndpoints := c.everEndpoints c.mu.Unlock() machinePrivKey, err := c.getMachinePrivKey() if err != nil { return fmt.Errorf("getMachinePrivKey: %w", err) } if machinePrivKey.IsZero() { return errors.New("getMachinePrivKey returned zero key") } if persist.PrivateNodeKey.IsZero() { return errors.New("privateNodeKey is zero") } if backendLogID == "" { return errors.New("hostinfo: BackendLogID missing") } allowStream := maxPolls != 1 c.logf("[v1] PollNetMap: stream=%v :%v ep=%v", allowStream, localPort, epStrs) vlogf := logger.Discard if Debug.NetMap { // TODO(bradfitz): update this to use "[v2]" prefix perhaps? but we don't // want to upload it always. vlogf = c.logf } request := &tailcfg.MapRequest{ Version: tailcfg.CurrentMapRequestVersion, KeepAlive: c.keepAlive, NodeKey: tailcfg.NodeKey(persist.PrivateNodeKey.Public()), DiscoKey: c.discoPubKey, Endpoints: epStrs, EndpointTypes: epTypes, Stream: allowStream, Hostinfo: hostinfo, DebugFlags: c.debugFlags, OmitPeers: cb == nil, } var extraDebugFlags []string if hostinfo != nil && c.linkMon != nil && !c.skipIPForwardingCheck && ipForwardingBroken(hostinfo.RoutableIPs, c.linkMon.InterfaceState()) { extraDebugFlags = append(extraDebugFlags, "warn-ip-forwarding-off") } if health.RouterHealth() != nil { extraDebugFlags = append(extraDebugFlags, "warn-router-unhealthy") } if health.NetworkCategoryHealth() != nil { extraDebugFlags = append(extraDebugFlags, "warn-network-category-unhealthy") } if len(extraDebugFlags) > 0 { old := request.DebugFlags request.DebugFlags = append(old[:len(old):len(old)], extraDebugFlags...) } if c.newDecompressor != nil { request.Compress = "zstd" } // On initial startup before we know our endpoints, set the ReadOnly flag // to tell the control server not to distribute out our (empty) endpoints to peers. // Presumably we'll learn our endpoints in a half second and do another post // with useful results. The first POST just gets us the DERP map which we // need to do the STUN queries to discover our endpoints. // TODO(bradfitz): we skip this optimization in tests, though, // because the e2e tests are currently hyperspecific about the // ordering of things. The e2e tests need love. if len(epStrs) == 0 && !everEndpoints && !inTest() { request.ReadOnly = true } bodyData, err := encode(request, &serverKey, &machinePrivKey) if err != nil { vlogf("netmap: encode: %v", err) return err } ctx, cancel := context.WithCancel(ctx) defer cancel() machinePubKey := tailcfg.MachineKey(machinePrivKey.Public()) t0 := time.Now() u := fmt.Sprintf("%s/machine/%s/map", serverURL, machinePubKey.HexString()) req, err := http.NewRequestWithContext(ctx, "POST", u, bytes.NewReader(bodyData)) if err != nil { return err } res, err := c.httpc.Do(req) if err != nil { vlogf("netmap: Do: %v", err) return err } vlogf("netmap: Do = %v after %v", res.StatusCode, time.Since(t0).Round(time.Millisecond)) if res.StatusCode != 200 { msg, _ := ioutil.ReadAll(res.Body) res.Body.Close() return fmt.Errorf("initial fetch failed %d: %.200s", res.StatusCode, strings.TrimSpace(string(msg))) } defer res.Body.Close() health.NoteMapRequestHeard(request) if cb == nil { io.Copy(ioutil.Discard, res.Body) return nil } timeout := time.NewTimer(pollTimeout) timeoutReset := make(chan struct{}) pollDone := make(chan struct{}) defer close(pollDone) go func() { for { select { case <-pollDone: vlogf("netmap: ending timeout goroutine") return case <-timeout.C: c.logf("map response long-poll timed out!") cancel() return case <-timeoutReset: if !timeout.Stop() { select { case <-timeout.C: case <-pollDone: vlogf("netmap: ending timeout goroutine") return } } vlogf("netmap: reset timeout timer") timeout.Reset(pollTimeout) } } }() sess := newMapSession(persist.PrivateNodeKey) sess.logf = c.logf sess.vlogf = vlogf sess.machinePubKey = machinePubKey sess.keepSharerAndUserSplit = c.keepSharerAndUserSplit // If allowStream, then the server will use an HTTP long poll to // return incremental results. There is always one response right // away, followed by a delay, and eventually others. // If !allowStream, it'll still send the first result in exactly // the same format before just closing the connection. // We can use this same read loop either way. var msg []byte for i := 0; i < maxPolls || maxPolls < 0; i++ { vlogf("netmap: starting size read after %v (poll %v)", time.Since(t0).Round(time.Millisecond), i) var siz [4]byte if _, err := io.ReadFull(res.Body, siz[:]); err != nil { vlogf("netmap: size read error after %v: %v", time.Since(t0).Round(time.Millisecond), err) return err } size := binary.LittleEndian.Uint32(siz[:]) vlogf("netmap: read size %v after %v", size, time.Since(t0).Round(time.Millisecond)) msg = append(msg[:0], make([]byte, size)...) if _, err := io.ReadFull(res.Body, msg); err != nil { vlogf("netmap: body read error: %v", err) return err } vlogf("netmap: read body after %v", time.Since(t0).Round(time.Millisecond)) var resp tailcfg.MapResponse if err := c.decodeMsg(msg, &resp, &machinePrivKey); err != nil { vlogf("netmap: decode error: %v") return err } if allowStream { health.GotStreamedMapResponse() } if pr := resp.PingRequest; pr != nil { go answerPing(c.logf, c.httpc, pr) } if resp.KeepAlive { vlogf("netmap: got keep-alive") } else { vlogf("netmap: got new map") } select { case timeoutReset <- struct{}{}: vlogf("netmap: sent timer reset") case <-ctx.Done(): c.logf("[v1] netmap: not resetting timer; context done: %v", ctx.Err()) return ctx.Err() } if resp.KeepAlive { continue } if resp.Debug != nil { if resp.Debug.LogHeapPprof { go logheap.LogHeap(resp.Debug.LogHeapURL) } if resp.Debug.GoroutineDumpURL != "" { go dumpGoroutinesToURL(c.httpc, resp.Debug.GoroutineDumpURL) } setControlAtomic(&controlUseDERPRoute, resp.Debug.DERPRoute) setControlAtomic(&controlTrimWGConfig, resp.Debug.TrimWGConfig) if sleep := time.Duration(resp.Debug.SleepSeconds * float64(time.Second)); sleep > 0 { if err := sleepAsRequested(ctx, c.logf, timeoutReset, sleep); err != nil { return err } } } nm := sess.netmapForResponse(&resp) if nm.SelfNode == nil { c.logf("MapResponse lacked node") return errors.New("MapResponse lacked node") } // Temporarily (2020-06-29) support removing all but // discovery-supporting nodes during development, for // less noise. if Debug.OnlyDisco { anyOld, numDisco := false, 0 for _, p := range nm.Peers { if p.DiscoKey.IsZero() { anyOld = true } else { numDisco++ } } if anyOld { filtered := make([]*tailcfg.Node, 0, numDisco) for _, p := range nm.Peers { if !p.DiscoKey.IsZero() { filtered = append(filtered, p) } } nm.Peers = filtered } } if Debug.StripEndpoints { for _, p := range resp.Peers { // We need at least one endpoint here for now else // other code doesn't even create the discoEndpoint. // TODO(bradfitz): fix that and then just nil this out. p.Endpoints = []string{"127.9.9.9:456"} } } if Debug.StripCaps { nm.SelfNode.Capabilities = nil } // Get latest localPort. This might've changed if // a lite map update occured meanwhile. This only affects // the end-to-end test. // TODO(bradfitz): remove the NetworkMap.LocalPort field entirely. c.mu.Lock() nm.LocalPort = c.localPort c.mu.Unlock() // Printing the netmap can be extremely verbose, but is very // handy for debugging. Let's limit how often we do it. // Code elsewhere prints netmap diffs every time, so this // occasional full dump, plus incremental diffs, should do // the job. now := c.timeNow() if now.Sub(c.lastPrintMap) >= 5*time.Minute { c.lastPrintMap = now c.logf("[v1] new network map[%d]:\n%s", i, nm.Concise()) } c.mu.Lock() c.expiry = &nm.Expiry c.mu.Unlock() cb(nm) } if ctx.Err() != nil { return ctx.Err() } return nil } func decode(res *http.Response, v interface{}, serverKey *wgkey.Key, mkey *wgkey.Private) error { defer res.Body.Close() msg, err := ioutil.ReadAll(io.LimitReader(res.Body, 1<<20)) if err != nil { return err } if res.StatusCode != 200 { return fmt.Errorf("%d: %v", res.StatusCode, string(msg)) } return decodeMsg(msg, v, serverKey, mkey) } var ( debugMap, _ = strconv.ParseBool(os.Getenv("TS_DEBUG_MAP")) debugRegister, _ = strconv.ParseBool(os.Getenv("TS_DEBUG_REGISTER")) ) var jsonEscapedZero = []byte(`\u0000`) func (c *Direct) decodeMsg(msg []byte, v interface{}, machinePrivKey *wgkey.Private) error { c.mu.Lock() serverKey := c.serverKey c.mu.Unlock() decrypted, err := decryptMsg(msg, &serverKey, machinePrivKey) if err != nil { return err } var b []byte if c.newDecompressor == nil { b = decrypted } else { decoder, err := c.newDecompressor() if err != nil { return err } defer decoder.Close() b, err = decoder.DecodeAll(decrypted, nil) if err != nil { return err } } if debugMap { var buf bytes.Buffer json.Indent(&buf, b, "", " ") log.Printf("MapResponse: %s", buf.Bytes()) } if bytes.Contains(b, jsonEscapedZero) { log.Printf("[unexpected] zero byte in controlclient.Direct.decodeMsg into %T: %q", v, b) } if err := json.Unmarshal(b, v); err != nil { return fmt.Errorf("response: %v", err) } return nil } func decodeMsg(msg []byte, v interface{}, serverKey *wgkey.Key, machinePrivKey *wgkey.Private) error { decrypted, err := decryptMsg(msg, serverKey, machinePrivKey) if err != nil { return err } if bytes.Contains(decrypted, jsonEscapedZero) { log.Printf("[unexpected] zero byte in controlclient decodeMsg into %T: %q", v, decrypted) } if err := json.Unmarshal(decrypted, v); err != nil { return fmt.Errorf("response: %v", err) } return nil } func decryptMsg(msg []byte, serverKey *wgkey.Key, mkey *wgkey.Private) ([]byte, error) { var nonce [24]byte if len(msg) < len(nonce)+1 { return nil, fmt.Errorf("response missing nonce, len=%d", len(msg)) } copy(nonce[:], msg) msg = msg[len(nonce):] pub, pri := (*[32]byte)(serverKey), (*[32]byte)(mkey) decrypted, ok := box.Open(nil, msg, &nonce, pub, pri) if !ok { return nil, fmt.Errorf("cannot decrypt response (len %d + nonce %d = %d)", len(msg), len(nonce), len(msg)+len(nonce)) } return decrypted, nil } func encode(v interface{}, serverKey *wgkey.Key, mkey *wgkey.Private) ([]byte, error) { b, err := json.Marshal(v) if err != nil { return nil, err } if debugMap { if _, ok := v.(*tailcfg.MapRequest); ok { log.Printf("MapRequest: %s", b) } } var nonce [24]byte if _, err := io.ReadFull(rand.Reader, nonce[:]); err != nil { panic(err) } pub, pri := (*[32]byte)(serverKey), (*[32]byte)(mkey) msg := box.Seal(nonce[:], b, &nonce, pub, pri) return msg, nil } func loadServerKey(ctx context.Context, httpc *http.Client, serverURL string) (wgkey.Key, error) { req, err := http.NewRequest("GET", serverURL+"/key", nil) if err != nil { return wgkey.Key{}, fmt.Errorf("create control key request: %v", err) } req = req.WithContext(ctx) res, err := httpc.Do(req) if err != nil { return wgkey.Key{}, fmt.Errorf("fetch control key: %v", err) } defer res.Body.Close() b, err := ioutil.ReadAll(io.LimitReader(res.Body, 1<<16)) if err != nil { return wgkey.Key{}, fmt.Errorf("fetch control key response: %v", err) } if res.StatusCode != 200 { return wgkey.Key{}, fmt.Errorf("fetch control key: %d: %s", res.StatusCode, string(b)) } key, err := wgkey.ParseHex(string(b)) if err != nil { return wgkey.Key{}, fmt.Errorf("fetch control key: %v", err) } return key, nil } // Debug contains temporary internal-only debug knobs. // They're unexported to not draw attention to them. var Debug = initDebug() type debug struct { NetMap bool ProxyDNS bool OnlyDisco bool Disco bool StripEndpoints bool // strip endpoints from control (only use disco messages) StripCaps bool // strip all local node's control-provided capabilities } func initDebug() debug { use := os.Getenv("TS_DEBUG_USE_DISCO") return debug{ NetMap: envBool("TS_DEBUG_NETMAP"), ProxyDNS: envBool("TS_DEBUG_PROXY_DNS"), StripEndpoints: envBool("TS_DEBUG_STRIP_ENDPOINTS"), StripCaps: envBool("TS_DEBUG_STRIP_CAPS"), OnlyDisco: use == "only", Disco: use == "only" || use == "" || envBool("TS_DEBUG_USE_DISCO"), } } func envBool(k string) bool { e := os.Getenv(k) if e == "" { return false } v, err := strconv.ParseBool(e) if err != nil { panic(fmt.Sprintf("invalid non-bool %q for env var %q", e, k)) } return v } var clockNow = time.Now // opt.Bool configs from control. var ( controlUseDERPRoute atomic.Value controlTrimWGConfig atomic.Value ) func setControlAtomic(dst *atomic.Value, v opt.Bool) { old, ok := dst.Load().(opt.Bool) if !ok || old != v { dst.Store(v) } } // DERPRouteFlag reports the last reported value from control for whether // DERP route optimization (Issue 150) should be enabled. func DERPRouteFlag() opt.Bool { v, _ := controlUseDERPRoute.Load().(opt.Bool) return v } // TrimWGConfig reports the last reported value from control for whether // we should do lazy wireguard configuration. func TrimWGConfig() opt.Bool { v, _ := controlTrimWGConfig.Load().(opt.Bool) return v } // ipForwardingBroken reports whether the system's IP forwarding is disabled // and will definitely not work for the routes provided. // // It should not return false positives. // // TODO(bradfitz): merge this code into LocalBackend.CheckIPForwarding // and change controlclient.Options.SkipIPForwardingCheck into a // func([]netaddr.IPPrefix) error signature instead. Then we only have // one copy of this code. func ipForwardingBroken(routes []netaddr.IPPrefix, state *interfaces.State) bool { if len(routes) == 0 { // Nothing to route, so no need to warn. return false } if runtime.GOOS != "linux" { // We only do subnet routing on Linux for now. // It might work on darwin/macOS when building from source, so // don't return true for other OSes. We can OS-based warnings // already in the admin panel. return false } localIPs := map[netaddr.IP]bool{} for _, addrs := range state.InterfaceIPs { for _, pfx := range addrs { localIPs[pfx.IP()] = true } } v4Routes, v6Routes := false, false for _, r := range routes { // It's possible to advertise a route to one of the local // machine's local IPs. IP forwarding isn't required for this // to work, so we shouldn't warn for such exports. if r.IsSingleIP() && localIPs[r.IP()] { continue } if r.IP().Is4() { v4Routes = true } else { v6Routes = true } } if v4Routes { out, err := ioutil.ReadFile("/proc/sys/net/ipv4/ip_forward") if err != nil { // Try another way. out, err = exec.Command("sysctl", "-n", "net.ipv4.ip_forward").Output() } if err != nil { // Oh well, we tried. This is just for debugging. // We don't want false positives. // TODO: maybe we want a different warning for inability to check? return false } if strings.TrimSpace(string(out)) == "0" { return true } } if v6Routes { // Note: you might be wondering why we check only the state of // conf.all.forwarding, rather than per-interface forwarding // configuration. According to kernel documentation, it seems // that to actually forward packets, you need to enable // forwarding globally, and the per-interface forwarding // setting only alters other things such as how router // advertisements are handled. The kernel itself warns that // enabling forwarding per-interface and not globally will // probably not work, so I feel okay calling those configs // broken until we have proof otherwise. out, err := ioutil.ReadFile("/proc/sys/net/ipv6/conf/all/forwarding") if err != nil { out, err = exec.Command("sysctl", "-n", "net.ipv6.conf.all.forwarding").Output() } if err != nil { // Oh well, we tried. This is just for debugging. // We don't want false positives. // TODO: maybe we want a different warning for inability to check? return false } if strings.TrimSpace(string(out)) == "0" { return true } } return false } func answerPing(logf logger.Logf, c *http.Client, pr *tailcfg.PingRequest) { if pr.URL == "" { logf("invalid PingRequest with no URL") return } ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second) defer cancel() req, err := http.NewRequestWithContext(ctx, "HEAD", pr.URL, nil) if err != nil { logf("http.NewRequestWithContext(%q): %v", pr.URL, err) return } if pr.Log { logf("answerPing: sending ping to %v ...", pr.URL) } t0 := time.Now() _, err = c.Do(req) d := time.Since(t0).Round(time.Millisecond) if err != nil { logf("answerPing error: %v to %v (after %v)", err, pr.URL, d) } else if pr.Log { logf("answerPing complete to %v (after %v)", pr.URL, d) } } func sleepAsRequested(ctx context.Context, logf logger.Logf, timeoutReset chan<- struct{}, d time.Duration) error { const maxSleep = 5 * time.Minute if d > maxSleep { logf("sleeping for %v, capped from server-requested %v ...", maxSleep, d) d = maxSleep } else { logf("sleeping for server-requested %v ...", d) } ticker := time.NewTicker(pollTimeout / 2) defer ticker.Stop() timer := time.NewTimer(d) defer timer.Stop() for { select { case <-ctx.Done(): return ctx.Err() case <-timer.C: return nil case <-ticker.C: select { case timeoutReset <- struct{}{}: case <-timer.C: return nil case <-ctx.Done(): return ctx.Err() } } } }