package tunnel import ( "crypto/tls" "fmt" "io/ioutil" mathRand "math/rand" "net" "net/netip" "os" "path/filepath" "strings" "time" "github.com/google/uuid" homedir "github.com/mitchellh/go-homedir" "github.com/pkg/errors" "github.com/rs/zerolog" "github.com/urfave/cli/v2" "github.com/urfave/cli/v2/altsrc" "golang.org/x/crypto/ssh/terminal" "github.com/cloudflare/cloudflared/cmd/cloudflared/cliutil" "github.com/cloudflare/cloudflared/config" "github.com/cloudflare/cloudflared/connection" "github.com/cloudflare/cloudflared/edgediscovery" "github.com/cloudflare/cloudflared/edgediscovery/allregions" "github.com/cloudflare/cloudflared/ingress" "github.com/cloudflare/cloudflared/orchestration" "github.com/cloudflare/cloudflared/supervisor" "github.com/cloudflare/cloudflared/tlsconfig" tunnelpogs "github.com/cloudflare/cloudflared/tunnelrpc/pogs" ) const LogFieldOriginCertPath = "originCertPath" const secretValue = "*****" var ( developerPortal = "https://developers.cloudflare.com/argo-tunnel" serviceUrl = developerPortal + "/reference/service/" argumentsUrl = developerPortal + "/reference/arguments/" secretFlags = [2]*altsrc.StringFlag{credentialsContentsFlag, tunnelTokenFlag} defaultFeatures = []string{supervisor.FeatureAllowRemoteConfig, supervisor.FeatureSerializedHeaders, supervisor.FeatureDatagramV2, supervisor.FeatureQUICSupportEOF} configFlags = []string{"autoupdate-freq", "no-autoupdate", "retries", "protocol", "loglevel", "transport-loglevel", "origincert", "metrics", "metrics-update-freq", "edge-ip-version", "edge-bind-address"} ) // returns the first path that contains a cert.pem file. If none of the DefaultConfigSearchDirectories // contains a cert.pem file, return empty string func findDefaultOriginCertPath() string { for _, defaultConfigDir := range config.DefaultConfigSearchDirectories() { originCertPath, _ := homedir.Expand(filepath.Join(defaultConfigDir, config.DefaultCredentialFile)) if ok, _ := config.FileExists(originCertPath); ok { return originCertPath } } return "" } func generateRandomClientID(log *zerolog.Logger) (string, error) { u, err := uuid.NewRandom() if err != nil { log.Error().Msgf("couldn't create UUID for client ID %s", err) return "", err } return u.String(), nil } func logClientOptions(c *cli.Context, log *zerolog.Logger) { flags := make(map[string]interface{}) for _, flag := range c.FlagNames() { if isSecretFlag(flag) { flags[flag] = secretValue } else { flags[flag] = c.Generic(flag) } } if len(flags) > 0 { log.Info().Msgf("Settings: %v", flags) } envs := make(map[string]string) // Find env variables for Argo Tunnel for _, env := range os.Environ() { // All Argo Tunnel env variables start with TUNNEL_ if strings.Contains(env, "TUNNEL_") { vars := strings.Split(env, "=") if len(vars) == 2 { if isSecretEnvVar(vars[0]) { envs[vars[0]] = secretValue } else { envs[vars[0]] = vars[1] } } } } if len(envs) > 0 { log.Info().Msgf("Environmental variables %v", envs) } } func isSecretFlag(key string) bool { for _, flag := range secretFlags { if flag.Name == key { return true } } return false } func isSecretEnvVar(key string) bool { for _, flag := range secretFlags { for _, secretEnvVar := range flag.EnvVars { if secretEnvVar == key { return true } } } return false } func dnsProxyStandAlone(c *cli.Context, namedTunnel *connection.NamedTunnelProperties) bool { return c.IsSet("proxy-dns") && !(c.IsSet("name") || // adhoc-named tunnel c.IsSet(ingress.HelloWorldFlag) || // quick or named tunnel namedTunnel != nil) // named tunnel } func findOriginCert(originCertPath string, log *zerolog.Logger) (string, error) { if originCertPath == "" { log.Info().Msgf("Cannot determine default origin certificate path. No file %s in %v", config.DefaultCredentialFile, config.DefaultConfigSearchDirectories()) if isRunningFromTerminal() { log.Error().Msgf("You need to specify the origin certificate path with --origincert option, or set TUNNEL_ORIGIN_CERT environment variable. See %s for more information.", argumentsUrl) return "", fmt.Errorf("client didn't specify origincert path when running from terminal") } else { log.Error().Msgf("You need to specify the origin certificate path by specifying the origincert option in the configuration file, or set TUNNEL_ORIGIN_CERT environment variable. See %s for more information.", serviceUrl) return "", fmt.Errorf("client didn't specify origincert path") } } var err error originCertPath, err = homedir.Expand(originCertPath) if err != nil { log.Err(err).Msgf("Cannot resolve origin certificate path") return "", fmt.Errorf("cannot resolve path %s", originCertPath) } // Check that the user has acquired a certificate using the login command ok, err := config.FileExists(originCertPath) if err != nil { log.Error().Err(err).Msgf("Cannot check if origin cert exists at path %s", originCertPath) return "", fmt.Errorf("cannot check if origin cert exists at path %s", originCertPath) } if !ok { log.Error().Msgf(`Cannot find a valid certificate for your origin at the path: %s If the path above is wrong, specify the path with the -origincert option. If you don't have a certificate signed by Cloudflare, run the command: %s login `, originCertPath, os.Args[0]) return "", fmt.Errorf("cannot find a valid certificate at the path %s", originCertPath) } return originCertPath, nil } func readOriginCert(originCertPath string) ([]byte, error) { // Easier to send the certificate as []byte via RPC than decoding it at this point originCert, err := ioutil.ReadFile(originCertPath) if err != nil { return nil, fmt.Errorf("cannot read %s to load origin certificate", originCertPath) } return originCert, nil } func getOriginCert(originCertPath string, log *zerolog.Logger) ([]byte, error) { if originCertPath, err := findOriginCert(originCertPath, log); err != nil { return nil, err } else { return readOriginCert(originCertPath) } } func prepareTunnelConfig( c *cli.Context, info *cliutil.BuildInfo, log, logTransport *zerolog.Logger, observer *connection.Observer, namedTunnel *connection.NamedTunnelProperties, ) (*supervisor.TunnelConfig, *orchestration.Config, error) { clientID, err := uuid.NewRandom() if err != nil { return nil, nil, errors.Wrap(err, "can't generate connector UUID") } log.Info().Msgf("Generated Connector ID: %s", clientID) tags, err := NewTagSliceFromCLI(c.StringSlice("tag")) if err != nil { log.Err(err).Msg("Tag parse failure") return nil, nil, errors.Wrap(err, "Tag parse failure") } tags = append(tags, tunnelpogs.Tag{Name: "ID", Value: clientID.String()}) transportProtocol := c.String("protocol") needPQ := c.Bool("post-quantum") if needPQ { if FipsEnabled { return nil, nil, fmt.Errorf("post-quantum not supported in FIPS mode") } // Error if the user tries to force a non-quic transport protocol if transportProtocol != connection.AutoSelectFlag && transportProtocol != connection.QUIC.String() { return nil, nil, fmt.Errorf("post-quantum is only supported with the quic transport") } transportProtocol = connection.QUIC.String() } features := dedup(append(c.StringSlice("features"), defaultFeatures...)) if needPQ { features = append(features, supervisor.FeaturePostQuantum) } namedTunnel.Client = tunnelpogs.ClientInfo{ ClientID: clientID[:], Features: features, Version: info.Version(), Arch: info.OSArch(), } cfg := config.GetConfiguration() ingressRules, err := ingress.ParseIngressFromConfigAndCLI(cfg, c, log) if err != nil { return nil, nil, err } protocolSelector, err := connection.NewProtocolSelector(transportProtocol, namedTunnel.Credentials.AccountTag, c.IsSet(TunnelTokenFlag), c.Bool("post-quantum"), edgediscovery.ProtocolPercentage, connection.ResolveTTL, log) if err != nil { return nil, nil, err } log.Info().Msgf("Initial protocol %s", protocolSelector.Current()) edgeTLSConfigs := make(map[connection.Protocol]*tls.Config, len(connection.ProtocolList)) for _, p := range connection.ProtocolList { tlsSettings := p.TLSSettings() if tlsSettings == nil { return nil, nil, fmt.Errorf("%s has unknown TLS settings", p) } edgeTLSConfig, err := tlsconfig.CreateTunnelConfig(c, tlsSettings.ServerName) if err != nil { return nil, nil, errors.Wrap(err, "unable to create TLS config to connect with edge") } if len(tlsSettings.NextProtos) > 0 { edgeTLSConfig.NextProtos = tlsSettings.NextProtos } edgeTLSConfigs[p] = edgeTLSConfig } gracePeriod, err := gracePeriod(c) if err != nil { return nil, nil, err } edgeIPVersion, err := parseConfigIPVersion(c.String("edge-ip-version")) if err != nil { return nil, nil, err } edgeBindAddr, err := parseConfigBindAddress(c.String("edge-bind-address")) if err != nil { return nil, nil, err } if err := testIPBindable(edgeBindAddr); err != nil { return nil, nil, fmt.Errorf("invalid edge-bind-address %s: %v", edgeBindAddr, err) } edgeIPVersion, err = adjustIPVersionByBindAddress(edgeIPVersion, edgeBindAddr) if err != nil { // This is not a fatal error, we just overrode edgeIPVersion log.Warn().Str("edgeIPVersion", edgeIPVersion.String()).Err(err).Msg("Overriding edge-ip-version") } var pqKexIdx int if needPQ { pqKexIdx = mathRand.Intn(len(supervisor.PQKexes)) log.Info().Msgf( "Using experimental hybrid post-quantum key agreement %s", supervisor.PQKexNames[supervisor.PQKexes[pqKexIdx]], ) } tunnelConfig := &supervisor.TunnelConfig{ GracePeriod: gracePeriod, ReplaceExisting: c.Bool("force"), OSArch: info.OSArch(), ClientID: clientID.String(), EdgeAddrs: c.StringSlice("edge"), Region: c.String("region"), EdgeIPVersion: edgeIPVersion, EdgeBindAddr: edgeBindAddr, HAConnections: c.Int(haConnectionsFlag), IncidentLookup: supervisor.NewIncidentLookup(), IsAutoupdated: c.Bool("is-autoupdated"), LBPool: c.String("lb-pool"), Tags: tags, Log: log, LogTransport: logTransport, Observer: observer, ReportedVersion: info.Version(), // Note TUN-3758 , we use Int because UInt is not supported with altsrc Retries: uint(c.Int("retries")), RunFromTerminal: isRunningFromTerminal(), NamedTunnel: namedTunnel, ProtocolSelector: protocolSelector, EdgeTLSConfigs: edgeTLSConfigs, NeedPQ: needPQ, PQKexIdx: pqKexIdx, MaxEdgeAddrRetries: uint8(c.Int("max-edge-addr-retries")), } packetConfig, err := newPacketConfig(c, log) if err != nil { log.Warn().Err(err).Msg("ICMP proxy feature is disabled") } else { tunnelConfig.PacketConfig = packetConfig } orchestratorConfig := &orchestration.Config{ Ingress: &ingressRules, WarpRouting: ingress.NewWarpRoutingConfig(&cfg.WarpRouting), ConfigurationFlags: parseConfigFlags(c), } return tunnelConfig, orchestratorConfig, nil } func parseConfigFlags(c *cli.Context) map[string]string { result := make(map[string]string) for _, flag := range configFlags { if v := c.String(flag); c.IsSet(flag) && v != "" { result[flag] = v } } return result } func gracePeriod(c *cli.Context) (time.Duration, error) { period := c.Duration("grace-period") if period > connection.MaxGracePeriod { return time.Duration(0), fmt.Errorf("grace-period must be equal or less than %v", connection.MaxGracePeriod) } return period, nil } func isRunningFromTerminal() bool { return terminal.IsTerminal(int(os.Stdout.Fd())) } // Remove any duplicates from the slice func dedup(slice []string) []string { // Convert the slice into a set set := make(map[string]bool, 0) for _, str := range slice { set[str] = true } // Convert the set back into a slice keys := make([]string, len(set)) i := 0 for str := range set { keys[i] = str i++ } return keys } // ParseConfigIPVersion returns the IP version from possible expected values from config func parseConfigIPVersion(version string) (v allregions.ConfigIPVersion, err error) { switch version { case "4": v = allregions.IPv4Only case "6": v = allregions.IPv6Only case "auto": v = allregions.Auto default: // unspecified or invalid err = fmt.Errorf("invalid value for edge-ip-version: %s", version) } return } func parseConfigBindAddress(ipstr string) (net.IP, error) { // Unspecified - it's fine if ipstr == "" { return nil, nil } ip := net.ParseIP(ipstr) if ip == nil { return nil, fmt.Errorf("invalid value for edge-bind-address: %s", ipstr) } return ip, nil } func testIPBindable(ip net.IP) error { // "Unspecified" = let OS choose, so always bindable if ip == nil { return nil } addr := &net.UDPAddr{IP: ip, Port: 0} listener, err := net.ListenUDP("udp", addr) if err != nil { return err } listener.Close() return nil } func adjustIPVersionByBindAddress(ipVersion allregions.ConfigIPVersion, ip net.IP) (allregions.ConfigIPVersion, error) { if ip == nil { return ipVersion, nil } // https://pkg.go.dev/net#IP.To4: "If ip is not an IPv4 address, To4 returns nil." if ip.To4() != nil { if ipVersion == allregions.IPv6Only { return allregions.IPv4Only, fmt.Errorf("IPv4 bind address is specified, but edge-ip-version is IPv6") } return allregions.IPv4Only, nil } else { if ipVersion == allregions.IPv4Only { return allregions.IPv6Only, fmt.Errorf("IPv6 bind address is specified, but edge-ip-version is IPv4") } return allregions.IPv6Only, nil } } func newPacketConfig(c *cli.Context, logger *zerolog.Logger) (*ingress.GlobalRouterConfig, error) { ipv4Src, err := determineICMPv4Src(c.String("icmpv4-src"), logger) if err != nil { return nil, errors.Wrap(err, "failed to determine IPv4 source address for ICMP proxy") } logger.Info().Msgf("ICMP proxy will use %s as source for IPv4", ipv4Src) ipv6Src, zone, err := determineICMPv6Src(c.String("icmpv6-src"), logger, ipv4Src) if err != nil { return nil, errors.Wrap(err, "failed to determine IPv6 source address for ICMP proxy") } if zone != "" { logger.Info().Msgf("ICMP proxy will use %s in zone %s as source for IPv6", ipv6Src, zone) } else { logger.Info().Msgf("ICMP proxy will use %s as source for IPv6", ipv6Src) } icmpRouter, err := ingress.NewICMPRouter(ipv4Src, ipv6Src, zone, logger) if err != nil { return nil, err } return &ingress.GlobalRouterConfig{ ICMPRouter: icmpRouter, IPv4Src: ipv4Src, IPv6Src: ipv6Src, Zone: zone, }, nil } func determineICMPv4Src(userDefinedSrc string, logger *zerolog.Logger) (netip.Addr, error) { if userDefinedSrc != "" { addr, err := netip.ParseAddr(userDefinedSrc) if err != nil { return netip.Addr{}, err } if addr.Is4() { return addr, nil } return netip.Addr{}, fmt.Errorf("expect IPv4, but %s is IPv6", userDefinedSrc) } addr, err := findLocalAddr(net.ParseIP("192.168.0.1"), 53) if err != nil { addr = netip.IPv4Unspecified() logger.Debug().Err(err).Msgf("Failed to determine the IPv4 for this machine. It will use %s to send/listen for ICMPv4 echo", addr) } return addr, nil } type interfaceIP struct { name string ip net.IP } func determineICMPv6Src(userDefinedSrc string, logger *zerolog.Logger, ipv4Src netip.Addr) (addr netip.Addr, zone string, err error) { if userDefinedSrc != "" { userDefinedIP, zone, _ := strings.Cut(userDefinedSrc, "%") addr, err := netip.ParseAddr(userDefinedIP) if err != nil { return netip.Addr{}, "", err } if addr.Is6() { return addr, zone, nil } return netip.Addr{}, "", fmt.Errorf("expect IPv6, but %s is IPv4", userDefinedSrc) } // Loop through all the interfaces, the preference is // 1. The interface where ipv4Src is in // 2. Interface with IPv6 address // 3. Unspecified interface interfaces, err := net.Interfaces() if err != nil { return netip.IPv6Unspecified(), "", nil } interfacesWithIPv6 := make([]interfaceIP, 0) for _, interf := range interfaces { interfaceAddrs, err := interf.Addrs() if err != nil { continue } foundIPv4SrcInterface := false for _, interfaceAddr := range interfaceAddrs { if ipnet, ok := interfaceAddr.(*net.IPNet); ok { ip := ipnet.IP if ip.Equal(ipv4Src.AsSlice()) { foundIPv4SrcInterface = true } if ip.To4() == nil { interfacesWithIPv6 = append(interfacesWithIPv6, interfaceIP{ name: interf.Name, ip: ip, }) } } } // Found the interface of ipv4Src. Loop through the addresses to see if there is an IPv6 if foundIPv4SrcInterface { for _, interfaceAddr := range interfaceAddrs { if ipnet, ok := interfaceAddr.(*net.IPNet); ok { ip := ipnet.IP if ip.To4() == nil { addr, err := netip.ParseAddr(ip.String()) if err == nil { return addr, interf.Name, nil } } } } } } for _, interf := range interfacesWithIPv6 { addr, err := netip.ParseAddr(interf.ip.String()) if err == nil { return addr, interf.name, nil } } logger.Debug().Err(err).Msgf("Failed to determine the IPv6 for this machine. It will use %s to send/listen for ICMPv6 echo", netip.IPv6Unspecified()) return netip.IPv6Unspecified(), "", nil } // FindLocalAddr tries to dial UDP and returns the local address picked by the OS func findLocalAddr(dst net.IP, port int) (netip.Addr, error) { udpConn, err := net.DialUDP("udp", nil, &net.UDPAddr{ IP: dst, Port: port, }) if err != nil { return netip.Addr{}, err } defer udpConn.Close() localAddrPort, err := netip.ParseAddrPort(udpConn.LocalAddr().String()) if err != nil { return netip.Addr{}, err } localAddr := localAddrPort.Addr() return localAddr, nil }