// Copyright (C) 2014 The Syncthing Authors. // // This Source Code Form is subject to the terms of the Mozilla Public // License, v. 2.0. If a copy of the MPL was not distributed with this file, // You can obtain one at http://mozilla.org/MPL/2.0/. // Adapted from https://github.com/jackpal/Taipei-Torrent/blob/dd88a8bfac6431c01d959ce3c745e74b8a911793/IGD.go // Copyright (c) 2010 Jack Palevich (https://github.com/jackpal/Taipei-Torrent/blob/dd88a8bfac6431c01d959ce3c745e74b8a911793/LICENSE) // Package upnp implements UPnP InternetGatewayDevice discovery, querying, and port mapping. package upnp import ( "bufio" "bytes" "encoding/xml" "errors" "fmt" "io/ioutil" "net" "net/http" "net/url" "regexp" "runtime" "strings" "time" "github.com/syncthing/syncthing/lib/dialer" "github.com/syncthing/syncthing/lib/sync" ) // An IGD is a UPnP InternetGatewayDevice. type IGD struct { uuid string friendlyName string services []IGDService url *url.URL localIPAddress string } func (n *IGD) UUID() string { return n.uuid } func (n *IGD) FriendlyName() string { return n.friendlyName } // FriendlyIdentifier returns a friendly identifier (friendly name + IP // address) for the IGD. func (n *IGD) FriendlyIdentifier() string { return "'" + n.FriendlyName() + "' (" + strings.Split(n.URL().Host, ":")[0] + ")" } func (n *IGD) URL() *url.URL { return n.url } // An IGDService is a specific service provided by an IGD. type IGDService struct { serviceID string serviceURL string serviceURN string } func (s *IGDService) ID() string { return s.serviceID } type Protocol string const ( TCP Protocol = "TCP" UDP = "UDP" ) type upnpService struct { ServiceID string `xml:"serviceId"` ServiceType string `xml:"serviceType"` ControlURL string `xml:"controlURL"` } type upnpDevice struct { DeviceType string `xml:"deviceType"` FriendlyName string `xml:"friendlyName"` Devices []upnpDevice `xml:"deviceList>device"` Services []upnpService `xml:"serviceList>service"` } type upnpRoot struct { Device upnpDevice `xml:"device"` } // Discover discovers UPnP InternetGatewayDevices. // The order in which the devices appear in the results list is not deterministic. func Discover(timeout time.Duration) []IGD { var results []IGD interfaces, err := net.Interfaces() if err != nil { l.Infoln("Listing network interfaces:", err) return results } resultChan := make(chan IGD) wg := sync.NewWaitGroup() for _, intf := range interfaces { // Interface flags seem to always be 0 on Windows if runtime.GOOS != "windows" && (intf.Flags&net.FlagUp == 0 || intf.Flags&net.FlagMulticast == 0) { continue } for _, deviceType := range []string{"urn:schemas-upnp-org:device:InternetGatewayDevice:1", "urn:schemas-upnp-org:device:InternetGatewayDevice:2"} { wg.Add(1) go func(intf net.Interface, deviceType string) { discover(&intf, deviceType, timeout, resultChan) wg.Done() }(intf, deviceType) } } go func() { wg.Wait() close(resultChan) }() nextResult: for result := range resultChan { for _, existingResult := range results { if existingResult.uuid == result.uuid { if shouldDebug() { l.Debugf("Skipping duplicate result %s with services:", result.uuid) for _, svc := range result.services { l.Debugf("* [%s] %s", svc.serviceID, svc.serviceURL) } } continue nextResult } } results = append(results, result) if shouldDebug() { l.Debugf("UPnP discovery result %s with services:", result.uuid) for _, svc := range result.services { l.Debugf("* [%s] %s", svc.serviceID, svc.serviceURL) } } } return results } // Search for UPnP InternetGatewayDevices for seconds, ignoring responses from any devices listed in knownDevices. // The order in which the devices appear in the result list is not deterministic func discover(intf *net.Interface, deviceType string, timeout time.Duration, results chan<- IGD) { ssdp := &net.UDPAddr{IP: []byte{239, 255, 255, 250}, Port: 1900} tpl := `M-SEARCH * HTTP/1.1 HOST: 239.255.255.250:1900 ST: %s MAN: "ssdp:discover" MX: %d USER-AGENT: syncthing/1.0 ` searchStr := fmt.Sprintf(tpl, deviceType, timeout/time.Second) search := []byte(strings.Replace(searchStr, "\n", "\r\n", -1)) l.Debugln("Starting discovery of device type", deviceType, "on", intf.Name) socket, err := net.ListenMulticastUDP("udp4", intf, &net.UDPAddr{IP: ssdp.IP}) if err != nil { l.Debugln(err) return } defer socket.Close() // Make sure our socket gets closed err = socket.SetDeadline(time.Now().Add(timeout)) if err != nil { l.Infoln(err) return } l.Debugln("Sending search request for device type", deviceType, "on", intf.Name) _, err = socket.WriteTo(search, ssdp) if err != nil { l.Infoln(err) return } l.Debugln("Listening for UPnP response for device type", deviceType, "on", intf.Name) // Listen for responses until a timeout is reached for { resp := make([]byte, 65536) n, _, err := socket.ReadFrom(resp) if err != nil { if e, ok := err.(net.Error); !ok || !e.Timeout() { l.Infoln("UPnP read:", err) //legitimate error, not a timeout. } break } igd, err := parseResponse(deviceType, resp[:n]) if err != nil { l.Infoln("UPnP parse:", err) continue } results <- igd } l.Debugln("Discovery for device type", deviceType, "on", intf.Name, "finished.") } func parseResponse(deviceType string, resp []byte) (IGD, error) { l.Debugln("Handling UPnP response:\n\n" + string(resp)) reader := bufio.NewReader(bytes.NewBuffer(resp)) request := &http.Request{} response, err := http.ReadResponse(reader, request) if err != nil { return IGD{}, err } respondingDeviceType := response.Header.Get("St") if respondingDeviceType != deviceType { return IGD{}, errors.New("unrecognized UPnP device of type " + respondingDeviceType) } deviceDescriptionLocation := response.Header.Get("Location") if deviceDescriptionLocation == "" { return IGD{}, errors.New("invalid IGD response: no location specified") } deviceDescriptionURL, err := url.Parse(deviceDescriptionLocation) if err != nil { l.Infoln("Invalid IGD location: " + err.Error()) } deviceUSN := response.Header.Get("USN") if deviceUSN == "" { return IGD{}, errors.New("invalid IGD response: USN not specified") } deviceUUID := strings.TrimPrefix(strings.Split(deviceUSN, "::")[0], "uuid:") matched, err := regexp.MatchString("[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12}", deviceUUID) if !matched { l.Infoln("Invalid IGD response: invalid device UUID", deviceUUID, "(continuing anyway)") } response, err = http.Get(deviceDescriptionLocation) if err != nil { return IGD{}, err } defer response.Body.Close() if response.StatusCode >= 400 { return IGD{}, errors.New("bad status code:" + response.Status) } var upnpRoot upnpRoot err = xml.NewDecoder(response.Body).Decode(&upnpRoot) if err != nil { return IGD{}, err } services, err := getServiceDescriptions(deviceDescriptionLocation, upnpRoot.Device) if err != nil { return IGD{}, err } // Figure out our IP number, on the network used to reach the IGD. // We do this in a fairly roundabout way by connecting to the IGD and // checking the address of the local end of the socket. I'm open to // suggestions on a better way to do this... localIPAddress, err := localIP(deviceDescriptionURL) if err != nil { return IGD{}, err } return IGD{ uuid: deviceUUID, friendlyName: upnpRoot.Device.FriendlyName, url: deviceDescriptionURL, services: services, localIPAddress: localIPAddress, }, nil } func localIP(url *url.URL) (string, error) { conn, err := dialer.Dial("tcp", url.Host) if err != nil { return "", err } defer conn.Close() localIPAddress, _, err := net.SplitHostPort(conn.LocalAddr().String()) if err != nil { return "", err } return localIPAddress, nil } func getChildDevices(d upnpDevice, deviceType string) []upnpDevice { var result []upnpDevice for _, dev := range d.Devices { if dev.DeviceType == deviceType { result = append(result, dev) } } return result } func getChildServices(d upnpDevice, serviceType string) []upnpService { var result []upnpService for _, svc := range d.Services { if svc.ServiceType == serviceType { result = append(result, svc) } } return result } func getServiceDescriptions(rootURL string, device upnpDevice) ([]IGDService, error) { var result []IGDService if device.DeviceType == "urn:schemas-upnp-org:device:InternetGatewayDevice:1" { descriptions := getIGDServices(rootURL, device, "urn:schemas-upnp-org:device:WANDevice:1", "urn:schemas-upnp-org:device:WANConnectionDevice:1", []string{"urn:schemas-upnp-org:service:WANIPConnection:1", "urn:schemas-upnp-org:service:WANPPPConnection:1"}) result = append(result, descriptions...) } else if device.DeviceType == "urn:schemas-upnp-org:device:InternetGatewayDevice:2" { descriptions := getIGDServices(rootURL, device, "urn:schemas-upnp-org:device:WANDevice:2", "urn:schemas-upnp-org:device:WANConnectionDevice:2", []string{"urn:schemas-upnp-org:service:WANIPConnection:2", "urn:schemas-upnp-org:service:WANPPPConnection:2"}) result = append(result, descriptions...) } else { return result, errors.New("[" + rootURL + "] Malformed root device description: not an InternetGatewayDevice.") } if len(result) < 1 { return result, errors.New("[" + rootURL + "] Malformed device description: no compatible service descriptions found.") } return result, nil } func getIGDServices(rootURL string, device upnpDevice, wanDeviceURN string, wanConnectionURN string, serviceURNs []string) []IGDService { var result []IGDService devices := getChildDevices(device, wanDeviceURN) if len(devices) < 1 { l.Infoln(rootURL, "- malformed InternetGatewayDevice description: no WANDevices specified.") return result } for _, device := range devices { connections := getChildDevices(device, wanConnectionURN) if len(connections) < 1 { l.Infoln(rootURL, "- malformed ", wanDeviceURN, "description: no WANConnectionDevices specified.") } for _, connection := range connections { for _, serviceURN := range serviceURNs { services := getChildServices(connection, serviceURN) l.Debugln(rootURL, "- no services of type", serviceURN, " found on connection.") for _, service := range services { if len(service.ControlURL) == 0 { l.Infoln(rootURL+"- malformed", service.ServiceType, "description: no control URL.") } else { u, _ := url.Parse(rootURL) replaceRawPath(u, service.ControlURL) l.Debugln(rootURL, "- found", service.ServiceType, "with URL", u) service := IGDService{serviceID: service.ServiceID, serviceURL: u.String(), serviceURN: service.ServiceType} result = append(result, service) } } } } } return result } func replaceRawPath(u *url.URL, rp string) { asURL, err := url.Parse(rp) if err != nil { return } else if asURL.IsAbs() { u.Path = asURL.Path u.RawQuery = asURL.RawQuery } else { var p, q string fs := strings.Split(rp, "?") p = fs[0] if len(fs) > 1 { q = fs[1] } if p[0] == '/' { u.Path = p } else { u.Path += p } u.RawQuery = q } } func soapRequest(url, service, function, message string) ([]byte, error) { tpl := ` %s ` var resp []byte body := fmt.Sprintf(tpl, message) req, err := http.NewRequest("POST", url, strings.NewReader(body)) if err != nil { return resp, err } req.Close = true req.Header.Set("Content-Type", `text/xml; charset="utf-8"`) req.Header.Set("User-Agent", "syncthing/1.0") req.Header["SOAPAction"] = []string{fmt.Sprintf(`"%s#%s"`, service, function)} // Enforce capitalization in header-entry for sensitive routers. See issue #1696 req.Header.Set("Connection", "Close") req.Header.Set("Cache-Control", "no-cache") req.Header.Set("Pragma", "no-cache") l.Debugln("SOAP Request URL: " + url) l.Debugln("SOAP Action: " + req.Header.Get("SOAPAction")) l.Debugln("SOAP Request:\n\n" + body) r, err := http.DefaultClient.Do(req) if err != nil { l.Debugln(err) return resp, err } resp, _ = ioutil.ReadAll(r.Body) l.Debugf("SOAP Response: %s\n\n%s\n\n", r.Status, resp) r.Body.Close() if r.StatusCode >= 400 { return resp, errors.New(function + ": " + r.Status) } return resp, nil } // AddPortMapping adds a port mapping to all relevant services on the // specified InternetGatewayDevice. Port mapping will fail and return an error // if action is fails for _any_ of the relevant services. For this reason, it // is generally better to configure port mapping for each individual service // instead. func (n *IGD) AddPortMapping(protocol Protocol, externalPort, internalPort int, description string, timeout int) error { for _, service := range n.services { err := service.AddPortMapping(n.localIPAddress, protocol, externalPort, internalPort, description, timeout) if err != nil { return err } } return nil } // DeletePortMapping deletes a port mapping from all relevant services on the // specified InternetGatewayDevice. Port mapping will fail and return an error // if action is fails for _any_ of the relevant services. For this reason, it // is generally better to configure port mapping for each individual service // instead. func (n *IGD) DeletePortMapping(protocol Protocol, externalPort int) error { for _, service := range n.services { err := service.DeletePortMapping(protocol, externalPort) if err != nil { return err } } return nil } type soapGetExternalIPAddressResponseEnvelope struct { XMLName xml.Name Body soapGetExternalIPAddressResponseBody `xml:"Body"` } type soapGetExternalIPAddressResponseBody struct { XMLName xml.Name GetExternalIPAddressResponse getExternalIPAddressResponse `xml:"GetExternalIPAddressResponse"` } type getExternalIPAddressResponse struct { NewExternalIPAddress string `xml:"NewExternalIPAddress"` } type soapErrorResponse struct { ErrorCode int `xml:"Body>Fault>detail>UPnPError>errorCode"` ErrorDescription string `xml:"Body>Fault>detail>UPnPError>errorDescription"` } // AddPortMapping adds a port mapping to the specified IGD service. func (s *IGDService) AddPortMapping(localIPAddress string, protocol Protocol, externalPort, internalPort int, description string, timeout int) error { tpl := ` %d %s %d %s 1 %s %d ` body := fmt.Sprintf(tpl, s.serviceURN, externalPort, protocol, internalPort, localIPAddress, description, timeout) response, err := soapRequest(s.serviceURL, s.serviceURN, "AddPortMapping", body) if err != nil && timeout > 0 { // Try to repair error code 725 - OnlyPermanentLeasesSupported envelope := &soapErrorResponse{} if unmarshalErr := xml.Unmarshal(response, envelope); unmarshalErr != nil { return unmarshalErr } if envelope.ErrorCode == 725 { return s.AddPortMapping(localIPAddress, protocol, externalPort, internalPort, description, 0) } } return err } // DeletePortMapping deletes a port mapping from the specified IGD service. func (s *IGDService) DeletePortMapping(protocol Protocol, externalPort int) error { tpl := ` %d %s ` body := fmt.Sprintf(tpl, s.serviceURN, externalPort, protocol) _, err := soapRequest(s.serviceURL, s.serviceURN, "DeletePortMapping", body) if err != nil { return err } return nil } // GetExternalIPAddress queries the IGD service for its external IP address. // Returns nil if the external IP address is invalid or undefined, along with // any relevant errors func (s *IGDService) GetExternalIPAddress() (net.IP, error) { tpl := `` body := fmt.Sprintf(tpl, s.serviceURN) response, err := soapRequest(s.serviceURL, s.serviceURN, "GetExternalIPAddress", body) if err != nil { return nil, err } envelope := &soapGetExternalIPAddressResponseEnvelope{} err = xml.Unmarshal(response, envelope) if err != nil { return nil, err } result := net.ParseIP(envelope.Body.GetExternalIPAddressResponse.NewExternalIPAddress) return result, nil }