syncthing/lib/upnp/upnp.go

588 lines
16 KiB
Go

// 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 <timeout> 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 := `<?xml version="1.0" ?>
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/" s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
<s:Body>%s</s:Body>
</s:Envelope>
`
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 := `<u:AddPortMapping xmlns:u="%s">
<NewRemoteHost></NewRemoteHost>
<NewExternalPort>%d</NewExternalPort>
<NewProtocol>%s</NewProtocol>
<NewInternalPort>%d</NewInternalPort>
<NewInternalClient>%s</NewInternalClient>
<NewEnabled>1</NewEnabled>
<NewPortMappingDescription>%s</NewPortMappingDescription>
<NewLeaseDuration>%d</NewLeaseDuration>
</u:AddPortMapping>`
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{}
err = xml.Unmarshal(response, envelope)
if err != nil {
return err
}
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 := `<u:DeletePortMapping xmlns:u="%s">
<NewRemoteHost></NewRemoteHost>
<NewExternalPort>%d</NewExternalPort>
<NewProtocol>%s</NewProtocol>
</u:DeletePortMapping>`
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 := `<u:GetExternalIPAddress xmlns:u="%s" />`
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
}