plugeth/p2p/nat/natupnp.go
Felix Lange 1d25039ff5
p2p/nat: limit UPNP request concurrency (#21390)
This adds a lock around requests because some routers can't handle
concurrent requests. Requests are also rate-limited.
 
The Map function request a new mapping exactly when the map timeout
occurs instead of 5 minutes earlier. This should prevent duplicate mappings.
2020-08-05 09:51:37 +02:00

216 lines
5.8 KiB
Go

// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package nat
import (
"errors"
"fmt"
"net"
"strings"
"sync"
"time"
"github.com/huin/goupnp"
"github.com/huin/goupnp/dcps/internetgateway1"
"github.com/huin/goupnp/dcps/internetgateway2"
)
const (
soapRequestTimeout = 3 * time.Second
rateLimit = 200 * time.Millisecond
)
type upnp struct {
dev *goupnp.RootDevice
service string
client upnpClient
mu sync.Mutex
lastReqTime time.Time
}
type upnpClient interface {
GetExternalIPAddress() (string, error)
AddPortMapping(string, uint16, string, uint16, string, bool, string, uint32) error
DeletePortMapping(string, uint16, string) error
GetNATRSIPStatus() (sip bool, nat bool, err error)
}
func (n *upnp) natEnabled() bool {
var ok bool
var err error
n.withRateLimit(func() error {
_, ok, err = n.client.GetNATRSIPStatus()
return err
})
return err == nil && ok
}
func (n *upnp) ExternalIP() (addr net.IP, err error) {
var ipString string
n.withRateLimit(func() error {
ipString, err = n.client.GetExternalIPAddress()
return err
})
if err != nil {
return nil, err
}
ip := net.ParseIP(ipString)
if ip == nil {
return nil, errors.New("bad IP in response")
}
return ip, nil
}
func (n *upnp) AddMapping(protocol string, extport, intport int, desc string, lifetime time.Duration) error {
ip, err := n.internalAddress()
if err != nil {
return nil
}
protocol = strings.ToUpper(protocol)
lifetimeS := uint32(lifetime / time.Second)
n.DeleteMapping(protocol, extport, intport)
return n.withRateLimit(func() error {
return n.client.AddPortMapping("", uint16(extport), protocol, uint16(intport), ip.String(), true, desc, lifetimeS)
})
}
func (n *upnp) internalAddress() (net.IP, error) {
devaddr, err := net.ResolveUDPAddr("udp4", n.dev.URLBase.Host)
if err != nil {
return nil, err
}
ifaces, err := net.Interfaces()
if err != nil {
return nil, err
}
for _, iface := range ifaces {
addrs, err := iface.Addrs()
if err != nil {
return nil, err
}
for _, addr := range addrs {
if x, ok := addr.(*net.IPNet); ok && x.Contains(devaddr.IP) {
return x.IP, nil
}
}
}
return nil, fmt.Errorf("could not find local address in same net as %v", devaddr)
}
func (n *upnp) DeleteMapping(protocol string, extport, intport int) error {
return n.withRateLimit(func() error {
return n.client.DeletePortMapping("", uint16(extport), strings.ToUpper(protocol))
})
}
func (n *upnp) String() string {
return "UPNP " + n.service
}
func (n *upnp) withRateLimit(fn func() error) error {
n.mu.Lock()
defer n.mu.Unlock()
lastreq := time.Since(n.lastReqTime)
if lastreq < rateLimit {
time.Sleep(rateLimit - lastreq)
}
err := fn()
n.lastReqTime = time.Now()
return err
}
// discoverUPnP searches for Internet Gateway Devices
// and returns the first one it can find on the local network.
func discoverUPnP() Interface {
found := make(chan *upnp, 2)
// IGDv1
go discover(found, internetgateway1.URN_WANConnectionDevice_1, func(sc goupnp.ServiceClient) *upnp {
switch sc.Service.ServiceType {
case internetgateway1.URN_WANIPConnection_1:
return &upnp{service: "IGDv1-IP1", client: &internetgateway1.WANIPConnection1{ServiceClient: sc}}
case internetgateway1.URN_WANPPPConnection_1:
return &upnp{service: "IGDv1-PPP1", client: &internetgateway1.WANPPPConnection1{ServiceClient: sc}}
}
return nil
})
// IGDv2
go discover(found, internetgateway2.URN_WANConnectionDevice_2, func(sc goupnp.ServiceClient) *upnp {
switch sc.Service.ServiceType {
case internetgateway2.URN_WANIPConnection_1:
return &upnp{service: "IGDv2-IP1", client: &internetgateway2.WANIPConnection1{ServiceClient: sc}}
case internetgateway2.URN_WANIPConnection_2:
return &upnp{service: "IGDv2-IP2", client: &internetgateway2.WANIPConnection2{ServiceClient: sc}}
case internetgateway2.URN_WANPPPConnection_1:
return &upnp{service: "IGDv2-PPP1", client: &internetgateway2.WANPPPConnection1{ServiceClient: sc}}
}
return nil
})
for i := 0; i < cap(found); i++ {
if c := <-found; c != nil {
return c
}
}
return nil
}
// finds devices matching the given target and calls matcher for all
// advertised services of each device. The first non-nil service found
// is sent into out. If no service matched, nil is sent.
func discover(out chan<- *upnp, target string, matcher func(goupnp.ServiceClient) *upnp) {
devs, err := goupnp.DiscoverDevices(target)
if err != nil {
out <- nil
return
}
found := false
for i := 0; i < len(devs) && !found; i++ {
if devs[i].Root == nil {
continue
}
devs[i].Root.Device.VisitServices(func(service *goupnp.Service) {
if found {
return
}
// check for a matching IGD service
sc := goupnp.ServiceClient{
SOAPClient: service.NewSOAPClient(),
RootDevice: devs[i].Root,
Location: devs[i].Location,
Service: service,
}
sc.SOAPClient.HTTPClient.Timeout = soapRequestTimeout
upnp := matcher(sc)
if upnp == nil {
return
}
upnp.dev = devs[i].Root
// check whether port mapping is enabled
if upnp.natEnabled() {
out <- upnp
found = true
}
})
}
if !found {
out <- nil
}
}