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-rw-r--r--p2p/nat/nat.go235
-rw-r--r--p2p/nat/natpmp.go115
-rw-r--r--p2p/nat/natupnp.go149
3 files changed, 499 insertions, 0 deletions
diff --git a/p2p/nat/nat.go b/p2p/nat/nat.go
new file mode 100644
index 000000000..12d355ba1
--- /dev/null
+++ b/p2p/nat/nat.go
@@ -0,0 +1,235 @@
+// Package nat provides access to common port mapping protocols.
+package nat
+
+import (
+ "errors"
+ "fmt"
+ "net"
+ "strings"
+ "sync"
+ "time"
+
+ "github.com/ethereum/go-ethereum/logger"
+ "github.com/jackpal/go-nat-pmp"
+)
+
+var log = logger.NewLogger("P2P NAT")
+
+// An implementation of nat.Interface can map local ports to ports
+// accessible from the Internet.
+type Interface interface {
+ // These methods manage a mapping between a port on the local
+ // machine to a port that can be connected to from the internet.
+ //
+ // protocol is "UDP" or "TCP". Some implementations allow setting
+ // a display name for the mapping. The mapping may be removed by
+ // the gateway when its lifetime ends.
+ AddMapping(protocol string, extport, intport int, name string, lifetime time.Duration) error
+ DeleteMapping(protocol string, extport, intport int) error
+
+ // This method should return the external (Internet-facing)
+ // address of the gateway device.
+ ExternalIP() (net.IP, error)
+
+ // Should return name of the method. This is used for logging.
+ String() string
+}
+
+// Parse parses a NAT interface description.
+// The following formats are currently accepted.
+// Note that mechanism names are not case-sensitive.
+//
+// "" or "none" return nil
+// "extip:77.12.33.4" will assume the local machine is reachable on the given IP
+// "any" uses the first auto-detected mechanism
+// "upnp" uses the Universal Plug and Play protocol
+// "pmp" uses NAT-PMP with an auto-detected gateway address
+// "pmp:192.168.0.1" uses NAT-PMP with the given gateway address
+func Parse(spec string) (Interface, error) {
+ var (
+ parts = strings.SplitN(spec, ":", 2)
+ mech = strings.ToLower(parts[0])
+ ip net.IP
+ )
+ if len(parts) > 1 {
+ ip = net.ParseIP(parts[1])
+ if ip == nil {
+ return nil, errors.New("invalid IP address")
+ }
+ }
+ switch mech {
+ case "", "none", "off":
+ return nil, nil
+ case "any", "auto", "on":
+ return Any(), nil
+ case "extip", "ip":
+ if ip == nil {
+ return nil, errors.New("missing IP address")
+ }
+ return ExtIP(ip), nil
+ case "upnp":
+ return UPnP(), nil
+ case "pmp", "natpmp", "nat-pmp":
+ return PMP(ip), nil
+ default:
+ return nil, fmt.Errorf("unknown mechanism %q", parts[0])
+ }
+}
+
+const (
+ mapTimeout = 20 * time.Minute
+ mapUpdateInterval = 15 * time.Minute
+)
+
+// Map adds a port mapping on m and keeps it alive until c is closed.
+// This function is typically invoked in its own goroutine.
+func Map(m Interface, c chan struct{}, protocol string, extport, intport int, name string) {
+ refresh := time.NewTimer(mapUpdateInterval)
+ defer func() {
+ refresh.Stop()
+ log.Debugf("Deleting port mapping: %s %d -> %d (%s) using %s\n", protocol, extport, intport, name, m)
+ m.DeleteMapping(protocol, extport, intport)
+ }()
+ log.Debugf("add mapping: %s %d -> %d (%s) using %s\n", protocol, extport, intport, name, m)
+ if err := m.AddMapping(protocol, intport, extport, name, mapTimeout); err != nil {
+ log.Errorf("mapping error: %v\n", err)
+ }
+ for {
+ select {
+ case _, ok := <-c:
+ if !ok {
+ return
+ }
+ case <-refresh.C:
+ log.DebugDetailf("refresh mapping: %s %d -> %d (%s) using %s\n", protocol, extport, intport, name, m)
+ if err := m.AddMapping(protocol, intport, extport, name, mapTimeout); err != nil {
+ log.Errorf("mapping error: %v\n", err)
+ }
+ refresh.Reset(mapUpdateInterval)
+ }
+ }
+}
+
+// ExtIP assumes that the local machine is reachable on the given
+// external IP address, and that any required ports were mapped manually.
+// Mapping operations will not return an error but won't actually do anything.
+func ExtIP(ip net.IP) Interface {
+ if ip == nil {
+ panic("IP must not be nil")
+ }
+ return extIP(ip)
+}
+
+type extIP net.IP
+
+func (n extIP) ExternalIP() (net.IP, error) { return net.IP(n), nil }
+func (n extIP) String() string { return fmt.Sprintf("ExtIP(%v)", net.IP(n)) }
+
+// These do nothing.
+func (extIP) AddMapping(string, int, int, string, time.Duration) error { return nil }
+func (extIP) DeleteMapping(string, int, int) error { return nil }
+
+// Any returns a port mapper that tries to discover any supported
+// mechanism on the local network.
+func Any() Interface {
+ // TODO: attempt to discover whether the local machine has an
+ // Internet-class address. Return ExtIP in this case.
+ return startautodisc("UPnP or NAT-PMP", func() Interface {
+ found := make(chan Interface, 2)
+ go func() { found <- discoverUPnP() }()
+ go func() { found <- discoverPMP() }()
+ for i := 0; i < cap(found); i++ {
+ if c := <-found; c != nil {
+ return c
+ }
+ }
+ return nil
+ })
+}
+
+// UPnP returns a port mapper that uses UPnP. It will attempt to
+// discover the address of your router using UDP broadcasts.
+func UPnP() Interface {
+ return startautodisc("UPnP", discoverUPnP)
+}
+
+// PMP returns a port mapper that uses NAT-PMP. The provided gateway
+// address should be the IP of your router. If the given gateway
+// address is nil, PMP will attempt to auto-discover the router.
+func PMP(gateway net.IP) Interface {
+ if gateway != nil {
+ return &pmp{gw: gateway, c: natpmp.NewClient(gateway)}
+ }
+ return startautodisc("NAT-PMP", discoverPMP)
+}
+
+// autodisc represents a port mapping mechanism that is still being
+// auto-discovered. Calls to the Interface methods on this type will
+// wait until the discovery is done and then call the method on the
+// discovered mechanism.
+//
+// This type is useful because discovery can take a while but we
+// want return an Interface value from UPnP, PMP and Auto immediately.
+type autodisc struct {
+ what string
+ done <-chan Interface
+
+ mu sync.Mutex
+ found Interface
+}
+
+func startautodisc(what string, doit func() Interface) Interface {
+ // TODO: monitor network configuration and rerun doit when it changes.
+ done := make(chan Interface)
+ ad := &autodisc{what: what, done: done}
+ go func() { done <- doit(); close(done) }()
+ return ad
+}
+
+func (n *autodisc) AddMapping(protocol string, extport, intport int, name string, lifetime time.Duration) error {
+ if err := n.wait(); err != nil {
+ return err
+ }
+ return n.found.AddMapping(protocol, extport, intport, name, lifetime)
+}
+
+func (n *autodisc) DeleteMapping(protocol string, extport, intport int) error {
+ if err := n.wait(); err != nil {
+ return err
+ }
+ return n.found.DeleteMapping(protocol, extport, intport)
+}
+
+func (n *autodisc) ExternalIP() (net.IP, error) {
+ if err := n.wait(); err != nil {
+ return nil, err
+ }
+ return n.found.ExternalIP()
+}
+
+func (n *autodisc) String() string {
+ n.mu.Lock()
+ defer n.mu.Unlock()
+ if n.found == nil {
+ return n.what
+ } else {
+ return n.found.String()
+ }
+}
+
+func (n *autodisc) wait() error {
+ n.mu.Lock()
+ found := n.found
+ n.mu.Unlock()
+ if found != nil {
+ // already discovered
+ return nil
+ }
+ if found = <-n.done; found == nil {
+ return errors.New("no devices discovered")
+ }
+ n.mu.Lock()
+ n.found = found
+ n.mu.Unlock()
+ return nil
+}
diff --git a/p2p/nat/natpmp.go b/p2p/nat/natpmp.go
new file mode 100644
index 000000000..f249c6073
--- /dev/null
+++ b/p2p/nat/natpmp.go
@@ -0,0 +1,115 @@
+package nat
+
+import (
+ "fmt"
+ "net"
+ "strings"
+ "time"
+
+ "github.com/jackpal/go-nat-pmp"
+)
+
+// natPMPClient adapts the NAT-PMP protocol implementation so it conforms to
+// the common interface.
+type pmp struct {
+ gw net.IP
+ c *natpmp.Client
+}
+
+func (n *pmp) String() string {
+ return fmt.Sprintf("NAT-PMP(%v)", n.gw)
+}
+
+func (n *pmp) ExternalIP() (net.IP, error) {
+ response, err := n.c.GetExternalAddress()
+ if err != nil {
+ return nil, err
+ }
+ return response.ExternalIPAddress[:], nil
+}
+
+func (n *pmp) AddMapping(protocol string, extport, intport int, name string, lifetime time.Duration) error {
+ if lifetime <= 0 {
+ return fmt.Errorf("lifetime must not be <= 0")
+ }
+ // Note order of port arguments is switched between our
+ // AddMapping and the client's AddPortMapping.
+ _, err := n.c.AddPortMapping(strings.ToLower(protocol), intport, extport, int(lifetime/time.Second))
+ return err
+}
+
+func (n *pmp) DeleteMapping(protocol string, extport, intport int) (err error) {
+ // To destroy a mapping, send an add-port with an internalPort of
+ // the internal port to destroy, an external port of zero and a
+ // time of zero.
+ _, err = n.c.AddPortMapping(strings.ToLower(protocol), intport, 0, 0)
+ return err
+}
+
+func discoverPMP() Interface {
+ // run external address lookups on all potential gateways
+ gws := potentialGateways()
+ found := make(chan *pmp, len(gws))
+ for i := range gws {
+ gw := gws[i]
+ go func() {
+ c := natpmp.NewClient(gw)
+ if _, err := c.GetExternalAddress(); err != nil {
+ found <- nil
+ } else {
+ found <- &pmp{gw, c}
+ }
+ }()
+ }
+ // return the one that responds first.
+ // discovery needs to be quick, so we stop caring about
+ // any responses after a very short timeout.
+ timeout := time.NewTimer(1 * time.Second)
+ defer timeout.Stop()
+ for _ = range gws {
+ select {
+ case c := <-found:
+ if c != nil {
+ return c
+ }
+ case <-timeout.C:
+ return nil
+ }
+ }
+ return nil
+}
+
+var (
+ // LAN IP ranges
+ _, lan10, _ = net.ParseCIDR("10.0.0.0/8")
+ _, lan176, _ = net.ParseCIDR("172.16.0.0/12")
+ _, lan192, _ = net.ParseCIDR("192.168.0.0/16")
+)
+
+// TODO: improve this. We currently assume that (on most networks)
+// the router is X.X.X.1 in a local LAN range.
+func potentialGateways() (gws []net.IP) {
+ ifaces, err := net.Interfaces()
+ if err != nil {
+ return nil
+ }
+ for _, iface := range ifaces {
+ ifaddrs, err := iface.Addrs()
+ if err != nil {
+ return gws
+ }
+ for _, addr := range ifaddrs {
+ switch x := addr.(type) {
+ case *net.IPNet:
+ if lan10.Contains(x.IP) || lan176.Contains(x.IP) || lan192.Contains(x.IP) {
+ ip := x.IP.Mask(x.Mask).To4()
+ if ip != nil {
+ ip[3] = ip[3] | 0x01
+ gws = append(gws, ip)
+ }
+ }
+ }
+ }
+ }
+ return gws
+}
diff --git a/p2p/nat/natupnp.go b/p2p/nat/natupnp.go
new file mode 100644
index 000000000..25cbc0d71
--- /dev/null
+++ b/p2p/nat/natupnp.go
@@ -0,0 +1,149 @@
+package nat
+
+import (
+ "errors"
+ "fmt"
+ "net"
+ "strings"
+ "time"
+
+ "github.com/fjl/goupnp"
+ "github.com/fjl/goupnp/dcps/internetgateway1"
+ "github.com/fjl/goupnp/dcps/internetgateway2"
+)
+
+type upnp struct {
+ dev *goupnp.RootDevice
+ service string
+ client upnpClient
+}
+
+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) ExternalIP() (addr net.IP, err error) {
+ ipString, err := n.client.GetExternalIPAddress()
+ 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)
+ 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 {
+ switch x := addr.(type) {
+ case *net.IPNet:
+ if 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.client.DeletePortMapping("", uint16(extport), strings.ToUpper(protocol))
+}
+
+func (n *upnp) String() string {
+ return "UPNP " + n.service
+}
+
+// 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(dev *goupnp.RootDevice, sc goupnp.ServiceClient) *upnp {
+ switch sc.Service.ServiceType {
+ case internetgateway1.URN_WANIPConnection_1:
+ return &upnp{dev, "IGDv1-IP1", &internetgateway1.WANIPConnection1{sc}}
+ case internetgateway1.URN_WANPPPConnection_1:
+ return &upnp{dev, "IGDv1-PPP1", &internetgateway1.WANPPPConnection1{sc}}
+ }
+ return nil
+ })
+ // IGDv2
+ go discover(found, internetgateway2.URN_WANConnectionDevice_2, func(dev *goupnp.RootDevice, sc goupnp.ServiceClient) *upnp {
+ switch sc.Service.ServiceType {
+ case internetgateway2.URN_WANIPConnection_1:
+ return &upnp{dev, "IGDv2-IP1", &internetgateway2.WANIPConnection1{sc}}
+ case internetgateway2.URN_WANIPConnection_2:
+ return &upnp{dev, "IGDv2-IP2", &internetgateway2.WANIPConnection2{sc}}
+ case internetgateway2.URN_WANPPPConnection_1:
+ return &upnp{dev, "IGDv2-PPP1", &internetgateway2.WANPPPConnection1{sc}}
+ }
+ return nil
+ })
+ for i := 0; i < cap(found); i++ {
+ if c := <-found; c != nil {
+ return c
+ }
+ }
+ return nil
+}
+
+func discover(out chan<- *upnp, target string, matcher func(*goupnp.RootDevice, goupnp.ServiceClient) *upnp) {
+ devs, err := goupnp.DiscoverDevices(target)
+ if err != 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{service.NewSOAPClient(), devs[i].Root, service}
+ upnp := matcher(devs[i].Root, sc)
+ if upnp == nil {
+ return
+ }
+ // check whether port mapping is enabled
+ if _, nat, err := upnp.client.GetNATRSIPStatus(); err != nil || !nat {
+ return
+ }
+ out <- upnp
+ found = true
+ })
+ }
+ if !found {
+ out <- nil
+ }
+}
generated by cgit (git 2.34.1) at 2024-11-15 21:57:29 +0800