Add very tentative UPnP NAT traversal

Relates to #230

diff --git a/client.go b/client.go
index fba0b1e22e020ee95298ffaf05b7c701d2e77cab..ab2fe08d9fc8866b82f93e3c466e9422d42027e9 100644 (file)
--- a/client.go
+++ b/client.go
@@ -303,6 +303,7 @@ func NewClient(cfg *Config) (cl *Client, err error) {
        if err != nil {
                return
        }
+       go cl.forwardPort()
        if cl.tcpListener != nil {
                go cl.acceptConnections(cl.tcpListener, false)
        }

diff --git a/client_test.go b/client_test.go
index 13c6cbddd9811742be45e71786fe69d48119ed11..51f8ad4b70bf951daca7ad1f583470637ea39844 100644 (file)
--- a/client_test.go
+++ b/client_test.go
@@ -33,10 +33,11 @@ import (
 
 func TestingConfig() *Config {
        return &Config{
-               ListenAddr:      "localhost:0",
-               NoDHT:           true,
-               DataDir:         tempDir(),
-               DisableTrackers: true,
+               ListenAddr:              "localhost:0",
+               NoDHT:                   true,
+               DataDir:                 tempDir(),
+               DisableTrackers:         true,
+               NoDefaultPortForwarding: true,
                // Debug:           true,
        }
 }

diff --git a/config.go b/config.go
index cb597b200c7df7b38b9105891a97dc27a639f45e..a8933abaaaeca943cfe55d98a3ea03d55d2b64aa 100644 (file)
--- a/config.go
+++ b/config.go
@@ -33,7 +33,8 @@ type Config struct {
        // The address to listen for new uTP and TCP bittorrent protocol
        // connections. DHT shares a UDP socket with uTP unless configured
        // otherwise.
-       ListenAddr string `long:"listen-addr" value-name:"HOST:PORT"`
+       ListenAddr              string `long:"listen-addr" value-name:"HOST:PORT"`
+       NoDefaultPortForwarding bool
        // Don't announce to trackers. This only leaves DHT to discover peers.
        DisableTrackers bool `long:"disable-trackers"`
        DisablePEX      bool `long:"disable-pex"`

diff --git a/portfwd.go b/portfwd.go
new file mode 100644 (file)
index 0000000..1f1ecd5
--- /dev/null
+++ b/portfwd.go
@@ -0,0 +1,41 @@
+package torrent
+
+import (
+       "log"
+       "time"
+
+       flog "github.com/anacrolix/log"
+
+       "github.com/syncthing/syncthing/lib/nat"
+       "github.com/syncthing/syncthing/lib/upnp"
+)
+
+func addPortMapping(d nat.Device, proto nat.Protocol, internalPort int, debug bool) {
+       externalPort, err := d.AddPortMapping(proto, internalPort, internalPort, "anacrolix/torrent", 0)
+       if err != nil {
+               log.Printf("error adding %s port mapping: %s", proto, err)
+       } else if externalPort != internalPort {
+               log.Printf("external port %d does not match internal port %d in port mapping", externalPort, internalPort)
+       } else if debug {
+               log.Printf("forwarded external %s port %d", proto, externalPort)
+       }
+}
+
+func (cl *Client) forwardPort() {
+       cl.mu.Lock()
+       defer cl.mu.Unlock()
+       if cl.config.NoDefaultPortForwarding {
+               return
+       }
+       cl.mu.Unlock()
+       ds := upnp.Discover(0, 2*time.Second)
+       cl.mu.Lock()
+       flog.Default.Emit(flog.Fmsg("discovered %d upnp devices", len(ds)))
+       port := cl.incomingPeerPort()
+       cl.mu.Unlock()
+       for _, d := range ds {
+               go addPortMapping(d, nat.TCP, port, cl.config.Debug)
+               go addPortMapping(d, nat.UDP, port, cl.config.Debug)
+       }
+       cl.mu.Lock()
+}