Add very tentative UPnP NAT traversal

[btrtrc.git] / portfwd.go

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()
+}