Fix IceAgent improperly returning XorAddress

IceAgent improperly returns XorAddress when finding ports.
This would cause the portManager to fail finding the relevant port
since we are bound on the local (and not our public XorAddress)

Resolves pion#140

pkg/ice/agent.go

@@ -35,11 +35,19 @@ type CandidatePair struct {
 	local  Candidate
 }
 
-// GetAddrs returns network addresses for the candidate pair
-func (c CandidatePair) GetAddrs() (local *stun.TransportAddr, remote *net.UDPAddr) {
+func (c CandidatePair) getAddrs() (local *stun.TransportAddr, remote *net.UDPAddr) {
+	localIP := net.ParseIP(c.local.GetBase().Address)
+	localPort := c.local.GetBase().Port
+
+	switch c := c.local.(type) {
+	case *CandidateSrflx:
+		localIP = net.ParseIP(c.RemoteAddress)
+		localPort = c.RemotePort
+	}
+
 	return &stun.TransportAddr{
-			IP:   net.ParseIP(c.local.GetBase().Address),
-			Port: c.local.GetBase().Port,
+			IP:   localIP,
+			Port: localPort,
 		}, &net.UDPAddr{
 			IP:   net.ParseIP(c.remote.GetBase().Address),
 			Port: c.remote.GetBase().Port,
@@ -364,10 +372,10 @@ func (a *Agent) SelectedPair() (local *stun.TransportAddr, remote *net.UDPAddr)
 
 	if a.selectedPair.remote == nil || a.selectedPair.local == nil {
 		for _, p := range a.validPairs {
-			return p.GetAddrs()
+			return p.getAddrs()
 		}
 		return nil, nil
 	}
 
-	return a.selectedPair.GetAddrs()
+	return a.selectedPair.getAddrs()
 }