pushVersionMessage: fix you/me address generation

The you address is the one we already set up fo the user, so either waht
we connected to (this will work with tor, etc), or the ip the user
connect to us from otherwise. We must however check to see if it is the address
of the proxy and strip it.

The me addesss, we use the same address selection for local addresses as
always

This should mean that we pass our tor address out in the version message
and thus the peers should add us to their addressmanager.

peer.go

@@ -175,23 +175,26 @@ func (p *peer) pushVersionMsg() error {
 		return err
 	}
 
-	// Create a NetAddress for the local IP.  Don't assume any services
-	// until we know otherwise.
-	naMe, err := newNetAddress(p.conn.LocalAddr(), 0)
-	if err != nil {
-		return err
-	}
+	theirNa := p.na
 
-	// Create a NetAddress for the remote IP.  Don't assume any services
-	// until we know otherwise.
-	naYou, err := newNetAddress(p.conn.RemoteAddr(), 0)
-	if err != nil {
-		return err
+	// If we are behind a proxy and the connection comes from the proxy then
+	// we return an unroutable address as their address. This is to prevent
+	// leaking the tor proxy address.
+	if cfg.Proxy != "" {
+		proxyaddress, _, err := net.SplitHostPort(cfg.Proxy)
+		// invalid proxy means poorly configured, be on the safe side.
+		if err != nil || p.na.IP.String() == proxyaddress {
+			theirNa = &btcwire.NetAddress{
+				Timestamp: time.Now(),
+				IP:        net.IP([]byte{0, 0, 0, 0}),
+			}
+		}
 	}
 
 	// Version message.
-	msg := btcwire.NewMsgVersion(naMe, naYou, p.server.nonce, userAgent,
-		int32(blockNum))
+	msg := btcwire.NewMsgVersion(
+		p.server.addrManager.getBestLocalAddress(p.na), theirNa, p.server.nonce,
+		userAgent, int32(blockNum))
 
 	// XXX: bitcoind appears to always enable the full node services flag
 	// of the remote peer netaddress field in the version message regardless