Add support for --externalip.

Closes #38

config.go

@@ -67,6 +67,8 @@ type config struct {
 	RPCKey         string        `long:"rpckey" description:"File containing the certificate key"`
 	DisableRPC     bool          `long:"norpc" description:"Disable built-in RPC server -- NOTE: The RPC server is disabled by default if no rpcuser/rpcpass is specified"`
 	DisableDNSSeed bool          `long:"nodnsseed" description:"Disable DNS seeding for peers"`
+	ExternalIPs    []string      `long:"externalip" description:"Add an ip
+	to the list of local addresses we claim to listen on to peers"`
 	Proxy              string `long:"proxy" description:"Connect via SOCKS5 proxy (eg. 127.0.0.1:9050)"`
 	ProxyUser          string `long:"proxyuser" description:"Username for proxy server"`
 	ProxyPass          string `long:"proxypass" default-mask:"-" description:"Password for proxy server"`

server.go

@@ -828,6 +828,28 @@ func newServer(listenAddrs []string, db btcdb.Db, btcnet btcwire.BitcoinNet) (*s
 			return nil, err
 		}
 		listeners = make([]net.Listener, 0, len(ipv4Addrs)+len(ipv6Addrs))
+		discover := true
+		if len(cfg.ExternalIPs) != 0 {
+			discover = false
+			port, err :=
+				strconv.ParseUint(activeNetParams.listenPort,
+					10, 16)
+			if err != nil {
+				srvrLog.Warnf("doubleewteeeff?")
+			}
+
+			for _, sip := range cfg.ExternalIPs {
+				na, err := hostToNetAddress(sip, uint16(port),
+					btcwire.SFNodeNetwork)
+				if err != nil {
+					srvrLog.Warnf("Not adding %s as ip: %v",
+						sip, err)
+					continue
+				}
+
+				amgr.addLocalAddress(na, ManualPrio)
+			}
+		}
 
 		// TODO(oga) nonstandard port...
 		if wildcard {
@@ -846,9 +868,11 @@ func newServer(listenAddrs []string, db btcdb.Db, btcnet btcwire.BitcoinNet) (*s
 				}
 				na := btcwire.NewNetAddressIPPort(ip,
 					uint16(port), btcwire.SFNodeNetwork)
+				if discover {
 					amgr.addLocalAddress(na, InterfacePrio)
 				}
 			}
+		}
 	nowc:
 
 		for _, addr := range ipv4Addrs {
@@ -860,10 +884,12 @@ func newServer(listenAddrs []string, db btcdb.Db, btcnet btcwire.BitcoinNet) (*s
 			}
 			listeners = append(listeners, listener)
 
+			if discover {
 				if na, err := deserialiseNetAddress(addr); err == nil {
 					amgr.addLocalAddress(na, BoundPrio)
 				}
 			}
+		}
 
 		for _, addr := range ipv6Addrs {
 			listener, err := net.Listen("tcp6", addr)
@@ -873,10 +899,12 @@ func newServer(listenAddrs []string, db btcdb.Db, btcnet btcwire.BitcoinNet) (*s
 				continue
 			}
 			listeners = append(listeners, listener)
+			if discover {
 				if na, err := deserialiseNetAddress(addr); err == nil {
 					amgr.addLocalAddress(na, BoundPrio)
 				}
 			}
+		}
 
 		if len(listeners) == 0 {
 			return nil, errors.New("No valid listen address")