Add --rpclisten that behaves frighteningly similar to --listen.

Except it works for the rpcserver instead of the main server.

Closes #34

config.go

@@ -53,7 +53,7 @@ type config struct {
 	BanDuration        time.Duration `long:"banduration" description:"How long to ban misbehaving peers.  Valid time units are {s, m, h}.  Minimum 1 second"`
 	RPCUser            string        `short:"u" long:"rpcuser" description:"Username for RPC connections"`
 	RPCPass            string        `short:"P" long:"rpcpass" default-mask:"-" description:"Password for RPC connections"`
-	RPCPort            string        `short:"r" long:"rpcport" description:"Listen for JSON/RPC messages on this port"`
+	RPCListeners       []string      `long:"rpclisten" description:"Listen for RPC connections on this interface/port (default no listening.  default port: 8334, testnet: 18334)"`
 	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"`
 	Proxy              string        `long:"proxy" description:"Connect via SOCKS5 proxy (eg. 127.0.0.1:9050)"`
@@ -147,33 +147,6 @@ func normalizeAddresses(addrs []string, defaultPort string) []string {
 	return removeDuplicateAddresses(addrs)
 }
 
-// cleanListenAddresses returns a new slice with all the passed peer addresses
-// normalized and duplicates removed.
-func cleanListenAddresses(addrs []string) []string {
-	return normalizeAddresses(addrs, activeNetParams.listenPort)
-}
-
-// cleanPeerAddresses returns a new slice with all the passed peer addresses
-// normalized and duplicates removed.
-func cleanPeerAddresses(addrs []string) []string {
-	return normalizeAddresses(addrs, activeNetParams.peerPort)
-}
-
-// updateConfigWithActiveParams update the passed config with parameters
-// from the active net params if the relevant options in the passed config
-// object are the default so options specified by the user on the command line
-// are not overridden.
-func updateConfigWithActiveParams(cfg *config) {
-	// Even though there should only be one default, a duplicate might
-	// have been specified via the config file or CLI options.  So, make
-	// sure to update all default entries rather than only the first one
-	// found.  Duplicates are removed later.
-
-	if cfg.RPCPort == netParams(defaultBtcnet).rpcPort {
-		cfg.RPCPort = activeNetParams.rpcPort
-	}
-}
-
 // filesExists reports whether the named file or directory exists.
 func fileExists(name string) bool {
 	if _, err := os.Stat(name); err != nil {
@@ -200,7 +173,6 @@ func loadConfig() (*config, []string, error) {
 	// Default config.
 	cfg := config{
 		DebugLevel:  defaultLogLevel,
-		RPCPort:     netParams(defaultBtcnet).rpcPort,
 		MaxPeers:    defaultMaxPeers,
 		BanDuration: defaultBanDuration,
 		ConfigFile:  defaultConfigFile,
@@ -268,7 +240,6 @@ func loadConfig() (*config, []string, error) {
 	} else if cfg.RegressionTest {
 		activeNetParams = netParams(btcwire.TestNet)
 	}
-	updateConfigWithActiveParams(&cfg)
 
 	// Validate debug log level.
 	if !validLogLevel(cfg.DebugLevel) {
@@ -363,14 +334,28 @@ func loadConfig() (*config, []string, error) {
 		cfg.DisableRPC = true
 	}
 
-	// Add default port to all listner addresses if needed and remove
+	if len(cfg.RPCListeners) == 0 {
+		cfg.RPCListeners = []string{
+			net.JoinHostPort("", activeNetParams.rpcPort),
+		}
+	}
+
+	// Add default port to all listener addresses if needed and remove
 	// duplicate addresses.
-	cfg.Listeners = cleanListenAddresses(cfg.Listeners)
+	cfg.Listeners = normalizeAddresses(cfg.Listeners,
+		activeNetParams.listenPort)
+
+	// Add default port to all rpc listener addresses if needed and remove
+	// duplicate addresses.
+	cfg.RPCListeners = normalizeAddresses(cfg.RPCListeners,
+		activeNetParams.rpcPort)
 
 	// Add default port to all added peer addresses if needed and remove
 	// duplicate addresses.
-	cfg.AddPeers = cleanPeerAddresses(cfg.AddPeers)
-	cfg.ConnectPeers = cleanPeerAddresses(cfg.ConnectPeers)
+	cfg.AddPeers = normalizeAddresses(cfg.AddPeers,
+		activeNetParams.peerPort)
+	cfg.ConnectPeers = normalizeAddresses(cfg.ConnectPeers,
+		activeNetParams.peerPort)
 
 	return &cfg, remainingArgs, nil
 }

rpcserver.go

@@ -44,7 +44,6 @@ type rpcServer struct {
 	server    *server
 	ws        wsContext
 	wg        sync.WaitGroup
-	rpcport   string
 	username  string
 	password  string
 	listeners []net.Listener
@@ -313,13 +312,12 @@ func (s *rpcServer) Stop() error {
 }
 
 // newRPCServer returns a new instance of the rpcServer struct.
-func newRPCServer(s *server) (*rpcServer, error) {
+func newRPCServer(listenAddrs []string, s *server) (*rpcServer, error) {
 	rpc := rpcServer{
 		server: s,
 		quit:   make(chan int),
 	}
 	// Get values from config
-	rpc.rpcport = cfg.RPCPort
 	rpc.username = cfg.RPCUser
 	rpc.password = cfg.RPCPass
 
@@ -330,24 +328,33 @@ func newRPCServer(s *server) (*rpcServer, error) {
 	rpc.ws.spentNotifications = make(map[btcwire.OutPoint]*list.List)
 	rpc.ws.minedTxNotifications = make(map[btcwire.ShaHash]*list.List)
 
-	// IPv4 listener.
-	var listeners []net.Listener
-	listenAddr4 := net.JoinHostPort("127.0.0.1", rpc.rpcport)
-	listener4, err := net.Listen("tcp4", listenAddr4)
+	// TODO(oga) this code is identical to that in server, should be
+	// factored into something shared.
+	ipv4ListenAddrs, ipv6ListenAddrs, err := parseListeners(listenAddrs)
+	listeners := make([]net.Listener, 0,
+		len(ipv6ListenAddrs)+len(ipv4ListenAddrs))
+	for _, addr := range ipv4ListenAddrs {
+		listener, err := net.Listen("tcp4", addr)
 		if err != nil {
-		log.Errorf("RPCS: Couldn't create listener: %v", err)
-		return nil, err
+			log.Warnf("RPCS: Can't listen on %s: %v", addr,
+				err)
+			continue
+		}
+		listeners = append(listeners, listener)
 	}
-	listeners = append(listeners, listener4)
 
-	// IPv6 listener.
-	listenAddr6 := net.JoinHostPort("::1", rpc.rpcport)
-	listener6, err := net.Listen("tcp6", listenAddr6)
+	for _, addr := range ipv6ListenAddrs {
+		listener, err := net.Listen("tcp6", addr)
 		if err != nil {
-		log.Errorf("RPCS: Couldn't create listener: %v", err)
-		return nil, err
+			log.Warnf("RPCS: Can't listen on %s: %v", addr,
+				err)
+			continue
+		}
+		listeners = append(listeners, listener)
+	}
+	if len(listeners) == 0 {
+		return nil, errors.New("RPCS: No valid listen address")
 	}
-	listeners = append(listeners, listener6)
 
 	rpc.listeners = listeners
 

sample-btcd.conf

@@ -127,7 +127,14 @@
 ; norpc=1
 
 ; The port used to listen for RPC connections.
-; rpcport=8334
+; rpclisten=:8334
+;
+; Listen on a given address on default port.
+; rpclisten=1.2.3.4
+;
+; Listen on a given address and port.
+; rpclisten=1.2.3.4:8335
+;
 
 
 ; ------------------------------------------------------------------------------

server.go

@@ -871,7 +871,7 @@ func newServer(listenAddrs []string, db btcdb.Db, btcnet btcwire.BitcoinNet) (*s
 	s.txMemPool = newTxMemPool(&s)
 
 	if !cfg.DisableRPC {
-		s.rpcServer, err = newRPCServer(&s)
+		s.rpcServer, err = newRPCServer(cfg.RPCListeners, &s)
 		if err != nil {
 			return nil, err
 		}