2 files changed, 86 insertions, 2 deletions

diff --git a/rpc/http.go b/rpc/http.go
index 790442a28..61f8da549 100644
--- a/rpc/http.go
+++ b/rpc/http.go
@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
-	"net"
 	"net/http"
 
 	"github.com/ethereum/go-ethereum/logger"
@@ -15,6 +14,7 @@ import (
 )
 
 var rpclogger = logger.NewLogger("RPC")
+var rpclistener *ControllableTCPListener
 
 const (
 	jsonrpcver       = "2.0"
@@ -22,11 +22,17 @@ const (
 )
 
 func Start(pipe *xeth.XEth, config RpcConfig) error {
-	l, err := net.Listen("tcp", fmt.Sprintf("%s:%d", config.ListenAddress, config.ListenPort))
+	if rpclistener != nil { // listener already running
+		glog.Infoln("RPC listener already running")
+		return fmt.Errorf("RPC already running on %s", rpclistener.Addr().String())
+	}
+
+	l, err := NewControllableTCPListener(fmt.Sprintf("%s:%d", config.ListenAddress, config.ListenPort))
 	if err != nil {
 		rpclogger.Errorf("Can't listen on %s:%d: %v", config.ListenAddress, config.ListenPort, err)
 		return err
 	}
+	rpclistener = l
 
 	var handler http.Handler
 	if len(config.CorsDomain) > 0 {
@@ -45,6 +51,17 @@ func Start(pipe *xeth.XEth, config RpcConfig) error {
 	return nil
 }
 
+func Stop() error {
+	if rpclistener == nil { // listener not running
+		glog.Infoln("RPC listener not running")
+		return nil
+	}
+
+	rpclistener.Stop()
+	rpclistener = nil
+	return nil
+}
+
 // JSONRPC returns a handler that implements the Ethereum JSON-RPC API.
 func JSONRPC(pipe *xeth.XEth) http.Handler {
 	api := NewEthereumApi(pipe)
diff --git a/rpc/types.go b/rpc/types.go
index bc9a46ed5..c7dc2cc9a 100644
--- a/rpc/types.go
+++ b/rpc/types.go
@@ -23,6 +23,10 @@ import (
 	"math/big"
 	"strings"
 
+	"errors"
+	"net"
+	"time"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 )
@@ -257,3 +261,66 @@ type RpcErrorObject struct {
 	Message string `json:"message"`
 	// Data    interface{} `json:"data"`
 }
+
+type ListenerStoppedError struct {
+	msg string
+}
+
+func (self ListenerStoppedError) Timout() bool {
+	return false
+}
+
+func (self ListenerStoppedError) Temporary() bool {
+	return false
+}
+
+func (self ListenerStoppedError) Error() string {
+	return self.msg
+}
+
+type ControllableTCPListener struct {
+	*net.TCPListener
+	stop chan struct{}
+}
+
+var listenerStoppedError ListenerStoppedError
+
+func (self *ControllableTCPListener) Stop() {
+	close(self.stop)
+}
+
+func (self *ControllableTCPListener) Accept() (net.Conn, error) {
+	for {
+		self.SetDeadline(time.Now().Add(time.Duration(500 * time.Millisecond)))
+		c, err := self.TCPListener.AcceptTCP()
+
+		select {
+		case <-self.stop:
+			self.TCPListener.Close()
+			return nil, listenerStoppedError
+		default: // keep on going
+		}
+
+		if err != nil {
+			if netErr, ok := err.(net.Error); ok && netErr.Timeout() && netErr.Temporary() {
+				continue // regular timeout
+			}
+		}
+
+		return c, err
+	}
+}
+
+func NewControllableTCPListener(addr string) (*ControllableTCPListener, error) {
+	wl, err := net.Listen("tcp", addr)
+	if err != nil {
+		return nil, err
+	}
+
+	if tcpl, ok := wl.(*net.TCPListener); ok {
+		l := &ControllableTCPListener{tcpl, make(chan struct{})}
+		return l, nil
+	}
+
+	return nil, errors.New("Unable to create TCP listener for RPC")
+}