1 files changed, 56 insertions, 34 deletions

diff --git a/src/pkg/rpc/server.go b/src/pkg/rpc/server.go
index 91e9cd5c8..9dcda4148 100644
--- a/src/pkg/rpc/server.go
+++ b/src/pkg/rpc/server.go
@@ -299,10 +299,10 @@ func (server *Server) register(rcvr interface{}, name string, useName bool) os.E
 
 // A value sent as a placeholder for the response when the server receives an invalid request.
 type InvalidRequest struct {
-	marker int
+	Marker int
 }
 
-var invalidRequest = InvalidRequest{1}
+var invalidRequest = InvalidRequest{}
 
 func _new(t *reflect.PtrType) *reflect.PtrValue {
 	v := reflect.MakeZero(t).(*reflect.PtrValue)
@@ -316,6 +316,7 @@ func sendResponse(sending *sync.Mutex, req *Request, reply interface{}, codec Se
 	resp.ServiceMethod = req.ServiceMethod
 	if errmsg != "" {
 		resp.Error = errmsg
+		reply = invalidRequest
 	}
 	resp.Seq = req.Seq
 	sending.Lock()
@@ -389,54 +390,74 @@ func (server *Server) ServeConn(conn io.ReadWriteCloser) {
 func (server *Server) ServeCodec(codec ServerCodec) {
 	sending := new(sync.Mutex)
 	for {
-		// Grab the request header.
-		req := new(Request)
-		err := codec.ReadRequestHeader(req)
+		req, service, mtype, err := server.readRequest(codec)
 		if err != nil {
+			if err != os.EOF {
+				log.Println("rpc:", err)
+			}
 			if err == os.EOF || err == io.ErrUnexpectedEOF {
-				if err == io.ErrUnexpectedEOF {
-					log.Println("rpc:", err)
-				}
 				break
 			}
-			s := "rpc: server cannot decode request: " + err.String()
-			sendResponse(sending, req, invalidRequest, codec, s)
-			break
-		}
-		serviceMethod := strings.Split(req.ServiceMethod, ".", -1)
-		if len(serviceMethod) != 2 {
-			s := "rpc: service/method request ill-formed: " + req.ServiceMethod
-			sendResponse(sending, req, invalidRequest, codec, s)
-			continue
-		}
-		// Look up the request.
-		server.Lock()
-		service, ok := server.serviceMap[serviceMethod[0]]
-		server.Unlock()
-		if !ok {
-			s := "rpc: can't find service " + req.ServiceMethod
-			sendResponse(sending, req, invalidRequest, codec, s)
-			continue
-		}
-		mtype, ok := service.method[serviceMethod[1]]
-		if !ok {
-			s := "rpc: can't find method " + req.ServiceMethod
-			sendResponse(sending, req, invalidRequest, codec, s)
+			// discard body
+			codec.ReadRequestBody(nil)
+
+			// send a response if we actually managed to read a header.
+			if req != nil {
+				sendResponse(sending, req, invalidRequest, codec, err.String())
+			}
 			continue
 		}
+
 		// Decode the argument value.
 		argv := _new(mtype.ArgType)
 		replyv := _new(mtype.ReplyType)
 		err = codec.ReadRequestBody(argv.Interface())
 		if err != nil {
-			log.Println("rpc: tearing down", serviceMethod[0], "connection:", err)
+			if err == os.EOF || err == io.ErrUnexpectedEOF {
+				if err == io.ErrUnexpectedEOF {
+					log.Println("rpc:", err)
+				}
+				break
+			}
 			sendResponse(sending, req, replyv.Interface(), codec, err.String())
-			break
+			continue
 		}
 		go service.call(sending, mtype, req, argv, replyv, codec)
 	}
 	codec.Close()
 }
+func (server *Server) readRequest(codec ServerCodec) (req *Request, service *service, mtype *methodType, err os.Error) {
+	// Grab the request header.
+	req = new(Request)
+	err = codec.ReadRequestHeader(req)
+	if err != nil {
+		req = nil
+		if err == os.EOF || err == io.ErrUnexpectedEOF {
+			return
+		}
+		err = os.ErrorString("rpc: server cannot decode request: " + err.String())
+		return
+	}
+
+	serviceMethod := strings.Split(req.ServiceMethod, ".", -1)
+	if len(serviceMethod) != 2 {
+		err = os.ErrorString("rpc: service/method request ill-formed: " + req.ServiceMethod)
+		return
+	}
+	// Look up the request.
+	server.Lock()
+	service = server.serviceMap[serviceMethod[0]]
+	server.Unlock()
+	if service == nil {
+		err = os.ErrorString("rpc: can't find service " + req.ServiceMethod)
+		return
+	}
+	mtype = service.method[serviceMethod[1]]
+	if mtype == nil {
+		err = os.ErrorString("rpc: can't find method " + req.ServiceMethod)
+	}
+	return
+}
 
 // Accept accepts connections on the listener and serves requests
 // for each incoming connection.  Accept blocks; the caller typically
@@ -465,7 +486,8 @@ func RegisterName(name string, rcvr interface{}) os.Error {
 // The server calls ReadRequestHeader and ReadRequestBody in pairs
 // to read requests from the connection, and it calls WriteResponse to
 // write a response back.  The server calls Close when finished with the
-// connection.
+// connection. ReadRequestBody may be called with a nil
+// argument to force the body of the request to be read and discarded.
 type ServerCodec interface {
 	ReadRequestHeader(*Request) os.Error
 	ReadRequestBody(interface{}) os.Error