mirror of https://github.com/ethereum/go-ethereum
The JSON-RPC server wraps TCP connections in order to be able to shut down them down when RPC is stopped. This is rather scary code. Go 1.3 introduced the http.Server.ConnState hook for such purposes. We can use this facility now that we depend on Go 1.4. There are multiple reasons for the switch apart from making the code less scary: * the TCP listener no longer ticks every second to check a channel * pending requests are allowed to finish after stopping the server * we can time out idle keep-alive connectionspull/1574/head
Felix Lange
9 years ago
parent
97cdf84899
commit
ba14957cf3
@ -1,182 +0,0 @@ |
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// Copyright 2015 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package comms |
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import ( |
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"encoding/json" |
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"fmt" |
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"io" |
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"io/ioutil" |
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"net" |
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"net/http" |
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"time" |
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"github.com/ethereum/go-ethereum/logger" |
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"github.com/ethereum/go-ethereum/logger/glog" |
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"github.com/ethereum/go-ethereum/rpc/codec" |
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"github.com/ethereum/go-ethereum/rpc/shared" |
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) |
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// When https://github.com/golang/go/issues/4674 is implemented this could be replaced
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type stoppableTCPListener struct { |
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*net.TCPListener |
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stop chan struct{} // closed when the listener must stop
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} |
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func newStoppableTCPListener(addr string) (*stoppableTCPListener, error) { |
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wl, err := net.Listen("tcp", addr) |
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if err != nil { |
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return nil, err |
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} |
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if tcpl, ok := wl.(*net.TCPListener); ok { |
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stop := make(chan struct{}) |
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return &stoppableTCPListener{tcpl, stop}, nil |
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} |
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return nil, fmt.Errorf("Unable to create TCP listener for RPC service") |
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} |
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// Stop the listener and all accepted and still active connections.
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func (self *stoppableTCPListener) Stop() { |
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close(self.stop) |
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} |
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func (self *stoppableTCPListener) Accept() (net.Conn, error) { |
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for { |
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self.SetDeadline(time.Now().Add(time.Duration(1 * time.Second))) |
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c, err := self.TCPListener.AcceptTCP() |
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select { |
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case <-self.stop: |
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if c != nil { // accept timeout
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c.Close() |
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} |
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self.TCPListener.Close() |
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return nil, listenerStoppedError |
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default: |
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} |
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if err != nil { |
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if netErr, ok := err.(net.Error); ok && netErr.Timeout() && netErr.Temporary() { |
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continue // regular timeout
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} |
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} |
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return &closableConnection{c, self.stop}, err |
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} |
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} |
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type closableConnection struct { |
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*net.TCPConn |
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closed chan struct{} |
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} |
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func (self *closableConnection) Read(b []byte) (n int, err error) { |
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select { |
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case <-self.closed: |
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self.TCPConn.Close() |
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return 0, io.EOF |
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default: |
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return self.TCPConn.Read(b) |
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} |
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} |
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// Wraps the default handler and checks if the RPC service was stopped. In that case it returns an
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// error indicating that the service was stopped. This will only happen for connections which are
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// kept open (HTTP keep-alive) when the RPC service was shutdown.
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func newStoppableHandler(h http.Handler, stop chan struct{}) http.Handler { |
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return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { |
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select { |
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case <-stop: |
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w.Header().Set("Content-Type", "application/json") |
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err := fmt.Errorf("RPC service stopped") |
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response := shared.NewRpcResponse(-1, shared.JsonRpcVersion, nil, err) |
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httpSend(w, response) |
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default: |
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h.ServeHTTP(w, r) |
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} |
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}) |
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} |
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func httpSend(writer io.Writer, v interface{}) (n int, err error) { |
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var payload []byte |
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payload, err = json.MarshalIndent(v, "", "\t") |
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if err != nil { |
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glog.V(logger.Error).Infoln("Error marshalling JSON", err) |
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return 0, err |
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} |
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glog.V(logger.Detail).Infof("Sending payload: %s", payload) |
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return writer.Write(payload) |
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} |
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func gethHttpHandler(codec codec.Codec, a shared.EthereumApi) http.Handler { |
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return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) { |
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w.Header().Set("Content-Type", "application/json") |
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// Limit request size to resist DoS
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if req.ContentLength > maxHttpSizeReqLength { |
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err := fmt.Errorf("Request too large") |
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response := shared.NewRpcErrorResponse(-1, shared.JsonRpcVersion, -32700, err) |
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httpSend(w, &response) |
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return |
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} |
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defer req.Body.Close() |
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payload, err := ioutil.ReadAll(req.Body) |
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if err != nil { |
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err := fmt.Errorf("Could not read request body") |
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response := shared.NewRpcErrorResponse(-1, shared.JsonRpcVersion, -32700, err) |
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httpSend(w, &response) |
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return |
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} |
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c := codec.New(nil) |
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var rpcReq shared.Request |
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if err = c.Decode(payload, &rpcReq); err == nil { |
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reply, err := a.Execute(&rpcReq) |
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res := shared.NewRpcResponse(rpcReq.Id, rpcReq.Jsonrpc, reply, err) |
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httpSend(w, &res) |
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return |
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} |
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var reqBatch []shared.Request |
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if err = c.Decode(payload, &reqBatch); err == nil { |
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resBatch := make([]*interface{}, len(reqBatch)) |
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resCount := 0 |
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for i, rpcReq := range reqBatch { |
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reply, err := a.Execute(&rpcReq) |
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if rpcReq.Id != nil { // this leaves nil entries in the response batch for later removal
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resBatch[i] = shared.NewRpcResponse(rpcReq.Id, rpcReq.Jsonrpc, reply, err) |
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resCount += 1 |
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} |
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} |
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// make response omitting nil entries
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resBatch = resBatch[:resCount] |
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httpSend(w, resBatch) |
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return |
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} |
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// invalid request
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err = fmt.Errorf("Could not decode request") |
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res := shared.NewRpcErrorResponse(-1, shared.JsonRpcVersion, -32600, err) |
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httpSend(w, res) |
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}) |
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} |
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