path: root/rpc/ws/server.go

/*
  This file is part of go-ethereum

  go-ethereum is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  go-ethereum is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with go-ethereum.  If not, see <http://www.gnu.org/licenses/>.
*/
package rpcws

import (
    "fmt"
    "net"
    "net/http"

    "github.com/ethereum/go-ethereum/logger"
    "github.com/ethereum/go-ethereum/rpc"
    "github.com/ethereum/go-ethereum/xeth"
    "golang.org/x/net/websocket"
)

var wslogger = logger.NewLogger("RPC-WS")
var JSON rpc.JsonWrapper

type WebSocketServer struct {
    pipe     *xeth.XEth
    port     int
    doneCh   chan bool
    listener net.Listener
}

func NewWebSocketServer(pipe *xeth.XEth, port int) (*WebSocketServer, error) {
    sport := fmt.Sprintf(":%d", port)
    l, err := net.Listen("tcp", sport)
    if err != nil {
        return nil, err
    }

    return &WebSocketServer{
        pipe,
        port,
        make(chan bool),
        l,
    }, nil
}

func (self *WebSocketServer) handlerLoop() {
    for {
        select {
        case <-self.doneCh:
            wslogger.Infoln("Shutdown RPC-WS server")
            return
        }
    }
}

func (self *WebSocketServer) Stop() {
    close(self.doneCh)
}

func (self *WebSocketServer) Start() {
    wslogger.Infof("Starting RPC-WS server on port %d", self.port)
    go self.handlerLoop()

    api := rpc.NewEthereumApi(self.pipe)
    h := self.apiHandler(api)
    http.Handle("/ws", h)

    err := http.Serve(self.listener, nil)
    if err != nil {
        wslogger.Errorln("Error on RPC-WS interface:", err)
    }
}

func (s *WebSocketServer) apiHandler(api *rpc.EthereumApi) http.Handler {
    fn := func(w http.ResponseWriter, req *http.Request) {
        h := sockHandler(api)
        s := websocket.Server{Handler: h}
        s.ServeHTTP(w, req)
    }

    return http.HandlerFunc(fn)
}

func sockHandler(api *rpc.EthereumApi) websocket.Handler {
    var jsonrpcver string = "2.0"
    fn := func(conn *websocket.Conn) {
        for {
            wslogger.Debugln("Handling connection")
            var reqParsed rpc.RpcRequest

            // reqParsed, reqerr := JSON.ParseRequestBody(conn.Request())
            if err := websocket.JSON.Receive(conn, &reqParsed); err != nil {
                jsonerr := &rpc.RpcErrorObject{-32700, rpc.ErrorParseRequest}
                JSON.Send(conn, &rpc.RpcErrorResponse{JsonRpc: jsonrpcver, ID: nil, Error: jsonerr})
                continue
            }

            var response interface{}
            reserr := api.GetRequestReply(&reqParsed, &response)
            if reserr != nil {
                wslogger.Warnln(reserr)
                jsonerr := &rpc.RpcErrorObject{-32603, reserr.Error()}
                JSON.Send(conn, &rpc.RpcErrorResponse{JsonRpc: jsonrpcver, ID: reqParsed.ID, Error: jsonerr})
                continue
            }

            wslogger.Debugf("Generated response: %T %s", response, response)
            JSON.Send(conn, &rpc.RpcSuccessResponse{JsonRpc: jsonrpcver, ID: reqParsed.ID, Result: response})
        }
    }
    return websocket.Handler(fn)
}