Rework connection handling

go-pool/stratum/stratum.go

@@ -4,7 +4,6 @@ import (
 	"bufio"
 	"crypto/rand"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io"
 	"log"
@@ -144,9 +143,13 @@ func (s *StratumServer) Listen() {
 func (e *Endpoint) Listen(s *StratumServer) {
 	bindAddr := fmt.Sprintf("%s:%d", e.config.Host, e.config.Port)
 	addr, err := net.ResolveTCPAddr("tcp", bindAddr)
-	checkError(err)
+	if err != nil {
+		log.Fatalf("Error: %v", err)
+	}
 	server, err := net.ListenTCP("tcp", addr)
-	checkError(err)
+	if err != nil {
+		log.Fatalf("Error: %v", err)
+	}
 	defer server.Close()
 
 	log.Printf("Stratum listening on %s", bindAddr)
@@ -165,17 +168,13 @@ func (e *Endpoint) Listen(s *StratumServer) {
 
 		accept <- n
 		go func() {
-			err = s.handleClient(cs, e)
-			if err != nil {
-				s.removeSession(cs)
-				conn.Close()
-			}
+			s.handleClient(cs, e)
 			<-accept
 		}()
 	}
 }
 
-func (s *StratumServer) handleClient(cs *Session, e *Endpoint) error {
+func (s *StratumServer) handleClient(cs *Session, e *Endpoint) {
 	_, targetHex := util.GetTargetHex(e.config.Difficulty)
 	cs.targetHex = targetHex
 
@@ -185,15 +184,14 @@ func (s *StratumServer) handleClient(cs *Session, e *Endpoint) error {
 	for {
 		data, isPrefix, err := connbuff.ReadLine()
 		if isPrefix {
-			log.Printf("Socket flood detected")
-			return errors.New("Socket flood")
+			log.Println("Socket flood detected from", cs.ip)
+			break
 		} else if err == io.EOF {
 			log.Println("Client disconnected", cs.ip)
-			s.removeSession(cs)
 			break
 		} else if err != nil {
-			log.Printf("Error reading: %v", err)
-			return err
+			log.Println("Error reading:", err)
+			break
 		}
 
 		// NOTICE: cpuminer-multi sends junk newlines, so we demand at least 1 byte for decode
@@ -202,77 +200,73 @@ func (s *StratumServer) handleClient(cs *Session, e *Endpoint) error {
 			var req JSONRpcReq
 			err = json.Unmarshal(data, &req)
 			if err != nil {
-				log.Printf("Malformed request: %v", err)
-				return err
+				log.Printf("Malformed request from: %v", cs.ip, err)
+				break
 			}
 			s.setDeadline(cs.conn)
-			cs.handleMessage(s, e, &req)
+			err = cs.handleMessage(s, e, &req)
+			if err != nil {
+				break
+			}
 		}
 	}
-	return nil
+	s.removeSession(cs)
+	cs.conn.Close()
 }
 
-func (cs *Session) handleMessage(s *StratumServer, e *Endpoint, req *JSONRpcReq) {
+func (cs *Session) handleMessage(s *StratumServer, e *Endpoint, req *JSONRpcReq) error {
 	if req.Id == nil {
-		log.Println("Missing RPC id")
-		cs.conn.Close()
-		return
+		err := fmt.Errorf("Server disconnect request")
+		log.Println(err)
+		return err
 	} else if req.Params == nil {
-		log.Println("Missing RPC params")
-		cs.conn.Close()
-		return
+		err := fmt.Errorf("Server RPC request params")
+		log.Println(err)
+		return err
 	}
 
-	var err error
-
 	// Handle RPC methods
 	switch req.Method {
+
 	case "login":
 		var params LoginParams
-		err = json.Unmarshal(*req.Params, &params)
+		err := json.Unmarshal(*req.Params, &params)
 		if err != nil {
 			log.Println("Unable to parse params")
-			break
+			return err
 		}
 		reply, errReply := s.handleLoginRPC(cs, e, &params)
 		if errReply != nil {
-			err = cs.sendError(req.Id, errReply)
-			break
+			return cs.sendError(req.Id, errReply, true)
 		}
-		err = cs.sendResult(req.Id, &reply)
+		return cs.sendResult(req.Id, &reply)
 	case "getjob":
 		var params GetJobParams
-		err = json.Unmarshal(*req.Params, &params)
+		err := json.Unmarshal(*req.Params, &params)
 		if err != nil {
 			log.Println("Unable to parse params")
-			break
+			return err
 		}
 		reply, errReply := s.handleGetJobRPC(cs, e, &params)
 		if errReply != nil {
-			err = cs.sendError(req.Id, errReply)
-			break
+			return cs.sendError(req.Id, errReply, true)
 		}
-		err = cs.sendResult(req.Id, &reply)
+		return cs.sendResult(req.Id, &reply)
 	case "submit":
 		var params SubmitParams
 		err := json.Unmarshal(*req.Params, &params)
 		if err != nil {
 			log.Println("Unable to parse params")
-			break
+			return err
 		}
 		reply, errReply := s.handleSubmitRPC(cs, e, &params)
 		if errReply != nil {
-			err = cs.sendError(req.Id, errReply)
-			break
+			return cs.sendError(req.Id, errReply, true)
 		}
-		err = cs.sendResult(req.Id, &reply)
+		return cs.sendResult(req.Id, &reply)
 	default:
 		errReply := s.handleUnknownRPC(cs, req)
-		err = cs.sendError(req.Id, errReply)
-	}
-
-	if err != nil {
-		cs.conn.Close()
+		return cs.sendError(req.Id, errReply, true)
 	}
 }
 
@@ -290,15 +284,18 @@ func (cs *Session) pushMessage(method string, params interface{}) error {
 	return cs.enc.Encode(&message)
 }
 
-func (cs *Session) sendError(id *json.RawMessage, reply *ErrorReply) error {
+func (cs *Session) sendError(id *json.RawMessage, reply *ErrorReply, drop bool) error {
 	cs.Lock()
 	defer cs.Unlock()
 	message := JSONRpcResp{Id: id, Version: "2.0", Error: reply}
 	err := cs.enc.Encode(&message)
-	if reply.Close {
-		return errors.New("Force close")
+	if err != nil {
+		return err
+	}
+	if drop {
+		return fmt.Errorf("Server disconnect request")
 	}
-	return err
+	return nil
 }
 
 func (s *StratumServer) setDeadline(conn *net.TCPConn) {
@@ -364,9 +361,3 @@ func (s *StratumServer) rpc() *rpc.RPCClient {
 	i := atomic.LoadInt32(&s.upstream)
 	return s.upstreams[i]
 }
-
-func checkError(err error) {
-	if err != nil {
-		log.Fatalf("Error: %v", err)
-	}
-}