fix conn.Close() in function handleConnection (#180)

Co-authored-by: husyhu <husyhu@qq.com>

broker/broker.go

@@ -2,6 +2,7 @@ package broker
 
 import (
 	"crypto/tls"
+	"errors"
 	"fmt"
 	"net"
 	"net/http"
@@ -203,7 +204,10 @@ func (b *Broker) StartWebsocketListening() {
 func (b *Broker) wsHandler(ws *websocket.Conn) {
 	// io.Copy(ws, ws)
 	ws.PayloadType = websocket.BinaryFrame
-	b.handleConnection(CLIENT, ws)
+	err:=b.handleConnection(CLIENT, ws)
+	if err!=nil{
+		ws.Close()
+	}
 }
 
 func (b *Broker) StartClientListening(Tls bool) {
@@ -254,7 +258,12 @@ func (b *Broker) StartClientListening(Tls bool) {
 		}
 
 		tmpDelay = ACCEPT_MIN_SLEEP
-		go b.handleConnection(CLIENT, conn)
+		go func(){
+			err :=b.handleConnection(CLIENT, conn)
+			if err!=nil{
+				conn.Close()
+			}
+		}()
 	}
 }
 
@@ -291,7 +300,12 @@ func (b *Broker) StartClusterListening() {
 		}
 		tmpDelay = ACCEPT_MIN_SLEEP
 
-		go b.handleConnection(ROUTER, conn)
+		go func(){
+			err :=b.handleConnection(ROUTER, conn)
+			if err!=nil{
+				conn.Close()
+			}
+		}()
 	}
 }
 
@@ -307,22 +321,18 @@ func (b *Broker) DisConnClientByClientId(clientId string) {
 	conn.Close()
 }
 
-func (b *Broker) handleConnection(typ int, conn net.Conn) {
+func (b *Broker) handleConnection(typ int, conn net.Conn) error{
 	//process connect packet
 	packet, err := packets.ReadPacket(conn)
 	if err != nil {
-		log.Error("read connect packet error", zap.Error(err))
-		conn.Close()
-		return
+		return errors.New(fmt.Sprintln("read connect packet error:%v",err))
 	}
 	if packet == nil {
-		log.Error("received nil packet")
-		return
+		return errors.New("received nil packet")
 	}
 	msg, ok := packet.(*packets.ConnectPacket)
 	if !ok {
-		log.Error("received msg that was not Connect")
-		return
+		return errors.New("received msg that was not Connect")
 	}
 
 	log.Info("read connect from ", getAdditionalLogFields(msg.ClientIdentifier, conn)...)
@@ -332,29 +342,22 @@ func (b *Broker) handleConnection(typ int, conn net.Conn) {
 	connack.ReturnCode = msg.Validate()
 
 	if connack.ReturnCode != packets.Accepted {
-		func() {
-			defer conn.Close()
-			if err := connack.Write(conn); err != nil {
-				log.Error("send connack error", getAdditionalLogFields(msg.ClientIdentifier, conn, zap.Error(err))...)
-			}
-		}()
-		return
+		if err := connack.Write(conn); err != nil {
+			return errors.New(fmt.Sprintln("send connack error:%v,clientID:%v,conn:%v",err,msg.ClientIdentifier,conn))
+		}
+		return errors.New(fmt.Sprintln("connect packet validate failed with connack.ReturnCode%v",connack.ReturnCode))
 	}
 
 	if typ == CLIENT && !b.CheckConnectAuth(msg.ClientIdentifier, msg.Username, string(msg.Password)) {
 		connack.ReturnCode = packets.ErrRefusedNotAuthorised
-		func() {
-			defer conn.Close()
-			if err := connack.Write(conn); err != nil {
-				log.Error("send connack error", getAdditionalLogFields(msg.ClientIdentifier, conn, zap.Error(err))...)
-			}
-		}()
-		return
+		if err := connack.Write(conn); err != nil {
+			return errors.New(fmt.Sprintln("send connack error:%v,clientID:%v,conn:%v",err,msg.ClientIdentifier,conn))
+		}
+		return errors.New(fmt.Sprintln("connect packet CheckConnectAuth failed with connack.ReturnCode%v",connack.ReturnCode))
 	}
 
 	if err := connack.Write(conn); err != nil {
-		log.Error("send connack error", getAdditionalLogFields(msg.ClientIdentifier, conn, zap.Error(err))...)
-		return
+		return errors.New(fmt.Sprintln("send connack error:%v,clientID:%v,conn:%v",err,msg.ClientIdentifier,conn))
 	}
 
 	willmsg := packets.NewControlPacket(packets.Publish).(*packets.PublishPacket)
@@ -385,8 +388,7 @@ func (b *Broker) handleConnection(typ int, conn net.Conn) {
 	c.init()
 
 	if err := b.getSession(c, msg, connack); err != nil {
-		log.Error("get session error", getAdditionalLogFields(c.info.clientID, conn, zap.Error(err))...)
-		return
+		return errors.New(fmt.Sprintln("get session error:%v,clientID:%v,conn:%v",err,msg.ClientIdentifier,conn))
 	}
 
 	cid := c.info.clientID
@@ -426,6 +428,7 @@ func (b *Broker) handleConnection(typ int, conn net.Conn) {
 	}
 
 	c.readLoop()
+	return nil
 }
 
 func (b *Broker) ConnectToDiscovery() {