Convert ProtocolError to value-type, so that it can be used withh errors.As + fix SubmitBlock ProtocolError condition (#1555)

* Fix condition from || to &&

* Convert ProtocolError to value-type, so that it can be used wihth errors.As

* Simplify condition further

app/protocol/flowcontext/errors.go

@@ -18,7 +18,7 @@ import (
 func (*FlowContext) HandleError(err error, flowName string, isStopping *uint32, errChan chan<- error) {
 	isErrRouteClosed := errors.Is(err, router.ErrRouteClosed)
 	if !isErrRouteClosed {
-		if protocolErr := &(protocolerrors.ProtocolError{}); !errors.As(err, &protocolErr) {
+		if protocolErr := (protocolerrors.ProtocolError{}); !errors.As(err, &protocolErr) {
 			panic(err)
 		}
 

app/protocol/flows/handshake/handshake.go

@@ -107,7 +107,7 @@ func handleError(err error, flowName string, isStopping *uint32, errChan chan er
 		return
 	}
 
-	if protocolErr := &(protocolerrors.ProtocolError{}); errors.As(err, &protocolErr) {
+	if protocolErr := (protocolerrors.ProtocolError{}); errors.As(err, &protocolErr) {
 		log.Errorf("Handshake protocol error from %s: %s", flowName, err)
 		if atomic.AddUint32(isStopping, 1) == 1 {
 			errChan <- err

app/protocol/flows/testing/common_test.go

@@ -1,14 +1,15 @@
 package testing
 
 import (
-	"github.com/kaspanet/kaspad/app/protocol/protocolerrors"
-	"github.com/pkg/errors"
 	"strings"
 	"testing"
+
+	"github.com/kaspanet/kaspad/app/protocol/protocolerrors"
+	"github.com/pkg/errors"
 )
 
 func checkFlowError(t *testing.T, err error, isProtocolError bool, shouldBan bool, contains string) {
-	pErr := &protocolerrors.ProtocolError{}
+	pErr := protocolerrors.ProtocolError{}
 	if errors.As(err, &pErr) != isProtocolError {
 		t.Fatalf("Unexepcted error %+v", err)
 	}

app/protocol/protocol.go

@@ -1,9 +1,10 @@
 package protocol
 
 import (
+	"sync/atomic"
+
 	"github.com/kaspanet/kaspad/app/protocol/flows/rejects"
 	"github.com/kaspanet/kaspad/infrastructure/network/connmanager"
-	"sync/atomic"
 
 	"github.com/kaspanet/kaspad/app/appmessage"
 	"github.com/kaspanet/kaspad/app/protocol/flows/addressexchange"
@@ -75,7 +76,7 @@ func (m *Manager) routerInitializer(router *routerpkg.Router, netConnection *net
 }
 
 func (m *Manager) handleError(err error, netConnection *netadapter.NetConnection, outgoingRoute *routerpkg.Route) {
-	if protocolErr := &(protocolerrors.ProtocolError{}); errors.As(err, &protocolErr) {
+	if protocolErr := (protocolerrors.ProtocolError{}); errors.As(err, &protocolErr) {
 		if !m.context.Config().DisableBanning && protocolErr.ShouldBan {
 			log.Warnf("Banning %s (reason: %s)", netConnection, protocolErr.Cause)
 

app/protocol/protocolerrors/protocolerrors.go

@@ -12,19 +12,19 @@ type ProtocolError struct {
 	Cause     error
 }
 
-func (e *ProtocolError) Error() string {
+func (e ProtocolError) Error() string {
 	return e.Cause.Error()
 }
 
 // Unwrap returns the cause of ProtocolError, to be used with `errors.Unwrap()`
-func (e *ProtocolError) Unwrap() error {
+func (e ProtocolError) Unwrap() error {
 	return e.Cause
 }
 
 // Errorf formats according to a format specifier and returns the string
 // as a ProtocolError.
 func Errorf(shouldBan bool, format string, args ...interface{}) error {
-	return &ProtocolError{
+	return ProtocolError{
 		ShouldBan: shouldBan,
 		Cause:     errors.Errorf(format, args...),
 	}
@@ -33,7 +33,7 @@ func Errorf(shouldBan bool, format string, args ...interface{}) error {
 // New returns a ProtocolError with the supplied message.
 // New also records the stack trace at the point it was called.
 func New(shouldBan bool, message string) error {
-	return &ProtocolError{
+	return ProtocolError{
 		ShouldBan: shouldBan,
 		Cause:     errors.New(message),
 	}
@@ -41,7 +41,7 @@ func New(shouldBan bool, message string) error {
 
 // Wrap wraps the given error and returns it as a ProtocolError.
 func Wrap(shouldBan bool, err error, message string) error {
-	return &ProtocolError{
+	return ProtocolError{
 		ShouldBan: shouldBan,
 		Cause:     errors.Wrap(err, message),
 	}
@@ -49,7 +49,7 @@ func Wrap(shouldBan bool, err error, message string) error {
 
 // Wrapf wraps the given error with the given format and returns it as a ProtocolError.
 func Wrapf(shouldBan bool, err error, format string, args ...interface{}) error {
-	return &ProtocolError{
+	return ProtocolError{
 		ShouldBan: shouldBan,
 		Cause:     errors.Wrapf(err, format, args...),
 	}

app/rpc/rpchandlers/submit_block.go

@@ -26,7 +26,8 @@ func HandleSubmitBlock(context *rpccontext.Context, _ *router.Router, request ap
 
 	err := context.ProtocolManager.AddBlock(domainBlock)
 	if err != nil {
-		if !errors.As(err, &ruleerrors.RuleError{}) || !errors.As(err, &protocolerrors.ProtocolError{}) {
+		isProtocolOrRuleError := errors.As(err, &ruleerrors.RuleError{}) || errors.As(err, &protocolerrors.ProtocolError{})
+		if !isProtocolOrRuleError {
 			return nil, err
 		}