1 files changed, 24 insertions, 3 deletions
diff --git a/core/request_handler.go b/core/request_handler.go
index 4a62754..7c185cd 100644
--- a/core/request_handler.go
+++ b/core/request_handler.go
@@ -24,6 +24,10 @@ import (
 	"git.fd.io/govpp.git/api"
 )
 
+var (
+	ErrNotConnected = errors.New("not connected to VPP, ignoring the request")
+)
+
 // watchRequests watches for requests on the request API channel and forwards them as messages to VPP.
 func (c *Connection) watchRequests(ch *api.Channel, chMeta *channelMetadata) {
 	for {
@@ -48,7 +52,7 @@ func (c *Connection) watchRequests(ch *api.Channel, chMeta *channelMetadata) {
 func (c *Connection) processRequest(ch *api.Channel, chMeta *channelMetadata, req *api.VppRequest) error {
 	// check whether we are connected to VPP
 	if atomic.LoadUint32(&c.connected) == 0 {
-		err := errors.New("not connected to VPP, ignoring the request")
+		err := ErrNotConnected
 		log.Error(err)
 		sendReply(ch, &api.VppReply{Error: err})
 		return err
@@ -189,9 +193,11 @@ func (c *Connection) GetMessageID(msg api.Message) (uint16, error) {
 
 // messageNameToID returns message ID of a message identified by its name and CRC.
 func (c *Connection) messageNameToID(msgName string, msgCrc string) (uint16, error) {
+	msgKey := msgName + "_" + msgCrc
+
 	// try to get the ID from the map
 	c.msgIDsLock.RLock()
-	id, ok := c.msgIDs[msgName+msgCrc]
+	id, ok := c.msgIDs[msgKey]
 	c.msgIDsLock.RUnlock()
 	if ok {
 		return id, nil
@@ -209,8 +215,23 @@ func (c *Connection) messageNameToID(msgName string, msgCrc string) (uint16, err
 	}
 
 	c.msgIDsLock.Lock()
-	c.msgIDs[msgName+msgCrc] = id
+	c.msgIDs[msgKey] = id
 	c.msgIDsLock.Unlock()
 
 	return id, nil
 }
+
+// LookupByID looks up message name and crc by ID.
+func (c *Connection) LookupByID(ID uint16) (string, error) {
+	if c == nil {
+		return "", errors.New("nil connection passed in")
+	}
+
+	for key, id := range c.msgIDs {
+		if id == ID {
+			return key, nil
+		}
+	}
+
+	return "", fmt.Errorf("unknown message ID: %d", ID)
+}