rpc, xeth: fix #881, gracefully handle offline whisper

rpc/api.go

@@ -439,10 +439,18 @@ func (api *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) err
 		*reply = newHexData(res)
 
 	case "shh_version":
+		// Short circuit if whisper is not running
+		if api.xeth().Whisper() == nil {
+			return NewNotAvailableError(req.Method, "whisper offline")
+		}
 		// Retrieves the currently running whisper protocol version
 		*reply = api.xeth().WhisperVersion()
 
 	case "shh_post":
+		// Short circuit if whisper is not running
+		if api.xeth().Whisper() == nil {
+			return NewNotAvailableError(req.Method, "whisper offline")
+		}
 		// Injects a new message into the whisper network
 		args := new(WhisperMessageArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
@@ -455,10 +463,18 @@ func (api *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) err
 		*reply = true
 
 	case "shh_newIdentity":
+		// Short circuit if whisper is not running
+		if api.xeth().Whisper() == nil {
+			return NewNotAvailableError(req.Method, "whisper offline")
+		}
 		// Creates a new whisper identity to use for sending/receiving messages
 		*reply = api.xeth().Whisper().NewIdentity()
 
 	case "shh_hasIdentity":
+		// Short circuit if whisper is not running
+		if api.xeth().Whisper() == nil {
+			return NewNotAvailableError(req.Method, "whisper offline")
+		}
 		// Checks if an identity if owned or not
 		args := new(WhisperIdentityArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
@@ -467,6 +483,10 @@ func (api *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) err
 		*reply = api.xeth().Whisper().HasIdentity(args.Identity)
 
 	case "shh_newFilter":
+		// Short circuit if whisper is not running
+		if api.xeth().Whisper() == nil {
+			return NewNotAvailableError(req.Method, "whisper offline")
+		}
 		// Create a new filter to watch and match messages with
 		args := new(WhisperFilterArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
@@ -476,6 +496,10 @@ func (api *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) err
 		*reply = newHexNum(big.NewInt(int64(id)).Bytes())
 
 	case "shh_uninstallFilter":
+		// Short circuit if whisper is not running
+		if api.xeth().Whisper() == nil {
+			return NewNotAvailableError(req.Method, "whisper offline")
+		}
 		// Remove an existing filter watching messages
 		args := new(FilterIdArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
@@ -484,6 +508,10 @@ func (api *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) err
 		*reply = api.xeth().UninstallWhisperFilter(args.Id)
 
 	case "shh_getFilterChanges":
+		// Short circuit if whisper is not running
+		if api.xeth().Whisper() == nil {
+			return NewNotAvailableError(req.Method, "whisper offline")
+		}
 		// Retrieve all the new messages arrived since the last request
 		args := new(FilterIdArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
@@ -492,12 +520,17 @@ func (api *EthereumApi) GetRequestReply(req *RpcRequest, reply *interface{}) err
 		*reply = api.xeth().WhisperMessagesChanged(args.Id)
 
 	case "shh_getMessages":
+		// Short circuit if whisper is not running
+		if api.xeth().Whisper() == nil {
+			return NewNotAvailableError(req.Method, "whisper offline")
+		}
 		// Retrieve all the cached messages matching a specific, existing filter
 		args := new(FilterIdArgs)
 		if err := json.Unmarshal(req.Params, &args); err != nil {
 			return err
 		}
 		*reply = api.xeth().WhisperMessages(args.Id)
+
 	case "eth_hashrate":
 		*reply = newHexNum(api.xeth().HashRate())