plugin: add custommsg hook

The custommsg plugin hook is the receiving counterpart to the dev-sendcustommsg RPC method and allows plugins to handle messages that are not handled internally.

glightning/plugin.go

@@ -31,10 +31,54 @@ const (
 	_OpenChannel    Hook         = "openchannel"
 	_HtlcAccepted   Hook         = "htlc_accepted"
 	_RpcCommand     Hook         = "rpc_command"
+	_CustomMsg      Hook         = "custommsg"
 )
 
 var lightningMethodRegistry map[string]*jrpc2.Method
 
+// The custommsg plugin hook is the receiving counterpart to the dev-sendcustommsg RPC method
+//and allows plugins to handle messages that are not handled internally.
+type CustomMsgReceivedEvent struct {
+	PeerId  string `json:"peer_id"`
+	Payload string `json:"payload"`
+	hook    func(*CustomMsgReceivedEvent) (*CustomMsgReceivedResponse, error)
+}
+
+type _CustomMsgReceivedResult string
+
+const _CustomMsgReceivedContinue _CustomMsgReceivedResult = "continue"
+const _CustomMsgReceivedFail _CustomMsgReceivedResult = "fail"
+
+type CustomMsgReceivedResponse struct {
+	Result _CustomMsgReceivedResult `json:"result"`
+}
+
+func (pc *CustomMsgReceivedEvent) New() interface{} {
+	return &CustomMsgReceivedEvent{
+		hook: pc.hook,
+	}
+}
+
+func (pc *CustomMsgReceivedEvent) Name() string {
+	return string(_CustomMsg)
+}
+
+func (pc *CustomMsgReceivedEvent) Call() (jrpc2.Result, error) {
+	return pc.hook(pc)
+}
+
+func (pc *CustomMsgReceivedEvent) Continue() *CustomMsgReceivedResponse {
+	return &CustomMsgReceivedResponse{
+		Result: _CustomMsgReceivedContinue,
+	}
+}
+
+func (pc *CustomMsgReceivedEvent) Fail() *CustomMsgReceivedResponse {
+	return &CustomMsgReceivedResponse{
+		Result: _CustomMsgReceivedFail,
+	}
+}
+
 // This hook is called whenever a peer has connected and successfully completed
 //   the cryptographic handshake. The parameters have the following structure if
 //   there is a channel with the peer:
@@ -1139,12 +1183,13 @@ func (p *Plugin) Log(message string, level LogLevel) {
 // Map for registering hooks. Not the *most* elegant but
 //   it'll do for now.
 type Hooks struct {
-	PeerConnected  func(*PeerConnectedEvent) (*PeerConnectedResponse, error)
-	DbWrite        func(*DbWriteEvent) (*DbWriteResponse, error)
-	InvoicePayment func(*InvoicePaymentEvent) (*InvoicePaymentResponse, error)
-	OpenChannel    func(*OpenChannelEvent) (*OpenChannelResponse, error)
-	HtlcAccepted   func(*HtlcAcceptedEvent) (*HtlcAcceptedResponse, error)
-	RpcCommand     func(*RpcCommandEvent) (*RpcCommandResponse, error)
+	PeerConnected     func(*PeerConnectedEvent) (*PeerConnectedResponse, error)
+	DbWrite           func(*DbWriteEvent) (*DbWriteResponse, error)
+	InvoicePayment    func(*InvoicePaymentEvent) (*InvoicePaymentResponse, error)
+	OpenChannel       func(*OpenChannelEvent) (*OpenChannelResponse, error)
+	HtlcAccepted      func(*HtlcAcceptedEvent) (*HtlcAcceptedResponse, error)
+	RpcCommand        func(*RpcCommandEvent) (*RpcCommandResponse, error)
+	CustomMsgReceived func(*CustomMsgReceivedEvent) (*CustomMsgReceivedResponse, error)
 }
 
 func (p *Plugin) RegisterHooks(hooks *Hooks) error {
@@ -1202,6 +1247,15 @@ func (p *Plugin) RegisterHooks(hooks *Hooks) error {
 		}
 		p.hooks = append(p.hooks, _RpcCommand)
 	}
+	if hooks.CustomMsgReceived != nil {
+		err := p.server.Register(&CustomMsgReceivedEvent{
+			hook: hooks.CustomMsgReceived,
+		})
+		if err != nil {
+			return err
+		}
+		p.hooks = append(p.hooks, _CustomMsg)
+	}
 	return nil
 }
 

glightning/plugin_test.go

@@ -503,6 +503,36 @@ func TestHook_InvoicePaymentFail(t *testing.T) {
 	runTest(t, plugin, msg+"\n\n", resp)
 }
 
+func TestHook_Message(t *testing.T) {
+	initFn := getInitFunc(t, func(t *testing.T, options map[string]glightning.Option, config *glightning.Config) {
+		t.Error("Should not have called init when calling get manifest")
+	})
+	plugin := glightning.NewPlugin(initFn)
+	plugin.RegisterHooks(&glightning.Hooks{
+		CustomMsgReceived: func(event *glightning.CustomMsgReceivedEvent) (*glightning.CustomMsgReceivedResponse, error) {
+			return event.Continue(), nil
+		},
+	})
+	msg := `{"jsonrpc":"2.0", "id":"aloha", "method":"custommsg"}`
+	resp := `{"jsonrpc":"2.0","result":{"result":"continue"},"id":"aloha"}`
+	runTest(t, plugin, msg+"\n\n", resp)
+}
+
+func TestHook_MessageFail(t *testing.T) {
+	initFn := getInitFunc(t, func(t *testing.T, options map[string]glightning.Option, config *glightning.Config) {
+		t.Error("Should not have called init when calling get manifest")
+	})
+	plugin := glightning.NewPlugin(initFn)
+	plugin.RegisterHooks(&glightning.Hooks{
+		CustomMsgReceived: func(event *glightning.CustomMsgReceivedEvent) (*glightning.CustomMsgReceivedResponse, error) {
+			return event.Fail(), nil
+		},
+	})
+	msg := `{"jsonrpc":"2.0", "id":"aloha", "method":"custommsg"}`
+	resp := `{"jsonrpc":"2.0","result":{"result":"fail"},"id":"aloha"}`
+	runTest(t, plugin, msg+"\n\n", resp)
+}
+
 func TestSubscription_SendPaySuccess(t *testing.T) {
 	var wg sync.WaitGroup
 	defer await(t, &wg)