lnrpc: update custom message API to explain ability to override

lnrpc/lightning.pb.go

@@ -1517,6 +1517,9 @@ type SendCustomMessageRequest struct {
 	// Peer to send the message to
 	Peer []byte `protobuf:"bytes,1,opt,name=peer,proto3" json:"peer,omitempty"`
 	// Message type. This value needs to be in the custom range (>= 32768).
+	// To send a type < custom range, lnd needs to be compiled with the `dev`
+	// build tag, and the message type to override should be specified in lnd's
+	// experimental protocol configuration.
 	Type uint32 `protobuf:"varint,2,opt,name=type,proto3" json:"type,omitempty"`
 	// Raw message data.
 	Data []byte `protobuf:"bytes,3,opt,name=data,proto3" json:"data,omitempty"`

lnrpc/lightning.proto

@@ -567,6 +567,10 @@ service Lightning {
     /* lncli: `subscribecustom`
     SubscribeCustomMessages subscribes to a stream of incoming custom peer
     messages.
+
+    To include messages with type outside of the custom range (>= 32768) lnd
+    needs to be compiled with  the `dev` build tag, and the message type to
+    override should be specified in lnd's experimental protocol configuration.
     */
     rpc SubscribeCustomMessages (SubscribeCustomMessagesRequest)
         returns (stream CustomMessage);
@@ -612,6 +616,9 @@ message SendCustomMessageRequest {
     bytes peer = 1;
 
     // Message type. This value needs to be in the custom range (>= 32768).
+    // To send a type < custom range, lnd needs to be compiled with the `dev`
+    // build tag, and the message type to override should be specified in lnd's
+    // experimental protocol configuration.
     uint32 type = 2;
 
     // Raw message data.

lnrpc/lightning.swagger.json

@@ -918,6 +918,7 @@
     "/v1/custommessage/subscribe": {
       "get": {
         "summary": "lncli: `subscribecustom`\nSubscribeCustomMessages subscribes to a stream of incoming custom peer\nmessages.",
+        "description": "To include messages with type outside of the custom range (\u003e= 32768) lnd\nneeds to be compiled with  the `dev` build tag, and the message type to\noverride should be specified in lnd's experimental protocol configuration.",
         "operationId": "Lightning_SubscribeCustomMessages",
         "responses": {
           "200": {
@@ -6616,7 +6617,7 @@
         "type": {
           "type": "integer",
           "format": "int64",
-          "description": "Message type. This value needs to be in the custom range (\u003e= 32768)."
+          "description": "Message type. This value needs to be in the custom range (\u003e= 32768).\nTo send a type \u003c custom range, lnd needs to be compiled with the `dev`\nbuild tag, and the message type to override should be specified in lnd's\nexperimental protocol configuration."
         },
         "data": {
           "type": "string",

lnrpc/lightning_grpc.pb.go

@@ -392,6 +392,10 @@ type LightningClient interface {
 	// lncli: `subscribecustom`
 	// SubscribeCustomMessages subscribes to a stream of incoming custom peer
 	// messages.
+	//
+	// To include messages with type outside of the custom range (>= 32768) lnd
+	// needs to be compiled with  the `dev` build tag, and the message type to
+	// override should be specified in lnd's experimental protocol configuration.
 	SubscribeCustomMessages(ctx context.Context, in *SubscribeCustomMessagesRequest, opts ...grpc.CallOption) (Lightning_SubscribeCustomMessagesClient, error)
 	// lncli: `listaliases`
 	// ListAliases returns the set of all aliases that have ever existed with
@@ -1687,6 +1691,10 @@ type LightningServer interface {
 	// lncli: `subscribecustom`
 	// SubscribeCustomMessages subscribes to a stream of incoming custom peer
 	// messages.
+	//
+	// To include messages with type outside of the custom range (>= 32768) lnd
+	// needs to be compiled with  the `dev` build tag, and the message type to
+	// override should be specified in lnd's experimental protocol configuration.
 	SubscribeCustomMessages(*SubscribeCustomMessagesRequest, Lightning_SubscribeCustomMessagesServer) error
 	// lncli: `listaliases`
 	// ListAliases returns the set of all aliases that have ever existed with