Dissect request/response of protobuf service method without gRPC

edit

After digging into the protobuf dissector, it supports parsing the pb_msg_type of syntax application/grpc,/service/method,direction, and it works.

local protobuf_dissector = Dissector.get("protobuf")
pinfo.private["pb_msg_type"] = "application/grpc,/" .. service_name .. "/" .. method_name .. ",request"
protobuf_dissector:call(tvb_body, pinfo, tree)

Just note that there must be a space between the method name and paren.

service Greeter {
    rpc SayHello (HelloRequest) returns (HelloResponse);
}