The DynamicPreprocessorData structure defines the interface the preprocessor uses to interact with snort itself. This includes functions to register the preprocessor's configuration parsing, restart, exit, and processing functions. It includes function to log messages, errors, fatal errors, and debugging info. It also includes information for setting alerts, handling Inline drops, access to the StreamAPI, and it provides access to the normalized http and alternate data buffers. This data structure should be initialized when the preprocessor shared library is loaded. It is defined in sf_dynamic_preprocessor.h. Check the header file for the current definition.