* @param hook Next IOHook in the chain, can be NULL
* @param rq Receive queue to put incoming data into
* @return < 0 on error or close, 0 if no new data is ready (but the socket is still connected), > 0 if data was read from
* @param hook Next IOHook in the chain, can be NULL
* @param rq Receive queue to put incoming data into
* @return < 0 on error or close, 0 if no new data is ready (but the socket is still connected), > 0 if data was read from