How do I protect against a client that stops sending data, either between messages or within a message?

With Gorilla, I can use a combination of read deadline and ping/pong to ensure that a client is sending messages. Once reading a message, I can set the read deadline to ensure that the client sends the message in a timely fashion.

With this package, I can specify one timeout using the context argument to Conn.Reader. How do I adjust that value after a successful call to Conn.Ping? How do I adjust that value down after receiving the first byte of message data?