Hello! I am travelling to China on the 15th June 2017. I am in Shanghai for 4 days

before I fly to Australia on the 19th June 2017. Before we enter Australia, we are stopping off in Guanghouz (but are not leaving the airport). Do I need a single entry visa, double entry or multiple entry one?
I am also stopping off in Guanghouz on my return flight from Australia 2 weeks later (3rd July 2017).
Thank you!!!