Canadian citizens (family of 4) overnighting in Shanghai en route to VietNam.

We will be in Shanghai less than 24 hrs. en route to Vietnam and Cambodia. All airline tickets are in place. Do we need to arrange any visa documentation prior to departure from Canada? Upon arrival in Shanghai, do we need any application forms/ photos/ fees? We will be staying in a hotel overnight in Shanghai, but total time there less than 24 hrs.
Wendy