I have a canadian passport. Do I need a visa for transit via Shanghai and Kunming?

I am flying from Toronto to Shanghai (7pm), and then on to Kunming at 9pm. The flight from Kunming to Colombo, Sri Lanka is at 4:10pm, the next day. So, I am transiting through two airports in less than 24 hours.
1. Do I require visa?
2. Is two hours sufficient to exit the international airport and check in for the local flight at Shanghai?
2. Can I go outside the airport in Kunming for some sightseeing?

My return flight is via Shanghai, only one stopover.
Thank you for answering this question.
Vijay