Transit permit needed?

I'll be traveling to Tokyo, Japan from Calcutta, India. I have 2 stops. First one is at Kunming where the layover is of 2.5 hours and the second stop is at shanghai for 1.5 hours, both the stops on the same day.
On my return journey, i have stops at similar places on my return journey but i have to change my airport in shanghai from pudong to hongqiao. So, will i need a transit visa ? P.s- I'm Indian