I camped in a similar tent as a young scout. We just called them "Army Tents" or "canvas tents", but I doubt that is the proper name you are looking for.
The tents we had were a little different. They were as you described, but there was no 'frame' to them. There were simply 2 six-foot poles at each end (one at the back wall, one at the opening) that were secured to the tent by grommets. Then, guy lines pulled the tent walls out on the sides, and supported the front and back.
Hope this helped,
Don
