Yes, smoking is banned in all enclosed public areas (airports, libraries etc). Next year it will be brought in for restaurants, hotels and bars.
Mind you, we were offered a cigarette whilst in one of the jewellery shops last week and we asked if it was OK to smoke inside - yes the owner said, I have both doors open, it's fine!!
You can only smoke before you enter
Dalaman airport - there is nowhere to go to smoke once you've entered the building.
Mazz