The Greeks and Romans both used plenty of hemp for ropes and shipbuilding. As to the drugs, they had them too and were probably imported. The medical texts of the day, such as the Greek Dioscorides' Materia Medica mention hemp. Their knowledge about the drugs was somewhat limited compared to the Arabs and Indians. Some of the Roman texts mention people eating cannabis desserts after dinner, but you had to be careful not to eat too much lest the vapors go to your head, indicating that they were consuming intoxicating edibles. Its hard to know how common cannabis drugs were, but they existed for the Greeks and Romans.