In an ideal world (fully legal recreational marijuana), my rules would be: edibles are fine, no smoking of anything in the house, and if you smoke outside and come in reeking, I might ask you to go home and take a shower.
Back to reality: Florida only recently legalized medicinal MJ, and I do work for the federal government and could basically kill my career if I ever tested positive. So until that changes, my policy is tobacco outside, MJ at home.
I frown on but don't prohibit e-Cigs at the table. I only have one player who does it, and as long as he's considerate about it (which he always is), I don't hassle him.