In my brief look-round, most homosexuality was not banned (at least in ancient Mesopotamia), and in fact seemed to be sanctioned somewhat, as there were homosexual prostitutes as part of the temple entourage.

In Ancient Egypt, it seemed to have been looked down upon, as most of the cited references seem to view it as shameful.

This website provides a fairly comprehensive look at several areas of the world during the time period in question, and cites some research.

However, you should take these with a grain of salt, because, as the website quotes, "most of the research for the information referenced here comes through pro-homosexual writers, who sometimes interpret obscure or indefinite data as positively denoting homosexuality, while tending to render negative comments on homosexuality as being due to homophobia".

Therefore, you should check all cited sources (something I recommend anyway). I looked at the Mesopotamian sources, and they seemed accurate to me, at least from a brief look. Wenham's 1991 article and the citations from the Reallexicon der Assyriologie seem to be pretty sound.