Sadly the cheap airlines in Europe have now started charging for standard size carry-on bags, and they're charging quite a lot relative to ticket prices (for example, a ticket to Budapest for the weekend before Easter is 108zl return but if you want to take a carry on bag, that's another 90zl return).

So I need a small carry-on bag. The maximum size is 42 x 32 x 25 cm (17 x 13 x 10 inches). What are the best Oakley options?

Holy crap is that small (and expensive). The Small Icon Pack gets you to the dimensions and the Bathroom Sink gets you close. They might both work if they don't measure your full bag before you board.