My ipod is broken, if I send it in, how long will it take to get it fixed?

The USB port, or whatever it is called on my ipod touch is broken. I know it is not the cable, because I have tried a few different ones, and I used my transmitter, and that won't work. Plus i used my car charger. Something is loose inside of the ipod. It will not charge. It won't plug in. I even tried taping the usb down, and now my ipod is all sticky. but anyway, It is still under warranty so i can send it in. But how long does it usually take to get it back or get a new one back? I really need it. I am going on a trip and I can't go on an 8 hour drive without it. So how long does it generally take?