I have a blocking sento call issued by my application. The packets are UDP.

1. What will happen when the n/w driver's queue gets filled?
2. If linux silently starts discarding packets will my sendto hang forever?
3. What does sendto ensures I mean at what point does it returns. Does its reponsibility includes making sure that the packet is inserted in the queue of driver and keep on retrying till then or it just sends the packet to driver and returns not caring whether the driver drops the packets in case its queue is filled?

Thanks in advance