Implementing UDP

[apamment]

Hi

I'm just starting to implement UDP on my OS, and I think I understand it correctly, I am just wondering what happens to the packets who are from addresses you don't recv_from. Does the tcp/ip stack just time them out and delete them after a little while? Or retain them in case you do a recv_from for that address later on? I imagine you wouldn't normally get random packets from internet addresses unless you were a server and expecting them or a client and someone was trying to do something sinister?

thanks..

[Nable]

Either there is a listening application for this pair "destination address, port" and packet is added to queue (and dropped if there's no space left) or it's dropped immediately (if there's no such queue).

[apamment]

Ok, thanks. I misunderstood recvfrom, I thought it only returned packets for a specific address, but it seems to return packets from any address with the address. So the application deals with packets from addresses it doesn't want.