How should UDP handle partial packets?

[brson]

Our UDP reader silently truncates partial packets. Possibly we should raise a condition when this happens.

[MaikKlein]

From the LibUV book:

Since UDP sockets are not connected to a particular peer, the read callback receives an extra parameter about the >sender of the packet. The flags parameter may be UV_UDP_PARTIAL if the buffer provided by your allocator was not >large enough to hold the data. In this case the OS will discard the data that could not fit (That’s UDP for you!).

So it seems to behave correctly. The problem is the user will never now that there was a partial read.

[Gankra]

CC @aturon

[alexcrichton]

This was addressed in the I/O reform by having write return the number of bytes written.