EOF and zero-length packets?

	Hello,

When dealing with SOCK_STREAM sockets, a zero read means the other side has 
shut down the connection, and there will be no more incoming data.

When dealing with SOCK_DGRAM/SOCK_RAW sockets, a zero read means we got an 
empty packet, and we should keep on reading.

What about SOCK_DCCP? It seems both scenarios yield zero, which is, hmm, 
problematic from userland. Is checking for POLLHUP in revents the recommended 
disambiguation? that seems a bit backward to me :(

-- 
Rémi Denis-Courmont
http://www.remlab.net/