On Monday, 14 August 2017 09:33:48 PDT Willem de Bruijn wrote: > > But here's a question: if the peek offset is equal to the length, should > > the reading return an empty datagram? This would indicate to the caller > > that there was a datagram there, which was skipped over. > > In the general case, no, it should read at the offset, which is the next > skb.
I beg to differ. In this particular case, we are talking about datagrams. If it were stream sockets, I would agree with you: just skip to the next. But in datagrams, the same way you do return zero-sized ones, I would return an empty one if you peeked at or past the end. > Since we only need to change no-offset semantics to fix this bug, > I would not change this behavior, which is also expected by some > applications by now. Do applications using SOCK_DGRAM rely on the behaviour of skipping over datagrams that are too short? > > That's how we deal with empty datagrams anyway. > > What is? With no-offset and a zero payload skb at the head, peek > or recv returns 0, right? Right. -- Thiago Macieira - thiago.macieira (AT) intel.com Software Architect - Intel Open Source Technology Center
