On Mon, Aug 14, 2017 at 1:02 PM, Thiago Macieira <thiago.macie...@intel.com> wrote: > 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.
It can be argued either way. I would not change it in the scope of this bug. > >> 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? It is established behavior. It cannot be ruled out that an application somewhere depends on it.
