On Wed, 2017-08-16 at 11:18 -0400, Willem de Bruijn wrote:
> > If I read the above correctly, you are arguining in favor of the
> > addittional flag version, right?
>
> I was. Though if we are going to thread the argument from the caller
> to __skb_try_recv_from_queue to avoid rereading sk->sk_peek_off,
> on second thought it might be simpler to do it through off:
[...]
> This, of course, requires restricting sk_peek_off to protect against overflow.
Ok, even if I'm not 100% sure overall this will be simpler when adding
also the overflow check.
> If I'm not mistaken, the test in udp_recvmsg currently incorrectly sets
> peeking to false when peeking at offset zero:
>
> peeking = off = sk_peek_offset(sk, flags);
I think you are right, does not look correct.
> > --- a/net/core/sock.c
> > +++ b/net/core/sock.c
> > @@ -2408,9 +2408,7 @@ EXPORT_SYMBOL(__sk_mem_reclaim);
> >
> > int sk_set_peek_off(struct sock *sk, int val)
> > {
> > - if (val < 0)
> > - return -EINVAL;
> > -
> > + /* a negative value will disable peeking with offset */
> > sk->sk_peek_off = val;
> > return 0;
> > }
>
> Separate patch to net-next?
Agreed.
Paolo
