On Tue, Apr 25, 2000 at 01:53:51AM +0200, David S. Miller wrote:
> Date: Tue, 25 Apr 2000 01:50:08 +0200
> From: Andi Kleen <ak@xxxxxx>
> > I know intuitively that once, for example, tcp_transmit_skb has
> > built the TCP header the control block can be clobbered by any
> > further usage. We should really document this, at least in a
> > comment above that function.
> I documented it in skbuff.h (``is owned by whoever has the skb queued'')
> BTW, the hippi private fields should be probably moved there too.
> This brings up an important issue. What if then, we'd like to shape
> packets over HIPPI? It sounds really stupid, I know, but the point
> is that once we start allowing software or hardware devices to use the
> CB for their private per-packet state, we can run into problems if one
> is a pseudo device in front of another.
> If shaper mucks with it's CB fields, and once it has sent the packet
> off to the real device it never references that skb header again, then
> at least in this case there is no problem. Is that what is happening
Not a problem. Shaper calls skb_clone before submitting the data.
This is like TV. I don't like TV.