Re: [PATCH bpf-next 4/8] tls: convert to generic sk_msg interface

On 10/12/2018 10:16 PM, Dave Watson wrote:

On 10/11/18 02:45 AM, Daniel Borkmann wrote:

quoted

Convert kTLS over to make use of sk_msg interface for plaintext and
encrypted scattergather data, so it reuses all the sk_msg helpers
and data structure which later on in a second step enables to glue
this to BPF.

Looks very clean, thanks!

Thanks, it indeed allows for getting rid of quite a bit of open coded
code by converting to sk_msg API. As it was mentioned in the other mail,
we'd also be able to reuse this framework in future for other potential
additions or ULPs aside from that; consolidating sockmap and tls to work
on the same data structure also helped a lot in testing.

quoted

-static int zerocopy_from_iter(struct sock *sk, struct iov_iter *from,
-			      int length, int *pages_used,
-			      unsigned int *size_used,
-			      struct scatterlist *to, int to_max_pages,
-			      bool charge)
-{

...

quoted

-			err = zerocopy_from_iter(sk, out_iov, data_len, &pages,
-						 chunk, &sgout[1],
-						 (n_sgout - 1), false);
+			err = tls_setup_from_iter(sk, out_iov, data_len,
+						  &pages, chunk, &sgout[1],
+						  (n_sgout - 1));

Any reason not to add the 'bool charge' to sk_msg_zerocopy_from_iter?
Then tls_setup_from_iter is not necessary.

I left this bit aside for now by leaving the tls_setup_from_iter() as is,
basically as current zerocopy_from_iter() in current tls code minus the
charge since not used here. Given this is only triggered in RX path (which
is not sk_msg based right now) I didn't want to wrap it into a fake/temp
sk_msg object just for calling into sk_msg_zerocopy_from_iter(), felt a bit
unclean and given the complexity we already have probably more appropriate
to pursue in a second step.

Thanks,
Daniel