Richard Levitte

I've added pointers to a `OSSL_ACKM` and a `OSSL_QRX` in `QUIC_CONNECTION`, and added `SSL_ctrl()` commands to set them, given a `QUIC_CONNECTION *` passed as an `SSL *`. This allows test...

> > I've added pointers to a `OSSL_ACKM` and a `OSSL_QRX` in `QUIC_CONNECTION`, and added `SSL_ctrl()` commands to set them, given a `QUIC_CONNECTION *` passed as an `SSL *`. This...

> > The other option I see is to make `QUIC_CONNECTION` "internal" (i.e. defined in a include/internal header) instead of so deeply private. But that's a lot more invasive, so...

> I expected to see some code handling the `C` spec here: frames containing only ACKs do not count towards bytes in flight for congestion control purposes. The depacketiser seems...

> > I expected to see some code handling the `C` spec here: frames containing only ACKs do not count towards bytes in flight for congestion control purposes. The depacketiser...

It seems that all review comments have been addressed

All CIs are happy now

This is the port of #18730 for higher OpenSSL versions

This is a very early draft with a bunch of missing pieces

This PR is ready for comments. What needs more detail? What did I forget? Mind you, I'm going on vacation June 23rd -- July 4th, so will not respond much...