Advice on using KTLS with `splice`?

[jeromegn]

(Hey there! 👋)

We're looking into using splice for some transfers of IO and I'm wondering if it's possible with this crate.

My concern is that it might buffer some data that's not part of the TLS handshake (as mentioned in the docs for the CorkStream). So if I do want to use splice, should I do the first read / write using userspace copy? If I knew that there was buffered data, I could skip this step.

[cxw620]

Feel free to use it, you shall just handle the drained data return by tls_stream.into_raw() after you have ktls set up (I just reuse it as the buffer parsing HTTP/1.1 request with httparse, and after you write http/1.1 status line and header lines, just do splice. You may need tokio-splice2 that I modify from tokio-splice for single direction copy).

[imlk0]

@cxw620 Hi, thanks for your advice and great work on tokio-splice2. But AFAIK, tls_stream.into_raw() will drop the internal state of KtlsStream (i.e., write_closed: bool and read_closed: bool). The caller would then need to handle any "input/output error" caused by control messages, and also handle the shutdown, which would duplicate the logic at here and here.

Therefore, it would be better if ktls could expose some interfaces for interoperability with splice()? Do you have any suggestions on this?

[cxw620]

Therefore, it would be better if ktls could expose some interfaces for interoperability with splice()? Do you have any suggestions on this?

PR #62 (or the continuation: https://github.com/hanyu-dev/ktls) shows my implementation.