Re: [PATCH net-next v1 0/2] netdevsim: add TLS device offload emulation and test

From: Jiayuan Chen

Date: Thu Sep 03 2026 - 22:14:10 EST



on 9/4/26 6:59 AM, Jakub Kicinski wrote:
On Tue, 1 Sep 2026 23:48:55 +0800 Jiayuan Chen wrote:
It helped me find
commit b17cf742eaad ("tls: device: fix out-of-bounds write in tls_append_frag()").

So I think it is worth sending a formal patchset.

The kTLS device offload path in net/tls/tls_device.c has no test
coverage upstream -- selftests/net/tls.c is software only, and the
offload code needs a driver that implements it.

So teach netdevsim to fake it. Patch 1 implements tlsdev_ops and
advertises the TLS features, patch 2 adds a selftest.

No crypto is done: TX puts the plaintext record on the wire, RX just
sets skb->decrypted. That only works netdevsim to netdevsim, but it
covers record assembly and the offload lifecycle. Real ciphertext, and
more on top of it, can come later.
Please don't post selftests to net-next which depend on a fix going
to another tree. If we merge this now we will have a failing test
until the fix also lands.

If we add TLS support to netdevsim it must be paired with a test
which can also run against real HW. There was a selftest posted
recently by the person working on TLS 1.3 offload, we can use that
as the target (feel free to add that to your series, just keep
the original author).

We can add special netdevsim-only cases but the main focus should
be writing tests that can be executed against real devices.


I think I just wait until that series is merged and then take a next setp.