Add missing ops up to Linux 6.15

[silvanshade]

This PR adds missing ops for io_uring up to Linux 6.15.

Related:

• Add more io_uring ZCRX definitions sunfishcode/linux-raw-sys#158
• Linux 6.15 io_uring bytecodealliance/rustix#1485
• Fix test_tcp_send_bundle #22 (included in this PR so the tests can run)

Opening as a Draft since there's still some remaining changes to make.

[silvanshade]

@sunfishcode I think this is ready for review. This has dependencies on the upstream PRs linked in the OP.

In addition to defining the missing ops, I've included at least one test for each of them, with the exception of RecvZc.

The RecvZc io_uring op currently only works on a few drivers and chipsets, notably:

Kernel Recipes 2024 - Efficient zero-copy networking using io_uring

• bnxt (Thor chipset NICs, e.g., BCM957508)
• gve
• mlx5 (ConnectX-7 or newer, possibly ConnectX-6 Dx or Bluefield-2 with crypto)

I'm reluctant to add a test without being able to confirm it at least works on one system. We probably also should gate it behind some environment variables like the kernel selftests since it requires specific system configuration to even run.

I tried setting up the zcrx context on a ConnectX-5 but that didn't work because of lack of tcp-data-split and lack of rx-gro-hw. I will be able to try again with a Bluefield-2 with crypto offload probably next week (ConnectX-6 Dx equivalent), and if that doesn't work I'll try to get access to the BCM957508.

But if anyone else watching currently has compatible hardware, we could easily add a short test for it and verify it works.

In any case, it's a complex feature and may require more changes upstream, but probably shouldn't be a blocker for the rest of this PR and the others linked above.