Various optimizations

[reynir]

These are mostly optimizations from #223 but also some new ones since we have encrypt_into etc. functions.

main-bench.exe is built from 6099a4b (unfortunately without --release)

As you can see above there are improvements in execution time, but most notably the number of minor words allocations is almost halved. When testing against an openvpn server I didn't observe much of a difference except, curiously, a slowdown in upload speed (from 826 Mb/s to 757 Mb/s). Why that would I don't know.

[reynir]

When testing against an openvpn server I didn't observe much of a difference except, curiously, a slowdown in upload speed (from 826 Mb/s to 757 Mb/s). Why that would I don't know.

Ah! This was with the UDP configuration. With TCP there is a slight speedup (down: 919 Mb/s -> 1.07 Gb/s, up: 599 Mb/s -> 652 Mb/s)

[reynir]

I accidentally committed and pushed 15ba1ed and eba6e58 to main. They were a fix to the failing e2e test where I observed locally that it failed due to a Data_v1 packet with key id 0 arriving seemingly just after a successful rekey for key id 1. I don't know if it's the correct thing to do, but to me it seems for data packets we could be more lenient and just drop them.

[reynir]

Ah wait the e2e test already fails at the static client configuration. Locally, it initially also failed there for me, but that was due to firewall rules.

[hannesm]

looks fine to me, may revert the e2e changes and redirect again to /dev/null

[github-actions]

  0.00 %      0/21     src/cc_message.ml
 80.42 %   1483/1844   src/config.ml
 60.59 %    123/203    src/config_ext.ml
 72.93 %   1002/1374   src/engine.ml
100.00 %      0/0      src/miragevpn.ml
 92.88 %    365/393    src/packet.ml
 20.00 %      1/5      src/result.ml
 82.72 %     67/81     src/state.ml
 62.93 %    146/232    src/tls_crypt.ml
 76.74 %   3187/4153   Project coverage

[reynir]

I cleaned up the git history a bit by merging two commits and dropping the CI debugging commit.

It fails on OCaml 5.3~alpha1 due to effect suddenly being a keyword. I'll address this separately.