How is check-tun expected to work in production?

[kemsta]

Hi!

Trying to understand the intended check_tun model.

From what I see:

• Monalive’s embedded pkg/checktun expects a Monalive-specific packet format:
  • constant mark (0xFFFFFFFF)
  • real IP + lvs_method encoded in IPv4 options / IPv6 dst options
• the original external check-tun from https://github.com/andriyanov/check-tun works differently:
  • it routes by fwmark
  • it does not seem compatible with Monalive’s packet format
• at the same time, the embedded Monalive checktun path appears to be broken in the current repo state because of the raw socket initialization issue

So the short question is:

what was the intended production setup here?

Right now it looks like:

1. embedded checktun is broken in the current code
2. original external check-tun is not compatible with Monalive’s current packet format

Am I missing some deployment detail, or was this path never fully wired end-to-end?

[ezhk]

the embedded Monalive checktun path appears to be broken in the current repo state because of the raw socket initialization issue

Could you describe this issue or show error, that you’ve received?

[kemsta]

I’m getting "failed to get socket", which is an quite expected error, because the code is supposed to use pre-created sockets, but here the sockets are created and never saved anywhere.