Implement seccomp notify

[yihuaf]

This is the first part of the change where we support seccomp notify (#307) and returning a fd for seccomp.

Next, we will implement the seccomp listeaner in the OCI spec.

[codecov-commenter]

Codecov Report

Merging #330 (88fa0af) into main (8250b48) will increase coverage by 0.01%.
The diff coverage is 68.85%.

@@            Coverage Diff             @@
##             main     #330      +/-   ##
==========================================
+ Coverage   70.37%   70.38%   +0.01%     
==========================================
  Files          46       46              
  Lines        6737     6790      +53     
==========================================
+ Hits         4741     4779      +38     
- Misses       1996     2011      +15     

[utam0k]

Is it possible to break the mod.rs down into a few more files?

[yihuaf]

Is it possible to break the mod.rs down into a few more files?

We can, but it is still a coherent block at the moment. The only relevant pub function here is initialize_seccomp. All the other bits are in the service of this function. Maybe next time when this file gets larger.

[utam0k]

We can, but it is still a coherent block at the moment. The only relevant pub function here is initialize_seccomp. All the other bits are in the service of this function. Maybe next time when this file gets larger.

Ok, I agree with you.

[utam0k]

LGTM