Hello, so while testing and reviewing the ZDTM Test Suite for CRIU, I noticed that there is no regression tests for UDP Multicast (e.g., sockets using IP_ADD_MEMBERSHIP).

Is it since some inherent feature of CRIU doesnt support Multicast dump/restore or just not added yet?

CRIU already has extensive coverage for UDP sockets in general, but multicast group membership represents kernel-maintained socket state that may be lost across checkpoint/restore without explicit handling.

So that might mean, that in case of a process which uses Multicast sockets, post restore the multicast funtionality might be lost and we might not be able to restore the membership addresses the way we want to as per original process.

This kind of failure might be difficult to detect without active explicit tests, or prior knowledge of the process workings.
I couldn’t find any tests or documentation for this.

As per the understanding, if something isnt being tested by ZDTM then CRIU prolly doesnt support it, please let me know if I'm missing something.