The common functions store socks of rump_servers, interfaces of rump_servers
and buses that intefaces connect and allow to destroy them with common
functions without specifying which socks, interfaces and buses we should
destroy.
This change reduces lots of similar setup/cleanup codes.
Due to PR 48104, some tests of ping/ping6 were failed but the tests now
should be successful. So reverse atf_check.
Bonus: the fix for PR 48104 also fixes another uknown failure.
The tests include checks for PR#48104 which is not fixed yet.
Note that one test unexpectedly fails for some reason
(unrelated to PR#48104). We have to fix it somehow.
It randomly fails (esp, often on a slow or loaded machine) due to
PR kern/49219, so disable it for now.
I forgot why I didn't include the test when I committed the test
at first and wrongly added it at v1.4.
As ping6 timeout feature (-X option) is added, we can do negative
tests without wasting time.
1 sec delay is added after network setup to avoid false positives.