While the alias is available after enabling the unit, we don't
actually do that in our testing environment (adding a symlink manually
would work too, then again, why not just use the proper name?).
We could make the same change for charon (actually setting it for charon
in strongswan.conf.testing would work for charon-systemd too), however,
there are dozens of test cases that currently set charondebug in
ipsec.conf.
The default of 56 bytes already exceeds the threshold of 90 bytes (8 bytes
ICMP + 40 bytes IPv6 = 104 bytes). By reducing the size we make sure the
packet is not compressed (40 + 8 + 40 = 88).
This also fixes a strange failure of this scenario due to the recently
added post-test `ip xfrm state` check. The kernel stores a reference to
the used SAs on the inbound skbuffs and since these are garbage collected
it could take a while until all references to an SA disappear and the SA
is finally destroyed. But while SAs might not get destroyed immediately
when we delete them, they are actually marked as dead and therefore won't
show up in `ip xfrm state`. However, that's not the case for the tunnel
SAs the kernel attaches to IPComp SAs, which we don't explicitly delete,
and which aren't modified by the kernel until the IPComp SA is destroyed.
So what happened when the last ping unintentionally got compressed is that
the skbuff had a reference to the IPComp SA and therefore the tunnel SA.
This skbuff often was destroyed after the `ip xfrm state` check ran and
because the tunnel SA would still get reported the test case failed.
Some fetcher plugins (such as curl) might build upon OpenSSL to implement
HTTPS fetching. As we set (and can't unset) threading callbacks in our
openssl plugin, we must ensure that OpenSSL functions don't get called after
openssl plugin unloading.
We achieve that by loading curl and all other fetcher plugins after the base
crypto plugins, including openssl.
