This requires config changes if filelog is used with a path that
contains dots. This path must now be defined in the `path` setting of an
arbitrarily named subsection of `filelog`. Without that change the
whole strongswan.conf file will fail to load, which some users might
not notice immediately.
There was a potential chance for a race condition if the ensured section
was purged for some reason before using it later.
This also changes the behavior for NULL/empty strings via load_string*
with merge == FALSE, which now purges the config/section.
Similar to the `also` keyword in ipsec.conf, the new syntax allows adding
one or more references to other sections, which means all the settings and
subsections defined there are inherited (values may be overridden, even
with an empty value to clear it).
It's important to note that all subsections are inherited, so if this is
used to reference a connection in swanctl.conf all auth rounds and
children are inherited. There is currently no syntax to limit the
inclusion level or clear inherited sections (but as mentioned, settings
in those inherited sections may be overridden).
Another property is that inherited settings or sections always follow
explicitly defined entries in the current section when they are enumerated.
This is relevant if the order is important (e.g. for auth rounds if `round`
is not specified).
References are evaluated dynamically at runtime, so referring to
sections later in the config file or included via other files is no
problem.
The colon used as separator to reference other sections may be used in
section names by writing :: (e.g. for Windows log file paths).
This is based on a patch originally written in 2016.
As the behavior was inconsistent for empty strings or strings with characters
appended to a number, testing the code failed on some platforms. The new rules
are more strict, returning the default if additional characters or an empty
string was found for a setting.
This is not thread safe. If threads are reading from pointers to existing
values they could get a partially updated invalid value.
Refactored assignment to a separate function.
Tobias Brunner