RegEx engine improvements

[DL6ER]

@jpgpi250

This method cannot be used if a regex like .*; querytype=AAAA is used, because it would result in allowing all AAAA queries for certain clients, when using it as a whitelist regex (whitelist always wins). In order to use the above regex, it needs to be used as a blacklist regex entry, targeting specific clients.

Blocking AAAA for all clients and allowing it only for some seems a legit use case (at least theoretically).

@jpgpi250

If I want to apply this regex to all but some clients (use it as a blacklist regex), I need to create a group with all the clients, except the ones I want to allow making AAAA queries. This list (can be) very large, and probably will not be effective (new clients aren't member of this group)

You should do the inverse: Create a group with the clients that should not match and add them in there. Then add the new regex only to Default which covers also the new clients.

@jpgpi250

The above regex example would than target the ! AllowAAAAqueries group, making it a lot more effective in an environment where new clients come and go on a regular bases.

Even when I tend to disagree on your conclusion above, I do agree that is useful to be able to invert a regular expression altogether. Hence, I added the new keyword ;invert
For instance,

^abc$;querytype=AAAA;invert

will not block abc with type AAAA (but everything else) for the clients attached to it.

This has the same effect as inverting the client selection, however, it is even somewhat more powerful.