Provide ability to specify RBL return code

[matteocorti]

From @matteocorti on October 16, 2015 13:30

Original reporter: michael@orlitzky.com

Some RBLs return different codes to indicate various levels of blacklisting. This can cause trouble when a single RBL returns both black- and white-listings from the same zone. For example,

1. http://mailspike.net/usage.html
2. http://wiki.ctyme.com/index.php/Spam_DNS_Lists

It would be nice to be able to specify the return code(s) that we're interested in. So for mailspike, we would only want to trigger nagios warnings for 127.0.0.1{0,1,2}.

We use plugins.ini to list our RBLs so it would be awesome if the return codes could be specified there, too.

An example syntax is used by the postfix postscreen daemon. The syntax is specified somewhat here:

• http://www.postfix.org/postconf.5.html#postscreen_dnsbl_sites

(obviously, you wouldn't need the points multipliers at the end). Our postscreen configuration might be easier to parse than the description from the documentation:

postscreen_dnsbl_sites =
        psbl.surriel.com*2,
        bl.spamcop.net*2,
        zen.spamhaus.org*2,
        b.barracudacentral.org*2,
    bl.mailspike.net=127.0.0.[2;10;11]*2,
    bl.mailspike.net=127.0.0.12,
    bl.spameatingmonkey.net,
    dnsbl.sorbs.net,
    dnsbl.ahbl.org,
    ubl.unsubscore.com,
    dnsbl-1.uceprotect.net,
    hostkarma.junkemailfilter.com=127.0.0.2,
    db.wpbl.info

Copied from original issue: matteocorti/nagios_plugins#121