filter.d/postfix.conf: mode `ddos` (and `aggressive`) extended to consider abusive handling of clients hitting command limit (gh-3040)

config/filter.d/postfix.conf

@@ -38,7 +38,7 @@ mdre-more = %(mdre-normal)s
 
 # Includes some of the log messages described in
 # <http://www.postfix.org/POSTSCREEN_README.html>.
-mdpr-ddos = (?:lost connection after(?! DATA) [A-Z]+|disconnect(?= from \S+(?: \S+=\d+)* auth=0/(?:[1-9]|\d\d+))|(?:PREGREET \d+|HANGUP) after \S+)
+mdpr-ddos = (?:lost connection after(?! DATA) [A-Z]+|disconnect(?= from \S+(?: \S+=\d+)* auth=0/(?:[1-9]|\d\d+))|(?:PREGREET \d+|HANGUP) after \S+|COMMAND (?:TIME|COUNT|LENGTH) LIMIT)
 mdre-ddos = ^from [^[]*\[<HOST>\]%(_port)s:?
 
 mdpr-extra = (?:%(mdpr-auth)s|%(mdpr-normal)s)

fail2ban/tests/files/logs/postfix

@@ -169,6 +169,12 @@ Dec 23 19:39:13 xxx postfix/postscreen[21057]: PREGREET 14 after 0.08 from [192.
 # failJSON: { "time": "2004-12-24T00:54:36", "match": true , "host": "192.0.2.3" }
 Dec 24 00:54:36 xxx postfix/postscreen[22515]: HANGUP after 16 from [192.0.2.3]:48119 in tests after SMTP handshake
 
+# failJSON: { "time": "2005-06-08T23:14:28", "match": true , "host": "192.0.2.77", "desc": "abusive clients hitting command limit, see see http://www.postfix.org/POSTSCREEN_README.html (gh-3040)" }
+Jun  8 23:14:28 proxy2 postfix/postscreen[473]: COMMAND TIME LIMIT from [192.0.2.77]:3608 after CONNECT
+# failJSON: { "time": "2005-06-08T23:14:54", "match": true , "host": "192.0.2.26", "desc": "abusive clients hitting command limit (gh-3040)" }
+Jun  8 23:14:54 proxy2 postfix/postscreen[473]: COMMAND COUNT LIMIT from [192.0.2.26]:15592 after RCPT
+
+
 # filterOptions: [{}, {"mode": "ddos"}, {"mode": "aggressive"}]
 # failJSON: { "match": false, "desc": "don't affect lawful data (sporadical connection aborts within DATA-phase, see gh-1813 for discussion)" }
 Feb 18 09:50:05 xxx postfix/smtpd[42]: lost connection after DATA from good-host.example.com[192.0.2.10]