# Fail2Ban filter for selected Postfix SMTP rejections
#
#
[INCLUDES]
# Read common prefixes. If any customizations available -- read them from
# common.local
before = common.conf
[Definition]
_daemon = postfix(-\w+)?/[^/\[:\s]+(?:/smtp[ds])?
_port = (?::\d+)?
_pref = [A-Z]{4,}
prefregex = ^%(__prefix_line)s<mdpr-<mode>> <F-CONTENT>.+</F-CONTENT>$
# Extended RE for normal mode to match reject by unknown users or undeliverable address, can be set to empty to avoid this:
exre-user = |[Uu](?:ser unknown|ndeliverable address) ; pragma: codespell-ignore
mdpr-normal = (?:\w+: (?:milter-)?reject:|(?:improper command pipelining|too many errors) after \S+)
mdre-normal=^%(_pref)s from [^[]*\[<HOST>\]%(_port)s: [45][50][04] [45]\.\d\.\d+ (?:(?:<[^>]*>)?: )?(?:(?:Helo command|(?:Sender|Recipient) address) rejected: )?(?:Service unavailable|Access denied|(?:Client host|Command|Data command) rejected|Relay access denied|Malformed DNS server reply|(?:Host|Domain) not found|need fully-qualified hostname|match%(exre-user)s)\b
^from [^[]*\[<HOST>\]%(_port)s:?
mdpr-auth = warning:
mdre-auth = ^[^[]*\[<HOST>\]%(_port)s: SASL ((?i)LOGIN|PLAIN|(?:CRAM|DIGEST)-MD5) authentication failed:(?! Connection lost to authentication server| Invalid authentication mechanism)
mdre-auth2= ^[^[]*\[<HOST>\]%(_port)s: SASL ((?i)LOGIN|PLAIN|(?:CRAM|DIGEST)-MD5) authentication failed:(?! Connection lost to authentication server)
# todo: check/remove "Invalid authentication mechanism" from ignore list, if gh-1243 will get finished (see gh-1297).
# Mode "rbl" currently included in mode "normal", but if needed for jail "postfix-rbl" only:
mdpr-rbl = %(mdpr-normal)s
mdre-rbl = ^%(_pref)s from [^[]*\[<HOST>\]%(_port)s: [45]54 [45]\.7\.1 Service unavailable; Client host \[\S+\] blocked\b
# Mode "rbl" currently included in mode "normal" (within 1st rule)
mdpr-more = %(mdpr-normal)s
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|AUTH)\b)[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)
mdre-extra = %(mdre-auth)s
%(mdre-normal)s
mdpr-aggressive = (?:%(mdpr-auth)s|%(mdpr-normal)s|%(mdpr-ddos)s)
mdre-aggressive = %(mdre-auth2)s
%(mdre-normal)s
mdpr-errors = too many errors after \S+
mdre-errors = ^from [^[]*\[<HOST>\]%(_port)s$
failregex = <mdre-<mode>>
# Parameter "mode": more (default combines normal and rbl), auth, normal, rbl, ddos, extra or aggressive (combines all)
# Usage example (for jail.local):
# [postfix]
# mode = aggressive
#
# # or another jail (rewrite filter parameters of jail):
# [postfix-rbl]
# filter = postfix[mode=rbl]
#
# # jail to match "too many errors", related postconf `smtpd_hard_error_limit`:
# # (normally included in other modes (normal, more, extra, aggressive), but this jail'd allow to ban on the first message)
# [postfix-many-errors]
# filter = postfix[mode=errors]
# maxretry = 1
#
mode = more
ignoreregex =
[Init]
journalmatch = _SYSTEMD_UNIT=postfix.service _SYSTEMD_UNIT=postfix@-.service
# Author: Cyril Jaquier
