policyd-geoip

Small GoLang program to use MaxMind's GeoIP2 database (and, optionally, Whois lookups and top domain guessing) for Postfix policy delegation.

Whois processing is time consuming, on my systems it adds about two seconds to the processing.

How to use

Add a service to Postfix master.cf:

# Geoip
policy-geoip unix -	n	n	-	-	spawn
  user=nobody argv=/path/to/bin/policyd-geoip --configuration /path/to/policyd-geoip.yaml

If --configuration flag is omitted, the program tries to access /etc/policyd-geoip.yaml.

Then you can use the policy like so in main.cf:

smtpd_..._restrictions =
  ...
  check_policy_service unix:private/policy-geoip
  ...

policy-geoip_time_limit = 3600

If you want to be able to also process the sender address you need to use the policy in a later step of the Postfix process, after the client has sent the MAIL FROM command, for example smtpd_sender_restrictions.

YAML configuration example

# Additional text to add to the REJECT message
reject_message: "Not interested"
# Should the program print debug information
debug: false
# ISO codes of countries not allowed to access the Postfix server
blacklist:
  - SE # Sweden
  - US # USA
# Special codes used by Maxmind:
  - A1 # Anonymous Proxy
  - A2 # Satellite Provider
  - O1 # Other Country
# Location of the Maxmind's Geoip2 database
geoip2_database: "/usr/share/GeoIP/GeoLite2-Country.mmdb"
# Domain that allows the client to skip the country check
whitelist:
  - google.com
# All logs are sent to Syslog (the program is not supposed to be run in console)
syslog_facility: mail
syslog_tag: policyd-geoip2
# Optionally can use data from Whois to guess the country
# Omit to just use geoip2 database.
whois_program: /usr/bin/whois