# HG changeset patch
# User Matthew Wild <mwild1@gmail.com>
# Date 1680351113 -3600
# Node ID 12f7d8b901e09528ce65ff5883e007277e152195
# Parent  4bba2d27ffaf5d6285bd6ac5efa1df706e776bb4
mod_audit: Support for adding location (GeoIP) to audit events

This can be more privacy-friendly than logging full IP addresses, and also
more informative to a user - IP addresses don't mean much to the average
person, however if they see activity from outside their expected country, they
can immediately identify suspicious activity.

As with IPs, this field is configurable for deployments that would like to
disable it. Location is also not logged when the geoip library is not
available.

diff -r 4bba2d27ffaf -r 12f7d8b901e0 mod_audit/mod_audit.lua
--- a/mod_audit/mod_audit.lua	Sat Apr 01 12:10:56 2023 +0200
+++ b/mod_audit/mod_audit.lua	Sat Apr 01 13:11:53 2023 +0100
@@ -7,6 +7,15 @@
 local attach_ipv4_prefix = module:get_option_number("audit_log_ipv4_prefix", nil);
 local attach_ipv6_prefix = module:get_option_number("audit_log_ipv6_prefix", nil);
 
+local have_geoip, geoip = pcall(require, "geoip.country");
+local attach_location = have_geoip and module:get_option_boolean("audit_log_location", true);
+
+local geoip4_country, geoip6_country;
+if have_geoip and attach_location then
+	geoip4_country = geoip.open(module:get_option_string("geoip_ipv4_country", "/usr/share/GeoIP/GeoIP.dat"));
+	geoip6_country = geoip.open(module:get_option_string("geoip_ipv6_country", "/usr/share/GeoIP/GeoIPv6.dat"));
+end
+
 local time_now = os.time;
 local ip = require "util.ip";
 local st = require "util.stanza";
@@ -58,6 +67,13 @@
 		end
 		stanza:text_tag("remote-ip", network or remote_ip);
 	end
+	if attach_location and session.ip then
+		local remote_ip = ip.new(session.ip);
+		local geoip_country = ip.proto == "IPv6" and geoip6_country or geoip4_country;
+		stanza:tag("location", {
+			country = geoip_country:query_by_addr(remote_ip.normal);
+		}):up();
+	end
 	if session.client_id then
 		stanza:text_tag("client", session.client_id);
 	end