Provided by: mtpolicyd_2.05-1.1_all 
NAME
mtpolicyd - the mtpolicyd executable
VERSION
version 2.05
DESCRIPTION
mtpolicyd is a policy daemon for postfix access delegation.
It can be configured to accept connections on several ports from a postfix MTA. For each
port a VirtualHost can be configured and for each VirtualHost several Plugins can be
configured.
NAME
mtpolicyd - a modular policy daemon for postfix
EXAMPLE
In postfix main.cf:
smtpd_recipient_restrictions = check_policy_service inet:127.0.0.1:12345
In mtpolicyd.conf:
# listen on port 12345 (multiple ports can be separated by ',')
port="127.0.0.1:12345"
# defined host for this port
<VirtualHost 12345>
name=example_vhost
<Plugin spamhaus_bl>
module="RBL"
domain="sbl.spamhaus.org"
mode=reject
</Plugin>
</VirtualHost>
This check will execute a simple RBL lookup against dbl.spamhaus.org.
COMMANDLINE OPTIONS
mtpolicyd
[-h|--help]
[-c|--config=<file>]
[-f|--foreground]
[-l|--loglevel=<level>]
[-d|--dump_vhosts]
-h --help
Show available command line options.
-c --config=<file> (default: /etc/mtpolicyd/mtpolicyd.conf)
Specify the path to the configuration file.
-f --foreground
Do not fork to background and log to stdout.
-l --loglevel=<level>
Overwrite the log level specified in the configuration with the specified level.
-d --dump_vhosts
Parse VirtualHosts configuration, print it to stdout and exit.
CONFIGURATION FILE
The configuration file is implementend with Config::General which allows apache style
configuration files.
mtpolicyd accepts global configuration parameters in the style:
key=value
Comments begin with '#'.
VirtualHosts must be configured with VirtualHost sections:
<VirtualHost <portnumber>>
name=<name of the vhost>
</VirtualHost>
Each VirtualHost should contain at least on Plugin.
<VirtualHost <portnumber>>
name=<name of the vhost>
<Plugin <name of check> >
module = "<name of plugin>"
# plugin options
key=value
</Plugin>
</VirtualHost>
For individual plugin configuration options see the man page of the plugin:
Mail::MtPolicyd::Plugin::<name of plugin>
GLOBAL CONFIGURATION OPTIONS
user
user id to run as
group
group id to run as
pid_file
location of the pid file
log_level
Verbosity of logging: 0=>'err', 1=>'warning', 2=>'notice', 3=>'info', 4=>'debug'
host
ip address to bind to.
port
comma separated list of ports to listen on.
min_servers (default: 4)
The minimum number of client processes to start.
min_spare_servers (default: 4)
The minimum number of client processes that should hanging around idle and wait for
new connections.
If the number of free processes is below this threshold mtpolicyd will start to create
new child processes.
max_spare_servers (default: 12)
The maximum number of idle processes.
If the number of idle processes is over this threshold mtpolicyd will start to
shutdown child processes.
max_servers (default: 25)
The absolute maximum number of child processes to start.
max_requests (default: 1000)
max_keepalive (default: 0)
Number of requests after that mtpolicyd closes the connection or no limit if set to
zero.
Should be the same value as smtpd_policy_service_reuse_count_limit (postfix >2.12) in
postfix/smtpd configuration.
vhost_by_policy_context (default: 0)
Select VirtualHost by 'policy_context' request field.
The policy_context will be matched against the 'name' field of the VirtualHost.
For example in postfix main.cf use advanced syntax:
check_policy_service { inet:localhost:12345, policy_context=reputation }
...
check_policy_service { inet:localhost:12345, policy_context=accounting }
In mtpolicyd.conf:
port="127.0.0.1:12345" # only 1 port
vhost_by_policy_context=1
<VirtualHost 12345>
name=reputation
... plugins ...
</VirtualHost>
<VirtualHost 12345>
name=accounting
... plugins ...
</VirtualHost>
The policy_context feature will be available in postfix 3.1 and later.
If you just need small differentiations consider using the
Mail::MtPolicyd::Plugin::Condition plugin to match against plugin_context field.
request_timeout
Maximum total time for one request.
CONFIGURE CONNECTIONS
mtpolicyd has a global per process connection pool.
Connections could be registered within the connection pool using a <Connection> block
within the configuration. You must at least specify the name of the connection and the
module for the connection type.
<Connection [name of connection]>
module = "[connection type]"
# ... addditional parameters
</Connection>
Connection modules may require additional parameters.
Currently supported connection modules:
Sql Perl DBI based connections for SQL databases.
Mail::MtPolicyd::Connection::Sql
Memcached
Connection to a memcached server/cluster.
Mail::MtPolicyd::Connection::Memcached
Ldap
Connection to an LDAP directory server.
Mail::MtPolicyd::Connection::Ldap
SESSION MANAGEMENT
mtpolicyd implements session managemend to cache data across different checks for requests
with the same instance id.
mtpolicy is able to generate a session for each mail passed to it and store it within the
session cache. The attached session information will be available to all following
plugins across child processes, virtual hosts and ports.
Plugins will use this session information to cache lookup etc. across multiple requests
for the same mail. Postfix will send a query for each recipient and for each configured
check_policy_service call.
To enable the SessionCache specify a <SessionCache> block within your configuration:
<SessionCache>
module = "Memcached"
expire = "300"
lock_wait=50
lock_max_retry=50
lock_timeout=10
</SessionCache>
The example requires that a connection of type "Memcached" and the name "memcached" is
configured within the connection pool. For details read
Mail::MtPolicyd::SessionCache::Memcached.
As of version 2.00 it is possible to implement different session caches.
Currently there are 2 session cache modules:
Mail::MtPolicyd::SessionCache::Memcached
Mail::MtPolicyd::SessionCache::Redis
PROCESSING OF REQUEST
The policy daemon will process all plugins in the order they appear in the configuration
file. It will stop as soon as a plugin returns an action and will return this action to
the MTA.
SCORING
Most plugins can be configured to not return an action if the performed check matched.
For example the RBL module could be set to passive mode and instead a score could be
applied to the request:
<Plugin spamhaus>
module = "RBL"
mode = "passive"
domain="zen.spamhaus.org"
score=5
</Plugin>
Check the documentation of the plugin for certain score/mode parameters. Plugin may
provide more than one mode/score parameters if the do several checks.
Now if you configure more than one RBL check the score will add up. Later an action can
be taken based on the score. The ScoreAction plugin will return an action based on the
score and the AddScoreHeader plugin will prepend the score as a header to the mail:
<Plugin ScoreReject>
module = "ScoreAction"
threshold = 15
action = "reject sender ip %IP% is blocked (score=%SCORE%%SCORE_DETAIL%)"
</Plugin>
<Plugin ScoreTag>
module = "AddScoreHeader"
spam_score=5
</Plugin>
UPGRADING
FROM 1.x to 2.x
With mtpolicyd 2.x configuration of connections and session cache has been changed.
Database Connections
In mtpolicyd 2.00 the connections defined globaly in the configuration file have been
replaced by a dynamic connection pool.
The global options db_* ldap_* and memcached_* have been removed.
Instead connections are registered within a connection pool.
You can define them using <Connection> blocks:
<Connection myconn>
module = "<adapter>"
# parameter = "value"
# ...
</Connection>
In mtpolicyd 1.x:
db_dsn=DBI:mysql:mtpolicyd
db_user=mtpolicyd
db_password=secret
In mtpolicyd 2.x:
<Connection db>
dsn = "DBI:mysql:mtpolicyd"
user = "mtpolicyd"
password = "secret"
</Connection>
All SQL modules will by default use the connection registered as "db".
See modules in Mail::MtPolicyd::Connection::* for available connection adapters.
Session Cache
Starting with mtpolicyd 2.x it is possible to use other session caches then memcached.
The global session_* parameters have been removed.
Instead the session cache is defined by a <SessionCache> block:
<SessionCache>
module = "<module>"
# parameter = "value"
# ...
</SessionCache>
A memcached session cache in mtpolicyd v1.x:
memcached_servers="127.0.0.1:11211"
session_lock_wait=50
session_lock_max_retry=50
session_lock_timeout=10
In mtpolicyd 2.x:
<Connection memcached>
servers = "127.0.0.1:11211"
</Connection>
<SessionCache>
module = "Memcached"
# defaults to connection "memcached"
# memcached = "memcached"
lock_wait = "50"
lock_max_retry = "50"
lock_timeout = "10"
</SessionCache>
If no <SessionCache> is defined it will default to the dummy session cache module "None".
See modules in Mail::MtPolicyd::SessionCache::* for available session cache modules.
AUTHOR
Markus Benning <ich@markusbenning.de>
COPYRIGHT AND LICENSE
This software is Copyright (c) 2014 by Markus Benning <ich@markusbenning.de>.
This is free software, licensed under:
The GNU General Public License, Version 2, June 1991