Zimbra :: Tech Center:Cluebringer Policy Daemon

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This article applies to the following ZCS versions.

ZCS 8.0 Article ZCS 8.0 ZCS 7.0 Article ZCS 7.0

Postfix Cluebringer Policyd in Zimbra

Policyd is an anti-spam policy daemon for Postfix (written in C) that does Greylisting, Sender-(envelope, SASL or host / ip)-based throttling (on messages and/or volume per defined time unit), Recipient rate limiting, Spamtrap monitoring / blacklisting, HELO auto blacklisting and HELO randomization preventation.

It is included as a part of the Zimbra package, but it is not enabled by default.

Enabling policyd

First ensure sqlite is installed (It is listed as a suggested install).

To enable policyd, simply tell the Zimbra installation you want it enabled:

zmprov ms <mta server> +zimbraServiceEnabled cbpolicyd

After 1 to 2 minutes the zmconfigd process will detect that you want this service enabled, and automatically install the database and start the service.

Localconfig keys related to policyd

  • cbpolicyd_pid_file - location of PID file.
  • cbpolicyd_log_file - location of log file.
  • cbpolicyd_db_file - location of SQLite database
  • cbpolicyd_min_servers - Minimum number of servers to have running. ZCS8.0.5 and higher
  • cbpolicyd_min_spare_servers - Minimum number of spare servers to have on hand. ZCS8.0.5 and higher
  • cbpolicyd_max_spare_servers - Maximum number of spare servers to have on hand that are idle. ZCS8.0.5 and higher
  • cbpolicyd_max_servers - Maximum number of servers to allow. ZCS8.0.5 and higher
  • cbpolicyd_max_requests - Maximum number of requests to process per server. ZCS8.0.5 and higher
  • cbpolicyd_cache_file - location of cache
  • cbpolicyd_log_level - loglevel (default 3)
  • cbpolicyd_log_mail - Default is main. Log to policyd's main log mechanism, accepts NO args
  • cbpolicyd_log_detail - What detail of logging to provide. Default "modules"
  • cbpolicyd_bind_port - Bind port for cbpolicyd. default 10031
  • cbpolicyd_timeout - Timeout when talking to clients. Default 120 seconds. ZCS7 and ZCS 8 < ZCS8.0.4
  • cbpolicyd_timeout_idle - Idle timeout. Defaults to 1020 seconds. ZCS8.0.4 and higher
  • cbpolicyd_timeout_busy - Busy timeout. Defaults to 120 seconds. ZCS8.0.4 and higher
  • cbpolicyd_bypass_timeout - Bypass timeout. Defaults to 30 seconds.
  • cbpolicyd_bypass_mode - Bypass fail mode. Default is "tempfail"
  • cbpolicyd_module_accesscontrol - Enable Access Control module. Default 0 (disabled)
  • cbpolicyd_module_greylisting - Enable greylisting. Default 0 (disabled)
  • cbpolicyd_module_greylisting_training - If greylisting is enabled, whether or not to run in training mode. Default 0 (Do not run in training mode). ZCS8 only
  • cbpolicyd_module_greylisting_defer_msg - Message to give when deferring email. Default "Greylisting in effect, please come back later". ZCS8 only
  • cbpolicyd_module_greylisting_blacklist_msg - Message to give when client is on blacklist. Default "Greylisting in effect, sending server blacklisted". ZCS8 only
  • cbpolicyd_module_checkhelo - Enable checkhelo module. Default 0 (disabled)
  • cbpolicyd_module_checkspf - Enable CheckSPF module. Default 0 (disabled)
  • cbpolicyd_module_quotas - Enable Quotas module. Default 1 (enabled)
  • cbpolicyd_module_amavis - Enable amavis module. Default 0 (disabled) ZCS8.0.4 and higher.
  • cbpolicyd_module_accounting - Enable accounting module. Default 0 (disabled). ZCS8.0.4 and higher.

Table data for cbpolicyd

The ".tables" command will display the tables that currently exist in the sqlite DB for cbpolicyd policies. There is also a "master" table named sqlite_sequence that counts the policies:

  • Master table with no added policies. Default amavis_rules policy only exists in ZCS8.0.5 and higher:
sqlite> select * from sqlite_sequence;
policies|5
policy_members|5
policy_groups|2
policy_group_members|3
quotas|2
quotas_limits|3
checkhelo_blacklist|4
amavis_rules|1

The above shows that there are:

5 policies
5 policy members
2 policy groups
3 policy group members
2 quota policies
2 quota limit policies
4 checkhelo_blacklist policies
1 amavis rules policy
  • Policy tables available in ZCS8.0.5 and later:
sqlite> .tables
access_control             greylisting_autowhitelist
accounting                 greylisting_tracking
accounting_tracking        greylisting_whitelist
amavis_rules               policies
checkhelo                  policy_group_members
checkhelo_blacklist        policy_groups
checkhelo_tracking         policy_members
checkhelo_whitelist        quotas
checkspf                   quotas_limits
greylisting                quotas_tracking
greylisting_autoblacklist  session_tracking
  • Policy tables available in ZCS8.0.4 and previous:
sqlite> .tables
access_control             greylisting_whitelist
checkhelo                  policies
checkhelo_blacklist        policy_group_members
checkhelo_tracking         policy_groups
checkhelo_whitelist        policy_members
checkspf                   quotas
greylisting                quotas_limits
greylisting_autoblacklist  quotas_tracking
greylisting_autowhitelist  session_tracking
greylisting_tracking

Examining defined policies for a given table

You can use a select statement to view the defined policies for a given table.

For our example, we will examine the quota (rate limiting) policies that are installed by default. The Quota (rate-limiting) policy consists of two separate tables. The first table is named "quotas", the second table is named "quotas_limits".

sqlite> select * from quotas;
1|5|Recipient quotas|Recipient:user@domain|3600|REJECT||0||0
2|5|Quota on all /24s|SenderIP:/24|3600|REJECT||0||0
  • The first column is the identifier for the quota policy (used in quota_limits for reference back).
  • The fifth column is the time interval for the policy. In this case, they both default to 3600 seconds.
sqlite> select * from quotas_limits;
1|1|MessageCount|10||0
2|1|MessageCumulativeSize|8000||0
3|2|MessageCount|12||0
  • The second column is referring to the identifier in the quota table. More than one rule can be defined per quota identifier as seen above.
  • The fourth column is the "rate limit". For example, in the 3rd row, "12" is the max number of hits coming from a specific sender IP within 3600 seconds.

Adding policy definitions via the command line

The following examples show how to implement various policies via the command line

Add a Zimbra Policy Group

First, we will add a Zimbra policy group to cbpolicyd and associate any newly added rules with this group. This should only be done once. As Zimbra:

  • Create a file called zimbra-group.sql with the following contents:
BEGIN TRANSACTION;
INSERT INTO "policies" (Name,Priority,Description) VALUES('Zimbra CBPolicyd Policies', 0, 'Zimbra CBPolicyd Policies');
INSERT INTO "policy_members" (PolicyID,Source,Destination) VALUES(6, 'any', 'any');
COMMIT;
  • Import the policy group into cbpolicyd:
sqlite3 /opt/zimbra/data/cbpolicyd/db/cbpolicyd.sqlitedb < zimbra-group.sql

This will create a new "zimbra policy" group with priority 0 (highest priority) that gets applied to all email.

Defining a rate-limit (quota) with cbpolicyd

By default "quota" or "rate limiting" is enabled, but there is no policy defining how it should behave. The below example adds two policies :

  • Rate limit any sender from sending more then 20 emails every 60 seconds. Messages beyond this limit are deferred.
  • Rate limit any @domain from receiving more then 50 emails in a 60 second period. Messages beyond this rate are rejected.

As Zimbra:

  • Create a file called rate-limit.sql with the following contents.
BEGIN TRANSACTION;
INSERT INTO "quotas" (PolicyID,Name,Track,Period,Verdict,Data) VALUES (6, 'Sender:user@domain','Sender:user@domain', 60, 'DEFER', 'Deferring: Too many messages from sender in last 60');
INSERT INTO "quotas" (PolicyID,Name,Track,Period,Verdict) VALUES (6, 'Recipient:@domain', 'Recipient:@domain', 60, 'REJECT');
INSERT INTO "quotas_limits" (QuotasID,Type,CounterLimit) VALUES(3, 'MessageCount', 20);
INSERT INTO "quotas_limits" (QuotasID,Type,CounterLimit) VALUES(4, 'MessageCount', 50);
COMMIT;
  • Import the rules into cbpolicyd:
sqlite3 /opt/zimbra/data/cbpolicyd/db/cbpolicyd.sqlitedb < rate-limit.sql

Defining a greylisting policy with cbpolicyd

By default, the greylisting module is not enabled, and there are no greylisting policies. To enable greylisting, do the following as Zimbra:

  • zmlocalconfig -e cbpolicyd_module_greylisting=1

ZCS8 only: If you want to start building your greylisting table without enforcing policy (I.e., train your server before enabling greylisting):

  • zmlocalconfig -e cbpolicyd_module_greylisting_training=1

When you are ready to have greylisting applied, set the value for cbpolicyd_module_greylisting_training to zero.

  • Create a file called zimbra-greylist.sql with the following contents
BEGIN TRANSACTION;
INSERT INTO "greylisting" (PolicyID,Name,UseGreylisting,GreylistPeriod,Track,GreylistAuthValidity,
GreylistUnAuthValidity,AutoWhitelistPeriod,AutoWhitelistCount,AutoWhitelistPercentage,UseAutoBlacklist,
AutoBlacklistPeriod,AutoBlacklistCount,AutoBlacklistPercentage)
 VALUES(6,"Zimbra Greylisting",1,120,"SenderIP:/32",604800,86400,604800,100,95,1,604800,100,100)
COMMIT;
  • Import the policy:
sqlite3 /opt/zimbra/data/cbpolicyd/db/cbpolicyd.sqlitedb < zimbra-greylist.sql

Database cleanup for cbpolicyd

Old and outdated entries are not automatically purged from CBPolicyd's database. Thanks to Cine @ Zextras for noting this. A tool called "cbpadmin" is provided to take care of this operation, so one may wish to schedule a cronjob on the MTAs to do this

35 3 * * * /opt/zimbra/cbpolicyd/bin/cbpadmin --config=/opt/zimbra/conf/cbpolicyd.conf  --cleanup >/dev/null

Performance tuning

In ZCS 8.0.5, you can easily tune the cbpolicyd daemon for high volume MTAs. By default it is tuned for medium volume servers.

For a large volume server:

zmlocalconfig -e cbpolicyd_min_servers=8
zmlocalconfig -e cbpolicyd_min_spare_servers=8
zmlocalconfig -e cbpolicyd_max_spare_servers=16
zmlocalconfig -e cbpolicyd_max_servers=64
zmlocalconfig -e cbpolicyd_max_requests=1000

Disabling cbpolicyd

Disabling cbpolicyd is as simple as removing it as an enabled service:

  • zmprov ms <mta server> -zimbraServiceEnabled cbpolicyd

This will trigger zmconfigd to rewrite the postfix configuration and shut down cbpolicyd.

See Also

Detailed cbpolicyd for zimbra information

Verified Against: ZCS 8.0, ZCS 7.0 Date Created: 2/26/2013
Article ID: https://wiki.zimbra.com/index.php?title=Cluebringer_Policy_Daemon Date Modified: 2013-06-25



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