1412 lines
		
	
	
	
		
			78 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
			
		
		
	
	
			1412 lines
		
	
	
	
		
			78 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
<?xml version="1.0" ?>
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml">
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<head>
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<title>postfwd - postfix firewall daemon</title>
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<meta http-equiv="content-type" content="text/html; charset=utf-8" />
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<link rev="made" href="mailto:root@localhost" />
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</head>
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<body style="background-color: white">
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<!-- INDEX BEGIN -->
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<div name="index">
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<p><a name="__index__"></a></p>
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<ul>
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	<li><a href="#name">NAME</a></li>
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	<li><a href="#synopsis">SYNOPSIS</a></li>
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	<li><a href="#description">DESCRIPTION</a></li>
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	<ul>
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		<li><a href="#introduction">INTRODUCTION</a></li>
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		<li><a href="#configuration">CONFIGURATION</a></li>
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		<li><a href="#items">ITEMS</a></li>
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		<li><a href="#files">FILES</a></li>
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		<li><a href="#actions">ACTIONS</a></li>
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		<li><a href="#macros_acls">MACROS/ACLS</a></li>
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		<li><a href="#plugins">PLUGINS</a></li>
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		<li><a href="#command_line">COMMAND LINE</a></li>
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		<li><a href="#refresh">REFRESH</a></li>
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		<li><a href="#examples">EXAMPLES</a></li>
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		<li><a href="#parser">PARSER</a></li>
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		<li><a href="#integration">INTEGRATION</a></li>
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		<li><a href="#testing">TESTING</a></li>
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		<li><a href="#performance">PERFORMANCE</a></li>
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		<li><a href="#see_also">SEE ALSO</a></li>
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	</ul>
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	<li><a href="#license">LICENSE</a></li>
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	<li><a href="#author">AUTHOR</a></li>
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</ul>
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<hr name="index" />
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</div>
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<!-- INDEX END -->
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<p>
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</p>
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<h1><a name="name">NAME</a></h1>
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<p>postfwd - postfix firewall daemon</p>
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<p>
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</p>
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<hr />
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<h1><a name="synopsis">SYNOPSIS</a></h1>
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<p>postfwd [OPTIONS] [SOURCE1, SOURCE2, ...]</p>
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<pre>
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        Ruleset: (at least one, multiple use is allowed):
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        -f, --file <file>            reads rules from <file>
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        -r, --rule <rule>            adds <rule> to config</pre>
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<pre>
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        Scoring:
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        -s, --scores <v>=<r>         returns <r> when score exceeds <v></pre>
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<pre>
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        Control:
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        -d, --daemon                 run postfwd as daemon
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        -k, --kill                   stops daemon
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            --reload                 reloads configuration
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            --dumpstats              displays usage statistics
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            --dumpcache              displays cache contents
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            --delcache <item>        removes an item from the request cache
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            --delrate <item>         removes an item from the rate cache</pre>
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<pre>
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        Networking:
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        -i, --interface <dev>        listen on interface <dev>
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        -p, --port <port>            listen on port <port>
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            --proto <proto>          socket type (tcp or unix)
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        -u, --user <name>            set uid to user <name>
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        -g, --group <name>           set gid to group <name>
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            --umask <mask>           set umask for file permissions
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        -R, --chroot <path>          chroot the daemon to <path>
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            --pidfile <path>         create pidfile under <path>
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            --facility <f>           syslog facility
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            --socktype <s>           syslog socktype
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        -l, --logname <label>        label for syslog messages
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            --loglen <int>           truncates syslogs after <int> chars</pre>
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<pre>
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        Caching:
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        -c, --cache <int>            sets the request-cache timeout to <int> seconds
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            --cache-no-size          ignores size attribute for caching
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            --cache-no-sender        ignores sender address in cache
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            --cache-rdomain-only     ignores localpart of recipient address in cache
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            --cache-rbl-timeout      default rbl timeout, if not specified in ruleset
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            --cache-rbl-default      default rbl response pattern to match (regexp)
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            --cacheid <item>, ..     list of attributes for request cache identifier
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            --cleanup-requests       cleanup interval in seconds for request cache
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            --cleanup-rbls           cleanup interval in seconds for rbl cache
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            --cleanup-rates          cleanup interval in seconds for rate cache</pre>
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<pre>
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        Optional:
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        -t, --test                   testing, always returns "dunno"
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        -v, --verbose                verbose logging, use twice (-vv) to increase level
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        -S, --summary <int>          show some usage statistics every <int> seconds
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            --norulelog              disbles rule logging
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            --norulestats            disables per rule statistics
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            --noidlestats            disables statistics when idle
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        -n, --nodns                  disable dns
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            --nodnslog               disable dns logging
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            --dns_async_txt          perform dnsbl A and TXT lookups simultaneously
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            --dns_timeout            timeout in seconds for asynchonous dns queries
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            --dns_timeout_max        maximum of dns timeouts until a dnsbl will be deactivated
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            --dns_timeout_interval   interval in seconds for dns timeout maximum counter
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            --dns_max_ns_lookups     max names to look up with sender_ns_addrs
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            --dns_max_mx_lookups     max names to look up with sender_mx_addrs
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        -I, --instantcfg             re-reads rulefiles for every new request
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            --config_timeout <i>     parser timeout in seconds
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            --keep_rates             do not clear rate limit counters on reload
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            --save_rates <file>      save and load rate limits on disk
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            --fast_limit_evaluation  evaluate rate limits before ruleset is parsed
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                                     (please note the limitations)</pre>
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<pre>
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        Plugins:
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            --plugins <file>        loads postfwd plugins from file</pre>
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<pre>
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        Informational (use only at command-line!):
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        -C, --showconfig            shows ruleset summary, -v for verbose
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        -L, --stdoutlog             redirect syslog messages to stdout
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        -P, --perfmon               no syslogging, no stdout
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        -V, --version               shows program version
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        -h, --help                  shows usage
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        -m, --manual                shows program manual</pre>
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<p>
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</p>
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<hr />
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<h1><a name="description">DESCRIPTION</a></h1>
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<p>
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</p>
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<h2><a name="introduction">INTRODUCTION</a></h2>
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<p>postfwd is written to combine complex postfix restrictions in a ruleset similar to those of the most firewalls.
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The program uses the postfix policy delegation protocol to control access to the mail system before a message
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has been accepted (please visit <a href="http://www.postfix.org/SMTPD_POLICY_README.html">http://www.postfix.org/SMTPD_POLICY_README.html</a> for more information).</p>
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<p>postfwd allows you to choose an action (e.g. reject, dunno) for a combination of several smtp parameters
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(like sender and recipient address, size or the client's TLS fingerprint). Also it offers simple macros/acls
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which should allow straightforward and easy-to-read configurations.</p>
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<p><em>Features:</em></p>
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<p>* Complex combinations of smtp parameters</p>
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<p>* Combined RBL/RHSBL lookups with arbitrary actions depending on results</p>
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<p>* Scoring system</p>
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<p>* Date/time based rules</p>
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<p>* Macros/ACLs, Groups, Negation</p>
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<p>* Compare request attributes (e.g. client_name and helo_name)</p>
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<p>* Internal caching for requests and dns lookups</p>
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<p>* Built in statistics for rule efficiency analysis</p>
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<p>
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</p>
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<h2><a name="configuration">CONFIGURATION</a></h2>
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<p>A configuration line consists of optional item=value pairs, separated by semicolons
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(`;`) and the appropriate desired action:</p>
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<pre>
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        [ <item1>=<value>; <item2>=<value>; ... ] action=<result></pre>
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<p><em>Example:</em></p>
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<pre>
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        client_address=192.168.1.1 ; sender==no@bad.local ; action=REJECT</pre>
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<p>This will deny all mail from 192.168.1.1 with envelope sender <a href="mailto:no@bad.local.">no@bad.local.</a> The order of the elements
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is not important. So the following would lead to the same result as the previous example:</p>
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<pre>
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        action=REJECT ; client_address=192.168.1.1 ; sender==no@bad.local</pre>
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<p>The way how request items are compared to the ruleset can be influenced in the following way:</p>
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<pre>
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        ====================================================================
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         ITEM == VALUE                true if ITEM equals VALUE
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         ITEM => VALUE                true if ITEM >= VALUE
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         ITEM =< VALUE                true if ITEM <= VALUE
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         ITEM >  VALUE                true if ITEM >  VALUE
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         ITEM <  VALUE                true if ITEM <  VALUE
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         ITEM =~ VALUE                true if ITEM ~= /^VALUE$/i
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         ITEM != VALUE                false if ITEM equals VALUE
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         ITEM !> VALUE                false if ITEM >= VALUE
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         ITEM !< VALUE                false if ITEM <= VALUE
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         ITEM !~ VALUE                false if ITEM ~= /^VALUE$/i
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         ITEM =  VALUE                default behaviour (see ITEMS section)
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        ====================================================================</pre>
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<p>To identify single rules in your log files, you may add an unique identifier for each of it:</p>
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<pre>
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        id=R_001 ; action=REJECT ; client_address=192.168.1.1 ; sender==no@bad.local</pre>
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<p>You may use these identifiers as target for the `jump()` command (see ACTIONS section below). Leading
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or trailing whitespace characters will be ignored. Use '#' to comment your configuration. Others will
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appreciate.</p>
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<p>A ruleset consists of one or multiple rules, which can be loaded from files or passed as command line
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arguments. Please see the COMMAND LINE section below for more information on this topic.</p>
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<p>Since postfwd version 1.30 rules spanning span multiple lines can be defined by prefixing the following
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lines with one or multiple whitespace characters (or '}' for macros):</p>
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<pre>
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        id=RULE001
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                client_address=192.168.1.0/24
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                sender==no@bad.local
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                action=REJECT no access</pre>
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<p>postfwd versions prior to 1.30 require trailing ';' and '\'-characters:</p>
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<pre>
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        id=RULE001; \
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                client_address=192.168.1.0/24; \
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                sender==no@bad.local; \
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                action=REJECT no access</pre>
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<p>
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</p>
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<h2><a name="items">ITEMS</a></h2>
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<pre>
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        id                      - a unique rule id, which can be used for log analysis
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                                  ids also serve as targets for the "jump" command.</pre>
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<pre>
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        date, time              - a time or date range within the specified rule shall hit
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                                  # FORMAT:
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                                  # Feb, 29th
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                                  date=29.02.2008
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                                  # Dec, 24th - 26th
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                                  date=24.12.2008-26.12.2008
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                                  # from today until Nov, 23rd
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                                  date=-23.09.2008
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                                  # from April, 1st until today
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                                  date=01.04.2008-</pre>
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<pre>
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        days, months            - a range of weekdays (Sun-Sat) or months (Jan-Dec)
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                                  within the specified rule shall hit</pre>
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<pre>
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        score                   - when the specified score is hit (see ACTIONS section)
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                                  the specified action will be returned to postfix
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                                  scores are set global until redefined!</pre>
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<pre>
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        request_score           - this value allows to access a request's score. it
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                                  may be used as variable ($$request_score).</pre>
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<pre>
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        rbl, rhsbl,             - query the specified RBLs/RHSBLs, possible values are:
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        rhsbl_client,             <name>[/<reply>/<maxcache>, <name>/<reply>/<maxcache>]
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        rhsbl_sender,             (defaults: reply=^127\.0\.0\.\d+$ maxcache=3600)
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        rhsbl_reverse_client      the results of all rhsbl_* queries will be combined
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                                  in rhsbl_count (see below).</pre>
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<pre>
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        rblcount, rhsblcount    - minimum RBL/RHSBL hitcounts to match. if not specified
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                                  a single RBL/RHSBL hit will match the rbl/rhsbl items.
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                                  you may specify 'all' to evaluate all items, and use
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                                  it as variable in an action (see ACTIONS section)
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                                  (default: 1)</pre>
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<pre>
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        sender_localpart,       - the local-/domainpart of the sender address
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        sender_domain</pre>
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<pre>
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        recipient_localpart,    - the local-/domainpart of the recipient address
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        recipient_domain</pre>
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<pre>
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        helo_address            - postfwd tries to look up the helo_name. use
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                                  helo_address=!!(0.0.0.0/0) to check for unknown.
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                                  Please do not use this for positive access control
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                                  (whitelisting), as it might be forged.</pre>
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<pre>
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        sender_ns_names,        - postfwd tries to look up the names/ip addresses
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        sender_ns_addrs           of the nameservers for the sender domain part.
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                                  Please do not use this for positive access control
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                                  (whitelisting), as it might be forged.</pre>
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<pre>
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        sender_mx_names,        - postfwd tries to look up the names/ip addresses
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        sender_mx_addrs           of the mx records for the sender domain part.
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                                  Please do not use this for positive access control
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                                  (whitelisting), as it might be forged.</pre>
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<pre>
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        version                 - postfwd version, contains "postfwd n.nn"
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                                  this enables version based checks in your rulesets
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                                  (e.g. for migration). works with old versions too,
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                                  because a non-existing item always returns false:
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                                  # version >= 1.10
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                                  id=R01; version~=1\.[1-9][0-9]; sender_domain==some.org \
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                                        ; action=REJECT sorry no access</pre>
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<pre>
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        ratecount               - only available for rate(), size() and rcpt() actions.
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                                  contains the actual limit counter:
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                                        id=R01; action=rate(sender/200/600/REJECT limit of 200 exceeded [$$ratecount hits])
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                                        id=R02; action=rate(sender/100/600/WARN limit of 100 exceeded [$$ratecount hits])</pre>
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<p>Besides these you can specify any attribute of the postfix policy delegation protocol.  
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Feel free to combine them the way you need it (have a look at the EXAMPLES section below).</p>
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<p>Most values can be specified as regular expressions (PCRE). Please see the table below
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for details:</p>
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<pre>
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        # ==========================================================
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        # ITEM=VALUE                            TYPE
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        # ==========================================================
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        id=something                            mask = string
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        date=01.04.2007-22.04.2007              mask = date (DD.MM.YYYY-DD.MM.YYYY)
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        time=08:30:00-17:00:00                  mask = time (HH:MM:SS-HH:MM:SS)
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        days=Mon-Wed                            mask = weekdays (Mon-Wed) or numeric (1-3)
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        months=Feb-Apr                          mask = months (Feb-Apr) or numeric (1-3)
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        score=5.0                               mask = maximum floating point value
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        rbl=zen.spamhaus.org                    mask = <name>/<reply>/<maxcache>[,...]
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        rblcount=2                              mask = numeric, will match if rbl hits >= 2
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        helo_address=<a.b.c.d/nn>               mask = CIDR[,CIDR,...]
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        sender_ns_names=some.domain.tld         mask = PCRE
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        sender_mx_names=some.domain.tld         mask = PCRE
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        sender_ns_addrs=<a.b.c.d/nn>            mask = CIDR[,CIDR,...]
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        sender_mx_addrs=<a.b.c.d/nn>            mask = CIDR[,CIDR,...]
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        # ------------------------------
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        # Postfix version 2.1 and later:
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        # ------------------------------
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        client_address=<a.b.c.d/nn>             mask = CIDR[,CIDR,...]
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        client_name=another.domain.tld          mask = PCRE
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        reverse_client_name=another.domain.tld  mask = PCRE
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        helo_name=some.domain.tld               mask = PCRE
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        sender=foo@bar.tld                      mask = PCRE
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        recipient=bar@foo.tld                   mask = PCRE
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        recipient_count=5                       mask = numeric, will match if recipients >= 5
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        # ------------------------------
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        # Postfix version 2.2 and later:
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        # ------------------------------
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        sasl_method=plain                       mask = PCRE
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        sasl_username=you                       mask = PCRE
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        sasl_sender=                            mask = PCRE
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						||
        size=12345                              mask = numeric, will match if size >= 12345
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        ccert_subject=blackhole.nowhere.local   mask = PCRE (only if tls verified)
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        ccert_issuer=John+20Doe                 mask = PCRE (only if tls verified)
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        ccert_fingerprint=AA:BB:CC:DD:EE:...    mask = PCRE (do NOT use "..." here)
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        # ------------------------------
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        # Postfix version 2.3 and later:
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        # ------------------------------
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        encryption_protocol=TLSv1/SSLv3         mask = PCRE
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        encryption_cipher=DHE-RSA-AES256-SHA    mask = PCRE
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        encryption_keysize=256                  mask = numeric, will match if keysize >= 256
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        ...</pre>
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						||
<p>the current list can be found at <a href="http://www.postfix.org/SMTPD_POLICY_README.html">http://www.postfix.org/SMTPD_POLICY_README.html</a>. Please read carefully about which
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attribute can be used at which level of the smtp transaction (e.g. size will only work reliably at END-OF-MESSAGE level).
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Pattern matching is performed case insensitive.</p>
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<p>Multiple use of the same item is allowed and will compared as logical OR, which means that this will work as expected:</p>
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<pre>
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        id=TRUST001; action=OK; encryption_keysize=64
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                ccert_fingerprint=11:22:33:44:55:66:77:88:99
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                ccert_fingerprint=22:33:44:55:66:77:88:99:00
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                ccert_fingerprint=33:44:55:66:77:88:99:00:11
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                sender=@domain\.local$</pre>
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<p>client_address, rbl and rhsbl items may also be specified as whitespace-or-comma-separated values:</p>
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<pre>
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        id=SKIP01; action=dunno
 | 
						||
                client_address=192.168.1.0/24, 172.16.254.23
 | 
						||
        id=SKIP02; action=dunno
 | 
						||
                client_address=10.10.3.32 10.216.222.0/27</pre>
 | 
						||
<p>The following items currently have to be unique:</p>
 | 
						||
<pre>
 | 
						||
        id, minimum and maximum values, rblcount and rhsblcount</pre>
 | 
						||
<p>Any item can be negated by preceeding '!!' to it, e.g.:</p>
 | 
						||
<pre>
 | 
						||
        id=HOST001 ;  hostname == !!secure.trust.local ;  action=REJECT only secure.trust.local please</pre>
 | 
						||
<p>or using the right compare operator:</p>
 | 
						||
<pre>
 | 
						||
        id=HOST001 ;  hostname != secure.trust.local ;  action=REJECT only secure.trust.local please</pre>
 | 
						||
<p>To avoid confusion with regexps or simply for better visibility you can use '!!(...)':</p>
 | 
						||
<pre>
 | 
						||
        id=USER01 ;  sasl_username = !!( (bob|alice) )  ;  action=REJECT who is that?</pre>
 | 
						||
<p>Request attributes can be compared by preceeding '$$' characters, e.g.:</p>
 | 
						||
<pre>
 | 
						||
        id=R-003 ;  client_name = !! $$helo_name      ;  action=WARN helo does not match DNS
 | 
						||
        # or
 | 
						||
        id=R-003 ;  client_name = !!($$(helo_name))   ;  action=WARN helo does not match DNS</pre>
 | 
						||
<p>This is only valid for PCRE values (see list above). The comparison will be performed as case insensitive exact match.
 | 
						||
Use the '-vv' option to debug.</p>
 | 
						||
<p>These special items will be reset for any new rule:</p>
 | 
						||
<pre>
 | 
						||
        rblcount        - contains the number of RBL answers
 | 
						||
        rhsblcount      - contains the number of RHSBL answers
 | 
						||
        matches         - contains the number of matched items
 | 
						||
        dnsbltext       - contains the dns TXT part of all RBL and RHSBL replies in the form
 | 
						||
                          rbltype:rblname:<txt>; rbltype:rblname:<txt>; ...</pre>
 | 
						||
<p>These special items will be changed for any matching rule:</p>
 | 
						||
<pre>
 | 
						||
        request_hits    - contains ids of all matching rules</pre>
 | 
						||
<p>This means that it might be necessary to save them, if you plan to use these values in later rules:</p>
 | 
						||
<pre>
 | 
						||
        # set vals
 | 
						||
        id=RBL01 ; rhsblcount=all; rblcount=all
 | 
						||
                action=set(HIT_rhls=$$rhsblcount,HIT_rbls=$$rblcount,HIT_txt=$$dnsbltext)
 | 
						||
                rbl=list.dsbl.org, bl.spamcop.net, dnsbl.sorbs.net, zen.spamhaus.org
 | 
						||
                rhsbl_client=rddn.dnsbl.net.au, rhsbl.ahbl.org, rhsbl.sorbs.net
 | 
						||
                rhsbl_sender=rddn.dnsbl.net.au, rhsbl.ahbl.org, rhsbl.sorbs.net</pre>
 | 
						||
<pre>
 | 
						||
        # compare
 | 
						||
        id=RBL02 ; HIT_rhls>=1 ; HIT_rbls>=1 ; action=554 5.7.1 blocked using $$HIT_rhls RHSBLs and $$HIT_rbls RBLs [INFO: $$HIT_txt]
 | 
						||
        id=RBL03 ; HIT_rhls>=2               ; action=554 5.7.1 blocked using $$HIT_rhls RHSBLs [INFO: $$HIT_txt]
 | 
						||
        id=RBL04 ; HIT_rbls>=2               ; action=554 5.7.1 blocked using $$HIT_rbls RBLs [INFO: $$HIT_txt]</pre>
 | 
						||
<p>
 | 
						||
</p>
 | 
						||
<h2><a name="files">FILES</a></h2>
 | 
						||
<p>Since postfwd1 v1.15 and postfwd2 v0.18 long item lists can be stored in separate files:</p>
 | 
						||
<pre>
 | 
						||
        id=R001 ;  ccert_fingerprint==<a href="file:/etc/postfwd/wl_ccerts">file:/etc/postfwd/wl_ccerts</a> ;  action=DUNNO</pre>
 | 
						||
<p>postfwd will read a list of items (one item per line) from /etc/postfwd/wl_ccerts. comments are allowed:</p>
 | 
						||
<pre>
 | 
						||
        # client1
 | 
						||
        11:22:33:44:55:66:77:88:99
 | 
						||
        # client2
 | 
						||
        22:33:44:55:66:77:88:99:00
 | 
						||
        # client3
 | 
						||
        33:44:55:66:77:88:99:00:11</pre>
 | 
						||
<p>To use existing tables in key=value format, you can use:</p>
 | 
						||
<pre>
 | 
						||
        id=R001 ;  ccert_fingerprint==table:/etc/postfwd/wl_ccerts ;  action=DUNNO</pre>
 | 
						||
<p>This will ignore the right-hand value. Items can be mixed:</p>
 | 
						||
<pre>
 | 
						||
        id=R002 ;  action=REJECT
 | 
						||
                client_name==unknown
 | 
						||
                client_name==<a href="file:/etc/postfwd/blacklisted">file:/etc/postfwd/blacklisted</a></pre>
 | 
						||
<p>and for non pcre (comma separated) items:</p>
 | 
						||
<pre>
 | 
						||
        id=R003 ;  action=REJECT
 | 
						||
                client_address==10.1.1.1, <a href="file:/etc/postfwd/blacklisted">file:/etc/postfwd/blacklisted</a></pre>
 | 
						||
<pre>
 | 
						||
        id=R004 ;  action=REJECT
 | 
						||
                rbl=myrbl.home.local, zen.spamhaus.org, <a href="file:/etc/postfwd/rbls_changing">file:/etc/postfwd/rbls_changing</a></pre>
 | 
						||
<p>You can check your configuration with the --show_config option at the command line:</p>
 | 
						||
<pre>
 | 
						||
        # postfwd --showconfig --rule='action=DUNNO; client_address=10.1.0.0/16, <a href="file:/etc/postfwd/wl_clients">file:/etc/postfwd/wl_clients</a>, 192.168.2.1'</pre>
 | 
						||
<p>should give something like:</p>
 | 
						||
<pre>
 | 
						||
        Rule   0: id->"R-0"; action->"DUNNO"; client_address->"=;10.1.0.0/16, =;194.123.86.10, =;186.4.6.12, =;192.168.2.1"</pre>
 | 
						||
<p>If a file can not be read, it will be ignored:</p>
 | 
						||
<pre>
 | 
						||
        # postfwd --showconfig --rule='action=DUNNO; client_address=10.1.0.0/16, <a href="file:/etc/postfwd/wl_clients">file:/etc/postfwd/wl_clients</a>, 192.168.2.1'
 | 
						||
        [LOG warning]: error: file /etc/postfwd/wl_clients not found - file will be ignored ?
 | 
						||
        Rule   0: id->"R-0"; action->"DUNNO"; client_address->"=;10.1.0.0/16, =;192.168.2.1"</pre>
 | 
						||
<p>File items are evaluated at configuration stage. Therefore postfwd needs to be reloaded if a file has changed.</p>
 | 
						||
<p>If you want to specify a file, that will be reloaded for each request, you can use lfile: and ltable:</p>
 | 
						||
<pre>
 | 
						||
        id=R001; client_address=lfile:/etc/postfwd/client_whitelist; action=dunno</pre>
 | 
						||
<p>This will check the modification time of /etc/postfwd/client_whitelist every time the rule is evaluated and reload it as
 | 
						||
necessary. Of course this might increase the system load, so please use it with care.</p>
 | 
						||
<p>The --showconfig option illustrates the difference:</p>
 | 
						||
<pre>
 | 
						||
        ## evaluated at configuration stage
 | 
						||
        # postfwd2 --nodaemon -L --rule='client_address=table:/etc/postfwd/clients; action=dunno' -C
 | 
						||
        Rule   0: id->"R-0"; action->"dunno"; client_address->"=;1.1.1.1, =;1.1.1.2, =;1.1.1.3"</pre>
 | 
						||
<pre>
 | 
						||
        ## evaluated for any rulehit
 | 
						||
        # postfwd2 --nodaemon -L --rule='client_address=ltable:/etc/postfwd/clients; action=dunno' -C
 | 
						||
        Rule   0: id->"R-0"; action->"dunno"; client_address->"=;ltable:/etc/postfwd/clients"</pre>
 | 
						||
<p>Files can refer to other files. The following is valid.</p>
 | 
						||
<pre>
 | 
						||
        -- FILE /etc/postfwd/rules.cf --
 | 
						||
        id=R001; client_address=<a href="file:/etc/postfwd/clients_master.cf">file:/etc/postfwd/clients_master.cf</a>; action=DUNNO</pre>
 | 
						||
<pre>
 | 
						||
        -- FILE /etc/postfwd/clients_master.cf --
 | 
						||
        192.168.1.0/24
 | 
						||
        <a href="file:/etc/postfwd/clients_east.cf">file:/etc/postfwd/clients_east.cf</a>
 | 
						||
        <a href="file:/etc/postfwd/clients_west.cf">file:/etc/postfwd/clients_west.cf</a></pre>
 | 
						||
<pre>
 | 
						||
        -- FILE /etc/postfwd/clients_east.cf --
 | 
						||
        192.168.2.0/24</pre>
 | 
						||
<pre>
 | 
						||
        -- FILE /etc/postfwd/clients_west.cf --
 | 
						||
        192.168.3.0/24</pre>
 | 
						||
<p>Note that there is currently no loop detection (/a/file calls /a/file) and that this feature is only available
 | 
						||
with postfwd1 v1.15 and postfwd2 v0.18 and higher.</p>
 | 
						||
<p>
 | 
						||
</p>
 | 
						||
<h2><a name="actions">ACTIONS</a></h2>
 | 
						||
<p><em>General</em></p>
 | 
						||
<p>Actions will be executed, when all rule items have matched a request (or at least one of any item list). You can refer to
 | 
						||
request attributes by preceeding $$ characters, like:</p>
 | 
						||
<pre>
 | 
						||
        id=R-003; client_name = !!$$helo_name; action=WARN helo '$$helo_name' does not match DNS '$$client_name'
 | 
						||
        # or
 | 
						||
        id=R-003; client_name = !!$$helo_name; action=WARN helo '$$(helo_name)' does not match DNS '$$(client_name)'</pre>
 | 
						||
<p><em>postfix actions</em></p>
 | 
						||
<p>Actions will be replied to postfix as result to policy delegation requests. Any action that postfix understands is allowed - see
 | 
						||
"man 5 access" or <a href="http://www.postfix.org/access.5.html">http://www.postfix.org/access.5.html</a> for a description. If no action is specified, the postfix WARN action
 | 
						||
which simply logs the event will be used for the corresponding rule.</p>
 | 
						||
<p>postfwd will return dunno if it has reached the end of the ruleset and no rule has matched. This can be changed by placing a last
 | 
						||
rule containing only an action statement:</p>
 | 
						||
<pre>
 | 
						||
        ...
 | 
						||
        action=dunno ; sender=@domain.local     # sender is ok
 | 
						||
        action=reject                           # default deny</pre>
 | 
						||
<p><em>postfwd actions</em></p>
 | 
						||
<p>postfwd actions control the behaviour of the program. Currently you can specify the following:</p>
 | 
						||
<pre>
 | 
						||
        jump (<id>)
 | 
						||
        jumps to rule with id <id>, use this to skip certain rules.
 | 
						||
        you can jump backwards - but remember that there is no loop
 | 
						||
        detection at the moment! jumps to non-existing ids will be skipped.</pre>
 | 
						||
<pre>
 | 
						||
        score (<score>)
 | 
						||
        the request's score will be modified by the specified <score>,
 | 
						||
        which must be a floating point value. the modificator can be either
 | 
						||
                +n.nn   adds n.nn to current score
 | 
						||
                -n.nn   sustracts n.nn from the current score
 | 
						||
                *n.nn   multiplies the current score by n.nn
 | 
						||
                /n.nn   divides the current score through n.nn
 | 
						||
                =n.nn   sets the current score to n.nn
 | 
						||
        if the score exceeds the maximum set by `--scores` option (see
 | 
						||
        COMMAND LINE) or the score item (see ITEMS section), the action
 | 
						||
        defined for this case will be returned (default: 5.0=>"REJECT postfwd score exceeded").</pre>
 | 
						||
<pre>
 | 
						||
        set (<item>=<value>,<item>=<value>,...)
 | 
						||
        this command allows you to insert or override request attributes, which then may be
 | 
						||
        compared to your further ruleset. use this to speed up repeated comparisons to large item lists.
 | 
						||
        please see the EXAMPLES section for more information. you may separate multiple key=value pairs
 | 
						||
        by "," characters.</pre>
 | 
						||
<pre>
 | 
						||
        rate (<item>/<max>/<time>/<action>)
 | 
						||
        this command creates a counter for the given <item>, which will be increased any time a request
 | 
						||
        containing it arrives. if it exceeds <max> within <time> seconds it will return <action> to postfix.
 | 
						||
        rate counters are very fast as they are executed before the ruleset is parsed.
 | 
						||
        please note that <action> was limited to postfix actions (no postfwd actions) for postfwd versions <1.33!
 | 
						||
            # no more than 3 requests per 5 minutes
 | 
						||
            # from the same "unknown" client
 | 
						||
            id=RATE01 ;  client_name==unknown
 | 
						||
               action=rate(client_address/3/300/450 4.7.1 sorry, max 3 requests per 5 minutes)
 | 
						||
        Please note also that the order of rate limits in your ruleset is important, which means
 | 
						||
        that this:
 | 
						||
                # works as expected
 | 
						||
                id=R001; action=rcpt(sender/500/3600/REJECT limit of 500 recipients per hour for sender $$sender exceeded)
 | 
						||
                id=R002; action=rcpt(sender/200/3600/WARN state YELLOW for sender $$sender)
 | 
						||
        leads to different results than this:
 | 
						||
                # rule R002 never gets executed
 | 
						||
                id=R001; action=rcpt(sender/200/3600/WARN state YELLOW for sender $$sender)
 | 
						||
                id=R002; action=rcpt(sender/500/3600/REJECT limit of 500 recipients per hour for sender $$sender exceeded)</pre>
 | 
						||
<pre>
 | 
						||
        size (<item>/<max>/<time>/<action>)
 | 
						||
        this command works similar to the rate() command with the difference, that the rate counter is
 | 
						||
        increased by the request's size attribute. to do this reliably you should call postfwd from
 | 
						||
        smtpd_end_of_data_restrictions. if you want to be sure, you could check it within the ruleset:
 | 
						||
           # size limit 1.5mb per hour per client
 | 
						||
           id=SIZE01 ;  protocol_state==END-OF-MESSAGE ;  client_address!=10.1.1.1
 | 
						||
              action=size(client_address/1572864/3600/450 4.7.1 sorry, max 1.5mb per hour)</pre>
 | 
						||
<pre>
 | 
						||
        rcpt (<item>/<max>/<time>/<action>)
 | 
						||
        this command works similar to the rate() command with the difference, that the rate counter is
 | 
						||
        increased by the request's recipient_count attribute. to do this reliably you should call postfwd
 | 
						||
        from smtpd_data_restrictions or smtpd_end_of_data_restrictions. if you want to be sure, you could
 | 
						||
        check it within the ruleset:
 | 
						||
           # recipient count limit 3 per hour per client
 | 
						||
           id=RCPT01 ;  protocol_state==END-OF-MESSAGE ;  client_address!=10.1.1.1
 | 
						||
              action=rcpt(client_address/3/3600/450 4.7.1 sorry, max 3 recipients per hour)</pre>
 | 
						||
<pre>
 | 
						||
        rate5321,size5321,rcpt5321 (<item>/<max>/<time>/<action>)
 | 
						||
        same as the corresponding non-5321 functions, with the difference that the localpart of
 | 
						||
        sender oder recipient addresses are evaluated case-sensitive according to rfc5321. That
 | 
						||
        means that requests from bob@example.local and BoB@example.local will be treated differently</pre>
 | 
						||
<pre>
 | 
						||
        ask (<addr>:<port>[:<ignore>])
 | 
						||
        allows to delegate the policy decision to another policy service (e.g. postgrey). the first
 | 
						||
        and the second argument (address and port) are mandatory. a third optional argument may be
 | 
						||
        specified to tell postfwd to ignore certain answers and go on parsing the ruleset:
 | 
						||
           # example1: query postgrey and return it's answer to postfix
 | 
						||
           id=GREY; client_address==10.1.1.1; action=ask(127.0.0.1:10031)
 | 
						||
           # example2: query postgrey but ignore the answer, if it matches 'DUNNO'
 | 
						||
           # and continue parsing postfwd's ruleset
 | 
						||
           id=GREY; client_address==10.1.1.1; action=ask(127.0.0.1:10031:^dunno$)</pre>
 | 
						||
<pre>
 | 
						||
        mail(server/helo/from/to/subject/body)
 | 
						||
        This command is deprecated. You should try to use the sendmail() action instead.
 | 
						||
        Very basic mail command, that sends a message with the given arguments. LIMITATIONS:
 | 
						||
        This basically performs a telnet. No authentication or TLS are available. Additionally it does
 | 
						||
        not track notification state and will notify you any time, the corresponding rule hits.</pre>
 | 
						||
<pre>
 | 
						||
        sendmail(sendmail-path::from::to::subject::body)
 | 
						||
        Mail command, that uses an existing sendmail binary and sends a message with the given arguments.
 | 
						||
        LIMITATIONS: The command does not track notification state and will notify you any time, the
 | 
						||
        corresponding rule hits (which could mean 100 mails for a mail with 100 recipients at RCPT stage).</pre>
 | 
						||
<pre>
 | 
						||
        wait (<delay>)
 | 
						||
        pauses the program execution for <delay> seconds. use this for
 | 
						||
        delaying or throtteling connections.</pre>
 | 
						||
<pre>
 | 
						||
        note (<string>)
 | 
						||
        just logs the given string and continues parsing the ruleset.
 | 
						||
        if the string is empty, nothing will be logged (noop).</pre>
 | 
						||
<pre>
 | 
						||
        quit (<code>)
 | 
						||
        terminates the program with the given exit-code. postfix doesn`t
 | 
						||
        like that too much, so use it with care.</pre>
 | 
						||
<p>You can reference to request attributes, like</p>
 | 
						||
<pre>
 | 
						||
        id=R-HELO ;  helo_name=^[^\.]+$ ;  action=REJECT invalid helo '$$helo_name'</pre>
 | 
						||
<p>
 | 
						||
</p>
 | 
						||
<h2><a name="macros_acls">MACROS/ACLS</a></h2>
 | 
						||
<p>Multiple use of long items or combinations of them may be abbreviated by macros. Those must be prefixed by '&&' (two '&' characters).
 | 
						||
First the macros have to be defined as follows:</p>
 | 
						||
<pre>
 | 
						||
        &&RBLS { rbl=zen.spamhaus.org,list.dsbl.org,bl.spamcop.net,dnsbl.sorbs.net,ix.dnsbl.manitu.net; };</pre>
 | 
						||
<p>Then these may be used in your rules, like:</p>
 | 
						||
<pre>
 | 
						||
        &&RBLS ;  client_name=^unknown$                         ; action=REJECT
 | 
						||
        &&RBLS ;  client_name=(\d+[\.-_]){4}                    ; action=REJECT
 | 
						||
        &&RBLS ;  client_name=[\.-_](adsl|dynamic|ppp|)[\.-_]   ; action=REJECT</pre>
 | 
						||
<p>Macros can contain actions, too:</p>
 | 
						||
<pre>
 | 
						||
        # definition
 | 
						||
        &&GONOW { action=REJECT your request caused our spam detection policy to reject this message. More info at <a href="http://www.domain.local">http://www.domain.local</a>; };
 | 
						||
        # rules
 | 
						||
        &&GONOW ;  &&RBLS ;  client_name=^unknown$
 | 
						||
        &&GONOW ;  &&RBLS ;  client_name=(\d+[\.-_]){4}
 | 
						||
        &&GONOW ;  &&RBLS ;  client_name=[\.-_](adsl|dynamic|ppp|)[\.-_]</pre>
 | 
						||
<p>Macros can contain macros, too:</p>
 | 
						||
<pre>
 | 
						||
        # definition
 | 
						||
        &&RBLS{
 | 
						||
                rbl=zen.spamhaus.org
 | 
						||
                rbl=list.dsbl.org
 | 
						||
                rbl=bl.spamcop.net
 | 
						||
                rbl=dnsbl.sorbs.net
 | 
						||
                rbl=ix.dnsbl.manitu.net
 | 
						||
        };
 | 
						||
        &&DYNAMIC{
 | 
						||
                client_name=^unknown$
 | 
						||
                client_name=(\d+[\.-_]){4}
 | 
						||
                client_name=[\.-_](adsl|dynamic|ppp|)[\.-_]
 | 
						||
        };
 | 
						||
        &&GOAWAY { &&RBLS; &&DYNAMIC; };
 | 
						||
        # rules
 | 
						||
        &&GOAWAY ; action=REJECT dynamic client and listed on RBL</pre>
 | 
						||
<p>Basically macros are simple text substitutions - see the <a href="#parser">PARSER</a> section for more information.</p>
 | 
						||
<p>
 | 
						||
</p>
 | 
						||
<h2><a name="plugins">PLUGINS</a></h2>
 | 
						||
<p><strong>Description</strong></p>
 | 
						||
<p>The plugin interface allow you to define your own checks and enhance postfwd's
 | 
						||
functionality. Feel free to share useful things!</p>
 | 
						||
<p><strong>Warning</strong></p>
 | 
						||
<p>Note that the plugin interface is still at devel stage. Please test your plugins
 | 
						||
carefully, because errors may cause postfwd to break! It is also
 | 
						||
allowed to override attributes or built-in functions, but be sure that you know
 | 
						||
what you do because some of them are used internally.</p>
 | 
						||
<p>Please keep security in mind, when you access sensible ressources and never, ever
 | 
						||
run postfwd as privileged user! Also never trust your input (especially hostnames,
 | 
						||
and e-mail addresses).</p>
 | 
						||
<p><strong>ITEMS</strong></p>
 | 
						||
<p>Item plugins are perl subroutines which integrate additional attributes to requests
 | 
						||
before they are evaluated against postfwd's ruleset like any other item of the
 | 
						||
policy delegation protocol. This allows you to create your own checks.</p>
 | 
						||
<p>plugin-items can not be used selective. these functions will be executed for every
 | 
						||
request postfwd receives, so keep performance in mind.</p>
 | 
						||
<pre>
 | 
						||
        SYNOPSIS: %result = postfwd_items_plugin{<name>}(%request)</pre>
 | 
						||
<p>means that your subroutine, called <name>, has access to a hash called %request,
 | 
						||
which contains all request attributes, like $request{client_name} and must
 | 
						||
return a value in the following form:</p>
 | 
						||
<pre>
 | 
						||
        save: $result{<item>} = <value></pre>
 | 
						||
<p>this creates the new item <item> containing <value>, which will be integrated in
 | 
						||
the policy delegation request and therefore may be used in postfwd's ruleset.</p>
 | 
						||
<pre>
 | 
						||
        # do NOT remove the next line
 | 
						||
        %postfwd_items_plugin = (</pre>
 | 
						||
<pre>
 | 
						||
                # EXAMPLES - integrated in postfwd. no need to activate them here.
 | 
						||
                
 | 
						||
                        # allows to check postfwd version in ruleset
 | 
						||
                        "version" => sub {
 | 
						||
                                my(%request) = @_;
 | 
						||
                                my(%result) = (
 | 
						||
                                        "version" => $NAME." ".$VERSION,
 | 
						||
                                );
 | 
						||
                                return %result;
 | 
						||
                        },
 | 
						||
                
 | 
						||
                        # sender_domain and recipient_domain
 | 
						||
                        "address_parts" => sub {
 | 
						||
                                my(%request) = @_;
 | 
						||
                                my(%result) = ();
 | 
						||
                                $request{sender} =~ /@([^@]*)$/;
 | 
						||
                                $result{sender_domain} = ($1 || '');
 | 
						||
                                $request{recipient} =~ /@([^@]*)$/;
 | 
						||
                                $result{recipient_domain} = ($1 || '');
 | 
						||
                                return %result;
 | 
						||
                        },</pre>
 | 
						||
<pre>
 | 
						||
        # do NOT remove the next line
 | 
						||
        );</pre>
 | 
						||
<p><strong>COMPARE</strong></p>
 | 
						||
<p>Compare plugins allow you to define how your new items should be compared to the ruleset.
 | 
						||
These are optional. If you don't specify one, the default (== for exact match, =~ for PCRE, ...)
 | 
						||
will be used.</p>
 | 
						||
<pre>
 | 
						||
        SYNOPSIS:  <item> => sub { return &{$postfwd_compare{<type>}}(@_); },</pre>
 | 
						||
<pre>
 | 
						||
        # do NOT remove the next line
 | 
						||
        %postfwd_compare_plugin = (</pre>
 | 
						||
<pre>
 | 
						||
                EXAMPLES - integrated in postfwd. no need to activate them here.
 | 
						||
        
 | 
						||
                        # Simple example
 | 
						||
                        # SYNOPSIS:  <result> = <item> (return &{$postfwd_compare{<type>}}(@_))
 | 
						||
                        "client_address"  => sub { return &{$postfwd_compare{cidr}}(@_); },
 | 
						||
                        "size"            => sub { return &{$postfwd_compare{numeric}}(@_); },
 | 
						||
                        "recipient_count" => sub { return &{$postfwd_compare{numeric}}(@_); },
 | 
						||
        
 | 
						||
                        # Complex example
 | 
						||
                        # SYNOPSIS:  <result> = <item>(<operator>, <ruleset value>, <request value>, <request>)
 | 
						||
                        "numeric" => sub {
 | 
						||
                                my($cmp,$val,$myitem,%request) = @_;
 | 
						||
                                my($myresult) = undef;  $myitem ||= "0"; $val ||= "0";
 | 
						||
                                if ($cmp eq '==') {
 | 
						||
                                        $myresult = ($myitem == $val);
 | 
						||
                                } elsif ($cmp eq '=<') {
 | 
						||
                                        $myresult = ($myitem <= $val);
 | 
						||
                                } elsif ($cmp eq '=>') {
 | 
						||
                                        $myresult = ($myitem >= $val);
 | 
						||
                                } elsif ($cmp eq '<') {
 | 
						||
                                        $myresult = ($myitem < $val);
 | 
						||
                                } elsif ($cmp eq '>') {
 | 
						||
                                        $myresult = ($myitem > $val);
 | 
						||
                                } elsif ($cmp eq '!=') {
 | 
						||
                                        $myresult = not($myitem == $val);
 | 
						||
                                } elsif ($cmp eq '!<') {
 | 
						||
                                        $myresult = not($myitem <= $val);
 | 
						||
                                } elsif ($cmp eq '!>') {
 | 
						||
                                        $myresult = not($myitem >= $val);
 | 
						||
                                } else {
 | 
						||
                                        $myresult = ($myitem >= $val);
 | 
						||
                                };
 | 
						||
                                return $myresult;
 | 
						||
                        },</pre>
 | 
						||
<pre>
 | 
						||
        # do NOT remove the next line
 | 
						||
        );</pre>
 | 
						||
<p><strong>ACTIONS</strong></p>
 | 
						||
<p>Action plugins allow to define new postfwd actions. By setting the $stop-flag you can decide to
 | 
						||
continue or to stop parsing the ruleset.</p>
 | 
						||
<pre>
 | 
						||
        SYNOPSIS:  (<stop rule parsing>, <next rule index>, <return action>, <logprefix>, <request>) =
 | 
						||
                        <action> (<current rule index>, <current time>, <command name>, <argument>, <logprefix>, <request>)</pre>
 | 
						||
<pre>
 | 
						||
        # do NOT remove the next line
 | 
						||
        %postfwd_actions_plugin = (</pre>
 | 
						||
<pre>
 | 
						||
                # EXAMPLES - integrated in postfwd. no need to activate them here.
 | 
						||
        
 | 
						||
                        # note(<logstring>) command
 | 
						||
                        "note"  => sub {
 | 
						||
                                my($index,$now,$mycmd,$myarg,$myline,%request) = @_;
 | 
						||
                                my($myaction) = 'dunno'; my($stop) = 0;
 | 
						||
                                log_info "[RULES] ".$myline." - note: ".$myarg if $myarg;
 | 
						||
                                return ($stop,$index,$myaction,$myline,%request);
 | 
						||
                        },
 | 
						||
        
 | 
						||
                        # skips next <myarg> rules
 | 
						||
                        "skip" => sub {
 | 
						||
                                my($index,$now,$mycmd,$myarg,$myline,%request) = @_;
 | 
						||
                                my($myaction) = 'dunno'; my($stop) = 0;
 | 
						||
                                $index += $myarg if ( $myarg and not(($index + $myarg) > $#Rules) );
 | 
						||
                                return ($stop,$index,$myaction,$myline,%request);
 | 
						||
                        },
 | 
						||
        
 | 
						||
                        # dumps current request contents to syslog
 | 
						||
                        "dumprequest" => sub {
 | 
						||
                                my($index,$now,$mycmd,$myarg,$myline,%request) = @_;
 | 
						||
                                my($myaction) = 'dunno'; my($stop) = 0;
 | 
						||
                                map { log_info "[DUMP] rule=$index, Attribute: $_=$request{$_}" } (keys %request);
 | 
						||
                                return ($stop,$index,$myaction,$myline,%request);
 | 
						||
                        },</pre>
 | 
						||
<pre>
 | 
						||
        # do NOT remove the next line
 | 
						||
        );</pre>
 | 
						||
<p>
 | 
						||
</p>
 | 
						||
<h2><a name="command_line">COMMAND LINE</a></h2>
 | 
						||
<p><em>Ruleset</em></p>
 | 
						||
<p>The following arguments are used to specify the source of the postfwd ruleset. This means
 | 
						||
that at least one of the following is required for postfwd to work.</p>
 | 
						||
<pre>
 | 
						||
        -f, --file <file>
 | 
						||
        Reads rules from <file>. Please see the CONFIGURATION section
 | 
						||
        below for more information.</pre>
 | 
						||
<pre>
 | 
						||
        -r, --rule <rule>
 | 
						||
        Adds <rule> to ruleset. Remember that you might have to quote
 | 
						||
        strings that contain whitespaces or shell characters.</pre>
 | 
						||
<p><em>Scoring</em></p>
 | 
						||
<pre>
 | 
						||
        -s, --scores <val>=<action>
 | 
						||
        Returns <action> to postfix, when the request's score exceeds <val></pre>
 | 
						||
<p>Multiple usage is allowed. Just chain your arguments, like:</p>
 | 
						||
<pre>
 | 
						||
        postfwd -r "<item>=<value>;action=<result>" -f <file> -f <file> ...
 | 
						||
          or
 | 
						||
        postfwd --scores 4.5="WARN high score" --scores 5.0="REJECT postfwd score too high" ...</pre>
 | 
						||
<p>In case of multiple scores, the highest match will count. The order of the arguments will be
 | 
						||
reflected in the postfwd ruleset.</p>
 | 
						||
<p><em>Control</em></p>
 | 
						||
<pre>
 | 
						||
        -d, --daemon
 | 
						||
        postfwd will run as daemon and listen on the network for incoming
 | 
						||
        queries (default 127.0.0.1:10040).</pre>
 | 
						||
<pre>
 | 
						||
        -k, --kill
 | 
						||
        Stops a running postfwd daemon.</pre>
 | 
						||
<pre>
 | 
						||
        --reload
 | 
						||
        Reloads configuration.</pre>
 | 
						||
<pre>
 | 
						||
        --dumpstats
 | 
						||
        Displays program usage statistics.</pre>
 | 
						||
<pre>
 | 
						||
        --dumpcache
 | 
						||
        Displays cache contents.</pre>
 | 
						||
<pre>
 | 
						||
        --delcache <item>
 | 
						||
        Removes an item from the request cache. Use --dumpcache to identify objects.
 | 
						||
        E.g.:
 | 
						||
                # postfwd --dumpcache
 | 
						||
                ...
 | 
						||
                %rate_cache -> %sender=gmato@jqvo.org -> %RATE002+2_600 -> @count    -> '1'
 | 
						||
                %rate_cache -> %sender=gmato@jqvo.org -> %RATE002+2_600 -> @maxcount -> '2'
 | 
						||
                ...
 | 
						||
                # postfwd --delrate="sender=gmato@jqvo.org"
 | 
						||
                rate cache item 'sender=gmato@jqvo.org' removed</pre>
 | 
						||
<pre>
 | 
						||
        --delrate <item>
 | 
						||
        Removes an item from the rate cache. Use --dumpcache to identify objects.</pre>
 | 
						||
<p><em>Networking</em></p>
 | 
						||
<p>postfwd can be run as daemon so that it listens on the network for incoming requests.
 | 
						||
The following arguments will control it's behaviour in this case.</p>
 | 
						||
<pre>
 | 
						||
        -i, --interface <dev>
 | 
						||
        Bind postfwd to the specified interface (default 127.0.0.1).</pre>
 | 
						||
<pre>
 | 
						||
        -p, --port <port>
 | 
						||
        postfwd listens on the specified port (default tcp/10040).</pre>
 | 
						||
<pre>
 | 
						||
        --proto <type>
 | 
						||
        The protocol type for postfwd's socket. Currently you may use 'tcp' or 'unix' here.
 | 
						||
        To use postfwd with a unix domain socket, run it as follows:
 | 
						||
            postfwd --proto=unix --port=/somewhere/postfwd.socket</pre>
 | 
						||
<pre>
 | 
						||
        -u, --user <name>
 | 
						||
        Changes real and effective user to <name>.</pre>
 | 
						||
<pre>
 | 
						||
        -g, --group <name>
 | 
						||
        Changes real and effective group to <name>.</pre>
 | 
						||
<pre>
 | 
						||
        --umask <mask>
 | 
						||
        Changes the umask for filepermissions (unix domain sockets, pidfiles).
 | 
						||
        Attention: This is umask, not chmod - you have to specify the bits that
 | 
						||
        should NOT apply. E.g.: umask 077 equals to chmod 700.</pre>
 | 
						||
<pre>
 | 
						||
        -R, --chroot <path>
 | 
						||
        Chroot the process to the specified path.
 | 
						||
        Test this before using - you might need some libs there.</pre>
 | 
						||
<pre>
 | 
						||
        --pidfile <path>
 | 
						||
        The process id will be saved in the specified file.</pre>
 | 
						||
<pre>
 | 
						||
        --facility <f>
 | 
						||
        sets the syslog facility, default is 'mail'</pre>
 | 
						||
<pre>
 | 
						||
        --socktype <s>
 | 
						||
        sets the Sys::Syslog socktype to 'native', 'inet' or 'unix'.
 | 
						||
        Default is to auto-detect this depening on module version and os.</pre>
 | 
						||
<pre>
 | 
						||
        -l, --logname <label>
 | 
						||
        Labels the syslog messages. Useful when running multiple
 | 
						||
        instances of postfwd.</pre>
 | 
						||
<pre>
 | 
						||
        --loglen <int>
 | 
						||
        Truncates any syslog message after <int> characters.</pre>
 | 
						||
<p><em>Plugins</em></p>
 | 
						||
<pre>
 | 
						||
        --plugins <file>
 | 
						||
        Loads postfwd plugins from file. Please see <a href="http://postfwd.org/postfwd.plugins">http://postfwd.org/postfwd.plugins</a>
 | 
						||
        or the plugins.postfwd.sample that is available from the tarball for more info.</pre>
 | 
						||
<p><em>Optional arguments</em></p>
 | 
						||
<p>These parameters influence the way postfwd is working. Any of them can be combined.</p>
 | 
						||
<pre>
 | 
						||
        -v, --verbose
 | 
						||
        Verbose logging displays a lot of useful information but can cause
 | 
						||
        your logfiles to grow noticeably. So use it with caution. Set the option
 | 
						||
        twice (-vv) to get more information (logs all request attributes).</pre>
 | 
						||
<pre>
 | 
						||
        -c, --cache <int>    (default=600)
 | 
						||
        Timeout for request cache, results for identical requests will be
 | 
						||
        cached until config is reloaded or this time (in seconds) expired.
 | 
						||
        A setting of 0 disables this feature.</pre>
 | 
						||
<pre>
 | 
						||
        --cache-no-size
 | 
						||
        Ignores size attribute for cache comparisons which will lead to better
 | 
						||
        cache-hit rates. You should set this option, if you don't use the size
 | 
						||
        item in your ruleset.</pre>
 | 
						||
<pre>
 | 
						||
        --cache-no-sender
 | 
						||
        Ignores sender address for cache comparisons which will lead to better
 | 
						||
        cache-hit rates. You should set this option, if you don't use the sender
 | 
						||
        item in your ruleset.</pre>
 | 
						||
<pre>
 | 
						||
        --cache-rdomain-only 
 | 
						||
        This will strip the localpart of the recipient's address before filling the
 | 
						||
        cache. This may considerably increase cache-hit rates.</pre>
 | 
						||
<pre>
 | 
						||
        --cache-rbl-timeout <timeout>     (default=3600)
 | 
						||
        This default value will be used as timeout in seconds for rbl cache items,
 | 
						||
        if not specified in the ruleset.</pre>
 | 
						||
<pre>
 | 
						||
        --cache-rbl-default <pattern>    (default=^127\.0\.0\.\d+$)
 | 
						||
        Matches <pattern> to rbl/rhsbl answers (regexp) if not specified in the ruleset.</pre>
 | 
						||
<pre>
 | 
						||
        --cacheid <item>, <item>, ...
 | 
						||
        This csv-separated list of request attributes will be used to construct
 | 
						||
        the request cache identifier. Use this only, if you know exactly what you
 | 
						||
        are doing. If you, for example, use postfwd only for RBL/RHSBL control,
 | 
						||
        you may set this to
 | 
						||
                postfwd --cache=3600 --cacheid=client_name,client_address
 | 
						||
        This increases efficiency of caching and improves postfwd's performance.
 | 
						||
        Warning: You should list all items here, which are used in your ruleset!</pre>
 | 
						||
<pre>
 | 
						||
        --cleanup-requests <interval>    (default=600)
 | 
						||
        The request cache will be searched for timed out items after this <interval> in
 | 
						||
        seconds. It is a minimum value. The cleanup process will only take place, when
 | 
						||
        a new request arrives.</pre>
 | 
						||
<pre>
 | 
						||
        --cleanup-rbls <interval>    (default=600)
 | 
						||
        The rbl cache will be searched for timed out items after this <interval> in
 | 
						||
        seconds. It is a minimum value. The cleanup process will only take place, when
 | 
						||
        a new request arrives.</pre>
 | 
						||
<pre>
 | 
						||
        --cleanup-rates <interval>    (default=600)
 | 
						||
        The rate cache will be searched for timed out items after this <interval> in
 | 
						||
        seconds. It is a minimum value. The cleanup process will only take place, when
 | 
						||
        a new request arrives.</pre>
 | 
						||
<pre>
 | 
						||
        -S, --summary <int>    (default=600)
 | 
						||
        Shows some usage statistics (program uptime, request counter, matching rules)
 | 
						||
        every <int> seconds. This option is included by the -v switch.
 | 
						||
        This feature uses the alarm signal, so you can force postfwd to dump the stats
 | 
						||
        using `kill -ALRM <pid>` (where <pid> is the process id of postfwd).</pre>
 | 
						||
<pre>
 | 
						||
        Example:
 | 
						||
        Aug 19 12:39:45 mail1 postfwd[666]: [STATS] Counters: 213000 seconds uptime, 39 rules
 | 
						||
        Aug 19 12:39:45 mail1 postfwd[666]: [STATS] Requests: 71643 overall, 49 last interval, 62.88% cache hits
 | 
						||
        Aug 19 12:39:45 mail1 postfwd[666]: [STATS] Averages: 20.18 overall, 4.90 last interval, 557.30 top
 | 
						||
        Aug 19 12:39:45 mail1 postfwd[666]: [STATS] Contents: 44 cached requests, 239 cached dnsbl results
 | 
						||
        Aug 19 12:39:45 mail1 postfwd[666]: [STATS] Rule ID: R-001   matched: 2704 times
 | 
						||
        Aug 19 12:39:45 mail1 postfwd[666]: [STATS] Rule ID: R-002   matched: 9351 times
 | 
						||
        Aug 19 12:39:45 mail1 postfwd[666]: [STATS] Rule ID: R-003   matched: 3116 times
 | 
						||
        ...</pre>
 | 
						||
<pre>
 | 
						||
        --no-rulestats
 | 
						||
        Disables per rule statistics. Keeps your log clean, if you do not use them.
 | 
						||
        This option has no effect without --summary or --verbose set.</pre>
 | 
						||
<pre>
 | 
						||
        -L, --stdoutlog
 | 
						||
        Redirects all syslog messages to stdout for debugging. Never use this with postfix!</pre>
 | 
						||
<pre>
 | 
						||
        -t, --test
 | 
						||
        In test mode postfwd always returns "dunno", but logs according
 | 
						||
        to it`s ruleset. -v will be set automatically with this option.</pre>
 | 
						||
<pre>
 | 
						||
        -n, --nodns
 | 
						||
        Disables all DNS based checks like RBL checks. Rules containing
 | 
						||
        such elements will be ignored.</pre>
 | 
						||
<pre>
 | 
						||
        -n, --nodnslog
 | 
						||
        Disables logging of dns events.</pre>
 | 
						||
<pre>
 | 
						||
        --dns_timeout     (default: 14)
 | 
						||
        Sets the timeout for asynchonous dns queries in seconds. This value will apply to
 | 
						||
        all dns items in a rule.</pre>
 | 
						||
<pre>
 | 
						||
        --dns_timeout_max    (default: 10)
 | 
						||
        Sets the maximum timeout counter for dnsbl lookups. If the timeouts exceed this value
 | 
						||
        the corresponding dnsbl will be deactivated for a while (see --dns_timeout_interval).</pre>
 | 
						||
<pre>
 | 
						||
        --dns_timeout_interval    (default=1200)
 | 
						||
        The dnsbl timeout counter will be cleaned after this interval in seconds. Use this
 | 
						||
        in conjunction with the --dns_timeout_max parameter.</pre>
 | 
						||
<pre>
 | 
						||
        --dns_async_txt
 | 
						||
        Perform dnsbl A and TXT lookups simultaneously (otherwise only for listings with at
 | 
						||
        least one A record). This needs more network bandwidth due to increased queries but
 | 
						||
        might increase throughput because the lookups can be parallelized.</pre>
 | 
						||
<pre>
 | 
						||
        --dns_max_ns_lookups     (default=0)
 | 
						||
        maximum ns names to lookup up with sender_ns_addrs item. use 0 for no maximum.</pre>
 | 
						||
<pre>
 | 
						||
        --dns_max_mx_lookups     (default=0)
 | 
						||
        maximum mx names to lookup up with sender_mx_addrs item. use 0 for no maximum.</pre>
 | 
						||
<pre>
 | 
						||
        -I, --instantcfg
 | 
						||
        The config files, specified by -f will be re-read for every request
 | 
						||
        postfwd receives. This enables on-the-fly configuration changes
 | 
						||
        without restarting. Though files will be read only if necessary
 | 
						||
        (which means their access times changed since last read) this might
 | 
						||
        significantly increase system load.</pre>
 | 
						||
<pre>
 | 
						||
        --config_timeout    (default=3)
 | 
						||
        timeout in seconds to parse a single configuration line. if exceeded, the rule will
 | 
						||
        be skipped. this is used to prevent problems due to large files or loops.
 | 
						||
        
 | 
						||
        --keep_rates    (default=0)
 | 
						||
        With this option set postfwd does not clear the rate limit counters on reload. Please
 | 
						||
        note that you have to restart (not reload) postfwd with this option if you change
 | 
						||
        any rate limit rules.</pre>
 | 
						||
<pre>
 | 
						||
        --save_rates    (default=none)
 | 
						||
        With this option postfwd saves existing rate limit counters to disk and reloads them
 | 
						||
        on program start. This allows persistent rate limits across program restarts or reboots.
 | 
						||
        Please note that postfwd needs read and write access to the specified file.</pre>
 | 
						||
<pre>
 | 
						||
        --fast_limit_evaluation    (default=0)
 | 
						||
        Once a ratelimit was set by the ruleset, future requests will be evaluated against it
 | 
						||
        before consulting the ruleset. This mode was the default behaviour until v1.30.
 | 
						||
        With this mode rate limits will be faster, but also eventually set up
 | 
						||
        whitelisting-rules within the ruleset might not work as expected.
 | 
						||
        LIMITATIONS: This option does not allow nested postfwd commands like
 | 
						||
                action=rate(sender/3/60/wait(3))
 | 
						||
        This option doe not work with the strict-rfc5321 rate() functions.</pre>
 | 
						||
<p><em>Informational arguments</em></p>
 | 
						||
<p>These arguments are for command line usage only. Never ever use them with postfix spawn!</p>
 | 
						||
<pre>
 | 
						||
        -C, --showconfig
 | 
						||
        Displays the current ruleset. Use -v for verbose output.</pre>
 | 
						||
<pre>
 | 
						||
        -P, --perfmon
 | 
						||
        This option turns of any syslogging and output. It is included
 | 
						||
        for performance testing.</pre>
 | 
						||
<pre>
 | 
						||
        -V, --version
 | 
						||
        Displays the program version.</pre>
 | 
						||
<pre>
 | 
						||
        -h, --help
 | 
						||
        Shows program usage.</pre>
 | 
						||
<pre>
 | 
						||
        -m, --manual
 | 
						||
        Displays the program manual.</pre>
 | 
						||
<p>
 | 
						||
</p>
 | 
						||
<h2><a name="refresh">REFRESH</a></h2>
 | 
						||
<p>In daemon mode postfwd reloads it's ruleset after receiving a HUP signal. Please see the description of
 | 
						||
the '-I' switch to have your configuration refreshed for every request postfwd receives.</p>
 | 
						||
<p>
 | 
						||
</p>
 | 
						||
<h2><a name="examples">EXAMPLES</a></h2>
 | 
						||
<pre>
 | 
						||
        ## whitelisting
 | 
						||
        # 1. networks 192.168.1.0/24, 192.168.2.4
 | 
						||
        # 2. client_names *.gmx.net and *.gmx.de
 | 
						||
        # 3. sender *@someshop.tld from 11.22.33.44
 | 
						||
        id=WL001; action=dunno ; client_address=192.168.1.0/24, 192.168.2.4
 | 
						||
        id=WL002; action=dunno ; client_name=\.gmx\.(net|de)$
 | 
						||
        id=WL003; action=dunno ; sender=@someshop\.tld$ ; client_address=11.22.33.44</pre>
 | 
						||
<pre>
 | 
						||
        ## TLS control
 | 
						||
        # 1. *@authority.tld only with correct TLS fingerprint
 | 
						||
        # 2. *@secret.tld only with keysizes >=64
 | 
						||
        id=TL001; action=dunno                          ; sender=@authority\.tld$ ; ccert_fingerprint=AA:BB:CC..
 | 
						||
        id=TL002; action=REJECT wrong TLS fingerprint   ; sender=@authority\.tld$
 | 
						||
        id=TL003; action=REJECT tls keylength < 64      ; sender=@secret\.tld$ ; encryption_keysize=64</pre>
 | 
						||
<pre>
 | 
						||
        ## Combined RBL checks
 | 
						||
        # This will reject mail if
 | 
						||
        # 1. listed on ix.dnsbl.manitu.net
 | 
						||
        # 2. listed on zen.spamhaus.org (sbl and xbl, dns cache timeout 1200s instead of 3600s)
 | 
						||
        # 3. listed on min 2 of bl.spamcop.net, list.dsbl.org, dnsbl.sorbs.net
 | 
						||
        # 4. listed on bl.spamcop.net and one of rhsbl.ahbl.org, rhsbl.sorbs.net
 | 
						||
        id=RBL01 ; action=REJECT listed on ix.dnsbl.manitu.net  ; rbl=ix.dnsbl.manitu.net
 | 
						||
        id=RBL02 ; action=REJECT listed on zen.spamhaus.org     ; rbl=zen.spamhaus.org/127.0.0.[2-8]/1200
 | 
						||
        id=RBL03 ; action=REJECT listed on too many RBLs        ; rblcount=2 ; rbl=bl.spamcop.net, list.dsbl.org, dnsbl.sorbs.net
 | 
						||
        id=RBL04 ; action=REJECT combined RBL+RHSBL check       ; rbl=bl.spamcop.net ; rhsbl=rhsbl.ahbl.org, rhsbl.sorbs.net</pre>
 | 
						||
<pre>
 | 
						||
        ## Message size (requires message_size_limit to be set to 30000000)
 | 
						||
        # 1. 30MB for systems in *.customer1.tld
 | 
						||
        # 2. 20MB for SASL user joejob
 | 
						||
        # 3. 10MB default
 | 
						||
        id=SZ001; protocol_state==END-OF-MESSAGE; action=DUNNO; size<=30000000 ; client_name=\.customer1.tld$
 | 
						||
        id=SZ002; protocol_state==END-OF-MESSAGE; action=DUNNO; size<=20000000 ; sasl_username==joejob
 | 
						||
        id=SZ002; protocol_state==END-OF-MESSAGE; action=DUNNO; size<=10000000
 | 
						||
        id=SZ100; protocol_state==END-OF-MESSAGE; action=REJECT message too large</pre>
 | 
						||
<pre>
 | 
						||
        ## Selective Greylisting
 | 
						||
        ##
 | 
						||
        ## Note that postfwd does not include greylisting. This setup requires a running postgrey service
 | 
						||
        ## at port 10031 and the following postfix restriction class in your main.cf:
 | 
						||
        ##
 | 
						||
        ##      smtpd_restriction_classes = check_postgrey, ...
 | 
						||
        ##      check_postgrey = check_policy_service inet:127.0.0.1:10031
 | 
						||
        #
 | 
						||
        # 1. if listed on zen.spamhaus.org with results 127.0.0.10 or .11, dns cache timeout 1200s
 | 
						||
        # 2. Client has no rDNS
 | 
						||
        # 3. Client comes from several dialin domains
 | 
						||
        id=GR001; action=check_postgrey ; rbl=dul.dnsbl.sorbs.net, zen.spamhaus.org/127.0.0.1[01]/1200
 | 
						||
        id=GR002; action=check_postgrey ; client_name=^unknown$
 | 
						||
        id=GR003; action=check_postgrey ; client_name=\.(t-ipconnect|alicedsl|ish)\.de$</pre>
 | 
						||
<pre>
 | 
						||
        ## Date Time
 | 
						||
        date=24.12.2007-26.12.2007          ;  action=450 4.7.1 office closed during christmas
 | 
						||
        time=04:00:00-05:00:00              ;  action=450 4.7.1 maintenance ongoing, try again later
 | 
						||
        time=-07:00:00 ;  sasl_username=jim ;  action=450 4.7.1 to early for you, jim
 | 
						||
        time=22:00:00- ;  sasl_username=jim ;  action=450 4.7.1 to late now, jim
 | 
						||
        months=-Apr                         ;  action=450 4.7.1 see you in may
 | 
						||
        days=!!Mon-Fri                      ;  action=check_postgrey</pre>
 | 
						||
<pre>
 | 
						||
        ## Usage of jump
 | 
						||
        # The following allows a message size of 30MB for different
 | 
						||
        # users/clients while others will only have 10MB.
 | 
						||
        id=R001 ; action=jump(R100) ; sasl_username=^(Alice|Bob|Jane)$
 | 
						||
        id=R002 ; action=jump(R100) ; client_address=192.168.1.0/24
 | 
						||
        id=R003 ; action=jump(R100) ; ccert_fingerprint=AA:BB:CC:DD:...
 | 
						||
        id=R004 ; action=jump(R100) ; ccert_fingerprint=AF:BE:CD:DC:...
 | 
						||
        id=R005 ; action=jump(R100) ; ccert_fingerprint=DD:CC:BB:DD:...
 | 
						||
        id=R099 ; protocol_state==END-OF-MESSAGE; action=REJECT message too big (max. 10MB); size=10000000
 | 
						||
        id=R100 ; protocol_state==END-OF-MESSAGE; action=REJECT message too big (max. 30MB); size=30000000</pre>
 | 
						||
<pre>
 | 
						||
        ## Usage of score
 | 
						||
        # The following rejects a mail, if the client
 | 
						||
        # - is listed on 1 RBL and 1 RHSBL
 | 
						||
        # - is listed in 1 RBL or 1 RHSBL and has no correct rDNS
 | 
						||
        # - other clients without correct rDNS will be greylist-checked
 | 
						||
        # - some whitelists are used to lower the score
 | 
						||
        id=S01 ; score=2.6              ; action=check_postgrey
 | 
						||
        id=S02 ; score=5.0              ; action=REJECT postfwd score too high
 | 
						||
        id=R00 ; action=score(-1.0)     ; rbl=exemptions.ahbl.org,list.dnswl.org,query.bondedsender.org,spf.trusted-forwarder.org
 | 
						||
        id=R01 ; action=score(2.5)      ; rbl=bl.spamcop.net, list.dsbl.org, dnsbl.sorbs.net
 | 
						||
        id=R02 ; action=score(2.5)      ; rhsbl=rhsbl.ahbl.org, rhsbl.sorbs.net
 | 
						||
        id=N01 ; action=score(-0.2)     ; client_name==$$helo_name
 | 
						||
        id=N02 ; action=score(2.7)      ; client_name=^unknown$
 | 
						||
        ...</pre>
 | 
						||
<pre>
 | 
						||
        ## Usage of rate and size
 | 
						||
        # The following temporary rejects requests from "unknown" clients, if they
 | 
						||
        # 1. exceeded 30 requests per hour or
 | 
						||
        # 2. tried to send more than 1.5mb within 10 minutes
 | 
						||
        id=RATE01 ;  client_name==unknown ;  protocol_state==RCPT
 | 
						||
                action=rate(client_address/30/3600/450 4.7.1 sorry, max 30 requests per hour)
 | 
						||
        id=SIZE01 ;  client_name==unknown ;  protocol_state==END-OF-MESSAGE
 | 
						||
                action=size(client_address/1572864/600/450 4.7.1 sorry, max 1.5mb per 10 minutes)</pre>
 | 
						||
<pre>
 | 
						||
        ## Macros
 | 
						||
        # definition
 | 
						||
        &&RBLS { rbl=zen.spamhaus.org,list.dsbl.org,bl.spamcop.net,dnsbl.sorbs.net,ix.dnsbl.manitu.net; };
 | 
						||
        &&GONOW { action=REJECT your request caused our spam detection policy to reject this message. More info at <a href="http://www.domain.local">http://www.domain.local</a>; };
 | 
						||
        # rules
 | 
						||
        &&GONOW ;  &&RBLS ;  client_name=^unknown$
 | 
						||
        &&GONOW ;  &&RBLS ;  client_name=(\d+[\.-_]){4}
 | 
						||
        &&GONOW ;  &&RBLS ;  client_name=[\.-_](adsl|dynamic|ppp|)[\.-_]</pre>
 | 
						||
<pre>
 | 
						||
        ## Groups
 | 
						||
        # definition
 | 
						||
        &&RBLS{
 | 
						||
                rbl=zen.spamhaus.org
 | 
						||
                rbl=list.dsbl.org
 | 
						||
                rbl=bl.spamcop.net
 | 
						||
                rbl=dnsbl.sorbs.net
 | 
						||
                rbl=ix.dnsbl.manitu.net
 | 
						||
        };
 | 
						||
        &&RHSBLS{
 | 
						||
                ...
 | 
						||
        };
 | 
						||
        &&DYNAMIC{
 | 
						||
                client_name==unknown
 | 
						||
                client_name~=(\d+[\.-_]){4}
 | 
						||
                client_name~=[\.-_](adsl|dynamic|ppp|)[\.-_]
 | 
						||
                ...
 | 
						||
        };
 | 
						||
        &&BAD_HELO{
 | 
						||
                helo_name==my.name.tld
 | 
						||
                helo_name~=^([^\.]+)$
 | 
						||
                helo_name~=\.(local|lan)$
 | 
						||
                ...
 | 
						||
        };
 | 
						||
        &&MAINTENANCE{
 | 
						||
                date=15.01.2007
 | 
						||
                date=15.04.2007
 | 
						||
                date=15.07.2007
 | 
						||
                date=15.10.2007
 | 
						||
                time=03:00:00 - 04:00:00
 | 
						||
        };
 | 
						||
        # rules
 | 
						||
        id=COMBINED    ;  &&RBLS ;  &&DYNAMIC ;  action=REJECT dynamic client and listed on RBL
 | 
						||
        id=MAINTENANCE ;  &&MAINTENANCE       ;  action=DEFER maintenance time - please try again later
 | 
						||
        
 | 
						||
        # now with the set() command, note that long item
 | 
						||
        # lists don't have to be compared twice
 | 
						||
        id=RBL01    ;  &&RBLS      ;  action=set(HIT_rbls=1)
 | 
						||
        id=HELO01   ;  &&BAD_HELO  ;  action=set(HIT_helo=1)
 | 
						||
        id=DYNA01   ;  &&DYNAMIC   ;  action=set(HIT_dyna=1)
 | 
						||
        id=REJECT01 ;  HIT_rbls==1 ;  HIT_helo==1  ; action=REJECT please see <a href="http://some.org/info?reject=01">http://some.org/info?reject=01</a> for more info
 | 
						||
        id=REJECT02 ;  HIT_rbls==1 ;  HIT_dyna==1  ; action=REJECT please see <a href="http://some.org/info?reject=02">http://some.org/info?reject=02</a> for more info
 | 
						||
        id=REJECT03 ;  HIT_helo==1 ;  HIT_dyna==1  ; action=REJECT please see <a href="http://some.org/info?reject=03">http://some.org/info?reject=03</a> for more info</pre>
 | 
						||
<pre>
 | 
						||
        ## combined with enhanced rbl features
 | 
						||
        #
 | 
						||
        id=RBL01 ; rhsblcount=all ; rblcount=all ; &&RBLS ; &&RHSBLS
 | 
						||
             action=set(HIT_dnsbls=$$rhsblcount,HIT_dnsbls+=$$rblcount,HIT_dnstxt=$$dnsbltext)
 | 
						||
        id=RBL02 ; HIT_dnsbls>=2  ; action=554 5.7.1 blocked using $$HIT_dnsbls DNSBLs [INFO: $$HIT_dnstxt]</pre>
 | 
						||
<p>
 | 
						||
</p>
 | 
						||
<h2><a name="parser">PARSER</a></h2>
 | 
						||
<p><em>Configuration</em></p>
 | 
						||
<p>The postfwd ruleset can be specified at the commandline (-r option) or be read from files (-f). The order of your arguments will be kept. You should
 | 
						||
check the parser with the -C | --showconfig switch at the command line before applying a new config. The following call:</p>
 | 
						||
<pre>
 | 
						||
        postfwd --showconfig \
 | 
						||
                -r "id=TEST; recipient_count=100; action=WARN mail with 100+ recipients" \
 | 
						||
                -f /etc/postfwd.cf \
 | 
						||
                -r "id=DEFAULT; action=dunno";</pre>
 | 
						||
<p>will produce the following output:</p>
 | 
						||
<pre>
 | 
						||
        Rule   0: id->"TEST" action->"WARN mail with 100+ recipients"; recipient_count->"100"
 | 
						||
        ...
 | 
						||
        ... <content of /etc/postfwd.cf> ...
 | 
						||
        ...
 | 
						||
        Rule <n>: id->"DEFAULT" action->"dunno"</pre>
 | 
						||
<p>Multiple items of the same type will be added to lists (see the <a href="#items">ITEMS</a> section for more info):</p>
 | 
						||
<pre>
 | 
						||
        postfwd --showconfig \
 | 
						||
                -r "client_address=192.168.1.0/24; client_address=172.16.26.32; action=dunno"</pre>
 | 
						||
<p>will result in:</p>
 | 
						||
<pre>
 | 
						||
        Rule   0: id->"R-0"; action->"dunno"; client_address->"192.168.1.0/24, 172.16.26.32"</pre>
 | 
						||
<p>Macros are evaluated at configuration stage, which means that</p>
 | 
						||
<pre>
 | 
						||
        postfwd --showconfig \
 | 
						||
                -r "&&RBLS { rbl=bl.spamcop.net; client_name=^unknown$; };" \
 | 
						||
                -r "id=RBL001; &&RBLS; action=REJECT listed on spamcop and bad rdns";</pre>
 | 
						||
<p>will result in:</p>
 | 
						||
<pre>
 | 
						||
        Rule   0: id->"RBL001"; action->"REJECT listed on spamcop and bad rdns"; rbl->"bl.spamcop.net"; client_name->"^unknown$"</pre>
 | 
						||
<p><em>Request processing</em></p>
 | 
						||
<p>When a policy delegation request arrives it will be compared against postfwd`s ruleset. To inspect the processing in detail you should increase
 | 
						||
verbority using use the "-v" or "-vv" switch. "-L" redirects log messages to stdout.</p>
 | 
						||
<p>Keeping the order of the ruleset in general, items will be compared in random order, which basically means that</p>
 | 
						||
<pre>
 | 
						||
        id=R001; action=dunno; client_address=192.168.1.1; sender=bob@alice.local</pre>
 | 
						||
<p>equals to</p>
 | 
						||
<pre>
 | 
						||
        id=R001; sender=bob@alice.local; client_address=192.168.1.1; action=dunno</pre>
 | 
						||
<p>Lists will be evaluated in the specified order. This allows to place faster expressions at first:</p>
 | 
						||
<pre>
 | 
						||
        postfwd -vv -L -r "id=RBL001; rbl=localrbl.local zen.spamhaus.org; action=REJECT" /some/where/request.sample</pre>
 | 
						||
<p>produces the following</p>
 | 
						||
<pre>
 | 
						||
        [LOGS info]: compare rbl: "remotehost.remote.net[68.10.1.7]"  ->  "localrbl.local"
 | 
						||
        [LOGS info]: count1 rbl:  "2"  ->  "0"
 | 
						||
        [LOGS info]: query rbl:   localrbl.local 7.1.10.68 (7.1.10.68.localrbl.local)
 | 
						||
        [LOGS info]: count2 rbl:  "2"  ->  "0"
 | 
						||
        [LOGS info]: match rbl:   FALSE
 | 
						||
        [LOGS info]: compare rbl: "remotehost.remote.net[68.10.1.7]"  ->  "zen.spamhaus.org"
 | 
						||
        [LOGS info]: count1 rbl:  "2"  ->  "0"
 | 
						||
        [LOGS info]: query rbl:   zen.spamhaus.org 7.1.10.68 (7.1.10.68.zen.spamhaus.org)
 | 
						||
        [LOGS info]: count2 rbl:  "2"  ->  "0"
 | 
						||
        [LOGS info]: match rbl:   FALSE
 | 
						||
        [LOGS info]: Action: dunno</pre>
 | 
						||
<p>The negation operator !!(<value>) has the highest priority and therefore will be evaluated first. Then variable substitutions are performed:</p>
 | 
						||
<pre>
 | 
						||
        postfwd -vv -L -r "id=TEST; action=REJECT; client_name=!!($$heloname)" /some/where/request.sample</pre>
 | 
						||
<p>will give</p>
 | 
						||
<pre>
 | 
						||
        [LOGS info]: compare client_name:     "unknown"  ->  "!!($$helo_name)"
 | 
						||
        [LOGS info]: negate client_name:      "unknown"  ->  "$$helo_name"
 | 
						||
        [LOGS info]: substitute client_name:  "unknown"  ->  "english-breakfast.cloud8.net"
 | 
						||
        [LOGS info]: match client_name:  TRUE
 | 
						||
        [LOGS info]: Action: REJECT</pre>
 | 
						||
<p><em>Ruleset evaluation</em></p>
 | 
						||
<p>A rule hits when all items (or at least one element of a list for each item) have matched. As soon as one item (or all elements of a list) fails
 | 
						||
to compare against the request attribute the parser will jump to the next rule in the postfwd ruleset.</p>
 | 
						||
<p>If a rule matches, there are two options:</p>
 | 
						||
<p>* Rule returns postfix action (dunno, reject, ...)
 | 
						||
The parser stops rule processing and returns the action to postfix. Other rules will not be evaluated.</p>
 | 
						||
<p>* Rule returns postfwd action (jump(), <code>note()</code>, ...)
 | 
						||
The parser evaluates the given action and continues with the next rule (except for the <code>jump()</code> or <code>quit()</code> actions - please see the <a href="#actions">ACTIONS</a> section
 | 
						||
for more information). Nothing will be sent to postfix.</p>
 | 
						||
<p>If no rule has matched and the end of the ruleset is reached postfwd will return dunno without logging anything unless in verbose mode. You may
 | 
						||
simply place a last `catch-all´ rule to change that behaviour:</p>
 | 
						||
<pre>
 | 
						||
        ... <your rules> ...
 | 
						||
        id=DEFAULT ;  action=dunno</pre>
 | 
						||
<p>will log any request that passes the ruleset without having hit a prior rule.</p>
 | 
						||
<p>
 | 
						||
</p>
 | 
						||
<h2><a name="integration">INTEGRATION</a></h2>
 | 
						||
<p><em>Integration via daemon mode</em></p>
 | 
						||
<p>The common way to use postfwd is to start it as daemon, listening at a specified tcp port.
 | 
						||
As postfwd will run in a single instance (multiplexing mode), it will take most benefit of
 | 
						||
it`s internal caching in that case. Start postfwd with the following parameters:</p>
 | 
						||
<pre>
 | 
						||
        postfwd -d -f /etc/postfwd.cf -i 127.0.0.1 -p 10040 -u nobody -g nobody -S</pre>
 | 
						||
<p>For efficient caching you should check if you can use the options --cache-rdomain-only, --cache-no-sender
 | 
						||
and --cache-no-size.</p>
 | 
						||
<p>Now check your syslogs (default facility "mail") for a line like:</p>
 | 
						||
<pre>
 | 
						||
        Aug  9 23:00:24 mail postfwd[5158]: postfwd n.nn ready for input</pre>
 | 
						||
<p>and use `netstat -an|grep 10040` to check for something like</p>
 | 
						||
<pre>
 | 
						||
        tcp  0  0  127.0.0.1:10040  0.0.0.0:*  LISTEN</pre>
 | 
						||
<p>If everything works, open your postfix main.cf and insert the following</p>
 | 
						||
<pre>
 | 
						||
        127.0.0.1:10040_time_limit      = 3600                                          <--- integration
 | 
						||
        smtpd_recipient_restrictions    = permit_mynetworks                             <--- recommended
 | 
						||
                                          reject_unauth_destination                     <--- recommended
 | 
						||
                                          check_policy_service inet:127.0.0.1:10040     <--- integration</pre>
 | 
						||
<p>Reload your configuration with `postfix reload` and watch your logs. In it works you should see
 | 
						||
lines like the following in your mail log:</p>
 | 
						||
<pre>
 | 
						||
        Aug  9 23:01:24 mail postfwd[5158]: rule=22, id=ML_POSTFIX, client=english-breakfast.cloud9.net[168.100.1.7], sender=owner-postfix-users@postfix.tld, recipient=someone@domain.local, helo=english-breakfast.cloud9.net, proto=ESMTP, state=RCPT, action=dunno</pre>
 | 
						||
<p>If you want to check for size or rcpt_count items you must integrate postfwd in smtp_data_restrictions or
 | 
						||
smtpd_end_of_data_restrictions. Of course you can also specify a restriction class and use it in your access
 | 
						||
tables. First create a file /etc/postfix/policy containing:</p>
 | 
						||
<pre>
 | 
						||
        domain1.local           postfwdcheck
 | 
						||
        domain2.local           postfwdcheck
 | 
						||
        ...</pre>
 | 
						||
<p>Then postmap that file (`postmap hash:/etc/postfix/policy`), open your main.cf and enter</p>
 | 
						||
<pre>
 | 
						||
        # Restriction Classes
 | 
						||
        smtpd_restriction_classes       = postfwdcheck, <some more>...                          <--- integration
 | 
						||
        postfwdcheck                    = check_policy_service inet:127.0.0.1:10040             <--- integration</pre>
 | 
						||
<pre>
 | 
						||
        127.0.0.1:10040_time_limit      = 3600                                                  <--- integration
 | 
						||
        smtpd_recipient_restrictions    = permit_mynetworks,                                    <--- recommended
 | 
						||
                                          reject_unauth_destination,                            <--- recommended
 | 
						||
                                          ...                                                   <--- optional
 | 
						||
                                          check_recipient_access hash:/etc/postfix/policy,      <--- integration
 | 
						||
                                          ...                                                   <--- optional</pre>
 | 
						||
<p>Reload postfix and watch your logs.</p>
 | 
						||
<p><em>Integration via xinetd</em></p>
 | 
						||
<p>There might be several reasons for you to use postfwd via a tcp wrapper package like xinetd (see <a href="http://www.xinetd.org/">http://www.xinetd.org/</a>).
 | 
						||
I won`t discuss that here. If you plan to do so, just add the following line to your /etc/services file:</p>
 | 
						||
<pre>
 | 
						||
        # postfwd port
 | 
						||
        postfwd     10040/tcp</pre>
 | 
						||
<p>Then create a file '/etc/xinetd.d/postfwd':</p>
 | 
						||
<pre>
 | 
						||
        {
 | 
						||
                interface       = 127.0.0.1
 | 
						||
                socket_type     = stream
 | 
						||
                protocol        = tcp
 | 
						||
                wait            = no
 | 
						||
                user            = nobody
 | 
						||
                server          = /usr/local/bin/postfwd
 | 
						||
                server_args     = -f /etc/postfwd.cf
 | 
						||
                disable         = no
 | 
						||
        }</pre>
 | 
						||
<p>and restart the xinetd daemon (usually a SIGHUP should be fine). If you experience problems
 | 
						||
you might want to check your system's log for xinetd errors like "socket already in use".</p>
 | 
						||
<p>The integration with postfix is similar to the <em>Integration via daemon mode</em> section above.
 | 
						||
Reload postfix and watch your logs to see if everything works.</p>
 | 
						||
<p>
 | 
						||
</p>
 | 
						||
<h2><a name="testing">TESTING</a></h2>
 | 
						||
<p>First you have to create a ruleset (see Configuration section). Check it with</p>
 | 
						||
<pre>
 | 
						||
        postfwd -f /etc/postfwd.cf -C</pre>
 | 
						||
<p>There is an example policy request distributed with postfwd, called 'request.sample'.
 | 
						||
Simply change it to meet your requirements and use</p>
 | 
						||
<pre>
 | 
						||
        postfwd -f /etc/postfwd.cf <request.sample</pre>
 | 
						||
<p>You should get an answer like</p>
 | 
						||
<pre>
 | 
						||
        action=<whateveryouconfigured></pre>
 | 
						||
<p>For network tests I use netcat:</p>
 | 
						||
<pre>
 | 
						||
        nc 127.0.0.1 10040 <request.sample</pre>
 | 
						||
<p>to send a request to postfwd. If you receive nothing, make sure that postfwd is running and
 | 
						||
listening on the specified network settings.</p>
 | 
						||
<p>
 | 
						||
</p>
 | 
						||
<h2><a name="performance">PERFORMANCE</a></h2>
 | 
						||
<p>Some of these proposals might not match your environment. Please check your requirements and test new options carefully!</p>
 | 
						||
<pre>
 | 
						||
        - use caching options
 | 
						||
        - use the correct match operator ==, <=, >=
 | 
						||
        - use ^ and/or $ in regular expressions
 | 
						||
        - use item lists (faster than single rules)
 | 
						||
        - use set() action on repeated item lists
 | 
						||
        - use jumps and rate limits
 | 
						||
        - use a pre-lookup rule for rbl/rhsbls with empty note() action</pre>
 | 
						||
<p>
 | 
						||
</p>
 | 
						||
<h2><a name="see_also">SEE ALSO</a></h2>
 | 
						||
<p>See <a href="http://www.postfix.org/SMTPD_POLICY_README.html">http://www.postfix.org/SMTPD_POLICY_README.html</a> for a description
 | 
						||
of how Postfix policy servers work.</p>
 | 
						||
<p>
 | 
						||
</p>
 | 
						||
<hr />
 | 
						||
<h1><a name="license">LICENSE</a></h1>
 | 
						||
<p>postfwd is free software and released under BSD license, which basically means
 | 
						||
that you can do what you want as long as you keep the copyright notice:</p>
 | 
						||
<p>Copyright (c) 2007, Jan Peter Kessler
 | 
						||
All rights reserved.</p>
 | 
						||
<p>Redistribution and use in source and binary forms, with or without modification,
 | 
						||
are permitted provided that the following conditions are met:</p>
 | 
						||
<pre>
 | 
						||
 * Redistributions of source code must retain the above copyright
 | 
						||
   notice, this list of conditions and the following disclaimer.
 | 
						||
 * Redistributions in binary form must reproduce the above copyright
 | 
						||
   notice, this list of conditions and the following disclaimer in
 | 
						||
   the documentation and/or other materials provided with the
 | 
						||
   distribution.
 | 
						||
 * Neither the name of the authors nor the names of his contributors
 | 
						||
   may be used to endorse or promote products derived from this
 | 
						||
   software without specific prior written permission.</pre>
 | 
						||
<p>THIS SOFTWARE IS PROVIDED BY ME ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 | 
						||
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 | 
						||
FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BE LIABLE FOR ANY DIRECT,
 | 
						||
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 | 
						||
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 | 
						||
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 | 
						||
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 | 
						||
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 | 
						||
POSSIBILITY OF SUCH DAMAGE.</p>
 | 
						||
<p>
 | 
						||
</p>
 | 
						||
<hr />
 | 
						||
<h1><a name="author">AUTHOR</a></h1>
 | 
						||
<p>Jan Peter Kessler <info (AT) postfwd (DOT) org>. Let me know, if you have any suggestions.</p>
 | 
						||
 | 
						||
</body>
 | 
						||
 | 
						||
</html>
 |