forked from extern/shorewall_code
119 lines
8.7 KiB
HTML
119 lines
8.7 KiB
HTML
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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<html>
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<head>
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<meta http-equiv="Content-Language" content="en-us">
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<meta http-equiv="Content-Type"
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content="text/html; charset=windows-1252">
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<meta name="GENERATOR" content="Microsoft FrontPage 5.0">
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<meta name="ProgId" content="FrontPage.Editor.Document">
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<title>Shorewall Accounting</title>
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<meta name="author" content="Tom Eastep">
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</head>
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<body>
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<h1 style="text-align: center;">Shorewall and Traffic Accounting<br>
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</h1>
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Shorewall Traffic Accounting support was added in Shorewall release
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1.4.7.<br>
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<br>
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Shorewall accounting rules are described in the file
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/etc/shorewall/accounting. By default, the accounting rules are placed
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in a chain called "accounting" and can thus be displayed using
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"shorewall show accounting". All traffic passing into, out of or
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through the firewall traverses the accounting chain including traffic
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that will later be rejected by <a href="Documentation.htm#Interfaces">interface
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options</a> such as "tcpflags" and "maclist". If your kernel doesn't
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support the connection tracking match extension (Kernel 2.4.21) then
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some traffic rejected under 'norfc1918' will not traverse the
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accounting chain.<br>
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<br>
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The columns in the accounting file are as follows:<br>
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<ul>
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<li><span style="font-weight: bold;">ACTION</span> - What to do when
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a
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match is found. Possible values are:</li>
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<ul>
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<li>COUNT- Simply count the match and continue trying to
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match the
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packet with the following accounting rules</li>
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<li>DONE- Count the match and don't attempt to match any following
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accounting rules.</li>
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<li><<span style="font-style: italic;">chain</span>> - The
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name of a chain to jump to. Shorewall will create the chain
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automatically. If the name of the chain is followed by ":COUNT" then a
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COUNT rule matching this rule will automatically be added to <<span
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style="font-style: italic;">chain</span>>. Chain names must start
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with a letter, must be composed of letters and digits, and may contain
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underscores ("_") and periods ("."). Beginning with Shorewall version
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1.4.8, chain names man also contain embedded dashes ("-") and are not
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required to start with a letter.<br>
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</li>
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</ul>
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<li><span style="font-weight: bold;">CHAIN </span>- The name of the
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chain where the accounting rule is to be added. If empty or "-" then
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the
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"accounting" chain is assumed.<br>
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</li>
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<li><span style="font-weight: bold;">SOURCE</span> - Packet Source.
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The name of an interface, an address (host or net) or an interface name
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followed by ":" and a host or net address.</li>
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<li><span style="font-weight: bold;">DESTINATION</span> - Packet
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Destination Format the same as the SOURCE column.</li>
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<li><span style="font-weight: bold;">PROTOCOL</span> - A protocol
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name
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(from /etc/protocols) or a protocol number.</li>
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<li><span style="font-weight: bold;">DEST PORT</span> - Destination
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Port number. Service name from /etc/services or port number. May only
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be
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specified if the protocol is TCP or UDP (6 or 17).</li>
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<li><span style="font-weight: bold;">SOURCE PORT</span>- Source Port
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number. Service name from /etc/services or port number. May only be
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specified if the protocol is TCP or UDP (6 or 17).<br>
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</li>
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</ul>
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In all columns except ACTION and CHAIN, the values "-","any" and "all"
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are treated as wild-cards.<br>
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<br>
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The accounting rules are evaluated in the Netfilter 'filter' table.
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This is the same environment where the 'rules' file rules are evaluated
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and in this environment, DNAT has already occurred in inbound packets
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and SNAT has not yet occurred on outbound ones.<br>
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<br>
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Accounting rules are not stateful -- each rule only handles traffic in
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one direction. For example, if eth0 is your internet interface and you
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have a web server in your DMZ connected to eth1 then to count HTTP
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traffic in both directions requires two rules: <br>
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<pre> #ACTION CHAIN SOURCE DESTINATION PROTOCOL DEST SOURCE<br> # PORT PORT<br> DONE - eth0 eth1 tcp 80<br> DONE - eth1 eth0 tcp - 80</pre>
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Associating a counter with a chain allows for nice reporting. For
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example:<br>
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<pre> #ACTION CHAIN SOURCE DESTINATION PROTOCOL DEST SOURCE<br> # PORT PORT<br> web:COUNT - eth0 eth1 tcp 80<br> web:COUNT - eth1 eth0 tcp - 80<br> web:COUNT - eth0 eth1 tcp 443<br> web:COUNT - eth1 eth0 tcp - 443<br> DONE web<br></pre>
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Now "shorewall show web" will give you a breakdown of your web traffic:<br>
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<div style="margin-left: 40px;">
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<pre>[root@gateway shorewall]# shorewall show web<br>Shorewall-1.4.6-20030821 Chain web at gateway.shorewall.net - Wed Aug 20 09:48:56 PDT 2003<br> <br>Counters reset Wed Aug 20 09:48:00 PDT 2003<br> <br>Chain web (4 references)<br> pkts bytes target prot opt in out source destination<br> 11 1335 tcp -- eth0 eth1 0.0.0.0/0 0.0.0.0/0 tcp dpt:80<br> 18 1962 tcp -- eth1 eth0 0.0.0.0/0 0.0.0.0/0 tcp spt:80<br> 0 0 tcp -- eth0 eth1 0.0.0.0/0 0.0.0.0/0 tcp dpt:443<br> 0 0 tcp -- eth1 eth0 0.0.0.0/0 0.0.0.0/0 tcp spt:443<br> 29 3297 RETURN all -- * * 0.0.0.0/0 0.0.0.0/0<br>[root@gateway shorewall]#</pre>
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</div>
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Here's a slightly different example:<br>
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<pre> #ACTION CHAIN SOURCE DESTINATION PROTOCOL DEST SOURCE<br> # PORT PORT<br> web - eth0 eth1 tcp 80<br> web - eth1 eth0 tcp - 80<br> web - eth0 eth1 tcp 443<br> web - eth1 eth0 tcp - 443<br><br> COUNT web eth0 eth1<br> COUNT web eth1 eth0<br></pre>
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Now "shorewall show web" simply gives you a breakdown by input and
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output:<br>
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<br>
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<pre style="margin-left: 40px;">[root@gateway shorewall]# shorewall show accounting web <br>Shorewall-1.4.6-20030821 Chains accounting web at gateway.shorewall.net - Wed Aug 20 10:27:21 PDT 2003<br> <br>Counters reset Wed Aug 20 10:24:33 PDT 2003<br> <br>Chain accounting (3 references)<br> pkts bytes target prot opt in out source destination<br> 8767 727K web tcp -- eth0 eth1 0.0.0.0/0 0.0.0.0/0 tcp dpt:80<br> 0 0 web tcp -- eth0 eth1 0.0.0.0/0 0.0.0.0/0 tcp dpt:443<br>11506 13M web tcp -- eth1 eth0 0.0.0.0/0 0.0.0.0/0 tcp spt:80<br> 0 0 web tcp -- eth1 eth0 0.0.0.0/0 0.0.0.0/0 tcp spt:443<br>Chain web (4 references)<br> pkts bytes target prot opt in out source destination<br> 8767 727K all -- eth0 eth1 0.0.0.0/0 0.0.0.0/0<br>11506 13M all -- eth1 eth0 0.0.0.0/0 0.0.0.0/0<br>[root@gateway shorewall]#<br></pre>
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Here's how the same example would be constructed on an HTTP server
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(READ THAT FOLKS -- IT SAYS <span style="text-decoration: underline;"><span
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style="font-weight: bold;">SERVER</span></span>. If you want to
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account for web browsing, you have to reverse the rules below) with
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only
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one interface (eth0):<br>
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<pre style="margin-left: 40px;">#ACTION CHAIN SOURCE DESTINATION PROTOCOL DEST SOURCE<br># PORT PORT<br>web - eth0 - tcp 80<br>web - - eth0 tcp - 80<br>web - eth0 - tcp 443<br>web - - eth0 tcp - 443<br><br>COUNT web eth0 -<br>COUNT web - eth0<br></pre>
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Note that with only one interface, only the SOURCE (for input rules) or
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the DESTINATION (for output rules) is specified in each rule.<br>
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<br>
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Here's the output:<br>
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<pre style="margin-left: 40px;">[root@mail shorewall]# shorewall show accounting web <br>Shorewall-1.4.7 Chains accounting web at mail.shorewall.net - Sun Oct 12 10:27:21 PDT 2003<br> <br>Counters reset Sat Oct 11 08:12:57 PDT 2003<br> <br>Chain accounting (3 references)<br> pkts bytes target prot opt in out source destination<br> 8767 727K web tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:80<br> 0 0 web tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:443<br>11506 13M web tcp -- * eth0 0.0.0.0/0 0.0.0.0/0 tcp spt:80<br> 0 0 web tcp -- * eth0 0.0.0.0/0 0.0.0.0/0 tcp spt:443<br>Chain web (4 references)<br> pkts bytes target prot opt in out source destination<br> 8767 727K all -- eth0 * 0.0.0.0/0 0.0.0.0/0<br>11506 13M all -- * eth0 0.0.0.0/0 0.0.0.0/0<br>[root@mail shorewall]#<br></pre>
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<p align="left"><font size="2">Last updated 12/06/2003 - <a
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href="support.htm">Tom Eastep</a></font></p>
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<p><font face="Trebuchet MS"><a href="copyright.htm"><font size="2">Copyright</font>
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<EFBFBD> <font size="2">2003 Thomas M. Eastep.</font></a></font></p>
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<br>
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<br>
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</body>
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</html>
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