1<?xml version="1.0" encoding="ISO-8859-1"?> 2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 3<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!-- 4 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 5 This file is generated from xml source: DO NOT EDIT 6 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX 7 --> 8<title>mod_log_forensic - Apache HTTP Server</title> 9<link href="/style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" /> 10<link href="/style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" /> 11<link href="/style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" /><link rel="stylesheet" type="text/css" href="/style/css/prettify.css" /> 12<script src="/style/scripts/prettify.min.js" type="text/javascript"> 13</script> 14 15<link href="/images/favicon.ico" rel="shortcut icon" /></head> 16<body> 17<div id="page-header"> 18<p class="menu"><a href="/mod/">Modules</a> | <a href="/mod/directives.html">Directives</a> | <a href="http://wiki.apache.org/httpd/FAQ">FAQ</a> | <a href="/glossary.html">Glossary</a> | <a href="/sitemap.html">Sitemap</a></p> 19<p class="apache">Apache HTTP Server Version 2.4</p> 20<img alt="" src="/images/feather.gif" /></div> 21<div class="up"><a href="./"><img title="<-" alt="<-" src="/images/left.gif" /></a></div> 22<div id="path"> 23<a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.4</a> > <a href="./">Modules</a></div> 24<div id="page-content"> 25<div id="preamble"><h1>Apache Module mod_log_forensic</h1> 26<div class="toplang"> 27<p><span>Available Languages: </span><a href="/en/mod/mod_log_forensic.html" title="English"> en </a> | 28<a href="/fr/mod/mod_log_forensic.html" hreflang="fr" rel="alternate" title="Fran�ais"> fr </a> | 29<a href="/ja/mod/mod_log_forensic.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> | 30<a href="/tr/mod/mod_log_forensic.html" hreflang="tr" rel="alternate" title="T�rk�e"> tr </a></p> 31</div> 32<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Forensic Logging of the requests made to the server</td></tr> 33<tr><th><a href="module-dict.html#Status">Status:</a></th><td>Extension</td></tr> 34<tr><th><a href="module-dict.html#ModuleIdentifier">Module�Identifier:</a></th><td>log_forensic_module</td></tr> 35<tr><th><a href="module-dict.html#SourceFile">Source�File:</a></th><td>mod_log_forensic.c</td></tr> 36<tr><th><a href="module-dict.html#Compatibility">Compatibility:</a></th><td><code class="module"><a href="/mod/mod_unique_id.html">mod_unique_id</a></code> is no longer required since 37version 2.1</td></tr></table> 38<h3>Summary</h3> 39 40 <p>This module provides for forensic logging of client 41 requests. Logging is done before and after processing a request, so the 42 forensic log contains two log lines for each request. 43 The forensic logger is very strict, which means:</p> 44 45 <ul> 46 <li>The format is fixed. You cannot modify the logging format at 47 runtime.</li> 48 <li>If it cannot write its data, the child process 49 exits immediately and may dump core (depending on your 50 <code class="directive"><a href="/mod/mpm_common.html#coredumpdirectory">CoreDumpDirectory</a></code> 51 configuration).</li> 52 </ul> 53 54 <p>The <code>check_forensic</code> script, which can be found in the 55 distribution's support directory, may be helpful in evaluating the 56 forensic log output.</p> 57</div> 58<div id="quickview"><h3 class="directives">Directives</h3> 59<ul id="toc"> 60<li><img alt="" src="/images/down.gif" /> <a href="#forensiclog">ForensicLog</a></li> 61</ul> 62<h3>Topics</h3> 63<ul id="topics"> 64<li><img alt="" src="/images/down.gif" /> <a href="#formats">Forensic Log Format</a></li> 65<li><img alt="" src="/images/down.gif" /> <a href="#security">Security Considerations</a></li> 66</ul><h3>See also</h3> 67<ul class="seealso"> 68<li><a href="/logs.html">Apache Log Files</a></li> 69<li><code class="module"><a href="/mod/mod_log_config.html">mod_log_config</a></code></li> 70</ul><ul class="seealso"><li><a href="#comments_section">Comments</a></li></ul></div> 71<div class="top"><a href="#page-header"><img alt="top" src="/images/up.gif" /></a></div> 72<div class="section"> 73<h2><a name="formats" id="formats">Forensic Log Format</a></h2> 74 <p>Each request is logged two times. The first time is <em>before</em> it's 75 processed further (that is, after receiving the headers). The second log 76 entry is written <em>after</em> the request processing at the same time 77 where normal logging occurs.</p> 78 79 <p>In order to identify each request, a unique request ID is assigned. 80 This forensic ID can be cross logged in the normal transfer log using the 81 <code>%{forensic-id}n</code> format string. If you're using 82 <code class="module"><a href="/mod/mod_unique_id.html">mod_unique_id</a></code>, its generated ID will be used.</p> 83 84 <p>The first line logs the forensic ID, the request line and all received 85 headers, separated by pipe characters (<code>|</code>). A sample line 86 looks like the following (all on one line):</p> 87 88 <div class="example"><p><code> 89 +yQtJf8CoAB4AAFNXBIEAAAAA|GET /manual/de/images/down.gif 90 HTTP/1.1|Host:localhost%3a8080|User-Agent:Mozilla/5.0 (X11; 91 U; Linux i686; en-US; rv%3a1.6) Gecko/20040216 92 Firefox/0.8|Accept:image/png, <var>etc...</var> 93 </code></p></div> 94 95 <p>The plus character at the beginning indicates that this is the first log 96 line of this request. The second line just contains a minus character and 97 the ID again:</p> 98 99 <div class="example"><p><code> 100 -yQtJf8CoAB4AAFNXBIEAAAAA 101 </code></p></div> 102 103 <p>The <code>check_forensic</code> script takes as its argument the name 104 of the logfile. It looks for those <code>+</code>/<code>-</code> ID pairs 105 and complains if a request was not completed.</p> 106</div><div class="top"><a href="#page-header"><img alt="top" src="/images/up.gif" /></a></div> 107<div class="section"> 108<h2><a name="security" id="security">Security Considerations</a></h2> 109 <p>See the <a href="/misc/security_tips.html#serverroot">security tips</a> 110 document for details on why your security could be compromised 111 if the directory where logfiles are stored is writable by 112 anyone other than the user that starts the server.</p> 113 <p>The log files may contain sensitive data such as the contents of 114 <code>Authorization:</code> headers (which can contain passwords), so 115 they should not be readable by anyone except the user that starts the 116 server.</p> 117</div> 118<div class="top"><a href="#page-header"><img alt="top" src="/images/up.gif" /></a></div> 119<div class="directive-section"><h2><a name="ForensicLog" id="ForensicLog">ForensicLog</a> <a name="forensiclog" id="forensiclog">Directive</a></h2> 120<table class="directive"> 121<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Sets filename of the forensic log</td></tr> 122<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ForensicLog <var>filename</var>|<var>pipe</var></code></td></tr> 123<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr> 124<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr> 125<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_log_forensic</td></tr> 126</table> 127 <p>The <code class="directive">ForensicLog</code> directive is used to 128 log requests to the server for forensic analysis. Each log entry 129 is assigned a unique ID which can be associated with the request 130 using the normal <code class="directive"><a href="/mod/mod_log_config.html#customlog">CustomLog</a></code> 131 directive. <code class="module"><a href="/mod/mod_log_forensic.html">mod_log_forensic</a></code> creates a token called 132 <code>forensic-id</code>, which can be added to the transfer log 133 using the <code>%{forensic-id}n</code> format string.</p> 134 135 <p>The argument, which specifies the location to which 136 the logs will be written, can take one of the following two 137 types of values:</p> 138 139 <dl> 140 <dt><var>filename</var></dt> 141 <dd>A filename, relative to the <code class="directive"><a href="/mod/core.html#serverroot">ServerRoot</a></code>.</dd> 142 143 <dt><var>pipe</var></dt> 144 <dd>The pipe character "<code>|</code>", followed by the path 145 to a program to receive the log information on its standard 146 input. The program name can be specified relative to the <code class="directive"><a href="/mod/core.html#serverroot">ServerRoot</a></code> directive. 147 148 <div class="warning"><h3>Security:</h3> 149 <p>If a program is used, then it will be run as the user who 150 started <code class="program"><a href="/programs/httpd.html">httpd</a></code>. This will be root if the server was 151 started by root; be sure that the program is secure or switches to a 152 less privileged user.</p> 153 </div> 154 155 <div class="note"><h3>Note</h3> 156 <p>When entering a file path on non-Unix platforms, care should be taken 157 to make sure that only forward slashes are used even though the platform 158 may allow the use of back slashes. In general it is a good idea to always 159 use forward slashes throughout the configuration files.</p> 160 </div></dd> 161 </dl> 162 163</div> 164</div> 165<div class="bottomlang"> 166<p><span>Available Languages: </span><a href="/en/mod/mod_log_forensic.html" title="English"> en </a> | 167<a href="/fr/mod/mod_log_forensic.html" hreflang="fr" rel="alternate" title="Fran�ais"> fr </a> | 168<a href="/ja/mod/mod_log_forensic.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a> | 169<a href="/tr/mod/mod_log_forensic.html" hreflang="tr" rel="alternate" title="T�rk�e"> tr </a></p> 170</div><div class="top"><a href="#page-header"><img src="/images/up.gif" alt="top" /></a></div><div class="section"><h2><a id="comments_section" name="comments_section">Comments</a></h2><div class="warning"><strong>Notice:</strong><br />This is not a Q&A section. 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