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<p class="MsoNormal">Hello,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am trying to monitor multiple files using Linux audit. In order to get better performance, I am trying to reduce number of rules.
<o:p></o:p></p>
<p class="MsoNormal">If I specify more than one path field as in below example I am getting “Invalid argument”.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Examle1:<o:p></o:p></p>
<p class="MsoNormal"># auditctl -a always,exit -F arch=x86_64 -F path=/home/secpack/test.c -F path=/home/secpack/test -S open<o:p></o:p></p>
<p class="MsoNormal">Error sending add rule data request (Invalid argument)<o:p></o:p></p>
<p class="MsoNormal"># auditctl -a always,exit -F arch=x86_64 -F path=/home/secpack/test.c -F dir=/tmp/ -S open<o:p></o:p></p>
<p class="MsoNormal">Error sending add rule data request (Invalid argument)<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">However, I am able to create a single rule to monitor multiple PIDs or UIDs as below.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Examle2:<o:p></o:p></p>
<p class="MsoNormal"># auditctl -a always,exit -F arch=x86_64 -F pid=3526 -F pid=3537<o:p></o:p></p>
<p class="MsoNormal"># auditctl -a always,exit -F arch=x86_64 -F auid=0 -F auid=512 -F auid=1002<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">As per the auditctl man page, Build a rule field takes up to 64 fields on a single command line. Each one must start with -F. Each field equation is anded with each other to trigger an audit record.
<o:p></o:p></p>
<p class="MsoNormal">My question is, <o:p></o:p></p>
<p class="MsoNormal">1. specify more than one path field as in example1 is valid?
<o:p></o:p></p>
<p class="MsoNormal">2. If not valid than how do I create single audit rule to monitor multiple files/directory?<o:p></o:p></p>
<p class="MsoNormal">3. If valid, then why “Invalid argument” is reported?<o:p></o:p></p>
<p class="MsoNormal">4. To monitor 10 files, should 10 audit rules required?<o:p></o:p></p>
<p class="MsoNormal">5. if 10 rules are required, how to I optimize the rule for performance?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">My next question is does Linux audit support regular expressions? How do I create audit rule to monitor /var/log/*.log?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"># auditctl -a always,exit -F arch=x86_64 -F path=^/var/log/*.log$ -S open<o:p></o:p></p>
<p class="MsoNormal">Error sending add rule data request (Invalid argument)<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">If my questions are already documented, please guide me to the documentation.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Regards,<o:p></o:p></p>
<p class="MsoNormal">Ketan<o:p></o:p></p>
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