+<?xml version='1.0' encoding='ISO-8859-1'?>
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
+
+<!--
+
+Process this file with an XSLT processor: `xsltproc \
+-''-nonet /usr/share/sgml/docbook/stylesheet/xsl/nwalsh/\
+manpages/docbook.xsl manpage.dbk'. A manual page
+<package>.<section> will be generated. You may view the
+manual page with: nroff -man <package>.<section> | less'. A
+typical entry in a Makefile or Makefile.am is:
+
+DB2MAN=/usr/share/sgml/docbook/stylesheet/xsl/nwalsh/\
+manpages/docbook.xsl
+XP=xsltproc -''-nonet
+
+manpage.1: manpage.dbk
+ $(XP) $(DB2MAN) $<
+
+The xsltproc binary is found in the xsltproc package. The
+XSL files are in docbook-xsl. Please remember that if you
+create the nroff version in one of the debian/rules file
+targets (such as build), you will need to include xsltproc
+and docbook-xsl in your Build-Depends control field.
+
+-->
+
+ <!-- Fill in your name for FIRSTNAME and SURNAME. -->
+ <!ENTITY dhfirstname "<firstname>martin f.</firstname>">
+ <!ENTITY dhsurname "<surname>krafft</surname>">
+ <!-- Please adjust the date whenever revising the manpage. -->
+ <!ENTITY dhdate "<date>Apr 19, 2008</date>">
+ <!-- SECTION should be 1-8, maybe w/ subsection other parameters are
+ allowed: see man(7), man(1). -->
+ <!ENTITY dhsection "<manvolnum>8</manvolnum>">
+ <!ENTITY dhemail "<email>madduck@madduck.net</email>">
+ <!ENTITY dhusername "martin f. krafft">
+ <!ENTITY dhucpackage "<refentrytitle>molly-guard</refentrytitle>">
+ <!ENTITY dhpackage "molly-guard">
+ <!ENTITY dhcommand "<command>molly-guard</command>">
+
+ <!ENTITY debian "<productname>Debian</productname>">
+ <!ENTITY gnu "<acronym>GNU</acronym>">
+ <!ENTITY gpl "&gnu; <acronym>GPL</acronym>">
+]>
+
+<refentry>
+ <refentryinfo>
+ <address>
+ &dhemail;
+ </address>
+ <copyright>
+ <year>2008</year>
+ <holder>&dhusername;</holder>
+ </copyright>
+ &dhdate;
+ </refentryinfo>
+ <refmeta>
+ &dhucpackage;
+
+ &dhsection;
+ </refmeta>
+ <refnamediv>
+ <refname>&dhcommand;</refname>
+
+ <refpurpose>guard against accidental shutdowns/reboots</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <cmdsynopsis>
+ <command>shutdown</command>
+ <arg choice="opt">
+ -<option>hV</option>
+ </arg>
+ <arg choice="opt">
+ <option>--molly-guard-do-nothing</option>
+ </arg>
+ <arg choice="opt">
+ -- <replaceable>script_options</replaceable>
+ </arg>
+ </cmdsynopsis>
+ <cmdsynopsis>
+ <command>halt</command>
+ <arg choice="opt">
+ -<option>hV</option>
+ </arg>
+ <arg choice="opt">
+ <option>--molly-guard-do-nothing</option>
+ </arg>
+ <arg choice="opt">
+ -- <replaceable>script_options</replaceable>
+ </arg>
+ </cmdsynopsis>
+ <cmdsynopsis>
+ <command>reboot</command>
+ <arg choice="opt">
+ -<option>hV</option>
+ </arg>
+ <arg choice="opt">
+ <option>--molly-guard-do-nothing</option>
+ </arg>
+ <arg choice="opt">
+ -- <replaceable>script_options</replaceable>
+ </arg>
+ </cmdsynopsis>
+ <cmdsynopsis>
+ <command>poweroff</command>
+ <arg choice="opt">
+ -<option>hV</option>
+ </arg>
+ <arg choice="opt">
+ <option>--molly-guard-do-nothing</option>
+ </arg>
+ <arg choice="opt">
+ -- <replaceable>script_options</replaceable>
+ </arg>
+ </cmdsynopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>DESCRIPTION</title>
+
+ <para> &dhcommand; attempts to prevent you from accidentally shutting down
+ or rebooting machines. It does this by injecting a couple of checks
+ before the existing commands: <command>halt</command>,
+ <command>reboot</command>, <command>shutdown</command>, and
+ <command>poweroff</command>. This happens via scripts with the same
+ names in <filename>/usr/sbin</filename>, so it only works if you have
+ <filename>/usr/sbin</filename> before <filename>/sbin</filename> in your
+ <envar>PATH</envar>!</para>
+
+ <para> Before &dhcommand; invokes the real command, all scripts in
+ <filename>/etc/molly-guard/run.d/</filename> have to run and exit
+ successfully; else, it aborts the command.
+ <command>run-parts(1)</command> is used to process the directory.</para>
+
+ <para> &dhcommand; passes any <replaceable>script_options</replaceable> to the
+ scripts, and also populates the environment with the following
+ variables:</para>
+
+ <itemizedlist>
+ <listitem><para><envar>MOLLYGUARD_CMD</envar> - the actual command
+ invoked by the user.</para></listitem>
+
+ <listitem><para><envar>MOLLYGUARD_DO_NOTHING</envar> - set to
+ <option>1</option> if this is a demo-run.</para></listitem>
+
+ <listitem><para><envar>MOLLYGUARD_SETTINGS</envar> - the path to
+ a shell script snippet which scripts can source to obtain
+ settings.</para></listitem>
+ </itemizedlist>
+
+ <para> &dhcommand; prints the contents of
+ <filename>/etc/molly-guard/messages.d/COMMAND</filename> or
+ <filename>/etc/molly-guard/messages.d/default</filename> to the console,
+ if either exists. This is due to
+ <filename>/etc/molly-guard/run.d/10-print-message</filename>.</para>
+
+ </refsect1>
+ <refsect1>
+ <title>GUARDING SSH SESSIONS</title>
+
+ <para> &dhcommand; was primarily designed to shield SSH connections. This
+ functionality (which should arguably be provided by the
+ <package>openssh-server</package> package) is implemented in
+ <filename>/etc/molly-guard/run.d/10-print-message</filename>.</para>
+
+ <para> This script first tests whether the command is being executed from
+ a <filename>tty</filename> which has been created by
+ <command>sshd</command>. It also checks whether the variable
+ <envar>SSH_CONNECTION</envar> is defined. If any of these tests are
+ successful, test script queries the user for the machine's hostname,
+ which should be sufficient to prevent the user from doing something by
+ accident.</para>
+
+ <para> You can pass the <option>--pretend-ssh</option> script option to
+ &dhcommand; to pretend that those tests succeeds. Alternatively, setting
+ <envar>ALWAYS_QUERY_HOSTNAME</envar> in
+ <filename>/etc/default/molly-guard</filename> causes the script to
+ always query.</para>
+
+ <para> The following situations are still UNGUARDED. If you can think of
+ ways to protect against those, please let me know!</para>
+
+ <itemizedlist>
+ <listitem><para>running <application>sudo</application> within
+ <application>screen</application> or <application>screen</application> within
+ <application>sudo</application>; <application>sudo</application> eats the
+ <envar>SSH_CONNECTION</envar> variable, and
+ <application>screen</application> creates a new
+ <filename>pty</filename>.</para></listitem>
+ <listitem><para>executing those command in a remote terminal window,
+ that is a <application>XTerm</application> started on a remote
+ machine but displaying on the local <application>X</application>
+ server.</para></listitem>
+ </itemizedlist>
+
+ <para> You have been warned. You can use the
+ <option>--molly-guard-do-nothing</option> switch to prevent anything
+ from happening, e.g. <userinput>halt
+ --molly-guard-do-nothing</userinput>. </para>
+ </refsect1>
+
+ <refsect1>
+ <title>OPTIONS</title>
+ <variablelist>
+ <varlistentry>
+ <term>--molly-guard-do-nothing</term>
+ <listitem>
+ <para>
+ Cause &dhcommand; to print the command which would be executed,
+ after processing all scripts, instead of executing it.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>-h</term>
+ <term>--help</term>
+ <listitem>
+ <para>
+ Display usage information.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>-V</term>
+ <term>--version</term>
+ <listitem>
+ <para>
+ Display version information.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>SEE ALSO</title>
+ <para>
+ <citerefentry>
+ <refentrytitle>shutdown</refentrytitle>
+ <manvolnum>8</manvolnum>
+ </citerefentry>,
+ <citerefentry>
+ <refentrytitle>halt</refentrytitle>
+ <manvolnum>1</manvolnum>
+ </citerefentry>,
+ <citerefentry>
+ <refentrytitle>reboot</refentrytitle>
+ <manvolnum>8</manvolnum>
+ </citerefentry>,
+ <citerefentry>
+ <refentrytitle>poweroff</refentrytitle>
+ <manvolnum>8</manvolnum>
+ </citerefentry>.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>LEGALESE</title>
+
+ <para>
+ &dhpackage; is copyright by &dhusername;. Andrew Ruthven came up with
+ the idea of using the scripts directory and submitted a patch, which
+ I modified a bit.
+ </para>
+
+ <para>
+ This manual page was written by &dhusername; &dhemail;.
+ </para>
+
+ <para>
+ Permission is granted to copy, distribute and/or modify this document
+ under the terms of the Artistic License 2.0
+ </para>
+
+ </refsect1>
+</refentry>
projects / code / molly-guard.git / commitdiff