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  • Committer: Teddy Hogeborn
  • Date: 2015-07-02 18:22:22 UTC
  • mto: (237.7.307 trunk)
  • mto: This revision was merged to the branch mainline in revision 325.
  • Revision ID: teddy@recompile.se-20150702182222-034v03mb8orwhezn
mandos-client: Minor changes to check for more error conditions.

* mandos-client.c (add_remove_local_route): Do TEMP_FAILURE_RETRY
                                            around closing of
                                            /dev/null.  Check return
                                            value when opening helper
                                            directory and helper
                                            executable.
  (run_network_hooks): Cast return value of TEMP_FAILURE_RETRY to int.
                       Do TEMP_FAILURE_RETRY around closing of
                       /dev/null.

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plugins.d/usplash.xml
 
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<?xml version="1.0" encoding="UTF-8"?>
 
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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
 
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        "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
 
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<!ENTITY COMMANDNAME "usplash">
 
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<!ENTITY TIMESTAMP "2012-01-01">
 
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<!ENTITY % common SYSTEM "../common.ent">
 
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%common;
 
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]>
 
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<refentry xmlns:xi="http://www.w3.org/2001/XInclude">
 
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  <refentryinfo>
 
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    <title>Mandos Manual</title>
 
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    <!-- NWalsh’s docbook scripts use this to generate the footer: -->
 
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    <productname>Mandos</productname>
 
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    <productnumber>&version;</productnumber>
 
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    <date>&TIMESTAMP;</date>
 
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    <authorgroup>
 
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      <author>
 
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        <firstname>Björn</firstname>
 
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        <surname>Påhlsson</surname>
 
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        <address>
 
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          <email>belorn@recompile.se</email>
 
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        </address>
 
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      </author>
 
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      <author>
 
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        <firstname>Teddy</firstname>
 
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        <surname>Hogeborn</surname>
 
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        <address>
 
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          <email>teddy@recompile.se</email>
 
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        </address>
 
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      </author>
 
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    </authorgroup>
 
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    <copyright>
 
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      <year>2008</year>
 
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      <year>2009</year>
 
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      <year>2011</year>
 
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      <year>2012</year>
 
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      <holder>Teddy Hogeborn</holder>
 
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      <holder>Björn Påhlsson</holder>
 
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    </copyright>
 
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    <xi:include href="../legalnotice.xml"/>
 
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  </refentryinfo>
 
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  <refmeta>
 
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    <refentrytitle>&COMMANDNAME;</refentrytitle>
 
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    <manvolnum>8mandos</manvolnum>
 
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  </refmeta>
 
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  <refnamediv>
 
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    <refname><command>&COMMANDNAME;</command></refname>
 
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    <refpurpose>Mandos plugin to use usplash to get a
 
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    password.</refpurpose>
 
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  </refnamediv>
 
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  <refsynopsisdiv>
 
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    <cmdsynopsis>
 
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      <command>&COMMANDNAME;</command>
 
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    </cmdsynopsis>
 
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  </refsynopsisdiv>
 
60
  
 
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  <refsect1 id="description">
 
62
    <title>DESCRIPTION</title>
 
63
    <para>
 
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      This program prompts for a password using <citerefentry>
 
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      <refentrytitle>usplash</refentrytitle><manvolnum>8</manvolnum>
 
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      </citerefentry> and outputs any given password to standard
 
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      output.  If no <citerefentry><refentrytitle
 
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      >usplash</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 
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      process can be found, this program will immediately exit with an
 
70
      exit code indicating failure.
 
71
    </para>
 
72
    <para>
 
73
      This program is not very useful on its own.  This program is
 
74
      really meant to run as a plugin in the <application
 
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      >Mandos</application> client-side system, where it is used as a
 
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      fallback and alternative to retrieving passwords from a
 
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      <application >Mandos</application> server.
 
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    </para>
 
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    <para>
 
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      If this program is killed (presumably by
 
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      <citerefentry><refentrytitle>plugin-runner</refentrytitle>
 
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      <manvolnum>8mandos</manvolnum></citerefentry> because some other
 
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      plugin provided the password), it cannot tell <citerefentry>
 
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      <refentrytitle>usplash</refentrytitle><manvolnum>8</manvolnum>
 
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      </citerefentry> to abort requesting a password, because
 
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      <citerefentry><refentrytitle>usplash</refentrytitle>
 
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      <manvolnum>8</manvolnum></citerefentry> does not support this.
 
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      Therefore, this program will then <emphasis>kill</emphasis> the
 
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      running <citerefentry><refentrytitle>usplash</refentrytitle>
 
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      <manvolnum>8</manvolnum></citerefentry> process and start a
 
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      <emphasis>new</emphasis> one using the same command line
 
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      arguments as the old one was using.
 
93
    </para>
 
94
  </refsect1>
 
95
  
 
96
  <refsect1 id="options">
 
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    <title>OPTIONS</title>
 
98
    <para>
 
99
      This program takes no options.
 
100
    </para>
 
101
  </refsect1>
 
102
  
 
103
  <refsect1 id="exit_status">
 
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    <title>EXIT STATUS</title>
 
105
    <para>
 
106
      If exit status is 0, the output from the program is the password
 
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      as it was read.  Otherwise, if exit status is other than 0, the
 
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      program was interrupted or encountered an error, and any output
 
109
      so far could be corrupt and/or truncated, and should therefore
 
110
      be ignored.
 
111
    </para>
 
112
  </refsect1>
 
113
  
 
114
  <refsect1 id="environment">
 
115
    <title>ENVIRONMENT</title>
 
116
    <variablelist>
 
117
      <varlistentry>
 
118
        <term><envar>cryptsource</envar></term>
 
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        <term><envar>crypttarget</envar></term>
 
120
        <listitem>
 
121
          <para>
 
122
            If set, these environment variables will be assumed to
 
123
            contain the source device name and the target device
 
124
            mapper name, respectively, and will be shown as part of
 
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            the prompt.
 
126
        </para>
 
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        <para>
 
128
          These variables will normally be inherited from
 
129
          <citerefentry><refentrytitle>plugin-runner</refentrytitle>
 
130
          <manvolnum>8mandos</manvolnum></citerefentry>, which will
 
131
          normally have inherited them from
 
132
          <filename>/scripts/local-top/cryptroot</filename> in the
 
133
          initial <acronym>RAM</acronym> disk environment, which will
 
134
          have set them from parsing kernel arguments and
 
135
          <filename>/conf/conf.d/cryptroot</filename> (also in the
 
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          initial RAM disk environment), which in turn will have been
 
137
          created when the initial RAM disk image was created by
 
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          <filename
 
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          >/usr/share/initramfs-tools/hooks/cryptroot</filename>, by
 
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          extracting the information of the root file system from
 
141
          <filename >/etc/crypttab</filename>.
 
142
        </para>
 
143
        <para>
 
144
          This behavior is meant to exactly mirror the behavior of
 
145
          <command>askpass</command>, the default password prompter.
 
146
        </para>
 
147
        </listitem>
 
148
      </varlistentry>
 
149
    </variablelist>
 
150
  </refsect1>
 
151
  
 
152
  <refsect1 id="files">
 
153
    <title>FILES</title>
 
154
    <variablelist>
 
155
      <varlistentry>
 
156
        <term><filename>/dev/.initramfs/usplash_fifo</filename></term>
 
157
        <listitem>
 
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          <para>
 
159
            This is the <acronym>FIFO</acronym> to where this program
 
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            will write the commands for <citerefentry><refentrytitle
 
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            >usplash</refentrytitle><manvolnum>8</manvolnum>
 
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            </citerefentry>.  See <citerefentry><refentrytitle
 
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            >fifo</refentrytitle><manvolnum>7</manvolnum>
 
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            </citerefentry>.
 
165
          </para>
 
166
        </listitem>
 
167
      </varlistentry>
 
168
      <varlistentry>
 
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        <term><filename>/dev/.initramfs/usplash_outfifo</filename></term>
 
170
        <listitem>
 
171
          <para>
 
172
            This is the <acronym>FIFO</acronym> where this program
 
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            will read the password from <citerefentry><refentrytitle
 
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            >usplash</refentrytitle><manvolnum>8</manvolnum>
 
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            </citerefentry>.  See <citerefentry><refentrytitle
 
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            >fifo</refentrytitle><manvolnum>7</manvolnum>
 
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            </citerefentry>.
 
178
          </para>
 
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        </listitem>
 
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      </varlistentry>
 
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      <varlistentry>
 
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        <term><filename class="directory">/proc</filename></term>
 
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        <listitem>
 
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          <para>
 
185
            To find the running <citerefentry><refentrytitle
 
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            >usplash</refentrytitle><manvolnum>8</manvolnum>
 
187
            </citerefentry>, this directory will be searched for
 
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            numeric entries which will be assumed to be directories.
 
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            In all those directories, the <filename>exe</filename> and
 
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            <filename>cmdline</filename> entries will be used to
 
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            determine the name of the running binary, effective user
 
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            and group <abbrev>ID</abbrev>, and the command line
 
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            arguments.  See <citerefentry><refentrytitle
 
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            >proc</refentrytitle><manvolnum>5</manvolnum>
 
195
            </citerefentry>.
 
196
          </para>
 
197
        </listitem>
 
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      </varlistentry>
 
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      <varlistentry>
 
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        <term><filename>/sbin/usplash</filename></term>
 
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        <listitem>
 
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          <para>
 
203
            This is the name of the binary which will be searched for
 
204
            in the process list.  See <citerefentry><refentrytitle
 
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            >usplash</refentrytitle><manvolnum>8</manvolnum>
 
206
            </citerefentry>.
 
207
          </para>
 
208
        </listitem>
 
209
      </varlistentry>
 
210
    </variablelist>
 
211
  </refsect1>
 
212
  
 
213
  <refsect1 id="bugs">
 
214
    <title>BUGS</title>
 
215
    <para>
 
216
      Killing <citerefentry><refentrytitle>usplash</refentrytitle>
 
217
      <manvolnum>8</manvolnum></citerefentry> and starting a new one
 
218
      is ugly, but necessary as long as it does not support aborting a
 
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      password request.
 
220
    </para>
 
221
  </refsect1>
 
222
  
 
223
  <refsect1 id="example">
 
224
    <title>EXAMPLE</title>
 
225
    <para>
 
226
      Note that normally, this program will not be invoked directly,
 
227
      but instead started by the Mandos <citerefentry><refentrytitle
 
228
      >plugin-runner</refentrytitle><manvolnum>8mandos</manvolnum>
 
229
      </citerefentry>.
 
230
    </para>
 
231
    <informalexample>
 
232
      <para>
 
233
        This program takes no options.
 
234
      </para>
 
235
      <para>
 
236
        <userinput>&COMMANDNAME;</userinput>
 
237
      </para>
 
238
    </informalexample>
 
239
  </refsect1>
 
240
  
 
241
  <refsect1 id="security">
 
242
    <title>SECURITY</title>
 
243
    <para>
 
244
      If this program is killed by a signal, it will kill the process
 
245
      <abbrev>ID</abbrev> which at the start of this program was
 
246
      determined to run <citerefentry><refentrytitle
 
247
      >usplash</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 
248
      as root (see also <xref linkend="files"/>).  There is a very
 
249
      slight risk that, in the time between those events, that process
 
250
      <abbrev>ID</abbrev> was freed and then taken up by another
 
251
      process; the wrong process would then be killed.  Now, this
 
252
      program can only be killed by the user who started it; see
 
253
      <citerefentry><refentrytitle>plugin-runner</refentrytitle>
 
254
      <manvolnum>8mandos</manvolnum></citerefentry>.  This program
 
255
      should therefore be started by a completely separate
 
256
      non-privileged user, and no other programs should be allowed to
 
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      run as that special user.  This means that it is not recommended
 
258
      to use the user "nobody" to start this program, as other
 
259
      possibly less trusted programs could be running as "nobody", and
 
260
      they would then be able to kill this program, triggering the
 
261
      killing of the process <abbrev>ID</abbrev> which may or may not
 
262
      be <citerefentry><refentrytitle>usplash</refentrytitle>
 
263
      <manvolnum>8</manvolnum></citerefentry>.
 
264
    </para>
 
265
    <para>
 
266
      The only other thing that could be considered worthy of note is
 
267
      this:  This program is meant to be run by <citerefentry>
 
268
      <refentrytitle>plugin-runner</refentrytitle><manvolnum
 
269
      >8mandos</manvolnum></citerefentry>, and will, when run
 
270
      standalone, outside, in a normal environment, immediately output
 
271
      on its standard output any presumably secret password it just
 
272
      received.  Therefore, when running this program standalone
 
273
      (which should never normally be done), take care not to type in
 
274
      any real secret password by force of habit, since it would then
 
275
      immediately be shown as output.
 
276
    </para>
 
277
  </refsect1>
 
278
  
 
279
  <refsect1 id="see_also">
 
280
    <title>SEE ALSO</title>
 
281
    <para>
 
282
      <citerefentry><refentrytitle>intro</refentrytitle>
 
283
      <manvolnum>8mandos</manvolnum></citerefentry>,
 
284
      <citerefentry><refentrytitle>crypttab</refentrytitle>
 
285
      <manvolnum>5</manvolnum></citerefentry>,
 
286
      <citerefentry><refentrytitle>fifo</refentrytitle>
 
287
      <manvolnum>7</manvolnum></citerefentry>,
 
288
      <citerefentry><refentrytitle>plugin-runner</refentrytitle>
 
289
      <manvolnum>8mandos</manvolnum></citerefentry>,
 
290
      <citerefentry><refentrytitle>proc</refentrytitle>
 
291
      <manvolnum>5</manvolnum></citerefentry>,
 
292
      <citerefentry><refentrytitle>usplash</refentrytitle>
 
293
      <manvolnum>8</manvolnum></citerefentry>
 
294
    </para>
 
295
  </refsect1>
 
296
</refentry>
 
297
<!-- Local Variables: -->
 
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<!-- time-stamp-start: "<!ENTITY TIMESTAMP [\"']" -->
 
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<!-- time-stamp-end: "[\"']>" -->
 
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<!-- time-stamp-format: "%:y-%02m-%02d" -->
 
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<!-- End: -->