chiark / gitweb /
seccomp: add helper call to add all secondary archs to a seccomp filter
[elogind.git] / man / systemd.exec.xml
index 207592dda70c7c42198d167b4a480edc4098b726..e82e1f59f0ec87d6fa4c56849175558c6177aef8 100644 (file)
                                 <listitem><para>Controls the CPU
                                 affinity of the executed
                                 processes. Takes a space-separated
                                 <listitem><para>Controls the CPU
                                 affinity of the executed
                                 processes. Takes a space-separated
-                                list of CPU indexes. This option may
+                                list of CPU indices. This option may
                                 be specified more than once in which
                                 case the specificed CPU affinity masks
                                 are merged. If the empty string is
                                 be specified more than once in which
                                 case the specificed CPU affinity masks
                                 are merged. If the empty string is
                                 for the assignment.</para>
 
                                 <para>Example:
                                 for the assignment.</para>
 
                                 <para>Example:
-                                <programlisting>Environment="VAR1=word1 word2" VAR2=word3 "VAR3=word 5 6"</programlisting>
+                                <programlisting>Environment="VAR1=word1 word2" VAR2=word3 "VAR3=$word 5 6"</programlisting>
                                 gives three variables <literal>VAR1</literal>,
                                 gives three variables <literal>VAR1</literal>,
-                                <literal>VAR2</literal>, <literal>VAR3</literal>.
+                                <literal>VAR2</literal>, <literal>VAR3</literal>
+                                with the values <literal>word1 word2</literal>,
+                                <literal>word3</literal>, <literal>$word 5 6</literal>.
                                 </para>
 
                                 <para>
                                 </para>
 
                                 <para>
                         <varlistentry>
                                 <term><varname>StandardError=</varname></term>
                                 <listitem><para>Controls where file
                         <varlistentry>
                                 <term><varname>StandardError=</varname></term>
                                 <listitem><para>Controls where file
-                                descriptor 2 (STDERR) of the executed
-                                processes is connected to. The
-                                available options are identical to
+                                descriptor 2 (standard error) of the
+                                executed processes is connected to.
+                                The available options are identical to
                                 those of
                                 <varname>StandardOutput=</varname>,
                                 with one exception: if set to
                                 those of
                                 <varname>StandardOutput=</varname>,
                                 with one exception: if set to
                         <varlistentry>
                                 <term><varname>TTYPath=</varname></term>
                                 <listitem><para>Sets the terminal
                         <varlistentry>
                                 <term><varname>TTYPath=</varname></term>
                                 <listitem><para>Sets the terminal
-                                device node to use if standard input,
-                                output or stderr are connected to a
+                                device node to use if standard input, output,
+                                or error are connected to a
                                 TTY (see above). Defaults to
                                 <filename>/dev/console</filename>.</para></listitem>
                         </varlistentry>
                                 TTY (see above). Defaults to
                                 <filename>/dev/console</filename>.</para></listitem>
                         </varlistentry>
                                 processes and mounts private
                                 <filename>/tmp</filename> and
                                 <filename>/var/tmp</filename>
                                 processes and mounts private
                                 <filename>/tmp</filename> and
                                 <filename>/var/tmp</filename>
-                                directories inside it, that are not
+                                directories inside it that is not
                                 shared by processes outside of the
                                 namespace. This is useful to secure
                                 access to temporary files of the
                                 shared by processes outside of the
                                 namespace. This is useful to secure
                                 access to temporary files of the
                                 <filename>/var/tmp</filename>
                                 impossible. All temporary data created
                                 by service will be removed after
                                 <filename>/var/tmp</filename>
                                 impossible. All temporary data created
                                 by service will be removed after
-                                service is stopped. Defaults to
+                                the service is stopped. Defaults to
                                 false. Note that it is possible to run
                                 two or more units within the same
                                 private <filename>/tmp</filename> and
                                 false. Note that it is possible to run
                                 two or more units within the same
                                 private <filename>/tmp</filename> and
                                 for details.</para></listitem>
                         </varlistentry>
 
                                 for details.</para></listitem>
                         </varlistentry>
 
+                        <varlistentry>
+                                <term><varname>PrivateDevices=</varname></term>
+
+                                <listitem><para>Takes a boolean
+                                argument. If true, sets up a new /dev
+                                namespace for the executed processes
+                                and only adds API pseudo devices such
+                                as <filename>/dev/null</filename>,
+                                <filename>/dev/zero</filename> or
+                                <filename>/dev/random</filename> to
+                                it, but no physical devices such as
+                                <filename>/dev/sda</filename>. This is
+                                useful to securely turn off physical
+                                device access by the executed
+                                process. Defaults to
+                                false.</para></listitem>
+                        </varlistentry>
+
                         <varlistentry>
                                 <term><varname>MountFlags=</varname></term>
 
                         <varlistentry>
                                 <term><varname>MountFlags=</varname></term>
 
                                 this service.</para></listitem>
                         </varlistentry>
 
                                 this service.</para></listitem>
                         </varlistentry>
 
+                        <varlistentry>
+                                <term><varname>SELinuxContext=</varname></term>
+
+                                <listitem><para>Set the SELinux
+                                security context of the executed
+                                process. If set, this will override
+                                the automated domain
+                                transition. However, the policy still
+                                needs to autorize the transition. This
+                                directive is ignored if SELinux is
+                                disabled. If prefixed by
+                                <literal>-</literal>, all errors will
+                                be ignored. See
+                                <citerefentry><refentrytitle>setexeccon</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+                                for details.</para></listitem>
+                        </varlistentry>
+
                         <varlistentry>
                                 <term><varname>IgnoreSIGPIPE=</varname></term>
 
                         <varlistentry>
                                 <term><varname>IgnoreSIGPIPE=</varname></term>
 
                                 list of system call
                                 names. If this setting is used, all
                                 system calls executed by the unit
                                 list of system call
                                 names. If this setting is used, all
                                 system calls executed by the unit
-                                process except for the listed ones
+                                processes except for the listed ones
                                 will result in immediate process
                                 termination with the
                                 <constant>SIGSYS</constant> signal
                                 will result in immediate process
                                 termination with the
                                 <constant>SIGSYS</constant> signal
                                 merged. If the empty string is
                                 assigned, the filter is reset, all
                                 prior assignments will have no
                                 merged. If the empty string is
                                 assigned, the filter is reset, all
                                 prior assignments will have no
-                                effect.</para></listitem>
+                                effect.</para>
+
+                                <para>If you specify both types of
+                                this option (i.e. whitelisting and
+                                blacklisting), the first encountered
+                                will take precedence and will dictate
+                                the default action (termination or
+                                approval of a system call). Then the
+                                next occurrences of this option will
+                                add or delete the listed system calls
+                                from the set of the filtered system
+                                calls, depending of its type and the
+                                default action. (For example, if you have started
+                                with a whitelisting of
+                                <function>read</function> and
+                                <function>write</function>, and right
+                                after it add a blacklisting of
+                                <function>write</function>, then
+                                <function>write</function> will be
+                                removed from the set.)
+                                </para></listitem>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term><varname>SystemCallErrorNumber=</varname></term>
+
+                                <listitem><para>Takes an
+                                <literal>errno</literal> error number
+                                name to return when the system call
+                                filter configured with
+                                <varname>SystemCallFilter=</varname>
+                                is triggered, instead of terminating
+                                the process immediately. Takes an
+                                error name such as
+                                <literal>EPERM</literal>,
+                                <literal>EACCES</literal> or
+                                <literal>EUCLEAN</literal>. When this
+                                setting is not used, or when the empty
+                                string is assigned, the process will be
+                                terminated immediately when the filter
+                                is triggered.</para></listitem>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term><varname>SystemCallArchitectures=</varname></term>
+
+                                <listitem><para>Takes a space
+                                separated list of architecture
+                                identifiers to include in the system
+                                call filter. The known architecture
+                                identifiers are
+                                <literal>x86</literal>,
+                                <literal>x86-64</literal>,
+                                <literal>x32</literal>,
+                                <literal>arm</literal> as well as the
+                                special identifier
+                                <literal>native</literal>. Only system
+                                calls of the specified architectures
+                                will be permitted to processes of this
+                                unit. This is an effective way to
+                                disable compatibility with non-native
+                                architectures for processes, for
+                                example to prohibit execution of
+                                32-bit x86 binaries on 64-bit x86-64
+                                systems. The special
+                                <literal>native</literal> identifier
+                                implicitly maps to the native
+                                architecture of the system (or more
+                                strictly: to the architecture the
+                                system manager is compiled for). Note
+                                that setting this option to a
+                                non-empty list implies that
+                                <literal>native</literal> is included
+                                too. By default, this option is set to
+                                the empty list, i.e. no architecture
+                                system call filtering is
+                                applied.</para></listitem>
                         </varlistentry>
 
                 </variablelist>
                         </varlistentry>
 
                 </variablelist>