man/sd_bus_creds_get_pid.xml

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   8
   9 <refentry id="sd_bus_creds_get_pid" xmlns:xi="http://www.w3.org/2001/XInclude">
  10
  11   <refentryinfo>
  12     <title>sd_bus_creds_get_pid</title>
  13     <productname>systemd</productname>
  14
  15     <authorgroup>
  16       <author>
  17         <contrib>A monkey with a typewriter</contrib>
  18         <firstname>Zbigniew</firstname>
  19         <surname>Jędrzejewski-Szmek</surname>
  20         <email>zbyszek@in.waw.pl</email>
  21       </author>
  22     </authorgroup>
  23   </refentryinfo>
  24
  25   <refmeta>
  26     <refentrytitle>sd_bus_creds_get_pid</refentrytitle>
  27     <manvolnum>3</manvolnum>
  28   </refmeta>
  29
  30   <refnamediv>
  31     <refname>sd_bus_creds_get_pid</refname>
  32     <refname>sd_bus_creds_get_ppid</refname>
  33     <refname>sd_bus_creds_get_tid</refname>
  34     <refname>sd_bus_creds_get_uid</refname>
  35     <refname>sd_bus_creds_get_euid</refname>
  36     <refname>sd_bus_creds_get_suid</refname>
  37     <refname>sd_bus_creds_get_fsuid</refname>
  38     <refname>sd_bus_creds_get_gid</refname>
  39     <refname>sd_bus_creds_get_egid</refname>
  40     <refname>sd_bus_creds_get_sgid</refname>
  41     <refname>sd_bus_creds_get_fsgid</refname>
  42     <refname>sd_bus_creds_get_supplementary_gids</refname>
  43     <refname>sd_bus_creds_get_comm</refname>
  44     <refname>sd_bus_creds_get_tid_comm</refname>
  45     <refname>sd_bus_creds_get_exe</refname>
  46     <refname>sd_bus_creds_get_cmdline</refname>
  47     <refname>sd_bus_creds_get_cgroup</refname>
  48     <refname>sd_bus_creds_get_unit</refname>
  49     <refname>sd_bus_creds_get_slice</refname>
  50     <refname>sd_bus_creds_get_user_unit</refname>
  51     <refname>sd_bus_creds_get_user_slice</refname>
  52     <refname>sd_bus_creds_get_session</refname>
  53     <refname>sd_bus_creds_get_owner_uid</refname>
  54     <refname>sd_bus_creds_has_effective_cap</refname>
  55     <refname>sd_bus_creds_has_permitted_cap</refname>
  56     <refname>sd_bus_creds_has_inheritable_cap</refname>
  57     <refname>sd_bus_creds_has_bounding_cap</refname>
  58     <refname>sd_bus_creds_get_selinux_context</refname>
  59     <refname>sd_bus_creds_get_audit_session_id</refname>
  60     <refname>sd_bus_creds_get_audit_login_uid</refname>
  61     <refname>sd_bus_creds_get_tty</refname>
  62     <refname>sd_bus_creds_get_unique_name</refname>
  63     <refname>sd_bus_creds_get_well_known_names</refname>
  64     <refname>sd_bus_creds_get_description</refname>
  65
  66     <refpurpose>Retrieve fields from a credentials object</refpurpose>
  67   </refnamediv>
  68
  69   <refsynopsisdiv>
  70     <funcsynopsis>
  71       <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
  72
  73       <funcprototype>
  74         <funcdef>int <function>sd_bus_creds_get_pid</function></funcdef>
  75         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
  76         <paramdef>pid_t *<parameter>pid</parameter></paramdef>
  77       </funcprototype>
  78
  79       <funcprototype>
  80         <funcdef>int <function>sd_bus_creds_get_ppid</function></funcdef>
  81         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
  82         <paramdef>pid_t *<parameter>ppid</parameter></paramdef>
  83       </funcprototype>
  84
  85       <funcprototype>
  86         <funcdef>int <function>sd_bus_creds_get_tid</function></funcdef>
  87         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
  88         <paramdef>pid_t *<parameter>tid</parameter></paramdef>
  89       </funcprototype>
  90
  91       <funcprototype>
  92         <funcdef>int <function>sd_bus_creds_get_uid</function></funcdef>
  93         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
  94         <paramdef>uid_t *<parameter>uid</parameter></paramdef>
  95       </funcprototype>
  96
  97       <funcprototype>
  98         <funcdef>int <function>sd_bus_creds_get_euid</function></funcdef>
  99         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 100         <paramdef>uid_t *<parameter>uid</parameter></paramdef>
 101       </funcprototype>
 102
 103       <funcprototype>
 104         <funcdef>int <function>sd_bus_creds_get_suid</function></funcdef>
 105         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 106         <paramdef>uid_t *<parameter>uid</parameter></paramdef>
 107       </funcprototype>
 108
 109       <funcprototype>
 110         <funcdef>int <function>sd_bus_creds_get_fsuid</function></funcdef>
 111         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 112         <paramdef>uid_t *<parameter>uid</parameter></paramdef>
 113       </funcprototype>
 114
 115       <funcprototype>
 116         <funcdef>int <function>sd_bus_creds_get_gid</function></funcdef>
 117         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 118         <paramdef>gid_t *<parameter>gid</parameter></paramdef>
 119       </funcprototype>
 120
 121       <funcprototype>
 122         <funcdef>int <function>sd_bus_creds_get_egid</function></funcdef>
 123         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 124         <paramdef>gid_t *<parameter>gid</parameter></paramdef>
 125       </funcprototype>
 126
 127       <funcprototype>
 128         <funcdef>int <function>sd_bus_creds_get_sgid</function></funcdef>
 129         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 130         <paramdef>gid_t *<parameter>gid</parameter></paramdef>
 131       </funcprototype>
 132
 133       <funcprototype>
 134         <funcdef>int <function>sd_bus_creds_get_fsgid</function></funcdef>
 135         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 136         <paramdef>gid_t *<parameter>gid</parameter></paramdef>
 137       </funcprototype>
 138
 139       <funcprototype>
 140         <funcdef>int <function>sd_bus_creds_get_supplementary_gids</function></funcdef>
 141         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 142         <paramdef>const gid_t **<parameter>gids</parameter></paramdef>
 143       </funcprototype>
 144
 145       <funcprototype>
 146         <funcdef>int <function>sd_bus_creds_get_comm</function></funcdef>
 147         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 148         <paramdef>const char **<parameter>comm</parameter></paramdef>
 149       </funcprototype>
 150
 151       <funcprototype>
 152         <funcdef>int <function>sd_bus_creds_get_tid_comm</function></funcdef>
 153         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 154         <paramdef>const char **<parameter>comm</parameter></paramdef>
 155       </funcprototype>
 156
 157       <funcprototype>
 158         <funcdef>int <function>sd_bus_creds_get_exe</function></funcdef>
 159         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 160         <paramdef>const char **<parameter>exe</parameter></paramdef>
 161       </funcprototype>
 162
 163       <funcprototype>
 164         <funcdef>int <function>sd_bus_creds_get_cmdline</function></funcdef>
 165         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 166         <paramdef>char ***<parameter>cmdline</parameter></paramdef>
 167       </funcprototype>
 168
 169       <funcprototype>
 170         <funcdef>int <function>sd_bus_creds_get_cgroup</function></funcdef>
 171         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 172         <paramdef>const char **<parameter>cgroup</parameter></paramdef>
 173       </funcprototype>
 174
 175       <funcprototype>
 176         <funcdef>int <function>sd_bus_creds_get_unit</function></funcdef>
 177         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 178         <paramdef>const char **<parameter>unit</parameter></paramdef>
 179       </funcprototype>
 180
 181       <funcprototype>
 182         <funcdef>int <function>sd_bus_creds_get_slice</function></funcdef>
 183         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 184         <paramdef>const char **<parameter>slice</parameter></paramdef>
 185       </funcprototype>
 186
 187       <funcprototype>
 188         <funcdef>int <function>sd_bus_creds_get_user_unit</function></funcdef>
 189         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 190         <paramdef>const char **<parameter>unit</parameter></paramdef>
 191       </funcprototype>
 192
 193       <funcprototype>
 194         <funcdef>int <function>sd_bus_creds_get_user_slice</function></funcdef>
 195         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 196         <paramdef>const char **<parameter>slice</parameter></paramdef>
 197       </funcprototype>
 198
 199       <funcprototype>
 200         <funcdef>int <function>sd_bus_creds_get_session</function></funcdef>
 201         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 202         <paramdef>const char **<parameter>slice</parameter></paramdef>
 203       </funcprototype>
 204
 205       <funcprototype>
 206         <funcdef>int <function>sd_bus_creds_get_owner_uid</function></funcdef>
 207         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 208         <paramdef>uid_t *<parameter>uid</parameter></paramdef>
 209       </funcprototype>
 210
 211       <funcprototype>
 212         <funcdef>int <function>sd_bus_creds_has_effective_cap</function></funcdef>
 213         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 214         <paramdef>int <parameter>capability</parameter></paramdef>
 215       </funcprototype>
 216
 217       <funcprototype>
 218         <funcdef>int <function>sd_bus_creds_has_permitted_cap</function></funcdef>
 219         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 220         <paramdef>int <parameter>capability</parameter></paramdef>
 221       </funcprototype>
 222
 223       <funcprototype>
 224         <funcdef>int <function>sd_bus_creds_has_inheritable_cap</function></funcdef>
 225         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 226         <paramdef>int <parameter>capability</parameter></paramdef>
 227       </funcprototype>
 228
 229       <funcprototype>
 230         <funcdef>int <function>sd_bus_creds_has_bounding_cap</function></funcdef>
 231         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 232         <paramdef>int <parameter>capability</parameter></paramdef>
 233       </funcprototype>
 234
 235       <funcprototype>
 236         <funcdef>int <function>sd_bus_creds_get_selinux_context</function></funcdef>
 237         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 238         <paramdef>const char **<parameter>context</parameter></paramdef>
 239       </funcprototype>
 240
 241       <funcprototype>
 242         <funcdef>int <function>sd_bus_creds_get_audit_session_id</function></funcdef>
 243         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 244         <paramdef>uint32_t *<parameter>sessionid</parameter></paramdef>
 245       </funcprototype>
 246
 247       <funcprototype>
 248         <funcdef>int <function>sd_bus_creds_get_audit_login_uid</function></funcdef>
 249         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 250         <paramdef>uid_t *<parameter>loginuid</parameter></paramdef>
 251       </funcprototype>
 252
 253       <funcprototype>
 254         <funcdef>int <function>sd_bus_creds_get_tty</function></funcdef>
 255         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 256         <paramdef>const char **<parameter>tty</parameter></paramdef>
 257       </funcprototype>
 258
 259       <funcprototype>
 260         <funcdef>int <function>sd_bus_creds_get_unique_name</function></funcdef>
 261         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 262         <paramdef>const char **<parameter>name</parameter></paramdef>
 263       </funcprototype>
 264
 265       <funcprototype>
 266         <funcdef>int <function>sd_bus_creds_get_well_known_names</function></funcdef>
 267         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 268         <paramdef>char ***<parameter>name</parameter></paramdef>
 269       </funcprototype>
 270
 271       <funcprototype>
 272         <funcdef>int <function>sd_bus_creds_get_description</function></funcdef>
 273         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 274         <paramdef>const char **<parameter>name</parameter></paramdef>
 275       </funcprototype>
 276
 277     </funcsynopsis>
 278   </refsynopsisdiv>
 279
 280   <refsect1>
 281     <title>Description</title>
 282
 283     <para>These functions return credential information from an
 284     <parameter>sd_bus_creds</parameter> object. Credential objects may
 285     be created with
 286     <citerefentry><refentrytitle>sd_bus_creds_new_from_pid</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 287     in which case they describe the credentials of the process
 288     identified by the specified PID, with
 289     <citerefentry><refentrytitle>sd_bus_get_name_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 290     in which case they describe the credentials of a bus peer
 291     identified by the specified bus name, with
 292     <citerefentry><refentrytitle>sd_bus_get_owner_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 293     in which case they describe the credentials of the creator of a
 294     bus, or with
 295     <citerefentry><refentrytitle>sd_bus_message_get_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 296     in which case they describe the credentials of the sender of the
 297     message.</para>
 298
 299     <para>Not all credential fields are part of every
 300     <literal>sd_bus_creds</literal> object. Use
 301     <citerefentry><refentrytitle>sd_bus_creds_get_mask</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 302     to determine the mask of fields available.</para>
 303
 304     <para><function>sd_bus_creds_get_pid()</function> will retrieve
 305     the PID (process identifier). Similarly,
 306     <function>sd_bus_creds_get_ppid()</function> will retrieve the
 307     parent PID. Note that PID 1 has no parent process, in which case
 308     -ENXIO is returned.</para>
 309
 310     <para><function>sd_bus_creds_get_tid()</function> will retrieve the
 311     TID (thread identifier).</para>
 312
 313     <para><function>sd_bus_creds_get_uid()</function> will retrieve
 314     the numeric UID (user identifier). Similarly,
 315     <function>sd_bus_creds_get_euid()</function> returns the effective
 316     UID, <function>sd_bus_creds_get_suid()</function> the saved UID
 317     and <function>sd_bus_creds_get_fsuid()</function> the file system
 318     UID.</para>
 319
 320     <para><function>sd_bus_creds_get_gid()</function> will retrieve the
 321     numeric GID (group identifier). Similarly,
 322     <function>sd_bus_creds_get_egid()</function> returns the effective
 323     GID, <function>sd_bus_creds_get_sgid()</function> the saved GID
 324     and <function>sd_bus_creds_get_fsgid()</function> the file system
 325     GID.</para>
 326
 327     <para><function>sd_bus_creds_get_supplementary_gids()</function>
 328     will retrieve the supplementary GIDs list.</para>
 329
 330     <para><function>sd_bus_creds_get_comm()</function> will retrieve the
 331     comm field (truncated name of the executable, as stored in
 332     <filename>/proc/<replaceable>pid</replaceable>/comm</filename>).
 333     </para>
 334
 335     <para><function>sd_bus_creds_get_tid_comm()</function> will retrieve
 336     the comm field of the thread (as stored in
 337     <filename>/proc/<replaceable>pid</replaceable>/task/<replaceable>tid</replaceable>/comm</filename>).
 338     </para>
 339
 340     <para><function>sd_bus_creds_get_exe()</function> will retrieve
 341     the path to the program executable (as stored in the
 342     <filename>/proc/<replaceable>pid</replaceable>/exe</filename>
 343     link, but with the <literal> (deleted)</literal> suffix removed). Note
 344     that kernel threads do not have an executable path, in which case
 345     -ENXIO is returned.</para>
 346
 347     <para><function>sd_bus_creds_get_cmdline()</function> will
 348     retrieve an array of command line arguments (as stored in
 349     <filename>/proc/<replaceable>pid</replaceable>/cmdline</filename>). Note
 350     that kernel threads do not have a command line, in which case
 351     -ENXIO is returned.</para>
 352
 353     <para><function>sd_bus_creds_get_cgroup()</function> will retrieve
 354     the control group path. See <ulink
 355     url="https://www.kernel.org/doc/Documentation/cgroup-v1/cgroups.txt">cgroups.txt</ulink>.
 356     </para>
 357
 358     <para><function>sd_bus_creds_get_unit()</function> will retrieve
 359     the systemd unit name (in the system instance of systemd) that the
 360     process is a part of. See
 361     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. For
 362     processes that are not part of a unit, returns -ENXIO.
 363     </para>
 364
 365     <para><function>sd_bus_creds_get_user_unit()</function> will
 366     retrieve the systemd unit name (in the user instance of systemd)
 367     that the process is a part of. See
 368     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. For
 369     processes that are not part of a user unit, returns -ENXIO.
 370     </para>
 371
 372     <para><function>sd_bus_creds_get_slice()</function> will retrieve
 373     the systemd slice (a unit in the system instance of systemd) that
 374     the process is a part of. See
 375     <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Similarly,
 376     <function>sd_bus_creds_get_user_slice()</function> retrieves the
 377     systemd slice of the process, in the user instance of systemd.
 378     </para>
 379
 380     <para><function>sd_bus_creds_get_session()</function> will
 381     retrieve the identifier of the login session that the process is
 382     a part of. Please note the login session may be limited to a stub
 383     process or two.  User processes may instead be started from their
 384     systemd user manager, e.g. GUI applications started using DBus
 385     activation, as well as service processes which are shared between
 386     multiple logins of the same user. For processes that are not part
 387     of a session, returns -ENXIO.</para>
 388
 389     <para><function>sd_bus_creds_get_owner_uid()</function> will
 390     retrieve the numeric UID (user identifier) of the user who owns
 391     the user unit or login session that the process is a part of. See
 392     <citerefentry><refentrytitle>systemd-logind.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
 393     For processes that are not part of a user unit or session, returns
 394     -ENXIO.
 395     </para>
 396
 397     <para><function>sd_bus_creds_has_effective_cap()</function> will check whether the capability specified by
 398     <parameter>capability</parameter> was set in the effective capabilities mask. A positive return value means that it
 399     was set, zero means that it was not set, and a negative return value indicates an error. See <citerefentry
 400     project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry> and the
 401     <varname>AmbientCapabilities=</varname> and <varname>CapabilityBoundingSet=</varname> settings in
 402     <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 403     </para>
 404
 405     <para><function>sd_bus_creds_has_permitted_cap()</function> is
 406     similar to <function>sd_bus_creds_has_effective_cap()</function>,
 407     but will check the permitted capabilities mask.</para>
 408
 409     <para><function>sd_bus_creds_has_inheritable_cap()</function> is
 410     similar to <function>sd_bus_creds_has_effective_cap()</function>,
 411     but will check the inheritable capabilities mask.</para>
 412
 413     <para><function>sd_bus_creds_has_bounding_cap()</function> is
 414     similar to <function>sd_bus_creds_has_effective_cap()</function>,
 415     but will check the bounding capabilities mask.</para>
 416
 417     <para><function>sd_bus_creds_get_selinux_context()</function> will
 418     retrieve the SELinux security context (label) of the process.</para>
 419
 420     <para><function>sd_bus_creds_get_audit_session_id()</function>
 421     will retrieve the audit session identifier of the process. Returns
 422     -ENXIO for processes that are not part of an audit session.</para>
 423
 424     <para><function>sd_bus_creds_get_audit_login_uid()</function> will
 425     retrieve the audit user login identifier (the identifier of the
 426     user who is "responsible" for the session). Returns -ENXIO for
 427     processes that are not part of an audit session.</para>
 428
 429     <para><function>sd_bus_creds_get_tty()</function> will retrieve
 430     the controlling TTY, without the prefixing "/dev/". Returns -ENXIO
 431     for processes that have no controlling TTY.</para>
 432
 433     <para><function>sd_bus_creds_get_unique_name()</function> will
 434     retrieve the D-Bus unique name. See <ulink
 435     url="http://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-names-bus">The
 436     D-Bus specification</ulink>.</para>
 437
 438     <para><function>sd_bus_creds_get_well_known_names()</function> will
 439     retrieve the set of D-Bus well-known names. See <ulink
 440     url="http://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-names-bus">The
 441     D-Bus specification</ulink>.</para>
 442
 443     <para><function>sd_bus_creds_get_description()</function> will
 444     retrieve a descriptive name of the bus connection of the
 445     peer. This name is useful to discern multiple bus connections by
 446     the same peer, and may be altered by the peer with the
 447     <citerefentry><refentrytitle>sd_bus_set_description</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 448     call.</para>
 449
 450     <para>All functions that take a <parameter>const
 451     char**</parameter> parameter will store the answer there as an
 452     address of a NUL-terminated string. It will be valid as long as
 453     <parameter>c</parameter> remains valid, and should not be freed or
 454     modified by the caller.</para>
 455
 456     <para>All functions that take a <parameter>char***</parameter>
 457     parameter will store the answer there as an address of an array
 458     of strings. Each individual string is NUL-terminated, and the
 459     array is NULL-terminated as a whole. It will be valid as long as
 460     <parameter>c</parameter> remains valid, and should not be freed or
 461     modified by the caller.</para>
 462   </refsect1>
 463
 464   <refsect1>
 465     <title>Return Value</title>
 466
 467     <para>On success, these calls return 0 or a positive integer. On
 468     failure, these calls return a negative errno-style error code.
 469     </para>
 470   </refsect1>
 471
 472   <refsect1>
 473     <title>Errors</title>
 474
 475     <para>Returned errors may indicate the following problems:</para>
 476
 477     <variablelist>
 478       <varlistentry>
 479         <term><constant>-ENODATA</constant></term>
 480
 481         <listitem><para>The given field is not available in the
 482         credentials object <parameter>c</parameter>.</para>
 483         </listitem>
 484       </varlistentry>
 485
 486       <varlistentry>
 487         <term><constant>-ENXIO</constant></term>
 488
 489         <listitem><para>The given field is not specified for the described
 490         process or peer. This will be returned by
 491         <function>sd_bus_creds_get_unit()</function>,
 492         <function>sd_bus_creds_get_slice()</function>,
 493         <function>sd_bus_creds_get_user_unit()</function>,
 494         <function>sd_bus_creds_get_user_slice()</function>, and
 495         <function>sd_bus_creds_get_session()</function> if the process is
 496         not part of a systemd system unit, systemd user unit, systemd
 497         slice, or logind session. It will be returned by
 498         <function>sd_bus_creds_get_owner_uid()</function> if the process is
 499         not part of a systemd user unit or logind session. It will also be
 500         returned by <function>sd_bus_creds_get_exe()</function> and
 501         <function>sd_bus_creds_get_cmdline()</function> for kernel
 502         threads (since these are not started from an executable binary,
 503         nor have a command line), and by
 504         <function>sd_bus_creds_get_audit_session_id()</function> and
 505         <function>sd_bus_creds_get_audit_login_uid()</function> when
 506         the process is not part of an audit session, and
 507         <function>sd_bus_creds_get_tty()</function> if the process has
 508         no controlling TTY.
 509         </para>
 510         </listitem>
 511       </varlistentry>
 512
 513       <varlistentry>
 514         <term><constant>-EINVAL</constant></term>
 515
 516         <listitem><para>Specified pointer parameter is <constant>NULL</constant>.
 517         </para></listitem>
 518       </varlistentry>
 519
 520       <varlistentry>
 521         <term><constant>-ENOMEM</constant></term>
 522
 523         <listitem><para>Memory allocation failed.</para></listitem>
 524       </varlistentry>
 525     </variablelist>
 526   </refsect1>
 527
 528   <xi:include href="libsystemd-pkgconfig.xml" />
 529
 530   <refsect1>
 531     <title>See Also</title>
 532
 533     <para>
 534       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 535       <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 536       <citerefentry><refentrytitle>sd_bus_creds_new_from_pid</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
 537       <citerefentry project='man-pages'><refentrytitle>fork</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
 538       <citerefentry project='man-pages'><refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
 539       <citerefentry project='man-pages'><refentrytitle>credentials</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 540       <citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 541       <citerefentry project='man-pages'><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 542       <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 543     </para>
 544   </refsect1>
 545
 546 </refentry>