man/sd_bus_creds_get_pid.xml

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   6   SPDX-License-Identifier: LGPL-2.1+
   7
   8   Copyright © 2014 Zbigniew Jędrzejewski-Szmek
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  10
  11 <refentry id="sd_bus_creds_get_pid" xmlns:xi="http://www.w3.org/2001/XInclude">
  12
  13   <refentryinfo>
  14     <title>sd_bus_creds_get_pid</title>
  15     <productname>systemd</productname>
  16
  17     <authorgroup>
  18       <author>
  19         <contrib>A monkey with a typewriter</contrib>
  20         <firstname>Zbigniew</firstname>
  21         <surname>Jędrzejewski-Szmek</surname>
  22         <email>zbyszek@in.waw.pl</email>
  23       </author>
  24     </authorgroup>
  25   </refentryinfo>
  26
  27   <refmeta>
  28     <refentrytitle>sd_bus_creds_get_pid</refentrytitle>
  29     <manvolnum>3</manvolnum>
  30   </refmeta>
  31
  32   <refnamediv>
  33     <refname>sd_bus_creds_get_pid</refname>
  34     <refname>sd_bus_creds_get_ppid</refname>
  35     <refname>sd_bus_creds_get_tid</refname>
  36     <refname>sd_bus_creds_get_uid</refname>
  37     <refname>sd_bus_creds_get_euid</refname>
  38     <refname>sd_bus_creds_get_suid</refname>
  39     <refname>sd_bus_creds_get_fsuid</refname>
  40     <refname>sd_bus_creds_get_gid</refname>
  41     <refname>sd_bus_creds_get_egid</refname>
  42     <refname>sd_bus_creds_get_sgid</refname>
  43     <refname>sd_bus_creds_get_fsgid</refname>
  44     <refname>sd_bus_creds_get_supplementary_gids</refname>
  45     <refname>sd_bus_creds_get_comm</refname>
  46     <refname>sd_bus_creds_get_tid_comm</refname>
  47     <refname>sd_bus_creds_get_exe</refname>
  48     <refname>sd_bus_creds_get_cmdline</refname>
  49     <refname>sd_bus_creds_get_cgroup</refname>
  50     <refname>sd_bus_creds_get_unit</refname>
  51     <refname>sd_bus_creds_get_slice</refname>
  52     <refname>sd_bus_creds_get_user_unit</refname>
  53     <refname>sd_bus_creds_get_user_slice</refname>
  54     <refname>sd_bus_creds_get_session</refname>
  55     <refname>sd_bus_creds_get_owner_uid</refname>
  56     <refname>sd_bus_creds_has_effective_cap</refname>
  57     <refname>sd_bus_creds_has_permitted_cap</refname>
  58     <refname>sd_bus_creds_has_inheritable_cap</refname>
  59     <refname>sd_bus_creds_has_bounding_cap</refname>
  60     <refname>sd_bus_creds_get_selinux_context</refname>
  61     <refname>sd_bus_creds_get_audit_session_id</refname>
  62     <refname>sd_bus_creds_get_audit_login_uid</refname>
  63     <refname>sd_bus_creds_get_tty</refname>
  64     <refname>sd_bus_creds_get_unique_name</refname>
  65     <refname>sd_bus_creds_get_well_known_names</refname>
  66     <refname>sd_bus_creds_get_description</refname>
  67
  68     <refpurpose>Retrieve fields from a credentials object</refpurpose>
  69   </refnamediv>
  70
  71   <refsynopsisdiv>
  72     <funcsynopsis>
  73       <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
  74
  75       <funcprototype>
  76         <funcdef>int <function>sd_bus_creds_get_pid</function></funcdef>
  77         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
  78         <paramdef>pid_t *<parameter>pid</parameter></paramdef>
  79       </funcprototype>
  80
  81       <funcprototype>
  82         <funcdef>int <function>sd_bus_creds_get_ppid</function></funcdef>
  83         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
  84         <paramdef>pid_t *<parameter>ppid</parameter></paramdef>
  85       </funcprototype>
  86
  87       <funcprototype>
  88         <funcdef>int <function>sd_bus_creds_get_tid</function></funcdef>
  89         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
  90         <paramdef>pid_t *<parameter>tid</parameter></paramdef>
  91       </funcprototype>
  92
  93       <funcprototype>
  94         <funcdef>int <function>sd_bus_creds_get_uid</function></funcdef>
  95         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
  96         <paramdef>uid_t *<parameter>uid</parameter></paramdef>
  97       </funcprototype>
  98
  99       <funcprototype>
 100         <funcdef>int <function>sd_bus_creds_get_euid</function></funcdef>
 101         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 102         <paramdef>uid_t *<parameter>uid</parameter></paramdef>
 103       </funcprototype>
 104
 105       <funcprototype>
 106         <funcdef>int <function>sd_bus_creds_get_suid</function></funcdef>
 107         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 108         <paramdef>uid_t *<parameter>uid</parameter></paramdef>
 109       </funcprototype>
 110
 111       <funcprototype>
 112         <funcdef>int <function>sd_bus_creds_get_fsuid</function></funcdef>
 113         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 114         <paramdef>uid_t *<parameter>uid</parameter></paramdef>
 115       </funcprototype>
 116
 117       <funcprototype>
 118         <funcdef>int <function>sd_bus_creds_get_gid</function></funcdef>
 119         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 120         <paramdef>gid_t *<parameter>gid</parameter></paramdef>
 121       </funcprototype>
 122
 123       <funcprototype>
 124         <funcdef>int <function>sd_bus_creds_get_egid</function></funcdef>
 125         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 126         <paramdef>gid_t *<parameter>gid</parameter></paramdef>
 127       </funcprototype>
 128
 129       <funcprototype>
 130         <funcdef>int <function>sd_bus_creds_get_sgid</function></funcdef>
 131         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 132         <paramdef>gid_t *<parameter>gid</parameter></paramdef>
 133       </funcprototype>
 134
 135       <funcprototype>
 136         <funcdef>int <function>sd_bus_creds_get_fsgid</function></funcdef>
 137         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 138         <paramdef>gid_t *<parameter>gid</parameter></paramdef>
 139       </funcprototype>
 140
 141       <funcprototype>
 142         <funcdef>int <function>sd_bus_creds_get_supplementary_gids</function></funcdef>
 143         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 144         <paramdef>const gid_t **<parameter>gids</parameter></paramdef>
 145       </funcprototype>
 146
 147       <funcprototype>
 148         <funcdef>int <function>sd_bus_creds_get_comm</function></funcdef>
 149         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 150         <paramdef>const char **<parameter>comm</parameter></paramdef>
 151       </funcprototype>
 152
 153       <funcprototype>
 154         <funcdef>int <function>sd_bus_creds_get_tid_comm</function></funcdef>
 155         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 156         <paramdef>const char **<parameter>comm</parameter></paramdef>
 157       </funcprototype>
 158
 159       <funcprototype>
 160         <funcdef>int <function>sd_bus_creds_get_exe</function></funcdef>
 161         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 162         <paramdef>const char **<parameter>exe</parameter></paramdef>
 163       </funcprototype>
 164
 165       <funcprototype>
 166         <funcdef>int <function>sd_bus_creds_get_cmdline</function></funcdef>
 167         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 168         <paramdef>char ***<parameter>cmdline</parameter></paramdef>
 169       </funcprototype>
 170
 171       <funcprototype>
 172         <funcdef>int <function>sd_bus_creds_get_cgroup</function></funcdef>
 173         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 174         <paramdef>const char **<parameter>cgroup</parameter></paramdef>
 175       </funcprototype>
 176
 177       <funcprototype>
 178         <funcdef>int <function>sd_bus_creds_get_unit</function></funcdef>
 179         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 180         <paramdef>const char **<parameter>unit</parameter></paramdef>
 181       </funcprototype>
 182
 183       <funcprototype>
 184         <funcdef>int <function>sd_bus_creds_get_slice</function></funcdef>
 185         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 186         <paramdef>const char **<parameter>slice</parameter></paramdef>
 187       </funcprototype>
 188
 189       <funcprototype>
 190         <funcdef>int <function>sd_bus_creds_get_user_unit</function></funcdef>
 191         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 192         <paramdef>const char **<parameter>unit</parameter></paramdef>
 193       </funcprototype>
 194
 195       <funcprototype>
 196         <funcdef>int <function>sd_bus_creds_get_user_slice</function></funcdef>
 197         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 198         <paramdef>const char **<parameter>slice</parameter></paramdef>
 199       </funcprototype>
 200
 201       <funcprototype>
 202         <funcdef>int <function>sd_bus_creds_get_session</function></funcdef>
 203         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 204         <paramdef>const char **<parameter>slice</parameter></paramdef>
 205       </funcprototype>
 206
 207       <funcprototype>
 208         <funcdef>int <function>sd_bus_creds_get_owner_uid</function></funcdef>
 209         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 210         <paramdef>uid_t *<parameter>uid</parameter></paramdef>
 211       </funcprototype>
 212
 213       <funcprototype>
 214         <funcdef>int <function>sd_bus_creds_has_effective_cap</function></funcdef>
 215         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 216         <paramdef>int <parameter>capability</parameter></paramdef>
 217       </funcprototype>
 218
 219       <funcprototype>
 220         <funcdef>int <function>sd_bus_creds_has_permitted_cap</function></funcdef>
 221         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 222         <paramdef>int <parameter>capability</parameter></paramdef>
 223       </funcprototype>
 224
 225       <funcprototype>
 226         <funcdef>int <function>sd_bus_creds_has_inheritable_cap</function></funcdef>
 227         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 228         <paramdef>int <parameter>capability</parameter></paramdef>
 229       </funcprototype>
 230
 231       <funcprototype>
 232         <funcdef>int <function>sd_bus_creds_has_bounding_cap</function></funcdef>
 233         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 234         <paramdef>int <parameter>capability</parameter></paramdef>
 235       </funcprototype>
 236
 237       <funcprototype>
 238         <funcdef>int <function>sd_bus_creds_get_selinux_context</function></funcdef>
 239         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 240         <paramdef>const char **<parameter>context</parameter></paramdef>
 241       </funcprototype>
 242
 243       <funcprototype>
 244         <funcdef>int <function>sd_bus_creds_get_audit_session_id</function></funcdef>
 245         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 246         <paramdef>uint32_t *<parameter>sessionid</parameter></paramdef>
 247       </funcprototype>
 248
 249       <funcprototype>
 250         <funcdef>int <function>sd_bus_creds_get_audit_login_uid</function></funcdef>
 251         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 252         <paramdef>uid_t *<parameter>loginuid</parameter></paramdef>
 253       </funcprototype>
 254
 255       <funcprototype>
 256         <funcdef>int <function>sd_bus_creds_get_tty</function></funcdef>
 257         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 258         <paramdef>const char **<parameter>tty</parameter></paramdef>
 259       </funcprototype>
 260
 261       <funcprototype>
 262         <funcdef>int <function>sd_bus_creds_get_unique_name</function></funcdef>
 263         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 264         <paramdef>const char **<parameter>name</parameter></paramdef>
 265       </funcprototype>
 266
 267       <funcprototype>
 268         <funcdef>int <function>sd_bus_creds_get_well_known_names</function></funcdef>
 269         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 270         <paramdef>char ***<parameter>name</parameter></paramdef>
 271       </funcprototype>
 272
 273       <funcprototype>
 274         <funcdef>int <function>sd_bus_creds_get_description</function></funcdef>
 275         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 276         <paramdef>const char **<parameter>name</parameter></paramdef>
 277       </funcprototype>
 278
 279     </funcsynopsis>
 280   </refsynopsisdiv>
 281
 282   <refsect1>
 283     <title>Description</title>
 284
 285     <para>These functions return credential information from an
 286     <parameter>sd_bus_creds</parameter> object. Credential objects may
 287     be created with
 288     <citerefentry><refentrytitle>sd_bus_creds_new_from_pid</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 289     in which case they describe the credentials of the process
 290     identified by the specified PID, with
 291     <citerefentry><refentrytitle>sd_bus_get_name_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 292     in which case they describe the credentials of a bus peer
 293     identified by the specified bus name, with
 294     <citerefentry><refentrytitle>sd_bus_get_owner_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 295     in which case they describe the credentials of the creator of a
 296     bus, or with
 297     <citerefentry><refentrytitle>sd_bus_message_get_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 298     in which case they describe the credentials of the sender of the
 299     message.</para>
 300
 301     <para>Not all credential fields are part of every
 302     <literal>sd_bus_creds</literal> object. Use
 303     <citerefentry><refentrytitle>sd_bus_creds_get_mask</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 304     to determine the mask of fields available.</para>
 305
 306     <para><function>sd_bus_creds_get_pid()</function> will retrieve
 307     the PID (process identifier). Similarly,
 308     <function>sd_bus_creds_get_ppid()</function> will retrieve the
 309     parent PID. Note that PID 1 has no parent process, in which case
 310     -ENXIO is returned.</para>
 311
 312     <para><function>sd_bus_creds_get_tid()</function> will retrieve the
 313     TID (thread identifier).</para>
 314
 315     <para><function>sd_bus_creds_get_uid()</function> will retrieve
 316     the numeric UID (user identifier). Similarly,
 317     <function>sd_bus_creds_get_euid()</function> returns the effective
 318     UID, <function>sd_bus_creds_get_suid()</function> the saved UID
 319     and <function>sd_bus_creds_get_fsuid()</function> the file system
 320     UID.</para>
 321
 322     <para><function>sd_bus_creds_get_gid()</function> will retrieve the
 323     numeric GID (group identifier). Similarly,
 324     <function>sd_bus_creds_get_egid()</function> returns the effective
 325     GID, <function>sd_bus_creds_get_sgid()</function> the saved GID
 326     and <function>sd_bus_creds_get_fsgid()</function> the file system
 327     GID.</para>
 328
 329     <para><function>sd_bus_creds_get_supplementary_gids()</function>
 330     will retrieve the supplementary GIDs list.</para>
 331
 332     <para><function>sd_bus_creds_get_comm()</function> will retrieve the
 333     comm field (truncated name of the executable, as stored in
 334     <filename>/proc/<replaceable>pid</replaceable>/comm</filename>).
 335     </para>
 336
 337     <para><function>sd_bus_creds_get_tid_comm()</function> will retrieve
 338     the comm field of the thread (as stored in
 339     <filename>/proc/<replaceable>pid</replaceable>/task/<replaceable>tid</replaceable>/comm</filename>).
 340     </para>
 341
 342     <para><function>sd_bus_creds_get_exe()</function> will retrieve
 343     the path to the program executable (as stored in the
 344     <filename>/proc/<replaceable>pid</replaceable>/exe</filename>
 345     link, but with the <literal> (deleted)</literal> suffix removed). Note
 346     that kernel threads do not have an executable path, in which case
 347     -ENXIO is returned.</para>
 348
 349     <para><function>sd_bus_creds_get_cmdline()</function> will
 350     retrieve an array of command line arguments (as stored in
 351     <filename>/proc/<replaceable>pid</replaceable>/cmdline</filename>). Note
 352     that kernel threads do not have a command line, in which case
 353     -ENXIO is returned.</para>
 354
 355     <para><function>sd_bus_creds_get_cgroup()</function> will retrieve
 356     the control group path. See <ulink
 357     url="https://www.kernel.org/doc/Documentation/cgroup-v1/cgroups.txt">cgroups.txt</ulink>.
 358     </para>
 359
 360     <para><function>sd_bus_creds_get_unit()</function> will retrieve
 361     the systemd unit name (in the system instance of systemd) that the
 362     process is a part of. See
 363     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. For
 364     processes that are not part of a unit, returns -ENXIO.
 365     </para>
 366
 367     <para><function>sd_bus_creds_get_user_unit()</function> will
 368     retrieve the systemd unit name (in the user instance of systemd)
 369     that the process is a part of. See
 370     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. For
 371     processes that are not part of a user unit, returns -ENXIO.
 372     </para>
 373
 374     <para><function>sd_bus_creds_get_slice()</function> will retrieve
 375     the systemd slice (a unit in the system instance of systemd) that
 376     the process is a part of. See
 377     <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Similarly,
 378     <function>sd_bus_creds_get_user_slice()</function> retrieves the
 379     systemd slice of the process, in the user instance of systemd.
 380     </para>
 381
 382     <para><function>sd_bus_creds_get_session()</function> will
 383     retrieve the identifier of the login session that the process is
 384     a part of. Please note the login session may be limited to a stub
 385     process or two.  User processes may instead be started from their
 386     systemd user manager, e.g. GUI applications started using DBus
 387     activation, as well as service processes which are shared between
 388     multiple logins of the same user. For processes that are not part
 389     of a session, returns -ENXIO.</para>
 390
 391     <para><function>sd_bus_creds_get_owner_uid()</function> will
 392     retrieve the numeric UID (user identifier) of the user who owns
 393     the user unit or login session that the process is a part of. See
 394     <citerefentry><refentrytitle>systemd-logind.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
 395     For processes that are not part of a user unit or session, returns
 396     -ENXIO.
 397     </para>
 398
 399     <para><function>sd_bus_creds_has_effective_cap()</function> will check whether the capability specified by
 400     <parameter>capability</parameter> was set in the effective capabilities mask. A positive return value means that it
 401     was set, zero means that it was not set, and a negative return value indicates an error. See <citerefentry
 402     project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry> and the
 403     <varname>AmbientCapabilities=</varname> and <varname>CapabilityBoundingSet=</varname> settings in
 404     <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 405     </para>
 406
 407     <para><function>sd_bus_creds_has_permitted_cap()</function> is
 408     similar to <function>sd_bus_creds_has_effective_cap()</function>,
 409     but will check the permitted capabilities mask.</para>
 410
 411     <para><function>sd_bus_creds_has_inheritable_cap()</function> is
 412     similar to <function>sd_bus_creds_has_effective_cap()</function>,
 413     but will check the inheritable capabilities mask.</para>
 414
 415     <para><function>sd_bus_creds_has_bounding_cap()</function> is
 416     similar to <function>sd_bus_creds_has_effective_cap()</function>,
 417     but will check the bounding capabilities mask.</para>
 418
 419     <para><function>sd_bus_creds_get_selinux_context()</function> will
 420     retrieve the SELinux security context (label) of the process.</para>
 421
 422     <para><function>sd_bus_creds_get_audit_session_id()</function>
 423     will retrieve the audit session identifier of the process. Returns
 424     -ENXIO for processes that are not part of an audit session.</para>
 425
 426     <para><function>sd_bus_creds_get_audit_login_uid()</function> will
 427     retrieve the audit user login identifier (the identifier of the
 428     user who is "responsible" for the session). Returns -ENXIO for
 429     processes that are not part of an audit session.</para>
 430
 431     <para><function>sd_bus_creds_get_tty()</function> will retrieve
 432     the controlling TTY, without the prefixing "/dev/". Returns -ENXIO
 433     for processes that have no controlling TTY.</para>
 434
 435     <para><function>sd_bus_creds_get_unique_name()</function> will
 436     retrieve the D-Bus unique name. See <ulink
 437     url="http://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-names-bus">The
 438     D-Bus specification</ulink>.</para>
 439
 440     <para><function>sd_bus_creds_get_well_known_names()</function> will
 441     retrieve the set of D-Bus well-known names. See <ulink
 442     url="http://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-names-bus">The
 443     D-Bus specification</ulink>.</para>
 444
 445     <para><function>sd_bus_creds_get_description()</function> will
 446     retrieve a descriptive name of the bus connection of the
 447     peer. This name is useful to discern multiple bus connections by
 448     the same peer, and may be altered by the peer with the
 449     <citerefentry><refentrytitle>sd_bus_set_description</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 450     call.</para>
 451
 452     <para>All functions that take a <parameter>const
 453     char**</parameter> parameter will store the answer there as an
 454     address of a NUL-terminated string. It will be valid as long as
 455     <parameter>c</parameter> remains valid, and should not be freed or
 456     modified by the caller.</para>
 457
 458     <para>All functions that take a <parameter>char***</parameter>
 459     parameter will store the answer there as an address of an array
 460     of strings. Each individual string is NUL-terminated, and the
 461     array is NULL-terminated as a whole. It will be valid as long as
 462     <parameter>c</parameter> remains valid, and should not be freed or
 463     modified by the caller.</para>
 464   </refsect1>
 465
 466   <refsect1>
 467     <title>Return Value</title>
 468
 469     <para>On success, these calls return 0 or a positive integer. On
 470     failure, these calls return a negative errno-style error code.
 471     </para>
 472   </refsect1>
 473
 474   <refsect1>
 475     <title>Errors</title>
 476
 477     <para>Returned errors may indicate the following problems:</para>
 478
 479     <variablelist>
 480       <varlistentry>
 481         <term><constant>-ENODATA</constant></term>
 482
 483         <listitem><para>The given field is not available in the
 484         credentials object <parameter>c</parameter>.</para>
 485         </listitem>
 486       </varlistentry>
 487
 488       <varlistentry>
 489         <term><constant>-ENXIO</constant></term>
 490
 491         <listitem><para>The given field is not specified for the described
 492         process or peer. This will be returned by
 493         <function>sd_bus_creds_get_unit()</function>,
 494         <function>sd_bus_creds_get_slice()</function>,
 495         <function>sd_bus_creds_get_user_unit()</function>,
 496         <function>sd_bus_creds_get_user_slice()</function>, and
 497         <function>sd_bus_creds_get_session()</function> if the process is
 498         not part of a systemd system unit, systemd user unit, systemd
 499         slice, or logind session. It will be returned by
 500         <function>sd_bus_creds_get_owner_uid()</function> if the process is
 501         not part of a systemd user unit or logind session. It will also be
 502         returned by <function>sd_bus_creds_get_exe()</function> and
 503         <function>sd_bus_creds_get_cmdline()</function> for kernel
 504         threads (since these are not started from an executable binary,
 505         nor have a command line), and by
 506         <function>sd_bus_creds_get_audit_session_id()</function> and
 507         <function>sd_bus_creds_get_audit_login_uid()</function> when
 508         the process is not part of an audit session, and
 509         <function>sd_bus_creds_get_tty()</function> if the process has
 510         no controlling TTY.
 511         </para>
 512         </listitem>
 513       </varlistentry>
 514
 515       <varlistentry>
 516         <term><constant>-EINVAL</constant></term>
 517
 518         <listitem><para>Specified pointer parameter is <constant>NULL</constant>.
 519         </para></listitem>
 520       </varlistentry>
 521
 522       <varlistentry>
 523         <term><constant>-ENOMEM</constant></term>
 524
 525         <listitem><para>Memory allocation failed.</para></listitem>
 526       </varlistentry>
 527     </variablelist>
 528   </refsect1>
 529
 530   <xi:include href="libsystemd-pkgconfig.xml" />
 531
 532   <refsect1>
 533     <title>See Also</title>
 534
 535     <para>
 536       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 537       <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 538       <citerefentry><refentrytitle>sd_bus_creds_new_from_pid</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
 539       <citerefentry project='man-pages'><refentrytitle>fork</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
 540       <citerefentry project='man-pages'><refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
 541       <citerefentry project='man-pages'><refentrytitle>credentials</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 542       <citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 543       <citerefentry project='man-pages'><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 544       <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 545     </para>
 546   </refsect1>
 547
 548 </refentry>