man/sd_bus_creds_get_pid.xml

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   8 Copyright 2014 Zbigniew Jędrzejewski-Szmek
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  23
  24 <refentry id="sd_bus_creds_get_pid" conditional="ENABLE_KDBUS">
  25
  26   <refentryinfo>
  27     <title>sd_bus_creds_get_pid</title>
  28     <productname>systemd</productname>
  29
  30     <authorgroup>
  31       <author>
  32         <contrib>A monkey with a typewriter</contrib>
  33         <firstname>Zbigniew</firstname>
  34         <surname>Jędrzejewski-Szmek</surname>
  35         <email>zbyszek@in.waw.pl</email>
  36       </author>
  37     </authorgroup>
  38   </refentryinfo>
  39
  40   <refmeta>
  41     <refentrytitle>sd_bus_creds_get_pid</refentrytitle>
  42     <manvolnum>3</manvolnum>
  43   </refmeta>
  44
  45   <refnamediv>
  46     <refname>sd_bus_creds_get_pid</refname>
  47     <refname>sd_bus_creds_get_pid_starttime</refname>
  48     <refname>sd_bus_creds_get_tid</refname>
  49     <refname>sd_bus_creds_get_uid</refname>
  50     <refname>sd_bus_creds_get_gid</refname>
  51     <refname>sd_bus_creds_get_comm</refname>
  52     <refname>sd_bus_creds_get_tid_comm</refname>
  53     <refname>sd_bus_creds_get_exe</refname>
  54     <refname>sd_bus_creds_get_cmdline</refname>
  55     <refname>sd_bus_creds_get_cgroup</refname>
  56     <refname>sd_bus_creds_get_unit</refname>
  57     <refname>sd_bus_creds_get_user_unit</refname>
  58     <refname>sd_bus_creds_get_slice</refname>
  59     <refname>sd_bus_creds_get_session</refname>
  60     <refname>sd_bus_creds_get_owner_uid</refname>
  61     <refname>sd_bus_creds_has_effective_cap</refname>
  62     <refname>sd_bus_creds_has_permitted_cap</refname>
  63     <refname>sd_bus_creds_has_inheritable_cap</refname>
  64     <refname>sd_bus_creds_has_bounding_cap</refname>
  65     <refname>sd_bus_creds_get_selinux_context</refname>
  66     <refname>sd_bus_creds_get_audit_session_id</refname>
  67     <refname>sd_bus_creds_get_audit_login_uid</refname>
  68     <refname>sd_bus_creds_get_unique_name</refname>
  69     <refname>sd_bus_creds_get_well_known_names</refname>
  70
  71     <refpurpose>Retrieve fields from a credentials object</refpurpose>
  72   </refnamediv>
  73
  74   <refsynopsisdiv>
  75     <funcsynopsis>
  76       <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
  77
  78       <funcprototype>
  79         <funcdef>int <function>sd_bus_creds_get_pid</function></funcdef>
  80         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
  81         <paramdef>pid_t *<parameter>pid</parameter></paramdef>
  82       </funcprototype>
  83
  84       <funcprototype>
  85         <funcdef>int <function>sd_bus_creds_get_pid_starttime</function></funcdef>
  86         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
  87         <paramdef>uint64_t *<parameter>usec</parameter></paramdef>
  88       </funcprototype>
  89
  90       <funcprototype>
  91         <funcdef>int <function>sd_bus_creds_get_tid</function></funcdef>
  92         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
  93         <paramdef>pid_t *<parameter>tid</parameter></paramdef>
  94       </funcprototype>
  95
  96       <funcprototype>
  97         <funcdef>int <function>sd_bus_creds_get_pid</function></funcdef>
  98         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
  99         <paramdef>uid_t *<parameter>uid</parameter></paramdef>
 100       </funcprototype>
 101
 102       <funcprototype>
 103         <funcdef>int <function>sd_bus_creds_get_gid</function></funcdef>
 104         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 105         <paramdef>gid_t *<parameter>gid</parameter></paramdef>
 106       </funcprototype>
 107
 108       <funcprototype>
 109         <funcdef>int <function>sd_bus_creds_get_comm</function></funcdef>
 110         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 111         <paramdef>const char **<parameter>comm</parameter></paramdef>
 112       </funcprototype>
 113
 114       <funcprototype>
 115         <funcdef>int <function>sd_bus_creds_get_tid_comm</function></funcdef>
 116         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 117         <paramdef>const char **<parameter>comm</parameter></paramdef>
 118       </funcprototype>
 119
 120       <funcprototype>
 121         <funcdef>int <function>sd_bus_creds_get_exe</function></funcdef>
 122         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 123         <paramdef>const char **<parameter>exe</parameter></paramdef>
 124       </funcprototype>
 125
 126       <funcprototype>
 127         <funcdef>int <function>sd_bus_creds_get_cmdline</function></funcdef>
 128         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 129         <paramdef>char ***<parameter>cmdline</parameter></paramdef>
 130       </funcprototype>
 131
 132       <funcprototype>
 133         <funcdef>int <function>sd_bus_creds_get_cgroup</function></funcdef>
 134         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 135         <paramdef>const char **<parameter>cgroup</parameter></paramdef>
 136       </funcprototype>
 137
 138       <funcprototype>
 139         <funcdef>int <function>sd_bus_creds_get_unit</function></funcdef>
 140         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 141         <paramdef>const char **<parameter>unit</parameter></paramdef>
 142       </funcprototype>
 143
 144       <funcprototype>
 145         <funcdef>int <function>sd_bus_creds_get_user_unit</function></funcdef>
 146         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 147         <paramdef>const char **<parameter>unit</parameter></paramdef>
 148       </funcprototype>
 149
 150       <funcprototype>
 151         <funcdef>int <function>sd_bus_creds_get_slice</function></funcdef>
 152         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 153         <paramdef>const char **<parameter>slice</parameter></paramdef>
 154       </funcprototype>
 155
 156       <funcprototype>
 157         <funcdef>int <function>sd_bus_creds_get_session</function></funcdef>
 158         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 159         <paramdef>const char **<parameter>slice</parameter></paramdef>
 160       </funcprototype>
 161
 162       <funcprototype>
 163         <funcdef>int <function>sd_bus_creds_get_owner_uid</function></funcdef>
 164         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 165         <paramdef>uid_t *<parameter>uid</parameter></paramdef>
 166       </funcprototype>
 167
 168       <funcprototype>
 169         <funcdef>int <function>sd_bus_creds_has_effective_cap</function></funcdef>
 170         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 171         <paramdef>int <parameter>capability</parameter></paramdef>
 172       </funcprototype>
 173
 174       <funcprototype>
 175         <funcdef>int <function>sd_bus_creds_has_permitted_cap</function></funcdef>
 176         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 177         <paramdef>int <parameter>capability</parameter></paramdef>
 178       </funcprototype>
 179
 180       <funcprototype>
 181         <funcdef>int <function>sd_bus_creds_has_inheritable_cap</function></funcdef>
 182         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 183         <paramdef>int <parameter>capability</parameter></paramdef>
 184       </funcprototype>
 185
 186       <funcprototype>
 187         <funcdef>int <function>sd_bus_creds_has_bounding_cap</function></funcdef>
 188         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 189         <paramdef>int <parameter>capability</parameter></paramdef>
 190       </funcprototype>
 191
 192       <funcprototype>
 193         <funcdef>int <function>sd_bus_creds_get_selinux_context</function></funcdef>
 194         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 195         <paramdef>const char **<parameter>context</parameter></paramdef>
 196       </funcprototype>
 197
 198       <funcprototype>
 199         <funcdef>int <function>sd_bus_creds_get_audit_session_id</function></funcdef>
 200         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 201         <paramdef>uint32_t *<parameter>sessionid</parameter></paramdef>
 202       </funcprototype>
 203
 204       <funcprototype>
 205         <funcdef>int <function>sd_bus_creds_get_audit_login_uid</function></funcdef>
 206         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 207         <paramdef>uid_t *<parameter>loginuid</parameter></paramdef>
 208       </funcprototype>
 209
 210       <funcprototype>
 211         <funcdef>int <function>sd_bus_creds_get_unique_name</function></funcdef>
 212         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 213         <paramdef>const char **<parameter>name</parameter></paramdef>
 214       </funcprototype>
 215
 216       <funcprototype>
 217         <funcdef>int <function>sd_bus_creds_get_well_known_names</function></funcdef>
 218         <paramdef>sd_bus_creds *<parameter>c</parameter></paramdef>
 219         <paramdef>char ***<parameter>name</parameter></paramdef>
 220       </funcprototype>
 221
 222     </funcsynopsis>
 223   </refsynopsisdiv>
 224
 225   <refsect1>
 226     <title>Description</title>
 227
 228     <para>These functions return information from an
 229     <parameter>sd_bus_creds</parameter> object. It may be created with
 230     <citerefentry><refentrytitle>sd_bus_creds_new_from_pid</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 231     in which case it will describe the specified process, or it may be
 232     created by
 233     <citerefentry><refentrytitle>sd_bus_get_peer_creds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 234     in which case it will describe the process at the other endpoint
 235     of a connection.
 236     </para>
 237
 238     <para><function>sd_bus_creds_get_pid</function> will retrieve the
 239     PID (process identifier).</para>
 240
 241     <para><function>sd_bus_creds_get_pid_starttime</function> will
 242     retrieve the time since the start of the epoch in microseconds
 243     since the process was started.</para>
 244
 245     <para><function>sd_bus_creds_get_tid</function> will retrieve the
 246     TID (thread identifier).</para>
 247
 248     <para><function>sd_bus_creds_get_uid</function> will retrieve the
 249     numeric UID (user identifier).</para>
 250
 251     <para><function>sd_bus_creds_get_gid</function> will retrieve the
 252     numeric GID (group identifier).</para>
 253
 254     <para><function>sd_bus_creds_get_comm</function> will retrieve the
 255     comm field (truncated name of the executable, as stored in
 256     <filename>/proc/<replaceable>pid</replaceable>/comm</filename>).
 257     </para>
 258
 259     <para><function>sd_bus_creds_get_tid_comm</function> will retrieve
 260     the comm field of the thread (as stored in
 261     <filename>/proc/<replaceable>pid</replaceable>/task/<replaceable>tid</replaceable>/comm</filename>).
 262     </para>
 263
 264     <para><function>sd_bus_creds_get_exe</function> will retrieve the
 265     path to the program (as stored in the
 266     <filename>/proc/<replaceable>pid</replaceable>/exe</filename>
 267     link, but with <literal> (deleted)</literal> suffix removed).
 268     </para>
 269
 270     <para><function>sd_bus_creds_get_cmdline</function> will retrieve
 271     an array of command-line arguments (as stored in
 272     <filename>/proc/<replaceable>pid</replaceable>/cmdline</filename>).
 273     </para>
 274
 275     <para><function>sd_bus_creds_get_cgroup</function> will retrieve
 276     the cgroup path. See <ulink
 277     url="https://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink>.
 278     </para>
 279
 280     <para><function>sd_bus_creds_get_unit</function> will retrieve the
 281     systemd unit name (in the system instance of systemd) that the
 282     process is part of. See
 283     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 284     </para>
 285
 286     <para><function>sd_bus_creds_get_user_unit</function> will
 287     retrieve the systemd unit name (in the user instance of systemd)
 288     that the process is part of. See
 289     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 290     </para>
 291
 292     <para><function>sd_bus_creds_get_slice</function> will retrieve
 293     the systemd slice (a unit in the system instance of systemd) that
 294     the process is part of. See
 295     <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 296     </para>
 297
 298     <para><function>sd_bus_creds_get_session</function> will retrieve
 299     the logind session that the process is part of. See
 300     <citerefentry><refentrytitle>systemd-logind.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
 301     </para>
 302
 303     <para><function>sd_bus_creds_get_owner_uid</function> will retrieve
 304     the numeric UID (user identifier) of the user who owns the slice
 305     that the process is part of. See
 306     <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 307     <!-- and
 308     <citerefentry><refentrytitle>systemd-user-sessions.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> -->.
 309     </para>
 310
 311     <para><function>sd_bus_creds_has_effective_cap</function> will
 312     check whether the capability specified by
 313     <parameter>capability</parameter> was set in the effective
 314     capabilities mask. A positive return value means that is was
 315     set, zero means that it was not set, and a negative return
 316     value signifies an error. See
 317     <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 318     and <varname>Capabilities=</varname> and
 319     <varname>CapabilityBoundingSet=</varname> settings in
 320     <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 321     </para>
 322
 323     <para><function>sd_bus_creds_has_permitted_cap</function> is
 324     similar to <function>sd_bus_creds_has_effective_cap</function>,
 325     but will check the permitted capabilities mask.</para>
 326
 327     <para><function>sd_bus_creds_has_inheritable_cap</function> is
 328     similar to <function>sd_bus_creds_has_effective_cap</function>,
 329     but will check the inheritable capabilities mask.</para>
 330
 331     <para><function>sd_bus_creds_has_bounding_cap</function> is
 332     similar to <function>sd_bus_creds_has_effective_cap</function>,
 333     but will check the bounding capabilities mask.</para>
 334
 335     <para><function>sd_bus_creds_get_selinux_context</function> will
 336     retrieve the SELinux security context (label) of the process.</para>
 337
 338     <para><function>sd_bus_creds_get_audit_session_id</function> will
 339     retrieve the audit session identifier of the process.</para>
 340
 341     <para><function>sd_bus_creds_get_audit_login_uid</function> will
 342     retrieve the audit user login identifier (the identifier of the
 343     user who is "responsible" for the session).</para>
 344
 345     <para><function>sd_bus_creds_get_unique_name</function> will
 346     retrieve the D-Bus unique name. See <ulink
 347     url="http://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-names-bus">The
 348     D-Bus specification</ulink>.</para>
 349
 350     <para><function>sd_bus_creds_get_well_known_names</function> will
 351     retrieve the set of D-Bus well-known names. See <ulink
 352     url="http://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-names-bus">The
 353     D-Bus specification</ulink>.</para>
 354
 355     <para>All functions that take a <parameter>const
 356     char**</parameter> parameter will store the answer there as an
 357     address of a NUL-terminated string. It will be valid as long as
 358     <parameter>c</parameter> remains valid, and should not be freed or
 359     modified by the caller.</para>
 360
 361     <para>All functions that take a <parameter>char***</parameter>
 362     parameter will store the answer there as an address of a an array
 363     of strings. Each invidividual string is NUL-terminated, and the
 364     array is NULL-terminated as a whole. It will be valid as long as
 365     <parameter>c</parameter> remains valid, and should not be freed or
 366     modified by the caller.</para>
 367   </refsect1>
 368
 369   <refsect1>
 370     <title>Return Value</title>
 371
 372     <para>On success, these calls return 0 or a positive integer. On
 373     failure, these calls return a negative errno-style error code.
 374     </para>
 375   </refsect1>
 376
 377   <refsect1>
 378     <title>Errors</title>
 379
 380     <para>Returned errors may indicate the following problems:</para>
 381
 382     <variablelist>
 383       <varlistentry>
 384         <term><varname>-ENODATA</varname></term>
 385
 386         <listitem><para>Given field is not available in
 387         <parameter>c</parameter>.</para>
 388         </listitem>
 389       </varlistentry>
 390
 391       <varlistentry>
 392         <term><varname>-ENOENT</varname></term>
 393
 394         <listitem><para>Given field is not specified for the sender.
 395         This will be returned by <function>sd_bus_get_unit</function>,
 396         <function>sd_bus_get_user_unit</function>,
 397         <function>sd_bus_get_slice</function>,
 398         <function>sd_bus_get_session</function>, and
 399         <function>sd_bus_get_owner_uid</function> if the sender is not
 400         part of a systemd system unit, systemd user unit, systemd
 401         slice, logind session, or a systemd user session.</para>
 402         </listitem>
 403       </varlistentry>
 404
 405       <varlistentry>
 406         <term><varname>-ENXIO</varname></term>
 407
 408         <listitem><para>An error occured in parsing cgroup paths.
 409         <filename>libsystemd</filename> might be out of sync with
 410         the running systemd version.</para></listitem>
 411       </varlistentry>
 412
 413       <varlistentry>
 414         <term><varname>-EINVAL</varname></term>
 415
 416         <listitem><para>Specified pointer parameter is <constant>NULL</constant>.
 417         </para></listitem>
 418       </varlistentry>
 419
 420       <varlistentry>
 421         <term><varname>-ENOMEM</varname></term>
 422
 423         <listitem><para>Memory allocation failed.</para></listitem>
 424       </varlistentry>
 425     </variablelist>
 426   </refsect1>
 427
 428   <refsect1>
 429     <title>Notes</title>
 430
 431     <para><function>sd_bus_open_user()</function> and other functions
 432     described here are available as a shared library, which can be
 433     compiled and linked to with the
 434     <constant>libsystemd</constant> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 435     file.</para>
 436   </refsect1>
 437
 438   <refsect1>
 439     <title>See Also</title>
 440
 441     <para>
 442       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 443       <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 444       <citerefentry><refentrytitle>credentials</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 445       <citerefentry><refentrytitle>fork</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
 446       <citerefentry><refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
 447       <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 448       <citerefentry><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 449       <citerefentry><refentrytitle>systemd.journald-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 450     </para>
 451   </refsect1>
 452
 453 </refentry>