# sd_bus_creds_get_pid

## NAME



           sd_bus_creds_get_pid, sd_bus_creds_get_pidfd_dup,
           sd_bus_creds_get_ppid, sd_bus_creds_get_tid, sd_bus_creds_get_uid,
           sd_bus_creds_get_euid, sd_bus_creds_get_suid,
           sd_bus_creds_get_fsuid, sd_bus_creds_get_gid,
           sd_bus_creds_get_egid, sd_bus_creds_get_sgid,
           sd_bus_creds_get_fsgid, sd_bus_creds_get_supplementary_gids,
           sd_bus_creds_get_comm, sd_bus_creds_get_tid_comm,
           sd_bus_creds_get_exe, sd_bus_creds_get_cmdline,
           sd_bus_creds_get_cgroup, sd_bus_creds_get_unit,
           sd_bus_creds_get_slice, sd_bus_creds_get_user_unit,
           sd_bus_creds_get_user_slice, sd_bus_creds_get_session,
           sd_bus_creds_get_owner_uid, sd_bus_creds_has_effective_cap,
           sd_bus_creds_has_permitted_cap, sd_bus_creds_has_inheritable_cap,
           sd_bus_creds_has_bounding_cap, sd_bus_creds_get_selinux_context,
           sd_bus_creds_get_audit_session_id,
           sd_bus_creds_get_audit_login_uid, sd_bus_creds_get_tty,
           sd_bus_creds_get_unique_name, sd_bus_creds_get_well_known_names,
           sd_bus_creds_get_description - Retrieve fields from a credentials
           object
    


## SYNOPSIS



           **#include <systemd/sd-bus.h>**
    
           **int sd_bus_creds_get_pid(sd_bus_creds ***_c_**, pid_t ***_pid_**);**
    
           **int sd_bus_creds_get_pidfd_dup(sd_bus_creds ***_c_**, int ***_ret_fd_**);**
    
           **int sd_bus_creds_get_ppid(sd_bus_creds ***_c_**, pid_t ***_ppid_**);**
    
           **int sd_bus_creds_get_tid(sd_bus_creds ***_c_**, pid_t ***_tid_**);**
    
           **int sd_bus_creds_get_uid(sd_bus_creds ***_c_**, uid_t ***_uid_**);**
    
           **int sd_bus_creds_get_euid(sd_bus_creds ***_c_**, uid_t ***_uid_**);**
    
           **int sd_bus_creds_get_suid(sd_bus_creds ***_c_**, uid_t ***_uid_**);**
    
           **int sd_bus_creds_get_fsuid(sd_bus_creds ***_c_**, uid_t ***_uid_**);**
    
           **int sd_bus_creds_get_gid(sd_bus_creds ***_c_**, gid_t ***_gid_**);**
    
           **int sd_bus_creds_get_egid(sd_bus_creds ***_c_**, gid_t ***_gid_**);**
    
           **int sd_bus_creds_get_sgid(sd_bus_creds ***_c_**, gid_t ***_gid_**);**
    
           **int sd_bus_creds_get_fsgid(sd_bus_creds ***_c_**, gid_t ***_gid_**);**
    
           **int sd_bus_creds_get_supplementary_gids(sd_bus_creds ***_c_**,**
                                                   **const gid_t ****_gids_**);**
    
           **int sd_bus_creds_get_comm(sd_bus_creds ***_c_**, const char ****_comm_**);**
    
           **int sd_bus_creds_get_tid_comm(sd_bus_creds ***_c_**, const char ****_comm_**);**
    
           **int sd_bus_creds_get_exe(sd_bus_creds ***_c_**, const char ****_exe_**);**
    
           **int sd_bus_creds_get_cmdline(sd_bus_creds ***_c_**, char *****_cmdline_**);**
    
           **int sd_bus_creds_get_cgroup(sd_bus_creds ***_c_**, const char ****_cgroup_**);**
    
           **int sd_bus_creds_get_unit(sd_bus_creds ***_c_**, const char ****_unit_**);**
    
           **int sd_bus_creds_get_slice(sd_bus_creds ***_c_**, const char ****_slice_**);**
    
           **int sd_bus_creds_get_user_unit(sd_bus_creds ***_c_**,**
                                          **const char ****_unit_**);**
    
           **int sd_bus_creds_get_user_slice(sd_bus_creds ***_c_**,**
                                           **const char ****_slice_**);**
    
           **int sd_bus_creds_get_session(sd_bus_creds ***_c_**, const char ****_slice_**);**
    
           **int sd_bus_creds_get_owner_uid(sd_bus_creds ***_c_**, uid_t ***_uid_**);**
    
           **int sd_bus_creds_has_effective_cap(sd_bus_creds ***_c_**,**
                                              **int** _capability_**);**
    
           **int sd_bus_creds_has_permitted_cap(sd_bus_creds ***_c_**,**
                                              **int** _capability_**);**
    
           **int sd_bus_creds_has_inheritable_cap(sd_bus_creds ***_c_**,**
                                                **int** _capability_**);**
    
           **int sd_bus_creds_has_bounding_cap(sd_bus_creds ***_c_**,**
                                             **int** _capability_**);**
    
           **int sd_bus_creds_get_selinux_context(sd_bus_creds ***_c_**,**
                                                **const char ****_context_**);**
    
           **int sd_bus_creds_get_audit_session_id(sd_bus_creds ***_c_**,**
                                                 **uint32_t ***_sessionid_**);**
    
           **int sd_bus_creds_get_audit_login_uid(sd_bus_creds ***_c_**,**
                                                **uid_t ***_loginuid_**);**
    
           **int sd_bus_creds_get_tty(sd_bus_creds ***_c_**, const char ****_tty_**);**
    
           **int sd_bus_creds_get_unique_name(sd_bus_creds ***_c_**,**
                                            **const char ****_name_**);**
    
           **int sd_bus_creds_get_well_known_names(sd_bus_creds ***_c_**,**
                                                 **char *****_name_**);**
    
           **int sd_bus_creds_get_description(sd_bus_creds ***_c_**,**
                                            **const char ****_name_**);**
    


## DESCRIPTION



           These functions return credential information from an _sd_bus_creds_
           object. Credential objects may be created with
           sd_bus_creds_new_from_pid(3), in which case they describe the
           credentials of the process identified by the specified PID, with
           sd_bus_get_name_creds(3), in which case they describe the
           credentials of a bus peer identified by the specified bus name,
           with sd_bus_get_owner_creds(3), in which case they describe the
           credentials of the creator of a bus, or with
           sd_bus_message_get_creds(3), in which case they describe the
           credentials of the sender of the message.
    
           Not all credential fields are part of every "sd_bus_creds" object.
           Use sd_bus_creds_get_mask(3) to determine the mask of fields
           available.
    
           **sd_bus_creds_get_pid()** will retrieve the PID (process identifier).
           Similarly, **sd_bus_creds_get_ppid()** will retrieve the parent PID.
           Note that PID 1 has no parent process, in which case -ENXIO is
           returned.
    
           **sd_bus_creds_get_pidfd_dup()** will retrieve the PID file descriptor
           (pidfd), see pidfd_open(2) for details. The file descriptor is
           duplicated and thus must be closed by the caller.
    
           **sd_bus_creds_get_tid()** will retrieve the TID (thread identifier).
    
           **sd_bus_creds_get_uid()** will retrieve the numeric UID (user
           identifier). Similarly, **sd_bus_creds_get_euid()** returns the
           effective UID, **sd_bus_creds_get_suid()** the saved UID and
           **sd_bus_creds_get_fsuid()** the file system UID.
    
           **sd_bus_creds_get_gid()** will retrieve the numeric GID (group
           identifier). Similarly, **sd_bus_creds_get_egid()** returns the
           effective GID, **sd_bus_creds_get_sgid()** the saved GID and
           **sd_bus_creds_get_fsgid()** the file system GID.
    
           **sd_bus_creds_get_supplementary_gids()** will retrieve the
           supplementary GIDs list.
    
           **sd_bus_creds_get_comm()** will retrieve the comm field (truncated
           name of the executable, as stored in /proc/_pid_ /comm).
    
           **sd_bus_creds_get_tid_comm()** will retrieve the comm field of the
           thread (as stored in /proc/_pid_ /task/_tid_ /comm).
    
           **sd_bus_creds_get_exe()** will retrieve the path to the program
           executable (as stored in the /proc/_pid_ /exe link, but with the "
           (deleted)" suffix removed). Note that kernel threads do not have
           an executable path, in which case -ENXIO is returned. Note that
           this property should not be used for more than explanatory
           information, in particular it should not be used for
           security-relevant decisions. That's because the executable might
           have been replaced or removed by the time the value can be
           processed. Moreover, the kernel exports this information in an
           ambiguous way (i.e. a deleted executable cannot be safely
           distinguished from one whose name suffix is " (deleted)").
    
           **sd_bus_creds_get_cmdline()** will retrieve an array of command line
           arguments (as stored in /proc/_pid_ /cmdline). Note that kernel
           threads do not have a command line, in which case -ENXIO is
           returned.
    
           **sd_bus_creds_get_cgroup()** will retrieve the control group path.
           See **Control Groups v2******[1].**sd_bus_creds_get_unit()** will retrieve the systemd unit name (in
           the system instance of systemd) that the process is a part of. See
           systemd.unit(5). For processes that are not part of a unit,
           returns -ENXIO.
    
           **sd_bus_creds_get_user_unit()** will retrieve the systemd unit name
           (in the user instance of systemd) that the process is a part of.
           See systemd.unit(5). For processes that are not part of a user
           unit, returns -ENXIO.
    
           **sd_bus_creds_get_slice()** will retrieve the systemd slice (a unit
           in the system instance of systemd) that the process is a part of.
           See systemd.slice(5). Similarly, **sd_bus_creds_get_user_slice()**
           retrieves the systemd slice of the process, in the user instance
           of systemd.
    
           **sd_bus_creds_get_session()** will retrieve the identifier of the
           login session that the process is a part of. Please note the login
           session may be limited to a stub process or two. User processes
           may instead be started from their systemd user manager, e.g. GUI
           applications started using DBus activation, as well as service
           processes which are shared between multiple logins of the same
           user. For processes that are not part of a session, returns
           -ENXIO.
    
           **sd_bus_creds_get_owner_uid()** will retrieve the numeric UID (user
           identifier) of the user who owns the user unit or login session
           that the process is a part of. See systemd-logind.service(8). For
           processes that are not part of a user unit or session, returns
           -ENXIO.
    
           **sd_bus_creds_has_effective_cap()** will check whether the capability
           specified by _capability_ was set in the effective capabilities
           mask. A positive return value means that it was set, zero means
           that it was not set, and a negative return value indicates an
           error. See capabilities(7) and the _AmbientCapabilities=_ and
           _CapabilityBoundingSet=_ settings in systemd.exec(5).
    
           **sd_bus_creds_has_permitted_cap()** is similar to
           **sd_bus_creds_has_effective_cap()** , but will check the permitted
           capabilities mask.
    
           **sd_bus_creds_has_inheritable_cap()** is similar to
           **sd_bus_creds_has_effective_cap()** , but will check the inheritable
           capabilities mask.
    
           **sd_bus_creds_has_bounding_cap()** is similar to
           **sd_bus_creds_has_effective_cap()** , but will check the bounding
           capabilities mask.
    
           **sd_bus_creds_get_selinux_context()** will retrieve the SELinux
           security context (label) of the process.
    
           **sd_bus_creds_get_audit_session_id()** will retrieve the audit
           session identifier of the process. Returns -ENXIO for processes
           that are not part of an audit session.
    
           **sd_bus_creds_get_audit_login_uid()** will retrieve the audit user
           login identifier (the identifier of the user who is "responsible"
           for the session). Returns -ENXIO for processes that are not part
           of an audit session.
    
           **sd_bus_creds_get_tty()** will retrieve the controlling TTY, without
           the prefixing "/dev/". Returns -ENXIO for processes that have no
           controlling TTY.
    
           **sd_bus_creds_get_unique_name()** will retrieve the D-Bus unique
           name. See **The D-Bus specification******[2].**sd_bus_creds_get_well_known_names()** will retrieve the set of D-Bus
           well-known names. See **The D-Bus specification******[2].**sd_bus_creds_get_description()** will retrieve a descriptive name of
           the bus connection of the peer. This name is useful to discern
           multiple bus connections by the same peer, and may be altered by
           the peer with the sd_bus_set_description(3) call.
    
           All functions that take a _const char**_ parameter will store the
           answer there as an address of a **NUL** -terminated string. It will be
           valid as long as _c_ remains valid, and should not be freed or
           modified by the caller.
    
           All functions that take a _char***_ parameter will store the answer
           there as an address of an array of strings. Each individual string
           is **NUL** -terminated, and the array is **NULL** -terminated as a whole. It
           will be valid as long as _c_ remains valid, and should not be freed
           or modified by the caller.
    


## RETURN VALUE



           On success, these calls return 0 or a positive integer. On
           failure, these calls return a negative errno-style error code.
    
       **Errors**
           Returned errors may indicate the following problems:
    
           **-ENODATA**
               The given field is not available in the credentials object _c_.
    
           **-ENXIO**
               The given field is not specified for the described process or
               peer. This will be returned by **sd_bus_creds_get_unit()** ,
               **sd_bus_creds_get_slice()** , **sd_bus_creds_get_user_unit()** ,
               **sd_bus_creds_get_user_slice()** , and **sd_bus_creds_get_session()**
               if the process is not part of a systemd system unit, systemd
               user unit, systemd slice, or logind session. It will be
               returned by **sd_bus_creds_get_owner_uid()** if the process is not
               part of a systemd user unit or logind session. It will also be
               returned by **sd_bus_creds_get_exe()** and
               **sd_bus_creds_get_cmdline()** for kernel threads (since these are
               not started from an executable binary, nor have a command
               line), and by **sd_bus_creds_get_audit_session_id()** and
               **sd_bus_creds_get_audit_login_uid()** when the process is not
               part of an audit session, and **sd_bus_creds_get_tty()** if the
               process has no controlling TTY.
    
           **-EINVAL**
               Specified pointer parameter is **NULL**.
    
           **-ENOMEM**
               Memory allocation failed.
    


## NOTES



           Functions described here are available as a shared library, which
           can be compiled against and linked to with the
           **libsystemd pkg-config**(1) file.
    
           The code described here uses getenv(3), which is declared to be
           not multi-thread-safe. This means that the code calling the
           functions described here must not call setenv(3) from a parallel
           thread. It is recommended to only do calls to **setenv()** from an
           early phase of the program when no other threads have been
           started.
    


## NOTES



            1. Control Groups v2
               https://docs.kernel.org/admin-guide/cgroup-v2.html
    
            2. The D-Bus specification
               https://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-names-bus
    


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