sd_pid_get_owner_uid(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | SEE ALSO | COLOPHON

SD_PID_GET_OWNER_UID(3)     sd_pid_get_owner_uid     SD_PID_GET_OWNER_UID(3)

NAME         top

       sd_pid_get_owner_uid, sd_pid_get_session, sd_pid_get_user_unit,
       sd_pid_get_unit, sd_pid_get_machine_name, sd_pid_get_slice,
       sd_pid_get_user_slice, sd_pid_get_cgroup, sd_peer_get_owner_uid,
       sd_peer_get_session, sd_peer_get_user_unit, sd_peer_get_unit,
       sd_peer_get_machine_name, sd_peer_get_slice, sd_peer_get_user_slice,
       sd_peer_get_cgroup - Determine the owner uid of the user unit or
       session, or the session, user unit, system unit, container/VM or
       slice that a specific PID or socket peer belongs to.

SYNOPSIS         top

       #include <systemd/sd-login.h>

       int sd_pid_get_owner_uid(pid_t pid, uid_t *uid);

       int sd_pid_get_session(pid_t pid, char **session);

       int sd_pid_get_user_unit(pid_t pid, char **unit);

       int sd_pid_get_unit(pid_t pid, char **unit);

       int sd_pid_get_machine_name(pid_t pid, char **name);

       int sd_pid_get_slice(pid_t pid, char **slice);

       int sd_pid_get_user_slice(pid_t pid, char **slice);

       int sd_pid_get_cgroup(pid_t pid, char **cgroup);

       int sd_peer_get_owner_uid(int fd, uid_t *uid);

       int sd_peer_get_session(int fd, char **session);

       int sd_peer_get_user_unit(int fd, char **unit);

       int sd_peer_get_unit(int fd, char **unit);

       int sd_peer_get_machine_name(int fd, char **name);

       int sd_peer_get_slice(int fd, char **slice);

       int sd_peer_get_user_slice(int fd, char **slice);

       int sd_peer_get_cgroup(int fd, char **cgroup);

DESCRIPTION         top

       sd_pid_get_owner_uid() may be used to determine the Unix UID (user
       identifier) which owns the login session or systemd user unit of a
       process identified by the specified PID. For processes which are not
       part of a login session and not managed by a user manager, this
       function will fail with -ENODATA.

       sd_pid_get_session() may be used to determine the login session
       identifier of a process identified by the specified process
       identifier. The session identifier is a short string, suitable for
       usage in file system paths. 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 which
       are not part of a login session, this function will fail with
       -ENODATA. The returned string needs to be freed with the libc free(3)
       call after use.

       sd_pid_get_user_unit() may be used to determine the systemd user unit
       (i.e. user service or scope unit) identifier of a process identified
       by the specified PID. The unit name is a short string, suitable for
       usage in file system paths. For processes which are not managed by a
       user manager, this function will fail with -ENODATA. The returned
       string needs to be freed with the libc free(3) call after use.

       sd_pid_get_unit() may be used to determine the systemd system unit
       (i.e. system service or scope unit) identifier of a process
       identified by the specified PID. The unit name is a short string,
       suitable for usage in file system paths. Note that not all processes
       are part of a system unit/service. For processes not being part of a
       systemd system unit, this function will fail with -ENODATA. (More
       specifically, this call will not work for kernel threads.) The
       returned string needs to be freed with the libc free(3) call after
       use.

       sd_pid_get_machine_name() may be used to determine the name of the VM
       or container is a member of. The machine name is a short string,
       suitable for usage in file system paths. The returned string needs to
       be freed with the libc free(3) call after use. For processes not part
       of a VM or container, this function fails with -ENODATA.

       sd_pid_get_slice() may be used to determine the slice unit the
       process is a member of. See systemd.slice(5) for details about
       slices. The returned string needs to be freed with the libc free(3)
       call after use.

       Similarly, sd_pid_get_user_slice() returns the user slice (as managed
       by the user's systemd instance) of a process.

       sd_pid_get_cgroup() returns the control group path of the specified
       process, relative to the root of the hierarchy. Returns the path
       without trailing slash, except for processes located in the root
       control group, where "/" is returned. To find the actual control
       group path in the file system, the returned path needs to be prefixed
       with /sys/fs/cgroup/ (if the unified control group setup is used), or
       /sys/fs/cgroup/HIERARCHY/ (if the legacy multi-hierarchy control
       group setup is used).

       If the pid parameter of any of these functions is passed as 0, the
       operation is executed for the calling process.

       The sd_peer_get_owner_uid(), sd_peer_get_session(),
       sd_peer_get_user_unit(), sd_peer_get_unit(),
       sd_peer_get_machine_name(), sd_peer_get_slice(),
       sd_peer_get_user_slice() and sd_peer_get_cgroup() calls operate
       similar to their PID counterparts, but operate on a connected AF_UNIX
       socket and retrieve information about the connected peer process.
       Note that these fields are retrieved via /proc, and hence are not
       suitable for authorization purposes, as they are subject to races.

RETURN VALUE         top

       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:

       -ESRCH
           The specified PID does not refer to a running process.

       -EBADF
           The specified socket file descriptor was invalid.

       -ENODATA
           The given field is not specified for the described process or
           peer.

       -EINVAL
           An input parameter was invalid (out of range, or NULL, where that
           is not accepted).

       -ENOMEM
           Memory allocation failed.

NOTES         top

       These APIs are implemented as a shared library, which can be compiled
       and linked to with the libsystemd pkg-config(1) file.

       Note that the login session identifier as returned by
       sd_pid_get_session() is completely unrelated to the process session
       identifier as returned by getsid(2).

SEE ALSO         top

       systemd(1), sd-login(3), sd_session_is_active(3), getsid(2),
       systemd.slice(5), systemd-machined.service(8)

COLOPHON         top

       This page is part of the systemd (systemd system and service manager)
       project.  Information about the project can be found at 
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have a bug
       report for this manual page, see
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.  This
       page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2020-06-09.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-06-09.)  If you discover any rendering problems in
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       of the original manual page), send a mail to man-pages@man7.org

systemd 245                                          SD_PID_GET_OWNER_UID(3)

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