1SD_PID_GET_OWNER_UID(3) sd_pid_get_owner_uid SD_PID_GET_OWNER_UID(3)
2
6 sd_pid_get_owner_uid, sd_pid_get_session, sd_pid_get_user_unit,
7 sd_pid_get_unit, sd_pid_get_machine_name, sd_pid_get_slice,
8 sd_pid_get_user_slice, sd_pid_get_cgroup, sd_pidfd_get_owner_uid,
9 sd_pidfd_get_session, sd_pidfd_get_user_unit, sd_pidfd_get_unit,
10 sd_pidfd_get_machine_name, sd_pidfd_get_slice, sd_pidfd_get_user_slice,
11 sd_pidfd_get_cgroup, sd_peer_get_owner_uid, sd_peer_get_session,
12 sd_peer_get_user_unit, sd_peer_get_unit, sd_peer_get_machine_name,
13 sd_peer_get_slice, sd_peer_get_user_slice, sd_peer_get_cgroup -
14 Determine the owner uid of the user unit or session, or the session,
15 user unit, system unit, container/VM or slice that a specific PID or
16 socket peer belongs to
17
19 #include <systemd/sd-login.h>
20 int sd_pid_get_owner_uid(pid_t pid, uid_t *uid);
22 int sd_pid_get_session(pid_t pid, char **session);
24 int sd_pid_get_user_unit(pid_t pid, char **unit);
26 int sd_pid_get_unit(pid_t pid, char **unit);
28 int sd_pid_get_machine_name(pid_t pid, char **name);
30 int sd_pid_get_slice(pid_t pid, char **slice);
32 int sd_pid_get_user_slice(pid_t pid, char **slice);
34 int sd_pid_get_cgroup(pid_t pid, char **cgroup);
36 int sd_pidfd_get_owner_uid(int pidfd, uid_t *uid);
38 int sd_pidfd_get_session(int pidfd, char **session);
40 int sd_pidfd_get_user_unit(int pidfd, char **unit);
42 int sd_pidfd_get_unit(int pidfd, char **unit);
44 int sd_pidfd_get_machine_name(int pidfd, char **name);
46 int sd_pidfd_get_slice(int pidfd, char **slice);
48 int sd_pidfd_get_user_slice(int pidfd, char **slice);
50 int sd_pidfd_get_cgroup(int pidfd, char **cgroup);
52 int sd_peer_get_owner_uid(int fd, uid_t *uid);
54 int sd_peer_get_session(int fd, char **session);
56 int sd_peer_get_user_unit(int fd, char **unit);
58 int sd_peer_get_unit(int fd, char **unit);
60 int sd_peer_get_machine_name(int fd, char **name);
62 int sd_peer_get_slice(int fd, char **slice);
64 int sd_peer_get_user_slice(int fd, char **slice);
66 int sd_peer_get_cgroup(int fd, char **cgroup);
68
70 sd_pid_get_owner_uid() may be used to determine the Unix UID (user
71 identifier) which owns the login session or systemd user unit of a
72 process identified by the specified PID. For processes which are not
73 part of a login session and not managed by a user manager, this
74 function will fail with -ENODATA.
75 sd_pid_get_session() may be used to determine the login session
77 identifier of a process identified by the specified process identifier.
78 The session identifier is a short string, suitable for usage in file
79 system paths. Please note the login session may be limited to a stub
80 process or two. User processes may instead be started from their
81 systemd user manager, e.g. GUI applications started using DBus
82 activation, as well as service processes which are shared between
83 multiple logins of the same user. For processes which are not part of a
84 login session, this function will fail with -ENODATA. The returned
85 string needs to be freed with the libc free(3) call after use.
86 sd_pid_get_user_unit() may be used to determine the systemd user unit
88 (i.e. user service or scope unit) identifier of a process identified by
89 the specified PID. The unit name is a short string, suitable for usage
90 in file system paths. For processes which are not managed by a user
91 manager, this function will fail with -ENODATA. The returned string
92 needs to be freed with the libc free(3) call after use.
93 sd_pid_get_unit() may be used to determine the systemd system unit
95 (i.e. system service or scope unit) identifier of a process identified
96 by the specified PID. The unit name is a short string, suitable for
97 usage in file system paths. Note that not all processes are part of a
98 system unit/service. For processes not being part of a systemd system
99 unit, this function will fail with -ENODATA. (More specifically, this
100 call will not work for kernel threads.) The returned string needs to be
101 freed with the libc free(3) call after use.
102 sd_pid_get_machine_name() may be used to determine the name of the VM
104 or container is a member of. The machine name is a short string,
105 suitable for usage in file system paths. The returned string needs to
106 be freed with the libc free(3) call after use. For processes not part
107 of a VM or container, this function fails with -ENODATA.
108 sd_pid_get_slice() may be used to determine the slice unit the process
110 is a member of. See systemd.slice(5) for details about slices. The
111 returned string needs to be freed with the libc free(3) call after use.
112 Similarly, sd_pid_get_user_slice() returns the user slice (as managed
114 by the user's systemd instance) of a process.
115 sd_pid_get_cgroup() returns the control group path of the specified
117 process, relative to the root of the hierarchy. Returns the path
118 without trailing slash, except for processes located in the root
119 control group, where "/" is returned. To find the actual control group
120 path in the file system, the returned path needs to be prefixed with
121 /sys/fs/cgroup/ (if the unified control group setup is used), or
122 /sys/fs/cgroup/HIERARCHY/ (if the legacy multi-hierarchy control group
123 setup is used).
124 If the pid parameter of any of these functions is passed as 0, the
126 operation is executed for the calling process.
127 The sd_pidfd_get_owner_uid(), sd_pidfd_get_session(),
129 sd_pidfd_get_user_unit(), sd_pidfd_get_unit(),
130 sd_pidfd_get_machine_name(), sd_pidfd_get_slice(),
131 sd_pidfd_get_user_slice() and sd_pidfd_get_cgroup() calls operate
132 similarly to their PID counterparts, but accept a PIDFD instead of a
133 PID, which means they are not subject to recycle race conditions as the
134 process is pinned by the file descriptor during the whole duration of
135 the invocation. Note that these require a kernel that supports PIDFD. A
136 suitable file descriptor may be acquired via pidfd_open(2).
137 The sd_peer_get_owner_uid(), sd_peer_get_session(),
139 sd_peer_get_user_unit(), sd_peer_get_unit(),
140 sd_peer_get_machine_name(), sd_peer_get_slice(),
141 sd_peer_get_user_slice() and sd_peer_get_cgroup() calls operate
142 similarly to their PID counterparts, but accept a connected AF_UNIX
143 socket and retrieve information about the connected peer process. Note
144 that these fields are retrieved via /proc/, and hence are not suitable
145 for authorization purposes, as they are subject to races.
146
148 On success, these calls return 0 or a positive integer. On failure,
149 these calls return a negative errno-style error code.
150 Errors
152 Returned errors may indicate the following problems:
153 -ESRCH
155 The specified PID does not refer to a running process.
156 -EBADF
158 The specified socket file descriptor was invalid.
159 -ENODATA
161 The given field is not specified for the described process or peer.
162 -EINVAL
164 An input parameter was invalid (out of range, or NULL, where that
165 is not accepted).
166 -ENOMEM
168 Memory allocation failed.
169
171 Functions described here are available as a shared library, which can
172 be compiled against and linked to with the libsystemd pkg-config(1)
173 file.
174 Note that the login session identifier as returned by
176 sd_pid_get_session() is completely unrelated to the process session
177 identifier as returned by getsid(2).
178
180 systemd(1), sd-login(3), sd_session_is_active(3), getsid(2),
181 systemd.slice(5), systemd-machined.service(8)
182systemd 254 SD_PID_GET_OWNER_UID(3)