src/systemd/sd-login.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #ifndef foosdloginhfoo
   3 #define foosdloginhfoo
   4
   5 /***
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <https://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <inttypes.h>
  21 #include <sys/types.h>
  22
  23 #include "_sd-common.h"
  24
  25 /*
  26  * A few points:
  27  *
  28  * Instead of returning an empty string array or empty uid array, we
  29  * may return NULL.
  30  *
  31  * Free the data the library returns with libc free(). String arrays
  32  * are NULL terminated, and you need to free the array itself, in
  33  * addition to the strings contained.
  34  *
  35  * We return error codes as negative errno, kernel-style. On success, we
  36  * return 0 or positive.
  37  *
  38  * These functions access data in /proc, /sys/fs/cgroup, and /run. All
  39  * of these are virtual file systems; therefore, accesses are
  40  * relatively cheap.
  41  *
  42  * See sd-login(3) for more information.
  43  */
  44
  45 _SD_BEGIN_DECLARATIONS;
  46
  47 /* Get session from PID. Note that 'shared' processes of a user are
  48  * not attached to a session, but only attached to a user. This will
  49  * return an error for system processes and 'shared' processes of a
  50  * user. */
  51 int sd_pid_get_session(pid_t pid, char **session);
  52
  53 /* Get UID of the owner of the session of the PID (or in case the
  54  * process is a 'shared' user process, the UID of that user is
  55  * returned). This will not return the UID of the process, but rather
  56  * the UID of the owner of the cgroup that the process is in. This will
  57  * return an error for system processes. */
  58 int sd_pid_get_owner_uid(pid_t pid, uid_t *uid);
  59
  60 /* Get systemd non-slice unit (i.e. service) name from PID, for system
  61  * services. This will return an error for non-service processes. */
  62 int sd_pid_get_unit(pid_t pid, char **unit);
  63
  64 /* Get systemd non-slice unit (i.e. service) name from PID, for user
  65  * services. This will return an error for non-user-service
  66  * processes. */
  67 int sd_pid_get_user_unit(pid_t pid, char **unit);
  68
  69 /* Get slice name from PID. */
  70 int sd_pid_get_slice(pid_t pid, char **slice);
  71
  72 /* Get user slice name from PID. */
  73 int sd_pid_get_user_slice(pid_t pid, char **slice);
  74
  75 /* Get machine name from PID, for processes assigned to a VM or
  76  * container. This will return an error for non-machine processes. */
  77 int sd_pid_get_machine_name(pid_t pid, char **machine);
  78
  79 /* Get the control group from a PID, relative to the root of the
  80  * hierarchy. */
  81 int sd_pid_get_cgroup(pid_t pid, char **cgroup);
  82
  83 /* Equivalent to the corresponding sd_pid_get* functions, but take a
  84  * PIDFD instead of a PID, to ensure there can be no possible PID
  85  * recycle issues before/after the calls. */
  86 int sd_pidfd_get_session(pid_t pid, char **session);
  87 int sd_pidfd_get_owner_uid(pid_t pid, uid_t *uid);
  88 int sd_pidfd_get_unit(pid_t pid, char **unit);
  89 int sd_pidfd_get_user_unit(pid_t pid, char **unit);
  90 int sd_pidfd_get_slice(pid_t pid, char **slice);
  91 int sd_pidfd_get_user_slice(pid_t pid, char **slice);
  92 int sd_pidfd_get_machine_name(pid_t pid, char **machine);
  93 int sd_pidfd_get_cgroup(pid_t pid, char **cgroup);
  94
  95 /* Similar to sd_pid_get_session(), but retrieves data about the peer
  96  * of a connected AF_UNIX socket */
  97 int sd_peer_get_session(int fd, char **session);
  98
  99 /* Similar to sd_pid_get_owner_uid(), but retrieves data about the peer of
 100  * a connected AF_UNIX socket */
 101 int sd_peer_get_owner_uid(int fd, uid_t *uid);
 102
 103 /* Similar to sd_pid_get_unit(), but retrieves data about the peer of
 104  * a connected AF_UNIX socket */
 105 int sd_peer_get_unit(int fd, char **unit);
 106
 107 /* Similar to sd_pid_get_user_unit(), but retrieves data about the peer of
 108  * a connected AF_UNIX socket */
 109 int sd_peer_get_user_unit(int fd, char **unit);
 110
 111 /* Similar to sd_pid_get_slice(), but retrieves data about the peer of
 112  * a connected AF_UNIX socket */
 113 int sd_peer_get_slice(int fd, char **slice);
 114
 115 /* Similar to sd_pid_get_user_slice(), but retrieves data about the peer of
 116  * a connected AF_UNIX socket */
 117 int sd_peer_get_user_slice(int fd, char **slice);
 118
 119 /* Similar to sd_pid_get_machine_name(), but retrieves data about the
 120  * peer of a connected AF_UNIX socket */
 121 int sd_peer_get_machine_name(int fd, char **machine);
 122
 123 /* Similar to sd_pid_get_cgroup(), but retrieves data about the peer
 124  * of a connected AF_UNIX socket. */
 125 int sd_peer_get_cgroup(int fd, char **cgroup);
 126
 127 /* Get state from UID. Possible states: offline, lingering, online, active, closing */
 128 int sd_uid_get_state(uid_t uid, char **state);
 129
 130 /* Return primary session of user, if there is any */
 131 int sd_uid_get_display(uid_t uid, char **session);
 132
 133 /* Return 1 if UID has session on seat. If require_active is true, this will
 134  * look for active sessions only. */
 135 int sd_uid_is_on_seat(uid_t uid, int require_active, const char *seat);
 136
 137 /* Return sessions of user. If require_active is true, this will look for
 138  * active sessions only. Returns the number of sessions.
 139  * If sessions is NULL, this will just return the number of sessions. */
 140 int sd_uid_get_sessions(uid_t uid, int require_active, char ***sessions);
 141
 142 /* Return seats of user is on. If require_active is true, this will look for
 143  * active seats only. Returns the number of seats.
 144  * If seats is NULL, this will just return the number of seats. */
 145 int sd_uid_get_seats(uid_t uid, int require_active, char ***seats);
 146
 147 /* Return 1 if the session is active. */
 148 int sd_session_is_active(const char *session);
 149
 150 /* Return 1 if the session is remote. */
 151 int sd_session_is_remote(const char *session);
 152
 153 /* Get state from session. Possible states: online, active, closing.
 154  * This function is a more generic version of sd_session_is_active(). */
 155 int sd_session_get_state(const char *session, char **state);
 156
 157 /* Determine user ID of session */
 158 int sd_session_get_uid(const char *session, uid_t *uid);
 159
 160 /* Determine username of session */
 161 int sd_session_get_username(const char *session, char **username);
 162
 163 /* Determine seat of session */
 164 int sd_session_get_seat(const char *session, char **seat);
 165
 166 /* Determine the start time of session */
 167 int sd_session_get_start_time(const char *session, uint64_t *usec);
 168
 169 /* Determine the (PAM) service name this session was registered by. */
 170 int sd_session_get_service(const char *session, char **service);
 171
 172 /* Determine the type of this session, i.e. one of "tty", "x11", "wayland", "mir" or "unspecified". */
 173 int sd_session_get_type(const char *session, char **type);
 174
 175 /* Determine the class of this session, i.e. one of "user", "greeter" or "lock-screen". */
 176 int sd_session_get_class(const char *session, char **clazz);
 177
 178 /* Determine the desktop brand of this session, i.e. something like "GNOME", "KDE" or "systemd-console". */
 179 int sd_session_get_desktop(const char *session, char **desktop);
 180
 181 /* Determine the X11 display of this session. */
 182 int sd_session_get_display(const char *session, char **display);
 183
 184 /* Determine the remote host of this session. */
 185 int sd_session_get_remote_host(const char *session, char **remote_host);
 186
 187 /* Determine the remote user of this session (if provided by PAM). */
 188 int sd_session_get_remote_user(const char *session, char **remote_user);
 189
 190 /* Determine the TTY of this session. */
 191 int sd_session_get_tty(const char *session, char **display);
 192
 193 /* Determine the VT number of this session. */
 194 int sd_session_get_vt(const char *session, unsigned *vtnr);
 195
 196 /* Return active session and user of seat */
 197 int sd_seat_get_active(const char *seat, char **session, uid_t *uid);
 198
 199 /* Return sessions and users on seat. Returns number of sessions.
 200  * If sessions is NULL, this returns only the number of sessions. */
 201 int sd_seat_get_sessions(
 202                 const char *seat,
 203                 char ***ret_sessions,
 204                 uid_t **ret_uids,
 205                 unsigned *ret_n_uids);
 206
 207 /* Return whether the seat is multi-session capable */
 208 int sd_seat_can_multi_session(const char *seat) _sd_deprecated_;
 209
 210 /* Return whether the seat is TTY capable, i.e. suitable for showing console UIs */
 211 int sd_seat_can_tty(const char *seat);
 212
 213 /* Return whether the seat is graphics capable, i.e. suitable for showing graphical UIs */
 214 int sd_seat_can_graphical(const char *seat);
 215
 216 /* Return the class of machine */
 217 int sd_machine_get_class(const char *machine, char **clazz);
 218
 219 /* Return the list if host-side network interface indices of a machine */
 220 int sd_machine_get_ifindices(const char *machine, int **ret_ifindices);
 221
 222 /* Get all seats, store in *seats. Returns the number of seats. If
 223  * seats is NULL, this only returns the number of seats. */
 224 int sd_get_seats(char ***seats);
 225
 226 /* Get all sessions, store in *sessions. Returns the number of
 227  * sessions. If sessions is NULL, this only returns the number of sessions. */
 228 int sd_get_sessions(char ***sessions);
 229
 230 /* Get all logged in users, store in *users. Returns the number of
 231  * users. If users is NULL, this only returns the number of users. */
 232 int sd_get_uids(uid_t **users);
 233
 234 /* Get all running virtual machines/containers */
 235 int sd_get_machine_names(char ***machines);
 236
 237 /* Monitor object */
 238 typedef struct sd_login_monitor sd_login_monitor;
 239
 240 /* Create a new monitor. Category must be NULL, "seat", "session",
 241  * "uid", or "machine" to get monitor events for the specific category
 242  * (or all). */
 243 int sd_login_monitor_new(const char *category, sd_login_monitor** ret);
 244
 245 /* Destroys the passed monitor. Returns NULL. */
 246 sd_login_monitor* sd_login_monitor_unref(sd_login_monitor *m);
 247
 248 /* Flushes the monitor */
 249 int sd_login_monitor_flush(sd_login_monitor *m);
 250
 251 /* Get FD from monitor */
 252 int sd_login_monitor_get_fd(sd_login_monitor *m);
 253
 254 /* Get poll() mask to monitor */
 255 int sd_login_monitor_get_events(sd_login_monitor *m);
 256
 257 /* Get timeout for poll(), as usec value relative to CLOCK_MONOTONIC's epoch */
 258 int sd_login_monitor_get_timeout(sd_login_monitor *m, uint64_t *timeout_usec);
 259
 260 _SD_DEFINE_POINTER_CLEANUP_FUNC(sd_login_monitor, sd_login_monitor_unref);
 261
 262 _SD_END_DECLARATIONS;
 263
 264 #endif