1 /* SPDX-License-Identifier: LGPL-2.1+ */
9 #include "sd-messages.h"
11 #include "alloc-util.h"
14 #include "format-util.h"
15 #include "logind-acl.h"
16 #include "logind-seat.h"
18 #include "parse-util.h"
19 #include "stdio-util.h"
20 #include "string-util.h"
21 #include "terminal-util.h"
24 int seat_new(Seat
** ret
, Manager
*m
, const char *id
) {
25 _cleanup_(seat_freep
) Seat
*s
= NULL
;
32 if (!seat_name_is_valid(id
))
43 s
->state_file
= strappend("/run/systemd/seats/", id
);
47 s
->id
= basename(s
->state_file
);
49 r
= hashmap_put(m
->seats
, s
->id
, s
);
57 Seat
* seat_free(Seat
*s
) {
62 LIST_REMOVE(gc_queue
, s
->manager
->seat_gc_queue
, s
);
65 session_free(s
->sessions
);
70 device_free(s
->devices
);
72 hashmap_remove(s
->manager
->seats
, s
->id
);
80 int seat_save(Seat
*s
) {
81 _cleanup_free_
char *temp_path
= NULL
;
82 _cleanup_fclose_
FILE *f
= NULL
;
90 r
= mkdir_safe_label("/run/systemd/seats", 0755, 0, 0, MKDIR_WARN_MODE
);
94 r
= fopen_temporary(s
->state_file
, &f
, &temp_path
);
98 (void) __fsetlocking(f
, FSETLOCKING_BYCALLER
);
99 (void) fchmod(fileno(f
), 0644);
102 "# This is private data. Do not parse.\n"
104 "CAN_MULTI_SESSION=%i\n"
106 "CAN_GRAPHICAL=%i\n",
108 seat_can_multi_session(s
),
110 seat_can_graphical(s
));
113 assert(s
->active
->user
);
117 "ACTIVE_UID="UID_FMT
"\n",
119 s
->active
->user
->uid
);
125 fputs("SESSIONS=", f
);
126 LIST_FOREACH(sessions_by_seat
, i
, s
->sessions
) {
130 i
->sessions_by_seat_next
? ' ' : '\n');
134 LIST_FOREACH(sessions_by_seat
, i
, s
->sessions
)
138 i
->sessions_by_seat_next
? ' ' : '\n');
141 r
= fflush_and_check(f
);
145 if (rename(temp_path
, s
->state_file
) < 0) {
153 (void) unlink(s
->state_file
);
156 (void) unlink(temp_path
);
158 return log_error_errno(r
, "Failed to save seat data %s: %m", s
->state_file
);
161 int seat_load(Seat
*s
) {
164 /* There isn't actually anything to read here ... */
169 static int vt_allocate(unsigned int vtnr
) {
170 char p
[sizeof("/dev/tty") + DECIMAL_STR_MAX(unsigned int)];
171 _cleanup_close_
int fd
= -1;
175 xsprintf(p
, "/dev/tty%u", vtnr
);
176 fd
= open_terminal(p
, O_RDWR
|O_NOCTTY
|O_CLOEXEC
);
183 int seat_preallocate_vts(Seat
*s
) {
190 log_debug("Preallocating VTs...");
192 if (s
->manager
->n_autovts
<= 0)
195 if (!seat_has_vts(s
))
198 for (i
= 1; i
<= s
->manager
->n_autovts
; i
++) {
203 r
= log_error_errno(q
, "Failed to preallocate VT %u: %m", i
);
209 int seat_apply_acls(Seat
*s
, Session
*old_active
) {
214 r
= devnode_acl_all(s
->id
,
216 !!old_active
, old_active
? old_active
->user
->uid
: 0,
217 !!s
->active
, s
->active
? s
->active
->user
->uid
: 0);
220 return log_error_errno(r
, "Failed to apply ACLs: %m");
225 int seat_set_active(Seat
*s
, Session
*session
) {
229 assert(!session
|| session
->seat
== s
);
231 if (session
== s
->active
)
234 old_active
= s
->active
;
238 session_device_pause_all(old_active
);
239 session_send_changed(old_active
, "Active", NULL
);
242 (void) seat_apply_acls(s
, old_active
);
244 if (session
&& session
->started
) {
245 session_send_changed(session
, "Active", NULL
);
246 session_device_resume_all(session
);
249 if (!session
|| session
->started
)
250 seat_send_changed(s
, "ActiveSession", NULL
);
255 session_save(session
);
256 user_save(session
->user
);
260 session_save(old_active
);
261 if (!session
|| session
->user
!= old_active
->user
)
262 user_save(old_active
->user
);
268 int seat_switch_to(Seat
*s
, unsigned int num
) {
269 /* Public session positions skip 0 (there is only F1-F12). Maybe it
270 * will get reassigned in the future, so return error for now. */
274 if (num
>= s
->position_count
|| !s
->positions
[num
]) {
275 /* allow switching to unused VTs to trigger auto-activate */
276 if (seat_has_vts(s
) && num
< 64)
282 return session_activate(s
->positions
[num
]);
285 int seat_switch_to_next(Seat
*s
) {
286 unsigned int start
, i
;
288 if (s
->position_count
== 0)
292 if (s
->active
&& s
->active
->position
> 0)
293 start
= s
->active
->position
;
295 for (i
= start
+ 1; i
< s
->position_count
; ++i
)
297 return session_activate(s
->positions
[i
]);
299 for (i
= 1; i
< start
; ++i
)
301 return session_activate(s
->positions
[i
]);
306 int seat_switch_to_previous(Seat
*s
) {
307 unsigned int start
, i
;
309 if (s
->position_count
== 0)
313 if (s
->active
&& s
->active
->position
> 0)
314 start
= s
->active
->position
;
316 for (i
= start
- 1; i
> 0; --i
)
318 return session_activate(s
->positions
[i
]);
320 for (i
= s
->position_count
- 1; i
> start
; --i
)
322 return session_activate(s
->positions
[i
]);
327 int seat_active_vt_changed(Seat
*s
, unsigned int vtnr
) {
328 Session
*i
, *new_active
= NULL
;
334 if (!seat_has_vts(s
))
337 log_debug("VT changed to %u", vtnr
);
339 /* we might have earlier closing sessions on the same VT, so try to
340 * find a running one first */
341 LIST_FOREACH(sessions_by_seat
, i
, s
->sessions
)
342 if (i
->vtnr
== vtnr
&& !i
->stopping
) {
348 /* no running one? then we can't decide which one is the
349 * active one, let the first one win */
350 LIST_FOREACH(sessions_by_seat
, i
, s
->sessions
)
351 if (i
->vtnr
== vtnr
) {
357 r
= seat_set_active(s
, new_active
);
358 manager_spawn_autovt(s
->manager
, vtnr
);
363 int seat_read_active_vt(Seat
*s
) {
370 if (!seat_has_vts(s
))
373 if (lseek(s
->manager
->console_active_fd
, SEEK_SET
, 0) < 0)
374 return log_error_errno(errno
, "lseek on console_active_fd failed: %m");
376 k
= read(s
->manager
->console_active_fd
, t
, sizeof(t
)-1);
378 log_error("Failed to read current console: %s", k
< 0 ? strerror(-errno
) : "EOF");
379 return k
< 0 ? -errno
: -EIO
;
385 vtnr
= vtnr_from_tty(t
);
387 log_error_errno(vtnr
, "Hm, /sys/class/tty/tty0/active is badly formatted: %m");
391 return seat_active_vt_changed(s
, vtnr
);
394 int seat_start(Seat
*s
) {
401 "MESSAGE_ID=" SD_MESSAGE_SEAT_START_STR
,
403 LOG_MESSAGE("New seat %s.", s
->id
));
405 /* Initialize VT magic stuff */
406 seat_preallocate_vts(s
);
408 /* Read current VT */
409 seat_read_active_vt(s
);
416 seat_send_signal(s
, true);
421 int seat_stop(Seat
*s
, bool force
) {
428 "MESSAGE_ID=" SD_MESSAGE_SEAT_STOP_STR
,
430 LOG_MESSAGE("Removed seat %s.", s
->id
));
432 seat_stop_sessions(s
, force
);
434 (void) unlink(s
->state_file
);
435 seat_add_to_gc_queue(s
);
438 seat_send_signal(s
, false);
445 int seat_stop_sessions(Seat
*s
, bool force
) {
451 LIST_FOREACH(sessions_by_seat
, session
, s
->sessions
) {
452 k
= session_stop(session
, force
);
460 void seat_evict_position(Seat
*s
, Session
*session
) {
462 unsigned int pos
= session
->position
;
464 session
->position
= 0;
469 if (pos
< s
->position_count
&& s
->positions
[pos
] == session
) {
470 s
->positions
[pos
] = NULL
;
472 /* There might be another session claiming the same
473 * position (eg., during gdm->session transition), so let's look
474 * for it and set it on the free slot. */
475 LIST_FOREACH(sessions_by_seat
, iter
, s
->sessions
) {
476 if (iter
->position
== pos
&& session_get_state(iter
) != SESSION_CLOSING
) {
477 s
->positions
[pos
] = iter
;
484 void seat_claim_position(Seat
*s
, Session
*session
, unsigned int pos
) {
485 /* with VTs, the position is always the same as the VTnr */
489 if (!GREEDY_REALLOC0(s
->positions
, s
->position_count
, pos
+ 1))
492 seat_evict_position(s
, session
);
494 session
->position
= pos
;
496 s
->positions
[pos
] = session
;
499 static void seat_assign_position(Seat
*s
, Session
*session
) {
502 if (session
->position
> 0)
505 for (pos
= 1; pos
< s
->position_count
; ++pos
)
506 if (!s
->positions
[pos
])
509 seat_claim_position(s
, session
, pos
);
512 int seat_attach_session(Seat
*s
, Session
*session
) {
515 assert(!session
->seat
);
517 if (!seat_has_vts(s
) != !session
->vtnr
)
521 LIST_PREPEND(sessions_by_seat
, s
->sessions
, session
);
522 seat_assign_position(s
, session
);
524 /* On seats with VTs, the VT logic defines which session is active. On
525 * seats without VTs, we automatically activate new sessions. */
526 if (!seat_has_vts(s
))
527 seat_set_active(s
, session
);
532 void seat_complete_switch(Seat
*s
) {
537 /* if no session-switch is pending or if it got canceled, do nothing */
538 if (!s
->pending_switch
)
541 session
= TAKE_PTR(s
->pending_switch
);
543 seat_set_active(s
, session
);
546 bool seat_has_vts(Seat
*s
) {
549 return seat_is_seat0(s
) && s
->manager
->console_active_fd
>= 0;
552 bool seat_is_seat0(Seat
*s
) {
555 return s
->manager
->seat0
== s
;
558 bool seat_can_multi_session(Seat
*s
) {
561 return seat_has_vts(s
);
564 bool seat_can_tty(Seat
*s
) {
567 return seat_has_vts(s
);
570 bool seat_has_master_device(Seat
*s
) {
573 /* device list is ordered by "master" flag */
574 return !!s
->devices
&& s
->devices
->master
;
577 bool seat_can_graphical(Seat
*s
) {
580 return seat_has_master_device(s
);
583 int seat_get_idle_hint(Seat
*s
, dual_timestamp
*t
) {
585 bool idle_hint
= true;
586 dual_timestamp ts
= DUAL_TIMESTAMP_NULL
;
590 LIST_FOREACH(sessions_by_seat
, session
, s
->sessions
) {
594 ih
= session_get_idle_hint(session
, &k
);
600 if (k
.monotonic
> ts
.monotonic
)
606 } else if (idle_hint
) {
608 if (k
.monotonic
> ts
.monotonic
)
619 bool seat_may_gc(Seat
*s
, bool drop_not_started
) {
622 if (drop_not_started
&& !s
->started
)
625 if (seat_is_seat0(s
))
628 return !seat_has_master_device(s
);
631 void seat_add_to_gc_queue(Seat
*s
) {
637 LIST_PREPEND(gc_queue
, s
->manager
->seat_gc_queue
, s
);
638 s
->in_gc_queue
= true;
641 static bool seat_name_valid_char(char c
) {
643 (c
>= 'a' && c
<= 'z') ||
644 (c
>= 'A' && c
<= 'Z') ||
645 (c
>= '0' && c
<= '9') ||
649 bool seat_name_is_valid(const char *name
) {
654 if (!startswith(name
, "seat"))
660 for (p
= name
; *p
; p
++)
661 if (!seat_name_valid_char(*p
))
664 if (strlen(name
) > 255)