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 Seat
*seat_new(Manager
*m
, const char *id
) {
34 s
->state_file
= strappend("/run/systemd/seats/", id
);
38 s
->id
= basename(s
->state_file
);
41 if (hashmap_put(m
->seats
, s
->id
, s
) < 0) {
49 void seat_free(Seat
*s
) {
53 LIST_REMOVE(gc_queue
, s
->manager
->seat_gc_queue
, s
);
56 session_free(s
->sessions
);
61 device_free(s
->devices
);
63 hashmap_remove(s
->manager
->seats
, s
->id
);
70 int seat_save(Seat
*s
) {
71 _cleanup_free_
char *temp_path
= NULL
;
72 _cleanup_fclose_
FILE *f
= NULL
;
80 r
= mkdir_safe_label("/run/systemd/seats", 0755, 0, 0, MKDIR_WARN_MODE
);
84 r
= fopen_temporary(s
->state_file
, &f
, &temp_path
);
88 (void) __fsetlocking(f
, FSETLOCKING_BYCALLER
);
89 (void) fchmod(fileno(f
), 0644);
92 "# This is private data. Do not parse.\n"
94 "CAN_MULTI_SESSION=%i\n"
98 seat_can_multi_session(s
),
100 seat_can_graphical(s
));
103 assert(s
->active
->user
);
107 "ACTIVE_UID="UID_FMT
"\n",
109 s
->active
->user
->uid
);
115 fputs("SESSIONS=", f
);
116 LIST_FOREACH(sessions_by_seat
, i
, s
->sessions
) {
120 i
->sessions_by_seat_next
? ' ' : '\n');
124 LIST_FOREACH(sessions_by_seat
, i
, s
->sessions
)
128 i
->sessions_by_seat_next
? ' ' : '\n');
131 r
= fflush_and_check(f
);
135 if (rename(temp_path
, s
->state_file
) < 0) {
143 (void) unlink(s
->state_file
);
146 (void) unlink(temp_path
);
148 return log_error_errno(r
, "Failed to save seat data %s: %m", s
->state_file
);
151 int seat_load(Seat
*s
) {
154 /* There isn't actually anything to read here ... */
159 static int vt_allocate(unsigned int vtnr
) {
160 char p
[sizeof("/dev/tty") + DECIMAL_STR_MAX(unsigned int)];
161 _cleanup_close_
int fd
= -1;
165 xsprintf(p
, "/dev/tty%u", vtnr
);
166 fd
= open_terminal(p
, O_RDWR
|O_NOCTTY
|O_CLOEXEC
);
173 int seat_preallocate_vts(Seat
*s
) {
180 log_debug("Preallocating VTs...");
182 if (s
->manager
->n_autovts
<= 0)
185 if (!seat_has_vts(s
))
188 for (i
= 1; i
<= s
->manager
->n_autovts
; i
++) {
193 log_error_errno(q
, "Failed to preallocate VT %u: %m", i
);
201 int seat_apply_acls(Seat
*s
, Session
*old_active
) {
206 r
= devnode_acl_all(s
->id
,
208 !!old_active
, old_active
? old_active
->user
->uid
: 0,
209 !!s
->active
, s
->active
? s
->active
->user
->uid
: 0);
212 log_error_errno(r
, "Failed to apply ACLs: %m");
217 int seat_set_active(Seat
*s
, Session
*session
) {
221 assert(!session
|| session
->seat
== s
);
223 if (session
== s
->active
)
226 old_active
= s
->active
;
230 session_device_pause_all(old_active
);
231 session_send_changed(old_active
, "Active", NULL
);
234 seat_apply_acls(s
, old_active
);
236 if (session
&& session
->started
) {
237 session_send_changed(session
, "Active", NULL
);
238 session_device_resume_all(session
);
241 if (!session
|| session
->started
)
242 seat_send_changed(s
, "ActiveSession", NULL
);
247 session_save(session
);
248 user_save(session
->user
);
252 session_save(old_active
);
253 if (!session
|| session
->user
!= old_active
->user
)
254 user_save(old_active
->user
);
260 int seat_switch_to(Seat
*s
, unsigned int num
) {
261 /* Public session positions skip 0 (there is only F1-F12). Maybe it
262 * will get reassigned in the future, so return error for now. */
266 if (num
>= s
->position_count
|| !s
->positions
[num
]) {
267 /* allow switching to unused VTs to trigger auto-activate */
268 if (seat_has_vts(s
) && num
< 64)
274 return session_activate(s
->positions
[num
]);
277 int seat_switch_to_next(Seat
*s
) {
278 unsigned int start
, i
;
280 if (s
->position_count
== 0)
284 if (s
->active
&& s
->active
->position
> 0)
285 start
= s
->active
->position
;
287 for (i
= start
+ 1; i
< s
->position_count
; ++i
)
289 return session_activate(s
->positions
[i
]);
291 for (i
= 1; i
< start
; ++i
)
293 return session_activate(s
->positions
[i
]);
298 int seat_switch_to_previous(Seat
*s
) {
299 unsigned int start
, i
;
301 if (s
->position_count
== 0)
305 if (s
->active
&& s
->active
->position
> 0)
306 start
= s
->active
->position
;
308 for (i
= start
- 1; i
> 0; --i
)
310 return session_activate(s
->positions
[i
]);
312 for (i
= s
->position_count
- 1; i
> start
; --i
)
314 return session_activate(s
->positions
[i
]);
319 int seat_active_vt_changed(Seat
*s
, unsigned int vtnr
) {
320 Session
*i
, *new_active
= NULL
;
326 if (!seat_has_vts(s
))
329 log_debug("VT changed to %u", vtnr
);
331 /* we might have earlier closing sessions on the same VT, so try to
332 * find a running one first */
333 LIST_FOREACH(sessions_by_seat
, i
, s
->sessions
)
334 if (i
->vtnr
== vtnr
&& !i
->stopping
) {
340 /* no running one? then we can't decide which one is the
341 * active one, let the first one win */
342 LIST_FOREACH(sessions_by_seat
, i
, s
->sessions
)
343 if (i
->vtnr
== vtnr
) {
349 r
= seat_set_active(s
, new_active
);
350 manager_spawn_autovt(s
->manager
, vtnr
);
355 int seat_read_active_vt(Seat
*s
) {
363 if (!seat_has_vts(s
))
366 if (lseek(s
->manager
->console_active_fd
, SEEK_SET
, 0) < 0)
367 return log_error_errno(errno
, "lseek on console_active_fd failed: %m");
369 k
= read(s
->manager
->console_active_fd
, t
, sizeof(t
)-1);
371 log_error("Failed to read current console: %s", k
< 0 ? strerror(-errno
) : "EOF");
372 return k
< 0 ? -errno
: -EIO
;
378 if (!startswith(t
, "tty")) {
379 log_error("Hm, /sys/class/tty/tty0/active is badly formatted.");
383 r
= safe_atou(t
+3, &vtnr
);
385 return log_error_errno(r
, "Failed to parse VT number \"%s\": %m", t
+3);
388 log_error("VT number invalid: %s", t
+3);
392 return seat_active_vt_changed(s
, vtnr
);
395 int seat_start(Seat
*s
) {
402 "MESSAGE_ID=" SD_MESSAGE_SEAT_START_STR
,
404 LOG_MESSAGE("New seat %s.", s
->id
));
406 /* Initialize VT magic stuff */
407 seat_preallocate_vts(s
);
409 /* Read current VT */
410 seat_read_active_vt(s
);
417 seat_send_signal(s
, true);
422 int seat_stop(Seat
*s
, bool force
) {
429 "MESSAGE_ID=" SD_MESSAGE_SEAT_STOP_STR
,
431 LOG_MESSAGE("Removed seat %s.", s
->id
));
433 seat_stop_sessions(s
, force
);
435 unlink(s
->state_file
);
436 seat_add_to_gc_queue(s
);
439 seat_send_signal(s
, false);
446 int seat_stop_sessions(Seat
*s
, bool force
) {
452 LIST_FOREACH(sessions_by_seat
, session
, s
->sessions
) {
453 k
= session_stop(session
, force
);
461 void seat_evict_position(Seat
*s
, Session
*session
) {
463 unsigned int pos
= session
->position
;
465 session
->position
= 0;
470 if (pos
< s
->position_count
&& s
->positions
[pos
] == session
) {
471 s
->positions
[pos
] = NULL
;
473 /* There might be another session claiming the same
474 * position (eg., during gdm->session transition), so let's look
475 * for it and set it on the free slot. */
476 LIST_FOREACH(sessions_by_seat
, iter
, s
->sessions
) {
477 if (iter
->position
== pos
&& session_get_state(iter
) != SESSION_CLOSING
) {
478 s
->positions
[pos
] = iter
;
485 void seat_claim_position(Seat
*s
, Session
*session
, unsigned int pos
) {
486 /* with VTs, the position is always the same as the VTnr */
490 if (!GREEDY_REALLOC0(s
->positions
, s
->position_count
, pos
+ 1))
493 seat_evict_position(s
, session
);
495 session
->position
= pos
;
497 s
->positions
[pos
] = session
;
500 static void seat_assign_position(Seat
*s
, Session
*session
) {
503 if (session
->position
> 0)
506 for (pos
= 1; pos
< s
->position_count
; ++pos
)
507 if (!s
->positions
[pos
])
510 seat_claim_position(s
, session
, pos
);
513 int seat_attach_session(Seat
*s
, Session
*session
) {
516 assert(!session
->seat
);
518 if (!seat_has_vts(s
) != !session
->vtnr
)
522 LIST_PREPEND(sessions_by_seat
, s
->sessions
, session
);
523 seat_assign_position(s
, session
);
525 /* On seats with VTs, the VT logic defines which session is active. On
526 * seats without VTs, we automatically activate new sessions. */
527 if (!seat_has_vts(s
))
528 seat_set_active(s
, session
);
533 void seat_complete_switch(Seat
*s
) {
538 /* if no session-switch is pending or if it got canceled, do nothing */
539 if (!s
->pending_switch
)
542 session
= TAKE_PTR(s
->pending_switch
);
544 seat_set_active(s
, session
);
547 bool seat_has_vts(Seat
*s
) {
550 return seat_is_seat0(s
) && s
->manager
->console_active_fd
>= 0;
553 bool seat_is_seat0(Seat
*s
) {
556 return s
->manager
->seat0
== s
;
559 bool seat_can_multi_session(Seat
*s
) {
562 return seat_has_vts(s
);
565 bool seat_can_tty(Seat
*s
) {
568 return seat_has_vts(s
);
571 bool seat_has_master_device(Seat
*s
) {
574 /* device list is ordered by "master" flag */
575 return !!s
->devices
&& s
->devices
->master
;
578 bool seat_can_graphical(Seat
*s
) {
581 return seat_has_master_device(s
);
584 int seat_get_idle_hint(Seat
*s
, dual_timestamp
*t
) {
586 bool idle_hint
= true;
587 dual_timestamp ts
= DUAL_TIMESTAMP_NULL
;
591 LIST_FOREACH(sessions_by_seat
, session
, s
->sessions
) {
595 ih
= session_get_idle_hint(session
, &k
);
601 if (k
.monotonic
> ts
.monotonic
)
607 } else if (idle_hint
) {
609 if (k
.monotonic
> ts
.monotonic
)
620 bool seat_may_gc(Seat
*s
, bool drop_not_started
) {
623 if (drop_not_started
&& !s
->started
)
626 if (seat_is_seat0(s
))
629 return !seat_has_master_device(s
);
632 void seat_add_to_gc_queue(Seat
*s
) {
638 LIST_PREPEND(gc_queue
, s
->manager
->seat_gc_queue
, s
);
639 s
->in_gc_queue
= true;
642 static bool seat_name_valid_char(char c
) {
644 (c
>= 'a' && c
<= 'z') ||
645 (c
>= 'A' && c
<= 'Z') ||
646 (c
>= '0' && c
<= '9') ||
650 bool seat_name_is_valid(const char *name
) {
655 if (!startswith(name
, "seat"))
661 for (p
= name
; *p
; p
++)
662 if (!seat_name_valid_char(*p
))
665 if (strlen(name
) > 255)