1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 This file is part of systemd.
5 Copyright 2011 Lennart Poettering
10 #include <stdio_ext.h>
14 #include "sd-messages.h"
16 #include "alloc-util.h"
19 #include "format-util.h"
20 #include "logind-acl.h"
21 #include "logind-seat.h"
23 #include "parse-util.h"
24 #include "stdio-util.h"
25 #include "string-util.h"
26 #include "terminal-util.h"
29 Seat
*seat_new(Manager
*m
, const char *id
) {
39 s
->state_file
= strappend("/run/systemd/seats/", id
);
43 s
->id
= basename(s
->state_file
);
46 if (hashmap_put(m
->seats
, s
->id
, s
) < 0) {
54 void seat_free(Seat
*s
) {
58 LIST_REMOVE(gc_queue
, s
->manager
->seat_gc_queue
, s
);
61 session_free(s
->sessions
);
66 device_free(s
->devices
);
68 hashmap_remove(s
->manager
->seats
, s
->id
);
75 int seat_save(Seat
*s
) {
76 _cleanup_free_
char *temp_path
= NULL
;
77 _cleanup_fclose_
FILE *f
= NULL
;
85 r
= mkdir_safe_label("/run/systemd/seats", 0755, 0, 0, MKDIR_WARN_MODE
);
89 r
= fopen_temporary(s
->state_file
, &f
, &temp_path
);
93 (void) __fsetlocking(f
, FSETLOCKING_BYCALLER
);
94 (void) fchmod(fileno(f
), 0644);
97 "# This is private data. Do not parse.\n"
99 "CAN_MULTI_SESSION=%i\n"
101 "CAN_GRAPHICAL=%i\n",
103 seat_can_multi_session(s
),
105 seat_can_graphical(s
));
108 assert(s
->active
->user
);
112 "ACTIVE_UID="UID_FMT
"\n",
114 s
->active
->user
->uid
);
120 fputs("SESSIONS=", f
);
121 LIST_FOREACH(sessions_by_seat
, i
, s
->sessions
) {
125 i
->sessions_by_seat_next
? ' ' : '\n');
129 LIST_FOREACH(sessions_by_seat
, i
, s
->sessions
)
133 i
->sessions_by_seat_next
? ' ' : '\n');
136 r
= fflush_and_check(f
);
140 if (rename(temp_path
, s
->state_file
) < 0) {
148 (void) unlink(s
->state_file
);
151 (void) unlink(temp_path
);
153 return log_error_errno(r
, "Failed to save seat data %s: %m", s
->state_file
);
156 int seat_load(Seat
*s
) {
159 /* There isn't actually anything to read here ... */
164 static int vt_allocate(unsigned int vtnr
) {
165 char p
[sizeof("/dev/tty") + DECIMAL_STR_MAX(unsigned int)];
166 _cleanup_close_
int fd
= -1;
170 xsprintf(p
, "/dev/tty%u", vtnr
);
171 fd
= open_terminal(p
, O_RDWR
|O_NOCTTY
|O_CLOEXEC
);
178 int seat_preallocate_vts(Seat
*s
) {
185 log_debug("Preallocating VTs...");
187 if (s
->manager
->n_autovts
<= 0)
190 if (!seat_has_vts(s
))
193 for (i
= 1; i
<= s
->manager
->n_autovts
; i
++) {
198 log_error_errno(q
, "Failed to preallocate VT %u: %m", i
);
206 int seat_apply_acls(Seat
*s
, Session
*old_active
) {
211 r
= devnode_acl_all(s
->manager
->udev
,
214 !!old_active
, old_active
? old_active
->user
->uid
: 0,
215 !!s
->active
, s
->active
? s
->active
->user
->uid
: 0);
218 log_error_errno(r
, "Failed to apply ACLs: %m");
223 int seat_set_active(Seat
*s
, Session
*session
) {
227 assert(!session
|| session
->seat
== s
);
229 if (session
== s
->active
)
232 old_active
= s
->active
;
236 session_device_pause_all(old_active
);
237 session_send_changed(old_active
, "Active", NULL
);
240 seat_apply_acls(s
, old_active
);
242 if (session
&& session
->started
) {
243 session_send_changed(session
, "Active", NULL
);
244 session_device_resume_all(session
);
247 if (!session
|| session
->started
)
248 seat_send_changed(s
, "ActiveSession", NULL
);
253 session_save(session
);
254 user_save(session
->user
);
258 session_save(old_active
);
259 if (!session
|| session
->user
!= old_active
->user
)
260 user_save(old_active
->user
);
266 int seat_switch_to(Seat
*s
, unsigned int num
) {
267 /* Public session positions skip 0 (there is only F1-F12). Maybe it
268 * will get reassigned in the future, so return error for now. */
272 if (num
>= s
->position_count
|| !s
->positions
[num
]) {
273 /* allow switching to unused VTs to trigger auto-activate */
274 if (seat_has_vts(s
) && num
< 64)
280 return session_activate(s
->positions
[num
]);
283 int seat_switch_to_next(Seat
*s
) {
284 unsigned int start
, i
;
286 if (s
->position_count
== 0)
290 if (s
->active
&& s
->active
->position
> 0)
291 start
= s
->active
->position
;
293 for (i
= start
+ 1; i
< s
->position_count
; ++i
)
295 return session_activate(s
->positions
[i
]);
297 for (i
= 1; i
< start
; ++i
)
299 return session_activate(s
->positions
[i
]);
304 int seat_switch_to_previous(Seat
*s
) {
305 unsigned int start
, i
;
307 if (s
->position_count
== 0)
311 if (s
->active
&& s
->active
->position
> 0)
312 start
= s
->active
->position
;
314 for (i
= start
- 1; i
> 0; --i
)
316 return session_activate(s
->positions
[i
]);
318 for (i
= s
->position_count
- 1; i
> start
; --i
)
320 return session_activate(s
->positions
[i
]);
325 int seat_active_vt_changed(Seat
*s
, unsigned int vtnr
) {
326 Session
*i
, *new_active
= NULL
;
332 if (!seat_has_vts(s
))
335 log_debug("VT changed to %u", vtnr
);
337 /* we might have earlier closing sessions on the same VT, so try to
338 * find a running one first */
339 LIST_FOREACH(sessions_by_seat
, i
, s
->sessions
)
340 if (i
->vtnr
== vtnr
&& !i
->stopping
) {
346 /* no running one? then we can't decide which one is the
347 * active one, let the first one win */
348 LIST_FOREACH(sessions_by_seat
, i
, s
->sessions
)
349 if (i
->vtnr
== vtnr
) {
355 r
= seat_set_active(s
, new_active
);
356 manager_spawn_autovt(s
->manager
, vtnr
);
361 int seat_read_active_vt(Seat
*s
) {
369 if (!seat_has_vts(s
))
372 if (lseek(s
->manager
->console_active_fd
, SEEK_SET
, 0) < 0)
373 return log_error_errno(errno
, "lseek on console_active_fd failed: %m");
375 k
= read(s
->manager
->console_active_fd
, t
, sizeof(t
)-1);
377 log_error("Failed to read current console: %s", k
< 0 ? strerror(-errno
) : "EOF");
378 return k
< 0 ? -errno
: -EIO
;
384 if (!startswith(t
, "tty")) {
385 log_error("Hm, /sys/class/tty/tty0/active is badly formatted.");
389 r
= safe_atou(t
+3, &vtnr
);
391 return log_error_errno(r
, "Failed to parse VT number \"%s\": %m", t
+3);
394 log_error("VT number invalid: %s", t
+3);
398 return seat_active_vt_changed(s
, vtnr
);
401 int seat_start(Seat
*s
) {
408 "MESSAGE_ID=" SD_MESSAGE_SEAT_START_STR
,
410 LOG_MESSAGE("New seat %s.", s
->id
),
413 /* Initialize VT magic stuff */
414 seat_preallocate_vts(s
);
416 /* Read current VT */
417 seat_read_active_vt(s
);
424 seat_send_signal(s
, true);
429 int seat_stop(Seat
*s
, bool force
) {
436 "MESSAGE_ID=" SD_MESSAGE_SEAT_STOP_STR
,
438 LOG_MESSAGE("Removed seat %s.", s
->id
),
441 seat_stop_sessions(s
, force
);
443 unlink(s
->state_file
);
444 seat_add_to_gc_queue(s
);
447 seat_send_signal(s
, false);
454 int seat_stop_sessions(Seat
*s
, bool force
) {
460 LIST_FOREACH(sessions_by_seat
, session
, s
->sessions
) {
461 k
= session_stop(session
, force
);
469 void seat_evict_position(Seat
*s
, Session
*session
) {
471 unsigned int pos
= session
->position
;
473 session
->position
= 0;
478 if (pos
< s
->position_count
&& s
->positions
[pos
] == session
) {
479 s
->positions
[pos
] = NULL
;
481 /* There might be another session claiming the same
482 * position (eg., during gdm->session transition), so let's look
483 * for it and set it on the free slot. */
484 LIST_FOREACH(sessions_by_seat
, iter
, s
->sessions
) {
485 if (iter
->position
== pos
&& session_get_state(iter
) != SESSION_CLOSING
) {
486 s
->positions
[pos
] = iter
;
493 void seat_claim_position(Seat
*s
, Session
*session
, unsigned int pos
) {
494 /* with VTs, the position is always the same as the VTnr */
498 if (!GREEDY_REALLOC0(s
->positions
, s
->position_count
, pos
+ 1))
501 seat_evict_position(s
, session
);
503 session
->position
= pos
;
505 s
->positions
[pos
] = session
;
508 static void seat_assign_position(Seat
*s
, Session
*session
) {
511 if (session
->position
> 0)
514 for (pos
= 1; pos
< s
->position_count
; ++pos
)
515 if (!s
->positions
[pos
])
518 seat_claim_position(s
, session
, pos
);
521 int seat_attach_session(Seat
*s
, Session
*session
) {
524 assert(!session
->seat
);
526 if (!seat_has_vts(s
) != !session
->vtnr
)
530 LIST_PREPEND(sessions_by_seat
, s
->sessions
, session
);
531 seat_assign_position(s
, session
);
533 /* On seats with VTs, the VT logic defines which session is active. On
534 * seats without VTs, we automatically activate new sessions. */
535 if (!seat_has_vts(s
))
536 seat_set_active(s
, session
);
541 void seat_complete_switch(Seat
*s
) {
546 /* if no session-switch is pending or if it got canceled, do nothing */
547 if (!s
->pending_switch
)
550 session
= TAKE_PTR(s
->pending_switch
);
552 seat_set_active(s
, session
);
555 bool seat_has_vts(Seat
*s
) {
558 return seat_is_seat0(s
) && s
->manager
->console_active_fd
>= 0;
561 bool seat_is_seat0(Seat
*s
) {
564 return s
->manager
->seat0
== s
;
567 bool seat_can_multi_session(Seat
*s
) {
570 return seat_has_vts(s
);
573 bool seat_can_tty(Seat
*s
) {
576 return seat_has_vts(s
);
579 bool seat_has_master_device(Seat
*s
) {
582 /* device list is ordered by "master" flag */
583 return !!s
->devices
&& s
->devices
->master
;
586 bool seat_can_graphical(Seat
*s
) {
589 return seat_has_master_device(s
);
592 int seat_get_idle_hint(Seat
*s
, dual_timestamp
*t
) {
594 bool idle_hint
= true;
595 dual_timestamp ts
= DUAL_TIMESTAMP_NULL
;
599 LIST_FOREACH(sessions_by_seat
, session
, s
->sessions
) {
603 ih
= session_get_idle_hint(session
, &k
);
609 if (k
.monotonic
> ts
.monotonic
)
615 } else if (idle_hint
) {
617 if (k
.monotonic
> ts
.monotonic
)
628 bool seat_may_gc(Seat
*s
, bool drop_not_started
) {
631 if (drop_not_started
&& !s
->started
)
634 if (seat_is_seat0(s
))
637 return !seat_has_master_device(s
);
640 void seat_add_to_gc_queue(Seat
*s
) {
646 LIST_PREPEND(gc_queue
, s
->manager
->seat_gc_queue
, s
);
647 s
->in_gc_queue
= true;
650 static bool seat_name_valid_char(char c
) {
652 (c
>= 'a' && c
<= 'z') ||
653 (c
>= 'A' && c
<= 'Z') ||
654 (c
>= '0' && c
<= '9') ||
658 bool seat_name_is_valid(const char *name
) {
663 if (!startswith(name
, "seat"))
669 for (p
= name
; *p
; p
++)
670 if (!seat_name_valid_char(*p
))
673 if (strlen(name
) > 255)