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1 | /*** | |
2 | This file is part of systemd. | |
3 | ||
4 | Copyright 2011 Lennart Poettering | |
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 <http://www.gnu.org/licenses/>. | |
18 | ***/ | |
19 | ||
20 | #include <errno.h> | |
21 | #include <fcntl.h> | |
22 | #include <string.h> | |
23 | #include <unistd.h> | |
24 | ||
25 | #include "sd-messages.h" | |
26 | ||
27 | #include "alloc-util.h" | |
28 | #include "fd-util.h" | |
29 | #include "fileio.h" | |
30 | #include "formats-util.h" | |
31 | #include "logind-acl.h" | |
32 | #include "logind-seat.h" | |
33 | #include "mkdir.h" | |
34 | #include "parse-util.h" | |
35 | #include "stdio-util.h" | |
36 | #include "string-util.h" | |
37 | #include "terminal-util.h" | |
38 | #include "util.h" | |
39 | ||
40 | Seat *seat_new(Manager *m, const char *id) { | |
41 | Seat *s; | |
42 | ||
43 | assert(m); | |
44 | assert(id); | |
45 | ||
46 | s = new0(Seat, 1); | |
47 | if (!s) | |
48 | return NULL; | |
49 | ||
50 | s->state_file = strappend("/run/systemd/seats/", id); | |
51 | if (!s->state_file) | |
52 | return mfree(s); | |
53 | ||
54 | s->id = basename(s->state_file); | |
55 | s->manager = m; | |
56 | ||
57 | if (hashmap_put(m->seats, s->id, s) < 0) { | |
58 | free(s->state_file); | |
59 | return mfree(s); | |
60 | } | |
61 | ||
62 | return s; | |
63 | } | |
64 | ||
65 | void seat_free(Seat *s) { | |
66 | assert(s); | |
67 | ||
68 | if (s->in_gc_queue) | |
69 | LIST_REMOVE(gc_queue, s->manager->seat_gc_queue, s); | |
70 | ||
71 | while (s->sessions) | |
72 | session_free(s->sessions); | |
73 | ||
74 | assert(!s->active); | |
75 | ||
76 | while (s->devices) | |
77 | device_free(s->devices); | |
78 | ||
79 | hashmap_remove(s->manager->seats, s->id); | |
80 | ||
81 | free(s->positions); | |
82 | free(s->state_file); | |
83 | free(s); | |
84 | } | |
85 | ||
86 | int seat_save(Seat *s) { | |
87 | _cleanup_free_ char *temp_path = NULL; | |
88 | _cleanup_fclose_ FILE *f = NULL; | |
89 | int r; | |
90 | ||
91 | assert(s); | |
92 | ||
93 | if (!s->started) | |
94 | return 0; | |
95 | ||
96 | r = mkdir_safe_label("/run/systemd/seats", 0755, 0, 0); | |
97 | if (r < 0) | |
98 | goto fail; | |
99 | ||
100 | r = fopen_temporary(s->state_file, &f, &temp_path); | |
101 | if (r < 0) | |
102 | goto fail; | |
103 | ||
104 | fchmod(fileno(f), 0644); | |
105 | ||
106 | fprintf(f, | |
107 | "# This is private data. Do not parse.\n" | |
108 | "IS_SEAT0=%i\n" | |
109 | "CAN_MULTI_SESSION=%i\n" | |
110 | "CAN_TTY=%i\n" | |
111 | "CAN_GRAPHICAL=%i\n", | |
112 | seat_is_seat0(s), | |
113 | seat_can_multi_session(s), | |
114 | seat_can_tty(s), | |
115 | seat_can_graphical(s)); | |
116 | ||
117 | if (s->active) { | |
118 | assert(s->active->user); | |
119 | ||
120 | fprintf(f, | |
121 | "ACTIVE=%s\n" | |
122 | "ACTIVE_UID="UID_FMT"\n", | |
123 | s->active->id, | |
124 | s->active->user->uid); | |
125 | } | |
126 | ||
127 | if (s->sessions) { | |
128 | Session *i; | |
129 | ||
130 | fputs("SESSIONS=", f); | |
131 | LIST_FOREACH(sessions_by_seat, i, s->sessions) { | |
132 | fprintf(f, | |
133 | "%s%c", | |
134 | i->id, | |
135 | i->sessions_by_seat_next ? ' ' : '\n'); | |
136 | } | |
137 | ||
138 | fputs("UIDS=", f); | |
139 | LIST_FOREACH(sessions_by_seat, i, s->sessions) | |
140 | fprintf(f, | |
141 | UID_FMT"%c", | |
142 | i->user->uid, | |
143 | i->sessions_by_seat_next ? ' ' : '\n'); | |
144 | } | |
145 | ||
146 | r = fflush_and_check(f); | |
147 | if (r < 0) | |
148 | goto fail; | |
149 | ||
150 | if (rename(temp_path, s->state_file) < 0) { | |
151 | r = -errno; | |
152 | goto fail; | |
153 | } | |
154 | ||
155 | return 0; | |
156 | ||
157 | fail: | |
158 | (void) unlink(s->state_file); | |
159 | ||
160 | if (temp_path) | |
161 | (void) unlink(temp_path); | |
162 | ||
163 | return log_error_errno(r, "Failed to save seat data %s: %m", s->state_file); | |
164 | } | |
165 | ||
166 | int seat_load(Seat *s) { | |
167 | assert(s); | |
168 | ||
169 | /* There isn't actually anything to read here ... */ | |
170 | ||
171 | return 0; | |
172 | } | |
173 | ||
174 | static int vt_allocate(unsigned int vtnr) { | |
175 | char p[sizeof("/dev/tty") + DECIMAL_STR_MAX(unsigned int)]; | |
176 | _cleanup_close_ int fd = -1; | |
177 | ||
178 | assert(vtnr >= 1); | |
179 | ||
180 | xsprintf(p, "/dev/tty%u", vtnr); | |
181 | fd = open_terminal(p, O_RDWR|O_NOCTTY|O_CLOEXEC); | |
182 | if (fd < 0) | |
183 | return -errno; | |
184 | ||
185 | return 0; | |
186 | } | |
187 | ||
188 | int seat_preallocate_vts(Seat *s) { | |
189 | int r = 0; | |
190 | unsigned i; | |
191 | ||
192 | assert(s); | |
193 | assert(s->manager); | |
194 | ||
195 | log_debug("Preallocating VTs..."); | |
196 | ||
197 | if (s->manager->n_autovts <= 0) | |
198 | return 0; | |
199 | ||
200 | if (!seat_has_vts(s)) | |
201 | return 0; | |
202 | ||
203 | for (i = 1; i <= s->manager->n_autovts; i++) { | |
204 | int q; | |
205 | ||
206 | q = vt_allocate(i); | |
207 | if (q < 0) { | |
208 | log_error_errno(q, "Failed to preallocate VT %u: %m", i); | |
209 | r = q; | |
210 | } | |
211 | } | |
212 | ||
213 | return r; | |
214 | } | |
215 | ||
216 | int seat_apply_acls(Seat *s, Session *old_active) { | |
217 | int r; | |
218 | ||
219 | assert(s); | |
220 | ||
221 | r = devnode_acl_all(s->manager->udev, | |
222 | s->id, | |
223 | false, | |
224 | !!old_active, old_active ? old_active->user->uid : 0, | |
225 | !!s->active, s->active ? s->active->user->uid : 0); | |
226 | ||
227 | if (r < 0) | |
228 | log_error_errno(r, "Failed to apply ACLs: %m"); | |
229 | ||
230 | return r; | |
231 | } | |
232 | ||
233 | int seat_set_active(Seat *s, Session *session) { | |
234 | Session *old_active; | |
235 | ||
236 | assert(s); | |
237 | assert(!session || session->seat == s); | |
238 | ||
239 | if (session == s->active) | |
240 | return 0; | |
241 | ||
242 | old_active = s->active; | |
243 | s->active = session; | |
244 | ||
245 | if (old_active) { | |
246 | session_device_pause_all(old_active); | |
247 | session_send_changed(old_active, "Active", NULL); | |
248 | } | |
249 | ||
250 | seat_apply_acls(s, old_active); | |
251 | ||
252 | if (session && session->started) { | |
253 | session_send_changed(session, "Active", NULL); | |
254 | session_device_resume_all(session); | |
255 | } | |
256 | ||
257 | if (!session || session->started) | |
258 | seat_send_changed(s, "ActiveSession", NULL); | |
259 | ||
260 | seat_save(s); | |
261 | ||
262 | if (session) { | |
263 | session_save(session); | |
264 | user_save(session->user); | |
265 | } | |
266 | ||
267 | if (old_active) { | |
268 | session_save(old_active); | |
269 | if (!session || session->user != old_active->user) | |
270 | user_save(old_active->user); | |
271 | } | |
272 | ||
273 | return 0; | |
274 | } | |
275 | ||
276 | int seat_switch_to(Seat *s, unsigned int num) { | |
277 | /* Public session positions skip 0 (there is only F1-F12). Maybe it | |
278 | * will get reassigned in the future, so return error for now. */ | |
279 | if (num == 0) | |
280 | return -EINVAL; | |
281 | ||
282 | if (num >= s->position_count || !s->positions[num]) { | |
283 | /* allow switching to unused VTs to trigger auto-activate */ | |
284 | if (seat_has_vts(s) && num < 64) | |
285 | return chvt(num); | |
286 | ||
287 | return -EINVAL; | |
288 | } | |
289 | ||
290 | return session_activate(s->positions[num]); | |
291 | } | |
292 | ||
293 | int seat_switch_to_next(Seat *s) { | |
294 | unsigned int start, i; | |
295 | ||
296 | if (s->position_count == 0) | |
297 | return -EINVAL; | |
298 | ||
299 | start = 1; | |
300 | if (s->active && s->active->position > 0) | |
301 | start = s->active->position; | |
302 | ||
303 | for (i = start + 1; i < s->position_count; ++i) | |
304 | if (s->positions[i]) | |
305 | return session_activate(s->positions[i]); | |
306 | ||
307 | for (i = 1; i < start; ++i) | |
308 | if (s->positions[i]) | |
309 | return session_activate(s->positions[i]); | |
310 | ||
311 | return -EINVAL; | |
312 | } | |
313 | ||
314 | int seat_switch_to_previous(Seat *s) { | |
315 | unsigned int start, i; | |
316 | ||
317 | if (s->position_count == 0) | |
318 | return -EINVAL; | |
319 | ||
320 | start = 1; | |
321 | if (s->active && s->active->position > 0) | |
322 | start = s->active->position; | |
323 | ||
324 | for (i = start - 1; i > 0; --i) | |
325 | if (s->positions[i]) | |
326 | return session_activate(s->positions[i]); | |
327 | ||
328 | for (i = s->position_count - 1; i > start; --i) | |
329 | if (s->positions[i]) | |
330 | return session_activate(s->positions[i]); | |
331 | ||
332 | return -EINVAL; | |
333 | } | |
334 | ||
335 | int seat_active_vt_changed(Seat *s, unsigned int vtnr) { | |
336 | Session *i, *new_active = NULL; | |
337 | int r; | |
338 | ||
339 | assert(s); | |
340 | assert(vtnr >= 1); | |
341 | ||
342 | if (!seat_has_vts(s)) | |
343 | return -EINVAL; | |
344 | ||
345 | log_debug("VT changed to %u", vtnr); | |
346 | ||
347 | /* we might have earlier closing sessions on the same VT, so try to | |
348 | * find a running one first */ | |
349 | LIST_FOREACH(sessions_by_seat, i, s->sessions) | |
350 | if (i->vtnr == vtnr && !i->stopping) { | |
351 | new_active = i; | |
352 | break; | |
353 | } | |
354 | ||
355 | if (!new_active) { | |
356 | /* no running one? then we can't decide which one is the | |
357 | * active one, let the first one win */ | |
358 | LIST_FOREACH(sessions_by_seat, i, s->sessions) | |
359 | if (i->vtnr == vtnr) { | |
360 | new_active = i; | |
361 | break; | |
362 | } | |
363 | } | |
364 | ||
365 | r = seat_set_active(s, new_active); | |
366 | manager_spawn_autovt(s->manager, vtnr); | |
367 | ||
368 | return r; | |
369 | } | |
370 | ||
371 | int seat_read_active_vt(Seat *s) { | |
372 | char t[64]; | |
373 | ssize_t k; | |
374 | unsigned int vtnr; | |
375 | int r; | |
376 | ||
377 | assert(s); | |
378 | ||
379 | if (!seat_has_vts(s)) | |
380 | return 0; | |
381 | ||
382 | lseek(s->manager->console_active_fd, SEEK_SET, 0); | |
383 | ||
384 | k = read(s->manager->console_active_fd, t, sizeof(t)-1); | |
385 | if (k <= 0) { | |
386 | log_error("Failed to read current console: %s", k < 0 ? strerror(-errno) : "EOF"); | |
387 | return k < 0 ? -errno : -EIO; | |
388 | } | |
389 | ||
390 | t[k] = 0; | |
391 | truncate_nl(t); | |
392 | ||
393 | if (!startswith(t, "tty")) { | |
394 | log_error("Hm, /sys/class/tty/tty0/active is badly formatted."); | |
395 | return -EIO; | |
396 | } | |
397 | ||
398 | r = safe_atou(t+3, &vtnr); | |
399 | if (r < 0) { | |
400 | log_error("Failed to parse VT number %s", t+3); | |
401 | return r; | |
402 | } | |
403 | ||
404 | if (!vtnr) { | |
405 | log_error("VT number invalid: %s", t+3); | |
406 | return -EIO; | |
407 | } | |
408 | ||
409 | return seat_active_vt_changed(s, vtnr); | |
410 | } | |
411 | ||
412 | int seat_start(Seat *s) { | |
413 | assert(s); | |
414 | ||
415 | if (s->started) | |
416 | return 0; | |
417 | ||
418 | log_struct(LOG_INFO, | |
419 | LOG_MESSAGE_ID(SD_MESSAGE_SEAT_START), | |
420 | "SEAT_ID=%s", s->id, | |
421 | LOG_MESSAGE("New seat %s.", s->id), | |
422 | NULL); | |
423 | ||
424 | /* Initialize VT magic stuff */ | |
425 | seat_preallocate_vts(s); | |
426 | ||
427 | /* Read current VT */ | |
428 | seat_read_active_vt(s); | |
429 | ||
430 | s->started = true; | |
431 | ||
432 | /* Save seat data */ | |
433 | seat_save(s); | |
434 | ||
435 | seat_send_signal(s, true); | |
436 | ||
437 | return 0; | |
438 | } | |
439 | ||
440 | int seat_stop(Seat *s, bool force) { | |
441 | int r = 0; | |
442 | ||
443 | assert(s); | |
444 | ||
445 | if (s->started) | |
446 | log_struct(LOG_INFO, | |
447 | LOG_MESSAGE_ID(SD_MESSAGE_SEAT_STOP), | |
448 | "SEAT_ID=%s", s->id, | |
449 | LOG_MESSAGE("Removed seat %s.", s->id), | |
450 | NULL); | |
451 | ||
452 | seat_stop_sessions(s, force); | |
453 | ||
454 | unlink(s->state_file); | |
455 | seat_add_to_gc_queue(s); | |
456 | ||
457 | if (s->started) | |
458 | seat_send_signal(s, false); | |
459 | ||
460 | s->started = false; | |
461 | ||
462 | return r; | |
463 | } | |
464 | ||
465 | int seat_stop_sessions(Seat *s, bool force) { | |
466 | Session *session; | |
467 | int r = 0, k; | |
468 | ||
469 | assert(s); | |
470 | ||
471 | LIST_FOREACH(sessions_by_seat, session, s->sessions) { | |
472 | k = session_stop(session, force); | |
473 | if (k < 0) | |
474 | r = k; | |
475 | } | |
476 | ||
477 | return r; | |
478 | } | |
479 | ||
480 | void seat_evict_position(Seat *s, Session *session) { | |
481 | Session *iter; | |
482 | unsigned int pos = session->position; | |
483 | ||
484 | session->position = 0; | |
485 | ||
486 | if (pos == 0) | |
487 | return; | |
488 | ||
489 | if (pos < s->position_count && s->positions[pos] == session) { | |
490 | s->positions[pos] = NULL; | |
491 | ||
492 | /* There might be another session claiming the same | |
493 | * position (eg., during gdm->session transition), so let's look | |
494 | * for it and set it on the free slot. */ | |
495 | LIST_FOREACH(sessions_by_seat, iter, s->sessions) { | |
496 | if (iter->position == pos && session_get_state(iter) != SESSION_CLOSING) { | |
497 | s->positions[pos] = iter; | |
498 | break; | |
499 | } | |
500 | } | |
501 | } | |
502 | } | |
503 | ||
504 | void seat_claim_position(Seat *s, Session *session, unsigned int pos) { | |
505 | /* with VTs, the position is always the same as the VTnr */ | |
506 | if (seat_has_vts(s)) | |
507 | pos = session->vtnr; | |
508 | ||
509 | if (!GREEDY_REALLOC0(s->positions, s->position_count, pos + 1)) | |
510 | return; | |
511 | ||
512 | seat_evict_position(s, session); | |
513 | ||
514 | session->position = pos; | |
515 | if (pos > 0) | |
516 | s->positions[pos] = session; | |
517 | } | |
518 | ||
519 | static void seat_assign_position(Seat *s, Session *session) { | |
520 | unsigned int pos; | |
521 | ||
522 | if (session->position > 0) | |
523 | return; | |
524 | ||
525 | for (pos = 1; pos < s->position_count; ++pos) | |
526 | if (!s->positions[pos]) | |
527 | break; | |
528 | ||
529 | seat_claim_position(s, session, pos); | |
530 | } | |
531 | ||
532 | int seat_attach_session(Seat *s, Session *session) { | |
533 | assert(s); | |
534 | assert(session); | |
535 | assert(!session->seat); | |
536 | ||
537 | if (!seat_has_vts(s) != !session->vtnr) | |
538 | return -EINVAL; | |
539 | ||
540 | session->seat = s; | |
541 | LIST_PREPEND(sessions_by_seat, s->sessions, session); | |
542 | seat_assign_position(s, session); | |
543 | ||
544 | seat_send_changed(s, "Sessions", NULL); | |
545 | ||
546 | /* On seats with VTs, the VT logic defines which session is active. On | |
547 | * seats without VTs, we automatically activate new sessions. */ | |
548 | if (!seat_has_vts(s)) | |
549 | seat_set_active(s, session); | |
550 | ||
551 | return 0; | |
552 | } | |
553 | ||
554 | void seat_complete_switch(Seat *s) { | |
555 | Session *session; | |
556 | ||
557 | assert(s); | |
558 | ||
559 | /* if no session-switch is pending or if it got canceled, do nothing */ | |
560 | if (!s->pending_switch) | |
561 | return; | |
562 | ||
563 | session = s->pending_switch; | |
564 | s->pending_switch = NULL; | |
565 | ||
566 | seat_set_active(s, session); | |
567 | } | |
568 | ||
569 | bool seat_has_vts(Seat *s) { | |
570 | assert(s); | |
571 | ||
572 | return seat_is_seat0(s) && s->manager->console_active_fd >= 0; | |
573 | } | |
574 | ||
575 | bool seat_is_seat0(Seat *s) { | |
576 | assert(s); | |
577 | ||
578 | return s->manager->seat0 == s; | |
579 | } | |
580 | ||
581 | bool seat_can_multi_session(Seat *s) { | |
582 | assert(s); | |
583 | ||
584 | return seat_has_vts(s); | |
585 | } | |
586 | ||
587 | bool seat_can_tty(Seat *s) { | |
588 | assert(s); | |
589 | ||
590 | return seat_has_vts(s); | |
591 | } | |
592 | ||
593 | bool seat_has_master_device(Seat *s) { | |
594 | assert(s); | |
595 | ||
596 | /* device list is ordered by "master" flag */ | |
597 | return !!s->devices && s->devices->master; | |
598 | } | |
599 | ||
600 | bool seat_can_graphical(Seat *s) { | |
601 | assert(s); | |
602 | ||
603 | return seat_has_master_device(s); | |
604 | } | |
605 | ||
606 | int seat_get_idle_hint(Seat *s, dual_timestamp *t) { | |
607 | Session *session; | |
608 | bool idle_hint = true; | |
609 | dual_timestamp ts = DUAL_TIMESTAMP_NULL; | |
610 | ||
611 | assert(s); | |
612 | ||
613 | LIST_FOREACH(sessions_by_seat, session, s->sessions) { | |
614 | dual_timestamp k; | |
615 | int ih; | |
616 | ||
617 | ih = session_get_idle_hint(session, &k); | |
618 | if (ih < 0) | |
619 | return ih; | |
620 | ||
621 | if (!ih) { | |
622 | if (!idle_hint) { | |
623 | if (k.monotonic > ts.monotonic) | |
624 | ts = k; | |
625 | } else { | |
626 | idle_hint = false; | |
627 | ts = k; | |
628 | } | |
629 | } else if (idle_hint) { | |
630 | ||
631 | if (k.monotonic > ts.monotonic) | |
632 | ts = k; | |
633 | } | |
634 | } | |
635 | ||
636 | if (t) | |
637 | *t = ts; | |
638 | ||
639 | return idle_hint; | |
640 | } | |
641 | ||
642 | bool seat_check_gc(Seat *s, bool drop_not_started) { | |
643 | assert(s); | |
644 | ||
645 | if (drop_not_started && !s->started) | |
646 | return false; | |
647 | ||
648 | if (seat_is_seat0(s)) | |
649 | return true; | |
650 | ||
651 | return seat_has_master_device(s); | |
652 | } | |
653 | ||
654 | void seat_add_to_gc_queue(Seat *s) { | |
655 | assert(s); | |
656 | ||
657 | if (s->in_gc_queue) | |
658 | return; | |
659 | ||
660 | LIST_PREPEND(gc_queue, s->manager->seat_gc_queue, s); | |
661 | s->in_gc_queue = true; | |
662 | } | |
663 | ||
664 | static bool seat_name_valid_char(char c) { | |
665 | return | |
666 | (c >= 'a' && c <= 'z') || | |
667 | (c >= 'A' && c <= 'Z') || | |
668 | (c >= '0' && c <= '9') || | |
669 | c == '-' || | |
670 | c == '_'; | |
671 | } | |
672 | ||
673 | bool seat_name_is_valid(const char *name) { | |
674 | const char *p; | |
675 | ||
676 | assert(name); | |
677 | ||
678 | if (!startswith(name, "seat")) | |
679 | return false; | |
680 | ||
681 | if (!name[4]) | |
682 | return false; | |
683 | ||
684 | for (p = name; *p; p++) | |
685 | if (!seat_name_valid_char(*p)) | |
686 | return false; | |
687 | ||
688 | if (strlen(name) > 255) | |
689 | return false; | |
690 | ||
691 | return true; | |
692 | } |