chiark / gitweb /
Add short-iso-precise for journalctl output (#5884)
[elogind.git] / src / login / logind-seat.c
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 "format-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 #if 0 /// UNNEEDED by elogind
175 static int vt_allocate(unsigned int vtnr) {
176         char p[sizeof("/dev/tty") + DECIMAL_STR_MAX(unsigned int)];
177         _cleanup_close_ int fd = -1;
178
179         assert(vtnr >= 1);
180
181         xsprintf(p, "/dev/tty%u", vtnr);
182         fd = open_terminal(p, O_RDWR|O_NOCTTY|O_CLOEXEC);
183         if (fd < 0)
184                 return -errno;
185
186         return 0;
187 }
188
189 int seat_preallocate_vts(Seat *s) {
190         int r = 0;
191         unsigned i;
192
193         assert(s);
194         assert(s->manager);
195
196         log_debug("Preallocating VTs...");
197
198         if (s->manager->n_autovts <= 0)
199                 return 0;
200
201         if (!seat_has_vts(s))
202                 return 0;
203
204         for (i = 1; i <= s->manager->n_autovts; i++) {
205                 int q;
206
207                 q = vt_allocate(i);
208                 if (q < 0) {
209                         log_error_errno(q, "Failed to preallocate VT %u: %m", i);
210                         r = q;
211                 }
212         }
213
214         return r;
215 }
216 #endif // 0
217
218 int seat_apply_acls(Seat *s, Session *old_active) {
219         int r;
220
221         assert(s);
222
223         r = devnode_acl_all(s->manager->udev,
224                             s->id,
225                             false,
226                             !!old_active, old_active ? old_active->user->uid : 0,
227                             !!s->active, s->active ? s->active->user->uid : 0);
228
229         if (r < 0)
230                 log_error_errno(r, "Failed to apply ACLs: %m");
231
232         return r;
233 }
234
235 int seat_set_active(Seat *s, Session *session) {
236         Session *old_active;
237
238         assert(s);
239         assert(!session || session->seat == s);
240
241         if (session == s->active)
242                 return 0;
243
244         old_active = s->active;
245         s->active = session;
246
247         if (old_active) {
248                 session_device_pause_all(old_active);
249                 session_send_changed(old_active, "Active", NULL);
250         }
251
252         seat_apply_acls(s, old_active);
253
254         if (session && session->started) {
255                 session_send_changed(session, "Active", NULL);
256                 session_device_resume_all(session);
257         }
258
259         if (!session || session->started)
260                 seat_send_changed(s, "ActiveSession", NULL);
261
262         seat_save(s);
263
264         if (session) {
265                 session_save(session);
266                 user_save(session->user);
267         }
268
269         if (old_active) {
270                 session_save(old_active);
271                 if (!session || session->user != old_active->user)
272                         user_save(old_active->user);
273         }
274
275         return 0;
276 }
277
278 int seat_switch_to(Seat *s, unsigned int num) {
279         /* Public session positions skip 0 (there is only F1-F12). Maybe it
280          * will get reassigned in the future, so return error for now. */
281         if (num == 0)
282                 return -EINVAL;
283
284         if (num >= s->position_count || !s->positions[num]) {
285                 /* allow switching to unused VTs to trigger auto-activate */
286                 if (seat_has_vts(s) && num < 64)
287                         return chvt(num);
288
289                 return -EINVAL;
290         }
291
292         return session_activate(s->positions[num]);
293 }
294
295 int seat_switch_to_next(Seat *s) {
296         unsigned int start, i;
297
298         if (s->position_count == 0)
299                 return -EINVAL;
300
301         start = 1;
302         if (s->active && s->active->position > 0)
303                 start = s->active->position;
304
305         for (i = start + 1; i < s->position_count; ++i)
306                 if (s->positions[i])
307                         return session_activate(s->positions[i]);
308
309         for (i = 1; i < start; ++i)
310                 if (s->positions[i])
311                         return session_activate(s->positions[i]);
312
313         return -EINVAL;
314 }
315
316 int seat_switch_to_previous(Seat *s) {
317         unsigned int start, i;
318
319         if (s->position_count == 0)
320                 return -EINVAL;
321
322         start = 1;
323         if (s->active && s->active->position > 0)
324                 start = s->active->position;
325
326         for (i = start - 1; i > 0; --i)
327                 if (s->positions[i])
328                         return session_activate(s->positions[i]);
329
330         for (i = s->position_count - 1; i > start; --i)
331                 if (s->positions[i])
332                         return session_activate(s->positions[i]);
333
334         return -EINVAL;
335 }
336
337 int seat_active_vt_changed(Seat *s, unsigned int vtnr) {
338         Session *i, *new_active = NULL;
339         int r;
340
341         assert(s);
342         assert(vtnr >= 1);
343
344         if (!seat_has_vts(s))
345                 return -EINVAL;
346
347         log_debug("VT changed to %u", vtnr);
348
349         /* we might have earlier closing sessions on the same VT, so try to
350          * find a running one first */
351         LIST_FOREACH(sessions_by_seat, i, s->sessions)
352                 if (i->vtnr == vtnr && !i->stopping) {
353                         new_active = i;
354                         break;
355                 }
356
357         if (!new_active) {
358                 /* no running one? then we can't decide which one is the
359                  * active one, let the first one win */
360                 LIST_FOREACH(sessions_by_seat, i, s->sessions)
361                         if (i->vtnr == vtnr) {
362                                 new_active = i;
363                                 break;
364                         }
365         }
366
367         r = seat_set_active(s, new_active);
368 #if 0 /// elogind does not spawn autovt
369         manager_spawn_autovt(s->manager, vtnr);
370 #endif // 0
371
372         return r;
373 }
374
375 int seat_read_active_vt(Seat *s) {
376         char t[64];
377         ssize_t k;
378         unsigned int vtnr;
379         int r;
380
381         assert(s);
382
383         if (!seat_has_vts(s))
384                 return 0;
385
386         if (lseek(s->manager->console_active_fd, SEEK_SET, 0) < 0)
387                 return log_error_errno(errno, "lseek on console_active_fd failed: %m");
388
389         k = read(s->manager->console_active_fd, t, sizeof(t)-1);
390         if (k <= 0) {
391                 log_error("Failed to read current console: %s", k < 0 ? strerror(-errno) : "EOF");
392                 return k < 0 ? -errno : -EIO;
393         }
394
395         t[k] = 0;
396         truncate_nl(t);
397
398         if (!startswith(t, "tty")) {
399                 log_error("Hm, /sys/class/tty/tty0/active is badly formatted.");
400                 return -EIO;
401         }
402
403         r = safe_atou(t+3, &vtnr);
404         if (r < 0)
405                 return log_error_errno(r, "Failed to parse VT number \"%s\": %m", t+3);
406
407         if (!vtnr) {
408                 log_error("VT number invalid: %s", t+3);
409                 return -EIO;
410         }
411
412         return seat_active_vt_changed(s, vtnr);
413 }
414
415 int seat_start(Seat *s) {
416         assert(s);
417
418         if (s->started)
419                 return 0;
420
421         log_struct(LOG_INFO,
422                    "MESSAGE_ID=" SD_MESSAGE_SEAT_START_STR,
423                    "SEAT_ID=%s", s->id,
424                    LOG_MESSAGE("New seat %s.", s->id),
425                    NULL);
426
427         /* Initialize VT magic stuff */
428 #if 0 /// elogind does not support autospawning vts
429         seat_preallocate_vts(s);
430 #endif // 0
431
432         /* Read current VT */
433         seat_read_active_vt(s);
434
435         s->started = true;
436
437         /* Save seat data */
438         seat_save(s);
439
440         seat_send_signal(s, true);
441
442         return 0;
443 }
444
445 int seat_stop(Seat *s, bool force) {
446         int r = 0;
447
448         assert(s);
449
450         if (s->started)
451                 log_struct(LOG_INFO,
452                            "MESSAGE_ID=" SD_MESSAGE_SEAT_STOP_STR,
453                            "SEAT_ID=%s", s->id,
454                            LOG_MESSAGE("Removed seat %s.", s->id),
455                            NULL);
456
457         seat_stop_sessions(s, force);
458
459         unlink(s->state_file);
460         seat_add_to_gc_queue(s);
461
462         if (s->started)
463                 seat_send_signal(s, false);
464
465         s->started = false;
466
467         return r;
468 }
469
470 int seat_stop_sessions(Seat *s, bool force) {
471         Session *session;
472         int r = 0, k;
473
474         assert(s);
475
476         LIST_FOREACH(sessions_by_seat, session, s->sessions) {
477                 k = session_stop(session, force);
478                 if (k < 0)
479                         r = k;
480         }
481
482         return r;
483 }
484
485 void seat_evict_position(Seat *s, Session *session) {
486         Session *iter;
487         unsigned int pos = session->position;
488
489         session->position = 0;
490
491         if (pos == 0)
492                 return;
493
494         if (pos < s->position_count && s->positions[pos] == session) {
495                 s->positions[pos] = NULL;
496
497                 /* There might be another session claiming the same
498                  * position (eg., during gdm->session transition), so let's look
499                  * for it and set it on the free slot. */
500                 LIST_FOREACH(sessions_by_seat, iter, s->sessions) {
501                         if (iter->position == pos && session_get_state(iter) != SESSION_CLOSING) {
502                                 s->positions[pos] = iter;
503                                 break;
504                         }
505                 }
506         }
507 }
508
509 void seat_claim_position(Seat *s, Session *session, unsigned int pos) {
510         /* with VTs, the position is always the same as the VTnr */
511         if (seat_has_vts(s))
512                 pos = session->vtnr;
513
514         if (!GREEDY_REALLOC0(s->positions, s->position_count, pos + 1))
515                 return;
516
517         seat_evict_position(s, session);
518
519         session->position = pos;
520         if (pos > 0)
521                 s->positions[pos] = session;
522 }
523
524 static void seat_assign_position(Seat *s, Session *session) {
525         unsigned int pos;
526
527         if (session->position > 0)
528                 return;
529
530         for (pos = 1; pos < s->position_count; ++pos)
531                 if (!s->positions[pos])
532                         break;
533
534         seat_claim_position(s, session, pos);
535 }
536
537 int seat_attach_session(Seat *s, Session *session) {
538         assert(s);
539         assert(session);
540         assert(!session->seat);
541
542         if (!seat_has_vts(s) != !session->vtnr)
543                 return -EINVAL;
544
545         session->seat = s;
546         LIST_PREPEND(sessions_by_seat, s->sessions, session);
547         seat_assign_position(s, session);
548
549         /* On seats with VTs, the VT logic defines which session is active. On
550          * seats without VTs, we automatically activate new sessions. */
551         if (!seat_has_vts(s))
552                 seat_set_active(s, session);
553
554         return 0;
555 }
556
557 void seat_complete_switch(Seat *s) {
558         Session *session;
559
560         assert(s);
561
562         /* if no session-switch is pending or if it got canceled, do nothing */
563         if (!s->pending_switch)
564                 return;
565
566         session = s->pending_switch;
567         s->pending_switch = NULL;
568
569         seat_set_active(s, session);
570 }
571
572 bool seat_has_vts(Seat *s) {
573         assert(s);
574
575         return seat_is_seat0(s) && s->manager->console_active_fd >= 0;
576 }
577
578 bool seat_is_seat0(Seat *s) {
579         assert(s);
580
581         return s->manager->seat0 == s;
582 }
583
584 bool seat_can_multi_session(Seat *s) {
585         assert(s);
586
587         return seat_has_vts(s);
588 }
589
590 bool seat_can_tty(Seat *s) {
591         assert(s);
592
593         return seat_has_vts(s);
594 }
595
596 bool seat_has_master_device(Seat *s) {
597         assert(s);
598
599         /* device list is ordered by "master" flag */
600         return !!s->devices && s->devices->master;
601 }
602
603 bool seat_can_graphical(Seat *s) {
604         assert(s);
605
606         return seat_has_master_device(s);
607 }
608
609 int seat_get_idle_hint(Seat *s, dual_timestamp *t) {
610         Session *session;
611         bool idle_hint = true;
612         dual_timestamp ts = DUAL_TIMESTAMP_NULL;
613
614         assert(s);
615
616         LIST_FOREACH(sessions_by_seat, session, s->sessions) {
617                 dual_timestamp k;
618                 int ih;
619
620                 ih = session_get_idle_hint(session, &k);
621                 if (ih < 0)
622                         return ih;
623
624                 if (!ih) {
625                         if (!idle_hint) {
626                                 if (k.monotonic > ts.monotonic)
627                                         ts = k;
628                         } else {
629                                 idle_hint = false;
630                                 ts = k;
631                         }
632                 } else if (idle_hint) {
633
634                         if (k.monotonic > ts.monotonic)
635                                 ts = k;
636                 }
637         }
638
639         if (t)
640                 *t = ts;
641
642         return idle_hint;
643 }
644
645 bool seat_check_gc(Seat *s, bool drop_not_started) {
646         assert(s);
647
648         if (drop_not_started && !s->started)
649                 return false;
650
651         if (seat_is_seat0(s))
652                 return true;
653
654         return seat_has_master_device(s);
655 }
656
657 void seat_add_to_gc_queue(Seat *s) {
658         assert(s);
659
660         if (s->in_gc_queue)
661                 return;
662
663         LIST_PREPEND(gc_queue, s->manager->seat_gc_queue, s);
664         s->in_gc_queue = true;
665 }
666
667 static bool seat_name_valid_char(char c) {
668         return
669                 (c >= 'a' && c <= 'z') ||
670                 (c >= 'A' && c <= 'Z') ||
671                 (c >= '0' && c <= '9') ||
672                 c == '-' ||
673                 c == '_';
674 }
675
676 bool seat_name_is_valid(const char *name) {
677         const char *p;
678
679         assert(name);
680
681         if (!startswith(name, "seat"))
682                 return false;
683
684         if (!name[4])
685                 return false;
686
687         for (p = name; *p; p++)
688                 if (!seat_name_valid_char(*p))
689                         return false;
690
691         if (strlen(name) > 255)
692                 return false;
693
694         return true;
695 }