]> git.ipfire.org Git - thirdparty/systemd.git/blob - dbus.c
dbus: send out signals when units/jobs come, go and change
[thirdparty/systemd.git] / dbus.c
1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
2
3 /***
4 This file is part of systemd.
5
6 Copyright 2010 Lennart Poettering
7
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
12
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
20 ***/
21
22 #include <dbus/dbus.h>
23
24 #include <sys/epoll.h>
25 #include <sys/timerfd.h>
26 #include <errno.h>
27 #include <unistd.h>
28
29 #include "dbus.h"
30 #include "log.h"
31 #include "strv.h"
32
33 static void bus_dispatch_status(DBusConnection *bus, DBusDispatchStatus status, void *data) {
34 Manager *m = data;
35
36 assert(bus);
37 assert(m);
38
39 m->request_bus_dispatch = status != DBUS_DISPATCH_COMPLETE;
40 }
41
42 static uint32_t bus_flags_to_events(DBusWatch *bus_watch) {
43 unsigned flags;
44 uint32_t events = 0;
45
46 assert(bus_watch);
47
48 /* no watch flags for disabled watches */
49 if (!dbus_watch_get_enabled(bus_watch))
50 return 0;
51
52 flags = dbus_watch_get_flags(bus_watch);
53
54 if (flags & DBUS_WATCH_READABLE)
55 events |= EPOLLIN;
56 if (flags & DBUS_WATCH_WRITABLE)
57 events |= EPOLLOUT;
58
59 return events | EPOLLHUP | EPOLLERR;
60 }
61
62 static unsigned events_to_bus_flags(uint32_t events) {
63 unsigned flags = 0;
64
65 if (events & EPOLLIN)
66 flags |= DBUS_WATCH_READABLE;
67 if (events & EPOLLOUT)
68 flags |= DBUS_WATCH_WRITABLE;
69 if (events & EPOLLHUP)
70 flags |= DBUS_WATCH_HANGUP;
71 if (events & EPOLLERR)
72 flags |= DBUS_WATCH_ERROR;
73
74 return flags;
75 }
76
77 void bus_watch_event(Manager *m, Watch *w, int events) {
78 assert(m);
79 assert(w);
80
81 /* This is called by the event loop whenever there is
82 * something happening on D-Bus' file handles. */
83
84 if (!(dbus_watch_get_enabled(w->data.bus_watch)))
85 return;
86
87 dbus_watch_handle(w->data.bus_watch, events_to_bus_flags(events));
88 }
89
90 static dbus_bool_t bus_add_watch(DBusWatch *bus_watch, void *data) {
91 Manager *m = data;
92 Watch *w;
93 struct epoll_event ev;
94
95 assert(bus_watch);
96 assert(m);
97
98 if (!(w = new0(Watch, 1)))
99 return FALSE;
100
101 w->fd = dbus_watch_get_unix_fd(bus_watch);
102 w->type = WATCH_DBUS_WATCH;
103 w->data.bus_watch = bus_watch;
104
105 zero(ev);
106 ev.events = bus_flags_to_events(bus_watch);
107 ev.data.ptr = w;
108
109 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, w->fd, &ev) < 0) {
110
111 if (errno != EEXIST) {
112 free(w);
113 return FALSE;
114 }
115
116 /* Hmm, bloody D-Bus creates multiple watches on the
117 * same fd. epoll() does not like that. As a dirty
118 * hack we simply dup() the fd and hence get a second
119 * one we can safely add to the epoll(). */
120
121 if ((w->fd = dup(w->fd)) < 0) {
122 free(w);
123 return FALSE;
124 }
125
126 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, w->fd, &ev) < 0) {
127 free(w);
128 close_nointr_nofail(w->fd);
129 return FALSE;
130 }
131
132 w->fd_is_dupped = true;
133 }
134
135 dbus_watch_set_data(bus_watch, w, NULL);
136
137 return TRUE;
138 }
139
140 static void bus_remove_watch(DBusWatch *bus_watch, void *data) {
141 Manager *m = data;
142 Watch *w;
143
144 assert(bus_watch);
145 assert(m);
146
147 if (!(w = dbus_watch_get_data(bus_watch)))
148 return;
149
150 assert(w->type == WATCH_DBUS_WATCH);
151 assert_se(epoll_ctl(m->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
152
153 if (w->fd_is_dupped)
154 close_nointr_nofail(w->fd);
155
156 free(w);
157 }
158
159 static void bus_toggle_watch(DBusWatch *bus_watch, void *data) {
160 Manager *m = data;
161 Watch *w;
162 struct epoll_event ev;
163
164 assert(bus_watch);
165 assert(m);
166
167 assert_se(w = dbus_watch_get_data(bus_watch));
168 assert(w->type == WATCH_DBUS_WATCH);
169
170 zero(ev);
171 ev.events = bus_flags_to_events(bus_watch);
172 ev.data.ptr = w;
173
174 assert_se(epoll_ctl(m->epoll_fd, EPOLL_CTL_MOD, w->fd, &ev) == 0);
175 }
176
177 static int bus_timeout_arm(Manager *m, Watch *w) {
178 struct itimerspec its;
179
180 assert(m);
181 assert(w);
182
183 zero(its);
184
185 if (dbus_timeout_get_enabled(w->data.bus_timeout)) {
186 timespec_store(&its.it_value, dbus_timeout_get_interval(w->data.bus_timeout) * USEC_PER_MSEC);
187 its.it_interval = its.it_interval;
188 }
189
190 if (timerfd_settime(w->fd, 0, &its, NULL) < 0)
191 return -errno;
192
193 return 0;
194 }
195
196 void bus_timeout_event(Manager *m, Watch *w, int events) {
197 assert(m);
198 assert(w);
199
200 /* This is called by the event loop whenever there is
201 * something happening on D-Bus' file handles. */
202
203 if (!(dbus_timeout_get_enabled(w->data.bus_timeout)))
204 return;
205
206 dbus_timeout_handle(w->data.bus_timeout);
207 }
208
209 static dbus_bool_t bus_add_timeout(DBusTimeout *timeout, void *data) {
210 Manager *m = data;
211 Watch *w;
212 struct epoll_event ev;
213
214 assert(timeout);
215 assert(m);
216
217 if (!(w = new0(Watch, 1)))
218 return FALSE;
219
220 if (!(w->fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
221 goto fail;
222
223 w->type = WATCH_DBUS_TIMEOUT;
224 w->data.bus_timeout = timeout;
225
226 if (bus_timeout_arm(m, w) < 0)
227 goto fail;
228
229 zero(ev);
230 ev.events = EPOLLIN;
231 ev.data.ptr = w;
232
233 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, w->fd, &ev) < 0)
234 goto fail;
235
236 dbus_timeout_set_data(timeout, w, NULL);
237
238 return TRUE;
239
240 fail:
241 if (w->fd >= 0)
242 close_nointr_nofail(w->fd);
243
244 free(w);
245 return FALSE;
246 }
247
248 static void bus_remove_timeout(DBusTimeout *timeout, void *data) {
249 Manager *m = data;
250 Watch *w;
251
252 assert(timeout);
253 assert(m);
254
255 if (!(w = dbus_timeout_get_data(timeout)))
256 return;
257
258 assert(w->type == WATCH_DBUS_TIMEOUT);
259 assert_se(epoll_ctl(m->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
260 close_nointr_nofail(w->fd);
261 free(w);
262 }
263
264 static void bus_toggle_timeout(DBusTimeout *timeout, void *data) {
265 Manager *m = data;
266 Watch *w;
267 int r;
268
269 assert(timeout);
270 assert(m);
271
272 assert_se(w = dbus_timeout_get_data(timeout));
273 assert(w->type == WATCH_DBUS_TIMEOUT);
274
275 if ((r = bus_timeout_arm(m, w)) < 0)
276 log_error("Failed to rearm timer: %s", strerror(-r));
277 }
278
279 static DBusHandlerResult bus_message_filter(DBusConnection *connection, DBusMessage *message, void *data) {
280 Manager *m = data;
281 DBusError error;
282
283 assert(connection);
284 assert(message);
285 assert(m);
286
287 dbus_error_init(&error);
288
289 /* log_debug("Got D-Bus request: %s.%s() on %s", */
290 /* dbus_message_get_interface(message), */
291 /* dbus_message_get_member(message), */
292 /* dbus_message_get_path(message)); */
293
294 if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected")) {
295 log_error("Warning! D-Bus connection terminated.");
296
297 /* FIXME: we probably should restart D-Bus here */
298
299 } else if (dbus_message_is_signal(message, DBUS_INTERFACE_DBUS, "NameOwnerChanged")) {
300 const char *name, *old, *new;
301
302 if (!dbus_message_get_args(message, &error,
303 DBUS_TYPE_STRING, &name,
304 DBUS_TYPE_STRING, &old,
305 DBUS_TYPE_STRING, &new,
306 DBUS_TYPE_INVALID))
307 log_error("Failed to parse NameOwnerChanged message: %s", error.message);
308 else {
309 if (set_remove(m->subscribed, (char*) name))
310 log_debug("Subscription client vanished: %s (left: %u)", name, set_size(m->subscribed));
311 }
312 }
313
314 dbus_error_free(&error);
315 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
316 }
317
318 unsigned bus_dispatch(Manager *m) {
319 assert(m);
320
321 if (!m->request_bus_dispatch)
322 return 0;
323
324 if (dbus_connection_dispatch(m->bus) == DBUS_DISPATCH_COMPLETE)
325 m->request_bus_dispatch = false;
326
327 return 1;
328 }
329
330 static int request_name(Manager *m) {
331 DBusMessage *message;
332 const char *name = "org.freedesktop.systemd1";
333 uint32_t flags = 0;
334
335 if (!(message = dbus_message_new_method_call(
336 DBUS_SERVICE_DBUS,
337 DBUS_PATH_DBUS,
338 DBUS_INTERFACE_DBUS,
339 "RequestName")))
340 return -ENOMEM;
341
342 if (!dbus_message_append_args(
343 message,
344 DBUS_TYPE_STRING, &name,
345 DBUS_TYPE_UINT32, &flags,
346 DBUS_TYPE_INVALID)) {
347 dbus_message_unref(message);
348 return -ENOMEM;
349 }
350
351 if (!dbus_connection_send(m->bus, message, NULL)) {
352 dbus_message_unref(message);
353 return -ENOMEM;
354 }
355
356 /* We simple ask for the name and don't wait for it. Sooner or
357 * later we'll have it, and we wouldn't know what to do on
358 * error anyway. */
359
360 dbus_message_unref(message);
361
362 return 0;
363 }
364
365 int bus_init(Manager *m) {
366 DBusError error;
367 char *id;
368 int r;
369
370 assert(m);
371
372 if (m->bus)
373 return 0;
374
375 if (!(m->subscribed = set_new(string_hash_func, string_compare_func)))
376 return -ENOMEM;
377
378 dbus_connection_set_change_sigpipe(FALSE);
379
380 dbus_error_init(&error);
381 if (!(m->bus = dbus_bus_get_private(m->is_init ? DBUS_BUS_SYSTEM : DBUS_BUS_SESSION, &error))) {
382 log_error("Failed to get D-Bus connection: %s", error.message);
383 dbus_error_free(&error);
384 return -ECONNREFUSED;
385 }
386
387 dbus_connection_set_exit_on_disconnect(m->bus, FALSE);
388 dbus_connection_set_dispatch_status_function(m->bus, bus_dispatch_status, m, NULL);
389 if (!dbus_connection_set_watch_functions(m->bus, bus_add_watch, bus_remove_watch, bus_toggle_watch, m, NULL) ||
390 !dbus_connection_set_timeout_functions(m->bus, bus_add_timeout, bus_remove_timeout, bus_toggle_timeout, m, NULL) ||
391 !dbus_connection_register_object_path(m->bus, "/org/freedesktop/systemd1", &bus_manager_vtable, m) ||
392 !dbus_connection_register_fallback(m->bus, "/org/freedesktop/systemd1/unit", &bus_unit_vtable, m) ||
393 !dbus_connection_register_fallback(m->bus, "/org/freedesktop/systemd1/job", &bus_job_vtable, m) ||
394 !dbus_connection_add_filter(m->bus, bus_message_filter, m, NULL)) {
395 bus_done(m);
396 return -ENOMEM;
397 }
398
399 dbus_bus_add_match(m->bus,
400 "type='signal',"
401 "sender='"DBUS_SERVICE_DBUS"',"
402 "interface='"DBUS_INTERFACE_DBUS"',"
403 "path='"DBUS_PATH_DBUS"'",
404 &error);
405
406 if (dbus_error_is_set(&error)) {
407 log_error("Failed to register match: %s", error.message);
408 dbus_error_free(&error);
409 bus_done(m);
410 return -ENOMEM;
411 }
412
413 if ((r = request_name(m)) < 0) {
414 bus_done(m);
415 return r;
416 }
417
418 log_debug("Successfully connected to D-Bus bus %s as %s",
419 strnull((id = dbus_connection_get_server_id(m->bus))),
420 strnull(dbus_bus_get_unique_name(m->bus)));
421 dbus_free(id);
422
423 m->request_bus_dispatch = true;
424
425 return 0;
426 }
427
428 void bus_done(Manager *m) {
429 assert(m);
430
431 if (m->bus) {
432 dbus_connection_close(m->bus);
433 dbus_connection_unref(m->bus);
434 m->bus = NULL;
435 }
436
437 if (m->subscribed) {
438 char *c;
439
440 while ((c = set_steal_first(m->subscribed)))
441 free(c);
442
443 set_free(m->subscribed);
444 m->subscribed = NULL;
445 }
446 }
447
448 DBusHandlerResult bus_default_message_handler(Manager *m, DBusMessage *message, const char*introspection, const BusProperty *properties) {
449 DBusError error;
450 DBusMessage *reply = NULL;
451 int r;
452
453 assert(m);
454 assert(message);
455
456 dbus_error_init(&error);
457
458 if (dbus_message_is_method_call(message, "org.freedesktop.DBus.Introspectable", "Introspect") && introspection) {
459
460 if (!(reply = dbus_message_new_method_return(message)))
461 goto oom;
462
463 if (!dbus_message_append_args(reply, DBUS_TYPE_STRING, &introspection, DBUS_TYPE_INVALID))
464 goto oom;
465
466 } else if (dbus_message_is_method_call(message, "org.freedesktop.DBus.Properties", "Get") && properties) {
467 const char *interface, *property;
468 const BusProperty *p;
469
470 if (!dbus_message_get_args(
471 message,
472 &error,
473 DBUS_TYPE_STRING, &interface,
474 DBUS_TYPE_STRING, &property,
475 DBUS_TYPE_INVALID))
476 return bus_send_error_reply(m, message, &error, -EINVAL);
477
478 for (p = properties; p->property; p++)
479 if (streq(p->interface, interface) && streq(p->property, property))
480 break;
481
482 if (p->property) {
483 DBusMessageIter iter, sub;
484
485 if (!(reply = dbus_message_new_method_return(message)))
486 goto oom;
487
488 dbus_message_iter_init_append(reply, &iter);
489
490 if (!dbus_message_iter_open_container(&iter, DBUS_TYPE_VARIANT, p->signature, &sub))
491 goto oom;
492
493 if ((r = p->append(m, &sub, property, p->data)) < 0) {
494
495 if (r == -ENOMEM)
496 goto oom;
497
498 dbus_message_unref(reply);
499 return bus_send_error_reply(m, message, NULL, r);
500 }
501
502 if (!dbus_message_iter_close_container(&iter, &sub))
503 goto oom;
504 }
505 } else if (dbus_message_is_method_call(message, "org.freedesktop.DBus.Properties", "GetAll") && properties) {
506 const char *interface;
507 const BusProperty *p;
508 DBusMessageIter iter, sub, sub2, sub3;
509 bool any = false;
510
511 if (!dbus_message_get_args(
512 message,
513 &error,
514 DBUS_TYPE_STRING, &interface,
515 DBUS_TYPE_INVALID))
516 return bus_send_error_reply(m, message, &error, -EINVAL);
517
518 if (!(reply = dbus_message_new_method_return(message)))
519 goto oom;
520
521 dbus_message_iter_init_append(reply, &iter);
522
523 if (!dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY, "{sv}", &sub))
524 goto oom;
525
526 for (p = properties; p->property; p++) {
527 if (!streq(p->interface, interface))
528 continue;
529
530 if (!dbus_message_iter_open_container(&sub, DBUS_TYPE_DICT_ENTRY, NULL, &sub2) ||
531 !dbus_message_iter_append_basic(&sub2, DBUS_TYPE_STRING, &p->property) ||
532 !dbus_message_iter_open_container(&sub2, DBUS_TYPE_VARIANT, p->signature, &sub3))
533 goto oom;
534
535 if ((r = p->append(m, &sub3, p->property, p->data)) < 0) {
536
537 if (r == -ENOMEM)
538 goto oom;
539
540 dbus_message_unref(reply);
541 return bus_send_error_reply(m, message, NULL, r);
542 }
543
544 if (!dbus_message_iter_close_container(&sub2, &sub3) ||
545 !dbus_message_iter_close_container(&sub, &sub2))
546 goto oom;
547
548 any = true;
549 }
550
551 if (!dbus_message_iter_close_container(&iter, &sub))
552 goto oom;
553 }
554
555 if (reply) {
556 if (!dbus_connection_send(m->bus, reply, NULL))
557 goto oom;
558
559 dbus_message_unref(reply);
560 return DBUS_HANDLER_RESULT_HANDLED;
561 }
562
563 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
564
565 oom:
566 if (reply)
567 dbus_message_unref(reply);
568
569 dbus_error_free(&error);
570
571 return DBUS_HANDLER_RESULT_NEED_MEMORY;
572 }
573
574
575
576 static const char *error_to_dbus(int error) {
577
578 switch(error) {
579
580 case -EINVAL:
581 return DBUS_ERROR_INVALID_ARGS;
582
583 case -ENOMEM:
584 return DBUS_ERROR_NO_MEMORY;
585
586 case -EPERM:
587 case -EACCES:
588 return DBUS_ERROR_ACCESS_DENIED;
589
590 case -ESRCH:
591 return DBUS_ERROR_UNIX_PROCESS_ID_UNKNOWN;
592
593 case -ENOENT:
594 return DBUS_ERROR_FILE_NOT_FOUND;
595
596 case -EEXIST:
597 return DBUS_ERROR_FILE_EXISTS;
598
599 case -ETIMEDOUT:
600 return DBUS_ERROR_TIMEOUT;
601
602 case -EIO:
603 return DBUS_ERROR_IO_ERROR;
604
605 case -ENETRESET:
606 case -ECONNABORTED:
607 case -ECONNRESET:
608 return DBUS_ERROR_DISCONNECTED;
609 }
610
611 return DBUS_ERROR_FAILED;
612 }
613
614 DBusHandlerResult bus_send_error_reply(Manager *m, DBusMessage *message, DBusError *bus_error, int error) {
615 DBusMessage *reply = NULL;
616 const char *name, *text;
617
618 if (bus_error && dbus_error_is_set(bus_error)) {
619 name = bus_error->name;
620 text = bus_error->message;
621 } else {
622 name = error_to_dbus(error);
623 text = strerror(-error);
624 }
625
626 if (!(reply = dbus_message_new_error(message, name, text)))
627 goto oom;
628
629 if (!dbus_connection_send(m->bus, reply, NULL))
630 goto oom;
631
632 dbus_message_unref(reply);
633
634 if (bus_error)
635 dbus_error_free(bus_error);
636
637 return DBUS_HANDLER_RESULT_HANDLED;
638
639 oom:
640 if (reply)
641 dbus_message_unref(reply);
642
643 if (bus_error)
644 dbus_error_free(bus_error);
645
646 return DBUS_HANDLER_RESULT_NEED_MEMORY;
647 }
648
649 int bus_property_append_string(Manager *m, DBusMessageIter *i, const char *property, void *data) {
650 const char *t = data;
651
652 assert(m);
653 assert(i);
654 assert(property);
655
656 if (!t)
657 t = "";
658
659 if (!dbus_message_iter_append_basic(i, DBUS_TYPE_STRING, &t))
660 return -ENOMEM;
661
662 return 0;
663 }
664
665 int bus_property_append_strv(Manager *m, DBusMessageIter *i, const char *property, void *data) {
666 DBusMessageIter sub;
667 char **t = data;
668
669 assert(m);
670 assert(i);
671 assert(property);
672
673 if (!dbus_message_iter_open_container(i, DBUS_TYPE_ARRAY, "s", &sub))
674 return -ENOMEM;
675
676 STRV_FOREACH(t, t)
677 if (!dbus_message_iter_append_basic(&sub, DBUS_TYPE_STRING, t))
678 return -ENOMEM;
679
680 if (!dbus_message_iter_close_container(i, &sub))
681 return -ENOMEM;
682
683 return 0;
684 }
685
686 int bus_property_append_bool(Manager *m, DBusMessageIter *i, const char *property, void *data) {
687 bool *b = data;
688 dbus_bool_t db;
689
690 assert(m);
691 assert(i);
692 assert(property);
693 assert(b);
694
695 db = *b;
696
697 if (!dbus_message_iter_append_basic(i, DBUS_TYPE_BOOLEAN, &db))
698 return -ENOMEM;
699
700 return 0;
701 }
702
703 int bus_property_append_uint64(Manager *m, DBusMessageIter *i, const char *property, void *data) {
704 assert(m);
705 assert(i);
706 assert(property);
707 assert(data);
708
709 if (!dbus_message_iter_append_basic(i, DBUS_TYPE_UINT64, data))
710 return -ENOMEM;
711
712 return 0;
713 }
714
715 int bus_property_append_uint32(Manager *m, DBusMessageIter *i, const char *property, void *data) {
716 assert(m);
717 assert(i);
718 assert(property);
719 assert(data);
720
721 if (!dbus_message_iter_append_basic(i, DBUS_TYPE_UINT32, data))
722 return -ENOMEM;
723
724 return 0;
725 }