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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
8f8f05a9 LP |
2 | /*** |
3 | This file is part of systemd. | |
4 | ||
5 | Copyright 2013 Lennart Poettering | |
6 | ||
7 | systemd is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU Lesser General Public License as published by | |
9 | the Free Software Foundation; either version 2.1 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | systemd is distributed in the hope that it will be useful, but | |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | Lesser General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU Lesser General Public License | |
18 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
19 | ***/ | |
20 | ||
21 | #include "sd-bus.h" | |
3ffd4af2 | 22 | |
b5efdb8a | 23 | #include "alloc-util.h" |
8f8f05a9 LP |
24 | #include "bus-internal.h" |
25 | #include "bus-track.h" | |
3ffd4af2 | 26 | #include "bus-util.h" |
8f8f05a9 | 27 | |
ae1a2efa LP |
28 | struct track_item { |
29 | unsigned n_ref; | |
30 | char *name; | |
31 | sd_bus_slot *slot; | |
32 | }; | |
33 | ||
8f8f05a9 LP |
34 | struct sd_bus_track { |
35 | unsigned n_ref; | |
8b6e65ac | 36 | unsigned n_adding; /* are we in the process of adding a new name? */ |
8f8f05a9 LP |
37 | sd_bus *bus; |
38 | sd_bus_track_handler_t handler; | |
39 | void *userdata; | |
19befb2d | 40 | Hashmap *names; |
8f8f05a9 LP |
41 | LIST_FIELDS(sd_bus_track, queue); |
42 | Iterator iterator; | |
232f3677 LP |
43 | bool in_list:1; /* In bus->tracks? */ |
44 | bool in_queue:1; /* In bus->track_queue? */ | |
ae1a2efa LP |
45 | bool modified:1; |
46 | bool recursive:1; | |
232f3677 LP |
47 | |
48 | LIST_FIELDS(sd_bus_track, tracks); | |
8f8f05a9 LP |
49 | }; |
50 | ||
51 | #define MATCH_PREFIX \ | |
52 | "type='signal'," \ | |
53 | "sender='org.freedesktop.DBus'," \ | |
54 | "path='/org/freedesktop/DBus'," \ | |
55 | "interface='org.freedesktop.DBus'," \ | |
56 | "member='NameOwnerChanged'," \ | |
57 | "arg0='" | |
58 | ||
59 | #define MATCH_SUFFIX \ | |
60 | "'" | |
61 | ||
62 | #define MATCH_FOR_NAME(name) \ | |
63 | ({ \ | |
64 | char *_x; \ | |
65 | size_t _l = strlen(name); \ | |
f8294e41 | 66 | _x = alloca(strlen(MATCH_PREFIX)+_l+strlen(MATCH_SUFFIX)+1); \ |
8f8f05a9 LP |
67 | strcpy(stpcpy(stpcpy(_x, MATCH_PREFIX), name), MATCH_SUFFIX); \ |
68 | _x; \ | |
69 | }) | |
70 | ||
ae1a2efa LP |
71 | static struct track_item* track_item_free(struct track_item *i) { |
72 | ||
73 | if (!i) | |
74 | return NULL; | |
75 | ||
76 | sd_bus_slot_unref(i->slot); | |
77 | free(i->name); | |
6b430fdb | 78 | return mfree(i); |
ae1a2efa LP |
79 | } |
80 | ||
81 | DEFINE_TRIVIAL_CLEANUP_FUNC(struct track_item*, track_item_free); | |
82 | ||
8f8f05a9 LP |
83 | static void bus_track_add_to_queue(sd_bus_track *track) { |
84 | assert(track); | |
85 | ||
8b6e65ac LP |
86 | /* Adds the bus track object to the queue of objects we should dispatch next, subject to a number of |
87 | * conditions. */ | |
88 | ||
89 | /* Already in the queue? */ | |
8f8f05a9 LP |
90 | if (track->in_queue) |
91 | return; | |
92 | ||
8b6e65ac LP |
93 | /* if we are currently in the process of adding a new name, then let's not enqueue this just yet, let's wait |
94 | * until the addition is complete. */ | |
95 | if (track->n_adding > 0) | |
96 | return; | |
97 | ||
98 | /* still referenced? */ | |
99 | if (hashmap_size(track->names) > 0) | |
100 | return; | |
101 | ||
102 | /* Nothing to call? */ | |
8f8f05a9 LP |
103 | if (!track->handler) |
104 | return; | |
105 | ||
232f3677 LP |
106 | /* Already closed? */ |
107 | if (!track->in_list) | |
108 | return; | |
109 | ||
8f8f05a9 LP |
110 | LIST_PREPEND(queue, track->bus->track_queue, track); |
111 | track->in_queue = true; | |
112 | } | |
113 | ||
114 | static void bus_track_remove_from_queue(sd_bus_track *track) { | |
115 | assert(track); | |
116 | ||
117 | if (!track->in_queue) | |
118 | return; | |
119 | ||
120 | LIST_REMOVE(queue, track->bus->track_queue, track); | |
121 | track->in_queue = false; | |
122 | } | |
123 | ||
ae1a2efa LP |
124 | static int bus_track_remove_name_fully(sd_bus_track *track, const char *name) { |
125 | struct track_item *i; | |
126 | ||
127 | assert(track); | |
128 | assert(name); | |
129 | ||
130 | i = hashmap_remove(track->names, name); | |
131 | if (!i) | |
132 | return 0; | |
133 | ||
134 | track_item_free(i); | |
135 | ||
8b6e65ac | 136 | bus_track_add_to_queue(track); |
ae1a2efa LP |
137 | |
138 | track->modified = true; | |
139 | return 1; | |
140 | } | |
141 | ||
8f8f05a9 LP |
142 | _public_ int sd_bus_track_new( |
143 | sd_bus *bus, | |
144 | sd_bus_track **track, | |
145 | sd_bus_track_handler_t handler, | |
146 | void *userdata) { | |
147 | ||
148 | sd_bus_track *t; | |
149 | ||
150 | assert_return(bus, -EINVAL); | |
151 | assert_return(track, -EINVAL); | |
152 | ||
33c62dcb LP |
153 | if (!bus->bus_client) |
154 | return -EINVAL; | |
155 | ||
8f8f05a9 LP |
156 | t = new0(sd_bus_track, 1); |
157 | if (!t) | |
158 | return -ENOMEM; | |
159 | ||
160 | t->n_ref = 1; | |
161 | t->handler = handler; | |
162 | t->userdata = userdata; | |
163 | t->bus = sd_bus_ref(bus); | |
164 | ||
232f3677 LP |
165 | LIST_PREPEND(tracks, bus->tracks, t); |
166 | t->in_list = true; | |
167 | ||
8f8f05a9 LP |
168 | bus_track_add_to_queue(t); |
169 | ||
170 | *track = t; | |
171 | return 0; | |
172 | } | |
173 | ||
174 | _public_ sd_bus_track* sd_bus_track_ref(sd_bus_track *track) { | |
4afd3348 LP |
175 | |
176 | if (!track) | |
177 | return NULL; | |
8f8f05a9 LP |
178 | |
179 | assert(track->n_ref > 0); | |
180 | ||
181 | track->n_ref++; | |
182 | ||
183 | return track; | |
184 | } | |
185 | ||
186 | _public_ sd_bus_track* sd_bus_track_unref(sd_bus_track *track) { | |
ae1a2efa | 187 | struct track_item *i; |
8f8f05a9 LP |
188 | |
189 | if (!track) | |
190 | return NULL; | |
191 | ||
192 | assert(track->n_ref > 0); | |
193 | ||
194 | if (track->n_ref > 1) { | |
313cefa1 | 195 | track->n_ref--; |
8f8f05a9 LP |
196 | return NULL; |
197 | } | |
198 | ||
ae1a2efa LP |
199 | while ((i = hashmap_steal_first(track->names))) |
200 | track_item_free(i); | |
8f8f05a9 | 201 | |
232f3677 LP |
202 | if (track->in_list) |
203 | LIST_REMOVE(tracks, track->bus->tracks, track); | |
204 | ||
8f8f05a9 | 205 | bus_track_remove_from_queue(track); |
19befb2d | 206 | hashmap_free(track->names); |
8f8f05a9 | 207 | sd_bus_unref(track->bus); |
6b430fdb | 208 | return mfree(track); |
8f8f05a9 LP |
209 | } |
210 | ||
19070062 | 211 | static int on_name_owner_changed(sd_bus_message *message, void *userdata, sd_bus_error *error) { |
8f8f05a9 LP |
212 | sd_bus_track *track = userdata; |
213 | const char *name, *old, *new; | |
214 | int r; | |
215 | ||
8f8f05a9 LP |
216 | assert(message); |
217 | assert(track); | |
218 | ||
219 | r = sd_bus_message_read(message, "sss", &name, &old, &new); | |
220 | if (r < 0) | |
221 | return 0; | |
222 | ||
ae1a2efa | 223 | bus_track_remove_name_fully(track, name); |
8f8f05a9 LP |
224 | return 0; |
225 | } | |
226 | ||
227 | _public_ int sd_bus_track_add_name(sd_bus_track *track, const char *name) { | |
ae1a2efa LP |
228 | _cleanup_(track_item_freep) struct track_item *n = NULL; |
229 | struct track_item *i; | |
8f8f05a9 LP |
230 | const char *match; |
231 | int r; | |
232 | ||
233 | assert_return(track, -EINVAL); | |
234 | assert_return(service_name_is_valid(name), -EINVAL); | |
235 | ||
ae1a2efa LP |
236 | i = hashmap_get(track->names, name); |
237 | if (i) { | |
238 | if (track->recursive) { | |
239 | unsigned k = track->n_ref + 1; | |
240 | ||
241 | if (k < track->n_ref) /* Check for overflow */ | |
242 | return -EOVERFLOW; | |
243 | ||
244 | track->n_ref = k; | |
245 | } | |
246 | ||
247 | bus_track_remove_from_queue(track); | |
248 | return 0; | |
249 | } | |
250 | ||
d5099efc | 251 | r = hashmap_ensure_allocated(&track->names, &string_hash_ops); |
8f8f05a9 LP |
252 | if (r < 0) |
253 | return r; | |
254 | ||
ae1a2efa | 255 | n = new0(struct track_item, 1); |
8f8f05a9 LP |
256 | if (!n) |
257 | return -ENOMEM; | |
ae1a2efa LP |
258 | n->name = strdup(name); |
259 | if (!n->name) | |
260 | return -ENOMEM; | |
8f8f05a9 | 261 | |
19befb2d | 262 | /* First, subscribe to this name */ |
ae1a2efa | 263 | match = MATCH_FOR_NAME(name); |
8b6e65ac LP |
264 | |
265 | bus_track_remove_from_queue(track); /* don't dispatch this while we work in it */ | |
266 | ||
267 | track->n_adding++; /* make sure we aren't dispatched while we synchronously add this match */ | |
ae1a2efa | 268 | r = sd_bus_add_match(track->bus, &n->slot, match, on_name_owner_changed, track); |
8b6e65ac LP |
269 | track->n_adding--; |
270 | if (r < 0) { | |
271 | bus_track_add_to_queue(track); | |
19befb2d | 272 | return r; |
8b6e65ac | 273 | } |
19befb2d | 274 | |
ae1a2efa | 275 | r = hashmap_put(track->names, n->name, n); |
8b6e65ac LP |
276 | if (r < 0) { |
277 | bus_track_add_to_queue(track); | |
8f8f05a9 | 278 | return r; |
8b6e65ac | 279 | } |
8f8f05a9 | 280 | |
ae1a2efa | 281 | /* Second, check if it is currently existing, or maybe doesn't, or maybe disappeared already. */ |
8b6e65ac | 282 | track->n_adding++; /* again, make sure this isn't dispatch while we are working in it */ |
ae1a2efa | 283 | r = sd_bus_get_name_creds(track->bus, name, 0, NULL); |
8b6e65ac | 284 | track->n_adding--; |
8f8f05a9 | 285 | if (r < 0) { |
ae1a2efa | 286 | hashmap_remove(track->names, name); |
8b6e65ac | 287 | bus_track_add_to_queue(track); |
8f8f05a9 LP |
288 | return r; |
289 | } | |
290 | ||
ae1a2efa | 291 | n->n_ref = 1; |
8f8f05a9 LP |
292 | n = NULL; |
293 | ||
294 | bus_track_remove_from_queue(track); | |
295 | track->modified = true; | |
296 | ||
297 | return 1; | |
298 | } | |
299 | ||
300 | _public_ int sd_bus_track_remove_name(sd_bus_track *track, const char *name) { | |
ae1a2efa | 301 | struct track_item *i; |
8f8f05a9 LP |
302 | |
303 | assert_return(name, -EINVAL); | |
304 | ||
ae1a2efa | 305 | if (!track) /* Treat a NULL track object as an empty track object */ |
8f8f05a9 LP |
306 | return 0; |
307 | ||
ae1a2efa LP |
308 | if (!track->recursive) |
309 | return bus_track_remove_name_fully(track, name); | |
8f8f05a9 | 310 | |
ae1a2efa LP |
311 | i = hashmap_get(track->names, name); |
312 | if (!i) | |
313 | return -EUNATCH; | |
314 | if (i->n_ref <= 0) | |
315 | return -EUNATCH; | |
8f8f05a9 | 316 | |
ae1a2efa LP |
317 | i->n_ref--; |
318 | ||
319 | if (i->n_ref <= 0) | |
320 | return bus_track_remove_name_fully(track, name); | |
8f8f05a9 LP |
321 | |
322 | return 1; | |
323 | } | |
324 | ||
325 | _public_ unsigned sd_bus_track_count(sd_bus_track *track) { | |
ae1a2efa LP |
326 | |
327 | if (!track) /* Let's consider a NULL object equivalent to an empty object */ | |
8f8f05a9 LP |
328 | return 0; |
329 | ||
ae1a2efa LP |
330 | /* This signature really should have returned an int, so that we can propagate errors. But well, ... Also, note |
331 | * that this returns the number of names being watched, and multiple references to the same name are not | |
332 | * counted. */ | |
333 | ||
19befb2d | 334 | return hashmap_size(track->names); |
8f8f05a9 LP |
335 | } |
336 | ||
337 | _public_ const char* sd_bus_track_contains(sd_bus_track *track, const char *name) { | |
8f8f05a9 LP |
338 | assert_return(name, NULL); |
339 | ||
ae1a2efa LP |
340 | if (!track) /* Let's consider a NULL object equivalent to an empty object */ |
341 | return NULL; | |
342 | ||
19befb2d | 343 | return hashmap_get(track->names, (void*) name) ? name : NULL; |
8f8f05a9 LP |
344 | } |
345 | ||
346 | _public_ const char* sd_bus_track_first(sd_bus_track *track) { | |
19befb2d LP |
347 | const char *n = NULL; |
348 | ||
8f8f05a9 LP |
349 | if (!track) |
350 | return NULL; | |
351 | ||
352 | track->modified = false; | |
4dd6c572 | 353 | track->iterator = ITERATOR_FIRST; |
8f8f05a9 | 354 | |
8927b1da | 355 | hashmap_iterate(track->names, &track->iterator, NULL, (const void**) &n); |
19befb2d | 356 | return n; |
8f8f05a9 LP |
357 | } |
358 | ||
359 | _public_ const char* sd_bus_track_next(sd_bus_track *track) { | |
19befb2d LP |
360 | const char *n = NULL; |
361 | ||
8f8f05a9 LP |
362 | if (!track) |
363 | return NULL; | |
364 | ||
365 | if (track->modified) | |
366 | return NULL; | |
367 | ||
8927b1da | 368 | hashmap_iterate(track->names, &track->iterator, NULL, (const void**) &n); |
19befb2d | 369 | return n; |
8f8f05a9 LP |
370 | } |
371 | ||
372 | _public_ int sd_bus_track_add_sender(sd_bus_track *track, sd_bus_message *m) { | |
373 | const char *sender; | |
374 | ||
375 | assert_return(track, -EINVAL); | |
376 | assert_return(m, -EINVAL); | |
377 | ||
ae1a2efa LP |
378 | if (sd_bus_message_get_bus(m) != track->bus) |
379 | return -EINVAL; | |
380 | ||
8f8f05a9 LP |
381 | sender = sd_bus_message_get_sender(m); |
382 | if (!sender) | |
383 | return -EINVAL; | |
384 | ||
385 | return sd_bus_track_add_name(track, sender); | |
386 | } | |
387 | ||
388 | _public_ int sd_bus_track_remove_sender(sd_bus_track *track, sd_bus_message *m) { | |
389 | const char *sender; | |
390 | ||
8f8f05a9 LP |
391 | assert_return(m, -EINVAL); |
392 | ||
ae1a2efa LP |
393 | if (!track) /* Treat a NULL track object as an empty track object */ |
394 | return 0; | |
395 | ||
396 | if (sd_bus_message_get_bus(m) != track->bus) | |
397 | return -EINVAL; | |
398 | ||
8f8f05a9 LP |
399 | sender = sd_bus_message_get_sender(m); |
400 | if (!sender) | |
401 | return -EINVAL; | |
402 | ||
403 | return sd_bus_track_remove_name(track, sender); | |
404 | } | |
405 | ||
406 | _public_ sd_bus* sd_bus_track_get_bus(sd_bus_track *track) { | |
407 | assert_return(track, NULL); | |
408 | ||
409 | return track->bus; | |
410 | } | |
411 | ||
412 | void bus_track_dispatch(sd_bus_track *track) { | |
413 | int r; | |
414 | ||
415 | assert(track); | |
8f8f05a9 LP |
416 | assert(track->handler); |
417 | ||
418 | bus_track_remove_from_queue(track); | |
419 | ||
420 | sd_bus_track_ref(track); | |
421 | ||
422 | r = track->handler(track, track->userdata); | |
423 | if (r < 0) | |
da927ba9 | 424 | log_debug_errno(r, "Failed to process track handler: %m"); |
8f8f05a9 LP |
425 | else if (r == 0) |
426 | bus_track_add_to_queue(track); | |
427 | ||
428 | sd_bus_track_unref(track); | |
429 | } | |
04552566 | 430 | |
232f3677 LP |
431 | void bus_track_close(sd_bus_track *track) { |
432 | struct track_item *i; | |
433 | ||
434 | assert(track); | |
435 | ||
436 | /* Called whenever our bus connected is closed. If so, and our track object is non-empty, dispatch it | |
437 | * immediately, as we are closing now, but first flush out all names. */ | |
438 | ||
439 | if (!track->in_list) | |
440 | return; /* We already closed this one, don't close it again. */ | |
441 | ||
442 | /* Remember that this one is closed now */ | |
443 | LIST_REMOVE(tracks, track->bus->tracks, track); | |
444 | track->in_list = false; | |
445 | ||
446 | /* If there's no name in this one anyway, we don't have to dispatch */ | |
447 | if (hashmap_isempty(track->names)) | |
448 | return; | |
449 | ||
450 | /* Let's flush out all names */ | |
451 | while ((i = hashmap_steal_first(track->names))) | |
452 | track_item_free(i); | |
453 | ||
454 | /* Invoke handler */ | |
455 | if (track->handler) | |
456 | bus_track_dispatch(track); | |
457 | } | |
458 | ||
04552566 LP |
459 | _public_ void *sd_bus_track_get_userdata(sd_bus_track *track) { |
460 | assert_return(track, NULL); | |
461 | ||
462 | return track->userdata; | |
463 | } | |
464 | ||
465 | _public_ void *sd_bus_track_set_userdata(sd_bus_track *track, void *userdata) { | |
466 | void *ret; | |
467 | ||
468 | assert_return(track, NULL); | |
469 | ||
470 | ret = track->userdata; | |
471 | track->userdata = userdata; | |
472 | ||
473 | return ret; | |
474 | } | |
ae1a2efa LP |
475 | |
476 | _public_ int sd_bus_track_set_recursive(sd_bus_track *track, int b) { | |
477 | assert_return(track, -EINVAL); | |
478 | ||
479 | if (track->recursive == !!b) | |
480 | return 0; | |
481 | ||
482 | if (!hashmap_isempty(track->names)) | |
483 | return -EBUSY; | |
484 | ||
485 | track->recursive = b; | |
486 | return 0; | |
487 | } | |
488 | ||
489 | _public_ int sd_bus_track_get_recursive(sd_bus_track *track) { | |
490 | assert_return(track, -EINVAL); | |
491 | ||
492 | return track->recursive; | |
493 | } | |
494 | ||
495 | _public_ int sd_bus_track_count_sender(sd_bus_track *track, sd_bus_message *m) { | |
496 | const char *sender; | |
497 | ||
498 | assert_return(m, -EINVAL); | |
499 | ||
500 | if (!track) /* Let's consider a NULL object equivalent to an empty object */ | |
501 | return 0; | |
502 | ||
503 | if (sd_bus_message_get_bus(m) != track->bus) | |
504 | return -EINVAL; | |
505 | ||
506 | sender = sd_bus_message_get_sender(m); | |
507 | if (!sender) | |
508 | return -EINVAL; | |
509 | ||
510 | return sd_bus_track_count_name(track, sender); | |
511 | } | |
512 | ||
513 | _public_ int sd_bus_track_count_name(sd_bus_track *track, const char *name) { | |
514 | struct track_item *i; | |
515 | ||
516 | assert_return(service_name_is_valid(name), -EINVAL); | |
517 | ||
518 | if (!track) /* Let's consider a NULL object equivalent to an empty object */ | |
519 | return 0; | |
520 | ||
521 | i = hashmap_get(track->names, name); | |
522 | if (!i) | |
523 | return 0; | |
524 | ||
525 | return i->n_ref; | |
526 | } |