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1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2013 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 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 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
22 | #include "sd-bus.h" | |
23 | #include "set.h" | |
24 | #include "bus-internal.h" | |
25 | #include "bus-track.h" | |
26 | ||
27 | struct sd_bus_track { | |
28 | unsigned n_ref; | |
29 | sd_bus *bus; | |
30 | sd_bus_track_handler_t handler; | |
31 | void *userdata; | |
32 | Set *names; | |
33 | LIST_FIELDS(sd_bus_track, queue); | |
34 | Iterator iterator; | |
35 | bool in_queue; | |
36 | bool modified; | |
37 | }; | |
38 | ||
39 | #define MATCH_PREFIX \ | |
40 | "type='signal'," \ | |
41 | "sender='org.freedesktop.DBus'," \ | |
42 | "path='/org/freedesktop/DBus'," \ | |
43 | "interface='org.freedesktop.DBus'," \ | |
44 | "member='NameOwnerChanged'," \ | |
45 | "arg0='" | |
46 | ||
47 | #define MATCH_SUFFIX \ | |
48 | "'" | |
49 | ||
50 | #define MATCH_FOR_NAME(name) \ | |
51 | ({ \ | |
52 | char *_x; \ | |
53 | size_t _l = strlen(name); \ | |
f8294e41 | 54 | _x = alloca(strlen(MATCH_PREFIX)+_l+strlen(MATCH_SUFFIX)+1); \ |
8f8f05a9 LP |
55 | strcpy(stpcpy(stpcpy(_x, MATCH_PREFIX), name), MATCH_SUFFIX); \ |
56 | _x; \ | |
57 | }) | |
58 | ||
59 | static void bus_track_add_to_queue(sd_bus_track *track) { | |
60 | assert(track); | |
61 | ||
62 | if (track->in_queue) | |
63 | return; | |
64 | ||
65 | if (!track->handler) | |
66 | return; | |
67 | ||
68 | LIST_PREPEND(queue, track->bus->track_queue, track); | |
69 | track->in_queue = true; | |
70 | } | |
71 | ||
72 | static void bus_track_remove_from_queue(sd_bus_track *track) { | |
73 | assert(track); | |
74 | ||
75 | if (!track->in_queue) | |
76 | return; | |
77 | ||
78 | LIST_REMOVE(queue, track->bus->track_queue, track); | |
79 | track->in_queue = false; | |
80 | } | |
81 | ||
82 | _public_ int sd_bus_track_new( | |
83 | sd_bus *bus, | |
84 | sd_bus_track **track, | |
85 | sd_bus_track_handler_t handler, | |
86 | void *userdata) { | |
87 | ||
88 | sd_bus_track *t; | |
89 | ||
90 | assert_return(bus, -EINVAL); | |
91 | assert_return(track, -EINVAL); | |
92 | ||
93 | t = new0(sd_bus_track, 1); | |
94 | if (!t) | |
95 | return -ENOMEM; | |
96 | ||
97 | t->n_ref = 1; | |
98 | t->handler = handler; | |
99 | t->userdata = userdata; | |
100 | t->bus = sd_bus_ref(bus); | |
101 | ||
102 | bus_track_add_to_queue(t); | |
103 | ||
104 | *track = t; | |
105 | return 0; | |
106 | } | |
107 | ||
108 | _public_ sd_bus_track* sd_bus_track_ref(sd_bus_track *track) { | |
109 | assert_return(track, NULL); | |
110 | ||
111 | assert(track->n_ref > 0); | |
112 | ||
113 | track->n_ref++; | |
114 | ||
115 | return track; | |
116 | } | |
117 | ||
118 | _public_ sd_bus_track* sd_bus_track_unref(sd_bus_track *track) { | |
119 | const char *n; | |
120 | ||
121 | if (!track) | |
122 | return NULL; | |
123 | ||
124 | assert(track->n_ref > 0); | |
125 | ||
126 | if (track->n_ref > 1) { | |
127 | track->n_ref --; | |
128 | return NULL; | |
129 | } | |
130 | ||
131 | while ((n = set_first(track->names))) | |
132 | sd_bus_track_remove_name(track, n); | |
133 | ||
134 | bus_track_remove_from_queue(track); | |
135 | set_free(track->names); | |
136 | sd_bus_unref(track->bus); | |
137 | free(track); | |
138 | ||
139 | return NULL; | |
140 | } | |
141 | ||
142 | static int on_name_owner_changed(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) { | |
143 | sd_bus_track *track = userdata; | |
144 | const char *name, *old, *new; | |
145 | int r; | |
146 | ||
147 | assert(bus); | |
148 | assert(message); | |
149 | assert(track); | |
150 | ||
151 | r = sd_bus_message_read(message, "sss", &name, &old, &new); | |
152 | if (r < 0) | |
153 | return 0; | |
154 | ||
155 | sd_bus_track_remove_name(track, name); | |
156 | return 0; | |
157 | } | |
158 | ||
159 | _public_ int sd_bus_track_add_name(sd_bus_track *track, const char *name) { | |
160 | _cleanup_free_ char *n = NULL; | |
161 | const char *match; | |
162 | int r; | |
163 | ||
164 | assert_return(track, -EINVAL); | |
165 | assert_return(service_name_is_valid(name), -EINVAL); | |
166 | ||
167 | r = set_ensure_allocated(&track->names, string_hash_func, string_compare_func); | |
168 | if (r < 0) | |
169 | return r; | |
170 | ||
171 | n = strdup(name); | |
172 | if (!n) | |
173 | return -ENOMEM; | |
174 | ||
175 | r = set_put(track->names, n); | |
176 | if (r == -EEXIST) | |
177 | return 0; | |
178 | if (r < 0) | |
179 | return r; | |
180 | ||
181 | /* First, subscribe to this name */ | |
182 | match = MATCH_FOR_NAME(name); | |
183 | r = sd_bus_add_match(track->bus, match, on_name_owner_changed, track); | |
184 | if (r < 0) { | |
185 | set_remove(track->names, n); | |
186 | return r; | |
187 | } | |
188 | ||
189 | /* Second, check if it is currently existing, or maybe | |
190 | * doesn't, or maybe disappeared already. */ | |
191 | r = sd_bus_get_owner(track->bus, name, 0, NULL); | |
192 | if (r < 0) { | |
193 | set_remove(track->names, n); | |
194 | sd_bus_remove_match(track->bus, match, on_name_owner_changed, track); | |
195 | return r; | |
196 | } | |
197 | ||
198 | n = NULL; | |
199 | ||
200 | bus_track_remove_from_queue(track); | |
201 | track->modified = true; | |
202 | ||
203 | return 1; | |
204 | } | |
205 | ||
206 | _public_ int sd_bus_track_remove_name(sd_bus_track *track, const char *name) { | |
207 | const char *match; | |
4d463961 | 208 | _cleanup_free_ char *n = NULL;; |
8f8f05a9 LP |
209 | |
210 | assert_return(name, -EINVAL); | |
211 | ||
212 | if (!track) | |
213 | return 0; | |
214 | ||
215 | n = set_remove(track->names, (char*) name); | |
216 | if (!n) | |
217 | return 0; | |
218 | ||
219 | match = MATCH_FOR_NAME(n); | |
220 | sd_bus_remove_match(track->bus, match, on_name_owner_changed, track); | |
221 | ||
222 | if (set_isempty(track->names)) | |
223 | bus_track_add_to_queue(track); | |
224 | ||
225 | track->modified = true; | |
226 | ||
227 | return 1; | |
228 | } | |
229 | ||
230 | _public_ unsigned sd_bus_track_count(sd_bus_track *track) { | |
231 | if (!track) | |
232 | return 0; | |
233 | ||
234 | return set_size(track->names); | |
235 | } | |
236 | ||
237 | _public_ const char* sd_bus_track_contains(sd_bus_track *track, const char *name) { | |
238 | assert_return(track, NULL); | |
239 | assert_return(name, NULL); | |
240 | ||
241 | return set_get(track->names, (void*) name); | |
242 | } | |
243 | ||
244 | _public_ const char* sd_bus_track_first(sd_bus_track *track) { | |
245 | if (!track) | |
246 | return NULL; | |
247 | ||
248 | track->modified = false; | |
249 | track->iterator = NULL; | |
250 | ||
251 | return set_iterate(track->names, &track->iterator); | |
252 | } | |
253 | ||
254 | _public_ const char* sd_bus_track_next(sd_bus_track *track) { | |
255 | if (!track) | |
256 | return NULL; | |
257 | ||
258 | if (track->modified) | |
259 | return NULL; | |
260 | ||
261 | return set_iterate(track->names, &track->iterator); | |
262 | } | |
263 | ||
264 | _public_ int sd_bus_track_add_sender(sd_bus_track *track, sd_bus_message *m) { | |
265 | const char *sender; | |
266 | ||
267 | assert_return(track, -EINVAL); | |
268 | assert_return(m, -EINVAL); | |
269 | ||
270 | sender = sd_bus_message_get_sender(m); | |
271 | if (!sender) | |
272 | return -EINVAL; | |
273 | ||
274 | return sd_bus_track_add_name(track, sender); | |
275 | } | |
276 | ||
277 | _public_ int sd_bus_track_remove_sender(sd_bus_track *track, sd_bus_message *m) { | |
278 | const char *sender; | |
279 | ||
280 | assert_return(track, -EINVAL); | |
281 | assert_return(m, -EINVAL); | |
282 | ||
283 | sender = sd_bus_message_get_sender(m); | |
284 | if (!sender) | |
285 | return -EINVAL; | |
286 | ||
287 | return sd_bus_track_remove_name(track, sender); | |
288 | } | |
289 | ||
290 | _public_ sd_bus* sd_bus_track_get_bus(sd_bus_track *track) { | |
291 | assert_return(track, NULL); | |
292 | ||
293 | return track->bus; | |
294 | } | |
295 | ||
296 | void bus_track_dispatch(sd_bus_track *track) { | |
297 | int r; | |
298 | ||
299 | assert(track); | |
300 | assert(track->in_queue); | |
301 | assert(track->handler); | |
302 | ||
303 | bus_track_remove_from_queue(track); | |
304 | ||
305 | sd_bus_track_ref(track); | |
306 | ||
307 | r = track->handler(track, track->userdata); | |
308 | if (r < 0) | |
309 | log_debug("Failed to process track handler: %s", strerror(-r)); | |
310 | else if (r == 0) | |
311 | bus_track_add_to_queue(track); | |
312 | ||
313 | sd_bus_track_unref(track); | |
314 | } |