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device: don't allow definiing additional aliases via SYSTEMD_NAMES
[people/ms/systemd.git] / device.c
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1/*-*- Mode: C; c-basic-offset: 8 -*-*/
2
a7334b09
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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
25ac040b 22#include <errno.h>
f94ea366 23#include <sys/epoll.h>
25ac040b
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24#include <libudev.h>
25
87f0e418 26#include "unit.h"
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27#include "device.h"
28#include "strv.h"
25ac040b 29#include "log.h"
9e2f7c11 30#include "unit-name.h"
4139c1b2 31#include "dbus-device.h"
5cb5a6ff 32
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33static const UnitActiveState state_translation_table[_DEVICE_STATE_MAX] = {
34 [DEVICE_DEAD] = UNIT_INACTIVE,
35 [DEVICE_AVAILABLE] = UNIT_ACTIVE
36};
37
38static const char* const state_string_table[_DEVICE_STATE_MAX] = {
39 [DEVICE_DEAD] = "dead",
40 [DEVICE_AVAILABLE] = "available"
41};
42
87f0e418
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43static void device_done(Unit *u) {
44 Device *d = DEVICE(u);
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45
46 assert(d);
e537352b 47
25ac040b 48 free(d->sysfs);
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49 d->sysfs = NULL;
50}
51
52static void device_init(Unit *u) {
53 Device *d = DEVICE(u);
54
55 assert(d);
56 assert(u->meta.load_state == UNIT_STUB);
57
58 d->state = 0;
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59}
60
f50e0a01
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61static void device_set_state(Device *d, DeviceState state) {
62 DeviceState old_state;
63 assert(d);
5cb5a6ff 64
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65 old_state = d->state;
66 d->state = state;
5cb5a6ff 67
e537352b 68 if (state != old_state)
9e2f7c11 69 log_debug("%s changed %s → %s", UNIT(d)->meta.id, state_string_table[old_state], state_string_table[state]);
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70
71 unit_notify(UNIT(d), state_translation_table[old_state], state_translation_table[state]);
72}
73
74static int device_coldplug(Unit *u) {
75 Device *d = DEVICE(u);
76
77 assert(d);
78 assert(d->state == DEVICE_DEAD);
79
80 if (d->sysfs)
81 device_set_state(d, DEVICE_AVAILABLE);
82
83 return 0;
84}
85
86static void device_dump(Unit *u, FILE *f, const char *prefix) {
25ac040b 87 Device *d = DEVICE(u);
5cb5a6ff 88
25ac040b 89 assert(d);
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90
91 fprintf(f,
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92 "%sDevice State: %s\n"
93 "%sSysfs Path: %s\n",
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94 prefix, state_string_table[d->state],
95 prefix, strna(d->sysfs));
96}
97
98static UnitActiveState device_active_state(Unit *u) {
99 assert(u);
100
101 return state_translation_table[DEVICE(u)->state];
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102}
103
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104static const char *device_sub_state_to_string(Unit *u) {
105 assert(u);
106
107 return state_string_table[DEVICE(u)->state];
108}
109
2e478a46 110static int device_add_escaped_name(Unit *u, const char *dn, bool make_id) {
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111 char *e;
112 int r;
113
114 assert(u);
115 assert(dn);
116 assert(dn[0] == '/');
117
9e2f7c11 118 if (!(e = unit_name_build_escape(dn+1, NULL, ".device")))
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119 return -ENOMEM;
120
121 r = unit_add_name(u, e);
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122
123 if (r >= 0 && make_id)
124 unit_choose_id(u, e);
125
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126 free(e);
127
128 if (r < 0 && r != -EEXIST)
129 return r;
130
131 return 0;
132}
133
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134static int device_find_escape_name(Manager *m, const char *dn, Unit **_u) {
135 char *e;
136 Unit *u;
137
138 assert(m);
139 assert(dn);
140 assert(dn[0] == '/');
141 assert(_u);
142
9e2f7c11 143 if (!(e = unit_name_build_escape(dn+1, NULL, ".device")))
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144 return -ENOMEM;
145
146 u = manager_get_unit(m, e);
147 free(e);
148
149 if (u) {
150 *_u = u;
151 return 1;
152 }
153
154 return 0;
155}
156
f94ea366 157static int device_process_new_device(Manager *m, struct udev_device *dev, bool update_state) {
0d906814 158 const char *dn, *wants, *sysfs, *expose, *model;
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159 Unit *u = NULL;
160 int r;
aab14b13 161 char *w, *state;
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162 size_t l;
163 bool delete;
164 struct udev_list_entry *item = NULL, *first = NULL;
09e80b16 165 int b;
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166
167 assert(m);
168
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169 if (!(sysfs = udev_device_get_syspath(dev)))
170 return -ENOMEM;
171
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172 if (!(expose = udev_device_get_property_value(dev, "SYSTEMD_EXPOSE")))
173 return 0;
174
175 if ((b = parse_boolean(expose)) < 0) {
176 log_error("Failed to parse SYSTEMD_EXPOSE udev property for device %s: %s", sysfs, expose);
177 return 0;
178 }
179
180 if (!b)
181 return 0;
182
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183 /* Check whether this entry is even relevant for us. */
184 dn = udev_device_get_devnode(dev);
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185 wants = udev_device_get_property_value(dev, "SYSTEMD_WANTS");
186
aab14b13
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187 if ((r = device_find_escape_name(m, sysfs, &u)) < 0)
188 return r;
25ac040b 189
aab14b13
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190 if (r == 0 && dn)
191 if ((r = device_find_escape_name(m, dn, &u)) < 0)
192 return r;
25ac040b 193
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194 if (r == 0) {
195 first = udev_device_get_devlinks_list_entry(dev);
196 udev_list_entry_foreach(item, first) {
197 if ((r = device_find_escape_name(m, udev_list_entry_get_name(item), &u)) < 0)
198 return r;
25ac040b 199
aab14b13
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200 if (r > 0)
201 break;
25ac040b 202 }
aab14b13
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203 }
204
205 /* FIXME: this needs proper merging */
206
207 assert((r > 0) == !!u);
208
209 /* If this is a different unit, then let's not merge things */
210 if (u && DEVICE(u)->sysfs && !streq(DEVICE(u)->sysfs, sysfs))
211 u = NULL;
25ac040b 212
aab14b13
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213 if (!u) {
214 delete = true;
215
216 if (!(u = unit_new(m)))
217 return -ENOMEM;
25ac040b 218
aab14b13 219 if ((r = device_add_escaped_name(u, sysfs, true)) < 0)
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220 goto fail;
221
e537352b
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222 unit_add_to_load_queue(u);
223 } else
224 delete = false;
225
226 if (!(DEVICE(u)->sysfs))
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227 if (!(DEVICE(u)->sysfs = strdup(sysfs))) {
228 r = -ENOMEM;
229 goto fail;
230 }
231
25ac040b 232 if (dn)
2e478a46 233 if ((r = device_add_escaped_name(u, dn, true)) < 0)
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234 goto fail;
235
236 first = udev_device_get_devlinks_list_entry(dev);
237 udev_list_entry_foreach(item, first)
2e478a46 238 if ((r = device_add_escaped_name(u, udev_list_entry_get_name(item), false)) < 0)
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239 goto fail;
240
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241 if ((model = udev_device_get_property_value(dev, "ID_MODEL_FROM_DATABASE")) ||
242 (model = udev_device_get_property_value(dev, "ID_MODEL"))) {
243 if ((r = unit_set_description(u, model)) < 0)
244 goto fail;
245 } else if (dn)
246 if ((r = unit_set_description(u, dn)) < 0)
247 goto fail;
248
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249 if (wants) {
250 FOREACH_WORD(w, l, wants, state) {
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251 char *e;
252
b866264a
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253 if (!(e = strndup(w, l))) {
254 r = -ENOMEM;
25ac040b 255 goto fail;
b866264a 256 }
25ac040b 257
9e2f7c11 258 r = unit_add_dependency_by_name(u, UNIT_WANTS, NULL, e);
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259 free(e);
260
261 if (r < 0)
262 goto fail;
263 }
264 }
265
f94ea366
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266 if (update_state) {
267 manager_dispatch_load_queue(u->meta.manager);
268 device_set_state(DEVICE(u), DEVICE_AVAILABLE);
269 }
270
c1e1601e
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271 unit_add_to_dbus_queue(u);
272
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273 return 0;
274
275fail:
276 if (delete && u)
277 unit_free(u);
278 return r;
279}
280
f94ea366 281static int device_process_path(Manager *m, const char *path, bool update_state) {
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282 int r;
283 struct udev_device *dev;
284
285 assert(m);
286 assert(path);
287
288 if (!(dev = udev_device_new_from_syspath(m->udev, path))) {
289 log_warning("Failed to get udev device object from udev for path %s.", path);
290 return -ENOMEM;
291 }
292
f94ea366 293 r = device_process_new_device(m, dev, update_state);
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294 udev_device_unref(dev);
295 return r;
296}
297
f94ea366
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298static int device_process_removed_device(Manager *m, struct udev_device *dev) {
299 const char *sysfs;
300 char *e;
301 Unit *u;
302 Device *d;
303
304 assert(m);
305 assert(dev);
306
307 if (!(sysfs = udev_device_get_syspath(dev)))
308 return -ENOMEM;
309
310 assert(sysfs[0] == '/');
9e2f7c11 311 if (!(e = unit_name_build_escape(sysfs+1, NULL, ".device")))
f94ea366
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312 return -ENOMEM;
313
314 u = manager_get_unit(m, e);
315 free(e);
316
317 if (!u)
318 return 0;
319
320 d = DEVICE(u);
321 free(d->sysfs);
322 d->sysfs = NULL;
323
324 device_set_state(d, DEVICE_DEAD);
325 return 0;
326}
327
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328static void device_shutdown(Manager *m) {
329 assert(m);
330
f94ea366
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331 if (m->udev_monitor)
332 udev_monitor_unref(m->udev_monitor);
333
25ac040b
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334 if (m->udev)
335 udev_unref(m->udev);
336}
337
338static int device_enumerate(Manager *m) {
f94ea366 339 struct epoll_event ev;
25ac040b
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340 int r;
341 struct udev_enumerate *e = NULL;
342 struct udev_list_entry *item = NULL, *first = NULL;
343
344 assert(m);
345
346 if (!(m->udev = udev_new()))
347 return -ENOMEM;
348
f94ea366
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349 if (!(m->udev_monitor = udev_monitor_new_from_netlink(m->udev, "udev"))) {
350 r = -ENOMEM;
351 goto fail;
352 }
353
354 if (udev_monitor_enable_receiving(m->udev_monitor) < 0) {
355 r = -EIO;
356 goto fail;
357 }
358
359 m->udev_watch.type = WATCH_UDEV;
360 m->udev_watch.fd = udev_monitor_get_fd(m->udev_monitor);
361
362 zero(ev);
363 ev.events = EPOLLIN;
364 ev.data.ptr = &m->udev_watch;
365
366 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->udev_watch.fd, &ev) < 0)
367 return -errno;
368
4f2d528d
LP
369 if (!(e = udev_enumerate_new(m->udev))) {
370 r = -ENOMEM;
371 goto fail;
372 }
25ac040b 373
4f2d528d
LP
374 if (udev_enumerate_scan_devices(e) < 0) {
375 r = -EIO;
376 goto fail;
377 }
25ac040b 378
4f2d528d
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379 first = udev_enumerate_get_list_entry(e);
380 udev_list_entry_foreach(item, first)
381 device_process_path(m, udev_list_entry_get_name(item), false);
25ac040b 382
4f2d528d 383 udev_enumerate_unref(e);
25ac040b
LP
384 return 0;
385
386fail:
387 if (e)
388 udev_enumerate_unref(e);
389
390 device_shutdown(m);
391 return r;
5cb5a6ff
LP
392}
393
f94ea366
LP
394void device_fd_event(Manager *m, int events) {
395 struct udev_device *dev;
396 int r;
397 const char *action;
398
399 assert(m);
400 assert(events == EPOLLIN);
401
f94ea366
LP
402 if (!(dev = udev_monitor_receive_device(m->udev_monitor))) {
403 log_error("Failed to receive device.");
404 return;
405 }
406
407 if (!(action = udev_device_get_action(dev))) {
408 log_error("Failed to get udev action string.");
409 goto fail;
410 }
411
412 if (streq(action, "remove")) {
413 if ((r = device_process_removed_device(m, dev)) < 0) {
414 log_error("Failed to process udev device event: %s", strerror(-r));
415 goto fail;
416 }
417 } else {
418 if ((r = device_process_new_device(m, dev, true)) < 0) {
419 log_error("Failed to process udev device event: %s", strerror(-r));
420 goto fail;
421 }
422 }
423
424fail:
425 udev_device_unref(dev);
426}
427
87f0e418 428const UnitVTable device_vtable = {
5cb5a6ff
LP
429 .suffix = ".device",
430
9e2f7c11
LP
431 .no_requires = true,
432 .no_instances = true,
41447faf 433 .no_snapshots = true,
9e2f7c11 434
e537352b
LP
435 .init = device_init,
436 .load = unit_load_fragment_and_dropin_optional,
034c6ed7 437 .done = device_done,
f50e0a01
LP
438 .coldplug = device_coldplug,
439
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440 .dump = device_dump,
441
f50e0a01 442 .active_state = device_active_state,
10a94420 443 .sub_state_to_string = device_sub_state_to_string,
25ac040b 444
4139c1b2
LP
445 .bus_message_handler = bus_device_message_handler,
446
f50e0a01
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447 .enumerate = device_enumerate,
448 .shutdown = device_shutdown
5cb5a6ff 449};