2 * udevd.c - hotplug event serializer
4 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation version 2 of the License.
11 * This program 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 * General Public License for more details.
16 * You should have received a copy of the GNU General Public License along
17 * with this program; if not, write to the Free Software Foundation, Inc.,
18 * 675 Mass Ave, Cambridge, MA 02139, USA.
23 #include <sys/types.h>
33 #include <sys/types.h>
34 #include <sys/socket.h>
40 #include "udev_version.h"
45 static pthread_mutex_t msg_lock
;
46 static pthread_mutex_t msg_active_lock
;
47 static pthread_cond_t msg_active
;
48 static pthread_mutex_t exec_lock
;
49 static pthread_mutex_t exec_active_lock
;
50 static pthread_cond_t exec_active
;
51 static pthread_mutex_t running_lock
;
52 static pthread_attr_t thr_attr
;
53 static int expected_seqnum
= 0;
57 LIST_HEAD(running_list
);
60 static void msg_dump_queue(void)
62 struct hotplug_msg
*msg
;
64 list_for_each_entry(msg
, &msg_list
, list
)
65 dbg("sequence %d in queue", msg
->seqnum
);
68 static void msg_dump(struct hotplug_msg
*msg
)
70 dbg("sequence %d, '%s', '%s', '%s'",
71 msg
->seqnum
, msg
->action
, msg
->devpath
, msg
->subsystem
);
74 /* allocates a new message */
75 static struct hotplug_msg
*msg_create(void)
77 struct hotplug_msg
*new_msg
;
79 new_msg
= malloc(sizeof(struct hotplug_msg
));
80 if (new_msg
== NULL
) {
84 memset(new_msg
, 0x00, sizeof(struct hotplug_msg
));
88 /* orders the message in the queue by sequence number */
89 static void msg_queue_insert(struct hotplug_msg
*msg
)
91 struct hotplug_msg
*loop_msg
;
93 /* sort message by sequence number into list*/
94 list_for_each_entry(loop_msg
, &msg_list
, list
)
95 if (loop_msg
->seqnum
> msg
->seqnum
)
97 list_add_tail(&msg
->list
, &loop_msg
->list
);
98 dbg("queued message seq %d", msg
->seqnum
);
100 /* store timestamp of queuing */
101 msg
->queue_time
= time(NULL
);
103 /* signal queue activity to manager */
104 pthread_mutex_lock(&msg_active_lock
);
105 pthread_cond_signal(&msg_active
);
106 pthread_mutex_unlock(&msg_active_lock
);
111 /* forks event and removes event from run queue when finished */
112 static void *run_threads(void * parm
)
115 struct hotplug_msg
*msg
;
118 setenv("ACTION", msg
->action
, 1);
119 setenv("DEVPATH", msg
->devpath
, 1);
125 execl(UDEV_BIN
, "udev", msg
->subsystem
, NULL
);
126 dbg("exec of child failed");
130 dbg("fork of child failed");
133 /* wait for exit of child */
134 dbg("==> exec seq %d [%d] working at '%s'",
135 msg
->seqnum
, pid
, msg
->devpath
);
137 dbg("<== exec seq %d came back", msg
->seqnum
);
141 /* remove event from run list */
142 pthread_mutex_lock(&running_lock
);
143 list_del_init(&msg
->list
);
144 pthread_mutex_unlock(&running_lock
);
148 /* signal queue activity to exec manager */
149 pthread_mutex_lock(&exec_active_lock
);
150 pthread_cond_signal(&exec_active
);
151 pthread_mutex_unlock(&exec_active_lock
);
156 /* returns already running task with devpath */
157 static struct hotplug_msg
*running_with_devpath(struct hotplug_msg
*msg
)
159 struct hotplug_msg
*loop_msg
;
160 struct hotplug_msg
*tmp_msg
;
162 list_for_each_entry_safe(loop_msg
, tmp_msg
, &running_list
, list
)
163 if (strncmp(loop_msg
->devpath
, msg
->devpath
, sizeof(loop_msg
->devpath
)) == 0)
168 /* queue management executes the events and delays events for the same devpath */
169 static void *exec_queue_manager(void * parm
)
171 struct hotplug_msg
*loop_msg
;
172 struct hotplug_msg
*tmp_msg
;
173 struct hotplug_msg
*msg
;
177 pthread_mutex_lock(&exec_lock
);
178 list_for_each_entry_safe(loop_msg
, tmp_msg
, &exec_list
, list
) {
179 msg
= running_with_devpath(loop_msg
);
181 /* move event to run list */
182 pthread_mutex_lock(&running_lock
);
183 list_move_tail(&loop_msg
->list
, &running_list
);
184 pthread_mutex_unlock(&running_lock
);
186 pthread_create(&run_tid
, &thr_attr
, run_threads
, (void *) loop_msg
);
188 dbg("moved seq %d to running list", loop_msg
->seqnum
);
190 dbg("delay seq %d, cause seq %d already working on '%s'",
191 loop_msg
->seqnum
, msg
->seqnum
, msg
->devpath
);
194 pthread_mutex_unlock(&exec_lock
);
196 /* wait for activation, new events or childs coming back */
197 pthread_mutex_lock(&exec_active_lock
);
198 pthread_cond_wait(&exec_active
, &exec_active_lock
);
199 pthread_mutex_unlock(&exec_active_lock
);
203 /* move message from incoming to exec queue */
204 static void msg_move_exec(struct list_head
*head
)
206 list_move_tail(head
, &exec_list
);
207 /* signal queue activity to manager */
208 pthread_mutex_lock(&exec_active_lock
);
209 pthread_cond_signal(&exec_active
);
210 pthread_mutex_unlock(&exec_active_lock
);
213 /* queue management thread handles the timeouts and dispatches the events */
214 static void *msg_queue_manager(void * parm
)
216 struct hotplug_msg
*loop_msg
;
217 struct hotplug_msg
*tmp_msg
;
222 dbg("msg queue manager, next expected is %d", expected_seqnum
);
223 pthread_mutex_lock(&msg_lock
);
224 pthread_mutex_lock(&exec_lock
);
226 list_for_each_entry_safe(loop_msg
, tmp_msg
, &msg_list
, list
) {
227 /* move event with expected sequence to the exec list */
228 if (loop_msg
->seqnum
== expected_seqnum
) {
229 msg_move_exec(&loop_msg
->list
);
231 dbg("moved seq %d to exec, next expected is %d",
232 loop_msg
->seqnum
, expected_seqnum
);
236 /* move event with expired timeout to the exec list */
237 msg_age
= time(NULL
) - loop_msg
->queue_time
;
238 if (msg_age
> EVENT_TIMEOUT_SEC
-1) {
239 msg_move_exec(&loop_msg
->list
);
240 expected_seqnum
= loop_msg
->seqnum
+1;
241 dbg("moved seq %d to exec, reset next expected to %d",
242 loop_msg
->seqnum
, expected_seqnum
);
250 pthread_mutex_unlock(&exec_lock
);
251 pthread_mutex_unlock(&msg_lock
);
253 /* wait until queue gets active or next message timeout expires */
254 pthread_mutex_lock(&msg_active_lock
);
256 if (list_empty(&msg_list
) == 0) {
257 tv
.tv_sec
= time(NULL
) + EVENT_TIMEOUT_SEC
- msg_age
;
259 dbg("next event expires in %li seconds",
260 EVENT_TIMEOUT_SEC
- msg_age
);
261 pthread_cond_timedwait(&msg_active
, &msg_active_lock
, &tv
);
263 pthread_cond_wait(&msg_active
, &msg_active_lock
);
265 pthread_mutex_unlock(&msg_active_lock
);
269 /* every connect creates a thread which gets the msg, queues it and exits */
270 static void *client_threads(void * parm
)
273 struct hotplug_msg
*msg
;
280 dbg("unable to store message");
284 retval
= recv(sock
, msg
, sizeof(struct hotplug_msg
), 0);
286 dbg("unable to receive message");
290 if (strncmp(msg
->magic
, UDEV_MAGIC
, sizeof(UDEV_MAGIC
)) != 0 ) {
291 dbg("message magic '%s' doesn't match, ignore it", msg
->magic
);
295 pthread_mutex_lock(&msg_lock
);
296 msg_queue_insert(msg
);
297 pthread_mutex_unlock(&msg_lock
);
304 static void sig_handler(int signum
)
310 unlink(UDEVD_SOCKET
);
314 dbg("unhandled signal");
318 static int one_and_only(void)
323 /* see if we can open */
324 lock_file
= open(UDEVD_LOCK
, O_RDWR
| O_CREAT
, 0x640);
328 /* see if we can lock */
329 if (lockf(lock_file
, F_TLOCK
, 0) < 0) {
330 dbg("file is already locked, exit");
335 snprintf(string
, sizeof(string
), "%d\n", getpid());
336 write(lock_file
, string
, strlen(string
));
341 int main(int argc
, char *argv
[])
345 struct sockaddr_un saddr
;
346 struct sockaddr_un caddr
;
349 pthread_t mgr_msg_tid
;
350 pthread_t mgr_exec_tid
;
353 /* only let one version of the daemon run at any one time */
354 if (one_and_only() != 0)
357 signal(SIGINT
, sig_handler
);
358 signal(SIGTERM
, sig_handler
);
360 memset(&saddr
, 0x00, sizeof(saddr
));
361 saddr
.sun_family
= AF_LOCAL
;
362 strcpy(saddr
.sun_path
, UDEVD_SOCKET
);
364 unlink(UDEVD_SOCKET
);
365 ssock
= socket(AF_LOCAL
, SOCK_STREAM
, 0);
367 dbg("error getting socket");
371 retval
= bind(ssock
, &saddr
, sizeof(saddr
));
373 dbg("bind failed\n");
377 retval
= listen(ssock
, SOMAXCONN
);
379 dbg("listen failed\n");
383 pthread_mutex_init(&msg_lock
, NULL
);
384 pthread_mutex_init(&msg_active_lock
, NULL
);
385 pthread_mutex_init(&exec_lock
, NULL
);
386 pthread_mutex_init(&exec_active_lock
, NULL
);
387 pthread_mutex_init(&running_lock
, NULL
);
389 /* set default attributes for created threads */
390 pthread_attr_init(&thr_attr
);
391 pthread_attr_setdetachstate(&thr_attr
, PTHREAD_CREATE_DETACHED
);
393 /* init queue management */
394 pthread_create(&mgr_msg_tid
, &thr_attr
, msg_queue_manager
, NULL
);
395 pthread_create(&mgr_exec_tid
, &thr_attr
, exec_queue_manager
, NULL
);
397 clen
= sizeof(caddr
);
400 csock
= accept(ssock
, &caddr
, &clen
);
404 dbg("client accept failed\n");
406 pthread_create(&cli_tid
, &thr_attr
, client_threads
, (void *) csock
);
410 unlink(UDEVD_SOCKET
);