6 * Copyright (C) 2004 Ling, Xiaofeng <xiaofeng.ling@intel.com>
7 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation version 2 of the License.
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 675 Mass Ave, Cambridge, MA 02139, USA.
26 #include <sys/types.h>
44 #define BUFFER_SIZE 1024
46 static int expect_seqnum = 0;
47 static int lock_file = -1;
48 static char *lock_filename = ".udevd_lock";
52 static void sig_handler(int signum)
54 dbg("caught signal %d", signum);
57 dbg("event timeout reached");
64 unlink(lock_filename);
69 dbg("unhandled signal");
73 static void dump_queue(void)
75 struct hotplug_msg *msg;
77 list_for_each_entry(msg, &msg_list, list)
78 dbg("sequence %d in queue", msg->seqnum);
81 static void dump_msg(struct hotplug_msg *msg)
83 dbg("sequence %d, '%s', '%s', '%s'",
84 msg->seqnum, msg->action, msg->devpath, msg->subsystem);
87 static int dispatch_msg(struct hotplug_msg *msg)
93 setenv("ACTION", msg->action, 1);
94 setenv("DEVPATH", msg->devpath, 1);
100 execl(UDEV_EXEC, "udev", msg->subsystem, NULL);
101 dbg("exec of child failed");
105 dbg("fork of child failed");
113 static void set_timeout(int seconds)
116 dbg("set timeout in %d seconds", seconds);
119 static void check_queue(void)
121 struct hotplug_msg *msg;
122 struct hotplug_msg *tmp_msg;
126 /* dispatch events until one is missing */
127 list_for_each_entry_safe(msg, tmp_msg, &msg_list, list) {
128 if (msg->seqnum != expect_seqnum)
132 list_del_init(&msg->list);
136 /* recalculate timeout */
137 if (list_empty(&msg_list) == 0) {
138 msg_age = time(NULL) - msg->queue_time;
139 if (msg_age > EVENT_TIMEOUT_SECONDS-1) {
140 info("event %d, age %li seconds, skip event %d-%d",
141 msg->seqnum, msg_age, expect_seqnum, msg->seqnum-1);
142 expect_seqnum = msg->seqnum;
145 set_timeout(EVENT_TIMEOUT_SECONDS - msg_age);
150 set_timeout(UDEVD_TIMEOUT_SECONDS);
153 static int queue_msg(struct hotplug_msg *msg)
155 struct hotplug_msg *new_msg;
156 struct hotplug_msg *tmp_msg;
158 new_msg = malloc(sizeof(*new_msg));
159 if (new_msg == NULL) {
163 memcpy(new_msg, msg, sizeof(*new_msg));
165 /* store timestamp of queuing */
166 new_msg->queue_time = time(NULL);
168 /* sort message by sequence number into list*/
169 list_for_each_entry(tmp_msg, &msg_list, list)
170 if (tmp_msg->seqnum > new_msg->seqnum)
172 list_add_tail(&new_msg->list, &tmp_msg->list);
177 static void work(void)
179 struct hotplug_msg *msg;
182 char buf[BUFFER_SIZE];
185 key = ftok(UDEVD_EXEC, IPC_KEY_ID);
186 msg = (struct hotplug_msg *) buf;
187 msgid = msgget(key, IPC_CREAT);
189 dbg("open message queue error");
193 ret = msgrcv(msgid, (struct msgbuf *) buf, BUFFER_SIZE-4, HOTPLUGMSGTYPE, 0);
195 /* init the expected sequence with value from first call */
196 if (expect_seqnum == 0) {
197 expect_seqnum = msg->seqnum;
198 dbg("init next expected sequence number to %d", expect_seqnum);
200 dbg("current sequence %d, expected sequence %d", msg->seqnum, expect_seqnum);
201 if (msg->seqnum == expect_seqnum) {
202 /* execute expected event */
209 if (msg->seqnum > expect_seqnum) {
210 /* something missing, queue event*/
216 dbg("too late for event with sequence %d, even skipped ", msg->seqnum);
218 if (errno == EINTR) {
220 if (list_empty(&msg_list)) {
221 info("we have nothing to do, so daemon exits...");
222 if (lock_file >= 0) {
224 unlink(lock_filename);
232 dbg("ipc message receive error '%s'", strerror(errno));
237 static int one_and_only(void)
241 lock_file = open(lock_filename, O_RDWR | O_CREAT, 0x640);
243 /* see if we can open */
247 /* see if we can lock */
248 if (lockf(lock_file, F_TLOCK, 0) < 0) {
250 unlink(lock_filename);
254 snprintf(string, sizeof(string), "%d\n", getpid());
255 write(lock_file, string, strlen(string));
260 int main(int argc, char *argv[])
262 /* only let one version of the daemon run at any one time */
263 if (one_and_only() != 0)
266 /* set up signal handler */
267 signal(SIGINT, sig_handler);
268 signal(SIGTERM, sig_handler);
269 signal(SIGKILL, sig_handler);
270 signal(SIGALRM, sig_handler);
272 /* we exit if we have nothing to do, next event will start us again */
273 set_timeout(UDEVD_TIMEOUT_SECONDS);