/*
- * udevd.c
+ * udevd.c - hotplug event serializer
*
- * Userspace devfs
- *
- * Copyright (C) 2004 Ling, Xiaofeng <xiaofeng.ling@intel.com>
* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
*
*
*
*/
+#include <pthread.h>
+#include <stddef.h>
#include <sys/types.h>
-#include <sys/ipc.h>
#include <sys/wait.h>
-#include <sys/msg.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <time.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include "list.h"
#include "udev.h"
+#include "udev_version.h"
#include "udevd.h"
#include "logging.h"
-#define BUFFER_SIZE 1024
-#define EVENT_TIMEOUT_SECONDS 10
-#define DAEMON_TIMEOUT_SECONDS 30
+unsigned char logname[42];
+static pthread_mutex_t msg_lock;
+static pthread_mutex_t msg_active_lock;
+static pthread_cond_t msg_active;
+static pthread_mutex_t exec_lock;
+static pthread_mutex_t exec_active_lock;
+static pthread_cond_t exec_active;
+static pthread_mutex_t running_lock;
+static pthread_attr_t thr_attr;
+static int expected_seqnum = 0;
-static int expect_seqnum = 0;
-static struct hotplug_msg *head = NULL;
+LIST_HEAD(msg_list);
+LIST_HEAD(exec_list);
+LIST_HEAD(running_list);
-static void sig_alarmhandler(int signum)
+static void msg_dump_queue(void)
{
- dbg("caught signal %d", signum);
- switch (signum) {
- case SIGALRM:
- dbg("event timeout reached");
- break;
+ struct hotplug_msg *msg;
- default:
- dbg("unhandled signal");
- }
+ list_for_each_entry(msg, &msg_list, list)
+ dbg("sequence %d in queue", msg->seqnum);
}
-static void dump_queue(void)
+static void msg_dump(struct hotplug_msg *msg)
{
- struct hotplug_msg *p;
- p = head;
+ dbg("sequence %d, '%s', '%s', '%s'",
+ msg->seqnum, msg->action, msg->devpath, msg->subsystem);
+}
- dbg("next expected sequence is %d", expect_seqnum);
- while(p != NULL) {
- dbg("sequence %d in queue", p->seqnum);
- p = p->next;
+static struct hotplug_msg *msg_create(void)
+{
+ struct hotplug_msg *new_msg;
+
+ new_msg = malloc(sizeof(struct hotplug_msg));
+ if (new_msg == NULL) {
+ dbg("error malloc");
+ return NULL;
}
+ return new_msg;
}
-static void dump_msg(struct hotplug_msg *pmsg)
+static void msg_delete(struct hotplug_msg *msg)
{
- dbg("sequence %d, '%s', '%s', '%s'",
- pmsg->seqnum, pmsg->action, pmsg->devpath, pmsg->subsystem);
+ if (msg != NULL)
+ free(msg);
}
-static int dispatch_msg(struct hotplug_msg *pmsg)
+/* orders the message in the queue by sequence number */
+static void msg_queue_insert(struct hotplug_msg *msg)
{
- pid_t pid;
- char *argv[3];
- extern char **environ;
+ struct hotplug_msg *loop_msg;
+
+ /* sort message by sequence number into list*/
+ list_for_each_entry(loop_msg, &msg_list, list)
+ if (loop_msg->seqnum > msg->seqnum)
+ break;
+ list_add_tail(&msg->list, &loop_msg->list);
+ dbg("queued message seq %d", msg->seqnum);
- dump_msg(pmsg);
+ /* store timestamp of queuing */
+ msg->queue_time = time(NULL);
- setenv("ACTION", pmsg->action, 1);
- setenv("DEVPATH", pmsg->devpath, 1);
- argv[0] = DEFAULT_UDEV_EXEC;
- argv[1] = pmsg->subsystem;
- argv[2] = NULL;
+ /* signal queue activity to manager */
+ pthread_mutex_lock(&msg_active_lock);
+ pthread_cond_signal(&msg_active);
+ pthread_mutex_unlock(&msg_active_lock);
+
+ return ;
+}
+
+/* forks event and removes event from run queue when finished */
+static void *run_threads(void * parm)
+{
+ pid_t pid;
+ struct hotplug_msg *msg;
+
+ msg = parm;
+ setenv("ACTION", msg->action, 1);
+ setenv("DEVPATH", msg->devpath, 1);
pid = fork();
switch (pid) {
case 0:
/* child */
- execve(argv[0], argv, environ);
+ execl(UDEV_BIN, "udev", msg->subsystem, NULL);
dbg("exec of child failed");
exit(1);
break;
case -1:
dbg("fork of child failed");
- return -1;
+ goto exit;
default:
- wait(0);
+ /* wait for exit of child */
+ dbg("==> exec seq %d [%d] working at '%s'",
+ msg->seqnum, pid, msg->devpath);
+ wait(NULL);
+ dbg("<== exec seq %d came back", msg->seqnum);
}
- return 0;
+
+exit:
+ /* remove event from run list */
+ pthread_mutex_lock(&running_lock);
+ list_del_init(&msg->list);
+ pthread_mutex_unlock(&running_lock);
+
+ msg_delete(msg);
+
+ /* signal queue activity to exec manager */
+ pthread_mutex_lock(&exec_active_lock);
+ pthread_cond_signal(&exec_active);
+ pthread_mutex_unlock(&exec_active_lock);
+
+ pthread_exit(0);
}
-static void set_timer(int seconds)
+/* returns already running task with devpath */
+static struct hotplug_msg *running_with_devpath(struct hotplug_msg *msg)
{
- signal(SIGALRM, sig_alarmhandler);
- alarm(seconds);
+ struct hotplug_msg *loop_msg;
+ struct hotplug_msg *tmp_msg;
+
+ list_for_each_entry_safe(loop_msg, tmp_msg, &running_list, list)
+ if (strncmp(loop_msg->devpath, msg->devpath, sizeof(loop_msg->devpath)) == 0)
+ return loop_msg;
+ return NULL;
}
-static void check_queue(void)
+/* queue management executes the events and delays events for the same devpath */
+static void *exec_queue_manager(void * parm)
{
- struct hotplug_msg *p;
- p = head;
-
- dump_queue();
- while(head != NULL && head->seqnum == expect_seqnum) {
- dispatch_msg(head);
- expect_seqnum++;
- p = head;
- head = head->next;
- free(p);
+ struct hotplug_msg *loop_msg;
+ struct hotplug_msg *tmp_msg;
+ struct hotplug_msg *msg;
+ pthread_t run_tid;
+
+ while (1) {
+ pthread_mutex_lock(&exec_lock);
+ list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, list) {
+ msg = running_with_devpath(loop_msg);
+ if (msg == NULL) {
+ /* move event to run list */
+ pthread_mutex_lock(&running_lock);
+ list_move_tail(&loop_msg->list, &running_list);
+ pthread_mutex_unlock(&running_lock);
+
+ pthread_create(&run_tid, &thr_attr, run_threads, (void *) loop_msg);
+
+ dbg("moved seq %d to running list", loop_msg->seqnum);
+ } else {
+ dbg("delay seq %d, cause seq %d already working on '%s'",
+ loop_msg->seqnum, msg->seqnum, msg->devpath);
+ }
+ }
+ pthread_mutex_unlock(&exec_lock);
+
+ /* wait for activation, new events or childs coming back */
+ pthread_mutex_lock(&exec_active_lock);
+ pthread_cond_wait(&exec_active, &exec_active_lock);
+ pthread_mutex_unlock(&exec_active_lock);
}
- if (head != NULL)
- set_timer(EVENT_TIMEOUT_SECONDS);
- else
- set_timer(DAEMON_TIMEOUT_SECONDS);
}
-static void add_queue(struct hotplug_msg *pmsg)
+/* move message from incoming to exec queue */
+static void msg_move_exec(struct list_head *head)
{
- struct hotplug_msg *pnewmsg;
- struct hotplug_msg *p;
- struct hotplug_msg *p1;
-
- p = head;
- p1 = NULL;
- pnewmsg = malloc(sizeof(struct hotplug_msg));
- *pnewmsg = *pmsg;
- pnewmsg->next = NULL;
- while(p != NULL && pmsg->seqnum > p->seqnum) {
- p1 = p;
- p = p->next;
- }
- pnewmsg->next = p;
- if (p1 == NULL) {
- head = pnewmsg;
- } else {
- p1->next = pnewmsg;
- }
- dump_queue();
+ list_move_tail(head, &exec_list);
+ /* signal queue activity to manager */
+ pthread_mutex_lock(&exec_active_lock);
+ pthread_cond_signal(&exec_active);
+ pthread_mutex_unlock(&exec_active_lock);
}
-static int process_queue(void)
+/* queue management thread handles the timeouts and dispatches the events */
+static void *msg_queue_manager(void * parm)
{
- int msgid;
- key_t key;
- struct hotplug_msg *pmsg;
- char buf[BUFFER_SIZE];
- int ret;
-
- key = ftok(DEFAULT_UDEVD_EXEC, IPC_KEY_ID);
- pmsg = (struct hotplug_msg *) buf;
- msgid = msgget(key, IPC_CREAT);
- if (msgid == -1) {
- dbg("open message queue error");
- return -1;
- }
+ struct hotplug_msg *loop_msg;
+ struct hotplug_msg *tmp_msg;
+ time_t msg_age = 0;
+ struct timespec tv;
+
while (1) {
- ret = msgrcv(msgid, (struct msgbuf *) buf, BUFFER_SIZE-4, HOTPLUGMSGTYPE, 0);
- if (ret != -1) {
- dbg("current sequence %d, expected sequence %d", pmsg->seqnum, expect_seqnum);
-
- /* init expected sequence with value from first call */
- if (expect_seqnum == 0) {
- expect_seqnum = pmsg->seqnum;
- dbg("init next expected sequence number to %d", expect_seqnum);
+ dbg("msg queue manager, next expected is %d", expected_seqnum);
+ pthread_mutex_lock(&msg_lock);
+ pthread_mutex_lock(&exec_lock);
+recheck:
+ list_for_each_entry_safe(loop_msg, tmp_msg, &msg_list, list) {
+ /* move event with expected sequence to the exec list */
+ if (loop_msg->seqnum == expected_seqnum) {
+ msg_move_exec(&loop_msg->list);
+ expected_seqnum++;
+ dbg("moved seq %d to exec, next expected is %d",
+ loop_msg->seqnum, expected_seqnum);
+ continue;
}
- if (pmsg->seqnum > expect_seqnum) {
- add_queue(pmsg);
- set_timer(EVENT_TIMEOUT_SECONDS);
+ /* move event with expired timeout to the exec list */
+ msg_age = time(NULL) - loop_msg->queue_time;
+ if (msg_age > EVENT_TIMEOUT_SEC-1) {
+ msg_move_exec(&loop_msg->list);
+ expected_seqnum = loop_msg->seqnum+1;
+ dbg("moved seq %d to exec, reset next expected to %d",
+ loop_msg->seqnum, expected_seqnum);
+ goto recheck;
} else {
- if (pmsg->seqnum == expect_seqnum) {
- dispatch_msg(pmsg);
- expect_seqnum++;
- check_queue();
- } else {
- dbg("timeout event for unexpected sequence number %d", pmsg->seqnum);
- }
+ break;
}
+ }
+
+ msg_dump_queue();
+ pthread_mutex_unlock(&exec_lock);
+ pthread_mutex_unlock(&msg_lock);
+
+ /* wait until queue gets active or next message timeout expires */
+ pthread_mutex_lock(&msg_active_lock);
+
+ if (list_empty(&msg_list) == 0) {
+ tv.tv_sec = time(NULL) + EVENT_TIMEOUT_SEC - msg_age;
+ tv.tv_nsec = 0;
+ dbg("next event expires in %li seconds",
+ EVENT_TIMEOUT_SEC - msg_age);
+ pthread_cond_timedwait(&msg_active, &msg_active_lock, &tv);
} else {
- if (errno == EINTR) {
- if (head != NULL) {
- /* event timeout, skip all missing, proceed with next queued event */
- info("timeout reached, skip events %d - %d", expect_seqnum, head->seqnum-1);
- expect_seqnum = head->seqnum;
- } else {
- info("we have nothing to do, so daemon exits...");
- exit(0);
- }
- check_queue();
- } else {
- dbg("ipc message receive error '%s'", strerror(errno));
- }
+ pthread_cond_wait(&msg_active, &msg_active_lock);
}
+ pthread_mutex_unlock(&msg_active_lock);
}
- return 0;
+}
+
+/* every connect creates a thread which gets the msg, queues it and exits */
+static void *client_threads(void * parm)
+{
+ int sock;
+ struct hotplug_msg *msg;
+ int retval;
+
+ sock = (int) parm;
+
+ msg = msg_create();
+ if (msg == NULL) {
+ dbg("unable to store message");
+ goto exit;
+ }
+
+ retval = recv(sock, msg, sizeof(struct hotplug_msg), 0);
+ if (retval < 0) {
+ dbg("unable to receive message");
+ goto exit;
+ }
+
+ if (strncmp(msg->magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) {
+ dbg("message magic '%s' doesn't match, ignore it", msg->magic);
+ msg_delete(msg);
+ goto exit;
+ }
+
+ pthread_mutex_lock(&msg_lock);
+ msg_queue_insert(msg);
+ pthread_mutex_unlock(&msg_lock);
+
+exit:
+ close(sock);
+ pthread_exit(0);
}
static void sig_handler(int signum)
{
- dbg("caught signal %d", signum);
switch (signum) {
case SIGINT:
case SIGTERM:
- case SIGKILL:
+ unlink(UDEVD_LOCK);
+ unlink(UDEVD_SOCK);
exit(20 + signum);
break;
-
default:
dbg("unhandled signal");
}
}
+static int one_and_only(void)
+{
+ char string[50];
+ int lock_file;
+
+ lock_file = open(UDEVD_LOCK, O_RDWR | O_CREAT, 0x640);
+ if (lock_file < 0)
+ return -1;
+
+ /* see if we can lock */
+ if (lockf(lock_file, F_TLOCK, 0) < 0) {
+ dbg("file is already locked, exit");
+ close(lock_file);
+ return -1;
+ }
+
+ snprintf(string, sizeof(string), "%d\n", getpid());
+ write(lock_file, string, strlen(string));
+
+ return 0;
+}
+
int main(int argc, char *argv[])
{
- /* set up signal handler */
+ int ssock;
+ int csock;
+ struct sockaddr_un saddr;
+ struct sockaddr_un caddr;
+ socklen_t clen;
+ pthread_t cli_tid;
+ pthread_t mgr_msg_tid;
+ pthread_t mgr_exec_tid;
+ int retval;
+
+ init_logging("udevd");
+
+ /* only let one version of the daemon run at any one time */
+ if (one_and_only() != 0)
+ exit(0);
+
signal(SIGINT, sig_handler);
signal(SIGTERM, sig_handler);
- signal(SIGKILL, sig_handler);
- /* we exit if we have nothing to do, next event will start us again */
- set_timer(DAEMON_TIMEOUT_SECONDS);
+ memset(&saddr, 0x00, sizeof(saddr));
+ saddr.sun_family = AF_LOCAL;
+ strcpy(saddr.sun_path, UDEVD_SOCK);
+
+ unlink(UDEVD_SOCK);
+ ssock = socket(AF_LOCAL, SOCK_STREAM, 0);
+ if (ssock == -1) {
+ dbg("error getting socket");
+ exit(1);
+ }
+
+ retval = bind(ssock, &saddr, sizeof(saddr));
+ if (retval < 0) {
+ dbg("bind failed\n");
+ goto exit;
+ }
+
+ retval = listen(ssock, SOMAXCONN);
+ if (retval < 0) {
+ dbg("listen failed\n");
+ goto exit;
+ }
+
+ pthread_mutex_init(&msg_lock, NULL);
+ pthread_mutex_init(&msg_active_lock, NULL);
+ pthread_mutex_init(&exec_lock, NULL);
+ pthread_mutex_init(&exec_active_lock, NULL);
+ pthread_mutex_init(&running_lock, NULL);
+
+ /* set default attributes for created threads */
+ pthread_attr_init(&thr_attr);
+ pthread_attr_setdetachstate(&thr_attr, PTHREAD_CREATE_DETACHED);
+ pthread_attr_setstacksize(&thr_attr, 16 * 1024);
+ /* init queue management */
+ pthread_create(&mgr_msg_tid, &thr_attr, msg_queue_manager, NULL);
+ pthread_create(&mgr_exec_tid, &thr_attr, exec_queue_manager, NULL);
+
+ clen = sizeof(caddr);
/* main loop */
- process_queue();
- return 0;
+ while (1) {
+ csock = accept(ssock, &caddr, &clen);
+ if (csock < 0) {
+ dbg("client accept failed\n");
+ continue;
+ }
+ pthread_create(&cli_tid, &thr_attr, client_threads, (void *) csock);
+ }
+exit:
+ close(ssock);
+ unlink(UDEVD_SOCK);
+ exit(1);
}
~ianmdlvl / elogind.git / blobdiff