/*
- * 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 <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 <string.h>
#include <time.h>
#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <pthread.h>
#include "list.h"
#include "udev.h"
#include "logging.h"
-#define BUFFER_SIZE 1024
-
-static int running_remove_queue(pid_t pid);
-static int msg_exec(struct hotplug_msg *msg);
-
-static int expect_seqnum = 0;
-static int lock_file = -1;
-static char *lock_filename = ".udevd_lock";
+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;
LIST_HEAD(msg_list);
+LIST_HEAD(exec_list);
LIST_HEAD(running_list);
-LIST_HEAD(delayed_list);
-static void sig_handler(int signum)
-{
- pid_t pid;
-
- dbg("caught signal %d", signum);
- switch (signum) {
- case SIGALRM:
- dbg("event timeout reached");
- break;
- case SIGCHLD:
- /* catch signals from exiting childs */
- while ( (pid = waitpid(-1, NULL, WNOHANG)) > 0) {
- dbg("exec finished, pid %d", pid);
- running_remove_queue(pid);
- }
- break;
- case SIGINT:
- case SIGTERM:
- if (lock_file >= 0) {
- close(lock_file);
- unlink(lock_filename);
- }
- exit(20 + signum);
- break;
- default:
- dbg("unhandled signal");
- }
-}
-static void set_timeout(int seconds)
+static void msg_dump_queue(void)
{
- alarm(seconds);
- dbg("set timeout in %d seconds", seconds);
-}
+ struct hotplug_msg *msg;
-static int running_moveto_queue(struct hotplug_msg *msg)
-{
- dbg("move sequence %d [%d] to running queue '%s'",
- msg->seqnum, msg->pid, msg->devpath);
- list_move_tail(&msg->list, &running_list);
- return 0;
+ list_for_each_entry(msg, &msg_list, list)
+ dbg("sequence %d in queue", msg->seqnum);
}
-static int running_remove_queue(pid_t pid)
+static void msg_dump(struct hotplug_msg *msg)
{
- struct hotplug_msg *child;
- struct hotplug_msg *tmp_child;
-
- list_for_each_entry_safe(child, tmp_child, &running_list, list)
- if (child->pid == pid) {
- list_del_init(&child->list);
- free(child);
- return 0;
- }
- return -EINVAL;
+ dbg("sequence %d, '%s', '%s', '%s'",
+ msg->seqnum, msg->action, msg->devpath, msg->subsystem);
}
-static pid_t running_getpid_by_devpath(struct hotplug_msg *msg)
+/* allocates a new message */
+static struct hotplug_msg *msg_create(void)
{
- struct hotplug_msg *child;
- struct hotplug_msg *tmp_child;
+ struct hotplug_msg *new_msg;
- list_for_each_entry_safe(child, tmp_child, &running_list, list)
- if (strncmp(child->devpath, msg->devpath, sizeof(child->devpath)) == 0)
- return child->pid;
- return 0;
+ new_msg = malloc(sizeof(struct hotplug_msg));
+ if (new_msg == NULL) {
+ dbg("error malloc");
+ return NULL;
+ }
+ memset(new_msg, 0x00, sizeof(struct hotplug_msg));
+ return new_msg;
}
-static void delayed_dump_queue(void)
+/* orders the message in the queue by sequence number */
+static void msg_queue_insert(struct hotplug_msg *msg)
{
- struct hotplug_msg *child;
+ struct hotplug_msg *loop_msg;
- list_for_each_entry(child, &delayed_list, list)
- dbg("event for '%s' in queue", child->devpath);
-}
+ /* 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);
-static int delayed_moveto_queue(struct hotplug_msg *msg)
-{
- dbg("move event to delayed queue '%s'", msg->devpath);
- list_move_tail(&msg->list, &delayed_list);
- return 0;
-}
+ /* store timestamp of queuing */
+ msg->queue_time = time(NULL);
-static void delayed_check_queue(void)
-{
- struct hotplug_msg *delayed_child;
- struct hotplug_msg *running_child;
- struct hotplug_msg *tmp_child;
-
- /* see if we have delayed exec's that can run now */
- list_for_each_entry_safe(delayed_child, tmp_child, &delayed_list, list)
- list_for_each_entry_safe(running_child, tmp_child, &running_list, list)
- if (strncmp(delayed_child->devpath, running_child->devpath,
- sizeof(running_child->devpath)) == 0) {
- dbg("delayed exec for '%s' can run now", delayed_child->devpath);
- msg_exec(delayed_child);
- }
-}
+ /* signal queue activity to manager */
+ pthread_mutex_lock(&msg_active_lock);
+ pthread_cond_signal(&msg_active);
+ pthread_mutex_unlock(&msg_active_lock);
-static void msg_dump(struct hotplug_msg *msg)
-{
- dbg("sequence %d, '%s', '%s', '%s'",
- msg->seqnum, msg->action, msg->devpath, msg->subsystem);
+ return ;
}
-static int msg_exec(struct hotplug_msg *msg)
+/* forks event and removes event from run queue when finished */
+static void *run_threads(void * parm)
{
pid_t pid;
+ struct hotplug_msg *msg;
- msg_dump(msg);
-
+ msg = parm;
setenv("ACTION", msg->action, 1);
setenv("DEVPATH", msg->devpath, 1);
- /* delay exec, if we already have a udev working on the same devpath */
- pid = running_getpid_by_devpath(msg);
- if (pid != 0) {
- dbg("delay exec of sequence %d, [%d] already working on '%s'",
- msg->seqnum, pid, msg->devpath);
- delayed_moveto_queue(msg);
- }
-
pid = fork();
switch (pid) {
case 0:
break;
case -1:
dbg("fork of child failed");
- return -1;
+ goto exit;
default:
- /* exec in background, get the SIGCHLD with the sig handler */
- msg->pid = pid;
- running_moveto_queue(msg);
- break;
+ /* 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);
+
+ free(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 msg_dump_queue(void)
+/* returns already running task with devpath */
+static struct hotplug_msg *running_with_devpath(struct hotplug_msg *msg)
{
- struct hotplug_msg *msg;
+ struct hotplug_msg *loop_msg;
+ struct hotplug_msg *tmp_msg;
- list_for_each_entry(msg, &msg_list, list)
- dbg("sequence %d in queue", msg->seqnum);
+ 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 msg_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 *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);
+ }
+}
+
+/* move message from incoming to exec queue */
+static void msg_move_exec(struct list_head *head)
+{
+ 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);
+}
+
+/* queue management thread handles the timeouts and dispatches the events */
+static void *msg_queue_manager(void * parm)
+{
+ struct hotplug_msg *loop_msg;
struct hotplug_msg *tmp_msg;
- time_t msg_age;
+ time_t msg_age = 0;
+ struct timespec tv;
+ while (1) {
+ dbg("msg queue manager, next expected is %d", expected_seqnum);
+ pthread_mutex_lock(&msg_lock);
+ pthread_mutex_lock(&exec_lock);
recheck:
- /* dispatch events until one is missing */
- list_for_each_entry_safe(msg, tmp_msg, &msg_list, list) {
- if (msg->seqnum != expect_seqnum)
- break;
- msg_exec(msg);
- expect_seqnum++;
- }
+ 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;
+ }
- /* recalculate next timeout */
- if (list_empty(&msg_list) == 0) {
- msg_age = time(NULL) - msg->queue_time;
- if (msg_age > EVENT_TIMEOUT_SEC-1) {
- info("event %d, age %li seconds, skip event %d-%d",
- msg->seqnum, msg_age, expect_seqnum, msg->seqnum-1);
- expect_seqnum = msg->seqnum;
- goto recheck;
+ /* 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 {
+ break;
+ }
}
- /* the first sequence gets its own timeout */
- if (expect_seqnum == 0) {
- msg_age = EVENT_TIMEOUT_SEC - FIRST_EVENT_TIMEOUT_SEC;
- expect_seqnum = 1;
- }
+ msg_dump_queue();
+ pthread_mutex_unlock(&exec_lock);
+ pthread_mutex_unlock(&msg_lock);
- set_timeout(EVENT_TIMEOUT_SEC - msg_age);
- return;
+ /* 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 {
+ pthread_cond_wait(&msg_active, &msg_active_lock);
+ }
+ pthread_mutex_unlock(&msg_active_lock);
}
}
-static int msg_add_queue(struct hotplug_msg *msg)
+/* every connect creates a thread which gets the msg, queues it and exits */
+static void *client_threads(void * parm)
{
- struct hotplug_msg *new_msg;
- struct hotplug_msg *tmp_msg;
+ int sock;
+ struct hotplug_msg *msg;
+ int retval;
- new_msg = malloc(sizeof(*new_msg));
- if (new_msg == NULL) {
- dbg("error malloc");
- return -ENOMEM;
+ sock = (int) parm;
+
+ msg = msg_create();
+ if (msg == NULL) {
+ dbg("unable to store message");
+ goto exit;
}
- memcpy(new_msg, msg, sizeof(*new_msg));
- /* store timestamp of queuing */
- new_msg->queue_time = time(NULL);
+ retval = recv(sock, msg, sizeof(struct hotplug_msg), 0);
+ if (retval < 0) {
+ dbg("unable to receive message");
+ goto exit;
+ }
- /* sort message by sequence number into list*/
- list_for_each_entry(tmp_msg, &msg_list, list)
- if (tmp_msg->seqnum > new_msg->seqnum)
- break;
- list_add_tail(&new_msg->list, &tmp_msg->list);
+ if (strncmp(msg->magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) {
+ dbg("message magic '%s' doesn't match, ignore it", msg->magic);
+ goto exit;
+ }
- return 0;
+ pthread_mutex_lock(&msg_lock);
+ msg_queue_insert(msg);
+ pthread_mutex_unlock(&msg_lock);
+
+exit:
+ close(sock);
+ pthread_exit(0);
}
-static void work(void)
+static void sig_handler(int signum)
{
- struct hotplug_msg *msg;
- int msgid;
- key_t key;
- char buf[BUFFER_SIZE];
- int ret;
-
- key = ftok(UDEVD_BIN, IPC_KEY_ID);
- msg = (struct hotplug_msg *) buf;
- msgid = msgget(key, IPC_CREAT);
- if (msgid == -1) {
- dbg("open message queue error");
- exit(1);
- }
- while (1) {
- ret = msgrcv(msgid, (struct msgbuf *) buf, BUFFER_SIZE-4, HOTPLUGMSGTYPE, 0);
- if (ret != -1) {
- dbg("received sequence %d, expected sequence %d", msg->seqnum, expect_seqnum);
- if (msg->seqnum >= expect_seqnum) {
- msg_add_queue(msg);
- msg_dump_queue();
- msg_check_queue();
- continue;
- }
- dbg("too late for event with sequence %d, event skipped ", msg->seqnum);
- } else {
- if (errno == EINTR) {
- msg_check_queue();
- msg_dump_queue();
- delayed_check_queue();
- delayed_dump_queue();
- continue;
- }
- dbg("ipc message receive error '%s'", strerror(errno));
- }
+ switch (signum) {
+ case SIGINT:
+ case SIGTERM:
+ unlink(UDEVD_LOCK);
+ unlink(UDEVD_SOCKET);
+ exit(20 + signum);
+ break;
+ default:
+ dbg("unhandled signal");
}
}
static int one_and_only(void)
{
- char string[100];
-
- lock_file = open(lock_filename, O_RDWR | O_CREAT, 0x640);
+ char string[50];
+ int lock_file;
/* see if we can open */
+ 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;
}
int main(int argc, char *argv[])
{
+ 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;
+
/* only let one version of the daemon run at any one time */
if (one_and_only() != 0)
exit(0);
- /* set up signal handler */
signal(SIGINT, sig_handler);
signal(SIGTERM, sig_handler);
- signal(SIGALRM, sig_handler);
- signal(SIGCHLD, sig_handler);
- work();
- exit(0);
+ memset(&saddr, 0x00, sizeof(saddr));
+ saddr.sun_family = AF_LOCAL;
+ strcpy(saddr.sun_path, UDEVD_SOCKET);
+
+ unlink(UDEVD_SOCKET);
+ 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);
+
+ /* 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 */
+ while (1) {
+ csock = accept(ssock, &caddr, &clen);
+ if (csock < 0) {
+ if (errno == EINTR)
+ continue;
+ dbg("client accept failed\n");
+ }
+ pthread_create(&cli_tid, &thr_attr, client_threads, (void *) csock);
+ }
+exit:
+ close(ssock);
+ unlink(UDEVD_SOCKET);
+ exit(1);
}
projects / systemd / commitdiff