X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udevd.c;h=b7b306131ee5e490f065a4d0a828e84bff8eeb15;hp=2cd3622ce011a5a04630ff8d05595dbd6d53fc81;hb=f4fc0136523afdc3ace865312f816c53694a6b87;hpb=138068d690d79e71239d3e776f01560afbabc1cb

diff --git a/udevd.c b/udevd.c
index 2cd3622ce..b7b306131 100644
--- a/udevd.c
+++ b/udevd.c
@@ -1,5 +1,5 @@
 /*
- * udevd.c - hotplug event serializer
+ * udevd.c - event listener and serializer
  *
  * Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
  * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
@@ -30,142 +30,169 @@
 #include <ctype.h>
 #include <dirent.h>
 #include <fcntl.h>
+#include <syslog.h>
+#include <time.h>
 #include <sys/select.h>
 #include <sys/wait.h>
-#include <sys/time.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/un.h>
-#include <sys/sysinfo.h>
 #include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <linux/types.h>
+#include <linux/netlink.h>
 
 #include "list.h"
 #include "udev_libc_wrapper.h"
 #include "udev.h"
 #include "udev_version.h"
+#include "udev_rules.h"
 #include "udev_utils.h"
 #include "udevd.h"
 #include "logging.h"
 
-/* global variables*/
-static int udevsendsock;
+struct udev_rules rules;
+static int udevd_sock;
+static int uevent_netlink_sock;
+static int inotify_fd;
 static pid_t sid;
 
-static int pipefds[2];
-static long startup_time;
-static unsigned long long expected_seqnum = 0;
+static int signal_pipe[2] = {-1, -1};
 static volatile int sigchilds_waiting;
-static volatile int run_msg_q;
-static volatile int sig_flag;
+static volatile int udev_exit;
+static volatile int reload_config;
 static int run_exec_q;
+static int stop_exec_q;
+static int max_childs;
+static int max_childs_running;
+static char udev_log[32];
 
-static LIST_HEAD(msg_list);
 static LIST_HEAD(exec_list);
 static LIST_HEAD(running_list);
 
-static void exec_queue_manager(void);
-static void msg_queue_manager(void);
-static void user_sighandler(void);
-static void reap_sigchilds(void);
-char *udev_bin;
 
 #ifdef USE_LOG
-void log_message (int level, const char *format, ...)
+void log_message(int priority, const char *format, ...)
 {
-	va_list	args;
+	va_list args;
+
+	if (priority > udev_log_priority)
+		return;
 
 	va_start(args, format);
-	vsyslog(level, format, args);
+	vsyslog(priority, format, args);
 	va_end(args);
 }
 #endif
 
-#define msg_dump(msg) \
-	dbg("msg_dump: sequence %llu, '%s', '%s', '%s'", \
-	msg->seqnum, msg->action, msg->devpath, msg->subsystem);
-
-static void msg_dump_queue(void)
+static void asmlinkage udev_event_sig_handler(int signum)
 {
-#ifdef DEBUG
-	struct hotplug_msg *msg;
-
-	list_for_each_entry(msg, &msg_list, node)
-		dbg("sequence %llu in queue", msg->seqnum);
-#endif
+	if (signum == SIGALRM)
+		exit(1);
 }
 
-static void run_queue_delete(struct hotplug_msg *msg)
+static int udev_event_process(struct uevent_msg *msg)
 {
-	list_del(&msg->node);
-	free(msg);
-}
-
-/* orders the message in the queue by sequence number */
-static void msg_queue_insert(struct hotplug_msg *msg)
-{
-	struct hotplug_msg *loop_msg;
-	struct sysinfo info;
-
-	if (msg->seqnum == 0) {
-		dbg("no SEQNUM, move straight to the exec queue");
-		list_add(&msg->node, &exec_list);
-		run_exec_q = 1;
-		return;
-	}
+	struct sigaction act;
+	struct udevice udev;
+	struct name_entry *name_loop;
+	int i;
+	int retval;
 
-	/* sort message by sequence number into list */
-	list_for_each_entry_reverse(loop_msg, &msg_list, node) {
-		if (loop_msg->seqnum < msg->seqnum)
-			break;
+	/* set signal handlers */
+	memset(&act, 0x00, sizeof(act));
+	act.sa_handler = (void (*)(int)) udev_event_sig_handler;
+	sigemptyset (&act.sa_mask);
+	act.sa_flags = 0;
+	sigaction(SIGALRM, &act, NULL);
 
-		if (loop_msg->seqnum == msg->seqnum) {
-			dbg("ignoring duplicate message seq %llu", msg->seqnum);
-			return;
+	/* trigger timeout to prevent hanging processes */
+	alarm(UDEV_ALARM_TIMEOUT);
+
+	/* reconstruct env from message */
+	for (i = 0; msg->envp[i]; i++)
+		putenv(msg->envp[i]);
+
+	udev_init_device(&udev, msg->devpath, msg->subsystem, msg->action);
+	retval = udev_process_event(&rules, &udev);
+
+	/* run programs collected by RUN-key*/
+	if (!retval) {
+		list_for_each_entry(name_loop, &udev.run_list, node) {
+			if (strncmp(name_loop->name, "socket:", strlen("socket:")) == 0)
+				pass_env_to_socket(&name_loop->name[strlen("socket:")], msg->devpath, msg->action);
+			else
+				if (run_program(name_loop->name, udev.subsystem, NULL, 0, NULL,
+						(udev_log_priority >= LOG_INFO)))
+					retval = -1;
 		}
 	}
 
-	/* store timestamp of queuing */
-	sysinfo(&info);
-	msg->queue_time = info.uptime;
-
-	list_add(&msg->node, &loop_msg->node);
-	dbg("queued message seq %llu", msg->seqnum);
+	udev_cleanup_device(&udev);
 
-	/* run msg queue manager */
-	run_msg_q = 1;
+	return retval;
+}
 
-	return;
+static void msg_queue_delete(struct uevent_msg *msg)
+{
+	list_del(&msg->node);
+	free(msg);
 }
 
-/* forks event and removes event from run queue when finished */
-static void udev_run(struct hotplug_msg *msg)
+static void udev_event_run(struct uevent_msg *msg)
 {
-	char *const argv[] = { "udev", msg->subsystem, NULL };
 	pid_t pid;
+	int retval;
 
 	pid = fork();
 	switch (pid) {
 	case 0:
 		/* child */
-		close(udevsendsock);
+		close(uevent_netlink_sock);
+		close(udevd_sock);
+		if (inotify_fd > 0)
+			close(inotify_fd);
+		close(signal_pipe[READ_END]);
+		close(signal_pipe[WRITE_END]);
 		logging_close();
 
+		logging_init("udevd-event");
 		setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
-		execve(udev_bin, argv, msg->envp);
-		dbg("exec of child failed");
-		_exit(1);
-		break;
+		retval = udev_event_process(msg);
+		info("seq %llu finished", msg->seqnum);
+
+		logging_close();
+		if (retval)
+			exit(1);
+		exit(0);
 	case -1:
-		dbg("fork of child failed");
-		run_queue_delete(msg);
+		err("fork of child failed: %s", strerror(errno));
+		msg_queue_delete(msg);
 		break;
 	default:
 		/* get SIGCHLD in main loop */
-		dbg("==> exec seq %llu [%d] working at '%s'", msg->seqnum, pid, msg->devpath);
+		info("seq %llu forked, pid [%d], '%s' '%s', %ld seconds old",
+		     msg->seqnum, pid,  msg->action, msg->subsystem, time(NULL) - msg->queue_time);
 		msg->pid = pid;
 	}
 }
 
+static void msg_queue_insert(struct uevent_msg *msg)
+{
+	msg->queue_time = time(NULL);
+
+	/* run all events with a timeout set immediately */
+	if (msg->timeout != 0) {
+		list_add_tail(&msg->node, &running_list);
+		udev_event_run(msg);
+		return;
+	}
+
+	list_add_tail(&msg->node, &exec_list);
+	run_exec_q = 1;
+}
+
+/* runs event and removes event from run queue when finished */
 static int running_processes(void)
 {
 	int f;
@@ -178,7 +205,7 @@ static int running_processes(void)
 	if (f == -1)
 		return -1;
 
-	len = read(f, buf, sizeof(buf));
+	len = read(f, buf, sizeof(buf)-1);
 	close(f);
 
 	if (len <= 0)
@@ -227,7 +254,7 @@ static int running_processes_in_session(pid_t session, int limit)
 		if (f == -1)
 			continue;
 
-		len = read(f, line, sizeof(line));
+		len = read(f, line, sizeof(line)-1);
 		close(f);
 
 		if (len <= 0)
@@ -286,132 +313,138 @@ static int compare_devpath(const char *running, const char *waiting)
 }
 
 /* returns still running task for the same device, its parent or its physical device */
-static struct hotplug_msg *running_with_devpath(struct hotplug_msg *msg)
+static int running_with_devpath(struct uevent_msg *msg, int limit)
 {
-	struct hotplug_msg *loop_msg;
-
-	if (msg->devpath == NULL)
-		return NULL;
+	struct uevent_msg *loop_msg;
+	int childs_count = 0;
 
 	list_for_each_entry(loop_msg, &running_list, node) {
-		if (loop_msg->devpath == NULL)
-			continue;
+		if (limit && childs_count++ > limit) {
+			dbg("%llu, maximum number (%i) of child reached", msg->seqnum, childs_count);
+			return 1;
+		}
 
 		/* return running parent/child device event */
-		if (compare_devpath(loop_msg->devpath, msg->devpath) != 0)
-			return loop_msg;
+		if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) {
+			dbg("%llu, child device event still running %llu (%s)",
+			    msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
+			return 2;
+		}
 
 		/* return running physical device event */
 		if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0)
-			if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0)
-				return loop_msg;
+			if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0) {
+				dbg("%llu, physical device event still running %llu (%s)",
+				    msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
+				return 3;
+			}
 	}
 
-	return NULL;
+	return 0;
 }
 
 /* exec queue management routine executes the events and serializes events in the same sequence */
-static void exec_queue_manager(void)
+static void msg_queue_manager(void)
 {
-	struct hotplug_msg *loop_msg;
-	struct hotplug_msg *tmp_msg;
-	struct hotplug_msg *msg;
+	struct uevent_msg *loop_msg;
+	struct uevent_msg *tmp_msg;
 	int running;
 
+	if (list_empty(&exec_list))
+		return;
+
 	running = running_processes();
 	dbg("%d processes runnning on system", running);
 	if (running < 0)
-		running = THROTTLE_MAX_RUNNING_CHILDS;
+		running = max_childs_running;
 
 	list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, node) {
 		/* check running processes in our session and possibly throttle */
-		if (running >= THROTTLE_MAX_RUNNING_CHILDS) {
-			running = running_processes_in_session(sid, THROTTLE_MAX_RUNNING_CHILDS+10);
-			dbg("%d processes running in session", running);
-			if (running >= THROTTLE_MAX_RUNNING_CHILDS) {
-				dbg("delay seq %llu, cause too many processes already running", loop_msg->seqnum);
+		if (running >= max_childs_running) {
+			running = running_processes_in_session(sid, max_childs_running+10);
+			dbg("at least %d processes running in session", running);
+			if (running >= max_childs_running) {
+				dbg("delay seq %llu, too many processes already running", loop_msg->seqnum);
 				return;
 			}
 		}
 
-		msg = running_with_devpath(loop_msg);
-		if (!msg) {
-			/* move event to run list */
-			list_move_tail(&loop_msg->node, &running_list);
-			udev_run(loop_msg);
-			running++;
-			dbg("moved seq %llu to running list", loop_msg->seqnum);
-		} else {
-			dbg("delay seq %llu (%s), cause seq %llu (%s) is still running",
-			    loop_msg->seqnum, loop_msg->devpath, msg->seqnum, msg->devpath);
+		/* don't run two processes for the same devpath and wait for the parent*/
+		if (running_with_devpath(loop_msg, max_childs)) {
+			dbg("delay seq %llu (%s)", loop_msg->seqnum, loop_msg->devpath);
+			continue;
 		}
+
+		/* move event to run list */
+		list_move_tail(&loop_msg->node, &running_list);
+		udev_event_run(loop_msg);
+		running++;
+		dbg("moved seq %llu to running list", loop_msg->seqnum);
 	}
 }
 
-static void msg_move_exec(struct hotplug_msg *msg)
+static struct uevent_msg *get_msg_from_envbuf(const char *buf, int buf_size)
 {
-	list_move_tail(&msg->node, &exec_list);
-	run_exec_q = 1;
-	expected_seqnum = msg->seqnum+1;
-	dbg("moved seq %llu to exec, next expected is %llu",
-		msg->seqnum, expected_seqnum);
-}
+	int bufpos;
+	int i;
+	struct uevent_msg *msg;
+	int major = 0;
+	int minor = 0;
 
-/* msg queue management routine handles the timeouts and dispatches the events */
-static void msg_queue_manager(void)
-{
-	struct hotplug_msg *loop_msg;
-	struct hotplug_msg *tmp_msg;
-	struct sysinfo info;
-	long msg_age = 0;
-	static int timeout = EVENT_INIT_TIMEOUT_SEC;
-	static int init = 1;
-
-	dbg("msg queue manager, next expected is %llu", expected_seqnum);
-recheck:
-	list_for_each_entry_safe(loop_msg, tmp_msg, &msg_list, node) {
-		/* move event with expected sequence to the exec list */
-		if (loop_msg->seqnum == expected_seqnum) {
-			msg_move_exec(loop_msg);
-			continue;
-		}
+	msg = malloc(sizeof(struct uevent_msg) + buf_size);
+	if (msg == NULL)
+		return NULL;
+	memset(msg, 0x00, sizeof(struct uevent_msg) + buf_size);
 
-		/* see if we are in the initialization phase and wait for the very first events */
-		if (init && (info.uptime - startup_time >= INIT_TIME_SEC)) {
-			init = 0;
-			timeout = EVENT_TIMEOUT_SEC;
-			dbg("initialization phase passed, set timeout to %i seconds", EVENT_TIMEOUT_SEC);
-		}
+	/* copy environment buffer and reconstruct envp */
+	memcpy(msg->envbuf, buf, buf_size);
+	bufpos = 0;
+	for (i = 0; (bufpos < buf_size) && (i < UEVENT_NUM_ENVP-2); i++) {
+		int keylen;
+		char *key;
 
-		/* move event with expired timeout to the exec list */
-		sysinfo(&info);
-		msg_age = info.uptime - loop_msg->queue_time;
-		dbg("seq %llu is %li seconds old", loop_msg->seqnum, msg_age);
-		if (msg_age >= timeout) {
-			msg_move_exec(loop_msg);
-			goto recheck;
-		} else {
-			break;
-		}
-	}
+		key = &msg->envbuf[bufpos];
+		keylen = strlen(key);
+		msg->envp[i] = key;
+		bufpos += keylen + 1;
+		dbg("add '%s' to msg.envp[%i]", msg->envp[i], i);
 
-	msg_dump_queue();
+		/* remember some keys for further processing */
+		if (strncmp(key, "ACTION=", 7) == 0)
+			msg->action = &key[7];
+		else if (strncmp(key, "DEVPATH=", 8) == 0)
+			msg->devpath = &key[8];
+		else if (strncmp(key, "SUBSYSTEM=", 10) == 0)
+			msg->subsystem = &key[10];
+		else if (strncmp(key, "SEQNUM=", 7) == 0)
+			msg->seqnum = strtoull(&key[7], NULL, 10);
+		else if (strncmp(key, "PHYSDEVPATH=", 12) == 0)
+			msg->physdevpath = &key[12];
+		else if (strncmp(key, "MAJOR=", 6) == 0)
+			major = strtoull(&key[6], NULL, 10);
+		else if (strncmp(key, "MINOR=", 6) == 0)
+			minor = strtoull(&key[6], NULL, 10);
+		else if (strncmp(key, "TIMEOUT=", 8) == 0)
+			msg->timeout = strtoull(&key[8], NULL, 10);
+	}
+	msg->devt = makedev(major, minor);
+	msg->envp[i++] = "UDEVD_EVENT=1";
+	msg->envp[i] = NULL;
 
-	/* set timeout for remaining queued events */
-	if (list_empty(&msg_list) == 0) {
-		struct itimerval itv = {{0, 0}, {timeout - msg_age, 0}};
-		dbg("next event expires in %li seconds", timeout - msg_age);
-		setitimer(ITIMER_REAL, &itv, NULL);
+	if (!msg->devpath) {
+		info("DEVPATH missing, ignore message");
+		free(msg);
+		return NULL;
 	}
+
+	return msg;
 }
 
-/* receive the udevsend message and do some sanity checks */
-static struct hotplug_msg *get_udevsend_msg(void)
+/* receive the udevd message from userspace */
+static struct uevent_msg *get_udevd_msg(void)
 {
-	static struct udevsend_msg usend_msg;
-	struct hotplug_msg *msg;
-	int bufpos;
-	int i;
+	static struct udevd_msg usend_msg;
+	struct uevent_msg *msg;
 	ssize_t size;
 	struct msghdr smsg;
 	struct cmsghdr *cmsg;
@@ -419,10 +452,11 @@ static struct hotplug_msg *get_udevsend_msg(void)
 	struct ucred *cred;
 	char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
 	int envbuf_size;
+	int *intval;
 
-	memset(&usend_msg, 0x00, sizeof(struct udevsend_msg));
+	memset(&usend_msg, 0x00, sizeof(struct udevd_msg));
 	iov.iov_base = &usend_msg;
-	iov.iov_len = sizeof(struct udevsend_msg);
+	iov.iov_len = sizeof(struct udevd_msg);
 
 	memset(&smsg, 0x00, sizeof(struct msghdr));
 	smsg.msg_iov = &iov;
@@ -430,119 +464,157 @@ static struct hotplug_msg *get_udevsend_msg(void)
 	smsg.msg_control = cred_msg;
 	smsg.msg_controllen = sizeof(cred_msg);
 
-	size = recvmsg(udevsendsock, &smsg, 0);
+	size = recvmsg(udevd_sock, &smsg, 0);
 	if (size <  0) {
 		if (errno != EINTR)
-			dbg("unable to receive udevsend message");
+			err("unable to receive udevd message: %s", strerror(errno));
 		return NULL;
 	}
 	cmsg = CMSG_FIRSTHDR(&smsg);
 	cred = (struct ucred *) CMSG_DATA(cmsg);
 
 	if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
-		dbg("no sender credentials received, message ignored");
+		err("no sender credentials received, message ignored");
 		return NULL;
 	}
 
 	if (cred->uid != 0) {
-		dbg("sender uid=%i, message ignored", cred->uid);
+		err("sender uid=%i, message ignored", cred->uid);
 		return NULL;
 	}
 
 	if (strncmp(usend_msg.magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) {
-		dbg("message magic '%s' doesn't match, ignore it", usend_msg.magic);
+		err("message magic '%s' doesn't match, ignore it", usend_msg.magic);
 		return NULL;
 	}
 
-	envbuf_size = size - offsetof(struct udevsend_msg, envbuf);
-	dbg("envbuf_size=%i", envbuf_size);
-	msg = malloc(sizeof(struct hotplug_msg) + envbuf_size);
-	if (msg == NULL)
-		return NULL;
-
-	memset(msg, 0x00, sizeof(struct hotplug_msg) + envbuf_size);
+	switch (usend_msg.type) {
+	case UDEVD_UEVENT_UDEVSEND:
+	case UDEVD_UEVENT_INITSEND:
+		info("udevd event message received");
+		envbuf_size = size - offsetof(struct udevd_msg, envbuf);
+		dbg("envbuf_size=%i", envbuf_size);
+		msg = get_msg_from_envbuf(usend_msg.envbuf, envbuf_size);
+		if (msg == NULL)
+			return NULL;
+		msg->type = usend_msg.type;
+		return msg;
+	case UDEVD_STOP_EXEC_QUEUE:
+		info("udevd message (STOP_EXEC_QUEUE) received");
+		stop_exec_q = 1;
+		break;
+	case UDEVD_START_EXEC_QUEUE:
+		info("udevd message (START_EXEC_QUEUE) received");
+		stop_exec_q = 0;
+		msg_queue_manager();
+		break;
+	case UDEVD_SET_LOG_LEVEL:
+		intval = (int *) usend_msg.envbuf;
+		info("udevd message (SET_LOG_PRIORITY) received, udev_log_priority=%i", *intval);
+		udev_log_priority = *intval;
+		sprintf(udev_log, "UDEV_LOG=%i", udev_log_priority);
+		putenv(udev_log);
+		break;
+	case UDEVD_SET_MAX_CHILDS:
+		intval = (int *) usend_msg.envbuf;
+		info("udevd message (UDEVD_SET_MAX_CHILDS) received, max_childs=%i", *intval);
+		max_childs = *intval;
+		break;
+	case UDEVD_RELOAD_RULES:
+		info("udevd message (RELOAD_RULES) received");
+		reload_config = 1;
+		break;
+	default:
+		dbg("unknown message type");
+	}
+	return NULL;
+}
 
-	/* copy environment buffer and reconstruct envp */
-	memcpy(msg->envbuf, usend_msg.envbuf, envbuf_size);
-	bufpos = 0;
-	for (i = 0; (bufpos < envbuf_size) && (i < HOTPLUG_NUM_ENVP-2); i++) {
-		int keylen;
-		char *key;
+/* receive the kernel user event message and do some sanity checks */
+static struct uevent_msg *get_netlink_msg(void)
+{
+	struct uevent_msg *msg;
+	int bufpos;
+	ssize_t size;
+	static char buffer[UEVENT_BUFFER_SIZE + 512];
+	char *pos;
 
-		key = &msg->envbuf[bufpos];
-		keylen = strlen(key);
-		msg->envp[i] = key;
-		bufpos += keylen + 1;
-		dbg("add '%s' to msg.envp[%i]", msg->envp[i], i);
+	size = recv(uevent_netlink_sock, &buffer, sizeof(buffer), 0);
+	if (size <  0) {
+		if (errno != EINTR)
+			err("unable to receive udevd message: %s", strerror(errno));
+		return NULL;
+	}
 
-		/* remember some keys for further processing */
-		if (strncmp(key, "ACTION=", 7) == 0)
-			msg->action = &key[7];
+	if ((size_t)size > sizeof(buffer)-1)
+		size = sizeof(buffer)-1;
+	buffer[size] = '\0';
+	dbg("uevent_size=%zi", size);
 
-		if (strncmp(key, "DEVPATH=", 8) == 0)
-			msg->devpath = &key[8];
+	/* start of event payload */
+	bufpos = strlen(buffer)+1;
+	msg = get_msg_from_envbuf(&buffer[bufpos], size-bufpos);
+	if (msg == NULL)
+		return NULL;
+	msg->type = UDEVD_UEVENT_NETLINK;
 
-		if (strncmp(key, "SUBSYSTEM=", 10) == 0)
-			msg->subsystem = &key[10];
+	/* validate message */
+	pos = strchr(buffer, '@');
+	if (pos == NULL) {
+		err("invalid uevent '%s'", buffer);
+		free(msg);
+		return NULL;
+	}
+	pos[0] = '\0';
 
-		if (strncmp(key, "SEQNUM=", 7) == 0)
-			msg->seqnum = strtoull(&key[7], NULL, 10);
+	if (msg->action == NULL) {
+		info("no ACTION in payload found, skip event '%s'", buffer);
+		free(msg);
+		return NULL;
+	}
 
-		if (strncmp(key, "PHYSDEVPATH=", 12) == 0)
-			msg->physdevpath = &key[12];
+	if (strcmp(msg->action, buffer) != 0) {
+		err("ACTION in payload does not match uevent, skip event '%s'", buffer);
+		free(msg);
+		return NULL;
 	}
-	msg->envp[i++] = "UDEVD_EVENT=1";
-	msg->envp[i] = NULL;
 
 	return msg;
 }
 
 static void asmlinkage sig_handler(int signum)
 {
-	int rc;
-
 	switch (signum) {
 		case SIGINT:
 		case SIGTERM:
-			exit(20 + signum);
-			break;
-		case SIGALRM:
-			/* set flag, then write to pipe if needed */
-			run_msg_q = 1;
-			goto do_write;
+			udev_exit = 1;
 			break;
 		case SIGCHLD:
 			/* set flag, then write to pipe if needed */
 			sigchilds_waiting = 1;
-			goto do_write;
+			break;
+		case SIGHUP:
+			reload_config = 1;
 			break;
 	}
 
-do_write:
-	/* if pipe is empty, write to pipe to force select to return
-	 * immediately when it gets called
-	 */
-	if (!sig_flag) {
-		rc = write(pipefds[1],&signum,sizeof(signum));
-		if (rc >= 0)
-			sig_flag = 1;
-	}
+	/* write to pipe, which will wakeup select() in our mainloop */
+	write(signal_pipe[WRITE_END], "", 1);
 }
 
-static void udev_done(int pid)
+static void udev_done(int pid, int exitstatus)
 {
 	/* find msg associated with pid and delete it */
-	struct hotplug_msg *msg;
+	struct uevent_msg *msg;
 
 	list_for_each_entry(msg, &running_list, node) {
 		if (msg->pid == pid) {
-			dbg("<== exec seq %llu came back", msg->seqnum);
-			run_queue_delete(msg);
+			info("seq %llu, pid [%d] exit with %i, %ld seconds old", msg->seqnum, msg->pid,
+			     exitstatus, time(NULL) - msg->queue_time);
+			msg->exitstatus = exitstatus;
+			msg_queue_delete(msg);
 
-			/* we want to run the exec queue manager since there may
-			 * be events waiting with the devpath of the one that
-			 * just finished
-			 */
+			/* there may be events waiting with the same devpath */
 			run_exec_q = 1;
 			return;
 		}
@@ -551,33 +623,25 @@ static void udev_done(int pid)
 
 static void reap_sigchilds(void)
 {
-	while(1) {
-		int pid = waitpid(-1, NULL, WNOHANG);
-		if ((pid == -1) || (pid == 0))
-			break;
-		udev_done(pid);
-	}
-}
-
-/* just read everything from the pipe and clear the flag,
- * the flags was set in the signal handler
- */
-static void user_sighandler(void)
-{
-	int sig;
+	pid_t pid;
+	int status;
 
-	while(1) {
-		int rc = read(pipefds[0], &sig, sizeof(sig));
-		if (rc < 0)
+	while (1) {
+		pid = waitpid(-1, &status, WNOHANG);
+		if (pid <= 0)
 			break;
-
-		sig_flag = 0;
+		if (WIFEXITED(status))
+			status = WEXITSTATUS(status);
+		else
+			status = 0;
+		udev_done(pid, status);
 	}
 }
 
-static int init_udevsend_socket(void)
+static int init_udevd_socket(void)
 {
 	struct sockaddr_un saddr;
+	const int buffersize = 16 * 1024 * 1024;
 	socklen_t addrlen;
 	const int feature_on = 1;
 	int retval;
@@ -588,194 +652,326 @@ static int init_udevsend_socket(void)
 	strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH);
 	addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
 
-	udevsendsock = socket(AF_LOCAL, SOCK_DGRAM, 0);
-	if (udevsendsock == -1) {
-		dbg("error getting socket, %s", strerror(errno));
+	udevd_sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
+	if (udevd_sock == -1) {
+		err("error getting socket: %s", strerror(errno));
 		return -1;
 	}
 
+	/* set receive buffersize */
+	setsockopt(udevd_sock, SOL_SOCKET, SO_RCVBUFFORCE, &buffersize, sizeof(buffersize));
+
 	/* the bind takes care of ensuring only one copy running */
-	retval = bind(udevsendsock, (struct sockaddr *) &saddr, addrlen);
+	retval = bind(udevd_sock, (struct sockaddr *) &saddr, addrlen);
 	if (retval < 0) {
-		dbg("bind failed, %s", strerror(errno));
-		close(udevsendsock);
+		err("bind failed: %s", strerror(errno));
 		return -1;
 	}
 
 	/* enable receiving of the sender credentials */
-	setsockopt(udevsendsock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on));
+	setsockopt(udevd_sock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on));
+
+	return 0;
+}
+
+static int init_uevent_netlink_sock(void)
+{
+	struct sockaddr_nl snl;
+	const int buffersize = 16 * 1024 * 1024;
+	int retval;
+
+	memset(&snl, 0x00, sizeof(struct sockaddr_nl));
+	snl.nl_family = AF_NETLINK;
+	snl.nl_pid = getpid();
+	snl.nl_groups = 0xffffffff;
+
+	uevent_netlink_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
+	if (uevent_netlink_sock == -1) {
+		err("error getting socket: %s", strerror(errno));
+		return -1;
+	}
+
+	/* set receive buffersize */
+	setsockopt(uevent_netlink_sock, SOL_SOCKET, SO_RCVBUFFORCE, &buffersize, sizeof(buffersize));
 
+	retval = bind(uevent_netlink_sock, (struct sockaddr *) &snl, sizeof(struct sockaddr_nl));
+	if (retval < 0) {
+		err("bind failed: %s", strerror(errno));
+		close(uevent_netlink_sock);
+		uevent_netlink_sock = -1;
+		return -1;
+	}
 	return 0;
 }
 
 int main(int argc, char *argv[], char *envp[])
 {
-	struct sysinfo info;
-	int maxsockplus;
 	int retval;
 	int fd;
 	struct sigaction act;
 	fd_set readfds;
-	const char *udevd_expected_seqnum;
+	const char *value;
+	int daemonize = 0;
+	int i;
+	int rc = 0;
+	int maxfd;
+
+	/* redirect std fd's, if the kernel forks us, we don't have them at all */
+	fd = open("/dev/null", O_RDWR);
+	if (fd >= 0) {
+		if (fd != STDIN_FILENO)
+			dup2(fd, STDIN_FILENO);
+		if (fd != STDOUT_FILENO)
+			dup2(fd, STDOUT_FILENO);
+		if (fd != STDERR_FILENO)
+			dup2(fd, STDERR_FILENO);
+		if (fd > STDERR_FILENO)
+			close(fd);
+	}
 
 	logging_init("udevd");
+	if (fd < 0)
+		err("fatal, could not open /dev/null: %s", strerror(errno));
+
+	udev_init_config();
 	dbg("version %s", UDEV_VERSION);
 
 	if (getuid() != 0) {
-		dbg("need to be root, exit");
+		err("need to be root, exit");
 		goto exit;
 	}
 
-	/* daemonize on request */
-	if (argc == 2 && strcmp(argv[1], "-d") == 0) {
+	/* parse commandline options */
+	for (i = 1 ; i < argc; i++) {
+		char *arg = argv[i];
+		if (strcmp(arg, "--daemon") == 0 || strcmp(arg, "-d") == 0) {
+			info("will daemonize");
+			daemonize = 1;
+		}
+		if (strcmp(arg, "--stop-exec-queue") == 0) {
+			info("will not execute events until START_EXEC_QUEUE is received");
+			stop_exec_q = 1;
+		}
+	}
+
+	/* init sockets to receive events */
+	if (init_udevd_socket() < 0) {
+		if (errno == EADDRINUSE) {
+			err("another udevd running, exit");
+			rc = 1;
+		} else {
+			err("error initializing udevd socket: %s", strerror(errno));
+			rc = 2;
+		}
+		goto exit;
+	}
+
+	if (init_uevent_netlink_sock() < 0) {
+		err("uevent socket not available");
+		rc = 3;
+		goto exit;
+	}
+
+	/* parse the rules and keep it in memory */
+	udev_rules_init(&rules, 1);
+
+	if (daemonize) {
 		pid_t pid;
 
 		pid = fork();
 		switch (pid) {
 		case 0:
-			dbg("damonized fork running");
+			dbg("daemonized fork running");
 			break;
 		case -1:
-			dbg("fork of daemon failed");
+			err("fork of daemon failed: %s", strerror(errno));
+			rc = 4;
 			goto exit;
 		default:
-			logging_close();
-			exit(0);
+			dbg("child [%u] running, parent exits", pid);
+			goto exit;
 		}
 	}
 
-	/* become session leader */
-	sid = setsid();
-	dbg("our session is %d", sid);
+	/* set scheduling priority for the daemon */
+	setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 
-	/* make sure we don't lock any path */
 	chdir("/");
-	umask(umask(077) | 022);
+	umask(022);
 
-	/*set a reasonable scheduling priority for the daemon */
-	setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
+	/* become session leader */
+	sid = setsid();
+	dbg("our session is %d", sid);
 
-	/* Set fds to dev/null */
-	fd = open( "/dev/null", O_RDWR );
-	if (fd >= 0)  {
-		dup2(fd, 0);
-		dup2(fd, 1);
-		dup2(fd, 2);
-		if (fd > 2)
-			close(fd);
-	} else
-		dbg("error opening /dev/null %s", strerror(errno));
+	/* OOM_DISABLE == -17 */
+	fd = open("/proc/self/oom_adj", O_RDWR);
+	if (fd < 0)
+		err("error disabling OOM: %s", strerror(errno));
+	else {
+		write(fd, "-17", 3);
+		close(fd);
+	}
 
 	/* setup signal handler pipe */
-	retval = pipe(pipefds);
+	retval = pipe(signal_pipe);
 	if (retval < 0) {
-		dbg("error getting pipes: %s", strerror(errno));
+		err("error getting pipes: %s", strerror(errno));
 		goto exit;
 	}
-
-	retval = fcntl(pipefds[0], F_SETFL, O_NONBLOCK);
+	retval = fcntl(signal_pipe[READ_END], F_SETFL, O_NONBLOCK);
 	if (retval < 0) {
-		dbg("error fcntl on read pipe: %s", strerror(errno));
+		err("error fcntl on read pipe: %s", strerror(errno));
 		goto exit;
 	}
-	retval = fcntl(pipefds[0], F_SETFD, FD_CLOEXEC);
-	if (retval < 0)
-		dbg("error fcntl on read pipe: %s", strerror(errno));
-
-	retval = fcntl(pipefds[1], F_SETFL, O_NONBLOCK);
+	retval = fcntl(signal_pipe[WRITE_END], F_SETFL, O_NONBLOCK);
 	if (retval < 0) {
-		dbg("error fcntl on write pipe: %s", strerror(errno));
+		err("error fcntl on write pipe: %s", strerror(errno));
 		goto exit;
 	}
-	retval = fcntl(pipefds[1], F_SETFD, FD_CLOEXEC);
-	if (retval < 0)
-		dbg("error fcntl on write pipe: %s", strerror(errno));
 
 	/* set signal handlers */
 	memset(&act, 0x00, sizeof(struct sigaction));
-	act.sa_handler = (void (*) (int))sig_handler;
+	act.sa_handler = (void (*)(int)) sig_handler;
 	sigemptyset(&act.sa_mask);
 	act.sa_flags = SA_RESTART;
 	sigaction(SIGINT, &act, NULL);
 	sigaction(SIGTERM, &act, NULL);
-	sigaction(SIGALRM, &act, NULL);
 	sigaction(SIGCHLD, &act, NULL);
+	sigaction(SIGHUP, &act, NULL);
 
-	if (init_udevsend_socket() < 0) {
-		if (errno == EADDRINUSE)
-			dbg("another udevd running, exit");
-		else
-			dbg("error initialising udevsend socket: %s", strerror(errno));
-
-		goto exit;
-	}
+	/* watch rules directory */
+	inotify_fd = inotify_init();
+	if (inotify_fd > 0)
+		inotify_add_watch(inotify_fd, udev_rules_filename, IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
 
-	/* possible override of udev binary, used for testing */
-	udev_bin = getenv("UDEV_BIN");
-	if (udev_bin != NULL)
-		dbg("udev binary is set to '%s'", udev_bin);
+	/* maximum limit of forked childs */
+	value = getenv("UDEVD_MAX_CHILDS");
+	if (value)
+		max_childs = strtoul(value, NULL, 10);
 	else
-		udev_bin = UDEV_BIN;
-
-	/* possible init of expected_seqnum value */
-	udevd_expected_seqnum = getenv("UDEVD_EXPECTED_SEQNUM");
-	if (udevd_expected_seqnum != NULL) {
-		expected_seqnum = strtoull(udevd_expected_seqnum, NULL, 10);
-		dbg("initialize expected_seqnum to %llu", expected_seqnum);
-	}
-
-	/* get current time to provide shorter timeout on startup */
-	sysinfo(&info);
-	startup_time = info.uptime;
-
-	FD_ZERO(&readfds);
-	FD_SET(udevsendsock, &readfds);
-	FD_SET(pipefds[0], &readfds);
-	maxsockplus = udevsendsock+1;
-	while (1) {
-		struct hotplug_msg *msg;
-
-		fd_set workreadfds = readfds;
-		retval = select(maxsockplus, &workreadfds, NULL, NULL, NULL);
+		max_childs = UDEVD_MAX_CHILDS;
+	info("initialize max_childs to %u", max_childs);
 
-		if (retval < 0) {
+	/* start to throttle forking if maximum number of _running_ childs is reached */
+	value = getenv("UDEVD_MAX_CHILDS_RUNNING");
+	if (value)
+		max_childs_running = strtoull(value, NULL, 10);
+	else
+		max_childs_running = UDEVD_MAX_CHILDS_RUNNING;
+	info("initialize max_childs_running to %u", max_childs_running);
+
+	/* clear environment for forked event processes */
+	clearenv();
+
+	/* export log_priority , as called programs may want to follow that setting */
+	sprintf(udev_log, "UDEV_LOG=%i", udev_log_priority);
+	putenv(udev_log);
+
+	maxfd = udevd_sock;
+	maxfd = UDEV_MAX(maxfd, uevent_netlink_sock);
+	maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
+	maxfd = UDEV_MAX(maxfd, inotify_fd);
+
+	while (!udev_exit) {
+		struct uevent_msg *msg;
+		int fdcount;
+
+		FD_ZERO(&readfds);
+		FD_SET(signal_pipe[READ_END], &readfds);
+		FD_SET(udevd_sock, &readfds);
+		FD_SET(uevent_netlink_sock, &readfds);
+		if (inotify_fd > 0)
+			FD_SET(inotify_fd, &readfds);
+
+		fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL);
+		if (fdcount < 0) {
 			if (errno != EINTR)
-				dbg("error in select: %s", strerror(errno));
+				err("error in select: %s", strerror(errno));
 			continue;
 		}
 
-		if (FD_ISSET(udevsendsock, &workreadfds)) {
-			msg = get_udevsend_msg();
+		/* get user socket message */
+		if (FD_ISSET(udevd_sock, &readfds)) {
+			msg = get_udevd_msg();
+			if (msg) {
+				if (msg->type == UDEVD_UEVENT_UDEVSEND && msg->seqnum != 0) {
+					info("skip non-kernel message with SEQNUM");
+					free(msg);
+				} else
+					msg_queue_insert(msg);
+			}
+		}
+
+		/* get kernel netlink message */
+		if (FD_ISSET(uevent_netlink_sock, &readfds)) {
+			msg = get_netlink_msg();
 			if (msg)
 				msg_queue_insert(msg);
 		}
 
-		if (FD_ISSET(pipefds[0], &workreadfds))
-			user_sighandler();
+		/* received a signal, clear our notification pipe */
+		if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
+			char buf[256];
+
+			read(signal_pipe[READ_END], &buf, sizeof(buf));
+		}
+
+		/* rules directory inotify watch */
+		if ((inotify_fd > 0) && FD_ISSET(inotify_fd, &readfds)) {
+			int nbytes;
+
+			/* discard all possible events, we can just reload the config */
+			if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes) {
+				char *buf;
+
+				reload_config = 1;
+				buf = malloc(nbytes);
+				if (!buf) {
+					err("error getting buffer for inotify, disable watching");
+					close(inotify_fd);
+					inotify_fd = -1;
+				}
+				read(inotify_fd, buf, nbytes);
+				free(buf);
+			}
+		}
 
+		/* rules changed, set by inotify or a signal*/
+		if (reload_config) {
+			reload_config = 0;
+			udev_rules_close(&rules);
+			udev_rules_init(&rules, 1);
+		}
+
+		/* forked child has returned */
 		if (sigchilds_waiting) {
 			sigchilds_waiting = 0;
 			reap_sigchilds();
 		}
 
-		if (run_msg_q) {
-			run_msg_q = 0;
-			msg_queue_manager();
-		}
-
 		if (run_exec_q) {
-			 /* clean up running_list before calling exec_queue_manager() */
-			if (sigchilds_waiting) {
-				sigchilds_waiting = 0;
-				reap_sigchilds();
-			}
-
 			run_exec_q = 0;
-			exec_queue_manager();
+			if (!stop_exec_q)
+				msg_queue_manager();
 		}
 	}
 
 exit:
+	udev_rules_close(&rules);
+
+	if (signal_pipe[READ_END] > 0)
+		close(signal_pipe[READ_END]);
+	if (signal_pipe[WRITE_END] > 0)
+		close(signal_pipe[WRITE_END]);
+
+	if (udevd_sock > 0)
+		close(udevd_sock);
+	if (inotify_fd > 0)
+		close(inotify_fd);
+	if (uevent_netlink_sock > 0)
+		close(uevent_netlink_sock);
+
 	logging_close();
-	return 1;
+
+	return rc;
 }