move rules parsing into daemon

The rules files are parsed only once at daemon startup. Every udev
event process will be fork()'d from udevd without exec()'ing the udev
binary. The in-memory rules will be inherited from the daemon itself.

If inotify is available, udevd will reload all rules if any change in
/etc/udev/rules.d/ happens. Otherwise -HUP or "udevcontrol reload_rules"
can be used.

Signed-off-by: Kay Sievers <kay.sievers@suse.de>

1 files changed, 118 insertions, 24 deletions

diff --git a/udevd.c b/udevd.c
index bd1324e4..1f769fbc 100644
--- a/udevd.c
+++ b/udevd.c
@@ -39,6 +39,7 @@
 #include <sys/un.h>
 #include <sys/sysinfo.h>
 #include <sys/stat.h>
+#include <sys/ioctl.h>
 #include <linux/types.h>
 #include <linux/netlink.h>
 
@@ -46,23 +47,26 @@
 #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*/
+struct udev_rules rules;
 static int udevd_sock;
 static int uevent_netlink_sock;
+static int inotify_fd;
 static pid_t sid;
 
 static int signal_pipe[2] = {-1, -1};
 static volatile int sigchilds_waiting;
 static volatile int run_msg_q;
 static volatile int udev_exit;
+static volatile int reload_config;
 static int init_phase = 1;
 static int run_exec_q;
 static int stop_exec_q;
-static char *udev_bin;
 static int event_timeout;
 static int max_childs;
 static int max_childs_running;
@@ -75,7 +79,7 @@ static LIST_HEAD(running_list);
 
 
 #ifdef USE_LOG
-void log_message (int priority, const char *format, ...)
+void log_message(int priority, const char *format, ...)
 {
 	va_list args;
 
@@ -151,10 +155,55 @@ static void msg_queue_insert(struct uevent_msg *msg)
 	return;
 }
 
-/* forks event and removes event from run queue when finished */
+static void asmlinkage udev_event_sig_handler(int signum)
+{
+	if (signum == SIGALRM)
+		exit(1);
+}
+
+static int udev_event_process(struct uevent_msg *msg)
+{
+	struct sigaction act;
+	struct udevice udev;
+	struct name_entry *name_loop;
+	int i;
+	int retval;
+
+	/* 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);
+
+	/* 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
+				run_program(name_loop->name, udev.subsystem, NULL, 0, NULL, (udev_log_priority >= LOG_INFO));
+		}
+	}
+
+	udev_cleanup_device(&udev);
+
+	return 0;
+}
+
+/* runs event and removes event from run queue when finished */
 static void udev_event_run(struct uevent_msg *msg)
 {
-	char *const argv[] = { "udev", msg->subsystem, NULL };
 	pid_t pid;
 	struct sysinfo info;
 
@@ -162,14 +211,22 @@ static void udev_event_run(struct uevent_msg *msg)
 	switch (pid) {
 	case 0:
 		/* child */
-		if (uevent_netlink_sock != -1)
+		if (uevent_netlink_sock > 0)
 			close(uevent_netlink_sock);
+		if (inotify_fd > 0)
+			close(inotify_fd);
 		close(udevd_sock);
+		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);
-		err("exec of child failed");
-		_exit(1);
+		udev_event_process(msg);
+		info("seq %llu finished", msg->seqnum);
+
+		logging_close();
+		exit(0);
 	case -1:
 		err("fork of child failed");
 		msg_queue_delete(msg);
@@ -421,9 +478,8 @@ recheck:
 		if (msg_age >= timeout) {
 			msg_move_exec(loop_msg);
 			goto recheck;
-		} else {
+		} else
 			break;
-		}
 	}
 
 	msg_dump_queue();
@@ -567,6 +623,10 @@ static struct uevent_msg *get_udevd_msg(void)
 		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");
 	}
@@ -640,6 +700,9 @@ static void asmlinkage sig_handler(int signum)
 			/* set flag, then write to pipe if needed */
 			sigchilds_waiting = 1;
 			break;
+		case SIGHUP:
+			reload_config = 1;
+			break;
 	}
 
 	/* write to pipe, which will wakeup select() in our mainloop */
@@ -838,17 +901,11 @@ int main(int argc, char *argv[], char *envp[])
 		err("error fcntl on read pipe: %s", strerror(errno));
 		goto exit;
 	}
-	retval = fcntl(signal_pipe[READ_END], F_SETFD, FD_CLOEXEC);
-	if (retval < 0)
-		err("error fcntl on read pipe: %s", strerror(errno));
 	retval = fcntl(signal_pipe[WRITE_END], F_SETFL, O_NONBLOCK);
 	if (retval < 0) {
 		err("error fcntl on write pipe: %s", strerror(errno));
 		goto exit;
 	}
-	retval = fcntl(signal_pipe[WRITE_END], F_SETFD, FD_CLOEXEC);
-	if (retval < 0)
-		err("error fcntl on write pipe: %s", strerror(errno));
 
 	/* set signal handlers */
 	memset(&act, 0x00, sizeof(struct sigaction));
@@ -861,6 +918,9 @@ int main(int argc, char *argv[], char *envp[])
 	sigaction(SIGCHLD, &act, NULL);
 	sigaction(SIGHUP, &act, NULL);
 
+	/* parse the rules and keep it in memory */
+	udev_rules_init(&rules, 0, 1);
+
 	if (init_udevd_socket() < 0) {
 		if (errno == EADDRINUSE)
 			dbg("another udevd running, exit");
@@ -871,14 +931,12 @@ int main(int argc, char *argv[], char *envp[])
 	}
 
 	if (init_uevent_netlink_sock() < 0)
-		info("uevent socket not available");
+		err("uevent socket not available");
 
-	/* override of forked udev binary, used for testing */
-	udev_bin = getenv("UDEV_BIN");
-	if (udev_bin != NULL)
-		info("udev binary is set to '%s'", udev_bin);
-	else
-		udev_bin = UDEV_BIN;
+	/* 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);
 
 	/* init of expected_seqnum value */
 	value = getenv("UDEVD_EXPECTED_SEQNUM");
@@ -911,6 +969,9 @@ int main(int argc, char *argv[], char *envp[])
 		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);
@@ -924,8 +985,10 @@ int main(int argc, char *argv[], char *envp[])
 		FD_SET(udevd_sock, &readfds);
 		if (uevent_netlink_sock > 0)
 			FD_SET(uevent_netlink_sock, &readfds);
+		if (inotify_fd > 0)
+			FD_SET(inotify_fd, &readfds);
 
-		fdcount = select(UDEV_MAX(udevd_sock, uevent_netlink_sock)+1, &readfds, NULL, NULL, NULL);
+		fdcount = select(UDEV_MAX(uevent_netlink_sock, inotify_fd)+1, &readfds, NULL, NULL, NULL);
 		if (fdcount < 0) {
 			if (errno != EINTR)
 				dbg("error in select: %s", strerror(errno));
@@ -965,6 +1028,33 @@ int main(int argc, char *argv[], char *envp[])
 			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, 0, 1);
+		}
+
 		/* forked child have returned */
 		if (sigchilds_waiting) {
 			sigchilds_waiting = 0;
@@ -990,6 +1080,8 @@ int main(int argc, char *argv[], char *envp[])
 	}
 
 exit:
+	udev_rules_close(&rules);
+
 	if (signal_pipe[READ_END] > 0)
 		close(signal_pipe[READ_END]);
 	if (signal_pipe[WRITE_END] > 0)
@@ -997,6 +1089,8 @@ exit:
 
 	if (udevd_sock > 0)
 		close(udevd_sock);
+	if (inotify_fd > 0)
+		close(inotify_fd);
 	if (uevent_netlink_sock > 0)
 		close(uevent_netlink_sock);