Re: move udev-rules parsing into the daemon

[Kay Sievers <kay.sievers@vrfy.org>]

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On Fri, Aug 12, 2005 at 11:04:11AM -0700, Greg KH wrote:
> On Fri, Aug 12, 2005 at 04:49:36AM +0200, Kay Sievers wrote:
> > On Fri, Aug 12, 2005 at 01:06:24AM +0200, Kay Sievers wrote:
> > > On Wed, Aug 10, 2005 at 11:13:14PM -0700, Greg KH wrote:
> > > > On Tue, Aug 09, 2005 at 04:30:07AM +0200, Kay Sievers wrote:
> > > > > Here we go with the Inotify version on top of the current tree.
> > > > > I've added some stuff to our libc-wrapper file until the inotify
> > > > > headers have reached glibc and we can just add an #include to
> > > > > udevd.c for it.
> > > > 
> > > > Looks good to me.
> > > 
> > > Here is a version on top of the new 066.
> > 
> > New version to compile successfully with glibc and klibc on:
> >   i386, x86_64, ppc, ppc64, ia64, s390, s390x
> 
> I'm happy with this, care to add this to your git tree, so I can add it
> to mainline?  Any one else have any objections to this?

Here is a version on top of the current release. We hopefully fixed all
remaining issues with today's version 068 so this can go into mainline
next week.

Thanks,
Kay

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diff --git a/etc/udev/udev.conf.in b/etc/udev/udev.conf.in
--- a/etc/udev/udev.conf.in
+++ b/etc/udev/udev.conf.in
@@ -9,6 +9,8 @@ udev_db="@udevdir@/.udevdb"
 # The name and location of the udev rules file(s).
 udev_rules="@configdir@/rules.d"
 
-# The syslog(3) priority: "err", "info", or the numerical value.
+# The initial syslog(3) priority: "err", "info", "debug" or its
+# numerical equivalent. For runtime debugging, change the daemons
+# internal state with: "udevcontrol log_priority=<value>".
 udev_log="err"
 
diff --git a/klibc/klibc/SYSCALLS.def b/klibc/klibc/SYSCALLS.def
--- a/klibc/klibc/SYSCALLS.def
+++ b/klibc/klibc/SYSCALLS.def
@@ -114,6 +114,9 @@ int lchown32,lchown::lchown(const char *
 int getcwd::__getcwd(char *, size_t)
 <?> int utime(const char *, const struct utimbuf *)
 <?> int utimes(const char *, const struct timeval *)
+<?> int inotify_init(void)
+<?> int inotify_add_watch(int, const char *, __u32)
+<?> int inotify_rm_watch(int, __u32)
 
 ;
 ; I/O operations
diff --git a/udev_libc_wrapper.h b/udev_libc_wrapper.h
--- a/udev_libc_wrapper.h
+++ b/udev_libc_wrapper.h
@@ -25,6 +25,75 @@
 #include <string.h>
 #include <unistd.h>
 #include <linux/types.h>
+#include <sys/syscall.h>
+
+/* needed until Inotify! reaches libc */
+#ifndef __NR_inotify_init
+#if defined(__i386__)
+# define __NR_inotify_init	291
+# define __NR_inotify_add_watch	292
+# define __NR_inotify_rm_watch	293
+#elif defined(__x86_64__)
+# define __NR_inotify_init	253
+# define __NR_inotify_add_watch	254
+# define __NR_inotify_rm_watch	255
+#elif defined(__powerpc__) || defined(__powerpc64__)
+# define __NR_inotify_init	275
+# define __NR_inotify_add_watch	276
+# define __NR_inotify_rm_watch	277
+#elif defined (__ia64__)
+# define __NR_inotify_init	1277
+# define __NR_inotify_add_watch	1278
+# define __NR_inotify_rm_watch	1279
+#elif defined (__s390__)
+# define __NR_inotify_init	284
+# define __NR_inotify_add_watch	285
+# define __NR_inotify_rm_watch	286
+#elif defined (__alpha__)
+# define __NR_inotify_init	444
+# define __NR_inotify_add_watch	445
+# define __NR_inotify_rm_watch	446
+#elif defined (__sparc__) || defined (__sparc64__)
+# define __NR_inotify_init	151
+# define __NR_inotify_add_watch	152
+# define __NR_inotify_rm_watch	156
+#elif defined (__arm__)
+# define __NR_inotify_init	316
+# define __NR_inotify_add_watch	317
+# define __NR_inotify_rm_watch	318
+#elif defined (__sh__)
+# define __NR_inotify_init	290
+# define __NR_inotify_add_watch	291
+# define __NR_inotify_rm_watch	292
+#else
+# error "Unsupported architecture!"
+#endif
+#endif /* __NR_inotify_init */
+
+#ifdef __KLIBC__
+static inline _syscall0(int, inotify_init);
+static inline _syscall3(int, inotify_add_watch, int, fd, const char*, name, __u32, mask);
+#else
+static inline int inotify_init(void)
+{
+	return syscall(__NR_inotify_init);
+}
+
+static inline int inotify_add_watch(int fd, const char *name, __u32 mask)
+{
+	return syscall(__NR_inotify_add_watch, fd, name, mask);
+}
+#endif
+
+/* needed until it reaches libc */
+#ifndef IN_CREATE
+#define IN_CREATE		0x00000100	/* Subfile was created */
+#define IN_MOVED_FROM		0x00000040	/* File was moved from X */
+#define IN_MOVED_TO		0x00000080	/* File was moved to Y */
+#define IN_DELETE		0x00000200	/* Subfile was deleted */
+#define IN_CLOSE_WRITE		0x00000008	/* Writtable file was closed */
+#define IN_MOVE			(IN_MOVED_FROM | IN_MOVED_TO) /* moves */
+#endif
 
 /* needed for our signal handlers to work */
 #undef asmlinkage
diff --git a/udevcontrol.c b/udevcontrol.c
--- a/udevcontrol.c
+++ b/udevcontrol.c
@@ -89,6 +89,8 @@ int main(int argc, char *argv[], char *e
 			usend_msg.type = UDEVD_STOP_EXEC_QUEUE;
 		else if (!strcmp(arg, "start_exec_queue"))
 			usend_msg.type = UDEVD_START_EXEC_QUEUE;
+		else if (!strcmp(arg, "reload_rules"))
+			usend_msg.type = UDEVD_RELOAD_RULES;
 		else if (!strncmp(arg, "log_priority=", strlen("log_priority="))) {
 			intval = (int *) usend_msg.envbuf;
 			val = &arg[strlen("log_priority=")];
@@ -106,6 +108,7 @@ int main(int argc, char *argv[], char *e
 				"  log_priority=<level> set the udev log level for the daemon\n"
 				"  stop_exec_queue      keep udevd from executing events, queue only\n"
 				"  start_exec_queue     execute events, flush queue\n"
+				"  reload_rules         reloads the rules files\n"
 				"  max_childs=<N>       maximum number of childs running at the same time\n"
 				"  --help               print this help text\n\n");
 			exit(0);
diff --git a/udevd.c b/udevd.c
--- 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>
 
@@ -46,13 +47,16 @@
 #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 pipefds[2] = {-1, -1};
@@ -60,10 +64,10 @@ 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 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;
@@ -76,7 +80,7 @@ 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;
 
@@ -161,10 +165,55 @@ static void msg_queue_insert(struct ueve
 	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;
 
@@ -172,14 +221,20 @@ static void udev_event_run(struct uevent
 	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);
 		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);
@@ -547,7 +602,7 @@ static struct uevent_msg *get_udevd_msg(
 	switch (usend_msg.type) {
 	case UDEVD_UEVENT_UDEVSEND:
 	case UDEVD_UEVENT_INITSEND:
-		dbg("udevd event message received");
+		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);
@@ -576,6 +631,10 @@ static struct uevent_msg *get_udevd_msg(
 		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");
 	}
@@ -651,6 +710,9 @@ static void asmlinkage sig_handler(int s
 			/* set flag, then write to pipe if needed */
 			sigchilds_waiting = 1;
 			break;
+		case SIGHUP:
+			reload_config = 1;
+			break;
 	}
 
 	/* if pipe is empty, write to pipe to force select to return,
@@ -852,17 +914,11 @@ int main(int argc, char *argv[], char *e
 		err("error fcntl on read pipe: %s", strerror(errno));
 		goto exit;
 	}
-	retval = fcntl(pipefds[0], F_SETFD, FD_CLOEXEC);
-	if (retval < 0)
-		err("error fcntl on read pipe: %s", strerror(errno));
 	retval = fcntl(pipefds[1], F_SETFL, O_NONBLOCK);
 	if (retval < 0) {
 		err("error fcntl on write pipe: %s", strerror(errno));
 		goto exit;
 	}
-	retval = fcntl(pipefds[1], 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));
@@ -875,24 +931,24 @@ int main(int argc, char *argv[], char *e
 	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");
 		else
 			dbg("error initialising udevd socket: %s", strerror(errno));
-
 		goto exit;
 	}
 
 	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");
@@ -925,6 +981,9 @@ int main(int argc, char *argv[], char *e
 		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(log, "UDEV_LOG=%i", udev_log_priority);
 	putenv(log);
@@ -938,8 +997,10 @@ int main(int argc, char *argv[], char *e
 		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));
@@ -986,6 +1047,33 @@ int main(int argc, char *argv[], char *e
 			sig_flag = 0;
 		}
 
+		/* rules directory inotify watch */
+		if (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) {
+			udev_rules_close(&rules);
+			udev_rules_init(&rules, 0, 1);
+			reload_config = 0;
+		}
+
 		/* forked child have returned */
 		if (sigchilds_waiting) {
 			sigchilds_waiting = 0;
@@ -1011,6 +1099,8 @@ int main(int argc, char *argv[], char *e
 	}
 
 exit:
+	udev_rules_close(&rules);
+
 	if (pipefds[0] > 0)
 		close(pipefds[0]);
 	if (pipefds[1] > 0)
@@ -1018,6 +1108,8 @@ exit:
 
 	if (udevd_sock > 0)
 		close(udevd_sock);
+	if (inotify_fd > 0)
+		close(inotify_fd);
 	if (uevent_netlink_sock > 0)
 		close(uevent_netlink_sock);
 
diff --git a/udevd.h b/udevd.h
--- a/udevd.h
+++ b/udevd.h
@@ -54,6 +54,7 @@ enum udevd_msg_type {
 	UDEVD_START_EXEC_QUEUE,
 	UDEVD_SET_LOG_LEVEL,
 	UDEVD_SET_MAX_CHILDS,
+	UDEVD_RELOAD_RULES,
 };