From 01820bcc6fe3281edabd93dd10f2bb0f612ded41 Mon Sep 17 00:00:00 2001
From: Nikias Bassen
Date: Sun, 16 Aug 2009 19:31:43 +0200
Subject: Added lockfile mechanism to prevent multiple running instances.
---
usbmuxd/main.c | 38 +++++++++++++++++++++++++++++++++++++-
1 file changed, 37 insertions(+), 1 deletion(-)
(limited to 'usbmuxd')
diff --git a/usbmuxd/main.c b/usbmuxd/main.c
index ea332a4..88c31da 100644
--- a/usbmuxd/main.c
+++ b/usbmuxd/main.c
@@ -33,6 +33,7 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/stat.h>
+#include <sys/fcntl.h>
#include <getopt.h>
#include <pwd.h>
@@ -42,6 +43,8 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#include "client.h"
static const char *socket_path = "/var/run/usbmuxd";
+static const char *lockfile = "/var/run/usbmuxd.lock";
+
int should_exit;
struct sigaction sa_old;
@@ -268,7 +271,9 @@ static void parse_opts(int argc, char **argv)
int main(int argc, char *argv[])
{
int listenfd;
- int res;
+ int res = 0;
+ FILE *lfd = NULL;
+ struct flock lock;
parse_opts(argc, argv);
@@ -289,6 +294,22 @@ int main(int argc, char *argv[])
set_signal_handlers();
+ lfd = fopen(lockfile, "r");
+ if (lfd) {
+ lock.l_type = 0;
+ lock.l_whence = SEEK_SET;
+ lock.l_start = 0;
+ lock.l_len = 0;
+ fcntl(fileno(lfd), F_GETLK, &lock);
+ fclose(lfd);
+ if (lock.l_type != F_UNLCK) {
+ usbmuxd_log(LL_NOTICE,
+ "another instance is already running (pid %d). exiting.", lock.l_pid);
+ res = -1;
+ goto terminate;
+ }
+ }
+
usbmuxd_log(LL_INFO, "Creating socket");
listenfd = create_socket();
if(listenfd < 0)
@@ -312,6 +333,20 @@ int main(int argc, char *argv[])
}
}
+ // now open the lockfile and place the lock
+ lfd = fopen(lockfile, "w");
+ if (lfd) {
+ lock.l_type = F_WRLCK;
+ lock.l_whence = SEEK_SET;
+ lock.l_start = 0;
+ lock.l_len = 0;
+ if (fcntl(fileno(lfd), F_SETLK, &lock) == -1) {
+ usbmuxd_log(LL_ERROR, "ERROR: lockfile locking failed!");
+ log_disable_syslog();
+ exit(EXIT_FAILURE);
+ }
+ }
+
// drop elevated privileges
if (drop_privileges && (getuid() == 0 || geteuid() == 0)) {
struct passwd *pw = getpwnam("nobody");
@@ -342,6 +377,7 @@ int main(int argc, char *argv[])
usb_shutdown();
device_shutdown();
client_shutdown();
+terminate:
usbmuxd_log(LL_NOTICE, "Shutdown complete");
log_disable_syslog();
--
cgit v1.1-32-gdbae