diff options
| -rw-r--r-- | usbmuxd/main.c | 38 |
1 files changed, 37 insertions, 1 deletions
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(); |