X-Git-Url: https://git.danieliu.xyz/?a=blobdiff_plain;f=slock.c;h=cf495551326acd9b63aa2feac5656f70a4f1a5ff;hb=6a52a85a1ac87b29048863d599a8b0f0ee712482;hp=d2c3729a1bc0fe7a31288dd5580f3dae6e38eb1d;hpb=55e827af0fb94f6c2b9e76a7bfe7e98cf697dc7b;p=slock.git

diff --git a/slock.c b/slock.c
index d2c3729..cf49555 100644
--- a/slock.c
+++ b/slock.c
@@ -81,7 +81,7 @@ dontkillme(void)
 		die("buffer too small\n");
 
 	if (fd < 0 || write(fd, value, length) != length || close(fd) != 0)
-		die("cannot disable the out-of-memory killer for this process\n");
+		die("cannot disable the out-of-memory killer for this process (make sure to suid or sgid slock)\n");
 }
 #endif
 
@@ -230,7 +230,7 @@ lockscreen(Display *dpy, int screen)
 	XSetWindowAttributes wa;
 	Cursor invisible;
 
-	if (dpy == NULL || screen < 0 || !(lock = malloc(sizeof(Lock))))
+	if (!running || dpy == NULL || screen < 0 || !(lock = malloc(sizeof(Lock))))
 		return NULL;
 
 	lock->screen = screen;
@@ -253,29 +253,31 @@ lockscreen(Display *dpy, int screen)
 	XMapRaised(dpy, lock->win);
 	if (rr)
 		XRRSelectInput(dpy, lock->win, RRScreenChangeNotifyMask);
+
+	/* Try to grab mouse pointer *and* keyboard, else fail the lock */
 	for (len = 1000; len; len--) {
 		if (XGrabPointer(dpy, lock->root, False, ButtonPressMask | ButtonReleaseMask | PointerMotionMask,
 		    GrabModeAsync, GrabModeAsync, None, invisible, CurrentTime) == GrabSuccess)
 			break;
 		usleep(1000);
 	}
-	if (running && len) {
+	if (!len) {
+		fprintf(stderr, "slock: unable to grab mouse pointer for screen %d\n", screen);
+	} else {
 		for (len = 1000; len; len--) {
-			if (XGrabKeyboard(dpy, lock->root, True, GrabModeAsync, GrabModeAsync, CurrentTime) == GrabSuccess)
-				break;
+			if (XGrabKeyboard(dpy, lock->root, True, GrabModeAsync, GrabModeAsync, CurrentTime) == GrabSuccess) {
+				/* everything fine, we grabbed both inputs */
+				XSelectInput(dpy, lock->root, SubstructureNotifyMask);
+				return lock;
+			}
 			usleep(1000);
 		}
+		fprintf(stderr, "slock: unable to grab keyboard for screen %d\n", screen);
 	}
-
-	running &= (len > 0);
-	if (!running) {
-		unlockscreen(dpy, lock);
-		lock = NULL;
-	} else {
-		XSelectInput(dpy, lock->root, SubstructureNotifyMask);
-	}
-
-	return lock;
+	/* grabbing one of the inputs failed */
+	running = 0;
+	unlockscreen(dpy, lock);
+	return NULL;
 }
 
 static void
@@ -294,7 +296,7 @@ main(int argc, char **argv) {
 	int screen;
 
 	if ((argc == 2) && !strcmp("-v", argv[1]))
-		die("slock-%s, © 2006-2015 slock engineers\n", VERSION);
+		die("slock-%s, © 2006-2016 slock engineers\n", VERSION);
 
 	if ((argc == 2) && !strcmp("-h", argv[1]))
 		usage();