v4l-conf: check file type before opening it

Let's avoid open the file if it doesn't exist or it is not
a file of the right type.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

1 files changed, 10 insertions, 7 deletions

diff --git a/console/v4l-conf.c b/console/v4l-conf.c
index c38bf16..c96886b 100644
--- a/console/v4l-conf.c
+++ b/console/v4l-conf.c
@@ -141,20 +141,23 @@ dev_open(const char *device, int major)
 	exit(1);
     }
 
-    /* open & check v4l device */
-    if (-1 == (fd = open(device,O_RDWR))) {
-	fprintf(stderr, "can't open %s: %s\n", device, strerror(errno));
+    /* First check if the device is really a devnode of the right type */
+    if (-1 == stat(device, &stb)) {
+	fprintf(stderr, "stat(%s): %s\n", device, strerror(errno));
 	exit(1);
     }
 
-    if (-1 == fstat(fd,&stb)) {
-	fprintf(stderr, "fstat(%s): %s\n", device, strerror(errno));
-	exit(1);
-    }
     if (!S_ISCHR(stb.st_mode) || (major(stb.st_rdev) != major)) {
 	fprintf(stderr, "%s: wrong device\n", device);
 	exit(1);
     }
+
+    /* Then open it */
+    if (-1 == (fd = open(device,O_RDWR))) {
+	fprintf(stderr, "can't open %s: %s\n", device, strerror(errno));
+	exit(1);
+    }
+
     return fd;
 }