Use O_CLOEXEC when creating FDs

This is needed so that new processes (created with fork+exec) don't
inherit open files, which can be important for a number of reasons.

Since O_CLOEXEC is relatively new (POSIX.1-2008, before that Linux
specific), we #define it to 0 in io.h to prevent compilation errors on
older/crappy systems. At least this is the plan.

input.c creates a pipe. For that, add a mp_set_cloexec() function (which
is based on Weston's code in vo_wayland.c, but more correct). We could
use pipe2() instead, but that is Linux specific. Technically, we have a
race condition, but it won't matter.

1 files changed, 3 insertions, 3 deletions

diff --git a/stream/stream_file.c b/stream/stream_file.c
index b638fdddf0..e72355d387 100644
--- a/stream/stream_file.c
+++ b/stream/stream_file.c
@@ -101,11 +101,11 @@ static int open_f(stream_t *stream, int mode)
     };
     stream->priv = priv;
 
-    mode_t m = 0;
+    mode_t m = O_CLOEXEC;
     if (mode == STREAM_READ)
-        m = O_RDONLY;
+        m |= O_RDONLY;
     else if (mode == STREAM_WRITE)
-        m = O_RDWR | O_CREAT | O_TRUNC;
+        m |= O_RDWR | O_CREAT | O_TRUNC;
     else {
         mp_msg(MSGT_OPEN, MSGL_ERR, "[file] Unknown open mode %d\n", mode);
         return STREAM_UNSUPPORTED;