Mark simple file and socket descriptors as uninheritable.

This patch creates two utility functions:

  int open_cloexec(pathname, flags)
  int create_cloexec(pathname, flags, mode)

These return a file descriptor with the CLOEXEC flag set, to ensure
that the descriptor is not inherited across a fork/exec operation.

The sockets returned by:

   _x_io_tcp_connect_ipv4()
   _x_io_tcp_connect()

now also have their CLOEXEC flag set.

1 files changed, 39 insertions, 0 deletions

diff --git a/src/xine-utils/utils.c b/src/xine-utils/utils.c
index 2f62c95a8..f5d5a0ff3 100644
--- a/src/xine-utils/utils.c
+++ b/src/xine-utils/utils.c
@@ -38,6 +38,7 @@
 #include <sys/time.h>
 #include <time.h>
 #include <unistd.h>
+#include <fcntl.h>
 
 #if HAVE_EXECINFO_H
 #include <execinfo.h>
@@ -56,6 +57,10 @@
 #include <windows.h>
 #endif
 
+#ifndef O_CLOEXEC
+#  define O_CLOEXEC  0
+#endif
+
 typedef struct {
   char                    *language;     /* name of the locale */
   char                    *encoding;     /* typical encoding */
@@ -697,3 +702,37 @@ char *xine_strcat_realloc (char **dest, char *append)
     strcat (*dest = newstr, append);
   return newstr;
 }
+
+
+static int set_close_on_execute(int fd)
+{
+#ifndef WIN32
+  return fcntl(fd, F_SETFD, FD_CLOEXEC);
+#else
+  return SetHandleInformation((HANDLE)_get_osfhandle(fd), HANDLE_FLAG_INHERIT, 0);
+#endif
+}
+
+
+int open_cloexec(const char *name, int flags)
+{
+  int fd = open(name, (flags | O_CLOEXEC));
+
+  if (fd >= 0) {
+    set_close_on_execute(fd);
+  }
+
+  return fd;
+}
+
+int create_cloexec(const char *name, int flags, mode_t mode)
+{
+  int fd = open(name, (flags | O_CREAT | O_CLOEXEC), mode);
+
+  if (fd >= 0) {
+    set_close_on_execute(fd);
+  }
+
+  return fd;
+}
+