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.

2 files changed, 46 insertions, 3 deletions

diff --git a/src/xine-utils/utils.c b/src/xine-utils/utils.c
index 75caaf09f..02a06aa24 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 {
   const char    language[16];     /* name of the locale */
   const char    encoding[16];     /* typical encoding */
@@ -717,3 +722,37 @@ 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;
+}
+
diff --git a/src/xine-utils/xine_check.c b/src/xine-utils/xine_check.c
index b0a252b6f..3c860493b 100644
--- a/src/xine-utils/xine_check.c
+++ b/src/xine-utils/xine_check.c
@@ -46,6 +46,10 @@
 
 #include <xine/xineutils.h>
 
+#ifndef O_CLOEXEC
+#  define O_CLOEXEC  0
+#endif
+
 #if defined(__linux__)
 
 #include <dlfcn.h>
@@ -168,7 +172,7 @@ static xine_health_check_t* _x_health_check_cdrom (xine_health_check_t* hc) {
     return hc;
   }
 
-  if ( (fd = open(hc->cdrom_dev, O_RDWR)) < 0) {
+  if ( (fd = open(hc->cdrom_dev, O_RDWR | O_CLOEXEC)) < 0) {
     switch (errno) {
     case EACCES:
       set_hc_result (hc, XINE_HEALTH_CHECK_FAIL, "FAILED - %s permissions are not sufficient\n.", hc->cdrom_dev);
@@ -204,7 +208,7 @@ static xine_health_check_t* _x_health_check_dvdrom(xine_health_check_t* hc) {
     return hc;
   }
 
-  if ( (fd = open(hc->dvd_dev, O_RDWR)) < 0) {
+  if ( (fd = open(hc->dvd_dev, O_RDWR | O_CLOEXEC)) < 0) {
     switch (errno) {
     case EACCES:
       set_hc_result (hc, XINE_HEALTH_CHECK_FAIL, "FAILED - %s permissions are not sufficient\n.", hc->dvd_dev);
@@ -247,7 +251,7 @@ static xine_health_check_t* _x_health_check_dma (xine_health_check_t* hc) {
     return hc;
   }
 
-  fd = open (hc->dvd_dev, O_RDONLY | O_NONBLOCK);
+  fd = open (hc->dvd_dev, O_RDONLY | O_NONBLOCK | O_CLOEXEC);
   if (fd < 0) {
     set_hc_result(hc, XINE_HEALTH_CHECK_FAIL, "FAILED - Could not open %s.\n", hc->dvd_dev);
     return hc;