Only close open file descriptors on Linux.

diff --git a/src/libstrongswan/utils.c b/src/libstrongswan/utils.c
index eca613a5d061bca2cd776a7d62782301579008f3..7ad948f70b13dd2835d693fabbe50b9069b218c8 100644 (file)
--- a/src/libstrongswan/utils.c
+++ b/src/libstrongswan/utils.c
@@ -28,6 +28,7 @@
 
 #include "enum.h"
 #include "debug.h"
+#include "utils/enumerator.h"
 
 ENUM(status_names, SUCCESS, NEED_MORE,
        "SUCCESS",
@@ -199,7 +200,31 @@ bool mkdir_p(const char *path, mode_t mode)
  */
 void closefrom(int lowfd)
 {
-       int maxfd, fd;
+       char fd_dir[PATH_MAX];
+       int maxfd, fd, len;
+
+       /* try to close only open file descriptors on Linux... */
+       len = snprintf(fd_dir, sizeof(fd_dir), "/proc/%u/fd", getpid());
+       if (len > 0 && len < sizeof(fd_dir))
+       {
+               enumerator_t *enumerator = enumerator_create_directory(fd_dir);
+               if (enumerator)
+               {
+                       char *rel, *end;
+                       while (enumerator->enumerate(enumerator, &rel, NULL, NULL))
+                       {
+                               fd = atoi(rel);
+                               if (fd >= lowfd)
+                               {
+                                       close(fd);
+                               }
+                       }
+                       enumerator->destroy(enumerator);
+                       return;
+               }
+       }
+
+       /* ...fall back to closing all fds otherwise */
        maxfd = (int)sysconf(_SC_OPEN_MAX);
        if (maxfd < 0)
        {