utils: Check for dirfd(3)

Not all POSIX compatible systems might provide it yet.  If not, we close
the lowest FD to close and hope it gets reused by opendir().

diff --git a/configure.ac b/configure.ac
index 18132757cd04260d824f20e18ab3074740b9230e..545f1fb58623dade5a28a00dd88a78b75d6a4775 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -583,7 +583,7 @@ AC_CHECK_FUNC(
 )
 
 AC_CHECK_FUNCS(prctl mallinfo getpass closefrom getpwnam_r getgrnam_r getpwuid_r)
-AC_CHECK_FUNCS(fmemopen funopen mmap memrchr setlinebuf strptime)
+AC_CHECK_FUNCS(fmemopen funopen mmap memrchr setlinebuf strptime dirfd)
 
 AC_CHECK_FUNC([syslog], [
        AC_DEFINE([HAVE_SYSLOG], [], [have syslog(3) and friends])

diff --git a/src/libstrongswan/utils/utils.c b/src/libstrongswan/utils/utils.c
index c396540ec23f95a12bf40a8cbc36b10c2ea81a40..b4a4db802441b75bee4cf5eafd6e65dbb1ba0234 100644 (file)
--- a/src/libstrongswan/utils/utils.c
+++ b/src/libstrongswan/utils/utils.c
@@ -175,10 +175,19 @@ void closefrom(int low_fd)
        DIR *dir;
        struct dirent *entry;
 
+#ifndef HAVE_DIRFD
+       /* if we don't have dirfd() lets close the lowest FD and hope it gets reused
+        * by opendir() */
+       close(low_fd);
+       dir_fd = low_fd++;
+#endif
+
        dir = opendir(FD_DIR);
        if (dir)
        {
+#ifdef HAVE_DIRFD
                dir_fd = dirfd(dir);
+#endif
                while ((entry = readdir(dir)))
                {
                        if (!isdigit(entry->d_name[0]))