--- /dev/null
+/*****************************************************************************
+ * fdopendir.c: POSIX fdopendir replacement
+ *****************************************************************************
+ * Copyright © 2011 Rémi Denis-Courmont
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdio.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <dirent.h>
+
+DIR *fdopendir (int fd)
+{
+#ifdef F_GETFL
+ /* Check read permission on file descriptor */
+ int mode = fcntl (fd, F_GETFL);
+ if (mode == -1 || (mode & O_ACCMODE) == O_WRONLY)
+ {
+ errno = EBADF;
+ return NULL;
+ }
+#endif
+ /* Check directory file type */
+ struct stat st;
+ if (fstat (fd, &st))
+ return NULL;
+
+ if (!S_ISDIR (st.st_mode))
+ {
+ errno = ENOTDIR;
+ return NULL;
+ }
+
+ /* Try to open the directory through /proc where available.
+ * Not all operating systems support this. Fix your libc! */
+ char path[sizeof ("/proc/self/fd/") + 3 * sizeof (int)];
+ sprintf (path, "/proc/self/fd/%u", fd);
+
+ DIR *dir = opendir (path);
+ if (dir != NULL)
+ {
+ close (fd);
+ return dir;
+ }
+
+ /* Hide impossible errors for fdopendir() */
+ switch (errno)
+ {
+ case EACCES:
+#ifdef ELOOP
+ case ELOOP:
+#endif
+ case ENAMETOOLONG:
+ case ENOENT:
+ case EMFILE:
+ case ENFILE:
+ errno = EIO;
+ }
+ return NULL;
+}
dnl Check for usual libc functions
AC_CHECK_DECLS([nanosleep],,,[#include <time.h>])
-AC_CHECK_FUNCS([daemon fcntl fdopendir fstatvfs fork getenv getpwuid_r if_nameindex if_nametoindex isatty lstat memalign mmap openat pread posix_fadvise posix_madvise posix_memalign setlocale stricmp strnicmp uselocale])
-AC_REPLACE_FUNCS([asprintf atof atoll dirfd flockfile fsync getdelim getpid gmtime_r lldiv localtime_r nrand48 rewind setenv strcasecmp strcasestr strdup strlcpy strncasecmp strndup strnlen strsep strtof strtok_r strtoll swab tdestroy vasprintf])
+AC_CHECK_FUNCS([daemon fcntl fstatvfs fork getenv getpwuid_r if_nameindex if_nametoindex isatty lstat memalign mmap openat pread posix_fadvise posix_madvise posix_memalign setlocale stricmp strnicmp uselocale])
+AC_REPLACE_FUNCS([asprintf atof atoll dirfd fdopendir flockfile fsync getdelim getpid gmtime_r lldiv localtime_r nrand48 rewind setenv strcasecmp strcasestr strdup strlcpy strncasecmp strndup strnlen strsep strtof strtok_r strtoll swab tdestroy vasprintf])
AC_CHECK_FUNCS(fdatasync,,
[AC_DEFINE(fdatasync, fsync, [Alias fdatasync() to fsync() if missing.])
])