From 8ffec2a3aba6f114784e11f89ef1d57a096ae540 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 19:39:29 +0200 Subject: Adding upstream version 8.32. Signed-off-by: Daniel Baumann --- lib/opendir-safer.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 lib/opendir-safer.c (limited to 'lib/opendir-safer.c') diff --git a/lib/opendir-safer.c b/lib/opendir-safer.c new file mode 100644 index 0000000..f718a95 --- /dev/null +++ b/lib/opendir-safer.c @@ -0,0 +1,76 @@ +/* Invoke opendir, but avoid some glitches. + + Copyright (C) 2009-2020 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 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 General Public License + along with this program. If not, see . */ + +/* Written by Eric Blake. */ + +#include + +#include "dirent-safer.h" + +#include +#include +#include + +/* Like opendir, but do not clobber stdin, stdout, or stderr. */ + +DIR * +opendir_safer (char const *name) +{ + DIR *dp = opendir (name); + + if (dp) + { + int fd = dirfd (dp); + + if (0 <= fd && fd <= STDERR_FILENO) + { + /* If fdopendir is native (as on Linux), then it is safe to + assume dirfd(fdopendir(n))==n. If we are using the + gnulib module fdopendir, then this guarantee is not met, + but fdopendir recursively calls opendir_safer up to 3 + times to at least get a safe fd. If fdopendir is not + present but dirfd is accurate (as on cygwin 1.5.x), then + we recurse up to 3 times ourselves. Finally, if dirfd + always fails (as on mingw), then we are already safe. */ + DIR *newdp; + int e; +#if HAVE_FDOPENDIR || GNULIB_FDOPENDIR + int f = fcntl (fd, F_DUPFD_CLOEXEC, STDERR_FILENO + 1); + if (f < 0) + { + e = errno; + newdp = NULL; + } + else + { + newdp = fdopendir (f); + e = errno; + if (! newdp) + close (f); + } +#else /* !FDOPENDIR */ + newdp = opendir_safer (name); + e = errno; +#endif + closedir (dp); + errno = e; + dp = newdp; + } + } + + return dp; +} -- cgit v1.2.3