1 files changed, 69 insertions, 0 deletions
diff --git a/lib/util/fchmodat.c b/lib/util/fchmodat.c
new file mode 100644
index 0000000..39d294e
--- /dev/null
+++ b/lib/util/fchmodat.c
@@ -0,0 +1,69 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2019-2020 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <sudo_compat.h>
+
+#ifndef HAVE_FCHMODAT
+int
+sudo_fchmodat(int dfd, const char *path, mode_t mode, int flag)
+{
+    int odfd, ret = -1;
+
+    if (ISSET(flag, AT_SYMLINK_NOFOLLOW)) {
+	errno = ENOTSUP;
+	return -1;
+    }
+
+    if (dfd == (int)AT_FDCWD)
+	return chmod(path, mode);
+
+    /* Save cwd */
+    if ((odfd = open(".", O_RDONLY)) == -1)
+	goto done;
+
+    if (fchdir(dfd) == -1)
+	goto done;
+
+    ret = chmod(path, mode);
+
+    /* Restore cwd */
+    if (fchdir(odfd) == -1) {
+	/* Should not happen */
+	ret = -1;
+    }
+
+done:
+    if (odfd != -1)
+	close(odfd);
+
+    return ret;
+}
+#endif /* HAVE_FCHMODAT */