Emulate pipe2() on systems without it.

lib/util/pipe2.c

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2017 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * 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.
+ */
+
+#include <config.h>
+
+#ifndef HAVE_PIPE2
+
+#include <sys/types.h>
+
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "sudo_compat.h"
+
+int
+sudo_pipe2(int fildes[2], int flags)
+{
+    if (pipe(fildes) != 0)
+	return -1;
+
+    if (ISSET(flags, O_NONBLOCK)) {
+	int flags = fcntl(fildes[0], F_GETFL, 0);
+	if (flags == -1)
+	    goto bad;
+	if (fcntl(fildes[0], F_SETFL, flags | O_NONBLOCK) == -1)
+	    goto bad;
+	flags = fcntl(fildes[1], F_GETFL, 0);
+	if (flags == -1)
+	    goto bad;
+	if (fcntl(fildes[1], F_SETFL, flags | O_NONBLOCK) == -1)
+	    goto bad;
+    }
+    if (ISSET(flags, O_CLOEXEC)) {
+	if (fcntl(fildes[0], F_SETFD, FD_CLOEXEC) == -1)
+	    goto bad;
+	if (fcntl(fildes[1], F_SETFD, FD_CLOEXEC) == -1)
+	    goto bad;
+    }
+    return 0;
+bad:
+    close(fildes[0]);
+    close(fildes[1]);
+    return -1;
+}
+
+#endif /* HAVE_PIPE2 */