Index: sys/sys/capsicum_helpers.h
===================================================================
--- /dev/null
+++ sys/sys/capsicum_helpers.h
@@ -0,0 +1,125 @@
+/*-
+ * Copyright (c) 2016 Mariusz Zaborski <oshogbo@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _CAPSICUM_HELPERS_H_
+#define	_CAPSICUM_HELPERS_H_
+
+#include <sys/param.h>
+#include <sys/capsicum.h>
+
+#include <errno.h>
+#include <nl_types.h>
+#include <termios.h>
+#include <time.h>
+#include <unistd.h>
+
+#define	CAPH_IGNORE_EBADF	0x0001
+
+static inline int
+caph_limit_fd(int fd, int flags)
+{
+	int mode;
+	cap_rights_t rights;
+	unsigned long cmds[] = { TIOCGETA, TIOCGWINSZ };
+
+	mode = fcntl(fd, F_GETFL);
+	if (flags < 0) {
+		if (errno == EBADF && (flags & CAPH_IGNORE_EBADF) != 0)
+			return (0);
+		return (-1);
+	}
+
+	cap_rights_init(&rights, CAP_FSTAT, CAP_FCNTL, CAP_IOCTL, CAP_WRITE,
+	    CAP_READ);
+
+	if ((mode & O_ACCMODE) == O_WRONLY)
+		cap_rights_clear(&rights, CAP_READ);
+	else if ((mode & O_ACCMODE) == O_RDONLY)
+		cap_rights_clear(&rights, CAP_WRITE);
+
+	if (cap_rights_limit(fd, &rights) < 0 && errno != ENOSYS)
+		return (-1);
+
+	if (cap_ioctls_limit(fd, cmds, nitems(cmds)) < 0 && errno != ENOSYS)
+		return (-1);
+
+	if (cap_fcntls_limit(fd, CAP_FCNTL_GETFL) < 0 && errno != ENOSYS)
+		return (-1);
+
+	errno = EBADF;
+	return (-1);
+}
+
+static inline int
+caph_limit_stdin(void)
+{
+
+	return (caph_limit_fd(STDIN_FILENO, 0));
+}
+
+static inline int
+caph_limit_stderr(void)
+{
+
+	return (caph_limit_fd(STDERR_FILENO, 0));
+}
+
+static inline int
+caph_limit_stdout(void)
+{
+
+	return (caph_limit_fd(STDOUT_FILENO, 0));
+}
+
+static inline int
+caph_limit_stdio(void)
+{
+
+	if (caph_limit_stdin() == -1 || caph_limit_stdout() == -1 ||
+	    caph_limit_stdout() == -1) {
+		return (-1);
+	}
+
+	return (0);
+}
+
+static inline void
+caph_cache_tzdata(void)
+{
+
+	tzset();
+}
+
+static inline void
+caph_cache_catpages(void)
+{
+
+	(void)catopen("libc", NL_CAT_LOCALE);
+}
+
+#endif /* _CAPSICUM_HELPERS_H_ */