root/sys/net/if_tun.h
/*      $NetBSD: if_tun.h,v 1.5 1994/06/29 06:36:27 cgd Exp $   */

/*-
 * Copyright (c) 1988, Julian Onions <jpo@cs.nott.ac.uk>
 * Nottingham University 1987.
 *
 * This source may be freely distributed, however I would be interested
 * in any changes that are made.
 *
 * This driver takes packets off the IP i/f and hands them up to a
 * user process to have its wicked way with. This driver has it's
 * roots in a similar driver written by Phil Cockcroft (formerly) at
 * UCL. This driver is based much more on read/write/select mode of
 * operation though.
 */

#ifndef _NET_IF_TUN_H_
#define _NET_IF_TUN_H_

/* Refer to if_tunvar.h for the softc stuff */

/* Maximum transmit packet size (default) */
#define TUNMTU          1500

/* Maximum receive packet size (hard limit) */
#define TUNMRU          65535

struct tuninfo {
        int     baudrate;               /* linespeed */
        unsigned short  mtu;            /* maximum transmission unit */
        u_char  type;                   /* ethernet, tokenring, etc. */
        u_char  dummy;                  /* place holder */
};

/* ioctl's for get/set debug */
#define TUNSDEBUG       _IOW('t', 90, int)
#define TUNGDEBUG       _IOR('t', 89, int)
#define TUNSIFINFO      _IOW('t', 91, struct tuninfo)
#define TUNGIFINFO      _IOR('t', 92, struct tuninfo)
#define TUNSLMODE       _IOW('t', 93, int)
#define TUNGIFNAME      _IOR('t', 93, struct ifreq)
#define TUNSIFMODE      _IOW('t', 94, int)
#define TUNSIFPID       _IO('t', 95)
#define TUNSIFHEAD      _IOW('t', 96, int)
#define TUNGIFHEAD      _IOR('t', 97, int)
#define TUNSTRANSIENT   _IOW('t', 98, int)
#define TUNGTRANSIENT   _IOR('t', 99, int)

#endif /* !_NET_IF_TUN_H_ */