[apple/xnu.git] / bsd / net / if_tun.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*	$NetBSD: if_tun.c,v 1.14 1994/06/29 06:36:25 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/poll mode of
 * operation though.
 */

#include "tun.h"
#if NTUN > 0

#include "opt_devfs.h"
#include "opt_inet.h"

#include <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/filio.h>
#include <sys/sockio.h>
#include <sys/ttycom.h>
#include <sys/poll.h>
#include <sys/signalvar.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#if DEVFS
#include <sys/devfsext.h>
#endif /*DEVFS*/
#include <sys/conf.h>
#include <sys/uio.h>
#include <sys/vnode.h>

#include <net/if.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/route.h>

#if INET
#include <netinet/in.h>
#include <netinet/in_var.h>
#endif

#if INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_ifattach.h>
#endif /* INET6 */

#if NS
#include <netns/ns.h>
#include <netns/ns_if.h>
#endif

#include "bpfilter.h"
#if NBPFILTER > 0
#include <net/bpf.h>
#endif

#include <net/if_tunvar.h>
#include <net/if_tun.h>

static void tunattach __P((void *));
PSEUDO_SET(tunattach, if_tun);

#define TUNDEBUG	if (tundebug) printf
static int tundebug = 0;
SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");

static struct tun_softc tunctl[NTUN];

static int tunoutput __P((struct ifnet *, struct mbuf *, struct sockaddr *,
	    struct rtentry *rt));
static int tunifioctl __P((struct ifnet *, u_long, caddr_t));
static int tuninit __P((int, int, u_char));

static	d_open_t	tunopen;
static	d_close_t	tunclose;
static	d_read_t	tunread;
static	d_write_t	tunwrite;
static	d_ioctl_t	tunioctl;
static	d_poll_t	tunpoll;

#define CDEV_MAJOR 52
static struct cdevsw tun_cdevsw = {
	tunopen,	tunclose,	tunread,	tunwrite,
	tunioctl,	nullstop,	noreset,	nodevtotty,
	tunpoll,	nommap,		nostrategy,	"tun",	NULL,	-1
};


static	int	tun_devsw_installed;
#if	DEVFS
static	void	*tun_devfs_token[NTUN];
#endif

#define minor_val(n) ((((n) & ~0xff) << 8) | ((n) & 0xff))
#define dev_val(n) (((n) >> 8) | ((n) & 0xff))

static void
tunattach(dummy)
	void *dummy;
{
	register int i;
	struct ifnet *ifp;
	dev_t dev;

	if ( tun_devsw_installed )
		return;
	dev = makedev(CDEV_MAJOR, 0);
	cdevsw_add(&dev, &tun_cdevsw, NULL);
	tun_devsw_installed = 1;
	for ( i = 0; i < NTUN; i++ ) {
#if DEVFS
		tun_devfs_token[i] = devfs_add_devswf(&tun_cdevsw, minor_val(i),
						      DV_CHR, UID_UUCP,
						      GID_DIALER, 0600,
						      "tun%d", i);
#endif
		tunctl[i].tun_flags = TUN_INITED;

		ifp = &tunctl[i].tun_if;
		ifp->if_unit = i;
		ifp->if_name = "tun";
		ifp->if_family = APPLE_IF_FAM_TUN;
		ifp->if_mtu = TUNMTU;
		ifp->if_ioctl = tunifioctl;
		ifp->if_output = tunoutput;
		ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
		ifp->if_type = IFT_PPP; /* necessary init value for IPv6 lladdr auto conf */
		ifp->if_snd.ifq_maxlen = ifqmaxlen;
		if_attach(ifp);
#if NBPFILTER > 0
		bpfattach(ifp, DLT_NULL, sizeof(u_int));
#endif
	}
}

/*
 * tunnel open - must be superuser & the device must be
 * configured in
 */
static	int
tunopen(dev, flag, mode, p)
	dev_t	dev;
	int	flag, mode;
	struct proc *p;
{
	struct ifnet	*ifp;
	struct tun_softc *tp;
	register int	unit, error;

	error = suser(p->p_ucred, &p->p_acflag);
	if (error)
		return (error);

	if ((unit = dev_val(minor(dev))) >= NTUN)
		return (ENXIO);
	tp = &tunctl[unit];
	if (tp->tun_flags & TUN_OPEN)
		return EBUSY;
	ifp = &tp->tun_if;
	tp->tun_flags |= TUN_OPEN;
	TUNDEBUG("%s%d: open\n", ifp->if_name, ifp->if_unit);
	return (0);
}

/*
 * tunclose - close the device - mark i/f down & delete
 * routing info
 */
static	int
tunclose(dev, foo, bar, p)
	dev_t dev;
	int foo;
	int bar;
	struct proc *p;
{
	register int	unit = dev_val(minor(dev)), s;
	struct tun_softc *tp = &tunctl[unit];
	struct ifnet	*ifp = &tp->tun_if;
	struct mbuf	*m;

	tp->tun_flags &= ~TUN_OPEN;

	/*
	 * junk all pending output
	 */
	do {
		s = splimp();
		IF_DEQUEUE(&ifp->if_snd, m);
		splx(s);
		if (m)
			m_freem(m);
	} while (m);

	if (ifp->if_flags & IFF_UP) {
		s = splimp();
		if_down(ifp);
		if (ifp->if_flags & IFF_RUNNING) {
		    /* find internet addresses and delete routes */
		    register struct ifaddr *ifa;
		    for (ifa = ifp->if_addrhead.tqh_first; ifa;
			 ifa = ifa->ifa_link.tqe_next) {
			switch (ifa->ifa_addr->sa_family) {
#if INET
			case AF_INET:
#endif
#if INET6
			case AF_INET6:
#endif
			    rtinit(ifa, (int)RTM_DELETE,
				   tp->tun_flags & TUN_DSTADDR ? RTF_HOST : 0);
			    break;
			}
		    }
		}
		splx(s);
	}
	ifp->if_flags &= ~IFF_RUNNING;
	funsetown(tp->tun_sigio);
	selwakeup(&tp->tun_rsel);
	selthreadclear(&tp->tun_rsel);

	TUNDEBUG ("%s%d: closed\n", ifp->if_name, ifp->if_unit);
	return (0);
}

static int
tuninit(unit, cmd, af)
	int	unit;
	int	cmd;
	u_char	af;
{
	struct tun_softc *tp = &tunctl[unit];
	struct ifnet	*ifp = &tp->tun_if;
	register struct ifaddr *ifa;

	TUNDEBUG("%s%d: tuninit\n", ifp->if_name, ifp->if_unit);

	ifp->if_flags |= IFF_UP | IFF_RUNNING;
	getmicrotime(&ifp->if_lastchange);

	for (ifa = ifp->if_addrhead.tqh_first; ifa; 
	     ifa = ifa->ifa_link.tqe_next) {
#if INET
		if (ifa->ifa_addr->sa_family == AF_INET) {
		    struct sockaddr_in *si;

		    si = (struct sockaddr_in *)ifa->ifa_addr;
		    if (si && si->sin_addr.s_addr)
			    tp->tun_flags |= TUN_IASET;

		    si = (struct sockaddr_in *)ifa->ifa_dstaddr;
		    if (si && si->sin_addr.s_addr)
			    tp->tun_flags |= TUN_DSTADDR;
		}
#endif
	}
	return 0;
}

/*
 * Process an ioctl request.
 */
int
tunifioctl(ifp, cmd, data)
	struct ifnet *ifp;
	u_long	cmd;
	caddr_t	data;
{
	register struct ifreq *ifr = (struct ifreq *)data;
	int		error = 0, s;

	s = splimp();
	switch(cmd) {
	case SIOCSIFADDR:
		tuninit(ifp->if_unit);
		TUNDEBUG("%s%d: address set\n",
			 ifp->if_name, ifp->if_unit);
		break;
	case SIOCSIFDSTADDR:
#if 0
#if defined(INET6) && defined(__FreeBSD__) && __FreeBSD__ >= 3
		if (found_first_ifid == 0)
			in6_ifattach_noifid(ifp);
#endif /* defined(INET6) && defined(__FreeBSD__) && __FreeBSD__ >= 3 */
#endif
		tuninit(ifp->if_unit, cmd, ifr->ifr_addr.sa_family);
		break;
	case SIOCSIFMTU:
		ifp->if_mtu = ifr->ifr_mtu;
		TUNDEBUG("%s%d: mtu set\n",
			 ifp->if_name, ifp->if_unit);
		break;
	case SIOCADDMULTI:
	case SIOCDELMULTI:
		break;

	case SIOCSIFFLAGS:
		if ((ifp->if_flags & IFF_UP) != 0)
			ifp->if_flags |= IFF_RUNNING;
		else if ((ifp->if_flags & IFF_UP) == 0)
			ifp->if_flags &= ~IFF_RUNNING;
		break;

	default:
		error = EINVAL;
	}
	splx(s);
	return (error);
}

/*
 * tunoutput - queue packets from higher level ready to put out.
 */
/* Packet data format between tun and ppp is changed to enable checking of
 * Address Family of sending packet. When INET6 is defined, 4byte AF field
 * is appended to packet data as following.
 *
 *        0  1  2  3  4  5  6  7  8 .....
 *       ------------------------------
 *       |    af     |  packet data .....
 *       ------------------------------
 *       ^^^^^^^^^^^^^
 *       Newly added part. The size is sizeof(u_long).
 *
 * However, this is not adopted for tun -> ppp AF_INET packet for 
 * backword compatibility, because the ppp process may be an existing
 * ip only supporting one.  
 * Also in ppp->tun case, when af value is unknown, (af > 255) is checked and
 * if it is true, AF_INET is assumed. (the 4byte may be the head of
 * AF_INET packet. Despite the byte order, the value must always be
 * greater than 255, because of ip_len field or (ip_v and ip_hl)
 * field. (Idea from Mr. Noritoshi Demize)
 */
int
tunoutput(ifp, m0, dst, rt)
	struct ifnet   *ifp;
	struct mbuf    *m0;
	struct sockaddr *dst;
	struct rtentry *rt;
{
	struct tun_softc *tp = &tunctl[ifp->if_unit];
	int		s;

	TUNDEBUG ("%s%d: tunoutput\n", ifp->if_name, ifp->if_unit);

	if ((tp->tun_flags & TUN_READY) != TUN_READY) {
		TUNDEBUG ("%s%d: not ready 0%o\n", ifp->if_name,
			  ifp->if_unit, tp->tun_flags);
		m_freem (m0);
		return EHOSTDOWN;
	}

#if NBPFILTER > 0
	/* BPF write needs to be handled specially */
	if (dst->sa_family == AF_UNSPEC) {
		dst->sa_family = *(mtod(m0, int *));
		m0->m_len -= sizeof(int);
		m0->m_pkthdr.len -= sizeof(int);
		m0->m_data += sizeof(int);
	}

	if (ifp->if_bpf) {
		/*
		 * We need to prepend the address family as
		 * a four byte field.  Cons up a dummy header
		 * to pacify bpf.  This is safe because bpf
		 * will only read from the mbuf (i.e., it won't
		 * try to free it or keep a pointer to it).
		 */
		struct mbuf m;
		u_int af = dst->sa_family;

		m.m_next = m0;
		m.m_len = 4;
		m.m_data = (char *)&af;

		bpf_mtap(ifp, &m);
	}
#endif

	switch(dst->sa_family) {
#if defined(INET) || defined(INET6)
#if INET6
	case AF_INET6:
		M_PREPEND(m0, sizeof(u_long) /* af field passed to upper */,
			  M_DONTWAIT);
		if (m0 == 0)
			return (ENOBUFS);
		*mtod(m0, u_long *) = (u_long)dst->sa_family;
		/* FALLTHROUGH */
#endif /* INET6 */
#if INET
	case AF_INET:
#endif /* INET */
#endif /* INET || INET6 */
		s = splimp();
		if (IF_QFULL(&ifp->if_snd)) {
			IF_DROP(&ifp->if_snd);
			m_freem(m0);
			splx(s);
			ifp->if_collisions++;
			return (ENOBUFS);
		}
		ifp->if_obytes += m0->m_pkthdr.len;
		IF_ENQUEUE(&ifp->if_snd, m0);
		splx(s);
		ifp->if_opackets++;
		break;
	default:
		m_freem(m0);
		return EAFNOSUPPORT;
	}

	if (tp->tun_flags & TUN_RWAIT) {
		tp->tun_flags &= ~TUN_RWAIT;
		wakeup((caddr_t)tp);
	}
	if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio)
		pgsigio(tp->tun_sigio, SIGIO, 0);
	selwakeup(&tp->tun_rsel);
	return 0;
}

/*
 * the cdevsw interface is now pretty minimal.
 */
static	int
tunioctl(dev, cmd, data, flag, p)
	dev_t		dev;
	u_long		cmd;
	caddr_t		data;
	int		flag;
	struct proc	*p;
{
	int		unit = dev_val(minor(dev)), s;
	struct tun_softc *tp = &tunctl[unit];
 	struct tuninfo *tunp;

	switch (cmd) {
 	case TUNSIFINFO:
 	        tunp = (struct tuninfo *)data;
 		tp->tun_if.if_mtu = tunp->mtu;
 		tp->tun_if.if_type = tunp->type;
 		tp->tun_if.if_baudrate = tunp->baudrate;
 		break;
 	case TUNGIFINFO:
 		tunp = (struct tuninfo *)data;
 		tunp->mtu = tp->tun_if.if_mtu;
 		tunp->type = tp->tun_if.if_type;
 		tunp->baudrate = tp->tun_if.if_baudrate;
 		break;
	case TUNSDEBUG:
		tundebug = *(int *)data;
		break;
	case TUNGDEBUG:
		*(int *)data = tundebug;
		break;
	case FIONBIO:
		break;
	case FIOASYNC:
		if (*(int *)data)
			tp->tun_flags |= TUN_ASYNC;
		else
			tp->tun_flags &= ~TUN_ASYNC;
		break;
	case FIONREAD:
		s = splimp();
		if (tp->tun_if.if_snd.ifq_head) {
			struct mbuf *mb = tp->tun_if.if_snd.ifq_head;
			for( *(int *)data = 0; mb != 0; mb = mb->m_next) 
				*(int *)data += mb->m_len;
		} else
			*(int *)data = 0;
		splx(s);
		break;
	case FIOSETOWN:
		return (fsetown(*(int *)data, &tp->tun_sigio));

	case FIOGETOWN:
		*(int *)data = fgetown(tp->tun_sigio);
		return (0);

	/* This is deprecated, FIOSETOWN should be used instead. */
	case TIOCSPGRP:
		return (fsetown(-(*(int *)data), &tp->tun_sigio));

	/* This is deprecated, FIOGETOWN should be used instead. */
	case TIOCGPGRP:
		*(int *)data = -fgetown(tp->tun_sigio);
		return (0);

	default:
		return (ENOTTY);
	}
	return (0);
}

/*
 * The cdevsw read interface - reads a packet at a time, or at
 * least as much of a packet as can be read.
 */
static	int
tunread(dev, uio, flag)
	dev_t dev;
	struct uio *uio;
	int flag;
{
	int		unit = dev_val(minor(dev));
	struct tun_softc *tp = &tunctl[unit];
	struct ifnet	*ifp = &tp->tun_if;
	struct mbuf	*m, *m0;
	int		error=0, len, s;

	TUNDEBUG ("%s%d: read\n", ifp->if_name, ifp->if_unit);
	if ((tp->tun_flags & TUN_READY) != TUN_READY) {
		TUNDEBUG ("%s%d: not ready 0%o\n", ifp->if_name,
			  ifp->if_unit, tp->tun_flags);
		return EHOSTDOWN;
	}

	tp->tun_flags &= ~TUN_RWAIT;

	s = splimp();
	do {
		IF_DEQUEUE(&ifp->if_snd, m0);
		if (m0 == 0) {
			if (flag & IO_NDELAY) {
				splx(s);
				return EWOULDBLOCK;
			}
			tp->tun_flags |= TUN_RWAIT;
			if( error = tsleep((caddr_t)tp, PCATCH | (PZERO + 1),
					"tunread", 0)) {
				splx(s);
				return error;
			}
		}
	} while (m0 == 0);
	splx(s);

	while (m0 && uio->uio_resid > 0 && error == 0) {
		len = min(uio->uio_resid, m0->m_len);
		if (len == 0)
			break;
		error = uiomove(mtod(m0, caddr_t), len, uio);
		MFREE(m0, m);
		m0 = m;
	}

	if (m0) {
		TUNDEBUG("Dropping mbuf\n");
		m_freem(m0);
	}
	return error;
}

/*
 * the cdevsw write interface - an atomic write is a packet - or else!
 */
/* See top of tunoutput() about interface change between ppp process and 
 * tun. */
static	int
tunwrite(dev, uio, flag)
	dev_t dev;
	struct uio *uio;
	int flag;
{
	int		unit = dev_val(minor(dev));
	struct ifnet	*ifp = &tunctl[unit].tun_if;
	struct mbuf	*top, **mp, *m;
	int		error=0, s, tlen, mlen;
	u_long af;
	u_int netisr_af;
	struct ifqueue *afintrq = NULL;

	TUNDEBUG("%s%d: tunwrite\n", ifp->if_name, ifp->if_unit);

	if (uio->uio_resid < 0 || uio->uio_resid > TUNMRU) {
		TUNDEBUG("%s%d: len=%d!\n", ifp->if_name, ifp->if_unit,
		    uio->uio_resid);
		return EIO;
	}
	tlen = uio->uio_resid;

	/* get a header mbuf */
	MGETHDR(m, M_DONTWAIT, MT_DATA);
	if (m == NULL)
		return ENOBUFS;
	if (tlen > MHLEN) {
	  MCLGET(m, M_DONTWAIT);
	  if ((m->m_flags & M_EXT) == 0) {
	    m_free(m);
	    return ENOBUFS;
	  }
	  mlen = m->m_ext.ext_size;
	} else
	  mlen = MHLEN;

	top = 0;
	mp = &top;
	while (error == 0 && uio->uio_resid > 0) {
		m->m_len = min(mlen, uio->uio_resid);
		error = uiomove(mtod (m, caddr_t), m->m_len, uio);
		*mp = m;
		mp = &m->m_next;
		if (uio->uio_resid > 0) {
			MGET (m, M_DONTWAIT, MT_DATA);
			if (m == 0) {
				error = ENOBUFS;
				break;
			}
			mlen = MLEN;
		}
	}
	/* Change for checking Address Family of sending packet. */
	af = *mtod(top, u_long *);
	switch (af) {
#if INET
	case AF_INET:
		netisr_af = NETISR_IP;
		afintrq = &ipintrq;
		break;
#endif /* INET */
#if INET6
	case AF_INET6:
		netisr_af = NETISR_IPV6;
		afintrq = &ip6intrq;
		break;
#endif /* INET6 */
	default:
		if (af > 255) { /* see description at the top of tunoutput */
			af = AF_INET;
			netisr_af = NETISR_IP;
			afintrq = &ipintrq;
			goto af_decided;
		}
		error = EAFNOSUPPORT;
		break;
	}
	m_adj(top, sizeof(u_long)); /* remove af field passed from upper */
	tlen -= sizeof(u_long);
      af_decided:
	if (error) {
		if (top)
			m_freem (top);
		return error;
	}

	top->m_pkthdr.len = tlen;
	top->m_pkthdr.rcvif = ifp;

#if NBPFILTER > 0
	if (ifp->if_bpf) {
		/*
		 * We need to prepend the address family as
		 * a four byte field.  Cons up a dummy header
		 * to pacify bpf.  This is safe because bpf
		 * will only read from the mbuf (i.e., it won't
		 * try to free it or keep a pointer to it).
		 */
		struct mbuf m;

		m.m_next = top;
		m.m_len = 4;
		m.m_data = (char *)&af;

		bpf_mtap(ifp, &m);
	}
#endif

	/* just for safety */
	if (!afintrq)
		return EAFNOSUPPORT;

	s = splimp();
	if (IF_QFULL (afintrq)) {
		IF_DROP(afintrq);
		splx(s);
		ifp->if_collisions++;
		m_freem(top);
		return ENOBUFS;
	}
	IF_ENQUEUE(afintrq, top);
	splx(s);
	ifp->if_ibytes += tlen;
	ifp->if_ipackets++;
	schednetisr(netisr_af);
	return error;
}

/*
 * tunpoll - the poll interface, this is only useful on reads
 * really. The write detect always returns true, write never blocks
 * anyway, it either accepts the packet or drops it.
 */
static	int
tunpoll(dev, events, wql, p)
	dev_t dev;
	int events;
	void * wql;
	struct proc *p;
{
	int		unit = dev_val(minor(dev)), s;
	struct tun_softc *tp = &tunctl[unit];
	struct ifnet	*ifp = &tp->tun_if;
	int		revents = 0;

	s = splimp();
	TUNDEBUG("%s%d: tunpoll\n", ifp->if_name, ifp->if_unit);

	if (events & (POLLIN | POLLRDNORM))
		if (ifp->if_snd.ifq_len > 0) {
			TUNDEBUG("%s%d: tunpoll q=%d\n", ifp->if_name,
			    ifp->if_unit, ifp->if_snd.ifq_len);
			revents |= events & (POLLIN | POLLRDNORM);
		} else {
			TUNDEBUG("%s%d: tunpoll waiting\n", ifp->if_name,
			    ifp->if_unit);
			selrecord(p, &tp->tun_rsel, wql);
		}

	if (events & (POLLOUT | POLLWRNORM))
		revents |= events & (POLLOUT | POLLWRNORM);

	splx(s);
	return (revents);
}


#endif  /* NTUN */
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
	11	*
	12	* This Original Code and all software distributed under the License are
	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/* $NetBSD: if_tun.c,v 1.14 1994/06/29 06:36:25 cgd Exp $ */
	23
	24	/*
	25	* Copyright (c) 1988, Julian Onions <jpo@cs.nott.ac.uk>
	26	* Nottingham University 1987.
	27	*
	28	* This source may be freely distributed, however I would be interested
	29	* in any changes that are made.
	30	*
	31	* This driver takes packets off the IP i/f and hands them up to a
	32	* user process to have its wicked way with. This driver has it's
	33	* roots in a similar driver written by Phil Cockcroft (formerly) at
	34	* UCL. This driver is based much more on read/write/poll mode of
	35	* operation though.
	36	*/
	37
	38	#include "tun.h"
	39	#if NTUN > 0
	40
	41	#include "opt_devfs.h"
	42	#include "opt_inet.h"
	43
	44	#include <sys/param.h>
	45	#include <sys/proc.h>
	46	#include <sys/systm.h>
	47	#include <sys/mbuf.h>
	48	#include <sys/socket.h>
	49	#include <sys/filio.h>
	50	#include <sys/sockio.h>
	51	#include <sys/ttycom.h>
	52	#include <sys/poll.h>
	53	#include <sys/signalvar.h>
	54	#include <sys/filedesc.h>
	55	#include <sys/kernel.h>
	56	#include <sys/sysctl.h>
	57	#if DEVFS
	58	#include <sys/devfsext.h>
	59	#endif /DEVFS/
	60	#include <sys/conf.h>
	61	#include <sys/uio.h>
	62	#include <sys/vnode.h>
	63
	64	#include <net/if.h>
65	#include <net/if_types.h>
66	#include <net/netisr.h>
67	#include <net/route.h>
68
69	#if INET
70	#include <netinet/in.h>
71	#include <netinet/in_var.h>
72	#endif
73
74	#if INET6
75	#include <netinet/ip6.h>
76	#include <netinet6/ip6_var.h>
77	#include <netinet6/in6_ifattach.h>
78	#endif /* INET6 */
79
80	#if NS
81	#include <netns/ns.h>
82	#include <netns/ns_if.h>
83	#endif
84
85	#include "bpfilter.h"
86	#if NBPFILTER > 0
87	#include <net/bpf.h>
88	#endif
89
90	#include <net/if_tunvar.h>
91	#include <net/if_tun.h>
92
93	static void tunattach __P((void *));
94	PSEUDO_SET(tunattach, if_tun);
95
96	#define TUNDEBUG if (tundebug) printf
97	static int tundebug = 0;
98	SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");
99
100	static struct tun_softc tunctl[NTUN];
101
102	static int tunoutput __P((struct ifnet , struct mbuf , struct sockaddr *,
103	struct rtentry *rt));
104	static int tunifioctl __P((struct ifnet *, u_long, caddr_t));
105	static int tuninit __P((int, int, u_char));
106
107	static d_open_t tunopen;
108	static d_close_t tunclose;
109	static d_read_t tunread;
110	static d_write_t tunwrite;
111	static d_ioctl_t tunioctl;
112	static d_poll_t tunpoll;
113
114	#define CDEV_MAJOR 52
115	static struct cdevsw tun_cdevsw = {
116	tunopen, tunclose, tunread, tunwrite,
117	tunioctl, nullstop, noreset, nodevtotty,
118	tunpoll, nommap, nostrategy, "tun", NULL, -1
119	};
120
121
122	static int tun_devsw_installed;
123	#if DEVFS
124	static void *tun_devfs_token[NTUN];
125	#endif
126
127	#define minor_val(n) ((((n) & ~0xff) << 8) \| ((n) & 0xff))
128	#define dev_val(n) (((n) >> 8) \| ((n) & 0xff))
129
130	static void
131	tunattach(dummy)
132	void *dummy;
133	{
134	register int i;
135	struct ifnet *ifp;
136	dev_t dev;
137
138	if ( tun_devsw_installed )
139	return;
140	dev = makedev(CDEV_MAJOR, 0);
141	cdevsw_add(&dev, &tun_cdevsw, NULL);
142	tun_devsw_installed = 1;
143	for ( i = 0; i < NTUN; i++ ) {
144	#if DEVFS
145	tun_devfs_token[i] = devfs_add_devswf(&tun_cdevsw, minor_val(i),
146	DV_CHR, UID_UUCP,
147	GID_DIALER, 0600,
148	"tun%d", i);
149	#endif
150	tunctl[i].tun_flags = TUN_INITED;
151
152	ifp = &tunctl[i].tun_if;
153	ifp->if_unit = i;
154	ifp->if_name = "tun";
155	ifp->if_family = APPLE_IF_FAM_TUN;
156	ifp->if_mtu = TUNMTU;
157	ifp->if_ioctl = tunifioctl;
158	ifp->if_output = tunoutput;
159	ifp->if_flags = IFF_POINTOPOINT \| IFF_MULTICAST;
160	ifp->if_type = IFT_PPP; /* necessary init value for IPv6 lladdr auto conf */
161	ifp->if_snd.ifq_maxlen = ifqmaxlen;
162	if_attach(ifp);
163	#if NBPFILTER > 0
164	bpfattach(ifp, DLT_NULL, sizeof(u_int));
165	#endif
166	}
167	}
168
169	/*
170	* tunnel open - must be superuser & the device must be
171	* configured in
172	*/
173	static int
174	tunopen(dev, flag, mode, p)
175	dev_t dev;
176	int flag, mode;
177	struct proc *p;
178	{
179	struct ifnet *ifp;
180	struct tun_softc *tp;
181	register int unit, error;
182
183	error = suser(p->p_ucred, &p->p_acflag);
184	if (error)
185	return (error);
186
187	if ((unit = dev_val(minor(dev))) >= NTUN)
188	return (ENXIO);
189	tp = &tunctl[unit];
190	if (tp->tun_flags & TUN_OPEN)
191	return EBUSY;
192	ifp = &tp->tun_if;
193	tp->tun_flags \|= TUN_OPEN;
194	TUNDEBUG("%s%d: open\n", ifp->if_name, ifp->if_unit);
195	return (0);
196	}
197
198	/*
199	* tunclose - close the device - mark i/f down & delete
200	* routing info
201	*/
202	static int
203	tunclose(dev, foo, bar, p)
204	dev_t dev;
205	int foo;
206	int bar;
207	struct proc *p;
208	{
209	register int unit = dev_val(minor(dev)), s;
210	struct tun_softc *tp = &tunctl[unit];
211	struct ifnet *ifp = &tp->tun_if;
212	struct mbuf *m;
213
214	tp->tun_flags &= ~TUN_OPEN;
215
216	/*
217	* junk all pending output
218	*/
219	do {
220	s = splimp();
221	IF_DEQUEUE(&ifp->if_snd, m);
222	splx(s);
223	if (m)
224	m_freem(m);
225	} while (m);
226
227	if (ifp->if_flags & IFF_UP) {
228	s = splimp();
229	if_down(ifp);
230	if (ifp->if_flags & IFF_RUNNING) {
231	/* find internet addresses and delete routes */
232	register struct ifaddr *ifa;
233	for (ifa = ifp->if_addrhead.tqh_first; ifa;
234	ifa = ifa->ifa_link.tqe_next) {
235	switch (ifa->ifa_addr->sa_family) {
236	#if INET
237	case AF_INET:
238	#endif
239	#if INET6
240	case AF_INET6:
241	#endif
242	rtinit(ifa, (int)RTM_DELETE,
243	tp->tun_flags & TUN_DSTADDR ? RTF_HOST : 0);
244	break;
245	}
246	}
247	}
248	splx(s);
249	}
250	ifp->if_flags &= ~IFF_RUNNING;
251	funsetown(tp->tun_sigio);
1c79356b	252	selwakeup(&tp->tun_rsel);
0b4e3aa0	253	selthreadclear(&tp->tun_rsel);
1c79356b A	254
	255	TUNDEBUG ("%s%d: closed\n", ifp->if_name, ifp->if_unit);
	256	return (0);
	257	}
	258
	259	static int
	260	tuninit(unit, cmd, af)
	261	int unit;
	262	int cmd;
	263	u_char af;
	264	{
	265	struct tun_softc *tp = &tunctl[unit];
	266	struct ifnet *ifp = &tp->tun_if;
	267	register struct ifaddr *ifa;
	268
	269	TUNDEBUG("%s%d: tuninit\n", ifp->if_name, ifp->if_unit);
	270
	271	ifp->if_flags \|= IFF_UP \| IFF_RUNNING;
	272	getmicrotime(&ifp->if_lastchange);
	273
	274	for (ifa = ifp->if_addrhead.tqh_first; ifa;
	275	ifa = ifa->ifa_link.tqe_next) {
	276	#if INET
	277	if (ifa->ifa_addr->sa_family == AF_INET) {
	278	struct sockaddr_in *si;
	279
	280	si = (struct sockaddr_in *)ifa->ifa_addr;
	281	if (si && si->sin_addr.s_addr)
	282	tp->tun_flags \|= TUN_IASET;
	283
	284	si = (struct sockaddr_in *)ifa->ifa_dstaddr;
	285	if (si && si->sin_addr.s_addr)
	286	tp->tun_flags \|= TUN_DSTADDR;
	287	}
	288	#endif
	289	}
	290	return 0;
	291	}
	292
	293	/*
	294	* Process an ioctl request.
	295	*/
	296	int
	297	tunifioctl(ifp, cmd, data)
	298	struct ifnet *ifp;
	299	u_long cmd;
	300	caddr_t data;
	301	{
	302	register struct ifreq ifr = (struct ifreq )data;
	303	int error = 0, s;
	304
	305	s = splimp();
	306	switch(cmd) {
	307	case SIOCSIFADDR:
	308	tuninit(ifp->if_unit);
	309	TUNDEBUG("%s%d: address set\n",
	310	ifp->if_name, ifp->if_unit);
	311	break;
	312	case SIOCSIFDSTADDR:
	313	#if 0
	314	#if defined(INET6) && defined(__FreeBSD__) && __FreeBSD__ >= 3
	315	if (found_first_ifid == 0)
	316	in6_ifattach_noifid(ifp);
	317	#endif /* defined(INET6) && defined(__FreeBSD__) && __FreeBSD__ >= 3 */
318	#endif
319	tuninit(ifp->if_unit, cmd, ifr->ifr_addr.sa_family);
320	break;
321	case SIOCSIFMTU:
322	ifp->if_mtu = ifr->ifr_mtu;
323	TUNDEBUG("%s%d: mtu set\n",
324	ifp->if_name, ifp->if_unit);
325	break;
326	case SIOCADDMULTI:
327	case SIOCDELMULTI:
328	break;
329
330	case SIOCSIFFLAGS:
331	if ((ifp->if_flags & IFF_UP) != 0)
332	ifp->if_flags \|= IFF_RUNNING;
333	else if ((ifp->if_flags & IFF_UP) == 0)
334	ifp->if_flags &= ~IFF_RUNNING;
335	break;
336
337	default:
338	error = EINVAL;
339	}
340	splx(s);
341	return (error);
342	}
343
344	/*
345	* tunoutput - queue packets from higher level ready to put out.
346	*/
347	/* Packet data format between tun and ppp is changed to enable checking of
348	* Address Family of sending packet. When INET6 is defined, 4byte AF field
349	* is appended to packet data as following.
350	*
351	* 0 1 2 3 4 5 6 7 8 .....
352	* ------------------------------
353	* \| af \| packet data .....
354	* ------------------------------
355	* ^^^^^^^^^^^^^
356	* Newly added part. The size is sizeof(u_long).
357	*
358	* However, this is not adopted for tun -> ppp AF_INET packet for
359	* backword compatibility, because the ppp process may be an existing
360	* ip only supporting one.
361	* Also in ppp->tun case, when af value is unknown, (af > 255) is checked and
362	* if it is true, AF_INET is assumed. (the 4byte may be the head of
363	* AF_INET packet. Despite the byte order, the value must always be
364	* greater than 255, because of ip_len field or (ip_v and ip_hl)
365	* field. (Idea from Mr. Noritoshi Demize)
366	*/
367	int
368	tunoutput(ifp, m0, dst, rt)
369	struct ifnet *ifp;
370	struct mbuf *m0;
371	struct sockaddr *dst;
372	struct rtentry *rt;
373	{
374	struct tun_softc *tp = &tunctl[ifp->if_unit];
375	int s;
376
377	TUNDEBUG ("%s%d: tunoutput\n", ifp->if_name, ifp->if_unit);
378
379	if ((tp->tun_flags & TUN_READY) != TUN_READY) {
380	TUNDEBUG ("%s%d: not ready 0%o\n", ifp->if_name,
381	ifp->if_unit, tp->tun_flags);
382	m_freem (m0);
383	return EHOSTDOWN;
384	}
385
386	#if NBPFILTER > 0
387	/* BPF write needs to be handled specially */
388	if (dst->sa_family == AF_UNSPEC) {
389	dst->sa_family = (mtod(m0, int ));
390	m0->m_len -= sizeof(int);
391	m0->m_pkthdr.len -= sizeof(int);
392	m0->m_data += sizeof(int);
393	}
394
395	if (ifp->if_bpf) {
396	/*
397	* We need to prepend the address family as
398	* a four byte field. Cons up a dummy header
399	* to pacify bpf. This is safe because bpf
400	* will only read from the mbuf (i.e., it won't
401	* try to free it or keep a pointer to it).
402	*/
403	struct mbuf m;
404	u_int af = dst->sa_family;
405
406	m.m_next = m0;
407	m.m_len = 4;
408	m.m_data = (char *)⁡
409
410	bpf_mtap(ifp, &m);
411	}
412	#endif
413
414	switch(dst->sa_family) {
415	#if defined(INET) \|\| defined(INET6)
416	#if INET6
417	case AF_INET6:
418	M_PREPEND(m0, sizeof(u_long) /* af field passed to upper */,
419	M_DONTWAIT);
420	if (m0 == 0)
421	return (ENOBUFS);
422	mtod(m0, u_long ) = (u_long)dst->sa_family;
423	/* FALLTHROUGH */
424	#endif /* INET6 */
425	#if INET
426	case AF_INET:
427	#endif /* INET */
428	#endif /* INET \|\| INET6 */
429	s = splimp();
430	if (IF_QFULL(&ifp->if_snd)) {
431	IF_DROP(&ifp->if_snd);
432	m_freem(m0);
433	splx(s);
434	ifp->if_collisions++;
435	return (ENOBUFS);
436	}
437	ifp->if_obytes += m0->m_pkthdr.len;
438	IF_ENQUEUE(&ifp->if_snd, m0);
439	splx(s);
440	ifp->if_opackets++;
441	break;
442	default:
443	m_freem(m0);
444	return EAFNOSUPPORT;
445	}
446
447	if (tp->tun_flags & TUN_RWAIT) {
448	tp->tun_flags &= ~TUN_RWAIT;
449	wakeup((caddr_t)tp);
450	}
451	if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio)
452	pgsigio(tp->tun_sigio, SIGIO, 0);
1c79356b	453	selwakeup(&tp->tun_rsel);
1c79356b A	454	return 0;
	455	}
	456
	457	/*
	458	* the cdevsw interface is now pretty minimal.
	459	*/
	460	static int
	461	tunioctl(dev, cmd, data, flag, p)
	462	dev_t dev;
	463	u_long cmd;
	464	caddr_t data;
	465	int flag;
	466	struct proc *p;
	467	{
	468	int unit = dev_val(minor(dev)), s;
	469	struct tun_softc *tp = &tunctl[unit];
	470	struct tuninfo *tunp;
	471
	472	switch (cmd) {
	473	case TUNSIFINFO:
	474	tunp = (struct tuninfo *)data;
	475	tp->tun_if.if_mtu = tunp->mtu;
	476	tp->tun_if.if_type = tunp->type;
	477	tp->tun_if.if_baudrate = tunp->baudrate;
	478	break;
	479	case TUNGIFINFO:
	480	tunp = (struct tuninfo *)data;
	481	tunp->mtu = tp->tun_if.if_mtu;
	482	tunp->type = tp->tun_if.if_type;
	483	tunp->baudrate = tp->tun_if.if_baudrate;
	484	break;
	485	case TUNSDEBUG:
	486	tundebug = (int )data;
	487	break;
	488	case TUNGDEBUG:
	489	(int )data = tundebug;
	490	break;
	491	case FIONBIO:
	492	break;
	493	case FIOASYNC:
	494	if ((int )data)
	495	tp->tun_flags \|= TUN_ASYNC;
	496	else
	497	tp->tun_flags &= ~TUN_ASYNC;
	498	break;
	499	case FIONREAD:
	500	s = splimp();
	501	if (tp->tun_if.if_snd.ifq_head) {
	502	struct mbuf *mb = tp->tun_if.if_snd.ifq_head;
	503	for( (int )data = 0; mb != 0; mb = mb->m_next)
	504	(int )data += mb->m_len;
	505	} else
	506	(int )data = 0;
	507	splx(s);
	508	break;
	509	case FIOSETOWN:
	510	return (fsetown((int )data, &tp->tun_sigio));
	511
	512	case FIOGETOWN:
	513	(int )data = fgetown(tp->tun_sigio);
	514	return (0);
	515
	516	/* This is deprecated, FIOSETOWN should be used instead. */
	517	case TIOCSPGRP:
518	return (fsetown(-((int )data), &tp->tun_sigio));
519
520	/* This is deprecated, FIOGETOWN should be used instead. */
521	case TIOCGPGRP:
522	(int )data = -fgetown(tp->tun_sigio);
523	return (0);
524
525	default:
526	return (ENOTTY);
527	}
528	return (0);
529	}
530
531	/*
532	* The cdevsw read interface - reads a packet at a time, or at
533	* least as much of a packet as can be read.
534	*/
535	static int
536	tunread(dev, uio, flag)
537	dev_t dev;
538	struct uio *uio;
539	int flag;
540	{
541	int unit = dev_val(minor(dev));
542	struct tun_softc *tp = &tunctl[unit];
543	struct ifnet *ifp = &tp->tun_if;
544	struct mbuf m, m0;
545	int error=0, len, s;
546
547	TUNDEBUG ("%s%d: read\n", ifp->if_name, ifp->if_unit);
548	if ((tp->tun_flags & TUN_READY) != TUN_READY) {
549	TUNDEBUG ("%s%d: not ready 0%o\n", ifp->if_name,
550	ifp->if_unit, tp->tun_flags);
551	return EHOSTDOWN;
552	}
553
554	tp->tun_flags &= ~TUN_RWAIT;
555
556	s = splimp();
557	do {
558	IF_DEQUEUE(&ifp->if_snd, m0);
559	if (m0 == 0) {
560	if (flag & IO_NDELAY) {
561	splx(s);
562	return EWOULDBLOCK;
563	}
564	tp->tun_flags \|= TUN_RWAIT;
565	if( error = tsleep((caddr_t)tp, PCATCH \| (PZERO + 1),
566	"tunread", 0)) {
567	splx(s);
568	return error;
569	}
570	}
571	} while (m0 == 0);
572	splx(s);
573
574	while (m0 && uio->uio_resid > 0 && error == 0) {
575	len = min(uio->uio_resid, m0->m_len);
576	if (len == 0)
577	break;
578	error = uiomove(mtod(m0, caddr_t), len, uio);
579	MFREE(m0, m);
580	m0 = m;
581	}
582
583	if (m0) {
584	TUNDEBUG("Dropping mbuf\n");
585	m_freem(m0);
586	}
587	return error;
588	}
589
590	/*
591	* the cdevsw write interface - an atomic write is a packet - or else!
592	*/
593	/* See top of tunoutput() about interface change between ppp process and
594	* tun. */
595	static int
596	tunwrite(dev, uio, flag)
597	dev_t dev;
598	struct uio *uio;
599	int flag;
600	{
601	int unit = dev_val(minor(dev));
602	struct ifnet *ifp = &tunctl[unit].tun_if;
603	struct mbuf top, mp, m;
604	int error=0, s, tlen, mlen;
605	u_long af;
606	u_int netisr_af;
607	struct ifqueue *afintrq = NULL;
608
609	TUNDEBUG("%s%d: tunwrite\n", ifp->if_name, ifp->if_unit);
610
611	if (uio->uio_resid < 0 \|\| uio->uio_resid > TUNMRU) {
612	TUNDEBUG("%s%d: len=%d!\n", ifp->if_name, ifp->if_unit,
613	uio->uio_resid);
614	return EIO;
615	}
616	tlen = uio->uio_resid;
617
618	/* get a header mbuf */
619	MGETHDR(m, M_DONTWAIT, MT_DATA);
620	if (m == NULL)
621	return ENOBUFS;
622	if (tlen > MHLEN) {
623	MCLGET(m, M_DONTWAIT);
624	if ((m->m_flags & M_EXT) == 0) {
625	m_free(m);
626	return ENOBUFS;
627	}
628	mlen = m->m_ext.ext_size;
629	} else
630	mlen = MHLEN;
631
632	top = 0;
633	mp = &top;
634	while (error == 0 && uio->uio_resid > 0) {
635	m->m_len = min(mlen, uio->uio_resid);
636	error = uiomove(mtod (m, caddr_t), m->m_len, uio);
637	*mp = m;
638	mp = &m->m_next;
639	if (uio->uio_resid > 0) {
640	MGET (m, M_DONTWAIT, MT_DATA);
641	if (m == 0) {
642	error = ENOBUFS;
643	break;
644	}
645	mlen = MLEN;
646	}
647	}
648	/* Change for checking Address Family of sending packet. */
649	af = mtod(top, u_long );
650	switch (af) {
651	#if INET
652	case AF_INET:
653	netisr_af = NETISR_IP;
654	afintrq = &ipintrq;
655	break;
656	#endif /* INET */
657	#if INET6
658	case AF_INET6:
659	netisr_af = NETISR_IPV6;
660	afintrq = &ip6intrq;
661	break;
662	#endif /* INET6 */
663	default:
664	if (af > 255) { /* see description at the top of tunoutput */
665	af = AF_INET;
666	netisr_af = NETISR_IP;
667	afintrq = &ipintrq;
668	goto af_decided;
669	}
670	error = EAFNOSUPPORT;
671	break;
672	}
673	m_adj(top, sizeof(u_long)); /* remove af field passed from upper */
674	tlen -= sizeof(u_long);
675	af_decided:
676	if (error) {
677	if (top)
678	m_freem (top);
679	return error;
680	}
681
682	top->m_pkthdr.len = tlen;
683	top->m_pkthdr.rcvif = ifp;
684
685	#if NBPFILTER > 0
686	if (ifp->if_bpf) {
687	/*
688	* We need to prepend the address family as
689	* a four byte field. Cons up a dummy header
690	* to pacify bpf. This is safe because bpf
691	* will only read from the mbuf (i.e., it won't
692	* try to free it or keep a pointer to it).
693	*/
694	struct mbuf m;
695
696	m.m_next = top;
697	m.m_len = 4;
698	m.m_data = (char *)⁡
699
700	bpf_mtap(ifp, &m);
701	}
702	#endif
703
704	/* just for safety */
705	if (!afintrq)
706	return EAFNOSUPPORT;
707
708	s = splimp();
709	if (IF_QFULL (afintrq)) {
710	IF_DROP(afintrq);
711	splx(s);
712	ifp->if_collisions++;
713	m_freem(top);
714	return ENOBUFS;
715	}
716	IF_ENQUEUE(afintrq, top);
717	splx(s);
718	ifp->if_ibytes += tlen;
719	ifp->if_ipackets++;
720	schednetisr(netisr_af);
721	return error;
722	}
723
724	/*
725	* tunpoll - the poll interface, this is only useful on reads
726	* really. The write detect always returns true, write never blocks
727	* anyway, it either accepts the packet or drops it.
728	*/
729	static int
0b4e3aa0	730	tunpoll(dev, events, wql, p)
1c79356b A	731	dev_t dev;
1c79356b A	732	int events;
0b4e3aa0	733	void * wql;
1c79356b A	734	struct proc *p;
	735	{
	736	int unit = dev_val(minor(dev)), s;
	737	struct tun_softc *tp = &tunctl[unit];
	738	struct ifnet *ifp = &tp->tun_if;
	739	int revents = 0;
	740
	741	s = splimp();
	742	TUNDEBUG("%s%d: tunpoll\n", ifp->if_name, ifp->if_unit);
	743
	744	if (events & (POLLIN \| POLLRDNORM))
	745	if (ifp->if_snd.ifq_len > 0) {
	746	TUNDEBUG("%s%d: tunpoll q=%d\n", ifp->if_name,
	747	ifp->if_unit, ifp->if_snd.ifq_len);
	748	revents \|= events & (POLLIN \| POLLRDNORM);
	749	} else {
	750	TUNDEBUG("%s%d: tunpoll waiting\n", ifp->if_name,
	751	ifp->if_unit);
0b4e3aa0	752	selrecord(p, &tp->tun_rsel, wql);
1c79356b A	753	}
	754
	755	if (events & (POLLOUT \| POLLWRNORM))
	756	revents \|= events & (POLLOUT \| POLLWRNORM);
	757
	758	splx(s);
	759	return (revents);
	760	}
	761
	762
	763	#endif /* NTUN */