NetBSD/sys/net/if_tun.c

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/* UNFINISHED CONVERSION TO 386BSD -wfj */
/* if_tun.c - tunnel interface module & driver */
/*
* Copyright (c) 1988, Julian Onions.
*
* This source may be freely distributed, however I would be interested
* in any changes that are made.
*/
/*
* 90/02/06 15:03 - Fixed a bug in where TIOCGPGRP and TIOCSPGRP were
* mixed up. Anders Klemets - klemets@sics.se
*
* $Id: if_tun.c,v 1.5 1993/08/09 01:19:38 deraadt Exp $
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*
*/
#include "tun.h"
#if NTUN > 0
/*
* Tunnel driver.
*
* This driver takes packets off the IP i/f and hands them up to a
* user process to have it's 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.
*
* Julian Onions <jpo@cs.nott.ac.uk>
* Nottingham University 1987.
*/
#include "param.h"
#include "systm.h"
#include "mbuf.h"
#include "buf.h"
#include "protosw.h"
#include "socket.h"
#include "ioctl.h"
#include "errno.h"
#include "syslog.h"
#include "select.h"
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#include "net/if.h"
#include "net/netisr.h"
#include "net/route.h"
#ifdef INET
#include "netinet/in.h"
#include "netinet/in_systm.h"
#include "netinet/in_var.h"
#include "netinet/ip.h"
#include "netinet/if_ether.h"
#endif
#ifdef NS
#include "netns/ns.h"
#include "netns/ns_if.h"
#endif
#define TUNDEBUG if (tundebug) printf
int tundebug = 0;
struct tunctl
{
u_short tun_flags; /* misc flags */
struct ifnet tun_if; /* the interface */
int tun_pgrp; /* the process group - if any */
struct selinfo tun_rsel; /* read select */
struct selinfo tun_wsel; /* write select (not used) */
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} tunctl[NTUN];
extern int ifqmaxlen;
int tunoutput (), tunioctl (), tuninit ();
/* tunnel open - must be superuser & the device must be configured in */
tunopen (dev, flag)
dev_t dev;
{
struct proc *p = curproc; /* XXX */
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register int unit;
struct tunctl *tp;
register struct ifnet *ifp;
int error;
if (error = suser(p->p_ucred, &p->p_acflag))
return (error);
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if ((unit = minor (dev)) >= NTUN)
return (ENXIO);
tp = &tunctl[unit];
if (tp->tun_flags & TUN_OPEN)
return ENXIO;
if ((tp->tun_flags & TUN_INITED) == 0) {
tp->tun_flags = TUN_INITED;
tunattach (unit);
}
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 */
tunclose (dev, flag)
dev_t dev;
{
int s;
register int unit = minor (dev);
register struct tunctl *tp = &tunctl[unit];
register struct ifnet *ifp = &tp->tun_if;
register struct mbuf *m;
tp->tun_flags &= TUN_INITED;
/*
* junk all pending output
*/
do {
s = splimp ();
IF_DEQUEUE (&ifp->if_snd, m);
splx (s);
if (m) /* actually - m_freem checks this - but what the hell */
m_freem (m);
} while (m != 0);
if (ifp->if_flags & IFF_UP) {
s = splimp ();
if_down (ifp);
if (ifp->if_flags & IFF_RUNNING)
rtinit (ifp->if_addrlist, (int)SIOCDELRT, RTF_HOST);
splx (s);
}
tp -> tun_pgrp = 0;
if (tp -> tun_rsel)
selwakeup (&tp->tun_rsel);
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tp -> tun_rsel = tp -> tun_wsel = (struct proc *)0;
TUNDEBUG ("%s%d: closed\n", ifp->if_name, ifp->if_unit);
return (0);
}
/*
* attach an interface N.B. argument is not same as other drivers
*/
int
tunattach (unit)
int unit;
{
register struct ifnet *ifp = &tunctl[unit].tun_if;
register struct sockaddr_in *sin;
ifp->if_unit = unit;
ifp->if_name = "tun";
ifp->if_mtu = TUNMTU;
ifp->if_ioctl = tunioctl;
ifp->if_output = tunoutput;
ifp->if_init = tuninit;
#ifndef BSD4_3
sin = (struct sockaddr_in *) & ifp->if_addr;
sin->sin_family = AF_INET;
#endif
ifp->if_flags = IFF_POINTOPOINT;
ifp->if_snd.ifq_maxlen = ifqmaxlen;
ifp->if_collisions = ifp->if_ierrors = ifp->if_oerrors = 0;
ifp->if_ipackets = ifp->if_opackets = 0;
if_attach (ifp);
TUNDEBUG ("%s%d: tunattach\n", ifp->if_name, ifp->if_unit);
return 0;
}
int
tuninit (unit)
int unit;
{
register struct tunctl *tp = &tunctl[unit];
register struct ifnet *ifp = &tp->tun_if;
#ifndef BSD4_3
register struct sockaddr_in *sin;
sin = (struct sockaddr_in *) & ifp->if_addr;
if (sin->sin_addr.s_addr == 0) /* if address still unknown */
return;
if_rtinit (ifp, RTF_UP);
#endif
ifp->if_flags |= IFF_UP | IFF_RUNNING;
tp->tun_flags |= TUN_IASET;
TUNDEBUG ("%s%d: tuninit\n", ifp->if_name, ifp->if_unit);
return 0;
}
/*
* Process an ioctl request.
* The problem here is 4.2 pass a struct ifreq * to this routine,
* sun only passes a struct sockaddr * since 3.2 at least. This is
* rather upsetting! Also, sun doesn't pass the SIOCDSTADDR ioctl through
* so we can't detect this being set directly. This is the reason for
* tuncheckready.
* Under 4.3 and SunOs 4.0 we now get the SIOCSIFDSTADDR ioctl, and we get a
* struct in_ifaddr * for data. (tte)
*/
#if !defined(BSD4_3) && defined(sun)
/*
* workaround for not being able to detect DSTADDR being set.
*/
tuncheckready (ifp)
struct ifnet *ifp;
{
struct tunctl *tp = &tunctl[ifp->if_unit];
struct sockaddr_in *sin;
sin = (struct sockaddr_in *) &ifp->if_dstaddr;
if (sin->sin_addr.s_addr == 0)
return 0;
tp -> tun_flags |= TUN_DSTADDR;
return 1;
}
#else
#define tuncheckready(dummy) 1
#endif /* !defined(BSD4_3) && defined(sun) */
int
tunioctl (ifp, cmd, data)
register struct ifnet *ifp;
int cmd;
caddr_t data;
{
#ifndef BSD4_3
#ifdef sun
struct sockaddr_in *sin = (struct sockaddr_in *) data;
#else
struct sockaddr_in *sin;
struct ifreq *ifr = (struct ifreq *) data;
#endif
#endif /* BSD4_3 */
int s = splimp (), error = 0;
struct tunctl *tp = &tunctl[ifp->if_unit];
switch (cmd)
{
case SIOCSIFADDR:
#ifndef BSD4_3
if (ifp->if_flags & IFF_RUNNING)
if_rtinit (ifp, -1); /* delete previous route */
#ifndef sun
sin = (struct sockaddr_in *)&ifr -> ifr_addr;
#endif
ifp->if_addr = *((struct sockaddr *) sin);
ifp->if_net = in_netof (sin->sin_addr);
ifp->if_host[0] = in_lnaof (sin->sin_addr);
#endif
tuninit (ifp->if_unit);
break;
case SIOCSIFDSTADDR:
tp->tun_flags |= TUN_DSTADDR;
#ifndef BSD4_3
#ifndef sun
sin = (struct sockaddr_in *)&ifr -> ifr_addr;
#endif
ifp->if_dstaddr = *((struct sockaddr *)sin);
#endif BSD4_3
TUNDEBUG ("%s%d: destination addres set\n", ifp->if_name,
ifp -> if_unit);
break;
default:
error = EINVAL;
}
splx (s);
return (error);
}
/*
* tunoutput - queue packets from higher level ready to put out.
*/
tunoutput (ifp, m0, dst)
struct ifnet *ifp;
struct mbuf *m0;
struct sockaddr *dst;
{
struct tunctl *tp;
struct proc *p;
int s;
TUNDEBUG ("%s%d: tunoutput\n", ifp->if_name, ifp->if_unit);
tp = &tunctl[ifp->if_unit];
if ((tp->tun_flags & TUN_READY) != TUN_READY) {
if(tuncheckready(ifp) == 0) {
TUNDEBUG ("%s%d: not ready 0%o\n", ifp->if_name,
ifp->if_unit, tp->tun_flags);
m_freem (m0);
return EHOSTDOWN;
}
}
switch (dst->sa_family) {
#ifdef INET
case AF_INET:
s = splimp ();
if (IF_QFULL (&ifp->if_snd))
{
IF_DROP (&ifp->if_snd);
m_freem (m0);
splx (s);
ifp->if_collisions++;
return (ENOBUFS);
}
IF_ENQUEUE (&ifp->if_snd, m0);
splx (s);
ifp->if_opackets++;
break;
#endif
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_pgrp != 0) {
if (tp->tun_pgrp > 0)
gsignal (tp->tun_pgrp, SIGIO);
else if ((p = pfind (-tp->tun_pgrp)) != 0)
psignal (p, SIGIO);
}
selwakeup (&tp->tun_rsel);
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return 0;
}
/*
* the cdevsw interface is now pretty minimal.
*/
tuncioctl (dev, cmd, data, flag)
dev_t dev;
caddr_t data;
{
int unit = minor(dev);
struct tunctl *tp = &tunctl[unit];
int s;
switch (cmd) {
case TUNSDEBUG:
tundebug = *(int *)data;
break;
case TUNGDEBUG:
*(int *)data = tundebug;
break;
case FIONBIO:
if (*(int *)data)
tp->tun_flags |= TUN_NBIO;
else
tp->tun_flags &= ~TUN_NBIO;
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)
*(int *)data = tp->tun_if.if_snd.ifq_head->m_len;
else *(int *)data = 0;
splx (s);
break;
case TIOCSPGRP:
tp->tun_pgrp = *(int *)data;
break;
case TIOCGPGRP:
*(int *)data = tp->tun_pgrp;
break;
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.
*/
tunread (dev, uio)
dev_t dev;
struct uio *uio;
{
register struct ifnet *ifp;
register struct mbuf *m, *m0;
int unit = minor (dev);
int len, s;
int error = 0;
struct tunctl *tp;
tp = &tunctl[unit];
ifp = &tp->tun_if;
TUNDEBUG ("%s%d: read\n", ifp->if_name, ifp->if_unit);
if ((tp->tun_flags & TUN_READY) != TUN_READY) {
if(tuncheckready(ifp) == 0) {
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 (tp -> tun_flags & TUN_NBIO) {
splx (s);
return EWOULDBLOCK;
}
tp->tun_flags |= TUN_RWAIT;
tsleep ((caddr_t) tp, PZERO + 1, "tunread", 0);
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}
} 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_READ, uio);
MFREE (m0, m);
m0 = m;
}
if (m0 != 0) {
TUNDEBUG ("Dropping mbuf\n");
m_freem (m0);
}
return error;
}
/*
* the cdevsw write interface - an atomic write is a packet - or else!
*/
tunwrite (dev, uio)
int dev;
struct uio *uio;
{
int error = 0;
int unit = minor (dev);
struct mbuf *top, **mp, *m;
struct ifnet *ifp = &(tunctl[unit].tun_if);
int s;
TUNDEBUG ("%s%d: tunwrite\n", ifp->if_name, ifp->if_unit);
if (uio->uio_resid < 0 || uio->uio_resid > TUNMTU) {
TUNDEBUG ("%s%d: len=%d!\n", ifp->if_name, ifp->if_unit,
uio->uio_resid);
return EIO;
}
top = 0;
mp = &top;
while (error == 0 && uio->uio_resid > 0) {
MGET (m, M_DONTWAIT, MT_DATA);
if (m == 0) {
error = ENOBUFS;
break;
}
m->m_len = MIN (MLEN, uio->uio_resid);
error = uiomove (mtod (m, caddr_t), m->m_len, UIO_WRITE, uio);
*mp = m;
mp = &m->m_next;
}
if (error) {
if (top)
m_freem (top);
return error;
}
#ifdef BSD4_3
/*
* Place interface pointer before the data
* for the receiving protocol.
*/
if (top->m_off <= MMAXOFF &&
top->m_off >= MMINOFF + sizeof(struct ifnet *)) {
top->m_off -= sizeof(struct ifnet *);
top->m_len += sizeof(struct ifnet *);
} else {
MGET(m, M_DONTWAIT, MT_HEADER);
if (m == (struct mbuf *)0)
return (ENOBUFS);
m->m_len = sizeof(struct ifnet *);
m->m_next = top;
top = m;
}
*(mtod(top, struct ifnet **)) = ifp;
#endif /* BSD4_3 */
s = splimp ();
if (IF_QFULL (&ipintrq)) {
IF_DROP (&ipintrq);
splx (s);
ifp->if_collisions++;
m_freem (top);
return ENOBUFS;
}
IF_ENQUEUE (&ipintrq, top);
splx (s);
ifp->if_ipackets++;
schednetisr (NETISR_IP);
return error;
}
/*
* tunselect - the select 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.
*/
tunselect (dev, rw)
dev_t dev;
int rw;
{
int unit = minor (dev);
register struct tunctl *tp = &tunctl[unit];
struct ifnet *ifp = &tp->tun_if;
int s = splimp ();
TUNDEBUG ("%s%d: tunselect\n", ifp->if_name, ifp->if_unit);
switch (rw) {
case FREAD:
if (ifp->if_snd.ifq_len > 0) {
splx (s);
TUNDEBUG ("%s%d: tunselect q=%d\n", ifp->if_name,
ifp->if_unit, ifp->if_snd.ifq_len);
return 1;
}
selrecord(p, &tp->tun_rsel);
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break;
case FWRITE:
splx (s);
return 1;
}
splx (s);
TUNDEBUG ("%s%d: tunselect waiting\n", ifp->if_name, ifp->if_unit);
return 0;
}
#endif NTUN