NetBSD/sys/net/if_tun.c
is 07b064e02e New ARP system, supports IPv4 over any hardware link.
Some of the stuff (e.g., rarpd, bootpd, dhcpd etc., libsa) still will
only support Ethernet. Tcpdump itself should be ok, but libpcap needs
lot of work.

For the detailed change history, look at the commit log entries for
the is-newarp branch.
1997-03-15 18:09:08 +00:00

646 lines
12 KiB
C

/* $NetBSD: if_tun.c,v 1.30 1997/03/15 18:12:29 is 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 its
* 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 <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/buf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/errno.h>
#include <sys/syslog.h>
#include <sys/select.h>
#include <sys/poll.h>
#include <sys/file.h>
#include <sys/signalvar.h>
#include <sys/conf.h>
#include <machine/cpu.h>
#include <net/if.h>
#include <net/if_ether.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_inarp.h>
#endif
#ifdef NS
#include <netns/ns.h>
#include <netns/ns_if.h>
#endif
#include "bpfilter.h"
#if NBPFILTER > 0
#include <sys/time.h>
#include <net/bpf.h>
#endif
#include <net/if_tun.h>
#define TUNDEBUG if (tundebug) printf
int tundebug = 0;
struct tun_softc tunctl[NTUN];
extern int ifqmaxlen;
void tunattach __P((int));
int tun_ioctl __P((struct ifnet *, u_long, caddr_t));
int tun_output __P((struct ifnet *, struct mbuf *, struct sockaddr *,
struct rtentry *rt));
static void tuninit __P((struct tun_softc *));
void
tunattach(unused)
int unused;
{
register int i;
struct ifnet *ifp;
for (i = 0; i < NTUN; i++) {
tunctl[i].tun_flags = TUN_INITED;
ifp = &tunctl[i].tun_if;
sprintf(ifp->if_xname, "tun%d", i);
ifp->if_softc = &tunctl[i];
ifp->if_mtu = TUNMTU;
ifp->if_ioctl = tun_ioctl;
ifp->if_output = tun_output;
ifp->if_flags = IFF_POINTOPOINT;
ifp->if_snd.ifq_maxlen = ifqmaxlen;
ifp->if_collisions = 0;
ifp->if_ierrors = 0;
ifp->if_oerrors = 0;
ifp->if_ipackets = 0;
ifp->if_opackets = 0;
if_attach(ifp);
#if NBPFILTER > 0
bpfattach(&tunctl[i].tun_bpf, ifp, DLT_NULL, sizeof(u_int32_t));
#endif
}
}
/*
* tunnel open - must be superuser & the device must be
* configured in
*/
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;
if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
return (error);
if ((unit = minor(dev)) >= NTUN)
return (ENXIO);
tp = &tunctl[unit];
if (tp->tun_flags & TUN_OPEN)
return ENXIO;
ifp = &tp->tun_if;
tp->tun_flags |= TUN_OPEN;
TUNDEBUG("%s: open\n", ifp->if_xname);
return (0);
}
/*
* tunclose - close the device - mark i/f down & delete
* routing info
*/
int
tunclose(dev, flag, mode, p)
dev_t dev;
int flag;
int mode;
struct proc *p;
{
register int unit = 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_addrlist.tqh_first; ifa != 0;
ifa = ifa->ifa_list.tqe_next) {
if (ifa->ifa_addr->sa_family == AF_INET) {
rtinit(ifa, (int)RTM_DELETE,
tp->tun_flags & TUN_DSTADDR
? RTF_HOST
: 0);
}
}
}
splx(s);
}
tp->tun_pgrp = 0;
selwakeup(&tp->tun_rsel);
TUNDEBUG ("%s: closed\n", ifp->if_xname);
return (0);
}
static void
tuninit(tp)
struct tun_softc *tp;
{
struct ifnet *ifp = &tp->tun_if;
register struct ifaddr *ifa;
TUNDEBUG("%s: tuninit\n", ifp->if_xname);
ifp->if_flags |= IFF_UP | IFF_RUNNING;
tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR);
for (ifa = ifp->if_addrlist.tqh_first; ifa != 0;
ifa = ifa->ifa_list.tqe_next) {
if (ifa->ifa_addr->sa_family == AF_INET) {
struct sockaddr_in *sin;
sin = satosin(ifa->ifa_addr);
if (sin && sin->sin_addr.s_addr)
tp->tun_flags |= TUN_IASET;
if (ifp->if_flags & IFF_POINTOPOINT) {
sin = satosin(ifa->ifa_dstaddr);
if (sin && sin->sin_addr.s_addr)
tp->tun_flags |= TUN_DSTADDR;
}
}
}
return;
}
/*
* Process an ioctl request.
*/
int
tun_ioctl(ifp, cmd, data)
struct ifnet *ifp;
u_long cmd;
caddr_t data;
{
int error = 0, s;
s = splimp();
switch(cmd) {
case SIOCSIFADDR:
tuninit((struct tun_softc *)(ifp->if_softc));
TUNDEBUG("%s: address set\n", ifp->if_xname);
break;
case SIOCSIFDSTADDR:
tuninit((struct tun_softc *)(ifp->if_softc));
TUNDEBUG("%s: destination address set\n", ifp->if_xname);
break;
case SIOCSIFBRDADDR:
TUNDEBUG("%s: broadcast address set\n", ifp->if_xname);
break;
default:
error = EINVAL;
}
splx(s);
return (error);
}
/*
* tun_output - queue packets from higher level ready to put out.
*/
int
tun_output(ifp, m0, dst, rt)
struct ifnet *ifp;
struct mbuf *m0;
struct sockaddr *dst;
struct rtentry *rt;
{
struct tun_softc *tp = ifp->if_softc;
struct proc *p;
int s;
TUNDEBUG ("%s: tun_output\n", ifp->if_xname);
if ((tp->tun_flags & TUN_READY) != TUN_READY) {
TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname,
tp->tun_flags);
m_freem (m0);
return (EHOSTDOWN);
}
#if NBPFILTER > 0
if (tp->tun_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_int32_t af = dst->sa_family;
m.m_next = m0;
m.m_len = sizeof(af);
m.m_data = (char *)&af;
bpf_mtap(tp->tun_bpf, &m);
}
#endif
switch(dst->sa_family) {
#ifdef INET
case AF_INET:
if (tp->tun_flags & TUN_PREPADDR) {
/* Simple link-layer header */
M_PREPEND(m0, dst->sa_len, M_DONTWAIT);
if (m0 == NULL) {
IF_DROP(&ifp->if_snd);
return (ENOBUFS);
}
bcopy(dst, mtod(m0, char *), dst->sa_len);
}
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) {
if (tp->tun_pgrp > 0)
gsignal(tp->tun_pgrp, SIGIO);
else if ((p = pfind(-tp->tun_pgrp)) != NULL)
psignal(p, SIGIO);
}
selwakeup(&tp->tun_rsel);
return (0);
}
/*
* the cdevsw interface is now pretty minimal.
*/
int
tunioctl(dev, cmd, data, flag, p)
dev_t dev;
u_long cmd;
caddr_t data;
int flag;
struct proc *p;
{
int unit = minor(dev), s;
struct tun_softc *tp = &tunctl[unit];
switch (cmd) {
case TUNSDEBUG:
tundebug = *(int *)data;
break;
case TUNGDEBUG:
*(int *)data = tundebug;
break;
case TUNSIFMODE:
switch (*(int *)data) {
case IFF_POINTOPOINT:
case IFF_BROADCAST:
s = splimp();
if (tp->tun_if.if_flags & IFF_UP) {
splx(s);
return (EBUSY);
}
tp->tun_if.if_flags &=
~(IFF_BROADCAST|IFF_POINTOPOINT);
tp->tun_if.if_flags |= *(int *)data;
splx(s);
break;
default:
return (EINVAL);
break;
}
break;
case TUNSLMODE:
if (*(int *)data)
tp->tun_flags |= TUN_PREPADDR;
else
tp->tun_flags &= ~TUN_PREPADDR;
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_pkthdr.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.
*/
int
tunread(dev, uio, ioflag)
dev_t dev;
struct uio *uio;
int ioflag;
{
int unit = 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: read\n", ifp->if_xname);
if ((tp->tun_flags & TUN_READY) != TUN_READY) {
TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, 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;
if (tsleep((caddr_t)tp, PZERO|PCATCH, "tunread", 0)) {
splx(s);
return (EINTR);
}
}
} 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);
}
if (error)
ifp->if_ierrors++;
return (error);
}
/*
* the cdevsw write interface - an atomic write is a packet - or else!
*/
int
tunwrite(dev, uio, ioflag)
dev_t dev;
struct uio *uio;
int ioflag;
{
int unit = minor (dev);
struct tun_softc *tp = &tunctl[unit];
struct ifnet *ifp = &tp->tun_if;
struct mbuf *top, **mp, *m;
struct ifqueue *ifq;
struct sockaddr dst;
int isr, error=0, s, tlen, mlen;
TUNDEBUG("%s: tunwrite\n", ifp->if_xname);
if (tp->tun_flags & TUN_PREPADDR) {
if (uio->uio_resid < sizeof(dst))
return (EIO);
error = uiomove((caddr_t)&dst, sizeof(dst), uio);
if (dst.sa_len > sizeof(dst)) {
/* Duh.. */
char discard;
int n = dst.sa_len - sizeof(dst);
while (n--)
if ((error = uiomove(&discard, 1, uio)) != 0)
return (error);
}
} else {
#ifdef INET
dst.sa_family = AF_INET;
#endif
}
if (uio->uio_resid < 0 || uio->uio_resid > TUNMTU) {
TUNDEBUG("%s: len=%d!\n", ifp->if_xname, uio->uio_resid);
return (EIO);
}
switch (dst.sa_family) {
#ifdef INET
case AF_INET:
ifq = &ipintrq;
isr = NETISR_IP;
break;
#endif
default:
return (EAFNOSUPPORT);
}
tlen = uio->uio_resid;
/* get a header mbuf */
MGETHDR(m, M_DONTWAIT, MT_DATA);
if (m == NULL)
return (ENOBUFS);
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;
}
}
if (error) {
if (top)
m_freem (top);
ifp->if_ierrors++;
return (error);
}
top->m_pkthdr.len = tlen;
top->m_pkthdr.rcvif = ifp;
#if NBPFILTER > 0
if (tp->tun_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_int32_t af = AF_INET;
m.m_next = top;
m.m_len = sizeof(af);
m.m_data = (char *)&af;
bpf_mtap(tp->tun_bpf, &m);
}
#endif
s = splimp();
if (IF_QFULL(ifq)) {
IF_DROP(ifq);
splx(s);
ifp->if_collisions++;
m_freem(top);
return (ENOBUFS);
}
IF_ENQUEUE(ifq, top);
splx(s);
ifp->if_ipackets++;
schednetisr(isr);
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.
*/
int
tunpoll(dev, events, p)
dev_t dev;
int events;
struct proc *p;
{
int unit = minor(dev), s;
struct tun_softc *tp = &tunctl[unit];
struct ifnet *ifp = &tp->tun_if;
int revents = 0;
s = splimp();
TUNDEBUG("%s: tunpoll\n", ifp->if_xname);
if (events & (POLLIN | POLLRDNORM))
if (ifp->if_snd.ifq_len > 0) {
TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname,
ifp->if_snd.ifq_len);
revents |= events & (POLLIN | POLLRDNORM);
} else {
TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname);
selrecord(p, &tp->tun_rsel);
}
if (events & (POLLOUT | POLLWRNORM))
revents |= events & (POLLOUT | POLLWRNORM);
splx(s);
return (revents);
}
#endif /* NTUN */