freebsd-dev/sys/net/if_tun.c
Brian Somers 5417a1a44a Support more than 256 tun devices:
$ ls -l /dev/tun25[4-7]
crw-------  1 fax  dialer   52, 254 Apr 27 02:27 /dev/tun254
crw-------  1 fax  dialer   52, 255 Apr 27 02:27 /dev/tun255
crw-------  1 fax  dialer   52, 0x00010000 Apr 27 02:31 /dev/tun256
crw-------  1 fax  dialer   52, 0x00010001 Apr 27 02:31 /dev/tun257
1998-04-27 01:44:22 +00:00

639 lines
13 KiB
C

/* $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/kernel.h>
#include <sys/sysctl.h>
#ifdef DEVFS
#include <sys/devfsext.h>
#endif /*DEVFS*/
#include <sys/conf.h>
#include <sys/uio.h>
/*
* XXX stop <sys/vnode.h> from including <vnode_if.h>. <vnode_if.h> doesn't
* exist if we are an LKM.
*/
#undef KERNEL
#include <sys/vnode.h>
#define KERNEL
#include <net/if.h>
#include <net/netisr.h>
#include <net/route.h>
#ifdef INET
#include <netinet/in.h>
#include <netinet/in_var.h>
#endif
#ifdef 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 *, int, caddr_t));
static int tuninit __P((int));
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;
#ifdef 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++ ) {
#ifdef 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_mtu = TUNMTU;
ifp->if_ioctl = tunifioctl;
ifp->if_output = tunoutput;
ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
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) {
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%d: closed\n", ifp->if_name, ifp->if_unit);
return (0);
}
static int
tuninit(unit)
int unit;
{
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) {
#ifdef 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;
int 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:
tuninit(ifp->if_unit);
TUNDEBUG("%s%d: destination address set\n",
ifp->if_name, ifp->if_unit);
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;
default:
error = EINVAL;
}
splx(s);
return (error);
}
/*
* tunoutput - queue packets from higher level ready to put out.
*/
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];
struct proc *p;
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) {
#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);
}
ifp->if_obytes += m0->m_pkthdr.len;
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)) != 0)
psignal(p, SIGIO);
}
selwakeup(&tp->tun_rsel);
return 0;
}
/*
* the cdevsw interface is now pretty minimal.
*/
static int
tunioctl(dev, cmd, data, flag, p)
dev_t dev;
int 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 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.
*/
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!
*/
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;
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;
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);
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;
u_int af = AF_INET;
m.m_next = top;
m.m_len = 4;
m.m_data = (char *)&af;
bpf_mtap(ifp, &m);
}
#endif
#ifdef INET
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_ibytes += tlen;
ifp->if_ipackets++;
schednetisr(NETISR_IP);
#endif
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, p)
dev_t dev;
int events;
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);
}
if (events & (POLLOUT | POLLWRNORM))
revents |= events & (POLLOUT | POLLWRNORM);
splx(s);
return (revents);
}
#endif /* NTUN */