freebsd-dev/sys/net/if_tun.c

1034 lines
24 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.
*
* $FreeBSD$
*/
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/jail.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/socket.h>
#include <sys/fcntl.h>
#include <sys/filio.h>
#include <sys/sockio.h>
#include <sys/ttycom.h>
#include <sys/poll.h>
#include <sys/selinfo.h>
#include <sys/signalvar.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/conf.h>
#include <sys/uio.h>
#include <sys/malloc.h>
#include <sys/random.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_clone.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/route.h>
#include <net/vnet.h>
#ifdef INET
#include <netinet/in.h>
#endif
#include <net/bpf.h>
#include <net/if_tun.h>
#include <sys/queue.h>
#include <sys/condvar.h>
#include <security/mac/mac_framework.h>
/*
* tun_list is protected by global tunmtx. Other mutable fields are
* protected by tun->tun_mtx, or by their owning subsystem. tun_dev is
* static for the duration of a tunnel interface.
*/
struct tun_softc {
TAILQ_ENTRY(tun_softc) tun_list;
struct cdev *tun_dev;
u_short tun_flags; /* misc flags */
#define TUN_OPEN 0x0001
#define TUN_INITED 0x0002
#define TUN_RCOLL 0x0004
#define TUN_IASET 0x0008
#define TUN_DSTADDR 0x0010
#define TUN_LMODE 0x0020
#define TUN_RWAIT 0x0040
#define TUN_ASYNC 0x0080
#define TUN_IFHEAD 0x0100
#define TUN_READY (TUN_OPEN | TUN_INITED)
/*
* XXXRW: tun_pid is used to exclusively lock /dev/tun. Is this
* actually needed? Can we just return EBUSY if already open?
* Problem is that this involved inherent races when a tun device
* is handed off from one process to another, as opposed to just
* being slightly stale informationally.
*/
pid_t tun_pid; /* owning pid */
struct ifnet *tun_ifp; /* the interface */
struct sigio *tun_sigio; /* information for async I/O */
struct selinfo tun_rsel; /* read select */
struct mtx tun_mtx; /* protect mutable softc fields */
struct cv tun_cv; /* protect against ref'd dev destroy */
};
#define TUN2IFP(sc) ((sc)->tun_ifp)
#define TUNDEBUG if (tundebug) if_printf
/*
* All mutable global variables in if_tun are locked using tunmtx, with
* the exception of tundebug, which is used unlocked, and tunclones,
* which is static after setup.
*/
static struct mtx tunmtx;
static const char tunname[] = "tun";
static MALLOC_DEFINE(M_TUN, tunname, "Tunnel Interface");
static int tundebug = 0;
static int tundclone = 1;
static struct clonedevs *tunclones;
static TAILQ_HEAD(,tun_softc) tunhead = TAILQ_HEAD_INITIALIZER(tunhead);
SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");
SYSCTL_DECL(_net_link);
static SYSCTL_NODE(_net_link, OID_AUTO, tun, CTLFLAG_RW, 0,
"IP tunnel software network interface.");
SYSCTL_INT(_net_link_tun, OID_AUTO, devfs_cloning, CTLFLAG_RWTUN, &tundclone, 0,
"Enable legacy devfs interface creation.");
static void tunclone(void *arg, struct ucred *cred, char *name,
int namelen, struct cdev **dev);
static void tuncreate(const char *name, struct cdev *dev);
static int tunifioctl(struct ifnet *, u_long, caddr_t);
static void tuninit(struct ifnet *);
static int tunmodevent(module_t, int, void *);
static int tunoutput(struct ifnet *, struct mbuf *,
const struct sockaddr *, struct route *ro);
static void tunstart(struct ifnet *);
static int tun_clone_create(struct if_clone *, int, caddr_t);
static void tun_clone_destroy(struct ifnet *);
static struct if_clone *tun_cloner;
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;
static d_kqfilter_t tunkqfilter;
static int tunkqread(struct knote *, long);
static int tunkqwrite(struct knote *, long);
static void tunkqdetach(struct knote *);
static struct filterops tun_read_filterops = {
.f_isfd = 1,
.f_attach = NULL,
.f_detach = tunkqdetach,
.f_event = tunkqread,
};
static struct filterops tun_write_filterops = {
.f_isfd = 1,
.f_attach = NULL,
.f_detach = tunkqdetach,
.f_event = tunkqwrite,
};
static struct cdevsw tun_cdevsw = {
.d_version = D_VERSION,
.d_flags = D_NEEDMINOR,
.d_open = tunopen,
.d_close = tunclose,
.d_read = tunread,
.d_write = tunwrite,
.d_ioctl = tunioctl,
.d_poll = tunpoll,
.d_kqfilter = tunkqfilter,
.d_name = tunname,
};
static int
tun_clone_create(struct if_clone *ifc, int unit, caddr_t params)
{
struct cdev *dev;
int i;
/* find any existing device, or allocate new unit number */
i = clone_create(&tunclones, &tun_cdevsw, &unit, &dev, 0);
if (i) {
/* No preexisting struct cdev *, create one */
dev = make_dev(&tun_cdevsw, unit,
UID_UUCP, GID_DIALER, 0600, "%s%d", tunname, unit);
}
tuncreate(tunname, dev);
return (0);
}
static void
tunclone(void *arg, struct ucred *cred, char *name, int namelen,
struct cdev **dev)
{
char devname[SPECNAMELEN + 1];
int u, i, append_unit;
if (*dev != NULL)
return;
/*
* If tun cloning is enabled, only the superuser can create an
* interface.
*/
if (!tundclone || priv_check_cred(cred, PRIV_NET_IFCREATE, 0) != 0)
return;
if (strcmp(name, tunname) == 0) {
u = -1;
} else if (dev_stdclone(name, NULL, tunname, &u) != 1)
return; /* Don't recognise the name */
if (u != -1 && u > IF_MAXUNIT)
return; /* Unit number too high */
if (u == -1)
append_unit = 1;
else
append_unit = 0;
CURVNET_SET(CRED_TO_VNET(cred));
/* find any existing device, or allocate new unit number */
i = clone_create(&tunclones, &tun_cdevsw, &u, dev, 0);
if (i) {
if (append_unit) {
namelen = snprintf(devname, sizeof(devname), "%s%d",
name, u);
name = devname;
}
/* No preexisting struct cdev *, create one */
*dev = make_dev_credf(MAKEDEV_REF, &tun_cdevsw, u, cred,
UID_UUCP, GID_DIALER, 0600, "%s", name);
}
if_clone_create(name, namelen, NULL);
CURVNET_RESTORE();
}
static void
tun_destroy(struct tun_softc *tp)
{
struct cdev *dev;
mtx_lock(&tp->tun_mtx);
if ((tp->tun_flags & TUN_OPEN) != 0)
cv_wait_unlock(&tp->tun_cv, &tp->tun_mtx);
else
mtx_unlock(&tp->tun_mtx);
CURVNET_SET(TUN2IFP(tp)->if_vnet);
dev = tp->tun_dev;
bpfdetach(TUN2IFP(tp));
if_detach(TUN2IFP(tp));
if_free(TUN2IFP(tp));
destroy_dev(dev);
seldrain(&tp->tun_rsel);
knlist_clear(&tp->tun_rsel.si_note, 0);
knlist_destroy(&tp->tun_rsel.si_note);
mtx_destroy(&tp->tun_mtx);
cv_destroy(&tp->tun_cv);
free(tp, M_TUN);
CURVNET_RESTORE();
}
static void
tun_clone_destroy(struct ifnet *ifp)
{
struct tun_softc *tp = ifp->if_softc;
mtx_lock(&tunmtx);
TAILQ_REMOVE(&tunhead, tp, tun_list);
mtx_unlock(&tunmtx);
tun_destroy(tp);
}
static int
tunmodevent(module_t mod, int type, void *data)
{
static eventhandler_tag tag;
struct tun_softc *tp;
switch (type) {
case MOD_LOAD:
mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF);
clone_setup(&tunclones);
tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000);
if (tag == NULL)
return (ENOMEM);
tun_cloner = if_clone_simple(tunname, tun_clone_create,
tun_clone_destroy, 0);
break;
case MOD_UNLOAD:
if_clone_detach(tun_cloner);
EVENTHANDLER_DEREGISTER(dev_clone, tag);
drain_dev_clone_events();
mtx_lock(&tunmtx);
while ((tp = TAILQ_FIRST(&tunhead)) != NULL) {
TAILQ_REMOVE(&tunhead, tp, tun_list);
mtx_unlock(&tunmtx);
tun_destroy(tp);
mtx_lock(&tunmtx);
}
mtx_unlock(&tunmtx);
clone_cleanup(&tunclones);
mtx_destroy(&tunmtx);
break;
default:
return EOPNOTSUPP;
}
return 0;
}
static moduledata_t tun_mod = {
"if_tun",
tunmodevent,
0
};
DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
MODULE_VERSION(if_tun, 1);
static void
tunstart(struct ifnet *ifp)
{
struct tun_softc *tp = ifp->if_softc;
struct mbuf *m;
TUNDEBUG(ifp,"%s starting\n", ifp->if_xname);
if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
IFQ_LOCK(&ifp->if_snd);
IFQ_POLL_NOLOCK(&ifp->if_snd, m);
if (m == NULL) {
IFQ_UNLOCK(&ifp->if_snd);
return;
}
IFQ_UNLOCK(&ifp->if_snd);
}
mtx_lock(&tp->tun_mtx);
if (tp->tun_flags & TUN_RWAIT) {
tp->tun_flags &= ~TUN_RWAIT;
wakeup(tp);
}
selwakeuppri(&tp->tun_rsel, PZERO + 1);
KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) {
mtx_unlock(&tp->tun_mtx);
pgsigio(&tp->tun_sigio, SIGIO, 0);
} else
mtx_unlock(&tp->tun_mtx);
}
/* XXX: should return an error code so it can fail. */
static void
tuncreate(const char *name, struct cdev *dev)
{
struct tun_softc *sc;
struct ifnet *ifp;
sc = malloc(sizeof(*sc), M_TUN, M_WAITOK | M_ZERO);
mtx_init(&sc->tun_mtx, "tun_mtx", NULL, MTX_DEF);
cv_init(&sc->tun_cv, "tun_condvar");
sc->tun_flags = TUN_INITED;
sc->tun_dev = dev;
mtx_lock(&tunmtx);
TAILQ_INSERT_TAIL(&tunhead, sc, tun_list);
mtx_unlock(&tunmtx);
ifp = sc->tun_ifp = if_alloc(IFT_PPP);
if (ifp == NULL)
panic("%s%d: failed to if_alloc() interface.\n",
name, dev2unit(dev));
if_initname(ifp, name, dev2unit(dev));
ifp->if_mtu = TUNMTU;
ifp->if_ioctl = tunifioctl;
ifp->if_output = tunoutput;
ifp->if_start = tunstart;
ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
ifp->if_softc = sc;
IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
ifp->if_snd.ifq_drv_maxlen = 0;
IFQ_SET_READY(&ifp->if_snd);
knlist_init_mtx(&sc->tun_rsel.si_note, &sc->tun_mtx);
ifp->if_capabilities |= IFCAP_LINKSTATE;
ifp->if_capenable |= IFCAP_LINKSTATE;
if_attach(ifp);
bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
dev->si_drv1 = sc;
TUNDEBUG(ifp, "interface %s is created, minor = %#x\n",
ifp->if_xname, dev2unit(dev));
}
static int
tunopen(struct cdev *dev, int flag, int mode, struct thread *td)
{
struct ifnet *ifp;
struct tun_softc *tp;
/*
* XXXRW: Non-atomic test and set of dev->si_drv1 requires
* synchronization.
*/
tp = dev->si_drv1;
if (!tp) {
tuncreate(tunname, dev);
tp = dev->si_drv1;
}
/*
* XXXRW: This use of tun_pid is subject to error due to the
* fact that a reference to the tunnel can live beyond the
* death of the process that created it. Can we replace this
* with a simple busy flag?
*/
mtx_lock(&tp->tun_mtx);
if (tp->tun_pid != 0 && tp->tun_pid != td->td_proc->p_pid) {
mtx_unlock(&tp->tun_mtx);
return (EBUSY);
}
tp->tun_pid = td->td_proc->p_pid;
tp->tun_flags |= TUN_OPEN;
ifp = TUN2IFP(tp);
if_link_state_change(ifp, LINK_STATE_UP);
TUNDEBUG(ifp, "open\n");
mtx_unlock(&tp->tun_mtx);
return (0);
}
/*
* tunclose - close the device - mark i/f down & delete
* routing info
*/
static int
tunclose(struct cdev *dev, int foo, int bar, struct thread *td)
{
struct tun_softc *tp;
struct ifnet *ifp;
tp = dev->si_drv1;
ifp = TUN2IFP(tp);
mtx_lock(&tp->tun_mtx);
tp->tun_flags &= ~TUN_OPEN;
tp->tun_pid = 0;
/*
* junk all pending output
*/
CURVNET_SET(ifp->if_vnet);
IFQ_PURGE(&ifp->if_snd);
if (ifp->if_flags & IFF_UP) {
mtx_unlock(&tp->tun_mtx);
if_down(ifp);
mtx_lock(&tp->tun_mtx);
}
/* Delete all addresses and routes which reference this interface. */
if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
struct ifaddr *ifa;
ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
mtx_unlock(&tp->tun_mtx);
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
/* deal w/IPv4 PtP destination; unlocked read */
if (ifa->ifa_addr->sa_family == AF_INET) {
rtinit(ifa, (int)RTM_DELETE,
tp->tun_flags & TUN_DSTADDR ? RTF_HOST : 0);
} else {
rtinit(ifa, (int)RTM_DELETE, 0);
}
}
if_purgeaddrs(ifp);
mtx_lock(&tp->tun_mtx);
}
if_link_state_change(ifp, LINK_STATE_DOWN);
CURVNET_RESTORE();
funsetown(&tp->tun_sigio);
selwakeuppri(&tp->tun_rsel, PZERO + 1);
KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
TUNDEBUG (ifp, "closed\n");
cv_broadcast(&tp->tun_cv);
mtx_unlock(&tp->tun_mtx);
return (0);
}
static void
tuninit(struct ifnet *ifp)
{
struct tun_softc *tp = ifp->if_softc;
#ifdef INET
struct ifaddr *ifa;
#endif
TUNDEBUG(ifp, "tuninit\n");
mtx_lock(&tp->tun_mtx);
ifp->if_flags |= IFF_UP;
ifp->if_drv_flags |= IFF_DRV_RUNNING;
getmicrotime(&ifp->if_lastchange);
#ifdef INET
if_addr_rlock(ifp);
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family == AF_INET) {
struct sockaddr_in *si;
si = (struct sockaddr_in *)ifa->ifa_addr;
if (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;
}
}
if_addr_runlock(ifp);
#endif
mtx_unlock(&tp->tun_mtx);
}
/*
* Process an ioctl request.
*/
static int
tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
struct ifreq *ifr = (struct ifreq *)data;
struct tun_softc *tp = ifp->if_softc;
struct ifstat *ifs;
int error = 0;
switch(cmd) {
case SIOCGIFSTATUS:
ifs = (struct ifstat *)data;
mtx_lock(&tp->tun_mtx);
if (tp->tun_pid)
snprintf(ifs->ascii, sizeof(ifs->ascii),
"\tOpened by PID %d\n", tp->tun_pid);
else
ifs->ascii[0] = '\0';
mtx_unlock(&tp->tun_mtx);
break;
case SIOCSIFADDR:
tuninit(ifp);
TUNDEBUG(ifp, "address set\n");
break;
case SIOCSIFMTU:
ifp->if_mtu = ifr->ifr_mtu;
TUNDEBUG(ifp, "mtu set\n");
break;
case SIOCSIFFLAGS:
case SIOCADDMULTI:
case SIOCDELMULTI:
break;
default:
error = EINVAL;
}
return (error);
}
/*
* tunoutput - queue packets from higher level ready to put out.
*/
static int
tunoutput(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
struct route *ro)
{
struct tun_softc *tp = ifp->if_softc;
u_short cached_tun_flags;
int error;
u_int32_t af;
TUNDEBUG (ifp, "tunoutput\n");
#ifdef MAC
error = mac_ifnet_check_transmit(ifp, m0);
if (error) {
m_freem(m0);
return (error);
}
#endif
/* Could be unlocked read? */
mtx_lock(&tp->tun_mtx);
cached_tun_flags = tp->tun_flags;
mtx_unlock(&tp->tun_mtx);
if ((cached_tun_flags & TUN_READY) != TUN_READY) {
TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
m_freem (m0);
return (EHOSTDOWN);
}
if ((ifp->if_flags & IFF_UP) != IFF_UP) {
m_freem (m0);
return (EHOSTDOWN);
}
/* BPF writes need to be handled specially. */
if (dst->sa_family == AF_UNSPEC)
bcopy(dst->sa_data, &af, sizeof(af));
else
af = dst->sa_family;
if (bpf_peers_present(ifp->if_bpf))
bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m0);
/* prepend sockaddr? this may abort if the mbuf allocation fails */
if (cached_tun_flags & TUN_LMODE) {
/* allocate space for sockaddr */
M_PREPEND(m0, dst->sa_len, M_NOWAIT);
/* if allocation failed drop packet */
if (m0 == NULL) {
ifp->if_iqdrops++;
ifp->if_oerrors++;
return (ENOBUFS);
} else {
bcopy(dst, m0->m_data, dst->sa_len);
}
}
if (cached_tun_flags & TUN_IFHEAD) {
/* Prepend the address family */
M_PREPEND(m0, 4, M_NOWAIT);
/* if allocation failed drop packet */
if (m0 == NULL) {
ifp->if_iqdrops++;
ifp->if_oerrors++;
return (ENOBUFS);
} else
*(u_int32_t *)m0->m_data = htonl(af);
} else {
#ifdef INET
if (af != AF_INET)
#endif
{
m_freem(m0);
return (EAFNOSUPPORT);
}
}
error = (ifp->if_transmit)(ifp, m0);
if (error)
return (ENOBUFS);
ifp->if_opackets++;
return (0);
}
/*
* the cdevsw interface is now pretty minimal.
*/
static int
tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag,
struct thread *td)
{
int error;
struct tun_softc *tp = dev->si_drv1;
struct tuninfo *tunp;
switch (cmd) {
case TUNSIFINFO:
tunp = (struct tuninfo *)data;
if (tunp->mtu < IF_MINMTU)
return (EINVAL);
if (TUN2IFP(tp)->if_mtu != tunp->mtu) {
error = priv_check(td, PRIV_NET_SETIFMTU);
if (error)
return (error);
}
mtx_lock(&tp->tun_mtx);
TUN2IFP(tp)->if_mtu = tunp->mtu;
TUN2IFP(tp)->if_type = tunp->type;
TUN2IFP(tp)->if_baudrate = tunp->baudrate;
mtx_unlock(&tp->tun_mtx);
break;
case TUNGIFINFO:
tunp = (struct tuninfo *)data;
mtx_lock(&tp->tun_mtx);
tunp->mtu = TUN2IFP(tp)->if_mtu;
tunp->type = TUN2IFP(tp)->if_type;
tunp->baudrate = TUN2IFP(tp)->if_baudrate;
mtx_unlock(&tp->tun_mtx);
break;
case TUNSDEBUG:
tundebug = *(int *)data;
break;
case TUNGDEBUG:
*(int *)data = tundebug;
break;
case TUNSLMODE:
mtx_lock(&tp->tun_mtx);
if (*(int *)data) {
tp->tun_flags |= TUN_LMODE;
tp->tun_flags &= ~TUN_IFHEAD;
} else
tp->tun_flags &= ~TUN_LMODE;
mtx_unlock(&tp->tun_mtx);
break;
case TUNSIFHEAD:
mtx_lock(&tp->tun_mtx);
if (*(int *)data) {
tp->tun_flags |= TUN_IFHEAD;
tp->tun_flags &= ~TUN_LMODE;
} else
tp->tun_flags &= ~TUN_IFHEAD;
mtx_unlock(&tp->tun_mtx);
break;
case TUNGIFHEAD:
mtx_lock(&tp->tun_mtx);
*(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
mtx_unlock(&tp->tun_mtx);
break;
case TUNSIFMODE:
/* deny this if UP */
if (TUN2IFP(tp)->if_flags & IFF_UP)
return(EBUSY);
switch (*(int *)data & ~IFF_MULTICAST) {
case IFF_POINTOPOINT:
case IFF_BROADCAST:
mtx_lock(&tp->tun_mtx);
TUN2IFP(tp)->if_flags &=
~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
TUN2IFP(tp)->if_flags |= *(int *)data;
mtx_unlock(&tp->tun_mtx);
break;
default:
return(EINVAL);
}
break;
case TUNSIFPID:
mtx_lock(&tp->tun_mtx);
tp->tun_pid = curthread->td_proc->p_pid;
mtx_unlock(&tp->tun_mtx);
break;
case FIONBIO:
break;
case FIOASYNC:
mtx_lock(&tp->tun_mtx);
if (*(int *)data)
tp->tun_flags |= TUN_ASYNC;
else
tp->tun_flags &= ~TUN_ASYNC;
mtx_unlock(&tp->tun_mtx);
break;
case FIONREAD:
if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) {
struct mbuf *mb;
IFQ_LOCK(&TUN2IFP(tp)->if_snd);
IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb);
for (*(int *)data = 0; mb != NULL; mb = mb->m_next)
*(int *)data += mb->m_len;
IFQ_UNLOCK(&TUN2IFP(tp)->if_snd);
} else
*(int *)data = 0;
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(struct cdev *dev, struct uio *uio, int flag)
{
struct tun_softc *tp = dev->si_drv1;
struct ifnet *ifp = TUN2IFP(tp);
struct mbuf *m;
int error=0, len;
TUNDEBUG (ifp, "read\n");
mtx_lock(&tp->tun_mtx);
if ((tp->tun_flags & TUN_READY) != TUN_READY) {
mtx_unlock(&tp->tun_mtx);
TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
return (EHOSTDOWN);
}
tp->tun_flags &= ~TUN_RWAIT;
do {
IFQ_DEQUEUE(&ifp->if_snd, m);
if (m == NULL) {
if (flag & O_NONBLOCK) {
mtx_unlock(&tp->tun_mtx);
return (EWOULDBLOCK);
}
tp->tun_flags |= TUN_RWAIT;
error = mtx_sleep(tp, &tp->tun_mtx, PCATCH | (PZERO + 1),
"tunread", 0);
if (error != 0) {
mtx_unlock(&tp->tun_mtx);
return (error);
}
}
} while (m == NULL);
mtx_unlock(&tp->tun_mtx);
while (m && uio->uio_resid > 0 && error == 0) {
len = min(uio->uio_resid, m->m_len);
if (len != 0)
error = uiomove(mtod(m, void *), len, uio);
m = m_free(m);
}
if (m) {
TUNDEBUG(ifp, "Dropping mbuf\n");
m_freem(m);
}
return (error);
}
/*
* the cdevsw write interface - an atomic write is a packet - or else!
*/
static int
tunwrite(struct cdev *dev, struct uio *uio, int flag)
{
struct tun_softc *tp = dev->si_drv1;
struct ifnet *ifp = TUN2IFP(tp);
struct mbuf *m;
uint32_t family;
int isr;
TUNDEBUG(ifp, "tunwrite\n");
if ((ifp->if_flags & IFF_UP) != IFF_UP)
/* ignore silently */
return (0);
if (uio->uio_resid == 0)
return (0);
if (uio->uio_resid < 0 || uio->uio_resid > TUNMRU) {
TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid);
return (EIO);
}
if ((m = m_uiotombuf(uio, M_NOWAIT, 0, 0, M_PKTHDR)) == NULL) {
ifp->if_ierrors++;
return (ENOBUFS);
}
m->m_pkthdr.rcvif = ifp;
#ifdef MAC
mac_ifnet_create_mbuf(ifp, m);
#endif
/* Could be unlocked read? */
mtx_lock(&tp->tun_mtx);
if (tp->tun_flags & TUN_IFHEAD) {
mtx_unlock(&tp->tun_mtx);
if (m->m_len < sizeof(family) &&
(m = m_pullup(m, sizeof(family))) == NULL)
return (ENOBUFS);
family = ntohl(*mtod(m, u_int32_t *));
m_adj(m, sizeof(family));
} else {
mtx_unlock(&tp->tun_mtx);
family = AF_INET;
}
BPF_MTAP2(ifp, &family, sizeof(family), m);
switch (family) {
#ifdef INET
case AF_INET:
isr = NETISR_IP;
break;
#endif
#ifdef INET6
case AF_INET6:
isr = NETISR_IPV6;
break;
#endif
default:
m_freem(m);
return (EAFNOSUPPORT);
}
if (harvest.point_to_point)
random_harvest(&(m->m_data), 12, 2, RANDOM_NET_TUN);
ifp->if_ibytes += m->m_pkthdr.len;
ifp->if_ipackets++;
CURVNET_SET(ifp->if_vnet);
M_SETFIB(m, ifp->if_fib);
netisr_dispatch(isr, m);
CURVNET_RESTORE();
return (0);
}
/*
* 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(struct cdev *dev, int events, struct thread *td)
{
struct tun_softc *tp = dev->si_drv1;
struct ifnet *ifp = TUN2IFP(tp);
int revents = 0;
struct mbuf *m;
TUNDEBUG(ifp, "tunpoll\n");
if (events & (POLLIN | POLLRDNORM)) {
IFQ_LOCK(&ifp->if_snd);
IFQ_POLL_NOLOCK(&ifp->if_snd, m);
if (m != NULL) {
TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len);
revents |= events & (POLLIN | POLLRDNORM);
} else {
TUNDEBUG(ifp, "tunpoll waiting\n");
selrecord(td, &tp->tun_rsel);
}
IFQ_UNLOCK(&ifp->if_snd);
}
if (events & (POLLOUT | POLLWRNORM))
revents |= events & (POLLOUT | POLLWRNORM);
return (revents);
}
/*
* tunkqfilter - support for the kevent() system call.
*/
static int
tunkqfilter(struct cdev *dev, struct knote *kn)
{
struct tun_softc *tp = dev->si_drv1;
struct ifnet *ifp = TUN2IFP(tp);
switch(kn->kn_filter) {
case EVFILT_READ:
TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n",
ifp->if_xname, dev2unit(dev));
kn->kn_fop = &tun_read_filterops;
break;
case EVFILT_WRITE:
TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n",
ifp->if_xname, dev2unit(dev));
kn->kn_fop = &tun_write_filterops;
break;
default:
TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n",
ifp->if_xname, dev2unit(dev));
return(EINVAL);
}
kn->kn_hook = tp;
knlist_add(&tp->tun_rsel.si_note, kn, 0);
return (0);
}
/*
* Return true of there is data in the interface queue.
*/
static int
tunkqread(struct knote *kn, long hint)
{
int ret;
struct tun_softc *tp = kn->kn_hook;
struct cdev *dev = tp->tun_dev;
struct ifnet *ifp = TUN2IFP(tp);
if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) {
TUNDEBUG(ifp,
"%s have data in the queue. Len = %d, minor = %#x\n",
ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev));
ret = 1;
} else {
TUNDEBUG(ifp,
"%s waiting for data, minor = %#x\n", ifp->if_xname,
dev2unit(dev));
ret = 0;
}
return (ret);
}
/*
* Always can write, always return MTU in kn->data.
*/
static int
tunkqwrite(struct knote *kn, long hint)
{
struct tun_softc *tp = kn->kn_hook;
struct ifnet *ifp = TUN2IFP(tp);
kn->kn_data = ifp->if_mtu;
return (1);
}
static void
tunkqdetach(struct knote *kn)
{
struct tun_softc *tp = kn->kn_hook;
knlist_remove(&tp->tun_rsel.si_note, kn, 0);
}