NetBSD-5.0.2/sys/net/if_tun.c
/* $NetBSD: if_tun.c,v 1.107 2008/06/15 16:37:21 christos 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: if_tun.c,v 1.107 2008/06/15 16:37:21 christos Exp $");
#include "opt_inet.h"
#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 <sys/kauth.h>
#include <sys/simplelock.h>
#include <sys/cpu.h>
#include <net/if.h>
#include <net/if_types.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
#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;
extern int ifqmaxlen;
void tunattach(int);
static LIST_HEAD(, tun_softc) tun_softc_list;
static LIST_HEAD(, tun_softc) tunz_softc_list;
static struct simplelock tun_softc_lock;
static int tun_ioctl(struct ifnet *, u_long, void *);
static int tun_output(struct ifnet *, struct mbuf *,
const struct sockaddr *, struct rtentry *rt);
static int tun_clone_create(struct if_clone *, int);
static int tun_clone_destroy(struct ifnet *);
static struct if_clone tun_cloner =
IF_CLONE_INITIALIZER("tun", tun_clone_create, tun_clone_destroy);
static void tunattach0(struct tun_softc *);
static void tuninit(struct tun_softc *);
static void tun_i_softintr(void *);
static void tun_o_softintr(void *);
#ifdef ALTQ
static void tunstart(struct ifnet *);
#endif
static struct tun_softc *tun_find_unit(dev_t);
static struct tun_softc *tun_find_zunit(int);
static dev_type_open(tunopen);
static dev_type_close(tunclose);
static dev_type_read(tunread);
static dev_type_write(tunwrite);
static dev_type_ioctl(tunioctl);
static dev_type_poll(tunpoll);
static dev_type_kqfilter(tunkqfilter);
const struct cdevsw tun_cdevsw = {
tunopen, tunclose, tunread, tunwrite, tunioctl,
nostop, notty, tunpoll, nommap, tunkqfilter, D_OTHER,
};
void
tunattach(int unused)
{
simple_lock_init(&tun_softc_lock);
LIST_INIT(&tun_softc_list);
LIST_INIT(&tunz_softc_list);
if_clone_attach(&tun_cloner);
}
/*
* Find driver instance from dev_t.
* Call at splnet().
* Returns with tp locked (if found).
*/
static struct tun_softc *
tun_find_unit(dev_t dev)
{
struct tun_softc *tp;
int unit = minor(dev);
simple_lock(&tun_softc_lock);
LIST_FOREACH(tp, &tun_softc_list, tun_list)
if (unit == tp->tun_unit)
break;
if (tp)
simple_lock(&tp->tun_lock);
simple_unlock(&tun_softc_lock);
return (tp);
}
/*
* Find zombie driver instance by unit number.
* Call at splnet().
* Remove tp from list and return it unlocked (if found).
*/
static struct tun_softc *
tun_find_zunit(int unit)
{
struct tun_softc *tp;
simple_lock(&tun_softc_lock);
LIST_FOREACH(tp, &tunz_softc_list, tun_list)
if (unit == tp->tun_unit)
break;
if (tp)
LIST_REMOVE(tp, tun_list);
simple_unlock(&tun_softc_lock);
#ifdef DIAGNOSTIC
if (tp != NULL && (tp->tun_flags & (TUN_INITED|TUN_OPEN)) != TUN_OPEN)
printf("tun%d: inconsistent flags: %x\n", unit, tp->tun_flags);
#endif
return (tp);
}
static int
tun_clone_create(struct if_clone *ifc, int unit)
{
struct tun_softc *tp;
if ((tp = tun_find_zunit(unit)) == NULL) {
/* Allocate a new instance */
tp = malloc(sizeof(*tp), M_DEVBUF, M_WAITOK|M_ZERO);
tp->tun_unit = unit;
simple_lock_init(&tp->tun_lock);
selinit(&tp->tun_rsel);
selinit(&tp->tun_wsel);
} else {
/* Revive tunnel instance; clear ifp part */
(void)memset(&tp->tun_if, 0, sizeof(struct ifnet));
}
if_initname(&tp->tun_if, ifc->ifc_name, unit);
tunattach0(tp);
tp->tun_flags |= TUN_INITED;
tp->tun_osih = softint_establish(SOFTINT_CLOCK, tun_o_softintr, tp);
tp->tun_isih = softint_establish(SOFTINT_CLOCK, tun_i_softintr, tp);
simple_lock(&tun_softc_lock);
LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list);
simple_unlock(&tun_softc_lock);
return (0);
}
static void
tunattach0(struct tun_softc *tp)
{
struct ifnet *ifp;
ifp = &tp->tun_if;
ifp->if_softc = tp;
ifp->if_mtu = TUNMTU;
ifp->if_ioctl = tun_ioctl;
ifp->if_output = tun_output;
#ifdef ALTQ
ifp->if_start = tunstart;
#endif
ifp->if_flags = IFF_POINTOPOINT;
ifp->if_type = IFT_TUNNEL;
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;
ifp->if_ibytes = 0;
ifp->if_obytes = 0;
ifp->if_dlt = DLT_NULL;
IFQ_SET_READY(&ifp->if_snd);
if_attach(ifp);
if_alloc_sadl(ifp);
#if NBPFILTER > 0
bpfattach(ifp, DLT_NULL, sizeof(uint32_t));
#endif
}
static int
tun_clone_destroy(struct ifnet *ifp)
{
struct tun_softc *tp = (void *)ifp;
int s, zombie = 0;
s = splnet();
simple_lock(&tun_softc_lock);
simple_lock(&tp->tun_lock);
LIST_REMOVE(tp, tun_list);
if (tp->tun_flags & TUN_OPEN) {
/* Hang on to storage until last close */
zombie = 1;
tp->tun_flags &= ~TUN_INITED;
LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list);
}
simple_unlock(&tun_softc_lock);
IF_PURGE(&ifp->if_snd);
ifp->if_flags &= ~IFF_RUNNING;
if (tp->tun_flags & TUN_RWAIT) {
tp->tun_flags &= ~TUN_RWAIT;
wakeup((void *)tp);
}
selnotify(&tp->tun_rsel, 0, 0);
simple_unlock(&tp->tun_lock);
splx(s);
if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid)
fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL);
#if NBPFILTER > 0
bpfdetach(ifp);
#endif
if_detach(ifp);
if (!zombie) {
seldestroy(&tp->tun_rsel);
seldestroy(&tp->tun_wsel);
softint_disestablish(tp->tun_osih);
softint_disestablish(tp->tun_isih);
free(tp, M_DEVBUF);
}
return (0);
}
/*
* tunnel open - must be superuser & the device must be
* configured in
*/
static int
tunopen(dev_t dev, int flag, int mode, struct lwp *l)
{
struct ifnet *ifp;
struct tun_softc *tp;
int s, error;
if ((error = kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER,
NULL)) != 0)
return (error);
s = splnet();
tp = tun_find_unit(dev);
if (tp == NULL) {
(void)tun_clone_create(&tun_cloner, minor(dev));
tp = tun_find_unit(dev);
if (tp == NULL) {
error = ENXIO;
goto out_nolock;
}
}
if (tp->tun_flags & TUN_OPEN) {
error = EBUSY;
goto out;
}
ifp = &tp->tun_if;
tp->tun_flags |= TUN_OPEN;
TUNDEBUG("%s: open\n", ifp->if_xname);
out:
simple_unlock(&tp->tun_lock);
out_nolock:
splx(s);
return (error);
}
/*
* tunclose - close the device - mark i/f down & delete
* routing info
*/
int
tunclose(dev_t dev, int flag, int mode,
struct lwp *l)
{
int s;
struct tun_softc *tp;
struct ifnet *ifp;
s = splnet();
if ((tp = tun_find_zunit(minor(dev))) != NULL) {
/* interface was "destroyed" before the close */
seldestroy(&tp->tun_rsel);
seldestroy(&tp->tun_wsel);
softint_disestablish(tp->tun_osih);
softint_disestablish(tp->tun_isih);
free(tp, M_DEVBUF);
goto out_nolock;
}
if ((tp = tun_find_unit(dev)) == NULL)
goto out_nolock;
ifp = &tp->tun_if;
tp->tun_flags &= ~TUN_OPEN;
/*
* junk all pending output
*/
IFQ_PURGE(&ifp->if_snd);
if (ifp->if_flags & IFF_UP) {
if_down(ifp);
if (ifp->if_flags & IFF_RUNNING) {
/* find internet addresses and delete routes */
struct ifaddr *ifa;
IFADDR_FOREACH(ifa, ifp) {
#if defined(INET) || defined(INET6)
if (ifa->ifa_addr->sa_family == AF_INET ||
ifa->ifa_addr->sa_family == AF_INET6) {
rtinit(ifa, (int)RTM_DELETE,
tp->tun_flags & TUN_DSTADDR
? RTF_HOST
: 0);
}
#endif
}
}
}
tp->tun_pgid = 0;
selnotify(&tp->tun_rsel, 0, 0);
TUNDEBUG ("%s: closed\n", ifp->if_xname);
simple_unlock(&tp->tun_lock);
out_nolock:
splx(s);
return (0);
}
/*
* Call at splnet() with tp locked.
*/
static void
tuninit(struct tun_softc *tp)
{
struct ifnet *ifp = &tp->tun_if;
struct ifaddr *ifa;
TUNDEBUG("%s: tuninit\n", ifp->if_xname);
ifp->if_flags |= IFF_UP | IFF_RUNNING;
tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR);
IFADDR_FOREACH(ifa, ifp) {
#ifdef INET
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;
}
}
#endif
#ifdef INET6
if (ifa->ifa_addr->sa_family == AF_INET6) {
struct sockaddr_in6 *sin;
sin = (struct sockaddr_in6 *)ifa->ifa_addr;
if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr))
tp->tun_flags |= TUN_IASET;
if (ifp->if_flags & IFF_POINTOPOINT) {
sin = (struct sockaddr_in6 *)ifa->ifa_dstaddr;
if (sin &&
!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr))
tp->tun_flags |= TUN_DSTADDR;
} else
tp->tun_flags &= ~TUN_DSTADDR;
}
#endif /* INET6 */
}
return;
}
/*
* Process an ioctl request.
*/
static int
tun_ioctl(struct ifnet *ifp, u_long cmd, void *data)
{
int error = 0, s;
struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc);
struct ifreq *ifr = data;
s = splnet();
simple_lock(&tp->tun_lock);
switch (cmd) {
case SIOCSIFADDR:
tuninit(tp);
TUNDEBUG("%s: address set\n", ifp->if_xname);
break;
case SIOCSIFDSTADDR:
tuninit(tp);
TUNDEBUG("%s: destination address set\n", ifp->if_xname);
break;
case SIOCSIFBRDADDR:
TUNDEBUG("%s: broadcast address set\n", ifp->if_xname);
break;
case SIOCSIFMTU:
if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) {
error = EINVAL;
break;
}
TUNDEBUG("%s: interface mtu set\n", ifp->if_xname);
if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
error = 0;
break;
case SIOCADDMULTI:
case SIOCDELMULTI:
if (ifr == NULL) {
error = EAFNOSUPPORT; /* XXX */
break;
}
switch (ifreq_getaddr(cmd, ifr)->sa_family) {
#ifdef INET
case AF_INET:
break;
#endif
#ifdef INET6
case AF_INET6:
break;
#endif
default:
error = EAFNOSUPPORT;
break;
}
break;
case SIOCSIFFLAGS:
break;
default:
error = EINVAL;
}
simple_unlock(&tp->tun_lock);
splx(s);
return (error);
}
/*
* tun_output - queue packets from higher level ready to put out.
*/
static int
tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
struct rtentry *rt)
{
struct tun_softc *tp = ifp->if_softc;
int s;
int error;
#if defined(INET) || defined(INET6)
int mlen;
uint32_t *af;
#endif
ALTQ_DECL(struct altq_pktattr pktattr;)
s = splnet();
simple_lock(&tp->tun_lock);
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);
error = EHOSTDOWN;
goto out;
}
/*
* if the queueing discipline needs packet classification,
* do it before prepending link headers.
*/
IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr);
#if NBPFILTER > 0
if (ifp->if_bpf)
bpf_mtap_af(ifp->if_bpf, dst->sa_family, m0);
#endif
switch(dst->sa_family) {
#ifdef INET6
case AF_INET6:
#endif
#ifdef INET
case AF_INET:
#endif
#if defined(INET) || defined(INET6)
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);
error = ENOBUFS;
goto out;
}
bcopy(dst, mtod(m0, char *), dst->sa_len);
}
if (tp->tun_flags & TUN_IFHEAD) {
/* Prepend the address family */
M_PREPEND(m0, sizeof(*af), M_DONTWAIT);
if (m0 == NULL) {
IF_DROP(&ifp->if_snd);
error = ENOBUFS;
goto out;
}
af = mtod(m0,uint32_t *);
*af = htonl(dst->sa_family);
} else {
#ifdef INET
if (dst->sa_family != AF_INET)
#endif
{
m_freem(m0);
error = EAFNOSUPPORT;
goto out;
}
}
/* FALLTHROUGH */
case AF_UNSPEC:
IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error);
if (error) {
ifp->if_collisions++;
error = EAFNOSUPPORT;
goto out;
}
mlen = m0->m_pkthdr.len;
ifp->if_opackets++;
ifp->if_obytes += mlen;
break;
#endif
default:
m_freem(m0);
error = EAFNOSUPPORT;
goto out;
}
if (tp->tun_flags & TUN_RWAIT) {
tp->tun_flags &= ~TUN_RWAIT;
wakeup((void *)tp);
}
if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid)
softint_schedule(tp->tun_isih);
selnotify(&tp->tun_rsel, 0, 0);
out:
simple_unlock(&tp->tun_lock);
splx(s);
return (0);
}
static void
tun_i_softintr(void *cookie)
{
struct tun_softc *tp = cookie;
if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid)
fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM,
NULL);
}
static void
tun_o_softintr(void *cookie)
{
struct tun_softc *tp = cookie;
if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid)
fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM,
NULL);
}
/*
* the cdevsw interface is now pretty minimal.
*/
int
tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
struct tun_softc *tp;
int s, error = 0;
s = splnet();
tp = tun_find_unit(dev);
/* interface was "destroyed" already */
if (tp == NULL) {
error = ENXIO;
goto out_nolock;
}
switch (cmd) {
case TUNSDEBUG:
tundebug = *(int *)data;
break;
case TUNGDEBUG:
*(int *)data = tundebug;
break;
case TUNSIFMODE:
switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) {
case IFF_POINTOPOINT:
case IFF_BROADCAST:
if (tp->tun_if.if_flags & IFF_UP) {
error = EBUSY;
goto out;
}
tp->tun_if.if_flags &=
~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
tp->tun_if.if_flags |= *(int *)data;
break;
default:
error = EINVAL;
goto out;
}
break;
case TUNSLMODE:
if (*(int *)data) {
tp->tun_flags |= TUN_PREPADDR;
tp->tun_flags &= ~TUN_IFHEAD;
} else
tp->tun_flags &= ~TUN_PREPADDR;
break;
case TUNSIFHEAD:
if (*(int *)data) {
tp->tun_flags |= TUN_IFHEAD;
tp->tun_flags &= ~TUN_PREPADDR;
} else
tp->tun_flags &= ~TUN_IFHEAD;
break;
case TUNGIFHEAD:
*(int *)data = (tp->tun_flags & TUN_IFHEAD);
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:
if (tp->tun_if.if_snd.ifq_head)
*(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len;
else
*(int *)data = 0;
break;
case TIOCSPGRP:
case FIOSETOWN:
error = fsetown(&tp->tun_pgid, cmd, data);
break;
case TIOCGPGRP:
case FIOGETOWN:
error = fgetown(tp->tun_pgid, cmd, data);
break;
default:
error = ENOTTY;
}
out:
simple_unlock(&tp->tun_lock);
out_nolock:
splx(s);
return (error);
}
/*
* 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_t dev, struct uio *uio, int ioflag)
{
struct tun_softc *tp;
struct ifnet *ifp;
struct mbuf *m, *m0;
int error = 0, len, s, index;
s = splnet();
tp = tun_find_unit(dev);
/* interface was "destroyed" already */
if (tp == NULL) {
error = ENXIO;
goto out_nolock;
}
index = tp->tun_if.if_index;
ifp = &tp->tun_if;
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);
error = EHOSTDOWN;
goto out;
}
tp->tun_flags &= ~TUN_RWAIT;
do {
IFQ_DEQUEUE(&ifp->if_snd, m0);
if (m0 == 0) {
if (tp->tun_flags & TUN_NBIO) {
error = EWOULDBLOCK;
goto out;
}
tp->tun_flags |= TUN_RWAIT;
if (ltsleep((void *)tp, PZERO|PCATCH|PNORELOCK,
"tunread", 0, &tp->tun_lock) != 0) {
error = EINTR;
goto out_nolock;
} else {
/*
* Maybe the interface was destroyed while
* we were sleeping, so let's ensure that
* we're looking at the same (valid) tun
* interface before looping.
*/
tp = tun_find_unit(dev);
if (tp == NULL) {
error = ENXIO;
goto out_nolock;
}
if (tp->tun_if.if_index != index) {
error = ENXIO;
goto out;
}
}
}
} while (m0 == 0);
simple_unlock(&tp->tun_lock);
splx(s);
/* Copy the mbuf chain */
while (m0 && uio->uio_resid > 0 && error == 0) {
len = min(uio->uio_resid, m0->m_len);
if (len != 0)
error = uiomove(mtod(m0, void *), len, uio);
MFREE(m0, m);
m0 = m;
}
if (m0) {
TUNDEBUG("Dropping mbuf\n");
m_freem(m0);
}
if (error)
ifp->if_ierrors++;
return (error);
out:
simple_unlock(&tp->tun_lock);
out_nolock:
splx(s);
return (error);
}
/*
* the cdevsw write interface - an atomic write is a packet - or else!
*/
int
tunwrite(dev_t dev, struct uio *uio, int ioflag)
{
struct tun_softc *tp;
struct ifnet *ifp;
struct mbuf *top, **mp, *m;
struct ifqueue *ifq;
struct sockaddr dst;
int isr, error = 0, s, tlen, mlen;
uint32_t family;
s = splnet();
tp = tun_find_unit(dev);
/* interface was "destroyed" already */
if (tp == NULL) {
error = ENXIO;
goto out_nolock;
}
/* Unlock until we've got the data */
simple_unlock(&tp->tun_lock);
splx(s);
ifp = &tp->tun_if;
TUNDEBUG("%s: tunwrite\n", ifp->if_xname);
if (tp->tun_flags & TUN_PREPADDR) {
if (uio->uio_resid < sizeof(dst)) {
error = EIO;
goto out0;
}
error = uiomove((void *)&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) {
goto out0;
}
}
} else if (tp->tun_flags & TUN_IFHEAD) {
if (uio->uio_resid < sizeof(family)){
error = EIO;
goto out0;
}
error = uiomove((void *)&family, sizeof(family), uio);
dst.sa_family = ntohl(family);
} else {
#ifdef INET
dst.sa_family = AF_INET;
#endif
}
if (uio->uio_resid > TUNMTU) {
TUNDEBUG("%s: len=%lu!\n", ifp->if_xname,
(unsigned long)uio->uio_resid);
error = EIO;
goto out0;
}
switch (dst.sa_family) {
#ifdef INET
case AF_INET:
ifq = &ipintrq;
isr = NETISR_IP;
break;
#endif
#ifdef INET6
case AF_INET6:
ifq = &ip6intrq;
isr = NETISR_IPV6;
break;
#endif
default:
error = EAFNOSUPPORT;
goto out0;
}
tlen = uio->uio_resid;
/* get a header mbuf */
MGETHDR(m, M_DONTWAIT, MT_DATA);
if (m == NULL) {
error = ENOBUFS;
goto out0;
}
mlen = MHLEN;
top = NULL;
mp = ⊤
while (error == 0 && uio->uio_resid > 0) {
m->m_len = min(mlen, uio->uio_resid);
error = uiomove(mtod(m, void *), m->m_len, uio);
*mp = m;
mp = &m->m_next;
if (error == 0 && uio->uio_resid > 0) {
MGET(m, M_DONTWAIT, MT_DATA);
if (m == NULL) {
error = ENOBUFS;
break;
}
mlen = MLEN;
}
}
if (error) {
if (top != NULL)
m_freem (top);
ifp->if_ierrors++;
goto out0;
}
top->m_pkthdr.len = tlen;
top->m_pkthdr.rcvif = ifp;
#if NBPFILTER > 0
if (ifp->if_bpf)
bpf_mtap_af(ifp->if_bpf, dst.sa_family, top);
#endif
s = splnet();
simple_lock(&tp->tun_lock);
if ((tp->tun_flags & TUN_INITED) == 0) {
/* Interface was destroyed */
error = ENXIO;
goto out;
}
if (IF_QFULL(ifq)) {
IF_DROP(ifq);
ifp->if_collisions++;
m_freem(top);
error = ENOBUFS;
goto out;
}
IF_ENQUEUE(ifq, top);
ifp->if_ipackets++;
ifp->if_ibytes += tlen;
schednetisr(isr);
out:
simple_unlock(&tp->tun_lock);
out_nolock:
splx(s);
out0:
return (error);
}
#ifdef ALTQ
/*
* Start packet transmission on the interface.
* when the interface queue is rate-limited by ALTQ or TBR,
* if_start is needed to drain packets from the queue in order
* to notify readers when outgoing packets become ready.
*
* Should be called at splnet.
*/
static void
tunstart(struct ifnet *ifp)
{
struct tun_softc *tp = ifp->if_softc;
if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd))
return;
simple_lock(&tp->tun_lock);
if (!IF_IS_EMPTY(&ifp->if_snd)) {
if (tp->tun_flags & TUN_RWAIT) {
tp->tun_flags &= ~TUN_RWAIT;
wakeup((void *)tp);
}
if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid)
softint_schedule(tp->tun_osih);
selnotify(&tp->tun_rsel, 0, 0);
}
simple_unlock(&tp->tun_lock);
}
#endif /* ALTQ */
/*
* 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_t dev, int events, struct lwp *l)
{
struct tun_softc *tp;
struct ifnet *ifp;
int s, revents = 0;
s = splnet();
tp = tun_find_unit(dev);
/* interface was "destroyed" already */
if (tp == NULL)
goto out_nolock;
ifp = &tp->tun_if;
TUNDEBUG("%s: tunpoll\n", ifp->if_xname);
if (events & (POLLIN | POLLRDNORM)) {
if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
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(l, &tp->tun_rsel);
}
}
if (events & (POLLOUT | POLLWRNORM))
revents |= events & (POLLOUT | POLLWRNORM);
simple_unlock(&tp->tun_lock);
out_nolock:
splx(s);
return (revents);
}
static void
filt_tunrdetach(struct knote *kn)
{
struct tun_softc *tp = kn->kn_hook;
int s;
s = splnet();
SLIST_REMOVE(&tp->tun_rsel.sel_klist, kn, knote, kn_selnext);
splx(s);
}
static int
filt_tunread(struct knote *kn, long hint)
{
struct tun_softc *tp = kn->kn_hook;
struct ifnet *ifp = &tp->tun_if;
struct mbuf *m;
int s;
s = splnet();
IF_POLL(&ifp->if_snd, m);
if (m == NULL) {
splx(s);
return (0);
}
for (kn->kn_data = 0; m != NULL; m = m->m_next)
kn->kn_data += m->m_len;
splx(s);
return (1);
}
static const struct filterops tunread_filtops =
{ 1, NULL, filt_tunrdetach, filt_tunread };
static const struct filterops tun_seltrue_filtops =
{ 1, NULL, filt_tunrdetach, filt_seltrue };
int
tunkqfilter(dev_t dev, struct knote *kn)
{
struct tun_softc *tp;
struct klist *klist;
int rv = 0, s;
s = splnet();
tp = tun_find_unit(dev);
if (tp == NULL)
goto out_nolock;
switch (kn->kn_filter) {
case EVFILT_READ:
klist = &tp->tun_rsel.sel_klist;
kn->kn_fop = &tunread_filtops;
break;
case EVFILT_WRITE:
klist = &tp->tun_rsel.sel_klist;
kn->kn_fop = &tun_seltrue_filtops;
break;
default:
rv = EINVAL;
goto out;
}
kn->kn_hook = tp;
SLIST_INSERT_HEAD(klist, kn, kn_selnext);
out:
simple_unlock(&tp->tun_lock);
out_nolock:
splx(s);
return (rv);
}