freebsd-nq/sys/net/if_tap.c
Maksim Yevmenkin 75ae257016 Change m_uiotombuf so it will accept offset at which data should be copied
to the mbuf. Offset cannot exceed MHLEN bytes. This is currently used to
fix Ethernet header alignment problem on alpha and sparc64. Also change all
users of m_uiotombuf to pass proper offset.

Reviewed by:	jmg, sam
Tested by:	Sten Spans "sten AT blinkenlights DOT nl"
MFC after:	1 week
2005-05-04 18:55:03 +00:00

887 lines
19 KiB
C

/*-
* Copyright (C) 1999-2000 by Maksim Yevmenkin <m_evmenkin@yahoo.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* BASED ON:
* -------------------------------------------------------------------------
*
* Copyright (c) 1988, Julian Onions <jpo@cs.nott.ac.uk>
* Nottingham University 1987.
*/
/*
* $FreeBSD$
* $Id: if_tap.c,v 0.21 2000/07/23 21:46:02 max Exp $
*/
#include "opt_inet.h"
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/filio.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/poll.h>
#include <sys/proc.h>
#include <sys/selinfo.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/ttycom.h>
#include <sys/uio.h>
#include <sys/queue.h>
#include <net/bpf.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <net/route.h>
#include <netinet/in.h>
#include <net/if_tapvar.h>
#include <net/if_tap.h>
#define CDEV_NAME "tap"
#define TAPDEBUG if (tapdebug) printf
#define TAP "tap"
#define VMNET "vmnet"
#define TAPMAXUNIT 0x7fff
#define VMNET_DEV_MASK CLONE_FLAG0
/* module */
static int tapmodevent(module_t, int, void *);
/* device */
static void tapclone(void *, char *, int, struct cdev **);
static void tapcreate(struct cdev *);
/* network interface */
static void tapifstart(struct ifnet *);
static int tapifioctl(struct ifnet *, u_long, caddr_t);
static void tapifinit(void *);
/* character device */
static d_open_t tapopen;
static d_close_t tapclose;
static d_read_t tapread;
static d_write_t tapwrite;
static d_ioctl_t tapioctl;
static d_poll_t tappoll;
static struct cdevsw tap_cdevsw = {
.d_version = D_VERSION,
.d_flags = D_PSEUDO | D_NEEDGIANT,
.d_open = tapopen,
.d_close = tapclose,
.d_read = tapread,
.d_write = tapwrite,
.d_ioctl = tapioctl,
.d_poll = tappoll,
.d_name = CDEV_NAME,
};
/*
* All global variables in if_tap.c are locked with tapmtx, with the
* exception of tapdebug, which is accessed unlocked; tapclones is
* static at runtime.
*/
static struct mtx tapmtx;
static int tapdebug = 0; /* debug flag */
static int tapuopen = 0; /* allow user open() */
static SLIST_HEAD(, tap_softc) taphead; /* first device */
static struct clonedevs *tapclones;
MALLOC_DECLARE(M_TAP);
MALLOC_DEFINE(M_TAP, CDEV_NAME, "Ethernet tunnel interface");
SYSCTL_INT(_debug, OID_AUTO, if_tap_debug, CTLFLAG_RW, &tapdebug, 0, "");
SYSCTL_DECL(_net_link);
SYSCTL_NODE(_net_link, OID_AUTO, tap, CTLFLAG_RW, 0,
"Ethernet tunnel software network interface");
SYSCTL_INT(_net_link_tap, OID_AUTO, user_open, CTLFLAG_RW, &tapuopen, 0,
"Allow user to open /dev/tap (based on node permissions)");
SYSCTL_INT(_net_link_tap, OID_AUTO, debug, CTLFLAG_RW, &tapdebug, 0, "");
DEV_MODULE(if_tap, tapmodevent, NULL);
/*
* tapmodevent
*
* module event handler
*/
static int
tapmodevent(mod, type, data)
module_t mod;
int type;
void *data;
{
static eventhandler_tag eh_tag = NULL;
struct tap_softc *tp = NULL;
struct ifnet *ifp = NULL;
int s;
switch (type) {
case MOD_LOAD:
/* intitialize device */
mtx_init(&tapmtx, "tapmtx", NULL, MTX_DEF);
SLIST_INIT(&taphead);
clone_setup(&tapclones);
eh_tag = EVENTHANDLER_REGISTER(dev_clone, tapclone, 0, 1000);
if (eh_tag == NULL) {
clone_cleanup(&tapclones);
mtx_destroy(&tapmtx);
return (ENOMEM);
}
return (0);
case MOD_UNLOAD:
/*
* The EBUSY algorithm here can't quite atomically
* guarantee that this is race-free since we have to
* release the tap mtx to deregister the clone handler.
*/
mtx_lock(&tapmtx);
SLIST_FOREACH(tp, &taphead, tap_next) {
mtx_lock(&tp->tap_mtx);
if (tp->tap_flags & TAP_OPEN) {
mtx_unlock(&tp->tap_mtx);
mtx_unlock(&tapmtx);
return (EBUSY);
}
mtx_unlock(&tp->tap_mtx);
}
mtx_unlock(&tapmtx);
EVENTHANDLER_DEREGISTER(dev_clone, eh_tag);
mtx_lock(&tapmtx);
while ((tp = SLIST_FIRST(&taphead)) != NULL) {
SLIST_REMOVE_HEAD(&taphead, tap_next);
mtx_unlock(&tapmtx);
ifp = &tp->tap_if;
TAPDEBUG("detaching %s\n", ifp->if_xname);
/* Unlocked read. */
KASSERT(!(tp->tap_flags & TAP_OPEN),
("%s flags is out of sync", ifp->if_xname));
destroy_dev(tp->tap_dev);
s = splimp();
ether_ifdetach(ifp);
splx(s);
mtx_destroy(&tp->tap_mtx);
free(tp, M_TAP);
mtx_lock(&tapmtx);
}
mtx_unlock(&tapmtx);
clone_cleanup(&tapclones);
mtx_destroy(&tapmtx);
break;
default:
return (EOPNOTSUPP);
}
return (0);
} /* tapmodevent */
/*
* DEVFS handler
*
* We need to support two kind of devices - tap and vmnet
*/
static void
tapclone(arg, name, namelen, dev)
void *arg;
char *name;
int namelen;
struct cdev **dev;
{
u_int extra;
int i, unit;
char *device_name = name;
if (*dev != NULL)
return;
device_name = TAP;
extra = 0;
if (strcmp(name, TAP) == 0) {
unit = -1;
} else if (strcmp(name, VMNET) == 0) {
device_name = VMNET;
extra = VMNET_DEV_MASK;
unit = -1;
} else if (dev_stdclone(name, NULL, device_name, &unit) != 1) {
device_name = VMNET;
extra = VMNET_DEV_MASK;
if (dev_stdclone(name, NULL, device_name, &unit) != 1)
return;
}
/* find any existing device, or allocate new unit number */
i = clone_create(&tapclones, &tap_cdevsw, &unit, dev, extra);
if (i) {
*dev = make_dev(&tap_cdevsw, unit2minor(unit | extra),
UID_ROOT, GID_WHEEL, 0600, "%s%d", device_name, unit);
if (*dev != NULL) {
dev_ref(*dev);
(*dev)->si_flags |= SI_CHEAPCLONE;
}
}
} /* tapclone */
/*
* tapcreate
*
* to create interface
*/
static void
tapcreate(dev)
struct cdev *dev;
{
struct ifnet *ifp = NULL;
struct tap_softc *tp = NULL;
unsigned short macaddr_hi;
int unit, s;
char *name = NULL;
dev->si_flags &= ~SI_CHEAPCLONE;
/* allocate driver storage and create device */
MALLOC(tp, struct tap_softc *, sizeof(*tp), M_TAP, M_WAITOK | M_ZERO);
mtx_init(&tp->tap_mtx, "tap_mtx", NULL, MTX_DEF);
mtx_lock(&tapmtx);
SLIST_INSERT_HEAD(&taphead, tp, tap_next);
mtx_unlock(&tapmtx);
unit = dev2unit(dev);
/* select device: tap or vmnet */
if (unit & VMNET_DEV_MASK) {
name = VMNET;
tp->tap_flags |= TAP_VMNET;
} else
name = TAP;
unit &= TAPMAXUNIT;
TAPDEBUG("tapcreate(%s%d). minor = %#x\n", name, unit, minor(dev));
/* generate fake MAC address: 00 bd xx xx xx unit_no */
macaddr_hi = htons(0x00bd);
bcopy(&macaddr_hi, &tp->arpcom.ac_enaddr[0], sizeof(short));
bcopy(&ticks, &tp->arpcom.ac_enaddr[2], sizeof(long));
tp->arpcom.ac_enaddr[5] = (u_char)unit;
/* fill the rest and attach interface */
ifp = &tp->tap_if;
ifp->if_softc = tp;
if_initname(ifp, name, unit);
ifp->if_init = tapifinit;
ifp->if_start = tapifstart;
ifp->if_ioctl = tapifioctl;
ifp->if_mtu = ETHERMTU;
ifp->if_flags = (IFF_BROADCAST|IFF_SIMPLEX|IFF_MULTICAST);
ifp->if_snd.ifq_maxlen = ifqmaxlen;
dev->si_drv1 = tp;
tp->tap_dev = dev;
s = splimp();
ether_ifattach(ifp, tp->arpcom.ac_enaddr);
splx(s);
mtx_lock(&tp->tap_mtx);
tp->tap_flags |= TAP_INITED;
mtx_unlock(&tp->tap_mtx);
TAPDEBUG("interface %s is created. minor = %#x\n",
ifp->if_xname, minor(dev));
} /* tapcreate */
/*
* tapopen
*
* to open tunnel. must be superuser
*/
static int
tapopen(dev, flag, mode, td)
struct cdev *dev;
int flag;
int mode;
struct thread *td;
{
struct tap_softc *tp = NULL;
struct ifnet *ifp = NULL;
int s;
if (tapuopen == 0 && suser(td) != 0)
return (EPERM);
if ((dev2unit(dev) & CLONE_UNITMASK) > TAPMAXUNIT)
return (ENXIO);
/*
* XXXRW: Non-atomic test-and-set of si_drv1. Currently protected
* by Giant, but the race actually exists under memory pressure as
* well even when running with Giant, as malloc() may sleep.
*/
tp = dev->si_drv1;
if (tp == NULL) {
tapcreate(dev);
tp = dev->si_drv1;
}
mtx_lock(&tp->tap_mtx);
if (tp->tap_flags & TAP_OPEN) {
mtx_unlock(&tp->tap_mtx);
return (EBUSY);
}
bcopy(tp->arpcom.ac_enaddr, tp->ether_addr, sizeof(tp->ether_addr));
tp->tap_pid = td->td_proc->p_pid;
tp->tap_flags |= TAP_OPEN;
ifp = &tp->tap_if;
mtx_unlock(&tp->tap_mtx);
s = splimp();
ifp->if_flags |= IFF_RUNNING;
ifp->if_flags &= ~IFF_OACTIVE;
splx(s);
TAPDEBUG("%s is open. minor = %#x\n", ifp->if_xname, minor(dev));
return (0);
} /* tapopen */
/*
* tapclose
*
* close the device - mark i/f down & delete routing info
*/
static int
tapclose(dev, foo, bar, td)
struct cdev *dev;
int foo;
int bar;
struct thread *td;
{
struct tap_softc *tp = dev->si_drv1;
struct ifnet *ifp = &tp->tap_if;
int s;
/* junk all pending output */
IF_DRAIN(&ifp->if_snd);
/*
* do not bring the interface down, and do not anything with
* interface, if we are in VMnet mode. just close the device.
*/
mtx_lock(&tp->tap_mtx);
if (((tp->tap_flags & TAP_VMNET) == 0) && (ifp->if_flags & IFF_UP)) {
mtx_unlock(&tp->tap_mtx);
s = splimp();
if_down(ifp);
if (ifp->if_flags & IFF_RUNNING) {
/* find internet addresses and delete routes */
struct ifaddr *ifa = NULL;
/* In desparate need of ifaddr locking. */
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family == AF_INET) {
rtinit(ifa, (int)RTM_DELETE, 0);
/* remove address from interface */
bzero(ifa->ifa_addr,
sizeof(*(ifa->ifa_addr)));
bzero(ifa->ifa_dstaddr,
sizeof(*(ifa->ifa_dstaddr)));
bzero(ifa->ifa_netmask,
sizeof(*(ifa->ifa_netmask)));
}
}
ifp->if_flags &= ~IFF_RUNNING;
}
splx(s);
} else
mtx_unlock(&tp->tap_mtx);
funsetown(&tp->tap_sigio);
selwakeuppri(&tp->tap_rsel, PZERO+1);
mtx_lock(&tp->tap_mtx);
tp->tap_flags &= ~TAP_OPEN;
tp->tap_pid = 0;
mtx_unlock(&tp->tap_mtx);
TAPDEBUG("%s is closed. minor = %#x\n",
ifp->if_xname, minor(dev));
return (0);
} /* tapclose */
/*
* tapifinit
*
* network interface initialization function
*/
static void
tapifinit(xtp)
void *xtp;
{
struct tap_softc *tp = (struct tap_softc *)xtp;
struct ifnet *ifp = &tp->tap_if;
TAPDEBUG("initializing %s\n", ifp->if_xname);
ifp->if_flags |= IFF_RUNNING;
ifp->if_flags &= ~IFF_OACTIVE;
/* attempt to start output */
tapifstart(ifp);
} /* tapifinit */
/*
* tapifioctl
*
* Process an ioctl request on network interface
*/
static int
tapifioctl(ifp, cmd, data)
struct ifnet *ifp;
u_long cmd;
caddr_t data;
{
struct tap_softc *tp = (struct tap_softc *)(ifp->if_softc);
struct ifstat *ifs = NULL;
int s, dummy;
switch (cmd) {
case SIOCSIFFLAGS: /* XXX -- just like vmnet does */
case SIOCADDMULTI:
case SIOCDELMULTI:
break;
case SIOCGIFSTATUS:
s = splimp();
ifs = (struct ifstat *)data;
dummy = strlen(ifs->ascii);
mtx_lock(&tp->tap_mtx);
if (tp->tap_pid != 0 && dummy < sizeof(ifs->ascii))
snprintf(ifs->ascii + dummy,
sizeof(ifs->ascii) - dummy,
"\tOpened by PID %d\n", tp->tap_pid);
mtx_unlock(&tp->tap_mtx);
splx(s);
break;
default:
s = splimp();
dummy = ether_ioctl(ifp, cmd, data);
splx(s);
return (dummy);
}
return (0);
} /* tapifioctl */
/*
* tapifstart
*
* queue packets from higher level ready to put out
*/
static void
tapifstart(ifp)
struct ifnet *ifp;
{
struct tap_softc *tp = ifp->if_softc;
int s;
TAPDEBUG("%s starting\n", ifp->if_xname);
/*
* do not junk pending output if we are in VMnet mode.
* XXX: can this do any harm because of queue overflow?
*/
mtx_lock(&tp->tap_mtx);
if (((tp->tap_flags & TAP_VMNET) == 0) &&
((tp->tap_flags & TAP_READY) != TAP_READY)) {
struct mbuf *m = NULL;
mtx_unlock(&tp->tap_mtx);
/* Unlocked read. */
TAPDEBUG("%s not ready, tap_flags = 0x%x\n", ifp->if_xname,
tp->tap_flags);
s = splimp();
do {
IF_DEQUEUE(&ifp->if_snd, m);
if (m != NULL)
m_freem(m);
ifp->if_oerrors ++;
} while (m != NULL);
splx(s);
return;
}
mtx_unlock(&tp->tap_mtx);
s = splimp();
ifp->if_flags |= IFF_OACTIVE;
if (ifp->if_snd.ifq_len != 0) {
mtx_lock(&tp->tap_mtx);
if (tp->tap_flags & TAP_RWAIT) {
tp->tap_flags &= ~TAP_RWAIT;
wakeup(tp);
}
if ((tp->tap_flags & TAP_ASYNC) && (tp->tap_sigio != NULL)) {
mtx_unlock(&tp->tap_mtx);
pgsigio(&tp->tap_sigio, SIGIO, 0);
} else
mtx_unlock(&tp->tap_mtx);
selwakeuppri(&tp->tap_rsel, PZERO+1);
ifp->if_opackets ++; /* obytes are counted in ether_output */
}
ifp->if_flags &= ~IFF_OACTIVE;
splx(s);
} /* tapifstart */
/*
* tapioctl
*
* the cdevsw interface is now pretty minimal
*/
static int
tapioctl(dev, cmd, data, flag, td)
struct cdev *dev;
u_long cmd;
caddr_t data;
int flag;
struct thread *td;
{
struct tap_softc *tp = dev->si_drv1;
struct ifnet *ifp = &tp->tap_if;
struct tapinfo *tapp = NULL;
int s;
int f;
switch (cmd) {
case TAPSIFINFO:
s = splimp();
tapp = (struct tapinfo *)data;
ifp->if_mtu = tapp->mtu;
ifp->if_type = tapp->type;
ifp->if_baudrate = tapp->baudrate;
splx(s);
break;
case TAPGIFINFO:
tapp = (struct tapinfo *)data;
tapp->mtu = ifp->if_mtu;
tapp->type = ifp->if_type;
tapp->baudrate = ifp->if_baudrate;
break;
case TAPSDEBUG:
tapdebug = *(int *)data;
break;
case TAPGDEBUG:
*(int *)data = tapdebug;
break;
case FIONBIO:
break;
case FIOASYNC:
s = splimp();
mtx_lock(&tp->tap_mtx);
if (*(int *)data)
tp->tap_flags |= TAP_ASYNC;
else
tp->tap_flags &= ~TAP_ASYNC;
mtx_unlock(&tp->tap_mtx);
splx(s);
break;
case FIONREAD:
s = splimp();
if (ifp->if_snd.ifq_head) {
struct mbuf *mb = ifp->if_snd.ifq_head;
for(*(int *)data = 0;mb != NULL;mb = mb->m_next)
*(int *)data += mb->m_len;
} else
*(int *)data = 0;
splx(s);
break;
case FIOSETOWN:
return (fsetown(*(int *)data, &tp->tap_sigio));
case FIOGETOWN:
*(int *)data = fgetown(&tp->tap_sigio);
return (0);
/* this is deprecated, FIOSETOWN should be used instead */
case TIOCSPGRP:
return (fsetown(-(*(int *)data), &tp->tap_sigio));
/* this is deprecated, FIOGETOWN should be used instead */
case TIOCGPGRP:
*(int *)data = -fgetown(&tp->tap_sigio);
return (0);
/* VMware/VMnet port ioctl's */
case SIOCGIFFLAGS: /* get ifnet flags */
bcopy(&ifp->if_flags, data, sizeof(ifp->if_flags));
break;
case VMIO_SIOCSIFFLAGS: /* VMware/VMnet SIOCSIFFLAGS */
f = *(int *)data;
f &= 0x0fff;
f &= ~IFF_CANTCHANGE;
f |= IFF_UP;
s = splimp();
ifp->if_flags = f | (ifp->if_flags & IFF_CANTCHANGE);
splx(s);
break;
case OSIOCGIFADDR: /* get MAC address of the remote side */
case SIOCGIFADDR:
mtx_lock(&tp->tap_mtx);
bcopy(tp->ether_addr, data, sizeof(tp->ether_addr));
mtx_unlock(&tp->tap_mtx);
break;
case SIOCSIFADDR: /* set MAC address of the remote side */
mtx_lock(&tp->tap_mtx);
bcopy(data, tp->ether_addr, sizeof(tp->ether_addr));
mtx_unlock(&tp->tap_mtx);
break;
default:
return (ENOTTY);
}
return (0);
} /* tapioctl */
/*
* tapread
*
* the cdevsw read interface - reads a packet at a time, or at
* least as much of a packet as can be read
*/
static int
tapread(dev, uio, flag)
struct cdev *dev;
struct uio *uio;
int flag;
{
struct tap_softc *tp = dev->si_drv1;
struct ifnet *ifp = &tp->tap_if;
struct mbuf *m = NULL;
int error = 0, len, s;
TAPDEBUG("%s reading, minor = %#x\n", ifp->if_xname, minor(dev));
mtx_lock(&tp->tap_mtx);
if ((tp->tap_flags & TAP_READY) != TAP_READY) {
mtx_unlock(&tp->tap_mtx);
/* Unlocked read. */
TAPDEBUG("%s not ready. minor = %#x, tap_flags = 0x%x\n",
ifp->if_xname, minor(dev), tp->tap_flags);
return (EHOSTDOWN);
}
tp->tap_flags &= ~TAP_RWAIT;
mtx_unlock(&tp->tap_mtx);
/* sleep until we get a packet */
do {
s = splimp();
IF_DEQUEUE(&ifp->if_snd, m);
splx(s);
if (m == NULL) {
if (flag & O_NONBLOCK)
return (EWOULDBLOCK);
mtx_lock(&tp->tap_mtx);
tp->tap_flags |= TAP_RWAIT;
mtx_unlock(&tp->tap_mtx);
error = tsleep(tp,PCATCH|(PZERO+1),"taprd",0);
if (error)
return (error);
}
} while (m == NULL);
/* feed packet to bpf */
BPF_MTAP(ifp, m);
/* xfer packet to user space */
while ((m != NULL) && (uio->uio_resid > 0) && (error == 0)) {
len = min(uio->uio_resid, m->m_len);
if (len == 0)
break;
error = uiomove(mtod(m, void *), len, uio);
m = m_free(m);
}
if (m != NULL) {
TAPDEBUG("%s dropping mbuf, minor = %#x\n", ifp->if_xname,
minor(dev));
m_freem(m);
}
return (error);
} /* tapread */
/*
* tapwrite
*
* the cdevsw write interface - an atomic write is a packet - or else!
*/
static int
tapwrite(dev, uio, flag)
struct cdev *dev;
struct uio *uio;
int flag;
{
struct tap_softc *tp = dev->si_drv1;
struct ifnet *ifp = &tp->tap_if;
struct mbuf *m;
int error = 0;
TAPDEBUG("%s writting, minor = %#x\n",
ifp->if_xname, minor(dev));
if (uio->uio_resid == 0)
return (0);
if ((uio->uio_resid < 0) || (uio->uio_resid > TAPMRU)) {
TAPDEBUG("%s invalid packet len = %d, minor = %#x\n",
ifp->if_xname, uio->uio_resid, minor(dev));
return (EIO);
}
if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, ETHER_ALIGN)) == NULL) {
ifp->if_ierrors ++;
return (error);
}
m->m_pkthdr.rcvif = ifp;
/* Pass packet up to parent. */
(*ifp->if_input)(ifp, m);
ifp->if_ipackets ++; /* ibytes are counted in parent */
return (0);
} /* tapwrite */
/*
* tappoll
*
* 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
tappoll(dev, events, td)
struct cdev *dev;
int events;
struct thread *td;
{
struct tap_softc *tp = dev->si_drv1;
struct ifnet *ifp = &tp->tap_if;
int s, revents = 0;
TAPDEBUG("%s polling, minor = %#x\n",
ifp->if_xname, minor(dev));
s = splimp();
if (events & (POLLIN | POLLRDNORM)) {
if (ifp->if_snd.ifq_len > 0) {
TAPDEBUG("%s have data in queue. len = %d, " \
"minor = %#x\n", ifp->if_xname,
ifp->if_snd.ifq_len, minor(dev));
revents |= (events & (POLLIN | POLLRDNORM));
} else {
TAPDEBUG("%s waiting for data, minor = %#x\n",
ifp->if_xname, minor(dev));
selrecord(td, &tp->tap_rsel);
}
}
if (events & (POLLOUT | POLLWRNORM))
revents |= (events & (POLLOUT | POLLWRNORM));
splx(s);
return (revents);
} /* tappoll */