 @@ -1,1412 +1,1412 @@
-/*	$NetBSD: if_tap.c,v 1.57 2009/04/11 23:05:26 christos Exp $	*/
+/*	$NetBSD: if_tap.c,v 1.58 2009/07/23 17:53:17 plunky Exp $	*/
 /*
  *  Copyright (c) 2003, 2004, 2008, 2009 The NetBSD Foundation.
  *  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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
  */
 /*
  * tap(4) is a virtual Ethernet interface.  It appears as a real Ethernet
  * device to the system, but can also be accessed by userland through a
  * character device interface, which allows reading and injecting frames.
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_tap.c,v 1.57 2009/04/11 23:05:26 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_tap.c,v 1.58 2009/07/23 17:53:17 plunky Exp $");
 #if defined(_KERNEL_OPT)
 #include "bpfilter.h"
 #include "opt_modular.h"
 #include "opt_compat_netbsd.h"
 #endif
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/kernel.h>
 #include <sys/malloc.h>
 #include <sys/conf.h>
 #include <sys/device.h>
 #include <sys/file.h>
 #include <sys/filedesc.h>
 #include <sys/ksyms.h>
 #include <sys/poll.h>
 #include <sys/proc.h>
 #include <sys/select.h>
 #include <sys/sockio.h>
 #if defined(COMPAT_40) || defined(MODULAR)
 #include <sys/sysctl.h>
 #endif
 #include <sys/kauth.h>
 #include <sys/mutex.h>
 #include <sys/simplelock.h>
 #include <sys/intr.h>
 #include <sys/stat.h>
 #include <net/if.h>
 #include <net/if_dl.h>
 #include <net/if_ether.h>
 #include <net/if_media.h>
 #include <net/if_tap.h>
 #if NBPFILTER > 0
 #include <net/bpf.h>
 #endif
 #include <compat/sys/sockio.h>
 #if defined(COMPAT_40) || defined(MODULAR)
 /*
  * sysctl node management
+ *
  * It's not really possible to use a SYSCTL_SETUP block with
  * current module implementation, so it is easier to just define
  * our own function.
+ *
  * The handler function is a "helper" in Andrew Brown's sysctl
  * framework terminology.  It is used as a gateway for sysctl
  * requests over the nodes.
+ *
  * tap_log allows the module to log creations of nodes and
  * destroy them all at once using sysctl_teardown.
  */
 static int tap_node;
 static int	tap_sysctl_handler(SYSCTLFN_PROTO);
 SYSCTL_SETUP_PROTO(sysctl_tap_setup);
 #endif
 /*
  * Since we're an Ethernet device, we need the 3 following
  * components: a leading struct device, a struct ethercom,
  * and also a struct ifmedia since we don't attach a PHY to
  * ourselves. We could emulate one, but there's no real
  * point.
  */
 struct tap_softc {
 	device_t	sc_dev;
 	struct ifmedia	sc_im;
 	struct ethercom	sc_ec;
 	int		sc_flags;
 #define	TAP_INUSE	0x00000001	/* tap device can only be opened once */
 #define TAP_ASYNCIO	0x00000002	/* user is using async I/O (SIGIO) on the device */
 #define TAP_NBIO	0x00000004	/* user wants calls to avoid blocking */
 #define TAP_GOING	0x00000008	/* interface is being destroyed */
 	struct selinfo	sc_rsel;
 	pid_t		sc_pgid; /* For async. IO */
 	kmutex_t	sc_rdlock;
 	struct simplelock	sc_kqlock;
 	void		*sc_sih;
 	struct timespec sc_atime;
 	struct timespec sc_mtime;
 	struct timespec sc_btime;
 };
 /* autoconf(9) glue */
 void	tapattach(int);
 static int	tap_match(device_t, cfdata_t, void *);
 static void	tap_attach(device_t, device_t, void *);
 static int	tap_detach(device_t, int);
 CFATTACH_DECL_NEW(tap, sizeof(struct tap_softc),
     tap_match, tap_attach, tap_detach, NULL);
 extern struct cfdriver tap_cd;
 /* Real device access routines */
 static int	tap_dev_close(struct tap_softc *);
 static int	tap_dev_read(int, struct uio *, int);
 static int	tap_dev_write(int, struct uio *, int);
 static int	tap_dev_ioctl(int, u_long, void *, struct lwp *);
 static int	tap_dev_poll(int, int, struct lwp *);
 static int	tap_dev_kqfilter(int, struct knote *);
 /* Fileops access routines */
 static int	tap_fops_close(file_t *);
 static int	tap_fops_read(file_t *, off_t *, struct uio *,
     kauth_cred_t, int);
 static int	tap_fops_write(file_t *, off_t *, struct uio *,
     kauth_cred_t, int);
 static int	tap_fops_ioctl(file_t *, u_long, void *);
 static int	tap_fops_poll(file_t *, int);
 static int	tap_fops_stat(file_t *, struct stat *);
 static int	tap_fops_kqfilter(file_t *, struct knote *);
 static const struct fileops tap_fileops = {
 	.fo_read = tap_fops_read,
 	.fo_write = tap_fops_write,
 	.fo_ioctl = tap_fops_ioctl,
 	.fo_fcntl = fnullop_fcntl,
 	.fo_poll = tap_fops_poll,
 	.fo_stat = tap_fops_stat,
 	.fo_close = tap_fops_close,
 	.fo_kqfilter = tap_fops_kqfilter,
 	.fo_drain = fnullop_drain,
 };
 /* Helper for cloning open() */
 static int	tap_dev_cloner(struct lwp *);
 /* Character device routines */
 static int	tap_cdev_open(dev_t, int, int, struct lwp *);
 static int	tap_cdev_close(dev_t, int, int, struct lwp *);
 static int	tap_cdev_read(dev_t, struct uio *, int);
 static int	tap_cdev_write(dev_t, struct uio *, int);
 static int	tap_cdev_ioctl(dev_t, u_long, void *, int, struct lwp *);
 static int	tap_cdev_poll(dev_t, int, struct lwp *);
 static int	tap_cdev_kqfilter(dev_t, struct knote *);
 const struct cdevsw tap_cdevsw = {
 	tap_cdev_open, tap_cdev_close,
 	tap_cdev_read, tap_cdev_write,
 	tap_cdev_ioctl, nostop, notty,
 	tap_cdev_poll, nommap,
 	tap_cdev_kqfilter,
 	D_OTHER,
 };
 #define TAP_CLONER	0xfffff		/* Maximal minor value */
 /* kqueue-related routines */
 static void	tap_kqdetach(struct knote *);
 static int	tap_kqread(struct knote *, long);
 /*
  * Those are needed by the if_media interface.
  */
 static int	tap_mediachange(struct ifnet *);
 static void	tap_mediastatus(struct ifnet *, struct ifmediareq *);
 /*
  * Those are needed by the ifnet interface, and would typically be
  * there for any network interface driver.
  * Some other routines are optional: watchdog and drain.
  */
 static void	tap_start(struct ifnet *);
 static void	tap_stop(struct ifnet *, int);
 static int	tap_init(struct ifnet *);
 static int	tap_ioctl(struct ifnet *, u_long, void *);
 /* Internal functions */
 #if defined(COMPAT_40) || defined(MODULAR)
 static int	tap_lifaddr(struct ifnet *, u_long, struct ifaliasreq *);
 #endif
 static void	tap_softintr(void *);
 /*
  * tap is a clonable interface, although it is highly unrealistic for
  * an Ethernet device.
+ *
  * Here are the bits needed for a clonable interface.
  */
 static int	tap_clone_create(struct if_clone *, int);
 static int	tap_clone_destroy(struct ifnet *);
 struct if_clone tap_cloners = IF_CLONE_INITIALIZER("tap",
 					tap_clone_create,
 					tap_clone_destroy);
 /* Helper functionis shared by the two cloning code paths */
 static struct tap_softc *	tap_clone_creator(int);
 int	tap_clone_destroyer(device_t);
 void
 tapattach(int n)
+{
 	int error;
 	error = config_cfattach_attach(tap_cd.cd_name, &tap_ca);
 	if (error) {
 		aprint_error("%s: unable to register cfattach\n",
 		    tap_cd.cd_name);
 		(void)config_cfdriver_detach(&tap_cd);
 		return;
+	}
 	if_clone_attach(&tap_cloners);
+}
 /* Pretty much useless for a pseudo-device */
 static int
 tap_match(device_t parent, cfdata_t cfdata, void *arg)
+{
 	return (1);
+}
 void
 tap_attach(device_t parent, device_t self, void *aux)
+{
 	struct tap_softc *sc = device_private(self);
 	struct ifnet *ifp;
 #if defined(COMPAT_40) || defined(MODULAR)
 	const struct sysctlnode *node;
 	int error;
 #endif
 	uint8_t enaddr[ETHER_ADDR_LEN] =
 	    { 0xf2, 0x0b, 0xa4, 0xff, 0xff, 0xff };
 	char enaddrstr[3 * ETHER_ADDR_LEN];
 	struct timeval tv;
 	uint32_t ui;
 	sc->sc_dev = self;
 	sc->sc_sih = softint_establish(SOFTINT_CLOCK, tap_softintr, sc);
 	getnanotime(&sc->sc_btime);
 	sc->sc_atime = sc->sc_mtime = sc->sc_btime;
 	if (!pmf_device_register(self, NULL, NULL))
 		aprint_error_dev(self, "couldn't establish power handler\n");
 	/*
 	 * In order to obtain unique initial Ethernet address on a host,
 	 * do some randomisation using the current uptime.  It's not meant
 	 * for anything but avoiding hard-coding an address.
 	 */
 	getmicrouptime(&tv);
 	ui = (tv.tv_sec ^ tv.tv_usec) & 0xffffff;
 	memcpy(enaddr+3, (uint8_t *)&ui, 3);
 	aprint_verbose_dev(self, "Ethernet address %s\n",
 	    ether_snprintf(enaddrstr, sizeof(enaddrstr), enaddr));
 	/*
 	 * Why 1000baseT? Why not? You can add more.
+	 *
 	 * Note that there are 3 steps: init, one or several additions to
 	 * list of supported media, and in the end, the selection of one
 	 * of them.
 	 */
 	ifmedia_init(&sc->sc_im, 0, tap_mediachange, tap_mediastatus);
 	ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_1000_T, 0, NULL);
 	ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_1000_T|IFM_FDX, 0, NULL);
 	ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_100_TX, 0, NULL);
 	ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_100_TX|IFM_FDX, 0, NULL);
 	ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_10_T, 0, NULL);
 	ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_10_T|IFM_FDX, 0, NULL);
 	ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_AUTO, 0, NULL);
 	ifmedia_set(&sc->sc_im, IFM_ETHER|IFM_AUTO);
 	/*
 	 * One should note that an interface must do multicast in order
 	 * to support IPv6.
 	 */
 	ifp = &sc->sc_ec.ec_if;
 	strcpy(ifp->if_xname, device_xname(self));
 	ifp->if_softc	= sc;
 	ifp->if_flags	= IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
 	ifp->if_ioctl	= tap_ioctl;
 	ifp->if_start	= tap_start;
 	ifp->if_stop	= tap_stop;
 	ifp->if_init	= tap_init;
 	IFQ_SET_READY(&ifp->if_snd);
 	sc->sc_ec.ec_capabilities = ETHERCAP_VLAN_MTU | ETHERCAP_JUMBO_MTU;
 	/* Those steps are mandatory for an Ethernet driver, the fisrt call
 	 * being common to all network interface drivers. */
 	if_attach(ifp);
 	ether_ifattach(ifp, enaddr);
 	sc->sc_flags = 0;
 #if defined(COMPAT_40) || defined(MODULAR)
 	/*
 	 * Add a sysctl node for that interface.
+	 *
 	 * The pointer transmitted is not a string, but instead a pointer to
 	 * the softc structure, which we can use to build the string value on
 	 * the fly in the helper function of the node.  See the comments for
 	 * tap_sysctl_handler for details.
+	 *
 	 * Usually sysctl_createv is called with CTL_CREATE as the before-last
 	 * component.  However, we can allocate a number ourselves, as we are
 	 * the only consumer of the net.link.<iface> node.  In this case, the
 	 * unit number is conveniently used to number the node.  CTL_CREATE
 	 * would just work, too.
 	 */
 	if ((error = sysctl_createv(NULL, 0, NULL,
 	    &node, CTLFLAG_READWRITE,
 	    CTLTYPE_STRING, device_xname(self), NULL,
 	    tap_sysctl_handler, 0, sc, 18,
 	    CTL_NET, AF_LINK, tap_node, device_unit(sc->sc_dev),
 	    CTL_EOL)) != 0)
 		aprint_error_dev(self, "sysctl_createv returned %d, ignoring\n",
 		    error);
 #endif
 	/*
 	 * Initialize the two locks for the device.
+	 *
 	 * We need a lock here because even though the tap device can be
 	 * opened only once, the file descriptor might be passed to another
 	 * process, say a fork(2)ed child.
+	 *
 	 * The Giant saves us from most of the hassle, but since the read
 	 * operation can sleep, we don't want two processes to wake up at
 	 * the same moment and both try and dequeue a single packet.
+	 *
 	 * The queue for event listeners (used by kqueue(9), see below) has
 	 * to be protected, too, but we don't need the same level of
 	 * complexity for that lock, so a simple spinning lock is fine.
 	 */
 	mutex_init(&sc->sc_rdlock, MUTEX_DEFAULT, IPL_NONE);
 	simple_lock_init(&sc->sc_kqlock);
 	selinit(&sc->sc_rsel);
+}
 /*
  * When detaching, we do the inverse of what is done in the attach
  * routine, in reversed order.
  */
 static int
 tap_detach(device_t self, int flags)
+{
 	struct tap_softc *sc = device_private(self);
 	struct ifnet *ifp = &sc->sc_ec.ec_if;
 #if defined(COMPAT_40) || defined(MODULAR)
 	int error;
 #endif
 	int s;
 	sc->sc_flags |= TAP_GOING;
 	s = splnet();
 	tap_stop(ifp, 1);
 	if_down(ifp);
 	splx(s);
 	softint_disestablish(sc->sc_sih);
 #if defined(COMPAT_40) || defined(MODULAR)
 	/*
 	 * Destroying a single leaf is a very straightforward operation using
 	 * sysctl_destroyv.  One should be sure to always end the path with
 	 * CTL_EOL.
 	 */
 	if ((error = sysctl_destroyv(NULL, CTL_NET, AF_LINK, tap_node,
 	    device_unit(sc->sc_dev), CTL_EOL)) != 0)
 		aprint_error_dev(self,
 		    "sysctl_destroyv returned %d, ignoring\n", error);
 #endif
 	ether_ifdetach(ifp);
 	if_detach(ifp);
 	ifmedia_delete_instance(&sc->sc_im, IFM_INST_ANY);
 	seldestroy(&sc->sc_rsel);
 	mutex_destroy(&sc->sc_rdlock);
 	pmf_device_deregister(self);
 	return (0);
+}
 /*
  * This function is called by the ifmedia layer to notify the driver
  * that the user requested a media change.  A real driver would
  * reconfigure the hardware.
  */
 static int
 tap_mediachange(struct ifnet *ifp)
+{
 	return (0);
+}
 /*
  * Here the user asks for the currently used media.
  */
 static void
 tap_mediastatus(struct ifnet *ifp, struct ifmediareq *imr)
+{
 	struct tap_softc *sc = (struct tap_softc *)ifp->if_softc;
 	imr->ifm_active = sc->sc_im.ifm_cur->ifm_media;
+}
 /*
  * This is the function where we SEND packets.
+ *
  * There is no 'receive' equivalent.  A typical driver will get
  * interrupts from the hardware, and from there will inject new packets
  * into the network stack.
+ *
  * Once handled, a packet must be freed.  A real driver might not be able
  * to fit all the pending packets into the hardware, and is allowed to
  * return before having sent all the packets.  It should then use the
  * if_flags flag IFF_OACTIVE to notify the upper layer.
+ *
  * There are also other flags one should check, such as IFF_PAUSE.
+ *
  * It is our duty to make packets available to BPF listeners.
+ *
  * You should be aware that this function is called by the Ethernet layer
  * at splnet().
+ *
  * When the device is opened, we have to pass the packet(s) to the
  * userland.  For that we stay in OACTIVE mode while the userland gets
  * the packets, and we send a signal to the processes waiting to read.
+ *
  * wakeup(sc) is the counterpart to the tsleep call in
  * tap_dev_read, while selnotify() is used for kevent(2) and
  * poll(2) (which includes select(2)) listeners.
  */
 static void
 tap_start(struct ifnet *ifp)
+{
 	struct tap_softc *sc = (struct tap_softc *)ifp->if_softc;
 	struct mbuf *m0;
 	if ((sc->sc_flags & TAP_INUSE) == 0) {
 		/* Simply drop packets */
 		for(;;) {
 			IFQ_DEQUEUE(&ifp->if_snd, m0);
 			if (m0 == NULL)
 				return;
 			ifp->if_opackets++;
 #if NBPFILTER > 0
 			if (ifp->if_bpf)
 				bpf_mtap(ifp->if_bpf, m0);
 #endif
 			m_freem(m0);
+		}
 	} else if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
 		ifp->if_flags |= IFF_OACTIVE;
 		wakeup(sc);
 		selnotify(&sc->sc_rsel, 0, 1);
 		if (sc->sc_flags & TAP_ASYNCIO)
 			softint_schedule(sc->sc_sih);
+	}
+}
 static void
 tap_softintr(void *cookie)
+{
 	struct tap_softc *sc;
 	struct ifnet *ifp;
 	int a, b;
 	sc = cookie;
 	if (sc->sc_flags & TAP_ASYNCIO) {
 		ifp = &sc->sc_ec.ec_if;
 		if (ifp->if_flags & IFF_RUNNING) {
 			a = POLL_IN;
 			b = POLLIN|POLLRDNORM;
 		} else {
 			a = POLL_HUP;
 			b = 0;
+		}
 		fownsignal(sc->sc_pgid, SIGIO, a, b, NULL);
+	}
+}
 /*
  * A typical driver will only contain the following handlers for
  * ioctl calls, except SIOCSIFPHYADDR.
  * The latter is a hack I used to set the Ethernet address of the
  * faked device.
+ *
  * Note that both ifmedia_ioctl() and ether_ioctl() have to be
  * called under splnet().
  */
 static int
 tap_ioctl(struct ifnet *ifp, u_long cmd, void *data)
+{
 	struct tap_softc *sc = (struct tap_softc *)ifp->if_softc;
 	struct ifreq *ifr = (struct ifreq *)data;
 	int s, error;
 	s = splnet();
 	switch (cmd) {
 #ifdef OSIOCSIFMEDIA
 	case OSIOCSIFMEDIA:
 #endif
 	case SIOCSIFMEDIA:
 	case SIOCGIFMEDIA:
 		error = ifmedia_ioctl(ifp, ifr, &sc->sc_im, cmd);
 		break;
 #if defined(COMPAT_40) || defined(MODULAR)
 	case SIOCSIFPHYADDR:
 		error = tap_lifaddr(ifp, cmd, (struct ifaliasreq *)data);
 		break;
 #endif
 	default:
 		error = ether_ioctl(ifp, cmd, data);
 		if (error == ENETRESET)
 			error = 0;
 		break;
+	}
 	splx(s);
 	return (error);
+}
 #if defined(COMPAT_40) || defined(MODULAR)
 /*
  * Helper function to set Ethernet address.  This has been replaced by
  * the generic SIOCALIFADDR ioctl on a PF_LINK socket.
  */
 static int
 tap_lifaddr(struct ifnet *ifp, u_long cmd, struct ifaliasreq *ifra)
+{
 	const struct sockaddr *sa = &ifra->ifra_addr;
 	if (sa->sa_family != AF_LINK)
 		return (EINVAL);
 	if_set_sadl(ifp, sa->sa_data, ETHER_ADDR_LEN, false);
 	return (0);
+}
 #endif
 /*
  * _init() would typically be called when an interface goes up,
  * meaning it should configure itself into the state in which it
  * can send packets.
  */
 static int
 tap_init(struct ifnet *ifp)
+{
 	ifp->if_flags |= IFF_RUNNING;
 	tap_start(ifp);
 	return (0);
+}
 /*
  * _stop() is called when an interface goes down.  It is our
  * responsability to validate that state by clearing the
  * IFF_RUNNING flag.
+ *
  * We have to wake up all the sleeping processes to have the pending
  * read requests cancelled.
  */
 static void
 tap_stop(struct ifnet *ifp, int disable)
+{
 	struct tap_softc *sc = (struct tap_softc *)ifp->if_softc;
 	ifp->if_flags &= ~IFF_RUNNING;
 	wakeup(sc);
 	selnotify(&sc->sc_rsel, 0, 1);
 	if (sc->sc_flags & TAP_ASYNCIO)
 		softint_schedule(sc->sc_sih);
+}
 /*
  * The 'create' command of ifconfig can be used to create
  * any numbered instance of a given device.  Thus we have to
  * make sure we have enough room in cd_devs to create the
  * user-specified instance.  config_attach_pseudo will do this
  * for us.
  */
 static int
 tap_clone_create(struct if_clone *ifc, int unit)
+{
 	if (tap_clone_creator(unit) == NULL) {
 		aprint_error("%s%d: unable to attach an instance\n",
                     tap_cd.cd_name, unit);
 		return (ENXIO);
+	}
 	return (0);
+}
 /*
  * tap(4) can be cloned by two ways:
  *   using 'ifconfig tap0 create', which will use the network
  *     interface cloning API, and call tap_clone_create above.
  *   opening the cloning device node, whose minor number is TAP_CLONER.
  *     See below for an explanation on how this part work.
  */
 static struct tap_softc *
 tap_clone_creator(int unit)
+{
 	struct cfdata *cf;
 	cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK);
 	cf->cf_name = tap_cd.cd_name;
 	cf->cf_atname = tap_ca.ca_name;
 	if (unit == -1) {
 		/* let autoconf find the first free one */
 		cf->cf_unit = 0;
 		cf->cf_fstate = FSTATE_STAR;
 	} else {
 		cf->cf_unit = unit;
-		cf->cf_fstate = FSTATE_FOUND;
+		cf->cf_fstate = FSTATE_NOTFOUND;
+	}
 	return device_private(config_attach_pseudo(cf));
+}
 /*
  * The clean design of if_clone and autoconf(9) makes that part
  * really straightforward.  The second argument of config_detach
  * means neither QUIET nor FORCED.
  */
 static int
 tap_clone_destroy(struct ifnet *ifp)
+{
 	struct tap_softc *sc = ifp->if_softc;
 	return tap_clone_destroyer(sc->sc_dev);
+}
 int
 tap_clone_destroyer(device_t dev)
+{
 	cfdata_t cf = device_cfdata(dev);
 	int error;
 	if ((error = config_detach(dev, 0)) != 0)
 		aprint_error_dev(dev, "unable to detach instance\n");
 	free(cf, M_DEVBUF);
 	return (error);
+}
 /*
  * tap(4) is a bit of an hybrid device.  It can be used in two different
  * ways:
  *  1. ifconfig tapN create, then use /dev/tapN to read/write off it.
  *  2. open /dev/tap, get a new interface created and read/write off it.
  *     That interface is destroyed when the process that had it created exits.
+ *
  * The first way is managed by the cdevsw structure, and you access interfaces
  * through a (major, minor) mapping:  tap4 is obtained by the minor number
  * 4.  The entry points for the cdevsw interface are prefixed by tap_cdev_.
+ *
  * The second way is the so-called "cloning" device.  It's a special minor
  * number (chosen as the maximal number, to allow as much tap devices as
  * possible).  The user first opens the cloner (e.g., /dev/tap), and that
  * call ends in tap_cdev_open.  The actual place where it is handled is
  * tap_dev_cloner.
+ *
  * An tap device cannot be opened more than once at a time, so the cdevsw
  * part of open() does nothing but noting that the interface is being used and
  * hence ready to actually handle packets.
  */
 static int
 tap_cdev_open(dev_t dev, int flags, int fmt, struct lwp *l)
+{
 	struct tap_softc *sc;
 	if (minor(dev) == TAP_CLONER)
 		return tap_dev_cloner(l);
 	sc = device_lookup_private(&tap_cd, minor(dev));
 	if (sc == NULL)
 		return (ENXIO);
 	/* The device can only be opened once */
 	if (sc->sc_flags & TAP_INUSE)
 		return (EBUSY);
 	sc->sc_flags |= TAP_INUSE;
 	return (0);
+}
 /*
  * There are several kinds of cloning devices, and the most simple is the one
  * tap(4) uses.  What it does is change the file descriptor with a new one,
  * with its own fileops structure (which maps to the various read, write,
  * ioctl functions).  It starts allocating a new file descriptor with falloc,
  * then actually creates the new tap devices.
+ *
  * Once those two steps are successful, we can re-wire the existing file
  * descriptor to its new self.  This is done with fdclone():  it fills the fp
  * structure as needed (notably f_data gets filled with the fifth parameter
  * passed, the unit of the tap device which will allows us identifying the
  * device later), and returns EMOVEFD.
+ *
  * That magic value is interpreted by sys_open() which then replaces the
  * current file descriptor by the new one (through a magic member of struct
  * lwp, l_dupfd).
+ *
  * The tap device is flagged as being busy since it otherwise could be
  * externally accessed through the corresponding device node with the cdevsw
  * interface.
  */
 static int
 tap_dev_cloner(struct lwp *l)
+{
 	struct tap_softc *sc;
 	file_t *fp;
 	int error, fd;
 	if ((error = fd_allocfile(&fp, &fd)) != 0)
 		return (error);
 	if ((sc = tap_clone_creator(-1)) == NULL) {
 		fd_abort(curproc, fp, fd);
 		return (ENXIO);
+	}
 	sc->sc_flags |= TAP_INUSE;
 	return fd_clone(fp, fd, FREAD|FWRITE, &tap_fileops,
 	    (void *)(intptr_t)device_unit(sc->sc_dev));
+}
 /*
  * While all other operations (read, write, ioctl, poll and kqfilter) are
  * really the same whether we are in cdevsw or fileops mode, the close()
  * function is slightly different in the two cases.
+ *
  * As for the other, the core of it is shared in tap_dev_close.  What
  * it does is sufficient for the cdevsw interface, but the cloning interface
  * needs another thing:  the interface is destroyed when the processes that
  * created it closes it.
  */
 static int
 tap_cdev_close(dev_t dev, int flags, int fmt,
     struct lwp *l)
+{
 	struct tap_softc *sc =
 	    device_lookup_private(&tap_cd, minor(dev));
 	if (sc == NULL)
 		return (ENXIO);
 	return tap_dev_close(sc);
+}
 /*
  * It might happen that the administrator used ifconfig to externally destroy
  * the interface.  In that case, tap_fops_close will be called while
  * tap_detach is already happening.  If we called it again from here, we
  * would dead lock.  TAP_GOING ensures that this situation doesn't happen.
  */
 static int
 tap_fops_close(file_t *fp)
+{
 	int unit = (intptr_t)fp->f_data;
 	struct tap_softc *sc;
 	int error;
 	sc = device_lookup_private(&tap_cd, unit);
 	if (sc == NULL)
 		return (ENXIO);
 	/* tap_dev_close currently always succeeds, but it might not
 	 * always be the case. */
 	KERNEL_LOCK(1, NULL);
 	if ((error = tap_dev_close(sc)) != 0) {
 		KERNEL_UNLOCK_ONE(NULL);
 		return (error);
+	}
 	/* Destroy the device now that it is no longer useful,
 	 * unless it's already being destroyed. */
 	if ((sc->sc_flags & TAP_GOING) != 0) {
 		KERNEL_UNLOCK_ONE(NULL);
 		return (0);
+	}
 	error = tap_clone_destroyer(sc->sc_dev);
 	KERNEL_UNLOCK_ONE(NULL);
 	return error;
+}
 static int
 tap_dev_close(struct tap_softc *sc)
+{
 	struct ifnet *ifp;
 	int s;
 	s = splnet();
 	/* Let tap_start handle packets again */
 	ifp = &sc->sc_ec.ec_if;
 	ifp->if_flags &= ~IFF_OACTIVE;
 	/* Purge output queue */
 	if (!(IFQ_IS_EMPTY(&ifp->if_snd))) {
 		struct mbuf *m;
 		for (;;) {
 			IFQ_DEQUEUE(&ifp->if_snd, m);
 			if (m == NULL)
 				break;
 			ifp->if_opackets++;
 #if NBPFILTER > 0
 			if (ifp->if_bpf)
 				bpf_mtap(ifp->if_bpf, m);
 #endif
+		}
+	}
 	splx(s);
 	sc->sc_flags &= ~(TAP_INUSE | TAP_ASYNCIO);
 	return (0);
+}
 static int
 tap_cdev_read(dev_t dev, struct uio *uio, int flags)
+{
 	return tap_dev_read(minor(dev), uio, flags);
+}
 static int
 tap_fops_read(file_t *fp, off_t *offp, struct uio *uio,
     kauth_cred_t cred, int flags)
+{
 	int error;
 	KERNEL_LOCK(1, NULL);
 	error = tap_dev_read((intptr_t)fp->f_data, uio, flags);
 	KERNEL_UNLOCK_ONE(NULL);
 	return error;
+}
 static int
 tap_dev_read(int unit, struct uio *uio, int flags)
+{
 	struct tap_softc *sc =
 	    device_lookup_private(&tap_cd, unit);
 	struct ifnet *ifp;
 	struct mbuf *m, *n;
 	int error = 0, s;
 	if (sc == NULL)
 		return (ENXIO);
 	getnanotime(&sc->sc_atime);
 	ifp = &sc->sc_ec.ec_if;
 	if ((ifp->if_flags & IFF_UP) == 0)
 		return (EHOSTDOWN);
 	/*
 	 * In the TAP_NBIO case, we have to make sure we won't be sleeping
 	 */
 	if ((sc->sc_flags & TAP_NBIO) != 0) {
 		if (!mutex_tryenter(&sc->sc_rdlock))
 			return (EWOULDBLOCK);
 	} else {
 		mutex_enter(&sc->sc_rdlock);
+	}
 	s = splnet();
 	if (IFQ_IS_EMPTY(&ifp->if_snd)) {
 		ifp->if_flags &= ~IFF_OACTIVE;
 		/*
 		 * We must release the lock before sleeping, and re-acquire it
 		 * after.
 		 */
 		mutex_exit(&sc->sc_rdlock);
 		if (sc->sc_flags & TAP_NBIO)
 			error = EWOULDBLOCK;
 		else
 			error = tsleep(sc, PSOCK|PCATCH, "tap", 0);
 		splx(s);
 		if (error != 0)
 			return (error);
 		/* The device might have been downed */
 		if ((ifp->if_flags & IFF_UP) == 0)
 			return (EHOSTDOWN);
 		if ((sc->sc_flags & TAP_NBIO)) {
 			if (!mutex_tryenter(&sc->sc_rdlock))
 				return (EWOULDBLOCK);
 		} else {
 			mutex_enter(&sc->sc_rdlock);
+		}
 		s = splnet();
+	}
 	IFQ_DEQUEUE(&ifp->if_snd, m);
 	ifp->if_flags &= ~IFF_OACTIVE;
 	splx(s);
 	if (m == NULL) {
 		error = 0;
 		goto out;
+	}
 	ifp->if_opackets++;
 #if NBPFILTER > 0
 	if (ifp->if_bpf)
 		bpf_mtap(ifp->if_bpf, m);
 #endif
 	/*
 	 * One read is one packet.
 	 */
 	do {
 		error = uiomove(mtod(m, void *),
 		    min(m->m_len, uio->uio_resid), uio);
 		MFREE(m, n);
 		m = n;
 	} while (m != NULL && uio->uio_resid > 0 && error == 0);
 	if (m != NULL)
 		m_freem(m);
 out:
 	mutex_exit(&sc->sc_rdlock);
 	return (error);
+}
 static int
 tap_fops_stat(file_t *fp, struct stat *st)
+{
 	int error;
 	struct tap_softc *sc;
 	int unit = (uintptr_t)fp->f_data;
 	(void)memset(st, 0, sizeof(*st));
 	KERNEL_LOCK(1, NULL);
 	sc = device_lookup_private(&tap_cd, unit);
 	if (sc == NULL) {
 		error = ENXIO;
 		goto out;
+	}
 	st->st_dev = makedev(cdevsw_lookup_major(&tap_cdevsw), unit);
 	st->st_atimespec = sc->sc_atime;
 	st->st_mtimespec = sc->sc_mtime;
 	st->st_ctimespec = st->st_birthtimespec = sc->sc_btime;
 	st->st_uid = kauth_cred_geteuid(fp->f_cred);
 	st->st_gid = kauth_cred_getegid(fp->f_cred);
 out:
 	KERNEL_UNLOCK_ONE(NULL);
 	return error;
+}
 static int
 tap_cdev_write(dev_t dev, struct uio *uio, int flags)
+{
 	return tap_dev_write(minor(dev), uio, flags);
+}
 static int
 tap_fops_write(file_t *fp, off_t *offp, struct uio *uio,
     kauth_cred_t cred, int flags)
+{
 	int error;
 	KERNEL_LOCK(1, NULL);
 	error = tap_dev_write((intptr_t)fp->f_data, uio, flags);
 	KERNEL_UNLOCK_ONE(NULL);
 	return error;
+}
 static int
 tap_dev_write(int unit, struct uio *uio, int flags)
+{
 	struct tap_softc *sc =
 	    device_lookup_private(&tap_cd, unit);
 	struct ifnet *ifp;
 	struct mbuf *m, **mp;
 	int error = 0;
 	int s;
 	if (sc == NULL)
 		return (ENXIO);
 	getnanotime(&sc->sc_mtime);
 	ifp = &sc->sc_ec.ec_if;
 	/* One write, one packet, that's the rule */
 	MGETHDR(m, M_DONTWAIT, MT_DATA);
 	if (m == NULL) {
 		ifp->if_ierrors++;
 		return (ENOBUFS);
+	}
 	m->m_pkthdr.len = uio->uio_resid;
 	mp = &m;
 	while (error == 0 && uio->uio_resid > 0) {
 		if (*mp != m) {
 			MGET(*mp, M_DONTWAIT, MT_DATA);
 			if (*mp == NULL) {
 				error = ENOBUFS;
 				break;
+			}
+		}
 		(*mp)->m_len = min(MHLEN, uio->uio_resid);
 		error = uiomove(mtod(*mp, void *), (*mp)->m_len, uio);
 		mp = &(*mp)->m_next;
+	}
 	if (error) {
 		ifp->if_ierrors++;
 		m_freem(m);
 		return (error);
+	}
 	ifp->if_ipackets++;
 	m->m_pkthdr.rcvif = ifp;
 #if NBPFILTER > 0
 	if (ifp->if_bpf)
 		bpf_mtap(ifp->if_bpf, m);
 #endif
 	s =splnet();
 	(*ifp->if_input)(ifp, m);
 	splx(s);
 	return (0);
+}
 static int
 tap_cdev_ioctl(dev_t dev, u_long cmd, void *data, int flags,
     struct lwp *l)
+{
 	return tap_dev_ioctl(minor(dev), cmd, data, l);
+}
 static int
 tap_fops_ioctl(file_t *fp, u_long cmd, void *data)
+{
 	return tap_dev_ioctl((intptr_t)fp->f_data, cmd, data, curlwp);
+}
 static int
 tap_dev_ioctl(int unit, u_long cmd, void *data, struct lwp *l)
+{
 	struct tap_softc *sc =
 	    device_lookup_private(&tap_cd, unit);
 	int error = 0;
 	if (sc == NULL)
 		return (ENXIO);
 	switch (cmd) {
 	case FIONREAD:
+		{
 			struct ifnet *ifp = &sc->sc_ec.ec_if;
 			struct mbuf *m;
 			int s;
 			s = splnet();
 			IFQ_POLL(&ifp->if_snd, m);
 			if (m == NULL)
 				*(int *)data = 0;
 			else
 				*(int *)data = m->m_pkthdr.len;
 			splx(s);
 		} break;
 	case TIOCSPGRP:
 	case FIOSETOWN:
 		error = fsetown(&sc->sc_pgid, cmd, data);
 		break;
 	case TIOCGPGRP:
 	case FIOGETOWN:
 		error = fgetown(sc->sc_pgid, cmd, data);
 		break;
 	case FIOASYNC:
 		if (*(int *)data)
 			sc->sc_flags |= TAP_ASYNCIO;
 		else
 			sc->sc_flags &= ~TAP_ASYNCIO;
 		break;
 	case FIONBIO:
 		if (*(int *)data)
 			sc->sc_flags |= TAP_NBIO;
 		else
 			sc->sc_flags &= ~TAP_NBIO;
 		break;
 #ifdef OTAPGIFNAME
 	case OTAPGIFNAME:
 #endif
 	case TAPGIFNAME:
+		{
 			struct ifreq *ifr = (struct ifreq *)data;
 			struct ifnet *ifp = &sc->sc_ec.ec_if;
 			strlcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ);
 		} break;
 	default:
 		error = ENOTTY;
 		break;
+	}
 	return (0);
+}
 static int
 tap_cdev_poll(dev_t dev, int events, struct lwp *l)
+{
 	return tap_dev_poll(minor(dev), events, l);
+}
 static int
 tap_fops_poll(file_t *fp, int events)
+{
 	return tap_dev_poll((intptr_t)fp->f_data, events, curlwp);
+}
 static int
 tap_dev_poll(int unit, int events, struct lwp *l)
+{
 	struct tap_softc *sc =
 	    device_lookup_private(&tap_cd, unit);
 	int revents = 0;
 	if (sc == NULL)
 		return POLLERR;
 	if (events & (POLLIN|POLLRDNORM)) {
 		struct ifnet *ifp = &sc->sc_ec.ec_if;
 		struct mbuf *m;
 		int s;
 		s = splnet();
 		IFQ_POLL(&ifp->if_snd, m);
 		splx(s);
 		if (m != NULL)
 			revents |= events & (POLLIN|POLLRDNORM);
 		else {
 			simple_lock(&sc->sc_kqlock);
 			selrecord(l, &sc->sc_rsel);
 			simple_unlock(&sc->sc_kqlock);
+		}
+	}
 	revents |= events & (POLLOUT|POLLWRNORM);
 	return (revents);
+}
 static struct filterops tap_read_filterops = { 1, NULL, tap_kqdetach,
 	tap_kqread };
 static struct filterops tap_seltrue_filterops = { 1, NULL, tap_kqdetach,
 	filt_seltrue };
 static int
 tap_cdev_kqfilter(dev_t dev, struct knote *kn)
+{
 	return tap_dev_kqfilter(minor(dev), kn);
+}
 static int
 tap_fops_kqfilter(file_t *fp, struct knote *kn)
+{
 	return tap_dev_kqfilter((intptr_t)fp->f_data, kn);
+}
 static int
 tap_dev_kqfilter(int unit, struct knote *kn)
+{
 	struct tap_softc *sc =
 	    device_lookup_private(&tap_cd, unit);
 	if (sc == NULL)
 		return (ENXIO);
 	KERNEL_LOCK(1, NULL);
 	switch(kn->kn_filter) {
 	case EVFILT_READ:
 		kn->kn_fop = &tap_read_filterops;
 		break;
 	case EVFILT_WRITE:
 		kn->kn_fop = &tap_seltrue_filterops;
 		break;
 	default:
 		KERNEL_UNLOCK_ONE(NULL);
 		return (EINVAL);
+	}
 	kn->kn_hook = sc;
 	simple_lock(&sc->sc_kqlock);
 	SLIST_INSERT_HEAD(&sc->sc_rsel.sel_klist, kn, kn_selnext);
 	simple_unlock(&sc->sc_kqlock);
 	KERNEL_UNLOCK_ONE(NULL);
 	return (0);
+}
 static void
 tap_kqdetach(struct knote *kn)
+{
 	struct tap_softc *sc = (struct tap_softc *)kn->kn_hook;
 	KERNEL_LOCK(1, NULL);
 	simple_lock(&sc->sc_kqlock);
 	SLIST_REMOVE(&sc->sc_rsel.sel_klist, kn, knote, kn_selnext);
 	simple_unlock(&sc->sc_kqlock);
 	KERNEL_UNLOCK_ONE(NULL);
+}
 static int
 tap_kqread(struct knote *kn, long hint)
+{
 	struct tap_softc *sc = (struct tap_softc *)kn->kn_hook;
 	struct ifnet *ifp = &sc->sc_ec.ec_if;
 	struct mbuf *m;
 	int s, rv;
 	KERNEL_LOCK(1, NULL);
 	s = splnet();
 	IFQ_POLL(&ifp->if_snd, m);
 	if (m == NULL)
 		kn->kn_data = 0;
 	else
 		kn->kn_data = m->m_pkthdr.len;
 	splx(s);
 	rv = (kn->kn_data != 0 ? 1 : 0);
 	KERNEL_UNLOCK_ONE(NULL);
 	return rv;
+}
 #if defined(COMPAT_40) || defined(MODULAR)
 /*
  * sysctl management routines
  * You can set the address of an interface through:
  * net.link.tap.tap<number>
+ *
  * Note the consistent use of tap_log in order to use
  * sysctl_teardown at unload time.
+ *
  * In the kernel you will find a lot of SYSCTL_SETUP blocks.  Those
  * blocks register a function in a special section of the kernel
  * (called a link set) which is used at init_sysctl() time to cycle
  * through all those functions to create the kernel's sysctl tree.
+ *
  * It is not possible to use link sets in a module, so the
  * easiest is to simply call our own setup routine at load time.
+ *
  * In the SYSCTL_SETUP blocks you find in the kernel, nodes have the
  * CTLFLAG_PERMANENT flag, meaning they cannot be removed.  Once the
  * whole kernel sysctl tree is built, it is not possible to add any
  * permanent node.
+ *
  * It should be noted that we're not saving the sysctlnode pointer
  * we are returned when creating the "tap" node.  That structure
  * cannot be trusted once out of the calling function, as it might
  * get reused.  So we just save the MIB number, and always give the
  * full path starting from the root for later calls to sysctl_createv
  * and sysctl_destroyv.
  */
 SYSCTL_SETUP(sysctl_tap_setup, "sysctl net.link.tap subtree setup")
+{
 	const struct sysctlnode *node;
 	int error = 0;
 	if ((error = sysctl_createv(clog, 0, NULL, NULL,
 	    CTLFLAG_PERMANENT,
 	    CTLTYPE_NODE, "net", NULL,
 	    NULL, 0, NULL, 0,
 	    CTL_NET, CTL_EOL)) != 0)
 		return;
 	if ((error = sysctl_createv(clog, 0, NULL, NULL,
 	    CTLFLAG_PERMANENT,
 	    CTLTYPE_NODE, "link", NULL,
 	    NULL, 0, NULL, 0,
 	    CTL_NET, AF_LINK, CTL_EOL)) != 0)
 		return;
 	/*
 	 * The first four parameters of sysctl_createv are for management.
+	 *
 	 * The four that follows, here starting with a '0' for the flags,
 	 * describe the node.
+	 *
 	 * The next series of four set its value, through various possible
 	 * means.
+	 *
 	 * Last but not least, the path to the node is described.  That path
 	 * is relative to the given root (third argument).  Here we're
 	 * starting from the root.
 	 */
 	if ((error = sysctl_createv(clog, 0, NULL, &node,
 	    CTLFLAG_PERMANENT,
 	    CTLTYPE_NODE, "tap", NULL,
 	    NULL, 0, NULL, 0,
 	    CTL_NET, AF_LINK, CTL_CREATE, CTL_EOL)) != 0)
 		return;
 	tap_node = node->sysctl_num;
+}
 /*
  * The helper functions make Andrew Brown's interface really
  * shine.  It makes possible to create value on the fly whether
  * the sysctl value is read or written.
+ *
  * As shown as an example in the man page, the first step is to
  * create a copy of the node to have sysctl_lookup work on it.
+ *
  * Here, we have more work to do than just a copy, since we have
  * to create the string.  The first step is to collect the actual
  * value of the node, which is a convenient pointer to the softc
  * of the interface.  From there we create the string and use it
  * as the value, but only for the *copy* of the node.
+ *
  * Then we let sysctl_lookup do the magic, which consists in
  * setting oldp and newp as required by the operation.  When the
  * value is read, that means that the string will be copied to
  * the user, and when it is written, the new value will be copied
  * over in the addr array.
+ *
  * If newp is NULL, the user was reading the value, so we don't
  * have anything else to do.  If a new value was written, we
  * have to check it.
+ *
  * If it is incorrect, we can return an error and leave 'node' as
  * it is:  since it is a copy of the actual node, the change will
  * be forgotten.
+ *
  * Upon a correct input, we commit the change to the ifnet
  * structure of our interface.
  */
 static int
 tap_sysctl_handler(SYSCTLFN_ARGS)
+{
 	struct sysctlnode node;
 	struct tap_softc *sc;
 	struct ifnet *ifp;
 	int error;
 	size_t len;
 	char addr[3 * ETHER_ADDR_LEN];
 	uint8_t enaddr[ETHER_ADDR_LEN];
 	node = *rnode;
 	sc = node.sysctl_data;
 	ifp = &sc->sc_ec.ec_if;
 	(void)ether_snprintf(addr, sizeof(addr), CLLADDR(ifp->if_sadl));
 	node.sysctl_data = addr;
 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
 	if (error || newp == NULL)
 		return (error);
 	len = strlen(addr);
 	if (len < 11 || len > 17)
 		return (EINVAL);
 	/* Commit change */
 	if (ether_nonstatic_aton(enaddr, addr) != 0)
 		return (EINVAL);
 	if_set_sadl(ifp, enaddr, ETHER_ADDR_LEN, false);
 	return (error);
+}
 #endif