if_tap.c revision 243615
1/*-
2 * Copyright (C) 1999-2000 by Maksim Yevmenkin <m_evmenkin@yahoo.com>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * BASED ON:
27 * -------------------------------------------------------------------------
28 *
29 * Copyright (c) 1988, Julian Onions <jpo@cs.nott.ac.uk>
30 * Nottingham University 1987.
31 */
32
33/*
34 * $FreeBSD: head/sys/net/if_tap.c 243615 2012-11-27 12:23:57Z davidxu $
35 * $Id: if_tap.c,v 0.21 2000/07/23 21:46:02 max Exp $
36 */
37
38#include "opt_compat.h"
39#include "opt_inet.h"
40
41#include <sys/param.h>
42#include <sys/conf.h>
43#include <sys/fcntl.h>
44#include <sys/filio.h>
45#include <sys/jail.h>
46#include <sys/kernel.h>
47#include <sys/malloc.h>
48#include <sys/mbuf.h>
49#include <sys/module.h>
50#include <sys/poll.h>
51#include <sys/priv.h>
52#include <sys/proc.h>
53#include <sys/selinfo.h>
54#include <sys/signalvar.h>
55#include <sys/socket.h>
56#include <sys/sockio.h>
57#include <sys/sysctl.h>
58#include <sys/systm.h>
59#include <sys/ttycom.h>
60#include <sys/uio.h>
61#include <sys/queue.h>
62
63#include <net/bpf.h>
64#include <net/ethernet.h>
65#include <net/if.h>
66#include <net/if_clone.h>
67#include <net/if_dl.h>
68#include <net/if_media.h>
69#include <net/if_types.h>
70#include <net/route.h>
71#include <net/vnet.h>
72
73#include <netinet/in.h>
74
75#include <net/if_tapvar.h>
76#include <net/if_tap.h>
77
78
79#define CDEV_NAME	"tap"
80#define TAPDEBUG	if (tapdebug) printf
81
82static const char tapname[] = "tap";
83static const char vmnetname[] = "vmnet";
84#define TAPMAXUNIT	0x7fff
85#define VMNET_DEV_MASK	CLONE_FLAG0
86
87/* module */
88static int		tapmodevent(module_t, int, void *);
89
90/* device */
91static void		tapclone(void *, struct ucred *, char *, int,
92			    struct cdev **);
93static void		tapcreate(struct cdev *);
94
95/* network interface */
96static void		tapifstart(struct ifnet *);
97static int		tapifioctl(struct ifnet *, u_long, caddr_t);
98static void		tapifinit(void *);
99
100static int		tap_clone_create(struct if_clone *, int, caddr_t);
101static void		tap_clone_destroy(struct ifnet *);
102static struct if_clone *tap_cloner;
103static int		vmnet_clone_create(struct if_clone *, int, caddr_t);
104static void		vmnet_clone_destroy(struct ifnet *);
105static struct if_clone *vmnet_cloner;
106
107/* character device */
108static d_open_t		tapopen;
109static d_close_t	tapclose;
110static d_read_t		tapread;
111static d_write_t	tapwrite;
112static d_ioctl_t	tapioctl;
113static d_poll_t		tappoll;
114static d_kqfilter_t	tapkqfilter;
115
116/* kqueue(2) */
117static int		tapkqread(struct knote *, long);
118static int		tapkqwrite(struct knote *, long);
119static void		tapkqdetach(struct knote *);
120
121static struct filterops	tap_read_filterops = {
122	.f_isfd =	1,
123	.f_attach =	NULL,
124	.f_detach =	tapkqdetach,
125	.f_event =	tapkqread,
126};
127
128static struct filterops	tap_write_filterops = {
129	.f_isfd =	1,
130	.f_attach =	NULL,
131	.f_detach =	tapkqdetach,
132	.f_event =	tapkqwrite,
133};
134
135static struct cdevsw	tap_cdevsw = {
136	.d_version =	D_VERSION,
137	.d_flags =	D_NEEDMINOR,
138	.d_open =	tapopen,
139	.d_close =	tapclose,
140	.d_read =	tapread,
141	.d_write =	tapwrite,
142	.d_ioctl =	tapioctl,
143	.d_poll =	tappoll,
144	.d_name =	CDEV_NAME,
145	.d_kqfilter =	tapkqfilter,
146};
147
148/*
149 * All global variables in if_tap.c are locked with tapmtx, with the
150 * exception of tapdebug, which is accessed unlocked; tapclones is
151 * static at runtime.
152 */
153static struct mtx		tapmtx;
154static int			tapdebug = 0;        /* debug flag   */
155static int			tapuopen = 0;        /* allow user open() */
156static int			tapuponopen = 0;    /* IFF_UP on open() */
157static int			tapdclone = 1;	/* enable devfs cloning */
158static SLIST_HEAD(, tap_softc)	taphead;             /* first device */
159static struct clonedevs 	*tapclones;
160
161MALLOC_DECLARE(M_TAP);
162MALLOC_DEFINE(M_TAP, CDEV_NAME, "Ethernet tunnel interface");
163SYSCTL_INT(_debug, OID_AUTO, if_tap_debug, CTLFLAG_RW, &tapdebug, 0, "");
164
165SYSCTL_DECL(_net_link);
166static SYSCTL_NODE(_net_link, OID_AUTO, tap, CTLFLAG_RW, 0,
167    "Ethernet tunnel software network interface");
168SYSCTL_INT(_net_link_tap, OID_AUTO, user_open, CTLFLAG_RW, &tapuopen, 0,
169	"Allow user to open /dev/tap (based on node permissions)");
170SYSCTL_INT(_net_link_tap, OID_AUTO, up_on_open, CTLFLAG_RW, &tapuponopen, 0,
171	"Bring interface up when /dev/tap is opened");
172SYSCTL_INT(_net_link_tap, OID_AUTO, devfs_cloning, CTLFLAG_RW, &tapdclone, 0,
173	"Enably legacy devfs interface creation");
174SYSCTL_INT(_net_link_tap, OID_AUTO, debug, CTLFLAG_RW, &tapdebug, 0, "");
175
176TUNABLE_INT("net.link.tap.devfs_cloning", &tapdclone);
177
178DEV_MODULE(if_tap, tapmodevent, NULL);
179
180static int
181tap_clone_create(struct if_clone *ifc, int unit, caddr_t params)
182{
183	struct cdev *dev;
184	int i;
185
186	/* Find any existing device, or allocate new unit number. */
187	i = clone_create(&tapclones, &tap_cdevsw, &unit, &dev, 0);
188	if (i) {
189		dev = make_dev(&tap_cdevsw, unit, UID_ROOT, GID_WHEEL, 0600,
190		    "%s%d", tapname, unit);
191	}
192
193	tapcreate(dev);
194	return (0);
195}
196
197/* vmnet devices are tap devices in disguise */
198static int
199vmnet_clone_create(struct if_clone *ifc, int unit, caddr_t params)
200{
201	struct cdev *dev;
202	int i;
203
204	/* Find any existing device, or allocate new unit number. */
205	i = clone_create(&tapclones, &tap_cdevsw, &unit, &dev, VMNET_DEV_MASK);
206	if (i) {
207		dev = make_dev(&tap_cdevsw, unit | VMNET_DEV_MASK, UID_ROOT,
208		    GID_WHEEL, 0600, "%s%d", tapname, unit);
209	}
210
211	tapcreate(dev);
212	return (0);
213}
214
215static void
216tap_destroy(struct tap_softc *tp)
217{
218	struct ifnet *ifp = tp->tap_ifp;
219
220	CURVNET_SET(ifp->if_vnet);
221	destroy_dev(tp->tap_dev);
222	seldrain(&tp->tap_rsel);
223	knlist_destroy(&tp->tap_rsel.si_note);
224	ether_ifdetach(ifp);
225	if_free(ifp);
226
227	mtx_destroy(&tp->tap_mtx);
228	free(tp, M_TAP);
229	CURVNET_RESTORE();
230}
231
232static void
233tap_clone_destroy(struct ifnet *ifp)
234{
235	struct tap_softc *tp = ifp->if_softc;
236
237	mtx_lock(&tapmtx);
238	SLIST_REMOVE(&taphead, tp, tap_softc, tap_next);
239	mtx_unlock(&tapmtx);
240	tap_destroy(tp);
241}
242
243/* vmnet devices are tap devices in disguise */
244static void
245vmnet_clone_destroy(struct ifnet *ifp)
246{
247	tap_clone_destroy(ifp);
248}
249
250/*
251 * tapmodevent
252 *
253 * module event handler
254 */
255static int
256tapmodevent(module_t mod, int type, void *data)
257{
258	static eventhandler_tag	 eh_tag = NULL;
259	struct tap_softc	*tp = NULL;
260	struct ifnet		*ifp = NULL;
261
262	switch (type) {
263	case MOD_LOAD:
264
265		/* intitialize device */
266
267		mtx_init(&tapmtx, "tapmtx", NULL, MTX_DEF);
268		SLIST_INIT(&taphead);
269
270		clone_setup(&tapclones);
271		eh_tag = EVENTHANDLER_REGISTER(dev_clone, tapclone, 0, 1000);
272		if (eh_tag == NULL) {
273			clone_cleanup(&tapclones);
274			mtx_destroy(&tapmtx);
275			return (ENOMEM);
276		}
277		tap_cloner = if_clone_simple(tapname, tap_clone_create,
278		    tap_clone_destroy, 0);
279		vmnet_cloner = if_clone_simple(vmnetname, vmnet_clone_create,
280		    vmnet_clone_destroy, 0);
281		return (0);
282
283	case MOD_UNLOAD:
284		/*
285		 * The EBUSY algorithm here can't quite atomically
286		 * guarantee that this is race-free since we have to
287		 * release the tap mtx to deregister the clone handler.
288		 */
289		mtx_lock(&tapmtx);
290		SLIST_FOREACH(tp, &taphead, tap_next) {
291			mtx_lock(&tp->tap_mtx);
292			if (tp->tap_flags & TAP_OPEN) {
293				mtx_unlock(&tp->tap_mtx);
294				mtx_unlock(&tapmtx);
295				return (EBUSY);
296			}
297			mtx_unlock(&tp->tap_mtx);
298		}
299		mtx_unlock(&tapmtx);
300
301		EVENTHANDLER_DEREGISTER(dev_clone, eh_tag);
302		if_clone_detach(tap_cloner);
303		if_clone_detach(vmnet_cloner);
304		drain_dev_clone_events();
305
306		mtx_lock(&tapmtx);
307		while ((tp = SLIST_FIRST(&taphead)) != NULL) {
308			SLIST_REMOVE_HEAD(&taphead, tap_next);
309			mtx_unlock(&tapmtx);
310
311			ifp = tp->tap_ifp;
312
313			TAPDEBUG("detaching %s\n", ifp->if_xname);
314
315			tap_destroy(tp);
316			mtx_lock(&tapmtx);
317		}
318		mtx_unlock(&tapmtx);
319		clone_cleanup(&tapclones);
320
321		mtx_destroy(&tapmtx);
322
323		break;
324
325	default:
326		return (EOPNOTSUPP);
327	}
328
329	return (0);
330} /* tapmodevent */
331
332
333/*
334 * DEVFS handler
335 *
336 * We need to support two kind of devices - tap and vmnet
337 */
338static void
339tapclone(void *arg, struct ucred *cred, char *name, int namelen, struct cdev **dev)
340{
341	char		devname[SPECNAMELEN + 1];
342	int		i, unit, append_unit;
343	int		extra;
344
345	if (*dev != NULL)
346		return;
347
348	if (!tapdclone ||
349	    (!tapuopen && priv_check_cred(cred, PRIV_NET_IFCREATE, 0) != 0))
350		return;
351
352	unit = 0;
353	append_unit = 0;
354	extra = 0;
355
356	/* We're interested in only tap/vmnet devices. */
357	if (strcmp(name, tapname) == 0) {
358		unit = -1;
359	} else if (strcmp(name, vmnetname) == 0) {
360		unit = -1;
361		extra = VMNET_DEV_MASK;
362	} else if (dev_stdclone(name, NULL, tapname, &unit) != 1) {
363		if (dev_stdclone(name, NULL, vmnetname, &unit) != 1) {
364			return;
365		} else {
366			extra = VMNET_DEV_MASK;
367		}
368	}
369
370	if (unit == -1)
371		append_unit = 1;
372
373	CURVNET_SET(CRED_TO_VNET(cred));
374	/* find any existing device, or allocate new unit number */
375	i = clone_create(&tapclones, &tap_cdevsw, &unit, dev, extra);
376	if (i) {
377		if (append_unit) {
378			/*
379			 * We were passed 'tun' or 'tap', with no unit specified
380			 * so we'll need to append it now.
381			 */
382			namelen = snprintf(devname, sizeof(devname), "%s%d", name,
383			    unit);
384			name = devname;
385		}
386
387		*dev = make_dev_credf(MAKEDEV_REF, &tap_cdevsw, unit | extra,
388		     cred, UID_ROOT, GID_WHEEL, 0600, "%s", name);
389	}
390
391	if_clone_create(name, namelen, NULL);
392	CURVNET_RESTORE();
393} /* tapclone */
394
395
396/*
397 * tapcreate
398 *
399 * to create interface
400 */
401static void
402tapcreate(struct cdev *dev)
403{
404	struct ifnet		*ifp = NULL;
405	struct tap_softc	*tp = NULL;
406	unsigned short		 macaddr_hi;
407	uint32_t		 macaddr_mid;
408	int			 unit;
409	const char		*name = NULL;
410	u_char			eaddr[6];
411
412	dev->si_flags &= ~SI_CHEAPCLONE;
413
414	/* allocate driver storage and create device */
415	tp = malloc(sizeof(*tp), M_TAP, M_WAITOK | M_ZERO);
416	mtx_init(&tp->tap_mtx, "tap_mtx", NULL, MTX_DEF);
417	mtx_lock(&tapmtx);
418	SLIST_INSERT_HEAD(&taphead, tp, tap_next);
419	mtx_unlock(&tapmtx);
420
421	unit = dev2unit(dev);
422
423	/* select device: tap or vmnet */
424	if (unit & VMNET_DEV_MASK) {
425		name = vmnetname;
426		tp->tap_flags |= TAP_VMNET;
427	} else
428		name = tapname;
429
430	unit &= TAPMAXUNIT;
431
432	TAPDEBUG("tapcreate(%s%d). minor = %#x\n", name, unit, dev2unit(dev));
433
434	/* generate fake MAC address: 00 bd xx xx xx unit_no */
435	macaddr_hi = htons(0x00bd);
436	macaddr_mid = (uint32_t) ticks;
437	bcopy(&macaddr_hi, eaddr, sizeof(short));
438	bcopy(&macaddr_mid, &eaddr[2], sizeof(uint32_t));
439	eaddr[5] = (u_char)unit;
440
441	/* fill the rest and attach interface */
442	ifp = tp->tap_ifp = if_alloc(IFT_ETHER);
443	if (ifp == NULL)
444		panic("%s%d: can not if_alloc()", name, unit);
445	ifp->if_softc = tp;
446	if_initname(ifp, name, unit);
447	ifp->if_init = tapifinit;
448	ifp->if_start = tapifstart;
449	ifp->if_ioctl = tapifioctl;
450	ifp->if_mtu = ETHERMTU;
451	ifp->if_flags = (IFF_BROADCAST|IFF_SIMPLEX|IFF_MULTICAST);
452	IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
453	ifp->if_capabilities |= IFCAP_LINKSTATE;
454	ifp->if_capenable |= IFCAP_LINKSTATE;
455
456	dev->si_drv1 = tp;
457	tp->tap_dev = dev;
458
459	ether_ifattach(ifp, eaddr);
460
461	mtx_lock(&tp->tap_mtx);
462	tp->tap_flags |= TAP_INITED;
463	mtx_unlock(&tp->tap_mtx);
464
465	knlist_init_mtx(&tp->tap_rsel.si_note, &tp->tap_mtx);
466
467	TAPDEBUG("interface %s is created. minor = %#x\n",
468		ifp->if_xname, dev2unit(dev));
469} /* tapcreate */
470
471
472/*
473 * tapopen
474 *
475 * to open tunnel. must be superuser
476 */
477static int
478tapopen(struct cdev *dev, int flag, int mode, struct thread *td)
479{
480	struct tap_softc	*tp = NULL;
481	struct ifnet		*ifp = NULL;
482	int			 error;
483
484	if (tapuopen == 0) {
485		error = priv_check(td, PRIV_NET_TAP);
486		if (error)
487			return (error);
488	}
489
490	if ((dev2unit(dev) & CLONE_UNITMASK) > TAPMAXUNIT)
491		return (ENXIO);
492
493	tp = dev->si_drv1;
494
495	mtx_lock(&tp->tap_mtx);
496	if (tp->tap_flags & TAP_OPEN) {
497		mtx_unlock(&tp->tap_mtx);
498		return (EBUSY);
499	}
500
501	bcopy(IF_LLADDR(tp->tap_ifp), tp->ether_addr, sizeof(tp->ether_addr));
502	tp->tap_pid = td->td_proc->p_pid;
503	tp->tap_flags |= TAP_OPEN;
504	ifp = tp->tap_ifp;
505
506	ifp->if_drv_flags |= IFF_DRV_RUNNING;
507	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
508	if (tapuponopen)
509		ifp->if_flags |= IFF_UP;
510	if_link_state_change(ifp, LINK_STATE_UP);
511	mtx_unlock(&tp->tap_mtx);
512
513	TAPDEBUG("%s is open. minor = %#x\n", ifp->if_xname, dev2unit(dev));
514
515	return (0);
516} /* tapopen */
517
518
519/*
520 * tapclose
521 *
522 * close the device - mark i/f down & delete routing info
523 */
524static int
525tapclose(struct cdev *dev, int foo, int bar, struct thread *td)
526{
527	struct ifaddr		*ifa;
528	struct tap_softc	*tp = dev->si_drv1;
529	struct ifnet		*ifp = tp->tap_ifp;
530
531	/* junk all pending output */
532	mtx_lock(&tp->tap_mtx);
533	CURVNET_SET(ifp->if_vnet);
534	IF_DRAIN(&ifp->if_snd);
535
536	/*
537	 * do not bring the interface down, and do not anything with
538	 * interface, if we are in VMnet mode. just close the device.
539	 */
540
541	if (((tp->tap_flags & TAP_VMNET) == 0) && (ifp->if_flags & IFF_UP)) {
542		mtx_unlock(&tp->tap_mtx);
543		if_down(ifp);
544		mtx_lock(&tp->tap_mtx);
545		if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
546			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
547			mtx_unlock(&tp->tap_mtx);
548			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
549				rtinit(ifa, (int)RTM_DELETE, 0);
550			}
551			if_purgeaddrs(ifp);
552			mtx_lock(&tp->tap_mtx);
553		}
554	}
555
556	if_link_state_change(ifp, LINK_STATE_DOWN);
557	CURVNET_RESTORE();
558
559	funsetown(&tp->tap_sigio);
560	selwakeuppri(&tp->tap_rsel, PZERO+1);
561	KNOTE_LOCKED(&tp->tap_rsel.si_note, 0);
562
563	tp->tap_flags &= ~TAP_OPEN;
564	tp->tap_pid = 0;
565	mtx_unlock(&tp->tap_mtx);
566
567	TAPDEBUG("%s is closed. minor = %#x\n",
568		ifp->if_xname, dev2unit(dev));
569
570	return (0);
571} /* tapclose */
572
573
574/*
575 * tapifinit
576 *
577 * network interface initialization function
578 */
579static void
580tapifinit(void *xtp)
581{
582	struct tap_softc	*tp = (struct tap_softc *)xtp;
583	struct ifnet		*ifp = tp->tap_ifp;
584
585	TAPDEBUG("initializing %s\n", ifp->if_xname);
586
587	mtx_lock(&tp->tap_mtx);
588	ifp->if_drv_flags |= IFF_DRV_RUNNING;
589	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
590	mtx_unlock(&tp->tap_mtx);
591
592	/* attempt to start output */
593	tapifstart(ifp);
594} /* tapifinit */
595
596
597/*
598 * tapifioctl
599 *
600 * Process an ioctl request on network interface
601 */
602static int
603tapifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
604{
605	struct tap_softc	*tp = ifp->if_softc;
606	struct ifreq		*ifr = (struct ifreq *)data;
607	struct ifstat		*ifs = NULL;
608	struct ifmediareq	*ifmr = NULL;
609	int			 dummy, error = 0;
610
611	switch (cmd) {
612		case SIOCSIFFLAGS: /* XXX -- just like vmnet does */
613		case SIOCADDMULTI:
614		case SIOCDELMULTI:
615			break;
616
617		case SIOCGIFMEDIA:
618			ifmr = (struct ifmediareq *)data;
619			dummy = ifmr->ifm_count;
620			ifmr->ifm_count = 1;
621			ifmr->ifm_status = IFM_AVALID;
622			ifmr->ifm_active = IFM_ETHER;
623			if (tp->tap_flags & TAP_OPEN)
624				ifmr->ifm_status |= IFM_ACTIVE;
625			ifmr->ifm_current = ifmr->ifm_active;
626			if (dummy >= 1) {
627				int media = IFM_ETHER;
628				error = copyout(&media, ifmr->ifm_ulist,
629				    sizeof(int));
630			}
631			break;
632
633		case SIOCSIFMTU:
634			ifp->if_mtu = ifr->ifr_mtu;
635			break;
636
637		case SIOCGIFSTATUS:
638			ifs = (struct ifstat *)data;
639			dummy = strlen(ifs->ascii);
640			mtx_lock(&tp->tap_mtx);
641			if (tp->tap_pid != 0 && dummy < sizeof(ifs->ascii))
642				snprintf(ifs->ascii + dummy,
643					sizeof(ifs->ascii) - dummy,
644					"\tOpened by PID %d\n", tp->tap_pid);
645			mtx_unlock(&tp->tap_mtx);
646			break;
647
648		default:
649			error = ether_ioctl(ifp, cmd, data);
650			break;
651	}
652
653	return (error);
654} /* tapifioctl */
655
656
657/*
658 * tapifstart
659 *
660 * queue packets from higher level ready to put out
661 */
662static void
663tapifstart(struct ifnet *ifp)
664{
665	struct tap_softc	*tp = ifp->if_softc;
666
667	TAPDEBUG("%s starting\n", ifp->if_xname);
668
669	/*
670	 * do not junk pending output if we are in VMnet mode.
671	 * XXX: can this do any harm because of queue overflow?
672	 */
673
674	mtx_lock(&tp->tap_mtx);
675	if (((tp->tap_flags & TAP_VMNET) == 0) &&
676	    ((tp->tap_flags & TAP_READY) != TAP_READY)) {
677		struct mbuf *m;
678
679		/* Unlocked read. */
680		TAPDEBUG("%s not ready, tap_flags = 0x%x\n", ifp->if_xname,
681		    tp->tap_flags);
682
683		for (;;) {
684			IF_DEQUEUE(&ifp->if_snd, m);
685			if (m != NULL) {
686				m_freem(m);
687				ifp->if_oerrors++;
688			} else
689				break;
690		}
691		mtx_unlock(&tp->tap_mtx);
692
693		return;
694	}
695
696	ifp->if_drv_flags |= IFF_DRV_OACTIVE;
697
698	if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
699		if (tp->tap_flags & TAP_RWAIT) {
700			tp->tap_flags &= ~TAP_RWAIT;
701			wakeup(tp);
702		}
703
704		if ((tp->tap_flags & TAP_ASYNC) && (tp->tap_sigio != NULL)) {
705			mtx_unlock(&tp->tap_mtx);
706			pgsigio(&tp->tap_sigio, SIGIO, 0);
707			mtx_lock(&tp->tap_mtx);
708		}
709
710		selwakeuppri(&tp->tap_rsel, PZERO+1);
711		KNOTE_LOCKED(&tp->tap_rsel.si_note, 0);
712		ifp->if_opackets ++; /* obytes are counted in ether_output */
713	}
714
715	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
716	mtx_unlock(&tp->tap_mtx);
717} /* tapifstart */
718
719
720/*
721 * tapioctl
722 *
723 * the cdevsw interface is now pretty minimal
724 */
725static int
726tapioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
727{
728	struct tap_softc	*tp = dev->si_drv1;
729	struct ifnet		*ifp = tp->tap_ifp;
730	struct tapinfo		*tapp = NULL;
731	int			 f;
732#if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
733    defined(COMPAT_FREEBSD4)
734	int			 ival;
735#endif
736
737	switch (cmd) {
738		case TAPSIFINFO:
739			tapp = (struct tapinfo *)data;
740			mtx_lock(&tp->tap_mtx);
741			ifp->if_mtu = tapp->mtu;
742			ifp->if_type = tapp->type;
743			ifp->if_baudrate = tapp->baudrate;
744			mtx_unlock(&tp->tap_mtx);
745			break;
746
747		case TAPGIFINFO:
748			tapp = (struct tapinfo *)data;
749			mtx_lock(&tp->tap_mtx);
750			tapp->mtu = ifp->if_mtu;
751			tapp->type = ifp->if_type;
752			tapp->baudrate = ifp->if_baudrate;
753			mtx_unlock(&tp->tap_mtx);
754			break;
755
756		case TAPSDEBUG:
757			tapdebug = *(int *)data;
758			break;
759
760		case TAPGDEBUG:
761			*(int *)data = tapdebug;
762			break;
763
764		case TAPGIFNAME: {
765			struct ifreq	*ifr = (struct ifreq *) data;
766
767			strlcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ);
768			} break;
769
770		case FIONBIO:
771			break;
772
773		case FIOASYNC:
774			mtx_lock(&tp->tap_mtx);
775			if (*(int *)data)
776				tp->tap_flags |= TAP_ASYNC;
777			else
778				tp->tap_flags &= ~TAP_ASYNC;
779			mtx_unlock(&tp->tap_mtx);
780			break;
781
782		case FIONREAD:
783			if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
784				struct mbuf *mb;
785
786				IFQ_LOCK(&ifp->if_snd);
787				IFQ_POLL_NOLOCK(&ifp->if_snd, mb);
788				for (*(int *)data = 0; mb != NULL;
789				     mb = mb->m_next)
790					*(int *)data += mb->m_len;
791				IFQ_UNLOCK(&ifp->if_snd);
792			} else
793				*(int *)data = 0;
794			break;
795
796		case FIOSETOWN:
797			return (fsetown(*(int *)data, &tp->tap_sigio));
798
799		case FIOGETOWN:
800			*(int *)data = fgetown(&tp->tap_sigio);
801			return (0);
802
803		/* this is deprecated, FIOSETOWN should be used instead */
804		case TIOCSPGRP:
805			return (fsetown(-(*(int *)data), &tp->tap_sigio));
806
807		/* this is deprecated, FIOGETOWN should be used instead */
808		case TIOCGPGRP:
809			*(int *)data = -fgetown(&tp->tap_sigio);
810			return (0);
811
812		/* VMware/VMnet port ioctl's */
813
814#if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
815    defined(COMPAT_FREEBSD4)
816		case _IO('V', 0):
817			ival = IOCPARM_IVAL(data);
818			data = (caddr_t)&ival;
819			/* FALLTHROUGH */
820#endif
821		case VMIO_SIOCSIFFLAGS: /* VMware/VMnet SIOCSIFFLAGS */
822			f = *(int *)data;
823			f &= 0x0fff;
824			f &= ~IFF_CANTCHANGE;
825			f |= IFF_UP;
826
827			mtx_lock(&tp->tap_mtx);
828			ifp->if_flags = f | (ifp->if_flags & IFF_CANTCHANGE);
829			mtx_unlock(&tp->tap_mtx);
830			break;
831
832		case OSIOCGIFADDR:	/* get MAC address of the remote side */
833		case SIOCGIFADDR:
834			mtx_lock(&tp->tap_mtx);
835			bcopy(tp->ether_addr, data, sizeof(tp->ether_addr));
836			mtx_unlock(&tp->tap_mtx);
837			break;
838
839		case SIOCSIFADDR:	/* set MAC address of the remote side */
840			mtx_lock(&tp->tap_mtx);
841			bcopy(data, tp->ether_addr, sizeof(tp->ether_addr));
842			mtx_unlock(&tp->tap_mtx);
843			break;
844
845		default:
846			return (ENOTTY);
847	}
848	return (0);
849} /* tapioctl */
850
851
852/*
853 * tapread
854 *
855 * the cdevsw read interface - reads a packet at a time, or at
856 * least as much of a packet as can be read
857 */
858static int
859tapread(struct cdev *dev, struct uio *uio, int flag)
860{
861	struct tap_softc	*tp = dev->si_drv1;
862	struct ifnet		*ifp = tp->tap_ifp;
863	struct mbuf		*m = NULL;
864	int			 error = 0, len;
865
866	TAPDEBUG("%s reading, minor = %#x\n", ifp->if_xname, dev2unit(dev));
867
868	mtx_lock(&tp->tap_mtx);
869	if ((tp->tap_flags & TAP_READY) != TAP_READY) {
870		mtx_unlock(&tp->tap_mtx);
871
872		/* Unlocked read. */
873		TAPDEBUG("%s not ready. minor = %#x, tap_flags = 0x%x\n",
874			ifp->if_xname, dev2unit(dev), tp->tap_flags);
875
876		return (EHOSTDOWN);
877	}
878
879	tp->tap_flags &= ~TAP_RWAIT;
880
881	/* sleep until we get a packet */
882	do {
883		IF_DEQUEUE(&ifp->if_snd, m);
884
885		if (m == NULL) {
886			if (flag & O_NONBLOCK) {
887				mtx_unlock(&tp->tap_mtx);
888				return (EWOULDBLOCK);
889			}
890
891			tp->tap_flags |= TAP_RWAIT;
892			error = mtx_sleep(tp, &tp->tap_mtx, PCATCH | (PZERO + 1),
893			    "taprd", 0);
894			if (error) {
895				mtx_unlock(&tp->tap_mtx);
896				return (error);
897			}
898		}
899	} while (m == NULL);
900	mtx_unlock(&tp->tap_mtx);
901
902	/* feed packet to bpf */
903	BPF_MTAP(ifp, m);
904
905	/* xfer packet to user space */
906	while ((m != NULL) && (uio->uio_resid > 0) && (error == 0)) {
907		len = min(uio->uio_resid, m->m_len);
908		if (len == 0)
909			break;
910
911		error = uiomove(mtod(m, void *), len, uio);
912		m = m_free(m);
913	}
914
915	if (m != NULL) {
916		TAPDEBUG("%s dropping mbuf, minor = %#x\n", ifp->if_xname,
917			dev2unit(dev));
918		m_freem(m);
919	}
920
921	return (error);
922} /* tapread */
923
924
925/*
926 * tapwrite
927 *
928 * the cdevsw write interface - an atomic write is a packet - or else!
929 */
930static int
931tapwrite(struct cdev *dev, struct uio *uio, int flag)
932{
933	struct ether_header	*eh;
934	struct tap_softc	*tp = dev->si_drv1;
935	struct ifnet		*ifp = tp->tap_ifp;
936	struct mbuf		*m;
937
938	TAPDEBUG("%s writing, minor = %#x\n",
939		ifp->if_xname, dev2unit(dev));
940
941	if (uio->uio_resid == 0)
942		return (0);
943
944	if ((uio->uio_resid < 0) || (uio->uio_resid > TAPMRU)) {
945		TAPDEBUG("%s invalid packet len = %zd, minor = %#x\n",
946			ifp->if_xname, uio->uio_resid, dev2unit(dev));
947
948		return (EIO);
949	}
950
951	if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, ETHER_ALIGN,
952	    M_PKTHDR)) == NULL) {
953		ifp->if_ierrors ++;
954		return (ENOBUFS);
955	}
956
957	m->m_pkthdr.rcvif = ifp;
958
959	/*
960	 * Only pass a unicast frame to ether_input(), if it would actually
961	 * have been received by non-virtual hardware.
962	 */
963	if (m->m_len < sizeof(struct ether_header)) {
964		m_freem(m);
965		return (0);
966	}
967	eh = mtod(m, struct ether_header *);
968
969	if (eh && (ifp->if_flags & IFF_PROMISC) == 0 &&
970	    !ETHER_IS_MULTICAST(eh->ether_dhost) &&
971	    bcmp(eh->ether_dhost, IF_LLADDR(ifp), ETHER_ADDR_LEN) != 0) {
972		m_freem(m);
973		return (0);
974	}
975
976	/* Pass packet up to parent. */
977	CURVNET_SET(ifp->if_vnet);
978	(*ifp->if_input)(ifp, m);
979	CURVNET_RESTORE();
980	ifp->if_ipackets ++; /* ibytes are counted in parent */
981
982	return (0);
983} /* tapwrite */
984
985
986/*
987 * tappoll
988 *
989 * the poll interface, this is only useful on reads
990 * really. the write detect always returns true, write never blocks
991 * anyway, it either accepts the packet or drops it
992 */
993static int
994tappoll(struct cdev *dev, int events, struct thread *td)
995{
996	struct tap_softc	*tp = dev->si_drv1;
997	struct ifnet		*ifp = tp->tap_ifp;
998	int			 revents = 0;
999
1000	TAPDEBUG("%s polling, minor = %#x\n",
1001		ifp->if_xname, dev2unit(dev));
1002
1003	if (events & (POLLIN | POLLRDNORM)) {
1004		IFQ_LOCK(&ifp->if_snd);
1005		if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
1006			TAPDEBUG("%s have data in queue. len = %d, " \
1007				"minor = %#x\n", ifp->if_xname,
1008				ifp->if_snd.ifq_len, dev2unit(dev));
1009
1010			revents |= (events & (POLLIN | POLLRDNORM));
1011		} else {
1012			TAPDEBUG("%s waiting for data, minor = %#x\n",
1013				ifp->if_xname, dev2unit(dev));
1014
1015			selrecord(td, &tp->tap_rsel);
1016		}
1017		IFQ_UNLOCK(&ifp->if_snd);
1018	}
1019
1020	if (events & (POLLOUT | POLLWRNORM))
1021		revents |= (events & (POLLOUT | POLLWRNORM));
1022
1023	return (revents);
1024} /* tappoll */
1025
1026
1027/*
1028 * tap_kqfilter
1029 *
1030 * support for kevent() system call
1031 */
1032static int
1033tapkqfilter(struct cdev *dev, struct knote *kn)
1034{
1035	struct tap_softc	*tp = dev->si_drv1;
1036	struct ifnet		*ifp = tp->tap_ifp;
1037
1038	switch (kn->kn_filter) {
1039	case EVFILT_READ:
1040		TAPDEBUG("%s kqfilter: EVFILT_READ, minor = %#x\n",
1041			ifp->if_xname, dev2unit(dev));
1042		kn->kn_fop = &tap_read_filterops;
1043		break;
1044
1045	case EVFILT_WRITE:
1046		TAPDEBUG("%s kqfilter: EVFILT_WRITE, minor = %#x\n",
1047			ifp->if_xname, dev2unit(dev));
1048		kn->kn_fop = &tap_write_filterops;
1049		break;
1050
1051	default:
1052		TAPDEBUG("%s kqfilter: invalid filter, minor = %#x\n",
1053			ifp->if_xname, dev2unit(dev));
1054		return (EINVAL);
1055		/* NOT REACHED */
1056	}
1057
1058	kn->kn_hook = tp;
1059	knlist_add(&tp->tap_rsel.si_note, kn, 0);
1060
1061	return (0);
1062} /* tapkqfilter */
1063
1064
1065/*
1066 * tap_kqread
1067 *
1068 * Return true if there is data in the interface queue
1069 */
1070static int
1071tapkqread(struct knote *kn, long hint)
1072{
1073	int			 ret;
1074	struct tap_softc	*tp = kn->kn_hook;
1075	struct cdev		*dev = tp->tap_dev;
1076	struct ifnet		*ifp = tp->tap_ifp;
1077
1078	if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) {
1079		TAPDEBUG("%s have data in queue. len = %d, minor = %#x\n",
1080			ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev));
1081		ret = 1;
1082	} else {
1083		TAPDEBUG("%s waiting for data, minor = %#x\n",
1084			ifp->if_xname, dev2unit(dev));
1085		ret = 0;
1086	}
1087
1088	return (ret);
1089} /* tapkqread */
1090
1091
1092/*
1093 * tap_kqwrite
1094 *
1095 * Always can write. Return the MTU in kn->data
1096 */
1097static int
1098tapkqwrite(struct knote *kn, long hint)
1099{
1100	struct tap_softc	*tp = kn->kn_hook;
1101	struct ifnet		*ifp = tp->tap_ifp;
1102
1103	kn->kn_data = ifp->if_mtu;
1104
1105	return (1);
1106} /* tapkqwrite */
1107
1108
1109static void
1110tapkqdetach(struct knote *kn)
1111{
1112	struct tap_softc	*tp = kn->kn_hook;
1113
1114	knlist_remove(&tp->tap_rsel.si_note, kn, 0);
1115} /* tapkqdetach */
1116
1117