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: stable/11/sys/net/if_tap.c 348126 2019-05-22 22:56:05Z kevans $
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/lock.h>
44#include <sys/fcntl.h>
45#include <sys/filio.h>
46#include <sys/jail.h>
47#include <sys/kernel.h>
48#include <sys/malloc.h>
49#include <sys/mbuf.h>
50#include <sys/module.h>
51#include <sys/poll.h>
52#include <sys/priv.h>
53#include <sys/proc.h>
54#include <sys/selinfo.h>
55#include <sys/signalvar.h>
56#include <sys/socket.h>
57#include <sys/sockio.h>
58#include <sys/sx.h>
59#include <sys/sysctl.h>
60#include <sys/systm.h>
61#include <sys/ttycom.h>
62#include <sys/uio.h>
63#include <sys/queue.h>
64
65#include <net/bpf.h>
66#include <net/ethernet.h>
67#include <net/if.h>
68#include <net/if_var.h>
69#include <net/if_clone.h>
70#include <net/if_dl.h>
71#include <net/if_media.h>
72#include <net/if_types.h>
73#include <net/route.h>
74#include <net/vnet.h>
75
76#include <netinet/in.h>
77
78#include <net/if_tapvar.h>
79#include <net/if_tap.h>
80
81
82#define CDEV_NAME	"tap"
83#define TAPDEBUG	if (tapdebug) printf
84
85static const char tapname[] = "tap";
86static const char vmnetname[] = "vmnet";
87#define TAPMAXUNIT	0x7fff
88#define VMNET_DEV_MASK	CLONE_FLAG0
89
90/* module */
91static int		tapmodevent(module_t, int, void *);
92
93/* device */
94static void		tapclone(void *, struct ucred *, char *, int,
95			    struct cdev **);
96static void		tapcreate(struct cdev *);
97
98/* network interface */
99static void		tapifstart(struct ifnet *);
100static int		tapifioctl(struct ifnet *, u_long, caddr_t);
101static void		tapifinit(void *);
102
103static int		tap_clone_create(struct if_clone *, int, caddr_t);
104static void		tap_clone_destroy(struct ifnet *);
105static struct if_clone *tap_cloner;
106static int		vmnet_clone_create(struct if_clone *, int, caddr_t);
107static void		vmnet_clone_destroy(struct ifnet *);
108static struct if_clone *vmnet_cloner;
109
110/* character device */
111static d_open_t		tapopen;
112static d_close_t	tapclose;
113static d_read_t		tapread;
114static d_write_t	tapwrite;
115static d_ioctl_t	tapioctl;
116static d_poll_t		tappoll;
117static d_kqfilter_t	tapkqfilter;
118
119/* kqueue(2) */
120static int		tapkqread(struct knote *, long);
121static int		tapkqwrite(struct knote *, long);
122static void		tapkqdetach(struct knote *);
123
124static struct filterops	tap_read_filterops = {
125	.f_isfd =	1,
126	.f_attach =	NULL,
127	.f_detach =	tapkqdetach,
128	.f_event =	tapkqread,
129};
130
131static struct filterops	tap_write_filterops = {
132	.f_isfd =	1,
133	.f_attach =	NULL,
134	.f_detach =	tapkqdetach,
135	.f_event =	tapkqwrite,
136};
137
138static struct cdevsw	tap_cdevsw = {
139	.d_version =	D_VERSION,
140	.d_flags =	D_NEEDMINOR,
141	.d_open =	tapopen,
142	.d_close =	tapclose,
143	.d_read =	tapread,
144	.d_write =	tapwrite,
145	.d_ioctl =	tapioctl,
146	.d_poll =	tappoll,
147	.d_name =	CDEV_NAME,
148	.d_kqfilter =	tapkqfilter,
149};
150
151/*
152 * All global variables in if_tap.c are locked with tapmtx, with the
153 * exception of tapdebug, which is accessed unlocked; tapclones is
154 * static at runtime.
155 */
156static struct mtx		tapmtx;
157static int			tapdebug = 0;        /* debug flag   */
158static int			tapuopen = 0;        /* allow user open() */
159static int			tapuponopen = 0;    /* IFF_UP on open() */
160static int			tapdclone = 1;	/* enable devfs cloning */
161static SLIST_HEAD(, tap_softc)	taphead;             /* first device */
162static struct clonedevs 	*tapclones;
163
164MALLOC_DECLARE(M_TAP);
165MALLOC_DEFINE(M_TAP, CDEV_NAME, "Ethernet tunnel interface");
166SYSCTL_INT(_debug, OID_AUTO, if_tap_debug, CTLFLAG_RW, &tapdebug, 0, "");
167
168static struct sx tap_ioctl_sx;
169SX_SYSINIT(tap_ioctl_sx, &tap_ioctl_sx, "tap_ioctl");
170
171SYSCTL_DECL(_net_link);
172static SYSCTL_NODE(_net_link, OID_AUTO, tap, CTLFLAG_RW, 0,
173    "Ethernet tunnel software network interface");
174SYSCTL_INT(_net_link_tap, OID_AUTO, user_open, CTLFLAG_RW, &tapuopen, 0,
175	"Allow user to open /dev/tap (based on node permissions)");
176SYSCTL_INT(_net_link_tap, OID_AUTO, up_on_open, CTLFLAG_RW, &tapuponopen, 0,
177	"Bring interface up when /dev/tap is opened");
178SYSCTL_INT(_net_link_tap, OID_AUTO, devfs_cloning, CTLFLAG_RWTUN, &tapdclone, 0,
179	"Enable legacy devfs interface creation");
180SYSCTL_INT(_net_link_tap, OID_AUTO, debug, CTLFLAG_RW, &tapdebug, 0, "");
181
182DEV_MODULE(if_tap, tapmodevent, NULL);
183MODULE_VERSION(if_tap, 1);
184
185static int
186tap_clone_create(struct if_clone *ifc, int unit, caddr_t params)
187{
188	struct cdev *dev;
189	int i;
190
191	/* Find any existing device, or allocate new unit number. */
192	i = clone_create(&tapclones, &tap_cdevsw, &unit, &dev, 0);
193	if (i) {
194		dev = make_dev(&tap_cdevsw, unit, UID_ROOT, GID_WHEEL, 0600,
195		    "%s%d", tapname, unit);
196	}
197
198	tapcreate(dev);
199	return (0);
200}
201
202/* vmnet devices are tap devices in disguise */
203static int
204vmnet_clone_create(struct if_clone *ifc, int unit, caddr_t params)
205{
206	struct cdev *dev;
207	int i;
208
209	/* Find any existing device, or allocate new unit number. */
210	i = clone_create(&tapclones, &tap_cdevsw, &unit, &dev, VMNET_DEV_MASK);
211	if (i) {
212		dev = make_dev(&tap_cdevsw, unit | VMNET_DEV_MASK, UID_ROOT,
213		    GID_WHEEL, 0600, "%s%d", vmnetname, unit);
214	}
215
216	tapcreate(dev);
217	return (0);
218}
219
220static void
221tap_destroy(struct tap_softc *tp)
222{
223	struct ifnet *ifp = tp->tap_ifp;
224
225	CURVNET_SET(ifp->if_vnet);
226
227	destroy_dev(tp->tap_dev);
228	seldrain(&tp->tap_rsel);
229	knlist_clear(&tp->tap_rsel.si_note, 0);
230	knlist_destroy(&tp->tap_rsel.si_note);
231	ether_ifdetach(ifp);
232
233	sx_xlock(&tap_ioctl_sx);
234	ifp->if_softc = NULL;
235	sx_xunlock(&tap_ioctl_sx);
236
237	if_free(ifp);
238
239	mtx_destroy(&tp->tap_mtx);
240	free(tp, M_TAP);
241	CURVNET_RESTORE();
242}
243
244static void
245tap_clone_destroy(struct ifnet *ifp)
246{
247	struct tap_softc *tp = ifp->if_softc;
248
249	mtx_lock(&tapmtx);
250	SLIST_REMOVE(&taphead, tp, tap_softc, tap_next);
251	mtx_unlock(&tapmtx);
252	tap_destroy(tp);
253}
254
255/* vmnet devices are tap devices in disguise */
256static void
257vmnet_clone_destroy(struct ifnet *ifp)
258{
259	tap_clone_destroy(ifp);
260}
261
262/*
263 * tapmodevent
264 *
265 * module event handler
266 */
267static int
268tapmodevent(module_t mod, int type, void *data)
269{
270	static eventhandler_tag	 eh_tag = NULL;
271	struct tap_softc	*tp = NULL;
272	struct ifnet		*ifp = NULL;
273
274	switch (type) {
275	case MOD_LOAD:
276
277		/* intitialize device */
278
279		mtx_init(&tapmtx, "tapmtx", NULL, MTX_DEF);
280		SLIST_INIT(&taphead);
281
282		clone_setup(&tapclones);
283		eh_tag = EVENTHANDLER_REGISTER(dev_clone, tapclone, 0, 1000);
284		if (eh_tag == NULL) {
285			clone_cleanup(&tapclones);
286			mtx_destroy(&tapmtx);
287			return (ENOMEM);
288		}
289		tap_cloner = if_clone_simple(tapname, tap_clone_create,
290		    tap_clone_destroy, 0);
291		vmnet_cloner = if_clone_simple(vmnetname, vmnet_clone_create,
292		    vmnet_clone_destroy, 0);
293		return (0);
294
295	case MOD_UNLOAD:
296		/*
297		 * The EBUSY algorithm here can't quite atomically
298		 * guarantee that this is race-free since we have to
299		 * release the tap mtx to deregister the clone handler.
300		 */
301		mtx_lock(&tapmtx);
302		SLIST_FOREACH(tp, &taphead, tap_next) {
303			mtx_lock(&tp->tap_mtx);
304			if (tp->tap_flags & TAP_OPEN) {
305				mtx_unlock(&tp->tap_mtx);
306				mtx_unlock(&tapmtx);
307				return (EBUSY);
308			}
309			mtx_unlock(&tp->tap_mtx);
310		}
311		mtx_unlock(&tapmtx);
312
313		EVENTHANDLER_DEREGISTER(dev_clone, eh_tag);
314		if_clone_detach(tap_cloner);
315		if_clone_detach(vmnet_cloner);
316		drain_dev_clone_events();
317
318		mtx_lock(&tapmtx);
319		while ((tp = SLIST_FIRST(&taphead)) != NULL) {
320			SLIST_REMOVE_HEAD(&taphead, tap_next);
321			mtx_unlock(&tapmtx);
322
323			ifp = tp->tap_ifp;
324
325			TAPDEBUG("detaching %s\n", ifp->if_xname);
326
327			tap_destroy(tp);
328			mtx_lock(&tapmtx);
329		}
330		mtx_unlock(&tapmtx);
331		clone_cleanup(&tapclones);
332
333		mtx_destroy(&tapmtx);
334
335		break;
336
337	default:
338		return (EOPNOTSUPP);
339	}
340
341	return (0);
342} /* tapmodevent */
343
344
345/*
346 * DEVFS handler
347 *
348 * We need to support two kind of devices - tap and vmnet
349 */
350static void
351tapclone(void *arg, struct ucred *cred, char *name, int namelen, struct cdev **dev)
352{
353	char		devname[SPECNAMELEN + 1];
354	int		i, unit, append_unit;
355	int		extra;
356
357	if (*dev != NULL)
358		return;
359
360	if (!tapdclone ||
361	    (!tapuopen && priv_check_cred(cred, PRIV_NET_IFCREATE, 0) != 0))
362		return;
363
364	unit = 0;
365	append_unit = 0;
366	extra = 0;
367
368	/* We're interested in only tap/vmnet devices. */
369	if (strcmp(name, tapname) == 0) {
370		unit = -1;
371	} else if (strcmp(name, vmnetname) == 0) {
372		unit = -1;
373		extra = VMNET_DEV_MASK;
374	} else if (dev_stdclone(name, NULL, tapname, &unit) != 1) {
375		if (dev_stdclone(name, NULL, vmnetname, &unit) != 1) {
376			return;
377		} else {
378			extra = VMNET_DEV_MASK;
379		}
380	}
381
382	if (unit == -1)
383		append_unit = 1;
384
385	CURVNET_SET(CRED_TO_VNET(cred));
386	/* find any existing device, or allocate new unit number */
387	i = clone_create(&tapclones, &tap_cdevsw, &unit, dev, extra);
388	if (i) {
389		if (append_unit) {
390			/*
391			 * We were passed 'tun' or 'tap', with no unit specified
392			 * so we'll need to append it now.
393			 */
394			namelen = snprintf(devname, sizeof(devname), "%s%d", name,
395			    unit);
396			name = devname;
397		}
398
399		*dev = make_dev_credf(MAKEDEV_REF, &tap_cdevsw, unit | extra,
400		     cred, UID_ROOT, GID_WHEEL, 0600, "%s", name);
401	}
402
403	if_clone_create(name, namelen, NULL);
404	CURVNET_RESTORE();
405} /* tapclone */
406
407
408/*
409 * tapcreate
410 *
411 * to create interface
412 */
413static void
414tapcreate(struct cdev *dev)
415{
416	struct ifnet		*ifp = NULL;
417	struct tap_softc	*tp = NULL;
418	unsigned short		 macaddr_hi;
419	uint32_t		 macaddr_mid;
420	int			 unit;
421	const char		*name = NULL;
422	u_char			eaddr[6];
423
424	/* allocate driver storage and create device */
425	tp = malloc(sizeof(*tp), M_TAP, M_WAITOK | M_ZERO);
426	mtx_init(&tp->tap_mtx, "tap_mtx", NULL, MTX_DEF);
427	mtx_lock(&tapmtx);
428	SLIST_INSERT_HEAD(&taphead, tp, tap_next);
429	mtx_unlock(&tapmtx);
430
431	unit = dev2unit(dev);
432
433	/* select device: tap or vmnet */
434	if (unit & VMNET_DEV_MASK) {
435		name = vmnetname;
436		tp->tap_flags |= TAP_VMNET;
437	} else
438		name = tapname;
439
440	unit &= TAPMAXUNIT;
441
442	TAPDEBUG("tapcreate(%s%d). minor = %#x\n", name, unit, dev2unit(dev));
443
444	/* generate fake MAC address: 00 bd xx xx xx unit_no */
445	macaddr_hi = htons(0x00bd);
446	macaddr_mid = (uint32_t) ticks;
447	bcopy(&macaddr_hi, eaddr, sizeof(short));
448	bcopy(&macaddr_mid, &eaddr[2], sizeof(uint32_t));
449	eaddr[5] = (u_char)unit;
450
451	/* fill the rest and attach interface */
452	ifp = tp->tap_ifp = if_alloc(IFT_ETHER);
453	if (ifp == NULL)
454		panic("%s%d: can not if_alloc()", name, unit);
455	ifp->if_softc = tp;
456	if_initname(ifp, name, unit);
457	ifp->if_init = tapifinit;
458	ifp->if_start = tapifstart;
459	ifp->if_ioctl = tapifioctl;
460	ifp->if_mtu = ETHERMTU;
461	ifp->if_flags = (IFF_BROADCAST|IFF_SIMPLEX|IFF_MULTICAST);
462	IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
463	ifp->if_capabilities |= IFCAP_LINKSTATE;
464	ifp->if_capenable |= IFCAP_LINKSTATE;
465
466	dev->si_drv1 = tp;
467	tp->tap_dev = dev;
468
469	ether_ifattach(ifp, eaddr);
470
471	mtx_lock(&tp->tap_mtx);
472	tp->tap_flags |= TAP_INITED;
473	mtx_unlock(&tp->tap_mtx);
474
475	knlist_init_mtx(&tp->tap_rsel.si_note, &tp->tap_mtx);
476
477	TAPDEBUG("interface %s is created. minor = %#x\n",
478		ifp->if_xname, dev2unit(dev));
479} /* tapcreate */
480
481
482/*
483 * tapopen
484 *
485 * to open tunnel. must be superuser
486 */
487static int
488tapopen(struct cdev *dev, int flag, int mode, struct thread *td)
489{
490	struct tap_softc	*tp = NULL;
491	struct ifnet		*ifp = NULL;
492	int			 error;
493
494	if (tapuopen == 0) {
495		error = priv_check(td, PRIV_NET_TAP);
496		if (error)
497			return (error);
498	}
499
500	if ((dev2unit(dev) & CLONE_UNITMASK) > TAPMAXUNIT)
501		return (ENXIO);
502
503	tp = dev->si_drv1;
504
505	mtx_lock(&tp->tap_mtx);
506	if (tp->tap_flags & TAP_OPEN) {
507		mtx_unlock(&tp->tap_mtx);
508		return (EBUSY);
509	}
510
511	bcopy(IF_LLADDR(tp->tap_ifp), tp->ether_addr, sizeof(tp->ether_addr));
512	tp->tap_pid = td->td_proc->p_pid;
513	tp->tap_flags |= TAP_OPEN;
514	ifp = tp->tap_ifp;
515
516	ifp->if_drv_flags |= IFF_DRV_RUNNING;
517	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
518	if (tapuponopen)
519		ifp->if_flags |= IFF_UP;
520	if_link_state_change(ifp, LINK_STATE_UP);
521	mtx_unlock(&tp->tap_mtx);
522
523	TAPDEBUG("%s is open. minor = %#x\n", ifp->if_xname, dev2unit(dev));
524
525	return (0);
526} /* tapopen */
527
528
529/*
530 * tapclose
531 *
532 * close the device - mark i/f down & delete routing info
533 */
534static int
535tapclose(struct cdev *dev, int foo, int bar, struct thread *td)
536{
537	struct ifaddr		*ifa;
538	struct tap_softc	*tp = dev->si_drv1;
539	struct ifnet		*ifp = tp->tap_ifp;
540
541	/* junk all pending output */
542	mtx_lock(&tp->tap_mtx);
543	CURVNET_SET(ifp->if_vnet);
544	IF_DRAIN(&ifp->if_snd);
545
546	/*
547	 * Do not bring the interface down, and do not anything with
548	 * interface, if we are in VMnet mode. Just close the device.
549	 */
550	if (((tp->tap_flags & TAP_VMNET) == 0) &&
551	    (ifp->if_flags & (IFF_UP | IFF_LINK0)) == IFF_UP) {
552		mtx_unlock(&tp->tap_mtx);
553		if_down(ifp);
554		mtx_lock(&tp->tap_mtx);
555		if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
556			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
557			mtx_unlock(&tp->tap_mtx);
558			TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
559				rtinit(ifa, (int)RTM_DELETE, 0);
560			}
561			if_purgeaddrs(ifp);
562			mtx_lock(&tp->tap_mtx);
563		}
564	}
565
566	if_link_state_change(ifp, LINK_STATE_DOWN);
567	CURVNET_RESTORE();
568
569	funsetown(&tp->tap_sigio);
570	selwakeuppri(&tp->tap_rsel, PZERO+1);
571	KNOTE_LOCKED(&tp->tap_rsel.si_note, 0);
572
573	tp->tap_flags &= ~TAP_OPEN;
574	tp->tap_pid = 0;
575	mtx_unlock(&tp->tap_mtx);
576
577	TAPDEBUG("%s is closed. minor = %#x\n",
578		ifp->if_xname, dev2unit(dev));
579
580	return (0);
581} /* tapclose */
582
583
584/*
585 * tapifinit
586 *
587 * network interface initialization function
588 */
589static void
590tapifinit(void *xtp)
591{
592	struct tap_softc	*tp = (struct tap_softc *)xtp;
593	struct ifnet		*ifp = tp->tap_ifp;
594
595	TAPDEBUG("initializing %s\n", ifp->if_xname);
596
597	mtx_lock(&tp->tap_mtx);
598	ifp->if_drv_flags |= IFF_DRV_RUNNING;
599	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
600	mtx_unlock(&tp->tap_mtx);
601
602	/* attempt to start output */
603	tapifstart(ifp);
604} /* tapifinit */
605
606
607/*
608 * tapifioctl
609 *
610 * Process an ioctl request on network interface
611 */
612static int
613tapifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
614{
615	struct tap_softc	*tp;
616	struct ifreq		*ifr = (struct ifreq *)data;
617	struct ifstat		*ifs = NULL;
618	struct ifmediareq	*ifmr = NULL;
619	int			 dummy, error = 0;
620
621	sx_xlock(&tap_ioctl_sx);
622	tp = ifp->if_softc;
623	if (tp == NULL) {
624		error = ENXIO;
625		goto bad;
626	}
627	switch (cmd) {
628		case SIOCSIFFLAGS: /* XXX -- just like vmnet does */
629		case SIOCADDMULTI:
630		case SIOCDELMULTI:
631			break;
632
633		case SIOCGIFMEDIA:
634			ifmr = (struct ifmediareq *)data;
635			dummy = ifmr->ifm_count;
636			ifmr->ifm_count = 1;
637			ifmr->ifm_status = IFM_AVALID;
638			ifmr->ifm_active = IFM_ETHER;
639			if (tp->tap_flags & TAP_OPEN)
640				ifmr->ifm_status |= IFM_ACTIVE;
641			ifmr->ifm_current = ifmr->ifm_active;
642			if (dummy >= 1) {
643				int media = IFM_ETHER;
644				error = copyout(&media, ifmr->ifm_ulist,
645				    sizeof(int));
646			}
647			break;
648
649		case SIOCSIFMTU:
650			ifp->if_mtu = ifr->ifr_mtu;
651			break;
652
653		case SIOCGIFSTATUS:
654			ifs = (struct ifstat *)data;
655			mtx_lock(&tp->tap_mtx);
656			if (tp->tap_pid != 0)
657				snprintf(ifs->ascii, sizeof(ifs->ascii),
658					"\tOpened by PID %d\n", tp->tap_pid);
659			else
660				ifs->ascii[0] = '\0';
661			mtx_unlock(&tp->tap_mtx);
662			break;
663
664		default:
665			error = ether_ioctl(ifp, cmd, data);
666			break;
667	}
668
669bad:
670	sx_xunlock(&tap_ioctl_sx);
671	return (error);
672} /* tapifioctl */
673
674
675/*
676 * tapifstart
677 *
678 * queue packets from higher level ready to put out
679 */
680static void
681tapifstart(struct ifnet *ifp)
682{
683	struct tap_softc	*tp = ifp->if_softc;
684
685	TAPDEBUG("%s starting\n", ifp->if_xname);
686
687	/*
688	 * do not junk pending output if we are in VMnet mode.
689	 * XXX: can this do any harm because of queue overflow?
690	 */
691
692	mtx_lock(&tp->tap_mtx);
693	if (((tp->tap_flags & TAP_VMNET) == 0) &&
694	    ((tp->tap_flags & TAP_READY) != TAP_READY)) {
695		struct mbuf *m;
696
697		/* Unlocked read. */
698		TAPDEBUG("%s not ready, tap_flags = 0x%x\n", ifp->if_xname,
699		    tp->tap_flags);
700
701		for (;;) {
702			IF_DEQUEUE(&ifp->if_snd, m);
703			if (m != NULL) {
704				m_freem(m);
705				if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
706			} else
707				break;
708		}
709		mtx_unlock(&tp->tap_mtx);
710
711		return;
712	}
713
714	ifp->if_drv_flags |= IFF_DRV_OACTIVE;
715
716	if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
717		if (tp->tap_flags & TAP_RWAIT) {
718			tp->tap_flags &= ~TAP_RWAIT;
719			wakeup(tp);
720		}
721
722		if ((tp->tap_flags & TAP_ASYNC) && (tp->tap_sigio != NULL)) {
723			mtx_unlock(&tp->tap_mtx);
724			pgsigio(&tp->tap_sigio, SIGIO, 0);
725			mtx_lock(&tp->tap_mtx);
726		}
727
728		selwakeuppri(&tp->tap_rsel, PZERO+1);
729		KNOTE_LOCKED(&tp->tap_rsel.si_note, 0);
730		if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); /* obytes are counted in ether_output */
731	}
732
733	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
734	mtx_unlock(&tp->tap_mtx);
735} /* tapifstart */
736
737
738/*
739 * tapioctl
740 *
741 * the cdevsw interface is now pretty minimal
742 */
743static int
744tapioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
745{
746	struct ifreq		 ifr;
747	struct tap_softc	*tp = dev->si_drv1;
748	struct ifnet		*ifp = tp->tap_ifp;
749	struct tapinfo		*tapp = NULL;
750	int			 f;
751	int			 error;
752#if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
753    defined(COMPAT_FREEBSD4)
754	int			 ival;
755#endif
756
757	switch (cmd) {
758		case TAPSIFINFO:
759			tapp = (struct tapinfo *)data;
760			if (ifp->if_type != tapp->type)
761				return (EPROTOTYPE);
762			mtx_lock(&tp->tap_mtx);
763			if (ifp->if_mtu != tapp->mtu) {
764				strlcpy(ifr.ifr_name, if_name(ifp), IFNAMSIZ);
765				ifr.ifr_mtu = tapp->mtu;
766				CURVNET_SET(ifp->if_vnet);
767				error = ifhwioctl(SIOCSIFMTU, ifp,
768				    (caddr_t)&ifr, td);
769				CURVNET_RESTORE();
770				if (error) {
771					mtx_unlock(&tp->tap_mtx);
772					return (error);
773				}
774			}
775			ifp->if_baudrate = tapp->baudrate;
776			mtx_unlock(&tp->tap_mtx);
777			break;
778
779		case TAPGIFINFO:
780			tapp = (struct tapinfo *)data;
781			mtx_lock(&tp->tap_mtx);
782			tapp->mtu = ifp->if_mtu;
783			tapp->type = ifp->if_type;
784			tapp->baudrate = ifp->if_baudrate;
785			mtx_unlock(&tp->tap_mtx);
786			break;
787
788		case TAPSDEBUG:
789			tapdebug = *(int *)data;
790			break;
791
792		case TAPGDEBUG:
793			*(int *)data = tapdebug;
794			break;
795
796		case TAPGIFNAME: {
797			struct ifreq	*ifr = (struct ifreq *) data;
798
799			strlcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ);
800			} break;
801
802		case FIONBIO:
803			break;
804
805		case FIOASYNC:
806			mtx_lock(&tp->tap_mtx);
807			if (*(int *)data)
808				tp->tap_flags |= TAP_ASYNC;
809			else
810				tp->tap_flags &= ~TAP_ASYNC;
811			mtx_unlock(&tp->tap_mtx);
812			break;
813
814		case FIONREAD:
815			if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
816				struct mbuf *mb;
817
818				IFQ_LOCK(&ifp->if_snd);
819				IFQ_POLL_NOLOCK(&ifp->if_snd, mb);
820				for (*(int *)data = 0; mb != NULL;
821				     mb = mb->m_next)
822					*(int *)data += mb->m_len;
823				IFQ_UNLOCK(&ifp->if_snd);
824			} else
825				*(int *)data = 0;
826			break;
827
828		case FIOSETOWN:
829			return (fsetown(*(int *)data, &tp->tap_sigio));
830
831		case FIOGETOWN:
832			*(int *)data = fgetown(&tp->tap_sigio);
833			return (0);
834
835		/* this is deprecated, FIOSETOWN should be used instead */
836		case TIOCSPGRP:
837			return (fsetown(-(*(int *)data), &tp->tap_sigio));
838
839		/* this is deprecated, FIOGETOWN should be used instead */
840		case TIOCGPGRP:
841			*(int *)data = -fgetown(&tp->tap_sigio);
842			return (0);
843
844		/* VMware/VMnet port ioctl's */
845
846#if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
847    defined(COMPAT_FREEBSD4)
848		case _IO('V', 0):
849			ival = IOCPARM_IVAL(data);
850			data = (caddr_t)&ival;
851			/* FALLTHROUGH */
852#endif
853		case VMIO_SIOCSIFFLAGS: /* VMware/VMnet SIOCSIFFLAGS */
854			f = *(int *)data;
855			f &= 0x0fff;
856			f &= ~IFF_CANTCHANGE;
857			f |= IFF_UP;
858
859			mtx_lock(&tp->tap_mtx);
860			ifp->if_flags = f | (ifp->if_flags & IFF_CANTCHANGE);
861			mtx_unlock(&tp->tap_mtx);
862			break;
863
864		case SIOCGIFADDR:	/* get MAC address of the remote side */
865			mtx_lock(&tp->tap_mtx);
866			bcopy(tp->ether_addr, data, sizeof(tp->ether_addr));
867			mtx_unlock(&tp->tap_mtx);
868			break;
869
870		case SIOCSIFADDR:	/* set MAC address of the remote side */
871			mtx_lock(&tp->tap_mtx);
872			bcopy(data, tp->ether_addr, sizeof(tp->ether_addr));
873			mtx_unlock(&tp->tap_mtx);
874			break;
875
876		default:
877			return (ENOTTY);
878	}
879	return (0);
880} /* tapioctl */
881
882
883/*
884 * tapread
885 *
886 * the cdevsw read interface - reads a packet at a time, or at
887 * least as much of a packet as can be read
888 */
889static int
890tapread(struct cdev *dev, struct uio *uio, int flag)
891{
892	struct tap_softc	*tp = dev->si_drv1;
893	struct ifnet		*ifp = tp->tap_ifp;
894	struct mbuf		*m = NULL;
895	int			 error = 0, len;
896
897	TAPDEBUG("%s reading, minor = %#x\n", ifp->if_xname, dev2unit(dev));
898
899	mtx_lock(&tp->tap_mtx);
900	if ((tp->tap_flags & TAP_READY) != TAP_READY) {
901		mtx_unlock(&tp->tap_mtx);
902
903		/* Unlocked read. */
904		TAPDEBUG("%s not ready. minor = %#x, tap_flags = 0x%x\n",
905			ifp->if_xname, dev2unit(dev), tp->tap_flags);
906
907		return (EHOSTDOWN);
908	}
909
910	tp->tap_flags &= ~TAP_RWAIT;
911
912	/* sleep until we get a packet */
913	do {
914		IF_DEQUEUE(&ifp->if_snd, m);
915
916		if (m == NULL) {
917			if (flag & O_NONBLOCK) {
918				mtx_unlock(&tp->tap_mtx);
919				return (EWOULDBLOCK);
920			}
921
922			tp->tap_flags |= TAP_RWAIT;
923			error = mtx_sleep(tp, &tp->tap_mtx, PCATCH | (PZERO + 1),
924			    "taprd", 0);
925			if (error) {
926				mtx_unlock(&tp->tap_mtx);
927				return (error);
928			}
929		}
930	} while (m == NULL);
931	mtx_unlock(&tp->tap_mtx);
932
933	/* feed packet to bpf */
934	BPF_MTAP(ifp, m);
935
936	/* xfer packet to user space */
937	while ((m != NULL) && (uio->uio_resid > 0) && (error == 0)) {
938		len = min(uio->uio_resid, m->m_len);
939		if (len == 0)
940			break;
941
942		error = uiomove(mtod(m, void *), len, uio);
943		m = m_free(m);
944	}
945
946	if (m != NULL) {
947		TAPDEBUG("%s dropping mbuf, minor = %#x\n", ifp->if_xname,
948			dev2unit(dev));
949		m_freem(m);
950	}
951
952	return (error);
953} /* tapread */
954
955
956/*
957 * tapwrite
958 *
959 * the cdevsw write interface - an atomic write is a packet - or else!
960 */
961static int
962tapwrite(struct cdev *dev, struct uio *uio, int flag)
963{
964	struct ether_header	*eh;
965	struct tap_softc	*tp = dev->si_drv1;
966	struct ifnet		*ifp = tp->tap_ifp;
967	struct mbuf		*m;
968
969	TAPDEBUG("%s writing, minor = %#x\n",
970		ifp->if_xname, dev2unit(dev));
971
972	if (uio->uio_resid == 0)
973		return (0);
974
975	if ((uio->uio_resid < 0) || (uio->uio_resid > TAPMRU)) {
976		TAPDEBUG("%s invalid packet len = %zd, minor = %#x\n",
977			ifp->if_xname, uio->uio_resid, dev2unit(dev));
978
979		return (EIO);
980	}
981
982	if ((m = m_uiotombuf(uio, M_NOWAIT, 0, ETHER_ALIGN,
983	    M_PKTHDR)) == NULL) {
984		if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
985		return (ENOBUFS);
986	}
987
988	m->m_pkthdr.rcvif = ifp;
989
990	/*
991	 * Only pass a unicast frame to ether_input(), if it would actually
992	 * have been received by non-virtual hardware.
993	 */
994	if (m->m_len < sizeof(struct ether_header)) {
995		m_freem(m);
996		return (0);
997	}
998	eh = mtod(m, struct ether_header *);
999
1000	if (eh && (ifp->if_flags & IFF_PROMISC) == 0 &&
1001	    !ETHER_IS_MULTICAST(eh->ether_dhost) &&
1002	    bcmp(eh->ether_dhost, IF_LLADDR(ifp), ETHER_ADDR_LEN) != 0) {
1003		m_freem(m);
1004		return (0);
1005	}
1006
1007	/* Pass packet up to parent. */
1008	CURVNET_SET(ifp->if_vnet);
1009	(*ifp->if_input)(ifp, m);
1010	CURVNET_RESTORE();
1011	if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); /* ibytes are counted in parent */
1012
1013	return (0);
1014} /* tapwrite */
1015
1016
1017/*
1018 * tappoll
1019 *
1020 * the poll interface, this is only useful on reads
1021 * really. the write detect always returns true, write never blocks
1022 * anyway, it either accepts the packet or drops it
1023 */
1024static int
1025tappoll(struct cdev *dev, int events, struct thread *td)
1026{
1027	struct tap_softc	*tp = dev->si_drv1;
1028	struct ifnet		*ifp = tp->tap_ifp;
1029	int			 revents = 0;
1030
1031	TAPDEBUG("%s polling, minor = %#x\n",
1032		ifp->if_xname, dev2unit(dev));
1033
1034	if (events & (POLLIN | POLLRDNORM)) {
1035		IFQ_LOCK(&ifp->if_snd);
1036		if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
1037			TAPDEBUG("%s have data in queue. len = %d, " \
1038				"minor = %#x\n", ifp->if_xname,
1039				ifp->if_snd.ifq_len, dev2unit(dev));
1040
1041			revents |= (events & (POLLIN | POLLRDNORM));
1042		} else {
1043			TAPDEBUG("%s waiting for data, minor = %#x\n",
1044				ifp->if_xname, dev2unit(dev));
1045
1046			selrecord(td, &tp->tap_rsel);
1047		}
1048		IFQ_UNLOCK(&ifp->if_snd);
1049	}
1050
1051	if (events & (POLLOUT | POLLWRNORM))
1052		revents |= (events & (POLLOUT | POLLWRNORM));
1053
1054	return (revents);
1055} /* tappoll */
1056
1057
1058/*
1059 * tap_kqfilter
1060 *
1061 * support for kevent() system call
1062 */
1063static int
1064tapkqfilter(struct cdev *dev, struct knote *kn)
1065{
1066	struct tap_softc	*tp = dev->si_drv1;
1067	struct ifnet		*ifp = tp->tap_ifp;
1068
1069	switch (kn->kn_filter) {
1070	case EVFILT_READ:
1071		TAPDEBUG("%s kqfilter: EVFILT_READ, minor = %#x\n",
1072			ifp->if_xname, dev2unit(dev));
1073		kn->kn_fop = &tap_read_filterops;
1074		break;
1075
1076	case EVFILT_WRITE:
1077		TAPDEBUG("%s kqfilter: EVFILT_WRITE, minor = %#x\n",
1078			ifp->if_xname, dev2unit(dev));
1079		kn->kn_fop = &tap_write_filterops;
1080		break;
1081
1082	default:
1083		TAPDEBUG("%s kqfilter: invalid filter, minor = %#x\n",
1084			ifp->if_xname, dev2unit(dev));
1085		return (EINVAL);
1086		/* NOT REACHED */
1087	}
1088
1089	kn->kn_hook = tp;
1090	knlist_add(&tp->tap_rsel.si_note, kn, 0);
1091
1092	return (0);
1093} /* tapkqfilter */
1094
1095
1096/*
1097 * tap_kqread
1098 *
1099 * Return true if there is data in the interface queue
1100 */
1101static int
1102tapkqread(struct knote *kn, long hint)
1103{
1104	int			 ret;
1105	struct tap_softc	*tp = kn->kn_hook;
1106	struct cdev		*dev = tp->tap_dev;
1107	struct ifnet		*ifp = tp->tap_ifp;
1108
1109	if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) {
1110		TAPDEBUG("%s have data in queue. len = %d, minor = %#x\n",
1111			ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev));
1112		ret = 1;
1113	} else {
1114		TAPDEBUG("%s waiting for data, minor = %#x\n",
1115			ifp->if_xname, dev2unit(dev));
1116		ret = 0;
1117	}
1118
1119	return (ret);
1120} /* tapkqread */
1121
1122
1123/*
1124 * tap_kqwrite
1125 *
1126 * Always can write. Return the MTU in kn->data
1127 */
1128static int
1129tapkqwrite(struct knote *kn, long hint)
1130{
1131	struct tap_softc	*tp = kn->kn_hook;
1132	struct ifnet		*ifp = tp->tap_ifp;
1133
1134	kn->kn_data = ifp->if_mtu;
1135
1136	return (1);
1137} /* tapkqwrite */
1138
1139
1140static void
1141tapkqdetach(struct knote *kn)
1142{
1143	struct tap_softc	*tp = kn->kn_hook;
1144
1145	knlist_remove(&tp->tap_rsel.si_note, kn, 0);
1146} /* tapkqdetach */
1147
1148