1 /* $NetBSD: if_tun.c,v 1.14 1994/06/29 06:36:25 cgd Exp $ */
2
3 /*
4 * Copyright (c) 1988, Julian Onions <jpo@cs.nott.ac.uk>
5 * Nottingham University 1987.
6 *
7 * This source may be freely distributed, however I would be interested
8 * in any changes that are made.
9 *
10 * This driver takes packets off the IP i/f and hands them up to a
11 * user process to have its wicked way with. This driver has it's
12 * roots in a similar driver written by Phil Cockcroft (formerly) at
13 * UCL. This driver is based much more on read/write/poll mode of
14 * operation though.
15 *
16 * $FreeBSD: src/sys/net/if_tun.c,v 1.74.2.8 2002/02/13 00:43:11 dillon Exp $
17 */
18
19 #include "opt_inet.h"
20 #include "opt_inet6.h"
21
22 #include <sys/param.h>
23 #include <sys/proc.h>
24 #include <sys/caps.h>
25 #include <sys/systm.h>
26 #include <sys/mbuf.h>
27 #include <sys/socket.h>
28 #include <sys/conf.h>
29 #include <sys/device.h>
30 #include <sys/filio.h>
31 #include <sys/sockio.h>
32 #include <sys/ttycom.h>
33 #include <sys/signalvar.h>
34 #include <sys/filedesc.h>
35 #include <sys/kernel.h>
36 #include <sys/sysctl.h>
37 #include <sys/uio.h>
38 #include <sys/vnode.h>
39 #include <sys/malloc.h>
40 #include <sys/mplock2.h>
41 #include <sys/devfs.h>
42 #include <sys/queue.h>
43
44 #include <net/bpf.h>
45 #include <net/if.h>
46 #include <net/if_types.h>
47 #include <net/if_clone.h>
48 #include <net/ifq_var.h>
49 #include <net/netisr.h>
50 #include <net/route.h>
51
52 #ifdef INET
53 #include <netinet/in.h>
54 #endif
55
56 #include "if_tunvar.h"
57 #include "if_tun.h"
58
59 #define TUN "tun"
60 #define TUNDEBUG if (tundebug) if_printf
61
62 /* module */
63 static int tunmodevent(module_t, int, void *);
64
65 /* device */
66 static struct tun_softc *tuncreate(cdev_t, int);
67 static void tundestroy(struct tun_softc *sc);
68
69 /* clone */
70 static int tun_clone_create(struct if_clone *, int,
71 caddr_t, caddr_t);
72 static int tun_clone_destroy(struct ifnet *);
73
74 /* network interface */
75 static int tunifinit(struct ifnet *);
76 static void tunifstart(struct ifnet *, struct ifaltq_subque *);
77 static int tunifoutput(struct ifnet *, struct mbuf *,
78 struct sockaddr *, struct rtentry *rt);
79 static int tunifioctl(struct ifnet *, u_long,
80 caddr_t, struct ucred *);
81
82 /* character device */
83 static d_open_t tunopen;
84 static d_close_t tunclose;
85 static d_read_t tunread;
86 static d_write_t tunwrite;
87 static d_ioctl_t tunioctl;
88 static d_kqfilter_t tunkqfilter;
89 static d_clone_t tunclone;
90
91 static struct dev_ops tun_ops = {
92 { TUN, 0, 0 },
93 .d_open = tunopen,
94 .d_close = tunclose,
95 .d_read = tunread,
96 .d_write = tunwrite,
97 .d_ioctl = tunioctl,
98 .d_kqfilter = tunkqfilter
99 };
100
101 /* kqueue support */
102 static void tun_filter_detach(struct knote *);
103 static int tun_filter_read(struct knote *, long);
104 static int tun_filter_write(struct knote *, long);
105
106 static struct filterops tun_read_filtops = {
107 FILTEROP_ISFD,
108 NULL,
109 tun_filter_detach,
110 tun_filter_read
111 };
112 static struct filterops tun_write_filtops = {
113 FILTEROP_ISFD,
114 NULL,
115 tun_filter_detach,
116 tun_filter_write
117 };
118
119 static int tundebug = 0; /* debug flag */
120 static int tunrefcnt = 0; /* module reference counter */
121
122 static MALLOC_DEFINE(M_TUN, TUN, "Tunnel Interface");
123
124 static DEVFS_DEFINE_CLONE_BITMAP(tun);
125
126 struct if_clone tun_cloner = IF_CLONE_INITIALIZER(
127 TUN, tun_clone_create, tun_clone_destroy, 0, IF_MAXUNIT);
128
129 static SLIST_HEAD(,tun_softc) tun_listhead =
130 SLIST_HEAD_INITIALIZER(&tun_listhead);
131
132 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0,
133 "Enable debug output");
134 SYSCTL_DECL(_net_link);
135 SYSCTL_NODE(_net_link, OID_AUTO, tun, CTLFLAG_RW, 0,
136 "IP tunnel software network interface");
137 SYSCTL_INT(_net_link_tun, OID_AUTO, debug, CTLFLAG_RW, &tundebug, 0,
138 "Enable debug output");
139 SYSCTL_INT(_net_link_tun, OID_AUTO, refcnt, CTLFLAG_RD, &tunrefcnt, 0,
140 "Number of opened devices");
141
142 DEV_MODULE(if_tun, tunmodevent, NULL);
143
144 /*
145 * tunmodevent - module event handler
146 */
147 static int
tunmodevent(module_t mod,int type,void * data)148 tunmodevent(module_t mod, int type, void *data)
149 {
150 static cdev_t dev = NULL;
151 struct tun_softc *sc, *sc_tmp;
152
153 switch (type) {
154 case MOD_LOAD:
155 dev = make_autoclone_dev(&tun_ops, &DEVFS_CLONE_BITMAP(tun),
156 tunclone, UID_UUCP, GID_DIALER,
157 0600, TUN);
158
159 SLIST_INIT(&tun_listhead);
160 if_clone_attach(&tun_cloner);
161 break;
162
163 case MOD_UNLOAD:
164 if (tunrefcnt > 0)
165 return (EBUSY);
166
167 if_clone_detach(&tun_cloner);
168
169 SLIST_FOREACH_MUTABLE(sc, &tun_listhead, tun_link, sc_tmp)
170 tundestroy(sc);
171
172 dev_ops_remove_all(&tun_ops);
173 destroy_autoclone_dev(dev, &DEVFS_CLONE_BITMAP(tun));
174 break;
175
176 default:
177 return (EOPNOTSUPP);
178 }
179
180 return (0);
181 }
182
183 static int
tunclone(struct dev_clone_args * ap)184 tunclone(struct dev_clone_args *ap)
185 {
186 char ifname[IFNAMSIZ];
187 int unit;
188
189 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(tun), 0);
190 ksnprintf(ifname, IFNAMSIZ, "%s%d", TUN, unit);
191 ap->a_dev = make_only_dev(&tun_ops, unit, UID_UUCP, GID_DIALER,
192 0600, "%s", ifname);
193
194 /*
195 * Use the if_clone framework to create cloned device/interface,
196 * so the two clone methods (autoclone device /dev/tun; ifconfig
197 * clone) are consistent and can be mix used.
198 *
199 * Need to pass the cdev_t because the device created by
200 * 'make_only_dev()' doesn't appear in '/dev' yet so that it can't
201 * be found by 'devfs_find_device_by_name()' in 'tun_clone_create()'.
202 */
203 return (if_clone_create(ifname, IFNAMSIZ, NULL, (caddr_t)ap->a_dev));
204 }
205
206 static struct tun_softc *
tuncreate(cdev_t dev,int flags)207 tuncreate(cdev_t dev, int flags)
208 {
209 struct tun_softc *sc;
210 struct ifnet *ifp;
211 int unit = minor(dev);
212
213 sc = kmalloc(sizeof(*sc), M_TUN, M_WAITOK | M_ZERO);
214 dev->si_drv1 = sc;
215 sc->tun_dev = dev;
216 sc->tun_flags = TUN_INITED;
217 sc->tun_flags |= flags;
218
219 reference_dev(dev); /* device association */
220
221 ifp = sc->tun_ifp = if_alloc(IFT_PPP);
222 if (ifp == NULL) {
223 kprintf("%s: failed to if_alloc() interface for %s%d",
224 __func__, TUN, unit);
225 return (NULL);
226 }
227
228 if_initname(ifp, TUN, unit);
229 ifp->if_mtu = TUNMTU;
230 ifp->if_ioctl = tunifioctl;
231 ifp->if_output = tunifoutput;
232 ifp->if_start = tunifstart;
233 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
234 ifp->if_softc = sc;
235 ifq_set_maxlen(&ifp->if_snd, ifqmaxlen);
236 ifq_set_ready(&ifp->if_snd);
237
238 if_attach(ifp, NULL);
239 bpfattach(ifp, DLT_NULL, sizeof(uint32_t));
240
241 SLIST_INSERT_HEAD(&tun_listhead, sc, tun_link);
242 TUNDEBUG(ifp, "created, minor = %#x, flags = 0x%x\n",
243 unit, sc->tun_flags);
244 return (sc);
245 }
246
247 static void
tundestroy(struct tun_softc * sc)248 tundestroy(struct tun_softc *sc)
249 {
250 cdev_t dev = sc->tun_dev;
251 struct ifnet *ifp = sc->tun_ifp;
252 int unit = minor(dev);
253
254 TUNDEBUG(ifp, "destroyed, minor = %#x. Module refcnt = %d\n",
255 unit, tunrefcnt);
256
257 bpfdetach(ifp);
258 if_detach(ifp);
259 if_free(ifp);
260
261 sc->tun_dev = NULL;
262 dev->si_drv1 = NULL;
263 release_dev(dev); /* device disassociation */
264
265 /* Also destroy the cloned device */
266 destroy_dev(dev);
267 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(tun), unit);
268
269 SLIST_REMOVE(&tun_listhead, sc, tun_softc, tun_link);
270 kfree(sc, M_TUN);
271 }
272
273 /*
274 * tunnel open - must be superuser & the device must be configured in
275 */
276 static int
tunopen(struct dev_open_args * ap)277 tunopen(struct dev_open_args *ap)
278 {
279 cdev_t dev = ap->a_head.a_dev;
280 struct tun_softc *sc;
281 int error;
282
283 if ((error = caps_priv_check(ap->a_cred, SYSCAP_RESTRICTEDROOT)) != 0)
284 return (error);
285
286 sc = dev->si_drv1;
287 if (sc == NULL && (sc = tuncreate(dev, 0)) == NULL)
288 return (ENOMEM);
289 if (sc->tun_flags & TUN_OPEN)
290 return (EBUSY);
291
292 sc->tun_pid = curproc->p_pid;
293 sc->tun_flags |= TUN_OPEN;
294 tunrefcnt++;
295
296 TUNDEBUG(sc->tun_ifp, "opened, minor = %#x. Module refcnt = %d\n",
297 minor(dev), tunrefcnt);
298 return (0);
299 }
300
301 /*
302 * close the device - mark interface down & delete routing info
303 */
304 static int
tunclose(struct dev_close_args * ap)305 tunclose(struct dev_close_args *ap)
306 {
307 cdev_t dev = ap->a_head.a_dev;
308 struct tun_softc *sc = dev->si_drv1;
309 struct ifnet *ifp;
310 int unit = minor(dev);
311 char ifname[IFNAMSIZ];
312
313 KASSERT(sc != NULL,
314 ("try closing the already destroyed %s%d", TUN, unit));
315 ifp = sc->tun_ifp;
316
317 sc->tun_flags &= ~TUN_OPEN;
318 sc->tun_pid = 0;
319
320 /* Junk all pending output. */
321 ifq_purge_all(&ifp->if_snd);
322
323 if (ifp->if_flags & IFF_UP)
324 if_down(ifp);
325 ifp->if_flags &= ~IFF_RUNNING;
326
327 if ((sc->tun_flags & TUN_MANUALMAKE) == 0) {
328 if_purgeaddrs_nolink(ifp);
329
330 EVENTHANDLER_INVOKE(ifnet_detach_event, ifp);
331
332 /* Announce the departure of the interface. */
333 rt_ifannouncemsg(ifp, IFAN_DEPARTURE);
334 }
335
336 funsetown(&sc->tun_sigio);
337 KNOTE(&sc->tun_rkq.ki_note, 0);
338
339 tunrefcnt--;
340 if (tunrefcnt < 0) {
341 tunrefcnt = 0;
342 if_printf(ifp, ". Module refcnt = %d is out of sync! "
343 "Force refcnt to be 0.\n", tunrefcnt);
344 }
345
346 TUNDEBUG(ifp, "closed, minor = %#x. Module refcnt = %d\n",
347 unit, tunrefcnt);
348
349 /* Only auto-destroy if the interface was not manually created. */
350 if ((sc->tun_flags & TUN_MANUALMAKE) == 0) {
351 ksnprintf(ifname, IFNAMSIZ, "%s%d", TUN, unit);
352 if_clone_destroy(ifname);
353 }
354
355 return (0);
356 }
357
358
359 /*
360 * Interface clone support
361 *
362 * Create and destroy tun device/interface via ifconfig(8).
363 */
364
365 static struct tun_softc *
tunfind(int unit)366 tunfind(int unit)
367 {
368 struct tun_softc *sc;
369
370 SLIST_FOREACH(sc, &tun_listhead, tun_link) {
371 if (minor(sc->tun_dev) == unit)
372 return (sc);
373 }
374 return (NULL);
375 }
376
377 static int
tun_clone_create(struct if_clone * ifc __unused,int unit,caddr_t params __unused,caddr_t data)378 tun_clone_create(struct if_clone *ifc __unused, int unit,
379 caddr_t params __unused, caddr_t data)
380 {
381 struct tun_softc *sc;
382 cdev_t dev = (cdev_t)data;
383 int flags;
384
385 if (tunfind(unit) != NULL)
386 return (EEXIST);
387
388 if (dev == NULL) {
389 if (!devfs_clone_bitmap_chk(&DEVFS_CLONE_BITMAP(tun), unit)) {
390 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(tun), unit);
391 dev = make_dev(&tun_ops, unit, UID_UUCP, GID_DIALER,
392 0600, "%s%d", TUN, unit);
393 } else {
394 dev = devfs_find_device_by_name("%s%d", TUN, unit);
395 if (dev == NULL)
396 return (ENOENT);
397 }
398 flags = TUN_MANUALMAKE;
399 } else {
400 flags = 0;
401 }
402
403 if ((sc = tuncreate(dev, flags)) == NULL)
404 return (ENOMEM);
405
406 sc->tun_flags |= TUN_CLONE;
407
408 TUNDEBUG(sc->tun_ifp, "clone created, minor = %#x, flags = 0x%x\n",
409 minor(sc->tun_dev), sc->tun_flags);
410
411 return (0);
412 }
413
414 static int
tun_clone_destroy(struct ifnet * ifp)415 tun_clone_destroy(struct ifnet *ifp)
416 {
417 struct tun_softc *sc = ifp->if_softc;
418
419 if (sc->tun_flags & TUN_OPEN)
420 return (EBUSY);
421 if ((sc->tun_flags & TUN_CLONE) == 0)
422 return (EINVAL);
423
424 TUNDEBUG(ifp, "clone destroyed, minor = %#x, flags = 0x%x\n",
425 minor(sc->tun_dev), sc->tun_flags);
426 tundestroy(sc);
427
428 return (0);
429 }
430
431
432 /*
433 * Network interface functions
434 */
435
436 static int
tunifinit(struct ifnet * ifp)437 tunifinit(struct ifnet *ifp)
438 {
439 #ifdef INET
440 struct tun_softc *sc = ifp->if_softc;
441 #endif
442 struct ifaddr_container *ifac;
443 int error = 0;
444
445 TUNDEBUG(ifp, "initialize\n");
446
447 ifp->if_flags |= IFF_UP | IFF_RUNNING;
448 getmicrotime(&ifp->if_lastchange);
449
450 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
451 struct ifaddr *ifa = ifac->ifa;
452
453 if (ifa->ifa_addr == NULL) {
454 error = EFAULT;
455 /* XXX: Should maybe return straight off? */
456 } else {
457 #ifdef INET
458 if (ifa->ifa_addr->sa_family == AF_INET) {
459 struct sockaddr_in *si;
460
461 si = (struct sockaddr_in *)ifa->ifa_addr;
462 if (si->sin_addr.s_addr)
463 sc->tun_flags |= TUN_IASET;
464 }
465 #endif
466 }
467 }
468 return (error);
469 }
470
471 /*
472 * Process an ioctl request.
473 *
474 * MPSAFE
475 */
476 static int
tunifioctl(struct ifnet * ifp,u_long cmd,caddr_t data,struct ucred * cr)477 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
478 {
479 struct ifreq *ifr = (struct ifreq *)data;
480 struct tun_softc *sc = ifp->if_softc;
481 struct ifstat *ifs;
482 int error = 0;
483
484 switch (cmd) {
485 case SIOCGIFSTATUS:
486 ifs = (struct ifstat *)data;
487 if (sc->tun_pid)
488 ksprintf(ifs->ascii + strlen(ifs->ascii),
489 "\tOpened by PID %d\n", sc->tun_pid);
490 break;
491 case SIOCSIFADDR:
492 error = tunifinit(ifp);
493 TUNDEBUG(ifp, "address set, error=%d\n", error);
494 break;
495 case SIOCSIFDSTADDR:
496 error = tunifinit(ifp);
497 TUNDEBUG(ifp, "destination address set, error=%d\n", error);
498 break;
499 case SIOCSIFMTU:
500 ifp->if_mtu = ifr->ifr_mtu;
501 TUNDEBUG(ifp, "mtu set\n");
502 break;
503 case SIOCSIFFLAGS:
504 case SIOCADDMULTI:
505 case SIOCDELMULTI:
506 break;
507 default:
508 error = EINVAL;
509 }
510 return (error);
511 }
512
513 /*
514 * Start packet transmission on the interface.
515 * when the interface queue is rate-limited by ALTQ,
516 * if_start is needed to drain packets from the queue in order
517 * to notify readers when outgoing packets become ready.
518 */
519 static void
tunifstart(struct ifnet * ifp,struct ifaltq_subque * ifsq)520 tunifstart(struct ifnet *ifp, struct ifaltq_subque *ifsq)
521 {
522 struct tun_softc *sc = ifp->if_softc;
523 struct mbuf *m;
524
525 ASSERT_ALTQ_SQ_DEFAULT(ifp, ifsq);
526
527 if (!ifq_is_enabled(&ifp->if_snd))
528 return;
529
530 m = ifsq_poll(ifsq);
531 if (m != NULL) {
532 if (sc->tun_flags & TUN_RWAIT) {
533 sc->tun_flags &= ~TUN_RWAIT;
534 wakeup((caddr_t)sc);
535 }
536 if (sc->tun_flags & TUN_ASYNC && sc->tun_sigio)
537 pgsigio(sc->tun_sigio, SIGIO, 0);
538 ifsq_deserialize_hw(ifsq);
539 KNOTE(&sc->tun_rkq.ki_note, 0);
540 ifsq_serialize_hw(ifsq);
541 }
542 }
543
544 /*
545 * tunifoutput - queue packets from higher level ready to put out.
546 *
547 * MPSAFE
548 */
549 static int
tunifoutput_serialized(struct ifnet * ifp,struct mbuf * m0,struct sockaddr * dst,struct rtentry * rt)550 tunifoutput_serialized(struct ifnet *ifp, struct mbuf *m0,
551 struct sockaddr *dst, struct rtentry *rt)
552 {
553 struct tun_softc *sc = ifp->if_softc;
554 int error;
555 struct altq_pktattr pktattr;
556
557 TUNDEBUG(ifp, "output\n");
558
559 if ((sc->tun_flags & TUN_READY) != TUN_READY) {
560 TUNDEBUG(ifp, "not ready, flags = 0x%x\n", sc->tun_flags);
561 m_freem(m0);
562 return (EHOSTDOWN);
563 }
564
565 /*
566 * if the queueing discipline needs packet classification,
567 * do it before prepending link headers.
568 */
569 ifq_classify(&ifp->if_snd, m0, dst->sa_family, &pktattr);
570
571 /* BPF write needs to be handled specially */
572 if (dst->sa_family == AF_UNSPEC) {
573 dst->sa_family = *(mtod(m0, int *));
574 m0->m_len -= sizeof(int);
575 m0->m_pkthdr.len -= sizeof(int);
576 m0->m_data += sizeof(int);
577 }
578
579 if (ifp->if_bpf) {
580 bpf_gettoken();
581 if (ifp->if_bpf) {
582 /*
583 * We need to prepend the address family as
584 * a four byte field.
585 */
586 uint32_t af = dst->sa_family;
587
588 bpf_ptap(ifp->if_bpf, m0, &af, sizeof(af));
589 }
590 bpf_reltoken();
591 }
592
593 /* prepend sockaddr? this may abort if the mbuf allocation fails */
594 if (sc->tun_flags & TUN_LMODE) {
595 /* allocate space for sockaddr */
596 M_PREPEND(m0, dst->sa_len, M_NOWAIT);
597
598 /* if allocation failed drop packet */
599 if (m0 == NULL){
600 IFNET_STAT_INC(ifp, oerrors, 1);
601 return (ENOBUFS);
602 } else {
603 bcopy(dst, m0->m_data, dst->sa_len);
604 }
605 }
606
607 if (sc->tun_flags & TUN_IFHEAD) {
608 /* Prepend the address family */
609 M_PREPEND(m0, 4, M_NOWAIT);
610
611 /* if allocation failed drop packet */
612 if (m0 == NULL){
613 IFNET_STAT_INC(ifp, oerrors, 1);
614 return (ENOBUFS);
615 } else {
616 *(u_int32_t *)m0->m_data = htonl(dst->sa_family);
617 }
618 } else {
619 #ifdef INET
620 if (dst->sa_family != AF_INET)
621 #endif
622 {
623 m_freem(m0);
624 return (EAFNOSUPPORT);
625 }
626 }
627
628 error = ifq_handoff(ifp, m0, &pktattr);
629 if (error) {
630 IFNET_STAT_INC(ifp, collisions, 1);
631 } else {
632 IFNET_STAT_INC(ifp, opackets, 1);
633 if (sc->tun_flags & TUN_RWAIT) {
634 sc->tun_flags &= ~TUN_RWAIT;
635 wakeup((caddr_t)sc);
636 }
637 get_mplock();
638 if (sc->tun_flags & TUN_ASYNC && sc->tun_sigio)
639 pgsigio(sc->tun_sigio, SIGIO, 0);
640 rel_mplock();
641 ifnet_deserialize_all(ifp);
642 KNOTE(&sc->tun_rkq.ki_note, 0);
643 ifnet_serialize_all(ifp);
644 }
645 return (error);
646 }
647
648 static int
tunifoutput(struct ifnet * ifp,struct mbuf * m0,struct sockaddr * dst,struct rtentry * rt)649 tunifoutput(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst,
650 struct rtentry *rt)
651 {
652 int error;
653
654 ifnet_serialize_all(ifp);
655 error = tunifoutput_serialized(ifp, m0, dst, rt);
656 ifnet_deserialize_all(ifp);
657
658 return (error);
659 }
660
661
662 /*
663 * the ops interface is now pretty minimal.
664 */
665 static int
tunioctl(struct dev_ioctl_args * ap)666 tunioctl(struct dev_ioctl_args *ap)
667 {
668 cdev_t dev = ap->a_head.a_dev;
669 caddr_t data = ap->a_data;
670 struct tun_softc *sc = dev->si_drv1;
671 struct ifnet *ifp = sc->tun_ifp;
672 struct ifreq *ifr;
673 struct tuninfo *tunp;
674 int error = 0;
675
676 switch (ap->a_cmd) {
677 case TUNSIFINFO:
678 tunp = (struct tuninfo *)data;
679 if (ifp->if_type != tunp->type)
680 return (EPROTOTYPE);
681 if (tunp->mtu < IF_MINMTU)
682 return (EINVAL);
683 ifp->if_mtu = tunp->mtu;
684 ifp->if_baudrate = tunp->baudrate;
685 break;
686
687 case TUNGIFINFO:
688 tunp = (struct tuninfo *)data;
689 tunp->mtu = ifp->if_mtu;
690 tunp->type = ifp->if_type;
691 tunp->baudrate = ifp->if_baudrate;
692 break;
693
694 case TUNGIFNAME:
695 ifr = (struct ifreq *)data;
696 strlcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ);
697 break;
698
699 case TUNSDEBUG:
700 tundebug = *(int *)data;
701 break;
702
703 case TUNGDEBUG:
704 *(int *)data = tundebug;
705 break;
706
707 case TUNSLMODE:
708 if (*(int *)data) {
709 sc->tun_flags |= TUN_LMODE;
710 sc->tun_flags &= ~TUN_IFHEAD;
711 } else {
712 sc->tun_flags &= ~TUN_LMODE;
713 }
714 break;
715
716 case TUNSIFHEAD:
717 if (*(int *)data) {
718 sc->tun_flags |= TUN_IFHEAD;
719 sc->tun_flags &= ~TUN_LMODE;
720 } else {
721 sc->tun_flags &= ~TUN_IFHEAD;
722 }
723 break;
724
725 case TUNGIFHEAD:
726 *(int *)data = (sc->tun_flags & TUN_IFHEAD) ? 1 : 0;
727 break;
728
729 case TUNSIFMODE:
730 /* deny this if UP */
731 if (ifp->if_flags & IFF_UP)
732 return (EBUSY);
733
734 switch (*(int *)data & ~IFF_MULTICAST) {
735 case IFF_POINTOPOINT:
736 case IFF_BROADCAST:
737 ifp->if_flags &= ~(IFF_BROADCAST | IFF_POINTOPOINT);
738 ifp->if_flags |= *(int *)data;
739 break;
740 default:
741 return (EINVAL);
742 }
743 break;
744
745 case TUNSIFPID:
746 sc->tun_pid = curproc->p_pid;
747 break;
748
749 case FIOASYNC:
750 if (*(int *)data)
751 sc->tun_flags |= TUN_ASYNC;
752 else
753 sc->tun_flags &= ~TUN_ASYNC;
754 break;
755
756 case FIONREAD:
757 *(int *)data = ifsq_poll_pktlen(
758 ifq_get_subq_default(&ifp->if_snd));
759 break;
760
761 case FIOSETOWN:
762 error = fsetown(*(int *)data, &sc->tun_sigio);
763 break;
764
765 case FIOGETOWN:
766 *(int *)data = fgetown(&sc->tun_sigio);
767 break;
768
769 /* This is deprecated, FIOSETOWN should be used instead. */
770 case TIOCSPGRP:
771 error = fsetown(-(*(int *)data), &sc->tun_sigio);
772 break;
773
774 /* This is deprecated, FIOGETOWN should be used instead. */
775 case TIOCGPGRP:
776 *(int *)data = -fgetown(&sc->tun_sigio);
777 break;
778
779 default:
780 error = ENOTTY;
781 break;
782 }
783
784 return (error);
785 }
786
787 /*
788 * The ops read interface - reads a packet at a time, or at
789 * least as much of a packet as can be read.
790 */
791 static int
tunread(struct dev_read_args * ap)792 tunread(struct dev_read_args *ap)
793 {
794 cdev_t dev = ap->a_head.a_dev;
795 struct uio *uio = ap->a_uio;
796 struct tun_softc *sc = dev->si_drv1;
797 struct ifnet *ifp = sc->tun_ifp;
798 struct ifaltq_subque *ifsq = ifq_get_subq_default(&ifp->if_snd);
799 struct mbuf *m0;
800 int error=0, len;
801
802 TUNDEBUG(ifp, "read\n");
803 if ((sc->tun_flags & TUN_READY) != TUN_READY) {
804 TUNDEBUG(ifp, "not ready, flags = 0x%x\n", sc->tun_flags);
805 return (EHOSTDOWN);
806 }
807
808 sc->tun_flags &= ~TUN_RWAIT;
809
810 ifnet_serialize_all(ifp);
811
812 while ((m0 = ifsq_dequeue(ifsq)) == NULL) {
813 if (ap->a_ioflag & IO_NDELAY) {
814 ifnet_deserialize_all(ifp);
815 return (EWOULDBLOCK);
816 }
817 sc->tun_flags |= TUN_RWAIT;
818 ifnet_deserialize_all(ifp);
819 if ((error = tsleep(sc, PCATCH, "tunread", 0)) != 0)
820 return (error);
821 ifnet_serialize_all(ifp);
822 }
823
824 ifnet_deserialize_all(ifp);
825
826 while (m0 && uio->uio_resid > 0 && error == 0) {
827 len = (int)szmin(uio->uio_resid, m0->m_len);
828 if (len != 0)
829 error = uiomove(mtod(m0, caddr_t), (size_t)len, uio);
830 m0 = m_free(m0);
831 }
832
833 if (m0) {
834 TUNDEBUG(ifp, "dropping mbuf\n");
835 m_freem(m0);
836 }
837 return (error);
838 }
839
840 /*
841 * the ops write interface - an atomic write is a packet - or else!
842 */
843 static int
tunwrite(struct dev_write_args * ap)844 tunwrite(struct dev_write_args *ap)
845 {
846 cdev_t dev = ap->a_head.a_dev;
847 struct uio *uio = ap->a_uio;
848 struct tun_softc *sc = dev->si_drv1;
849 struct ifnet *ifp = sc->tun_ifp;
850 struct mbuf *top, **mp, *m;
851 size_t tlen;
852 uint32_t family, mru;
853 int error = 0;
854 int isr;
855
856 TUNDEBUG(ifp, "tunwrite\n");
857
858 if (uio->uio_resid == 0)
859 return (0);
860
861 mru = TUNMRU;
862 if (sc->tun_flags & TUN_IFHEAD)
863 mru += sizeof(family);
864 if (uio->uio_resid > mru) {
865 TUNDEBUG(ifp, "len = %zd!\n", uio->uio_resid);
866 return (EIO);
867 }
868
869 /* get a header mbuf */
870 MGETHDR(m, M_WAITOK, MT_DATA);
871
872 tlen = uio->uio_resid;
873 top = NULL;
874 mp = ⊤
875 while (error == 0 && uio->uio_resid > 0) {
876 m->m_len = (int)szmin(MHLEN, uio->uio_resid);
877 error = uiomove(mtod(m, caddr_t), (size_t)m->m_len, uio);
878 *mp = m;
879 mp = &m->m_next;
880 if (uio->uio_resid > 0)
881 MGET(m, M_WAITOK, MT_DATA);
882 }
883 if (error) {
884 if (top)
885 m_freem(top);
886 IFNET_STAT_INC(ifp, ierrors, 1);
887 return (error);
888 }
889
890 top->m_pkthdr.len = (int)tlen;
891 top->m_pkthdr.rcvif = ifp;
892
893 if (ifp->if_bpf) {
894 bpf_gettoken();
895
896 if (ifp->if_bpf) {
897 if (sc->tun_flags & TUN_IFHEAD) {
898 /*
899 * Conveniently, we already have a 4-byte
900 * address family prepended to our packet !
901 * Inconveniently, it's in the wrong byte
902 * order !
903 */
904 if ((top = m_pullup(top, sizeof(family)))
905 == NULL) {
906 bpf_reltoken();
907 return (ENOBUFS);
908 }
909 *mtod(top, u_int32_t *) =
910 ntohl(*mtod(top, u_int32_t *));
911 bpf_mtap(ifp->if_bpf, top);
912 *mtod(top, u_int32_t *) =
913 htonl(*mtod(top, u_int32_t *));
914 } else {
915 /*
916 * We need to prepend the address family as
917 * a four byte field.
918 */
919 static const uint32_t af = AF_INET;
920
921 bpf_ptap(ifp->if_bpf, top, &af, sizeof(af));
922 }
923 }
924
925 bpf_reltoken();
926 }
927
928 if (sc->tun_flags & TUN_IFHEAD) {
929 if (top->m_len < sizeof(family) &&
930 (top = m_pullup(top, sizeof(family))) == NULL)
931 return (ENOBUFS);
932 family = ntohl(*mtod(top, u_int32_t *));
933 m_adj(top, sizeof(family));
934 } else {
935 family = AF_INET;
936 }
937
938 IFNET_STAT_INC(ifp, ibytes, top->m_pkthdr.len);
939 IFNET_STAT_INC(ifp, ipackets, 1);
940
941 switch (family) {
942 #ifdef INET
943 case AF_INET:
944 isr = NETISR_IP;
945 break;
946 #endif
947 #ifdef INET6
948 case AF_INET6:
949 isr = NETISR_IPV6;
950 break;
951 #endif
952 default:
953 m_freem(m);
954 return (EAFNOSUPPORT);
955 }
956
957 netisr_queue(isr, top);
958 return (0);
959 }
960
961
962 /*
963 * tunkqfilter - support for the kevent() system call.
964 */
965 static int
tunkqfilter(struct dev_kqfilter_args * ap)966 tunkqfilter(struct dev_kqfilter_args *ap)
967 {
968 cdev_t dev = ap->a_head.a_dev;
969 struct tun_softc *sc = dev->si_drv1;
970 struct ifnet *ifp = sc->tun_ifp;
971 struct knote *kn = ap->a_kn;
972 struct klist *klist;
973
974 ap->a_result = 0;
975 ifnet_serialize_all(ifp);
976
977 switch (kn->kn_filter) {
978 case EVFILT_READ:
979 kn->kn_fop = &tun_read_filtops;
980 kn->kn_hook = (caddr_t)sc;
981 break;
982 case EVFILT_WRITE:
983 kn->kn_fop = &tun_write_filtops;
984 kn->kn_hook = (caddr_t)sc;
985 break;
986 default:
987 ifnet_deserialize_all(ifp);
988 ap->a_result = EOPNOTSUPP;
989 return (0);
990 }
991
992 klist = &sc->tun_rkq.ki_note;
993 knote_insert(klist, kn);
994 ifnet_deserialize_all(ifp);
995
996 return (0);
997 }
998
999 static void
tun_filter_detach(struct knote * kn)1000 tun_filter_detach(struct knote *kn)
1001 {
1002 struct tun_softc *sc = (struct tun_softc *)kn->kn_hook;
1003 struct klist *klist = &sc->tun_rkq.ki_note;
1004
1005 knote_remove(klist, kn);
1006 }
1007
1008 static int
tun_filter_write(struct knote * kn,long hint)1009 tun_filter_write(struct knote *kn, long hint)
1010 {
1011 /* Always ready for a write */
1012 return (1);
1013 }
1014
1015 static int
tun_filter_read(struct knote * kn,long hint)1016 tun_filter_read(struct knote *kn, long hint)
1017 {
1018 struct tun_softc *sc = (struct tun_softc *)kn->kn_hook;
1019 struct ifnet *ifp = sc->tun_ifp;
1020 int ready = 0;
1021
1022 ifnet_serialize_all(ifp);
1023 if (!ifsq_is_empty(ifq_get_subq_default(&ifp->if_snd))) {
1024 if ((kn->kn_sfflags & NOTE_HUPONLY) == 0)
1025 ready = 1;
1026 }
1027 ifnet_deserialize_all(ifp);
1028
1029 return (ready);
1030 }
1031