FreeBSD/Linux Kernel Cross Reference
sys/net/if_tun.c
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: releng/7.3/sys/net/if_tun.c 202814 2010-01-22 17:02:07Z jhb $
17 */
18
19 #include "opt_atalk.h"
20 #include "opt_inet.h"
21 #include "opt_inet6.h"
22 #include "opt_ipx.h"
23 #include "opt_mac.h"
24
25 #include <sys/param.h>
26 #include <sys/priv.h>
27 #include <sys/proc.h>
28 #include <sys/systm.h>
29 #include <sys/mbuf.h>
30 #include <sys/module.h>
31 #include <sys/socket.h>
32 #include <sys/fcntl.h>
33 #include <sys/filio.h>
34 #include <sys/sockio.h>
35 #include <sys/ttycom.h>
36 #include <sys/poll.h>
37 #include <sys/selinfo.h>
38 #include <sys/signalvar.h>
39 #include <sys/filedesc.h>
40 #include <sys/kernel.h>
41 #include <sys/sysctl.h>
42 #include <sys/conf.h>
43 #include <sys/uio.h>
44 #include <sys/malloc.h>
45 #include <sys/random.h>
46
47 #include <net/if.h>
48 #include <net/if_clone.h>
49 #include <net/if_types.h>
50 #include <net/netisr.h>
51 #include <net/route.h>
52 #ifdef INET
53 #include <netinet/in.h>
54 #endif
55 #include <net/bpf.h>
56 #include <net/if_tun.h>
57
58 #include <sys/queue.h>
59
60 #include <security/mac/mac_framework.h>
61
62 /*
63 * tun_list is protected by global tunmtx. Other mutable fields are
64 * protected by tun->tun_mtx, or by their owning subsystem. tun_dev is
65 * static for the duration of a tunnel interface.
66 */
67 struct tun_softc {
68 TAILQ_ENTRY(tun_softc) tun_list;
69 struct cdev *tun_dev;
70 u_short tun_flags; /* misc flags */
71 #define TUN_OPEN 0x0001
72 #define TUN_INITED 0x0002
73 #define TUN_RCOLL 0x0004
74 #define TUN_IASET 0x0008
75 #define TUN_DSTADDR 0x0010
76 #define TUN_LMODE 0x0020
77 #define TUN_RWAIT 0x0040
78 #define TUN_ASYNC 0x0080
79 #define TUN_IFHEAD 0x0100
80
81 #define TUN_READY (TUN_OPEN | TUN_INITED)
82
83 /*
84 * XXXRW: tun_pid is used to exclusively lock /dev/tun. Is this
85 * actually needed? Can we just return EBUSY if already open?
86 * Problem is that this involved inherent races when a tun device
87 * is handed off from one process to another, as opposed to just
88 * being slightly stale informationally.
89 */
90 pid_t tun_pid; /* owning pid */
91 struct ifnet *tun_ifp; /* the interface */
92 struct sigio *tun_sigio; /* information for async I/O */
93 struct selinfo tun_rsel; /* read select */
94 struct mtx tun_mtx; /* protect mutable softc fields */
95 };
96 #define TUN2IFP(sc) ((sc)->tun_ifp)
97
98 #define TUNDEBUG if (tundebug) if_printf
99 #define TUNNAME "tun"
100
101 /*
102 * All mutable global variables in if_tun are locked using tunmtx, with
103 * the exception of tundebug, which is used unlocked, and tunclones,
104 * which is static after setup.
105 */
106 static struct mtx tunmtx;
107 static MALLOC_DEFINE(M_TUN, TUNNAME, "Tunnel Interface");
108 static int tundebug = 0;
109 static int tundclone = 1;
110 static struct clonedevs *tunclones;
111 static TAILQ_HEAD(,tun_softc) tunhead = TAILQ_HEAD_INITIALIZER(tunhead);
112 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");
113
114 SYSCTL_DECL(_net_link);
115 SYSCTL_NODE(_net_link, OID_AUTO, tun, CTLFLAG_RW, 0,
116 "IP tunnel software network interface.");
117 SYSCTL_INT(_net_link_tun, OID_AUTO, devfs_cloning, CTLFLAG_RW, &tundclone, 0,
118 "Enable legacy devfs interface creation.");
119
120 TUNABLE_INT("net.link.tun.devfs_cloning", &tundclone);
121
122 static void tunclone(void *arg, struct ucred *cred, char *name,
123 int namelen, struct cdev **dev);
124 static void tuncreate(const char *name, struct cdev *dev);
125 static int tunifioctl(struct ifnet *, u_long, caddr_t);
126 static int tuninit(struct ifnet *);
127 static int tunmodevent(module_t, int, void *);
128 static int tunoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
129 struct rtentry *rt);
130 static void tunstart(struct ifnet *);
131
132 static int tun_clone_create(struct if_clone *, int, caddr_t);
133 static void tun_clone_destroy(struct ifnet *);
134
135 IFC_SIMPLE_DECLARE(tun, 0);
136
137 static d_open_t tunopen;
138 static d_close_t tunclose;
139 static d_read_t tunread;
140 static d_write_t tunwrite;
141 static d_ioctl_t tunioctl;
142 static d_poll_t tunpoll;
143 static d_kqfilter_t tunkqfilter;
144
145 static int tunkqread(struct knote *, long);
146 static int tunkqwrite(struct knote *, long);
147 static void tunkqdetach(struct knote *);
148
149 static struct filterops tun_read_filterops = {
150 .f_isfd = 1,
151 .f_attach = NULL,
152 .f_detach = tunkqdetach,
153 .f_event = tunkqread,
154 };
155
156 static struct filterops tun_write_filterops = {
157 .f_isfd = 1,
158 .f_attach = NULL,
159 .f_detach = tunkqdetach,
160 .f_event = tunkqwrite,
161 };
162
163 static struct cdevsw tun_cdevsw = {
164 .d_version = D_VERSION,
165 .d_flags = D_PSEUDO | D_NEEDGIANT,
166 .d_open = tunopen,
167 .d_close = tunclose,
168 .d_read = tunread,
169 .d_write = tunwrite,
170 .d_ioctl = tunioctl,
171 .d_poll = tunpoll,
172 .d_kqfilter = tunkqfilter,
173 .d_name = TUNNAME,
174 };
175
176 static int
177 tun_clone_create(struct if_clone *ifc, int unit, caddr_t params)
178 {
179 struct cdev *dev;
180 int i;
181
182 /* find any existing device, or allocate new unit number */
183 i = clone_create(&tunclones, &tun_cdevsw, &unit, &dev, 0);
184 if (i) {
185 /* No preexisting struct cdev *, create one */
186 dev = make_dev(&tun_cdevsw, unit2minor(unit),
187 UID_UUCP, GID_DIALER, 0600, "%s%d", ifc->ifc_name, unit);
188 if (dev != NULL) {
189 dev_ref(dev);
190 dev->si_flags |= SI_CHEAPCLONE;
191 }
192 }
193 tuncreate(ifc->ifc_name, dev);
194
195 return (0);
196 }
197
198 static void
199 tunclone(void *arg, struct ucred *cred, char *name, int namelen,
200 struct cdev **dev)
201 {
202 char devname[SPECNAMELEN + 1];
203 int u, i, append_unit;
204
205 if (*dev != NULL)
206 return;
207
208 /*
209 * If tun cloning is enabled, only the superuser can create an
210 * interface.
211 */
212 if (!tundclone || priv_check_cred(cred, PRIV_NET_IFCREATE, 0) != 0)
213 return;
214
215 if (strcmp(name, TUNNAME) == 0) {
216 u = -1;
217 } else if (dev_stdclone(name, NULL, TUNNAME, &u) != 1)
218 return; /* Don't recognise the name */
219 if (u != -1 && u > IF_MAXUNIT)
220 return; /* Unit number too high */
221
222 if (u == -1)
223 append_unit = 1;
224 else
225 append_unit = 0;
226
227 /* find any existing device, or allocate new unit number */
228 i = clone_create(&tunclones, &tun_cdevsw, &u, dev, 0);
229 if (i) {
230 if (append_unit) {
231 namelen = snprintf(devname, sizeof(devname), "%s%d", name,
232 u);
233 name = devname;
234 }
235 /* No preexisting struct cdev *, create one */
236 *dev = make_dev(&tun_cdevsw, unit2minor(u),
237 UID_UUCP, GID_DIALER, 0600, "%s", name);
238 if (*dev != NULL) {
239 dev_ref(*dev);
240 (*dev)->si_flags |= SI_CHEAPCLONE;
241 }
242 }
243
244 if_clone_create(name, namelen, NULL);
245 }
246
247 static void
248 tun_destroy(struct tun_softc *tp)
249 {
250 struct cdev *dev;
251
252 /* Unlocked read. */
253 KASSERT((tp->tun_flags & TUN_OPEN) == 0,
254 ("tununits is out of sync - unit %d", TUN2IFP(tp)->if_dunit));
255
256 dev = tp->tun_dev;
257 bpfdetach(TUN2IFP(tp));
258 if_detach(TUN2IFP(tp));
259 if_free(TUN2IFP(tp));
260 destroy_dev(dev);
261 knlist_destroy(&tp->tun_rsel.si_note);
262 mtx_destroy(&tp->tun_mtx);
263 free(tp, M_TUN);
264 }
265
266 static void
267 tun_clone_destroy(struct ifnet *ifp)
268 {
269 struct tun_softc *tp = ifp->if_softc;
270
271 mtx_lock(&tunmtx);
272 TAILQ_REMOVE(&tunhead, tp, tun_list);
273 mtx_unlock(&tunmtx);
274 tun_destroy(tp);
275 }
276
277 static int
278 tunmodevent(module_t mod, int type, void *data)
279 {
280 static eventhandler_tag tag;
281 struct tun_softc *tp;
282
283 switch (type) {
284 case MOD_LOAD:
285 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF);
286 clone_setup(&tunclones);
287 tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000);
288 if (tag == NULL)
289 return (ENOMEM);
290 if_clone_attach(&tun_cloner);
291 break;
292 case MOD_UNLOAD:
293 if_clone_detach(&tun_cloner);
294 EVENTHANDLER_DEREGISTER(dev_clone, tag);
295
296 mtx_lock(&tunmtx);
297 while ((tp = TAILQ_FIRST(&tunhead)) != NULL) {
298 TAILQ_REMOVE(&tunhead, tp, tun_list);
299 mtx_unlock(&tunmtx);
300 tun_destroy(tp);
301 mtx_lock(&tunmtx);
302 }
303 mtx_unlock(&tunmtx);
304 clone_cleanup(&tunclones);
305 mtx_destroy(&tunmtx);
306 break;
307 default:
308 return EOPNOTSUPP;
309 }
310 return 0;
311 }
312
313 static moduledata_t tun_mod = {
314 "if_tun",
315 tunmodevent,
316 0
317 };
318
319 DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
320
321 static void
322 tunstart(struct ifnet *ifp)
323 {
324 struct tun_softc *tp = ifp->if_softc;
325 struct mbuf *m;
326
327 TUNDEBUG(ifp,"%s starting\n", ifp->if_xname);
328 if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
329 IFQ_LOCK(&ifp->if_snd);
330 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
331 if (m == NULL) {
332 IFQ_UNLOCK(&ifp->if_snd);
333 return;
334 }
335 IFQ_UNLOCK(&ifp->if_snd);
336 }
337
338 mtx_lock(&tp->tun_mtx);
339 if (tp->tun_flags & TUN_RWAIT) {
340 tp->tun_flags &= ~TUN_RWAIT;
341 wakeup(tp);
342 }
343 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) {
344 mtx_unlock(&tp->tun_mtx);
345 pgsigio(&tp->tun_sigio, SIGIO, 0);
346 } else
347 mtx_unlock(&tp->tun_mtx);
348 selwakeuppri(&tp->tun_rsel, PZERO + 1);
349 KNOTE_UNLOCKED(&tp->tun_rsel.si_note, 0);
350 }
351
352 /* XXX: should return an error code so it can fail. */
353 static void
354 tuncreate(const char *name, struct cdev *dev)
355 {
356 struct tun_softc *sc;
357 struct ifnet *ifp;
358
359 dev->si_flags &= ~SI_CHEAPCLONE;
360
361 MALLOC(sc, struct tun_softc *, sizeof(*sc), M_TUN, M_WAITOK | M_ZERO);
362 mtx_init(&sc->tun_mtx, "tun_mtx", NULL, MTX_DEF);
363 sc->tun_flags = TUN_INITED;
364 sc->tun_dev = dev;
365 mtx_lock(&tunmtx);
366 TAILQ_INSERT_TAIL(&tunhead, sc, tun_list);
367 mtx_unlock(&tunmtx);
368
369 ifp = sc->tun_ifp = if_alloc(IFT_PPP);
370 if (ifp == NULL)
371 panic("%s%d: failed to if_alloc() interface.\n",
372 name, dev2unit(dev));
373 if_initname(ifp, name, dev2unit(dev));
374 ifp->if_mtu = TUNMTU;
375 ifp->if_ioctl = tunifioctl;
376 ifp->if_output = tunoutput;
377 ifp->if_start = tunstart;
378 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
379 ifp->if_softc = sc;
380 IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
381 ifp->if_snd.ifq_drv_maxlen = 0;
382 IFQ_SET_READY(&ifp->if_snd);
383 knlist_init_mtx(&sc->tun_rsel.si_note, NULL);
384
385 if_attach(ifp);
386 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
387 dev->si_drv1 = sc;
388 TUNDEBUG(ifp, "interface %s is created, minor = %#x\n",
389 ifp->if_xname, minor(dev));
390 }
391
392 static int
393 tunopen(struct cdev *dev, int flag, int mode, struct thread *td)
394 {
395 struct ifnet *ifp;
396 struct tun_softc *tp;
397
398 /*
399 * XXXRW: Non-atomic test and set of dev->si_drv1 requires
400 * synchronization.
401 */
402 tp = dev->si_drv1;
403 if (!tp) {
404 tuncreate(TUNNAME, dev);
405 tp = dev->si_drv1;
406 }
407
408 /*
409 * XXXRW: This use of tun_pid is subject to error due to the
410 * fact that a reference to the tunnel can live beyond the
411 * death of the process that created it. Can we replace this
412 * with a simple busy flag?
413 */
414 mtx_lock(&tp->tun_mtx);
415 if (tp->tun_pid != 0 && tp->tun_pid != td->td_proc->p_pid) {
416 mtx_unlock(&tp->tun_mtx);
417 return (EBUSY);
418 }
419 tp->tun_pid = td->td_proc->p_pid;
420
421 tp->tun_flags |= TUN_OPEN;
422 mtx_unlock(&tp->tun_mtx);
423 ifp = TUN2IFP(tp);
424 TUNDEBUG(ifp, "open\n");
425
426 return (0);
427 }
428
429 /*
430 * tunclose - close the device - mark i/f down & delete
431 * routing info
432 */
433 static int
434 tunclose(struct cdev *dev, int foo, int bar, struct thread *td)
435 {
436 struct tun_softc *tp;
437 struct ifnet *ifp;
438 int s;
439
440 tp = dev->si_drv1;
441 ifp = TUN2IFP(tp);
442
443 mtx_lock(&tp->tun_mtx);
444 tp->tun_flags &= ~TUN_OPEN;
445 tp->tun_pid = 0;
446
447 /*
448 * junk all pending output
449 */
450 s = splimp();
451 IFQ_PURGE(&ifp->if_snd);
452 splx(s);
453 mtx_unlock(&tp->tun_mtx);
454
455 if (ifp->if_flags & IFF_UP) {
456 s = splimp();
457 if_down(ifp);
458 splx(s);
459 }
460
461 /* Delete all addresses and routes which reference this interface. */
462 if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
463 struct ifaddr *ifa;
464
465 s = splimp();
466 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
467 /* deal w/IPv4 PtP destination; unlocked read */
468 if (ifa->ifa_addr->sa_family == AF_INET) {
469 rtinit(ifa, (int)RTM_DELETE,
470 tp->tun_flags & TUN_DSTADDR ? RTF_HOST : 0);
471 } else {
472 rtinit(ifa, (int)RTM_DELETE, 0);
473 }
474 }
475 if_purgeaddrs(ifp);
476 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
477 splx(s);
478 }
479
480 funsetown(&tp->tun_sigio);
481 selwakeuppri(&tp->tun_rsel, PZERO + 1);
482 KNOTE_UNLOCKED(&tp->tun_rsel.si_note, 0);
483 TUNDEBUG (ifp, "closed\n");
484 return (0);
485 }
486
487 static int
488 tuninit(struct ifnet *ifp)
489 {
490 struct tun_softc *tp = ifp->if_softc;
491 struct ifaddr *ifa;
492 int error = 0;
493
494 TUNDEBUG(ifp, "tuninit\n");
495
496 ifp->if_flags |= IFF_UP;
497 ifp->if_drv_flags |= IFF_DRV_RUNNING;
498 getmicrotime(&ifp->if_lastchange);
499
500 #ifdef INET
501 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
502 if (ifa->ifa_addr->sa_family == AF_INET) {
503 struct sockaddr_in *si;
504
505 si = (struct sockaddr_in *)ifa->ifa_addr;
506 mtx_lock(&tp->tun_mtx);
507 if (si->sin_addr.s_addr)
508 tp->tun_flags |= TUN_IASET;
509
510 si = (struct sockaddr_in *)ifa->ifa_dstaddr;
511 if (si && si->sin_addr.s_addr)
512 tp->tun_flags |= TUN_DSTADDR;
513 mtx_unlock(&tp->tun_mtx);
514 }
515 }
516 #endif
517 return (error);
518 }
519
520 /*
521 * Process an ioctl request.
522 */
523 static int
524 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
525 {
526 struct ifreq *ifr = (struct ifreq *)data;
527 struct tun_softc *tp = ifp->if_softc;
528 struct ifstat *ifs;
529 int error = 0, s;
530
531 s = splimp();
532 switch(cmd) {
533 case SIOCGIFSTATUS:
534 ifs = (struct ifstat *)data;
535 mtx_lock(&tp->tun_mtx);
536 if (tp->tun_pid)
537 sprintf(ifs->ascii + strlen(ifs->ascii),
538 "\tOpened by PID %d\n", tp->tun_pid);
539 mtx_unlock(&tp->tun_mtx);
540 break;
541 case SIOCSIFADDR:
542 error = tuninit(ifp);
543 TUNDEBUG(ifp, "address set, error=%d\n", error);
544 break;
545 case SIOCSIFDSTADDR:
546 error = tuninit(ifp);
547 TUNDEBUG(ifp, "destination address set, error=%d\n", error);
548 break;
549 case SIOCSIFMTU:
550 ifp->if_mtu = ifr->ifr_mtu;
551 TUNDEBUG(ifp, "mtu set\n");
552 break;
553 case SIOCSIFFLAGS:
554 case SIOCADDMULTI:
555 case SIOCDELMULTI:
556 break;
557 default:
558 error = EINVAL;
559 }
560 splx(s);
561 return (error);
562 }
563
564 /*
565 * tunoutput - queue packets from higher level ready to put out.
566 */
567 static int
568 tunoutput(
569 struct ifnet *ifp,
570 struct mbuf *m0,
571 struct sockaddr *dst,
572 struct rtentry *rt)
573 {
574 struct tun_softc *tp = ifp->if_softc;
575 u_short cached_tun_flags;
576 int error;
577 u_int32_t af;
578
579 TUNDEBUG (ifp, "tunoutput\n");
580
581 #ifdef MAC
582 error = mac_check_ifnet_transmit(ifp, m0);
583 if (error) {
584 m_freem(m0);
585 return (error);
586 }
587 #endif
588
589 /* Could be unlocked read? */
590 mtx_lock(&tp->tun_mtx);
591 cached_tun_flags = tp->tun_flags;
592 mtx_unlock(&tp->tun_mtx);
593 if ((cached_tun_flags & TUN_READY) != TUN_READY) {
594 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
595 m_freem (m0);
596 return (EHOSTDOWN);
597 }
598
599 if ((ifp->if_flags & IFF_UP) != IFF_UP) {
600 m_freem (m0);
601 return (EHOSTDOWN);
602 }
603
604 /* BPF writes need to be handled specially. */
605 if (dst->sa_family == AF_UNSPEC) {
606 bcopy(dst->sa_data, &af, sizeof(af));
607 dst->sa_family = af;
608 }
609
610 if (bpf_peers_present(ifp->if_bpf)) {
611 af = dst->sa_family;
612 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m0);
613 }
614
615 /* prepend sockaddr? this may abort if the mbuf allocation fails */
616 if (cached_tun_flags & TUN_LMODE) {
617 /* allocate space for sockaddr */
618 M_PREPEND(m0, dst->sa_len, M_DONTWAIT);
619
620 /* if allocation failed drop packet */
621 if (m0 == NULL) {
622 ifp->if_iqdrops++;
623 ifp->if_oerrors++;
624 return (ENOBUFS);
625 } else {
626 bcopy(dst, m0->m_data, dst->sa_len);
627 }
628 }
629
630 if (cached_tun_flags & TUN_IFHEAD) {
631 /* Prepend the address family */
632 M_PREPEND(m0, 4, M_DONTWAIT);
633
634 /* if allocation failed drop packet */
635 if (m0 == NULL) {
636 ifp->if_iqdrops++;
637 ifp->if_oerrors++;
638 return (ENOBUFS);
639 } else
640 *(u_int32_t *)m0->m_data = htonl(dst->sa_family);
641 } else {
642 #ifdef INET
643 if (dst->sa_family != AF_INET)
644 #endif
645 {
646 m_freem(m0);
647 return (EAFNOSUPPORT);
648 }
649 }
650
651 IFQ_HANDOFF(ifp, m0, error);
652 if (error) {
653 ifp->if_collisions++;
654 return (ENOBUFS);
655 }
656 ifp->if_opackets++;
657 return (0);
658 }
659
660 /*
661 * the cdevsw interface is now pretty minimal.
662 */
663 static int
664 tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
665 {
666 int s;
667 int error;
668 struct tun_softc *tp = dev->si_drv1;
669 struct tuninfo *tunp;
670
671 switch (cmd) {
672 case TUNSIFINFO:
673 tunp = (struct tuninfo *)data;
674 if (tunp->mtu < IF_MINMTU)
675 return (EINVAL);
676 if (TUN2IFP(tp)->if_mtu != tunp->mtu) {
677 error = priv_check(td, PRIV_NET_SETIFMTU);
678 if (error)
679 return (error);
680 }
681 TUN2IFP(tp)->if_mtu = tunp->mtu;
682 TUN2IFP(tp)->if_type = tunp->type;
683 TUN2IFP(tp)->if_baudrate = tunp->baudrate;
684 break;
685 case TUNGIFINFO:
686 tunp = (struct tuninfo *)data;
687 tunp->mtu = TUN2IFP(tp)->if_mtu;
688 tunp->type = TUN2IFP(tp)->if_type;
689 tunp->baudrate = TUN2IFP(tp)->if_baudrate;
690 break;
691 case TUNSDEBUG:
692 tundebug = *(int *)data;
693 break;
694 case TUNGDEBUG:
695 *(int *)data = tundebug;
696 break;
697 case TUNSLMODE:
698 mtx_lock(&tp->tun_mtx);
699 if (*(int *)data) {
700 tp->tun_flags |= TUN_LMODE;
701 tp->tun_flags &= ~TUN_IFHEAD;
702 } else
703 tp->tun_flags &= ~TUN_LMODE;
704 mtx_unlock(&tp->tun_mtx);
705 break;
706 case TUNSIFHEAD:
707 mtx_lock(&tp->tun_mtx);
708 if (*(int *)data) {
709 tp->tun_flags |= TUN_IFHEAD;
710 tp->tun_flags &= ~TUN_LMODE;
711 } else
712 tp->tun_flags &= ~TUN_IFHEAD;
713 mtx_unlock(&tp->tun_mtx);
714 break;
715 case TUNGIFHEAD:
716 /* Could be unlocked read? */
717 mtx_lock(&tp->tun_mtx);
718 *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
719 mtx_unlock(&tp->tun_mtx);
720 break;
721 case TUNSIFMODE:
722 /* deny this if UP */
723 if (TUN2IFP(tp)->if_flags & IFF_UP)
724 return(EBUSY);
725
726 switch (*(int *)data & ~IFF_MULTICAST) {
727 case IFF_POINTOPOINT:
728 case IFF_BROADCAST:
729 TUN2IFP(tp)->if_flags &=
730 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
731 TUN2IFP(tp)->if_flags |= *(int *)data;
732 break;
733 default:
734 return(EINVAL);
735 }
736 break;
737 case TUNSIFPID:
738 mtx_lock(&tp->tun_mtx);
739 tp->tun_pid = curthread->td_proc->p_pid;
740 mtx_unlock(&tp->tun_mtx);
741 break;
742 case FIONBIO:
743 break;
744 case FIOASYNC:
745 mtx_lock(&tp->tun_mtx);
746 if (*(int *)data)
747 tp->tun_flags |= TUN_ASYNC;
748 else
749 tp->tun_flags &= ~TUN_ASYNC;
750 mtx_unlock(&tp->tun_mtx);
751 break;
752 case FIONREAD:
753 s = splimp();
754 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) {
755 struct mbuf *mb;
756 IFQ_LOCK(&TUN2IFP(tp)->if_snd);
757 IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb);
758 for( *(int *)data = 0; mb != 0; mb = mb->m_next)
759 *(int *)data += mb->m_len;
760 IFQ_UNLOCK(&TUN2IFP(tp)->if_snd);
761 } else
762 *(int *)data = 0;
763 splx(s);
764 break;
765 case FIOSETOWN:
766 return (fsetown(*(int *)data, &tp->tun_sigio));
767
768 case FIOGETOWN:
769 *(int *)data = fgetown(&tp->tun_sigio);
770 return (0);
771
772 /* This is deprecated, FIOSETOWN should be used instead. */
773 case TIOCSPGRP:
774 return (fsetown(-(*(int *)data), &tp->tun_sigio));
775
776 /* This is deprecated, FIOGETOWN should be used instead. */
777 case TIOCGPGRP:
778 *(int *)data = -fgetown(&tp->tun_sigio);
779 return (0);
780
781 default:
782 return (ENOTTY);
783 }
784 return (0);
785 }
786
787 /*
788 * The cdevsw 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
792 tunread(struct cdev *dev, struct uio *uio, int flag)
793 {
794 struct tun_softc *tp = dev->si_drv1;
795 struct ifnet *ifp = TUN2IFP(tp);
796 struct mbuf *m;
797 int error=0, len, s;
798
799 TUNDEBUG (ifp, "read\n");
800 mtx_lock(&tp->tun_mtx);
801 if ((tp->tun_flags & TUN_READY) != TUN_READY) {
802 mtx_unlock(&tp->tun_mtx);
803 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
804 return (EHOSTDOWN);
805 }
806
807 tp->tun_flags &= ~TUN_RWAIT;
808 mtx_unlock(&tp->tun_mtx);
809
810 s = splimp();
811 do {
812 IFQ_DEQUEUE(&ifp->if_snd, m);
813 if (m == NULL) {
814 if (flag & O_NONBLOCK) {
815 splx(s);
816 return (EWOULDBLOCK);
817 }
818 mtx_lock(&tp->tun_mtx);
819 tp->tun_flags |= TUN_RWAIT;
820 mtx_unlock(&tp->tun_mtx);
821 if ((error = tsleep(tp, PCATCH | (PZERO + 1),
822 "tunread", 0)) != 0) {
823 splx(s);
824 return (error);
825 }
826 }
827 } while (m == NULL);
828 splx(s);
829
830 while (m && uio->uio_resid > 0 && error == 0) {
831 len = min(uio->uio_resid, m->m_len);
832 if (len != 0)
833 error = uiomove(mtod(m, void *), len, uio);
834 m = m_free(m);
835 }
836
837 if (m) {
838 TUNDEBUG(ifp, "Dropping mbuf\n");
839 m_freem(m);
840 }
841 return (error);
842 }
843
844 /*
845 * the cdevsw write interface - an atomic write is a packet - or else!
846 */
847 static int
848 tunwrite(struct cdev *dev, struct uio *uio, int flag)
849 {
850 struct tun_softc *tp = dev->si_drv1;
851 struct ifnet *ifp = TUN2IFP(tp);
852 struct mbuf *m;
853 int error = 0;
854 uint32_t family;
855 int isr;
856
857 TUNDEBUG(ifp, "tunwrite\n");
858
859 if ((ifp->if_flags & IFF_UP) != IFF_UP)
860 /* ignore silently */
861 return (0);
862
863 if (uio->uio_resid == 0)
864 return (0);
865
866 if (uio->uio_resid < 0 || uio->uio_resid > TUNMRU) {
867 TUNDEBUG(ifp, "len=%d!\n", uio->uio_resid);
868 return (EIO);
869 }
870
871 if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, 0, M_PKTHDR)) == NULL) {
872 ifp->if_ierrors++;
873 return (error);
874 }
875
876 m->m_pkthdr.rcvif = ifp;
877 #ifdef MAC
878 mac_create_mbuf_from_ifnet(ifp, m);
879 #endif
880
881 /* Could be unlocked read? */
882 mtx_lock(&tp->tun_mtx);
883 if (tp->tun_flags & TUN_IFHEAD) {
884 mtx_unlock(&tp->tun_mtx);
885 if (m->m_len < sizeof(family) &&
886 (m = m_pullup(m, sizeof(family))) == NULL)
887 return (ENOBUFS);
888 family = ntohl(*mtod(m, u_int32_t *));
889 m_adj(m, sizeof(family));
890 } else {
891 mtx_unlock(&tp->tun_mtx);
892 family = AF_INET;
893 }
894
895 BPF_MTAP2(ifp, &family, sizeof(family), m);
896
897 switch (family) {
898 #ifdef INET
899 case AF_INET:
900 isr = NETISR_IP;
901 break;
902 #endif
903 #ifdef INET6
904 case AF_INET6:
905 isr = NETISR_IPV6;
906 break;
907 #endif
908 #ifdef IPX
909 case AF_IPX:
910 isr = NETISR_IPX;
911 break;
912 #endif
913 #ifdef NETATALK
914 case AF_APPLETALK:
915 isr = NETISR_ATALK2;
916 break;
917 #endif
918 default:
919 m_freem(m);
920 return (EAFNOSUPPORT);
921 }
922 /* First chunk of an mbuf contains good junk */
923 if (harvest.point_to_point)
924 random_harvest(m, 16, 3, 0, RANDOM_NET);
925 ifp->if_ibytes += m->m_pkthdr.len;
926 ifp->if_ipackets++;
927 netisr_dispatch(isr, m);
928 return (0);
929 }
930
931 /*
932 * tunpoll - the poll interface, this is only useful on reads
933 * really. The write detect always returns true, write never blocks
934 * anyway, it either accepts the packet or drops it.
935 */
936 static int
937 tunpoll(struct cdev *dev, int events, struct thread *td)
938 {
939 int s;
940 struct tun_softc *tp = dev->si_drv1;
941 struct ifnet *ifp = TUN2IFP(tp);
942 int revents = 0;
943 struct mbuf *m;
944
945 s = splimp();
946 TUNDEBUG(ifp, "tunpoll\n");
947
948 if (events & (POLLIN | POLLRDNORM)) {
949 IFQ_LOCK(&ifp->if_snd);
950 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
951 if (m != NULL) {
952 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len);
953 revents |= events & (POLLIN | POLLRDNORM);
954 } else {
955 TUNDEBUG(ifp, "tunpoll waiting\n");
956 selrecord(td, &tp->tun_rsel);
957 }
958 IFQ_UNLOCK(&ifp->if_snd);
959 }
960 if (events & (POLLOUT | POLLWRNORM))
961 revents |= events & (POLLOUT | POLLWRNORM);
962
963 splx(s);
964 return (revents);
965 }
966
967 /*
968 * tunkqfilter - support for the kevent() system call.
969 */
970 static int
971 tunkqfilter(struct cdev *dev, struct knote *kn)
972 {
973 int s;
974 struct tun_softc *tp = dev->si_drv1;
975 struct ifnet *ifp = TUN2IFP(tp);
976
977 s = splimp();
978 switch(kn->kn_filter) {
979 case EVFILT_READ:
980 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n",
981 ifp->if_xname, minor(dev));
982 kn->kn_fop = &tun_read_filterops;
983 break;
984
985 case EVFILT_WRITE:
986 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n",
987 ifp->if_xname, minor(dev));
988 kn->kn_fop = &tun_write_filterops;
989 break;
990
991 default:
992 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n",
993 ifp->if_xname, minor(dev));
994 splx(s);
995 return(EINVAL);
996 }
997 splx(s);
998
999 kn->kn_hook = (caddr_t) dev;
1000 knlist_add(&tp->tun_rsel.si_note, kn, 0);
1001
1002 return (0);
1003 }
1004
1005 /*
1006 * Return true of there is data in the interface queue.
1007 */
1008 static int
1009 tunkqread(struct knote *kn, long hint)
1010 {
1011 int ret, s;
1012 struct cdev *dev = (struct cdev *)(kn->kn_hook);
1013 struct tun_softc *tp = dev->si_drv1;
1014 struct ifnet *ifp = TUN2IFP(tp);
1015
1016 s = splimp();
1017 if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) {
1018 TUNDEBUG(ifp,
1019 "%s have data in the queue. Len = %d, minor = %#x\n",
1020 ifp->if_xname, ifp->if_snd.ifq_len, minor(dev));
1021 ret = 1;
1022 } else {
1023 TUNDEBUG(ifp,
1024 "%s waiting for data, minor = %#x\n", ifp->if_xname,
1025 minor(dev));
1026 ret = 0;
1027 }
1028 splx(s);
1029
1030 return (ret);
1031 }
1032
1033 /*
1034 * Always can write, always return MTU in kn->data.
1035 */
1036 static int
1037 tunkqwrite(struct knote *kn, long hint)
1038 {
1039 int s;
1040 struct tun_softc *tp = ((struct cdev *)kn->kn_hook)->si_drv1;
1041 struct ifnet *ifp = TUN2IFP(tp);
1042
1043 s = splimp();
1044 kn->kn_data = ifp->if_mtu;
1045 splx(s);
1046
1047 return (1);
1048 }
1049
1050 static void
1051 tunkqdetach(struct knote *kn)
1052 {
1053 struct tun_softc *tp = ((struct cdev *)kn->kn_hook)->si_drv1;
1054
1055 knlist_remove(&tp->tun_rsel.si_note, kn, 0);
1056 }
Cache object: e2eb02c28888e4ad3bf7829092d45c60
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