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/11.2/sys/net/if_tun.c 326691 2017-12-08 15:23:17Z hselasky $
17 */
18
19 #include "opt_inet.h"
20 #include "opt_inet6.h"
21
22 #include <sys/param.h>
23 #include <sys/priv.h>
24 #include <sys/proc.h>
25 #include <sys/systm.h>
26 #include <sys/jail.h>
27 #include <sys/mbuf.h>
28 #include <sys/module.h>
29 #include <sys/socket.h>
30 #include <sys/fcntl.h>
31 #include <sys/filio.h>
32 #include <sys/sockio.h>
33 #include <sys/ttycom.h>
34 #include <sys/poll.h>
35 #include <sys/selinfo.h>
36 #include <sys/signalvar.h>
37 #include <sys/filedesc.h>
38 #include <sys/kernel.h>
39 #include <sys/sysctl.h>
40 #include <sys/conf.h>
41 #include <sys/uio.h>
42 #include <sys/malloc.h>
43 #include <sys/random.h>
44
45 #include <net/if.h>
46 #include <net/if_var.h>
47 #include <net/if_clone.h>
48 #include <net/if_types.h>
49 #include <net/netisr.h>
50 #include <net/route.h>
51 #include <net/vnet.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 #include <sys/condvar.h>
60
61 #include <security/mac/mac_framework.h>
62
63 /*
64 * tun_list is protected by global tunmtx. Other mutable fields are
65 * protected by tun->tun_mtx, or by their owning subsystem. tun_dev is
66 * static for the duration of a tunnel interface.
67 */
68 struct tun_softc {
69 TAILQ_ENTRY(tun_softc) tun_list;
70 struct cdev *tun_dev;
71 u_short tun_flags; /* misc flags */
72 #define TUN_OPEN 0x0001
73 #define TUN_INITED 0x0002
74 #define TUN_RCOLL 0x0004
75 #define TUN_IASET 0x0008
76 #define TUN_DSTADDR 0x0010
77 #define TUN_LMODE 0x0020
78 #define TUN_RWAIT 0x0040
79 #define TUN_ASYNC 0x0080
80 #define TUN_IFHEAD 0x0100
81
82 #define TUN_READY (TUN_OPEN | TUN_INITED)
83
84 /*
85 * XXXRW: tun_pid is used to exclusively lock /dev/tun. Is this
86 * actually needed? Can we just return EBUSY if already open?
87 * Problem is that this involved inherent races when a tun device
88 * is handed off from one process to another, as opposed to just
89 * being slightly stale informationally.
90 */
91 pid_t tun_pid; /* owning pid */
92 struct ifnet *tun_ifp; /* the interface */
93 struct sigio *tun_sigio; /* information for async I/O */
94 struct selinfo tun_rsel; /* read select */
95 struct mtx tun_mtx; /* protect mutable softc fields */
96 struct cv tun_cv; /* protect against ref'd dev destroy */
97 };
98 #define TUN2IFP(sc) ((sc)->tun_ifp)
99
100 #define TUNDEBUG if (tundebug) if_printf
101
102 /*
103 * All mutable global variables in if_tun are locked using tunmtx, with
104 * the exception of tundebug, which is used unlocked, and tunclones,
105 * which is static after setup.
106 */
107 static struct mtx tunmtx;
108 static const char tunname[] = "tun";
109 static MALLOC_DEFINE(M_TUN, tunname, "Tunnel Interface");
110 static int tundebug = 0;
111 static int tundclone = 1;
112 static struct clonedevs *tunclones;
113 static TAILQ_HEAD(,tun_softc) tunhead = TAILQ_HEAD_INITIALIZER(tunhead);
114 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");
115
116 SYSCTL_DECL(_net_link);
117 static SYSCTL_NODE(_net_link, OID_AUTO, tun, CTLFLAG_RW, 0,
118 "IP tunnel software network interface.");
119 SYSCTL_INT(_net_link_tun, OID_AUTO, devfs_cloning, CTLFLAG_RWTUN, &tundclone, 0,
120 "Enable legacy devfs interface creation.");
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 void tuninit(struct ifnet *);
127 static int tunmodevent(module_t, int, void *);
128 static int tunoutput(struct ifnet *, struct mbuf *,
129 const struct sockaddr *, struct route *ro);
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 static struct if_clone *tun_cloner;
135
136 static d_open_t tunopen;
137 static d_close_t tunclose;
138 static d_read_t tunread;
139 static d_write_t tunwrite;
140 static d_ioctl_t tunioctl;
141 static d_poll_t tunpoll;
142 static d_kqfilter_t tunkqfilter;
143
144 static int tunkqread(struct knote *, long);
145 static int tunkqwrite(struct knote *, long);
146 static void tunkqdetach(struct knote *);
147
148 static struct filterops tun_read_filterops = {
149 .f_isfd = 1,
150 .f_attach = NULL,
151 .f_detach = tunkqdetach,
152 .f_event = tunkqread,
153 };
154
155 static struct filterops tun_write_filterops = {
156 .f_isfd = 1,
157 .f_attach = NULL,
158 .f_detach = tunkqdetach,
159 .f_event = tunkqwrite,
160 };
161
162 static struct cdevsw tun_cdevsw = {
163 .d_version = D_VERSION,
164 .d_flags = D_NEEDMINOR,
165 .d_open = tunopen,
166 .d_close = tunclose,
167 .d_read = tunread,
168 .d_write = tunwrite,
169 .d_ioctl = tunioctl,
170 .d_poll = tunpoll,
171 .d_kqfilter = tunkqfilter,
172 .d_name = tunname,
173 };
174
175 static int
176 tun_clone_create(struct if_clone *ifc, int unit, caddr_t params)
177 {
178 struct cdev *dev;
179 int i;
180
181 /* find any existing device, or allocate new unit number */
182 i = clone_create(&tunclones, &tun_cdevsw, &unit, &dev, 0);
183 if (i) {
184 /* No preexisting struct cdev *, create one */
185 dev = make_dev(&tun_cdevsw, unit,
186 UID_UUCP, GID_DIALER, 0600, "%s%d", tunname, unit);
187 }
188 tuncreate(tunname, dev);
189
190 return (0);
191 }
192
193 static void
194 tunclone(void *arg, struct ucred *cred, char *name, int namelen,
195 struct cdev **dev)
196 {
197 char devname[SPECNAMELEN + 1];
198 int u, i, append_unit;
199
200 if (*dev != NULL)
201 return;
202
203 /*
204 * If tun cloning is enabled, only the superuser can create an
205 * interface.
206 */
207 if (!tundclone || priv_check_cred(cred, PRIV_NET_IFCREATE, 0) != 0)
208 return;
209
210 if (strcmp(name, tunname) == 0) {
211 u = -1;
212 } else if (dev_stdclone(name, NULL, tunname, &u) != 1)
213 return; /* Don't recognise the name */
214 if (u != -1 && u > IF_MAXUNIT)
215 return; /* Unit number too high */
216
217 if (u == -1)
218 append_unit = 1;
219 else
220 append_unit = 0;
221
222 CURVNET_SET(CRED_TO_VNET(cred));
223 /* find any existing device, or allocate new unit number */
224 i = clone_create(&tunclones, &tun_cdevsw, &u, dev, 0);
225 if (i) {
226 if (append_unit) {
227 namelen = snprintf(devname, sizeof(devname), "%s%d",
228 name, u);
229 name = devname;
230 }
231 /* No preexisting struct cdev *, create one */
232 *dev = make_dev_credf(MAKEDEV_REF, &tun_cdevsw, u, cred,
233 UID_UUCP, GID_DIALER, 0600, "%s", name);
234 }
235
236 if_clone_create(name, namelen, NULL);
237 CURVNET_RESTORE();
238 }
239
240 static void
241 tun_destroy(struct tun_softc *tp)
242 {
243 struct cdev *dev;
244
245 mtx_lock(&tp->tun_mtx);
246 if ((tp->tun_flags & TUN_OPEN) != 0)
247 cv_wait_unlock(&tp->tun_cv, &tp->tun_mtx);
248 else
249 mtx_unlock(&tp->tun_mtx);
250
251 CURVNET_SET(TUN2IFP(tp)->if_vnet);
252 dev = tp->tun_dev;
253 bpfdetach(TUN2IFP(tp));
254 if_detach(TUN2IFP(tp));
255 if_free(TUN2IFP(tp));
256 destroy_dev(dev);
257 seldrain(&tp->tun_rsel);
258 knlist_clear(&tp->tun_rsel.si_note, 0);
259 knlist_destroy(&tp->tun_rsel.si_note);
260 mtx_destroy(&tp->tun_mtx);
261 cv_destroy(&tp->tun_cv);
262 free(tp, M_TUN);
263 CURVNET_RESTORE();
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 tun_cloner = if_clone_simple(tunname, tun_clone_create,
291 tun_clone_destroy, 0);
292 break;
293 case MOD_UNLOAD:
294 if_clone_detach(tun_cloner);
295 EVENTHANDLER_DEREGISTER(dev_clone, tag);
296 drain_dev_clone_events();
297
298 mtx_lock(&tunmtx);
299 while ((tp = TAILQ_FIRST(&tunhead)) != NULL) {
300 TAILQ_REMOVE(&tunhead, tp, tun_list);
301 mtx_unlock(&tunmtx);
302 tun_destroy(tp);
303 mtx_lock(&tunmtx);
304 }
305 mtx_unlock(&tunmtx);
306 clone_cleanup(&tunclones);
307 mtx_destroy(&tunmtx);
308 break;
309 default:
310 return EOPNOTSUPP;
311 }
312 return 0;
313 }
314
315 static moduledata_t tun_mod = {
316 "if_tun",
317 tunmodevent,
318 0
319 };
320
321 DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
322 MODULE_VERSION(if_tun, 1);
323
324 static void
325 tunstart(struct ifnet *ifp)
326 {
327 struct tun_softc *tp = ifp->if_softc;
328 struct mbuf *m;
329
330 TUNDEBUG(ifp,"%s starting\n", ifp->if_xname);
331 if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
332 IFQ_LOCK(&ifp->if_snd);
333 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
334 if (m == NULL) {
335 IFQ_UNLOCK(&ifp->if_snd);
336 return;
337 }
338 IFQ_UNLOCK(&ifp->if_snd);
339 }
340
341 mtx_lock(&tp->tun_mtx);
342 if (tp->tun_flags & TUN_RWAIT) {
343 tp->tun_flags &= ~TUN_RWAIT;
344 wakeup(tp);
345 }
346 selwakeuppri(&tp->tun_rsel, PZERO + 1);
347 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
348 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) {
349 mtx_unlock(&tp->tun_mtx);
350 pgsigio(&tp->tun_sigio, SIGIO, 0);
351 } else
352 mtx_unlock(&tp->tun_mtx);
353 }
354
355 /* XXX: should return an error code so it can fail. */
356 static void
357 tuncreate(const char *name, struct cdev *dev)
358 {
359 struct tun_softc *sc;
360 struct ifnet *ifp;
361
362 sc = malloc(sizeof(*sc), M_TUN, M_WAITOK | M_ZERO);
363 mtx_init(&sc->tun_mtx, "tun_mtx", NULL, MTX_DEF);
364 cv_init(&sc->tun_cv, "tun_condvar");
365 sc->tun_flags = TUN_INITED;
366 sc->tun_dev = dev;
367 mtx_lock(&tunmtx);
368 TAILQ_INSERT_TAIL(&tunhead, sc, tun_list);
369 mtx_unlock(&tunmtx);
370
371 ifp = sc->tun_ifp = if_alloc(IFT_PPP);
372 if (ifp == NULL)
373 panic("%s%d: failed to if_alloc() interface.\n",
374 name, dev2unit(dev));
375 if_initname(ifp, name, dev2unit(dev));
376 ifp->if_mtu = TUNMTU;
377 ifp->if_ioctl = tunifioctl;
378 ifp->if_output = tunoutput;
379 ifp->if_start = tunstart;
380 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
381 ifp->if_softc = sc;
382 IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
383 ifp->if_snd.ifq_drv_maxlen = 0;
384 IFQ_SET_READY(&ifp->if_snd);
385 knlist_init_mtx(&sc->tun_rsel.si_note, &sc->tun_mtx);
386 ifp->if_capabilities |= IFCAP_LINKSTATE;
387 ifp->if_capenable |= IFCAP_LINKSTATE;
388
389 if_attach(ifp);
390 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
391 dev->si_drv1 = sc;
392 TUNDEBUG(ifp, "interface %s is created, minor = %#x\n",
393 ifp->if_xname, dev2unit(dev));
394 }
395
396 static int
397 tunopen(struct cdev *dev, int flag, int mode, struct thread *td)
398 {
399 struct ifnet *ifp;
400 struct tun_softc *tp;
401
402 /*
403 * XXXRW: Non-atomic test and set of dev->si_drv1 requires
404 * synchronization.
405 */
406 tp = dev->si_drv1;
407 if (!tp) {
408 tuncreate(tunname, dev);
409 tp = dev->si_drv1;
410 }
411
412 /*
413 * XXXRW: This use of tun_pid is subject to error due to the
414 * fact that a reference to the tunnel can live beyond the
415 * death of the process that created it. Can we replace this
416 * with a simple busy flag?
417 */
418 mtx_lock(&tp->tun_mtx);
419 if (tp->tun_pid != 0 && tp->tun_pid != td->td_proc->p_pid) {
420 mtx_unlock(&tp->tun_mtx);
421 return (EBUSY);
422 }
423 tp->tun_pid = td->td_proc->p_pid;
424
425 tp->tun_flags |= TUN_OPEN;
426 ifp = TUN2IFP(tp);
427 if_link_state_change(ifp, LINK_STATE_UP);
428 TUNDEBUG(ifp, "open\n");
429 mtx_unlock(&tp->tun_mtx);
430
431 return (0);
432 }
433
434 /*
435 * tunclose - close the device - mark i/f down & delete
436 * routing info
437 */
438 static int
439 tunclose(struct cdev *dev, int foo, int bar, struct thread *td)
440 {
441 struct tun_softc *tp;
442 struct ifnet *ifp;
443
444 tp = dev->si_drv1;
445 ifp = TUN2IFP(tp);
446
447 mtx_lock(&tp->tun_mtx);
448 tp->tun_flags &= ~TUN_OPEN;
449 tp->tun_pid = 0;
450
451 /*
452 * junk all pending output
453 */
454 CURVNET_SET(ifp->if_vnet);
455 IFQ_PURGE(&ifp->if_snd);
456
457 if (ifp->if_flags & IFF_UP) {
458 mtx_unlock(&tp->tun_mtx);
459 if_down(ifp);
460 mtx_lock(&tp->tun_mtx);
461 }
462
463 /* Delete all addresses and routes which reference this interface. */
464 if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
465 struct ifaddr *ifa;
466
467 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
468 mtx_unlock(&tp->tun_mtx);
469 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
470 /* deal w/IPv4 PtP destination; unlocked read */
471 if (ifa->ifa_addr->sa_family == AF_INET) {
472 rtinit(ifa, (int)RTM_DELETE,
473 tp->tun_flags & TUN_DSTADDR ? RTF_HOST : 0);
474 } else {
475 rtinit(ifa, (int)RTM_DELETE, 0);
476 }
477 }
478 if_purgeaddrs(ifp);
479 mtx_lock(&tp->tun_mtx);
480 }
481 if_link_state_change(ifp, LINK_STATE_DOWN);
482 CURVNET_RESTORE();
483
484 funsetown(&tp->tun_sigio);
485 selwakeuppri(&tp->tun_rsel, PZERO + 1);
486 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
487 TUNDEBUG (ifp, "closed\n");
488
489 cv_broadcast(&tp->tun_cv);
490 mtx_unlock(&tp->tun_mtx);
491 return (0);
492 }
493
494 static void
495 tuninit(struct ifnet *ifp)
496 {
497 struct tun_softc *tp = ifp->if_softc;
498 #ifdef INET
499 struct ifaddr *ifa;
500 #endif
501
502 TUNDEBUG(ifp, "tuninit\n");
503
504 mtx_lock(&tp->tun_mtx);
505 ifp->if_flags |= IFF_UP;
506 ifp->if_drv_flags |= IFF_DRV_RUNNING;
507 getmicrotime(&ifp->if_lastchange);
508
509 #ifdef INET
510 if_addr_rlock(ifp);
511 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
512 if (ifa->ifa_addr->sa_family == AF_INET) {
513 struct sockaddr_in *si;
514
515 si = (struct sockaddr_in *)ifa->ifa_addr;
516 if (si->sin_addr.s_addr)
517 tp->tun_flags |= TUN_IASET;
518
519 si = (struct sockaddr_in *)ifa->ifa_dstaddr;
520 if (si && si->sin_addr.s_addr)
521 tp->tun_flags |= TUN_DSTADDR;
522 }
523 }
524 if_addr_runlock(ifp);
525 #endif
526 mtx_unlock(&tp->tun_mtx);
527 }
528
529 /*
530 * Process an ioctl request.
531 */
532 static int
533 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
534 {
535 struct ifreq *ifr = (struct ifreq *)data;
536 struct tun_softc *tp = ifp->if_softc;
537 struct ifstat *ifs;
538 int error = 0;
539
540 switch(cmd) {
541 case SIOCGIFSTATUS:
542 ifs = (struct ifstat *)data;
543 mtx_lock(&tp->tun_mtx);
544 if (tp->tun_pid)
545 snprintf(ifs->ascii, sizeof(ifs->ascii),
546 "\tOpened by PID %d\n", tp->tun_pid);
547 else
548 ifs->ascii[0] = '\0';
549 mtx_unlock(&tp->tun_mtx);
550 break;
551 case SIOCSIFADDR:
552 tuninit(ifp);
553 TUNDEBUG(ifp, "address set\n");
554 break;
555 case SIOCSIFMTU:
556 ifp->if_mtu = ifr->ifr_mtu;
557 TUNDEBUG(ifp, "mtu set\n");
558 break;
559 case SIOCSIFFLAGS:
560 case SIOCADDMULTI:
561 case SIOCDELMULTI:
562 break;
563 default:
564 error = EINVAL;
565 }
566 return (error);
567 }
568
569 /*
570 * tunoutput - queue packets from higher level ready to put out.
571 */
572 static int
573 tunoutput(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
574 struct route *ro)
575 {
576 struct tun_softc *tp = ifp->if_softc;
577 u_short cached_tun_flags;
578 int error;
579 u_int32_t af;
580
581 TUNDEBUG (ifp, "tunoutput\n");
582
583 #ifdef MAC
584 error = mac_ifnet_check_transmit(ifp, m0);
585 if (error) {
586 m_freem(m0);
587 return (error);
588 }
589 #endif
590
591 /* Could be unlocked read? */
592 mtx_lock(&tp->tun_mtx);
593 cached_tun_flags = tp->tun_flags;
594 mtx_unlock(&tp->tun_mtx);
595 if ((cached_tun_flags & TUN_READY) != TUN_READY) {
596 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
597 m_freem (m0);
598 return (EHOSTDOWN);
599 }
600
601 if ((ifp->if_flags & IFF_UP) != IFF_UP) {
602 m_freem (m0);
603 return (EHOSTDOWN);
604 }
605
606 /* BPF writes need to be handled specially. */
607 if (dst->sa_family == AF_UNSPEC)
608 bcopy(dst->sa_data, &af, sizeof(af));
609 else
610 af = dst->sa_family;
611
612 if (bpf_peers_present(ifp->if_bpf))
613 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m0);
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_NOWAIT);
619
620 /* if allocation failed drop packet */
621 if (m0 == NULL) {
622 if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
623 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
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_NOWAIT);
633
634 /* if allocation failed drop packet */
635 if (m0 == NULL) {
636 if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
637 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
638 return (ENOBUFS);
639 } else
640 *(u_int32_t *)m0->m_data = htonl(af);
641 } else {
642 #ifdef INET
643 if (af != AF_INET)
644 #endif
645 {
646 m_freem(m0);
647 return (EAFNOSUPPORT);
648 }
649 }
650
651 error = (ifp->if_transmit)(ifp, m0);
652 if (error)
653 return (ENOBUFS);
654 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
655 return (0);
656 }
657
658 /*
659 * the cdevsw interface is now pretty minimal.
660 */
661 static int
662 tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag,
663 struct thread *td)
664 {
665 int error;
666 struct tun_softc *tp = dev->si_drv1;
667 struct tuninfo *tunp;
668
669 switch (cmd) {
670 case TUNSIFINFO:
671 tunp = (struct tuninfo *)data;
672 if (tunp->mtu < IF_MINMTU)
673 return (EINVAL);
674 if (TUN2IFP(tp)->if_mtu != tunp->mtu) {
675 error = priv_check(td, PRIV_NET_SETIFMTU);
676 if (error)
677 return (error);
678 }
679 if (TUN2IFP(tp)->if_type != tunp->type)
680 return (EPROTOTYPE);
681 mtx_lock(&tp->tun_mtx);
682 TUN2IFP(tp)->if_mtu = tunp->mtu;
683 TUN2IFP(tp)->if_baudrate = tunp->baudrate;
684 mtx_unlock(&tp->tun_mtx);
685 break;
686 case TUNGIFINFO:
687 tunp = (struct tuninfo *)data;
688 mtx_lock(&tp->tun_mtx);
689 tunp->mtu = TUN2IFP(tp)->if_mtu;
690 tunp->type = TUN2IFP(tp)->if_type;
691 tunp->baudrate = TUN2IFP(tp)->if_baudrate;
692 mtx_unlock(&tp->tun_mtx);
693 break;
694 case TUNSDEBUG:
695 tundebug = *(int *)data;
696 break;
697 case TUNGDEBUG:
698 *(int *)data = tundebug;
699 break;
700 case TUNSLMODE:
701 mtx_lock(&tp->tun_mtx);
702 if (*(int *)data) {
703 tp->tun_flags |= TUN_LMODE;
704 tp->tun_flags &= ~TUN_IFHEAD;
705 } else
706 tp->tun_flags &= ~TUN_LMODE;
707 mtx_unlock(&tp->tun_mtx);
708 break;
709 case TUNSIFHEAD:
710 mtx_lock(&tp->tun_mtx);
711 if (*(int *)data) {
712 tp->tun_flags |= TUN_IFHEAD;
713 tp->tun_flags &= ~TUN_LMODE;
714 } else
715 tp->tun_flags &= ~TUN_IFHEAD;
716 mtx_unlock(&tp->tun_mtx);
717 break;
718 case TUNGIFHEAD:
719 mtx_lock(&tp->tun_mtx);
720 *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
721 mtx_unlock(&tp->tun_mtx);
722 break;
723 case TUNSIFMODE:
724 /* deny this if UP */
725 if (TUN2IFP(tp)->if_flags & IFF_UP)
726 return(EBUSY);
727
728 switch (*(int *)data & ~IFF_MULTICAST) {
729 case IFF_POINTOPOINT:
730 case IFF_BROADCAST:
731 mtx_lock(&tp->tun_mtx);
732 TUN2IFP(tp)->if_flags &=
733 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
734 TUN2IFP(tp)->if_flags |= *(int *)data;
735 mtx_unlock(&tp->tun_mtx);
736 break;
737 default:
738 return(EINVAL);
739 }
740 break;
741 case TUNSIFPID:
742 mtx_lock(&tp->tun_mtx);
743 tp->tun_pid = curthread->td_proc->p_pid;
744 mtx_unlock(&tp->tun_mtx);
745 break;
746 case FIONBIO:
747 break;
748 case FIOASYNC:
749 mtx_lock(&tp->tun_mtx);
750 if (*(int *)data)
751 tp->tun_flags |= TUN_ASYNC;
752 else
753 tp->tun_flags &= ~TUN_ASYNC;
754 mtx_unlock(&tp->tun_mtx);
755 break;
756 case FIONREAD:
757 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) {
758 struct mbuf *mb;
759 IFQ_LOCK(&TUN2IFP(tp)->if_snd);
760 IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb);
761 for (*(int *)data = 0; mb != NULL; mb = mb->m_next)
762 *(int *)data += mb->m_len;
763 IFQ_UNLOCK(&TUN2IFP(tp)->if_snd);
764 } else
765 *(int *)data = 0;
766 break;
767 case FIOSETOWN:
768 return (fsetown(*(int *)data, &tp->tun_sigio));
769
770 case FIOGETOWN:
771 *(int *)data = fgetown(&tp->tun_sigio);
772 return (0);
773
774 /* This is deprecated, FIOSETOWN should be used instead. */
775 case TIOCSPGRP:
776 return (fsetown(-(*(int *)data), &tp->tun_sigio));
777
778 /* This is deprecated, FIOGETOWN should be used instead. */
779 case TIOCGPGRP:
780 *(int *)data = -fgetown(&tp->tun_sigio);
781 return (0);
782
783 default:
784 return (ENOTTY);
785 }
786 return (0);
787 }
788
789 /*
790 * The cdevsw read interface - reads a packet at a time, or at
791 * least as much of a packet as can be read.
792 */
793 static int
794 tunread(struct cdev *dev, struct uio *uio, int flag)
795 {
796 struct tun_softc *tp = dev->si_drv1;
797 struct ifnet *ifp = TUN2IFP(tp);
798 struct mbuf *m;
799 int error=0, len;
800
801 TUNDEBUG (ifp, "read\n");
802 mtx_lock(&tp->tun_mtx);
803 if ((tp->tun_flags & TUN_READY) != TUN_READY) {
804 mtx_unlock(&tp->tun_mtx);
805 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
806 return (EHOSTDOWN);
807 }
808
809 tp->tun_flags &= ~TUN_RWAIT;
810
811 do {
812 IFQ_DEQUEUE(&ifp->if_snd, m);
813 if (m == NULL) {
814 if (flag & O_NONBLOCK) {
815 mtx_unlock(&tp->tun_mtx);
816 return (EWOULDBLOCK);
817 }
818 tp->tun_flags |= TUN_RWAIT;
819 error = mtx_sleep(tp, &tp->tun_mtx, PCATCH | (PZERO + 1),
820 "tunread", 0);
821 if (error != 0) {
822 mtx_unlock(&tp->tun_mtx);
823 return (error);
824 }
825 }
826 } while (m == NULL);
827 mtx_unlock(&tp->tun_mtx);
828
829 while (m && uio->uio_resid > 0 && error == 0) {
830 len = min(uio->uio_resid, m->m_len);
831 if (len != 0)
832 error = uiomove(mtod(m, void *), len, uio);
833 m = m_free(m);
834 }
835
836 if (m) {
837 TUNDEBUG(ifp, "Dropping mbuf\n");
838 m_freem(m);
839 }
840 return (error);
841 }
842
843 /*
844 * the cdevsw write interface - an atomic write is a packet - or else!
845 */
846 static int
847 tunwrite(struct cdev *dev, struct uio *uio, int flag)
848 {
849 struct tun_softc *tp = dev->si_drv1;
850 struct ifnet *ifp = TUN2IFP(tp);
851 struct mbuf *m;
852 uint32_t family, mru;
853 int isr;
854
855 TUNDEBUG(ifp, "tunwrite\n");
856
857 if ((ifp->if_flags & IFF_UP) != IFF_UP)
858 /* ignore silently */
859 return (0);
860
861 if (uio->uio_resid == 0)
862 return (0);
863
864 mru = TUNMRU;
865 if (tp->tun_flags & TUN_IFHEAD)
866 mru += sizeof(family);
867 if (uio->uio_resid < 0 || uio->uio_resid > mru) {
868 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid);
869 return (EIO);
870 }
871
872 if ((m = m_uiotombuf(uio, M_NOWAIT, 0, 0, M_PKTHDR)) == NULL) {
873 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
874 return (ENOBUFS);
875 }
876
877 m->m_pkthdr.rcvif = ifp;
878 #ifdef MAC
879 mac_ifnet_create_mbuf(ifp, m);
880 #endif
881
882 /* Could be unlocked read? */
883 mtx_lock(&tp->tun_mtx);
884 if (tp->tun_flags & TUN_IFHEAD) {
885 mtx_unlock(&tp->tun_mtx);
886 if (m->m_len < sizeof(family) &&
887 (m = m_pullup(m, sizeof(family))) == NULL)
888 return (ENOBUFS);
889 family = ntohl(*mtod(m, u_int32_t *));
890 m_adj(m, sizeof(family));
891 } else {
892 mtx_unlock(&tp->tun_mtx);
893 family = AF_INET;
894 }
895
896 BPF_MTAP2(ifp, &family, sizeof(family), m);
897
898 switch (family) {
899 #ifdef INET
900 case AF_INET:
901 isr = NETISR_IP;
902 break;
903 #endif
904 #ifdef INET6
905 case AF_INET6:
906 isr = NETISR_IPV6;
907 break;
908 #endif
909 default:
910 m_freem(m);
911 return (EAFNOSUPPORT);
912 }
913 random_harvest_queue(m, sizeof(*m), 2, RANDOM_NET_TUN);
914 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
915 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
916 CURVNET_SET(ifp->if_vnet);
917 M_SETFIB(m, ifp->if_fib);
918 netisr_dispatch(isr, m);
919 CURVNET_RESTORE();
920 return (0);
921 }
922
923 /*
924 * tunpoll - the poll interface, this is only useful on reads
925 * really. The write detect always returns true, write never blocks
926 * anyway, it either accepts the packet or drops it.
927 */
928 static int
929 tunpoll(struct cdev *dev, int events, struct thread *td)
930 {
931 struct tun_softc *tp = dev->si_drv1;
932 struct ifnet *ifp = TUN2IFP(tp);
933 int revents = 0;
934 struct mbuf *m;
935
936 TUNDEBUG(ifp, "tunpoll\n");
937
938 if (events & (POLLIN | POLLRDNORM)) {
939 IFQ_LOCK(&ifp->if_snd);
940 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
941 if (m != NULL) {
942 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len);
943 revents |= events & (POLLIN | POLLRDNORM);
944 } else {
945 TUNDEBUG(ifp, "tunpoll waiting\n");
946 selrecord(td, &tp->tun_rsel);
947 }
948 IFQ_UNLOCK(&ifp->if_snd);
949 }
950 if (events & (POLLOUT | POLLWRNORM))
951 revents |= events & (POLLOUT | POLLWRNORM);
952
953 return (revents);
954 }
955
956 /*
957 * tunkqfilter - support for the kevent() system call.
958 */
959 static int
960 tunkqfilter(struct cdev *dev, struct knote *kn)
961 {
962 struct tun_softc *tp = dev->si_drv1;
963 struct ifnet *ifp = TUN2IFP(tp);
964
965 switch(kn->kn_filter) {
966 case EVFILT_READ:
967 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n",
968 ifp->if_xname, dev2unit(dev));
969 kn->kn_fop = &tun_read_filterops;
970 break;
971
972 case EVFILT_WRITE:
973 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n",
974 ifp->if_xname, dev2unit(dev));
975 kn->kn_fop = &tun_write_filterops;
976 break;
977
978 default:
979 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n",
980 ifp->if_xname, dev2unit(dev));
981 return(EINVAL);
982 }
983
984 kn->kn_hook = tp;
985 knlist_add(&tp->tun_rsel.si_note, kn, 0);
986
987 return (0);
988 }
989
990 /*
991 * Return true of there is data in the interface queue.
992 */
993 static int
994 tunkqread(struct knote *kn, long hint)
995 {
996 int ret;
997 struct tun_softc *tp = kn->kn_hook;
998 struct cdev *dev = tp->tun_dev;
999 struct ifnet *ifp = TUN2IFP(tp);
1000
1001 if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) {
1002 TUNDEBUG(ifp,
1003 "%s have data in the queue. Len = %d, minor = %#x\n",
1004 ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev));
1005 ret = 1;
1006 } else {
1007 TUNDEBUG(ifp,
1008 "%s waiting for data, minor = %#x\n", ifp->if_xname,
1009 dev2unit(dev));
1010 ret = 0;
1011 }
1012
1013 return (ret);
1014 }
1015
1016 /*
1017 * Always can write, always return MTU in kn->data.
1018 */
1019 static int
1020 tunkqwrite(struct knote *kn, long hint)
1021 {
1022 struct tun_softc *tp = kn->kn_hook;
1023 struct ifnet *ifp = TUN2IFP(tp);
1024
1025 kn->kn_data = ifp->if_mtu;
1026
1027 return (1);
1028 }
1029
1030 static void
1031 tunkqdetach(struct knote *kn)
1032 {
1033 struct tun_softc *tp = kn->kn_hook;
1034
1035 knlist_remove(&tp->tun_rsel.si_note, kn, 0);
1036 }
Cache object: fdf7a5ff7aa44c91a30b4ee9a3dc9473
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