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/9.0/sys/net/if_tun.c 225177 2011-08-25 15:51:54Z attilio $
17 */
18
19 #include "opt_atalk.h"
20 #include "opt_inet.h"
21 #include "opt_inet6.h"
22 #include "opt_ipx.h"
23
24 #include <sys/param.h>
25 #include <sys/priv.h>
26 #include <sys/proc.h>
27 #include <sys/systm.h>
28 #include <sys/jail.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 #include <net/vnet.h>
53 #ifdef INET
54 #include <netinet/in.h>
55 #endif
56 #include <net/bpf.h>
57 #include <net/if_tun.h>
58
59 #include <sys/queue.h>
60 #include <sys/condvar.h>
61
62 #include <security/mac/mac_framework.h>
63
64 /*
65 * tun_list is protected by global tunmtx. Other mutable fields are
66 * protected by tun->tun_mtx, or by their owning subsystem. tun_dev is
67 * static for the duration of a tunnel interface.
68 */
69 struct tun_softc {
70 TAILQ_ENTRY(tun_softc) tun_list;
71 struct cdev *tun_dev;
72 u_short tun_flags; /* misc flags */
73 #define TUN_OPEN 0x0001
74 #define TUN_INITED 0x0002
75 #define TUN_RCOLL 0x0004
76 #define TUN_IASET 0x0008
77 #define TUN_DSTADDR 0x0010
78 #define TUN_LMODE 0x0020
79 #define TUN_RWAIT 0x0040
80 #define TUN_ASYNC 0x0080
81 #define TUN_IFHEAD 0x0100
82
83 #define TUN_READY (TUN_OPEN | TUN_INITED)
84
85 /*
86 * XXXRW: tun_pid is used to exclusively lock /dev/tun. Is this
87 * actually needed? Can we just return EBUSY if already open?
88 * Problem is that this involved inherent races when a tun device
89 * is handed off from one process to another, as opposed to just
90 * being slightly stale informationally.
91 */
92 pid_t tun_pid; /* owning pid */
93 struct ifnet *tun_ifp; /* the interface */
94 struct sigio *tun_sigio; /* information for async I/O */
95 struct selinfo tun_rsel; /* read select */
96 struct mtx tun_mtx; /* protect mutable softc fields */
97 struct cv tun_cv; /* protect against ref'd dev destroy */
98 };
99 #define TUN2IFP(sc) ((sc)->tun_ifp)
100
101 #define TUNDEBUG if (tundebug) if_printf
102 #define TUNNAME "tun"
103
104 /*
105 * All mutable global variables in if_tun are locked using tunmtx, with
106 * the exception of tundebug, which is used unlocked, and tunclones,
107 * which is static after setup.
108 */
109 static struct mtx tunmtx;
110 static MALLOC_DEFINE(M_TUN, TUNNAME, "Tunnel Interface");
111 static int tundebug = 0;
112 static int tundclone = 1;
113 static struct clonedevs *tunclones;
114 static TAILQ_HEAD(,tun_softc) tunhead = TAILQ_HEAD_INITIALIZER(tunhead);
115 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");
116
117 SYSCTL_DECL(_net_link);
118 SYSCTL_NODE(_net_link, OID_AUTO, tun, CTLFLAG_RW, 0,
119 "IP tunnel software network interface.");
120 SYSCTL_INT(_net_link_tun, OID_AUTO, devfs_cloning, CTLFLAG_RW, &tundclone, 0,
121 "Enable legacy devfs interface creation.");
122
123 TUNABLE_INT("net.link.tun.devfs_cloning", &tundclone);
124
125 static void tunclone(void *arg, struct ucred *cred, char *name,
126 int namelen, struct cdev **dev);
127 static void tuncreate(const char *name, struct cdev *dev);
128 static int tunifioctl(struct ifnet *, u_long, caddr_t);
129 static void tuninit(struct ifnet *);
130 static int tunmodevent(module_t, int, void *);
131 static int tunoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
132 struct route *ro);
133 static void tunstart(struct ifnet *);
134
135 static int tun_clone_create(struct if_clone *, int, caddr_t);
136 static void tun_clone_destroy(struct ifnet *);
137
138 IFC_SIMPLE_DECLARE(tun, 0);
139
140 static d_open_t tunopen;
141 static d_close_t tunclose;
142 static d_read_t tunread;
143 static d_write_t tunwrite;
144 static d_ioctl_t tunioctl;
145 static d_poll_t tunpoll;
146 static d_kqfilter_t tunkqfilter;
147
148 static int tunkqread(struct knote *, long);
149 static int tunkqwrite(struct knote *, long);
150 static void tunkqdetach(struct knote *);
151
152 static struct filterops tun_read_filterops = {
153 .f_isfd = 1,
154 .f_attach = NULL,
155 .f_detach = tunkqdetach,
156 .f_event = tunkqread,
157 };
158
159 static struct filterops tun_write_filterops = {
160 .f_isfd = 1,
161 .f_attach = NULL,
162 .f_detach = tunkqdetach,
163 .f_event = tunkqwrite,
164 };
165
166 static struct cdevsw tun_cdevsw = {
167 .d_version = D_VERSION,
168 .d_flags = D_PSEUDO | D_NEEDMINOR,
169 .d_open = tunopen,
170 .d_close = tunclose,
171 .d_read = tunread,
172 .d_write = tunwrite,
173 .d_ioctl = tunioctl,
174 .d_poll = tunpoll,
175 .d_kqfilter = tunkqfilter,
176 .d_name = TUNNAME,
177 };
178
179 static int
180 tun_clone_create(struct if_clone *ifc, int unit, caddr_t params)
181 {
182 struct cdev *dev;
183 int i;
184
185 /* find any existing device, or allocate new unit number */
186 i = clone_create(&tunclones, &tun_cdevsw, &unit, &dev, 0);
187 if (i) {
188 /* No preexisting struct cdev *, create one */
189 dev = make_dev(&tun_cdevsw, unit,
190 UID_UUCP, GID_DIALER, 0600, "%s%d", ifc->ifc_name, unit);
191 }
192 tuncreate(ifc->ifc_name, dev);
193
194 return (0);
195 }
196
197 static void
198 tunclone(void *arg, struct ucred *cred, char *name, int namelen,
199 struct cdev **dev)
200 {
201 char devname[SPECNAMELEN + 1];
202 int u, i, append_unit;
203
204 if (*dev != NULL)
205 return;
206
207 /*
208 * If tun cloning is enabled, only the superuser can create an
209 * interface.
210 */
211 if (!tundclone || priv_check_cred(cred, PRIV_NET_IFCREATE, 0) != 0)
212 return;
213
214 if (strcmp(name, TUNNAME) == 0) {
215 u = -1;
216 } else if (dev_stdclone(name, NULL, TUNNAME, &u) != 1)
217 return; /* Don't recognise the name */
218 if (u != -1 && u > IF_MAXUNIT)
219 return; /* Unit number too high */
220
221 if (u == -1)
222 append_unit = 1;
223 else
224 append_unit = 0;
225
226 CURVNET_SET(CRED_TO_VNET(cred));
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",
232 name, u);
233 name = devname;
234 }
235 /* No preexisting struct cdev *, create one */
236 *dev = make_dev_credf(MAKEDEV_REF, &tun_cdevsw, u, cred,
237 UID_UUCP, GID_DIALER, 0600, "%s", name);
238 }
239
240 if_clone_create(name, namelen, NULL);
241 CURVNET_RESTORE();
242 }
243
244 static void
245 tun_destroy(struct tun_softc *tp)
246 {
247 struct cdev *dev;
248
249 /* Unlocked read. */
250 mtx_lock(&tp->tun_mtx);
251 if ((tp->tun_flags & TUN_OPEN) != 0)
252 cv_wait_unlock(&tp->tun_cv, &tp->tun_mtx);
253 else
254 mtx_unlock(&tp->tun_mtx);
255
256 CURVNET_SET(TUN2IFP(tp)->if_vnet);
257 dev = tp->tun_dev;
258 bpfdetach(TUN2IFP(tp));
259 if_detach(TUN2IFP(tp));
260 if_free(TUN2IFP(tp));
261 destroy_dev(dev);
262 seldrain(&tp->tun_rsel);
263 knlist_destroy(&tp->tun_rsel.si_note);
264 mtx_destroy(&tp->tun_mtx);
265 cv_destroy(&tp->tun_cv);
266 free(tp, M_TUN);
267 CURVNET_RESTORE();
268 }
269
270 static void
271 tun_clone_destroy(struct ifnet *ifp)
272 {
273 struct tun_softc *tp = ifp->if_softc;
274
275 mtx_lock(&tunmtx);
276 TAILQ_REMOVE(&tunhead, tp, tun_list);
277 mtx_unlock(&tunmtx);
278 tun_destroy(tp);
279 }
280
281 static int
282 tunmodevent(module_t mod, int type, void *data)
283 {
284 static eventhandler_tag tag;
285 struct tun_softc *tp;
286
287 switch (type) {
288 case MOD_LOAD:
289 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF);
290 clone_setup(&tunclones);
291 tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000);
292 if (tag == NULL)
293 return (ENOMEM);
294 if_clone_attach(&tun_cloner);
295 break;
296 case MOD_UNLOAD:
297 if_clone_detach(&tun_cloner);
298 EVENTHANDLER_DEREGISTER(dev_clone, tag);
299 drain_dev_clone_events();
300
301 mtx_lock(&tunmtx);
302 while ((tp = TAILQ_FIRST(&tunhead)) != NULL) {
303 TAILQ_REMOVE(&tunhead, tp, tun_list);
304 mtx_unlock(&tunmtx);
305 tun_destroy(tp);
306 mtx_lock(&tunmtx);
307 }
308 mtx_unlock(&tunmtx);
309 clone_cleanup(&tunclones);
310 mtx_destroy(&tunmtx);
311 break;
312 default:
313 return EOPNOTSUPP;
314 }
315 return 0;
316 }
317
318 static moduledata_t tun_mod = {
319 "if_tun",
320 tunmodevent,
321 0
322 };
323
324 DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
325
326 static void
327 tunstart(struct ifnet *ifp)
328 {
329 struct tun_softc *tp = ifp->if_softc;
330 struct mbuf *m;
331
332 TUNDEBUG(ifp,"%s starting\n", ifp->if_xname);
333 if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
334 IFQ_LOCK(&ifp->if_snd);
335 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
336 if (m == NULL) {
337 IFQ_UNLOCK(&ifp->if_snd);
338 return;
339 }
340 IFQ_UNLOCK(&ifp->if_snd);
341 }
342
343 mtx_lock(&tp->tun_mtx);
344 if (tp->tun_flags & TUN_RWAIT) {
345 tp->tun_flags &= ~TUN_RWAIT;
346 wakeup(tp);
347 }
348 selwakeuppri(&tp->tun_rsel, PZERO + 1);
349 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
350 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) {
351 mtx_unlock(&tp->tun_mtx);
352 pgsigio(&tp->tun_sigio, SIGIO, 0);
353 } else
354 mtx_unlock(&tp->tun_mtx);
355 }
356
357 /* XXX: should return an error code so it can fail. */
358 static void
359 tuncreate(const char *name, struct cdev *dev)
360 {
361 struct tun_softc *sc;
362 struct ifnet *ifp;
363
364 dev->si_flags &= ~SI_CHEAPCLONE;
365
366 sc = malloc(sizeof(*sc), M_TUN, M_WAITOK | M_ZERO);
367 mtx_init(&sc->tun_mtx, "tun_mtx", NULL, MTX_DEF);
368 cv_init(&sc->tun_cv, "tun_condvar");
369 sc->tun_flags = TUN_INITED;
370 sc->tun_dev = dev;
371 mtx_lock(&tunmtx);
372 TAILQ_INSERT_TAIL(&tunhead, sc, tun_list);
373 mtx_unlock(&tunmtx);
374
375 ifp = sc->tun_ifp = if_alloc(IFT_PPP);
376 if (ifp == NULL)
377 panic("%s%d: failed to if_alloc() interface.\n",
378 name, dev2unit(dev));
379 if_initname(ifp, name, dev2unit(dev));
380 ifp->if_mtu = TUNMTU;
381 ifp->if_ioctl = tunifioctl;
382 ifp->if_output = tunoutput;
383 ifp->if_start = tunstart;
384 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
385 ifp->if_softc = sc;
386 IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
387 ifp->if_snd.ifq_drv_maxlen = 0;
388 IFQ_SET_READY(&ifp->if_snd);
389 knlist_init_mtx(&sc->tun_rsel.si_note, &sc->tun_mtx);
390 ifp->if_capabilities |= IFCAP_LINKSTATE;
391 ifp->if_capenable |= IFCAP_LINKSTATE;
392
393 if_attach(ifp);
394 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
395 dev->si_drv1 = sc;
396 TUNDEBUG(ifp, "interface %s is created, minor = %#x\n",
397 ifp->if_xname, dev2unit(dev));
398 }
399
400 static int
401 tunopen(struct cdev *dev, int flag, int mode, struct thread *td)
402 {
403 struct ifnet *ifp;
404 struct tun_softc *tp;
405
406 /*
407 * XXXRW: Non-atomic test and set of dev->si_drv1 requires
408 * synchronization.
409 */
410 tp = dev->si_drv1;
411 if (!tp) {
412 tuncreate(TUNNAME, dev);
413 tp = dev->si_drv1;
414 }
415
416 /*
417 * XXXRW: This use of tun_pid is subject to error due to the
418 * fact that a reference to the tunnel can live beyond the
419 * death of the process that created it. Can we replace this
420 * with a simple busy flag?
421 */
422 mtx_lock(&tp->tun_mtx);
423 if (tp->tun_pid != 0 && tp->tun_pid != td->td_proc->p_pid) {
424 mtx_unlock(&tp->tun_mtx);
425 return (EBUSY);
426 }
427 tp->tun_pid = td->td_proc->p_pid;
428
429 tp->tun_flags |= TUN_OPEN;
430 ifp = TUN2IFP(tp);
431 if_link_state_change(ifp, LINK_STATE_UP);
432 TUNDEBUG(ifp, "open\n");
433 mtx_unlock(&tp->tun_mtx);
434
435 return (0);
436 }
437
438 /*
439 * tunclose - close the device - mark i/f down & delete
440 * routing info
441 */
442 static int
443 tunclose(struct cdev *dev, int foo, int bar, struct thread *td)
444 {
445 struct tun_softc *tp;
446 struct ifnet *ifp;
447
448 tp = dev->si_drv1;
449 ifp = TUN2IFP(tp);
450
451 mtx_lock(&tp->tun_mtx);
452 tp->tun_flags &= ~TUN_OPEN;
453 tp->tun_pid = 0;
454
455 /*
456 * junk all pending output
457 */
458 CURVNET_SET(ifp->if_vnet);
459 IFQ_PURGE(&ifp->if_snd);
460
461 if (ifp->if_flags & IFF_UP) {
462 mtx_unlock(&tp->tun_mtx);
463 if_down(ifp);
464 mtx_lock(&tp->tun_mtx);
465 }
466
467 /* Delete all addresses and routes which reference this interface. */
468 if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
469 struct ifaddr *ifa;
470
471 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
472 mtx_unlock(&tp->tun_mtx);
473 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
474 /* deal w/IPv4 PtP destination; unlocked read */
475 if (ifa->ifa_addr->sa_family == AF_INET) {
476 rtinit(ifa, (int)RTM_DELETE,
477 tp->tun_flags & TUN_DSTADDR ? RTF_HOST : 0);
478 } else {
479 rtinit(ifa, (int)RTM_DELETE, 0);
480 }
481 }
482 if_purgeaddrs(ifp);
483 mtx_lock(&tp->tun_mtx);
484 }
485 if_link_state_change(ifp, LINK_STATE_DOWN);
486 CURVNET_RESTORE();
487
488 funsetown(&tp->tun_sigio);
489 selwakeuppri(&tp->tun_rsel, PZERO + 1);
490 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
491 TUNDEBUG (ifp, "closed\n");
492
493 cv_broadcast(&tp->tun_cv);
494 mtx_unlock(&tp->tun_mtx);
495 return (0);
496 }
497
498 static void
499 tuninit(struct ifnet *ifp)
500 {
501 struct tun_softc *tp = ifp->if_softc;
502 #ifdef INET
503 struct ifaddr *ifa;
504 #endif
505
506 TUNDEBUG(ifp, "tuninit\n");
507
508 mtx_lock(&tp->tun_mtx);
509 ifp->if_flags |= IFF_UP;
510 ifp->if_drv_flags |= IFF_DRV_RUNNING;
511 getmicrotime(&ifp->if_lastchange);
512
513 #ifdef INET
514 if_addr_rlock(ifp);
515 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
516 if (ifa->ifa_addr->sa_family == AF_INET) {
517 struct sockaddr_in *si;
518
519 si = (struct sockaddr_in *)ifa->ifa_addr;
520 if (si->sin_addr.s_addr)
521 tp->tun_flags |= TUN_IASET;
522
523 si = (struct sockaddr_in *)ifa->ifa_dstaddr;
524 if (si && si->sin_addr.s_addr)
525 tp->tun_flags |= TUN_DSTADDR;
526 }
527 }
528 if_addr_runlock(ifp);
529 #endif
530 mtx_unlock(&tp->tun_mtx);
531 }
532
533 /*
534 * Process an ioctl request.
535 */
536 static int
537 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
538 {
539 struct ifreq *ifr = (struct ifreq *)data;
540 struct tun_softc *tp = ifp->if_softc;
541 struct ifstat *ifs;
542 int error = 0;
543
544 switch(cmd) {
545 case SIOCGIFSTATUS:
546 ifs = (struct ifstat *)data;
547 mtx_lock(&tp->tun_mtx);
548 if (tp->tun_pid)
549 sprintf(ifs->ascii + strlen(ifs->ascii),
550 "\tOpened by PID %d\n", tp->tun_pid);
551 mtx_unlock(&tp->tun_mtx);
552 break;
553 case SIOCSIFADDR:
554 tuninit(ifp);
555 TUNDEBUG(ifp, "address set\n");
556 break;
557 case SIOCSIFDSTADDR:
558 tuninit(ifp);
559 TUNDEBUG(ifp, "destination address set\n");
560 break;
561 case SIOCSIFMTU:
562 ifp->if_mtu = ifr->ifr_mtu;
563 TUNDEBUG(ifp, "mtu set\n");
564 break;
565 case SIOCSIFFLAGS:
566 case SIOCADDMULTI:
567 case SIOCDELMULTI:
568 break;
569 default:
570 error = EINVAL;
571 }
572 return (error);
573 }
574
575 /*
576 * tunoutput - queue packets from higher level ready to put out.
577 */
578 static int
579 tunoutput(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst,
580 struct route *ro)
581 {
582 struct tun_softc *tp = ifp->if_softc;
583 u_short cached_tun_flags;
584 int error;
585 u_int32_t af;
586
587 TUNDEBUG (ifp, "tunoutput\n");
588
589 #ifdef MAC
590 error = mac_ifnet_check_transmit(ifp, m0);
591 if (error) {
592 m_freem(m0);
593 return (error);
594 }
595 #endif
596
597 /* Could be unlocked read? */
598 mtx_lock(&tp->tun_mtx);
599 cached_tun_flags = tp->tun_flags;
600 mtx_unlock(&tp->tun_mtx);
601 if ((cached_tun_flags & TUN_READY) != TUN_READY) {
602 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
603 m_freem (m0);
604 return (EHOSTDOWN);
605 }
606
607 if ((ifp->if_flags & IFF_UP) != IFF_UP) {
608 m_freem (m0);
609 return (EHOSTDOWN);
610 }
611
612 /* BPF writes need to be handled specially. */
613 if (dst->sa_family == AF_UNSPEC) {
614 bcopy(dst->sa_data, &af, sizeof(af));
615 dst->sa_family = af;
616 }
617
618 if (bpf_peers_present(ifp->if_bpf)) {
619 af = dst->sa_family;
620 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m0);
621 }
622
623 /* prepend sockaddr? this may abort if the mbuf allocation fails */
624 if (cached_tun_flags & TUN_LMODE) {
625 /* allocate space for sockaddr */
626 M_PREPEND(m0, dst->sa_len, M_DONTWAIT);
627
628 /* if allocation failed drop packet */
629 if (m0 == NULL) {
630 ifp->if_iqdrops++;
631 ifp->if_oerrors++;
632 return (ENOBUFS);
633 } else {
634 bcopy(dst, m0->m_data, dst->sa_len);
635 }
636 }
637
638 if (cached_tun_flags & TUN_IFHEAD) {
639 /* Prepend the address family */
640 M_PREPEND(m0, 4, M_DONTWAIT);
641
642 /* if allocation failed drop packet */
643 if (m0 == NULL) {
644 ifp->if_iqdrops++;
645 ifp->if_oerrors++;
646 return (ENOBUFS);
647 } else
648 *(u_int32_t *)m0->m_data = htonl(dst->sa_family);
649 } else {
650 #ifdef INET
651 if (dst->sa_family != AF_INET)
652 #endif
653 {
654 m_freem(m0);
655 return (EAFNOSUPPORT);
656 }
657 }
658
659 error = (ifp->if_transmit)(ifp, m0);
660 if (error)
661 return (ENOBUFS);
662 ifp->if_opackets++;
663 return (0);
664 }
665
666 /*
667 * the cdevsw interface is now pretty minimal.
668 */
669 static int
670 tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag,
671 struct thread *td)
672 {
673 int error;
674 struct tun_softc *tp = dev->si_drv1;
675 struct tuninfo *tunp;
676
677 switch (cmd) {
678 case TUNSIFINFO:
679 tunp = (struct tuninfo *)data;
680 if (tunp->mtu < IF_MINMTU)
681 return (EINVAL);
682 if (TUN2IFP(tp)->if_mtu != tunp->mtu) {
683 error = priv_check(td, PRIV_NET_SETIFMTU);
684 if (error)
685 return (error);
686 }
687 mtx_lock(&tp->tun_mtx);
688 TUN2IFP(tp)->if_mtu = tunp->mtu;
689 TUN2IFP(tp)->if_type = tunp->type;
690 TUN2IFP(tp)->if_baudrate = tunp->baudrate;
691 mtx_unlock(&tp->tun_mtx);
692 break;
693 case TUNGIFINFO:
694 tunp = (struct tuninfo *)data;
695 mtx_lock(&tp->tun_mtx);
696 tunp->mtu = TUN2IFP(tp)->if_mtu;
697 tunp->type = TUN2IFP(tp)->if_type;
698 tunp->baudrate = TUN2IFP(tp)->if_baudrate;
699 mtx_unlock(&tp->tun_mtx);
700 break;
701 case TUNSDEBUG:
702 tundebug = *(int *)data;
703 break;
704 case TUNGDEBUG:
705 *(int *)data = tundebug;
706 break;
707 case TUNSLMODE:
708 mtx_lock(&tp->tun_mtx);
709 if (*(int *)data) {
710 tp->tun_flags |= TUN_LMODE;
711 tp->tun_flags &= ~TUN_IFHEAD;
712 } else
713 tp->tun_flags &= ~TUN_LMODE;
714 mtx_unlock(&tp->tun_mtx);
715 break;
716 case TUNSIFHEAD:
717 mtx_lock(&tp->tun_mtx);
718 if (*(int *)data) {
719 tp->tun_flags |= TUN_IFHEAD;
720 tp->tun_flags &= ~TUN_LMODE;
721 } else
722 tp->tun_flags &= ~TUN_IFHEAD;
723 mtx_unlock(&tp->tun_mtx);
724 break;
725 case TUNGIFHEAD:
726 mtx_lock(&tp->tun_mtx);
727 *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
728 mtx_unlock(&tp->tun_mtx);
729 break;
730 case TUNSIFMODE:
731 /* deny this if UP */
732 if (TUN2IFP(tp)->if_flags & IFF_UP)
733 return(EBUSY);
734
735 switch (*(int *)data & ~IFF_MULTICAST) {
736 case IFF_POINTOPOINT:
737 case IFF_BROADCAST:
738 mtx_lock(&tp->tun_mtx);
739 TUN2IFP(tp)->if_flags &=
740 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
741 TUN2IFP(tp)->if_flags |= *(int *)data;
742 mtx_unlock(&tp->tun_mtx);
743 break;
744 default:
745 return(EINVAL);
746 }
747 break;
748 case TUNSIFPID:
749 mtx_lock(&tp->tun_mtx);
750 tp->tun_pid = curthread->td_proc->p_pid;
751 mtx_unlock(&tp->tun_mtx);
752 break;
753 case FIONBIO:
754 break;
755 case FIOASYNC:
756 mtx_lock(&tp->tun_mtx);
757 if (*(int *)data)
758 tp->tun_flags |= TUN_ASYNC;
759 else
760 tp->tun_flags &= ~TUN_ASYNC;
761 mtx_unlock(&tp->tun_mtx);
762 break;
763 case FIONREAD:
764 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) {
765 struct mbuf *mb;
766 IFQ_LOCK(&TUN2IFP(tp)->if_snd);
767 IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb);
768 for (*(int *)data = 0; mb != NULL; mb = mb->m_next)
769 *(int *)data += mb->m_len;
770 IFQ_UNLOCK(&TUN2IFP(tp)->if_snd);
771 } else
772 *(int *)data = 0;
773 break;
774 case FIOSETOWN:
775 return (fsetown(*(int *)data, &tp->tun_sigio));
776
777 case FIOGETOWN:
778 *(int *)data = fgetown(&tp->tun_sigio);
779 return (0);
780
781 /* This is deprecated, FIOSETOWN should be used instead. */
782 case TIOCSPGRP:
783 return (fsetown(-(*(int *)data), &tp->tun_sigio));
784
785 /* This is deprecated, FIOGETOWN should be used instead. */
786 case TIOCGPGRP:
787 *(int *)data = -fgetown(&tp->tun_sigio);
788 return (0);
789
790 default:
791 return (ENOTTY);
792 }
793 return (0);
794 }
795
796 /*
797 * The cdevsw read interface - reads a packet at a time, or at
798 * least as much of a packet as can be read.
799 */
800 static int
801 tunread(struct cdev *dev, struct uio *uio, int flag)
802 {
803 struct tun_softc *tp = dev->si_drv1;
804 struct ifnet *ifp = TUN2IFP(tp);
805 struct mbuf *m;
806 int error=0, len;
807
808 TUNDEBUG (ifp, "read\n");
809 mtx_lock(&tp->tun_mtx);
810 if ((tp->tun_flags & TUN_READY) != TUN_READY) {
811 mtx_unlock(&tp->tun_mtx);
812 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
813 return (EHOSTDOWN);
814 }
815
816 tp->tun_flags &= ~TUN_RWAIT;
817
818 do {
819 IFQ_DEQUEUE(&ifp->if_snd, m);
820 if (m == NULL) {
821 if (flag & O_NONBLOCK) {
822 mtx_unlock(&tp->tun_mtx);
823 return (EWOULDBLOCK);
824 }
825 tp->tun_flags |= TUN_RWAIT;
826 error = mtx_sleep(tp, &tp->tun_mtx, PCATCH | (PZERO + 1),
827 "tunread", 0);
828 if (error != 0) {
829 mtx_unlock(&tp->tun_mtx);
830 return (error);
831 }
832 }
833 } while (m == NULL);
834 mtx_unlock(&tp->tun_mtx);
835
836 while (m && uio->uio_resid > 0 && error == 0) {
837 len = min(uio->uio_resid, m->m_len);
838 if (len != 0)
839 error = uiomove(mtod(m, void *), len, uio);
840 m = m_free(m);
841 }
842
843 if (m) {
844 TUNDEBUG(ifp, "Dropping mbuf\n");
845 m_freem(m);
846 }
847 return (error);
848 }
849
850 /*
851 * the cdevsw write interface - an atomic write is a packet - or else!
852 */
853 static int
854 tunwrite(struct cdev *dev, struct uio *uio, int flag)
855 {
856 struct tun_softc *tp = dev->si_drv1;
857 struct ifnet *ifp = TUN2IFP(tp);
858 struct mbuf *m;
859 uint32_t family;
860 int isr;
861
862 TUNDEBUG(ifp, "tunwrite\n");
863
864 if ((ifp->if_flags & IFF_UP) != IFF_UP)
865 /* ignore silently */
866 return (0);
867
868 if (uio->uio_resid == 0)
869 return (0);
870
871 if (uio->uio_resid < 0 || uio->uio_resid > TUNMRU) {
872 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid);
873 return (EIO);
874 }
875
876 if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, 0, M_PKTHDR)) == NULL) {
877 ifp->if_ierrors++;
878 return (ENOBUFS);
879 }
880
881 m->m_pkthdr.rcvif = ifp;
882 #ifdef MAC
883 mac_ifnet_create_mbuf(ifp, m);
884 #endif
885
886 /* Could be unlocked read? */
887 mtx_lock(&tp->tun_mtx);
888 if (tp->tun_flags & TUN_IFHEAD) {
889 mtx_unlock(&tp->tun_mtx);
890 if (m->m_len < sizeof(family) &&
891 (m = m_pullup(m, sizeof(family))) == NULL)
892 return (ENOBUFS);
893 family = ntohl(*mtod(m, u_int32_t *));
894 m_adj(m, sizeof(family));
895 } else {
896 mtx_unlock(&tp->tun_mtx);
897 family = AF_INET;
898 }
899
900 BPF_MTAP2(ifp, &family, sizeof(family), m);
901
902 switch (family) {
903 #ifdef INET
904 case AF_INET:
905 isr = NETISR_IP;
906 break;
907 #endif
908 #ifdef INET6
909 case AF_INET6:
910 isr = NETISR_IPV6;
911 break;
912 #endif
913 #ifdef IPX
914 case AF_IPX:
915 isr = NETISR_IPX;
916 break;
917 #endif
918 #ifdef NETATALK
919 case AF_APPLETALK:
920 isr = NETISR_ATALK2;
921 break;
922 #endif
923 default:
924 m_freem(m);
925 return (EAFNOSUPPORT);
926 }
927 /* First chunk of an mbuf contains good junk */
928 if (harvest.point_to_point)
929 random_harvest(m, 16, 3, 0, RANDOM_NET);
930 ifp->if_ibytes += m->m_pkthdr.len;
931 ifp->if_ipackets++;
932 CURVNET_SET(ifp->if_vnet);
933 M_SETFIB(m, ifp->if_fib);
934 netisr_dispatch(isr, m);
935 CURVNET_RESTORE();
936 return (0);
937 }
938
939 /*
940 * tunpoll - the poll interface, this is only useful on reads
941 * really. The write detect always returns true, write never blocks
942 * anyway, it either accepts the packet or drops it.
943 */
944 static int
945 tunpoll(struct cdev *dev, int events, struct thread *td)
946 {
947 struct tun_softc *tp = dev->si_drv1;
948 struct ifnet *ifp = TUN2IFP(tp);
949 int revents = 0;
950 struct mbuf *m;
951
952 TUNDEBUG(ifp, "tunpoll\n");
953
954 if (events & (POLLIN | POLLRDNORM)) {
955 IFQ_LOCK(&ifp->if_snd);
956 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
957 if (m != NULL) {
958 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len);
959 revents |= events & (POLLIN | POLLRDNORM);
960 } else {
961 TUNDEBUG(ifp, "tunpoll waiting\n");
962 selrecord(td, &tp->tun_rsel);
963 }
964 IFQ_UNLOCK(&ifp->if_snd);
965 }
966 if (events & (POLLOUT | POLLWRNORM))
967 revents |= events & (POLLOUT | POLLWRNORM);
968
969 return (revents);
970 }
971
972 /*
973 * tunkqfilter - support for the kevent() system call.
974 */
975 static int
976 tunkqfilter(struct cdev *dev, struct knote *kn)
977 {
978 struct tun_softc *tp = dev->si_drv1;
979 struct ifnet *ifp = TUN2IFP(tp);
980
981 switch(kn->kn_filter) {
982 case EVFILT_READ:
983 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n",
984 ifp->if_xname, dev2unit(dev));
985 kn->kn_fop = &tun_read_filterops;
986 break;
987
988 case EVFILT_WRITE:
989 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n",
990 ifp->if_xname, dev2unit(dev));
991 kn->kn_fop = &tun_write_filterops;
992 break;
993
994 default:
995 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n",
996 ifp->if_xname, dev2unit(dev));
997 return(EINVAL);
998 }
999
1000 kn->kn_hook = tp;
1001 knlist_add(&tp->tun_rsel.si_note, kn, 0);
1002
1003 return (0);
1004 }
1005
1006 /*
1007 * Return true of there is data in the interface queue.
1008 */
1009 static int
1010 tunkqread(struct knote *kn, long hint)
1011 {
1012 int ret;
1013 struct tun_softc *tp = kn->kn_hook;
1014 struct cdev *dev = tp->tun_dev;
1015 struct ifnet *ifp = TUN2IFP(tp);
1016
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, dev2unit(dev));
1021 ret = 1;
1022 } else {
1023 TUNDEBUG(ifp,
1024 "%s waiting for data, minor = %#x\n", ifp->if_xname,
1025 dev2unit(dev));
1026 ret = 0;
1027 }
1028
1029 return (ret);
1030 }
1031
1032 /*
1033 * Always can write, always return MTU in kn->data.
1034 */
1035 static int
1036 tunkqwrite(struct knote *kn, long hint)
1037 {
1038 struct tun_softc *tp = kn->kn_hook;
1039 struct ifnet *ifp = TUN2IFP(tp);
1040
1041 kn->kn_data = ifp->if_mtu;
1042
1043 return (1);
1044 }
1045
1046 static void
1047 tunkqdetach(struct knote *kn)
1048 {
1049 struct tun_softc *tp = kn->kn_hook;
1050
1051 knlist_remove(&tp->tun_rsel.si_note, kn, 0);
1052 }
Cache object: 632e6b28ac79c9d95796ea735b0cbd49
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