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/8.2/sys/net/if_tun.c 213726 2010-10-12 16:08:20Z jhb $
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 int 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", name,
232 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 knlist_destroy(&tp->tun_rsel.si_note);
263 mtx_destroy(&tp->tun_mtx);
264 cv_destroy(&tp->tun_cv);
265 free(tp, M_TUN);
266 CURVNET_RESTORE();
267 }
268
269 static void
270 tun_clone_destroy(struct ifnet *ifp)
271 {
272 struct tun_softc *tp = ifp->if_softc;
273
274 mtx_lock(&tunmtx);
275 TAILQ_REMOVE(&tunhead, tp, tun_list);
276 mtx_unlock(&tunmtx);
277 tun_destroy(tp);
278 }
279
280 static int
281 tunmodevent(module_t mod, int type, void *data)
282 {
283 static eventhandler_tag tag;
284 struct tun_softc *tp;
285
286 switch (type) {
287 case MOD_LOAD:
288 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF);
289 clone_setup(&tunclones);
290 tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000);
291 if (tag == NULL)
292 return (ENOMEM);
293 if_clone_attach(&tun_cloner);
294 break;
295 case MOD_UNLOAD:
296 if_clone_detach(&tun_cloner);
297 EVENTHANDLER_DEREGISTER(dev_clone, tag);
298 drain_dev_clone_events();
299
300 mtx_lock(&tunmtx);
301 while ((tp = TAILQ_FIRST(&tunhead)) != NULL) {
302 TAILQ_REMOVE(&tunhead, tp, tun_list);
303 mtx_unlock(&tunmtx);
304 tun_destroy(tp);
305 mtx_lock(&tunmtx);
306 }
307 mtx_unlock(&tunmtx);
308 clone_cleanup(&tunclones);
309 mtx_destroy(&tunmtx);
310 break;
311 default:
312 return EOPNOTSUPP;
313 }
314 return 0;
315 }
316
317 static moduledata_t tun_mod = {
318 "if_tun",
319 tunmodevent,
320 0
321 };
322
323 DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
324
325 static void
326 tunstart(struct ifnet *ifp)
327 {
328 struct tun_softc *tp = ifp->if_softc;
329 struct mbuf *m;
330
331 TUNDEBUG(ifp,"%s starting\n", ifp->if_xname);
332 if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
333 IFQ_LOCK(&ifp->if_snd);
334 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
335 if (m == NULL) {
336 IFQ_UNLOCK(&ifp->if_snd);
337 return;
338 }
339 IFQ_UNLOCK(&ifp->if_snd);
340 }
341
342 mtx_lock(&tp->tun_mtx);
343 if (tp->tun_flags & TUN_RWAIT) {
344 tp->tun_flags &= ~TUN_RWAIT;
345 wakeup(tp);
346 }
347 selwakeuppri(&tp->tun_rsel, PZERO + 1);
348 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
349 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) {
350 mtx_unlock(&tp->tun_mtx);
351 pgsigio(&tp->tun_sigio, SIGIO, 0);
352 } else
353 mtx_unlock(&tp->tun_mtx);
354 }
355
356 /* XXX: should return an error code so it can fail. */
357 static void
358 tuncreate(const char *name, struct cdev *dev)
359 {
360 struct tun_softc *sc;
361 struct ifnet *ifp;
362
363 dev->si_flags &= ~SI_CHEAPCLONE;
364
365 sc = malloc(sizeof(*sc), M_TUN, M_WAITOK | M_ZERO);
366 mtx_init(&sc->tun_mtx, "tun_mtx", NULL, MTX_DEF);
367 cv_init(&sc->tun_cv, "tun_condvar");
368 sc->tun_flags = TUN_INITED;
369 sc->tun_dev = dev;
370 mtx_lock(&tunmtx);
371 TAILQ_INSERT_TAIL(&tunhead, sc, tun_list);
372 mtx_unlock(&tunmtx);
373
374 ifp = sc->tun_ifp = if_alloc(IFT_PPP);
375 if (ifp == NULL)
376 panic("%s%d: failed to if_alloc() interface.\n",
377 name, dev2unit(dev));
378 if_initname(ifp, name, dev2unit(dev));
379 ifp->if_mtu = TUNMTU;
380 ifp->if_ioctl = tunifioctl;
381 ifp->if_output = tunoutput;
382 ifp->if_start = tunstart;
383 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
384 ifp->if_softc = sc;
385 IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
386 ifp->if_snd.ifq_drv_maxlen = 0;
387 IFQ_SET_READY(&ifp->if_snd);
388 knlist_init_mtx(&sc->tun_rsel.si_note, &sc->tun_mtx);
389 ifp->if_capabilities |= IFCAP_LINKSTATE;
390 ifp->if_capenable |= IFCAP_LINKSTATE;
391
392 if_attach(ifp);
393 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
394 dev->si_drv1 = sc;
395 TUNDEBUG(ifp, "interface %s is created, minor = %#x\n",
396 ifp->if_xname, dev2unit(dev));
397 }
398
399 static int
400 tunopen(struct cdev *dev, int flag, int mode, struct thread *td)
401 {
402 struct ifnet *ifp;
403 struct tun_softc *tp;
404
405 /*
406 * XXXRW: Non-atomic test and set of dev->si_drv1 requires
407 * synchronization.
408 */
409 tp = dev->si_drv1;
410 if (!tp) {
411 tuncreate(TUNNAME, dev);
412 tp = dev->si_drv1;
413 }
414
415 /*
416 * XXXRW: This use of tun_pid is subject to error due to the
417 * fact that a reference to the tunnel can live beyond the
418 * death of the process that created it. Can we replace this
419 * with a simple busy flag?
420 */
421 mtx_lock(&tp->tun_mtx);
422 if (tp->tun_pid != 0 && tp->tun_pid != td->td_proc->p_pid) {
423 mtx_unlock(&tp->tun_mtx);
424 return (EBUSY);
425 }
426 tp->tun_pid = td->td_proc->p_pid;
427
428 tp->tun_flags |= TUN_OPEN;
429 ifp = TUN2IFP(tp);
430 if_link_state_change(ifp, LINK_STATE_UP);
431 TUNDEBUG(ifp, "open\n");
432 mtx_unlock(&tp->tun_mtx);
433
434 return (0);
435 }
436
437 /*
438 * tunclose - close the device - mark i/f down & delete
439 * routing info
440 */
441 static int
442 tunclose(struct cdev *dev, int foo, int bar, struct thread *td)
443 {
444 struct tun_softc *tp;
445 struct ifnet *ifp;
446
447 tp = dev->si_drv1;
448 ifp = TUN2IFP(tp);
449
450 mtx_lock(&tp->tun_mtx);
451 tp->tun_flags &= ~TUN_OPEN;
452 tp->tun_pid = 0;
453
454 /*
455 * junk all pending output
456 */
457 CURVNET_SET(ifp->if_vnet);
458 IFQ_PURGE(&ifp->if_snd);
459
460 if (ifp->if_flags & IFF_UP) {
461 mtx_unlock(&tp->tun_mtx);
462 if_down(ifp);
463 mtx_lock(&tp->tun_mtx);
464 }
465
466 /* Delete all addresses and routes which reference this interface. */
467 if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
468 struct ifaddr *ifa;
469
470 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
471 mtx_unlock(&tp->tun_mtx);
472 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
473 /* deal w/IPv4 PtP destination; unlocked read */
474 if (ifa->ifa_addr->sa_family == AF_INET) {
475 rtinit(ifa, (int)RTM_DELETE,
476 tp->tun_flags & TUN_DSTADDR ? RTF_HOST : 0);
477 } else {
478 rtinit(ifa, (int)RTM_DELETE, 0);
479 }
480 }
481 if_purgeaddrs(ifp);
482 mtx_lock(&tp->tun_mtx);
483 }
484 if_link_state_change(ifp, LINK_STATE_DOWN);
485 CURVNET_RESTORE();
486
487 funsetown(&tp->tun_sigio);
488 selwakeuppri(&tp->tun_rsel, PZERO + 1);
489 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
490 TUNDEBUG (ifp, "closed\n");
491
492 cv_broadcast(&tp->tun_cv);
493 mtx_unlock(&tp->tun_mtx);
494 return (0);
495 }
496
497 static int
498 tuninit(struct ifnet *ifp)
499 {
500 struct tun_softc *tp = ifp->if_softc;
501 #ifdef INET
502 struct ifaddr *ifa;
503 #endif
504 int error = 0;
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 return (error);
532 }
533
534 /*
535 * Process an ioctl request.
536 */
537 static int
538 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
539 {
540 struct ifreq *ifr = (struct ifreq *)data;
541 struct tun_softc *tp = ifp->if_softc;
542 struct ifstat *ifs;
543 int error = 0;
544
545 switch(cmd) {
546 case SIOCGIFSTATUS:
547 ifs = (struct ifstat *)data;
548 mtx_lock(&tp->tun_mtx);
549 if (tp->tun_pid)
550 sprintf(ifs->ascii + strlen(ifs->ascii),
551 "\tOpened by PID %d\n", tp->tun_pid);
552 mtx_unlock(&tp->tun_mtx);
553 break;
554 case SIOCSIFADDR:
555 error = tuninit(ifp);
556 TUNDEBUG(ifp, "address set, error=%d\n", error);
557 break;
558 case SIOCSIFDSTADDR:
559 error = tuninit(ifp);
560 TUNDEBUG(ifp, "destination address set, error=%d\n", error);
561 break;
562 case SIOCSIFMTU:
563 ifp->if_mtu = ifr->ifr_mtu;
564 TUNDEBUG(ifp, "mtu set\n");
565 break;
566 case SIOCSIFFLAGS:
567 case SIOCADDMULTI:
568 case SIOCDELMULTI:
569 break;
570 default:
571 error = EINVAL;
572 }
573 return (error);
574 }
575
576 /*
577 * tunoutput - queue packets from higher level ready to put out.
578 */
579 static int
580 tunoutput(
581 struct ifnet *ifp,
582 struct mbuf *m0,
583 struct sockaddr *dst,
584 struct route *ro)
585 {
586 struct tun_softc *tp = ifp->if_softc;
587 u_short cached_tun_flags;
588 int error;
589 u_int32_t af;
590
591 TUNDEBUG (ifp, "tunoutput\n");
592
593 #ifdef MAC
594 error = mac_ifnet_check_transmit(ifp, m0);
595 if (error) {
596 m_freem(m0);
597 return (error);
598 }
599 #endif
600
601 /* Could be unlocked read? */
602 mtx_lock(&tp->tun_mtx);
603 cached_tun_flags = tp->tun_flags;
604 mtx_unlock(&tp->tun_mtx);
605 if ((cached_tun_flags & TUN_READY) != TUN_READY) {
606 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
607 m_freem (m0);
608 return (EHOSTDOWN);
609 }
610
611 if ((ifp->if_flags & IFF_UP) != IFF_UP) {
612 m_freem (m0);
613 return (EHOSTDOWN);
614 }
615
616 /* BPF writes need to be handled specially. */
617 if (dst->sa_family == AF_UNSPEC) {
618 bcopy(dst->sa_data, &af, sizeof(af));
619 dst->sa_family = af;
620 }
621
622 if (bpf_peers_present(ifp->if_bpf)) {
623 af = dst->sa_family;
624 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m0);
625 }
626
627 /* prepend sockaddr? this may abort if the mbuf allocation fails */
628 if (cached_tun_flags & TUN_LMODE) {
629 /* allocate space for sockaddr */
630 M_PREPEND(m0, dst->sa_len, M_DONTWAIT);
631
632 /* if allocation failed drop packet */
633 if (m0 == NULL) {
634 ifp->if_iqdrops++;
635 ifp->if_oerrors++;
636 return (ENOBUFS);
637 } else {
638 bcopy(dst, m0->m_data, dst->sa_len);
639 }
640 }
641
642 if (cached_tun_flags & TUN_IFHEAD) {
643 /* Prepend the address family */
644 M_PREPEND(m0, 4, M_DONTWAIT);
645
646 /* if allocation failed drop packet */
647 if (m0 == NULL) {
648 ifp->if_iqdrops++;
649 ifp->if_oerrors++;
650 return (ENOBUFS);
651 } else
652 *(u_int32_t *)m0->m_data = htonl(dst->sa_family);
653 } else {
654 #ifdef INET
655 if (dst->sa_family != AF_INET)
656 #endif
657 {
658 m_freem(m0);
659 return (EAFNOSUPPORT);
660 }
661 }
662
663 error = (ifp->if_transmit)(ifp, m0);
664 if (error) {
665 ifp->if_collisions++;
666 return (ENOBUFS);
667 }
668 ifp->if_opackets++;
669 return (0);
670 }
671
672 /*
673 * the cdevsw interface is now pretty minimal.
674 */
675 static int
676 tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
677 {
678 int error;
679 struct tun_softc *tp = dev->si_drv1;
680 struct tuninfo *tunp;
681
682 switch (cmd) {
683 case TUNSIFINFO:
684 tunp = (struct tuninfo *)data;
685 if (tunp->mtu < IF_MINMTU)
686 return (EINVAL);
687 if (TUN2IFP(tp)->if_mtu != tunp->mtu) {
688 error = priv_check(td, PRIV_NET_SETIFMTU);
689 if (error)
690 return (error);
691 }
692 mtx_lock(&tp->tun_mtx);
693 TUN2IFP(tp)->if_mtu = tunp->mtu;
694 TUN2IFP(tp)->if_type = tunp->type;
695 TUN2IFP(tp)->if_baudrate = tunp->baudrate;
696 mtx_unlock(&tp->tun_mtx);
697 break;
698 case TUNGIFINFO:
699 tunp = (struct tuninfo *)data;
700 mtx_lock(&tp->tun_mtx);
701 tunp->mtu = TUN2IFP(tp)->if_mtu;
702 tunp->type = TUN2IFP(tp)->if_type;
703 tunp->baudrate = TUN2IFP(tp)->if_baudrate;
704 mtx_unlock(&tp->tun_mtx);
705 break;
706 case TUNSDEBUG:
707 tundebug = *(int *)data;
708 break;
709 case TUNGDEBUG:
710 *(int *)data = tundebug;
711 break;
712 case TUNSLMODE:
713 mtx_lock(&tp->tun_mtx);
714 if (*(int *)data) {
715 tp->tun_flags |= TUN_LMODE;
716 tp->tun_flags &= ~TUN_IFHEAD;
717 } else
718 tp->tun_flags &= ~TUN_LMODE;
719 mtx_unlock(&tp->tun_mtx);
720 break;
721 case TUNSIFHEAD:
722 mtx_lock(&tp->tun_mtx);
723 if (*(int *)data) {
724 tp->tun_flags |= TUN_IFHEAD;
725 tp->tun_flags &= ~TUN_LMODE;
726 } else
727 tp->tun_flags &= ~TUN_IFHEAD;
728 mtx_unlock(&tp->tun_mtx);
729 break;
730 case TUNGIFHEAD:
731 mtx_lock(&tp->tun_mtx);
732 *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
733 mtx_unlock(&tp->tun_mtx);
734 break;
735 case TUNSIFMODE:
736 /* deny this if UP */
737 if (TUN2IFP(tp)->if_flags & IFF_UP)
738 return(EBUSY);
739
740 switch (*(int *)data & ~IFF_MULTICAST) {
741 case IFF_POINTOPOINT:
742 case IFF_BROADCAST:
743 mtx_lock(&tp->tun_mtx);
744 TUN2IFP(tp)->if_flags &=
745 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
746 TUN2IFP(tp)->if_flags |= *(int *)data;
747 mtx_unlock(&tp->tun_mtx);
748 break;
749 default:
750 return(EINVAL);
751 }
752 break;
753 case TUNSIFPID:
754 mtx_lock(&tp->tun_mtx);
755 tp->tun_pid = curthread->td_proc->p_pid;
756 mtx_unlock(&tp->tun_mtx);
757 break;
758 case FIONBIO:
759 break;
760 case FIOASYNC:
761 mtx_lock(&tp->tun_mtx);
762 if (*(int *)data)
763 tp->tun_flags |= TUN_ASYNC;
764 else
765 tp->tun_flags &= ~TUN_ASYNC;
766 mtx_unlock(&tp->tun_mtx);
767 break;
768 case FIONREAD:
769 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) {
770 struct mbuf *mb;
771 IFQ_LOCK(&TUN2IFP(tp)->if_snd);
772 IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb);
773 for (*(int *)data = 0; mb != NULL; mb = mb->m_next)
774 *(int *)data += mb->m_len;
775 IFQ_UNLOCK(&TUN2IFP(tp)->if_snd);
776 } else
777 *(int *)data = 0;
778 break;
779 case FIOSETOWN:
780 return (fsetown(*(int *)data, &tp->tun_sigio));
781
782 case FIOGETOWN:
783 *(int *)data = fgetown(&tp->tun_sigio);
784 return (0);
785
786 /* This is deprecated, FIOSETOWN should be used instead. */
787 case TIOCSPGRP:
788 return (fsetown(-(*(int *)data), &tp->tun_sigio));
789
790 /* This is deprecated, FIOGETOWN should be used instead. */
791 case TIOCGPGRP:
792 *(int *)data = -fgetown(&tp->tun_sigio);
793 return (0);
794
795 default:
796 return (ENOTTY);
797 }
798 return (0);
799 }
800
801 /*
802 * The cdevsw read interface - reads a packet at a time, or at
803 * least as much of a packet as can be read.
804 */
805 static int
806 tunread(struct cdev *dev, struct uio *uio, int flag)
807 {
808 struct tun_softc *tp = dev->si_drv1;
809 struct ifnet *ifp = TUN2IFP(tp);
810 struct mbuf *m;
811 int error=0, len;
812
813 TUNDEBUG (ifp, "read\n");
814 mtx_lock(&tp->tun_mtx);
815 if ((tp->tun_flags & TUN_READY) != TUN_READY) {
816 mtx_unlock(&tp->tun_mtx);
817 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
818 return (EHOSTDOWN);
819 }
820
821 tp->tun_flags &= ~TUN_RWAIT;
822
823 do {
824 IFQ_DEQUEUE(&ifp->if_snd, m);
825 if (m == NULL) {
826 if (flag & O_NONBLOCK) {
827 mtx_unlock(&tp->tun_mtx);
828 return (EWOULDBLOCK);
829 }
830 tp->tun_flags |= TUN_RWAIT;
831 error = mtx_sleep(tp, &tp->tun_mtx, PCATCH | (PZERO + 1),
832 "tunread", 0);
833 if (error != 0) {
834 mtx_unlock(&tp->tun_mtx);
835 return (error);
836 }
837 }
838 } while (m == NULL);
839 mtx_unlock(&tp->tun_mtx);
840
841 while (m && uio->uio_resid > 0 && error == 0) {
842 len = min(uio->uio_resid, m->m_len);
843 if (len != 0)
844 error = uiomove(mtod(m, void *), len, uio);
845 m = m_free(m);
846 }
847
848 if (m) {
849 TUNDEBUG(ifp, "Dropping mbuf\n");
850 m_freem(m);
851 }
852 return (error);
853 }
854
855 /*
856 * the cdevsw write interface - an atomic write is a packet - or else!
857 */
858 static int
859 tunwrite(struct cdev *dev, struct uio *uio, int flag)
860 {
861 struct tun_softc *tp = dev->si_drv1;
862 struct ifnet *ifp = TUN2IFP(tp);
863 struct mbuf *m;
864 int error = 0;
865 uint32_t family;
866 int isr;
867
868 TUNDEBUG(ifp, "tunwrite\n");
869
870 if ((ifp->if_flags & IFF_UP) != IFF_UP)
871 /* ignore silently */
872 return (0);
873
874 if (uio->uio_resid == 0)
875 return (0);
876
877 if (uio->uio_resid < 0 || uio->uio_resid > TUNMRU) {
878 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid);
879 return (EIO);
880 }
881
882 if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, 0, M_PKTHDR)) == NULL) {
883 ifp->if_ierrors++;
884 return (error);
885 }
886
887 m->m_pkthdr.rcvif = ifp;
888 #ifdef MAC
889 mac_ifnet_create_mbuf(ifp, m);
890 #endif
891
892 /* Could be unlocked read? */
893 mtx_lock(&tp->tun_mtx);
894 if (tp->tun_flags & TUN_IFHEAD) {
895 mtx_unlock(&tp->tun_mtx);
896 if (m->m_len < sizeof(family) &&
897 (m = m_pullup(m, sizeof(family))) == NULL)
898 return (ENOBUFS);
899 family = ntohl(*mtod(m, u_int32_t *));
900 m_adj(m, sizeof(family));
901 } else {
902 mtx_unlock(&tp->tun_mtx);
903 family = AF_INET;
904 }
905
906 BPF_MTAP2(ifp, &family, sizeof(family), m);
907
908 switch (family) {
909 #ifdef INET
910 case AF_INET:
911 isr = NETISR_IP;
912 break;
913 #endif
914 #ifdef INET6
915 case AF_INET6:
916 isr = NETISR_IPV6;
917 break;
918 #endif
919 #ifdef IPX
920 case AF_IPX:
921 isr = NETISR_IPX;
922 break;
923 #endif
924 #ifdef NETATALK
925 case AF_APPLETALK:
926 isr = NETISR_ATALK2;
927 break;
928 #endif
929 default:
930 m_freem(m);
931 return (EAFNOSUPPORT);
932 }
933 /* First chunk of an mbuf contains good junk */
934 if (harvest.point_to_point)
935 random_harvest(m, 16, 3, 0, RANDOM_NET);
936 ifp->if_ibytes += m->m_pkthdr.len;
937 ifp->if_ipackets++;
938 CURVNET_SET(ifp->if_vnet);
939 netisr_dispatch(isr, m);
940 CURVNET_RESTORE();
941 return (0);
942 }
943
944 /*
945 * tunpoll - the poll interface, this is only useful on reads
946 * really. The write detect always returns true, write never blocks
947 * anyway, it either accepts the packet or drops it.
948 */
949 static int
950 tunpoll(struct cdev *dev, int events, struct thread *td)
951 {
952 struct tun_softc *tp = dev->si_drv1;
953 struct ifnet *ifp = TUN2IFP(tp);
954 int revents = 0;
955 struct mbuf *m;
956
957 TUNDEBUG(ifp, "tunpoll\n");
958
959 if (events & (POLLIN | POLLRDNORM)) {
960 IFQ_LOCK(&ifp->if_snd);
961 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
962 if (m != NULL) {
963 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len);
964 revents |= events & (POLLIN | POLLRDNORM);
965 } else {
966 TUNDEBUG(ifp, "tunpoll waiting\n");
967 selrecord(td, &tp->tun_rsel);
968 }
969 IFQ_UNLOCK(&ifp->if_snd);
970 }
971 if (events & (POLLOUT | POLLWRNORM))
972 revents |= events & (POLLOUT | POLLWRNORM);
973
974 return (revents);
975 }
976
977 /*
978 * tunkqfilter - support for the kevent() system call.
979 */
980 static int
981 tunkqfilter(struct cdev *dev, struct knote *kn)
982 {
983 struct tun_softc *tp = dev->si_drv1;
984 struct ifnet *ifp = TUN2IFP(tp);
985
986 switch(kn->kn_filter) {
987 case EVFILT_READ:
988 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n",
989 ifp->if_xname, dev2unit(dev));
990 kn->kn_fop = &tun_read_filterops;
991 break;
992
993 case EVFILT_WRITE:
994 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n",
995 ifp->if_xname, dev2unit(dev));
996 kn->kn_fop = &tun_write_filterops;
997 break;
998
999 default:
1000 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n",
1001 ifp->if_xname, dev2unit(dev));
1002 return(EINVAL);
1003 }
1004
1005 kn->kn_hook = tp;
1006 knlist_add(&tp->tun_rsel.si_note, kn, 0);
1007
1008 return (0);
1009 }
1010
1011 /*
1012 * Return true of there is data in the interface queue.
1013 */
1014 static int
1015 tunkqread(struct knote *kn, long hint)
1016 {
1017 int ret;
1018 struct tun_softc *tp = kn->kn_hook;
1019 struct cdev *dev = tp->tun_dev;
1020 struct ifnet *ifp = TUN2IFP(tp);
1021
1022 if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) {
1023 TUNDEBUG(ifp,
1024 "%s have data in the queue. Len = %d, minor = %#x\n",
1025 ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev));
1026 ret = 1;
1027 } else {
1028 TUNDEBUG(ifp,
1029 "%s waiting for data, minor = %#x\n", ifp->if_xname,
1030 dev2unit(dev));
1031 ret = 0;
1032 }
1033
1034 return (ret);
1035 }
1036
1037 /*
1038 * Always can write, always return MTU in kn->data.
1039 */
1040 static int
1041 tunkqwrite(struct knote *kn, long hint)
1042 {
1043 struct tun_softc *tp = kn->kn_hook;
1044 struct ifnet *ifp = TUN2IFP(tp);
1045
1046 kn->kn_data = ifp->if_mtu;
1047
1048 return (1);
1049 }
1050
1051 static void
1052 tunkqdetach(struct knote *kn)
1053 {
1054 struct tun_softc *tp = kn->kn_hook;
1055
1056 knlist_remove(&tp->tun_rsel.si_note, kn, 0);
1057 }
Cache object: 7861790f75015a90d66a2a84b5ca0df6
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