1 /* $NetBSD: if_tun.c,v 1.14 1994/06/29 06:36:25 cgd Exp $ */
2 /*-
3 * SPDX-License-Identifier: BSD-2-Clause
4 *
5 * Copyright (C) 1999-2000 by Maksim Yevmenkin <m_evmenkin@yahoo.com>
6 * All rights reserved.
7 * Copyright (c) 2019 Kyle Evans <kevans@FreeBSD.org>
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * BASED ON:
32 * -------------------------------------------------------------------------
33 *
34 * Copyright (c) 1988, Julian Onions <jpo@cs.nott.ac.uk>
35 * Nottingham University 1987.
36 *
37 * This source may be freely distributed, however I would be interested
38 * in any changes that are made.
39 *
40 * This driver takes packets off the IP i/f and hands them up to a
41 * user process to have its wicked way with. This driver has it's
42 * roots in a similar driver written by Phil Cockcroft (formerly) at
43 * UCL. This driver is based much more on read/write/poll mode of
44 * operation though.
45 */
46
47 #include "opt_inet.h"
48 #include "opt_inet6.h"
49
50 #include <sys/param.h>
51 #include <sys/lock.h>
52 #include <sys/priv.h>
53 #include <sys/proc.h>
54 #include <sys/systm.h>
55 #include <sys/jail.h>
56 #include <sys/mbuf.h>
57 #include <sys/module.h>
58 #include <sys/socket.h>
59 #include <sys/eventhandler.h>
60 #include <sys/fcntl.h>
61 #include <sys/filio.h>
62 #include <sys/sockio.h>
63 #include <sys/sx.h>
64 #include <sys/syslog.h>
65 #include <sys/ttycom.h>
66 #include <sys/poll.h>
67 #include <sys/selinfo.h>
68 #include <sys/signalvar.h>
69 #include <sys/filedesc.h>
70 #include <sys/kernel.h>
71 #include <sys/sysctl.h>
72 #include <sys/conf.h>
73 #include <sys/uio.h>
74 #include <sys/malloc.h>
75 #include <sys/random.h>
76 #include <sys/ctype.h>
77
78 #include <net/ethernet.h>
79 #include <net/if.h>
80 #include <net/if_var.h>
81 #include <net/if_clone.h>
82 #include <net/if_dl.h>
83 #include <net/if_media.h>
84 #include <net/if_private.h>
85 #include <net/if_types.h>
86 #include <net/if_vlan_var.h>
87 #include <net/netisr.h>
88 #include <net/route.h>
89 #include <net/vnet.h>
90 #include <netinet/in.h>
91 #ifdef INET
92 #include <netinet/ip.h>
93 #endif
94 #ifdef INET6
95 #include <netinet/ip6.h>
96 #include <netinet6/ip6_var.h>
97 #endif
98 #include <netinet/udp.h>
99 #include <netinet/tcp.h>
100 #include <netinet/tcp_lro.h>
101 #include <net/bpf.h>
102 #include <net/if_tap.h>
103 #include <net/if_tun.h>
104
105 #include <dev/virtio/network/virtio_net.h>
106
107 #include <sys/queue.h>
108 #include <sys/condvar.h>
109 #include <security/mac/mac_framework.h>
110
111 struct tuntap_driver;
112
113 /*
114 * tun_list is protected by global tunmtx. Other mutable fields are
115 * protected by tun->tun_mtx, or by their owning subsystem. tun_dev is
116 * static for the duration of a tunnel interface.
117 */
118 struct tuntap_softc {
119 TAILQ_ENTRY(tuntap_softc) tun_list;
120 struct cdev *tun_alias;
121 struct cdev *tun_dev;
122 u_short tun_flags; /* misc flags */
123 #define TUN_OPEN 0x0001
124 #define TUN_INITED 0x0002
125 #define TUN_UNUSED1 0x0008
126 #define TUN_UNUSED2 0x0010
127 #define TUN_LMODE 0x0020
128 #define TUN_RWAIT 0x0040
129 #define TUN_ASYNC 0x0080
130 #define TUN_IFHEAD 0x0100
131 #define TUN_DYING 0x0200
132 #define TUN_L2 0x0400
133 #define TUN_VMNET 0x0800
134
135 #define TUN_DRIVER_IDENT_MASK (TUN_L2 | TUN_VMNET)
136 #define TUN_READY (TUN_OPEN | TUN_INITED)
137
138 pid_t tun_pid; /* owning pid */
139 struct ifnet *tun_ifp; /* the interface */
140 struct sigio *tun_sigio; /* async I/O info */
141 struct tuntap_driver *tun_drv; /* appropriate driver */
142 struct selinfo tun_rsel; /* read select */
143 struct mtx tun_mtx; /* softc field mutex */
144 struct cv tun_cv; /* for ref'd dev destroy */
145 struct ether_addr tun_ether; /* remote address */
146 int tun_busy; /* busy count */
147 int tun_vhdrlen; /* virtio-net header length */
148 struct lro_ctrl tun_lro; /* for TCP LRO */
149 bool tun_lro_ready; /* TCP LRO initialized */
150 };
151 #define TUN2IFP(sc) ((sc)->tun_ifp)
152
153 #define TUNDEBUG if (tundebug) if_printf
154
155 #define TUN_LOCK(tp) mtx_lock(&(tp)->tun_mtx)
156 #define TUN_UNLOCK(tp) mtx_unlock(&(tp)->tun_mtx)
157 #define TUN_LOCK_ASSERT(tp) mtx_assert(&(tp)->tun_mtx, MA_OWNED);
158
159 #define TUN_VMIO_FLAG_MASK 0x0fff
160
161 /*
162 * Interface capabilities of a tap device that supports the virtio-net
163 * header.
164 */
165 #define TAP_VNET_HDR_CAPS (IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6 \
166 | IFCAP_VLAN_HWCSUM \
167 | IFCAP_TSO | IFCAP_LRO \
168 | IFCAP_VLAN_HWTSO)
169
170 #define TAP_ALL_OFFLOAD (CSUM_TSO | CSUM_TCP | CSUM_UDP |\
171 CSUM_TCP_IPV6 | CSUM_UDP_IPV6)
172
173 /*
174 * All mutable global variables in if_tun are locked using tunmtx, with
175 * the exception of tundebug, which is used unlocked, and the drivers' *clones,
176 * which are static after setup.
177 */
178 static struct mtx tunmtx;
179 static eventhandler_tag arrival_tag;
180 static eventhandler_tag clone_tag;
181 static const char tunname[] = "tun";
182 static const char tapname[] = "tap";
183 static const char vmnetname[] = "vmnet";
184 static MALLOC_DEFINE(M_TUN, tunname, "Tunnel Interface");
185 static int tundebug = 0;
186 static int tundclone = 1;
187 static int tap_allow_uopen = 0; /* allow user devfs cloning */
188 static int tapuponopen = 0; /* IFF_UP on open() */
189 static int tapdclone = 1; /* enable devfs cloning */
190
191 static TAILQ_HEAD(,tuntap_softc) tunhead = TAILQ_HEAD_INITIALIZER(tunhead);
192 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");
193
194 static struct sx tun_ioctl_sx;
195 SX_SYSINIT(tun_ioctl_sx, &tun_ioctl_sx, "tun_ioctl");
196
197 SYSCTL_DECL(_net_link);
198 /* tun */
199 static SYSCTL_NODE(_net_link, OID_AUTO, tun, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
200 "IP tunnel software network interface");
201 SYSCTL_INT(_net_link_tun, OID_AUTO, devfs_cloning, CTLFLAG_RWTUN, &tundclone, 0,
202 "Enable legacy devfs interface creation");
203
204 /* tap */
205 static SYSCTL_NODE(_net_link, OID_AUTO, tap, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
206 "Ethernet tunnel software network interface");
207 SYSCTL_INT(_net_link_tap, OID_AUTO, user_open, CTLFLAG_RW, &tap_allow_uopen, 0,
208 "Enable legacy devfs interface creation for all users");
209 SYSCTL_INT(_net_link_tap, OID_AUTO, up_on_open, CTLFLAG_RW, &tapuponopen, 0,
210 "Bring interface up when /dev/tap is opened");
211 SYSCTL_INT(_net_link_tap, OID_AUTO, devfs_cloning, CTLFLAG_RWTUN, &tapdclone, 0,
212 "Enable legacy devfs interface creation");
213 SYSCTL_INT(_net_link_tap, OID_AUTO, debug, CTLFLAG_RW, &tundebug, 0, "");
214
215 static int tun_create_device(struct tuntap_driver *drv, int unit,
216 struct ucred *cr, struct cdev **dev, const char *name);
217 static int tun_busy_locked(struct tuntap_softc *tp);
218 static void tun_unbusy_locked(struct tuntap_softc *tp);
219 static int tun_busy(struct tuntap_softc *tp);
220 static void tun_unbusy(struct tuntap_softc *tp);
221
222 static int tuntap_name2info(const char *name, int *unit, int *flags);
223 static void tunclone(void *arg, struct ucred *cred, char *name,
224 int namelen, struct cdev **dev);
225 static void tuncreate(struct cdev *dev);
226 static void tundtor(void *data);
227 static void tunrename(void *arg, struct ifnet *ifp);
228 static int tunifioctl(struct ifnet *, u_long, caddr_t);
229 static void tuninit(struct ifnet *);
230 static void tunifinit(void *xtp);
231 static int tuntapmodevent(module_t, int, void *);
232 static int tunoutput(struct ifnet *, struct mbuf *,
233 const struct sockaddr *, struct route *ro);
234 static void tunstart(struct ifnet *);
235 static void tunstart_l2(struct ifnet *);
236
237 static int tun_clone_match(struct if_clone *ifc, const char *name);
238 static int tap_clone_match(struct if_clone *ifc, const char *name);
239 static int vmnet_clone_match(struct if_clone *ifc, const char *name);
240 static int tun_clone_create(struct if_clone *, char *, size_t,
241 struct ifc_data *, struct ifnet **);
242 static int tun_clone_destroy(struct if_clone *, struct ifnet *, uint32_t);
243 static void tun_vnethdr_set(struct ifnet *ifp, int vhdrlen);
244
245 static d_open_t tunopen;
246 static d_read_t tunread;
247 static d_write_t tunwrite;
248 static d_ioctl_t tunioctl;
249 static d_poll_t tunpoll;
250 static d_kqfilter_t tunkqfilter;
251
252 static int tunkqread(struct knote *, long);
253 static int tunkqwrite(struct knote *, long);
254 static void tunkqdetach(struct knote *);
255
256 static const struct filterops tun_read_filterops = {
257 .f_isfd = 1,
258 .f_attach = NULL,
259 .f_detach = tunkqdetach,
260 .f_event = tunkqread,
261 };
262
263 static const struct filterops tun_write_filterops = {
264 .f_isfd = 1,
265 .f_attach = NULL,
266 .f_detach = tunkqdetach,
267 .f_event = tunkqwrite,
268 };
269
270 static struct tuntap_driver {
271 struct cdevsw cdevsw;
272 int ident_flags;
273 struct unrhdr *unrhdr;
274 struct clonedevs *clones;
275 ifc_match_f *clone_match_fn;
276 ifc_create_f *clone_create_fn;
277 ifc_destroy_f *clone_destroy_fn;
278 } tuntap_drivers[] = {
279 {
280 .ident_flags = 0,
281 .cdevsw = {
282 .d_version = D_VERSION,
283 .d_flags = D_NEEDMINOR,
284 .d_open = tunopen,
285 .d_read = tunread,
286 .d_write = tunwrite,
287 .d_ioctl = tunioctl,
288 .d_poll = tunpoll,
289 .d_kqfilter = tunkqfilter,
290 .d_name = tunname,
291 },
292 .clone_match_fn = tun_clone_match,
293 .clone_create_fn = tun_clone_create,
294 .clone_destroy_fn = tun_clone_destroy,
295 },
296 {
297 .ident_flags = TUN_L2,
298 .cdevsw = {
299 .d_version = D_VERSION,
300 .d_flags = D_NEEDMINOR,
301 .d_open = tunopen,
302 .d_read = tunread,
303 .d_write = tunwrite,
304 .d_ioctl = tunioctl,
305 .d_poll = tunpoll,
306 .d_kqfilter = tunkqfilter,
307 .d_name = tapname,
308 },
309 .clone_match_fn = tap_clone_match,
310 .clone_create_fn = tun_clone_create,
311 .clone_destroy_fn = tun_clone_destroy,
312 },
313 {
314 .ident_flags = TUN_L2 | TUN_VMNET,
315 .cdevsw = {
316 .d_version = D_VERSION,
317 .d_flags = D_NEEDMINOR,
318 .d_open = tunopen,
319 .d_read = tunread,
320 .d_write = tunwrite,
321 .d_ioctl = tunioctl,
322 .d_poll = tunpoll,
323 .d_kqfilter = tunkqfilter,
324 .d_name = vmnetname,
325 },
326 .clone_match_fn = vmnet_clone_match,
327 .clone_create_fn = tun_clone_create,
328 .clone_destroy_fn = tun_clone_destroy,
329 },
330 };
331 #define NDRV nitems(tuntap_drivers)
332
333 VNET_DEFINE_STATIC(struct if_clone *, tuntap_driver_cloners[NDRV]);
334 #define V_tuntap_driver_cloners VNET(tuntap_driver_cloners)
335
336 /*
337 * Mechanism for marking a tunnel device as busy so that we can safely do some
338 * orthogonal operations (such as operations on devices) without racing against
339 * tun_destroy. tun_destroy will wait on the condvar if we're at all busy or
340 * open, to be woken up when the condition is alleviated.
341 */
342 static int
tun_busy_locked(struct tuntap_softc * tp)343 tun_busy_locked(struct tuntap_softc *tp)
344 {
345
346 TUN_LOCK_ASSERT(tp);
347 if ((tp->tun_flags & TUN_DYING) != 0) {
348 /*
349 * Perhaps unintuitive, but the device is busy going away.
350 * Other interpretations of EBUSY from tun_busy make little
351 * sense, since making a busy device even more busy doesn't
352 * sound like a problem.
353 */
354 return (EBUSY);
355 }
356
357 ++tp->tun_busy;
358 return (0);
359 }
360
361 static void
tun_unbusy_locked(struct tuntap_softc * tp)362 tun_unbusy_locked(struct tuntap_softc *tp)
363 {
364
365 TUN_LOCK_ASSERT(tp);
366 KASSERT(tp->tun_busy != 0, ("tun_unbusy: called for non-busy tunnel"));
367
368 --tp->tun_busy;
369 /* Wake up anything that may be waiting on our busy tunnel. */
370 if (tp->tun_busy == 0)
371 cv_broadcast(&tp->tun_cv);
372 }
373
374 static int
tun_busy(struct tuntap_softc * tp)375 tun_busy(struct tuntap_softc *tp)
376 {
377 int ret;
378
379 TUN_LOCK(tp);
380 ret = tun_busy_locked(tp);
381 TUN_UNLOCK(tp);
382 return (ret);
383 }
384
385 static void
tun_unbusy(struct tuntap_softc * tp)386 tun_unbusy(struct tuntap_softc *tp)
387 {
388
389 TUN_LOCK(tp);
390 tun_unbusy_locked(tp);
391 TUN_UNLOCK(tp);
392 }
393
394 /*
395 * Sets unit and/or flags given the device name. Must be called with correct
396 * vnet context.
397 */
398 static int
tuntap_name2info(const char * name,int * outunit,int * outflags)399 tuntap_name2info(const char *name, int *outunit, int *outflags)
400 {
401 struct tuntap_driver *drv;
402 char *dname;
403 int flags, unit;
404 bool found;
405
406 if (name == NULL)
407 return (EINVAL);
408
409 /*
410 * Needed for dev_stdclone, but dev_stdclone will not modify, it just
411 * wants to be able to pass back a char * through the second param. We
412 * will always set that as NULL here, so we'll fake it.
413 */
414 dname = __DECONST(char *, name);
415 found = false;
416
417 for (u_int i = 0; i < NDRV; i++) {
418 drv = &tuntap_drivers[i];
419
420 if (strcmp(name, drv->cdevsw.d_name) == 0) {
421 found = true;
422 unit = -1;
423 flags = drv->ident_flags;
424 break;
425 }
426
427 if (dev_stdclone(dname, NULL, drv->cdevsw.d_name, &unit) == 1) {
428 found = true;
429 flags = drv->ident_flags;
430 break;
431 }
432 }
433
434 if (!found)
435 return (ENXIO);
436
437 if (outunit != NULL)
438 *outunit = unit;
439 if (outflags != NULL)
440 *outflags = flags;
441 return (0);
442 }
443
444 /*
445 * Get driver information from a set of flags specified. Masks the identifying
446 * part of the flags and compares it against all of the available
447 * tuntap_drivers.
448 */
449 static struct tuntap_driver *
tuntap_driver_from_flags(int tun_flags)450 tuntap_driver_from_flags(int tun_flags)
451 {
452
453 for (u_int i = 0; i < NDRV; i++)
454 if ((tun_flags & TUN_DRIVER_IDENT_MASK) ==
455 tuntap_drivers[i].ident_flags)
456 return (&tuntap_drivers[i]);
457
458 return (NULL);
459 }
460
461 static int
tun_clone_match(struct if_clone * ifc,const char * name)462 tun_clone_match(struct if_clone *ifc, const char *name)
463 {
464 int tunflags;
465
466 if (tuntap_name2info(name, NULL, &tunflags) == 0) {
467 if ((tunflags & TUN_L2) == 0)
468 return (1);
469 }
470
471 return (0);
472 }
473
474 static int
tap_clone_match(struct if_clone * ifc,const char * name)475 tap_clone_match(struct if_clone *ifc, const char *name)
476 {
477 int tunflags;
478
479 if (tuntap_name2info(name, NULL, &tunflags) == 0) {
480 if ((tunflags & (TUN_L2 | TUN_VMNET)) == TUN_L2)
481 return (1);
482 }
483
484 return (0);
485 }
486
487 static int
vmnet_clone_match(struct if_clone * ifc,const char * name)488 vmnet_clone_match(struct if_clone *ifc, const char *name)
489 {
490 int tunflags;
491
492 if (tuntap_name2info(name, NULL, &tunflags) == 0) {
493 if ((tunflags & TUN_VMNET) != 0)
494 return (1);
495 }
496
497 return (0);
498 }
499
500 static int
tun_clone_create(struct if_clone * ifc,char * name,size_t len,struct ifc_data * ifd,struct ifnet ** ifpp)501 tun_clone_create(struct if_clone *ifc, char *name, size_t len,
502 struct ifc_data *ifd, struct ifnet **ifpp)
503 {
504 struct tuntap_driver *drv;
505 struct cdev *dev;
506 int err, i, tunflags, unit;
507
508 tunflags = 0;
509 /* The name here tells us exactly what we're creating */
510 err = tuntap_name2info(name, &unit, &tunflags);
511 if (err != 0)
512 return (err);
513
514 drv = tuntap_driver_from_flags(tunflags);
515 if (drv == NULL)
516 return (ENXIO);
517
518 if (unit != -1) {
519 /* If this unit number is still available that's okay. */
520 if (alloc_unr_specific(drv->unrhdr, unit) == -1)
521 return (EEXIST);
522 } else {
523 unit = alloc_unr(drv->unrhdr);
524 }
525
526 snprintf(name, IFNAMSIZ, "%s%d", drv->cdevsw.d_name, unit);
527
528 /* find any existing device, or allocate new unit number */
529 dev = NULL;
530 i = clone_create(&drv->clones, &drv->cdevsw, &unit, &dev, 0);
531 /* No preexisting struct cdev *, create one */
532 if (i != 0)
533 i = tun_create_device(drv, unit, NULL, &dev, name);
534 if (i == 0) {
535 dev_ref(dev);
536 tuncreate(dev);
537 struct tuntap_softc *tp = dev->si_drv1;
538 *ifpp = tp->tun_ifp;
539 }
540
541 return (i);
542 }
543
544 static void
tunclone(void * arg,struct ucred * cred,char * name,int namelen,struct cdev ** dev)545 tunclone(void *arg, struct ucred *cred, char *name, int namelen,
546 struct cdev **dev)
547 {
548 char devname[SPECNAMELEN + 1];
549 struct tuntap_driver *drv;
550 int append_unit, i, u, tunflags;
551 bool mayclone;
552
553 if (*dev != NULL)
554 return;
555
556 tunflags = 0;
557 CURVNET_SET(CRED_TO_VNET(cred));
558 if (tuntap_name2info(name, &u, &tunflags) != 0)
559 goto out; /* Not recognized */
560
561 if (u != -1 && u > IF_MAXUNIT)
562 goto out; /* Unit number too high */
563
564 mayclone = priv_check_cred(cred, PRIV_NET_IFCREATE) == 0;
565 if ((tunflags & TUN_L2) != 0) {
566 /* tap/vmnet allow user open with a sysctl */
567 mayclone = (mayclone || tap_allow_uopen) && tapdclone;
568 } else {
569 mayclone = mayclone && tundclone;
570 }
571
572 /*
573 * If tun cloning is enabled, only the superuser can create an
574 * interface.
575 */
576 if (!mayclone)
577 goto out;
578
579 if (u == -1)
580 append_unit = 1;
581 else
582 append_unit = 0;
583
584 drv = tuntap_driver_from_flags(tunflags);
585 if (drv == NULL)
586 goto out;
587
588 /* find any existing device, or allocate new unit number */
589 i = clone_create(&drv->clones, &drv->cdevsw, &u, dev, 0);
590 if (i) {
591 if (append_unit) {
592 namelen = snprintf(devname, sizeof(devname), "%s%d",
593 name, u);
594 name = devname;
595 }
596
597 i = tun_create_device(drv, u, cred, dev, name);
598 }
599 if (i == 0) {
600 dev_ref(*dev);
601 if_clone_create(name, namelen, NULL);
602 }
603 out:
604 CURVNET_RESTORE();
605 }
606
607 static void
tun_destroy(struct tuntap_softc * tp)608 tun_destroy(struct tuntap_softc *tp)
609 {
610
611 TUN_LOCK(tp);
612 tp->tun_flags |= TUN_DYING;
613 if (tp->tun_busy != 0)
614 cv_wait_unlock(&tp->tun_cv, &tp->tun_mtx);
615 else
616 TUN_UNLOCK(tp);
617
618 CURVNET_SET(TUN2IFP(tp)->if_vnet);
619
620 /* destroy_dev will take care of any alias. */
621 destroy_dev(tp->tun_dev);
622 seldrain(&tp->tun_rsel);
623 knlist_clear(&tp->tun_rsel.si_note, 0);
624 knlist_destroy(&tp->tun_rsel.si_note);
625 if ((tp->tun_flags & TUN_L2) != 0) {
626 ether_ifdetach(TUN2IFP(tp));
627 } else {
628 bpfdetach(TUN2IFP(tp));
629 if_detach(TUN2IFP(tp));
630 }
631 sx_xlock(&tun_ioctl_sx);
632 TUN2IFP(tp)->if_softc = NULL;
633 sx_xunlock(&tun_ioctl_sx);
634 free_unr(tp->tun_drv->unrhdr, TUN2IFP(tp)->if_dunit);
635 if_free(TUN2IFP(tp));
636 mtx_destroy(&tp->tun_mtx);
637 cv_destroy(&tp->tun_cv);
638 free(tp, M_TUN);
639 CURVNET_RESTORE();
640 }
641
642 static int
tun_clone_destroy(struct if_clone * ifc __unused,struct ifnet * ifp,uint32_t flags)643 tun_clone_destroy(struct if_clone *ifc __unused, struct ifnet *ifp, uint32_t flags)
644 {
645 struct tuntap_softc *tp = ifp->if_softc;
646
647 mtx_lock(&tunmtx);
648 TAILQ_REMOVE(&tunhead, tp, tun_list);
649 mtx_unlock(&tunmtx);
650 tun_destroy(tp);
651
652 return (0);
653 }
654
655 static void
vnet_tun_init(const void * unused __unused)656 vnet_tun_init(const void *unused __unused)
657 {
658
659 for (u_int i = 0; i < NDRV; ++i) {
660 struct if_clone_addreq req = {
661 .match_f = tuntap_drivers[i].clone_match_fn,
662 .create_f = tuntap_drivers[i].clone_create_fn,
663 .destroy_f = tuntap_drivers[i].clone_destroy_fn,
664 };
665 V_tuntap_driver_cloners[i] =
666 ifc_attach_cloner(tuntap_drivers[i].cdevsw.d_name, &req);
667 };
668 }
669 VNET_SYSINIT(vnet_tun_init, SI_SUB_PROTO_IF, SI_ORDER_ANY,
670 vnet_tun_init, NULL);
671
672 static void
vnet_tun_uninit(const void * unused __unused)673 vnet_tun_uninit(const void *unused __unused)
674 {
675
676 for (u_int i = 0; i < NDRV; ++i)
677 if_clone_detach(V_tuntap_driver_cloners[i]);
678 }
679 VNET_SYSUNINIT(vnet_tun_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY,
680 vnet_tun_uninit, NULL);
681
682 static void
tun_uninit(const void * unused __unused)683 tun_uninit(const void *unused __unused)
684 {
685 struct tuntap_driver *drv;
686 struct tuntap_softc *tp;
687 int i;
688
689 EVENTHANDLER_DEREGISTER(ifnet_arrival_event, arrival_tag);
690 EVENTHANDLER_DEREGISTER(dev_clone, clone_tag);
691
692 mtx_lock(&tunmtx);
693 while ((tp = TAILQ_FIRST(&tunhead)) != NULL) {
694 TAILQ_REMOVE(&tunhead, tp, tun_list);
695 mtx_unlock(&tunmtx);
696 tun_destroy(tp);
697 mtx_lock(&tunmtx);
698 }
699 mtx_unlock(&tunmtx);
700 for (i = 0; i < nitems(tuntap_drivers); ++i) {
701 drv = &tuntap_drivers[i];
702 delete_unrhdr(drv->unrhdr);
703 clone_cleanup(&drv->clones);
704 }
705 mtx_destroy(&tunmtx);
706 }
707 SYSUNINIT(tun_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY, tun_uninit, NULL);
708
709 static struct tuntap_driver *
tuntap_driver_from_ifnet(const struct ifnet * ifp)710 tuntap_driver_from_ifnet(const struct ifnet *ifp)
711 {
712 struct tuntap_driver *drv;
713 int i;
714
715 if (ifp == NULL)
716 return (NULL);
717
718 for (i = 0; i < nitems(tuntap_drivers); ++i) {
719 drv = &tuntap_drivers[i];
720 if (strcmp(ifp->if_dname, drv->cdevsw.d_name) == 0)
721 return (drv);
722 }
723
724 return (NULL);
725 }
726
727 static int
tuntapmodevent(module_t mod,int type,void * data)728 tuntapmodevent(module_t mod, int type, void *data)
729 {
730 struct tuntap_driver *drv;
731 int i;
732
733 switch (type) {
734 case MOD_LOAD:
735 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF);
736 for (i = 0; i < nitems(tuntap_drivers); ++i) {
737 drv = &tuntap_drivers[i];
738 clone_setup(&drv->clones);
739 drv->unrhdr = new_unrhdr(0, IF_MAXUNIT, &tunmtx);
740 }
741 arrival_tag = EVENTHANDLER_REGISTER(ifnet_arrival_event,
742 tunrename, 0, 1000);
743 if (arrival_tag == NULL)
744 return (ENOMEM);
745 clone_tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000);
746 if (clone_tag == NULL)
747 return (ENOMEM);
748 break;
749 case MOD_UNLOAD:
750 /* See tun_uninit, so it's done after the vnet_sysuninit() */
751 break;
752 default:
753 return EOPNOTSUPP;
754 }
755 return 0;
756 }
757
758 static moduledata_t tuntap_mod = {
759 "if_tuntap",
760 tuntapmodevent,
761 0
762 };
763
764 /* We'll only ever have these two, so no need for a macro. */
765 static moduledata_t tun_mod = { "if_tun", NULL, 0 };
766 static moduledata_t tap_mod = { "if_tap", NULL, 0 };
767
768 DECLARE_MODULE(if_tuntap, tuntap_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
769 MODULE_VERSION(if_tuntap, 1);
770 DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
771 MODULE_VERSION(if_tun, 1);
772 DECLARE_MODULE(if_tap, tap_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
773 MODULE_VERSION(if_tap, 1);
774
775 static int
tun_create_device(struct tuntap_driver * drv,int unit,struct ucred * cr,struct cdev ** dev,const char * name)776 tun_create_device(struct tuntap_driver *drv, int unit, struct ucred *cr,
777 struct cdev **dev, const char *name)
778 {
779 struct make_dev_args args;
780 struct tuntap_softc *tp;
781 int error;
782
783 tp = malloc(sizeof(*tp), M_TUN, M_WAITOK | M_ZERO);
784 mtx_init(&tp->tun_mtx, "tun_mtx", NULL, MTX_DEF);
785 cv_init(&tp->tun_cv, "tun_condvar");
786 tp->tun_flags = drv->ident_flags;
787 tp->tun_drv = drv;
788
789 make_dev_args_init(&args);
790 if (cr != NULL)
791 args.mda_flags = MAKEDEV_REF | MAKEDEV_CHECKNAME;
792 args.mda_devsw = &drv->cdevsw;
793 args.mda_cr = cr;
794 args.mda_uid = UID_UUCP;
795 args.mda_gid = GID_DIALER;
796 args.mda_mode = 0600;
797 args.mda_unit = unit;
798 args.mda_si_drv1 = tp;
799 error = make_dev_s(&args, dev, "%s", name);
800 if (error != 0) {
801 free(tp, M_TUN);
802 return (error);
803 }
804
805 KASSERT((*dev)->si_drv1 != NULL,
806 ("Failed to set si_drv1 at %s creation", name));
807 tp->tun_dev = *dev;
808 knlist_init_mtx(&tp->tun_rsel.si_note, &tp->tun_mtx);
809 mtx_lock(&tunmtx);
810 TAILQ_INSERT_TAIL(&tunhead, tp, tun_list);
811 mtx_unlock(&tunmtx);
812 return (0);
813 }
814
815 static void
tunstart(struct ifnet * ifp)816 tunstart(struct ifnet *ifp)
817 {
818 struct tuntap_softc *tp = ifp->if_softc;
819 struct mbuf *m;
820
821 TUNDEBUG(ifp, "starting\n");
822 if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
823 IFQ_LOCK(&ifp->if_snd);
824 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
825 if (m == NULL) {
826 IFQ_UNLOCK(&ifp->if_snd);
827 return;
828 }
829 IFQ_UNLOCK(&ifp->if_snd);
830 }
831
832 TUN_LOCK(tp);
833 if (tp->tun_flags & TUN_RWAIT) {
834 tp->tun_flags &= ~TUN_RWAIT;
835 wakeup(tp);
836 }
837 selwakeuppri(&tp->tun_rsel, PZERO + 1);
838 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
839 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) {
840 TUN_UNLOCK(tp);
841 pgsigio(&tp->tun_sigio, SIGIO, 0);
842 } else
843 TUN_UNLOCK(tp);
844 }
845
846 /*
847 * tunstart_l2
848 *
849 * queue packets from higher level ready to put out
850 */
851 static void
tunstart_l2(struct ifnet * ifp)852 tunstart_l2(struct ifnet *ifp)
853 {
854 struct tuntap_softc *tp = ifp->if_softc;
855
856 TUNDEBUG(ifp, "starting\n");
857
858 /*
859 * do not junk pending output if we are in VMnet mode.
860 * XXX: can this do any harm because of queue overflow?
861 */
862
863 TUN_LOCK(tp);
864 if (((tp->tun_flags & TUN_VMNET) == 0) &&
865 ((tp->tun_flags & TUN_READY) != TUN_READY)) {
866 struct mbuf *m;
867
868 /* Unlocked read. */
869 TUNDEBUG(ifp, "not ready, tun_flags = 0x%x\n", tp->tun_flags);
870
871 for (;;) {
872 IF_DEQUEUE(&ifp->if_snd, m);
873 if (m != NULL) {
874 m_freem(m);
875 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
876 } else
877 break;
878 }
879 TUN_UNLOCK(tp);
880
881 return;
882 }
883
884 ifp->if_drv_flags |= IFF_DRV_OACTIVE;
885
886 if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
887 if (tp->tun_flags & TUN_RWAIT) {
888 tp->tun_flags &= ~TUN_RWAIT;
889 wakeup(tp);
890 }
891
892 if ((tp->tun_flags & TUN_ASYNC) && (tp->tun_sigio != NULL)) {
893 TUN_UNLOCK(tp);
894 pgsigio(&tp->tun_sigio, SIGIO, 0);
895 TUN_LOCK(tp);
896 }
897
898 selwakeuppri(&tp->tun_rsel, PZERO+1);
899 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
900 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); /* obytes are counted in ether_output */
901 }
902
903 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
904 TUN_UNLOCK(tp);
905 } /* tunstart_l2 */
906
907 static int
tap_transmit(struct ifnet * ifp,struct mbuf * m)908 tap_transmit(struct ifnet *ifp, struct mbuf *m)
909 {
910 int error;
911
912 BPF_MTAP(ifp, m);
913 IFQ_HANDOFF(ifp, m, error);
914 return (error);
915 }
916
917 /* XXX: should return an error code so it can fail. */
918 static void
tuncreate(struct cdev * dev)919 tuncreate(struct cdev *dev)
920 {
921 struct tuntap_driver *drv;
922 struct tuntap_softc *tp;
923 struct ifnet *ifp;
924 struct ether_addr eaddr;
925 int iflags;
926 u_char type;
927
928 tp = dev->si_drv1;
929 KASSERT(tp != NULL,
930 ("si_drv1 should have been initialized at creation"));
931
932 drv = tp->tun_drv;
933 iflags = IFF_MULTICAST;
934 if ((tp->tun_flags & TUN_L2) != 0) {
935 type = IFT_ETHER;
936 iflags |= IFF_BROADCAST | IFF_SIMPLEX;
937 } else {
938 type = IFT_PPP;
939 iflags |= IFF_POINTOPOINT;
940 }
941 ifp = tp->tun_ifp = if_alloc(type);
942 ifp->if_softc = tp;
943 if_initname(ifp, drv->cdevsw.d_name, dev2unit(dev));
944 ifp->if_ioctl = tunifioctl;
945 ifp->if_flags = iflags;
946 IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
947 ifp->if_capabilities |= IFCAP_LINKSTATE | IFCAP_MEXTPG;
948 if ((tp->tun_flags & TUN_L2) != 0)
949 ifp->if_capabilities |=
950 IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6 | IFCAP_LRO;
951 ifp->if_capenable |= IFCAP_LINKSTATE | IFCAP_MEXTPG;
952
953 if ((tp->tun_flags & TUN_L2) != 0) {
954 ifp->if_init = tunifinit;
955 ifp->if_start = tunstart_l2;
956 ifp->if_transmit = tap_transmit;
957 ifp->if_qflush = if_qflush;
958
959 ether_gen_addr(ifp, &eaddr);
960 ether_ifattach(ifp, eaddr.octet);
961 } else {
962 ifp->if_mtu = TUNMTU;
963 ifp->if_start = tunstart;
964 ifp->if_output = tunoutput;
965
966 ifp->if_snd.ifq_drv_maxlen = 0;
967 IFQ_SET_READY(&ifp->if_snd);
968
969 if_attach(ifp);
970 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
971 }
972
973 TUN_LOCK(tp);
974 tp->tun_flags |= TUN_INITED;
975 TUN_UNLOCK(tp);
976
977 TUNDEBUG(ifp, "interface %s is created, minor = %#x\n",
978 ifp->if_xname, dev2unit(dev));
979 }
980
981 static void
tunrename(void * arg __unused,struct ifnet * ifp)982 tunrename(void *arg __unused, struct ifnet *ifp)
983 {
984 struct tuntap_softc *tp;
985 int error;
986
987 if ((ifp->if_flags & IFF_RENAMING) == 0)
988 return;
989
990 if (tuntap_driver_from_ifnet(ifp) == NULL)
991 return;
992
993 /*
994 * We need to grab the ioctl sx long enough to make sure the softc is
995 * still there. If it is, we can safely try to busy the tun device.
996 * The busy may fail if the device is currently dying, in which case
997 * we do nothing. If it doesn't fail, the busy count stops the device
998 * from dying until we've created the alias (that will then be
999 * subsequently destroyed).
1000 */
1001 sx_xlock(&tun_ioctl_sx);
1002 tp = ifp->if_softc;
1003 if (tp == NULL) {
1004 sx_xunlock(&tun_ioctl_sx);
1005 return;
1006 }
1007 error = tun_busy(tp);
1008 sx_xunlock(&tun_ioctl_sx);
1009 if (error != 0)
1010 return;
1011 if (tp->tun_alias != NULL) {
1012 destroy_dev(tp->tun_alias);
1013 tp->tun_alias = NULL;
1014 }
1015
1016 if (strcmp(ifp->if_xname, tp->tun_dev->si_name) == 0)
1017 goto out;
1018
1019 /*
1020 * Failure's ok, aliases are created on a best effort basis. If a
1021 * tun user/consumer decides to rename the interface to conflict with
1022 * another device (non-ifnet) on the system, we will assume they know
1023 * what they are doing. make_dev_alias_p won't touch tun_alias on
1024 * failure, so we use it but ignore the return value.
1025 */
1026 make_dev_alias_p(MAKEDEV_CHECKNAME, &tp->tun_alias, tp->tun_dev, "%s",
1027 ifp->if_xname);
1028 out:
1029 tun_unbusy(tp);
1030 }
1031
1032 static int
tunopen(struct cdev * dev,int flag,int mode,struct thread * td)1033 tunopen(struct cdev *dev, int flag, int mode, struct thread *td)
1034 {
1035 struct ifnet *ifp;
1036 struct tuntap_softc *tp;
1037 int error __diagused, tunflags;
1038
1039 tunflags = 0;
1040 CURVNET_SET(TD_TO_VNET(td));
1041 error = tuntap_name2info(dev->si_name, NULL, &tunflags);
1042 if (error != 0) {
1043 CURVNET_RESTORE();
1044 return (error); /* Shouldn't happen */
1045 }
1046
1047 tp = dev->si_drv1;
1048 KASSERT(tp != NULL,
1049 ("si_drv1 should have been initialized at creation"));
1050
1051 TUN_LOCK(tp);
1052 if ((tp->tun_flags & TUN_INITED) == 0) {
1053 TUN_UNLOCK(tp);
1054 CURVNET_RESTORE();
1055 return (ENXIO);
1056 }
1057 if ((tp->tun_flags & (TUN_OPEN | TUN_DYING)) != 0) {
1058 TUN_UNLOCK(tp);
1059 CURVNET_RESTORE();
1060 return (EBUSY);
1061 }
1062
1063 error = tun_busy_locked(tp);
1064 KASSERT(error == 0, ("Must be able to busy an unopen tunnel"));
1065 ifp = TUN2IFP(tp);
1066
1067 if ((tp->tun_flags & TUN_L2) != 0) {
1068 bcopy(IF_LLADDR(ifp), tp->tun_ether.octet,
1069 sizeof(tp->tun_ether.octet));
1070
1071 ifp->if_drv_flags |= IFF_DRV_RUNNING;
1072 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1073
1074 if (tapuponopen)
1075 ifp->if_flags |= IFF_UP;
1076 }
1077
1078 tp->tun_pid = td->td_proc->p_pid;
1079 tp->tun_flags |= TUN_OPEN;
1080
1081 if_link_state_change(ifp, LINK_STATE_UP);
1082 TUNDEBUG(ifp, "open\n");
1083 TUN_UNLOCK(tp);
1084
1085 /*
1086 * This can fail with either ENOENT or EBUSY. This is in the middle of
1087 * d_open, so ENOENT should not be possible. EBUSY is possible, but
1088 * the only cdevpriv dtor being set will be tundtor and the softc being
1089 * passed is constant for a given cdev. We ignore the possible error
1090 * because of this as either "unlikely" or "not actually a problem."
1091 */
1092 (void)devfs_set_cdevpriv(tp, tundtor);
1093 CURVNET_RESTORE();
1094 return (0);
1095 }
1096
1097 /*
1098 * tundtor - tear down the device - mark i/f down & delete
1099 * routing info
1100 */
1101 static void
tundtor(void * data)1102 tundtor(void *data)
1103 {
1104 struct proc *p;
1105 struct tuntap_softc *tp;
1106 struct ifnet *ifp;
1107 bool l2tun;
1108
1109 tp = data;
1110 p = curproc;
1111 ifp = TUN2IFP(tp);
1112
1113 TUN_LOCK(tp);
1114
1115 /*
1116 * Realistically, we can't be obstinate here. This only means that the
1117 * tuntap device was closed out of order, and the last closer wasn't the
1118 * controller. These are still good to know about, though, as software
1119 * should avoid multiple processes with a tuntap device open and
1120 * ill-defined transfer of control (e.g., handoff, TUNSIFPID, close in
1121 * parent).
1122 */
1123 if (p->p_pid != tp->tun_pid) {
1124 log(LOG_INFO,
1125 "pid %d (%s), %s: tun/tap protocol violation, non-controlling process closed last.\n",
1126 p->p_pid, p->p_comm, tp->tun_dev->si_name);
1127 }
1128
1129 /*
1130 * junk all pending output
1131 */
1132 CURVNET_SET(ifp->if_vnet);
1133
1134 l2tun = false;
1135 if ((tp->tun_flags & TUN_L2) != 0) {
1136 l2tun = true;
1137 IF_DRAIN(&ifp->if_snd);
1138 } else {
1139 IFQ_PURGE(&ifp->if_snd);
1140 }
1141
1142 /* For vmnet, we won't do most of the address/route bits */
1143 if ((tp->tun_flags & TUN_VMNET) != 0 ||
1144 (l2tun && (ifp->if_flags & IFF_LINK0) != 0))
1145 goto out;
1146 #if defined(INET) || defined(INET6)
1147 if (l2tun && tp->tun_lro_ready) {
1148 TUNDEBUG (ifp, "LRO disabled\n");
1149 tcp_lro_free(&tp->tun_lro);
1150 tp->tun_lro_ready = false;
1151 }
1152 #endif
1153 if (ifp->if_flags & IFF_UP) {
1154 TUN_UNLOCK(tp);
1155 if_down(ifp);
1156 TUN_LOCK(tp);
1157 }
1158
1159 /* Delete all addresses and routes which reference this interface. */
1160 if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
1161 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1162 TUN_UNLOCK(tp);
1163 if_purgeaddrs(ifp);
1164 TUN_LOCK(tp);
1165 }
1166
1167 out:
1168 if_link_state_change(ifp, LINK_STATE_DOWN);
1169 CURVNET_RESTORE();
1170
1171 funsetown(&tp->tun_sigio);
1172 selwakeuppri(&tp->tun_rsel, PZERO + 1);
1173 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
1174 TUNDEBUG (ifp, "closed\n");
1175 tp->tun_flags &= ~TUN_OPEN;
1176 tp->tun_pid = 0;
1177 tun_vnethdr_set(ifp, 0);
1178
1179 tun_unbusy_locked(tp);
1180 TUN_UNLOCK(tp);
1181 }
1182
1183 static void
tuninit(struct ifnet * ifp)1184 tuninit(struct ifnet *ifp)
1185 {
1186 struct tuntap_softc *tp = ifp->if_softc;
1187
1188 TUNDEBUG(ifp, "tuninit\n");
1189
1190 TUN_LOCK(tp);
1191 ifp->if_drv_flags |= IFF_DRV_RUNNING;
1192 if ((tp->tun_flags & TUN_L2) == 0) {
1193 ifp->if_flags |= IFF_UP;
1194 getmicrotime(&ifp->if_lastchange);
1195 TUN_UNLOCK(tp);
1196 } else {
1197 #if defined(INET) || defined(INET6)
1198 if (tcp_lro_init(&tp->tun_lro) == 0) {
1199 TUNDEBUG(ifp, "LRO enabled\n");
1200 tp->tun_lro.ifp = ifp;
1201 tp->tun_lro_ready = true;
1202 } else {
1203 TUNDEBUG(ifp, "Could not enable LRO\n");
1204 tp->tun_lro_ready = false;
1205 }
1206 #endif
1207 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1208 TUN_UNLOCK(tp);
1209 /* attempt to start output */
1210 tunstart_l2(ifp);
1211 }
1212
1213 }
1214
1215 /*
1216 * Used only for l2 tunnel.
1217 */
1218 static void
tunifinit(void * xtp)1219 tunifinit(void *xtp)
1220 {
1221 struct tuntap_softc *tp;
1222
1223 tp = (struct tuntap_softc *)xtp;
1224 tuninit(tp->tun_ifp);
1225 }
1226
1227 /*
1228 * To be called under TUN_LOCK. Update ifp->if_hwassist according to the
1229 * current value of ifp->if_capenable.
1230 */
1231 static void
tun_caps_changed(struct ifnet * ifp)1232 tun_caps_changed(struct ifnet *ifp)
1233 {
1234 uint64_t hwassist = 0;
1235
1236 TUN_LOCK_ASSERT((struct tuntap_softc *)ifp->if_softc);
1237 if (ifp->if_capenable & IFCAP_TXCSUM)
1238 hwassist |= CSUM_TCP | CSUM_UDP;
1239 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
1240 hwassist |= CSUM_TCP_IPV6
1241 | CSUM_UDP_IPV6;
1242 if (ifp->if_capenable & IFCAP_TSO4)
1243 hwassist |= CSUM_IP_TSO;
1244 if (ifp->if_capenable & IFCAP_TSO6)
1245 hwassist |= CSUM_IP6_TSO;
1246 ifp->if_hwassist = hwassist;
1247 }
1248
1249 /*
1250 * To be called under TUN_LOCK. Update tp->tun_vhdrlen and adjust
1251 * if_capabilities and if_capenable as needed.
1252 */
1253 static void
tun_vnethdr_set(struct ifnet * ifp,int vhdrlen)1254 tun_vnethdr_set(struct ifnet *ifp, int vhdrlen)
1255 {
1256 struct tuntap_softc *tp = ifp->if_softc;
1257
1258 TUN_LOCK_ASSERT(tp);
1259
1260 if (tp->tun_vhdrlen == vhdrlen)
1261 return;
1262
1263 /*
1264 * Update if_capabilities to reflect the
1265 * functionalities offered by the virtio-net
1266 * header.
1267 */
1268 if (vhdrlen != 0)
1269 ifp->if_capabilities |=
1270 TAP_VNET_HDR_CAPS;
1271 else
1272 ifp->if_capabilities &=
1273 ~TAP_VNET_HDR_CAPS;
1274 /*
1275 * Disable any capabilities that we don't
1276 * support anymore.
1277 */
1278 ifp->if_capenable &= ifp->if_capabilities;
1279 tun_caps_changed(ifp);
1280 tp->tun_vhdrlen = vhdrlen;
1281
1282 TUNDEBUG(ifp, "vnet_hdr_len=%d, if_capabilities=%x\n",
1283 vhdrlen, ifp->if_capabilities);
1284 }
1285
1286 /*
1287 * Process an ioctl request.
1288 */
1289 static int
tunifioctl(struct ifnet * ifp,u_long cmd,caddr_t data)1290 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1291 {
1292 struct ifreq *ifr = (struct ifreq *)data;
1293 struct tuntap_softc *tp;
1294 struct ifstat *ifs;
1295 struct ifmediareq *ifmr;
1296 int dummy, error = 0;
1297 bool l2tun;
1298
1299 ifmr = NULL;
1300 sx_xlock(&tun_ioctl_sx);
1301 tp = ifp->if_softc;
1302 if (tp == NULL) {
1303 error = ENXIO;
1304 goto bad;
1305 }
1306 l2tun = (tp->tun_flags & TUN_L2) != 0;
1307 switch(cmd) {
1308 case SIOCGIFSTATUS:
1309 ifs = (struct ifstat *)data;
1310 TUN_LOCK(tp);
1311 if (tp->tun_pid)
1312 snprintf(ifs->ascii, sizeof(ifs->ascii),
1313 "\tOpened by PID %d\n", tp->tun_pid);
1314 else
1315 ifs->ascii[0] = '\0';
1316 TUN_UNLOCK(tp);
1317 break;
1318 case SIOCSIFADDR:
1319 if (l2tun)
1320 error = ether_ioctl(ifp, cmd, data);
1321 else
1322 tuninit(ifp);
1323 if (error == 0)
1324 TUNDEBUG(ifp, "address set\n");
1325 break;
1326 case SIOCSIFMTU:
1327 ifp->if_mtu = ifr->ifr_mtu;
1328 TUNDEBUG(ifp, "mtu set\n");
1329 break;
1330 case SIOCSIFFLAGS:
1331 case SIOCADDMULTI:
1332 case SIOCDELMULTI:
1333 break;
1334 case SIOCGIFMEDIA:
1335 if (!l2tun) {
1336 error = EINVAL;
1337 break;
1338 }
1339
1340 ifmr = (struct ifmediareq *)data;
1341 dummy = ifmr->ifm_count;
1342 ifmr->ifm_count = 1;
1343 ifmr->ifm_status = IFM_AVALID;
1344 ifmr->ifm_active = IFM_ETHER | IFM_FDX | IFM_1000_T;
1345 if (tp->tun_flags & TUN_OPEN)
1346 ifmr->ifm_status |= IFM_ACTIVE;
1347 ifmr->ifm_current = ifmr->ifm_active;
1348 if (dummy >= 1) {
1349 int media = IFM_ETHER;
1350 error = copyout(&media, ifmr->ifm_ulist, sizeof(int));
1351 }
1352 break;
1353 case SIOCSIFCAP:
1354 TUN_LOCK(tp);
1355 ifp->if_capenable = ifr->ifr_reqcap;
1356 tun_caps_changed(ifp);
1357 TUN_UNLOCK(tp);
1358 VLAN_CAPABILITIES(ifp);
1359 break;
1360 default:
1361 if (l2tun) {
1362 error = ether_ioctl(ifp, cmd, data);
1363 } else {
1364 error = EINVAL;
1365 }
1366 }
1367 bad:
1368 sx_xunlock(&tun_ioctl_sx);
1369 return (error);
1370 }
1371
1372 /*
1373 * tunoutput - queue packets from higher level ready to put out.
1374 */
1375 static int
tunoutput(struct ifnet * ifp,struct mbuf * m0,const struct sockaddr * dst,struct route * ro)1376 tunoutput(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
1377 struct route *ro)
1378 {
1379 struct tuntap_softc *tp = ifp->if_softc;
1380 u_short cached_tun_flags;
1381 int error;
1382 u_int32_t af;
1383
1384 TUNDEBUG (ifp, "tunoutput\n");
1385
1386 #ifdef MAC
1387 error = mac_ifnet_check_transmit(ifp, m0);
1388 if (error) {
1389 m_freem(m0);
1390 return (error);
1391 }
1392 #endif
1393
1394 /* Could be unlocked read? */
1395 TUN_LOCK(tp);
1396 cached_tun_flags = tp->tun_flags;
1397 TUN_UNLOCK(tp);
1398 if ((cached_tun_flags & TUN_READY) != TUN_READY) {
1399 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
1400 m_freem (m0);
1401 return (EHOSTDOWN);
1402 }
1403
1404 if ((ifp->if_flags & IFF_UP) != IFF_UP) {
1405 m_freem (m0);
1406 return (EHOSTDOWN);
1407 }
1408
1409 /* BPF writes need to be handled specially. */
1410 if (dst->sa_family == AF_UNSPEC || dst->sa_family == pseudo_AF_HDRCMPLT)
1411 bcopy(dst->sa_data, &af, sizeof(af));
1412 else
1413 af = RO_GET_FAMILY(ro, dst);
1414
1415 BPF_MTAP2(ifp, &af, sizeof(af), m0);
1416
1417 /* prepend sockaddr? this may abort if the mbuf allocation fails */
1418 if (cached_tun_flags & TUN_LMODE) {
1419 /* allocate space for sockaddr */
1420 M_PREPEND(m0, dst->sa_len, M_NOWAIT);
1421
1422 /* if allocation failed drop packet */
1423 if (m0 == NULL) {
1424 if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1425 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1426 return (ENOBUFS);
1427 } else {
1428 bcopy(dst, m0->m_data, dst->sa_len);
1429 }
1430 }
1431
1432 if (cached_tun_flags & TUN_IFHEAD) {
1433 /* Prepend the address family */
1434 M_PREPEND(m0, 4, M_NOWAIT);
1435
1436 /* if allocation failed drop packet */
1437 if (m0 == NULL) {
1438 if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1439 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1440 return (ENOBUFS);
1441 } else
1442 *(u_int32_t *)m0->m_data = htonl(af);
1443 } else {
1444 #ifdef INET
1445 if (af != AF_INET)
1446 #endif
1447 {
1448 m_freem(m0);
1449 return (EAFNOSUPPORT);
1450 }
1451 }
1452
1453 error = (ifp->if_transmit)(ifp, m0);
1454 if (error)
1455 return (ENOBUFS);
1456 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
1457 return (0);
1458 }
1459
1460 /*
1461 * the cdevsw interface is now pretty minimal.
1462 */
1463 static int
tunioctl(struct cdev * dev,u_long cmd,caddr_t data,int flag,struct thread * td)1464 tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag,
1465 struct thread *td)
1466 {
1467 struct ifreq ifr, *ifrp;
1468 struct tuntap_softc *tp = dev->si_drv1;
1469 struct ifnet *ifp = TUN2IFP(tp);
1470 struct tuninfo *tunp;
1471 int error, iflags, ival;
1472 bool l2tun;
1473
1474 l2tun = (tp->tun_flags & TUN_L2) != 0;
1475 if (l2tun) {
1476 /* tap specific ioctls */
1477 switch(cmd) {
1478 /* VMware/VMnet port ioctl's */
1479 #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
1480 defined(COMPAT_FREEBSD4)
1481 case _IO('V', 0):
1482 ival = IOCPARM_IVAL(data);
1483 data = (caddr_t)&ival;
1484 /* FALLTHROUGH */
1485 #endif
1486 case VMIO_SIOCSIFFLAGS: /* VMware/VMnet SIOCSIFFLAGS */
1487 iflags = *(int *)data;
1488 iflags &= TUN_VMIO_FLAG_MASK;
1489 iflags &= ~IFF_CANTCHANGE;
1490 iflags |= IFF_UP;
1491
1492 TUN_LOCK(tp);
1493 ifp->if_flags = iflags |
1494 (ifp->if_flags & IFF_CANTCHANGE);
1495 TUN_UNLOCK(tp);
1496
1497 return (0);
1498 case SIOCGIFADDR: /* get MAC address of the remote side */
1499 TUN_LOCK(tp);
1500 bcopy(&tp->tun_ether.octet, data,
1501 sizeof(tp->tun_ether.octet));
1502 TUN_UNLOCK(tp);
1503
1504 return (0);
1505 case SIOCSIFADDR: /* set MAC address of the remote side */
1506 TUN_LOCK(tp);
1507 bcopy(data, &tp->tun_ether.octet,
1508 sizeof(tp->tun_ether.octet));
1509 TUN_UNLOCK(tp);
1510
1511 return (0);
1512 case TAPSVNETHDR:
1513 ival = *(int *)data;
1514 if (ival != 0 &&
1515 ival != sizeof(struct virtio_net_hdr) &&
1516 ival != sizeof(struct virtio_net_hdr_mrg_rxbuf)) {
1517 return (EINVAL);
1518 }
1519 TUN_LOCK(tp);
1520 tun_vnethdr_set(ifp, ival);
1521 TUN_UNLOCK(tp);
1522
1523 return (0);
1524 case TAPGVNETHDR:
1525 TUN_LOCK(tp);
1526 *(int *)data = tp->tun_vhdrlen;
1527 TUN_UNLOCK(tp);
1528
1529 return (0);
1530 }
1531
1532 /* Fall through to the common ioctls if unhandled */
1533 } else {
1534 switch (cmd) {
1535 case TUNSLMODE:
1536 TUN_LOCK(tp);
1537 if (*(int *)data) {
1538 tp->tun_flags |= TUN_LMODE;
1539 tp->tun_flags &= ~TUN_IFHEAD;
1540 } else
1541 tp->tun_flags &= ~TUN_LMODE;
1542 TUN_UNLOCK(tp);
1543
1544 return (0);
1545 case TUNSIFHEAD:
1546 TUN_LOCK(tp);
1547 if (*(int *)data) {
1548 tp->tun_flags |= TUN_IFHEAD;
1549 tp->tun_flags &= ~TUN_LMODE;
1550 } else
1551 tp->tun_flags &= ~TUN_IFHEAD;
1552 TUN_UNLOCK(tp);
1553
1554 return (0);
1555 case TUNGIFHEAD:
1556 TUN_LOCK(tp);
1557 *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
1558 TUN_UNLOCK(tp);
1559
1560 return (0);
1561 case TUNSIFMODE:
1562 /* deny this if UP */
1563 if (TUN2IFP(tp)->if_flags & IFF_UP)
1564 return (EBUSY);
1565
1566 switch (*(int *)data & ~IFF_MULTICAST) {
1567 case IFF_POINTOPOINT:
1568 case IFF_BROADCAST:
1569 TUN_LOCK(tp);
1570 TUN2IFP(tp)->if_flags &=
1571 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
1572 TUN2IFP(tp)->if_flags |= *(int *)data;
1573 TUN_UNLOCK(tp);
1574
1575 break;
1576 default:
1577 return (EINVAL);
1578 }
1579
1580 return (0);
1581 case TUNSIFPID:
1582 TUN_LOCK(tp);
1583 tp->tun_pid = curthread->td_proc->p_pid;
1584 TUN_UNLOCK(tp);
1585
1586 return (0);
1587 }
1588 /* Fall through to the common ioctls if unhandled */
1589 }
1590
1591 switch (cmd) {
1592 case TUNGIFNAME:
1593 ifrp = (struct ifreq *)data;
1594 strlcpy(ifrp->ifr_name, TUN2IFP(tp)->if_xname, IFNAMSIZ);
1595
1596 return (0);
1597 case TUNSIFINFO:
1598 tunp = (struct tuninfo *)data;
1599 if (TUN2IFP(tp)->if_type != tunp->type)
1600 return (EPROTOTYPE);
1601 TUN_LOCK(tp);
1602 if (TUN2IFP(tp)->if_mtu != tunp->mtu) {
1603 strlcpy(ifr.ifr_name, if_name(TUN2IFP(tp)), IFNAMSIZ);
1604 ifr.ifr_mtu = tunp->mtu;
1605 CURVNET_SET(TUN2IFP(tp)->if_vnet);
1606 error = ifhwioctl(SIOCSIFMTU, TUN2IFP(tp),
1607 (caddr_t)&ifr, td);
1608 CURVNET_RESTORE();
1609 if (error) {
1610 TUN_UNLOCK(tp);
1611 return (error);
1612 }
1613 }
1614 TUN2IFP(tp)->if_baudrate = tunp->baudrate;
1615 TUN_UNLOCK(tp);
1616 break;
1617 case TUNGIFINFO:
1618 tunp = (struct tuninfo *)data;
1619 TUN_LOCK(tp);
1620 tunp->mtu = TUN2IFP(tp)->if_mtu;
1621 tunp->type = TUN2IFP(tp)->if_type;
1622 tunp->baudrate = TUN2IFP(tp)->if_baudrate;
1623 TUN_UNLOCK(tp);
1624 break;
1625 case TUNSDEBUG:
1626 tundebug = *(int *)data;
1627 break;
1628 case TUNGDEBUG:
1629 *(int *)data = tundebug;
1630 break;
1631 case FIONBIO:
1632 break;
1633 case FIOASYNC:
1634 TUN_LOCK(tp);
1635 if (*(int *)data)
1636 tp->tun_flags |= TUN_ASYNC;
1637 else
1638 tp->tun_flags &= ~TUN_ASYNC;
1639 TUN_UNLOCK(tp);
1640 break;
1641 case FIONREAD:
1642 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) {
1643 struct mbuf *mb;
1644 IFQ_LOCK(&TUN2IFP(tp)->if_snd);
1645 IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb);
1646 for (*(int *)data = 0; mb != NULL; mb = mb->m_next)
1647 *(int *)data += mb->m_len;
1648 IFQ_UNLOCK(&TUN2IFP(tp)->if_snd);
1649 } else
1650 *(int *)data = 0;
1651 break;
1652 case FIOSETOWN:
1653 return (fsetown(*(int *)data, &tp->tun_sigio));
1654
1655 case FIOGETOWN:
1656 *(int *)data = fgetown(&tp->tun_sigio);
1657 return (0);
1658
1659 /* This is deprecated, FIOSETOWN should be used instead. */
1660 case TIOCSPGRP:
1661 return (fsetown(-(*(int *)data), &tp->tun_sigio));
1662
1663 /* This is deprecated, FIOGETOWN should be used instead. */
1664 case TIOCGPGRP:
1665 *(int *)data = -fgetown(&tp->tun_sigio);
1666 return (0);
1667
1668 default:
1669 return (ENOTTY);
1670 }
1671 return (0);
1672 }
1673
1674 /*
1675 * The cdevsw read interface - reads a packet at a time, or at
1676 * least as much of a packet as can be read.
1677 */
1678 static int
tunread(struct cdev * dev,struct uio * uio,int flag)1679 tunread(struct cdev *dev, struct uio *uio, int flag)
1680 {
1681 struct tuntap_softc *tp = dev->si_drv1;
1682 struct ifnet *ifp = TUN2IFP(tp);
1683 struct mbuf *m;
1684 size_t len;
1685 int error = 0;
1686
1687 TUNDEBUG (ifp, "read\n");
1688 TUN_LOCK(tp);
1689 if ((tp->tun_flags & TUN_READY) != TUN_READY) {
1690 TUN_UNLOCK(tp);
1691 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
1692 return (EHOSTDOWN);
1693 }
1694
1695 tp->tun_flags &= ~TUN_RWAIT;
1696
1697 for (;;) {
1698 IFQ_DEQUEUE(&ifp->if_snd, m);
1699 if (m != NULL)
1700 break;
1701 if (flag & O_NONBLOCK) {
1702 TUN_UNLOCK(tp);
1703 return (EWOULDBLOCK);
1704 }
1705 tp->tun_flags |= TUN_RWAIT;
1706 error = mtx_sleep(tp, &tp->tun_mtx, PCATCH | (PZERO + 1),
1707 "tunread", 0);
1708 if (error != 0) {
1709 TUN_UNLOCK(tp);
1710 return (error);
1711 }
1712 }
1713 TUN_UNLOCK(tp);
1714
1715 len = min(tp->tun_vhdrlen, uio->uio_resid);
1716 if (len > 0) {
1717 struct virtio_net_hdr_mrg_rxbuf vhdr;
1718
1719 bzero(&vhdr, sizeof(vhdr));
1720 if (m->m_pkthdr.csum_flags & TAP_ALL_OFFLOAD) {
1721 m = virtio_net_tx_offload(ifp, m, false, &vhdr.hdr);
1722 }
1723
1724 TUNDEBUG(ifp, "txvhdr: f %u, gt %u, hl %u, "
1725 "gs %u, cs %u, co %u\n", vhdr.hdr.flags,
1726 vhdr.hdr.gso_type, vhdr.hdr.hdr_len,
1727 vhdr.hdr.gso_size, vhdr.hdr.csum_start,
1728 vhdr.hdr.csum_offset);
1729 error = uiomove(&vhdr, len, uio);
1730 }
1731 if (error == 0)
1732 error = m_mbuftouio(uio, m, 0);
1733 m_freem(m);
1734 return (error);
1735 }
1736
1737 static int
tunwrite_l2(struct tuntap_softc * tp,struct mbuf * m,struct virtio_net_hdr_mrg_rxbuf * vhdr)1738 tunwrite_l2(struct tuntap_softc *tp, struct mbuf *m,
1739 struct virtio_net_hdr_mrg_rxbuf *vhdr)
1740 {
1741 struct epoch_tracker et;
1742 struct ether_header *eh;
1743 struct ifnet *ifp;
1744
1745 ifp = TUN2IFP(tp);
1746
1747 /*
1748 * Only pass a unicast frame to ether_input(), if it would
1749 * actually have been received by non-virtual hardware.
1750 */
1751 if (m->m_len < sizeof(struct ether_header)) {
1752 m_freem(m);
1753 return (0);
1754 }
1755
1756 eh = mtod(m, struct ether_header *);
1757
1758 if ((ifp->if_flags & IFF_PROMISC) == 0 &&
1759 !ETHER_IS_MULTICAST(eh->ether_dhost) &&
1760 bcmp(eh->ether_dhost, IF_LLADDR(ifp), ETHER_ADDR_LEN) != 0) {
1761 m_freem(m);
1762 return (0);
1763 }
1764
1765 if (vhdr != NULL) {
1766 if (virtio_net_rx_csum(m, &vhdr->hdr)) {
1767 m_freem(m);
1768 return (0);
1769 }
1770 } else {
1771 switch (ntohs(eh->ether_type)) {
1772 #ifdef INET
1773 case ETHERTYPE_IP:
1774 if (ifp->if_capenable & IFCAP_RXCSUM) {
1775 m->m_pkthdr.csum_flags |=
1776 CSUM_IP_CHECKED | CSUM_IP_VALID |
1777 CSUM_DATA_VALID | CSUM_SCTP_VALID |
1778 CSUM_PSEUDO_HDR;
1779 m->m_pkthdr.csum_data = 0xffff;
1780 }
1781 break;
1782 #endif
1783 #ifdef INET6
1784 case ETHERTYPE_IPV6:
1785 if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) {
1786 m->m_pkthdr.csum_flags |=
1787 CSUM_DATA_VALID_IPV6 | CSUM_SCTP_VALID |
1788 CSUM_PSEUDO_HDR;
1789 m->m_pkthdr.csum_data = 0xffff;
1790 }
1791 break;
1792 #endif
1793 }
1794 }
1795
1796 /* Pass packet up to parent. */
1797 CURVNET_SET(ifp->if_vnet);
1798 NET_EPOCH_ENTER(et);
1799 #if defined(INET) || defined(INET6)
1800 if (tp->tun_lro_ready && ifp->if_capenable & IFCAP_LRO &&
1801 tcp_lro_rx(&tp->tun_lro, m, 0) == 0)
1802 tcp_lro_flush_all(&tp->tun_lro);
1803 else
1804 #endif
1805 (*ifp->if_input)(ifp, m);
1806 NET_EPOCH_EXIT(et);
1807 CURVNET_RESTORE();
1808 /* ibytes are counted in parent */
1809 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1810 return (0);
1811 }
1812
1813 static int
tunwrite_l3(struct tuntap_softc * tp,struct mbuf * m)1814 tunwrite_l3(struct tuntap_softc *tp, struct mbuf *m)
1815 {
1816 struct epoch_tracker et;
1817 struct ifnet *ifp;
1818 int family, isr;
1819
1820 ifp = TUN2IFP(tp);
1821 /* Could be unlocked read? */
1822 TUN_LOCK(tp);
1823 if (tp->tun_flags & TUN_IFHEAD) {
1824 TUN_UNLOCK(tp);
1825 if (m->m_len < sizeof(family) &&
1826 (m = m_pullup(m, sizeof(family))) == NULL)
1827 return (ENOBUFS);
1828 family = ntohl(*mtod(m, u_int32_t *));
1829 m_adj(m, sizeof(family));
1830 } else {
1831 TUN_UNLOCK(tp);
1832 family = AF_INET;
1833 }
1834
1835 BPF_MTAP2(ifp, &family, sizeof(family), m);
1836
1837 switch (family) {
1838 #ifdef INET
1839 case AF_INET:
1840 isr = NETISR_IP;
1841 break;
1842 #endif
1843 #ifdef INET6
1844 case AF_INET6:
1845 isr = NETISR_IPV6;
1846 break;
1847 #endif
1848 default:
1849 m_freem(m);
1850 return (EAFNOSUPPORT);
1851 }
1852 random_harvest_queue(m, sizeof(*m), RANDOM_NET_TUN);
1853 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
1854 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1855 CURVNET_SET(ifp->if_vnet);
1856 M_SETFIB(m, ifp->if_fib);
1857 NET_EPOCH_ENTER(et);
1858 netisr_dispatch(isr, m);
1859 NET_EPOCH_EXIT(et);
1860 CURVNET_RESTORE();
1861 return (0);
1862 }
1863
1864 /*
1865 * the cdevsw write interface - an atomic write is a packet - or else!
1866 */
1867 static int
tunwrite(struct cdev * dev,struct uio * uio,int flag)1868 tunwrite(struct cdev *dev, struct uio *uio, int flag)
1869 {
1870 struct virtio_net_hdr_mrg_rxbuf vhdr;
1871 struct tuntap_softc *tp;
1872 struct ifnet *ifp;
1873 struct mbuf *m;
1874 uint32_t mru;
1875 int align, vhdrlen, error;
1876 bool l2tun;
1877
1878 tp = dev->si_drv1;
1879 ifp = TUN2IFP(tp);
1880 TUNDEBUG(ifp, "tunwrite\n");
1881 if ((ifp->if_flags & IFF_UP) != IFF_UP)
1882 /* ignore silently */
1883 return (0);
1884
1885 if (uio->uio_resid == 0)
1886 return (0);
1887
1888 l2tun = (tp->tun_flags & TUN_L2) != 0;
1889 mru = l2tun ? TAPMRU : TUNMRU;
1890 vhdrlen = tp->tun_vhdrlen;
1891 align = 0;
1892 if (l2tun) {
1893 align = ETHER_ALIGN;
1894 mru += vhdrlen;
1895 } else if ((tp->tun_flags & TUN_IFHEAD) != 0)
1896 mru += sizeof(uint32_t); /* family */
1897 if (uio->uio_resid < 0 || uio->uio_resid > mru) {
1898 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid);
1899 return (EIO);
1900 }
1901
1902 if (vhdrlen > 0) {
1903 error = uiomove(&vhdr, vhdrlen, uio);
1904 if (error != 0)
1905 return (error);
1906 TUNDEBUG(ifp, "txvhdr: f %u, gt %u, hl %u, "
1907 "gs %u, cs %u, co %u\n", vhdr.hdr.flags,
1908 vhdr.hdr.gso_type, vhdr.hdr.hdr_len,
1909 vhdr.hdr.gso_size, vhdr.hdr.csum_start,
1910 vhdr.hdr.csum_offset);
1911 }
1912
1913 if ((m = m_uiotombuf(uio, M_NOWAIT, 0, align, M_PKTHDR)) == NULL) {
1914 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
1915 return (ENOBUFS);
1916 }
1917
1918 m->m_pkthdr.rcvif = ifp;
1919 #ifdef MAC
1920 mac_ifnet_create_mbuf(ifp, m);
1921 #endif
1922
1923 if (l2tun)
1924 return (tunwrite_l2(tp, m, vhdrlen > 0 ? &vhdr : NULL));
1925
1926 return (tunwrite_l3(tp, m));
1927 }
1928
1929 /*
1930 * tunpoll - the poll interface, this is only useful on reads
1931 * really. The write detect always returns true, write never blocks
1932 * anyway, it either accepts the packet or drops it.
1933 */
1934 static int
tunpoll(struct cdev * dev,int events,struct thread * td)1935 tunpoll(struct cdev *dev, int events, struct thread *td)
1936 {
1937 struct tuntap_softc *tp = dev->si_drv1;
1938 struct ifnet *ifp = TUN2IFP(tp);
1939 int revents = 0;
1940
1941 TUNDEBUG(ifp, "tunpoll\n");
1942
1943 if (events & (POLLIN | POLLRDNORM)) {
1944 IFQ_LOCK(&ifp->if_snd);
1945 if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
1946 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len);
1947 revents |= events & (POLLIN | POLLRDNORM);
1948 } else {
1949 TUNDEBUG(ifp, "tunpoll waiting\n");
1950 selrecord(td, &tp->tun_rsel);
1951 }
1952 IFQ_UNLOCK(&ifp->if_snd);
1953 }
1954 revents |= events & (POLLOUT | POLLWRNORM);
1955
1956 return (revents);
1957 }
1958
1959 /*
1960 * tunkqfilter - support for the kevent() system call.
1961 */
1962 static int
tunkqfilter(struct cdev * dev,struct knote * kn)1963 tunkqfilter(struct cdev *dev, struct knote *kn)
1964 {
1965 struct tuntap_softc *tp = dev->si_drv1;
1966 struct ifnet *ifp = TUN2IFP(tp);
1967
1968 switch(kn->kn_filter) {
1969 case EVFILT_READ:
1970 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n",
1971 ifp->if_xname, dev2unit(dev));
1972 kn->kn_fop = &tun_read_filterops;
1973 break;
1974
1975 case EVFILT_WRITE:
1976 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n",
1977 ifp->if_xname, dev2unit(dev));
1978 kn->kn_fop = &tun_write_filterops;
1979 break;
1980
1981 default:
1982 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n",
1983 ifp->if_xname, dev2unit(dev));
1984 return(EINVAL);
1985 }
1986
1987 kn->kn_hook = tp;
1988 knlist_add(&tp->tun_rsel.si_note, kn, 0);
1989
1990 return (0);
1991 }
1992
1993 /*
1994 * Return true of there is data in the interface queue.
1995 */
1996 static int
tunkqread(struct knote * kn,long hint)1997 tunkqread(struct knote *kn, long hint)
1998 {
1999 int ret;
2000 struct tuntap_softc *tp = kn->kn_hook;
2001 struct cdev *dev = tp->tun_dev;
2002 struct ifnet *ifp = TUN2IFP(tp);
2003
2004 if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) {
2005 TUNDEBUG(ifp,
2006 "%s have data in the queue. Len = %d, minor = %#x\n",
2007 ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev));
2008 ret = 1;
2009 } else {
2010 TUNDEBUG(ifp,
2011 "%s waiting for data, minor = %#x\n", ifp->if_xname,
2012 dev2unit(dev));
2013 ret = 0;
2014 }
2015
2016 return (ret);
2017 }
2018
2019 /*
2020 * Always can write, always return MTU in kn->data.
2021 */
2022 static int
tunkqwrite(struct knote * kn,long hint)2023 tunkqwrite(struct knote *kn, long hint)
2024 {
2025 struct tuntap_softc *tp = kn->kn_hook;
2026 struct ifnet *ifp = TUN2IFP(tp);
2027
2028 kn->kn_data = ifp->if_mtu;
2029
2030 return (1);
2031 }
2032
2033 static void
tunkqdetach(struct knote * kn)2034 tunkqdetach(struct knote *kn)
2035 {
2036 struct tuntap_softc *tp = kn->kn_hook;
2037
2038 knlist_remove(&tp->tun_rsel.si_note, kn, 0);
2039 }
2040