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 #include <sys/osd.h>
78
79 #include <net/ethernet.h>
80 #include <net/if.h>
81 #include <net/if_var.h>
82 #include <net/if_clone.h>
83 #include <net/if_dl.h>
84 #include <net/if_media.h>
85 #include <net/if_private.h>
86 #include <net/if_types.h>
87 #include <net/if_vlan_var.h>
88 #include <net/netisr.h>
89 #include <net/route.h>
90 #include <net/vnet.h>
91 #include <netinet/in.h>
92 #ifdef INET
93 #include <netinet/ip.h>
94 #endif
95 #ifdef INET6
96 #include <netinet/ip6.h>
97 #include <netinet6/ip6_var.h>
98 #endif
99 #include <netinet/udp.h>
100 #include <netinet/tcp.h>
101 #include <netinet/tcp_lro.h>
102 #include <net/bpf.h>
103 #include <net/if_tap.h>
104 #include <net/if_tun.h>
105
106 #include <dev/virtio/network/virtio_net.h>
107
108 #include <sys/queue.h>
109 #include <sys/condvar.h>
110 #include <security/mac/mac_framework.h>
111
112 struct tuntap_driver;
113
114 /*
115 * tun_list is protected by global tunmtx. Other mutable fields are
116 * protected by tun->tun_mtx, or by their owning subsystem. tun_dev is
117 * static for the duration of a tunnel interface.
118 */
119 struct tuntap_softc {
120 TAILQ_ENTRY(tuntap_softc) tun_list;
121 struct cdev *tun_alias;
122 struct cdev *tun_dev;
123 u_short tun_flags; /* misc flags */
124 #define TUN_OPEN 0x0001
125 #define TUN_INITED 0x0002
126 #define TUN_UNUSED1 0x0008
127 #define TUN_UNUSED2 0x0010
128 #define TUN_LMODE 0x0020
129 #define TUN_RWAIT 0x0040
130 #define TUN_ASYNC 0x0080
131 #define TUN_IFHEAD 0x0100
132 #define TUN_DYING 0x0200
133 #define TUN_L2 0x0400
134 #define TUN_VMNET 0x0800
135 #define TUN_TRANSIENT 0x1000
136
137 #define TUN_DRIVER_IDENT_MASK (TUN_L2 | TUN_VMNET)
138 #define TUN_READY (TUN_OPEN | TUN_INITED)
139
140 pid_t tun_pid; /* owning pid */
141 struct ifnet *tun_ifp; /* the interface */
142 struct sigio *tun_sigio; /* async I/O info */
143 struct tuntap_driver *tun_drv; /* appropriate driver */
144 struct selinfo tun_rsel; /* read select */
145 struct mtx tun_mtx; /* softc field mutex */
146 struct cv tun_cv; /* for ref'd dev destroy */
147 struct ether_addr tun_ether; /* remote address */
148 int tun_busy; /* busy count */
149 int tun_vhdrlen; /* virtio-net header length */
150 struct lro_ctrl tun_lro; /* for TCP LRO */
151 bool tun_lro_ready; /* TCP LRO initialized */
152 };
153 #define TUN2IFP(sc) ((sc)->tun_ifp)
154
155 #define TUNDEBUG if (tundebug) if_printf
156
157 #define TUN_LOCK(tp) mtx_lock(&(tp)->tun_mtx)
158 #define TUN_UNLOCK(tp) mtx_unlock(&(tp)->tun_mtx)
159 #define TUN_LOCK_ASSERT(tp) mtx_assert(&(tp)->tun_mtx, MA_OWNED);
160
161 #define TUN_VMIO_FLAG_MASK 0x0fff
162
163 /*
164 * Interface capabilities of a tap device that supports the virtio-net
165 * header.
166 */
167 #define TAP_VNET_HDR_CAPS (IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6 \
168 | IFCAP_VLAN_HWCSUM \
169 | IFCAP_TSO | IFCAP_LRO \
170 | IFCAP_VLAN_HWTSO)
171
172 #define TAP_ALL_OFFLOAD (CSUM_TSO | CSUM_TCP | CSUM_UDP |\
173 CSUM_TCP_IPV6 | CSUM_UDP_IPV6)
174
175 /*
176 * All mutable global variables in if_tun are locked using tunmtx, with
177 * the exception of tundebug, which is used unlocked, and the drivers' *clones,
178 * which are static after setup.
179 */
180 static struct mtx tunmtx;
181 static eventhandler_tag arrival_tag;
182 static eventhandler_tag clone_tag;
183 static int tuntap_osd_jail_slot;
184 static const char tunname[] = "tun";
185 static const char tapname[] = "tap";
186 static const char vmnetname[] = "vmnet";
187 static MALLOC_DEFINE(M_TUN, tunname, "Tunnel Interface");
188 static int tundebug = 0;
189 static int tundclone = 1;
190 static int tap_allow_uopen = 0; /* allow user devfs cloning */
191 static int tapuponopen = 0; /* IFF_UP on open() */
192 static int tapdclone = 1; /* enable devfs cloning */
193
194 static TAILQ_HEAD(,tuntap_softc) tunhead = TAILQ_HEAD_INITIALIZER(tunhead);
195 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");
196
197 static struct sx tun_ioctl_sx;
198 SX_SYSINIT(tun_ioctl_sx, &tun_ioctl_sx, "tun_ioctl");
199
200 SYSCTL_DECL(_net_link);
201 /* tun */
202 static SYSCTL_NODE(_net_link, OID_AUTO, tun, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
203 "IP tunnel software network interface");
204 SYSCTL_INT(_net_link_tun, OID_AUTO, devfs_cloning, CTLFLAG_RWTUN, &tundclone, 0,
205 "Enable legacy devfs interface creation");
206
207 /* tap */
208 static SYSCTL_NODE(_net_link, OID_AUTO, tap, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
209 "Ethernet tunnel software network interface");
210 SYSCTL_INT(_net_link_tap, OID_AUTO, user_open, CTLFLAG_RW, &tap_allow_uopen, 0,
211 "Enable legacy devfs interface creation for all users");
212 SYSCTL_INT(_net_link_tap, OID_AUTO, up_on_open, CTLFLAG_RW, &tapuponopen, 0,
213 "Bring interface up when /dev/tap is opened");
214 SYSCTL_INT(_net_link_tap, OID_AUTO, devfs_cloning, CTLFLAG_RWTUN, &tapdclone, 0,
215 "Enable legacy devfs interface creation");
216 SYSCTL_INT(_net_link_tap, OID_AUTO, debug, CTLFLAG_RW, &tundebug, 0, "");
217
218 static int tun_create_device(struct tuntap_driver *drv, int unit,
219 struct ucred *cr, struct cdev **dev, const char *name);
220 static int tun_busy_locked(struct tuntap_softc *tp);
221 static void tun_unbusy_locked(struct tuntap_softc *tp);
222 static int tun_busy(struct tuntap_softc *tp);
223 static void tun_unbusy(struct tuntap_softc *tp);
224
225 static int tuntap_name2info(const char *name, int *unit, int *flags);
226 static void tunclone(void *arg, struct ucred *cred, char *name,
227 int namelen, struct cdev **dev);
228 static void tuncreate(struct cdev *dev);
229 static void tundtor(void *data);
230 static void tunrename(void *arg, struct ifnet *ifp);
231 static int tunifioctl(struct ifnet *, u_long, caddr_t);
232 static void tuninit(struct ifnet *);
233 static void tunifinit(void *xtp);
234 static int tuntapmodevent(module_t, int, void *);
235 static int tunoutput(struct ifnet *, struct mbuf *,
236 const struct sockaddr *, struct route *ro);
237 static void tunstart(struct ifnet *);
238 static void tunstart_l2(struct ifnet *);
239
240 static int tun_clone_match(struct if_clone *ifc, const char *name);
241 static int tap_clone_match(struct if_clone *ifc, const char *name);
242 static int vmnet_clone_match(struct if_clone *ifc, const char *name);
243 static int tun_clone_create(struct if_clone *, char *, size_t,
244 struct ifc_data *, struct ifnet **);
245 static int tun_clone_destroy(struct if_clone *, struct ifnet *, uint32_t);
246 static void tun_vnethdr_set(struct ifnet *ifp, int vhdrlen);
247
248 static d_open_t tunopen;
249 static d_read_t tunread;
250 static d_write_t tunwrite;
251 static d_ioctl_t tunioctl;
252 static d_poll_t tunpoll;
253 static d_kqfilter_t tunkqfilter;
254
255 static int tunkqread(struct knote *, long);
256 static int tunkqwrite(struct knote *, long);
257 static void tunkqdetach(struct knote *);
258
259 static const struct filterops tun_read_filterops = {
260 .f_isfd = 1,
261 .f_attach = NULL,
262 .f_detach = tunkqdetach,
263 .f_event = tunkqread,
264 .f_copy = knote_triv_copy,
265 };
266
267 static const struct filterops tun_write_filterops = {
268 .f_isfd = 1,
269 .f_attach = NULL,
270 .f_detach = tunkqdetach,
271 .f_event = tunkqwrite,
272 .f_copy = knote_triv_copy,
273 };
274
275 static struct tuntap_driver {
276 struct cdevsw cdevsw;
277 int ident_flags;
278 struct unrhdr *unrhdr;
279 struct clonedevs *clones;
280 ifc_match_f *clone_match_fn;
281 ifc_create_f *clone_create_fn;
282 ifc_destroy_f *clone_destroy_fn;
283 } tuntap_drivers[] = {
284 {
285 .ident_flags = 0,
286 .cdevsw = {
287 .d_version = D_VERSION,
288 .d_flags = D_NEEDMINOR,
289 .d_open = tunopen,
290 .d_read = tunread,
291 .d_write = tunwrite,
292 .d_ioctl = tunioctl,
293 .d_poll = tunpoll,
294 .d_kqfilter = tunkqfilter,
295 .d_name = tunname,
296 },
297 .clone_match_fn = tun_clone_match,
298 .clone_create_fn = tun_clone_create,
299 .clone_destroy_fn = tun_clone_destroy,
300 },
301 {
302 .ident_flags = TUN_L2,
303 .cdevsw = {
304 .d_version = D_VERSION,
305 .d_flags = D_NEEDMINOR,
306 .d_open = tunopen,
307 .d_read = tunread,
308 .d_write = tunwrite,
309 .d_ioctl = tunioctl,
310 .d_poll = tunpoll,
311 .d_kqfilter = tunkqfilter,
312 .d_name = tapname,
313 },
314 .clone_match_fn = tap_clone_match,
315 .clone_create_fn = tun_clone_create,
316 .clone_destroy_fn = tun_clone_destroy,
317 },
318 {
319 .ident_flags = TUN_L2 | TUN_VMNET,
320 .cdevsw = {
321 .d_version = D_VERSION,
322 .d_flags = D_NEEDMINOR,
323 .d_open = tunopen,
324 .d_read = tunread,
325 .d_write = tunwrite,
326 .d_ioctl = tunioctl,
327 .d_poll = tunpoll,
328 .d_kqfilter = tunkqfilter,
329 .d_name = vmnetname,
330 },
331 .clone_match_fn = vmnet_clone_match,
332 .clone_create_fn = tun_clone_create,
333 .clone_destroy_fn = tun_clone_destroy,
334 },
335 };
336 #define NDRV nitems(tuntap_drivers)
337
338 VNET_DEFINE_STATIC(struct if_clone *, tuntap_driver_cloners[NDRV]);
339 #define V_tuntap_driver_cloners VNET(tuntap_driver_cloners)
340
341 /*
342 * Mechanism for marking a tunnel device as busy so that we can safely do some
343 * orthogonal operations (such as operations on devices) without racing against
344 * tun_destroy. tun_destroy will wait on the condvar if we're at all busy or
345 * open, to be woken up when the condition is alleviated.
346 */
347 static int
tun_busy_locked(struct tuntap_softc * tp)348 tun_busy_locked(struct tuntap_softc *tp)
349 {
350
351 TUN_LOCK_ASSERT(tp);
352 if ((tp->tun_flags & TUN_DYING) != 0) {
353 /*
354 * Perhaps unintuitive, but the device is busy going away.
355 * Other interpretations of EBUSY from tun_busy make little
356 * sense, since making a busy device even more busy doesn't
357 * sound like a problem.
358 */
359 return (EBUSY);
360 }
361
362 ++tp->tun_busy;
363 return (0);
364 }
365
366 static void
tun_unbusy_locked(struct tuntap_softc * tp)367 tun_unbusy_locked(struct tuntap_softc *tp)
368 {
369
370 TUN_LOCK_ASSERT(tp);
371 KASSERT(tp->tun_busy != 0, ("tun_unbusy: called for non-busy tunnel"));
372
373 --tp->tun_busy;
374 /* Wake up anything that may be waiting on our busy tunnel. */
375 if (tp->tun_busy == 0)
376 cv_broadcast(&tp->tun_cv);
377 }
378
379 static int
tun_busy(struct tuntap_softc * tp)380 tun_busy(struct tuntap_softc *tp)
381 {
382 int ret;
383
384 TUN_LOCK(tp);
385 ret = tun_busy_locked(tp);
386 TUN_UNLOCK(tp);
387 return (ret);
388 }
389
390 static void
tun_unbusy(struct tuntap_softc * tp)391 tun_unbusy(struct tuntap_softc *tp)
392 {
393
394 TUN_LOCK(tp);
395 tun_unbusy_locked(tp);
396 TUN_UNLOCK(tp);
397 }
398
399 /*
400 * Sets unit and/or flags given the device name. Must be called with correct
401 * vnet context.
402 */
403 static int
tuntap_name2info(const char * name,int * outunit,int * outflags)404 tuntap_name2info(const char *name, int *outunit, int *outflags)
405 {
406 struct tuntap_driver *drv;
407 char *dname;
408 int flags, unit;
409 bool found;
410
411 if (name == NULL)
412 return (EINVAL);
413
414 /*
415 * Needed for dev_stdclone, but dev_stdclone will not modify, it just
416 * wants to be able to pass back a char * through the second param. We
417 * will always set that as NULL here, so we'll fake it.
418 */
419 dname = __DECONST(char *, name);
420 found = false;
421
422 for (u_int i = 0; i < NDRV; i++) {
423 drv = &tuntap_drivers[i];
424
425 if (strcmp(name, drv->cdevsw.d_name) == 0) {
426 found = true;
427 unit = -1;
428 flags = drv->ident_flags;
429 break;
430 }
431
432 if (dev_stdclone(dname, NULL, drv->cdevsw.d_name, &unit) == 1) {
433 found = true;
434 flags = drv->ident_flags;
435 break;
436 }
437 }
438
439 if (!found)
440 return (ENXIO);
441
442 if (outunit != NULL)
443 *outunit = unit;
444 if (outflags != NULL)
445 *outflags = flags;
446 return (0);
447 }
448
449 static struct if_clone *
tuntap_cloner_from_flags(int tun_flags)450 tuntap_cloner_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 (V_tuntap_driver_cloners[i]);
457
458 return (NULL);
459 }
460
461 /*
462 * Get driver information from a set of flags specified. Masks the identifying
463 * part of the flags and compares it against all of the available
464 * tuntap_drivers.
465 */
466 static struct tuntap_driver *
tuntap_driver_from_flags(int tun_flags)467 tuntap_driver_from_flags(int tun_flags)
468 {
469
470 for (u_int i = 0; i < NDRV; i++)
471 if ((tun_flags & TUN_DRIVER_IDENT_MASK) ==
472 tuntap_drivers[i].ident_flags)
473 return (&tuntap_drivers[i]);
474
475 return (NULL);
476 }
477
478 static int
tun_clone_match(struct if_clone * ifc,const char * name)479 tun_clone_match(struct if_clone *ifc, const char *name)
480 {
481 int tunflags;
482
483 if (tuntap_name2info(name, NULL, &tunflags) == 0) {
484 if ((tunflags & TUN_L2) == 0)
485 return (1);
486 }
487
488 return (0);
489 }
490
491 static int
tap_clone_match(struct if_clone * ifc,const char * name)492 tap_clone_match(struct if_clone *ifc, const char *name)
493 {
494 int tunflags;
495
496 if (tuntap_name2info(name, NULL, &tunflags) == 0) {
497 if ((tunflags & (TUN_L2 | TUN_VMNET)) == TUN_L2)
498 return (1);
499 }
500
501 return (0);
502 }
503
504 static int
vmnet_clone_match(struct if_clone * ifc,const char * name)505 vmnet_clone_match(struct if_clone *ifc, const char *name)
506 {
507 int tunflags;
508
509 if (tuntap_name2info(name, NULL, &tunflags) == 0) {
510 if ((tunflags & TUN_VMNET) != 0)
511 return (1);
512 }
513
514 return (0);
515 }
516
517 /*
518 * Create a clone via the ifnet cloning mechanism. Note that this is invoked
519 * indirectly by tunclone() below.
520 */
521 static int
tun_clone_create(struct if_clone * ifc,char * name,size_t len,struct ifc_data * ifd,struct ifnet ** ifpp)522 tun_clone_create(struct if_clone *ifc, char *name, size_t len,
523 struct ifc_data *ifd, struct ifnet **ifpp)
524 {
525 struct tuntap_driver *drv;
526 struct cdev *dev;
527 int err, i, tunflags, unit;
528
529 tunflags = 0;
530 /* The name here tells us exactly what we're creating */
531 err = tuntap_name2info(name, &unit, &tunflags);
532 if (err != 0)
533 return (err);
534
535 drv = tuntap_driver_from_flags(tunflags);
536 if (drv == NULL)
537 return (ENXIO);
538
539 if (unit != -1) {
540 /* If this unit number is still available that's okay. */
541 if (alloc_unr_specific(drv->unrhdr, unit) == -1)
542 return (EEXIST);
543 } else {
544 unit = alloc_unr(drv->unrhdr);
545 }
546
547 snprintf(name, IFNAMSIZ, "%s%d", drv->cdevsw.d_name, unit);
548
549 /* find any existing device, or allocate new unit number */
550 dev = NULL;
551 i = clone_create(&drv->clones, &drv->cdevsw, &unit, &dev, 0);
552 /* No preexisting struct cdev *, create one */
553 if (i != 0)
554 i = tun_create_device(drv, unit, NULL, &dev, name);
555 if (i == 0) {
556 struct tuntap_softc *tp;
557
558 tuncreate(dev);
559 tp = dev->si_drv1;
560 *ifpp = tp->tun_ifp;
561 }
562
563 return (i);
564 }
565
566 /*
567 * Create a clone via devfs access.
568 */
569 static void
tunclone(void * arg,struct ucred * cred,char * name,int namelen,struct cdev ** dev)570 tunclone(void *arg, struct ucred *cred, char *name, int namelen,
571 struct cdev **dev)
572 {
573 char devname[SPECNAMELEN + 1];
574 struct tuntap_driver *drv;
575 int append_unit, i, u, tunflags;
576 bool mayclone;
577
578 if (*dev != NULL)
579 return;
580
581 tunflags = 0;
582 CURVNET_SET(CRED_TO_VNET(cred));
583 if (tuntap_name2info(name, &u, &tunflags) != 0)
584 goto out; /* Not recognized */
585
586 if (u != -1 && u > IF_MAXUNIT)
587 goto out; /* Unit number too high */
588
589 mayclone = priv_check_cred(cred, PRIV_NET_IFCREATE) == 0;
590 if ((tunflags & TUN_L2) != 0) {
591 /* tap/vmnet allow user open with a sysctl */
592 mayclone = (mayclone || tap_allow_uopen) && tapdclone;
593 } else {
594 mayclone = mayclone && tundclone;
595 }
596
597 /*
598 * If tun cloning is enabled, only the superuser can create an
599 * interface.
600 */
601 if (!mayclone)
602 goto out;
603
604 if (u == -1)
605 append_unit = 1;
606 else
607 append_unit = 0;
608
609 drv = tuntap_driver_from_flags(tunflags);
610 if (drv == NULL)
611 goto out;
612
613 /* find any existing device, or allocate new unit number */
614 i = clone_create(&drv->clones, &drv->cdevsw, &u, dev, 0);
615 if (i) {
616 if (append_unit) {
617 namelen = snprintf(devname, sizeof(devname), "%s%d",
618 name, u);
619 name = devname;
620 }
621
622 i = tun_create_device(drv, u, cred, dev, name);
623 } else {
624 /* Consumed by the dev_clone invoker. */
625 dev_ref(*dev);
626 }
627 if (i == 0)
628 if_clone_create(name, namelen, NULL);
629 out:
630 CURVNET_RESTORE();
631 }
632
633 static int
tun_destroy(struct tuntap_softc * tp,bool may_intr)634 tun_destroy(struct tuntap_softc *tp, bool may_intr)
635 {
636 int error;
637
638 TUN_LOCK(tp);
639
640 /*
641 * Transient tunnels may have set TUN_DYING if we're being destroyed as
642 * a result of the last close, which we'll allow.
643 */
644 MPASS((tp->tun_flags & (TUN_DYING | TUN_TRANSIENT)) != TUN_DYING);
645 tp->tun_flags |= TUN_DYING;
646 error = 0;
647 while (tp->tun_busy != 0) {
648 if (may_intr)
649 error = cv_wait_sig(&tp->tun_cv, &tp->tun_mtx);
650 else
651 cv_wait(&tp->tun_cv, &tp->tun_mtx);
652 if (error != 0) {
653 tp->tun_flags &= ~TUN_DYING;
654 TUN_UNLOCK(tp);
655 return (error);
656 }
657 }
658 TUN_UNLOCK(tp);
659
660 CURVNET_SET(TUN2IFP(tp)->if_vnet);
661
662 mtx_lock(&tunmtx);
663 TAILQ_REMOVE(&tunhead, tp, tun_list);
664 mtx_unlock(&tunmtx);
665
666 /* destroy_dev will take care of any alias. */
667 destroy_dev(tp->tun_dev);
668 seldrain(&tp->tun_rsel);
669 knlist_clear(&tp->tun_rsel.si_note, 0);
670 knlist_destroy(&tp->tun_rsel.si_note);
671 if ((tp->tun_flags & TUN_L2) != 0) {
672 ether_ifdetach(TUN2IFP(tp));
673 } else {
674 bpfdetach(TUN2IFP(tp));
675 if_detach(TUN2IFP(tp));
676 }
677 sx_xlock(&tun_ioctl_sx);
678 TUN2IFP(tp)->if_softc = NULL;
679 sx_xunlock(&tun_ioctl_sx);
680 free_unr(tp->tun_drv->unrhdr, TUN2IFP(tp)->if_dunit);
681 if_free(TUN2IFP(tp));
682 mtx_destroy(&tp->tun_mtx);
683 cv_destroy(&tp->tun_cv);
684 free(tp, M_TUN);
685 CURVNET_RESTORE();
686
687 return (0);
688 }
689
690 static int
tun_clone_destroy(struct if_clone * ifc __unused,struct ifnet * ifp,uint32_t flags)691 tun_clone_destroy(struct if_clone *ifc __unused, struct ifnet *ifp, uint32_t flags)
692 {
693 struct tuntap_softc *tp = ifp->if_softc;
694
695 return (tun_destroy(tp, true));
696 }
697
698 static void
vnet_tun_init(const void * unused __unused)699 vnet_tun_init(const void *unused __unused)
700 {
701
702 for (u_int i = 0; i < NDRV; ++i) {
703 struct if_clone_addreq req = {
704 .match_f = tuntap_drivers[i].clone_match_fn,
705 .create_f = tuntap_drivers[i].clone_create_fn,
706 .destroy_f = tuntap_drivers[i].clone_destroy_fn,
707 };
708 V_tuntap_driver_cloners[i] =
709 ifc_attach_cloner(tuntap_drivers[i].cdevsw.d_name, &req);
710 };
711 }
712 VNET_SYSINIT(vnet_tun_init, SI_SUB_PROTO_IF, SI_ORDER_ANY,
713 vnet_tun_init, NULL);
714
715 static void
tun_uninit(const void * unused __unused)716 tun_uninit(const void *unused __unused)
717 {
718 struct tuntap_driver *drv;
719 struct tuntap_softc *tp;
720 int i;
721
722 EVENTHANDLER_DEREGISTER(ifnet_arrival_event, arrival_tag);
723 EVENTHANDLER_DEREGISTER(dev_clone, clone_tag);
724
725 CURVNET_SET(vnet0);
726 for (u_int i = 0; i < NDRV; i++) {
727 if_clone_detach(V_tuntap_driver_cloners[i]);
728 V_tuntap_driver_cloners[i] = NULL;
729 }
730 CURVNET_RESTORE();
731
732 if (tuntap_osd_jail_slot != 0)
733 osd_jail_deregister(tuntap_osd_jail_slot);
734
735 mtx_lock(&tunmtx);
736 while ((tp = TAILQ_FIRST(&tunhead)) != NULL) {
737 mtx_unlock(&tunmtx);
738 /* tun_destroy() will remove it from the tailq. */
739 tun_destroy(tp, false);
740 mtx_lock(&tunmtx);
741 }
742 mtx_unlock(&tunmtx);
743 for (i = 0; i < nitems(tuntap_drivers); ++i) {
744 drv = &tuntap_drivers[i];
745 delete_unrhdr(drv->unrhdr);
746 clone_cleanup(&drv->clones);
747 }
748 mtx_destroy(&tunmtx);
749 }
750 SYSUNINIT(tun_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY, tun_uninit, NULL);
751
752 static struct tuntap_driver *
tuntap_driver_from_ifnet(const struct ifnet * ifp)753 tuntap_driver_from_ifnet(const struct ifnet *ifp)
754 {
755 struct tuntap_driver *drv;
756 int i;
757
758 if (ifp == NULL)
759 return (NULL);
760
761 for (i = 0; i < nitems(tuntap_drivers); ++i) {
762 drv = &tuntap_drivers[i];
763 if (strcmp(ifp->if_dname, drv->cdevsw.d_name) == 0)
764 return (drv);
765 }
766
767 return (NULL);
768 }
769
770 /*
771 * Remove devices that were created by devfs cloning, as they hold references
772 * which prevent the prison from collapsing, in which state VNET sysuninits will
773 * not be invoked.
774 */
775 static int
tuntap_prison_remove(void * obj,void * data __unused)776 tuntap_prison_remove(void *obj, void *data __unused)
777 {
778 #ifdef VIMAGE
779 struct prison *pr;
780
781 pr = obj;
782 if (prison_owns_vnet(pr)) {
783 CURVNET_SET(pr->pr_vnet);
784 for (u_int i = 0; i < NDRV; i++) {
785 if_clone_detach(V_tuntap_driver_cloners[i]);
786 V_tuntap_driver_cloners[i] = NULL;
787 }
788 CURVNET_RESTORE();
789 }
790 #endif
791 return (0);
792 }
793
794 static int
tuntapmodevent(module_t mod,int type,void * data)795 tuntapmodevent(module_t mod, int type, void *data)
796 {
797 struct tuntap_driver *drv;
798 int i;
799
800 switch (type) {
801 case MOD_LOAD:
802 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF);
803 for (i = 0; i < nitems(tuntap_drivers); ++i) {
804 drv = &tuntap_drivers[i];
805 clone_setup(&drv->clones);
806 drv->unrhdr = new_unrhdr(0, IF_MAXUNIT, &tunmtx);
807 }
808 osd_method_t methods[PR_MAXMETHOD] = {
809 [PR_METHOD_REMOVE] = tuntap_prison_remove,
810 };
811 tuntap_osd_jail_slot = osd_jail_register(NULL, methods);
812 arrival_tag = EVENTHANDLER_REGISTER(ifnet_arrival_event,
813 tunrename, 0, 1000);
814 if (arrival_tag == NULL)
815 return (ENOMEM);
816 clone_tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000);
817 if (clone_tag == NULL)
818 return (ENOMEM);
819 break;
820 case MOD_UNLOAD:
821 /* See tun_uninit(). */
822 break;
823 default:
824 return EOPNOTSUPP;
825 }
826 return 0;
827 }
828
829 static moduledata_t tuntap_mod = {
830 "if_tuntap",
831 tuntapmodevent,
832 0
833 };
834
835 /* We'll only ever have these two, so no need for a macro. */
836 static moduledata_t tun_mod = { "if_tun", NULL, 0 };
837 static moduledata_t tap_mod = { "if_tap", NULL, 0 };
838
839 DECLARE_MODULE(if_tuntap, tuntap_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
840 MODULE_VERSION(if_tuntap, 1);
841 DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
842 MODULE_VERSION(if_tun, 1);
843 DECLARE_MODULE(if_tap, tap_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
844 MODULE_VERSION(if_tap, 1);
845
846 static int
tun_create_device(struct tuntap_driver * drv,int unit,struct ucred * cr,struct cdev ** dev,const char * name)847 tun_create_device(struct tuntap_driver *drv, int unit, struct ucred *cr,
848 struct cdev **dev, const char *name)
849 {
850 struct make_dev_args args;
851 struct tuntap_softc *tp;
852 int error;
853
854 tp = malloc(sizeof(*tp), M_TUN, M_WAITOK | M_ZERO);
855 mtx_init(&tp->tun_mtx, "tun_mtx", NULL, MTX_DEF);
856 cv_init(&tp->tun_cv, "tun_condvar");
857 tp->tun_flags = drv->ident_flags;
858 tp->tun_drv = drv;
859
860 make_dev_args_init(&args);
861 if (cr != NULL)
862 args.mda_flags = MAKEDEV_REF | MAKEDEV_CHECKNAME;
863 args.mda_devsw = &drv->cdevsw;
864 args.mda_cr = cr;
865 args.mda_uid = UID_UUCP;
866 args.mda_gid = GID_DIALER;
867 args.mda_mode = 0600;
868 args.mda_unit = unit;
869 args.mda_si_drv1 = tp;
870 error = make_dev_s(&args, dev, "%s", name);
871 if (error != 0) {
872 mtx_destroy(&tp->tun_mtx);
873 cv_destroy(&tp->tun_cv);
874 free(tp, M_TUN);
875 return (error);
876 }
877
878 KASSERT((*dev)->si_drv1 != NULL,
879 ("Failed to set si_drv1 at %s creation", name));
880 tp->tun_dev = *dev;
881 knlist_init_mtx(&tp->tun_rsel.si_note, &tp->tun_mtx);
882 mtx_lock(&tunmtx);
883 TAILQ_INSERT_TAIL(&tunhead, tp, tun_list);
884 mtx_unlock(&tunmtx);
885 return (0);
886 }
887
888 static void
tunstart(struct ifnet * ifp)889 tunstart(struct ifnet *ifp)
890 {
891 struct tuntap_softc *tp = ifp->if_softc;
892 struct mbuf *m;
893
894 TUNDEBUG(ifp, "starting\n");
895 if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
896 IFQ_LOCK(&ifp->if_snd);
897 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
898 if (m == NULL) {
899 IFQ_UNLOCK(&ifp->if_snd);
900 return;
901 }
902 IFQ_UNLOCK(&ifp->if_snd);
903 }
904
905 TUN_LOCK(tp);
906 if (tp->tun_flags & TUN_RWAIT) {
907 tp->tun_flags &= ~TUN_RWAIT;
908 wakeup(tp);
909 }
910 selwakeuppri(&tp->tun_rsel, PZERO);
911 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
912 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) {
913 TUN_UNLOCK(tp);
914 pgsigio(&tp->tun_sigio, SIGIO, 0);
915 } else
916 TUN_UNLOCK(tp);
917 }
918
919 /*
920 * tunstart_l2
921 *
922 * queue packets from higher level ready to put out
923 */
924 static void
tunstart_l2(struct ifnet * ifp)925 tunstart_l2(struct ifnet *ifp)
926 {
927 struct tuntap_softc *tp = ifp->if_softc;
928
929 TUNDEBUG(ifp, "starting\n");
930
931 /*
932 * do not junk pending output if we are in VMnet mode.
933 * XXX: can this do any harm because of queue overflow?
934 */
935
936 TUN_LOCK(tp);
937 if (((tp->tun_flags & TUN_VMNET) == 0) &&
938 ((tp->tun_flags & TUN_READY) != TUN_READY)) {
939 struct mbuf *m;
940
941 /* Unlocked read. */
942 TUNDEBUG(ifp, "not ready, tun_flags = 0x%x\n", tp->tun_flags);
943
944 for (;;) {
945 IF_DEQUEUE(&ifp->if_snd, m);
946 if (m != NULL) {
947 m_freem(m);
948 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
949 } else
950 break;
951 }
952 TUN_UNLOCK(tp);
953
954 return;
955 }
956
957 ifp->if_drv_flags |= IFF_DRV_OACTIVE;
958
959 if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
960 if (tp->tun_flags & TUN_RWAIT) {
961 tp->tun_flags &= ~TUN_RWAIT;
962 wakeup(tp);
963 }
964
965 if ((tp->tun_flags & TUN_ASYNC) && (tp->tun_sigio != NULL)) {
966 TUN_UNLOCK(tp);
967 pgsigio(&tp->tun_sigio, SIGIO, 0);
968 TUN_LOCK(tp);
969 }
970
971 selwakeuppri(&tp->tun_rsel, PZERO);
972 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
973 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); /* obytes are counted in ether_output */
974 }
975
976 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
977 TUN_UNLOCK(tp);
978 } /* tunstart_l2 */
979
980 static int
tap_transmit(struct ifnet * ifp,struct mbuf * m)981 tap_transmit(struct ifnet *ifp, struct mbuf *m)
982 {
983 int error;
984
985 BPF_MTAP(ifp, m);
986 IFQ_HANDOFF(ifp, m, error);
987 return (error);
988 }
989
990 static void
tuncreate(struct cdev * dev)991 tuncreate(struct cdev *dev)
992 {
993 struct tuntap_driver *drv;
994 struct tuntap_softc *tp;
995 struct ifnet *ifp;
996 struct ether_addr eaddr;
997 int iflags;
998 u_char type;
999
1000 tp = dev->si_drv1;
1001 KASSERT(tp != NULL,
1002 ("si_drv1 should have been initialized at creation"));
1003
1004 drv = tp->tun_drv;
1005 iflags = IFF_MULTICAST;
1006 if ((tp->tun_flags & TUN_L2) != 0) {
1007 type = IFT_ETHER;
1008 iflags |= IFF_BROADCAST | IFF_SIMPLEX;
1009 } else {
1010 type = IFT_PPP;
1011 iflags |= IFF_POINTOPOINT;
1012 }
1013 ifp = tp->tun_ifp = if_alloc(type);
1014 ifp->if_softc = tp;
1015 if_initname(ifp, drv->cdevsw.d_name, dev2unit(dev));
1016 ifp->if_ioctl = tunifioctl;
1017 ifp->if_flags = iflags;
1018 IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
1019 ifp->if_capabilities |= IFCAP_LINKSTATE | IFCAP_MEXTPG;
1020 if ((tp->tun_flags & TUN_L2) != 0)
1021 ifp->if_capabilities |=
1022 IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6 | IFCAP_LRO;
1023 ifp->if_capenable |= IFCAP_LINKSTATE | IFCAP_MEXTPG;
1024
1025 if ((tp->tun_flags & TUN_L2) != 0) {
1026 ifp->if_init = tunifinit;
1027 ifp->if_start = tunstart_l2;
1028 ifp->if_transmit = tap_transmit;
1029 ifp->if_qflush = if_qflush;
1030
1031 ether_gen_addr(ifp, &eaddr);
1032 ether_ifattach(ifp, eaddr.octet);
1033 } else {
1034 ifp->if_mtu = TUNMTU;
1035 ifp->if_start = tunstart;
1036 ifp->if_output = tunoutput;
1037
1038 ifp->if_snd.ifq_drv_maxlen = 0;
1039 IFQ_SET_READY(&ifp->if_snd);
1040
1041 if_attach(ifp);
1042 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
1043 }
1044
1045 TUN_LOCK(tp);
1046 tp->tun_flags |= TUN_INITED;
1047 TUN_UNLOCK(tp);
1048
1049 TUNDEBUG(ifp, "interface %s is created, minor = %#x\n",
1050 ifp->if_xname, dev2unit(dev));
1051 }
1052
1053 static void
tunrename(void * arg __unused,struct ifnet * ifp)1054 tunrename(void *arg __unused, struct ifnet *ifp)
1055 {
1056 struct tuntap_softc *tp;
1057 int error;
1058
1059 if ((ifp->if_flags & IFF_RENAMING) == 0)
1060 return;
1061
1062 if (tuntap_driver_from_ifnet(ifp) == NULL)
1063 return;
1064
1065 /*
1066 * We need to grab the ioctl sx long enough to make sure the softc is
1067 * still there. If it is, we can safely try to busy the tun device.
1068 * The busy may fail if the device is currently dying, in which case
1069 * we do nothing. If it doesn't fail, the busy count stops the device
1070 * from dying until we've created the alias (that will then be
1071 * subsequently destroyed).
1072 */
1073 sx_xlock(&tun_ioctl_sx);
1074 tp = ifp->if_softc;
1075 if (tp == NULL) {
1076 sx_xunlock(&tun_ioctl_sx);
1077 return;
1078 }
1079 error = tun_busy(tp);
1080 sx_xunlock(&tun_ioctl_sx);
1081 if (error != 0)
1082 return;
1083 if (tp->tun_alias != NULL) {
1084 destroy_dev(tp->tun_alias);
1085 tp->tun_alias = NULL;
1086 }
1087
1088 if (strcmp(ifp->if_xname, tp->tun_dev->si_name) == 0)
1089 goto out;
1090
1091 /*
1092 * Failure's ok, aliases are created on a best effort basis. If a
1093 * tun user/consumer decides to rename the interface to conflict with
1094 * another device (non-ifnet) on the system, we will assume they know
1095 * what they are doing. make_dev_alias_p won't touch tun_alias on
1096 * failure, so we use it but ignore the return value.
1097 */
1098 make_dev_alias_p(MAKEDEV_CHECKNAME, &tp->tun_alias, tp->tun_dev, "%s",
1099 ifp->if_xname);
1100 out:
1101 tun_unbusy(tp);
1102 }
1103
1104 static int
tunopen(struct cdev * dev,int flag,int mode,struct thread * td)1105 tunopen(struct cdev *dev, int flag, int mode, struct thread *td)
1106 {
1107 struct ifnet *ifp;
1108 struct tuntap_softc *tp;
1109 int error __diagused, tunflags;
1110
1111 tunflags = 0;
1112 CURVNET_SET(TD_TO_VNET(td));
1113 error = tuntap_name2info(dev->si_name, NULL, &tunflags);
1114 if (error != 0) {
1115 CURVNET_RESTORE();
1116 return (error); /* Shouldn't happen */
1117 }
1118
1119 tp = dev->si_drv1;
1120 KASSERT(tp != NULL,
1121 ("si_drv1 should have been initialized at creation"));
1122
1123 TUN_LOCK(tp);
1124 if ((tp->tun_flags & TUN_INITED) == 0) {
1125 TUN_UNLOCK(tp);
1126 CURVNET_RESTORE();
1127 return (ENXIO);
1128 }
1129 if ((tp->tun_flags & (TUN_OPEN | TUN_DYING)) != 0) {
1130 TUN_UNLOCK(tp);
1131 CURVNET_RESTORE();
1132 return (EBUSY);
1133 }
1134
1135 error = tun_busy_locked(tp);
1136 KASSERT(error == 0, ("Must be able to busy an unopen tunnel"));
1137 ifp = TUN2IFP(tp);
1138
1139 if ((tp->tun_flags & TUN_L2) != 0) {
1140 bcopy(IF_LLADDR(ifp), tp->tun_ether.octet,
1141 sizeof(tp->tun_ether.octet));
1142
1143 ifp->if_drv_flags |= IFF_DRV_RUNNING;
1144 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1145
1146 if (tapuponopen)
1147 ifp->if_flags |= IFF_UP;
1148 }
1149
1150 tp->tun_pid = td->td_proc->p_pid;
1151 tp->tun_flags |= TUN_OPEN;
1152
1153 if_link_state_change(ifp, LINK_STATE_UP);
1154 TUNDEBUG(ifp, "open\n");
1155 TUN_UNLOCK(tp);
1156
1157 /*
1158 * This can fail with either ENOENT or EBUSY. This is in the middle of
1159 * d_open, so ENOENT should not be possible. EBUSY is possible, but
1160 * the only cdevpriv dtor being set will be tundtor and the softc being
1161 * passed is constant for a given cdev. We ignore the possible error
1162 * because of this as either "unlikely" or "not actually a problem."
1163 */
1164 (void)devfs_set_cdevpriv(tp, tundtor);
1165 CURVNET_RESTORE();
1166 return (0);
1167 }
1168
1169 /*
1170 * tundtor - tear down the device - mark i/f down & delete
1171 * routing info
1172 */
1173 static void
tundtor(void * data)1174 tundtor(void *data)
1175 {
1176 struct proc *p;
1177 struct tuntap_softc *tp;
1178 struct ifnet *ifp;
1179 bool l2tun;
1180
1181 tp = data;
1182 p = curproc;
1183 ifp = TUN2IFP(tp);
1184
1185 TUN_LOCK(tp);
1186
1187 /*
1188 * Realistically, we can't be obstinate here. This only means that the
1189 * tuntap device was closed out of order, and the last closer wasn't the
1190 * controller. These are still good to know about, though, as software
1191 * should avoid multiple processes with a tuntap device open and
1192 * ill-defined transfer of control (e.g., handoff, TUNSIFPID, close in
1193 * parent).
1194 */
1195 if (p->p_pid != tp->tun_pid) {
1196 log(LOG_INFO,
1197 "pid %d (%s), %s: tun/tap protocol violation, non-controlling process closed last.\n",
1198 p->p_pid, p->p_comm, tp->tun_dev->si_name);
1199 }
1200
1201 /*
1202 * junk all pending output
1203 */
1204 CURVNET_SET(ifp->if_vnet);
1205
1206 l2tun = false;
1207 if ((tp->tun_flags & TUN_L2) != 0) {
1208 l2tun = true;
1209 IF_DRAIN(&ifp->if_snd);
1210 } else {
1211 IFQ_PURGE(&ifp->if_snd);
1212 }
1213
1214 /* For vmnet, we won't do most of the address/route bits */
1215 if ((tp->tun_flags & TUN_VMNET) != 0 ||
1216 (l2tun && (ifp->if_flags & IFF_LINK0) != 0))
1217 goto out;
1218 #if defined(INET) || defined(INET6)
1219 if (l2tun && tp->tun_lro_ready) {
1220 TUNDEBUG (ifp, "LRO disabled\n");
1221 tcp_lro_free(&tp->tun_lro);
1222 tp->tun_lro_ready = false;
1223 }
1224 #endif
1225 if (ifp->if_flags & IFF_UP) {
1226 TUN_UNLOCK(tp);
1227 if_down(ifp);
1228 TUN_LOCK(tp);
1229 }
1230
1231 /* Delete all addresses and routes which reference this interface. */
1232 if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
1233 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1234 TUN_UNLOCK(tp);
1235 if_purgeaddrs(ifp);
1236 TUN_LOCK(tp);
1237 }
1238
1239 out:
1240 if_link_state_change(ifp, LINK_STATE_DOWN);
1241 CURVNET_RESTORE();
1242
1243 funsetown(&tp->tun_sigio);
1244 selwakeuppri(&tp->tun_rsel, PZERO);
1245 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
1246 TUNDEBUG (ifp, "closed\n");
1247 tp->tun_flags &= ~TUN_OPEN;
1248 tp->tun_pid = 0;
1249 tun_vnethdr_set(ifp, 0);
1250
1251 tun_unbusy_locked(tp);
1252 if ((tp->tun_flags & TUN_TRANSIENT) != 0) {
1253 struct if_clone *cloner;
1254 int error __diagused;
1255
1256 /* Mark it busy so that nothing can re-open it. */
1257 tp->tun_flags |= TUN_DYING;
1258 TUN_UNLOCK(tp);
1259
1260 CURVNET_SET_QUIET(ifp->if_home_vnet);
1261 cloner = tuntap_cloner_from_flags(tp->tun_flags);
1262 CURVNET_RESTORE();
1263
1264 error = if_clone_destroyif(cloner, ifp);
1265 MPASS(error == 0 || error == EINTR || error == ERESTART);
1266 return;
1267 }
1268
1269 TUN_UNLOCK(tp);
1270 }
1271
1272 static void
tuninit(struct ifnet * ifp)1273 tuninit(struct ifnet *ifp)
1274 {
1275 struct tuntap_softc *tp = ifp->if_softc;
1276
1277 TUNDEBUG(ifp, "tuninit\n");
1278
1279 TUN_LOCK(tp);
1280 ifp->if_drv_flags |= IFF_DRV_RUNNING;
1281 if ((tp->tun_flags & TUN_L2) == 0) {
1282 ifp->if_flags |= IFF_UP;
1283 getmicrotime(&ifp->if_lastchange);
1284 TUN_UNLOCK(tp);
1285 } else {
1286 #if defined(INET) || defined(INET6)
1287 if (tcp_lro_init(&tp->tun_lro) == 0) {
1288 TUNDEBUG(ifp, "LRO enabled\n");
1289 tp->tun_lro.ifp = ifp;
1290 tp->tun_lro_ready = true;
1291 } else {
1292 TUNDEBUG(ifp, "Could not enable LRO\n");
1293 tp->tun_lro_ready = false;
1294 }
1295 #endif
1296 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1297 TUN_UNLOCK(tp);
1298 /* attempt to start output */
1299 tunstart_l2(ifp);
1300 }
1301
1302 }
1303
1304 /*
1305 * Used only for l2 tunnel.
1306 */
1307 static void
tunifinit(void * xtp)1308 tunifinit(void *xtp)
1309 {
1310 struct tuntap_softc *tp;
1311
1312 tp = (struct tuntap_softc *)xtp;
1313 tuninit(tp->tun_ifp);
1314 }
1315
1316 /*
1317 * To be called under TUN_LOCK. Update ifp->if_hwassist according to the
1318 * current value of ifp->if_capenable.
1319 */
1320 static void
tun_caps_changed(struct ifnet * ifp)1321 tun_caps_changed(struct ifnet *ifp)
1322 {
1323 uint64_t hwassist = 0;
1324
1325 TUN_LOCK_ASSERT((struct tuntap_softc *)ifp->if_softc);
1326 if (ifp->if_capenable & IFCAP_TXCSUM)
1327 hwassist |= CSUM_TCP | CSUM_UDP;
1328 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
1329 hwassist |= CSUM_TCP_IPV6
1330 | CSUM_UDP_IPV6;
1331 if (ifp->if_capenable & IFCAP_TSO4)
1332 hwassist |= CSUM_IP_TSO;
1333 if (ifp->if_capenable & IFCAP_TSO6)
1334 hwassist |= CSUM_IP6_TSO;
1335 ifp->if_hwassist = hwassist;
1336 }
1337
1338 /*
1339 * To be called under TUN_LOCK. Update tp->tun_vhdrlen and adjust
1340 * if_capabilities and if_capenable as needed.
1341 */
1342 static void
tun_vnethdr_set(struct ifnet * ifp,int vhdrlen)1343 tun_vnethdr_set(struct ifnet *ifp, int vhdrlen)
1344 {
1345 struct tuntap_softc *tp = ifp->if_softc;
1346
1347 TUN_LOCK_ASSERT(tp);
1348
1349 if (tp->tun_vhdrlen == vhdrlen)
1350 return;
1351
1352 /*
1353 * Update if_capabilities to reflect the
1354 * functionalities offered by the virtio-net
1355 * header.
1356 */
1357 if (vhdrlen != 0)
1358 ifp->if_capabilities |=
1359 TAP_VNET_HDR_CAPS;
1360 else
1361 ifp->if_capabilities &=
1362 ~TAP_VNET_HDR_CAPS;
1363 /*
1364 * Disable any capabilities that we don't
1365 * support anymore.
1366 */
1367 ifp->if_capenable &= ifp->if_capabilities;
1368 tun_caps_changed(ifp);
1369 tp->tun_vhdrlen = vhdrlen;
1370
1371 TUNDEBUG(ifp, "vnet_hdr_len=%d, if_capabilities=%x\n",
1372 vhdrlen, ifp->if_capabilities);
1373 }
1374
1375 /*
1376 * Process an ioctl request.
1377 */
1378 static int
tunifioctl(struct ifnet * ifp,u_long cmd,caddr_t data)1379 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1380 {
1381 struct ifreq *ifr = (struct ifreq *)data;
1382 struct tuntap_softc *tp;
1383 struct ifstat *ifs;
1384 struct ifmediareq *ifmr;
1385 int dummy, error = 0;
1386 bool l2tun;
1387
1388 ifmr = NULL;
1389 sx_xlock(&tun_ioctl_sx);
1390 tp = ifp->if_softc;
1391 if (tp == NULL) {
1392 error = ENXIO;
1393 goto bad;
1394 }
1395 l2tun = (tp->tun_flags & TUN_L2) != 0;
1396 switch(cmd) {
1397 case SIOCGIFSTATUS:
1398 ifs = (struct ifstat *)data;
1399 TUN_LOCK(tp);
1400 if (tp->tun_pid)
1401 snprintf(ifs->ascii, sizeof(ifs->ascii),
1402 "\tOpened by PID %d\n", tp->tun_pid);
1403 else
1404 ifs->ascii[0] = '\0';
1405 TUN_UNLOCK(tp);
1406 break;
1407 case SIOCSIFADDR:
1408 if (l2tun)
1409 error = ether_ioctl(ifp, cmd, data);
1410 else
1411 tuninit(ifp);
1412 if (error == 0)
1413 TUNDEBUG(ifp, "address set\n");
1414 break;
1415 case SIOCSIFMTU:
1416 ifp->if_mtu = ifr->ifr_mtu;
1417 TUNDEBUG(ifp, "mtu set\n");
1418 break;
1419 case SIOCSIFFLAGS:
1420 case SIOCADDMULTI:
1421 case SIOCDELMULTI:
1422 break;
1423 case SIOCGIFMEDIA:
1424 if (!l2tun) {
1425 error = EINVAL;
1426 break;
1427 }
1428
1429 ifmr = (struct ifmediareq *)data;
1430 dummy = ifmr->ifm_count;
1431 ifmr->ifm_count = 1;
1432 ifmr->ifm_status = IFM_AVALID;
1433 ifmr->ifm_active = IFM_ETHER | IFM_FDX | IFM_1000_T;
1434 if (tp->tun_flags & TUN_OPEN)
1435 ifmr->ifm_status |= IFM_ACTIVE;
1436 ifmr->ifm_current = ifmr->ifm_active;
1437 if (dummy >= 1) {
1438 int media = IFM_ETHER;
1439 error = copyout(&media, ifmr->ifm_ulist, sizeof(int));
1440 }
1441 break;
1442 case SIOCSIFCAP:
1443 TUN_LOCK(tp);
1444 ifp->if_capenable = ifr->ifr_reqcap;
1445 tun_caps_changed(ifp);
1446 TUN_UNLOCK(tp);
1447 VLAN_CAPABILITIES(ifp);
1448 break;
1449 default:
1450 if (l2tun) {
1451 error = ether_ioctl(ifp, cmd, data);
1452 } else {
1453 error = EINVAL;
1454 }
1455 }
1456 bad:
1457 sx_xunlock(&tun_ioctl_sx);
1458 return (error);
1459 }
1460
1461 /*
1462 * tunoutput - queue packets from higher level ready to put out.
1463 */
1464 static int
tunoutput(struct ifnet * ifp,struct mbuf * m0,const struct sockaddr * dst,struct route * ro)1465 tunoutput(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
1466 struct route *ro)
1467 {
1468 struct tuntap_softc *tp = ifp->if_softc;
1469 u_short cached_tun_flags;
1470 int error;
1471 u_int32_t af;
1472
1473 TUNDEBUG (ifp, "tunoutput\n");
1474
1475 #ifdef MAC
1476 error = mac_ifnet_check_transmit(ifp, m0);
1477 if (error) {
1478 m_freem(m0);
1479 return (error);
1480 }
1481 #endif
1482
1483 /* Could be unlocked read? */
1484 TUN_LOCK(tp);
1485 cached_tun_flags = tp->tun_flags;
1486 TUN_UNLOCK(tp);
1487 if ((cached_tun_flags & TUN_READY) != TUN_READY) {
1488 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
1489 m_freem (m0);
1490 return (EHOSTDOWN);
1491 }
1492
1493 if ((ifp->if_flags & IFF_UP) != IFF_UP) {
1494 m_freem (m0);
1495 return (EHOSTDOWN);
1496 }
1497
1498 /* BPF writes need to be handled specially. */
1499 if (dst->sa_family == AF_UNSPEC || dst->sa_family == pseudo_AF_HDRCMPLT)
1500 bcopy(dst->sa_data, &af, sizeof(af));
1501 else
1502 af = RO_GET_FAMILY(ro, dst);
1503
1504 BPF_MTAP2(ifp, &af, sizeof(af), m0);
1505
1506 /* prepend sockaddr? this may abort if the mbuf allocation fails */
1507 if (cached_tun_flags & TUN_LMODE) {
1508 /* allocate space for sockaddr */
1509 M_PREPEND(m0, dst->sa_len, M_NOWAIT);
1510
1511 /* if allocation failed drop packet */
1512 if (m0 == NULL) {
1513 if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1514 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1515 return (ENOBUFS);
1516 } else {
1517 bcopy(dst, m0->m_data, dst->sa_len);
1518 }
1519 }
1520
1521 if (cached_tun_flags & TUN_IFHEAD) {
1522 /* Prepend the address family */
1523 M_PREPEND(m0, 4, M_NOWAIT);
1524
1525 /* if allocation failed drop packet */
1526 if (m0 == NULL) {
1527 if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1528 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1529 return (ENOBUFS);
1530 } else
1531 *(u_int32_t *)m0->m_data = htonl(af);
1532 } else {
1533 #ifdef INET
1534 if (af != AF_INET)
1535 #endif
1536 {
1537 m_freem(m0);
1538 return (EAFNOSUPPORT);
1539 }
1540 }
1541
1542 error = (ifp->if_transmit)(ifp, m0);
1543 if (error)
1544 return (ENOBUFS);
1545 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
1546 return (0);
1547 }
1548
1549 /*
1550 * the cdevsw interface is now pretty minimal.
1551 */
1552 static int
tunioctl(struct cdev * dev,u_long cmd,caddr_t data,int flag,struct thread * td)1553 tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag,
1554 struct thread *td)
1555 {
1556 struct ifreq ifr, *ifrp;
1557 struct tuntap_softc *tp = dev->si_drv1;
1558 struct ifnet *ifp = TUN2IFP(tp);
1559 struct tuninfo *tunp;
1560 int error, iflags, ival;
1561 bool l2tun;
1562
1563 l2tun = (tp->tun_flags & TUN_L2) != 0;
1564 if (l2tun) {
1565 /* tap specific ioctls */
1566 switch(cmd) {
1567 /* VMware/VMnet port ioctl's */
1568 #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
1569 defined(COMPAT_FREEBSD4)
1570 case _IO('V', 0):
1571 ival = IOCPARM_IVAL(data);
1572 data = (caddr_t)&ival;
1573 /* FALLTHROUGH */
1574 #endif
1575 case VMIO_SIOCSIFFLAGS: /* VMware/VMnet SIOCSIFFLAGS */
1576 iflags = *(int *)data;
1577 iflags &= TUN_VMIO_FLAG_MASK;
1578 iflags &= ~IFF_CANTCHANGE;
1579 iflags |= IFF_UP;
1580
1581 TUN_LOCK(tp);
1582 ifp->if_flags = iflags |
1583 (ifp->if_flags & IFF_CANTCHANGE);
1584 TUN_UNLOCK(tp);
1585
1586 return (0);
1587 case SIOCGIFADDR: /* get MAC address of the remote side */
1588 TUN_LOCK(tp);
1589 bcopy(&tp->tun_ether.octet, data,
1590 sizeof(tp->tun_ether.octet));
1591 TUN_UNLOCK(tp);
1592
1593 return (0);
1594 case SIOCSIFADDR: /* set MAC address of the remote side */
1595 TUN_LOCK(tp);
1596 bcopy(data, &tp->tun_ether.octet,
1597 sizeof(tp->tun_ether.octet));
1598 TUN_UNLOCK(tp);
1599
1600 return (0);
1601 case TAPSVNETHDR:
1602 ival = *(int *)data;
1603 if (ival != 0 &&
1604 ival != sizeof(struct virtio_net_hdr) &&
1605 ival != sizeof(struct virtio_net_hdr_mrg_rxbuf)) {
1606 return (EINVAL);
1607 }
1608 TUN_LOCK(tp);
1609 tun_vnethdr_set(ifp, ival);
1610 TUN_UNLOCK(tp);
1611
1612 return (0);
1613 case TAPGVNETHDR:
1614 TUN_LOCK(tp);
1615 *(int *)data = tp->tun_vhdrlen;
1616 TUN_UNLOCK(tp);
1617
1618 return (0);
1619 }
1620
1621 /* Fall through to the common ioctls if unhandled */
1622 } else {
1623 switch (cmd) {
1624 case TUNSLMODE:
1625 TUN_LOCK(tp);
1626 if (*(int *)data) {
1627 tp->tun_flags |= TUN_LMODE;
1628 tp->tun_flags &= ~TUN_IFHEAD;
1629 } else
1630 tp->tun_flags &= ~TUN_LMODE;
1631 TUN_UNLOCK(tp);
1632
1633 return (0);
1634 case TUNSIFHEAD:
1635 TUN_LOCK(tp);
1636 if (*(int *)data) {
1637 tp->tun_flags |= TUN_IFHEAD;
1638 tp->tun_flags &= ~TUN_LMODE;
1639 } else
1640 tp->tun_flags &= ~TUN_IFHEAD;
1641 TUN_UNLOCK(tp);
1642
1643 return (0);
1644 case TUNGIFHEAD:
1645 TUN_LOCK(tp);
1646 *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
1647 TUN_UNLOCK(tp);
1648
1649 return (0);
1650 case TUNSIFMODE:
1651 /* deny this if UP */
1652 if (TUN2IFP(tp)->if_flags & IFF_UP)
1653 return (EBUSY);
1654
1655 switch (*(int *)data & ~IFF_MULTICAST) {
1656 case IFF_POINTOPOINT:
1657 case IFF_BROADCAST:
1658 TUN_LOCK(tp);
1659 TUN2IFP(tp)->if_flags &=
1660 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
1661 TUN2IFP(tp)->if_flags |= *(int *)data;
1662 TUN_UNLOCK(tp);
1663
1664 break;
1665 default:
1666 return (EINVAL);
1667 }
1668
1669 return (0);
1670 case TUNSIFPID:
1671 TUN_LOCK(tp);
1672 tp->tun_pid = curthread->td_proc->p_pid;
1673 TUN_UNLOCK(tp);
1674
1675 return (0);
1676 }
1677 /* Fall through to the common ioctls if unhandled */
1678 }
1679
1680 switch (cmd) {
1681 case TUNGIFNAME:
1682 ifrp = (struct ifreq *)data;
1683 strlcpy(ifrp->ifr_name, TUN2IFP(tp)->if_xname, IFNAMSIZ);
1684
1685 return (0);
1686 case TUNSIFINFO:
1687 tunp = (struct tuninfo *)data;
1688 if (TUN2IFP(tp)->if_type != tunp->type)
1689 return (EPROTOTYPE);
1690 TUN_LOCK(tp);
1691 if (TUN2IFP(tp)->if_mtu != tunp->mtu) {
1692 strlcpy(ifr.ifr_name, if_name(TUN2IFP(tp)), IFNAMSIZ);
1693 ifr.ifr_mtu = tunp->mtu;
1694 CURVNET_SET(TUN2IFP(tp)->if_vnet);
1695 error = ifhwioctl(SIOCSIFMTU, TUN2IFP(tp),
1696 (caddr_t)&ifr, td);
1697 CURVNET_RESTORE();
1698 if (error) {
1699 TUN_UNLOCK(tp);
1700 return (error);
1701 }
1702 }
1703 TUN2IFP(tp)->if_baudrate = tunp->baudrate;
1704 TUN_UNLOCK(tp);
1705 break;
1706 case TUNGIFINFO:
1707 tunp = (struct tuninfo *)data;
1708 TUN_LOCK(tp);
1709 tunp->mtu = TUN2IFP(tp)->if_mtu;
1710 tunp->type = TUN2IFP(tp)->if_type;
1711 tunp->baudrate = TUN2IFP(tp)->if_baudrate;
1712 TUN_UNLOCK(tp);
1713 break;
1714 case TUNSDEBUG:
1715 tundebug = *(int *)data;
1716 break;
1717 case TUNGDEBUG:
1718 *(int *)data = tundebug;
1719 break;
1720 case TUNSTRANSIENT:
1721 TUN_LOCK(tp);
1722 if (*(int *)data)
1723 tp->tun_flags |= TUN_TRANSIENT;
1724 else
1725 tp->tun_flags &= ~TUN_TRANSIENT;
1726 TUN_UNLOCK(tp);
1727 break;
1728 case TUNGTRANSIENT:
1729 TUN_LOCK(tp);
1730 *(int *)data = (tp->tun_flags & TUN_TRANSIENT) != 0;
1731 TUN_UNLOCK(tp);
1732 break;
1733 case FIONBIO:
1734 break;
1735 case FIOASYNC:
1736 TUN_LOCK(tp);
1737 if (*(int *)data)
1738 tp->tun_flags |= TUN_ASYNC;
1739 else
1740 tp->tun_flags &= ~TUN_ASYNC;
1741 TUN_UNLOCK(tp);
1742 break;
1743 case FIONREAD:
1744 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) {
1745 struct mbuf *mb;
1746 IFQ_LOCK(&TUN2IFP(tp)->if_snd);
1747 IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb);
1748 for (*(int *)data = 0; mb != NULL; mb = mb->m_next)
1749 *(int *)data += mb->m_len;
1750 IFQ_UNLOCK(&TUN2IFP(tp)->if_snd);
1751 } else
1752 *(int *)data = 0;
1753 break;
1754 case FIOSETOWN:
1755 return (fsetown(*(int *)data, &tp->tun_sigio));
1756
1757 case FIOGETOWN:
1758 *(int *)data = fgetown(&tp->tun_sigio);
1759 return (0);
1760
1761 /* This is deprecated, FIOSETOWN should be used instead. */
1762 case TIOCSPGRP:
1763 return (fsetown(-(*(int *)data), &tp->tun_sigio));
1764
1765 /* This is deprecated, FIOGETOWN should be used instead. */
1766 case TIOCGPGRP:
1767 *(int *)data = -fgetown(&tp->tun_sigio);
1768 return (0);
1769
1770 default:
1771 return (ENOTTY);
1772 }
1773 return (0);
1774 }
1775
1776 /*
1777 * The cdevsw read interface - reads a packet at a time, or at
1778 * least as much of a packet as can be read.
1779 */
1780 static int
tunread(struct cdev * dev,struct uio * uio,int flag)1781 tunread(struct cdev *dev, struct uio *uio, int flag)
1782 {
1783 struct tuntap_softc *tp = dev->si_drv1;
1784 struct ifnet *ifp = TUN2IFP(tp);
1785 struct mbuf *m;
1786 size_t len;
1787 int error = 0;
1788
1789 TUNDEBUG (ifp, "read\n");
1790 TUN_LOCK(tp);
1791 if ((tp->tun_flags & TUN_READY) != TUN_READY) {
1792 TUN_UNLOCK(tp);
1793 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
1794 return (EHOSTDOWN);
1795 }
1796
1797 tp->tun_flags &= ~TUN_RWAIT;
1798
1799 for (;;) {
1800 IFQ_DEQUEUE(&ifp->if_snd, m);
1801 if (m != NULL)
1802 break;
1803 if (flag & O_NONBLOCK) {
1804 TUN_UNLOCK(tp);
1805 return (EWOULDBLOCK);
1806 }
1807 tp->tun_flags |= TUN_RWAIT;
1808 error = mtx_sleep(tp, &tp->tun_mtx, PCATCH | PZERO,
1809 "tunread", 0);
1810 if (error != 0) {
1811 TUN_UNLOCK(tp);
1812 return (error);
1813 }
1814 }
1815 TUN_UNLOCK(tp);
1816
1817 len = min(tp->tun_vhdrlen, uio->uio_resid);
1818 if (len > 0) {
1819 struct virtio_net_hdr_mrg_rxbuf vhdr;
1820
1821 bzero(&vhdr, sizeof(vhdr));
1822 if (m->m_pkthdr.csum_flags & TAP_ALL_OFFLOAD) {
1823 m = virtio_net_tx_offload(ifp, m, false, &vhdr.hdr);
1824 }
1825
1826 TUNDEBUG(ifp, "txvhdr: f %u, gt %u, hl %u, "
1827 "gs %u, cs %u, co %u\n", vhdr.hdr.flags,
1828 vhdr.hdr.gso_type, vhdr.hdr.hdr_len,
1829 vhdr.hdr.gso_size, vhdr.hdr.csum_start,
1830 vhdr.hdr.csum_offset);
1831 error = uiomove(&vhdr, len, uio);
1832 }
1833 if (error == 0)
1834 error = m_mbuftouio(uio, m, 0);
1835 m_freem(m);
1836 return (error);
1837 }
1838
1839 static int
tunwrite_l2(struct tuntap_softc * tp,struct mbuf * m,struct virtio_net_hdr_mrg_rxbuf * vhdr)1840 tunwrite_l2(struct tuntap_softc *tp, struct mbuf *m,
1841 struct virtio_net_hdr_mrg_rxbuf *vhdr)
1842 {
1843 struct epoch_tracker et;
1844 struct ether_header *eh;
1845 struct ifnet *ifp;
1846
1847 ifp = TUN2IFP(tp);
1848
1849 /*
1850 * Only pass a unicast frame to ether_input(), if it would
1851 * actually have been received by non-virtual hardware.
1852 */
1853 if (m->m_len < sizeof(struct ether_header)) {
1854 m_freem(m);
1855 return (0);
1856 }
1857
1858 eh = mtod(m, struct ether_header *);
1859
1860 if ((ifp->if_flags & IFF_PROMISC) == 0 &&
1861 !ETHER_IS_MULTICAST(eh->ether_dhost) &&
1862 bcmp(eh->ether_dhost, IF_LLADDR(ifp), ETHER_ADDR_LEN) != 0) {
1863 m_freem(m);
1864 return (0);
1865 }
1866
1867 if (vhdr != NULL) {
1868 if (virtio_net_rx_csum(m, &vhdr->hdr)) {
1869 m_freem(m);
1870 return (0);
1871 }
1872 } else {
1873 switch (ntohs(eh->ether_type)) {
1874 #ifdef INET
1875 case ETHERTYPE_IP:
1876 if (ifp->if_capenable & IFCAP_RXCSUM) {
1877 m->m_pkthdr.csum_flags |=
1878 CSUM_IP_CHECKED | CSUM_IP_VALID |
1879 CSUM_DATA_VALID | CSUM_SCTP_VALID |
1880 CSUM_PSEUDO_HDR;
1881 m->m_pkthdr.csum_data = 0xffff;
1882 }
1883 break;
1884 #endif
1885 #ifdef INET6
1886 case ETHERTYPE_IPV6:
1887 if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) {
1888 m->m_pkthdr.csum_flags |=
1889 CSUM_DATA_VALID_IPV6 | CSUM_SCTP_VALID |
1890 CSUM_PSEUDO_HDR;
1891 m->m_pkthdr.csum_data = 0xffff;
1892 }
1893 break;
1894 #endif
1895 }
1896 }
1897
1898 /* Pass packet up to parent. */
1899 CURVNET_SET(ifp->if_vnet);
1900 NET_EPOCH_ENTER(et);
1901 #if defined(INET) || defined(INET6)
1902 if (tp->tun_lro_ready && ifp->if_capenable & IFCAP_LRO &&
1903 tcp_lro_rx(&tp->tun_lro, m, 0) == 0)
1904 tcp_lro_flush_all(&tp->tun_lro);
1905 else
1906 #endif
1907 (*ifp->if_input)(ifp, m);
1908 NET_EPOCH_EXIT(et);
1909 CURVNET_RESTORE();
1910 /* ibytes are counted in parent */
1911 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1912 return (0);
1913 }
1914
1915 static int
tunwrite_l3(struct tuntap_softc * tp,struct mbuf * m)1916 tunwrite_l3(struct tuntap_softc *tp, struct mbuf *m)
1917 {
1918 struct epoch_tracker et;
1919 struct ifnet *ifp;
1920 int family, isr;
1921
1922 ifp = TUN2IFP(tp);
1923 /* Could be unlocked read? */
1924 TUN_LOCK(tp);
1925 if (tp->tun_flags & TUN_IFHEAD) {
1926 TUN_UNLOCK(tp);
1927 if (m->m_len < sizeof(family) &&
1928 (m = m_pullup(m, sizeof(family))) == NULL)
1929 return (ENOBUFS);
1930 family = ntohl(*mtod(m, u_int32_t *));
1931 m_adj(m, sizeof(family));
1932 } else {
1933 TUN_UNLOCK(tp);
1934 family = AF_INET;
1935 }
1936
1937 BPF_MTAP2(ifp, &family, sizeof(family), m);
1938
1939 switch (family) {
1940 #ifdef INET
1941 case AF_INET:
1942 isr = NETISR_IP;
1943 break;
1944 #endif
1945 #ifdef INET6
1946 case AF_INET6:
1947 isr = NETISR_IPV6;
1948 break;
1949 #endif
1950 default:
1951 m_freem(m);
1952 return (EAFNOSUPPORT);
1953 }
1954 random_harvest_queue(m, sizeof(*m), RANDOM_NET_TUN);
1955 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
1956 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1957 CURVNET_SET(ifp->if_vnet);
1958 M_SETFIB(m, ifp->if_fib);
1959 NET_EPOCH_ENTER(et);
1960 netisr_dispatch(isr, m);
1961 NET_EPOCH_EXIT(et);
1962 CURVNET_RESTORE();
1963 return (0);
1964 }
1965
1966 /*
1967 * the cdevsw write interface - an atomic write is a packet - or else!
1968 */
1969 static int
tunwrite(struct cdev * dev,struct uio * uio,int flag)1970 tunwrite(struct cdev *dev, struct uio *uio, int flag)
1971 {
1972 struct virtio_net_hdr_mrg_rxbuf vhdr;
1973 struct tuntap_softc *tp;
1974 struct ifnet *ifp;
1975 struct mbuf *m;
1976 uint32_t mru;
1977 int align, vhdrlen, error;
1978 bool l2tun;
1979
1980 tp = dev->si_drv1;
1981 ifp = TUN2IFP(tp);
1982 TUNDEBUG(ifp, "tunwrite\n");
1983 if ((ifp->if_flags & IFF_UP) != IFF_UP)
1984 /* ignore silently */
1985 return (0);
1986
1987 if (uio->uio_resid == 0)
1988 return (0);
1989
1990 l2tun = (tp->tun_flags & TUN_L2) != 0;
1991 mru = l2tun ? TAPMRU : TUNMRU;
1992 vhdrlen = tp->tun_vhdrlen;
1993 align = 0;
1994 if (l2tun) {
1995 align = ETHER_ALIGN;
1996 mru += vhdrlen;
1997 } else if ((tp->tun_flags & TUN_IFHEAD) != 0)
1998 mru += sizeof(uint32_t); /* family */
1999 if (uio->uio_resid < 0 || uio->uio_resid > mru) {
2000 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid);
2001 return (EIO);
2002 }
2003
2004 if (vhdrlen > 0) {
2005 error = uiomove(&vhdr, vhdrlen, uio);
2006 if (error != 0)
2007 return (error);
2008 TUNDEBUG(ifp, "txvhdr: f %u, gt %u, hl %u, "
2009 "gs %u, cs %u, co %u\n", vhdr.hdr.flags,
2010 vhdr.hdr.gso_type, vhdr.hdr.hdr_len,
2011 vhdr.hdr.gso_size, vhdr.hdr.csum_start,
2012 vhdr.hdr.csum_offset);
2013 }
2014
2015 if ((m = m_uiotombuf(uio, M_NOWAIT, 0, align, M_PKTHDR)) == NULL) {
2016 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
2017 return (ENOBUFS);
2018 }
2019
2020 m->m_pkthdr.rcvif = ifp;
2021 #ifdef MAC
2022 mac_ifnet_create_mbuf(ifp, m);
2023 #endif
2024
2025 if (l2tun)
2026 return (tunwrite_l2(tp, m, vhdrlen > 0 ? &vhdr : NULL));
2027
2028 return (tunwrite_l3(tp, m));
2029 }
2030
2031 /*
2032 * tunpoll - the poll interface, this is only useful on reads
2033 * really. The write detect always returns true, write never blocks
2034 * anyway, it either accepts the packet or drops it.
2035 */
2036 static int
tunpoll(struct cdev * dev,int events,struct thread * td)2037 tunpoll(struct cdev *dev, int events, struct thread *td)
2038 {
2039 struct tuntap_softc *tp = dev->si_drv1;
2040 struct ifnet *ifp = TUN2IFP(tp);
2041 int revents = 0;
2042
2043 TUNDEBUG(ifp, "tunpoll\n");
2044
2045 if (events & (POLLIN | POLLRDNORM)) {
2046 IFQ_LOCK(&ifp->if_snd);
2047 if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
2048 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len);
2049 revents |= events & (POLLIN | POLLRDNORM);
2050 } else {
2051 TUNDEBUG(ifp, "tunpoll waiting\n");
2052 selrecord(td, &tp->tun_rsel);
2053 }
2054 IFQ_UNLOCK(&ifp->if_snd);
2055 }
2056 revents |= events & (POLLOUT | POLLWRNORM);
2057
2058 return (revents);
2059 }
2060
2061 /*
2062 * tunkqfilter - support for the kevent() system call.
2063 */
2064 static int
tunkqfilter(struct cdev * dev,struct knote * kn)2065 tunkqfilter(struct cdev *dev, struct knote *kn)
2066 {
2067 struct tuntap_softc *tp = dev->si_drv1;
2068 struct ifnet *ifp = TUN2IFP(tp);
2069
2070 switch(kn->kn_filter) {
2071 case EVFILT_READ:
2072 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n",
2073 ifp->if_xname, dev2unit(dev));
2074 kn->kn_fop = &tun_read_filterops;
2075 break;
2076
2077 case EVFILT_WRITE:
2078 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n",
2079 ifp->if_xname, dev2unit(dev));
2080 kn->kn_fop = &tun_write_filterops;
2081 break;
2082
2083 default:
2084 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n",
2085 ifp->if_xname, dev2unit(dev));
2086 return(EINVAL);
2087 }
2088
2089 kn->kn_hook = tp;
2090 knlist_add(&tp->tun_rsel.si_note, kn, 0);
2091
2092 return (0);
2093 }
2094
2095 /*
2096 * Return true of there is data in the interface queue.
2097 */
2098 static int
tunkqread(struct knote * kn,long hint)2099 tunkqread(struct knote *kn, long hint)
2100 {
2101 int ret;
2102 struct tuntap_softc *tp = kn->kn_hook;
2103 struct cdev *dev = tp->tun_dev;
2104 struct ifnet *ifp = TUN2IFP(tp);
2105
2106 if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) {
2107 TUNDEBUG(ifp,
2108 "%s have data in the queue. Len = %d, minor = %#x\n",
2109 ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev));
2110 ret = 1;
2111 } else {
2112 TUNDEBUG(ifp,
2113 "%s waiting for data, minor = %#x\n", ifp->if_xname,
2114 dev2unit(dev));
2115 ret = 0;
2116 }
2117
2118 return (ret);
2119 }
2120
2121 /*
2122 * Always can write, always return MTU in kn->data.
2123 */
2124 static int
tunkqwrite(struct knote * kn,long hint)2125 tunkqwrite(struct knote *kn, long hint)
2126 {
2127 struct tuntap_softc *tp = kn->kn_hook;
2128 struct ifnet *ifp = TUN2IFP(tp);
2129
2130 kn->kn_data = ifp->if_mtu;
2131
2132 return (1);
2133 }
2134
2135 static void
tunkqdetach(struct knote * kn)2136 tunkqdetach(struct knote *kn)
2137 {
2138 struct tuntap_softc *tp = kn->kn_hook;
2139
2140 knlist_remove(&tp->tun_rsel.si_note, kn, 0);
2141 }
2142