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_types.h>
85 #include <net/if_vlan_var.h>
86 #include <net/netisr.h>
87 #include <net/route.h>
88 #include <net/vnet.h>
89 #include <netinet/in.h>
90 #ifdef INET
91 #include <netinet/ip.h>
92 #endif
93 #ifdef INET6
94 #include <netinet/ip6.h>
95 #include <netinet6/ip6_var.h>
96 #endif
97 #include <netinet/udp.h>
98 #include <netinet/tcp.h>
99 #include <netinet/tcp_lro.h>
100 #include <net/bpf.h>
101 #include <net/if_tap.h>
102 #include <net/if_tun.h>
103
104 #include <dev/virtio/network/virtio_net.h>
105
106 #include <sys/queue.h>
107 #include <sys/condvar.h>
108 #include <security/mac/mac_framework.h>
109
110 struct tuntap_driver;
111
112 /*
113 * tun_list is protected by global tunmtx. Other mutable fields are
114 * protected by tun->tun_mtx, or by their owning subsystem. tun_dev is
115 * static for the duration of a tunnel interface.
116 */
117 struct tuntap_softc {
118 TAILQ_ENTRY(tuntap_softc) tun_list;
119 struct cdev *tun_alias;
120 struct cdev *tun_dev;
121 u_short tun_flags; /* misc flags */
122 #define TUN_OPEN 0x0001
123 #define TUN_INITED 0x0002
124 #define TUN_UNUSED1 0x0008
125 #define TUN_UNUSED2 0x0010
126 #define TUN_LMODE 0x0020
127 #define TUN_RWAIT 0x0040
128 #define TUN_ASYNC 0x0080
129 #define TUN_IFHEAD 0x0100
130 #define TUN_DYING 0x0200
131 #define TUN_L2 0x0400
132 #define TUN_VMNET 0x0800
133
134 #define TUN_DRIVER_IDENT_MASK (TUN_L2 | TUN_VMNET)
135 #define TUN_READY (TUN_OPEN | TUN_INITED)
136
137 pid_t tun_pid; /* owning pid */
138 struct ifnet *tun_ifp; /* the interface */
139 struct sigio *tun_sigio; /* async I/O info */
140 struct tuntap_driver *tun_drv; /* appropriate driver */
141 struct selinfo tun_rsel; /* read select */
142 struct mtx tun_mtx; /* softc field mutex */
143 struct cv tun_cv; /* for ref'd dev destroy */
144 struct ether_addr tun_ether; /* remote address */
145 int tun_busy; /* busy count */
146 int tun_vhdrlen; /* virtio-net header length */
147 struct lro_ctrl tun_lro; /* for TCP LRO */
148 bool tun_lro_ready; /* TCP LRO initialized */
149 };
150 #define TUN2IFP(sc) ((sc)->tun_ifp)
151
152 #define TUNDEBUG if (tundebug) if_printf
153
154 #define TUN_LOCK(tp) mtx_lock(&(tp)->tun_mtx)
155 #define TUN_UNLOCK(tp) mtx_unlock(&(tp)->tun_mtx)
156 #define TUN_LOCK_ASSERT(tp) mtx_assert(&(tp)->tun_mtx, MA_OWNED);
157
158 #define TUN_VMIO_FLAG_MASK 0x0fff
159
160 /*
161 * Interface capabilities of a tap device that supports the virtio-net
162 * header.
163 */
164 #define TAP_VNET_HDR_CAPS (IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6 \
165 | IFCAP_VLAN_HWCSUM \
166 | IFCAP_TSO | IFCAP_LRO \
167 | IFCAP_VLAN_HWTSO)
168
169 #define TAP_ALL_OFFLOAD (CSUM_TSO | CSUM_TCP | CSUM_UDP |\
170 CSUM_TCP_IPV6 | CSUM_UDP_IPV6)
171
172 /*
173 * All mutable global variables in if_tun are locked using tunmtx, with
174 * the exception of tundebug, which is used unlocked, and the drivers' *clones,
175 * which are static after setup.
176 */
177 static struct mtx tunmtx;
178 static eventhandler_tag arrival_tag;
179 static eventhandler_tag clone_tag;
180 static const char tunname[] = "tun";
181 static const char tapname[] = "tap";
182 static const char vmnetname[] = "vmnet";
183 static MALLOC_DEFINE(M_TUN, tunname, "Tunnel Interface");
184 static int tundebug = 0;
185 static int tundclone = 1;
186 static int tap_allow_uopen = 0; /* allow user devfs cloning */
187 static int tapuponopen = 0; /* IFF_UP on open() */
188 static int tapdclone = 1; /* enable devfs cloning */
189
190 static TAILQ_HEAD(,tuntap_softc) tunhead = TAILQ_HEAD_INITIALIZER(tunhead);
191 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");
192
193 static struct sx tun_ioctl_sx;
194 SX_SYSINIT(tun_ioctl_sx, &tun_ioctl_sx, "tun_ioctl");
195
196 SYSCTL_DECL(_net_link);
197 /* tun */
198 static SYSCTL_NODE(_net_link, OID_AUTO, tun, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
199 "IP tunnel software network interface");
200 SYSCTL_INT(_net_link_tun, OID_AUTO, devfs_cloning, CTLFLAG_RWTUN, &tundclone, 0,
201 "Enable legacy devfs interface creation");
202
203 /* tap */
204 static SYSCTL_NODE(_net_link, OID_AUTO, tap, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
205 "Ethernet tunnel software network interface");
206 SYSCTL_INT(_net_link_tap, OID_AUTO, user_open, CTLFLAG_RW, &tap_allow_uopen, 0,
207 "Enable legacy devfs interface creation for all users");
208 SYSCTL_INT(_net_link_tap, OID_AUTO, up_on_open, CTLFLAG_RW, &tapuponopen, 0,
209 "Bring interface up when /dev/tap is opened");
210 SYSCTL_INT(_net_link_tap, OID_AUTO, devfs_cloning, CTLFLAG_RWTUN, &tapdclone, 0,
211 "Enable legacy devfs interface creation");
212 SYSCTL_INT(_net_link_tap, OID_AUTO, debug, CTLFLAG_RW, &tundebug, 0, "");
213
214 static int tun_create_device(struct tuntap_driver *drv, int unit,
215 struct ucred *cr, struct cdev **dev, const char *name);
216 static int tun_busy_locked(struct tuntap_softc *tp);
217 static void tun_unbusy_locked(struct tuntap_softc *tp);
218 static int tun_busy(struct tuntap_softc *tp);
219 static void tun_unbusy(struct tuntap_softc *tp);
220
221 static int tuntap_name2info(const char *name, int *unit, int *flags);
222 static void tunclone(void *arg, struct ucred *cred, char *name,
223 int namelen, struct cdev **dev);
224 static void tuncreate(struct cdev *dev);
225 static void tundtor(void *data);
226 static void tunrename(void *arg, struct ifnet *ifp);
227 static int tunifioctl(struct ifnet *, u_long, caddr_t);
228 static void tuninit(struct ifnet *);
229 static void tunifinit(void *xtp);
230 static int tuntapmodevent(module_t, int, void *);
231 static int tunoutput(struct ifnet *, struct mbuf *,
232 const struct sockaddr *, struct route *ro);
233 static void tunstart(struct ifnet *);
234 static void tunstart_l2(struct ifnet *);
235
236 static int tun_clone_match(struct if_clone *ifc, const char *name);
237 static int tap_clone_match(struct if_clone *ifc, const char *name);
238 static int vmnet_clone_match(struct if_clone *ifc, const char *name);
239 static int tun_clone_create(struct if_clone *, char *, size_t, caddr_t);
240 static int tun_clone_destroy(struct if_clone *, struct ifnet *);
241 static void tun_vnethdr_set(struct ifnet *ifp, int vhdrlen);
242
243 static d_open_t tunopen;
244 static d_read_t tunread;
245 static d_write_t tunwrite;
246 static d_ioctl_t tunioctl;
247 static d_poll_t tunpoll;
248 static d_kqfilter_t tunkqfilter;
249
250 static int tunkqread(struct knote *, long);
251 static int tunkqwrite(struct knote *, long);
252 static void tunkqdetach(struct knote *);
253
254 static struct filterops tun_read_filterops = {
255 .f_isfd = 1,
256 .f_attach = NULL,
257 .f_detach = tunkqdetach,
258 .f_event = tunkqread,
259 };
260
261 static struct filterops tun_write_filterops = {
262 .f_isfd = 1,
263 .f_attach = NULL,
264 .f_detach = tunkqdetach,
265 .f_event = tunkqwrite,
266 };
267
268 static struct tuntap_driver {
269 struct cdevsw cdevsw;
270 int ident_flags;
271 struct unrhdr *unrhdr;
272 struct clonedevs *clones;
273 ifc_match_t *clone_match_fn;
274 ifc_create_t *clone_create_fn;
275 ifc_destroy_t *clone_destroy_fn;
276 } tuntap_drivers[] = {
277 {
278 .ident_flags = 0,
279 .cdevsw = {
280 .d_version = D_VERSION,
281 .d_flags = D_NEEDMINOR,
282 .d_open = tunopen,
283 .d_read = tunread,
284 .d_write = tunwrite,
285 .d_ioctl = tunioctl,
286 .d_poll = tunpoll,
287 .d_kqfilter = tunkqfilter,
288 .d_name = tunname,
289 },
290 .clone_match_fn = tun_clone_match,
291 .clone_create_fn = tun_clone_create,
292 .clone_destroy_fn = tun_clone_destroy,
293 },
294 {
295 .ident_flags = TUN_L2,
296 .cdevsw = {
297 .d_version = D_VERSION,
298 .d_flags = D_NEEDMINOR,
299 .d_open = tunopen,
300 .d_read = tunread,
301 .d_write = tunwrite,
302 .d_ioctl = tunioctl,
303 .d_poll = tunpoll,
304 .d_kqfilter = tunkqfilter,
305 .d_name = tapname,
306 },
307 .clone_match_fn = tap_clone_match,
308 .clone_create_fn = tun_clone_create,
309 .clone_destroy_fn = tun_clone_destroy,
310 },
311 {
312 .ident_flags = TUN_L2 | TUN_VMNET,
313 .cdevsw = {
314 .d_version = D_VERSION,
315 .d_flags = D_NEEDMINOR,
316 .d_open = tunopen,
317 .d_read = tunread,
318 .d_write = tunwrite,
319 .d_ioctl = tunioctl,
320 .d_poll = tunpoll,
321 .d_kqfilter = tunkqfilter,
322 .d_name = vmnetname,
323 },
324 .clone_match_fn = vmnet_clone_match,
325 .clone_create_fn = tun_clone_create,
326 .clone_destroy_fn = tun_clone_destroy,
327 },
328 };
329
330 struct tuntap_driver_cloner {
331 SLIST_ENTRY(tuntap_driver_cloner) link;
332 struct tuntap_driver *drv;
333 struct if_clone *cloner;
334 };
335
336 VNET_DEFINE_STATIC(SLIST_HEAD(, tuntap_driver_cloner), tuntap_driver_cloners) =
337 SLIST_HEAD_INITIALIZER(tuntap_driver_cloners);
338
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 struct tuntap_driver_cloner *drvc;
408 char *dname;
409 int flags, unit;
410 bool found;
411
412 if (name == NULL)
413 return (EINVAL);
414
415 /*
416 * Needed for dev_stdclone, but dev_stdclone will not modify, it just
417 * wants to be able to pass back a char * through the second param. We
418 * will always set that as NULL here, so we'll fake it.
419 */
420 dname = __DECONST(char *, name);
421 found = false;
422
423 KASSERT(!SLIST_EMPTY(&V_tuntap_driver_cloners),
424 ("tuntap_driver_cloners failed to initialize"));
425 SLIST_FOREACH(drvc, &V_tuntap_driver_cloners, link) {
426 KASSERT(drvc->drv != NULL,
427 ("tuntap_driver_cloners entry not properly initialized"));
428 drv = drvc->drv;
429
430 if (strcmp(name, drv->cdevsw.d_name) == 0) {
431 found = true;
432 unit = -1;
433 flags = drv->ident_flags;
434 break;
435 }
436
437 if (dev_stdclone(dname, NULL, drv->cdevsw.d_name, &unit) == 1) {
438 found = true;
439 flags = drv->ident_flags;
440 break;
441 }
442 }
443
444 if (!found)
445 return (ENXIO);
446
447 if (outunit != NULL)
448 *outunit = unit;
449 if (outflags != NULL)
450 *outflags = flags;
451 return (0);
452 }
453
454 /*
455 * Get driver information from a set of flags specified. Masks the identifying
456 * part of the flags and compares it against all of the available
457 * tuntap_drivers. Must be called with correct vnet context.
458 */
459 static struct tuntap_driver *
tuntap_driver_from_flags(int tun_flags)460 tuntap_driver_from_flags(int tun_flags)
461 {
462 struct tuntap_driver *drv;
463 struct tuntap_driver_cloner *drvc;
464
465 KASSERT(!SLIST_EMPTY(&V_tuntap_driver_cloners),
466 ("tuntap_driver_cloners failed to initialize"));
467 SLIST_FOREACH(drvc, &V_tuntap_driver_cloners, link) {
468 KASSERT(drvc->drv != NULL,
469 ("tuntap_driver_cloners entry not properly initialized"));
470 drv = drvc->drv;
471 if ((tun_flags & TUN_DRIVER_IDENT_MASK) == drv->ident_flags)
472 return (drv);
473 }
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 static int
tun_clone_create(struct if_clone * ifc,char * name,size_t len,caddr_t params)518 tun_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
519 {
520 struct tuntap_driver *drv;
521 struct cdev *dev;
522 int err, i, tunflags, unit;
523
524 tunflags = 0;
525 /* The name here tells us exactly what we're creating */
526 err = tuntap_name2info(name, &unit, &tunflags);
527 if (err != 0)
528 return (err);
529
530 drv = tuntap_driver_from_flags(tunflags);
531 if (drv == NULL)
532 return (ENXIO);
533
534 if (unit != -1) {
535 /* If this unit number is still available that's okay. */
536 if (alloc_unr_specific(drv->unrhdr, unit) == -1)
537 return (EEXIST);
538 } else {
539 unit = alloc_unr(drv->unrhdr);
540 }
541
542 snprintf(name, IFNAMSIZ, "%s%d", drv->cdevsw.d_name, unit);
543
544 /* find any existing device, or allocate new unit number */
545 dev = NULL;
546 i = clone_create(&drv->clones, &drv->cdevsw, &unit, &dev, 0);
547 if (i == 0)
548 dev_ref(dev);
549 /* No preexisting struct cdev *, create one */
550 if (i != 0)
551 i = tun_create_device(drv, unit, NULL, &dev, name);
552 if (i == 0)
553 tuncreate(dev);
554
555 return (i);
556 }
557
558 static void
tunclone(void * arg,struct ucred * cred,char * name,int namelen,struct cdev ** dev)559 tunclone(void *arg, struct ucred *cred, char *name, int namelen,
560 struct cdev **dev)
561 {
562 char devname[SPECNAMELEN + 1];
563 struct tuntap_driver *drv;
564 int append_unit, i, u, tunflags;
565 bool mayclone;
566
567 if (*dev != NULL)
568 return;
569
570 tunflags = 0;
571 CURVNET_SET(CRED_TO_VNET(cred));
572 if (tuntap_name2info(name, &u, &tunflags) != 0)
573 goto out; /* Not recognized */
574
575 if (u != -1 && u > IF_MAXUNIT)
576 goto out; /* Unit number too high */
577
578 mayclone = priv_check_cred(cred, PRIV_NET_IFCREATE) == 0;
579 if ((tunflags & TUN_L2) != 0) {
580 /* tap/vmnet allow user open with a sysctl */
581 mayclone = (mayclone || tap_allow_uopen) && tapdclone;
582 } else {
583 mayclone = mayclone && tundclone;
584 }
585
586 /*
587 * If tun cloning is enabled, only the superuser can create an
588 * interface.
589 */
590 if (!mayclone)
591 goto out;
592
593 if (u == -1)
594 append_unit = 1;
595 else
596 append_unit = 0;
597
598 drv = tuntap_driver_from_flags(tunflags);
599 if (drv == NULL)
600 goto out;
601
602 /* find any existing device, or allocate new unit number */
603 i = clone_create(&drv->clones, &drv->cdevsw, &u, dev, 0);
604 if (i == 0)
605 dev_ref(*dev);
606 if (i) {
607 if (append_unit) {
608 namelen = snprintf(devname, sizeof(devname), "%s%d",
609 name, u);
610 name = devname;
611 }
612
613 i = tun_create_device(drv, u, cred, dev, name);
614 }
615 if (i == 0)
616 if_clone_create(name, namelen, NULL);
617 out:
618 CURVNET_RESTORE();
619 }
620
621 static void
tun_destroy(struct tuntap_softc * tp)622 tun_destroy(struct tuntap_softc *tp)
623 {
624
625 TUN_LOCK(tp);
626 tp->tun_flags |= TUN_DYING;
627 if (tp->tun_busy != 0)
628 cv_wait_unlock(&tp->tun_cv, &tp->tun_mtx);
629 else
630 TUN_UNLOCK(tp);
631
632 CURVNET_SET(TUN2IFP(tp)->if_vnet);
633
634 /* destroy_dev will take care of any alias. */
635 destroy_dev(tp->tun_dev);
636 seldrain(&tp->tun_rsel);
637 knlist_clear(&tp->tun_rsel.si_note, 0);
638 knlist_destroy(&tp->tun_rsel.si_note);
639 if ((tp->tun_flags & TUN_L2) != 0) {
640 ether_ifdetach(TUN2IFP(tp));
641 } else {
642 bpfdetach(TUN2IFP(tp));
643 if_detach(TUN2IFP(tp));
644 }
645 sx_xlock(&tun_ioctl_sx);
646 TUN2IFP(tp)->if_softc = NULL;
647 sx_xunlock(&tun_ioctl_sx);
648 free_unr(tp->tun_drv->unrhdr, TUN2IFP(tp)->if_dunit);
649 if_free(TUN2IFP(tp));
650 mtx_destroy(&tp->tun_mtx);
651 cv_destroy(&tp->tun_cv);
652 free(tp, M_TUN);
653 CURVNET_RESTORE();
654 }
655
656 static int
tun_clone_destroy(struct if_clone * ifc __unused,struct ifnet * ifp)657 tun_clone_destroy(struct if_clone *ifc __unused, struct ifnet *ifp)
658 {
659 struct tuntap_softc *tp = ifp->if_softc;
660
661 mtx_lock(&tunmtx);
662 TAILQ_REMOVE(&tunhead, tp, tun_list);
663 mtx_unlock(&tunmtx);
664 tun_destroy(tp);
665
666 return (0);
667 }
668
669 static void
vnet_tun_init(const void * unused __unused)670 vnet_tun_init(const void *unused __unused)
671 {
672 struct tuntap_driver *drv;
673 struct tuntap_driver_cloner *drvc;
674 int i;
675
676 for (i = 0; i < nitems(tuntap_drivers); ++i) {
677 drv = &tuntap_drivers[i];
678 drvc = malloc(sizeof(*drvc), M_TUN, M_WAITOK | M_ZERO);
679
680 drvc->drv = drv;
681 drvc->cloner = if_clone_advanced(drv->cdevsw.d_name, 0,
682 drv->clone_match_fn, drv->clone_create_fn,
683 drv->clone_destroy_fn);
684 SLIST_INSERT_HEAD(&V_tuntap_driver_cloners, drvc, link);
685 };
686 }
687 VNET_SYSINIT(vnet_tun_init, SI_SUB_PROTO_IF, SI_ORDER_ANY,
688 vnet_tun_init, NULL);
689
690 static void
vnet_tun_uninit(const void * unused __unused)691 vnet_tun_uninit(const void *unused __unused)
692 {
693 struct tuntap_driver_cloner *drvc;
694
695 while (!SLIST_EMPTY(&V_tuntap_driver_cloners)) {
696 drvc = SLIST_FIRST(&V_tuntap_driver_cloners);
697 SLIST_REMOVE_HEAD(&V_tuntap_driver_cloners, link);
698
699 if_clone_detach(drvc->cloner);
700 free(drvc, M_TUN);
701 }
702 }
703 VNET_SYSUNINIT(vnet_tun_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY,
704 vnet_tun_uninit, NULL);
705
706 static void
tun_uninit(const void * unused __unused)707 tun_uninit(const void *unused __unused)
708 {
709 struct tuntap_driver *drv;
710 struct tuntap_softc *tp;
711 int i;
712
713 EVENTHANDLER_DEREGISTER(ifnet_arrival_event, arrival_tag);
714 EVENTHANDLER_DEREGISTER(dev_clone, clone_tag);
715 drain_dev_clone_events();
716
717 mtx_lock(&tunmtx);
718 while ((tp = TAILQ_FIRST(&tunhead)) != NULL) {
719 TAILQ_REMOVE(&tunhead, tp, tun_list);
720 mtx_unlock(&tunmtx);
721 tun_destroy(tp);
722 mtx_lock(&tunmtx);
723 }
724 mtx_unlock(&tunmtx);
725 for (i = 0; i < nitems(tuntap_drivers); ++i) {
726 drv = &tuntap_drivers[i];
727 delete_unrhdr(drv->unrhdr);
728 clone_cleanup(&drv->clones);
729 }
730 mtx_destroy(&tunmtx);
731 }
732 SYSUNINIT(tun_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY, tun_uninit, NULL);
733
734 static struct tuntap_driver *
tuntap_driver_from_ifnet(const struct ifnet * ifp)735 tuntap_driver_from_ifnet(const struct ifnet *ifp)
736 {
737 struct tuntap_driver *drv;
738 int i;
739
740 if (ifp == NULL)
741 return (NULL);
742
743 for (i = 0; i < nitems(tuntap_drivers); ++i) {
744 drv = &tuntap_drivers[i];
745 if (strcmp(ifp->if_dname, drv->cdevsw.d_name) == 0)
746 return (drv);
747 }
748
749 return (NULL);
750 }
751
752 static int
tuntapmodevent(module_t mod,int type,void * data)753 tuntapmodevent(module_t mod, int type, void *data)
754 {
755 struct tuntap_driver *drv;
756 int i;
757
758 switch (type) {
759 case MOD_LOAD:
760 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF);
761 for (i = 0; i < nitems(tuntap_drivers); ++i) {
762 drv = &tuntap_drivers[i];
763 clone_setup(&drv->clones);
764 drv->unrhdr = new_unrhdr(0, IF_MAXUNIT, &tunmtx);
765 }
766 arrival_tag = EVENTHANDLER_REGISTER(ifnet_arrival_event,
767 tunrename, 0, 1000);
768 if (arrival_tag == NULL)
769 return (ENOMEM);
770 clone_tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000);
771 if (clone_tag == NULL)
772 return (ENOMEM);
773 break;
774 case MOD_UNLOAD:
775 /* See tun_uninit, so it's done after the vnet_sysuninit() */
776 break;
777 default:
778 return EOPNOTSUPP;
779 }
780 return 0;
781 }
782
783 static moduledata_t tuntap_mod = {
784 "if_tuntap",
785 tuntapmodevent,
786 0
787 };
788
789 /* We'll only ever have these two, so no need for a macro. */
790 static moduledata_t tun_mod = { "if_tun", NULL, 0 };
791 static moduledata_t tap_mod = { "if_tap", NULL, 0 };
792
793 DECLARE_MODULE(if_tuntap, tuntap_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
794 MODULE_VERSION(if_tuntap, 1);
795 DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
796 MODULE_VERSION(if_tun, 1);
797 DECLARE_MODULE(if_tap, tap_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
798 MODULE_VERSION(if_tap, 1);
799
800 static int
tun_create_device(struct tuntap_driver * drv,int unit,struct ucred * cr,struct cdev ** dev,const char * name)801 tun_create_device(struct tuntap_driver *drv, int unit, struct ucred *cr,
802 struct cdev **dev, const char *name)
803 {
804 struct make_dev_args args;
805 struct tuntap_softc *tp;
806 int error;
807
808 tp = malloc(sizeof(*tp), M_TUN, M_WAITOK | M_ZERO);
809 mtx_init(&tp->tun_mtx, "tun_mtx", NULL, MTX_DEF);
810 cv_init(&tp->tun_cv, "tun_condvar");
811 tp->tun_flags = drv->ident_flags;
812 tp->tun_drv = drv;
813
814 make_dev_args_init(&args);
815 if (cr != NULL)
816 args.mda_flags = MAKEDEV_REF | MAKEDEV_CHECKNAME;
817 args.mda_devsw = &drv->cdevsw;
818 args.mda_cr = cr;
819 args.mda_uid = UID_UUCP;
820 args.mda_gid = GID_DIALER;
821 args.mda_mode = 0600;
822 args.mda_unit = unit;
823 args.mda_si_drv1 = tp;
824 error = make_dev_s(&args, dev, "%s", name);
825 if (error != 0) {
826 free(tp, M_TUN);
827 return (error);
828 }
829
830 KASSERT((*dev)->si_drv1 != NULL,
831 ("Failed to set si_drv1 at %s creation", name));
832 tp->tun_dev = *dev;
833 knlist_init_mtx(&tp->tun_rsel.si_note, &tp->tun_mtx);
834 mtx_lock(&tunmtx);
835 TAILQ_INSERT_TAIL(&tunhead, tp, tun_list);
836 mtx_unlock(&tunmtx);
837 return (0);
838 }
839
840 static void
tunstart(struct ifnet * ifp)841 tunstart(struct ifnet *ifp)
842 {
843 struct tuntap_softc *tp = ifp->if_softc;
844 struct mbuf *m;
845
846 TUNDEBUG(ifp, "starting\n");
847 if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
848 IFQ_LOCK(&ifp->if_snd);
849 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
850 if (m == NULL) {
851 IFQ_UNLOCK(&ifp->if_snd);
852 return;
853 }
854 IFQ_UNLOCK(&ifp->if_snd);
855 }
856
857 TUN_LOCK(tp);
858 if (tp->tun_flags & TUN_RWAIT) {
859 tp->tun_flags &= ~TUN_RWAIT;
860 wakeup(tp);
861 }
862 selwakeuppri(&tp->tun_rsel, PZERO + 1);
863 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
864 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) {
865 TUN_UNLOCK(tp);
866 pgsigio(&tp->tun_sigio, SIGIO, 0);
867 } else
868 TUN_UNLOCK(tp);
869 }
870
871 /*
872 * tunstart_l2
873 *
874 * queue packets from higher level ready to put out
875 */
876 static void
tunstart_l2(struct ifnet * ifp)877 tunstart_l2(struct ifnet *ifp)
878 {
879 struct tuntap_softc *tp = ifp->if_softc;
880
881 TUNDEBUG(ifp, "starting\n");
882
883 /*
884 * do not junk pending output if we are in VMnet mode.
885 * XXX: can this do any harm because of queue overflow?
886 */
887
888 TUN_LOCK(tp);
889 if (((tp->tun_flags & TUN_VMNET) == 0) &&
890 ((tp->tun_flags & TUN_READY) != TUN_READY)) {
891 struct mbuf *m;
892
893 /* Unlocked read. */
894 TUNDEBUG(ifp, "not ready, tun_flags = 0x%x\n", tp->tun_flags);
895
896 for (;;) {
897 IF_DEQUEUE(&ifp->if_snd, m);
898 if (m != NULL) {
899 m_freem(m);
900 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
901 } else
902 break;
903 }
904 TUN_UNLOCK(tp);
905
906 return;
907 }
908
909 ifp->if_drv_flags |= IFF_DRV_OACTIVE;
910
911 if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
912 if (tp->tun_flags & TUN_RWAIT) {
913 tp->tun_flags &= ~TUN_RWAIT;
914 wakeup(tp);
915 }
916
917 if ((tp->tun_flags & TUN_ASYNC) && (tp->tun_sigio != NULL)) {
918 TUN_UNLOCK(tp);
919 pgsigio(&tp->tun_sigio, SIGIO, 0);
920 TUN_LOCK(tp);
921 }
922
923 selwakeuppri(&tp->tun_rsel, PZERO+1);
924 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
925 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); /* obytes are counted in ether_output */
926 }
927
928 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
929 TUN_UNLOCK(tp);
930 } /* tunstart_l2 */
931
932 static int
tap_transmit(struct ifnet * ifp,struct mbuf * m)933 tap_transmit(struct ifnet *ifp, struct mbuf *m)
934 {
935 int error;
936
937 BPF_MTAP(ifp, m);
938 IFQ_HANDOFF(ifp, m, error);
939 return (error);
940 }
941
942 /* XXX: should return an error code so it can fail. */
943 static void
tuncreate(struct cdev * dev)944 tuncreate(struct cdev *dev)
945 {
946 struct tuntap_driver *drv;
947 struct tuntap_softc *tp;
948 struct ifnet *ifp;
949 struct ether_addr eaddr;
950 int iflags;
951 u_char type;
952
953 tp = dev->si_drv1;
954 KASSERT(tp != NULL,
955 ("si_drv1 should have been initialized at creation"));
956
957 drv = tp->tun_drv;
958 iflags = IFF_MULTICAST;
959 if ((tp->tun_flags & TUN_L2) != 0) {
960 type = IFT_ETHER;
961 iflags |= IFF_BROADCAST | IFF_SIMPLEX;
962 } else {
963 type = IFT_PPP;
964 iflags |= IFF_POINTOPOINT;
965 }
966 ifp = tp->tun_ifp = if_alloc(type);
967 ifp->if_softc = tp;
968 if_initname(ifp, drv->cdevsw.d_name, dev2unit(dev));
969 ifp->if_ioctl = tunifioctl;
970 ifp->if_flags = iflags;
971 IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
972 ifp->if_capabilities |= IFCAP_LINKSTATE;
973 if ((tp->tun_flags & TUN_L2) != 0)
974 ifp->if_capabilities |=
975 IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6 | IFCAP_LRO;
976 ifp->if_capenable |= IFCAP_LINKSTATE;
977
978 if ((tp->tun_flags & TUN_L2) != 0) {
979 ifp->if_init = tunifinit;
980 ifp->if_start = tunstart_l2;
981 ifp->if_transmit = tap_transmit;
982 ifp->if_qflush = if_qflush;
983
984 ether_gen_addr(ifp, &eaddr);
985 ether_ifattach(ifp, eaddr.octet);
986 } else {
987 ifp->if_mtu = TUNMTU;
988 ifp->if_start = tunstart;
989 ifp->if_output = tunoutput;
990
991 ifp->if_snd.ifq_drv_maxlen = 0;
992 IFQ_SET_READY(&ifp->if_snd);
993
994 if_attach(ifp);
995 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
996 }
997
998 TUN_LOCK(tp);
999 tp->tun_flags |= TUN_INITED;
1000 TUN_UNLOCK(tp);
1001
1002 TUNDEBUG(ifp, "interface %s is created, minor = %#x\n",
1003 ifp->if_xname, dev2unit(dev));
1004 }
1005
1006 static void
tunrename(void * arg __unused,struct ifnet * ifp)1007 tunrename(void *arg __unused, struct ifnet *ifp)
1008 {
1009 struct tuntap_softc *tp;
1010 int error;
1011
1012 if ((ifp->if_flags & IFF_RENAMING) == 0)
1013 return;
1014
1015 if (tuntap_driver_from_ifnet(ifp) == NULL)
1016 return;
1017
1018 /*
1019 * We need to grab the ioctl sx long enough to make sure the softc is
1020 * still there. If it is, we can safely try to busy the tun device.
1021 * The busy may fail if the device is currently dying, in which case
1022 * we do nothing. If it doesn't fail, the busy count stops the device
1023 * from dying until we've created the alias (that will then be
1024 * subsequently destroyed).
1025 */
1026 sx_xlock(&tun_ioctl_sx);
1027 tp = ifp->if_softc;
1028 if (tp == NULL) {
1029 sx_xunlock(&tun_ioctl_sx);
1030 return;
1031 }
1032 error = tun_busy(tp);
1033 sx_xunlock(&tun_ioctl_sx);
1034 if (error != 0)
1035 return;
1036 if (tp->tun_alias != NULL) {
1037 destroy_dev(tp->tun_alias);
1038 tp->tun_alias = NULL;
1039 }
1040
1041 if (strcmp(ifp->if_xname, tp->tun_dev->si_name) == 0)
1042 goto out;
1043
1044 /*
1045 * Failure's ok, aliases are created on a best effort basis. If a
1046 * tun user/consumer decides to rename the interface to conflict with
1047 * another device (non-ifnet) on the system, we will assume they know
1048 * what they are doing. make_dev_alias_p won't touch tun_alias on
1049 * failure, so we use it but ignore the return value.
1050 */
1051 make_dev_alias_p(MAKEDEV_CHECKNAME, &tp->tun_alias, tp->tun_dev, "%s",
1052 ifp->if_xname);
1053 out:
1054 tun_unbusy(tp);
1055 }
1056
1057 static int
tunopen(struct cdev * dev,int flag,int mode,struct thread * td)1058 tunopen(struct cdev *dev, int flag, int mode, struct thread *td)
1059 {
1060 struct ifnet *ifp;
1061 struct tuntap_softc *tp;
1062 int error, tunflags;
1063
1064 tunflags = 0;
1065 CURVNET_SET(TD_TO_VNET(td));
1066 error = tuntap_name2info(dev->si_name, NULL, &tunflags);
1067 if (error != 0) {
1068 CURVNET_RESTORE();
1069 return (error); /* Shouldn't happen */
1070 }
1071
1072 tp = dev->si_drv1;
1073 KASSERT(tp != NULL,
1074 ("si_drv1 should have been initialized at creation"));
1075
1076 TUN_LOCK(tp);
1077 if ((tp->tun_flags & TUN_INITED) == 0) {
1078 TUN_UNLOCK(tp);
1079 CURVNET_RESTORE();
1080 return (ENXIO);
1081 }
1082 if ((tp->tun_flags & (TUN_OPEN | TUN_DYING)) != 0) {
1083 TUN_UNLOCK(tp);
1084 CURVNET_RESTORE();
1085 return (EBUSY);
1086 }
1087
1088 error = tun_busy_locked(tp);
1089 KASSERT(error == 0, ("Must be able to busy an unopen tunnel"));
1090 ifp = TUN2IFP(tp);
1091
1092 if ((tp->tun_flags & TUN_L2) != 0) {
1093 bcopy(IF_LLADDR(ifp), tp->tun_ether.octet,
1094 sizeof(tp->tun_ether.octet));
1095
1096 ifp->if_drv_flags |= IFF_DRV_RUNNING;
1097 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1098
1099 if (tapuponopen)
1100 ifp->if_flags |= IFF_UP;
1101 }
1102
1103 tp->tun_pid = td->td_proc->p_pid;
1104 tp->tun_flags |= TUN_OPEN;
1105
1106 if_link_state_change(ifp, LINK_STATE_UP);
1107 TUNDEBUG(ifp, "open\n");
1108 TUN_UNLOCK(tp);
1109
1110 /*
1111 * This can fail with either ENOENT or EBUSY. This is in the middle of
1112 * d_open, so ENOENT should not be possible. EBUSY is possible, but
1113 * the only cdevpriv dtor being set will be tundtor and the softc being
1114 * passed is constant for a given cdev. We ignore the possible error
1115 * because of this as either "unlikely" or "not actually a problem."
1116 */
1117 (void)devfs_set_cdevpriv(tp, tundtor);
1118 CURVNET_RESTORE();
1119 return (0);
1120 }
1121
1122 /*
1123 * tundtor - tear down the device - mark i/f down & delete
1124 * routing info
1125 */
1126 static void
tundtor(void * data)1127 tundtor(void *data)
1128 {
1129 struct proc *p;
1130 struct tuntap_softc *tp;
1131 struct ifnet *ifp;
1132 bool l2tun;
1133
1134 tp = data;
1135 p = curproc;
1136 ifp = TUN2IFP(tp);
1137
1138 TUN_LOCK(tp);
1139
1140 /*
1141 * Realistically, we can't be obstinate here. This only means that the
1142 * tuntap device was closed out of order, and the last closer wasn't the
1143 * controller. These are still good to know about, though, as software
1144 * should avoid multiple processes with a tuntap device open and
1145 * ill-defined transfer of control (e.g., handoff, TUNSIFPID, close in
1146 * parent).
1147 */
1148 if (p->p_pid != tp->tun_pid) {
1149 log(LOG_INFO,
1150 "pid %d (%s), %s: tun/tap protocol violation, non-controlling process closed last.\n",
1151 p->p_pid, p->p_comm, tp->tun_dev->si_name);
1152 }
1153
1154 /*
1155 * junk all pending output
1156 */
1157 CURVNET_SET(ifp->if_vnet);
1158
1159 l2tun = false;
1160 if ((tp->tun_flags & TUN_L2) != 0) {
1161 l2tun = true;
1162 IF_DRAIN(&ifp->if_snd);
1163 } else {
1164 IFQ_PURGE(&ifp->if_snd);
1165 }
1166
1167 /* For vmnet, we won't do most of the address/route bits */
1168 if ((tp->tun_flags & TUN_VMNET) != 0 ||
1169 (l2tun && (ifp->if_flags & IFF_LINK0) != 0))
1170 goto out;
1171 #if defined(INET) || defined(INET6)
1172 if (l2tun && tp->tun_lro_ready) {
1173 TUNDEBUG (ifp, "LRO disabled\n");
1174 tcp_lro_free(&tp->tun_lro);
1175 tp->tun_lro_ready = false;
1176 }
1177 #endif
1178 if (ifp->if_flags & IFF_UP) {
1179 TUN_UNLOCK(tp);
1180 if_down(ifp);
1181 TUN_LOCK(tp);
1182 }
1183
1184 /* Delete all addresses and routes which reference this interface. */
1185 if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
1186 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1187 TUN_UNLOCK(tp);
1188 if_purgeaddrs(ifp);
1189 TUN_LOCK(tp);
1190 }
1191
1192 out:
1193 if_link_state_change(ifp, LINK_STATE_DOWN);
1194 CURVNET_RESTORE();
1195
1196 funsetown(&tp->tun_sigio);
1197 selwakeuppri(&tp->tun_rsel, PZERO + 1);
1198 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
1199 TUNDEBUG (ifp, "closed\n");
1200 tp->tun_flags &= ~TUN_OPEN;
1201 tp->tun_pid = 0;
1202 tun_vnethdr_set(ifp, 0);
1203
1204 tun_unbusy_locked(tp);
1205 TUN_UNLOCK(tp);
1206 }
1207
1208 static void
tuninit(struct ifnet * ifp)1209 tuninit(struct ifnet *ifp)
1210 {
1211 struct tuntap_softc *tp = ifp->if_softc;
1212
1213 TUNDEBUG(ifp, "tuninit\n");
1214
1215 TUN_LOCK(tp);
1216 ifp->if_drv_flags |= IFF_DRV_RUNNING;
1217 if ((tp->tun_flags & TUN_L2) == 0) {
1218 ifp->if_flags |= IFF_UP;
1219 getmicrotime(&ifp->if_lastchange);
1220 TUN_UNLOCK(tp);
1221 } else {
1222 #if defined(INET) || defined(INET6)
1223 if (tcp_lro_init(&tp->tun_lro) == 0) {
1224 TUNDEBUG(ifp, "LRO enabled\n");
1225 tp->tun_lro.ifp = ifp;
1226 tp->tun_lro_ready = true;
1227 } else {
1228 TUNDEBUG(ifp, "Could not enable LRO\n");
1229 tp->tun_lro_ready = false;
1230 }
1231 #endif
1232 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1233 TUN_UNLOCK(tp);
1234 /* attempt to start output */
1235 tunstart_l2(ifp);
1236 }
1237
1238 }
1239
1240 /*
1241 * Used only for l2 tunnel.
1242 */
1243 static void
tunifinit(void * xtp)1244 tunifinit(void *xtp)
1245 {
1246 struct tuntap_softc *tp;
1247
1248 tp = (struct tuntap_softc *)xtp;
1249 tuninit(tp->tun_ifp);
1250 }
1251
1252 /*
1253 * To be called under TUN_LOCK. Update ifp->if_hwassist according to the
1254 * current value of ifp->if_capenable.
1255 */
1256 static void
tun_caps_changed(struct ifnet * ifp)1257 tun_caps_changed(struct ifnet *ifp)
1258 {
1259 uint64_t hwassist = 0;
1260
1261 TUN_LOCK_ASSERT((struct tuntap_softc *)ifp->if_softc);
1262 if (ifp->if_capenable & IFCAP_TXCSUM)
1263 hwassist |= CSUM_TCP | CSUM_UDP;
1264 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
1265 hwassist |= CSUM_TCP_IPV6
1266 | CSUM_UDP_IPV6;
1267 if (ifp->if_capenable & IFCAP_TSO4)
1268 hwassist |= CSUM_IP_TSO;
1269 if (ifp->if_capenable & IFCAP_TSO6)
1270 hwassist |= CSUM_IP6_TSO;
1271 ifp->if_hwassist = hwassist;
1272 }
1273
1274 /*
1275 * To be called under TUN_LOCK. Update tp->tun_vhdrlen and adjust
1276 * if_capabilities and if_capenable as needed.
1277 */
1278 static void
tun_vnethdr_set(struct ifnet * ifp,int vhdrlen)1279 tun_vnethdr_set(struct ifnet *ifp, int vhdrlen)
1280 {
1281 struct tuntap_softc *tp = ifp->if_softc;
1282
1283 TUN_LOCK_ASSERT(tp);
1284
1285 if (tp->tun_vhdrlen == vhdrlen)
1286 return;
1287
1288 /*
1289 * Update if_capabilities to reflect the
1290 * functionalities offered by the virtio-net
1291 * header.
1292 */
1293 if (vhdrlen != 0)
1294 ifp->if_capabilities |=
1295 TAP_VNET_HDR_CAPS;
1296 else
1297 ifp->if_capabilities &=
1298 ~TAP_VNET_HDR_CAPS;
1299 /*
1300 * Disable any capabilities that we don't
1301 * support anymore.
1302 */
1303 ifp->if_capenable &= ifp->if_capabilities;
1304 tun_caps_changed(ifp);
1305 tp->tun_vhdrlen = vhdrlen;
1306
1307 TUNDEBUG(ifp, "vnet_hdr_len=%d, if_capabilities=%x\n",
1308 vhdrlen, ifp->if_capabilities);
1309 }
1310
1311 /*
1312 * Process an ioctl request.
1313 */
1314 static int
tunifioctl(struct ifnet * ifp,u_long cmd,caddr_t data)1315 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1316 {
1317 struct ifreq *ifr = (struct ifreq *)data;
1318 struct tuntap_softc *tp;
1319 struct ifstat *ifs;
1320 struct ifmediareq *ifmr;
1321 int dummy, error = 0;
1322 bool l2tun;
1323
1324 ifmr = NULL;
1325 sx_xlock(&tun_ioctl_sx);
1326 tp = ifp->if_softc;
1327 if (tp == NULL) {
1328 error = ENXIO;
1329 goto bad;
1330 }
1331 l2tun = (tp->tun_flags & TUN_L2) != 0;
1332 switch(cmd) {
1333 case SIOCGIFSTATUS:
1334 ifs = (struct ifstat *)data;
1335 TUN_LOCK(tp);
1336 if (tp->tun_pid)
1337 snprintf(ifs->ascii, sizeof(ifs->ascii),
1338 "\tOpened by PID %d\n", tp->tun_pid);
1339 else
1340 ifs->ascii[0] = '\0';
1341 TUN_UNLOCK(tp);
1342 break;
1343 case SIOCSIFADDR:
1344 if (l2tun)
1345 error = ether_ioctl(ifp, cmd, data);
1346 else
1347 tuninit(ifp);
1348 if (error == 0)
1349 TUNDEBUG(ifp, "address set\n");
1350 break;
1351 case SIOCSIFMTU:
1352 ifp->if_mtu = ifr->ifr_mtu;
1353 TUNDEBUG(ifp, "mtu set\n");
1354 break;
1355 case SIOCSIFFLAGS:
1356 case SIOCADDMULTI:
1357 case SIOCDELMULTI:
1358 break;
1359 case SIOCGIFMEDIA:
1360 if (!l2tun) {
1361 error = EINVAL;
1362 break;
1363 }
1364
1365 ifmr = (struct ifmediareq *)data;
1366 dummy = ifmr->ifm_count;
1367 ifmr->ifm_count = 1;
1368 ifmr->ifm_status = IFM_AVALID;
1369 ifmr->ifm_active = IFM_ETHER;
1370 if (tp->tun_flags & TUN_OPEN)
1371 ifmr->ifm_status |= IFM_ACTIVE;
1372 ifmr->ifm_current = ifmr->ifm_active;
1373 if (dummy >= 1) {
1374 int media = IFM_ETHER;
1375 error = copyout(&media, ifmr->ifm_ulist, sizeof(int));
1376 }
1377 break;
1378 case SIOCSIFCAP:
1379 TUN_LOCK(tp);
1380 ifp->if_capenable = ifr->ifr_reqcap;
1381 tun_caps_changed(ifp);
1382 TUN_UNLOCK(tp);
1383 VLAN_CAPABILITIES(ifp);
1384 break;
1385 default:
1386 if (l2tun) {
1387 error = ether_ioctl(ifp, cmd, data);
1388 } else {
1389 error = EINVAL;
1390 }
1391 }
1392 bad:
1393 sx_xunlock(&tun_ioctl_sx);
1394 return (error);
1395 }
1396
1397 /*
1398 * tunoutput - queue packets from higher level ready to put out.
1399 */
1400 static int
tunoutput(struct ifnet * ifp,struct mbuf * m0,const struct sockaddr * dst,struct route * ro)1401 tunoutput(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
1402 struct route *ro)
1403 {
1404 struct tuntap_softc *tp = ifp->if_softc;
1405 u_short cached_tun_flags;
1406 int error;
1407 u_int32_t af;
1408
1409 TUNDEBUG (ifp, "tunoutput\n");
1410
1411 #ifdef MAC
1412 error = mac_ifnet_check_transmit(ifp, m0);
1413 if (error) {
1414 m_freem(m0);
1415 return (error);
1416 }
1417 #endif
1418
1419 /* Could be unlocked read? */
1420 TUN_LOCK(tp);
1421 cached_tun_flags = tp->tun_flags;
1422 TUN_UNLOCK(tp);
1423 if ((cached_tun_flags & TUN_READY) != TUN_READY) {
1424 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
1425 m_freem (m0);
1426 return (EHOSTDOWN);
1427 }
1428
1429 if ((ifp->if_flags & IFF_UP) != IFF_UP) {
1430 m_freem (m0);
1431 return (EHOSTDOWN);
1432 }
1433
1434 /* BPF writes need to be handled specially. */
1435 if (dst->sa_family == AF_UNSPEC)
1436 bcopy(dst->sa_data, &af, sizeof(af));
1437 else
1438 af = RO_GET_FAMILY(ro, dst);
1439
1440 BPF_MTAP2(ifp, &af, sizeof(af), m0);
1441
1442 /* prepend sockaddr? this may abort if the mbuf allocation fails */
1443 if (cached_tun_flags & TUN_LMODE) {
1444 /* allocate space for sockaddr */
1445 M_PREPEND(m0, dst->sa_len, M_NOWAIT);
1446
1447 /* if allocation failed drop packet */
1448 if (m0 == NULL) {
1449 if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1450 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1451 return (ENOBUFS);
1452 } else {
1453 bcopy(dst, m0->m_data, dst->sa_len);
1454 }
1455 }
1456
1457 if (cached_tun_flags & TUN_IFHEAD) {
1458 /* Prepend the address family */
1459 M_PREPEND(m0, 4, M_NOWAIT);
1460
1461 /* if allocation failed drop packet */
1462 if (m0 == NULL) {
1463 if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1464 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1465 return (ENOBUFS);
1466 } else
1467 *(u_int32_t *)m0->m_data = htonl(af);
1468 } else {
1469 #ifdef INET
1470 if (af != AF_INET)
1471 #endif
1472 {
1473 m_freem(m0);
1474 return (EAFNOSUPPORT);
1475 }
1476 }
1477
1478 error = (ifp->if_transmit)(ifp, m0);
1479 if (error)
1480 return (ENOBUFS);
1481 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
1482 return (0);
1483 }
1484
1485 /*
1486 * the cdevsw interface is now pretty minimal.
1487 */
1488 static int
tunioctl(struct cdev * dev,u_long cmd,caddr_t data,int flag,struct thread * td)1489 tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag,
1490 struct thread *td)
1491 {
1492 struct ifreq ifr, *ifrp;
1493 struct tuntap_softc *tp = dev->si_drv1;
1494 struct ifnet *ifp = TUN2IFP(tp);
1495 struct tuninfo *tunp;
1496 int error, iflags, ival;
1497 bool l2tun;
1498
1499 l2tun = (tp->tun_flags & TUN_L2) != 0;
1500 if (l2tun) {
1501 /* tap specific ioctls */
1502 switch(cmd) {
1503 /* VMware/VMnet port ioctl's */
1504 #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
1505 defined(COMPAT_FREEBSD4)
1506 case _IO('V', 0):
1507 ival = IOCPARM_IVAL(data);
1508 data = (caddr_t)&ival;
1509 /* FALLTHROUGH */
1510 #endif
1511 case VMIO_SIOCSIFFLAGS: /* VMware/VMnet SIOCSIFFLAGS */
1512 iflags = *(int *)data;
1513 iflags &= TUN_VMIO_FLAG_MASK;
1514 iflags &= ~IFF_CANTCHANGE;
1515 iflags |= IFF_UP;
1516
1517 TUN_LOCK(tp);
1518 ifp->if_flags = iflags |
1519 (ifp->if_flags & IFF_CANTCHANGE);
1520 TUN_UNLOCK(tp);
1521
1522 return (0);
1523 case SIOCGIFADDR: /* get MAC address of the remote side */
1524 TUN_LOCK(tp);
1525 bcopy(&tp->tun_ether.octet, data,
1526 sizeof(tp->tun_ether.octet));
1527 TUN_UNLOCK(tp);
1528
1529 return (0);
1530 case SIOCSIFADDR: /* set MAC address of the remote side */
1531 TUN_LOCK(tp);
1532 bcopy(data, &tp->tun_ether.octet,
1533 sizeof(tp->tun_ether.octet));
1534 TUN_UNLOCK(tp);
1535
1536 return (0);
1537 case TAPSVNETHDR:
1538 ival = *(int *)data;
1539 if (ival != 0 &&
1540 ival != sizeof(struct virtio_net_hdr) &&
1541 ival != sizeof(struct virtio_net_hdr_mrg_rxbuf)) {
1542 return (EINVAL);
1543 }
1544 TUN_LOCK(tp);
1545 tun_vnethdr_set(ifp, ival);
1546 TUN_UNLOCK(tp);
1547
1548 return (0);
1549 case TAPGVNETHDR:
1550 TUN_LOCK(tp);
1551 *(int *)data = tp->tun_vhdrlen;
1552 TUN_UNLOCK(tp);
1553
1554 return (0);
1555 }
1556
1557 /* Fall through to the common ioctls if unhandled */
1558 } else {
1559 switch (cmd) {
1560 case TUNSLMODE:
1561 TUN_LOCK(tp);
1562 if (*(int *)data) {
1563 tp->tun_flags |= TUN_LMODE;
1564 tp->tun_flags &= ~TUN_IFHEAD;
1565 } else
1566 tp->tun_flags &= ~TUN_LMODE;
1567 TUN_UNLOCK(tp);
1568
1569 return (0);
1570 case TUNSIFHEAD:
1571 TUN_LOCK(tp);
1572 if (*(int *)data) {
1573 tp->tun_flags |= TUN_IFHEAD;
1574 tp->tun_flags &= ~TUN_LMODE;
1575 } else
1576 tp->tun_flags &= ~TUN_IFHEAD;
1577 TUN_UNLOCK(tp);
1578
1579 return (0);
1580 case TUNGIFHEAD:
1581 TUN_LOCK(tp);
1582 *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
1583 TUN_UNLOCK(tp);
1584
1585 return (0);
1586 case TUNSIFMODE:
1587 /* deny this if UP */
1588 if (TUN2IFP(tp)->if_flags & IFF_UP)
1589 return (EBUSY);
1590
1591 switch (*(int *)data & ~IFF_MULTICAST) {
1592 case IFF_POINTOPOINT:
1593 case IFF_BROADCAST:
1594 TUN_LOCK(tp);
1595 TUN2IFP(tp)->if_flags &=
1596 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
1597 TUN2IFP(tp)->if_flags |= *(int *)data;
1598 TUN_UNLOCK(tp);
1599
1600 break;
1601 default:
1602 return (EINVAL);
1603 }
1604
1605 return (0);
1606 case TUNSIFPID:
1607 TUN_LOCK(tp);
1608 tp->tun_pid = curthread->td_proc->p_pid;
1609 TUN_UNLOCK(tp);
1610
1611 return (0);
1612 }
1613 /* Fall through to the common ioctls if unhandled */
1614 }
1615
1616 switch (cmd) {
1617 case TUNGIFNAME:
1618 ifrp = (struct ifreq *)data;
1619 strlcpy(ifrp->ifr_name, TUN2IFP(tp)->if_xname, IFNAMSIZ);
1620
1621 return (0);
1622 case TUNSIFINFO:
1623 tunp = (struct tuninfo *)data;
1624 if (TUN2IFP(tp)->if_type != tunp->type)
1625 return (EPROTOTYPE);
1626 TUN_LOCK(tp);
1627 if (TUN2IFP(tp)->if_mtu != tunp->mtu) {
1628 strlcpy(ifr.ifr_name, if_name(TUN2IFP(tp)), IFNAMSIZ);
1629 ifr.ifr_mtu = tunp->mtu;
1630 CURVNET_SET(TUN2IFP(tp)->if_vnet);
1631 error = ifhwioctl(SIOCSIFMTU, TUN2IFP(tp),
1632 (caddr_t)&ifr, td);
1633 CURVNET_RESTORE();
1634 if (error) {
1635 TUN_UNLOCK(tp);
1636 return (error);
1637 }
1638 }
1639 TUN2IFP(tp)->if_baudrate = tunp->baudrate;
1640 TUN_UNLOCK(tp);
1641 break;
1642 case TUNGIFINFO:
1643 tunp = (struct tuninfo *)data;
1644 TUN_LOCK(tp);
1645 tunp->mtu = TUN2IFP(tp)->if_mtu;
1646 tunp->type = TUN2IFP(tp)->if_type;
1647 tunp->baudrate = TUN2IFP(tp)->if_baudrate;
1648 TUN_UNLOCK(tp);
1649 break;
1650 case TUNSDEBUG:
1651 tundebug = *(int *)data;
1652 break;
1653 case TUNGDEBUG:
1654 *(int *)data = tundebug;
1655 break;
1656 case FIONBIO:
1657 break;
1658 case FIOASYNC:
1659 TUN_LOCK(tp);
1660 if (*(int *)data)
1661 tp->tun_flags |= TUN_ASYNC;
1662 else
1663 tp->tun_flags &= ~TUN_ASYNC;
1664 TUN_UNLOCK(tp);
1665 break;
1666 case FIONREAD:
1667 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) {
1668 struct mbuf *mb;
1669 IFQ_LOCK(&TUN2IFP(tp)->if_snd);
1670 IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb);
1671 for (*(int *)data = 0; mb != NULL; mb = mb->m_next)
1672 *(int *)data += mb->m_len;
1673 IFQ_UNLOCK(&TUN2IFP(tp)->if_snd);
1674 } else
1675 *(int *)data = 0;
1676 break;
1677 case FIOSETOWN:
1678 return (fsetown(*(int *)data, &tp->tun_sigio));
1679
1680 case FIOGETOWN:
1681 *(int *)data = fgetown(&tp->tun_sigio);
1682 return (0);
1683
1684 /* This is deprecated, FIOSETOWN should be used instead. */
1685 case TIOCSPGRP:
1686 return (fsetown(-(*(int *)data), &tp->tun_sigio));
1687
1688 /* This is deprecated, FIOGETOWN should be used instead. */
1689 case TIOCGPGRP:
1690 *(int *)data = -fgetown(&tp->tun_sigio);
1691 return (0);
1692
1693 default:
1694 return (ENOTTY);
1695 }
1696 return (0);
1697 }
1698
1699 /*
1700 * The cdevsw read interface - reads a packet at a time, or at
1701 * least as much of a packet as can be read.
1702 */
1703 static int
tunread(struct cdev * dev,struct uio * uio,int flag)1704 tunread(struct cdev *dev, struct uio *uio, int flag)
1705 {
1706 struct tuntap_softc *tp = dev->si_drv1;
1707 struct ifnet *ifp = TUN2IFP(tp);
1708 struct mbuf *m;
1709 size_t len;
1710 int error = 0;
1711
1712 TUNDEBUG (ifp, "read\n");
1713 TUN_LOCK(tp);
1714 if ((tp->tun_flags & TUN_READY) != TUN_READY) {
1715 TUN_UNLOCK(tp);
1716 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
1717 return (EHOSTDOWN);
1718 }
1719
1720 tp->tun_flags &= ~TUN_RWAIT;
1721
1722 for (;;) {
1723 IFQ_DEQUEUE(&ifp->if_snd, m);
1724 if (m != NULL)
1725 break;
1726 if (flag & O_NONBLOCK) {
1727 TUN_UNLOCK(tp);
1728 return (EWOULDBLOCK);
1729 }
1730 tp->tun_flags |= TUN_RWAIT;
1731 error = mtx_sleep(tp, &tp->tun_mtx, PCATCH | (PZERO + 1),
1732 "tunread", 0);
1733 if (error != 0) {
1734 TUN_UNLOCK(tp);
1735 return (error);
1736 }
1737 }
1738 TUN_UNLOCK(tp);
1739
1740 len = min(tp->tun_vhdrlen, uio->uio_resid);
1741 if (len > 0) {
1742 struct virtio_net_hdr_mrg_rxbuf vhdr;
1743
1744 bzero(&vhdr, sizeof(vhdr));
1745 if (m->m_pkthdr.csum_flags & TAP_ALL_OFFLOAD) {
1746 m = virtio_net_tx_offload(ifp, m, false, &vhdr.hdr);
1747 }
1748
1749 TUNDEBUG(ifp, "txvhdr: f %u, gt %u, hl %u, "
1750 "gs %u, cs %u, co %u\n", vhdr.hdr.flags,
1751 vhdr.hdr.gso_type, vhdr.hdr.hdr_len,
1752 vhdr.hdr.gso_size, vhdr.hdr.csum_start,
1753 vhdr.hdr.csum_offset);
1754 error = uiomove(&vhdr, len, uio);
1755 }
1756
1757 while (m && uio->uio_resid > 0 && error == 0) {
1758 len = min(uio->uio_resid, m->m_len);
1759 if (len != 0)
1760 error = uiomove(mtod(m, void *), len, uio);
1761 m = m_free(m);
1762 }
1763
1764 if (m) {
1765 TUNDEBUG(ifp, "Dropping mbuf\n");
1766 m_freem(m);
1767 }
1768 return (error);
1769 }
1770
1771 static int
tunwrite_l2(struct tuntap_softc * tp,struct mbuf * m,struct virtio_net_hdr_mrg_rxbuf * vhdr)1772 tunwrite_l2(struct tuntap_softc *tp, struct mbuf *m,
1773 struct virtio_net_hdr_mrg_rxbuf *vhdr)
1774 {
1775 struct epoch_tracker et;
1776 struct ether_header *eh;
1777 struct ifnet *ifp;
1778
1779 ifp = TUN2IFP(tp);
1780
1781 /*
1782 * Only pass a unicast frame to ether_input(), if it would
1783 * actually have been received by non-virtual hardware.
1784 */
1785 if (m->m_len < sizeof(struct ether_header)) {
1786 m_freem(m);
1787 return (0);
1788 }
1789
1790 eh = mtod(m, struct ether_header *);
1791
1792 if ((ifp->if_flags & IFF_PROMISC) == 0 &&
1793 !ETHER_IS_MULTICAST(eh->ether_dhost) &&
1794 bcmp(eh->ether_dhost, IF_LLADDR(ifp), ETHER_ADDR_LEN) != 0) {
1795 m_freem(m);
1796 return (0);
1797 }
1798
1799 if (vhdr != NULL) {
1800 if (virtio_net_rx_csum(m, &vhdr->hdr)) {
1801 m_freem(m);
1802 return (0);
1803 }
1804 } else {
1805 switch (ntohs(eh->ether_type)) {
1806 #ifdef INET
1807 case ETHERTYPE_IP:
1808 if (ifp->if_capenable & IFCAP_RXCSUM) {
1809 m->m_pkthdr.csum_flags |=
1810 CSUM_IP_CHECKED | CSUM_IP_VALID |
1811 CSUM_DATA_VALID | CSUM_SCTP_VALID |
1812 CSUM_PSEUDO_HDR;
1813 m->m_pkthdr.csum_data = 0xffff;
1814 }
1815 break;
1816 #endif
1817 #ifdef INET6
1818 case ETHERTYPE_IPV6:
1819 if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) {
1820 m->m_pkthdr.csum_flags |=
1821 CSUM_DATA_VALID_IPV6 | CSUM_SCTP_VALID |
1822 CSUM_PSEUDO_HDR;
1823 m->m_pkthdr.csum_data = 0xffff;
1824 }
1825 break;
1826 #endif
1827 }
1828 }
1829
1830 /* Pass packet up to parent. */
1831 CURVNET_SET(ifp->if_vnet);
1832 NET_EPOCH_ENTER(et);
1833 #if defined(INET) || defined(INET6)
1834 if (tp->tun_lro_ready && ifp->if_capenable & IFCAP_LRO &&
1835 tcp_lro_rx(&tp->tun_lro, m, 0) == 0)
1836 tcp_lro_flush_all(&tp->tun_lro);
1837 else
1838 #endif
1839 (*ifp->if_input)(ifp, m);
1840 NET_EPOCH_EXIT(et);
1841 CURVNET_RESTORE();
1842 /* ibytes are counted in parent */
1843 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1844 return (0);
1845 }
1846
1847 static int
tunwrite_l3(struct tuntap_softc * tp,struct mbuf * m)1848 tunwrite_l3(struct tuntap_softc *tp, struct mbuf *m)
1849 {
1850 struct epoch_tracker et;
1851 struct ifnet *ifp;
1852 int family, isr;
1853
1854 ifp = TUN2IFP(tp);
1855 /* Could be unlocked read? */
1856 TUN_LOCK(tp);
1857 if (tp->tun_flags & TUN_IFHEAD) {
1858 TUN_UNLOCK(tp);
1859 if (m->m_len < sizeof(family) &&
1860 (m = m_pullup(m, sizeof(family))) == NULL)
1861 return (ENOBUFS);
1862 family = ntohl(*mtod(m, u_int32_t *));
1863 m_adj(m, sizeof(family));
1864 } else {
1865 TUN_UNLOCK(tp);
1866 family = AF_INET;
1867 }
1868
1869 BPF_MTAP2(ifp, &family, sizeof(family), m);
1870
1871 switch (family) {
1872 #ifdef INET
1873 case AF_INET:
1874 isr = NETISR_IP;
1875 break;
1876 #endif
1877 #ifdef INET6
1878 case AF_INET6:
1879 isr = NETISR_IPV6;
1880 break;
1881 #endif
1882 default:
1883 m_freem(m);
1884 return (EAFNOSUPPORT);
1885 }
1886 random_harvest_queue(m, sizeof(*m), RANDOM_NET_TUN);
1887 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
1888 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1889 CURVNET_SET(ifp->if_vnet);
1890 M_SETFIB(m, ifp->if_fib);
1891 NET_EPOCH_ENTER(et);
1892 netisr_dispatch(isr, m);
1893 NET_EPOCH_EXIT(et);
1894 CURVNET_RESTORE();
1895 return (0);
1896 }
1897
1898 /*
1899 * the cdevsw write interface - an atomic write is a packet - or else!
1900 */
1901 static int
tunwrite(struct cdev * dev,struct uio * uio,int flag)1902 tunwrite(struct cdev *dev, struct uio *uio, int flag)
1903 {
1904 struct virtio_net_hdr_mrg_rxbuf vhdr;
1905 struct tuntap_softc *tp;
1906 struct ifnet *ifp;
1907 struct mbuf *m;
1908 uint32_t mru;
1909 int align, vhdrlen, error;
1910 bool l2tun;
1911
1912 tp = dev->si_drv1;
1913 ifp = TUN2IFP(tp);
1914 TUNDEBUG(ifp, "tunwrite\n");
1915 if ((ifp->if_flags & IFF_UP) != IFF_UP)
1916 /* ignore silently */
1917 return (0);
1918
1919 if (uio->uio_resid == 0)
1920 return (0);
1921
1922 l2tun = (tp->tun_flags & TUN_L2) != 0;
1923 mru = l2tun ? TAPMRU : TUNMRU;
1924 vhdrlen = tp->tun_vhdrlen;
1925 align = 0;
1926 if (l2tun) {
1927 align = ETHER_ALIGN;
1928 mru += vhdrlen;
1929 } else if ((tp->tun_flags & TUN_IFHEAD) != 0)
1930 mru += sizeof(uint32_t); /* family */
1931 if (uio->uio_resid < 0 || uio->uio_resid > mru) {
1932 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid);
1933 return (EIO);
1934 }
1935
1936 if (vhdrlen > 0) {
1937 error = uiomove(&vhdr, vhdrlen, uio);
1938 if (error != 0)
1939 return (error);
1940 TUNDEBUG(ifp, "txvhdr: f %u, gt %u, hl %u, "
1941 "gs %u, cs %u, co %u\n", vhdr.hdr.flags,
1942 vhdr.hdr.gso_type, vhdr.hdr.hdr_len,
1943 vhdr.hdr.gso_size, vhdr.hdr.csum_start,
1944 vhdr.hdr.csum_offset);
1945 }
1946
1947 if ((m = m_uiotombuf(uio, M_NOWAIT, 0, align, M_PKTHDR)) == NULL) {
1948 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
1949 return (ENOBUFS);
1950 }
1951
1952 m->m_pkthdr.rcvif = ifp;
1953 #ifdef MAC
1954 mac_ifnet_create_mbuf(ifp, m);
1955 #endif
1956
1957 if (l2tun)
1958 return (tunwrite_l2(tp, m, vhdrlen > 0 ? &vhdr : NULL));
1959
1960 return (tunwrite_l3(tp, m));
1961 }
1962
1963 /*
1964 * tunpoll - the poll interface, this is only useful on reads
1965 * really. The write detect always returns true, write never blocks
1966 * anyway, it either accepts the packet or drops it.
1967 */
1968 static int
tunpoll(struct cdev * dev,int events,struct thread * td)1969 tunpoll(struct cdev *dev, int events, struct thread *td)
1970 {
1971 struct tuntap_softc *tp = dev->si_drv1;
1972 struct ifnet *ifp = TUN2IFP(tp);
1973 int revents = 0;
1974
1975 TUNDEBUG(ifp, "tunpoll\n");
1976
1977 if (events & (POLLIN | POLLRDNORM)) {
1978 IFQ_LOCK(&ifp->if_snd);
1979 if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
1980 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len);
1981 revents |= events & (POLLIN | POLLRDNORM);
1982 } else {
1983 TUNDEBUG(ifp, "tunpoll waiting\n");
1984 selrecord(td, &tp->tun_rsel);
1985 }
1986 IFQ_UNLOCK(&ifp->if_snd);
1987 }
1988 revents |= events & (POLLOUT | POLLWRNORM);
1989
1990 return (revents);
1991 }
1992
1993 /*
1994 * tunkqfilter - support for the kevent() system call.
1995 */
1996 static int
tunkqfilter(struct cdev * dev,struct knote * kn)1997 tunkqfilter(struct cdev *dev, struct knote *kn)
1998 {
1999 struct tuntap_softc *tp = dev->si_drv1;
2000 struct ifnet *ifp = TUN2IFP(tp);
2001
2002 switch(kn->kn_filter) {
2003 case EVFILT_READ:
2004 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n",
2005 ifp->if_xname, dev2unit(dev));
2006 kn->kn_fop = &tun_read_filterops;
2007 break;
2008
2009 case EVFILT_WRITE:
2010 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n",
2011 ifp->if_xname, dev2unit(dev));
2012 kn->kn_fop = &tun_write_filterops;
2013 break;
2014
2015 default:
2016 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n",
2017 ifp->if_xname, dev2unit(dev));
2018 return(EINVAL);
2019 }
2020
2021 kn->kn_hook = tp;
2022 knlist_add(&tp->tun_rsel.si_note, kn, 0);
2023
2024 return (0);
2025 }
2026
2027 /*
2028 * Return true of there is data in the interface queue.
2029 */
2030 static int
tunkqread(struct knote * kn,long hint)2031 tunkqread(struct knote *kn, long hint)
2032 {
2033 int ret;
2034 struct tuntap_softc *tp = kn->kn_hook;
2035 struct cdev *dev = tp->tun_dev;
2036 struct ifnet *ifp = TUN2IFP(tp);
2037
2038 if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) {
2039 TUNDEBUG(ifp,
2040 "%s have data in the queue. Len = %d, minor = %#x\n",
2041 ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev));
2042 ret = 1;
2043 } else {
2044 TUNDEBUG(ifp,
2045 "%s waiting for data, minor = %#x\n", ifp->if_xname,
2046 dev2unit(dev));
2047 ret = 0;
2048 }
2049
2050 return (ret);
2051 }
2052
2053 /*
2054 * Always can write, always return MTU in kn->data.
2055 */
2056 static int
tunkqwrite(struct knote * kn,long hint)2057 tunkqwrite(struct knote *kn, long hint)
2058 {
2059 struct tuntap_softc *tp = kn->kn_hook;
2060 struct ifnet *ifp = TUN2IFP(tp);
2061
2062 kn->kn_data = ifp->if_mtu;
2063
2064 return (1);
2065 }
2066
2067 static void
tunkqdetach(struct knote * kn)2068 tunkqdetach(struct knote *kn)
2069 {
2070 struct tuntap_softc *tp = kn->kn_hook;
2071
2072 knlist_remove(&tp->tun_rsel.si_note, kn, 0);
2073 }
2074