1 /* $NetBSD: if_tun.c,v 1.14 1994/06/29 06:36:25 cgd Exp $ */
2 /*-
3 * SPDX-License-Identifier: BSD-2-Clause
4 *
5 * Copyright (C) 1999-2000 by Maksim Yevmenkin <m_evmenkin@yahoo.com>
6 * All rights reserved.
7 * Copyright (c) 2019 Kyle Evans <kevans@FreeBSD.org>
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * BASED ON:
32 * -------------------------------------------------------------------------
33 *
34 * Copyright (c) 1988, Julian Onions <jpo@cs.nott.ac.uk>
35 * Nottingham University 1987.
36 *
37 * This source may be freely distributed, however I would be interested
38 * in any changes that are made.
39 *
40 * This driver takes packets off the IP i/f and hands them up to a
41 * user process to have its wicked way with. This driver has it's
42 * roots in a similar driver written by Phil Cockcroft (formerly) at
43 * UCL. This driver is based much more on read/write/poll mode of
44 * operation though.
45 */
46
47 #include "opt_inet.h"
48 #include "opt_inet6.h"
49
50 #include <sys/param.h>
51 #include <sys/lock.h>
52 #include <sys/priv.h>
53 #include <sys/proc.h>
54 #include <sys/systm.h>
55 #include <sys/jail.h>
56 #include <sys/mbuf.h>
57 #include <sys/module.h>
58 #include <sys/socket.h>
59 #include <sys/eventhandler.h>
60 #include <sys/fcntl.h>
61 #include <sys/filio.h>
62 #include <sys/sockio.h>
63 #include <sys/sx.h>
64 #include <sys/syslog.h>
65 #include <sys/ttycom.h>
66 #include <sys/poll.h>
67 #include <sys/selinfo.h>
68 #include <sys/signalvar.h>
69 #include <sys/filedesc.h>
70 #include <sys/kernel.h>
71 #include <sys/sysctl.h>
72 #include <sys/conf.h>
73 #include <sys/uio.h>
74 #include <sys/malloc.h>
75 #include <sys/random.h>
76 #include <sys/ctype.h>
77
78 #include <net/ethernet.h>
79 #include <net/if.h>
80 #include <net/if_var.h>
81 #include <net/if_clone.h>
82 #include <net/if_dl.h>
83 #include <net/if_media.h>
84 #include <net/if_private.h>
85 #include <net/if_types.h>
86 #include <net/if_vlan_var.h>
87 #include <net/netisr.h>
88 #include <net/route.h>
89 #include <net/vnet.h>
90 #include <netinet/in.h>
91 #ifdef INET
92 #include <netinet/ip.h>
93 #endif
94 #ifdef INET6
95 #include <netinet/ip6.h>
96 #include <netinet6/ip6_var.h>
97 #endif
98 #include <netinet/udp.h>
99 #include <netinet/tcp.h>
100 #include <netinet/tcp_lro.h>
101 #include <net/bpf.h>
102 #include <net/if_tap.h>
103 #include <net/if_tun.h>
104
105 #include <dev/virtio/network/virtio_net.h>
106
107 #include <sys/queue.h>
108 #include <sys/condvar.h>
109 #include <security/mac/mac_framework.h>
110
111 struct tuntap_driver;
112
113 /*
114 * tun_list is protected by global tunmtx. Other mutable fields are
115 * protected by tun->tun_mtx, or by their owning subsystem. tun_dev is
116 * static for the duration of a tunnel interface.
117 */
118 struct tuntap_softc {
119 TAILQ_ENTRY(tuntap_softc) tun_list;
120 struct cdev *tun_alias;
121 struct cdev *tun_dev;
122 u_short tun_flags; /* misc flags */
123 #define TUN_OPEN 0x0001
124 #define TUN_INITED 0x0002
125 #define TUN_UNUSED1 0x0008
126 #define TUN_UNUSED2 0x0010
127 #define TUN_LMODE 0x0020
128 #define TUN_RWAIT 0x0040
129 #define TUN_ASYNC 0x0080
130 #define TUN_IFHEAD 0x0100
131 #define TUN_DYING 0x0200
132 #define TUN_L2 0x0400
133 #define TUN_VMNET 0x0800
134
135 #define TUN_DRIVER_IDENT_MASK (TUN_L2 | TUN_VMNET)
136 #define TUN_READY (TUN_OPEN | TUN_INITED)
137
138 pid_t tun_pid; /* owning pid */
139 struct ifnet *tun_ifp; /* the interface */
140 struct sigio *tun_sigio; /* async I/O info */
141 struct tuntap_driver *tun_drv; /* appropriate driver */
142 struct selinfo tun_rsel; /* read select */
143 struct mtx tun_mtx; /* softc field mutex */
144 struct cv tun_cv; /* for ref'd dev destroy */
145 struct ether_addr tun_ether; /* remote address */
146 int tun_busy; /* busy count */
147 int tun_vhdrlen; /* virtio-net header length */
148 struct lro_ctrl tun_lro; /* for TCP LRO */
149 bool tun_lro_ready; /* TCP LRO initialized */
150 };
151 #define TUN2IFP(sc) ((sc)->tun_ifp)
152
153 #define TUNDEBUG if (tundebug) if_printf
154
155 #define TUN_LOCK(tp) mtx_lock(&(tp)->tun_mtx)
156 #define TUN_UNLOCK(tp) mtx_unlock(&(tp)->tun_mtx)
157 #define TUN_LOCK_ASSERT(tp) mtx_assert(&(tp)->tun_mtx, MA_OWNED);
158
159 #define TUN_VMIO_FLAG_MASK 0x0fff
160
161 /*
162 * Interface capabilities of a tap device that supports the virtio-net
163 * header.
164 */
165 #define TAP_VNET_HDR_CAPS (IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6 \
166 | IFCAP_VLAN_HWCSUM \
167 | IFCAP_TSO | IFCAP_LRO \
168 | IFCAP_VLAN_HWTSO)
169
170 #define TAP_ALL_OFFLOAD (CSUM_TSO | CSUM_TCP | CSUM_UDP |\
171 CSUM_TCP_IPV6 | CSUM_UDP_IPV6)
172
173 /*
174 * All mutable global variables in if_tun are locked using tunmtx, with
175 * the exception of tundebug, which is used unlocked, and the drivers' *clones,
176 * which are static after setup.
177 */
178 static struct mtx tunmtx;
179 static eventhandler_tag arrival_tag;
180 static eventhandler_tag clone_tag;
181 static const char tunname[] = "tun";
182 static const char tapname[] = "tap";
183 static const char vmnetname[] = "vmnet";
184 static MALLOC_DEFINE(M_TUN, tunname, "Tunnel Interface");
185 static int tundebug = 0;
186 static int tundclone = 1;
187 static int tap_allow_uopen = 0; /* allow user devfs cloning */
188 static int tapuponopen = 0; /* IFF_UP on open() */
189 static int tapdclone = 1; /* enable devfs cloning */
190
191 static TAILQ_HEAD(,tuntap_softc) tunhead = TAILQ_HEAD_INITIALIZER(tunhead);
192 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");
193
194 static struct sx tun_ioctl_sx;
195 SX_SYSINIT(tun_ioctl_sx, &tun_ioctl_sx, "tun_ioctl");
196
197 SYSCTL_DECL(_net_link);
198 /* tun */
199 static SYSCTL_NODE(_net_link, OID_AUTO, tun, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
200 "IP tunnel software network interface");
201 SYSCTL_INT(_net_link_tun, OID_AUTO, devfs_cloning, CTLFLAG_RWTUN, &tundclone, 0,
202 "Enable legacy devfs interface creation");
203
204 /* tap */
205 static SYSCTL_NODE(_net_link, OID_AUTO, tap, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
206 "Ethernet tunnel software network interface");
207 SYSCTL_INT(_net_link_tap, OID_AUTO, user_open, CTLFLAG_RW, &tap_allow_uopen, 0,
208 "Enable legacy devfs interface creation for all users");
209 SYSCTL_INT(_net_link_tap, OID_AUTO, up_on_open, CTLFLAG_RW, &tapuponopen, 0,
210 "Bring interface up when /dev/tap is opened");
211 SYSCTL_INT(_net_link_tap, OID_AUTO, devfs_cloning, CTLFLAG_RWTUN, &tapdclone, 0,
212 "Enable legacy devfs interface creation");
213 SYSCTL_INT(_net_link_tap, OID_AUTO, debug, CTLFLAG_RW, &tundebug, 0, "");
214
215 static int tun_create_device(struct tuntap_driver *drv, int unit,
216 struct ucred *cr, struct cdev **dev, const char *name);
217 static int tun_busy_locked(struct tuntap_softc *tp);
218 static void tun_unbusy_locked(struct tuntap_softc *tp);
219 static int tun_busy(struct tuntap_softc *tp);
220 static void tun_unbusy(struct tuntap_softc *tp);
221
222 static int tuntap_name2info(const char *name, int *unit, int *flags);
223 static void tunclone(void *arg, struct ucred *cred, char *name,
224 int namelen, struct cdev **dev);
225 static void tuncreate(struct cdev *dev);
226 static void tundtor(void *data);
227 static void tunrename(void *arg, struct ifnet *ifp);
228 static int tunifioctl(struct ifnet *, u_long, caddr_t);
229 static void tuninit(struct ifnet *);
230 static void tunifinit(void *xtp);
231 static int tuntapmodevent(module_t, int, void *);
232 static int tunoutput(struct ifnet *, struct mbuf *,
233 const struct sockaddr *, struct route *ro);
234 static void tunstart(struct ifnet *);
235 static void tunstart_l2(struct ifnet *);
236
237 static int tun_clone_match(struct if_clone *ifc, const char *name);
238 static int tap_clone_match(struct if_clone *ifc, const char *name);
239 static int vmnet_clone_match(struct if_clone *ifc, const char *name);
240 static int tun_clone_create(struct if_clone *, char *, size_t,
241 struct ifc_data *, struct ifnet **);
242 static int tun_clone_destroy(struct if_clone *, struct ifnet *, uint32_t);
243 static void tun_vnethdr_set(struct ifnet *ifp, int vhdrlen);
244
245 static d_open_t tunopen;
246 static d_read_t tunread;
247 static d_write_t tunwrite;
248 static d_ioctl_t tunioctl;
249 static d_poll_t tunpoll;
250 static d_kqfilter_t tunkqfilter;
251
252 static int tunkqread(struct knote *, long);
253 static int tunkqwrite(struct knote *, long);
254 static void tunkqdetach(struct knote *);
255
256 static struct filterops tun_read_filterops = {
257 .f_isfd = 1,
258 .f_attach = NULL,
259 .f_detach = tunkqdetach,
260 .f_event = tunkqread,
261 };
262
263 static struct filterops tun_write_filterops = {
264 .f_isfd = 1,
265 .f_attach = NULL,
266 .f_detach = tunkqdetach,
267 .f_event = tunkqwrite,
268 };
269
270 static struct tuntap_driver {
271 struct cdevsw cdevsw;
272 int ident_flags;
273 struct unrhdr *unrhdr;
274 struct clonedevs *clones;
275 ifc_match_f *clone_match_fn;
276 ifc_create_f *clone_create_fn;
277 ifc_destroy_f *clone_destroy_fn;
278 } tuntap_drivers[] = {
279 {
280 .ident_flags = 0,
281 .cdevsw = {
282 .d_version = D_VERSION,
283 .d_flags = D_NEEDMINOR,
284 .d_open = tunopen,
285 .d_read = tunread,
286 .d_write = tunwrite,
287 .d_ioctl = tunioctl,
288 .d_poll = tunpoll,
289 .d_kqfilter = tunkqfilter,
290 .d_name = tunname,
291 },
292 .clone_match_fn = tun_clone_match,
293 .clone_create_fn = tun_clone_create,
294 .clone_destroy_fn = tun_clone_destroy,
295 },
296 {
297 .ident_flags = TUN_L2,
298 .cdevsw = {
299 .d_version = D_VERSION,
300 .d_flags = D_NEEDMINOR,
301 .d_open = tunopen,
302 .d_read = tunread,
303 .d_write = tunwrite,
304 .d_ioctl = tunioctl,
305 .d_poll = tunpoll,
306 .d_kqfilter = tunkqfilter,
307 .d_name = tapname,
308 },
309 .clone_match_fn = tap_clone_match,
310 .clone_create_fn = tun_clone_create,
311 .clone_destroy_fn = tun_clone_destroy,
312 },
313 {
314 .ident_flags = TUN_L2 | TUN_VMNET,
315 .cdevsw = {
316 .d_version = D_VERSION,
317 .d_flags = D_NEEDMINOR,
318 .d_open = tunopen,
319 .d_read = tunread,
320 .d_write = tunwrite,
321 .d_ioctl = tunioctl,
322 .d_poll = tunpoll,
323 .d_kqfilter = tunkqfilter,
324 .d_name = vmnetname,
325 },
326 .clone_match_fn = vmnet_clone_match,
327 .clone_create_fn = tun_clone_create,
328 .clone_destroy_fn = tun_clone_destroy,
329 },
330 };
331 #define NDRV nitems(tuntap_drivers)
332
333 VNET_DEFINE_STATIC(struct if_clone *, tuntap_driver_cloners[NDRV]);
334 #define V_tuntap_driver_cloners VNET(tuntap_driver_cloners)
335
336 /*
337 * Mechanism for marking a tunnel device as busy so that we can safely do some
338 * orthogonal operations (such as operations on devices) without racing against
339 * tun_destroy. tun_destroy will wait on the condvar if we're at all busy or
340 * open, to be woken up when the condition is alleviated.
341 */
342 static int
tun_busy_locked(struct tuntap_softc * tp)343 tun_busy_locked(struct tuntap_softc *tp)
344 {
345
346 TUN_LOCK_ASSERT(tp);
347 if ((tp->tun_flags & TUN_DYING) != 0) {
348 /*
349 * Perhaps unintuitive, but the device is busy going away.
350 * Other interpretations of EBUSY from tun_busy make little
351 * sense, since making a busy device even more busy doesn't
352 * sound like a problem.
353 */
354 return (EBUSY);
355 }
356
357 ++tp->tun_busy;
358 return (0);
359 }
360
361 static void
tun_unbusy_locked(struct tuntap_softc * tp)362 tun_unbusy_locked(struct tuntap_softc *tp)
363 {
364
365 TUN_LOCK_ASSERT(tp);
366 KASSERT(tp->tun_busy != 0, ("tun_unbusy: called for non-busy tunnel"));
367
368 --tp->tun_busy;
369 /* Wake up anything that may be waiting on our busy tunnel. */
370 if (tp->tun_busy == 0)
371 cv_broadcast(&tp->tun_cv);
372 }
373
374 static int
tun_busy(struct tuntap_softc * tp)375 tun_busy(struct tuntap_softc *tp)
376 {
377 int ret;
378
379 TUN_LOCK(tp);
380 ret = tun_busy_locked(tp);
381 TUN_UNLOCK(tp);
382 return (ret);
383 }
384
385 static void
tun_unbusy(struct tuntap_softc * tp)386 tun_unbusy(struct tuntap_softc *tp)
387 {
388
389 TUN_LOCK(tp);
390 tun_unbusy_locked(tp);
391 TUN_UNLOCK(tp);
392 }
393
394 /*
395 * Sets unit and/or flags given the device name. Must be called with correct
396 * vnet context.
397 */
398 static int
tuntap_name2info(const char * name,int * outunit,int * outflags)399 tuntap_name2info(const char *name, int *outunit, int *outflags)
400 {
401 struct tuntap_driver *drv;
402 char *dname;
403 int flags, unit;
404 bool found;
405
406 if (name == NULL)
407 return (EINVAL);
408
409 /*
410 * Needed for dev_stdclone, but dev_stdclone will not modify, it just
411 * wants to be able to pass back a char * through the second param. We
412 * will always set that as NULL here, so we'll fake it.
413 */
414 dname = __DECONST(char *, name);
415 found = false;
416
417 for (u_int i = 0; i < NDRV; i++) {
418 drv = &tuntap_drivers[i];
419
420 if (strcmp(name, drv->cdevsw.d_name) == 0) {
421 found = true;
422 unit = -1;
423 flags = drv->ident_flags;
424 break;
425 }
426
427 if (dev_stdclone(dname, NULL, drv->cdevsw.d_name, &unit) == 1) {
428 found = true;
429 flags = drv->ident_flags;
430 break;
431 }
432 }
433
434 if (!found)
435 return (ENXIO);
436
437 if (outunit != NULL)
438 *outunit = unit;
439 if (outflags != NULL)
440 *outflags = flags;
441 return (0);
442 }
443
444 /*
445 * Get driver information from a set of flags specified. Masks the identifying
446 * part of the flags and compares it against all of the available
447 * tuntap_drivers.
448 */
449 static struct tuntap_driver *
tuntap_driver_from_flags(int tun_flags)450 tuntap_driver_from_flags(int tun_flags)
451 {
452
453 for (u_int i = 0; i < NDRV; i++)
454 if ((tun_flags & TUN_DRIVER_IDENT_MASK) ==
455 tuntap_drivers[i].ident_flags)
456 return (&tuntap_drivers[i]);
457
458 return (NULL);
459 }
460
461 static int
tun_clone_match(struct if_clone * ifc,const char * name)462 tun_clone_match(struct if_clone *ifc, const char *name)
463 {
464 int tunflags;
465
466 if (tuntap_name2info(name, NULL, &tunflags) == 0) {
467 if ((tunflags & TUN_L2) == 0)
468 return (1);
469 }
470
471 return (0);
472 }
473
474 static int
tap_clone_match(struct if_clone * ifc,const char * name)475 tap_clone_match(struct if_clone *ifc, const char *name)
476 {
477 int tunflags;
478
479 if (tuntap_name2info(name, NULL, &tunflags) == 0) {
480 if ((tunflags & (TUN_L2 | TUN_VMNET)) == TUN_L2)
481 return (1);
482 }
483
484 return (0);
485 }
486
487 static int
vmnet_clone_match(struct if_clone * ifc,const char * name)488 vmnet_clone_match(struct if_clone *ifc, const char *name)
489 {
490 int tunflags;
491
492 if (tuntap_name2info(name, NULL, &tunflags) == 0) {
493 if ((tunflags & TUN_VMNET) != 0)
494 return (1);
495 }
496
497 return (0);
498 }
499
500 static int
tun_clone_create(struct if_clone * ifc,char * name,size_t len,struct ifc_data * ifd,struct ifnet ** ifpp)501 tun_clone_create(struct if_clone *ifc, char *name, size_t len,
502 struct ifc_data *ifd, struct ifnet **ifpp)
503 {
504 struct tuntap_driver *drv;
505 struct cdev *dev;
506 int err, i, tunflags, unit;
507
508 tunflags = 0;
509 /* The name here tells us exactly what we're creating */
510 err = tuntap_name2info(name, &unit, &tunflags);
511 if (err != 0)
512 return (err);
513
514 drv = tuntap_driver_from_flags(tunflags);
515 if (drv == NULL)
516 return (ENXIO);
517
518 if (unit != -1) {
519 /* If this unit number is still available that's okay. */
520 if (alloc_unr_specific(drv->unrhdr, unit) == -1)
521 return (EEXIST);
522 } else {
523 unit = alloc_unr(drv->unrhdr);
524 }
525
526 snprintf(name, IFNAMSIZ, "%s%d", drv->cdevsw.d_name, unit);
527
528 /* find any existing device, or allocate new unit number */
529 dev = NULL;
530 i = clone_create(&drv->clones, &drv->cdevsw, &unit, &dev, 0);
531 /* No preexisting struct cdev *, create one */
532 if (i != 0)
533 i = tun_create_device(drv, unit, NULL, &dev, name);
534 if (i == 0) {
535 dev_ref(dev);
536 tuncreate(dev);
537 struct tuntap_softc *tp = dev->si_drv1;
538 *ifpp = tp->tun_ifp;
539 }
540
541 return (i);
542 }
543
544 static void
tunclone(void * arg,struct ucred * cred,char * name,int namelen,struct cdev ** dev)545 tunclone(void *arg, struct ucred *cred, char *name, int namelen,
546 struct cdev **dev)
547 {
548 char devname[SPECNAMELEN + 1];
549 struct tuntap_driver *drv;
550 int append_unit, i, u, tunflags;
551 bool mayclone;
552
553 if (*dev != NULL)
554 return;
555
556 tunflags = 0;
557 CURVNET_SET(CRED_TO_VNET(cred));
558 if (tuntap_name2info(name, &u, &tunflags) != 0)
559 goto out; /* Not recognized */
560
561 if (u != -1 && u > IF_MAXUNIT)
562 goto out; /* Unit number too high */
563
564 mayclone = priv_check_cred(cred, PRIV_NET_IFCREATE) == 0;
565 if ((tunflags & TUN_L2) != 0) {
566 /* tap/vmnet allow user open with a sysctl */
567 mayclone = (mayclone || tap_allow_uopen) && tapdclone;
568 } else {
569 mayclone = mayclone && tundclone;
570 }
571
572 /*
573 * If tun cloning is enabled, only the superuser can create an
574 * interface.
575 */
576 if (!mayclone)
577 goto out;
578
579 if (u == -1)
580 append_unit = 1;
581 else
582 append_unit = 0;
583
584 drv = tuntap_driver_from_flags(tunflags);
585 if (drv == NULL)
586 goto out;
587
588 /* find any existing device, or allocate new unit number */
589 i = clone_create(&drv->clones, &drv->cdevsw, &u, dev, 0);
590 if (i) {
591 if (append_unit) {
592 namelen = snprintf(devname, sizeof(devname), "%s%d",
593 name, u);
594 name = devname;
595 }
596
597 i = tun_create_device(drv, u, cred, dev, name);
598 }
599 if (i == 0) {
600 dev_ref(*dev);
601 if_clone_create(name, namelen, NULL);
602 }
603 out:
604 CURVNET_RESTORE();
605 }
606
607 static void
tun_destroy(struct tuntap_softc * tp)608 tun_destroy(struct tuntap_softc *tp)
609 {
610
611 TUN_LOCK(tp);
612 tp->tun_flags |= TUN_DYING;
613 if (tp->tun_busy != 0)
614 cv_wait_unlock(&tp->tun_cv, &tp->tun_mtx);
615 else
616 TUN_UNLOCK(tp);
617
618 CURVNET_SET(TUN2IFP(tp)->if_vnet);
619
620 /* destroy_dev will take care of any alias. */
621 destroy_dev(tp->tun_dev);
622 seldrain(&tp->tun_rsel);
623 knlist_clear(&tp->tun_rsel.si_note, 0);
624 knlist_destroy(&tp->tun_rsel.si_note);
625 if ((tp->tun_flags & TUN_L2) != 0) {
626 ether_ifdetach(TUN2IFP(tp));
627 } else {
628 bpfdetach(TUN2IFP(tp));
629 if_detach(TUN2IFP(tp));
630 }
631 sx_xlock(&tun_ioctl_sx);
632 TUN2IFP(tp)->if_softc = NULL;
633 sx_xunlock(&tun_ioctl_sx);
634 free_unr(tp->tun_drv->unrhdr, TUN2IFP(tp)->if_dunit);
635 if_free(TUN2IFP(tp));
636 mtx_destroy(&tp->tun_mtx);
637 cv_destroy(&tp->tun_cv);
638 free(tp, M_TUN);
639 CURVNET_RESTORE();
640 }
641
642 static int
tun_clone_destroy(struct if_clone * ifc __unused,struct ifnet * ifp,uint32_t flags)643 tun_clone_destroy(struct if_clone *ifc __unused, struct ifnet *ifp, uint32_t flags)
644 {
645 struct tuntap_softc *tp = ifp->if_softc;
646
647 mtx_lock(&tunmtx);
648 TAILQ_REMOVE(&tunhead, tp, tun_list);
649 mtx_unlock(&tunmtx);
650 tun_destroy(tp);
651
652 return (0);
653 }
654
655 static void
vnet_tun_init(const void * unused __unused)656 vnet_tun_init(const void *unused __unused)
657 {
658
659 for (u_int i = 0; i < NDRV; ++i) {
660 struct if_clone_addreq req = {
661 .match_f = tuntap_drivers[i].clone_match_fn,
662 .create_f = tuntap_drivers[i].clone_create_fn,
663 .destroy_f = tuntap_drivers[i].clone_destroy_fn,
664 };
665 V_tuntap_driver_cloners[i] =
666 ifc_attach_cloner(tuntap_drivers[i].cdevsw.d_name, &req);
667 };
668 }
669 VNET_SYSINIT(vnet_tun_init, SI_SUB_PROTO_IF, SI_ORDER_ANY,
670 vnet_tun_init, NULL);
671
672 static void
vnet_tun_uninit(const void * unused __unused)673 vnet_tun_uninit(const void *unused __unused)
674 {
675
676 for (u_int i = 0; i < NDRV; ++i)
677 if_clone_detach(V_tuntap_driver_cloners[i]);
678 }
679 VNET_SYSUNINIT(vnet_tun_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY,
680 vnet_tun_uninit, NULL);
681
682 static void
tun_uninit(const void * unused __unused)683 tun_uninit(const void *unused __unused)
684 {
685 struct tuntap_driver *drv;
686 struct tuntap_softc *tp;
687 int i;
688
689 EVENTHANDLER_DEREGISTER(ifnet_arrival_event, arrival_tag);
690 EVENTHANDLER_DEREGISTER(dev_clone, clone_tag);
691
692 mtx_lock(&tunmtx);
693 while ((tp = TAILQ_FIRST(&tunhead)) != NULL) {
694 TAILQ_REMOVE(&tunhead, tp, tun_list);
695 mtx_unlock(&tunmtx);
696 tun_destroy(tp);
697 mtx_lock(&tunmtx);
698 }
699 mtx_unlock(&tunmtx);
700 for (i = 0; i < nitems(tuntap_drivers); ++i) {
701 drv = &tuntap_drivers[i];
702 delete_unrhdr(drv->unrhdr);
703 clone_cleanup(&drv->clones);
704 }
705 mtx_destroy(&tunmtx);
706 }
707 SYSUNINIT(tun_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY, tun_uninit, NULL);
708
709 static struct tuntap_driver *
tuntap_driver_from_ifnet(const struct ifnet * ifp)710 tuntap_driver_from_ifnet(const struct ifnet *ifp)
711 {
712 struct tuntap_driver *drv;
713 int i;
714
715 if (ifp == NULL)
716 return (NULL);
717
718 for (i = 0; i < nitems(tuntap_drivers); ++i) {
719 drv = &tuntap_drivers[i];
720 if (strcmp(ifp->if_dname, drv->cdevsw.d_name) == 0)
721 return (drv);
722 }
723
724 return (NULL);
725 }
726
727 static int
tuntapmodevent(module_t mod,int type,void * data)728 tuntapmodevent(module_t mod, int type, void *data)
729 {
730 struct tuntap_driver *drv;
731 int i;
732
733 switch (type) {
734 case MOD_LOAD:
735 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF);
736 for (i = 0; i < nitems(tuntap_drivers); ++i) {
737 drv = &tuntap_drivers[i];
738 clone_setup(&drv->clones);
739 drv->unrhdr = new_unrhdr(0, IF_MAXUNIT, &tunmtx);
740 }
741 arrival_tag = EVENTHANDLER_REGISTER(ifnet_arrival_event,
742 tunrename, 0, 1000);
743 if (arrival_tag == NULL)
744 return (ENOMEM);
745 clone_tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000);
746 if (clone_tag == NULL)
747 return (ENOMEM);
748 break;
749 case MOD_UNLOAD:
750 /* See tun_uninit, so it's done after the vnet_sysuninit() */
751 break;
752 default:
753 return EOPNOTSUPP;
754 }
755 return 0;
756 }
757
758 static moduledata_t tuntap_mod = {
759 "if_tuntap",
760 tuntapmodevent,
761 0
762 };
763
764 /* We'll only ever have these two, so no need for a macro. */
765 static moduledata_t tun_mod = { "if_tun", NULL, 0 };
766 static moduledata_t tap_mod = { "if_tap", NULL, 0 };
767
768 DECLARE_MODULE(if_tuntap, tuntap_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
769 MODULE_VERSION(if_tuntap, 1);
770 DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
771 MODULE_VERSION(if_tun, 1);
772 DECLARE_MODULE(if_tap, tap_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
773 MODULE_VERSION(if_tap, 1);
774
775 static int
tun_create_device(struct tuntap_driver * drv,int unit,struct ucred * cr,struct cdev ** dev,const char * name)776 tun_create_device(struct tuntap_driver *drv, int unit, struct ucred *cr,
777 struct cdev **dev, const char *name)
778 {
779 struct make_dev_args args;
780 struct tuntap_softc *tp;
781 int error;
782
783 tp = malloc(sizeof(*tp), M_TUN, M_WAITOK | M_ZERO);
784 mtx_init(&tp->tun_mtx, "tun_mtx", NULL, MTX_DEF);
785 cv_init(&tp->tun_cv, "tun_condvar");
786 tp->tun_flags = drv->ident_flags;
787 tp->tun_drv = drv;
788
789 make_dev_args_init(&args);
790 if (cr != NULL)
791 args.mda_flags = MAKEDEV_REF | MAKEDEV_CHECKNAME;
792 args.mda_devsw = &drv->cdevsw;
793 args.mda_cr = cr;
794 args.mda_uid = UID_UUCP;
795 args.mda_gid = GID_DIALER;
796 args.mda_mode = 0600;
797 args.mda_unit = unit;
798 args.mda_si_drv1 = tp;
799 error = make_dev_s(&args, dev, "%s", name);
800 if (error != 0) {
801 free(tp, M_TUN);
802 return (error);
803 }
804
805 KASSERT((*dev)->si_drv1 != NULL,
806 ("Failed to set si_drv1 at %s creation", name));
807 tp->tun_dev = *dev;
808 knlist_init_mtx(&tp->tun_rsel.si_note, &tp->tun_mtx);
809 mtx_lock(&tunmtx);
810 TAILQ_INSERT_TAIL(&tunhead, tp, tun_list);
811 mtx_unlock(&tunmtx);
812 return (0);
813 }
814
815 static void
tunstart(struct ifnet * ifp)816 tunstart(struct ifnet *ifp)
817 {
818 struct tuntap_softc *tp = ifp->if_softc;
819 struct mbuf *m;
820
821 TUNDEBUG(ifp, "starting\n");
822 if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
823 IFQ_LOCK(&ifp->if_snd);
824 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
825 if (m == NULL) {
826 IFQ_UNLOCK(&ifp->if_snd);
827 return;
828 }
829 IFQ_UNLOCK(&ifp->if_snd);
830 }
831
832 TUN_LOCK(tp);
833 if (tp->tun_flags & TUN_RWAIT) {
834 tp->tun_flags &= ~TUN_RWAIT;
835 wakeup(tp);
836 }
837 selwakeuppri(&tp->tun_rsel, PZERO + 1);
838 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
839 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) {
840 TUN_UNLOCK(tp);
841 pgsigio(&tp->tun_sigio, SIGIO, 0);
842 } else
843 TUN_UNLOCK(tp);
844 }
845
846 /*
847 * tunstart_l2
848 *
849 * queue packets from higher level ready to put out
850 */
851 static void
tunstart_l2(struct ifnet * ifp)852 tunstart_l2(struct ifnet *ifp)
853 {
854 struct tuntap_softc *tp = ifp->if_softc;
855
856 TUNDEBUG(ifp, "starting\n");
857
858 /*
859 * do not junk pending output if we are in VMnet mode.
860 * XXX: can this do any harm because of queue overflow?
861 */
862
863 TUN_LOCK(tp);
864 if (((tp->tun_flags & TUN_VMNET) == 0) &&
865 ((tp->tun_flags & TUN_READY) != TUN_READY)) {
866 struct mbuf *m;
867
868 /* Unlocked read. */
869 TUNDEBUG(ifp, "not ready, tun_flags = 0x%x\n", tp->tun_flags);
870
871 for (;;) {
872 IF_DEQUEUE(&ifp->if_snd, m);
873 if (m != NULL) {
874 m_freem(m);
875 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
876 } else
877 break;
878 }
879 TUN_UNLOCK(tp);
880
881 return;
882 }
883
884 ifp->if_drv_flags |= IFF_DRV_OACTIVE;
885
886 if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
887 if (tp->tun_flags & TUN_RWAIT) {
888 tp->tun_flags &= ~TUN_RWAIT;
889 wakeup(tp);
890 }
891
892 if ((tp->tun_flags & TUN_ASYNC) && (tp->tun_sigio != NULL)) {
893 TUN_UNLOCK(tp);
894 pgsigio(&tp->tun_sigio, SIGIO, 0);
895 TUN_LOCK(tp);
896 }
897
898 selwakeuppri(&tp->tun_rsel, PZERO+1);
899 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
900 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); /* obytes are counted in ether_output */
901 }
902
903 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
904 TUN_UNLOCK(tp);
905 } /* tunstart_l2 */
906
907 static int
tap_transmit(struct ifnet * ifp,struct mbuf * m)908 tap_transmit(struct ifnet *ifp, struct mbuf *m)
909 {
910 int error;
911
912 BPF_MTAP(ifp, m);
913 IFQ_HANDOFF(ifp, m, error);
914 return (error);
915 }
916
917 /* XXX: should return an error code so it can fail. */
918 static void
tuncreate(struct cdev * dev)919 tuncreate(struct cdev *dev)
920 {
921 struct tuntap_driver *drv;
922 struct tuntap_softc *tp;
923 struct ifnet *ifp;
924 struct ether_addr eaddr;
925 int iflags;
926 u_char type;
927
928 tp = dev->si_drv1;
929 KASSERT(tp != NULL,
930 ("si_drv1 should have been initialized at creation"));
931
932 drv = tp->tun_drv;
933 iflags = IFF_MULTICAST;
934 if ((tp->tun_flags & TUN_L2) != 0) {
935 type = IFT_ETHER;
936 iflags |= IFF_BROADCAST | IFF_SIMPLEX;
937 } else {
938 type = IFT_PPP;
939 iflags |= IFF_POINTOPOINT;
940 }
941 ifp = tp->tun_ifp = if_alloc(type);
942 if (ifp == NULL)
943 panic("%s%d: failed to if_alloc() interface.\n",
944 drv->cdevsw.d_name, dev2unit(dev));
945 ifp->if_softc = tp;
946 if_initname(ifp, drv->cdevsw.d_name, dev2unit(dev));
947 ifp->if_ioctl = tunifioctl;
948 ifp->if_flags = iflags;
949 IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
950 ifp->if_capabilities |= IFCAP_LINKSTATE;
951 if ((tp->tun_flags & TUN_L2) != 0)
952 ifp->if_capabilities |=
953 IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6 | IFCAP_LRO;
954 ifp->if_capenable |= IFCAP_LINKSTATE;
955
956 if ((tp->tun_flags & TUN_L2) != 0) {
957 ifp->if_init = tunifinit;
958 ifp->if_start = tunstart_l2;
959 ifp->if_transmit = tap_transmit;
960 ifp->if_qflush = if_qflush;
961
962 ether_gen_addr(ifp, &eaddr);
963 ether_ifattach(ifp, eaddr.octet);
964 } else {
965 ifp->if_mtu = TUNMTU;
966 ifp->if_start = tunstart;
967 ifp->if_output = tunoutput;
968
969 ifp->if_snd.ifq_drv_maxlen = 0;
970 IFQ_SET_READY(&ifp->if_snd);
971
972 if_attach(ifp);
973 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
974 }
975
976 TUN_LOCK(tp);
977 tp->tun_flags |= TUN_INITED;
978 TUN_UNLOCK(tp);
979
980 TUNDEBUG(ifp, "interface %s is created, minor = %#x\n",
981 ifp->if_xname, dev2unit(dev));
982 }
983
984 static void
tunrename(void * arg __unused,struct ifnet * ifp)985 tunrename(void *arg __unused, struct ifnet *ifp)
986 {
987 struct tuntap_softc *tp;
988 int error;
989
990 if ((ifp->if_flags & IFF_RENAMING) == 0)
991 return;
992
993 if (tuntap_driver_from_ifnet(ifp) == NULL)
994 return;
995
996 /*
997 * We need to grab the ioctl sx long enough to make sure the softc is
998 * still there. If it is, we can safely try to busy the tun device.
999 * The busy may fail if the device is currently dying, in which case
1000 * we do nothing. If it doesn't fail, the busy count stops the device
1001 * from dying until we've created the alias (that will then be
1002 * subsequently destroyed).
1003 */
1004 sx_xlock(&tun_ioctl_sx);
1005 tp = ifp->if_softc;
1006 if (tp == NULL) {
1007 sx_xunlock(&tun_ioctl_sx);
1008 return;
1009 }
1010 error = tun_busy(tp);
1011 sx_xunlock(&tun_ioctl_sx);
1012 if (error != 0)
1013 return;
1014 if (tp->tun_alias != NULL) {
1015 destroy_dev(tp->tun_alias);
1016 tp->tun_alias = NULL;
1017 }
1018
1019 if (strcmp(ifp->if_xname, tp->tun_dev->si_name) == 0)
1020 goto out;
1021
1022 /*
1023 * Failure's ok, aliases are created on a best effort basis. If a
1024 * tun user/consumer decides to rename the interface to conflict with
1025 * another device (non-ifnet) on the system, we will assume they know
1026 * what they are doing. make_dev_alias_p won't touch tun_alias on
1027 * failure, so we use it but ignore the return value.
1028 */
1029 make_dev_alias_p(MAKEDEV_CHECKNAME, &tp->tun_alias, tp->tun_dev, "%s",
1030 ifp->if_xname);
1031 out:
1032 tun_unbusy(tp);
1033 }
1034
1035 static int
tunopen(struct cdev * dev,int flag,int mode,struct thread * td)1036 tunopen(struct cdev *dev, int flag, int mode, struct thread *td)
1037 {
1038 struct ifnet *ifp;
1039 struct tuntap_softc *tp;
1040 int error __diagused, tunflags;
1041
1042 tunflags = 0;
1043 CURVNET_SET(TD_TO_VNET(td));
1044 error = tuntap_name2info(dev->si_name, NULL, &tunflags);
1045 if (error != 0) {
1046 CURVNET_RESTORE();
1047 return (error); /* Shouldn't happen */
1048 }
1049
1050 tp = dev->si_drv1;
1051 KASSERT(tp != NULL,
1052 ("si_drv1 should have been initialized at creation"));
1053
1054 TUN_LOCK(tp);
1055 if ((tp->tun_flags & TUN_INITED) == 0) {
1056 TUN_UNLOCK(tp);
1057 CURVNET_RESTORE();
1058 return (ENXIO);
1059 }
1060 if ((tp->tun_flags & (TUN_OPEN | TUN_DYING)) != 0) {
1061 TUN_UNLOCK(tp);
1062 CURVNET_RESTORE();
1063 return (EBUSY);
1064 }
1065
1066 error = tun_busy_locked(tp);
1067 KASSERT(error == 0, ("Must be able to busy an unopen tunnel"));
1068 ifp = TUN2IFP(tp);
1069
1070 if ((tp->tun_flags & TUN_L2) != 0) {
1071 bcopy(IF_LLADDR(ifp), tp->tun_ether.octet,
1072 sizeof(tp->tun_ether.octet));
1073
1074 ifp->if_drv_flags |= IFF_DRV_RUNNING;
1075 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1076
1077 if (tapuponopen)
1078 ifp->if_flags |= IFF_UP;
1079 }
1080
1081 tp->tun_pid = td->td_proc->p_pid;
1082 tp->tun_flags |= TUN_OPEN;
1083
1084 if_link_state_change(ifp, LINK_STATE_UP);
1085 TUNDEBUG(ifp, "open\n");
1086 TUN_UNLOCK(tp);
1087
1088 /*
1089 * This can fail with either ENOENT or EBUSY. This is in the middle of
1090 * d_open, so ENOENT should not be possible. EBUSY is possible, but
1091 * the only cdevpriv dtor being set will be tundtor and the softc being
1092 * passed is constant for a given cdev. We ignore the possible error
1093 * because of this as either "unlikely" or "not actually a problem."
1094 */
1095 (void)devfs_set_cdevpriv(tp, tundtor);
1096 CURVNET_RESTORE();
1097 return (0);
1098 }
1099
1100 /*
1101 * tundtor - tear down the device - mark i/f down & delete
1102 * routing info
1103 */
1104 static void
tundtor(void * data)1105 tundtor(void *data)
1106 {
1107 struct proc *p;
1108 struct tuntap_softc *tp;
1109 struct ifnet *ifp;
1110 bool l2tun;
1111
1112 tp = data;
1113 p = curproc;
1114 ifp = TUN2IFP(tp);
1115
1116 TUN_LOCK(tp);
1117
1118 /*
1119 * Realistically, we can't be obstinate here. This only means that the
1120 * tuntap device was closed out of order, and the last closer wasn't the
1121 * controller. These are still good to know about, though, as software
1122 * should avoid multiple processes with a tuntap device open and
1123 * ill-defined transfer of control (e.g., handoff, TUNSIFPID, close in
1124 * parent).
1125 */
1126 if (p->p_pid != tp->tun_pid) {
1127 log(LOG_INFO,
1128 "pid %d (%s), %s: tun/tap protocol violation, non-controlling process closed last.\n",
1129 p->p_pid, p->p_comm, tp->tun_dev->si_name);
1130 }
1131
1132 /*
1133 * junk all pending output
1134 */
1135 CURVNET_SET(ifp->if_vnet);
1136
1137 l2tun = false;
1138 if ((tp->tun_flags & TUN_L2) != 0) {
1139 l2tun = true;
1140 IF_DRAIN(&ifp->if_snd);
1141 } else {
1142 IFQ_PURGE(&ifp->if_snd);
1143 }
1144
1145 /* For vmnet, we won't do most of the address/route bits */
1146 if ((tp->tun_flags & TUN_VMNET) != 0 ||
1147 (l2tun && (ifp->if_flags & IFF_LINK0) != 0))
1148 goto out;
1149 #if defined(INET) || defined(INET6)
1150 if (l2tun && tp->tun_lro_ready) {
1151 TUNDEBUG (ifp, "LRO disabled\n");
1152 tcp_lro_free(&tp->tun_lro);
1153 tp->tun_lro_ready = false;
1154 }
1155 #endif
1156 if (ifp->if_flags & IFF_UP) {
1157 TUN_UNLOCK(tp);
1158 if_down(ifp);
1159 TUN_LOCK(tp);
1160 }
1161
1162 /* Delete all addresses and routes which reference this interface. */
1163 if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
1164 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1165 TUN_UNLOCK(tp);
1166 if_purgeaddrs(ifp);
1167 TUN_LOCK(tp);
1168 }
1169
1170 out:
1171 if_link_state_change(ifp, LINK_STATE_DOWN);
1172 CURVNET_RESTORE();
1173
1174 funsetown(&tp->tun_sigio);
1175 selwakeuppri(&tp->tun_rsel, PZERO + 1);
1176 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
1177 TUNDEBUG (ifp, "closed\n");
1178 tp->tun_flags &= ~TUN_OPEN;
1179 tp->tun_pid = 0;
1180 tun_vnethdr_set(ifp, 0);
1181
1182 tun_unbusy_locked(tp);
1183 TUN_UNLOCK(tp);
1184 }
1185
1186 static void
tuninit(struct ifnet * ifp)1187 tuninit(struct ifnet *ifp)
1188 {
1189 struct tuntap_softc *tp = ifp->if_softc;
1190
1191 TUNDEBUG(ifp, "tuninit\n");
1192
1193 TUN_LOCK(tp);
1194 ifp->if_drv_flags |= IFF_DRV_RUNNING;
1195 if ((tp->tun_flags & TUN_L2) == 0) {
1196 ifp->if_flags |= IFF_UP;
1197 getmicrotime(&ifp->if_lastchange);
1198 TUN_UNLOCK(tp);
1199 } else {
1200 #if defined(INET) || defined(INET6)
1201 if (tcp_lro_init(&tp->tun_lro) == 0) {
1202 TUNDEBUG(ifp, "LRO enabled\n");
1203 tp->tun_lro.ifp = ifp;
1204 tp->tun_lro_ready = true;
1205 } else {
1206 TUNDEBUG(ifp, "Could not enable LRO\n");
1207 tp->tun_lro_ready = false;
1208 }
1209 #endif
1210 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1211 TUN_UNLOCK(tp);
1212 /* attempt to start output */
1213 tunstart_l2(ifp);
1214 }
1215
1216 }
1217
1218 /*
1219 * Used only for l2 tunnel.
1220 */
1221 static void
tunifinit(void * xtp)1222 tunifinit(void *xtp)
1223 {
1224 struct tuntap_softc *tp;
1225
1226 tp = (struct tuntap_softc *)xtp;
1227 tuninit(tp->tun_ifp);
1228 }
1229
1230 /*
1231 * To be called under TUN_LOCK. Update ifp->if_hwassist according to the
1232 * current value of ifp->if_capenable.
1233 */
1234 static void
tun_caps_changed(struct ifnet * ifp)1235 tun_caps_changed(struct ifnet *ifp)
1236 {
1237 uint64_t hwassist = 0;
1238
1239 TUN_LOCK_ASSERT((struct tuntap_softc *)ifp->if_softc);
1240 if (ifp->if_capenable & IFCAP_TXCSUM)
1241 hwassist |= CSUM_TCP | CSUM_UDP;
1242 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
1243 hwassist |= CSUM_TCP_IPV6
1244 | CSUM_UDP_IPV6;
1245 if (ifp->if_capenable & IFCAP_TSO4)
1246 hwassist |= CSUM_IP_TSO;
1247 if (ifp->if_capenable & IFCAP_TSO6)
1248 hwassist |= CSUM_IP6_TSO;
1249 ifp->if_hwassist = hwassist;
1250 }
1251
1252 /*
1253 * To be called under TUN_LOCK. Update tp->tun_vhdrlen and adjust
1254 * if_capabilities and if_capenable as needed.
1255 */
1256 static void
tun_vnethdr_set(struct ifnet * ifp,int vhdrlen)1257 tun_vnethdr_set(struct ifnet *ifp, int vhdrlen)
1258 {
1259 struct tuntap_softc *tp = ifp->if_softc;
1260
1261 TUN_LOCK_ASSERT(tp);
1262
1263 if (tp->tun_vhdrlen == vhdrlen)
1264 return;
1265
1266 /*
1267 * Update if_capabilities to reflect the
1268 * functionalities offered by the virtio-net
1269 * header.
1270 */
1271 if (vhdrlen != 0)
1272 ifp->if_capabilities |=
1273 TAP_VNET_HDR_CAPS;
1274 else
1275 ifp->if_capabilities &=
1276 ~TAP_VNET_HDR_CAPS;
1277 /*
1278 * Disable any capabilities that we don't
1279 * support anymore.
1280 */
1281 ifp->if_capenable &= ifp->if_capabilities;
1282 tun_caps_changed(ifp);
1283 tp->tun_vhdrlen = vhdrlen;
1284
1285 TUNDEBUG(ifp, "vnet_hdr_len=%d, if_capabilities=%x\n",
1286 vhdrlen, ifp->if_capabilities);
1287 }
1288
1289 /*
1290 * Process an ioctl request.
1291 */
1292 static int
tunifioctl(struct ifnet * ifp,u_long cmd,caddr_t data)1293 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1294 {
1295 struct ifreq *ifr = (struct ifreq *)data;
1296 struct tuntap_softc *tp;
1297 struct ifstat *ifs;
1298 struct ifmediareq *ifmr;
1299 int dummy, error = 0;
1300 bool l2tun;
1301
1302 ifmr = NULL;
1303 sx_xlock(&tun_ioctl_sx);
1304 tp = ifp->if_softc;
1305 if (tp == NULL) {
1306 error = ENXIO;
1307 goto bad;
1308 }
1309 l2tun = (tp->tun_flags & TUN_L2) != 0;
1310 switch(cmd) {
1311 case SIOCGIFSTATUS:
1312 ifs = (struct ifstat *)data;
1313 TUN_LOCK(tp);
1314 if (tp->tun_pid)
1315 snprintf(ifs->ascii, sizeof(ifs->ascii),
1316 "\tOpened by PID %d\n", tp->tun_pid);
1317 else
1318 ifs->ascii[0] = '\0';
1319 TUN_UNLOCK(tp);
1320 break;
1321 case SIOCSIFADDR:
1322 if (l2tun)
1323 error = ether_ioctl(ifp, cmd, data);
1324 else
1325 tuninit(ifp);
1326 if (error == 0)
1327 TUNDEBUG(ifp, "address set\n");
1328 break;
1329 case SIOCSIFMTU:
1330 ifp->if_mtu = ifr->ifr_mtu;
1331 TUNDEBUG(ifp, "mtu set\n");
1332 break;
1333 case SIOCSIFFLAGS:
1334 case SIOCADDMULTI:
1335 case SIOCDELMULTI:
1336 break;
1337 case SIOCGIFMEDIA:
1338 if (!l2tun) {
1339 error = EINVAL;
1340 break;
1341 }
1342
1343 ifmr = (struct ifmediareq *)data;
1344 dummy = ifmr->ifm_count;
1345 ifmr->ifm_count = 1;
1346 ifmr->ifm_status = IFM_AVALID;
1347 ifmr->ifm_active = IFM_ETHER | IFM_FDX | IFM_1000_T;
1348 if (tp->tun_flags & TUN_OPEN)
1349 ifmr->ifm_status |= IFM_ACTIVE;
1350 ifmr->ifm_current = ifmr->ifm_active;
1351 if (dummy >= 1) {
1352 int media = IFM_ETHER;
1353 error = copyout(&media, ifmr->ifm_ulist, sizeof(int));
1354 }
1355 break;
1356 case SIOCSIFCAP:
1357 TUN_LOCK(tp);
1358 ifp->if_capenable = ifr->ifr_reqcap;
1359 tun_caps_changed(ifp);
1360 TUN_UNLOCK(tp);
1361 VLAN_CAPABILITIES(ifp);
1362 break;
1363 default:
1364 if (l2tun) {
1365 error = ether_ioctl(ifp, cmd, data);
1366 } else {
1367 error = EINVAL;
1368 }
1369 }
1370 bad:
1371 sx_xunlock(&tun_ioctl_sx);
1372 return (error);
1373 }
1374
1375 /*
1376 * tunoutput - queue packets from higher level ready to put out.
1377 */
1378 static int
tunoutput(struct ifnet * ifp,struct mbuf * m0,const struct sockaddr * dst,struct route * ro)1379 tunoutput(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
1380 struct route *ro)
1381 {
1382 struct tuntap_softc *tp = ifp->if_softc;
1383 u_short cached_tun_flags;
1384 int error;
1385 u_int32_t af;
1386
1387 TUNDEBUG (ifp, "tunoutput\n");
1388
1389 #ifdef MAC
1390 error = mac_ifnet_check_transmit(ifp, m0);
1391 if (error) {
1392 m_freem(m0);
1393 return (error);
1394 }
1395 #endif
1396
1397 /* Could be unlocked read? */
1398 TUN_LOCK(tp);
1399 cached_tun_flags = tp->tun_flags;
1400 TUN_UNLOCK(tp);
1401 if ((cached_tun_flags & TUN_READY) != TUN_READY) {
1402 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
1403 m_freem (m0);
1404 return (EHOSTDOWN);
1405 }
1406
1407 if ((ifp->if_flags & IFF_UP) != IFF_UP) {
1408 m_freem (m0);
1409 return (EHOSTDOWN);
1410 }
1411
1412 /* BPF writes need to be handled specially. */
1413 if (dst->sa_family == AF_UNSPEC || dst->sa_family == pseudo_AF_HDRCMPLT)
1414 bcopy(dst->sa_data, &af, sizeof(af));
1415 else
1416 af = RO_GET_FAMILY(ro, dst);
1417
1418 BPF_MTAP2(ifp, &af, sizeof(af), m0);
1419
1420 /* prepend sockaddr? this may abort if the mbuf allocation fails */
1421 if (cached_tun_flags & TUN_LMODE) {
1422 /* allocate space for sockaddr */
1423 M_PREPEND(m0, dst->sa_len, M_NOWAIT);
1424
1425 /* if allocation failed drop packet */
1426 if (m0 == NULL) {
1427 if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1428 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1429 return (ENOBUFS);
1430 } else {
1431 bcopy(dst, m0->m_data, dst->sa_len);
1432 }
1433 }
1434
1435 if (cached_tun_flags & TUN_IFHEAD) {
1436 /* Prepend the address family */
1437 M_PREPEND(m0, 4, M_NOWAIT);
1438
1439 /* if allocation failed drop packet */
1440 if (m0 == NULL) {
1441 if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1442 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1443 return (ENOBUFS);
1444 } else
1445 *(u_int32_t *)m0->m_data = htonl(af);
1446 } else {
1447 #ifdef INET
1448 if (af != AF_INET)
1449 #endif
1450 {
1451 m_freem(m0);
1452 return (EAFNOSUPPORT);
1453 }
1454 }
1455
1456 error = (ifp->if_transmit)(ifp, m0);
1457 if (error)
1458 return (ENOBUFS);
1459 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
1460 return (0);
1461 }
1462
1463 /*
1464 * the cdevsw interface is now pretty minimal.
1465 */
1466 static int
tunioctl(struct cdev * dev,u_long cmd,caddr_t data,int flag,struct thread * td)1467 tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag,
1468 struct thread *td)
1469 {
1470 struct ifreq ifr, *ifrp;
1471 struct tuntap_softc *tp = dev->si_drv1;
1472 struct ifnet *ifp = TUN2IFP(tp);
1473 struct tuninfo *tunp;
1474 int error, iflags, ival;
1475 bool l2tun;
1476
1477 l2tun = (tp->tun_flags & TUN_L2) != 0;
1478 if (l2tun) {
1479 /* tap specific ioctls */
1480 switch(cmd) {
1481 /* VMware/VMnet port ioctl's */
1482 #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
1483 defined(COMPAT_FREEBSD4)
1484 case _IO('V', 0):
1485 ival = IOCPARM_IVAL(data);
1486 data = (caddr_t)&ival;
1487 /* FALLTHROUGH */
1488 #endif
1489 case VMIO_SIOCSIFFLAGS: /* VMware/VMnet SIOCSIFFLAGS */
1490 iflags = *(int *)data;
1491 iflags &= TUN_VMIO_FLAG_MASK;
1492 iflags &= ~IFF_CANTCHANGE;
1493 iflags |= IFF_UP;
1494
1495 TUN_LOCK(tp);
1496 ifp->if_flags = iflags |
1497 (ifp->if_flags & IFF_CANTCHANGE);
1498 TUN_UNLOCK(tp);
1499
1500 return (0);
1501 case SIOCGIFADDR: /* get MAC address of the remote side */
1502 TUN_LOCK(tp);
1503 bcopy(&tp->tun_ether.octet, data,
1504 sizeof(tp->tun_ether.octet));
1505 TUN_UNLOCK(tp);
1506
1507 return (0);
1508 case SIOCSIFADDR: /* set MAC address of the remote side */
1509 TUN_LOCK(tp);
1510 bcopy(data, &tp->tun_ether.octet,
1511 sizeof(tp->tun_ether.octet));
1512 TUN_UNLOCK(tp);
1513
1514 return (0);
1515 case TAPSVNETHDR:
1516 ival = *(int *)data;
1517 if (ival != 0 &&
1518 ival != sizeof(struct virtio_net_hdr) &&
1519 ival != sizeof(struct virtio_net_hdr_mrg_rxbuf)) {
1520 return (EINVAL);
1521 }
1522 TUN_LOCK(tp);
1523 tun_vnethdr_set(ifp, ival);
1524 TUN_UNLOCK(tp);
1525
1526 return (0);
1527 case TAPGVNETHDR:
1528 TUN_LOCK(tp);
1529 *(int *)data = tp->tun_vhdrlen;
1530 TUN_UNLOCK(tp);
1531
1532 return (0);
1533 }
1534
1535 /* Fall through to the common ioctls if unhandled */
1536 } else {
1537 switch (cmd) {
1538 case TUNSLMODE:
1539 TUN_LOCK(tp);
1540 if (*(int *)data) {
1541 tp->tun_flags |= TUN_LMODE;
1542 tp->tun_flags &= ~TUN_IFHEAD;
1543 } else
1544 tp->tun_flags &= ~TUN_LMODE;
1545 TUN_UNLOCK(tp);
1546
1547 return (0);
1548 case TUNSIFHEAD:
1549 TUN_LOCK(tp);
1550 if (*(int *)data) {
1551 tp->tun_flags |= TUN_IFHEAD;
1552 tp->tun_flags &= ~TUN_LMODE;
1553 } else
1554 tp->tun_flags &= ~TUN_IFHEAD;
1555 TUN_UNLOCK(tp);
1556
1557 return (0);
1558 case TUNGIFHEAD:
1559 TUN_LOCK(tp);
1560 *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
1561 TUN_UNLOCK(tp);
1562
1563 return (0);
1564 case TUNSIFMODE:
1565 /* deny this if UP */
1566 if (TUN2IFP(tp)->if_flags & IFF_UP)
1567 return (EBUSY);
1568
1569 switch (*(int *)data & ~IFF_MULTICAST) {
1570 case IFF_POINTOPOINT:
1571 case IFF_BROADCAST:
1572 TUN_LOCK(tp);
1573 TUN2IFP(tp)->if_flags &=
1574 ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
1575 TUN2IFP(tp)->if_flags |= *(int *)data;
1576 TUN_UNLOCK(tp);
1577
1578 break;
1579 default:
1580 return (EINVAL);
1581 }
1582
1583 return (0);
1584 case TUNSIFPID:
1585 TUN_LOCK(tp);
1586 tp->tun_pid = curthread->td_proc->p_pid;
1587 TUN_UNLOCK(tp);
1588
1589 return (0);
1590 }
1591 /* Fall through to the common ioctls if unhandled */
1592 }
1593
1594 switch (cmd) {
1595 case TUNGIFNAME:
1596 ifrp = (struct ifreq *)data;
1597 strlcpy(ifrp->ifr_name, TUN2IFP(tp)->if_xname, IFNAMSIZ);
1598
1599 return (0);
1600 case TUNSIFINFO:
1601 tunp = (struct tuninfo *)data;
1602 if (TUN2IFP(tp)->if_type != tunp->type)
1603 return (EPROTOTYPE);
1604 TUN_LOCK(tp);
1605 if (TUN2IFP(tp)->if_mtu != tunp->mtu) {
1606 strlcpy(ifr.ifr_name, if_name(TUN2IFP(tp)), IFNAMSIZ);
1607 ifr.ifr_mtu = tunp->mtu;
1608 CURVNET_SET(TUN2IFP(tp)->if_vnet);
1609 error = ifhwioctl(SIOCSIFMTU, TUN2IFP(tp),
1610 (caddr_t)&ifr, td);
1611 CURVNET_RESTORE();
1612 if (error) {
1613 TUN_UNLOCK(tp);
1614 return (error);
1615 }
1616 }
1617 TUN2IFP(tp)->if_baudrate = tunp->baudrate;
1618 TUN_UNLOCK(tp);
1619 break;
1620 case TUNGIFINFO:
1621 tunp = (struct tuninfo *)data;
1622 TUN_LOCK(tp);
1623 tunp->mtu = TUN2IFP(tp)->if_mtu;
1624 tunp->type = TUN2IFP(tp)->if_type;
1625 tunp->baudrate = TUN2IFP(tp)->if_baudrate;
1626 TUN_UNLOCK(tp);
1627 break;
1628 case TUNSDEBUG:
1629 tundebug = *(int *)data;
1630 break;
1631 case TUNGDEBUG:
1632 *(int *)data = tundebug;
1633 break;
1634 case FIONBIO:
1635 break;
1636 case FIOASYNC:
1637 TUN_LOCK(tp);
1638 if (*(int *)data)
1639 tp->tun_flags |= TUN_ASYNC;
1640 else
1641 tp->tun_flags &= ~TUN_ASYNC;
1642 TUN_UNLOCK(tp);
1643 break;
1644 case FIONREAD:
1645 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) {
1646 struct mbuf *mb;
1647 IFQ_LOCK(&TUN2IFP(tp)->if_snd);
1648 IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb);
1649 for (*(int *)data = 0; mb != NULL; mb = mb->m_next)
1650 *(int *)data += mb->m_len;
1651 IFQ_UNLOCK(&TUN2IFP(tp)->if_snd);
1652 } else
1653 *(int *)data = 0;
1654 break;
1655 case FIOSETOWN:
1656 return (fsetown(*(int *)data, &tp->tun_sigio));
1657
1658 case FIOGETOWN:
1659 *(int *)data = fgetown(&tp->tun_sigio);
1660 return (0);
1661
1662 /* This is deprecated, FIOSETOWN should be used instead. */
1663 case TIOCSPGRP:
1664 return (fsetown(-(*(int *)data), &tp->tun_sigio));
1665
1666 /* This is deprecated, FIOGETOWN should be used instead. */
1667 case TIOCGPGRP:
1668 *(int *)data = -fgetown(&tp->tun_sigio);
1669 return (0);
1670
1671 default:
1672 return (ENOTTY);
1673 }
1674 return (0);
1675 }
1676
1677 /*
1678 * The cdevsw read interface - reads a packet at a time, or at
1679 * least as much of a packet as can be read.
1680 */
1681 static int
tunread(struct cdev * dev,struct uio * uio,int flag)1682 tunread(struct cdev *dev, struct uio *uio, int flag)
1683 {
1684 struct tuntap_softc *tp = dev->si_drv1;
1685 struct ifnet *ifp = TUN2IFP(tp);
1686 struct mbuf *m;
1687 size_t len;
1688 int error = 0;
1689
1690 TUNDEBUG (ifp, "read\n");
1691 TUN_LOCK(tp);
1692 if ((tp->tun_flags & TUN_READY) != TUN_READY) {
1693 TUN_UNLOCK(tp);
1694 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
1695 return (EHOSTDOWN);
1696 }
1697
1698 tp->tun_flags &= ~TUN_RWAIT;
1699
1700 for (;;) {
1701 IFQ_DEQUEUE(&ifp->if_snd, m);
1702 if (m != NULL)
1703 break;
1704 if (flag & O_NONBLOCK) {
1705 TUN_UNLOCK(tp);
1706 return (EWOULDBLOCK);
1707 }
1708 tp->tun_flags |= TUN_RWAIT;
1709 error = mtx_sleep(tp, &tp->tun_mtx, PCATCH | (PZERO + 1),
1710 "tunread", 0);
1711 if (error != 0) {
1712 TUN_UNLOCK(tp);
1713 return (error);
1714 }
1715 }
1716 TUN_UNLOCK(tp);
1717
1718 len = min(tp->tun_vhdrlen, uio->uio_resid);
1719 if (len > 0) {
1720 struct virtio_net_hdr_mrg_rxbuf vhdr;
1721
1722 bzero(&vhdr, sizeof(vhdr));
1723 if (m->m_pkthdr.csum_flags & TAP_ALL_OFFLOAD) {
1724 m = virtio_net_tx_offload(ifp, m, false, &vhdr.hdr);
1725 }
1726
1727 TUNDEBUG(ifp, "txvhdr: f %u, gt %u, hl %u, "
1728 "gs %u, cs %u, co %u\n", vhdr.hdr.flags,
1729 vhdr.hdr.gso_type, vhdr.hdr.hdr_len,
1730 vhdr.hdr.gso_size, vhdr.hdr.csum_start,
1731 vhdr.hdr.csum_offset);
1732 error = uiomove(&vhdr, len, uio);
1733 }
1734
1735 while (m && uio->uio_resid > 0 && error == 0) {
1736 len = min(uio->uio_resid, m->m_len);
1737 if (len != 0)
1738 error = uiomove(mtod(m, void *), len, uio);
1739 m = m_free(m);
1740 }
1741
1742 if (m) {
1743 TUNDEBUG(ifp, "Dropping mbuf\n");
1744 m_freem(m);
1745 }
1746 return (error);
1747 }
1748
1749 static int
tunwrite_l2(struct tuntap_softc * tp,struct mbuf * m,struct virtio_net_hdr_mrg_rxbuf * vhdr)1750 tunwrite_l2(struct tuntap_softc *tp, struct mbuf *m,
1751 struct virtio_net_hdr_mrg_rxbuf *vhdr)
1752 {
1753 struct epoch_tracker et;
1754 struct ether_header *eh;
1755 struct ifnet *ifp;
1756
1757 ifp = TUN2IFP(tp);
1758
1759 /*
1760 * Only pass a unicast frame to ether_input(), if it would
1761 * actually have been received by non-virtual hardware.
1762 */
1763 if (m->m_len < sizeof(struct ether_header)) {
1764 m_freem(m);
1765 return (0);
1766 }
1767
1768 eh = mtod(m, struct ether_header *);
1769
1770 if ((ifp->if_flags & IFF_PROMISC) == 0 &&
1771 !ETHER_IS_MULTICAST(eh->ether_dhost) &&
1772 bcmp(eh->ether_dhost, IF_LLADDR(ifp), ETHER_ADDR_LEN) != 0) {
1773 m_freem(m);
1774 return (0);
1775 }
1776
1777 if (vhdr != NULL) {
1778 if (virtio_net_rx_csum(m, &vhdr->hdr)) {
1779 m_freem(m);
1780 return (0);
1781 }
1782 } else {
1783 switch (ntohs(eh->ether_type)) {
1784 #ifdef INET
1785 case ETHERTYPE_IP:
1786 if (ifp->if_capenable & IFCAP_RXCSUM) {
1787 m->m_pkthdr.csum_flags |=
1788 CSUM_IP_CHECKED | CSUM_IP_VALID |
1789 CSUM_DATA_VALID | CSUM_SCTP_VALID |
1790 CSUM_PSEUDO_HDR;
1791 m->m_pkthdr.csum_data = 0xffff;
1792 }
1793 break;
1794 #endif
1795 #ifdef INET6
1796 case ETHERTYPE_IPV6:
1797 if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) {
1798 m->m_pkthdr.csum_flags |=
1799 CSUM_DATA_VALID_IPV6 | CSUM_SCTP_VALID |
1800 CSUM_PSEUDO_HDR;
1801 m->m_pkthdr.csum_data = 0xffff;
1802 }
1803 break;
1804 #endif
1805 }
1806 }
1807
1808 /* Pass packet up to parent. */
1809 CURVNET_SET(ifp->if_vnet);
1810 NET_EPOCH_ENTER(et);
1811 #if defined(INET) || defined(INET6)
1812 if (tp->tun_lro_ready && ifp->if_capenable & IFCAP_LRO &&
1813 tcp_lro_rx(&tp->tun_lro, m, 0) == 0)
1814 tcp_lro_flush_all(&tp->tun_lro);
1815 else
1816 #endif
1817 (*ifp->if_input)(ifp, m);
1818 NET_EPOCH_EXIT(et);
1819 CURVNET_RESTORE();
1820 /* ibytes are counted in parent */
1821 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1822 return (0);
1823 }
1824
1825 static int
tunwrite_l3(struct tuntap_softc * tp,struct mbuf * m)1826 tunwrite_l3(struct tuntap_softc *tp, struct mbuf *m)
1827 {
1828 struct epoch_tracker et;
1829 struct ifnet *ifp;
1830 int family, isr;
1831
1832 ifp = TUN2IFP(tp);
1833 /* Could be unlocked read? */
1834 TUN_LOCK(tp);
1835 if (tp->tun_flags & TUN_IFHEAD) {
1836 TUN_UNLOCK(tp);
1837 if (m->m_len < sizeof(family) &&
1838 (m = m_pullup(m, sizeof(family))) == NULL)
1839 return (ENOBUFS);
1840 family = ntohl(*mtod(m, u_int32_t *));
1841 m_adj(m, sizeof(family));
1842 } else {
1843 TUN_UNLOCK(tp);
1844 family = AF_INET;
1845 }
1846
1847 BPF_MTAP2(ifp, &family, sizeof(family), m);
1848
1849 switch (family) {
1850 #ifdef INET
1851 case AF_INET:
1852 isr = NETISR_IP;
1853 break;
1854 #endif
1855 #ifdef INET6
1856 case AF_INET6:
1857 isr = NETISR_IPV6;
1858 break;
1859 #endif
1860 default:
1861 m_freem(m);
1862 return (EAFNOSUPPORT);
1863 }
1864 random_harvest_queue(m, sizeof(*m), RANDOM_NET_TUN);
1865 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
1866 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1867 CURVNET_SET(ifp->if_vnet);
1868 M_SETFIB(m, ifp->if_fib);
1869 NET_EPOCH_ENTER(et);
1870 netisr_dispatch(isr, m);
1871 NET_EPOCH_EXIT(et);
1872 CURVNET_RESTORE();
1873 return (0);
1874 }
1875
1876 /*
1877 * the cdevsw write interface - an atomic write is a packet - or else!
1878 */
1879 static int
tunwrite(struct cdev * dev,struct uio * uio,int flag)1880 tunwrite(struct cdev *dev, struct uio *uio, int flag)
1881 {
1882 struct virtio_net_hdr_mrg_rxbuf vhdr;
1883 struct tuntap_softc *tp;
1884 struct ifnet *ifp;
1885 struct mbuf *m;
1886 uint32_t mru;
1887 int align, vhdrlen, error;
1888 bool l2tun;
1889
1890 tp = dev->si_drv1;
1891 ifp = TUN2IFP(tp);
1892 TUNDEBUG(ifp, "tunwrite\n");
1893 if ((ifp->if_flags & IFF_UP) != IFF_UP)
1894 /* ignore silently */
1895 return (0);
1896
1897 if (uio->uio_resid == 0)
1898 return (0);
1899
1900 l2tun = (tp->tun_flags & TUN_L2) != 0;
1901 mru = l2tun ? TAPMRU : TUNMRU;
1902 vhdrlen = tp->tun_vhdrlen;
1903 align = 0;
1904 if (l2tun) {
1905 align = ETHER_ALIGN;
1906 mru += vhdrlen;
1907 } else if ((tp->tun_flags & TUN_IFHEAD) != 0)
1908 mru += sizeof(uint32_t); /* family */
1909 if (uio->uio_resid < 0 || uio->uio_resid > mru) {
1910 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid);
1911 return (EIO);
1912 }
1913
1914 if (vhdrlen > 0) {
1915 error = uiomove(&vhdr, vhdrlen, uio);
1916 if (error != 0)
1917 return (error);
1918 TUNDEBUG(ifp, "txvhdr: f %u, gt %u, hl %u, "
1919 "gs %u, cs %u, co %u\n", vhdr.hdr.flags,
1920 vhdr.hdr.gso_type, vhdr.hdr.hdr_len,
1921 vhdr.hdr.gso_size, vhdr.hdr.csum_start,
1922 vhdr.hdr.csum_offset);
1923 }
1924
1925 if ((m = m_uiotombuf(uio, M_NOWAIT, 0, align, M_PKTHDR)) == NULL) {
1926 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
1927 return (ENOBUFS);
1928 }
1929
1930 m->m_pkthdr.rcvif = ifp;
1931 #ifdef MAC
1932 mac_ifnet_create_mbuf(ifp, m);
1933 #endif
1934
1935 if (l2tun)
1936 return (tunwrite_l2(tp, m, vhdrlen > 0 ? &vhdr : NULL));
1937
1938 return (tunwrite_l3(tp, m));
1939 }
1940
1941 /*
1942 * tunpoll - the poll interface, this is only useful on reads
1943 * really. The write detect always returns true, write never blocks
1944 * anyway, it either accepts the packet or drops it.
1945 */
1946 static int
tunpoll(struct cdev * dev,int events,struct thread * td)1947 tunpoll(struct cdev *dev, int events, struct thread *td)
1948 {
1949 struct tuntap_softc *tp = dev->si_drv1;
1950 struct ifnet *ifp = TUN2IFP(tp);
1951 int revents = 0;
1952
1953 TUNDEBUG(ifp, "tunpoll\n");
1954
1955 if (events & (POLLIN | POLLRDNORM)) {
1956 IFQ_LOCK(&ifp->if_snd);
1957 if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
1958 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len);
1959 revents |= events & (POLLIN | POLLRDNORM);
1960 } else {
1961 TUNDEBUG(ifp, "tunpoll waiting\n");
1962 selrecord(td, &tp->tun_rsel);
1963 }
1964 IFQ_UNLOCK(&ifp->if_snd);
1965 }
1966 revents |= events & (POLLOUT | POLLWRNORM);
1967
1968 return (revents);
1969 }
1970
1971 /*
1972 * tunkqfilter - support for the kevent() system call.
1973 */
1974 static int
tunkqfilter(struct cdev * dev,struct knote * kn)1975 tunkqfilter(struct cdev *dev, struct knote *kn)
1976 {
1977 struct tuntap_softc *tp = dev->si_drv1;
1978 struct ifnet *ifp = TUN2IFP(tp);
1979
1980 switch(kn->kn_filter) {
1981 case EVFILT_READ:
1982 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n",
1983 ifp->if_xname, dev2unit(dev));
1984 kn->kn_fop = &tun_read_filterops;
1985 break;
1986
1987 case EVFILT_WRITE:
1988 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n",
1989 ifp->if_xname, dev2unit(dev));
1990 kn->kn_fop = &tun_write_filterops;
1991 break;
1992
1993 default:
1994 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n",
1995 ifp->if_xname, dev2unit(dev));
1996 return(EINVAL);
1997 }
1998
1999 kn->kn_hook = tp;
2000 knlist_add(&tp->tun_rsel.si_note, kn, 0);
2001
2002 return (0);
2003 }
2004
2005 /*
2006 * Return true of there is data in the interface queue.
2007 */
2008 static int
tunkqread(struct knote * kn,long hint)2009 tunkqread(struct knote *kn, long hint)
2010 {
2011 int ret;
2012 struct tuntap_softc *tp = kn->kn_hook;
2013 struct cdev *dev = tp->tun_dev;
2014 struct ifnet *ifp = TUN2IFP(tp);
2015
2016 if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) {
2017 TUNDEBUG(ifp,
2018 "%s have data in the queue. Len = %d, minor = %#x\n",
2019 ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev));
2020 ret = 1;
2021 } else {
2022 TUNDEBUG(ifp,
2023 "%s waiting for data, minor = %#x\n", ifp->if_xname,
2024 dev2unit(dev));
2025 ret = 0;
2026 }
2027
2028 return (ret);
2029 }
2030
2031 /*
2032 * Always can write, always return MTU in kn->data.
2033 */
2034 static int
tunkqwrite(struct knote * kn,long hint)2035 tunkqwrite(struct knote *kn, long hint)
2036 {
2037 struct tuntap_softc *tp = kn->kn_hook;
2038 struct ifnet *ifp = TUN2IFP(tp);
2039
2040 kn->kn_data = ifp->if_mtu;
2041
2042 return (1);
2043 }
2044
2045 static void
tunkqdetach(struct knote * kn)2046 tunkqdetach(struct knote *kn)
2047 {
2048 struct tuntap_softc *tp = kn->kn_hook;
2049
2050 knlist_remove(&tp->tun_rsel.si_note, kn, 0);
2051 }
2052