sys/net/if_tuntap.c

   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 <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 };
 148 #define TUN2IFP(sc)     ((sc)->tun_ifp)
 149
 150 #define TUNDEBUG        if (tundebug) if_printf
 151
 152 #define TUN_LOCK(tp)            mtx_lock(&(tp)->tun_mtx)
 153 #define TUN_UNLOCK(tp)          mtx_unlock(&(tp)->tun_mtx)
 154 #define TUN_LOCK_ASSERT(tp)     mtx_assert(&(tp)->tun_mtx, MA_OWNED);
 155
 156 #define TUN_VMIO_FLAG_MASK      0x0fff
 157
 158 /*
 159  * Interface capabilities of a tap device that supports the virtio-net
 160  * header.
 161  */
 162 #define TAP_VNET_HDR_CAPS       (IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6       \
 163                                 | IFCAP_VLAN_HWCSUM                     \
 164                                 | IFCAP_TSO | IFCAP_LRO                 \
 165                                 | IFCAP_VLAN_HWTSO)
 166
 167 #define TAP_ALL_OFFLOAD         (CSUM_TSO | CSUM_TCP | CSUM_UDP |\
 168                                     CSUM_TCP_IPV6 | CSUM_UDP_IPV6)
 169
 170 /*
 171  * All mutable global variables in if_tun are locked using tunmtx, with
 172  * the exception of tundebug, which is used unlocked, and the drivers' *clones,
 173  * which are static after setup.
 174  */
 175 static struct mtx tunmtx;
 176 static eventhandler_tag arrival_tag;
 177 static eventhandler_tag clone_tag;
 178 static const char tunname[] = "tun";
 179 static const char tapname[] = "tap";
 180 static const char vmnetname[] = "vmnet";
 181 static MALLOC_DEFINE(M_TUN, tunname, "Tunnel Interface");
 182 static int tundebug = 0;
 183 static int tundclone = 1;
 184 static int tap_allow_uopen = 0; /* allow user devfs cloning */
 185 static int tapuponopen = 0;     /* IFF_UP on open() */
 186 static int tapdclone = 1;       /* enable devfs cloning */
 187
 188 static TAILQ_HEAD(,tuntap_softc)        tunhead = TAILQ_HEAD_INITIALIZER(tunhead);
 189 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");
 190
 191 static struct sx tun_ioctl_sx;
 192 SX_SYSINIT(tun_ioctl_sx, &tun_ioctl_sx, "tun_ioctl");
 193
 194 SYSCTL_DECL(_net_link);
 195 /* tun */
 196 static SYSCTL_NODE(_net_link, OID_AUTO, tun, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
 197     "IP tunnel software network interface");
 198 SYSCTL_INT(_net_link_tun, OID_AUTO, devfs_cloning, CTLFLAG_RWTUN, &tundclone, 0,
 199     "Enable legacy devfs interface creation");
 200
 201 /* tap */
 202 static SYSCTL_NODE(_net_link, OID_AUTO, tap, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
 203     "Ethernet tunnel software network interface");
 204 SYSCTL_INT(_net_link_tap, OID_AUTO, user_open, CTLFLAG_RW, &tap_allow_uopen, 0,
 205     "Enable legacy devfs interface creation for all users");
 206 SYSCTL_INT(_net_link_tap, OID_AUTO, up_on_open, CTLFLAG_RW, &tapuponopen, 0,
 207     "Bring interface up when /dev/tap is opened");
 208 SYSCTL_INT(_net_link_tap, OID_AUTO, devfs_cloning, CTLFLAG_RWTUN, &tapdclone, 0,
 209     "Enable legacy devfs interface creation");
 210 SYSCTL_INT(_net_link_tap, OID_AUTO, debug, CTLFLAG_RW, &tundebug, 0, "");
 211
 212 static int      tun_create_device(struct tuntap_driver *drv, int unit,
 213     struct ucred *cr, struct cdev **dev, const char *name);
 214 static int      tun_busy_locked(struct tuntap_softc *tp);
 215 static void     tun_unbusy_locked(struct tuntap_softc *tp);
 216 static int      tun_busy(struct tuntap_softc *tp);
 217 static void     tun_unbusy(struct tuntap_softc *tp);
 218
 219 static int      tuntap_name2info(const char *name, int *unit, int *flags);
 220 static void     tunclone(void *arg, struct ucred *cred, char *name,
 221                     int namelen, struct cdev **dev);
 222 static void     tuncreate(struct cdev *dev);
 223 static void     tundtor(void *data);
 224 static void     tunrename(void *arg, struct ifnet *ifp);
 225 static int      tunifioctl(struct ifnet *, u_long, caddr_t);
 226 static void     tuninit(struct ifnet *);
 227 static void     tunifinit(void *xtp);
 228 static int      tuntapmodevent(module_t, int, void *);
 229 static int      tunoutput(struct ifnet *, struct mbuf *,
 230                     const struct sockaddr *, struct route *ro);
 231 static void     tunstart(struct ifnet *);
 232 static void     tunstart_l2(struct ifnet *);
 233
 234 static int      tun_clone_match(struct if_clone *ifc, const char *name);
 235 static int      tap_clone_match(struct if_clone *ifc, const char *name);
 236 static int      vmnet_clone_match(struct if_clone *ifc, const char *name);
 237 static int      tun_clone_create(struct if_clone *, char *, size_t,
 238                     struct ifc_data *, struct ifnet **);
 239 static int      tun_clone_destroy(struct if_clone *, struct ifnet *, uint32_t);
 240 static void     tun_vnethdr_set(struct ifnet *ifp, int vhdrlen);
 241
 242 static d_open_t         tunopen;
 243 static d_read_t         tunread;
 244 static d_write_t        tunwrite;
 245 static d_ioctl_t        tunioctl;
 246 static d_poll_t         tunpoll;
 247 static d_kqfilter_t     tunkqfilter;
 248
 249 static int              tunkqread(struct knote *, long);
 250 static int              tunkqwrite(struct knote *, long);
 251 static void             tunkqdetach(struct knote *);
 252
 253 static struct filterops tun_read_filterops = {
 254         .f_isfd =       1,
 255         .f_attach =     NULL,
 256         .f_detach =     tunkqdetach,
 257         .f_event =      tunkqread,
 258 };
 259
 260 static struct filterops tun_write_filterops = {
 261         .f_isfd =       1,
 262         .f_attach =     NULL,
 263         .f_detach =     tunkqdetach,
 264         .f_event =      tunkqwrite,
 265 };
 266
 267 static struct tuntap_driver {
 268         struct cdevsw            cdevsw;
 269         int                      ident_flags;
 270         struct unrhdr           *unrhdr;
 271         struct clonedevs        *clones;
 272         ifc_match_f             *clone_match_fn;
 273         ifc_create_f            *clone_create_fn;
 274         ifc_destroy_f           *clone_destroy_fn;
 275 } tuntap_drivers[] = {
 276         {
 277                 .ident_flags =  0,
 278                 .cdevsw =       {
 279                     .d_version =        D_VERSION,
 280                     .d_flags =          D_NEEDMINOR,
 281                     .d_open =           tunopen,
 282                     .d_read =           tunread,
 283                     .d_write =          tunwrite,
 284                     .d_ioctl =          tunioctl,
 285                     .d_poll =           tunpoll,
 286                     .d_kqfilter =       tunkqfilter,
 287                     .d_name =           tunname,
 288                 },
 289                 .clone_match_fn =       tun_clone_match,
 290                 .clone_create_fn =      tun_clone_create,
 291                 .clone_destroy_fn =     tun_clone_destroy,
 292         },
 293         {
 294                 .ident_flags =  TUN_L2,
 295                 .cdevsw =       {
 296                     .d_version =        D_VERSION,
 297                     .d_flags =          D_NEEDMINOR,
 298                     .d_open =           tunopen,
 299                     .d_read =           tunread,
 300                     .d_write =          tunwrite,
 301                     .d_ioctl =          tunioctl,
 302                     .d_poll =           tunpoll,
 303                     .d_kqfilter =       tunkqfilter,
 304                     .d_name =           tapname,
 305                 },
 306                 .clone_match_fn =       tap_clone_match,
 307                 .clone_create_fn =      tun_clone_create,
 308                 .clone_destroy_fn =     tun_clone_destroy,
 309         },
 310         {
 311                 .ident_flags =  TUN_L2 | TUN_VMNET,
 312                 .cdevsw =       {
 313                     .d_version =        D_VERSION,
 314                     .d_flags =          D_NEEDMINOR,
 315                     .d_open =           tunopen,
 316                     .d_read =           tunread,
 317                     .d_write =          tunwrite,
 318                     .d_ioctl =          tunioctl,
 319                     .d_poll =           tunpoll,
 320                     .d_kqfilter =       tunkqfilter,
 321                     .d_name =           vmnetname,
 322                 },
 323                 .clone_match_fn =       vmnet_clone_match,
 324                 .clone_create_fn =      tun_clone_create,
 325                 .clone_destroy_fn =     tun_clone_destroy,
 326         },
 327 };
 328
 329 struct tuntap_driver_cloner {
 330         SLIST_ENTRY(tuntap_driver_cloner)        link;
 331         struct tuntap_driver                    *drv;
 332         struct if_clone                         *cloner;
 333 };
 334
 335 VNET_DEFINE_STATIC(SLIST_HEAD(, tuntap_driver_cloner), tuntap_driver_cloners) =
 336     SLIST_HEAD_INITIALIZER(tuntap_driver_cloners);
 337
 338 #define V_tuntap_driver_cloners VNET(tuntap_driver_cloners)
 339
 340 /*
 341  * Mechanism for marking a tunnel device as busy so that we can safely do some
 342  * orthogonal operations (such as operations on devices) without racing against
 343  * tun_destroy.  tun_destroy will wait on the condvar if we're at all busy or
 344  * open, to be woken up when the condition is alleviated.
 345  */
 346 static int
 347 tun_busy_locked(struct tuntap_softc *tp)
 348 {
 349
 350         TUN_LOCK_ASSERT(tp);
 351         if ((tp->tun_flags & TUN_DYING) != 0) {
 352                 /*
 353                  * Perhaps unintuitive, but the device is busy going away.
 354                  * Other interpretations of EBUSY from tun_busy make little
 355                  * sense, since making a busy device even more busy doesn't
 356                  * sound like a problem.
 357                  */
 358                 return (EBUSY);
 359         }
 360
 361         ++tp->tun_busy;
 362         return (0);
 363 }
 364
 365 static void
 366 tun_unbusy_locked(struct tuntap_softc *tp)
 367 {
 368
 369         TUN_LOCK_ASSERT(tp);
 370         KASSERT(tp->tun_busy != 0, ("tun_unbusy: called for non-busy tunnel"));
 371
 372         --tp->tun_busy;
 373         /* Wake up anything that may be waiting on our busy tunnel. */
 374         if (tp->tun_busy == 0)
 375                 cv_broadcast(&tp->tun_cv);
 376 }
 377
 378 static int
 379 tun_busy(struct tuntap_softc *tp)
 380 {
 381         int ret;
 382
 383         TUN_LOCK(tp);
 384         ret = tun_busy_locked(tp);
 385         TUN_UNLOCK(tp);
 386         return (ret);
 387 }
 388
 389 static void
 390 tun_unbusy(struct tuntap_softc *tp)
 391 {
 392
 393         TUN_LOCK(tp);
 394         tun_unbusy_locked(tp);
 395         TUN_UNLOCK(tp);
 396 }
 397
 398 /*
 399  * Sets unit and/or flags given the device name.  Must be called with correct
 400  * vnet context.
 401  */
 402 static int
 403 tuntap_name2info(const char *name, int *outunit, int *outflags)
 404 {
 405         struct tuntap_driver *drv;
 406         struct tuntap_driver_cloner *drvc;
 407         char *dname;
 408         int flags, unit;
 409         bool found;
 410
 411         if (name == NULL)
 412                 return (EINVAL);
 413
 414         /*
 415          * Needed for dev_stdclone, but dev_stdclone will not modify, it just
 416          * wants to be able to pass back a char * through the second param. We
 417          * will always set that as NULL here, so we'll fake it.
 418          */
 419         dname = __DECONST(char *, name);
 420         found = false;
 421
 422         KASSERT(!SLIST_EMPTY(&V_tuntap_driver_cloners),
 423             ("tuntap_driver_cloners failed to initialize"));
 424         SLIST_FOREACH(drvc, &V_tuntap_driver_cloners, link) {
 425                 KASSERT(drvc->drv != NULL,
 426                     ("tuntap_driver_cloners entry not properly initialized"));
 427                 drv = drvc->drv;
 428
 429                 if (strcmp(name, drv->cdevsw.d_name) == 0) {
 430                         found = true;
 431                         unit = -1;
 432                         flags = drv->ident_flags;
 433                         break;
 434                 }
 435
 436                 if (dev_stdclone(dname, NULL, drv->cdevsw.d_name, &unit) == 1) {
 437                         found = true;
 438                         flags = drv->ident_flags;
 439                         break;
 440                 }
 441         }
 442
 443         if (!found)
 444                 return (ENXIO);
 445
 446         if (outunit != NULL)
 447                 *outunit = unit;
 448         if (outflags != NULL)
 449                 *outflags = flags;
 450         return (0);
 451 }
 452
 453 /*
 454  * Get driver information from a set of flags specified.  Masks the identifying
 455  * part of the flags and compares it against all of the available
 456  * tuntap_drivers. Must be called with correct vnet context.
 457  */
 458 static struct tuntap_driver *
 459 tuntap_driver_from_flags(int tun_flags)
 460 {
 461         struct tuntap_driver *drv;
 462         struct tuntap_driver_cloner *drvc;
 463
 464         KASSERT(!SLIST_EMPTY(&V_tuntap_driver_cloners),
 465             ("tuntap_driver_cloners failed to initialize"));
 466         SLIST_FOREACH(drvc, &V_tuntap_driver_cloners, link) {
 467                 KASSERT(drvc->drv != NULL,
 468                     ("tuntap_driver_cloners entry not properly initialized"));
 469                 drv = drvc->drv;
 470                 if ((tun_flags & TUN_DRIVER_IDENT_MASK) == drv->ident_flags)
 471                         return (drv);
 472         }
 473
 474         return (NULL);
 475 }
 476
 477 static int
 478 tun_clone_match(struct if_clone *ifc, const char *name)
 479 {
 480         int tunflags;
 481
 482         if (tuntap_name2info(name, NULL, &tunflags) == 0) {
 483                 if ((tunflags & TUN_L2) == 0)
 484                         return (1);
 485         }
 486
 487         return (0);
 488 }
 489
 490 static int
 491 tap_clone_match(struct if_clone *ifc, const char *name)
 492 {
 493         int tunflags;
 494
 495         if (tuntap_name2info(name, NULL, &tunflags) == 0) {
 496                 if ((tunflags & (TUN_L2 | TUN_VMNET)) == TUN_L2)
 497                         return (1);
 498         }
 499
 500         return (0);
 501 }
 502
 503 static int
 504 vmnet_clone_match(struct if_clone *ifc, const char *name)
 505 {
 506         int tunflags;
 507
 508         if (tuntap_name2info(name, NULL, &tunflags) == 0) {
 509                 if ((tunflags & TUN_VMNET) != 0)
 510                         return (1);
 511         }
 512
 513         return (0);
 514 }
 515
 516 static int
 517 tun_clone_create(struct if_clone *ifc, char *name, size_t len,
 518     struct ifc_data *ifd, struct ifnet **ifpp)
 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         /* No preexisting struct cdev *, create one */
 548         if (i != 0)
 549                 i = tun_create_device(drv, unit, NULL, &dev, name);
 550         if (i == 0) {
 551                 tuncreate(dev);
 552                 struct tuntap_softc *tp = dev->si_drv1;
 553                 *ifpp = tp->tun_ifp;
 554         }
 555
 556         return (i);
 557 }
 558
 559 static void
 560 tunclone(void *arg, struct ucred *cred, char *name, int namelen,
 561     struct cdev **dev)
 562 {
 563         char devname[SPECNAMELEN + 1];
 564         struct tuntap_driver *drv;
 565         int append_unit, i, u, tunflags;
 566         bool mayclone;
 567
 568         if (*dev != NULL)
 569                 return;
 570
 571         tunflags = 0;
 572         CURVNET_SET(CRED_TO_VNET(cred));
 573         if (tuntap_name2info(name, &u, &tunflags) != 0)
 574                 goto out;       /* Not recognized */
 575
 576         if (u != -1 && u > IF_MAXUNIT)
 577                 goto out;       /* Unit number too high */
 578
 579         mayclone = priv_check_cred(cred, PRIV_NET_IFCREATE) == 0;
 580         if ((tunflags & TUN_L2) != 0) {
 581                 /* tap/vmnet allow user open with a sysctl */
 582                 mayclone = (mayclone || tap_allow_uopen) && tapdclone;
 583         } else {
 584                 mayclone = mayclone && tundclone;
 585         }
 586
 587         /*
 588          * If tun cloning is enabled, only the superuser can create an
 589          * interface.
 590          */
 591         if (!mayclone)
 592                 goto out;
 593
 594         if (u == -1)
 595                 append_unit = 1;
 596         else
 597                 append_unit = 0;
 598
 599         drv = tuntap_driver_from_flags(tunflags);
 600         if (drv == NULL)
 601                 goto out;
 602
 603         /* find any existing device, or allocate new unit number */
 604         i = clone_create(&drv->clones, &drv->cdevsw, &u, dev, 0);
 605         if (i) {
 606                 if (append_unit) {
 607                         namelen = snprintf(devname, sizeof(devname), "%s%d",
 608                             name, u);
 609                         name = devname;
 610                 }
 611
 612                 i = tun_create_device(drv, u, cred, dev, name);
 613         }
 614         if (i == 0)
 615                 if_clone_create(name, namelen, NULL);
 616 out:
 617         CURVNET_RESTORE();
 618 }
 619
 620 static void
 621 tun_destroy(struct tuntap_softc *tp)
 622 {
 623
 624         TUN_LOCK(tp);
 625         tp->tun_flags |= TUN_DYING;
 626         if (tp->tun_busy != 0)
 627                 cv_wait_unlock(&tp->tun_cv, &tp->tun_mtx);
 628         else
 629                 TUN_UNLOCK(tp);
 630
 631         CURVNET_SET(TUN2IFP(tp)->if_vnet);
 632
 633         /* destroy_dev will take care of any alias. */
 634         destroy_dev(tp->tun_dev);
 635         seldrain(&tp->tun_rsel);
 636         knlist_clear(&tp->tun_rsel.si_note, 0);
 637         knlist_destroy(&tp->tun_rsel.si_note);
 638         if ((tp->tun_flags & TUN_L2) != 0) {
 639                 ether_ifdetach(TUN2IFP(tp));
 640         } else {
 641                 bpfdetach(TUN2IFP(tp));
 642                 if_detach(TUN2IFP(tp));
 643         }
 644         sx_xlock(&tun_ioctl_sx);
 645         TUN2IFP(tp)->if_softc = NULL;
 646         sx_xunlock(&tun_ioctl_sx);
 647         free_unr(tp->tun_drv->unrhdr, TUN2IFP(tp)->if_dunit);
 648         if_free(TUN2IFP(tp));
 649         mtx_destroy(&tp->tun_mtx);
 650         cv_destroy(&tp->tun_cv);
 651         free(tp, M_TUN);
 652         CURVNET_RESTORE();
 653 }
 654
 655 static int
 656 tun_clone_destroy(struct if_clone *ifc __unused, struct ifnet *ifp, uint32_t flags)
 657 {
 658         struct tuntap_softc *tp = ifp->if_softc;
 659
 660         mtx_lock(&tunmtx);
 661         TAILQ_REMOVE(&tunhead, tp, tun_list);
 662         mtx_unlock(&tunmtx);
 663         tun_destroy(tp);
 664
 665         return (0);
 666 }
 667
 668 static void
 669 vnet_tun_init(const void *unused __unused)
 670 {
 671         struct tuntap_driver *drv;
 672         struct tuntap_driver_cloner *drvc;
 673         int i;
 674
 675         for (i = 0; i < nitems(tuntap_drivers); ++i) {
 676                 drv = &tuntap_drivers[i];
 677                 drvc = malloc(sizeof(*drvc), M_TUN, M_WAITOK | M_ZERO);
 678
 679                 drvc->drv = drv;
 680                 struct if_clone_addreq req = {
 681                         .match_f = drv->clone_match_fn,
 682                         .create_f = drv->clone_create_fn,
 683                         .destroy_f = drv->clone_destroy_fn,
 684                 };
 685                 drvc->cloner = ifc_attach_cloner(drv->cdevsw.d_name, &req);
 686                 SLIST_INSERT_HEAD(&V_tuntap_driver_cloners, drvc, link);
 687         };
 688 }
 689 VNET_SYSINIT(vnet_tun_init, SI_SUB_PROTO_IF, SI_ORDER_ANY,
 690                 vnet_tun_init, NULL);
 691
 692 static void
 693 vnet_tun_uninit(const void *unused __unused)
 694 {
 695         struct tuntap_driver_cloner *drvc;
 696
 697         while (!SLIST_EMPTY(&V_tuntap_driver_cloners)) {
 698                 drvc = SLIST_FIRST(&V_tuntap_driver_cloners);
 699                 SLIST_REMOVE_HEAD(&V_tuntap_driver_cloners, link);
 700
 701                 if_clone_detach(drvc->cloner);
 702                 free(drvc, M_TUN);
 703         }
 704 }
 705 VNET_SYSUNINIT(vnet_tun_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY,
 706     vnet_tun_uninit, NULL);
 707
 708 static void
 709 tun_uninit(const void *unused __unused)
 710 {
 711         struct tuntap_driver *drv;
 712         struct tuntap_softc *tp;
 713         int i;
 714
 715         EVENTHANDLER_DEREGISTER(ifnet_arrival_event, arrival_tag);
 716         EVENTHANDLER_DEREGISTER(dev_clone, clone_tag);
 717
 718         mtx_lock(&tunmtx);
 719         while ((tp = TAILQ_FIRST(&tunhead)) != NULL) {
 720                 TAILQ_REMOVE(&tunhead, tp, tun_list);
 721                 mtx_unlock(&tunmtx);
 722                 tun_destroy(tp);
 723                 mtx_lock(&tunmtx);
 724         }
 725         mtx_unlock(&tunmtx);
 726         for (i = 0; i < nitems(tuntap_drivers); ++i) {
 727                 drv = &tuntap_drivers[i];
 728                 delete_unrhdr(drv->unrhdr);
 729                 clone_cleanup(&drv->clones);
 730         }
 731         mtx_destroy(&tunmtx);
 732 }
 733 SYSUNINIT(tun_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY, tun_uninit, NULL);
 734
 735 static struct tuntap_driver *
 736 tuntap_driver_from_ifnet(const struct ifnet *ifp)
 737 {
 738         struct tuntap_driver *drv;
 739         int i;
 740
 741         if (ifp == NULL)
 742                 return (NULL);
 743
 744         for (i = 0; i < nitems(tuntap_drivers); ++i) {
 745                 drv = &tuntap_drivers[i];
 746                 if (strcmp(ifp->if_dname, drv->cdevsw.d_name) == 0)
 747                         return (drv);
 748         }
 749
 750         return (NULL);
 751 }
 752
 753 static int
 754 tuntapmodevent(module_t mod, int type, void *data)
 755 {
 756         struct tuntap_driver *drv;
 757         int i;
 758
 759         switch (type) {
 760         case MOD_LOAD:
 761                 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF);
 762                 for (i = 0; i < nitems(tuntap_drivers); ++i) {
 763                         drv = &tuntap_drivers[i];
 764                         clone_setup(&drv->clones);
 765                         drv->unrhdr = new_unrhdr(0, IF_MAXUNIT, &tunmtx);
 766                 }
 767                 arrival_tag = EVENTHANDLER_REGISTER(ifnet_arrival_event,
 768                    tunrename, 0, 1000);
 769                 if (arrival_tag == NULL)
 770                         return (ENOMEM);
 771                 clone_tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000);
 772                 if (clone_tag == NULL)
 773                         return (ENOMEM);
 774                 break;
 775         case MOD_UNLOAD:
 776                 /* See tun_uninit, so it's done after the vnet_sysuninit() */
 777                 break;
 778         default:
 779                 return EOPNOTSUPP;
 780         }
 781         return 0;
 782 }
 783
 784 static moduledata_t tuntap_mod = {
 785         "if_tuntap",
 786         tuntapmodevent,
 787         0
 788 };
 789
 790 /* We'll only ever have these two, so no need for a macro. */
 791 static moduledata_t tun_mod = { "if_tun", NULL, 0 };
 792 static moduledata_t tap_mod = { "if_tap", NULL, 0 };
 793
 794 DECLARE_MODULE(if_tuntap, tuntap_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 795 MODULE_VERSION(if_tuntap, 1);
 796 DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 797 MODULE_VERSION(if_tun, 1);
 798 DECLARE_MODULE(if_tap, tap_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 799 MODULE_VERSION(if_tap, 1);
 800
 801 static int
 802 tun_create_device(struct tuntap_driver *drv, int unit, struct ucred *cr,
 803     struct cdev **dev, const char *name)
 804 {
 805         struct make_dev_args args;
 806         struct tuntap_softc *tp;
 807         int error;
 808
 809         tp = malloc(sizeof(*tp), M_TUN, M_WAITOK | M_ZERO);
 810         mtx_init(&tp->tun_mtx, "tun_mtx", NULL, MTX_DEF);
 811         cv_init(&tp->tun_cv, "tun_condvar");
 812         tp->tun_flags = drv->ident_flags;
 813         tp->tun_drv = drv;
 814
 815         make_dev_args_init(&args);
 816         if (cr != NULL)
 817                 args.mda_flags = MAKEDEV_REF;
 818         args.mda_devsw = &drv->cdevsw;
 819         args.mda_cr = cr;
 820         args.mda_uid = UID_UUCP;
 821         args.mda_gid = GID_DIALER;
 822         args.mda_mode = 0600;
 823         args.mda_unit = unit;
 824         args.mda_si_drv1 = tp;
 825         error = make_dev_s(&args, dev, "%s", name);
 826         if (error != 0) {
 827                 free(tp, M_TUN);
 828                 return (error);
 829         }
 830
 831         KASSERT((*dev)->si_drv1 != NULL,
 832             ("Failed to set si_drv1 at %s creation", name));
 833         tp->tun_dev = *dev;
 834         knlist_init_mtx(&tp->tun_rsel.si_note, &tp->tun_mtx);
 835         mtx_lock(&tunmtx);
 836         TAILQ_INSERT_TAIL(&tunhead, tp, tun_list);
 837         mtx_unlock(&tunmtx);
 838         return (0);
 839 }
 840
 841 static void
 842 tunstart(struct ifnet *ifp)
 843 {
 844         struct tuntap_softc *tp = ifp->if_softc;
 845         struct mbuf *m;
 846
 847         TUNDEBUG(ifp, "starting\n");
 848         if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
 849                 IFQ_LOCK(&ifp->if_snd);
 850                 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
 851                 if (m == NULL) {
 852                         IFQ_UNLOCK(&ifp->if_snd);
 853                         return;
 854                 }
 855                 IFQ_UNLOCK(&ifp->if_snd);
 856         }
 857
 858         TUN_LOCK(tp);
 859         if (tp->tun_flags & TUN_RWAIT) {
 860                 tp->tun_flags &= ~TUN_RWAIT;
 861                 wakeup(tp);
 862         }
 863         selwakeuppri(&tp->tun_rsel, PZERO + 1);
 864         KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
 865         if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) {
 866                 TUN_UNLOCK(tp);
 867                 pgsigio(&tp->tun_sigio, SIGIO, 0);
 868         } else
 869                 TUN_UNLOCK(tp);
 870 }
 871
 872 /*
 873  * tunstart_l2
 874  *
 875  * queue packets from higher level ready to put out
 876  */
 877 static void
 878 tunstart_l2(struct ifnet *ifp)
 879 {
 880         struct tuntap_softc     *tp = ifp->if_softc;
 881
 882         TUNDEBUG(ifp, "starting\n");
 883
 884         /*
 885          * do not junk pending output if we are in VMnet mode.
 886          * XXX: can this do any harm because of queue overflow?
 887          */
 888
 889         TUN_LOCK(tp);
 890         if (((tp->tun_flags & TUN_VMNET) == 0) &&
 891             ((tp->tun_flags & TUN_READY) != TUN_READY)) {
 892                 struct mbuf *m;
 893
 894                 /* Unlocked read. */
 895                 TUNDEBUG(ifp, "not ready, tun_flags = 0x%x\n", tp->tun_flags);
 896
 897                 for (;;) {
 898                         IF_DEQUEUE(&ifp->if_snd, m);
 899                         if (m != NULL) {
 900                                 m_freem(m);
 901                                 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
 902                         } else
 903                                 break;
 904                 }
 905                 TUN_UNLOCK(tp);
 906
 907                 return;
 908         }
 909
 910         ifp->if_drv_flags |= IFF_DRV_OACTIVE;
 911
 912         if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
 913                 if (tp->tun_flags & TUN_RWAIT) {
 914                         tp->tun_flags &= ~TUN_RWAIT;
 915                         wakeup(tp);
 916                 }
 917
 918                 if ((tp->tun_flags & TUN_ASYNC) && (tp->tun_sigio != NULL)) {
 919                         TUN_UNLOCK(tp);
 920                         pgsigio(&tp->tun_sigio, SIGIO, 0);
 921                         TUN_LOCK(tp);
 922                 }
 923
 924                 selwakeuppri(&tp->tun_rsel, PZERO+1);
 925                 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
 926                 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); /* obytes are counted in ether_output */
 927         }
 928
 929         ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
 930         TUN_UNLOCK(tp);
 931 } /* tunstart_l2 */
 932
 933 /* XXX: should return an error code so it can fail. */
 934 static void
 935 tuncreate(struct cdev *dev)
 936 {
 937         struct tuntap_driver *drv;
 938         struct tuntap_softc *tp;
 939         struct ifnet *ifp;
 940         struct ether_addr eaddr;
 941         int iflags;
 942         u_char type;
 943
 944         tp = dev->si_drv1;
 945         KASSERT(tp != NULL,
 946             ("si_drv1 should have been initialized at creation"));
 947
 948         drv = tp->tun_drv;
 949         iflags = IFF_MULTICAST;
 950         if ((tp->tun_flags & TUN_L2) != 0) {
 951                 type = IFT_ETHER;
 952                 iflags |= IFF_BROADCAST | IFF_SIMPLEX;
 953         } else {
 954                 type = IFT_PPP;
 955                 iflags |= IFF_POINTOPOINT;
 956         }
 957         ifp = tp->tun_ifp = if_alloc(type);
 958         if (ifp == NULL)
 959                 panic("%s%d: failed to if_alloc() interface.\n",
 960                     drv->cdevsw.d_name, dev2unit(dev));
 961         ifp->if_softc = tp;
 962         if_initname(ifp, drv->cdevsw.d_name, dev2unit(dev));
 963         ifp->if_ioctl = tunifioctl;
 964         ifp->if_flags = iflags;
 965         IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
 966         ifp->if_capabilities |= IFCAP_LINKSTATE;
 967         ifp->if_capenable |= IFCAP_LINKSTATE;
 968
 969         if ((tp->tun_flags & TUN_L2) != 0) {
 970                 ifp->if_init = tunifinit;
 971                 ifp->if_start = tunstart_l2;
 972
 973                 ether_gen_addr(ifp, &eaddr);
 974                 ether_ifattach(ifp, eaddr.octet);
 975         } else {
 976                 ifp->if_mtu = TUNMTU;
 977                 ifp->if_start = tunstart;
 978                 ifp->if_output = tunoutput;
 979
 980                 ifp->if_snd.ifq_drv_maxlen = 0;
 981                 IFQ_SET_READY(&ifp->if_snd);
 982
 983                 if_attach(ifp);
 984                 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
 985         }
 986
 987         TUN_LOCK(tp);
 988         tp->tun_flags |= TUN_INITED;
 989         TUN_UNLOCK(tp);
 990
 991         TUNDEBUG(ifp, "interface %s is created, minor = %#x\n",
 992             ifp->if_xname, dev2unit(dev));
 993 }
 994
 995 static void
 996 tunrename(void *arg __unused, struct ifnet *ifp)
 997 {
 998         struct tuntap_softc *tp;
 999         int error;
1000
1001         if ((ifp->if_flags & IFF_RENAMING) == 0)
1002                 return;
1003
1004         if (tuntap_driver_from_ifnet(ifp) == NULL)
1005                 return;
1006
1007         /*
1008          * We need to grab the ioctl sx long enough to make sure the softc is
1009          * still there.  If it is, we can safely try to busy the tun device.
1010          * The busy may fail if the device is currently dying, in which case
1011          * we do nothing.  If it doesn't fail, the busy count stops the device
1012          * from dying until we've created the alias (that will then be
1013          * subsequently destroyed).
1014          */
1015         sx_xlock(&tun_ioctl_sx);
1016         tp = ifp->if_softc;
1017         if (tp == NULL) {
1018                 sx_xunlock(&tun_ioctl_sx);
1019                 return;
1020         }
1021         error = tun_busy(tp);
1022         sx_xunlock(&tun_ioctl_sx);
1023         if (error != 0)
1024                 return;
1025         if (tp->tun_alias != NULL) {
1026                 destroy_dev(tp->tun_alias);
1027                 tp->tun_alias = NULL;
1028         }
1029
1030         if (strcmp(ifp->if_xname, tp->tun_dev->si_name) == 0)
1031                 goto out;
1032
1033         /*
1034          * Failure's ok, aliases are created on a best effort basis.  If a
1035          * tun user/consumer decides to rename the interface to conflict with
1036          * another device (non-ifnet) on the system, we will assume they know
1037          * what they are doing.  make_dev_alias_p won't touch tun_alias on
1038          * failure, so we use it but ignore the return value.
1039          */
1040         make_dev_alias_p(MAKEDEV_CHECKNAME, &tp->tun_alias, tp->tun_dev, "%s",
1041             ifp->if_xname);
1042 out:
1043         tun_unbusy(tp);
1044 }
1045
1046 static int
1047 tunopen(struct cdev *dev, int flag, int mode, struct thread *td)
1048 {
1049         struct ifnet    *ifp;
1050         struct tuntap_softc *tp;
1051         int error __diagused, tunflags;
1052
1053         tunflags = 0;
1054         CURVNET_SET(TD_TO_VNET(td));
1055         error = tuntap_name2info(dev->si_name, NULL, &tunflags);
1056         if (error != 0) {
1057                 CURVNET_RESTORE();
1058                 return (error); /* Shouldn't happen */
1059         }
1060
1061         tp = dev->si_drv1;
1062         KASSERT(tp != NULL,
1063             ("si_drv1 should have been initialized at creation"));
1064
1065         TUN_LOCK(tp);
1066         if ((tp->tun_flags & TUN_INITED) == 0) {
1067                 TUN_UNLOCK(tp);
1068                 CURVNET_RESTORE();
1069                 return (ENXIO);
1070         }
1071         if ((tp->tun_flags & (TUN_OPEN | TUN_DYING)) != 0) {
1072                 TUN_UNLOCK(tp);
1073                 CURVNET_RESTORE();
1074                 return (EBUSY);
1075         }
1076
1077         error = tun_busy_locked(tp);
1078         KASSERT(error == 0, ("Must be able to busy an unopen tunnel"));
1079         ifp = TUN2IFP(tp);
1080
1081         if ((tp->tun_flags & TUN_L2) != 0) {
1082                 bcopy(IF_LLADDR(ifp), tp->tun_ether.octet,
1083                     sizeof(tp->tun_ether.octet));
1084
1085                 ifp->if_drv_flags |= IFF_DRV_RUNNING;
1086                 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1087
1088                 if (tapuponopen)
1089                         ifp->if_flags |= IFF_UP;
1090         }
1091
1092         tp->tun_pid = td->td_proc->p_pid;
1093         tp->tun_flags |= TUN_OPEN;
1094
1095         if_link_state_change(ifp, LINK_STATE_UP);
1096         TUNDEBUG(ifp, "open\n");
1097         TUN_UNLOCK(tp);
1098
1099         /*
1100          * This can fail with either ENOENT or EBUSY.  This is in the middle of
1101          * d_open, so ENOENT should not be possible.  EBUSY is possible, but
1102          * the only cdevpriv dtor being set will be tundtor and the softc being
1103          * passed is constant for a given cdev.  We ignore the possible error
1104          * because of this as either "unlikely" or "not actually a problem."
1105          */
1106         (void)devfs_set_cdevpriv(tp, tundtor);
1107         CURVNET_RESTORE();
1108         return (0);
1109 }
1110
1111 /*
1112  * tundtor - tear down the device - mark i/f down & delete
1113  * routing info
1114  */
1115 static void
1116 tundtor(void *data)
1117 {
1118         struct proc *p;
1119         struct tuntap_softc *tp;
1120         struct ifnet *ifp;
1121         bool l2tun;
1122
1123         tp = data;
1124         p = curproc;
1125         ifp = TUN2IFP(tp);
1126
1127         TUN_LOCK(tp);
1128
1129         /*
1130          * Realistically, we can't be obstinate here.  This only means that the
1131          * tuntap device was closed out of order, and the last closer wasn't the
1132          * controller.  These are still good to know about, though, as software
1133          * should avoid multiple processes with a tuntap device open and
1134          * ill-defined transfer of control (e.g., handoff, TUNSIFPID, close in
1135          * parent).
1136          */
1137         if (p->p_pid != tp->tun_pid) {
1138                 log(LOG_INFO,
1139                     "pid %d (%s), %s: tun/tap protocol violation, non-controlling process closed last.\n",
1140                     p->p_pid, p->p_comm, tp->tun_dev->si_name);
1141         }
1142
1143         /*
1144          * junk all pending output
1145          */
1146         CURVNET_SET(ifp->if_vnet);
1147
1148         l2tun = false;
1149         if ((tp->tun_flags & TUN_L2) != 0) {
1150                 l2tun = true;
1151                 IF_DRAIN(&ifp->if_snd);
1152         } else {
1153                 IFQ_PURGE(&ifp->if_snd);
1154         }
1155
1156         /* For vmnet, we won't do most of the address/route bits */
1157         if ((tp->tun_flags & TUN_VMNET) != 0 ||
1158             (l2tun && (ifp->if_flags & IFF_LINK0) != 0))
1159                 goto out;
1160
1161         if (ifp->if_flags & IFF_UP) {
1162                 TUN_UNLOCK(tp);
1163                 if_down(ifp);
1164                 TUN_LOCK(tp);
1165         }
1166
1167         /* Delete all addresses and routes which reference this interface. */
1168         if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
1169                 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1170                 TUN_UNLOCK(tp);
1171                 if_purgeaddrs(ifp);
1172                 TUN_LOCK(tp);
1173         }
1174
1175 out:
1176         if_link_state_change(ifp, LINK_STATE_DOWN);
1177         CURVNET_RESTORE();
1178
1179         funsetown(&tp->tun_sigio);
1180         selwakeuppri(&tp->tun_rsel, PZERO + 1);
1181         KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
1182         TUNDEBUG (ifp, "closed\n");
1183         tp->tun_flags &= ~TUN_OPEN;
1184         tp->tun_pid = 0;
1185         tun_vnethdr_set(ifp, 0);
1186
1187         tun_unbusy_locked(tp);
1188         TUN_UNLOCK(tp);
1189 }
1190
1191 static void
1192 tuninit(struct ifnet *ifp)
1193 {
1194         struct tuntap_softc *tp = ifp->if_softc;
1195
1196         TUNDEBUG(ifp, "tuninit\n");
1197
1198         TUN_LOCK(tp);
1199         ifp->if_drv_flags |= IFF_DRV_RUNNING;
1200         if ((tp->tun_flags & TUN_L2) == 0) {
1201                 ifp->if_flags |= IFF_UP;
1202                 getmicrotime(&ifp->if_lastchange);
1203                 TUN_UNLOCK(tp);
1204         } else {
1205                 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1206                 TUN_UNLOCK(tp);
1207                 /* attempt to start output */
1208                 tunstart_l2(ifp);
1209         }
1210
1211 }
1212
1213 /*
1214  * Used only for l2 tunnel.
1215  */
1216 static void
1217 tunifinit(void *xtp)
1218 {
1219         struct tuntap_softc *tp;
1220
1221         tp = (struct tuntap_softc *)xtp;
1222         tuninit(tp->tun_ifp);
1223 }
1224
1225 /*
1226  * To be called under TUN_LOCK. Update ifp->if_hwassist according to the
1227  * current value of ifp->if_capenable.
1228  */
1229 static void
1230 tun_caps_changed(struct ifnet *ifp)
1231 {
1232         uint64_t hwassist = 0;
1233
1234         TUN_LOCK_ASSERT((struct tuntap_softc *)ifp->if_softc);
1235         if (ifp->if_capenable & IFCAP_TXCSUM)
1236                 hwassist |= CSUM_TCP | CSUM_UDP;
1237         if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
1238                 hwassist |= CSUM_TCP_IPV6
1239                     | CSUM_UDP_IPV6;
1240         if (ifp->if_capenable & IFCAP_TSO4)
1241                 hwassist |= CSUM_IP_TSO;
1242         if (ifp->if_capenable & IFCAP_TSO6)
1243                 hwassist |= CSUM_IP6_TSO;
1244         ifp->if_hwassist = hwassist;
1245 }
1246
1247 /*
1248  * To be called under TUN_LOCK. Update tp->tun_vhdrlen and adjust
1249  * if_capabilities and if_capenable as needed.
1250  */
1251 static void
1252 tun_vnethdr_set(struct ifnet *ifp, int vhdrlen)
1253 {
1254         struct tuntap_softc *tp = ifp->if_softc;
1255
1256         TUN_LOCK_ASSERT(tp);
1257
1258         if (tp->tun_vhdrlen == vhdrlen)
1259                 return;
1260
1261         /*
1262          * Update if_capabilities to reflect the
1263          * functionalities offered by the virtio-net
1264          * header.
1265          */
1266         if (vhdrlen != 0)
1267                 ifp->if_capabilities |=
1268                         TAP_VNET_HDR_CAPS;
1269         else
1270                 ifp->if_capabilities &=
1271                         ~TAP_VNET_HDR_CAPS;
1272         /*
1273          * Disable any capabilities that we don't
1274          * support anymore.
1275          */
1276         ifp->if_capenable &= ifp->if_capabilities;
1277         tun_caps_changed(ifp);
1278         tp->tun_vhdrlen = vhdrlen;
1279
1280         TUNDEBUG(ifp, "vnet_hdr_len=%d, if_capabilities=%x\n",
1281             vhdrlen, ifp->if_capabilities);
1282 }
1283
1284 /*
1285  * Process an ioctl request.
1286  */
1287 static int
1288 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1289 {
1290         struct ifreq *ifr = (struct ifreq *)data;
1291         struct tuntap_softc *tp;
1292         struct ifstat *ifs;
1293         struct ifmediareq       *ifmr;
1294         int             dummy, error = 0;
1295         bool            l2tun;
1296
1297         ifmr = NULL;
1298         sx_xlock(&tun_ioctl_sx);
1299         tp = ifp->if_softc;
1300         if (tp == NULL) {
1301                 error = ENXIO;
1302                 goto bad;
1303         }
1304         l2tun = (tp->tun_flags & TUN_L2) != 0;
1305         switch(cmd) {
1306         case SIOCGIFSTATUS:
1307                 ifs = (struct ifstat *)data;
1308                 TUN_LOCK(tp);
1309                 if (tp->tun_pid)
1310                         snprintf(ifs->ascii, sizeof(ifs->ascii),
1311                             "\tOpened by PID %d\n", tp->tun_pid);
1312                 else
1313                         ifs->ascii[0] = '\0';
1314                 TUN_UNLOCK(tp);
1315                 break;
1316         case SIOCSIFADDR:
1317                 if (l2tun)
1318                         error = ether_ioctl(ifp, cmd, data);
1319                 else
1320                         tuninit(ifp);
1321                 if (error == 0)
1322                     TUNDEBUG(ifp, "address set\n");
1323                 break;
1324         case SIOCSIFMTU:
1325                 ifp->if_mtu = ifr->ifr_mtu;
1326                 TUNDEBUG(ifp, "mtu set\n");
1327                 break;
1328         case SIOCSIFFLAGS:
1329         case SIOCADDMULTI:
1330         case SIOCDELMULTI:
1331                 break;
1332         case SIOCGIFMEDIA:
1333                 if (!l2tun) {
1334                         error = EINVAL;
1335                         break;
1336                 }
1337
1338                 ifmr = (struct ifmediareq *)data;
1339                 dummy = ifmr->ifm_count;
1340                 ifmr->ifm_count = 1;
1341                 ifmr->ifm_status = IFM_AVALID;
1342                 ifmr->ifm_active = IFM_ETHER | IFM_FDX | IFM_1000_T;
1343                 if (tp->tun_flags & TUN_OPEN)
1344                         ifmr->ifm_status |= IFM_ACTIVE;
1345                 ifmr->ifm_current = ifmr->ifm_active;
1346                 if (dummy >= 1) {
1347                         int media = IFM_ETHER;
1348                         error = copyout(&media, ifmr->ifm_ulist, sizeof(int));
1349                 }
1350                 break;
1351         case SIOCSIFCAP:
1352                 TUN_LOCK(tp);
1353                 ifp->if_capenable = ifr->ifr_reqcap;
1354                 tun_caps_changed(ifp);
1355                 TUN_UNLOCK(tp);
1356                 VLAN_CAPABILITIES(ifp);
1357                 break;
1358         default:
1359                 if (l2tun) {
1360                         error = ether_ioctl(ifp, cmd, data);
1361                 } else {
1362                         error = EINVAL;
1363                 }
1364         }
1365 bad:
1366         sx_xunlock(&tun_ioctl_sx);
1367         return (error);
1368 }
1369
1370 /*
1371  * tunoutput - queue packets from higher level ready to put out.
1372  */
1373 static int
1374 tunoutput(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
1375     struct route *ro)
1376 {
1377         struct tuntap_softc *tp = ifp->if_softc;
1378         u_short cached_tun_flags;
1379         int error;
1380         u_int32_t af;
1381
1382         TUNDEBUG (ifp, "tunoutput\n");
1383
1384 #ifdef MAC
1385         error = mac_ifnet_check_transmit(ifp, m0);
1386         if (error) {
1387                 m_freem(m0);
1388                 return (error);
1389         }
1390 #endif
1391
1392         /* Could be unlocked read? */
1393         TUN_LOCK(tp);
1394         cached_tun_flags = tp->tun_flags;
1395         TUN_UNLOCK(tp);
1396         if ((cached_tun_flags & TUN_READY) != TUN_READY) {
1397                 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
1398                 m_freem (m0);
1399                 return (EHOSTDOWN);
1400         }
1401
1402         if ((ifp->if_flags & IFF_UP) != IFF_UP) {
1403                 m_freem (m0);
1404                 return (EHOSTDOWN);
1405         }
1406
1407         /* BPF writes need to be handled specially. */
1408         if (dst->sa_family == AF_UNSPEC)
1409                 bcopy(dst->sa_data, &af, sizeof(af));
1410         else
1411                 af = RO_GET_FAMILY(ro, dst);
1412
1413         if (bpf_peers_present(ifp->if_bpf))
1414                 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m0);
1415
1416         /* prepend sockaddr? this may abort if the mbuf allocation fails */
1417         if (cached_tun_flags & TUN_LMODE) {
1418                 /* allocate space for sockaddr */
1419                 M_PREPEND(m0, dst->sa_len, M_NOWAIT);
1420
1421                 /* if allocation failed drop packet */
1422                 if (m0 == NULL) {
1423                         if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1424                         if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1425                         return (ENOBUFS);
1426                 } else {
1427                         bcopy(dst, m0->m_data, dst->sa_len);
1428                 }
1429         }
1430
1431         if (cached_tun_flags & TUN_IFHEAD) {
1432                 /* Prepend the address family */
1433                 M_PREPEND(m0, 4, M_NOWAIT);
1434
1435                 /* if allocation failed drop packet */
1436                 if (m0 == NULL) {
1437                         if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1438                         if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1439                         return (ENOBUFS);
1440                 } else
1441                         *(u_int32_t *)m0->m_data = htonl(af);
1442         } else {
1443 #ifdef INET
1444                 if (af != AF_INET)
1445 #endif
1446                 {
1447                         m_freem(m0);
1448                         return (EAFNOSUPPORT);
1449                 }
1450         }
1451
1452         error = (ifp->if_transmit)(ifp, m0);
1453         if (error)
1454                 return (ENOBUFS);
1455         if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
1456         return (0);
1457 }
1458
1459 /*
1460  * the cdevsw interface is now pretty minimal.
1461  */
1462 static  int
1463 tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag,
1464     struct thread *td)
1465 {
1466         struct ifreq ifr, *ifrp;
1467         struct tuntap_softc *tp = dev->si_drv1;
1468         struct ifnet *ifp = TUN2IFP(tp);
1469         struct tuninfo *tunp;
1470         int error, iflags, ival;
1471         bool    l2tun;
1472
1473         l2tun = (tp->tun_flags & TUN_L2) != 0;
1474         if (l2tun) {
1475                 /* tap specific ioctls */
1476                 switch(cmd) {
1477                 /* VMware/VMnet port ioctl's */
1478 #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
1479     defined(COMPAT_FREEBSD4)
1480                 case _IO('V', 0):
1481                         ival = IOCPARM_IVAL(data);
1482                         data = (caddr_t)&ival;
1483                         /* FALLTHROUGH */
1484 #endif
1485                 case VMIO_SIOCSIFFLAGS: /* VMware/VMnet SIOCSIFFLAGS */
1486                         iflags = *(int *)data;
1487                         iflags &= TUN_VMIO_FLAG_MASK;
1488                         iflags &= ~IFF_CANTCHANGE;
1489                         iflags |= IFF_UP;
1490
1491                         TUN_LOCK(tp);
1492                         ifp->if_flags = iflags |
1493                             (ifp->if_flags & IFF_CANTCHANGE);
1494                         TUN_UNLOCK(tp);
1495
1496                         return (0);
1497                 case SIOCGIFADDR:       /* get MAC address of the remote side */
1498                         TUN_LOCK(tp);
1499                         bcopy(&tp->tun_ether.octet, data,
1500                             sizeof(tp->tun_ether.octet));
1501                         TUN_UNLOCK(tp);
1502
1503                         return (0);
1504                 case SIOCSIFADDR:       /* set MAC address of the remote side */
1505                         TUN_LOCK(tp);
1506                         bcopy(data, &tp->tun_ether.octet,
1507                             sizeof(tp->tun_ether.octet));
1508                         TUN_UNLOCK(tp);
1509
1510                         return (0);
1511                 case TAPSVNETHDR:
1512                         ival = *(int *)data;
1513                         if (ival != 0 &&
1514                             ival != sizeof(struct virtio_net_hdr) &&
1515                             ival != sizeof(struct virtio_net_hdr_mrg_rxbuf)) {
1516                                 return (EINVAL);
1517                         }
1518                         TUN_LOCK(tp);
1519                         tun_vnethdr_set(ifp, ival);
1520                         TUN_UNLOCK(tp);
1521
1522                         return (0);
1523                 case TAPGVNETHDR:
1524                         TUN_LOCK(tp);
1525                         *(int *)data = tp->tun_vhdrlen;
1526                         TUN_UNLOCK(tp);
1527
1528                         return (0);
1529                 }
1530
1531                 /* Fall through to the common ioctls if unhandled */
1532         } else {
1533                 switch (cmd) {
1534                 case TUNSLMODE:
1535                         TUN_LOCK(tp);
1536                         if (*(int *)data) {
1537                                 tp->tun_flags |= TUN_LMODE;
1538                                 tp->tun_flags &= ~TUN_IFHEAD;
1539                         } else
1540                                 tp->tun_flags &= ~TUN_LMODE;
1541                         TUN_UNLOCK(tp);
1542
1543                         return (0);
1544                 case TUNSIFHEAD:
1545                         TUN_LOCK(tp);
1546                         if (*(int *)data) {
1547                                 tp->tun_flags |= TUN_IFHEAD;
1548                                 tp->tun_flags &= ~TUN_LMODE;
1549                         } else
1550                                 tp->tun_flags &= ~TUN_IFHEAD;
1551                         TUN_UNLOCK(tp);
1552
1553                         return (0);
1554                 case TUNGIFHEAD:
1555                         TUN_LOCK(tp);
1556                         *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
1557                         TUN_UNLOCK(tp);
1558
1559                         return (0);
1560                 case TUNSIFMODE:
1561                         /* deny this if UP */
1562                         if (TUN2IFP(tp)->if_flags & IFF_UP)
1563                                 return (EBUSY);
1564
1565                         switch (*(int *)data & ~IFF_MULTICAST) {
1566                         case IFF_POINTOPOINT:
1567                         case IFF_BROADCAST:
1568                                 TUN_LOCK(tp);
1569                                 TUN2IFP(tp)->if_flags &=
1570                                     ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
1571                                 TUN2IFP(tp)->if_flags |= *(int *)data;
1572                                 TUN_UNLOCK(tp);
1573
1574                                 break;
1575                         default:
1576                                 return (EINVAL);
1577                         }
1578
1579                         return (0);
1580                 case TUNSIFPID:
1581                         TUN_LOCK(tp);
1582                         tp->tun_pid = curthread->td_proc->p_pid;
1583                         TUN_UNLOCK(tp);
1584
1585                         return (0);
1586                 }
1587                 /* Fall through to the common ioctls if unhandled */
1588         }
1589
1590         switch (cmd) {
1591         case TUNGIFNAME:
1592                 ifrp = (struct ifreq *)data;
1593                 strlcpy(ifrp->ifr_name, TUN2IFP(tp)->if_xname, IFNAMSIZ);
1594
1595                 return (0);
1596         case TUNSIFINFO:
1597                 tunp = (struct tuninfo *)data;
1598                 if (TUN2IFP(tp)->if_type != tunp->type)
1599                         return (EPROTOTYPE);
1600                 TUN_LOCK(tp);
1601                 if (TUN2IFP(tp)->if_mtu != tunp->mtu) {
1602                         strlcpy(ifr.ifr_name, if_name(TUN2IFP(tp)), IFNAMSIZ);
1603                         ifr.ifr_mtu = tunp->mtu;
1604                         CURVNET_SET(TUN2IFP(tp)->if_vnet);
1605                         error = ifhwioctl(SIOCSIFMTU, TUN2IFP(tp),
1606                             (caddr_t)&ifr, td);
1607                         CURVNET_RESTORE();
1608                         if (error) {
1609                                 TUN_UNLOCK(tp);
1610                                 return (error);
1611                         }
1612                 }
1613                 TUN2IFP(tp)->if_baudrate = tunp->baudrate;
1614                 TUN_UNLOCK(tp);
1615                 break;
1616         case TUNGIFINFO:
1617                 tunp = (struct tuninfo *)data;
1618                 TUN_LOCK(tp);
1619                 tunp->mtu = TUN2IFP(tp)->if_mtu;
1620                 tunp->type = TUN2IFP(tp)->if_type;
1621                 tunp->baudrate = TUN2IFP(tp)->if_baudrate;
1622                 TUN_UNLOCK(tp);
1623                 break;
1624         case TUNSDEBUG:
1625                 tundebug = *(int *)data;
1626                 break;
1627         case TUNGDEBUG:
1628                 *(int *)data = tundebug;
1629                 break;
1630         case FIONBIO:
1631                 break;
1632         case FIOASYNC:
1633                 TUN_LOCK(tp);
1634                 if (*(int *)data)
1635                         tp->tun_flags |= TUN_ASYNC;
1636                 else
1637                         tp->tun_flags &= ~TUN_ASYNC;
1638                 TUN_UNLOCK(tp);
1639                 break;
1640         case FIONREAD:
1641                 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) {
1642                         struct mbuf *mb;
1643                         IFQ_LOCK(&TUN2IFP(tp)->if_snd);
1644                         IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb);
1645                         for (*(int *)data = 0; mb != NULL; mb = mb->m_next)
1646                                 *(int *)data += mb->m_len;
1647                         IFQ_UNLOCK(&TUN2IFP(tp)->if_snd);
1648                 } else
1649                         *(int *)data = 0;
1650                 break;
1651         case FIOSETOWN:
1652                 return (fsetown(*(int *)data, &tp->tun_sigio));
1653
1654         case FIOGETOWN:
1655                 *(int *)data = fgetown(&tp->tun_sigio);
1656                 return (0);
1657
1658         /* This is deprecated, FIOSETOWN should be used instead. */
1659         case TIOCSPGRP:
1660                 return (fsetown(-(*(int *)data), &tp->tun_sigio));
1661
1662         /* This is deprecated, FIOGETOWN should be used instead. */
1663         case TIOCGPGRP:
1664                 *(int *)data = -fgetown(&tp->tun_sigio);
1665                 return (0);
1666
1667         default:
1668                 return (ENOTTY);
1669         }
1670         return (0);
1671 }
1672
1673 /*
1674  * The cdevsw read interface - reads a packet at a time, or at
1675  * least as much of a packet as can be read.
1676  */
1677 static  int
1678 tunread(struct cdev *dev, struct uio *uio, int flag)
1679 {
1680         struct tuntap_softc *tp = dev->si_drv1;
1681         struct ifnet    *ifp = TUN2IFP(tp);
1682         struct mbuf     *m;
1683         size_t          len;
1684         int             error = 0;
1685
1686         TUNDEBUG (ifp, "read\n");
1687         TUN_LOCK(tp);
1688         if ((tp->tun_flags & TUN_READY) != TUN_READY) {
1689                 TUN_UNLOCK(tp);
1690                 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
1691                 return (EHOSTDOWN);
1692         }
1693
1694         tp->tun_flags &= ~TUN_RWAIT;
1695
1696         for (;;) {
1697                 IFQ_DEQUEUE(&ifp->if_snd, m);
1698                 if (m != NULL)
1699                         break;
1700                 if (flag & O_NONBLOCK) {
1701                         TUN_UNLOCK(tp);
1702                         return (EWOULDBLOCK);
1703                 }
1704                 tp->tun_flags |= TUN_RWAIT;
1705                 error = mtx_sleep(tp, &tp->tun_mtx, PCATCH | (PZERO + 1),
1706                     "tunread", 0);
1707                 if (error != 0) {
1708                         TUN_UNLOCK(tp);
1709                         return (error);
1710                 }
1711         }
1712         TUN_UNLOCK(tp);
1713
1714         if ((tp->tun_flags & TUN_L2) != 0)
1715                 BPF_MTAP(ifp, m);
1716
1717         len = min(tp->tun_vhdrlen, uio->uio_resid);
1718         if (len > 0) {
1719                 struct virtio_net_hdr_mrg_rxbuf vhdr;
1720
1721                 bzero(&vhdr, sizeof(vhdr));
1722                 if (m->m_pkthdr.csum_flags & TAP_ALL_OFFLOAD) {
1723                         m = virtio_net_tx_offload(ifp, m, false, &vhdr.hdr);
1724                 }
1725
1726                 TUNDEBUG(ifp, "txvhdr: f %u, gt %u, hl %u, "
1727                     "gs %u, cs %u, co %u\n", vhdr.hdr.flags,
1728                     vhdr.hdr.gso_type, vhdr.hdr.hdr_len,
1729                     vhdr.hdr.gso_size, vhdr.hdr.csum_start,
1730                     vhdr.hdr.csum_offset);
1731                 error = uiomove(&vhdr, len, uio);
1732         }
1733
1734         while (m && uio->uio_resid > 0 && error == 0) {
1735                 len = min(uio->uio_resid, m->m_len);
1736                 if (len != 0)
1737                         error = uiomove(mtod(m, void *), len, uio);
1738                 m = m_free(m);
1739         }
1740
1741         if (m) {
1742                 TUNDEBUG(ifp, "Dropping mbuf\n");
1743                 m_freem(m);
1744         }
1745         return (error);
1746 }
1747
1748 static int
1749 tunwrite_l2(struct tuntap_softc *tp, struct mbuf *m,
1750             struct virtio_net_hdr_mrg_rxbuf *vhdr)
1751 {
1752         struct epoch_tracker et;
1753         struct ether_header *eh;
1754         struct ifnet *ifp;
1755
1756         ifp = TUN2IFP(tp);
1757
1758         /*
1759          * Only pass a unicast frame to ether_input(), if it would
1760          * actually have been received by non-virtual hardware.
1761          */
1762         if (m->m_len < sizeof(struct ether_header)) {
1763                 m_freem(m);
1764                 return (0);
1765         }
1766
1767         eh = mtod(m, struct ether_header *);
1768
1769         if (eh && (ifp->if_flags & IFF_PROMISC) == 0 &&
1770             !ETHER_IS_MULTICAST(eh->ether_dhost) &&
1771             bcmp(eh->ether_dhost, IF_LLADDR(ifp), ETHER_ADDR_LEN) != 0) {
1772                 m_freem(m);
1773                 return (0);
1774         }
1775
1776         if (vhdr != NULL && virtio_net_rx_csum(m, &vhdr->hdr)) {
1777                 m_freem(m);
1778                 return (0);
1779         }
1780
1781         /* Pass packet up to parent. */
1782         CURVNET_SET(ifp->if_vnet);
1783         NET_EPOCH_ENTER(et);
1784         (*ifp->if_input)(ifp, m);
1785         NET_EPOCH_EXIT(et);
1786         CURVNET_RESTORE();
1787         /* ibytes are counted in parent */
1788         if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1789         return (0);
1790 }
1791
1792 static int
1793 tunwrite_l3(struct tuntap_softc *tp, struct mbuf *m)
1794 {
1795         struct epoch_tracker et;
1796         struct ifnet *ifp;
1797         int family, isr;
1798
1799         ifp = TUN2IFP(tp);
1800         /* Could be unlocked read? */
1801         TUN_LOCK(tp);
1802         if (tp->tun_flags & TUN_IFHEAD) {
1803                 TUN_UNLOCK(tp);
1804                 if (m->m_len < sizeof(family) &&
1805                 (m = m_pullup(m, sizeof(family))) == NULL)
1806                         return (ENOBUFS);
1807                 family = ntohl(*mtod(m, u_int32_t *));
1808                 m_adj(m, sizeof(family));
1809         } else {
1810                 TUN_UNLOCK(tp);
1811                 family = AF_INET;
1812         }
1813
1814         BPF_MTAP2(ifp, &family, sizeof(family), m);
1815
1816         switch (family) {
1817 #ifdef INET
1818         case AF_INET:
1819                 isr = NETISR_IP;
1820                 break;
1821 #endif
1822 #ifdef INET6
1823         case AF_INET6:
1824                 isr = NETISR_IPV6;
1825                 break;
1826 #endif
1827         default:
1828                 m_freem(m);
1829                 return (EAFNOSUPPORT);
1830         }
1831         random_harvest_queue(m, sizeof(*m), RANDOM_NET_TUN);
1832         if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
1833         if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1834         CURVNET_SET(ifp->if_vnet);
1835         M_SETFIB(m, ifp->if_fib);
1836         NET_EPOCH_ENTER(et);
1837         netisr_dispatch(isr, m);
1838         NET_EPOCH_EXIT(et);
1839         CURVNET_RESTORE();
1840         return (0);
1841 }
1842
1843 /*
1844  * the cdevsw write interface - an atomic write is a packet - or else!
1845  */
1846 static  int
1847 tunwrite(struct cdev *dev, struct uio *uio, int flag)
1848 {
1849         struct virtio_net_hdr_mrg_rxbuf vhdr;
1850         struct tuntap_softc *tp;
1851         struct ifnet    *ifp;
1852         struct mbuf     *m;
1853         uint32_t        mru;
1854         int             align, vhdrlen, error;
1855         bool            l2tun;
1856
1857         tp = dev->si_drv1;
1858         ifp = TUN2IFP(tp);
1859         TUNDEBUG(ifp, "tunwrite\n");
1860         if ((ifp->if_flags & IFF_UP) != IFF_UP)
1861                 /* ignore silently */
1862                 return (0);
1863
1864         if (uio->uio_resid == 0)
1865                 return (0);
1866
1867         l2tun = (tp->tun_flags & TUN_L2) != 0;
1868         mru = l2tun ? TAPMRU : TUNMRU;
1869         vhdrlen = tp->tun_vhdrlen;
1870         align = 0;
1871         if (l2tun) {
1872                 align = ETHER_ALIGN;
1873                 mru += vhdrlen;
1874         } else if ((tp->tun_flags & TUN_IFHEAD) != 0)
1875                 mru += sizeof(uint32_t);        /* family */
1876         if (uio->uio_resid < 0 || uio->uio_resid > mru) {
1877                 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid);
1878                 return (EIO);
1879         }
1880
1881         if (vhdrlen > 0) {
1882                 error = uiomove(&vhdr, vhdrlen, uio);
1883                 if (error != 0)
1884                         return (error);
1885                 TUNDEBUG(ifp, "txvhdr: f %u, gt %u, hl %u, "
1886                     "gs %u, cs %u, co %u\n", vhdr.hdr.flags,
1887                     vhdr.hdr.gso_type, vhdr.hdr.hdr_len,
1888                     vhdr.hdr.gso_size, vhdr.hdr.csum_start,
1889                     vhdr.hdr.csum_offset);
1890         }
1891
1892         if ((m = m_uiotombuf(uio, M_NOWAIT, 0, align, M_PKTHDR)) == NULL) {
1893                 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
1894                 return (ENOBUFS);
1895         }
1896
1897         m->m_pkthdr.rcvif = ifp;
1898 #ifdef MAC
1899         mac_ifnet_create_mbuf(ifp, m);
1900 #endif
1901
1902         if (l2tun)
1903                 return (tunwrite_l2(tp, m, vhdrlen > 0 ? &vhdr : NULL));
1904
1905         return (tunwrite_l3(tp, m));
1906 }
1907
1908 /*
1909  * tunpoll - the poll interface, this is only useful on reads
1910  * really. The write detect always returns true, write never blocks
1911  * anyway, it either accepts the packet or drops it.
1912  */
1913 static  int
1914 tunpoll(struct cdev *dev, int events, struct thread *td)
1915 {
1916         struct tuntap_softc *tp = dev->si_drv1;
1917         struct ifnet    *ifp = TUN2IFP(tp);
1918         int             revents = 0;
1919
1920         TUNDEBUG(ifp, "tunpoll\n");
1921
1922         if (events & (POLLIN | POLLRDNORM)) {
1923                 IFQ_LOCK(&ifp->if_snd);
1924                 if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
1925                         TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len);
1926                         revents |= events & (POLLIN | POLLRDNORM);
1927                 } else {
1928                         TUNDEBUG(ifp, "tunpoll waiting\n");
1929                         selrecord(td, &tp->tun_rsel);
1930                 }
1931                 IFQ_UNLOCK(&ifp->if_snd);
1932         }
1933         revents |= events & (POLLOUT | POLLWRNORM);
1934
1935         return (revents);
1936 }
1937
1938 /*
1939  * tunkqfilter - support for the kevent() system call.
1940  */
1941 static int
1942 tunkqfilter(struct cdev *dev, struct knote *kn)
1943 {
1944         struct tuntap_softc     *tp = dev->si_drv1;
1945         struct ifnet    *ifp = TUN2IFP(tp);
1946
1947         switch(kn->kn_filter) {
1948         case EVFILT_READ:
1949                 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n",
1950                     ifp->if_xname, dev2unit(dev));
1951                 kn->kn_fop = &tun_read_filterops;
1952                 break;
1953
1954         case EVFILT_WRITE:
1955                 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n",
1956                     ifp->if_xname, dev2unit(dev));
1957                 kn->kn_fop = &tun_write_filterops;
1958                 break;
1959
1960         default:
1961                 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n",
1962                     ifp->if_xname, dev2unit(dev));
1963                 return(EINVAL);
1964         }
1965
1966         kn->kn_hook = tp;
1967         knlist_add(&tp->tun_rsel.si_note, kn, 0);
1968
1969         return (0);
1970 }
1971
1972 /*
1973  * Return true of there is data in the interface queue.
1974  */
1975 static int
1976 tunkqread(struct knote *kn, long hint)
1977 {
1978         int                     ret;
1979         struct tuntap_softc     *tp = kn->kn_hook;
1980         struct cdev             *dev = tp->tun_dev;
1981         struct ifnet    *ifp = TUN2IFP(tp);
1982
1983         if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) {
1984                 TUNDEBUG(ifp,
1985                     "%s have data in the queue.  Len = %d, minor = %#x\n",
1986                     ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev));
1987                 ret = 1;
1988         } else {
1989                 TUNDEBUG(ifp,
1990                     "%s waiting for data, minor = %#x\n", ifp->if_xname,
1991                     dev2unit(dev));
1992                 ret = 0;
1993         }
1994
1995         return (ret);
1996 }
1997
1998 /*
1999  * Always can write, always return MTU in kn->data.
2000  */
2001 static int
2002 tunkqwrite(struct knote *kn, long hint)
2003 {
2004         struct tuntap_softc     *tp = kn->kn_hook;
2005         struct ifnet    *ifp = TUN2IFP(tp);
2006
2007         kn->kn_data = ifp->if_mtu;
2008
2009         return (1);
2010 }
2011
2012 static void
2013 tunkqdetach(struct knote *kn)
2014 {
2015         struct tuntap_softc     *tp = kn->kn_hook;
2016
2017         knlist_remove(&tp->tun_rsel.si_note, kn, 0);
2018 }