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                 dev_ref(dev);
 552                 tuncreate(dev);
 553                 struct tuntap_softc *tp = dev->si_drv1;
 554                 *ifpp = tp->tun_ifp;
 555         }
 556
 557         return (i);
 558 }
 559
 560 static void
 561 tunclone(void *arg, struct ucred *cred, char *name, int namelen,
 562     struct cdev **dev)
 563 {
 564         char devname[SPECNAMELEN + 1];
 565         struct tuntap_driver *drv;
 566         int append_unit, i, u, tunflags;
 567         bool mayclone;
 568
 569         if (*dev != NULL)
 570                 return;
 571
 572         tunflags = 0;
 573         CURVNET_SET(CRED_TO_VNET(cred));
 574         if (tuntap_name2info(name, &u, &tunflags) != 0)
 575                 goto out;       /* Not recognized */
 576
 577         if (u != -1 && u > IF_MAXUNIT)
 578                 goto out;       /* Unit number too high */
 579
 580         mayclone = priv_check_cred(cred, PRIV_NET_IFCREATE) == 0;
 581         if ((tunflags & TUN_L2) != 0) {
 582                 /* tap/vmnet allow user open with a sysctl */
 583                 mayclone = (mayclone || tap_allow_uopen) && tapdclone;
 584         } else {
 585                 mayclone = mayclone && tundclone;
 586         }
 587
 588         /*
 589          * If tun cloning is enabled, only the superuser can create an
 590          * interface.
 591          */
 592         if (!mayclone)
 593                 goto out;
 594
 595         if (u == -1)
 596                 append_unit = 1;
 597         else
 598                 append_unit = 0;
 599
 600         drv = tuntap_driver_from_flags(tunflags);
 601         if (drv == NULL)
 602                 goto out;
 603
 604         /* find any existing device, or allocate new unit number */
 605         i = clone_create(&drv->clones, &drv->cdevsw, &u, dev, 0);
 606         if (i) {
 607                 if (append_unit) {
 608                         namelen = snprintf(devname, sizeof(devname), "%s%d",
 609                             name, u);
 610                         name = devname;
 611                 }
 612
 613                 i = tun_create_device(drv, u, cred, dev, name);
 614         }
 615         if (i == 0) {
 616                 dev_ref(*dev);
 617                 if_clone_create(name, namelen, NULL);
 618         }
 619 out:
 620         CURVNET_RESTORE();
 621 }
 622
 623 static void
 624 tun_destroy(struct tuntap_softc *tp)
 625 {
 626
 627         TUN_LOCK(tp);
 628         tp->tun_flags |= TUN_DYING;
 629         if (tp->tun_busy != 0)
 630                 cv_wait_unlock(&tp->tun_cv, &tp->tun_mtx);
 631         else
 632                 TUN_UNLOCK(tp);
 633
 634         CURVNET_SET(TUN2IFP(tp)->if_vnet);
 635
 636         /* destroy_dev will take care of any alias. */
 637         destroy_dev(tp->tun_dev);
 638         seldrain(&tp->tun_rsel);
 639         knlist_clear(&tp->tun_rsel.si_note, 0);
 640         knlist_destroy(&tp->tun_rsel.si_note);
 641         if ((tp->tun_flags & TUN_L2) != 0) {
 642                 ether_ifdetach(TUN2IFP(tp));
 643         } else {
 644                 bpfdetach(TUN2IFP(tp));
 645                 if_detach(TUN2IFP(tp));
 646         }
 647         sx_xlock(&tun_ioctl_sx);
 648         TUN2IFP(tp)->if_softc = NULL;
 649         sx_xunlock(&tun_ioctl_sx);
 650         free_unr(tp->tun_drv->unrhdr, TUN2IFP(tp)->if_dunit);
 651         if_free(TUN2IFP(tp));
 652         mtx_destroy(&tp->tun_mtx);
 653         cv_destroy(&tp->tun_cv);
 654         free(tp, M_TUN);
 655         CURVNET_RESTORE();
 656 }
 657
 658 static int
 659 tun_clone_destroy(struct if_clone *ifc __unused, struct ifnet *ifp, uint32_t flags)
 660 {
 661         struct tuntap_softc *tp = ifp->if_softc;
 662
 663         mtx_lock(&tunmtx);
 664         TAILQ_REMOVE(&tunhead, tp, tun_list);
 665         mtx_unlock(&tunmtx);
 666         tun_destroy(tp);
 667
 668         return (0);
 669 }
 670
 671 static void
 672 vnet_tun_init(const void *unused __unused)
 673 {
 674         struct tuntap_driver *drv;
 675         struct tuntap_driver_cloner *drvc;
 676         int i;
 677
 678         for (i = 0; i < nitems(tuntap_drivers); ++i) {
 679                 drv = &tuntap_drivers[i];
 680                 drvc = malloc(sizeof(*drvc), M_TUN, M_WAITOK | M_ZERO);
 681
 682                 drvc->drv = drv;
 683                 struct if_clone_addreq req = {
 684                         .match_f = drv->clone_match_fn,
 685                         .create_f = drv->clone_create_fn,
 686                         .destroy_f = drv->clone_destroy_fn,
 687                 };
 688                 drvc->cloner = ifc_attach_cloner(drv->cdevsw.d_name, &req);
 689                 SLIST_INSERT_HEAD(&V_tuntap_driver_cloners, drvc, link);
 690         };
 691 }
 692 VNET_SYSINIT(vnet_tun_init, SI_SUB_PROTO_IF, SI_ORDER_ANY,
 693                 vnet_tun_init, NULL);
 694
 695 static void
 696 vnet_tun_uninit(const void *unused __unused)
 697 {
 698         struct tuntap_driver_cloner *drvc;
 699
 700         while (!SLIST_EMPTY(&V_tuntap_driver_cloners)) {
 701                 drvc = SLIST_FIRST(&V_tuntap_driver_cloners);
 702                 SLIST_REMOVE_HEAD(&V_tuntap_driver_cloners, link);
 703
 704                 if_clone_detach(drvc->cloner);
 705                 free(drvc, M_TUN);
 706         }
 707 }
 708 VNET_SYSUNINIT(vnet_tun_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY,
 709     vnet_tun_uninit, NULL);
 710
 711 static void
 712 tun_uninit(const void *unused __unused)
 713 {
 714         struct tuntap_driver *drv;
 715         struct tuntap_softc *tp;
 716         int i;
 717
 718         EVENTHANDLER_DEREGISTER(ifnet_arrival_event, arrival_tag);
 719         EVENTHANDLER_DEREGISTER(dev_clone, clone_tag);
 720
 721         mtx_lock(&tunmtx);
 722         while ((tp = TAILQ_FIRST(&tunhead)) != NULL) {
 723                 TAILQ_REMOVE(&tunhead, tp, tun_list);
 724                 mtx_unlock(&tunmtx);
 725                 tun_destroy(tp);
 726                 mtx_lock(&tunmtx);
 727         }
 728         mtx_unlock(&tunmtx);
 729         for (i = 0; i < nitems(tuntap_drivers); ++i) {
 730                 drv = &tuntap_drivers[i];
 731                 delete_unrhdr(drv->unrhdr);
 732                 clone_cleanup(&drv->clones);
 733         }
 734         mtx_destroy(&tunmtx);
 735 }
 736 SYSUNINIT(tun_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY, tun_uninit, NULL);
 737
 738 static struct tuntap_driver *
 739 tuntap_driver_from_ifnet(const struct ifnet *ifp)
 740 {
 741         struct tuntap_driver *drv;
 742         int i;
 743
 744         if (ifp == NULL)
 745                 return (NULL);
 746
 747         for (i = 0; i < nitems(tuntap_drivers); ++i) {
 748                 drv = &tuntap_drivers[i];
 749                 if (strcmp(ifp->if_dname, drv->cdevsw.d_name) == 0)
 750                         return (drv);
 751         }
 752
 753         return (NULL);
 754 }
 755
 756 static int
 757 tuntapmodevent(module_t mod, int type, void *data)
 758 {
 759         struct tuntap_driver *drv;
 760         int i;
 761
 762         switch (type) {
 763         case MOD_LOAD:
 764                 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF);
 765                 for (i = 0; i < nitems(tuntap_drivers); ++i) {
 766                         drv = &tuntap_drivers[i];
 767                         clone_setup(&drv->clones);
 768                         drv->unrhdr = new_unrhdr(0, IF_MAXUNIT, &tunmtx);
 769                 }
 770                 arrival_tag = EVENTHANDLER_REGISTER(ifnet_arrival_event,
 771                    tunrename, 0, 1000);
 772                 if (arrival_tag == NULL)
 773                         return (ENOMEM);
 774                 clone_tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000);
 775                 if (clone_tag == NULL)
 776                         return (ENOMEM);
 777                 break;
 778         case MOD_UNLOAD:
 779                 /* See tun_uninit, so it's done after the vnet_sysuninit() */
 780                 break;
 781         default:
 782                 return EOPNOTSUPP;
 783         }
 784         return 0;
 785 }
 786
 787 static moduledata_t tuntap_mod = {
 788         "if_tuntap",
 789         tuntapmodevent,
 790         0
 791 };
 792
 793 /* We'll only ever have these two, so no need for a macro. */
 794 static moduledata_t tun_mod = { "if_tun", NULL, 0 };
 795 static moduledata_t tap_mod = { "if_tap", NULL, 0 };
 796
 797 DECLARE_MODULE(if_tuntap, tuntap_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 798 MODULE_VERSION(if_tuntap, 1);
 799 DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 800 MODULE_VERSION(if_tun, 1);
 801 DECLARE_MODULE(if_tap, tap_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 802 MODULE_VERSION(if_tap, 1);
 803
 804 static int
 805 tun_create_device(struct tuntap_driver *drv, int unit, struct ucred *cr,
 806     struct cdev **dev, const char *name)
 807 {
 808         struct make_dev_args args;
 809         struct tuntap_softc *tp;
 810         int error;
 811
 812         tp = malloc(sizeof(*tp), M_TUN, M_WAITOK | M_ZERO);
 813         mtx_init(&tp->tun_mtx, "tun_mtx", NULL, MTX_DEF);
 814         cv_init(&tp->tun_cv, "tun_condvar");
 815         tp->tun_flags = drv->ident_flags;
 816         tp->tun_drv = drv;
 817
 818         make_dev_args_init(&args);
 819         if (cr != NULL)
 820                 args.mda_flags = MAKEDEV_REF;
 821         args.mda_devsw = &drv->cdevsw;
 822         args.mda_cr = cr;
 823         args.mda_uid = UID_UUCP;
 824         args.mda_gid = GID_DIALER;
 825         args.mda_mode = 0600;
 826         args.mda_unit = unit;
 827         args.mda_si_drv1 = tp;
 828         error = make_dev_s(&args, dev, "%s", name);
 829         if (error != 0) {
 830                 free(tp, M_TUN);
 831                 return (error);
 832         }
 833
 834         KASSERT((*dev)->si_drv1 != NULL,
 835             ("Failed to set si_drv1 at %s creation", name));
 836         tp->tun_dev = *dev;
 837         knlist_init_mtx(&tp->tun_rsel.si_note, &tp->tun_mtx);
 838         mtx_lock(&tunmtx);
 839         TAILQ_INSERT_TAIL(&tunhead, tp, tun_list);
 840         mtx_unlock(&tunmtx);
 841         return (0);
 842 }
 843
 844 static void
 845 tunstart(struct ifnet *ifp)
 846 {
 847         struct tuntap_softc *tp = ifp->if_softc;
 848         struct mbuf *m;
 849
 850         TUNDEBUG(ifp, "starting\n");
 851         if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
 852                 IFQ_LOCK(&ifp->if_snd);
 853                 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
 854                 if (m == NULL) {
 855                         IFQ_UNLOCK(&ifp->if_snd);
 856                         return;
 857                 }
 858                 IFQ_UNLOCK(&ifp->if_snd);
 859         }
 860
 861         TUN_LOCK(tp);
 862         if (tp->tun_flags & TUN_RWAIT) {
 863                 tp->tun_flags &= ~TUN_RWAIT;
 864                 wakeup(tp);
 865         }
 866         selwakeuppri(&tp->tun_rsel, PZERO + 1);
 867         KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
 868         if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) {
 869                 TUN_UNLOCK(tp);
 870                 pgsigio(&tp->tun_sigio, SIGIO, 0);
 871         } else
 872                 TUN_UNLOCK(tp);
 873 }
 874
 875 /*
 876  * tunstart_l2
 877  *
 878  * queue packets from higher level ready to put out
 879  */
 880 static void
 881 tunstart_l2(struct ifnet *ifp)
 882 {
 883         struct tuntap_softc     *tp = ifp->if_softc;
 884
 885         TUNDEBUG(ifp, "starting\n");
 886
 887         /*
 888          * do not junk pending output if we are in VMnet mode.
 889          * XXX: can this do any harm because of queue overflow?
 890          */
 891
 892         TUN_LOCK(tp);
 893         if (((tp->tun_flags & TUN_VMNET) == 0) &&
 894             ((tp->tun_flags & TUN_READY) != TUN_READY)) {
 895                 struct mbuf *m;
 896
 897                 /* Unlocked read. */
 898                 TUNDEBUG(ifp, "not ready, tun_flags = 0x%x\n", tp->tun_flags);
 899
 900                 for (;;) {
 901                         IF_DEQUEUE(&ifp->if_snd, m);
 902                         if (m != NULL) {
 903                                 m_freem(m);
 904                                 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
 905                         } else
 906                                 break;
 907                 }
 908                 TUN_UNLOCK(tp);
 909
 910                 return;
 911         }
 912
 913         ifp->if_drv_flags |= IFF_DRV_OACTIVE;
 914
 915         if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
 916                 if (tp->tun_flags & TUN_RWAIT) {
 917                         tp->tun_flags &= ~TUN_RWAIT;
 918                         wakeup(tp);
 919                 }
 920
 921                 if ((tp->tun_flags & TUN_ASYNC) && (tp->tun_sigio != NULL)) {
 922                         TUN_UNLOCK(tp);
 923                         pgsigio(&tp->tun_sigio, SIGIO, 0);
 924                         TUN_LOCK(tp);
 925                 }
 926
 927                 selwakeuppri(&tp->tun_rsel, PZERO+1);
 928                 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
 929                 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); /* obytes are counted in ether_output */
 930         }
 931
 932         ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
 933         TUN_UNLOCK(tp);
 934 } /* tunstart_l2 */
 935
 936 /* XXX: should return an error code so it can fail. */
 937 static void
 938 tuncreate(struct cdev *dev)
 939 {
 940         struct tuntap_driver *drv;
 941         struct tuntap_softc *tp;
 942         struct ifnet *ifp;
 943         struct ether_addr eaddr;
 944         int iflags;
 945         u_char type;
 946
 947         tp = dev->si_drv1;
 948         KASSERT(tp != NULL,
 949             ("si_drv1 should have been initialized at creation"));
 950
 951         drv = tp->tun_drv;
 952         iflags = IFF_MULTICAST;
 953         if ((tp->tun_flags & TUN_L2) != 0) {
 954                 type = IFT_ETHER;
 955                 iflags |= IFF_BROADCAST | IFF_SIMPLEX;
 956         } else {
 957                 type = IFT_PPP;
 958                 iflags |= IFF_POINTOPOINT;
 959         }
 960         ifp = tp->tun_ifp = if_alloc(type);
 961         if (ifp == NULL)
 962                 panic("%s%d: failed to if_alloc() interface.\n",
 963                     drv->cdevsw.d_name, dev2unit(dev));
 964         ifp->if_softc = tp;
 965         if_initname(ifp, drv->cdevsw.d_name, dev2unit(dev));
 966         ifp->if_ioctl = tunifioctl;
 967         ifp->if_flags = iflags;
 968         IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
 969         ifp->if_capabilities |= IFCAP_LINKSTATE;
 970         ifp->if_capenable |= IFCAP_LINKSTATE;
 971
 972         if ((tp->tun_flags & TUN_L2) != 0) {
 973                 ifp->if_init = tunifinit;
 974                 ifp->if_start = tunstart_l2;
 975
 976                 ether_gen_addr(ifp, &eaddr);
 977                 ether_ifattach(ifp, eaddr.octet);
 978         } else {
 979                 ifp->if_mtu = TUNMTU;
 980                 ifp->if_start = tunstart;
 981                 ifp->if_output = tunoutput;
 982
 983                 ifp->if_snd.ifq_drv_maxlen = 0;
 984                 IFQ_SET_READY(&ifp->if_snd);
 985
 986                 if_attach(ifp);
 987                 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
 988         }
 989
 990         TUN_LOCK(tp);
 991         tp->tun_flags |= TUN_INITED;
 992         TUN_UNLOCK(tp);
 993
 994         TUNDEBUG(ifp, "interface %s is created, minor = %#x\n",
 995             ifp->if_xname, dev2unit(dev));
 996 }
 997
 998 static void
 999 tunrename(void *arg __unused, struct ifnet *ifp)
1000 {
1001         struct tuntap_softc *tp;
1002         int error;
1003
1004         if ((ifp->if_flags & IFF_RENAMING) == 0)
1005                 return;
1006
1007         if (tuntap_driver_from_ifnet(ifp) == NULL)
1008                 return;
1009
1010         /*
1011          * We need to grab the ioctl sx long enough to make sure the softc is
1012          * still there.  If it is, we can safely try to busy the tun device.
1013          * The busy may fail if the device is currently dying, in which case
1014          * we do nothing.  If it doesn't fail, the busy count stops the device
1015          * from dying until we've created the alias (that will then be
1016          * subsequently destroyed).
1017          */
1018         sx_xlock(&tun_ioctl_sx);
1019         tp = ifp->if_softc;
1020         if (tp == NULL) {
1021                 sx_xunlock(&tun_ioctl_sx);
1022                 return;
1023         }
1024         error = tun_busy(tp);
1025         sx_xunlock(&tun_ioctl_sx);
1026         if (error != 0)
1027                 return;
1028         if (tp->tun_alias != NULL) {
1029                 destroy_dev(tp->tun_alias);
1030                 tp->tun_alias = NULL;
1031         }
1032
1033         if (strcmp(ifp->if_xname, tp->tun_dev->si_name) == 0)
1034                 goto out;
1035
1036         /*
1037          * Failure's ok, aliases are created on a best effort basis.  If a
1038          * tun user/consumer decides to rename the interface to conflict with
1039          * another device (non-ifnet) on the system, we will assume they know
1040          * what they are doing.  make_dev_alias_p won't touch tun_alias on
1041          * failure, so we use it but ignore the return value.
1042          */
1043         make_dev_alias_p(MAKEDEV_CHECKNAME, &tp->tun_alias, tp->tun_dev, "%s",
1044             ifp->if_xname);
1045 out:
1046         tun_unbusy(tp);
1047 }
1048
1049 static int
1050 tunopen(struct cdev *dev, int flag, int mode, struct thread *td)
1051 {
1052         struct ifnet    *ifp;
1053         struct tuntap_softc *tp;
1054         int error __diagused, tunflags;
1055
1056         tunflags = 0;
1057         CURVNET_SET(TD_TO_VNET(td));
1058         error = tuntap_name2info(dev->si_name, NULL, &tunflags);
1059         if (error != 0) {
1060                 CURVNET_RESTORE();
1061                 return (error); /* Shouldn't happen */
1062         }
1063
1064         tp = dev->si_drv1;
1065         KASSERT(tp != NULL,
1066             ("si_drv1 should have been initialized at creation"));
1067
1068         TUN_LOCK(tp);
1069         if ((tp->tun_flags & TUN_INITED) == 0) {
1070                 TUN_UNLOCK(tp);
1071                 CURVNET_RESTORE();
1072                 return (ENXIO);
1073         }
1074         if ((tp->tun_flags & (TUN_OPEN | TUN_DYING)) != 0) {
1075                 TUN_UNLOCK(tp);
1076                 CURVNET_RESTORE();
1077                 return (EBUSY);
1078         }
1079
1080         error = tun_busy_locked(tp);
1081         KASSERT(error == 0, ("Must be able to busy an unopen tunnel"));
1082         ifp = TUN2IFP(tp);
1083
1084         if ((tp->tun_flags & TUN_L2) != 0) {
1085                 bcopy(IF_LLADDR(ifp), tp->tun_ether.octet,
1086                     sizeof(tp->tun_ether.octet));
1087
1088                 ifp->if_drv_flags |= IFF_DRV_RUNNING;
1089                 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1090
1091                 if (tapuponopen)
1092                         ifp->if_flags |= IFF_UP;
1093         }
1094
1095         tp->tun_pid = td->td_proc->p_pid;
1096         tp->tun_flags |= TUN_OPEN;
1097
1098         if_link_state_change(ifp, LINK_STATE_UP);
1099         TUNDEBUG(ifp, "open\n");
1100         TUN_UNLOCK(tp);
1101
1102         /*
1103          * This can fail with either ENOENT or EBUSY.  This is in the middle of
1104          * d_open, so ENOENT should not be possible.  EBUSY is possible, but
1105          * the only cdevpriv dtor being set will be tundtor and the softc being
1106          * passed is constant for a given cdev.  We ignore the possible error
1107          * because of this as either "unlikely" or "not actually a problem."
1108          */
1109         (void)devfs_set_cdevpriv(tp, tundtor);
1110         CURVNET_RESTORE();
1111         return (0);
1112 }
1113
1114 /*
1115  * tundtor - tear down the device - mark i/f down & delete
1116  * routing info
1117  */
1118 static void
1119 tundtor(void *data)
1120 {
1121         struct proc *p;
1122         struct tuntap_softc *tp;
1123         struct ifnet *ifp;
1124         bool l2tun;
1125
1126         tp = data;
1127         p = curproc;
1128         ifp = TUN2IFP(tp);
1129
1130         TUN_LOCK(tp);
1131
1132         /*
1133          * Realistically, we can't be obstinate here.  This only means that the
1134          * tuntap device was closed out of order, and the last closer wasn't the
1135          * controller.  These are still good to know about, though, as software
1136          * should avoid multiple processes with a tuntap device open and
1137          * ill-defined transfer of control (e.g., handoff, TUNSIFPID, close in
1138          * parent).
1139          */
1140         if (p->p_pid != tp->tun_pid) {
1141                 log(LOG_INFO,
1142                     "pid %d (%s), %s: tun/tap protocol violation, non-controlling process closed last.\n",
1143                     p->p_pid, p->p_comm, tp->tun_dev->si_name);
1144         }
1145
1146         /*
1147          * junk all pending output
1148          */
1149         CURVNET_SET(ifp->if_vnet);
1150
1151         l2tun = false;
1152         if ((tp->tun_flags & TUN_L2) != 0) {
1153                 l2tun = true;
1154                 IF_DRAIN(&ifp->if_snd);
1155         } else {
1156                 IFQ_PURGE(&ifp->if_snd);
1157         }
1158
1159         /* For vmnet, we won't do most of the address/route bits */
1160         if ((tp->tun_flags & TUN_VMNET) != 0 ||
1161             (l2tun && (ifp->if_flags & IFF_LINK0) != 0))
1162                 goto out;
1163
1164         if (ifp->if_flags & IFF_UP) {
1165                 TUN_UNLOCK(tp);
1166                 if_down(ifp);
1167                 TUN_LOCK(tp);
1168         }
1169
1170         /* Delete all addresses and routes which reference this interface. */
1171         if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
1172                 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1173                 TUN_UNLOCK(tp);
1174                 if_purgeaddrs(ifp);
1175                 TUN_LOCK(tp);
1176         }
1177
1178 out:
1179         if_link_state_change(ifp, LINK_STATE_DOWN);
1180         CURVNET_RESTORE();
1181
1182         funsetown(&tp->tun_sigio);
1183         selwakeuppri(&tp->tun_rsel, PZERO + 1);
1184         KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
1185         TUNDEBUG (ifp, "closed\n");
1186         tp->tun_flags &= ~TUN_OPEN;
1187         tp->tun_pid = 0;
1188         tun_vnethdr_set(ifp, 0);
1189
1190         tun_unbusy_locked(tp);
1191         TUN_UNLOCK(tp);
1192 }
1193
1194 static void
1195 tuninit(struct ifnet *ifp)
1196 {
1197         struct tuntap_softc *tp = ifp->if_softc;
1198
1199         TUNDEBUG(ifp, "tuninit\n");
1200
1201         TUN_LOCK(tp);
1202         ifp->if_drv_flags |= IFF_DRV_RUNNING;
1203         if ((tp->tun_flags & TUN_L2) == 0) {
1204                 ifp->if_flags |= IFF_UP;
1205                 getmicrotime(&ifp->if_lastchange);
1206                 TUN_UNLOCK(tp);
1207         } else {
1208                 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1209                 TUN_UNLOCK(tp);
1210                 /* attempt to start output */
1211                 tunstart_l2(ifp);
1212         }
1213
1214 }
1215
1216 /*
1217  * Used only for l2 tunnel.
1218  */
1219 static void
1220 tunifinit(void *xtp)
1221 {
1222         struct tuntap_softc *tp;
1223
1224         tp = (struct tuntap_softc *)xtp;
1225         tuninit(tp->tun_ifp);
1226 }
1227
1228 /*
1229  * To be called under TUN_LOCK. Update ifp->if_hwassist according to the
1230  * current value of ifp->if_capenable.
1231  */
1232 static void
1233 tun_caps_changed(struct ifnet *ifp)
1234 {
1235         uint64_t hwassist = 0;
1236
1237         TUN_LOCK_ASSERT((struct tuntap_softc *)ifp->if_softc);
1238         if (ifp->if_capenable & IFCAP_TXCSUM)
1239                 hwassist |= CSUM_TCP | CSUM_UDP;
1240         if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
1241                 hwassist |= CSUM_TCP_IPV6
1242                     | CSUM_UDP_IPV6;
1243         if (ifp->if_capenable & IFCAP_TSO4)
1244                 hwassist |= CSUM_IP_TSO;
1245         if (ifp->if_capenable & IFCAP_TSO6)
1246                 hwassist |= CSUM_IP6_TSO;
1247         ifp->if_hwassist = hwassist;
1248 }
1249
1250 /*
1251  * To be called under TUN_LOCK. Update tp->tun_vhdrlen and adjust
1252  * if_capabilities and if_capenable as needed.
1253  */
1254 static void
1255 tun_vnethdr_set(struct ifnet *ifp, int vhdrlen)
1256 {
1257         struct tuntap_softc *tp = ifp->if_softc;
1258
1259         TUN_LOCK_ASSERT(tp);
1260
1261         if (tp->tun_vhdrlen == vhdrlen)
1262                 return;
1263
1264         /*
1265          * Update if_capabilities to reflect the
1266          * functionalities offered by the virtio-net
1267          * header.
1268          */
1269         if (vhdrlen != 0)
1270                 ifp->if_capabilities |=
1271                         TAP_VNET_HDR_CAPS;
1272         else
1273                 ifp->if_capabilities &=
1274                         ~TAP_VNET_HDR_CAPS;
1275         /*
1276          * Disable any capabilities that we don't
1277          * support anymore.
1278          */
1279         ifp->if_capenable &= ifp->if_capabilities;
1280         tun_caps_changed(ifp);
1281         tp->tun_vhdrlen = vhdrlen;
1282
1283         TUNDEBUG(ifp, "vnet_hdr_len=%d, if_capabilities=%x\n",
1284             vhdrlen, ifp->if_capabilities);
1285 }
1286
1287 /*
1288  * Process an ioctl request.
1289  */
1290 static int
1291 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1292 {
1293         struct ifreq *ifr = (struct ifreq *)data;
1294         struct tuntap_softc *tp;
1295         struct ifstat *ifs;
1296         struct ifmediareq       *ifmr;
1297         int             dummy, error = 0;
1298         bool            l2tun;
1299
1300         ifmr = NULL;
1301         sx_xlock(&tun_ioctl_sx);
1302         tp = ifp->if_softc;
1303         if (tp == NULL) {
1304                 error = ENXIO;
1305                 goto bad;
1306         }
1307         l2tun = (tp->tun_flags & TUN_L2) != 0;
1308         switch(cmd) {
1309         case SIOCGIFSTATUS:
1310                 ifs = (struct ifstat *)data;
1311                 TUN_LOCK(tp);
1312                 if (tp->tun_pid)
1313                         snprintf(ifs->ascii, sizeof(ifs->ascii),
1314                             "\tOpened by PID %d\n", tp->tun_pid);
1315                 else
1316                         ifs->ascii[0] = '\0';
1317                 TUN_UNLOCK(tp);
1318                 break;
1319         case SIOCSIFADDR:
1320                 if (l2tun)
1321                         error = ether_ioctl(ifp, cmd, data);
1322                 else
1323                         tuninit(ifp);
1324                 if (error == 0)
1325                     TUNDEBUG(ifp, "address set\n");
1326                 break;
1327         case SIOCSIFMTU:
1328                 ifp->if_mtu = ifr->ifr_mtu;
1329                 TUNDEBUG(ifp, "mtu set\n");
1330                 break;
1331         case SIOCSIFFLAGS:
1332         case SIOCADDMULTI:
1333         case SIOCDELMULTI:
1334                 break;
1335         case SIOCGIFMEDIA:
1336                 if (!l2tun) {
1337                         error = EINVAL;
1338                         break;
1339                 }
1340
1341                 ifmr = (struct ifmediareq *)data;
1342                 dummy = ifmr->ifm_count;
1343                 ifmr->ifm_count = 1;
1344                 ifmr->ifm_status = IFM_AVALID;
1345                 ifmr->ifm_active = IFM_ETHER | IFM_FDX | IFM_1000_T;
1346                 if (tp->tun_flags & TUN_OPEN)
1347                         ifmr->ifm_status |= IFM_ACTIVE;
1348                 ifmr->ifm_current = ifmr->ifm_active;
1349                 if (dummy >= 1) {
1350                         int media = IFM_ETHER;
1351                         error = copyout(&media, ifmr->ifm_ulist, sizeof(int));
1352                 }
1353                 break;
1354         case SIOCSIFCAP:
1355                 TUN_LOCK(tp);
1356                 ifp->if_capenable = ifr->ifr_reqcap;
1357                 tun_caps_changed(ifp);
1358                 TUN_UNLOCK(tp);
1359                 VLAN_CAPABILITIES(ifp);
1360                 break;
1361         default:
1362                 if (l2tun) {
1363                         error = ether_ioctl(ifp, cmd, data);
1364                 } else {
1365                         error = EINVAL;
1366                 }
1367         }
1368 bad:
1369         sx_xunlock(&tun_ioctl_sx);
1370         return (error);
1371 }
1372
1373 /*
1374  * tunoutput - queue packets from higher level ready to put out.
1375  */
1376 static int
1377 tunoutput(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
1378     struct route *ro)
1379 {
1380         struct tuntap_softc *tp = ifp->if_softc;
1381         u_short cached_tun_flags;
1382         int error;
1383         u_int32_t af;
1384
1385         TUNDEBUG (ifp, "tunoutput\n");
1386
1387 #ifdef MAC
1388         error = mac_ifnet_check_transmit(ifp, m0);
1389         if (error) {
1390                 m_freem(m0);
1391                 return (error);
1392         }
1393 #endif
1394
1395         /* Could be unlocked read? */
1396         TUN_LOCK(tp);
1397         cached_tun_flags = tp->tun_flags;
1398         TUN_UNLOCK(tp);
1399         if ((cached_tun_flags & TUN_READY) != TUN_READY) {
1400                 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
1401                 m_freem (m0);
1402                 return (EHOSTDOWN);
1403         }
1404
1405         if ((ifp->if_flags & IFF_UP) != IFF_UP) {
1406                 m_freem (m0);
1407                 return (EHOSTDOWN);
1408         }
1409
1410         /* BPF writes need to be handled specially. */
1411         if (dst->sa_family == AF_UNSPEC)
1412                 bcopy(dst->sa_data, &af, sizeof(af));
1413         else
1414                 af = RO_GET_FAMILY(ro, dst);
1415
1416         if (bpf_peers_present(ifp->if_bpf))
1417                 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m0);
1418
1419         /* prepend sockaddr? this may abort if the mbuf allocation fails */
1420         if (cached_tun_flags & TUN_LMODE) {
1421                 /* allocate space for sockaddr */
1422                 M_PREPEND(m0, dst->sa_len, M_NOWAIT);
1423
1424                 /* if allocation failed drop packet */
1425                 if (m0 == NULL) {
1426                         if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1427                         if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1428                         return (ENOBUFS);
1429                 } else {
1430                         bcopy(dst, m0->m_data, dst->sa_len);
1431                 }
1432         }
1433
1434         if (cached_tun_flags & TUN_IFHEAD) {
1435                 /* Prepend the address family */
1436                 M_PREPEND(m0, 4, M_NOWAIT);
1437
1438                 /* if allocation failed drop packet */
1439                 if (m0 == NULL) {
1440                         if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1441                         if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1442                         return (ENOBUFS);
1443                 } else
1444                         *(u_int32_t *)m0->m_data = htonl(af);
1445         } else {
1446 #ifdef INET
1447                 if (af != AF_INET)
1448 #endif
1449                 {
1450                         m_freem(m0);
1451                         return (EAFNOSUPPORT);
1452                 }
1453         }
1454
1455         error = (ifp->if_transmit)(ifp, m0);
1456         if (error)
1457                 return (ENOBUFS);
1458         if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
1459         return (0);
1460 }
1461
1462 /*
1463  * the cdevsw interface is now pretty minimal.
1464  */
1465 static  int
1466 tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag,
1467     struct thread *td)
1468 {
1469         struct ifreq ifr, *ifrp;
1470         struct tuntap_softc *tp = dev->si_drv1;
1471         struct ifnet *ifp = TUN2IFP(tp);
1472         struct tuninfo *tunp;
1473         int error, iflags, ival;
1474         bool    l2tun;
1475
1476         l2tun = (tp->tun_flags & TUN_L2) != 0;
1477         if (l2tun) {
1478                 /* tap specific ioctls */
1479                 switch(cmd) {
1480                 /* VMware/VMnet port ioctl's */
1481 #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
1482     defined(COMPAT_FREEBSD4)
1483                 case _IO('V', 0):
1484                         ival = IOCPARM_IVAL(data);
1485                         data = (caddr_t)&ival;
1486                         /* FALLTHROUGH */
1487 #endif
1488                 case VMIO_SIOCSIFFLAGS: /* VMware/VMnet SIOCSIFFLAGS */
1489                         iflags = *(int *)data;
1490                         iflags &= TUN_VMIO_FLAG_MASK;
1491                         iflags &= ~IFF_CANTCHANGE;
1492                         iflags |= IFF_UP;
1493
1494                         TUN_LOCK(tp);
1495                         ifp->if_flags = iflags |
1496                             (ifp->if_flags & IFF_CANTCHANGE);
1497                         TUN_UNLOCK(tp);
1498
1499                         return (0);
1500                 case SIOCGIFADDR:       /* get MAC address of the remote side */
1501                         TUN_LOCK(tp);
1502                         bcopy(&tp->tun_ether.octet, data,
1503                             sizeof(tp->tun_ether.octet));
1504                         TUN_UNLOCK(tp);
1505
1506                         return (0);
1507                 case SIOCSIFADDR:       /* set MAC address of the remote side */
1508                         TUN_LOCK(tp);
1509                         bcopy(data, &tp->tun_ether.octet,
1510                             sizeof(tp->tun_ether.octet));
1511                         TUN_UNLOCK(tp);
1512
1513                         return (0);
1514                 case TAPSVNETHDR:
1515                         ival = *(int *)data;
1516                         if (ival != 0 &&
1517                             ival != sizeof(struct virtio_net_hdr) &&
1518                             ival != sizeof(struct virtio_net_hdr_mrg_rxbuf)) {
1519                                 return (EINVAL);
1520                         }
1521                         TUN_LOCK(tp);
1522                         tun_vnethdr_set(ifp, ival);
1523                         TUN_UNLOCK(tp);
1524
1525                         return (0);
1526                 case TAPGVNETHDR:
1527                         TUN_LOCK(tp);
1528                         *(int *)data = tp->tun_vhdrlen;
1529                         TUN_UNLOCK(tp);
1530
1531                         return (0);
1532                 }
1533
1534                 /* Fall through to the common ioctls if unhandled */
1535         } else {
1536                 switch (cmd) {
1537                 case TUNSLMODE:
1538                         TUN_LOCK(tp);
1539                         if (*(int *)data) {
1540                                 tp->tun_flags |= TUN_LMODE;
1541                                 tp->tun_flags &= ~TUN_IFHEAD;
1542                         } else
1543                                 tp->tun_flags &= ~TUN_LMODE;
1544                         TUN_UNLOCK(tp);
1545
1546                         return (0);
1547                 case TUNSIFHEAD:
1548                         TUN_LOCK(tp);
1549                         if (*(int *)data) {
1550                                 tp->tun_flags |= TUN_IFHEAD;
1551                                 tp->tun_flags &= ~TUN_LMODE;
1552                         } else
1553                                 tp->tun_flags &= ~TUN_IFHEAD;
1554                         TUN_UNLOCK(tp);
1555
1556                         return (0);
1557                 case TUNGIFHEAD:
1558                         TUN_LOCK(tp);
1559                         *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
1560                         TUN_UNLOCK(tp);
1561
1562                         return (0);
1563                 case TUNSIFMODE:
1564                         /* deny this if UP */
1565                         if (TUN2IFP(tp)->if_flags & IFF_UP)
1566                                 return (EBUSY);
1567
1568                         switch (*(int *)data & ~IFF_MULTICAST) {
1569                         case IFF_POINTOPOINT:
1570                         case IFF_BROADCAST:
1571                                 TUN_LOCK(tp);
1572                                 TUN2IFP(tp)->if_flags &=
1573                                     ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
1574                                 TUN2IFP(tp)->if_flags |= *(int *)data;
1575                                 TUN_UNLOCK(tp);
1576
1577                                 break;
1578                         default:
1579                                 return (EINVAL);
1580                         }
1581
1582                         return (0);
1583                 case TUNSIFPID:
1584                         TUN_LOCK(tp);
1585                         tp->tun_pid = curthread->td_proc->p_pid;
1586                         TUN_UNLOCK(tp);
1587
1588                         return (0);
1589                 }
1590                 /* Fall through to the common ioctls if unhandled */
1591         }
1592
1593         switch (cmd) {
1594         case TUNGIFNAME:
1595                 ifrp = (struct ifreq *)data;
1596                 strlcpy(ifrp->ifr_name, TUN2IFP(tp)->if_xname, IFNAMSIZ);
1597
1598                 return (0);
1599         case TUNSIFINFO:
1600                 tunp = (struct tuninfo *)data;
1601                 if (TUN2IFP(tp)->if_type != tunp->type)
1602                         return (EPROTOTYPE);
1603                 TUN_LOCK(tp);
1604                 if (TUN2IFP(tp)->if_mtu != tunp->mtu) {
1605                         strlcpy(ifr.ifr_name, if_name(TUN2IFP(tp)), IFNAMSIZ);
1606                         ifr.ifr_mtu = tunp->mtu;
1607                         CURVNET_SET(TUN2IFP(tp)->if_vnet);
1608                         error = ifhwioctl(SIOCSIFMTU, TUN2IFP(tp),
1609                             (caddr_t)&ifr, td);
1610                         CURVNET_RESTORE();
1611                         if (error) {
1612                                 TUN_UNLOCK(tp);
1613                                 return (error);
1614                         }
1615                 }
1616                 TUN2IFP(tp)->if_baudrate = tunp->baudrate;
1617                 TUN_UNLOCK(tp);
1618                 break;
1619         case TUNGIFINFO:
1620                 tunp = (struct tuninfo *)data;
1621                 TUN_LOCK(tp);
1622                 tunp->mtu = TUN2IFP(tp)->if_mtu;
1623                 tunp->type = TUN2IFP(tp)->if_type;
1624                 tunp->baudrate = TUN2IFP(tp)->if_baudrate;
1625                 TUN_UNLOCK(tp);
1626                 break;
1627         case TUNSDEBUG:
1628                 tundebug = *(int *)data;
1629                 break;
1630         case TUNGDEBUG:
1631                 *(int *)data = tundebug;
1632                 break;
1633         case FIONBIO:
1634                 break;
1635         case FIOASYNC:
1636                 TUN_LOCK(tp);
1637                 if (*(int *)data)
1638                         tp->tun_flags |= TUN_ASYNC;
1639                 else
1640                         tp->tun_flags &= ~TUN_ASYNC;
1641                 TUN_UNLOCK(tp);
1642                 break;
1643         case FIONREAD:
1644                 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) {
1645                         struct mbuf *mb;
1646                         IFQ_LOCK(&TUN2IFP(tp)->if_snd);
1647                         IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb);
1648                         for (*(int *)data = 0; mb != NULL; mb = mb->m_next)
1649                                 *(int *)data += mb->m_len;
1650                         IFQ_UNLOCK(&TUN2IFP(tp)->if_snd);
1651                 } else
1652                         *(int *)data = 0;
1653                 break;
1654         case FIOSETOWN:
1655                 return (fsetown(*(int *)data, &tp->tun_sigio));
1656
1657         case FIOGETOWN:
1658                 *(int *)data = fgetown(&tp->tun_sigio);
1659                 return (0);
1660
1661         /* This is deprecated, FIOSETOWN should be used instead. */
1662         case TIOCSPGRP:
1663                 return (fsetown(-(*(int *)data), &tp->tun_sigio));
1664
1665         /* This is deprecated, FIOGETOWN should be used instead. */
1666         case TIOCGPGRP:
1667                 *(int *)data = -fgetown(&tp->tun_sigio);
1668                 return (0);
1669
1670         default:
1671                 return (ENOTTY);
1672         }
1673         return (0);
1674 }
1675
1676 /*
1677  * The cdevsw read interface - reads a packet at a time, or at
1678  * least as much of a packet as can be read.
1679  */
1680 static  int
1681 tunread(struct cdev *dev, struct uio *uio, int flag)
1682 {
1683         struct tuntap_softc *tp = dev->si_drv1;
1684         struct ifnet    *ifp = TUN2IFP(tp);
1685         struct mbuf     *m;
1686         size_t          len;
1687         int             error = 0;
1688
1689         TUNDEBUG (ifp, "read\n");
1690         TUN_LOCK(tp);
1691         if ((tp->tun_flags & TUN_READY) != TUN_READY) {
1692                 TUN_UNLOCK(tp);
1693                 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
1694                 return (EHOSTDOWN);
1695         }
1696
1697         tp->tun_flags &= ~TUN_RWAIT;
1698
1699         for (;;) {
1700                 IFQ_DEQUEUE(&ifp->if_snd, m);
1701                 if (m != NULL)
1702                         break;
1703                 if (flag & O_NONBLOCK) {
1704                         TUN_UNLOCK(tp);
1705                         return (EWOULDBLOCK);
1706                 }
1707                 tp->tun_flags |= TUN_RWAIT;
1708                 error = mtx_sleep(tp, &tp->tun_mtx, PCATCH | (PZERO + 1),
1709                     "tunread", 0);
1710                 if (error != 0) {
1711                         TUN_UNLOCK(tp);
1712                         return (error);
1713                 }
1714         }
1715         TUN_UNLOCK(tp);
1716
1717         if ((tp->tun_flags & TUN_L2) != 0)
1718                 BPF_MTAP(ifp, m);
1719
1720         len = min(tp->tun_vhdrlen, uio->uio_resid);
1721         if (len > 0) {
1722                 struct virtio_net_hdr_mrg_rxbuf vhdr;
1723
1724                 bzero(&vhdr, sizeof(vhdr));
1725                 if (m->m_pkthdr.csum_flags & TAP_ALL_OFFLOAD) {
1726                         m = virtio_net_tx_offload(ifp, m, false, &vhdr.hdr);
1727                 }
1728
1729                 TUNDEBUG(ifp, "txvhdr: f %u, gt %u, hl %u, "
1730                     "gs %u, cs %u, co %u\n", vhdr.hdr.flags,
1731                     vhdr.hdr.gso_type, vhdr.hdr.hdr_len,
1732                     vhdr.hdr.gso_size, vhdr.hdr.csum_start,
1733                     vhdr.hdr.csum_offset);
1734                 error = uiomove(&vhdr, len, uio);
1735         }
1736
1737         while (m && uio->uio_resid > 0 && error == 0) {
1738                 len = min(uio->uio_resid, m->m_len);
1739                 if (len != 0)
1740                         error = uiomove(mtod(m, void *), len, uio);
1741                 m = m_free(m);
1742         }
1743
1744         if (m) {
1745                 TUNDEBUG(ifp, "Dropping mbuf\n");
1746                 m_freem(m);
1747         }
1748         return (error);
1749 }
1750
1751 static int
1752 tunwrite_l2(struct tuntap_softc *tp, struct mbuf *m,
1753             struct virtio_net_hdr_mrg_rxbuf *vhdr)
1754 {
1755         struct epoch_tracker et;
1756         struct ether_header *eh;
1757         struct ifnet *ifp;
1758
1759         ifp = TUN2IFP(tp);
1760
1761         /*
1762          * Only pass a unicast frame to ether_input(), if it would
1763          * actually have been received by non-virtual hardware.
1764          */
1765         if (m->m_len < sizeof(struct ether_header)) {
1766                 m_freem(m);
1767                 return (0);
1768         }
1769
1770         eh = mtod(m, struct ether_header *);
1771
1772         if (eh && (ifp->if_flags & IFF_PROMISC) == 0 &&
1773             !ETHER_IS_MULTICAST(eh->ether_dhost) &&
1774             bcmp(eh->ether_dhost, IF_LLADDR(ifp), ETHER_ADDR_LEN) != 0) {
1775                 m_freem(m);
1776                 return (0);
1777         }
1778
1779         if (vhdr != NULL && virtio_net_rx_csum(m, &vhdr->hdr)) {
1780                 m_freem(m);
1781                 return (0);
1782         }
1783
1784         /* Pass packet up to parent. */
1785         CURVNET_SET(ifp->if_vnet);
1786         NET_EPOCH_ENTER(et);
1787         (*ifp->if_input)(ifp, m);
1788         NET_EPOCH_EXIT(et);
1789         CURVNET_RESTORE();
1790         /* ibytes are counted in parent */
1791         if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1792         return (0);
1793 }
1794
1795 static int
1796 tunwrite_l3(struct tuntap_softc *tp, struct mbuf *m)
1797 {
1798         struct epoch_tracker et;
1799         struct ifnet *ifp;
1800         int family, isr;
1801
1802         ifp = TUN2IFP(tp);
1803         /* Could be unlocked read? */
1804         TUN_LOCK(tp);
1805         if (tp->tun_flags & TUN_IFHEAD) {
1806                 TUN_UNLOCK(tp);
1807                 if (m->m_len < sizeof(family) &&
1808                 (m = m_pullup(m, sizeof(family))) == NULL)
1809                         return (ENOBUFS);
1810                 family = ntohl(*mtod(m, u_int32_t *));
1811                 m_adj(m, sizeof(family));
1812         } else {
1813                 TUN_UNLOCK(tp);
1814                 family = AF_INET;
1815         }
1816
1817         BPF_MTAP2(ifp, &family, sizeof(family), m);
1818
1819         switch (family) {
1820 #ifdef INET
1821         case AF_INET:
1822                 isr = NETISR_IP;
1823                 break;
1824 #endif
1825 #ifdef INET6
1826         case AF_INET6:
1827                 isr = NETISR_IPV6;
1828                 break;
1829 #endif
1830         default:
1831                 m_freem(m);
1832                 return (EAFNOSUPPORT);
1833         }
1834         random_harvest_queue(m, sizeof(*m), RANDOM_NET_TUN);
1835         if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
1836         if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1837         CURVNET_SET(ifp->if_vnet);
1838         M_SETFIB(m, ifp->if_fib);
1839         NET_EPOCH_ENTER(et);
1840         netisr_dispatch(isr, m);
1841         NET_EPOCH_EXIT(et);
1842         CURVNET_RESTORE();
1843         return (0);
1844 }
1845
1846 /*
1847  * the cdevsw write interface - an atomic write is a packet - or else!
1848  */
1849 static  int
1850 tunwrite(struct cdev *dev, struct uio *uio, int flag)
1851 {
1852         struct virtio_net_hdr_mrg_rxbuf vhdr;
1853         struct tuntap_softc *tp;
1854         struct ifnet    *ifp;
1855         struct mbuf     *m;
1856         uint32_t        mru;
1857         int             align, vhdrlen, error;
1858         bool            l2tun;
1859
1860         tp = dev->si_drv1;
1861         ifp = TUN2IFP(tp);
1862         TUNDEBUG(ifp, "tunwrite\n");
1863         if ((ifp->if_flags & IFF_UP) != IFF_UP)
1864                 /* ignore silently */
1865                 return (0);
1866
1867         if (uio->uio_resid == 0)
1868                 return (0);
1869
1870         l2tun = (tp->tun_flags & TUN_L2) != 0;
1871         mru = l2tun ? TAPMRU : TUNMRU;
1872         vhdrlen = tp->tun_vhdrlen;
1873         align = 0;
1874         if (l2tun) {
1875                 align = ETHER_ALIGN;
1876                 mru += vhdrlen;
1877         } else if ((tp->tun_flags & TUN_IFHEAD) != 0)
1878                 mru += sizeof(uint32_t);        /* family */
1879         if (uio->uio_resid < 0 || uio->uio_resid > mru) {
1880                 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid);
1881                 return (EIO);
1882         }
1883
1884         if (vhdrlen > 0) {
1885                 error = uiomove(&vhdr, vhdrlen, uio);
1886                 if (error != 0)
1887                         return (error);
1888                 TUNDEBUG(ifp, "txvhdr: f %u, gt %u, hl %u, "
1889                     "gs %u, cs %u, co %u\n", vhdr.hdr.flags,
1890                     vhdr.hdr.gso_type, vhdr.hdr.hdr_len,
1891                     vhdr.hdr.gso_size, vhdr.hdr.csum_start,
1892                     vhdr.hdr.csum_offset);
1893         }
1894
1895         if ((m = m_uiotombuf(uio, M_NOWAIT, 0, align, M_PKTHDR)) == NULL) {
1896                 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
1897                 return (ENOBUFS);
1898         }
1899
1900         m->m_pkthdr.rcvif = ifp;
1901 #ifdef MAC
1902         mac_ifnet_create_mbuf(ifp, m);
1903 #endif
1904
1905         if (l2tun)
1906                 return (tunwrite_l2(tp, m, vhdrlen > 0 ? &vhdr : NULL));
1907
1908         return (tunwrite_l3(tp, m));
1909 }
1910
1911 /*
1912  * tunpoll - the poll interface, this is only useful on reads
1913  * really. The write detect always returns true, write never blocks
1914  * anyway, it either accepts the packet or drops it.
1915  */
1916 static  int
1917 tunpoll(struct cdev *dev, int events, struct thread *td)
1918 {
1919         struct tuntap_softc *tp = dev->si_drv1;
1920         struct ifnet    *ifp = TUN2IFP(tp);
1921         int             revents = 0;
1922
1923         TUNDEBUG(ifp, "tunpoll\n");
1924
1925         if (events & (POLLIN | POLLRDNORM)) {
1926                 IFQ_LOCK(&ifp->if_snd);
1927                 if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
1928                         TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len);
1929                         revents |= events & (POLLIN | POLLRDNORM);
1930                 } else {
1931                         TUNDEBUG(ifp, "tunpoll waiting\n");
1932                         selrecord(td, &tp->tun_rsel);
1933                 }
1934                 IFQ_UNLOCK(&ifp->if_snd);
1935         }
1936         revents |= events & (POLLOUT | POLLWRNORM);
1937
1938         return (revents);
1939 }
1940
1941 /*
1942  * tunkqfilter - support for the kevent() system call.
1943  */
1944 static int
1945 tunkqfilter(struct cdev *dev, struct knote *kn)
1946 {
1947         struct tuntap_softc     *tp = dev->si_drv1;
1948         struct ifnet    *ifp = TUN2IFP(tp);
1949
1950         switch(kn->kn_filter) {
1951         case EVFILT_READ:
1952                 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n",
1953                     ifp->if_xname, dev2unit(dev));
1954                 kn->kn_fop = &tun_read_filterops;
1955                 break;
1956
1957         case EVFILT_WRITE:
1958                 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n",
1959                     ifp->if_xname, dev2unit(dev));
1960                 kn->kn_fop = &tun_write_filterops;
1961                 break;
1962
1963         default:
1964                 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n",
1965                     ifp->if_xname, dev2unit(dev));
1966                 return(EINVAL);
1967         }
1968
1969         kn->kn_hook = tp;
1970         knlist_add(&tp->tun_rsel.si_note, kn, 0);
1971
1972         return (0);
1973 }
1974
1975 /*
1976  * Return true of there is data in the interface queue.
1977  */
1978 static int
1979 tunkqread(struct knote *kn, long hint)
1980 {
1981         int                     ret;
1982         struct tuntap_softc     *tp = kn->kn_hook;
1983         struct cdev             *dev = tp->tun_dev;
1984         struct ifnet    *ifp = TUN2IFP(tp);
1985
1986         if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) {
1987                 TUNDEBUG(ifp,
1988                     "%s have data in the queue.  Len = %d, minor = %#x\n",
1989                     ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev));
1990                 ret = 1;
1991         } else {
1992                 TUNDEBUG(ifp,
1993                     "%s waiting for data, minor = %#x\n", ifp->if_xname,
1994                     dev2unit(dev));
1995                 ret = 0;
1996         }
1997
1998         return (ret);
1999 }
2000
2001 /*
2002  * Always can write, always return MTU in kn->data.
2003  */
2004 static int
2005 tunkqwrite(struct knote *kn, long hint)
2006 {
2007         struct tuntap_softc     *tp = kn->kn_hook;
2008         struct ifnet    *ifp = TUN2IFP(tp);
2009
2010         kn->kn_data = ifp->if_mtu;
2011
2012         return (1);
2013 }
2014
2015 static void
2016 tunkqdetach(struct knote *kn)
2017 {
2018         struct tuntap_softc     *tp = kn->kn_hook;
2019
2020         knlist_remove(&tp->tun_rsel.si_note, kn, 0);
2021 }