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