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
 332 struct tuntap_driver_cloner {
 333         SLIST_ENTRY(tuntap_driver_cloner)        link;
 334         struct tuntap_driver                    *drv;
 335         struct if_clone                         *cloner;
 336 };
 337
 338 VNET_DEFINE_STATIC(SLIST_HEAD(, tuntap_driver_cloner), tuntap_driver_cloners) =
 339     SLIST_HEAD_INITIALIZER(tuntap_driver_cloners);
 340
 341 #define V_tuntap_driver_cloners VNET(tuntap_driver_cloners)
 342
 343 /*
 344  * Mechanism for marking a tunnel device as busy so that we can safely do some
 345  * orthogonal operations (such as operations on devices) without racing against
 346  * tun_destroy.  tun_destroy will wait on the condvar if we're at all busy or
 347  * open, to be woken up when the condition is alleviated.
 348  */
 349 static int
 350 tun_busy_locked(struct tuntap_softc *tp)
 351 {
 352
 353         TUN_LOCK_ASSERT(tp);
 354         if ((tp->tun_flags & TUN_DYING) != 0) {
 355                 /*
 356                  * Perhaps unintuitive, but the device is busy going away.
 357                  * Other interpretations of EBUSY from tun_busy make little
 358                  * sense, since making a busy device even more busy doesn't
 359                  * sound like a problem.
 360                  */
 361                 return (EBUSY);
 362         }
 363
 364         ++tp->tun_busy;
 365         return (0);
 366 }
 367
 368 static void
 369 tun_unbusy_locked(struct tuntap_softc *tp)
 370 {
 371
 372         TUN_LOCK_ASSERT(tp);
 373         KASSERT(tp->tun_busy != 0, ("tun_unbusy: called for non-busy tunnel"));
 374
 375         --tp->tun_busy;
 376         /* Wake up anything that may be waiting on our busy tunnel. */
 377         if (tp->tun_busy == 0)
 378                 cv_broadcast(&tp->tun_cv);
 379 }
 380
 381 static int
 382 tun_busy(struct tuntap_softc *tp)
 383 {
 384         int ret;
 385
 386         TUN_LOCK(tp);
 387         ret = tun_busy_locked(tp);
 388         TUN_UNLOCK(tp);
 389         return (ret);
 390 }
 391
 392 static void
 393 tun_unbusy(struct tuntap_softc *tp)
 394 {
 395
 396         TUN_LOCK(tp);
 397         tun_unbusy_locked(tp);
 398         TUN_UNLOCK(tp);
 399 }
 400
 401 /*
 402  * Sets unit and/or flags given the device name.  Must be called with correct
 403  * vnet context.
 404  */
 405 static int
 406 tuntap_name2info(const char *name, int *outunit, int *outflags)
 407 {
 408         struct tuntap_driver *drv;
 409         struct tuntap_driver_cloner *drvc;
 410         char *dname;
 411         int flags, unit;
 412         bool found;
 413
 414         if (name == NULL)
 415                 return (EINVAL);
 416
 417         /*
 418          * Needed for dev_stdclone, but dev_stdclone will not modify, it just
 419          * wants to be able to pass back a char * through the second param. We
 420          * will always set that as NULL here, so we'll fake it.
 421          */
 422         dname = __DECONST(char *, name);
 423         found = false;
 424
 425         KASSERT(!SLIST_EMPTY(&V_tuntap_driver_cloners),
 426             ("tuntap_driver_cloners failed to initialize"));
 427         SLIST_FOREACH(drvc, &V_tuntap_driver_cloners, link) {
 428                 KASSERT(drvc->drv != NULL,
 429                     ("tuntap_driver_cloners entry not properly initialized"));
 430                 drv = drvc->drv;
 431
 432                 if (strcmp(name, drv->cdevsw.d_name) == 0) {
 433                         found = true;
 434                         unit = -1;
 435                         flags = drv->ident_flags;
 436                         break;
 437                 }
 438
 439                 if (dev_stdclone(dname, NULL, drv->cdevsw.d_name, &unit) == 1) {
 440                         found = true;
 441                         flags = drv->ident_flags;
 442                         break;
 443                 }
 444         }
 445
 446         if (!found)
 447                 return (ENXIO);
 448
 449         if (outunit != NULL)
 450                 *outunit = unit;
 451         if (outflags != NULL)
 452                 *outflags = flags;
 453         return (0);
 454 }
 455
 456 /*
 457  * Get driver information from a set of flags specified.  Masks the identifying
 458  * part of the flags and compares it against all of the available
 459  * tuntap_drivers. Must be called with correct vnet context.
 460  */
 461 static struct tuntap_driver *
 462 tuntap_driver_from_flags(int tun_flags)
 463 {
 464         struct tuntap_driver *drv;
 465         struct tuntap_driver_cloner *drvc;
 466
 467         KASSERT(!SLIST_EMPTY(&V_tuntap_driver_cloners),
 468             ("tuntap_driver_cloners failed to initialize"));
 469         SLIST_FOREACH(drvc, &V_tuntap_driver_cloners, link) {
 470                 KASSERT(drvc->drv != NULL,
 471                     ("tuntap_driver_cloners entry not properly initialized"));
 472                 drv = drvc->drv;
 473                 if ((tun_flags & TUN_DRIVER_IDENT_MASK) == drv->ident_flags)
 474                         return (drv);
 475         }
 476
 477         return (NULL);
 478 }
 479
 480 static int
 481 tun_clone_match(struct if_clone *ifc, const char *name)
 482 {
 483         int tunflags;
 484
 485         if (tuntap_name2info(name, NULL, &tunflags) == 0) {
 486                 if ((tunflags & TUN_L2) == 0)
 487                         return (1);
 488         }
 489
 490         return (0);
 491 }
 492
 493 static int
 494 tap_clone_match(struct if_clone *ifc, const char *name)
 495 {
 496         int tunflags;
 497
 498         if (tuntap_name2info(name, NULL, &tunflags) == 0) {
 499                 if ((tunflags & (TUN_L2 | TUN_VMNET)) == TUN_L2)
 500                         return (1);
 501         }
 502
 503         return (0);
 504 }
 505
 506 static int
 507 vmnet_clone_match(struct if_clone *ifc, const char *name)
 508 {
 509         int tunflags;
 510
 511         if (tuntap_name2info(name, NULL, &tunflags) == 0) {
 512                 if ((tunflags & TUN_VMNET) != 0)
 513                         return (1);
 514         }
 515
 516         return (0);
 517 }
 518
 519 static int
 520 tun_clone_create(struct if_clone *ifc, char *name, size_t len,
 521     struct ifc_data *ifd, struct ifnet **ifpp)
 522 {
 523         struct tuntap_driver *drv;
 524         struct cdev *dev;
 525         int err, i, tunflags, unit;
 526
 527         tunflags = 0;
 528         /* The name here tells us exactly what we're creating */
 529         err = tuntap_name2info(name, &unit, &tunflags);
 530         if (err != 0)
 531                 return (err);
 532
 533         drv = tuntap_driver_from_flags(tunflags);
 534         if (drv == NULL)
 535                 return (ENXIO);
 536
 537         if (unit != -1) {
 538                 /* If this unit number is still available that's okay. */
 539                 if (alloc_unr_specific(drv->unrhdr, unit) == -1)
 540                         return (EEXIST);
 541         } else {
 542                 unit = alloc_unr(drv->unrhdr);
 543         }
 544
 545         snprintf(name, IFNAMSIZ, "%s%d", drv->cdevsw.d_name, unit);
 546
 547         /* find any existing device, or allocate new unit number */
 548         dev = NULL;
 549         i = clone_create(&drv->clones, &drv->cdevsw, &unit, &dev, 0);
 550         /* No preexisting struct cdev *, create one */
 551         if (i != 0)
 552                 i = tun_create_device(drv, unit, NULL, &dev, name);
 553         if (i == 0) {
 554                 dev_ref(dev);
 555                 tuncreate(dev);
 556                 struct tuntap_softc *tp = dev->si_drv1;
 557                 *ifpp = tp->tun_ifp;
 558         }
 559
 560         return (i);
 561 }
 562
 563 static void
 564 tunclone(void *arg, struct ucred *cred, char *name, int namelen,
 565     struct cdev **dev)
 566 {
 567         char devname[SPECNAMELEN + 1];
 568         struct tuntap_driver *drv;
 569         int append_unit, i, u, tunflags;
 570         bool mayclone;
 571
 572         if (*dev != NULL)
 573                 return;
 574
 575         tunflags = 0;
 576         CURVNET_SET(CRED_TO_VNET(cred));
 577         if (tuntap_name2info(name, &u, &tunflags) != 0)
 578                 goto out;       /* Not recognized */
 579
 580         if (u != -1 && u > IF_MAXUNIT)
 581                 goto out;       /* Unit number too high */
 582
 583         mayclone = priv_check_cred(cred, PRIV_NET_IFCREATE) == 0;
 584         if ((tunflags & TUN_L2) != 0) {
 585                 /* tap/vmnet allow user open with a sysctl */
 586                 mayclone = (mayclone || tap_allow_uopen) && tapdclone;
 587         } else {
 588                 mayclone = mayclone && tundclone;
 589         }
 590
 591         /*
 592          * If tun cloning is enabled, only the superuser can create an
 593          * interface.
 594          */
 595         if (!mayclone)
 596                 goto out;
 597
 598         if (u == -1)
 599                 append_unit = 1;
 600         else
 601                 append_unit = 0;
 602
 603         drv = tuntap_driver_from_flags(tunflags);
 604         if (drv == NULL)
 605                 goto out;
 606
 607         /* find any existing device, or allocate new unit number */
 608         i = clone_create(&drv->clones, &drv->cdevsw, &u, dev, 0);
 609         if (i) {
 610                 if (append_unit) {
 611                         namelen = snprintf(devname, sizeof(devname), "%s%d",
 612                             name, u);
 613                         name = devname;
 614                 }
 615
 616                 i = tun_create_device(drv, u, cred, dev, name);
 617         }
 618         if (i == 0) {
 619                 dev_ref(*dev);
 620                 if_clone_create(name, namelen, NULL);
 621         }
 622 out:
 623         CURVNET_RESTORE();
 624 }
 625
 626 static void
 627 tun_destroy(struct tuntap_softc *tp)
 628 {
 629
 630         TUN_LOCK(tp);
 631         tp->tun_flags |= TUN_DYING;
 632         if (tp->tun_busy != 0)
 633                 cv_wait_unlock(&tp->tun_cv, &tp->tun_mtx);
 634         else
 635                 TUN_UNLOCK(tp);
 636
 637         CURVNET_SET(TUN2IFP(tp)->if_vnet);
 638
 639         /* destroy_dev will take care of any alias. */
 640         destroy_dev(tp->tun_dev);
 641         seldrain(&tp->tun_rsel);
 642         knlist_clear(&tp->tun_rsel.si_note, 0);
 643         knlist_destroy(&tp->tun_rsel.si_note);
 644         if ((tp->tun_flags & TUN_L2) != 0) {
 645                 ether_ifdetach(TUN2IFP(tp));
 646         } else {
 647                 bpfdetach(TUN2IFP(tp));
 648                 if_detach(TUN2IFP(tp));
 649         }
 650         sx_xlock(&tun_ioctl_sx);
 651         TUN2IFP(tp)->if_softc = NULL;
 652         sx_xunlock(&tun_ioctl_sx);
 653         free_unr(tp->tun_drv->unrhdr, TUN2IFP(tp)->if_dunit);
 654         if_free(TUN2IFP(tp));
 655         mtx_destroy(&tp->tun_mtx);
 656         cv_destroy(&tp->tun_cv);
 657         free(tp, M_TUN);
 658         CURVNET_RESTORE();
 659 }
 660
 661 static int
 662 tun_clone_destroy(struct if_clone *ifc __unused, struct ifnet *ifp, uint32_t flags)
 663 {
 664         struct tuntap_softc *tp = ifp->if_softc;
 665
 666         mtx_lock(&tunmtx);
 667         TAILQ_REMOVE(&tunhead, tp, tun_list);
 668         mtx_unlock(&tunmtx);
 669         tun_destroy(tp);
 670
 671         return (0);
 672 }
 673
 674 static void
 675 vnet_tun_init(const void *unused __unused)
 676 {
 677         struct tuntap_driver *drv;
 678         struct tuntap_driver_cloner *drvc;
 679         int i;
 680
 681         for (i = 0; i < nitems(tuntap_drivers); ++i) {
 682                 drv = &tuntap_drivers[i];
 683                 drvc = malloc(sizeof(*drvc), M_TUN, M_WAITOK | M_ZERO);
 684
 685                 drvc->drv = drv;
 686                 struct if_clone_addreq req = {
 687                         .match_f = drv->clone_match_fn,
 688                         .create_f = drv->clone_create_fn,
 689                         .destroy_f = drv->clone_destroy_fn,
 690                 };
 691                 drvc->cloner = ifc_attach_cloner(drv->cdevsw.d_name, &req);
 692                 SLIST_INSERT_HEAD(&V_tuntap_driver_cloners, drvc, link);
 693         };
 694 }
 695 VNET_SYSINIT(vnet_tun_init, SI_SUB_PROTO_IF, SI_ORDER_ANY,
 696                 vnet_tun_init, NULL);
 697
 698 static void
 699 vnet_tun_uninit(const void *unused __unused)
 700 {
 701         struct tuntap_driver_cloner *drvc;
 702
 703         while (!SLIST_EMPTY(&V_tuntap_driver_cloners)) {
 704                 drvc = SLIST_FIRST(&V_tuntap_driver_cloners);
 705                 SLIST_REMOVE_HEAD(&V_tuntap_driver_cloners, link);
 706
 707                 if_clone_detach(drvc->cloner);
 708                 free(drvc, M_TUN);
 709         }
 710 }
 711 VNET_SYSUNINIT(vnet_tun_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY,
 712     vnet_tun_uninit, NULL);
 713
 714 static void
 715 tun_uninit(const void *unused __unused)
 716 {
 717         struct tuntap_driver *drv;
 718         struct tuntap_softc *tp;
 719         int i;
 720
 721         EVENTHANDLER_DEREGISTER(ifnet_arrival_event, arrival_tag);
 722         EVENTHANDLER_DEREGISTER(dev_clone, clone_tag);
 723
 724         mtx_lock(&tunmtx);
 725         while ((tp = TAILQ_FIRST(&tunhead)) != NULL) {
 726                 TAILQ_REMOVE(&tunhead, tp, tun_list);
 727                 mtx_unlock(&tunmtx);
 728                 tun_destroy(tp);
 729                 mtx_lock(&tunmtx);
 730         }
 731         mtx_unlock(&tunmtx);
 732         for (i = 0; i < nitems(tuntap_drivers); ++i) {
 733                 drv = &tuntap_drivers[i];
 734                 delete_unrhdr(drv->unrhdr);
 735                 clone_cleanup(&drv->clones);
 736         }
 737         mtx_destroy(&tunmtx);
 738 }
 739 SYSUNINIT(tun_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY, tun_uninit, NULL);
 740
 741 static struct tuntap_driver *
 742 tuntap_driver_from_ifnet(const struct ifnet *ifp)
 743 {
 744         struct tuntap_driver *drv;
 745         int i;
 746
 747         if (ifp == NULL)
 748                 return (NULL);
 749
 750         for (i = 0; i < nitems(tuntap_drivers); ++i) {
 751                 drv = &tuntap_drivers[i];
 752                 if (strcmp(ifp->if_dname, drv->cdevsw.d_name) == 0)
 753                         return (drv);
 754         }
 755
 756         return (NULL);
 757 }
 758
 759 static int
 760 tuntapmodevent(module_t mod, int type, void *data)
 761 {
 762         struct tuntap_driver *drv;
 763         int i;
 764
 765         switch (type) {
 766         case MOD_LOAD:
 767                 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF);
 768                 for (i = 0; i < nitems(tuntap_drivers); ++i) {
 769                         drv = &tuntap_drivers[i];
 770                         clone_setup(&drv->clones);
 771                         drv->unrhdr = new_unrhdr(0, IF_MAXUNIT, &tunmtx);
 772                 }
 773                 arrival_tag = EVENTHANDLER_REGISTER(ifnet_arrival_event,
 774                    tunrename, 0, 1000);
 775                 if (arrival_tag == NULL)
 776                         return (ENOMEM);
 777                 clone_tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000);
 778                 if (clone_tag == NULL)
 779                         return (ENOMEM);
 780                 break;
 781         case MOD_UNLOAD:
 782                 /* See tun_uninit, so it's done after the vnet_sysuninit() */
 783                 break;
 784         default:
 785                 return EOPNOTSUPP;
 786         }
 787         return 0;
 788 }
 789
 790 static moduledata_t tuntap_mod = {
 791         "if_tuntap",
 792         tuntapmodevent,
 793         0
 794 };
 795
 796 /* We'll only ever have these two, so no need for a macro. */
 797 static moduledata_t tun_mod = { "if_tun", NULL, 0 };
 798 static moduledata_t tap_mod = { "if_tap", NULL, 0 };
 799
 800 DECLARE_MODULE(if_tuntap, tuntap_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 801 MODULE_VERSION(if_tuntap, 1);
 802 DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 803 MODULE_VERSION(if_tun, 1);
 804 DECLARE_MODULE(if_tap, tap_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 805 MODULE_VERSION(if_tap, 1);
 806
 807 static int
 808 tun_create_device(struct tuntap_driver *drv, int unit, struct ucred *cr,
 809     struct cdev **dev, const char *name)
 810 {
 811         struct make_dev_args args;
 812         struct tuntap_softc *tp;
 813         int error;
 814
 815         tp = malloc(sizeof(*tp), M_TUN, M_WAITOK | M_ZERO);
 816         mtx_init(&tp->tun_mtx, "tun_mtx", NULL, MTX_DEF);
 817         cv_init(&tp->tun_cv, "tun_condvar");
 818         tp->tun_flags = drv->ident_flags;
 819         tp->tun_drv = drv;
 820
 821         make_dev_args_init(&args);
 822         if (cr != NULL)
 823                 args.mda_flags = MAKEDEV_REF | MAKEDEV_CHECKNAME;
 824         args.mda_devsw = &drv->cdevsw;
 825         args.mda_cr = cr;
 826         args.mda_uid = UID_UUCP;
 827         args.mda_gid = GID_DIALER;
 828         args.mda_mode = 0600;
 829         args.mda_unit = unit;
 830         args.mda_si_drv1 = tp;
 831         error = make_dev_s(&args, dev, "%s", name);
 832         if (error != 0) {
 833                 free(tp, M_TUN);
 834                 return (error);
 835         }
 836
 837         KASSERT((*dev)->si_drv1 != NULL,
 838             ("Failed to set si_drv1 at %s creation", name));
 839         tp->tun_dev = *dev;
 840         knlist_init_mtx(&tp->tun_rsel.si_note, &tp->tun_mtx);
 841         mtx_lock(&tunmtx);
 842         TAILQ_INSERT_TAIL(&tunhead, tp, tun_list);
 843         mtx_unlock(&tunmtx);
 844         return (0);
 845 }
 846
 847 static void
 848 tunstart(struct ifnet *ifp)
 849 {
 850         struct tuntap_softc *tp = ifp->if_softc;
 851         struct mbuf *m;
 852
 853         TUNDEBUG(ifp, "starting\n");
 854         if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
 855                 IFQ_LOCK(&ifp->if_snd);
 856                 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
 857                 if (m == NULL) {
 858                         IFQ_UNLOCK(&ifp->if_snd);
 859                         return;
 860                 }
 861                 IFQ_UNLOCK(&ifp->if_snd);
 862         }
 863
 864         TUN_LOCK(tp);
 865         if (tp->tun_flags & TUN_RWAIT) {
 866                 tp->tun_flags &= ~TUN_RWAIT;
 867                 wakeup(tp);
 868         }
 869         selwakeuppri(&tp->tun_rsel, PZERO + 1);
 870         KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
 871         if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) {
 872                 TUN_UNLOCK(tp);
 873                 pgsigio(&tp->tun_sigio, SIGIO, 0);
 874         } else
 875                 TUN_UNLOCK(tp);
 876 }
 877
 878 /*
 879  * tunstart_l2
 880  *
 881  * queue packets from higher level ready to put out
 882  */
 883 static void
 884 tunstart_l2(struct ifnet *ifp)
 885 {
 886         struct tuntap_softc     *tp = ifp->if_softc;
 887
 888         TUNDEBUG(ifp, "starting\n");
 889
 890         /*
 891          * do not junk pending output if we are in VMnet mode.
 892          * XXX: can this do any harm because of queue overflow?
 893          */
 894
 895         TUN_LOCK(tp);
 896         if (((tp->tun_flags & TUN_VMNET) == 0) &&
 897             ((tp->tun_flags & TUN_READY) != TUN_READY)) {
 898                 struct mbuf *m;
 899
 900                 /* Unlocked read. */
 901                 TUNDEBUG(ifp, "not ready, tun_flags = 0x%x\n", tp->tun_flags);
 902
 903                 for (;;) {
 904                         IF_DEQUEUE(&ifp->if_snd, m);
 905                         if (m != NULL) {
 906                                 m_freem(m);
 907                                 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
 908                         } else
 909                                 break;
 910                 }
 911                 TUN_UNLOCK(tp);
 912
 913                 return;
 914         }
 915
 916         ifp->if_drv_flags |= IFF_DRV_OACTIVE;
 917
 918         if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
 919                 if (tp->tun_flags & TUN_RWAIT) {
 920                         tp->tun_flags &= ~TUN_RWAIT;
 921                         wakeup(tp);
 922                 }
 923
 924                 if ((tp->tun_flags & TUN_ASYNC) && (tp->tun_sigio != NULL)) {
 925                         TUN_UNLOCK(tp);
 926                         pgsigio(&tp->tun_sigio, SIGIO, 0);
 927                         TUN_LOCK(tp);
 928                 }
 929
 930                 selwakeuppri(&tp->tun_rsel, PZERO+1);
 931                 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
 932                 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); /* obytes are counted in ether_output */
 933         }
 934
 935         ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
 936         TUN_UNLOCK(tp);
 937 } /* tunstart_l2 */
 938
 939 static int
 940 tap_transmit(struct ifnet *ifp, struct mbuf *m)
 941 {
 942         int error;
 943
 944         BPF_MTAP(ifp, m);
 945         IFQ_HANDOFF(ifp, m, error);
 946         return (error);
 947 }
 948
 949 /* XXX: should return an error code so it can fail. */
 950 static void
 951 tuncreate(struct cdev *dev)
 952 {
 953         struct tuntap_driver *drv;
 954         struct tuntap_softc *tp;
 955         struct ifnet *ifp;
 956         struct ether_addr eaddr;
 957         int iflags;
 958         u_char type;
 959
 960         tp = dev->si_drv1;
 961         KASSERT(tp != NULL,
 962             ("si_drv1 should have been initialized at creation"));
 963
 964         drv = tp->tun_drv;
 965         iflags = IFF_MULTICAST;
 966         if ((tp->tun_flags & TUN_L2) != 0) {
 967                 type = IFT_ETHER;
 968                 iflags |= IFF_BROADCAST | IFF_SIMPLEX;
 969         } else {
 970                 type = IFT_PPP;
 971                 iflags |= IFF_POINTOPOINT;
 972         }
 973         ifp = tp->tun_ifp = if_alloc(type);
 974         if (ifp == NULL)
 975                 panic("%s%d: failed to if_alloc() interface.\n",
 976                     drv->cdevsw.d_name, dev2unit(dev));
 977         ifp->if_softc = tp;
 978         if_initname(ifp, drv->cdevsw.d_name, dev2unit(dev));
 979         ifp->if_ioctl = tunifioctl;
 980         ifp->if_flags = iflags;
 981         IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
 982         ifp->if_capabilities |= IFCAP_LINKSTATE;
 983         if ((tp->tun_flags & TUN_L2) != 0)
 984                 ifp->if_capabilities |=
 985                     IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6 | IFCAP_LRO;
 986         ifp->if_capenable |= IFCAP_LINKSTATE;
 987
 988         if ((tp->tun_flags & TUN_L2) != 0) {
 989                 ifp->if_init = tunifinit;
 990                 ifp->if_start = tunstart_l2;
 991                 ifp->if_transmit = tap_transmit;
 992                 ifp->if_qflush = if_qflush;
 993
 994                 ether_gen_addr(ifp, &eaddr);
 995                 ether_ifattach(ifp, eaddr.octet);
 996         } else {
 997                 ifp->if_mtu = TUNMTU;
 998                 ifp->if_start = tunstart;
 999                 ifp->if_output = tunoutput;
1000
1001                 ifp->if_snd.ifq_drv_maxlen = 0;
1002                 IFQ_SET_READY(&ifp->if_snd);
1003
1004                 if_attach(ifp);
1005                 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
1006         }
1007
1008         TUN_LOCK(tp);
1009         tp->tun_flags |= TUN_INITED;
1010         TUN_UNLOCK(tp);
1011
1012         TUNDEBUG(ifp, "interface %s is created, minor = %#x\n",
1013             ifp->if_xname, dev2unit(dev));
1014 }
1015
1016 static void
1017 tunrename(void *arg __unused, struct ifnet *ifp)
1018 {
1019         struct tuntap_softc *tp;
1020         int error;
1021
1022         if ((ifp->if_flags & IFF_RENAMING) == 0)
1023                 return;
1024
1025         if (tuntap_driver_from_ifnet(ifp) == NULL)
1026                 return;
1027
1028         /*
1029          * We need to grab the ioctl sx long enough to make sure the softc is
1030          * still there.  If it is, we can safely try to busy the tun device.
1031          * The busy may fail if the device is currently dying, in which case
1032          * we do nothing.  If it doesn't fail, the busy count stops the device
1033          * from dying until we've created the alias (that will then be
1034          * subsequently destroyed).
1035          */
1036         sx_xlock(&tun_ioctl_sx);
1037         tp = ifp->if_softc;
1038         if (tp == NULL) {
1039                 sx_xunlock(&tun_ioctl_sx);
1040                 return;
1041         }
1042         error = tun_busy(tp);
1043         sx_xunlock(&tun_ioctl_sx);
1044         if (error != 0)
1045                 return;
1046         if (tp->tun_alias != NULL) {
1047                 destroy_dev(tp->tun_alias);
1048                 tp->tun_alias = NULL;
1049         }
1050
1051         if (strcmp(ifp->if_xname, tp->tun_dev->si_name) == 0)
1052                 goto out;
1053
1054         /*
1055          * Failure's ok, aliases are created on a best effort basis.  If a
1056          * tun user/consumer decides to rename the interface to conflict with
1057          * another device (non-ifnet) on the system, we will assume they know
1058          * what they are doing.  make_dev_alias_p won't touch tun_alias on
1059          * failure, so we use it but ignore the return value.
1060          */
1061         make_dev_alias_p(MAKEDEV_CHECKNAME, &tp->tun_alias, tp->tun_dev, "%s",
1062             ifp->if_xname);
1063 out:
1064         tun_unbusy(tp);
1065 }
1066
1067 static int
1068 tunopen(struct cdev *dev, int flag, int mode, struct thread *td)
1069 {
1070         struct ifnet    *ifp;
1071         struct tuntap_softc *tp;
1072         int error __diagused, tunflags;
1073
1074         tunflags = 0;
1075         CURVNET_SET(TD_TO_VNET(td));
1076         error = tuntap_name2info(dev->si_name, NULL, &tunflags);
1077         if (error != 0) {
1078                 CURVNET_RESTORE();
1079                 return (error); /* Shouldn't happen */
1080         }
1081
1082         tp = dev->si_drv1;
1083         KASSERT(tp != NULL,
1084             ("si_drv1 should have been initialized at creation"));
1085
1086         TUN_LOCK(tp);
1087         if ((tp->tun_flags & TUN_INITED) == 0) {
1088                 TUN_UNLOCK(tp);
1089                 CURVNET_RESTORE();
1090                 return (ENXIO);
1091         }
1092         if ((tp->tun_flags & (TUN_OPEN | TUN_DYING)) != 0) {
1093                 TUN_UNLOCK(tp);
1094                 CURVNET_RESTORE();
1095                 return (EBUSY);
1096         }
1097
1098         error = tun_busy_locked(tp);
1099         KASSERT(error == 0, ("Must be able to busy an unopen tunnel"));
1100         ifp = TUN2IFP(tp);
1101
1102         if ((tp->tun_flags & TUN_L2) != 0) {
1103                 bcopy(IF_LLADDR(ifp), tp->tun_ether.octet,
1104                     sizeof(tp->tun_ether.octet));
1105
1106                 ifp->if_drv_flags |= IFF_DRV_RUNNING;
1107                 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1108
1109                 if (tapuponopen)
1110                         ifp->if_flags |= IFF_UP;
1111         }
1112
1113         tp->tun_pid = td->td_proc->p_pid;
1114         tp->tun_flags |= TUN_OPEN;
1115
1116         if_link_state_change(ifp, LINK_STATE_UP);
1117         TUNDEBUG(ifp, "open\n");
1118         TUN_UNLOCK(tp);
1119
1120         /*
1121          * This can fail with either ENOENT or EBUSY.  This is in the middle of
1122          * d_open, so ENOENT should not be possible.  EBUSY is possible, but
1123          * the only cdevpriv dtor being set will be tundtor and the softc being
1124          * passed is constant for a given cdev.  We ignore the possible error
1125          * because of this as either "unlikely" or "not actually a problem."
1126          */
1127         (void)devfs_set_cdevpriv(tp, tundtor);
1128         CURVNET_RESTORE();
1129         return (0);
1130 }
1131
1132 /*
1133  * tundtor - tear down the device - mark i/f down & delete
1134  * routing info
1135  */
1136 static void
1137 tundtor(void *data)
1138 {
1139         struct proc *p;
1140         struct tuntap_softc *tp;
1141         struct ifnet *ifp;
1142         bool l2tun;
1143
1144         tp = data;
1145         p = curproc;
1146         ifp = TUN2IFP(tp);
1147
1148         TUN_LOCK(tp);
1149
1150         /*
1151          * Realistically, we can't be obstinate here.  This only means that the
1152          * tuntap device was closed out of order, and the last closer wasn't the
1153          * controller.  These are still good to know about, though, as software
1154          * should avoid multiple processes with a tuntap device open and
1155          * ill-defined transfer of control (e.g., handoff, TUNSIFPID, close in
1156          * parent).
1157          */
1158         if (p->p_pid != tp->tun_pid) {
1159                 log(LOG_INFO,
1160                     "pid %d (%s), %s: tun/tap protocol violation, non-controlling process closed last.\n",
1161                     p->p_pid, p->p_comm, tp->tun_dev->si_name);
1162         }
1163
1164         /*
1165          * junk all pending output
1166          */
1167         CURVNET_SET(ifp->if_vnet);
1168
1169         l2tun = false;
1170         if ((tp->tun_flags & TUN_L2) != 0) {
1171                 l2tun = true;
1172                 IF_DRAIN(&ifp->if_snd);
1173         } else {
1174                 IFQ_PURGE(&ifp->if_snd);
1175         }
1176
1177         /* For vmnet, we won't do most of the address/route bits */
1178         if ((tp->tun_flags & TUN_VMNET) != 0 ||
1179             (l2tun && (ifp->if_flags & IFF_LINK0) != 0))
1180                 goto out;
1181 #if defined(INET) || defined(INET6)
1182         if (l2tun && tp->tun_lro_ready) {
1183                 TUNDEBUG (ifp, "LRO disabled\n");
1184                 tcp_lro_free(&tp->tun_lro);
1185                 tp->tun_lro_ready = false;
1186         }
1187 #endif
1188         if (ifp->if_flags & IFF_UP) {
1189                 TUN_UNLOCK(tp);
1190                 if_down(ifp);
1191                 TUN_LOCK(tp);
1192         }
1193
1194         /* Delete all addresses and routes which reference this interface. */
1195         if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
1196                 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1197                 TUN_UNLOCK(tp);
1198                 if_purgeaddrs(ifp);
1199                 TUN_LOCK(tp);
1200         }
1201
1202 out:
1203         if_link_state_change(ifp, LINK_STATE_DOWN);
1204         CURVNET_RESTORE();
1205
1206         funsetown(&tp->tun_sigio);
1207         selwakeuppri(&tp->tun_rsel, PZERO + 1);
1208         KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
1209         TUNDEBUG (ifp, "closed\n");
1210         tp->tun_flags &= ~TUN_OPEN;
1211         tp->tun_pid = 0;
1212         tun_vnethdr_set(ifp, 0);
1213
1214         tun_unbusy_locked(tp);
1215         TUN_UNLOCK(tp);
1216 }
1217
1218 static void
1219 tuninit(struct ifnet *ifp)
1220 {
1221         struct tuntap_softc *tp = ifp->if_softc;
1222
1223         TUNDEBUG(ifp, "tuninit\n");
1224
1225         TUN_LOCK(tp);
1226         ifp->if_drv_flags |= IFF_DRV_RUNNING;
1227         if ((tp->tun_flags & TUN_L2) == 0) {
1228                 ifp->if_flags |= IFF_UP;
1229                 getmicrotime(&ifp->if_lastchange);
1230                 TUN_UNLOCK(tp);
1231         } else {
1232 #if defined(INET) || defined(INET6)
1233                 if (tcp_lro_init(&tp->tun_lro) == 0) {
1234                         TUNDEBUG(ifp, "LRO enabled\n");
1235                         tp->tun_lro.ifp = ifp;
1236                         tp->tun_lro_ready = true;
1237                 } else {
1238                         TUNDEBUG(ifp, "Could not enable LRO\n");
1239                         tp->tun_lro_ready = false;
1240                 }
1241 #endif
1242                 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1243                 TUN_UNLOCK(tp);
1244                 /* attempt to start output */
1245                 tunstart_l2(ifp);
1246         }
1247
1248 }
1249
1250 /*
1251  * Used only for l2 tunnel.
1252  */
1253 static void
1254 tunifinit(void *xtp)
1255 {
1256         struct tuntap_softc *tp;
1257
1258         tp = (struct tuntap_softc *)xtp;
1259         tuninit(tp->tun_ifp);
1260 }
1261
1262 /*
1263  * To be called under TUN_LOCK. Update ifp->if_hwassist according to the
1264  * current value of ifp->if_capenable.
1265  */
1266 static void
1267 tun_caps_changed(struct ifnet *ifp)
1268 {
1269         uint64_t hwassist = 0;
1270
1271         TUN_LOCK_ASSERT((struct tuntap_softc *)ifp->if_softc);
1272         if (ifp->if_capenable & IFCAP_TXCSUM)
1273                 hwassist |= CSUM_TCP | CSUM_UDP;
1274         if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
1275                 hwassist |= CSUM_TCP_IPV6
1276                     | CSUM_UDP_IPV6;
1277         if (ifp->if_capenable & IFCAP_TSO4)
1278                 hwassist |= CSUM_IP_TSO;
1279         if (ifp->if_capenable & IFCAP_TSO6)
1280                 hwassist |= CSUM_IP6_TSO;
1281         ifp->if_hwassist = hwassist;
1282 }
1283
1284 /*
1285  * To be called under TUN_LOCK. Update tp->tun_vhdrlen and adjust
1286  * if_capabilities and if_capenable as needed.
1287  */
1288 static void
1289 tun_vnethdr_set(struct ifnet *ifp, int vhdrlen)
1290 {
1291         struct tuntap_softc *tp = ifp->if_softc;
1292
1293         TUN_LOCK_ASSERT(tp);
1294
1295         if (tp->tun_vhdrlen == vhdrlen)
1296                 return;
1297
1298         /*
1299          * Update if_capabilities to reflect the
1300          * functionalities offered by the virtio-net
1301          * header.
1302          */
1303         if (vhdrlen != 0)
1304                 ifp->if_capabilities |=
1305                         TAP_VNET_HDR_CAPS;
1306         else
1307                 ifp->if_capabilities &=
1308                         ~TAP_VNET_HDR_CAPS;
1309         /*
1310          * Disable any capabilities that we don't
1311          * support anymore.
1312          */
1313         ifp->if_capenable &= ifp->if_capabilities;
1314         tun_caps_changed(ifp);
1315         tp->tun_vhdrlen = vhdrlen;
1316
1317         TUNDEBUG(ifp, "vnet_hdr_len=%d, if_capabilities=%x\n",
1318             vhdrlen, ifp->if_capabilities);
1319 }
1320
1321 /*
1322  * Process an ioctl request.
1323  */
1324 static int
1325 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1326 {
1327         struct ifreq *ifr = (struct ifreq *)data;
1328         struct tuntap_softc *tp;
1329         struct ifstat *ifs;
1330         struct ifmediareq       *ifmr;
1331         int             dummy, error = 0;
1332         bool            l2tun;
1333
1334         ifmr = NULL;
1335         sx_xlock(&tun_ioctl_sx);
1336         tp = ifp->if_softc;
1337         if (tp == NULL) {
1338                 error = ENXIO;
1339                 goto bad;
1340         }
1341         l2tun = (tp->tun_flags & TUN_L2) != 0;
1342         switch(cmd) {
1343         case SIOCGIFSTATUS:
1344                 ifs = (struct ifstat *)data;
1345                 TUN_LOCK(tp);
1346                 if (tp->tun_pid)
1347                         snprintf(ifs->ascii, sizeof(ifs->ascii),
1348                             "\tOpened by PID %d\n", tp->tun_pid);
1349                 else
1350                         ifs->ascii[0] = '\0';
1351                 TUN_UNLOCK(tp);
1352                 break;
1353         case SIOCSIFADDR:
1354                 if (l2tun)
1355                         error = ether_ioctl(ifp, cmd, data);
1356                 else
1357                         tuninit(ifp);
1358                 if (error == 0)
1359                     TUNDEBUG(ifp, "address set\n");
1360                 break;
1361         case SIOCSIFMTU:
1362                 ifp->if_mtu = ifr->ifr_mtu;
1363                 TUNDEBUG(ifp, "mtu set\n");
1364                 break;
1365         case SIOCSIFFLAGS:
1366         case SIOCADDMULTI:
1367         case SIOCDELMULTI:
1368                 break;
1369         case SIOCGIFMEDIA:
1370                 if (!l2tun) {
1371                         error = EINVAL;
1372                         break;
1373                 }
1374
1375                 ifmr = (struct ifmediareq *)data;
1376                 dummy = ifmr->ifm_count;
1377                 ifmr->ifm_count = 1;
1378                 ifmr->ifm_status = IFM_AVALID;
1379                 ifmr->ifm_active = IFM_ETHER | IFM_FDX | IFM_1000_T;
1380                 if (tp->tun_flags & TUN_OPEN)
1381                         ifmr->ifm_status |= IFM_ACTIVE;
1382                 ifmr->ifm_current = ifmr->ifm_active;
1383                 if (dummy >= 1) {
1384                         int media = IFM_ETHER;
1385                         error = copyout(&media, ifmr->ifm_ulist, sizeof(int));
1386                 }
1387                 break;
1388         case SIOCSIFCAP:
1389                 TUN_LOCK(tp);
1390                 ifp->if_capenable = ifr->ifr_reqcap;
1391                 tun_caps_changed(ifp);
1392                 TUN_UNLOCK(tp);
1393                 VLAN_CAPABILITIES(ifp);
1394                 break;
1395         default:
1396                 if (l2tun) {
1397                         error = ether_ioctl(ifp, cmd, data);
1398                 } else {
1399                         error = EINVAL;
1400                 }
1401         }
1402 bad:
1403         sx_xunlock(&tun_ioctl_sx);
1404         return (error);
1405 }
1406
1407 /*
1408  * tunoutput - queue packets from higher level ready to put out.
1409  */
1410 static int
1411 tunoutput(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
1412     struct route *ro)
1413 {
1414         struct tuntap_softc *tp = ifp->if_softc;
1415         u_short cached_tun_flags;
1416         int error;
1417         u_int32_t af;
1418
1419         TUNDEBUG (ifp, "tunoutput\n");
1420
1421 #ifdef MAC
1422         error = mac_ifnet_check_transmit(ifp, m0);
1423         if (error) {
1424                 m_freem(m0);
1425                 return (error);
1426         }
1427 #endif
1428
1429         /* Could be unlocked read? */
1430         TUN_LOCK(tp);
1431         cached_tun_flags = tp->tun_flags;
1432         TUN_UNLOCK(tp);
1433         if ((cached_tun_flags & TUN_READY) != TUN_READY) {
1434                 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
1435                 m_freem (m0);
1436                 return (EHOSTDOWN);
1437         }
1438
1439         if ((ifp->if_flags & IFF_UP) != IFF_UP) {
1440                 m_freem (m0);
1441                 return (EHOSTDOWN);
1442         }
1443
1444         /* BPF writes need to be handled specially. */
1445         if (dst->sa_family == AF_UNSPEC)
1446                 bcopy(dst->sa_data, &af, sizeof(af));
1447         else
1448                 af = RO_GET_FAMILY(ro, dst);
1449
1450         BPF_MTAP2(ifp, &af, sizeof(af), m0);
1451
1452         /* prepend sockaddr? this may abort if the mbuf allocation fails */
1453         if (cached_tun_flags & TUN_LMODE) {
1454                 /* allocate space for sockaddr */
1455                 M_PREPEND(m0, dst->sa_len, M_NOWAIT);
1456
1457                 /* if allocation failed drop packet */
1458                 if (m0 == NULL) {
1459                         if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1460                         if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1461                         return (ENOBUFS);
1462                 } else {
1463                         bcopy(dst, m0->m_data, dst->sa_len);
1464                 }
1465         }
1466
1467         if (cached_tun_flags & TUN_IFHEAD) {
1468                 /* Prepend the address family */
1469                 M_PREPEND(m0, 4, M_NOWAIT);
1470
1471                 /* if allocation failed drop packet */
1472                 if (m0 == NULL) {
1473                         if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1474                         if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1475                         return (ENOBUFS);
1476                 } else
1477                         *(u_int32_t *)m0->m_data = htonl(af);
1478         } else {
1479 #ifdef INET
1480                 if (af != AF_INET)
1481 #endif
1482                 {
1483                         m_freem(m0);
1484                         return (EAFNOSUPPORT);
1485                 }
1486         }
1487
1488         error = (ifp->if_transmit)(ifp, m0);
1489         if (error)
1490                 return (ENOBUFS);
1491         if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
1492         return (0);
1493 }
1494
1495 /*
1496  * the cdevsw interface is now pretty minimal.
1497  */
1498 static  int
1499 tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag,
1500     struct thread *td)
1501 {
1502         struct ifreq ifr, *ifrp;
1503         struct tuntap_softc *tp = dev->si_drv1;
1504         struct ifnet *ifp = TUN2IFP(tp);
1505         struct tuninfo *tunp;
1506         int error, iflags, ival;
1507         bool    l2tun;
1508
1509         l2tun = (tp->tun_flags & TUN_L2) != 0;
1510         if (l2tun) {
1511                 /* tap specific ioctls */
1512                 switch(cmd) {
1513                 /* VMware/VMnet port ioctl's */
1514 #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
1515     defined(COMPAT_FREEBSD4)
1516                 case _IO('V', 0):
1517                         ival = IOCPARM_IVAL(data);
1518                         data = (caddr_t)&ival;
1519                         /* FALLTHROUGH */
1520 #endif
1521                 case VMIO_SIOCSIFFLAGS: /* VMware/VMnet SIOCSIFFLAGS */
1522                         iflags = *(int *)data;
1523                         iflags &= TUN_VMIO_FLAG_MASK;
1524                         iflags &= ~IFF_CANTCHANGE;
1525                         iflags |= IFF_UP;
1526
1527                         TUN_LOCK(tp);
1528                         ifp->if_flags = iflags |
1529                             (ifp->if_flags & IFF_CANTCHANGE);
1530                         TUN_UNLOCK(tp);
1531
1532                         return (0);
1533                 case SIOCGIFADDR:       /* get MAC address of the remote side */
1534                         TUN_LOCK(tp);
1535                         bcopy(&tp->tun_ether.octet, data,
1536                             sizeof(tp->tun_ether.octet));
1537                         TUN_UNLOCK(tp);
1538
1539                         return (0);
1540                 case SIOCSIFADDR:       /* set MAC address of the remote side */
1541                         TUN_LOCK(tp);
1542                         bcopy(data, &tp->tun_ether.octet,
1543                             sizeof(tp->tun_ether.octet));
1544                         TUN_UNLOCK(tp);
1545
1546                         return (0);
1547                 case TAPSVNETHDR:
1548                         ival = *(int *)data;
1549                         if (ival != 0 &&
1550                             ival != sizeof(struct virtio_net_hdr) &&
1551                             ival != sizeof(struct virtio_net_hdr_mrg_rxbuf)) {
1552                                 return (EINVAL);
1553                         }
1554                         TUN_LOCK(tp);
1555                         tun_vnethdr_set(ifp, ival);
1556                         TUN_UNLOCK(tp);
1557
1558                         return (0);
1559                 case TAPGVNETHDR:
1560                         TUN_LOCK(tp);
1561                         *(int *)data = tp->tun_vhdrlen;
1562                         TUN_UNLOCK(tp);
1563
1564                         return (0);
1565                 }
1566
1567                 /* Fall through to the common ioctls if unhandled */
1568         } else {
1569                 switch (cmd) {
1570                 case TUNSLMODE:
1571                         TUN_LOCK(tp);
1572                         if (*(int *)data) {
1573                                 tp->tun_flags |= TUN_LMODE;
1574                                 tp->tun_flags &= ~TUN_IFHEAD;
1575                         } else
1576                                 tp->tun_flags &= ~TUN_LMODE;
1577                         TUN_UNLOCK(tp);
1578
1579                         return (0);
1580                 case TUNSIFHEAD:
1581                         TUN_LOCK(tp);
1582                         if (*(int *)data) {
1583                                 tp->tun_flags |= TUN_IFHEAD;
1584                                 tp->tun_flags &= ~TUN_LMODE;
1585                         } else
1586                                 tp->tun_flags &= ~TUN_IFHEAD;
1587                         TUN_UNLOCK(tp);
1588
1589                         return (0);
1590                 case TUNGIFHEAD:
1591                         TUN_LOCK(tp);
1592                         *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
1593                         TUN_UNLOCK(tp);
1594
1595                         return (0);
1596                 case TUNSIFMODE:
1597                         /* deny this if UP */
1598                         if (TUN2IFP(tp)->if_flags & IFF_UP)
1599                                 return (EBUSY);
1600
1601                         switch (*(int *)data & ~IFF_MULTICAST) {
1602                         case IFF_POINTOPOINT:
1603                         case IFF_BROADCAST:
1604                                 TUN_LOCK(tp);
1605                                 TUN2IFP(tp)->if_flags &=
1606                                     ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
1607                                 TUN2IFP(tp)->if_flags |= *(int *)data;
1608                                 TUN_UNLOCK(tp);
1609
1610                                 break;
1611                         default:
1612                                 return (EINVAL);
1613                         }
1614
1615                         return (0);
1616                 case TUNSIFPID:
1617                         TUN_LOCK(tp);
1618                         tp->tun_pid = curthread->td_proc->p_pid;
1619                         TUN_UNLOCK(tp);
1620
1621                         return (0);
1622                 }
1623                 /* Fall through to the common ioctls if unhandled */
1624         }
1625
1626         switch (cmd) {
1627         case TUNGIFNAME:
1628                 ifrp = (struct ifreq *)data;
1629                 strlcpy(ifrp->ifr_name, TUN2IFP(tp)->if_xname, IFNAMSIZ);
1630
1631                 return (0);
1632         case TUNSIFINFO:
1633                 tunp = (struct tuninfo *)data;
1634                 if (TUN2IFP(tp)->if_type != tunp->type)
1635                         return (EPROTOTYPE);
1636                 TUN_LOCK(tp);
1637                 if (TUN2IFP(tp)->if_mtu != tunp->mtu) {
1638                         strlcpy(ifr.ifr_name, if_name(TUN2IFP(tp)), IFNAMSIZ);
1639                         ifr.ifr_mtu = tunp->mtu;
1640                         CURVNET_SET(TUN2IFP(tp)->if_vnet);
1641                         error = ifhwioctl(SIOCSIFMTU, TUN2IFP(tp),
1642                             (caddr_t)&ifr, td);
1643                         CURVNET_RESTORE();
1644                         if (error) {
1645                                 TUN_UNLOCK(tp);
1646                                 return (error);
1647                         }
1648                 }
1649                 TUN2IFP(tp)->if_baudrate = tunp->baudrate;
1650                 TUN_UNLOCK(tp);
1651                 break;
1652         case TUNGIFINFO:
1653                 tunp = (struct tuninfo *)data;
1654                 TUN_LOCK(tp);
1655                 tunp->mtu = TUN2IFP(tp)->if_mtu;
1656                 tunp->type = TUN2IFP(tp)->if_type;
1657                 tunp->baudrate = TUN2IFP(tp)->if_baudrate;
1658                 TUN_UNLOCK(tp);
1659                 break;
1660         case TUNSDEBUG:
1661                 tundebug = *(int *)data;
1662                 break;
1663         case TUNGDEBUG:
1664                 *(int *)data = tundebug;
1665                 break;
1666         case FIONBIO:
1667                 break;
1668         case FIOASYNC:
1669                 TUN_LOCK(tp);
1670                 if (*(int *)data)
1671                         tp->tun_flags |= TUN_ASYNC;
1672                 else
1673                         tp->tun_flags &= ~TUN_ASYNC;
1674                 TUN_UNLOCK(tp);
1675                 break;
1676         case FIONREAD:
1677                 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) {
1678                         struct mbuf *mb;
1679                         IFQ_LOCK(&TUN2IFP(tp)->if_snd);
1680                         IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb);
1681                         for (*(int *)data = 0; mb != NULL; mb = mb->m_next)
1682                                 *(int *)data += mb->m_len;
1683                         IFQ_UNLOCK(&TUN2IFP(tp)->if_snd);
1684                 } else
1685                         *(int *)data = 0;
1686                 break;
1687         case FIOSETOWN:
1688                 return (fsetown(*(int *)data, &tp->tun_sigio));
1689
1690         case FIOGETOWN:
1691                 *(int *)data = fgetown(&tp->tun_sigio);
1692                 return (0);
1693
1694         /* This is deprecated, FIOSETOWN should be used instead. */
1695         case TIOCSPGRP:
1696                 return (fsetown(-(*(int *)data), &tp->tun_sigio));
1697
1698         /* This is deprecated, FIOGETOWN should be used instead. */
1699         case TIOCGPGRP:
1700                 *(int *)data = -fgetown(&tp->tun_sigio);
1701                 return (0);
1702
1703         default:
1704                 return (ENOTTY);
1705         }
1706         return (0);
1707 }
1708
1709 /*
1710  * The cdevsw read interface - reads a packet at a time, or at
1711  * least as much of a packet as can be read.
1712  */
1713 static  int
1714 tunread(struct cdev *dev, struct uio *uio, int flag)
1715 {
1716         struct tuntap_softc *tp = dev->si_drv1;
1717         struct ifnet    *ifp = TUN2IFP(tp);
1718         struct mbuf     *m;
1719         size_t          len;
1720         int             error = 0;
1721
1722         TUNDEBUG (ifp, "read\n");
1723         TUN_LOCK(tp);
1724         if ((tp->tun_flags & TUN_READY) != TUN_READY) {
1725                 TUN_UNLOCK(tp);
1726                 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
1727                 return (EHOSTDOWN);
1728         }
1729
1730         tp->tun_flags &= ~TUN_RWAIT;
1731
1732         for (;;) {
1733                 IFQ_DEQUEUE(&ifp->if_snd, m);
1734                 if (m != NULL)
1735                         break;
1736                 if (flag & O_NONBLOCK) {
1737                         TUN_UNLOCK(tp);
1738                         return (EWOULDBLOCK);
1739                 }
1740                 tp->tun_flags |= TUN_RWAIT;
1741                 error = mtx_sleep(tp, &tp->tun_mtx, PCATCH | (PZERO + 1),
1742                     "tunread", 0);
1743                 if (error != 0) {
1744                         TUN_UNLOCK(tp);
1745                         return (error);
1746                 }
1747         }
1748         TUN_UNLOCK(tp);
1749
1750         len = min(tp->tun_vhdrlen, uio->uio_resid);
1751         if (len > 0) {
1752                 struct virtio_net_hdr_mrg_rxbuf vhdr;
1753
1754                 bzero(&vhdr, sizeof(vhdr));
1755                 if (m->m_pkthdr.csum_flags & TAP_ALL_OFFLOAD) {
1756                         m = virtio_net_tx_offload(ifp, m, false, &vhdr.hdr);
1757                 }
1758
1759                 TUNDEBUG(ifp, "txvhdr: f %u, gt %u, hl %u, "
1760                     "gs %u, cs %u, co %u\n", vhdr.hdr.flags,
1761                     vhdr.hdr.gso_type, vhdr.hdr.hdr_len,
1762                     vhdr.hdr.gso_size, vhdr.hdr.csum_start,
1763                     vhdr.hdr.csum_offset);
1764                 error = uiomove(&vhdr, len, uio);
1765         }
1766
1767         while (m && uio->uio_resid > 0 && error == 0) {
1768                 len = min(uio->uio_resid, m->m_len);
1769                 if (len != 0)
1770                         error = uiomove(mtod(m, void *), len, uio);
1771                 m = m_free(m);
1772         }
1773
1774         if (m) {
1775                 TUNDEBUG(ifp, "Dropping mbuf\n");
1776                 m_freem(m);
1777         }
1778         return (error);
1779 }
1780
1781 static int
1782 tunwrite_l2(struct tuntap_softc *tp, struct mbuf *m,
1783             struct virtio_net_hdr_mrg_rxbuf *vhdr)
1784 {
1785         struct epoch_tracker et;
1786         struct ether_header *eh;
1787         struct ifnet *ifp;
1788
1789         ifp = TUN2IFP(tp);
1790
1791         /*
1792          * Only pass a unicast frame to ether_input(), if it would
1793          * actually have been received by non-virtual hardware.
1794          */
1795         if (m->m_len < sizeof(struct ether_header)) {
1796                 m_freem(m);
1797                 return (0);
1798         }
1799
1800         eh = mtod(m, struct ether_header *);
1801
1802         if ((ifp->if_flags & IFF_PROMISC) == 0 &&
1803             !ETHER_IS_MULTICAST(eh->ether_dhost) &&
1804             bcmp(eh->ether_dhost, IF_LLADDR(ifp), ETHER_ADDR_LEN) != 0) {
1805                 m_freem(m);
1806                 return (0);
1807         }
1808
1809         if (vhdr != NULL) {
1810                 if (virtio_net_rx_csum(m, &vhdr->hdr)) {
1811                         m_freem(m);
1812                         return (0);
1813                 }
1814         } else {
1815                 switch (ntohs(eh->ether_type)) {
1816 #ifdef INET
1817                 case ETHERTYPE_IP:
1818                         if (ifp->if_capenable & IFCAP_RXCSUM) {
1819                                 m->m_pkthdr.csum_flags |=
1820                                     CSUM_IP_CHECKED | CSUM_IP_VALID |
1821                                     CSUM_DATA_VALID | CSUM_SCTP_VALID |
1822                                     CSUM_PSEUDO_HDR;
1823                                 m->m_pkthdr.csum_data = 0xffff;
1824                         }
1825                         break;
1826 #endif
1827 #ifdef INET6
1828                 case ETHERTYPE_IPV6:
1829                         if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) {
1830                                 m->m_pkthdr.csum_flags |=
1831                                     CSUM_DATA_VALID_IPV6 | CSUM_SCTP_VALID |
1832                                     CSUM_PSEUDO_HDR;
1833                                 m->m_pkthdr.csum_data = 0xffff;
1834                         }
1835                         break;
1836 #endif
1837                 }
1838         }
1839
1840         /* Pass packet up to parent. */
1841         CURVNET_SET(ifp->if_vnet);
1842         NET_EPOCH_ENTER(et);
1843 #if defined(INET) || defined(INET6)
1844         if (tp->tun_lro_ready && ifp->if_capenable & IFCAP_LRO &&
1845             tcp_lro_rx(&tp->tun_lro, m, 0) == 0)
1846                 tcp_lro_flush_all(&tp->tun_lro);
1847         else
1848 #endif
1849                 (*ifp->if_input)(ifp, m);
1850         NET_EPOCH_EXIT(et);
1851         CURVNET_RESTORE();
1852         /* ibytes are counted in parent */
1853         if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1854         return (0);
1855 }
1856
1857 static int
1858 tunwrite_l3(struct tuntap_softc *tp, struct mbuf *m)
1859 {
1860         struct epoch_tracker et;
1861         struct ifnet *ifp;
1862         int family, isr;
1863
1864         ifp = TUN2IFP(tp);
1865         /* Could be unlocked read? */
1866         TUN_LOCK(tp);
1867         if (tp->tun_flags & TUN_IFHEAD) {
1868                 TUN_UNLOCK(tp);
1869                 if (m->m_len < sizeof(family) &&
1870                 (m = m_pullup(m, sizeof(family))) == NULL)
1871                         return (ENOBUFS);
1872                 family = ntohl(*mtod(m, u_int32_t *));
1873                 m_adj(m, sizeof(family));
1874         } else {
1875                 TUN_UNLOCK(tp);
1876                 family = AF_INET;
1877         }
1878
1879         BPF_MTAP2(ifp, &family, sizeof(family), m);
1880
1881         switch (family) {
1882 #ifdef INET
1883         case AF_INET:
1884                 isr = NETISR_IP;
1885                 break;
1886 #endif
1887 #ifdef INET6
1888         case AF_INET6:
1889                 isr = NETISR_IPV6;
1890                 break;
1891 #endif
1892         default:
1893                 m_freem(m);
1894                 return (EAFNOSUPPORT);
1895         }
1896         random_harvest_queue(m, sizeof(*m), RANDOM_NET_TUN);
1897         if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
1898         if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1899         CURVNET_SET(ifp->if_vnet);
1900         M_SETFIB(m, ifp->if_fib);
1901         NET_EPOCH_ENTER(et);
1902         netisr_dispatch(isr, m);
1903         NET_EPOCH_EXIT(et);
1904         CURVNET_RESTORE();
1905         return (0);
1906 }
1907
1908 /*
1909  * the cdevsw write interface - an atomic write is a packet - or else!
1910  */
1911 static  int
1912 tunwrite(struct cdev *dev, struct uio *uio, int flag)
1913 {
1914         struct virtio_net_hdr_mrg_rxbuf vhdr;
1915         struct tuntap_softc *tp;
1916         struct ifnet    *ifp;
1917         struct mbuf     *m;
1918         uint32_t        mru;
1919         int             align, vhdrlen, error;
1920         bool            l2tun;
1921
1922         tp = dev->si_drv1;
1923         ifp = TUN2IFP(tp);
1924         TUNDEBUG(ifp, "tunwrite\n");
1925         if ((ifp->if_flags & IFF_UP) != IFF_UP)
1926                 /* ignore silently */
1927                 return (0);
1928
1929         if (uio->uio_resid == 0)
1930                 return (0);
1931
1932         l2tun = (tp->tun_flags & TUN_L2) != 0;
1933         mru = l2tun ? TAPMRU : TUNMRU;
1934         vhdrlen = tp->tun_vhdrlen;
1935         align = 0;
1936         if (l2tun) {
1937                 align = ETHER_ALIGN;
1938                 mru += vhdrlen;
1939         } else if ((tp->tun_flags & TUN_IFHEAD) != 0)
1940                 mru += sizeof(uint32_t);        /* family */
1941         if (uio->uio_resid < 0 || uio->uio_resid > mru) {
1942                 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid);
1943                 return (EIO);
1944         }
1945
1946         if (vhdrlen > 0) {
1947                 error = uiomove(&vhdr, vhdrlen, uio);
1948                 if (error != 0)
1949                         return (error);
1950                 TUNDEBUG(ifp, "txvhdr: f %u, gt %u, hl %u, "
1951                     "gs %u, cs %u, co %u\n", vhdr.hdr.flags,
1952                     vhdr.hdr.gso_type, vhdr.hdr.hdr_len,
1953                     vhdr.hdr.gso_size, vhdr.hdr.csum_start,
1954                     vhdr.hdr.csum_offset);
1955         }
1956
1957         if ((m = m_uiotombuf(uio, M_NOWAIT, 0, align, M_PKTHDR)) == NULL) {
1958                 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
1959                 return (ENOBUFS);
1960         }
1961
1962         m->m_pkthdr.rcvif = ifp;
1963 #ifdef MAC
1964         mac_ifnet_create_mbuf(ifp, m);
1965 #endif
1966
1967         if (l2tun)
1968                 return (tunwrite_l2(tp, m, vhdrlen > 0 ? &vhdr : NULL));
1969
1970         return (tunwrite_l3(tp, m));
1971 }
1972
1973 /*
1974  * tunpoll - the poll interface, this is only useful on reads
1975  * really. The write detect always returns true, write never blocks
1976  * anyway, it either accepts the packet or drops it.
1977  */
1978 static  int
1979 tunpoll(struct cdev *dev, int events, struct thread *td)
1980 {
1981         struct tuntap_softc *tp = dev->si_drv1;
1982         struct ifnet    *ifp = TUN2IFP(tp);
1983         int             revents = 0;
1984
1985         TUNDEBUG(ifp, "tunpoll\n");
1986
1987         if (events & (POLLIN | POLLRDNORM)) {
1988                 IFQ_LOCK(&ifp->if_snd);
1989                 if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
1990                         TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len);
1991                         revents |= events & (POLLIN | POLLRDNORM);
1992                 } else {
1993                         TUNDEBUG(ifp, "tunpoll waiting\n");
1994                         selrecord(td, &tp->tun_rsel);
1995                 }
1996                 IFQ_UNLOCK(&ifp->if_snd);
1997         }
1998         revents |= events & (POLLOUT | POLLWRNORM);
1999
2000         return (revents);
2001 }
2002
2003 /*
2004  * tunkqfilter - support for the kevent() system call.
2005  */
2006 static int
2007 tunkqfilter(struct cdev *dev, struct knote *kn)
2008 {
2009         struct tuntap_softc     *tp = dev->si_drv1;
2010         struct ifnet    *ifp = TUN2IFP(tp);
2011
2012         switch(kn->kn_filter) {
2013         case EVFILT_READ:
2014                 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n",
2015                     ifp->if_xname, dev2unit(dev));
2016                 kn->kn_fop = &tun_read_filterops;
2017                 break;
2018
2019         case EVFILT_WRITE:
2020                 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n",
2021                     ifp->if_xname, dev2unit(dev));
2022                 kn->kn_fop = &tun_write_filterops;
2023                 break;
2024
2025         default:
2026                 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n",
2027                     ifp->if_xname, dev2unit(dev));
2028                 return(EINVAL);
2029         }
2030
2031         kn->kn_hook = tp;
2032         knlist_add(&tp->tun_rsel.si_note, kn, 0);
2033
2034         return (0);
2035 }
2036
2037 /*
2038  * Return true of there is data in the interface queue.
2039  */
2040 static int
2041 tunkqread(struct knote *kn, long hint)
2042 {
2043         int                     ret;
2044         struct tuntap_softc     *tp = kn->kn_hook;
2045         struct cdev             *dev = tp->tun_dev;
2046         struct ifnet    *ifp = TUN2IFP(tp);
2047
2048         if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) {
2049                 TUNDEBUG(ifp,
2050                     "%s have data in the queue.  Len = %d, minor = %#x\n",
2051                     ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev));
2052                 ret = 1;
2053         } else {
2054                 TUNDEBUG(ifp,
2055                     "%s waiting for data, minor = %#x\n", ifp->if_xname,
2056                     dev2unit(dev));
2057                 ret = 0;
2058         }
2059
2060         return (ret);
2061 }
2062
2063 /*
2064  * Always can write, always return MTU in kn->data.
2065  */
2066 static int
2067 tunkqwrite(struct knote *kn, long hint)
2068 {
2069         struct tuntap_softc     *tp = kn->kn_hook;
2070         struct ifnet    *ifp = TUN2IFP(tp);
2071
2072         kn->kn_data = ifp->if_mtu;
2073
2074         return (1);
2075 }
2076
2077 static void
2078 tunkqdetach(struct knote *kn)
2079 {
2080         struct tuntap_softc     *tp = kn->kn_hook;
2081
2082         knlist_remove(&tp->tun_rsel.si_note, kn, 0);
2083 }