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-FreeBSD
   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  * $FreeBSD$
  47  */
  48
  49 #include "opt_inet.h"
  50 #include "opt_inet6.h"
  51
  52 #include <sys/param.h>
  53 #include <sys/lock.h>
  54 #include <sys/priv.h>
  55 #include <sys/proc.h>
  56 #include <sys/systm.h>
  57 #include <sys/jail.h>
  58 #include <sys/mbuf.h>
  59 #include <sys/module.h>
  60 #include <sys/socket.h>
  61 #include <sys/eventhandler.h>
  62 #include <sys/fcntl.h>
  63 #include <sys/filio.h>
  64 #include <sys/sockio.h>
  65 #include <sys/sx.h>
  66 #include <sys/syslog.h>
  67 #include <sys/ttycom.h>
  68 #include <sys/poll.h>
  69 #include <sys/selinfo.h>
  70 #include <sys/signalvar.h>
  71 #include <sys/filedesc.h>
  72 #include <sys/kernel.h>
  73 #include <sys/sysctl.h>
  74 #include <sys/conf.h>
  75 #include <sys/uio.h>
  76 #include <sys/malloc.h>
  77 #include <sys/random.h>
  78 #include <sys/ctype.h>
  79
  80 #include <net/ethernet.h>
  81 #include <net/if.h>
  82 #include <net/if_var.h>
  83 #include <net/if_clone.h>
  84 #include <net/if_dl.h>
  85 #include <net/if_media.h>
  86 #include <net/if_types.h>
  87 #include <net/if_vlan_var.h>
  88 #include <net/netisr.h>
  89 #include <net/route.h>
  90 #include <net/vnet.h>
  91 #include <netinet/in.h>
  92 #ifdef INET
  93 #include <netinet/ip.h>
  94 #endif
  95 #ifdef INET6
  96 #include <netinet/ip6.h>
  97 #include <netinet6/ip6_var.h>
  98 #endif
  99 #include <netinet/udp.h>
 100 #include <netinet/tcp.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_DSTADDR     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 };
 149 #define TUN2IFP(sc)     ((sc)->tun_ifp)
 150
 151 #define TUNDEBUG        if (tundebug) if_printf
 152
 153 #define TUN_LOCK(tp)            mtx_lock(&(tp)->tun_mtx)
 154 #define TUN_UNLOCK(tp)          mtx_unlock(&(tp)->tun_mtx)
 155 #define TUN_LOCK_ASSERT(tp)     mtx_assert(&(tp)->tun_mtx, MA_OWNED);
 156
 157 #define TUN_VMIO_FLAG_MASK      0x0fff
 158
 159 /*
 160  * Interface capabilities of a tap device that supports the virtio-net
 161  * header.
 162  */
 163 #define TAP_VNET_HDR_CAPS       (IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6       \
 164                                 | IFCAP_VLAN_HWCSUM                     \
 165                                 | IFCAP_TSO | IFCAP_LRO                 \
 166                                 | IFCAP_VLAN_HWTSO)
 167
 168 #define TAP_ALL_OFFLOAD         (CSUM_TSO | CSUM_TCP | CSUM_UDP |\
 169                                     CSUM_TCP_IPV6 | CSUM_UDP_IPV6)
 170
 171
 172 /*
 173  * All mutable global variables in if_tun are locked using tunmtx, with
 174  * the exception of tundebug, which is used unlocked, and the drivers' *clones,
 175  * which are static after setup.
 176  */
 177 static struct mtx tunmtx;
 178 static eventhandler_tag arrival_tag;
 179 static eventhandler_tag clone_tag;
 180 static const char tunname[] = "tun";
 181 static const char tapname[] = "tap";
 182 static const char vmnetname[] = "vmnet";
 183 static MALLOC_DEFINE(M_TUN, tunname, "Tunnel Interface");
 184 static int tundebug = 0;
 185 static int tundclone = 1;
 186 static int tap_allow_uopen = 0; /* allow user devfs cloning */
 187 static int tapuponopen = 0;     /* IFF_UP on open() */
 188 static int tapdclone = 1;       /* enable devfs cloning */
 189
 190 static TAILQ_HEAD(,tuntap_softc)        tunhead = TAILQ_HEAD_INITIALIZER(tunhead);
 191 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");
 192
 193 static struct sx tun_ioctl_sx;
 194 SX_SYSINIT(tun_ioctl_sx, &tun_ioctl_sx, "tun_ioctl");
 195
 196 SYSCTL_DECL(_net_link);
 197 /* tun */
 198 static SYSCTL_NODE(_net_link, OID_AUTO, tun, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
 199     "IP tunnel software network interface");
 200 SYSCTL_INT(_net_link_tun, OID_AUTO, devfs_cloning, CTLFLAG_RWTUN, &tundclone, 0,
 201     "Enable legacy devfs interface creation");
 202
 203 /* tap */
 204 static SYSCTL_NODE(_net_link, OID_AUTO, tap, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
 205     "Ethernet tunnel software network interface");
 206 SYSCTL_INT(_net_link_tap, OID_AUTO, user_open, CTLFLAG_RW, &tap_allow_uopen, 0,
 207     "Enable legacy devfs interface creation for all users");
 208 SYSCTL_INT(_net_link_tap, OID_AUTO, up_on_open, CTLFLAG_RW, &tapuponopen, 0,
 209     "Bring interface up when /dev/tap is opened");
 210 SYSCTL_INT(_net_link_tap, OID_AUTO, devfs_cloning, CTLFLAG_RWTUN, &tapdclone, 0,
 211     "Enable legacy devfs interface creation");
 212 SYSCTL_INT(_net_link_tap, OID_AUTO, debug, CTLFLAG_RW, &tundebug, 0, "");
 213
 214 static int      tun_create_device(struct tuntap_driver *drv, int unit,
 215     struct ucred *cr, struct cdev **dev, const char *name);
 216 static int      tun_busy_locked(struct tuntap_softc *tp);
 217 static void     tun_unbusy_locked(struct tuntap_softc *tp);
 218 static int      tun_busy(struct tuntap_softc *tp);
 219 static void     tun_unbusy(struct tuntap_softc *tp);
 220
 221 static int      tuntap_name2info(const char *name, int *unit, int *flags);
 222 static void     tunclone(void *arg, struct ucred *cred, char *name,
 223                     int namelen, struct cdev **dev);
 224 static void     tuncreate(struct cdev *dev);
 225 static void     tundtor(void *data);
 226 static void     tunrename(void *arg, struct ifnet *ifp);
 227 static int      tunifioctl(struct ifnet *, u_long, caddr_t);
 228 static void     tuninit(struct ifnet *);
 229 static void     tunifinit(void *xtp);
 230 static int      tuntapmodevent(module_t, int, void *);
 231 static int      tunoutput(struct ifnet *, struct mbuf *,
 232                     const struct sockaddr *, struct route *ro);
 233 static void     tunstart(struct ifnet *);
 234 static void     tunstart_l2(struct ifnet *);
 235
 236 static int      tun_clone_match(struct if_clone *ifc, const char *name);
 237 static int      tap_clone_match(struct if_clone *ifc, const char *name);
 238 static int      vmnet_clone_match(struct if_clone *ifc, const char *name);
 239 static int      tun_clone_create(struct if_clone *, char *, size_t, caddr_t);
 240 static int      tun_clone_destroy(struct if_clone *, struct ifnet *);
 241 static void     tun_vnethdr_set(struct ifnet *ifp, int vhdrlen);
 242
 243 static d_open_t         tunopen;
 244 static d_read_t         tunread;
 245 static d_write_t        tunwrite;
 246 static d_ioctl_t        tunioctl;
 247 static d_poll_t         tunpoll;
 248 static d_kqfilter_t     tunkqfilter;
 249
 250 static int              tunkqread(struct knote *, long);
 251 static int              tunkqwrite(struct knote *, long);
 252 static void             tunkqdetach(struct knote *);
 253
 254 static struct filterops tun_read_filterops = {
 255         .f_isfd =       1,
 256         .f_attach =     NULL,
 257         .f_detach =     tunkqdetach,
 258         .f_event =      tunkqread,
 259 };
 260
 261 static struct filterops tun_write_filterops = {
 262         .f_isfd =       1,
 263         .f_attach =     NULL,
 264         .f_detach =     tunkqdetach,
 265         .f_event =      tunkqwrite,
 266 };
 267
 268 static struct tuntap_driver {
 269         struct cdevsw            cdevsw;
 270         int                      ident_flags;
 271         struct unrhdr           *unrhdr;
 272         struct clonedevs        *clones;
 273         ifc_match_t             *clone_match_fn;
 274         ifc_create_t            *clone_create_fn;
 275         ifc_destroy_t           *clone_destroy_fn;
 276 } tuntap_drivers[] = {
 277         {
 278                 .ident_flags =  0,
 279                 .cdevsw =       {
 280                     .d_version =        D_VERSION,
 281                     .d_flags =          D_NEEDMINOR,
 282                     .d_open =           tunopen,
 283                     .d_read =           tunread,
 284                     .d_write =          tunwrite,
 285                     .d_ioctl =          tunioctl,
 286                     .d_poll =           tunpoll,
 287                     .d_kqfilter =       tunkqfilter,
 288                     .d_name =           tunname,
 289                 },
 290                 .clone_match_fn =       tun_clone_match,
 291                 .clone_create_fn =      tun_clone_create,
 292                 .clone_destroy_fn =     tun_clone_destroy,
 293         },
 294         {
 295                 .ident_flags =  TUN_L2,
 296                 .cdevsw =       {
 297                     .d_version =        D_VERSION,
 298                     .d_flags =          D_NEEDMINOR,
 299                     .d_open =           tunopen,
 300                     .d_read =           tunread,
 301                     .d_write =          tunwrite,
 302                     .d_ioctl =          tunioctl,
 303                     .d_poll =           tunpoll,
 304                     .d_kqfilter =       tunkqfilter,
 305                     .d_name =           tapname,
 306                 },
 307                 .clone_match_fn =       tap_clone_match,
 308                 .clone_create_fn =      tun_clone_create,
 309                 .clone_destroy_fn =     tun_clone_destroy,
 310         },
 311         {
 312                 .ident_flags =  TUN_L2 | TUN_VMNET,
 313                 .cdevsw =       {
 314                     .d_version =        D_VERSION,
 315                     .d_flags =          D_NEEDMINOR,
 316                     .d_open =           tunopen,
 317                     .d_read =           tunread,
 318                     .d_write =          tunwrite,
 319                     .d_ioctl =          tunioctl,
 320                     .d_poll =           tunpoll,
 321                     .d_kqfilter =       tunkqfilter,
 322                     .d_name =           vmnetname,
 323                 },
 324                 .clone_match_fn =       vmnet_clone_match,
 325                 .clone_create_fn =      tun_clone_create,
 326                 .clone_destroy_fn =     tun_clone_destroy,
 327         },
 328 };
 329
 330 struct tuntap_driver_cloner {
 331         SLIST_ENTRY(tuntap_driver_cloner)        link;
 332         struct tuntap_driver                    *drv;
 333         struct if_clone                         *cloner;
 334 };
 335
 336 VNET_DEFINE_STATIC(SLIST_HEAD(, tuntap_driver_cloner), tuntap_driver_cloners) =
 337     SLIST_HEAD_INITIALIZER(tuntap_driver_cloners);
 338
 339 #define V_tuntap_driver_cloners VNET(tuntap_driver_cloners)
 340
 341 /*
 342  * Mechanism for marking a tunnel device as busy so that we can safely do some
 343  * orthogonal operations (such as operations on devices) without racing against
 344  * tun_destroy.  tun_destroy will wait on the condvar if we're at all busy or
 345  * open, to be woken up when the condition is alleviated.
 346  */
 347 static int
 348 tun_busy_locked(struct tuntap_softc *tp)
 349 {
 350
 351         TUN_LOCK_ASSERT(tp);
 352         if ((tp->tun_flags & TUN_DYING) != 0) {
 353                 /*
 354                  * Perhaps unintuitive, but the device is busy going away.
 355                  * Other interpretations of EBUSY from tun_busy make little
 356                  * sense, since making a busy device even more busy doesn't
 357                  * sound like a problem.
 358                  */
 359                 return (EBUSY);
 360         }
 361
 362         ++tp->tun_busy;
 363         return (0);
 364 }
 365
 366 static void
 367 tun_unbusy_locked(struct tuntap_softc *tp)
 368 {
 369
 370         TUN_LOCK_ASSERT(tp);
 371         KASSERT(tp->tun_busy != 0, ("tun_unbusy: called for non-busy tunnel"));
 372
 373         --tp->tun_busy;
 374         /* Wake up anything that may be waiting on our busy tunnel. */
 375         if (tp->tun_busy == 0)
 376                 cv_broadcast(&tp->tun_cv);
 377 }
 378
 379 static int
 380 tun_busy(struct tuntap_softc *tp)
 381 {
 382         int ret;
 383
 384         TUN_LOCK(tp);
 385         ret = tun_busy_locked(tp);
 386         TUN_UNLOCK(tp);
 387         return (ret);
 388 }
 389
 390
 391 static void
 392 tun_unbusy(struct tuntap_softc *tp)
 393 {
 394
 395         TUN_LOCK(tp);
 396         tun_unbusy_locked(tp);
 397         TUN_UNLOCK(tp);
 398 }
 399
 400 /*
 401  * Sets unit and/or flags given the device name.  Must be called with correct
 402  * vnet context.
 403  */
 404 static int
 405 tuntap_name2info(const char *name, int *outunit, int *outflags)
 406 {
 407         struct tuntap_driver *drv;
 408         struct tuntap_driver_cloner *drvc;
 409         char *dname;
 410         int flags, unit;
 411         bool found;
 412
 413         if (name == NULL)
 414                 return (EINVAL);
 415
 416         /*
 417          * Needed for dev_stdclone, but dev_stdclone will not modify, it just
 418          * wants to be able to pass back a char * through the second param. We
 419          * will always set that as NULL here, so we'll fake it.
 420          */
 421         dname = __DECONST(char *, name);
 422         found = false;
 423
 424         KASSERT(!SLIST_EMPTY(&V_tuntap_driver_cloners),
 425             ("tuntap_driver_cloners failed to initialize"));
 426         SLIST_FOREACH(drvc, &V_tuntap_driver_cloners, link) {
 427                 KASSERT(drvc->drv != NULL,
 428                     ("tuntap_driver_cloners entry not properly initialized"));
 429                 drv = drvc->drv;
 430
 431                 if (strcmp(name, drv->cdevsw.d_name) == 0) {
 432                         found = true;
 433                         unit = -1;
 434                         flags = drv->ident_flags;
 435                         break;
 436                 }
 437
 438                 if (dev_stdclone(dname, NULL, drv->cdevsw.d_name, &unit) == 1) {
 439                         found = true;
 440                         flags = drv->ident_flags;
 441                         break;
 442                 }
 443         }
 444
 445         if (!found)
 446                 return (ENXIO);
 447
 448         if (outunit != NULL)
 449                 *outunit = unit;
 450         if (outflags != NULL)
 451                 *outflags = flags;
 452         return (0);
 453 }
 454
 455 /*
 456  * Get driver information from a set of flags specified.  Masks the identifying
 457  * part of the flags and compares it against all of the available
 458  * tuntap_drivers. Must be called with correct vnet context.
 459  */
 460 static struct tuntap_driver *
 461 tuntap_driver_from_flags(int tun_flags)
 462 {
 463         struct tuntap_driver *drv;
 464         struct tuntap_driver_cloner *drvc;
 465
 466         KASSERT(!SLIST_EMPTY(&V_tuntap_driver_cloners),
 467             ("tuntap_driver_cloners failed to initialize"));
 468         SLIST_FOREACH(drvc, &V_tuntap_driver_cloners, link) {
 469                 KASSERT(drvc->drv != NULL,
 470                     ("tuntap_driver_cloners entry not properly initialized"));
 471                 drv = drvc->drv;
 472                 if ((tun_flags & TUN_DRIVER_IDENT_MASK) == drv->ident_flags)
 473                         return (drv);
 474         }
 475
 476         return (NULL);
 477 }
 478
 479
 480
 481 static int
 482 tun_clone_match(struct if_clone *ifc, const char *name)
 483 {
 484         int tunflags;
 485
 486         if (tuntap_name2info(name, NULL, &tunflags) == 0) {
 487                 if ((tunflags & TUN_L2) == 0)
 488                         return (1);
 489         }
 490
 491         return (0);
 492 }
 493
 494 static int
 495 tap_clone_match(struct if_clone *ifc, const char *name)
 496 {
 497         int tunflags;
 498
 499         if (tuntap_name2info(name, NULL, &tunflags) == 0) {
 500                 if ((tunflags & (TUN_L2 | TUN_VMNET)) == TUN_L2)
 501                         return (1);
 502         }
 503
 504         return (0);
 505 }
 506
 507 static int
 508 vmnet_clone_match(struct if_clone *ifc, const char *name)
 509 {
 510         int tunflags;
 511
 512         if (tuntap_name2info(name, NULL, &tunflags) == 0) {
 513                 if ((tunflags & TUN_VMNET) != 0)
 514                         return (1);
 515         }
 516
 517         return (0);
 518 }
 519
 520 static int
 521 tun_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
 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                 tuncreate(dev);
 555
 556         return (i);
 557 }
 558
 559 static void
 560 tunclone(void *arg, struct ucred *cred, char *name, int namelen,
 561     struct cdev **dev)
 562 {
 563         char devname[SPECNAMELEN + 1];
 564         struct tuntap_driver *drv;
 565         int append_unit, i, u, tunflags;
 566         bool mayclone;
 567
 568         if (*dev != NULL)
 569                 return;
 570
 571         tunflags = 0;
 572         CURVNET_SET(CRED_TO_VNET(cred));
 573         if (tuntap_name2info(name, &u, &tunflags) != 0)
 574                 goto out;       /* Not recognized */
 575
 576         if (u != -1 && u > IF_MAXUNIT)
 577                 goto out;       /* Unit number too high */
 578
 579         mayclone = priv_check_cred(cred, PRIV_NET_IFCREATE) == 0;
 580         if ((tunflags & TUN_L2) != 0) {
 581                 /* tap/vmnet allow user open with a sysctl */
 582                 mayclone = (mayclone || tap_allow_uopen) && tapdclone;
 583         } else {
 584                 mayclone = mayclone && tundclone;
 585         }
 586
 587         /*
 588          * If tun cloning is enabled, only the superuser can create an
 589          * interface.
 590          */
 591         if (!mayclone)
 592                 goto out;
 593
 594         if (u == -1)
 595                 append_unit = 1;
 596         else
 597                 append_unit = 0;
 598
 599         drv = tuntap_driver_from_flags(tunflags);
 600         if (drv == NULL)
 601                 goto out;
 602
 603         /* find any existing device, or allocate new unit number */
 604         i = clone_create(&drv->clones, &drv->cdevsw, &u, dev, 0);
 605         if (i) {
 606                 if (append_unit) {
 607                         namelen = snprintf(devname, sizeof(devname), "%s%d",
 608                             name, u);
 609                         name = devname;
 610                 }
 611
 612                 i = tun_create_device(drv, u, cred, dev, name);
 613         }
 614         if (i == 0)
 615                 if_clone_create(name, namelen, NULL);
 616 out:
 617         CURVNET_RESTORE();
 618 }
 619
 620 static void
 621 tun_destroy(struct tuntap_softc *tp)
 622 {
 623
 624         TUN_LOCK(tp);
 625         tp->tun_flags |= TUN_DYING;
 626         if (tp->tun_busy != 0)
 627                 cv_wait_unlock(&tp->tun_cv, &tp->tun_mtx);
 628         else
 629                 TUN_UNLOCK(tp);
 630
 631         CURVNET_SET(TUN2IFP(tp)->if_vnet);
 632
 633         /* destroy_dev will take care of any alias. */
 634         destroy_dev(tp->tun_dev);
 635         seldrain(&tp->tun_rsel);
 636         knlist_clear(&tp->tun_rsel.si_note, 0);
 637         knlist_destroy(&tp->tun_rsel.si_note);
 638         if ((tp->tun_flags & TUN_L2) != 0) {
 639                 ether_ifdetach(TUN2IFP(tp));
 640         } else {
 641                 bpfdetach(TUN2IFP(tp));
 642                 if_detach(TUN2IFP(tp));
 643         }
 644         sx_xlock(&tun_ioctl_sx);
 645         TUN2IFP(tp)->if_softc = NULL;
 646         sx_xunlock(&tun_ioctl_sx);
 647         free_unr(tp->tun_drv->unrhdr, TUN2IFP(tp)->if_dunit);
 648         if_free(TUN2IFP(tp));
 649         mtx_destroy(&tp->tun_mtx);
 650         cv_destroy(&tp->tun_cv);
 651         free(tp, M_TUN);
 652         CURVNET_RESTORE();
 653 }
 654
 655 static int
 656 tun_clone_destroy(struct if_clone *ifc __unused, struct ifnet *ifp)
 657 {
 658         struct tuntap_softc *tp = ifp->if_softc;
 659
 660         mtx_lock(&tunmtx);
 661         TAILQ_REMOVE(&tunhead, tp, tun_list);
 662         mtx_unlock(&tunmtx);
 663         tun_destroy(tp);
 664
 665         return (0);
 666 }
 667
 668 static void
 669 vnet_tun_init(const void *unused __unused)
 670 {
 671         struct tuntap_driver *drv;
 672         struct tuntap_driver_cloner *drvc;
 673         int i;
 674
 675         for (i = 0; i < nitems(tuntap_drivers); ++i) {
 676                 drv = &tuntap_drivers[i];
 677                 drvc = malloc(sizeof(*drvc), M_TUN, M_WAITOK | M_ZERO);
 678
 679                 drvc->drv = drv;
 680                 drvc->cloner = if_clone_advanced(drv->cdevsw.d_name, 0,
 681                     drv->clone_match_fn, drv->clone_create_fn,
 682                     drv->clone_destroy_fn);
 683                 SLIST_INSERT_HEAD(&V_tuntap_driver_cloners, drvc, link);
 684         };
 685 }
 686 VNET_SYSINIT(vnet_tun_init, SI_SUB_PROTO_IF, SI_ORDER_ANY,
 687                 vnet_tun_init, NULL);
 688
 689 static void
 690 vnet_tun_uninit(const void *unused __unused)
 691 {
 692         struct tuntap_driver_cloner *drvc;
 693
 694         while (!SLIST_EMPTY(&V_tuntap_driver_cloners)) {
 695                 drvc = SLIST_FIRST(&V_tuntap_driver_cloners);
 696                 SLIST_REMOVE_HEAD(&V_tuntap_driver_cloners, link);
 697
 698                 if_clone_detach(drvc->cloner);
 699                 free(drvc, M_TUN);
 700         }
 701 }
 702 VNET_SYSUNINIT(vnet_tun_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY,
 703     vnet_tun_uninit, NULL);
 704
 705 static void
 706 tun_uninit(const void *unused __unused)
 707 {
 708         struct tuntap_driver *drv;
 709         struct tuntap_softc *tp;
 710         int i;
 711
 712         EVENTHANDLER_DEREGISTER(ifnet_arrival_event, arrival_tag);
 713         EVENTHANDLER_DEREGISTER(dev_clone, clone_tag);
 714         drain_dev_clone_events();
 715
 716         mtx_lock(&tunmtx);
 717         while ((tp = TAILQ_FIRST(&tunhead)) != NULL) {
 718                 TAILQ_REMOVE(&tunhead, tp, tun_list);
 719                 mtx_unlock(&tunmtx);
 720                 tun_destroy(tp);
 721                 mtx_lock(&tunmtx);
 722         }
 723         mtx_unlock(&tunmtx);
 724         for (i = 0; i < nitems(tuntap_drivers); ++i) {
 725                 drv = &tuntap_drivers[i];
 726                 delete_unrhdr(drv->unrhdr);
 727                 clone_cleanup(&drv->clones);
 728         }
 729         mtx_destroy(&tunmtx);
 730 }
 731 SYSUNINIT(tun_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY, tun_uninit, NULL);
 732
 733 static struct tuntap_driver *
 734 tuntap_driver_from_ifnet(const struct ifnet *ifp)
 735 {
 736         struct tuntap_driver *drv;
 737         int i;
 738
 739         if (ifp == NULL)
 740                 return (NULL);
 741
 742         for (i = 0; i < nitems(tuntap_drivers); ++i) {
 743                 drv = &tuntap_drivers[i];
 744                 if (strcmp(ifp->if_dname, drv->cdevsw.d_name) == 0)
 745                         return (drv);
 746         }
 747
 748         return (NULL);
 749 }
 750
 751 static int
 752 tuntapmodevent(module_t mod, int type, void *data)
 753 {
 754         struct tuntap_driver *drv;
 755         int i;
 756
 757         switch (type) {
 758         case MOD_LOAD:
 759                 mtx_init(&tunmtx, "tunmtx", NULL, MTX_DEF);
 760                 for (i = 0; i < nitems(tuntap_drivers); ++i) {
 761                         drv = &tuntap_drivers[i];
 762                         clone_setup(&drv->clones);
 763                         drv->unrhdr = new_unrhdr(0, IF_MAXUNIT, &tunmtx);
 764                 }
 765                 arrival_tag = EVENTHANDLER_REGISTER(ifnet_arrival_event,
 766                    tunrename, 0, 1000);
 767                 if (arrival_tag == NULL)
 768                         return (ENOMEM);
 769                 clone_tag = EVENTHANDLER_REGISTER(dev_clone, tunclone, 0, 1000);
 770                 if (clone_tag == NULL)
 771                         return (ENOMEM);
 772                 break;
 773         case MOD_UNLOAD:
 774                 /* See tun_uninit, so it's done after the vnet_sysuninit() */
 775                 break;
 776         default:
 777                 return EOPNOTSUPP;
 778         }
 779         return 0;
 780 }
 781
 782 static moduledata_t tuntap_mod = {
 783         "if_tuntap",
 784         tuntapmodevent,
 785         0
 786 };
 787
 788 /* We'll only ever have these two, so no need for a macro. */
 789 static moduledata_t tun_mod = { "if_tun", NULL, 0 };
 790 static moduledata_t tap_mod = { "if_tap", NULL, 0 };
 791
 792 DECLARE_MODULE(if_tuntap, tuntap_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 793 MODULE_VERSION(if_tuntap, 1);
 794 DECLARE_MODULE(if_tun, tun_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 795 MODULE_VERSION(if_tun, 1);
 796 DECLARE_MODULE(if_tap, tap_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 797 MODULE_VERSION(if_tap, 1);
 798
 799 static int
 800 tun_create_device(struct tuntap_driver *drv, int unit, struct ucred *cr,
 801     struct cdev **dev, const char *name)
 802 {
 803         struct make_dev_args args;
 804         struct tuntap_softc *tp;
 805         int error;
 806
 807         tp = malloc(sizeof(*tp), M_TUN, M_WAITOK | M_ZERO);
 808         mtx_init(&tp->tun_mtx, "tun_mtx", NULL, MTX_DEF);
 809         cv_init(&tp->tun_cv, "tun_condvar");
 810         tp->tun_flags = drv->ident_flags;
 811         tp->tun_drv = drv;
 812
 813         make_dev_args_init(&args);
 814         if (cr != NULL)
 815                 args.mda_flags = MAKEDEV_REF;
 816         args.mda_devsw = &drv->cdevsw;
 817         args.mda_cr = cr;
 818         args.mda_uid = UID_UUCP;
 819         args.mda_gid = GID_DIALER;
 820         args.mda_mode = 0600;
 821         args.mda_unit = unit;
 822         args.mda_si_drv1 = tp;
 823         error = make_dev_s(&args, dev, "%s", name);
 824         if (error != 0) {
 825                 free(tp, M_TUN);
 826                 return (error);
 827         }
 828
 829         KASSERT((*dev)->si_drv1 != NULL,
 830             ("Failed to set si_drv1 at %s creation", name));
 831         tp->tun_dev = *dev;
 832         knlist_init_mtx(&tp->tun_rsel.si_note, &tp->tun_mtx);
 833         mtx_lock(&tunmtx);
 834         TAILQ_INSERT_TAIL(&tunhead, tp, tun_list);
 835         mtx_unlock(&tunmtx);
 836         return (0);
 837 }
 838
 839 static void
 840 tunstart(struct ifnet *ifp)
 841 {
 842         struct tuntap_softc *tp = ifp->if_softc;
 843         struct mbuf *m;
 844
 845         TUNDEBUG(ifp, "starting\n");
 846         if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
 847                 IFQ_LOCK(&ifp->if_snd);
 848                 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
 849                 if (m == NULL) {
 850                         IFQ_UNLOCK(&ifp->if_snd);
 851                         return;
 852                 }
 853                 IFQ_UNLOCK(&ifp->if_snd);
 854         }
 855
 856         TUN_LOCK(tp);
 857         if (tp->tun_flags & TUN_RWAIT) {
 858                 tp->tun_flags &= ~TUN_RWAIT;
 859                 wakeup(tp);
 860         }
 861         selwakeuppri(&tp->tun_rsel, PZERO + 1);
 862         KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
 863         if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio) {
 864                 TUN_UNLOCK(tp);
 865                 pgsigio(&tp->tun_sigio, SIGIO, 0);
 866         } else
 867                 TUN_UNLOCK(tp);
 868 }
 869
 870 /*
 871  * tunstart_l2
 872  *
 873  * queue packets from higher level ready to put out
 874  */
 875 static void
 876 tunstart_l2(struct ifnet *ifp)
 877 {
 878         struct tuntap_softc     *tp = ifp->if_softc;
 879
 880         TUNDEBUG(ifp, "starting\n");
 881
 882         /*
 883          * do not junk pending output if we are in VMnet mode.
 884          * XXX: can this do any harm because of queue overflow?
 885          */
 886
 887         TUN_LOCK(tp);
 888         if (((tp->tun_flags & TUN_VMNET) == 0) &&
 889             ((tp->tun_flags & TUN_READY) != TUN_READY)) {
 890                 struct mbuf *m;
 891
 892                 /* Unlocked read. */
 893                 TUNDEBUG(ifp, "not ready, tun_flags = 0x%x\n", tp->tun_flags);
 894
 895                 for (;;) {
 896                         IF_DEQUEUE(&ifp->if_snd, m);
 897                         if (m != NULL) {
 898                                 m_freem(m);
 899                                 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
 900                         } else
 901                                 break;
 902                 }
 903                 TUN_UNLOCK(tp);
 904
 905                 return;
 906         }
 907
 908         ifp->if_drv_flags |= IFF_DRV_OACTIVE;
 909
 910         if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
 911                 if (tp->tun_flags & TUN_RWAIT) {
 912                         tp->tun_flags &= ~TUN_RWAIT;
 913                         wakeup(tp);
 914                 }
 915
 916                 if ((tp->tun_flags & TUN_ASYNC) && (tp->tun_sigio != NULL)) {
 917                         TUN_UNLOCK(tp);
 918                         pgsigio(&tp->tun_sigio, SIGIO, 0);
 919                         TUN_LOCK(tp);
 920                 }
 921
 922                 selwakeuppri(&tp->tun_rsel, PZERO+1);
 923                 KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
 924                 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); /* obytes are counted in ether_output */
 925         }
 926
 927         ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
 928         TUN_UNLOCK(tp);
 929 } /* tunstart_l2 */
 930
 931 /* XXX: should return an error code so it can fail. */
 932 static void
 933 tuncreate(struct cdev *dev)
 934 {
 935         struct tuntap_driver *drv;
 936         struct tuntap_softc *tp;
 937         struct ifnet *ifp;
 938         struct ether_addr eaddr;
 939         int iflags;
 940         u_char type;
 941
 942         tp = dev->si_drv1;
 943         KASSERT(tp != NULL,
 944             ("si_drv1 should have been initialized at creation"));
 945
 946         drv = tp->tun_drv;
 947         iflags = IFF_MULTICAST;
 948         if ((tp->tun_flags & TUN_L2) != 0) {
 949                 type = IFT_ETHER;
 950                 iflags |= IFF_BROADCAST | IFF_SIMPLEX;
 951         } else {
 952                 type = IFT_PPP;
 953                 iflags |= IFF_POINTOPOINT;
 954         }
 955         ifp = tp->tun_ifp = if_alloc(type);
 956         if (ifp == NULL)
 957                 panic("%s%d: failed to if_alloc() interface.\n",
 958                     drv->cdevsw.d_name, dev2unit(dev));
 959         ifp->if_softc = tp;
 960         if_initname(ifp, drv->cdevsw.d_name, dev2unit(dev));
 961         ifp->if_ioctl = tunifioctl;
 962         ifp->if_flags = iflags;
 963         IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
 964         ifp->if_capabilities |= IFCAP_LINKSTATE;
 965         ifp->if_capenable |= IFCAP_LINKSTATE;
 966
 967         if ((tp->tun_flags & TUN_L2) != 0) {
 968                 ifp->if_init = tunifinit;
 969                 ifp->if_start = tunstart_l2;
 970
 971                 ether_gen_addr(ifp, &eaddr);
 972                 ether_ifattach(ifp, eaddr.octet);
 973         } else {
 974                 ifp->if_mtu = TUNMTU;
 975                 ifp->if_start = tunstart;
 976                 ifp->if_output = tunoutput;
 977
 978                 ifp->if_snd.ifq_drv_maxlen = 0;
 979                 IFQ_SET_READY(&ifp->if_snd);
 980
 981                 if_attach(ifp);
 982                 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
 983         }
 984
 985         TUN_LOCK(tp);
 986         tp->tun_flags |= TUN_INITED;
 987         TUN_UNLOCK(tp);
 988
 989         TUNDEBUG(ifp, "interface %s is created, minor = %#x\n",
 990             ifp->if_xname, dev2unit(dev));
 991 }
 992
 993 static void
 994 tunrename(void *arg __unused, struct ifnet *ifp)
 995 {
 996         struct tuntap_softc *tp;
 997         int error;
 998
 999         if ((ifp->if_flags & IFF_RENAMING) == 0)
1000                 return;
1001
1002         if (tuntap_driver_from_ifnet(ifp) == NULL)
1003                 return;
1004
1005         /*
1006          * We need to grab the ioctl sx long enough to make sure the softc is
1007          * still there.  If it is, we can safely try to busy the tun device.
1008          * The busy may fail if the device is currently dying, in which case
1009          * we do nothing.  If it doesn't fail, the busy count stops the device
1010          * from dying until we've created the alias (that will then be
1011          * subsequently destroyed).
1012          */
1013         sx_xlock(&tun_ioctl_sx);
1014         tp = ifp->if_softc;
1015         if (tp == NULL) {
1016                 sx_xunlock(&tun_ioctl_sx);
1017                 return;
1018         }
1019         error = tun_busy(tp);
1020         sx_xunlock(&tun_ioctl_sx);
1021         if (error != 0)
1022                 return;
1023         if (tp->tun_alias != NULL) {
1024                 destroy_dev(tp->tun_alias);
1025                 tp->tun_alias = NULL;
1026         }
1027
1028         if (strcmp(ifp->if_xname, tp->tun_dev->si_name) == 0)
1029                 goto out;
1030
1031         /*
1032          * Failure's ok, aliases are created on a best effort basis.  If a
1033          * tun user/consumer decides to rename the interface to conflict with
1034          * another device (non-ifnet) on the system, we will assume they know
1035          * what they are doing.  make_dev_alias_p won't touch tun_alias on
1036          * failure, so we use it but ignore the return value.
1037          */
1038         make_dev_alias_p(MAKEDEV_CHECKNAME, &tp->tun_alias, tp->tun_dev, "%s",
1039             ifp->if_xname);
1040 out:
1041         tun_unbusy(tp);
1042 }
1043
1044 static int
1045 tunopen(struct cdev *dev, int flag, int mode, struct thread *td)
1046 {
1047         struct ifnet    *ifp;
1048         struct tuntap_softc *tp;
1049         int error, tunflags;
1050
1051         tunflags = 0;
1052         CURVNET_SET(TD_TO_VNET(td));
1053         error = tuntap_name2info(dev->si_name, NULL, &tunflags);
1054         if (error != 0) {
1055                 CURVNET_RESTORE();
1056                 return (error); /* Shouldn't happen */
1057         }
1058
1059         tp = dev->si_drv1;
1060         KASSERT(tp != NULL,
1061             ("si_drv1 should have been initialized at creation"));
1062
1063         TUN_LOCK(tp);
1064         if ((tp->tun_flags & TUN_INITED) == 0) {
1065                 TUN_UNLOCK(tp);
1066                 CURVNET_RESTORE();
1067                 return (ENXIO);
1068         }
1069         if ((tp->tun_flags & (TUN_OPEN | TUN_DYING)) != 0) {
1070                 TUN_UNLOCK(tp);
1071                 CURVNET_RESTORE();
1072                 return (EBUSY);
1073         }
1074
1075         error = tun_busy_locked(tp);
1076         KASSERT(error == 0, ("Must be able to busy an unopen tunnel"));
1077         ifp = TUN2IFP(tp);
1078
1079         if ((tp->tun_flags & TUN_L2) != 0) {
1080                 bcopy(IF_LLADDR(ifp), tp->tun_ether.octet,
1081                     sizeof(tp->tun_ether.octet));
1082
1083                 ifp->if_drv_flags |= IFF_DRV_RUNNING;
1084                 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1085
1086                 if (tapuponopen)
1087                         ifp->if_flags |= IFF_UP;
1088         }
1089
1090         tp->tun_pid = td->td_proc->p_pid;
1091         tp->tun_flags |= TUN_OPEN;
1092
1093         if_link_state_change(ifp, LINK_STATE_UP);
1094         TUNDEBUG(ifp, "open\n");
1095         TUN_UNLOCK(tp);
1096
1097         /*
1098          * This can fail with either ENOENT or EBUSY.  This is in the middle of
1099          * d_open, so ENOENT should not be possible.  EBUSY is possible, but
1100          * the only cdevpriv dtor being set will be tundtor and the softc being
1101          * passed is constant for a given cdev.  We ignore the possible error
1102          * because of this as either "unlikely" or "not actually a problem."
1103          */
1104         (void)devfs_set_cdevpriv(tp, tundtor);
1105         CURVNET_RESTORE();
1106         return (0);
1107 }
1108
1109 /*
1110  * tundtor - tear down the device - mark i/f down & delete
1111  * routing info
1112  */
1113 static void
1114 tundtor(void *data)
1115 {
1116         struct proc *p;
1117         struct tuntap_softc *tp;
1118         struct ifnet *ifp;
1119         bool l2tun;
1120
1121         tp = data;
1122         p = curproc;
1123         ifp = TUN2IFP(tp);
1124
1125         TUN_LOCK(tp);
1126
1127         /*
1128          * Realistically, we can't be obstinate here.  This only means that the
1129          * tuntap device was closed out of order, and the last closer wasn't the
1130          * controller.  These are still good to know about, though, as software
1131          * should avoid multiple processes with a tuntap device open and
1132          * ill-defined transfer of control (e.g., handoff, TUNSIFPID, close in
1133          * parent).
1134          */
1135         if (p->p_pid != tp->tun_pid) {
1136                 log(LOG_INFO,
1137                     "pid %d (%s), %s: tun/tap protocol violation, non-controlling process closed last.\n",
1138                     p->p_pid, p->p_comm, tp->tun_dev->si_name);
1139         }
1140
1141         /*
1142          * junk all pending output
1143          */
1144         CURVNET_SET(ifp->if_vnet);
1145
1146         l2tun = false;
1147         if ((tp->tun_flags & TUN_L2) != 0) {
1148                 l2tun = true;
1149                 IF_DRAIN(&ifp->if_snd);
1150         } else {
1151                 IFQ_PURGE(&ifp->if_snd);
1152         }
1153
1154         /* For vmnet, we won't do most of the address/route bits */
1155         if ((tp->tun_flags & TUN_VMNET) != 0 ||
1156             (l2tun && (ifp->if_flags & IFF_LINK0) != 0))
1157                 goto out;
1158
1159         if (ifp->if_flags & IFF_UP) {
1160                 TUN_UNLOCK(tp);
1161                 if_down(ifp);
1162                 TUN_LOCK(tp);
1163         }
1164
1165         /* Delete all addresses and routes which reference this interface. */
1166         if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
1167                 struct ifaddr *ifa;
1168
1169                 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1170                 TUN_UNLOCK(tp);
1171                 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1172                         /* deal w/IPv4 PtP destination; unlocked read */
1173                         if (!l2tun && ifa->ifa_addr->sa_family == AF_INET) {
1174                                 rtinit(ifa, (int)RTM_DELETE,
1175                                     tp->tun_flags & TUN_DSTADDR ? RTF_HOST : 0);
1176                         } else {
1177                                 rtinit(ifa, (int)RTM_DELETE, 0);
1178                         }
1179                 }
1180                 if_purgeaddrs(ifp);
1181                 TUN_LOCK(tp);
1182         }
1183
1184 out:
1185         if_link_state_change(ifp, LINK_STATE_DOWN);
1186         CURVNET_RESTORE();
1187
1188         funsetown(&tp->tun_sigio);
1189         selwakeuppri(&tp->tun_rsel, PZERO + 1);
1190         KNOTE_LOCKED(&tp->tun_rsel.si_note, 0);
1191         TUNDEBUG (ifp, "closed\n");
1192         tp->tun_flags &= ~TUN_OPEN;
1193         tp->tun_pid = 0;
1194         tun_vnethdr_set(ifp, 0);
1195
1196         tun_unbusy_locked(tp);
1197         TUN_UNLOCK(tp);
1198 }
1199
1200 static void
1201 tuninit(struct ifnet *ifp)
1202 {
1203         struct tuntap_softc *tp = ifp->if_softc;
1204 #ifdef INET
1205         struct epoch_tracker et;
1206         struct ifaddr *ifa;
1207 #endif
1208
1209         TUNDEBUG(ifp, "tuninit\n");
1210
1211         TUN_LOCK(tp);
1212         ifp->if_drv_flags |= IFF_DRV_RUNNING;
1213         if ((tp->tun_flags & TUN_L2) == 0) {
1214                 ifp->if_flags |= IFF_UP;
1215                 getmicrotime(&ifp->if_lastchange);
1216 #ifdef INET
1217                 NET_EPOCH_ENTER(et);
1218                 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1219                         if (ifa->ifa_addr->sa_family == AF_INET) {
1220                                 struct sockaddr_in *si;
1221
1222                                 si = (struct sockaddr_in *)ifa->ifa_dstaddr;
1223                                 if (si && si->sin_addr.s_addr) {
1224                                         tp->tun_flags |= TUN_DSTADDR;
1225                                         break;
1226                                 }
1227                         }
1228                 }
1229                 NET_EPOCH_EXIT(et);
1230 #endif
1231                 TUN_UNLOCK(tp);
1232         } else {
1233                 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1234                 TUN_UNLOCK(tp);
1235                 /* attempt to start output */
1236                 tunstart_l2(ifp);
1237         }
1238
1239 }
1240
1241 /*
1242  * Used only for l2 tunnel.
1243  */
1244 static void
1245 tunifinit(void *xtp)
1246 {
1247         struct tuntap_softc *tp;
1248
1249         tp = (struct tuntap_softc *)xtp;
1250         tuninit(tp->tun_ifp);
1251 }
1252
1253 /*
1254  * To be called under TUN_LOCK. Update ifp->if_hwassist according to the
1255  * current value of ifp->if_capenable.
1256  */
1257 static void
1258 tun_caps_changed(struct ifnet *ifp)
1259 {
1260         uint64_t hwassist = 0;
1261
1262         TUN_LOCK_ASSERT((struct tuntap_softc *)ifp->if_softc);
1263         if (ifp->if_capenable & IFCAP_TXCSUM)
1264                 hwassist |= CSUM_TCP | CSUM_UDP;
1265         if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
1266                 hwassist |= CSUM_TCP_IPV6
1267                     | CSUM_UDP_IPV6;
1268         if (ifp->if_capenable & IFCAP_TSO4)
1269                 hwassist |= CSUM_IP_TSO;
1270         if (ifp->if_capenable & IFCAP_TSO6)
1271                 hwassist |= CSUM_IP6_TSO;
1272         ifp->if_hwassist = hwassist;
1273 }
1274
1275 /*
1276  * To be called under TUN_LOCK. Update tp->tun_vhdrlen and adjust
1277  * if_capabilities and if_capenable as needed.
1278  */
1279 static void
1280 tun_vnethdr_set(struct ifnet *ifp, int vhdrlen)
1281 {
1282         struct tuntap_softc *tp = ifp->if_softc;
1283
1284         TUN_LOCK_ASSERT(tp);
1285
1286         if (tp->tun_vhdrlen == vhdrlen)
1287                 return;
1288
1289         /*
1290          * Update if_capabilities to reflect the
1291          * functionalities offered by the virtio-net
1292          * header.
1293          */
1294         if (vhdrlen != 0)
1295                 ifp->if_capabilities |=
1296                         TAP_VNET_HDR_CAPS;
1297         else
1298                 ifp->if_capabilities &=
1299                         ~TAP_VNET_HDR_CAPS;
1300         /*
1301          * Disable any capabilities that we don't
1302          * support anymore.
1303          */
1304         ifp->if_capenable &= ifp->if_capabilities;
1305         tun_caps_changed(ifp);
1306         tp->tun_vhdrlen = vhdrlen;
1307
1308         TUNDEBUG(ifp, "vnet_hdr_len=%d, if_capabilities=%x\n",
1309             vhdrlen, ifp->if_capabilities);
1310 }
1311
1312 /*
1313  * Process an ioctl request.
1314  */
1315 static int
1316 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1317 {
1318         struct ifreq *ifr = (struct ifreq *)data;
1319         struct tuntap_softc *tp;
1320         struct ifstat *ifs;
1321         struct ifmediareq       *ifmr;
1322         int             dummy, error = 0;
1323         bool            l2tun;
1324
1325         ifmr = NULL;
1326         sx_xlock(&tun_ioctl_sx);
1327         tp = ifp->if_softc;
1328         if (tp == NULL) {
1329                 error = ENXIO;
1330                 goto bad;
1331         }
1332         l2tun = (tp->tun_flags & TUN_L2) != 0;
1333         switch(cmd) {
1334         case SIOCGIFSTATUS:
1335                 ifs = (struct ifstat *)data;
1336                 TUN_LOCK(tp);
1337                 if (tp->tun_pid)
1338                         snprintf(ifs->ascii, sizeof(ifs->ascii),
1339                             "\tOpened by PID %d\n", tp->tun_pid);
1340                 else
1341                         ifs->ascii[0] = '\0';
1342                 TUN_UNLOCK(tp);
1343                 break;
1344         case SIOCSIFADDR:
1345                 if (l2tun)
1346                         error = ether_ioctl(ifp, cmd, data);
1347                 else
1348                         tuninit(ifp);
1349                 if (error == 0)
1350                     TUNDEBUG(ifp, "address set\n");
1351                 break;
1352         case SIOCSIFMTU:
1353                 ifp->if_mtu = ifr->ifr_mtu;
1354                 TUNDEBUG(ifp, "mtu set\n");
1355                 break;
1356         case SIOCSIFFLAGS:
1357         case SIOCADDMULTI:
1358         case SIOCDELMULTI:
1359                 break;
1360         case SIOCGIFMEDIA:
1361                 if (!l2tun) {
1362                         error = EINVAL;
1363                         break;
1364                 }
1365
1366                 ifmr = (struct ifmediareq *)data;
1367                 dummy = ifmr->ifm_count;
1368                 ifmr->ifm_count = 1;
1369                 ifmr->ifm_status = IFM_AVALID;
1370                 ifmr->ifm_active = IFM_ETHER;
1371                 if (tp->tun_flags & TUN_OPEN)
1372                         ifmr->ifm_status |= IFM_ACTIVE;
1373                 ifmr->ifm_current = ifmr->ifm_active;
1374                 if (dummy >= 1) {
1375                         int media = IFM_ETHER;
1376                         error = copyout(&media, ifmr->ifm_ulist, sizeof(int));
1377                 }
1378                 break;
1379         case SIOCSIFCAP:
1380                 TUN_LOCK(tp);
1381                 ifp->if_capenable = ifr->ifr_reqcap;
1382                 tun_caps_changed(ifp);
1383                 TUN_UNLOCK(tp);
1384                 VLAN_CAPABILITIES(ifp);
1385                 break;
1386         default:
1387                 if (l2tun) {
1388                         error = ether_ioctl(ifp, cmd, data);
1389                 } else {
1390                         error = EINVAL;
1391                 }
1392         }
1393 bad:
1394         sx_xunlock(&tun_ioctl_sx);
1395         return (error);
1396 }
1397
1398 /*
1399  * tunoutput - queue packets from higher level ready to put out.
1400  */
1401 static int
1402 tunoutput(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
1403     struct route *ro)
1404 {
1405         struct tuntap_softc *tp = ifp->if_softc;
1406         u_short cached_tun_flags;
1407         int error;
1408         u_int32_t af;
1409
1410         TUNDEBUG (ifp, "tunoutput\n");
1411
1412 #ifdef MAC
1413         error = mac_ifnet_check_transmit(ifp, m0);
1414         if (error) {
1415                 m_freem(m0);
1416                 return (error);
1417         }
1418 #endif
1419
1420         /* Could be unlocked read? */
1421         TUN_LOCK(tp);
1422         cached_tun_flags = tp->tun_flags;
1423         TUN_UNLOCK(tp);
1424         if ((cached_tun_flags & TUN_READY) != TUN_READY) {
1425                 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
1426                 m_freem (m0);
1427                 return (EHOSTDOWN);
1428         }
1429
1430         if ((ifp->if_flags & IFF_UP) != IFF_UP) {
1431                 m_freem (m0);
1432                 return (EHOSTDOWN);
1433         }
1434
1435         /* BPF writes need to be handled specially. */
1436         if (dst->sa_family == AF_UNSPEC)
1437                 bcopy(dst->sa_data, &af, sizeof(af));
1438         else
1439                 af = dst->sa_family;
1440
1441         if (bpf_peers_present(ifp->if_bpf))
1442                 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m0);
1443
1444         /* prepend sockaddr? this may abort if the mbuf allocation fails */
1445         if (cached_tun_flags & TUN_LMODE) {
1446                 /* allocate space for sockaddr */
1447                 M_PREPEND(m0, dst->sa_len, M_NOWAIT);
1448
1449                 /* if allocation failed drop packet */
1450                 if (m0 == NULL) {
1451                         if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1452                         if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1453                         return (ENOBUFS);
1454                 } else {
1455                         bcopy(dst, m0->m_data, dst->sa_len);
1456                 }
1457         }
1458
1459         if (cached_tun_flags & TUN_IFHEAD) {
1460                 /* Prepend the address family */
1461                 M_PREPEND(m0, 4, M_NOWAIT);
1462
1463                 /* if allocation failed drop packet */
1464                 if (m0 == NULL) {
1465                         if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
1466                         if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
1467                         return (ENOBUFS);
1468                 } else
1469                         *(u_int32_t *)m0->m_data = htonl(af);
1470         } else {
1471 #ifdef INET
1472                 if (af != AF_INET)
1473 #endif
1474                 {
1475                         m_freem(m0);
1476                         return (EAFNOSUPPORT);
1477                 }
1478         }
1479
1480         error = (ifp->if_transmit)(ifp, m0);
1481         if (error)
1482                 return (ENOBUFS);
1483         if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
1484         return (0);
1485 }
1486
1487 /*
1488  * the cdevsw interface is now pretty minimal.
1489  */
1490 static  int
1491 tunioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag,
1492     struct thread *td)
1493 {
1494         struct ifreq ifr, *ifrp;
1495         struct tuntap_softc *tp = dev->si_drv1;
1496         struct ifnet *ifp = TUN2IFP(tp);
1497         struct tuninfo *tunp;
1498         int error, iflags, ival;
1499         bool    l2tun;
1500
1501         l2tun = (tp->tun_flags & TUN_L2) != 0;
1502         if (l2tun) {
1503                 /* tap specific ioctls */
1504                 switch(cmd) {
1505                 /* VMware/VMnet port ioctl's */
1506 #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
1507     defined(COMPAT_FREEBSD4)
1508                 case _IO('V', 0):
1509                         ival = IOCPARM_IVAL(data);
1510                         data = (caddr_t)&ival;
1511                         /* FALLTHROUGH */
1512 #endif
1513                 case VMIO_SIOCSIFFLAGS: /* VMware/VMnet SIOCSIFFLAGS */
1514                         iflags = *(int *)data;
1515                         iflags &= TUN_VMIO_FLAG_MASK;
1516                         iflags &= ~IFF_CANTCHANGE;
1517                         iflags |= IFF_UP;
1518
1519                         TUN_LOCK(tp);
1520                         ifp->if_flags = iflags |
1521                             (ifp->if_flags & IFF_CANTCHANGE);
1522                         TUN_UNLOCK(tp);
1523
1524                         return (0);
1525                 case SIOCGIFADDR:       /* get MAC address of the remote side */
1526                         TUN_LOCK(tp);
1527                         bcopy(&tp->tun_ether.octet, data,
1528                             sizeof(tp->tun_ether.octet));
1529                         TUN_UNLOCK(tp);
1530
1531                         return (0);
1532                 case SIOCSIFADDR:       /* set MAC address of the remote side */
1533                         TUN_LOCK(tp);
1534                         bcopy(data, &tp->tun_ether.octet,
1535                             sizeof(tp->tun_ether.octet));
1536                         TUN_UNLOCK(tp);
1537
1538                         return (0);
1539                 case TAPSVNETHDR:
1540                         ival = *(int *)data;
1541                         if (ival != 0 &&
1542                             ival != sizeof(struct virtio_net_hdr) &&
1543                             ival != sizeof(struct virtio_net_hdr_mrg_rxbuf)) {
1544                                 return (EINVAL);
1545                         }
1546                         TUN_LOCK(tp);
1547                         tun_vnethdr_set(ifp, ival);
1548                         TUN_UNLOCK(tp);
1549
1550                         return (0);
1551                 case TAPGVNETHDR:
1552                         TUN_LOCK(tp);
1553                         *(int *)data = tp->tun_vhdrlen;
1554                         TUN_UNLOCK(tp);
1555
1556                         return (0);
1557                 }
1558
1559                 /* Fall through to the common ioctls if unhandled */
1560         } else {
1561                 switch (cmd) {
1562                 case TUNSLMODE:
1563                         TUN_LOCK(tp);
1564                         if (*(int *)data) {
1565                                 tp->tun_flags |= TUN_LMODE;
1566                                 tp->tun_flags &= ~TUN_IFHEAD;
1567                         } else
1568                                 tp->tun_flags &= ~TUN_LMODE;
1569                         TUN_UNLOCK(tp);
1570
1571                         return (0);
1572                 case TUNSIFHEAD:
1573                         TUN_LOCK(tp);
1574                         if (*(int *)data) {
1575                                 tp->tun_flags |= TUN_IFHEAD;
1576                                 tp->tun_flags &= ~TUN_LMODE;
1577                         } else
1578                                 tp->tun_flags &= ~TUN_IFHEAD;
1579                         TUN_UNLOCK(tp);
1580
1581                         return (0);
1582                 case TUNGIFHEAD:
1583                         TUN_LOCK(tp);
1584                         *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
1585                         TUN_UNLOCK(tp);
1586
1587                         return (0);
1588                 case TUNSIFMODE:
1589                         /* deny this if UP */
1590                         if (TUN2IFP(tp)->if_flags & IFF_UP)
1591                                 return (EBUSY);
1592
1593                         switch (*(int *)data & ~IFF_MULTICAST) {
1594                         case IFF_POINTOPOINT:
1595                         case IFF_BROADCAST:
1596                                 TUN_LOCK(tp);
1597                                 TUN2IFP(tp)->if_flags &=
1598                                     ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST);
1599                                 TUN2IFP(tp)->if_flags |= *(int *)data;
1600                                 TUN_UNLOCK(tp);
1601
1602                                 break;
1603                         default:
1604                                 return (EINVAL);
1605                         }
1606
1607                         return (0);
1608                 case TUNSIFPID:
1609                         TUN_LOCK(tp);
1610                         tp->tun_pid = curthread->td_proc->p_pid;
1611                         TUN_UNLOCK(tp);
1612
1613                         return (0);
1614                 }
1615                 /* Fall through to the common ioctls if unhandled */
1616         }
1617
1618         switch (cmd) {
1619         case TUNGIFNAME:
1620                 ifrp = (struct ifreq *)data;
1621                 strlcpy(ifrp->ifr_name, TUN2IFP(tp)->if_xname, IFNAMSIZ);
1622
1623                 return (0);
1624         case TUNSIFINFO:
1625                 tunp = (struct tuninfo *)data;
1626                 if (TUN2IFP(tp)->if_type != tunp->type)
1627                         return (EPROTOTYPE);
1628                 TUN_LOCK(tp);
1629                 if (TUN2IFP(tp)->if_mtu != tunp->mtu) {
1630                         strlcpy(ifr.ifr_name, if_name(TUN2IFP(tp)), IFNAMSIZ);
1631                         ifr.ifr_mtu = tunp->mtu;
1632                         CURVNET_SET(TUN2IFP(tp)->if_vnet);
1633                         error = ifhwioctl(SIOCSIFMTU, TUN2IFP(tp),
1634                             (caddr_t)&ifr, td);
1635                         CURVNET_RESTORE();
1636                         if (error) {
1637                                 TUN_UNLOCK(tp);
1638                                 return (error);
1639                         }
1640                 }
1641                 TUN2IFP(tp)->if_baudrate = tunp->baudrate;
1642                 TUN_UNLOCK(tp);
1643                 break;
1644         case TUNGIFINFO:
1645                 tunp = (struct tuninfo *)data;
1646                 TUN_LOCK(tp);
1647                 tunp->mtu = TUN2IFP(tp)->if_mtu;
1648                 tunp->type = TUN2IFP(tp)->if_type;
1649                 tunp->baudrate = TUN2IFP(tp)->if_baudrate;
1650                 TUN_UNLOCK(tp);
1651                 break;
1652         case TUNSDEBUG:
1653                 tundebug = *(int *)data;
1654                 break;
1655         case TUNGDEBUG:
1656                 *(int *)data = tundebug;
1657                 break;
1658         case FIONBIO:
1659                 break;
1660         case FIOASYNC:
1661                 TUN_LOCK(tp);
1662                 if (*(int *)data)
1663                         tp->tun_flags |= TUN_ASYNC;
1664                 else
1665                         tp->tun_flags &= ~TUN_ASYNC;
1666                 TUN_UNLOCK(tp);
1667                 break;
1668         case FIONREAD:
1669                 if (!IFQ_IS_EMPTY(&TUN2IFP(tp)->if_snd)) {
1670                         struct mbuf *mb;
1671                         IFQ_LOCK(&TUN2IFP(tp)->if_snd);
1672                         IFQ_POLL_NOLOCK(&TUN2IFP(tp)->if_snd, mb);
1673                         for (*(int *)data = 0; mb != NULL; mb = mb->m_next)
1674                                 *(int *)data += mb->m_len;
1675                         IFQ_UNLOCK(&TUN2IFP(tp)->if_snd);
1676                 } else
1677                         *(int *)data = 0;
1678                 break;
1679         case FIOSETOWN:
1680                 return (fsetown(*(int *)data, &tp->tun_sigio));
1681
1682         case FIOGETOWN:
1683                 *(int *)data = fgetown(&tp->tun_sigio);
1684                 return (0);
1685
1686         /* This is deprecated, FIOSETOWN should be used instead. */
1687         case TIOCSPGRP:
1688                 return (fsetown(-(*(int *)data), &tp->tun_sigio));
1689
1690         /* This is deprecated, FIOGETOWN should be used instead. */
1691         case TIOCGPGRP:
1692                 *(int *)data = -fgetown(&tp->tun_sigio);
1693                 return (0);
1694
1695         default:
1696                 return (ENOTTY);
1697         }
1698         return (0);
1699 }
1700
1701 /*
1702  * The cdevsw read interface - reads a packet at a time, or at
1703  * least as much of a packet as can be read.
1704  */
1705 static  int
1706 tunread(struct cdev *dev, struct uio *uio, int flag)
1707 {
1708         struct tuntap_softc *tp = dev->si_drv1;
1709         struct ifnet    *ifp = TUN2IFP(tp);
1710         struct mbuf     *m;
1711         size_t          len;
1712         int             error = 0;
1713
1714         TUNDEBUG (ifp, "read\n");
1715         TUN_LOCK(tp);
1716         if ((tp->tun_flags & TUN_READY) != TUN_READY) {
1717                 TUN_UNLOCK(tp);
1718                 TUNDEBUG (ifp, "not ready 0%o\n", tp->tun_flags);
1719                 return (EHOSTDOWN);
1720         }
1721
1722         tp->tun_flags &= ~TUN_RWAIT;
1723
1724         for (;;) {
1725                 IFQ_DEQUEUE(&ifp->if_snd, m);
1726                 if (m != NULL)
1727                         break;
1728                 if (flag & O_NONBLOCK) {
1729                         TUN_UNLOCK(tp);
1730                         return (EWOULDBLOCK);
1731                 }
1732                 tp->tun_flags |= TUN_RWAIT;
1733                 error = mtx_sleep(tp, &tp->tun_mtx, PCATCH | (PZERO + 1),
1734                     "tunread", 0);
1735                 if (error != 0) {
1736                         TUN_UNLOCK(tp);
1737                         return (error);
1738                 }
1739         }
1740         TUN_UNLOCK(tp);
1741
1742         if ((tp->tun_flags & TUN_L2) != 0)
1743                 BPF_MTAP(ifp, m);
1744
1745         len = min(tp->tun_vhdrlen, uio->uio_resid);
1746         if (len > 0) {
1747                 struct virtio_net_hdr_mrg_rxbuf vhdr;
1748
1749                 bzero(&vhdr, sizeof(vhdr));
1750                 if (m->m_pkthdr.csum_flags & TAP_ALL_OFFLOAD) {
1751                         m = virtio_net_tx_offload(ifp, m, false, &vhdr.hdr);
1752                 }
1753
1754                 TUNDEBUG(ifp, "txvhdr: f %u, gt %u, hl %u, "
1755                     "gs %u, cs %u, co %u\n", vhdr.hdr.flags,
1756                     vhdr.hdr.gso_type, vhdr.hdr.hdr_len,
1757                     vhdr.hdr.gso_size, vhdr.hdr.csum_start,
1758                     vhdr.hdr.csum_offset);
1759                 error = uiomove(&vhdr, len, uio);
1760         }
1761
1762         while (m && uio->uio_resid > 0 && error == 0) {
1763                 len = min(uio->uio_resid, m->m_len);
1764                 if (len != 0)
1765                         error = uiomove(mtod(m, void *), len, uio);
1766                 m = m_free(m);
1767         }
1768
1769         if (m) {
1770                 TUNDEBUG(ifp, "Dropping mbuf\n");
1771                 m_freem(m);
1772         }
1773         return (error);
1774 }
1775
1776 static int
1777 tunwrite_l2(struct tuntap_softc *tp, struct mbuf *m,
1778             struct virtio_net_hdr_mrg_rxbuf *vhdr)
1779 {
1780         struct epoch_tracker et;
1781         struct ether_header *eh;
1782         struct ifnet *ifp;
1783
1784         ifp = TUN2IFP(tp);
1785
1786         /*
1787          * Only pass a unicast frame to ether_input(), if it would
1788          * actually have been received by non-virtual hardware.
1789          */
1790         if (m->m_len < sizeof(struct ether_header)) {
1791                 m_freem(m);
1792                 return (0);
1793         }
1794
1795         eh = mtod(m, struct ether_header *);
1796
1797         if (eh && (ifp->if_flags & IFF_PROMISC) == 0 &&
1798             !ETHER_IS_MULTICAST(eh->ether_dhost) &&
1799             bcmp(eh->ether_dhost, IF_LLADDR(ifp), ETHER_ADDR_LEN) != 0) {
1800                 m_freem(m);
1801                 return (0);
1802         }
1803
1804         if (vhdr != NULL && virtio_net_rx_csum(m, &vhdr->hdr)) {
1805                 m_freem(m);
1806                 return (0);
1807         }
1808
1809         /* Pass packet up to parent. */
1810         CURVNET_SET(ifp->if_vnet);
1811         NET_EPOCH_ENTER(et);
1812         (*ifp->if_input)(ifp, m);
1813         NET_EPOCH_EXIT(et);
1814         CURVNET_RESTORE();
1815         /* ibytes are counted in parent */
1816         if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1817         return (0);
1818 }
1819
1820 static int
1821 tunwrite_l3(struct tuntap_softc *tp, struct mbuf *m)
1822 {
1823         struct epoch_tracker et;
1824         struct ifnet *ifp;
1825         int family, isr;
1826
1827         ifp = TUN2IFP(tp);
1828         /* Could be unlocked read? */
1829         TUN_LOCK(tp);
1830         if (tp->tun_flags & TUN_IFHEAD) {
1831                 TUN_UNLOCK(tp);
1832                 if (m->m_len < sizeof(family) &&
1833                 (m = m_pullup(m, sizeof(family))) == NULL)
1834                         return (ENOBUFS);
1835                 family = ntohl(*mtod(m, u_int32_t *));
1836                 m_adj(m, sizeof(family));
1837         } else {
1838                 TUN_UNLOCK(tp);
1839                 family = AF_INET;
1840         }
1841
1842         BPF_MTAP2(ifp, &family, sizeof(family), m);
1843
1844         switch (family) {
1845 #ifdef INET
1846         case AF_INET:
1847                 isr = NETISR_IP;
1848                 break;
1849 #endif
1850 #ifdef INET6
1851         case AF_INET6:
1852                 isr = NETISR_IPV6;
1853                 break;
1854 #endif
1855         default:
1856                 m_freem(m);
1857                 return (EAFNOSUPPORT);
1858         }
1859         random_harvest_queue(m, sizeof(*m), RANDOM_NET_TUN);
1860         if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
1861         if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
1862         CURVNET_SET(ifp->if_vnet);
1863         M_SETFIB(m, ifp->if_fib);
1864         NET_EPOCH_ENTER(et);
1865         netisr_dispatch(isr, m);
1866         NET_EPOCH_EXIT(et);
1867         CURVNET_RESTORE();
1868         return (0);
1869 }
1870
1871 /*
1872  * the cdevsw write interface - an atomic write is a packet - or else!
1873  */
1874 static  int
1875 tunwrite(struct cdev *dev, struct uio *uio, int flag)
1876 {
1877         struct virtio_net_hdr_mrg_rxbuf vhdr;
1878         struct tuntap_softc *tp;
1879         struct ifnet    *ifp;
1880         struct mbuf     *m;
1881         uint32_t        mru;
1882         int             align, vhdrlen, error;
1883         bool            l2tun;
1884
1885         tp = dev->si_drv1;
1886         ifp = TUN2IFP(tp);
1887         TUNDEBUG(ifp, "tunwrite\n");
1888         if ((ifp->if_flags & IFF_UP) != IFF_UP)
1889                 /* ignore silently */
1890                 return (0);
1891
1892         if (uio->uio_resid == 0)
1893                 return (0);
1894
1895         l2tun = (tp->tun_flags & TUN_L2) != 0;
1896         mru = l2tun ? TAPMRU : TUNMRU;
1897         vhdrlen = tp->tun_vhdrlen;
1898         align = 0;
1899         if (l2tun) {
1900                 align = ETHER_ALIGN;
1901                 mru += vhdrlen;
1902         } else if ((tp->tun_flags & TUN_IFHEAD) != 0)
1903                 mru += sizeof(uint32_t);        /* family */
1904         if (uio->uio_resid < 0 || uio->uio_resid > mru) {
1905                 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid);
1906                 return (EIO);
1907         }
1908
1909         if (vhdrlen > 0) {
1910                 error = uiomove(&vhdr, vhdrlen, uio);
1911                 if (error != 0)
1912                         return (error);
1913                 TUNDEBUG(ifp, "txvhdr: f %u, gt %u, hl %u, "
1914                     "gs %u, cs %u, co %u\n", vhdr.hdr.flags,
1915                     vhdr.hdr.gso_type, vhdr.hdr.hdr_len,
1916                     vhdr.hdr.gso_size, vhdr.hdr.csum_start,
1917                     vhdr.hdr.csum_offset);
1918         }
1919
1920         if ((m = m_uiotombuf(uio, M_NOWAIT, 0, align, M_PKTHDR)) == NULL) {
1921                 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
1922                 return (ENOBUFS);
1923         }
1924
1925         m->m_pkthdr.rcvif = ifp;
1926 #ifdef MAC
1927         mac_ifnet_create_mbuf(ifp, m);
1928 #endif
1929
1930         if (l2tun)
1931                 return (tunwrite_l2(tp, m, vhdrlen > 0 ? &vhdr : NULL));
1932
1933         return (tunwrite_l3(tp, m));
1934 }
1935
1936 /*
1937  * tunpoll - the poll interface, this is only useful on reads
1938  * really. The write detect always returns true, write never blocks
1939  * anyway, it either accepts the packet or drops it.
1940  */
1941 static  int
1942 tunpoll(struct cdev *dev, int events, struct thread *td)
1943 {
1944         struct tuntap_softc *tp = dev->si_drv1;
1945         struct ifnet    *ifp = TUN2IFP(tp);
1946         int             revents = 0;
1947
1948         TUNDEBUG(ifp, "tunpoll\n");
1949
1950         if (events & (POLLIN | POLLRDNORM)) {
1951                 IFQ_LOCK(&ifp->if_snd);
1952                 if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
1953                         TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len);
1954                         revents |= events & (POLLIN | POLLRDNORM);
1955                 } else {
1956                         TUNDEBUG(ifp, "tunpoll waiting\n");
1957                         selrecord(td, &tp->tun_rsel);
1958                 }
1959                 IFQ_UNLOCK(&ifp->if_snd);
1960         }
1961         revents |= events & (POLLOUT | POLLWRNORM);
1962
1963         return (revents);
1964 }
1965
1966 /*
1967  * tunkqfilter - support for the kevent() system call.
1968  */
1969 static int
1970 tunkqfilter(struct cdev *dev, struct knote *kn)
1971 {
1972         struct tuntap_softc     *tp = dev->si_drv1;
1973         struct ifnet    *ifp = TUN2IFP(tp);
1974
1975         switch(kn->kn_filter) {
1976         case EVFILT_READ:
1977                 TUNDEBUG(ifp, "%s kqfilter: EVFILT_READ, minor = %#x\n",
1978                     ifp->if_xname, dev2unit(dev));
1979                 kn->kn_fop = &tun_read_filterops;
1980                 break;
1981
1982         case EVFILT_WRITE:
1983                 TUNDEBUG(ifp, "%s kqfilter: EVFILT_WRITE, minor = %#x\n",
1984                     ifp->if_xname, dev2unit(dev));
1985                 kn->kn_fop = &tun_write_filterops;
1986                 break;
1987
1988         default:
1989                 TUNDEBUG(ifp, "%s kqfilter: invalid filter, minor = %#x\n",
1990                     ifp->if_xname, dev2unit(dev));
1991                 return(EINVAL);
1992         }
1993
1994         kn->kn_hook = tp;
1995         knlist_add(&tp->tun_rsel.si_note, kn, 0);
1996
1997         return (0);
1998 }
1999
2000 /*
2001  * Return true of there is data in the interface queue.
2002  */
2003 static int
2004 tunkqread(struct knote *kn, long hint)
2005 {
2006         int                     ret;
2007         struct tuntap_softc     *tp = kn->kn_hook;
2008         struct cdev             *dev = tp->tun_dev;
2009         struct ifnet    *ifp = TUN2IFP(tp);
2010
2011         if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) {
2012                 TUNDEBUG(ifp,
2013                     "%s have data in the queue.  Len = %d, minor = %#x\n",
2014                     ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev));
2015                 ret = 1;
2016         } else {
2017                 TUNDEBUG(ifp,
2018                     "%s waiting for data, minor = %#x\n", ifp->if_xname,
2019                     dev2unit(dev));
2020                 ret = 0;
2021         }
2022
2023         return (ret);
2024 }
2025
2026 /*
2027  * Always can write, always return MTU in kn->data.
2028  */
2029 static int
2030 tunkqwrite(struct knote *kn, long hint)
2031 {
2032         struct tuntap_softc     *tp = kn->kn_hook;
2033         struct ifnet    *ifp = TUN2IFP(tp);
2034
2035         kn->kn_data = ifp->if_mtu;
2036
2037         return (1);
2038 }
2039
2040 static void
2041 tunkqdetach(struct knote *kn)
2042 {
2043         struct tuntap_softc     *tp = kn->kn_hook;
2044
2045         knlist_remove(&tp->tun_rsel.si_note, kn, 0);
2046 }