linux-2.6-526-tun-tap.patch

   1 diff -Nurb linux-2.6.22-525/drivers/net/Makefile linux-2.6.22-526/drivers/net/Makefile
   2 --- linux-2.6.22-525/drivers/net/Makefile       2008-07-09 15:41:30.000000000 -0400
   3 +++ linux-2.6.22-526/drivers/net/Makefile       2008-07-09 15:42:38.000000000 -0400
   4 @@ -1,7 +1,7 @@
   5  #
   6  # Makefile for the Linux network (ethercard) device drivers.
   7  #
   8 -
   9 +obj-m += vnet_tun.o
  10  obj-$(CONFIG_E1000) += e1000/
  11  obj-$(CONFIG_E1000E) += e1000e/
  12  obj-$(CONFIG_IBM_EMAC) += ibm_emac/
  13 diff -Nurb linux-2.6.22-525/drivers/net/vnet_tun.c linux-2.6.22-526/drivers/net/vnet_tun.c
  14 --- linux-2.6.22-525/drivers/net/vnet_tun.c     1969-12-31 19:00:00.000000000 -0500
  15 +++ linux-2.6.22-526/drivers/net/vnet_tun.c     2008-07-09 15:38:35.000000000 -0400
  16 @@ -0,0 +1,697 @@
  17 +/*
  18 + *  TUN - Universal TUN/TAP device driver.
  19 + *  Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
  20 + *  Modifications for PlanetLab by
  21 + *  Mark Huang <mlhuang@cs.princeton.edu>
  22 + *  Copyright (C) 2005 The Trustees of Princeton University
  23 + *  Ported to PlanetLab 4.2 by Sapan Bhatia <sapanb@cs.princeton.edu>
  24 + *
  25 + *  Modifications for PlanetLab by
  26 + *  Mark Huang <mlhuang@cs.princeton.edu>
  27 + *  Copyright (C) 2005 The Trustees of Princeton University
  28 + *
  29 + *  This program is free software; you can redistribute it and/or modify
  30 + *  it under the terms of the GNU General Public License as published by
  31 + *  the Free Software Foundation; either version 2 of the License, or
  32 + *  (at your option) any later version.
  33 + *
  34 + *  This program is distributed in the hope that it will be useful,
  35 + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  36 + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  37 + *  GNU General Public License for more details.
  38 + *
  39 + *  $Id: vnet_tun.c,v 1.10 2007/03/07 21:25:26 mef Exp $
  40 + */
  41 +
  42 +/*
  43 + *  Daniel Podlejski <underley@underley.eu.org>
  44 + *    Modifications for 2.3.99-pre5 kernel.
  45 + */
  46 +
  47 +#define TUN_VER "1.5"
  48 +
  49 +int vnet_verbose=1;
  50 +
  51 +#define dbg(format, args...) do { if (vnet_verbose >= 2) { printk(format, ## args); } } while (0)
  52 +#define err(format, args...) do { if (vnet_verbose >= 1) { printk(format, ## args); } } while (0)
  53 +
  54 +#include <linux/version.h>
  55 +#include <linux/module.h>
  56 +#include <linux/errno.h>
  57 +#include <linux/kernel.h>
  58 +#include <linux/major.h>
  59 +#include <linux/slab.h>
  60 +#include <linux/poll.h>
  61 +#include <linux/fcntl.h>
  62 +#include <linux/init.h>
  63 +#include <linux/random.h>
  64 +#include <linux/skbuff.h>
  65 +#include <linux/netdevice.h>
  66 +#include <linux/etherdevice.h>
  67 +#include <linux/miscdevice.h>
  68 +#include <linux/rtnetlink.h>
  69 +#include <linux/if.h>
  70 +#include <linux/if_arp.h>
  71 +#include <linux/if_ether.h>
  72 +#include <linux/if_tun.h>
  73 +
  74 +#include <asm/system.h>
  75 +#include <asm/uaccess.h>
  76 +
  77 +/*
  78 + * PlanetLab TAP device
  79 + *
  80 + * A single, persistent tap0 to /dev/net/tun tunnel. Packets sent out
  81 + * the tap0 device, via either IP or raw sockets, are queued to both
  82 + * the sending slice's /dev/net/tun queue, and the root queue. Only
  83 + * one reader of each queue is allowed at a time. Any type of packet
  84 + * may be written to /dev/net/tun and received via packet socket(s)
  85 + * bound to tap0. However, only locally destined IP packets will be
  86 + * injected into the stack, and such packets are subject to the same
  87 + * connection tracking and ownership assignment that all inbound IP
  88 + * packets are subject to.
  89 + */
  90 +
  91 +struct net_device tun_netdev;
  92 +static struct net_device_stats tun_stats;
  93 +
  94 +#define get_sk_xid(sk) sk->sk_nid
  95 +#define set_sk_xid(sk,xid) sk->sk_nid=xid
  96 +#define set_skb_xid(skb,xid) skb->skb_tag=xid
  97 +
  98 +/* Extended fields */
  99 +struct tun_pi_ext {
 100 +       unsigned long mark;
 101 +       long timestamp_sec;
 102 +       long timestamp_usec;
 103 +};
 104 +#define TUN_PKT_EXT    0x0002
 105 +
 106 +#include <net/ip.h>
 107 +
 108 +/* UID hash function stolen from kernel/user.c */
 109 +#define XIDHASH_BITS           8
 110 +#define XIDHASH_SZ             (1 << XIDHASH_BITS)
 111 +#define XIDHASH_MASK           (XIDHASH_SZ - 1)
 112 +#define __xidhashfn(xid)       (((xid >> XIDHASH_BITS) + xid) & XIDHASH_MASK)
 113 +
 114 +static struct list_head tun_dev_hash[XIDHASH_SZ];
 115 +static rwlock_t tun_dev_hash_lock = RW_LOCK_UNLOCKED;
 116 +
 117 +static inline xid_t
 118 +get_file_xid(struct file *file)
 119 +{
 120 +               return file->f_xid;
 121 +}
 122 +
 123 +static inline void
 124 +set_file_xid(struct file *file, xid_t xid)
 125 +{
 126 +               file->f_xid = xid;
 127 +}
 128 +
 129 +static struct tun_struct *tun_get_by_xid(xid_t xid)
 130 +{
 131 +       struct tun_struct *tun;
 132 +
 133 +       read_lock_bh(&tun_dev_hash_lock);
 134 +
 135 +       list_for_each_entry(tun, &tun_dev_hash[__xidhashfn(xid)], list) {
 136 +               if (tun->owner == xid) {
 137 +                       read_unlock_bh(&tun_dev_hash_lock);
 138 +                       return tun;
 139 +               }
 140 +       }
 141 +
 142 +       read_unlock_bh(&tun_dev_hash_lock);
 143 +
 144 +       return NULL;
 145 +}
 146 +
 147 +/* Network device part of the driver */
 148 +
 149 +static void tun_xmit(struct sk_buff *skb, struct tun_struct *tun)
 150 +{
 151 +       /* Drop packet if interface is not attached */
 152 +       if (!tun || !tun->attached)
 153 +               goto drop;
 154 +
 155 +       dbg("%s:%d: tun_xmit %d\n", tun->dev->name, tun->owner, skb->len);
 156 +
 157 +       /* Queue packet */
 158 +       if (skb_queue_len(&tun->readq) >= tun->dev->tx_queue_len)
 159 +               goto drop;
 160 +
 161 +       skb = skb_clone(skb, GFP_ATOMIC);
 162 +       if (!skb)
 163 +               goto drop;
 164 +
 165 +       skb_queue_tail(&tun->readq, skb);
 166 +
 167 +       /* Notify and wake up reader process */
 168 +       if (tun->flags & TUN_FASYNC)
 169 +               kill_fasync(&tun->fasync, SIGIO, POLL_IN);
 170 +       wake_up_interruptible(&tun->read_wait);
 171 +
 172 + drop:
 173 +       if (tun)
 174 +               tun->stats.tx_dropped++;
 175 +       tun_stats.tx_dropped++;
 176 +}
 177 +
 178 +/* Net device start xmit */
 179 +static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 180 +{
 181 +       xid_t xid = get_sk_xid(skb->sk);
 182 +       struct tun_struct *tun = tun_get_by_xid(xid);
 183 +
 184 +       /* Mark packet */
 185 +       set_skb_xid(skb, xid);
 186 +
 187 +       tun_xmit(skb, tun);
 188 +
 189 +       /* Copy root on packets that the slice is not listening for */
 190 +       if ((!tun || !tun->attached) && xid) {
 191 +               tun = tun_get_by_xid(0);
 192 +               tun_xmit(skb, tun);
 193 +       }
 194 +
 195 +       kfree_skb(skb);
 196 +       return 0;
 197 +}
 198 +
 199 +static void tun_net_mclist(struct net_device *dev)
 200 +{
 201 +       /* Nothing to do for multicast filters.
 202 +        * We always accept all frames. */
 203 +       return;
 204 +}
 205 +
 206 +static struct net_device_stats *tun_net_stats(struct net_device *dev)
 207 +{
 208 +       struct tun_struct *tun = tun_get_by_xid(current->xid);
 209 +       return tun ? &tun->stats : &tun_stats;
 210 +}
 211 +
 212 +/* Character device part */
 213 +
 214 +/* Poll */
 215 +static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
 216 +{
 217 +       struct tun_struct *tun = file->private_data;
 218 +       unsigned int mask = POLLOUT | POLLWRNORM;
 219 +
 220 +       if (!tun)
 221 +               return -EBADFD;
 222 +
 223 +       dbg("%s:%d: tun_chr_poll\n", tun->dev->name, tun->owner);
 224 +
 225 +       poll_wait(file, &tun->read_wait, wait);
 226 +
 227 +       if (skb_queue_len(&tun->readq))
 228 +               mask |= POLLIN | POLLRDNORM;
 229 +
 230 +       return mask;
 231 +}
 232 +
 233 +/* Get packet from user space buffer */
 234 +static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
 235 +{
 236 +       struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
 237 +       struct tun_pi_ext pi_ext;
 238 +       struct sk_buff *skb;
 239 +       size_t len = count;
 240 +
 241 +       if (!(tun->flags & TUN_NO_PI)) {
 242 +               if ((len -= sizeof(pi)) < 0)
 243 +                       return -EINVAL;
 244 +
 245 +               if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
 246 +                       return -EFAULT;
 247 +
 248 +               if (pi.flags & TUN_PKT_EXT) {
 249 +                       if ((len -= sizeof(pi_ext)) < 0)
 250 +                               return -EINVAL;
 251 +
 252 +                       if (memcpy_fromiovec((void *)&pi_ext, iv, sizeof(pi_ext)))
 253 +                               return -EFAULT;
 254 +               }
 255 +       }
 256 +
 257 +       if (!(skb = alloc_skb(len + 2, GFP_KERNEL))) {
 258 +               tun->stats.rx_dropped++;
 259 +               tun_stats.rx_dropped++;
 260 +               return -ENOMEM;
 261 +       }
 262 +
 263 +       skb_reserve(skb, 2);
 264 +       if (memcpy_fromiovec(skb_put(skb, len), iv, len))
 265 +               return -EFAULT;
 266 +
 267 +       skb->dev = tun->dev;
 268 +       switch (tun->flags & TUN_TYPE_MASK) {
 269 +       case TUN_TUN_DEV:
 270 +               skb_reset_mac_header(skb);
 271 +               skb->protocol = pi.proto;
 272 +               break;
 273 +       case TUN_TAP_DEV:
 274 +               skb->protocol = eth_type_trans(skb, tun->dev);
 275 +               break;
 276 +       };
 277 +
 278 +       if (tun->flags & TUN_NOCHECKSUM)
 279 +               skb->ip_summed = CHECKSUM_UNNECESSARY;
 280 +
 281 +       /* Mark packet */
 282 +       set_skb_xid(skb, tun->owner);
 283 +
 284 +       netif_rx_ni(skb);
 285 +
 286 +       tun->stats.rx_packets++;
 287 +       tun->stats.rx_bytes += len;
 288 +       tun_stats.rx_packets++;
 289 +       tun_stats.rx_bytes += len;
 290 +
 291 +       return count;
 292 +}
 293 +
 294 +static inline size_t iov_total(const struct iovec *iv, unsigned long count)
 295 +{
 296 +       unsigned long i;
 297 +       size_t len;
 298 +
 299 +       for (i = 0, len = 0; i < count; i++)
 300 +               len += iv[i].iov_len;
 301 +
 302 +       return len;
 303 +}
 304 +
 305 +/* Writev - Obsolete in 2.6.22, but let's keep this aroudn just in case */
 306 +static ssize_t tun_chr_writev(struct file * file, const struct iovec *iv,
 307 +                             unsigned long count, loff_t *pos)
 308 +{
 309 +       struct tun_struct *tun = file->private_data;
 310 +
 311 +       if (!tun)
 312 +               return -EBADFD;
 313 +
 314 +       dbg("%s:%d: tun_chr_write %ld\n", tun->dev->name, tun->owner, count);
 315 +
 316 +       return tun_get_user(tun, (struct iovec *) iv, iov_total(iv, count));
 317 +}
 318 +
 319 +/* Write */
 320 +static ssize_t tun_chr_write(struct file * file, const char __user * buf,
 321 +                            size_t count, loff_t *pos)
 322 +{
 323 +       struct iovec iv = { (void __user *) buf, count };
 324 +       return tun_chr_writev(file, &iv, 1, pos);
 325 +}
 326 +
 327 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,14)
 328 +
 329 +static inline void skb_get_timestamp(const struct sk_buff *skb, struct timeval *stamp)
 330 +{
 331 +       stamp->tv_sec = skb->stamp.tv_sec;
 332 +       stamp->tv_usec = skb->stamp.tv_usec;
 333 +}
 334 +
 335 +static inline void skb_set_timestamp(struct sk_buff *skb, const struct timeval *stamp)
 336 +{
 337 +       skb->stamp.tv_sec = stamp->tv_sec;
 338 +       skb->stamp.tv_usec = stamp->tv_usec;
 339 +}
 340 +
 341 +static void __net_timestamp(struct sk_buff *skb)
 342 +{
 343 +       struct timeval tv;
 344 +
 345 +       do_gettimeofday(&tv);
 346 +       skb_set_timestamp(skb, &tv);
 347 +}
 348 +
 349 +#endif
 350 +
 351 +/* Put packet to the user space buffer */
 352 +static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
 353 +                                      struct sk_buff *skb,
 354 +                                      struct iovec *iv, int len)
 355 +{
 356 +       struct tun_pi pi;
 357 +       struct tun_pi_ext pi_ext;
 358 +       struct timeval stamp;
 359 +       ssize_t total = 0;
 360 +
 361 +       if (!(tun->flags & TUN_NO_PI)) {
 362 +               struct iovec iv1 = { iv->iov_base, iv->iov_len };
 363 +
 364 +               if ((len -= sizeof(pi)) < 0)
 365 +                       return -EINVAL;
 366 +
 367 +               if (memcpy_fromiovec((void *)&pi, &iv1, sizeof(pi)))
 368 +                       return -EFAULT;
 369 +
 370 +               if (pi.flags & TUN_PKT_EXT) {
 371 +                       if ((len -= sizeof(pi_ext)) < 0)
 372 +                               return -EINVAL;
 373 +
 374 +                       /* We might not have a timestamp, get one */
 375 +                       skb_get_timestamp(skb, &stamp);
 376 +                       if (stamp.tv_sec == 0) {
 377 +                               __net_timestamp(skb);
 378 +                               skb_get_timestamp(skb, &stamp);
 379 +                       }
 380 +
 381 +                       pi.flags = TUN_PKT_EXT;
 382 +                       pi.proto = skb->protocol;
 383 +                       pi_ext.timestamp_sec = stamp.tv_sec;
 384 +                       pi_ext.timestamp_usec = stamp.tv_usec;
 385 +                       pi_ext.mark = skb->skb_tag;
 386 +               } else {
 387 +                       pi.flags = 0;
 388 +                       pi.proto = skb->protocol;
 389 +               }
 390 +
 391 +               if (len < skb->len) {
 392 +                       /* Packet will be striped */
 393 +                       pi.flags |= TUN_PKT_STRIP;
 394 +               }
 395 +
 396 +               if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
 397 +                       return -EFAULT;
 398 +               total += sizeof(pi);
 399 +
 400 +               if (pi.flags & TUN_PKT_EXT) {
 401 +                       if (memcpy_toiovec(iv, (void *) &pi_ext, sizeof(pi_ext)))
 402 +                               return -EFAULT;
 403 +                       total += sizeof(pi_ext);
 404 +               }
 405 +       }
 406 +
 407 +       len = min_t(int, skb->len, len);
 408 +
 409 +       skb_copy_datagram_iovec(skb, 0, iv, len);
 410 +       total += len;
 411 +
 412 +       tun->stats.tx_packets++;
 413 +       tun->stats.tx_bytes += len;
 414 +       tun_stats.tx_packets++;
 415 +       tun_stats.tx_bytes += len;
 416 +
 417 +       return total;
 418 +}
 419 +
 420 +/* Readv - Obsolete in 2.6.22, but let's keep this aroudn just in case */
 421 +static ssize_t tun_chr_readv(struct file *file, const struct iovec *iv,
 422 +                           unsigned long count, loff_t *pos)
 423 +{
 424 +       struct tun_struct *tun = file->private_data;
 425 +       DECLARE_WAITQUEUE(wait, current);
 426 +       struct sk_buff *skb;
 427 +       ssize_t len, ret = 0;
 428 +
 429 +       if (!tun)
 430 +               return -EBADFD;
 431 +
 432 +       dbg("%s:%d: tun_chr_read\n", tun->dev->name, tun->owner);
 433 +
 434 +       len = iov_total(iv, count);
 435 +       if (len < 0)
 436 +               return -EINVAL;
 437 +
 438 +       add_wait_queue(&tun->read_wait, &wait);
 439 +       while (len) {
 440 +               current->state = TASK_INTERRUPTIBLE;
 441 +
 442 +               /* Read frames from the queue */
 443 +               if (!(skb=skb_dequeue(&tun->readq))) {
 444 +                       if (file->f_flags & O_NONBLOCK) {
 445 +                               ret = -EAGAIN;
 446 +                               break;
 447 +                       }
 448 +                       if (signal_pending(current)) {
 449 +                               ret = -ERESTARTSYS;
 450 +                               break;
 451 +                       }
 452 +
 453 +                       /* Nothing to read, let's sleep */
 454 +                       schedule();
 455 +                       continue;
 456 +               }
 457 +
 458 +               ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
 459 +
 460 +               kfree_skb(skb);
 461 +               break;
 462 +       }
 463 +
 464 +       current->state = TASK_RUNNING;
 465 +       remove_wait_queue(&tun->read_wait, &wait);
 466 +
 467 +       return ret;
 468 +}
 469 +
 470 +/* Read */
 471 +static ssize_t tun_chr_read(struct file * file, char __user * buf,
 472 +                           size_t count, loff_t *pos)
 473 +{
 474 +       struct iovec iv = { buf, count };
 475 +       return tun_chr_readv(file, &iv, 1, pos);
 476 +}
 477 +
 478 +static int tun_set_iff(struct file *file, struct ifreq *ifr)
 479 +{
 480 +       struct tun_struct *tun;
 481 +
 482 +       tun = tun_get_by_xid(get_file_xid(file));
 483 +       if (tun) {
 484 +               if (tun->attached)
 485 +                       return -EBUSY;
 486 +
 487 +               /* Check permissions */
 488 +               if (tun->owner != -1 &&
 489 +                   get_file_xid(file) != tun->owner && !capable(CAP_NET_ADMIN))
 490 +                       return -EPERM;
 491 +       }
 492 +       else {
 493 +               /* Create a new queue */
 494 +               tun = kmalloc(sizeof(struct tun_struct), GFP_KERNEL);
 495 +               if (!tun)
 496 +                       return -ENOMEM;
 497 +               memset(tun, 0, sizeof(struct tun_struct));
 498 +
 499 +               tun->dev = &tun_netdev;
 500 +
 501 +               skb_queue_head_init(&tun->readq);
 502 +               init_waitqueue_head(&tun->read_wait);
 503 +
 504 +               tun->owner = get_file_xid(file);
 505 +
 506 +               write_lock_bh(&tun_dev_hash_lock);
 507 +               list_add(&tun->list, &tun_dev_hash[__xidhashfn(get_file_xid(file))]);
 508 +               write_unlock_bh(&tun_dev_hash_lock);
 509 +       }
 510 +
 511 +       dbg("%s:%d: tun_set_iff\n", tun->dev->name, tun->owner);
 512 +
 513 +       tun->flags = TUN_TAP_DEV;
 514 +
 515 +       if (ifr->ifr_flags & IFF_NO_PI)
 516 +               tun->flags |= TUN_NO_PI;
 517 +
 518 +       file->private_data = tun;
 519 +       tun->attached = 1;
 520 +
 521 +       strcpy(ifr->ifr_name, tun->dev->name);
 522 +       return 0;
 523 +}
 524 +
 525 +static int tun_chr_ioctl(struct inode *inode, struct file *file,
 526 +                        unsigned int cmd, unsigned long arg)
 527 +{
 528 +       struct tun_struct *tun = file->private_data;
 529 +
 530 +       if (cmd == TUNSETIFF && !tun) {
 531 +               struct ifreq ifr;
 532 +               int err;
 533 +
 534 +               if (copy_from_user(&ifr, (void __user *)arg, sizeof(ifr)))
 535 +                       return -EFAULT;
 536 +               ifr.ifr_name[IFNAMSIZ-1] = '\0';
 537 +
 538 +               err = tun_set_iff(file, &ifr);
 539 +
 540 +               if (err)
 541 +                       return err;
 542 +
 543 +               if (copy_to_user((void __user *)arg, &ifr, sizeof(ifr)))
 544 +                       return -EFAULT;
 545 +               return 0;
 546 +       }
 547 +
 548 +       if (!tun)
 549 +               return -EBADFD;
 550 +
 551 +       dbg("%s:%d: tun_chr_ioctl cmd %d\n", tun->dev->name, tun->owner, cmd);
 552 +
 553 +       switch (cmd) {
 554 +       case TUNSETNOCSUM:
 555 +               /* Disable/Enable checksum */
 556 +               if (arg)
 557 +                       tun->flags |= TUN_NOCHECKSUM;
 558 +               else
 559 +                       tun->flags &= ~TUN_NOCHECKSUM;
 560 +
 561 +               dbg("%s:%d: checksum %s\n",
 562 +                   tun->dev->name, tun->owner, arg ? "disabled" : "enabled");
 563 +               break;
 564 +
 565 +       case TUNSETPERSIST:
 566 +       case TUNSETOWNER:
 567 +       case TUNSETDEBUG:
 568 +               /* Not applicable */
 569 +               break;
 570 +
 571 +       default:
 572 +               return -EINVAL;
 573 +       };
 574 +
 575 +       return 0;
 576 +}
 577 +
 578 +static int tun_chr_fasync(int fd, struct file *file, int on)
 579 +{
 580 +       struct tun_struct *tun = file->private_data;
 581 +       int ret;
 582 +
 583 +       if (!tun)
 584 +               return -EBADFD;
 585 +
 586 +       dbg("%s:%d: tun_chr_fasync %d\n", tun->dev->name, tun->owner, on);
 587 +
 588 +       if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
 589 +               return ret;
 590 +
 591 +       if (on) {
 592 +               ret = f_setown(file, current->pid, 0);
 593 +               if (ret)
 594 +                       return ret;
 595 +               tun->flags |= TUN_FASYNC;
 596 +       } else
 597 +               tun->flags &= ~TUN_FASYNC;
 598 +
 599 +       return 0;
 600 +}
 601 +
 602 +static int tun_chr_open(struct inode *inode, struct file * file)
 603 +{
 604 +       dbg("tunX: tun_chr_open\n");
 605 +       file->private_data = NULL;
 606 +       return 0;
 607 +}
 608 +
 609 +static int tun_chr_close(struct inode *inode, struct file *file)
 610 +{
 611 +       struct tun_struct *tun = file->private_data;
 612 +
 613 +       if (!tun)
 614 +               return 0;
 615 +
 616 +       dbg("%s:%d: tun_chr_close\n", tun->dev->name, tun->owner);
 617 +
 618 +       tun_chr_fasync(-1, file, 0);
 619 +
 620 +       /* Detach from net device */
 621 +       file->private_data = NULL;
 622 +       tun->attached = 0;
 623 +
 624 +       /* Drop read queue */
 625 +       skb_queue_purge(&tun->readq);
 626 +
 627 +       return 0;
 628 +}
 629 +
 630 +static struct file_operations tun_fops = {
 631 +       .owner  = THIS_MODULE,
 632 +       .llseek = no_llseek,
 633 +       .read   = tun_chr_read,
 634 +       //.readv        = tun_chr_readv,
 635 +       .write  = tun_chr_write,
 636 +       //.writev = tun_chr_writev,
 637 +       .poll   = tun_chr_poll,
 638 +       .ioctl  = tun_chr_ioctl,
 639 +       .open   = tun_chr_open,
 640 +       .release = tun_chr_close,
 641 +       .fasync = tun_chr_fasync
 642 +};
 643 +
 644 +static struct miscdevice tun_miscdev = {
 645 +       .minor = TUN_MINOR,
 646 +       .name = "tun",
 647 +       .fops = &tun_fops,
 648 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,18)
 649 +       .devfs_name = "net/tun",
 650 +#endif
 651 +};
 652 +
 653 +int __init tun_init(void)
 654 +{
 655 +       int ret = 0;
 656 +       struct net_device *dev = &tun_netdev;
 657 +       int i;
 658 +
 659 +       /* Initialize hash table */
 660 +       for (i = 0; i < XIDHASH_SZ; i++)
 661 +               INIT_LIST_HEAD(&tun_dev_hash[i]);
 662 +
 663 +       ret = misc_register(&tun_miscdev);
 664 +       if (ret) {
 665 +               err("tun: Can't register misc device %d\n", TUN_MINOR);
 666 +               return ret;
 667 +       }
 668 +
 669 +       memset(dev, 0, sizeof(struct net_device));
 670 +
 671 +       /* Ethernet TAP Device */
 672 +       dev->set_multicast_list = tun_net_mclist;
 673 +
 674 +       /* Generate random Ethernet address.  */
 675 +       *(u16 *)dev->dev_addr = htons(0x00FF);
 676 +       get_random_bytes(dev->dev_addr + sizeof(u16), 4);
 677 +
 678 +       ether_setup(dev);
 679 +
 680 +       dev->flags |= IFF_NOARP | IFF_POINTOPOINT;
 681 +       dev->flags &= ~IFF_MULTICAST;
 682 +
 683 +       SET_MODULE_OWNER(dev);
 684 +       dev->hard_start_xmit = tun_net_xmit;
 685 +       dev->get_stats = tun_net_stats;
 686 +
 687 +       strcpy(dev->name, "tap0");
 688 +
 689 +       ret = register_netdev(dev);
 690 +       if (ret < 0)
 691 +               misc_deregister(&tun_miscdev);
 692 +
 693 +       return ret;
 694 +}
 695 +
 696 +void __exit tun_cleanup(void)
 697 +{
 698 +       struct tun_struct *tun, *nxt;
 699 +       int i;
 700 +
 701 +       misc_deregister(&tun_miscdev);
 702 +
 703 +       write_lock_bh(&tun_dev_hash_lock);
 704 +       for (i = 0; i < XIDHASH_SZ; i++) {
 705 +               list_for_each_entry_safe(tun, nxt, &tun_dev_hash[i], list) {
 706 +                       skb_queue_purge(&tun->readq);
 707 +                       kfree(tun);
 708 +               }
 709 +       }
 710 +       write_unlock_bh(&tun_dev_hash_lock);
 711 +
 712 +       unregister_netdev(&tun_netdev);
 713 +}