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   1 /*
   2  *  TUN - Universal TUN/TAP device driver.
   3  *  Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
  16  */
  17
  18 /*
  19  *  Changes:
  20  *
  21  *  Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
  22  *    Add TUNSETLINK ioctl to set the link encapsulation
  23  *
  24  *  Mark Smith <markzzzsmith@yahoo.com.au>
  25  *    Use random_ether_addr() for tap MAC address.
  26  *
  27  *  Harald Roelle <harald.roelle@ifi.lmu.de>  2004/04/20
  28  *    Fixes in packet dropping, queue length setting and queue wakeup.
  29  *    Increased default tx queue length.
  30  *    Added ethtool API.
  31  *    Minor cleanups
  32  *
  33  *  Daniel Podlejski <underley@underley.eu.org>
  34  *    Modifications for 2.3.99-pre5 kernel.
  35  */
  36
  37 #define DRV_NAME        "tun"
  38 #define DRV_VERSION     "1.6"
  39 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
  40 #define DRV_COPYRIGHT   "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
  41
  42 #include <linux/module.h>
  43 #include <linux/errno.h>
  44 #include <linux/kernel.h>
  45 #include <linux/major.h>
  46 #include <linux/slab.h>
  47 #include <linux/smp_lock.h>
  48 #include <linux/poll.h>
  49 #include <linux/fcntl.h>
  50 #include <linux/init.h>
  51 #include <linux/skbuff.h>
  52 #include <linux/netdevice.h>
  53 #include <linux/etherdevice.h>
  54 #include <linux/miscdevice.h>
  55 #include <linux/ethtool.h>
  56 #include <linux/rtnetlink.h>
  57 #include <linux/if.h>
  58 #include <linux/if_arp.h>
  59 #include <linux/if_ether.h>
  60 #include <linux/if_tun.h>
  61 #include <linux/crc32.h>
  62 #include <linux/nsproxy.h>
  63 #include <linux/virtio_net.h>
  64 #include <net/net_namespace.h>
  65 #include <net/netns/generic.h>
  66
  67 #include <asm/system.h>
  68 #include <asm/uaccess.h>
  69
  70 /* Uncomment to enable debugging */
  71 /* #define TUN_DEBUG 1 */
  72
  73 #ifdef TUN_DEBUG
  74 static int debug;
  75
  76 #define DBG  if(tun->debug)printk
  77 #define DBG1 if(debug==2)printk
  78 #else
  79 #define DBG( a... )
  80 #define DBG1( a... )
  81 #endif
  82
  83 #define FLT_EXACT_COUNT 8
  84 struct tap_filter {
  85         unsigned int    count;    /* Number of addrs. Zero means disabled */
  86         u32             mask[2];  /* Mask of the hashed addrs */
  87         unsigned char   addr[FLT_EXACT_COUNT][ETH_ALEN];
  88 };
  89
  90 struct tun_file {
  91         atomic_t count;
  92         struct tun_struct *tun;
  93         struct net *net;
  94         wait_queue_head_t       read_wait;
  95 };
  96
  97 struct tun_struct {
  98         struct tun_file         *tfile;
  99         unsigned int            flags;
 100         uid_t                   owner;
 101         gid_t                   group;
 102
 103         struct sk_buff_head     readq;
 104
 105         struct net_device       *dev;
 106         struct fasync_struct    *fasync;
 107
 108         struct tap_filter       txflt;
 109
 110 #ifdef TUN_DEBUG
 111         int debug;
 112 #endif
 113 };
 114
 115 static int tun_attach(struct tun_struct *tun, struct file *file)
 116 {
 117         struct tun_file *tfile = file->private_data;
 118         const struct cred *cred = current_cred();
 119         int err;
 120
 121         ASSERT_RTNL();
 122
 123         /* Check permissions */
 124         if (((tun->owner != -1 && cred->euid != tun->owner) ||
 125              (tun->group != -1 && cred->egid != tun->group)) &&
 126                 !capable(CAP_NET_ADMIN))
 127                 return -EPERM;
 128
 129         netif_tx_lock_bh(tun->dev);
 130
 131         err = -EINVAL;
 132         if (tfile->tun)
 133                 goto out;
 134
 135         err = -EBUSY;
 136         if (tun->tfile)
 137                 goto out;
 138
 139         err = 0;
 140         tfile->tun = tun;
 141         tun->tfile = tfile;
 142         dev_hold(tun->dev);
 143         atomic_inc(&tfile->count);
 144
 145 out:
 146         netif_tx_unlock_bh(tun->dev);
 147         return err;
 148 }
 149
 150 static void __tun_detach(struct tun_struct *tun)
 151 {
 152         struct tun_file *tfile = tun->tfile;
 153
 154         /* Detach from net device */
 155         netif_tx_lock_bh(tun->dev);
 156         tfile->tun = NULL;
 157         tun->tfile = NULL;
 158         netif_tx_unlock_bh(tun->dev);
 159
 160         /* Drop read queue */
 161         skb_queue_purge(&tun->readq);
 162
 163         /* Drop the extra count on the net device */
 164         dev_put(tun->dev);
 165 }
 166
 167 static void tun_detach(struct tun_struct *tun)
 168 {
 169         rtnl_lock();
 170         __tun_detach(tun);
 171         rtnl_unlock();
 172 }
 173
 174 static struct tun_struct *__tun_get(struct tun_file *tfile)
 175 {
 176         struct tun_struct *tun = NULL;
 177
 178         if (atomic_inc_not_zero(&tfile->count))
 179                 tun = tfile->tun;
 180
 181         return tun;
 182 }
 183
 184 static struct tun_struct *tun_get(struct file *file)
 185 {
 186         return __tun_get(file->private_data);
 187 }
 188
 189 static void tun_put(struct tun_struct *tun)
 190 {
 191         struct tun_file *tfile = tun->tfile;
 192
 193         if (atomic_dec_and_test(&tfile->count))
 194                 tun_detach(tfile->tun);
 195 }
 196
 197 /* TAP filterting */
 198 static void addr_hash_set(u32 *mask, const u8 *addr)
 199 {
 200         int n = ether_crc(ETH_ALEN, addr) >> 26;
 201         mask[n >> 5] |= (1 << (n & 31));
 202 }
 203
 204 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
 205 {
 206         int n = ether_crc(ETH_ALEN, addr) >> 26;
 207         return mask[n >> 5] & (1 << (n & 31));
 208 }
 209
 210 static int update_filter(struct tap_filter *filter, void __user *arg)
 211 {
 212         struct { u8 u[ETH_ALEN]; } *addr;
 213         struct tun_filter uf;
 214         int err, alen, n, nexact;
 215
 216         if (copy_from_user(&uf, arg, sizeof(uf)))
 217                 return -EFAULT;
 218
 219         if (!uf.count) {
 220                 /* Disabled */
 221                 filter->count = 0;
 222                 return 0;
 223         }
 224
 225         alen = ETH_ALEN * uf.count;
 226         addr = kmalloc(alen, GFP_KERNEL);
 227         if (!addr)
 228                 return -ENOMEM;
 229
 230         if (copy_from_user(addr, arg + sizeof(uf), alen)) {
 231                 err = -EFAULT;
 232                 goto done;
 233         }
 234
 235         /* The filter is updated without holding any locks. Which is
 236          * perfectly safe. We disable it first and in the worst
 237          * case we'll accept a few undesired packets. */
 238         filter->count = 0;
 239         wmb();
 240
 241         /* Use first set of addresses as an exact filter */
 242         for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
 243                 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
 244
 245         nexact = n;
 246
 247         /* The rest is hashed */
 248         memset(filter->mask, 0, sizeof(filter->mask));
 249         for (; n < uf.count; n++)
 250                 addr_hash_set(filter->mask, addr[n].u);
 251
 252         /* For ALLMULTI just set the mask to all ones.
 253          * This overrides the mask populated above. */
 254         if ((uf.flags & TUN_FLT_ALLMULTI))
 255                 memset(filter->mask, ~0, sizeof(filter->mask));
 256
 257         /* Now enable the filter */
 258         wmb();
 259         filter->count = nexact;
 260
 261         /* Return the number of exact filters */
 262         err = nexact;
 263
 264 done:
 265         kfree(addr);
 266         return err;
 267 }
 268
 269 /* Returns: 0 - drop, !=0 - accept */
 270 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
 271 {
 272         /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
 273          * at this point. */
 274         struct ethhdr *eh = (struct ethhdr *) skb->data;
 275         int i;
 276
 277         /* Exact match */
 278         for (i = 0; i < filter->count; i++)
 279                 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
 280                         return 1;
 281
 282         /* Inexact match (multicast only) */
 283         if (is_multicast_ether_addr(eh->h_dest))
 284                 return addr_hash_test(filter->mask, eh->h_dest);
 285
 286         return 0;
 287 }
 288
 289 /*
 290  * Checks whether the packet is accepted or not.
 291  * Returns: 0 - drop, !=0 - accept
 292  */
 293 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
 294 {
 295         if (!filter->count)
 296                 return 1;
 297
 298         return run_filter(filter, skb);
 299 }
 300
 301 /* Network device part of the driver */
 302
 303 static const struct ethtool_ops tun_ethtool_ops;
 304
 305 /* Net device detach from fd. */
 306 static void tun_net_uninit(struct net_device *dev)
 307 {
 308         struct tun_struct *tun = netdev_priv(dev);
 309         struct tun_file *tfile = tun->tfile;
 310
 311         /* Inform the methods they need to stop using the dev.
 312          */
 313         if (tfile) {
 314                 wake_up_all(&tfile->read_wait);
 315                 if (atomic_dec_and_test(&tfile->count))
 316                         __tun_detach(tun);
 317         }
 318 }
 319
 320 /* Net device open. */
 321 static int tun_net_open(struct net_device *dev)
 322 {
 323         netif_start_queue(dev);
 324         return 0;
 325 }
 326
 327 /* Net device close. */
 328 static int tun_net_close(struct net_device *dev)
 329 {
 330         netif_stop_queue(dev);
 331         return 0;
 332 }
 333
 334 /* Net device start xmit */
 335 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 336 {
 337         struct tun_struct *tun = netdev_priv(dev);
 338
 339         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
 340
 341         /* Drop packet if interface is not attached */
 342         if (!tun->tfile)
 343                 goto drop;
 344
 345         /* Drop if the filter does not like it.
 346          * This is a noop if the filter is disabled.
 347          * Filter can be enabled only for the TAP devices. */
 348         if (!check_filter(&tun->txflt, skb))
 349                 goto drop;
 350
 351         if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
 352                 if (!(tun->flags & TUN_ONE_QUEUE)) {
 353                         /* Normal queueing mode. */
 354                         /* Packet scheduler handles dropping of further packets. */
 355                         netif_stop_queue(dev);
 356
 357                         /* We won't see all dropped packets individually, so overrun
 358                          * error is more appropriate. */
 359                         dev->stats.tx_fifo_errors++;
 360                 } else {
 361                         /* Single queue mode.
 362                          * Driver handles dropping of all packets itself. */
 363                         goto drop;
 364                 }
 365         }
 366
 367         /* Enqueue packet */
 368         skb_queue_tail(&tun->readq, skb);
 369         dev->trans_start = jiffies;
 370
 371         /* Notify and wake up reader process */
 372         if (tun->flags & TUN_FASYNC)
 373                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
 374         wake_up_interruptible(&tun->tfile->read_wait);
 375         return 0;
 376
 377 drop:
 378         dev->stats.tx_dropped++;
 379         kfree_skb(skb);
 380         return 0;
 381 }
 382
 383 static void tun_net_mclist(struct net_device *dev)
 384 {
 385         /*
 386          * This callback is supposed to deal with mc filter in
 387          * _rx_ path and has nothing to do with the _tx_ path.
 388          * In rx path we always accept everything userspace gives us.
 389          */
 390         return;
 391 }
 392
 393 #define MIN_MTU 68
 394 #define MAX_MTU 65535
 395
 396 static int
 397 tun_net_change_mtu(struct net_device *dev, int new_mtu)
 398 {
 399         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
 400                 return -EINVAL;
 401         dev->mtu = new_mtu;
 402         return 0;
 403 }
 404
 405 static const struct net_device_ops tun_netdev_ops = {
 406         .ndo_uninit             = tun_net_uninit,
 407         .ndo_open               = tun_net_open,
 408         .ndo_stop               = tun_net_close,
 409         .ndo_start_xmit         = tun_net_xmit,
 410         .ndo_change_mtu         = tun_net_change_mtu,
 411 };
 412
 413 static const struct net_device_ops tap_netdev_ops = {
 414         .ndo_uninit             = tun_net_uninit,
 415         .ndo_open               = tun_net_open,
 416         .ndo_stop               = tun_net_close,
 417         .ndo_start_xmit         = tun_net_xmit,
 418         .ndo_change_mtu         = tun_net_change_mtu,
 419         .ndo_set_multicast_list = tun_net_mclist,
 420         .ndo_set_mac_address    = eth_mac_addr,
 421         .ndo_validate_addr      = eth_validate_addr,
 422 };
 423
 424 /* Initialize net device. */
 425 static void tun_net_init(struct net_device *dev)
 426 {
 427         struct tun_struct *tun = netdev_priv(dev);
 428
 429         switch (tun->flags & TUN_TYPE_MASK) {
 430         case TUN_TUN_DEV:
 431                 dev->netdev_ops = &tun_netdev_ops;
 432
 433                 /* Point-to-Point TUN Device */
 434                 dev->hard_header_len = 0;
 435                 dev->addr_len = 0;
 436                 dev->mtu = 1500;
 437
 438                 /* Zero header length */
 439                 dev->type = ARPHRD_NONE;
 440                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 441                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 442                 break;
 443
 444         case TUN_TAP_DEV:
 445                 dev->netdev_ops = &tap_netdev_ops;
 446                 /* Ethernet TAP Device */
 447                 ether_setup(dev);
 448
 449                 random_ether_addr(dev->dev_addr);
 450
 451                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 452                 break;
 453         }
 454 }
 455
 456 /* Character device part */
 457
 458 /* Poll */
 459 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
 460 {
 461         struct tun_file *tfile = file->private_data;
 462         struct tun_struct *tun = __tun_get(tfile);
 463         unsigned int mask = POLLOUT | POLLWRNORM;
 464
 465         if (!tun)
 466                 return POLLERR;
 467
 468         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
 469
 470         poll_wait(file, &tfile->read_wait, wait);
 471
 472         if (!skb_queue_empty(&tun->readq))
 473                 mask |= POLLIN | POLLRDNORM;
 474
 475         if (tun->dev->reg_state != NETREG_REGISTERED)
 476                 mask = POLLERR;
 477
 478         tun_put(tun);
 479         return mask;
 480 }
 481
 482 /* prepad is the amount to reserve at front.  len is length after that.
 483  * linear is a hint as to how much to copy (usually headers). */
 484 static struct sk_buff *tun_alloc_skb(size_t prepad, size_t len, size_t linear,
 485                                      gfp_t gfp)
 486 {
 487         struct sk_buff *skb;
 488         unsigned int i;
 489
 490         skb = alloc_skb(prepad + len, gfp|__GFP_NOWARN);
 491         if (skb) {
 492                 skb_reserve(skb, prepad);
 493                 skb_put(skb, len);
 494                 return skb;
 495         }
 496
 497         /* Under a page?  Don't bother with paged skb. */
 498         if (prepad + len < PAGE_SIZE)
 499                 return NULL;
 500
 501         /* Start with a normal skb, and add pages. */
 502         skb = alloc_skb(prepad + linear, gfp);
 503         if (!skb)
 504                 return NULL;
 505
 506         skb_reserve(skb, prepad);
 507         skb_put(skb, linear);
 508
 509         len -= linear;
 510
 511         for (i = 0; i < MAX_SKB_FRAGS; i++) {
 512                 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
 513
 514                 f->page = alloc_page(gfp|__GFP_ZERO);
 515                 if (!f->page)
 516                         break;
 517
 518                 f->page_offset = 0;
 519                 f->size = PAGE_SIZE;
 520
 521                 skb->data_len += PAGE_SIZE;
 522                 skb->len += PAGE_SIZE;
 523                 skb->truesize += PAGE_SIZE;
 524                 skb_shinfo(skb)->nr_frags++;
 525
 526                 if (len < PAGE_SIZE) {
 527                         len = 0;
 528                         break;
 529                 }
 530                 len -= PAGE_SIZE;
 531         }
 532
 533         /* Too large, or alloc fail? */
 534         if (unlikely(len)) {
 535                 kfree_skb(skb);
 536                 skb = NULL;
 537         }
 538
 539         return skb;
 540 }
 541
 542 /* Get packet from user space buffer */
 543 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
 544 {
 545         struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
 546         struct sk_buff *skb;
 547         size_t len = count, align = 0;
 548         struct virtio_net_hdr gso = { 0 };
 549
 550         if (!(tun->flags & TUN_NO_PI)) {
 551                 if ((len -= sizeof(pi)) > count)
 552                         return -EINVAL;
 553
 554                 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
 555                         return -EFAULT;
 556         }
 557
 558         if (tun->flags & TUN_VNET_HDR) {
 559                 if ((len -= sizeof(gso)) > count)
 560                         return -EINVAL;
 561
 562                 if (memcpy_fromiovec((void *)&gso, iv, sizeof(gso)))
 563                         return -EFAULT;
 564
 565                 if (gso.hdr_len > len)
 566                         return -EINVAL;
 567         }
 568
 569         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
 570                 align = NET_IP_ALIGN;
 571                 if (unlikely(len < ETH_HLEN))
 572                         return -EINVAL;
 573         }
 574
 575         if (!(skb = tun_alloc_skb(align, len, gso.hdr_len, GFP_KERNEL))) {
 576                 tun->dev->stats.rx_dropped++;
 577                 return -ENOMEM;
 578         }
 579
 580         if (skb_copy_datagram_from_iovec(skb, 0, iv, len)) {
 581                 tun->dev->stats.rx_dropped++;
 582                 kfree_skb(skb);
 583                 return -EFAULT;
 584         }
 585
 586         if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 587                 if (!skb_partial_csum_set(skb, gso.csum_start,
 588                                           gso.csum_offset)) {
 589                         tun->dev->stats.rx_frame_errors++;
 590                         kfree_skb(skb);
 591                         return -EINVAL;
 592                 }
 593         } else if (tun->flags & TUN_NOCHECKSUM)
 594                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 595
 596         switch (tun->flags & TUN_TYPE_MASK) {
 597         case TUN_TUN_DEV:
 598                 if (tun->flags & TUN_NO_PI) {
 599                         switch (skb->data[0] & 0xf0) {
 600                         case 0x40:
 601                                 pi.proto = htons(ETH_P_IP);
 602                                 break;
 603                         case 0x60:
 604                                 pi.proto = htons(ETH_P_IPV6);
 605                                 break;
 606                         default:
 607                                 tun->dev->stats.rx_dropped++;
 608                                 kfree_skb(skb);
 609                                 return -EINVAL;
 610                         }
 611                 }
 612
 613                 skb_reset_mac_header(skb);
 614                 skb->protocol = pi.proto;
 615                 skb->dev = tun->dev;
 616                 break;
 617         case TUN_TAP_DEV:
 618                 skb->protocol = eth_type_trans(skb, tun->dev);
 619                 break;
 620         };
 621
 622         if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 623                 pr_debug("GSO!\n");
 624                 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 625                 case VIRTIO_NET_HDR_GSO_TCPV4:
 626                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
 627                         break;
 628                 case VIRTIO_NET_HDR_GSO_TCPV6:
 629                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 630                         break;
 631                 default:
 632                         tun->dev->stats.rx_frame_errors++;
 633                         kfree_skb(skb);
 634                         return -EINVAL;
 635                 }
 636
 637                 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
 638                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 639
 640                 skb_shinfo(skb)->gso_size = gso.gso_size;
 641                 if (skb_shinfo(skb)->gso_size == 0) {
 642                         tun->dev->stats.rx_frame_errors++;
 643                         kfree_skb(skb);
 644                         return -EINVAL;
 645                 }
 646
 647                 /* Header must be checked, and gso_segs computed. */
 648                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
 649                 skb_shinfo(skb)->gso_segs = 0;
 650         }
 651
 652         netif_rx_ni(skb);
 653
 654         tun->dev->stats.rx_packets++;
 655         tun->dev->stats.rx_bytes += len;
 656
 657         return count;
 658 }
 659
 660 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
 661                               unsigned long count, loff_t pos)
 662 {
 663         struct tun_struct *tun = tun_get(iocb->ki_filp);
 664         ssize_t result;
 665
 666         if (!tun)
 667                 return -EBADFD;
 668
 669         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
 670
 671         result = tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
 672
 673         tun_put(tun);
 674         return result;
 675 }
 676
 677 /* Put packet to the user space buffer */
 678 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
 679                                        struct sk_buff *skb,
 680                                        struct iovec *iv, int len)
 681 {
 682         struct tun_pi pi = { 0, skb->protocol };
 683         ssize_t total = 0;
 684
 685         if (!(tun->flags & TUN_NO_PI)) {
 686                 if ((len -= sizeof(pi)) < 0)
 687                         return -EINVAL;
 688
 689                 if (len < skb->len) {
 690                         /* Packet will be striped */
 691                         pi.flags |= TUN_PKT_STRIP;
 692                 }
 693
 694                 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
 695                         return -EFAULT;
 696                 total += sizeof(pi);
 697         }
 698
 699         if (tun->flags & TUN_VNET_HDR) {
 700                 struct virtio_net_hdr gso = { 0 }; /* no info leak */
 701                 if ((len -= sizeof(gso)) < 0)
 702                         return -EINVAL;
 703
 704                 if (skb_is_gso(skb)) {
 705                         struct skb_shared_info *sinfo = skb_shinfo(skb);
 706
 707                         /* This is a hint as to how much should be linear. */
 708                         gso.hdr_len = skb_headlen(skb);
 709                         gso.gso_size = sinfo->gso_size;
 710                         if (sinfo->gso_type & SKB_GSO_TCPV4)
 711                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 712                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
 713                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 714                         else
 715                                 BUG();
 716                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
 717                                 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 718                 } else
 719                         gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
 720
 721                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
 722                         gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 723                         gso.csum_start = skb->csum_start - skb_headroom(skb);
 724                         gso.csum_offset = skb->csum_offset;
 725                 } /* else everything is zero */
 726
 727                 if (unlikely(memcpy_toiovec(iv, (void *)&gso, sizeof(gso))))
 728                         return -EFAULT;
 729                 total += sizeof(gso);
 730         }
 731
 732         len = min_t(int, skb->len, len);
 733
 734         skb_copy_datagram_iovec(skb, 0, iv, len);
 735         total += len;
 736
 737         tun->dev->stats.tx_packets++;
 738         tun->dev->stats.tx_bytes += len;
 739
 740         return total;
 741 }
 742
 743 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
 744                             unsigned long count, loff_t pos)
 745 {
 746         struct file *file = iocb->ki_filp;
 747         struct tun_file *tfile = file->private_data;
 748         struct tun_struct *tun = __tun_get(tfile);
 749         DECLARE_WAITQUEUE(wait, current);
 750         struct sk_buff *skb;
 751         ssize_t len, ret = 0;
 752
 753         if (!tun)
 754                 return -EBADFD;
 755
 756         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
 757
 758         len = iov_length(iv, count);
 759         if (len < 0) {
 760                 ret = -EINVAL;
 761                 goto out;
 762         }
 763
 764         add_wait_queue(&tfile->read_wait, &wait);
 765         while (len) {
 766                 current->state = TASK_INTERRUPTIBLE;
 767
 768                 /* Read frames from the queue */
 769                 if (!(skb=skb_dequeue(&tun->readq))) {
 770                         if (file->f_flags & O_NONBLOCK) {
 771                                 ret = -EAGAIN;
 772                                 break;
 773                         }
 774                         if (signal_pending(current)) {
 775                                 ret = -ERESTARTSYS;
 776                                 break;
 777                         }
 778                         if (tun->dev->reg_state != NETREG_REGISTERED) {
 779                                 ret = -EIO;
 780                                 break;
 781                         }
 782
 783                         /* Nothing to read, let's sleep */
 784                         schedule();
 785                         continue;
 786                 }
 787                 netif_wake_queue(tun->dev);
 788
 789                 ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
 790                 kfree_skb(skb);
 791                 break;
 792         }
 793
 794         current->state = TASK_RUNNING;
 795         remove_wait_queue(&tfile->read_wait, &wait);
 796
 797 out:
 798         tun_put(tun);
 799         return ret;
 800 }
 801
 802 static void tun_setup(struct net_device *dev)
 803 {
 804         struct tun_struct *tun = netdev_priv(dev);
 805
 806         skb_queue_head_init(&tun->readq);
 807
 808         tun->owner = -1;
 809         tun->group = -1;
 810
 811         dev->ethtool_ops = &tun_ethtool_ops;
 812         dev->destructor = free_netdev;
 813         dev->features |= NETIF_F_NETNS_LOCAL;
 814 }
 815
 816 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 817 {
 818         struct tun_struct *tun;
 819         struct net_device *dev;
 820         int err;
 821
 822         dev = __dev_get_by_name(net, ifr->ifr_name);
 823         if (dev) {
 824                 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
 825                         tun = netdev_priv(dev);
 826                 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
 827                         tun = netdev_priv(dev);
 828                 else
 829                         return -EINVAL;
 830
 831                 err = tun_attach(tun, file);
 832                 if (err < 0)
 833                         return err;
 834         }
 835         else {
 836                 char *name;
 837                 unsigned long flags = 0;
 838
 839                 err = -EINVAL;
 840
 841                 if (!capable(CAP_NET_ADMIN))
 842                         return -EPERM;
 843
 844                 /* Set dev type */
 845                 if (ifr->ifr_flags & IFF_TUN) {
 846                         /* TUN device */
 847                         flags |= TUN_TUN_DEV;
 848                         name = "tun%d";
 849                 } else if (ifr->ifr_flags & IFF_TAP) {
 850                         /* TAP device */
 851                         flags |= TUN_TAP_DEV;
 852                         name = "tap%d";
 853                 } else
 854                         goto failed;
 855
 856                 if (*ifr->ifr_name)
 857                         name = ifr->ifr_name;
 858
 859                 dev = alloc_netdev(sizeof(struct tun_struct), name,
 860                                    tun_setup);
 861                 if (!dev)
 862                         return -ENOMEM;
 863
 864                 dev_net_set(dev, net);
 865
 866                 tun = netdev_priv(dev);
 867                 tun->dev = dev;
 868                 tun->flags = flags;
 869                 tun->txflt.count = 0;
 870
 871                 tun_net_init(dev);
 872
 873                 if (strchr(dev->name, '%')) {
 874                         err = dev_alloc_name(dev, dev->name);
 875                         if (err < 0)
 876                                 goto err_free_dev;
 877                 }
 878
 879                 err = register_netdevice(tun->dev);
 880                 if (err < 0)
 881                         goto err_free_dev;
 882
 883                 err = tun_attach(tun, file);
 884                 if (err < 0)
 885                         goto err_free_dev;
 886         }
 887
 888         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
 889
 890         if (ifr->ifr_flags & IFF_NO_PI)
 891                 tun->flags |= TUN_NO_PI;
 892         else
 893                 tun->flags &= ~TUN_NO_PI;
 894
 895         if (ifr->ifr_flags & IFF_ONE_QUEUE)
 896                 tun->flags |= TUN_ONE_QUEUE;
 897         else
 898                 tun->flags &= ~TUN_ONE_QUEUE;
 899
 900         if (ifr->ifr_flags & IFF_VNET_HDR)
 901                 tun->flags |= TUN_VNET_HDR;
 902         else
 903                 tun->flags &= ~TUN_VNET_HDR;
 904
 905         /* Make sure persistent devices do not get stuck in
 906          * xoff state.
 907          */
 908         if (netif_running(tun->dev))
 909                 netif_wake_queue(tun->dev);
 910
 911         strcpy(ifr->ifr_name, tun->dev->name);
 912         return 0;
 913
 914  err_free_dev:
 915         free_netdev(dev);
 916  failed:
 917         return err;
 918 }
 919
 920 static int tun_get_iff(struct net *net, struct file *file, struct ifreq *ifr)
 921 {
 922         struct tun_struct *tun = tun_get(file);
 923
 924         if (!tun)
 925                 return -EBADFD;
 926
 927         DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);
 928
 929         strcpy(ifr->ifr_name, tun->dev->name);
 930
 931         ifr->ifr_flags = 0;
 932
 933         if (ifr->ifr_flags & TUN_TUN_DEV)
 934                 ifr->ifr_flags |= IFF_TUN;
 935         else
 936                 ifr->ifr_flags |= IFF_TAP;
 937
 938         if (tun->flags & TUN_NO_PI)
 939                 ifr->ifr_flags |= IFF_NO_PI;
 940
 941         if (tun->flags & TUN_ONE_QUEUE)
 942                 ifr->ifr_flags |= IFF_ONE_QUEUE;
 943
 944         if (tun->flags & TUN_VNET_HDR)
 945                 ifr->ifr_flags |= IFF_VNET_HDR;
 946
 947         tun_put(tun);
 948         return 0;
 949 }
 950
 951 /* This is like a cut-down ethtool ops, except done via tun fd so no
 952  * privs required. */
 953 static int set_offload(struct net_device *dev, unsigned long arg)
 954 {
 955         unsigned int old_features, features;
 956
 957         old_features = dev->features;
 958         /* Unset features, set them as we chew on the arg. */
 959         features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
 960                                     |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6));
 961
 962         if (arg & TUN_F_CSUM) {
 963                 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
 964                 arg &= ~TUN_F_CSUM;
 965
 966                 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
 967                         if (arg & TUN_F_TSO_ECN) {
 968                                 features |= NETIF_F_TSO_ECN;
 969                                 arg &= ~TUN_F_TSO_ECN;
 970                         }
 971                         if (arg & TUN_F_TSO4)
 972                                 features |= NETIF_F_TSO;
 973                         if (arg & TUN_F_TSO6)
 974                                 features |= NETIF_F_TSO6;
 975                         arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
 976                 }
 977         }
 978
 979         /* This gives the user a way to test for new features in future by
 980          * trying to set them. */
 981         if (arg)
 982                 return -EINVAL;
 983
 984         dev->features = features;
 985         if (old_features != dev->features)
 986                 netdev_features_change(dev);
 987
 988         return 0;
 989 }
 990
 991 static int tun_chr_ioctl(struct inode *inode, struct file *file,
 992                          unsigned int cmd, unsigned long arg)
 993 {
 994         struct tun_file *tfile = file->private_data;
 995         struct tun_struct *tun;
 996         void __user* argp = (void __user*)arg;
 997         struct ifreq ifr;
 998         int ret;
 999
1000         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1001                 if (copy_from_user(&ifr, argp, sizeof ifr))
1002                         return -EFAULT;
1003
1004         if (cmd == TUNGETFEATURES) {
1005                 /* Currently this just means: "what IFF flags are valid?".
1006                  * This is needed because we never checked for invalid flags on
1007                  * TUNSETIFF. */
1008                 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1009                                 IFF_VNET_HDR,
1010                                 (unsigned int __user*)argp);
1011         }
1012
1013         tun = __tun_get(tfile);
1014         if (cmd == TUNSETIFF && !tun) {
1015                 int err;
1016
1017                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1018
1019                 rtnl_lock();
1020                 err = tun_set_iff(tfile->net, file, &ifr);
1021                 rtnl_unlock();
1022
1023                 if (err)
1024                         return err;
1025
1026                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
1027                         return -EFAULT;
1028                 return 0;
1029         }
1030
1031
1032         if (!tun)
1033                 return -EBADFD;
1034
1035         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
1036
1037         ret = 0;
1038         switch (cmd) {
1039         case TUNGETIFF:
1040                 ret = tun_get_iff(current->nsproxy->net_ns, file, &ifr);
1041                 if (ret)
1042                         break;
1043
1044                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
1045                         ret = -EFAULT;
1046                 break;
1047
1048         case TUNSETNOCSUM:
1049                 /* Disable/Enable checksum */
1050                 if (arg)
1051                         tun->flags |= TUN_NOCHECKSUM;
1052                 else
1053                         tun->flags &= ~TUN_NOCHECKSUM;
1054
1055                 DBG(KERN_INFO "%s: checksum %s\n",
1056                     tun->dev->name, arg ? "disabled" : "enabled");
1057                 break;
1058
1059         case TUNSETPERSIST:
1060                 /* Disable/Enable persist mode */
1061                 if (arg)
1062                         tun->flags |= TUN_PERSIST;
1063                 else
1064                         tun->flags &= ~TUN_PERSIST;
1065
1066                 DBG(KERN_INFO "%s: persist %s\n",
1067                     tun->dev->name, arg ? "enabled" : "disabled");
1068                 break;
1069
1070         case TUNSETOWNER:
1071                 /* Set owner of the device */
1072                 tun->owner = (uid_t) arg;
1073
1074                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
1075                 break;
1076
1077         case TUNSETGROUP:
1078                 /* Set group of the device */
1079                 tun->group= (gid_t) arg;
1080
1081                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
1082                 break;
1083
1084         case TUNSETLINK:
1085                 /* Only allow setting the type when the interface is down */
1086                 rtnl_lock();
1087                 if (tun->dev->flags & IFF_UP) {
1088                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
1089                                 tun->dev->name);
1090                         ret = -EBUSY;
1091                 } else {
1092                         tun->dev->type = (int) arg;
1093                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
1094                         ret = 0;
1095                 }
1096                 rtnl_unlock();
1097                 break;
1098
1099 #ifdef TUN_DEBUG
1100         case TUNSETDEBUG:
1101                 tun->debug = arg;
1102                 break;
1103 #endif
1104         case TUNSETOFFLOAD:
1105                 rtnl_lock();
1106                 ret = set_offload(tun->dev, arg);
1107                 rtnl_unlock();
1108                 break;
1109
1110         case TUNSETTXFILTER:
1111                 /* Can be set only for TAPs */
1112                 ret = -EINVAL;
1113                 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1114                         break;
1115                 rtnl_lock();
1116                 ret = update_filter(&tun->txflt, (void __user *)arg);
1117                 rtnl_unlock();
1118                 break;
1119
1120         case SIOCGIFHWADDR:
1121                 /* Get hw addres */
1122                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1123                 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1124                 if (copy_to_user(argp, &ifr, sizeof ifr))
1125                         ret = -EFAULT;
1126                 break;
1127
1128         case SIOCSIFHWADDR:
1129                 /* Set hw address */
1130                 DBG(KERN_DEBUG "%s: set hw address: %pM\n",
1131                         tun->dev->name, ifr.ifr_hwaddr.sa_data);
1132
1133                 rtnl_lock();
1134                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1135                 rtnl_unlock();
1136                 break;
1137         default:
1138                 ret = -EINVAL;
1139                 break;
1140         };
1141
1142         tun_put(tun);
1143         return ret;
1144 }
1145
1146 static int tun_chr_fasync(int fd, struct file *file, int on)
1147 {
1148         struct tun_struct *tun = tun_get(file);
1149         int ret;
1150
1151         if (!tun)
1152                 return -EBADFD;
1153
1154         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
1155
1156         lock_kernel();
1157         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1158                 goto out;
1159
1160         if (on) {
1161                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1162                 if (ret)
1163                         goto out;
1164                 tun->flags |= TUN_FASYNC;
1165         } else
1166                 tun->flags &= ~TUN_FASYNC;
1167         ret = 0;
1168 out:
1169         unlock_kernel();
1170         tun_put(tun);
1171         return ret;
1172 }
1173
1174 static int tun_chr_open(struct inode *inode, struct file * file)
1175 {
1176         struct tun_file *tfile;
1177         cycle_kernel_lock();
1178         DBG1(KERN_INFO "tunX: tun_chr_open\n");
1179
1180         tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1181         if (!tfile)
1182                 return -ENOMEM;
1183         atomic_set(&tfile->count, 0);
1184         tfile->tun = NULL;
1185         tfile->net = get_net(current->nsproxy->net_ns);
1186         init_waitqueue_head(&tfile->read_wait);
1187         file->private_data = tfile;
1188         return 0;
1189 }
1190
1191 static int tun_chr_close(struct inode *inode, struct file *file)
1192 {
1193         struct tun_file *tfile = file->private_data;
1194         struct tun_struct *tun = __tun_get(tfile);
1195
1196
1197         if (tun) {
1198                 DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
1199
1200                 rtnl_lock();
1201                 __tun_detach(tun);
1202
1203                 /* If desireable, unregister the netdevice. */
1204                 if (!(tun->flags & TUN_PERSIST))
1205                         unregister_netdevice(tun->dev);
1206
1207                 rtnl_unlock();
1208         }
1209
1210         put_net(tfile->net);
1211         kfree(tfile);
1212
1213         return 0;
1214 }
1215
1216 static const struct file_operations tun_fops = {
1217         .owner  = THIS_MODULE,
1218         .llseek = no_llseek,
1219         .read  = do_sync_read,
1220         .aio_read  = tun_chr_aio_read,
1221         .write = do_sync_write,
1222         .aio_write = tun_chr_aio_write,
1223         .poll   = tun_chr_poll,
1224         .ioctl  = tun_chr_ioctl,
1225         .open   = tun_chr_open,
1226         .release = tun_chr_close,
1227         .fasync = tun_chr_fasync
1228 };
1229
1230 static struct miscdevice tun_miscdev = {
1231         .minor = TUN_MINOR,
1232         .name = "tun",
1233         .fops = &tun_fops,
1234 };
1235
1236 /* ethtool interface */
1237
1238 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1239 {
1240         cmd->supported          = 0;
1241         cmd->advertising        = 0;
1242         cmd->speed              = SPEED_10;
1243         cmd->duplex             = DUPLEX_FULL;
1244         cmd->port               = PORT_TP;
1245         cmd->phy_address        = 0;
1246         cmd->transceiver        = XCVR_INTERNAL;
1247         cmd->autoneg            = AUTONEG_DISABLE;
1248         cmd->maxtxpkt           = 0;
1249         cmd->maxrxpkt           = 0;
1250         return 0;
1251 }
1252
1253 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1254 {
1255         struct tun_struct *tun = netdev_priv(dev);
1256
1257         strcpy(info->driver, DRV_NAME);
1258         strcpy(info->version, DRV_VERSION);
1259         strcpy(info->fw_version, "N/A");
1260
1261         switch (tun->flags & TUN_TYPE_MASK) {
1262         case TUN_TUN_DEV:
1263                 strcpy(info->bus_info, "tun");
1264                 break;
1265         case TUN_TAP_DEV:
1266                 strcpy(info->bus_info, "tap");
1267                 break;
1268         }
1269 }
1270
1271 static u32 tun_get_msglevel(struct net_device *dev)
1272 {
1273 #ifdef TUN_DEBUG
1274         struct tun_struct *tun = netdev_priv(dev);
1275         return tun->debug;
1276 #else
1277         return -EOPNOTSUPP;
1278 #endif
1279 }
1280
1281 static void tun_set_msglevel(struct net_device *dev, u32 value)
1282 {
1283 #ifdef TUN_DEBUG
1284         struct tun_struct *tun = netdev_priv(dev);
1285         tun->debug = value;
1286 #endif
1287 }
1288
1289 static u32 tun_get_link(struct net_device *dev)
1290 {
1291         struct tun_struct *tun = netdev_priv(dev);
1292         return !!tun->tfile;
1293 }
1294
1295 static u32 tun_get_rx_csum(struct net_device *dev)
1296 {
1297         struct tun_struct *tun = netdev_priv(dev);
1298         return (tun->flags & TUN_NOCHECKSUM) == 0;
1299 }
1300
1301 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1302 {
1303         struct tun_struct *tun = netdev_priv(dev);
1304         if (data)
1305                 tun->flags &= ~TUN_NOCHECKSUM;
1306         else
1307                 tun->flags |= TUN_NOCHECKSUM;
1308         return 0;
1309 }
1310
1311 static const struct ethtool_ops tun_ethtool_ops = {
1312         .get_settings   = tun_get_settings,
1313         .get_drvinfo    = tun_get_drvinfo,
1314         .get_msglevel   = tun_get_msglevel,
1315         .set_msglevel   = tun_set_msglevel,
1316         .get_link       = tun_get_link,
1317         .get_rx_csum    = tun_get_rx_csum,
1318         .set_rx_csum    = tun_set_rx_csum
1319 };
1320
1321 static int tun_init_net(struct net *net)
1322 {
1323         return 0;
1324 }
1325
1326 static void tun_exit_net(struct net *net)
1327 {
1328         struct net_device *dev, *next;
1329
1330         rtnl_lock();
1331         for_each_netdev_safe(net, dev, next) {
1332                 if (dev->ethtool_ops != &tun_ethtool_ops)
1333                         continue;
1334                 DBG(KERN_INFO "%s cleaned up\n", dev->name);
1335                 unregister_netdevice(dev);
1336         }
1337         rtnl_unlock();
1338 }
1339
1340 static struct pernet_operations tun_net_ops = {
1341         .init = tun_init_net,
1342         .exit = tun_exit_net,
1343 };
1344
1345 static int __init tun_init(void)
1346 {
1347         int ret = 0;
1348
1349         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1350         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1351
1352         ret = register_pernet_device(&tun_net_ops);
1353         if (ret) {
1354                 printk(KERN_ERR "tun: Can't register pernet ops\n");
1355                 goto err_pernet;
1356         }
1357
1358         ret = misc_register(&tun_miscdev);
1359         if (ret) {
1360                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1361                 goto err_misc;
1362         }
1363         return 0;
1364
1365 err_misc:
1366         unregister_pernet_device(&tun_net_ops);
1367 err_pernet:
1368         return ret;
1369 }
1370
1371 static void tun_cleanup(void)
1372 {
1373         misc_deregister(&tun_miscdev);
1374         unregister_pernet_device(&tun_net_ops);
1375 }
1376
1377 module_init(tun_init);
1378 module_exit(tun_cleanup);
1379 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1380 MODULE_AUTHOR(DRV_COPYRIGHT);
1381 MODULE_LICENSE("GPL");
1382 MODULE_ALIAS_MISCDEV(TUN_MINOR);