drivers/net/tun.c

   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 #include <net/rtnetlink.h>
  67 #include <net/sock.h>
  68
  69 #include <asm/system.h>
  70 #include <asm/uaccess.h>
  71
  72 /* Uncomment to enable debugging */
  73 /* #define TUN_DEBUG 1 */
  74
  75 #ifdef TUN_DEBUG
  76 static int debug;
  77
  78 #define DBG  if(tun->debug)printk
  79 #define DBG1 if(debug==2)printk
  80 #else
  81 #define DBG( a... )
  82 #define DBG1( a... )
  83 #endif
  84
  85 #define FLT_EXACT_COUNT 8
  86 struct tap_filter {
  87         unsigned int    count;    /* Number of addrs. Zero means disabled */
  88         u32             mask[2];  /* Mask of the hashed addrs */
  89         unsigned char   addr[FLT_EXACT_COUNT][ETH_ALEN];
  90 };
  91
  92 struct tun_file {
  93         atomic_t count;
  94         struct tun_struct *tun;
  95         struct net *net;
  96 };
  97
  98 struct tun_sock;
  99
 100 struct tun_struct {
 101         struct tun_file         *tfile;
 102         unsigned int            flags;
 103         uid_t                   owner;
 104         gid_t                   group;
 105
 106         struct net_device       *dev;
 107         struct fasync_struct    *fasync;
 108
 109         struct tap_filter       txflt;
 110         struct socket           socket;
 111
 112 #ifdef TUN_DEBUG
 113         int debug;
 114 #endif
 115 };
 116
 117 struct tun_sock {
 118         struct sock             sk;
 119         struct tun_struct       *tun;
 120 };
 121
 122 static inline struct tun_sock *tun_sk(struct sock *sk)
 123 {
 124         return container_of(sk, struct tun_sock, sk);
 125 }
 126
 127 static int tun_attach(struct tun_struct *tun, struct file *file)
 128 {
 129         struct tun_file *tfile = file->private_data;
 130         int err;
 131
 132         ASSERT_RTNL();
 133
 134         netif_tx_lock_bh(tun->dev);
 135
 136         err = -EINVAL;
 137         if (tfile->tun)
 138                 goto out;
 139
 140         err = -EBUSY;
 141         if (tun->tfile)
 142                 goto out;
 143
 144         err = 0;
 145         tfile->tun = tun;
 146         tun->tfile = tfile;
 147         dev_hold(tun->dev);
 148         sock_hold(tun->socket.sk);
 149         atomic_inc(&tfile->count);
 150
 151 out:
 152         netif_tx_unlock_bh(tun->dev);
 153         return err;
 154 }
 155
 156 static void __tun_detach(struct tun_struct *tun)
 157 {
 158         /* Detach from net device */
 159         netif_tx_lock_bh(tun->dev);
 160         tun->tfile = NULL;
 161         netif_tx_unlock_bh(tun->dev);
 162
 163         /* Drop read queue */
 164         skb_queue_purge(&tun->socket.sk->sk_receive_queue);
 165
 166         /* Drop the extra count on the net device */
 167         dev_put(tun->dev);
 168 }
 169
 170 static void tun_detach(struct tun_struct *tun)
 171 {
 172         rtnl_lock();
 173         __tun_detach(tun);
 174         rtnl_unlock();
 175 }
 176
 177 static struct tun_struct *__tun_get(struct tun_file *tfile)
 178 {
 179         struct tun_struct *tun = NULL;
 180
 181         if (atomic_inc_not_zero(&tfile->count))
 182                 tun = tfile->tun;
 183
 184         return tun;
 185 }
 186
 187 static struct tun_struct *tun_get(struct file *file)
 188 {
 189         return __tun_get(file->private_data);
 190 }
 191
 192 static void tun_put(struct tun_struct *tun)
 193 {
 194         struct tun_file *tfile = tun->tfile;
 195
 196         if (atomic_dec_and_test(&tfile->count))
 197                 tun_detach(tfile->tun);
 198 }
 199
 200 /* TAP filterting */
 201 static void addr_hash_set(u32 *mask, const u8 *addr)
 202 {
 203         int n = ether_crc(ETH_ALEN, addr) >> 26;
 204         mask[n >> 5] |= (1 << (n & 31));
 205 }
 206
 207 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
 208 {
 209         int n = ether_crc(ETH_ALEN, addr) >> 26;
 210         return mask[n >> 5] & (1 << (n & 31));
 211 }
 212
 213 static int update_filter(struct tap_filter *filter, void __user *arg)
 214 {
 215         struct { u8 u[ETH_ALEN]; } *addr;
 216         struct tun_filter uf;
 217         int err, alen, n, nexact;
 218
 219         if (copy_from_user(&uf, arg, sizeof(uf)))
 220                 return -EFAULT;
 221
 222         if (!uf.count) {
 223                 /* Disabled */
 224                 filter->count = 0;
 225                 return 0;
 226         }
 227
 228         alen = ETH_ALEN * uf.count;
 229         addr = kmalloc(alen, GFP_KERNEL);
 230         if (!addr)
 231                 return -ENOMEM;
 232
 233         if (copy_from_user(addr, arg + sizeof(uf), alen)) {
 234                 err = -EFAULT;
 235                 goto done;
 236         }
 237
 238         /* The filter is updated without holding any locks. Which is
 239          * perfectly safe. We disable it first and in the worst
 240          * case we'll accept a few undesired packets. */
 241         filter->count = 0;
 242         wmb();
 243
 244         /* Use first set of addresses as an exact filter */
 245         for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
 246                 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
 247
 248         nexact = n;
 249
 250         /* Remaining multicast addresses are hashed,
 251          * unicast will leave the filter disabled. */
 252         memset(filter->mask, 0, sizeof(filter->mask));
 253         for (; n < uf.count; n++) {
 254                 if (!is_multicast_ether_addr(addr[n].u)) {
 255                         err = 0; /* no filter */
 256                         goto done;
 257                 }
 258                 addr_hash_set(filter->mask, addr[n].u);
 259         }
 260
 261         /* For ALLMULTI just set the mask to all ones.
 262          * This overrides the mask populated above. */
 263         if ((uf.flags & TUN_FLT_ALLMULTI))
 264                 memset(filter->mask, ~0, sizeof(filter->mask));
 265
 266         /* Now enable the filter */
 267         wmb();
 268         filter->count = nexact;
 269
 270         /* Return the number of exact filters */
 271         err = nexact;
 272
 273 done:
 274         kfree(addr);
 275         return err;
 276 }
 277
 278 /* Returns: 0 - drop, !=0 - accept */
 279 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
 280 {
 281         /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
 282          * at this point. */
 283         struct ethhdr *eh = (struct ethhdr *) skb->data;
 284         int i;
 285
 286         /* Exact match */
 287         for (i = 0; i < filter->count; i++)
 288                 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
 289                         return 1;
 290
 291         /* Inexact match (multicast only) */
 292         if (is_multicast_ether_addr(eh->h_dest))
 293                 return addr_hash_test(filter->mask, eh->h_dest);
 294
 295         return 0;
 296 }
 297
 298 /*
 299  * Checks whether the packet is accepted or not.
 300  * Returns: 0 - drop, !=0 - accept
 301  */
 302 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
 303 {
 304         if (!filter->count)
 305                 return 1;
 306
 307         return run_filter(filter, skb);
 308 }
 309
 310 /* Network device part of the driver */
 311
 312 static const struct ethtool_ops tun_ethtool_ops;
 313
 314 /* Net device detach from fd. */
 315 static void tun_net_uninit(struct net_device *dev)
 316 {
 317         struct tun_struct *tun = netdev_priv(dev);
 318         struct tun_file *tfile = tun->tfile;
 319
 320         /* Inform the methods they need to stop using the dev.
 321          */
 322         if (tfile) {
 323                 wake_up_all(&tun->socket.wait);
 324                 if (atomic_dec_and_test(&tfile->count))
 325                         __tun_detach(tun);
 326         }
 327 }
 328
 329 static void tun_free_netdev(struct net_device *dev)
 330 {
 331         struct tun_struct *tun = netdev_priv(dev);
 332
 333         sock_put(tun->socket.sk);
 334 }
 335
 336 /* Net device open. */
 337 static int tun_net_open(struct net_device *dev)
 338 {
 339         netif_start_queue(dev);
 340         return 0;
 341 }
 342
 343 /* Net device close. */
 344 static int tun_net_close(struct net_device *dev)
 345 {
 346         netif_stop_queue(dev);
 347         return 0;
 348 }
 349
 350 /* Net device start xmit */
 351 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 352 {
 353         struct tun_struct *tun = netdev_priv(dev);
 354
 355         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
 356
 357         /* Drop packet if interface is not attached */
 358         if (!tun->tfile)
 359                 goto drop;
 360
 361         /* Drop if the filter does not like it.
 362          * This is a noop if the filter is disabled.
 363          * Filter can be enabled only for the TAP devices. */
 364         if (!check_filter(&tun->txflt, skb))
 365                 goto drop;
 366
 367         if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
 368                 if (!(tun->flags & TUN_ONE_QUEUE)) {
 369                         /* Normal queueing mode. */
 370                         /* Packet scheduler handles dropping of further packets. */
 371                         netif_stop_queue(dev);
 372
 373                         /* We won't see all dropped packets individually, so overrun
 374                          * error is more appropriate. */
 375                         dev->stats.tx_fifo_errors++;
 376                 } else {
 377                         /* Single queue mode.
 378                          * Driver handles dropping of all packets itself. */
 379                         goto drop;
 380                 }
 381         }
 382
 383         /* Enqueue packet */
 384         skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
 385         dev->trans_start = jiffies;
 386
 387         /* Notify and wake up reader process */
 388         if (tun->flags & TUN_FASYNC)
 389                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
 390         wake_up_interruptible(&tun->socket.wait);
 391         return NETDEV_TX_OK;
 392
 393 drop:
 394         dev->stats.tx_dropped++;
 395         kfree_skb(skb);
 396         return NETDEV_TX_OK;
 397 }
 398
 399 static void tun_net_mclist(struct net_device *dev)
 400 {
 401         /*
 402          * This callback is supposed to deal with mc filter in
 403          * _rx_ path and has nothing to do with the _tx_ path.
 404          * In rx path we always accept everything userspace gives us.
 405          */
 406         return;
 407 }
 408
 409 #define MIN_MTU 68
 410 #define MAX_MTU 65535
 411
 412 static int
 413 tun_net_change_mtu(struct net_device *dev, int new_mtu)
 414 {
 415         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
 416                 return -EINVAL;
 417         dev->mtu = new_mtu;
 418         return 0;
 419 }
 420
 421 static const struct net_device_ops tun_netdev_ops = {
 422         .ndo_uninit             = tun_net_uninit,
 423         .ndo_open               = tun_net_open,
 424         .ndo_stop               = tun_net_close,
 425         .ndo_start_xmit         = tun_net_xmit,
 426         .ndo_change_mtu         = tun_net_change_mtu,
 427 };
 428
 429 static const struct net_device_ops tap_netdev_ops = {
 430         .ndo_uninit             = tun_net_uninit,
 431         .ndo_open               = tun_net_open,
 432         .ndo_stop               = tun_net_close,
 433         .ndo_start_xmit         = tun_net_xmit,
 434         .ndo_change_mtu         = tun_net_change_mtu,
 435         .ndo_set_multicast_list = tun_net_mclist,
 436         .ndo_set_mac_address    = eth_mac_addr,
 437         .ndo_validate_addr      = eth_validate_addr,
 438 };
 439
 440 /* Initialize net device. */
 441 static void tun_net_init(struct net_device *dev)
 442 {
 443         struct tun_struct *tun = netdev_priv(dev);
 444
 445         switch (tun->flags & TUN_TYPE_MASK) {
 446         case TUN_TUN_DEV:
 447                 dev->netdev_ops = &tun_netdev_ops;
 448
 449                 /* Point-to-Point TUN Device */
 450                 dev->hard_header_len = 0;
 451                 dev->addr_len = 0;
 452                 dev->mtu = 1500;
 453
 454                 /* Zero header length */
 455                 dev->type = ARPHRD_NONE;
 456                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 457                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 458                 break;
 459
 460         case TUN_TAP_DEV:
 461                 dev->netdev_ops = &tap_netdev_ops;
 462                 /* Ethernet TAP Device */
 463                 ether_setup(dev);
 464
 465                 random_ether_addr(dev->dev_addr);
 466
 467                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 468                 break;
 469         }
 470 }
 471
 472 /* Character device part */
 473
 474 /* Poll */
 475 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
 476 {
 477         struct tun_file *tfile = file->private_data;
 478         struct tun_struct *tun = __tun_get(tfile);
 479         struct sock *sk;
 480         unsigned int mask = 0;
 481
 482         if (!tun)
 483                 return POLLERR;
 484
 485         sk = tun->socket.sk;
 486
 487         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
 488
 489         poll_wait(file, &tun->socket.wait, wait);
 490
 491         if (!skb_queue_empty(&sk->sk_receive_queue))
 492                 mask |= POLLIN | POLLRDNORM;
 493
 494         if (sock_writeable(sk) ||
 495             (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
 496              sock_writeable(sk)))
 497                 mask |= POLLOUT | POLLWRNORM;
 498
 499         if (tun->dev->reg_state != NETREG_REGISTERED)
 500                 mask = POLLERR;
 501
 502         tun_put(tun);
 503         return mask;
 504 }
 505
 506 /* prepad is the amount to reserve at front.  len is length after that.
 507  * linear is a hint as to how much to copy (usually headers). */
 508 static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
 509                                             size_t prepad, size_t len,
 510                                             size_t linear, int noblock)
 511 {
 512         struct sock *sk = tun->socket.sk;
 513         struct sk_buff *skb;
 514         int err;
 515
 516         /* Under a page?  Don't bother with paged skb. */
 517         if (prepad + len < PAGE_SIZE || !linear)
 518                 linear = len;
 519
 520         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
 521                                    &err);
 522         if (!skb)
 523                 return ERR_PTR(err);
 524
 525         skb_reserve(skb, prepad);
 526         skb_put(skb, linear);
 527         skb->data_len = len - linear;
 528         skb->len += len - linear;
 529
 530         return skb;
 531 }
 532
 533 /* Get packet from user space buffer */
 534 static __inline__ ssize_t tun_get_user(struct tun_struct *tun,
 535                                        const struct iovec *iv, size_t count,
 536                                        int noblock)
 537 {
 538         struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
 539         struct sk_buff *skb;
 540         size_t len = count, align = 0;
 541         struct virtio_net_hdr gso = { 0 };
 542         int offset = 0;
 543
 544         if (!(tun->flags & TUN_NO_PI)) {
 545                 if ((len -= sizeof(pi)) > count)
 546                         return -EINVAL;
 547
 548                 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
 549                         return -EFAULT;
 550                 offset += sizeof(pi);
 551         }
 552
 553         if (tun->flags & TUN_VNET_HDR) {
 554                 if ((len -= sizeof(gso)) > count)
 555                         return -EINVAL;
 556
 557                 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
 558                         return -EFAULT;
 559
 560                 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
 561                     gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
 562                         gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
 563
 564                 if (gso.hdr_len > len)
 565                         return -EINVAL;
 566                 offset += sizeof(gso);
 567         }
 568
 569         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
 570                 align = NET_IP_ALIGN;
 571                 if (unlikely(len < ETH_HLEN ||
 572                              (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
 573                         return -EINVAL;
 574         }
 575
 576         skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
 577         if (IS_ERR(skb)) {
 578                 if (PTR_ERR(skb) != -EAGAIN)
 579                         tun->dev->stats.rx_dropped++;
 580                 return PTR_ERR(skb);
 581         }
 582
 583         if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
 584                 tun->dev->stats.rx_dropped++;
 585                 kfree_skb(skb);
 586                 return -EFAULT;
 587         }
 588
 589         if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 590                 if (!skb_partial_csum_set(skb, gso.csum_start,
 591                                           gso.csum_offset)) {
 592                         tun->dev->stats.rx_frame_errors++;
 593                         kfree_skb(skb);
 594                         return -EINVAL;
 595                 }
 596         } else if (tun->flags & TUN_NOCHECKSUM)
 597                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 598
 599         switch (tun->flags & TUN_TYPE_MASK) {
 600         case TUN_TUN_DEV:
 601                 if (tun->flags & TUN_NO_PI) {
 602                         switch (skb->data[0] & 0xf0) {
 603                         case 0x40:
 604                                 pi.proto = htons(ETH_P_IP);
 605                                 break;
 606                         case 0x60:
 607                                 pi.proto = htons(ETH_P_IPV6);
 608                                 break;
 609                         default:
 610                                 tun->dev->stats.rx_dropped++;
 611                                 kfree_skb(skb);
 612                                 return -EINVAL;
 613                         }
 614                 }
 615
 616                 skb_reset_mac_header(skb);
 617                 skb->protocol = pi.proto;
 618                 skb->dev = tun->dev;
 619                 break;
 620         case TUN_TAP_DEV:
 621                 skb->protocol = eth_type_trans(skb, tun->dev);
 622                 break;
 623         };
 624
 625         if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 626                 pr_debug("GSO!\n");
 627                 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 628                 case VIRTIO_NET_HDR_GSO_TCPV4:
 629                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
 630                         break;
 631                 case VIRTIO_NET_HDR_GSO_TCPV6:
 632                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 633                         break;
 634                 case VIRTIO_NET_HDR_GSO_UDP:
 635                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 636                         break;
 637                 default:
 638                         tun->dev->stats.rx_frame_errors++;
 639                         kfree_skb(skb);
 640                         return -EINVAL;
 641                 }
 642
 643                 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
 644                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 645
 646                 skb_shinfo(skb)->gso_size = gso.gso_size;
 647                 if (skb_shinfo(skb)->gso_size == 0) {
 648                         tun->dev->stats.rx_frame_errors++;
 649                         kfree_skb(skb);
 650                         return -EINVAL;
 651                 }
 652
 653                 /* Header must be checked, and gso_segs computed. */
 654                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
 655                 skb_shinfo(skb)->gso_segs = 0;
 656         }
 657
 658         netif_rx_ni(skb);
 659
 660         tun->dev->stats.rx_packets++;
 661         tun->dev->stats.rx_bytes += len;
 662
 663         return count;
 664 }
 665
 666 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
 667                               unsigned long count, loff_t pos)
 668 {
 669         struct file *file = iocb->ki_filp;
 670         struct tun_struct *tun = tun_get(file);
 671         ssize_t result;
 672
 673         if (!tun)
 674                 return -EBADFD;
 675
 676         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
 677
 678         result = tun_get_user(tun, iv, iov_length(iv, count),
 679                               file->f_flags & O_NONBLOCK);
 680
 681         tun_put(tun);
 682         return result;
 683 }
 684
 685 /* Put packet to the user space buffer */
 686 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
 687                                        struct sk_buff *skb,
 688                                        const struct iovec *iv, int len)
 689 {
 690         struct tun_pi pi = { 0, skb->protocol };
 691         ssize_t total = 0;
 692
 693         if (!(tun->flags & TUN_NO_PI)) {
 694                 if ((len -= sizeof(pi)) < 0)
 695                         return -EINVAL;
 696
 697                 if (len < skb->len) {
 698                         /* Packet will be striped */
 699                         pi.flags |= TUN_PKT_STRIP;
 700                 }
 701
 702                 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
 703                         return -EFAULT;
 704                 total += sizeof(pi);
 705         }
 706
 707         if (tun->flags & TUN_VNET_HDR) {
 708                 struct virtio_net_hdr gso = { 0 }; /* no info leak */
 709                 if ((len -= sizeof(gso)) < 0)
 710                         return -EINVAL;
 711
 712                 if (skb_is_gso(skb)) {
 713                         struct skb_shared_info *sinfo = skb_shinfo(skb);
 714
 715                         /* This is a hint as to how much should be linear. */
 716                         gso.hdr_len = skb_headlen(skb);
 717                         gso.gso_size = sinfo->gso_size;
 718                         if (sinfo->gso_type & SKB_GSO_TCPV4)
 719                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 720                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
 721                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 722                         else if (sinfo->gso_type & SKB_GSO_UDP)
 723                                 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
 724                         else
 725                                 BUG();
 726                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
 727                                 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 728                 } else
 729                         gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
 730
 731                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
 732                         gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 733                         gso.csum_start = skb->csum_start - skb_headroom(skb);
 734                         gso.csum_offset = skb->csum_offset;
 735                 } /* else everything is zero */
 736
 737                 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
 738                                                sizeof(gso))))
 739                         return -EFAULT;
 740                 total += sizeof(gso);
 741         }
 742
 743         len = min_t(int, skb->len, len);
 744
 745         skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
 746         total += len;
 747
 748         tun->dev->stats.tx_packets++;
 749         tun->dev->stats.tx_bytes += len;
 750
 751         return total;
 752 }
 753
 754 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
 755                             unsigned long count, loff_t pos)
 756 {
 757         struct file *file = iocb->ki_filp;
 758         struct tun_file *tfile = file->private_data;
 759         struct tun_struct *tun = __tun_get(tfile);
 760         DECLARE_WAITQUEUE(wait, current);
 761         struct sk_buff *skb;
 762         ssize_t len, ret = 0;
 763
 764         if (!tun)
 765                 return -EBADFD;
 766
 767         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
 768
 769         len = iov_length(iv, count);
 770         if (len < 0) {
 771                 ret = -EINVAL;
 772                 goto out;
 773         }
 774
 775         add_wait_queue(&tun->socket.wait, &wait);
 776         while (len) {
 777                 current->state = TASK_INTERRUPTIBLE;
 778
 779                 /* Read frames from the queue */
 780                 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
 781                         if (file->f_flags & O_NONBLOCK) {
 782                                 ret = -EAGAIN;
 783                                 break;
 784                         }
 785                         if (signal_pending(current)) {
 786                                 ret = -ERESTARTSYS;
 787                                 break;
 788                         }
 789                         if (tun->dev->reg_state != NETREG_REGISTERED) {
 790                                 ret = -EIO;
 791                                 break;
 792                         }
 793
 794                         /* Nothing to read, let's sleep */
 795                         schedule();
 796                         continue;
 797                 }
 798                 netif_wake_queue(tun->dev);
 799
 800                 ret = tun_put_user(tun, skb, iv, len);
 801                 kfree_skb(skb);
 802                 break;
 803         }
 804
 805         current->state = TASK_RUNNING;
 806         remove_wait_queue(&tun->socket.wait, &wait);
 807
 808 out:
 809         tun_put(tun);
 810         return ret;
 811 }
 812
 813 static void tun_setup(struct net_device *dev)
 814 {
 815         struct tun_struct *tun = netdev_priv(dev);
 816
 817         tun->owner = -1;
 818         tun->group = -1;
 819
 820         dev->ethtool_ops = &tun_ethtool_ops;
 821         dev->destructor = tun_free_netdev;
 822 }
 823
 824 /* Trivial set of netlink ops to allow deleting tun or tap
 825  * device with netlink.
 826  */
 827 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
 828 {
 829         return -EINVAL;
 830 }
 831
 832 static struct rtnl_link_ops tun_link_ops __read_mostly = {
 833         .kind           = DRV_NAME,
 834         .priv_size      = sizeof(struct tun_struct),
 835         .setup          = tun_setup,
 836         .validate       = tun_validate,
 837 };
 838
 839 static void tun_sock_write_space(struct sock *sk)
 840 {
 841         struct tun_struct *tun;
 842
 843         if (!sock_writeable(sk))
 844                 return;
 845
 846         if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
 847                 return;
 848
 849         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
 850                 wake_up_interruptible_sync(sk->sk_sleep);
 851
 852         tun = container_of(sk, struct tun_sock, sk)->tun;
 853         kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
 854 }
 855
 856 static void tun_sock_destruct(struct sock *sk)
 857 {
 858         free_netdev(container_of(sk, struct tun_sock, sk)->tun->dev);
 859 }
 860
 861 static struct proto tun_proto = {
 862         .name           = "tun",
 863         .owner          = THIS_MODULE,
 864         .obj_size       = sizeof(struct tun_sock),
 865 };
 866
 867 static int tun_flags(struct tun_struct *tun)
 868 {
 869         int flags = 0;
 870
 871         if (tun->flags & TUN_TUN_DEV)
 872                 flags |= IFF_TUN;
 873         else
 874                 flags |= IFF_TAP;
 875
 876         if (tun->flags & TUN_NO_PI)
 877                 flags |= IFF_NO_PI;
 878
 879         if (tun->flags & TUN_ONE_QUEUE)
 880                 flags |= IFF_ONE_QUEUE;
 881
 882         if (tun->flags & TUN_VNET_HDR)
 883                 flags |= IFF_VNET_HDR;
 884
 885         return flags;
 886 }
 887
 888 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
 889                               char *buf)
 890 {
 891         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
 892         return sprintf(buf, "0x%x\n", tun_flags(tun));
 893 }
 894
 895 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
 896                               char *buf)
 897 {
 898         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
 899         return sprintf(buf, "%d\n", tun->owner);
 900 }
 901
 902 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
 903                               char *buf)
 904 {
 905         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
 906         return sprintf(buf, "%d\n", tun->group);
 907 }
 908
 909 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
 910 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
 911 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
 912
 913 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 914 {
 915         struct sock *sk;
 916         struct tun_struct *tun;
 917         struct net_device *dev;
 918         int err;
 919
 920         dev = __dev_get_by_name(net, ifr->ifr_name);
 921         if (dev) {
 922                 const struct cred *cred = current_cred();
 923
 924                 if (ifr->ifr_flags & IFF_TUN_EXCL)
 925                         return -EBUSY;
 926                 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
 927                         tun = netdev_priv(dev);
 928                 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
 929                         tun = netdev_priv(dev);
 930                 else
 931                         return -EINVAL;
 932
 933                 if (((tun->owner != -1 && cred->euid != tun->owner) ||
 934                      (tun->group != -1 && !in_egroup_p(tun->group))) &&
 935                     !capable(CAP_NET_ADMIN))
 936                         return -EPERM;
 937                 err = security_tun_dev_attach(tun->socket.sk);
 938                 if (err < 0)
 939                         return err;
 940
 941                 err = tun_attach(tun, file);
 942                 if (err < 0)
 943                         return err;
 944         }
 945         else {
 946                 char *name;
 947                 unsigned long flags = 0;
 948
 949                 err = -EINVAL;
 950
 951                 if (!capable(CAP_NET_ADMIN))
 952                         return -EPERM;
 953                 err = security_tun_dev_create();
 954                 if (err < 0)
 955                         return err;
 956
 957                 /* Set dev type */
 958                 if (ifr->ifr_flags & IFF_TUN) {
 959                         /* TUN device */
 960                         flags |= TUN_TUN_DEV;
 961                         name = "tun%d";
 962                 } else if (ifr->ifr_flags & IFF_TAP) {
 963                         /* TAP device */
 964                         flags |= TUN_TAP_DEV;
 965                         name = "tap%d";
 966                 } else
 967                         goto failed;
 968
 969                 if (*ifr->ifr_name)
 970                         name = ifr->ifr_name;
 971
 972                 dev = alloc_netdev(sizeof(struct tun_struct), name,
 973                                    tun_setup);
 974                 if (!dev)
 975                         return -ENOMEM;
 976
 977                 dev_net_set(dev, net);
 978                 dev->rtnl_link_ops = &tun_link_ops;
 979
 980                 tun = netdev_priv(dev);
 981                 tun->dev = dev;
 982                 tun->flags = flags;
 983                 tun->txflt.count = 0;
 984
 985                 err = -ENOMEM;
 986                 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
 987                 if (!sk)
 988                         goto err_free_dev;
 989
 990                 init_waitqueue_head(&tun->socket.wait);
 991                 sock_init_data(&tun->socket, sk);
 992                 sk->sk_write_space = tun_sock_write_space;
 993                 sk->sk_sndbuf = INT_MAX;
 994
 995                 container_of(sk, struct tun_sock, sk)->tun = tun;
 996
 997                 security_tun_dev_post_create(sk);
 998
 999                 tun_net_init(dev);
1000
1001                 if (strchr(dev->name, '%')) {
1002                         err = dev_alloc_name(dev, dev->name);
1003                         if (err < 0)
1004                                 goto err_free_sk;
1005                 }
1006
1007                 err = register_netdevice(tun->dev);
1008                 if (err < 0)
1009                         goto err_free_sk;
1010
1011                 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1012                     device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1013                     device_create_file(&tun->dev->dev, &dev_attr_group))
1014                         printk(KERN_ERR "Failed to create tun sysfs files\n");
1015
1016                 sk->sk_destruct = tun_sock_destruct;
1017
1018                 err = tun_attach(tun, file);
1019                 if (err < 0)
1020                         goto failed;
1021         }
1022
1023         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
1024
1025         if (ifr->ifr_flags & IFF_NO_PI)
1026                 tun->flags |= TUN_NO_PI;
1027         else
1028                 tun->flags &= ~TUN_NO_PI;
1029
1030         if (ifr->ifr_flags & IFF_ONE_QUEUE)
1031                 tun->flags |= TUN_ONE_QUEUE;
1032         else
1033                 tun->flags &= ~TUN_ONE_QUEUE;
1034
1035         if (ifr->ifr_flags & IFF_VNET_HDR)
1036                 tun->flags |= TUN_VNET_HDR;
1037         else
1038                 tun->flags &= ~TUN_VNET_HDR;
1039
1040         /* Make sure persistent devices do not get stuck in
1041          * xoff state.
1042          */
1043         if (netif_running(tun->dev))
1044                 netif_wake_queue(tun->dev);
1045
1046         strcpy(ifr->ifr_name, tun->dev->name);
1047         return 0;
1048
1049  err_free_sk:
1050         sock_put(sk);
1051  err_free_dev:
1052         free_netdev(dev);
1053  failed:
1054         return err;
1055 }
1056
1057 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1058                        struct ifreq *ifr)
1059 {
1060         DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);
1061
1062         strcpy(ifr->ifr_name, tun->dev->name);
1063
1064         ifr->ifr_flags = tun_flags(tun);
1065
1066         return 0;
1067 }
1068
1069 /* This is like a cut-down ethtool ops, except done via tun fd so no
1070  * privs required. */
1071 static int set_offload(struct net_device *dev, unsigned long arg)
1072 {
1073         unsigned int old_features, features;
1074
1075         old_features = dev->features;
1076         /* Unset features, set them as we chew on the arg. */
1077         features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
1078                                     |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6
1079                                     |NETIF_F_UFO));
1080
1081         if (arg & TUN_F_CSUM) {
1082                 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1083                 arg &= ~TUN_F_CSUM;
1084
1085                 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1086                         if (arg & TUN_F_TSO_ECN) {
1087                                 features |= NETIF_F_TSO_ECN;
1088                                 arg &= ~TUN_F_TSO_ECN;
1089                         }
1090                         if (arg & TUN_F_TSO4)
1091                                 features |= NETIF_F_TSO;
1092                         if (arg & TUN_F_TSO6)
1093                                 features |= NETIF_F_TSO6;
1094                         arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1095                 }
1096
1097                 if (arg & TUN_F_UFO) {
1098                         features |= NETIF_F_UFO;
1099                         arg &= ~TUN_F_UFO;
1100                 }
1101         }
1102
1103         /* This gives the user a way to test for new features in future by
1104          * trying to set them. */
1105         if (arg)
1106                 return -EINVAL;
1107
1108         dev->features = features;
1109         if (old_features != dev->features)
1110                 netdev_features_change(dev);
1111
1112         return 0;
1113 }
1114
1115 static long tun_chr_ioctl(struct file *file, unsigned int cmd,
1116                           unsigned long arg)
1117 {
1118         struct tun_file *tfile = file->private_data;
1119         struct tun_struct *tun;
1120         void __user* argp = (void __user*)arg;
1121         struct ifreq ifr;
1122         int sndbuf;
1123         int ret;
1124
1125         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1126                 if (copy_from_user(&ifr, argp, sizeof ifr))
1127                         return -EFAULT;
1128
1129         if (cmd == TUNGETFEATURES) {
1130                 /* Currently this just means: "what IFF flags are valid?".
1131                  * This is needed because we never checked for invalid flags on
1132                  * TUNSETIFF. */
1133                 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1134                                 IFF_VNET_HDR,
1135                                 (unsigned int __user*)argp);
1136         }
1137
1138         rtnl_lock();
1139
1140         tun = __tun_get(tfile);
1141         if (cmd == TUNSETIFF && !tun) {
1142                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1143
1144                 ret = tun_set_iff(tfile->net, file, &ifr);
1145
1146                 if (ret)
1147                         goto unlock;
1148
1149                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
1150                         ret = -EFAULT;
1151                 goto unlock;
1152         }
1153
1154         ret = -EBADFD;
1155         if (!tun)
1156                 goto unlock;
1157
1158         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
1159
1160         ret = 0;
1161         switch (cmd) {
1162         case TUNGETIFF:
1163                 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1164                 if (ret)
1165                         break;
1166
1167                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
1168                         ret = -EFAULT;
1169                 break;
1170
1171         case TUNSETNOCSUM:
1172                 /* Disable/Enable checksum */
1173                 if (arg)
1174                         tun->flags |= TUN_NOCHECKSUM;
1175                 else
1176                         tun->flags &= ~TUN_NOCHECKSUM;
1177
1178                 DBG(KERN_INFO "%s: checksum %s\n",
1179                     tun->dev->name, arg ? "disabled" : "enabled");
1180                 break;
1181
1182         case TUNSETPERSIST:
1183                 /* Disable/Enable persist mode */
1184                 if (arg)
1185                         tun->flags |= TUN_PERSIST;
1186                 else
1187                         tun->flags &= ~TUN_PERSIST;
1188
1189                 DBG(KERN_INFO "%s: persist %s\n",
1190                     tun->dev->name, arg ? "enabled" : "disabled");
1191                 break;
1192
1193         case TUNSETOWNER:
1194                 /* Set owner of the device */
1195                 tun->owner = (uid_t) arg;
1196
1197                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
1198                 break;
1199
1200         case TUNSETGROUP:
1201                 /* Set group of the device */
1202                 tun->group= (gid_t) arg;
1203
1204                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
1205                 break;
1206
1207         case TUNSETLINK:
1208                 /* Only allow setting the type when the interface is down */
1209                 if (tun->dev->flags & IFF_UP) {
1210                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
1211                                 tun->dev->name);
1212                         ret = -EBUSY;
1213                 } else {
1214                         tun->dev->type = (int) arg;
1215                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
1216                         ret = 0;
1217                 }
1218                 break;
1219
1220 #ifdef TUN_DEBUG
1221         case TUNSETDEBUG:
1222                 tun->debug = arg;
1223                 break;
1224 #endif
1225         case TUNSETOFFLOAD:
1226                 ret = set_offload(tun->dev, arg);
1227                 break;
1228
1229         case TUNSETTXFILTER:
1230                 /* Can be set only for TAPs */
1231                 ret = -EINVAL;
1232                 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1233                         break;
1234                 ret = update_filter(&tun->txflt, (void __user *)arg);
1235                 break;
1236
1237         case SIOCGIFHWADDR:
1238                 /* Get hw addres */
1239                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1240                 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1241                 if (copy_to_user(argp, &ifr, sizeof ifr))
1242                         ret = -EFAULT;
1243                 break;
1244
1245         case SIOCSIFHWADDR:
1246                 /* Set hw address */
1247                 DBG(KERN_DEBUG "%s: set hw address: %pM\n",
1248                         tun->dev->name, ifr.ifr_hwaddr.sa_data);
1249
1250                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1251                 break;
1252
1253         case TUNGETSNDBUF:
1254                 sndbuf = tun->socket.sk->sk_sndbuf;
1255                 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1256                         ret = -EFAULT;
1257                 break;
1258
1259         case TUNSETSNDBUF:
1260                 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1261                         ret = -EFAULT;
1262                         break;
1263                 }
1264
1265                 tun->socket.sk->sk_sndbuf = sndbuf;
1266                 break;
1267
1268         default:
1269                 ret = -EINVAL;
1270                 break;
1271         };
1272
1273 unlock:
1274         rtnl_unlock();
1275         if (tun)
1276                 tun_put(tun);
1277         return ret;
1278 }
1279
1280 static int tun_chr_fasync(int fd, struct file *file, int on)
1281 {
1282         struct tun_struct *tun = tun_get(file);
1283         int ret;
1284
1285         if (!tun)
1286                 return -EBADFD;
1287
1288         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
1289
1290         lock_kernel();
1291         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1292                 goto out;
1293
1294         if (on) {
1295                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1296                 if (ret)
1297                         goto out;
1298                 tun->flags |= TUN_FASYNC;
1299         } else
1300                 tun->flags &= ~TUN_FASYNC;
1301         ret = 0;
1302 out:
1303         unlock_kernel();
1304         tun_put(tun);
1305         return ret;
1306 }
1307
1308 static int tun_chr_open(struct inode *inode, struct file * file)
1309 {
1310         struct tun_file *tfile;
1311         cycle_kernel_lock();
1312         DBG1(KERN_INFO "tunX: tun_chr_open\n");
1313
1314         tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1315         if (!tfile)
1316                 return -ENOMEM;
1317         atomic_set(&tfile->count, 0);
1318         tfile->tun = NULL;
1319         tfile->net = get_net(current->nsproxy->net_ns);
1320         file->private_data = tfile;
1321         return 0;
1322 }
1323
1324 static int tun_chr_close(struct inode *inode, struct file *file)
1325 {
1326         struct tun_file *tfile = file->private_data;
1327         struct tun_struct *tun;
1328
1329         tun = __tun_get(tfile);
1330         if (tun) {
1331                 struct net_device *dev = tun->dev;
1332
1333                 DBG(KERN_INFO "%s: tun_chr_close\n", dev->name);
1334
1335                 __tun_detach(tun);
1336
1337                 /* If desireable, unregister the netdevice. */
1338                 if (!(tun->flags & TUN_PERSIST)) {
1339                         rtnl_lock();
1340                         if (dev->reg_state == NETREG_REGISTERED)
1341                                 unregister_netdevice(dev);
1342                         rtnl_unlock();
1343                 }
1344         }
1345
1346         tun = tfile->tun;
1347         if (tun)
1348                 sock_put(tun->socket.sk);
1349
1350         put_net(tfile->net);
1351         kfree(tfile);
1352
1353         return 0;
1354 }
1355
1356 static const struct file_operations tun_fops = {
1357         .owner  = THIS_MODULE,
1358         .llseek = no_llseek,
1359         .read  = do_sync_read,
1360         .aio_read  = tun_chr_aio_read,
1361         .write = do_sync_write,
1362         .aio_write = tun_chr_aio_write,
1363         .poll   = tun_chr_poll,
1364         .unlocked_ioctl = tun_chr_ioctl,
1365         .open   = tun_chr_open,
1366         .release = tun_chr_close,
1367         .fasync = tun_chr_fasync
1368 };
1369
1370 static struct miscdevice tun_miscdev = {
1371         .minor = TUN_MINOR,
1372         .name = "tun",
1373         .nodename = "net/tun",
1374         .fops = &tun_fops,
1375 };
1376
1377 /* ethtool interface */
1378
1379 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1380 {
1381         cmd->supported          = 0;
1382         cmd->advertising        = 0;
1383         cmd->speed              = SPEED_10;
1384         cmd->duplex             = DUPLEX_FULL;
1385         cmd->port               = PORT_TP;
1386         cmd->phy_address        = 0;
1387         cmd->transceiver        = XCVR_INTERNAL;
1388         cmd->autoneg            = AUTONEG_DISABLE;
1389         cmd->maxtxpkt           = 0;
1390         cmd->maxrxpkt           = 0;
1391         return 0;
1392 }
1393
1394 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1395 {
1396         struct tun_struct *tun = netdev_priv(dev);
1397
1398         strcpy(info->driver, DRV_NAME);
1399         strcpy(info->version, DRV_VERSION);
1400         strcpy(info->fw_version, "N/A");
1401
1402         switch (tun->flags & TUN_TYPE_MASK) {
1403         case TUN_TUN_DEV:
1404                 strcpy(info->bus_info, "tun");
1405                 break;
1406         case TUN_TAP_DEV:
1407                 strcpy(info->bus_info, "tap");
1408                 break;
1409         }
1410 }
1411
1412 static u32 tun_get_msglevel(struct net_device *dev)
1413 {
1414 #ifdef TUN_DEBUG
1415         struct tun_struct *tun = netdev_priv(dev);
1416         return tun->debug;
1417 #else
1418         return -EOPNOTSUPP;
1419 #endif
1420 }
1421
1422 static void tun_set_msglevel(struct net_device *dev, u32 value)
1423 {
1424 #ifdef TUN_DEBUG
1425         struct tun_struct *tun = netdev_priv(dev);
1426         tun->debug = value;
1427 #endif
1428 }
1429
1430 static u32 tun_get_link(struct net_device *dev)
1431 {
1432         struct tun_struct *tun = netdev_priv(dev);
1433         return !!tun->tfile;
1434 }
1435
1436 static u32 tun_get_rx_csum(struct net_device *dev)
1437 {
1438         struct tun_struct *tun = netdev_priv(dev);
1439         return (tun->flags & TUN_NOCHECKSUM) == 0;
1440 }
1441
1442 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1443 {
1444         struct tun_struct *tun = netdev_priv(dev);
1445         if (data)
1446                 tun->flags &= ~TUN_NOCHECKSUM;
1447         else
1448                 tun->flags |= TUN_NOCHECKSUM;
1449         return 0;
1450 }
1451
1452 static const struct ethtool_ops tun_ethtool_ops = {
1453         .get_settings   = tun_get_settings,
1454         .get_drvinfo    = tun_get_drvinfo,
1455         .get_msglevel   = tun_get_msglevel,
1456         .set_msglevel   = tun_set_msglevel,
1457         .get_link       = tun_get_link,
1458         .get_rx_csum    = tun_get_rx_csum,
1459         .set_rx_csum    = tun_set_rx_csum
1460 };
1461
1462
1463 static int __init tun_init(void)
1464 {
1465         int ret = 0;
1466
1467         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1468         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1469
1470         ret = rtnl_link_register(&tun_link_ops);
1471         if (ret) {
1472                 printk(KERN_ERR "tun: Can't register link_ops\n");
1473                 goto err_linkops;
1474         }
1475
1476         ret = misc_register(&tun_miscdev);
1477         if (ret) {
1478                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1479                 goto err_misc;
1480         }
1481         return  0;
1482 err_misc:
1483         rtnl_link_unregister(&tun_link_ops);
1484 err_linkops:
1485         return ret;
1486 }
1487
1488 static void tun_cleanup(void)
1489 {
1490         misc_deregister(&tun_miscdev);
1491         rtnl_link_unregister(&tun_link_ops);
1492 }
1493
1494 module_init(tun_init);
1495 module_exit(tun_cleanup);
1496 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1497 MODULE_AUTHOR(DRV_COPYRIGHT);
1498 MODULE_LICENSE("GPL");
1499 MODULE_ALIAS_MISCDEV(TUN_MINOR);