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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/poll.h>
  48 #include <linux/fcntl.h>
  49 #include <linux/init.h>
  50 #include <linux/skbuff.h>
  51 #include <linux/netdevice.h>
  52 #include <linux/etherdevice.h>
  53 #include <linux/miscdevice.h>
  54 #include <linux/ethtool.h>
  55 #include <linux/rtnetlink.h>
  56 #include <linux/if.h>
  57 #include <linux/if_arp.h>
  58 #include <linux/if_ether.h>
  59 #include <linux/if_tun.h>
  60 #include <linux/crc32.h>
  61 #include <linux/nsproxy.h>
  62 #include <linux/virtio_net.h>
  63 #include <net/net_namespace.h>
  64 #include <net/netns/generic.h>
  65 #include <net/rtnetlink.h>
  66 #include <net/sock.h>
  67
  68 #include <asm/system.h>
  69 #include <asm/uaccess.h>
  70
  71 /* Uncomment to enable debugging */
  72 /* #define TUN_DEBUG 1 */
  73
  74 #ifdef TUN_DEBUG
  75 static int debug;
  76
  77 #define DBG  if(tun->debug)printk
  78 #define DBG1 if(debug==2)printk
  79 #else
  80 #define DBG( a... )
  81 #define DBG1( a... )
  82 #endif
  83
  84 #define FLT_EXACT_COUNT 8
  85 struct tap_filter {
  86         unsigned int    count;    /* Number of addrs. Zero means disabled */
  87         u32             mask[2];  /* Mask of the hashed addrs */
  88         unsigned char   addr[FLT_EXACT_COUNT][ETH_ALEN];
  89 };
  90
  91 struct tun_file {
  92         atomic_t count;
  93         struct tun_struct *tun;
  94         struct net *net;
  95 };
  96
  97 struct tun_sock;
  98
  99 struct tun_struct {
 100         struct tun_file         *tfile;
 101         unsigned int            flags;
 102         uid_t                   owner;
 103         gid_t                   group;
 104
 105         struct net_device       *dev;
 106         struct fasync_struct    *fasync;
 107
 108         struct tap_filter       txflt;
 109         struct socket           socket;
 110
 111 #ifdef TUN_DEBUG
 112         int debug;
 113 #endif
 114 };
 115
 116 struct tun_sock {
 117         struct sock             sk;
 118         struct tun_struct       *tun;
 119 };
 120
 121 static inline struct tun_sock *tun_sk(struct sock *sk)
 122 {
 123         return container_of(sk, struct tun_sock, sk);
 124 }
 125
 126 static int tun_attach(struct tun_struct *tun, struct file *file)
 127 {
 128         struct tun_file *tfile = file->private_data;
 129         int err;
 130
 131         ASSERT_RTNL();
 132
 133         netif_tx_lock_bh(tun->dev);
 134
 135         err = -EINVAL;
 136         if (tfile->tun)
 137                 goto out;
 138
 139         err = -EBUSY;
 140         if (tun->tfile)
 141                 goto out;
 142
 143         err = 0;
 144         tfile->tun = tun;
 145         tun->tfile = tfile;
 146         dev_hold(tun->dev);
 147         sock_hold(tun->socket.sk);
 148         atomic_inc(&tfile->count);
 149
 150 out:
 151         netif_tx_unlock_bh(tun->dev);
 152         return err;
 153 }
 154
 155 static void __tun_detach(struct tun_struct *tun)
 156 {
 157         /* Detach from net device */
 158         netif_tx_lock_bh(tun->dev);
 159         tun->tfile = NULL;
 160         netif_tx_unlock_bh(tun->dev);
 161
 162         /* Drop read queue */
 163         skb_queue_purge(&tun->socket.sk->sk_receive_queue);
 164
 165         /* Drop the extra count on the net device */
 166         dev_put(tun->dev);
 167 }
 168
 169 static void tun_detach(struct tun_struct *tun)
 170 {
 171         rtnl_lock();
 172         __tun_detach(tun);
 173         rtnl_unlock();
 174 }
 175
 176 static struct tun_struct *__tun_get(struct tun_file *tfile)
 177 {
 178         struct tun_struct *tun = NULL;
 179
 180         if (atomic_inc_not_zero(&tfile->count))
 181                 tun = tfile->tun;
 182
 183         return tun;
 184 }
 185
 186 static struct tun_struct *tun_get(struct file *file)
 187 {
 188         return __tun_get(file->private_data);
 189 }
 190
 191 static void tun_put(struct tun_struct *tun)
 192 {
 193         struct tun_file *tfile = tun->tfile;
 194
 195         if (atomic_dec_and_test(&tfile->count))
 196                 tun_detach(tfile->tun);
 197 }
 198
 199 /* TAP filterting */
 200 static void addr_hash_set(u32 *mask, const u8 *addr)
 201 {
 202         int n = ether_crc(ETH_ALEN, addr) >> 26;
 203         mask[n >> 5] |= (1 << (n & 31));
 204 }
 205
 206 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
 207 {
 208         int n = ether_crc(ETH_ALEN, addr) >> 26;
 209         return mask[n >> 5] & (1 << (n & 31));
 210 }
 211
 212 static int update_filter(struct tap_filter *filter, void __user *arg)
 213 {
 214         struct { u8 u[ETH_ALEN]; } *addr;
 215         struct tun_filter uf;
 216         int err, alen, n, nexact;
 217
 218         if (copy_from_user(&uf, arg, sizeof(uf)))
 219                 return -EFAULT;
 220
 221         if (!uf.count) {
 222                 /* Disabled */
 223                 filter->count = 0;
 224                 return 0;
 225         }
 226
 227         alen = ETH_ALEN * uf.count;
 228         addr = kmalloc(alen, GFP_KERNEL);
 229         if (!addr)
 230                 return -ENOMEM;
 231
 232         if (copy_from_user(addr, arg + sizeof(uf), alen)) {
 233                 err = -EFAULT;
 234                 goto done;
 235         }
 236
 237         /* The filter is updated without holding any locks. Which is
 238          * perfectly safe. We disable it first and in the worst
 239          * case we'll accept a few undesired packets. */
 240         filter->count = 0;
 241         wmb();
 242
 243         /* Use first set of addresses as an exact filter */
 244         for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
 245                 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
 246
 247         nexact = n;
 248
 249         /* Remaining multicast addresses are hashed,
 250          * unicast will leave the filter disabled. */
 251         memset(filter->mask, 0, sizeof(filter->mask));
 252         for (; n < uf.count; n++) {
 253                 if (!is_multicast_ether_addr(addr[n].u)) {
 254                         err = 0; /* no filter */
 255                         goto done;
 256                 }
 257                 addr_hash_set(filter->mask, addr[n].u);
 258         }
 259
 260         /* For ALLMULTI just set the mask to all ones.
 261          * This overrides the mask populated above. */
 262         if ((uf.flags & TUN_FLT_ALLMULTI))
 263                 memset(filter->mask, ~0, sizeof(filter->mask));
 264
 265         /* Now enable the filter */
 266         wmb();
 267         filter->count = nexact;
 268
 269         /* Return the number of exact filters */
 270         err = nexact;
 271
 272 done:
 273         kfree(addr);
 274         return err;
 275 }
 276
 277 /* Returns: 0 - drop, !=0 - accept */
 278 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
 279 {
 280         /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
 281          * at this point. */
 282         struct ethhdr *eh = (struct ethhdr *) skb->data;
 283         int i;
 284
 285         /* Exact match */
 286         for (i = 0; i < filter->count; i++)
 287                 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
 288                         return 1;
 289
 290         /* Inexact match (multicast only) */
 291         if (is_multicast_ether_addr(eh->h_dest))
 292                 return addr_hash_test(filter->mask, eh->h_dest);
 293
 294         return 0;
 295 }
 296
 297 /*
 298  * Checks whether the packet is accepted or not.
 299  * Returns: 0 - drop, !=0 - accept
 300  */
 301 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
 302 {
 303         if (!filter->count)
 304                 return 1;
 305
 306         return run_filter(filter, skb);
 307 }
 308
 309 /* Network device part of the driver */
 310
 311 static const struct ethtool_ops tun_ethtool_ops;
 312
 313 /* Net device detach from fd. */
 314 static void tun_net_uninit(struct net_device *dev)
 315 {
 316         struct tun_struct *tun = netdev_priv(dev);
 317         struct tun_file *tfile = tun->tfile;
 318
 319         /* Inform the methods they need to stop using the dev.
 320          */
 321         if (tfile) {
 322                 wake_up_all(&tun->socket.wait);
 323                 if (atomic_dec_and_test(&tfile->count))
 324                         __tun_detach(tun);
 325         }
 326 }
 327
 328 static void tun_free_netdev(struct net_device *dev)
 329 {
 330         struct tun_struct *tun = netdev_priv(dev);
 331
 332         sock_put(tun->socket.sk);
 333 }
 334
 335 /* Net device open. */
 336 static int tun_net_open(struct net_device *dev)
 337 {
 338         netif_start_queue(dev);
 339         return 0;
 340 }
 341
 342 /* Net device close. */
 343 static int tun_net_close(struct net_device *dev)
 344 {
 345         netif_stop_queue(dev);
 346         return 0;
 347 }
 348
 349 /* Net device start xmit */
 350 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 351 {
 352         struct tun_struct *tun = netdev_priv(dev);
 353
 354         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
 355
 356         /* Drop packet if interface is not attached */
 357         if (!tun->tfile)
 358                 goto drop;
 359
 360         /* Drop if the filter does not like it.
 361          * This is a noop if the filter is disabled.
 362          * Filter can be enabled only for the TAP devices. */
 363         if (!check_filter(&tun->txflt, skb))
 364                 goto drop;
 365
 366         if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
 367                 if (!(tun->flags & TUN_ONE_QUEUE)) {
 368                         /* Normal queueing mode. */
 369                         /* Packet scheduler handles dropping of further packets. */
 370                         netif_stop_queue(dev);
 371
 372                         /* We won't see all dropped packets individually, so overrun
 373                          * error is more appropriate. */
 374                         dev->stats.tx_fifo_errors++;
 375                 } else {
 376                         /* Single queue mode.
 377                          * Driver handles dropping of all packets itself. */
 378                         goto drop;
 379                 }
 380         }
 381
 382         /* Enqueue packet */
 383         skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
 384         dev->trans_start = jiffies;
 385
 386         /* Notify and wake up reader process */
 387         if (tun->flags & TUN_FASYNC)
 388                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
 389         wake_up_interruptible(&tun->socket.wait);
 390         return NETDEV_TX_OK;
 391
 392 drop:
 393         dev->stats.tx_dropped++;
 394         kfree_skb(skb);
 395         return NETDEV_TX_OK;
 396 }
 397
 398 static void tun_net_mclist(struct net_device *dev)
 399 {
 400         /*
 401          * This callback is supposed to deal with mc filter in
 402          * _rx_ path and has nothing to do with the _tx_ path.
 403          * In rx path we always accept everything userspace gives us.
 404          */
 405         return;
 406 }
 407
 408 #define MIN_MTU 68
 409 #define MAX_MTU 65535
 410
 411 static int
 412 tun_net_change_mtu(struct net_device *dev, int new_mtu)
 413 {
 414         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
 415                 return -EINVAL;
 416         dev->mtu = new_mtu;
 417         return 0;
 418 }
 419
 420 static const struct net_device_ops tun_netdev_ops = {
 421         .ndo_uninit             = tun_net_uninit,
 422         .ndo_open               = tun_net_open,
 423         .ndo_stop               = tun_net_close,
 424         .ndo_start_xmit         = tun_net_xmit,
 425         .ndo_change_mtu         = tun_net_change_mtu,
 426 };
 427
 428 static const struct net_device_ops tap_netdev_ops = {
 429         .ndo_uninit             = tun_net_uninit,
 430         .ndo_open               = tun_net_open,
 431         .ndo_stop               = tun_net_close,
 432         .ndo_start_xmit         = tun_net_xmit,
 433         .ndo_change_mtu         = tun_net_change_mtu,
 434         .ndo_set_multicast_list = tun_net_mclist,
 435         .ndo_set_mac_address    = eth_mac_addr,
 436         .ndo_validate_addr      = eth_validate_addr,
 437 };
 438
 439 /* Initialize net device. */
 440 static void tun_net_init(struct net_device *dev)
 441 {
 442         struct tun_struct *tun = netdev_priv(dev);
 443
 444         switch (tun->flags & TUN_TYPE_MASK) {
 445         case TUN_TUN_DEV:
 446                 dev->netdev_ops = &tun_netdev_ops;
 447
 448                 /* Point-to-Point TUN Device */
 449                 dev->hard_header_len = 0;
 450                 dev->addr_len = 0;
 451                 dev->mtu = 1500;
 452
 453                 /* Zero header length */
 454                 dev->type = ARPHRD_NONE;
 455                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 456                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 457                 break;
 458
 459         case TUN_TAP_DEV:
 460                 dev->netdev_ops = &tap_netdev_ops;
 461                 /* Ethernet TAP Device */
 462                 ether_setup(dev);
 463
 464                 random_ether_addr(dev->dev_addr);
 465
 466                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 467                 break;
 468         }
 469 }
 470
 471 /* Character device part */
 472
 473 /* Poll */
 474 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
 475 {
 476         struct tun_file *tfile = file->private_data;
 477         struct tun_struct *tun = __tun_get(tfile);
 478         struct sock *sk;
 479         unsigned int mask = 0;
 480
 481         if (!tun)
 482                 return POLLERR;
 483
 484         sk = tun->socket.sk;
 485
 486         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
 487
 488         poll_wait(file, &tun->socket.wait, wait);
 489
 490         if (!skb_queue_empty(&sk->sk_receive_queue))
 491                 mask |= POLLIN | POLLRDNORM;
 492
 493         if (sock_writeable(sk) ||
 494             (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
 495              sock_writeable(sk)))
 496                 mask |= POLLOUT | POLLWRNORM;
 497
 498         if (tun->dev->reg_state != NETREG_REGISTERED)
 499                 mask = POLLERR;
 500
 501         tun_put(tun);
 502         return mask;
 503 }
 504
 505 /* prepad is the amount to reserve at front.  len is length after that.
 506  * linear is a hint as to how much to copy (usually headers). */
 507 static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
 508                                             size_t prepad, size_t len,
 509                                             size_t linear, int noblock)
 510 {
 511         struct sock *sk = tun->socket.sk;
 512         struct sk_buff *skb;
 513         int err;
 514
 515         /* Under a page?  Don't bother with paged skb. */
 516         if (prepad + len < PAGE_SIZE || !linear)
 517                 linear = len;
 518
 519         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
 520                                    &err);
 521         if (!skb)
 522                 return ERR_PTR(err);
 523
 524         skb_reserve(skb, prepad);
 525         skb_put(skb, linear);
 526         skb->data_len = len - linear;
 527         skb->len += len - linear;
 528
 529         return skb;
 530 }
 531
 532 /* Get packet from user space buffer */
 533 static __inline__ ssize_t tun_get_user(struct tun_struct *tun,
 534                                        const struct iovec *iv, size_t count,
 535                                        int noblock)
 536 {
 537         struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
 538         struct sk_buff *skb;
 539         size_t len = count, align = 0;
 540         struct virtio_net_hdr gso = { 0 };
 541         int offset = 0;
 542
 543         if (!(tun->flags & TUN_NO_PI)) {
 544                 if ((len -= sizeof(pi)) > count)
 545                         return -EINVAL;
 546
 547                 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
 548                         return -EFAULT;
 549                 offset += sizeof(pi);
 550         }
 551
 552         if (tun->flags & TUN_VNET_HDR) {
 553                 if ((len -= sizeof(gso)) > count)
 554                         return -EINVAL;
 555
 556                 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
 557                         return -EFAULT;
 558
 559                 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
 560                     gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
 561                         gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
 562
 563                 if (gso.hdr_len > len)
 564                         return -EINVAL;
 565                 offset += sizeof(gso);
 566         }
 567
 568         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
 569                 align = NET_IP_ALIGN;
 570                 if (unlikely(len < ETH_HLEN ||
 571                              (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
 572                         return -EINVAL;
 573         }
 574
 575         skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
 576         if (IS_ERR(skb)) {
 577                 if (PTR_ERR(skb) != -EAGAIN)
 578                         tun->dev->stats.rx_dropped++;
 579                 return PTR_ERR(skb);
 580         }
 581
 582         if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
 583                 tun->dev->stats.rx_dropped++;
 584                 kfree_skb(skb);
 585                 return -EFAULT;
 586         }
 587
 588         if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 589                 if (!skb_partial_csum_set(skb, gso.csum_start,
 590                                           gso.csum_offset)) {
 591                         tun->dev->stats.rx_frame_errors++;
 592                         kfree_skb(skb);
 593                         return -EINVAL;
 594                 }
 595         } else if (tun->flags & TUN_NOCHECKSUM)
 596                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 597
 598         switch (tun->flags & TUN_TYPE_MASK) {
 599         case TUN_TUN_DEV:
 600                 if (tun->flags & TUN_NO_PI) {
 601                         switch (skb->data[0] & 0xf0) {
 602                         case 0x40:
 603                                 pi.proto = htons(ETH_P_IP);
 604                                 break;
 605                         case 0x60:
 606                                 pi.proto = htons(ETH_P_IPV6);
 607                                 break;
 608                         default:
 609                                 tun->dev->stats.rx_dropped++;
 610                                 kfree_skb(skb);
 611                                 return -EINVAL;
 612                         }
 613                 }
 614
 615                 skb_reset_mac_header(skb);
 616                 skb->protocol = pi.proto;
 617                 skb->dev = tun->dev;
 618                 break;
 619         case TUN_TAP_DEV:
 620                 skb->protocol = eth_type_trans(skb, tun->dev);
 621                 break;
 622         };
 623
 624         if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 625                 pr_debug("GSO!\n");
 626                 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 627                 case VIRTIO_NET_HDR_GSO_TCPV4:
 628                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
 629                         break;
 630                 case VIRTIO_NET_HDR_GSO_TCPV6:
 631                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 632                         break;
 633                 case VIRTIO_NET_HDR_GSO_UDP:
 634                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 635                         break;
 636                 default:
 637                         tun->dev->stats.rx_frame_errors++;
 638                         kfree_skb(skb);
 639                         return -EINVAL;
 640                 }
 641
 642                 if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
 643                         skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
 644
 645                 skb_shinfo(skb)->gso_size = gso.gso_size;
 646                 if (skb_shinfo(skb)->gso_size == 0) {
 647                         tun->dev->stats.rx_frame_errors++;
 648                         kfree_skb(skb);
 649                         return -EINVAL;
 650                 }
 651
 652                 /* Header must be checked, and gso_segs computed. */
 653                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
 654                 skb_shinfo(skb)->gso_segs = 0;
 655         }
 656
 657         netif_rx_ni(skb);
 658
 659         tun->dev->stats.rx_packets++;
 660         tun->dev->stats.rx_bytes += len;
 661
 662         return count;
 663 }
 664
 665 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
 666                               unsigned long count, loff_t pos)
 667 {
 668         struct file *file = iocb->ki_filp;
 669         struct tun_struct *tun = tun_get(file);
 670         ssize_t result;
 671
 672         if (!tun)
 673                 return -EBADFD;
 674
 675         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
 676
 677         result = tun_get_user(tun, iv, iov_length(iv, count),
 678                               file->f_flags & O_NONBLOCK);
 679
 680         tun_put(tun);
 681         return result;
 682 }
 683
 684 /* Put packet to the user space buffer */
 685 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
 686                                        struct sk_buff *skb,
 687                                        const struct iovec *iv, int len)
 688 {
 689         struct tun_pi pi = { 0, skb->protocol };
 690         ssize_t total = 0;
 691
 692         if (!(tun->flags & TUN_NO_PI)) {
 693                 if ((len -= sizeof(pi)) < 0)
 694                         return -EINVAL;
 695
 696                 if (len < skb->len) {
 697                         /* Packet will be striped */
 698                         pi.flags |= TUN_PKT_STRIP;
 699                 }
 700
 701                 if (memcpy_toiovecend(iv, (void *) &pi, 0, sizeof(pi)))
 702                         return -EFAULT;
 703                 total += sizeof(pi);
 704         }
 705
 706         if (tun->flags & TUN_VNET_HDR) {
 707                 struct virtio_net_hdr gso = { 0 }; /* no info leak */
 708                 if ((len -= sizeof(gso)) < 0)
 709                         return -EINVAL;
 710
 711                 if (skb_is_gso(skb)) {
 712                         struct skb_shared_info *sinfo = skb_shinfo(skb);
 713
 714                         /* This is a hint as to how much should be linear. */
 715                         gso.hdr_len = skb_headlen(skb);
 716                         gso.gso_size = sinfo->gso_size;
 717                         if (sinfo->gso_type & SKB_GSO_TCPV4)
 718                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 719                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
 720                                 gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 721                         else if (sinfo->gso_type & SKB_GSO_UDP)
 722                                 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
 723                         else
 724                                 BUG();
 725                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
 726                                 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 727                 } else
 728                         gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
 729
 730                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
 731                         gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 732                         gso.csum_start = skb->csum_start - skb_headroom(skb);
 733                         gso.csum_offset = skb->csum_offset;
 734                 } /* else everything is zero */
 735
 736                 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
 737                                                sizeof(gso))))
 738                         return -EFAULT;
 739                 total += sizeof(gso);
 740         }
 741
 742         len = min_t(int, skb->len, len);
 743
 744         skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
 745         total += len;
 746
 747         tun->dev->stats.tx_packets++;
 748         tun->dev->stats.tx_bytes += len;
 749
 750         return total;
 751 }
 752
 753 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
 754                             unsigned long count, loff_t pos)
 755 {
 756         struct file *file = iocb->ki_filp;
 757         struct tun_file *tfile = file->private_data;
 758         struct tun_struct *tun = __tun_get(tfile);
 759         DECLARE_WAITQUEUE(wait, current);
 760         struct sk_buff *skb;
 761         ssize_t len, ret = 0;
 762
 763         if (!tun)
 764                 return -EBADFD;
 765
 766         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
 767
 768         len = iov_length(iv, count);
 769         if (len < 0) {
 770                 ret = -EINVAL;
 771                 goto out;
 772         }
 773
 774         add_wait_queue(&tun->socket.wait, &wait);
 775         while (len) {
 776                 current->state = TASK_INTERRUPTIBLE;
 777
 778                 /* Read frames from the queue */
 779                 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
 780                         if (file->f_flags & O_NONBLOCK) {
 781                                 ret = -EAGAIN;
 782                                 break;
 783                         }
 784                         if (signal_pending(current)) {
 785                                 ret = -ERESTARTSYS;
 786                                 break;
 787                         }
 788                         if (tun->dev->reg_state != NETREG_REGISTERED) {
 789                                 ret = -EIO;
 790                                 break;
 791                         }
 792
 793                         /* Nothing to read, let's sleep */
 794                         schedule();
 795                         continue;
 796                 }
 797                 netif_wake_queue(tun->dev);
 798
 799                 ret = tun_put_user(tun, skb, iv, len);
 800                 kfree_skb(skb);
 801                 break;
 802         }
 803
 804         current->state = TASK_RUNNING;
 805         remove_wait_queue(&tun->socket.wait, &wait);
 806
 807 out:
 808         tun_put(tun);
 809         return ret;
 810 }
 811
 812 static void tun_setup(struct net_device *dev)
 813 {
 814         struct tun_struct *tun = netdev_priv(dev);
 815
 816         tun->owner = -1;
 817         tun->group = -1;
 818
 819         dev->ethtool_ops = &tun_ethtool_ops;
 820         dev->destructor = tun_free_netdev;
 821 }
 822
 823 /* Trivial set of netlink ops to allow deleting tun or tap
 824  * device with netlink.
 825  */
 826 static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
 827 {
 828         return -EINVAL;
 829 }
 830
 831 static struct rtnl_link_ops tun_link_ops __read_mostly = {
 832         .kind           = DRV_NAME,
 833         .priv_size      = sizeof(struct tun_struct),
 834         .setup          = tun_setup,
 835         .validate       = tun_validate,
 836 };
 837
 838 static void tun_sock_write_space(struct sock *sk)
 839 {
 840         struct tun_struct *tun;
 841
 842         if (!sock_writeable(sk))
 843                 return;
 844
 845         if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
 846                 return;
 847
 848         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
 849                 wake_up_interruptible_sync(sk->sk_sleep);
 850
 851         tun = container_of(sk, struct tun_sock, sk)->tun;
 852         kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
 853 }
 854
 855 static void tun_sock_destruct(struct sock *sk)
 856 {
 857         free_netdev(container_of(sk, struct tun_sock, sk)->tun->dev);
 858 }
 859
 860 static struct proto tun_proto = {
 861         .name           = "tun",
 862         .owner          = THIS_MODULE,
 863         .obj_size       = sizeof(struct tun_sock),
 864 };
 865
 866 static int tun_flags(struct tun_struct *tun)
 867 {
 868         int flags = 0;
 869
 870         if (tun->flags & TUN_TUN_DEV)
 871                 flags |= IFF_TUN;
 872         else
 873                 flags |= IFF_TAP;
 874
 875         if (tun->flags & TUN_NO_PI)
 876                 flags |= IFF_NO_PI;
 877
 878         if (tun->flags & TUN_ONE_QUEUE)
 879                 flags |= IFF_ONE_QUEUE;
 880
 881         if (tun->flags & TUN_VNET_HDR)
 882                 flags |= IFF_VNET_HDR;
 883
 884         return flags;
 885 }
 886
 887 static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
 888                               char *buf)
 889 {
 890         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
 891         return sprintf(buf, "0x%x\n", tun_flags(tun));
 892 }
 893
 894 static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
 895                               char *buf)
 896 {
 897         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
 898         return sprintf(buf, "%d\n", tun->owner);
 899 }
 900
 901 static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
 902                               char *buf)
 903 {
 904         struct tun_struct *tun = netdev_priv(to_net_dev(dev));
 905         return sprintf(buf, "%d\n", tun->group);
 906 }
 907
 908 static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
 909 static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
 910 static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
 911
 912 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 913 {
 914         struct sock *sk;
 915         struct tun_struct *tun;
 916         struct net_device *dev;
 917         int err;
 918
 919         dev = __dev_get_by_name(net, ifr->ifr_name);
 920         if (dev) {
 921                 const struct cred *cred = current_cred();
 922
 923                 if (ifr->ifr_flags & IFF_TUN_EXCL)
 924                         return -EBUSY;
 925                 if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
 926                         tun = netdev_priv(dev);
 927                 else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
 928                         tun = netdev_priv(dev);
 929                 else
 930                         return -EINVAL;
 931
 932                 if (((tun->owner != -1 && cred->euid != tun->owner) ||
 933                      (tun->group != -1 && !in_egroup_p(tun->group))) &&
 934                     !capable(CAP_NET_ADMIN))
 935                         return -EPERM;
 936                 err = security_tun_dev_attach(tun->socket.sk);
 937                 if (err < 0)
 938                         return err;
 939
 940                 err = tun_attach(tun, file);
 941                 if (err < 0)
 942                         return err;
 943         }
 944         else {
 945                 char *name;
 946                 unsigned long flags = 0;
 947
 948                 if (!capable(CAP_NET_ADMIN))
 949                         return -EPERM;
 950                 err = security_tun_dev_create();
 951                 if (err < 0)
 952                         return err;
 953
 954                 /* Set dev type */
 955                 if (ifr->ifr_flags & IFF_TUN) {
 956                         /* TUN device */
 957                         flags |= TUN_TUN_DEV;
 958                         name = "tun%d";
 959                 } else if (ifr->ifr_flags & IFF_TAP) {
 960                         /* TAP device */
 961                         flags |= TUN_TAP_DEV;
 962                         name = "tap%d";
 963                 } else
 964                         return -EINVAL;
 965
 966                 if (*ifr->ifr_name)
 967                         name = ifr->ifr_name;
 968
 969                 dev = alloc_netdev(sizeof(struct tun_struct), name,
 970                                    tun_setup);
 971                 if (!dev)
 972                         return -ENOMEM;
 973
 974                 dev_net_set(dev, net);
 975                 dev->rtnl_link_ops = &tun_link_ops;
 976
 977                 tun = netdev_priv(dev);
 978                 tun->dev = dev;
 979                 tun->flags = flags;
 980                 tun->txflt.count = 0;
 981
 982                 err = -ENOMEM;
 983                 sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
 984                 if (!sk)
 985                         goto err_free_dev;
 986
 987                 init_waitqueue_head(&tun->socket.wait);
 988                 sock_init_data(&tun->socket, sk);
 989                 sk->sk_write_space = tun_sock_write_space;
 990                 sk->sk_sndbuf = INT_MAX;
 991
 992                 container_of(sk, struct tun_sock, sk)->tun = tun;
 993
 994                 security_tun_dev_post_create(sk);
 995
 996                 tun_net_init(dev);
 997
 998                 if (strchr(dev->name, '%')) {
 999                         err = dev_alloc_name(dev, dev->name);
1000                         if (err < 0)
1001                                 goto err_free_sk;
1002                 }
1003
1004                 err = register_netdevice(tun->dev);
1005                 if (err < 0)
1006                         goto err_free_sk;
1007
1008                 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1009                     device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1010                     device_create_file(&tun->dev->dev, &dev_attr_group))
1011                         printk(KERN_ERR "Failed to create tun sysfs files\n");
1012
1013                 sk->sk_destruct = tun_sock_destruct;
1014
1015                 err = tun_attach(tun, file);
1016                 if (err < 0)
1017                         goto failed;
1018         }
1019
1020         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
1021
1022         if (ifr->ifr_flags & IFF_NO_PI)
1023                 tun->flags |= TUN_NO_PI;
1024         else
1025                 tun->flags &= ~TUN_NO_PI;
1026
1027         if (ifr->ifr_flags & IFF_ONE_QUEUE)
1028                 tun->flags |= TUN_ONE_QUEUE;
1029         else
1030                 tun->flags &= ~TUN_ONE_QUEUE;
1031
1032         if (ifr->ifr_flags & IFF_VNET_HDR)
1033                 tun->flags |= TUN_VNET_HDR;
1034         else
1035                 tun->flags &= ~TUN_VNET_HDR;
1036
1037         /* Make sure persistent devices do not get stuck in
1038          * xoff state.
1039          */
1040         if (netif_running(tun->dev))
1041                 netif_wake_queue(tun->dev);
1042
1043         strcpy(ifr->ifr_name, tun->dev->name);
1044         return 0;
1045
1046  err_free_sk:
1047         sock_put(sk);
1048  err_free_dev:
1049         free_netdev(dev);
1050  failed:
1051         return err;
1052 }
1053
1054 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1055                        struct ifreq *ifr)
1056 {
1057         DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);
1058
1059         strcpy(ifr->ifr_name, tun->dev->name);
1060
1061         ifr->ifr_flags = tun_flags(tun);
1062
1063         return 0;
1064 }
1065
1066 /* This is like a cut-down ethtool ops, except done via tun fd so no
1067  * privs required. */
1068 static int set_offload(struct net_device *dev, unsigned long arg)
1069 {
1070         unsigned int old_features, features;
1071
1072         old_features = dev->features;
1073         /* Unset features, set them as we chew on the arg. */
1074         features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
1075                                     |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6
1076                                     |NETIF_F_UFO));
1077
1078         if (arg & TUN_F_CSUM) {
1079                 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1080                 arg &= ~TUN_F_CSUM;
1081
1082                 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1083                         if (arg & TUN_F_TSO_ECN) {
1084                                 features |= NETIF_F_TSO_ECN;
1085                                 arg &= ~TUN_F_TSO_ECN;
1086                         }
1087                         if (arg & TUN_F_TSO4)
1088                                 features |= NETIF_F_TSO;
1089                         if (arg & TUN_F_TSO6)
1090                                 features |= NETIF_F_TSO6;
1091                         arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1092                 }
1093
1094                 if (arg & TUN_F_UFO) {
1095                         features |= NETIF_F_UFO;
1096                         arg &= ~TUN_F_UFO;
1097                 }
1098         }
1099
1100         /* This gives the user a way to test for new features in future by
1101          * trying to set them. */
1102         if (arg)
1103                 return -EINVAL;
1104
1105         dev->features = features;
1106         if (old_features != dev->features)
1107                 netdev_features_change(dev);
1108
1109         return 0;
1110 }
1111
1112 static long tun_chr_ioctl(struct file *file, unsigned int cmd,
1113                           unsigned long arg)
1114 {
1115         struct tun_file *tfile = file->private_data;
1116         struct tun_struct *tun;
1117         void __user* argp = (void __user*)arg;
1118         struct ifreq ifr;
1119         int sndbuf;
1120         int ret;
1121
1122         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1123                 if (copy_from_user(&ifr, argp, sizeof ifr))
1124                         return -EFAULT;
1125
1126         if (cmd == TUNGETFEATURES) {
1127                 /* Currently this just means: "what IFF flags are valid?".
1128                  * This is needed because we never checked for invalid flags on
1129                  * TUNSETIFF. */
1130                 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1131                                 IFF_VNET_HDR,
1132                                 (unsigned int __user*)argp);
1133         }
1134
1135         rtnl_lock();
1136
1137         tun = __tun_get(tfile);
1138         if (cmd == TUNSETIFF && !tun) {
1139                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1140
1141                 ret = tun_set_iff(tfile->net, file, &ifr);
1142
1143                 if (ret)
1144                         goto unlock;
1145
1146                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
1147                         ret = -EFAULT;
1148                 goto unlock;
1149         }
1150
1151         ret = -EBADFD;
1152         if (!tun)
1153                 goto unlock;
1154
1155         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
1156
1157         ret = 0;
1158         switch (cmd) {
1159         case TUNGETIFF:
1160                 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1161                 if (ret)
1162                         break;
1163
1164                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
1165                         ret = -EFAULT;
1166                 break;
1167
1168         case TUNSETNOCSUM:
1169                 /* Disable/Enable checksum */
1170                 if (arg)
1171                         tun->flags |= TUN_NOCHECKSUM;
1172                 else
1173                         tun->flags &= ~TUN_NOCHECKSUM;
1174
1175                 DBG(KERN_INFO "%s: checksum %s\n",
1176                     tun->dev->name, arg ? "disabled" : "enabled");
1177                 break;
1178
1179         case TUNSETPERSIST:
1180                 /* Disable/Enable persist mode */
1181                 if (arg)
1182                         tun->flags |= TUN_PERSIST;
1183                 else
1184                         tun->flags &= ~TUN_PERSIST;
1185
1186                 DBG(KERN_INFO "%s: persist %s\n",
1187                     tun->dev->name, arg ? "enabled" : "disabled");
1188                 break;
1189
1190         case TUNSETOWNER:
1191                 /* Set owner of the device */
1192                 tun->owner = (uid_t) arg;
1193
1194                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
1195                 break;
1196
1197         case TUNSETGROUP:
1198                 /* Set group of the device */
1199                 tun->group= (gid_t) arg;
1200
1201                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
1202                 break;
1203
1204         case TUNSETLINK:
1205                 /* Only allow setting the type when the interface is down */
1206                 if (tun->dev->flags & IFF_UP) {
1207                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
1208                                 tun->dev->name);
1209                         ret = -EBUSY;
1210                 } else {
1211                         tun->dev->type = (int) arg;
1212                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
1213                         ret = 0;
1214                 }
1215                 break;
1216
1217 #ifdef TUN_DEBUG
1218         case TUNSETDEBUG:
1219                 tun->debug = arg;
1220                 break;
1221 #endif
1222         case TUNSETOFFLOAD:
1223                 ret = set_offload(tun->dev, arg);
1224                 break;
1225
1226         case TUNSETTXFILTER:
1227                 /* Can be set only for TAPs */
1228                 ret = -EINVAL;
1229                 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1230                         break;
1231                 ret = update_filter(&tun->txflt, (void __user *)arg);
1232                 break;
1233
1234         case SIOCGIFHWADDR:
1235                 /* Get hw addres */
1236                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1237                 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1238                 if (copy_to_user(argp, &ifr, sizeof ifr))
1239                         ret = -EFAULT;
1240                 break;
1241
1242         case SIOCSIFHWADDR:
1243                 /* Set hw address */
1244                 DBG(KERN_DEBUG "%s: set hw address: %pM\n",
1245                         tun->dev->name, ifr.ifr_hwaddr.sa_data);
1246
1247                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1248                 break;
1249
1250         case TUNGETSNDBUF:
1251                 sndbuf = tun->socket.sk->sk_sndbuf;
1252                 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1253                         ret = -EFAULT;
1254                 break;
1255
1256         case TUNSETSNDBUF:
1257                 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1258                         ret = -EFAULT;
1259                         break;
1260                 }
1261
1262                 tun->socket.sk->sk_sndbuf = sndbuf;
1263                 break;
1264
1265         default:
1266                 ret = -EINVAL;
1267                 break;
1268         };
1269
1270 unlock:
1271         rtnl_unlock();
1272         if (tun)
1273                 tun_put(tun);
1274         return ret;
1275 }
1276
1277 static int tun_chr_fasync(int fd, struct file *file, int on)
1278 {
1279         struct tun_struct *tun = tun_get(file);
1280         int ret;
1281
1282         if (!tun)
1283                 return -EBADFD;
1284
1285         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
1286
1287         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1288                 goto out;
1289
1290         if (on) {
1291                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1292                 if (ret)
1293                         goto out;
1294                 tun->flags |= TUN_FASYNC;
1295         } else
1296                 tun->flags &= ~TUN_FASYNC;
1297         ret = 0;
1298 out:
1299         tun_put(tun);
1300         return ret;
1301 }
1302
1303 static int tun_chr_open(struct inode *inode, struct file * file)
1304 {
1305         struct tun_file *tfile;
1306
1307         DBG1(KERN_INFO "tunX: tun_chr_open\n");
1308
1309         tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1310         if (!tfile)
1311                 return -ENOMEM;
1312         atomic_set(&tfile->count, 0);
1313         tfile->tun = NULL;
1314         tfile->net = get_net(current->nsproxy->net_ns);
1315         file->private_data = tfile;
1316         return 0;
1317 }
1318
1319 static int tun_chr_close(struct inode *inode, struct file *file)
1320 {
1321         struct tun_file *tfile = file->private_data;
1322         struct tun_struct *tun;
1323
1324         tun = __tun_get(tfile);
1325         if (tun) {
1326                 struct net_device *dev = tun->dev;
1327
1328                 DBG(KERN_INFO "%s: tun_chr_close\n", dev->name);
1329
1330                 __tun_detach(tun);
1331
1332                 /* If desireable, unregister the netdevice. */
1333                 if (!(tun->flags & TUN_PERSIST)) {
1334                         rtnl_lock();
1335                         if (dev->reg_state == NETREG_REGISTERED)
1336                                 unregister_netdevice(dev);
1337                         rtnl_unlock();
1338                 }
1339         }
1340
1341         tun = tfile->tun;
1342         if (tun)
1343                 sock_put(tun->socket.sk);
1344
1345         put_net(tfile->net);
1346         kfree(tfile);
1347
1348         return 0;
1349 }
1350
1351 static const struct file_operations tun_fops = {
1352         .owner  = THIS_MODULE,
1353         .llseek = no_llseek,
1354         .read  = do_sync_read,
1355         .aio_read  = tun_chr_aio_read,
1356         .write = do_sync_write,
1357         .aio_write = tun_chr_aio_write,
1358         .poll   = tun_chr_poll,
1359         .unlocked_ioctl = tun_chr_ioctl,
1360         .open   = tun_chr_open,
1361         .release = tun_chr_close,
1362         .fasync = tun_chr_fasync
1363 };
1364
1365 static struct miscdevice tun_miscdev = {
1366         .minor = TUN_MINOR,
1367         .name = "tun",
1368         .nodename = "net/tun",
1369         .fops = &tun_fops,
1370 };
1371
1372 /* ethtool interface */
1373
1374 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1375 {
1376         cmd->supported          = 0;
1377         cmd->advertising        = 0;
1378         cmd->speed              = SPEED_10;
1379         cmd->duplex             = DUPLEX_FULL;
1380         cmd->port               = PORT_TP;
1381         cmd->phy_address        = 0;
1382         cmd->transceiver        = XCVR_INTERNAL;
1383         cmd->autoneg            = AUTONEG_DISABLE;
1384         cmd->maxtxpkt           = 0;
1385         cmd->maxrxpkt           = 0;
1386         return 0;
1387 }
1388
1389 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1390 {
1391         struct tun_struct *tun = netdev_priv(dev);
1392
1393         strcpy(info->driver, DRV_NAME);
1394         strcpy(info->version, DRV_VERSION);
1395         strcpy(info->fw_version, "N/A");
1396
1397         switch (tun->flags & TUN_TYPE_MASK) {
1398         case TUN_TUN_DEV:
1399                 strcpy(info->bus_info, "tun");
1400                 break;
1401         case TUN_TAP_DEV:
1402                 strcpy(info->bus_info, "tap");
1403                 break;
1404         }
1405 }
1406
1407 static u32 tun_get_msglevel(struct net_device *dev)
1408 {
1409 #ifdef TUN_DEBUG
1410         struct tun_struct *tun = netdev_priv(dev);
1411         return tun->debug;
1412 #else
1413         return -EOPNOTSUPP;
1414 #endif
1415 }
1416
1417 static void tun_set_msglevel(struct net_device *dev, u32 value)
1418 {
1419 #ifdef TUN_DEBUG
1420         struct tun_struct *tun = netdev_priv(dev);
1421         tun->debug = value;
1422 #endif
1423 }
1424
1425 static u32 tun_get_link(struct net_device *dev)
1426 {
1427         struct tun_struct *tun = netdev_priv(dev);
1428         return !!tun->tfile;
1429 }
1430
1431 static u32 tun_get_rx_csum(struct net_device *dev)
1432 {
1433         struct tun_struct *tun = netdev_priv(dev);
1434         return (tun->flags & TUN_NOCHECKSUM) == 0;
1435 }
1436
1437 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1438 {
1439         struct tun_struct *tun = netdev_priv(dev);
1440         if (data)
1441                 tun->flags &= ~TUN_NOCHECKSUM;
1442         else
1443                 tun->flags |= TUN_NOCHECKSUM;
1444         return 0;
1445 }
1446
1447 static const struct ethtool_ops tun_ethtool_ops = {
1448         .get_settings   = tun_get_settings,
1449         .get_drvinfo    = tun_get_drvinfo,
1450         .get_msglevel   = tun_get_msglevel,
1451         .set_msglevel   = tun_set_msglevel,
1452         .get_link       = tun_get_link,
1453         .get_rx_csum    = tun_get_rx_csum,
1454         .set_rx_csum    = tun_set_rx_csum
1455 };
1456
1457
1458 static int __init tun_init(void)
1459 {
1460         int ret = 0;
1461
1462         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1463         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1464
1465         ret = rtnl_link_register(&tun_link_ops);
1466         if (ret) {
1467                 printk(KERN_ERR "tun: Can't register link_ops\n");
1468                 goto err_linkops;
1469         }
1470
1471         ret = misc_register(&tun_miscdev);
1472         if (ret) {
1473                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1474                 goto err_misc;
1475         }
1476         return  0;
1477 err_misc:
1478         rtnl_link_unregister(&tun_link_ops);
1479 err_linkops:
1480         return ret;
1481 }
1482
1483 static void tun_cleanup(void)
1484 {
1485         misc_deregister(&tun_miscdev);
1486         rtnl_link_unregister(&tun_link_ops);
1487 }
1488
1489 module_init(tun_init);
1490 module_exit(tun_cleanup);
1491 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1492 MODULE_AUTHOR(DRV_COPYRIGHT);
1493 MODULE_LICENSE("GPL");
1494 MODULE_ALIAS_MISCDEV(TUN_MINOR);