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