drivers/net/tun.c

   1 /*
   2  *  TUN - Universal TUN/TAP device driver.
   3  *  Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
  16  */
  17
  18 /*
  19  *  Changes:
  20  *
  21  *  Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
  22  *    Add TUNSETLINK ioctl to set the link encapsulation
  23  *
  24  *  Mark Smith <markzzzsmith@yahoo.com.au>
  25  *    Use random_ether_addr() for tap MAC address.
  26  *
  27  *  Harald Roelle <harald.roelle@ifi.lmu.de>  2004/04/20
  28  *    Fixes in packet dropping, queue length setting and queue wakeup.
  29  *    Increased default tx queue length.
  30  *    Added ethtool API.
  31  *    Minor cleanups
  32  *
  33  *  Daniel Podlejski <underley@underley.eu.org>
  34  *    Modifications for 2.3.99-pre5 kernel.
  35  */
  36
  37 #define DRV_NAME        "tun"
  38 #define DRV_VERSION     "1.6"
  39 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
  40 #define DRV_COPYRIGHT   "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
  41
  42 #include <linux/module.h>
  43 #include <linux/errno.h>
  44 #include <linux/kernel.h>
  45 #include <linux/major.h>
  46 #include <linux/slab.h>
  47 #include <linux/smp_lock.h>
  48 #include <linux/poll.h>
  49 #include <linux/fcntl.h>
  50 #include <linux/init.h>
  51 #include <linux/skbuff.h>
  52 #include <linux/netdevice.h>
  53 #include <linux/etherdevice.h>
  54 #include <linux/miscdevice.h>
  55 #include <linux/ethtool.h>
  56 #include <linux/rtnetlink.h>
  57 #include <linux/if.h>
  58 #include <linux/if_arp.h>
  59 #include <linux/if_ether.h>
  60 #include <linux/if_tun.h>
  61 #include <linux/crc32.h>
  62 #include <linux/nsproxy.h>
  63 #include <linux/virtio_net.h>
  64 #include <net/net_namespace.h>
  65 #include <net/netns/generic.h>
  66 #include <net/rtnetlink.h>
  67 #include <net/sock.h>
  68
  69 #include <asm/system.h>
  70 #include <asm/uaccess.h>
  71
  72 /* Uncomment to enable debugging */
  73 /* #define TUN_DEBUG 1 */
  74
  75 #ifdef TUN_DEBUG
  76 static int debug;
  77
  78 #define DBG  if(tun->debug)printk
  79 #define DBG1 if(debug==2)printk
  80 #else
  81 #define DBG( a... )
  82 #define DBG1( a... )
  83 #endif
  84
  85 #define FLT_EXACT_COUNT 8
  86 struct tap_filter {
  87         unsigned int    count;    /* Number of addrs. Zero means disabled */
  88         u32             mask[2];  /* Mask of the hashed addrs */
  89         unsigned char   addr[FLT_EXACT_COUNT][ETH_ALEN];
  90 };
  91
  92 struct tun_file {
  93         atomic_t count;
  94         struct tun_struct *tun;
  95         struct net *net;
  96 };
  97
  98 struct tun_sock;
  99
 100 struct tun_struct {
 101         struct tun_file         *tfile;
 102         unsigned int            flags;
 103         uid_t                   owner;
 104         gid_t                   group;
 105
 106         struct net_device       *dev;
 107         struct fasync_struct    *fasync;
 108
 109         struct tap_filter       txflt;
 110         struct socket           socket;
 111
 112 #ifdef TUN_DEBUG
 113         int debug;
 114 #endif
 115 };
 116
 117 struct tun_sock {
 118         struct sock             sk;
 119         struct tun_struct       *tun;
 120 };
 121
 122 static inline struct tun_sock *tun_sk(struct sock *sk)
 123 {
 124         return container_of(sk, struct tun_sock, sk);
 125 }
 126
 127 static int tun_attach(struct tun_struct *tun, struct file *file)
 128 {
 129         struct tun_file *tfile = file->private_data;
 130         const struct cred *cred = current_cred();
 131         int err;
 132
 133         ASSERT_RTNL();
 134
 135         /* Check permissions */
 136         if (((tun->owner != -1 && cred->euid != tun->owner) ||
 137              (tun->group != -1 && !in_egroup_p(tun->group))) &&
 138                 !capable(CAP_NET_ADMIN))
 139                 return -EPERM;
 140
 141         netif_tx_lock_bh(tun->dev);
 142
 143         err = -EINVAL;
 144         if (tfile->tun)
 145                 goto out;
 146
 147         err = -EBUSY;
 148         if (tun->tfile)
 149                 goto out;
 150
 151         err = 0;
 152         tfile->tun = tun;
 153         tun->tfile = tfile;
 154         dev_hold(tun->dev);
 155         sock_hold(tun->socket.sk);
 156         atomic_inc(&tfile->count);
 157
 158 out:
 159         netif_tx_unlock_bh(tun->dev);
 160         return err;
 161 }
 162
 163 static void __tun_detach(struct tun_struct *tun)
 164 {
 165         /* Detach from net device */
 166         netif_tx_lock_bh(tun->dev);
 167         tun->tfile = NULL;
 168         netif_tx_unlock_bh(tun->dev);
 169
 170         /* Drop read queue */
 171         skb_queue_purge(&tun->socket.sk->sk_receive_queue);
 172
 173         /* Drop the extra count on the net device */
 174         dev_put(tun->dev);
 175 }
 176
 177 static void tun_detach(struct tun_struct *tun)
 178 {
 179         rtnl_lock();
 180         __tun_detach(tun);
 181         rtnl_unlock();
 182 }
 183
 184 static struct tun_struct *__tun_get(struct tun_file *tfile)
 185 {
 186         struct tun_struct *tun = NULL;
 187
 188         if (atomic_inc_not_zero(&tfile->count))
 189                 tun = tfile->tun;
 190
 191         return tun;
 192 }
 193
 194 static struct tun_struct *tun_get(struct file *file)
 195 {
 196         return __tun_get(file->private_data);
 197 }
 198
 199 static void tun_put(struct tun_struct *tun)
 200 {
 201         struct tun_file *tfile = tun->tfile;
 202
 203         if (atomic_dec_and_test(&tfile->count))
 204                 tun_detach(tfile->tun);
 205 }
 206
 207 /* TAP filterting */
 208 static void addr_hash_set(u32 *mask, const u8 *addr)
 209 {
 210         int n = ether_crc(ETH_ALEN, addr) >> 26;
 211         mask[n >> 5] |= (1 << (n & 31));
 212 }
 213
 214 static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
 215 {
 216         int n = ether_crc(ETH_ALEN, addr) >> 26;
 217         return mask[n >> 5] & (1 << (n & 31));
 218 }
 219
 220 static int update_filter(struct tap_filter *filter, void __user *arg)
 221 {
 222         struct { u8 u[ETH_ALEN]; } *addr;
 223         struct tun_filter uf;
 224         int err, alen, n, nexact;
 225
 226         if (copy_from_user(&uf, arg, sizeof(uf)))
 227                 return -EFAULT;
 228
 229         if (!uf.count) {
 230                 /* Disabled */
 231                 filter->count = 0;
 232                 return 0;
 233         }
 234
 235         alen = ETH_ALEN * uf.count;
 236         addr = kmalloc(alen, GFP_KERNEL);
 237         if (!addr)
 238                 return -ENOMEM;
 239
 240         if (copy_from_user(addr, arg + sizeof(uf), alen)) {
 241                 err = -EFAULT;
 242                 goto done;
 243         }
 244
 245         /* The filter is updated without holding any locks. Which is
 246          * perfectly safe. We disable it first and in the worst
 247          * case we'll accept a few undesired packets. */
 248         filter->count = 0;
 249         wmb();
 250
 251         /* Use first set of addresses as an exact filter */
 252         for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
 253                 memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
 254
 255         nexact = n;
 256
 257         /* Remaining multicast addresses are hashed,
 258          * unicast will leave the filter disabled. */
 259         memset(filter->mask, 0, sizeof(filter->mask));
 260         for (; n < uf.count; n++) {
 261                 if (!is_multicast_ether_addr(addr[n].u)) {
 262                         err = 0; /* no filter */
 263                         goto done;
 264                 }
 265                 addr_hash_set(filter->mask, addr[n].u);
 266         }
 267
 268         /* For ALLMULTI just set the mask to all ones.
 269          * This overrides the mask populated above. */
 270         if ((uf.flags & TUN_FLT_ALLMULTI))
 271                 memset(filter->mask, ~0, sizeof(filter->mask));
 272
 273         /* Now enable the filter */
 274         wmb();
 275         filter->count = nexact;
 276
 277         /* Return the number of exact filters */
 278         err = nexact;
 279
 280 done:
 281         kfree(addr);
 282         return err;
 283 }
 284
 285 /* Returns: 0 - drop, !=0 - accept */
 286 static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
 287 {
 288         /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
 289          * at this point. */
 290         struct ethhdr *eh = (struct ethhdr *) skb->data;
 291         int i;
 292
 293         /* Exact match */
 294         for (i = 0; i < filter->count; i++)
 295                 if (!compare_ether_addr(eh->h_dest, filter->addr[i]))
 296                         return 1;
 297
 298         /* Inexact match (multicast only) */
 299         if (is_multicast_ether_addr(eh->h_dest))
 300                 return addr_hash_test(filter->mask, eh->h_dest);
 301
 302         return 0;
 303 }
 304
 305 /*
 306  * Checks whether the packet is accepted or not.
 307  * Returns: 0 - drop, !=0 - accept
 308  */
 309 static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
 310 {
 311         if (!filter->count)
 312                 return 1;
 313
 314         return run_filter(filter, skb);
 315 }
 316
 317 /* Network device part of the driver */
 318
 319 static const struct ethtool_ops tun_ethtool_ops;
 320
 321 /* Net device detach from fd. */
 322 static void tun_net_uninit(struct net_device *dev)
 323 {
 324         struct tun_struct *tun = netdev_priv(dev);
 325         struct tun_file *tfile = tun->tfile;
 326
 327         /* Inform the methods they need to stop using the dev.
 328          */
 329         if (tfile) {
 330                 wake_up_all(&tun->socket.wait);
 331                 if (atomic_dec_and_test(&tfile->count))
 332                         __tun_detach(tun);
 333         }
 334 }
 335
 336 static void tun_free_netdev(struct net_device *dev)
 337 {
 338         struct tun_struct *tun = netdev_priv(dev);
 339
 340         sock_put(tun->socket.sk);
 341 }
 342
 343 /* Net device open. */
 344 static int tun_net_open(struct net_device *dev)
 345 {
 346         netif_start_queue(dev);
 347         return 0;
 348 }
 349
 350 /* Net device close. */
 351 static int tun_net_close(struct net_device *dev)
 352 {
 353         netif_stop_queue(dev);
 354         return 0;
 355 }
 356
 357 /* Net device start xmit */
 358 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 359 {
 360         struct tun_struct *tun = netdev_priv(dev);
 361
 362         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
 363
 364         /* Drop packet if interface is not attached */
 365         if (!tun->tfile)
 366                 goto drop;
 367
 368         /* Drop if the filter does not like it.
 369          * This is a noop if the filter is disabled.
 370          * Filter can be enabled only for the TAP devices. */
 371         if (!check_filter(&tun->txflt, skb))
 372                 goto drop;
 373
 374         if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
 375                 if (!(tun->flags & TUN_ONE_QUEUE)) {
 376                         /* Normal queueing mode. */
 377                         /* Packet scheduler handles dropping of further packets. */
 378                         netif_stop_queue(dev);
 379
 380                         /* We won't see all dropped packets individually, so overrun
 381                          * error is more appropriate. */
 382                         dev->stats.tx_fifo_errors++;
 383                 } else {
 384                         /* Single queue mode.
 385                          * Driver handles dropping of all packets itself. */
 386                         goto drop;
 387                 }
 388         }
 389
 390         /* Enqueue packet */
 391         skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
 392         dev->trans_start = jiffies;
 393
 394         /* Notify and wake up reader process */
 395         if (tun->flags & TUN_FASYNC)
 396                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
 397         wake_up_interruptible(&tun->socket.wait);
 398         return NETDEV_TX_OK;
 399
 400 drop:
 401         dev->stats.tx_dropped++;
 402         kfree_skb(skb);
 403         return NETDEV_TX_OK;
 404 }
 405
 406 static void tun_net_mclist(struct net_device *dev)
 407 {
 408         /*
 409          * This callback is supposed to deal with mc filter in
 410          * _rx_ path and has nothing to do with the _tx_ path.
 411          * In rx path we always accept everything userspace gives us.
 412          */
 413         return;
 414 }
 415
 416 #define MIN_MTU 68
 417 #define MAX_MTU 65535
 418
 419 static int
 420 tun_net_change_mtu(struct net_device *dev, int new_mtu)
 421 {
 422         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
 423                 return -EINVAL;
 424         dev->mtu = new_mtu;
 425         return 0;
 426 }
 427
 428 static const struct net_device_ops tun_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 };
 435
 436 static const struct net_device_ops tap_netdev_ops = {
 437         .ndo_uninit             = tun_net_uninit,
 438         .ndo_open               = tun_net_open,
 439         .ndo_stop               = tun_net_close,
 440         .ndo_start_xmit         = tun_net_xmit,
 441         .ndo_change_mtu         = tun_net_change_mtu,
 442         .ndo_set_multicast_list = tun_net_mclist,
 443         .ndo_set_mac_address    = eth_mac_addr,
 444         .ndo_validate_addr      = eth_validate_addr,
 445 };
 446
 447 /* Initialize net device. */
 448 static void tun_net_init(struct net_device *dev)
 449 {
 450         struct tun_struct *tun = netdev_priv(dev);
 451
 452         switch (tun->flags & TUN_TYPE_MASK) {
 453         case TUN_TUN_DEV:
 454                 dev->netdev_ops = &tun_netdev_ops;
 455
 456                 /* Point-to-Point TUN Device */
 457                 dev->hard_header_len = 0;
 458                 dev->addr_len = 0;
 459                 dev->mtu = 1500;
 460
 461                 /* Zero header length */
 462                 dev->type = ARPHRD_NONE;
 463                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 464                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 465                 break;
 466
 467         case TUN_TAP_DEV:
 468                 dev->netdev_ops = &tap_netdev_ops;
 469                 /* Ethernet TAP Device */
 470                 ether_setup(dev);
 471
 472                 random_ether_addr(dev->dev_addr);
 473
 474                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 475                 break;
 476         }
 477 }
 478
 479 /* Character device part */
 480
 481 /* Poll */
 482 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
 483 {
 484         struct tun_file *tfile = file->private_data;
 485         struct tun_struct *tun = __tun_get(tfile);
 486         struct sock *sk;
 487         unsigned int mask = 0;
 488
 489         if (!tun)
 490                 return POLLERR;
 491
 492         sk = tun->socket.sk;
 493
 494         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
 495
 496         poll_wait(file, &tun->socket.wait, wait);
 497
 498         if (!skb_queue_empty(&sk->sk_receive_queue))
 499                 mask |= POLLIN | POLLRDNORM;
 500
 501         if (sock_writeable(sk) ||
 502             (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
 503              sock_writeable(sk)))
 504                 mask |= POLLOUT | POLLWRNORM;
 505
 506         if (tun->dev->reg_state != NETREG_REGISTERED)
 507                 mask = POLLERR;
 508
 509         tun_put(tun);
 510         return mask;
 511 }
 512
 513 /* prepad is the amount to reserve at front.  len is length after that.
 514  * linear is a hint as to how much to copy (usually headers). */
 515 static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
 516                                             size_t prepad, size_t len,
 517                                             size_t linear, int noblock)
 518 {
 519         struct sock *sk = tun->socket.sk;
 520         struct sk_buff *skb;
 521         int err;
 522
 523         /* Under a page?  Don't bother with paged skb. */
 524         if (prepad + len < PAGE_SIZE || !linear)
 525                 linear = len;
 526
 527         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
 528                                    &err);
 529         if (!skb)
 530                 return ERR_PTR(err);
 531
 532         skb_reserve(skb, prepad);
 533         skb_put(skb, linear);
 534         skb->data_len = len - linear;
 535         skb->len += len - linear;
 536
 537         return skb;
 538 }
 539
 540 /* Get packet from user space buffer */
 541 static __inline__ ssize_t tun_get_user(struct tun_struct *tun,
 542                                        const struct iovec *iv, size_t count,
 543                                        int noblock)
 544 {
 545         struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
 546         struct sk_buff *skb;
 547         size_t len = count, align = 0;
 548         struct virtio_net_hdr gso = { 0 };
 549         int offset = 0;
 550
 551         if (!(tun->flags & TUN_NO_PI)) {
 552                 if ((len -= sizeof(pi)) > count)
 553                         return -EINVAL;
 554
 555                 if (memcpy_fromiovecend((void *)&pi, iv, 0, sizeof(pi)))
 556                         return -EFAULT;
 557                 offset += sizeof(pi);
 558         }
 559
 560         if (tun->flags & TUN_VNET_HDR) {
 561                 if ((len -= sizeof(gso)) > count)
 562                         return -EINVAL;
 563
 564                 if (memcpy_fromiovecend((void *)&gso, iv, offset, sizeof(gso)))
 565                         return -EFAULT;
 566
 567                 if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
 568                     gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
 569                         gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
 570
 571                 if (gso.hdr_len > len)
 572                         return -EINVAL;
 573                 offset += sizeof(gso);
 574         }
 575
 576         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
 577                 align = NET_IP_ALIGN;
 578                 if (unlikely(len < ETH_HLEN ||
 579                              (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
 580                         return -EINVAL;
 581         }
 582
 583         skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
 584         if (IS_ERR(skb)) {
 585                 if (PTR_ERR(skb) != -EAGAIN)
 586                         tun->dev->stats.rx_dropped++;
 587                 return PTR_ERR(skb);
 588         }
 589
 590         if (skb_copy_datagram_from_iovec(skb, 0, iv, offset, len)) {
 591                 tun->dev->stats.rx_dropped++;
 592                 kfree_skb(skb);
 593                 return -EFAULT;
 594         }
 595
 596         if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
 597                 if (!skb_partial_csum_set(skb, gso.csum_start,
 598                                           gso.csum_offset)) {
 599                         tun->dev->stats.rx_frame_errors++;
 600                         kfree_skb(skb);
 601                         return -EINVAL;
 602                 }
 603         } else if (tun->flags & TUN_NOCHECKSUM)
 604                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 605
 606         switch (tun->flags & TUN_TYPE_MASK) {
 607         case TUN_TUN_DEV:
 608                 if (tun->flags & TUN_NO_PI) {
 609                         switch (skb->data[0] & 0xf0) {
 610                         case 0x40:
 611                                 pi.proto = htons(ETH_P_IP);
 612                                 break;
 613                         case 0x60:
 614                                 pi.proto = htons(ETH_P_IPV6);
 615                                 break;
 616                         default:
 617                                 tun->dev->stats.rx_dropped++;
 618                                 kfree_skb(skb);
 619                                 return -EINVAL;
 620                         }
 621                 }
 622
 623                 skb_reset_mac_header(skb);
 624                 skb->protocol = pi.proto;
 625                 skb->dev = tun->dev;
 626                 break;
 627         case TUN_TAP_DEV:
 628                 skb->protocol = eth_type_trans(skb, tun->dev);
 629                 break;
 630         };
 631
 632         if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
 633                 pr_debug("GSO!\n");
 634                 switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
 635                 case VIRTIO_NET_HDR_GSO_TCPV4:
 636                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
 637                         break;
 638                 case VIRTIO_NET_HDR_GSO_TCPV6:
 639                         skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
 640                         break;
 641                 case VIRTIO_NET_HDR_GSO_UDP:
 642                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
 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 if (sinfo->gso_type & SKB_GSO_UDP)
 730                                 gso.gso_type = VIRTIO_NET_HDR_GSO_UDP;
 731                         else
 732                                 BUG();
 733                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
 734                                 gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
 735                 } else
 736                         gso.gso_type = VIRTIO_NET_HDR_GSO_NONE;
 737
 738                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
 739                         gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 740                         gso.csum_start = skb->csum_start - skb_headroom(skb);
 741                         gso.csum_offset = skb->csum_offset;
 742                 } /* else everything is zero */
 743
 744                 if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
 745                                                sizeof(gso))))
 746                         return -EFAULT;
 747                 total += sizeof(gso);
 748         }
 749
 750         len = min_t(int, skb->len, len);
 751
 752         skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
 753         total += len;
 754
 755         tun->dev->stats.tx_packets++;
 756         tun->dev->stats.tx_bytes += len;
 757
 758         return total;
 759 }
 760
 761 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
 762                             unsigned long count, loff_t pos)
 763 {
 764         struct file *file = iocb->ki_filp;
 765         struct tun_file *tfile = file->private_data;
 766         struct tun_struct *tun = __tun_get(tfile);
 767         DECLARE_WAITQUEUE(wait, current);
 768         struct sk_buff *skb;
 769         ssize_t len, ret = 0;
 770
 771         if (!tun)
 772                 return -EBADFD;
 773
 774         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
 775
 776         len = iov_length(iv, count);
 777         if (len < 0) {
 778                 ret = -EINVAL;
 779                 goto out;
 780         }
 781
 782         add_wait_queue(&tun->socket.wait, &wait);
 783         while (len) {
 784                 current->state = TASK_INTERRUPTIBLE;
 785
 786                 /* Read frames from the queue */
 787                 if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
 788                         if (file->f_flags & O_NONBLOCK) {
 789                                 ret = -EAGAIN;
 790                                 break;
 791                         }
 792                         if (signal_pending(current)) {
 793                                 ret = -ERESTARTSYS;
 794                                 break;
 795                         }
 796                         if (tun->dev->reg_state != NETREG_REGISTERED) {
 797                                 ret = -EIO;
 798                                 break;
 799                         }
 800
 801                         /* Nothing to read, let's sleep */
 802                         schedule();
 803                         continue;
 804                 }
 805                 netif_wake_queue(tun->dev);
 806
 807                 ret = tun_put_user(tun, skb, iv, len);
 808                 kfree_skb(skb);
 809                 break;
 810         }
 811
 812         current->state = TASK_RUNNING;
 813         remove_wait_queue(&tun->socket.wait, &wait);
 814
 815 out:
 816         tun_put(tun);
 817         return ret;
 818 }
 819
 820 static void tun_setup(struct net_device *dev)
 821 {
 822         struct tun_struct *tun = netdev_priv(dev);
 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                 container_of(sk, struct tun_sock, sk)->tun = tun;
 990
 991                 tun_net_init(dev);
 992
 993                 if (strchr(dev->name, '%')) {
 994                         err = dev_alloc_name(dev, dev->name);
 995                         if (err < 0)
 996                                 goto err_free_sk;
 997                 }
 998
 999                 err = register_netdevice(tun->dev);
1000                 if (err < 0)
1001                         goto err_free_sk;
1002
1003                 if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
1004                     device_create_file(&tun->dev->dev, &dev_attr_owner) ||
1005                     device_create_file(&tun->dev->dev, &dev_attr_group))
1006                         printk(KERN_ERR "Failed to create tun sysfs files\n");
1007
1008                 sk->sk_destruct = tun_sock_destruct;
1009
1010                 err = tun_attach(tun, file);
1011                 if (err < 0)
1012                         goto failed;
1013         }
1014
1015         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
1016
1017         if (ifr->ifr_flags & IFF_NO_PI)
1018                 tun->flags |= TUN_NO_PI;
1019         else
1020                 tun->flags &= ~TUN_NO_PI;
1021
1022         if (ifr->ifr_flags & IFF_ONE_QUEUE)
1023                 tun->flags |= TUN_ONE_QUEUE;
1024         else
1025                 tun->flags &= ~TUN_ONE_QUEUE;
1026
1027         if (ifr->ifr_flags & IFF_VNET_HDR)
1028                 tun->flags |= TUN_VNET_HDR;
1029         else
1030                 tun->flags &= ~TUN_VNET_HDR;
1031
1032         /* Make sure persistent devices do not get stuck in
1033          * xoff state.
1034          */
1035         if (netif_running(tun->dev))
1036                 netif_wake_queue(tun->dev);
1037
1038         strcpy(ifr->ifr_name, tun->dev->name);
1039         return 0;
1040
1041  err_free_sk:
1042         sock_put(sk);
1043  err_free_dev:
1044         free_netdev(dev);
1045  failed:
1046         return err;
1047 }
1048
1049 static int tun_get_iff(struct net *net, struct tun_struct *tun,
1050                        struct ifreq *ifr)
1051 {
1052         DBG(KERN_INFO "%s: tun_get_iff\n", tun->dev->name);
1053
1054         strcpy(ifr->ifr_name, tun->dev->name);
1055
1056         ifr->ifr_flags = tun_flags(tun);
1057
1058         return 0;
1059 }
1060
1061 /* This is like a cut-down ethtool ops, except done via tun fd so no
1062  * privs required. */
1063 static int set_offload(struct net_device *dev, unsigned long arg)
1064 {
1065         unsigned int old_features, features;
1066
1067         old_features = dev->features;
1068         /* Unset features, set them as we chew on the arg. */
1069         features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST
1070                                     |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6
1071                                     |NETIF_F_UFO));
1072
1073         if (arg & TUN_F_CSUM) {
1074                 features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
1075                 arg &= ~TUN_F_CSUM;
1076
1077                 if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
1078                         if (arg & TUN_F_TSO_ECN) {
1079                                 features |= NETIF_F_TSO_ECN;
1080                                 arg &= ~TUN_F_TSO_ECN;
1081                         }
1082                         if (arg & TUN_F_TSO4)
1083                                 features |= NETIF_F_TSO;
1084                         if (arg & TUN_F_TSO6)
1085                                 features |= NETIF_F_TSO6;
1086                         arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
1087                 }
1088
1089                 if (arg & TUN_F_UFO) {
1090                         features |= NETIF_F_UFO;
1091                         arg &= ~TUN_F_UFO;
1092                 }
1093         }
1094
1095         /* This gives the user a way to test for new features in future by
1096          * trying to set them. */
1097         if (arg)
1098                 return -EINVAL;
1099
1100         dev->features = features;
1101         if (old_features != dev->features)
1102                 netdev_features_change(dev);
1103
1104         return 0;
1105 }
1106
1107 static long tun_chr_ioctl(struct file *file, unsigned int cmd,
1108                           unsigned long arg)
1109 {
1110         struct tun_file *tfile = file->private_data;
1111         struct tun_struct *tun;
1112         void __user* argp = (void __user*)arg;
1113         struct ifreq ifr;
1114         int sndbuf;
1115         int ret;
1116
1117         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
1118                 if (copy_from_user(&ifr, argp, sizeof ifr))
1119                         return -EFAULT;
1120
1121         if (cmd == TUNGETFEATURES) {
1122                 /* Currently this just means: "what IFF flags are valid?".
1123                  * This is needed because we never checked for invalid flags on
1124                  * TUNSETIFF. */
1125                 return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
1126                                 IFF_VNET_HDR,
1127                                 (unsigned int __user*)argp);
1128         }
1129
1130         rtnl_lock();
1131
1132         tun = __tun_get(tfile);
1133         if (cmd == TUNSETIFF && !tun) {
1134                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
1135
1136                 ret = tun_set_iff(tfile->net, file, &ifr);
1137
1138                 if (ret)
1139                         goto unlock;
1140
1141                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
1142                         ret = -EFAULT;
1143                 goto unlock;
1144         }
1145
1146         ret = -EBADFD;
1147         if (!tun)
1148                 goto unlock;
1149
1150         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
1151
1152         ret = 0;
1153         switch (cmd) {
1154         case TUNGETIFF:
1155                 ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
1156                 if (ret)
1157                         break;
1158
1159                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
1160                         ret = -EFAULT;
1161                 break;
1162
1163         case TUNSETNOCSUM:
1164                 /* Disable/Enable checksum */
1165                 if (arg)
1166                         tun->flags |= TUN_NOCHECKSUM;
1167                 else
1168                         tun->flags &= ~TUN_NOCHECKSUM;
1169
1170                 DBG(KERN_INFO "%s: checksum %s\n",
1171                     tun->dev->name, arg ? "disabled" : "enabled");
1172                 break;
1173
1174         case TUNSETPERSIST:
1175                 /* Disable/Enable persist mode */
1176                 if (arg)
1177                         tun->flags |= TUN_PERSIST;
1178                 else
1179                         tun->flags &= ~TUN_PERSIST;
1180
1181                 DBG(KERN_INFO "%s: persist %s\n",
1182                     tun->dev->name, arg ? "enabled" : "disabled");
1183                 break;
1184
1185         case TUNSETOWNER:
1186                 /* Set owner of the device */
1187                 tun->owner = (uid_t) arg;
1188
1189                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
1190                 break;
1191
1192         case TUNSETGROUP:
1193                 /* Set group of the device */
1194                 tun->group= (gid_t) arg;
1195
1196                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
1197                 break;
1198
1199         case TUNSETLINK:
1200                 /* Only allow setting the type when the interface is down */
1201                 if (tun->dev->flags & IFF_UP) {
1202                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
1203                                 tun->dev->name);
1204                         ret = -EBUSY;
1205                 } else {
1206                         tun->dev->type = (int) arg;
1207                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
1208                         ret = 0;
1209                 }
1210                 break;
1211
1212 #ifdef TUN_DEBUG
1213         case TUNSETDEBUG:
1214                 tun->debug = arg;
1215                 break;
1216 #endif
1217         case TUNSETOFFLOAD:
1218                 ret = set_offload(tun->dev, arg);
1219                 break;
1220
1221         case TUNSETTXFILTER:
1222                 /* Can be set only for TAPs */
1223                 ret = -EINVAL;
1224                 if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
1225                         break;
1226                 ret = update_filter(&tun->txflt, (void __user *)arg);
1227                 break;
1228
1229         case SIOCGIFHWADDR:
1230                 /* Get hw addres */
1231                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
1232                 ifr.ifr_hwaddr.sa_family = tun->dev->type;
1233                 if (copy_to_user(argp, &ifr, sizeof ifr))
1234                         ret = -EFAULT;
1235                 break;
1236
1237         case SIOCSIFHWADDR:
1238                 /* Set hw address */
1239                 DBG(KERN_DEBUG "%s: set hw address: %pM\n",
1240                         tun->dev->name, ifr.ifr_hwaddr.sa_data);
1241
1242                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
1243                 break;
1244
1245         case TUNGETSNDBUF:
1246                 sndbuf = tun->socket.sk->sk_sndbuf;
1247                 if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
1248                         ret = -EFAULT;
1249                 break;
1250
1251         case TUNSETSNDBUF:
1252                 if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
1253                         ret = -EFAULT;
1254                         break;
1255                 }
1256
1257                 tun->socket.sk->sk_sndbuf = sndbuf;
1258                 break;
1259
1260         default:
1261                 ret = -EINVAL;
1262                 break;
1263         };
1264
1265 unlock:
1266         rtnl_unlock();
1267         if (tun)
1268                 tun_put(tun);
1269         return ret;
1270 }
1271
1272 static int tun_chr_fasync(int fd, struct file *file, int on)
1273 {
1274         struct tun_struct *tun = tun_get(file);
1275         int ret;
1276
1277         if (!tun)
1278                 return -EBADFD;
1279
1280         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
1281
1282         lock_kernel();
1283         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
1284                 goto out;
1285
1286         if (on) {
1287                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
1288                 if (ret)
1289                         goto out;
1290                 tun->flags |= TUN_FASYNC;
1291         } else
1292                 tun->flags &= ~TUN_FASYNC;
1293         ret = 0;
1294 out:
1295         unlock_kernel();
1296         tun_put(tun);
1297         return ret;
1298 }
1299
1300 static int tun_chr_open(struct inode *inode, struct file * file)
1301 {
1302         struct tun_file *tfile;
1303         cycle_kernel_lock();
1304         DBG1(KERN_INFO "tunX: tun_chr_open\n");
1305
1306         tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
1307         if (!tfile)
1308                 return -ENOMEM;
1309         atomic_set(&tfile->count, 0);
1310         tfile->tun = NULL;
1311         tfile->net = get_net(current->nsproxy->net_ns);
1312         file->private_data = tfile;
1313         return 0;
1314 }
1315
1316 static int tun_chr_close(struct inode *inode, struct file *file)
1317 {
1318         struct tun_file *tfile = file->private_data;
1319         struct tun_struct *tun;
1320
1321         tun = __tun_get(tfile);
1322         if (tun) {
1323                 struct net_device *dev = tun->dev;
1324
1325                 DBG(KERN_INFO "%s: tun_chr_close\n", dev->name);
1326
1327                 __tun_detach(tun);
1328
1329                 /* If desireable, unregister the netdevice. */
1330                 if (!(tun->flags & TUN_PERSIST)) {
1331                         rtnl_lock();
1332                         if (dev->reg_state == NETREG_REGISTERED)
1333                                 unregister_netdevice(dev);
1334                         rtnl_unlock();
1335                 }
1336         }
1337
1338         tun = tfile->tun;
1339         if (tun)
1340                 sock_put(tun->socket.sk);
1341
1342         put_net(tfile->net);
1343         kfree(tfile);
1344
1345         return 0;
1346 }
1347
1348 static const struct file_operations tun_fops = {
1349         .owner  = THIS_MODULE,
1350         .llseek = no_llseek,
1351         .read  = do_sync_read,
1352         .aio_read  = tun_chr_aio_read,
1353         .write = do_sync_write,
1354         .aio_write = tun_chr_aio_write,
1355         .poll   = tun_chr_poll,
1356         .unlocked_ioctl = tun_chr_ioctl,
1357         .open   = tun_chr_open,
1358         .release = tun_chr_close,
1359         .fasync = tun_chr_fasync
1360 };
1361
1362 static struct miscdevice tun_miscdev = {
1363         .minor = TUN_MINOR,
1364         .name = "tun",
1365         .devnode = "net/tun",
1366         .fops = &tun_fops,
1367 };
1368
1369 /* ethtool interface */
1370
1371 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
1372 {
1373         cmd->supported          = 0;
1374         cmd->advertising        = 0;
1375         cmd->speed              = SPEED_10;
1376         cmd->duplex             = DUPLEX_FULL;
1377         cmd->port               = PORT_TP;
1378         cmd->phy_address        = 0;
1379         cmd->transceiver        = XCVR_INTERNAL;
1380         cmd->autoneg            = AUTONEG_DISABLE;
1381         cmd->maxtxpkt           = 0;
1382         cmd->maxrxpkt           = 0;
1383         return 0;
1384 }
1385
1386 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
1387 {
1388         struct tun_struct *tun = netdev_priv(dev);
1389
1390         strcpy(info->driver, DRV_NAME);
1391         strcpy(info->version, DRV_VERSION);
1392         strcpy(info->fw_version, "N/A");
1393
1394         switch (tun->flags & TUN_TYPE_MASK) {
1395         case TUN_TUN_DEV:
1396                 strcpy(info->bus_info, "tun");
1397                 break;
1398         case TUN_TAP_DEV:
1399                 strcpy(info->bus_info, "tap");
1400                 break;
1401         }
1402 }
1403
1404 static u32 tun_get_msglevel(struct net_device *dev)
1405 {
1406 #ifdef TUN_DEBUG
1407         struct tun_struct *tun = netdev_priv(dev);
1408         return tun->debug;
1409 #else
1410         return -EOPNOTSUPP;
1411 #endif
1412 }
1413
1414 static void tun_set_msglevel(struct net_device *dev, u32 value)
1415 {
1416 #ifdef TUN_DEBUG
1417         struct tun_struct *tun = netdev_priv(dev);
1418         tun->debug = value;
1419 #endif
1420 }
1421
1422 static u32 tun_get_link(struct net_device *dev)
1423 {
1424         struct tun_struct *tun = netdev_priv(dev);
1425         return !!tun->tfile;
1426 }
1427
1428 static u32 tun_get_rx_csum(struct net_device *dev)
1429 {
1430         struct tun_struct *tun = netdev_priv(dev);
1431         return (tun->flags & TUN_NOCHECKSUM) == 0;
1432 }
1433
1434 static int tun_set_rx_csum(struct net_device *dev, u32 data)
1435 {
1436         struct tun_struct *tun = netdev_priv(dev);
1437         if (data)
1438                 tun->flags &= ~TUN_NOCHECKSUM;
1439         else
1440                 tun->flags |= TUN_NOCHECKSUM;
1441         return 0;
1442 }
1443
1444 static const struct ethtool_ops tun_ethtool_ops = {
1445         .get_settings   = tun_get_settings,
1446         .get_drvinfo    = tun_get_drvinfo,
1447         .get_msglevel   = tun_get_msglevel,
1448         .set_msglevel   = tun_set_msglevel,
1449         .get_link       = tun_get_link,
1450         .get_rx_csum    = tun_get_rx_csum,
1451         .set_rx_csum    = tun_set_rx_csum
1452 };
1453
1454
1455 static int __init tun_init(void)
1456 {
1457         int ret = 0;
1458
1459         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
1460         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
1461
1462         ret = rtnl_link_register(&tun_link_ops);
1463         if (ret) {
1464                 printk(KERN_ERR "tun: Can't register link_ops\n");
1465                 goto err_linkops;
1466         }
1467
1468         ret = misc_register(&tun_miscdev);
1469         if (ret) {
1470                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1471                 goto err_misc;
1472         }
1473         return  0;
1474 err_misc:
1475         rtnl_link_unregister(&tun_link_ops);
1476 err_linkops:
1477         return ret;
1478 }
1479
1480 static void tun_cleanup(void)
1481 {
1482         misc_deregister(&tun_miscdev);
1483         rtnl_link_unregister(&tun_link_ops);
1484 }
1485
1486 module_init(tun_init);
1487 module_exit(tun_cleanup);
1488 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1489 MODULE_AUTHOR(DRV_COPYRIGHT);
1490 MODULE_LICENSE("GPL");
1491 MODULE_ALIAS_MISCDEV(TUN_MINOR);