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   1 /*
   2  *  TUN - Universal TUN/TAP device driver.
   3  *  Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
  16  */
  17
  18 /*
  19  *  Changes:
  20  *
  21  *  Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
  22  *    Add TUNSETLINK ioctl to set the link encapsulation
  23  *
  24  *  Mark Smith <markzzzsmith@yahoo.com.au>
  25  *   Use random_ether_addr() for tap MAC address.
  26  *
  27  *  Harald Roelle <harald.roelle@ifi.lmu.de>  2004/04/20
  28  *    Fixes in packet dropping, queue length setting and queue wakeup.
  29  *    Increased default tx queue length.
  30  *    Added ethtool API.
  31  *    Minor cleanups
  32  *
  33  *  Daniel Podlejski <underley@underley.eu.org>
  34  *    Modifications for 2.3.99-pre5 kernel.
  35  */
  36
  37 #define DRV_NAME        "tun"
  38 #define DRV_VERSION     "1.6"
  39 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
  40 #define DRV_COPYRIGHT   "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
  41
  42 #include <linux/module.h>
  43 #include <linux/errno.h>
  44 #include <linux/kernel.h>
  45 #include <linux/major.h>
  46 #include <linux/slab.h>
  47 #include <linux/poll.h>
  48 #include <linux/fcntl.h>
  49 #include <linux/init.h>
  50 #include <linux/skbuff.h>
  51 #include <linux/netdevice.h>
  52 #include <linux/etherdevice.h>
  53 #include <linux/miscdevice.h>
  54 #include <linux/ethtool.h>
  55 #include <linux/rtnetlink.h>
  56 #include <linux/if.h>
  57 #include <linux/if_arp.h>
  58 #include <linux/if_ether.h>
  59 #include <linux/if_tun.h>
  60 #include <linux/crc32.h>
  61
  62 #include <asm/system.h>
  63 #include <asm/uaccess.h>
  64
  65 #ifdef TUN_DEBUG
  66 static int debug;
  67 #endif
  68
  69 /* Network device part of the driver */
  70
  71 static LIST_HEAD(tun_dev_list);
  72 static const struct ethtool_ops tun_ethtool_ops;
  73
  74 /* Net device open. */
  75 static int tun_net_open(struct net_device *dev)
  76 {
  77         netif_start_queue(dev);
  78         return 0;
  79 }
  80
  81 /* Net device close. */
  82 static int tun_net_close(struct net_device *dev)
  83 {
  84         netif_stop_queue(dev);
  85         return 0;
  86 }
  87
  88 /* Net device start xmit */
  89 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
  90 {
  91         struct tun_struct *tun = netdev_priv(dev);
  92
  93         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
  94
  95         /* Drop packet if interface is not attached */
  96         if (!tun->attached)
  97                 goto drop;
  98
  99         /* Packet dropping */
 100         if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
 101                 if (!(tun->flags & TUN_ONE_QUEUE)) {
 102                         /* Normal queueing mode. */
 103                         /* Packet scheduler handles dropping of further packets. */
 104                         netif_stop_queue(dev);
 105
 106                         /* We won't see all dropped packets individually, so overrun
 107                          * error is more appropriate. */
 108                         tun->stats.tx_fifo_errors++;
 109                 } else {
 110                         /* Single queue mode.
 111                          * Driver handles dropping of all packets itself. */
 112                         goto drop;
 113                 }
 114         }
 115
 116         /* Queue packet */
 117         skb_queue_tail(&tun->readq, skb);
 118         dev->trans_start = jiffies;
 119
 120         /* Notify and wake up reader process */
 121         if (tun->flags & TUN_FASYNC)
 122                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
 123         wake_up_interruptible(&tun->read_wait);
 124         return 0;
 125
 126 drop:
 127         tun->stats.tx_dropped++;
 128         kfree_skb(skb);
 129         return 0;
 130 }
 131
 132 /** Add the specified Ethernet address to this multicast filter. */
 133 static void
 134 add_multi(u32* filter, const u8* addr)
 135 {
 136         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
 137         filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
 138 }
 139
 140 /** Remove the specified Ethernet addres from this multicast filter. */
 141 static void
 142 del_multi(u32* filter, const u8* addr)
 143 {
 144         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
 145         filter[bit_nr >> 5] &= ~(1 << (bit_nr & 31));
 146 }
 147
 148 /** Update the list of multicast groups to which the network device belongs.
 149  * This list is used to filter packets being sent from the character device to
 150  * the network device. */
 151 static void
 152 tun_net_mclist(struct net_device *dev)
 153 {
 154         struct tun_struct *tun = netdev_priv(dev);
 155         const struct dev_mc_list *mclist;
 156         int i;
 157         DBG(KERN_DEBUG "%s: tun_net_mclist: mc_count %d\n",
 158                         dev->name, dev->mc_count);
 159         memset(tun->chr_filter, 0, sizeof tun->chr_filter);
 160         for (i = 0, mclist = dev->mc_list; i < dev->mc_count && mclist != NULL;
 161                         i++, mclist = mclist->next) {
 162                 add_multi(tun->net_filter, mclist->dmi_addr);
 163                 DBG(KERN_DEBUG "%s: tun_net_mclist: %x:%x:%x:%x:%x:%x\n",
 164                                 dev->name,
 165                                 mclist->dmi_addr[0], mclist->dmi_addr[1], mclist->dmi_addr[2],
 166                                 mclist->dmi_addr[3], mclist->dmi_addr[4], mclist->dmi_addr[5]);
 167         }
 168 }
 169
 170 static struct net_device_stats *tun_net_stats(struct net_device *dev)
 171 {
 172         struct tun_struct *tun = netdev_priv(dev);
 173         return &tun->stats;
 174 }
 175
 176 /* Initialize net device. */
 177 static void tun_net_init(struct net_device *dev)
 178 {
 179         struct tun_struct *tun = netdev_priv(dev);
 180
 181         switch (tun->flags & TUN_TYPE_MASK) {
 182         case TUN_TUN_DEV:
 183                 /* Point-to-Point TUN Device */
 184                 dev->hard_header_len = 0;
 185                 dev->addr_len = 0;
 186                 dev->mtu = 1500;
 187
 188                 /* Zero header length */
 189                 dev->type = ARPHRD_NONE;
 190                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 191                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 192                 break;
 193
 194         case TUN_TAP_DEV:
 195                 /* Ethernet TAP Device */
 196                 dev->set_multicast_list = tun_net_mclist;
 197
 198                 ether_setup(dev);
 199                 random_ether_addr(dev->dev_addr);
 200                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 201                 break;
 202         }
 203 }
 204
 205 /* Character device part */
 206
 207 /* Poll */
 208 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
 209 {
 210         struct tun_struct *tun = file->private_data;
 211         unsigned int mask = POLLOUT | POLLWRNORM;
 212
 213         if (!tun)
 214                 return -EBADFD;
 215
 216         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
 217
 218         poll_wait(file, &tun->read_wait, wait);
 219
 220         if (!skb_queue_empty(&tun->readq))
 221                 mask |= POLLIN | POLLRDNORM;
 222
 223         return mask;
 224 }
 225
 226 /* Get packet from user space buffer */
 227 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
 228 {
 229         struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
 230         struct sk_buff *skb;
 231         size_t len = count, align = 0;
 232
 233         if (!(tun->flags & TUN_NO_PI)) {
 234                 if ((len -= sizeof(pi)) > count)
 235                         return -EINVAL;
 236
 237                 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
 238                         return -EFAULT;
 239         }
 240
 241         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV)
 242                 align = NET_IP_ALIGN;
 243
 244         if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
 245                 tun->stats.rx_dropped++;
 246                 return -ENOMEM;
 247         }
 248
 249         if (align)
 250                 skb_reserve(skb, align);
 251         if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
 252                 tun->stats.rx_dropped++;
 253                 kfree_skb(skb);
 254                 return -EFAULT;
 255         }
 256
 257         skb->dev = tun->dev;
 258         switch (tun->flags & TUN_TYPE_MASK) {
 259         case TUN_TUN_DEV:
 260                 skb->mac.raw = skb->data;
 261                 skb->protocol = pi.proto;
 262                 break;
 263         case TUN_TAP_DEV:
 264                 skb->protocol = eth_type_trans(skb, tun->dev);
 265                 break;
 266         };
 267
 268         if (tun->flags & TUN_NOCHECKSUM)
 269                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 270
 271         netif_rx_ni(skb);
 272         tun->dev->last_rx = jiffies;
 273
 274         tun->stats.rx_packets++;
 275         tun->stats.rx_bytes += len;
 276
 277         return count;
 278 }
 279
 280 static inline size_t iov_total(const struct iovec *iv, unsigned long count)
 281 {
 282         unsigned long i;
 283         size_t len;
 284
 285         for (i = 0, len = 0; i < count; i++)
 286                 len += iv[i].iov_len;
 287
 288         return len;
 289 }
 290
 291 /* Writev */
 292 static ssize_t tun_chr_writev(struct file * file, const struct iovec *iv,
 293                               unsigned long count, loff_t *pos)
 294 {
 295         struct tun_struct *tun = file->private_data;
 296
 297         if (!tun)
 298                 return -EBADFD;
 299
 300         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
 301
 302         return tun_get_user(tun, (struct iovec *) iv, iov_total(iv, count));
 303 }
 304
 305 /* Write */
 306 static ssize_t tun_chr_write(struct file * file, const char __user * buf,
 307                              size_t count, loff_t *pos)
 308 {
 309         struct iovec iv = { (void __user *) buf, count };
 310         return tun_chr_writev(file, &iv, 1, pos);
 311 }
 312
 313 /* Put packet to the user space buffer */
 314 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
 315                                        struct sk_buff *skb,
 316                                        struct iovec *iv, int len)
 317 {
 318         struct tun_pi pi = { 0, skb->protocol };
 319         ssize_t total = 0;
 320
 321         if (!(tun->flags & TUN_NO_PI)) {
 322                 if ((len -= sizeof(pi)) < 0)
 323                         return -EINVAL;
 324
 325                 if (len < skb->len) {
 326                         /* Packet will be striped */
 327                         pi.flags |= TUN_PKT_STRIP;
 328                 }
 329
 330                 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
 331                         return -EFAULT;
 332                 total += sizeof(pi);
 333         }
 334
 335         len = min_t(int, skb->len, len);
 336
 337         skb_copy_datagram_iovec(skb, 0, iv, len);
 338         total += len;
 339
 340         tun->stats.tx_packets++;
 341         tun->stats.tx_bytes += len;
 342
 343         return total;
 344 }
 345
 346 /* Readv */
 347 static ssize_t tun_chr_readv(struct file *file, const struct iovec *iv,
 348                             unsigned long count, loff_t *pos)
 349 {
 350         struct tun_struct *tun = file->private_data;
 351         DECLARE_WAITQUEUE(wait, current);
 352         struct sk_buff *skb;
 353         ssize_t len, ret = 0;
 354
 355         if (!tun)
 356                 return -EBADFD;
 357
 358         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
 359
 360         len = iov_total(iv, count);
 361         if (len < 0)
 362                 return -EINVAL;
 363
 364         add_wait_queue(&tun->read_wait, &wait);
 365         while (len) {
 366                 const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 367                 u8 addr[ ETH_ALEN];
 368                 int bit_nr;
 369
 370                 current->state = TASK_INTERRUPTIBLE;
 371
 372                 /* Read frames from the queue */
 373                 if (!(skb=skb_dequeue(&tun->readq))) {
 374                         if (file->f_flags & O_NONBLOCK) {
 375                                 ret = -EAGAIN;
 376                                 break;
 377                         }
 378                         if (signal_pending(current)) {
 379                                 ret = -ERESTARTSYS;
 380                                 break;
 381                         }
 382
 383                         /* Nothing to read, let's sleep */
 384                         schedule();
 385                         continue;
 386                 }
 387                 netif_wake_queue(tun->dev);
 388
 389                 /** Decide whether to accept this packet. This code is designed to
 390                  * behave identically to an Ethernet interface. Accept the packet if
 391                  * - we are promiscuous.
 392                  * - the packet is addressed to us.
 393                  * - the packet is broadcast.
 394                  * - the packet is multicast and
 395                  *   - we are multicast promiscous.
 396                  *   - we belong to the multicast group.
 397                  */
 398                 memcpy(addr, skb->data,
 399                        min_t(size_t, sizeof addr, skb->len));
 400                 bit_nr = ether_crc(sizeof addr, addr) >> 26;
 401                 if ((tun->if_flags & IFF_PROMISC) ||
 402                                 memcmp(addr, tun->dev_addr, sizeof addr) == 0 ||
 403                                 memcmp(addr, ones, sizeof addr) == 0 ||
 404                                 (((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) ||
 405                                   (addr[0] == 0x33 && addr[1] == 0x33)) &&
 406                                  ((tun->if_flags & IFF_ALLMULTI) ||
 407                                   (tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) {
 408                         DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %x:%x:%x:%x:%x:%x\n",
 409                                         tun->dev->name, addr[0], addr[1], addr[2],
 410                                         addr[3], addr[4], addr[5]);
 411                         ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
 412                         kfree_skb(skb);
 413                         break;
 414                 } else {
 415                         DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %x:%x:%x:%x:%x:%x\n",
 416                                         tun->dev->name, addr[0], addr[1], addr[2],
 417                                         addr[3], addr[4], addr[5]);
 418                         kfree_skb(skb);
 419                         continue;
 420                 }
 421         }
 422
 423         current->state = TASK_RUNNING;
 424         remove_wait_queue(&tun->read_wait, &wait);
 425
 426         return ret;
 427 }
 428
 429 /* Read */
 430 static ssize_t tun_chr_read(struct file * file, char __user * buf,
 431                             size_t count, loff_t *pos)
 432 {
 433         struct iovec iv = { buf, count };
 434         return tun_chr_readv(file, &iv, 1, pos);
 435 }
 436
 437 static void tun_setup(struct net_device *dev)
 438 {
 439         struct tun_struct *tun = netdev_priv(dev);
 440
 441         skb_queue_head_init(&tun->readq);
 442         init_waitqueue_head(&tun->read_wait);
 443
 444         tun->owner = -1;
 445
 446         SET_MODULE_OWNER(dev);
 447         dev->open = tun_net_open;
 448         dev->hard_start_xmit = tun_net_xmit;
 449         dev->stop = tun_net_close;
 450         dev->get_stats = tun_net_stats;
 451         dev->ethtool_ops = &tun_ethtool_ops;
 452         dev->destructor = free_netdev;
 453 }
 454
 455 static struct tun_struct *tun_get_by_name(const char *name)
 456 {
 457         struct tun_struct *tun;
 458
 459         ASSERT_RTNL();
 460         list_for_each_entry(tun, &tun_dev_list, list) {
 461                 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
 462                     return tun;
 463         }
 464
 465         return NULL;
 466 }
 467
 468 static int tun_set_iff(struct file *file, struct ifreq *ifr)
 469 {
 470         struct tun_struct *tun;
 471         struct net_device *dev;
 472         int err;
 473
 474         tun = tun_get_by_name(ifr->ifr_name);
 475         if (tun) {
 476                 if (tun->attached)
 477                         return -EBUSY;
 478
 479                 /* Check permissions */
 480                 if (tun->owner != -1 &&
 481                     current->euid != tun->owner && !capable(CAP_NET_ADMIN))
 482                         return -EPERM;
 483         }
 484         else if (__dev_get_by_name(ifr->ifr_name))
 485                 return -EINVAL;
 486         else {
 487                 char *name;
 488                 unsigned long flags = 0;
 489
 490                 err = -EINVAL;
 491
 492                 if (!capable(CAP_NET_ADMIN))
 493                         return -EPERM;
 494
 495                 /* Set dev type */
 496                 if (ifr->ifr_flags & IFF_TUN) {
 497                         /* TUN device */
 498                         flags |= TUN_TUN_DEV;
 499                         name = "tun%d";
 500                 } else if (ifr->ifr_flags & IFF_TAP) {
 501                         /* TAP device */
 502                         flags |= TUN_TAP_DEV;
 503                         name = "tap%d";
 504                 } else
 505                         goto failed;
 506
 507                 if (*ifr->ifr_name)
 508                         name = ifr->ifr_name;
 509
 510                 dev = alloc_netdev(sizeof(struct tun_struct), name,
 511                                    tun_setup);
 512                 if (!dev)
 513                         return -ENOMEM;
 514
 515                 tun = netdev_priv(dev);
 516                 tun->dev = dev;
 517                 tun->flags = flags;
 518                 /* Be promiscuous by default to maintain previous behaviour. */
 519                 tun->if_flags = IFF_PROMISC;
 520                 /* Generate random Ethernet address. */
 521                 *(u16 *)tun->dev_addr = htons(0x00FF);
 522                 get_random_bytes(tun->dev_addr + sizeof(u16), 4);
 523                 memset(tun->chr_filter, 0, sizeof tun->chr_filter);
 524
 525                 tun_net_init(dev);
 526
 527                 if (strchr(dev->name, '%')) {
 528                         err = dev_alloc_name(dev, dev->name);
 529                         if (err < 0)
 530                                 goto err_free_dev;
 531                 }
 532
 533                 err = register_netdevice(tun->dev);
 534                 if (err < 0)
 535                         goto err_free_dev;
 536
 537                 list_add(&tun->list, &tun_dev_list);
 538         }
 539
 540         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
 541
 542         if (ifr->ifr_flags & IFF_NO_PI)
 543                 tun->flags |= TUN_NO_PI;
 544
 545         if (ifr->ifr_flags & IFF_ONE_QUEUE)
 546                 tun->flags |= TUN_ONE_QUEUE;
 547
 548         file->private_data = tun;
 549         tun->attached = 1;
 550
 551         strcpy(ifr->ifr_name, tun->dev->name);
 552         return 0;
 553
 554  err_free_dev:
 555         free_netdev(dev);
 556  failed:
 557         return err;
 558 }
 559
 560 static int tun_chr_ioctl(struct inode *inode, struct file *file,
 561                          unsigned int cmd, unsigned long arg)
 562 {
 563         struct tun_struct *tun = file->private_data;
 564         void __user* argp = (void __user*)arg;
 565         struct ifreq ifr;
 566
 567         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
 568                 if (copy_from_user(&ifr, argp, sizeof ifr))
 569                         return -EFAULT;
 570
 571         if (cmd == TUNSETIFF && !tun) {
 572                 int err;
 573
 574                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
 575
 576                 rtnl_lock();
 577                 err = tun_set_iff(file, &ifr);
 578                 rtnl_unlock();
 579
 580                 if (err)
 581                         return err;
 582
 583                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
 584                         return -EFAULT;
 585                 return 0;
 586         }
 587
 588         if (!tun)
 589                 return -EBADFD;
 590
 591         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
 592
 593         switch (cmd) {
 594         case TUNSETNOCSUM:
 595                 /* Disable/Enable checksum */
 596                 if (arg)
 597                         tun->flags |= TUN_NOCHECKSUM;
 598                 else
 599                         tun->flags &= ~TUN_NOCHECKSUM;
 600
 601                 DBG(KERN_INFO "%s: checksum %s\n",
 602                     tun->dev->name, arg ? "disabled" : "enabled");
 603                 break;
 604
 605         case TUNSETPERSIST:
 606                 /* Disable/Enable persist mode */
 607                 if (arg)
 608                         tun->flags |= TUN_PERSIST;
 609                 else
 610                         tun->flags &= ~TUN_PERSIST;
 611
 612                 DBG(KERN_INFO "%s: persist %s\n",
 613                     tun->dev->name, arg ? "disabled" : "enabled");
 614                 break;
 615
 616         case TUNSETOWNER:
 617                 /* Set owner of the device */
 618                 tun->owner = (uid_t) arg;
 619
 620                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
 621                 break;
 622
 623         case TUNSETLINK:
 624                 /* Only allow setting the type when the interface is down */
 625                 if (tun->dev->flags & IFF_UP) {
 626                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
 627                                 tun->dev->name);
 628                         return -EBUSY;
 629                 } else {
 630                         tun->dev->type = (int) arg;
 631                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
 632                 }
 633                 break;
 634
 635 #ifdef TUN_DEBUG
 636         case TUNSETDEBUG:
 637                 tun->debug = arg;
 638                 break;
 639 #endif
 640
 641         case SIOCGIFFLAGS:
 642                 ifr.ifr_flags = tun->if_flags;
 643                 if (copy_to_user( argp, &ifr, sizeof ifr))
 644                         return -EFAULT;
 645                 return 0;
 646
 647         case SIOCSIFFLAGS:
 648                 /** Set the character device's interface flags. Currently only
 649                  * IFF_PROMISC and IFF_ALLMULTI are used. */
 650                 tun->if_flags = ifr.ifr_flags;
 651                 DBG(KERN_INFO "%s: interface flags 0x%lx\n",
 652                                 tun->dev->name, tun->if_flags);
 653                 return 0;
 654
 655         case SIOCGIFHWADDR:
 656                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr,
 657                                 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
 658                 if (copy_to_user( argp, &ifr, sizeof ifr))
 659                         return -EFAULT;
 660                 return 0;
 661
 662         case SIOCSIFHWADDR:
 663                 /** Set the character device's hardware address. This is used when
 664                  * filtering packets being sent from the network device to the character
 665                  * device. */
 666                 memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data,
 667                                 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
 668                 DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n",
 669                                 tun->dev->name,
 670                                 tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2],
 671                                 tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]);
 672                 return 0;
 673
 674         case SIOCADDMULTI:
 675                 /** Add the specified group to the character device's multicast filter
 676                  * list. */
 677                 add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
 678                 DBG(KERN_DEBUG "%s: add multi: %x:%x:%x:%x:%x:%x\n",
 679                                 tun->dev->name,
 680                                 (u8)ifr.ifr_hwaddr.sa_data[0], (u8)ifr.ifr_hwaddr.sa_data[1],
 681                                 (u8)ifr.ifr_hwaddr.sa_data[2], (u8)ifr.ifr_hwaddr.sa_data[3],
 682                                 (u8)ifr.ifr_hwaddr.sa_data[4], (u8)ifr.ifr_hwaddr.sa_data[5]);
 683                 return 0;
 684
 685         case SIOCDELMULTI:
 686                 /** Remove the specified group from the character device's multicast
 687                  * filter list. */
 688                 del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
 689                 DBG(KERN_DEBUG "%s: del multi: %x:%x:%x:%x:%x:%x\n",
 690                                 tun->dev->name,
 691                                 (u8)ifr.ifr_hwaddr.sa_data[0], (u8)ifr.ifr_hwaddr.sa_data[1],
 692                                 (u8)ifr.ifr_hwaddr.sa_data[2], (u8)ifr.ifr_hwaddr.sa_data[3],
 693                                 (u8)ifr.ifr_hwaddr.sa_data[4], (u8)ifr.ifr_hwaddr.sa_data[5]);
 694                 return 0;
 695
 696         default:
 697                 return -EINVAL;
 698         };
 699
 700         return 0;
 701 }
 702
 703 static int tun_chr_fasync(int fd, struct file *file, int on)
 704 {
 705         struct tun_struct *tun = file->private_data;
 706         int ret;
 707
 708         if (!tun)
 709                 return -EBADFD;
 710
 711         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
 712
 713         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
 714                 return ret;
 715
 716         if (on) {
 717                 ret = f_setown(file, current->pid, 0);
 718                 if (ret)
 719                         return ret;
 720                 tun->flags |= TUN_FASYNC;
 721         } else
 722                 tun->flags &= ~TUN_FASYNC;
 723
 724         return 0;
 725 }
 726
 727 static int tun_chr_open(struct inode *inode, struct file * file)
 728 {
 729         DBG1(KERN_INFO "tunX: tun_chr_open\n");
 730         file->private_data = NULL;
 731         return 0;
 732 }
 733
 734 static int tun_chr_close(struct inode *inode, struct file *file)
 735 {
 736         struct tun_struct *tun = file->private_data;
 737
 738         if (!tun)
 739                 return 0;
 740
 741         DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
 742
 743         tun_chr_fasync(-1, file, 0);
 744
 745         rtnl_lock();
 746
 747         /* Detach from net device */
 748         file->private_data = NULL;
 749         tun->attached = 0;
 750
 751         /* Drop read queue */
 752         skb_queue_purge(&tun->readq);
 753
 754         if (!(tun->flags & TUN_PERSIST)) {
 755                 list_del(&tun->list);
 756                 unregister_netdevice(tun->dev);
 757         }
 758
 759         rtnl_unlock();
 760
 761         return 0;
 762 }
 763
 764 static struct file_operations tun_fops = {
 765         .owner  = THIS_MODULE,
 766         .llseek = no_llseek,
 767         .read   = tun_chr_read,
 768         .readv  = tun_chr_readv,
 769         .write  = tun_chr_write,
 770         .writev = tun_chr_writev,
 771         .poll   = tun_chr_poll,
 772         .ioctl  = tun_chr_ioctl,
 773         .open   = tun_chr_open,
 774         .release = tun_chr_close,
 775         .fasync = tun_chr_fasync
 776 };
 777
 778 static struct miscdevice tun_miscdev = {
 779         .minor = TUN_MINOR,
 780         .name = "tun",
 781         .fops = &tun_fops,
 782 };
 783
 784 /* ethtool interface */
 785
 786 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 787 {
 788         cmd->supported          = 0;
 789         cmd->advertising        = 0;
 790         cmd->speed              = SPEED_10;
 791         cmd->duplex             = DUPLEX_FULL;
 792         cmd->port               = PORT_TP;
 793         cmd->phy_address        = 0;
 794         cmd->transceiver        = XCVR_INTERNAL;
 795         cmd->autoneg            = AUTONEG_DISABLE;
 796         cmd->maxtxpkt           = 0;
 797         cmd->maxrxpkt           = 0;
 798         return 0;
 799 }
 800
 801 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 802 {
 803         struct tun_struct *tun = netdev_priv(dev);
 804
 805         strcpy(info->driver, DRV_NAME);
 806         strcpy(info->version, DRV_VERSION);
 807         strcpy(info->fw_version, "N/A");
 808
 809         switch (tun->flags & TUN_TYPE_MASK) {
 810         case TUN_TUN_DEV:
 811                 strcpy(info->bus_info, "tun");
 812                 break;
 813         case TUN_TAP_DEV:
 814                 strcpy(info->bus_info, "tap");
 815                 break;
 816         }
 817 }
 818
 819 static u32 tun_get_msglevel(struct net_device *dev)
 820 {
 821 #ifdef TUN_DEBUG
 822         struct tun_struct *tun = netdev_priv(dev);
 823         return tun->debug;
 824 #else
 825         return -EOPNOTSUPP;
 826 #endif
 827 }
 828
 829 static void tun_set_msglevel(struct net_device *dev, u32 value)
 830 {
 831 #ifdef TUN_DEBUG
 832         struct tun_struct *tun = netdev_priv(dev);
 833         tun->debug = value;
 834 #endif
 835 }
 836
 837 static u32 tun_get_link(struct net_device *dev)
 838 {
 839         struct tun_struct *tun = netdev_priv(dev);
 840         return tun->attached;
 841 }
 842
 843 static u32 tun_get_rx_csum(struct net_device *dev)
 844 {
 845         struct tun_struct *tun = netdev_priv(dev);
 846         return (tun->flags & TUN_NOCHECKSUM) == 0;
 847 }
 848
 849 static int tun_set_rx_csum(struct net_device *dev, u32 data)
 850 {
 851         struct tun_struct *tun = netdev_priv(dev);
 852         if (data)
 853                 tun->flags &= ~TUN_NOCHECKSUM;
 854         else
 855                 tun->flags |= TUN_NOCHECKSUM;
 856         return 0;
 857 }
 858
 859 static const struct ethtool_ops tun_ethtool_ops = {
 860         .get_settings   = tun_get_settings,
 861         .get_drvinfo    = tun_get_drvinfo,
 862         .get_msglevel   = tun_get_msglevel,
 863         .set_msglevel   = tun_set_msglevel,
 864         .get_link       = tun_get_link,
 865         .get_rx_csum    = tun_get_rx_csum,
 866         .set_rx_csum    = tun_set_rx_csum
 867 };
 868
 869 static int __init tun_init(void)
 870 {
 871         int ret = 0;
 872
 873         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
 874         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
 875
 876         ret = misc_register(&tun_miscdev);
 877         if (ret)
 878                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
 879         return ret;
 880 }
 881
 882 static void tun_cleanup(void)
 883 {
 884         struct tun_struct *tun, *nxt;
 885
 886         misc_deregister(&tun_miscdev);
 887
 888         rtnl_lock();
 889         list_for_each_entry_safe(tun, nxt, &tun_dev_list, list) {
 890                 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
 891                 unregister_netdevice(tun->dev);
 892         }
 893         rtnl_unlock();
 894
 895 }
 896
 897 module_init(tun_init);
 898 module_exit(tun_cleanup);
 899 MODULE_DESCRIPTION(DRV_DESCRIPTION);
 900 MODULE_AUTHOR(DRV_COPYRIGHT);
 901 MODULE_LICENSE("GPL");
 902 MODULE_ALIAS_MISCDEV(TUN_MINOR);