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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 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
 292                               unsigned long count, loff_t pos)
 293 {
 294         struct tun_struct *tun = iocb->ki_filp->private_data;
 295
 296         if (!tun)
 297                 return -EBADFD;
 298
 299         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
 300
 301         return tun_get_user(tun, (struct iovec *) iv, iov_total(iv, count));
 302 }
 303
 304 /* Put packet to the user space buffer */
 305 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
 306                                        struct sk_buff *skb,
 307                                        struct iovec *iv, int len)
 308 {
 309         struct tun_pi pi = { 0, skb->protocol };
 310         ssize_t total = 0;
 311
 312         if (!(tun->flags & TUN_NO_PI)) {
 313                 if ((len -= sizeof(pi)) < 0)
 314                         return -EINVAL;
 315
 316                 if (len < skb->len) {
 317                         /* Packet will be striped */
 318                         pi.flags |= TUN_PKT_STRIP;
 319                 }
 320
 321                 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
 322                         return -EFAULT;
 323                 total += sizeof(pi);
 324         }
 325
 326         len = min_t(int, skb->len, len);
 327
 328         skb_copy_datagram_iovec(skb, 0, iv, len);
 329         total += len;
 330
 331         tun->stats.tx_packets++;
 332         tun->stats.tx_bytes += len;
 333
 334         return total;
 335 }
 336
 337 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
 338                             unsigned long count, loff_t pos)
 339 {
 340         struct file *file = iocb->ki_filp;
 341         struct tun_struct *tun = file->private_data;
 342         DECLARE_WAITQUEUE(wait, current);
 343         struct sk_buff *skb;
 344         ssize_t len, ret = 0;
 345
 346         if (!tun)
 347                 return -EBADFD;
 348
 349         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
 350
 351         len = iov_total(iv, count);
 352         if (len < 0)
 353                 return -EINVAL;
 354
 355         add_wait_queue(&tun->read_wait, &wait);
 356         while (len) {
 357                 const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 358                 u8 addr[ ETH_ALEN];
 359                 int bit_nr;
 360
 361                 current->state = TASK_INTERRUPTIBLE;
 362
 363                 /* Read frames from the queue */
 364                 if (!(skb=skb_dequeue(&tun->readq))) {
 365                         if (file->f_flags & O_NONBLOCK) {
 366                                 ret = -EAGAIN;
 367                                 break;
 368                         }
 369                         if (signal_pending(current)) {
 370                                 ret = -ERESTARTSYS;
 371                                 break;
 372                         }
 373
 374                         /* Nothing to read, let's sleep */
 375                         schedule();
 376                         continue;
 377                 }
 378                 netif_wake_queue(tun->dev);
 379
 380                 /** Decide whether to accept this packet. This code is designed to
 381                  * behave identically to an Ethernet interface. Accept the packet if
 382                  * - we are promiscuous.
 383                  * - the packet is addressed to us.
 384                  * - the packet is broadcast.
 385                  * - the packet is multicast and
 386                  *   - we are multicast promiscous.
 387                  *   - we belong to the multicast group.
 388                  */
 389                 memcpy(addr, skb->data,
 390                        min_t(size_t, sizeof addr, skb->len));
 391                 bit_nr = ether_crc(sizeof addr, addr) >> 26;
 392                 if ((tun->if_flags & IFF_PROMISC) ||
 393                                 memcmp(addr, tun->dev_addr, sizeof addr) == 0 ||
 394                                 memcmp(addr, ones, sizeof addr) == 0 ||
 395                                 (((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) ||
 396                                   (addr[0] == 0x33 && addr[1] == 0x33)) &&
 397                                  ((tun->if_flags & IFF_ALLMULTI) ||
 398                                   (tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) {
 399                         DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %x:%x:%x:%x:%x:%x\n",
 400                                         tun->dev->name, addr[0], addr[1], addr[2],
 401                                         addr[3], addr[4], addr[5]);
 402                         ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
 403                         kfree_skb(skb);
 404                         break;
 405                 } else {
 406                         DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %x:%x:%x:%x:%x:%x\n",
 407                                         tun->dev->name, addr[0], addr[1], addr[2],
 408                                         addr[3], addr[4], addr[5]);
 409                         kfree_skb(skb);
 410                         continue;
 411                 }
 412         }
 413
 414         current->state = TASK_RUNNING;
 415         remove_wait_queue(&tun->read_wait, &wait);
 416
 417         return ret;
 418 }
 419
 420 static void tun_setup(struct net_device *dev)
 421 {
 422         struct tun_struct *tun = netdev_priv(dev);
 423
 424         skb_queue_head_init(&tun->readq);
 425         init_waitqueue_head(&tun->read_wait);
 426
 427         tun->owner = -1;
 428
 429         SET_MODULE_OWNER(dev);
 430         dev->open = tun_net_open;
 431         dev->hard_start_xmit = tun_net_xmit;
 432         dev->stop = tun_net_close;
 433         dev->get_stats = tun_net_stats;
 434         dev->ethtool_ops = &tun_ethtool_ops;
 435         dev->destructor = free_netdev;
 436 }
 437
 438 static struct tun_struct *tun_get_by_name(const char *name)
 439 {
 440         struct tun_struct *tun;
 441
 442         ASSERT_RTNL();
 443         list_for_each_entry(tun, &tun_dev_list, list) {
 444                 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
 445                     return tun;
 446         }
 447
 448         return NULL;
 449 }
 450
 451 static int tun_set_iff(struct file *file, struct ifreq *ifr)
 452 {
 453         struct tun_struct *tun;
 454         struct net_device *dev;
 455         int err;
 456
 457         tun = tun_get_by_name(ifr->ifr_name);
 458         if (tun) {
 459                 if (tun->attached)
 460                         return -EBUSY;
 461
 462                 /* Check permissions */
 463                 if (tun->owner != -1 &&
 464                     current->euid != tun->owner && !capable(CAP_NET_ADMIN))
 465                         return -EPERM;
 466         }
 467         else if (__dev_get_by_name(ifr->ifr_name))
 468                 return -EINVAL;
 469         else {
 470                 char *name;
 471                 unsigned long flags = 0;
 472
 473                 err = -EINVAL;
 474
 475                 if (!capable(CAP_NET_ADMIN))
 476                         return -EPERM;
 477
 478                 /* Set dev type */
 479                 if (ifr->ifr_flags & IFF_TUN) {
 480                         /* TUN device */
 481                         flags |= TUN_TUN_DEV;
 482                         name = "tun%d";
 483                 } else if (ifr->ifr_flags & IFF_TAP) {
 484                         /* TAP device */
 485                         flags |= TUN_TAP_DEV;
 486                         name = "tap%d";
 487                 } else
 488                         goto failed;
 489
 490                 if (*ifr->ifr_name)
 491                         name = ifr->ifr_name;
 492
 493                 dev = alloc_netdev(sizeof(struct tun_struct), name,
 494                                    tun_setup);
 495                 if (!dev)
 496                         return -ENOMEM;
 497
 498                 tun = netdev_priv(dev);
 499                 tun->dev = dev;
 500                 tun->flags = flags;
 501                 /* Be promiscuous by default to maintain previous behaviour. */
 502                 tun->if_flags = IFF_PROMISC;
 503                 /* Generate random Ethernet address. */
 504                 *(u16 *)tun->dev_addr = htons(0x00FF);
 505                 get_random_bytes(tun->dev_addr + sizeof(u16), 4);
 506                 memset(tun->chr_filter, 0, sizeof tun->chr_filter);
 507
 508                 tun_net_init(dev);
 509
 510                 if (strchr(dev->name, '%')) {
 511                         err = dev_alloc_name(dev, dev->name);
 512                         if (err < 0)
 513                                 goto err_free_dev;
 514                 }
 515
 516                 err = register_netdevice(tun->dev);
 517                 if (err < 0)
 518                         goto err_free_dev;
 519
 520                 list_add(&tun->list, &tun_dev_list);
 521         }
 522
 523         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
 524
 525         if (ifr->ifr_flags & IFF_NO_PI)
 526                 tun->flags |= TUN_NO_PI;
 527
 528         if (ifr->ifr_flags & IFF_ONE_QUEUE)
 529                 tun->flags |= TUN_ONE_QUEUE;
 530
 531         file->private_data = tun;
 532         tun->attached = 1;
 533
 534         strcpy(ifr->ifr_name, tun->dev->name);
 535         return 0;
 536
 537  err_free_dev:
 538         free_netdev(dev);
 539  failed:
 540         return err;
 541 }
 542
 543 static int tun_chr_ioctl(struct inode *inode, struct file *file,
 544                          unsigned int cmd, unsigned long arg)
 545 {
 546         struct tun_struct *tun = file->private_data;
 547         void __user* argp = (void __user*)arg;
 548         struct ifreq ifr;
 549
 550         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
 551                 if (copy_from_user(&ifr, argp, sizeof ifr))
 552                         return -EFAULT;
 553
 554         if (cmd == TUNSETIFF && !tun) {
 555                 int err;
 556
 557                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
 558
 559                 rtnl_lock();
 560                 err = tun_set_iff(file, &ifr);
 561                 rtnl_unlock();
 562
 563                 if (err)
 564                         return err;
 565
 566                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
 567                         return -EFAULT;
 568                 return 0;
 569         }
 570
 571         if (!tun)
 572                 return -EBADFD;
 573
 574         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
 575
 576         switch (cmd) {
 577         case TUNSETNOCSUM:
 578                 /* Disable/Enable checksum */
 579                 if (arg)
 580                         tun->flags |= TUN_NOCHECKSUM;
 581                 else
 582                         tun->flags &= ~TUN_NOCHECKSUM;
 583
 584                 DBG(KERN_INFO "%s: checksum %s\n",
 585                     tun->dev->name, arg ? "disabled" : "enabled");
 586                 break;
 587
 588         case TUNSETPERSIST:
 589                 /* Disable/Enable persist mode */
 590                 if (arg)
 591                         tun->flags |= TUN_PERSIST;
 592                 else
 593                         tun->flags &= ~TUN_PERSIST;
 594
 595                 DBG(KERN_INFO "%s: persist %s\n",
 596                     tun->dev->name, arg ? "disabled" : "enabled");
 597                 break;
 598
 599         case TUNSETOWNER:
 600                 /* Set owner of the device */
 601                 tun->owner = (uid_t) arg;
 602
 603                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
 604                 break;
 605
 606         case TUNSETLINK:
 607                 /* Only allow setting the type when the interface is down */
 608                 if (tun->dev->flags & IFF_UP) {
 609                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
 610                                 tun->dev->name);
 611                         return -EBUSY;
 612                 } else {
 613                         tun->dev->type = (int) arg;
 614                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
 615                 }
 616                 break;
 617
 618 #ifdef TUN_DEBUG
 619         case TUNSETDEBUG:
 620                 tun->debug = arg;
 621                 break;
 622 #endif
 623
 624         case SIOCGIFFLAGS:
 625                 ifr.ifr_flags = tun->if_flags;
 626                 if (copy_to_user( argp, &ifr, sizeof ifr))
 627                         return -EFAULT;
 628                 return 0;
 629
 630         case SIOCSIFFLAGS:
 631                 /** Set the character device's interface flags. Currently only
 632                  * IFF_PROMISC and IFF_ALLMULTI are used. */
 633                 tun->if_flags = ifr.ifr_flags;
 634                 DBG(KERN_INFO "%s: interface flags 0x%lx\n",
 635                                 tun->dev->name, tun->if_flags);
 636                 return 0;
 637
 638         case SIOCGIFHWADDR:
 639                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr,
 640                                 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
 641                 if (copy_to_user( argp, &ifr, sizeof ifr))
 642                         return -EFAULT;
 643                 return 0;
 644
 645         case SIOCSIFHWADDR:
 646                 /** Set the character device's hardware address. This is used when
 647                  * filtering packets being sent from the network device to the character
 648                  * device. */
 649                 memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data,
 650                                 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
 651                 DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n",
 652                                 tun->dev->name,
 653                                 tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2],
 654                                 tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]);
 655                 return 0;
 656
 657         case SIOCADDMULTI:
 658                 /** Add the specified group to the character device's multicast filter
 659                  * list. */
 660                 add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
 661                 DBG(KERN_DEBUG "%s: add multi: %x:%x:%x:%x:%x:%x\n",
 662                                 tun->dev->name,
 663                                 (u8)ifr.ifr_hwaddr.sa_data[0], (u8)ifr.ifr_hwaddr.sa_data[1],
 664                                 (u8)ifr.ifr_hwaddr.sa_data[2], (u8)ifr.ifr_hwaddr.sa_data[3],
 665                                 (u8)ifr.ifr_hwaddr.sa_data[4], (u8)ifr.ifr_hwaddr.sa_data[5]);
 666                 return 0;
 667
 668         case SIOCDELMULTI:
 669                 /** Remove the specified group from the character device's multicast
 670                  * filter list. */
 671                 del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
 672                 DBG(KERN_DEBUG "%s: del multi: %x:%x:%x:%x:%x:%x\n",
 673                                 tun->dev->name,
 674                                 (u8)ifr.ifr_hwaddr.sa_data[0], (u8)ifr.ifr_hwaddr.sa_data[1],
 675                                 (u8)ifr.ifr_hwaddr.sa_data[2], (u8)ifr.ifr_hwaddr.sa_data[3],
 676                                 (u8)ifr.ifr_hwaddr.sa_data[4], (u8)ifr.ifr_hwaddr.sa_data[5]);
 677                 return 0;
 678
 679         default:
 680                 return -EINVAL;
 681         };
 682
 683         return 0;
 684 }
 685
 686 static int tun_chr_fasync(int fd, struct file *file, int on)
 687 {
 688         struct tun_struct *tun = file->private_data;
 689         int ret;
 690
 691         if (!tun)
 692                 return -EBADFD;
 693
 694         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
 695
 696         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
 697                 return ret;
 698
 699         if (on) {
 700                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
 701                 if (ret)
 702                         return ret;
 703                 tun->flags |= TUN_FASYNC;
 704         } else
 705                 tun->flags &= ~TUN_FASYNC;
 706
 707         return 0;
 708 }
 709
 710 static int tun_chr_open(struct inode *inode, struct file * file)
 711 {
 712         DBG1(KERN_INFO "tunX: tun_chr_open\n");
 713         file->private_data = NULL;
 714         return 0;
 715 }
 716
 717 static int tun_chr_close(struct inode *inode, struct file *file)
 718 {
 719         struct tun_struct *tun = file->private_data;
 720
 721         if (!tun)
 722                 return 0;
 723
 724         DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
 725
 726         tun_chr_fasync(-1, file, 0);
 727
 728         rtnl_lock();
 729
 730         /* Detach from net device */
 731         file->private_data = NULL;
 732         tun->attached = 0;
 733
 734         /* Drop read queue */
 735         skb_queue_purge(&tun->readq);
 736
 737         if (!(tun->flags & TUN_PERSIST)) {
 738                 list_del(&tun->list);
 739                 unregister_netdevice(tun->dev);
 740         }
 741
 742         rtnl_unlock();
 743
 744         return 0;
 745 }
 746
 747 static const struct file_operations tun_fops = {
 748         .owner  = THIS_MODULE,
 749         .llseek = no_llseek,
 750         .read  = do_sync_read,
 751         .aio_read  = tun_chr_aio_read,
 752         .write = do_sync_write,
 753         .aio_write = tun_chr_aio_write,
 754         .poll   = tun_chr_poll,
 755         .ioctl  = tun_chr_ioctl,
 756         .open   = tun_chr_open,
 757         .release = tun_chr_close,
 758         .fasync = tun_chr_fasync
 759 };
 760
 761 static struct miscdevice tun_miscdev = {
 762         .minor = TUN_MINOR,
 763         .name = "tun",
 764         .fops = &tun_fops,
 765 };
 766
 767 /* ethtool interface */
 768
 769 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 770 {
 771         cmd->supported          = 0;
 772         cmd->advertising        = 0;
 773         cmd->speed              = SPEED_10;
 774         cmd->duplex             = DUPLEX_FULL;
 775         cmd->port               = PORT_TP;
 776         cmd->phy_address        = 0;
 777         cmd->transceiver        = XCVR_INTERNAL;
 778         cmd->autoneg            = AUTONEG_DISABLE;
 779         cmd->maxtxpkt           = 0;
 780         cmd->maxrxpkt           = 0;
 781         return 0;
 782 }
 783
 784 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 785 {
 786         struct tun_struct *tun = netdev_priv(dev);
 787
 788         strcpy(info->driver, DRV_NAME);
 789         strcpy(info->version, DRV_VERSION);
 790         strcpy(info->fw_version, "N/A");
 791
 792         switch (tun->flags & TUN_TYPE_MASK) {
 793         case TUN_TUN_DEV:
 794                 strcpy(info->bus_info, "tun");
 795                 break;
 796         case TUN_TAP_DEV:
 797                 strcpy(info->bus_info, "tap");
 798                 break;
 799         }
 800 }
 801
 802 static u32 tun_get_msglevel(struct net_device *dev)
 803 {
 804 #ifdef TUN_DEBUG
 805         struct tun_struct *tun = netdev_priv(dev);
 806         return tun->debug;
 807 #else
 808         return -EOPNOTSUPP;
 809 #endif
 810 }
 811
 812 static void tun_set_msglevel(struct net_device *dev, u32 value)
 813 {
 814 #ifdef TUN_DEBUG
 815         struct tun_struct *tun = netdev_priv(dev);
 816         tun->debug = value;
 817 #endif
 818 }
 819
 820 static u32 tun_get_link(struct net_device *dev)
 821 {
 822         struct tun_struct *tun = netdev_priv(dev);
 823         return tun->attached;
 824 }
 825
 826 static u32 tun_get_rx_csum(struct net_device *dev)
 827 {
 828         struct tun_struct *tun = netdev_priv(dev);
 829         return (tun->flags & TUN_NOCHECKSUM) == 0;
 830 }
 831
 832 static int tun_set_rx_csum(struct net_device *dev, u32 data)
 833 {
 834         struct tun_struct *tun = netdev_priv(dev);
 835         if (data)
 836                 tun->flags &= ~TUN_NOCHECKSUM;
 837         else
 838                 tun->flags |= TUN_NOCHECKSUM;
 839         return 0;
 840 }
 841
 842 static const struct ethtool_ops tun_ethtool_ops = {
 843         .get_settings   = tun_get_settings,
 844         .get_drvinfo    = tun_get_drvinfo,
 845         .get_msglevel   = tun_get_msglevel,
 846         .set_msglevel   = tun_set_msglevel,
 847         .get_link       = tun_get_link,
 848         .get_rx_csum    = tun_get_rx_csum,
 849         .set_rx_csum    = tun_set_rx_csum
 850 };
 851
 852 static int __init tun_init(void)
 853 {
 854         int ret = 0;
 855
 856         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
 857         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
 858
 859         ret = misc_register(&tun_miscdev);
 860         if (ret)
 861                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
 862         return ret;
 863 }
 864
 865 static void tun_cleanup(void)
 866 {
 867         struct tun_struct *tun, *nxt;
 868
 869         misc_deregister(&tun_miscdev);
 870
 871         rtnl_lock();
 872         list_for_each_entry_safe(tun, nxt, &tun_dev_list, list) {
 873                 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
 874                 unregister_netdevice(tun->dev);
 875         }
 876         rtnl_unlock();
 877
 878 }
 879
 880 module_init(tun_init);
 881 module_exit(tun_cleanup);
 882 MODULE_DESCRIPTION(DRV_DESCRIPTION);
 883 MODULE_AUTHOR(DRV_COPYRIGHT);
 884 MODULE_LICENSE("GPL");
 885 MODULE_ALIAS_MISCDEV(TUN_MINOR);