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