drivers/net/tun.c

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