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  *  Brian Braunstein <linuxkernel@bristyle.com> 2007/03/23
  22  *    Fixed hw address handling.  Now net_device.dev_addr is kept consistent
  23  *    with tun.dev_addr when the address is set by this module.
  24  *
  25  *  Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
  26  *    Add TUNSETLINK ioctl to set the link encapsulation
  27  *
  28  *  Mark Smith <markzzzsmith@yahoo.com.au>
  29  *   Use random_ether_addr() for tap MAC address.
  30  *
  31  *  Harald Roelle <harald.roelle@ifi.lmu.de>  2004/04/20
  32  *    Fixes in packet dropping, queue length setting and queue wakeup.
  33  *    Increased default tx queue length.
  34  *    Added ethtool API.
  35  *    Minor cleanups
  36  *
  37  *  Daniel Podlejski <underley@underley.eu.org>
  38  *    Modifications for 2.3.99-pre5 kernel.
  39  */
  40
  41 #define DRV_NAME        "tun"
  42 #define DRV_VERSION     "1.6"
  43 #define DRV_DESCRIPTION "Universal TUN/TAP device driver"
  44 #define DRV_COPYRIGHT   "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
  45
  46 #include <linux/module.h>
  47 #include <linux/errno.h>
  48 #include <linux/kernel.h>
  49 #include <linux/major.h>
  50 #include <linux/slab.h>
  51 #include <linux/poll.h>
  52 #include <linux/fcntl.h>
  53 #include <linux/init.h>
  54 #include <linux/skbuff.h>
  55 #include <linux/netdevice.h>
  56 #include <linux/etherdevice.h>
  57 #include <linux/miscdevice.h>
  58 #include <linux/ethtool.h>
  59 #include <linux/rtnetlink.h>
  60 #include <linux/if.h>
  61 #include <linux/if_arp.h>
  62 #include <linux/if_ether.h>
  63 #include <linux/if_tun.h>
  64 #include <linux/crc32.h>
  65 #include <net/net_namespace.h>
  66
  67 #include <asm/system.h>
  68 #include <asm/uaccess.h>
  69
  70 #ifdef TUN_DEBUG
  71 static int debug;
  72 #endif
  73
  74 /* Network device part of the driver */
  75
  76 static LIST_HEAD(tun_dev_list);
  77 static const struct ethtool_ops tun_ethtool_ops;
  78
  79 /* Net device open. */
  80 static int tun_net_open(struct net_device *dev)
  81 {
  82         netif_start_queue(dev);
  83         return 0;
  84 }
  85
  86 /* Net device close. */
  87 static int tun_net_close(struct net_device *dev)
  88 {
  89         netif_stop_queue(dev);
  90         return 0;
  91 }
  92
  93 /* Net device start xmit */
  94 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
  95 {
  96         struct tun_struct *tun = netdev_priv(dev);
  97
  98         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
  99
 100         /* Drop packet if interface is not attached */
 101         if (!tun->attached)
 102                 goto drop;
 103
 104         /* Packet dropping */
 105         if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
 106                 if (!(tun->flags & TUN_ONE_QUEUE)) {
 107                         /* Normal queueing mode. */
 108                         /* Packet scheduler handles dropping of further packets. */
 109                         netif_stop_queue(dev);
 110
 111                         /* We won't see all dropped packets individually, so overrun
 112                          * error is more appropriate. */
 113                         dev->stats.tx_fifo_errors++;
 114                 } else {
 115                         /* Single queue mode.
 116                          * Driver handles dropping of all packets itself. */
 117                         goto drop;
 118                 }
 119         }
 120
 121         /* Queue packet */
 122         skb_queue_tail(&tun->readq, skb);
 123         dev->trans_start = jiffies;
 124
 125         /* Notify and wake up reader process */
 126         if (tun->flags & TUN_FASYNC)
 127                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
 128         wake_up_interruptible(&tun->read_wait);
 129         return 0;
 130
 131 drop:
 132         dev->stats.tx_dropped++;
 133         kfree_skb(skb);
 134         return 0;
 135 }
 136
 137 /** Add the specified Ethernet address to this multicast filter. */
 138 static void
 139 add_multi(u32* filter, const u8* addr)
 140 {
 141         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
 142         filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
 143 }
 144
 145 /** Remove the specified Ethernet addres from this multicast filter. */
 146 static void
 147 del_multi(u32* filter, const u8* addr)
 148 {
 149         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
 150         filter[bit_nr >> 5] &= ~(1 << (bit_nr & 31));
 151 }
 152
 153 /** Update the list of multicast groups to which the network device belongs.
 154  * This list is used to filter packets being sent from the character device to
 155  * the network device. */
 156 static void
 157 tun_net_mclist(struct net_device *dev)
 158 {
 159         struct tun_struct *tun = netdev_priv(dev);
 160         const struct dev_mc_list *mclist;
 161         int i;
 162         DBG(KERN_DEBUG "%s: tun_net_mclist: mc_count %d\n",
 163                         dev->name, dev->mc_count);
 164         memset(tun->chr_filter, 0, sizeof tun->chr_filter);
 165         for (i = 0, mclist = dev->mc_list; i < dev->mc_count && mclist != NULL;
 166                         i++, mclist = mclist->next) {
 167                 add_multi(tun->net_filter, mclist->dmi_addr);
 168                 DBG(KERN_DEBUG "%s: tun_net_mclist: %x:%x:%x:%x:%x:%x\n",
 169                                 dev->name,
 170                                 mclist->dmi_addr[0], mclist->dmi_addr[1], mclist->dmi_addr[2],
 171                                 mclist->dmi_addr[3], mclist->dmi_addr[4], mclist->dmi_addr[5]);
 172         }
 173 }
 174
 175 #define MIN_MTU 68
 176 #define MAX_MTU 65535
 177
 178 static int
 179 tun_net_change_mtu(struct net_device *dev, int new_mtu)
 180 {
 181         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
 182                 return -EINVAL;
 183         dev->mtu = new_mtu;
 184         return 0;
 185 }
 186
 187 /* Initialize net device. */
 188 static void tun_net_init(struct net_device *dev)
 189 {
 190         struct tun_struct *tun = netdev_priv(dev);
 191
 192         switch (tun->flags & TUN_TYPE_MASK) {
 193         case TUN_TUN_DEV:
 194                 /* Point-to-Point TUN Device */
 195                 dev->hard_header_len = 0;
 196                 dev->addr_len = 0;
 197                 dev->mtu = 1500;
 198                 dev->change_mtu = tun_net_change_mtu;
 199
 200                 /* Zero header length */
 201                 dev->type = ARPHRD_NONE;
 202                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 203                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 204                 break;
 205
 206         case TUN_TAP_DEV:
 207                 /* Ethernet TAP Device */
 208                 dev->set_multicast_list = tun_net_mclist;
 209
 210                 ether_setup(dev);
 211                 dev->change_mtu = tun_net_change_mtu;
 212
 213                 /* random address already created for us by tun_set_iff, use it */
 214                 memcpy(dev->dev_addr, tun->dev_addr, min(sizeof(tun->dev_addr), sizeof(dev->dev_addr)) );
 215
 216                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 217                 break;
 218         }
 219 }
 220
 221 /* Character device part */
 222
 223 /* Poll */
 224 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
 225 {
 226         struct tun_struct *tun = file->private_data;
 227         unsigned int mask = POLLOUT | POLLWRNORM;
 228
 229         if (!tun)
 230                 return -EBADFD;
 231
 232         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
 233
 234         poll_wait(file, &tun->read_wait, wait);
 235
 236         if (!skb_queue_empty(&tun->readq))
 237                 mask |= POLLIN | POLLRDNORM;
 238
 239         return mask;
 240 }
 241
 242 /* Get packet from user space buffer */
 243 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
 244 {
 245         struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
 246         struct sk_buff *skb;
 247         size_t len = count, align = 0;
 248
 249         if (!(tun->flags & TUN_NO_PI)) {
 250                 if ((len -= sizeof(pi)) > count)
 251                         return -EINVAL;
 252
 253                 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
 254                         return -EFAULT;
 255         }
 256
 257         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV)
 258                 align = NET_IP_ALIGN;
 259
 260         if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
 261                 tun->dev->stats.rx_dropped++;
 262                 return -ENOMEM;
 263         }
 264
 265         if (align)
 266                 skb_reserve(skb, align);
 267         if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
 268                 tun->dev->stats.rx_dropped++;
 269                 kfree_skb(skb);
 270                 return -EFAULT;
 271         }
 272
 273         switch (tun->flags & TUN_TYPE_MASK) {
 274         case TUN_TUN_DEV:
 275                 skb_reset_mac_header(skb);
 276                 skb->protocol = pi.proto;
 277                 skb->dev = tun->dev;
 278                 break;
 279         case TUN_TAP_DEV:
 280                 skb->protocol = eth_type_trans(skb, tun->dev);
 281                 break;
 282         };
 283
 284         if (tun->flags & TUN_NOCHECKSUM)
 285                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 286
 287         netif_rx_ni(skb);
 288         tun->dev->last_rx = jiffies;
 289
 290         tun->dev->stats.rx_packets++;
 291         tun->dev->stats.rx_bytes += len;
 292
 293         return count;
 294 }
 295
 296 static inline size_t iov_total(const struct iovec *iv, unsigned long count)
 297 {
 298         unsigned long i;
 299         size_t len;
 300
 301         for (i = 0, len = 0; i < count; i++)
 302                 len += iv[i].iov_len;
 303
 304         return len;
 305 }
 306
 307 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
 308                               unsigned long count, loff_t pos)
 309 {
 310         struct tun_struct *tun = iocb->ki_filp->private_data;
 311
 312         if (!tun)
 313                 return -EBADFD;
 314
 315         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
 316
 317         return tun_get_user(tun, (struct iovec *) iv, iov_total(iv, count));
 318 }
 319
 320 /* Put packet to the user space buffer */
 321 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
 322                                        struct sk_buff *skb,
 323                                        struct iovec *iv, int len)
 324 {
 325         struct tun_pi pi = { 0, skb->protocol };
 326         ssize_t total = 0;
 327
 328         if (!(tun->flags & TUN_NO_PI)) {
 329                 if ((len -= sizeof(pi)) < 0)
 330                         return -EINVAL;
 331
 332                 if (len < skb->len) {
 333                         /* Packet will be striped */
 334                         pi.flags |= TUN_PKT_STRIP;
 335                 }
 336
 337                 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
 338                         return -EFAULT;
 339                 total += sizeof(pi);
 340         }
 341
 342         len = min_t(int, skb->len, len);
 343
 344         skb_copy_datagram_iovec(skb, 0, iv, len);
 345         total += len;
 346
 347         tun->dev->stats.tx_packets++;
 348         tun->dev->stats.tx_bytes += len;
 349
 350         return total;
 351 }
 352
 353 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
 354                             unsigned long count, loff_t pos)
 355 {
 356         struct file *file = iocb->ki_filp;
 357         struct tun_struct *tun = file->private_data;
 358         DECLARE_WAITQUEUE(wait, current);
 359         struct sk_buff *skb;
 360         ssize_t len, ret = 0;
 361
 362         if (!tun)
 363                 return -EBADFD;
 364
 365         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
 366
 367         len = iov_total(iv, count);
 368         if (len < 0)
 369                 return -EINVAL;
 370
 371         add_wait_queue(&tun->read_wait, &wait);
 372         while (len) {
 373                 const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 374                 u8 addr[ ETH_ALEN];
 375                 int bit_nr;
 376
 377                 current->state = TASK_INTERRUPTIBLE;
 378
 379                 /* Read frames from the queue */
 380                 if (!(skb=skb_dequeue(&tun->readq))) {
 381                         if (file->f_flags & O_NONBLOCK) {
 382                                 ret = -EAGAIN;
 383                                 break;
 384                         }
 385                         if (signal_pending(current)) {
 386                                 ret = -ERESTARTSYS;
 387                                 break;
 388                         }
 389
 390                         /* Nothing to read, let's sleep */
 391                         schedule();
 392                         continue;
 393                 }
 394                 netif_wake_queue(tun->dev);
 395
 396                 /** Decide whether to accept this packet. This code is designed to
 397                  * behave identically to an Ethernet interface. Accept the packet if
 398                  * - we are promiscuous.
 399                  * - the packet is addressed to us.
 400                  * - the packet is broadcast.
 401                  * - the packet is multicast and
 402                  *   - we are multicast promiscous.
 403                  *   - we belong to the multicast group.
 404                  */
 405                 skb_copy_from_linear_data(skb, addr, min_t(size_t, sizeof addr,
 406                                                                    skb->len));
 407                 bit_nr = ether_crc(sizeof addr, addr) >> 26;
 408                 if ((tun->if_flags & IFF_PROMISC) ||
 409                                 memcmp(addr, tun->dev_addr, sizeof addr) == 0 ||
 410                                 memcmp(addr, ones, sizeof addr) == 0 ||
 411                                 (((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) ||
 412                                   (addr[0] == 0x33 && addr[1] == 0x33)) &&
 413                                  ((tun->if_flags & IFF_ALLMULTI) ||
 414                                   (tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) {
 415                         DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %x:%x:%x:%x:%x:%x\n",
 416                                         tun->dev->name, addr[0], addr[1], addr[2],
 417                                         addr[3], addr[4], addr[5]);
 418                         ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
 419                         kfree_skb(skb);
 420                         break;
 421                 } else {
 422                         DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %x:%x:%x:%x:%x:%x\n",
 423                                         tun->dev->name, addr[0], addr[1], addr[2],
 424                                         addr[3], addr[4], addr[5]);
 425                         kfree_skb(skb);
 426                         continue;
 427                 }
 428         }
 429
 430         current->state = TASK_RUNNING;
 431         remove_wait_queue(&tun->read_wait, &wait);
 432
 433         return ret;
 434 }
 435
 436 static void tun_setup(struct net_device *dev)
 437 {
 438         struct tun_struct *tun = netdev_priv(dev);
 439
 440         skb_queue_head_init(&tun->readq);
 441         init_waitqueue_head(&tun->read_wait);
 442
 443         tun->owner = -1;
 444         tun->group = -1;
 445
 446         dev->open = tun_net_open;
 447         dev->hard_start_xmit = tun_net_xmit;
 448         dev->stop = tun_net_close;
 449         dev->ethtool_ops = &tun_ethtool_ops;
 450         dev->destructor = free_netdev;
 451 }
 452
 453 static struct tun_struct *tun_get_by_name(const char *name)
 454 {
 455         struct tun_struct *tun;
 456
 457         ASSERT_RTNL();
 458         list_for_each_entry(tun, &tun_dev_list, list) {
 459                 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
 460                     return tun;
 461         }
 462
 463         return NULL;
 464 }
 465
 466 static int tun_set_iff(struct file *file, struct ifreq *ifr)
 467 {
 468         struct tun_struct *tun;
 469         struct net_device *dev;
 470         int err;
 471
 472         tun = tun_get_by_name(ifr->ifr_name);
 473         if (tun) {
 474                 if (tun->attached)
 475                         return -EBUSY;
 476
 477                 /* Check permissions */
 478                 if (((tun->owner != -1 &&
 479                       current->euid != tun->owner) ||
 480                      (tun->group != -1 &&
 481                       current->egid != tun->group)) &&
 482                      !capable(CAP_NET_ADMIN))
 483                         return -EPERM;
 484         }
 485         else if (__dev_get_by_name(&init_net, 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 TUNSETGROUP:
 625                 /* Set group of the device */
 626                 tun->group= (gid_t) arg;
 627
 628                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
 629                 break;
 630
 631         case TUNSETLINK:
 632                 /* Only allow setting the type when the interface is down */
 633                 if (tun->dev->flags & IFF_UP) {
 634                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
 635                                 tun->dev->name);
 636                         return -EBUSY;
 637                 } else {
 638                         tun->dev->type = (int) arg;
 639                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
 640                 }
 641                 break;
 642
 643 #ifdef TUN_DEBUG
 644         case TUNSETDEBUG:
 645                 tun->debug = arg;
 646                 break;
 647 #endif
 648
 649         case SIOCGIFFLAGS:
 650                 ifr.ifr_flags = tun->if_flags;
 651                 if (copy_to_user( argp, &ifr, sizeof ifr))
 652                         return -EFAULT;
 653                 return 0;
 654
 655         case SIOCSIFFLAGS:
 656                 /** Set the character device's interface flags. Currently only
 657                  * IFF_PROMISC and IFF_ALLMULTI are used. */
 658                 tun->if_flags = ifr.ifr_flags;
 659                 DBG(KERN_INFO "%s: interface flags 0x%lx\n",
 660                                 tun->dev->name, tun->if_flags);
 661                 return 0;
 662
 663         case SIOCGIFHWADDR:
 664                 /* Note: the actual net device's address may be different */
 665                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr,
 666                                 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
 667                 if (copy_to_user( argp, &ifr, sizeof ifr))
 668                         return -EFAULT;
 669                 return 0;
 670
 671         case SIOCSIFHWADDR:
 672         {
 673                 /* try to set the actual net device's hw address */
 674                 int ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
 675
 676                 if (ret == 0) {
 677                         /** Set the character device's hardware address. This is used when
 678                          * filtering packets being sent from the network device to the character
 679                          * device. */
 680                         memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data,
 681                                         min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
 682                         DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n",
 683                                         tun->dev->name,
 684                                         tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2],
 685                                         tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]);
 686                 }
 687
 688                 return  ret;
 689         }
 690
 691         case SIOCADDMULTI:
 692                 /** Add the specified group to the character device's multicast filter
 693                  * list. */
 694                 add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
 695                 DBG(KERN_DEBUG "%s: add multi: %x:%x:%x:%x:%x:%x\n",
 696                                 tun->dev->name,
 697                                 (u8)ifr.ifr_hwaddr.sa_data[0], (u8)ifr.ifr_hwaddr.sa_data[1],
 698                                 (u8)ifr.ifr_hwaddr.sa_data[2], (u8)ifr.ifr_hwaddr.sa_data[3],
 699                                 (u8)ifr.ifr_hwaddr.sa_data[4], (u8)ifr.ifr_hwaddr.sa_data[5]);
 700                 return 0;
 701
 702         case SIOCDELMULTI:
 703                 /** Remove the specified group from the character device's multicast
 704                  * filter list. */
 705                 del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
 706                 DBG(KERN_DEBUG "%s: del multi: %x:%x:%x:%x:%x:%x\n",
 707                                 tun->dev->name,
 708                                 (u8)ifr.ifr_hwaddr.sa_data[0], (u8)ifr.ifr_hwaddr.sa_data[1],
 709                                 (u8)ifr.ifr_hwaddr.sa_data[2], (u8)ifr.ifr_hwaddr.sa_data[3],
 710                                 (u8)ifr.ifr_hwaddr.sa_data[4], (u8)ifr.ifr_hwaddr.sa_data[5]);
 711                 return 0;
 712
 713         default:
 714                 return -EINVAL;
 715         };
 716
 717         return 0;
 718 }
 719
 720 static int tun_chr_fasync(int fd, struct file *file, int on)
 721 {
 722         struct tun_struct *tun = file->private_data;
 723         int ret;
 724
 725         if (!tun)
 726                 return -EBADFD;
 727
 728         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
 729
 730         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
 731                 return ret;
 732
 733         if (on) {
 734                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
 735                 if (ret)
 736                         return ret;
 737                 tun->flags |= TUN_FASYNC;
 738         } else
 739                 tun->flags &= ~TUN_FASYNC;
 740
 741         return 0;
 742 }
 743
 744 static int tun_chr_open(struct inode *inode, struct file * file)
 745 {
 746         DBG1(KERN_INFO "tunX: tun_chr_open\n");
 747         file->private_data = NULL;
 748         return 0;
 749 }
 750
 751 static int tun_chr_close(struct inode *inode, struct file *file)
 752 {
 753         struct tun_struct *tun = file->private_data;
 754
 755         if (!tun)
 756                 return 0;
 757
 758         DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
 759
 760         tun_chr_fasync(-1, file, 0);
 761
 762         rtnl_lock();
 763
 764         /* Detach from net device */
 765         file->private_data = NULL;
 766         tun->attached = 0;
 767
 768         /* Drop read queue */
 769         skb_queue_purge(&tun->readq);
 770
 771         if (!(tun->flags & TUN_PERSIST)) {
 772                 list_del(&tun->list);
 773                 unregister_netdevice(tun->dev);
 774         }
 775
 776         rtnl_unlock();
 777
 778         return 0;
 779 }
 780
 781 static const struct file_operations tun_fops = {
 782         .owner  = THIS_MODULE,
 783         .llseek = no_llseek,
 784         .read  = do_sync_read,
 785         .aio_read  = tun_chr_aio_read,
 786         .write = do_sync_write,
 787         .aio_write = tun_chr_aio_write,
 788         .poll   = tun_chr_poll,
 789         .ioctl  = tun_chr_ioctl,
 790         .open   = tun_chr_open,
 791         .release = tun_chr_close,
 792         .fasync = tun_chr_fasync
 793 };
 794
 795 static struct miscdevice tun_miscdev = {
 796         .minor = TUN_MINOR,
 797         .name = "tun",
 798         .fops = &tun_fops,
 799 };
 800
 801 /* ethtool interface */
 802
 803 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 804 {
 805         cmd->supported          = 0;
 806         cmd->advertising        = 0;
 807         cmd->speed              = SPEED_10;
 808         cmd->duplex             = DUPLEX_FULL;
 809         cmd->port               = PORT_TP;
 810         cmd->phy_address        = 0;
 811         cmd->transceiver        = XCVR_INTERNAL;
 812         cmd->autoneg            = AUTONEG_DISABLE;
 813         cmd->maxtxpkt           = 0;
 814         cmd->maxrxpkt           = 0;
 815         return 0;
 816 }
 817
 818 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 819 {
 820         struct tun_struct *tun = netdev_priv(dev);
 821
 822         strcpy(info->driver, DRV_NAME);
 823         strcpy(info->version, DRV_VERSION);
 824         strcpy(info->fw_version, "N/A");
 825
 826         switch (tun->flags & TUN_TYPE_MASK) {
 827         case TUN_TUN_DEV:
 828                 strcpy(info->bus_info, "tun");
 829                 break;
 830         case TUN_TAP_DEV:
 831                 strcpy(info->bus_info, "tap");
 832                 break;
 833         }
 834 }
 835
 836 static u32 tun_get_msglevel(struct net_device *dev)
 837 {
 838 #ifdef TUN_DEBUG
 839         struct tun_struct *tun = netdev_priv(dev);
 840         return tun->debug;
 841 #else
 842         return -EOPNOTSUPP;
 843 #endif
 844 }
 845
 846 static void tun_set_msglevel(struct net_device *dev, u32 value)
 847 {
 848 #ifdef TUN_DEBUG
 849         struct tun_struct *tun = netdev_priv(dev);
 850         tun->debug = value;
 851 #endif
 852 }
 853
 854 static u32 tun_get_link(struct net_device *dev)
 855 {
 856         struct tun_struct *tun = netdev_priv(dev);
 857         return tun->attached;
 858 }
 859
 860 static u32 tun_get_rx_csum(struct net_device *dev)
 861 {
 862         struct tun_struct *tun = netdev_priv(dev);
 863         return (tun->flags & TUN_NOCHECKSUM) == 0;
 864 }
 865
 866 static int tun_set_rx_csum(struct net_device *dev, u32 data)
 867 {
 868         struct tun_struct *tun = netdev_priv(dev);
 869         if (data)
 870                 tun->flags &= ~TUN_NOCHECKSUM;
 871         else
 872                 tun->flags |= TUN_NOCHECKSUM;
 873         return 0;
 874 }
 875
 876 static const struct ethtool_ops tun_ethtool_ops = {
 877         .get_settings   = tun_get_settings,
 878         .get_drvinfo    = tun_get_drvinfo,
 879         .get_msglevel   = tun_get_msglevel,
 880         .set_msglevel   = tun_set_msglevel,
 881         .get_link       = tun_get_link,
 882         .get_rx_csum    = tun_get_rx_csum,
 883         .set_rx_csum    = tun_set_rx_csum
 884 };
 885
 886 static int __init tun_init(void)
 887 {
 888         int ret = 0;
 889
 890         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
 891         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
 892
 893         ret = misc_register(&tun_miscdev);
 894         if (ret)
 895                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
 896         return ret;
 897 }
 898
 899 static void tun_cleanup(void)
 900 {
 901         struct tun_struct *tun, *nxt;
 902
 903         misc_deregister(&tun_miscdev);
 904
 905         rtnl_lock();
 906         list_for_each_entry_safe(tun, nxt, &tun_dev_list, list) {
 907                 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
 908                 unregister_netdevice(tun->dev);
 909         }
 910         rtnl_unlock();
 911
 912 }
 913
 914 module_init(tun_init);
 915 module_exit(tun_cleanup);
 916 MODULE_DESCRIPTION(DRV_DESCRIPTION);
 917 MODULE_AUTHOR(DRV_COPYRIGHT);
 918 MODULE_LICENSE("GPL");
 919 MODULE_ALIAS_MISCDEV(TUN_MINOR);