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/smp_lock.h>
  52 #include <linux/poll.h>
  53 #include <linux/fcntl.h>
  54 #include <linux/init.h>
  55 #include <linux/skbuff.h>
  56 #include <linux/netdevice.h>
  57 #include <linux/etherdevice.h>
  58 #include <linux/miscdevice.h>
  59 #include <linux/ethtool.h>
  60 #include <linux/rtnetlink.h>
  61 #include <linux/if.h>
  62 #include <linux/if_arp.h>
  63 #include <linux/if_ether.h>
  64 #include <linux/if_tun.h>
  65 #include <linux/crc32.h>
  66 #include <linux/nsproxy.h>
  67 #include <net/net_namespace.h>
  68 #include <net/netns/generic.h>
  69
  70 #include <asm/system.h>
  71 #include <asm/uaccess.h>
  72
  73 /* Uncomment to enable debugging */
  74 /* #define TUN_DEBUG 1 */
  75
  76 #ifdef TUN_DEBUG
  77 static int debug;
  78
  79 #define DBG  if(tun->debug)printk
  80 #define DBG1 if(debug==2)printk
  81 #else
  82 #define DBG( a... )
  83 #define DBG1( a... )
  84 #endif
  85
  86 struct tun_struct {
  87         struct list_head        list;
  88         unsigned long           flags;
  89         int                     attached;
  90         uid_t                   owner;
  91         gid_t                   group;
  92
  93         wait_queue_head_t       read_wait;
  94         struct sk_buff_head     readq;
  95
  96         struct net_device       *dev;
  97
  98         struct fasync_struct    *fasync;
  99
 100         unsigned long if_flags;
 101         u8 dev_addr[ETH_ALEN];
 102         u32 chr_filter[2];
 103         u32 net_filter[2];
 104
 105 #ifdef TUN_DEBUG
 106         int debug;
 107 #endif
 108 };
 109
 110 /* Network device part of the driver */
 111
 112 static unsigned int tun_net_id;
 113 struct tun_net {
 114         struct list_head dev_list;
 115 };
 116
 117 static const struct ethtool_ops tun_ethtool_ops;
 118
 119 /* Net device open. */
 120 static int tun_net_open(struct net_device *dev)
 121 {
 122         netif_start_queue(dev);
 123         return 0;
 124 }
 125
 126 /* Net device close. */
 127 static int tun_net_close(struct net_device *dev)
 128 {
 129         netif_stop_queue(dev);
 130         return 0;
 131 }
 132
 133 /* Net device start xmit */
 134 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 135 {
 136         struct tun_struct *tun = netdev_priv(dev);
 137
 138         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
 139
 140         /* Drop packet if interface is not attached */
 141         if (!tun->attached)
 142                 goto drop;
 143
 144         /* Packet dropping */
 145         if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
 146                 if (!(tun->flags & TUN_ONE_QUEUE)) {
 147                         /* Normal queueing mode. */
 148                         /* Packet scheduler handles dropping of further packets. */
 149                         netif_stop_queue(dev);
 150
 151                         /* We won't see all dropped packets individually, so overrun
 152                          * error is more appropriate. */
 153                         dev->stats.tx_fifo_errors++;
 154                 } else {
 155                         /* Single queue mode.
 156                          * Driver handles dropping of all packets itself. */
 157                         goto drop;
 158                 }
 159         }
 160
 161         /* Queue packet */
 162         skb_queue_tail(&tun->readq, skb);
 163         dev->trans_start = jiffies;
 164
 165         /* Notify and wake up reader process */
 166         if (tun->flags & TUN_FASYNC)
 167                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
 168         wake_up_interruptible(&tun->read_wait);
 169         return 0;
 170
 171 drop:
 172         dev->stats.tx_dropped++;
 173         kfree_skb(skb);
 174         return 0;
 175 }
 176
 177 /** Add the specified Ethernet address to this multicast filter. */
 178 static void
 179 add_multi(u32* filter, const u8* addr)
 180 {
 181         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
 182         filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
 183 }
 184
 185 /** Remove the specified Ethernet addres from this multicast filter. */
 186 static void
 187 del_multi(u32* filter, const u8* addr)
 188 {
 189         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
 190         filter[bit_nr >> 5] &= ~(1 << (bit_nr & 31));
 191 }
 192
 193 /** Update the list of multicast groups to which the network device belongs.
 194  * This list is used to filter packets being sent from the character device to
 195  * the network device. */
 196 static void
 197 tun_net_mclist(struct net_device *dev)
 198 {
 199         struct tun_struct *tun = netdev_priv(dev);
 200         const struct dev_mc_list *mclist;
 201         int i;
 202         DECLARE_MAC_BUF(mac);
 203         DBG(KERN_DEBUG "%s: tun_net_mclist: mc_count %d\n",
 204                         dev->name, dev->mc_count);
 205         memset(tun->chr_filter, 0, sizeof tun->chr_filter);
 206         for (i = 0, mclist = dev->mc_list; i < dev->mc_count && mclist != NULL;
 207                         i++, mclist = mclist->next) {
 208                 add_multi(tun->net_filter, mclist->dmi_addr);
 209                 DBG(KERN_DEBUG "%s: tun_net_mclist: %s\n",
 210                     dev->name, print_mac(mac, mclist->dmi_addr));
 211         }
 212 }
 213
 214 #define MIN_MTU 68
 215 #define MAX_MTU 65535
 216
 217 static int
 218 tun_net_change_mtu(struct net_device *dev, int new_mtu)
 219 {
 220         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
 221                 return -EINVAL;
 222         dev->mtu = new_mtu;
 223         return 0;
 224 }
 225
 226 /* Initialize net device. */
 227 static void tun_net_init(struct net_device *dev)
 228 {
 229         struct tun_struct *tun = netdev_priv(dev);
 230
 231         switch (tun->flags & TUN_TYPE_MASK) {
 232         case TUN_TUN_DEV:
 233                 /* Point-to-Point TUN Device */
 234                 dev->hard_header_len = 0;
 235                 dev->addr_len = 0;
 236                 dev->mtu = 1500;
 237                 dev->change_mtu = tun_net_change_mtu;
 238
 239                 /* Zero header length */
 240                 dev->type = ARPHRD_NONE;
 241                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 242                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 243                 break;
 244
 245         case TUN_TAP_DEV:
 246                 /* Ethernet TAP Device */
 247                 dev->set_multicast_list = tun_net_mclist;
 248
 249                 ether_setup(dev);
 250                 dev->change_mtu = tun_net_change_mtu;
 251
 252                 /* random address already created for us by tun_set_iff, use it */
 253                 memcpy(dev->dev_addr, tun->dev_addr, min(sizeof(tun->dev_addr), sizeof(dev->dev_addr)) );
 254
 255                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 256                 break;
 257         }
 258 }
 259
 260 /* Character device part */
 261
 262 /* Poll */
 263 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
 264 {
 265         struct tun_struct *tun = file->private_data;
 266         unsigned int mask = POLLOUT | POLLWRNORM;
 267
 268         if (!tun)
 269                 return -EBADFD;
 270
 271         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
 272
 273         poll_wait(file, &tun->read_wait, wait);
 274
 275         if (!skb_queue_empty(&tun->readq))
 276                 mask |= POLLIN | POLLRDNORM;
 277
 278         return mask;
 279 }
 280
 281 /* Get packet from user space buffer */
 282 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
 283 {
 284         struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
 285         struct sk_buff *skb;
 286         size_t len = count, align = 0;
 287
 288         if (!(tun->flags & TUN_NO_PI)) {
 289                 if ((len -= sizeof(pi)) > count)
 290                         return -EINVAL;
 291
 292                 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
 293                         return -EFAULT;
 294         }
 295
 296         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
 297                 align = NET_IP_ALIGN;
 298                 if (unlikely(len < ETH_HLEN))
 299                         return -EINVAL;
 300         }
 301
 302         if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
 303                 tun->dev->stats.rx_dropped++;
 304                 return -ENOMEM;
 305         }
 306
 307         if (align)
 308                 skb_reserve(skb, align);
 309         if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
 310                 tun->dev->stats.rx_dropped++;
 311                 kfree_skb(skb);
 312                 return -EFAULT;
 313         }
 314
 315         switch (tun->flags & TUN_TYPE_MASK) {
 316         case TUN_TUN_DEV:
 317                 skb_reset_mac_header(skb);
 318                 skb->protocol = pi.proto;
 319                 skb->dev = tun->dev;
 320                 break;
 321         case TUN_TAP_DEV:
 322                 skb->protocol = eth_type_trans(skb, tun->dev);
 323                 break;
 324         };
 325
 326         if (tun->flags & TUN_NOCHECKSUM)
 327                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 328
 329         netif_rx_ni(skb);
 330         tun->dev->last_rx = jiffies;
 331
 332         tun->dev->stats.rx_packets++;
 333         tun->dev->stats.rx_bytes += len;
 334
 335         return count;
 336 }
 337
 338 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
 339                               unsigned long count, loff_t pos)
 340 {
 341         struct tun_struct *tun = iocb->ki_filp->private_data;
 342
 343         if (!tun)
 344                 return -EBADFD;
 345
 346         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
 347
 348         return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
 349 }
 350
 351 /* Put packet to the user space buffer */
 352 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
 353                                        struct sk_buff *skb,
 354                                        struct iovec *iv, int len)
 355 {
 356         struct tun_pi pi = { 0, skb->protocol };
 357         ssize_t total = 0;
 358
 359         if (!(tun->flags & TUN_NO_PI)) {
 360                 if ((len -= sizeof(pi)) < 0)
 361                         return -EINVAL;
 362
 363                 if (len < skb->len) {
 364                         /* Packet will be striped */
 365                         pi.flags |= TUN_PKT_STRIP;
 366                 }
 367
 368                 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
 369                         return -EFAULT;
 370                 total += sizeof(pi);
 371         }
 372
 373         len = min_t(int, skb->len, len);
 374
 375         skb_copy_datagram_iovec(skb, 0, iv, len);
 376         total += len;
 377
 378         tun->dev->stats.tx_packets++;
 379         tun->dev->stats.tx_bytes += len;
 380
 381         return total;
 382 }
 383
 384 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
 385                             unsigned long count, loff_t pos)
 386 {
 387         struct file *file = iocb->ki_filp;
 388         struct tun_struct *tun = file->private_data;
 389         DECLARE_WAITQUEUE(wait, current);
 390         struct sk_buff *skb;
 391         ssize_t len, ret = 0;
 392         DECLARE_MAC_BUF(mac);
 393
 394         if (!tun)
 395                 return -EBADFD;
 396
 397         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
 398
 399         len = iov_length(iv, count);
 400         if (len < 0)
 401                 return -EINVAL;
 402
 403         add_wait_queue(&tun->read_wait, &wait);
 404         while (len) {
 405                 const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 406                 u8 addr[ ETH_ALEN];
 407                 int bit_nr;
 408
 409                 current->state = TASK_INTERRUPTIBLE;
 410
 411                 /* Read frames from the queue */
 412                 if (!(skb=skb_dequeue(&tun->readq))) {
 413                         if (file->f_flags & O_NONBLOCK) {
 414                                 ret = -EAGAIN;
 415                                 break;
 416                         }
 417                         if (signal_pending(current)) {
 418                                 ret = -ERESTARTSYS;
 419                                 break;
 420                         }
 421
 422                         /* Nothing to read, let's sleep */
 423                         schedule();
 424                         continue;
 425                 }
 426                 netif_wake_queue(tun->dev);
 427
 428                 /** Decide whether to accept this packet. This code is designed to
 429                  * behave identically to an Ethernet interface. Accept the packet if
 430                  * - we are promiscuous.
 431                  * - the packet is addressed to us.
 432                  * - the packet is broadcast.
 433                  * - the packet is multicast and
 434                  *   - we are multicast promiscous.
 435                  *   - we belong to the multicast group.
 436                  */
 437                 skb_copy_from_linear_data(skb, addr, min_t(size_t, sizeof addr,
 438                                                                    skb->len));
 439                 bit_nr = ether_crc(sizeof addr, addr) >> 26;
 440                 if ((tun->if_flags & IFF_PROMISC) ||
 441                                 memcmp(addr, tun->dev_addr, sizeof addr) == 0 ||
 442                                 memcmp(addr, ones, sizeof addr) == 0 ||
 443                                 (((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) ||
 444                                   (addr[0] == 0x33 && addr[1] == 0x33)) &&
 445                                  ((tun->if_flags & IFF_ALLMULTI) ||
 446                                   (tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) {
 447                         DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %s\n",
 448                                         tun->dev->name, print_mac(mac, addr));
 449                         ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
 450                         kfree_skb(skb);
 451                         break;
 452                 } else {
 453                         DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %s\n",
 454                                         tun->dev->name, print_mac(mac, addr));
 455                         kfree_skb(skb);
 456                         continue;
 457                 }
 458         }
 459
 460         current->state = TASK_RUNNING;
 461         remove_wait_queue(&tun->read_wait, &wait);
 462
 463         return ret;
 464 }
 465
 466 static void tun_setup(struct net_device *dev)
 467 {
 468         struct tun_struct *tun = netdev_priv(dev);
 469
 470         skb_queue_head_init(&tun->readq);
 471         init_waitqueue_head(&tun->read_wait);
 472
 473         tun->owner = -1;
 474         tun->group = -1;
 475
 476         dev->open = tun_net_open;
 477         dev->hard_start_xmit = tun_net_xmit;
 478         dev->stop = tun_net_close;
 479         dev->ethtool_ops = &tun_ethtool_ops;
 480         dev->destructor = free_netdev;
 481         dev->features |= NETIF_F_NETNS_LOCAL;
 482 }
 483
 484 static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name)
 485 {
 486         struct tun_struct *tun;
 487
 488         ASSERT_RTNL();
 489         list_for_each_entry(tun, &tn->dev_list, list) {
 490                 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
 491                     return tun;
 492         }
 493
 494         return NULL;
 495 }
 496
 497 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 498 {
 499         struct tun_net *tn;
 500         struct tun_struct *tun;
 501         struct net_device *dev;
 502         int err;
 503
 504         tn = net_generic(net, tun_net_id);
 505         tun = tun_get_by_name(tn, ifr->ifr_name);
 506         if (tun) {
 507                 if (tun->attached)
 508                         return -EBUSY;
 509
 510                 /* Check permissions */
 511                 if (((tun->owner != -1 &&
 512                       current->euid != tun->owner) ||
 513                      (tun->group != -1 &&
 514                       current->egid != tun->group)) &&
 515                      !capable(CAP_NET_ADMIN))
 516                         return -EPERM;
 517         }
 518         else if (__dev_get_by_name(net, ifr->ifr_name))
 519                 return -EINVAL;
 520         else {
 521                 char *name;
 522                 unsigned long flags = 0;
 523
 524                 err = -EINVAL;
 525
 526                 if (!capable(CAP_NET_ADMIN))
 527                         return -EPERM;
 528
 529                 /* Set dev type */
 530                 if (ifr->ifr_flags & IFF_TUN) {
 531                         /* TUN device */
 532                         flags |= TUN_TUN_DEV;
 533                         name = "tun%d";
 534                 } else if (ifr->ifr_flags & IFF_TAP) {
 535                         /* TAP device */
 536                         flags |= TUN_TAP_DEV;
 537                         name = "tap%d";
 538                 } else
 539                         goto failed;
 540
 541                 if (*ifr->ifr_name)
 542                         name = ifr->ifr_name;
 543
 544                 dev = alloc_netdev(sizeof(struct tun_struct), name,
 545                                    tun_setup);
 546                 if (!dev)
 547                         return -ENOMEM;
 548
 549                 dev_net_set(dev, net);
 550                 tun = netdev_priv(dev);
 551                 tun->dev = dev;
 552                 tun->flags = flags;
 553                 /* Be promiscuous by default to maintain previous behaviour. */
 554                 tun->if_flags = IFF_PROMISC;
 555                 /* Generate random Ethernet address. */
 556                 *(__be16 *)tun->dev_addr = htons(0x00FF);
 557                 get_random_bytes(tun->dev_addr + sizeof(u16), 4);
 558                 memset(tun->chr_filter, 0, sizeof tun->chr_filter);
 559
 560                 tun_net_init(dev);
 561
 562                 if (strchr(dev->name, '%')) {
 563                         err = dev_alloc_name(dev, dev->name);
 564                         if (err < 0)
 565                                 goto err_free_dev;
 566                 }
 567
 568                 err = register_netdevice(tun->dev);
 569                 if (err < 0)
 570                         goto err_free_dev;
 571
 572                 list_add(&tun->list, &tn->dev_list);
 573         }
 574
 575         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
 576
 577         if (ifr->ifr_flags & IFF_NO_PI)
 578                 tun->flags |= TUN_NO_PI;
 579         else
 580                 tun->flags &= ~TUN_NO_PI;
 581
 582         if (ifr->ifr_flags & IFF_ONE_QUEUE)
 583                 tun->flags |= TUN_ONE_QUEUE;
 584         else
 585                 tun->flags &= ~TUN_ONE_QUEUE;
 586
 587         file->private_data = tun;
 588         tun->attached = 1;
 589         get_net(dev_net(tun->dev));
 590
 591         strcpy(ifr->ifr_name, tun->dev->name);
 592         return 0;
 593
 594  err_free_dev:
 595         free_netdev(dev);
 596  failed:
 597         return err;
 598 }
 599
 600 static int tun_chr_ioctl(struct inode *inode, struct file *file,
 601                          unsigned int cmd, unsigned long arg)
 602 {
 603         struct tun_struct *tun = file->private_data;
 604         void __user* argp = (void __user*)arg;
 605         struct ifreq ifr;
 606         DECLARE_MAC_BUF(mac);
 607
 608         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
 609                 if (copy_from_user(&ifr, argp, sizeof ifr))
 610                         return -EFAULT;
 611
 612         if (cmd == TUNSETIFF && !tun) {
 613                 int err;
 614
 615                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
 616
 617                 rtnl_lock();
 618                 err = tun_set_iff(current->nsproxy->net_ns, file, &ifr);
 619                 rtnl_unlock();
 620
 621                 if (err)
 622                         return err;
 623
 624                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
 625                         return -EFAULT;
 626                 return 0;
 627         }
 628
 629         if (!tun)
 630                 return -EBADFD;
 631
 632         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
 633
 634         switch (cmd) {
 635         case TUNSETNOCSUM:
 636                 /* Disable/Enable checksum */
 637                 if (arg)
 638                         tun->flags |= TUN_NOCHECKSUM;
 639                 else
 640                         tun->flags &= ~TUN_NOCHECKSUM;
 641
 642                 DBG(KERN_INFO "%s: checksum %s\n",
 643                     tun->dev->name, arg ? "disabled" : "enabled");
 644                 break;
 645
 646         case TUNSETPERSIST:
 647                 /* Disable/Enable persist mode */
 648                 if (arg)
 649                         tun->flags |= TUN_PERSIST;
 650                 else
 651                         tun->flags &= ~TUN_PERSIST;
 652
 653                 DBG(KERN_INFO "%s: persist %s\n",
 654                     tun->dev->name, arg ? "enabled" : "disabled");
 655                 break;
 656
 657         case TUNSETOWNER:
 658                 /* Set owner of the device */
 659                 tun->owner = (uid_t) arg;
 660
 661                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
 662                 break;
 663
 664         case TUNSETGROUP:
 665                 /* Set group of the device */
 666                 tun->group= (gid_t) arg;
 667
 668                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
 669                 break;
 670
 671         case TUNSETLINK:
 672         {
 673                 int ret;
 674
 675                 /* Only allow setting the type when the interface is down */
 676                 rtnl_lock();
 677                 if (tun->dev->flags & IFF_UP) {
 678                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
 679                                 tun->dev->name);
 680                         ret = -EBUSY;
 681                 } else {
 682                         tun->dev->type = (int) arg;
 683                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
 684                         ret = 0;
 685                 }
 686                 rtnl_unlock();
 687                 return ret;
 688         }
 689
 690 #ifdef TUN_DEBUG
 691         case TUNSETDEBUG:
 692                 tun->debug = arg;
 693                 break;
 694 #endif
 695
 696         case SIOCGIFFLAGS:
 697                 ifr.ifr_flags = tun->if_flags;
 698                 if (copy_to_user( argp, &ifr, sizeof ifr))
 699                         return -EFAULT;
 700                 return 0;
 701
 702         case SIOCSIFFLAGS:
 703                 /** Set the character device's interface flags. Currently only
 704                  * IFF_PROMISC and IFF_ALLMULTI are used. */
 705                 tun->if_flags = ifr.ifr_flags;
 706                 DBG(KERN_INFO "%s: interface flags 0x%lx\n",
 707                                 tun->dev->name, tun->if_flags);
 708                 return 0;
 709
 710         case SIOCGIFHWADDR:
 711                 /* Note: the actual net device's address may be different */
 712                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr,
 713                                 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
 714                 if (copy_to_user( argp, &ifr, sizeof ifr))
 715                         return -EFAULT;
 716                 return 0;
 717
 718         case SIOCSIFHWADDR:
 719         {
 720                 /* try to set the actual net device's hw address */
 721                 int ret;
 722
 723                 rtnl_lock();
 724                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
 725                 rtnl_unlock();
 726
 727                 if (ret == 0) {
 728                         /** Set the character device's hardware address. This is used when
 729                          * filtering packets being sent from the network device to the character
 730                          * device. */
 731                         memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data,
 732                                         min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
 733                         DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n",
 734                                         tun->dev->name,
 735                                         tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2],
 736                                         tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]);
 737                 }
 738
 739                 return  ret;
 740         }
 741
 742         case SIOCADDMULTI:
 743                 /** Add the specified group to the character device's multicast filter
 744                  * list. */
 745                 rtnl_lock();
 746                 netif_tx_lock_bh(tun->dev);
 747                 add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
 748                 netif_tx_unlock_bh(tun->dev);
 749                 rtnl_unlock();
 750
 751                 DBG(KERN_DEBUG "%s: add multi: %s\n",
 752                     tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
 753                 return 0;
 754
 755         case SIOCDELMULTI:
 756                 /** Remove the specified group from the character device's multicast
 757                  * filter list. */
 758                 rtnl_lock();
 759                 netif_tx_lock_bh(tun->dev);
 760                 del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
 761                 netif_tx_unlock_bh(tun->dev);
 762                 rtnl_unlock();
 763
 764                 DBG(KERN_DEBUG "%s: del multi: %s\n",
 765                     tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
 766                 return 0;
 767
 768         default:
 769                 return -EINVAL;
 770         };
 771
 772         return 0;
 773 }
 774
 775 static int tun_chr_fasync(int fd, struct file *file, int on)
 776 {
 777         struct tun_struct *tun = file->private_data;
 778         int ret;
 779
 780         if (!tun)
 781                 return -EBADFD;
 782
 783         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
 784
 785         lock_kernel();
 786         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
 787                 goto out;
 788
 789         if (on) {
 790                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
 791                 if (ret)
 792                         goto out;
 793                 tun->flags |= TUN_FASYNC;
 794         } else
 795                 tun->flags &= ~TUN_FASYNC;
 796         ret = 0;
 797 out:
 798         unlock_kernel();
 799         return ret;
 800 }
 801
 802 static int tun_chr_open(struct inode *inode, struct file * file)
 803 {
 804         cycle_kernel_lock();
 805         DBG1(KERN_INFO "tunX: tun_chr_open\n");
 806         file->private_data = NULL;
 807         return 0;
 808 }
 809
 810 static int tun_chr_close(struct inode *inode, struct file *file)
 811 {
 812         struct tun_struct *tun = file->private_data;
 813
 814         if (!tun)
 815                 return 0;
 816
 817         DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
 818
 819         tun_chr_fasync(-1, file, 0);
 820
 821         rtnl_lock();
 822
 823         /* Detach from net device */
 824         file->private_data = NULL;
 825         tun->attached = 0;
 826         put_net(dev_net(tun->dev));
 827
 828         /* Drop read queue */
 829         skb_queue_purge(&tun->readq);
 830
 831         if (!(tun->flags & TUN_PERSIST)) {
 832                 list_del(&tun->list);
 833                 unregister_netdevice(tun->dev);
 834         }
 835
 836         rtnl_unlock();
 837
 838         return 0;
 839 }
 840
 841 static const struct file_operations tun_fops = {
 842         .owner  = THIS_MODULE,
 843         .llseek = no_llseek,
 844         .read  = do_sync_read,
 845         .aio_read  = tun_chr_aio_read,
 846         .write = do_sync_write,
 847         .aio_write = tun_chr_aio_write,
 848         .poll   = tun_chr_poll,
 849         .ioctl  = tun_chr_ioctl,
 850         .open   = tun_chr_open,
 851         .release = tun_chr_close,
 852         .fasync = tun_chr_fasync
 853 };
 854
 855 static struct miscdevice tun_miscdev = {
 856         .minor = TUN_MINOR,
 857         .name = "tun",
 858         .fops = &tun_fops,
 859 };
 860
 861 /* ethtool interface */
 862
 863 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 864 {
 865         cmd->supported          = 0;
 866         cmd->advertising        = 0;
 867         cmd->speed              = SPEED_10;
 868         cmd->duplex             = DUPLEX_FULL;
 869         cmd->port               = PORT_TP;
 870         cmd->phy_address        = 0;
 871         cmd->transceiver        = XCVR_INTERNAL;
 872         cmd->autoneg            = AUTONEG_DISABLE;
 873         cmd->maxtxpkt           = 0;
 874         cmd->maxrxpkt           = 0;
 875         return 0;
 876 }
 877
 878 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 879 {
 880         struct tun_struct *tun = netdev_priv(dev);
 881
 882         strcpy(info->driver, DRV_NAME);
 883         strcpy(info->version, DRV_VERSION);
 884         strcpy(info->fw_version, "N/A");
 885
 886         switch (tun->flags & TUN_TYPE_MASK) {
 887         case TUN_TUN_DEV:
 888                 strcpy(info->bus_info, "tun");
 889                 break;
 890         case TUN_TAP_DEV:
 891                 strcpy(info->bus_info, "tap");
 892                 break;
 893         }
 894 }
 895
 896 static u32 tun_get_msglevel(struct net_device *dev)
 897 {
 898 #ifdef TUN_DEBUG
 899         struct tun_struct *tun = netdev_priv(dev);
 900         return tun->debug;
 901 #else
 902         return -EOPNOTSUPP;
 903 #endif
 904 }
 905
 906 static void tun_set_msglevel(struct net_device *dev, u32 value)
 907 {
 908 #ifdef TUN_DEBUG
 909         struct tun_struct *tun = netdev_priv(dev);
 910         tun->debug = value;
 911 #endif
 912 }
 913
 914 static u32 tun_get_link(struct net_device *dev)
 915 {
 916         struct tun_struct *tun = netdev_priv(dev);
 917         return tun->attached;
 918 }
 919
 920 static u32 tun_get_rx_csum(struct net_device *dev)
 921 {
 922         struct tun_struct *tun = netdev_priv(dev);
 923         return (tun->flags & TUN_NOCHECKSUM) == 0;
 924 }
 925
 926 static int tun_set_rx_csum(struct net_device *dev, u32 data)
 927 {
 928         struct tun_struct *tun = netdev_priv(dev);
 929         if (data)
 930                 tun->flags &= ~TUN_NOCHECKSUM;
 931         else
 932                 tun->flags |= TUN_NOCHECKSUM;
 933         return 0;
 934 }
 935
 936 static const struct ethtool_ops tun_ethtool_ops = {
 937         .get_settings   = tun_get_settings,
 938         .get_drvinfo    = tun_get_drvinfo,
 939         .get_msglevel   = tun_get_msglevel,
 940         .set_msglevel   = tun_set_msglevel,
 941         .get_link       = tun_get_link,
 942         .get_rx_csum    = tun_get_rx_csum,
 943         .set_rx_csum    = tun_set_rx_csum
 944 };
 945
 946 static int tun_init_net(struct net *net)
 947 {
 948         struct tun_net *tn;
 949
 950         tn = kmalloc(sizeof(*tn), GFP_KERNEL);
 951         if (tn == NULL)
 952                 return -ENOMEM;
 953
 954         INIT_LIST_HEAD(&tn->dev_list);
 955
 956         if (net_assign_generic(net, tun_net_id, tn)) {
 957                 kfree(tn);
 958                 return -ENOMEM;
 959         }
 960
 961         return 0;
 962 }
 963
 964 static void tun_exit_net(struct net *net)
 965 {
 966         struct tun_net *tn;
 967         struct tun_struct *tun, *nxt;
 968
 969         tn = net_generic(net, tun_net_id);
 970
 971         rtnl_lock();
 972         list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) {
 973                 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
 974                 unregister_netdevice(tun->dev);
 975         }
 976         rtnl_unlock();
 977
 978         kfree(tn);
 979 }
 980
 981 static struct pernet_operations tun_net_ops = {
 982         .init = tun_init_net,
 983         .exit = tun_exit_net,
 984 };
 985
 986 static int __init tun_init(void)
 987 {
 988         int ret = 0;
 989
 990         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
 991         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
 992
 993         ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops);
 994         if (ret) {
 995                 printk(KERN_ERR "tun: Can't register pernet ops\n");
 996                 goto err_pernet;
 997         }
 998
 999         ret = misc_register(&tun_miscdev);
1000         if (ret) {
1001                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
1002                 goto err_misc;
1003         }
1004         return 0;
1005
1006 err_misc:
1007         unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1008 err_pernet:
1009         return ret;
1010 }
1011
1012 static void tun_cleanup(void)
1013 {
1014         misc_deregister(&tun_miscdev);
1015         unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1016 }
1017
1018 module_init(tun_init);
1019 module_exit(tun_cleanup);
1020 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1021 MODULE_AUTHOR(DRV_COPYRIGHT);
1022 MODULE_LICENSE("GPL");
1023 MODULE_ALIAS_MISCDEV(TUN_MINOR);