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   1 /*
   2  *  TUN - Universal TUN/TAP device driver.
   3  *  Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
  16  */
  17
  18 /*
  19  *  Changes:
  20  *
  21  *  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 <linux/nsproxy.h>
  66 #include <net/net_namespace.h>
  67 #include <net/netns/generic.h>
  68
  69 #include <asm/system.h>
  70 #include <asm/uaccess.h>
  71
  72 /* Uncomment to enable debugging */
  73 /* #define TUN_DEBUG 1 */
  74
  75 #ifdef TUN_DEBUG
  76 static int debug;
  77
  78 #define DBG  if(tun->debug)printk
  79 #define DBG1 if(debug==2)printk
  80 #else
  81 #define DBG( a... )
  82 #define DBG1( a... )
  83 #endif
  84
  85 struct tun_struct {
  86         struct list_head        list;
  87         unsigned long           flags;
  88         int                     attached;
  89         uid_t                   owner;
  90         gid_t                   group;
  91
  92         wait_queue_head_t       read_wait;
  93         struct sk_buff_head     readq;
  94
  95         struct net_device       *dev;
  96
  97         struct fasync_struct    *fasync;
  98
  99         unsigned long if_flags;
 100         u8 dev_addr[ETH_ALEN];
 101         u32 chr_filter[2];
 102         u32 net_filter[2];
 103
 104 #ifdef TUN_DEBUG
 105         int debug;
 106 #endif
 107 };
 108
 109 /* Network device part of the driver */
 110
 111 static unsigned int tun_net_id;
 112 struct tun_net {
 113         struct list_head dev_list;
 114 };
 115
 116 static const struct ethtool_ops tun_ethtool_ops;
 117
 118 /* Net device open. */
 119 static int tun_net_open(struct net_device *dev)
 120 {
 121         netif_start_queue(dev);
 122         return 0;
 123 }
 124
 125 /* Net device close. */
 126 static int tun_net_close(struct net_device *dev)
 127 {
 128         netif_stop_queue(dev);
 129         return 0;
 130 }
 131
 132 /* Net device start xmit */
 133 static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 134 {
 135         struct tun_struct *tun = netdev_priv(dev);
 136
 137         DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
 138
 139         /* Drop packet if interface is not attached */
 140         if (!tun->attached)
 141                 goto drop;
 142
 143         /* Packet dropping */
 144         if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) {
 145                 if (!(tun->flags & TUN_ONE_QUEUE)) {
 146                         /* Normal queueing mode. */
 147                         /* Packet scheduler handles dropping of further packets. */
 148                         netif_stop_queue(dev);
 149
 150                         /* We won't see all dropped packets individually, so overrun
 151                          * error is more appropriate. */
 152                         dev->stats.tx_fifo_errors++;
 153                 } else {
 154                         /* Single queue mode.
 155                          * Driver handles dropping of all packets itself. */
 156                         goto drop;
 157                 }
 158         }
 159
 160         /* Queue packet */
 161         skb_queue_tail(&tun->readq, skb);
 162         dev->trans_start = jiffies;
 163
 164         /* Notify and wake up reader process */
 165         if (tun->flags & TUN_FASYNC)
 166                 kill_fasync(&tun->fasync, SIGIO, POLL_IN);
 167         wake_up_interruptible(&tun->read_wait);
 168         return 0;
 169
 170 drop:
 171         dev->stats.tx_dropped++;
 172         kfree_skb(skb);
 173         return 0;
 174 }
 175
 176 /** Add the specified Ethernet address to this multicast filter. */
 177 static void
 178 add_multi(u32* filter, const u8* addr)
 179 {
 180         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
 181         filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
 182 }
 183
 184 /** Remove the specified Ethernet addres from this multicast filter. */
 185 static void
 186 del_multi(u32* filter, const u8* addr)
 187 {
 188         int bit_nr = ether_crc(ETH_ALEN, addr) >> 26;
 189         filter[bit_nr >> 5] &= ~(1 << (bit_nr & 31));
 190 }
 191
 192 /** Update the list of multicast groups to which the network device belongs.
 193  * This list is used to filter packets being sent from the character device to
 194  * the network device. */
 195 static void
 196 tun_net_mclist(struct net_device *dev)
 197 {
 198         struct tun_struct *tun = netdev_priv(dev);
 199         const struct dev_mc_list *mclist;
 200         int i;
 201         DECLARE_MAC_BUF(mac);
 202         DBG(KERN_DEBUG "%s: tun_net_mclist: mc_count %d\n",
 203                         dev->name, dev->mc_count);
 204         memset(tun->chr_filter, 0, sizeof tun->chr_filter);
 205         for (i = 0, mclist = dev->mc_list; i < dev->mc_count && mclist != NULL;
 206                         i++, mclist = mclist->next) {
 207                 add_multi(tun->net_filter, mclist->dmi_addr);
 208                 DBG(KERN_DEBUG "%s: tun_net_mclist: %s\n",
 209                     dev->name, print_mac(mac, mclist->dmi_addr));
 210         }
 211 }
 212
 213 #define MIN_MTU 68
 214 #define MAX_MTU 65535
 215
 216 static int
 217 tun_net_change_mtu(struct net_device *dev, int new_mtu)
 218 {
 219         if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
 220                 return -EINVAL;
 221         dev->mtu = new_mtu;
 222         return 0;
 223 }
 224
 225 /* Initialize net device. */
 226 static void tun_net_init(struct net_device *dev)
 227 {
 228         struct tun_struct *tun = netdev_priv(dev);
 229
 230         switch (tun->flags & TUN_TYPE_MASK) {
 231         case TUN_TUN_DEV:
 232                 /* Point-to-Point TUN Device */
 233                 dev->hard_header_len = 0;
 234                 dev->addr_len = 0;
 235                 dev->mtu = 1500;
 236                 dev->change_mtu = tun_net_change_mtu;
 237
 238                 /* Zero header length */
 239                 dev->type = ARPHRD_NONE;
 240                 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 241                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 242                 break;
 243
 244         case TUN_TAP_DEV:
 245                 /* Ethernet TAP Device */
 246                 dev->set_multicast_list = tun_net_mclist;
 247
 248                 ether_setup(dev);
 249                 dev->change_mtu = tun_net_change_mtu;
 250
 251                 /* random address already created for us by tun_set_iff, use it */
 252                 memcpy(dev->dev_addr, tun->dev_addr, min(sizeof(tun->dev_addr), sizeof(dev->dev_addr)) );
 253
 254                 dev->tx_queue_len = TUN_READQ_SIZE;  /* We prefer our own queue length */
 255                 break;
 256         }
 257 }
 258
 259 /* Character device part */
 260
 261 /* Poll */
 262 static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
 263 {
 264         struct tun_struct *tun = file->private_data;
 265         unsigned int mask = POLLOUT | POLLWRNORM;
 266
 267         if (!tun)
 268                 return -EBADFD;
 269
 270         DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
 271
 272         poll_wait(file, &tun->read_wait, wait);
 273
 274         if (!skb_queue_empty(&tun->readq))
 275                 mask |= POLLIN | POLLRDNORM;
 276
 277         return mask;
 278 }
 279
 280 /* Get packet from user space buffer */
 281 static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
 282 {
 283         struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
 284         struct sk_buff *skb;
 285         size_t len = count, align = 0;
 286
 287         if (!(tun->flags & TUN_NO_PI)) {
 288                 if ((len -= sizeof(pi)) > count)
 289                         return -EINVAL;
 290
 291                 if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
 292                         return -EFAULT;
 293         }
 294
 295         if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) {
 296                 align = NET_IP_ALIGN;
 297                 if (unlikely(len < ETH_HLEN))
 298                         return -EINVAL;
 299         }
 300
 301         if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
 302                 tun->dev->stats.rx_dropped++;
 303                 return -ENOMEM;
 304         }
 305
 306         if (align)
 307                 skb_reserve(skb, align);
 308         if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
 309                 tun->dev->stats.rx_dropped++;
 310                 kfree_skb(skb);
 311                 return -EFAULT;
 312         }
 313
 314         switch (tun->flags & TUN_TYPE_MASK) {
 315         case TUN_TUN_DEV:
 316                 skb_reset_mac_header(skb);
 317                 skb->protocol = pi.proto;
 318                 skb->dev = tun->dev;
 319                 break;
 320         case TUN_TAP_DEV:
 321                 skb->protocol = eth_type_trans(skb, tun->dev);
 322                 break;
 323         };
 324
 325         if (tun->flags & TUN_NOCHECKSUM)
 326                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 327
 328         netif_rx_ni(skb);
 329         tun->dev->last_rx = jiffies;
 330
 331         tun->dev->stats.rx_packets++;
 332         tun->dev->stats.rx_bytes += len;
 333
 334         return count;
 335 }
 336
 337 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
 338                               unsigned long count, loff_t pos)
 339 {
 340         struct tun_struct *tun = iocb->ki_filp->private_data;
 341
 342         if (!tun)
 343                 return -EBADFD;
 344
 345         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
 346
 347         return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
 348 }
 349
 350 /* Put packet to the user space buffer */
 351 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
 352                                        struct sk_buff *skb,
 353                                        struct iovec *iv, int len)
 354 {
 355         struct tun_pi pi = { 0, skb->protocol };
 356         ssize_t total = 0;
 357
 358         if (!(tun->flags & TUN_NO_PI)) {
 359                 if ((len -= sizeof(pi)) < 0)
 360                         return -EINVAL;
 361
 362                 if (len < skb->len) {
 363                         /* Packet will be striped */
 364                         pi.flags |= TUN_PKT_STRIP;
 365                 }
 366
 367                 if (memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
 368                         return -EFAULT;
 369                 total += sizeof(pi);
 370         }
 371
 372         len = min_t(int, skb->len, len);
 373
 374         skb_copy_datagram_iovec(skb, 0, iv, len);
 375         total += len;
 376
 377         tun->dev->stats.tx_packets++;
 378         tun->dev->stats.tx_bytes += len;
 379
 380         return total;
 381 }
 382
 383 static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
 384                             unsigned long count, loff_t pos)
 385 {
 386         struct file *file = iocb->ki_filp;
 387         struct tun_struct *tun = file->private_data;
 388         DECLARE_WAITQUEUE(wait, current);
 389         struct sk_buff *skb;
 390         ssize_t len, ret = 0;
 391         DECLARE_MAC_BUF(mac);
 392
 393         if (!tun)
 394                 return -EBADFD;
 395
 396         DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
 397
 398         len = iov_length(iv, count);
 399         if (len < 0)
 400                 return -EINVAL;
 401
 402         add_wait_queue(&tun->read_wait, &wait);
 403         while (len) {
 404                 const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 405                 u8 addr[ ETH_ALEN];
 406                 int bit_nr;
 407
 408                 current->state = TASK_INTERRUPTIBLE;
 409
 410                 /* Read frames from the queue */
 411                 if (!(skb=skb_dequeue(&tun->readq))) {
 412                         if (file->f_flags & O_NONBLOCK) {
 413                                 ret = -EAGAIN;
 414                                 break;
 415                         }
 416                         if (signal_pending(current)) {
 417                                 ret = -ERESTARTSYS;
 418                                 break;
 419                         }
 420
 421                         /* Nothing to read, let's sleep */
 422                         schedule();
 423                         continue;
 424                 }
 425                 netif_wake_queue(tun->dev);
 426
 427                 /** Decide whether to accept this packet. This code is designed to
 428                  * behave identically to an Ethernet interface. Accept the packet if
 429                  * - we are promiscuous.
 430                  * - the packet is addressed to us.
 431                  * - the packet is broadcast.
 432                  * - the packet is multicast and
 433                  *   - we are multicast promiscous.
 434                  *   - we belong to the multicast group.
 435                  */
 436                 skb_copy_from_linear_data(skb, addr, min_t(size_t, sizeof addr,
 437                                                                    skb->len));
 438                 bit_nr = ether_crc(sizeof addr, addr) >> 26;
 439                 if ((tun->if_flags & IFF_PROMISC) ||
 440                                 memcmp(addr, tun->dev_addr, sizeof addr) == 0 ||
 441                                 memcmp(addr, ones, sizeof addr) == 0 ||
 442                                 (((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) ||
 443                                   (addr[0] == 0x33 && addr[1] == 0x33)) &&
 444                                  ((tun->if_flags & IFF_ALLMULTI) ||
 445                                   (tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) {
 446                         DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %s\n",
 447                                         tun->dev->name, print_mac(mac, addr));
 448                         ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
 449                         kfree_skb(skb);
 450                         break;
 451                 } else {
 452                         DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %s\n",
 453                                         tun->dev->name, print_mac(mac, addr));
 454                         kfree_skb(skb);
 455                         continue;
 456                 }
 457         }
 458
 459         current->state = TASK_RUNNING;
 460         remove_wait_queue(&tun->read_wait, &wait);
 461
 462         return ret;
 463 }
 464
 465 static void tun_setup(struct net_device *dev)
 466 {
 467         struct tun_struct *tun = netdev_priv(dev);
 468
 469         skb_queue_head_init(&tun->readq);
 470         init_waitqueue_head(&tun->read_wait);
 471
 472         tun->owner = -1;
 473         tun->group = -1;
 474
 475         dev->open = tun_net_open;
 476         dev->hard_start_xmit = tun_net_xmit;
 477         dev->stop = tun_net_close;
 478         dev->ethtool_ops = &tun_ethtool_ops;
 479         dev->destructor = free_netdev;
 480         dev->features |= NETIF_F_NETNS_LOCAL;
 481 }
 482
 483 static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name)
 484 {
 485         struct tun_struct *tun;
 486
 487         ASSERT_RTNL();
 488         list_for_each_entry(tun, &tn->dev_list, list) {
 489                 if (!strncmp(tun->dev->name, name, IFNAMSIZ))
 490                     return tun;
 491         }
 492
 493         return NULL;
 494 }
 495
 496 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 497 {
 498         struct tun_net *tn;
 499         struct tun_struct *tun;
 500         struct net_device *dev;
 501         int err;
 502
 503         tn = net_generic(net, tun_net_id);
 504         tun = tun_get_by_name(tn, ifr->ifr_name);
 505         if (tun) {
 506                 if (tun->attached)
 507                         return -EBUSY;
 508
 509                 /* Check permissions */
 510                 if (((tun->owner != -1 &&
 511                       current->euid != tun->owner) ||
 512                      (tun->group != -1 &&
 513                       current->egid != tun->group)) &&
 514                      !capable(CAP_NET_ADMIN))
 515                         return -EPERM;
 516         }
 517         else if (__dev_get_by_name(net, ifr->ifr_name))
 518                 return -EINVAL;
 519         else {
 520                 char *name;
 521                 unsigned long flags = 0;
 522
 523                 err = -EINVAL;
 524
 525                 if (!capable(CAP_NET_ADMIN))
 526                         return -EPERM;
 527
 528                 /* Set dev type */
 529                 if (ifr->ifr_flags & IFF_TUN) {
 530                         /* TUN device */
 531                         flags |= TUN_TUN_DEV;
 532                         name = "tun%d";
 533                 } else if (ifr->ifr_flags & IFF_TAP) {
 534                         /* TAP device */
 535                         flags |= TUN_TAP_DEV;
 536                         name = "tap%d";
 537                 } else
 538                         goto failed;
 539
 540                 if (*ifr->ifr_name)
 541                         name = ifr->ifr_name;
 542
 543                 dev = alloc_netdev(sizeof(struct tun_struct), name,
 544                                    tun_setup);
 545                 if (!dev)
 546                         return -ENOMEM;
 547
 548                 dev_net_set(dev, net);
 549                 tun = netdev_priv(dev);
 550                 tun->dev = dev;
 551                 tun->flags = flags;
 552                 /* Be promiscuous by default to maintain previous behaviour. */
 553                 tun->if_flags = IFF_PROMISC;
 554                 /* Generate random Ethernet address. */
 555                 *(__be16 *)tun->dev_addr = htons(0x00FF);
 556                 get_random_bytes(tun->dev_addr + sizeof(u16), 4);
 557                 memset(tun->chr_filter, 0, sizeof tun->chr_filter);
 558
 559                 tun_net_init(dev);
 560
 561                 if (strchr(dev->name, '%')) {
 562                         err = dev_alloc_name(dev, dev->name);
 563                         if (err < 0)
 564                                 goto err_free_dev;
 565                 }
 566
 567                 err = register_netdevice(tun->dev);
 568                 if (err < 0)
 569                         goto err_free_dev;
 570
 571                 list_add(&tun->list, &tn->dev_list);
 572         }
 573
 574         DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
 575
 576         if (ifr->ifr_flags & IFF_NO_PI)
 577                 tun->flags |= TUN_NO_PI;
 578         else
 579                 tun->flags &= ~TUN_NO_PI;
 580
 581         if (ifr->ifr_flags & IFF_ONE_QUEUE)
 582                 tun->flags |= TUN_ONE_QUEUE;
 583         else
 584                 tun->flags &= ~TUN_ONE_QUEUE;
 585
 586         file->private_data = tun;
 587         tun->attached = 1;
 588         get_net(dev_net(tun->dev));
 589
 590         strcpy(ifr->ifr_name, tun->dev->name);
 591         return 0;
 592
 593  err_free_dev:
 594         free_netdev(dev);
 595  failed:
 596         return err;
 597 }
 598
 599 static int tun_chr_ioctl(struct inode *inode, struct file *file,
 600                          unsigned int cmd, unsigned long arg)
 601 {
 602         struct tun_struct *tun = file->private_data;
 603         void __user* argp = (void __user*)arg;
 604         struct ifreq ifr;
 605         DECLARE_MAC_BUF(mac);
 606
 607         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
 608                 if (copy_from_user(&ifr, argp, sizeof ifr))
 609                         return -EFAULT;
 610
 611         if (cmd == TUNSETIFF && !tun) {
 612                 int err;
 613
 614                 ifr.ifr_name[IFNAMSIZ-1] = '\0';
 615
 616                 rtnl_lock();
 617                 err = tun_set_iff(current->nsproxy->net_ns, file, &ifr);
 618                 rtnl_unlock();
 619
 620                 if (err)
 621                         return err;
 622
 623                 if (copy_to_user(argp, &ifr, sizeof(ifr)))
 624                         return -EFAULT;
 625                 return 0;
 626         }
 627
 628         if (!tun)
 629                 return -EBADFD;
 630
 631         DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
 632
 633         switch (cmd) {
 634         case TUNSETNOCSUM:
 635                 /* Disable/Enable checksum */
 636                 if (arg)
 637                         tun->flags |= TUN_NOCHECKSUM;
 638                 else
 639                         tun->flags &= ~TUN_NOCHECKSUM;
 640
 641                 DBG(KERN_INFO "%s: checksum %s\n",
 642                     tun->dev->name, arg ? "disabled" : "enabled");
 643                 break;
 644
 645         case TUNSETPERSIST:
 646                 /* Disable/Enable persist mode */
 647                 if (arg)
 648                         tun->flags |= TUN_PERSIST;
 649                 else
 650                         tun->flags &= ~TUN_PERSIST;
 651
 652                 DBG(KERN_INFO "%s: persist %s\n",
 653                     tun->dev->name, arg ? "enabled" : "disabled");
 654                 break;
 655
 656         case TUNSETOWNER:
 657                 /* Set owner of the device */
 658                 tun->owner = (uid_t) arg;
 659
 660                 DBG(KERN_INFO "%s: owner set to %d\n", tun->dev->name, tun->owner);
 661                 break;
 662
 663         case TUNSETGROUP:
 664                 /* Set group of the device */
 665                 tun->group= (gid_t) arg;
 666
 667                 DBG(KERN_INFO "%s: group set to %d\n", tun->dev->name, tun->group);
 668                 break;
 669
 670         case TUNSETLINK:
 671         {
 672                 int ret;
 673
 674                 /* Only allow setting the type when the interface is down */
 675                 rtnl_lock();
 676                 if (tun->dev->flags & IFF_UP) {
 677                         DBG(KERN_INFO "%s: Linktype set failed because interface is up\n",
 678                                 tun->dev->name);
 679                         ret = -EBUSY;
 680                 } else {
 681                         tun->dev->type = (int) arg;
 682                         DBG(KERN_INFO "%s: linktype set to %d\n", tun->dev->name, tun->dev->type);
 683                         ret = 0;
 684                 }
 685                 rtnl_unlock();
 686                 return ret;
 687         }
 688
 689 #ifdef TUN_DEBUG
 690         case TUNSETDEBUG:
 691                 tun->debug = arg;
 692                 break;
 693 #endif
 694
 695         case SIOCGIFFLAGS:
 696                 ifr.ifr_flags = tun->if_flags;
 697                 if (copy_to_user( argp, &ifr, sizeof ifr))
 698                         return -EFAULT;
 699                 return 0;
 700
 701         case SIOCSIFFLAGS:
 702                 /** Set the character device's interface flags. Currently only
 703                  * IFF_PROMISC and IFF_ALLMULTI are used. */
 704                 tun->if_flags = ifr.ifr_flags;
 705                 DBG(KERN_INFO "%s: interface flags 0x%lx\n",
 706                                 tun->dev->name, tun->if_flags);
 707                 return 0;
 708
 709         case SIOCGIFHWADDR:
 710                 /* Note: the actual net device's address may be different */
 711                 memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr,
 712                                 min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
 713                 if (copy_to_user( argp, &ifr, sizeof ifr))
 714                         return -EFAULT;
 715                 return 0;
 716
 717         case SIOCSIFHWADDR:
 718         {
 719                 /* try to set the actual net device's hw address */
 720                 int ret;
 721
 722                 rtnl_lock();
 723                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
 724                 rtnl_unlock();
 725
 726                 if (ret == 0) {
 727                         /** Set the character device's hardware address. This is used when
 728                          * filtering packets being sent from the network device to the character
 729                          * device. */
 730                         memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data,
 731                                         min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr));
 732                         DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n",
 733                                         tun->dev->name,
 734                                         tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2],
 735                                         tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]);
 736                 }
 737
 738                 return  ret;
 739         }
 740
 741         case SIOCADDMULTI:
 742                 /** Add the specified group to the character device's multicast filter
 743                  * list. */
 744                 add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
 745                 DBG(KERN_DEBUG "%s: add multi: %s\n",
 746                     tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
 747                 return 0;
 748
 749         case SIOCDELMULTI:
 750                 /** Remove the specified group from the character device's multicast
 751                  * filter list. */
 752                 del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data);
 753                 DBG(KERN_DEBUG "%s: del multi: %s\n",
 754                     tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data));
 755                 return 0;
 756
 757         default:
 758                 return -EINVAL;
 759         };
 760
 761         return 0;
 762 }
 763
 764 static int tun_chr_fasync(int fd, struct file *file, int on)
 765 {
 766         struct tun_struct *tun = file->private_data;
 767         int ret;
 768
 769         if (!tun)
 770                 return -EBADFD;
 771
 772         DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
 773
 774         if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
 775                 return ret;
 776
 777         if (on) {
 778                 ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
 779                 if (ret)
 780                         return ret;
 781                 tun->flags |= TUN_FASYNC;
 782         } else
 783                 tun->flags &= ~TUN_FASYNC;
 784
 785         return 0;
 786 }
 787
 788 static int tun_chr_open(struct inode *inode, struct file * file)
 789 {
 790         DBG1(KERN_INFO "tunX: tun_chr_open\n");
 791         file->private_data = NULL;
 792         return 0;
 793 }
 794
 795 static int tun_chr_close(struct inode *inode, struct file *file)
 796 {
 797         struct tun_struct *tun = file->private_data;
 798
 799         if (!tun)
 800                 return 0;
 801
 802         DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
 803
 804         tun_chr_fasync(-1, file, 0);
 805
 806         rtnl_lock();
 807
 808         /* Detach from net device */
 809         file->private_data = NULL;
 810         tun->attached = 0;
 811         put_net(dev_net(tun->dev));
 812
 813         /* Drop read queue */
 814         skb_queue_purge(&tun->readq);
 815
 816         if (!(tun->flags & TUN_PERSIST)) {
 817                 list_del(&tun->list);
 818                 unregister_netdevice(tun->dev);
 819         }
 820
 821         rtnl_unlock();
 822
 823         return 0;
 824 }
 825
 826 static const struct file_operations tun_fops = {
 827         .owner  = THIS_MODULE,
 828         .llseek = no_llseek,
 829         .read  = do_sync_read,
 830         .aio_read  = tun_chr_aio_read,
 831         .write = do_sync_write,
 832         .aio_write = tun_chr_aio_write,
 833         .poll   = tun_chr_poll,
 834         .ioctl  = tun_chr_ioctl,
 835         .open   = tun_chr_open,
 836         .release = tun_chr_close,
 837         .fasync = tun_chr_fasync
 838 };
 839
 840 static struct miscdevice tun_miscdev = {
 841         .minor = TUN_MINOR,
 842         .name = "tun",
 843         .fops = &tun_fops,
 844 };
 845
 846 /* ethtool interface */
 847
 848 static int tun_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
 849 {
 850         cmd->supported          = 0;
 851         cmd->advertising        = 0;
 852         cmd->speed              = SPEED_10;
 853         cmd->duplex             = DUPLEX_FULL;
 854         cmd->port               = PORT_TP;
 855         cmd->phy_address        = 0;
 856         cmd->transceiver        = XCVR_INTERNAL;
 857         cmd->autoneg            = AUTONEG_DISABLE;
 858         cmd->maxtxpkt           = 0;
 859         cmd->maxrxpkt           = 0;
 860         return 0;
 861 }
 862
 863 static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 864 {
 865         struct tun_struct *tun = netdev_priv(dev);
 866
 867         strcpy(info->driver, DRV_NAME);
 868         strcpy(info->version, DRV_VERSION);
 869         strcpy(info->fw_version, "N/A");
 870
 871         switch (tun->flags & TUN_TYPE_MASK) {
 872         case TUN_TUN_DEV:
 873                 strcpy(info->bus_info, "tun");
 874                 break;
 875         case TUN_TAP_DEV:
 876                 strcpy(info->bus_info, "tap");
 877                 break;
 878         }
 879 }
 880
 881 static u32 tun_get_msglevel(struct net_device *dev)
 882 {
 883 #ifdef TUN_DEBUG
 884         struct tun_struct *tun = netdev_priv(dev);
 885         return tun->debug;
 886 #else
 887         return -EOPNOTSUPP;
 888 #endif
 889 }
 890
 891 static void tun_set_msglevel(struct net_device *dev, u32 value)
 892 {
 893 #ifdef TUN_DEBUG
 894         struct tun_struct *tun = netdev_priv(dev);
 895         tun->debug = value;
 896 #endif
 897 }
 898
 899 static u32 tun_get_link(struct net_device *dev)
 900 {
 901         struct tun_struct *tun = netdev_priv(dev);
 902         return tun->attached;
 903 }
 904
 905 static u32 tun_get_rx_csum(struct net_device *dev)
 906 {
 907         struct tun_struct *tun = netdev_priv(dev);
 908         return (tun->flags & TUN_NOCHECKSUM) == 0;
 909 }
 910
 911 static int tun_set_rx_csum(struct net_device *dev, u32 data)
 912 {
 913         struct tun_struct *tun = netdev_priv(dev);
 914         if (data)
 915                 tun->flags &= ~TUN_NOCHECKSUM;
 916         else
 917                 tun->flags |= TUN_NOCHECKSUM;
 918         return 0;
 919 }
 920
 921 static const struct ethtool_ops tun_ethtool_ops = {
 922         .get_settings   = tun_get_settings,
 923         .get_drvinfo    = tun_get_drvinfo,
 924         .get_msglevel   = tun_get_msglevel,
 925         .set_msglevel   = tun_set_msglevel,
 926         .get_link       = tun_get_link,
 927         .get_rx_csum    = tun_get_rx_csum,
 928         .set_rx_csum    = tun_set_rx_csum
 929 };
 930
 931 static int tun_init_net(struct net *net)
 932 {
 933         struct tun_net *tn;
 934
 935         tn = kmalloc(sizeof(*tn), GFP_KERNEL);
 936         if (tn == NULL)
 937                 return -ENOMEM;
 938
 939         INIT_LIST_HEAD(&tn->dev_list);
 940
 941         if (net_assign_generic(net, tun_net_id, tn)) {
 942                 kfree(tn);
 943                 return -ENOMEM;
 944         }
 945
 946         return 0;
 947 }
 948
 949 static void tun_exit_net(struct net *net)
 950 {
 951         struct tun_net *tn;
 952         struct tun_struct *tun, *nxt;
 953
 954         tn = net_generic(net, tun_net_id);
 955
 956         rtnl_lock();
 957         list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) {
 958                 DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
 959                 unregister_netdevice(tun->dev);
 960         }
 961         rtnl_unlock();
 962
 963         kfree(tn);
 964 }
 965
 966 static struct pernet_operations tun_net_ops = {
 967         .init = tun_init_net,
 968         .exit = tun_exit_net,
 969 };
 970
 971 static int __init tun_init(void)
 972 {
 973         int ret = 0;
 974
 975         printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
 976         printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
 977
 978         ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops);
 979         if (ret) {
 980                 printk(KERN_ERR "tun: Can't register pernet ops\n");
 981                 goto err_pernet;
 982         }
 983
 984         ret = misc_register(&tun_miscdev);
 985         if (ret) {
 986                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
 987                 goto err_misc;
 988         }
 989         return 0;
 990
 991 err_misc:
 992         unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
 993 err_pernet:
 994         return ret;
 995 }
 996
 997 static void tun_cleanup(void)
 998 {
 999         misc_deregister(&tun_miscdev);
1000         unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
1001 }
1002
1003 module_init(tun_init);
1004 module_exit(tun_cleanup);
1005 MODULE_DESCRIPTION(DRV_DESCRIPTION);
1006 MODULE_AUTHOR(DRV_COPYRIGHT);
1007 MODULE_LICENSE("GPL");
1008 MODULE_ALIAS_MISCDEV(TUN_MINOR);