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