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